Department of Emergency Medicine, Shengjing Hospital of China Medical University, Shenyang 110004, People's Republic of China.
Department of Endocrinology, Shengjing Hospital of China Medical University, Shenyang 110004, People's Republic of China.
Life Sci. 2017 Feb 1;170:25-32. doi: 10.1016/j.lfs.2016.11.021. Epub 2016 Nov 24.
To evaluate the detoxifying effect of epigallocatechin-3-gallate (EGCG) on paraquat (PQ)-induced acute lung injury in mice, and to explore the action mechanisms.
Following administration of PQ, the mice received a low, a medium or a high dose of EGCG daily for three days. Histopathology of the lungs were examined by H&E staining. The levels of inflammatory cytokines, such as TNF-α, IL-1β and IL-6, in the bronchoalveolar lavage fluid were measured by enzyme-linked immunosorbent assay. Activation of NF-κB was assessed by Western blot and electrophoretic mobility gel shift assay. The expression of toll-like receptor (TLR)-2, 4, 9 and TLR adaptors (MyD88 and TRAF6) was detected by Western blot and immunohistochemical staining. The protective effect of EGCG against PQ toxicity was validated in vitro using A549 lung cancer cell line.
Treatment with EGCG dose-dependently attenuated PQ-induced acute lung injury in mice by reducing alveolar edema, hemorrhage, inflammatory cell infiltration and production of inflammatory cytokines. EGCG inhibited the activation of NF-κB and the upregulation of TLR 2, 4 and 9 as well as their adaptors MyD88 and TRAF6 in the lungs following PQ challenge. In addition, EGCG significantly reduced PQ-induced cell death, cytokine production, activation of NF-κB, and upregulation of TLRs and adaptors in A549 cells.
Our data suggest that TLR-mediated activation of NF-κB in the non-immune pulmonary cells could be involved in PQ-induced acute lung injury, and it may serve as a target of EGCG against PQ pulmonary toxicity.
评估表没食子儿茶素没食子酸酯（EGCG）对百草枯（PQ）诱导的小鼠急性肺损伤的解毒作用，并探讨其作用机制。
PQ 给药后，小鼠每日接受低、中、高剂量 EGCG 治疗 3 天。通过 H&E 染色检查肺组织病理学。酶联免疫吸附试验测定支气管肺泡灌洗液中 TNF-α、IL-1β 和 IL-6 等炎症细胞因子的水平。通过 Western blot 和电泳迁移凝胶阻滞试验评估 NF-κB 的激活。通过 Western blot 和免疫组织化学染色检测 Toll 样受体（TLR）-2、4、9 和 TLR 衔接子（MyD88 和 TRAF6）的表达。通过体外 A549 肺癌细胞系验证 EGCG 对 PQ 毒性的保护作用。
EGCG 剂量依赖性地减轻 PQ 诱导的小鼠急性肺损伤，减少肺泡水肿、出血、炎症细胞浸润和炎症细胞因子的产生。EGCG 抑制 NF-κB 的激活以及 TLR 2、4 和 9 及其衔接子 MyD88 和 TRAF6 在 PQ 攻击后肺部的上调。此外，EGCG 显著减少 PQ 诱导的 A549 细胞死亡、细胞因子产生、NF-κB 激活以及 TLR 和衔接子的上调。
我们的数据表明，TLR 介导的非免疫肺细胞中 NF-κB 的激活可能参与了 PQ 诱导的急性肺损伤，并且它可能成为 EGCG 对抗 PQ 肺毒性的靶点。
