Herbal prescription Chang'an II repairs intestinal mucosal barrier in rats with post-inflammation irritable bowel syndrome

Tong-Xie-Yao-Fang strengthens intestinal feedback control of bile acid synthesis to ameliorate irritable bowel syndrome by enhancing bile salt hydrolase-expressing microbiota

ETHNOPHARMACOLOGICAL RELEVANCE

A herbal formula Tong-Xie-Yao-Fang (TXYF) is traditionally used to treat irritable bowel syndrome (IBS), modern pharmacological evidence supports that the formula efficacy is associated with altered gut microbiota. Yet, the mechanistic role of gut microbiota in the therapy of TXYF remains unclear. We previously clarified that gut microbiota-dysregulated bile acid (BA) metabolism contribute to the pathogenesis of IBS, deriving a hypothesis that microbiota-BA metabolic axis might be a potential target of TXYF.

AIM OF THE STUDY

We aim to investigate a new gut microbiota-mediated mechanism underlying anti-IBS efficacy of TXYF.

MATERIALS AND METHODS

We established an IBS rat model with a combination of stressors, compared the herbal efficacy in models undergone gut bacterial manipulations, also examined BA metabolism-related microbiota, metabolites, genes and proteins by 16S rRNA gene sequencing, targeted metabolomics, qPCR and multiplex immunofluorescence staining.

RESULTS

We observed that TXYF attenuated visceral hyperalgesia and diarrhea in IBS rats but not in those underwent gut bacteria depletion. Transferring gut microbiota from TXYF-treated donors also decreased visceral sensitivity and slightly relief diarrhea-like behaviors in IBS recipient rats. Fecal 16S rRNA gene sequencing revealed that TXYF modulated microbial β-diversity and taxonomic structure of IBS rats, with a significant increase in relative abundance of bile salt hydrolase (BSH)-expressing Bacteroidaceae. qPCR and culturing data validated that TXYF had a promotive effect on the growth and BSH activity of Bacteroides species. TXYF-reshaped microbiota upregulated the expression of intestinal Fgf15, a feedback signal to control BA synthesis in the liver. As a result, the BA synthetic and excretory levels in IBS rats were decreased by TXYF, so as that colonic BA membrane receptor Tgr5 sensing and its mediated Calcitonin gene-related peptide (Cgrp)-positive neuronal response were attenuated.

CONCLUSION

This study poses a new microbiota-driven therapeutic action for TXYF, highlighting the potential of developing new anti-IBS strategies from the herbal formula targeting BSH-expressing gut bacteria.

Selenium deficiency induces irritable bowel syndrome: Analysis of UK Biobank data and experimental studies in mice

Irritable bowel syndrome (IBS) patients exhibit significantly lower levels of serum selenium (Se) compared to healthy controls. This study integrates a prospective cohort analysis and animal experiments to investigate Se deficiency as a potential risk factor for IBS. Using data from the UK Biobank, a longitudinal analysis was conducted to explore the associations between dietary Se intake and the risk of incident IBS. In animal study, C57BL/6 mice were fed diets with normal (0.2 ppm) or low (0.02 ppm) Se levels to assess the impacts of Se deficiency on IBS symptoms. Furthermore, we performed 16 S rRNA sequencing, untargeted colonic fecal metabolomics analysis, and colon transcriptome profiling to uncover the regulatory mechanisms underlying Se deficiency-induced IBS. The analysis of UK Biobank data revealed a significant correlation between low dietary Se levels and an increased incidence of IBS. In the experimental study, a low Se diet induced IBS symptoms, evidenced by elevated abdominal withdrawal reflex scores, colon inflammation, and severe pathological damage to the colon. Additionally, the low Se diet caused disturbances in gut microbiota, characterized by an increase in Faecalibaculum and Helicobacter, and a decrease in Bifidobacterium and Akkermansia. Combined colonic fecal metabolomics and colon transcriptome analysis indicated that Se deficiency might trigger IBS through disruptions in pathways related to "bile excretion", "steroid hormone biosynthesis", "arachidonic acid metabolism", and "drug metabolism-cytochrome P450". These findings underscore the significant adverse effects of Se deficiency on IBS and suggest that Se supplementation should be considered for IBS patients.

Berberine Enhances Intestinal Mucosal Barrier Function by Promoting Vitamin D Receptor Activity

OBJECTIVE

To evaluate if berberine can act on vitamin D receptors (VDR) and thereby regulate the expression of tight junction proteins (TJPs) in irritable bowel syndrame-diarrhea-predominant (IBS-D) rats.

METHODS

The newborn rats were induced into IBS-D rat model via neonatal maternal separation combined with acetic acid chemical stimulation. After modeling, the model was evaluated and rats were divided into the control group and berberine treatment groups (0.85, 1.7 and 3.4 mg/kg, once a day for 2 weeks). The distal colon was obtained and colonic epithelial cells (CECs) were isolated and cultured after IBS-D model evaluation. The vitamin D receptor response element (VDRE) reporter gene was determined in the CECs of IBS-D rats to analyze the effect of berberine on the VDRE promoter. VDR overexpression or silencing technology was used to analyze whether VDR plays a role in promoting intestinal barrier repair, and to determine which region of VDR plays a role in berberine-regulated intestinal TJPs.

RESULTS

The IBS-D rat model was successfully constructed and the symptoms were improved by berberine in a dose-dependent manner (P<0.05). The activity of VDRE promoter was also effectively promoted by berberine (P<0.05). Berberine increased the expression of TJPs in IBS-D CECs (P<0.05). VDR expression was significantly increased after transfection of different domains of VDR when compared to normal control and basic plasmid groups (all P<0.05). RT-qPCR and Western blot results showed that compared with the blank group, expressions of occludin and zonula occludens-1 were significantly higher in VDR containing groups (all P<0.05). Berberine plus pCMV-Myc-VDR-N group exerted the highest expression levels of occludin and zonula occludens-1 (P<0.05).

