Antidepressant effects of a polysaccharide from okra (Abelmoschus esculentus (L) Moench) by anti-inflammation and rebalancing the gut microbiota

Okra extract alleviates lipopolysaccharide-induced inflammation response through the regulation of bile acids, the receptor-mediated pathway, and gut microbiota

BACKGROUND

Okra contains flavonoids and vitamin C as antioxidants and it contains polysaccharides as immunomodulators. Flavonoids regulate the inflammatory response in mice and may be related to gut microbiota. This study therefore aimed to investigate the impact of okra extract (OE) on inflammation in mice and to elucidate its underlying mechanism.

METHOD

Forty male Kunming (KM) mice were categorized into four groups: the control (CON) group, the lipopolysaccharide stimulation (LPS) group, the 5 mg mL-1 OE intervention (LPS + OE) group, and the 5 mg mL-1 OE supplementation plus mixed antibiotics (LPS + OE + ABX) group.

RESULTS

The results showed that, compared with the OE group, the expression of inflammatory signaling pathway genes was upregulated and gut barrier genes were inhibited in the OE + ABX group. The Fxr receptor was activated and the abundance of Akkermansia was increased after OE supplementation, whereas the effect was reversed in the OE + ABX group. Meanwhile, Fxr was correlated positively with Akkermansia.

CONCLUSION

The OE supplementation alleviated the inflammatory response in mice under LPS stimulation, accompanied by changes in gut microbiota and bile acid receptors, whereas the addition of antibiotics caused a disturbance to the gut microbiota in the OE group, thus reducing the effect of OE in alleviating the inflammatory response. © 2024 Society of Chemical Industry.

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.

Current landscape of fecal microbiota transplantation in treating depression

Depression, projected to be the predominant contributor to the global disease burden, is a complex condition with diverse symptoms including mood disturbances and cognitive impairments. Traditional treatments such as medication and psychotherapy often fall short, prompting the pursuit of alternative interventions. Recent research has highlighted the significant role of gut microbiota in mental health, influencing emotional and neural regulation. Fecal microbiota transplantation (FMT), the infusion of fecal matter from a healthy donor into the gut of a patient, emerges as a promising strategy to ameliorate depressive symptoms by restoring gut microbial balance. The microbial-gut-brain (MGB) axis represents a critical pathway through which to potentially rectify dysbiosis and modulate neuropsychiatric outcomes. Preclinical studies reveal that FMT can enhance neurochemicals and reduce inflammatory markers, thereby alleviating depressive behaviors. Moreover, FMT has shown promise in clinical settings, improving gastrointestinal symptoms and overall quality of life in patients with depression. The review highlights the role of the gut-brain axis in depression and the need for further research to validate the long-term safety and efficacy of FMT, identify specific therapeutic microbial strains, and develop targeted microbial modulation strategies. Advancing our understanding of FMT could revolutionize depression treatment, shifting the paradigm toward microbiome-targeting therapies.

Microbiome and Metabolite Analysis Insight into the Potential of Shrimp Head Hydrolysate to Alleviate Depression-like Behaviour in Growth-Period Mice Exposed to Chronic Stress

Chronic stress (CS) endangers the physical and mental health of adolescents. Therefore, alleviating and preventing such negative health impacts are a top priority. This study explores the effect of feeding shrimp head hydrolysate (SHH) on gut microbiota, short-chain fatty acids (SCFAs), and neurotransmitters in growing C57BL/6 mice subjected to chronic unpredictable mild stress. Mice in the model group and three SHH groups were exposed to CS for 44 days, distilled water and SHH doses of 0.18, 0.45, 0.90 g/kg·BW were given respectively by gavage daily for 30 days from the 15th day. The results showed that SHH can significantly reverse depression-like behaviour, amino acids degradation, α diversity and β diversity, proportion of Firmicutes and Bacteroidota, abundance of genera such as Muribaculaceae, Bacteroides, Prevotellaceae_UCG-001, Parabacteroides and Alistipes, concentration of five short-chain fatty acids (SCFAs), 5-HT and glutamate induced by CS. Muribaculaceae and butyric acid may be a controlled target. This study highlights the potential and broad application of SHH as an active ingredient in food to combat chronic stress damage.

The regulatory effect of polysaccharides on the gut microbiota and their effect on human health: A review

Polysaccharides with low toxicity and high biological activities are a kind of biological macromolecule. Recently, growing studies have confirmed that polysaccharides could improve obesity, diabetes, tumors, inflammatory bowel disease, hyperlipidemia, diarrhea, and liver-related diseases by changing the intestinal micro-environment. Moreover, polysaccharides could promote human health by regulating gut microbiota, enhancing production of short-chain fatty acids (SCFAs), improving intestinal mucosal barrier, regulating lipid metabolism, and activating specific signaling pathways. Notably, the biological activities of polysaccharides are closely related to their molecular weight, monosaccharide composition, glycosidic bond types, and regulation of gut microbiota. The intestinal microbiota can secrete glycoside hydrolases, lyases, and esterases to break down polysaccharides chains and generate monosaccharides, thereby promoting their absorption and utilization. The degradation of polysaccharides can produce SCFAs, further regulating the proportion of gut microbiota and achieving the effect of preventing and treating various diseases. This review aims to summarize the latest studies: 1) effect of polysaccharides structures on intestinal flora; 2) regulatory effect of polysaccharides on gut microbiota; 3) effects of polysaccharides on gut microbe-mediated diseases; 4) regulation of gut microbiota on polysaccharides metabolism. The findings are expected to provide important information for the development of polysaccharides and the treatment of diseases.

Along the microbiota-gut-brain axis: Use of plant polysaccharides to improve mental disorders

With the development of gut microbiota-specific interventions for mental disorders, the interactions between plant polysaccharides and microbiota in the intestinal and their consequent effects are becoming increasingly important. In this review, we discussed the role of plant polysaccharides in improving various mental disorders via the microbiota-gut-brain axis. The chemical and structural characteristics and metabolites of these plant polysaccharides were summarised. Plant polysaccharides and their metabolites have great potential for reshaping gut microbiota profiles through gut microbiota-dependent fermentation. Along the microbiota-gut-brain axis, the consequent pharmacological processes that lead to the elimination of the symptoms of mental disorders include 1) regulation of the central monoamine neurotransmitters, amino acid transmitters and cholinergic signalling system; 2) alleviation of central and peripheral inflammation mainly through the NLRP3/NF-κB-related signalling pathway; 3) inhibition of neuronal apoptosis; and 4) enhancement of antioxidant activities. According to this review, monosaccharide glucose and structure -4-α-Glcp-(1→ are the most potent compositions of the most reported plant polysaccharides. However, the causal structure-activity relationship remains to be extensively explored. Moreover, mechanistic elucidation, safety verification, and additional rigorous human studies are expected to advance plant polysaccharide-based product development targeting the microbiota-gut-brain axis for people with mental disorders.

Lactiplantibacillus plantarum-encapsulated microcapsules prepared from okra polysaccharides improved intestinal microbiota in Alzheimer's disease mice

Background

Okra contains a viscous substance rich in water-soluble material, including fibers, pectin, proteoglycans, gum, and polysaccharides. This study explored the use of okra polysaccharides by microorganisms and their potential to improve microbiota.

