Preliminary phytochemical and antimicrobial screening of they stem bark extracts of <i>Bauhinia rufescence</i> Lam using some selected pathogens

Abstract

Bauhinia rufescens Lam (Leguminosea-Caesalpinoideae) stem bark was extracted using methanol and fractionated using ethylacetate, butanol and water. The extract and fractions were subjected to preliminary phytochemical screening using standard procedures followed by antimicrobial screening using disc diffusion and broth dilution techniques. The extract and fractions showed the presence of carbohydrate, tannins, flavonoids, saponins, terpenes and steroids. The antimicrobial screening of the extract and fractions against clinical isolates of Staphylococcus aureus, Streptococcus pyogenes, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli and Candida albicans, using disc diffusion method at disc potency of 100μg/disc showed inhibitory activity on the test isolates with zone of inhibition ranging from 16-37mm. The methanolic and ethylacetate extracts showed the least MIC of 1.25mg/mL. The result of the study confirms the traditional use of the stem bark of B. rufescens in the treatment of infections caused by susceptible microorganisms.

Keywords: Bauhinia rufescens, Stem bark, Phytochemical screening, Antimicrobial activity