Effects of Xiaoyao San on exercise capacity and liver mitochondrial metabolomics in rat depression model

Abstract

Objective: This study aimed to investigate the therapeutic effects of Xiaoyao San (XYS), a herbal medicine formula, on exercise capacity and liver mitochondrial metabolomics in a rat model of depression induced by chronic unpredictable mild stress (CUMS).

Methods: A total of 24 male SD rats were randomly divided into four groups: control group (C), CUMS control group (M), Venlafaxine positive treatment group (V), and XYS treatment group (X). Depressive behaviour and exercise capacity of rats were assessed by body weight, sugar-water preference test, open field test, pole test, and rotarod test. The liver mitochondria metabolomics were analyzed by using liquid chromatography-mass spectrometry (LC-MS) method. TCMSP database and GeneCards database were used to screen XYS for potential targets for depression, and GO and KEGG enrichment analyses were performed.

Results: Compared with C group, rats in M group showed significantly lower body weight, sugar water preference rate, number of crossing and rearing in the open field test, climbing down time in the pole test, and retention time on the rotarod test (P < 0.01). The above behaviors and exercise capacity indices were significantly modulated in rats in V and X groups compared with M group (P < 0.05, 0.01). Compared with C group, a total of 18 different metabolites were changed in the liver mitochondria of rats in M group. Nine different metabolites and six metabolic pathways were regulated in the liver mitochondria of rats in X group compared with M group. The results of network pharmacology showed that 88 intersecting targets for depression and XYS were obtained, among which 15 key targets such as IL-1β, IL-6, and TNF were predicted to be the main differential targets for the treatment of depression. Additionally, a total of 1 553 GO signaling pathways and 181 KEGG signaling pathways were identified, and the main biological pathways were AGE-RAGE signaling pathway, HIF-1 signaling pathway, and calcium signaling pathway.

Conclusion: XYS treatment could improve depressive symptoms, enhance exercise capacity, positively regulate the changes of mitochondrial metabolites and improve energy metabolism in the liver of depressed rats. These findings suggest that XYS exerts antidepressant effects through multi-target and multi-pathway.

Keywords: Xiaoyao San; depression; exercise capacity; liver; mitochondrial metabolomics.

Fig. 1

Behavioral changes in response to 28-day intervention. (A) Body weight measured weekly; (B) Sugar water preference rate measured at end of intervention period; (C) Number of crossing in open field test measured at end of intervention period; (D) Number of rearing in open field test measured at end of intervention period. ^**P < 0.01 vs C group; ^#P < 0.05, ^##P < 0.01 vs M group.

Fig. 2

Changes in exercise capacity assessed at the end of intervention period. (A) Climbing down time in pole test; (B) Holding time in rotarod test. ^**P < 0.01 vs C group; *P < 0.05, ^##P < 0.01 vs M group.

Fig. 3

Multivariate statistical analysis of mitochondrial metabolomics data. (A) Plots of PLS-DA score for C, M, V, and X groups; (B) Plots of PLS-DA replacement tests for C, M, V, and X groups; (C) Plots of OPLS-DA score for C and M groups; (D) S-plot for C and M groups; (E) OPLS-DA score plots for M and X groups; (F) S-plot for M and X groups.

Fig. 4

Relative peak areas of differential metabolites in rat liver mitochondria. *P < 0.05, ^**P < 0.01 vs C group; ^#P < 0.05, ^##P < 0.01 vs M group.

Fig. 5

Metabolic pathway analysis. (a) Depression-associated metabolic pathways; (b) XYS affected metabolic pathways associated with depression. A. alanine, aspartate, and glutamate metabolism; B. D-glutamine and D-glutamate metabolism; C. phenylalanine, tyrosine, and tryptophan biosynthesis; D. taurine and hypotaurine metabolism; E. phenylalanine metabolism; F. glutathione metabolism; G. citrate cycle (TCA cycle); H. arginine biosynthesis; I. arginine and proline metabolism; J. glycerophospholipid metabolism; K. pyrimidine metabolism; L. purine metabolism; M. glycerolipid metabolism; N. glyoxylate and dicarboxylate metabolism; and O. primary bile acid biosynthesis.

Fig. 6

PPI diagram of potential targets of XYS intervention for depression.

Fig. 7

Histogram of GO enrichment analysis.

Fig. 8

Histogram of KEGG analysis.