葛根素通过Nrf2-ARE信号通路抵抗氧化应激对创伤性脑损伤的神经保护作用

目的 探讨葛根素对创伤性脑损伤(TBI)模型大鼠的神经保护作用及脑组织红系衍生的核因子相关因子2(Nrf2)一抗氧化反应原件(ARE)信号通路参与的机制。方法 选择健康成年雄性大鼠体重250～300 g构建TBI模型,将大鼠分为4组:创伤组(A组)、假手术组(B组)、葛根素治疗的创伤组(C组)和葛根素治疗的假手术组(D组); 通过采用改良的神经功能缺损评分(mNSS)评价神经功能,脑组织干湿重称量法评价脑水肿,Nissl染色,TUNEL染色评价脑损伤体积和神经元的凋亡,使用酶活试剂盒检测损伤48 h后抗氧化酶SOD,GSH,和GSSG的活性以及氧化应激产物MDA和NO的水平,最后使用western blot和RT-PCR的方法检测Nrf2-ARE信号通路及其下游分子HO-1,NQO1的表达水平。结果 TBI手术后损伤组mNSS评分明显增高(P<0.05),葛根素治疗组能够明显降低mNSS评分(P<0.05)。TBI手术后损伤组脑水肿加重及神经元凋亡增加(P<0.05),葛根素治疗组能够明显挽救脑水肿及神经元凋亡(P<0.05)。TBI手术12 h后损伤组脑内抗氧化酶SOD,GSH,和GSSG的活性增加及氧化应激产物MDA和NO的水平升高(P<0.05),葛根素治疗组能够明显降低抗氧化酶SOD,GSH,和GSSG的活性以及氧化应激产物MDA和NO的水平(P<0.05)。western blot和RT-PCR显示葛根素不改变Nrf2的翻译和表达,但是RT-PCR显示葛根素能够明显促进Nrf2-ARE信号通路下游分子HO-1,NQO1的表达。结论 葛根素可能通过Nrf2-ARE信号通路抵抗氧化应激对创伤性脑损伤发挥神经保护作用。

Puerarin protects traumatic brain injury through Nrf2-ARE pathway to resist oxidative stress

ObjectiveTo investigate the puerarin protective effect on traumatic brain injury(TBI)model rats through tissue red derivative of nuclear factor related factor 2(Nrf2)antioxidant/electrophilic response element(ARE)signal pathway.Methods TBI model was constructed using healthy adult male rats weigh 250～300 g. Animals were divided into four groups: injury group(group A)and control group(group B), puerarin treatment of injury group(group C), and puerarin treatment of control group(group D). Modified neural function defect scale(mNSS)were used to evaluate neural function, brain wet weight evaluation method was used for the weighing cerebral edema, Nissl staining, TUNEL staining was used to evaluate brain damage volume and neuronal apoptosis. Using enzyme activity kits detect the activities of antioxidant enzymes SOD, GSH, MDA and oxidative stress productor GSSG and NO at 12 hours after injury. Finally using western blot and rt-pcr methods to detect the expression of Nrf2-ARE signaling pathway and its downstream molecular HO-1, NQO1 levels.Results After TBI surgery, mNSS scores were significantly higher(P<0.05), puerarin treatment significantly reduced mNSS score(P<0.05)and improved brain function after TBI. After TBI surgery increased edema and neuronal apoptosis(P<0.05), puerarin treatment group significantly rescued cerebral edema, neuron apoptosis(P<0.05). At 48 h after TBI surgery the activity of antioxidant enzymes SOD, GSH, MDA and oxidative stress product GSSG and NO were increased(P<0.05), puerarin treatment significantly reduced the activities of antioxidant enzymes SOD, GSH, MDA and oxidative stress product GSSG and NO(P<0.05). Western blot and RT-PCR results showed that the puerarin did not change the translation and expression of Nrf2, but the RT-PCR results showed that puerarin significantly enhanced the Nrf2-ARE signaling pathways downstream molecular HO-1, and NQO1.Conclusion Puerarin has protective effect on traumatic brain injury through Nrf2-ARE signaling pathways to resist oxidative stress.