Nitric oxide in inflammatory bowel disease

Acid-resistant chemotactic DNA micromotors for probiotic delivery in inflammatory bowel disease

Microcapsules composed of synthetic polymeric matrices have attracted considerable attention in delivering oral probiotics. However, existing polymeric microcapsules demonstrate inadequate acid resistance and adaptability, as well as deficiency in the inflamed colon-specificity and uncontrolled release of probiotics therein. Herein, a DNA microcapsule is prepared as a probiotic-transporting micromotor through photo-crosslinking of hyaluronic acid methacrylate and acrydite-modified A-/C-rich oligomers within the microfludically generated droplets in the presence of nitric oxide-cleavable crosslinker and gas donor manganese carbonyl (MnCO). As the microcapsules traverse stomach, duodenum, and ultimately colon, the formation and dissociation of A-motif and i-motif structures instigate a reversible shrinking-swelling transition of microcapsules to preserve probiotic viability. Subsequently, the microcapsules exhibit chemotaxis towards inflamed colon site, driven by a gas-generating reaction between MnCO and elevated reactive oxygen species. Following disintegration of the microcapsules, triggered by endogenous nitric oxide, probiotics are released to reshape the dysbiosis of intestinal microflora. This advanced delivery system offers significant promise for the effective clinical management of inflammatory bowel disease.

CNPY2 drives DSS-induced colitis via the macrophage-ROS axis

Inflammatory bowel disease (IBD) is a chronic inflammatory condition of the gastrointestinal tract, driven by genetic, environmental, and immune system factors. However, its exact mechanisms remain unclear. Here, we demonstrate that CNPY2 plays a critical role in colitis by modulating macrophage activity. Mice with whole-body Cnpy2 knockout (KO) exhibited significantly reduced dextran sodium sulfate (DSS)-induced colitis compared to wild-type controls. Cnpy2 KO mice showed less mucosal barrier disruption and fewer lamina propria macrophages (LPMφs) following DSS treatment. Proinflammatory cytokine production was also diminished in the colons of Cnpy2 KO mice. Furthermore, Cnpy2 KO macrophages generated markedly lower levels of reactive oxygen species (ROS), partly through CHOP regulation. Notably, treatment with the ROS scavenger N-acetyl-L-cysteine (NAC) completely abolished DSS-induced colitis in Cnpy2 KO mice. Thus, CNPY2 exacerbates DSS-induced colitis primarily through macrophage-specific effects, with ROS upregulation being central to its pathogenic role.

Anti-Inflammatory and Antimicrobial Effects of Herbal Formulation Called Apo-Taat Using Extended-Spectrum ß-Lactamase-Producing Escherichia coli Isolates

Pathogens contaminate drinking water in tropical countries causing diarrheal diseases. The conventional treatment for diarrhea is antibiotics. However, overuse and misuse of antibiotics has enabled pathogens to adapt, causing global antibiotic resistance and proliferation of extended-spectrum ß-lactamase-producing Escherichia coli (ESBL-E. coli), which causes diarrhea and high levels of inflammatory cytokines. Apo-taat, consisting of equal proportions of Phyllanthus emblica and Caesalpinia sappan, has been used to treat diarrhea and bloody diarrhea. Its antibacterial activity against E. coli ATCC 25922 has been reported, but its inhibitory effect against ESBL-E. coli has yet to be documented. This study investigated the antibacterial effect of Apo-taat extract against ESBL-E. coli and its anti-inflammatory activity. Antibacterial activity was determined by the microtiter plate-based method. HPLC was used to determine the brazilin and gallic acid contents in Apo-taat extract. Effects of herbal extracts on nitric oxide, IL-6, and TNF-α were investigated in RAW 264.7 cells. Results were that Apo-taat extract showed MIC values against ESBL-E. coli in the range of 0.625 to 2.5 mg/mL. Its 50% inhibitory concentration against nitric oxide and IL-6 production was 83.96 ± 10.60 and 83.06 ± 2.07 μg/mL, respectively, and it had slight inhibition against TNF-α. These findings suggest that Apo-taat may have an antibacterial impact on ESBL-E. coli and anti-inflammatory activity. Furthermore, safety and clinical trials should be conducted in the future.

Indigo naturalis as a potential drug in the treatment of ulcerative colitis: a comprehensive review of current evidence

CONTEXT

Ulcerative colitis (UC) is an intractable inflammatory bowel disease that threatens the health of patients. The limited availability of therapeutic strategies makes it imperative to explore more efficient and safer drugs. Indigo naturalis (IN) is a traditional Chinese medicine that possesses many pharmacological activities, including anti-inflammatory, antioxidant, and immunomodulatory activities. The treatment potential of IN for UC has been proven by numerous preclinical and clinical studies in recent years.

OBJECTIVE

This article provides a comprehensive review of the utility and potential of IN in the treatment of UC.

METHODS

'Indigo naturalis' 'Qing dai' 'Qingdai' 'Ulcerative colitis' and 'UC' are used as the keywords, and the relevant literature is collected from online databases (Elsevier, PubMed, and Web of Science).

RESULTS AND CONCLUSION

Indirubin, indigo, isatin, tryptanthrin, and β-sitosterol are considered the key components in the treatment of UC with IN. Both preclinical and clinical studies support the efficacy of IN for UC, especially in severe UC or in those who do not respond to or have poor efficacy with existing therapies. The mechanisms of IN for UC are associated with the aryl hydrocarbon receptor pathway activation, immune regulation, oxidative stress inhibition, and intestinal microbial modulation. However, the clinical use of IN has the risks of adverse events such as pulmonary hypertension, which suggests the necessity for its rational application. As a potential therapeutic agent for UC that is currently receiving more attention, the clinical value of IN has been initially demonstrated and warrants further evaluation.

Anti-Inflammatory Effects and Metabolomic Analysis of Ilex Rotunda Extracted by Supercritical Fluid Extraction

Ilex rotunda is a famous medicinal plant with many ethnopharmacological uses. It is traditionally employed for treating inflammation and cardiovascular diseases. In this study, we established green technology to extract the leaves and twigs of I. rotunda. The obtained extracts and their fractions were evaluated for their anti-inflammatory potential. In cytokine assays, the extract, n-hexane (H), methylene chloride (MC), and EtOAc (E) fractions of the twigs of I. rotunda significantly inhibited lipopolysaccharide (LPS)-induced nitric oxide (NO), interleukin (IL)-6, and tumor necrosis factor (TNF)-α production in RAW264.7 macrophages. Furthermore, the extract, H, and MC fractions of the leaves of I. rotunda modulated cytokine expression by downregulating LPS-induced NO, IL-6, and TNF-α production in RAW264.7 macrophages. Western blotting analysis revealed that the extracts and fractions of the leaves and twigs of I. rotunda inhibited inflammatory cytokines by inactivating nuclear factor kappa B (NFκB) action by reducing the phosphorylation of transcript factor (p65) and nuclear factor-kappa B inhibitor alpha (IκBα) degradation, or by inactivating mitogen-activated protein kinase (MAPK) through the p38 or ERK signaling pathways via the active ingredients of the leaves and twigs of I. rotunda. Ultra-high-resolution liquid chromatography-Orbitrap mass analysis (UHPLC-ESI-Orbitrap-MS/MS)-based molecular networking, in cooperation with social open platform-guided isolation and dereplication, led to the identification of metabolites in this plant. Our findings indicate that the leaves and twigs of I. rotunda could be promising candidates for developing therapeutic strategies to treat anti-inflammatory diseases.

Enhancement of Antioxidative and Anti-Inflammatory Activities of Corn Silk Polysaccharides After Selenium Modification

Objective

This study aimed to study the effect of selenium modification on the bioactivity of corn silk polysaccharides, particularly its antioxidant and anti-inflammatory functions.

Methods

HNO3-NaSeO3 was used to selenize degraded corn silk polysaccharides (DCSP). The structure and physicochemical properties of DCSP and selenized corn silk polysaccharides (Se-DCSP) were characterized by inductively coupled plasma emission spectroscopy, Fourier-transform infrared, ultraviolet-visible spectroscopy, nuclear magnetic resonance, nanometer, scanning electron microscopy, and thermogravimetric analysis. The protective effects of DCSP and Se-DCSP on HK-2 cells damaged by nano-calcium oxalate and the changes of inflammatory factors were detected by laser confocal microscopy, flow cytometry, and fluorescence microscopy.

Results

The selenium content of DCSP and Se-DCSP were 19.5 and 1226.7 μg/g, respectively. Compared with DCSP, Se-DCSP showed significantly improved biological activity, including the scavenging ability of various free radicals (increased by about 2-3 times), the intracellular reactive oxygen content (decreased by about 1.5 times), and the mitochondrial membrane potential (decreased by about 2.5 times). Moreover, cell viability and morphological recovery ability were improved. Compared with DCSP, Se-DCSP significantly down-regulated HK-2 cell inflammatory factors MCP-1 (about 1.7 times), NLRP3, and NO (about 1.5 times).

