The inhibitory effect of tongxieyaofang on rats with post infectious irritable bowel syndrome through regulating colonic par-2 receptor

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.

Tong-Xie-Yao-Fang Induces Mitophagy in Colonic Epithelial Cells to Inhibit Colitis-associated Colorectal Cancer

ETHNOPHARMACOLOGICAL RELEVANCE

Based on the core pathogenesis of hepatosplenic disorder and qi transformation disorder in ulcerative colitis, Tong-Xie-Yao-Fang (TXYF) is a classical traditional Chinese medicine commonly used to treat ulcerative colitis. Our study revealed that it has the potential to prevent colitis-associated colorectal cancer, which embodies the academic concept in traditional Chinese medicine of treating the disease before it develops.

AIM OF THE STUDY

This study was aimed at evaluating the therapeutic role of TXYF in treating colitis-associated colorectal cancer and exploring its possible underlying mechanisms.

MATERIALS AND METHODS

A colitis-associated colorectal cancer model was established in mice using azoxymethane and dextran sulfate sodium salt to examine the therapeutic effect of TXYF. The mouse body weights were observed. Hematoxylin-eosin staining was used to evaluate mouse colon histopathology. Colon cancer cells and colon epithelial cells were used to explore the potential molecular mechanisms. The proliferation and apoptosis of cells were detected by CCK-8 and cell colony assays, flow cytometry and western blotting. The epithelial-mesenchymal transition (EMT) and mitophagy markers were examined by immunohistochemistry, western blotting, quantitative real-time PCR and immunofluorescence staining.

RESULTS

TXYF inhibited the tumorigenesis of mice with colitis-associated colorectal cancer and the growth of inflammatory colon cells. TXYF induced mitophagy in colon cancer cells through the PTEN-induced putative kinase 1 (PINK1)/Parkin pathway to reverse EMT, which was consistent with the results in mice with colitis-associated colorectal cancer.

CONCLUSIONS

The results of the present study demonstrated that TXYF effectively inhibited the progression of colitis-associated colorectal cancer through the PINK1/Parkin pathway, which provides new evidence for prevention strategies for this disease.

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.

An Overview of Systematic Reviews of Herbal Medicine for Irritable Bowel Syndrome

Background: Irritable bowel syndrome (IBS) is a common disorder with abdominal pain and bowel habits changes. Herbal medicines (HMs) are frequently used in the treatment of IBS. Therefore, several systematic reviews (SRs) have been conducted to assess the efficacy and safety of HM in IBS patients. This study aimed to investigate the methodology and quality of evidence of SRs, and to describe the current state of research and evidence for the treatment of IBS with HM.

Methods: SRs published up to January 2022 were searched using six electronic databases. SRs and/or meta-analyses on the use of HMs for IBS were included. The effects of placebo, conventional medicine (CM), and probiotics were compared with those of HMs. Two investigators independently extracted the data and assessed methodological quality using the Measure Tool to Assessment System Reviews 2 (AMSTAR 2). Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) was used to evaluate the quality of evidence for each main finding.

Results: Eighteen SRs were included in this overview. Among them, eight SRs reported only specific subtypes of IBS: six SRs reported patients with diarrhea-predominant IBS, and two SRs reported patients with constipation-predominant IBS. In terms of total efficacy, HM was more effective than placebo, CM, or probiotics. HM showed a more significant effect than CM in relieving independent IBS symptom score (abdominal pain score, diarrhea score, abdominal distension score, stool frequency score, etc.) and recurrence rate. The rate of adverse events was significantly lower with HM compared to CM, and no serious adverse events were reported with HM treatment. According to AMSTAR 2, the methodological quality of the included SRs was extremely low. Furthermore, the quality of evidence for total efficacy was considered low or very low according to the GRADE tool.

Conclusion: HM can be considered as an effective and safe treatment for IBS. However, the methodological quality of the included SRs and the quality of evidence was generally low. Therefore, well-designed randomized controlled trials are needed in the future so that a high-quality SR can be used to better assess the safety and efficacy of HM in the treatment of IBS.

Systematic Review Registration:https://osf.io/nt6wz, identifier 10.17605/OSF.IO/NT6WZ.

Mechanism by Which Tong Xie Yao Fang Heals the Intestinal Mucosa of Rats with Ulcerative Colitis through the Hippo Pathway

Objective

Tong Xie Yao Fang (TXYF) is a classic and effective prescription in traditional Chinese medicine which is used to treat ulcerative colitis (UC). Our study investigated the effect of TXYF on Hippo pathway activation in UC-induced intestinal mucosa injury and explored the possible mechanism.

