Chronic Restraint Stress Induced Anxiety And Anxiety-depression Mice Models And The Regulation Effect Of Okra Seeds

Anxiety and depression are characterized by high incidence,high disability rate and high fatality rate,which not only cause serious harm to the patients themselves,but also bring heavy burden to the family and society.Anxiety and depression often co-exist,and patients will suffer from insomnia,pain,fatigue and autonomic nervous dysfunction such as cardiovascular and digestive systems.Existing anti-anxiety and antidepressant drugs take a long time to take effect and may cause serious side effects;To find and develop safer and more effective anti-anxiety and anti-depression drugs in natural plants or functional foods has become a research hotspot.Okra is a functional food with good biological activity.Our previous study found that the water extract of okra seed has the activity of anti-fatigue and improving the depressionlike behavior caused by sleep disturbance.In this study,chronic restraint stress was used to simulate the psychological stress of patients with anxiety and depression,and anxiety and anxiety-depression models were established in mice.Then the models were used to study the anti-anxiety and antidepression effects of okra seeds.Based on the changes of neurotransmitters and tryptophan metabolites in brain-gut axis(hippocampus,serum,colon),the regulatory mechanism of okra seeds on anxiety and anxiety-depression-like behavior in mice was discussed.1.Chronic restraint-induced mice models of anxiety and anxiety-depression were establishedOn the basis of literature studies,the same batch of C57BL/6N mice were first selected for long-term restraint stress,with a daily restraint time of 6h(9:30 to 15:30).In the first,second and fourth week,the elevated plus maze,novelty suppressed feeding test,tail suspension test,forced swimming test were conducted.The results showed that after one and two weeks of restraint,the mice showed anxiety-like behavior but did not show depression-like behavior,while anxiety and depression-like behavior co-existed during the four weeks of restraint.Then,two batches of mice were chronically restrained for one week and four weeks respectively,and behavioral tests related to anxiety and depression were used for detection.The results showed that one week of restraint could reduce the time and duration of entering the open arm of the elevated plus maze and prolong the feeding latency of mice.However,chronic restraint for four weeks can not only reduce the number and duration of mice entering the open arm of the maze,prolong the feeding latency of mice,but also reduce the sucrose preference and prolong the immobility time of mice in the forced swimming test,indicating that chronic restraint for one week and four weeks can establish the anxiety and anxiety-depression models of mice,respectively.2.Chronic restraint induced anxiety and anxiety-depression-like behavior in mice were associated with changes in neurotransmitters and tryptophan metabolites in the hippocampus,serum,and colonThe pro-inflammatory cytokines IL-1ββ,TNF-α,IFN-γ,and neurotransmitters Glu,GABA,E,NE,DA,5-HT in the hippocampus,serum and colon of anxious and anxietydepression mice were determined by ELISA and UPLC-MS/MS.The changes of tryptophan metabolites TRP,KYN,KA,XA,3-HK,QA,5-HT,5-HIAA.The results show that:Chronic restraint for one week and four weeks could increase the levels of IL-1β,TNF-α and IFN-γ in the brain-gut to varying degrees,indicating that restraint for one week and four weeks could lead to the generation of inflammatory.After one week and four weeks of chronic restraint,Glu in the hippocampus of mice was significantly increased,while GABA,DA and NE were significantly decreased,and the change trend of E in hippocampus of two groups of mice was different;Serum NE and 5-HT decreased,while E increased;Glu decreased significantly and GABA increased significantly in colon.Glu was increased in the hippocampus and GABA was decreased in the two batches of mice.In the colon,Glu was decreased,and GABA was increased significantly,suggesting that the changes of neurotransmitters Glu and GABA were different in tissues.Chronic restraint for one and four weeks activated KP metabolism in hippocampus,colon and serum of mice.After four weeks of chronic restraint,3-HK and QA in the hippocampus of mice were significantly increased,while KA was significantly decreased.The changes of metabolites in the hippocampus of mice after one week of chronic restraint were opposite.Tryptophan metabolites in serum of mice with different restraint periods were also different,suggesting that there are periodic differences in KP metabolism in the same tissue.Regardless of one week or four weeks of restraint,TRP in the colon of mice was significantly increased,while 3-HK and QA were significantly decreased,and KA was significantly increased.The levels of 3-HK and QA in the hippocampus of anxietydepression-like mice were significantly increased,while the changes of these metabolites in the colon were opposite,suggesting that the changes of TRP,KA,3-HK and QA in the hippocampus and colon were different in tissue.3.The anti-anxiety and anti-depression effects of okra seeds were studiedOn the basis of demonstrating the antidepressive activity of okra seeds by using acute model,the anti-anxiety and anti-depressive activity of okra seeds were further studied by using established mice models of anxiety and anxiety-depression.After the administration of okra seeds to anxious mice,the length and frequency of entering the open arm in the elevated plus maze could be significantly increased.After the administration of okra seeds,not only the duration and frequency of the open arm,but the surose preference of the mice were increased.These results indicate that okra seeds do have good anti-anxiety and anti-depression activities.4.The possible mechanism of okra anti-anxiety and anti-depression was preliminarily studiedThe regulatory effects of okra seeds on anxiety and anxiety-depression-like behavior were investigated by ELISA and UPLC-MS/MS.The results showed that the okra seeds could reduce the levels of pro-inflammatory factors IL-1β,TNF-α and IFN-y in hippocampus,serum and colon of anxious and anxiety-depression-like mice to varying degrees,increase the content of neuroprotective KA and reduce the content of neurotoxic 3-HK and QA in hippocampus,and increase the neurotransmitters such as NE and DA in hippocampus to resist external stimuli.In addition,okra seeds can significantly increase colon QA and decrease KA in anxiey-depressive mice,to prevent overactivation of TRPKYN pathway.In this study,models of anxiety and anxiety-depression were first established,and inflammatory factors,neurotransmitters and tryptophan metabolites in hippocampus,serum and colon of these models were detected.It was found that neurotransmitters and tryptophan metabolites in anxiety and anxiety-depression mice showed different characteristics of changes.Then,the possible mechanism of okra seeds improving anxiety and anxiety-depression-like behavior in mice was further investigated,and it was found that it may be related to the down-regulation of pro-inflammatory factors,the regulation of neurotransmitter(DA,NE,Glu,GABA)and tryptophan metabolites(KA,3-HK,QA).