Determination of antioxidant activities of dried kacangma (Leonurus sibiricus) extract in three bioassay systems

Kacangma (Leonurus sibiricus L.) is a potential medicinal and culinary herb of Sarawak and its biological activities have not been fully studied. Antioxidant activities of ethanol and aqueous extracts of dried kacangma were studied under three bioassay systems, namely, auto-oxidation of linoleic acid lipid system (LP), xanthine oxidase superoxide scavenging activity (XOD) and 1,2-diphenyl- 2-picrylhydrazyl radical scavenging activity (DPPH). Based on the antioxidant activity range, antioxidant activity of ethanol extract was high in LP system (72%), moderate in XOD system (70%) and low in DPPH system (49%). On the other hand, antioxidant activity of aqueous extract was found high in all three bioassays with mean percentages of 73, 76 and 78% for LP, XOD and DPPH respectively. Thus, the results indicated that extraction using water was more efficient than ethanol in extracting antioxidant compounds from dried kacangma