Methods

The regulation of microcapsules prepared from okra polysaccharides with or without L. plantarum encapsulation on intestinal microbiota was assessed through 16S metagenomic analysis and short-chain fatty acids (SCFAs) in AppNL-G-F/NL-G-F mice (Alzheimer's disease; AD model).

Results

We found that Lactobacillaceae and Lactobacillus were majorly regulated by microcapsules prepared from okra polysaccharides in AD mice. Similarly, microcapsules prepared from okra polysaccharides with L. plantarum encapsulation markedly elevated the abundance of Lactobacillaceae and Lactobacillus and increased SCFAs in AD mice.

Conclusion

Our results suggest that microcapsules prepared from okra polysaccharides with or without L. plantarum encapsulation may improve intestinal microbiota by elevating Lactobacillus levels in AD mice.

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.

Molecular Mechanism of Polysaccharides Extracted from Chinese Medicine Targeting Gut Microbiota for Promoting Health

The accumulating evidence revealed that gut microbiota plays an important role in pathological process of disease including obesity, type 2 diabetes mellitus, heart failure, and non-alcoholic fatty liver disease. Polysaccharides extracted from Chinese medicine (CM) can not only alleviate pathological status but also promote health by anti-inflammatory, regulating immunity, lowering blood glucose and lipids, anti-cancer, and anti-oxidation. The alterations of gut microbiota composition and metabolism pathways are the potential mechanisms of CM polysaccharides treatment. In addition, they exert functions through gut-organ axis or play an indirect role by synergistic actions with other drugs or components mediated by gut microbiota. This review summarizes the molecular mechanisms of CM polysaccharides interacted with intestinal microbial inhabitants as potential prebiotics for promoting health.

BDNF/CREB signaling pathway contribution in depression pathogenesis: A survey on the non-pharmacological therapeutic opportunities for gut microbiota dysbiosis

Emerging evidence supports the gut microbiota and the brain communication in general health. This axis may affect behavior through modulating neurotransmission, and thereby involve in the pathogenesis and/or progression of different neuropsychiatric disorders such as depression. Brain-derived neurotrophic factor and cAMP response element-binding protein known as CREB/BDNF pathway plays have critical functions in the pathogenesis of depression as the same of mechanisms related to antidepressants. However, the putative causal significance of the CREB/BDNF signaling cascade in the gut-brain axis in depression remains unknown. Also interventions such as probiotics supplementation and exercise can influence microbiome also improve bidirectional communication of gut and brain. In this review we aim to explain the BDNF/CREB signaling pathway and gut microbiota dysfunction and then evaluate the potential role of probiotics, prebiotics, and exercise as a therapeutic target in the gut microbiota dysfunction induced depression. The current narrative review will specifically focus on the impact of exercise and diet on the intestinal microbiota component, as well as the effect that these therapies may have on the microbiota to alleviate depressive symptoms. Finally, we look at how BDNF/CREB signaling pathway may exert distinct effects on depression and gut microbiota dysfunction.

Bacopaside I alleviates depressive-like behaviors by modulating the gut microbiome and host metabolism in CUMS-induced mice

Bacopaside I (BSI) is a natural compound that is difficult to absorb orally but has been shown to have antidepressant effects. The microbiota-gut-brain axis is involved in the development of depression through the peripheral nervous system, endocrine system, and immune system and may be a key factor in the effect of BSI. Therefore, this study aimed to investigate the potential mechanism of BSI in the treatment of depression via the microbiota-gut-brain axis and to validate it in a fecal microbiota transplantation model. The antidepressant effect of BSI was established in CUMS-induced mice using behavioral tests and measurement of changes in hypothalamicpituitaryadrenal (HPA) axis-related hormones. The improvement of stress-induced gut-brain axis damage by BSI was observed by histopathological sections and enzyme-linked immunosorbent assay (ELISA). 16 S rDNA sequencing analysis indicated that BSI could modulate the abundance of gut microbiota and increase the abundance of probiotic bacteria. We also observed an increase in short-chain fatty acids, particularly acetic acid. In addition, BSI could modulate the disruption of lipid metabolism induced by CUMS. Fecal microbiota transplantation further confirmed that disruption of the microbiota-gut-brain axis is closely associated with the development of depression, and that the microbiota regulated by BSI exerts a partial antidepressant effect. In conclusion, BSI exerts antidepressant effects by remodeling gut microbiota, specifically through the Lactobacillus and Streptococcus-acetic acid-neurotrophin signaling pathways. Furthermore, BSI can repair damage to the gut-brain axis, regulate HPA axis dysfunction, and maintain immune homeostasis.

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

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

Suanzaoren decoction improves depressive-like behaviors by regulating the microbiota-gut-brain axis via inhibiting TLR4/NFκB/NLRP3 inflammation signal pathway

Depression is a common but serious sickness which causes a considerable burden on individuals and society. Recently, it has been well established that the occurrence of depression was related to the microbiota-gut-brain axis. The toll-like receptor 4 (TLR4)/ nuclear factor kappa-B kinase (NFκB)/ NOD-like receptor thermal protein domain associated protein 3 (NLRP3) pathway is closely associated with the regulation of microbiota-gut-brain axis. Suanzaoren Decoction (SZRD), which recorded in Jin Gui Yao Lve in Han dynasty, has been used for treating insomnia and depression for a long time. However, the action mechanism of the depression regulation through the TLR4/NFκB/NLRP3 pathway by SZRD was still unclear. In this study, SZRD was firstly performed on a chronic unpredictable mild stress (CUMS) mice model. The results of behavioral tests showed that SZRD treatment could ameliorate the depressive-like behaviors of CUMS mice effectively. According to our previous researches about the components of SZRD in vitro and in vivo, the identification of serum metabolites in depression model rats was further analyzed qualitatively using ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry. 27 prototypes and 44 metabolites were identified. The main types of metabolic reactions are glucuronization, sulfation, and so on. Then, using immunohistochemistry and western blotting to monitor the difference in activation of TLR4/NFκB/NLRP3 signaling pathway in mice brain and colon. The results showed that SZRD treatment could reduce expression levels of related factors. Additionally, the SZRD treatment could also inhibit the histopathological damage in the path morphology of the hippocampus and colon. The results of 16SrRNA demonstrated that SZRD could reduce the dysbiosis of the intestinal flora of depressive mice. The above results provided important information for studying the action mechanism of SZRD in treating depression by regulating microbiota-gut-brain axis via inhibiting TLR4/NFκB/NLRP3 pathway.

