Plasma lipid hydroperoxides measurement by an automated xylenol orange method

Fate, subcellular distribution and biological effects of rare earth elements in a freshwater bivalve under complex exposure

Rare earth elements (REE) are emerging contaminants due to their increased use in diverse applications including cutting-edge and green-technologies. Their environmental concerns and contradicting results concerning their biological effects require an extensive understanding of REE ecotoxicology. Thus, we have studied the fate, bioaccumulation and biological effects of three representative REE, neodymium (Nd), gadolinium (Gd) and ytterbium (Yb), individually and in mixture, using the freshwater bivalve Corbicula fluminea. The organisms were exposed for 96 h at 1 mg L-1 REE in the absence and presence of dissolved organic matter (DOM) reproducing an environmental contamination. Combined analysis of the fate, distribution and effects of REE at tissue and subcellular levels allowed a comprehensive understanding of their behaviour, which would help improving their environmental risk assessment. The bivalves accumulated significant concentrations of Nd, Gd and Yb, which were decreased in the presence of DOM likely due to the formation of REE-DOM complexes that reduced REE bioavailability. The accumulation of Nd, Gd and Yb differed between tissues, with gills > digestive gland ≥ rest of soft tissues > hemolymph. In the gills and in the digestive gland, Nd, Gd and Yb were mostly (>90 %) distributed among metal sensitive organelles, cellular debris and detoxified metal-rich granules. Gadolinium, Yb and especially Nd decreased lysosome size in the digestive gland and disturbed osmo- and iono-regulation of C. fluminea by decreasing Na concentrations in the hemolymph and Ca2+ ATPase activity in the gills. Individual and mixed Nd, Gd and Yb exhibited numerous similarities and some differences in terms of fate, accumulation and biological effects, possibly because they have common abiotic and biotic ligands but different affinities for the latter. In most cases, individual and mixed effects of Nd, Gd, Yb were similar suggesting that additivity approach is suitable for the environmental risk assessment of REE mixtures.

Effect of Supplementation of Lambs with Whole Cottonseed: Impact on Serum Biomarkers and Infection by Gastrointestinal Parasites under Field Conditions

The purpose of this trial was to evaluate serum levels of oxidative stress biomarkers and biochemical analytes in crossbred lambs during the rearing phase in an integrated crop-livestock system (ICLS) to control gastrointestinal parasites. The experiment used 36 crossbred lambs (cross: Ile de France × White Dorper × Texel) divided into two groups. The WCS group was supplemented with whole cottonseed (WCS), and controls had no supplementation. Body weight, blood collection, and fecal analysis of nematode eggs and Eimeria oocysts counting per gram of feces were performed for each animal within 84 days of experiment. The following serum analytes were determined: total protein, albumin, globulin, cholesterol, haptoglobin, and 10 oxidative stress biomarkers: cupric reducing antioxidant capacity, ferric reducing ability of plasma, trolox equivalent antioxidant capacity, thiol, uric acid, paraoxonase-1, total oxidant status, ferric-xylenol orange, advanced oxidation protein products, and reactive oxygen metabolites derived compounds. The inclusion of WCS suggested the benefit in controlling infection as well as inducing an increase in antioxidants and a decrease in oxidants in lambs naturally infected by gastrointestinal parasites. The combination of WCS and ICLS could be a useful tool in controlling gastrointestinal parasite infection without affecting the production performance.

Effect of Cadmium on Oxidative Stress Indices and Vitamin D Concentrations in Children

Heavy metal poisoning can have serious health consequences, including damage to the brain, kidneys, and other organs. Cadmium is a toxic heavy metal that can accumulate in the body over time and the exposure to this element has been linked to a variety of adverse health effects. Cadmium toxicity can lead to an imbalance in the cellular redox state and be a source of oxidative stress. On the molecular level, cadmium ions negatively affect cellular metabolism, including the disruption of energy production, protein synthesis, and DNA damage. The study has been carried out on a group of 140 school-age children (8 to 14 years old) inhabiting the industrialized areas of Upper Silesia. The study population was divided into two sub-groups based on the median concentration of cadmium in blood (0.27 µg/L): Low-CdB and High-CdB. Measured traits comprised blood cadmium levels (CdB) as well as a blood count and selected oxidative stress markers. This research study aimed to demonstrate a correlation between the impact of exposure to elevated cadmium concentrations in a population of children and certain markers of oxidative stress, and 25-OH vitamin D3 concentration. A negative correlation has been found between cadmium concentration and 25-OH vitamin D3 level, protein sulfhydryl groups content in blood serum, glutathione reductase activity, and lipofuscin and malondialdehyde levels in erythrocytes. The concentration of 25-OH vitamin D₃ in the High-CdB group was decreased by 23%. The oxidative stress indices can be considered a valuable indicator of early Cd-toxicity effects to be included in the routinely-applied cadmium exposure monitoring parameters, allowing the evaluation of stress intensity to the cell metabolism.

Fecal microbiota and inflammatory and antioxidant status of obese and lean dogs, and the effect of caloric restriction

Introduction

Obesity is the most common nutritional disease in dogs, and is generally managed by caloric restriction. Gut microbiota alteration could represent a predisposing factor for obesity development, which has been associated with a low-grade inflammatory condition and an impaired antioxidant status. Besides, weight loss has been shown to influence the gut microbiota composition and reduce the inflammatory response and oxidative stress.

Method

However, these insights in canine obesity have not been fully elucidated. The aim of this study was to assess the differences in serum and inflammatory parameters, antioxidant status, fecal microbiota and bacterial metabolites in 16 obese and 15 lean client-owned dogs and how these parameters in obese may be influenced by caloric restriction. First, for 30 days, all dogs received a high-protein, high-fiber diet in amounts to maintain their body weight; later, obese dogs were fed for 180 days the same diet in restricted amounts to promote weight loss.

Results

Before the introduction of the experimental diet (T0), small differences in fecal microbial populations were detected between obese and lean dogs, but bacterial diversity and main bacterial metabolites did not differ. The fecal Dysbiosis Index (DI) was within the reference range (< 0) in most of dogs of both groups. Compared to lean dogs, obese dogs showed higher serum concentrations of acute-phase proteins, total thyroxine (TT4), and antioxidant capacity. Compared to T0, dietary treatment affected the fecal microbiota of obese dogs, decreasing the abundance of Firmicutes and increasing Bacteroides spp. However, these changes did not significantly affect the DI. The caloric restriction failed to exert significative changes on a large scale on bacterial populations. Consequently, the DI, bacterial diversity indices and metabolites were unaffected in obese dogs. Caloric restriction was not associated with a reduction of inflammatory markers or an improvement of the antioxidant status, while an increase of TT4 has been observed.

Discussion

In summary, the present results underline that canine obesity is associated with chronic inflammation. This study highlights that changes on fecal microbiota of obese dogs induced by the characteristics of the diet should be differentiated from those that are the consequence of the reduced energy intake.

