Effects of dehydroeffusol on spasmogen-induced contractile responses of rat intestinal smooth muscles.

Dehydroeffusol is a naturally occurring phenanthrene isolated from Juncus effusus. In the context of screening new drugs against gastrointestinal spasms, we investigated its effects on isolated rat jejunum in vitro. Dehydroeffusol (30-90 µM) slightly and transiently enhanced contractions in a concentration-dependent manner but significantly inhibited the contractions induced by KCl (100 mM), (±)-Bay-K8644 (5 µM), pilocarpine (90 µM), and histamine (100 µM). These results show that dehydroeffusol may antagonize the spasmogenic activity of various agents, and therefore, could be a promising agent in the treatment of spasms. Its potential spasmolytic mechanism is also discussed.