Impact of traditional Chinese medicine treatment on chronic unpredictable mild stress-induced depression-like behaviors: intestinal microbiota and gut microbiome function

Antidepressant-like effects of hyperoside on chronic stress-induced depressive-like behaviors in mice: Gut microbiota and short-chain fatty acids

BACKGROUND

The antidepressant effect of hyperoside (HYP), which is the main component of Hypericum perforatum, is not established. This study aimed to determine the effects of HYP on depression.

METHODS

The antidepressant-like effect of HYP was studied in mice induced by chronic restraint stress (CRS). The effects of HYP on behavior, inflammation, neurotransmitters, gut microbiota, and short-chain fatty acids (SCFAs) were studied in CRS mice.

RESULTS

HYP improved depressive-like behavior in mice induced by CRS. Nissl staining analysis showed that HYP improved neuronal damage in CRS mice. Western blot (WB) analysis showed that HYP increased the expression levels of BDNF and PSD95 in the hippocampus of CRS mice. The results of ELISA showed that HYP down-regulated the expression levels of IL-6, IL-1β, TNF-α, and CORT in the hippocampus, blood, and intestinal tissues of mice and up-regulated the expression levels of 5-HT and BDNF. Hematoxylin and eosin (HE) staining results indicate that HYP can improve the intestinal histopathological injury of CRS mice. The results of 16S rRNA demonstrated that HYP attenuated the dysbiosis of the gut microbiota of depressed mice, along with altering the concentration of SCFAs.

LIMITATIONS

In the present study, direct evidence that HYP improves depressive behaviors via gut microbiota and SCFAs is lacking, and only female mice were evaluated, which limits the understanding of the effects of HYP on both sexes.

CONCLUSIONS

HYP can improve CRS-induced depressive-like behaviors in mice, which is associated with regulating the gut microbiota and SCFAs concentration.

Zhi-zi-chi decoction mitigates depression by enhancing lncRNA Six3os1 expression and promoting histone H3K4 methylation at the BDNF promoter

Traditional Chinese medicine, particularly Zhi-zi-chi decoction (ZZCD), is gaining recognition as a potential treatment for depression. This study aimed to uncover the molecular mechanisms behind ZZCD's antidepressant effects, focusing on lncRNA Six3os1 and histone H3K4 methylation at the BDNF promoter. Network pharmacology and in vivo experiments were conducted to identify ZZCD targets and evaluate its impact on depression-related behaviours and neuron injury. The role of Six3os1 in recruiting KMT2A to the BDNF promoter and its effects on oxidative stress and neuron injury were investigated. ZZCD reduced depression-like behaviours and neuron injury in mice subjected to chronic stress. It upregulated Six3os1, which facilitated KMT2A recruitment to the BDNF promoter, leading to increased histone H3K4 methylation and enhanced BDNF expression. ZZCD also inhibited CORT-induced neuron injury, inflammatory response and oxidative stress in vitro. ZZCD's antidepressant properties involve Six3os1 upregulation, which exerts neuroprotective effects by inhibiting oxidative stress and neuron injury, thereby alleviating depressive symptoms. Targeting Six3os1 upregulation may offer a potential therapeutic intervention for depression.

Chronically socially isolated mice exhibit depressive-like behavior regulated by the gut microbiota

Objectives

Chronic loneliness is a widespread issue, and the gut-brain axis is known to be crucial in facilitating communication between the gut and brain. However, the precise mechanism by which chronic loneliness affects the gut-brain axis remains uncertain.

Methods

Fourteen 55-week-old Balb/c mice were used in the experiment, with seven mice being randomly assigned to the chronic social isolation (CSI) group. The CSI group mice underwent 12 weeks of isolation to simulate the psychiatric state of a population in prolonged social isolation. The mental state of the CSI mice was assessed through animal behavior analysis, while plasma cytokines were measured using ELISA. Additionally, the composition of the gut microbiota was analyzed using 16S rRNA sequencing, and the metabolite composition of the intestinal contents was examined using nontargeted metabolomics. The Student-T test was used to determine significant mean differences.

Results

Mice that were exposed to the CSI exhibited increased immobility time lengths in forced swimming and hanging tail experiments, and decreased movement lengths and number of times traversing the intermediate region, compared to control mice. Additionally, CSI decreased the abundance of the probiotics Ruminococcaceae, Akkermansiaceae, and Christensenellaceae. Additionally, CSI reduced the production of the metabolites oleamide and tryptophan. Furthermore, IL-1β, IL-4, and IL-6 were significantly increased, while TNF-α was significantly decreased.

Conclusion

CSI induces a dysbiotic gut microbiota and the production of neurorelated metabolites, which in turn increase inflammatory responses and result in depressive behaviors in CSI mice. Therefore, these findings suggest that the gut microbiota may serve as a target for the treatment of long-term social isolation-induced mental disorders.

The Role of Cdo1 in Ferroptosis and Apoptosis in Cancer

Cysteine dioxygenase type 1 (Cdo1) is a tumor suppressor gene. It regulates the metabolism of cysteine, thereby influencing the cellular antioxidative capacity. This function puts Cdo1 in a prominent position to promote ferroptosis and apoptosis. Cdo1 promotes ferroptosis mainly by decreasing the amounts of antioxidants, leading to autoperoxidation of the cell membrane through Fenton reaction. Cdo1 promotes apoptosis mainly through the product of cysteine metabolism, taurine, and low level of antioxidants. Many cancers exhibit altered function of Cdo1, underscoring its crucial role in cancer cell survival. Genetic and epigenetic alterations have been found, with methylation of Cdo1 promoter as the most common mutation. The fact that no cancer was found to be caused by altered Cdo1 function alone indicates that the tumor suppressor role of Cdo1 is mild. By compiling the current knowledge about apoptosis, ferroptosis, and the role of Cdo1, this review suggests possibilities for how the mild anticancer role of Cdo1 could be harnessed in new cancer therapies. Here, developing drugs targeting Cdo1 is considered meaningful in neoadjuvant therapies, for example, helping against the development of anti-cancer drug resistance in tumor cells.

Microbiota-Induced Epigenetic Alterations in Depressive Disorders Are Targets for Nutritional and Probiotic Therapies

Major depressive disorder (MDD) is a complex disorder and a leading cause of disability in 280 million people worldwide. Many environmental factors, such as microbes, drugs, and diet, are involved in the pathogenesis of depressive disorders. However, the underlying mechanisms of depression are complex and include the interaction of genetics with epigenetics and the host immune system. Modifications of the gut microbiome and its metabolites influence stress-related responses and social behavior in patients with depressive disorders by modulating the maturation of immune cells and neurogenesis in the brain mediated by epigenetic modifications. Here, we discuss the potential roles of a leaky gut in the development of depressive disorders via changes in gut microbiota-derived metabolites with epigenetic effects. Next, we will deliberate how altering the gut microbiome composition contributes to the development of depressive disorders via epigenetic alterations. In particular, we focus on how microbiota-derived metabolites such as butyrate as an epigenetic modifier, probiotics, maternal diet, polyphenols, drugs (e.g., antipsychotics, antidepressants, and antibiotics), and fecal microbiota transplantation could positively alleviate depressive-like behaviors by modulating the epigenetic landscape. Finally, we will discuss challenges associated with recent therapeutic approaches for depressive disorders via microbiome-related epigenetic shifts, as well as opportunities to tackle such problems.

Ginkgo biloba Extract Drives Gut Flora and Microbial Metabolism Variation in a Mouse Model of Alzheimer's Disease

Alzheimer's disease (AD) is a complex neurodegenerative disease. Numerous investigations have demonstrated that medications that regulate the "brain-gut" axis can ameliorate disease symptoms of AD. Studies have shown that Ginkgo biloba extract (EGb) is involved in intestinal metabolism to meet the goal of illness treatment. EGb is currently utilized extensively in the clinical prevention and treatment of cardiovascular and cerebrovascular diseases. However, the regulatory effect of EGb on intestinal flora and its metabolites in AD pathology remains largely speculative. In this study, the Morris water maze test showed a significant improvement of spatial memory in the AD mouse model (APP/PS1 mice) after EGb treatment. We next confirmed the positive effects of EGb on the gut flora and metabolites of APP/PS1 mice and further showed that EGb treatment reshaped the disturbed gut microbiome, in particular by reducing the Firmicutes/Bacteroides ratio and increasing the abundance of Bacteroidetes, Uroviricota, Streptophyta, and Spirochaetes. Meanwhile, a non-targeted metabolomics analysis showed that EGb treatment significantly reversed the dysfunction of the microbial metabolic phenotype by altering Limosilactobacillus and Parvibacte, with 300 differential metabolites modulated (131 up-regulated, 169 down-regulated). Our findings highlight the significant regulatory impact of EGb on intestinal microflora and microbial metabolism in AD mice models and provide a potential therapeutic strategy for AD.

The impact of acute and chronic stress on gastrointestinal physiology and function: a microbiota-gut-brain axis perspective

The physiological consequences of stress often manifest in the gastrointestinal tract. Traumatic or chronic stress is associated with widespread maladaptive changes throughout the gut, although comparatively little is known about the effects of acute stress. Furthermore, these stress-induced changes in the gut may increase susceptibility to gastrointestinal disorders and infection, and impact critical features of the neural and behavioural consequences of the stress response by impairing gut-brain axis communication. Understanding the mechanisms behind changes in enteric nervous system circuitry, visceral sensitivity, gut barrier function, permeability, and the gut microbiota following stress is an important research objective with pathophysiological implications in both neurogastroenterology and psychiatry. Moreover, the gut microbiota has emerged as a key aspect of physiology sensitive to the effects of stress. In this review, we focus on different aspects of the gastrointestinal tract including gut barrier function as well as the immune, humoral and neuronal elements involved in gut-brain communication. Furthermore, we discuss the evidence for a role of stress in gastrointestinal disorders. Existing gaps in the current literature are highlighted, and possible avenues for future research with an integrated physiological perspective have been suggested. A more complete understanding of the spatial and temporal dynamics of the integrated host and microbial response to different kinds of stressors in the gastrointestinal tract will enable full exploitation of the diagnostic and therapeutic potential in the fast-evolving field of host-microbiome interactions.

