杜仲多糖对神经病理性疼痛模型大鼠的镇痛作用

The Analgesic Effect of EOP on Rats of Neuropathic Pain

目的:探索杜仲多糖(EOP)对CCI诱导的神经病理性疼痛大鼠的镇痛作用及可能的作用机制。方法:行为学检测不同剂量EOP(60 mg·kg^(-1)、120 mg·kg^(-1)和240 mg·kg^(-1))单次腹腔给药对CCI大鼠的机械学痛觉超敏的影响;利用免疫荧光标记方法检测连续给予EOP(120 mg·kg^(-1))对CCI大鼠诱导上调的GFAP和IBA-1的影响;用免疫蛋白印记(western blot)方法检测单次给予EOP(120 mg·kg^(-1))对CCI诱导活化的脊髓p-p38、p-JNK和p-ERK的蛋白水平的影响。结果:单次给予3个剂量的EOP均能显著降低CCI诱导的大鼠机械学超敏(P<0.05),且中、高剂量的EOP镇痛作用长达4 h(P<0.05);多次连续给予EOP能够抑制CCI诱导的GFAP表达(P<0.05),但是对IBA-1没有显著影响;单次EOP中、高剂量腹腔给药能够降低CCI大鼠脊髓活化的p-JNK和p-ERK蛋白表达水平(P<0.05),但是对活化的p-p38蛋白表达没有明显影响。结论:EOP能够抑制CCI诱导的神经病理性疼痛,其镇痛作用与抑制星形胶质细胞活化有关,可能通过抑制JNK/ERK MAPK信号通路发挥镇痛作用。

Objective:To evaluate the analgesic of Eucommia ulmoides Oliv Polysaccharide(EOP)on CCI-induced neuropathic pain and explore its possible mechanism.Methods:Effects of single intraperitoneal administration different doses of EOP(60 mg·kg^-1,120 mg·kg^-1,240 mg·kg^-1)on the CCI-induced mechanical allodynia by behavioral test;Detected the effect of consecutive administration of EOP(120 mg·kg^-1)on up-regulation expression of GFAP and IBA-1 in CCI rats by immunofluorescence labeling;Testing the expression of p-p38,p-JNK and p-ERK in the spinal cord activated by CCI after single administration of EOP(120 mg·kg^-1)with western blot.Results:Single administration of three doses EOP could significantly reduse the mechanical hypersensitivity induced by CCI(P<0.05),in additon,the analgesic effect of EOP at moderate and high dose was as long as 4 hours(P<0.05);Consecutive administration of EOP could decrease the expression of GFAP induced by CCI(P<0.05),but have no significant effect on IBA-1;Single moderate and high doses of EOP could significantly decline the expression of p-JNK and p-ERK in the spinal cord of CCI rats(P<0.05),but has no effect on p-p38.Conclusions:EOP can inhibit neuropathic pain induced by CCI,and its analgesic effect is related to reducing astrocyte activation and suppressing the aberrant activation of JNK/ERK MAPK signaling pathway.