Ethyl acetate and aqueous fractions of Ziziphus jujuba prevent acute hypertension induced by angiotensin II in rats.

BACKGROUND Antihypertensive effect of Ziziphus jujube (ZJ) has been reported previously. OBJECTIVE The present study investigates the effect of two ethyl acetate (polar and semi-polar compound) and aqueous fractions (polar compound) of ZJ on cardiovascular parameters in acute hypertension induced by angiotensin II(AngII). METHODS Rats randomly were divided into as following groups (n=7 in each group): Control, AngII (50 ng/kg), Losartan (Los, 30 mg/kg) + AngII, ethyl acetate fraction (EA150 and EA300 mg/kg) + AngII and aqueous fraction (A150 and A300 mg/kg) + AngII. Treated rats received Los and ZJ fractions for four weeks orally and in experiment day (28th) received AngII intravenously. In all groups' systolic blood pressure (SBP), heart rate (HR) and mean arterial pressure (MAP) were recorded throughout the experiment after cannulation of femoral artery via power lab system. RESULTS In AngII group SBP and MAP significantly increased (P<0.001) and HR decreased compared to the control. The SBP and MAP in both doses (150 and 300 mg/kg) of two fractions significantly were reduced in comparison with the AngII group (P<0.05, P<0.001, respectively). Bradycardia induced by AngII also decreased so was not significant than control. Comparison the effects of two fractions revealed that both fractions reduced cardiovascular responses induced by AngII but ethyl acetate is more effective than aqueous fraction. CONCLUSION This study indicates that the both fractions of the ZJ extract have beneficial effect on AngII hypertensive in rat. Because the most compounds of two fractions are polar, we suggested that antihypertensive effects of ZJ is mediated by polar compounds.