Department of Pharmacology and Institute of New Drug Development, School of Medicine, Chonbuk National University, Jeonju, Chonbuk, South Korea.
Division of Food and Nutrition, College of Human Ecology, Chonnam National University, Gwang-ju, South Korea.
Biomed Pharmacother. 2018 Jan;97:1164-1172. doi: 10.1016/j.biopha.2017.11.035. Epub 2017 Nov 11.
Eucommia ulmoides leaves (EULs), referred to as Du-zhong, are utilized to lower blood pressure and improve liver and kidney tone, and also have been applied to cardiovascular disease in Korea, China, and Japan. Endothelial dysfunction, which is caused by endothelial nitric oxide synthase (eNOS) uncoupling, is an initial step in atherosclerosis. In this study, we investigated the protective effects of EUL aqueous extract against ox-LDL-induced eNOS uncoupling and its possible mechanisms in human umbilical vein endothelial cells (HUVECs). A EUL component, aucubin, was also applied to ox-LDL-exposed HUVECs. Whereas ox-LDL significantly decreased nitric oxide (NO) levels in HUVECs, EUL extract and aucubin led to significant recovery of NO levels. When treated with ox-LDL in the presence of EUL extracts or aucubin, O production was markedly reduced in HUVECs compared to treatment with ox-LDL alone. EUL extract and aucubin also led to recovery of phospho-eNOS Thr495 expression, a critical signaling component in eNOS uncoupling, suggesting that EUL has regulatory effects against eNOS uncoupling and might play preventive/regulatory roles against vascular endothelial dysfunction.
杜仲叶（EULs），又称杜仲，具有降血压、护肝补肾的功效，在韩国、中国和日本被应用于心血管疾病。内皮型一氧化氮合酶（eNOS）解偶联引起的内皮功能障碍是动脉粥样硬化的初始步骤。在这项研究中，我们研究了杜仲叶水提物对 ox-LDL 诱导的 eNOS 解偶联的保护作用及其在人脐静脉内皮细胞（HUVECs）中的可能机制。杜仲叶的一个成分桃叶珊瑚苷也被应用于 ox-LDL 暴露的 HUVECs。虽然 ox-LDL 显著降低了 HUVECs 中的一氧化氮（NO）水平，但杜仲叶提取物和桃叶珊瑚苷显著恢复了 NO 水平。与 ox-LDL 单独处理相比，当 HUVECs 中存在杜仲叶提取物或桃叶珊瑚苷时，O 2 的产生明显减少。杜仲叶提取物和桃叶珊瑚苷也恢复了磷酸化 eNOS Thr495 的表达，这是 eNOS 解偶联的一个关键信号成分，表明杜仲叶具有对抗 eNOS 解偶联的调节作用，可能对血管内皮功能障碍具有预防/调节作用。
