虎杖提取物对神经病理性疼痛模型大鼠的镇痛作用研究

目的：研究虎杖提取物对神经病理性疼痛模型大鼠的镇痛作用,并探讨其作用机制。方法雄性SD大鼠,随机分为对照组和坐骨神经缩狭模型（chronic construction injury, CCI）组。CCI术后14 d,应用Von Frey法测定机械刺激缩足反射阈值（mechanical withdrawal threshold, MWT）,观察口服不同剂量的虎杖提取物对CCI大鼠机械性痛觉超敏的影响。并考察不同剂量虎杖提取物对CCI大鼠脊髓p-ERK、p-P38水平及小胶质细胞活化的影响。结果虎杖提取物可明显升高CCI大鼠术侧的MWT值（P〈0.05）,而对正常大鼠的MWT值没有显著影响（P〉0.05）。同时虎杖提取物可显著抑制CCI模型大鼠脊髓ERK和p38的磷酸化,并显著抑制IBA-1表达增加。结论虎杖提取物对CCI诱导的机械性痛觉超敏具有显著性的抑制作用,且镇痛作用维持时间长于吗啡,其机制可能是通过抑制脊髓水平ERK和p38的磷酸化,及通过抑制小胶质细胞活化而实现。

Analgesic effect of polygonum cuspidatum extract in rat model of neuropathic pain

Objective To study the analgesic effect and mechanism of polygonum cuspidatum extract in the neuropathic pain using rat chronic constriction （CCI） mode. Methods The SD rats were randomly divided into control and model groups. After 14 days of CCI, we observe the effect of different doses of polygonum cuspidatum extract on rat mechanical allodynia using von Frey flinching reflex threshold （mechanical withdrawal threshold, MWT）, The levels of p-ERK, p-P38 and the activation of microglial cells in rat spinals were measured by Western blotting. Results polygonum cuspidatum extract can significantly increase the value of MWT in CCI rats （P＆lt;0.05）, whereas had no significant effect in normal rats （P＆gt;0.05）. Meanwhile, polygonum cuspidatum extract significantly inhibited the phosphorylation of ERK and p38, and inhibited the expression of IBA-1 in CCI rat. Conclusion Polygonum cuspidatum extract can inhibit the mechanical allodynia in CCI rat, and the duration is longer than the analgesic effect of morphine. The mechanism may be associated with the inhibition of the phosphorylation of ERK and p38, and inhibition of microglial cell activation in rat spinal.