Jujuboside A Alleviates Facial Allodynia of CCI-ION Rats by Inhibiting the Expression of P2X7 Receptor in the Spinal Trigeminal Subnucleus Caudalis.

Abstract

BACKGROUND: Trigeminal neuralgia is a common neuropathic pain of the oral and maxillofacial region. P2X7 receptor, a neural mediator, P2X7 receptor is closely related to this condition. Despite several studies on the role of Jujuboside A in sleep, few reports are available on its effects on chronic neuropathic pain. METHODS: In this study, a rat trigeminal neuralgia model was established by chronic constriction injury of the infraorbital nerve. Rats were intervened with Jujuboside A and P2X7 shRNA. For the behavioral aspect, the changes in the facial mechanical pain withdrawal threshold of the rats were measured. Molecular biology techniques such as Western Blotting, Real-Time Quantitative PCR, Immunohistochemistry and Enzyme-Linked Immunosorbent Assay were used to determine the changes in the P2X7 receptor, pyroptosis pathway, and inflammatory factors. RESULTS: The facial mechanical withdrawal threshold showed a significantly greater reduction in the trigeminal neuralgia group than in the sham group at 14 days post-operation. Jujuboside A therapy could alleviate the facial allodynia and inhibit the up-regulation of P2X7 expression in the spinal trigeminal subnucleus caudalis. Additionally, the expression of P2X7, nucleotide-binding domain, leucine-rich family, and pyrin domain-containing 3 caspase-1 and interleukin-1β was significantly greater in the trigeminal neuralgia group than in the sham group, suggesting activation of the pyroptosis cascade; this could be reversed by Jujuboside A application. Moreover, Jujuboside A administration downregulated the phosphorylation of ERK1/2 in the spinal trigeminal subnucleus caudalis of the trigeminal neuralgia group. Molecular docking demonstrated a high binding force between Jujuboside A and P2X7. Furthermore, the P2X7 knockdown treatments effectively increased the facial mechanical withdrawal threshold of trigeminal neuralgia rats. CONCLUSION: These findings suggest the potential benefits of Jujuboside A in trigeminal neuralgia treatment through suppression of pyroptosis by inhibition of the nucleotide-binding domain, leucine-rich family, and pyrin domain-containing 3/caspase-1 pathway mediated by the P2X7 receptor in the spinal trigeminal subnucleus caudalis.