Oxidative Stress Markers in Inflammatory Bowel Diseases: Systematic Review

Comparison of novel native probiotics and paraprobiotics in modulating oxidative stress and inflammation in DSS-induced colitis: implications for enhanced therapeutic strategies in high fat diet

AIM

IBD is a condition that may result from the presence of oxidative stress. The objective of this research is to evaluate and compare the potency of probiotics and paraprobiotics to modulate oxidative stress and inflammation.

METHODS AND RESULTS

In the initial phase, the antioxidant capabilities of 88 strains from Lactobacillus and Bifidobacterium were evaluated. In the subsequent phase, during the in-vivo stage, four experimental groups were established, consisting of a high-fat diet (HFD) + PBS, HFD + DSS, HFD + DSS + 10^9 cfu/ml of 6 selected native probiotic, and HFD + DSS + 10^9 cfu/ml of paraprobiotic (from 6 selected strains), with male wild-type C57BL/6 mice being assigned to these groups. The phenotypical indices and pathological scores along with the evaluation of the expression of genes associated with the NF-kB and Nrf2 signaling pathways, as well as enzymes linked to oxidant/anti-oxidant activities, and proinflammatory/inflammatory cytokines were performed. A significant difference was noted among the groups exposed to DSS and groups that given our native agents. The mice receiving a blend of probiotics and paraprobiotics alongside DSS demonstrated a mitigation of the harmful impacts caused by DSS, both regarding phenotypic traits, including pathological scores and also the level of cytokines and antioxidant markers and also molecular indicators like the Nrf2 and NF-kB associated genes. Also, there was no notable difference between our native probiotic and paraprobiotic.

CONCLUSION

The study's findings provide evidence that the expression of inflammation can be successfully alleviated by utilizing our native probiotics and paraprobiotics, with a greater emphasis on the latter due to its inherent safety.

IMPACT STATEMENTS

This study highlighted the anti-inflammatory and antioxidant properties of probiotic and paraprobiotic that could be useful for patients with inflammatory status.

A Paper-Based Assay for the Determination of Total Antioxidant Capacity in Human Serum Samples

Determining the total antioxidant capacity (TAC) of biological samples is a valuable approach to measuring health status under oxidative stress conditions, such as infertility and type 2 diabetes. The Trolox equivalent antioxidant capacity (TEAC) assay is the most common approach to evaluating TAC in biological matrices. This assay is typically performed in clinical settings on a microtiter plate using a plate reader. However, the instrumentation and expertise requirements, and the resulting delay in the reporting of assay outcomes, make solution-based TEAC assays impractical for point-of-care or at-home testing, where individuals may want to monitor their health status during treatment. This work introduces the first microfluidic paper-based analytical device (µPAD) that measures TAC in human serum using TEAC assay chemistry. TAC was determined through a colorimetric image analysis of the degree of decolorization of 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cations (ABTS●+) by serum antioxidants. The µPAD showed a linear response to Trolox, ranging from 0.44 to 2.4 mM, (r  =  0.999). The performance of paper-based TEAC assays was validated through direct comparison to solution-based TEAC assays. There was a 0.04 mM difference in TAC values between the two platforms, well within one standard deviation of a standard solution-based assay conducted on an aliquot of the same serum sample (±0.25 mM). The µPAD had a limit of detection (LOD) of 0.20 mM, well below the TAC of normal human serum. The results suggest that the proposed device can be used for biological TAC determination and expands the field of TAC analysis in point-of-care health monitoring.

Antioxidant Therapy in Inflammatory Bowel Diseases: How Far Have We Come and How Close Are We?

Inflammatory bowel diseases (IBD) pose a growing public health challenge with unclear etiology and limited efficacy of traditional pharmacological treatments. Alternative therapies, particularly antioxidants, have gained scientific interest. This systematic review analyzed studies from MEDLINE, Cochrane, Web of Science, EMBASE, and Scopus using keywords like "Inflammatory Bowel Diseases" and "Antioxidants." Initially, 925 publications were identified, and after applying inclusion/exclusion criteria-covering studies from July 2015 to June 2024 using murine models or clinical trials in humans and evaluating natural or synthetic substances affecting oxidative stress markers-368 articles were included. This comprised 344 animal studies and 24 human studies. The most investigated antioxidants were polyphenols and active compounds from medicinal plants (n = 242; 70.3%). The review found a strong link between oxidative stress and inflammation in IBD, especially in studies on nuclear factor kappa B and nuclear factor erythroid 2-related factor 2 pathways. However, it remains unclear whether inflammation or oxidative stress occurs first in IBD. Lipid peroxidation was the most studied oxidative damage, followed by DNA damage. Protein damage was rarely investigated. The relationship between antioxidants and the gut microbiota was examined in 103 animal studies. Human studies evaluating oxidative stress markers were scarce, reflecting a major research gap in IBD treatment. PROSPERO registration: CDR42022335357 and CRD42022304540.

Oxidative stress-related biomarkers as promising indicators of inflammatory bowel disease activity: A systematic review and meta-analysis

Oxidative stress is believed to play an important role in the pathogenesis of inflammatory bowel disease (IBD), specifically Crohn's disease (CD) and ulcerative colitis (UC). This meta-analysis aimed to identify and quantify the oxidative stress-related biomarkers in IBD and their associations with disease activity. We systematically searched Ovid MEDLINE, Ovid Embase, and Web of Science databases, identifying 54 studies for inclusion. Comparisons included: (i) active IBD versus healthy controls; (ii) inactive IBD versus healthy controls; (iii) active CD versus inactive CD; and (iv) active UC versus inactive UC. Our analysis revealed a significant accumulation of biomarkers of oxidative damage to biomacromolecules, coupled with reductions in various antioxidants, in both patients with active and inactive IBD compared to healthy controls. Additionally, we identified biomarkers that differentiate between active and inactive CD, including malondialdehyde, Paraoxonase 1, catalase, albumin, transferrin, and total antioxidant capacity. Similarly, levels of Paraoxonase 1, erythrocyte glutathione peroxidase, catalase, albumin, transferrin, and free thiols differed between active and inactive UC. Vitamins and carotenoids also emerged as potential disease activity biomarkers for CD and UC, but their intake should be monitored to obtain meaningful results. These findings emphasize the involvement of oxidative stress in the pathogenesis of IBD and highlight the potential of oxidative stress-related biomarkers as a minimally invasive and additional tool for monitoring the activity of IBD.

The preventive effects of native probiotic and postbiotic on inflammation and oxidative stress in DSS-induced colitis with normal diet: Which of these agents may offer greater advantages?

Background

Maintaining a well-rounded and healthy diet is essential to promote the well-being and optimal performance of the body, especially for those suffering from Inflammatory Bowel Disease (IBD). The objective of this study is to examine whether probiotics and postbiotics can modulate oxidative stress and inflammation, and to evaluate the properties of these compounds.

Methods

A total of eighty eight strains of Lactobacillus and Bifidobacterium were assessed for their antioxidant activities. C57BL/6 mice were allocated into four groups: normal diet (ND) + PBS, ND + DSS, ND + DSS + 10⁹ cfu/ml of probiotics, and ND + DSS + 10⁹ cfu/ml of postbiotics. Biochemical antioxidant assays, along with colitis indices, were evaluated. The ELISA assay was conducted to measure oxidant/antioxidant properties and cytokines. Additionally, the genes enrolled in NF-kB and Nrf2 signaling pathways was analyzed.

Results

In comparison to the groups exposed to DSS alone, mice that received our native agents in addition to DSS demonstrated an improvement in the negative effects induced by DSS on DAI and pathological scores, as well as on colon length and body weight. The levels of cytokines and antioxidant markers have also been normalized following the administration of our native agents, along with molecular markers. It should also be noted that our native postbiotic was able to develop more pronounced and significant anti-inflammatory and antioxidant effects in comparison to the probiotic strains.