Changes in Biomarkers of Redox Status in Saliva of Pigs after an Experimental Sepsis Induction

Saliva from pigs is gaining attention as an easy sample to obtain, being a source of biomarkers that can provide information on animal health and welfare. This study aimed to evaluate the changes that can occur in salivary biomarkers of the redox status of pigs with an experimentally induced sepsis. For that, the cupric reducing antioxidant capacity (CUPRAC), ferric reducing ability of saliva (FRAS), Trolox equivalent antioxidant capacity (TEAC), advanced oxidation protein products (AOPP), ferrous oxidation-xylenol orange (FOX), peroxide activity (POX-Act), and reactive oxygen-derived compounds (d-ROMs) were measured in the saliva of pigs with experimentally induced sepsis by endotoxin lipopolysaccharide (LPS), non-septic inflammation induced by turpentine, and in healthy individuals before and after 3 h, 6 h, 24 h, and 48 h. AOPP, POX-Act, and d-ROMs in the sepsis group were higher than in the control from 3 h to 24 h after the inoculation. CUPRAC, FRAS, and TEAC were higher in sepsis than the control group at 24 h. These changes were of higher magnitude than those that occurred in the turpentine group. In conclusion, our findings reveal that sepsis produces changes in salivary biomarkers of redox status, which opens the possibility of using them as potential biomarkers in this species.

Metabolic, cellular and defense responses to single and co-exposure to carbamazepine and methylmercury in Dreissena polymorpha

Carbamazepine (CBZ) and Hg are widespread and persistent micropollutants in aquatic environments. Both pollutants are known to trigger similar toxicity mechanisms, e.g. reactive oxygen species (ROS) production. Here, their effects were assessed in the zebra mussel Dreissena polymorpha, frequently used as a freshwater model in ecotoxicology and biomonitoring. Single and co-exposures to CBZ (3.9 μg L^-1) and MeHg (280 ng L^-1) were performed for 1 and 7 days. Metabolomics analyses evidenced that the co-exposure was the most disturbing after 7 days, reducing the amount of 25 metabolites involved in protein synthesis, energy metabolism, antioxidant response and osmoregulation, and significantly altering cells and organelles' structure supporting a reduction of functions of gills and digestive glands. CBZ alone after 7 days decreased the amount of α-aminobutyric acid and had a moderate effect on the structure of mitochondria in digestive glands. MeHg alone had no effect on mussels' metabolome, but caused a significant alteration of cells and organelles' structure in gills and digestive glands. Single exposures and the co-exposure increased antioxidant responses vs control in gills and digestive glands, without resulting in lipid peroxidation, suggesting an increased ROS production caused by both pollutants. Data globally supported that a higher number of hyperactive cells compensated cellular alterations in the digestive gland of mussels exposed to CBZ or MeHg alone, while CBZ + MeHg co-exposure overwhelmed this compensation after 7 days. Those effects were unpredictable based on cellular responses to CBZ and MeHg alone, highlighting the need to consider molecular toxicity pathways for a better anticipation of effects of pollutants in biota in complex environmental conditions.

Oxidative Stress Markers in Hypertrophic Cardiomyopathy

Background and Objectives: Hypertrophic cardiomyopathy (HCM) depends on the primary impairment of sarcomeres, but it can also be associated with secondary alterations in the heart related to oxidative stress. The present study aimed to examine oxidative-antioxidant disturbances in patients with HCM compared with control individuals. Materials and Methods: We enrolled 52 consecutive HCM patients and 97 controls without HCM. The groups were matched for age, body mass index, and sex. Peripheral blood was collected from all patients to determine the total antioxidant capacity (TAC), total oxidant status (TOS), lipid hydroperoxide (LPH), and malondialdehyde (MDA). The oxidative stress index (OSI) was defined as the ratio of the TOS level to the TAC level. Results: The median age was 52 years, and 58.4% were female. The area under the curve (AUC) indicated good predictive power for the TAC and TOS [AUC 0.77 (0.69–0.84) and 0.83 (0.76–0.90), respectively], as well as excellent predictive power for the OSI [AUC 0.87 (0.81–0.93)] for HCM detection. Lipid peroxidation markers also demonstrated good predictive power to detect HCM patients [AUC_LPH = 0.73, AUC_MDA = 0.79]. Conclusions: The TOS, the TAC, LPH levels, and MDA levels have good predictive power for HCM detection. The holistic assessment of oxidative stress by the OSI had excellent power and could identify patients with HCM.

Insulin-like Growth Factor II Prevents MPP+ and Glucocorticoid Mitochondrial-Oxidative and Neuronal Damage in Dopaminergic Neurons

Stress seems to contribute to Parkinson’s disease (PD) neuropathology, probably by dysregulation of the hypothalamic–pituitary–adrenal axis. Key factors in this pathophysiology are oxidative stress and mitochondrial dysfunction and neuronal glucocorticoid-induced toxicity. The insulin-like growth factor II (IGF-II), a pleiotropic hormone, has shown antioxidant and neuroprotective effects in some neurodegenerative disorders. Our aim was to examine the protective effect of IGF-II on a dopaminergic cellular combined model of PD and mild to moderate stress measuring oxidative stress parameters, mitochondrial and neuronal markers, and signalling pathways. IGF-II counteracts the mitochondrial-oxidative damage produced by the toxic synergistic effect of corticosterone and 1-methyl-4-phenylpyridinium, protecting dopaminergic neurons from death and neurodegeneration. IGF-II promotes PKC activation and nuclear factor (erythroid-derived 2)-like 2 antioxidant response in a glucocorticoid receptor-dependent pathway, preventing oxidative cell damage and maintaining mitochondrial function. Thus, IGF-II is a potential therapeutic tool for treatment and prevention of disease progression in PD patients suffering mild to moderate emotional stress.

Assessing Photosensitized Membrane Damage: Available Tools and Comprehensive Mechanisms

Lipids are important targets of the photosensitized oxidation reactions, forming important signaling molecules, disorganizing and permeabilizing membranes, and consequently inducing a variety of biological responses. Although the initial steps of the photosensitized oxidative damage in lipids are known to occur by both Type I and Type II mechanisms, the progression of the peroxidation reaction, which leads to important end-point biological responses, is poorly known. There are many experimental tools used to study the products of lipid oxidation, but neither the methods nor their resulting observations were critically compared. In this article, we will review the tools most frequently used and the key concepts raised by them in order to rationalize a comprehensive model for the initiation and the progression steps of the photoinduced lipid oxidation.

Changes in salivary biomarkers of oxidative status in calves at weaning and grouping

BACKGROUND

Saliva is being increasingly used as a sample for measuring biomarkers in several species and shows a high potential of use to detect and monitor stress. The weaning and grouping in dairy calves are a particularly stressful time. Therefore, the objectives of this study were to evaluate a panel of antioxidant and oxidant biomarkers in the saliva of calves on the day of weaning (W0), 2 days after weaning or milk withdrawal (W + 2), and 4 days after grouping (G + 4). In addition, to verify if cortisol and oxytocin concentrations are related to the biomarkers measured.

RESULTS

Salivary cupric reducing antioxidant capacity (CUPRAC), ferric reducing ability of saliva (FRAS), Trolox equivalent antioxidant capacity (TEAC), advanced oxidation protein products (AOPP), and ferrous oxidation-xylenol orange (FOX) were significantly higher (P < 0.02) 4 days after grouping than the day of weaning and 2 days after. The increases were 50 and 54% for CUPRAC, 93 and 116% for FRAS, 117 and 135% for TEAC, 22 and 49% for AOPP and 10 and 5% for FOX in comparison with weaning and 2 days after, respectively. In addition, oxytocin and cortisol showed significant negative and positive correlations (P < 0.05) respectively with the biomarkers of oxidative status.

