Fish oil supplementation counteracts the effect of high-fat and high-sucrose diets on the carbonylated proteome in the rat cerebral cortex.

High daily intake of saturated fats and refined carbohydrates, which often leads to obesity and overweight, has been associated with cognitive impairment, premature brain aging and the aggravation of neurodegenerative diseases. Although the molecular pathology of obesity-related brain damage is not fully understood, the increased levels of oxidative stress induced by the diet seem to be definitively involved. Being protein carbonylation determinant for protein activity and function and a main consequence of oxidative stress, this study aims to investigate the effect of the long-term high-fat and sucrose diet intake on carbonylated proteome of the cerebral cortex of Sprague-Dawley rats. To achieve this goal, the study identified and quantified the carbonylated proteins and lipid peroxidation products in the cortex, and correlated them with biometrical, biochemical and other redox status parameters. Results demonstrated that the obesogenic diet selectively increased oxidative damage of specific proteins that participate in fundamental pathways for brain function, i.e. energy production, glucose metabolism and neurotransmission. This study also evaluated the antioxidant properties of fish oil to counteract diet-induced brain oxidative damage. Fish oil supplementation demonstrated a stronger capacity to modulate carbonylated proteome in the brain cortex. Data indicated that fish oils did not just decrease carbonylation of proteins affected by the obesogenic diet, but also decreased the oxidative damage of other proteins participating in the same metabolic functions, reinforcing the beneficial effect of the supplement on those pathways. The results could help contribute to the development of successful nutritional-based interventions to prevent cognitive decline and promote brain health.

Oxidative damage in the Vesper mouse (Calomys laucha) exposed to a simulated oil spill-a multi-organ study.

Small wild mammals have been used to measure the damage caused by exposure to oil-contaminated soil, including deer mice. However, the study of toxic effects of crude oil using oxidative damage biomarkers in the wild rodent Calomys laucha (Vesper mouse) is absent. This investigation aimed to evaluate the effects of acute exposure to contaminated soil with different concentrations of crude oil (0, 1, 2, 4 and 8% w/w), simulating an accidental spill, using oxidative stress biomarkers in the liver, kidneys, lungs, testes, paw muscle, and lymphocytes of C. laucha. Animals exposed to the contaminated soil showed increases in lipid peroxidation and protein carbonylation at the highest exposure concentrations in most organ homogenates analyzed and also in blood cells, but responses to total antioxidant capacity were tissue-dependent. These results showed that acute exposure to oil-contaminated soil caused oxidative damage in C. laucha and indicate these small mammals may be susceptible to suffer the impacts of such contamination in its occurrence region, threatening the species' survival.

Assessing photoprotective functions of carotenoids in photosynthetic systems of plants and green algae.

Carotenes and xanthophylls act as photoreceptors in the photosystems of plants and algae by absorbing light energy which drives photosynthetic electron transport. Moreover, these carotenoid pigments protect chloroplasts from excess light and from reactive species generated during oxygenic photosynthesis. These pigments share similar spectral properties, a feature which contrasts with the extreme level of conservation of their relative composition and abundance in leaves across taxa. Such a conservation through evolution suggested each carotenoid species had a peculiar role, which indeed has been investigated by different approaches. These studies included the purification of individual carotenoid-binding proteins and their characterization in vitro. In a complementary approach, plant and algal mutants devoid of selected carotenoid species have been produced. The physiological characterization of these mutants revealed that the integrated contributions of all carotenoid species provide the most efficient response to photooxidative stress. In this chapter, we provide step-by-step guides for characterizing the in vivo antioxidant activity of carotenoids in plants and green algae, and methods for quantifying the effect of photooxidative stress in genotypes with altered carotenoid composition or impaired defense mechanisms.

Effects of a Fish Oil Rich in Docosahexaenoic Acid on Cardiometabolic Risk Factors and Oxidative Stress in Healthy Rats.

