Evaluation of The Antimicrobial Potentials of Leaf Extracts of Khaya senegalensis
Abstract
The leaf of Khaya senegalensis was screened for antimicrobial activity. Plant components were extracted using ethanol and water. The ethanol and aqueous extracts of the leaf were tested against Staphylococcus aureus, Streptococcus faecalis, Salmonella typhi, Escherichia coli and Candida albicans using disc diffusion method and results compared with standard antibiotics, tetracyclines and ampicillin. The ethanol extract showed activity against S. aureus and S. typhi at the lowest concentration of 100µg/ml with the diameter zone of inhibition (DZI) of 16±0.1 and 14±0.1 respectively. E. coli was susceptible at 1000µg/ml showing zone of inhibition of 12±0.2. S. feacalis was only susceptible at a higher concentration (10000µg/ml). The aqueous extract demonstrated weaker activity against the organisms; it was only active as from the concentration of 1000µg/ml. The minimum inhibitory concentration of ethanol extract against organisms ranged from 100µg/ml to 1000µg/ml while that of aqueous extract ranged from 1000µg/ml to 10000µg/ml. Higher concentrations were required to produce bactericidal effect on the organisms. Phytochemical screening of extracts revealed the presence of plant secondary metabolites such as Saponins, Cardiac glycosides, Tannins, Alkaloids and Anthroquinones. The aqueous extract contains only three of the five metabolites mentioned above. That may be the reason for its weaker activity against the organisms. Ethanol extract had the highest inhibitory action on the test organisms probably because it contains more the secondary metabolites than the aqueous extract. Leaf extracts from this plant may be useful in the treatment of some diseases whose causative agents were susceptible to it in-vitro.
Evaluation of The Antimicrobial Potentials of Leaf Extracts of Khaya senegalensis
