Role of oxidative stress and antioxidant enzymes in Crohn’s disease. Biochem Soc Trans. 2011;39:1102-1106. [PMID: 21787356 DOI: 10.1042/bst0391102]

Oral chitosan-cyclodextrin "shell-core" nanoparticles co-loaded Rhein and chlorogenic acid for ulcerative colitis treatment

The food-derived ingredients Rhein (RH) and chlorogenic acid (CGA) have DEMONSTRATED a potential synergistic effect in the treatment of ulcerative colitis (UC) through their anti-inflammatory and antioxidant properties. However, the oral co-delivery of RH and CGA faces challenges such as differences in hydrophilicity and hydrophobicity, gastrointestinal instability, and inadequate colonic targeting. To address these issues, shell-core nanoparticles were developed for the co-encapsulation of RH and CGA (CP@CGA-FA/TA@RH NPs). These nanoparticles utilize cyclodextrin-based polymers and folate-amantadine polymers to form a supramolecular core that targets macrophages for anti-inflammatory action with RH, while chitosan cross-link to CGA in the outer shell provides microenvironment-sensitive antioxidant release. The results indicate that CP@CGA-FA/TA@RH NPs could effectively inhibit the classical TLR4/MyD88/NF-κB-mediated anti-inflammatory pathway and activate the Nrf2/HO-1-mediated antioxidant pathway, offering a novel approach to UC treatment. Q-value analysis confirms the substantial co-medication effect between RH and CGA. This study is the first to develop a nano-system combining two food-derived ingredients for the integrated treatment of UC.

Hyperbaric Oxygen Therapy in the Treatment of Crohn's Disease

Background/Objectives: Our study describes hyperbaric oxygen therapy (HBOT) as an additional therapy in the conservative treatment of Crohn's disease (CD) and its benefit in the early postoperative period to prevent surgical complications and improve gastrointestinal motility. Methods: This retrospective study evaluated HBOT in patients hospitalized at the Clinical Hospital Center Split for complications of CD between 2015 and 2020. Patients (N = 61) aged 19 to 67 with perianal fistulas, abscesses, fistulas, obstruction, stenosis, or bleeding were included, excluding those with ulcerative colitis or requiring intensive care. Patients were retrospectively divided into conservatively and surgically treated groups, and HBOT was administered over 15-25 days, with treatment lasting 60 min at 2.2 absolute atmospheres (ATA). We analyzed treatment outcomes between the HBOT-treated surgical and conservative groups and compared patients treated with HBOT to a cohort from the preceding five years who did not receive HBOT. Results: We treated 61 CD patients with HBOT, including 34 conservatively and 27 surgically treated patients. HBOT significantly reduced disease activity indices (311.7 ± 59.1 vs. 114 ± 29.8; 203.6 ± 24.1 vs. 83.8 ± 15, for conservatively treated patients, and 352.8 ± 45.7 vs. 109 ± 22.8; 270.4 ± 19.7 vs. 140.3 ± 10.6 for surgically treated patients) and accelerated bowel peristalsis recovery, with 94.1% of conservatively treated patients achieving remission. Comparison with a historical cohort showed faster recovery and improved outcomes in the HBOT group. Conclusions: HBOT is useful in postponing or avoiding surgical treatment, and in operated patients, it improves postoperative recovery and reduces the rate of postoperative complications.

Protective Effects of Peanut Sprouts from a Smart Farming System on the Barrier Function of Human Epithelial Cells

Inflammatory bowel disease, including Crohn's disease and ulcerative colitis, poses an emerging threat as it can lead to colorectal cancer, thrombosis, and other chronic conditions. The present study demonstrated the protective effects of peanut sprout extracts (PSEs) prepared from day 2 to day 7 of germination against lipopolysaccharide (LPS)-induced epithelial barrier breakdown. Although the peanut sprout length increased in a time-dependent manner from day 1 to day 7, the extraction yields remained relatively consistent from day 2 to day 7. With regard to antioxidant activities, the PSE from day 6 of germination exhibited the highest oxidative radical scavenging activity and total phenolic content. Similarly, it showed remarkable anti-permeability effects in LPS-stimulated Caco-2 cells and suppressed the degradation and dissociation of junctional markers (e.g., ZO-1 and E-cadherin) at cell-cell junctions. Collectively, these data demonstrate that PSE from day 6 of germination can be used as a functional food resource to reduce inflammatory barrier dysfunction.

The role of mitochondrial DNA copy number in autoimmune disease: a bidirectional two sample mendelian randomization study

Background

Mitochondrial DNA (mtDNA) plays an important role in autoimmune diseases (AD), yet the relationship between mitochondria and autoimmune disease is controversial. This study employed bidirectional Mendelian randomization (MR) to explore the causal relationship between mtDNA copy number and 13 ADs (including ankylosing spondylitis [AS], Crohn's disease [CD], juvenile rheumatoid arthritis [JRA], polymyalgia rheumatica [PMR], psoriasis [PSO], rheumatoid arthritis [RA], Sjogren's syndrome [SS], systemic lupus erythematosus [SLE], thyrotoxicosis, type 1 diabetes mellitus [T1DM], ulcerative colitis [UC], and vitiligo).

Methods

A two-sample MR analysis was performed to assess the causal relationship between mtDNA copy number and AD. Genome-wide association study (GWAS) for mtDNA copy number were obtained from the UK Biobank (UKBB), while those associated with AD were sourced from the FinnGen Biobank. Inverse variance weighting (IVW) was the primary analysis method, complemented by three sensitivity analyses (MR-Egger, weighted median, weighted mode) to validate the results.

Results

IVW MR analysis identified significant associations between mtDNA copy number and CD (OR=2.51, 95% CI 1.56-4.22, P<0.001), JRA (OR=1.87, 95% CI 1.17-7.65, P=0.022), RA (OR=1.71, 95%CI 1.18-2.47, P=0.004), thyrotoxicosis (OR=0.51, 95% CI0.27-0.96, P=0.038), and T1DM (OR=0.51, 95% CI 0.27-0.96, P=0.038). Sensitivity analyses indicated no horizontal pleiotropy.

Conclusions

Our study revealed a potential causal relationship between mtDNA copy number and ADs, indicating that these markers may be relevant in exploring new therapeutic approaches.

Hypoxia-Mediated Upregulation of Xanthine Oxidoreductase Causes DNA Damage of Colonic Epithelial Cells in Colitis

Xanthine oxidoreductase (XOR) serves as the primary source of hydrogen peroxide and superoxide anions in the intestinal mucosa. However, its specific contribution to the progression of colonic disease remains unclear. In this study, we investigated the role of XOR in ulcerative colitis (UC) and attempted to identify the underlying mechanisms. We used the dextran sulfate sodium (DSS)-induced mouse model to mimic UC and observed that XOR inhibitors, allopurinol and diphenyleneiodonium sulfate (DPI), significantly alleviated UC in mice. In addition, treatment with cobalt chloride (CoCl2) and 1% O2 increased the expression of XOR and induced DNA oxidative damage in colonic epithelial cells. Furthermore, we identified that XOR accumulation in the nucleus may directly cause DNA oxidative damage and regulates HIF1α protein levels. In addition, allopurinol effectively protected colon epithelial cells from CoCl2-induced DNA damage. Altogether, our data provided evidence that XOR could induce DNA damage under hypoxic conditions, indicating a significant role of XOR in the initiation and early development of colitis-associated colorectal cancer (CAC).

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.

Insights into the Role of Glutathione Peroxidase 3 in Non-Neoplastic Diseases

Reactive oxygen species (ROSs) are byproducts of normal cellular metabolism and play pivotal roles in various physiological processes. Disruptions in the balance between ROS levels and the body's antioxidant defenses can lead to the development of numerous diseases. Glutathione peroxidase 3 (GPX3), a key component of the body's antioxidant system, is an oxidoreductase enzyme. GPX3 mitigates oxidative damage by catalyzing the conversion of hydrogen peroxide into water. Beyond its antioxidant function, GPX3 is vital in regulating metabolism, modulating cell growth, inducing apoptosis and facilitating signal transduction. It also serves as a significant tumor suppressor in various cancers. Recent studies have revealed aberrant expression of GPX3 in several non-neoplastic diseases, associating it with multiple pathological processes. This review synthesizes the current understanding of GPX3 expression and regulation, highlighting its extensive roles in noncancerous diseases. Additionally, this paper evaluates the potential of GPX3 as a diagnostic biomarker and explores emerging therapeutic strategies targeting this enzyme, offering potential avenues for future clinical treatment of non-neoplastic conditions.

