Phytochemical Screening and In vitro Antibacterial activity of Some Medicinal Plants Belonging to Guntur, India

Four medicinal plants viz., Adathoda vasica, Terminalia chebula, Casia angustifolia and Asparagus racemosus were used for investigating their antibacterial activity against selected bacterial pathogens using agar diffusion method. Ethyl acetate extracts of A. vasica showed maximum zone of inhibition against Escherichia coli (35 mm), Staphylococcus aureus (33 mm) and Bacillus subtilis (33 mm). Ethyl acetate extract of T. chebula showed highest zone of inhibition against Pseudomonas aeruginosa (34 mm). Whereas, aqueous extracts of all medicinal plants showed poor antimicrobial activity. Comparative studies with antibiotic ampicillin showed that, ethyl acetate extracts of A. vasica was found to be effective compared to ampicillin. Ethyl acetate extracts of A. vasica showed least MIC value of 3.21 μg/ml against E. coli. Ethyl acetate extracts of T. chebula, S. angustifolia and A. racemosus showed least MIC values of 6.25 μg/ml, 12.5 μg/ml and 50 μg/ml respectively. Preliminary phytochemical analysis of selected medicinal plants showed that, carbohydrates and saponins were present in all plants used in the study. Alkaloids were found to present in A. vasica, T. chebula and C. angustifolia. Flavanoids were found to present in C. angustifolia and A. racemosus. Steroids were found to be present in A. vasica and T. chebula, while Tannins were found to be present only in A. vasica.