CONCLUSIONS

Our results showed that calves after grouping show increases in antioxidants and oxidants concentrations, indicating that a balance between these molecules has been tried to maintain during this stressful situation. The dynamic changes of biomarkers of oxidative status should be explored and characterised in other stressful conditions.

Relationship between lead absorption and iron status and its association with oxidative stress markers in lead-exposed workers

BACKGROUND

The emission of lead (Pb) occurring during the extraction, processing and industrial applications of this element remains a significant environmental risk factor. The absorbability of lead in humans is strongly associated with the general health status of exposed individuals. Existing mineral deficiencies are considered being a predisposition to an increased Pb uptake. Both, iron deficiency and lead poisoning are the major causative factors responsible for the prevalence of anemia within the vulnerable population, especially in children. Although some of the intervention programs of counteracting lead poisoning by iron supplementation proved to be effective in the Pb-exposed population, the exact mechanisms of this interaction still require further studies. The objective of the presented study was to examine the association of iron level on oxidative stress measures and its effects on the severity of lead toxicity in the exposed population.

METHODS

The analyzed population consisted of 270 male workers from the lead-zinc smelter. The studied population was divided into two sub-groups based on the serum iron concentration: low iron level group (L-Fe; Fe < median value) and high iron level group (H-Fe; Fe > median value). Measured traits comprised of blood lead (PbB), serum Fe and zinc protoporphyrin (ZPP) levels as well as a blood count and oxidative stress markers.

RESULTS

No significant correlation between serum iron concentration and PbB in the tested cohort was found. On the contrary, the analysis of ZPP levels (long-term marker related to a hematologic toxic effect of Pb) within the subgroups differing in serum Fe level shown that ZPP was 12.3 % lower (p = 0.043) in subjects classified within the H-Fe group. A positive correlation of serum Fe and total antioxidant capacity (TAC) was found (R = 0.1999). The conducted 3-D PCA analysis showed that individuals classified within the H-Fe group were characterized by the co-occurrence of higher Fe levels, lower ZPP, and higher TAC value.

CONCLUSION

These results support the existing evidence providing that maintaining the optimal status of Fe may play a significant role in preventing the lead poisoning and alleviating harmful effects of Pb on the oxidative balance in humans.

A Systematic Review of the Cardiometabolic Benefits of Plant Products Containing Mixed Phenolics and Polyphenols in Postmenopausal Women: Insufficient Evidence for Recommendations to This Specific Population

Menopause is characterized by endocrine and physiological changes and is often accompanied by increased body weight and cholesterol, glucose intolerance, and/or hypertension. These alterations are associated with increased risk for cardiovascular diseases (CVDs) and Type II diabetes mellitus (T2DM) that may be moderate by dietary plant phenolic compounds. In this review, we examine the current evidence of the impact of a variety of plant products (foods, extracts, beverages) rich in a mixture of phenolics and polyphenols on: (i) glucose and insulin levels; (ii) lipid profile; (iii) blood pressure; and (iv) biomarkers of inflammation and oxidative stress in postmenopausal women. We critically evaluate both the results of a range of intervention studies conducted in this specific subpopulation and the level of evidence supporting the benefits of consuming those products after the menopause. Overall, the current available evidence does not allow for specific dietary recommendations of these plant products rich in phenolics and polyphenols in this high-risk subpopulation. Our data show rather variable and small effects of the different products examined on the cardiometabolic biomarkers and further support the need to: (1) improve the quality of the study designs and data reporting; and (2) understand the variability in the response of the different biomarkers and establish clear differences between healthy and cardiometabolic disease levels.

Changes in Serum Thiol-Disulphide Homeostasis in Sheep with Gastrointestinal Nematodes

Simple Summary

Parasitism with gastrointestinal nematodes represents a significant risk to the health of livestock populations. Besides the local oxidative damage caused by the parasite, the host reacts by increasing the production of oxidants. The study of thiol-disulphide homeostasis can be of help in the evaluation of the oxidative status of sheep during this type of parasitism. In this study, the thiol-disulphide homeostasis, together with other biomarkers of oxidative stress and inflammation, were assessed in the serum of lambs infected with gastrointestinal nematodes and were evaluated after 70 days of integrated crop-livestock system and anthelmintic treatment. This study showed that the thiol-disulphide balance was impaired in the infected lambs and the changes were correlated with the parasite load, which therefore could indicate their potential use as a tool to evaluate and monitor the disease in sheep.

Abstract

This work aimed to evaluate the thiol-disulphide homeostasis in serum of lambs naturally infected by gastrointestinal nematodes presenting different levels of parasite load indirectly indicated by faecal worm egg counts (EPG). Furthermore, the possible changes in the thiol-disulphide dynamic after different procedures to reduce the parasitic charge, such as the integrated crop-livestock system or anthelmintic treatment, were assessed. The results were compared with a panel of various oxidative stress and inflammatory biomarkers. The lambs were divided into three groups: animals highly infected (EPG higher than 5000) and packed cell volume (PCV) lower than 24% (G1); animals highly infected (EPG higher than 5000) and normal PCV (>24%) (G2); and animals presenting EPG lower than 5000 and normal PCV (>24%) (G3). The highly infected lambs (G1 and G2) showed lower total thiol (TT) and native thiol (SH) (p ≤ 0.01) than those from G3. After treatment, TT and SH increased significantly in all groups (p ≤ 0.01), and the disulphide (SS)/TT and SS/SH ratios decreased significantly (p < 0.01) in G1 and G2. These results show that the thiol-disulphide balance was impaired in lambs infected by gastrointestinal nematodes and that it could be potentially used as a biomarker to monitor this disease.

Spectrophotometric assays for evaluation of Reactive Oxygen Species (ROS) in serum: general concepts and applications in dogs and humans

Reactive oxygen species (ROS) are reactive compounds derived from oxygen. In biological systems, an excessive amount of ROS can cause oxidative damage to biological macromolecules being involved in different diseases. Several assays have been developed in the last 30 years for ROS evaluation. The objective of this article will be to provide an update about the spectrophotometric methods currently used in the assessment of ROS in serum. The chemical basis of four different techniques will be reviewed, and examples of their possible applications will be provided. A particular emphasis about the practical applications of these assays in the dog will be made, but selected information about their use in humans will also be presented for comparative purposes, following a One-Health approach. The information about the spectrophotometric assays presented in this paper should be interpreted with caution once limited information about them is available yet, and further studies should be performed to clarify what they measure and their clinical application. Ideally, when applied to evaluate a sample's oxidative status, they should be incorporated in a panel of analytes where other oxidants, antioxidants, and biomarkers of inflammation were also included.