Conclusion

In this study, our native postbiotic has demonstrated a more pronounced ability to exhibit antioxidant and anti-inflammatory effects. This finding is particularly important for individuals with impaired immune function, for whom the use of live bacteria could be risky. Therefore, the utilization of agents like probiotics and postbiotics, which come with minimal side effects in compared to chemical drugs, could be essential in managing symptoms in IBD patients.

Nanotechnology for Targeted Inflammatory Bowel Disease Therapy: Challenges and Opportunities

Inflammatory bowel disease (IBD) is a complex and recurring inflammatory disorder that affects the gastrointestinal tract and is influenced by genetic predisposition, immune dysregulation, the gut microbiota, and environmental factors. Advanced therapies, such as biologics and small molecules, target diverse immune pathways to manage IBD. Nanoparticle (NP)-based drugs have emerged as effective tools, offering controlled drug release and targeted delivery. This review highlights NP modifications for anti-inflammatory purposes, utilizing changes such as those in size, charge, redox reactions, and ligand-receptor interactions in drug delivery systems. By using pathological and microenvironmental cues to guide NP design, precise targeting can be achieved. In IBD, a crucial aspect of NP intervention is targeting specific types of cells, such as immune and epithelial cells, to address compromised intestinal barrier function and reduce overactive immune responses. This review also addresses current challenges and future prospects, with the goal of advancing the development of NP-mediated strategies for IBD treatment.

Oral Health and "Modern" Digestive Diseases: Pathophysiologic and Etiologic Factors

In the contemporary era of medicine, exploring the complexity of the human body and its intricate interactions has become a central concern for health researchers. The main purpose of this article is to summarize the current understanding of relevant pathophysiological factors such as chronic inflammation, dysbiosis (microbial imbalance), and metabolic disorders, as well as etiological factors including dietary habits, lifestyle choices, obesity, metabolic syndrome, and genetic predispositions, as well as to emphasize potential avenues for upcoming studies and their medical significance. Additionally, this article aims to assess the potential impact of integrated treatment approaches on patient outcomes, emphasizing the need for interdisciplinary collaboration between gastroenterologists, dentists, and other healthcare professionals to develop comprehensive care plans that address both oral and digestive health issues simultaneously. Among the branches with a significant impact on general well-being are oral cavity health and digestive diseases, which have been the subject of intensive research in recent decades. In this context, analysis of the current state of knowledge on oral cavity disorders in relation to "modern" digestive diseases such as non-alcoholic fatty liver disease (NAFLD), small intestinal bacterial overgrowth (SIBO), inflammatory bowel disease (IBD), and irritable bowel syndrome (IBS) becomes essential for a deeper understanding of the interconnections between oral and digestive health. The temporal overlap or succession, whether preceding or following, of oral manifestations and digestive disorders should be taken seriously by both gastroenterologists and dentists to facilitate early diagnosis and explain to patients the correlation between these two body systems. In summary, this article underscores the importance of understanding the intricate relationship between oral and digestive health, advocating for interdisciplinary approaches to improve patient outcomes and guide future research.

Enhanced Risk of Gastroesophageal Reflux Disease and Esophageal Complications in the Ulcerative Colitis Population

Background: Although heartburn and reflux are frequently reported in ulcerative colitis [UC], the correlation between UC and gastroesophageal reflux disease [GERD], and its complications, esophageal stricture and Barrett's esophagus [BE], is not well understood. This study aims to examine the prevalence and associated risk of GERD and its complications within the UC population. Methods: We analyzed the National Inpatient Sample (NIS) dataset, consisting of 7,159,694 patients, comparing GERD patients with and without UC to those without GERD. We assessed the degree of colonic involvement in UC and the occurrence of esophageal complications. Bivariate analyses were conducted using the chi-squared test or Fisher exact test (two-tailed). Results: A higher prevalence of GERD (23.0% vs. 16.5%) and GERD phenotypes, such as non-erosive reflux disease (NERD) (22.3% vs. 16%) and erosive esophagitis (EE) (1.2% vs. 0.6%), was found in UC patients (p < 0.01), including pancolitis, proctitis, proctosigmoiditis, left-sided colitis, and indetermined UC (with undefined colonic involvement). UC patients were more likely to develop GERD (1.421), NERD (1.407), and EE (1.681) (p < 0.01). A higher prevalence of esophageal stricture (16.9 vs. 11.4 per 10,000 patients) and BE without dysplasia (94.5 vs. 39.3 per 10,000 patients) was found in UC (p < 0.05). The odds of developing BE without dysplasia were higher (1.892) in patients with UC (p < 0.01), including ulcerative pancolitis, proctitis, and indeterminate UC (OR of 1.657, 3.328, and 1.996, respectively) (p < 0.05). Conclusions: Our study demonstrates an increased risk of developing GERD and its complications in UC. This highlights the importance of vigilant monitoring and early intervention to minimize associated GERD-related risks in patients with UC.

Stable Nitroxide as Diagnostic Tools for Monitoring of Oxidative Stress and Hypoalbuminemia in the Context of COVID-19

Oxidative stress is a major source of ROS-mediated damage to macromolecules, tissues, and the whole body. It is an important marker in the severe picture of pathological conditions. The discovery of free radicals in biological systems gives a "start" to studying various pathological processes related to the development and progression of many diseases. From this moment on, the enrichment of knowledge about the participation of free radicals and free-radical processes in the pathogenesis of cardiovascular, neurodegenerative, and endocrine diseases, inflammatory conditions, and infections, including COVID-19, is increasing exponentially. Excessive inflammatory responses and abnormal reactive oxygen species (ROS) levels may disrupt mitochondrial dynamics, increasing the risk of cell damage. In addition, low serum albumin levels and changes in the normal physiological balance between reduced and oxidized albumin can be a serious prerequisite for impaired antioxidant capacity of the body, worsening the condition in patients. This review presents the interrelationship between oxidative stress, inflammation, and low albumin levels, which are hallmarks of COVID-19.

Neohesperidin Dihydrochalcone Ameliorates Experimental Colitis via Anti-Inflammatory, Antioxidative, and Antiapoptosis Effects

Neohesperidin dihydrochalcone (NHDC) is a citrus-originated, seminatural sweetener. There is no investigation concerning the effect of NHDC on ulcerative colitis. The purpose of this study was to determine the therapeutic and protective effects of NHDC in Wistar Albino rats. NHDC was given for 7 days after or before colitis induction. The results showed that NHDC significantly reduced the interleukin-6 (IL-6), interleukin-10 (IL-10), transforming growth factor-β1 (TGF-β1), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) levels. Catalase levels did not show a significant difference between the groups. NHDC provided a remarkable decrease in the expression levels of cyclooxygenase-2 (COX-2), myeloperoxidase (MPO), malondialdehyde (MDA), 8-hydroxy-2'-deoxyguanosine (8-OHdG), and nuclear factor kappa B (NF-κB). Total antioxidant status (TAS) levels were significantly elevated in NHDC treatment groups, while total oxidant status (TOS) and oxidative stress index (OSI) levels were significantly decreased. NHDC provided remarkable improvement in histological symptoms such as epithelial erosion, edema, mucosal necrosis, inflammatory cell infiltration, and hemorrhage. Also, caspase-3 expression levels were statistically decreased in NHDC treatment groups. The results indicated that NHDC might be a protection or alternative treatment for ulcerative colitis.

