Antinociceptive effects of fucoidan in rat models of vincristine-induced neuropathic pain.

Chemotherapeutic drugs commonly induce peripheral neuropathic pain, which limit their clinic use. In the present study, the effect of fucoidan on the development of vincristine‑induced neuropathic pain was evaluated and the underlying mechanism was examined. A neuropathy model was established in Sprague‑Dawley rats by intraperitoneal injection of vincristine sulfate 50 µg/kg once a day for 10 consecutive days. Fucoidan (50, 100 or 200 mg/kg.) and pregabalin (10 mg/kg) were injected for 14 consecutive days. Behavioral assessments were then performed and the expression of GABAB receptor was determined. The results showed that a single treatment with fucoidan did not prevent the induction of vincristine‑induced mechanical or cold allodynia. However, repeated fucoidan administration attenuated vincristine‑induced mechanical and cold allodynia in a dose‑dependent manner. Additionally, the analgesic effects of fucoidan contributed to an upregulation in the expression of GABAB receptor in the spinal cord. Furthermore, all the effects of fucoidan against vincristine‑induced neuropathy were reversed by saclofen, a selective GABAB receptor antagonist. These results suggested that the antinociceptive effects of fucoidan may be through activation of GABAB receptor, and fucoidan may be a promising drug for the treatment of chemotherapeutic drug-induced neuropathic pain.