Advanced Oxidation Protein Products Concentrations Research Articles

Advanced Oxidation Protein Products and Carbonylated Proteins as Biomarkers of Oxidative Stress in Selected Atherosclerosis-Mediated Diseases.

Objectives The main question of this study was to evaluate the intensity of oxidative protein modification shown as advanced oxidation protein products (AOPP) and carbonylated proteins, expressed as protein carbonyl content (C=O) in abdominal aortic aneurysms (AAA), aortoiliac occlusive disease (AIOD), and chronic kidney disease (CKD). Design and Methods The study was carried out in a group of 35 AAA patients and 13 AIOD patients. However, CKD patients were divided into two groups: predialysis (PRE) included 50 patients or hemodialysis (HD) consisted of 34 patients. AOPP and C=O were measured using colorimetric assay kit, while C-reactive protein concentration was measured by high-sensitivity assay (hsCRP). Results The concentration of AOPP in both AAA and AIOD groups was higher than in PRE and HD groups according to descending order: AAA~AIOD > HD > PRE. The content of C=O was higher in the PRE group in comparison to AIOD and AAA according to the descending order: PRE~HD > AAA~AIOD. Conclusions AAA, AIOD, and CKD-related atherosclerosis (PRE and HD) contribute to the changes in the formation of AOPP and C=O. They may promote modification of proteins in a different way, probably due to the various factors that influence oxidative stress here.

Oxidative stress and polycystic ovary syndrome: evaluation during ovarian stimulation for ICSI.

Oxidative stress (OS) may affect natural fertility and the results of assisted reproduction techniques (ARTs). Subfertility associated with polycystic ovary syndrome (PCOS) may be related to OS. This process may intensify during controlled ovarian stimulation (COS) for ARTs because of increased ovarian metabolic activity and hypoestrogenism with the use of gonadotropin-releasing hormone agonists (GnRHas). The objective of this study was to investigate the presence of systemic OS in non-stimulated cycles and to determine OS markers (malondialdehyde [MDA], advanced oxidation protein products [AOPP], hydroperoxides [FOX], glutathione [GSH], and vitamin E) during COS in non-obese infertile women with and without PCOS who were subjected to ARTs. A prospective cohort study was conducted on non-obese women (16 with PCOS, and 60 ovulatory patients with infertility due to male and/or tubal factors). The OS markers were determined during the following time-points: the follicular phase of the natural cycle (D1), after pituitary downregulation with GnRHa and before the use of gonadotropins (D2), on the day of administration of human chorionic gonadotropin (D3), and at oocyte retrieval (D4). Intergroup analysis showed that serum MDA concentrations were higher in the PCOS group at D3 (P=0.048) and D4 (P=0.002). On an intragroup analysis, the control group had higher MDA concentrations at D2 than at D1 (P=0.01) or D4 (P=0.004). The AOPP concentrations were higher at D2 (P<0.0001), D3 (P<0.001) and D4 (P<0.0001) compared to D1. The FOX concentrations were lower at D2 (P<0.0001), D3 (P<0.0001), and D4 (P<0.001) than at D1. Serum GSH concentrations were significantly higher at D4 than at D1 (P=0.02). An intragroup analysis of the PCOS subjects showed that the five OS markers did not differ significantly among the four time-points when they were analyzed (D1, D2, D3 and D4). In conclusion, non-obese infertile women with PCOS showed evidence of systemic OS after COS with gonadotropins for ICSI. On the other hand, non-obese ovulatory infertile women, and women with infertility due to male and/or tubal factors showed a possible systemic oxidative balance until the final of COS.

Impact of Dietary Composition and Exercise on Functional Capacity and Cardio-metabolic Health in Male Rats

