Spasmogenic activity and acute toxicity of Yumijangquebo, a herbal laxative formulation.

We evaluated the pharmacological properties and spasmogenic activities of Yumijangquebotrade mark, a Korean herbal laxative formulation. Doses in the range 12-50 microg/ml induced a large spasmogenic effect in isolated guinea pig ileum, similar to that induced by acetylcholine. Pre-treating the tissue with atropine (0.2 microM) completely abolished the contractile effect of Yumijangquebo. The spasmogenic effect of Yumijangquebo and the inhibition of this effect by atropine suggest that a cholinergic mechanism is responsible for its effects. Yumijangquebo increased the gastrointestinal motility in ICR mice at doses between 10 and 37 mg/kg. Yumijangquebo exhibited higher activity than three other laxatives tested, which had activities about 85% of that of Yumijangquebo. In an acute toxicity study using Sprague-Dawley rats, the median lethal dose (LD50) of Yumijangquebo was greater than 2000 mg/kg, and we found no pathological changes in macroscopic examination by necropsy of rats treated with Yumijangquebo. We conclude that Yumijangquebo may be safely used as a herbal spasmogenic laxative agent.