From-Toilet-to-Freezer: A Review on Requirements for an Automatic Protocol to Collect and Store Human Fecal Samples for Research Purposes

The composition, viability and metabolic functionality of intestinal microbiota play an important role in human health and disease. Studies on intestinal microbiota are often based on fecal samples, because these can be sampled in a non-invasive way, although procedures for sampling, processing and storage vary. This review presents factors to consider when developing an automated protocol for sampling, processing and storing fecal samples: donor inclusion criteria, urine-feces separation in smart toilets, homogenization, aliquoting, usage or type of buffer to dissolve and store fecal material, temperature and time for processing and storage and quality control. The lack of standardization and low-throughput of state-of-the-art fecal collection procedures promote a more automated protocol. Based on this review, an automated protocol is proposed. Fecal samples should be collected and immediately processed under anaerobic conditions at either room temperature (RT) for a maximum of 4 h or at 4 °C for no more than 24 h. Upon homogenization, preferably in the absence of added solvent to allow addition of a buffer of choice at a later stage, aliquots obtained should be stored at either -20 °C for up to a few months or -80 °C for a longer period-up to 2 years. Protocols for quality control should characterize microbial composition and viability as well as metabolic functionality.

Molecular basis of breast cancer with comorbid depression and the mechanistic insights of Xiaoyaosan in treating breast cancer-associated depression

Depression and breast cancer (BC) have been found to have a shared genetic basis, multiple loci of effect, and a presumed causal relationship. The treatment of BC combined with depression poses significant challenges. This study aims to use bioinformatics and network pharmacology to explore the molecular basis of BC combined with depression and to elucidate the potential mechanisms of Xiaoyaosan (XYS) in treating this disease. The molecular background of BC complicated with depression was discovered via data mining and bioinformatics. The molecular mechanism of XYS in the treatment of BC with depression was investigated by network pharmacology. The binding affinity between targets and active compounds was evaluated by molecular docking. The impact of XYS on the gene and protein expression of matrix metallopeptidase 9 (MMP9) in microglial cells was assessed using RT-quantitative PCR and western blot analysis, respectively. Differential expression analysis was conducted to identify genes associated with BC, revealing that 2958 genes were involved, with 277 of these genes also being related to depression. XYS was found to contain 173 active compounds and 342 targets, with 44 of these targets being involved in regulating the progression of BC and depression. Enrichment analysis was performed to identify pathways associated with these targets, revealing that they were related to cell proliferation, catalytic activity, cell communication, and interleukin-18 signaling and LXR/RXR activation. Network analysis was conducted to identify key targets of Xiaoyaosan in treating BC combined with depression, with EGF, interleukin 6, epidermal growth factor receptor, and peroxisome proliferator activated receptor gamma being identified as important targets. Molecular docking was also performed to assess the binding affinity between key targets and active compounds, with puerarin showing the strongest affinity for MMP9. In microglial cells, XYS significantly enhances the gene and protein expression of MMP9. This study elucidated the pharmacological mechanism of co-treatment for BC patients complicated with depression and the pharmacological mechanism of XYS against BC plus depression.

Liver function test indices-based prediction model for post-stroke depression: a multicenter, retrospective study

BACKGROUND

Post-stroke depression (PSD) was one of the most prevalent and serious neuropsychiatric effects after stroke. Nevertheless, the association between liver function test indices and PSD remains elusive, and there is a lack of effective prediction tools. The purpose of this study was to explore the relationship between the liver function test indices and PSD, and construct a prediction model for PSD.

METHODS

All patients were selected from seven medical institutions of Chongqing Medical University from 2015 to 2021. Variables including demographic characteristics and liver function test indices were collected from the hospital electronic medical record system. Univariate analysis, least absolute shrinkage and selection operator (LASSO) and logistic regression analysis were used to screen the predictors. Subsequently, logistic regression, random forest (RF), extreme gradient boosting (XGBoost), gradient boosting decision tree (GBDT), categorical boosting (CatBoost) and support vector machine (SVM) were adopted to build the prediction model. Furthermore, a series of evaluation indicators such as area under curve (AUC), sensitivity, specificity, F1 were used to assess the performance of the prediction model.

RESULTS

A total of 464 PSD and 1621 stroke patients met the inclusion criteria. Six liver function test items, namely AST, ALT, TBA, TBil, TP, ALB/GLB, were closely associated with PSD, and included for the construction of the prediction model. In the test set, logistic regression model owns the AUC of 0.697. Compared with the other four machine learning models, the GBDT model has the best predictive performance (F1 = 0.498, AUC = 0.761) and was chosen to establish the prediction tool.

CONCLUSIONS

The prediction model constructed using these six predictors with GBDT algorithm displayed a promising prediction ability, which could be used for the participating hospital units or individuals by mobile phone or computer.

Antidepressant-like effects of geniposide in chronic unpredictable mild stress-induced mice by regulating the circ_0008405/miR-25-3p/Gata2 and Oip5os1/miR-25-3p/Gata2 networks

Evidence exists suggesting the anti-depressive activities of geniposide (GP), a major compound in Gardenia jasminoides Ellis. Accordingly, the present study attempts to explore the anti-depressive mechanism of GP in chronic unpredictable mild stress (CUMS)-induced depression-like behaviors of mice. CUMS-induced mice were given GP daily and subjected to behavioral tests to observe the effect of GP on the depression-like behaviors. It was noted that GP administration reduced depression-like behaviors in CUMS mice. Transcriptome sequencing was conducted in three control and three CUMS mice. Differentially expressed circRNAs, lncRNAs and mRNAs were then screened by bioinformatics analyses. Intersection analysis of the transcriptome sequencing results with the bioinformatics analysis results was followed to identify the candidate targets. We found that Gata2 alleviated depression-like behaviors via the metabolism- and synapse-related pathways. Gata2 was a target of miR-25-3p, which had binding sites to circ_0008405 and Oip5os1. circ_0008405 and Oip5os1 competitively bound to miR-25-3p to release the expression of Gata2. GP administration ameliorated depression-like behaviors in CUMS mice through regulation of the circ_0008405/miR-25-3p/Gata2 and Oip5os1/miR-25-3p/Gata2 crosstalk networks. Taken together, GP may exert a potential antidepressant-like effect on CUMS mice, which is ascribed to regulation of the circ_0008405/miR-25-3p/Gata2 and Oip5os1/miR-25-3p/Gata2 crosstalk networks.

Fermented Wheat Germ Alleviates Depression-like Behavior in Rats with Chronic and Unpredictable Mild Stress

Depression is a chronic mental illness with devastating effects on a person's physical and mental health. Studies have reported that food fermentation with probiotics can enrich the nutritional values of food and produce functional microorganisms that can alleviate depression and anxiety. Wheat germ is an inexpensive raw material that is rich in bioactive ingredients. For example, gamma-aminobutyric acid (GABA) is reported to have antidepressant effects. Several studies concluded that Lactobacillus plantarum is a GABA-producing bacteria and can alleviate depression. Herein, fermented wheat germs (FWGs) were used to treat stress-induced depression. FWG was prepared by fermenting wheat germs with Lactobacillus plantarum. The chronic unpredictable mild stress (CUMS) model was established in rats, and these rats were treated with FWG for four weeks to evaluate the effects of FWG in relieving depression. In addition, the study also analyzed the potential anti-depressive mechanism of FWG based on behavioral changes, physiological and biochemical index changes, and intestinal flora changes in depressed rats. The results demonstrated that FWG improved depression-like behaviors and increased neurotransmitter levels in the hippocampus of CUMS model rats. In addition, FWG effectively altered the gut microbiota structure and remodeled the gut microbiota in CUMS rats, restored neurotransmitter levels in depressed rats through the brain-gut axis, and restored amino acid metabolic functions. In conclusion, we suggest that FWG has antidepressant effects, and its potential mechanism may act by restoring the disordered brain-gut axis.

Ingestion of Lacticaseibacillus rhamnosus Fmb14 prevents depression-like behavior and brain neural activity via the microbiota-gut-brain axis in colitis mice

Large preclinical evidence suggested that colitis was one of the risk factors for depression and probiotics were effective therapeutic agents to prevent the disease. The effect of Lacticaseibacillus rhamnosus Fmb14 on colitis-related depression-like behavior and its possible mechanisms were investigated. One week of DSS exposure led to the following changes in male C57BL/6N mice: a reduction in the movement distance from 2218 to 1299 cm, time in central areas from 23.6 s to 11.5 s, and time in the bright box from 217 s to 103 s, which were restored to 1816 cm, 18.4 s, and 181 s, respectively, with preadministration of Fmb14 for 8 weeks. All improvements provided by Fmb14 indicated a remarkable protective effect on depression-like behavior. Fmb14 first worked to repair intestinal barrier damage and the inflammatory response in the colon through ZO1 and Ocln enhancement and IL-1β, NF-κB and IL-6 reduction, respectively. Second, dysbiosis of the gut microbiota was modulated by Fmb14, including reduction of Akkermansia (18.9% to 5.4%), Mucispirillum (0.6% to 0.1%) and Bifidobacterium (0.32% to 0.03%). Fmb14 supplementation ameliorates the brain inflammatory response via IL-18 and NF-κB reduction and improves the blood-brain barrier via increased levels of ZO1 and Ocln. Moreover, brain activity was facilitated by an increase in BDNF and dopamine and the downregulation of GABA in the Fmb14 group. As a consequence of the modulatory effect on the dysfunction of neurotransmitters and neuroinflammation, Fmb14 prevents neurodegeneration by inhibiting neuronal apoptosis and Nissl edema. In addition, the correlation analysis further demonstrated the preventative effect of Fmb14 on depression-like behavior through the microbiota-gut-brain axis. Together, these findings demonstrated the important role of Fmb14 in biological signal transduction over the microbiota-gut-brain axis to improve mood disorders.

