Free radical scavenging activity of crude extracts and 4´-O-methylepigallocatechin isolated from roots of Cassine transvaalensis Burtt-Davy from Botswana

Motlhanka, D.M.T, Habtemariam, S. and Houghton, P. (2008) Free radical scavenging activity of crude extracts and 4´-O-methylepigallocatechin isolated from roots of Cassine transvaalensis Burtt-Davy from Botswana. African Journal of Biomedical Research, 11 (1). pp. 55-63. ISSN 1119-5096

Abstract

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-methylepigallocatechin 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.

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