Integration of metabolomics and network pharmacology to validate the mechanism of Schisandra chinensis（Turcz.）Baill - Acorus tatarinowii Schott ameliorating the Alzheimer's disease by regulating the aromatase activity to affect local estrogen in brain of AD model rats

Alzheimer's disease (AD) is a latent and progressive neurodegenerative disease. Schisandra chinensis(Turcz.)Baill - Acorus tatarinowii Schott (Sc-At) are effective in treating neurological disorders. Purpose of this study is to explore the mechanism of Sc-At in AD treatment. First, untargeted ultra-performance liquid chromatography quadrupole-time of flight/mass spectrometer (UPLC-QTOF/MS) metabolomics was employed to detect the rat brain metabolism. Then, network pharmacology was used to determine the potential anti-AD targets. Bioinformatics, and molecular docking were conducted for further analysis. A MetScape study examined the association between differential metabolites and potential targets. Finally, the targeted ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) metabolomics and the potential protein activity studies were carried out to elucidate the mechanisms. The results showed that Sc-At improved the neuronal cell alignment disorder in hippocampal CA1 region of AD rats. In brain metabolomics, 30 differential metabolites were screened in the study model versus blank group. The network pharmacology analyzed 54 targets of Sc-At anti-AD where, 14 were correlated with amyloid β-protein (Aβ). Aromatase was selected as an important hub target having the best binding power in molecular docking simulation predictions and also correlated with Aβ. Further tests showed that the brain aromatase activity, and the downstream product 17β-Estradiol levels were elevated in AD rats treated with Sc-At. This work may provide new perspectives for the pharmacological effects and the action mechanisms of natural compounds extracts in treating AD progression.