Gut microbiota mediates the pharmacokinetics of Zhi-zi-chi decoction for the personalized treatment of depression

ETHNOPHARMACOLOGICAL RELEVANCE

Zhi-zi-chi decoction (ZZCD), from "Treatise on Febrile Diseases", is a typical traditional Chinese medicine herb pair, which consists of Gardeniae Fructus (GF) and Semen Sojae Praeparatu (SSP). In clinical research, ZZCD was widely used to fight depression, remove annoyance. Many studies have reported that gut microbiota is critical target for the influence of depress through gut-brain axis, and our previously studies have found that ZZCD exhibiting antidepressant effect was through the gut-brain axis. However, the specific mechanism by which gut microbiota mediates the pharmacokinetics parameters of active compounds from ZZCD during the process of depression treatment has not yet been studied.

AIM OF THE STUDY

To explore the differences in pharmacokinetics characters of bioactive iridoids from ZZCD and study the changes of gut microbiota at different stages of depression with the personalized medicine of ZZCD.

MATERIALS AND METHODS

A new strategy exploring the relationship among disease phenotypes (D), intestinal microbiota (I), enzymes (E) and traits of metabolism (T) named as "DIET" was established. Firstly, a fast, selective and sensitive ultra-performance liquid chromatography coupled with tandem mass spectrometer (UPLC-MS/MS) was established and validated to quality the main bioactive compounds from ZZCD and compare the pharmacokinetics and bioavailability of different iridoids prototypes and metabolites from ZZCD between normal and chronic unpredictable mild stress rats. Subsequently, the activity of corresponding metabolic enzymes of anti-depressive compounds, β-glucosidases and sulfotransferases, were analyzed by ρ-nitrophenyl-β -D-glucopyranoside and sulfotransferases ELISA kits, respectively. Finally, 16S rRNA gene sequencing was adopt to analyze intestinal bacteria composition for the treatment of depression by ZZCD.

RESULTS

The antidepressant effect of ZZCD was promoted due to the increased exposures and reduced eliminations of anti-depressive compounds, especially geniposide and genipin 1-gentiobioside, under the depression state. With the ZZCD treatment, the depression was improved, but the exposures of anti-depressive compounds from ZZCD gradually decreased. Meanwhile, there were the corresponding decreased trends on the activity of β-glucosidases and sulfotransferases. With the consumption of ZZDC and the improvement of depression, the exposures of anti-depressive iridoid glycosides decreased and the activity of metabolism enzymes restored. Meanwhile, the dysbiosis of pathogenic bacteria (Bacteroidota) induced by depression was ameliorated and the probiotics (Firmicutes) at the phylum and genus level raised, the two phyla are closely related to the production of β-glucosidase and sulfotransferases.

CONCLUSIONS

It is the first proposed that ZZCD could personalized to treat depression at different stages targeting gut microbiota and gut microbiome could emerged as a potential diagnostic and therapeutic biomarker in depression.

Leonurine Regulates Hippocampal Nerve Regeneration in Rats with Chronic and Unpredictable Mild Stress by Activating SHH/GLI Signaling Pathway and Restoring Gut Microbiota and Microbial Metabolic Homeostasis

Depression is a highly prevalent and heterogeneous disorder that requires new strategies to overcome depression. In this study, we aimed to investigate whether leonurine modulated hippocampal nerve regeneration in chronic and unpredictable mild stress (CUMS) rats through the SHH/GLI signaling pathway and restoring gut microbiota and microbial metabolic homeostasis. The CUMS rat model was constructed and treated with leonurine. The body weight of rats was recorded, and a series of tests were performed. Western blot was utilized to measure the expression of BDNF and 5-HT in the hippocampus. Then the expression of SHH, GLI, PTCH, and SMO were measured by qRT-PCR and western blot. The colocalization of BrdU+DCX and BrdU+NeuN was evaluated by IF. 16S rDNA high-throughput sequencing was applied to detect the composition and distribution of gut microbiota. The differential metabolites were analyzed by untargeted metabolomics. The correlation between gut microbiota and microbial metabolites was analyzed by Pearson correlation coefficient. After CUMS modeling, the body weight of rats was decreased, and the expression of BDNF and 5-HT were decreased, while the body weight was recovered, and the expression of BDNF and 5-HT were increased after leonurine treatment. Leonurine reversed the reduction in the colocalization of BrdU+DCX and BrdU+NeuN and the reduction in the levels of SHH, GLI, PTCH, and SMO induced by CUMS modeling. Leonurine also restored gut microbiota and microbial metabolites homeostasis in CUMS rats. Furthermore, Prevotellaceae_Ga6A1_group was negatively correlated with 3-Oxocholic acid, nutriacholic acid, and cholic acid. Collectively, leonurine regulated hippocampal nerve regeneration in CUMS rats by activating the SHH/GLI signaling pathway and restoring gut microbiota and microbial metabolic homeostasis.

Microbiota alteration of Chinese young male adults with high-status negative cognitive processing bias

Introduction

Evidence suggests that negative cognitive processing bias (NCPB) is a significant risk factor for depression. The microbiota-gut-brain axis has been proven to be a contributing factor to cognitive health and disease. However, the connection between microbiota and NCPB remains unknown. This study mainly sought to explore the key microbiota involved in NCPB and the possible pathways through which NCPB affects depressive symptoms.

Methods

Data in our studies were collected from 735 Chinese young adults through a cross-sectional survey. Fecal samples were collected from 35 young adults with different levels of NCPB (18 individuals were recruited as the high-status NCPB group, and another 17 individuals were matched as the low-status NCPB group) and 60 with different degrees of depressive symptoms (27 individuals were recruited into the depressive symptom group, as D group, and 33 individuals were matched into the control group, as C group) and analyzed by the 16S ribosomal RNA sequencing technique.

Results

As a result, the level of NCPB correlated with the degree of depressive symptoms as well as anxiety symptoms and sleep quality (p < 0.01). The β-diversity of microbiota in young adults was proven to be significantly different between the high-status NCPB and the low-status NCPB groups. There were several significantly increased bacteria taxa, including Dorea, Christensenellaceae, Christe -senellaceae_R_7_group, Ruminococcaceae_NK4A214_group, Eggerthellaceae, Family-XIII, Family_XIII_AD3011_group, Faecalibaculum, and Oscillibacter. They were mainly involved in pathways including short-chain fatty acid (SCFA) metabolism. Among these variable bacteria taxa, Faecalibaculum was found associated with both NCPB and depressive symptoms. Furthermore, five pathways turned out to be significantly altered in both the high-status NCPB group and the depressive symptom group, including butanoate metabolism, glyoxylate and dicarboxylate metabolism, propanoate metabolism, phenylalanine, tyrosine, and tryptophan biosynthesis, valine, leucine, and isoleucine degradation. These pathways were related to SCFA metabolism.

Discussion

Fecal microbiota is altered in Chinese young male adults with high status NCPB and may be involved in the biochemical progress that influences depressive symptoms.

Factors affecting the use of herbal medicines for weight loss in overweight and obese adolescents

Objectives

Herbal medicine (HM) is widely used to treat obesity in adolescents worldwide since the currently available interventions have low compliance and lack long-term effects and safety data. This study aimed to analyze the factors affecting HM use for weight loss in overweight and obese adolescents.

Methods

A total of 46,336 adolescents were included in this cross-sectional study based on the Korea Youth Risk Behavior Web-Based Survey. Three models of HM use for weigh loss were developed by sequentially adding predisposing, enabling, and need factors according to Andersen's model using multiple logistic regression analyses considering the complex sampling design.

Results

Male and female high school students and students from low perceived household economic status were less likely to use HM for weight loss. Students whose fathers had a college degree or higher, depressed mood, and two or more chronic allergic diseases were more likely to use HM. Male students who perceived their body image as fat or very fat tended to use HM less than those who perceived their body image as very thin, thin, or moderate. Obese female students tended to use HM more than overweight female students.

Conclusion

These results can be used as the bases to promote HM use, provide ideas for future research, and strengthen the health insurance coverage extension for weight loss interventions.

Antidepressants amitriptyline, fluoxetine, and traditional Chinese medicine Xiaoyaosan caused alterations in gut DNA virome composition and function in rats exposed chronic unpredictable mild stress

Background

In clinical practice, antidepressant drugs are widely used to treat depression. Previous studies have attention to the impact of antidepressants on the bacterial microbiome, while the role of these drugs in the gut virome is still unclear.

Methods

In this study, we estimated the effects of antidepressant amitriptyline (Ami), fluoxetine (Flu), and traditional Chinese medicine Xiaoyaosan (XYS) administration on gut viral composition and function in a chronic unpredictable mild stress (CUMS)-induced depression rat model based on shotgun metagenomic sequencing.

Results

The results showed that treatment with Ami, Flu, and XYS significantly changed the gut viral composition compared with the CUMS-induced rats. At the family level, the abundance of f_unclassified_Caudovirales in CUMS rats was remarkably lower than in the HC rats, nevertheless, XYS significantly recovered the abundance of Caudovirales. Meanwhile, the abundance of Podoviridae was expanded in CUMS rats compared with the HC rats, and the profile was then significantly reduced after XYS treatment. Furthermore, both antidepressants and XYS increased the abundance of Siphoviridae compared with the CUMS rats, but only Ami treatments had significant differences. Subsequent function annotation further implied that Ami, Flu, and XYS showed to involve an alteration of the diverse viral functions, such as carbohydrate metabolism, xenobiotics biodegradation and metabolism, community-prokaryotes, translation, and neurodegenerative disease. Additionally, the co-occurrence network displayed that there are complex interactions between viral operational taxonomic units (vOTUs) represented by temperate phages and the majority of bacterial genera in the intestine ecosystem.

Conclusion

Our study proved for the first time that depression is characterized by massive alterations and functional distortion of the gut viruses, and after oral administration of Ami, Flu, and XYS could affect disordered gut virome, which could be a novel target in depression.

Antidepression of Xingpijieyu formula targets gut microbiota derived from depressive disorder

OBJECTIVE

This investigation aims to determine the antidepressant role of Xingpijieyu formula (XPJYF) mediated via gut microbiota (GM)-brain axis.

