丹参酮ⅡA对长春新碱诱导神经病理痛大鼠痛觉过敏的影响及其机制

Effect of Tanshinone ⅡA on Hyperalgesia Induced by Vincristine in Rats with Neuropathic Pain and its Mechanism

目的:探讨腹腔注射丹参酮ⅡA对长春新碱诱导神经病理痛痛觉过敏的影响及其可能机制。方法:雄性SD大鼠40只,随机分为4组(n=10):正常对照组(Control)、化疗所致神经病理性疼痛组(CINP)(隔日腹腔注射长春新碱建立CINP模型)、CINP+NS组(CINP模型成功建立后腹腔注射生理盐水)和CINP+Tan组(CINP模型成功建立后腹腔注射丹参酮ⅡA)。采用热缩足反射潜伏期(TWL)和机械缩足反射阈值(MWT)评价大鼠机械痛敏和热痛敏。Western blott法检测脊髓p-JNK、GFAP以及离子钙结合适配器分子1(Iba1)表达;免疫荧光化学法检测脊髓GFAP和磷酸化c-Jun氨基末端激酶(p-JNK)共定位表达;逆转录-聚合酶链反应法检测脊髓TNF-α、IL-6、IL-1βmRNA表达;酶联免疫吸附测定法检测脊髓TNF-α、IL-6、IL-1β蛋白表达。结果:与Control组相比,CINP组大鼠从长春新碱注射后3d一直到14d MWT和TWL明显降低(P<0.01);与CINP+NS组相比,CINP+Tan组大鼠在给药后9、11、14d MWT和TWL明显增加(P<0.01)。与Control组相比,CINP组大鼠脊髓p-JNK、GFAP和TNF-α、IL-6、IL-1β蛋白以及mRNA表达明显上调(P<0.01);与CINP+NS组相比,CINP+Tan组大鼠脊髓p-JNK、GFAP和TNF-α、IL-6、IL-1β蛋白以及mRNA表达明显下调(P<0.05)。结论:腹腔注射丹参酮ⅡA明显抑制长春新碱诱导神经病理痛大鼠痛觉过敏,其作用机制可能与星形胶质细胞JNK通路活化及其炎症反应相关。

Objective:To investigate the effect of intraperitoneal tanshinone IIA on hyperalgesia induced by vincristine in rats with neuropathic pain and its possible mechanism.Methods:A total of 40 healthy male SD rats were randomly divided into 4 groups(10 in each):control group,chemotherapy-induced neuropathic pain(CINP)group(modeled by intraperitoneal injection of vincristine every other day),CINP+NS group(Successful establishment of CINP model and intraperitoneal injection of normal saline),CINP+Tan group(Successful establishment of CINP model and intraperitoneal injection of tanshinone IIA).Mechanical allodynia and heat hyperalgesia was evaluated with thermal withdrawal latency(TWL)and mechanical withdrawal threshold(MWT).Western blotting was used to detect the expression of phosphorylated c-Jun N-terminal kinase(p-JNK),glial fibrillary acidic protein(GFAP)and Ionized calcium binding adapter molecule(Iba1)in spinal cord,immunofluorescence assay to detect the Co-localization expression of GFAP and p-JNK,reverse transcription-polymerase chain reaction to detect the mRNA expression of tumor Necrosis Factor-α(TNF-α),interleukin-6(IL-6)and interleukin-1(IL-1β)andenzyme-linked immunosorbent assay to detect the protein expression of TNF-α,IL-6 and IL-1β.Results:The TWL and MWT in group CINP were significantly lower those in the control group from 3 days to 14 days after the first injection of vincristine(P<0.01).The MWT and TWL in group CINP+Tan were significantly higher than those in group CINP+NS(P<0.01).Significant up-regulation was found in group CINP as compared with the control group in protein expression of p-JNK,GFAP,TNF-α,IL-6 and IL-1βand the Mrna expression of TNF-α,IL-6 and IL-1βin spinal cord(P<0.01).Significant down-regulation was observed in group CINP+Tan as compared with the CINP+NS group in the protein expression of p-JNK,GFAP,TNF-α,IL-6,IL-1βand the mRNA expression of TNF-α,IL-6 and IL-1βin the spinal cord(P<0.05).The co-localization expression of GFAP and p-JNK were observed in spinal cord.Conclusion:Tanshinone IIA can inhibit the hyperalgesia of neuropathic pain rats induced by vincristine,and its mechanism may be related to the activation of JNK pathway and inflammation of astrocytes.