Mechanism Of The Effect Of Xiaoyao San Treatment On Exercise Capacity Of Depressed Rats-A Stable Isotope Tracer Metabolomic Study

Objective:Based on stable isotope tracer metabonomics technology,the specific pathway of Xiaoyao San to improve glucose catabolic disorder in serum of Chronic unpredictable mild stress（CUMS）depressed rats was explored,and combined with the related studies on the ultrastructure and function of skeletal muscle mitochondria,so as to clarify the mechanism of Xiaoyao San to improve the exercise ability of CUMS depressed rats,in order to provide more theoretical reference for the clinical treatment of depression.Methods:（1）48 SD rats were randomly divided into Control group（C）,CUMS group（M）,Venlafaxine group（V）and Xiaoyao San group（X）,with 12 rats in each group.The depression model was established by CUMS stress stimulation for 28 days.Body weight,sugar water preference test,open field test,pole test and rotarod test were used to evaluate the behavior and exercise capacity of the model rats.（2）The ultrastructure of skeletal muscle mitochondria was observed by transmission electron microscopy,and the activity and ATP content of skeletal muscle mitochondrial respiratory chain complexⅠ,Ⅱ,Ⅲ,ⅣandⅤwere determined by ELISA kits.（3）Glucose labeled with stable isotope ¹³C was introduced into rats,LC-MS was used to determine the relevant metabolites in the serum of rats,and the metabolic track of metabolites containing labeled carbon atoms was found in CUMS-induced depressed rats,so as to study the specific pathway of Xiaoyao San in improving glucose catabolism disorder in serum.（4）SPSS software was used for statistical processing and analysis of experimental data,and Graph Pad Prism software was used to generate graphs.Results:（1）After 28 days of modeling,compared with C group,body weight,sugar water preference rate,the number of rearing and the number of crossing in open field test,the falling time of pole test and the time on rod in rotarod test of rats in M group were significantly decreased（P<0.05）.After Xiaoyao San treatment,compared with M group,the above behavioral and exercise capacity results were significantly improved（P<0.05）.（2）Compared with C group,the mitochondria of skeletal muscle in M group were blurred and disordered,with local myolysis,unclear and irregular shape,and most mitochondria showed cavitation phenomenon.After Xiaoyao San treatment,compared with M group,the number of skeletal muscle mitochondria in X group was significantly higher than that in M group,the muscle segments were clear and its structure was relatively complete.Compared with C group,the skeletal muscle mitochondrial ATP content of rats in M group and the activities of respiratory chain complexⅠ,Ⅱ,Ⅲ,ⅣandⅤwere significantly decreased（P<0.05）,and the skeletal muscle mitochondrial ATP content and the activities of respiratory chain complexⅠ,Ⅱ,Ⅲ,ⅣandⅤof rats in X group were significantly increased after administration of Xiaoyao San（P<0.05）.（3）After 28 days of continuous administration of Xiaoyao San,compared with M group,the average serum corticosterone,testosterone,blood lactic acid and serum ammonia in X group were significantly callbacks（P<0.05）.（4）Stable isotope tracer metabolomics showed that ¹³C-labeled metabolites included glycolysis/gluconogenesis,pyruvate metabolism,tricarboxylic acid cycle and other metabolic pathways related to glucose catabolism.Compared with C group,the abundance of pyruvic acid,lactic acid,citric acid,malic acid,glutamic acid and aspartic acid in M group was significantly changed（P<0.05）.Compared with M group,the isotopic signal abundances of pyruvic acid,lactic acid,malic acid,glutamic acid and citric acid in X group were significantly callbacks（P<0.05）.The abundance of related metabolite isotope signals involved in glycolysis,pyruvate metabolism and TCA cycle in serum of depressed rats were abnormal.Conclusion:Xiaoyao San can effectively improve the ultrastructure and dysfunction of skeletal muscle mitochondria in CUMS depressed rats,regulate the serum glycolysis/gluconogenesis,pyruvate metabolism and TCA cycle of depressed rats,and significantly improve the depression-like behavior,exercise ability and fatigue symptoms of CUMS depressed rats,providing a new idea and method for clinical study of depression.