Exploring the Antimicrobial Efficacy of Embelia Keniensis Leaf Extracts against Selected Microbial Strains

Abstract

The pursuit of novel bioactive compounds from natural sources has prompted an assessment of the antimicrobial properties and phytochemical composition of Embelia keniensis leaf extracts. Embelia keniensis is one of the five Myrsinaceae species endemic to Kenya. The interest in the scientific investigation of Embelia keniensis crude extracts is based on the claims of their effective use for the treatment of many diseases such as chest pains, common cold and stomach ailments. The plants used in this study were derived from Brackenhurst Botanical Garden Limuru sub-county, Kiambu County, central Kenya. The study was conducted from January to March 2023 at the Jomo Kenyatta University of Agriculture and Technology. The study aimed to evaluate the antimicrobial potential of crude extracts of this plant against Escherichia coli, Staphylococcus aureus, and Candida albicans. The antimicrobial activity was determined through the disc diffusion method. Both methanol and water were employed for extraction; however, neither demonstrated promising activities against the test organisms. Notably, the water extract exhibited greater potency compared to the methanolic extract against Escherichia coli. The water extract displayed a maximum inhibition zone of 9mm at a concentration of 1mg/ml. similar findings were observed for Staphylococcus aureus and Candida albicans with inhibition zones of 9mm and 7 mm, respectively, at the same concentration. Preliminary phytochemical screening identified the presence of bioactive agents such as saponins and flavonoids, while tannins and terpenoids were absent. Despite the observed zones of inhibition, the plant extract fell short of meeting the clinical and laboratory standards institute breakpoints for susceptibility and intermediate levels. Instead, they exhibited resistance breakpoints, rendering the plant extracts ineffective for antimicrobial activities. Nevertheless, this outcome does not negate the potential of the plant extract. Factors like mode of action and microorganism susceptibility could influence their effectiveness. Further evaluation is warranted to fully comprehend the potential of Embelia keniensis extracts. This study provides insight into their antimicrobial activity and a preliminary phytochemical profile.