A purified vegan diet known as “Daniel Fast” (DF) has attracted great attention due to its health-enhancing properties. However, the effects of this vegan diet combined with exercise training on physical performance and cardio-metabolic health remains to be established. PURPOSE: To determine the effects of a 12-week DF with or without endurance exercise training on body composition, physical performance, cardio-metabolic profile, and oxidative stress in male rats. METHODS: Long-Evans male rats (N=28) were assigned to be exercise trained (+E) by running on a treadmill (3d/week) or to act as sedentary controls. After baseline functional capacity was evaluated by recording run time to exhaustion, animals were randomly allocated to the vegan DF or a Western Diet (WD) group. Food was provided ad libitum for 12 weeks. Once post-intervention physical performance and body composition assessments [dual X-ray absorptiometry (DXA)] were completed, blood was collected for evaluation of cardio-metabolic profile parameters (glucose, triglyceride, and cholesterol) and a selected biomarker of oxidative stress [advanced oxidation protein products (AOPP)]. Analysis of variance (AVOVA) was used with significance set at p≤0.05. RESULTS: Body mass and body fat were lower in the DF+E group compared to the WD+E group (body mass: 478.7±11.3 g vs. 516.8±10.7 g) (fat mass: 100.7±7.4 g vs. 161.6±8.0 g). Physical performance was higher compared to baseline for both exercise groups, with a greater percent increase in the DF+E group (+81%) compared to the WD+E group (+36%). Concentration of blood glucose, triglyceride, and cholesterol was lower in the DF (129±9; 74±13.1; 74.6±4.3 mg·dL-1) and DF+E (113±3; 65.5±7.5; 67.2±5.2 mg·dL-1) groups than the WD (182±7; 477±67.9; 191±21.2 mg·dL-1) and WD+E groups (158±10; 408±57.7; 135.8±9.9 mg·dL-1), respectively. Further, the AOPP concentration was lower in the DF (67±15 μmol·L-1) and DF+E (50±7 μmol·L-1) groups than in the WD (573±53 μmol·L-1) and WD+E (413±56 μmol·L-1) groups, respectively. CONCLUSION: The DF with ad libitum feeding resulted in lower body mass and body fat accumulation, enhanced physical performance, and improved cardio-metabolic parameters with lower oxidative stress regardless of amount of calories consumed.

Inhibition of glycoxidative modification of proteins by some substances of natural origin

Summary Introduction: Advanced glycation end-products (AGE) and advanced oxidation protein products (AOPP) are the main products of glycoxidative modification in diabetes. Objective: The aim of this study was to identify the natural substance with the strongest antiglycoxidative properties among dietary supplements or medicines available without prescription in Poland. Methods: Bovine serum albumin (BSA), vitamin C (VC), aminoguanidine (A), quercetin (Q) and green tea (GT) were tested in vitro in comparison to controls in glycation, oxidation and glycoxidation processes. The decreased AGE and AOPP concentrations were measured as markers of these processes. Results: AGE level was reduced by 72% by VC and at least by 43% by all examined substances in the glycation process. AOPP was reduced by 99% by VC and at least by 40% by all examined substances in the oxidation process. Formation of AGE/AOPP was inhibited by 61% by Q and by 97% by A, and at least 49/88% by all examined substances, respectively. This lowering of AGE/AOPP level was statistically significant (p&lt;0.001) for all test substances in comparison to the positive control C(+). Conclusion: All examined substances are able to inhibit glycative, oxidative and glycoxidative modification of proteins in different degrees depending on their concentration.

Glutathione peroxidase-1 gene (GPX1) variants, oxidative stress and risk of kidney complications in people with type 1 diabetes

Background and AimGlutathione peroxidase (GPX) is a class of antioxidant enzymes that catalyze the reduction of hydrogen peroxide to water. GPX1 is the most abundant isoform and is expressed in all kidney cells. Isoprostane and advanced oxidation protein products (AOPP) were identified as markers of oxidative stress in patients with kidney disease. We investigated associations of GPX1 genotypes with kidney complications, and with plasma concentrations of isoprostane and AOPP in type 1 diabetic patients. MethodsFour SNPs in the GPX1 gene region were genotyped in SURGENE (n=340; 10-year follow-up); GENEDIAB (n=461) and GENESIS (n=584) cohorts of type 1 diabetic patients. Subsets of GENEDIAB (n=237) and GENESIS (n=466) participants were followed up for 9 and 5years, respectively. Plasma concentrations of isoprostane and AOPP were measured at baseline in GENEDIAB. Hazard ratios (HR) were estimated for incidence of kidney complications. ResultsIn SURGENE, 98 renal events (new cases of microalbuminuria or progression to more severe stage of diabetic nephropathy) occurred during follow-up. The minor T-allele of rs3448 was associated with the incidence of renal events (HR 1.81, 95% CI 1.16–2.84, p=0.008). In GENESIS/GENEDIAB pooled study, end stage renal disease (ESRD) occurred during follow-up in 52 individuals. The same variant was associated with the incidence of ESRD (HR 3.34, 95% CI, 1.69–6.98, p=0.0004). The variant was also associated with higher plasma isoprostane concentration in GENEDIAB cohort: 2.02±0.12 (TT+CT) vs 1.75±0.13 (CC) ng/mL (p=0.009), and with higher plasma AOPP in the subset of participants with the baseline history of ESRD (TT+CT 67±6 vs CC 48±6μmol/L, p=0.006). ConclusionsThe minor T-allele of rs3448 was associated with kidney complications (incidences of microalbuminuria, renal events and ESRD) in patients with type 1 diabetes. The risk allele was associated with higher plasma concentrations of isoprostane and AOPP. Our results are consistent with the implication of GPX1 in the mechanism of renal protection against oxidative stress in type 1 diabetic patients.

