Abstract

Herbal medicine is readily available in diverse African vegetation with the potentials of introducing new templates into medicine worldwide. Evaluating plants from the traditional African system of medicine provides us with clues on how these plants can be used in the treatment of diseases. In vitro effect of Nauclea latifolia extract in hot water, cold water, petroleum ether and chloroform at concentrations of 200, 150, 100, 50% were tested on some pathogenic bacteria such as Staphylococcus aureus, Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa. Using agar diffusion punch hole method, both the aqueous and alcoholic extracts of the leaves and roots showed appreciable inhibitory effect when compared to the positive control on S. aureus and P. aeruginosa while S. typhi and E. coli were resistant to the extracts. Using serial doubling dilution, the minimum inhibitory concentration (MIC) was determined. The minimum bacteria concentration was determined by plating various dilutions of the extracts without turbidity. Aqueous and alcoholic extracts of N. latifolia showed inhibitory and bactericidal activity on the test organisms. The alcoholic extracts showed larger zone of inhibition on the test organisms. The alcohol leaf extracts showed a higher percentage of growth inhibition when compared to the positive control. The MIC ranges from 6.25 – 150 mg/ml on S. aureus and 12.5 – 150 mg/ml for P. aeruginosa. The MBC ranges from 100 – 150 mg/ml. The phytochemical analysis revealed the presence of saponin, resins, alkaloids, and carbohydrate.

Key words: Antimicrobial potentials, Nauclea latifolia, bacterial pathogens, Nigeria.