The emerging role of oxidative stress in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic immune-mediated condition that affects the digestive system and includes Crohn's disease (CD) and ulcerative colitis (UC). Although the exact etiology of IBD remains uncertain, dysfunctional immunoregulation of the gut is believed to be the main culprit. Amongst the immunoregulatory factors, reactive oxygen species (ROS) and reactive nitrogen species (RNS), components of the oxidative stress event, are produced at abnormally high levels in IBD. Their destructive effects may contribute to the disease's initiation and propagation, as they damage the gut lining and activate inflammatory signaling pathways, further exacerbating the inflammation. Oxidative stress markers, such as malondialdehyde (MDA), 8-hydroxy-2'-deoxyguanosine (8-OHdG), and serum-free thiols (R-SH), can be measured in the blood and stool of patients with IBD. These markers are elevated in patients with IBD, and their levels correlate with the severity of the disease. Thus, oxidative stress markers can be used not only in IBD diagnosis but also in monitoring the response to treatment. It can also be targeted in IBD treatment through the use of antioxidants, including vitamin C, vitamin E, glutathione, and N-acetylcysteine. In this review, we summarize the role of oxidative stress in the pathophysiology of IBD, its diagnostic targets, and the potential application of antioxidant therapies to manage and treat IBD.

Exploring Therapeutic Potential of Catalase: Strategies in Disease Prevention and Management

The antioxidant defense mechanisms play a critical role in mitigating the deleterious effects of reactive oxygen species (ROS). Catalase stands out as a paramount enzymatic antioxidant. It efficiently catalyzes the decomposition of hydrogen peroxide (H2O2) into water and oxygen, a potentially harmful byproduct of cellular metabolism. This reaction detoxifies H2O2 and prevents oxidative damage. Catalase has been extensively studied as a therapeutic antioxidant. Its applications range from direct supplementation in conditions characterized by oxidative stress to gene therapy approaches to enhance endogenous catalase activity. The enzyme's stability, bioavailability, and the specificity of its delivery to target tissues are significant hurdles. Furthermore, studies employing conventional catalase formulations often face issues related to enzyme purity, activity, and longevity in the biological milieu. Addressing these challenges necessitates rigorous scientific inquiry and well-designed clinical trials. Such trials must be underpinned by sound experimental designs, incorporating advanced catalase formulations or novel delivery systems that can overcome existing limitations. Enhancing catalase's stability, specificity, and longevity in vivo could unlock its full therapeutic potential. It is necessary to understand the role of catalase in disease-specific contexts, paving the way for precision antioxidant therapy that could significantly impact the treatment of diseases associated with oxidative stress.

Colonic Dysregulation of Major Metabolic Pathways in Experimental Ulcerative Colitis

Inflammatory bowel disease (IBD) is multifactorial chronic inflammatory disease in the gastrointestinal tract, affecting patients' quality of life profoundly. The incidence of IBD has been on the rise globally for the last two decades. Because the molecular mechanisms underlying the disease remain not well understood, therapeutic development is significantly impeded. Metabolism is a crucial cellular process to generate the energy needed for an inflammatory response and tissue repair. Comprehensive understanding of the metabolic pathways in IBD would help to unravel the disease pathogenesis/progression and facilitate therapeutic discoveries. Here, we investigated four metabolic pathways altered in experimental colitis. C57BL/6J mice were treated with dextran sulfate sodium (DSS) in drinking water for 7 days to induce experimental ulcerative colitis (UC). We conducted proteomics analysis for the colon samples using LC/MS, to profile key metabolic intermediates. Our findings revealed significant alterations in four major metabolic pathways: antioxidative defense, β-oxidation, glycolysis, and TCA cycle pathways. The energy metabolism by β-oxidation, glycolysis, and TCA cycle pathways were downregulated under UC, together with reduced antioxidative defense pathways. These results reveal metabolic re-programming in intestinal cells under UC, showing dysregulation in all four major metabolic pathways. Our study underscores the importance of metabolic drivers in the pathogenesis of IBD and suggests that the modification of metabolism may serve as a novel diagnostic/therapeutic approach for IBD.

Prospective Evaluation of Serum Free Thiols in Inflammatory Bowel Disease: A Candidate to Replace C-Reactive Protein for Disease Activity Assessment?

BACKGROUND

Serum free thiols (SFTs) reflecting oxidative stress appear to correlate with inflammatory bowel disease (IBD) activity. We aimed to evaluate the performance of SFTs concentrations vs endoscopic and histological activity, compare SFTs with established biomarkers, and identify clinical and laboratory parameters independently associated with SFT levels in IBD patients.

METHODS

Patients with confirmed IBD undergoing routine ileocolonoscopy for activity assessment were prospectively recruited, with serum samples obtained concurrently for SFTs and routine bloods, plus fecal calprotectin and immunochemical tests were collected ±30 days from ileocolonoscopy. Endoscopic activity was assessed via established indices and histological activity graded as inactive/mild/moderate. Receiver-operating characteristic curve analyses were utilized to assess performance of SFTs vs endoscopic activity, and multiple regression analysis was used to identify factors associated with SFT levels.

RESULTS

A total of 141 (80 Crohn's disease, 61 ulcerative colitis) patients were recruited. Median SFTs were significantly lower in moderate vs inactive/mild endoscopic activity (309 µM vs 433/471 µM, respectively; P < .01). There was no significant difference in median SFTs across inactive/mild/moderate histological activity. SFTs achieved higher sensitivity than C-reactive protein in predicting moderate, endoscopically active disease (89% vs 78%; area under the curve, 0.80 each) yet was outperformed by fecal calprotectin (100%; area under the curve, 0.93). Advancing age and increasing albumin levels were independently associated with SFT levels, and thus are possible confounders.

CONCLUSIONS

This prospective study has demonstrated the potential of SFTs as a serum biomarker in IBD. It was more sensitive than C-reactive protein, yet less sensitive than fecal biomarkers for prediction of endoscopically active IBD.

Differential Gene Expression Profiles in Inflammatory Bowel Disease Patients from Kurdistan, Iraq

Objectives

Inflammatory bowel disease (IBD), generally comprising Crohn's disease (CD) and ulcerative colitis (UC), has become a significant global public health concern in the last decade. This study aimed to determine the alternations in the whole genomic expression profile of patients with IBD in this geographic location for the first time, as there are very few articles in the literature addressing this specific aspect of the field.

Methods

The study was conducted in Erbil Governorate in the Kurdistan region of Iraq from July 2021 to July 2022. The genome expression profiles of 10 patients with IBD were compared to their matched controls. The sequences used in the design of the array were selected from GenBank®, dbEST and RefSeq. Whole blood RNA was extracted and hybridisation was conducted on the GeneChip® human genome U133A 2.0 array. The Scanner 3000 was used to scan high-resolution images and the General Comprehensive Operating System was used to read the results.

Results

The upregulated genes shared between patients with UC and CD were RIT2, BCL2L1, MDM2 and FKBP8, while the downregulated genes they shared were the NFKBIB, DDX24 and RASA3 genes.

Conclusions

Upregulated and downregulated gene expression patterns were detected in individuals with IBD, offering diagnostic potential and opportunities for treatment by targeting the associated pathways.

Transient gestational hypothyroxinemia accelerates and enhances ulcerative colitis-like disorder in the male offspring

Introduction

Gestational hypothyroxinemia (HTX) is a condition that occurs frequently at the beginning of pregnancy, and it correlates with cognitive impairment, autism, and attentional deficit in the offspring. Evidence in animal models suggests that gestational HTX can increase the susceptibility of the offspring to develop strong inflammation in immune-mediated inflammatory diseases. Ulcerative colitis (UC) is a frequent inflammatory bowel disease with unknown causes. Therefore, the intensity of ulcerative colitis-like disorder (UCLD) and the cellular and molecular factors involved in proinflammatory or anti-inflammatory responses were analyzed in the offspring gestated in HTX (HTX-offspring) and compared with the offspring gestated in euthyroidism (Control-offspring).

Methods

Gestational HTX was induced by the administration of 2-mercapto-1-methylimidazole in drinking water to pregnant mice during E10-E14. The HTX-offspring were induced with UCLD by the acute administration of dextran sodium sulfate (DSS). The score of UCLD symptomatology was registered every day, and colon histopathology, immune cells, and molecular factors involved in the inflammatory or anti-inflammatory response were analyzed on day 6 of DSS treatment.

