Authors : C.U. Iroegbu and C.K. Nkere
Abstract: The antibacterial activity of the alcohol extract of the stembark of Picralima nitida was tested against Staphylococcus aureus ATCC12600, Pseudomonas aeruginosa ATCC 10145, Bacillus subtilis ATCC 6051, Escherichia coli ATCC 11775, Salmonella kintambo Human 1,13,23 mt: and three clinical isolates. The antibacterial assay was by both the agar-well diffusion and macro-broth dilution methods. Separation of the crude extract by column chromatography yielded six fractions of which, all contained alkaloid except F . The spectra of activity for the crude extract and active fractions was 50% each, with no apparent activity recorded against the clinical isolates. Fractions F and F exhibited no antibacterial activity. The control drug, Gentamicin 1 5 had 62.5% spectrum of activity. There was significant difference (p<0.05) in antibacterial activity between the crude extract and its fractions, with F exhibiting the highest antibacterial activity. The MIC range for the crude was 25-50 mgmLG ; F , 3.125-50 mgmLG ; F , 1.563-50 mgmLG and F , 3.125-50 mgmLG . The combined activity of the fractions showed that the active components might be antagonistic to one another. Both the MBC and kill-rate study show that the partially purified fractions had higher bactericidal effect as compared to the crude extract. These results provide scientific justification for the use of locally distilled alcohol, as solvent for most herbal preparations.
C.U. Iroegbu and C.K. Nkere , 2005. Evaluation of the Antibacterial Properties of Picralima Nitida Stembark Extracts. International Journal of Molecular Medicine and Advance Sciences, 1: 182-189.