Evaluation of the antimicrobial activity of crude extracts and chromatographic fractions of Adenanthera pavonina Linn (Leguminosae) seeds

Abstract

Most available reports on the biological activity of Adenanthera pavonina (AP) are on the bark or leaves and very few are on the seeds. In particular, there are no reports on the biological effects of the chromatographic fractions of A. pavonina seeds hence the present study aimed to evaluate the antimicrobial activity of the crude extract and chromatographic fractions of A. pavonina seeds. The methanolic extract was fractionated and all of the column chromatographic fractions as well as the crude extract were evaluated against different strains of Staphylococcus aureus. The methanolic extract (100 mg/ml) produced zones of inhibition on PHM 002 and PHM 005 while the 50 and 100 mg/ml of the hexane extract only produced inhibition on PHM 001. On the other hand, fractions ST 10-12 F exhibited activity PHM 002 at 50 and 100 mg/ml while fractions ST-13-15F exhibited activity at all concentrations (6.25, 12.5 25, 50 and 100 mg/ ml) against S. aureus PHM 002 strain from the skin. The study provides some justifications for the folkloric use of AP seed powder as an antiseptic paste and warrants further studies to determine the structure of the active compound in chromatographic fraction ST 13 -15F.

Key words: Adenanthera pavonina, antimicrobial activity, chromatographic fractions, methanolic extract.