Chaihu-shugan-san alleviates depression-like behavior in mice exposed to chronic unpredictable stress by altering the gut microbiota and levels of the bile acids hyocholic acid and 7-ketoDCA

Identification of antidepressant constituents from Xiangfu-chuanxiong herbal medicine pair via spectrum-effect relationship analyses, molecular docking and corticosterone-induced PC12 cells

Herbal medicine pair, composed of two single herbs, is a relatively fixed minimum prescription unit in the traditional Chinese medicine's formula and has special significance in clinic. The combination of Xiangfu (the rhizoma of Cyperus rotundus L, XF) and Chuanxiong (the rhizoma of Ligusticum chuanxiong Hort, CX) has been recoded as an herbal medicine pair XF-CX in the Yuan Dynasty (1347 CE) of China and widely used in traditional Chinese medicine formula, including Chaihu Shugan San, which has been clinically used for treatment of depression. However, the optimal ratio of the XF-CX herbal medicine pair and its antidepressant constituents are still unclear. Herein, the antidepressive-like effects of XF-CX herbal medicine pairs with different ratios of XF and CX (2:1, 1:1, 1:2) were evaluated using behavioral despair animal models in mice, and then its potential antidepressant constituents were recognized by spectrum-effect relationship analyses. Finally, the potential antidepressant constituents of the XF-CX herbal medicine pair were validated by molecular docking with glucocorticoid receptor and corticosterone (CORT)-induced PC12 cell injury model. The results indicated that different ratios of XF-CX pairs had antidepressive-like effects, and the XF-CX (2:1) exhibited a more significant effect. Thirty-two potential antidepressant constituents in the XF-CX herbal medicine pair were screened out from the spectrum-effect relationship combined molecular docking analyses. Among them, senkyunolide A, cyperotundone, Z-ligustilide, and levistilide A were validated to have protective effects against CORT-induced injury in PC12 cells. Our findings not only obtained the optimal ratio of XF-CX in the herbal medicine pair for the treatment of depression but also its potential antidepressant constituents, which will benefit in elucidating the mechanism of action and promoting the application of the herbal medicine pair in the clinic.

Effectiveness and safety of Chaihu-Shugan-San for treating depression based on clinical cases: An updated systematic review and meta-analysis

BACKGROUND

Chaihu-Shugan-San (CSS), a Traditional Chinese Medicine formula, has been widely used for treating depression since the Ming Dynasty, as recorded in Jingyue Quanshu, but its effectiveness and safety lack comprehensive and objective evaluation. Based on our meta-analysis, we aimed to adequately evaluate the efficacy and risk of CSS by considering the latest clinical literature.

METHODS

Multiple databases, including PubMed, Embase, Web of Science, SinoMed, China National Knowledge Infrastructure, Chongqing VIP, and Wanfang, were used to collect clinical data. The quality of the included clinical studies was assessed using the Cochrane Risk of Bias Tool, and the data were meta-analyzed using Review Manager 5.0 and Stata 17. The data were obtained from a genome-wide association study, and Mendelian randomization (MR) was performed using R Software 4.3.2 with the TwoSampleMR and MR Pleiotropy RESidual Sum and Outlier packages.

RESULTS

A total of 15 studies with 1034 patients and 6 antidepressant drugs were included in this work. Meta-analyses revealed that drug combinations of CSS and antidepressants significantly improved depressive symptoms (weighted mean difference = -4.21; 95% confidence interval [CI]: -5.62--2.81), increased the effective rate (odds ratio [OR] = 3.82; 95% CI: 2.44-6.83), and reduced side effects (OR = -3.55; 95% CI: -5.66--1.43) compared with antidepressant monotherapy. Additionally, compared with antidepressant monotherapy, CSS alone exhibited fewer side effects (95% CI:-9.25--6.95). Like antidepressants, CSS also improved depressive symptoms (weighted mean difference = -0.05; 95% CI: -0.63--0.52) and increased the effective rate (OR = 1.07; 95% CI: 0.52-2.20). Additionally, MR was used to evaluate the safety of traditional antidepressants, as there was a causal association between amitriptyline and body mass index.

CONCLUSION

This analysis demonstrated that compared with traditional antidepressants, CSS combined with antidepressants was more effective and safer for treating depressed patients. MR showed that a causal relationship may exist between amitriptyline and body mass index. Therefore, clinicians should carefully consider the advantages and potential drawbacks of Traditional Chinese Medicine and classic drugs to serve patients better.

