Analgesic potency of intrathecally administered punicalagin in rat neuropathic and inflammatory pain models

We examined whether punicalagin ameliorates neuropathic pain and inflammatory pain in the spinal cord. Male Sprague –Dawley rats were subjected to chronic constriction injury (CCI) of the sciatic nerve, and an intrathecal catheter was implanted for drug administration. The electronic von Frey test and cold-plate test were performed in CCI rats to evaluate mechanical and cold hyperalgesia in neuropathic pain, an d the formalin test was performed in normal rats to evaluate acute and persistent inflammatory pain. An open-field test was conducted to explore whether punicalagin affects locomotor activity in CCI rats. Punicalagin administered intrathecally attenuated mechanical and cold hyperalgesia to the same degree as gabapentin in CCI rats and reduced pain-related behaviors in both the early and late phases in formalin-injected rats. Punicalagin did not affect motor function. These results suggest that punicalagin exerts an antinociceptive effect in the spinal cord without motor deficit, thus showing t herapeutic potential for neuropathic pain and inflammatory pain.
Source: Journal of Natural Medicines - Category: Drugs & Pharmacology Source Type: research