Abstract

During the present investigation, in vitro studies were carried out to evaluate the antibacterial and antifungal activity of two selected plant species viz, Calotropis procera and Citrullus colocynthis. Ethanolic, methanolic and aqueous extracts of leaf were examined for their antibacterial, antifungal activities. Methanolic leaf extracts were found to be more active against gram positive bacteria (Bacillus subtilis: ATCC 6059 and Staphylococcus aureus:ATCC 6538) as well as gram negative bacteria (Pseudomonas aeruginosa: ATCC 7221 andKlebsiella pneumoniae) than water and ethanol extracts of leaves. The leaf extracts from C. colocynthis showed greater inhibitory activity against gram positive and gram negative bacteria as compared to that of C. procera leaf extract. Antifungal activity of the two plant species was performed with both methanolic and aqueous extract against Aspergillus fumigatus. The results revealed that methanolic as well as aqueous extract of C. procerawere found to be most effective in inhibiting the growth of selected fungal strain. It is inferred from the present investigation that the ability of extracts of C. colocynthis and C. procera to inhibit the growth of bacteria and fungi is an indication of their broad spectrum antimicrobial potential which may be implicated in the management of microbial infections.

Key words: Crude extract, aqueous extract, minimum inhibition concentration.