盘龙七片对慢性炎性疼痛大鼠的镇痛作用

Analgesic Effect of Panlongqi Tablet on Rats with Chronic Inflammatory Pain

目的:观察盘龙七片对慢性炎性疼痛大鼠的镇痛作用,并从核转录因子-κB(NF-κB)和丝裂原活化蛋白激酶(MAPKs)信号通路入手探索其初步作用机制。方法:采用完全弗氏佐剂(CFA)诱导大鼠建立慢性炎性疼痛模型,分正常组、模型组、盘龙七片(0.16,0.32,0.64 g·kg^-1)组、阳性药布洛芬(0.05 g·kg^-1)组共6组,每天1次经口灌服盘龙七片或布洛芬,标准Von Frey纤维评价机械痛阈值,用丙酮刺激大鼠致炎足底观察冷刺激诱发痛的反应评分,观察第1天给药前和给药后1,2,3,4,6 h以及第3~7天给药后4 h的机械痛阈值和冷痛敏反应评分,酶联免疫吸附测定(ELISA)检测血清、致炎足和腰4~5脊髓背角中前列腺E2(PGE2),白细胞介素(IL)-1β和肿瘤坏死因子(TNF)-α的含量,蛋白免疫印迹法(Western blot)检测腰4~5脊髓背角中MAPKs(p-p38,p-ERK,p-JNK)的蛋白含量,免疫荧光检测腰4~5脊髓背角中NF-κB p65表达情况。结果:与正常组比较,模型组大鼠机械痛阈值降低而冷刺激反应评分升高(P<0.01);与模型组比较,0.16,0.32,0.64 g·kg^-1盘龙七片给药后可剂量依赖地升高模型大鼠的机械痛阈值和降低冷刺激反应评分(P<0.05,P<0.01),作用持续6 h,其中4 h作用最显著,布洛芬的作用与中剂量组相近。此外,盘龙七片能降低模型组大鼠血清、致炎足和脊髓背角中异常增高的PGE2,IL-1β和TNF-α含量,降低脊髓背角中ERK和JNK的磷酸化水平以及NF-κB p65的蛋白表达水平,以中大剂量组作用明显(P<0.01)。结论:盘龙七片对慢性炎性疼痛模型大鼠具有明显的镇痛作用,且这一作用可能与对脊髓背角NF-κB和MAPKs信号通路的抑制有关。

Objective:To observe the analgesic effect of Panlongqi tablet(PLQT)on rats with chronic inflammatory pain,and to explore mechanism of the action preliminarily from the perspective of the nuclear factor kappa-light-chain-enhancer of activated B cells(NF-κB)and mitogen-activated protein kinase(MAPKs)signaling pathways.Method:Rats were induced to establish model of chronic inflammatory pain by complete Freund adjuvant(CFA),which was divided into normal group,model group,the PLQT 0.16,0.32,0.64 g·kg^-1 group,and the ibuprofen 0.05 g·kg^-1 group(also positive group),give the medicine once a day by gavage.Standard Von Frey fiber was used to evaluated the mechanical pain threshold,acetone was used to stimulated rats inflammatory foot to get the cold-induced response score,with the mechanical pain threshold and cold-induced response score to be observed at 1,2,3,4 and 6 h before and after administration on day 1,and at 4 h after administration on day 3-7.The content of PGE2,IL-1,TNF-αin serum,inflammatory foot and 4-5 lumbar spinal cord was detected by enzyme-linked immunosorbent assay(ELISA).The protein level of MAPKs(pp38,p-ERK,p-JNK)in lumbar spinal cord 4-5 was detected by Western blot.The expression of NF-κB p65 in the lumbar spinal cord was detected by IFA.Result:Model group had lower mechanical pain threshold and higher cold-induced response score than these in normal group(P<0.01),while the mechanical pain threshold and cold-induce response score of the model rats were dose-dependent better regulated after administration of PLQT 0.16,0.32,0.64 g·kg^-1·d^-1(P<0.05,P<0.01),these effect lasted 6 h,of which PLQT groups get the most significant effect on 4 h,however the effect of IBP was similar to that of PLQT medium dose group.In addition,PLQT reduced the abnormal increase of PGE2,IL-1 and TNF-αcontents in serum,inflammatory foot and spinal cord of rats in model group,decreased the protein phosphorylation levels of ERK and JNK in spinal cord,and decreased the protein expression of NF-κB p65,that was significant in the PLQT high-dose group(P<0.01).Conclusion:PLQT had significant analgesic effect on chronic inflammatory pain model rats,which may be related to the inhibition of NF-κB and MAPKs signaling pathways in spinal cord.