METHODS

We collected fecal microbiota from patients with depressive disorder (DD) and cultured microbiota in vitro. Some of microbiota were transplanted into germ-free rats with the intragastric administration of XPJYF grain at the dose of 1.533 g/kg/day. The behaviors were studied by forced swimming test, open field test, sucrose preference test, and body weight. Products of hypothalamus-pituitary-adrenocortical (HPA) axis, neurotransmitter, and serum cytokines were investigated by enzyme linked immunosorbent assay. Glial fibrillary acidic protein (GFAP), a biomarker of astrocyte, was quantified using immunofluorescence. Microbiota culturing in vitro after XPJYF treatment was analyze by 16 s RNA sequencing technology. We used lipopolysaccharide (LPS) to mimic activated rat primary astrocyte in vitro. Brain-derived neurotrophic factor (BDNF), cytokines, and oxidative stress factors were determined by western blotting, and glycometabolism in astrocyte was investigated by 2-deoxy-D-glucose (2-DG) uptake, adenosine triphosphate (ATP), and glucose-1-phosphate (G1P) kits.

RESULTS

Microbiota composition during 8 mg/ml of XPJYF (H12-8) for 12 h showed the more consistency. Lactococcus is enriched in DD-derived microbiota composition, and Biffdobacterium and Lactobacillus in H12-8 group. GLUCOSE1PMETAB-PWY and PWY-7328 of which biofunctions were dominantly encoded by Biffdobacterium were the top two of altered pathways. XPJYF improved behaviors and repressed astrocyte activation in depression rats. XPJYF elevated 2-DG uptake, ATP, glucose-1-phosphate, and brain-derived neurotrophic factor (BDNF), and inhibited cytokines and oxidative stress in LPS-induced astrocyte.

CONCLUSION

XPJYF treatment targets inflammation, activation, and glycometabolim in astrocyte via gut microbiota modulation, thereby improve animal behaviors, HPA axis dysfunction, and neurotransmitter synthesis in depression rats.

Structural Alteration of Gut Microbiota During the Amelioration of Chronic Psychological Stress-Aggravated Diabetes-Associated Cognitive Decline by a Traditional Chinese Herbal Formula, ZiBu PiYin Recipe

BACKGROUND

Chronic psychological stress (PS) hinders the treatment of diabetes-associated cognitive decline (DACD). However, the impact of chronic PS on the risk of developing DACD remains unclear. There is growing evidence that gut flora interventions are promising targets for treating stress-related diseases.

OBJECTIVE

We examined whether chronic PS triggers or exacerbates the onset of DACD in rats and aimed to elucidate whether ZiBuPiYin recipe (ZBPYR) prevents and treats chronic PS-aggravated DACD by dynamically maintaining the components of the gut microbiota.

METHODS

We performed chronic PS (restraint, rotation, and congestion) on ZDF rats to establish a model. Cognitive function was evaluated by behavioral experiments, and activation of the hypothalamic-pituitary-adrenal axis was detected by ELISA. Weekly feces from rats were collected for 16 S RNA sequencing.

RESULTS

We found that chronic PS promoted cognitive abnormalities and exacerbated DACD phenotypes. Additionally, chronic PS altered intestinal flora diversity, dynamically elevating the abundance of Alistipes and Coprococcus; enriching Module 1 (Dorea, Blautia, Ruminococcus) and Module 48 (Blautia); and inhibiting Module 20 (Lactobacillus, SMB53), and Module 42 (Akkermansia). ZBPYR significantly alleviated hyperglycemia and cognitive impairment in chronic PS-aggravated DACD rats and dynamically reduced the abundance of Alistipes and Coprococcus; significantly enriched Module 3 (Ruminococcus) and Module 45 (Lactobacillus, Coprococcus, SMB53); and suppressed Module 2 (Lactobacillus), Module 16 (Turicibacter, Trichococcus, Lactobacillus, 02d06, Clostridium), Module 23 (Bifidobacterium), and Module 43 (Clostridium).

CONCLUSION

ZBPYR might prevent and treat chronic PS-aggravated DACD by dynamically regulating Lactobacillus, Alistipes, and Coprococcus.

Neoagaro-Oligosaccharides Ameliorate Chronic Restraint Stress-Induced Depression by Increasing 5-HT and BDNF in the Brain and Remodeling the Gut Microbiota of Mice

Neoagaro-oligosaccharides (NAOs) belong to the algae oligosaccharides. NAOs have been found to have diverse biological activities. However, the effects of NAOs on depression and their underlying mechanism have not been thoroughly studied. A chronic restraint stress (CRS)-induced C57BL/6J mouse model was used to assess the antidepressant effects of NAOs. Anxiety and depression behaviors were assessed by open field tests (OFT) and forced swimming tests (FST), while interleukin 18 (IL-18), 5-hydroxytryptamine (5-HT) and brain-derived neurotrophic factor (BDNF) were the molecular biomarkers of depression. Fecal microbiota transplantation (FMT) was performed. The results showed that NAO treatment significantly improved the body weight of depressed mice and reduced the central area time in the OFT and immobility time in the FST. NAO treatment decreased the levels of IL-18 in the serum and increased the levels of 5-HT in the serum and whole brain and of BDNF in the whole brain. NAO treatment mitigated the gut microbiota dysbiosis in the depressed mice and reversed the decreased levels of short-chain fatty acids (SCFAs) in the cecum of the depressed mice. FMT indicated that the gut microbiota is, indeed, linked to depression, which was reflected in the changes in weight gain and behaviors. In a word, NAOs effectively reversed the CRS-induced mice model of depression, which depended on the changes in the gut microbiota and SCFAs, as well as its modulation of 5-HT and BDNF.

Overcoming Anxiety Disorder by Probiotic Lactiplantibacillus plantarum LZU-J-TSL6 through Regulating Intestinal Homeostasis

Lactiplantibacillus plantarum LZU-J-TSL6 with high γ-aminobutyric acid (GABA) production (3.838 g/L) was screened and isolated from the Chinese fermented food snack “Jiangshui”. The improvement effect on anxiety disorder was explored using mice as animal models. In vitro results revealed that LZU-J-TSL6 had the potential to colonize the intestine (p < 0.01) and the anxiety-like behavior of the mice after seven days’ gavage with LZU-J-TSL6 was significantly improved (p < 0.01) when compared to the model group. LZU-J-TSL6 was able to effectively increase the GABA content in the mice hippocampus (p < 0.0001) and restore some markers related to anxiety such as brain-derived neurotrophic factor (BDNF), glial fibrillary acidic protein (GFAP), and 5-hydroxytryptamine (5-HT). Simultaneously, it had a certain repair effect on Nissl bodies and colon tissue in mice hippocampus. In addition, LZU-J-TSL6 increased the relative abundance of beneficial bacteria Bacteroides and Muribaculum, thereby regulating the imbalance of intestinal microbiota caused by anxiety disorder. It also affects the nerve pathway and intestinal mucosal barrier by increasing the content of glutamine and γ-aminobutyric acid and other related metabolites, thereby improving anxiety. Therefore, the GABA-producing Lactobacillus plantus LZU-J-TSL6 can be used as a probiotic to exert an indirect or direct anti-anxiety effect by maintaining the balance of the intestinal environment, producing related metabolites that affect nerve pathways and repair the intestinal mucosal barrier. It can be used as an adjuvant treatment to improve anxiety disorders.

Anxiolytic effect of YangshenDingzhi granules: Integrated network pharmacology and hippocampal metabolomics

Anxiety disorder is one of the most common mental diseases. It is mainly characterized by a sudden, recurring but indescribable panic, fear, tension and/or anxiety. Yangshendingzhi granules (YSDZ) are widely used in the treatment of anxiety disorders, but its active ingredients and underlying mechanisms are not yet clear. This study integrates network pharmacology and metabolomics to investigate the potential mechanism of action of YSDZ in a rat model of anxiety. First, potential active ingredients and targets were screened by network pharmacology. Then, predictions were verified by molecular docking, molecular dynamics and western blotting. Metabolomics was used to identify differential metabolites and metabolic pathways. All results were integrated for a comprehensive analysis. Network pharmacology analysis found that Carotene, β-sitosterol, quercetin, Stigmasterol, and kaempferol in YSDZ exert anxiolytic effects mainly by acting on IL1β, GABRA1, PTGS1, ESR1, and TNF targets. Molecular docking results showed that all the affinities were lower than -5 kcal/mol, and the average affinities were -7.7764 kcal/mol. Molecular dynamics simulation results showed that RMSD was lower than 2.5 A, and the overall conformational changes of proteins were small, indicating that the small molecules formed stable complexes with proteins. The results of animal experiments showed that YSDZ exerts anxiolytic effects by regulating GABRA1 and TNF-α, ameliorating pathological damage in hippocampal CA1, and regulating metabolic pathways such as thiamine, cysteine and methionine metabolism, lysine biosynthesis and degradation. Altogether, we reveal multiple mechanisms through which YSDZ exerts its anti-anxiety effects, which may provide a reference for its clinical application and drug development.

Causality of genetically determined metabolites on anxiety disorders: a two-sample Mendelian randomization study

BACKGROUND

Although anxiety disorders are one of the most prevalent mental disorders, their underlying biological mechanisms have not yet been fully elucidated. In recent years, genetically determined metabolites (GDMs) have been used to reveal the biological mechanisms of mental disorders. However, this strategy has not been applied to anxiety disorders. Herein, we explored the causality of GDMs on anxiety disorders through Mendelian randomization study, with the overarching goal of unraveling the biological mechanisms.

METHODS

A two-sample Mendelian randomization (MR) analysis was implemented to assess the causality of GDMs on anxiety disorders. A genome-wide association study (GWAS) of 486 metabolites was used as the exposure, whereas four different GWAS datasets of anxiety disorders were the outcomes. Notably, all datasets were acquired from publicly available databases. A genetic instrumental variable (IV) was used to explore the causality between the metabolite and anxiety disorders for each metabolite. The MR Steiger filtering method was implemented to examine the causality between metabolites and anxiety disorders. The standard inverse variance weighted (IVW) method was first used for the causality analysis, followed by three additional MR methods (the MR-Egger, weighted median, and MR-PRESSO (pleiotropy residual sum and outlier) methods) for sensitivity analyses in MR analysis. MR-Egger intercept, and Cochran's Q statistical analysis were used to evaluate possible heterogeneity and pleiotropy. Bonferroni correction was used to determine the causative association features (P < 1.03 × 10^-4). Furthermore, metabolic pathways analysis was performed using the web-based MetaboAnalyst 5.0 software. All statistical analysis were performed in R software. The STROBE-MR checklist for the reporting of MR studies was used in this study.