Unveiling the neuroprotective potential of dietary polysaccharides: a systematic review

Central nervous system (CNS) disorders present a growing and costly global health challenge, accounting for over 11% of the diseases burden in high-income countries. Despite current treatments, patients often experience persistent symptoms that significantly affect their quality of life. Dietary polysaccharides have garnered attention for their potential as interventions for CNS disorders due to their diverse mechanisms of action, including antioxidant, anti-inflammatory, and neuroprotective effects. Through an analysis of research articles published between January 5, 2013 and August 30, 2023, encompassing the intervention effects of dietary polysaccharides on Alzheimer's disease, Parkinson's disease, depression, anxiety disorders, autism spectrum disorder, epilepsy, and stroke, we have conducted a comprehensive review with the aim of elucidating the role and mechanisms of dietary polysaccharides in various CNS diseases, spanning neurodegenerative, psychiatric, neurodevelopmental disorders, and neurological dysfunctions. At least four categories of mechanistic bases are included in the dietary polysaccharides' intervention against CNS disease, which involves oxidative stress reduction, neuronal production, metabolic regulation, and gut barrier integrity. Notably, the ability of dietary polysaccharides to resist oxidation and modulate gut microbiota not only helps to curb the development of these diseases at an early stage, but also holds promise for the development of novel therapeutic agents for CNS diseases. In conclusion, this comprehensive review strives to advance therapeutic strategies for CNS disorders by elucidating the potential of dietary polysaccharides and advocating interdisciplinary collaboration to propel further research in this realm.

Marasmius androsaceus mitigates depression-exacerbated intestinal radiation injuries through reprogramming hippocampal miRNA expression

INTRODUCTION

Cancer patients commonly experience high levels of psychological stress, which poses significant risks to their well-being. Radiotherapy is a primary treatment modality for cancer; however, it often leads to intestinal injuries in these patients. Nevertheless, the impact of mental stress on radiotherapy-intertwined complications remains unclear.

METHODS

To induce intestinal injury, we employed total abdominal irradiation in our experimental model. We conducted high-throughput sequencing to analyze the expression profile of miRNAs in the hippocampus.

RESULTS

We observed that mice with depression exhibited more severe intestinal injuries following total abdominal irradiation. Remarkably, oral administration of Marasmius androsaceus not only alleviated the depressive phenotype but also mitigated radiation-induced intestinal toxicity. Notably, this radioprotective effect was not observed in mice without depression. Depression disrupted the hippocampal miRNA expression profile in mice subjected to local irradiation of the abdomen, leading to the accumulation of miR-139-5p and miR-184-3p in the hippocampus, serum, and small intestine tissues. However, treatment with Marasmius androsaceus reprogrammed the miRNA expression signature in mice with depression. Furthermore, intravenous injection of antagomirs targeting miR-139-5p and miR-184-3p ameliorated depression, up-regulated Spn expression, reduced radiation enteritis, and improved the integrity of the small intestine in irradiated mice.

CONCLUSION

Our findings demonstrate the efficacy of Marasmius androsaceus, a small mushroom, in alleviating depression-aggravated intestinal toxicity following radiotherapy by reprogramming hippocampal miRNA expression.

Polygonum sibiricum polysaccharides exert the antidepressant-like effects in chronic unpredictable mild stress-induced depressive mice by modulating microbiota-gut-brain axis

Polygonum sibiricum polysaccharides (PSP) are one of the main active components of Polygonatum sibiricum, which is a traditional Chinese medicine with food and drug homologies. Recent studies have revealed the antidepressant-like effects of PSP. However, the precise mechanisms have not been clarified. Therefore, the present study was conducted to explore that whether PSP could exert the antidepressant-like effects via microbiota-gut-brain (MGB) axis in chronic unpredictable mild stress (CUMS)-induced depressive mice by transplantation of fecal microbiota (FMT) from PSP administration mice. FMT markedly reversed the depressive-like behaviors of CUMS-induced mice in the open field, the sucrose preference, the tail suspension, the forced swimming, and the novelty-suppressed feeding tests. FMT significantly increased the levels of 5-hydroxytryptamine and norepinephrine, decreased the levels of the pro-inflammatory cytokines in the hippocampus and reduced the levels of corticosterone, an adrenocorticotropic-hormone, in the serum of CUMS-induced mice. In addition, administration of PSP and FMT significantly increased the expressions of ZO-1 and occludin in the colon and decreased the levels of lipopolysaccharide and interferon-γ in the serum of CUMS-induced mice. Moreover, administration of PSP and FMT regulated the signaling pathways of PI3K/AKT/TLR4/NF-κB and ERK/CREB/BDNF. Taken together, these findings indicated that PSP exerted antidepressant-like effects via the MGB axis.

Alpinia oxyphylla Miq. volatile oil ameliorates depressive behaviors and inhibits neuroinflammation in CUMS-exposed mice by inhibiting the TLR4-medicated MyD88/NF-κB signaling pathway

This study aimed to explore the antidepressant effect and underlying mechanism of the Alpinia oxyphylla Miq. volatile oil (AOVO) in mice exposed to chronic unpredictable mild stress (CUMS). C57BL/6 mice were grouped and administered with different dosages of AOVO (0.25, 0.50, 1.00, or 2.00 mL/kg body weight, i.g.), TAK242 (a TLR4 inhibitor, 0.75 mg/kg body weight, i.p.), or TAK242 (0.75 mg/kg body weight, i.p.) + AOVO (0.50 mL/kg body weight, i.g.) for 21 days. Depression-like symptoms in the mice were then evaluated through their body weight gain (BW), the open field test (OFT), the sucrose preference test (SPT), the novelty-suppressed feeding test (NSFT), and forced swimming test (FST). The concentrations of interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor α (TNF-α), and 5-hydroxytyrptamine (5-HT) in the mice were determined using ELISA kits. Hematoxylin and eosin (HE) dying were performed for histopathological examination. The expression of inflammatory proteins was assessed through western blotting (WB) and immunofluorescence staining. AOVO was found to improve the behavioral indexes of CUMS-exposed mice behavioral and synergize TAK242 to mitigate both their depressive symptoms and neuroinflammation. Moreover, AOVO was found to inhibit the hippocampal damage, decrease inflammatory cytokines (Reduced IL-1β, IL-6, and TNF-α by 19.97 %, 22.87 %, and 24.13 %, respectively), and downregulate the expression of TLR4/MyD88/NF-κB signaling pathway-related proteins in the hippocampus of CUMS-exposed mice (Reduced TLR4, MyD88, and NF-κB by 46.14 %, 42.48 %, and 38.08 %, respectively). These findings demonstrate that AOVO can ameliorate depressive behaviors and mitigate neuroinflammation in the CUMS-exposed mice via suppressing the TLR4-medicated MyD88/NF-κB signaling pathway.

The preventive effect of Glycyrrhiza polysaccharide on lipopolysaccharide-induced acute colitis in mice by modulating gut microbial communities

Acute colitis is characterised by an unpredictable onset and causes intestinal flora imbalance together with microbial migration, which leads to complex parenteral diseases. Dexamethasone, a classic drug, has side effects, so it is necessary to use natural products without side effects to prevent enteritis. Glycyrrhiza polysaccharide (GPS) is an α-d-pyranoid polysaccharide with anti-inflammatory effects; however, its anti-inflammatory mechanism in the colon remains unknown. This study investigated whether GPS reduces the lipopolysaccharide (LPS)-induced inflammatory response in acute colitis. The results revealed that GPS attenuated the upregulation of tumour necrosis factor-α, interleukin (IL)-1β, and IL-6 in the serum and colon tissues and significantly reduced the malondialdehyde content in colon tissues. In addition, the 400 mg/kg GPS group showed higher relative expressions of occludin, claudin-1, and zona occludens-1 in colon tissues and lower concentrations of diamine oxidase, D-lactate, and endotoxin in the serum than the LPS group did, indicating that GPS improved the physical and chemical barrier functions of colon tissues. GPS increased the abundance of beneficial bacteria, such as Lactobacillus, Bacteroides, and Akkermansia, whereas pathogenic bacteria, such as Oscillospira and Ruminococcus were inhibited. Our findings indicate that GPS can effectively prevent LPS-induced acute colitis and exert beneficial effects on the intestinal health.