CONCLUSION

Berberine enhances intestinal mucosal barrier function of IBS-D rats by promoting VDR activity, and the main site of action is the N-terminal region of VDR.

Natural products derived from herbs as promising source for diarrhea predominant-irritable bowel syndrome via gut microbiota-serotonin pathway

OBJECTIVE

Irritable bowel syndrome (IBS) is one of the most common gastrointestinal disorders, with diarrhea predominant IBS (IBS-D) as the most common subtype. Increasing evidence reported that the gut microbiota-mediated serotonin pathway plays a crucial role in the pathogenesis of IBS-D. In this study, potential herbal medicine, plant extracts and its monomers that can be employed as the candidate molecules for IBS-D through gut microbiota-mediated serotonin pathway were reviewed.

KEY FINDINGS

The bacteria indigenous to gut microbiota regulates serotonin pathway, mainly increasing tryptophan hydroxylase (TPH) and decreasing serotonin reuptake transporter (SERT), by activating cyclooxygenase/prostaglandin E2 (COX/PGE2) signaling. It further accelerated gastrointestinal motility and visceral hyperalgesia. Herbal medicine prescription including Tongxie yaofang and Shugan decoction, as well as some monomers of flavonoid and polyphenol compounds can be regarded as the potential agents for IBS-D. The predominate mechanisms were related to regulating serotonin pathway by driving on the specific bacterial abundance (such as Firmicutes and Bacteroidetes). However, there are few reports on which specific bacteria species play a regulatory role in serotonin pathway, and most of these effective agents were only evidenced by preclinical studies. We hope this review will provide some useful directions for the treatment strategy of IBS-D.

Baizhu shaoyao decoction restores the intestinal barrier and brain-gut axis balance to alleviate diarrhea-predominant irritable bowel syndrome via FoxO1/FoxO3a

BACKGROUND

Diarrhea-predominant irritable bowel syndrome (IBS-D) is a common functional gastrointestinal disease. Besides, baizhu shaoyao decoction (BSD) is an effective treatment for IBS-D; however, its mechanism of action remains unclear.

PURPOSE

This study aims to assess the ability of BSD to therapy IBS-D and to elucidate the underlying mechanism.

METHODS

First, comprehensive analyses, including ADME (absorption, distribution, metabolism, excretion) screening, Venn analysis, Gene Ontology (GO) analysis, and network construction, were performed to characterize IBS-D-related pathways and explore the synergistic effects of BSD active compounds. Next, an IBS-D model was constructed using a three-factor superposition method of neonatal maternal separation, chronic immobilization stress stimulation, and Sennae folium aqueous extract lavage. Moreover, the impact of BSD was assessed based on the body weight, fecal water content, and abdominal withdrawal reflex (AWR), and the results of the open field test, sucrose preference test, intestinal permeability assessment, transmission electron microscopy, and TdT-mediated dUTP nick-end labeling (TUNEL) analysis. The factors that regulate the BSD effects on IBS-D were estimated using immunoblotting, quantitative reverse transcription polymerase chain reaction (q-RTPCR), immunohistochemistry, and transcriptome sequencing analyses.

RESULTS

We found that BSD improved depressive behavior, brain-gut peptide levels, and intestinal permeability induced by IBS-D by increasing the abundance of intestinal tight junctions. In addition, BSD reduced secretory immunoglobulin A levels and the number of intestinal mast cells in IBS-D rats. Network pharmacology and transcriptome sequencing analysis further revealed that the forkhead box O (FoxO) signaling pathway contributed to the BSD-induced alleviation of IBS-D, as BSD regulated the protein and mRNA levels of FoxO1, glycogen synthase kinase 3β, and FoxO3a. Importantly, a FoxO1 inhibitor effectively alleviated IBS-D symptoms in rats, whereas a FoxO3a agonist had the opposite effects.

CONCLUSION

These results demonstrate that BSD alleviates depression and intestinal symptoms by regulating brain-gut peptide expression and restoring the intestinal barrier function via the FoxO signaling pathway. Furthermore, our study uses serum pharmacochemistry technology to analyze the in vivo components of TCM formula under effective condition, solving the problem of the discovery of the effective components of TCM to some extent.

Exploring the Mechanisms of Self-made Kuiyu Pingchang Recipe for the Treatment of Ulcerative Colitis and Irritable Bowel Syndrome using a Network Pharmacology-based Approach and Molecular Docking

BACKGROUND

Ulcerative colitis (UC) and irritable bowel syndrome (IBS) are common intestinal diseases. According to the clinical experience and curative effect, the authors formulated Kuiyu Pingchang Decoction (KYPCD) comprised of Paeoniae radix alba, Aurantii Fructus, Herba euphorbiae humifusae, Lasiosphaera seu Calvatia, Angelicae sinensis radix, Panax ginseng C.A. Mey., Platycodon grandiforus and Allium azureum Ledeb.

OBJECTIVE

The aim of the present study was to explore the mechanisms of KYPCD in the treatment of UC and IBS following the Traditional Chinese Medicine (TCM) theory of "Treating different diseases with the same treatment".

METHODS

The chemical ingredients and targets of KYPCD were obtained using the Traditional Chinese Medicine Systems Pharmacology database and analysis platform (TCMSP). The targets of UC and IBS were extracted using the DisGeNET, GeneCards, DrugBANK, OMIM and TTD databases. The "TCM-component-target" network and the "TCM-shared target-disease" network were imaged using Cytoscape software. The protein-protein interaction (PPI) network was built using the STRING database. The DAVID platform was used to analyze the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Using Autodock Tools software, the main active components of KYPCD were molecularly docked with their targets and visualized using PyMOL.

