Deciphering the polypharmacology of Dingzhi Xiaowan against comorbid depression: Integrated metabolomics of brain tissue and network pharmacology analysis in chronic restraint stress (CRS)-LPS model

Abstract

Ethnopharmacological relevance: Depression represents a prevalent and recurrent neuropsychiatric condition, with emerging evidence implicating glutamate (Glu) receptor dysfunction in the physiological causes of depression. Previous studies have highlighted Dingzhi Xiaowan (DZXW)'s antidepressant properties, attributing them to mechanisms like enhancing monoamine neurotransmitter release and reducing neuroinflammation. Nonetheless, a clearer understanding of how the glutamatergic system influences the antidepressant properties of DZXW remains to be explored.

Aim of the study: This study aimed to elucidate the protective effects and mechanism of DZXW on depressive model mice by integrating metabolomics of brain tissue analysis and network pharmacology study.

Materials and methods: We initially assessed the therapeutic effects of DZXW on depression-like behaviors in mice using the OFT, FST, and SPT. Furthermore, we employed a variety of techniques, including HE and Nissl staining, ELISA, Golgi staining, immunofluorescence, and WB, to investigate how DZXW influences depression-like behaviors in mice. Additionally, we conducted metabolomic analyses and network pharmacology investigations to pinpoint the bioactive metabolites, essential components, and pathways linked to the therapeutic effects of DZXW in treating depression. Subsequently, after administering a TrkB receptor antagonist and an AMPA receptor antagonist, we replicated the behavioral evaluations, along with WB and immunofluorescence staining.

Results: Behavioral assessments demonstrated that DZXW alleviated depression-like symptoms in the mouse CRS + LPS group. Notably, the antidepressant effects of DZXW were linked to a decrease in Glu levels and an improvement in neural synaptic plasticity. Metabolomics research identified 355 differential metabolites, of which DZXW significantly improved the levels of N-Acetylglutamine and N-Acetylaspartylglutamate. Combined with the network pharmacology indicating that components of DZXW, including Ginsenoside Rg1 and Sibiricose A1, may exert therapeutic effects via the glutamate metabolism and mTOR pathway. Furthermore, DZXW enhanced the protein levels of BDNF, TrkB, ERK, mTOR, and GluA1, while concurrently suppressing the expression of GluN1. Significantly, the introduction of TrkB and AMPA receptor antagonists effectively blocked the antidepressant properties of DZXW, indicating a potential crosstalk between the BDNF-TrkB-ERK-mTOR pathway and glutamatergic signaling.

Conclusions: The findings of this study support the idea that DZXW mitigates depression through the pathway associated with glutamate metabolism. Its antidepressant properties largely stem from enhancing the BDNF-TrkB-ERK-mTOR pathway, boosting the expression of AMPA receptors while concurrently inhibiting the expression of N-methyl-d-aspartate (NMDA) receptors. This research serves as a fresh reference point for identifying new antidepressant treatments.

Keywords: BDNF-TrkB-mTOR pathway; Chronic restraint stress; Depression; Dingzhi Xiaowan; Glutamatergic system.