Results

The HTX-offspring displayed earlier UCLD pathological symptoms compared with the Control-offspring. After 6 days of DSS treatment, the HTX-offspring almost doubled the score of the Control-offspring. The histopathological analyses of the colon samples showed signs of inflammation at the distal and medial colon for both the HTX-offspring and Control-offspring. However, significantly more inflammatory features were detected in the proximal colon of the HTX-offspring induced with UCLD compared with the Control-offspring induced with UCLD. Significantly reduced mRNA contents encoding for protective molecules like glutamate-cysteine ligase catalytic subunit (GCLC) and mucin-2 (MUC-2) were found in the colon of the HTX-offspring as compared with the Control-offspring. Higher percentages of Th17 lymphocytes were detected in the colon tissues of the HTX-offspring induced or not with UCLD as compared with the Control-offspring.

Discussion

Gestational HTX accelerates the onset and increases the intensity of UCLD in the offspring. The low expression of MUC-2 and GCLC together with high levels of Th17 Lymphocytes in the colon tissue suggests that the HTX-offspring has molecular and cellular features that favor inflammation and tissue damage. These results are important evidence to be aware of the impact of gestational HTX as a risk factor for UCLD development in offspring.

Anti-oxidant and anti-inflammatory potential of different polymer-based mesalamine delayed-release granules in TNBS-induced ulcerative colitis in wistar rats

Ulcerative colitis (UC) is an inflammatory condition of colon characterized by severe damage to the innermost colon tissues. A number of studies described the use of medication delivery systems based on natural polymers like polysaccharides for the purpose of reaching the colon. In this research, polymer-based mesalamine delayed-release granules (DRGs) were tested for their antioxidant and anti-inflammatory efficacy against UC. Chitosan (C), pectin (P), and pectin-chitosan (PC) mesalamine (M) DRGs were prepared and characterized. Data revealed satisfactory compatibility, flow, packing properties, drug release pattern, and delayed drug release by DRGs. Wistar rats were treated with 2,4,6-trinitrobenzenesulfonic acid (TNBS) (100 mg/kg) via rectal administration. Mesalamine and mesalamine DRGs (50 mg/kg) were administered orally separately for 14 days. Biomarkers of oxidative stress, inflammation, hematological tests, colon profile, and histopathology were performed. The findings demonstrated the good efficacy of the polysaccharides in delivering mesalamine to colon. Mesalamine and mesalamine DRGs based on various polymers showed significant antioxidant and anti-inflammatory effects in rats with UC. Mesalamine granules significantly attenuated colon lipid peroxidation, nitrites, myeloperoxidase activity, and interleukin-1β levels, and improved anti-oxidants (GSH, SOD). Data showed upregulation of Nrf2 activity by mesalamine granules with CM-DRGs showing maximum effect. Mesalamine and different polymer-based mesalamine DRGs significantly attenuated TNBS-induced decline in body weight, ulcer severity, and colon damage. CM-DRGs showed the most pronounced ameliorative effect on colon and hematology parameters via anti-oxidant and anti-inflammatory activities. Chitosan can be used as a carrier for oral colon delivery of mesalamine in DRG formulation for enhanced therapeutic efficacy in UC.

Relationship between bilirubin and systemic lupus erythematosus: A systematic review and meta-analysis

AIMS

Systemic lupus erythematosus (SLE) is an autoimmune disease with a high prevalence worldwide. This study aimed to examine the correlation between serum bilirubin levels and SLE.

METHODS

The Cochrane library, Embase, PubMed, and China National Knowledge Infrastructure (CNKI) databases were examined and assessed until March 2023. RevMan 5.3 software was utilized for the analysis of clinical trails.

RESULTS

Five case-control studies were chosen and incorporated, examining the levels of serum bilirubin in patients with SLE compared to healthy individuals, as well as in active SLE patients versus inactive ones, in different sexes and in SLE patients with or without lupus nephritis (LN). The results of this meta-analysis demonstrated that serum bilirubin in healthy individuals were obviously increased compared to SLE patients (MD = 4.76; 95% CI, 3.15-6.38, p < .00001). Additionally, inactive SLE patients had higher levels of bilirubin than active SLE patients (MD = 3.15; 95% CI, 0.46-5.84, p = .02), and SLE patients without lupus nephritis had higher levels of serum bilirubin than those with lupus nephritis (MD = 4.91;95% CI, 2.87-6.95, p < .00001). Nevertheless, there were no disparities observed among SLE patients of varying sexes (MD = 0.34; 95% CI, -0.01 to 0.69, p = .06).

CONCLUSION

The concentration of serum bilirubin may potentially be used as an indicator for estimating the advancement of SLE and reflecting the presence of kidney complications in individuals with SLE. Furthermore, more high quality studies were needed to identify these findings.

Arabinogalactan Alleviates Lipopolysaccharide-Induced Intestinal Epithelial Barrier Damage through Adenosine Monophosphate-Activated Protein Kinase/Silent Information Regulator 1/Nuclear Factor Kappa-B Signaling Pathways in Caco-2 Cells

Intestinal epithelial barrier (IEB) damage is an important aspect in inflammatory bowel disease (IBD). The objective of this study was to explore the protective effects and mechanisms of arabinogalactan (AG) on lipopolysaccharide (LPS)-stimulated IEB dysfunction. The results show that AG (1, 2, and 5 mg/mL) mitigated 100 μg/mL LPS-stimulated IEB dysfunction through increasing transepithelial electrical resistance (TEER), reducing fluorescein isothiocyanate (FITC)-dextran (4 kDa) flux, and up-regulating the protein and mRNA expression of tight junction (TJ) proteins (Claudin-1, Zonula occludens-1 (ZO-1) and Occludin). In addition, AG ameliorated LPS-stimulated IEB dysfunction by reducing interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and IL-1β levels, decreasing the reactive oxygen species (ROS) level, increasing superoxide dismutase (SOD) activity, increasing the glutathione (GSH) level, and decreasing the levels of malondialdehyde (MDA) and intracellular calcium ([Ca2+]i). Furthermore, 2 mg/mL AG up-regulated the expression of silent information regulator 1 (SIRT1), the phosphorylated adenosine monophosphate-activated protein kinase (AMPK), and peroxisome proliferator-activated receptor gamma coactivator (PGC)-1α and inhibited the phosphorylation of nuclear factor kappa-B (NF-κB) and the inhibitor of NF-κBα (IκBα). Therefore, AG could maintain IEB integrity by activating AMPK/SIRT1 and inhibiting the NF-κB signaling pathway. In conclusion, AG can regulate the AMPK/SIRT1/NF-κB signaling pathway to reduce inflammation and oxidative stress, thus alleviating LPS-stimulated IEB damage.

The Importance of Antioxidant Activity for the Health-Promoting Effect of Lycopene

Lycopene is a compound of colored origin that shows strong antioxidant activity. The positive effect of lycopene is the result of its pleiotropic effect. The ability to neutralize free radicals via lycopene is one of the foundations of its pro-health effect, including the ability to inhibit the development of many civilization diseases. Therefore, this study focuses on the importance of the antioxidant effect of lycopene in inhibiting the development of diseases such as cardiovascular diseases, diseases within the nervous system, diabetes, liver diseases, and ulcerative colitis. According to the research mentioned, lycopene supplementation has significant promise for the treatment of illnesses marked by chronic inflammation and oxidative stress. However, the majority of the supporting data for lycopene's health benefits comes from experimental research, whereas the evidence from clinical studies is both scarcer and less certain of any health benefits. Research on humans is still required to establish its effectiveness.

