Antidiarrheal activity of wood creosote: inhibition of muscle contraction and enterotoxin-induced fluid secretion in rabbit small intestine.

Wood creosote has long been used as an antidiarrheal agent, but its mechanism of action is not well understood. To elucidate the mechanism of its antidiarrheal activity, we have addressed questions whether it inhibits fluid secretion induced by Escherichia coli heat-stable enterotoxin (STa) in rabbit jejunum in vivo, and whether it inhibits muscle contraction of isolated rabbit ileum ex vivo. Wood creosote (10-100 mg/l) instilled in a ligated loop of jejunum inhibited STa-induced fluid secretion (p < 0.05). It also inhibited the spontaneous phasic, acetylcholine-induced tonic and Ba2+-induced tonic contractions of longitudinal and circular muscles of ileum dose-dependently with IC(50) values of 130-530 mg/l. These data provide further evidence that the antidiarrheal activity of wood creosote is attributable to its antisecretory and antimotility effects.