黄芪总黄酮联合头穴透刺经Nrf2-Keap1-ARE通路对砷暴露大鼠神经损伤的干预作用

Intervention of total flavonoids of astragalus combined with scalp acupuncture via Nrf2-Keap1-ARE pathway on nerve injury in rats exposed to arsenic

目的 探讨黄芪总黄酮(total flavonoids of astragalus,TFA)联合头穴透刺对砷暴露大鼠神经损伤的治疗作用及其机制。方法 选取SD大鼠50只,随机分为正常对照组、模型组、TFA组(0.02 mg/kg)、头穴透刺组和联合治疗组,每组10只,雌雄各半。构建大鼠砷中毒模型,并进行相应方式治疗。采用改良大鼠神经功能缺损评分(cmodified neurological severity score,mNSS)表对大鼠神经功能评分;Morris水迷宫实验检测大鼠学习和记忆能力;观察大鼠脑组织病理改变;实时荧光定量PCR(quantitative real-time PCR,RT-qPCR)检测大鼠脑组织核因子E2相关因子2(nuclear factor-E2 related factor2,Nrf2)、Kelch样ECH联合蛋白1(recombinant kelch like ECH associated protein 1,Keap1)和超氧化物歧化酶(superoxide dismutase,SOD1)mRNA;蛋白免疫印迹法检测大鼠脑组织Nrf2、p-Nrf2、Keap1、SOD1蛋白水平。结果 病理结果显示,正常对照组大鼠脑组织细胞结构完整、排列整齐,未见出血及水肿,模型组大鼠组织中大量炎性细胞浸润。在治疗后,大鼠脑组织炎性细胞浸润数量降低,联合治疗组降低数量较TFA组和头穴透刺组更明显。与正常对照组比较,建模后大鼠体质量及Keap1m RNA水平显著降低,mNSS评分、p-Nrf2蛋白、Nrf2、SOD1 mRNA和蛋白水平显著升高,差异均有统计学意义(均P<0.05)。治疗后,与模型组比较,砷中毒大鼠体质量Keap1 mRNA水平显著增加,mNSS评分、p-Nrf2蛋白、Nrf2、SOD1 mRNA和蛋白水平显著降低,且联合治疗效果优于TFA和头穴透刺单一治疗,差异均有统计学意义(均P<0.05)。结论 TFA联合头穴透刺可有效治疗砷暴露大鼠的神经损伤,其机制可能与抑制Nrf2的表达及磷酸化,提高SOD1活性,降低机体氧化应激反应有关。

Objective To explore the therapeutic effect and mechanism of total flavonoids of astragalus(TFA) combined with scalp acupuncture on nerve injury in rats exposed to arsenic.Methods Totally 50 SD rats were selected and randomly divided into normal control group,model group,TFA group(0.02 mg/kg),scalp acupuncture group,and combined treatment group,10 rats in each group,half female and half female.A rat model of arsenic poisoning was constructed,and the corresponding treatment was conducted.A modified neurological severity score table was used to score the neurological function of rats.The Morris water maze test was used to detect the learning and memory abilities of rats.The pathological changes of rat brain tissues were observed.The real-time fluorescent quantitative PCR(RT-qPCR) was used to detect the nuclear factor-E2 related factor2(Nrf2),recombinant Kelch like ECH associated protein 1(Keap1) and superoxide dismutase(SOD1) mRNA in rat brain tissues.Western blotting was used to detect the protein levels of Nrf2,p-Nrf2,Keap1,and SOD1 in rat brain tissue.Results The pathological results showed that the structure of brain cells in rats of the normal control group was complete and orderly,and there was no hemorrhage or edema,while a large number of inflammatory cells infiltrated in the model group.After treatment,the number of inflammatory cells infiltration in the brain tissue of rats decreased,and the decrease in the combined treatment group was more obvious than that in the TFA group and scalp acupuncture group.Compared with the normal control group,the body weight and Keap1 mRNA level of the rats after modeling were significantly decreased,while the MNSs score,p-nrf2 protein,Nrf2,SOD1 mRNA and protein levels were significantly increased,and the differences were statistically significant(all P<0.05).After treatment,compared with the model group,the body weight,Keap1 mRNA level of arsenic poisoning rats were significantly increased,the MNSs score,p-nrf2 protein,Nrf2,SOD1 mRNA and protein levels were significantly decreased,the combined treatment had better effect than TFA treatment or scalp acupuncture alone,and the differences were statistically significant(all P<0.05).Conclusion TFA combined with scalp acupuncture can effectively treat the nerve injury in arsenic-exposed rats,and the mechanism may be related to the inhibition of the expression and phosphorylation of Nrf2,increasing the activity of SOD1,and reducing the body’s oxidative stress response.