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Sample records for production oxidative damage

  1. Superoxide and the production of oxidative DNA damage.

    PubMed Central

    Keyer, K; Gort, A S; Imlay, J A

    1995-01-01

    The conventional model of oxidative DNA damage posits a role for superoxide (O2-) as a reductant for iron, which subsequently generates a hydroxyl radical by transferring the electron to H2O2. The hydroxyl radical then attacks DNA. Indeed, mutants of Escherichia coli that lack superoxide dismutase (SOD) were 10-fold more vulnerable to DNA oxidation by H2O2 than were wild-type cells. Even the pace of DNA damage by endogenous oxidants was great enough that the SOD mutants could not tolerate air if enzymes that repair oxidative DNA lesions were inactive. However, DNA oxidation proceeds in SOD-proficient cells without the involvement of O2-, as evidenced by the failure of SOD overproduction or anaerobiosis to suppress damage by H2O2. Furthermore, the mechanism by which excess O2- causes damage was called into question when the hypersensitivity of SOD mutants to DNA damage persisted for at least 20 min after O2- had been dispelled through the imposition of anaerobiosis. That behavior contradicted the standard model, which requires that O2- be present to rereduce cellular iron during the period of exposure to H2O2. Evidently, DNA oxidation is driven by a reductant other than O2-, which leaves the mechanism of damage promotion by O2- unsettled. One possibility is that, through its well-established ability to leach iron from iron-sulfur clusters, O2- increases the amount of free iron that is available to catalyze hydroxyl radical production. Experiments with iron transport mutants confirmed that increases in free-iron concentration have the effect of accelerating DNA oxidation. Thus, O2- may be genotoxic only in doses that exceed those found in SOD-proficient cells, and in those limited circumstances it may promote DNA damage by increasing the amount of DNA-bound iron. PMID:7592468

  2. Bee Products Prevent Agrichemical-Induced Oxidative Damage in Fish

    PubMed Central

    Ferreira, Daiane; Rocha, Helio Carlos; Kreutz, Luiz Carlos; Loro, Vania Lucia; Marqueze, Alessandra; Koakoski, Gessi; Santos da Rosa, João Gabriel; Gusso, Darlan; Oliveira, Thiago Acosta; de Abreu, Murilo Sander; Barcellos, Leonardo José Gil

    2013-01-01

    In southern South America and other parts of the world, aquaculture is an activity that complements agriculture. Small amounts of agrichemicals can reach aquaculture ponds, which results in numerous problems caused by oxidative stress in non-target organisms. Substances that can prevent or reverse agrichemical-induced oxidative damage may be used to combat these effects. This study includes four experiments. In each experiment, 96 mixed-sex, 6-month-old Rhamdia quelen (118±15 g) were distributed into eight experimental groups: a control group that was not exposed to contaminated water, three groups that were exposed to various concentrations of bee products, three groups that were exposed to various concentrations of bee products plus tebuconazole (TEB; Folicur 200 CE™) and a group that was exposed to 0.88 mg L−1 of TEB alone (corresponding to 16.6% of the 96-h LC50). We show that waterborne bee products, including royal jelly (RJ), honey (H), bee pollen (BP) and propolis (P), reversed the oxidative damage caused by exposure to TEB. These effects were likely caused by the high polyphenol contents of these bee-derived compounds. The most likely mechanism of action for the protective effects of bee products against tissue oxidation and the resultant damage is that the enzymatic activities of superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST) are increased. PMID:24098336

  3. Bee products prevent agrichemical-induced oxidative damage in fish.

    PubMed

    Ferreira, Daiane; Rocha, Helio Carlos; Kreutz, Luiz Carlos; Loro, Vania Lucia; Marqueze, Alessandra; Koakoski, Gessi; da Rosa, João Gabriel Santos; Gusso, Darlan; Oliveira, Thiago Acosta; de Abreu, Murilo Sander; Barcellos, Leonardo José Gil

    2013-01-01

    In southern South America and other parts of the world, aquaculture is an activity that complements agriculture. Small amounts of agrichemicals can reach aquaculture ponds, which results in numerous problems caused by oxidative stress in non-target organisms. Substances that can prevent or reverse agrichemical-induced oxidative damage may be used to combat these effects. This study includes four experiments. In each experiment, 96 mixed-sex, 6-month-old Rhamdia quelen (118±15 g) were distributed into eight experimental groups: a control group that was not exposed to contaminated water, three groups that were exposed to various concentrations of bee products, three groups that were exposed to various concentrations of bee products plus tebuconazole (TEB; Folicur 200 CE™) and a group that was exposed to 0.88 mg L(-1) of TEB alone (corresponding to 16.6% of the 96-h LC50). We show that waterborne bee products, including royal jelly (RJ), honey (H), bee pollen (BP) and propolis (P), reversed the oxidative damage caused by exposure to TEB. These effects were likely caused by the high polyphenol contents of these bee-derived compounds. The most likely mechanism of action for the protective effects of bee products against tissue oxidation and the resultant damage is that the enzymatic activities of superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST) are increased.

