Antibacterial activity of the leaf and stem bark crude extracts of Khaya senegalensis

The antibacterial activity of the aqueous and ethanolic leaf and stem bark crude extracts of Khaya senegalensis against four bacteria species (Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcus pneumonia and Escherichia coli) was investigated using the agar well diffusion technique. At concentrations ranging from 400 to 1000 mg/ml the ethanol crude extracts showed activity against the four bacteria species, with mean zone of inhibition ranging from 7.67 ± 0.33 a to 19.66 ± 0.33 b . Similarly the aqueous crude extract at 400 to 1000 mg/ml recorded low activity with mean zone of inhibition ranging from 0.33 ± 0.33 a to 13.3 ± 0.33 c . Minimum inhibitory concentrations of the crude extracts were 200 and 400 mg/ml and the minimum bactericidal concentration was also 400 and 800 mg/ml. The lethal dose (LD50) of the crude extracts of K. senegalensis was found to be greater than 5000 mg/kg. The phytochemical components of the crude extracts include alkaloid, steroids, glycosides, tannins, saponins and flavonoids. The study revealed that the plant could be a potential source of antibacterial agent.