RESULTS

A total of 46 active ingredients of KYPCD corresponding to 243 potential targets, 1,565 targets of UC and 1,062 targets of IBS, and 70 targets among active ingredients and two diseases were screened. Core targets in the PPI network included IL6, TNF, AKT1, IL1B, TP53, EGFR and VEGFA. GO and KEGG enrichment analysis demonstrated 563 biological processes, 48 cellular components, 82 molecular functions and 144 signaling pathways. KEGG enrichment results revealed that the regulated pathways were mainly related to the PI3K-AKT, MAPK, HIF-1 and IL-17 pathways. The results of molecular docking analysis indicated that the core active ingredients of KYPCD had optimal binding activity to their corresponding targets.

CONCLUSION

KYPCD may use IL6, TNF, AKT1, IL1B, TP53, EGFR and VEGFA as the key targets to achieve the treatment of UC and IBS through the PI3K-AKT, MAPK, HIF-1 and IL-17 pathways.

Chlorogenic Acid Ameliorates Post-Infectious Irritable Bowel Syndrome by Regulating Extracellular Vesicles of Gut Microbes

Post-infectious irritable bowel syndrome (PI-IBS) occurs after acute infectious diarrhea, and dysbiosis can be involved in its pathogenesis. Here, the role of chlorogenic acid (CGA) is investigated, a natural compound with several pharmacological properties, in alleviating PI-IBS in rats. It is elucidated that the gut microbiota plays a key role in PI-IBS pathogenesis and that rectal administration of CGA alleviated PI-IBS by modulating the gut microbiota and its metabolites. CGA supplementation significantly increased fecal Bacteroides acidifaciens abundance and glycine levels. Glycine structurally altered B. acidifaciens extracellular vesicles (EVs) and enriched functional proteins in the EVs; glycine-induced EVs alleviated PI-IBS by reducing inflammation and hypersensitivity of the intestinal viscera and maintaining mucosal barrier function. Moreover, B. acidifaciens EVs are enriched in the brain tissue. Thus, CGA mediates the mitigation of PI-IBS through the gut microbiota and its metabolites. This study proposes a novel mechanism of signal exchange between the gut microenvironment and the host.

Bifico relieves irritable bowel syndrome by regulating gut microbiota dysbiosis and inflammatory cytokines

PURPOSE

Gut microbiota dysbiosis, a core pathophysiology of irritable bowel syndrome (IBS), is closely related to immunological and metabolic functions. Gut microbiota-based therapeutics have been recently explored in several studies. Bifico is a probiotic cocktail widely used in gastrointestinal disorders which relate to the imbalance of gut microbiota. However, the efficacy and potential mechanisms of Bifico treatment in IBS remains incompletely understood.

METHODS

Adopting a wrap restraint stress (WRS) -induced IBS mice model. Protective effect of Bifico in IBS mice was examined through abdominal withdrawal reflex (AWR) scores. 16S rDNA, ¹H nuclear magnetic resonance (¹H-NMR) and western blot assays were performed to analyze alterations of gut microbiota, microbiome metabolites and inflammatory cytokines, respectively.

RESULTS

Bifico could decrease intestinal visceral hypersensitivity. Although gut microbiota diversity did not increase, composition of gut microbiota was changed after treatment of Bifico, which were characterized by an increase of Proteobacteria phylum and Actinobacteria phylum, Muribaculum genus, Bifidobacterium genus and a decrease of Parabacteroides genus, Sutterella genus and Lactobacillus genus. Moreover, Bifico elevated the concentration of short-chain fatty acids (SCFAs) and reduced protein levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). From further Spearman's correlation analysis, Bifidobacterium genus were positively correlated with SCFAs including propionate, butyrate, valerate and negatively correlated with IL-6 and TNF-α.

CONCLUSION

Bifico could alleviate symptoms of IBS mice through regulation of the gut microbiota, elevating production of SCFAs and reducing the colonic inflammatory response.

Tong-Xie-Yao-Fang alleviates diarrhea-predominant irritable bowel syndrome in rats via the GCN2/PERK-eIF2α-ATF4 signaling pathway

BACKGROUND

Diarrhea-predominant irritable bowel syndrome (IBS-D) is a common functional gastrointestinal disease. Tong-Xie-Yao-Fang (TXYF), the traditional Chinese herbal medicine prescription, is a classic and effective prescription for the treatment of IBS-D, but its mechanism of action is not fully clarified.

OBJECTIVE

To evaluate the efficacy of TXYF in the treatment of IBS-D and to explore its potential mechanism of action.

METHODS

Changes in the serum levels of 50 free amino acids were targeted for detection by high-performance liquid chromatography (HPLC), and the expression of glucose-regulated protein 78 (GRP78), general control nonderepressible 2 (GCN2), and endoplasmic reticulum-resident kinase (PERK) was detected by immunohistochemistry examinations in healthy volunteers and IBS-D patients. The IBS-D rat was constructed by the three-factor superposition method of neonatal maternal separation, 2,4,6-trinitrobenzene sulfonic acid enema, and chronic unpredictable stress stimulation. The treatment effect of TXYF on IBS-D rats was observed by recording the body weight, grasp force, fecal water content (FWC), and abdominal withdrawal reflex (AWR) of rats before and after treatment. The effects of GCN2/PERK-eukaryotic initiation factor-2 (eIF2α) -activating transcription Factor 4 (ATF4) pathway proteins and gene expression were analyzed by western blotting, reverse transcription-polymerase chain reaction (RT-qPCR), and immunohistochemistry evaluations.

