Benzimidazole Derivative Ameliorates Opioid-Mediated Tolerance during Anticancer- Induced Neuropathic Pain in Mice.

Background: Cancer is known to be the second significant cause of death worldwide. Chemotherapeutic agents such as platinum-based compounds are frequently used single-handedly or accompanied by additional chemotherapies to treat cancer patients. Chemotherapy-induced peripheral painful neuropathy is seen in around 40% of patients who are treated with platinum-based compounds, including cisplatin. This not only decreases the quality of life of patients but also patients' compliance with cisplatin.

Objectives: Nalbuphine, an opioid, is frequently used to treat acute and chronic pain, coupled with cisplatin in cancer patients. However, long term use of nalbuphine induces tolerance to its analgesic effects. We employed the same strategy to induce tolerance in mice.

Methods: Here, we investigated analgesic effects of 2-[(pyrrolidin-1-yl) methyl]-1H-benzimidazole (BNZ), a benzimidazole derivative, on nalbuphine-induced tolerance during cisplatin-induced neuropathic pain using hot plate test, tail-flick tests and von Frey filament in mouse models. Furthermore, we investigated the effects of BNZ on the expression of Tumor Necrosis Factor-alpha (TNF-α) in the spinal cord.

Results: The results showed that BNZ reduced tolerance to analgesic effects of nalbuphine and TNF-α expression in mice.

Conclusion: BNZ could be a potential drug candidate for the management of nalbuphine-induced tolerance in cisplatin-induced neuropathic pain.