Gastrointestinal Effects of Allamanda cathartica Leaf Extracts

Abstract
An aqueous extract of the leaves of Allamanda cathartica was screened for gastrointestinal effects. The extract induced dose-related purgation in mice, as judged by an increased number of wet feces in the extract-treated rats. In addition, the extract enhanced the propulsive movement of intestinal contents. On the isolated ileum of guinea pig, the extract induced dose-related contractions that were insensitive to hexamethonium. mepyramine and methysergide, but were blocked by atropine. Phytochemical tests revealed the main constituents as alkaloids, flavonoids, saponins and carbohydrates. These findings suggest that the aqueous extract of the leaves of A. cathartica might elicit a purgative effect by increasing intestinal motility. partly via muscarinic receptor activation.