The microbiota-gut-brain axis and its modulation in the therapy of depression: comparison of efficacy of conventional drugs and traditional Chinese medicine approaches

Treatment response of venlafaxine induced alterations of gut microbiota and metabolites in a mouse model of depression

Antidepressants remain the first-line treatment for depression. However, the factors influencing medication response are still unclear. Accumulating evidence implicates an association between alterations in gut microbiota and antidepressant response. Therefore, the aim of this study is to investigate the role of the gut microbiota-brain axis in the treatment response of venlafaxine. After chronic social defeat stress and venlafaxine treatment, mice were divided into responders and non-responders groups. We compared the composition of gut microbiota using 16 S ribosomal RNA sequencing. Meanwhile, we quantified metabolomic alterations in serum and hippocampus, as well as hippocampal neurotransmitter levels using liquid chromatography-mass spectrometry. We found that the abundances of 29 amplicon sequence variants (ASVs) were significantly altered between the responders and non-responders groups. These ASVs belonged to 8 different families, particularly Muribaculaceae. Additionally, we identified 38 and 39 differential metabolites in serum and hippocampus between the responders and non-responders groups, respectively. Lipid, amino acid, and purine metabolisms were enriched in both serum and hippocampus. In hippocampus, the concentrations of tryptophan, phenylalanine, gamma-aminobutyric acid, glutamic acid, and glutamine were increased, while the level of succinic acid was decreased in the responders group, compared with the non-responders group. Our findings suggest that the gut microbiota may play a role in the antidepressant effect of venlafaxine by modulating metabolic processes in the central and peripheral tissues. This provides a novel microbial and metabolic framework for understanding the impact of the gut microbiota-brain axis on antidepressant response.

Reveal the potent antidepressant effects of Zhi-Zi-Hou-Pu Decoction based on integrated network pharmacology and DDI analysis by deep learning

Background and objective

The multi-targets and multi-components of Traditional Chinese medicine (TCM) coincide with the complex pathogenesis of depression. Zhi-Zi-Hou-Pu Decoction (ZZHPD) has been approved in clinical medication with good antidepression effects for centuries, while the mechanisms under the iceberg haven't been addressed systematically. This study explored its inner active ingredients - potent pharmacological mechanism - DDI to explore more comprehensively and deeply understanding of the complicated TCM in treatment.

Methods

This research utilized network pharmacology combined with molecular docking to identify pharmacological targets and molecular interactions between ZZHPD and depression. Verification of major active compounds was conducted through UPLC-Q-TOF-MS/MS and assays on LPS-induced neuroblastoma cells. Additionally, the DDIMDL model, a deep learning-based approach, was used to predict DDIs, focusing on serum concentration, metabolism, effectiveness, and adverse reactions.

Results

The antidepressant mechanisms of ZZHPD involve the serotonergic synapse, neuroactive ligand-receptor interaction, and dopaminergic synapse signaling pathways. Eighteen active compounds were identified, with honokiol and eriocitrin significantly modulating neuronal inflammation and promoting differentiation of neuroimmune cells through genes like COMT, PI3KCA, PTPN11, and MAPK1. DDI predictions indicated that eriocitrin's serum concentration increases when combined with hesperidin, while hesperetin's metabolism decreases with certain flavonoids. These findings provide crucial insights into the nervous system's effectiveness and potential cardiovascular or nervous system adverse reactions from core compound combinations.

Conclusions

This study provides insights into the TCM interpretation, drug compatibility or combined medication for further clinical application or potential drug pairs with a cost-effective method of integrated network pharmacology and deep learning.

Bifidobacteria with indole-3-lactic acid-producing capacity exhibit psychobiotic potential via reducing neuroinflammation

The escalating global prevalence of depression demands effective therapeutic strategies, with psychobiotics emerging as a promising solution. However, the molecular mechanisms governing the neurobehavioral impact of psychobiotics remain elusive. This study reveals a significant reduction in hippocampal indole-3-lactic acid (ILA) levels in depressed mice, which is ameliorated by the psychobiotic Bifidobacterium breve. In both human subjects and mice, the ILA increase in the circulatory system results from bifidobacteria supplementation. Further investigation identifies the key aromatic lactate dehydrogenase (Aldh) gene and pathway in bifidobacteria responsible for ILA production. Importantly, the antidepressant effects are nullified in the Aldh mutants compared to the wild-type strain. At the bifidobacteria species level, those with Aldh exhibit heightened antidepressant effects. Finally, this study emphasizes the antidepressant efficacy of psychobiotic-derived ILA, potentially mediated by aryl hydrocarbon receptor (AhR) signaling activation to alleviate neuroinflammation. This study unveils the molecular and genetic foundations of psychobiotics' antidepressant effects, offering insights for microbial therapies targeting mood disorders.

