Invitro Antibacterial Activity of Dodonaea Angustifolia and Withania Somnifera Plants Against Some Bacterial Human Pathogens

Abstract

Medicinal plants are the wealthy source of various antibacterial agents. The objective of this study was to evaluated antibacterial activity of ethanol, methanol acetone, diethyl ether and hexane leave extracts of Dodonaea angustifolia and Withania somnifera using paper disc diffusion and broth dilution methods against six human pathogenic bacterial strains. The pathogenic bacteria such as Escherichia coli, Shigella dysenteriae, Pseudomonas aeruginosa, Staphylococcus aureus, Klebsiella pneumoniae and Salmonella typhi were susceptible to ethanol, methanol and acetone extracts of the leaves of Withania somnifera followed by Dodonaea angustifolia,but hexane extract did not showed any activity. The maximum inhibition zone of 16.3±0.57mm was observed against E coli by ethanol extract of Withania somnifera and MIC of 3.125mg/ml against Escherichia coli and Shigella dysenteriae by methanol extract. The methanol extract of Dodonaea angustifolia produced a pronounced inhibition of 13.1±0.37mm against Escherichia coli and ethanol extract of D. angustifolia showed activity against Shigella dysenteriae 14.4±0.45mm and MIC of 6.25mg/ml against I. and S. dysenteriae. Four different antibiotics like Ciprofloxin, Tetracyclin, Kanamycin and Chloramphenicol were used as standard for the testing of antibacterial activity against six different human pathogens. Among the antibiotics Ciprofloxin showed maximum zone of inhibition ranging from 20-35mm followed by Kanamycin, Tetracycline and Chlormphenicol. The activities are attributed to the presence of some secondary metabolites present in the tested plants which have been associated with antibacterial activities. The obtained result forms a good basis for selection of plant species for further investigation in the potential discovery of new natural bioactive compounds.

Keywords: Invitro antibacterial activity, Human pathogens, Plants