Antimicrobial Assay of Aqueous Extracts of Selected Ethno-pharmacologic Alternatives Used by the Maasai Community of Narok, Kenya

Abstract

Aims: Antimicrobial resistance motivates the search for new antimicrobials. Besides Methicillin- Resistant Staphylococcus aureus, Carbapenem-Resistant Klebsiella pneumoniae strain has emerged worldwide over the last decade, posing a great challenge to healthcare. This paper reports a survey of Maasai ethno-pharmacy practices. Study Design: Key informant interviews and utilization of e-questionnaires for data collection. Methodology: Plants were identified, and the applicable parts taken as samples, dried, powdered then subjected to aqueous extraction. Using agar well diffusion method, the extracts were screened against gram positive, gram negative and fungal strains to establish antimicrobial activity. Place and Duration of Study: The study was conducted at the School of Pharmacy & Health Sciences of the United States International University, Africa in Nairobi from January 2017 to December 2018. Results: Out of the 24 different plant samples collected, 33% were leaves while 17%, 12.5% and 37.5% were fruits, stem bark and roots, respectively. The highest extract percentage yields were from the leaves of Biden pilosa (5.11%), Psidium guajava (4.65%) and Tarchononthus comphoratus (4.31%). While the minimum extracts yields were from Solanum incum roots (0.08%) and stem bark (0.09%). The extracts of Toddalia asiatica stem bark and roots; Rhamnus staddo roots; Tarchonanthus camphoratus stem bark and roots; and Zanthroxyleum chelybeum stem bark, all exhibited well defined inhibition diameters against M.R.S. aureus in the range 8mm to 14mm as compared to the standard drug (10mm). All these were extracts of non-leafy samples. The significant antimicrobial activity corresponded to presence of flavonoids and alkaloids as seen on TLC plates during phytochemical screening. Conclusion: The results obtained are a good rationale for utilization of the plants identified as alternatives to antibiotics for management of antimicrobial infections.