Spasmolytic activity of methyl angolensate: a triterpenoid isolated from Entandrophragma angolense.

Entandrophragma angolense is a medicinal plant used in folk medicine against several diseases including peptic ulcer. Methyl angolensate was isolated from E. angolense by recrystallization from methanol. The needle-like crystals were characterized and tested on isolated rabbit jejunum, guinea pig ileum and the rat fundus strip. The compound was also evaluated on the gastrointestinal transit in mice. The results showed that the compound exerted significant concentration dependent inhibition of smooth muscle and reduced the propulsive action of the gastrointestinal tract in mice. The relaxation observed did not attenuate acetylcholine and histamine induced contractions, but was found to inhibit contractions induced by serotonin. It is therefore suggested that methyl angolensate may exert its activity on gastrointestinal smooth muscle via serotonergic mechanisms.