Author(s): Eneh FU, Onwubiko CE and Ugochukwu GC

Abstract: The menace of antibiotic resistance and the antecedent evolution of innocuous microbes into superbugs is an epidemic of global concern. This study investigated the antimicrobial activity of water and ethanol extracts of Gnetum africanum leaves, a commonly consumed vegetable in most parts of Sub-Saharan Africa, on Staphylococcus aureus, Escherichia coli and Candida albicans. Leaves of G. africanum were extracted with water and ethanol using cold maceration technique; standardized chemical tests were employed for phytochemical screening and the disc-diffusion method used for antimicrobial analysis. Findings indicate that both extracts had dose-dependent inhibitory effect on the growth of S. aureus, with maximum inhibition zones of 13.30 and 13.10 mm at 200 mg/ml for aqueous and ethanolic extracts, respectively. For C. albicans, the ethanol extract proved to be more potent with a maximum inhibition zone of 13.30 mm at extract dose of 100 mg/ mL. However, the extracts did not show any activity against E. coli, suggesting its impotence against gram negative bacteria. The observed antimicrobial activity may be as a consequence of the rich phytochemistry of the leaves, as preliminary phytochemical screening revealed the leaves to contain saponin, flavonoid, cardiac glycoside, alkaloids, tannin and anthraquinones. The findings of this study further reinforces the importance of G. africanum leaves in traditional healthcare practice and its use in culinary. Further investigation is however needed to isolate and purify the bioactive antimicrobial principles for potential development into generic antimicrobials.