Antioxidant insights: investigating the protective role of oxidative balance in inflammatory bowel disease

Background

Limited studies have investigated the relationship between systemic oxidative stress and inflammatory bowel disease (IBD). The purpose of this study was to explore the relationship between oxidative balance score (OBS) and IBD.

Methods

We included 175,808 participants from the UK Biobank database from 2006 to 2010. OBS scores were calculated based on 22 lifestyle and dietary factors. Multiple variable Cox proportional regression models, as well as gender stratification and subgroup analysis, were utilized to investigate the relationship between OBS and IBD.

Results

There is a significant negative correlation between OBS and the occurrence of IBD, ulcerative colitis (UC), and Crohn's disease (CD). Additionally, OBS is significantly negatively correlated with intestinal obstruction in CD patients. Gender stratified analysis suggest a significant correlation between OBS and CD in female patients, particularly pronounced in those under 60 years old. Sensitivity analysis indicates a significant negative correlation between lifestyle-related OBS and diet-related OBS with the occurrence of CD in females, diet-related OBS is negatively correlated with CD in males.

Conclusion

OBS showed a significant negative correlation with IBD, especially in female CD patients. This study underscores the importance of antioxidant diet and lifestyle, which may provide a greater advantage for female CD patients.

The Role of Anthocyanins in Alleviating Intestinal Diseases: A Mini Review

Anthocyanins are phytonutrients with physiological activity belonging to the flavonoid family whose transport and absorption in the human body follow specific pathways. In the upper gastrointestinal tract, anthocyanins are rarely absorbed intact by active transporters, with most reaching the colon, where bacteria convert them into metabolites. There is mounting evidence that anthocyanins can be used for prevention and treatment of intestinal diseases, including inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), and colorectal cancer (CRC), through the protective function on the intestinal epithelial barrier, immunomodulation, antioxidants, and gut microbiota metabolism. Dietary anthocyanins are summarized in this comprehensive review with respect to their classification and structure as well as their absorption and transport mechanisms within the gastrointestinal tract. Additionally, the review delves into the role and mechanism of anthocyanins in treating common intestinal diseases. These insights will deepen our understanding of the potential benefits of natural anthocyanins for intestinal disorders.

Brucine Entrapped Titanium Oxide Nanoparticle for Anticancer Treatment: An In Vitro Study

Backgroundand Objective. The public's health has been seriously threatened by cervical cancer during recent times. In terms of newly diagnosed cases worldwide, it ranks as the ninth most prevalent malignancy. Multiple investigations have proven that nanoparticles can effectively combat cancer due to their small dimensions and extensive surface area. In the meantime, bioactive compounds which are biocompatible are being loaded onto nanoparticles to promote cancer therapy. The current study investigates the anticancerous potential of Brucine-entrapped titanium oxide nanoparticles (TiO2 NPs) in cervical cancer cell line (HeLa). Materials and Methods. The physiochemical, structural, and morphological aspects of Brucine-entrapped TiO2 NPs were evaluated by UV-visible spectrophotometer, Fourier transform-infrared spectroscopy (FT-IR), dynamic light scattering (DLS), scanning electron microscopy (SEM), and energy dispersive X-ray (EDAX). The cytotoxic effect against the HeLa cell line was assessed using a tetrazolium-based colorimetric assay (MTT), a trypan blue exclusion (TBE) assay, phase contrast microscopic analysis, and a fluorescence assay including ROS and DAPI staining. Furthermore, estimation of antioxidant markers includes catalase (CAT), glutathione (GSH), and superoxide dismutase (SOD). Results. The UV spectrum at 266 nm revealed the formation of TiO NPs. The FT-IR peaks confirmed the effective entrapment of brucine with TiO2 NPs. The average size (100.0 nm) of Brucine-entrapped TiO2 NPs was revealed in DLS analysis. The micrograph of the SEM revealed the formation of ellipsoidal to tetragonal-shaped NPs. The Ti, O, and C signals were observed in EDAX. In MTT assay, Brucine-entrapped TiO2 NPs showed inhibition of cell proliferation in a dose-wise manner and IC50 was noticed at the concentration of 30 µg/mL. The percentage of viable cells gradually reduced in the trypan blue exclusion assay. The phase contrast microscopic analysis of Brucine-entrapped TiO2 NP-treated cells showed cell shrinkage, cell wall deterioration, and cell blebbing. The intracellular ROS level was increased in a dose-wise manner when compared to control cells in ROS staining. The condensed nuclei and apoptotic cells were increased in treated cells, as noted in DAPI staining. In treated cells, the antioxidant markers such as CAT, GSH, and SOD levels were substantially lower compared to the control cells. Conclusion. The synthesized Brucine entrapped TiO2 NPs exhibited remarkable anticancer activity against the HeLa cell line.

Antioxidant nanozymes as next-generation therapeutics to free radical-mediated inflammatory diseases: A comprehensive review

Recent developments in exploring the biological enzyme mimicking properties in nanozymes have opened a separate avenue, which provides a suitable alternative to the natural antioxidants and enzymes. Due to high and tunable catalytic activity, low cost of synthesis, easy surface modification, and good biocompatibility, nanozymes have garnered significant research interest globally. Several inorganic nanomaterials have been investigated to exhibit catalytic activities of some of the key natural enzymes, including superoxide dismutase (SOD), catalase, glutathione peroxidase, peroxidase, and oxidase, etc. These nanozymes are used for diverse biomedical applications including therapeutics, imaging, and biosensing in various cells/tissues and animal models. In particular, inflammation-related diseases are closely associated with reactive oxygen and reactive nitrogen species, and therefore effective antioxidants could be excellent therapeutics due to their free radical scavenging ability. Although biological enzymes and other artificial antioxidants could perform well in scavenging the reactive oxygen and nitrogen species, however, suffer from several drawbacks such as the requirement of strict physiological conditions for enzymatic activity, limited stability in the environment beyond their optimum pH and temperature, and high cost of synthesis, purification, and storage make then unattractive for broad-spectrum applications. Therefore, this review systematically and comprehensively presents the free radical-mediated evolution of various inflammatory diseases (inflammatory bowel disease, mammary gland fibrosis, and inflammation, acute injury of the liver and kidney, mammary fibrosis, and cerebral ischemic stroke reperfusion) and their mitigation by various antioxidant nanozymes in the biological system. The mechanism of free radical scavenging by antioxidant nanozymes under in vitro and in vivo experimental models and catalytic efficiency comparison with corresponding natural enzymes has also been presented.

Digestion-resistant whey peptides promote antioxidant effect on Caco-2 cells

Enteric endothelial cells are the first structure to come in contact with digested food and may suffer oxidative damage by innumerous exogenous factors. Although peptides derived from whey digestion have presented antioxidant potential, little is known regarding antioxidant pathways activation in Caco-2 cell line model. Hence, we evaluated the ability to form whey peptides resistant to simulated gastrointestinal digestive processes, with potential antioxidant activity on gastrointestinal cells and associated with sequence structure and activity. Using the INFOGEST method of simulated static digestion, we achieved 35.2% proteolysis, with formation of peptides of low molecular mass (<600 Da) evaluated by FPLC. The digestion-resistant peptides showed a high proportion of hydrophobic and acidic amino acids, but with average surface hydrophobicity. We identified 24 peptide sequences, mainly originated from β-lactoglobulin, that exhibit various bioactivities. Structurally, the sequenced peptides predominantly contained the amino acids lysine and valine in the N-terminal region, and tyrosine in the C-terminal region, which are known to exhibit antioxidant properties. The antioxidant activity of the peptide digests was on average twice as potent as that of the protein isolates for the same concentration, as evaluated by ABTS, DPPH and ORAC. Evaluation of biological activity in Caco-2 intestinal cells, stimulated with hydrogen peroxide, showed that they attenuated the production of reactive oxygen species and prevented GSH reduction and SOD activity increase. Caco-2 cells were not responsive to nitric oxide secretion. This study suggests that whey peptides formed during gastric digestion exhibit biological antioxidant activity, without the need for previously hydrolysis with exogenous enzymes for supplement application. The study's primary contribution was demonstrating the antioxidant activity of whey peptides in maintaining the gastrointestinal epithelial cells, potentially preventing oxidative stress that affects the digestive system.

