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37,514 Abstracts & Growing Daily. Sourced from the US National Library of Medicine.


Resveratrol has anti-inflammatory properties in the brain.

Neuroinflammation is an important contributor to pathogenesis of neurological disorders, with microglial activation as a hallmark of neuroinflammation. Microglia serve the role of immune surveillance under normal conditions, but after brain damage or exposure to inflammation, microglia are activated and secrete pro-inflammatory and neurotoxic mediators. Sustained production of these factors contributes to neuronal damage. Therefore, inhibition of microglia-mediated neuroinflammation may become a promising therapeutic target for neurological disorders. Resveratrol, a non-flavonoid polyphenol rich in red wine and grapes, has beneficial health effects from its antioxidant, anticancer and anti-inflammatory properties. Recently, resveratrol has been shown to protect against various neurological disorders in experimental models, including brain ischemia, seizures, and neurodegenerative disease models. This minireview summarized the anti-inflammatory activities of resveratrol in the brain from both in vivo and in vitro studies, and highlighted the inhibition of activated microglia as a potential mechanism of neuroprotection. The release of various pro-inflammatory factors, the production of reactive oxygen species, and the activation of signal pathways leading to neuroinflammation were discussed in relation to microglial activation. Taken together, microglia are an important target for anti-inflammatory activities of resveratrol in the brain.

Pediatr Neurol. 2008 Jan;38(1):20-6. PMID: 20361959


Oats contain avenanthramides which inhibit proliferation of human colon cancer cell lines in vitro.

A high intake of whole grain foods is associated with reduced risk of colon cancer, but the mechanism underlying this protection has yet to be elucidated. Chronic inflammation and associated cyclooxygenase-2 (COX-2) expression in the colon epithelium are causally related to epithelial carcinogenesis, proliferation, and tumor growth. We examined the effect of avenanthramides (Avns), unique polyphenols from oats with anti-inflammatory properties, on COX-2 expression in macrophages, colon cancer cell lines, and on proliferation of human colon cancer cell lines. We found that Avns-enriched extract of oats (AvExO) had no effect on COX-2 expression, but it did inhibit COX enzyme activity and prostaglandin E(2) (PGE(2)) production in lipopolysaccharide-stimulated mouse peritoneal macrophages. Avns (AvExO, Avn-C, and the methylated form of Avn-C (CH3-Avn-C)) significantly inhibited cell proliferation of both COX-2-positive HT29, Caco-2, and LS174T, and COX-2-negative HCT116 human colon cancer cell lines, CH3-Avn-C being the most potent. However, Avns had no effect on COX-2 expression and PGE(2) production in Caco-2 and HT29 colon cancer cells. These results indicate that the inhibitory effect of Avns on colon cancer cell proliferation may be independent of COX-2 expression and PGE(2) production. Thus, Avns might reduce colon cancer risk through inhibition of macrophage PGE(2) production and non-COX-related antiproliferative effects in colon cancer cells. Interestingly, Avns had no effect on cell viability of confluence-induced differentiated Caco-2 cells, which display the characteristics of normal colonic epithelial cells. Our results suggest that the consumption of oats and oat bran may reduce the risk of colon cancer not only because of their high fiber content but also due to Avns, which attenuate proliferation of colonic cancer cells.

Nutr Cancer. 2010;62(8):1007-16. PMID: 21058188


Red wine polyphenols inhibit human breast cancer cells.

Breast cancer (one of the most common malignancy in Western societies), as well as esophagus, stomach, lung, bladder, and prostate cancer, depend on environmental factors and diet for growth and evolution. Dietary micronutriments have been proposed as effective inhibitory agents for cancer initiation, progression, and incidence. Among them, polyphenols, present in different foods and beverages, have retained attention in recent years. Red wine is a rich source of polyphenols, and their antioxidant and tumor arresting effects have been demonstrated in different in vitro and in vivo systems. In the present study, we have measured the antiproliferative effect of red wine concentrate, its total polyphenolic pool, and purified catechin, epicatechin, quercetin, and resveratrol, which account for more than 70% of the total polyphenols in red wine, on the proliferation of hormone sensitive (MCF7, T47D) and resistant (MDA-MB-231) breast cancer cell lines. Our results indicate that polyphenols, at the picomolar or the nanomolar range, decrease cell proliferation in a dose- and a time-dependant manner. In hormone sensitive cell lines, a specific interaction of each polyphenol with steroid receptors was observed, with IC(50)s lower than previously described. Interaction of polyphenols with steroid receptors cannot fully explain their inhibitory effect on cell proliferation. In addition, discrete antioxidant action on each cell line was detected under the same concentrations, both by modifying the toxic effect of H(2)O(2), and the production of reactive oxygen species (ROS), after phorbol ester stimulation. Our results suggest that low concentrations of polyphenols, and consecutively, consumption of wine, or other polyphenol-rich foods and beverages, could have a beneficial antiproliferative effect on breast cancer cell growth.

J Cell Biochem. 2000 Jun 6;78(3):429-41. PMID: 10861841


Resveratrol or a combination of resveratrol and quercetin, in concentrations equivalent to that present in red wines, are effective inhibitors of oral squamous carcinoma cell (SCC-25) growth and proliferation.

Resveratrol and quercetin are polyphenols which have been detected in significant amounts in green vegetables, citrus fruits and red grape wines. Beneficial effects attributed to these compounds include anti-inflammatory, antiviral and antitumor properties. The effect of resveratrol and quercetin on growth of human oral cancer cells is unknown. Resveratrol and quercetin, in concentrations of 1 to 100 microM, were incubated in triplicates with human oral squamous carcinoma cells SCC-25 in DMEM-HAM's F-12 supplemented with fetal calf serum and antibiotics in an atmosphere of 5% CO2 in air at 37 degrees C for 72 h. Cell growth was determined by counting the number of viable cells with a hemocytometer. Cell proliferation was measured by means of incorporation of [3H]thymidine in nuclear DNA. Resveratrol at 10 and 100 microM induced significant dose-dependent inhibition in cell growth as well as in DNA synthesis. Quercetin exhibited a biphasic effect, stimulation at 1 and 10 microM, and minimal inhibition at 100 microM in cell growth and DNA synthesis. Combining 50 microM of resveratrol with 10, 25 and 50 microM of quercetin resulted in a gradual and significant increase in the inhibitory effect of quercetin on cell growth and DNA synthesis. We conclude that resveratrol or a combination of resveratrol and quercetin, in concentrations equivalent to that present in red wines, are effective inhibitors of oral squamous carcinoma cell (SCC-25) growth and proliferation, and warrant further investigation as cancer chemopreventive agents.

Basic Clin Pharmacol Toxicol. 2006 Jan;98(1):32-7. PMID: 10211549


Resveratrol has antioxidant and anti-inflammatory effects in airway disease.

Respiratory diseases, such as asthma and chronic obstructive pulmonary disease (COPD), are a significant and increasing global health problem. These diseases are characterized by airway inflammation, which develops in response to various stimuli. In asthma, inflammation is driven by exposure to a variety of triggers, including allergens and viruses, which activate components of both the innate and acquired immune responses. In COPD, exposure to cigarette smoke is the primary stimulus of airway inflammation. Activation of airway inflammatory cells leads to the release of excessive quantities of reactive oxygen species (ROS), resulting in oxidative stress. Antioxidants provide protection against the damaging effects of oxidative stress and thus may be useful in the management of inflammatory airways disease. Resveratrol, a polyphenol that demonstrates both antioxidative and anti-inflammatory functions, has been shown to improve outcomes in a variety of diseases, in particular, in cancer. We review the evidence for a protective role of resveratrol in respiratory disease. Mechanisms of resveratrol action that may be relevant to respiratory disease are described. We conclude that resveratrol has potential as a therapeutic agent in respiratory disease, which should be further investigated.

Antioxid Redox Signal. 2010 Nov 15;13(10):1535-48. PMID: 20214495


Resveratrol mobilizes endogenous copper in human peripheral lymphocytes leading to oxidative DNA breakage which may have chemoprentive

Plant polyphenols are important components of human diet, and a number of them are considered to possess chemopreventive and therapeutic properties against cancer. They are recognized as naturally occurring anti-oxidants but also act as pro-oxidants catalyzing DNA degradation in the presence of metal ions such as copper. The plant polyphenol resveratrol confers resistance to plants against fungal agents and has been implicated as a cancer chemopreventive agent. Of particular interest is the observation that resveratrol has been found to induce apoptosis in cancer cell lines but not in normal cells. Over the last few years, we have shown that resveratrol is capable of causing DNA breakage in cells such as human lymphocytes. Such cellular DNA breakage is inhibited by copper specific chelators but not by iron and zinc chelating agents. Similar results are obtained by using permeabilized cells or with isolated nuclei, indicating that chromatin-bound copper is mobilized in this reaction. It is well established that tissue, cellular and serum copper levels are considerably elevated in various malignancies. Therefore, cancer cells may be more subject to electron transfer between copper ions and resveratrol to generate reactive oxygen species responsible for DNA cleavage. The results are in support of our hypothesis that anti-cancer mechanism of plant polyphenols involves mobilization of endogenous copper and the consequent pro-oxidant action. Such a mechanism better explains the anti-cancer effects of resveratrol, as it accounts for the preferential cytotoxicity towards cancer cells.

Pharm Res. 2010 Jun;27(6):979-88. Epub 2010 Jan 30. PMID: 20119749


Resveratrol induces programmed cell death and cell cycle arrest of human bladder cancer cells.

Resveratrol, a naturally occurring polyphenolic antioxidant compound present in grapes and red wine, has been reported to hold various biochemical responses. In this preliminary study, we evaluate the chemopreventive potential of resveratrol against bladder cancer and its mechanism of action. Treatment of bladder cancer cells with resveratrol resulted in a significant decrease in cell viability. Resveratrol induced apoptosis through the modulation of Bcl-2 family proteins and activation of caspase 9 and caspase 3 followed by poly(ADP-ribose) polymerase degradation. Treatment with resveratrol led to G(1) phase cell cycle arrest in T24 cells by activation of p21 and downregulation of cyclin D1, cyclin-dependent kinase 4, and phosphorylated Rb. Resveratrol also inhibited the phosphorylation of Akt, whereas the phosphorylation of p38 MAPK was enhanced. In addition, resveratrol treatment decreased the expression of vascular endothelial growth factor and fibroblast growth factor-2, which might contribute to the inhibition of tumor growth on the bladder cancer xenograft model. These findings suggest that reveratrol could be an important chemoprevention agent for bladder cancer.

Cancer Sci. 2010 Feb;101(2):488-93. Epub 2009 Oct 27. PMID: 20028382


Antioxidant extracts from potatoes inhibit the proliferation of human colon and liver cancer cells.

Antioxidant extracts from 5 potato lines were evaluated for antioxidant activity, total phenolics, chlorogenic acid, anthocyanin content, and in vitro anticancer capacity. Analysis showed that Mexican wild species S. pinnatisectum had the highest antioxidant activity, total phenolic, and chlorogenic acid content. The proliferation of colon cancer and liver cancer cells was significantly inhibited by potato antioxidant extracts. The highest antiproliferative activity was observed in extracts of S. pinnatisectum and the lowest in Northstar. An inverse correlation was found between total phenolics and the EC(50) of colon cancer cell (R(2) = 0.9303), as well as liver cancer cell proliferation (R(2) = 0.8992). The relationship between antioxidant activity and EC(50) of colon cancer/liver cancer cell proliferation was significant (R(2) = 0.8144; R(2) = 0.956, respectively). A significant difference in inhibition of cancer cells (P

Nutr Cancer. 2011 Sep 2. Epub 2011 Sep 2. PMID: 21888504


"Curcumin and Liver Cancer: A Review."

Primary liver cancer, also known as hepatocellular carcinoma (HCC), is one of the most lethal cancers having worldwide prevalence. Although most HCC cases are reported in the developing countries of Asia and Africa, there has been an alarming increase in HCC cases in Western Europe as well as United States. Chronic liver diseases, viral hepatitis, alcoholism as well as dietary carcinogens, such as aflatoxins and nitrosoamines, contribute to HCC. Liver transplantation as well as surgical resection at best offer limited treatment options. Thus, there exists a critical need to investigate and evaluate possible alternative chemopreventive and therapeutic strategies which may be effective in the control of liver cancer. HCC, most often, develops and progresses in a milieu of oxidative stress and inflammation. Phytochemicals, such as dietary polyphenols endowed with potent antioxidant as well as anti-inflammatory properties, provide a suitable alternative in affording alleviation of HCC. Curcumin, the principal polyphenolic curcuminoid, obtained from the turmeric rhizome Curcuma longa has long been used to cure several chronic ailments, such as neoplastic and neurodegenerative diseases. Studies suggest that curcumin may have antitumor, antioxidant, and anti-inflammatory properties. This article reviews the effects of curcumin in preclinical in vitro and in vivo models of HCC with particular emphasis to its antioxidant, apoptotic and anti-inflammatory effects as well as involvement in various molecular signaling mechanisms. This review also discusses potential challenges involved in the use of curcumin in HCC, such as bioavailability, pharmacokinetics, drug delivery as well as paucity of clinical studies.

Curr Pharm Biotechnol. 2011 Apr 5. Epub 2011 Apr 5. PMID: 21466422


"Curcumin nanoparticles improve the physicochemical properties of curcumin and effectively enhance its antioxidant and antihepatoma activities."

Curcumin (CUR), a natural polyphenol isolated from tumeric ( Curcuma longa ), has been documented to possess antioxidant and anticancer activities. Unfortunately, the compound has poor aqueous solubility, which results in poor bioavailability following high doses by oral administration. To improve the solubility of CUR, we developed a novel curcumin nanoparticle system (CURN) and investigated its physicochemical properties as well as its enhanced dissolution mechanism. Our results indicated that CURN improved the physicochemical properties of CUR, including a reduction in particle size and the formation of an amorphous state with hydrogen bonding, both of which increased the drug release of the compound. Moreover, in vitro studies indicated that CURN significantly enhanced the antioxidant and antihepatoma activities of CUR (P

J Agric Food Chem. 2010 Jun 23 ;58(12):7376-82. PMID: 20486686


"Resveratrol inhibits tumor necrosis factor-alpha-mediated matrix metalloproteinase-9 expression and invasion of human hepatocellular carcinoma cells."

Resveratrol is an active polyphenol found in red wine that has anti-cancer effects, but the molecular mechanisms of resveratrol on tumor invasion inhibition have not been well documented. The aim of this study was to elucidate the effects of resveratrol on invasion ability of human hepatocellular carcinoma cells and TNF-alpha-mediated MMP-9 expression. The expression activity of MMP-9 was measured by zymography, RT-PCR and western blot analysis. The expression of NF-kappa B was measured by EMSA and western blot analysis. TNF-alpha induced the MMP-9 expression in HepG2 cells. Resveratrol significantly inhibited TNF-alpha-mediated MMP-9 expression in HepG2 cells. NF-kappa B inhibitor induced a marked reduction in MMP-9 expression, and it suggested that NF-kappa B could play an important role in TNF-alpha-mediated MMP-9 expression. Furthermore, resveratrol significantly suppressed TNF-alpha-mediated NF-kappa B expression and invasion of HepG2 cells. Our results showed that resveratrol inhibited TNF-alpha-mediated MMP-9 expression and invasion of human hepatocellular carcinoma cells. The inhibitory effects are partly associated with the downregulation of the NF-kappa B signaling pathway.

Biomed Pharmacother. 2008 Jul-Aug;62(6):366-72. Epub 2007 Oct 22. PMID: 17988825


Solanum nigrum L. polyphenolic extract inhibits hepatocarcinoma cell growth.

BACKGROUND: Hepatocellular carcinoma (HCC) is a rapidly progressive cancer with poor prognosis. However, there have been no significant new developments in treating liver cancer. To search for an effective agent against HCC progression, we prepared a polyphenolic extract of Solanum nigrum L. (SNPE), a herbal plant indigenous to Southeast Asia and commonly used in oriental medicine, to evaluate its inhibitive effect on hepatocarcinoma cell growth. The growth inhibition of HepG2 cells in vitro and in vivo was determined in the presence of SNPE.RESULTS: We found 1 µg mL(-1) SNPE-fed mice showed decreased tumor weight and tumor volume by 90%. Notably, 2 µg mL(-1) SNPE resulted in almost complete inhibition of tumor weight as well as tumor volume. In line with this notion, SNPE reduced the viability of HepG(2) cells in a dose-dependent manner. HepG(2) cells were arrested in the G(2)/M phase of the cell cycle; meanwhile, the protein levels of cell CDC25A, CDC25B, and CDC25C were clearly reduced. Moreover, sub-G(1) phase accumulation and caspases-3, 8, and 9 cleavages were induced by SNPE.CONCLUSION: This study shows that SNPE is a potent agent for HCC treatment through targeting G(2)/M arrest and apoptosis induction, achieving cell growth inhibition.

J Sci Food Agric. 2011 Jan 15 ;91(1):178-85. Epub 2010 Sep 17. PMID: 20853273


Quercetin exhibits an inhibitory effect in a human hepatoma cell line.

Dietary polyphenols have been associated with the reduced risk of chronic diseases such as cancer, but the precise underlying mechanism of protection remains unclear. The aim of this study was to investigate the effect of quercetin on the activation of the apoptotic pathway in a human hepatoma cell line (HepG2). Treatment of cells for 18 h with quercetin induced cell death in a dose-dependent manner; however, a shorter treatment (4 h) had no effect on cell viability. Incubation of HepG2 cells with quercetin for 18 h induced apoptosis by the activation of caspase-3 and -9, but not caspase-8. Moreover, this flavonoid decreased the Bcl-xL:Bcl-xS ratio and increased translocation of Bax to the mitochondrial membrane. A sustained inhibition of the major survival signals, Akt and extracellular regulated kinase (ERK), also occurred in quercetin-treated cells. These data suggest that quercetin may induce apoptosis by direct activation of caspase cascade (mitochondrial pathway) and by inhibiting survival signaling in HepG2.

J Nutr. 2006 Nov ;136(11):2715-21. PMID: 17056790


"Curcumin: A Potential Neuroprotective Agent in Parkinson's Disease."

