Epigallocatechin-3-gallate exerts antihypertensive effects and improves endothelial function in spontaneously hypertensive rats  

作　　者：Yucinda YY Khor Siew-Keah Lee Dharmani Devi M Wei Chih Ling 

机构地区：[1]Department of Pre-clinical Sciences,M.Kandiah Faculty of Medicine and Health Sciences,Universiti Tunku Abdul Rahman,Selangor,Malaysia [2]Department of Pharmacology,Faculty of Medicine,Universiti Malaya,Kuala Lumpur,Malaysia

出　　处：《Asian Pacific Journal of Tropical Biomedicine》2023年第7期287-295,共9页亚太热带生物医学杂志（英文版）

基　　金：funded by the Universiti Tunku Abdul Rahman Research fund(IPSR/RMC/UTARRF/2019-C2/L08)。

摘　　要：Objective:To investigate the effect of epigallocatechin-3-gallate(EGCG)on endothelial dysfunction in spontaneously hypertensive rats(SHR).Methods:Wistar-Kyoto(WKY)rats and SHR were divided into four groups;WKY control,SHR control and SHR treated with EGCG(50 mg/kg/day)or losartan(10 mg/kg/day).The treatment was given daily for 4 weeks by oral gavage and the blood pressure was monitored by tail-cuff method every 3 days.Acetylcholineinduced endothelium-dependent relaxations were assessed in isolated phenylephrine-precontracted aortic rings at the end of treatment.The vascular levels of reactive oxygen species,nitric oxide,tetrahydrobiopterin,and cyclic guanosine monophosphate were also measured.Moreover,the expression of angiotensinⅡtype 1(AT_(1))receptor protein was determined.Results:The systolic blood pressure was significantly decreased in SHR treated with EGCG.The impaired endothelium-dependent relaxation was significantly improved in aortic ring isolated from the EGCG-treated SHR group.EGCG also significantly increased the levels of nitric oxide,tetrahydrobiopterin,and cyclic guanosine monophosphate,while decreasing the level of reactive oxygen species and the protein expression of AT_(1)receptor in SHR.Conclusions:EGCG attenuates endothelial dysfunction in SHR by decreasing oxidative stress and increasing vascular nitric oxide bioavailability,which may be modulated partly by inhibition of vascular AT_(1)receptors.An increase in endothelium-dependent relaxation may contribute to a decrease in blood pressure in hypertensive animals.

关 键 词：Epigallocatechin-3-gallate Vascular protection ANTIHYPERTENSION TETRAHYDROBIOPTERIN Cyclic guanosine monophosphate Angiotensin typeⅠreceptor Spontaneously hypertensive rats 

分 类 号：R544.1[医药卫生—心血管疾病]