ANTIBACTERIAL ACTIVITIES OF THE METHANOL EXTRACT AND FRACTIONS OF THE LEAF OF ERIOSEMA PSORALEOIDES (LAM.) G. DON (LEGUMINOSAE)

Eriosema psoraleoides leaves have been reported to be used in traditional African medicine to treat cuts and wounds, hence the present investigation of its antibacterial activity using the agar pour plate method.  The leaves contain tannins and flavonoids. A methanol extract was obtained from the leaves by maceration, and then the n-hexane and ethyl acetate fractions were obtained from this. Statistical analysis of data was by ANOVA, with p<0.05 considered significant. The methanol extract, n-hexane fraction and ethyl acetate fraction were found active against Staphylococcus aureus ATCC 25923, and Staphylococcus aureus Clinical isolate; in addition, the methanol extract was active against Pseudomonas aeruginosa.  However, Staphylococcus aureus Clinical isolate was found resistant to Gentamicin. The Minimum Inhibitory Concentrations (MICs) of the extract and fractions against Staphylococcus aureus ATCC and against Staphylococcus aureus Clinical isolate, showed that ethyl acetate fraction was more active than the other two fractions. Although Staphylococcus aureus was found to be resistant to Gentamicin, it was susceptible to the antibacterial activity of the methanol extract, n-hexane fraction, and ethyl acetate fraction of the plant. This suggests that these extract/fractions may be useful in treating infections caused by Staphylococcus aureus.