Advanced oxidation protein products: a novel marker of oxidative stress in ulcerative colitis

Theaflavin Reduces Oxidative Stress and Apoptosis in Oxidized Protein-Induced Granulosa Cells and Improves Production Performance in Laying Hens

This study aims to investigate the effects of theaflavins on production performance and egg quality in laying hens fed oxidized corn gluten meal while evaluating their antioxidant and anti-apoptotic effects on granulosa cells (GCs) from chicken follicles. In total, 600 Lohmann commercial laying hens, aged 64 weeks, were randomly assigned to four treatment groups: a control group, a theaflavin-supplemented group, an oxidized corn gluten meal group, and a combination group. After 8 weeks of feeding, production performance, egg quality, and antioxidant status, along with GC apoptosis and the antioxidant capacity of eggs, were measured. The results demonstrated that oxidized corn gluten meal significantly reduced production performance, antioxidant capacity, and egg quality in laying hens while increasing GC apoptosis. Theaflavin significantly enhanced egg production during weeks 5-8, along with superoxide dismutase activity in the liver, serum, and ovary, alongside egg white reducing power and egg yolk threonine content (p < 0.05). Additionally, theaflavin decreased feed conversion ratios during weeks 5-8 and 1-8, lowered egg white malondialdehyde content (p < 0.05), and inhibited GC apoptosis. In conclusion, oxidized protein reduced production performance, while theaflavin supplementation partially alleviated its adverse effects.

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.

Thiols as a marker of inflammatory bowel disease activity: a systematic review

BACKGROUND

Evidence indicates that inflammation in Inflammatory Bowel Disease (IBD) is associated with increased systemic levels of reactive oxygen species. Systemic oxidative stress has been associated with reduced levels of plasma thiols. Less invasive tests capable of reflecting and predicting IBD activity are increasingly sought after. We sought to systematically review the evidence inherent in serum thiol levels as a marker of Crohn's Disease and Ulcerative Colitis activity (PROSPERO: CRD42021255521).

METHODS

The highest quality documents for systematic reviews standards were used as reference. Articles were searched on Medline via PubMed, VHL, LILACS, WOS, EMBASE, SCOPUS, COCHRANE, CINAHL, OVID, CTGOV, WHO/ICTRP, OPENGREY, BDTD and CAPES, between August, 03 and September, 03 on 2021. Descriptors were defined according to the Medical Subject Heading. Of the 11 articles selected for full reading, 8 were included in the review. It was not possible to perform a pooled analysis of the studies, as there were no combinable studies between subjects with active IBD and controls/inactive disease.

RESULTS

Findings from the individual studies included in this review suggest an association between disease activity and systemic oxidation, as measured by serum thiol levels, however, there are limitations that preclude weighting the study results in a meta-analysis.

CONCLUSIONS

We recommend conducting better-designed and controlled studies, that include individuals of both phenotypes and at different stages of IBD, involving a larger number of participants, using the standardization of the technique for measuring serum thiols, to confirm whether thiols can be a good parameter for monitoring the clinical course of these intestinal diseases and the degree of clinical applicability.

The pharmacological validation of the Xiao-Jian-Zhong formula against ulcerative colitis by network pharmacology integrated with metabolomics

ETHNOPHARMACOLOGICAL RELEVANCE

Inflammatory bowel disease (IBD) is pathologically characterized by an immune response accommodative insufficiency and dysbiosis accompanied by persistent epithelial barrier dysfunction, and is divided into ulcerative colitis (UC) and Crohn's disease (CD). Its progression increases the susceptibility to colitis-associated cancer (CAC), as well as other complications. The Xiao-Jian-Zhong (XJZ) formula has a historical application in the clinic to combat gastrointestinal disorders.

AIM OF THE STUDY

The investigation aimed to explore the molecular and cellular mechanisms of XJZ.

MATERIALS AND METHODS

Dextran sodium sulfate (DSS) was diluted in drinking water and given to mice for a week to establish murine models of experimental colitis, and the XJZ solution was administered for two weeks. Network pharmacology analysis and weighted gene co-expression network analysis (WGCNA) were utilized to predict the therapeutic role of XJZ against UC and CAC. 16S rRNA sequencing and untargeted metabolomics were conducted utilizing murine feces to examine the changes in the microbiome profile. Biochemical experiments were conducted to confirm the predicted functions.

RESULTS

XJZ treatment markedly attenuated DSS-induced experimental colitis progression, and the targets were enriched in inflammation, infection, and tumorigenesis, predicted by network pharmacology analysis. Based on The Cancer Genome Atlas (TCGA) database, the XJZ-targets were related to the survival probability in patients with colorectal cancer, underlying a potential therapeutic value in cancer intervention. Moreover, the XJZ therapy successfully rescued the decreased richness and diversity of microbiota, suppressed the potentially pathogenic phenotype of the gut microorganisms, and reversed the declined linoleic acid metabolism and increased cytochrome P450 activity in murine colitis models. Our in-vitro experiments confirmed that the XJZ treatment suppressed Caspase1-dependent pyroptosis and increased peroxisome proliferators-activated receptor-γ(PPAR-γ) expression in the colon, facilitated the alternative activation of macrophages (Mφs), inhibited tumor necrosis factor-α (TNFα)-induced reactive oxygen species (ROS) level in intestinal organoids (IOs), thereby favoring the mucosal healing.