Pathogenesis of depression and the potential for traditional Chinese medicine treatment

Depression is a prevalent mental disorder that significantly diminishes quality of life and longevity, ranking as one of the primary causes of disability globally. Contemporary research has explored the potential pathogenesis of depression from various angles, encompassing genetics, neurotransmitter systems, neurotrophic factors, the hypothalamic-pituitary-adrenal axis, inflammation, and intestinal flora, among other contributing factors. In addition, conventional chemical medications are plagued by delayed onset of action, persistent adverse effects, and restricted therapeutic efficacy. In light of these limitations, the therapeutic approach of traditional Chinese medicine (TCM) has gained increasing recognition for its superior effectiveness. Numerous pharmacological and clinical studies have substantiated TCM's capacity to mitigate depressive symptoms through diverse mechanisms. This article attempts to summarize the mechanisms involved in the pathogenesis of depression and to describe the characteristics of herbal medicines (including compounded formulas and active ingredients) for the treatment of depression. It further evaluates their effectiveness by correlating with the multifaceted pathogenesis of depression, thereby furnishing a reference for future research endeavors.

Butyrate as a potential therapeutic agent for neurodegenerative disorders

Maintaining an optimum microbial community within the gastrointestinal tract is intricately linked to human metabolic, immune and brain health. Disturbance to these microbial populations perturbs the production of vital bioactive compounds synthesised by the gut microbiome, such as short-chain fatty acids (SCFAs). Of the SCFAs, butyrate is known to be a major source of energy for colonocytes and has valuable effects on the maintenance of intestinal epithelium and blood brain barrier integrity, gut motility and transit, anti-inflammatory effects, and autophagy induction. Inducing endogenous butyrate production is likely to be beneficial for gut-brain homeostasis and for optimal neuronal function. For these reasons, butyrate has gained interest as a potential therapy for not only metabolic and immunological disorders, but also conditions related to the brain, including neurodegenerative diseases. While direct and indirect sources of butyrate, including prebiotics, probiotics, butyrate pro-drugs and glucosidase inhibitors, offer a promising therapeutic avenue, their efficacy and dosage in neurodegenerative conditions remain largely unknown. Here, we review current literature on effects of butyrate relevant to neuronal function, the impact of butyrate in a range of neurodegenerative diseases and related treatments that may have potential for the treatment of neurodegenerative diseases.

Bacillus coagulans and Clostridium butyricum synergistically alleviate depression in a chronic unpredictable mild stress mouse model through altering gut microbiota and prefrontal cortex gene expression

Introduction: The prevalence of major depressive disorder (MDD) has gradually increased and has attracted widespread attention. The aim of this study was to investigate the effect of a probiotic compound consisting of Bacillus coagulans and Clostridium butyricum, on a mouse depression model. Methods: Mice were subjected to chronic unpredictable mild stress (CUMS) and then treated with the probiotics at different concentrations. And mice received behavior test such as forced swimming test and tail suspension test. After that, all mice were sacrificed and the samples were collected for analysis. Moreover, prefrontal cortex (PFC) gene expression and the gut microbiota among different groups were also analyzed. Results: Probiotics improved depressive-like behavior in CUMS mice, as indicated by decreased immobility time (p < 0.05) in the forced swimming test and tail suspension test. probiotics intervention also increased the level of 5-hydroxytryptamine (5-HT) in the prefrontal cortex and decreased the adrenocorticotropic hormone (ACTH) level in serum. In addition, by comparing the PFC gene expression among different groups, we found that the genes upregulated by probiotics were enriched in the PI3K-Akt signaling pathway in the prefrontal cortex. Moreover, we found that downregulated genes in prefrontal cortex of CUMS group such as Sfrp5 and Angpt2, which were correlated with depression, were reversed by the probiotics. Furthermore, the probiotics altered the structure of the gut microbiota, and reversed the reduction of cob(II)yrinate a,c-diamide biosynthesis I pathway in CUMS group. Several species like Bacteroides caecimuris and Parabacteroides distasoni, whose abundance was significantly decreased in the CUMS group but reversed after the probiotics intervention, showed significantly positive correlation with depression associated genes such as Tbxas1 and Cldn2. Discussion: These findings suggested that CUMS-induced depression-like behavior can be alleviated by the probiotics, possibly through alterations in the PFC gene expression and gut microbiota.