Blood Magnesium Level and Selected Oxidative Stress Indices in Lead-Exposed Workers

Occupational exposure to lead is one of the important hazards to human global population. Lead interferes with divalent cations, such as calcium, magnesium, and iron. Magnesium is the fourth most common mineral in the human body and a cofactor in more than 325 enzymes. There are many disorders associated with magnesium deficiency. It has been postulated that hypomagnesemia promotes oxidative stress. Study population included 232 male employees of lead-zinc works and was divided into two sub-groups based on the median of magnesium serum level: low magnesium level (L-Mg) group and high magnesium level (H-Mg) group. Magnesium level was significantly higher in the H-Mg group than in the L-Mg group due to the study design. The level of zinc protoporphyrin was significantly higher in the L-Mg group than in the H-Mg group by 13%, while the blood lead levels were similar in the examined groups. The serum level of MDA was significantly higher in the L-Mg group than in the H-Mg group by 12%, while the serum levels of thiol groups, TAC, and bilirubin were significantly lower in that group by 6%, 3%, and 27%, respectively. Similarly, the erythrocyte SOD activity was lower in the L-Mg group than in the H-Mg group by 5%. Low serum magnesium levels contribute to lead-induced oxidative stress, result in unfavorable modification of antioxidant system function, and promote lead-induced impairment of heme synthesis. Obtained results indicate that prevention of hypomagnesemia should be regarded as an important step in ensuring adequate prophylaxis of chronic lead poisoning.

Association of Metabolically Healthy and Unhealthy Obesity Phenotypes with Oxidative Stress Parameters and Telomere Length in Healthy Young Adult Men. Analysis of the MAGNETIC Study

Obesity is a significant factor related to metabolic disturbances that can lead to metabolic syndrome (MetS). Metabolic dysregulation causes oxidative stress, which affects telomere structure. The current study aimed to evaluate the relationships between telomere length, oxidative stress and the metabolically healthy and unhealthy phenotypes in healthy young men. Ninety-eight participants were included in the study (49 healthy slim and 49 obese patients). Study participants were divided into three subgroups according to body mass index and metabolic health. Selected oxidative stress markers were measured in serum. Relative telomere length (rTL) was measured using quantitative polymerase chain reaction. The analysis showed associations between laboratory markers, oxidative stress markers and rTL in metabolically healthy and unhealthy participants. Total oxidation status (TOS), total antioxidant capacity (TAC) and rTL were significantly connected with metabolically unhealthy obesity. TAC was associated with metabolically healthy obesity. Telomeres shorten in patients with metabolic dysregulation related to oxidative stress and obesity linked to MetS. Further studies among young metabolically healthy and unhealthy individuals are needed to determine the pathways related to metabolic disturbances that cause oxidative stress that leads to MetS.

Changes in Serum Biomarkers of Oxidative Stress in Cattle Vaccinated with Tick Recombinant Antigens: A Pilot Study

Tick vaccination is an environmentally friendly alternative for tick control, pathogen infection, and transmission. Tick vaccine protection is sometimes incomplete, which may be due to problems in the stability, conformation, and activity of antibodies. This might be related to oxidative stress, but more studies are needed about the possible relationships between oxidative stress and immune function. The objective of this study was to evaluate and compare various serum biomarkers of antioxidant response and oxidative damage in cattle vaccinated with two recombinant antigens, the chimera of Subolesin- BM95 (homologue antigen of BM86)-MSP1a and BM86, and a control consisting in the adjuvant of the vaccines. Cupric reducing antioxidant capacity (CUPRAC), ferric reducing ability of the plasma (FRAP), trolox equivalent antioxidant capacity (TEAC), total thiol concentrations, and uric acid were evaluated in serum to determine the antioxidant response. To evaluate oxidative status, ferrous oxidation-xylenol orange (FOX), total oxidant status (TOS), advanced oxidation protein products (AOPP) and hydrogen peroxide (H₂O₂) concentrations in serum were determined. In addition, correlations between biomarkers of oxidative stress and antibody titers were evaluated. A significant decrease in all antioxidant biomarkers, with exception of thiol, and also a decrease in the oxidant markers TOS, AOPP and H₂O₂ was observed in cattle vaccinated with BM86, that also showed the highest antibody titers response whereas no significant differences in any of the biomarkers were detected in the Subolesin-Bm95-MSP1a and control groups. In addition, the dynamics of Cuprac and H₂O₂ with time showed significant differences between the groups. Although this is a pilot study and the results should be interpreted with caution and corroborated by studies involving a large number of animals, our results indicate that, in our experimental conditions, those vaccines able to induce a lower oxidative stress produce a higher concentration of antigen-specific antibodies. Overall, the results of the study provided information on the behavior of different biomarkers related to antioxidant defense, and the oxidative damage in cattle in response to vaccination.

Fast, direct and in situ monitoring of lipid oxidation in an oil-in-water emulsion by near infrared spectroscopy

Lipid oxidation has implications on food, cosmetics and other fat containing products. Fatty acid autoxidation alters both the quality and safety of these products. Efficient and fast methods are needed to track lipid oxidation in complex systems. In this study, an oil-in-water emulsion (20% v/v of fish oil stabilized with high oleic sunflower lecithin) was subjected to iron-initiated oxidation. Conjugated dienes (CDs) were measured after fat extraction using a standardized method. Near infrared spectroscopy (NIRS) has been used to record chemical changes occurring during oxidation directly in the emulsion. Variations were noticed in different spectral regions. Partial least squares regression (PLSR) revealed correlations between conjugated diene values and NIRS spectra. High coefficients of determination (R2 = 0.967 and 0.996) were found for calibration and prediction respectively. The CD value was predicted from NIRS spectra with an error of 7.26 mmol eq. LH kg-1 oil (7.8% error). Limits of detection (LOD) and quantification (LOQ) of 4.65 and 15.5 mmol eq. LH kg-1 oil were estimated. NIRS is a rapid and simple method for measuring lipid oxidation (CD value) in an emulsion without prior fat extraction. NIRS can replace the reference methods that use hazardous solvents and consume time. Therefore, NIRS enables in-line monitoring for process and quality control.

Modulation of inter-organ signalling in obese mice by spontaneous physical activity during mammary cancer development

Accumulative evidence links breast cancer development to excess weight and obesity. During obesity, dysregulations of adipose tissue induce an increase in pro-inflammatory adipokine secretions, such as leptin and oestrogen secretions. Furthermore, a raise in oxidative stress, along with a decrease in antioxidant capacity, induces and maintains chronic inflammation, which creates a permissive environment for cancer development. Physical activity is recommended as a non-pharmacological therapy in both obese and cancer situations. Physical activity is associated with a moderation of acute inflammation, higher antioxidant defences and adipokine regulation, linked to a decrease of tumour-cell proliferation. However, the biological mechanisms underlying the relationship between oxidative stress, low-grade inflammation, carcinogenesis, obesity and physical activity are poorly understood. Our study is based on old, ovariectomised mice (C57BL/6J mice, 33 weeks old), fed with a high fat diet which increases adipose tissue favouring overweight and obesity, and housed in either an enriched environment, promoting physical activity and social interactions, or a standard environment constituting close to sedentary conditions. Our model of mammary carcinogenesis allowed for the exploration of tissue secretions and signalling pathway activation as well as the oxidative status in tumours to clarify the mechanisms involved in a multiple factorial analysis of the data set. The multiple factorial analysis demonstrated that the most important variables linked to moderate, spontaneous physical activity were the increase in growth factor (epithelial growth factor (EGF), hepatocyte growth factor (HGF)) and the activation of the signalling pathways (STAT3, c-jun n-terminal kinases (JNK), EKR1/2, nuclear factor-kappa B (NF-κB)) in the gastrocnemius (G). In inguinal adipose tissue, the NF-κB inflammation pathway was activated, increasing the IL-6 content. The adiponectin plasma (P) level increased and presented an inverse correlation with tumour oxidative status. Altogether, these results demonstrated that spontaneous physical activity in obesity conditions could slow down tumour growth through crosstalk between muscle, adipose tissue and tumour. A spontaneous moderate physical activity was able to modify the inter-organ exchange in a paracrine manner. The different tissues changed their signalling pathways and adipokine/cytokine secretions, such as adiponectin and leptin, resulting in a decrease in anti-oxidative response and inflammation in the tumour environment. This model showed that moderate, spontaneous physical activity suppresses tumour growth via a dialogue between the organs close to the tumour.

