<i>In vitro</i> response of isolated non-pregnant mouse uterus to the methanol extract of <i>Emilia coccinea</i> (Sims) G. Dons leaf

Abstract

The leaves of Emilia coccinea (Sims) G Dons are used in Southern Nigeria for birth control and in other parts of West Africa for treating female infertility issues. However, no scientific data are available for its effect on uterine contraction. Therefore, this study is aimed at evaluating the effect of the methanol extract of Emilia coccinea leaves on uterine contractility. The cumulative concentrations (0.0004-4.884 mg/ml) of the methanol extract (EM) were tested on rhythmic spontaneous-, oxytocin (OT)-and high potassium chloride (KCl)-induced uterine contractions, OT-induced uterine contractions in calcium-deprived state as well as on OT-induced uterine contractions in the absence and presence of glibenclamide, amiodarone and propranolol. The extract, EM produced significant (P<0.05) decrease in the frequency and amplitude of spontaneous contractions with IC₅₀ of 0.4694±0.07 and I_max of 2.031±0.32, as well as OT (0.1 μg/mL)-induced myometrial contractions and OT-induced contractions in calciumdeprived state containing ethylenediaminetetraacetic acid (EDTA), while it exerted no significant changes on high KCl (80 mM)-induced myometrial contractions. The inhibitory effects of EM were significantly increased (P<0.05) in the presence of glibenclamide (7.5 ng/mL) and propranolol (3.0 ng/mL) while with amiodarone (65.0 ng/mL), EM elicited no observable significant changes in the inhibition of contractions. These observations may explain some of the mechanisms involved in the activity of EM and may explain its folkloric use as birth control, however further studies are advised to characterize and isolate specific bio-constituents responsible for the observed effects.

Keywords: Emilia coccinea; Mouse uterus; Contraception; Oxytocin; Glibenclamide