Parkinson's disease (PD) is an age-associated neurodegenerative disease clinically characterized as a movement disorder. The motor symptoms in PD arise due to selective degeneration of dopaminergic neurons in the substantia nigra of the ventral midbrain thereby depleting the dopamine levels in the striatum. Most of the current pharmacotherapeutic approaches in PD are aimed at replenishing the striatal dopamine. Although these drugs provide symptomatic relief during early PD, many patients develop motor complications with long-term treatment. Further, PD medications do not effectively tackle tremor, postural instability and cognitive deficits. Most importantly, most of these drugs do not exhibit neuroprotective effects in patients. Consequently, novel therapies involving natural antioxidants and plant products/molecules with neuroprotective properties are being exploited for adjunctive therapy. Curcumin is a polyphenol and an active component of turmeric (Curcuma longa), a dietary spice used in Indian cuisine and medicine. Curcumin exhibits antioxidant, anti-inflammatory and anti-cancer properties, crosses the blood-brain barrier and is neuroprotective in neurological disorders. Several studies in different experimental models of PD strongly support the clinical application of curcumin in PD. The current review explores the therapeutic potential of curcumin in PD.

Curr Pharm Des. 2012 Jan 1. Epub 2012 Jan 1. PMID: 22211691


The soy isoflavone genistein appears to repress human breast cancer cells.

Mammary stem cells are undifferentiated epithelial cells which initiate mammary tumors and render them resistant to anticancer therapies, when deregulated. Diets rich in fruits and vegetables are implicated in breast cancer risk reduction, yet underlying mechanisms are poorly understood. Here, we addressed whether dietary factors selectively target mammary epithelial cells that display stem-like/progenitor subpopulations with previously recognized tumor-initiating potential. Using estrogen receptor-positive MCF-7 and estrogen receptor-negative MDA-MB-231 human breast cancer cell lines and freshly isolated epithelial cells from MMTV-Wnt-1 transgenic mouse mammary tumors, we demonstrate that sera of adult mice consuming soy isoflavone genistein (GEN) or blueberry (BB) polyphenol-containing diets alter the population of stem-like/progenitor cells, as measured by their functional ability to self-renew and form anchorage-independent spheroid cultures in vitro at low frequency (1-2%). Serum effects on mammosphere formation were dose-dependently replicated by GEN (40 nM>2 μM) and targeted the basal stem-like CD44(+)/CD24(-)/ESA(+) and the luminal progenitor CD24(+) subpopulations in MDA-MB231 and MCF-7 cells. GEN inhibition of mammosphere formation was mimicked by the Akt inhibitor perifosine and was associated with enhanced tumor suppressor PTEN expression. By contrast, a select mixture of BB phenolic acids was only active in MDA-MD-231 cells and its CD44(+)/CD24(-)/ESA(+) subpopulation, and this activity was independent of induction of PTEN expression. These findings delineate a novel and selective function of distinct dietary factors in targeting stem/progenitor cell populations in estrogen receptor-dependent and -independent breast cancers.

Carcinogenesis. 2012 Jan 4. Epub 2012 Jan 4. PMID: 22219179


Curcumin has a synergistic antitumor effect in combination with docetaxel against lung cancer.

Curcumin (Cum), the principal polyphenolic curcuminoid, obtained from the turmeric rhizome Curcuma longa, is recently reported to have potential antitumor effects in vitro and in vivo. Docetaxel (Doc) is considered as first-line chemotherapy for the treatment of non-small cell lung cancer. Here we report for the first time that Cum could synergistically enhance the in vitro and in vivo antitumor efficacy of Doc against lung cancer. In the current study, combination index (CI) is calculated in both in vitro and in vivo studies to determine the interaction between Cum and Doc. In the in vitro cytotoxicity test, media-effect analysis clearly indicated a synergistic interaction between Cum and Doc in certain concentrations. Moreover, in vivo evaluation further demonstrated the superior anticancer efficacy of Cum + Doc compared with Doc alone by intravenous delivery in an established A549 transplanted xenograft model. Results showed that Cum synergistically increased the efficacy of Doc immediately after 4 days of the initial treatment. Additionally, simultaneous administration of Cum and Doc showed little toxicity to normal tissues including bone marrow and liver at the therapeutic doses. Therefore, in vitro and in vivo evaluations demonstrated the satisfying synergistic antitumor efficacy of Cum and Doc against lung cancer and the introduction of Cum in traditional chemotherapy is a most promising way to counter the spread of non-small cell lung cancer.

Acta Biochim Biophys Sin (Shanghai). 2012 Feb ;44(2):147-53. Epub 2011 Nov 29. PMID: 22126905


Curcumin may have positive epigenetic effects in high prostate cancer.

Curcumin (CUR), a major bioactive polyphenolic component from turmeric curry, Curcuma longa, has been shown to be a potent anti-cancer phytochemical with well-established anti-inflammatory and anti-oxidative stress effects. Chromatin remodeling-related epigenetic regulation has emerged as an important mechanism of carcinogenesis, chemoprevention, and chemotherapy. CUR has been found to inhibit histone acetyltransferase activity, and it was also postulated to be a potential DNA methyltransferase (DNMT) and histone deacetylase (HDAC) inhibitor. In this study, we show that when human prostate LNCaP cells were treated with CUR, it led to demethylation of the first 14 CpG sites of the CpG island of the Neurog1 gene and restored the expression of this cancer-related CpG-methylation epigenome marker gene. At the protein level, CUR treatment had limited effects on the expression of epigenetic modifying proteins MBD2, MeCP2, DNMT1, and DNMT3a. Using ChIP assay, CUR decreased MeCP2 binding to the promoter of Neurog1 dramatically. CUR treatment showed different effects on the protein expression of HDACs, increasing the expression of HDAC1, 4, 5, and 8 but decreasing HDAC3. However, the total HDAC activity was decreased upon CUR treatment. Further analysis of the tri-methylation of histone 3 at lysine 27 (H3K27me3) showed that CUR decreased the enrichment of H3K27me3 at the Neurog1 promoter region as well as at the global level. Taken together, our present study provides evidence on the CpG demethylation ability of CUR on Neurog1 while activating its expression, suggesting a potential epigenetic modifying role for this phytochemical compound in human prostate cancer cells.

AAPS J. 2011 Dec ;13(4):606-14. Epub 2011 Sep 22. PMID: 21938566


Curcumin inhibits multi-drug resistant leukemia cells.

The anti-cancer activities of curcumin (CUR), a polyphenol derived from the plant Curcuma longa, has been extensively studied. In the present study, we found that CUR displayed anti-multidrug-resistant (MDR) activity in K562/A02 cells. A short-time treatment with CUR sufficiently and equally induced DNA damage, decreased cell viability, and triggered apoptosis in parent K562 and MDR K562/A02 cells. The short-time treatment with CUR also caused decrease of pro-caspase 3 in both cell lines and decrease of pro-caspase 9, increase of PARP cleavage and the ratio of Bax/Bcl-xL in MDR K562/A02 cells. Further experiment revealed that CUR was capable of down-regulating P-glycoprotein in MDR K562/A02 cells. Moreover, we observed that Cu(2+) enhanced CUR-mediated apoptosis which was blocked by antioxidants N-acetyl-cysteine and catalase. In summary, the short-time treatment with CUR sufficiently induced DNA damage, decreased cell viability and triggered apoptosis in MDR K562/A02 cells and Cu(2+) enhanced CUR-mediated apoptosis which due to reactive oxygen species generation.

Mol Cell Biochem. 2012 Jan ;360(1-2):253-60. Epub 2011 Sep 22. PMID: 21938404


"Resveratrol enhances prostate cancer cell response to ionizing radiation."

BACKGROUND: Prostate cancer (PrCa) displays resistance to radiotherapy (RT) and requires radiotherapy dose escalation which is associated with greater toxicity. This highlights a need to develop radiation sensitizers to improve the efficacy of RT in PrCa. Ionizing radiation (IR) stimulates pathways of IR-resistance and survival mediated by the protein kinase Akt but it also activates the metabolic energy sensor and tumor suppressor AMP-Activated Protein Kinase (AMPK). Here, we examined the effects of the polyphenol resveratrol (RSV) on the IR-induced inhibition of cell survival, modulation of cell cycle and molecular responses in PrCa cells.METHODS: Androgen-insensitive (PC3), sensitive (22RV1) PrCa and PNT1A normal prostate epithelial cells were treated with RSV alone (2.5-10μM) or in combination with IR (2-8 Gy). Clonogenic assays, cell cycle analysis, microscopy and immunoblotting were performed to assess survival, cell cycle progression and molecular responses.RESULTS: RSV (2.5-5μM) inhibited clonogenic survival of PC3 and 22RV1 cells but not of normal prostate PNT1A cells. RSV specifically sensitized PrCa cells to IR, induced cell cycle arrest at G1-S phase and enhanced IR-induced nuclear aberrations and apoptosis. RSV enhanced IR-induced expression of DNA damage (γH2Ax)and apoptosis (cleaved-caspase 3) markers as well as of the cell cycle regulators p53, p21(cip1) and p27(kip1). RSV enhanced IR-activation of ATM and AMPK but inhibited basal and IR-induced phosphorylation of Akt.CONCLUSIONS: Our results suggest that RSV arrests cell cycle, promotes apoptosis and sensitizes PrCa cells to IR likely through a desirable dual action to activate the ATM-AMPK-p53-p21(cip1)/p27(kip1) and inhibit the Akt signalling pathways.

Radiat Oncol. 2011 ;6:144. Epub 2011 Oct 26. PMID: 22029423


Resveratrol's anti-cancer properties may be associated with its ability to up-regulate miR-663 expression.

MicroRNAs are short noncoding RNAs that regulate the expression of many target genes posttranscriptionally and are thus implicated in a wide array of cellular and developmental processes. The expression of miR-155 or miR-21 is upregulated during the course of the inflammatory response, but these microRNAs are also considered oncogenes due to their upregulation of expression in several types of tumors. Furthermore, it is now well established that inflammation is associated with the induction or the aggravation of nearly 25% of cancers. Therefore, the above microRNAs are thought to link inflammation and cancer. Recently, resveratrol (trans-3,4',5-trihydroxystilbene), a natural polyphenol with antioxidant, anti-inflammatory, and anticancer properties, currently at the stage of preclinical studies for human cancer prevention, has been shown to induce the expression of miR-663, a tumor-suppressor and anti-inflammatory microRNA, while downregulating miR-155 and miR-21. In this paper we will discuss how the use of resveratrol in therapeutics may benefit from the preanalyses on the status of expression of miR-155 or miR-21 as well as of TGFβ1. In addition, we will discuss how resveratrol activity might possibly be enhanced by simultaneously manipulating the levels of its key target microRNAs, such as miR-663.

J Nucleic Acids. 2011 ;2011:102431. Epub 2011 Aug 10. PMID: 21845215


Silibinin prevents the EGFR signaling pathway and may be used as an effective drug for the inhibition of metastasis of human breast cancer.

CD44, the transmembrane receptor for hyaluronan, is implicated in tumor cell invasion and metastasis. The expression of CD44 and its variants is associated with poor prognosis in breast cancer. Here, we investigated the effect of silibinin (a polyphenolic flavonolignan of the herbal plant of Silybum marianum, milk thistle) on the epidermal growth factor (EGF) ligand-induced CD44 expression in human breast cancer cells. The levels of CD44 mRNA and protein expression were greatly increased by EGF and by TGF-α in SKBR3 and BT474 breast cancer cells. In contrast, EGFR ligand-induced CD44 expression was reduced by EGFR inhibitors, AG1478 and lapatinib, respectively. Interestingly, we observed that EGFR ligand-induced CD44 and matrix metalloproteinase-9 (MMP-9) expression was reduced by silibinin treatment in a dose-dependent manner. In addition, silibinin suppressed the EGF-induced phosphorylation of EGFR and extracellular signal-regulated kinase1/2 (ERK1/2), a downstream signaling molecule of EGFR. Therefore, we suggest that silibinin prevents the EGFR signaling pathway and may be used as an effective drug for the inhibition of metastasis of human breast cancer.

Anticancer Res. 2011 Nov ;31(11):3767-73. PMID: 22110198


Herbs provide protection against harmful UV radiation due to their antioxidant activity.

Herbs have been used in medicines and cosmetics from centuries. Their potential to treat different skin diseases, to adorn and improve the skin appearance is well-known. As ultraviolet (UV) radiation can cause sunburns, wrinkles, lower immunity against infections, premature aging, and cancer, there is permanent need for protection from UV radiation and prevention from their side effects. Herbs and herbal preparations have a high potential due to their antioxidant activity, primarily. Antioxidants such as vitamins (vitamin C, vitamin E), flavonoids, and phenolic acids play the main role in fighting against free radical species that are the main cause of numerous negative skin changes. Although isolated plant compounds have a high potential in protection of the skin, whole herbs extracts showed better potential due to their complex composition. Many studies showed that green and black tea (polyphenols) ameliorate adverse skin reactions following UV exposure. The gel from aloe is believed to stimulate skin and assist in new cell growth. Spectrophotometer testing indicates that as a concentrated extract of Krameria triandra it absorbs 25 to 30% of the amount of UV radiation typically absorbed by octyl methoxycinnamate. Sesame oil resists 30% of UV rays, while coconut, peanut, olive, and cottonseed oils block out about 20%. A"sclerojuglonic"compound which is forming from naphthoquinone and keratin is the reaction product that provides UV protection. Traditional use of plant in medication or beautification is the basis for researches and making new trends in cosmetics. This review covers all essential aspects of potential of herbs as radioprotective agents and its future prospects.

Pharmacogn Rev. 2011 Jul ;5(10):164-73. PMID: 22279374


Many of these herbs contain potent antioxidant compounds that provide significant protection against chronic diseases.

Herbs have been used as food and for medicinal purposes for centuries. Research interest has focused on various herbs that possess hypolipidemic, antiplatelet, antitumor, or immune-stimulating properties that may be useful adjuncts in helping reduce the risk of cardiovascular disease and cancer. In different herbs, a wide variety of active phytochemicals, including the flavonoids, terpenoids, lignans, sulfides, polyphenolics, carotenoids, coumarins, saponins, plant sterols, curcumins, and phthalides have been identified. Several of these phytochemicals either inhibit nitrosation or the formation of DNA adducts or stimulate the activity of protective enzymes such as the Phase II enzyme glutathione transferase (EC Research has centered around the biochemical activity of the Allium sp. and the Labiatae, Umbelliferae, and Zingiberaceae families, as well as flaxseed, licorice root, and green tea. Many of these herbs contain potent antioxidant compounds that provide significant protection against chronic diseases. These compounds may protect LDL cholesterol from oxidation, inhibit cyclooxygenase and lipoxygenase enzymes, inhibit lipid peroxidation, or have antiviral or antitumor activity. The volatile essential oils of commonly used culinary herbs, spices, and herbal teas inhibit mevalonate synthesis and thereby suppress cholesterol synthesis and tumor growth.

Am J Clin Nutr. 1999 Sep ;70(3 Suppl):491S-499S. PMID: 10479221


"Sulforaphane synergizes with quercetin to inhibit self-renewal capacity of pancreatic cancer stem cells."

According to the cancer stem cell hypothesis, the aggressive growth and early metastasis of cancer may arise through dysregulation of self-renewal of stem cells. The objectives of this study were to examine the molecular mechanisms by which sulforaphane (SFN, an active compound in cruciferous vegetables) inhibits self-renewal capacity of pancreatic cancer stem cells (CSCs), and synergizes with quercetin, a major polyphenol and flavonoid commonly detected in many fruits and vegetables. Our data demonstrated that SFN inhibited self-renewal capacity of pancreatic CSCs. Inhibition of Nanog by lentiviral-mediated shRNA expression enhanced the inhibitory effects of sulforaphane on self-renewal capacity of CSCs. SFN induced apoptosis by inhibiting the expression of Bcl-2 and XIAP, phosphorylation of FKHR, and activating caspase-3. Moreover, SFN inhibited expression of proteins involved in the epithelial-mesenchymal transition (beta-catenin, vimentin, twist-1, and ZEB1), suggesting the blockade of signaling involved in early metastasis. Furthermore, the combination of quercetin with SFN had synergistic effects on self-renewal capacity of pancreatic CSCs. These data suggest that SFN either alone or in combination with quercetin can eliminate cancer stem cell-characteristics.

Front Biosci (Elite Ed). 2011 ;3:515-28. Epub 2011 Jan 1. PMID: 21196331


"The dietary bioflavonoid quercetin synergizes with epigallocathechin gallate (EGCG) to inhibit prostate cancer stem cell characteristics, invasion, migration and epithelial-mesenchymal transition."

BACKGROUND: Much attention has been recently focused on the role of cancer stem cells (CSCs) in the initiation and progression of solid malignancies. Since CSCs are able to proliferate and self-renew extensively due to their ability to express anti-apoptotic and drug resistant proteins, thus sustaining tumor growth. Therefore, the strategy to eradicate CSCs might have significant clinical implications. The objectives of this study were to examine the molecular mechanisms by which epigallocathechin gallate (EGCG) inhibits stem cell characteristics of prostate CSCs, and synergizes with quercetin, a major polyphenol and flavonoid commonly detected in many fruits and vegetables.RESULTS: Our data indicate that human prostate cancer cell lines contain a small population of CD44+CD133+ cancer stem cells and their self-renewal capacity is inhibited by EGCG. Furthermore, EGCG inhibits the self-renewal capacity of CD44+alpha2beta1+CD133+ CSCs isolated from human primary prostate tumors, as measured by spheroid formation in suspension. EGCG induces apoptosis by activating capase-3/7 and inhibiting the expression of Bcl-2, survivin and XIAP in CSCs. Furthermore, EGCG inhibits epithelial-mesenchymal transition by inhibiting the expression of vimentin, slug, snail and nuclear beta-catenin, and the activity of LEF-1/TCF responsive reporter, and also retards CSC's migration and invasion, suggesting the blockade of signaling involved in early metastasis. Interestingly, quercetin synergizes with EGCG in inhibiting the self-renewal properties of prostate CSCs, inducing apoptosis, and blocking CSC's migration and invasion. These data suggest that EGCG either alone or in combination with quercetin can eliminate cancer stem cell-characteristics.CONCLUSION: Since carcinogenesis is a complex process, combination of bioactive dietary agents with complementary activities will be beneficial for prostate cancer prevention and/ortreatment.