Method

After ulcerative colitis was successfully induced by trinitrobenzene sulfonic acid (TNBS), 48 Sprague Dawley (SD) rats were randomly divided into a control group, model group, TXYF group, and sulfasalazine group and treated with the corresponding drugs for 28 days. The parameters including body weight, colon length, spleen index, and disease activity index (DAI) and histopathological characteristics were assessed. The myeloperoxidase (MPO) activity and IL-6 level in the colon mucosa were determined with the corresponding commercial kits. The expressions of the Hippo pathway components YAP1, TAZ, P-YAP, and LATS1 were detected in the colon mucosa of each group on different stages by quantitative real-time PCR (qRT-PCR) and western blotting. Immunohistochemical staining was used to evaluate the growth and apoptosis of the colon epithelium.

Result

TXYF significantly improved the weight loss, colonic shortening, DAI, spleen enlargement, and histopathological score of the rats with TNBS-induced UC. TXYF also reduced the MPO activity and expression of IL-6 in the colon mucosa. Furthermore, treatment with TXYF significantly increased YAP1 expression in the early stage (3–7 days) and significantly decreased YAP1 expression in the late stage (14–28 days). In the early stage, TXYF inhibited Hippo pathway activity, which promoted proliferation and regeneration of the intestinal mucosa. In the late stage, the Hippo pathway was activated, thereby inhibiting apoptosis and promoting intestinal mucosal differentiation.

Conclusion

TXYF alleviated the inflammatory response and promoted mucosal healing in rats with UC, which was probably achieved through the Hippo pathway. These results indicated that TXYF was a potential therapy for treating UC.

Acupuncture combined with Tongxieyaofang for diarrhea-type irritable bowel syndrome: A protocol for meta-analysis

BACKGROUND

As a traditional Chinese medicine external treatment method, acupuncture is characterized by simple operation, significant treatment effect and few side effects. Tong-Xie-Yao-Fang (TXYF), a Chinese patent medicine, combined with acupuncture has been widely used on treating Diarrhea Predominant Irritable Bowel Syndrome (IBS-D). However, the efficacy and safety of TXYF combined with acupuncture for the treatment of IBS-D are unclear. This study aims to investigate verify the efficacy and safety of TXYF combined with acupuncture for IBS-D.

METHODS AND ANALYSIS

Randomized controlled trials of TXYF combined with acupuncture for all IBS-D will be searched in PubMed, the Cochrane Library, Embase, Web of Science, the China National Knowledge Infrastructure, Wanfang Database, Chinese Science and Technology Periodical Database, and Chinese Biomedical Literature Database from inception to October 20, 2020. And Baidu Scholar, Google Scholar, International Clinical Trials Registry Platform, and Chinese Clinical Trials Registry will be searched to obtain more relevant studies comprehensively. The methodological qualities, including the risk of bias, will be evaluated using the Cochrane risk of bias assessment tool, while confidence in the cumulative evidence will be evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Two researchers will perform data extraction and risk of bias assessment independently. Statistical analysis will be conducted in RevMan 5.3.

RESULTS

Based on the current evidence, the potential rank of the efficacy and safety of TXYF plus acupuncture for IBS-D will be assessed.

CONCLUSION

The findings of the study will provide helpful evidence for the efficacy and safety of TXYF combined with acupuncture in the treatment of IBS-D, facilitating clinical practice and further scientific studies.

Immunization with cytolethal distending toxin B produces autoantibodies to vinculin and small bowel bacterial changes in a rat model of postinfectious irritable bowel syndrome

BACKGROUND

Recent data substantiate the importance of acute gastroenteritis in the development of irritable bowel syndrome (IBS). An animal model of postinfectious IBS determined the importance of cytolethal distending toxin B (CdtB) during live Campylobacter jejuni infection and its development of autoimmunity to vinculin. In this study, we examine whether subcutaneous exposure to CdtB alone is sufficient to produce the postinfectious IBS effect and autoimmunity.

METHODS

Sixty adult Sprague Dawley rats were randomized into 2 groups to receive subcutaneous injection of either CdtB or vehicle and administered a booster injection of the same product 3 weeks later. Serum was collected for anti-CdtB and anti-vinculin titers. Duodenal and ileal luminal contents for total eubacterial qPCR, and ileal bowel segments were harvested for vinculin and ileal expression. In a second experiment, 4 adult, Sprague Dawley rats were injected with either Cy7-labeled anti-CdtB and anti-vinculin antibodies were injected into the tail vein and imaged to determine organ localization of the antibodies.