Circulating biomarkers of antioxidant status and oxidative stress in people with cystic fibrosis: A systematic review and meta-analysis

Introduction

Oxidative stress may play an important role in the pathophysiology of cystic fibrosis (CF). This review aimed to quantify CF-related redox imbalances.

Methods

Systematic searches of the Medline, CINAHL, CENTRAL and PsycINFO databases were conducted. Mean content of blood biomarkers from people with clinically-stable CF and non-CF controls were used to calculate the standardized mean difference (SMD) and 95% confidence intervals (95% CI).

Results

Forty-nine studies were eligible for this review including a total of 1792 people with CF and 1675 controls. Meta-analysis revealed that protein carbonyls (SMD: 1.13, 95% CI: 0.48 to 1.77), total F₂-isoprostane 8-iso-prostaglandin F_2α (SMD: 0.64, 95% CI: 0.23 to 1.05) and malondialdehyde (SMD: 1.34, 95% CI: 0.30 to 2.39) were significantly higher, and vitamins A (SMD: −0.66, 95% CI -1.14 to −0.17) and E (SMD: −0.74, 95% CI: −1.28 to −0.20), β-carotene (SMD: −1.80, 95% CI: −2.92 to −0.67), lutein (SMD: −1.52, 95% CI: −1.83 to −1.20) and albumin (SMD: −0.98, 95% CI: −1.68 to −0.27) were significantly lower in the plasma or serum of people with CF versus controls.

Conclusions

This systematic review and meta-analysis found good evidence for reduced antioxidant capacity and elevated oxidative stress in people with clinically-stable CF.

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Blood biomarkers of oxidative stress were elevated in stable CF vs non-CF controls.

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Lipid peroxidation was positively correlated with age and immune cell count in CF.

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Antioxidants vitamins A & E, β-carotene, lutein and albumin were lower in stable CF.

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Antioxidants were positively correlated with body mass index and lung function in CF.

Potential Antioxidant Activity of Calcium and Selected Oxidative Stress Markers in Lead- and Cadmium-Exposed Workers

Occupational lead (Pb) and cadmium (Cd) exposure occurs during processing and casting of nonferrous metals such as zinc. In contrast to Pb and Cd, Ca is essential for living organisms due to its important role in a multitude of functions, from cell signaling to bone growth. Pb and Cd exposure affects calcium metabolism in various ways. The aim of this study was to investigate the blood levels of Pb, Cd, and Ca and the levels of selected oxidative stress biomarkers in workers exposed to Pb and Cd. Population groups included 264 male employees in a lead-zinc smelter. The study population was divided into two subgroups based on the median of Ca serum level (2.42 mmol/l): the low-Ca-level group (L-Ca group) and the high-Ca-level group (H-Ca group). Ca level was significantly higher in the H-Ca group than in the L-Ca group due to the study design (by 26%). The level of zinc protoporphyrin (ZPP) was significantly higher in the L-Ca group than in the H-Ca group by 13%, while the blood lead levels (PbB) were similar in the examined groups. The level of cadmium (CdB) was significantly higher in the L-Ca group than in the H-Ca group by 33%. From oxidative stress markers in serum, only the levels of malondialdehyde (MDA) and ceruloplasmin (CER) were significantly higher in the L-Ca group than in the H-Ca group, by 12% and 4%, respectively. The correlation analysis showed negative correlations between Ca level and the levels of PbB, ZPP, CdB, and MDA. The presented results indicate that Ca level modulates the serum concentration of Cd and has an impact on Pb-induced impairment of heme synthesis. The higher Ca levels may lead to a decrease in the concentration of lipid peroxidation products. Moreover, serum calcium level seems to be able to modify the level of acute-phase proteins. Obtained results suggest that higher Ca level may be useful in reducing Cd level in occupationally exposed workers.

THE EFFECT OF ANTITHYROID DRUGS ON OSTEOPONTIN AND OXIDATIVE STRESS IN GRAVES' DISEASE

OBJECTIVE

The aim of the present study is to evaluate the effects of methimazole (MTZ) and propylthiouracil (PTU) treatments on osteopontin (OPN) and oxidative stress in Graves' disease (GD).

MATERIAL AND METHODS

The study included 60 cases with GD in hyperthyroid state and taking no antithyroid treatment, and 30 healthy volunteers. GD patients were randomly separated into two groups; 30 of them took PTU, and the other 30 took MTZ treatments. Blood samples were taken from the patients with GD before the treatment, and three months after the treatment was begun, when they were in the euthyroid state; blood samples of the healthy control subjects were also taken at these times.

RESULTS

TAS and OSI levels before treatment were significantly higher in the GD group, when compared to the control group (p<0.001, for each). GD subjects taking PTU treatment had significantly higher TAS levels (p=0.001), and significantly lower TOS and OSI levels (p=0.008 and p=0.001, respectively). TAS levels significantly decreased in the patients taking MTZ treatment (p=0.029), but TOS and OSI levels did not change significantly (p>0.05). Pretreatment OPN levels were significantly higher in GD patients, when compared to the control group (p=0.014). OPN level significantly decreased in the GD group taking PTU treatment; however OPN levels in the group taking MTZ treatment did not change significantly when compared to the pretreatment value.

CONCLUSION

PTU treatment is more effective in decreasing OPN and oxidative stress in GD patients, when compared to the MTZ treatment.

Oxidant-Antioxidant balance in patients with coronary slow flow

OBJECTIVE

Recent studies have focused on the probable role of oxidative stress in cardiovascular diseases. We aimed to assess the oxidant/antioxidant biomarkers in coronary slow flow (CSF).

METHODS

The study included 51 subjects with CSF and age and sex matched 32 controls. Detailed anamnesis of the patients in the study was taken and routine physical examinations were performed. Routine biochemical blood tests were analyzed. Total oxidative status (TOS), oxidative stress index (OSI) and lipid hydroxyperoxide (LOOH) levels as oxidant biomarkers; paraoxonase (PON1), ceruloplasmin (CP), free sulphydryl (SH) groups, and total antioxidant capacity (TAS) levels as antioxidant biomarkers were studied.

