[Mechanism of Xiangshao Granules in alleviating anxiety and depression in mice based on integrated metabolomics and gut microbiota].

This study aims to investigate the mechanism through which Xiangshao Granules treat anxiety and depression using metabolomics and gut microbiota techniques, combined with animal experiments. Sixty female ICR mice were selected for the experiment and randomly divided into six groups: a control group, a model group, a low-dose Xiangshao Granules group, a medium-dose Xiangshao Granules group, a high-dose Xiangshao Granules group, and an estradiol(positive drug) group. Except for the control group, rats in other groups were induced for anxiety and depression model by ovariectomy(OVX) combined with chronic unpredictable mild stress(CUMS). After successful modeling, the mice received oral administration of Xiangshao Granules or estradiol for three weeks. Anxiety and depression behaviors in mice were evaluated using light-dark box tests, open field tests, and elevated plus-maze tests. The levels of substances closely related to anxiety and depression, such as serotonin(5-HT) and estrogen(E_2), were quantified in plasma and hippocampal tissue using enzyme-linked immunosorbent assay(ELISA). Metabolomics and 16S rDNA amplicon sequencing techniques were employed to analyze the regulatory effects of Xiangshao Granules on plasma metabolites and metabolic pathways in anxiety and depression mice, as well as their impact on the distribution of gut microbiota. Finally, the correlation between plasma metabolites and differential gut microbiota was constructed using the Spearman correlation coefficient method. Behavioral experimental results indicated that, compared to the control group, the model group exhibited significantly decreased dwell time in the light box, reduced total distance in the open field, and diminished dwell time in the open arm. In contrast, high dose of Xiangshao Granules were found to increase the dwell time in the light box and total distance in the open field. ELISA results indicated that the levels of 5-HT, gamma-aminobutyric acid(GABA), E_2 were significantly decreased, luteinizing hormone(LH), adrenocorticotropic hormone(ACTH), and corticosterone(CORT) were significantly elevated in the anxiety and depression mice, and treatment with middle, high dose of Xiangshao Granules reversed the levels of these substances. Additionally, in the anxiety and depression mouse model, the levels of follicle-stimulating hormone(FSH) were significantly increased, whereas middle, high dose of Xiangshao Granules decreased FSH levels. Metabolomics analysis revealed that Xiangshao Granules significantly changed the metabolic profile of the anxiety and depression mice, affecting central carbon metabolism, amino acid biosynthesis, and ABC transporter pathways. The results from 16S rDNA amplicon sequencing showed that Xiangshao Granules improved the relative abundance of genera such as Bacteroidia, Bacilli, Lactobacillales, and Lactobacillus. Spearman correlation analysis indicated a close association between specific differential gut microbiota and plasma differential metabolites. This study suggests that Xiangshao Granules significantly ameliorate anxiety and depression symptoms in mice by altering the levels of substances associated with these conditions, including 5-HT, GABA, E_2, LH, and ACTH. The metabolomics and gut microbiota data suggest that the therapeutic mechanism may be closely related to the regulation of amino acid biosynthesis, central carbon metabolism, and the alteration of key microbial community compositions.