Conclusion

The antioxidant activity and the ability to down-regulate the expression of inflammatory factors of Se-DCSP were significantly enhanced compared with DCSP, and Se-DCSP can better protect HK-2 cells from oxidative damage, indicating that Se-DCSP has a stronger potential ability to inhibit kidney stone formation.

Iron regulatory protein 1 is required for the propagation of inflammation in inflammatory bowel disease

Inflammatory bowel diseases (IBDs) are complex disorders. Iron accumulates in the inflamed tissue of IBD patients, yet neither a mechanism for the accumulation nor its implication on the course of inflammation is known. We hypothesized that the inflammation modifies iron homeostasis, affects tissue iron distribution, and that this in turn perpetuates the inflammation. This study analyzed human biopsies, animal models, and cellular systems to decipher the role of iron homeostasis in IBD. We found inflammation-mediated modifications of iron distribution, and iron-decoupled activation of the iron regulatory protein (IRP) 1. To understand the role of IRP1 in the course of this inflammation-associated iron pattern, a novel cellular coculture model was established, which replicated the iron-pattern observed in vivo, and supported involvement of nitric oxide in the activation of IRP1 and the typical iron pattern in inflammation. Importantly, deletion of IRP1 from an IBD mouse model completely abolished both, the misdistribution of iron and intestinal inflammation. These findings suggest that IRP1 plays a central role in the coordination of the inflammatory response in the intestinal mucosa and that it is a viable candidate for therapeutic intervention in IBD.

Cardiovascular Risk in Patients with Inflammatory Bowel Diseases-The Role of Endothelial Dysfunction

Inflammatory bowel disease (IBD) is associated with an increased risk of cardiovascular disease (CVD). Cardiovascular pathology in people with IBD has not been well studied to date, and a direct link between cardiovascular events and IBD has not been established. The mechanisms underlying this association include the parallel and dynamic interaction of inflammation, modulation of the composition of the gut microbiota, endothelial dysfunction, thrombogenicity, and increased endothelial and epithelial permeability. Endothelial dysfunction is a common aspect of the pathogenesis of IBD and atherosclerotic CVD and can be considered one of the most important factors leading to the development and progression of cardiovascular pathology in patients with IBD. The purpose of this literature review is to describe the mechanisms underlying the development of endothelial dysfunction and disorders of the structure and function of the gut-vascular barrier in the pathogenesis of the cardiovascular manifestation of IBD.

An overview on the cellular mechanisms of anthocyanins in maintaining intestinal integrity and function

Structural and functional changes of the intestinal barrier, as a consequence of a number of (epi)genetic and environmental causes, have a main role in penetrations of pathogens and toxic agents, and lead to the development of inflammation-related pathological conditions, not only at the level of the GI tract but also in other extra-digestive tissues and organs. Anthocyanins (ACNs), a subclass of polyphenols belonging to the flavonoid group, are well known for their health-promoting properties and are widely distributed in the human diet. There is large evidence about the correlation between the human intake of ACN-rich products and a reduction of intestinal inflammation and dysfunction. Our review describes the more recent advances in the knowledge of cellular and molecular mechanisms through which ACNs can modulate the main mechanisms involved in intestinal dysfunction and inflammation, in particular the inhibition of the NF-κB, JNK, MAPK, STAT3, and TLR4 proinflammatory pathways, the upregulation of the Nrf2 transcription factor and the expression of tight junction proteins and mucins.

Effects of Inducible Nitric Oxide Synthase (iNOS) Gene Knockout on the Diversity, Composition, and Function of Gut Microbiota in Adult Zebrafish

The gut microbiota constitutes a complex ecosystem that has an important impact on host health. In this study, genetically engineered zebrafish with inducible nitric oxide synthase (iNOS or NOS2) knockout were used as a model to investigate the effects of nos2a/nos2b gene single knockout and nos2 gene double knockout on intestinal microbiome composition and function. Extensive 16S rRNA sequencing revealed substantial changes in microbial diversity and specific taxonomic abundances, yet it did not affect the functional structure of the intestinal tissues. Notably, iNOS-deficient zebrafish demonstrated a decrease in Vibrio species and an increase in Aeromonas species, with more pronounced effects observed in double knockouts. Further transcriptomic analysis of the gut in double iNOS knockout zebrafish indicated significant alterations in immune-related and metabolic pathways, including the complement and PPAR signaling pathways. These findings underscore the crucial interplay between host genetics and gut microbiota, indicating that iNOS plays a key role in modulating the gut microbial ecology, host immune system, and metabolic responses.

Impact of cow, buffalo, goat or camel milk consumption on oxidative stress, inflammation and immune response post weaning time

Milk is a whitish liquid that is secreted from mammary glands; and considered as the primary source of nutrition for newborns since they are not able to digest solid food. However, it contains primary nutrients, as well as growth and immune factors. Early weaning is a critical issue that face women and their babies in developing countries. To avoid infant malnutrition, they tend to use other milk types instead of baby formula. Therefore, the present study aimed to evaluate the impact of cow, buffalo, goat or camel milk consumption on oxidative stress, inflammation and immune response in male and female Sprague Dawley rats post weaning time. The amino acids, fatty acids, minerals and vitamins in the tested milk types were evaluated. Animals were divided into 5 groups (control, cow, buffalo, goat and camel milk administrated groups) (10 rats/group); each animal was administrated by 3.4 ml/day. Rats were administered with milk for 6 weeks; at the end of the 5th week, five animals of each group were isolated and the remaining five animals were immunized with sheep red blood cells (SRBCs) and kept for another week to mount immune response. The effect of different milk types on rats' immune response towards SRBCs was evaluated through pro-inflammatory cytokines, antioxidants, ESR and CRP measurement; together, with the histopathological examination of spleen samples and hemagglutination assay. Camel milk consumption reduced oxidative stress and inflammation in spleen that resulted from SRBCs immunization; in addition to, B cell stimulation that was apparent from the high level of anti-SRBCs antibodies. Camel milk is recommended for newborn consumption, due to its high-water content, unsaturated fatty acids, and vitamin C, as well as low lactose and fat content.

Management of ulcerative colitis by dichloroacetate: Impact on NFATC1/NLRP3/IL1B signaling based on bioinformatics analysis combined with in vivo experimental verification

The inflammatory response in ulcerative colitis (UC) could be relieved by the conventional immunomodulatory agents; 5-aminosalicylic acid, corticosteroids, or azathioprine. However, the low remission rates and the intolerance to these agents necessitate investigation of gene expression signature in UC that could influence the therapeutic efficacy of drugs, as well as the interference with persistence genes by novel therapeutic option. Three microarray datasets (GSE66407, GSE38713 and GSE14580) from the NCBI-GEO database were utilized. Differentially expressed genes between samples of patients with UC and healthy ones were analyzed using R software. In addition, in vivo study using oxazolone-induced UC in BALB/c mice was carried out to investigate the proposed therapeutic efficacy of dichloroacetate (DCA). The bioinformatics analysis revealed the persistence of NLRP3, NFATC1, and IL1B in UC despite treatment with common therapeutic agents. DCA administration to oxazolone-treated mice showed remarkable interference with those persistence genes. Western blotting analysis for NLRP3, NFATC1, nuclear/total NF-κB, and cleaved caspase-1 revealed the ability of DCA to reduce the expression levels of these proteins in oxazolone-treated mice. Additionally, the inflammatory cytokines IL-1β and IL-13 were reduced in colonic tissue by DCA treatment. The therapeutic efficacy of DCA was further confirmed by the apparent reduction in histopathological scoring, disease activity index, and the normalization of colon length. Therefore, DCA could be suggested as a novel and promising therapeutic option in UC based on its ability to interfere with the persistence of NFATC1/NLRP3/IL1B signaling. That merits further safety/toxicological pre-clinical assessment and update of bioavailability/metabolism data prior to clinical investigation.