Omega-3 polyunsaturated fatty acids are associated with a lower risk of cardiometabolic diseases. However, docosahexaenoic acid (DHA) is easily oxidized, leading to cellular damage. The present study examined the effects of an increased concentration of DHA in fish oil (80% of total fatty acids) on cardiometabolic risk factors and oxidative stress compared to coconut oil, soybean oil, and fish oil containing eicosapentaenoic acid (EPA) and DHA in a balanced ratio. Forty healthy male Sprague-Dawley rats were supplemented with corresponding oil for 10 weeks. Supplementation with the fish oil containing 80% DHA decreased plasma fat, plasma total cholesterol and muscle fat compared to the coconut oil and the soybean oil. Increasing concentrations of DHA induced incorporation of DHA and EPA in cell membranes and tissues along with a decrease in ω-6 arachidonic acid. The increase in DHA promoted lipid peroxidation, protein carbonylation and antioxidant response. Taken together, the increased concentration of DHA in fish oil reduced fat accumulation compared to the coconut oil and the soybean oil. This benefit was accompanied by high lipid peroxidation and subsequent protein carbonylation in plasma and in liver. In our healthy framework, the slightly higher carbonylation found after receiving fish oil containing 80% DHA might be a protecting mechanism, which fit with the general improvement of antioxidant defense observed in those rats.

Dose dependent differential effects of toxic metal cadmium in tomato roots: Role of endogenous hydrogen sulfide.

In this study, hydroponic experiments were conducted to elucidate mechanism(s) that are associated with differential effects of low (5 µM) and high (25 µM) dose of cadmium (Cd) stress in tomato. Furthermore, emphasis has also been focused on any involvement of endogenous hydrogen sulfide (H2S) in differential behaviour of low and high doses of Cd stress. At low dose of Cd, root growth i.e. root fresh weight, length and fitness did not significantly alter when compared to the control seedlings. Though at low dose of Cd, cellular accumulation of Cd was slightly increased but this was accompanied by higher endogenous H2S and phytochelatins, L-cysteine desulfhydrase (DES) activity, activities of glutathione biosynthetic and AsA-GSH cycle enzymes, and maintained redox status of ascorbate and glutathione. However, addition of hypotaurine (HT, a scavenger of H2S) resulted in greater toxicity, even at low dose of Cd, and these responses resembled with higher dose of Cd stress such as greater decline in root growth, endogenous H2S and phytochelatins, activities of DES, glutathione biosynthesis and AsA-GSH cycle enzymes, disturbed redox status of ascorbate and glutathione which collectively led to higher oxidative stress in tomato roots. Moreover, addition of HT with higher dose of Cd also further enhanced its toxicity. Collectively, the results showed that differential behaviour of low and high dose of Cd stress is mediated by differential regulation of biochemical attributes in which endogenous H2S has a crucial role.

Effects of calcium supplementation on oxidative status and oxidative damage in great tit nestlings inhabiting a metal-polluted area.

Calcium has been proposed to diminish metal toxicity by the modulation of the oxidative stress. This study explores the effects of Ca availability and metal exposure on oxidative stress biomarkers in great tit (Parus major) nestlings. Nests were supplemented with Ca (Ca-supplemented group) or not supplemented (Control group) in a metal-polluted and a background zone in SW Finland. Metal concentrations were analyzed from feces. We analyzed antioxidants (tGSH, GSH:GSSG ratio, CAT, GST, GPx, SOD), protein carbonylation and lipid peroxidation in red cells of nestlings. Ca-supplemented and fast-growing nestlings showed higher CAT activity to cope with reactive oxygen species (ROS) generated during intensive growth and metabolism. SOD and GPx (the latter not statistically significant) were more active in the polluted area, possibly reflecting higher ROS production in nestlings from this zone due to the enhanced metal exposure and smaller size. Antioxidant levels changed over the range of metal concentrations depending on the Ca levels in plasma, suggesting that higher Ca levels stimulate antioxidants and mitigate the impacts of metals. Ca supplementation may improve nestling traits and reproductive output when antioxidants are enhanced in a situation of oxidative challenge. Therefore, Ca should be considered in future studies assessing metal exposure and effects on wild birds.