Gut microbiota decreased inflammation induced by chronic unpredictable mild stress through affecting NLRP3 inflammasome

Dysbiosis of the gut microbiota is associated with the development of depression, but the underlying mechanism remains unclear. The aim of this study was to determine the relationship between microbiota and NLRP3 inflammasome induced by chronic unpredictable mild stress (CUMS). Fecal transplantation (FMT) experiment was conducted to elucidate the potential mechanism. Levels of NLRP3 inflammasome, microbiota, inflammatory factors and tight junction proteins were measured. CUMS stimulation significantly increased the levels of NLRP3, Caspase-1 and ASC in brain and colon(p<0.05), decreased the levels of tight junction proteins Occludin and ZO-1 (p<0.05). Interestingly, increased NLRP3 inflammasome and inflammatory cytokines and decreased tight junction proteins were found in antibiotic-treated (Abx) rats received CUMS rat fecal microbiota transplantation. Furthermore, fecal microbiota transplantation altered the microbiota in Abx rats, which partially overlapped with that of the donor rats. Importantly, probiotic administration amended the alteration of microbiota induced by CUMS treatment, then reduced the levels of NLRP3 inflammasome and inflammatory factors. In conclusion, these findings suggested that depression-like behaviors induced by CUMS stimulation were related to altered gut microbiota, broke the intestinal barrier, promoted the expression of NLRP3 inflammasome and elevated inflammation. Therefore, improving the composition of microbiota via probiotic can attenuate inflammation by amending the microbiota and suppressing the activation of NLRP3 inflammasome, which is considered as a novel therapeutic strategy for depression.

Kaixin Jieyu Granule attenuates neuroinflammation-induced depressive-like behavior through TLR4/PI3K/AKT/FOXO1 pathway: a study of network pharmacology and experimental validation

BACKGROUND

Kaixin Jieyu Granule (KJG), an improved formula of Kai-xin-san and Si-ni-san, is a highly effective formula with demonstrated efficacy in preventing depression in previous studies. However, the underlying molecular mechanisms of KJG's antidepressant effects on inflammatory molecules remain unclear. This study aimed to explore the therapeutic effects of KJG on depression using network pharmacology and experimental validation.

METHODS

We employed a multi-faceted approach, combining high-performance liquid chromatography (HPLC), network pharmacology, and molecular docking, to unravel the underlying mechanisms of KJG's anti-depressant effects. To confirm our findings, we conducted at least two independent in vivo experiments on mice, utilizing both the chronic unpredictable mild stress (CUMS)-induced and lipopolysaccharide (LPS)-induced models. Furthermore, the results of in vivo experiments were verified by in vitro assays. Behavioral tests were utilized to evaluate depression-like behaviors, while Nissl staining was used to assess morphological changes in the hippocampus. Pro-inflammatory cytokines and pathway-related protein expressions were determined using a combination of immunofluorescence staining, enzyme-linked immunosorbent assay (ELISA), and Western Blotting (WB).

RESULTS

Our network-based approaches indicated that ginsenoside Rg1 (GRg1) and saikosaponin d (Ssd) are the major constituents of KJG that exert an anti-depressant effect by regulating TLR4, PI3K, AKT1, and FOXO1 targets through the toll-like receptor, PI3K/AKT, and FoxO pathways. In vivo, KJG can attenuate depression-like behaviors, protect hippocampal neuronal cells, and reduce the production of pro-inflammatory mediators (TNF-α, IL-6, and IL-1β) by repressing TLR4 expression, which was regulated by the inhibition of FOXO1 through nuclear exportation. Furthermore, KJG increases the expression levels of PI3K, AKT, p-PI3K, p-AKT, and p-PTEN. Our in vitro assays are consistent with our in vivo studies. On the other hand, the above effects can be reversed by applying TAK242 and LY294002.

CONCLUSION

Our findings suggest that KJG can exert anti-depressant effects by regulating neuroinflammation through the PI3K/AKT/FOXO1 pathway by suppressing TLR4 activation. The study's findings reveal novel mechanisms underlying the anti-depressant effects of KJG, presenting promising avenues for the development of targeted therapeutic approaches for depression.

Eucommiae cortex polysaccharides attenuate gut microbiota dysbiosis and neuroinflammation in mice exposed to chronic unpredictable mild stress: Beneficial in ameliorating depressive-like behaviors

BACKGROUND

Chronic stress alters gut microbiota composition, as well as induces inflammatory responses and behavioral deficits. Eucommiae cortex polysaccharides (EPs) have been reported to remodel gut microbiota and ameliorate obesogenic diet-induced systemic low-grade inflammation, but their role in stress-induced behavioral and physiological changes is poorly understood.

METHODS

Male Institute of Cancer Research (ICR) mice were exposed to chronic unpredictable stress (CUMS) for 4 weeks and then supplemented with EPs at a dose of 400 mg/kg once per day for 2 weeks. Behavioral test-specific antidepressant and anxiolytic effects of EPs were assessed in FST, TST, EPM, and OFT. Microbiota composition and inflammation were detected using 16S ribosomal RNA (rRNA) gene sequencing, quantitative RT-PCR, western blot, and immunofluorescence.

RESULTS

We found that EPs ameliorated gut dysbiosis caused by CUMS, as evidenced by increasing the abundance of Lactobacillaceae and suppressing the expansion of the Proteobacteria, thereby mitigating intestinal inflammation and barrier derangement. Importantly, EPs reduced the release of bacterial-derived lipopolysaccharides (LPS, endotoxin) and inhibited the microglia-mediated TLR4/NFκB/MAPK signaling pathway, thereby attenuating the pro-inflammatory response in the hippocampus. These contributed to restoring the rhythm of hippocampal neurogenesis and alleviating behavioral abnormalities in CUMS mice. Correlation analysis showed that the perturbed-gut microbiota was strongly correlated with behavioral abnormalities and neuroinflammation.

LIMITATIONS

This study did not clarify the causal relationship between EPs remodeling the gut microbiota and improved behavior in CUMS mice.

CONCLUSIONS

EPs exert ameliorative effects on CUMS-induced neuroinflammation and depression-like symptoms, which may be strongly related to their beneficial effects on gut microbial composition.

Gut Microbiota in Anxiety and Depression: Unveiling the Relationships and Management Options

The gut microbiota is critical for maintaining human health and the immunological system. Several neuroscientific studies have shown the significance of microbiota in developing brain systems. The gut microbiota and the brain are interconnected in a bidirectional relationship, as research on the microbiome-gut-brain axis shows. Significant evidence links anxiety and depression disorders to the community of microbes that live in the gastrointestinal system. Modified diet, fish and omega-3 fatty acid intake, macro- and micro-nutrient intake, prebiotics, probiotics, synbiotics, postbiotics, fecal microbiota transplantation, and 5-HTP regulation may all be utilized to alter the gut microbiota as a treatment approach. There are few preclinical and clinical research studies on the effectiveness and reliability of various therapeutic approaches for depression and anxiety. This article highlights relevant research on the association of gut microbiota with depression and anxiety and the different therapeutic possibilities of gut microbiota modification.