Prooxidant/Antioxidant Balance in Hypoxia: A Cross-Over Study on Normobaric vs. Hypobaric "Live High-Train Low".

“Live High-Train Low” (LHTL) training can alter oxidative status of athletes. This study compared prooxidant/antioxidant balance responses following two LHTL protocols of the same duration and at the same living altitude of 2250 m in either normobaric (NH) or hypobaric (HH) hypoxia. Twenty-four well-trained triathletes underwent the following two 18-day LHTL protocols in a cross-over and randomized manner: Living altitude (PIO2 = 111.9 ± 0.6 vs. 111.6 ± 0.6 mmHg in NH and HH, respectively); training “natural” altitude (~1000–1100 m) and training loads were precisely matched between both LHTL protocols. Plasma levels of oxidative stress [advanced oxidation protein products (AOPP) and nitrotyrosine] and antioxidant markers [ferric-reducing antioxidant power (FRAP), superoxide dismutase (SOD) and catalase], NO metabolism end-products (NOx) and uric acid (UA) were determined before (Pre) and after (Post) the LHTL. Cumulative hypoxic exposure was lower during the NH (229 ± 6 hrs.) compared to the HH (310 ± 4 hrs.; P<0.01) protocol. Following the LHTL, the concentration of AOPP decreased (-27%; P<0.01) and nitrotyrosine increased (+67%; P<0.05) in HH only. FRAP was decreased (-27%; P<0.05) after the NH while was SOD and UA were only increased following the HH (SOD: +54%; P<0.01 and UA: +15%; P<0.01). Catalase activity was increased in the NH only (+20%; P<0.05). These data suggest that 18-days of LHTL performed in either NH or HH differentially affect oxidative status of athletes. Higher oxidative stress levels following the HH LHTL might be explained by the higher overall hypoxic dose and different physiological responses between the NH and HH.

Treatment With Cinacalcet Increases Plasma Adiponectin Concentration in Hemodialyzed Patients With Chronic Kidney Disease and Secondary Hyperparathyroidism

Cinacalcet increases calcium-sensing receptor (CaSR) sensitivity to serum calcium. CaSR is expressed by adipocytes, and adiponectin is an adipokine with antiatherogenic and insulin-sensitizing properties. The aim of this study was to assess the influence of a 3-month cinacalcet regimen on plasma adiponectin concentration in hemodialyzed patients (HDP) with chronic kidney disease (CKD) and secondary hyperparathyroidism (sHPT). Plasma adiponectin, advanced oxidation protein products (AOPP), serum interleukin-6 (IL-6) and C-reactive protein (CRP) concentrations were assessed in 65 HDP with sHPT treated with cinacalcet (30-120 mg/day) before the first dose and after 3 months of treatment. There was a significant decrease in serum parathyroid hormone (PTH) concentration: from 1,089 (891-1,286) pg/mL to 775 (574-976) pg/mL after 3 months of treatment (P<.0001). The treatment was associated with a significant (P = .048) increase in plasma adiponectin concentration from 16.9 (14.4-19.5) μg/mL to 17.8 (15.0-20.6) μg/mL. Significant (P = .03) reduction of plasma AOPP concentration was observed from 186.7 (156.7-216.7) pg/mL to 162.6 (141.2-183.9) pg/mL. A 3-month cinacalcet regimen increased plasma adiponectin concentrations in HDP with sHPT. Increased adiponectinemia in these patients may be related to reduced oxidative stress.

Oxidant and antioxidant status in experimental rat testis after testicular torsion/detorsion.

The aim of this study was to determine oxidative stress (OS) parameters after testicular torsion/detorsion in adult rats. In this experimental study, male adult Wistar rats were divided into four groups, each consisting of seven animals: group I-one hour right testicular torsion with subsequent orchiectomy, group II-one hour right testicular torsion followed by detorsion, group III-unilateral right-sided orchiectomy without previous torsion and group IV-control. After 30 days, bilateral orchiectomies were performed in rats with both testes and unilateral orchiectomies in rats with single testicles. Parameters of OS were determined in testicular tissue and in plasma. Plasma concentrations of advanced oxidation protein products (AOPP) and thiobarbituric acid reactive substances (TBARS) were higher (p<0.05 and p<0.01, respectively), whilst the plasma concentration of the total sulfhydryl (T-SH)-groups was lower (p<0.05) in group I compared to the control group. Group II had higher plasma concentrations of AOPP compared to group IV (p<0.05), as well as significantly increased TBARS and decreased T-SH-group levels compared to groups III (p<0.05 and p<0.01, respectively) and IV (p<0.01, for both parameters). There were significant differences in OS markers between the ipsilateral and contralateral testis, as well as significant correlations among levels of both plasma and tissue markers of OS. The increase in TBARS levels seen throughout the experimental period indicated that OS development was caused by ischemia/reperfusion in the testicular tissue. The oxidant-antioxidant system of the testicular tissue was altered during torsion as well as detorsion.

