How do Spondias mombin L (Anacardiaceae) leaves extract increase uterine smooth muscle contractions to facilitate child birth in parturient women?

Abstract

Background: Spondias mombin L. (Anacardiaceae) leaves were used in Togolese folk to treat dystocia, expel placenta and manage post-partum hemorrhage during child birth.

Objectives: This study aimed to establish how the extract of S. mombin leaves increase uterine smooth muscle contractions relevant to its traditional use to facilitate child birth.

Methods: Tests were performed on uterus muscle strips from Sprague-Dawley rats. Central portion of uterine horns were dissected, cleaned of surrounding fat and loose connective tissue, and cut longitudinally into strips which were placed in the organ bath for isometric tension record in presence of different substances.

Results: S. mombin leaves extract increased uterine spontaneous contractions. This effect was reduced by indomethacin (2 × 10-6 M), yohimbine (2 × 10-6 M) and 2-aminoethoxydiphenyl borate (2-APB) (5 × 10-5 M), but not by atropine (3.45 × 10-8 M) and cholesterol (2.5 mg/ml).

Conclusion: The pharmacological justification for the traditional use of S. mombin leaves to treat dystocia and expel placenta was that its hydro-ethanolic extract induced prostaglandins release, α2-adrenoceptors stimulation, calcium release from internal stores and lifted inhibitory effect of cholesterol on uterine contractions in order to increase uterine smooth muscle contractions.

Keywords: Spondias mombin; calcium; contractions; uterus.

Figure 1

Inhibitory effect of indomethacin on uterus smooth muscle contractions induced by the extract. Values are given as means ± S.E.M. (n = 5) *p < 0.05 (ANOVA followed by Dunnett). Arrow show the time of extract or indomethacin addition to the organ bath followed by the wash out.

Figure 2

Inhibitory effect of yohimbine on uterus smooth muscle contractions induced by the extract. Values are given as means ± S.E.M. (n = 5) *p < 0.05 (ANOVA followed by Dunnett). Arrow show the time of extract or yohimbine addition to the organ bath followed by the wash out.

Figure 3

Inhibitory effect of 2-APB on uterus smooth muscle contractions induced by the extract. Arrow show the time of extract or calcium free / EDTA solution or 2-APB addition to the organ bath followed by the

Figure 4

Ineffective effect of atropine on uterus smooth muscle contractions induced by the extract. Values are given as means ± S.E.M. (n = 4) *p < 0.05 (ANOVA followed by Dunnett). Arrow show the time of atropine or extract addition.

Figure 5

Cholesterol inhibits uterine spontaneous contractions (A) and the extract lifts the inhibitory effect of cholesterol on uterus smooth muscle contractions (B). Arrow show the time of cholesterol or extract addition.