Water and ethanol extracts of roots from Cassine transvaalensis
Burtt-Davy (celastraceae) were assessed for in vitro
antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay. The ethanolic extract exhibited higher free radical scavenging effect than the water extract at all tested concentrations. Above 100µg/ml, the ethanolic extract showed 80% scavenging activity, similar to control antioxidant compounds quercetin, rutin and L-ascorbic acid. The water extract reached a similar level of activity (80%) at 200µg/ml. Between 20-50µg/ml, 4'-O-methyl-epigallocatechin isolated by bioassay directed fractionation exhibited scavenging activity greater than that of either the ethanolic or aqueous crude extract. However, at concentrations above 50µg/ml, the scavenging activity of the ethanolic extract exceeded that of 4'-O-methyl-epigallocatechin.The results suggest that extracts from the roots of Cassine transvaalensis
have strong antioxidant activity. These findings support the ethnomedical use of this plant to promote good health.