Allelic variations in the CYBA gene of NADPH oxidase and risk of kidney complications in patients with type 1 diabetes

Oxidative stress plays a pivotal role in the pathophysiology of diabetic nephropathy, and the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase system is an important source of reactive oxygen species in hyperglycemic conditions in the kidney. Plasma concentration of advanced oxidation protein products (AOPP), a marker of oxidative stress, is increased in patients with diabetic nephropathy. We investigated associations of variants in the CYBA gene, encoding the regulatory subunit p22phox of NADPH oxidase, with diabetic nephropathy and plasma AOPP and myeloperoxidase (MPO) concentrations in type 1 diabetic patients. Seven SNPs in the CYBA region were analyzed in 1357 Caucasian subjects with type 1 diabetes from the SURGENE (n=340), GENEDIAB (n=444), and GENESIS (n=573) cohorts. Duration of follow-up was 10, 9, and 6 years, respectively. Cox proportional hazards and logistic regression analyses were used to estimate hazard ratios (HR) or odds ratios (OR) for incidence and prevalence of diabetic nephropathy. The major G-allele of rs9932581 was associated with the incidence of renal events defined as new cases of microalbuminuria or the progression to a more severe stage of nephropathy during follow-up (HR 1.59, 95% CI 1.17–2.18, P=0.003) in SURGENE. The same allele was associated with established/advanced nephropathy (OR 1.52, 95% CI 1.22–1.92, P=0.0001) and with the incidence of end-stage renal disease (ESRD) (HR 2.01, 95% CI 1.30–3.24, P=0.001) in GENEDIAB/GENESIS pooled studies. The risk allele was also associated with higher plasma AOPP concentration in subsets of SURGENE and GENEDIAB, with higher plasma MPO concentration in a subset of GENEDIAB, and with lower estimated glomerular filtration rate (eGFR) in the three cohorts. In conclusion, a functional variant in the promoter of the CYBA gene was associated with lower eGFR and with prevalence and incidence of diabetic nephropathy and ESRD in type 1 diabetic patients. These results are consistent with a role for NADPH oxidase in the pathophysiology of kidney complications of diabetes.

Oxidative stress markers are increased in patients with mastocytosis.

Mastocytosis is characterized by clonal proliferation of mast cells limited to the skin (cutaneous mastocytosis: CM and mastocytosis in the skin: MIS) and/or involving internal organs (systemic mastocytosis: SM). Oxidative stress occurring in various inflammatory and neoplastic disorders causes molecular damage with the production of advanced oxidation protein products (AOPPs) and advanced glycation end products (AGEs). We evaluated these markers of oxidative stress in patients with CM/MIS and SM and correlated their levels with the presence of symptoms related to mast cell activation. Serum levels of AOPPs and AGEs in 34 patients with mastocytosis (23 CM/MIS and 11 SM) and 27 healthy controls were measured by spectrofluorimetric and spectrophotometric methods. Serum tryptase levels were measured by immunofluorescence. Serum AOPPs, but not AGEs, were significantly higher in patients with mastocytosis as compared to healthy controls. While serum tryptase levels were higher in patients with SM as compared to those with CM/MIS, there was no difference in AOPP and AGE concentrations between these two groups of patients. Patients with recurrent mediator-related symptoms had lower AOPPs and AGEs as compared to patients without symptoms. AOPPs and AGEs were inversely correlated with the severity of symptoms, and in patients with symptoms, AOPPs correlated with tryptase levels. Our data show that mastocytosis is associated with a state of increased oxidative stress that, in patients with mediator-related symptoms, correlates with mast cell burden as assessed by tryptase. Patients with symptoms presumably have an adaptive response resulting in lower blood levels of AOPPs and AGEs.

Plasma extracellular superoxide dismutase concentration, allelic variations in the SOD3 gene and risk of myocardial infarction and all-cause mortality in people with type 1 and type 2 diabetes.

