Department of Pharmacology, Xi'an Jiaotong University School of Medicine, Xi'an, China.
Life Sci. 2010 Mar 13;86(11-12):410-5. doi: 10.1016/j.lfs.2010.01.010. Epub 2010 Jan 25.
Extensive research suggests that atherosclerosis is an inflammatory disease and that epigallocatechin-3-gallate (EGCG) is able to inhibit the formation and development of atherosclerosis. However, the mechanisms of action of EGCG against atherosclerosis are still unclear. Therefore, the effect of EGCG on interleukin-6 (IL-6)- and angiotensin II (Ang II)-induced CRP production in vascular smooth muscle cells (VSMCs) was studied to provide experimental evidence for its anti-inflammatory and anti-atherosclerotic actions.
Rat VSMCs were cultured, and IL-6 (10(-7)M) and Ang II (10(-7)M) were used as stimulants for CRP generation. The CRP concentration in the supernatant was measured with ELISA, and mRNA and protein expression of CRP was assayed with RT-qPCR and immunocytochemistry, respectively. The production of reactive oxygen species (ROS) and superoxide anion (O(2)(-)) was detected with ROS and O(2)(-) assay kits, respectively.
The results showed that both IL-6 and Ang II increased CRP levels in the supernatant of VSMCs and induced mRNA and protein expression of CRP in VSMCs, whereas pretreatment of the cells with EGCG (1 x 10(-6)M, 3 x 10(-6)M, 10 x 10(-6)M) significantly inhibited IL-6- and Ang II-induced production and expression of CRP in VSMCs in a concentration-dependent manner. Additionally, Ang II stimulated O(2)(-) and ROS generations in VSMCs, and EGCG decreased the Ang II-induced increase of O(2)(-) and ROS in a concentration-dependent fashion.
These results suggest that EGCG plays an anti-inflammatory role via inhibiting IL-6- and Ang II-induced CRP secretion, as well as the Ang II-induced generation of O(2)(-) and ROS in VSMCs, which contributes to its anti-atherosclerotic action.
大量研究表明，动脉粥样硬化是一种炎症性疾病，表没食子儿茶素没食子酸酯（EGCG）能够抑制动脉粥样硬化的形成和发展。然而，EGCG 对抗动脉粥样硬化的作用机制尚不清楚。因此，本研究旨在探讨 EGCG 对血管平滑肌细胞（VSMCs）中白细胞介素 6（IL-6）和血管紧张素 II（Ang II）诱导 CRP 产生的影响，为其抗炎和抗动脉粥样硬化作用提供实验依据。
培养大鼠 VSMCs，用 IL-6（10（-7）M）和 Ang II（10（-7）M）刺激 CRP 生成。用 ELISA 法检测上清液中 CRP 浓度，用 RT-qPCR 和免疫细胞化学法分别检测 CRP 的 mRNA 和蛋白表达。用 ROS 和 O（2）（-）检测试剂盒分别检测活性氧（ROS）和超氧阴离子（O（2）（-））的产生。
结果表明，IL-6 和 Ang II 均增加了 VSMCs 上清液中 CRP 水平，并诱导了 VSMCs 中 CRP 的 mRNA 和蛋白表达，而 EGCG（1×10（-6）M、3×10（-6）M、10×10（-6）M）预处理细胞可浓度依赖性地显著抑制 IL-6 和 Ang II 诱导的 CRP 在 VSMCs 中的产生和表达。此外，Ang II 刺激 VSMCs 中 O（2）（-）和 ROS 的产生，EGCG 以浓度依赖的方式降低了 Ang II 诱导的 O（2）（-）和 ROS 的增加。
这些结果表明，EGCG 通过抑制 IL-6 和 Ang II 诱导的 CRP 分泌以及 Ang II 诱导的 VSMCs 中 O（2）（-）和 ROS 的产生发挥抗炎作用，这有助于其抗动脉粥样硬化作用。
