en پژوهشي Research Article The aim of the present research was focused on the antibacterial, preliminary phytochemical and pharmacognostical properties of Vicoa indica (L.)DC. via in vitro approach. The aqueous and organic solvent (hexane, chloroform and methanol) extracts from the leaves of Vicoa indica (Asteraceae) were tested against Escherichia coli, Klebsiella pneumoniae, Salmonella typhi, Vibrio parahaemolyticus, Vibrio cholerae, Bacillus subtilis and Streptococcus pneumoniae by agar cup plate method. The results showed promising antibacterial activity against the bacteria tested. Among these, hexane and aqueous extracts were found to have a potent inhibitory effect compared to the other extracts. Hexane and aqueous extracts showed several degrees of antibacterial properties against E. coli, K. pneumoniae and S. typhi . The chloroform extract showed the maximum zone of inhibition against K. pneumoniae, E. coli, S. pneumoniae, S. typhi and B. subtilis, establishing effectiveness of this drug for the treatment of infectious diseases. The methanol extracts exhibited excellent activity against E. coli , K. pneumoniae and Vibrio parahaemolyticus , which prove the potentiality of the plant extract for the treatment of various infections. This study includes preliminary phytochemical and pharmacognostic investigations on the taxon. 109 0 http://ijpt.iums.ac.ir/browse.php?a_code=A-10-100-113&slc_lang=en&sid=1 Kesavan - Srinivasan 1003194753284600351 1003194753284600351 No Devarajan -- Natarajan 1003194753284600352 1003194753284600352 No Chokkalingam -- Mohanasundari 1003194753284600353 1003194753284600353 No Chinthambi -- Venkatakrishnan 1003194753284600354 1003194753284600354 No Nandakumar -- Nagamurugan 1003194753284600355 1003194753284600355 No