Integrated network pharmacology, molecular docking and metabolomics studies to reveal the therapeutic effects of Armillaria gallica extract for treating depression in CUMS-induced mice.

Depression is a common mental disorder and a major contributor to the global burden of mental health issues. Armillaria gallica Marxm. & Romagn (AG), an ancient Chinese herbal medicine, is traditionally used with the protective effect on the central nervous system. However, its antidepressant effect has rarely been reported. The aim of this study is to investigate the potential mechanisms of AG in treating depression based on network pharmacology, molecular docking, serum metabolomics, and experimental validation. The antioxidant assay kits and PC12 and HT-22 cells were used to screen the active extract of AG fermentation. The CUMS-induced depression-like mice were applied to study the antidepressant effects of AG. Then, the integrated approach incorporating network pharmacology, molecular docking, molecular biology, and serum metabolomics was adopted to unravel the pharmacological mechanisms of AG in the treatment of depression. The ethanol part of the water layer of AG (EPWA) exhibits the highest antioxidant and cytoprotective activities which have been selected for further study. Totally, 79 non-volatile compounds were identified from EPWA, and 691 protein targets related to depression were confirmed. Topology analysis conducted on the PPI network identified 11 primary targets. Further non-targeted metabolomics experiments revealed that glycine and serine metabolism, lysine degradation, and arginine biosynthesis are the potential regulatory pathways for AG in the treatment of depression. The web-based pharmacological and serum metabolomic analysis results revealed that IL-6, PTGS2, and PIK3CA are key targets strongly associated with depression, which is consistent with the molecular docking results. Finally, molecular biology experiment results indicated that AG inhibited the protein expression of neuroinflammatory factors such as iNOS, TNF-α, IL-6, PI3KCA, PTGS2, and NLRP3, which may contribute to the protective effects of AG against depression in vivo. AG exerted therapeutic effects on depression by regulating neuroinflammatory response and amino acid metabolism.