RESULTS

Baseline demographic characteristics of the study population did not differ significantly between groups.TOS, OSI and LOOH concentrations were higher in study group than in control group. However, there was no significant difference detected in levels of TAS, PON1, SH and CP. Multivariate logistic regression analysis revealed that TOS, hsCRP and smoking were indepedent risk factors of CSF.

CONCLUSIONS

Although there was not any significant difference in antioxidant biomarkers (TAS, PON1, SH and CP) in CSF patients, we detected increased TOS, OSI and LOOH levels which have oxidant properties. These data supported the possible involvement of oxidative stress in pathogenesis of CSF as previous studies reported.

Activation of antioxidant defences of human mammary epithelial cells under leptin depend on neoplastic state

BACKGROUND

Obesity is associated with oxidative stress, a major factor in carcinogenesis, and with high leptin concentration. The aim of this study was to determine the effects of leptin on the antioxidant response in three human mammary epithelial cells each presenting a different neoplastic status: healthy human mammary epithelial cells (HMEC), oestrogen-receptor positive MCF-7 cells and triple-negative MDA-MB-231 cells.

METHODS

This in vitro kinetic study characterized the cell antioxidant response after 1, 6 and 24 h in the presence of leptin (10 or 100 ng/ml).The antioxidant response was defined in terms of cell glutathione content, gene expression and catalytic activity of antioxidant enzymes (i.e. glutathione peroxidase 1 (Gpx1), glutathione reductase (GR), glutathione S transferase (GST), heme-oxygenase 1 (HO-1) and cyclooxygenase-2 (COX-2)). Oxidative stress occurrence was assessed by lipid hydro peroxide (HPLIP) and isoprostane concentrations in culture media at 24 h.

RESULTS

At both concentrations used, leptin induced ROS production in all cell models, contributing to various antioxidant responses linked to neoplastic cell status. HMEC developed a highly inducible antioxidant response based on antioxidant enzyme activation and an increase in cell GSH content at 10 ng/ml of leptin. However, at 100 ng/ml of leptin, activation of antioxidant response was lower. Conversely, in tumour cells, MCF-7 and MDA-MB-231, leptin did not induce an efficient antioxidant response, at either concentration, resulting in an increase of lipid peroxidation products.

CONCLUSIONS

Leptin can modulate the oxidative status of mammary epithelial cells differently according to their neoplastic state. These novel results shed light on oxidative status changes in mammary cells in the presence of leptin.

Paradoxical effects of vitamin C in Chagas disease

Trypanosoma cruzi infection stimulates inflammatory mediators which cause oxidative stress, and the use of antioxidants can minimize the sequelae of Chagas disease. In order to evaluate the efficacy of vitamin C in minimizing oxidative damage in Chagas disease, we orally administered ascorbic acid to Swiss mice infected with 5.0 × 10⁴ trypomastigote forms of T. cruzi QM2 strain. These animals were treated for 60 days to investigate the acute phase and 180 days for the chronic phase. During the acute phase, the animals in the infected and treated groups demonstrated lower parasitemia and inflammatory processes were seen in more mice in these groups, probably due to the higher concentration of nitric oxide, which led to the formation of peroxynitrite. The decrease in reduced glutathione concentration in this group showed a circulating oxidant state, and this antioxidant was used to regenerate vitamin C. During the chronic phase, the animals in the infected and treated group showed a decrease in ferric reducing ability of plasma and uric acid concentrations as well as mobilization of bilirubin (which had higher plasma concentration), demonstrating cooperation between endogenous non-enzymatic antioxidants to combat increased oxidative stress. However, lower ferrous oxidation in xylenol orange concentrations was found in the infected and treated group, suggesting that vitamin C provided biological protection by clearing the peroxynitrite, attenuating the chronic inflammatory process in the tissues and favoring greater survival in these animals. Complex interactions were observed between the antioxidant systems of the host and parasite, with paradoxical actions of vitamin C.

Selected serum oxidative stress biomarkers in dogs with non-food-induced and food-induced atopic dermatitis

BACKGROUND

Oxidative stress (OS) has been shown to be involved in the pathogenesis of human and canine atopic dermatitis (AD) through several distinct mechanisms. Selected serum biomarkers of OS (sbOS) have been validated in normal dogs and studied in several canine diseases. To the best of the authors' knowledge, the sbOS evaluated in this study have not previously been described in canine AD.

HYPOTHESIS/OBJECTIVES

The aims of the study were to evaluate a panel of sbOS in dogs with food-induced (FIAD) and non-food-induced (NFIAD) AD: cupric reducing antioxidant capacity (CUPRAC), ferrous oxidation-xylenol orange (FOX), ferric reducing ability of the plasma (FRAP), paraoxonase-1 (PON1), trolox equivalent antioxidant capacity (TEAC) and serum total thiol (THIOL). The aim was to compare these metabolites with those in healthy control dogs, and to correlate sbOS with validated pruritus and CADESI-04 severity scales in dogs with AD.

ANIMALS

Forty six healthy, nine NFIAD and three FIAD client-owned dogs were included.

METHODS

The study was designed as a cohort study.

RESULTS

There were significant differences in atopic dogs when compared to healthy dogs for all of the sbOS analysed.

CONCLUSIONS AND CLINICAL RELEVANCE

These findings suggest that OS could play a role in the pathogenesis of canine NFIAD and FIAD. In addition, the evaluation of sbOS could be useful for precision medicine to help to detect atopic dogs that might benefit from antioxidant-targeted therapies.

Effect of Intrauterine Infusion of Momordica Charantia L. on Oxidative Stress and Pregnancy Rate in Infertile Cows

Introduction

The effect of intrauterine administration of Momordica charantia L. (MC) extract on oxidative changes and pregnancy rate in infertile cows was investigated.

Material and Methods

Endometrial smear specimens were taken from 40 cows with fertility problems for cytological examination, and the cows were randomly divided into two groups: group I (n = 20) was subjected to intrauterine administration of 40 mL (0.25 g/mL) of MC extract, group II (n = 20) was subjected to intrauterine administration of 40 mL of pure olive oil. Blood samples were taken starting from the day of administration of MC extract or olive oil (day 0) and then for three weeks at weekly intervals (days 7, 14, 21). Blood serum samples were evaluated for total antioxidant capacity (TAS), total oxidant level (TOS), oxidative stress index (OSI), lipid hydroperoxide (LOOH), and nitric oxide (NO) levels. In addition, on the 14^th day following treatment, two doses of PGF2α were administrated to all cows at 14-day intervals. Following the second PGF2α administration, insemination and GnRH administration was performed at the 60^th h after PGF2α treatment. Smear samples were stained with Giemsa and immunohistochemically to determine cytological changes and inflammatory status.

Results

According to cytological findings, subclinical endometritis was a prevalent disorder in cows with infertility problem (82.5%; 33/40). Additionally, 60.6% (20/33) of the cows with subclinical endometritis had acute inflammation, whereas remaining 13 cows had chronic endometritis. Of the cows with subclinical endometritis, 50% (8/16) and 35% (6/17) became pregnant in group I and II, respectively (P > 0.05). Although the oxidative stress parameters showed similarities between both groups (P > 0.05), there was a significant difference (P < 0.001) between the groups in terms of mean NO and LOOH levels (NO - 31.20 ± 11.38 vs 44.53 ± 11.50 μmol/L and LOOH - 1.22 ± 0.37 vs 1.89 ± 0.36 μmol/L).