J Mol Signal. 2010 ;5:14. Epub 2010 Aug 18. PMID: 20718984


The dietary polyphenol quercetin targets pancreatic cancer stem cells.

According to the cancer stem cell hypothesis the aggressive growth and early metastasis of pancreatic cancer may arise through dysregulation of self-renewal of stem cells in the tissue. Since recent data suggest targeting of cancer stem cells by some dietary agents we studied the effect of quercetin, a major polyphenol and flavonoid commonly detected in many fruits and vegetables. Using in vitro and in vivo models of pancreatic cancer stem cells we found quercetin-mediated reduction of self-renewal as measured by spheroid and colony formation. Quercetin diminished ALDH1 activity and reverted apoptosis resistance as detected by substrate assays, FACS and Western blot analysis. Importantly, combination of quercetin with sulforaphane, an isothiocyanate enriched in broccoli, had synergistic effects. Although quercetin led to enhanced binding of the survival factor NF-kappaB, co-incubation with sulforaphane completely eliminated this pro-proliferative feature. Moreover, quercetin prevented expression of proteins involved in the epithelial-mesenchymal transition, which was even stronger in presence of sulforaphane, suggesting the blockade of signaling involved in early metastasis. In vivo, quercetin inhibited growth of cancer stem cell-enriched xenografts associated with reduced proliferation, angiogenesis, cancer stem cell-marker expression and induction of apoptosis. Co-incubation with sulforaphane increased these effects and no pronounced toxicity on normal cells or mice was observed. Our data suggest that food ingredients complement each other in the elimination of cancer stem cell-characteristics. Since carcinogenesis is a complex process, combination of bioactive dietary agents with complementary activities may be most effective.

Int J Oncol. 2010 Sep ;37(3):551-61. PMID: 20664924


Preventive compounds curcumin and piperine are capable of targeting breast stem cells.

The cancer stem cell hypothesis asserts that malignancies arise in tissue stem and/or progenitor cells through the dysregulation or acquisition of self-renewal. In order to determine whether the dietary polyphenols, curcumin, and piperine are able to modulate the self-renewal of normal and malignant breast stem cells, we examined the effects of these compounds on mammosphere formation, expression of the breast stem cell marker aldehyde dehydrogenase (ALDH), and Wnt signaling. Mammosphere formation assays were performed after curcumin, piperine, and control treatment in unsorted normal breast epithelial cells and normal stem and early progenitor cells, selected by ALDH positivity. Wnt signaling was examined using a Topflash assay. Both curcumin and piperine inhibited mammosphere formation, serial passaging, and percent of ALDH+ cells by 50% at 5 microM and completely at 10 microM concentration in normal and malignant breast cells. There was no effect on cellular differentiation. Wnt signaling was inhibited by both curcumin and piperine by 50% at 5 microM and completely at 10 microM. Curcumin and piperine separately, and in combination, inhibit breast stem cell self-renewal but do not cause toxicity to differentiated cells. These compounds could be potential cancer preventive agents. Mammosphere formation assays may be a quantifiable biomarker to assess cancer preventive agent efficacy and Wnt signaling assessment can be a mechanistic biomarker for use in human clinical trials.

Breast Cancer Res Treat. 2010 Aug ;122(3):777-85. Epub 2009 Nov 7. PMID: 19898931


Multitargeted therapy of cancer by ellagitannins.

Ellagitannins are bioactive polyphenols that have antioxidant and anti-inflammatory bioactivities. Pomegranate juice has the highest concentration of ellagitannins of any commonly consumed juice and contains the unique ellagitannin, punicalagin. Punicalagin is the largest molecular weight polyphenol known. Ellagitannins are not absorbed intact into the blood stream but are hydrolyzed to ellagic acid. They are also metabolized by gut flora into urolithins which are conjugated in the liver and excreted in the urine. These urolithins are also bioactive and inhibit prostate cancer cell growth. Inhibition of Nuclear Factor Kappa-B activation has been shown in prostate cancer cells and in human prostate cancer xenografts in mice. In clinical studies, pomegranate juice administration led to a decrease in the rate of rise of Prostate Specific Antigen after primary treatment with surgery or radiation. Continued translational research on the chemopreventive potential of pomegranate ellagitannins is ongoing.

Cancer Lett. 2008 Oct 8 ;269(2):262-8. Epub 2008 May 12. PMID: 18468784


Article provides evidence that both resveratrol and curcumin possess great potential both as chemopreventive agents and anticancer drugs.

Despite considerable improvements in the tolerance and efficacy of novel chemotherapeutic agents, the mortality of hematological malignancies is still high due to therapy relapse, which is associated with bad prognosis. Dietary polyphenolic compounds are of growing interest as an alternative approach, especially in cancer treatment, as they have been proven to be safe and display strong antioxidant properties. Here, we provide evidence that both resveratrol and curcumin possess huge potential for application as both chemopreventive agents and anticancer drugs and might represent promising candidates for future treatment of leukemia. Both polyphenols are currently being tested in clinical trials. We describe the underlying mechanisms, but also focus on possible limitations and how they might be overcome in future clinical use--either by chemically synthesized derivatives or special formulations that improve bioavailability and pharmacokinetics.

Molecules. 2010 ;15(10):7035-74. Epub 2010 Oct 12. PMID: 20944521


Apple exhibits anti-aging properties.

In recent years, epidemiological and biochemical studies have shown that eating apples is associated with reduction of occurrence of cancer, degenerative, and cardiovascular diseases. This association is often attributed to the presence of antioxidants such as ascorbic acid (vitamin C) and polyphenols. The substances that hinder the presence of free radicals are also able to protect cells from aging. In our laboratory we used yeast, a unicellular eukaryotic organism, to determine in vivo efficacy of entire apples and their components, such as flesh, skin and polyphenolic fraction, to influence aging and oxidative stress. Our results indicate that all the apple components increase lifespan, with the best result given by the whole fruit, indicating a cooperative role of all apple components.

Oxid Med Cell Longev. 2012 ;2012:491759. Epub 2012 Aug 30. PMID: 22970337


Curcumin reduces cisplatin-induced neurotoxicity.

The potential neuroprotective benefits of curcumin against cisplatin neurotoxicity were investigated. Curcumin is a polyphenol derived from the rhizome of Curcuma longa whose pharmacological effects include antioxidant, anti-inflammatory and anti-cancer properties. Cisplatin is a potent chemotherapeutic drug with activity against a wide variety of tumors, although it has notorious side effects. Cisplatin neurotoxicity is clinically evident in patients that have undergone a full course of chemotherapy and develop a peripheral neuropathy that may affect the treatment regimen and the patient's qualify of life. In this study, we examined whether curcumin can protect against cisplatin neurite outgrowth inhibition in PC12 cells, which is an indicator of the protective potential against neuropathy. We also investigated whether curcumin affects cisplatin effectiveness by analyzing the modulation of p53 gene expression and its effect on cisplatin cytotoxicity in HepG2 tumor cells. Non-cytotoxic concentrations of curcumin reduced in vitro neurotoxicity of cisplatin in PC12 cells. The treatment of PC12 cells with cisplatin (10μg/mL) significantly reduced neurite outgrowth. The tested concentration of curcumin (1.0 and 10μg/mL) did not result in neurite toxicity but nevertheless diminished cisplatin-induced inhibition of neurite outgrowth by up to 50% (p

Neurotoxicology. 2012 Oct 2. Epub 2012 Oct 2. PMID: 23036615


Curcumin inhibits telomerase and induces telomere shortening and apoptosis in brain tumour cells.

Curcumin, a polyphenolic compound isolated from Curcuma longa (Turmeric) is widely used in traditional Ayurvedic medicine. Its potential therapeutic effects on a variety of diseases have long been known. Though anti-tumour effects of curcumin have been reported earlier, its mode of action and telomerase inhibitory effects are not clearly determined in brain tumour cells. In the present study, we demonstrate that curcumin binds to cell surface membrane and infiltrates into cytoplasm to initiate apoptotic events. Curcumin treatment has resulted in higher cytotoxicity in the cells that express telomerase enzyme, highlighting its potential as an anticancer agent. Curcumin induced growth inhibition and cell cycle arrest at G2/M phase in the glioblastoma and medulloblastoma cells used in the study. Gene and protein expression analyses revealed that curcumin down-regulated CCNE1, E2F1 and CDK2 and up-regulated the expression of PTEN genes resulting in growth arrest at G2/M phase. Curcumin-induced apoptosis is found to be associated with increased caspase- 3/7 activity and overexpression of Bax. In addition, down-regulation of Bcl2 and survivin was observed in curcumin treated cells. Besides these effects, we found curcumin to be inhibiting telomerase activity and down-regulating hTERT mRNA expression leading to telomere shortening. We conclude that telomerase inhibitory effects of curcumin underscore its use in adjuvant cancer therapy. J. Cell. Biochem.© 2012 Wiley Periodicals, Inc.

J Cell Biochem. 2012 Nov 28. Epub 2012 Nov 28. PMID: 23192708


Oleuropein Induces Anti-metastatic Effects in Breast Cancer.

Breast cancer causes death due to distant metastases in which tumor cells produce matrix metalloproteinase (MMP) enzymes which facilitate invasion. Oleuropein, the main olive oil polyphenol, has anti-proliferative effects. This study aimed to investigate the effect of oleuropein on the metastatic and anti-metastatic gene expression in the MDA human breast cancer cell line. We evaluated the MMPs and TIMPs gene expression by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) in treated and untreated cells. This study demonstrated that OL may induce anti-metastatic effects on human breast cancer cells. We found that TIMP1,-3, and -4 were over-expressed after all periods of incubation in treated cancer cells compared to untreated cells, while MMP2 and MMP9 genes were down-regulated, at least initially. Treatment of breast cancer cells with oleuropein could help in prevention of cancer metastasis by increasing the TIMPs and suppressing the MMPs gene expressions.

Asian Pac J Cancer Prev. 2012 ;13(9):4555-9. PMID: 23167379


Anticancer activity of green tea polyphenols in prostate gland.

Numerous evidences from prevention studies in humans, support the existence of an association between green tea polyphenols consumption and a reduced cancer risk. Prostate cancer is one of the most frequently diagnosed male neoplasia in the Western countries, which is in agreement with this gland being particularly vulnerable to oxidative stress processes, often associated with tumorigenesis. Tea polyphenols have been extensively studied in cell culture and animal models where they inhibited tumor onset and progression. Prostate cancer appears a suitable target for primary prevention care, since it grows slowly, before symptoms arise, thus offering a relatively long time period for therapeutic interventions. It is, in fact, usually diagnosed in men 50-year-old or older, when even a modest delay in progression of the disease could significantly improve the patients quality of life. Although epidemiological studies have not yet yielded conclusive results on the chemopreventive and anticancer effect of tea polyphenols, there is an increasing trend to employ these substances as conservative management for patients diagnosed with less advanced prostate cancer. Here, we intend to review the most recent observations relating tea polyphenols to human prostate cancer risk, in an attempt to outline better their potential employment for preventing prostate cancer.

Oxid Med Cell Longev. 2012 ;2012:984219. Epub 2012 May 15. PMID: 22666523


"Naturally occurring hydroxytyrosol: synthesis and anticancer potential."

Several epidemiological and animal studies have suggested that polyphenols, a group of secondary plant metabolites occurring mainly in the plant kingdom, may have a protective effect against some chronic degenerative diseases such as cancer. Polyphenols are part of the human diet, being present in vegetal food and beverages. Among them, an olive biophenol named hydroxytyrosol [2-(3,4-dihydroxyphenyl)ethanol, HTyr] has recently received particular attention because of its antioxidant, antiproliferative, pro-apoptotic, and anti-inflammatory activities, which have the potential to specific counteract all cancer hallmarks, thus representing the expectant biological activities underlying the anti-tumor properties of this polyphenol. After a description of the synthetic procedures to prepare pure HTyr, this review takes into consideration the chemopreventive and chemotherapeutic potential of HTyr as the result of its antioxidant, antiproliferative and anti-inflammatory activities. In particular, the review is focused on the current knowledge of the main cellular and molecular mechanisms used by HTyr to affect carcinogenesis, highlighting the specific oncogenic and inflammatory signaling pathways potentially targeted by HTyr.

Curr Med Chem. 2012 Nov 19. Epub 2012 Nov 19. PMID: 23244583


Epigallocatechin Gallate (EGCG) exhibits inhibitory activity against colorectal cancer cells.

Green tea is a popular drink consumed daily by millions of people around the world. Previous studies have shown that some polyphenol compounds from green tea possess anticancer activities. However, systemic evaluation was limited. In this study, we determined the cancer chemopreventive potentials of 10 representative polyphenols (caffeic acid, CA; gallic acid, GA; catechin, C; epicatechin, EC; gallocatechin, GC; catechin gallate, CG; gallocatechin gallate, GCG; epicatechin gallate, ECG; epigallocatechin, EGC; and epigallocatechin gallate, EGCG), and explored their structure-activity relationship. The effect of the 10 polyphenol compounds on the proliferation of HCT-116 and SW-480 human colorectal cancer cells was evaluated using an MTS assay. Cell cycle distribution and apoptotic effects were analyzed by flow cytometry after staining with propidium iodide (PI)/RNase or annexin V/PI. Among the 10 polyphenols, EGCG showed the most potent antiproliferative effects, and significantly induced cell cycle arrest in the G1 phase and cell apoptosis. When the relationship between chemical structure and anticancer activity was examined, C and EC did not show antiproliferative effects, and GA showed some antiproliferative effects. When C and EC esterified with GA to produce CG and ECG, the antiproliferative effects were increased significantly. A similar relationship was found between EGC and EGCG. The gallic acid group significantly enhanced catechin's anticancer potential. This property could be utilized in future semi-synthesis of flavonoid derivatives to develop novel anticancer agents.

Nutrients. 2012 ;4(11):1679-91. Epub 2012 Nov 8. PMID: 23201840


"Green tea polyphenols increase p53 transcriptional activity and acetylation by suppressing class I histone deacetylases."

Acetylation of the tumor suppressor gene p53 at the carboxy-terminal lysine (Lys) residues enhances its transcriptional activity associated with cell cycle arrest and apoptosis. Histone deacetylases (HDACs), a family of evolutionarily conserved enzymes, counterbalance the acetylation of lysine residues on histone and non-histone proteins. In this study, we demonstrate that green tea polyphenols (GTPs) and their major constituent, (-) epigallocatechin-3-gallate (EGCG), activate p53 through acetylation at the Lys373 and Lys382 residues by inhibiting class I HDACs in LNCaP human prostate cancer cells. Treatment of cells with GTPs (2.5-10µg/ml) and EGCG (5-20 µM) resulted in dose- and time-dependent inhibition of class I HDACs (HDAC1, 2, 3 and 8), albeit at varying levels. Discontinuation of treatment with GTP/EGCG resulted in the loss of p53 acetylation at both the sites in these cells. GTP/EGCG treatment also resulted in increased expression of p21/waf1 and Bax at the protein and message levels in these cells. The increased GTP/EGCG-mediated p53 acetylation enhanced its binding on the promoters of p21/waf1 and Bax, which was associated with increased accumulation of cells in the G0/G1 phase of the cell cycle and inductionof apoptosis. Our findings indicate that GTP/EGCG causes acetylation of p53 by inhibiting class I HDACs, a function that is likely to be part of the mechanisms that control the physiological activity of p53.

Int J Oncol. 2012 Jul ;41(1):353-61. Epub 2012 Apr 26. PMID: 22552582


Argania spinosa has antimalarial, antioxidant and anti-breat cancer properties.

INTRODUCTION: In our work, we evaluate the potential antioxidant, antimalarial activity and also activity against human breast cancer cells (MCF7) of Argan fruit extracts using in vitro models to validate the traditional use of this plant. Its chemical composition was also studied to begin the understanding of its activities, waiting to find the structure-activity relationship.RESULTS: Polyphenols (89.4-218.5 eqGallic acid (mg/g dry)), tannins (39.3-214.0 eqCatechin (mg/g dry)), flavonoids (3.4-11.1 eqQuercetin (mg/g dry)) and anthocyanins (0.74-10.92 eqCyanindin (mug/g dry)) were quantified. A good (ethyl acetate and decoction) and moderate (petroleum ether) antioxidant activity were obtained for DPPH (IC(50) 32.3-600.8 microg/ml) and ABTS (IC(50) 11.9-988.8 microg/ml) assays. In addition, we found a good antimalarial activity (IC(50) 35 to>100 microg/ml) and human breast cancer cells activity (IC(50) 42 to>100 microg/ml).CONCLUSIONS: The ethyl acetate extract and the decoction show interesting antimalarial and antioxidant activities. The results indicate a good correlations between anthocyanins quantitiy and the potential antioxidant (R(2)=0.9867) and also to antimalarial activity (R(2)=0.8175).

Phytomedicine. 2010 Feb ;17(2):157-60. Epub 2009 Jul 2. PMID: 19576744


"Curcumin inhibits prostate cancer metastasis in vivo by targeting the inflammatory cytokines CXCL1 and -2."

In America and Western Europe, prostate cancer is the second leading cause of death in men. Emerging evidence suggests that chronic inflammation is a major risk factor for the development and metastatic progression of prostate cancer. We previously reported that the chemopreventive polyphenol curcumin inhibits the expression of the proinflammatory cytokines CXCL1 and -2 leading to diminished formation of breast cancer metastases. In this study, we analyze the effects of curcumin on prostate carcinoma growth, apoptosis and metastasis. We show that curcumin inhibits translocation of NFκB to the nucleus through the inhibition of the IκB-kinase (IKKβ, leading to stabilization of the inhibitor of NFκB, IκBα, in PC-3 prostate carcinoma cells. Inhibition of NFκB activity reduces expression of CXCL1 and -2 and abolishes the autocrine/paracrine loop that links the two chemokinesto NFκB. The combination of curcumin with the synthetic IKKβ inhibitor, SC-541, shows no additive or synergistic effects indicating that the two compounds share the target. Treatment of the cells with curcumin and siRNA-based knockdown of CXCL1 and -2 induce apoptosis, inhibit proliferation and downregulate several important metastasis-promoting factors like COX2, SPARC and EFEMP. In an orthotopic mouse model of hematogenous metastasis, treatment with curcumin inhibits statistically significantly formation of lung metastases. In conclusion, chronic inflammation can induce a metastasis pronephenotype in prostate cancer cells by maintaining a positive proinflammatory and prometastatic feedback loop between NFκB and CXCL1/-2. Curcumin disrupts this feedback loop by the inhibition of NFκB signaling leading to reduced metastasis formation in vivo.

