RÉSUMÉ
ObjectiveTo investigate the potential mechanism of Xiao Chaihutang （XCHT） in the treatment of Alzheimer's disease （AD） based on network pharmacology and bioinformatics. MethodThe active components of XCHT and corresponding targets were retrieved from Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform （TCMSP）， and the differentially expressed genes related to AD were searched from Gene Expression Omnibus （GEO）. Thereby， the common targets of XCHT and AD were yielded， followed by Gene Ontology （GO） term enrichment and Kyoto Encyclopedia of Genes and Genomes （KEGG） pathway enrichment analysis of the common targets. The component-target network and protein–protein interaction （PPI） network were constructed. Furthermore， amyloid β-protein （Aβ）1-40 was used to induce AD in PC12 cells and then the AD cells were intervened with XCHT. Afterward， cell viability was detected by Cell Counting Kit-8 （CCK-8） assay and cell morphology was observed based on 4'，6-diamidino-2-phenylindole （DAPI） staining. Cell membrane potential was determined and apoptosis was detected by flow cytometry， and cellular immunofluorescence detects the expression of B-cell lymphoma-2 （Bcl-2）/Bcl-2-related X protein （Bax）. Moreover， immunofluorescence assay was performed. ResultA total of 190 active components and 41 anti-AD targets of XCHT were screened out. The key components included mairin， quercetin， berberine， protoporphyrin， 24-ethylcholest-4-en-3-one， and β-D-ribofuranoside， and the core targets were sigma non-opioid intracellular receptor 1 （SIGMAR1）， checkpoint kinase 1 （CHEK1）， protein tyrosine phosphatase non-receptor type 6 （PTPN6）， protein kinase C（PRKCH）， inhibitor of nuclear factor kappa B kinase subunit beta （IKBKB）， cathepsin D （CTSD）， cysteine aspartate protease-3 （Caspase-3）， Bax， and Bcl-2-like protein 1 （Bcl-2L1）. The anti-AD targets of XCHT were involved in 302 GO terms （P < 0.05）， particularly the regulation of neuronal cell apoptosis， and 73 KEGG pathways （P<0.05）. The major pathways and biological processes included the apoptosis pathway， virus infection pathway， lipid and atherosclerosis pathway， and cancer-related pathways. In the in vitro experiment， the model group demonstrated the decrease in cell survival rate （P<0.05）， increase in apoptosis rate （P<0.05）， and down-regulation of mitochondrial membrane potential and Bcl-2/Bax ratio compared with the blank control. Compared with the model group， XCFT group showed the increase in cell survival rate （P<0.05）， decrease in apoptosis rate （P<0.05）， and up-regulation of mitochondrial membrane potential and Bcl-2/Bax ratio. ConclusionBased on network pharmacology， this study reveals the multi-component， multi-target， and multi-pathway characteristics of XCHT in the treatment of AD， laying a foundation for further research on the material basis and mechanism of this prescription.