补肾疏肝方对老年抑郁症小鼠海马氧化应激及TGF-β_(1)/Smad信号通路的影响

Effect of Bushen Shugan Prescription on Oxidative Stress and TGF-β_(1)/Smad Signaling Pathway in Hippocampus of Senile Depressed Mice

目的:观察慢性轻度不可预见性应激(CUMS)后老年抑郁症小鼠海马组织氧化应激和转化生长因子-β_(1)( TGF-β_(1))/Smad信号通路变化,并探讨补肾疏肝方抗抑郁的可能机制。方法:5月龄的小鼠90只,随机分为正常组、模型组、补肾疏肝方高、中、低剂量组和氟西汀组共6组,每组15只。除正常组外,其余各组小鼠均采用CUMS建立老年抑郁症模型。补肾疏肝方高、中、低剂量组小鼠在造模第1天开始同时灌胃补肾疏肝方19.5,9.75,4.87 g·kg^(-1),氟西汀组小鼠灌胃氟西汀0.033 g·kg^(-1),正常组和模型组小鼠灌胃等体积生理盐水,共21 d。用矿场实验评价各组小鼠的行为反应,采集小鼠海马组织并进行相关指标检测,WST-1法测超氧化物歧化酶(SOD)含量,TBA法测丙二醛(MDA)的含量,微量酶标法测谷胱甘肽(GSH)含量,实时荧光定量聚合酶链式反应(Real-time PCR)检测TGF-β_(1),Smad2,Smad3,Smad7 mRNA表达。结果:与正常组比较,模型组小鼠OFT水平得分和垂直得分明显降低,海马组织SOD,GSH水平均下降,MDA含量明显升高(P<0.05);TGF-β_(1),Smad2,Smad3 mRNA表达均上调,Smad7 mRNA表达下调(P<0.05)。与模型组比较,补肾疏肝方高、中、低剂量组及氟西汀组小鼠海马组织SOD,GSH含量均上升,MDA含量下降(P<0.05),补肾疏肝方高、中、低剂量组及氟西汀组小鼠海马组织TGF-β_(1),Smad2,Smad3 mRNA表达均下调,Smad7 mRNA表达上调(P<0.05)。与补肾疏肝方高剂量组比较,补肾疏肝方中、低剂量组小鼠海马组织SOD,GSH含量下降,MDA含量均上升(P<0.05);补肾疏肝方中、低剂量组小鼠海马组织TGF-β_(1),Smad2,Smad3 mRNA表达均上调,Smad7 mRNA表达下调(P<0.05)。结论:补肾疏肝方可显著改善SAPM8小鼠的老年抑郁症状,其机制可能与调节海马氧化应激及TGF-β_(1)/Smad信号通路有关。

Objective:To observe the changes in oxidative stress and transforming growth factor-β_(1)(TGF-β_(1))/Smad signaling pathway in hippocampal tissue of senile depressed mice after chronic unpredictable mild stress and to explore the possible anti-depression mechanism of Bushen Shugan prescription.Method:Ninety five-month-old mice were randomly divided into six groups,namely the normal group,senile depression model group,high-,medium-,and low-dose Bushen Shugan prescription groups,and fluoxetine group,with 15 in each group.Mice in all groups,except for the normal group,were exposed to chronic unpredictable mild stress(CUMS)for inducing the senile depression.Since the first day of modeling,the mice in the high-,medium-and low-dose Bushen Shugan prescription groups were gavaged with 19.5,9.75,4.87 g·kg^(-1) Bushen Shugan prescription,the ones in the fluoxetine group with 0.033 g·kg^(-1) fluoxetine,and those in the normal and senile depression model groups with an equal volume of normal saline for 21 successive days.The behavioral responses of mice in each group were evaluated in the open field test(OFT),and the hippocampal tissues of mice were collected for testing the relevant indexes.The superoxide dismutase(SOD)content was determined by WST-1 method,malondialdehyde(MDA)content by TBA method,glutathione(GSH)content by micro enzyme-linked immunosorbent assay(ELISA),and mRNA expression of TGF-β_(1),Smad2,Smad3,and Smad7 by Real-time polymerase chain reaction(Real-time PCR).Result:Compared with the normal group,the senile depression model group exhibited significantly lowered horizontal and vertical scores in OFT,decreased SOD and GSH contents in hippocampal tissues,elevated MDA(P<0.05),up-regulated TGF-β_(1),Smad2,and Smad3 mRNA expression,and down-regulated Smad7(P<0.05).Compared with the senile depression model group,Bushen Shugan prescription at the high,medium,and low doses and fluoxetine all increased SOD and GSH contents in mouse hippocampal tissues,decreased the MDA content(P<0.05),down-regulated the mRNA expression of TGF-β_(1),Smad2,and Smad3 in hippocampal tissues,and up-regulated the Smad7 mRNA expression(P<0.05).The comparison with the high-dose Bushen Shugan prescription group showed that the SOD and GSH contents in hippocampal tissues of mice in the medium-and low-dose Bushen Shugan prescription groups declined significantly,while the MDA contents rose significantly(P<0.05).Besides,the mRNA expression levels of TGF-β_(1),Smad2 and Smad3 in the hippocampal tissues of mice in the medium-and low-dose Bushen Shugan prescription groups were significantly up-regulated,and those of Smad7 were significantly down-regulated(P<0.05).Conclusion:Bushen Shugan prescription alleviates the depression symptoms in aged SAPM8 mice possibly by regulating the hippocampal oxidative stress and TGF-β_(1)/Smad signaling pathway.