RESULTS

In MR analysis, 85 significant causative relationship GDMs were identified. Among them, 11 metabolites were overlapped in the four different datasets of anxiety disorders. Bonferroni correction showing1-linoleoylglycerophosphoethanolamine (OR_{fixed-effect IVW} = 1.04; 95% CI 1.021-1.06; P_{fixed-effect IVW} = 4.3 × 10^-5) was the most reliable causal metabolite. Our results were robust even without a single SNP because of a "leave-one-out" analysis. The MR-Egger intercept test indicated that genetic pleiotropy had no effect on the results (intercept = - 0.0013, SE = 0.0006, P = 0.06). No heterogeneity was detected by Cochran's Q test (MR-Egger. Q = 7.68, P = 0.742; IVW. Q = 12.12, P = 0.436). A directionality test conducted by MR Steiger confirmed our estimation of potential causal direction (P < 0.001). In addition, two significant pathways, the "primary bile acid biosynthesis" pathway (P = 0.008) and the "valine, leucine, and isoleucine biosynthesis" pathway (P = 0.03), were identified through metabolic pathway analysis.

CONCLUSION

This study provides new insights into the causal effects of GDMs on anxiety disorders by integrating genomics and metabolomics. The metabolites that drive anxiety disorders may be suited to serve as biomarkers and also will help to unravel the biological mechanisms of anxiety disorders.

Traditional herbal formula Jiao-tai-wan improves chronic restrain stress-induced depression-like behaviors in mice

OBJECTIVES

Jiao-tai-wan (JTW) has been often used to treat insomnia and diabetes mellitus. Recent studies found its antidepressant activity, but the related mechanism is not clear. This study is to evaluate the therapeutic effects of JTW on chronic restraint stress (CRS)-induced depression mice and explore the potential mechanisms.

METHODS

CRS was used to set up a depression model. Mice in different groups were treated with 0.9 % saline, JTW and fluoxetine. After the last day of CRS, the behavioral tests were conducted. The levels of neurotransmitters, inflammatory cytokines and HPA axis index were detected and the protein expressions of NLRP3 inflammasome complex were determined. H&E, NISSL, TUNEL and immunofluorescence staining were used to observe histopathological changes and the activation of microglia and astrocytes. The potential mechanisms were explored via network pharmacology and verified by Western blot.

RESULTS

The assessment of liver and kidney function showed that JTW was non-toxic. Behavioral tests proved that JTW can effectively ameliorate depression-like symptoms in CRS mice, which may be related to the inhibition of NLRP3 inflammasome activation. JTW can also improve the inflammatory state and HPA axis hyperactivity in mice, and has a protective effect on CRS-induced hippocampal neurons damage. The network pharmacology analysis and the results of Western blot suggested that the antidepressant effects of JTW may be related to the MAPK signaling pathway.

CONCLUSION

Our findings indicated that JTW may exert antidepressant effects in CRS-induced mice by inhibiting NLRP3 inflammasome activation and improving inflammatory state, and MAPK signaling pathway may also be involved.

The Microbiota-Gut-Brain Axis in Depression: The Potential Pathophysiological Mechanisms and Microbiota Combined Antidepression Effect

Depression is a kind of worldwide mental illness with the highest morbidity and disability rate, which is often accompanied by gastrointestinal symptoms. Experiments have demonstrated that the disorder of the intestinal microbial system structure plays a crucial role in depression. The gut–brain axis manifests a potential linkage between the digestion system and the central nervous system (CNS). Nowadays, it has become an emerging trend to treat diseases by targeting intestinal microorganisms (e.g., probiotics) and combining the gut–brain axis mechanism. Combined with the research, we found that the incidence of depression is closely linked to the gut microbiota. Moreover, the transformation of the gut microbiota system structure is considered to have both positive and negative regulatory effects on the development of depression. This article reviewed the mechanism of bidirectional interaction in the gut–brain axis and existing symptom-relieving measures and antidepression treatments related to the gut microbiome.

Correlation between intestinal microbiotal imbalance and 5-HT metabolism, immune inflammation in chronic unpredictable mild stress male rats

To explore the role of intestinal microbiota on the occurrence of depression-like behavior. Twenty male adult Wistar rats were randomly divided into control and experimental groups. Depression-like behavior of the rats was validated using sucrose preference test (SPT) and forced swimming test (FST) after chronic unpredictable mild stress (CUMS) for 3 weeks. Fecal microbiota was analyzed through 16S rRNA sequence analysis. The levels of 5-HT and inflammatory factors in the colon, brain and sera were measured using enzyme-linked immunosorbent assay (ELISA), quantitative PCR (qPCR) and western blotting analyses. The percentage of different types of immune cells in the peripheral blood was determined through flow cytometry. CUMS caused depression-like symptoms, including anhedonia and desperate behavior. Significant differences were found in the structure and abundance of intestinal microbiota. CUMS intervention significantly increased the levels of 5-HT and Tph1 in the colon and decreased the level of Scl6a4. The concentrations of 5-HT and Tph2 in the prefrontal and hippocampal tissues were lower, while IDO1 was higher. Certain cytokines, such as IL-6, IL-1 and TNF-ɑ, were significantly elevated in peripheral blood, while the percentage of CD3⁺ CD4⁺ double-positive cells and CD4⁺ /CD8⁺ ratio were downregulated in the CUMS group. Pearson correlation analysis showed that intestinal microbiota was significantly associated with not only the metabolism of 5-HT in intestinal and brain tissues, but also with the proportion of immune cells and certain cytokines. Stress can lead to disturbances in the intestinal microbial structure, which may contribute to depression by interfering with 5-HT metabolism and immune inflammatory responses.

Gut Microbiome and Metabolome Changes in Mice With Acute Vestibular Deficit

Vestibular deficit is a very common disorder in clinical practice and is characterized by vertigo, spontaneous nystagmus, and autonomic nervous symptoms, including nausea, vomiting, and sweating. In addition, the comorbidity of vestibular deficit and anxiety has long been an integral component of the medical literature. Previous studies have suggested that the mechanisms underlying this comorbidity involved overlap of vestibular and cerebellar networks. Emerging evidence has shown that the microbiota–gut–brain axis plays a key role in the regulation of affective disorders. Thus, we hypothesized that the gut microbiota may be involved in the comorbidity of vestibular deficit and anxiety. To verify this, we constructed a unilateral labyrinthectomy mouse model to simulate vestibular deficit. Then, 16S rRNA gene sequencing and liquid chromatography–mass spectrometry (LC-MS) were used to analyze the microbiome and metabolome of the cecal samples collected from mice in the unilateral labyrinthectomy, sham surgery, and control groups. Notably, unilateral labyrinthectomy shaped the composition of the mouse gut microbiome, resulting in increased abundance of Lachnospiraceae NK4A136 group, Odoribacter and Roseburia and decreased abundance of Prevotella and Parasutterella at the genus level. Tax4Fun functional prediction indicated a decrease in tryptophan metabolism in mice in the unilateral labyrinthectomy group. Moreover, functional correlation of changes in gut microbes and metabolites between different groups showed that the oleamide level was negatively correlated with Odoribacter abundance (r = -0.89, p = 0.0002). The butyric acid level was positively correlated with Parasutterella abundance (r = 0.85, p = 0.0010). The propanoate level was negatively correlated with Prevotella abundance (r = -0.81, p = 0.0020). The 20-HETE level was positively correlated with Parasutterella abundance (r = 0.84, p = 0.0013). The altered microbes and metabolites were closely related to the pathogenesis of affective disorders. Our results not only offer novel insights into the vestibular deficit comorbid with anxiety but also build an important basis for future research on this etiology.

Sex Difference of Effect of Sophora flavescens on Gut Microbiota in Rats

Objective

By observing the sex difference of the gut microbiota in rats and the influence of Sophora flavescens (S. flavescens) on the gut microbiota in rats of different genders, it is hoped that it can provide reference materials for the rational use of S. flavescens in clinical practice.

Method

Taking samples of the jejunum (containing intestinal contents) and feces of 8-week-old rats, and detecting the composition of gut microbiota of females and males by 16S rRNA sequencing technology; At the same time, 8-week-old rats were gavaged with different doses of S. flavescens decoction, and the duodenum, jejunum, ileum, and colon (including the intestinal contents) samples were collected at 1, 2, and 3 weeks, using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) technology and real-time fluorescent quantitative PCR (qRT-PCR) technology to observe the changes in the structure and the quantitative changes of 4 major intestinal dominant bacteria Enterococcus, Bacteriodes, Lactobacillus, and Clostridium in each intestinal segment, respectively.

Result

(1) The gut microbiota of normal rats without administration also had obvious gender differences; (2) S. flavescens significantly affects the composition of gut microbiota, and in different intestinal segments, this effect was different between genders under different dosages and different continuous administration times.

Conclusion

The effect of S. flavescens on the gut microbiota of rats had gender differences.

Natural products for the treatment of stress-induced depression: Pharmacology, mechanism and traditional use

ETHNOPHARMACOLOGICAL RELEVANCE

Depression, one of the most common psychiatric disorders, is the fourth leading cause of long-term disability worldwide. A series of causes triggered depression, including psychological stress and conflict, as well as biological derangement, among which stress has a pivotal role in the development of depression. Traditional herbal medicine has been used for the treatment of various disorders including depression for a long history with multi-targets, multi-levels and multi-ways, attracting great attention from scholars. Recently, natural products have been commercialized as antidepressants which have become increasingly popular in the world health drug markets. Major research contributions in ethnopharmacology have generated and updated vast amount of data associated with natural products in antidepressant-like activity.

