ANTIMICROBIAL AND PHYTOCHEMICAL EVALUATION OF SELECTED MEDICINAL PLANTS IN MERU COMMUNITY OF KENYA

Abstract

The aim of the study was to evaluate antimicrobial potentiality and establish phytochemical profiles of ten medicinal plants collected from the rural communities of Chuka, Tharaka Nithi County of Kenya. Plant samples were collected, dried, pulverized into a fine powder and extracted with distilled water. Phytochemical screening was carried out qualitatively on the aqueous extracts using standard established procedures. Filter‐paper disc‐agar diffusion procedure was used to determine the plant extract activity on four bacterial strains and a fungus. Albizia anthelmintica, Entada leptostachya and Warbugia ugandensis extracts were active against Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli and Candida albicans. E. coli was the most susceptible bacteria against all the plant extracts tested except Harissonia abyssinica. Vernonia lasiopus and Uvariodendron anisatum were the least active extracts. Phytochemical investigation revealed the presence of terpeniods, tannins and reducing sugars in all the plants except one. Saponins were found to be present in A. anthelmintica, E. leptostachya Raponae rhododendroides, and Warbugia ugandesis. Steroids were present in seven plants while alkaloids were present in five plants. Condensed tannins, terpenoids and saponins have been reported to have antimicrobial as well as antihelmintic properties, and their presence in most plant extracts investigated in this evaluation could be attributable to them. Susceptibility against E. coli and C. albicans was significantly comparable to benzathine penicillin and streptomycin. There exist a correlation between antimicrobial activity and phytoconstituents present in the plants evaluated in this study. The type of ailments the plants are claimed to treat by the particular communities can be justified to some extent by the presence of various classes of phytochemicals such as terpenoids associated with antimalarial, tannins and saponins as antibacterial and anthelmintics. In conclusion, the plants evaluated were found to be active against the microorganisms tested. Further investigation for the active phytoconstituents present in these plants can lead to lead compounds for antimicrobial drug development.