Department of Animal Biology and Physiology, University of Douala, Douala, Cameroon.
BMC Complement Altern Med. 2013 Jan 31;13:27. doi: 10.1186/1472-6882-13-27.
Previous study showed that the aqueous extract of the stem bark of Cinnamomum zeylanicum possesses antihypertensive and vasodilatory properties. The present work investigates the acute and chronic antihypertensive effects of the methanol extract of Cinnamomum zeylanicum stem bark (MECZ) in L-NAME-induced hypertensive rats.
The acute antihypertensive effects of MECZ (5, 10 and 20 mg/kg) administered intravenously were evaluated in rats in which acute arterial hypertension has been induced by intravenous administration of L-NAME (20 mg/kg). For chronic antihypertensive effects, animals were treated with L-NAME (40 mg/kg/day) plus the vehicle or L-NAME (40 mg/kg/day) in combination with captopril (20 mg/kg/day) or MECZ (300 mg/kg/day) and compared with control group receiving only distilled water. All drugs were administered per os and at the end of the experiment that lasted for four consecutive weeks, blood pressure was measured by invasive method and blood samples were collected for the determination of the lipid profile. The heart and aorta were collected, weighed and used for both histological analysis and determination of NO tissue content.
Acute intravenous administration of C. zeylanicum extract (5, 10 and 20 mg/kg) to L-NAME-induced hypertensive rats provoked a long-lasting decrease in blood pressure. Mean arterial blood pressure decreased by 12.5%, 26.6% and 30.6% at the doses of 5, 10 and 20 mg/kg, respectively. In chronic administration, MECZ and captopril significantly prevented the increase in blood pressure and organs' weights, as well as tissue histological damages and were able to reverse the depletion in NO tissue's concentration. The MECZ also significantly lower the plasma level of triglycerides (38.1%), total cholesterol (32.1%) and LDL-cholesterol (75.3%) while increasing that of HDL-cholesterol (58.4%) with a significant low atherogenic index (1.4 versus 5.3 for L-NAME group).
MECZ possesses antihypertensive and organ protective effects that may result from its ability to increase the production of the endogenous NO and/or to regulate dyslipidemia.
先前的研究表明，肉桂的茎皮水提物具有降压和血管舒张作用。本工作研究了肉桂甲醇提取物（MECZ）对 L-NAME 诱导的高血压大鼠的急性和慢性降压作用。
通过静脉内给予 L-NAME（20mg/kg），评估 MECZ（5、10 和 20mg/kg）静脉内给药的急性降压作用。对于慢性降压作用，用 L-NAME（40mg/kg/天）加载体或 L-NAME（40mg/kg/天）与卡托普利（20mg/kg/天）或 MECZ（300mg/kg/天）联合治疗，并与仅接受蒸馏水的对照组进行比较。所有药物均口服给药，在为期四周的实验结束时，通过有创法测量血压，并采集血液样本测定血脂谱。收集心脏和主动脉，称重并用于组织学分析和测定 NO 组织含量。
急性静脉内给予肉桂提取物（5、10 和 20mg/kg）至 L-NAME 诱导的高血压大鼠，可引起血压的长时间降低。在 5、10 和 20mg/kg 剂量下，平均动脉压分别降低 12.5%、26.6%和 30.6%。在慢性给药中，MECZ 和卡托普利可显著预防血压和器官重量的增加，以及组织学损伤，并能逆转 NO 组织浓度的耗竭。MECZ 还可显著降低血浆甘油三酯水平（38.1%）、总胆固醇水平（32.1%）和 LDL-胆固醇水平（75.3%），同时增加 HDL-胆固醇水平（58.4%），使致动脉粥样硬化指数显著降低（1.4 对 L-NAME 组的 5.3）。
MECZ 具有降压和器官保护作用，这可能是由于其增加内源性 NO 产生和/或调节血脂异常的能力所致。