RESULTS

Compared with healthy volunteers, IBS-D patients exhibited lower levels of cysteine, γ-aminoacetic acid (GABA), homoproline, and lysine, and immunohistochemistry showed strong activation of GRP78, a marker of endoplasmic reticulum stress. Differential expression of GCN2 and PERK proteins was detected in IBS-D patients and rat colons. In the IBS-D rats, TXYF improved the body weight and grasp force, reduced the FWC, and improved the AWR score. TXYF increased the levels of p-GCN2 and GCN2 and reduced the levels of GRP78, p-PERK, PERK, p-eIF2α, and eIF2α, thereby affecting the expression of the apoptosis-related transcription factors ATF4, CHOP, Caspase-3, and Bcl-2.

CONCLUSION

Our study showed that TXYF improved IBS-D by inhibiting apoptosis. The anti-apoptosis effects were potentially mediated by regulating the GCN2/PERK-eIF2a-ATF4 signaling pathway.

Paeoniflorin Ameliorates Colonic Fibrosis in Rats with Postinfectious Irritable Bowel Syndrome by Inhibiting the Leptin/LepRb Pathway

Postinfectious irritable bowel syndrome (PI-IBS) is a highly prevalent gastrointestinal disorder associated with immune dysregulation and depression- and anxiety-like behaviors. Through traditional medicine, the active ingredient of Paeoniae Radix called paeoniflorin (PF) was previously found to prevent the symptoms of PI-IBS. However, there is limited information on the effects of PF on intestinal function and depression- and anxiety-like symptoms in PI-IBS animal models. Here, we aimed to determine the effects of PF treatment on the symptoms of PI-IBS in a rat model. The PI-IBS rat model was established via early postnatal sibling deprivation (EPSD), trinitrobenzenesulfonic acid (TNBS), and chronic unpredictable mild stress (CUMS) stimulation and then treated with different dosages of PF (10, 20, and 40 mg/kg) and leptin (1 and 10 mg/kg). The fecal water content and body weight were measured to evaluate the intestinal function, while the two-bottle test for sucrose intake, open field test (OFT), and elevated plus maze test (EMT) were performed to assess behavioral changes. The serum leptin levels were also measured using an enzyme-linked immunosorbent assay. Furthermore, the expressions of leptin and its receptor, LepRb, were detected in colonic mucosal tissues through an immunohistochemical assay. The activation of the PI3K/AKT signaling pathway and the expression of brain-derived neurotrophic factor (BDNF) were also detected via western blotting. After the experimental period, the PI-IBS rats presented decreased body weight and increased fecal water content, which coincided with elevated leptin levels and heightened depression- and anxiety-like behaviors (e.g., low sucrose intake, less frequency in the center areas during OFT, and fewer activities in the open arms during EMT). However, the PF treatment ameliorated these observed symptoms. Furthermore, PF not only inhibited leptin/LepRb expression but also reduced the PI3K/AKT phosphorylation and BDNF expression in PI-IBS rats. Notably, cotreatment with leptin (10 mg/kg) reduced the effects of PF (20 mg/kg) on colonic fibrosis, leptin/LepRb expression, and PI3K/AKT activation. Therefore, our findings suggest that leptin is targeted by PF via the leptin/LepRb pathway, consequently ameliorating the symptoms of PI-IBS. Our study also contributes novel insights for elucidating the pharmacological action of PF on gastrointestinal disorders and may be used for the clinical treatment of PI-IBS in the future.

Quality markers of Baizhu dispensing granules based on multi-component qualitative and quantitative analysis combined with network pharmacology and chemometric analysis

ETHNOPHARMACOLOGICAL RELEVANCE

The dispensing granules of traditional Chinese medicines (TCMs) is an innovative form of medicinal material for TCMs decoction, which is gradually recognized in the clinic due to being suitable for production on a large scale and convenient to take for patients. However, the quality control of TCMs dispensing granules is being challenged, because they contain too many unrevealed hydrophilic components.

AIM OF THE STUDY

Here, the dispensing granules produced from the rhizome of Atractylodes macrocephala (Baizhu dispensing granules), were explored as a case to explore the quality markers correlated to the clinical efficacy of TCMs dispensing granules by a comprehensive strategy of integrating chemical profiling, network pharmacology, and chemometric analysis.

MATERIALS AND METHODS

First, the chemical profiling of Baizhu dispensing granules was characterized by using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS). Subsequently, the potential active components responsible for the efficacy of Baizhu dispensing granules were screened via network pharmacology, and the ultra-performance liquid chromatography coupled with photodiode array detector (UPLC-PDA) method was developed for quantitative analysis of the potential active components in 26 batches of Baizhu dispensing granules. Finally, the quality markers of Baizhu dispensing granules were deciphered based on content variations of potential active components and chemometric analysis.

RESULTS

A total of 69 components were identified from Baizhu dispensing granules. Network pharmacology analysis further revealed that eight of them including five caffeoylquinic acids (31, 32, 36, 42, 44) and three sesquiterpenoids (63, 67, 76) were intimately connected to the core targets of dyspepsia, enteritis, gastritis and immunity. The contents of eight components differed greatly among 26 batches of Baizhu dispensing granules. Chlorogenic acid (31), cryptochlorogenic acid (32) and atractylenolide III (63) have higher concentrations and make great contributions to distinguish different batches of the Baizhu dispensing granules based on principal component analysis (PCA) and orthogonal partial least squares-discriminate analysis (OPLS-DA), and could be used as the quality markers of Baizhu dispensing granules.

CONCLUSIONS

Our study defined the quality markers of Baizhu dispensing granules, which will benefit further investigation on the quality evaluation of TCMs dispensing granules containing Baizhu. The strategy used in this study will be helpful for discovering the quality markers of other TCMs dispensing granules.

