ObjectiveTo investigate the mechanism of Danggui Shaoyaosan （DSS） in the improvement of the cognitive ability of SAMP8 mice with Alzheimer's disease （AD） via regulating the ubiquitin-proteasome pathway （UPP）. MethodFifteen SAMR1 mice were used as a normal group， and 60 SAMP8 mice were randomly divided into a model group and DSS high， medium， and low-dose groups （57.6， 28.8， and 14.4 g·kg^-1·d^-1）， with 15 mice in each group. Intragastric administration was conducted for eight continuous weeks. Place navigation and spatial capacity were evaluated by Morris water maze. Pathological structure changes in neurons in the hippocampal CA1 area was detected by hematoxylin-eosin （HE） staining. The protein expression levels of hippocampal β-amyloid protein（Aβ） and phosphorylation（p）-Tau were determined by immunohistochemical staining （IHC） and enzyme-linked immunosorbent assay （ELISA）， and the mRNA and protein expression levels of hippocampal ubiquitin （Ub）， ubiquitin ligase E3 （E3）， 26S proteasome， ubiquitin carboxyl terminal hydrolase-1 （UCHL1）， and UCHL3 were determined by real-time fluorescent quantitative polymerase chain reaction （Real-time PCR） and Western blot， respectively. ResultAs compared with the normal group， the escape latency was prolonged in the model group （P<0.05） with the reduced number of crossing platform quadrants and time ratio in the platform quadrant （P<0.05）. The model group decreased neurons and condensed cell bodies in the CA1 area， and increased β-amyloid precursor protein （β-APP） and p-Tau positive cells （P<0.05）. In the model group， the protein expression levels of Aβ and p-Tau were increased （P<0.05）， the mRNA and protein expression levels of Ub were increased （P<0.05）， and the mRNA and protein expression levels of E3， 26S proteasome， UCHL1， and UCHL3 were decreased （P<0.05）. As compared with the model group， the escape latency was shortened in the DSS high and medium-dose groups （P<0.05） with an increased number of crossing platform quadrants and residence time ratio （P<0.05）. The pathological changes in CA1 of each DSS group were significantly improved， and the number of β-APP positive staining cells decreased （P<0.05）. The number of p-Tau positive staining cells decreased in the DDS medium and low-dose groups （P<0.05）. The protein expression levels of Aβ and p-Tau in each DDS group decreased （P<0.05）， and the mRNA expression level of Ub in each group decreased （P <0.05）. The mRNA expression levels of 26S， E3， and UCHL3 in the DDS high and medium-dose groups increased （P<0.05）， and the mRNA expression level of UCHL1 in the DDS medium-dose group increased （P<0.05）. The protein expression level of Ub in each DDS group decreased， and the protein expression levels of 26S， E3， UCHL1+3 in the DDS high and medium-dose groups increased （P<0.05）. ConclusionDSS can improve the cognitive ability of SAMP8 mice， and its mechanism may be related to the reduction of the abnormal deposition of Aβ and p-Tau via decreasing the expression of Ub and increasing that of E3， 26S， UCHL1， and UCHL3 in the UPP.

ObjectiveTo investigate the protective effect of Danggui Shaoyaosan （DSS）-contained serum on β-amyloid （Aβ）_1-40-injured rat adrenal pheochromocytoma PC12 cells and its mechanism in regulating ubiquitin-proteasome pathway （UPP）. MethodAβ_1-40 was used to intervene PC12 cells to prepare the cell models of Alzheimer's disease （AD）， and the experiment was divided into the blank， model， and DSS-contained serum high， medium， and low-dose groups （10%， 5%， and 2.5%）. Cell viability and apoptosis were detected using cell counting kit-8 （CCK-8） method and flow cytometry， respectively. The content of Aβ and p-Tau protein was determined by enzyme-linked immunosorbent assay （ELISA）. The ubiquitin （Ub）， ubiquitin ligase E3 （E3）， 26S proteasome， ubiquitin carboxyl terminal hydrolase1 （UCHL1）， and UCHL3 protein expressions of UPP were displayed using immunofluorescence cytochemistry （ICC）， and the mRNA and protein expression levels of Ub， E3-parkin， 26S， UCHL1， and UCHL3 were determined by real-time fluorescent quantitative polymerase chain reaction （Real-time PCR） and Western blot， respectively. ResultThe data of the CCK8 experiment verified that 5 μmol·L^-1 and 48 hours were the optimal conditions for modeling Aβ_1-40-injured PC12 cells. As compared with the blank group， the cell viability rate in the model group decreased （P<0.05） with an increased apoptosis rate （P<0.05）， the content of Aβ and p-Tau contents was elevated （P<0.05）， the mRNA and protein expression levels of Ub increased， and the mRNA and protein expression levels of 26S， E3， and UCHL1+3 decreased （P<0.05）. As compared with the model group， the cell viability rate in the DSS-contained medium-dose group increased （P<0.05）， whereas the apoptosis rate in each DSS-contained group decreased （P<0.05）. The content of Aβ in each DDS-contained group decreased （P<0.05）， and the content of p-Tau in the DDS-contained high and medium-dose groups decreased （P<0.05）. The mRNA expression level of Ub decreased， and that of 26S increased in each DDS-contained group （P<0.05）. The mRNA expression level of UCHL1 in the DDS-contained medium-dose group increased （P<0.05）， and the mRNA expression levels of E3 and UCHL 3 in the DDS-contained high and medium-dose groups increased （P<0.05）. The protein expression level of Ub in each DDS-contained group decreased， and the protein expression levels of 26S， E3， and UCHL1+3 in the DDS high and medium-dose groups increased. The DSS-contained serum medium-dose group exerted the optimal effect. ConclusionDSS-contained serum can increase cell viability rate， reduce cell apoptosis rate， eliminate Aβ and p-Tau protein deposits， and exert protective effects on Aβ_1-40-injured PC12 cells. Its mechanism may involve UPP via decreasing the expression of Ub and increasing that of 26S， E3， UCHL1， and UCHL3.