Curcumin relieves oxaliplatin-induced neuropathic pain via reducing inflammation and activating antioxidant response

Oxaliplatin (OXA) has shown high effectiveness in the treatment of cancers, but its anticancer clinical effects often induce neurotoxicity leading to neuropathic pain. Oxidative damage and NLRP3 inflammasome play important roles in neuropathic pain development. Here, neuropathic pain mouse model was constructed by continuous intraperitoneal injection of OXA. OXA administration induced mechanical pain, spontaneous pain, thermal hyperalgesia and motor disability in mice. The spinal cord tissues of OXA mice exhibited the suppressed antioxidative response, the activated NLRP3 inflammasome mediated inflammatory responses, and the increased GSK-3β activity. Next, we injected curcumin (CUR) intraperitoneally in OXA mice for seven consecutive days. CUR-treated mice showed increased mechanical pain thresholds, reduced number of spontaneous flinches, increased paw withdrawal latency, and restored latency to fall. While in the spinal cord, CUR treatment inhibited the NLRP3 inflammasome mediated inflammatory response, increased Nrf2/GPX4-mediated antioxidant responses, and decreased mitochondrial oxidative generation. Additionally, CUR combined with GSK-3β through four covalent bonds and reduced GSK-3β activity. In conclusion, our findings suggest that CUR treatment inhibits GSK-3β activation, increases Nrf2 mediated antioxidant responses, inhibits oxidative damage and inflammatory reaction, and alleviates OXA-induced neuropathic pain.