Integrated gut microbiome and metabolomic analyses elucidate the therapeutic mechanisms of Suanzaoren decoction in insomnia and depression models

Insomnia and depression are psychiatric disorders linked to substantial health burdens. The gut microbiome and metabolomic pathways are increasingly recognized as key contributors to these conditions' pathophysiology. Suanzaoren Decoction (SZRD), a traditional Chinese herbal formulation, has demonstrated significant therapeutic benefits for both insomnia and depression. This study aims to elucidate the mechanistic effects of SZRD on insomnia and depression by integrating gut microbiome and metabolomic analyses and to assess the differential impacts of SZRD dosages. Using ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS), we identified 66 chemical constituents within SZRD. Behavioral assays indicated that low-dose SZRD (LSZRD) significantly ameliorated insomnia symptoms in rat models, whereas high-dose SZRD (HSZRD) markedly improved depressive behaviors. 16S rRNA sequencing revealed that SZRD modulated gut microbiome dysbiosis induced by insomnia and depression, characterized by an increased abundance of short-chain fatty acid (SCFA)-producing genera. Metabolomic profiling demonstrated reduced plasma amino acid metabolites and disrupted γ-aminobutyric acid (GABA) and L-glutamic acid metabolism in the hippocampus of affected rats. SZRD administration restored fecal SCFA levels and ameliorated metabolic imbalances in both plasma and hippocampal tissues. These findings underscore the pivotal role of gut microbiome modulation and metabolic regulation in the therapeutic effects of SZRD, providing a scientific basis for its use in treating insomnia and depression.

Molecular mechanism and therapeutic strategy of bile acids in Alzheimer's disease from the emerging perspective of the microbiota-gut-brain axis

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by the accumulation of amyloid-β outside neurons and Tau protein inside neurons. Various pathological mechanisms are implicated in AD, including brain insulin resistance, neuroinflammation, and endocrinal dysregulation of adrenal corticosteroids. These factors collectively contribute to neuronal damage and destruction. Recently, bile acids (BAs), which are metabolites of cholesterol, have shown neuroprotective potential against AD by targeting the above pathological changes. BAs can enter the systematic circulation and cross the blood-brain barrier, subsequently exerting neuroprotective effects by targeting several endogenous receptors. Additionally, BAs interact with the microbiota-gut-brain (MGB) axis to improve immune and neuroendocrine function during AD episodes. Gut microbes impact BA signaling in the brain through their involvement in BA biotransformation. In this review, we summarize the role and molecular mechanisms of BAs in AD while considering the MGB axis and propose novel strategies for preventing the onset and progression of AD.

The communication mechanism of the gut-brain axis and its effect on central nervous system diseases: A systematic review

Gut microbiota is involved in intricate and active metabolic processes the host's brain function, especially its role in immune responses, secondary metabolism, and symbiotic connections with the host. Gut microbiota can promote the production of essential metabolites, neurotransmitters, and other neuroactive chemicals that affect the development and treatment of central nervous system diseases. This article introduces the relevant pathways and manners of the communication between the brain and gut, summarizes a comprehensive overview of the current research status of key gut microbiota metabolites that affect the functions of the nervous system, revealing those adverse factors that affect typical communication between the brain-gut axis, and outlining the efforts made by researchers to alleviate these neurological diseases through targeted microbial interventions. The relevant pathways and manners of communication between the brain and gut contribute to the experimental design of new treatment plans and drug development. The factors that may cause changes in gut microbiota and affect metabolites, as well as current intervention methods are summarized, which helps improve gut microbiota brain dialogue, prevent adverse triggering factors from interfering with the gut microbiota system, and minimize neuropathological changes.

Therapeutic approaches targeting the gut microbiota in ischemic stroke: current advances and future directions

Ischemic stroke (IS) is the predominant form of stroke pathology, and its clinical management remains constrained by therapeutic time frame. The gut microbiota (GM), comprising a multitude of bacterial and archaeal cells, surpasses the human cell count by approximately tenfold and significantly contributes to the human organism's growth, development, and overall well-being. The microbiota-gut-brain axis (MGBA) in recent years has established a strong association between gut microbes and the brain, demonstrating their intricate involvement in the progression of IS. The regulation of IS by the GM, encompassing changes in composition, abundance, and distribution, is multifaceted, involving neurological, endocrine, immunological, and metabolic mechanisms. This comprehensive understanding offers novel insights into the therapeutic approaches for IS. The objective of this paper is to examine the mechanisms of interaction between the GM and IS in recent years, assess the therapeutic effects of the GM on IS through various interventions, such as dietary modifications, probiotics, fecal microbiota transplantation, and antibiotics, and offer insights into the potential clinical application of the GM in stroke treatment.

