Anshen Bunao Syrup alleviates depression on CUMS rats by reducing neuroinflammation: Integral insights from transcriptomics, microbiomics, and metabolomics.

BACKGROUNDAnshen Bunao Syrup (ABS), a traditional Chinese medicinal formula, is widely used to treat neurological disorders such as insomnia, dizziness, and neurasthenia. However, its antidepressant effect and underlying mechanisms remain insufficiently characterized.

PURPOSEThis study aims to comprehensively evaluate the antidepressant effect of ABS in a rat model, and to elucidate the underlying mechanism.

METHODSChronic unpredictable mild stress (CUMS) induced depressive rats were used to evaluate the antidepressant effect of ABS. Histopathological alterations in the hippocampus and colonic mucosa were examined using Nissl and H&E staining. Microglial activation was evaluated by Iba-1 immunohistochemical staining. Gut microbiota composition and metabolic profiles were analyzed using 16S rRNA sequencing and untargeted metabolomics. Differential gene expression and pathway regulation were investigated by transcriptomics and confirmed by Western Blot (WB).

RESULTSABS significantly ameliorated depressive-like behaviors and elevated dopamine and 5-Hydroxytryptamine levels in cortical regions. Furthermore, ABS mitigated hippocampal neuronal damage, suppressed microglial overactivation and reduced oxidative stress in the cortex. 16S rRNA sequencing analysis showed that ABS exerted antidepressant effects via modulation of the "microbiota-gut-brain" axis, particularly by altering intestinal microbiota composition, enhancing gut function, and suppressing HPA axis hyperactivity. Metabolomics revealed that ABS corrected metabolic disturbances, and alleviated inflammation-related metabolic disturbances, while transcriptomics indicated regulation of the Npas4-BDNF-PI3K/AKT signaling pathway, which was further confirmed by WB.

CONCLUSIONABS significantly ameliorated depression in a CUMS rat model, primarily through coordinated regulation of gut microbiota, metabolic homeostasis, and the Npas4-BDNF-PI3K/AKT signaling pathway, providing integrative mechanistic insights into its antidepressant effects.