Key Laboratory of Pathobiology, Department of Pharmacology, Ministry of Education, College of Basic Medicine, Jilin University, Changchun, Jilin 130021, China.
Department of Pharmacology, Pharmaceutical College of Beihua University, Jilin City, Jilin 132013, China.
Mediators Inflamm. 2013;2013:260464. doi: 10.1155/2013/260464. Epub 2013 Dec 9.
Endothelial dysfunction is a critical factor during the initiation of cardiovascular complications in diabetes. Berberine can ameliorate endothelial dysfunction induced by diabetes. However, the underlying mechanisms remain unclear. The aim of this study was to investigate the protective effect and mechanism of berberine on palmitate-induced endothelial dysfunction in human umbilical vein endothelial cells (HUVECs). The cell viability of HUVECs was determined by MTT assays. Nitric oxide (NO) level and production of reactive oxygen species (ROS) were determined in supernatants or in the cultured HUVECs. The mRNA level of endothelial nitric oxide synthase (eNOS) was measured by RT-PCR, and the protein levels of eNOS, p-eNOS, Akt, p-Akt, AMPK, p-AMPK, and NADPH oxidase (NOX4) were analyzed. The results demonstrated that berberine significantly elevated NO levels and reduced the production of ROS. The expressions of eNOS were significantly increased, while NOX4 protein expression was decreased in berberine-treated HUVECs. Moreover, berberine upregulated the protein expression of AMPK and p-AMPK in palmitate-treated HUVECs, but had no effect on the levels of Akt. Therefore, berberine ameliorates palmitate-induced endothelial dysfunction by upregulating eNOS expression and downregulating expression of NOX4. This regulatory effect of berberine may be related to the activation of AMPK.
内皮功能障碍是糖尿病引发心血管并发症的一个关键因素。小檗碱可以改善糖尿病引起的内皮功能障碍。然而，其潜在机制尚不清楚。本研究旨在探讨小檗碱对人脐静脉内皮细胞（HUVECs）中棕榈酸诱导的内皮功能障碍的保护作用及其机制。通过 MTT 法测定 HUVECs 的细胞活力。测定上清液或培养的 HUVECs 中的一氧化氮（NO）水平和活性氧（ROS）的产生。通过 RT-PCR 测定内皮型一氧化氮合酶（eNOS）的 mRNA 水平，并用 Western blot 分析 eNOS、p-eNOS、Akt、p-Akt、AMPK、p-AMPK 和 NADPH 氧化酶（NOX4）的蛋白水平。结果表明，小檗碱显著提高了 NO 水平，降低了 ROS 的产生。eNOS 的表达明显增加，而小檗碱处理的 HUVECs 中 NOX4 蛋白表达减少。此外，小檗碱上调了棕榈酸处理的 HUVECs 中 AMPK 和 p-AMPK 的蛋白表达，但对 Akt 水平没有影响。因此，小檗碱通过上调 eNOS 表达和下调 NOX4 表达来改善棕榈酸诱导的内皮功能障碍。小檗碱的这种调节作用可能与 AMPK 的激活有关。
