Author(s): Nidhi Srivastava*, Anup Kainthola and A.B. Bhatt

Abstract: The present study is focused to evaluate the antimicrobial efficacy ofZanthoxylum armatum DC. (Rutaceae) against four different microorganisms viz Staphylococcus aureus, Escherichia coli, Proteus vulgaris andPseudomonas aeruginosa.Z. armatum is extensively used in indigenous system of medicine as a tonic, carminative, stomachic and antihelmintic. Present investigation is an attempt to reveal the antibacterial activity of the chloroform, methanol and acetone extracts of Z. armatum barkusing the well diffusion method against four different bacterial strains. Highest ZOI was observed in acetone extract against S. aureus (42.3 mm) followed by methanolic extract against S. aureus (28.7mm) while highest chloroform extract against were found P .vulgaris (28.3 mm). Overall the methanol and acetone extract of bark was found to be more effective for S. aureus and chloroform extract for P. vulgaris. The results of the extracts were compared with the standard antibiotics.