CONCLUSION

The XJZ formula is efficacious for colitis by a prompt resolution of inflammation and dysbiosis, and by re-establishing a microbiome profile that favors re-epithelization, and prevents carcinogenesis.

Fructus ligustri lucidi suppresses inflammation and restores the microbiome profile in murine colitis models

BACKGROUND

Ulcerative colitis (UC) is pathologically characterized by an inappropriate immune response to the gut commensal microbes accompanied by persistent epithelial barrier dysfunction, and its progression increases the susceptibility to colitis-associated cancer (CAC), as well as other complications. Fructus ligustri lucidi (FLL) has a long historical application in traditional Chinese medicine due to its various pharmacological effects, including antioxidation and anti-inflammation. The present study aimed to explore the molecular and cellular mechanisms of FLL in treating colitis.

METHODS

A high-performance liquid chromatography (HPLC) combined with ultraviolet (UV) was performed to validate the quality of FLL; Network pharmacology analysis and weighted gene co-expression network analysis (WGCNA) based on The Cancer Genome Atlas (TCGA) database predicted the therapeutic value of FLL against UC and CAC; 2% dextran sodium sulfate (DSS) was administered to mice to establish murine models of experimental colitis, and FLL was given for the next 14 days at different concentrations; 16S rRNA sequencing and untargeted metabolomics were performed on fecal samples to delineate the alteration in microbiome profile; Western blotting, flow cytometry, and immunocytochemistry experiments were conducted to confirm the predicted cellular mechanisms.

RESULTS

Network pharmacology analysis and WGCNA predicted that the targets of the FLL were associated with the progression of UC and the survival of patients with colorectal cancer by regulating tumor necrosis factor (TNF) and IL-17 signaling pathways, immune cell functions, responses to bacterial and reactive oxygen species (ROS), and cell proliferation. In vivo experiments corroborated that the high dose of FLL significantly attenuated the progression of experimental colitis by reversing the weight loss and bloody stool, reconstructing the integrity of colorectal epithelium, and suppressing the concentration of pro-inflammatory cytokines. Moreover, FLL treatment reduced the transition of macrophages (Mφs) to the proinflammatory phenotype and promoted Mφs-regulated wound healing, and suppressed the production of ROS in intestinal organoids (IOs) and crypts. 16S rRNA and untargeted metabolomics showed that the administration of FLL inhibited DSS-caused colonization of the potentially pathogenic gut microorganisms and reversed DSS-influenced metabolic profile.

CONCLUSION

FLL is a potent anti-colitis drug by suppressing inflammation and rescuing dysbiosis.

The Cao-Xiang-Wei-Kang formula attenuates the progression of experimental colitis by restoring the homeostasis of the microbiome and suppressing inflammation

Inflammatory bowel disease (IBD) is pathologically characterized by an immune response accommodative insufficiency and dysbiosis accompanied by persistent epithelial barrier dysfunction. The Cao-Xiang-Wei-Kang (CW) formula has been utilized to treat gastrointestinal disorders in the clinic. The present study was designed to delineate the pharmacological mechanisms of this formula from different aspects of the etiology of ulcerative colitis (UC), a major subtype of IBD. Dextran sodium sulfate (DSS) was given to mice for a week at a concentration of 2%, and the CW solution was administered for 3 weeks. 16S rRNA gene sequencing and untargeted metabolomics were conducted to examine the changes in the microbiome profile, and biochemical experiments were performed to confirm the therapeutic functions predicted by system pharmacology analysis. The CW treatment hampered DSS-induced experimental colitis progression, and the targets were enriched in inflammation, infection, and tumorigenesis, which was corroborated by suppressed caspase 3 (Casp3) and interleukin-1b (IL-1b) and increased cleaved caspase 3 expression and casp-3 activity in the colon samples from colitis mice subjected to the CW therapy. Moreover, the CW therapy rescued the decreased richness and diversity, suppressed the potentially pathogenic phenotype of the gut microorganisms, and reversed the altered linoleic acid metabolism and cytochrome P450 activity in murine colitis models. In our in vitro experiments, the CW administration increased the alternative activation of macrophages (Mφs) and inhibited the tumor necrosis factor-α (TNFα)-induced reactive oxygen species (ROS) level and subsequent death in intestinal organoids (IOs). We propose that the CW formula alleviates the progression of murine colitis by suppressing inflammation, promoting mucosal healing, and re-establishing a microbiome profile that favors re-epithelization.

