<i>In vitro</i> and <i>in vivo</i> Antibacterial Effects of Leaf Extracts of <i>Ocimum sanctum</i> and <i>Argemone mexicana</i>

Abstract

The present study was undertaken to explore the in vitro antibacterial effects of four different leaves extracts of Ocimum sanctum (OS) and Argemone mexicana (AM) against Salmonella enterica serovar Typhimurium and Escherichia coli O26. Besides in vivo antibacterial effects of the hot aqueous extracts (HAE) of OS and AM against the above said enteric pathogens was evaluated in chicken model. In vitro antibacterial activity was determined by disc diffusion and it was concentration dependent. Disc containing 20 mg concentration of all the extracts of OS and AM showed maximum inhibitory effect on the growth of S. enterica serovar Typhimurium and E. coli O26. Among all the extracts methanolic extracts of both the plants had stronger antibacterial activity. On prolonged incubation bacterial colonies reappeared within the zone of inhibition indicating bacteriostatic effect than bactericidal activity. 250 mg/kg body weight oral dose of OS and AM was found ideal and nontoxic in chickens and experimental chickens were fed this dose for 21 days for determination of in vivo antibacterial effect. On 22 nd day respective groups of chickens were challenged orally with ID 50 dose of Salmonella enterica serovar Typhimurium and Escherichia coli. 83% chickens of OS fed groups and 66% chickens of AM fed groups were protected from challenge of S. enterica serovar Typhimurium and E. coli O26. OS provided better clearance of both the pathogens from blood as compared to AM.