['There is substantial evidence that a diet rich in fruit and vegetables may reduce the risk of aging and stress oxidative associated diseases. It has been suggested that benefits associated with fruit and red wine consumption could be due to pooled antioxidant microcomponents in diet. The aim of this study was to investigate the antioxidant activities of pure resveratrol (a well known phytoalexin, RSV) and red wine polyphenols (RWP), using UV-B radiated isolated rat hepatocytes as a model of oxidative stress.', 'Rat hepatocytes were isolated by the collagenase method. The cells were loaded with resveratrol and/or polyphenols at different concentrations. The production of thiobarbituric acid reactive substances (TBARS) released by UV-B radiated cells and the levels of lipid-soluble antioxidants (Dolichol, Vitamin E, Coenzyme Q9 and Q10) were measured.', 'Resveratrol had pro-oxidant or antioxidant effects depending on (lower or higher) dosage. RWP protection from photolipoperoxidation was dose-dependent and increased with dosage. Combination of the two compounds exhibited synergistic antioxidant effect, and made resveratrol effective both at lower and higher dosages.'] Does resveratrol require Red Wine Polyphenols for Optimum Antioxidant Activity?