Modulation of the Liver Protein Carbonylome by the Combined Effect of Marine Omega-3 PUFAs and Grape Polyphenols Supplementation in Rats Fed an Obesogenic High Fat and High Sucrose Diet.

Diet-induced obesity has been linked to metabolic disorders such as cardiovascular diseases andtype 2 diabetes. A factor linking diet to metabolic disorders is oxidative stress, which can damagebiomolecules, especially proteins. The present study was designed to investigate the effect of marineomega-3 polyunsaturated fatty acids (PUFAs) (eicosapentaenoic acid (EPA) and docosahexaenoic acid(DHA)) and their combination with grape seed polyphenols (GSE) on carbonyl-modified proteins fromplasma and liver in Wistar Kyoto rats fed an obesogenic diet, namely high-fat and high-sucrose (HFHS)diet. A proteomics approach consisting of fluorescein 5-thiosemicarbazide (FTSC) labelling of proteincarbonyls, visualization of FTSC-labelled protein on 1-DE or 2-DE gels, and protein identification byMS/MS was used for the protein oxidation assessment. Results showed the efficiency of the combinationof both bioactive compounds in decreasing the total protein carbonylation induced by HFHS diet in bothplasma and liver. The analysis of carbonylated protein targets, also referred to as the 'carbonylome',revealed an individual response of liver proteins to supplements and a modulatory effect on specificmetabolic pathways and processes due to, at least in part, the control exerted by the supplements on theliver protein carbonylome. This investigation highlights the additive effect of dietary fish oils and grapeseed polyphenols in modulating in vivo oxidative damage of proteins induced by the consumption ofHFHS diets.

Effects of selenium on oxidative damage and antioxidant enzymes of eukaryotic cells: wine Saccharomyces cerevisiae.

AIM: To clarify the effects of selenium (Se), parameters related to oxidative issues, as well as the antioxidant response were investigated on an autochthonous wine yeast strain. METHODS AND RESULTS: Antioxidant enzyme activity, gel electrophoresis, Western blot and MDA level were used to investigate the effects of different concentration of Se in wine yeast. We found that Se is able to affect the enzymatic activities of catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD). An increase in lipid peroxidation was observed in a dose-dependent manner of (Se), thus, indicating the occurrence of cell membrane damage. Additionally, Se induced post-translational oxidative modifications of proteins, especially oxidation of thiol groups (both reversible and irreversible) and protein carbonylation (irreversible oxidation). CONCLUSION: These results obtained could further the understanding the effect of different concentration of Se in wine yeast strain with which Se affect the enzymatic activities and induces some post-translational modifications of proteins. SIGNIFICANCE AND IMPACT OF THE STUDY: The understanding of mechanisms regulating the response of wine yeast to Se is important for future work using selenized yeast as enriched Se supplements in human nutrition.

Data on how several physiological parameters of stored red blood cells are similar in glucose 6-phosphate dehydrogenase deficient and sufficient donors.

This article contains data on the variation in several physiological parameters of red blood cells (RBCs) donated by eligible glucose-6-phosphate dehydrogenase (G6PD) deficient donors during storage in standard blood bank conditions compared to control, G6PD sufficient (G6PD(+)) cells. Intracellular reactive oxygen species (ROS) generation, cell fragility and membrane exovesiculation were measured in RBCs throughout the storage period, with or without stimulation by oxidants, supplementation of N-acetylcysteine and energy depletion, following incubation of stored cells for 24 h at 37 °C. Apart from cell characteristics, the total or uric acid-dependent antioxidant capacity of the supernatant in addition to extracellular potassium concentration was determined in RBC units. Finally, procoagulant activity and protein carbonylation levels were measured in the microparticles population. Further information can be found in "Glucose 6-phosphate dehydrogenase deficient subjects may be better "storers" than donors of red blood cells" [1].

Pomegranate seed oil nanoemulsions with selective antiglioma activity: optimization and evaluation of cytotoxicity, genotoxicity and oxidative effects on mononuclear cells.

