Antioxidant activity of polyphenols from seeds of Vitis amurensis in vitro

AIM: To study the antioxidant action of five polyphenols (+) catechin, proc yanidin B-2, procyanidin B-2, procyanidin Bg 3'-O-gallate, and amurensisin isolated from the seeds of Vitis amurensis. METHODS: The mouse liver homoge nate lipid peroxidation assay was applied for the evaluation of the antioxi dant activity in vitro. RESULTS: (+)Catechin, procyanidin B-2, procyanidin B-5, procyanidin B-5 3'-O-gallate, and amurensisin showed antioxidant activ ity with the IC50 values of 0.47, 0.25, 0.10, 0.02, and 0.03 mmol/L, respec tively. The IC50 value of vitamin E used as a positive control was 0.13 mmo l/L. The structural activity relationship was also analyzed. Procyanidins c arrying a galloyl group possessed higher anti-lipid peroxidation activities . All dimers were found to be more potent than the non-galloylated momomer such as (+)catechin. However, the activity of the 4-->6 linked dimer seemed more preferable than 4-->8 linked dimer. CONCLUSION: Procyanidin B-5, proc yanidin B-5 3'-O-gallate, and amurensisin showed a more antioxidant activit y than vitamin E did, and their activity is dependent on their substitution and polymerization patterns.