Wenyang-Tianjing-Jieyu decoction ameliorates Kidney-Yang deficiency type depression-like behavior in Sprague-Dawley rats by enhancing neurogenesis via the FOXO signaling pathway.

Abstract

ETHNOPHARMACOLOGICAL RELEVANCE: Wenyang-Tianjing-Jieyu Decoction (WTJD) is a traditional Chinese herbal formula with a history of ethnopharmacological use for depression, specifically targeting the Kidney-Yang deficiency (KYD) subtype. Its therapeutic rationale is well-documented in classical Chinese materia medica. However, the molecular mechanisms underpinning its clinical efficacy remain largely unelucidated. AIM OF THE STUDY: This study aimed to investigate the therapeutic effects and elucidate the underlying molecular mechanisms of WTJD, a traditional herbal formula, in ameliorating KYD-type depression in a rat model. MATERIALS AND METHODS: The chemical profile of WTJD was characterized using UPLC-Q-Exactive/MS. Using a rat model of KYD-type depression established by combining Phellodendri chinensis Cortex decoction gavage, cold exposure, and chronic unpredictable mild stress (CUMS), we evaluated the therapeutic effects of WTJD. This randomized controlled study included five groups (n = 7/group): Control, Model, Fluoxetine, WTJD-Medium, and WTJD-High, with a 3-week intervention period. Furthermore, we integrated network pharmacology with hippocampal transcriptomics to identify key therapeutic targets, which converged on the FOXO signaling pathway. Finally, the predicted mechanism was validated by assessing key protein phosphorylation, nuclear translocation, hippocampal neurogenesis, and synaptic plasticity. Moreover, the regulatory mechanism was further corroborated in vitro using LPS-induced PC12 cells treated with WTJD-containing serum and the AKT inhibitor MK-2206. RESULTS: WTJD administration significantly ameliorated both the KYD phenotype and depressive-like behaviors in the rat model. Strikingly, both network pharmacology and hippocampal transcriptomic analyses converged on the FOXO signaling pathway as the central therapeutic target. Mechanistically, it was confirmed that WTJD activated the FOXO pathway by inhibiting AKT phosphorylation, which in turn promoted the nuclear translocation of FOXO4. Consistently, in vitro assays demonstrated that WTJD-containing serum protected PC12 cells and rescued downstream gene expression by modulating the FOXO signaling pathway, effects that were mimicked by AKT inhibition. This cascade of molecular events ultimately restored impaired adult hippocampal neurogenesis and synaptic plasticity. CONCLUSION: WTJD ameliorates KYD-type depression by modulating the hippocampal FOXO signaling pathway to restore neurogenesis and synaptic plasticity. These results validate the FOXO pathway as a high-value target for subtype-specific antidepressant drug design.