BackgroundOxidative stress is involved in development of diabetes complications. Extracellular superoxide dismutase (EC-SOD, SOD3) is a major extracellular antioxidant enzyme and is highly expressed in arterial walls. Advanced oxidation protein products (AOPP) and 8-iso-prostaglandin (isoprostane) are markers of oxidative stress. We investigated association of SOD3 gene variants, plasma concentrations of EC-SOD, AOPP and isoprostane with myocardial infarction and mortality in diabetic patients.MethodsWe studied three cohorts designed to evaluate the vascular complications of diabetes: the GENEDIAB study (469 participants with type 1 diabetes at baseline; follow-up data for 259 participants), the GENESIS study (603 participants with type 1 diabetes at baseline; follow-up data for 525 participants) and the DIABHYCAR study (3137 participants with type 2 diabetes at baseline and follow-up). Duration of follow-up was 9, 5, and 5 years, respectively. Main outcome measures were incidence of myocardial infarction, and cardiovascular and total mortality during follow-up. Six single nucleotide polymorphisms in the SOD3 locus were genotyped in the three cohorts. Plasma concentrations of EC-SOD, AOPP, and isoprostane were measured in baseline samples of GENEDIAB participants.ResultsIn GENEDIAB/GENESIS pooled cohorts, the minor T-allele of rs2284659 variant was inversely associated with the prevalence at baseline (Odds Ratio 0.48, 95% CI 0.29–0.78, p = 0.004) and the incidence during follow-up of myocardial infarction (Hazard Ratio 0.58, 95% CI 0.40–0.83, p = 0.003) and with cardiovascular (HR 0.33, 95% CI 0.08–0.74, p = 0.004) and all-cause mortality (HR 0.44, 95% CI 0.21–0.73, p = 0.0006). The protective allele was associated with higher plasma EC-SOD and lower plasma AOPP concentrations in GENEDIAB. It was also inversely associated with incidence of myocardial infarction (HR 0.75, 95% CI 0.59–0.94, p = 0.01) and all-cause mortality (HR 0.87, 95% CI 0.79–0.97, p = 0.008) in DIABHYCAR.ConclusionsThe T-allele of rs2284659 in the promoter of SOD3 was associated with a more favorable plasma redox status and with better cardiovascular outcomes in diabetic patients. Our results suggest that EC-SOD plays an important role in the mechanisms of vascular protection against diabetes-related oxidative stress.Electronic supplementary materialThe online version of this article (doi:10.1186/s12933-014-0163-2) contains supplementary material, which is available to authorized users.

Optimisation of an Advanced Oxidation Protein Products Assay: Its Application to Studies of Oxidative Stress in Diabetes Mellitus.

Advanced oxidation protein products (AOPP) are reportedly elevated in the plasma of patients with a number of diseases, including diabetes mellitus, that involve oxidative stress. However, the accurate measurement of AOPP in human plasma is hampered by the formation of a precipitate following the addition of potassium iodide and glacial acetic acid according to the published assay procedure. Here we describe a modification of the AOPP assay which eliminates interference by precipitation and provides a robust, reliable, and reproducible protocol for the measurement of iodide oxidising capacity in plasma samples (intra-assay CV 1.7–5.3%, interassay CV 5.3–10.5%). The improved method revealed a significant association of AOPP levels with age (p < 0.05) and hypertension (p = 0.01) in EDTA-anticoagulated plasma samples from 52 patients with diabetes and 38 nondiabetic control subjects, suggesting a possible link between plasma oxidising capacity and endothelial and/or vascular dysfunction. There was no significant difference between AOPP concentrations in diabetic (74.8 ± 7.2 μM chloramine T equivalents) and nondiabetic (75.5 ± 7.0 μM chloramine T equivalents) individuals.

Perspectives on the pharmacotherapy of diseases extending with advanced oxidation protein products participation

In the view of constantly increasing number of reports about participation of advanced oxidation protein products (AOPPs) in pathogenesis of many diseases as well as in the pathomechanism of their biochemical disturbances and clinical complications, the possibility of treatment of these diseases by reducing of AOPPs concentration and prevention or inhibition of their formation poses the object of intensive investigations. The first investigated agents, with proven efficacy in prevention of AOPPs formation, was N-acetylcysteine. In relationship with the fact, that the intensified formation of AOPPs is closely connected with intensity of oxidative stress (OS), so the possibility of use of agents and/or drugs with well-known antioxidative proprieties, also natural origin, was examined. It is very important in aspects of its self-treatment by patients. The next step was the estimation of possibility of utilization of pleiotropic properties of drugs routinely applied in the treatment of civilization diseases, especially hypertension and diabetes, often with kidneys insufficiency. On the basis of known mechanism of the unfavorable acting of AOPPs (induction of intracellular signal transduction, and secondary intensyfication of OS), on the way of its connection with the RAGE receptor [similarly as advanced glycation end products (AGEs)], indicated on the possibility of new therapeutic strategies, through the blocking of RAGE-AGEs interactions or using the soluble form of this receptor. Discussed in this paper results of investigations shows the possibility to introduction in the near future, the innovative therapeutic strategies, directed just on the AOPPs, permitting on the limitation of their formation and accumulation in tissues and organs, especially in kidneys. This will permit for the break of mechanism of vicious circle of interaction OS and oxidatively modified macromolecules and attenuating of biochemical and clinical disturbances in the diseases connected with AOPPs participating.