Targeted serum proteomics of longitudinal samples from newly diagnosed youth with type 1 diabetes distinguishes markers of disease and C-peptide trajectory

AIMS/HYPOTHESIS

There is a growing need for markers that could help indicate the decline in beta cell function and recognise the need and efficacy of intervention in type 1 diabetes. Measurements of suitably selected serum markers could potentially provide a non-invasive and easily applicable solution to this challenge. Accordingly, we evaluated a broad panel of proteins previously associated with type 1 diabetes in serum from newly diagnosed individuals during the first year from diagnosis. To uncover associations with beta cell function, comparisons were made between these targeted proteomics measurements and changes in fasting C-peptide levels. To further distinguish proteins linked with the disease status, comparisons were made with measurements of the protein targets in age- and sex-matched autoantibody-negative unaffected family members (UFMs).

METHODS

Selected reaction monitoring (SRM) mass spectrometry analyses of serum, targeting 85 type 1 diabetes-associated proteins, were made. Sera from individuals diagnosed under 18 years (n=86) were drawn within 6 weeks of diagnosis and at 3, 6 and 12 months afterwards (288 samples in total). The SRM data were compared with fasting C-peptide/glucose data, which was interpreted as a measure of beta cell function. The protein data were further compared with cross-sectional SRM measurements from UFMs (n=194).

RESULTS

Eleven proteins had statistically significant associations with fasting C-peptide/glucose. Of these, apolipoprotein L1 and glutathione peroxidase 3 (GPX3) displayed the strongest positive and inverse associations, respectively. Changes in GPX3 levels during the first year after diagnosis indicated future fasting C-peptide/glucose levels. In addition, differences in the levels of 13 proteins were observed between the individuals with type 1 diabetes and the matched UFMs. These included GPX3, transthyretin, prothrombin, apolipoprotein C1 and members of the IGF family.

CONCLUSIONS/INTERPRETATION

The association of several targeted proteins with fasting C-peptide/glucose levels in the first year after diagnosis suggests their connection with the underlying changes accompanying alterations in beta cell function in type 1 diabetes. Moreover, the direction of change in GPX3 during the first year was indicative of subsequent fasting C-peptide/glucose levels, and supports further investigation of this and other serum protein measurements in future studies of beta cell function in type 1 diabetes.

Oxidative stress, hormones, and effects of natural antioxidants on intestinal inflammation in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic, relapsing gastrointestinal (GI) disorder characterized by intestinal inflammation. The etiology of IBD is multifactorial and results from a complex interplay between mucosal immunity, environmental factors, and host genetics. Future therapeutics for GI disorders, including IBD, that are driven by oxidative stress require a greater understanding of the cellular and molecular mechanisms mediated by reactive oxygen species (ROS). In the GI tract, oxidative stressors include infections and pro-inflammatory responses, which boost ROS generation by promoting the production of pro-inflammatory cytokines. Nuclear factor kappa B (NF-κB) and nuclear factor erythroid 2-related factor 2 (Nrf2) represent two important signaling pathways in intestinal immune cells that regulate numerous physiological processes, including anti-inflammatory and antioxidant activities. Natural antioxidant compounds exhibit ROS scavenging and increase antioxidant defense capacity to inhibit pro-oxidative enzymes, which may be useful in IBD treatment. In this review, we discuss various polyphenolic substances (such as resveratrol, curcumin, quercetin, green tea flavonoids, caffeic acid phenethyl ester, luteolin, xanthohumol, genistein, alpinetin, proanthocyanidins, anthocyanins, silymarin), phenolic compounds including thymol, alkaloids such as berberine, storage polysaccharides such as tamarind xyloglucan, and other phytochemicals represented by isothiocyanate sulforaphane and food/spices (such as ginger, flaxseed oil), as well as antioxidant hormones like melatonin that target cellular signaling pathways to reduce intestinal inflammation occurring with IBD.

Blood Selenium and Serum Glutathione Peroxidase Levels Were Associated with Serum β-Amyloid in Older Adults

BACKGROUND

Studies have established the association between blood β-amyloid (Aβ) levels and Alzheimer's disease, but population-based studies concerning the association between selenium (Se) and Aβ levels in blood samples are very limited. Therefore, we explored the association in an elderly population with Se status and serum Aβ measures.

METHODS

A cross-sectional study on 469 elderly individuals from four rural counties with diverse soil Se levels was carried out. Fasting blood Se, serum selenoprotein P (SELENOP), and glutathione peroxidase (GPX), serum Aβ42, and Aβ40 were measured. Quantile regression models were used to determine the associations of blood Se, serum GPX, and SELENOP with Aβ levels.

RESULTS

Significant negative associations were observed between blood Se and serum Aβ42 and Aβ40 levels at all percentiles (P < 0.05). The associations were generally stronger at higher Aβ42 and Aβ40 percentiles than lower Aβ42 and Aβ40 percentiles. Blood Se was positively associated with serum Aβ42/Aβ40 ratio at 25th, 50th, and 75th percentiles. Significant positive associations were observed between serum GPX and Aβ42 and Aβ40 levels at all percentiles (P < 0.05). The positive associations were generally stronger at higher Aβ42 and Aβ40 percentiles than at lower percentiles. Serum GPX was negatively associated with Aβ42/Aβ40 ratio at 25th, 50th, 75th, and 95th percentiles. No associations with serum SELENOP and Aβ levels were observed.

CONCLUSIONS

Our results suggest that higher Se levels are associated with lower serum Aβ42 and Aβ40 levels and with higher Aβ42/Aβ40 ratio, and the results are specific for different selenoproteins.

Potential of algae-derived alginate oligosaccharides and β-glucan to counter inflammation in adult zebrafish intestine

Alginate oligosaccharides (AOS) are natural bioactive compounds with anti-inflammatory properties. We performed a feeding trial employing a zebrafish (Danio rerio) model of soybean-induced intestinal inflammation. Five groups of fish were fed different diets: a control (CT) diet, a soybean meal (SBM) diet, a soybean meal+β-glucan (BG) diet and 2 soybean meal+AOS diets (alginate products differing in the content of low molecular weight fractions - AL, with 31% < 3kDa and AH, with 3% < 3kDa). We analyzed the intestinal transcriptomic and plasma metabolomic profiles of the study groups. In addition, we assessed the expression of inflammatory marker genes and histological alterations in the intestine. Dietary algal β-(1, 3)-glucan and AOS were able to bring the expression of certain inflammatory genes altered by dietary SBM to a level similar to that in the control group. Intestinal transcriptomic analysis indicated that dietary SBM changed the expression of genes linked to inflammation, endoplasmic reticulum, reproduction and cell motility. The AL diet suppressed the expression of genes related to complement activation, inflammatory and humoral response, which can likely have an inflammation alleviation effect. On the other hand, the AH diet reduced the expression of genes, causing an enrichment of negative regulation of immune system process. The BG diet suppressed several immune genes linked to the endopeptidase activity and proteolysis. The plasma metabolomic profile further revealed that dietary SBM can alter inflammation-linked metabolites such as itaconic acid, taurochenodeoxycholic acid and enriched the arginine biosynthesis pathway. The diet AL helped in elevating one of the short chain fatty acids, namely 2-hydroxybutyric acid while the BG diet increased the abundance of a vitamin, pantothenic acid. Histological evaluation revealed the advantage of the AL diet: it increased the goblet cell number and length of villi of the intestinal mucosa. Overall, our results indicate that dietary AOS with an appropriate amount of < 3kDa can stall the inflammatory responses in zebrafish.

