Potential of grape polyphenols as breast cancer therapeutics

Introduction Grape and red wine polyphenols have long been purported to have multiple health benefits. Although convincing clinical data are still lacking, recent experimental studies have demonstrated the utility of grape polyphenols as anticancer compounds. This review discusses the potential of the major polyphenols from grape and red wine, resveratrol, quercetin and catechin, as alternative therapeutics for breast cancer. Discussion Accumulated data from in vitro studies with breast cancer cell lines and in vivo studies with rodent models demonstrate a pro-apoptotic, antiproliferative, anti-invasive, anti-angiogenic and anti-metastatic role for grape polyphenols in breast cancer. At the molecular level, the anticancer effects of grape polyphenols have been attributed to the inhibition of a number of cancer-promoting pathways that include oestrogen receptor, growth factor receptor, mitogen-activated protein kinases, phosphoinosite 3-kinase/Akt/mammalian target of rapamycin and nuclear factor κB signalling sequelae. Studies from our group have shown that an equimolar formulation of the major grape polyphenols resveratrol, quercetin and catechin can reduce the growth of breast cancer cells and mammary tumours, as well as metastasis. Moreover, these grape polyphenols have potential as chemosensitisers of anti-growth factor receptor therapy, via inhibition of the phosphoinosite 3-kinase/Akt/mammalian target of rapamycin pathway. Conclusion Appropriate pre-clinical and clinical studies to determine the efficacy, correct dosage and combination of grape polyphenols are warranted before the establishment of guidelines for the treatment of breast cancer patients, those at high-risk and survivors.