Bupleurum in Treatment of Depression Disorder: A Comprehensive Review

The incidence of depression has been steadily rising in recent years, making it one of the most prevalent mental illnesses. As the pursuit of novel antidepressant drugs captivates the pharmaceutical field, the therapeutic efficacy of Traditional Chinese Medicine (TCM) has been widely explored. Chaihu (Bupleurum) has been traditionally used for liver conditions such as hepatitis, liver inflammation, liver fibrosis, and liver cancer. It is believed to have hepatoprotective effects, promoting liver cell regeneration and protecting against liver damage. In addition, Bupleurum has also been used as a Jie Yu (depression-relieving) medicine in China, Japan, Republic of Korea, and other Asian countries for centuries. This review article aims to summarize the research conducted on the antidepressant properties and mechanisms of Bupleurum, as well as discuss the potential of TCM formulas containing Bupleurum. This review highlights various antidepressant ingredients isolated from Bupleurum, including saikosaponin A, saikosaponin D, rutin, puerarin, and quercetin, each with distinct mechanisms of action. Additionally, Chinese herb prescriptions and extracts containing Bupleurum, such as Chaihu Shugansan, Xiaoyaosan, and Sinisan, are also included due to their demonstrated antidepressant effects. This review reveals that these Bupleurum compounds exhibit antidepressant effects through the regulation of neurotransmitter mechanisms (such as 5-HT and DA), the NMDA (N-methyl-D-aspartate) system, brain-derived neurotrophic factor (BDNF), and other intracellular signaling pathways. Collectively, this comprehensive review provides insights into the multiple applications of Bupleurum in the treatment of depression and highlights its potential as an alternative or complementary approach to traditional therapies. However, it is essential to consider the potential adverse effects and clinical restrictions of Bupleurum despite its promising potential. Further research is needed to elucidate its specific mechanisms of action and evaluate its effectiveness in human subjects.

How traditional Chinese medicine can prevent recurrence of common bile duct stones after endoscopic retrograde cholangiopancreatography?

Common bile duct stones, as a type of cholelithiasis, are a benign biliary obstruction that easily acute abdominalgia, and Endoscopic Retrograde Cholangiopancreatography (ERCP) is usually the first choice for clinical treatment. However, the increasing recurrence rate of patients after treatment is troubling clinicians and patients. For the prevention of recurrence after ERCP, there is no guideline to provide a clear drug regimen, traditional Chinese medicine however has achieved some result in the treatment of liver-related diseases based on the "gut-liver-bile acid axis". On the basis of this, this article discusses the possibility of traditional Chinese medicine to prevent common bile duct stones (CBDS) after ERCP, and we expect that this article will provide new ideas for the prevention of recurrence of CBDS and for the treatment of cholelithiasis-related diseases with traditional Chinese medicine in future clinical and scientific research.

Potential antidepressant effects of Traditional Chinese botanical drug formula Chaihu-Shugan-San and its active ingredients

Background: Depression is a severe mental disorder that poses a significant threat to both the physical and mental wellbeing of individuals. Currently, there are various methods for treating depression, including traditional Chinese herbal formulations like Chaihu-Shugan-San (CSS), which have shown effective antidepressant effects in both clinical and animal research. Objective: This review aims to provide a comprehensive synthesis of evidence related to CSS, considering both preclinical and clinical studies, to uncover its potential multi-level, multi-pathway, and multi-target mechanisms for treating depression and identify its active ingredients. Methods: A thorough search was conducted in electronic databases, including PubMed, MEDLINE, Web of Science, Google Scholar, CNKI, and Wanfang, using keywords such as "Chaihu Shugan" and "depression" to retrieve relevant literature on CSS and its active ingredients. The review process adhered to the PRISMA guidelines. Results: This review consolidates the mechanisms underlying antidepressant effects of CSS and its active ingredients. It emphasizes its involvement in the regulation of monoaminergic neurotransmitter systems, synaptic plasticity, and the hypothalamic-pituitary-adrenal axis, among other aspects. Conclusion: CSS exerts a pivotal role in treating depression through various pathways, including the monoaminergic neurotransmitter system, the hypothalamic-pituitary-adrenal axis, synaptic plasticity, inflammation, brain-derived neurotrophic factor levels, and the brain-gut axis. This review facilitates a comprehensive understanding of the current state of CSS research, fostering an in-depth exploration of the etiological mechanisms of depression and the potential discovery of novel antidepressant drugs.

