Comparative evaluation of in vitro antibacterial activity of several extracts of Achyranthes aspera, Azolla pinnata, Cissus quadrangularis and Tinospora cordifolia

Plants have provided anti- infective agents in the form of alkaloids, flavonoids, phenols, tannins, steroids, terpenoids, saponins and phytosterol which are highly effective against pathogenic microorganism. In the present study, various extracts namely ethyl acetate, methanol and benzene extracts of selected plant species i.e. Achyranthes aspera, Azolla pinnata, Cissus quadrangularis and Tinospora cordifolia were studied for its antibacterial activity against Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. The results showed that the plant extracts were specific in action against the growth of bacteria and showed zone of inhibition, but in benzene extract of selected plants there was not any kind of growth of tested microorganism was observed. The highest growth inhibition was found in the ethyl acetate extract of T. cordifolia (30±1.7mm) followed by C. quadrangularis (25±1.3mm), A. aspera (20±0.5mm) and A. pinnata (20±0.9 mm) against S. aureus similarly the methanol extract of T. cordifolia exhibited (25±0.87mm) more antibacterial activity against S. aureus followed by A. aspera (11±0.61mm), C. quadrangularis (10±0.5mm) and A. pinnata (10±0.14mm), whereas methanol and ethyl acetate extract of selected plants also exhibited good antibacterial activity against P. aeruginosa and E. coli. The results of the study indicates that these plants possess phyto-constituents having antibacterial activity thus can be utilized as a natural plant based antimicrobials.