Protective effects of topiramate on acetic acid-induced colitis in rats through the inhibition of oxidative stress

Ulcerative colitis is an intestinal inflammatory condition characterized by a rise in inflammatory mediator production and oxidative stress. Topiramate is an anticonvulsant agent with effectiveness on a wide range of seizures, which is anti-oxidative. This study aims to examine the protective effects of topiramate on acetic acid-induced ulcerative colitis in rats. Rats were randomly divided into four groups as follows: control, acetic acid, acetic acid + topiramate, and acetic acid + dexamethasone groups. Topiramate (100 mg/kg/day) or dexamethasone (2 mg/kg/day) was administered for six consecutive days, and ulcerative colitis was induced on the first day of the study by transrectal administration of 4% acetic acid. Four hours after the last dose of treatments, animals of each group were sacrificed, and colon tissues were removed for further macroscopic, histopathologic, and biochemical analyses. Treatment with topiramate markedly decreased colonic lesions and macroscopic scores as well as the improvement of histopathologic changes. Topiramate also effectively decreased the levels of malondialdehyde and upregulated the activity of anti-oxidative enzymes, including catalase, superoxide dismutase, and glutathione peroxidase. Our results reveal that the administration of topiramate ameliorates acetic acid-induced colitis in rats via anti-oxidative properties, and further studies may introduce it as an effective therapeutic candidate to decrease ulcerative colitis severity.

Carboxylated Pocoa polysaccharides inhibited oxidative damage and inflammation of HK-2 cells induced by calcium oxalate nanoparticles

The inhibitory effects of Chinese medicine Pocoa (PCPs) with different carboxyl group (-COOH) contents on oxidative damage and inflammatory response of renal epithelial cells and the influence of -COOH content in polysaccharides were investigated. HK-2 cell damage model was established by nanocalcium oxalate crystals (nanoCOM), and then PCPs with -COOH contents of 2.56% (PCP0), 7.48% (PCP1), 12.07% (PCP2), and 17.18% (PCP3) were used to protect the cells. PCPs could inhibit the damage of nanoCOM to HK-2 cells, increase cell viability, restore cytoskeleton and morphology, and improve lysosomal integrity. PCPs can reduce the oxidative stress response of nanoCOM to cells, inhibit the opening of mPTP and cell necrotic apoptosis, reduce the level of Ca2+ ions in cells, the production of ATP and MDA, and increase SOD expression. PCPs can also reduce the cellular inflammatory response caused by oxidative damage, and reduce the expression of nitric oxide (NO), inflammatory factors TNF-α, IL-6, IL-1β and MCP-1, as well as the content of inflammasome NLRP3. After protection, PCPs can inhibit the endocytosis of nanoCOM crystals by cells. With the increase in -COOH content in PCPs, its ability to inhibit nanoCOM cell damage, reduce oxidative stress, reduce inflammatory response, and inhibit crystal endocytosis increases, that is, PCP3 with the highest -COOH content, shows the best biological activity. Inhibiting cell damage and inflammation and reducing a large amount of endocytosis of crystals by cells are beneficial to inhibit the formation of kidney stones.

Aqueous extracts of Ocimum gratissimum mitigate colitis and protect against AOM/DSS-induced colorectal cancer in mice

In this study, we explored the in vivo effects of Ocimum gratissimum aqueous extracts (OGE) on colorectal cancer (CRC) development provoked by azoxymethane/dextran sodium sulfate (AOM/DSS). The results showed a significant reduction in the tumor load and tumor number for the OGEH group that received continued administration of OGE compared to the AOM/DSS group, with P values of <0.01, but this was not observed in the OGEHs group that received separated administration of OGE. All groups except the control group exhibited aberrant crypt foci (ACF) and adenocarcinoma of lesion pathology in colon, and both conditions were significantly reduced in the OGEH group (P < 0.01) as compared to the AOM/DSS group. Subsequent investigation into whether OGE exhibits eliminative effects on DSS-induced severe colitis (SC) in mice showed that the disease activity index score was significantly reduced in the OGE-treated groups (P < 0.01), also colon colitis histological score was reversed. These data suggest that OGE may be potentially effective in preventing CRC when administered throughout the promotional stages of carcinogenesis by inhibiting inflammatory SC.

The Antioxidant Properties of Salvia verbenaca Extract Contribute to Its Intestinal Antiinflammatory Effects in Experimental Colitis in Rats

Inflammatory bowel disease (IBD) is a chronic gastrointestinal inflammation with unpredictable symptom fluctuations. While there is no effective cure for IBD, various treatments aim to manage symptoms and improve the quality of life for affected individuals. In recent years, there has been growing interest in the potential benefits of certain natural plants and herbs in the management of IBD. In this regard, this study aimed to evaluate the immunomodulatory and anti-inflammatory effects of a well-characterized extract of Salvia verbenaca (S. verbenaca) in an experimental model of colitis in rats. Interestingly, the daily administration of S. verbenaca (10 and 25 mg/kg) effectively alleviated colitis symptoms, as evidenced by reduced weight/length ratio and colonic damage. Moreover, it reduced oxidative stress markers (MPO and GSH), decreased pro-inflammatory cytokine expression (Il-6, Il-12a, Il-1β, Il-23, Icam-1, Mcp-1, Cinc-1), and preserved the integrity of the intestinal barrier (Villin, Muc-2, Muc-3). These effects suggest S. verbenaca extract could represent a potential complementary candidate to treat gastrointestinal disorders. Its beneficial actions can be related to its antioxidant properties as well as the downregulation of the immune response, which can result in the improvement in the intestine epithelial barrier.

MEK inhibitors increase the mortality rate in mice with LPS-induced inflammation through IL-12-NO signaling

Lipopolysaccharide (LPS) is an endotoxin that can cause an acute inflammatory response. Nitric oxide (NO) is one of the most important innate immune system components and is synthesized by inducible NOS (iNOS) in macrophages in response to stimulation with LPS. LPS activates the RAS-RAF-mitogen-activated protein kinase/ERK kinase (MEK)-extracellular-signal-regulated kinase (ERK) signaling cascade in macrophages. The purpose of this study was to examine how the combination of LPS and MEK inhibitors, which have been used as anticancer agents in recent years, affects inflammation. We showed that MEK inhibitors enhanced iNOS expression and NO production in LPS-stimulated mouse bone marrow-derived macrophages. A MEK inhibitor increased the mortality rate in mice with LPS-induced inflammation. The expression of the cytokine interleukin-12 (IL-12) in macrophages was enhanced by the MEK inhibitor, as shown by a cytokine array and ELISA. IL-12 enhanced iNOS expression and NO production in response to LPS. We also showed that tumor necrosis factor (TNF-α) was secreted by macrophage after stimulation with LPS and that TNF-α and IL-12 synergistically induced iNOS expression and NO production. An anti-IL-12 neutralizing antibody prevented NO production and mortality in an LPS-induced inflammation mouse model in the presence of a MEK inhibitor. These results suggest that the MEK inhibitor increases the mortality rate in mice with LPS-induced inflammation through IL-12-NO signaling.

Intestinal barrier in inflammatory bowel disease: A bibliometric and knowledge-map analysis

BACKGROUND

Barrier surfaces composed of specialized epithelial cells separate the host body from the external environment, and are essential for maintaining proper intestinal physiologic and immune homeostasis.

AIM

To explore the development trends and research hotspots of intestinal barrier research in inflammatory bowel disease (IBD).

METHODS

The publications related to the intestinal barrier in IBD were obtained from the Web of Science Core Collection database. Bibliometric analysis and visualization were conducted using VOSviewer, CiteSpace and R software.

RESULTS

A total of 4482 articles published between 2002 and 2022 were identified. The United States is dominant in intestinal barrier research, whereas the University of Chicago is the most active institution. Jerrold from Harvard Medical School was the most productive authors with the most citations. The journals Inflammatory Bowel Disease and Gastroenterology have made significant contributions in this field. The keywords appearing at high frequency related to the intestinal barrier in IBD were detected, including nuclear factor kappa B, tumor necrosis factor-α, apoptosis, oxidative stress and probiotics. Among them, antioxidants, Akkermansia muciniphila, nanoparticles, short-chain fatty acids and extracellular vesicles have received growing interest in recent research.

CONCLUSION

The intestinal barrier field is developing rapidly with extensive cooperation. Targeting the gut microbiota and dietary metabolism to regulate the intestinal barrier has shown promising prospective applications and has generated broad interest. The importance of the intestinal barrier in IBD is gradually being fully recognized, providing a new therapeutic perspective for improving inflammation and prognosis.