Co-decoction of Lilii bulbus and Radix Rehmannia Recens and its key bioactive ingredient verbascoside inhibit neuroinflammation and intestinal permeability associated with chronic stress-induced depression via the gut microbiota-brain axis

BACKGROUND

Gut microbiota plays a critical role in the pathogenesis of depression and are a therapeutic target via maintaining the homeostasis of the host through the gut microbiota-brain axis (GMBA). A co-decoction of Lilii bulbus and Radix Rehmannia Recens (LBRD), in which verbascoside is the key active ingredient, improves brain and gastrointestinal function in patients with depression. However, in depression treatment using verbascoside or LBRD, mechanisms underlying the bidirectional communication between the intestine and brain via the GMBA are still unclear.

PURPOSE

This study aimed to examine the role of verbascoside in alleviating depression via gut-brain bidirectional communication and to study the possible pathways involved in the GMBA.

METHODS

Key molecules and compounds involved in antidepressant action were identified using HPLC and transcriptomic analyses. The antidepressant effects of LBRD and verbascoside were observed in chronic stress induced depression model by behavioural test, neuronal morphology, and synaptic dendrite ultrastructure, and their neuroprotective function was measured in corticosterone (CORT)-stimulated nerve cell injury model. The causal link between the gut microbiota and the LBRD and verbascoside antidepressant efficacy was evaluate via gut microbiota composition analysis and faecal microbiota transplantation (FMT).

RESULTS

LBRD and Verbascoside administration ameliorated depression-like behaviours and synaptic damage by reversing gut microbiota disturbance and inhibiting inflammatory responses as the result of impaired intestinal permeability or blood-brain barrier leakiness. Furthermore, verbascoside exerted neuroprotective effects against CORT-induced cytotoxicity in an in vitro depression model. FMT therapy indicated that verbascoside treatment attenuated gut inflammation and central nervous system inflammatory responses, as well as eliminated neurotransmitter and brain-gut peptide deficiencies in the prefrontal cortex by modulating the composition of gut microbiota. Lactobacillus, Parabacteroides, Bifidobacterium, and Ruminococcus might play key roles in the antidepressant effects of LBRD via the GMBA.

CONCLUSION

The current study elucidates the multi-component, multi-target, and multi-pathway therapeutic effects of LBRD on depression by remodeling GMBA homeostasis and further verifies the causality between gut microbiota and the antidepressant effects of verbascoside and LBRD.

Pharmacological mechanism of natural antidepressants: The role of mitochondrial quality control

BACKGROUND

Depression is a mental illness characterized by persistent sadness and a reduced capacity for pleasure. In clinical practice, SSRIs and other medications are commonly used for therapy, despite their various side effects. Natural products present distinct advantages, including synergistic interactions among multiple components and targeting multiple pathways, suggesting their tremendous potential in depression treatment. Imbalance in mitochondrial quality control (MQC) plays a significant role in the pathology of depression, emphasizing the importance of regulating MQC as a potential intervention strategy in addressing the onset and progression of depression. However, the role and mechanism through which natural products regulate MQC in depression treatments still need to be comprehensively elucidated, particularly in clinical and preclinical settings.

PURPOSE

This review was aimed to summarize the findings of recent studies and outline the pharmacological mechanisms by which natural products modulate MQC to exert antidepressant effects. Additionally, it evaluated current research limitations and proposed new strategies for future preclinical and clinical applications in the depression domain.

METHODS

To study the main pharmacological mechanisms underlying the regulation of MQC by natural products in the treatment of depression, we conducted a thorough search across databases such as PubMed, Web of Science, and ScienceDirect databases to classify and summarize the relationship between MQC and depression, as well as the regulatory mechanisms of natural products.

RESULTS

Numerous studies have shown that irregularities in the MQC system play an important role in the pathology of depression, and the regulation of the MQC system is involved in antidepressant treatments. Natural products mainly regulate the MQC system to induce antidepressant effects by alleviating oxidative stress, balancing ATP levels, promoting mitophagy, maintaining calcium homeostasis, optimizing mitochondrial dynamics, regulating mitochondrial membrane potential, and enhancing mitochondrial biogenesis.

CONCLUSIONS

We comprehensively summarized the regulation of natural products on the MQC system in antidepressants, providing a unique perspective for the application of natural products within antidepressant therapy. However, extensive efforts are imperative in clinical and preclinical investigations to delve deeper into the mechanisms underlying how antidepressant medications impact MQC, which is crucial for the development of effective antidepressant treatments.

Traditional Chinese herbal formulas modulate gut microbiome and improve insomnia in patients with distinct syndrome types: insights from an interventional clinical study

Background

Traditional Chinese medicine (TCM) comprising herbal formulas has been used for millennia to treat various diseases, such as insomnia, based on distinct syndrome types. Although TCM has been proposed to be effective in insomnia through gut microbiota modulation in animal models, human studies remain limited. Therefore, this study employs machine learning and integrative network techniques to elucidate the role of the gut microbiome in the efficacies of two TCM formulas - center-supplementing and qi-boosting decoction (CSQBD) and spleen-tonifying and yin heat-clearing decoction (STYHCD) - in treating insomnia patients diagnosed with spleen qi deficiency and spleen qi deficiency with stomach heat.

