Emerging evidence has shown that protocatechuic acid (PCA) has antioxidant and anti-inflammatory effects. It can alleviate the injury of sciatic nerve, while the mechanism of its therapeutic effect on neuralgia remains unknown . In vivo, chromium bowel ligation was used to establish a chronic constriction injury (CCI) rat model to induce sciatic nerve pain, then two doses of PCA were used to treat CCI rats. In vitro, 10 ng/mL TNF-α was used to stimulate glial satellite cells derived from the dorsal root ganglia (DRG) L4-L6 of the sciatic nerve to simulate sciatic nerve pain. PCA relieved mechanical allodynia and thermal hyperalgesia in CCI rats. CCK-8 assay revealed that PCA inhibited the proliferation of glial satellite cells induced by TNF-α. Moreover, ELISA demonstrated that PCA could improve the inflammatory response of rats caused by CCI and cells induced by TNF-α. Next, RT-qPCR and Western blot assays testified that PCA blocked the c-Jun N-terminal kinase/the chemokine ligand 1/CXC chemokine receptor 2 (JNK/CXCL1/CXCR2) pathway by inhibiting CXCL1 levels in cells induced by TNF-α and DRG of CCI rats. In conclusion, PCA can alleviate neuropathic pain of CCI rats, improve oxidative stress by inhibiting the JNK/CXCL1/CXCR2 signaling pathway, which provides a new perspective for the treatment of neuropathic pain caused by CCI.

中文翻译：

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原儿茶酸作为 JNK/CXCL1/CXCR2 通路的抑制剂可缓解 CCI 大鼠的神经性疼痛。

新出现的证据表明，原儿茶酸 (PCA) 具有抗氧化和抗炎作用。可减轻坐骨神经损伤，但其对神经痛的治疗作用机制尚不清楚。在体内，采用铬肠结扎法建立慢性缩窄性损伤（CCI）大鼠模型诱导坐骨神经痛，然后用两剂PCA治疗CCI大鼠。在体外，使用 10 ng/mL TNF-α 刺激源自坐骨神经背根神经节 (DRG) L4-L6 的胶质卫星细胞，以模拟坐骨神经疼痛。PCA 可缓解 CCI 大鼠的机械异常性疼痛和热痛觉过敏。CCK-8测定显示PCA抑制TNF-α诱导的胶质卫星细胞增殖。而且，ELISA表明PCA可以改善CCI引起的大鼠和TNF-α诱导的细胞的炎症反应。接下来，RT-qPCR 和蛋白质印迹分析证明，PCA 通过抑制 TNF-α 诱导的细胞中的 CXCL1 水平来阻断 c-Jun N-末端激酶/趋化因子配体 1/CXC 趋化因子受体 2 (JNK/CXCL1/CXCR2) 通路和 CCI 大鼠的 DRG。综上所述，PCA通过抑制JNK/CXCL1/CXCR2信号通路可减轻CCI大鼠神经性疼痛，改善氧化应激，为CCI所致神经性疼痛的治疗提供了新的视角。