Cardiovascular manifestations of inflammatory bowel diseases and the underlying pathogenic mechanisms

Inflammatory bowel disease (IBD), consisting of ulcerative colitis and Crohn's disease, mainly affects the gastrointestinal tract but is also known to have extraintestinal manifestations because of long-standing systemic inflammation. Several national cohort studies have found that IBD is an independent risk factor for the development of cardiovascular disorders. However, the molecular mechanisms by which IBD impairs the cardiovascular system are not fully understood. Although the gut-heart axis is attracting more attention in recent years, our knowledge of the organ-to-organ communication between the gut and the heart remains limited. In patients with IBD, upregulated inflammatory factors, altered microRNAs and lipid profiles, as well as dysbiotic gut microbiota, may induce adverse cardiac remodeling. In addition, patients with IBD have a three- to four times higher risk of developing thrombosis than people without IBD, and it is believed that the increased risk of thrombosis is largely due to increased procoagulant factors, platelet count/activity, and fibrinogen concentration, in addition to decreased anticoagulant factors. The predisposing factors for atherosclerosis are present in IBD and the possible mechanisms may involve oxidative stress system, overexpression of matrix metalloproteinases, and changes in vascular smooth muscle phenotype. This review focuses mainly on 1) the prevalence of cardiovascular diseases associated with IBD, 2) the potential pathogenic mechanisms of cardiovascular diseases in patients with IBD, and 3) adverse effects of IBD drugs on the cardiovascular system. Also, we introduce here a new paradigm for the gut-heart axis that includes exosomal microRNA and the gut microbiota as a cause for cardiac remodeling and fibrosis.

Bioactive glass in the treatment of ulcerative colitis to regulate the TLR4 / MyD88 / NF-κB pathway

Ulcerative colitis (UC) is a chronic and recurrent intestinal disease of unknown aetiology, and the few treatments approved for UC have serious side effects. In this study, a new type of uniformly monodispersed calcium-enhanced radial mesoporous micro-nano bioactive glass (HCa-MBG) was prepared for UC treatment. We established cellular and rat UC models to explore the effects and mechanism of HCa-MBG and traditional BGs (45S5, 58S) on UC. The results showed that BGs significantly reduced the cellular expression of several inflammatory factors, such as IL-1β, IL-6, TNF-α and NO. In the animal experiments, BGs were shown to repair the DSS-damaged colonic mucosa. Moreover, BGs downregulated the mRNA levels of the inflammatory factors IL-1β, IL-6, TNF-α and iNOS, which were stimulated by DSS. BGs were also found to manage the expression of key proteins in NF-kB signal pathway. However, HCa-MBG was more effective than traditional BGs in terms of improving UC clinical manifestations and reducing the expression of inflammatory factors in rats. This study confirmed for the first time that BGs can be used as an adjuvant drug in UC treatment, thereby preventing UC progression.

Diagnostic role of fractional exhaled nitric oxide in pediatric eosinophilic esophagitis, relationship with gastric and duodenal eosinophils

BACKGROUND

Eosinophilic esophagitis (EoE) is an eosinophilic-predominant inflammation of the esophagus diagnosed by upper endoscopy and biopsies. A non-invasive and cost-effective alternative for management of EoE is being researched. Previous studies assessing utility of fractional exhaled nitric oxide (FeNO) in EoE were low powered. None investigated the contribution of eosinophilic inflammation of the stomach and duodenum to FeNO.

AIM

To assess the utility of FeNO as a non-invasive biomarker of esophageal eosinophilic inflammation for monitoring disease activity.

METHODS

Patients aged 6-21 years undergoing scheduled upper endoscopy with biopsy for suspected EoE were recruited in our observational study. Patients on steroids and with persistent asthma requiring daily controller medication were excluded. FeNO measurements were obtained in duplicate using a chemiluminescence nitric oxide analyzer (NIOX MINO, Aerocrine, Inc.; Stockholm, Sweden) prior to endoscopy. Based on the esophageal peak eosinophil count (PEC)/high power field on biopsy, patients were classified as EoE (PEC ≥ 15) or control (PEC ≤ 14). Mean FeNO levels were correlated with presence or absence of EoE, eosinophil counts on esophageal biopsy, and abnormal downstream eosinophilia in the stomach (PEC ≥ 10) and duodenum (PEC ≥ 20). Wilcoxon rank-sum test, Spearman correlation, and logistic regression were used for analysis. P value < 0.05 was considered significant.

RESULTS

We recruited a total of 134 patients, of which 45 were diagnosed with EoE by histopathology. The median interquartile range FeNO level was 17 parts per billion (11-37, range: 7-81) in the EoE group and 12 parts per billion (8-19, range: 5-71) in the control group. After adjusting for atopic diseases, EoE patients had significantly higher FeNO levels as compared to patients without EoE (Z = 3.33, P < 0.001). A weak yet statistically significant positive association was found between the number of esophageal eosinophils and FeNO levels (r = 0.30, P < 0.005). On subgroup analysis within the EoE cohort, higher FeNO levels were noted in patients with abnormal gastric (n = 23, 18 vs 15) and duodenal eosinophilia (n = 28, 21 vs 14); however, the difference was not statistically significant.

CONCLUSION

After ruling out atopy as possible confounder, we found significantly higher FeNO levels in the EoE cohort than in the control group.

Over-production of exopolysaccharide by Lacticaseibacillus rhamnosus CNCM I-3690 strain cutbacks its beneficial effect on the host

Most lactobacilli produce extracellular polysaccharides that are considered to contribute to the probiotic effect of many strains. Lacticaseibacillus rhamnosus CNCM I-3690 is an anti-inflammatory strain able to counterbalance gut barrier dysfunction. In this study ten spontaneous variants of CNCM I-3690 with different EPS-production were generated and characterized by their ropy phenotype, the quantification of the secreted EPS and genetic analysis. Amongst them, two were further analysed in vitro and in vivo: an EPS over-producer (7292) and a low-producer derivative of 7292 (7358, with similar EPS levels than the wild type (WT) strain). Our results showed that 7292 does not have anti-inflammatory profile in vitro, and lost the capacity to adhere to the colonic epithelial cells as well as the protective effect on the permeability. Finally, 7292 lost the protective effects of the WT strain in a murine model of gut dysfunction. Notably, strain 7292 was unable to stimulate goblet cell mucus production and colonic IL-10 production, all key features for the beneficial effect of the WT strain. Furthermore, transcriptome analysis of colonic samples from 7292-treated mice showed a down-regulation of anti-inflammatory genes. Altogether, our results point out that the increase of EPS production in CNCM I-3690 impairs its protective effects and highlight the importance of the correct EPS synthesis for the beneficial effects of this strain.

Engineering fucoxanthin-loaded probiotics' membrane vesicles for the dietary intervention of colitis

Extracellular vesicles (EVs) are very attractive as carriers of active components due to their good immunological and their ability to penetrate the physiological barrier that synthetic delivery carriers cannot penetrate. However, the low secretion capacity of EVs limited its widespread adoption, let alone the lower yield of EVs loaded with active components. Here, we report a large-scale engineering preparation strategy of synthetic probiotic membrane vesicles for encapsulating fucoxanthin (FX-MVs), an intervention for colitis. Compared with the EVs naturally secreted by probiotics, the engineering membrane vesicles showed a 150-fold yield and richer protein. Moreover, FX-MVs improved the gastrointestinal stability of fucoxanthin and inhibited H₂O₂-induced oxidative damage by scavenging free radicals effectively (p < 0.05). The in vivo results showed that FX-MVs could promote the polarization of macrophages to M2 type, prevent the injury and shortening of colon tissue (p < 0.05), and improve the colonic inflammatory response. Consistently, proinflammatory cytokines were effectively suppressed after FX-MVs treatment (p < 0.05). Unexpectedly, such engineering FX-MVs could also reshape the gut microbiota communities and improve the abundance of short-chain fatty acids in the colon. This study lays a foundation for developing dietary interventions using natural foods to treat intestinal-related diseases.

Possible Curative Effects of Boric Acid and Bacillus clausii Treatments on TNBS-Induced Ulcerative Colitis in Rats

Crohn's disease (CD) and ulcerative colitis (UC) are two chronic relapsing inflammatory bowel diseases (IBD). Although there are several treatment options available to improve the symptoms of IBD patients, there is no effective treatment that provides a definitive solution. In the present study, we aim to investigate the antioxidative/anti-inflammatory effects of oral administration of boric acid and Bacillus clausii in a rat trinitrobenzenesulfonic acid (TNBS)-induced colitis model. The effects of boric acid and B. clausii were examined in serum and colon tissues with the help of some biochemical and histological analyses. Elevated inflammation and oxidative damage were found in the blood and colon tissue samples in the TNBS-induced group according to the complete blood count (CBC), tumor necrosis factor (TNF) alpha, interleukin-35 (IL-35), malondialdehyde (MDA), glutathione peroxidase (GPx), myeloperoxidase (MPO), nitric oxide (NO), and histological findings. Particularly, the highest IL-35 level (70.09 ± 12.62 ng/mL) in the combined treatment group, highest catalase activity (5322 ± 668.1 U/mg protein) in the TNBS-induced group, and lower relative expression of inducible nitric oxide synthase in the TNBS-induced group than the control group were striking findings. According to our results, it can be concluded that boric acid showed more curative effects, even if B. clausii probiotics was partially ameliorative.

