The gateway reflex regulates tissue-specific autoimmune diseases.

The dynamic interaction and movement of substances and cells between the central nervous system (CNS) and peripheral organs are meticulously controlled by a specialized vascular structure, the blood-brain barrier (BBB). Experimental and clinical research has shown that disruptions in the BBB are characteristic of various neuroinflammatory disorders, including multiple sclerosis. We have been elucidating a mechanism termed the "gateway reflex" that details the entry of immune cells, notably autoreactive T cells, into the CNS at the onset of such diseases. This process is initiated through local neural responses to a range of environmental stimuli, such as gravity, electricity, pain, stress, light, and joint inflammation. These stimuli specifically activate neural pathways to open gateways at targeted blood vessels for blood immune cell entry. The gateway reflex is pivotal in managing tissue-specific inflammatory diseases, and its improper activation is linked to disease progression. In this review, we present a comprehensive examination of the gateway reflex mechanism.

Microbiome and metabolome reveal the metabolic and microbial variations induced by depression and constipation.

BACKGROUND: Depressed patients are often accompanied with constipation symptoms, and vice versa. However, the underlying mechanisms of such a bidirectional correlation have remained elusive. We aim to reveal the possible correlations between depression and constipation from the perspectives of gut microbiome and plasma metabolome. METHODS: We constructed the depressed model and the constipated model of rats, respectively. First, we measured the locomotor activity status and the gastrointestinal functions of rats. And then, nuclear magnetic resonance plasma metabolomics was applied to reveal the shared and the unique metabolites of depression and constipation. In addition, 16 S ribosomal RNA gene sequencing was used to detect the impacts of constipation and depression on gut microbiota of rats. Finally, a multiscale and multifactorial network, that is, the 'phenotypes - differential metabolites - microbial biomarkers' integrated network, was constructed to visualise the mechanisms of connections between depression and constipation. RESULTS: We found that spontaneous locomotor activity and gastrointestinal functions of both depressed rats and constipated rats significantly decreased. Further, eight metabolites and 14 metabolites were associated depression and constipation, respectively. Among them, seven metabolites and four metabolic pathways were shared by constipation and depression, mainly perturbing energy metabolism and amino acid metabolism. Additionally, depression and constipation significantly disordered the functions and the compositions of gut microbiota of rats, and decreased the ratio of Firmicutes to Bacteroidetes. CONCLUSION: The current findings provide multiscale and multifactorial perspectives for understanding the correlations between depression and constipation, and demonstrate new mechanisms of comorbidity of depression and constipation.

Anti-depressive effects of Xiaoyaosan, Shugan and Jianpi herbal treatments: Role on the gut microbiome of CUMS rats.

BACKGROUND: Xiaoyaosan (XYS), a classic traditional Chinese medicine (TCM) prescription that contained eight Chinese herbs, has been used for treating depression for thousands of years. Yet, the underlying mechanisms are still unclear, which need to be investigated from various perspectives. Disassembling a prescription is one of the effective approaches to study the effects and the mechanisms of TCM prescriptions. By disassembling the prescription, we can find effective combinations of individual herbs to simplify the scale of a given prescription. Accordingly, herein, XYS was disassembled into Shugan and Jianpi groups. PURPOSE: This study aimed to explore the anti-depressive effects of XYS and its disassembled groups on the digestive system functions and the cecal microbiota of rats. METHODS: XYS was divided into two efficacy groups, i.e., the Shugan (SG) and the Jianpi (JP) groups. A depression model was applied by using the chronic unpredictable mild stress (CUMS) method. Various classic behavioral tests were performed to assess the anti-depressive effects of the XYS, the SG, and the JP. Afterward, the effects of the three groups on the digestive system functions and the cecum microbiota of depression rats were evaluated. On top of this, correlation analyses between behavioral and digestive system function indexes and cecum microbiota were conducted. RESULTS: The XYS, the SG, and the JP had significant callback effects on depressive behaviors and gastrointestinal dysfunctions of CUMS rats. The compositions of the gut bacterial community were variable among the five groups. The community composition of the SG was the most similar to that of NC, followed by the XYS and the JP. At phylum, family, and genus levels, 31 potential microbial biomarkers associated with CUMS were identified. Twenty biomarkers were significantly reversed by the SG while 16 and 11 biomarkers were reversed by the XYS and the JP, respectively. The results of degrees of regulatory effects showed that the SG had the highest efficacy index (EI) than the XYS and the JP. CONCLUSION: Regarding the regulation of cecal microbiota of depression rats, the SG treatment was better than XYS and JP. Therefore, SG could be used individually for the clinical treatment of depression, especially in patients with gastrointestinal and gut microbiota disorders.

