Author(s): Oshaghi Mojgan and Sharifi Roya

Abstract: Enteric bacterial pathogens cause various diseases and the major problem of these bacteria is antimicrobial resistance. Silymarin is a standardized extract from the milk thistle clinically has used as a hepatoprotective agent. The aim of this study was to investigate the antibacterial activity of silymarin against enteric bacterial pathogen strains. For evaluation of antibacterial activity, different concentrations of silymarin (ranging from 2-128 μg/mL) were tested against twelve enteric bacterial pathogens by microdilution broth method. The results of study showed that the minimal inhibitory concentration (MIC) of silymarin against all of tested strains was >128 μg/mL. It appears that silymarin is not beneficial drug for treatment of gram negative enteric bacterial pathogens.