Chan Shih-Hung, Hung Ching-Hsia, Shih Jhih-Yuan, Chu Pei-Ming, Cheng Yung-Hsin, Tsai Yi-Ju, Lin Huei-Chen, Tsai Kun-Ling
Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
Institute of Allied Health Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
Oncotarget. 2016 Jul 12;7(28):42881-42891. doi: 10.18632/oncotarget.10263.
OxLDL facilitate reactive oxygen species (ROS) formation and up-regulation of the executioner caspase-3 via the mitochondrial apoptotic pathway involves several critical steps in human endothelial cells. Previous studies reported that oxLDL-facilitated endothelial oxidative stress is associated with impairment of eNOS and up-regulation of inducible nitric oxide synthase (iNOS). Baicalein is the most abundant component that has anti-HIV, anti-tumor, anti-oxidant and free radical scavenging functions. In this present study, we shown that baicalein hinibits oxLDL-caused endothelial dysfunction through suppression of endothelial inflammation and oxidative stress that causes to cellular apoptosis. Specifically, baicalein reduces the elevation of ROS concentration, which subsequently inhibits the oxLDL-decreased expression of anti-oxidant enzymes, enriches the bioavailability of NO, stabilizes the mitochondrial membrane, thereby inhibiting the discharge of cytochrome c from mitochondria, a molecule required for the activation of the pro-apoptotic protein caspase 3. However, inhibition of eNOS impairs the anti-apoptotic and anti-inflammatory effects of baicalein. These results provide new insight into the possible molecular mechanisms by which baicalein protects against atherogenesis by NO-related pathways.
氧化型低密度脂蛋白(OxLDL)通过线粒体凋亡途径促进活性氧(ROS)生成并上调凋亡执行蛋白半胱天冬酶-3,这在人类内皮细胞中涉及几个关键步骤。先前的研究报道,OxLDL促进的内皮氧化应激与内皮型一氧化氮合酶(eNOS)功能受损和诱导型一氧化氮合酶(iNOS)上调有关。黄芩苷是具有抗HIV、抗肿瘤、抗氧化和自由基清除功能的最丰富成分。在本研究中,我们表明黄芩苷通过抑制导致细胞凋亡的内皮炎症和氧化应激来抑制OxLDL引起的内皮功能障碍。具体而言,黄芩苷降低ROS浓度的升高,随后抑制OxLDL降低的抗氧化酶表达,提高一氧化氮(NO)的生物利用度,稳定线粒体膜,从而抑制细胞色素c从线粒体释放,细胞色素c是激活促凋亡蛋白半胱天冬酶3所需的分子。然而,抑制eNOS会损害黄芩苷的抗凋亡和抗炎作用。这些结果为黄芩苷通过NO相关途径预防动脉粥样硬化的可能分子机制提供了新的见解。