Validation of the Anticolitis Efficacy of the Jian-Wei-Yu-Yang Formula

Background

Inflammatory bowel disease (IBD) is a major cause of morbidity and mortality due to its repetitive remission and relapse. The Jian-Wei-Yu-Yang (JW) formula has a historical application in the clinic to combat gastrointestinal disorders. The investigation aimed to explore the molecular and cellular mechanisms of JW.

Methods

2% dextran sodium sulfate (DSS) was diluted in drinking water and given to mice for 5 days to establish murine models of experimental colitis, and different doses of JW solution were administered for 14 days. Network pharmacology analysis and weighted gene co-expression network analysis (WGCNA) were utilized to predict the therapeutic role of JW against experimental colitis and colitis-associated colorectal cancer (CAC). 16S rRNA sequencing and untargeted metabolomics were conducted using murine feces. Western blotting, immunocytochemistry, and wound healing experiments were performed to confirm the molecular mechanisms.

Results

(1) Liquid chromatography with mass spectrometry was utilized to confirm the validity of the JW formula. The high dose of JW treatment markedly attenuated DSS-induced experimental colitis progression, and the targets were enriched in inflammation, infection, and tumorigenesis. (2) The JW targets were related to the survival probability in patients with colorectal cancer, underlying a potential therapeutic value in CRC intervention. (3) Moreover, the JW therapy successfully rescued the decreased richness and diversity of microbiota, suppressed the potentially pathogenic phenotype of the gut microorganisms, and increased cytochrome P450 activity in murine colitis models. (4) Our in vitro experiments confirmed that the JW treatment suppressed caspase3-dependent pyroptosis, hypoxia-inducible factor 1α (HIF1α), and interleukin-1b (IL-1b) in the colon; facilitated the alternative activation of macrophages (Mφs); and inhibited tumor necrosis factor-α (TNFα)-induced reactive oxygen species (ROS) level in intestinal organoids (IOs).

Conclusion

The JW capsule attenuated the progression of murine colitis by a prompt resolution of inflammation and bloody stool and by re-establishing a microbiome profile that favors re-epithelization and prevents carcinogenesis.

Histone deacetylase inhibitor givinostat has ameliorative effect in the colitis model

Purpose:

To investigate the effect of givinostat treatment in acetic acid-induced ulcerative colitis model in rats.

Methods:

Thirty male Wistar albino rats were used. Rats were randomly divided into three equal groups, and colitis was induced on 20 rats by rectal administration of %4 solutions of acetic acid. Twenty rats with colitis were randomly divided into two groups. %0.9 NaCl (saline) solution was administered intraperitoneally to the first group of rats (saline group, n=10) at the dose of 1 mL/kg/day. Givinostat was administered intraperitoneally to the second group rats (Givinostat group, n=10) at the dose of 5 mg/kg/day. Samples were collected for biochemical analysis. Colon was removed for histopathological and biochemical examinations.

Results:

Plasma tumor necrosis factor-α (TNF-α), pentraxin-3 (PTX-3), and malondialdehyde levels were significantly decreased in the givinostat group compared to the saline group (p<0.05, p<0.001, and p<0.001 respectively; p<0.001, p<0.001, and p<0.001, respectively). Colon TNF-α and prostaglandin F2 alpha (PGF-2) levels were significantly decreased (p<0.05, and p<0.001, respectively). The givinostat group had a significantly lower histologic score than saline group (p<0.001, and p<0.001, respectively).

Conclusions:

Givinostat, a good protector and regenerator of tissue and an anti-inflammatory agent, may be involved in the treatment of colitis in the future.

Tea polyphenols increase the antioxidant status of laying hens fed diets with different levels of ageing corn

This study was conducted to evaluate the effects of ageing corn levels (stored for 4 years) with or without the supplementation of tea polyphenols (TPP) on the performance, egg quality and antioxidant status of laying hens. A total of 288 Lohmann commercial laying hens (63-week-old) were used under a 2 × 4 factorial arrangement with 4 levels of dietary ageing corn (0%, 25%, 50%, or 100%) and 2 levels of TPP (0 and 600 mg/kg) for 8 wk. Dietary ageing corn linearly decreased (P < 0.05) the egg production, serum total antioxidant capacity (T-AOC), liver glutathione peroxidase (GSH-Px) of laying hens, yolk index, yolk colour, 1,1-diphenyl-2-picrylhydrazyl (DPPH) value and the reducing power value of egg yolk, but it linearly increased (P < 0.05) the feed conversion rate, ovary malondialdehyde (MDA) content of laying hens, and the protein carbonyl content of egg yolk. Tea polyphenol supplementation increased (P < 0.05) the serum T-AOC, serum superoxide dismutase (SOD), liver SOD, liver GSH-Px, ovary SOD, GSH-Px, the expression of antioxidant-related genes of laying hens, albumen height, Haugh unit, DPPH value and the majority free amino acids of egg yolk, but it decreased (P < 0.05) the serum MDA content of laying hens, MDA and protein carbonyl of egg yolk. In conclusion, the ageing corn significantly reduced the performance, egg quality, antioxidant status and egg antioxidant capacity of laying hens, while TPP supplementation partially counteracted the adverse effects, especially antioxidant status and egg antioxidant capacity of laying hens.

