Murase T, Kume N, Hase T, Shibuya Y, Nishizawa Y, Tokimitsu I, Kita T
Biological Science Laboratories, Kao Corp, Ichikaimachi, Tochigi, Japan.
Arterioscler Thromb Vasc Biol. 1999 Jun;19(6):1412-20. doi: 10.1161/01.atv.19.6.1412.
Gallates (gallic acid esters) belong to the class of phenolic compounds, which are abundant in red wine. In this study, we show that gallates can inhibit cytokine-induced activation of nuclear factor kappaB (NF-kappaB) and thereby reduce expression of endothelial-leukocyte adhesion molecules in cultured human umbilical vein endothelial cells (HUVECs). Pretreatment of HUVECs with ethyl gallate (3 to 10 micromol/L) significantly suppressed interleukin-1alpha (IL-1alpha)- or tumor necrosis factor-alpha (TNF-alpha)- induced mRNA and cell-surface expression of vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1), and E-selectin, which was associated with reduced adhesion of leukocytes to HUVECs. Gel shift assays with the NF-kappaB consensus sequence showed the decreased densities of the shifted bands in gallate-treated HUVECs. Furthermore, gallate pretreatment inhibited cytokine-induced transcription of a fusion gene, which consisted of 4 repeats of the NF-kappaB consensus sequence and the luciferase reporter gene. Immunoblot analysis of nuclear extracts and whole-cell lysates demonstrated the decreased amounts of NF-kappaB p65 in nuclei but equal amounts of inhibitor-kappaBalpha (I-kappaBalpha) in whole-cell lysates of ethyl gallate-treated HUVECs. Incubation of the nuclear extracts from cytokine-activated HUVECs with ethyl gallate did not affect the NF-kappaB shifted bands induced by cytokines in gel shift assays. Taken together, these data demonstrate that ethyl gallate can inhibit cytokine-induced nuclear translocation of NF-kappaB p65 by way of a mechanism independent of I-kappaBalpha degradation and thereby suppress expression of VCAM-1, ICAM-1, and E-selectin, which was associated with reduced adhesion of leukocytes. These results in vitro demonstrate that gallates can exhibit anti-inflammatory properties by blocking activation of NF-kappaB and suggest that these natural compounds, abundant in red wine, may play important roles in the prevention of atherosclerosis and inflammatory responses in vivo.
没食子酸盐（没食子酸酯）属于酚类化合物，在红酒中含量丰富。在本研究中，我们发现没食子酸盐可抑制细胞因子诱导的核因子κB（NF-κB）激活，从而降低培养的人脐静脉内皮细胞（HUVECs）中内皮细胞与白细胞黏附分子的表达。用没食子酸乙酯（3至10微摩尔/升）预处理HUVECs可显著抑制白细胞介素-1α（IL-1α）或肿瘤坏死因子-α（TNF-α）诱导的血管细胞黏附分子1（VCAM-1）、细胞间黏附分子1（ICAM-1）和E-选择素的mRNA及细胞表面表达，这与白细胞对HUVECs黏附减少有关。用NF-κB共有序列进行凝胶迁移试验显示，没食子酸盐处理的HUVECs中迁移条带的密度降低。此外，没食子酸盐预处理可抑制细胞因子诱导的由NF-κB共有序列的4个重复序列和荧光素酶报告基因组成的融合基因的转录。对核提取物和全细胞裂解物的免疫印迹分析表明，没食子酸乙酯处理的HUVECs细胞核中NF-κB p65的量减少，但全细胞裂解物中抑制蛋白κBα（I-κBα）的量相等。在凝胶迁移试验中，将细胞因子激活的HUVECs的核提取物与没食子酸乙酯一起孵育，并不影响细胞因子诱导的NF-κB迁移条带。综上所述，这些数据表明没食子酸乙酯可通过一种独立于I-κBα降解的机制抑制细胞因子诱导的NF-κB p65核转位，从而抑制VCAM-1、ICAM-1和E-选择素的表达，这与白细胞黏附减少有关。这些体外研究结果表明，没食子酸盐可通过阻断NF-κB的激活发挥抗炎特性，并提示这些在红酒中大量存在的天然化合物可能在体内预防动脉粥样硬化和炎症反应中发挥重要作用。