  4. Relationship between indium exposure and oxidative damage in workers in indium tin oxide production plants.

    PubMed

    Liu, Hung-Hsin; Chen, Chang-Yun; Chen, Gun-Ing; Lee, Lien-Hsiung; Chen, Hsiu-Ling

    2012-05-01

    The study aimed to assess the relationship between indium exposure and surfactant protein and any oxidative damage in indium tin oxide (ITO)-exposed workers. The study was conducted in two typical ITO-manufacturing plants in Taiwan. One hundred and seventy manufacturing workers and 132 administrators were recruited. The geometric mean serum indium (S-In) level in the workers of the manufacturing department was 1.26 μg/l, which was significantly higher than those in the administrative department (0.72 μg/l). The S-In levels of 49 workers were higher than 3 μg/l (49/302, 16.2%), exceeding an occupational exposure limit suggested by the Japan Society for Occupational Health. Significant positive relationships were found between S-In and surfactant protein A (SP-A), and surfactant protein D (SP-D) levels. SP-A and SP-D levels were elevated significantly in the workers with moderately high indium exposure. The present study indicates a significant elevating trend of SP-A and SP-D levels in ITO-manufacturing workers, which are sensitive markers of interstitial lung disease. Though the indium exposure is not directly linked to all indicators of oxidative DNA damage, the ITO-manufacturing workplace is suggested to be related to oxidative DNA damage for the workers in the current study. Therefore, in addition to the indium exposure, there might be other occupational hazards in the ITO workplace to cause oxidative damage.

  5. Estimation of oxidative DNA damage in man from urinary excretion of repair products.

    PubMed

    Loft, S; Poulsen, H E

    1998-01-01

    DNA is constantly damaged and repaired in living cells. The repair products of the oxidative DNA lesions, i.e. oxidised nucleosides and bases, are poor substrates for the enzymes involved in nucleotide synthesis, are fairly water soluble, and generally excreted into the urine without further metabolism. Among the possible products, 8-oxo-2'-deoxyguanosine, 8-oxoguanine, thymine glycol, thymidine glycol and, 5-hydroxymethyluracil have so far been identified in urine. It should be emphasised that the excretion of the repair products in urine represents the average rate of damage in the total body whereas the level of oxidised bases in nuclear DNA is a concentration measurement in that specific tissue/cells in the moment of sampling. The rate of oxidative DNA modifications has been studied in humans by means of the repair products as urinary biomarkers, particularly with respect to 8-oxo-2'-deoxyguanosine. The data obtained so far indicate that the important determinants of the oxidative damage rate include tobacco smoking, oxygen consumption and some inflammatory diseases whereas diet composition, energy restriction and antioxidant supplements have but a minimal influence, possibly with the exception of yet unidentified phytochemicals, e.g. from cruciferous vegetables. The data are consistent with the experimentally based notion that oxidative DNA damage is an important mutagenic and apparently carcinogenic factor. However, the proof of a causal relationship in humans is still warranted. In the future the use of biomarkers may provide this evidence and allow further investigations on the qualitative and quantitative importance of oxidative DNA modification and carcinogenesis in man, as well as elucidate possible preventive measures.

  6. Disinfection by-products effect on swimmers oxidative stress and respiratory damage.

    PubMed

    Llana-Belloch, Salvador; Priego Quesada, Jose Ignacio; Pérez-Soriano, Pedro; Lucas-Cuevas, Ángel G; Salvador-Pascual, Andrea; Olaso-González, Gloria; Moliner-Martinez, Yolanda; Verdú-Andres, Jorge; Campins-Falco, Pilar; Gómez-Cabrera, M Carmen

    2016-08-01

    Disinfection by-products (DBPs) are generated through the reaction of chlorine with organic and inorganic matter in indoor swimming pools. Different DBPs are present in indoor swimming pools. This study evaluated the effects of different chlorinated formations in oxidative stress and lung damage in 20 swimmers after 40 min of aerobic swimming in 3 indoor pools with different characteristics. Biological samples were collected to measure lung damage (serum-surfactant-associated proteins A and B), oxidative stress parameters (plasma protein carbonylation and malondialdehyde, and whole-blood glutathione oxidation), and swimming exertion values (blood lactate) before and after exercise. Free chlorine and combined chlorine in water, and chlorine in air samples were determined in all the swimming pools. Chlorination as disinfection treatment led to the formation of chloramines in water samples, mainly mono- and dichloramine. However, free chlorine was the predominate species in ultraviolet-treated swimming pool. Levels of total chlorine increased as a function of the swimming activity in chlorinated swimming pools. The lower quality of the installation resulted in a higher content of total chlorine, especially in air samples, and therefore a higher exposure of the swimmer to DBPs. However, the concentration level of chlorinated DBPs did not result in significant variation in serum-surfactant-associated proteins A and oxidative stress parameters in swimmers. In conclusion, the quality of the installation affected the DBPs concentration; however, it did not lead to lung epithelial damage and oxidative stress parameters in swimmers.

