Investigation of the effects of lipopolysaccharide preconditioning on neuropathic pain induced by chronic sciatic nerve constriction injury in rats

Background: Neuropathic pain results from nerve injury and involves pro-inflammatory cytokines that activate pain-sensing neurons, contributing to both the onset and maintenance of pain. This study investigated the effect of lipopolysaccharide (LPS) preconditioning on pain following sciatic nerve constriction in rats. Methods: Neuropathic pain was induced via the chronic constriction injury (CCI). Rats received 0.1 mg LPS intraperitoneally three days before CCI. They were divided into four groups: control, CCI without LPS, CCI with LPS, and LPS alone. Pain behavior was assessed on days 0, 7, and 14 using acetone and hot plate tests. Results: LPS alone did not affect pain sensitivity. CCI increased responses to thermal and cold stimuli. However, prior LPS reduced these responses compared to CCI alone. Conclusion: This study suggests that 0.1 mg LPS can alleviate neuropathic pain by increasing pain threshold after nerve injury.