Voluntary Exercise-Mediated Protection in TNBS-Induced Rat Colitis: The Involvement of NETosis and Prdx Antioxidants

Inflammatory bowel diseases (IBDs) are autoimmune disorders of the gut. It is increasingly clear that voluntary exercise (VE) may exert protection against IBDs, but the exact background mechanism needs to be elucidated. In the present study, we aimed to investigate the possible role of NETosis and the antioxidant peroxiredoxin (Prdx) enzyme family in VE-induced protection. Wistar Han rats were randomly divided into two groups: sedentary (SED) and VE. After the 6-week voluntary wheel running, animals were treated with 2,4,6-trinitrobenzene sulphonic acid (TNBS) as a model of colitis. Here, we found that VE significantly decreased inflammation and ulceration of the colon in the VE TNBS group compared with SED TNBS. We also found that VE significantly decreased the expression of protein arginine deiminase 4 (PAD4) and myeloperoxidase (MPO), and markedly reduced citrullinated histone H3 (citH3) compared with SED TNBS. Furthermore, VE caused a significant increase in the levels of Prdx6 in the control and TNBS groups. Taken together, we found that a prior 6-week VE effectively reduces inflammation in TNBS-induced colitis, and we suggest that the protective effect of VE may be mediated via the inhibition of NETosis and upregulation of Prdx6 antioxidant.

Oxidative stress gene expression, DNA methylation, and gut microbiota interaction trigger Crohn's disease: a multi-omics Mendelian randomization study

BACKGROUND

Oxidative stress (OS) is a key pathophysiological mechanism in Crohn's disease (CD). OS-related genes can be affected by environmental factors, intestinal inflammation, gut microbiota, and epigenetic changes. However, the role of OS as a potential CD etiological factor or triggering factor is unknown, as differentially expressed OS genes in CD can be either a cause or a subsequent change of intestinal inflammation. Herein, we used a multi-omics summary data-based Mendelian randomization (SMR) approach to identify putative causal effects and underlying mechanisms of OS genes in CD.

METHODS

OS-related genes were extracted from the GeneCards database. Intestinal transcriptome datasets were collected from the Gene Expression Omnibus (GEO) database and meta-analyzed to identify differentially expressed genes (DEGs) related to OS in CD. Integration analyses of the largest CD genome-wide association study (GWAS) summaries with expression quantitative trait loci (eQTLs) and DNA methylation QTLs (mQTLs) from the blood were performed using SMR methods to prioritize putative blood OS genes and their regulatory elements associated with CD risk. Up-to-date intestinal eQTLs and fecal microbial QTLs (mbQTLs) were integrated to uncover potential interactions between host OS gene expression and gut microbiota through SMR and colocalization analysis. Two additional Mendelian randomization (MR) methods were used as sensitivity analyses. Putative results were validated in an independent multi-omics cohort from the First Affiliated Hospital of Sun Yat-sen University (FAH-SYS).

RESULTS

A meta-analysis from six datasets identified 438 OS-related DEGs enriched in intestinal enterocytes in CD from 817 OS-related genes. Five genes from blood tissue were prioritized as candidate CD-causal genes using three-step SMR methods: BAD, SHC1, STAT3, MUC1, and GPX3. Furthermore, SMR analysis also identified five putative intestinal genes, three of which were involved in gene-microbiota interactions through colocalization analysis: MUC1, CD40, and PRKAB1. Validation results showed that 88.79% of DEGs were replicated in the FAH-SYS cohort. Associations between pairs of MUC1-Bacillus aciditolerans and PRKAB1-Escherichia coli in the FAH-SYS cohort were consistent with eQTL-mbQTL colocalization.

CONCLUSIONS

This multi-omics integration study highlighted that OS genes causal to CD are regulated by DNA methylation and host-microbiota interactions. This provides evidence for future targeted functional research aimed at developing suitable therapeutic interventions and disease prevention.

Antioxidants as Protection against Reactive Oxidative Stress in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) belongs to a group of chronic diseases characterised by periods of exacerbation and remission. Despite many studies and observations, its aetiopathogenesis is still not fully understood. The interactions of genetic, immunological, microbiological, and environmental factors can induce disease development and progression, but there is still a lack of information on these mechanisms. One of the components that can increase the risk of occurrence of IBD, as well as disease progression, is oxidative stress. Oxidative stress occurs when there is an imbalance between reactive oxygen species (ROS) and antioxidants. The endogenous and exogenous components that make up the body's antioxidant defence can significantly affect IBD prophylaxis and reduce the risk of exacerbation by neutralising and removing ROS, as well as influencing the inflammatory state.

Oxidative Stress, Inflammation and Colorectal Cancer: An Overview

Colorectal cancer (CRC) represents the second leading cause of cancer-related deaths worldwide. The pathogenesis of CRC is a complex multistep process. Among other factors, inflammation and oxidative stress (OS) have been reported to be involved in the initiation and development of CRC. Although OS plays a vital part in the life of all organisms, its long-term effects on the human body may be involved in the development of different chronic diseases, including cancer diseases. Chronic OS can lead to the oxidation of biomolecules (nucleic acids, lipids and proteins) or the activation of inflammatory signaling pathways, resulting in the activation of several transcription factors or the dysregulation of gene and protein expression followed by tumor initiation or cancer cell survival. In addition, it is well known that chronic intestinal diseases such as inflammatory bowel disease (IBD) are associated with an increased risk of cancer, and a link between OS and IBD initiation and progression has been reported. This review focuses on the role of oxidative stress as a causative agent of inflammation in colorectal cancer.

Platycodon grandiflorus polysaccharide regulates colonic immunity through mesenteric lymphatic circulation to attenuate ulcerative colitis

Platycodon grandiflorus polysaccharide (PGP) is one of the main components of P. grandiflorus, but the mechanism of its anti-inflammatory effect has not been fully elucidated. The aim of this study was to evaluate the therapeutic effect of PGP on mice with dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) and explore the underlying mechanisms. The results showed that PGP treatment inhibited the weight loss of DSS-induced UC mice, increased colon length, and reduced DAI, spleen index, and pathological damage within the colon. PGP also reduced the levels of pro-inflammatory cytokines and inhibited the enhancement of oxidative stress and MPO activity. Meanwhile, PGP restored the levels of Th1, Th2, Th17, and Treg cell-related cytokines and transcription factors in the colon to regulate colonic immunity. Further studies revealed that PGP regulated the balance of colonic immune cells through mesenteric lymphatic circulation. Taken together, PGP exerts anti-inflammatory and anti-oxidant effect and regulates colonic immunity to attenuate DSS-induced UC through mesenteric lymphatic circulation.

Natural Coumarin Derivatives Activating Nrf2 Signaling Pathway as Lead Compounds for the Design and Synthesis of Intestinal Anti-Inflammatory Drugs

Nrf2 (nuclear factor erythroid 2-related factor 2) is a transcription factor related to stress response and cellular homeostasis that plays a key role in maintaining the redox system. The imbalance of the redox system is a triggering factor for the initiation and progression of non-communicable diseases (NCDs), including Inflammatory Bowel Disease (IBD). Nrf2 and its inhibitor Kelch-like ECH-associated protein 1 (Keap1) are the main regulators of oxidative stress and their activation has been recognized as a promising strategy for the treatment or prevention of several acute and chronic diseases. Moreover, activation of Nrf2/keap signaling pathway promotes inhibition of NF-κB, a transcriptional factor related to pro-inflammatory cytokines expression, synchronically promoting an anti-inflammatory response. Several natural coumarins have been reported as potent antioxidant and intestinal anti-inflammatory compounds, acting by different mechanisms, mainly as a modulator of Nrf2/keap signaling pathway. Based on in vivo and in vitro studies, this review focuses on the natural coumarins obtained from both plant products and fermentative processes of food plants by gut microbiota, which activate Nrf2/keap signaling pathway and produce intestinal anti-inflammatory activity. Although gut metabolites urolithin A and urolithin B as well as other plant-derived coumarins display intestinal anti-inflammatory activity modulating Nrf2 signaling pathway, in vitro and in vivo studies are necessary for better pharmacological characterization and evaluation of their potential as lead compounds. Esculetin, 4-methylesculetin, daphnetin, osthole, and imperatorin are the most promising coumarin derivatives as lead compounds for the design and synthesis of Nrf2 activators with intestinal anti-inflammatory activity. However, further structure-activity relationships studies with coumarin derivatives in experimental models of intestinal inflammation and subsequent clinical trials in health and disease volunteers are essential to determine the efficacy and safety in IBD patients.