Bergamot essential oil improves CUMS-induced depression-like behaviour in rats by protecting the plasticity of hippocampal neurons

Bergamot essential oil (BEO) is an extract of the bergamot fruit with significant neuroprotective effect. This study was to investigate the effects and the underlying mechanism of BEO in mitigating depression. GC-MS were used to identify its constituents. Antidepressive properties of BEO were evaluated by sucrose preference test (SPT), force swimming test (FST) and open field test (OFT). Nissl staining was used to determine the number of Nissl bodies in hippocampus (HIPP) of rats. Changes in HIPP dendritic length and dendritic spine density were detected by Golgi-Cox staining. Immunohistochemistry and Western blot were used to detect the postsynaptic density protein-95 (PSD-95) and synaptophysin (SYP) in the HIPP of rats. The enzyme-linked immunosorbent assay was used to determine the 5-hydroxytryptamine (5-HT), insulin-like growth factor 1 (IGF-1) and interleukin-1β (IL-1β) in the HIPP, serum and cerebrospinal fluid (CSF) of rats. Inhaled BEO significantly improved depressive behaviour in chronic unpredictable mild stress (CUMS) rats. BEO increased Nissl bodies, dendritic length and spine density, PSD-95 and SYP protein in the HIPP. Additionally, BEO upregulated serum 5-HT, serum and CSF IGF-1, while downregulating serum IL-1β. Collectively, inhaled BEO mitigates depression by protecting the plasticity of hippocampal neurons, hence, providing novel insights into treatment of depression.

Radix Bupleuri aqueous extract attenuates MK801-induced schizophrenia-like symptoms in mice: Participation of intestinal flora

Schizophrenia (SCZ) is a psychotic mental disorder characterized by cognitive, behavioral, and social impairments. However, current pharmacological treatment regimens are subpar in terms of effectiveness. This study aimed to investigate the function of Radix Bupleuri aqueous extract in SCZ in mouse models. The SCZ mouse model was established by MK-801 injection and feeding of Radix Bupleuri aqueous extract or combined antibiotics. Radix Bupleuri aqueous extract significantly improved the aberrant behaviors and neuronal damage in SCZ mice, upregulated SYP and PSD-95 expression and BDNF levels in hippocampal homogenates, down-regulated DA and 5-HT levels, and suppressed microglial activation in SCZ mice. Moreover, Radix Bupleuri aqueous extract improved the integrity of the intestinal tract barrier. The 16 S rRNA sequencing of feces showed that Radix Bupleuri extract modulated the composition of gut flora. Lactobacillus abundance was decreased in SCZ mice and reversed by Radix Bupleuri aqueous extract administration which exhibited a significant negative correlation with IL-6, IL-1β, DA, and 5-HT, and a significant positive correlation with BDNF levels in hippocampal tissues. The abundance of Parabacteroides and Alloprevotella was increased in SCZ mice. It was reversed by Radix Bupleuri aqueous extract administration, which exhibited a positive correlation with IL-6, IL-1β, and 5-HT and a negative correlation with BDNF. In conclusion, Radix Bupleuri aqueous extract attenuates the inflammatory response in hippocampal tissues and modulates neurotransmitter levels, exerting its neuroprotective effect in SCZ. Meanwhile, the alteration of intestinal flora may be involved in this process, which is expected to be an underlying therapeutic option in treating SCZ.

Bile acid signalling and its role in anxiety disorders

Anxiety disorder is a prevalent neuropsychiatric disorder that afflicts 7.3%~28.0% of the world's population. Bile acids are synthesized by hepatocytes and modulate metabolism via farnesoid X receptor (FXR), G protein-coupled receptor (TGR5), etc. These effects are not limited to the gastrointestinal tract but also extend to tissues and organs such as the brain, where they regulate emotional centers and nerves. A rise in serum bile acid levels can promote the interaction between central FXR and TGR5 across the blood-brain barrier or activate intestinal FXR and TGR5 to release fibroblast growth factor 19 (FGF19) and glucagon-like peptide-1 (GLP-1), respectively, which in turn, transmit signals to the brain via these indirect pathways. This review aimed to summarize advancements in the metabolism of bile acids and the physiological functions of their receptors in various tissues, with a specific focus on their regulatory roles in brain function. The contribution of bile acids to anxiety via sending signals to the brain via direct or indirect pathways was also discussed. Different bile acid ligands trigger distinct bile acid signaling cascades, producing diverse downstream effects, and these pathways may be involved in anxiety regulation. Future investigations from the perspective of bile acids are anticipated to lead to novel mechanistic insights and potential therapeutic targets for anxiety disorders.