A combination of cecum microbiome and metabolome in CUMS depressed rats reveals the antidepressant mechanism of traditional Chinese medicines: A case study of Xiaoyaosan.

ETHNOPHARMACOLOGICAL RELEVANCE: Xiaoyaosan (XYS), a representative and classic prescription in traditional Chinese medicines (TCMs), has been used for thousands of years for treating depression. The anti-depression effect of XYS has been demonstrated both clinically and experimentally. However, it is still unclear that whether XYS could regulate the abnormalities of gut microbiota and metabolites of cecum induced by depression, and in which way. This study aimed to explore the underlying mechanism of the anti-depressant effects of XYS from the perspective of cecal microbiota and metabolites. MATERIALS AND METHODS: Chronic unpredictable mild stress (CUMS)-induced depression-like rats were used as the depression animal model. Various classic behavioral tests were performed to assess the anti-depressant effects of XYS. Additionally, the composition, the richness, and the diversity of the cecum microbiota were assessed by 16S rRNA gene sequencing technology. Besides, the metabolic profiling of cecum samples was analyzed by 1H-NMR metabolomics. Multivariate data analysis was then applied to screen the differential metabolites and to characterize the changes in cecum metabolites. Moreover, a correlation analysis between differential metabolites and crucial microbiota was conducted. RESULTS: XYS significantly improved depressive behaviors and the abnormal diversity of cecum microbiota induced by CUMS. At the phylum level, XYS could significantly increase the abundance of Firmicutes while decrease the abundance of Actinobacteria in depressed rats. XYS significantly regulated the abundances of 9 out of 13 potential microbial biomarkers at the genus level. Cecal metabolomics showed that XYS could also regulate the abnormal levels of alanine, proline, lactate, and valine of depression rats. CONCLUSIONS: This study revealed, for the first time, from the perspectives of microbiota and cecum metabolites, the anti-depression mechanisms of XYS. This study is of significance for not only comprehensively understanding the anti-depression effects and mechanisms of XYS, but also for providing a research approach for revealing the underlying mechanisms of action of TCMs, i.e. to apply a combination of 16S rRNA gene sequencing and metabolomics.

Hepatic metabolomics of the compatibility effect of Xiaoyaosan on CUMS-induced depression based on the TCM theory of "Treating Diseases via Regulating the Liver's Function".

This study aimed to demonstrate the scientific connotations and compatibility effects of Xiaoyaosan (XYS) based on the theory of "Treating Diseases via Regulating the Liver's Function" by hepatic metabolomics. XYS was divided into two efficacy groups, i.e. the Shugan (SG) and the Jianpi (JP) groups, according to the strategy of "Efficacy Compositions". The chronic unpredictable mild stress (CUMS) depression model was constructed. A 1H NMR-based hepatic metabolomics approach coupled with multivariate data (MVD) analysis was performed. Meanwhile, relative distance (RD) and Efficacy Index (EI) were calculated. XYS and its efficacy groups significantly reversed the abnormality of behavior and hepatic metabolomics of depression rats, but to different degrees. The results of ethology and metabolomics showed the same order, i.e. XYS > JP > SG. Two metabolites, i.e. tyrosine and malate, were regulated by all the treatment groups. Four metabolites were significantly regulated only by XYS group. Of note, the results showed the two efficacy groups of XYS exhibited synergistic anti-depression effects, and glutamate, malate and taurine could be the key hepatic metabolites for these synergistic effects. The current study not only complements and consummates the mechanisms of depression and the anti-depression effects of XYS from the perspective of hepatic metabolomics, but also lays a solid foundation for comprehensively and deeply understanding the compatibility effects of XYS against depression, especially from the points of view of compatibility in Traditional Chinese medicine (TCM) theory and synergism in modern medicine theory.

Serum metabolomics reveals compatibility rules of the antidepressant effects of Xiaoyaosan and its efficacy groups.

Traditional Chinese medicines (TCMs) have attracted more attentions in the treatment of depression. Xiaoyaosan (XYS), a classic anti-depression TCM prescription, contains eight herbs. However, the compatibility effects of XYS in modern pharmacology need to be investigated in depth. In this study, the chronic unpredictable mild stress (CUMS) depression-like model was constructed. Afterwards, XYS was divided into the Shugan and the Jianpi groups according to the research strategy ofefficacy groups. Meanwhile, a proton nuclear magnetic resonance spectrometry (1H NMR) based serum metabolomics was applied. XYS and its efficacy groups significantly regulated the abnormal levels of differential metabolites related to depression, but to different degrees. Metabolic profiling by orthogonal partial least squares discriminant analysis showed that XYS at high dose (XH) exhibited the strongest effects than other treatment groups. Ten metabolites related to depression were identified as differential metabolites. Besides, relative distance (Rd) was calculated to quantitatively evaluate the effects. We found that XH group had the highest Rd value. Moreover, among the five metabolic pathways of depression, XYS and Jianpi groups significantly regulated all pathways while Shugan group regulated four pathways. These findings lay a solid foundation for comprehensively and deeply understanding the compatibility effects of XYS against depression.

