Antimicrobial and Phytochemical Screening of Methanol Extracts of Three Medicinal Plants in 1ethiopia

Abstract

5 Abstract: Medicinal plants play a key role in the development and advancement of modern studies by serving as a starting point for the development of novelties in drug. The World Health Organization (WHO) estimates that about 80% of the world's people relay chiefly on traditional medicine, mostly of plant origin to meet their primary health care needs. In Ethiopia medicinal plants, Calpurnea aurea, Hypericum revolutum and Peterollobium stellatum traditionally used to treat amoebic dysentery, stomachache and respiratory diseases, respectively. The current study was conducted to investigate the antibacterial activity these plants against bacterial isolates. In vitro antibacterial activity against Salmonella typhi, Salmonella paratyphi, Salmonella typhimurium, Shigella species, Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli was performed. The tests were carried out using the agar well diffusion method at 250 mg/mL concentration of the crude extracts. The minimum inhibitory concentrations (MICs) of the extracts were determined against these microorganisms using micro dilution. These plant extracts exhibited minimum inhibitory concentration values ranging 125 mg/mL to 250 mg /mL against some bacterial isolates. Among these three plant species; P. stellatum was found to be the most active against S. typhi, Salmonella paratyphi, P. aeruginosa, S. aureus and E. coli. Out of seven clinical bacterial isolates tested, P. aeruginosa and E. coli were found to be more sensitive to the plant extracts than other bacterial isolates. The results indicated the potential of these herbal drugs in treating bacterial infections.