Carcinogenesis. 2012 Dec ;33(12):2507-19. Epub 2012 Oct 5. PMID: 23042094


Targeting Cancer Stem Cells by Curcumin and Clinical Applications.

Curcumin is a well-known dietary polyphenol derived from the rhizomes of turmeric, an Indian spice. The anticancer effect of curcumin has been demonstrated in many cell and animal studies, and recent research has shown that curcumin can target cancer stem cells (CSCs). CSCs are proposed to be responsible for initiating and maintaining cancer, and contribute to recurrence and drug resistance. A number of studies have suggested that curcumin has the potential to target CSCs through regulation of CSC self-renewal pathways (Wnt/β-catenin, Notch, Sonic Hedgehog) and specific microRNAs involved in acquisition of epithelial-mesenchymal transition (EMT). The potential impact of curcumin, alone or in combination with other anticancer agents, on CSCs was evaluated as well. Furthermore, the safety and tolerability of curcumin have been well-established by numerous clinical studies. Importantly, the low bioavailability of curcumin has been dramatically improved through the use of structural analogues or special formulations. More clinical trials are underway to investigate the efficacy of this promising agent in cancer chemoprevention and therapy. In this article, we review the effects of curcumin on CSC self-renewal pathways and specific microRNAs, as well as its safety and efficacy in recent human studies. In conclusion, curcumin could be a very promising adjunct to traditional cancer treatments.

Cancer Lett. 2014 Jan 23. Epub 2014 Jan 23. PMID: 24463298


Blueberry anthocyanins inhibited proliferation and induced apoptosis in oral cancer cells in a dose dependent manner.

Blueberries are an excellent source of dietary polyphenols such as anthocyanins and phenolic acids. In this study, we investigated the ability of anthocyanins from the wild blueberries of Inner Mongolia to suppress the growth of the oral cancer cell line KB. The blueberry anthocyanins were extracted with methanol-containing 0.1% (v/v) hydrochloric acid. Fourteen unique anthocyanins were identified using high-performance liquid chromatography-mass spectrometry (HPLC-MS). The anticancer bioactivity of the extracts on KB cells was analyzed using methylthiazolyl-tetrazolium (MTT), flow cytometry (FCM) and immunocytochemistry. It was shown that the blueberry anthocyanins suppressed the proliferation of KB cells in a dose-dependent manner, as well as induced G2/M cell cycle arrest and apoptosis of oral cancer KB cells. Immunocytochemistry analysis showed that the expression of caspase-9 and cytochrome c were obviously increased after the anthocyanins treatment. Western blot analysis also indicated that the expression of p53 was increased. Methylation-specific PCR (MSP) showed that the amount of unmethylated p53 increased, indicating that the anthocyanins can down-regulate the methylation of p53.

Yi Chuan. 2014 Jun 20 ;36(6):566-73. PMID: 24929515


Effects of natural antioxidants in neurodegenerative disease.

Polyphenols are secondary metabolites with antioxidant properties and are abundant in the diet. Fruits, vegetables, herbs, and various drinks (tea, wine, and juices) are all sources of these molecules. Despite their abundance, investigations into the benefits of polyphenols in human health have only recently begun. Phenolic compounds have received increasing interest because of numerous epidemiological studies. These studies have suggested associations between the consumption of polyphenol-rich aliments and the prevention of chronic diseases, such as cancer, cardiovascular diseases, and neurodegenerative diseases. More specifically, in the last 10 years literature on the neuroprotective effects of a polyphenol-rich diet has grown considerably. It has been demonstrated, in various cell culture and animal models, that these metabolites are able to protect neuronal cells by attenuating oxidative stress and damage. However, it remains unclear as to how these compounds reach the brain, what concentrations are necessary, and what biologically active forms are needed to exert beneficial effects. Therefore, further research is needed to identify the molecular pathways and intracellular targets responsible for polyphenol's neuroprotective effects. The aim of this paper is to present various well-known dietary polyphenols and their mechanisms of neuroprotection with an emphasis on Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis.

Nutr Neurosci. 2012 Jan ;15(1):1-9. PMID: 22305647


An apple flavonoid enriched fraction possessed a significantly stronger antiproliferative and specific action than Sorafenib in vitro.

Apples are a major source of dietary phytochemicals such as flavonoids in the Western diet. Here we report anticancer properties and possible mechanism of action of apple flavonoid-enriched fraction (AF4) isolated from the peels of Northern Spy apples in human hepatocellular carcinoma cells, HepG2. Treatment with AF4 induced cell growth inhibition in HepG2 cells in time- and dose-dependent manner. Concentration of 50 μg/ml (50 μg total monomeric polyphenols/ml) AF4 was sufficient to induce a significant reduction in cell viability within 6 h of treatment (92%, P

Nutr Cancer. 2014 Sep 25:1-10. Epub 2014 Sep 25. PMID: 25256427


Green tea catechins were potent inhibitors of the polo-box domain of polo-like kinase 1.

Polo-like kinase 1 (PLK1) plays crucial functions in multiple stages of mitosis and is considered to be a potential drug target for cancer therapy. The functions of PLK1 are mediated by its N-terminal kinase domain and C-terminal polo-box domain (PBD). Most inhibitors targeting the kinase domain of PLK1 have a selectivity issue because of a high degree of structural conservation within kinase domains of all protein kinases. Here, we combined virtual and experimental screenings to identify green tea catechins as potent inhibitors of the PLK1 PBD. Initially, (-)-epigallocatechin, one of the main components of green tea polyphenols, was found to significantly block the binding of fluorescein-labeled phosphopeptide to the PBD at a concentration of 10 μm. Next, additional catechins were evaluated for their dose-dependent inhibition of the PBD and preliminary structure-activity relationships were derived. Cellular analysis further showed that catechins interfere with the proper subcellular localization of PLK1, lead to cell-cycle arrest in theS and G2M phases, and induce growth inhibition of several human cancer cell types, such as breast adenocarcinoma (MCF7), lung adenocarcinoma (A549), and cervical adenocarcinoma (HeLa). Our data provides new insight into understanding the anticancer activities of green tea catechins.

ChemMedChem. 2014 Sep 5. Epub 2014 Sep 5. PMID: 25196850


Extra-virgin olive oil polyphenols induced strong tumoricidal effects by selectively triggering apoptotic cell death in HER2-positive cells.

Depending on their structure, some polyphenols (e.g. flavonoids) abundantly found in plant-derived beverages such as green tea can efficiently inhibit tyrosine kinase and serine/threonine kinase activities. Extra-virgin olive oil (EVOO - the juice of the olive obtained solely by pressing and consumed without any further refining process) is unique among other vegetable oils because of the high level of naturally occurring phenolic compounds. We explored the ability of EVOO polyphenols to modulate HER2 tyrosine kinase receptor-induced in vitro transformed phenotype in human breast epithelial cells. Using MCF10A normal breast epithelial cells retrovirally engineered to overexpress the wild-type sequence of human HER2, we further determined the relationship between chemical structures of EVOO-derived phenolics and their inhibitory activities on the tyrosine kinase activity of the HER2 oncoprotein. When the activation (phosphorylation) status of HER2 was semi-quantitatively measured the secoiridoids blocked HER2 signaling by rapidly reducing the activation status of the 1248 tyrosine residue (Y1248), the main autophosphorylation site of HER2. EVOO-derived single phenols tyrosol and hydroxytyrosol and the phenolic acid elenolic acid failed to significantly decrease HER2 tyrosine kinase activity. The anti-HER2 tyrosine kinase activity IC50 values were up to 5-times lower in the presence of EVOO-derived lignans and secoiridoids than in the presence of EVOO-derived single phenols and phenolic acids. EVOO polyphenols induced strong tumoricidal effects by selectively triggering high levels of apoptotic cell death in HER2-positive MCF10A/HER2 cells but not in MCF10A/pBABE matched control cells. EVOO lignans and secoiridoids prevented HER2-induced in vitro transformed phenotype as they inhibited colony formation of MCF10A/HER2 cells in soft-agar. Our current findings not only molecularly support recent epidemiological evidence revealing that EVOO-related anti-breast cancer effects primarily affect the occurrence of breast tumors over-expressing the type I receptor tyrosine kinase HER2 but further suggest that the stereochemistry of EVOO-derived lignans and secoiridoids might provide an excellent and safe platform for the design of new HER2 targeted anti-breast cancer drugs.

Int J Oncol. 2009 Jan ;34(1):43-51. PMID: 19082476


Curcumin has established itself as a safe and promising molecule for the prevention and therapy of cancer.

Despite significant advances in treatment modalities over the last decade, neither the incidence of the disease nor the mortality due to cancer has altered in the last thirty years. Available anti-cancer drugs exhibit limited efficacy, associated with severe side effects, and are also expensive. Thus identification of pharmacological agents that do not have these disadvantages is required. Curcumin, a polyphenolic compound derived from turmeric (Curcumin longa), is one such agent that has been extensively studied over the last three to four decades for its potential anti-inflammatory and/or anti-cancer effects. Curcumin has been found to suppress initiation, progression, and metastasis of a variety of tumors. These anti-cancer effects are predominantly mediated through its negative regulation of various transcription factors, growth factors, inflammatory cytokines, protein kinases, and other oncogenic molecules. It also abrogates proliferation of cancer cells by arresting them at different phases of the cell cycle and/or by inducing their apoptosis. The current review focuses on the diverse molecular targets modulated by curcumin that contribute to its efficacy against various human cancers.

Molecules. 2015 ;20(2):2728-69. Epub 2015 Feb 5. PMID: 25665066


There is evidence that pomegranate has a putative anticancerogenic effect in prostate cancer and can safely be used in high doses.

Preclinical in vitro and in vivo studies demonstrate potent effects of pomegranate preparations in cancer cell lines and animal models with chemically induced cancers. We have carried out one systematic review of the effectiveness of pomegranate products in the treatment of cancer and another on their safety. The PubMed search provided 162 references for pomegranate and cancer and 122 references for pomegranate and safety/toxicity. We identified 4 clinical studies investigating 3 pomegranate products, of which one was inappropriate because of the low polyphenol content. The evidence of clinical effectiveness was poor because the quality of the studies was poor. Although there is no concern over safety with the doses used in the clinical studies, pomegranate preparations may be harmful by inducing synthetic drug metabolism through activation of liver enzymes. We have analysed various pomegranate products for their content of anthocyanins, punicalagin, and ellagic acid in order to compare them with the benchmark doses from published data. If the amount of coactive constituents is not declared, patients risk not benefiting from the putative pomegranate effects. Moreover, pomegranate end products are affected by many determinants. Their declaration should be incorporated into the regulatory guidance and controlled before pomegranate products enter the market.

Evid Based Complement Alternat Med. 2015 ;2015:258598. Epub 2015 Mar 1. PMID: 25815026


Polyphenols in pomegranate rind could be a potential treatment to suppress bladder cancer cell proliferation.

miRNAs and their validated miRNA targets appear as novel effectors in biological activities of plant polyphenols; however, limited information is available on miR-34a mediated cytotoxicity of pomegranate rind polyphenols in cancer cell lines. For this purpose, cell viability assay, Realtime quantitative PCR for mRNA quantification, western blot for essential protein expression, p53 silencing by shRNA and miR-34a knockdown were performed in the present study. EJ cell treatment with 100 µg (GAE)/mL PRE for 48 h evoked poor cell viability and caspase-dependent pro-apoptosis appearance. PRE also elevated p53 protein and triggered miR-34a expression. The c-Myc and CD44 were confirmed as direct targets of miR-34a in EJ cell apoptosis induced by PRE. Our results provide sufficientevidence that polyphenols in PRE can be potential molecular clusters to suppress bladder cancer cell EJ proliferation via p53/miR-34a axis. Copyright © 2015 John Wiley&Sons, Ltd.

Phytother Res. 2015 Mar ;29(3):415-22. Epub 2015 Jan 8. PMID: 25572695


A lyophilized grape extract comparable to putative dietary doses induced important morphology changes, migration inhibition, downregulation of undifferentiated stem/stem-like cells markers and EMT.

Natural dietary components are evolutionary-selected molecules able to control inflammation and cancerous transformation and progression. Because many studies assessed the beneficial properties of key molecules extracted from grapes, we aimed at investigating the properties of Liofenol™, a natural red wine lyophilized extract, devoid of alcohol and composed by a miscellaneous of components (polyphenols, flavonoids, anthocyanins). We proved that the colon cancer cell line HCT116 responded to Liofenol™ treatment by reducing their proliferation, in association with an increase of p53 and p21 cell cycle gate keepers. Liofenol™ increased dihydroceramides, sphingolipid mediators involved in cell cycle arrest and reduced proliferation rate. We observed a strong induction of antioxidant response, with the activation of the transcriptional factor Nrf2, involved in redox homeostasis and differentiation, without altering tumor sensitivity to chemotherapy. Liofenol™ induced an important morphology change in HCT116 cells, migration inhibition, undifferentiated stem/stem-like cells markers downregulation, and E-cadherin downregulation, interested in epithelia to mesenchymalmalignant transition. We conclude that lyophilized grape extract, at dose comparable to putative dietary doses, can activate molecular pathways, involving Nrf2 signaling and the modulation of structural and signaling sphingolipid mediators that cooperate in promoting differentiation and reducing proliferation of digestive tract cancer cells.

Nutr Cancer. 2015 Apr ;67(3):494-503. Epub 2015 Feb 23. PMID: 25705818


The overall objective of the present review is to update and discuss the key findings, from recent in vivo studies, on the effects of strawberries on human health.

Since a high intake of fruits and vegetables is inversely related to the incidence of several degenerative diseases, the importance of a balanced diet in relation to human health has received increased consumer attention worldwide. Strawberries (Fragaria X ananassa, Duch.) are a rich source of a wide variety of nutritive compounds such as sugars, vitamins, and minerals, as well as non-nutritive, bioactive compounds such as flavonoids, anthocyanins and phenolic acids. All of these compounds exert a synergistic and cumulative effect on human health promotion and in disease prevention. Strawberry phenolics are indeed able (i) to detoxify free radicals blocking their production, (ii) to modulate the expression of genes involved in metabolism, cell survival and proliferation and antioxidant defense, and (iii) to protect and repair DNA damage. The overall objective of the present review is to update and discuss the key findings, from recent in vivo studies, on the effects of strawberries on human health. Particular attention will be paid to the molecular mechanisms proposed to explain the health effects of polyphenols against the most common diseases related to oxidative stress driven pathologies, such as cancer, cardiovascular diseases, type II diabetes, obesity and neurodegenerative diseases, and inflammation.

Food Funct. 2015 Mar 24. Epub 2015 Mar 24. PMID: 25803191


Epigallocatechin-3-gallate (EGCG) can protect cochlear hair cells from ototoxic drug gentamicin.

Notch signalling pathway plays an essential role in the development of cochlea, which inhibits the proliferation of hair cells. Epigallocatechin-3-gallate (EGCG) is the most abundant polyphenol in green tea, which presents strong antioxidant activation and has been applied for anti-cancer and anti-inflammatory. In this study, we treated the cochlear explant cultures with EGCG and found that EGCG can protect cochlear hair cells from ototoxic drug gentamicin. We demonstrated that EGCG could down-regulate the expression of Notch signalling pathway target genes, such as Hes1, Hes5, Hey1 and Hey5. However, the Notch pathway ligands such as Delta1, Jag1 and Jag2 were not affected by EGCG. To further illustrate the mechanism of recover cochlear hair cells, we demonstrated that EGCG inhibited the activity ofγ-secrectase to suppress Notch signalling pathway and promoted the proliferation and regeneration of hair cells in the damaged cochlea. Our results suggest for the first time the role of EGCG as an inhibitor of the Notch signalling pathway, and support its potential value in hearing-impaired recovery in clinical therapy.

Neurochem Res. 2015 Apr 21. Epub 2015 Apr 21. PMID: 25896296


Dietary flavonoids critically influence several cellular and immune processes associated with the development and progression of cancer.

The flavonoids are polyphenolic compounds found as integral components of the human diet. They are universally present as constituents of flowering plants, particularly of food plants. The flavonoids are phenyl substituted chromones (benzopyran derivatives) consisting of a 15-carbon basic skeleton (C6-C3-C6), composed of a chroman (C6-C3) nucleus (the benzo ring A and the heterocyclic ring C), also shared by the tocopherols, with a phenyl (the aromatic ring B) substitution usually at the 2-position. Different substitutions can typically occur in the rings, A and B. Several plants and spices containing flavonoid derivatives have found application as disease preventive and therapeutic agents in traditional medicine in Asia for thousands of years. The selection of a particular food plant, plant tissue or herb for its potential health benefits appears to mirror its flavonoid composition. The much lower risk of colon, prostate and breast cancers in Asians, who consume more vegetables, fruits and tea than populations in the Western hemisphere do, raises the question of whether flavonoid components mediate the protective effects of diets rich in these foodstuffs by acting as natural chemopreventive and anticancer agents. An impressive body of information exists on the antitumor action of plantflavonoids. In vitro work has concentrated on the direct and indirect actions of flavonoids on tumor cells, and has found a variety of anticancer effects such as cell growth and kinase activity inhibition, apoptosis induction, suppression of the secretion of matrix metalloproteinases and of tumor invasive behavior. Furthermore, some studies have reported the impairment of in vivo angiogenesis by dietary flavonoids. Experimental animal studies indicate that certain dietary flavonoids possess antitumor activity. The hydroxylation pattern of the B ring of the flavones and flavonols, such as luteolin and quercetin, seems to critically influence their activities, especially the inhibition of protein kinase activity and antiproliferation. The different mechanisms underlying the potential anticancer action of plant flavonoids await further elucidation. Certain dietary flavonols and flavones targeting cell surface signal transduction enzymes, such as protein tyrosine and focal adhesion kinases, and the processes of angiogenesis appear to be promising candidates as anticancer agents. Further in vivo studies of these bioactive constituents is deemed necessary in order to develop flavonoid-based anticancer strategies. In view of the increasing interest in the association between dietary flavonoids and cancer initiation and progression, this important field is likely to witness expanded effort and to attract and stimulate further vigorous investigations.

