Antidiarrhoeal activity of bisnordihydrotoxiferine isolated from the root bark of Strychnos trinervis (Vell.) Mart. (Loganiaceae).

Bisnordihydrotoxiferine, a dimeric tertiary indole alkaloid obtained from the root bark of Strychnos trinervis (Vell.) Mart. (Loganiaceae), inhibited normal defaecation and castor oil, arachidonic acid, and magnesium sulphate-induced diarrhoea on intraperitoneal administration in mice. The effect may be related to the ability of the compound to decrease normal and castor oil-stimulated gastric emptying, small intestinal transit and water and electrolyte accumulation, and inhibition of normal colonic transit. As prostaglandins are involved in gastrointestinal functions, inhibition of their synthesis is likely to contribute to the anticathartic activity, which has never been reported before for an indole alkaloid.