Protein oxidative stress markers in peritoneal fluids of women with deep infiltrating endometriosis are increased.

Are protein oxidative stress markers [thiols, advanced oxidation protein products (AOPP), protein carbonyls and nitrates/nitrites] in perioperative peritoneal fluid higher in women with histologically proven endometriosis when compared with endometriosis-free controls? Protein oxidative stress markers are significantly increased in peritoneal fluids from women with deep infiltrating endometriosis with intestinal involvement when compared with endometriosis-free controls. Endometriosis is a common gynaecologic condition characterized by an important inflammatory process. Various source of evidence support the role of oxidative stress in the development of endometriosis. We conducted a prospective laboratory study in a tertiary-care university hospital between January 2011 and December 2012, and included 235 non-pregnant women, younger than 42 year old, undergoing surgery for a benign gynaecological condition. After complete surgical exploration of the abdomino-pelvic cavity, 150 women with histologically proven endometriosis and 85 endometriosis-free controls women were enrolled. Women with endometriosis were staged according to a surgical classification in three different phenotypes of endometriosis: superficial peritoneal endometriosis (SUP), ovarian endometrioma (OMA) and deeply infiltrating endometriosis (DIE). Perioperative peritoneal fluids samples were obtained from all study participants. Thiols, AOPP, protein carbonyls and nitrates/nitrites were assayed in all peritoneal samples. Concentrations of peritoneal AOPP were significantly higher in endometriosis patients than in the control group (median, 128.9 µmol/l; range, 0.3-1180.1 versus median, 77.8 µmol/l; range, 0.8-616.1; P < 0.001). In a similar manner concentrations of peritoneal nitrates/nitrites were higher in endometriosis patients than in the control group (median, 24.8 µmol/l; range, 1.6-681.6 versus median, 18.5 µmol/l; range, 1.6-184.5; P < 0.05). According to the surgical classification, peritoneal fluids protein AOPP and nitrates/nitrites were significantly increased only in DIE samples when compared with controls (P < 0.001 and P < 0.05; respectively), whereas the others forms of endometriosis (SUP and OMA) showed non-statistically significant increases. We found positive correlations between peritoneal fluids AOPP concentrations, nitrites/nitrates levels and the total number of intestinal DIE lesions (r = 0.464; P < 0.001 and r = 0.366; P = 0.007; respectively). Inclusion of only surgical patients may constitute a possible selection bias. In fact, our control group involved women who underwent surgery for benign gynaecological conditions. This specificity of our control group may lead to biases stemming from the fact that some of these conditions, such as fibroids, ovarian cysts or tubal infertility, might be associated with altered peritoneal proteins oxidative stress markers. We demonstrate the existence of a significantly increased protein oxidative stress status in peritoneal fluid from women with endometriosis especially in cases of DIE with intestinal involvement. This study opens the way to future more mechanistics studies to determine the exact role of protein oxidative stress in the pathogenesis of endometriosis. Even if an association does not establish proof of cause and effect, these intrinsic biochemical characteristics of endometriosis may lead to the evaluation of therapeutic approaches targeting oxidative imbalance. No funding was used for this study. The authors have no conflict of interest.

Assessment of oxidative stress biomarkers in exhaled breath condensate and blood of dairy heifer calves from birth to weaning

