Cardioprotective effect of hydroalcoholic extract stem bark ofon cadmium chloride-induced hypertension and its possible vasorelaxant mechanism on isolated aortic rats.

Abstract

BACKGROUND: is a medicinal plant, widely used in Cameroonian folk medicine to treat hypertension. OBJECTIVE: This study aimed to investigate the beneficial effect ofin hypertensive rats and to explore the vasorelaxant mechanisms of its hydroalcoholic extract and to determine the compounds responsible of the activities. MATERIALS AND METHODS: Hydroalcoholic extract, fractions, subfractions and isolated compounds were screened for the antihypertensive activity in Wistar rat of either sex using a noninvasive method to record blood pressure (BP) and heart rate (HR). At the end of the treatment, the level of nitrite in the tissues and the histological analysis of the heart and aorta were determined. Vasorelaxant activity of the plant was carried out, on the contractile responses of aortic rings induced by phenylephrine (10M) or KCl (60 mM). Mechanisms involved vasorelaxation effect ofwere assessed using various antagonists. RESULTS: Treatment of Cadmium-hypertensive rats with extract significantly (˂ 0.001) reduced BP and HR, improved nitrite level, ameliorated heart and aorta alterations. Moreover, the hydroalcoholic extract, fractions, subfraction and odoratin-induced vasorelaxant effect. The preincubation with N-nitro-L-arginine methyl ester, methylene blue and tetraethylammonium partially inhibited hydroalcoholic extract/fraction-induced relaxation. The extract completely inhibited the effects on CaCl-induced contracted rings and reduced the contraction induced by phenylephrine in a Ca-free solution. CONCLUSION: These results support the traditional use ofin the treatment of hypertension. This effect may be due in part to the plant's vasorelaxant activity and the presence of compounds such as phenol in plant extracts.