Chen Jaw-Wen, Chen Yung-Hsiang, Lin Feng-Yan, Chen Yuh-Lien, Lin Shing-Jong
National Yang-Ming University School of Medicine, Cardiovascular Research Center and Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taiwan, Republic of China.
Arterioscler Thromb Vasc Biol. 2003 Sep 1;23(9):1559-66. doi: 10.1161/01.ATV.0000089012.73180.63. Epub 2003 Jul 31.
This study was conducted to examination whether Ginkgo biloba extract (GBE), a Chinese herb with antioxidant activity, could reduce cytokine-induced monocyte/human aortic endothelial cell (HAEC) interaction, a pivotal early event in atherogenesis.
Pretreatment of HAECs with GBE (50 and 100 microg/mL for 18 hours) significantly suppressed cellular binding between the human monocytic cell line U937 and tumor necrosis factor-alpha (TNF-alpha)-stimulated HAECs by using in vitro binding assay (68.7% and 60.1% inhibitions, respectively). Cell enzyme-linked immunosorbent assay and immunoblot analysis showed that GBE (50 microg/mL for 18 hours) significantly attenuated TNF-alpha-induced cell surface and total protein expression of vascular cellular adhesion molecule-1 and intracellular adhesion molecule-1 (63.5% and 69.2%, respectively; P<0.05). However, pretreatment with probucol (5 micromol/L for 18 hours) reduced the expression of vascular cellular adhesion molecule-1 but not intracellular adhesion molecule-1. Preincubation of HAECs with GBE or probucol significantly reduced intracellular reactive oxygen species formation induced by TNF-alpha (76.8% and 68.2% inhibitions, respectively; P<0.05). Electrophoretic mobility shift assay demonstrated that both GBE and probucol inhibited transcription factor nuclear factor-kappaB activation in TNF-alpha-stimulated HAECs (55.2% and 65.6% inhibitions, respectively) but only GBE could inhibit the TNF-alpha-stimulated activator protein 1 activation (45.1% inhibition, P<0.05).
GBE could reduce cytokine-stimulated endothelial adhesiveness by downregulating intracellular reactive oxygen species formation, nuclear factor-kappaB and activator protein 1 activation, and adhesion molecule expression in HAECs, supporting the notion that the natural compound Ginkgo biloba may have potential implications in clinical atherosclerosis disease.
本研究旨在检测具有抗氧化活性的中药银杏叶提取物（GBE）是否能够减少细胞因子诱导的单核细胞/人主动脉内皮细胞（HAEC）相互作用，这是动脉粥样硬化形成过程中的一个关键早期事件。
使用体外结合试验，用GBE（50和100μg/mL，处理18小时）预处理HAECs，可显著抑制人单核细胞系U937与肿瘤坏死因子-α（TNF-α）刺激的HAECs之间的细胞结合（分别抑制68.7%和60.1%）。细胞酶联免疫吸附测定和免疫印迹分析表明，GBE（50μg/mL，处理18小时）可显著减弱TNF-α诱导的血管细胞黏附分子-1和细胞间黏附分子-1在细胞表面和总蛋白的表达（分别为63.5%和69.2%；P<0.05）。然而，用普罗布考（5μmol/L，处理18小时）预处理可降低血管细胞黏附分子-1的表达，但对细胞间黏附分子-1无影响。用GBE或普罗布考预孵育HAECs可显著减少TNF-α诱导的细胞内活性氧形成（分别抑制76.8%和68.2%；P<0.05）。电泳迁移率变动分析表明，GBE和普罗布考均可抑制TNF-α刺激的HAECs中转录因子核因子-κB的激活（分别抑制55.2%和65.6%），但只有GBE能抑制TNF-α刺激的激活蛋白1的激活（抑制45.1%，P<0.05）。
GBE可通过下调细胞内活性氧形成、核因子-κB和激活蛋白1的激活以及HAECs中黏附分子的表达，减少细胞因子刺激的内皮黏附性，支持天然化合物银杏叶可能对临床动脉粥样硬化疾病具有潜在意义的观点。
