Pharmacological investigation of Haplophyllum tuberculum

The effect of a 20% (w/v) aqueous extract of H. tuberculatum aerial parts was studied on isolated rabbit jejunum, guinea-pig ileum, rat uterus, rat stomach strip and rat colon. The extract (1.6 ml/25 ml-bath≃76.6mg of starting material) produced a biphasic effect on both jejunum and ileum; an initial reversible stimulation, followed by sustained inhibition. The stimulant effect was blocked by atropine and the inhibition was resistant to a number of standard receptor blockers. The extract also stimulated uterus, fundus strip and colon. Cyproheptadine blocked effects on uterus and fundus strip, while indomethacin largely reduced the activity on the colon