KEY RESULTS

Rats that received CdtB increased in serum anti-CdtB after injection. CdtB exposure also precipitated significant elevation in anti-vinculin antibodies (P < .001). This was associated with a reduction in intestinal vinculin expression (P < .001) that negatively correlated with serum anti-CdtB levels. CdtB exposure was also associated with greater levels of duodenal (P < .001) and ileal (P < .01) bacteria by qPCR that positively correlated with anti-CdtB levels.

CONCLUSIONS AND INFERENCES

Rats injected with CdtB developed a postinfectious IBS-like phenotype and autoimmunity to vinculin with corresponding reduction in intestinal vinculin expression.

Acupuncture plus Chinese Herbal Medicine for Irritable Bowel Syndrome with Diarrhea: A Systematic Review and Meta-Analysis

PURPOSE

To comprehensively evaluate the efficacy and safety of acupuncture combined with Chinese herbal medicine (CHM) in treating irritable bowel syndrome with diarrhea (IBS-D).

METHODS

Relevant randomized controlled trials (RCTs) were systemically retrieved from electronic databases from inception to March 2018, including the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, EMBASE, China National Knowledge Infrastructure (CNKI), Chinese Biological Medical Database (CBM, SinoMed), China Science and Technology Journal Database (VIP), and Wan Fang Data. Meanwhile, pooled estimates, including the 95% confidence interval (CI), were calculated for primary and secondary outcomes of IBS-D patients. Besides, quality of relevant articles was evaluated using the Cochrane Collaboration's risk of bias tool, and the Review Manager 5.3 and Stata12.0 softwares were employed for analyses.

RESULTS

A total of 21 RCTs related to IBS-D were included into this meta-analysis. Specifically, the pooled results indicated that (1) acupuncture combined with CHM might result in more favorable improvements compared with the control group (relative risk [RR] 1.29; 95% CI 1.24-1.35; P =0.03); (2) the combined method could markedly enhance the clinical efficacy in the meantime of remarkably reducing the scores of abdominal pain (standardized mean difference [SMD] -0.45; 95% CI -0.72, -0.17; P = 0.002), abdominal distention/discomfort (SMD -0.36; 95% CI -0.71, -0.01; P = 0.04), diarrhea (SMD -0.97; 95% CI -1.18, -0.75; P < 0.00001), diet condition (SMD -0.73; 95% CI -0.93, -0.52; P<0.00001), physical strength (SMD -1.25; 95% CI -2.32, -0.19; P = 0.02), and sleep quality (SMD -1.02; 95% CI -1.26, -0.77; P < 0.00001) compared with those in the matched groups treated with western medicine, or western medicine combined with CHM. Additionally, a metaregression analysis was constructed according to the name of prescription, acupuncture type, treatment course and publication year, and subgroup analyses stratified based on the names of prescriptions and acupoints location were also carried out, so as to explore the potential heterogeneities; and (3) IBS-D patients treated with the combined method only developed inconspicuous adverse events; more importantly, the combined treatment had displayed promising long-term efficacy.

CONCLUSIONS

Findings in this study indicate that acupuncture combined with CHM is suggestive of an effective and safe treatment approach for IBS-D patients, which may serve as a promising method to treat IBS-D in practical application. However, more large-scale, multicenter, long-term, and high-quality RCTs are required in the future, given the small size, low quality, and high risk of the studies identified in this meta-analysis.

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.

Clinical Effects and Safety of Tongxieyaofang on Diarrhea Predominant Irritable Bowel Syndrome: A Meta-Analysis of Randomized Trails

Background. Tongxieyaofang (TXYF), a prescription originated from traditional Chinese medicine (TCM), has been widely used on treating Diarrhea Predominant Irritable Bowel Syndrome (IBS-D). The purpose of this meta-analysis was to investigate whether TXYF was effective and safe for IBS-D. Methods. We searched seven electronic databases including CENTRAL, MEDLINE, PubMed, CNKI, VIP, CBM, and Wanfang Data up to 26 July 2017. Randomized controlled trails (RCTs) were eligible, regardless of blinding. Risk of bias of included trials was evaluated according to the Cochrane Handbook. Results. The total number of participants analyzed in the meta-analysis was 3062, of which 1556 received TXYF, while 1506 received ordinary treatment. The primary outcome was clinical effective rate. Compared with conventional medication which included probiotics, pinaverium bromide, trimebutine, and Oryzanol, TXYF significantly improved the clinical effective rate (n=37, OR: 4.61; 95% CI: 3.67–5.78; P < 0.00001) and decreased the adverse events (n=10, OR: 0.26; 95% CI: 0.08–0.86; P = 0.03). There was not significant association with the score of abdominal pain, defecating frequency, fecal property, and total symptom. Conclusions. We suggested a moderate recommendation for TXYF on IBS-D, due to the fact that the risk of bias of the finally included trails was not high. Considering that all identified studies were not of high qualities and large samples, further rigorously designed and large scale RCTs were necessary to improve the applicability of our study results.

