Phytochemical screening and antimicrobial activities of the stem bark of Allanblackia parviflora Chev. (Clusiaceae)

Abstract

This study has successfully explored the photochemistry and antimicrobial properties of the methanolic, aqueous and pet ether stem bark extracts of Allanblackia parviflora (Chevalier) (Clusiaceae). The qualitative phytochemical screening revealed the presence of alkaloids, tanins, flavonoids, cardiac glycosides, reducing sugar, triterpenoids, anthraquinones, saponins and phytosterols in the various plant samples and the absence of cyanogenic glycosides in all the samples screened. The antimicrobial assay employed Agar-well diffusion for the preliminary screening and Micro broth dilution method for the MIC determination. Ten (10) microbial strains including one fungus (Candida albicans), five gram-negative (Salmonella typhi, Neisseria gonorrhoeae, Escherichia coli ATCC 2592, Klebsiella pneumoniae and Pseudomonas aeruginosa ATCC 4853) and four gram-positive bacteria (Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Streptococcus paratypi A and Bacillus subtilis NCTC 10073) were employed in the assay using Ciprofloxacin as the reference drug. The methanolic extract exhibited the highest activity against E. faecalis with zone of inhibition 20 mm and MIC of 2.5 mg/ml. Pet ether extract on the other hand was inactive against test microbes. The results from the study therefore suggest that the stem bark of Allanblackia parviflora possess some phytochemicals that acts synergistically to provide the observed antimicrobial properties as claimed by traditional medicine.