Conclusion

The obtained results indicated that MC administration, especially in the presence of active inflammation, may improve the pregnancy rate by positive reduction of oxidative changes.

Serum antioxidant capacity and oxidative damage in clinical and subclinical canine ehrlichiosis

The objective of this study was to evaluate and compare the antioxidant response and the products of oxidative damage analysed by various assays in clinical and subclinical canine monocytic ehrlichiosis (CME). For this purpose, four assays to measure the total serum antioxidant capacity (TAC), such as the cupric reducing antioxidant capacity (CUPRAC), ferric reducing ability of plasma (FRAP), trolox equivalent antioxidant capacity (TEAC) using acidic medium (TEAC_A), and the TEAC using the horseradish peroxidase (TEAC_H) were used. In addition, the serum thiol concentrations were analysed. Reactive oxygen species (ROS), thiobarbituric acid reactive substances (TBARS), and ferrous oxidation-xylenol orange (FOX) were measured to determine the concentrations of free radical and the products of oxidative damage as result of the disease. All antioxidant markers were significantly lower in the dogs on clinical ehrlichiosis when compared with healthy dogs; however only the CUPRAC, FRAP and thiol were significantly lower in subclinical CME compared with healthy dogs. TBARS and FOX showed no significant differences between dogs with CME and healthy dogs; however, a significant increased ROS concentration was observed in dogs with clinical and subclinical CME when compared with healthy dogs. Results showed that in CME there is a state of oxidative stress with significant changes in markers of antioxidant defence and in concentrations of free radicals. However, the detection of these changes would depend of the assay used.

Assessment of the antimicrobial, antioxidant and cytotoxic activities of the wild edible mushroom Agaricus lanipes (F.H. Møller & Jul. Schäff.) Hlaváček

The present investigation was undertaken to evaluate the antimicrobial and antioxidant activities of the wild edible mushroom Agaricus lanipes, and also to investigate its cytotoxicity and potential and possible apoptotic effect against the A549 lung cancer cell line in in vitro conditions. Total antioxidant capacity, total phenolic content, total oxidant status, total antioxidant status, lipid hydroperoxides, and total free -SH levels of A. lanipes were found to be 4.55 mg T/g, 14.6 mg GA equivalent/g, 3.10 mg H2O2 equivalent/g, 2.25 mg H2O2 equivalent/g, and 1.90 µmol/g, respectively. The methanolic extract of A. lanipes had relatively strong antimicrobial activity against seven tested microorganism strains. It also had high anti-proliferative potency and strong pro-apoptotic effects, and this mushroom used as a daily nutrient could be a source for new drug developments and treatment in cancer therapies, and could be a guide for studies in this area.

Evaluation of Serum S100A8/S100A9 Levels in Patients with Autoimmune Thyroid Diseases

BACKGROUND

The correlation of S100A8/S100A9 with various inflammatory conditions, including autoimmune diseases have been reported. There is no study investigating the levels of S100A8/S100A9 in autoimmune thyroid diseases (AITD).

AIMS

We aimed to evaluate the level of serum S100A8/S100A9 in AITD.

STUDY DESIGN

Case control study.

METHODS

Fifty patients with AITD (25 Hashimoto's thyroiditis (HT) and 25 Graves' disease (GD)) were included in the study. Twenty seven healthy subjects participated as a control group. Blood samples were obtained in the 3 months after the initiation of medical treatment. Serum levels of total antioxidant status (TAS), total oxidative status (TOS), total free sulfhydryl (SH), lipid hydroperoxide (LOOH) and S100A8/S100A9 were analyzed.

RESULTS

The patients with AITD had significantly higher S100A8/S100A9, OSI, LOOH and TOS levels than the healthy control group. There was no significant difference between GD and HT patients in terms of S100A8/S100A9, TOS and OSI levels. S100A8/S100A9 level was positively correlated with LOOH, TOS and OSI levels but negatively correlated with -SH level in the patients with AITD.

CONCLUSION

Serum S100A8/S100A9 levels were increased in patients with AITD and positively correlated with LOOH, TOS and OSI whereas negatively correlated with SH.

Ganoderma lucidum total triterpenes prevent γ-radiation induced oxidative stress in Swiss albino mice in vivo

OBJECTIVES

The in vivo radio-protective effect of total triterpenes isolated from Ganoderma lucidum (Fr.) P. Karst was evaluated using Swiss albino mice, by pre-treatment with total triterpenes for 14 days, followed by a whole body exposure to γ-radiation.

METHODS

The activities of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), and the level of reduced glutathione (GSH) were analysed in liver and brain homogenates. The extent of lipid and protein peroxidation was also estimated in liver and brain homogenates after irradiation. Protection of radiation-induced DNA strand breaks in peripheral blood lymphocytes and bone marrow cells was assessed using the comet assay.

RESULTS

Total triterpenes were highly effective in reducing the levels of lipid peroxidation and protein oxidation to near normal values in both liver and brain tissues. Total triterpenes, when administered in vivo, were also found to be successful in restoring the antioxidant enzyme activities and GSH level in liver and brain of irradiated mice. Administration of total triterpenes, prior to radiation exposure, significantly decreased the DNA strand breaks.

DISCUSSION

The results of the present study thus revealed the potential therapeutic use of Ganoderma total triterpenes as an adjuvant in radiation therapy.

Paraoxonase and arylesterase levels in autoimmune thyroid diseases

OBJECTIVE

The aim of this study was to evaluate serum paraoxonase-1 (PON1) activity and its association with oxidative stress in autoimmune thyroid disease (AITD).

METHODS

A total of 50 patients with AITD, including 25 with Hashimoto's thyroiditis and 25 with Graves' disease were enrolled. The control group comprised 27 healthy subjects. Blood samples were obtained in the euthyroid period and 3 months after initiation of medical treatment. Serum samples from patients with AITD and the healthy control group were analyzed for basal PON1, salt-stimulated PON1, and arylesterase (ARE) activities, along with lipid hydroperoxide (LOOH) and total free sulfhydryl (-SH) levels.

RESULTS

Serum PON1 activities and -SH levels were significantly lower (P < 0.001, for each), whereas LOOH levels were significantly higher (P < 0.001, for each) in patients with AITD, compared to the control group. We observed no significant differences in ARE levels between the patient and healthy control groups (P > 0.05). PON1 activity was positively correlated with -SH (r = 0.522, P < 0.001) and negatively correlated with LOOH (r = -0.487, P < 0.001). PON1 phenotype distribution of the subjects was not significantly different among the three groups (P = 0.961).

CONCLUSIONS

Serum PON1 activity is decreased in patients with AITD, and correlated positively with -SH, a well-known antioxidant, and negatively with LOOH, an index of lipid oxidation.