Advanced Oxidation Protein Product (AOPP) Levels in Second- and Third-Degree Thermal Burns

Burn is a systemic injury affecting the entire organism according to its etiology and severity. The aim of this study was to investigate plasma AOPP levels before and after treatment of second- and third-degree thermal burn patients and determine the changes in this parameter, and also, to find out the relationship between AOPP level and hospitalization period and total body surface area (TBSA). The study material consisted of pediatric patients with the complaint of second- and third-degree thermal burns aged between 1 and 18 years, with a burn area exceeding 10%. Blood samples were taken twice before and after treatment. AOPP level in blood plasma was measured in ELISA. It was observed that in the second-degree thermal burn group, AOPP level was 25.85 ± 2.82 ng/ml before the treatment decreased to 22.16 ± 3.62 ng/ml after treatment, whereas in the third-degree thermal burn group before the treatment AOPP was 25.96 ± 3.49 ng/ml, and after the treatment dropped to 21.70 ± 3.79 ng/ml, decreases were significantly important (P < .05). There was no statistically significant difference between the two groups in terms of AOPP levels (P > .05). Correlation analyses in the second- and third-degree thermal burn group did not show any correlation between AOPP levels and burn area and length of hospitalization period. As a result, AOPP level has been studied, for the first time, in burn cases. In both groups, the level of AOPP increased due to oxidative stress before treatment and decreased after treatment.

Oxidative Stress Markers in Inflammatory Bowel Diseases: Systematic Review

Precise diagnostic biomarker in inflammatory bowel diseases (IBD) is still missing. We conducted a comprehensive overview of oxidative stress markers (OSMs) as potential diagnostic, differential, progression, and prognostic markers in IBD. A Pubmed, Web of Knowledge, and Scopus search of original articles on OSMs in IBD, published between January 2000 and April 2020, was conducted. Out of 874 articles, 79 eligible studies were identified and used to prepare the interpretative synthesis. Antioxidants followed by lipid peroxidation markers were the most popular and markers of oxidative DNA damage the least popular. There was a disparity in the number of retrieved papers evaluating biomarkers in the adult and pediatric population (n = 6). Of the reviewed OSMs, a promising performance has been reported for serum total antioxidant status as a mucosal healing marker, mucosal 8-OHdG as a progression marker, and for multi-analyte panels of lipid peroxidation products assessed non-invasively in breath as diagnostic and differential markers in the pediatric population. Bilirubin, in turn, was the only validated marker. There is a desperate need for non-invasive biomarkers in IBD which, however, will not be met in the near future by oxidative stress markers as they are promising but mostly at the early research phase of discovery.

Oxidized Oils and Oxidized Proteins Induce Apoptosis in Granulosa Cells by Increasing Oxidative Stress in Ovaries of Laying Hens

The storage and preparation of corn for animal feed inevitably lead to lipid and protein peroxidation. Granulosa cells play an important role in follicular development in the ovaries, and hen laying productivity is likely to be dependent on follicle health and number. We hypothesized that oxidized oil and protein induce apoptosis via oxidative stress in laying hen granulosa cells. A sample of 360 38-week-old Lohmann commercial laying hens was used in a 2 × 2 factorial design for 8 weeks. Dietary treatments included dietary oil (fresh corn oil (FO) or oxidized corn oil (OO)) and corn gluten meal (fresh corn gluten meal (FP) or oxidized corn gluten meal (OP)). Productivity, ovarian histology, granulosa cell apoptosis, and indicators of oxidative stress were evaluated in all groups. Both dietary OO and OP decreased egg production and the average daily feed intake (ADFI) of laying hens. Flow cytometry, TUNEL, and real-time PCR revealed that both dietary OO and OP induced granulosa cell apoptosis in prehierarchical and hierarchical follicles. Furthermore, dietary OO and OP caused oxidative stress in prehierarchical and hierarchical follicles, as indicated by the downregulation of antioxidant-related-gene expression. Moreover, forkhead box O1 (FoxO1), extracellular regulated protein kinase (ERK), and c-Jun NH₂ kinase (JNK) are involved in potential apoptosis regulation pathways in the granulosa cells of laying hens fed OO and OP, as indicated by the upregulation of FoxO1 expression and downregulation of ERK/JNK expression. These results indicate that OO and OP induce granulosa cell apoptosis via oxidative stress, and the combined use of OO and OP aggravates the adverse effects of oxidative stress in laying hens.

A study of chewing muscles: Age-related changes in type I collagen and matrix metalloproteinase-2 expression

OBJECTIVE

In this study, the aim was to investigate the biochemical, physiological and histological changes that occur in masticatory muscles of the masticatory system with aging.