Recent Progress in Mass Spectrometry-Based Metabolomics in Major Depressive Disorder Research

Major depressive disorder (MDD) is a serious mental illness with a heavy social burden, but its underlying molecular mechanisms remain unclear. Mass spectrometry (MS)-based metabolomics is providing new insights into the heterogeneous pathophysiology, diagnosis, treatment, and prognosis of MDD by revealing multi-parametric biomarker signatures at the metabolite level. In this comprehensive review, recent developments of MS-based metabolomics in MDD research are summarized from the perspective of analytical platforms (liquid chromatography-MS, gas chromatography-MS, supercritical fluid chromatography-MS, etc.), strategies (untargeted, targeted, and pseudotargeted metabolomics), key metabolite changes (monoamine neurotransmitters, amino acids, lipids, etc.), and antidepressant treatments (both western and traditional Chinese medicines). Depression sub-phenotypes, comorbid depression, and multi-omics approaches are also highlighted to stimulate further advances in MS-based metabolomics in the field of MDD research.

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.

The alteration of gut microbiota in venlafaxine-ameliorated chronic unpredictable mild stress-induced depression in mice

Depression is associated with intestinal dysbiosis. Venlafaxine is a commonly used antidepressant in clinical practice as a serotonin and noradrenaline reuptake inhibitor. However, its effects on gut bacteria in depression remain unclear. Here, we established a mouse model of depression induced by chronic unpredictable mild stress (CUMS), and investigated the alterations of venlafaxine on the gut microbiota and potential key bacteria. Our data show that venlafaxine exerts antidepressant effects by restoring the serotonin (5-HT) system and glutamate (Glu) levels in CUMS mice. Moreover, we revealed that venlafaxine altered the diversity of gut bacteria in CUMS mice, and at genus level, Blautia, Oscillibacter, Tyzzerella, Butyricicoccus, and Enterorhabdus are the key bacteria responsible for venlafaxine-ameliorated depression in mice. Among these potential key bacteria, Blautia, Oscillibacter, and Butyricicoccus are correlated significantly with the 5-HT and 5-hydroxyindoleacetic acid levels; while Tyzzerella is correlated markedly with Glu levels. We further show that venlafaxine affected multiple functional metabolic pathways of gut bacteria in mice with CUMS-induced depression. Our results suggest that venlafaxine possibly ameliorates depression via modulating gut bacteria, and found the potential targets of its antidepressant effects.

Chaihu Shugan San ameliorated cognitive deficits through regulating gut microbiota in senescence-accelerated mouse prone 8

Background: Traditional Chinese medicines exhibit promising preventive effects on Alzheimer's disease. Chaihu Shugan San (CSS) is a well-known traditional herbal formula whose several kinds of ingredients have the potential of ameliorating Alzheimer's disease. The present study aimed to evaluate the effects of CSS on the microbiota-gut-brain axis and cognitive deficits of senescence-accelerated mouse prone 8 (SAMP8) mice as well as investigate the underlying mechanisms. Methods: Thirty 5-month-old SAMP8 mice were randomly divided into the model group (SAMP8), CSS low-dose treatment group (CSSL), and CSS high-dose treatment group (CSSH). Ten SAMR1 mice were used as the normal control, and ten SAMP8 mice treated with donepezil were used as the positive control of cognitive function. CSS was orally administrated to SAMP8 mice for 8 weeks. The Morris water maze test was used to evaluate cognitive function. Histological staining was used to observe neuronal injury and Aβ deposition. Transmission electron microscopy was used to observe the synaptic ultrastructure. 16S rRNA gene analysis was performed to measure the changes in intestinal microbiota. Results: The results showed that CSS significantly improved the learning function and memory deficits of aged SAMP8 mice in the Morris water maze examination. CSS ameliorated neuronal injury, synaptic injuries, and Aβ deposition in the brain of SAMP8 mice. In addition, CSS also significantly improved microbiota composition in terms of elevating Lactobacillus reuteri and decreasing Staphylococcus xylosus in the feces of aged SAMP8 mice. Conclusion: These findings suggested that CSS might have a preventive potential for cognitive deficits in aging through regulating gut microbiota, which paved the way for the application of CSS for prevention and therapeutic purposes for mild cognitive impairment as well as Alzheimer's disease.