Gut microbiota: A new target for traditional Chinese medicine in the treatment of depression

ETHNIC PHARMACOLOGICAL RELEVANCE

The causes of depression are complex. Many factors are involved in its pathogenesis, including the individual's biological and social environment. Although numerous studies have reported that the gut microbiota plays a significant role in depression, drugs that regulate the gut microbiota to treat depression have not yet been comprehensively reviewed. At the same time, more and more attention has been paid to the characteristics of traditional Chinese medicine (TCM) in improving depression by regulating gut microbiota. In ancient times, fecal microbiota transplantation was recorded in TCM for the treatment of severe diseases. There are also records in Chinese ancient books about the use of TCM to adjust gut microbiota to treat diseases, which has opened up a unique research field in TCM. Therefore, this article focuses on the pharmacological effects, targets, and mechanisms of TCM in improving depression by mediating the influence of gut microbiota.

AIM OF THIS REVIEW

To summarize the role the gut microbiota plays in depression, highlight potential regulatory targets, and elucidate the anti-depression mechanisms of TCMs through regulation of the gut microbiota.

METHODS

A systematic review of 256 clinical trials and pharmaceutical studies published until June 2022 was conducted in eight electronic databases (Web of Science, PubMed, SciFinder, Research Gate, ScienceDirect, Google Scholar, Scopus, and China Knowledge Infrastructure), according to the implemented PRISMA criteria, using the search terms "traditional Chinese medicine," "depression," and "gut microbiota."

RESULTS

Numerous studies reported the effects of different gut bacteria on depression and that antidepressants work through the gut microbiota. TCM preparations based on compound Chinese medicine, the Chinese Materia Medica, and major bioactive components exerted antidepressant-like effects by improving levels of neurotransmitters, short-chain fatty acids, brain-derived neurotrophic factor, kynurenine, and cytokines via regulation of the gut microbiota.

CONCLUSION

This review summarized the anti-depression effects of TCM on the gut microbiota, providing evidence that TCMs are safe and effective in the treatment of depression and may provide a new therapeutic approach.

A pectic polysaccharide from fresh okra (Abelmoschus esculentus L.) beneficially ameliorates CCl4-induced acute liver injury in mice by antioxidation, inhibition of inflammation and modulation of gut microbiota

Okra [Abelmoschus esculentus (Linn.) Moench], as a well-known medicinal and food plant, has important physiological activities and health benefits, and polysaccharide is its main bioactive component. In this study, a pectic polysaccharide (OPS-50) prepared from fresh okra pods by three-phase partitioning and gradient (NH4)2SO4 precipitation at a saturation of 50% was employed in carbon tetrachloride (CCl4)-caused acute liver damage in mice to evaluate the hepatoprotective potential. Results indicated that OPS-50 was mainly composed of a limited linear homogalacturonan backbone and abundant rhamnogalacturonan-I domains as side chains. OPS-50 exerted positively protective effects on acute liver damage induced by CCl4 in mice through relieving weight reduction and organ damage, ameliorating liver function and dyslipidemia, alleviating oxidative stress, suppressing pro-inflammatory cytokines, modulating gut microbiota, and promoting short-chain fatty acid secretion. Moreover, liver histopathology demonstrated the protective benefit of OPS-50 on CCl4-caused acute liver damage in mice. Therefore, our data suggested that the pectic OPS-50, as a dietary supplement, have great potential in preventing and treating chemical liver damages.

Reviewing the role of gut microbiota in the pathogenesis of depression and exploring new therapeutic options

The relationship between gut microbiota (GM) and mental health is one of the focuses of psychobiology research. In recent years, the microbial-gut-brain axis (MGBA) concept has gradually formed about this bidirectional communication between gut and brain. But how the GM is involved in regulating brain function and how they affect emotional disorders these mechanisms are tenuous and limited to animal research, and often controversial. Therefore, in this review, we attempt to summarize and categorize the latest advances in current research on the mechanisms of GM and depression to provide valid information for future diagnoses and therapy of mental disorders. Finally, we introduced some antidepressant regimens that can help restore gut dysbiosis, including classic antidepressants, Chinese materia medica (CMM), diet, and exogenous strains. These studies provide further insight into GM's role and potential pathways in emotion-related diseases, which holds essential possible clinical outcomes for people with depression or related psychiatric disorders. Future research should focus on clarifying the causal role of GM in disease and developing microbial targets, applying these findings to the prevention and treatment of depression.

Advances in Polygonatum sibiricum polysaccharides: Extraction, purification, structure, biosynthesis, and bioactivity

Polygonatum sibiricum has been used as food and medicine for thousands of years, and P. sibiricum polysaccharides (PSPs) have become the hot research spot due to their various health-promoting functions. Numerous studies have shown that PSPs possess huge potential in the application of functional food and medicine fields. However, the research status and features of the preparation process, molecular structure, and bioactivities of PSPs are unclear. Therefore, this review makes a comprehensive summary and proposes new insights and guidelines for the extraction, purification, structural features, biosynthesis, and multiple bioactivities of PSPs. Notably, it is concluded that PSPs mainly contain several types of polysaccharides, including fructan, pectin, galactomannan, glucomannans, arabinogalactan, and galactan, and multiple bioactivates, including osteogenic activity, anti-obesity, anti-diabetes, anti-depression, antioxidant, antiglycation, and protective effect against neurotoxicity and gut microbiota regulating activity. This review contributes to the structure-function study and resource utilization of P. sibiricum and its polysaccharides in food fields.

Network pharmacological investigation into the mechanism of Kaixinsan powder for the treatment of depression

Kaixinsan powder (KXS), a classic prescription of traditional Chinese Medicine (TCM), is widely used in the treatment of depression, but its mechanism remains unclear. The network pharmacology method was used to constructe the "herb-component-target" network, and elucidated KXS potential mechanisms of action in the treatment of depression. Moreover, molecular docking was applied to valid the important interactions between the ingredients and the target protein. The "herb-component-target" network indicated that the ingredients of Girinimbin, Gomisin B and Asarone, and the protein targets of ESR, AR and NR3C1 mostly contribute to the antidepressant effect of KXS. KEGG pathway analysis highlighted the most significant pathways associated with depression treatment, including neuroactive ligand-receptor interaction pathway, serotonergic synapse pathway, PI3K-Akt signaling pathway and MAPK signaling pathway. Go enrichment analysis indicated that the mechanism of KXS in treating depression was involved in the biological process of GPCR signal transduction, hormone metabolism and nerve cell apoptosis. Moreover, molecular docking results showed that Polygalaxanthone III, Girinimbine and Pachymic acid performed greater binding ability with key antidepressant target 5-HTR. In conclusion, this study preliminarily revealed key active components in KXS, including Gomisin B, Asarone, Ginsenoside Rg1, Polygalaxanthone III and Pachymic acid, could interact with multiple targets (5-HTR, DR, ADRA, AR, ESR, NR3C1) and modulate the activation of multiple pathways (Neuroactive ligand -receptor interaction pathway, serotonergic synapse pathway, PI3K-Akt signaling pathway and MAPK signaling pathway).