Therapeutic potential of mesenchymal stem/stromal cells (MSCs)-based cell therapy for inflammatory bowel diseases (IBD) therapy

Recently, mesenchymal stem/stromal cells (MSCs) therapy has become an emerging therapeutic modality for the treatment of inflammatory bowel disease (IBD), given their immunoregulatory and pro-survival attributes. MSCs alleviate dysregulated inflammatory responses through the secretion of a myriad of anti-inflammatory mediators, such as interleukin 10 (IL-10), transforming growth factor-β (TGFβ), prostaglandin E2 (PGE2), tumor necrosis factor-stimulated gene-6 (TSG-6), etc. Indeed, MSC treatment of IBD is largely carried out through local microcirculation construction, colonization and repair, and immunomodulation, thus alleviating diseases severity. The clinical therapeutic efficacy relies on to the marked secretion of various secretory molecules from viable MSCs via paracrine mechanisms that are required for gut immuno-microbiota regulation and the proliferation and differentiation of surrounding cells like intestinal epithelial cells (IECs) and intestinal stem cells (ISCs). For example, MSCs can induce IECs proliferation and upregulate the expression of tight junction (TJs)-associated protein, ensuring intestinal barrier integrity. Concerning the encouraging results derived from animal studies, various clinical trials are conducted or ongoing to address the safety and efficacy of MSCs administration in IBD patients. Although the safety and short-term efficacy of MSCs administration have been evinced, the long-term efficacy of MSCs transplantation has not yet been verified. Herein, we have emphasized the illumination of the therapeutic capacity of MSCs therapy, including naïve MSCs, preconditioned MSCs, and also MSCs-derived exosomes, to alleviate IBD severity in experimental models. Also, a brief overview of published clinical trials in IBD patients has been delivered.

The Effect of Necrosis Inhibitor on Dextran Sulfate Sodium Induced Chronic Colitis Model in Mice

Uncontrolled chronic inflammation and necrosis is characteristic of inflammatory bowel disease (IBD). This study aimed to investigate the effect of necrosis inhibitor (NI, NecroX-7) on a dextran sulfate sodium (DSS) induced chronic colitis model of mice. DSS was administered on days 1-5, and the NI was administered intraperitoneally (3 mg/kg, 30 mg/kg) on days 1, 3, and 5 as well as every other day during the first five days of a three-week cycle. Three cycles of administration were performed. Colitis was evaluated based on the disease activity index (DAI) score, colon length, and histological score. Reverse transcription polymerase chain reaction testing, the Western blot assay, and immunohistochemical staining were performed to determine inflammatory cytokine levels. The NI reduced body weight change and the DAI score. Colon length and the histological score were longer and lower in the NI-treated groups, respectively. The NI decreased the expression of pro-inflammatory cytokines, particularly in tumor necrosis factor alpha (TNF-α) and phosphorylated nuclear factor kappa B (p-NF-κB). Immunohistochemical staining revealed decreased inducible nitric oxide synthase (iNOS) and high mobility group box 1 (HMGB1) levels. Overall, the NI improved DSS induced chronic colitis by attenuating the mRNA expression of pro-inflammatory cytokines such as TNF-α. Therefore, NI use is a potential, novel treatment approach for IBD.

Gluten-free diet affects fecal small non-coding RNA profiles and microbiome composition in celiac disease supporting a host-gut microbiota crosstalk

Current treatment for celiac disease (CD) is adhering to a gluten-free diet (GFD), although its long-term molecular effects are still undescribed. New molecular features detectable in stool may improve and facilitate noninvasive clinical management of CD. For this purpose, fecal small non-coding RNAs (sncRNAs) and gut microbiome profiles were concomitantly explored in CD subjects in relation to strict (or not) GFD adherence over time. In this observational study, we performed small RNA and shotgun metagenomic sequencing in stool from 63 treated CD (tCD) and 3 untreated subjects as well as 66 sex- and age-matched healthy controls. tCD included 51 individuals on strict GFD and with negative transglutaminase (TG) serology (tCD-TG-) and 12 symptomatic with not strict/short-time of GFD adherence and positive TG serology (tCD-TG+). Samples from additional 40 healthy adult individuals and a cohort of 19 untreated pediatric CD subjects and 19 sex/age matched controls were analyzed to further test the outcomes. Several miRNA and microbial profiles were altered in tCD subjects (adj. p < .05). Findings were validated in the external group of adult controls. In tCD-TG-, GFD duration correlated with five miRNA levels (p < .05): for miR-4533-3p and miR-2681-3p, the longer the diet adherence, the less the expression differed from controls. tCD-TG+ and untreated pediatric CD patients showed a similar miRNA dysregulation. Immune-response, trans-membrane transport and cell death pathways were enriched in targets of identified miRNAs. Bifidobacterium longum, Ruminococcus bicirculans, and Haemophilus parainfluenzae abundances shifted (adj. p < .05) with a progressive reduction of denitrification pathways with GFD length. Integrative analysis highlighted 121 miRNA-bacterial relationships (adj. p < .05). Specific molecular patterns in stool characterize CD subjects, reflecting either the long-term GFD effects or the gut inflammatory status, in case of a not strict/short-time adherence. Our findings suggest novel host-microbial interplays and could help the discovery of biomarkers for GFD monitoring over time.

TDAG51 deficiency attenuates dextran sulfate sodium-induced colitis in mice

Inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease, is a group of chronic inflammatory diseases of the gastrointestinal tract. Although the multifactorial etiology of IBD pathogenesis is relatively well documented, the regulatory factors that confer a risk of IBD pathogenesis remain less explored. In this study, we report that T-cell death-associated gene 51 (TDAG51/PHLDA1) is a novel regulator of the development of dextran sulfate sodium (DSS)-induced colitis in mice. TDAG51 expression was elevated in the colon tissues of DSS-induced experimental colitis mice. TDAG51 deficiency protected mice against acute DSS-induced lethality and body weight changes and disease severity. DSS-induced structural damage and mucus secretion in colon tissues were significantly reduced in TDAG51-deficient mice compared with wild-type mice. We observed similar results in a DSS-induced chronic colitis mouse model. Finally, we showed that the production of inflammatory mediators, including proinflammatory enzymes, molecules and cytokines, was decreased in DSS-treated TDAG51-deficient mice compared with DSS-treated wild-type mice. Thus, we demonstrated that TDAG51 deficiency plays a protective role against DSS-induced colitis by decreasing the production of inflammatory mediators in mice. These findings suggest that TDAG51 is a novel regulator of the development of DSS-induced colitis and is a potential therapeutic target for IBD.

What Is the Relationship between Antioxidant Efficacy, Functional Composition, and Genetic Characteristics in Comparing Soybean Resources by Year?

The aim of this study was to analyze the physiological activity of 48 soybean resources harvested in 2020 to identify the soybean resources’ relationships with individual isoflavone compounds and their genetic properties. These data will subsequently be compared with the research results on soybeans harvested in 2019. Initially, with respect to the physiological activity (6 types) and substances (19 types), this study evaluated the differences between the cultivation year (two years), seed coat color (three colors), and the interaction of the year and seed coat color of soybeans through ANOVA. Among the physiological activities, there were differences in the estrogen, estrogen receptor alpha, and UCP-1 (uncoupling protein-1) activities depending on the cultivation year. Moreover, there were differences in NO (nitric oxide), revealing differences in the ABTS (2, 2′-azino-bis-3ethylbenzo-thiazoline-6-sulfonic acid) and DPPH (2, 2-diphenyl-2-picrylhydrazyl) radical scavenging activities due to the seed coat color and the interaction of the year and seed coat color. Soybeans harvested in 2020 exhibited increased ABTS, DPPH, and NO inhibitory activities and reduced estrogen, estrogen receptor alpha, and UCP-1 activities compared to those harvested in 2019. According to the ANOVA results, eight of the nineteen individual derivatives illustrated yearly differences, while three derivatives displayed differences due to the seed coat color. Secondly, according to the relationship between the efficacy, derivative substances, and genetic properties, it was determined that genistein 7-O-(2″-O-apiosyl)glucoside (F5) is the individual isoflavone derivative that affected the six types of physiological activity, on which the genome-wide association study (GWAS) showed no significant differences for genetic properties. These results were inconsistent with the 2019 data, where three types of individual compounds, including F5, were proposed as substances that correlated with efficacy and there was a high correlation with genetic properties. Therefore, this study selected B17, B23, B15, B24, and Y7 as excellent varieties that are stable and highly functional in the cultivation environment, producing only small annual differences. The results of this study will be utilized as basic data for predicting soybean varieties and their cultivation, which have high environmental stability under climate variation and properly retain the functional substances and efficacy.