Recent Perspective of Lactobacillus in Reducing Oxidative Stress to Prevent Disease

During oxidative stress, an important factor in the development of many diseases, cellular oxidative and antioxidant activities are imbalanced due to various internal and external factors such as inflammation or diet. The administration of probiotic Lactobacillus strains has been shown to confer a range of antibacterial, anti-inflammatory, antioxidant, and immunomodulatory effects in the host. This review focuses on the potential role of oxidative stress in inflammatory bowel diseases (IBD), cancer, and liver-related diseases in the context of preventive and therapeutic effects associated with Lactobacillus. This article reviews studies in cell lines and animal models as well as some clinical population reports that suggest that Lactobacillus could alleviate basic symptoms and related abnormal indicators of IBD, cancers, and liver damage, and covers evidence supporting a role for the Nrf2, NF-κB, and MAPK signaling pathways in the effects of Lactobacillus in alleviating inflammation, oxidative stress, aberrant cell proliferation, and apoptosis. This review also discusses the unmet needs and future directions in probiotic Lactobacillus research including more extensive mechanistic analyses and more clinical trials for Lactobacillus-based treatments.

Gold nanoparticles-embedded ceria with enhanced antioxidant activities for treating inflammatory bowel disease

The excessive reactive oxygen species (ROS) is a hallmark associated with the initiation and progression of inflammatory bowel disease (IBD), which execrably form a vicious cycle of ROS and inflammation to continually promote disease progression. Here, the gold nanoparticles-embedded ceria nanoparticles (Au/CeO₂) with enhanced antioxidant activities are designed to block this cycle reaction for treating IBD by scavenging overproduced ROS. The Au/CeO₂ with core-shell and porous structure exhibits significantly higher enzymatic catalytic activities compared with commercial ceria nanoparticles, likely due to the effective exposure of catalytic sites, higher content of Ce (III) and oxygen vacancy, and accelerated reduction from Ce (IV) to Ce (III). Being coated with negatively-charged hyaluronic acid, the Au/CeO₂@HA facilitates accumulation in inflamed colon tissues via oral administration, reduces pro-inflammatory cytokines, and effectively alleviates colon injury in colitis mice. Overall, the Au/CeO₂@HA with good biocompatibility is a promising nano-therapeutic for treating IBD.

The Genetic Diversity and Dysfunctionality of Catalase Associated with a Worse Outcome in Crohn's Disease

Chronic gut inflammation in Crohn’s disease (CD) is associated with an increase in oxidative stress and an imbalance of antioxidant enzymes. We have previously shown that catalase (CAT) activity is permanently inhibited by CD. The purpose of the study was to determine whether there is any relationship between the single nucleotide polymorphisms (SNPs) in the CAT enzyme and the potential risk of CD associated with high levels of oxidative stress. Additionally, we used protein and regulation analyses to determine what causes long-term CAT inhibition in peripheral white mononuclear cells (PWMCs) in both active and inactive CD. We first used a retrospective cohort of 598 patients with CD and 625 age-matched healthy controls (ENEIDA registry) for the genotype analysis. A second human cohort was used to study the functional and regulatory mechanisms of CAT in CD. We isolated PWMCs from CD patients at the onset of the disease (naïve CD patients). In the genotype-association SNP analysis, the CAT SNPs rs1001179, rs475043, and rs525938 showed a significant association with CD (p < 0.001). Smoking CD patients with the CAT SNP rs475043 A/G genotype had significantly more often penetrating disease (p = 0.009). The gene expression and protein levels of CAT were permanently reduced in the active and inactive CD patients. The inhibition of CAT activity in the PWMCs of the CD patients was related to a low concentration of CAT protein caused by the downregulation of CAT-gene transcription. Our study suggests an association between CAT SNPs and the risk of CD that may explain permanent CAT inhibition in CD patients together with low CAT gene and protein expression.

Insights into diet-associated oxidative pathomechanisms in inflammatory bowel disease and protective effects of functional amino acids

There has been a substantial rise in the incidence and prevalence of clinical patients presenting with inflammatory bowel disease (IBD), which includes Crohn's disease and ulcerative colitis. Accumulating evidence has corroborated the view that dietary factors (particularly diets with high levels of saturated fat or sugar) are involved in the development and progression of IBD, which is predominately associated with changes in the composition of the gut microbiota and an increase in the generation of reactive oxygen species. Notably, the ecological imbalance of the gut microbiome exacerbates oxidative stress and inflammatory responses, leading to perturbations of the intestinal redox balance and immunity, as well as mucosal integrity. Recent findings have revealed that functional amino acids, including L-glutamine, glycine, L-arginine, L-histidine, L-tryptophan, and hydroxyproline, are effectively implicated in the maintenance of intestinal redox and immune homeostasis. These amino acids and their metabolites have oxygen free-radical scavenging and inflammation-relieving properties, and they participate in modulation of the microbial community and the metabolites in the gut. The principal focus of this article is a review of recent advances in the oxidative pathomechanisms of IBD development and progression in relation to dietary factors, with a particular emphasis on the redox and signal transduction mechanisms of host cells in response to unbalanced diets and enterobacteria. In addition, an update on current understanding of the protective effects of functional amino acids against IBD, together with the underlying mechanisms for this protection, have been provided.

Traditional Chinese Medicine and Natural Products: Potential Approaches for Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a rare, recurrent, and intractable inflammation obstruction of the stomach tract, usually accompanied by inflammation of cell proliferation and inflammation of the colon and carries a particular cause of inflammation. The clinical use of drugs in western countries affects IBD treatment, but various adverse effects and high prices limit their application. For these reasons, Traditional Chinese Medicine (TCM) is more advantageous in treating IBD. This paper reviews the mechanism and research status of TCM and natural products in IBD treatment by analyzing the relevant literature to provide a scientific and theoretical basis for IBD treatment.

Catalase Inhibition by Aminoalkanol Derivatives with Potential Anti-Cancer Activity-In Vitro and In Silico Studies Using Capillary Electrophoresis Method

In this work, the investigation of type and inhibitory strength of catalase by two pairs of aminoalkanol derivatives (1,7 diEthyl- and 1,7-diMethyl-8,9-diphenyl-4-azatricyclo (5.2.1.02.6) dec-8-ene- 3,5,10-trione) has been presented. The obtained results allowed for the determination of all kinetic parameters (Km, Vmax, slope angles of Lineweaver-Burk plots, Ki and IC50) on the basis of which it was shown that all four aminoalkanol derivatives are competitive inhibitors of catalase. However, the strength of action of each of them depends on the type of substituents present in the main structure of the molecule. Subtle differences in the potency of individual derivatives were possible to detect thanks to the developed, sensitive method of capillary electrophoresis, which allowed simultaneous monitoring of the mutual changes in the concentrations of substrates and products of the reaction catalyzed by the enzyme. Detailed values of kinetic parameters showed that all derivatives are weak inhibitors of catalase, which in this case is a big advantage because each inhibition of catalase activity is associated with a greater amount of accumulated, harmful reactive oxygen species. The results of docking studies also show the convergence of the binding energies values of individual inhibitors with all kinetic parameters of the investigated catalase inhibition and thus additionally confirm the weak inhibitory strength of all four aminoalkanol derivatives.

Recent Advances in Understanding Nrf2 Agonism and Its Potential Clinical Application to Metabolic and Inflammatory Diseases

Oxidative stress is a major component of cell damage and cell fat, and as such, it occupies a central position in the pathogenesis of metabolic disease. Nuclear factor-erythroid-derived 2-related factor 2 (Nrf2), a key transcription factor that coordinates expression of genes encoding antioxidant and detoxifying enzymes, is regulated primarily by Kelch-like ECH-associated protein 1 (Keap1). However, involvement of the Keap1–Nrf2 pathway in tissue and organism homeostasis goes far beyond protection from cellular stress. In this review, we focus on evidence for Nrf2 pathway dysfunction during development of several metabolic/inflammatory disorders, including diabetes and diabetic complications, obesity, inflammatory bowel disease, and autoimmune diseases. We also review the beneficial role of current molecular Nrf2 agonists and summarize their use in ongoing clinical trials. We conclude that Nrf2 is a promising target for regulation of numerous diseases associated with oxidative stress and inflammation. However, more studies are needed to explore the role of Nrf2 in the pathogenesis of metabolic/inflammatory diseases and to review safety implications before therapeutic use in clinical practice.

