Modified Xiaoyao San Ameliorates Depression-Like Behaviors and Neuronal Necroptosis in a Mouse Model of Chronic Unpredictable Mild Stress.

Neuronal loss and damage are important pathological features of depression, and necroptosis has been proposed as a potential mechanism of neuronal cell death. Analysis of Gene Expression Omnibus (GEO) datasets (GSE54565, GSE54566, and GSE54568) identified an association between depression and necroptosis, suggesting that inhibition of this pathway may represent a potential therapeutic strategy. Modified Xiaoyao San (MXYS), a modified formulation of the traditional Chinese medicine Xiaoyao San, was developed by incorporating heat-clearing, blood-cooling, cognitive-enhancing, and resuscitation-promoting herbs to improve therapeutic efficacy. However, its effects on neuronal necroptosis and the active constituents reaching brain tissue remain unclear. Ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS) was used to tentatively identify MXYS constituents detected in brain tissue. Therapeutic efficacy was evaluated in a chronic unpredictable mild stress (CUMS) mouse model of depression using behavioral assessments, histological examination, immunofluorescence, western blotting, and bioinformatic analyses. MXYS administration was associated with improved depression-like behaviors, attenuation of pathological brain injury, and reduced phosphorylation of receptor-interacting protein kinase 3 (RIPK3) and mixed lineage kinase domain-like protein (MLKL). These findings suggest that MXYS exerts antidepressant-like effects that are associated with reduced neuronal necroptosis markers, providing experimental support for further investigation of MXYS as a potential therapeutic strategy for depression.