In Vivo. 2005 Sep-Oct;19(5):895-909. PMID: 16097445


GSE/GSP ameliorates some of the cytotoxic effects on normal cells/tissues induced by chemo drugs and radiotherapy.

Grapes are one of the most consumed fruits in the world and are rich in polyphenols. Grape seed proanthocyanidins (GSP) have demonstrated chemopreventive and/or chemotherapeutic effects in various cancer cell cultures and animal models. The clinical efficacy of chemotherapy is often limited by its adverse effects. Several studies show that reactive oxygen species mediate the cardiotoxicity and neurotoxicity induced by various cancer chemotherapeutic agents. This implies that concomitant administration of antioxidants may prevent these adverse effects. The review was carried out in accordance with the PRISMA guidelines. An electronic search strategy in Medline and Embase databases was conducted. Of the 41 studies reviewed, 27 studied GSP while the remainder (14) studied grape seed or skin extracts (GSE). All the studies were published in English, except 2 in Chinese. A significant percentage (34%) of the studies we reviewed assessed the effect of GSE or GSP on cardiotoxicity induced by chemotherapy. Doxorubicin was the most common chemotherapeutic drug studied followed by cisplatin. Research studies that assessed the effect of GSE or GSP on radiation treatment accounted for 22% of the articles reviewed. GSE/GSP ameliorates some of the cytotoxic effects on normal cells/tissues induced by chemo/radiotherapy.

Nutr Cancer. 2015 Apr 16:1-11. Epub 2015 Apr 16. PMID: 25880972


This review discusses the beneficial effects of tea and tea components in bladder cancer prevention and treatment of bladder cancers.

The leaves of Camellia sinensis (L.) are the source of tea, the second most consumed beverage worldwide. Tea contains several chemical compounds such as polyphenols (mainly catechins), caffeine, theophylline, L-theanine, among many others. Polyphenolic compounds are the main responsible for its significant antioxidant properties and anticarcinogenic potential. Bladder cancer is one of the most common types of cancer, and its progression and onset are thought to be controlled by dietary and lifestyle factors. Epidemiological studies showed that the regular consumption of tea can be a preventive factor for this type of cancer, and several in vivo and in vitro studies reported that tea and its components may interfere in the cancer cells' signaling, preventing the bladder tumor progression. The mechanisms responsible for this protection include deregulation of cell cycle, induction of apoptosis while protecting the surrounding healthy bladder cells, inhibition of metastization processes, among others. Herein, we discuss the potential beneficial effects of tea and tea components in bladder cancer prevention and/or treatment, and how they can be helpful in finding new therapeutic strategies to treat this type of cancer.

Anticancer Agents Med Chem. 2014 Dec 3. Epub 2014 Dec 3. PMID: 25495463


In this mini-review, selected flavonoids which are a group of plant polyphenols that are able to regulate angiogenesis in vitro and in vivo systems are discussed.

Discovery of novel drugs that are able to prevent angiogenesis is a fast growing branch of cancer research. Current approaches to cancer chemotherapy include the use of alkylating agents, antimetabolites, antitumor antibiotics, platinum analogs and drugs derived from natural compounds. However, most of the currently used chemotherapeutic drugs have adverse side effects on normal healthy cells. In addition to the classical targets of cancer chemotherapy, prevention of angiogenesis through the regulation of indigenous angiogenic factors is a leading approach of developing selective novel anticancer drugs. Because of their low toxicity, there is increasing interest in exploring specific dietary phytochemicals as possible antiangiogenic agents. In this mini-review, selected flavonoids (e.g., apigenin, luteolin, quercetin and epigallocatechin-3- gallate, which are a group of plant polyphenols) that are able to regulate angiogenesis in in vitro and in vivo systems are discussed in the light of their potential to be exploited as novel anticancer drugs.

Mini Rev Med Chem. 2015 ;15(6):479-89. PMID: 25873069


Chokeberry juice has chemotherapeutic properties against acute lymphoblastic leukemia by selectively targeting lymphoblast-derived tumor cells.

Polyphenols are natural compounds widely present in fruits and vegetables, which have antimutagenic and anticancer properties. The aim of the present study was to determine the anticancer effect of a polyphenol-rich Aronia melanocarpa juice (AMJ) containing 7.15 g/L of polyphenols in the acute lymphoblastic leukemia Jurkat cell line, and, if so, to clarify the underlying mechanism and to identify the active polyphenols involved. AMJ inhibited cell proliferation, which was associated with cell cycle arrest in G(2)/M phase, and caused the induction of apoptosis. These effects were associated with an upregulation of the expression of tumor suppressor p73 and active caspase 3, and a downregulation of the expression of cyclin B1 and the epigenetic integrator UHRF1. AMJ significantly increased the formation of reactive oxygen species (ROS), decreased the mitochondrial membrane potential and caused the release of cytochrome c into the cytoplasm. Treatment with intracellular ROS scavengers prevented the AMJ-induced apoptosis and upregulation of the expression of p73 and active caspase 3. The fractionation of the AMJ and the use of identified isolated compounds indicated that the anticancer activity was associated predominantly with chlorogenic acids, some cyanidin glycosides, and derivatives of quercetin. AMJ treatment also induced apoptosis of different human lymphoblastic leukemia cells (HSB-2, Molt-4 and CCRF-CEM). In addition, AMJ exerted a strong pro-apoptotic effect in human primary lymphoblastic leukemia cells but not in human normal primary T-lymphocytes. Thus, the present findings indicate that AMJ exhibits strong anticancer activity through a redox-sensitive mechanism in the p53-deficient Jurkat cells and that this effect involves several types of polyphenols. They further suggest that AMJ has chemotherapeutic properties against acute lymphoblastic leukemia by selectively targeting lymphoblast-derived tumor cells.

PLoS One. 2012 ;7(3):e32526. Epub 2012 Mar 8. PMID: 22412883


Polyphenol rich chokeberry juice exhibited anti-proliferative effects in Caco-2 cancer colon cells.

Berries and red fruits are important dietary sources of polyphenols [1]. In vitro and animal studies have demonstrated the bioavailability and the anti-proliferative and anticarcinogenic properties of these fruits or of their phenolic components [2, 3]. Consumption of berries may contribute to the reduction of colon cancer by mechanisms not yet understood. Gene expression analysis using microarrays allows for a more comprehensive study of the possible molecular mechanisms by which food or food components may prevent certain cancers of the gastrointestinal tract [4]. The aim of this research is to investigate the anti-proliferative effects of a polyphenol-rich berry juice on a human model of colon cancer cells and its association to transcriptional changes in relation to colon cancer.

Genes Nutr. 2007 Oct ;2(1):111-3. PMID: 18850155


Oleuropein effectively inhibited cell viability and induced apoptosis in HepG2 human hepatoma cells in a dose‑dependent manner, through activation of the caspase pathway.

Oleuropein is a polyphenol, that is found in extra‑virgin olive oil. Previous studies have shown that oleuropein inhibits cell proliferation and induces apoptosis in breast cancer, colorectal cancer and thyroid cancer. The aim of the present study was to investigate the effects of oleuropein in hepatocellular carcinoma (HCC) cells. The results of Cell Counting Kit 8 and flow cytometric analysis indicated that oleuropein effectively inhibited cell viability and induced apoptosis in HepG2 human hepatoma cells in a dose‑dependent manner, through activation of the caspase pathway. Proapoptotic Bcl‑2 family members, BAX and Bcl‑2, were involved in oleuropein‑induced apoptosis. The phosphatidylinositol 3‑kinase/protein kinase B (PI3K/AKT) signaling pathway was also shown to be involved in this process. Oleuropein was demonstrated to suppress the expression of activated AKT. In addition, AKT overexpression promoted cell survivalfollowing treatment with oleuropein, while inhibition of AKT promoted cell death. Furthermore, the data demonstrated that oleuropein induces the production of reactive oxygen species (ROS) and that the function of oleuropein is, at least partially, ROS‑dependent. These results suggest that oleuropein may be a promising novel chemotherapeutic agent in hepatocellular carcinoma.

Mol Med Rep. 2015 Jun ;11(6):4617-24. Epub 2015 Jan 28. PMID: 25634350


This review summarizes that polyphenols and their effects greatly depend on the applied dose, the cell type, exposure time and environmental conditions.

Various plant polyphenols have been recognized as redox active molecules. This review discusses some aspects of polyphenols' modes of redox action, corresponding structure-activity relationships and their potential to be applied as adjuvants to conventional cytostatic drugs. Polyphenols' antioxidative capacity has been discussed as the basis for targeting oxidative stress and, consequently, for their chemopreventive and anti-inflammatory activities, which may alleviate side-effects on normal cells arising from oxidative stress caused by cytostatics. Some polyphenols may scavenge various free radicals directly, and some of them are found to suppress free radical production through inhibiting NADPH oxidases and xanthine oxidase. Additionally, polyphenols may increase antioxidative defense in normal cells by increasing the activity of NRF2, transcription factor for many protective proteins. The activation of the NRF2-mediated signaling pathways in cancer cells results in chemoresistance. Luteolin, apigenin and chrysin reduce NRF2 expression and increase the chemosensitivity of cancer cells to cytostatic drugs. Their common 5,7-dihydroxy-4H-chromen-4-one moiety, may represent a starting pharmacophore model for designing novel, non-toxic compounds for overcoming chemoresistance. However, prooxidative activity of some polyphenols (quercetin, EGCG) may also provide a basis for their use as chemotherapeutic adjuvants since they may enhance cytotoxic effects of cytostatics selectively on cancer cells. However, considerable caution is needed in applying polyphenols to anticancer therapy, since their effects greatly depend on the applied dose, the cell type, exposure time and environmental conditions.

Curr Top Med Chem. 2015 ;15(5):496-509. PMID: 25665579


A review evaluating the modulation of miRNAs by dietary agents, which could potentially be exploited for inhibition of mutagenesis and carcinogenesis.

MicroRNAs (miRNAs) have been implicated in many biological processes, cancer, and other diseases. In addition, miRNAs are dysregulated following exposure to toxic and genotoxic agents. Here we review studies evaluating modulation of miRNAs by dietary and pharmacological agents, which could potentially be exploited for inhibition of mutagenesis and carcinogenesis. This review covers natural agents, including vitamins, oligoelements, polyphenols, isoflavones, indoles, isothiocyanates, phospholipids, saponins, anthraquinones and polyunsaturated fatty acids, and synthetic agents, including thiols, nuclear receptor agonists, histone deacetylase inhibitors, antiinflammatory drugs, and selective estrogen receptor modulators. As many as 145 miRNAs, involved in the control of a variety of carcinogenesis mechanisms, were modulated by these agents, either individually or in combination. Most studies used cancer cells in vitro with the goal of modifying their phenotype by changing miRNA expression profiles. In vivo studies evaluated regulation of miRNAs by chemopreventive agents in organs of mice and rats, either untreated or exposed to carcinogens, with the objective of evaluating their safety and efficacy. The tissue specificity of miRNAs could be exploited for the chemoprevention of site-specific cancers, and the study of polymorphic miRNAs is expected to predict the individual response to chemopreventive agents as a tool for developing new prevention strategies.

Mutat Res. 2012 Oct-Dec;751(2):287-303. Epub 2012 Jun 7. PMID: 22683846


Overexpression of miR-7-1 can highly potentiate efficacy of EGCG for induction of apoptosis in human malignant neuroblastoma cells.

Neuroblastoma is an extracranial solid tumor that usually occurs in infants and children. Malignant neuroblastomas remain mostly refractory to currently available chemotherapeutic agents. So, new therapeutic agents and their molecular mechanisms for induction of cell death must be explored for successful treatment of human malignant neuroblastomas. Two polyphenolic compounds, which are abundant in green tea, are (-)-epigallocatechin (EGC) and (-)-epigallocatechin-3-gallate (EGCG) that possess impressive anti-cancer properties. It is not known yet whether EGC and EGCG can modulate the levels of expression of specific microRNAs (miRs) for induction of apoptosis in human malignant neuroblastomas. In this investigation, we revealed that treatment with EGC or EGCG caused induction of apoptosis with significant changes in expression of specific oncogenic miRs (OGmiRs) and tumor suppressor miRs (TSmiRs) in human malignant neuroblastoma SH-SY5Y and SK-N-DZ cell lines. Treatment of both cell lines with either 50μM EGC or 50 μM EGCG decreased expression of the OGmiRs (miR-92, miR-93, and miR-106b) and increased expression of the TSmiRs (miR-7-1, miR-34a, and miR-99a) leading to induction of extrinsic and intrinsic pathways of apoptosis. Our data also demonstrated that overexpression of miR-93 decreased efficacy while overexpression of miR-7-1 increased efficacy of the green tea polyphenols for induction of apoptosis in both cell lines. In conclusion, our current investigation clearly indicates that overexpression of miR-7-1 can highly potentiate efficacy of EGCG for induction of apoptosis in human malignant neuroblastoma cells.

Neurochem Res. 2013 Feb ;38(2):420-32. Epub 2012 Nov 30. PMID: 23192662


Antioxidants have been shown to significantly influence cell growth, DNA repair and mitochondrial membrane-mediated apoptosis.

Many dietary compounds are known to have health benefits owing to their antioxidative and anti-inflammatory properties. To determine the molecular mechanism of these food-derived compounds, we analyzed their effect on various genes related to cell apoptosis, DNA damage and repair, oxidation and inflammation using in vitro cell culture assays. This review further tests the hypothesis proposed previously that downstream products of COX-2 (cyclooxygenase-2) called electrophilic oxo-derivatives induce antioxidant responsive elements (ARE), which leads to cell proliferation under antioxidative conditions. Our findings support this hypothesis and show that cell proliferation was inhibited when COX-2 was down-regulated by polyphenols and polysaccharides. Flattened macrophage morphology was also observed following the induction of cytokine production by polysaccharides extracted from viili, a traditional Nordic fermented dairy product. Coix lacryma-jobi (coix) polysaccharides were found to reduce mitochondrial membrane potential and induce caspase-3- and 9-mediated apoptosis. In contrast, polyphenols from blueberries were involved in the ultraviolet-activated p53/Gadd45/MDM2 DNA repair system by restoring the cell membrane potential. Inhibition of hypoxia-inducible factor-1 by saponin extracts of ginsenoside (Ginsen) and Gynostemma and inhibition of S100A4 by coix polysaccharides inhibited cancer cell migration and invasion. These observations suggest that antioxidants and changes in cell membrane potential are the major driving forces that transfer signals through the cell membrane into the cytosol and nucleus, triggering gene expression, changes in cell proliferation and the induction of apoptosis or DNA repair.

Int J Mol Sci. 2014 ;15(9):16226-45. Epub 2014 Sep 15. PMID: 25226533


Curcuma rhizome, a main representant of Zingiberaceae family may be a promising natural source for active compounds against malignant melanoma.

BACKGROUND: Curcuma longa Linnaeus and Zingiber officinale Roscoe are two main representatives of Zingiberaceae family studied for a wide range of therapeutic properties, including: antioxidant, anti-inflammatory, anti-angiogenic, antibacterial, analgesic, immunomodulatory, proapoptotic, anti-human immunodeficiency virus properties and anticancer effects. This study was aimed to analyse the ethanolic extracts of Curcuma rhizome (Curcuma longa Linnaeus) and Zingiber rhizome (Zingiber officinale Roscoe) in terms of polyphenols, antioxidant activity and anti-melanoma potential employing the B164A5 murine melanoma cell line.RESULTS: In order to evaluate the total content of polyphenols we used Folin-Ciocâlteu method. The antioxidant activity of the two ethanolic extracts was determined by DPPH assay, and for the control of antiproliferative effect it was used MTT proliferation assay, DAPI staining and Annexin-FITC-7AAD double staining test. Results showed increased polyphenols amount and antioxidant activity for Curcuma rhizome ethanolic extract. Moreover, 100 μg/ml of ethanolic plant extract from both vegetal products presented in a different manner an antiproliferative, respectively a proapoptotic effect on the selected cell line.CONCLUSIONS: The study concludes that Curcuma rhizome may be a promising natural source for active compounds against malignant melanoma.

Biol Res. 2015 Jan 12 ;48(1):1. Epub 2015 Jan 12. PMID: 25654588


COMT inhibition may increase the anti-cancer properties of tea polyphenols and the combination may serve as a novel approach or supplemental treatment for breast cancer chemotherapy.

Tea is one of the most popular beverages in the world and has been studied extensively as a health-promoting beverage that may act to prevent a number of chronic diseases and cancers. (-)-Epigallocatechin gallate [(-)-EGCG], a major component in green tea, is unstable under physiological conditions and methylation of (-)-EGCG by catechol-Omicron-methyltransferase (COMT) is a modification that reduces the biological activity of (-)-EGCG. In the current study, we hypothesized that suppression of COMT activity in human breast cancer cells could increase the proteasome-inhibitory potency of (-)-EGCG and therefore enhance its tumor cell growth-inhibitory activity. We first determined the COMT genotype and basal levels of COMT activity in various human breast cancer cell lines. Furthermore, when breast cancer MDA-MB-231 cells containing high COMT activity were tested, the diminished COMT activity apparently increased the effectiveness of (-)-EGCG via augmented proteasome inhibition and apoptosis induction. This study supplements the previous findings that methylated (-)-EGCG is less bioactive and supports the notion that COMT inhibition may increase the anti-cancer properties of tea polyphenols and the combination may serve as a novel approach or supplemental treatment for breast cancer chemotherapy.

Oncol Rep. 2010 Aug ;24(2):563-9. PMID: 20596647


EGCG is a potent apoptosis inducer that functions exclusively through a p53-dependent pathway in A549 cells.