Parabacteroides distasonis: intriguing aerotolerant gut anaerobe with emerging antimicrobial resistance and pathogenic and probiotic roles in human health

Parabacteroides distasonis is the type strain for the genus Parabacteroides, a group of gram-negative anaerobic bacteria that commonly colonize the gastrointestinal tract of numerous species. First isolated in the 1930s from a clinical specimen as Bacteroides distasonis, the strain was re-classified to form the new genus Parabacteroides in 2006. Currently, the genus consists of 15 species, 10 of which are listed as 'validly named' (P. acidifaciens, P. chartae, P. chinchillae, P. chongii, P. distasonis, P. faecis, P. goldsteinii, P. gordonii, P. johnsonii, and P. merdae) and 5 'not validly named' (P. bouchesdurhonensis, P. massiliensis, P. pacaensis, P. provencensis, and P. timonensis) by the List of Prokaryotic names with Standing in Nomenclature. The Parabacteroides genus has been associated with reports of both beneficial and pathogenic effects in human health. Herein, we review the literature on the history, ecology, diseases, antimicrobial resistance, and genetics of this bacterium, illustrating the effects of P. distasonis on human and animal health.

Gene Expression of Antioxidant Enzymes in the Resected Intestine in Crohn's Disease

INTRODUCTION

The inflammatory process in Crohn's disease (CD) is closely associated with the formation of reactive oxygen species. Antioxidant enzymes can play an important role in the outcome of CD and may influence postoperative recurrence in these patients. The aim of our study was to evaluate gene expression of intracellular antioxidant enzymes in surgically resected intestinal specimens of patients with CD, both in macroscopically normal and in inflamed tissue.

METHODS

A total of 28 patients referred for elective bowel resection were enrolled in the study. Full-thickness small intestinal specimens were investigated. Gene expression of antioxidant enzymes - superoxide dismutase (SOD), glutathione peroxidase (GPX), glutathione reductase (GSR) - was evaluated both in macroscopically normal and inflamed samples.

RESULTS

There were significantly lower levels of SOD1 mRNA (p = 0.007) and GSR mRNA (p = 0.027) in inflamed tissue compared to macroscopically normal areas. No significant differences were found between affected and non-affected intestinal segments in mRNA for SOD2, SOD3 and GPX.

CONCLUSIONS

Our pilot data clearly showed that the gene expression of major antioxidant enzymes is not a uniform mechanism in the pathogenesis of Crohn's disease. Topically decreased gene expression of SOD1 and GSR might facilitate the segmental tissue injury caused by reactive oxygen species.

Roles of Lipid Peroxidation-Derived Electrophiles in Pathogenesis of Colonic Inflammation and Colon Cancer

Redox stress is a common feature of gut disorders such as colonic inflammation (inflammatory bowel disease or IBD) and colorectal cancer (CRC). This leads to increased colonic formation of lipid-derived electrophiles (LDEs) such as 4-hydroxynonenal (4-HNE), malondialdehyde (MDA), trans, trans-2,4-decadienal (tt-DDE), and epoxyketooctadecenoic acid (EKODE). Recent research by us and others support that treatment with LDEs increases the severity of colitis and exacerbates the development of colon tumorigenesis in vitro and in vivo, supporting a critical role of these compounds in the pathogenesis of IBD and CRC. In this review, we will discuss the effects and mechanisms of LDEs on development of IBD and CRC and lifestyle factors, which could potentially affect tissue levels of LDEs to regulate IBD and CRC development.

Reductively modified albumin attenuates DSS-Induced mouse colitis through rebalancing systemic redox state

Albumin (Alb) is the most abundant plasma protein with multiple biological functions, including antioxidative property through its thiol activity. Given that inflammatory bowel disease is associated with a decreased level of Alb and an increased level of Alb oxidation, we asked whether Alb could have a therapeutic effect on colitis. Here we tested this possibility. Bovine serum albumin (BSA) was reductively modified with dithiothreitol (DTT) and administrated via gavage or intraperitoneal injection. Dextran sulfate sodium (DSS)-induced mice colitis was associated with massive oxidative stress, as indicated by the elevated sulfenic acid formation in blood, colon tissues, and feces. Treatment of mice with the reductively modified albumin (r-Alb) attenuated the oxidative stress and reduced local inflammation and tissue injury. These effects of r-Alb were only partially achieved by unmodified Alb and wholly lost after blocking the -SH groups with maleimide. In cultured colon epithelial cells, r-Alb prevented DSS- and H2O2-induced ROS elevation and barrier dysfunction, preceded by inhibition of sulfenic acid formation and P38 activation. Further analysis revealed that Alb was susceptible to H2O2-induced oxidation, and it detoxified H2O2 in a -SH group-dependent way. Moreover, Alb reacted with GSH/GSSG via thiol-disulfide exchange and reciprocally regulated the availability of -SH groups. Collectively, our study shows that r-Alb effectively attenuates DSS colitis via -SH group-mediated antioxidative action. Given that the oxidative stress underlies many life-threatening diseases, r-Alb, functioning as a potent antioxidant, could have a wide range of applications.

Redox imbalance in Crohn's disease patients is modulated by Azathioprine

Background

Crohn's disease (CD) is a chronic inflammatory disease without a specific cause. Inflammation in these patients can disturb the oxidants/antioxidants balance and results in oxidative stress that plays a destructive role. This study aimed to evaluate the gene expression of sod1, sod2, cat, nrf2 and gp91phox in CD patients before and after Azathioprine (Aza) consumption.

Method

Peripheral bloodmononuclear cells (PBMCs) were separated from CD patients (n= 15, mean age = 33.6 ± 1.8) before and after treatment with Aza and healthy controls (n= 15, mean age = 31.5 ± 1.2). The expression levels of sod1, sod2, cat, nrf2 and gp91phox were measured in byusing real-time qRT-PCR technique.

Result

The expression levels of gp91phox (P-value < 0.001), cat (P-value < 0.05), sod1 (P-value < 0.001), nrf2 (P-value < 0.001) were significantly increased compared to control group. Following treatment with Aza, the decreased expression levels of gp91phox (P-value < 0.05), cat (P-value < 0.05), sod1(P-value < 0.001) and nrf2 (P-value < 0.001) were observed in CD patients.

Conclusion

Overall, our results showed that prescription of Azathioprine can lead to the altered expression of redox system-related genes in patients with CD.

Potassium bromate (KBrO3) modulates oxidative stress and inflammatory biomarkers in sodium hydroxide (NaOH) - induced Crohn's colitis in Wistar rats

Potassium bromate (KBrO₃) present in consumed ozonised water was recently documented to exacerbate experimental gastric ulcer. Information, however, is vague as regards its effects in the colon where water reabsorption occurs. In this study, we observed the possible effects of KBrO₃ on oxidative stress and inflammatory biomarkers in sodium hydroxide (NaOH) - induced Crohn's colitis (CC). Wistar rats (180-200 g) were divided into six groups (n = 10): (i) control; (ii) untreated CC (induced by 1.4% NaOH; intra-rectal administration); and (iii-vi) CC treated with vitamin E, KBrO₃, vitamin E+KBrO₃, and sulphazalazine, respectively, for 7 days. Body weight and stool score were monitored daily. By day 3 and 7, excised colon was evaluated for ulcer scores and biochemical and histological analysis. Blood samples collected on days 3 and 7 were assayed for haematological indices using standard methods. Data were subjected to analysis of variance (ANOVA) and p ≤ 0.05 considered significant. Platelet/lymphocyte ratio, colonic ulcer score, malondialdehyde, and mast cells were significantly decreased while colonic sulfhydryl, and Ca²⁺- and Na⁺/K⁺-ATPase activities were increased following KBrO₃ treatment compared with untreated CC. These findings suggest that KBrO₃ may mitigate against NaOH-induced CC via inhibiting mast cell population and oxidative and inflammatory content but stimulating colonic sulfhydryl and Ca²⁺- and Na⁺/K⁺-ATPase activities.

