Antioxidant activity of fruits of Herba Leonuri

The antioxidant activities of extracts and residuum of Herba Leonuri fruits from supercritical CO₂ extraction were determined in vitro. The residuum was extracted in turn with water, propyl alcohol and ethyl acetate. The antioxidant activities of the extracts were assayed with antioxidant capacity in linoleic acid model system, reducing powers, radical scavenging activity using 1, 1-diphenyl-2-picrylhy-drazyl (DPPH) method. The results show that the ethyl acetate extract of Herba Leonuri possesses strongest DPPH radical scavenging activity and reducing power in a concentration-dependent manner.