QUALITATIVE PHYTOCHEMICAL SCREENING AND IN VITRO ANTIMICROBIAL EFFECTS OF METHANOL STEM BARK EXTRACT OF FICUS THONNINGII (MORACEAE)

Abstract

The methanolic stem bark extract of Ficus thonningii (Moraceae) was subjected to preliminary phytochemical screening and in vitro antimicrobial tests. The phytochemical tests was carried out using standard methods of analysis and these investigations revealed the presence of alkaloids, anthraquinones, carbohydrates, flavonoids, saponins and tannins. The antimicrobial activity of the plant extract was assayed using the agar plate disc diffusion and nutrient broth dilution techniques. Test micro organisms were: Escherichia coli, Klebsiella spp, Pseudomonas aeruginosa, Salmonella typhi (Gram-negative), Staphylococcus aureus and Streptococcus spp. (Gram-positive). The extracts inhibited the growth of all the test organisms at different concentrations especially against Pseudomonas aeruginosa and Streptococcus spp. which had mean inhibition zone of 33.33±7.33 mm and 32.33±2.51 mm respectively. The results showed the MIC of 10 mg ml-1 against pseudomonas and 1.25 against remaining organisms tested. The MBC against Staphylococcus aureus was 2.5 mg ml-1 and that of Streptococcus spp. was found to be 0.625mg ml-1. The extracts showed varied inhibitory activity against the organisms studied.