Intestinal Escherichia coli and related dysfunction as potential targets of Traditional Chinese Medicine for respiratory infectious diseases

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese medicine (TCM) has saved countless lives and maintained human health over its long history, especially in respiratory infectious diseases. The relationship between the intestinal flora and the respiratory system has been a popular research topic in recent years. According to the theory of the "gut-lung axis" in modern medicine and the idea that "the lung stands in an interior-exterior relationship with the large intestine" in TCM, gut microbiota dysbiosis is a contributing factor to respiratory infectious diseases, and there is potential means for manipulation of the gut microbiota in the treatment of lung diseases. Emerging studies have indicated intestinal Escherichia coli (E. coli) overgrowth in multiple respiratory infectious diseases, which could exacerbate respiratory infectious diseases by disrupting immune homeostasis, the gut barrier and metabolic balance. TCM is an effective microecological regulator, that can regulate the intestinal flora including E. coli, and restore the balance of the immune system, gut barrier, and metabolism.

AIM OF THE REVIEW

This review discusses the changes and effects of intestinal E. coli in respiratory infection, as well as the role of TCM in the intestinal flora, E. coli and related immunity, the gut barrier and the metabolism, thereby suggesting the possibility of TCM therapy regulating intestinal E. coli and related immunity, the gut barrier and the metabolism to alleviate respiratory infectious diseases. We aimed to make a modest contribution to the research and development of new therapies for intestinal flora in respiratory infectious diseases and the full utilization of TCM resources. Relevant information about the therapeutic potential of TCM to regulate intestinal E. coli against diseases was collected from PubMed, China National Knowledge Infrastructure (CNKI), and so on. The Plants of the World Online (https://wcsp.science.kew.org) and the Plant List (www.theplantlist.org) databases were used to provide the scientific names and species of plants.

RESULTS

Intestinal E. coli is a very important bacterium in respiratory infectious diseases that affects the respiratory system through immunity, the gut barrier and the metabolism. Many TCMs can inhibit the abundance of E. coli and regulate related immunity, the gut barrier and the metabolism to promote lung health.

CONCLUSION

TCM targeting intestinal E. coli and related immune, gut barrier, and metabolic dysfunction could be a potential therapy to promote the treatment and prognosis of respiratory infectious diseases.

Prophylactic effect of Tongxieyaofang polysaccharide on depressive behavior in adolescent male mice with chronic unpredictable stress through the microbiome-gut-brain axis

Major depression disorder is more common among adolescents and is a primary reason for suicide in adolescents. Some antidepressants are ineffective and may possess side effects. Therefore, developing an adolescent antidepressant is the need of the hour. We designed the stress model of adolescent male mice induced by chronic unpredictable stress (CUS). The mice were treated using Tongxieyaofang neutral polysaccharide (TXYF-NP), Tongxieyaofang acidic polysaccharide (TXYF-AP), TXYF-AP + TXYF-NP and fructooligosaccharide + galactooligosaccharides to determine their body weight, behavior, and serum hormone levels. RT-qPCR was used to detect the gene expression of Crhr1, Nr3c1, and Nr3c2 in the hypothalamus and hippocampus and the gene expression of glutamic acid and γ-aminobutyric acid-related receptors in the hippocampus. RT-qPCR, Western blot, and ELISA detected tryptophan metabolism in the colon, serum, and hippocampus. 16s rDNA helped sequence colon microflora, and non-targeted metabolomics enabled the collection of metabolic profiles of colon microflora. In adolescent male mice, CUS induced depression-like behavior, hypothalamic-pituitary-adrenal axis hyperactivity, hippocampal tissue damage, abnormal expression of its related receptors, and dysregulation of tryptophan metabolism. The 16s rDNA and non-targeted metabolomics revealed that CUS led to colon microflora disorder and bile acid metabolism abnormality. Tongxieyaofang polysaccharide could improve the bacterial community and bile acid metabolism disorder by upregulating the relative abundance of Lactobacillus gasseri, Lachnospiraceae bacterium 28-4, Bacteroides and Ruminococcaceae UCG-014 while preventing CUS-induced changes. TXYF-P can inhibit depression-like behavior due to CUS by regulating colonic microflora and restoring bile acid metabolism disorder. Thus, based on the different comparisons, TXYF-NP possessed the best effect.