CONTEXT: Glioma is a malignant brain tumor with rapid proliferation, infiltrative growth, poor prognosis and it is chemoresistent. Pomegranate seed oil (PSO) has antioxidant, anti-inflammatory and antitumor properties. This study showed the optimization of PSO nanoemulsions (NEs) as an alternative for glioma treatment. OBJECTIVE: The study aimed to evaluate PSO NEs cytotoxicity on human blood cells and antiglioma effects against C6 cells. MATERIALS AND METHODS: NEs were prepared by the spontaneous emulsification method, using PSO at 1.5 and 3.0%, and were evaluated regarding their physical stability and antioxidant activity. Toxicity evaluations in human blood cells were performed in terms of cell viability, genotoxicity, lipid peroxidation, protein carbonylation, catalase activity and hemolysis at 0.1, 0.25 and 0.5 mg/mL PSO, after a 72-h incubation period. In vitro antitumor effect was determined against glioma cells after 24 and 48 h, and astrocytes were used as a non-transformed cell model. RESULTS: Formulations presented droplet size below 250 nm, low polydispersity index, negative zeta potential and pH in the acid range. NEs and PSO had scavenging capacity around 30% and promoted a proliferative effect in mononuclear cells, increasing about 50% cell viability. No genotoxic and oxidative damage was observed in lipid peroxidation, protein carbonylation and catalase activity evaluations for NEs. Hemolysis study showed a hemolytic effect at high concentrations. Moreover, formulations reduced only tumor cell viability to 47%, approximately. DISCUSSION AND CONCLUSION: Formulations are adequate and safe for intravenous administration. Besides, in vitro antitumor activity indicates that NEs are promising for glioma treatment.

Effect of N-acetylcysteine administration on homocysteine level, oxidative damage to proteins, and levels of iron (Fe) and Fe-related proteins in lead-exposed workers.

N-Acetylcysteine (NAC) could be included in protocols designed for the treatment of lead toxicity. Therefore, in this study, we decided to investigate the influence of NAC administration on homocysteine (Hcy) levels, oxidative damage to proteins, and the levels of iron (Fe), transferrin (TRF), and haptoglobin (HPG) in lead (Pb)-exposed workers. The examined population (n = 171) was composed of male employees who worked with Pb. They were randomized into four groups. Workers who were not administered any antioxidants, drugs, vitamins, or dietary supplements were classified as the reference group (n = 49). The remaining three groups consisted of workers who were treated orally with NAC at three different doses (1 × 200, 2 × 200, or 2 × 400 mg) for 12 weeks. After the treatment, blood Pb levels significantly decreased in the groups receiving NAC compared with the reference group. The protein concentration was not affected by NAC administration. In contrast, Hcy levels significantly decreased or showed a strong tendency toward lower values depending on the NAC dose. Levels of the protein carbonyl groups were significantly decreased in all of the groups receiving NAC. Conversely, glutamate dehydrogenase activity was significantly elevated in all of the groups receiving NAC, while the level of protein thiol groups was significantly elevated only in the group receiving 200 mg of NAC. Treatment with NAC did not significantly affect Fe and TRF levels, whereas HPG levels showed a tendency toward lower values. Treatment with NAC normalized the level of Hcy and decreased oxidative stress as measured by the protein carbonyl content; this effect occurred in a dose-dependent manner. Moreover, small doses of NAC elevated the levels of protein thiol groups. Therefore, NAC could be introduced as an alternative therapy for chronic Pb toxicity in humans.

Fatty acids binding to human serum albumin: Changes of reactivity and glycation level of Cysteine-34 free thiol group with methylglyoxal.

