Cytotoxicity and antimicrobial activity of methanol extract and fractions of Entandrophragma angolense (Welw.) C.DC. (Meliaceae) leaves

Abstract

The antibacterial activity and brine-shrimp lethality (BSL) assay of methanol extracts of Entandrophragma angolense, used id treat gastro-intestinal tract (GIT) infections in South-Western Nigeria was investigated. The extract and chromatographic fractions were tested at 20 and 10 mg/mi respectively against Staphylococcus aureus (ATCC 25923), Pseudomonas aeruginosa (ATCC 27853). Salmonella lyphi (clinical isolate), Salmonella typhimurium ATCC 14028, Escherichia coli (ATC 1C 25922) and Bacillus suhlilis (ATCC 6633) using agar-well diffusion method; Minimum 'Inhibitory Concentrations (MIC) were determined by agar dilution method. Further, the extract was fractionated on siiic-a gel (70-230 mesh) using column chromatography. The diameter of zonr.s of inhibition were between) 5.0 - 30.5m m which was comparable with gentamicin (10pg/nil) used as ’’ control. The MIC was 80.0j.tg/ml on Staph, aurevs and 350pg/ml on Salmonella typhi. The more poUir fractions contained the antimicrobial com pouxr as the less polar fractions showed no antimicrobial activity as tested. Phytochemical screening revealed the presence of tannins, flavonoids, reducing sugars and steroidal compounds. Brine shrimp lethality assay gave a value of 62.5f.ig/mJ. Therefore E. angoiense leaves contains antimicrobial agents and cytotoxic principles to justify its folkloric uses and pby (otherapeutio potentials in treating infections.