Oligosaccharides of Polygonatum Cyrtonema Hua ameliorates dextran sulfate sodium-induced colitis and regulates the gut microbiota

Ulcerative colitis (UC) is one common chronic inflammatory bowel disease that causes severe side effects, and expensive treatment limits effective and sustained treatment of UC. Fructooligosaccharide was isolated from Polygonatum Cyrtonema Hua (PFOS) and exhibits anti-inflammatory effects. Therefore, we are curious whether PFOS could be used for the treatment of UC. PFOS was introduced via intragastric gavage to C57BL/6 J mice exposed to acute colitis induced by DSS. The results showed that doses of PFOS at 2 and 5 mg/kg/day alleviated the DSS-induced histopathological damage and improved intestinal barrier function. qPCR analysis revealed that PFOS exerted a significant downregulation of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) and upregulation of antioxidant genes, including superoxide dismutase1 (SOD1), glutathion peroxidase2 (GPX2), and nuclear factor erythroid 2 related factor2 (Nrf2). Furthermore, PFOS suppressed the DSS-induced disruption of the mucosal barrier by downregulating MMP13. Moreover, using 16 S rRNA gene-based microbiota analysis, PFOS could selectively enhance the growth of probiotics, including Bifidobacterium, Alloprevofella, and Alistipes. Our findings indicated that PFOS attenuated DSS-induced colitis in mice, suggesting that PFOS might be used as an efficacious supplement for reducing inflammatory bowel disease.

Efficacy of TurmiZn, a Metallic Complex of Curcuminoids-Tetrahydrocurcumin and Zinc on Bioavailability, Antioxidant, and Cytokine Modulation Capability

Complexes of curcumin with metals have shown much-improved stability, solubility, antioxidant capability, and efficacy when compared to curcumin. The present research investigates the relative bioavailability, antioxidant, and ability to inhibit inflammatory cytokine production of a curcuminoid metal chelation complex of tetrahydrocurcumin-zinc-curcuminoid termed TurmiZn. In vitro uptake assay using pig intestinal epithelial cells showed that TurmiZn has an ~3-fold increase (p ≤ 0.01) in uptake compared to curcumin and a ~2-fold increase (p ≤ 0.01) over tetrahydrocurcumin (THC). In a chicken model, an oral 1-g dose of TurmiZn showed a ~2.5-fold increase of a specific metabolite peak compared to curcumin (p = 0.004) and a ~3-fold increase compared to THC (p = 0.001). Oral doses (5 g/Kg) of TurmiZn in rats also showed the presence of curcumin and THC metabolites in plasma, indicating bioavailability across cell membranes in animals. Determination of the antioxidant activity by a 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical scavenging assay indicated that TurmiZn was about 13x better (p ≤ 0.0001) than curcumin and about 4X better (p ≤ 0.0001) than THC, in reducing free radicals. In vitro experiments further showed significant (p ≤ 0.01) reductions of lipopolysaccharide (LPS)-induced proinflammatory cytokines such as interleukin (IL) IL-6, IL-8, IL-15, IL-18, and tumor necrosis factor (TNF)-alpha, while showing a significant (p ≤ 0.01) increase of granulocyte-macrophage colony-stimulating factor (GM-CSF) in dog kidney cells. In vivo cytokine modulations were also observed when TurmiZn was fed for 6 weeks to newborn chickens. TurmiZn reduced IL-1 and IL-6, but significantly reduced (p ≤ 0.01) IL-10 levels while there was a concurrent significant (p = 0.02) increase in interferon gamma compared to controls. Overall, these results indicate that TurmiZn has better bioavailability and antioxidant capability than curcumin or THC and has the ability to significantly modulate cytokine levels. Thus, TurmiZn could be an excellent candidate for a novel ingredient that can be incorporated into food and supplements to help overall health during the aging process.

Mitochondrial Control in Inflammatory Gastrointestinal Diseases

Mitochondria play a central role in the pathophysiology of inflammatory bowel disease (IBD) and colorectal cancer (CRC). The maintenance of mitochondrial function is necessary for a stable immune system. Mitochondrial dysfunction in the gastrointestinal system leads to the excessive activation of multiple inflammatory signaling pathways, leading to IBD and increased severity of CRC. In this review, we focus on the mitochondria and inflammatory signaling pathways and its related gastrointestinal diseases.

Pharmacological inhibition of toll-like receptor 4 with TLR4-IN-C34 modulates the intestinal flora homeostasis and the MyD88/NF-κB axis in ulcerative colitis

Toll-like receptor 4, a highly conserved protein of innate immunity, is responsible for the regulation and maintenance of homeostasis. It has been implicated in the progression of ulcerative colitis (UC) by interacting with its downstream pathway myeloid differentiation factor 88 (MyD88) and nuclear factor kappa B (NF-κB). This study aimed to evaluate the effect of a specific inhibitor of toll-like receptor 4, TLR4-IN-C34 on gut microbiota to elucidate its mechanism in UC mice. Dextran sulfate sodium significantly induced weight loss, diarrhea and rectal bleeding, and colonic damage in mice, which occurred concomitant with dysbiosis of intestinal flora. Intestinal dysbiosis were partially ameliorated by TLR4-IN-C34. Meanwhile, a reduction in inflammatory cell infiltration, enhanced antioxidant activity in colon tissues, and reconstruction of intestinal barrier were observed in mice administrated with TLR4-IN-C34. MyD88 and NF-κB were significantly reduced after TLR4-IN-C34 treatment. MyD88^-/- mice were found with improved dysbiosis of intestinal flora, which was mitigated by overexpression of NF-κB. Collectively, our results suggest that TLR4-IN-C34 alleviates UC in mice by blocking the MyD88/NF-κB pathway to improve intestinal flora dysbiosis, inflammatory infiltration, oxidative stress and intestinal barrier function.

Probiotic treatment of inflammatory bowel disease: Its extent and intensity

Free radicals (reactive oxygen species, superoxides and hydroxyl radicals) lead to the development of oxidative stress because of imbalance in the amount of antioxidants. Continued development of oxidative stress leads to chronic diseases in humans. The instability in the antioxidant activities and accumulation of oxidative stress due to free radicals may occur in diseases like inflammatory bowel disease (IBD). Antioxidants are substances that inhibit or delay the mechanism of oxidation of molecules mediated by free radicals and also transform into lesser-active derivatives. Probiotics are defined as live microorganisms that show beneficial effects on inflamed intestine and balance the inflammatory immune responses in the gut. Probiotic strains have been reported to scavenge hydroxyl radicals and superoxide anions that are abundantly produced during oxidative stress. The most widely studied probiotic strains are Streptococcus, Bifidobacterium and Lactobacillus. Probiotics cultured in broth have shown some amount of antioxidant activities. Fermented milk and soy milk, which possess starter microorganisms (probiotics), tends to increase the antioxidant activities many-fold. This review aims to discuss the in vivo and in vitro antioxidant activities of specific probiotics with various assays with respect to IBD.

Artificial Intelligence Analysis of Celiac Disease Using an Autoimmune Discovery Transcriptomic Panel Highlighted Pathogenic Genes including BTLA

Celiac disease is a common immune-related inflammatory disease of the small intestine caused by gluten in genetically predisposed individuals. This research is a proof-of-concept exercise focused on using Artificial Intelligence (AI) and an autoimmune discovery gene panel to predict and model celiac disease. Conventional bioinformatics, gene set enrichment analysis (GSEA), and several machine learning and neural network techniques were used on a publicly available dataset (GSE164883). Machine learning and deep learning included C5, logistic regression, Bayesian network, discriminant analysis, KNN algorithm, LSVM, random trees, SVM, Tree-AS, XGBoost linear, XGBoost tree, CHAID, Quest, C&R tree, random forest, and neural network (multilayer perceptron). As a result, the gene panel predicted celiac disease with high accuracy (95-100%). Several pathogenic genes were identified, some of the immune checkpoint and immuno-oncology pathways. They included CASP3, CD86, CTLA4, FASLG, GZMB, IFNG, IL15RA, ITGAX, LAG3, MMP3, MUC1, MYD88, PRDM1, RGS1, etc. Among them, B and T lymphocyte associated (BTLA, CD272) was highlighted and validated at the protein level by immunohistochemistry in an independent series of cases. Celiac disease was characterized by high BTLA, expressed by inflammatory cells of the lamina propria. In conclusion, artificial intelligence predicted celiac disease using an autoimmune discovery gene panel.

