COMPARATIVE ANALYSIS OF THE ANTIBACTERIAL ACTIVITIES OF DATURA STRAMONIUM FLOWER FROM DIFFERENT SOLVENTS

Abstract

This study was undertaken to analyse the possible antibacterial activity of extracts of Datura stramonium flower. Solvents with varying polarities, were employed in the extraction process, since different secondary metabolites of plant species possess different functional groups with different polarities. Phytochemical and antibacterial activities were assessed using standard methods. The phytochemical analysis revealed that tannins, alkaloids, and flavonoids were present in the methanol, dichloromethane, ethyl acetate and n-hexane extracts; saponins were present in methanol and dichloromethane extracts but absent in ethyl acetate and n-hexane extracts. However, steroids were absent in all four solvent extracts. The antibacterial activities revealed that zones of inhibitions for Staphylococcus aureus and Escherichia coli were (14.0 mm,  9.5 mm) for the methanolic and (8.0 mm, 7.5 mm) for the dichloromethane extracts respectively. Higher zones of inhibition were recorded for the ethyl acetate (24.0 mm, 25.0 mm) and n-hexane (15.0 mm, 20.0 mm) extracts for S. aureus and E. coli respectively implying that they were more susceptible in less polar solvent extracts. The n-hexane and ethyl acetate extracts of the D. stramonium may thus act as broad spectrum antibacterial agents since they are active against gram positive S. areus and gram negative E. coli.