Methods

Sixty-three insomnia patients with these two specific TCM syndromes were enrolled and treated with CSQBD or STYHCD for 4 weeks. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI) and Insomnia Severity Index (ISI) every 2 weeks. In addition, variations in gut microbiota were evaluated through 16S rRNA gene sequencing. Stress and inflammatory markers were measured pre- and post-treatment.

Results

At baseline, patients exhibiting only spleen qi deficiency showed slightly lesser severe insomnia, lower IFN-α levels, and higher cortisol levels than those with spleen qi deficiency with stomach heat. Both TCM syndromes displayed distinct gut microbiome profiles despite baseline adjustment of PSQI, ISI, and IFN-α scores. The nested stratified 10-fold cross-validated random forest classifier showed that patients with spleen qi deficiency had a higher abundance of Bifidobacterium longum than those with spleen qi deficiency with stomach heat, negatively associated with plasma IFN-α concentration. Both CSQBD and STYHCD treatments significantly improved sleep quality within 2 weeks, which lasted throughout the study. Moreover, the gut microbiome and inflammatory markers were significantly altered post-treatment. The longitudinal integrative network analysis revealed interconnections between sleep quality, gut microbes, such as Phascolarctobacterium and Ruminococcaceae, and inflammatory markers.

Conclusion

This study reveals distinct microbiome profiles associated with different TCM syndrome types and underscores the link between the gut microbiome and efficacies of Chinese herbal formulas in improving insomnia. These findings deepen our understanding of the gut-brain axis in relation to insomnia and pave the way for precision treatment approaches leveraging TCM herbal remedies.

Quercetin increases the antidepressant-like effects of sclareol and antagonizes diazepam in thiopental sodium-induced sleeping mice: A possible GABAergic transmission intervention

Quercetin is the most common polyphenolic flavonoid present in fruits and vegetables demonstrating versatile health-promoting effects. This study aimed to examine the effects of quercetin (QR) and sclareol (SCL) on the thiopental sodium (TS)-induced sleeping and forced swimming test (FST) mouse models. SCL (1, 5, and 10 mg/kg, p.o.) or QR (50 mg/kg, p.o.) and/or diazepam (DZP) (3 mg/kg, i.p.) were employed. After 30 min of TS induction, individual or combined effects on the animals were checked. In the FST test, the animals were subjected to forced swimming after 30 min of administration of the test and/or controls for 5 min. In this case, immobility time was measured. In silico studies were conducted to evaluate the involvement of GABA receptors. SCL (5 and 10 mg/kg) significantly increased the latency and decreased sleeping time compared to the control in the TS-induced sleeping time study. DZP (3 mg/kg) showed a sedative-like effect in animals in both sleeping and FST studies. QR (50 mg/kg) exhibited a similar pattern of activity as SCL. However, its effects were more prominent than those of SCL groups. SCL (10 mg/kg) altered the DZP-3-mediated effects. SCL-10 co-treated with QR-50 significantly (p < 0.05) increased the latency and decreased sleep time and immobility time, suggesting possible synergistic antidepressant-like effects. In silico studies revealed that SCL and QR demonstrated better binding affinities with GABAA receptor, especially α2, α3, and α5 subunits. Both compounds also exhibited good ADMET and drug-like properties. In animal studies, the both compounds worked synergistically to provide antidepressant-like effects in a slightly different fashion. As a conclusion, the combined administration of SCL and QR may be used in upcoming neurological clinical trials, according to in vivo and in silico findings. However, additional investigation is necessary to verify this behavior and clarify the potential mechanism of action.

The anti-depression effect and potential mechanism of the petroleum ether fraction of CDB: Integrated network pharmacology and metabolomics