Toward a Deeper Understanding of Gut Microbiome in Depression: The Promise of Clinical Applicability

The emergence of the coronavirus disease 2019 pandemic has dramatically increased the global prevalence of depression. Unfortunately, antidepressant drugs benefit only a small minority of patients. Thus, there is an urgent need to develop new interventions. Accumulating evidence supports a causal relationship between gut microbiota dysbiosis and depression. To advance microbiota-based diagnostics and therapeutics of depression, a comprehensive overview of microbial alterations in depression is presented to identify effector microbial biomarkers. This procedure generated 215 bacterial taxa from humans and 312 from animal models. Compared to controls, depression shows significant differences in β-diversity, but no changes in microbial richness and diversity. Additionally, species-specific microbial changes are identified like increased Eggerthella in humans and decreased Acetatifactor in rodent models. Moreover, a disrupted microbiome balance and functional changes, characterized by an enrichment of pro-inflammatory bacteria (e.g., Desulfovibrio and Escherichia/Shigella) and depletion of anti-inflammatory butyrate-producing bacteria (e.g., Bifidobacterium and Faecalibacterium) are consistently shared across species. Confounding effects of geographical region, depression type, and intestinal segments are also investigated. Ultimately, a total of 178 species and subspecies probiotics are identified to alleviate the depressive phenotypes. Current findings provide a foundation for developing microbiota-based diagnostics and therapeutics and advancing microbiota-oriented precision medicine for depression.

Rhinacanthus nasutus and okara polysaccharides attenuate colitis via inhibiting inflammation and modulating the gut microbiota

Plant polysaccharides have prebiotic properties for gut microbiota and immune modulation. This study aimed to investigate the prevention abilities of edible Rhinacanthus nasutus polysaccharide (RNP) and okara polysaccharide (OP) in Sprague-Dawley rats with acetic acid-induced colitis. The characterizations of RNP and OP were analyzed, including Fourier transform infrared, thermogravimetric analysis, differential scanning calorimetry, and monosaccharide composition. The prebiotic properties of RNP and OP were determined in vitro. In addition, the pathological features of colon length and inflammatory cytokine levels in acetic acid-induced colitis were improved by intragastric preadministration of RNP and OP for 3 weeks. There was no nephrotoxicity or hepatotoxicity in rats via histopathological assessment after RNP and OP intake. Moreover, the abundance of short-chain fatty acids-producing bacteria (Lachnospiraceae, Lactobacilli, and Prevotellaceae) were increased after RNP supplementation. In conclusion, intragastric gavage of RNP and OP significantly modulated the gut microbiota and immune response, consequently alleviating the symptoms of colitis. This novel finding provides an alternative strategy and potential application of these two polysaccharides for colitis prevention and treatment.

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

Chaihu-Shugan-San (CSS) is a traditional botanical drug formula often prescribed to treat depression in oriental countries, but its pharmacotherapeutic mechanism remains unknown. It was recently reported that CSS alters the composition of intestinal microflora and related metabolites such as bile acids (BAs). Since the intestinal microflora affects physiological functions of the brain through the gut-microbiota-brain axis, herein we investigated whether CSS altered BA levels, gut microflora, and depression-like symptoms in chronic unpredictable mild stress (CUMS) mice, a well-established mouse model of depression. Furthermore, we determined whether BA manipulation and fecal microbiota transplantation altered CSS antidepressant actions. We found that the BA chelator cholestyramine impaired the antidepressant effects of CSS, which was partially rescued by dietary cholic acid. CSS increased the relative abundance of Parabacteroides distasonis in the colon of CUMS mice, and increased serum levels of various BAs including hyocholic acid (HCA) and 7-ketodeoxycholic acid (7-ketoDCA). Furthermore, gut bacteria transplantation from CSS-treated mice into untreated or cholestyramine-treated CUMS mice restored serum levels of HCA and 7-ketoDCA, alleviating depression-like symptoms. In the hippocampus, CSS-treated mice had decreased expression of genes associated with BA transport (Bsep and Fxr) and increased expression of brain-derived neurotrophic factor and its receptor, TrkB. Overall, CSS increases intestinal P. distasonis abundance, leading to elevated levels of secondary BAs in the circulation and altered expression of hippocampal genes implicated in BA transport and neurotrophic signaling. Our data strongly suggest that the gut microbiota-brain axis contributes to the potent antidepressant action of CSS by modulating BA metabolism.

The modified outer membrane protein Amuc_1100 of Akkermansia muciniphila improves chronic stress-induced anxiety and depression-like behavior in mice

Akkermansia muciniphila is a next-generation probiotic. The interaction between outer membrane protein Amuc_1100 of A. muciniphila and toll-like receptor 2 (TLR2) in intestinal epithelial cells influences the level of intestinal 5-hydroxytryptamine (5-HT). Amuc_1100^Δ80 is a truncated form of Amuc_1100 lacking the first 80 N-terminal amino acids and has a higher affinity for TLR2 than the wild-type protein. Here, we report that Amuc_1100^Δ80 could significantly reduce anxiety and depression-like behavior of mice when they were exposed to chronic unpredictable mild stress (CUMS). The experimental results of the rat insulinoma cell line RIN-14B showed that Amuc_1100^Δ80 also induced a significantly higher upregulation of tryptophan hydroxylase 1 (Tph1), a rate-limiting enzyme of intestinal 5-HT synthesis. The imbalance of the gut microflora could be diminished when CUMS mice were fed with Amuc_1100^Δ80. These results reveal that Amuc_1100^Δ80 could affect the 5-HT level and the downstream 5-HTR1A-CREB-BDNF signal pathway via interacting with TLR2 and by altering the gut microbial composition. In parallel, the downregulation exerted by Amuc_1100^Δ80 on the inflammation and hyperactivated HPA axis was closely related to the improvement of depression-like symptoms in CUMS mice. This study not only provides new insights into the antidepressant effect of A. muciniphila and its outer membrane protein Amuc_1100 but also identifies new potential targets and pathways in the gut for future research and the development of antidepressant drugs.

Intervention Effects of Okra Extract on Brain-Gut Peptides and Intestinal Microorganisms in Sleep Deprivation Rats

Objective

Okra, possessing various bioactive components, is used to treat different diseases. This study sought to estimate the intervention effects of okra extract (OE) on brain-gut peptides (BGPs) and intestinal microorganisms in sleep deprivation (SD) rats.

Methods

SD rat models were established using the modified multiple platform method and then treated with normal saline, diazepam tablets, or different doses of OE. Body weight and average daily water consumption of rats were recorded. Depressive behaviors of rats were assessed by the open field test and sucrose preference test. Serum levels of noradrenaline, melatonin, inflammatory factors (IL-1β/IL-6/TNF-α/IL-4/IL-10), and BGP indexes, including gastrin (GAS), motilin (MTL), 5-hydroxytryptamine (5-HT), cholecystokinin (CCK), and vasoactive intestinal peptide (VIP) were measured by ELISA. Additionally, the DNA relative contents of representative intestinal microorganisms in the collected rat feces were determined using RT-qPCR.