The engineered probiotics for the treatment of chronic diseases: A systematic review

Engineered probiotics (EPs) are a group of probiotics whose proteome is manipulated by biotechnological techniques. EPs have attracted a lot of attention in recent researches for preventing and treating chronic diseases. The current study has been conducted to provide an overview regarding the EPs application in the treatment of chronic disease by a comprehensive systematic review of the published articles up to January 2022. To retrieve the related publications, three databases (PubMed/MEDLINE, Web of Sciences, and Scopus) were searched systematically. Finally, all human (n = 2) and animal (n = 37) studies were included. The included articles evaluated the effects of EPs on treatment of arthritis (n = 3), cancer (n = 2), autoimmune encephalomyelitis (EAE; n = 6), Parkinson disease (PD; n = 1), Alzheimer diseases (AD; n = 1), colitis (n = 11), celiac disease (n = 1), diabetes (n = 8) and cardiovascular disease (CVD; n = 6). Induction of oral tolerance (OT) is the most important mechanism of EPs action in the treatment of chronic disease. Providing oral vaccine and bioactive compounds are the other mechanisms of EPs action. PRACTICAL APPLICATIONS: The current systematic review gathered evidence about the application of EPs in the treatment of chronic diseases. Evidence suggests that EPs have very broad and potent effects in the treatment of chronic and even genetic diseases.

Hypo-osmotic stress induces the epithelial alarmin IL-33 in the colonic barrier of ulcerative colitis

Epithelial alarmins are gaining interest as therapeutic targets for chronic inflammation. The nuclear alarmin interleukin-33 (IL-33) is upregulated in the colonic mucosa of acute ulcerative colitis (UC) and may represent an early instigator of the inflammatory cascade. However, it is not clear what signals drive the expression of IL-33 in the colonic mucosa, nor is the exact role of IL-33 elucidated. We established an ex vivo model using endoscopic colonic biopsies from healthy controls and UC patients. Colonic biopsies exposed to hypo-osmotic medium induced a strong nuclear IL-33 expression in colonic crypts in both healthy controls and UC biopsies. Mucosal IL33 mRNA was also significantly increased following hypo-osmotic stress in healthy controls compared to non-stimulated biopsies (fold change 3.9, p-value < 0.02). We observed a modest induction of IL-33 in response to TGF-beta-1 stimulation, whereas responsiveness to inflammatory cytokines TNF and IFN-gamma was negligible. In conclusion our findings indicate that epithelial IL-33 is induced by hypo-osmotic stress, rather than prototypic proinflammatory cytokines in colonic ex vivo biopsies. This is a novel finding, linking a potent cytokine and alarmin of the innate immune system with cellular stress mechanisms and mucosal inflammation.

Inertness of Superoxide Dismutase Mimics Mn(II) Complexes Based on an Open-Chain Ligand, Bioactivity, and Detection in Intestinal Epithelial Cells

Oxidative stress is known to play a major role in the pathogenesis of inflammatory bowel diseases (IBDs), and, in particular, superoxide dismutase (SODs) defenses were shown to be weakened in patients suffering from IBDs. SOD mimics, also called SOD mimetics, as low-molecular-weight complexes reproducing the activity of SOD, constitute promising antioxidant catalytic metallodrugs in the context of IBDs. A Mn(II) complex SOD mimic (Mn1) based on an open-chain diaminoethane ligand exerting antioxidant and anti-inflammatory effects on an intestinal epithelial cellular model was shown to experience metal exchanges between the manganese center and metal ions present in the biological environment (such as Zn(II)) to some degrees. As the resulting complexes (mainly Zn(II)) were shown to be inactive, improving the kinetic inertness of Mn(II) complexes based on open-chain ligands is key to improve their bioactivity in a cellular context. We report here the study of three new Mn(II) complexes resulting from Mn1 functionalization with a cyclohexyl and/or a propyl group meant to limit, respectively, (a) metal exchanges and (b) deprotonation of an amine from the 1,2-diaminoethane central scaffold. The new manganese-based SOD mimics display a higher intrinsic SOD activity and also improved kinetic inertness in metal ion exchange processes (with Zn(II), Cu(II), Ni(II), and Co(II)). They were shown to provide anti-inflammatory and antioxidant effects in cells at lower doses than Mn1 (down to 10 μM). This improvement was due to their higher inertness against metal-assisted dissociation and not to different cellular overall accumulations. Based on its higher inertness, the SOD mimic containing both the propyl and the cyclohexyl moieties was suitable for intracellular detection and quantification by mass spectrometry, quantification, that was achieved by using a ¹³C-labeled Co-based analog of the SOD mimics as an external heavy standard.

Anti-Inflammatory, Antioxidant, and Healing-Promoting Effects of Aloe vera Extract in the Experimental Colitis in Rats

Background. Ulcerative colitis is a worldwide chronic gastrointestinal disease characterized by variable extensions of colon mucosal inflammation. The available drugs have an incomplete response with various side effects and socioeconomic impacts. Aloe barbadensis Miller (Aloe vera) is a well-known medicinal plant with diverse pharmacological and therapeutic activities. As a result, in the current study, Aloe vera was selected to evaluate its therapeutic effects on experimental colitis in rats. Methods. This study is intended to evaluate the possible beneficial effect of Aloe vera for the treatment of experimental colitis. Trinitrobenzenesulfonic acid (TNBS) was used to induce experimental colitis in 60 of 70 Wistar rats. The rats were grouped in 7 clusters including healthy control, negative, positive control (received sulfasalazine), and test groups treated with Aloe vera extracts via oral or rectal routes. Macroscopic and histologic factors as well as the biochemical parameters were evaluated on day 7. Results. In the present study, it was found that serum levels of tumor necrosis factor-α (75 vs. 44 pg./ml), interleukin-6 (41 vs. 21 pg/ml), and nitric oxide (24 vs. 6 μm/ml) in TNBS-induced untreated colitis treatment were significantly increased as compared to healthy control. Similar patterns were also observed in malondialdehyde (76.41 vs. 236.35 μg/mg) and myeloperoxidase (4.24 vs. 29.38 U/mg) in colonic tissue. Among different treatments, rectal administration of Aloe vera extract (400 mg/kg) exhibited the best result in which serum concentration of tumor necrosis factor-α (55 pg/ml), interleukin-6 (24 pg/ml), and nitric oxide (10 μm/ml) and the levels of malondialdehyde (102.67 μg/mg), as well as myeloperoxidase (12.29 U/mg) in colon tissue, were reduced as compared to the untreated group. Also, the body weight and colon weight/length ratios were more improved in the treated group with 400 mg/kg Aloe vera extract, rectally. Conclusion. Aloe vera extract exhibited a therapeutic effect in TNBS-induced colitis, and local, rectal administration of Aloe vera extract was more effective than oral administration.