The effects of green tea polyphenols on cultured cancer cells have been well characterized, especially the effects of epigallocatechin-3-gallate (EGCg), since EGCg suppresses oncogenic signaling pathways and induces cell cycle arrest or apoptosis by regulating cell cycle-associated proteins. In the present study, we attempted to identify signaling pathways or target molecules regulated by each of or a mixture of green tea polyphenols, including epicatechin (EC), epicatechin-3-gallate (ECg), epigallocatechin (EGC), and EGCg, in the human lung cancer cell line A549. ECg, EGC, and a catechin mixture, in addition to EGCg, significantly decreased cell viability. In contrast, caspase 3/7 activity, an apoptosis indicator, was specifically induced by EGCg. By conducting a series of luciferase-based reporter assays, we revealed that the catechin mixture only up-regulates the p53 reporter. EGCg was a more potent inducer of p53-dependent transcription, and this induction was further supported by the induced level of p53 protein. RNA interference (RNAi)-mediated p53 knockdown completely abolished EGCg-induced apoptosis. Finally, a proteome and western blot analysis using approximately 70 different antibodies failed to detect up-regulated proteins in catechin mixture-treated A549 cells. Taken together, these results indicate that EGCg, among several green tea polyphenols, is a potent apoptosis inducer that functions exclusively through a p53-dependent pathway in A549 cells.

Toxicol In Vitro. 2009 Aug ;23(5):834-9. Epub 2009 May 3. PMID: 19406223


Curcumin and epigallocatechin-3-gallate in combination could enhance the toxicity of DOX and increase the intracellular level of DOX in resistant MCF-7 cells.

Drug resistance remains an on-going challenge in breast cancer chemotherapy. Combination of two or more drugs is an effective strategy to access context-specific multiple targets and overcome undesirable toxicity that is almost inevitable in single-drug chemotherapy. Many plant food-derived polyphenolic compounds have been proven to modulate many key factors responsible for cancer drug resistance, which makes them a promising group of low toxicity candidates for reversing cancer resistance. In this study, we analyzed the combination effect of two chemopreventive polyphenols, curcumin (Cur) and epigallocatechin-3-gallate (EGCG), in combating resistant breast cancer. Our present results showed that EGCG significantly enhanced the growth inhibition and apoptosis in both doxorubicin (DOX)-sensitive and resistant MCF-7 cells induced by Cur. The mechanism may be related to the further activation of caspase-dependent apoptotic signaling pathways and the enhanced cellular incorporation of Cur by inhibiting P-glycoprotein (P-gp) pump function. Moreover, Cur and EGCG in combination could enhance the toxicity of DOX and increase the intracellular level of DOX in resistant MCF-7 cells. Our findings with this practical combination of Cur and EGCG encourage us to move on to a promising strategy for successful treatment of human breast cancer resistance by combining two low-toxic chemotherapeutic agents from diet.

Am J Chin Med. 2014 ;42(5):1279-300. PMID: 25242081


A polyphenol rich litchi seed extract could serve as a potential chemopreventive agent for colorectal cancer.

The Litchi (Litchi chinensis) fruit products possess rich amounts of flavanoids and proanthocyanidins. Its pericarp has been shown to inhibit breast and liver cancer cell growth. However, the anticolorectal cancer effect of Litchi seed extract has not yet been reported. In this study, the effects of polyphenol-rich Litchi seed ethanol extract (LCSP) on the proliferation, cell cycle, and apoptosis of two colorectal cancer cell lines Colo320DM and SW480 were examined. The results demonstrated that LCSP significantly induced apoptotic cell death in a dose-dependent manner and arrested cell cycle in G2/M in colorectal carcinoma cells. LCSP also suppressed cyclins and elevated the Bax : Bcl-2 ratio and caspase 3 activity. This study provides in vitro evidence that LCSP serves as a potential chemopreventive agent for colorectal cancer.

J Biomed Biotechnol. 2012 ;2012:341479. Epub 2012 Oct 3. PMID: 23093841


Whole-grape products are safer choices for better health and disease prevention. But for advanced disease conditions, individual grape ingredients or combinations appear to be better.

The grape antioxidant resveratrol has been a topic of intense research for the past three decades. Resveratrol and other grape ingredients, as well as whole-grape products, have shown considerable promise in health promotion and disease management. Phytochemically, whole grape represents a natural combination of resveratrol and other phytonutrients, as it contains several catechins, anthocyanins, polyphenols, and flavonols. Thus, whole grape products or specific combinations of grape constituents provide us with the possibility of synergistic interactions leading to improved efficacy. Recent research has suggested that whole-grape products may help in maintaining heart health and protect against aging, aging-associated diseases, neurodegeneration, and some cancers. On the basis of available recent literature, the grape fruit or whole-grape products seem to be safer choices for better health and disease prevention. However, for advanced disease conditions, individual grape ingredients (such as resveratrol) or combinations of multiple ingredients, together with existing therapies, appear to be better approaches. Further clinical studies are needed to understand the benefits of grapes and their products in the prevention and management of specific diseases.

Ann N Y Acad Sci. 2015 Jun 22. Epub 2015 Jun 22. PMID: 26099945


Gallic acid could be a potential candidate for the development of anti-HPV agents.

The high-risk human papillomaviruses (HPV) that infect the anogenital tract are strongly associated with the development of cervical carcinoma, which is the second most common cancer in women worldwide. Therapeutic drugs specifically targeting HPV are not available. Polyphenolic compounds have gained considerable attention because of their cytotoxic effects against a variety of cancers and certain viruses. In this study, we examined the effects of several polyphenols on cellular proliferation and death of the human cervical cancer cells and human cervical epithelial cells containing stable HPV type 16 episomes (HPVep). Our results show that three polyphenols inhibited proliferation of HeLa cells dose-dependently. Furthermore, one of the examined polyphenols, gallic acid (GA), also inhibited the proliferation of HPVep cells and exhibited significant specificity towards HPV-positive cells. The anti-proliferative effect of GA on HPVep and HeLa cells was associated with apoptosis and upregulation of p53. These results suggest that GA can be a potential candidate for the development of anti-HPV agents. This article is protected by copyright. All rights reserved.

J Med Virol. 2015 Jun 9. Epub 2015 Jun 9. PMID: 26059022


This report reviews current knowledge on the anticancer effects of combinations of polyphenols or polyphenols and anticancer drugs.

Carcinogenesis is a multistep process triggered by genetic alterations that activate different signal transduction pathways and cause the progressive transformation of a normal cell into a cancer cell. Polyphenols, compounds ubiquitously expressed in plants, have anti-inflammatory, antimicrobial, antiviral, anticancer, and immunomodulatory properties, all of which are beneficial to human health. Due to their ability to modulate the activity of multiple targets involved in carcinogenesis through direct interaction or modulation of gene expression, polyphenols can be employed to inhibit the growth of cancer cells. However, the main problem related to the use of polyphenols as anticancer agents is their poor bioavailability, which might hinder the in vivo effects of the single compound. In fact, polyphenols have a poor absorption and biodistribution, but also a fast metabolism and excretion in the human body. The poor bioavailability of a polyphenol will affect the effective dose delivered to cancer cells. One way to counteract this drawback could be combination treatment with different polyphenols or with polyphenols and other anti-cancer drugs, which can lead to more effective antitumor effects than treatment using only one of the compounds. This report reviews current knowledge on the anticancer effects of combinations of polyphenols or polyphenols and anticancer drugs, with a focus on their ability to modulate multiple signaling transduction pathways involved in cancer.

Int J Mol Sci. 2015 ;16(5):9236-82. Epub 2015 Apr 24. PMID: 25918934


An ellagic acid derivative efficiently inhibits colon cancer cell growth through a mechanism involving WNT16.

Ellagic acid (EA) and some derivatives have been reported to inhibit cancer cell proliferation, induce cell cycle arrest, and modulate some important cellular processes related to cancer. This study aimed to identify possible structure-activity relationships of EA and some in vivo derivatives in their antiproliferative effect on both human colon cancer and normal cells, and to compare this activity with that of other polyphenols. Our results showed that 4,4'-di-O-methylellagic acid (4,4'-DiOMEA) was the most effective compound in the inhibition of colon cancer cell proliferation. 4,4'-DiOMEA was 13-fold more effective than other compounds of the same family. In addition, 4,4'-DiOMEA was very active against colon cancer cells resistant to the chemotherapeutic agent 5-fluoracil, whereas no effect was observed in nonmalignant colon cells. Moreover, no correlation between antiproliferative and antioxidant activities was found, further supporting that structure differences might result in dissimilar molecular targets involved in their differential effects. Finally, microarray analysis revealed that 4,4'-DiOMEA modulated Wnt signaling, which might be involved in the potential antitumor action of this compound. Our results suggest that structural-activity differences between EA and 4,4'-DiOMEA might constitute the basis for a new strategy in anticancer drug discovery based on these chemical modifications.

J Pharmacol Exp Ther. 2015 May ;353(2):433-44. Epub 2015 Mar 10. PMID: 25758919


The activation of EpRE/ARE system was up to four fold higher than the sum of the activities of the single ingredients.

Epidemiological studies have consistently shown that regular consumption of fruits and vegetables is strongly associated with reduced risk of developing chronic diseases, such as cancer. It is now accepted that the actions of any specific phytonutrient alone do not explain the observed health benefits of diets rich in fruits and vegetables as nutrients that were taken alone in clinical trials did not show consistent preventive effects. The considerable cost and complexity of such clinical trials requires prudent selection of combinations of ingredients rather than single compounds. Indeed, synergistic inhibition of prostate and mammary cancer cell growth was evident when using combinations of low concentrations of various carotenoids or carotenoids with retinoic acid and the active metabolite of vitamin-D. In this study we aimed to develop simple and sensitive in vitro methods which provide information on potent combinations suitable for inclusion in clinical studies for cancer prevention. We, thus, used reporter gene assays of the transcriptional activity of the androgen receptor in hormone-dependent prostate cancer cells and of the electrophile/antioxidant response element (EpRE/ARE) transcription system. We found that combinations of several carotenoids (e.g., lycopene, phytoene and phytofluene), or carotenoids and polyphenols (e.g., carnosic acid and curcumin) and/or other compounds (e.g., vitamin E) synergistically inhibit the androgen receptor activity and activate the EpRE/ARE system. The activation of EpRE/ARE was up to four fold higher than the sum of the activities of the single ingredients, a robust hallmark of synergy. Such combinations can further be tested in the more complex in vivo models and human studies.

Arch Biochem Biophys. 2015 Apr 15 ;572:28-35. Epub 2015 Feb 21. PMID: 25711533


Anthocyanins from black rice could suppress CAL 27 cell metastasis by reduction of MMP-2, MMP-9, and NF-κB p65 expression.

Aside from the commonly known white rice lines, colored varieties also exist. These varieties have historically been used in Chinese medicine. Anthocyanins, a large group of natural polyphenols existing in a variety of daily fruits and vegetables, have been widely recognized as cancer chemopreventive agents. The primary objective of cancer treatment strategies has traditionally focused on preventing the occurrence of metastasis. In this research the antimetastatic mechanism of anthocyanins on the invasion/migration of human oral CAL 27 cells was performed using a transwell to quantify the migratory potential of CAL 27 cells and the results show that anthocyanins can inhibit the in vitro migration and invasion of CAL 27 cancer cells. In addition, the gelatin zymography assay indicated that anthocyanins inhibited the activity of matrix metalloproteinases-2 (MMP-2). Western blotting assay also demonstrated that anthocyanins inhibited the associated protein expression of migration/invasion of CAL 27 cell. Immunofluorescence staining proved that anthocyanins inhibited nuclear factor kappa B p65 (NF-κB p65) expressions. These results demonstrated that anthocyanins from a species of black rice (selected purple glutinous indica rice cultivated at Asia University) could suppress CAL 27 cell metastasis by reduction of MMP-2, MMP-9, and NF-κB p65 expression through the suppression of PI3K/Akt pathway and inhibition of NF-κB levels.

Nutr Cancer. 2015 ;67(2):327-38. Epub 2015 Feb 6. PMID: 25658905


Soybean or soy food compounds which exhibit anti-inflammatory activity in some diseases via the suppression of inflammatory pathways.

Inflammation is a natural response of living organisms to the presence of internal and external substances, and includes uncontrolled and low-grade inflammations. Uncontrolled inflammation often results in chronic diseases such as arthritis, autoimmune disorders, cancer, dementia, diabetes, neurodegeneration, and vascular disease. In contrast, low-grade inflammation has been recognized as the link between adiposity and the risk of chronic metabolic disorders. Elevated concentrations of inflammatory markers such as pro-inflammatory cytokines and inflammatory mediators have been observed in obese individuals. Through evolution, plants have developed phytochemicals to fight inflammations and infections. Most of them belong to the chemical group of alkaloids, coumarins, flavonoids, polyphenols, and terpenoids. Soybean consumption can play a role in the modulation of inflammatory markers through their bioactive compounds, such as isoflavones, saponins, and flavonoids. The application of phytochemicals for medical care has increased significantly during the last few years. Currently, there is a renewed interest in the search for new phytochemicals that could be developed into useful anti-inflammatory agents to reduce the risk of many diseases. This review article presents and discusses the results of a literature search on recent findings regarding soybean or processed soy food compounds which exhibit anti-inflammatory activity in some diseases via the suppression of inflammatory pathways.

Recent Pat Food Nutr Agric. 2015 Jun 29. Epub 2015 Jun 29. PMID: 26118769


The current review provides an updated overview of the metabolism and mechanism of action of curcumin in various organ pathophysiologies.

The concept of using phytochemicals has ushered in a new revolution in pharmaceuticals. Naturally occurring polyphenols (like curcumin, morin, resveratrol, etc.) have gained importance because of their minimal side effects, low cost and abundance. Curcumin (diferuloylmethane) is a component of turmeric isolated from the rhizome of Curcuma longa. Research for more than two decades has revealed the pleiotropic nature of the biological effects of this molecule. More than 7000 published articles have shed light on the various aspects of curcumin including its antioxidant, hypoglycemic, anti-inflammatory and anti-cancer activities. Apart from these well-known activities, this natural polyphenolic compound also exerts its beneficial effects by modulating different signalling molecules including transcription factors, chemokines, cytokines, tumour suppressor genes, adhesion molecules, microRNAs, etc. Oxidative stress and inflammation play a pivotal role in various diseases like diabetes, cancer, arthritis, Alzheimer's disease and cardiovascular diseases. Curcumin, therefore, could be a therapeutic option for the treatment of these diseases, provided limitations in its oral bioavailability can be overcome. The current review provides an updated overview of the metabolism and mechanism of action of curcumin in various organ pathophysiologies. The review also discusses the potential for multifunctional therapeutic application of curcumin and its recent progress in clinical biology.

Food Chem Toxicol. 2015 Jun 9 ;83:111-124. Epub 2015 Jun 9. PMID: 26066364


Olive metabolites appear to act as topoisomerase II poisons in complex formulations intended for human dietary consumption.

Several naturally occurring dietary polyphenols with chemopreventive or anticancer properties are topoisomerase II poisons. In order to identify additional phytochemicals that enhance topoisomerase II-mediated DNA cleavage, a library of 341 Mediterranean plant extracts was screened for activity against human topoisomerase IIα. An extract from Phillyrea latifolia L., a member of the olive tree family, displayed high activity against the human enzyme. Based on previous metabolomics studies, we identified several polyphenols (hydroxytyrosol, oleuropein, verbascoside, tyrosol, and caffeic acid) as potential candidates fortopoisomerase II poisons. Of these, hydroxytyrosol, oleuropein, and verbascoside enhanced topoisomerase II-mediated DNA cleavage. The potency of these olive metabolites increased 10- to 100-fold in the presence of an oxidant. Hydroxytyrosol, oleuropein, and verbascoside displayed hallmark characteristics of covalent topoisomerase II poisons: 1) the activity of the metabolites was abrogated by a reducing agent, 2) compounds inhibited topoisomerase II activity when incubated with the enzyme prior to the addition of DNA, and 3) compounds were unable to poison a topoisomerase IIα construct thatlacked the N-terminal domain. Because hydroxytyrosol, oleuropein, and verbascoside are broadly distributed across the olive family, extracts from the leaves, bark, and fruit of 11 olive tree species were tested for activity against human topoisomerase IIα. Several of the extracts enhanced enzyme-mediated DNA cleavage. Finally, a commercial olive leaf supplement and extra virgin olive oils pressed from a variety of Olea europea subspecies enhanced DNA cleavage mediated by topoisomerase IIα. Thus, olive metabolites appear to act as topoisomerase II poisons in complex formulations intended forhuman dietary consumption.

Biochemistry. 2015 Jul 1. Epub 2015 Jul 1. PMID: 26132160


This review summarizes the epigenetic events associated with breast cancer and the potential of dietary polyphenols to modulate these events.

Aberrant epigenetic alterations in the genome such as DNA methylation and chromatin remodeling play a significant role in breast cancer development. Since epigenetic alterations are considered to be more easily reversible compared to genetic changes, epigenetic therapy is potentially very useful in reversing some of these defects. Methylation of CpG islands is an important component of the epigenetic code, and a number of genes become abnormally methylated in breast cancer patients. Currently, several epigenetic-based synthetic drugs that can reduce DNA hypermethylation and histone deacetylation are undergoing preclinical and clinical trials. However, these chemicals are generally very toxic and do not have gene specificity. Epidemiological studies have shown that Asian women are less prone to breast cancer due to their high consumption of soy food than the Caucasian women of western countries. Moreover, complementary/and or alternative medicines are commonly used by Asian populations which are rich in bioactive ingredients known to be chemopreventive against tumorigenesis in general. Examples of such agents include dietary polyphenols, (-)-epigallocatechin-3-gallate (EGCG) from green tea, genistein from soybean, isothiocyanates from plant foods, curcumin from turmeric, resveratrol from grapes, and sulforaphane from cruciferous vegetables. These bioactive components are able to modulate epigenetic events, and their epigenetic targets are known to be associated with breast cancer prevention and therapy. This approach could facilitate the discovery and development of novel drugs for the treatment of breast cancer. In this brief review, we will summarize the epigenetic events associated with breast cancer and the potential of some of these bioactive dietary components to modulate these events and thus afford new therapeutic or preventive approaches.

