Research On Antihypertensive Effect And Mechanism Of The Alcohol Extract Of Cydonia Oblonga Mill.(COM) Leaf In Renal Hypertensive Rats

Objective:To observe the antihypertensive effect and possible mechanism of alcoholextract of Cydonia Oblonga Mill.(COM) leaf in renovascular hypertensive rat (RHR)model.Methods:two-kidney one-clip (2k1c) RHR model was obtained by narrowing leftkidney arteries. RHRs were randomly divided into control group， model group，Captopril group， COM low dosase group， COM medium dosase group and COM highdosase group.Each groups gavaged corresponding drugs for8weeks、once a day. whileadministration the blood pressure of rats was measured by tail cuff approach every twoweeks. After1h last administration， blood was harvested to measure serum superoxidedismutase (SOD) activity， malondialdehyde (MDA)， plasma endothelin (ET) contentand kidney Angiotensin-II (Ang Ⅱ)level; take heart，measure heart weight (HW)/bodyweight (BW) ratio.Results:The determination of blood pressure， alcohol extract ofCOM leaf high、medium dose group were lower than the model group significantly (P<0.05); plasma ET level in alcohol extract of COM leaf high and low dosase group wasdecreased significantly (P <0.05)， and renal Ang-Ⅱ content in alcohol extract of COMleaf each group werey lower significantly than model group(P <0.05); SOD activity inalcohol extract of COM leaf three groups were higher than model group， and MDAcontent lower than model group significantly (P <0.05); Determination (HW)/(BW)ratio， alcohol extract of COM leaf high dosase group lower than the model groupsignificantly (P <0.05).Conclusion:alcohol extract of COM leaf can reduce bloodpressure in RHRs and inhibit heart hypertrophy. Its possible mechanism may be byreducing the level of AngⅡ、ET levels and adjusting the levels of NO and ET to developthe endothelial function.