Phytochemical Screening and Antibacterial Activity of Stachytarpheta indica

Phytochemical screening and antibacterial activity of aqueous and methanolic root extracts of Stachytarpheta indica Vahl. was assessed. Phytochemical analysis revealed the presence of flavonoids, terpenoides, tannins and reducing sugars. The antibacterial properties of both the aqueous and methanolic extracts were studied against clinically important bacteria viz. Escherichia coli, Bacillus cereus, Pseudomonas aeruginosa and Enterobacter aerogens by disc diffusion method. The aqueous extract showed significant activity against all the presently investigated species of bacteria which is comparable with standard antibiotic streptomycin. At the concentrations of 50-100µg /disc, aqueous extract showed significant zone of inhibition against E. coli, (14 mm), B. cereus (13 mm), P. aeruginosa, (17 mm) and E. aerogens (7 mm). Minimum Inhibitory Concentration (MIC) and Minimum Bacterial Concentration (MBC) have been determined. The MIC values observed was 20, 30, 5 and 25µg/ml (for aqueous extract) and 40, 35, 20 and 30µg/ml (for methanolic extract) against E. coli, B. cereus, P. aeruginosa and E. aerogens respectively. Further isolation of active compound responsible for the activity could be the potential sources of new antimicrobial agents.