The combination of Chaidangbo (CDB) is an antidepressant traditional Chinese medicine (TCM) prescription simplified by Xiaoyaosan (a classic antidepressant TCM prescription) through dismantling research, which has the effect of dispersing stagnated liver qi and nourishing blood in TCM theory. Although the antidepressant effect of CBD has been confirmed in animal studies, the material basis and possible molecular mechanism for antidepressant activity in CBD have not been clearly elucidated. Herein, we investigated the effects and potential mechanisms of CDB antidepressant fraction (petroleum ether fraction of CDB, PEFC) on chronic unpredictable mild stress (CUMS)-induced depression-like behavior in mice using network pharmacology and metabolomics. First, a UPLC-QE/MS was employed to identify the components of PEFC. To extract active ingredients, SwissADME screening was used to the real PEFC components that were found. Potential PEFC antidepressant targets were predicted based on a network pharmacology approach, and a pathway enrichment analysis was performed for the predicted targets. Afterward, a CUMS mouse depression model was established and LC-MS-based untargeted hippocampal metabolomics was performed to identify differential metabolites, and related metabolic pathways. Finally, the protein expressions in mouse hippocampi were determined by Western blot to validate the network pharmacology and metabolomics deduction. A total of 16 active compounds were screened in SwissADME that acted on 73 core targets of depression, including STAT3, MAPKs, and NR3C1; KEGG enrichment analysis showed that PEFC modulated signaling pathways such as PI3K-Akt signaling pathway, endocrine resistance, and MAPK to exert antidepressant effects. PEFC significantly reversed abnormalities of hippocampus metabolites in CUMS mice, mainly affecting the synthesis and metabolism of glycine, serine, and threonine, impacting catecholamine transfer and cholinergic synapses and regulating the activity of the mTOR signaling pathway. Furthermore, Western blot analysis confirmed that PEFC significantly influenced the main protein levels of the PI3K/Akt/mTOR signaling pathways in the hippocampus of mice subjected to CUMS. This study integrated metabolomics, network pharmacology and biological verification to explore the potential mechanism of PEFC in treating depression, which is related to the regulation of amino acid metabolism dysfunction and the activation of PI3K/Akt/mTOR signaling pathways in the hippocampus. The comprehensive strategy also provided a reasonable way for unveiling the pharmacodynamic mechanisms of multi-components, multi-targets, and multi-pathways in TCM with antidepressant effect.

The Power of Psychobiotics in Depression: A Modern Approach through the Microbiota-Gut-Brain Axis: A Literature Review

The microbiota-gut-brain (MGB) axis is a complex communication network linking the gut, microbiota, and brain, influencing various aspects of health and disease. Dysbiosis, a disturbance in the gut microbiome equilibrium, can significantly impact the MGB axis, leading to alterations in microbial composition and function. Emerging evidence highlights the connection between microbiota alterations and neurological and psychiatric disorders, including depression. This review explores the potential of psychobiotics in managing depressive disorders, emphasizing their role in restoring microbial balance and influencing the MGB axis. Psychobiotics exhibit positive effects on the intestinal barrier, immune response, cortisol levels, and the hypothalamic-pituitary-adrenal (HPA) axis. Studies suggest that probiotics may serve as an adjunct therapy for depression, especially in treatment-resistant cases. This review discusses key findings from studies on psychobiotics interventions, emphasizing their impact on the gut-brain axis and mental health. The increasing acceptance of the expanded concept of the MGB axis underscores the importance of microorganisms in mental well-being. As our understanding of the microbiome's role in health and disease grows, probiotics emerge as promising agents for addressing mental health issues, providing new avenues for therapeutic interventions in depressive disorders.

Gut dysbiosis induces the development of depression-like behavior through abnormal synapse pruning in microglia-mediated by complement C3

BACKGROUND

Remodeling eubiosis of the gut microenvironment may contribute to preventing the occurrence and development of depression. Mounting experimental evidence has shown that complement C3 signaling is associated with the pathogenesis of depression, and disruption of the gut microbiota may be an underlying cause of complement system activation. However, the mechanism by which complement C3 participates in gut-brain crosstalk in the pathogenesis of depression remains unknown.

RESULTS

In the present study, we found that chronic unpredictable mild stress (CUMS)-induced mice exhibited obvious depression-like behavior as well as cognitive impairment, which was associated with significant gut dysbiosis, especially enrichment of Proteobacteria and elevation of microbiota-derived lipopolysaccharides (LPS). In addition, peripheral and central complement C3 activation and central C3/CR3-mediated aberrant synaptic pruning in microglia have also been observed. Transplantation of gut microbiota from CUMS-induced depression model mice into specific pathogen-free and germ-free mice induced depression-like behavior and concomitant cognitive impairment in the recipient mice, accompanied by increased activation of the complement C3/CR3 pathway in the prefrontal cortex and abnormalities in microglia-mediated synaptic pruning. Conversely, antidepressants and fecal microbiota transplantation from antidepressant-treated donors improved depression-like behaviors and restored gut microbiome disturbances in depressed mice. Concurrently, inhibition of the complement C3/CR3 pathway, amelioration of abnormal microglia-mediated synaptic pruning, and increased expression of the synapsin and postsynaptic density protein 95 were observed. Collectively, our results revealed that gut dysbiosis induces the development of depression-like behaviors through abnormal synapse pruning in microglia-mediated by complement C3, and the inhibition of abnormal synaptic pruning is the key to targeting microbes to treat depression.

