Antibacterial and Antagonistic Activity of Selected Traditional Medicinal Plants and Herbs from East Wollega Zone against Clinical Isolated Human Pathogens

Abstract

Traditional medicinal plants and herbs are used by the communities of western Ethiopia including Wollega administrative zones; although in most cases no scientific studies have been done to prove the efficacy of these medicinal plants. To provide evidence evidence- based data for traditional medicinal plants which are very important heritages and used by our community at large, research based screening is very important. Therefore, in this study laboratory based assessment of medicinal plants commonly used by the order of traditional practitioners in east Wollega administrative zone was carried out. Nine plants samples were collected from different areas of east Wollega administrative zone of and were analyzed for their antimicrobial activities. The diethyl ether and methanol extracts of some medicinal plants have inhibited bacterial strains; Streptococcus pyogenes, Streptococcus pneumonia, Streptococcus agalacticeae, Salmonella tphyrium, with minimum inhibition concentration of 25% (25 mg/mL) of the stock solution (100 mg/mL). S.pneumonia was found to be the most susceptible bacteria for the methanol extract of the root of Ricinus communis with inhibition zones of 20mm and MIC of 25 mg/mL. However; S.tphyrium was the most resistant to all extracts of the selected plants with no inhibition zone. The methanol extracts of all plants were most potent while the diethyl ether extracts of all medicinal plants were ineffective against all bacterial strains. As such, it can be concluded that Ricinus communis had shown antibacterial activity having potential for further study followed by Millettia ferugunea to serve as source of antibacterial agents in the future.