Antimicrobial activities screening of some phytochemicals from the stem bark extracts of Bersama abyssinica (Fresen)

摘要

Currently, drug resistance among bacterial species is a serious problem in public health thus the discovery and development of new antimicrobial drugs from plants sources would be one of the most exciting areas of pharmacological research. The presentstudy extends the efforts of discovering drug templates from a local medicinal Kenyan plant. The work investigated the phytochemistry and antibacterial activities of stem bark extract of Bersama abyssinica by disc diffusion method. The stem bark of B. abyssinica was extracted at an increasing gradient of organic solvents (n- hexane, dichlomethane, ethyl acetate and methanol). Phytochemistry analysis results confirmed the presence of four main compounds sitosterol, sitosterol glucoside, stigmasterol, and lupeol. Evaluation of antibacterial activities of crude stem bark extracts and the isolated compounds of B. abyssinica carried out through disc diffusion method against Escherichia coli, Staphylococcus aureus, Klebsiella pneumonia, Bacillus subtilis, Vibrio cholerae and Pseudomonas aeruginosa. B. abyssinica methanol stem bark extract exhibited much higher antibacterial activity against the tested pathogenic bacteria. The dichloromethane extract showed mild and moderate antibacterial activity. Resultsproved that B .abyssinica stem bark possessed antipotential bacterial activity. It was concluded that B. abyssinica contains secondary metabolites with antibacterial activity against both Gram positive and Gram negative bacteria. The result of antibacterial activities the plant extracts justifies its continued use in Ethnomedicine.