CONCLUSIONS

Our findings provide novel insights into the involvement of complement C3/CR3 signaling and aberrant synaptic pruning of chemotactic microglia in gut-brain crosstalk in the pathogenesis of depression. Video Abstract.

A review of the pharmacological action and mechanism of natural plant polysaccharides in depression

Depression is a prevalent mental disorder. However, clinical treatment options primarily based on chemical drugs have demonstrated varying degrees of adverse reactions and drug resistance, including somnolence, nausea, and cognitive impairment. Therefore, the development of novel antidepressant medications that effectively reduce suffering and side effects has become a prominent area of research. Polysaccharides are bioactive compounds extracted from natural plants that possess diverse pharmacological activities and medicinal values. It has been discovered that polysaccharides can effectively mitigate depression symptoms. This paper provides an overview of the pharmacological action and mechanisms, intervention approaches, and experimental models regarding the antidepressant effects of polysaccharides derived from various natural sources. Additionally, we summarize the roles and potential mechanisms through which these polysaccharides prevent depression by regulating neurotransmitters, HPA axis, neurotrophic factors, neuroinflammation, oxidative stress, tryptophan metabolism, and gut microbiota. Natural plant polysaccharides hold promise as adjunctive antidepressants for prevention, reduction, and treatment of depression by exerting their therapeutic effects through multiple pathways and targets. Therefore, this review aims to provide scientific evidence for developing polysaccharide resources as effective antidepressant drugs.

Xiaoyaosan ameliorates CUMS-induced depressive-like and anorexia behaviors in mice via necroptosis related cellular senescence in hypothalamus

ETHNOPHARMACOLOGICAL RELEVANCE

Depression and anorexia often co-occur and share symptoms such as low mood, lack of energy, and weight loss. Xiaoyaosan is a classic formula comprising of a combination of eight herbs, possessing definitive therapeutic effects, minimal side effects, and economical benefits. It has been extensively employed in clinical treatment of ailments and symptoms such as depression, anxiety, and appetite problems. Nonetheless, its exact pharmacological mechanism with necroptosis remains incompletely explicit.

AIM OF THE STUDY

The aim of this study is to explore the potential mechanisms of anti-depressive and appetite-regulating effects of the active ingredients in Xiaoyaosan, and to investigate whether there is a correlation with necroptosis.

MATERIALS AND METHODS

The network pharmacology method was conducted to identify active ingredients, which were used to predict the possible targets of Xiaoyaosan and explore the potential targets in treating depression and anorexia by overlapping with differentially expressed genes (DEGs) screened from GEO datasets (GSE125441, GSE198597, and GSE69151). Afterwards, the protein-protein interaction (PPI) network, enrichment analyses, hub gene identification, co-expression study and molecular docking were used to study the potential mechanism of Xiaoyaosan. Then, a mice model of depression was established by chronic unpredictable mild stress (CUMS) and the incidence of necroptosis in the hypothalamus of CUMS mice was investigated, while verifying the key therapeutic target of Xiaoyaosan.

RESULTS

Through network pharmacology research, it had been discovered that the 145 active ingredients of the 8 herbs in the Xiaoyaosan could regulate 198 disease targets. Through PPI network analysis and functional enrichment analysis, it had been found that the pharmacological mechanism of Xiaoyaosan mainly involved biological processes such as oxidative stress, kinase activity, and DNA metabolism. It is related to various pathways such as cellular senescence, immune inflammation, and the cell cycle, and 9 hub targets had been identified. Further analysis of the 9 hub targets and the key PPI network clusters clarified the key mechanisms by which Xiaoyaosan exerts anti-depressant and appetite regulating effects, possibly related to necroptosis-mediated cellular senescence. Molecular docking of the key indicators of cellular senescence screened by bioinformatics, SIRT1, ABL1, and MYC, revealed that the key component regulating SIRT1 is 2-[3,4-dihydroxyphenyl]-5,7-dihydroxy-6-[3-methylbut-2-enyl]chromone in licorice root, Glabridin in licorice root regulates ABL1, and β-sitosterol found in Chinese angelica, debark peony root, and fresh ginger regulates MYC. Finally, through in vivo experiments, the expression of necroptosis in the hypothalamus of CUMS mice was verified. The regulatory effects of Xiaoyaosan on key substances RIPK1, RIPK3, MLKL, and p-MLKL were determined, while regulating effects on SIRT1, ABL1, and MYC were also observed.

CONCLUSION

The present study have revealed the common mechanism of Xiaoyaosan in treating depression and anorexia, indicating that the active ingredients of Xiaoyaosan may alleviate the symptoms of depression and anorexia by intervening in the pathways related to necroptosis and cellular senescence. The hub genes and common pathways identified by the study also provide new insights into the therapeutic targets of depression and anorexia, as well as the exploration of pharmacological mechanism of Xiaoyaosan.

