BROMELAIN PREVENTS SECRETION CAUSED BY VIBRIO-CHOLERAE AND ESCHERICHIA-COLI ENTEROTOXINS IN RABBIT ILEUM IN-VITRO

Background & Aims: Diarrhea is a major cause of illness and death in c hildren and young animals. The aim of this study was to investigate th e possible therapeutic effect of bromelain, a proteolytic extract obta ined from pineapple stems on bacterial toxin and second-messenger agon ist-induced intestinal secretion, Methods: The effect of bromelain pre treatment on short-circuit responses to Escherichia coli heat-labile e nterotoxin, heat-stable enterotoxin, and Vibrio cholerae cholera toxin was evaluated in rabbit ileum mounted in Ussing chambers. Results: Br omelain was 62% effective in preventing heat-stable enterotoxin-induce d secretion, 51% effective against cholera toxin, and 35% effective ag ainst heat-labile enterotoxin, Bromelain also prevented secretory chan ges caused by prostaglandin E-2, theophylline, calcium-ionophore A2318 7, 8-bromoadenosine 3':5'-cyclic monophosphate, and 3-bromoguanosine 3 ':5'-cyclic monophosphate, well-known intracellular mediators of ion s ecretion. The efficacy of bromelain was not caused by reduced tissue v iability resulting from its proteolytic effects on enterocytes, indica ted by experiments measuring uptakes of nutrients into intestinal cell s and experiments measuring short-circuit responses to glucose. Conclu sions: Bromelain prevents intestinal fluid secretion mediated by secre tagogues that act via adenosine 3':5'-cyclic monophosphate, guanosine 3':5'-cyclic monophosphate, and calcium-dependent signaling cascades. It may be clinically useful as an antidiarrheal drug.