Effect of methanolic extract of Asparagus pubescens root on non-vascular smooth muscle in experimental animals

Abstract

The effect of methanolic extract of Asparagus pubescens root was investigated on non-vascular smooth muscle in experimental animals. The extract dose-dependently reduced spontaneous rhythmic contraction of rat uterine smooth muscle. It also inhibited acetylcholine, ergometrine, oxytocin, prostaglandin E2, 5-hydroxytryptamine as well as nicotine-induced contractions on rat uterine muscle.
These dose-related inhibitions were statistically significant (p < 0.01). The effects of standard agonists (barium chloride, BaCl2; potassium chloride, KCl; and acetylcholine, Ach) were also examined on extract pretreated rabbit jejunum and fallopian tube. This effect was potentiated (except KCl) in Day-10 on pretreated rabbit jejunum. On Day-20, a marked inhibition was recorded in all the agonists and on Day-30, recovery was established. Similar effects were recorded with extract pretreated rabbit fallopian tube muscle with Ach and oxytocin. However, effect of ergometrine was not potentiated in Day-10. The extract also showed dose-dependent inhibition on BaCl2-, Ach- and histamine-induced contractions on guinea ileum as well as adenosine triphosphate (ATP) and Ach-induced contractions on urinary bladder. The non-selective inhibition of the agonists by the extract on non-vascular smooth muscle may in part be related to its non-specific mechanism of action.


Keywords: Asparagus pubescens, non-vascular smooth muscle, methanolic extract, non-specific mechanism

West African Journal of Pharmacology and Drug Research Vol. 21 (1&2) 2005: pp. 31-36