Studies on the activity of Cyperus rotundus Linn. tubers against infectious diarrhea.

To study the antidiarrheal activity of the decoction of Cyperus rotundus Linn. tubers using representative assays of diarrheal pathogenesis and understand its mechanism of action.Antibacterial, antigiardial and antirotaviral activities were studied. Effect on adherence of enteropathogenic Escherichia coli (EPEC) and invasion of enteroinvasive E. coli (EIEC) and Shigella flexneri to HEp-2 cells was evaluated as a measure of effect on colonization. Effect on enterotoxins such as enterotoxigenic E. coli (ETEC) heat labile toxin (LT), heat stable toxin (ST) and cholera toxin (CT) was also assessed. The decoction showed antigiardial activity, reduced bacterial adherence to and invasion of HEp-2 cells and affected production of CT and action of LT. The decoction of C. rotundus does not have marked antimicrobial activity and exerts its antidiarrheal action by mechanisms other than direct killing of the pathogen.