Jatrorrhizine alleviates ulcerative colitis via regulating gut microbiota and NOS2 expression

Background

The natural protoberberine jatrorrhizine (JA) is reported to have several medicinal properties and a significant effect on the gut microbiota of mice. The regulation of gut microbiota is generally known to play an important role in the intestinal mucosal immune response to ulcerative colitis (UC). However, whether JA can be used in the treatment of UC is still unclear. Our study aimed to investigate the underlying therapeutic effects and mechanisms of JA in treating colitis.

Results

Compared with the DSS-induced colitis model group, the JA + DSS treated group had more significant improvements in weight loss, disease activity index score, colon length shortening, and pathological inflammation. 16s rRNA sequencing analysis showed that JA treatment protected colitis mice against DSS-induced disturbance of gut microbiota. At the phylum level, reductions in Deferribacteres and Proteobacteria were observed in the JA-treated group; At the genus level, the JA-treated group showed an increased relative abundance of Akkermansia and decreased abundance of Escherichia-Shigella, Desulfovibrio, Mucispirillum, etc. Network pharmacology was then used to screen out five drug-disease target genes (NOS2, ESR1, CALM1, CALM2, CALM3). Transcriptomics analysis further validated that the NOS2 expression was significantly reduced in colon tissue of JA-administered mice compared with DSS control mice. Additionally, analysis of correlation suggested that NOS2 expression was negatively correlated with the relative abundance of AKKermansia and positively correlated with Desulfovibrio, Rikenella.

Conclusion

JA alleviates ulcerative colitis via regulating gut microbiota and NOS2 expression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13099-022-00514-z.

The Multiple Faces of Nitric Oxide in Chronic Granulomatous Disease: A Comprehensive Update

Nitric oxide (NO), a signaling molecule, regulates multiple biological functions, including a variety of physiological and pathological processes. In this regard, NO participates in cutaneous inflammations, modulation of mitochondrial functions, vascular diseases, COVID-19, neurologic diseases, and obesity. It also mediates changes in the skeletal muscle function. Chronic granulomatous disease (CGD) is a primary immunodeficiency disorder characterized by the malfunction of phagocytes caused by mutations in some of the genes encoding subunits of the superoxide-generating phagocyte NADPH (NOX). The literature consulted shows that there is a relationship between the production of NO and the NADPH oxidase system, which regulates the persistence of NO in the medium. Nevertheless, the underlying mechanisms of the effects of NO on CGD remain unknown. In this paper, we briefly review the regulatory role of NO in CGD and its potential underlying mechanisms.

Accidental lead in contaminated pipe-borne water and dietary furan intake perturbs rats' hepatorenal function altering oxidative, inflammatory, and apoptotic balance

Inadvertent exposure to furan and Pb is associated with hepatorenal abnormalities in humans and animals. It is perceived that these two chemical species may work in synergy to orchestrate liver and kidney damage. Against this background, we investigated the combined effect of furan and incremental lead (Pb) exposure on hepatorenal dysfunction. Wistar rats (n = 30; 150 g) were treated for 28 days accordingly: Control; FUR (8 mg/kg), PbAc (100 µg/L), FUR + PbAc₁ (8 mg/kg FUR + 1 µg/L PbAc); FUR + PbAc₁ (8 mg/kg FUR + 10 µg/L PbAc), and FUR + PbAc₁ (8 mg/kg FUR + 100 µg/L PbAc). Biomarkers of hepatorenal function, oxidative stress, inflammation, DNA damage, and apoptosis were examined. Furan and incrementally Pb exposure increased the levels of hepatorenal biomarkers and oxidative and pro-inflammatory mediators, including lipid peroxidation, reactive oxygen and nitrogen species, and interleukin-1 beta. Increased DNA damage, caspases- 9 and -3, and atypical histoarchitecture of the hepatorenal tissues exemplified furan and Pb treatment-related perturbations. Furthermore, the levels of antioxidants and IL-10 were also suppressed. Furan and Pb dose-dependently exacerbated hepatorenal derangements by altering the redox and inflammatory rheostats, worsened DNA damage, and related apoptotic onset that may potentiate hepatorenal disorders in humans and animals. The findings validate the synergistic effect of furan and Pb in the pathophysiology of kidney and liver disorders.

Arginine metabolism regulates the pathogenesis of inflammatory bowel disease

The pathogenesis of inflammatory bowel disease (IBD) is related to genetic susceptibility, enteric dysbiosis, and uncontrolled, chronic inflammatory responses that lead to colonic tissue damage and impaired intestinal absorption. As a consequence, patients with IBD are prone to nutrition deficits after each episode of disease resurgence. Nutritional supplementation, especially for protein components, is often implemented during the remission phase of IBD. Notably, ingested nutrients could affect the progression of IBD and the prognostic outcome of patients; therefore, they should be cautiously evaluated prior to being used for IBD intervention. Arginine (Arg) is a semi-essential amino acid required for protein synthesis and intimately associated with gut pathophysiology. To help optimize arginine-based nutritional intervention strategies, the present work summarizes that during the process of IBD, patients manifest colonic Arg deficiency and the turbulence of Arg metabolic pathways. The roles of Arg–nitric oxide (catalyzed by inducible nitric oxide synthase) and Arg–urea (catalyzed by arginases) pathways in IBD are debatable; the Arg–polyamine and Arg–creatine pathways are mainly protective. Overall, supplementation with Arg is a promising therapeutic strategy for IBD; however, the dosage of Arg may need to be carefully tailored for different individuals at different disease stages. Additionally, the combination of Arg supplementation with inhibitors of Arg metabolic pathways as well as other treatment options is worthy of further exploration.

Influence and Implications of the Molecular Paradigm of Nitric Oxide Underlying Inflammatory Reactions of the Gastrointestinal Tract of Dog: A Major Hallmark of Inflammatory Bowel Disease

Nitric oxide (NO), a pleiotropic free radical messenger molecule, is responsible for the various cellular function of the gastrointestinal mucosa. It plays a major role in the maintenance of perfusion, regulation of microvascular, epithelial permeability, and immune functions. Nitric oxide exerts its beneficial effect on the initiation and maintenance of inflammation in human inflammatory bowel disease (IBD). But the accelerated production of NO triggers activation of the inducible form of the NO synthase enzyme (iNOS) that leads to damages of the intestinal membrane. Nitric oxide synthase enzyme is responsible for the higher production of NO from l-arginine and causes an inflammatory condition in the intestinal epithelium. Nitric oxide induces nitrative DNA damage and oxidative DNA damage in the cellular system. Accelerated production of NO enhances iNOS activity that is associated with cytotoxicity and apoptosis of gastrointestinal epithelial cells in the dog. Chronic inflammation leads to angiogenesis that is modulated by the immune system in IBD. Chronic inflammation is a major risk factor for the development of gastrointestinal malignancies. Nitric oxide participates in mucosal inflammation in the intestine through invigoration of NO synthase enzyme. The intrinsic complex mechanism is correlated with the inflammation in the gastrointestinal tract and is also correlated with the expression of iNOS, enzymatic activity and NO production. Nitric oxide employs a significant role in modulating epithelial permeability with accelerated immune response in acute colitis. But the enormous generation of NO causes adverse effects on the mucosal cell during the inflammatory process in IBD. In this review, a complex episode of NO generation with altered biochemical pathways was assessed for the regulation of mucosal inflammation in inflammatory bowel disease of dogs. This review is a unique compilation of the role of NO in the pathogenesis of inflammatory bowel disease of dogs. Nitric oxide plays a key role in modulating cancer in the gastrointestinal tract. This review seeks to explore the characteristics of NO as a major hallmark of canine inflammatory bowel diseases.

Inverse and Concordant Mucosal Pathway Gene Expressions in Inflamed and Non-Inflamed Ulcerative Colitis Patients: Potential Relevance to Aetiology and Pathogenesis

Ulcerative colitis (UC) arises from a complex interplay between host and environmental factors, but with a largely unsolved pathophysiology. The pathophysiology was outlined by RNA-sequencing of mucosal biopsies from non-inflamed and inflamed colon of UC patients (14 and 17, respectively), and from 27 patients without intestinal inflammation. Genes differentially expressed (DE), or present in enriched gene sets, were investigated using statistical text analysis of functional protein information. Compared with controls, inflamed and non-inflamed UC mucosa displayed 9360 and 52 DE genes, respectively. Seventy-three non-pseudogenes were DE relative to both gender and inflammation. Mitochondrial processes were downregulated in inflamed and upregulated in non-inflamed UC mucosa, whereas angiogenesis and endoplasmic reticulum (ER) stress were upregulated in both tissue states. Immune responses were upregulated in inflamed mucosa, whereas the non-inflamed UC mucosa presented both up- and downregulated gene sets. DE and enriched genes overlapped with genes present in inflammatory bowel disease genome-wide associated loci (p = 1.43 × 10⁻¹⁸), especially regarding immune responses, respiratory chain, angiogenesis, ER stress, and steroid hormone metabolism. Apart from confirming established pathophysiological mechanisms of immune cells, our study provides evidence for involvement of less described pathways (e.g., respiratory chain, ER stress, fatty-acid oxidation, steroid hormone metabolism and angiogenesis).