DESIGN

In this study, 14 BALB/c mice were used. Animals were divided into two equal groups of seven. Group I was organized as the group of young animals (n = 7) and Group II as the group of adult animals (n = 7). After routine histological follow-up was performed, the tissues were embedded in paraffin. 4-5 μm thick cross-sections were taken from paraffin-embedded tissues and they were stained with Haemotoxylin and Eosin Type I collagen and Matrix metalloproteinase-2 (MMP-2) immunohistochemically.

RESULTS

It was observed that there was a decrease and shrinking in blood vessels due to aging. In young mice, Type I collagen and MMP-2 immunoreactivity in the masseter muscle tissue showed low staining, while Type I collagen and MMP-2 immunoreactivity in the temporal muscle tissue showed moderate staining. Type I collagen and MMP-2 immunoreactivity were significantly higher in the masseter and temporal muscles of elderly mice (p = 0.001). In the H-score evaluation, MMP-2 immune reactivity was significantly lower in young mice than in older mice (p = 0.001).

CONCLUSION

It was determined that severe pain complications and functional losses are likely to occur with the increase of degeneration due to aging of masticator muscles.

Aldehyde Dehydrogenase 2 (ALDH2) in Rat Fatty Liver Cold Ischemia Injury

Institut George Lopez-1 (IGL-1) and Histidine-tryptophan-ketoglutarate (HTK) solutions are proposed as alternatives to UW (gold standard) in liver preservation. Their composition differs in terms of the presence/absence of oncotic agents such as HES or PEG, and is decisive for graft conservation before transplantation. This is especially so when fatty (steatotic) livers are used since these grafts are more vulnerable to ischemia insult during conservation. Their composition determines the extent of the subsequent reperfusion injury after transplantation. Aldehyde dehydrogenase-2 (ALDH2), a mitochondrial enzyme, has been reported to play a protective role in warm ischemia-reperfusion injury (IRI), but its potential in fatty liver cold ischemic injury has not yet been investigated. We evaluated the relevance of ALDH2 activity in cold ischemia injury when fatty liver grafts from Zucker Obese rats were preserved in UW, HTK, and IGL-1 solutions, in order to study the mechanisms involved. ALDH2 upregulation was highest in livers preserved in IGL-1. It was accompanied by a decrease in transaminases, apoptosis (Caspase 3 and TUNEL assay), and lipoperoxidation, which was concomitant with the effective clearance of toxic aldehydes such as 4-hydroxy-nonenal. Variations in ATP levels were also determined. The results were consistent with levels of NF-E2 p45-related factor 2 (Nrf2), an antioxidant factor. Here we report for the first time the relevance of mitochondrial ALDH2 in fatty liver cold preservation and suggest that ALDH2 could be considered a potential therapeutic target or regulator in clinical transplantation.

Advanced Oxidation Protein Products Induce Epithelial-Mesenchymal Transition of Intestinal Epithelial Cells via a PKC δ-Mediated, Redox-Dependent Signaling Pathway

AIMS

Epithelial-mesenchymal transition (EMT) has been considered a fundamental mechanism in complications of Crohn's disease (CD), especially intestinal fibrosis. However, the mechanism underlying EMT regulation in intestinal fibrosis remains unclear. This study aimed to investigate the role of advanced oxidation protein products (AOPPs) in the occurrence of intestinal EMT.

RESULTS

AOPPs accumulated in CD tissues and were associated with EMT marker expression in fibrotic lesions from CD patients. Challenge with AOPPs induced intestinal epithelial cell (IEC) phenotype transdifferentiation, fibroblast-like phenotype acquisition, and production of extracellular matrix, both in vitro and in vivo. The effect of AOPPs was mainly mediated by a protein kinase C (PKC) δ-mediated redox-dependent pathway, including phosphorylation of PKC δ, recruitment of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, production of reactive oxygen species, and NF-κB p65 activation. Inhibition of AOPP-redox signaling activation effectively blocked AOPP-induced EMT in vitro. Studies performed in normal rats showed that chronic administration of AOPPs triggered the occurrence of EMT in rat intestinal epithelia, accompanied by disruption of intestinal integrity, and by promotion of collagen deposition. These effects could be reversed by inhibition of NADPH oxidase. Innovation and Conclusion: This is the first study to demonstrate that AOPPs triggered the occurrence of EMT in IECs in vitro and in vivo through PKC δ-mediated redox-dependent signaling. Our study identifies the role of AOPPs and, in turn, EMT in intestinal fibrosis and provides novel potential targets for the treatment of intestinal fibrotic diseases. Antioxid. Redox Signal. 27, 37-56.