The synergistic anti-depression effects of different efficacy groups of Xiaoyaosan as demonstrated by the integration of network pharmacology and serum metabolomics.

Compatibility investigations are vital but also the most difficult aspect of traditional Chinese medicine (TCM) prescriptions. Previous researches have demonstrated that Xiaoyaosan (XYS) is an effective treatment for depression. However, the compatibility rules of XYS and the underlying mechanisms remain unclear. Herein, we combined network pharmacology and serum metabolomics to investigate the scientific connotations and the compatibility effects of XYS. First, the Traditional Chinese Medicine Systems Pharmacology (TCMSP) and the GeneCards databases were applied to identify the chemical components and the putative targets of XYS, and its efficacy groups. We then analyzed the herb-component-target pathways and constructed PPI networks. Potential pathways were determined by gene ontology (GO) and pathway enrichment analyses. Additionally, a chronic unpredictable mild stress (CUMS) model was applied on rats. A proton nuclear magnetic resonance spectrometry (1H NMR) based serum metabolomics was then used to identify potential metabolites and the corresponding pathways that were involved in depression and the potential anti-depression effects of XYS and its efficacy groups. A total of 121 components of XYS and 111 targets were associated with depression. Additionally, we screened 105 targets of 24 components in Shugan (SG) group and 106 targets of 95 components in Jianpi (JP) group. 13 targets were common to all three groups. Protein-protein interaction network analysis showed that Caspase-3 and Nitric oxide synthase-3 were nodes that overlapped with proteins known to be associated with depression. Pathway enrichment analysis further indicated that the putative targets of XYS and its efficacy groups mostly participated in pathways associated with cancer. Also, XYS and its efficacy groups significantly reversed abnormalities of serum metabolites and metabolic pathways, but to different degrees. Overall, different efficacy groups of XYS exhibit synergistic anti-depression effects and contribute to the whole prescription against depression. This study shows that the combination of network pharmacology and metabolomics is an effective approach to demonstrate scientific connotations and compatibility of TCMs from a holistic perspective.

Deciphering the compatibility rules of traditional Chinese medicine prescriptions based on NMR metabolomics: A case study of Xiaoyaosan.

ETHNOPHARMACOLOGICAL RELEVANCE: Xiaoyaosan (XYS), a represent and classic TCM prescription, consists of Radix Bupleuri, Radix Angelicae Sinensis, Radix Paeoniae Alba, Rhizoma Atractylodis Macrocephalae, Poria, Herba Menthae, Rhizoma Zingiberis Recens and Radix Glycyrrhizae. XYS can sooth the liver and strengthen the spleen through improving the circulation of qi and nourishing blood according to the TCM theory, therefore exhibiting anti-depression effects. AIM OF THE STUDY: This study was conducted to investigate the compatibility rule of antidepressant effect of XYS by using both the "Efficacy Compositions" research strategy and fecal metabolomics approach. MATERIALS AND METHODS: XYS was divided into two efficacy groups, i.e. the Shugan (SG) and the Jianpi (JP) groups, according to the efficacies of both XYS and the eight herbs recorded in the TCM theory and the research strategy of "Efficacy Compositions". A CUMS-induced depression model was constructed, where rats were randomly divided into 5 groups: negative control (NC), CUMS model (MS), XYS, SG, and JP. Multivariate data analysis including Principal Components Analysis (PCA) and Orthogonal Partial Least Squares-Discriminate Analysis (OPLS-DA) was utilized. Efficacy Index (EI) was calculated. RESULTS: Metabolic profiling by PCA showed that XYS exhibited the strongest effect than the two efficacy groups, locating closest to the control group. OPLS-DA showed 10 metabolites were identified as potential biomarkers for the CUMS-induced depression. 8 potential biomarkers were significantly reversed by XYS while 5 and 4 biomarkers were reversed by SG and JP, respectively. The results of regulatory degrees showed that XYS had the highest EI than SG and JP. Concerning metabolic pathways, XYS regulated all the seven metabolic pathways associated with CUMS-induced depression, while SG and JP groups regulated six and three pathways, respectively. CONCLUSIONS: The antidepressant effect of XYS was stronger than that of SG and JP. The combined effects of SG and JP brought the integrated antidepressant effect of XYS. This study suggests that a combination of "Efficacy Compositions" strategy and metabolomics approach has great potentials in comprehensively and deeply understanding the scientific connotation of the compatibility rule of TCM prescriptions.