Oxidative stress in common variable immunodeficiency

Common variable immunodeficiency (CVID) is a heterogenous group of immunologic disorders of unknown etiology. Alterations of the normal cellular balance due to an increase in reactive oxygen species and/or decrease in antioxidant defense may lead to increased oxidative stress. We aimed to evaluate the levels of oxidative stress biomarkers in patients with CVID who had different presentations. We investigated the serum catalase (CAT), erythrocyte superoxide dismutase (SOD), erythrocyte reduced glutathione as antioxidants and serum malondialdehyde levels as lipid peroxidation marker in patients with CVID in Uludag University Hospital Department of Pediatric Allergy and Immunology’s outpatient clinics. In the analysis, there were 21 patients and 27 matched healthy controls. The median levels of CAT in patients with CVID was significantly lower than in healthy controls ( p = 0.04). Among the patients with CVID, 19% had autoimmune disease, one had Sjögren’s syndrome, one had autoimmune alopecia, one had juvenile rheumatoid arthritis, and one had chronic inflammatory demyelinating polyneuropathy. Patients with autoimmune complications had significantly lower CAT levels compared to the ones without autoimmune diseases ( p = 0.03). The patients without non-infectious complications (NICs) had lower SOD levels than the patients with NICs ( p = 0.05). The analysis of oxidative stress markers in the patients with CVID suggested a series of abnormalities in the anti-oxidant system. The clinical syndrome associations may be a useful tool for future studies to set prediction markers for the prognosis of patients with CVID.

The Impact of Oxidative Stress in Human Pathology: Focus on Gastrointestinal Disorders

Accumulating evidence shows that oxidative stress plays an essential role in the pathogenesis and progression of many diseases. The imbalance between the production of reactive oxygen species (ROS) and the antioxidant systems has been extensively studied in pulmonary, neurodegenerative cardiovascular disorders; however, its contribution is still debated in gastrointestinal disorders. Evidence suggests that oxidative stress affects gastrointestinal motility in obesity, and post-infectious disorders by favoring the smooth muscle phenotypic switch toward a synthetic phenotype. The aim of this review is to gain insight into the role played by oxidative stress in gastrointestinal pathologies (GIT), and the involvement of ROS in the signaling underlying the muscular alterations of the gastrointestinal tract (GIT). In addition, potential therapeutic strategies based on the use of antioxidants for the treatment of inflammatory gastrointestinal diseases are reviewed and discussed. Although substantial progress has been made in identifying new techniques capable of assessing the presence of oxidative stress in humans, the biochemical-molecular mechanisms underlying GIT mucosal disorders are not yet well defined. Therefore, further studies are needed to clarify the mechanisms through which oxidative stress-related signaling can contribute to the alteration of the GIT mucosa in order to devise effective preventive and curative therapeutic strategies.

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.

Design of Catalase Monolithic Tablets for Intestinal Targeted Delivery

Several studies confirmed a correlation between elevated hydrogen peroxide (H₂O₂) levels in patients with intestinal bowel diseases (IBD) and the negative effects caused by its presence. The objective of this study was to explore the potential use of catalase (CAT) to diminish the level of H₂O₂ and its deleterious action on intestinal mucosa. Oral dosage forms of a CAT bioactive agent targeted to the intestines were designed and tested in various simulated gastric and intestinal media. Monolithic tablets (30% loading) were prepared using commercial CarboxyMethylCellulose (CMC) or synthesized CarboxyMethylStarch (CMS) and TriMethylAmineCarboxyMethylStarch (TMACMS) as matrix-forming excipients. For starch derivatives, the presence of the ionic groups (carboxymethyl and trimethylamine) was validated by spectral analysis. In vitro studies have shown that tablets formulated with TMACMS and 30% CAT resisted the acidity of the simulated gastric fluid and gradually released the enzyme into the simulated intestinal fluid. The investigation of the CAT release mechanism revealed the role of anionic and cationic groups of polymeric excipients and their involvement in the modulation of the CAT dissolution profile. The proposed drug delivery system can be considered an efficient solution to target CAT release in the intestine and contribute to the reduction of H₂O₂ associated with intestinal inflammation.

Dietary PlsEtn Ameliorates Colon Mucosa Inflammatory Stress and ACF in DMH-Induced Colon Carcinogenesis Mice: Protective Role of Vinyl Ether Linkage

Ethanolamine plasmalogen (PlsEtn), a sub-class of ethanolamine glycerophospholipids (EtnGpl), is a universal phospholipid in mammalian membranes. Several researchers are interested in the relationship between colon carcinogenesis and colon PlsEtn levels. Here, we evaluated the functional role of dietary purified EtnGpl from the ascidian muscle (87.3 mol% PlsEtn in EtnGpl) and porcine liver (7.2 mol% PlsEtn in EtnGpl) in 1,2-dimethylhydrazine (DMH)-induced aberrant crypt foci (ACF) in vivo, and elucidated the possible underlying mechanisms behind it. Dietary EtnGpl-suppressed DMH-induced aberrant crypt with one foci (AC1) and total ACF formation (P < 0.05). ACF suppression by dietary ascidian muscle EtnGpl was higher compared with dietary porcine liver EtnGpl. Additionally, dietary EtnGpl decreased DMH-induced oxidative damage, overproduction of TNF-α, and expression of apoptosis-related proteins in the colon mucosa. The effect of dietary ascidian muscle EtnGpl showed superiority compared with dietary porcine liver EtnGpl. Our results demonstrate the mechanisms by which dietary PlsEtn suppress ACF formation and apoptosis. Dietary PlsEtn attained this suppression by reducing colon inflammation and oxidative stress hence a reduction in DMH-induced intestinal impairment. These findings provide new insights about the functional role of dietary PlsEtn during colon carcinogenesis.

Antioxidant Effects of Turmeric Extract in Rectal Suppositories of Original Composition in Experimental Crohn's Disease

We studied the effect of turmeric extract in the composition of rectal suppositories on the level of LPO products and oxidative modification of proteins in the colon mucosa of Wistar rats with experimental Crohn's disease modeled by rectal administration of trinitrobenzenesulfonic acid. The suppositories containing turmeric extract were administered 12 h after disease induction. On days 3, 5, and 7 of the experiment, clinical parameters of the disease were scored using disease activity scale (DAI) and the concentration of LPO products and intensity of oxidative modification of proteins were measured by the extraction-spectrofluorimetric method. Administration turmeric extract in rectal suppositories reduced the severity of clinical symptoms, the level of LPO products (mostly in the isopropanol phase of the lipid extract), and the total content of products of oxidative modification of proteins. Moreover, correlations between DAI and concentration of LPO products in the colon were found.

Bacterioruberin from Haloarchaea plus dexamethasone in ultra-small macrophage-targeted nanoparticles as potential intestinal repairing agent

Oral administration of antioxidant and anti-inflammatory drugs have the potential to improve the current therapy of inflammatory bowel disease. Success of oral treatments, however, depends on the capacity of drugs to remain structurally stable along the gastrointestinal tract, and on the feasibility of accessing the target cells. Delivering anti-inflammatory and antioxidant drugs to macrophages using targeted nanoparticles, could make treatments more efficient. In this work structural features and in vitro activity of macrophage-targeted nanostructured archaeolipid carriers (NAC) containing the high antioxidant dipolar C50 carotenoid bacterioruberin (BR) plus dexamethasone (Dex): NAC-Dex, are described. Ultra-small (66 nm), -32 mV ζ potential, 1200 μg Dex /ml NAC-Dex, consisted of a compritol and BR core, covered by a shell of sn 2,3 ether linked archaeolipids and Tween 80 (2: 2: 1.2: 3 % w/w) were obtained. NAC-Dex were extensively captured by macrophages and Caco-2 cells and displayed high anti-inflammatory and antioxidant activities on a gut inflammation model made of Caco-2 cells and lipopolysaccharide stimulated THP-1 derived macrophages reducing 65 % and 55 % TNF-α and IL-8 release, respectively and 60 % reactive oxygen species production. NAC-Dex also reversed the morphological changes induced by inflammation and increased the transepithelial electrical resistance, partly reconstituting the barrier function. Activity of BR and Dex in NAC-Dex was partially protected after simulated gastrointestinal digestion, improving the chances of BR-Dex joint activity. Results suggest that oral NAC-Dex deserve further exploration as intestinal barrier repairing agent.

