Antioxidant Activity of 13 Medicinal Plants

Abstract

The aqueous extracts of 13 medicinal plants widely used in oriental medicine were examined for their reducing power, scavenging ability toward superoxide and hydroxyl radicals, and their inhibitory effect on lipid peroxidation. The reducing power of Herba Lycopi and Cortex Gleditsiae was more apparent than with other plants. All extracts tested were found to be highly active on scavenging of superoxide radicals. Among them, Fructus Crataegi, Herba Leonuri, Cortex Gleditsiae, and Herba Lycopi composed the highly active group. Although the overall level of hydroxyl radical scavenging activities tended to be lower than those for super-oxide radicals, Fructus Crataegi and Cortex Gleditsiae were found to act most effectively. Inhibitory effects on lipid peroxidation were examined using a rabbit erythrocyte-ghost system, and a high inhibition was obtained by Rhizoma Rhei, Fructus Crataegi, and Cortex Gleditsiae. Reversely, strong pro-oxidant activity was found in five medicinal plants including Semen Thujae Orientalis in this assay system.

Keywords: :

• Antioxidant activity
• oriental medicinal plants
• reactive oxygen species