ABSTRACT: Background: Perinatal depression is a prevalent disorder with detrimental effects on both maternal mental health and offspring neurodevelopment. Neuroinflammation mediated by microglial polarization is implicated in its pathogenesis. Oridonin, a natural diterpenoid with anti-inflammatory properties, has shown potential in various disease models, but its efficacy in perinatal depression and its intergenerational impacts remain unexplored. Methods: A mouse model of chronic variable stress (CVS) during lactation was established. Depressive-like behaviors were assessed using the sucrose preference test (SPT), forced swim test (FST), and novelty-suppressed feeding test (NSFT). Stressed dams were randomly assigned to receive daily intraperitoneal injections of oridonin (10 mg/kg), fluoxetine (10 mg/kg), or vehicle for 14 days. Maternal prefrontal cortex (PFC) was analyzed for microglial polarization (via Iba1, iNOS, CD206 immunofluorescence) and cytokine profiles (via Western blot). The offspring's prefrontal cortex and hippocampus were subjected to single-cell RNA sequencing (scRNA-seq) to delineate cell-type-specific transcriptional responses. Results: CVS induced significant depressive-like behaviors in dams, promoted M1 microglial polarization, increased pro-inflammatory cytokines (TNF-α, IL-1β, IL-6), and decreased anti-inflammatory cytokines (IL-4, IL-10, IL-13) in the PFC. Oridonin treatment ameliorated these behavioral deficits, suppressed M1 polarization, enhanced M2 polarization, and normalized cytokine levels, comparable to fluoxetine. scRNA-seq of offspring revealed that oridonin, but not fluoxetine, induced extensive, region-specific transcriptomic reprogramming. Notably, oridonin elicited 220 differentially expressed genes (DEGs) in hippocampal oligodendrocytes, impacted neural circuit-related pathways, and promoted a transcriptional signature associated with synaptic stabilization in the hippocampus while modulating metabolic and stress-response pathways in the prefrontal cortex. Conclusion: Oridonin alleviates maternal depressive-like behaviors by driving microglial polarization toward an anti-inflammatory M2 phenotype and suppressing neuroinflammation. Crucially, maternal oridonin treatment during lactation induces robust, region-specific transcriptional changes in the offspring brain, suggesting a profound intergenerational programming effect. Our findings highlight oridonin's potential as a multi-target therapeutic agent for perinatal depression and its long-lasting impact on offspring neurodevelopment.
