The Effect Of Xiaoyao Powder On The Blood Brain Barrier In Vitro Under Chronic Stress And Its Intervention Mechanism

ObjectiveUsing modern experimental techniques such as in vitro cell experiment,molecular biology,serum pharmacology,the changes of protein and mRNA levels of GR and Occludin were studied.This study investigated the effect of Xiaoyao powder on blood brain barrier(BBB)in vitro under chronic stress and its regulatory mechanism.MethodsRBMEC-RA co-cultured cell model was set up,and the BBB stress injury model was induced by corticosterone intervention in vitro.The method of Na-FLU was used to measure the success of BBB model.The successfully constructed BBB model was divided into 6 groups:normal group,model group(Chronic Stress CS),low-dose xiaoyao powder group(CS+low-xys),medium-dose xiaoyao powder group(CS+middle-xys),high-dose xiaoyao powder group(CS+high-xys),and glucocorticoid receptor blocker group(CS+ru-38486).Changes of cell activity,LDH value,TEER value,HRP flow rate,ALP level and-GT level of BBB were calculated by cck-8 assay,transmembrane resistance assay,HRP flow assay,ELISA assay.Protein and mRNA levels of GR and Occludin were detected by western-blot and RT-PCR.Results1.Compared with the single-layer rbmec-bbb model,the permeability of RBMEC-RA co-culture model is lower.In addition,the expression levels of TEER,ALP and-gt in RBMEC-RA co-culture model were higher under normal conditions.2.Under chronic stress,the Cell activity,TEER value,ALP and-gt levels of the BBB were significantly decreased.LDH value and HRP flow were significantly increased.Protein and mRNA levels of GR were decreased in cytoplasm,increased in the nucleus,and Occludin protein and mRNA levels were decreased.3.Xiaoyao powder can increase the cell activity,TEER value,ALP and γ-GT expression levels,and the LDH value and HRP flow were decreased in the Blood brain barrier in chronic stress.Meanwhile,the expression level of GR protein and mRNA in the cytoplasm was increased,while the expression level in the nucleus was decreased.Occludin protein and mRNA expression levels were increased.The effect of Xiaoyao powder at high-dose was close to ru-38486 positive group.ConclusionChronic stress can harm the structure and function of BBB and improve the permeability of BBB.Xiaoyao powder can improve the structure and function of the blood brain barrier in chronic stress.By enhancing GR activity and up-regulating Occludin expression,the structure and function of BBB were improved.Therefore,Xiaoyao powder plays an anti-depression role.