The balance between oxidants and antioxidants may be impaired in neonatal calves but only limited information is available on physiological changes in oxidative biomarkers in healthy calves. The aim of this study was to measure biomarkers of oxidative stress (OS) in calves from birth to weaning. Eighteen, healthy, female Holstein-Friesian calves were used in the study. Blood and exhaled breath condensate (EBC) samples were taken on the day of birth (Week 0) and then at Weeks 6, 12 and 18. Reactive oxygen metabolites (ROMs) and biological antioxidant potential (BAP) were determined on fresh blood and the degree of OS was expressed as an oxidative stress index (OSI), where OSI = ROMs/BAP × 100. Plasma concentrations of antioxidant barrier (OXY), thiol antioxidant barrier (SH), advanced oxidation protein products (AOPP), albumin, and non-esterified fatty acids (NEFA) were also measured, as was hydrogen peroxide (H2O2) concentration in EBC.Plasma concentrations of ROMs were relatively stable during the trial; AOPP concentration progressively decreased reaching its lowest values on Week 18. Albumin, SH and OXY concentrations progressively increased from birth to weaning. Concentrations of NEFA in plasma and H2O2 in EBC were relatively stable but peaked in Week 18. The results indicate that antioxidative defence not only increases with time in the plasma of new-born calves but also that it is related to protein oxidation processes. Furthermore, the data support the use EBC H2O2 as a novel biomarker to assess respiratory OS in calves.

The Tibetan herbal medicines Padma 28 and Padma Circosan inhibit the formation of advanced glycation endproducts (AGE) and advanced oxidation protein products (AOPP) in vitro.

BackgroundAdvanced glycation endproducts (AGE) and advanced oxidation protein products (AOPP) play a pivotal role in the development of diabetes associated diseases. The herbal medicines Padma 28 and Padma Circosan have shown effectiveness in symptoms of diabetes associated diseases and have antioxidant effects. It is not known whether inhibition of AGE and AOPP formation is a mechanism of their action.MethodBSA was subjected to glycation or oxidation with or without 70% ethanolic extracts of Padma 28, Padma Circosan or with an active control. AGE and AOPP concentrations were analyzed fluorimetrically or spectrophotometrically respectively and by ELISA.ResultsCompared to the positive control Padma 28, Padma Circosan and the active control significantly reduced AGE levels by 58.6%, 56.7%, and 8.14% (fluorimetry) and by 35.48, 34.19, and 19.68% (ELISA). AOPP were reduced by 57.28/66.78% (30’/60’ incubation), by 67.08/71.99%, and by 81.68/86.54% (spectrophotometry) or by 79.98/86.97%, 79.3/84.3% and 77.07/90.31% (ELISA). All results are significantly different (p < 0.001). No difference was found between the effects of the two preparations.ConclusionBoth formulas significantly inhibited the formation of AGE and AOPP to a similar extent as the active controls. This suggests a possible role for both Padma preparations in the treatment and prevention of diabetes associated diseases.

Effect of tempol on redox homeostasis and stress tolerance in mimetically aged Drosophila.

We aimed to test our hypothesis that scavenging reactive oxygen species (ROS) with tempol, a membrane permeable antioxidant, affects the type and magnitude of oxidative damage and stress tolerance through mimetic aging process in Drosophila. Drosophila colonies were randomly divided into three groups: (1) no D-galactose, no tempol; (2) D-galactose without tempol; (3) D-galactose, but with tempol. Mimetic aging was induced by d-galactose administration. The tempol-administered flies received tempol at the concentration of 0.2% in addition to d-galactose. Thiobarbituric acid reacting substance (TBARS) concentrations, advanced oxidation protein products (AOPPs), Cu,Zn-superoxide dismutase (Cu,Zn-SOD), sialic acid (SA) were determined. Additionally, stress tolerances were tested. Mimetically aged group without tempol led to a significant decrease in tolerance to heat, cold, and starvation (P < 0.05), but tempol was used for these parameters. The Cu,Zn-SOD activity and SA concentrations were lower in both mimetically aged and tempol-administered Drosophila groups compared to control (P < 0.05), whereas there were no significantly difference between mimetically aged and tempol-administered groups. Mimetically aged group without tempol led to a significant increase in tissue TBARS and AOPPs concentrations (P < 0.05). Coadministration of tempol could prevent these alterations. Scavenging ROS using tempol also restores redox homeostasis in mimetically aged group. Tempol partly restores age-related oxidative injury and increases stress tolerance.

