Vol. 6, Issue 12 (2017)

Author(s):
Lambert Okwubie and Chukwudi Chukwudi Senior

Abstract:
This work was conducted in other to obtain preliminary information on the antimicrobial potential of the petroleum ether, ethyl acetate and methanol crude root extracts of Allamanda cathartica (Apocynaceae). Each of the root extracts was screened in vitro for antimicrobial activity against Staphylococcus aureus, klebsiella pneumoniae, Streptococcus pneumoniae, Escherichia coli and Candida albicans, by agar well diffusion method, at the concentrations of 50mg/ml, 100mg/ml and 150mg/ml. The ethyl acetate extract was the only extract active against all the bacteria used in the study it was also the only extract active against Escherichia coli producing mean inhibition zone diameters of 10±1.05mm, 14±2.0mm and 16±2.0mm for concentrations of 50mg/ml, 100mg/ml and 150mg/ml respectively. It was also the most active against S. pneumoniae and K. Pneumoniae. The methanol extract had the greatest activity of all the extracts against S. aureus with mean inhibition zone diameters of 16±1.35mm, 18±0.0mm and 17±1.41mm at 50mg/ml, 100mg/ml and 150mg/ml respectively. The Minimum Inhibitory Concentration of the ethyl acetate extract (being the most active) was determined against S. aureus, E. coli, K. pneumonia and S. pneumoniae and it was found to be 12.5mg/ml, 25mg/ml, 50mg/ml and 50mg/ml respectively. The extracts were not active against candida albicans. Conclusively, the ethyl acetate and methanol extracts of Allamanda cathartica showed good antibacterial activities and can serve as a lead to the development of new antibacterial agents.