白脉软膏对慢性炎症性疼痛小鼠外周敏化的干预作用

Therapeutic effect of Baimai Ointment on peripheral sensitization of chronic inflammatory pain in mice

慢性炎症性疼痛以周围敏化为主要表现形式,藏族药经典外用方剂白脉软膏治疗慢性炎症性疼痛临床疗效确切,但其缓解周围敏化的药效学及机制尚不明确。该研究拟建立完全弗氏佐剂诱导的慢性炎症性疼痛动物模型,并采用行为学检测、副作用评估、网络分析及实验验证等方法探讨白脉软膏治疗慢性炎症性疼痛的药效及机制。药效学研究表明白脉软膏可剂量依赖性提高慢性炎症性疼痛小鼠致炎足机械痛敏及热辐射痛敏阈值且无耐受性,对足肿胀、炎症介质及TRPV1、TRPA1的表达也有明确的抑制作用;体质量监测、正常小鼠痛敏阈值检测、轮替、强迫游泳实验等结果显示白脉软膏无明显毒副作用;根据白脉软膏基原药材药效、主要成分含量、ADME参数等纳入的51个候选活性分子网络分析显示,白脉软膏对慢性炎症性疼痛的抑制作用与调节TNF、T细胞受体信号通路核心调控元件相关;进一步实验研究表明,白脉软膏可有效下调小鼠足跖部组织MAPK14、MAPK1、PTGS2的蛋白表达,并上调GSK3B的磷酸化水平。综上,白脉软膏可有效缓解慢性炎症性疼痛的周围痛敏且无耐受性及明显的毒副作用,相关机制可能与白脉软膏调控周围组织TNF及T细胞受体信号通路的核心调控元件相关。

Chronic inflammatory pain is mainly manifested by peripheral sensitization. Baimai Ointment(BMO), a classical Tibetan medicine for external use, has good clinical efficacy in the treatment of chronic inflammatory pain, while its pharmacodynamics and mechanism for relieving peripheral sensitization remain unclear. This study established an animal model of chronic inflammatory pain induced by complete Freund′s adjuvant to explore the mechanism of BMO in the treatment of chronic inflammatory pain by behavioral test, side effect assessment, network analysis, and experimental verification. The pharmacodynamics experiment showed that BMO increased the thresholds of mechanical pain sensitivity and thermal radiation pain sensitivity of chronic inflammatory pain mice in a dose-dependent manner, and had inhibitory effect on foot swelling, inflammatory mediator, and the expression of transient receptor potential vanilloid-1(TRPV1) and transient receptor potential A1(TRPA1). The results of body weight monitoring, pain sensitivity threshold detection in normal mice, rotarod performance test, and forced swimming test showed that BMO had no obvious toxic or side effect. The network analysis of 51 candidate active molecules selected according to the efficacy of BMO, content of main components, and ADME parameters showed that the inhibitory effect of BMO on chronic inflammatory pain was associated with the core regulatory elements of tumor necrosis factor(TNF) and T cell receptor signaling pathways. BMO down-regulated the protein levels of mitogen-activated protein kinase 14(MAPK14), MAPK1, and prostaglandin-endoperoxide synthase 2(PTGS2), and up-regulated the phosphorylation le-vel of glycogen synthase kinase 3 beta(GSK3 B) in the plantar tissue of mice. In conclusion, BMO can effectively relieve peripheral sensitization of chronic inflammatory pain without inducing tolerance and obvious toxic and side effects. The relevant mechanism may be related to the regulation of BMO on core regulatory elements of TNF and T cell receptor signaling pathways in surrounding tissues.