Loss of MMR and TGFBR2 Increases the Susceptibility to Microbiota-Dependent Inflammation-Associated Colon Cancer

BACKGROUND AND AIMS

Mutations in DNA mismatch repair (MMR) genes are causative in Lynch syndrome and a significant proportion of sporadic colorectal cancers (CRCs). MMR-deficient (dMMR) CRCs display increased mutation rates, with mutations frequently accumulating at short repetitive DNA sequences throughout the genome (microsatellite instability). The TGFBR2 gene is one of the most frequently mutated genes in dMMR CRCs. Therefore, we generated an animal model to study how the loss of both TGFBR2 signaling impacts dMMR-driven intestinal tumorigenesis in vivo and explore the impact of the gut microbiota.

METHODS

We generated VCMsh2/Tgfbr2 mice in which Msh2loxP and Tgfbr2loxP alleles are inactivated by Villin-Cre recombinase in the intestinal epithelium. VCMsh2/Tgfbr2 mice were analyzed for their rate of intestinal cancer development and for the mutational spectra and gene expression profiles of tumors. In addition, we assessed the impact of chemically induced chronic inflammation and gut microbiota composition on colorectal tumorigenesis.

RESULTS

VCMsh2/Tgfbr2 mice developed small intestinal adenocarcinomas and CRCs with histopathological features highly similar to CRCs in Lynch syndrome patients. The CRCs in VCMsh2/Tgfbr2 mice were associated with the presence of colitis and displayed genetic and histological features that resembled inflammation-associated CRCs in human patients. The development of CRCs in VCMsh2/Tgfbr2 mice was strongly modulated by the gut microbiota composition, which in turn was impacted by the TGFBR2 status of the tumors.

CONCLUSIONS

Our results demonstrate a synergistic interaction between MMR and TGFBR2 inactivation in inflammation-associated colon tumorigenesis and highlight the crucial impact of the gut microbiota on modulating the incidence of inflammation-associated CRCs.

Psychological stress disrupts intestinal epithelial cell function and mucosal integrity through microbe and host-directed processes

Psychological stress alters the gut microbiota and predisposes individuals to increased risk for enteric infections and chronic bowel conditions. Intestinal epithelial cells (IECs) are responsible for maintaining homeostatic interactions between the gut microbiota and its host. In this study, we hypothesized that disruption to colonic IECs is a key factor underlying stress-induced disturbances to intestinal homeostasis. Conventionally raised (CONV-R) and germ-free (GF) mice were exposed to a social disruption stressor (Str) to ascertain how stress modifies colonic IECs, the mucosal layer, and the gut microbiota. RNA sequencing of IECs isolated from CONV-R mice revealed a robust pro-inflammatory (Saa1, Il18), pro-oxidative (Duox2, Nos2), and antimicrobial (Reg3b/g) transcriptional profile as a result of Str. This response occurred concomitant to mucus layer thinning and signs of microbial translocation. In contrast to their CONV-R counterparts, IECs from GF mice or mice treated with broad spectrum antibiotics exhibited no detectable transcriptional changes in response to Str. Nevertheless, IECs from Str-exposed GF mice exhibited an altered response to ex vivo bacterial challenge (increased dual Oxidase-2 [Duox2] and nitric oxide synthase-2 (Nos2)), indicating that STR primes host IEC pro-oxidative responses. In CONV-R mice stress-induced increases in colonic Duox2 and Nos2 (ROS generating enzymes) strongly paralleled changes to microbiome composition and function, evidencing Str-mediated ROS production as a primary factor mediating gut-microbiota dysbiosis. In conclusion, a mouse model of social stress disrupts colonic epithelial and mucosal integrity, a response dependent on an intact microbiota and host stress signals. Together these preclinical findings may provide new insight into mechanisms of stress-associated bowel pathologies in humans.

Aloe vera gel attenuates acetic acid-induced ulcerative colitis in adult male Wistar rats

Ulcerative colitis is a disease of undetermined etiology and treatment. It affects the colon and rectum and typically involves the mucosa, manifesting as continuous areas of inflammation and ulceration. Aloe gel contains more than a hundred potentially active constituents of different classes. This study investigated the effect of aloe gel on experimentally-induced ulcerative colitis. Male Wistar rats were randomly allocated into groups A to F of six rats each. Ulcerative colitis was induced to rats in groups B to F by single intra-colonic administration of 2 mL of 4% acetic acid with a size 6F pediatrics catheter. In contrast, group A received an equivalent volume of normal saline by the same route. Twenty-four hours after induction, rats in groups B and C received normal saline and 1 mg/kg b. wt. daily dose of dexamethasone, respectively. In contrast, those in groups D, E, and F received 20, 40, and 60 mg/kg b. wt. doses of aloe gel, respectively, for 14 days. They were sacrificed 24 h after the last administration. We assessed disease progression by determining the clinical activity index, gross inflammation, histological alterations, the intensity of DNA in colon cells, and tissue level of nitric oxide. All the parameters but one increased significantly in group B rats. The quantitative distribution of DNA in colon cells reduced significantly in this group. Aloe gel doses significantly reversed these changes in a dose-dependent manner. Dexamethasone showed lesser efficacy relative to 60 mg dose of the Aloe gel extract. We conclude that Aloe vera gel has therapeutic potential in the treatment and management of ulcerative colitis. The most significant effects were observed in the groups treated with the highest dose of Aloe gel (60 mg/kg b. wt.). It is also worth noting that the remediated potential of aloe gel in acetic acid-induced UC surpasses that of dexamethasone.

A potent HNF4α agonist reveals that HNF4α controls genes important in inflammatory bowel disease and Paneth cells

HNF4α has been implicated in IBD through a number of genome-wide association studies. Recently, we developed potent HNF4α agonists, including N-trans caffeoyltyramine (NCT). NCT was identified by structural similarity to previously the previously identified but weak HNF4α agonists alverine and benfluorex. Here, we administered NCT to mice fed a high fat diet, with the goal of studying the role of HNF4α in obesity-related diseases. Intestines from NCT-treated mice were examined by RNA-seq to determine the role of HNF4α in that organ. Surprisingly, the major classes of genes altered by HNF4α were involved in IBD and Paneth cell biology. Multiple genes downregulated in IBD were induced by NCT. Paneth cells identified by lysozyme expression were reduced in high fat fed mice. NCT reversed the effect of high fat diet on Paneth cells, with multiple markers being induced, including a number of defensins, which are critical for Paneth cell function and intestinal barrier integrity. NCT upregulated genes that play important role in IBD and that are downregulated in that disease. It reversed the loss of Paneth cell markers that occurred in high fat diet fed mice. These data suggest that HNF4α could be a therapeutic target for IBD and that the agonists that we have identified could be candidate therapeutics.

In Vitro Protective Effects of a Standardized Extract From Cynara Cardunculus L. Leaves Against TNF-α-Induced Intestinal Inflammation

Inflammatory bowel disease (IBD) represents a group of progressive disorders characterized by recurrent chronic inflammation of the gut. New unconventional therapies based on plant derived compounds capable of preventing and/or reducing acute or chronic inflammation could represent a valid alternative for the treatment or prevention of IBDs. Cynara cardunculus L. leaves, considered a food-waste suitable as a rich source of bioactive polyphenols including luteolin and chlorogenic acid, has been reported for its positive effects in digestive tract. The aim of the present work was to evaluate the in vitro molecular mechanisms of beneficial effects of a standardized polyphenol-rich extract obtained from the leaves of Cynara cardunculus L (CCLE) against acute intestinal inflammation induced by TNF-α on intestinal epithelial Caco-2 cells. CCLE prevented TNF-α-induced NF-κB inflammatory pathway and the overexpression of IL-8 and COX-2. In addition, CCLE was able to improve basal intracellular antioxidant power in both TNF-α-unexposed or -exposed Caco-2 cells and this effect was associated to the activation of Nrf2 pathway, a master regulator of redox homeostasis affecting antioxidant and phase II detoxifying genes, stimulating an adaptive cellular response. In conclusion, our data clearly evidenced that, although considered a waste, Cynara cardunculus leaves may be used to obtain extracts rich in bioactive polyphenols potentially useful for prevention and treatment of inflammatory intestinal diseases.

Redox-dependent internalization of the purinergic P2Y6 receptor limits colitis progression

[Figure: see text].

