Direct relaxant effect of some plant extracts on isolated tissue models

ABSTRACT

The effects of two different extracts of three medicinal plants namely Piper betle L. (Kun), Coleus aromaticus Benth. (Ziyar-ywet-htu) and Ageratum conyzoides L. (Khway-thay-pan) leaves on the smooth muscles of guinea pig and rat were tested invitro using isolated segments of trachea, intestine and uterus. The extracts inhibited the contractions of guinea pig tracheal muscle induced by carbachol and histamine stimulation. The alcoholic extracts also inhibited the spontaneous movement of huinea pig ileum induced by histamine stimulation. Furthermore, the alcoholic extracts inhibited the contractions of rat uterus induced by 5-HT stimulation. These data suggest that the alcoholic extracts have antihistaminic and anti 5-hydroxytryptamine effects and the active principle may probably resides in the saponin glycoside component.