Immunometabolism at the service of traditional Chinese medicine

To enhance therapeutic efficacy and reduce adverse effects, ancient practitioners of traditional Chinese medicine (TCM) prescribe combinations of plant species/animal species and minerals designated "TCM formulae" developed based on TCM theory and clinical experience. TCM formulae have been shown to exert curative effects on complex diseases via immune regulation but the underlying mechanisms remain unknown at present. Considerable progress in the field of immunometabolism, referring to alterations in the intracellular metabolism of immune cells that regulate their function, has been made over the past decade. The core context of immunometabolism is regulation of the allocation of metabolic resources supporting host defense and survival, which provides a critical additional dimension and emerging insights into how the immune system and metabolism influence each other during disease progression. This review summarizes research findings on the significant association between the immune function and metabolic remodeling in health and disease as well as the therapeutic modulatory effects of TCM formulae on immunometabolism. Progressive elucidation of the immunometabolic mechanisms involved during the course of TCM treatment continues to aid in the identification of novel potential targets against pathogenicity. In this report, we have provided a comprehensive overview of the benefits of TCM based on regulation of immunometabolism that are potentially applicable for the treatment of modern diseases.

Suppression of PTRF Alleviates Post-Infectious Irritable Bowel Syndrome via Downregulation of the TLR4 Pathway in Rats

Background: Accumulating evidence suggests that the polymerase I and transcript release factor (PTRF), a key component of the caveolae structure on the plasma membrane, plays a pivotal role in suppressing the progression of colorectal cancers. However, the role of PTRF in the development of functional gastrointestinal (GI) disorders remains unclear. Post-infectious irritable bowel syndrome (PI-IBS) is a common functional GI disorder that occurs after an acute GI infection. Here, we focused on the role of PTRF in the occurrence of PI-IBS and investigated the underlying mechanisms. Methods: Lipopolysaccharide (LPS) (5 μg/ml) was used to induce inflammatory injury in human primary colonic epithelial cells (HCoEpiCs). Furthermore, a rat model of PI-IBS was used to study the role of PTRF. Intestinal sensitivity was assessed based on the fecal water content. A two-bottle sucrose intake test was used to evaluate behavioral changes. Furthermore, shRNA-mediated knockdown of PTRF was performed both in vitro and in vivo. We detected the expression of PTRF in colonic mucosal tissues through immunohistochemistry (IHC), western blotting (WB), and immunofluorescence (IF) analysis. Luciferase activity was quantified using a luciferase assay. Co-localization of PTRF and Toll-like receptor 4 (TLR4) was detected using IF analysis. The activation of the signaling pathways downstream of TLR4, including the iNOs, p38, extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK) pathways, was detected via WB. The levels of NO, IL-1β, IL-6, and TNF-α were measured using enzyme-linked immunosorbent assays. Results: LPS significantly induced PTRF expression and signaling downstream of TLR4, including p38, ERK, and JNK pathways, in HCoEpiCs. Moreover, shRNA-mediated knockdown of PTRF in HCoEpiCs significantly decreased the phosphorylation of JNK, ERK, and p38 and iNOS expression. In PI-IBS rats, the lack of PTRF not only reduced fecal water content and suppressed depressive behavior but also increased the body weight. Furthermore, we found a strong co-localization pattern for PTRF and TLR4. Consistently, the lack of PTRF impaired TLR4 signaling, as shown by the decreased levels of p-JNK, p-ERK, and p-p38, which are upstream factors involved in iNOS expression. Conclusion: PTRF promoted PI-IBS and stimulated TLR4 signaling both in vitro and in vivo. The results of this study not only enlighten the pathogenesis of PI-IBS but also help us understand the biological activity of PTRF and provide an important basis for the clinical treatment of PI-IBS by targeting PTRF.

Tong Xie Yao Fang: A Classic Chinese Medicine Prescription with Potential for the Treatment of Ulcerative Colitis

The prescription of Tong Xie Yao Fang (TXYF) was derived from the Yuan dynasty “Dan Brook Heart Law,” which was a representative formula for treating liver-spleen disharmony, diarrhea, and abdominal pain. The prescription is composed of four herbs for soothing the liver and strengthening the spleen. TXYF is reportedly capable of eliminating discomfort in ulcerative colitis (UC). This classic formula has been widely used for regulating gastrointestinal motor dysfunction and repairing colon mucosa. This review aims to provide current information on the pharmacology and clinical research of TXYF in the treatment of UC, and to critically appraise that information, in order to guide the future clinical use and experimental study of TXYF in the treatment of UC. We searched online databases including PubMed, CNKI, and Google Scholar for research published between 2010 and 2020 on TXYF and its efficacy in the treatment of UC. The findings indicated that TXYF has anti-inflammatory and immunomodulatory effects, regulates cell signal transduction, brain-gut axis, and intestinal flora in UC, and may promote targeting of bone mesenchymal stem cells (BMSCs) to the colonic mucosa and accelerate healing of the colonic mucosal barrier. In addition, the results of clinical studies showed that TXYF has good efficacy and few adverse reactions in the treatment of UC. Although it has achieved some success, the research is limited by deficiencies; there is a lack of unified standards for the construction of UC animal models and for administration regimen. In addition, the dosage of TXYF is not consistent and lacks pharmacological verification, and clinical trial data are not detailed or sufficiently rigorous. Therefore, a more rigorous, comprehensive, and in-depth study of TXYF in the treatment of UC is needed.