Identification of Epigenetic Methylation Signatures With Clinical Value in Crohn's Disease

INTRODUCTION

DNA methylation is an epigenetic mechanism that regulates gene expression and represents an important link between genotype, environment, and disease. It is a reversible and inheritable mechanism that could offer treatment targets. We aimed to assess the methylation changes on specific genes previously associated with Crohn's disease (CD) and to study their possible associations with the pathology.

METHODS

We included 103 participants and grouped them into 2 cohorts (a first [n = 31] and a second validation [n = 72] cohort), with active CD (aCD) and inactive CD (iCD) and healthy participants (CTR). DNA was obtained from the peripheral blood and analyzed by the Agena platform. The selected genes were catalase (CAT), α-defensin 5 (DEFA5), FasR, FasL, tumor necrosis factor (TNF), TNFRSF1A, TNFRSF1B, PPA2, ABCB1, NOD2, PPARγ, and PKCζ. We used the elastic net algorithm and R software.

RESULTS

We studied 240 CpGs. Sixteen CpGs showed differential methylation profiles among aCD, iCD, and CTR. We selected for validation those with the greatest differences: DEFA5 CpG_11; CpG_13; CAT CpG_31.32; TNF CpG_4, CpG_12; and ABCB1 CpG_21. Our results validated the genes DEFA5 (methylation gain) and TNF (methylation loss) with P values < 0.001. In both cases, the methylation level was maintained and did not change with CD activity (aCD vs iCD). The subanalysis comparison between aCD and iCD showed significant differential methylation profiles in other CpGs: TNF, FAS, ABCB1, CAT, and TNFRS1BF genes.

DISCUSSION

The methylation status of DEFA5 and TNF genes provides a signature biomarker that characterizes patients with CD and supports the possible implication of the environment and the immune system in CD pathogenesis.

Intraperitoneal injection of 4-hydroxynonenal (4-HNE), a lipid peroxidation product, exacerbates colonic inflammation through activation of Toll-like receptor 4 signaling

Human and animal studies have shown that the colonic concentrations of lipid peroxidation products, such as 4-hydroxynonenal (4-HNE), are elevated in inflammatory bowel disease (IBD). However, the actions and mechanisms of these compounds on the development of IBD are unknown. Here, we show that a systemic treatment of low-dose 4-HNE exacerbates dextran sulfate sodium (DSS)-induced IBD in C57BL/6 mice, suggesting its pro-IBD actions in vivo. Treatment with 4-HNE suppressed colonic expressions of tight-junction protein occludin, impaired intestinal barrier function, enhanced translocation of lipopolysaccharide (LPS) and bacterial products from the gut into systemic circulation, leading to increased activation of Toll-like receptor 4 (TLR4) signaling in vivo. Furthermore, 4-HNE failed to promote DSS-induced IBD in Tlr4^-/- mice, supporting that TLR4 signaling contributes to the pro-IBD effects of 4-HNE. Together, these results suggest that 4-HNE exacerbates the progression of IBD through activation of TLR4 signaling, and therefore could contribute to the pathogenesis of IBD.

The Carbamate Aldicarb Altered the Gut Microbiome, Metabolome, and Lipidome of C57BL/6J Mice

The gut microbiome is highly involved in numerous aspects of host physiology, from energy harvest to stress response, and can confer many benefits to the host. The gut microbiome development could be affected by genetic and environmental factors, including pesticides. The carbamate insecticide aldicarb has been extensively used in agriculture, which raises serious public health concerns. However, the impact of aldicarb on the gut microbiome, host metabolome, and lipidome has not been well studied yet. Herein, we use multiomics approaches, including16S rRNA sequencing, shotgun metagenomics sequencing, metabolomics, and lipidomics, to elucidate aldicarb-induced toxicity in the gut microbiome and the host metabolic homeostasis. We demonstrated that aldicarb perturbed the gut microbiome development trajectory, enhanced gut bacterial pathogenicity, altered complex lipid profile, and induced oxidative stress, protein degradation, and DNA damage. The brain metabolism was also disturbed by the aldicarb exposure. These findings may provide a novel understanding of the toxicity of carbamate insecticides.

Antioxidative Efficacy of a Pistacia Lentiscus Supplement and Its Effect on the Plasma Amino Acid Profile in Inflammatory Bowel Disease: A Randomised, Double-Blind, Placebo-Controlled Trial

Oxidative stress is present in patients with Inflammatory Bowel Disease (IBD), and natural supplements with antioxidant properties have been investigated as a non-pharmacological approach. The objective of the present study was to assess the effects of a natural Pistacia lentiscus (PL) supplement on oxidative stress biomarkers and to characterise the plasma-free amino acid (AA) profiles of patients with active IBD (Crohn's disease (CD) N = 40, ulcerative colitis (UC) N = 20). The activity was determined according to 5 ≤ Harvey Bradshaw Index ≤ 16 or 2 ≤ Partial Mayo Score ≤ 6. This is a randomised, double-blind, placebo-controlled clinical trial. IBD patients (N = 60) were randomly allocated to PL (2.8 g/day) or to placebo for 3 months being under no treatment (N = 21) or under stable medical treatment (mesalamine N = 24, azathioprine N = 14, and corticosteroids N = 23) that was either single medication (N = 22) or combined medication (N = 17). Plasma oxidised, low-density lipoprotein (oxLDL), total serum oxidisability, and serum uric acid were evaluated at baseline and follow-up. OxLDL/LDL and oxLDL/High-Density Lipoprotein (HDL) ratios were calculated. The plasma-free AA profile was determined by applying a gas chromatography/mass spectrometry analysis. oxLDL (p = 0.031), oxLDL/HDL (p = 0.020), and oxLDL/LDL (p = 0.005) decreased significantly in the intervention group. The mean change differed significantly in CD between groups for oxLDL/LDL (p = 0.01), and, in the total sample, both oxLDL/LDL (p = 0.015) and oxLDL/HDL (p = 0.044) differed significantly. Several changes were reported in AA levels. PL ameliorated a decrease in plasma-free AAs seen in patients with UC taking placebo. In conclusion, this intervention resulted in favourable changes in oxidative stress biomarkers in active IBD.

Amelioration of Oxidative Stress in Caco-2 Cells Treated with Pro-inflammatory Proteins by Chlorogenic Acid Isomers via Activation of the Nrf2-Keap1-ARE-Signaling Pathway

Understanding the potential effects of chlorogenic acid (CGA) isomers on the intestinal epithelium is important because coffee intake exposes consumers to the six major CGA isomers: 3-caffeoylquinic acid (3-CQA), 4-caffeoylquinic acid (4-CQA), 5-caffeoylquinic acid (5-CQA), 3,4-dicaffeoylquinic acid (3,4-diCQA), 3,5-dicaffeoylquinic acid (3,5-diCQA), and 4,5-dicaffeoylquinic acid (4,5-diCQA). The present study determined the relative effects of CGA isomers on the antioxidant status of inflamed Caco-2 intestinal cells by investigating the oxidative-stress-responsive pathway and nuclear-factor-erythroid-derived-2-like 2 (Nrf2) signaling. Differentiated Caco-2 cells were challenged with the inflammatory mediators PMA and IFNγ, as a model of intestinal inflammation in vitro. Significant redox ( p < 0.05) responses to these mediators were assessed by indirect measurement of induced generation of reactive oxygen species (ROS), as well as the expression of reduced (GSH) and oxidized (GSSG) glutathione. This translated to a 40% reduction in the GSH/GSSG ratio. We found that responses in these parameters were associated with increased Nrf2 activation ( p < 0.05). ROS generation and increased IL-8 secretion were found in challenged cells, indicating an association between induced oxidation and inflammatory status. Oxidative stress was ameliorated by CGA isomers, which scavenged intracellular ROS, increased GSH, and activated Nrf2 signaling. diCQA isomers were relatively more effective at reducing IL-8 ( p < 0.05). The observed increase in Nrf2 signaling led to upregulated expression of some Nrf2 target genes ( GPX2, KEAP1, and NFE2L2) in Caco-2 cells and activated the Nrf2-Keap1-ARE-signaling pathway. These findings indicate that CGA isomers present in coffee have bioactivity toward alleviating oxidative stress associated with intestinal inflammation.

