COMPARATIVE ANTIMICROBIAL ACTIVITIES OF THE LEAVES OF COMBRETUM MICRANTHUM AND C. RACEMOSUM

Abstract

The leaves of Combretum micranthum and C. racemosum are used as herbal remedy to treat diarrhoea and various skin diseases. The ethanol extract, n-hexane, chloroform, ethylacetate, n-butanol and aqueous fractions of C. micranthum and C. racemosum leaves were evaluated for in vitro antimicrobial activities by agar-diffusion and tube-dilution methods to validate the ethnobotanical uses of the two species and to compare activities. The ethanol extract and ethylacetate fraction showing milder activity. The chloroform, n-butanol and aqueous fractions also showed significant activity against Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Candida albicans and Trichophyton rubrum. They showed more potent activity against S.aureus and P. aeruginosa than did the standard drug. N. hexane fraction yielded the least activity. Conversely, the ethanol extract of Combretum racemosum showed no activity against any of the test organisms. However, all the fractions exhibited some fairly reasonable activity, with n-hexane fractions yielding the broadest spectrum of activity and ethylacetate fraction the least. The minimum inhibitory concentration of the ethanol extract and the fractions of Combretum micranthum ranged from 0.62-15mg/ml, while fractions of C. racemosum yielded values from 2.5 10mg/ml. Combretum micranthum afforded far greater antimicrobial activity than C. racemosum.


KeyWords: Combretum micranthum, C.racemosum, antimicrobial activity.


(Global J Med Sci: 2002 1(1): 13-17)