Study of antihypertensive activity of Elaeocarpus ganitrus water extract in renal artery-occluded hypertensive rats

The water extract of Elaeocarpus ganitrus seeds (EGW) (Elaeocarpaceae) was studied for its antihypertensive activity in renal artery-occluded hypertensive rats. The extract was prepared by macerating the seeds powder in distilled water for 24 hours. It was further dried in hot plate evaporator at 50–55⁰C. Preliminary phytochemical study of extract showed the presence of alkaloids, flavanoids and tannins. The dried EGW was administered orally to male Albino Wistar rats at three different doses viz. 250, 500 and 1000mg/kg for six weeks. At the day of experiment, hypertension in anaesthetized rats was induced by the occlusion of renal artery for 4h. The carotid artery was connected to blood pressure transducer of Power Lab eight channel recorder to measure the blood pressure. Jugular vein was also cannulated for administration of the test compound. After obtaining stable blood pressure values, the renal arterial clip was removed and the Mean arterial blood pressure (MABP) was measured. MABP of animals in control group was measured without renal artery ligation. Then 1/10^th of dose of test substance was administered by intravenous injection to experimental rats and MABP was measured. Captopril, an angiotensin converting enzyme inhibitor (ACE-I) was used as a positive control at the dose of 1mg/kg i.v. The results showed that the EGW significantly decreased the elevated blood pressure in dose dependent manner comparable to positive control, captopril. One-way ANOVA followed by Dunnett's test was applied to test statistical significance. The study thus corroborates the antihypertensive activity of EGW through renin angiotensin system.