Metabonomic study on chronic unpredictable mild stress and intervention effects of Xiaoyaosan in rats using gas chromatography coupled with mass spectrometry.

ETHNOPHARMACOLOGY Xiaoyaosan (XYS), a famous Chinese prescription, composed of Radix Bupleuri (Bupleurum chinense DC.), Radix Angelicae Sinensis (Angelica sinensis (Oliv.) Diels), Radix Paeoniae Alba (Paeonia lactiflora Pall.), Rhizoma Atractylodis Macrocephalae (Atractylodes macrocephala Koidz.), Poria (Poria cocos (Schw.) Wolf), Radix Glycyrrhizae (Glycyrrhiza uralensis Fisch.), Herba Menthae (Mentha haplocalyx Briq.), and Rhizoma Zingiberis Recens (Zingiber officinale Rosc.), has been widely used in the clinic for treating mental disorders. Behavior and biochemical analyses indicate XYS has obvious anti-depression activity. However, there is no report on the effects of XYS using a metabolomics approach. AIM OF THE STUDY Depression is a prevalent complex psychiatric disorder and its pathophysiological mechanism is not yet well understood. This paper was designed to study metabonomic characters of the depression induced by chronic unpredictable mild stress (CUMS) and the therapeutic effects of XYS, classic traditional Chinese medicine (TCM) in treating the depression. MATERIAL AND METHODS A plasma metabonomics method based on gas chromatography/mass spectrometry (GC/MS) was developed. Principal component analysis (PCA) was utilized to classify and reveal the differences between the model group and control group. In turns, the concentration of these differences was analyzed with t-test to determine whether XYS was possible to influence the metabolic pattern induced by CUMS. RESULTS The significant difference in metabolic profiling was observed from model group compared with drug-dose group by using the PCA, indicating the recovery effect of XYS on CUMS rats. Some significantly changed metabolites like glycine, glucose and hexadecanoic acid have been identified. These biochemical changes are related to the disturbance in amino acid metabolism, energy metabolism and glycometabolism, which are helpful to further understand the CUMS and the therapeutic mechanism of XYS. CONCLUSIONS Metabonomic approach is helpful to further understanding the pathophysiology of depression and assisting in clinical diagnosis of depression and is also a valuable tool for studying the essence of Chinese medicine's syndrome theory and therapeutic effect mechanism of TCM.