[Effect of "Xingshen-Jieyu" electroacupuncture on serum differential metabolites in patients with depression based on metabolomics].

Objectives: To explore the effect of "Xingshen-Jieyu" (inducing resuscitation and dispel ling melancholy) electroacupuncture (EA) on serum metabolites in patients with depression and its underlying mechanisms through serum non-targeted metabolomics.

Methods: Fifteen depression patients were subjected into the EA group, and 15 healthy volunteers were matched into the healthy group. EA (2 Hz/15 Hz, a tolerable strength) was applied to Baihui (GV20), Shenting (GV24), Toulinqi (GB15), Benshen (GB13), Touwei (ST8), Xuanli (GB6) and Qubin (GB7) for 30 min, 3 times a week for 6 weeks. The severity of depression was assessed using Hamilton Depression Scale-17 (HAMD-17) and Hamilton Anxiety Scale (HAMA), the degree of fatigue was evaluated using Fatigue Scale-14 (FS-14). The subjects sleep quality was assessed using Pittsburgh sleep quality index (PSQI). Blood samples were collected before and after the treatment for processing serum to perform non-targeted metabolomics profile detection using ultra-high-performance liquid chromatography coupled with mass spectrometry (UPLC-MS), and Partial Least Squares Discriminant Analysis (PLS-DA, a statistical approach). Differential metabolites were screened and pathway enrichment analysis was performed.

Results: After the treatment, the scores of HAMD-17, HAMA, PSQI and FS-14 of depression patients were significantly lowered in the EA group (<0.05). Compared with the healthy subjects, 46 differential metabolites (21 up-regulated, 25 down-regulated) were screened in patients with depression. Compared with pre-treatment in the EA group, 19 differential (17 up-regulated, and 2 down-regulated) metabolites were screened. Four down-regulated metabolites of the 46 differential metabolites in depression patients were recovered after EA treatment. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of differential metabolites before and after EA showed that 19 metabolic pathways were enriched, mainly involving glutaminergic synapses, GABAergic synapses and several amino acid metabolism related pathways.

Conclusions: "Xingshen-Jieyu" EA mainly regulates the metabolism of amino acids, and activities of neurotransmitter glutamate and GABA, and restores the excitatory/inhibitory balance, thus playing a role in improving depression.