Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul, 156-756, Republic of Korea.
Department of Pharmaceutical botany, College of Pharmacy, Chung-Ang University, Seoul, 156-756, Republic of Korea.
Arch Pharm Res. 2016 Sep;39(9):1324-34. doi: 10.1007/s12272-016-0808-7. Epub 2016 Aug 13.
Quercetin-3-O-β-D-glucuronopyranoside (QGC) is a flavonoid glucoside extracted from Rumex Aquaticus. Recent studies have shown that QGC exhibits anti-inflammatory, anti-oxidateve effect in vivo and cytoprotective effect in vitro. Reactive oxygen species (ROS), at low concentration, play role as a primary signal or second messenger, however, at high concentration, ROS are cytotoxic. In this study, we investigated the protective mechanism of QGC in H2O2-induced injury of Feline Esophageal Epithelial Cells. Primary-cultured feline esophagus cells were identified by an indirect immunofluorescent staining method using a cytokeratin monoclonal antibody. Cell viability was determined by the conventional MTT reduction assay. Western blot analysis was performed with specific antibodies to investigate the activation of MAPKs, NF-κB, and IκB-α, and the expression of COX-2. When the cells were exposed to 600 μM H2O2 medium for 24 h, cell viability decreased to 54 %. However, when cells were pretreated with 50-150 μM QGC for 12 h, the viability of cells exposed to H2O2 significantly increased in the dose dependent manner. QGC (50 μM, 12 h) also inhibited the expression of COX-2 induced by 10 μM H2O2 for 24 h. We found that treatment of H2O2 activated p38 MAPK and JNK, but not ERK. However QGC inhibited the H2O2-induced p38 MAPK and JNK phosphorylation. In addition, NF-κB was activated by H2O2 and translocated into the nucleus, but QGC inhibited the activation of NF-κB by blocking degradation of IκB. These data suggest that QGC reduces H2O2-induced COX-2 production by modulating the p38 MAPK, JNK, NF-κB signal pathway in feline esophageal epithelial cells.
槲皮素-3-O-β-D-葡萄糖醛酸苷（QGC）是从酸模中提取的一种类黄酮糖苷。最近的研究表明，QGC 在体内具有抗炎、抗氧化作用，在体外具有细胞保护作用。活性氧（ROS）在低浓度时作为初级信号或第二信使发挥作用，但在高浓度时，ROS 具有细胞毒性。在这项研究中，我们研究了 QGC 对 H2O2 诱导的猫食管上皮细胞损伤的保护机制。通过使用角蛋白单克隆抗体的间接免疫荧光染色法鉴定原代培养的猫食管细胞。通过常规 MTT 还原测定法测定细胞活力。通过 Western blot 分析用特定抗体研究 MAPKs、NF-κB 和 IκB-α 的激活以及 COX-2 的表达。当细胞暴露于 600μM H2O2 培养基 24 小时时，细胞活力下降至 54%。然而，当细胞用 50-150μM QGC 预处理 12 小时时，暴露于 H2O2 的细胞活力呈剂量依赖性显著增加。QGC（50μM，12 小时）还抑制了 10μM H2O2 诱导的 COX-2 表达 24 小时。我们发现 H2O2 处理激活了 p38 MAPK 和 JNK，但不激活 ERK。然而，QGC 抑制了 H2O2 诱导的 p38 MAPK 和 JNK 磷酸化。此外，NF-κB 被 H2O2 激活并转移到核内，但 QGC 通过阻止 IκB 的降解来抑制 NF-κB 的激活。这些数据表明，QGC 通过调节猫食管上皮细胞中 p38 MAPK、JNK、NF-κB 信号通路减少 H2O2 诱导的 COX-2 产生。
