Study of pharmacological properties of the methanolic extract of Dichrostachys cinerea bark (L.) Wight et Arn (Leguminosae) in isolated myometrium from pregnant rats

Ethnopharmacological relevanceThe use of medicinal plants in Gabon contributes widely to the primary health care of the people of this area of Central Africa. This paper investigates the pharmacological properties of Dichrostachys cinerea, the plant barks are traditionally used by Gabonese and Ivorian populations to treat bronchial asthma, rheumatism, and other various diseases. Although D. cinerea barks have been reported to be used by population to facilitate childbirth, to the best of our knowledge no scientific evidence has been published.Aim of studyIn the present study, we investigated the pharmacological properties of D. cinerea methanolic extract, on isolated uterine smooth muscle and compared its effects to those of oxytocin, which is used by obstetricians to facilitate childbirth. We also explored the possible mechanism pathways of the in vitro uterine contraction induced by D. cinerea.Materials and methodsThe effects of different concentrations (3.2 µg/ml, 16 µg/ml, 80 µg/ml, 400 µg/ml, and 2 mg/ml) of the methanolic extract of D. cinerea on isolated strips of the uteri of pregnant rats were studied. These effects were compared to those of oxytocin (8.4×10–5 µg/ml, 8.4×10–4 µg/ml, 8.4×10–3 µg/ml, 8.4×10–2 µg/ml). The EC (50) and E (max) was determined graphically and statistically analysed using one-way ANOVA and Dunnett post hoc test.ResultsCumulative concentrations of D. cinerea have caused rise in the contractile force of the uterine fragments that were isolated from the pregnant rats, as seen with oxytocin concentrations. We observed contractions amplitude of 30.41 mN (12%) at 80 µg/ml and amplitude of 39.68 mN (14.17%) at 400 µg/ml for D. cinerea. In parallel, oxytocin concentration of 8.4×10–3 µg/ml induced contractions of 45.82 mN with the highest concentration (8.4×10–2 µg/ml) that induced contractions of 55.82 mN.ConclusionsOur results revealed that D. cinerea increased the contractile force and the frequency of muscle contractions. These findings support the use of D. cinerea to facilitate childbirth, as it has been used in traditional medicine.

Graphical abstractThis graphical abstract explains the effect of Dichrostachys cinerea extract on strips from the pregnant rat uteri. The registration A and B shows the contractile strength of the muscle after addition of different concentrations of alcoholic extract from Dichrostachys cinerea. This contraction became stronger with the increase in the concentration of Dichrostachys cinerea from 3.2 µg/ml to 16 µg/ml (A). It is the same for registration (B). At the high concentration of 2 mg/ml, the increase in the force of the contraction of the strips of myometrium was maintained at a stable value. (C) represents the concentration–response sigmoid curve of Dichrostachys cinerea. This graphical representation expresses the evolution of the contractile force as a function of the cumulative concentration applied.Figure optionsDownload full-size imageDownload high-quality image (157 K)Download as PowerPoint slide