Results

SD decreased body weight and average daily water consumption and induced depressive behaviors as well as stress and inflammatory responses in rats. SD rats exhibited lowered GAS, MTL, 5-HT, and VIP but elevated CCK and showed diminished DNA relative contents of Bacteroidetes and probiotics (Bifidobacteria and Lactobacilli) but increased Clostridium perfringens. OE at different doses ameliorated the depressive behaviors and mitigated the stress and inflammatory responses in SD rats, raised the serum contents of GAS, MTL, 5-HT, and VIP, reduced CCK level, elevated the DNA relative contents of Bacteroidetes and probiotics, but diminished Clostridium perfringens. OE exhibited similar intervention effects to diazepam tablets (positive control).

Conclusion

OE exerts intervention effects on BGPs and intestinal microorganisms in SD rats.

The chemistry and efficacy benefits of polysaccharides from Atractylodes macrocephala Koidz

Atractylodes macrocephala Koidz (AM), traditional Chinese medicine (TCM) with many medicinal values, has a long usage history in China and other oriental countries. The phytochemical investigation revealed the presence of volatile oils, polysaccharides, lactones, flavonoids, and others. The polysaccharides from AM are important medicinal components, mainly composed of glucose (Glc), galactose (Gal), rhamnose (Rha), arabinose (Ara), mannose (Man), galacturonic acid (GalA) and xylose (Xyl). It also showed valuable bioactivities, such as immunomodulatory, antitumour, gastroprotective and intestinal health-promoting, hepatoprotective, hypoglycaemic as well as other activities. At the same time, based on its special structure and pharmacological activity, it can also be used as immune adjuvant, natural plant supplement and vaccine adjuvant. The aim of this review is to summarize and critically analyze up-to-data on the chemical compositions, biological activities and applications of polysaccharide from AM based on scientific literatures in recent years.

Structural characterization and anti-inflammatory activity of a pectin polysaccharide AP2-c from the lignified okra

In this paper, a pectin polysaccharide AP2-c with molecular weight 6.69 × 10⁵  Da was obtained from the lignified okra. The monosaccharide composition analysis indicated that AP2-c consisted of galactose, rhamnose and galacturonic acid in a molar ratio of 2.3: 1.5: 1.5. The structural characterization indicated that the main chain of AP2-c was composed of →2)-α-L-Rhap-(1→ and →4)-α-D-GalAp-(1→. →2)-α-L-Rhap-(1→ was branched at position O-4 and the branched chain consisted of →3,6)-β-D-Galp-(1→, →6)-β-D-Galp-(1→, α-L-Rhap-(1→ and β-D-Galp-(1→. AP2-c could inhibit the mRNA expression levels of TNF-α, IL-1β and iNOS in LPS-induced macrophages with a dose-dependent manner. Furthermore, AP2-c inhibited the phosphorylation of IκB and p65 via NF-κB pathway. The results indicated that AP2-c had obvious anti-inflammatory activity. PRACTICAL APPLICATIONS: When okra seeds were harvested, lignified okra was always abandoned as waste and had not been fully used for exploitation. Nevertheless, it accounted for more than half of the total plant's weight and was abundant in cell wall polysaccharides, which were the main components of okra to perform a variety of biological functions. In the research, the purified pectin polysaccharide AP2-c was obtained from lignified okra and its physicochemical properties, structural features and anti-inflammatory activity were systematically researched. It was detected that AP2-c exhibited anti-inflammatory activity by blocking NF-κB pathway and thus lowering the expression of related inflammatory factors. The results have significant implications for the value-added application of okra and its processing side products can obviously help to promote the anti-inflammatory application of AP2-c and avoid wasting resources.

Characteristics and Mediating Effect of Gut Microbiota With Experience of Childhood Maltreatment in Major Depressive Disorder

Gut microbiota and childhood maltreatment are closely related to depressive symptoms. This study aimed to analyze the characteristics of gut microbiota in major depressive disorder (MDD) patients with childhood maltreatment experience and explore the correlation between gut microbiota, childhood maltreatment, and depressive symptoms. A total of 37 healthy controls (HCs) and 53 patients with MDD were enrolled, including 18 MDD patients without childhood maltreatment experience and 35 MDD patients with childhood maltreatment experience. The Hamilton’s Depression Scale (HAMD-24) and Childhood Trauma Questionnaire-Short Form (CTQ-SF) were used to evaluate their depressive symptoms and childhood maltreatment experience, respectively. The composition of gut microbiota was evaluated using 16S rRNA sequencing. Spearman’s correlation analysis was used to evaluate the correlation between different gut microbiota, depressive symptoms and childhood maltreatment. The mediation analysis was used to evaluate the mediating effect of gut microbiota. In the α-diversity analysis, we found that the Simpson index and Pielou’s Evenness index differed significantly between MDD patients without childhood maltreatment experience and HCs. In the β-diversity analysis, principal coordinate analysis (PCoA) showed significant differences between MDD patients without childhood maltreatment experience, MDD patients with childhood maltreatment experience and HCs. Twenty-seven different bacteria were identified through Linear discriminant analysis effect size (LEfSe) analysis at different levels of classification. The analysis of the correlation showed that Blautia, Bifidobacterium, Bacteroides, Roseburia, and Phascolarctobacterium were significantly correlated with HAMD and CTQ-SF scores. The mediation analysis showed that childhood maltreatment had a significant direct effect on the patients’ depressive symptoms, and Blautia, Bifidobacterium, Roseburia had a significant mediating effect. The findings of this study suggested that MDD patients with childhood maltreatment experience had different gut microbiota, which might have a mediating effect on the influence of childhood maltreatment on depressive symptoms.

The Intervention of Prebiotics on Depression via the Gut-Brain Axis

The imbalance of intestinal microbiota can cause the accumulation of endotoxin in the main circulation system of the human body, which has a great impact on human health. Increased work and life pressure have led to a rise in the number of people falling into depression, which has also reduced their quality of life. The gut–brain axis (GBA) is closely related to the pathological basis of depression, and intestinal microbiota can improve depressive symptoms through GBA. Previous studies have proven that prebiotics can modulate intestinal microbiota and thus participate in human health regulation. We reviewed the regulatory mechanism of intestinal microbiota on depression through GBA, and discussed the effects of prebiotics, including plant polysaccharides and polyphenols on the regulation of intestinal microbiota, providing new clues for the prevention and treatment of depression.

Ischemic stroke and intestinal flora: an insight into brain-gut axis

Stroke is a type of cerebrovascular disease that significantly endangers human health and lowers quality of life. This understandably places a heavy burden on society and families. In recent years, intestinal flora has attracted increasing attention from scholars worldwide, and its association with ischemic stroke is becoming a hot topic of research amongst researchers in field of stroke. After suffering from a stroke, intestinal microbial dysbiosis leads to increased intestinal permeability and activation of the intestinal immune system, which in turn leads to ectopic intestinal bacteria and pro-inflammatory cells that enter brain tissue through the damaged blood-brain barrier. This exacerbates ischemia-reperfusion injury. Interestingly, after a stroke, some metabolites produced by the intestinal flora attenuate ischemia-reperfusion injury by suppressing the post-stroke inflammatory response and promotes the repair of neurological function. Here we elucidate the changes in gut flora after occurrence of a stroke and highlight the immunomodulatory processes of the post-stroke gut flora.

