Scavenging effect of tetrandrine on active oxygen radicals

The scavenging effects of tetrandrine (TD) on active oxygen radicals were investigated through chemiluminescence experiments and oxidation of ferrocytochrome c. The superoxide anions (O-2(-.)) were generated either in hypoxanthine/xanthine oxidase (HX-XOD) system or by means of auto-oxidation of erythrocytes. It was found that TD (7.5 mu M) could remarkably scavenge O-2(-.) in the HX-XOD system and that the effect was concentration-dependent. The scavenging effect of TD on O-2(-.) generated from auto-oxidation in erythrocytes was not as strong as in the HX-XOD system. The hydroxyl radicals (. OH) were generated in aqueous solution of H2O2 irradiated by UV, it was also found that TD (15 mu M) effectively scavenged . OH in that system. This study led to the conclusion that the antioxidant property of TD may account for some of its pharmacological effects.