Implications of Antioxidant Systems in Inflammatory Bowel Disease

The global incidence of inflammatory bowel disease (IBD), a group of chronic gastrointestinal disorders, has been rising. The preponderance of evidence demonstrates that oxidative stress (OS) performs a critical function in the onset of IBD and the manner of its development. The purpose of this review is to outline the generation of reactive oxygen species and antioxidant defense mechanisms in the gastrointestinal tract and the role played by OS in marking the onset and development of IBD. Furthermore, the review demonstrates the various ways through which OS is related to genetic susceptibility and the mucosal immune response. The experimental results suggest that certain therapeutic regimens for IBD could have a favorable impact by scavenging free radicals, reducing cytokine and prooxidative enzyme concentrations, and improving the antioxidative capabilities of cells. However, antioxidative activity characterized by a high level of specificity may be fundamental for the development of clinical therapies and for relapsing IBD patients. Therefore, additional research is required to clarify the ways through which OS is related to the pathogenesis and progression of IBD.

Role of NRF2 in protection of the gastrointestinal tract against oxidative stress

The gastrointestinal tract is exposed to a variety of noxious factors, such as Helicobacter pylori, nonsteroidal anti-inflammatory drugs, gastric acid, ischemia-reperfusion, and mental stresses. Theses stressors generate free radicals within gastrointestinal tissues, causing organ injury and functional disturbance. Although the gastrointestinal tract can withstand such oxidative stresses to some extent by enhancing its antioxidant system via nuclear factor erythroid 2-related factor 2-Kelch-like erythroid cell-derived protein with CNC homology-associated protein 1-mediated pathways, acute or chronic exposure to oxidative stress can cause several gastrointestinal tract disorders, such as inflammation, ulcers, cancers, and various functional disturbances. Recent studies have demonstrated that some natural compounds and drugs can upregulate the nuclear factor erythroid 2-related factor 2-mediated antioxidant system, ameliorating or preventing these disorders. Although these compounds may be useful as chemopreventive agents, sufficient evidence for their clinical efficacy has not yet been provided. In addition, it is important to note that excessive nuclear factor erythroid 2-related factor 2 stimulation can be harmful to human health, especially from the standpoint of tumor biology.

Regulation of JAK2/STAT3 and NF-κB signal transduction pathways; Veronica polita alleviates dextran sulfate sodium-induced murine colitis

Ulcerative colitis (UC) is a major inflammatory bowel disease (IBD) has become a worldwide emergent disease. Veronica polita (VP) is a medicinal herb that has strong antioxidant and anti-inflammatory properties. In the present study, we studied the protective effect of VP on dextran sulfate sodium (DSS)-induced experimental colitis in mice. Phytochemical screening of VP extract demonstrated the presence of high total phenolic and flavonoid contents. Compared with the DSS group, VP significantly reduced clinical symptoms with less weight loss, bloody stool, shortening of the colon, and the severity of colitis was considerably inhibited as evidenced by the reduced disease activity index (DAI) and degree of histological damage in the colon and spleen. Also, treatment with VP considerably decreased the nitric oxide (NO) and malondialdehyde (MDA) level. VP remarkably downregulated the expression of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), inducible nitric oxide synthetase (iNOS) and cyclooxygenase-2 (COX-2) in the colon tissue. Likewise, activation of the signal transducer and activator of transcription 3 (STAT3) and nuclear factor-kappa B (NF-κB) was effectively blocked by VP. Taken together, these results demonstrate that VP has an ameliorative effect on colonic inflammation mediated by modulation of oxidative stress and inflammatory mediators by suppressing the JAK2/STAT3 and NF-κB signaling pathways.

Separation of Dual Oxidase 2 and Lactoperoxidase Expression in Intestinal Crypts and Species Differences May Limit Hydrogen Peroxide Scavenging During Mucosal Healing in Mice and Humans

BACKGROUND

DUOX2 and DUOXA2 form the predominant H2O2-producing system in human colorectal mucosa. Inflammation, hypoxia, and 5-aminosalicylic acid increase H2O2 production, supporting innate defense and mucosal healing. Thiocyanate reacts with H2O2 in the presence of lactoperoxidase (LPO) to form hypothiocyanate (OSCN-), which acts as a biocide and H2O2 scavenging system to reduce damage during inflammation. We aimed to discover the organization of Duox2, Duoxa2, and Lpo expression in colonic crypts of Lieberkühn (intestinal glands) of mice and how distributions respond to dextran sodium sulfate (DSS)-induced colitis and subsequent mucosal regeneration.

METHODS

We studied tissue from DSS-exposed mice and human biopsies using in situ hybridization, reverse transcription quantitative polymerase chain reaction, and cDNA microarray analysis.

RESULTS

Duox2 mRNA expression was mostly in the upper crypt quintile while Duoxa2 was more apically focused. Most Lpo mRNA was in the basal quintile, where stem cells reside. Duox2 and Duoxa2 mRNA were increased during the induction and resolution of DSS colitis, while Lpo expression did not increase during the acute phase. Patterns of Lpo expression differed from Duox2 in normal, inflamed, and regenerative mouse crypts (P < 0.001). We found no evidence of LPO expression in the human gut.

CONCLUSIONS

The spatial and temporal separation of H2O2-consuming and -producing enzymes enables a thiocyanate- H2O2 "scavenging" system in murine intestinal crypts to protect the stem/proliferative zones from DNA damage, while still supporting higher H2O2 concentrations apically to aid mucosal healing. The absence of LPO expression in the human gut suggests an alternative mechanism or less protection from DNA damage during H2O2-driven mucosal healing.

Hydrogen peroxide scavenger, catalase, alleviates ion transport dysfunction in murine colitis

Reactive oxygen species (ROS) such as hydrogen peroxide (H₂ O₂ ) contribute to epithelial damage and ion transport dysfunction (key events in inflammatory diarrhoea) in inflammatory bowel disease (IBD). The aim of this study was to identify if H₂ O₂ mediates suppression of colonic ion transport function in the murine dextran sulfate sodium (DSS) colitis model by using the H₂ O₂ degrading enzyme, catalase. Colitis was induced by administering DSS (4%) in drinking water for 5 days followed by 3 days on normal H₂ O. Mice were administered either pegylated catalase or saline at day -1, 0 and +1 of DSS treatment. Ion transport responses to the Ca²⁺ -dependent agonist, carbachol (CCh), or the cAMP-dependent agonist, forskolin, were measured across distal colonic mucosa mounted in Ussing chambers. Parameters of DSS-induced inflammation (loss in body weight, decreased colon length, altered stool consistency), were only partially alleviated by catalase while histology was only minimally improved. However, catalase significantly reversed the DSS-induced reduction in baseline ion transport as well as colonic I_sc responses to CCh. However, ion transport responses to forskolin were not significantly restored. Catalase also reduced activation of ERK MAP kinase in the setting of colitis, and increased expression of the Na⁺ -K⁺ -2Cl^- cotransporter, NKCC1, consistent with restoration of ion transport function. Ex vivo treatment of inflamed colonic mucosae with catalase also partially restored ion transport function. Therefore, catalase partially prevents, and rescues, the loss of ion transport properties in DSS colitis even in the setting of unresolved tissue inflammation. These findings indicate a prominent role for ROS in ion transport dysfunction in colitis and may suggest novel strategies for the treatment of inflammatory diarrhoea.