Sex Difference in Oxidative Stress Parameters in Spinal Cord of Rats with Experimental Autoimmune Encephalomyelitis: Relation to Neurological Deficit

The study examined (a) whether there is sex difference in spinal cord and plasma oxidative stress profiles in Dark Agouti rats immunised for experimental autoimmune encephalomyelitis (EAE), the principal experimental model of multiple sclerosis, and (b) whether there is correlation between the oxidative stress in spinal cord and neurological deficit. Regardless of rat sex, with the disease development xanthine oxidase (XO) activity and inducible nitric oxide synthase (iNOS) mRNA expression increased in spinal cord, whereas glutathione levels decreased. This was accompanied by the rise in spinal cord malondialdehyde level. On the other hand, with EAE development superoxide dismutase (SOD) activity decreased, while O₂^- concentration increased only in spinal cord of male rats. Consequently, SOD activity was lower, whereas O₂^- concentration was higher in spinal cord of male rats with clinically manifested EAE. XO activity and iNOS mRNA expression were also elevated in their spinal cord. Consistently, in the effector phase of EAE the concentration of advanced oxidation protein product (AOPP) was higher in spinal cord of male rats, which exhibit more severe neurological deficit than their female counterparts. In as much as data obtained in the experimental models could be translated to humans, the findings may be relevant for designing sex-specific antioxidant therapeutic strategies. Furthermore, the study indicated that the increased pro-oxidant-antioxidant balance in plasma may be an early indicator of EAE development. Moreover, it showed that plasma AOPP level may indicate not only actual activity of the disease, but also serve to predict severity of its course.

Advanced Oxidation Protein Products as a Novel Marker of Oxidative Stress in Postmenopausal Osteoporosis

BACKGROUND

Advanced oxidation protein products (AOPPs) are acknowledged as a novel marker of oxidation-mediated protein damage. This study aimed to investigate the plasma levels of AOPPs in postmenopausal osteoporotic women, and to determine the relationship between AOPPs accumulation and lumbar bone mineral destiny (BMD) or bone turnover markers.

MATERIAL AND METHODS

Lumbar BMD was measured by dual-energy X-ray absorptiometry. Plasma AOPPs levels as a marker of protein oxidation damage and malondialdehyde (MDA) levels as a marker of lipid peroxidation were measured by spectrophotometry. The concentrations of 2 specific markers of bone turnover, bone-specific alkaline phosphatase (BALP) and tartrate-resistant acid phosphatase5b, (TRACP 5b) were quantified using ELISA kits.

RESULTS

We recruited 60 postmenopausal women meeting osteoporosis (OP) diagnostic criteria of World Health Organization (WHO) and 60 postmenopausal women without OP. Plasma levels of AOPPs (P<0.001), BALP (P<0.001) and TRACP 5b (P<0.001) were statistically significantly increased in the postmenopausal osteoporotic women compared with controls, but there was no statistically significant difference in MDA (P=0.124) between the 2 groups. Plasma AOPPs levels were negatively correlated with lumbar BMD and positively correlated with bone turnover markers both in postmenopausal osteoporotic women and in all subjects. However, plasma MDA levels were not correlated with lumbar BMD or bone turnover markers.

CONCLUSIONS

In postmenopausal osteoporotic women elevated AOPPs is associated with reduced BMD and increased bone turnover markers. Because AOPPs is stable and easy to detect it may be used as a simple plasma marker to predict the severity of postmenopausal OP.

Advanced oxidation protein products decrease the expression of calcium transport channels in small intestinal epithelium via the p44/42 MAPK signaling pathway

Advanced oxidation protein products (AOPPs), novel protein markers of oxidative damage, accumulate in the plasma of patients with inflammatory bowel disease (IBD). Osteoporosis, which is closely related to the regulation of intestinal calcium transport channels (CTCs), is a prevalent extraintestinal complication of IBD and is associated with oxidative stress. However, the underlying mechanisms are unknown. The present study aimed to verify whether AOPPs inhibit CTCs in the small intestinal epithelium and to identify the underlying mechanisms that may contribute to IBD-associated osteoporosis. Normal Sprague-Dawley rats were treated with AOPP-modified rat serum albumin. The calcium ion level in serum was not significantly altered, while the duodenal expression of CTCs (e.g. transient receptor potential vanilloid [TRPV6], calbindin-D9k [CaBP-D9k], plasma membrane Ca(2+)-ATPase 1 [PMCA1], and Na(+)/Ca(2+) exchanger 1 [NCX1]) were decreased. In contrast, the levels of the related hormones that regulate calcium absorption including parathyroid hormone (PTH), 25-(OH)D₃, and 1,25-(OH)₂D₃ were increased, although the trend toward an increase in PTH levels was not significant. In order to further investigate the effects of AOPP exposure, we also evaluated the expression of CTCs (including the voltage-dependent L-type calcium channel [CaV1.3], TRPV6, CaBP-D9k, PMCA1, and NCX1) in cultured human colorectal adenocarcinoma cells (Caco-2). The expression levels of total CTC protein and mRNA, except for CaV1.3, were significantly down-regulated in a concentration- and time-dependent manner. Moreover, phosphorylation of p44/42 mitogen-activated protein kinase (MAPK) was observed in vivo and in vitro. The p44/42 inhibitor U0126 reversed the down-regulation of CTCs induced by AOPPs in the Caco-2 monolayer. Our results indicate that AOPPs down-regulate the expression of CTCs through p44/42 MAPK signaling mechanisms in the small intestinal epithelium. These data provide new insights regarding the molecular basis of AOPP-induced reductions in intestinal CTCs, and are relevant to understanding the mechanisms of IBD-associated osteoporosis. Further studies are needed to explore these mechanisms in greater detail.

