The Analgesic Effects of Nrf2 Activators in Chemotherapy-Induced Neuropathic Pain: Evidence from Animal Studies and Consequences for Translation into Clinical Trials.

Chemotherapy-induced neuropathic pain (CINP) can be caused by several chemotherapeutic drugs, including paclitaxel, oxaliplatin, and vincristine, which is difficult to treat with several drugs, including antidepressants and anticonvulsants. The patho-mechanisms of CINP are not completely understood. However, they showed oxidative stress, mitochondrial damage, ion channel damage, and immunological dysfunction. Acting as a key regulator of antioxidant responses, nuclear factor erythroid 2-related factor 2 (Nrf2) decreased oxidative stress and mitochondrial damage. In addition, it plays a role in inhibiting nuclear factor kappa B (NF-κB). A systematic, English-only search of MEDLINE (PubMed) was performed for studies on Nrf2, chemotherapy, and neuropathic pain from database inception through 1 December 2024. Several Nrf2 activators, including tempol, oltipraz, rosiglitazone, pristimerin, cannabidiol, daidzein, bardoxolone methyl, curcumin, resveratrol, and mitoquinone, demonstrated analgesic effects in CINP animal models. Furthermore, in clinical studies, curcumin demonstrated significant efficacy in reducing vincristine-induced neuropathy in pediatric leukemia patients, while the combined administration of alpha-lipoic acid with ipidacrin hydrochloride prevented paclitaxel-induced motor neuropathy and improved axonal function in breast cancer patients. Thus, the purposes of our review article were to summarize the analgesic effects of Nrf2 activators and the patho-mechanisms of Nrf2 in CINP animal, and then the consequences for clinical trials were presented.