Oxidative stress status in elite athletes engaged in different sport disciplines

Exercise training may increase production of free radicals and reactive oxygen species in different ways. The training type and intensity may influence free radicals production, which leads to differences in oxidative stress status between athletes, but the results of the previous studies are incosistent. The aim of our study was to estimate oxidative stress status in elite athletes engaged in different sport disciplines. The study included 39 male highly skilled professional competitors with international experience (2 Olympic players): 12 wrestlers, 14 soccer players and 13 basketball players in whom we determined the levels of advanced oxidation protein products (AOPP) and malondialdehyde (MDA), as markers of oxidative stress and the total antioxidative capacity (ImAnOX) using commercially available assay kits. The mean AOPP concentration was not significantly different between soccer players, wrestler and basketball players (60.0 ± 23.0 vs. 68.5 ± 30.8 and 80.72 ± 29.1 μmol/L respectively). Mean ImAnOX concentration was not different between soccer players (344.8 ± 35.6 μmol/L), wrestlers (342.5 ± 36.2 μmol/L) and basketball players (347.95 ± 31.3 μmol/L). Mean MDA concentration was significantly higher in basketball players (1912.1 ± 667.7 ng/mL) compared to soccer players (1060.1 ± 391.0 ng/mL, p=0.003). In spite of this fact, oxidative stress markers levels were increased compared to referral values provided by the manufacturer. Type of sports (soccer, wrestler or basketball) have no impact on the levels of oxidative stress markers. Elite sports engagement is a potent stimulus of oxidative stress that leads to the large recruitment of antioxidative defense. Oxidative stress status monitoring followed by appropriate use of antioxidants is recommended as a part of training regime.

Manganese Superoxide Dismutase (SOD2) Polymorphisms, Plasma Advanced Oxidation Protein Products (AOPP) Concentration and Risk of Kidney Complications in Subjects with Type 1 Diabetes

AimsOxidative stress is involved in the pathophysiology of diabetic nephropathy. Manganese superoxide dismutase (SOD2) catalyses the dismutation of superoxide, regulates the metabolism of reactive oxygen species in the mitochondria and is highly expressed in the kidney. Plasma concentration of advanced oxidation protein products (AOPP), a marker of oxidative stress, was found to be increased in patients with kidney disease. We investigated associations of SOD2 allelic variations, plasma SOD activity and AOPP concentration with diabetic nephropathy in type 1 diabetic subjects.MethodsEight SNPs in the SOD2 region were analysed in 1285 Caucasian subjects with type 1 diabetes from the SURGENE prospective study (n = 340; 10-year follow-up), GENESIS (n = 501) and GENEDIAB (n = 444) cross-sectional studies. Baseline plasma concentration of AOPP and SOD activity were measured in GENEDIAB participants. Hazard ratio (HR) and odds ratio (OR) were determined for incidence and prevalence of nephropathy. Analyses were adjusted or stratified by retinopathy stages.ResultsIn the SURGENE cohort, the T-allele of rs4880 (V16A) was associated with the incidence of renal events (new cases, or the progression to a more severe stage of nephropathy; HR 1.99, 95% CI 1.24–3.12, p = 0.004) and with the decline in estimated glomerular filtration rate (eGFR) during follow-up. Similar associations were observed for rs2758329 and rs8031. Associations were replicated in GENESIS/GENEDIAB cohorts, in the subset of participants without proliferative retinopathy, and were confirmed by haplotype analyses. Risk allele and haplotype were also associated with higher plasma AOPP concentration and lower SOD activity.Conclusions SOD2 allelic variations were associated with the incidence and the progression of diabetic nephropathy, with a faster decline in eGFR and with plasma AOPP concentration and SOD activity in subjects with type 1 diabetes. These results are consistent with a role for SOD2 in the protection against oxidative stress and kidney disease in type 1 diabetes.

The influence of the occupational exposure to heavy metals and tobacco smoke on the selected oxidative stress markers in smelters.

The aim of the study was to verify if there is any association between exposure to Cu, Zn, Cd, Pb, As and the formation of malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), advanced oxidation protein products (AOPP), and whether in this process cigarette smoking plays a role. The investigations were performed in the 352 smelters occupationally exposed to heavy metals and 73 persons of control group. Metals concentration was determined by atomic absorption spectrometry. MDA and AOPP concentrations were determined by spectrophotometric methods. The concentration of 8-OHdG was determined by ELISA method. It was demonstrated an increased Cu concentration in smoking smelters compared to non-smoking control group. It was noted no differences in Zn and Mg concentrations between the examined groups. Pb concentration was more than sixfold higher in the group of smoking smelters and about fivefold higher in the group of non-smoking smelters compared to the control groups (smokers and non-smokers). It was shown that Cd concentration in the blood was nearly fivefold higher in the smoking control group compared to the non-smoking control group and more than threefold higher in the group of smoking smelters compared to non-smoking. It was shown an increased As concentration (more than fourfold) and decreased Ca concentration in both groups of smelters compared to control groups. In groups of smelters (smokers and non-smokers), twofold higher MDA and AOPP concentrations, and AOPP/albumin index compared to control groups (smokers and non-smokers) were shown. Tobacco smoke is the major source of Cd in the blood of smelters. Occupational exposure causes accumulation of Pb in the blood. Occupational exposure to heavy metals causes raise of MDA concentration and causes greater increase in AOPP concentration than tobacco smoke.