Curcumin and hesperidin improve cognition by suppressing mitochondrial dysfunction and apoptosis induced by D-galactose in rat brain

D-galactose, a reducing sugar, induces oxidative stress resulting in alteration in mitochondrial dynamics and apoptosis of neurons. Curcumin and hesperidin are antioxidants possessing multimodal functions; hence, their contribution in minimizing D-galactose induced ageing was assessed in the present study. A week prior to D-galactose treatment (150 mg/kg; s.c. for 56 days), animals were treated with curcumin alone, hesperidin alone and a combination of curcumin (50 and 100 mg/kg; orally) with hesperidin (10 and 25 mg/kg; orally) for 63 days. A naïve control was also maintained. Behavioural studies, tricarboxylic acid cycle enzymes, mitochondrial complexes, protein and lipid oxidation and glutathione levels were assessed in the brain mitochondrial fraction. Western blot analysis of caspase-3, cleaved caspase-3 and histological assessment of the CA1 region of the hippocampus were carried out. D-galactose induced significant cognitive deficits, biochemical changes and histological alterations. Individually, curcumin was more effective than hesperidin in reducing the levels of oxidized lipids, proteins, cleaved caspase-3 expression and mitochondrial enzymes. The combination reduced the expression of cleaved caspase-3, malondialdehyde, improved mitochondrial enzymes and glutathione levels. In combination, curcumin and hesperidin protect the morphological facets and improve biochemical functions of neurons thereby improving cognition.

Advanced oxidation protein products induce intestine epithelial cell death through a redox-dependent, c-jun N-terminal kinase and poly (ADP-ribose) polymerase-1-mediated pathway

Advanced oxidation protein products (AOPPs), a novel protein marker of oxidative damage, have been confirmed to accumulate in patients with inflammatory bowel disease (IBD), as well as those with diabetes and chronic kidney disease. However, the role of AOPPs in the intestinal epithelium remains unclear. This study was designed to investigate whether AOPPs have an effect on intestinal epithelial cell (IEC) death and intestinal injury. Immortalized rat intestinal epithelial (IEC-6) cells and normal Sprague Dawley rats were treated with AOPP-albumin prepared by incubation of rat serum albumin (RSA) with hypochlorous acid. Epithelial cell death, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunit activity, reactive oxygen species (ROS) generation, apoptosis-related protein expression, and c-jun N-terminal kinase (JNK) phosphorylation were detected both in vivo and in vitro. In addition, we measured AOPPs deposition and IEC death in 23 subjects with Crohn's disease (CD). Extracellular AOPP-RSA accumulation induced apoptosis in IEC-6 cultures. The triggering effect of AOPPs was mainly mediated by a redox-dependent pathway, including NADPH oxidase-derived ROS generation, JNK phosphorylation, and poly (ADP-ribose) polymerase-1 (PARP-1) activation. Chronic AOPP-RSA administration to normal rats resulted in AOPPs deposition in the villous epithelial cells and in inflammatory cells in the lamina propria. These changes were companied with IEC death, inflammatory cellular infiltration, and intestinal injury. Both cell death and intestinal injury were ameliorated by chronic treatment with apocynin. Furthermore, AOPPs deposition was also observed in IECs and inflammatory cells in the lamina propria of patients with CD. The high immunoreactive score of AOPPs showed increased apoptosis. Our results demonstrate that AOPPs trigger IEC death and intestinal tissue injury via a redox-mediated pathway. These data suggest that AOPPs may represent a novel pathogenic factor that contributes to IBD progression. Targeting AOPP-induced cellular mechanisms might emerge as a promising therapeutic option for patients with IBD.