Adjuvant treatment and molecular mechanism of probiotic compounds in patients with gastric cancer after gastrectomy

Gastrectomy is the main treatment for gastric cancer (GC) at present. Surgery improves the survival rate of patients, but the complications seriously affect the recovery and lack effective treatment measures. In the present study, probiotic compounds (4 strains; Lactobacillus plantarum MH-301 (CGMCC NO. 18618), L. rhamnosus LGG-18 (CGMCC NO. 14007), L. acidophilus and Bifidobacterium animalis subsp.lactis LPL-RH (CGMCC NO. 4599)), through clinical and animal model verification, were studied to try to find the auxiliary treatment measures after gastrectomy, and explore its potential mechanism. Clinical research results showed that probiotic compounds treatment could significantly lower postoperative inflammation, enhance immunity, resume gut microbiota composition and promote postoperative recovery. The results in rat models indicated that gastrostomy led to the aggravation of inflammation, the impairment of immunity and intestinal barrier, and the disorder of gut microbiota in vivo. Furthermore, probiotic compounds' administration could downregulate the inflammatory and permeability signaling pathways in the intestinal tissue, reduce the levels of proinflammatory factors, maintain the intestinal mucosal barrier and immune function, and recover the disorder of gut microbiota after gastrectomy in rats. Therefore, we conclude that probiotic compounds can restore gut microbiota homeostasis, reduce inflammation, maintain intestinal mucosal barrier and immunity, finally promote recovery after gastrectomy, and is expected to improve the prognosis of patients.

Puerarin from Pueraria lobata alleviates the symptoms of irritable bowel syndrome-diarrhea

As a functional bowel disorder, irritable bowel syndrome (IBS), especially IBS-diarrhea (IBS-D), affects approximately 9-20% of the population worldwide. Classical treatments for IBS usually result in some side effects and intestinal microbial disorders, which inhibit the clinical effects. Natural edible medicines with beneficial effects and few side effects have received more attention in recent years. Puerarin is the main active ingredient in pueraria and has been used in China to treat splenasthenic diarrhea and as a natural food in folk medicine for hundreds of years. However, there have been no reports of using puerarin in the treatment of IBS-D, and the underlying mechanism is also still unclear. In this study, a comprehensive model that could reflect the symptoms of IBS-D was established by combining neonatal maternal separation (NMS) and adult colonic acetic acid stimulation (ACAAS) in rats. The results showed that puerarin could reverse the abdominal pain and diarrhea in IBS-D rats. The therapeutic effect was realized by regulating the richness of the gut microbiota to maintain the stabilization of the intestinal micro-ecology. Furthermore, the possible mechanism might be related to the activity of the hypothalamic-pituitary-adrenal (HPA) axis by the suppressed expression of corticotropin-releasing hormone receptor (CRF) 1. At the same time, intestinal function was improved by enhancing the proliferation of colonic epithelial cells by upregulating the expression of p-ERK/ERK and by repairing the colonic mucus barrier by upregulating occludin expression. All these results suggest that puerarin could exert excellent therapeutic effects on IBS-D.

Treatment of Spleen-Deficiency Syndrome With Atractyloside A From Bran-Processed Atractylodes lancea by Protection of the Intestinal Mucosal Barrier

Atractylodes lancea (Thunb.) DC. (AL) is used in traditional Chinese medicine for the treatment of spleen-deficiency syndrome (SDS). Bran-processed Atractylodes lancea (BAL) has been found to be more effective than unprocessed AL. However, the compound in BAL active against SDS remains unclear. The pharmacological efficacy of BAL and its mechanism of action against SDS were investigated by HPLC-ELSD. Candidate compound AA (atractyloside A) in AL and BAL extracts was identified by HPLC-MS analysis. AA was tested in a rat model of SDS in which body weight, gastric residual rate, and intestinal propulsion were measured, and motilin (MTL), gastrin (GAS), and c-Kit were quantified by enzyme-linked immunosorbent assay. Potential targets and associated pathways were identified based on network pharmacology analysis. mRNA expression levels were measured by qRT-PCR and protein expression levels were measured by Western blot analysis and immunohistochemistry. AA increased body weight, intestinal propulsion, MTL, GAS, and c-Kit levels, while decreasing gastric residual volume and intestinal tissue damage, as same as Epidermal Growth Factor Receptor and Proliferating Cell Nuclear Antigen levels. Seventy-one potential pharmacologic targets were identified. Analysis of protein interaction, Gene Ontology (GO) functional analysis, pathway enrichment analysis, and docking and molecular interactions highlighted MAPK signaling as the potential signal transduction pathway. Validation experiments indicated that treatment with AA increased MTL, GAS, ZO-1, and OCLN levels, while reducing AQP1, AQP3, and FGF2 levels. In addition, phosphorylation of p38 and myosin light-chain kinase (MLCK) expression were inhibited. AA improved gastrointestinal function by protecting the intestinal mucosal barrier via inhibition of the p38 MAPK pathway. The results have clinical implications for the therapy of SDS.

Tong-Xie-Yao-Fang improves intestinal permeability in diarrhoea-predominant irritable bowel syndrome rats by inhibiting the NF-κB and notch signalling pathways

BACKGROUND

Tong-Xie-Yao-Fang (TXYF) has been shown to be effective in diarrhoea-predominant irritable bowel syndrome (IBS-D) patients. However, the underlying mechanism remains to be clarified. The aim of this study was to investigate the efficacy and related mechanisms of TXYF in an IBS-D rat model.

METHODS

The IBS-D rat model was established with 4% acetic acid and evaluated by haematoxylin-eosin (HE) staining. Then, IBS-D rats were divided into control, TXYF and rifaximin groups and treated intragastrically with normal saline, TXYF and rifaximin, respectively, for 14 days. The following indicators were measured before and after treatment: defecation frequency, faecal water content (FWC) and colorectal distension (CRD). Histopathological changes in the distal colon were observed after treatment. The expression of OCLN and ZO1 in the distal colon of IBS-D rats reflected the intestinal mucosal permeability, as measured by qRT-PCR, western blot, and enzyme-linked immunosorbent assays (ELISAs). The NF-κB and Notch signalling pathways and inflammation-related factors were investigated.