AIMS OF THE REVIEW

This review aims to briefly discuss the pathological mechanism, animal models of stress-induced depression, traditional use of herbal medicines and especially recapitulate the natural products with antidepressant activity and their pharmacological functions and mechanism of action, which may contribute to a better understanding of potential therapeutic effects of natural products and the development of promising drugs with high efficacy and low toxicity for the treatment of stress-induced depression.

MATERIALS AND METHODS

The contents of this review were sourced from electronic databases including PubMed, Sci Finder, Web of Science, Science Direct, Elsevier, Google Scholar, Chinese Knowledge On frastructure (CNKI), Wan Fang, Chinese Scientific and Technological Periodical Database (VIP) and Chinese Biomedical Database (CBM). Additional information was collected from Yao Zhi website (https://db.yaozh.com/). Data were obtained from April 1992 to June 2021. Only English language was applied to the search. The search terms were 'stress-induced depression', 'pathological mechanism' in the title and 'stress', 'depression', 'animal model' and 'natural products' in the whole text.

RESULTS

Stress-induced depression is related to the monoaminergic system, hypothalamic-pituitary-adrenal (HPA) axis, neuronal plasticity and a series of inflammatory factors. Four main types of animal models of stress-induced depression were represented. Fifty-eight bioactive phytochemical compounds, fifty-six herb medicines and five formulas from traditional Chinese medicine were highlighted, which exert antidepressant effects by inhibiting monoamine oxidase (MAO) reaction, alleviating dysfunction of the HPA axis and nerve injury, and possessing anti-inflammatory activities.

CONCLUSIONS

Natural products provide a large number of compounds with antidepressant-like effects, and their therapeutic impacts has been highlighted for a long time. This review summarized the pathological mechanism and animal models of stress-induced depression, and the natural products with antidepressant activity in particular, which will shed light on the action mechanism and clinical potential of these compounds. Natural products also have been a vital and promising source for future antidepressant drug discovery.

Gut microbiota and Autism Spectrum Disorder: From pathogenesis to potential therapeutic perspectives

Autism is a complex neurodevelopmental disorder which disrupts communication, social and interactive skills followed by appearance of repetitive behavior. The underlying etiology remains incomprehensible but genetic and environmental factors play a key role. Accumulated evidence shows that alteration in level of gut microbes and their metabolites are not only linked to gastrointestinal problems but also to autism. So far the mix of microbes that is present in the gut affects human health in numerous ways through extensive bacterial-mammalian cometabolism and has a marked influence over health via gut-brain-microbial interactions. Healthy microbiota may even ease the symptoms of autism, as microbial balance influences brain development through the neuroendocrine, neuroimmune, and autonomic nervous systems. In this article, we focused on reviewing the correlation between gut microbiota and their metabolites on symptoms of autism by utilizing prebiotics, probiotics and herbal remedies to target gut microflora hence autism.

Nutraceuticals and Physical Activity as Antidepressants: The Central Role of the Gut Microbiota

Major depressive disorder (MDD) is a common mental illness. Evidence suggests that the gut microbiota play an essential role in regulating brain functions and the pathogenesis of neuropsychiatric diseases, including MDD. There are numerous mechanisms through which the gut microbiota and brain can exchange information in a continuous, bidirectional communication. Current research emphasizes the interexchange of signals influenced by the gut microbiota that are detected and transduced in information from the gut to the nervous system involving neural, endocrine, and inflammatory mechanisms, suggesting a relationship between oxidative stress and the pathophysiology of MDD via the hyperactivation of inflammatory responses. Potential sources of inflammation in the plasma and hippocampus of depressed individuals could stem from increases in intestinal permeability. Some nutraceuticals, such as specific probiotics, namely psychobiotics, polyphenols, carotenoids, butyrate, and prebiotics, have been demonstrated to exert an antidepressant activity, but most of them need to be metabolized and activated by gut microorganisms. By inducing changes in the gut microbiota composition, physical exercise might also exert a role in alleviating depression-like symptoms. The mutual relationships among nutraceuticals, exercise, and depression will be discussed, and the potential role of the gut microbiota as a therapeutic target to treat depression will be explored.

Lactiplantibacillus plantarum DMDL 9010 alleviates dextran sodium sulfate (DSS)-induced colitis and behavioral disorders by facilitating microbiota-gut-brain axis balance

Previous studies have found that probiotic supplements can ameliorate mental behavioral disorders. This study investigated the effects of Lactiplantibacillus plantarum DMDL 9010 (LP9010) intake on the depression-like behavior induced by dextran sodium sulfate (DSS) and its possible mechanism. Male C57BL/6N mice were fed with DSS to establish the model of ulcerative colitis. LP9010 intake reduced the DSS-induced inflammatory response, and repaired intestinal barrier damage, as well as lightened depression-like behavior. LP9010 supplementation also inhibited neuroinflammation by up-regulating the levels of neurotransmitters, especially 5-HT, NE, DA, and 5-HIAA. Moreover, the intake of LP9010 reorganized the gut microbiome by increasing the relative abundance of Bacteroidetes and Firmicutes, and decreasing the relative abundance of Proteobacteria and Verrucomicrobia. Furthermore, treatment with LP9010 increased the levels of short-chain fatty acids, such as butyric acid and propionic acid. In conclusion, LP9010 intake was a promising probiotic intervention strategy for the prevention of colitis-induced behavioral disorders through the microbiota-gut-brain axis.

Advancement of Traditional Chinese Medicine in Regulation of Intestinal Flora: Mechanism-based Role in Disease Management

Intestinal microecology is the largest and most complex human microecology. The intestinal microflora plays an important role in human health. Imbalance of intestinal microflora contributes to the occurrence and development of many diseases. Recently, the treatment of human diseases by regulating intestinal microflora has become a research topic of interest. Traditional Chinese medicine considers the whole human body as the central concept in disease treatment strategies. It advocates maintaining the coordination and balance of the functions of various organs and systems of the human body, including the intestinal microflora. Traditional Chinese medicine improves the metabolism and immune function of the human body by regulating the intestinal microflora. The intestinal microflora could trigger pharmacological activity or reduce toxicity of drugs through regulating metabolism, which enables traditional Chinese medicine formulations to exert their best therapeutic effects. This review summarized the relationship between the intestinal microflora and digestive system, tumors, and other diseases. Furthermore, the role of traditional Chinese medicine in the treatment of tumors, and other diseases is discussed. The relationship among traditional Chinese medicine and the common intestinal microflora, pathogenesis of human diseases, and effective intervention methods were elaborated. In addition, we explored the research progress of traditional Chinese medicine in the treatment of various human diseases by regulating intestinal microflora to provide new treatment concepts. There is a close relationship between traditional Chinese medicine and the intestinal microflora. Traditional Chinese medicine formulations contribute to maintain the natural balance of the intestinal tract and the intestinal microflora to achieve treatment effects. This paper summarizes the mechanism of action of traditional Chinese medicine formulations in regulating the intestinal microflora in the prevention and treatment of various diseases. Furthermore, it summarizes information on the application of the interaction between traditional Chinese medicine preparations and the regulation of intestinal microflora in the treatment of common human diseases. Intestinal microflora plays a key role in traditional Chinese medicine in maintaining the natural balance of physiology and metabolism of human body. It will provide a theoretical basis for the traditional Chinese medicine preparations in the prevention and treatment of common human diseases, and simulate future research on this aspect.

Jasmine Tea Attenuates Chronic Unpredictable Mild Stress-Induced Depressive-like Behavior in Rats via the Gut-Brain Axis

The number of depressed people has increased worldwide. Dysfunction of the gut microbiota has been closely related to depression. The mechanism by which jasmine tea ameliorates depression via the brain-gut-microbiome (BGM) axis remains unclear. Here, the effects of jasmine tea on rats with depressive-like symptoms via the gut microbiome were investigated. We first established a chronic unpredictable mild stress (CUMS) rat model to induce depressive symptoms and measured the changes in depression-related indicators. Simultaneously, the changes in gut microbiota were investigated by 16S rRNA sequencing. Jasmine tea treatment improved depressive-like behaviors and neurotransmitters in CUMS rats. Jasmine tea increased the gut microbiota diversity and richness of depressed rats induced by CUMS. Spearman’s analysis showed correlations between the differential microbiota (Patescibacteria, Firmicutes, Bacteroidetes, Spirochaetes, Elusimicrobia, and Proteobacteria) and depressive-related indicators (BDNF, GLP-1, and 5-HT in the hippocampus and cerebral cortex). Combined with the correlation analysis of gut microbiota, the result indicated that jasmine tea could attenuate depression in rats via the brain- gut-microbiome axis.

Danzhi Xiaoyao Powder Promotes Neuronal Regeneration by Downregulating Notch Signaling Pathway in the Treatment of Generalized Anxiety Disorder

Background: Generalized anxiety disorder (GAD) is one of the most common types of anxiety disorders with unclear pathogenesis. Our team's previous research found that extensive neuronal apoptosis and neuronal regeneration disorders occur in the hippocampus of GAD rats. Danzhi Xiaoyao (DZXYS) Powder can improve the anxiety behavior of rats, but its molecular mechanism is not well understood. Objective: This paper discusses whether the pathogenesis of GAD is related to the abnormal expression of Notch signal pathway, and whether the anti-anxiety effect of DZXYS promotes nerve regeneration in the hippocampus by regulating the Notch signaling pathway. Methods: The animal model of GAD was developed by the chronic restraint stress and uncertain empty bottle stimulation method. After the model was successfully established, the rats in the model preparation group were divided into the buspirone, DZXYS, DZXYS + DAPT, and model groups, and were administered the corresponding drug intervention. The changes in body weight and food intake of rats were continuously monitored throughout the process. The changes in anxiety behavior of rats were measured by open field experiment and elevated plus-maze test, and morphological changes and regeneration of neurons in the rat hippocampus were observed by HE staining and double immunofluorescence staining. Changes in the expression of key targets of the Notch signaling pathway in the hippocampus were monitored by real-time fluorescence quantitative PCR and western blotting. Results: In this study, we verified that the GAD model was stable and reliable, and found that the key targets of the Notch signaling pathway (Notch1, Hes1, Hes5, etc.) in the hippocampus of GAD rats were significantly upregulated, leading to the increased proliferation of neural stem cells in the hippocampus and increased differentiation into astrocytes, resulting in neuronal regeneration. DZXYS intervention in GAD rats can improve appetite, promote weight growth, and significantly reverse the anxiety behavior of GAD rats, which can inhibit the upregulation of key targets of the Notch signaling pathway, promote the differentiation of neural stem cells in the hippocampus into neurons, and inhibit their differentiation into astrocytes, thus alleviating anxiety behavior. Conclusion: The occurrence of GAD is closely related to the upregulation of the Notch signaling pathway, which hinders the regeneration of normal neurons in the hippocampus, while DZXYS can downregulate the Notch signaling pathway and promote neuronal regeneration in the hippocampus, thereby relieving anxiety behavior.