Serum calprotectin: a new potential biomarker for thyroid papillary carcinoma

The aim of this study was to evaluate serum calprotectin levels and oxidative stress status in patients with papillary thyroid carcinoma (PTC) and the changes in their levels after total thyroidectomy. The study involved 30 patients with PTC and 30 healthy controls. Blood samples were obtained from the PTC patients before and 1 month after the operation. Preoperative and postoperative serum samples from PTC patients and healthy controls were analysed for calprotectin, total antioxidant status (TAS), total oxidant status (TOS) and lipid hydroperokside (LOOH). The preoperative calprotectin, TOS, OSI and LOOH levels of the patients with PTC were significantly higher compared to those of the control group (p < 0.001, for each). The levels of calprotectin decreased significantly in patients with PTC after the operation (p < 0.001), while TAS, TOS and OSI levels remained unchanged (p = 0.313, p = 0.085 and p = 0.163, respectively). Preoperative serum calprotectin levels were positively correlated with TOS, OSI and LOOH levels and negatively correlated with TAS levels in patients with PTC. In conclusion, serum calprotectin levels is increased in patients with PTC, and calprotectin is positively correlated with TOS and LOOH. Serum calprotectin levels is significantly decreased after total thyroidectomy.

Acute application of antioxidants protects against hyperoxia-induced reduction of plasma nitrite concentration

We investigated the effects of acute intake of antioxidants on hyperoxia-induced oxidative stress, reduction of plasma nitrite and change in arterial stiffness. Twelve healthy males randomly consumed either placebo or an oral antioxidant cocktail (vitamin C, 1000 mg; vitamin E, 600 IU; alpha-lipoic acid, 600 mg). Every therapy was consumed once, a week apart, in a cross-over design, 30 min before the experiment. The volunteers breathed 100% normobaric oxygen between 30th and 60th min of 1-h study protocol. Plasma levels of nitrite, lipid peroxides (LOOH) and vitamin C, arterial stiffness (indicated by augmentation index, AIx) and arterial oxygen (Ptc O2 ) pressure were measured before and after hyperoxia. Exposure to oxygen caused a similar increase of Ptc O2 in both placebo and antioxidants groups, confirming comparable exposure to hyperoxia (438 ± 100 versus 455 ± 83 mm Hg). Vitamin C was increased in the antioxidants group confirming successful application of antioxidants (69 ± 14 versus 57 ± 15 μm). Hyperoxia resulted in increased AIx and LOOH and decreased nitrite in placebo (-32 ± 11 versus -47 ± 13%, 72 ± 7 versus 62 ± 6 μm H2 O2 and 758 ± 184 versus 920 ± 191 nm, respectively), but not in the antioxidants group (-42 ± 13 versus -50 ± 13%, 64 ± 9 versus 61 ± 8 μm H2 O2 and 847 ± 156 versus 936 ± 201 nm, respectively). The acute intake of selected antioxidants was effective in preserving bioavailabity of ˙NO and vascular function, against hyperoxia-induced oxidative stress.

Paraoxonase (PON1) activity in patients with subclinical thoracic aortic atherosclerosis

High density lipoprotein (HDL), a powerful antioxidant, protects low density lipoprotein (LDL) particles against oxidative stress. By limiting LDL oxidation, HDL plays an important role in preventing atherosclerosis (AS). The antioxidant effect of HDL is mostly associated with the paraoxonase (PON1) activity. It has been known that increased aortic intima-media thickness (IMT) is an earlier marker AS than carotid IMT. We aimed to investigate the association between thoracic aortic IMT and serum PON1 activity. We studied 133 patients (mean age: 46.3 ± 8 years) who underwent transesophageal echocardiography (TEE) for various indications. The measurements of thoracic aortic IMT by TEE are classified into four grades (1, 2, 3 and 4). Serum PON1 activity was measured spectrophotometrically. Oxidative and anti-oxidative status was evaluated by measuring serum lipid hydroperoxide (LOOH), total anti-oxidant status (TAS). Serum PON1 activity was progressively decreasing from grade 1 IMT to grade 4 IMT (p < 0.001). However, serum LOOH was significantly lower and TAS was significantly higher in patients with grade 1 when compared with other grades. In multiple linear regression analysis, IMT was independently correlated with PON1 activity (β = -0.495, p < 0.001), TAS level (β = -196, p < 0.009), age (β = 0.145, p = 0.029) and LDL cholesterol level (β = 0.169, p = 0.009). Decreased PON1 activity was independently associated with the extent of thoracic AS. PON1 activity may play a role in pathogenesis of thoracic AS besides age, TAS and LDL cholesterol levels.

Involvement of IGF-II receptors in the antioxidant and neuroprotective effects of IGF-II on adult cortical neuronal cultures

Insulin-like growth factor-II (IGF-II) is a naturally occurring peptide that exerts known pleiotropic effects ranging from metabolic modulation to cellular development, growth and survival. IGF-II triggers its actions by binding to and activating IGF (IGF-I and IGF-II) receptors. In this study, we assessed the neuroprotective effect of IGF-II on corticosterone-induced oxidative damage in adult cortical neuronal cultures and the role of IGF-II receptors in this effect. We provide evidence that treatment with IGF-II alleviates the glucocorticoid-induced toxicity to neuronal cultures, and this neuroprotective effect occurred due to a decrease in reactive oxygen species (ROS) production and a return of the antioxidant status to normal levels. IGF-II acts via not only the regulation of synthesis and/or activity of antioxidant enzymes, especially manganese superoxide dismutase, but also the restoration of mitochondrial cytochrome c oxidase activity and mitochondrial membrane potential. Although the antioxidant effect of IGF-I receptor activation has been widely reported, the involvement of the IGF-II receptor in these processes has not been clearly defined. The present report is the first evidence describing the involvement of IGF-II receptors in redox homeostasis. IGF-II may therefore contribute to the mechanisms of neuroprotection by acting as an antioxidant, reducing the neurodegeneration induced by oxidative insults. These results open the field to new pharmacological approaches to the treatment of diseases involving imbalanced redox homeostasis. In this study, we demonstrated that the antioxidant effect of IGF-II is at least partially mediated by IGF-II receptors.

Acute coronary syndrome remodels the protein cargo and functions of high-density lipoprotein subfractions

OBJECTIVES

This study examined alterations in the functions and proteome of high-density lipoprotein (HDL) subfractions (HDL2 and HDL3) isolated from patients with acute coronary syndrome (ACS) compared with control subjects.

METHODS

We measured HDL subfraction cholesterol efflux capacity, inflammatory index (HII), paraoxonase-1 (PON1) activity, and lipid hydroperoxide (LOOH) levels in both male age-matched controls and the ACS group (n = 40/group). Additionally, proteomic analysis was used to monitor changes in the HDL subfraction proteome between controls and ACS subjects.

RESULTS

Both HDL2 and HDL3 from ACS patients had greater HII and LOOH levels compared with controls (P<0.001); PON1 activity and cholesterol efflux capacity in both HDL2 and HDL3 from the ACS group were significantly less than those of controls (P<0.001). Using proteomic analysis, we demonstrated that, compared with the control group, nine proteins were selectively enriched in HDL3 from subjects with ACS, and ras-related protein Rab-7b was decreased in HDL3. Additionally, in the ACS subjects, 12 proteins were decreased in HDL2 and 4 proteins were increased in HDL2.

CONCLUSIONS

Functional HDL subfractions shifted to dysfunctional HDL subfractions during ACS, and the functional impairment was linked to remodeled protein cargo in HDL subfractions from ACS patients.