RESULTS

After treatment with TXYF, the defecation frequency, FWC and CRD were significantly lower than those in the model group (P < 0.05). HE staining showed that colonic epithelial cells (CECs) in the IBS-D rats displayed significant oedema, impaired intestinal mucosal integrity and an increased influx of inflammatory cells. A significant reduction in granulocyte and CEC oedema was observed after the administration of TXYF and rifaximin compared to that of the model group and blank group (P < 0.05). TXYF significantly upregulated the expression of OCLN and ZO-1 and downregulated inflammation-related factors (IL-6, IL-1β, and TNF-α and the chemokine KC) in IBS-D rats compared to those in the model group rats (P < 0.05). In terms of the NF-κB and Notch signalling pathways, the expression of NICD, p-ERK, Hes-1 and p-P65 decreased significantly in the TXYF and rifaximin groups, while the expression of ATOH1 increased significantly compared to that in the model group (P < 0.05).

CONCLUSION

TXYF can effectively improve intestinal permeability and enhance intestinal mucosal barrier function, which may be related to inhibition of the inflammatory cascade and the NF-κB and Notch signalling pathways.

Chang'an II Decoction ( II )-Containing Serum Ameliorates Tumor Necrosis Factor-α-Induced Intestinal Epithelial Barrier Dysfunction via MLCK-MLC Signaling Pathway in Rats

OBJECTIVE

To investigate the effect of Chang'an II Decoction ( II ))-containing serum on intestinal epithelial barrier dysfunction in rats.

METHODS

Tumor necrosis factor (TNF)-α-induced injury of Caco-2 monolayers were established as an inflammatory model of human intestinal epithelium. Caco-2 monolayers were treated with blank serum and Chang'an II Decoction-containing serum that obtained from the rats which were treated with distilled water and Chang'an II Decoction intragastrically at doses of 0.49, 0.98, 1.96 g/(kg·d) for 1 week, respectively. After preparation of containing serum, cells were divided into the normal group, the model group, the Chang'an II-H, M, and L groups (treated with 30 ng/mL TNF-α and medium plus 10% high, middle-, and low-doses Chang'an II serum, respectively). Epithelial barrier function was assessed by transepithelial electrical resistance (TER) and permeability of fluorescein isothiocyanate (FITC)-labeled dextran. Transmission electron microscopy was used to observe the ultrastructure of tight junctions (TJs). Immunofluorescence of zonula occludens-1 (ZO-1), claudin-1 and nuclear transcription factor-kappa p65 (NF-κ Bp65) were measured to determine the protein distribution. The mRNA expression of myosin light chain kinase (MLCK) was measured by real-time polymerase chain reaction. The expression levels of MLCK, myosin light chain (MLC) and p-MLC were determined by Western blot.

RESULTS

Chang'an II Decoction-containing serum significantly attenuated the TER and paracellular permeability induced by TNF-α. It alleviated TNF-α-induced morphological alterations in TJ proteins. The increases in MLCK mRNA and MLCK, MLC and p-MLC protein expressions induced by TNF-α were significantly inhibited in the Chang'an II-H group. Additionally, Chang'an II Decoction significantly attenuated translocation of NF-κ Bp65 into the nucleus.

CONCLUSION

High-dose Chang'an II-containing serum attenuates TNF-α-induced intestinal barrier dysfunction. The underlying mechanism may be involved in inhibiting the MLCK-MLC phosphorylation signaling pathway mediated by NF-κ Bp65.

Investigation on Spectrum-Effect Correlation between Constituents Absorbed into Blood and Bioactivities of Baizhu Shaoyao San before and after Processing on Ulcerative Colitis Rats by UHPLC/Q-TOF-MS/MS Coupled with Gray Correlation Analysis

Baizhu Shaoyao San (BSS) is a crucial traditional Chinese medicinal formula widely applied for the treatment of painful diarrhea, diarrhea-predominant irritable bowel syndrome, ulcerative colitis, and some other gastrointestinal diseases. Corresponding to the clinical medication, the three medicinal herbs (Atractylodis Macrocephalae Rhizoma, Paeoniae Radix Alba, and Citri Reticulatae Pericarpium) included in BSS should be processed using some specific methods of stir-frying. To find the underlying correlations between serum chemical profiles and curative effects of crude and processed BSS on ulcerative colitis rats, and further explore for the effective material basis of processing, an UHPLC/Q-TOF-MS/MS technique coupled with gray correlation analysis (GCA) was developed. A total of 134 compounds were identified in rat sera after oral administration of BSS, among which 24 compounds were prototypes and 110 compounds were metabolites. Meanwhile, an ulcerative colitis model was established in rats by enema with 2,4,6-trinitrobenzene sulfonic acid, and the pharmacodynamic indicators for drug efficacies were evaluated as well. According to the results, processed BSS showed better efficacy than crude BSS. The top 10 potential effective components with high degree of correlation were identified based on GCA results, which were thought to be the crucial compounds that contributed to the enhancement of therapeutic effects in BSS after processing.

Chemical profiles and pharmacological activities of Chang-Kang-Fang, a multi-herb Chinese medicinal formula, for treating irritable bowel syndrome

ETHNOPHARMACOLOGICAL RELEVANCE

Chang-Kang-Fang formula (CKF), a multi-herb traditional Chinese medicinal formula, has been clinically used for treatment of irritable bowel syndrome (IBS). The mechanisms of CKF for treating IBS and the components that are responsible for the activities were still unknown.

AIM OF THE STUDY

To investigate the chemical profiles and effects of CKF on IBS model.

MATERIALS AND METHODS

The chemical profiles of CKF were investigated by ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-Q/TOF-MS/MS). On colon irritation induced rat neonates IBS model, the influence of CKF on neuropeptides, including substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal polypeptide (VIP) and 5-hydroxytryptamine (5-HT), were measured by ELISA, and the effect on intestinal sensitivity was assessed based on the abdominal withdrawal reflex (AWR) scores. In addition, the activities of CKF against acetic acid-induced nociceptive responses and prostigmin methylsulfate triggered intestinal propulsion in mice were also evaluated.

