Tl. Mynott et al., BROMELAIN PREVENTS SECRETION CAUSED BY VIBRIO-CHOLERAE AND ESCHERICHIA-COLI ENTEROTOXINS IN RABBIT ILEUM IN-VITRO, Gastroenterology, 113(1), 1997, pp. 175-184
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.