Chem Res Toxicol. 2012 Jan 13 ;25(1):61-73. Epub 2011 Oct 28. PMID: 21992498


Hibiscus sabdariffa leaf extract could increase the expressions of autophagy-related proteins autophagy-related genes and induce autophagic cell death in A375 cells.

Melanoma is the least common but most fatal form of skin cancer. Previous studies have indicated that an aqueous extract of Hibiscus sabdariffa leaves possess hypoglycemic, hypolipidemic, and antioxidant effects. In this study, we want to investigate the anticancer activity of Hibiscus leaf polyphenolic (HLP) extract in melanoma cells. First, HLP was exhibited to be rich in epicatechin gallate (ECG) and other polyphenols. Apoptotic and autophagic activities of HLP and ECG were further evaluated by DAPI stain, cell-cycle analysis, and acidic vascular organelle (AVO) stain. Our results revealed that both HLP and ECG induced the caspases cleavages, Bcl-2 family proteins regulation, and Fas/FasL activation in A375 cells. In addition, we also revealed that the cells presented AVO-positive after HLP treatments. HLP could increase the expressions of autophagy-related proteins autophagy-related gene 5 (ATG5), Beclin1, and light chain 3-II (LC3-II), and induce autophagic cell death in A375 cells. These data indicated that the anticancer effect of HLP, partly contributed by ECG, in A375 cells. HLP potentially could be developed as an antimelanoma agent.

J Food Sci. 2015 Mar ;80(3):H649-58. Epub 2015 Feb 17. PMID: 25694272


Pluronic F68-curcumin conjugate micelles are promising to improve the clinical effectiveness of CUR in cancer treatment.

Curcumin (CUR), a nontoxic polyphenol derived from the rhizome of turmeric (Curcuma longa), has been recognized as an anti-cancer and chemo-preventative agent. However, its clinical application for cancer treatment has been greatly limited due to its poor water-solubility and low bioavailability. To tackle this problem, Pluronic F68-CUR (F68-CUR) conjugate micelles, which are amphiphilic copolymers, were designed and synthesized in this study. These highly stable micelles with CUR concentrated in the core were formulated using the solvent evaporation method and were confirmed by Fourier transform infrared spectroscopy and nuclear magnetic resonance. Physicochemical characterization of F68-CUR conjugate micelles revealed that high drug loading content (DL%; 0.248 mg CUR/1 mg F68) was achieved, and the average particle size of micelles was 115.2 ± 3.0 nm. Compared with free CUR, a significantly higher cytotoxicity against human breast cancer cell line MDA-MB-231 was observed in F68-CUR conjugate micelles. The IC50 value of F68-CUR conjugate micelles was 1.95-fold lower than that of free CUR, indicating that the anti-cancer activity of CUR was significantly improved in the micelles. Furthermore, apoptotic studies demonstrated that F68-CUR conjugate micelles induced more cell apoptosis than that of free CUR. Taken together, these results demonstrate that F68-CUR conjugate micelles are promising to improve the clinical effectiveness of CUR in cancer treatment.

Drug Deliv. 2015 Jun 12:1-9. Epub 2015 Jun 12. PMID: 26066393


Curcumin is able to inhibit directly the enzymatic activity of the EGFR intracellular domain.

Epidermal Growth Factor Receptor (EGFR) is an important target of anticancer therapy. Nowadays, the search for new molecules inhibiting this receptor is turning toward natural substances. One of the most promising natural compounds that have shown an anti-EGFR activity is curcumin, a polyphenol found in turmeric. Its effect on the receptor kinase activity and on the receptor autophosphorylation has been already described, but the mechanism of how curcumin interacts with EGFR is not fully elucidated. We demonstrate that the mode of action of curcumin is dual. This polyphenol is able to inhibit directly but partially the enzymatic activity of the EGFR intracellular domain. The present work shows that curcumin also influences the cell membrane environment of EGFR. Using biomimetic membrane models, we show that curcumin insertion into the lipid bilayer leads to its rigidification. Single particle tracking analyses performed in the membrane of A431 cancer cells confirmed that this effect of curcumin on the membrane slows down the receptor diffusion. This is likely to affect the receptor dimerization and, in turn, its activation.

Biomacromolecules. 2015 May 11 ;16(5):1634-42. Epub 2015 Apr 24. PMID: 25893361


EGCG induced cell death via the cGMP/ASM pathway in chronic myeloid leukemia cells.

An epidemiological study showed that green tea consumption is associated with a reduced risk of hematopoietic malignancy. The major green tea polyphenol epigallocatechin‑3-O-gallate (EGCG) is reported to have anticancer effects. Chronic myeloid leukemia (CML) is a major hematopoietic malignancy characterized by expansion of myeloid cells. In the present study, we showed EGCG-induced acid sphingomyelinase (ASM) activation and lipid raft clustering in CML cells. The ASM inhibitor desipramine significantly reduced EGCG-induced cell death. Protein kinase Cδ is a well‑known kinase that plays an important role in ASM activation. We observed EGCG-induced phosphorylation of protein kinase Cδ at Ser664. Importantly, EGCG-induced ASM activation was significantly reduced by pretreatment of CML cells with the soluble guanylate cyclase inhibitor NS2028, suggesting that EGCG induced ASM activation through the cyclic guanosine monophosphate (cGMP)-dependent pathway. Indeed, pharmacological inhibition of a cGMP-negative regulator enhanced the anti-CML effect ofEGCG. These results indicate that EGCG-induced cell death via the cGMP/ASM pathway in CML cells.

Oncol Rep. 2015 Jun 26. Epub 2015 Jun 26. PMID: 26135316


This article focuses on advances in the effects of curcumin and its derivatives for treatment of liver injury, non-alcoholic fatty liver disease, liver fibrosis and hepatocarcinoma.

Curcumin is a principal polyphenolic curcuminoid extracted from turmeric rhizome, which has been used for treating inflammation of joints, ulcers, jaundice and other disorders in Asian traditional medicine. In recent years, many studies have indicated that curcumin plays important roles in treatment of liver diseases. Curcumin attenuates liver injury and non-alcoholic fatty liver disease by lowering the release of inflammation cytokines, minimizing oxidative stress, enhancing the sensitivity of insulin and altering lipid metabolism. Curcumin shows potent anti-fibrosis activity, contributing to inhibit the activation of hepatic stellate cells and reduce the deposition of extracellular matrix by its regulation of PPAR-γ, NF-ΚB and TGF-β signaling pathways. Moreover, curcumin exhibits anti-cancer effect by inducing G2/M phase cell cycle arrest and apoptosis in several hepatoma cell lines. However, poor water solubility and low bioavailability of curcumin limit its clinical applications. To overcome its limitedsystemic bioavailability, many new approaches have been explored to deliver curcumin effectively. This article focuses on advances in the effects of curcumin and its derivatives for treatment of liver injury, non-alcoholic fatty liver disease, liver fibrosis and hepatocarcinoma.

Yao Xue Xue Bao. 2014 Nov ;49(11):1483-90. PMID: 25757271


Resveratrol was able to inhibit the hedgehog signaling pathway and EMT, and suppress invasion and metastasis in gastric cancer in vitro.

The hedgehog (Hh) signaling pathway is vital to vertebrate development, the homeostatic process and tumorigenesis. Epithelial-mesenchymal transition (EMT) is a cellular process during which epithelial cells become mesenchymal-appearing cells, which in turn promotes cancer metastasis and invasion. Resveratrol is a natural polyphenolic compound found in grapes, a variety of berries, peanuts and other plants. Numerous studies have demonstrated that the Hh signaling pathway is able to regulate the EMT, and that resveratrol can suppress carcinoma invasion and metastasis. In addition, certain studies have indicated that resveratrol can inhibit the Hh signaling pathway and EMT in cancers other than gastric cancer. The purpose of the present study was to investigate the inhibitory effect of resveratrol on the Hh signaling pathway and EMT in gastric cancer in vitro. Gastric cancer SGC-7901 cells were treated with resveratrol or cyclopamine at different concentrations. The viability of the cells was assessed using an MTT assay. The expression of Gli-1, a key component of the Hh signaling pathway, and Snail, E-cadherin and N-cadherin, key components of EMT, was detected by reverse transcription polymerase chain reaction (RT-PCR) and western blotting. The invasion and metastasis of the cells were observed by performing a cell scratch test. The RT-PCR and western blotting showed a decrease in Gli-1, Snail and N-cadherin expression, and an increase in E-cadherin expression in the resveratrol and cyclopamine group compared with the control group, suggesting that resveratrol inhibited the Hh pathway and EMT, as did cyclopamine. The MTT assay indicated that the viability of the SGC-7901 cells was significantly decreased in a concentration-dependent manner following resveratrol and cyclopamine treatment. The cell scratch test showed slower cell invasion and metastasis in the resveratrol and cyclopamine groups. These findings indicated that resveratrol was able to inhibit the Hh signaling pathway and EMT, and suppress invasion and metastasis in gastric cancer in vitro.

Oncol Lett. 2015 May ;9(5):2381-2387. Epub 2015 Feb 26. PMID: 26137075


A review of recent applications of curcumin as anti-invasive and antimetastatic agent in in vitro and in vivo and ex vivo studies as well as associated molecular mechanisms.

A huge number of compounds are widely distributed in nature and many of these possess medicinal/biological/pharmacological activity. Curcumin, a polyphenol derived from the rhizomes (underground stems) of Curcuma longa Linn (a member of the ginger family, commonly known as turmeric) is a culinary spice and therapeutic used in India for thousands of years to induce color and flavor in food as well as to treat a wide array of diseases. The origin of turmeric as spice and folklore medicine is so old that it is lost in legend. Curcumin has many beneficial pharmacological effects which includes, but are not limited with, antimicrobial, anti-inflammatory, antioxidant, antiviral, antiangiogenic, neurodegenerative diseases such as Alzheimer disease, and antidiabetic activities. Most importantly curcumin possesses immense antitumorigenic effect. It prevents tumor invasion and metastasis in a number of animal models, including models of lung, liver, stomach, colon, breast, esophageal cancer etc. Invasion and metastasis are considered as one of the hallmarks in cancer biology. The pertinent recent applications of curcumin as anti-invasive and antimetastatic agent in in vitro and in vivo and ex vivo studies as well as associated molecular mechanisms have been discussed in this review. Curcumin has also demonstrated the ability to improve patient outcomes in clinical trials.

Front Chem. 2014 ;2:113. Epub 2014 Dec 23. PMID: 25566531


Curcumin significantly decreased the LPS-induced pro-inflammatory mediators NO, PGE2, and IL-6 by inhibiting the activation of NF-κB.

Inflammation and the presence of pro-inflammatory cytokines are associated with numerous chronic diseases such as type-2 diabetes mellitus, cardiovascular disease, Alzheimer's disease, and cancer. An overwhelming amount of data indicates that curcumin, a polyphenol obtained from the Indian spice turmeric, Curcuma longa, is a potential chemopreventive agent for treating certain cancers and other chronic inflammatory diseases. However, the low bioavailability of curcumin, partly due to its low solubility and stability in the digestive tract, limits its therapeutic applications. Recent studies have demonstrated increased bioavailability and health-promoting effects of a novel solid lipid particle formulation of curcumin (Curcumin SLCP, Longvida(®)). The goal of this study was to evaluate the aqueous solubility and in vitro anti-inflammatory effects of solid lipid curcumin particle (SLCP) formulations using lipopolysaccharide (LPS)-stimulated RAW 264.7 cultured murine macrophages. SLCPs treatment significantly decreased nitric oxide (NO) and prostaglandin-E2 (PGE2) levels at concentrations ranging from 10 to 50 μg/mL, and reduced interleukin-6 (IL-6) levels in a concentration-dependent manner. Transient transfection experiments using a nuclear factor-kappa B (NF-κB) reporter construct indicate that SLCPs significantly inhibit the transcriptional activity of NF-κB in macrophages. Taken together, these results show that in RAW 264.7 murine macrophages, SLCPs have improved solubility over unformulated curcumin, and significantly decrease the LPS-induced pro-inflammatory mediators NO, PGE2, and IL-6 by inhibiting the activationof NF-κB.

J Med Food. 2015 Jul ;18(7):786-92. Epub 2014 Dec 9. PMID: 25490740


This review addresses certain aspects of NF-κB-related inflammatory response, its role in carcinogenesis and therapy benefits that may be gained through silencing NF-κB.

The mechanisms of beneficial preventive and therapeutic effects achieved by traditional and complementary medicine are currently being deciphered in molecular medicine. Curcumin, a yellow-colored polyphenol derived from the rhizome of turmeric (Curcuma longa), influences a wide variety of cellular processes through the reshaping of many molecular targets. One of them, nuclear factor kappa B (NF-κB), represents a strong mediator of inflammation and, in a majority of systems, supports the pro-proliferative features of cancer cells. The application of various anticancer drugs, cytostatics, triggers signals which lead to an increase in cellular NF-κB activity. As a consequence, cancer cellsoften reshape their survival signaling pathways and, over time, become resistant to applied therapy. Curcumin was shown to be a strong inhibitor of NF-κB activity and its inhibitory effect on NF-κB related pathways often leads to cellular apoptotic response. All these facts, tested and confirmed in many different biological systems, have paved the way for research aimed to elucidate the potential beneficial effects of combining curcumin and various anti-cancer drugs in order to establish more efficient and less toxic cancer treatment modalities. This review addresses certain aspects of NF-κB-related inflammatory response, its role in carcinogenesis and therapy benefits that may be gained through silencing NF-κB by selectively combining curcumin and various anticancer drugs.

Curr Pharm Des. 2014 ;20(42):6682-96. PMID: 25341940


Ursolic acid could synergize with ionizing radiation against human gastric cancer cell lines.

Recent research has suggested that certain plant-derived polyphenols, i.e., ursolic acid (UA), which are reported to have antitumor activities, might be used to sensitize tumor cells to radiation therapy by inhibiting pathways leading to radiation therapy resistance. This experiment was designed to investigate the effects and possible mechanism of radiosensitization by UA in BGC-823 cell line from human adenocarcinoma gastric cancer in vitro. UA caused cytotoxicity in a dose-dependent manner, and we used a sub-cytotoxicity concentration of UA to test radioenhancement efficacy with UA in gastric cancer. Radiosensitivity was determined by clonogenic survival assay. Surviving fraction of the combined group with irradiation and sub-cytotoxicity UA significantly decreased compared with the irradiation group. The improved radiosensitization efficacy was associated with enhanced G2/M arrest, increased reactive oxygen species (ROS), down-regulated Ki-67 level and improved apoptosis. In conclusion, as UA demonstrated potent antiproliferation effect and synergistic effect, it could be used as a potential drug sensitizer for the application of radiotherapy.

PLoS One. 2015;10(7):e0133169. Epub 2015 Jul 15. PMID: 26177078


A brief overview of the evidence supporting anticancer activity of indian gooseberry extracts and suggests possible mechanisms for these actions.

There is a wealth of information emanating from both in vitro and in vivo studies indicating fruit extract of the Phyllanthus emblica tree, commonly referred to as Indian Gooseberries, has potent anticancer properties. The bioactivity in this extract is thought to be principally mediated by polyphenols, especially tannins and flavonoids. It remains unclear how polyphenols from Phyllanthus emblica can incorporate both cancer-preventative and antitumor properties. The antioxidant function of Phyllanthus emblica can account for some of the anticancer activity, but clearly other mechanisms are equally important. Herein, we provide a brief overview of the evidence supporting anticancer activity of Indian Gooseberry extracts, suggest possible mechanisms for these actions, and provide future directions that might be taken to translate these findings clinically.

Oxid Med Cell Longev. 2015;2015:950890. Epub 2015 Jun 9. PMID: 26180601


Combining lower concentrations of EGCG and theaflavin results in greater cell death compared to either extract alone at the same concentration.

There is considerable interest in the potential of botanicals in preventing and/or alleviating chronic ailments. Among the most studied botanicals are compounds present in green and black teas. Nontoxic tea polyphenols are potent antioxidants, and they also modulate several signalling pathways and inhibit proteins such as MMP-9 or protein plasminogen activator system, making them very attractive potential therapeutics. One criticism of the prophylactic or therapeutic use of green or black tea polyphenols was presumably the poor bioavailability of these chemicals when ingested. However, studies have shown that epigallocatechin-3-gallate (EGCG) and theaflavin (TF) can be detected in the small and large intestine, liver, and prostate of experimental animals after consumption of tea extracts. In particular, a study was carried out on 20 men scheduled for prostatectomy, who were assigned to consume teas for five days before surgery. Tea polyphenols were detected in the prostate. This fact contradicts the common misconception of poor bioavailability of TF and EGCG and makes feasible the application of green or black tea polyphenols as prophylactic and therapeutic agents. Theaflavins and catechins seem to act on cancer cells largely through different pathways, so utilisation of both could offer synergistic anticancer effects, but so far no work has been done on the cumulative effects of EGCG and TF on prostate cancer. Therefore, in this study we have investigated if EGCG in combination with TF can reduce the rate of prostate cancer growth, and we have observed greater cell death compared to application of either TF or EGCG alone.

Cent Eur J Immunol. 2015 ;40(1):1-4. Epub 2015 Apr 22. PMID: 26155176


Artichoke polyphenols could be a promising dietary tool either in cancer chemoprevention or/and in cancer treatment as a nonconventional, adjuvant therapy.

Polyphenolic extracts from the edible part of artichoke (Cynara scolymus L.) have been shown to be potential chemopreventive and anticancer dietary compounds. High doses of polyphenolic extracts (AEs) induce apoptosis and decrease the invasive potential of the human breast cancer cell line, MDA-MB231. However, the molecular mechanism underlying AEs antiproliferative effects is not completely understood. We demonstrate that chronic and low doses of AEs treatment at sublethal concentrations suppress human breast cancer cell growth via a caspases-independent mechanism. Furthermore, AEs exposure induces a significant increase of senescence-associatedβ-galactosidase (SA-β-gal) staining and upregulation of tumour suppressor genes, p16(INK4a) and p21(Cip1/Waf1) in MDA-MB231 cells. AEs treatment leads to epigenetic alterations in cancer cells, modulating DNA hypomethylation and lysine acetylation levels in total proteins. Cell growth arrest correlates with increased reactive oxygen species (ROS) production in AEs treated breast cancer cells. Inhibition of ROS generation by N-acetylcysteine (NAC) attenuates the antiproliferative effect. These findings demonstrate that chronic AEs treatment inhibits breast cancer cell growth via the inductionof premature senescence through epigenetic and ROS-mediated mechanisms. Our results suggest that artichoke polyphenols could be a promising dietary tool either in cancer chemoprevention or/and in cancer treatment as a nonconventional, adjuvant therapy.

