In vivo and in vitro hypotensive effect of aqueous extract of Moringa stenopetala

Background: Moringa stenopetala , Baker f. (Moringaceae) is used for food and medicine in Southern Ethiopia. Objective: To substantiate the hypotensive effect of M. stenopetala in vivo and in vitro. Methods: An in vivo experiment was carried out on male guinea pigs anaesthetized with pentobarbital. The arterial blood pressure was recorded from a carotid artery filled with heparinized saline via an arterial cannula connected to a pressure transducer. For the in vitro experiment the descending thoracic aorta was removed and kept moistened in Krebs-Henseleit solution and then mounted in a 20ml tissue bath maintained at 370C and bubbled with a mixture of 95% oxygen and 5% carbon dioxide. Results: Crude aqueous leaf extract of M. stenopetala caused significant fall in systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial blood pressure (MABP) at doses of 10, 20, 30 and 40 mg/kg in normotensive anaesthetized guinea pigs (n = 12). The effect might have been mediated by non-autonomic nervous system as the effect is not altered by atropine and propranolol. The extract also caused significant dose and time dependent inhibition of K+ induced contraction on guinea pig aorta. Conclusion: M.stenopetala has blood pressure lowering effect substantiating the use of the plant in traditional medicine