Pharmacological Actions of the Leaves ofSolenostemma argel(Hayne): Spasmolytic and Uterine Relaxant Activities

Abstract

The effects of the chloroform-methanol (CM) (1:IV/V) and the chloroform (C) extracts of Solenostemma argel leaves were examined on the spontaneously contracting rabbit jejunum and rat uterus. CM (400 μg/ml) produced a biphasic effect on the rabbit jejunum: an initial reversible inhibition followed by delayed and sustained inhibition. The inhibitions were not antagonized by haloperidol, propranolol or guanethidine. MC also suppressed the activity of the uterus and the effect was not antagonized by cimetidine, haloperidol, or propranolol. Furthermore, MC exhibited a local anaesthetic activity when tested on the foot withdrawal reflex of the frog. The C extract stimulated the uterus. This effect was antagonized by atropine or cyproheptadine. It was concluded that the inhibitory activity may be due to presence of local anaesthetic components whereas the stimulant effect may be due to activation of muscarinic and/or serotonergic uterine receptors.