RESULTS

80 components were identified or tentatively assigned from CKF, including 11 alkaloids, 20 flavanoids, 4 monoterpenoids, 9 iridoid glycoside, 9 phenylethanoid glycosides, 10 chromones, 7 organic acid, 3 coumarins, 2 triterpene and 5 other compounds. On IBS rat model, CKF was observed to reduce AWR scores and levels of SP, CGRP, VIP and 5-HT. Moreover, CKF reduced the acetic acid-induced writhing scores at all dosages and reduced the intestinal propulsion ration at dosage of 7.5 and 15.0g/kg/d.

CONCLUSIONS

CKF could alleviate the symptoms of IBS by modulating the brain-gut axis through increasing the production of neuropeptides such as CGRP, VIP, 5-HT and SP, releasing pain and reversing disorders of intestinal propulsion. Berberine, paeoniflorin, acteoside, flavonoids and chromones may be responsible for the multi-bioactivities of CKF.

The Effect of Tong-Xie-Yao-Fang on Intestinal Mucosal Mast Cells in Postinfectious Irritable Bowel Syndrome Rats

Objective. To investigate the effects of Tong-Xie-Yao-Fang (TXYF) on intestinal mucosal mast cells in rats with postinfectious irritable bowel syndrome (PI-IBS). Design. PI-IBS rat models were established using a multistimulation paradigm. Then, rats were treated with TXYF intragastrically at doses of 2.5, 5.0, and 10.0 g·kg⁻¹·d⁻¹ for 14 days, respectively. Intestinal sensitivity was assessed based on abdominal withdrawal reflex (AWR) scores and fecal water content (FWC). Mast cell counts and the immunofluorescence of tryptase and c-Fos in intestinal mucosa were measured; and serum IL-1β, TNF-α, and histamine levels were determined. Results. AWR reactivity and FWC which were significantly increased could be observed in PI-IBS rats. Remarkably increased mast cell activation ratio in intestinal mucosa, together with increased serum TNF-α and histamine levels, could also be seen in PI-IBS rats; furthermore, PI-IBS-induced changes in mast cell activation and level of serum TNF-α and histamine could be reversed by TXYF treatment. Meanwhile, tryptase and c-Fos expression were also downregulated. Conclusion. TXYF improves PI-IBS symptoms by alleviating behavioral hyperalgesia and antidiarrhea, the underlying mechanism of which involves the inhibitory effects of TXYF on activating mucosal mast cells, downregulating tryptase and c-Fos expression, and reducing serum TNF-α and histamine levels.

Vitamin D improves immune function in immunosuppressant mice induced by glucocorticoid

Vitamin D is an essential fat-soluble vitamin with multiple functions. Vitamin D receptor has been shown to be expressed in several types of immune cells suggesting vitamin D may have immune regulatory roles. Vitamin D insufficiency has been suggested to increase the risk of autoimmune diseases. However, little is known regarding its immunomodulatory effects in the condition of immune suppression. The aim of the present study was to investigate the regulatory effects of vitamin D on immune function in immunosuppressant mice. An immunosuppressant mouse model was induced by intraperitoneal injection with glucocorticiod for 3 days. Immunosuppressant mice were intragastrically administered with 1,25-dihydroxy-vitamin D3 [1,25(OH)₂D₃; 0,4, 6 or 10 IU/g body weight] for 7 days. On day 8, the mice were decapitated. The body weight and the weights of thymus and spleen were measured. Thymus and spleen indexes were calculated. The ratio of CD4⁺/CD8⁺ T lymphocytes in the peripheral blood, proliferation and interleukin-2 (IL-2) production of spleen T lymphocytes was detected. Compared with the mice in the control group, the body weight, thymus and spleen indexes, the ratios of CD4⁺/CD8⁺ in peripheral blood and IL-2 production and proliferation of spleen T lymphocytes were decreased in immunosuppressant mice induced by glucocorticiod. However, in vitamin D-treated mice, the thymus indexes, the ratios of CD4⁺/CD8⁺, secretion of IL-2 and the proliferation index of spleen T lymphocytes were significantly increased (P<0.05). Among the three doses of 1,25(OH)₂D₃, 6 IU/g was most effective in improving the immune function. These results indicate that vitamin D supplementation can improve immune recovery in immunosuppressant mice by stimulating T-cell proliferation and elevating IL-2 production.

Fermented Herbal Formulas KIOM-MA128 Ameliorate IL-6-Induced Intestinal Barrier Dysfunction in Colon Cancer Cell Line

Inflammatory bowel disease (IBD) comprises Crohn's disease (CD) and ulcerative colitis (UC). IBD increases the risk of colorectal cancer (CRC), depending on the extent and duration of intestinal inflammation. Increased IL-6 expression has been reported in IBD patients, which may be associated with intestinal barrier function through discontinuous tight junction (TJ). KIOM-MA is a specific agent for allergic diseases and cancer, and it is composed of several plants; these herbs have been used in traditional oriental medicine. We fermented KIOM-MA, the product of KIOM-MA128, using probiotics to improve the therapeutic efficacy via the absorption and bioavailability of the active ingredients. In this study, we demonstrated that KIOM-MA/MA128 exhibited anticolitis effects via the modulation of TJ protein. Interleukin-6 resulted in a dose-dependent decrease in the TER and an increase in the FITC-dextran permeability; however, pretreatment with 400 µg/ml KIOM-MA/MA128 resulted in a significant increase in the TER and a decrease in the FITC-dextran permeability via IL-6 induction. Furthermore, protein and mRNA TJ levels remained stable after pretreatment with 400 µg/ml KIOM-MA/MA128. Moreover, KIOM-MA/MA128 suppressed the expression of PLCγ1 and PKC. Taken together, these findings suggest novel information and clue of the anticolitis effects of KIOM-MA128 via regulation of tight junction.