Curcumin and piperine abrogate lipid and protein oxidation induced by D-galactose in rat brain

Cerebellar atrophy during ageing can produce neurobehavioural changes characterized by cognitive and motor impairment. Chronic exposure to D-galactose, a reducing sugar can accelerate ageing by producing an unprecedented rise in oxidative load. This can enhance neuronal damage by promoting the oxidation of protein and lipids. We perceived that the simultaneous administration of piperine and curcumin, two powerful antioxidants can exert neuroprotective effect by inhibiting damage caused by the chronic exposure to D-galactose. Young Wistar rats treated with D-galactose (150 mg/kg, s.c.) were simultaneously treated with piperine alone, curcumin separately; and in combination for a period of 56 days by the oral route. A vehicle control, D-galactose alone and naturally aged control were also evaluated. Cognitive changes, motor impairment, protein carbonyls, protein thiols, advanced oxidation protein products, 4 hydroxynonenol and nitric oxide levels were determined in the brain homogenate. In order to ascertain the impact of cerebellum on motor performance, histopathological changes in the cerebellum were also established. Results obtained from our studies reflect a marked improvement in memory, sensorimotor performance, reduced oxidative and nitrosative burden on simultaneous treatment with piperine and curcumin. Furthermore, alterations produced in the Purkinje cells were minimized on treatment with the combination. Our studies demonstrated the influence of protein and lipid oxidation products on behavioural changes in D-galactose induced ageing model. Incorporation of these antioxidants might reduce the risk of developing neurodegenerative disorders, an important counterpart of advancing age.

Erythrocyte deformability and oxidative stress in inflammatory bowel disease

BACKGROUND

Oxidative stress and reduced microvascular flow are important factors in the pathogenesis of inflammatory bowel disease (IBD). The increased oxidative stress reduces the erythrocyte deformability. However, in IBD, there are no studies in the literature which evaluate erythrocyte deformability.

AIMS

In our study, we investigated the effect of oxidative stress and erythrocyte deformability in IBD.

METHODS

Forty-three patients with active IBD, 48 patients with inactive IBD and 45 healthy controls were included. The erytrocyte deformability, malonyldialdehyde levels, glutation peroxidase and sulfhydryl levels were measured in peripheral venous blood samples.

RESULTS

Erytrocyte malonyldialdehyde levels in both active and inactive IBD were significantly increased compared with control groups. Plasma glutation peroxidase levels did not show statistically significant difference between all groups. The decreased plasma sulfhydryl levels in active IBD were statistically significant compared with both the inactive IBD and the control group, but plasma sulfhydryl levels in inactive IBD group did not show statistically significant differences when compared with the control group. Elongation index values in both active and inactive IBD increased significantly compared with the control group. Statistically significant correlations were not found between the elongation index and glutation peroxidase, malonyldialdehyde, sulfhydryl levels in all groups.

CONCLUSIONS

Our study is the first to evaluate the erythrocyte deformability in IBD. In our study, increased erytrocyte malonyldialdehyde levels and decreased plasma sulfhydryl levels manifested the role of oxidative stress in the pathogenesis of the disease. It is thought that the increased erythrocyte malonyldialdehyde values cause the reduction in erythrocyte deformability.

Acute reduction of serum 8-iso-PGF2-alpha and advanced oxidation protein products in vivo by a polyphenol-rich beverage; a pilot clinical study with phytochemical and in vitro antioxidant characterization

Background

Measuring the effects of the acute intake of natural products on human biomarker concentrations, such as those related to oxidation and inflammation, can be an advantageous strategy for early clinical research on an ingredient or product.

Methods

31 total healthy subjects were randomized in a double-blinded, placebo-controlled, acute pilot study with post-hoc subgroup analysis on 20 of the subjects. The study examined the effects of a single dose of a polyphenol-rich beverage (PRB), commercially marketed as "SoZo^®", on serum anti-inflammatory and antioxidant markers. In addition, phytochemical analyses of PRB, and in vitro antioxidant capacity were also performed.

Results

At 1 hour post-intake, serum values for 8-iso-PGF2-alpha and advanced oxidation protein products decreased significantly by 40% and 39%, respectively. Additionally, there was a trend toward decreased C-reactive protein, and increased nitric oxide levels. Both placebo and PRB treatment resulted in statistically significant increases in hydroxyl radical antioxidant capacity (HORAC) compared to baseline; PRB showed a higher percent change (55-75% versus 23-74% in placebo group), but the two groups did not differ significantly from each other.

Conclusions

PRB produced statistically significant changes in several blood biomarkers related to antioxidant/anti-inflammatory effects. Future studies are justified to verify results and test for cumulative effects of repeated intakes of PRB. The study demonstrates the potential utility of acute biomarker measurements for evaluating antioxidant/anti-inflammatory effects of natural products.

Effect of blood sample type on the measurement of advanced oxidation protein products as a biomarker of inflammation and oxidative stress in hemodialysis patients

Advanced oxidation protein products (AOPP) is widely used as a uremic biomarker, especially for cardiovascular disease. However, it has not been determined whether it is better to measure AOPP in plasma or serum. In this cross-sectional study, which included 102 patients undergoing maintenance hemodialysis, fibrinogen-free serum and defibrinated plasma samples were prepared. AOPP levels from fibrinogen-free samples displayed a stronger correlation with myeloperoxidase activity and levels of C-reactive protein, interleukin-6 and tumor necrosis factor-alpha, as well as prevalent cardiovascular disease, than AOPP levels obtained from plasma samples. These results demonstrated that fibrinogen interferes with the measurement of AOPP.