Adult hippocampal neurogenesis: pharmacological mechanisms of antidepressant active ingredients in traditional Chinese medicine

Depression is characterized by prominent indicators and manifestations, such as anhedonia, which refers to the inability to experience pleasure, and persistent feelings of hopelessness. In clinical practice, the primary treatment approach involves the utilization of selective serotonin reuptake inhibitors (SSRIs) and related pharmacological interventions. Nevertheless, it is crucial to recognize that these agents are associated with significant adverse effects. Traditional Chinese medicine (TCM) adopts a multifaceted approach, targeting diverse components, multiple targets, and various channels of action. TCM has potential antidepressant effects. Anomalies in adult hippocampal neurogenesis (AHN) constitute a pivotal factor in the pathology of depression, with the regulation of AHN emerging as a potential key measure to intervene in the pathogenesis and progression of this condition. This comprehensive review presented an overview of the pharmacological mechanisms underlying the antidepressant effects of active ingredients found in TCM. Through examination of recent studies, we explored how these ingredients modulated AHN. Furthermore, we critically assessed the current limitations of research in this domain and proposed novel strategies for preclinical investigation and clinical applications in the treatment of depression in future.

Antidepressant pharmacological mechanisms: focusing on the regulation of autophagy

The core symptoms of depression are anhedonia and persistent hopelessness. Selective serotonin reuptake inhibitors (SSRIs) and their related medications are commonly used for clinical treatment, despite their significant adverse effects. Traditional Chinese medicine with its multiple targets, channels, and compounds, exhibit immense potential in treating depression. Autophagy, a vital process in depression pathology, has emerged as a promising target for intervention. This review summarized the pharmacological mechanisms of antidepressants by regulating autophagy. We presented insights from recent studies, discussed current research limitations, and proposed new strategies for basic research and their clinical application in depression.

Zuojin pill improves chronic unpredictable stress-induced depression-like behavior and gastrointestinal dysfunction in mice via the theTPH2/5-HT pathway

BACKGROUND

The complex bidirectional communication between the gastrointestinal tract and the brain is associated with mental disorders such as depression; serotonin, as a crucial neurotransmitter in the communication system between the central nervous system and the gastrointestinal tract, has effects on regulating gastrointestinal motility and sensation and improving psychosomatic status. Zuojin pill is used as a traditional Chinese medicine formula for the treatment of gastrointestinal disorders. This study explored the effects of Zuojin pill on the improvement of depression and gastrointestinal function in CUMS mice via TPH2 and its mechanism.

PURPOSE

The aim of this study was to investigate whether Zuojin pill could improve depression and concomitant gastrointestinal dysfunction, and to reveal whether Zuojin pill could work through the regulation of the tryptophan hydroxylase 2 (TPH2) pathway.

METHODS

The CUMS model was established to observe the effects of Zuojin pill on depression-like behavior and gastrointestinal function in mice. Nissler staining and HE staining were used to observe the structure of hippocampal neurons and intestinal mucosa respectively. 5-HT levels in serum, hippocampus, and intestinal tissues were measured by ELISA, and TPH2 expression in hippocampus and intestinal nerves was observed by WB and immunofluorescence. In order to investigate the protective effect and mechanism of Zuojin pill on PC12 cells, CORT used an in vitro model to produce PC12 cell damage.

RESULTS

Our study showed that Zuojin pill ameliorated depression-like behavior and gastrointestinal dysfunction in CUMS mice, elevated BDNF, 5-HT, and TPH2 expression in the hippocampus, and restored the ratio of dopaminergic and GABAergic neurons between intestinal muscles. In vitro experiments showed that Zuojin pill exerted a protective effect on neurons by regulating TPH2 ubiquitination and thus inhibiting CORT-induced apoptosis of PC12 cells.

CONCLUSION

Zuojin pill improves chronic unpredictable stress-induced depression-like behavior and gastrointestinal dysfunction in mice via the TPH2/5-HT pathway. Therefore, TPH2 may be a potential therapeutic target for depression with gastrointestinal dysfunction.

Targeting the gut-microbiota-brain axis in irritable bowel disease to improve cognitive function - recent knowledge and emerging therapeutic opportunities

The brain-gut axis forms a bidirectional communication system between the gastrointestinal (GI) tract and cognitive brain areas. Disturbances to this system in disease states such as inflammatory bowel disease have consequences for neuronal activity and subsequent cognitive function. The gut-microbiota-brain axis refers to the communication between gut-resident bacteria and the brain. This circuits exists to detect gut microorganisms and relay information to specific areas of the central nervous system (CNS) that in turn, regulate gut physiology. Changes in both the stability and diversity of the gut microbiota have been implicated in several neuronal disorders, including depression, autism spectrum disorder Parkinson's disease, Alzheimer's disease and multiple sclerosis. Correcting this imbalance with medicinal herbs, the metabolic products of dysregulated bacteria and probiotics have shown hope for the treatment of these neuronal disorders. In this review, we focus on recent advances in our understanding of the intricate connections between the gut-microbiota and the brain. We discuss the contribution of gut microbiota to neuronal disorders and the tangible links between diseases of the GI tract with cognitive function and behaviour. In this regard, we focus on irritable bowel syndrome (IBS) given its strong links to brain function and anxiety disorders. This adds to the growing body of evidence supporting targeted therapeutic strategies to modulate the gut microbiota for the treatment of brain/mental-health-related disease.