Fatty acids (FAs) binding to human serum albumin (HSA) could lead to the changes of Cys-34 thiol group accessibility and reactivity, i.e. its scavenger capacity and antioxidant property. The influence of saturated, mono and poly unsaturated, and fish oil FAs binding to HSA on the carbonylation level and the reactivity of HSA-SH and HSA modified with methylglyoxal (MG-HSA-SH) was investigated. Changes of thiol group reactivity were followed by determination of pseudo first order rate constant (k') for thiols reaction with 5,5'-dithiobis(2-nitrobenzoic acid). HSA changes were monitored using native PAG electrophoresis and fluorescence spectroscopy. For FA/HSA molar ratios screening, qTLC and GC were used. FAs increase thiol group carbonylation levels from 8% to 20%. The k' values obtained for FAs-free HSA-SH and FAs-free MG-HSA-SH are almost equal (7.5×10(-3) and 7.7×10(-3)s(-1), resp.). Binding of all FAs amplify the reactivity (k' values from 14.6×10(-3) to 26.0×10(-3)s(-1)) of HSA-SH group for 2-3.5times in the order: palmitic, docosahexaenoic, fish oil extract, stearic, oleic, myristic and eicosapentaenoic acid, due to HSA conformational changes. FAs-bound MG-HSA-SH samples follow that pattern, but their k' values (from 9.8×10(-3) to 14.3×10(-3)s(-1)) were lower compared to unmodified HSA due to additional conformation changes of HSA molecules during carbonylation. Carbonylation level and reactivity of Cys34 thiol group of unmodified and carbonylated HSA depend on type of FAs bound to HSA, which implies the possibility for modulation of -SH reactivity (scavenger capacity and antioxidant property) by FAs as a supplement.

THE COMBINATION OF α-LIPOIC ACID INTAKE WITH ECCENTRIC EXERCISE MODULATES ERYTHROPOIETIN RELEASE.

The generation of reactive nitrogen/oxygen species (RN/OS) represents an important mechanism in erythropoietin (EPO) expression and skeletal muscle adaptation to physical and metabolic stress. RN/OS generation can be modulated by intense exercise and nutrition supplements such as α-lipoic acid, which demonstrates both anti- and pro-oxidative action. The study was designed to show the changes in the haematological response through the combination of α-lipoic acid intake with running eccentric exercise. Sixteen healthy young males participated in the randomised and placebo-controlled study. The exercise trial involved a 90-min run followed by a 15-min eccentric phase at 65% VO2max (-10% gradient). It significantly increased serum concentrations of nitric oxide (NO), hydrogen peroxide (H2O2) and pro-oxidative products such as 8-isoprostanes (8-iso), lipid peroxides (LPO) and protein carbonyls (PC). α-Lipoic acid intake (Thiogamma: 1200 mg daily for 10 days prior to exercise) resulted in a 2-fold elevation of serum H2O2 concentration before exercise, but it prevented the generation of NO, 8-iso, LPO and PC at 20 min, 24 h, and 48 h after exercise. α-Lipoic acid also elevated serum EPO level, which highly correlated with NO/H2O2 ratio (r = 0.718, P < 0.01). Serum total creatine kinase (CK) activity, as a marker of muscle damage, reached a peak at 24 h after exercise (placebo 732 ± 207 IU · L(-1), α-lipoic acid 481 ± 103 IU · L(-1)), and correlated with EPO (r = 0.478, P < 0.01) in the α-lipoic acid group. In conclusion, the intake of high α-lipoic acid modulates RN/OS generation, enhances EPO release and reduces muscle damage after running eccentric exercise.

Targets of protein carbonylation in spontaneously hypertensive obese Koletsky rats and healthy Wistar counterparts: a potential role on metabolic disorders.

