The Effect of Gallotannins and (+)-Catechin on the Stimulated Fluid Secretion on the Colon, Following a Rhein Perfusion in Guinea Pigs¹

Abstract

Using 9smTcEDTA as a non-absorbable volume marker, perfusion experiments on guinea pigs colon revealed the secretagogue effect of 0.7mM rhein solution (circulating water increase x = +2.8 ml/ hour, SD 0.6 ml, N = 10). After omission of rhein, gallotannins in a 0.1 % concentration effectively inclined the stimulated secretion, into absorption (x = -2.0 mI/hour, SD 0.4 nil, N = 4). Catechin (0.1%) had no marked effect. If a perfusion with tn-or pentagalloylglucose is preceding a rhein perfusion, the secretagogue effect of rhein is antagonised, although no absorption was detected. Catechin showed no activity. The addition of tn-or pentagalloylglucose to a rhein containing perfusatc inclines significantly the observed secretion.

Proanthocyanidins and tannin-like compounds - nature, occurrence, dietary intake and effects on nutrition and health

“…Such an adsorption of PAs on the gut mucosa is probably at the origin of the use of tannic acid in barium enema for colon examination 169. Other mechanisms that may explain the antidiarrhoeal effects of tannins are the complexation of secretagogue compounds such as cholera toxin170 and rhein171 or the inhibition of intestinal motility 172…”

Potentilla—A review of its phytochemical and pharmacological profile

“…The antidiarrhoeal effect of tannins is commonly attributed to the unspecific complexation of mucosal proteins in the gut with formation of a protective layer. The antidiarrhoeal effects of tannins may therefore be explained by the complexation of secre- Kolpakov et al (2001) togogue compounds such as cholera toxin (Hör et al, 1995), rhein (Verhaeren and Lemli, 1986) or the inhibition of intestinal motility (Galvez et al, 1991).…”