Toona sinensis Roem. (Meliaceae; T. sinensis), a kind of arbor, is widely distributed in Asia. Long used as a nutritious food in Chinese society, T. sinensis is very popular for vegetarian cuisine in Taiwan. The aim of the present study was to investigate the antioxidant activity of aqueous extracts of Toona sinensis (TS; 0-100 mg/mL) and gallic acid (0-50 mg/mL), with the purified natural phenolic components evaluated using different antioxidant models. It was found that the TS extracts and gallic acid possess effective antioxidant activity against various oxidative systems in vitro, including the scavenging of free and superoxide anion radicals, reducing power, and metal chelation. However, antioxidant activity in terms of metal chelation was not observed for the gallic acid. Furthermore, AAPH-induced oxidative hemolysis, lipid peroxidation, and decline in superoxide dismutase (SOD) activity in human erythrocytes were prevented by both the TS extracts and the gallic acid. Our findings suggest that Toona sinensis may act as a chemopreventative agent, providing antioxidant properties and offering effective protection from atherosclerosis.?
