Neuropathic pain is a major health issue that represents considerable social and economic burden worldwidely. In this study, we investigated the potential of catalpol, an iridoid glucoside ofRehmannia glutinosa Steud, to alleviate neuropathic pain. The potential analgesic effects of catalpol were evaluated by chronic constriction injury (CCI) and lumbar 5 spinal nerve ligation (L5 SNL) model. In addition, we explored whether catalpol altered the degree of microglia activation and neuroinflammation in rat spinal cord after CCI induction. Repeated administration of catalpol (1, 5, 25, and 125 mg/kg) reversed mechanical allodynia induced by CCI and L5 SNL in a dose-dependent manner in rats. Levels of activated microglia, activated NF-κB, and proinflammatory cytokines (IL-1β, IL-6, TNF-α) in lumber

 Catalpol was purchased form Chengdu Biopurify Phytochemicals Ltd. (Chengdu, China) with a purity of 99 %. ...