Phytochemical screening and antibacterial activities of aqueous and ethanolic extracts of the stem bark and leaves of Bauhinia rufescens

Abstract

The Bauhinia rufescens stem-bark and leaves were extracted using water and ethanol. The ethanol extracts were fractionated using petroleum ether, chloroform, ethyl acetate and methanol. The aqueous extracts, the fractions and the fractionation residues of the ethanol extracts were subjected into phytochemical screening and antibacterial activity testing using standard methods. The phytochemical screening revealed the presence of alkaloids, carbohydrates, resins, saponins, sterols and tannins in the extracts and fractions of the plant materials. In-vitro antibacterial activities of the extracts and fractions were investigated against Staphylococcus aureus, Proteus vulgaris, Streptococcus pneumoniae, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Streptococcus pyogenes, Salmonella typhi and Shigella dysenteriae using agar-disc diffusion method. waThe aqueous extracts, the fractions of ethanol extracts and the fractionation residues of the Bauhinia rufescens stem-bark and leaves showed antibacterial activities against the test bacterial isolates. The chloroform and methanol fractions of the stem bark as well as the methanol fraction and the aqueous extract of the leaves showed MIC and MBC against some test bacterial isolates within the range of 10mg/ml to 40mg/ml. The overall results of the study suggested that the stem-bark and leaves of Bauhinia rufescens could be a good source of antibacterial compounds.