Oxid Med Cell Longev. 2015;2015:363827. Epub 2015 Jun 9. PMID: 26180585


This study demonstrates a novel role for natural occurring polyphenols as PDE inhibitors that enhance pancreatic β-cell function.

Resveratrol (RES) and curcumin (CUR) are polyphenols that are found in fruits and turmeric, and possess medicinal properties that are beneficial in various diseases, such as heart disease, cancer, and type 2 diabetes mellitus (T2DM). Results from recent studies have indicated that their therapeutic properties can be attributed to their anti-inflammatory effects. Owing to reports stating that they protect againstβ-cell dysfunction, we studied their mechanism(s) of action in β-cells. In T2DM, cAMP plays a critical role in glucose- and incretin-stimulated insulin secretion as well as overall pancreatic β-cell health. A potential therapeutic target in the management of T2DM lies in regulating the activity of phosphodiesterases (PDEs), which degrade cAMP. Both RES and CUR have been reported to act as PDE inhibitors in various cell types, but it remains unknown if they do so in pancreatic β-cells. In our current study, we found that both RES (0.1-10 μmol/l) and CUR (1-100 pmol/l)-regulated insulinsecretion under glucose-stimulated conditions. Additionally, treating β-cell lines and human islets with these polyphenols led to increased intracellular cAMP levels in a manner similar to 3-isobutyl-1-methylxanthine, a classic PDE inhibitor. When we investigated the effects of RES and CUR on PDEs, we found that treatment significantly downregulated the mRNA expression of most of the 11 PDE isozymes, including PDE3B, PDE8A, and PDE10A, which have been linked previously to regulation of insulin secretion in islets. Furthermore, RES and CUR inhibited PDE activity in a dose-dependent manner inβ-cell lines and human islets. Collectively, we demonstrate a novel role for natural-occurring polyphenols as PDE inhibitors that enhance pancreatic β-cell function.

J Endocrinol. 2014 Nov ;223(2):107-17. PMID: 25297556


Curcumin in combination with retinoic acid sensitizes RA-resistant TNBC cells by suppressing FABP5/PPARβ/δ pathway, and promotes the growth inhibitory effect of RA.

BACKGROUND: A major obstacle in the use of retinoid therapy in cancer is the resistance to this agent in tumors. Retinoic acid facilitates the growth of mammary carcinoma cells which express high levels of fatty acid-binding protein 5 (FABP5). This protein delivers retinoic acid to peroxisome proliferator-activated receptorβ/δ (PPARβ/δ) that targets genes involved in cell proliferation and survival. One approach to overcome resistance of mammary carcinoma cells to retinoic acid is to target and suppress the FABP5/ PPARβ/δ pathway. The objective of this research was to investigate the effect of curcumin, a polyphenol extract from the plant Curcuma longa, on the FABP5/ PPARβ/δ pathway in retinoic acid resistant triple negative breast cancer cells.METHODS: Cell viability and proliferation of triple negative breast cancer cell lines (MDA-MB-231 and MD-MB-468) treated with curcumin and/or retinoic was analyzed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and 5-bromo-2'-deoxyuridine (BrdU). Expression level of FABP5 and PPARβ/δ in these cells treated with curcumin was examined by Western Blotting analysis and Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR). Effect of curcumin and retinoic acid on PPARβ/δ target genes, PDK1and VEGF-A were also examined using qRT-PCR. Western Blotting was utilized to examine the protein expression level of the p65 subunit of NF-κB.RESULTS: Treatment of retinoic acid resistant triple negative breast cancer cells with curcumin sensitized these cells to retinoic acid mediated growth suppression, as well as suppressed incorporation of BrdU. Further studies demonstrated that curcumin showed a marked reduction in the expression level of FABP5 and PPARβ/δ. We provide evidence that curcumin suppresses p65, a transcription factor known to regulate FABP5. The combination of curcumin with retinoic acid suppressed PPARβ/δ target genes, VEGF-A and PDK1.CONCLUSIONS: Curcumin suppresses the expression level of FABP5 and PPARβ/δ in triple negative mammary carcinoma cells. By targeting the FABP5/PPARβ/δ pathway, curcumin prevents the delivery of retinoic acid to PPARβ/δ and suppresses retinoic acid-induced PPARβ/δ target gene, VEGF-A. Our data demonstrates that suppression of the FABP5/ PPARβ/δ pathway by curcumin sensitizes retinoic acid resistant triple negative breast cancer cells to retinoic acid mediated growth suppression.

BMC Cancer. 2014 ;14:724. Epub 2014 Sep 27. PMID: 25260874


Low dose Resveratrol and Curcumin enhances the Centchroman action through ROS mediated JNK/p38 as well as mitochondrial pathway in MCF-7 cells.

Polyphenols as"sensitizers"together with cytotoxic drugs as"inducers"cooperate to trigger apoptosis in various cancer cells. Hence, their combination having similar mode of mechanism may be a novel approach to enhance the efficacy of inducers. Additionally, this will also enable to achieve the physiological concentrations facilitating significant increase in the activity at concentrations which the compound can individually provide. Here we propose that polyphenols (Resveratrol (RES) and Curcumin (CUR)) pre-treatment may sensitize MCF-7/MDA MB-231 (Human Breast Cancer Cells, HBCCs) to Centchroman (CC, antineoplastic agent). 6 h pre-treated cells with 10µM RES/CUR and 100 µM RES/30 µM CUR doses, followed by 10 µM CC for 18 h were investigated for Ser-167 ER-phosphorylation, cell cycle arrest, redox homeostasis, stress activated protein kinase (SAPKs: JNK and p38 MAPK) pathways and downstream apoptosis effectors. Low dose RES/CUR enhances the CCaction through ROS mediated JNK/p38 as well as mitochondrial pathway in MCF-7 cells. However, RES/CUR sensitization enhanced apoptosis in p53 mutant MDA MB-231 cells without/with involvement of ROS mediated JNK/p38 adjunct to Caspase-9. Contrarily, through high dose sensitization in CC treated cells, the parameters remained unaltered as in polyphenols alone. We conclude that differential sensitization of HBCCs with low dose polyphenol augments apoptotic efficacy of CC. This may offer a novel approach to achieve enhanced action of CC with concomitant reduction of side effects enabling improvedmanagement of hormone-dependent breast cancer.

PLoS One. 2012 ;7(6):e37736. Epub 2012 Jun 29. PMID: 22768036


These results indicate a potential role of urolithin A as a chemopreventive agent for prostate cancer.

PURPOSE: Walnuts contain several bioactive compounds, including pedunculagin, a polyphenol metabolized by microbiota to form urolithins, namely urolithin A (UA). The aim of this study was to determine gene expression changes in prostate cancer cells after incubation with UA.METHODS: We performed a genomic analysis to study the effect of UA on LNCaP prostate cells. Cells were incubated with 40 µM UA for 24 h, and RNA was extracted and hybridized to Affymetrix Human Genome U219 array. Microarray results were analyzed using GeneSpring v13 software. Differentially expressed genes (p  2) were used to perform biological association networks. Cell cycle was analyzed by flow cytometry and apoptosis measured by the rhodamine method and by caspases 3 and 7 activation. Cell viability was determined by MTT assay.RESULTS: We identified two nodes, FN-1 and CDKN1A, among the differentially expressed genes upon UA treatment. CDKN1A was validated, its mRNA and protein levels were significantly up-regulated, and the promoter activation measured by luciferase. Cell cycle analysis showed an increase in G1-phase, and we also observed an induction of apoptosis and caspases 3 and 7 activation upon UA treatment.CONCLUSION: Our results indicate a potential role of UA as a chemopreventive agent for prostate cancer.

Eur J Nutr. 2015 May 12. Epub 2015 May 12. PMID: 25962506


Resveratrol protects H9c2 cells against DOX induced ER stress through ER stabilization, and more specifically through the activation of the Sirt1 pathway, thereby leading to cardiac cell survival.

Treatment with doxorubicin (DOX) is one of the major causes of chemotherapy-induced cardiotoxicity and is therefore, the principal limiting factor in the effectiveness of chemotherapy for cancer patients. DOX‑induced heart failure is thought to result from endoplasmic reticulum (ER) stress and cardiomyocyte apoptosis. Resveratrol (RV), a polyphenol antioxidant found in red wine, has been shown to play a cardioprotective role. The aim of the present study was to examine the effects of RV on DOX‑induced cardiotoxicity in H9c2 cells. We hypothesized that RV would protect H9c2 cells against DOX‑induced ER stress and subsequent cell death through the activation of the Sirt1 pathway. Our results demonstrated that the decrease observed in the viability of the H9c2 cells following exposure to DOX was accompanied by a significant increase in the expression of the ER stress‑related proteins, glucose‑regulatedprotein 78 (GRP78) and C/EBP homologous protein (CHOP). However, we found that RV downregulated the expression of ER stress marker protein in the presence of DOX and restored the viability of the H9c2 cells. Exposure to RV or DOX alone only slightly increased the protein expression of Sirt1, whereas a significant increase in Sirt1 protein levels was observed in the cells treated with both RV and DOX. The Sirt1 inhibitor, nicotinamide (NIC), partially neutralized the effects of RV on the expression of Sirt1 in the DOX‑treated cells and completely abolished the effects of RV on the expression of GRP78 and CHOP. The findings of our study suggest that RV protects H9c2 cells against DOX‑induced ER stress through ER stabilization, and more specifically through the activation of the Sirt1 pathway, thereby leading to cardiac cell survival.

Int J Mol Med. 2015 Jul 20. Epub 2015 Jul 20. PMID: 26202177


Noni extracts strongly inhibited the proliferation and increased apoptosis in MCF-7 and MDA-MB-231 cells.

Morinda citrifolia L. (NONI) fruits have been used for thousands of years for the treatment of many health problems including cancer, cold, diabetes, flu, hypertension, and pain. Plant extracts have reported several therapeutic benefits, but extraction of individual compound from the extract often exhibits limited clinical utility as the synergistic effect of various natural ingredients gets lost. They generally constitute polyphenols and flavonoids. Studies have suggested that these phytochemicals, especially polyphenols, display high antioxidant properties, which help to reduce the risk of degenerative diseases, such as cancer and cardiovascular diseases. Several in-vitro and in-vivo studies have shown that Noni fruits have antioxidant, anti-inflammatory, anti-dementia, liver-protective, anticancer, analgesic, and immunomodulatory effects. Till date about 7 in vitro cancer studies have been done, but a detailed in vitro study including cell cycle and caspase activation assay on breast cancer cell line has not been done. In the present study different Noni fruit fractions have tested on cancer cell lines MCF-7, MDA-MB-231 (breast adenocarcinoma) and one non-cancer cell line HEK-293 (Human embryonic kidney). Out of which ethylacetate extract showed a higher order of in vitro anticancer activity profile. The ethylacetate extract strongly inhibited the proliferation of MCF-7, MDA-MB-231 and HEK-293 cell lines with IC50 values of 25, 35, 60 µg/ml respectively. The extract showed increase in apoptotic cells in MCF-7 and MDA-MB-231 cells and arrested the cell cycle in the G1/S phase in MCF-7 and G0/G1 phase in MDA-MB-231 cells. Noni extract also decreases the intracellular ROS generation and mitochondrial membrane potential.

Drug Res (Stuttg). 2015 Jul 9. Epub 2015 Jul 9. PMID: 26158795


These results demonstrate that enhanced expression of miR-126 increased the sensitivity of osteosarcoma cells to EGCG through induction of apoptosis.

BACKGROUND: miR-126 plays an important role in the proliferation, invasion, migration, and chemotherapeutics resistance in cancer. Epigallocatechin-3-gallate (EGCG), as the major polyphenolic constituent present in green tea, is a promising anticancer agent. However, the role of miR-126 in EGCG anticancer remains unclear. Here, we investigated the effects of miR-126 and EGCG on cell viability, apoptosis, cell cycle distribution of osteosarcoma cells and the sensitization of miR-126 on osteosarcoma cells to EGCG.METHODS: The cell viability, apoptosis and cycle distribution were analyzed using MTT assay and flow cytometry.RESULTS: Our results showed that EGCG (0.025, 0.05, 0.1, 0.2 g/L) suppresses proliferation of osteosarcoma MG63 and U2OS cells in a concentration-dependent and time-dependent manner and the inhibitory effects of 0.05 g/L EGCG on U2OS cells were roughly equivalent to 20 μM cisplatin (DDP); miR-126 could promote apoptosis and inhibit proliferation in U2OScells but without significant effects on cell cycle G1 phase arrest; EGCG suppressed proliferation of U2OS cells through induction of cell cycle G1 arrest and apoptotic death; overexpression of miR-126 enhanced the inhibitory effects of EGCG on proliferation in U2OS cells via promotion of apoptosis.CONCLUSIONS: Our results demonstrate that enhanced expression of miR-126 increased the sensitivity of osteosarcoma cells to EGCG through induction of apoptosis.

World J Surg Oncol. 2014 ;12:383. Epub 2014 Dec 16. PMID: 25510179


An açai polyphenolic extract had antiinflammatory and cytotoxic activities in colon cancer cells and can be effective as natural colon cancer chemopreventive agent.

This study aimed to evaluate the cell growth inhibition activity of açai (Euterpe oleracea Mart.) polyphenolic extract against colon cancer HT-29 and SW-480 cells and the nonmalignant CCD-18Co colon fibroblast cells. Results showed that açai polyphenolic extract (5-20 mg/L) inhibited preferentially the growth of SW-480 cells with no toxicity in CCD-18Co cells, andthis was accompanied by reduction of H2O2-induced reactive oxygen species (ROS) generation. The mechanisms involved in SW-480 cell growth-inhibition by açai polyphenolic extract included the downregulation of NF-κB proinflammatory transcription factor and the nuclear factor-kappa B targets intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). Furthermore, prooncogenic specificity proteins (Sp) were downregulated as well as Sp-targets Bcl-2, vascular endothelial growth factor, and survivin. This was accompanied by activation of mitochondrial proapoptotic pathway involving increase of cytochrome c, cleavage of caspase-3, and decrease of PARP-1. Results strongly suggest that açai polyphenolic extract has antiinflammatory and cytotoxic activities in colon cancer cells and can be effective as natural colon cancer chemopreventive agents.

Nutr Cancer. 2014 ;66(8):1394-405. Epub 2014 Oct 20. PMID: 25329001


Curcumin inhibits cell proliferation and promotes apoptosis in osteoclastoma cell through suppression of MMP-9 and NF-κB, and activation JNK signaling pathways.

Curcumin is a polyphenol compound extracted from ginger plant, turmeric, commonly used in a variety of food coloring and flavoring additives. Curcumin has many effects such as anti-inflammatory, anti-tumor, antioxidant and anti-microbial effects. However, the mechanism underlying the anti-cancer effect of curcumin on human osteoclastoma (Giant cell tumor, GCT) cells remains unclear. The objectives of this study were to determine the efficacy of curcumin on proliferation and apoptosis of GCT cells and its related mechanisms. In our study, cell viability, cellular apoptosis and caspase-3 activity of GCT cells were analyzed using 3.3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry (FCM) assay and commercial kits, respectively. Next, MMP-9 gene expression quantity, NF-κB activity and JNK protein expression of GCT cells were tested with real-time polymerase chain reaction (RT-PCR), commercial kits and western blotting assay, respectively. Firstly, MMP-9, NF-κB and JNK inhibitors were added into GCT cells and which was researched the mechanism of curcumin on human GCT cells. In this study, the efficacy of curcumin reduced cell viability, induced cellular apoptosis and increased caspase-3 activity of GCT cells. Furthermore, curcumin inhibited the MMP-9 gene expression quantity and NF-κB activity, and activated JNK protein expression in GCT cells. Meanwhile,down-regulation of MMP-9 gene expression quantity and NF-κB activity could promote the anti-cancer effect of curcumin on cell viability of GCT cells. Interesting, down-regulation of JNK protein expression could also reversed the anti-cancer effect of curcumin on cell viability of GCT cells. Takentogether, our results suggest that curcumin inhibits cell proliferation and promotes apoptosis in osteoclastoma cell through suppression of MMP-9 and NF-κB, and activation JNK signaling pathways.

Int J Clin Exp Pathol. 2015 ;8(6):6037-45. Epub 2015 Jun 1. PMID: 26261481


This review is focused on the relationship between flavonoids and cancer, with special emphasis on the role of quercetin in anticancer treatment.

Cancer is a problem of global importance; since the incidence is increasing worldwide and therapeutic options are generally limited. Thus, it becomes imperative to find new therapeutic targets as well as new molecules with therapeutic potential for tumors. Flavonoids are polyphenolic compounds that may be potential therapeutic agents. Several studies have shown that these compounds have a higher anticancer potential. Among the flavonoids in the human diet, quercetin is one of the most important. In the last decades, several anticancer properties of quercetin have been described, such as cell signaling, pro-apoptotic, anti-proliferative and anti-oxidant effects, growth suppression. In fact, it is now well known that quercetin has diverse biological effects, inhibiting multiple enzymes involved in cell proliferation, as well as, in signal transduction pathways. On the other hand, there are also studies reporting potential synergistic effects when combined quercetin with chemotherapeutic agents or radiotherapy. In fact, several studies which aim to explore the anticancer potential of these combined treatments have already been published, the majority with promising results. Actually it is well known that quercetin can act on the chemo sensitization and radio sensitization but also as chemo protective and radio protective, protecting normal cells of the side effects that result from chemotherapy and radiotherapy, which obviously provides notable advantages in their use in anticancer treatment. Thus, all these data indicate that quercetin may have a key role in anticancer treatment. In this context, this review is focused on the relationship between flavonoids and cancer, with special emphasis on the role of quercetin.

Curr Med Chem. 2015 Aug 12. Epub 2015 Aug 12. PMID: 26264923

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