Antibacterial Properties of the Leaf Extracts of Anthocleista djalonensis A. Chev on Some Pathogenic Organisms

Abstract

Aims: To determine the antibacterial effect of methanol, petroleum ether and hot water extracts of Anthocleista djalonensis A. Chev on some pathogenic bacteria and to establish the use of the leaf extract in herbal medicine. Study Design: In vitro assay of antibacterial properties. Place and Duration of Study: Department of Microbiology, Federal University of Technology, Akure, Nigeria, between November 2011 and January 2012. Methodology: Collection of bacterial isolates; preparation of plant extracts; phytochemical screening; in vitro susceptibility test (agar well diffusion assay); minimum inhibitory concentration; antibiotics sensitivity test (disc diffusion assay); rate of killing of plant extracts; sodium and potassium ion leakage. Results: The results of the phytochemical screening showed the presence of tannins, saponins, flavonoids, steroid, terpenoid and cardiac glycosides. All the leaf extracts inhibited all the test organisms except Escherichia coli which was not inhibited by petroleum ether extract. The methanol extract had the highest effect on the test organisms. The minimum inhibitory concentrations (MICs) of the extracts ranged between 10 mg/mL and 40 mg/mL. The result of the antibacterial activity of the leaf extracts compared favourably with the activity of standard antibiotics. It was observed that the number of bacterial cells was decreasing with increase in time of interaction between the extracts and the bacterial cells at a concentration 50 mg/mL of the extracts. There was also increase in the number of sodium and potassium ion leaked from the bacterial cells by the leaf extracts. Conclusion: The results of the study indicate the antibacterial potential of Anthocleista djalonensis A. Chev which may be a source of new bioactive compounds for drug development. The results obtained also establish the use of the plant in traditional phytomedicine for the diseases caused by the microorganisms.