Modulation of ex-vivo uterine contraction by the methanol leaf extract of Alchornea laxiflora Benth. (Euphorbiaceae) and preliminary spectrometric identification of associated secondary metabolites

Enitome E Bafor,Buniyamin Ayinde,Ruangelie Edrada-Ebel,Uloma B Elvis-Offiah,Josephine Ofeimun,Fabian Amaechina,Osemelomen Omoruyi,Christina Viegelmann,Juliet K Nwogu

doi:10.4102/jomped.v2i1.33

Abstract

Background: The leaves of Alchornea laxiflora are traditionally used in the south of Nigeria to prevent preterm births. Aim: This study was designed to investigate the activity of A. laxiflora on uterine contractility. Setting: The leaves of the plant were collected from forests in Egor, Benin City, Nigeria. Methods: The leaves were cleaned and extracted in methanol. The extract (0.005 mg/mL–3.5 mg/mL) was tested on spontaneous uterine contraction and on oxytocin-induced contraction in normal and Ca2+-free media. The plant extract (0.0035 mg/mL, 0.035 mg/mL, 0.35 mg/mL and 3.5 mg/mL) was tested on high KCl-induced uterine contractions (80 mM). The plant extract (3.5 mg/mL) was also studied in the presence of amiodarone and glibenclamide in separate experiments. Mass spectrometric analysis was additionally performed on the plant extract in order to identify significant secondary metabolites that may have contributed to the activity of the plant. Results: The plant extract inhibited spontaneous, oxytocin and high KCl-induced uterine contractions and also significantly inhibited (p < 0.01) oxytocin-induced uterine contraction in Ca2+-free medium. The plant extract significantly inhibited (p < 0.01 and p < 0.05) oxytocin’s amplitude in the presence of amiodarone and glibenclamide, respectively. Secondary metabolites belonging to classes of fatty acids, glycols, terpenes, flavonoid glycosides and porphyrins were identified. Conclusion: Alchornea laxiflora inhibited mouse uterine contractility possibly through interaction with potassium and calcium channels. Of the known metabolites identified, 3-deoxy-arabino-hept-2-ulosonic acid, 17-hydroxyingenol and phaeophorbide-a methyl inhibit uterine contractility and may contribute to the activity of A. laxiflora in utero.

Highlights

Uterine contractions are involved in preterm labour (PTL) and dysmenorrhoea
The relative prevalence of the cell type was used to ascertain the oestrus phase for each recipient mouse
It has been shown that an increase in frequency of uterine contractions occurs during the follicular phase followed by a decrease during the luteal phase of the menstrual cycle (Bulletti et al 1993; Lyons et al 1991)

Summary

Introduction

Uterine contractions are involved in preterm labour (PTL) and dysmenorrhoea. Preterm labour, which leads to preterm births (PTBs), is a major cause of perinatal mortality and morbidity (Goldenberg 2002; Goldenberg et al 2008). Preterm birth originates from premature uterine contractions and is still one of the major obstetrical problems (Maltaris et al 2006). Several drugs have been used as tocolytics and they include β-adrenoceptor mimetics, calcium antagonists, prostaglandin (PG) inhibitors and alcohol (Keirse 2003). Use of tocolytics is an important intervention as it enables delivery to be delayed long enough for transfer of the mother to a specialist tertiary centre or for corticosteroids to be administered to the mother which promotes maturation of foetal lung (Goldenberg 2002). The leaves of Alchornea laxiflora are traditionally used in the south of Nigeria to prevent preterm births

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