Formononetin reshapes the gut microbiota, prevents progression of obesity and improves host metabolism

Formononetin (FMNT) is an isoflavone that has been studied for its anti-hyperglycemic and anti-diabetic effects. However, the effect of FMNT on gut dysbiosis and metabolic complications associated with western-style diet consumption has not been reported yet. This study aimed to investigate how FMNT can reshape the gut microbiota at a specific dosage and ameliorate the symptoms of obesity-related metabolic disorders in both genders. Results indicate that FMNT at 60 mg per kg bodyweight dosage can effectively control body weight, hyperglycemia, and insulin resistance, leptin levels and improve HDL to LDL ratio. FMNT treatment suppressed Porphyromonadaceae (Uncultured Alistipes) and augmented maximum genera from families Lachnospiraceae and Clostridiacea, but at species level, formononetin increased Clostridium aldenense, Clostridiaceae unclassified, Eubacterium plexicaum; acetate and butyrate-producing bacteria. Moreover, formononetin regulated the expression of specific liver miRNA involved in obesity and down-regulated mRNA expression levels of pro-inflammatory cytokines IL-6, IL-22 and TNF-α. Additionally, FMNT maintained intestinal membrane integrity by regulating the expression of Muc-2 and occludin. Our findings indicate that FMNT could be a potential prebiotic that can effectively regulate the gut microbiota, improve host metabolism and systemic inflammation, and prevent deleterious effects of a western-style diet by elevating acetate lactate and lactate butyrate producers.

Semen Sojae Praeparatum alters depression-like behaviors in chronic unpredictable mild stress rats via intestinal microbiota

A large number of Chinese medical books present that Semen Sojae Praeparatum, a fermented food, possesses antidepressant effect, but the mechanism of this antidepressant effect remains largely unknown. This study aimed to explore the effect of Semen Sojae Praeparatum on rats with chronic unpredictable mild stress (CUMS)-induced depression. The results showed that Semen Sojae Praeparatum improved depression-like behaviors (negative preference of sugar water and increased swimming immobility time and time spent in the dark zone) and effectively reduced cell morphological changes in the dentate gyrus of the hippocampus in CUMS rats. In addition, Semen Sojae Praeparatum significantly promoted the contents of norepinephrine (NE), 5-hydroxytryptamine (5-HT), brain-derived neurotrophic factor (BDNF), and gamma-aminobutyric acid (GABA) in the hippocampus and the content of BDNF in the serum (p < 0.05). 16S rRNA sequencing analysis results showed that Semen Sojae Praeparatum increased the abundance of genus Ruminococcaceae_UCG-008 and decreased those of genera Lactobacillus and Bacteroides. Genus Ruminococcaceae_UCG-008 was positively correlated with GABA and BDNF levels in the hippocampus; genus Lactobacillus had a positive correlation with 5-HT; and genus Bacteroides had negative correlations with 5-HT, BDNF, and NE. In addition, Semen Sojae Praeparatum considerably decreased the concentration of short-chain fatty acids (SCFAs). These results indicated that Semen Sojae Praeparatum fermented by Rhizopus chinensis 12 and Bacillus sp. DU-106 alleviated the neurotransmitter levels and structural changes in the neuronal morphology of the hippocampus associated with the modulation of gut microbiota and SCFAs. Therefore, this study confirmed that Semen Sojae Praeparatum could alter depression and provide a theoretical basis for the investigation of the relationship between the microbiota-gut-brain axis and antidepressant.

The role of the intestinal microbiota in the pathogenesis of host depression and mechanism of TPs relieving depression

Depression is a prevalent neuropsychiatric disease with a high recurrence rate, affecting over 350 million people worldwide. Intestinal flora disorders and gut-brain-axis (GBA) dysfunction may cause mental disorders. Alterations in the intestinal flora composition could increase the permeability of the gut barrier, activate systemic inflammation and immune responses, regulate the release and efficacy of monoamine neurotransmitters, alter the activity and function of the hypothalamic-pituitary-adrenal (HPA) axis, and modify the abundance of the brain-derived neurotrophic factor (BDNF); all of these showed a close correlation with the occurrence of depression. In addition, the disturbance of the intestinal flora is related to circadian rhythm disorders, which aggravate the symptoms of depression. Tea polyphenols (TPs) have been found to have antidepressant effects. Therefore, the close reciprocity between the intestinal flora and circadian rhythm provides a new opportunity for TPs to regulate depression relying on the intestinal flora. In this review, we discussed the relationship between intestinal flora dysbiosis and the pathogenesis of depression and the mechanism of TPs relieving depression via the GBA.

Association Between Gastrointestinal Symptoms and Depression in a Representative Sample of Adults in the United States: Findings From National Health and Nutrition Examination Survey (2005-2016)

BACKGROUND

The microbiome's role in the etiology of depression has been a topic of many recent investigations. Findings suggest that dysbiosis, which describes a general disturbance in the gut microbiome, underlies negative gastrointestinal symptoms and is implicated in depression. We studied associations between gastrointestinal symptoms and depressive symptoms at a population level using cross-sectional data from the National Health and Nutrition Examination Survey (2005-2016, n = 36,287). We hypothesized that the odds of depressive symptoms would be significantly higher in those showing signs of gastrointestinal distress.

METHODS

We analyzed 31,191 adults participating in the National Health and Nutrition Examination Survey from 2005-2016. Outcomes included presence of mucus or liquid in bowel leakage and stomach illness in the past month, diarrhea in the past year, and number of weekly bowel movements. The survey (and thus, our analyses) does not include microbiome samples, only self-reported gastrointestinal symptoms. Depressive symptoms were measured using the Patient Health Questionnaire. Moderate, moderately severe, and severe scores were coded as a positive outcome.

RESULTS

Compared to those without depressive symptoms, those with moderate-to-severe depressive symptoms had elevated odds of bowel mucus (odds ratio = 2.78; 95% confidence interval = 1.82-4.24), bowel liquid (odds ratio = 2.16; 95% confidence interval = 1.63-2.86), stomach illness (odds ratio = 1.82; 95% confidence interval = 1.31-2.53), diarrhea (sometimes vs. never odds ratio = 1.72; 95% confidence interval = 1.30-2.29), and constipation (sometimes vs. never odds ratio = 2.76; 95% confidence interval = 2.11-3.62). Overall, those with gastrointestinal symptoms were significantly more likely to have depressive symptoms.

CONCLUSIONS

While the intricacies of the brain-gut axis are being investigated at the molecular level, these population data provide further evidence for the association between depressive symptoms and signs of dysbiosis, which may inform health care providers' patient interactions.

Antidepressant effect of electroacupuncture on modulating the expression of c-Fos/AP-1 through the JNK signaling pathway

The effectiveness and safety of electroacupuncture (EA) for depression have been identified by abundant clinical trials and experimental findings. The c-Jun-NH(2)-terminal kinase (JNK) signaling pathway is considered to be involved in the antidepressant mechanism of EA. However, the antidepressant effect of EA via modulating the expression of c-Fos/activator protein-1 (AP-1) under the condition of JNK inhibition remains unexplored. In this study, we investigated the antidepressant effect and possible mechanism of EA in regulating the expression of c-Fos/AP-1 under the condition of JNK inhibition by SP600125 in rats exposed to chronic unpredictable mild stress (CUMS). The depression-like behaviors were evaluated by the body weight, sucrose preference test (SPT), and open field test (OFT). The expression levels of c-Jun in the hypothalamus, c-Fos in the pituitary gland, and c-Fos and AP-1 in the serum of CUMS induced rat model of depression were detected by ELISA. The results indicated that treatment with EA and fluoxetine can reverse the CUMS-induced depression-like behaviors in rats and can up-regulate the expression levels of c-Jun in the hypothalamus, c-Fos in the pituitary gland, and c-Fos and AP-1 in the serum. Of note, the data demonstrated that SP600125, the inhibitor of JNK signaling pathway, can exert synergistic effect with EA in regulating CUMS-induced abnormal activation of the JNK signaling pathway. The antidepressant effect of EA might be mediated by modulating the expression of c-Fos/AP-1.

Supplementation with soy isoflavones alleviates depression-like behaviour via reshaping the gut microbiota structure

Soy isoflavones (SI) are known for their beneficial effects in alleviating neurodegenerative diseases, while the mechanism of alleviation of depression-like behaviour by SI remains unclear. In this study, a chronic unpredictable mild stress (CUMS)-induced depression rat model was used to determine the effect of SI in alleviating depression-like behaviour and its possible mechanisms. SI supplements significantly improved the CUMS-induced depression-like behaviour by increasing the monoamine neurotransmitter levels. A specific SI dose significantly modulated the composition of the gut microbiota, which in turn improved the maximum biotransformation ability of SI. Spearman's correlation analysis illustrated that some of the gut microbiota genera were strongly correlated with monoamine neurotransmitters. Moreover, more attention should be paid to gender differences, which may be related to changes in the gut microbiota. These results suggest that SI might affect monoamine neurotransmitters of CUMS rats by reshaping the structure of the gut microbiota, thereby alleviating depression-like behaviour.