Efficacy of a functional food ingredient from Ensete superbum Roxb Cheesman peel in reducing the severity of ulcerative colitis in murine model

Ulcerative colitis is a recurrent inflammatory illness of the colon with an elevated risk of developing colon cancer. The drugs presently used to treat UC cause adverse effects and are...

Potential Implications of Citrulline and Quercetin on Gut Functioning of Monogastric Animals and Humans: A Comprehensive Review

The importance of gut health in animal welfare and wellbeing is undisputable. The intestinal microbiota plays an essential role in the metabolic, nutritional, physiological, and immunological processes of animals. Therefore, the rapid development of dietary supplements to improve gut functions and homeostasis is imminent. Recent studies have uncovered the beneficial effects of dietary supplements on the immune response, microbiota, gut homeostasis, and intestinal health. The application of citrulline (a functional gut biomarker) and quercetin (a known potent flavonoid) to promote gut functions has gained considerable interest as both bioactive substances possess anti-inflammatory, anti-oxidative, and immunomodulatory properties. Research has demonstrated that both citrulline and quercetin can mediate gut activities by combating disruptions to the intestinal integrity and alterations to the gut microbiota. In addition, citrulline and quercetin play crucial roles in maintaining intestinal immune tolerance and gut health. However, the synergistic benefits which these dietary supplements (citrulline and quercetin) may afford to simultaneously promote gut functions remain to be explored. Therefore, this review summarizes the modulatory effects of citrulline and quercetin on the intestinal integrity and gut microbiota, and further expounds on their potential synergistic roles to attenuate intestinal inflammation and promote gut health.

Jellyfish skin polysaccharides enhance intestinal barrier function and modulate the gut microbiota in mice with DSS-induced colitis

Jellyfish skin polysaccharides (JSP) were isolated from Rhopilema esculentum Kishinouye and contained 55.11% polysaccharides and 2.26% uronic acid. To examine the anti-inflammatory, antioxidant and immunomodulatory activities of JSP in vivo, C57BL/6 mice were induced to develop ulcerative colitis by dextran sulfate sodium (DSS) and the roles of dietary JSP supplementation in modulating colitis were explored. JSP supplementation reduced the symptoms of colitis in mice, increased colon length, protected goblet cells, and improved intestinal epithelial integrity and permeability. JSP modulated oxidative stress and inflammatory responses, which was demonstrated by reduced MPO activity, NO level, and levels of pro-inflammatory cytokines including TNF-α, IL-1β and IL-6 in mice. JSP suppressed NF-κB signaling pathways as evidenced by lower levels of phosphorylated p65 and IKB. Moreover, JSP supplementation enhanced the expression of tight junction proteins and mucins, and modulated the composition of the gut microbiota and the production of short-chain fatty acids. Taken together, these results reveal the anti-inflammatory effect of dietary JSP in vivo, suggesting the potential of JSP as a nutritional supplement or adjunct strategy in preventing or ameliorating colitis.

Otilonium Bromide treatment prevents nitrergic functional and morphological changes caused by chronic stress in the distal colon of a rat IBS model

Irritable bowel syndrome (IBS) is a highly prevalent gastrointestinal disorder characterized by periods of remission and exacerbation. Among the risk factors to develop IBS, psychosocial stress is widely acknowledged. The water avoidance stress repeatedly applied (rWAS) is considered effective to study IBS etio-pathogenesis. Otilonium bromide (OB), a drug with multiple mechanisms of action, is largely used to treat IBS patients. Orally administered, it concentrates in the large bowel and significantly ameliorates the IBS symptomatology. Presently, we tested whether rWAS rats developed neuro-muscular abnormalities in the distal colon and whether OB treatment prevented them. The investigation was focussed on the nitrergic neurotransmission by combining functional and morphological methodologies. The results confirm rWAS as reliable animal model to investigate the cellular mechanisms responsible for IBS: exposure to one-hour psychosocial stress for 10 days depressed muscle contractility and increased iNOS expression in myenteric neurons. OB treatment counteracted these effects. We hypothesize that these effects are due to the corticotropin-releasing factor (CRF) release, the main mediator of the psychosocial stress, followed by a CRF1receptor activation. OB, that was shown to prevent CRF1r activation, reasonably interrupted the cascade events that bring to the mechanical and immunohistochemical changes affecting rWAS rat colon.

Dr. NO and Mr. Toxic - the versatile role of nitric oxide

Nitric oxide (NO) is present in various organisms from humans, to plants, fungus and bacteria. NO is a fundamental signaling molecule implicated in major cellular functions. The role of NO ranges from an essential molecule to a potent mediator of cellular damages. The ability of NO to react with a broad range of biomolecules allows on one hand its regulation and a gradient concentration and on the other hand to exert physiological as well as pathological functions. In humans, NO is implicated in cardiovascular homeostasis, neurotransmission and immunity. However, NO can also contribute to cardiovascular diseases (CVDs) or septic shock. For certain denitrifying bacteria, NO is part of their metabolism as a required intermediate of the nitrogen cycle. However, for other bacteria, NO is toxic and harmful. To survive, those bacteria have developed processes to resist this toxic effect and persist inside their host. NO also contributes to maintain the host/microbiota homeostasis. But little is known about the impact of NO produced during prolonged inflammation on microbiota integrity, and some pathogenic bacteria take advantage of the NO response to colonize the gut over the microbiota. Taken together, depending on the environmental context (prolonged production, gradient concentration, presence of partners for interaction, presence of oxygen, etc.), NO will exert its beneficial or detrimental function. In this review, we highlight the dual role of NO for humans, pathogenic bacteria and microbiota, and the mechanisms used by each organism to produce, use or resist NO.

Anti-Inflammatory Effects of a Polyphenol, Catechin-7,4'-O-Digallate, from Woodfordia uniflora by Regulating NF-κB Signaling Pathway in Mouse Macrophages

Inflammation is a defense mechanism that protects the body from infections. However, chronic inflammation causes damage to body tissues. Thus, controlling inflammation and investigating anti-inflammatory mechanisms are keys to preventing and treating inflammatory diseases, such as sepsis and rheumatoid arthritis. In continuation with our work related to the discovery of bioactive natural products, a polyphenol, catechin-7,4′-O-digallate (CDG), was isolated from Woodfordia uniflora, which has been used as a sedative and remedy for skin infections in the Dhofar region of Oman. Thus far, no study has reported the anti-inflammatory compounds derived from W. uniflora and the mechanisms underlying their action. To investigate the effects of CDG on the regulation of inflammation, we measured the reduction in nitric oxide (NO) production following CDG treatment in immortalized mouse Kupffer cells (ImKCs). CDG treatment inhibited NO production through the downregulation of inducible nitric oxide synthase expression in lipopolysaccharide (LPS)-stimulated ImKCs. The anti-inflammatory effects of CDG were mediated via the inhibition of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation, an important inflammatory-response-associated signaling pathway. Moreover, CDG treatment has regulated the expression of pro-inflammatory cytokines, such as IL-6 and IL-1β. These results suggested the anti-inflammatory action of CDG in LPS-stimulated ImKCs.

Hecogenin and fluticasone combination attenuates TNBS-induced ulcerative colitis in rats via downregulation of pro-inflammatory mediators and oxidative stress

OBJECTIVE

Ulcerative colitis is common types of severe, progressive, idiopathic inflammatory bowel disease that involves the mucosal lining of the large intestine. The purpose of the study is to explore the effects of hecogenin in TNBS (2, 4, 6- trinitrobenzene sulfonic acid) induced ulcerative colitis model in rats.

MATERIAL AND METHODS

Thirty Wistar rats were randomized into five groups: (i) Normal Control (NC), (ii) Disease Control (DC), (iii) Hecogenin (HG) (50 µg/rat), (iv) Fluticasone (FC) (50 µg/rat), (v) Hecogenin + Fluticasone (HG + FC) combination (25 µg/rat). Colitis was induced by trans-rectal administration of TNBS using a catheter inserted 8 cm into the rectal portion of the rat. Colitis was evaluated by an independent observer who was blinded to the treatment. All treatment group results were compared to the TNBS group results.

RESULTS

The study results revealed that treatment of rats with HG and HG + FC significantly improved the body weight and colon length whereas; decreased the spleen weight, colon weight/length ratio, macroscopic lesions score, diarrhea score and adhesion score. The drug treatment in rats substantially decreased the development of inflammatory cytokines, levels of serum immunoglobulin E, colonic nitric oxide contents and restoration of antioxidant stress markers. Histopathological colon sample study significantly reduced colonic inflammation with a substantial decrease in inflammation score.

CONCLUSION

Thus, HG and HG + FC combination could change the pathogenesis of the disease and may be a potential therapeutic target for the treatment of ulcerative colitis by a reduction in dose in conjunction with FC to prevent the persistent adverse effects associated with FC.