The study innovatively pinpoints target proteins of carbonylation, a key PTM induced by oxidative stress, in the SHROB (genetically obese spontaneously hypertensive) rat model of metabolic syndrome (MetS). Protein carbonylation was assessed by a fluorescence-labeling proteomics approach, and complemented with biometric and biochemical markers of MetS. SHROB and healthy Wistar rats were fed two diets, soybean and linseed oil supplementations, in order to distinguish intrinsic carbonylation of SHROB animals from diet-modulated carbonylation unrelated to MetS. First exploratory data showed similar carbonylation patterns and metabolic conditions in SHROB rats fed soybean and linseed, but different from Wistar animals. A total of 18 carbonylated spots in liver, and 12 in skeletal tissue, related to pathways of lipid (29.6%), carbohydrate (25.9%) and amino acid (18.5%) metabolisms, were identified. In particular, SHROB animals present higher carbonylation in four liver proteins belonging to lipid metabolism, redox regulation and chaperone activity (ALDH2, PDI, PDIA3, PECR), and in the skeletal muscle ALDOA that is involved in muscle dysfunction. Conversely, SHROB rats display lower carbonylation in liver albumin, AKR1C9, ADH1 and catalase. This investigation provides a novel perspective of carbonylation in the context of metabolic disorders, and may be a starting point to characterize new redox pathways exacerbating MetS. BIOLOGICAL SIGNIFICANCE: Oxidative stress is a concomitant factor in the pathogenesis of MetS that induces oxidative PTM as carbonylation. Through the use of a redox proteomics approach, we have thoroughly mapped the occurrence of protein targets of carbonylation in the genetically-induced MetS model SHROB rat. The present research brings a new insight of MetS pathogenesis and it may provide valuable information to understand the biological impact of oxidative stress in patients with MetS.

Effect of single dose administration of methylsulfonylmethane on oxidative stress following acute exhaustive exercise.

Methylsulfonylmethane (MSM) is a sulfur-containing compound commonly found in diet and known to reduce oxidative stress. This trial was conducted to determine whether single dose supplementation with MSM attenuates post-exercise oxidative stress in healthy untrained young men. Sixteen untrained men volunteered for this study. Participants were randomized in a double-blind placebo-controlled fashion into 2 groups: Methylsulfonylmethane (MSM) (n = 8) and placebo (n = 8). The participants took supplementation or placebo before running on treadmill for 45 min at 75% VO2max. The MSM supplementation was prepared in water as 100 mg/ kg body weight. The placebo group received water. Serum Malondealdehyde (MDA), uric acid, bilirubin, protein carbonyl (PC) and plasma vitamin E levels were determined as the markers of oxidative stress. Plasma GSH (reduced Glutathione) and total antioxidant capacity (TAC) were measured as markers of plasma antioxidant system. MSM supplementation successfully lowered serum PC 2 and 24 h after exercise. Plasma TAC in MSM group was higher at 24 h after exercise. Serum level of uric acid and bilirubin were significantly low immediately after exercise in MSM supplemented group. There was no significant difference between groups in terms of plasma GSH level. These results complement earlier studies showing anti-oxidant effect of MSM and suggest that single dose oral supplementation with MSM lowers exercise induced oxidative stress in healthy untrained young men, but is not adequate to significantly affect plasma GSH level.

Relationships among Oxidative Stress Markers, Life Style Factors and Biochemical Findings / 대한진단검사의학회지

BACKGROUND: In many studies, oxidative stress markers have been employed to serve as a measure of a disease process or to reflect oxidative status. These oxidative stress markers must have some degree of predictive validity, but full substantiation of this relation is still lacking. This paper presents data on levels of three biomarkers, oxidized low-density lipoproteins (LDL), carbonyl, and 8-hydroxy-2'-deoxyguanosine (8-OHdG), and a number of life style factors associated with oxidative stress in healthy adults. METHODS: For 237 healthy adults aged 40-60 years, a number of life style factors, biochemical characteristics and oxidative status were evaluated. Markers of oxidative stress were measured by an ELISA method. RESULTS: Waist-hip ratio and use of vitamin supplement were associated with serum oxidized LDL (P<0.05). Body mass index and stress had a relationship (P<0.05) with protein carbonyl. Creactive protein was related to serum oxidized LDL (P<0.01). There was no correlation among three oxidative stress markers, oxidized LDL, carbonyl, and 8-OHdG. CONCLUSIONS: The oxidative stress markers used in this study could not be regarded as a general estimate of the healthy individual oxidative status. Further studies focusing on the development of biomarkers to reflect changes in the oxidative status under normal, non-pathological conditions in humans will be required.