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

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

High-Pressure Technologies for the Recovery of Bioactive Molecules from Agro-Industrial Waste

Large amounts of food waste are produced each year. These residues require appropriate management to reduce their environmental impact and, at the same time, economic loss. However, this waste is still rich in compounds (e.g., colorants, antioxidants, polyphenols, fatty acids, vitamins, and proteins) that can find potential applications in food, pharmaceutical, and cosmetic industries. Conventional extraction techniques suffer some drawbacks when applied to the exploitation of food residues, including large amounts of polluting solvents, increased time of extraction, possible degradation of the active molecules during extraction, low yields, and reduced extraction selectivity. For these reasons, advanced extraction techniques have emerged in order to obtain efficient residue exploitation using more sustainable processes. In particular, performing extraction under high-pressure conditions, such as supercritical fluids and pressurized liquid extraction, offers several advantages for the extraction of bioactive molecules. These include the reduced use of toxic solvents, reduced extraction time, high selectivity, and the possibility of being applied in combination in a cascade of progressive extractions. In this review, an overview of high-pressure extraction techniques related to the recovery of high added value compounds from waste generated in food industries is presented and a critical discussion of the advantages and disadvantages of each process is reported. Furthermore, the possibility of combined multi-stage extractions, as well as economic and environmental aspects, are discussed in order to provide a complete overview of the topic.

Polysaccharide Regulation of Intestinal Flora: A Viable Approach to Maintaining Normal Cognitive Performance and Treating Depression

The intestinal tract of a healthy body is home to a large variety and number of microorganisms that will affect every aspect of the host’s life. In recent years, polysaccharides have been found to be an important factor affecting intestinal flora. Polysaccharides are widely found in nature and play a key role in the life activities of living organisms. In the intestinal tract of living organisms, polysaccharides have many important functions, such as preventing the imbalance of intestinal flora and maintaining the integrity of the intestinal barrier. Moreover, recent studies suggest that gut microbes can influence brain health through the brain-gut axis. Therefore, maintaining brain health through polysaccharide modulation of gut flora deserves further study. In this review, we outline the mechanisms by which polysaccharides maintain normal intestinal flora structure, as well as improving cognitive function in the brain via the brain-gut axis by virtue of the intestinal flora. We also highlight the important role that gut microbes play in the pathogenesis of depression and the potential for treating depression through the use of polysaccharides to modulate the intestinal flora.

Strategies for circadian rhythm disturbances and related psychiatric disorders: A new cue based on plant polysaccharides and intestinal microbiota

Circadian rhythm is essential to human physiological homeostasis and health. The oscillation of host circadian rhythm affects the composition and function of intestinal microbiota, meanwhile, the normal operation of host...

Effects of Okra (Abelmoschus esculentus L.) on inflammatory mediators: A systematic review of preclinical studies

Objective: Present study aimed to systematically review the available investigations about the effects of okra on important inflammatory mediators including C-reactive protein (CRP), interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis...

Combined probiotics attenuate chronic unpredictable mild stress-induced depressive-like and anxiety-like behaviors in rats

Increasing evidence indicated that probiotics can be effective in improving behaviors similar to depression and anxiety disorders. However, the underlying mechanisms remain unclear, as is the effects of single vs. combined probiotics on depression and anxiety. This study aimed to determine whether combined probiotics could attenuate depressive-like and anxiety-like behavior induced by chronic unpredictable mild stress (CUMS) and its potential mechanisms. Rats underwent CUMS treatment and then administered Lactobacillus rhamnosus HN001 (HN001) or Bifidobacterium animalis subsp. lactis HN019 (HN019), alone or in combination. Levels of neurotransmitters, inflammatory factors, and the gut microbiota were measured. HN001 and (or) HN019 treatment improved depressive-like and anxiety-like behavior in rats, including increased moving distance and exploratory behavior (p < 0.05). In addition, altered gut microbiota structure induced by CUMS was amended by HN001 and/or HN019 (p < 0.05). HN001 and/or HN019 intervention also remarkably normalized levels of 5-HT, DA, NE, HVA, DOPAC, HIAA, TNF-α, IL-6, IL-18 and IL-1β in CUMS rats (p < 0.05). Furthermore, the effects of combined probiotics on decreasing inflammation and improved gut microbiota (Chao1 index and ACE index, p < 0.05) were superior to the single probiotics. Moreover, spearman analysis showed a certain correlation between the different microbiota, such as Firmicutes, Bacteroidetes, Verrucomicrobias, Proteobacterias and Actinobacterias, and inflammation and neurotransmitters. These findings suggested that CUMS induced depressive and anxiety-like behaviors can be alleviated by the combination of probiotics, which was possibly associated with the alterations in the gut microbiota composition and increased neurotransmitters and decreased inflammatory factors.

Morus alba L. (Sangzhi) alkaloids (SZ-A) exert anti-inflammatory effects via regulation of MAPK signaling in macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

Morus alba L. (Sangzhi) alkaloids (SZ-A) tablets have been approved by the China National Medical Products Administration for T2DM treatment. Our previous study (Liu et al., 2021) revealed that SZ-A protected against diabetes and inflammation in KKAy mice. However, the mechanism and components in SZ-A exerting anti-inflammatory effects are unclear.

AIM OF THE STUDY

Investigate the effects and molecular mechanisms of SZ-A on inflammation, and identify anti-inflammatory active components in SZ-A.

MATERIALS AND METHODS

The major ingredients in SZ-A were analyzed by HPLC and sulfuric acid - anthrone spectrophotometry. The inhibitory activities of SZ-A on lipopolysaccharide (LPS)-stimulated inflammation were determined in bone marrow-derived macrophage (BMDM) and RAW264.7 cells. The cytokine levels of IL-6 and TNF-α in cell culture supernatant were measured by enzyme-linked immunosorbent assay (ELISA). Gene expression levels of IL-6 and TNF-α were detected by qRT-PCR. The levels of protein phosphorylation of p38 MAPK, ERK, and JNK were analyzed by Western blot.

RESULTS

The main components in SZ-A were found to be 1-deoxynojirimycin (DNJ), 1,4-dideoxy-1,4-imino-D-arabinitol (DAB), fagomine (FAG), polysaccharide (APS), and arginine (ARG). SZ-A reduced the levels of IL-6 and TNF-α secreted by LPS-induced RAW264.7 and BMDM cells. Simultaneously, the mRNA expression levels of IL-6 and TNF-α were all significantly suppressed by SZ-A in a concentration-dependent manner. Furthermore, SZ-A inhibited the phosphorylation of p38 MAPK, ERK, and JNK in BMDM and the activation of ERK and JNK signaling in RAW264.7 cells. We also observed that DNJ, DAB, FAG, and ARG markedly downregulated IL-6 and TNF-α cytokine levels, while APS did not have an obvious effect.

CONCLUSIONS

SZ-A attenuates inflammation at least partly by blocking the activation of p38 MAPK, ERK, and JNK signaling pathways. DNJ, FAG, DAB, and ARG are the main constituents in SZ-A that exert anti-inflammatory effects.