Introduction The costly cost of treatments for cardiovascular diseases, in particular for populations in developing countries such as Senegal, requires an alternative which consists in developing research into new therapeutic approaches with the use of plants from the traditional pharmacopoeia. On the other hand, many of these plants have not been the subject of scientific studies. Goal In our study, we set out to study the effects on the vasomotricity of a plant from an in vitro model. As specific objectives, research of the vasorelaxant effects of the hydro-ethanolic extract of the leaves of Oxytenanthera abyssinica, on a model of pig coronary artery. Materials and method The coronary artery rings were incubated with Oxytenanthera abyssinica (FOA) leaf extract at different concentrations (10-4mg / ml 5.10-4mg / ml 10-3mg / ml 5.10-3mg / ml 10- 2mg / ml 5.10-2mg / ml, 10-1mg / ml and 5.10-1 mg / ml) in an isolated organ system. The device comprises a set of devices including isometric tension sensors. The vessel rings to be studied are mounted on these. They are connected to metal rods that develop isometric tension. These sensors make it possible to measure the intensity of the voltage developed which reflects the vascular reactivity. After incubation, the rings are contracted with U46619 to produce a concentration –contraction curve with and without endothelium. The measured voltages are collected and represented in the form of a curve using the Graph Pad software. Prism version 6.01®. The results are expressed as means ± SEM of 08 experiments. The analysis of variance test (ANOVA) was used to compare the means. The values of p <0.05 were considered significant. Results The results obtained in this study showed that on isolated pig coronary artery rings, contracted at U46619, the hydro-ethanolic extract of Oxytenanthera abyssinica (FOA) leaves induces vascular relaxation. This vasorelaxation is obtained at concentrations ranging from 10-4 to 5.10-1 mg / ml with a relaxation percentage of approximately 100%. This percentage of relaxation is obtained both in the presence and in the absence of functional endothelium. These results suggest that the hydro-ethanolic extract of leaves of Oxytenanthera abyssinica possesses dose-dependent vasodilator properties on isolated pig coronary artery rings with endothelium-independent character. It thus appears that the raw extract of leaves of Oxytenanthera abyssinica can act on two ways: Conclusion The results of our study made it possible to demonstrate a vascular relaxing effect of the hydro-ethanolic extract of the leaves of Oxytenanthera abyssinica. This vasorelaxant effect is dose-dependent and endothelium-independent.

Keywords: Oxytenanthera abyssinica, coronary arteries, vasorelaxant