Beneficial Effect of Alkaloids From Sophora alopecuroides L. on CUMS-Induced Depression Model Mice via Modulating Gut Microbiota

It was recently shown that the gut microbiota of both depression patients and depression model animals is significantly altered, suggesting that gut microbes are closely related to depression. Here, we investigated the effects of Sophora alopecuroides L.-derived alkaloids on the gut microbiota of mice with depression-like behaviors. We first established a mouse model of depression via chronic unpredictable mild stress (CUMS) and detected changes in depression-like behaviors and depression-related indicators. Simultaneously, 16S rRNA sequencing was performed to investigate gut microbiota changes. Sophora alopecuroides L.-derived alkaloids improved depression-like behaviors and depression-related indicators in mice. The alkaloids decreased the gut microbiota diversity of CUMS mice and depleted intestinal differentially abundant "harmful" microbiota genera. Spearman analysis showed that there is a certain correlation between the differential microbiota (Lactobacillus, Helicobacter, Oscillospira, Odoribacter, Mucispirillum, Ruminococcus), depression-like behaviors, and depression-related indicators. Combined with the predictive analysis of gut microbiota function, these results indicate that alkaloids improve depression in mice through modulating gut microbiota.

The antidepressant-like effects of the water extract of Panax ginseng and Polygala tenuifolia are mediated via the BDNF-TrkB signaling pathway and neurogenesis in the hippocampus

ETHNOPHARMACOLOGY RELEVANCE

The water extract of Panax ginseng (GT) and Polygala tenuifolia (YT), the main constituents of the commonly used kai-xin-san formula of traditional Chinese medicine, represents SY. It possesses strong neuroprotective effects. Using behavioural tests, we have previously established that the SY formulation exerts superior antidepressant activity than that of GT or YT.

AIM

To elucidate the impact of SY treatment on chronic unpredictable mild stress (CUMS)-induced depressive-like behaviours and the prospective mechanism related to hippocampal neurogenesis and the BDNF signaling pathway.

METHODS

We exposed Sprague-Dawley rats (male; 180-200 g) to CUMS for 35 days. The rats in the experimental treatment groups were daily treated with either fluoxetine (10 mg kg-1d-1) or SY (67.5, 135, or 270 mg kg-1d-1) orally until the behavioural tests (tail suspension test [TST], novelty-suppressed feeding test [NSFT], sucrose preference test [SPT], and forced swim test [FST]) were completed. We assessed the modifications in the hippocampal neurogenesis and the BDNF signaling pathway post-treatment with CUMS and SY. Additionally, K252a, a tyrosine protein kinase inhibitor, was utilized to evaluate the antidepressant mechanisms of SY.

RESULT

s: The results of SPT, NSFT, FST, and TST in CUMS-exposed rats confirmed the antidepressant actions of SY. Additionally, SY treatment induced the BDNF signaling pathway and reversed the hippocampal neurogenesis caused by CUMS. Moreover, we found that the TrkB antagonist K252a blocked SY effects on behavioural improvement, inhibited the incremental effects of SY on hippocampal neurogenesis, and eliminated the impact of SY on BDNF-TrkB signaling activation. Thus, the impact of SY treatment on BDNF signaling molecules (pAkt, pERK1/2, and pCREB) were significantly inhibited by K252a.

CONCLUSIONS

This study showed that SY acted as an antidepressant in rats exhibiting CUMS-induced depressive-like behaviours, and was facilitated by promoting hippocampal neurogenesis and the BDNF signaling pathway activation. Thus, SY could act as a potential novel supplement or adjuvant to prevent or treat clinical depressive disorders.

Features of the gut microbiota in ulcerative colitis patients with depression: A pilot study

Despite the establishment of the links between ulcerative colitis (UC) and depression, between UC and gut microbiota, few correlations between depression and gut microbiota have yet been demonstrated especially in ulcerative colitis patients. The objective of our study was therefore to determine whether the comorbidity of depressive disorder in ulcerative colitis patients correlate with alterations in the gut microbiota and to identify the specific microbiota signatures associated with depression.Between March 2017 and February 2018, 31 healthy volunteers, 31 UC patients without depression, and 31 UC patients with depression from Longhua Hospital were enrolled. Clinical data and fecal samples were collected for each patient. Fecal bacteria were identified using 16 s rRNA sequencing. We compared microbial composition among the 3 groups using bioinformatic analysis.Patients with UC with depression had higher disease severity (P < .05). The UC without depression group had moderate reduction of microbial abundance and uniformity compared to the control group. The UC with depression group had the lowest microbial abundance. With regard to the vital bacteria in the microbiota-gut-brain axis, patients with UC and depression had the lowest abundance of Firmicutes, Clostridia, and Clostridiales but the highest abundance of Proteobacteria, Gammaproteobacteria, and Bacilli.The presence of depression in UC patients presented significant differences in the composition of gut microbiota compared with UC patients without depression, with increased abundance of Firmicutes and reduced abundance of Proteobacteria.

Geniposide Alleviates Oxidative Stress of Mice With Depression-Like Behaviors by Upregulating Six3os1

Depression is a major cause of disease burden and severely impairs well-being of patients around the globe. Geniposide (GP) has been revealed to play a significant role in depression treatment. Of note, RNA sequencing of this study identified highly expressed long non-coding RNA Six3os1 in response to GP treatment. Thus, we aim to explore how GP affected chronic unpredictable mild stress (CUMS)-induced depression-like behaviors in mice in vivo and in vitro and the downstream molecular mechanism related to Six3os1. The relationship of Six3os1, miR-511-3p and Fezf1 was evaluated by dual-luciferase reporter gene assay, RIP assay, and RNA pulling down assay. Ectopic expression and knockdown experiments were developed in CUMS-induced mice and neurons with or without GP treatment. In vitro experiments and behavioral tests were conducted to examine alteration of CUMS-triggered oxidative stress following different interferences. The experimental data validated that GP treatment resulted in high expression of Six3os1 and Fezf1 and poor expression of miR-511-3p in CUMS-induced neurons. Six3os1 activated the AKT signaling pathway by upregulating miR-511-3p-targeted Fezf1. Either GP treatment or overexpression of Six3os1 or Fezf1 alleviated depression-like behaviors of CUMS-induced mice. GP treatment, miR-511-3p inhibition or overexpression of Six3os1 or Fezf1 not only reduced oxidative stress in CUMS-induced mice and neurons, but also reduced CUMS-induced neuronal apoptosis. Collectively, GP treatment-mediated Six3os1 upregulation ameliorated oxidative stress of mice with depression-like behaviors via the miR-511-3p/Fezf1/AKT axis.

Crocin-I alleviates the depression-like behaviors probably via modulating "microbiota-gut-brain" axis in mice exposed to chronic restraint stress

BACKGROUND

Depressive disorder is rapidly advancing in the worldwide, and therapeutic strategy through "gut-brain" axis has been proved to be effective. Crocin, has been found to have antidepressant activity. However, there is no thorough research for the effects of crocin-I (a major active component of crocin) on depression and its underlying mechanism.

METHODS

We investigated the antidepressant effect of six-week oral administration of crocin-I in a mice model of depression induced by four-week CRS. Based on the "microbiota-gut-brain" axis, we determined the effects of crocin-I administration on gut microbiota, intestinal barrier function, short chain fatty acids and neurochemical indicators.

RESULTS

Administration of crocin-I at a dose of 40 mg/kg for six weeks mitigated depression-like behaviors of depressed mice as evidenced by behaviors tests. In addition, crocin-I reduced the levels of lipopolysaccharide (LPS), Interleukin-6and tumor necrosis factor-α (TNF-α) in serum and TNF-α expression in the hippocampus, and increased the hippocampal brain-derived neurotrophic factor. Besides, 16 s rRNA sequencing revealed that crocin-I mitigated the gut microbiota dysbiosis in depressed mice as represented by the decreased abundance of Proteobacteria and Bacteroidetes, Sutterella spp. and Ruminococcus spp. and increased abundances of Firmicutes, Lactobacillus spp. and Bacteroides spp. Moreover, gas chromatography-mass spectrometry revealed that crocin-I reversed the decreased levels of short-chain fatty acids (SCFAs) in feces of depressed mice. Furthermore, crocin-I improved the impaired intestinal barrier by increasing expression of Occludin and Claudin-1, which contributed to the decreased LPS leakage.

LIMITATIONS

Only the male mice were used; the dose-effect relationship should be observed.

CONCLUSION

These results suggested that crocin-I effectively alleviated depression-like behavior, likely depended on the gut microbiota and its modulation of intestinal barrier and SCFAs.

Impact of a Model Used to Simulate Chronic Socio-Environmental Stressors Encountered during Spaceflight on Murine Intestinal Microbiota

During deep-space travels, crewmembers face various physical and psychosocial stressors that could alter gut microbiota composition. Since it is well known that intestinal dysbiosis is involved in the onset or exacerbation of several disorders, the aim of this study was to evaluate changes in intestinal microbiota in a murine model used to mimic chronic psychosocial stressors encountered during a long-term space mission. We demonstrate that 3 weeks of exposure to this model (called CUMS for Chronic Unpredictable Mild Stress) induce significant change in intracaecal β-diversity characterized by an important increase of the Firmicutes/Bacteroidetes ratio. These alterations are associated with a decrease of Porphyromonadaceae, particularly of the genus Barnesiella, a major member of gut microbiota in mice and humans where it is described as having protective properties. These results raise the question of the impact of stress-induced decrease of beneficial taxa, support recent data deduced from in-flight experimentations and other ground-based models, and emphasize the critical need for further studies exploring the impact of spaceflight on intestinal microbiota in order to propose strategies to countermeasure spaceflight-associated dysbiosis and its consequences on health.

Role of gut microbiota in identification of novel TCM-derived active metabolites

Traditional Chinese Medicine (TCM) has been extensively used to ameliorate diseases in Asia for over thousands of years. However, owing to a lack of formal scientific validation, the absence of information regarding the mechanisms underlying TCMs restricts their application. After oral administration, TCM herbal ingredients frequently are not directly absorbed by the host, but rather enter the intestine to be transformed by gut microbiota. The gut microbiota is a microbial community living in animal intestines, and functions to maintain host homeostasis and health. Increasing evidences indicate that TCM herbs closely affect gut microbiota composition, which is associated with the conversion of herbal components into active metabolites. These may significantly affect the therapeutic activity of TCMs. Microbiota analyses, in conjunction with modern multiomics platforms, can together identify novel functional metabolites and form the basis of future TCM research.