Effect of Probiotic Therapy on Neuropsychiatric Manifestations in Children with Multiple Neurotransmitter Disorders: A Study

Probiotics, also known as psychobiotics, have been linked to cognitive functions, memory, learning, and behavior, in addition to their positive effects on the digestive tract. The purpose of this study is to examine the psychoemotional effects and cognitive functioning in children with gastrointestinal disorders who undergo psychobiotherapy. A total of 135 participants, aged 5-18 years, were divided into three groups based on the pediatrician's diagnosis: Group I (Control) consisted of 37 patients (27.4%), Group II included 65 patients (48.1%) with psychoanxiety disorders, and Group III comprised 33 individuals (24.4%) with psychiatric disorders. The study monitored neurotransmitter levels such as serotonin, GABA, glutamate, cortisol, and DHEA, as well as neuropsychiatric symptoms including headaches, fatigue, mood swings, hyperactivity, aggressiveness, sleep disorders, and lack of concentration in patients who had gastrointestinal issues such as constipation, diarrhea, and other gastrointestinal problems. The results indicate that psychobiotics have a significant impact on reducing hyperactivity and aggression, and improving concentration. While further extensive studies are needed, these findings offer promising insights into the complexity of a child's neuropsychic behavior and the potential for balancing certain behaviors through psychobiotics.

Unlocking the Secrets: Exploring the Biochemical Correlates of Suicidal Thoughts and Behaviors in Adults with Autism Spectrum Conditions

Involving 1 million people a year, suicide represents one of the major topics of psychiatric research. Despite the focus in recent years on neurobiological underpinnings, understanding and predicting suicide remains a challenge. Many sociodemographical risk factors and prognostic markers have been proposed but they have poor predictive accuracy. Biomarkers can provide essential information acting as predictive indicators, providing proof of treatment response and proposing potential targets while offering more assurance than psychological measures. In this framework, the aim of this study is to open the way in this field and evaluate the correlation between blood levels of serotonin, brain derived neurotrophic factor, tryptophan and its metabolites, IL-6 and homocysteine levels and suicidality. Blood samples were taken from 24 adults with autism, their first-degree relatives, and 24 controls. Biochemical parameters were measured with enzyme-linked immunosorbent assays. Suicidality was measured through selected items of the MOODS-SR. Here we confirm the link between suicidality and autism and provide more evidence regarding the association of suicidality with increased homocysteine (0.278) and IL-6 (0.487) levels and decreased tryptophan (-0.132) and kynurenic acid (-0.253) ones. Our results suggest a possible transnosographic association between these biochemical parameters and increased suicide risk.

The Brain-Gut-Microbiota Interplay in Depression: a key to design innovative therapeutic approaches

Depression is the most prevalent mental disorder in the world associated with huge socio-economic consequences. While depressive-related symptoms are well known, the molecular mechanisms underlying disease pathophysiology and progression remain largely unknown. The gut microbiota (GM) is emerging as a key regulator of the central nervous system homeostasis by exerting fundamental immune and metabolic functions. In turn, the brain influences the intestinal microbial composition through neuroendocrine signals, within the so-called gut microbiota-brain axis. The balance of this bidirectional crosstalk is important to ensure neurogenesis, preserve the integrity of the blood-brain barrier and avoid neuroinflammation. Conversely, dysbiosis and gut permeability negatively affect brain development, behavior, and cognition. Furthermore, although not fully defined yet, changes in the GM composition in depressed patients are reported to influence the pharmacokinetics of common antidepressants by affecting their absorption, metabolism, and activity. Similarly, neuropsychiatric drugs may shape in turn the GM with an impact on the efficacy and toxicity of the pharmacological intervention itself. Consequently, strategies aimed at re-establishing the correct homeostatic gut balance (i.e., prebiotics, probiotics, fecal microbiota transplantation, and dietary interventions) represent an innovative approach to improve the pharmacotherapy of depression. Among these, probiotics and the Mediterranean diet, alone or in combination with the standard of care, hold promise for clinical application. Therefore, the disclosure of the intricate network between GM and depression will give precious insights for innovative diagnostic and therapeutic approaches towards depression, with profound implications for drug development and clinical practice.