Authors : E.O. Ekundayo and L.I. Ezeogu
Abstract: Ten extracts from five Nigerian medicinal plants were screened for antimicrobial activity using disc agar diffusion and micro dilution broth assays. Methanol and Dichloromethane extracts of each of the plants were tested against five collection culture microorganisms consisting of two Gram positive (Staphylococcus aureus ATCC 12600, Bacillus subtilis ATCC 6051) and two Gram negative (Escherichia coli ATCC 11775 and Pseudomonas aeruginosa ATCC 10145) bacteria and the pathogenic yeast, Candida albicans(ATCC 18804). All the extracts exhibited moderate to high level of broad spectrum antimicrobial activities against these microorganisms. The antimicrobial activity was measured by the diameter of zone of inhibition and Minimum Inhibitory Concentration (MIC). The diameters of zones of inhibition range from 7mm-30mm at 2000�g mL of crude extract per disc. The MIC values were between 31.5�g mL-500�g mL or greater. The activities of some of the crude extracts were comparable to the reference antibiotics at standard concentrations used per disc. The potential of these Nigerian medicinal plants for development of cheap, culturally acceptable standardized herbal medicines and as sources of novel molecules for broad spectrum antimicrobial agents is discussed.
Ekundayo, E.O. and L.I. Ezeogu , 2006. Evaluation of Antimicrobial Activities of Extracts of Five Plants Used in Traditional Medicine in Nigeria. International Journal of Tropical Medicine, 1: 93-96.