Mucosa repair mechanisms of Tong-Xie-Yao-Fang mediated by CRH-R2 in murine, dextran sulfate sodium-induced colitis

AIM

To explore the significance of corticotropin-releasing hormone (CRH)-receptor (R)2 in mucosal healing of dextran sulfate sodium (DSS)-induced colitis and the effect of Tong-Xie-Yao-Fang (TXYF) on CRH-R2 expression and regulation.

METHODS

Ulcerative colitis was induced in mice by administration of 3% (w/v) DSS for 7 d. Once the model was established, mice were administered urocortin-2 (30 μg/kg), a peptide which binds exclusively to CRH-R2, or various doses of aqueous TXYF extracts (2.8-11.2 g/kg), a CRH-R2 antagonist Astressin (Ast)2B (20 μg/kg), Ast2B + Ucn2, or Ast2B with various doses of aqueous TXYF extracts for 9 d. Colonic mucosal permeability was then evaluated by measuring the fluorescence intensity in serum. The colitis disease activity index (DAI), histology, body weight loss and colon length were assessed to evaluate the condition of colitis. Terminal deoxynucleotidyl transferase dUTP nick-end labeling was used to detect apoptosis of the intestinal epithelial cells. The expression level of Ki-67 represented the proliferation of colonic epithelial cells and was detected by immunohistochemistry. The expression levels of inflammation cytokines IL-6, TNF-α and CXCL-1 were examined in colon tissues using real-time PCR and ELISA kits.

RESULTS

Compared with the DSS group, mice treated with the CRH-R2 antagonist Ast2B showed greater loss of body weight, shorter colon lengths (4.90 ± 0.32 vs 6.21 ± 0.34 cm, P < 0.05), and higher DAI (3.61 ± 0.53 vs 2.42 ± 0.32, P < 0.05) and histological scores (11.50 ± 1.05 vs 8.33 ± 1.03, P < 0.05). Additionally, the Ast2B group showed increased intestinal permeability (2.76 ± 0.11 μg/mL vs 1.47 ± 0.11 μg/mL, P < 0.001), improved secretion of inflammatory cytokines in colon tissue, and reduced colonic epithelial cell proliferation (4.97 ± 4.25 vs 22.51 ± 8.22, P < 0.05). Increased apoptosis (1422.39 ± 90.71 vs 983.01 ± 98.17, P < 0.001) was also demonstrated. The Ucn2 group demonstrated lower DAI (0.87 ± 0.55 vs 2.42 ± 0.32, P < 0.001) and histological scores (4.33 ± 1.50 vs 8.33 ± 1.03, P < 0.05). Diminished weight loss, longer colon length (9.58 ± 0.62 vs 6.21 ± 0.34 cm, P < 0.001), reduced intestinal permeability (0.75 ± 0.07 vs 1.47 ± 0.11 μg/mL, P < 0.001), inhibited secretion of inflammatory cytokines in colon tissue and increased colonic epithelial cell proliferation (90.04 ± 15.50 vs 22.51 ± 8.22, P < 0.01) were all observed. Reduced apoptosis (149.55 ± 21.68 vs 983.01 ± 98.17, P < 0.05) was also observed. However, significant statistical differences in the results of the Ast2B group and Ast2B + Ucn2 group were observed. TXYF was also found to ameliorate symptoms of DSS-induced colitis in mice and to promote mucosal repair like Ucn2. There were significant differences between the Ast2B + TXYF groups and the TXYF groups.

CONCLUSION

CRH-R2 activates the intestinal mucosal antiinflammatory response by regulating migration, proliferation and apoptosis of intestinal epithelial cells in colitis-induced mice, and plays an important antiinflammatory role. TXYF promotes mucosal repair in colitis mice by regulating CRH-R2.

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.

Post-infectious and non post-infectious irritable bowel syndrome: A comparative study

Objective:

To compare the post-infectious irritable bowel syndrome (PI-IBS) and none post-infectious irritable bowel syndrome (NPI-IBS) clinically and experimentally.

Methods:

From May 2013 to January 2015, eighty-nine patients with irritable bowel syndrome (IBS)were recruited in the internal department of the affiliated hospital of Shandong University of Traditional Chinese Medicine. The clinical data were collected for all the patients, and a blood sample was collected to detect the level of C-reactive protein (CRP) and intestinal fatty acid binding protein (IFABP), an investigation questionnaire of gastrointestinal symptom rating scale (GSRS) and self-rating anxiety scale (SAS) were carried out to evaluate the gastrointestinal function and anxiety status.

