School of Health and Biomedical Science, RMIT University, Bundoora, VIC 3083, Australia.
School of Health, Medical and Applied Sciences, CQUniversity Australia, Rockhampton, QLD 4071, Australia.
Molecules. 2018 Jun 22;23(7):1511. doi: 10.3390/molecules23071511.
(−)-Epicatechin (E) is a flavanol found in green tea and cocoa and has been shown to attenuate tumour necrosis factor alpha (TNF-α)-mediated inflammation, improve nitric oxide levels, promote endothelial nitric oxide synthase (eNOS) activation and inhibit NADPH oxidase. This study investigated the effect of 28 days of low epicatechin dosing (1 mg/kg/day) on the cardiovascular function of deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Wistar rats (n = 120, 8 weeks of age) underwent uninephrectomy and were randomised into four groups (uninephrectomy (UNX), UNX + E, DOCA, DOCA + E). DOCA and DOCA + E rats received 1% NaCl drinking water along with subcutaneous injections of 25 mg deoxycorticosterone-acetate (in 0.4 mL of dimethylformamide) every fourth day. UNX + E and DOCA + E rats received 1 mg/kg/day of epicatechin by oral gavage. Single-cell micro-electrode electrophysiology, Langendorff isolated-heart assessment and isolated aorta and mesenteric organ baths were used to assess cardiovascular parameters. Serum malondialdehyde concentration was used as a marker of oxidative stress. Myocardial stiffness was increased and left ventricular compliance significantly diminished in the DOCA control group, and these changes were attenuated by epicatechin treatment ( < 0.05). Additionally, the DOCA + E rats showed significantly reduced blood pressure and malondialdehyde concentrations; however, there was no improvement in left ventricular hypertrophy, electrophysiology or vascular function. This study demonstrates the ability of epicatechin to reduce blood pressure, prevent myocardial stiffening and preserve cardiac compliance in hypertrophied DOCA-salt rat hearts.
（−）-表儿茶素（E）是一种存在于绿茶和可可中的黄烷醇，已被证明可减轻肿瘤坏死因子α（TNF-α）介导的炎症，提高一氧化氮水平，促进内皮型一氧化氮合酶（eNOS）的激活，并抑制 NADPH 氧化酶。本研究调查了 28 天低表儿茶素剂量（1mg/kg/天）对去氧皮质酮醋酸盐（DOCA）-盐高血压大鼠心血管功能的影响。Wistar 大鼠（n=120，8 周龄）接受单侧肾切除术，并随机分为四组（单侧肾切除术（UNX）、UNX+E、DOCA、DOCA+E）。DOCA 和 DOCA+E 组给予 1%NaCl 饮用水，并每隔四天皮下注射 25mg 去氧皮质酮醋酸盐（溶于 0.4ml 二甲基甲酰胺）。UNX+E 和 DOCA+E 组通过口服灌胃给予 1mg/kg/天的表儿茶素。单细胞微电极电生理学、Langendorff 分离心脏评估以及分离的主动脉和肠系膜器官浴用于评估心血管参数。血清丙二醛浓度用作氧化应激的标志物。在 DOCA 对照组中，心肌僵硬度增加，左心室顺应性显著降低，表儿茶素治疗可减轻这些变化（<0.05）。此外，DOCA+E 组的血压和丙二醛浓度明显降低；然而，左心室肥厚、电生理学或血管功能没有改善。本研究表明，表儿茶素能够降低血压，防止心肌僵硬并保持肥厚 DOCA-盐大鼠心脏的顺应性。