Detection of Anti-Erythrocyte Antibodies in Dogs with Inflammatory Bowel Disease (IBD)

Several extra-intestinal manifestations, including immune-mediated cytopenias, are reported in human inflammatory bowel disease (IBD), whereas they are poorly documented in dogs. Hypothesizing that immune-mediated subclinical anemia can occur in canine IBD, the study aim was to evaluate the erythrogram and the presence of anti-RBC antibodies in dogs with IBD. IBD was diagnosed according to the following criteria: chronic gastrointestinal signs, ruling out of extra-intestinal diseases, no improvement with diet trial, histological evidence of inflammatory infiltration, and improvement after immunosuppressant therapy. Canine Chronic Enteropathy Clinical Activity Index (CCECAI) endoscopic and histopathological scores were assessed for each dog. Twenty-five dogs were enrolled, and each dog had a CBC evaluation prior to endoscopy. The CBC was performed using laser hematology analyzer and blood smears were carefully reviewed for the presence of nucleated RBC, anisocytosis, polychromasia, and Howell-Jolly bodies. IgG and IgM anti-RBC antibodies were evaluated with flow cytometry. A high frequency of positive cases for anti-RBC antibodies in dogs with IBD (17/25 dogs) was ascertained. Approximatively 50% of dogs showed some hematologic features of RBC regeneration in addition to hematologic findings consistent with chronic inflammation. Anti-RBC antibodies and signs of erythroid regeneration may suggest possible subclinical chronic immune-mediated hemolysis that can cause anemia in dogs with IBD, together with the chronic inflammation.

Oxidative Stress Does Not Influence Subjective Pain Sensation in Inflammatory Bowel Disease Patients

Oxidative stress (OS) has been proposed as a significant causative and propagating factor in inflammatory bowel diseases (IBDs). Modulation of OS is possible through antioxidants and inhibition of oxidizing enzymes. Thirty-one IBD patients and thirty-two controls were included in the study. The aim was to examine the levels of OS in colonic tissue of IBD requiring surgical intervention and control group, and their association with pain intensity. Total antioxidant capacity (TAC), superoxide dismutase (SOD) and catalase (CAT) activity, glutathione (GSH) and oxidized glutathione (GSSG) levels, and glutathione peroxidase (GPX) activity as markers of antioxidant defense were determined. Cyclooxygenases activities (Total COX, COX-1 and COX-2) were measured as prooxidant enzymes. Thiobarbituric acid reactive substances (TBARS) concentrations were measured to evaluate lipid peroxidation. Disease activity was assessed, and each subject filled out VAS and Laitinen's pain assessment scales. Correlation between the OS, pain intensity, disease activity parameters, C-reactive protein (CRP), number of stools passed daily, disease duration, and dietary habits was investigated. No TAC differences were found between the groups. A significant decrease of SOD activity and GSH and GSSG levels was seen in IBD patients vs. controls, while GPX activity was diminished significantly only in CD patients. CAT and COX-1 activity was increased, and COX-2 significantly decreased in IBD. TBARS were significantly higher in CD patients compared to control group. No correlation was found between pain scores, inflammatory status, disease activity, disease duration, or dietary habits and OS markers. In our study, OS did not influence pain sensation reported by IBD patients.

Effect of supplementing fava bean (Vicia faba L.) on ulcerative colitis and colonic mucosal DNA content in rats fed a high-sucrose diet

Ulcerative colitis (UC) is an inflammatory bowel disease with high morbidity. Acetic acid-induced damage of colonic mucosa in rats is a commonly used experimental animal model of UC. This research aimed to explore for the first time the ameliorative effect of dietary supplementation with fava bean on the incidence of UC in rats fed with sucrose containing diet. Rats were divided into five groups as follows: G1, control healthy rats; G2, colitic rats; G3, colitic rats fed diets containing 30% sucrose, G4, healthy rats fed diets containing 30% sucrose and G5, colitic rats fed diets containing 30% sucrose supplemented with dried ground fava bean. Colonic injury and inflammation were evaluated through a disturbance of oxidative biomarkers, a significant increase in inflammatory biomarkers and inflammatory cytokines, and histological abnormalities in colonic tissues accompanied by colonic mucosal DNA damage. Colitic rats fed on sucrose containing diet demonstrated additional histological, biochemical, and DNA alterations in colonic mucosa of rats. Dietary supplementation with dried ground fava bean significantly corrected the impaired oxidative and inflammatory biomarker levels and modulated histological features and DNA alterations. Finally, fava bean attenuated the oxidative damage and colonic injury induced by acetic acid, which confirmed its high anti-oxidant and anti-incendiary properties.

Evaluation of glutathione reductase activity in colon tissue of patients with irritable bowel syndrome

OBJECTIVES

Irritable bowel syndrome (IBS) is known as one of the most common irritating gastrointestinal disorders. The mechanism behind IBS is still under investigation and it is thought that it may arose from multi factors among which free radicals have been previously mentioned. Studies have found an association between oxidative stress and IBS; however, little is known about the mechanisms and oxidative stress components status during IBS. One of the key factors playing a central role in oxidative stress network is glutathione reductase (GR). Here we report the GR activity in colon tissue samples during IBS to explore a part of contributing components in IBS pathogenesis.

METHODS

The GR enzyme activity was measured in 15 active IBS colon biopsy samples and was compared to our best available age and sex matched colorectal tissue samples from normal marginal tissue of resected colon cancers (n=15). The enzyme activity in the two groups was determined and compared using a commercial GR Assay Kit (Cayman chemical).

RESULTS

A significant decrease in GR activity among IBS tissue samples was observed compared to anatomically normal marginal colon tissue samples (p=0.007).

CONCLUSIONS

Lower GR activity may increase oxidized glutathione there by in turn could contribute as a main component in oxidative stress network. The lower GR activity results in hampered defense mechanism against produced free radical species. This finding may clarify a part of IBS pathogenesis.

Protective Effect of Tuna Bioactive Peptide on Dextran Sulfate Sodium-Induced Colitis in Mice

Bioactive peptides isolated from marine organisms have shown to have potential anti-inflammatory effects. This study aimed to investigate the intestinal protection effect of low molecular peptides (Mw < 1 kDa) produced through enzymatic hydrolysis of tuna processing waste (tuna bioactive peptides (TBP)) on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in BALB/c mice. Here, we randomly divided twenty-four male BALB/c mice into four groups: (i) normal (untreated), (ii) DSS-induced model colitis, (iii) low dose TBP+DSS-treated (200 mg/kg/d), and (iv) high dose TBP+DSS-treated groups (500 mg/kg/d). The results showed that TBP significantly reduced mice weight loss and improved morphological and pathological characteristics of colon tissues. In addition, it increased the activities of antioxidant enzymes (SOD and GSH-Px) and decreased inflammatory factors (LPS, IL-6, and TNF-α) expression. TBP increased the gene expression levels of some tight junction (TJ) proteins. Moreover, TBP increased the short-chain fatty acids (SCFAs) levels and the diversity and imbalance of intestinal flora. Therefore, TBP plays some protective roles in the intestinal tract by enhancing antioxidant and anti-inflammatory abilities of the body, improving the intestinal barrier and metabolic abnormalities, and adjusting intestinal flora imbalance.

Oxidative Stress in the Pathogenesis of Crohn's Disease and the Interconnection with Immunological Response, Microbiota, External Environmental Factors, and Epigenetics

Inflammatory bowel disease (IBD) is a complex multifactorial disorder in which external and environmental factors have a large influence on its onset and development, especially in genetically susceptible individuals. Crohn’s disease (CD), one of the two types of IBD, is characterized by transmural inflammation, which is most frequently located in the region of the terminal ileum. Oxidative stress, caused by an overabundance of reactive oxygen species, is present locally and systemically in patients with CD and appears to be associated with the well-described imbalanced immune response and dysbiosis in the disease. Oxidative stress could also underlie some of the environmental risk factors proposed for CD. Although the exact etiopathology of CD remains unknown, the key role of oxidative stress in the pathogenesis of CD is extensively recognized. Epigenetics can provide a link between environmental factors and genetics, and numerous epigenetic changes associated with certain environmental risk factors, microbiota, and inflammation are reported in CD. Further attention needs to be focused on whether these epigenetic changes also have a primary role in the pathogenesis of CD, along with oxidative stress.