Results:

In the study, forty-eight patients were included in PI-IBS group and 41 in Non-PI-IBS group. There was no significant difference in age, gender and GSRS between the two groups (p>0.05). In PI-IBS group 70.8% patients presented with the primary symptom of diarrhea and 60.4% presented with a SAS scores over 50, but in Non-PI-IBS group, the values were only 19% (p<0.05) and 34.1% (p<0.05). The level of IFABP and CRP were significantly higher in PI-IBS group than those in Non-PI-IBS group (p<0.05).

Conclusion:

The PI-IBS may be different from Non-PI-IBS in mechanism and should be treated using different strategies.

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

AIM

The herbal prescription Chang'an II is derived from a classical TCM formula Tong-Xie-Yao-Fang for the treatment of liver-qi stagnation and spleen deficiency syndrome of irritable bowel syndrome (IBS). In this study we investigated the effects of Chang'an II on the intestinal mucosal immune barrier in a rat post-inflammation IBS (PI-IBS) model.

METHODS

A rat model of PI-IBS was established using a multi-stimulation paradigm including early postnatal sibling deprivation, bondage and intrarectal administration of TNBS. Four weeks after TNBS administration, the rats were treated with Chang'an II (2.85, 5.71 and 11.42 g · kg(-1) · d(-1), ig) for 14 d. Intestinal sensitivity was assessed based on the abdominal withdrawal reflex (AWR) scores and fecal water content. Open field test and two-bottle sucrose intake test were used to evaluate the behavioral changes. CD4(+) and CD8(+) cells were counted and IL-1β and IL-4 levels were measured in intestinal mucosa. Transmission electron microscopy was used to evaluate ultrastructural changes of the intestinal mucosal barrier.

RESULTS

PI-IBS model rats showed significantly increased AWR reactivity and fecal water content, and decreased locomotor activity and sucrose intake. Chang'an II treatment not only reduced AWR reactivity and fecal water content, but also suppressed the anxiety and depressive behaviors. Ultrastructural study revealed that the gut mucosal barrier function was severely damaged in PI-IBS model rats, whereas Chang'an II treatment relieved intestinal mucosal inflammation and repaired the gut mucosal barrier. Furthermore, PI-IBS model rats showed a significantly reduced CD4(+)/CD8(+) cell ratio in lamina propria and submucosa, and increased IL-1β and reduced IL-4 expression in intestinal mucosa, whereas Chang'an II treatment reversed PI-IBS-induced changes in CD4(+)/CD8(+) cell ratio and expression of IL-1β and IL-4.

CONCLUSION

Chang'an II treatment protects the intestinal mucosa against PI-IBS through anti-inflammatory, immunomodulatory and anti-anxiety effects.

Animal models of gastrointestinal and liver diseases. Animal models of visceral pain: pathophysiology, translational relevance, and challenges

Visceral pain describes pain emanating from the thoracic, pelvic, or abdominal organs. In contrast to somatic pain, visceral pain is generally vague, poorly localized, and characterized by hypersensitivity to a stimulus such as organ distension. Animal models have played a pivotal role in our understanding of the mechanisms underlying the pathophysiology of visceral pain. This review focuses on animal models of visceral pain and their translational relevance. In addition, the challenges of using animal models to develop novel therapeutic approaches to treat visceral pain will be discussed.

NMDA and AMPA receptors in the anterior cingulate cortex mediates visceral pain in visceral hypersensitivity rats

Several studies have shown that N-methyl-D-aspartate (NMDA)-receptor activation in anterior cingulate cortex (ACC) neurons plays critical roles in modulating visceral pain responses in visceral hypersensitivity (VH) rats. However, there are few reports about the expressions of NMDA and α-amino-3-hydroxy-5-methyl-4-isox-azolepropionic-acid (AMPA) receptor subtypes in ACC of VH model rats at different time points. The current study was undertaken to investigate NR2A, NR2B and GluR2 expressions in ACC of VH rats that were induced by administration with 5% mustard oil. Our results indicated that NR2B, but not NR2A, was highly expressed in VH model group on day 15, 22, and 36 compared with normal group (p < 0.05). GluR2 expression was also higher in VH model group on day 15, 22, and 36 than that of normal group (p < 0.05). These findings suggested increased expression of NR2B and GluR2 might be key mechanisms for long-term synaptic plastic changes in VH rats.