Concentration‐dependent effect of (−) epicatechin in hypertensive patients

Non-vitamin polyphenolic compounds are ubiquitous in food plants and therefore potentially present in human plasma in a diet-dependent concentration. The aim of this study was to evaluate the concentration-dependent effect of (-) epicatechin, a polyphenol present in green tea with antioxidant activity, on various biomarkers of oxidative stress. The current study examined the in vitro concentration-dependent (10(-4) M to 10(-7) M) effects of (-) epicatechin on biomarkers of oxidative stress viz. malondialdehyde (MDA), reduced glutathione (GSH), membrane sulfhydryl (-SH) group and protein carbonyl content in hypertensive patients and normal ones. This effect seems to be due to ability of (-) epicatechin to reduce MDA and protein carbonyl content while increase in GSH and membrane -SH group in hypertensive patients. It can be concluded that (-) epicatechin exerts an antioxidant action inside the cell, responsible for the observed modulation of cellular response to oxidative challenges.