Protection of lipid peroxidation and carbonyl formation in proteins by capsaicin in human erythrocytes subjected to oxidative stress.

Capsaicin (8-methyl-N-vanillyl-6-nonemide) is the major pungent principle found in hot peppers of the plant genus Capsicum. The present work was undertaken to investigate the antioxidative property of capsaicin on markers of oxidative stress; membrane lipid peroxidation (formation of malondialdehyde) and membrane carbonyl groups in human erythrocytes. The effect of capsaicin has been compared with l-ascorbic acid. Subjecting erythrocytes to oxidative stress by incubating them with t-BHP caused a significant increase in MDA level and protein carbonyl group content above the basal value. The presence of capsaicin (10 microm) in the incubation medium protected the erythrocytes from t-BHP-induced oxidative stress as evidenced by the decrease in MDA level and protein carbonyl group content, l-ascorbic acid also showed similar protective effect. The results conclusively prove the efficacy of the antioxidant property of capsaicin. This evidence suggests that dietary factors that act as antioxidants to decrease membrane lipid peroxidation and protein carbonyl formation may contribute to a protective effect against cancer, atherosclerosis and age related diseases. This antioxidant effect may, in part, explain the high consumption of capsicum in certain regions of the world. Copyright 2006 John Wiley & Sons, Ltd.