Antimicrobial Effects of Bitter Kola (Garcinia Kola) Nut on Staphylococcus Aureus, Eschererichia Coli and Candida Alibicans

Abstract

This study was conducted to test for the antimicrobial activity of Garcinia kola (Aku-inu) against some microbial organisms, namely: Staphylococcus aureus, Escherichia coli and Candida albicans. The paper disc method was used to determine the inhibitory effect of Garcinia kola nut on the test micro-organisms. The zones of inhibition for Staphylococcus aureus ranged between 0.5 to 5mm for the ethanol preparation of Garcinia kola nut while that of E. coli ranged between 0.3 to 3.2mm. The ethanol preparation of Garcinia kola nut was found to exhibit more significant inhibitory action against test organisms than the aqueous preparations of Garcinia kola nut. Staphylococcus aureus in both preparations gave wider zones of inhibition than E.coli while Candida albicans exhibited no response. Minimal zones of inhibition started from 40% ethanol and diameter of inhibition increases with increase in ethanol concentration for E.coli, while Staphylococcus aureus started from 20% ethanol increasing in diameter as the concentration of ethanol increases. Candida albicans showed no zone of inhibition. Minimal zones of inhibition for the different weights of Garcinia kola nut/disc in 1ml of aqueous preparation of Garcinia kola nut started from the discs containing 300µg and 400µg for Staph. aureus and E. coli respectively, with diameters of 0.3mm and 0.4mm. Candida albicans showed no response to the different weights of Garcinia kola nut per ml of water. Statistically, results showed that ethanol preparation of Garcinia kola nut exhibit more significant activity (p<0.001) than the aqueous preparation of Garcinia kola nut (p<0.01). The results of the Garcinia kola nut may be attributed to the presence of some pharmacokinetic compounds.