Inhibition of Lipid Peroxidation and Radical Scavenging Effect of Anthocyanin Pigments Isolated from the Seeds of Phaseolus vulgaris L.

Recently, there has been increasing interest in the protective biochemical function of natural antioxidants contained in dietary plants, which are candidates for the prevention of oxidative damage caused by oxygen-free radical species. However, little attention has been paid to the antioxidative activity of edible beans. This background prompted us to investigate the antioxidative activity of bean seeds chemically. Three anthocyanin pigments, cyanidin 3-O-β-D-glucoside (C3G), pelargonidin 3-O-β-D-glucoside, and delphinidin 3-O-β-D-glucoside were isolated and identified from the seed coat of Phaseolus vulgaris L. Among the isolated pigments tested, C3G had marked antioxidative activity in liposomal and rat liver microsomal systems, an inhibitory effect on malondialdehyde (MDA) levels by UV light irradiation, and radical scavenging effects against hydroxyl and superoxide anion radicals. On the basis of these results, C3G was reacted with a radical initiator in a model system and the antioxidative mechanism was discussed. Anthocyanin pigments are widely distributed in the human diet through cereal crops, beans, fruits, and vegetables, indicating that we ingest considerable amounts of anthocyanin pigments from plant-based daily foods, and these pigments may play an important role as dietary antioxidants for the prevention of oxidative damage in living systems.