  7. Mass spectrometric quantification of amino acid oxidation products identifies oxidative mechanisms of diabetic end-organ damage

    PubMed Central

    Vivekanadan-Giri, Anuradha; Wang, Jeffrey H.; Byun, Jaeman

    2010-01-01

    Diabetes mellitus is increasingly prevalent worldwide. Diabetic individuals are at markedly increased risk for premature death due to cardiovascular disease. Furthermore, substantial morbidity results from microvascular complications which include retinopathy, nephropathy, and neuropathy. Clinical studies involving diabetic patients have suggested that degree of diabetic hyperglycemia correlates with risk of complications. Recent evidence implicates a central role for oxidative stress and vascular inflammation in all forms of insulin resistance, obesity, diabetes and its complications. Although, glucose promotes glycoxidation reactions in vitro and products of glycoxidation and lipoxidation are elevated in plasma and tissue in diabetics, the exact relationships among hyperglycemia, the diabetic state, and oxidative stress are not well-understood. Using a combination of in vitro and in vivo experiments, we have identified amino acid oxidation markers that serve as molecular fingerprints of specific oxidative pathways. Quantification of these products utilizing highly sensitive and specific gas chromatography/mass spectrometry in animal models of diabetic complications and in humans has provided insights in oxidative pathways that result in diabetic complications. Our studies strongly support the hypothesis that unique oxidants are generated in the microenvironment of tissues vulnerable to diabetic damage. Potential therapies interrupting these reactive pathways in target tissue are likely to be beneficial in preventing diabetic complications. PMID:18752069

  8. Acetaminophen (paracetamol) inhibits myeloperoxidase-catalyzed oxidant production and biological damage at therapeutically achievable concentrations.

    PubMed

    Koelsch, Maud; Mallak, Roger; Graham, Garry G; Kajer, Tracey; Milligan, Marian K; Nguyen, Ly Q; Newsham, Dawn W; Keh, Jeremy S; Kettle, Anthony J; Scott, Kieran F; Ziegler, John B; Pattison, David I; Fu, Shanlin; Hawkins, Clare L; Rees, Martin D; Davies, Michael J

    2010-04-15

    The heme peroxidase enzyme myeloperoxidase (MPO) is released by activated neutrophils and monocytes, where it uses hydrogen peroxide (H(2)O(2)) to catalyze the production of the potent oxidants hypochlorous acid (HOCl), hypobromous acid (HOBr) and hypothiocyanous acid (HOSCN) from halide and pseudohalide (SCN(-)) ions. These oxidants have been implicated as key mediators of tissue damage in many human inflammatory diseases including atherosclerosis, asthma, rheumatoid arthritis, cystic fibrosis and some cancers. It is shown here that acetaminophen (paracetamol), a phenol-based drug with analgesic and antipyretic actions, is an efficient inhibitor of HOCl and HOBr generation by isolated MPO-H(2)O(2)-halide systems. With physiological halide concentrations, acetaminophen concentrations required for 50% inhibition of oxidant formation (IC(50)) were 77+/-6microM (100mMCl(-)) and 92+/-2microM (100mMCl(-) plus 100microMBr(-)), as measured by trapping of oxidants with taurine. The IC(50) for inhibition of HOCl generation by human neutrophils was ca. 100microM. These values are lower than the maximal therapeutic plasma concentrations of acetaminophen (< or =150microM) resulting from typical dosing regimes. Acetaminophen did not diminish superoxide generation by neutrophils, as measured by lucigenin-dependent chemiluminescence. Inhibition of HOCl production was associated with the generation of fluorescent acetaminophen oxidation products, consistent with acetaminophen acting as a competitive substrate of MPO. Inhibition by acetaminophen was maintained in the presence of heparan sulfate and extracellular matrix, materials implicated in the sequestration of MPO at sites of inflammation in vivo. Overall, these data indicate that acetaminophen may be an important modulator of MPO activity in vivo. 2009 Elsevier Inc. All rights reserved.

  9. Long-lived Indy induces reduced mitochondrial reactive oxygen species production and oxidative damage

    PubMed Central

    Neretti, Nicola; Wang, Pei-Yu; Brodsky, Alexander S.; Nyguyen, Hieu H.; White, Kevin P.; Rogina, Blanka; Helfand, Stephen L.

    2009-01-01

    Decreased Indy activity extends lifespan in D. melanogaster without significant reduction in fecundity, metabolic rate, or locomotion. To understand the underlying mechanisms leading to lifespan extension in this mutant strain, we compared the genome-wide gene expression changes in the head and thorax of adult Indy mutant with control flies over the course of their lifespan. A signature enrichment analysis of metabolic and signaling pathways revealed that expression levels of genes in the oxidative phosphorylation pathway are significantly lower in Indy starting at day 20. We confirmed experimentally that complexes I and III of the electron transport chain have lower enzyme activity in Indy long-lived flies by Day 20 and predicted that reactive oxygen species (ROS) production in mitochondria could be reduced. Consistently, we found that both ROS production and protein damage are reduced in Indy with respect to control. However, we did not detect significant differences in total ATP, a phenotype that could be explained by our finding of a higher mitochondrial density in Indy mutants. Thus, one potential mechanism by which Indy mutants extend life span could be through an alteration in mitochondrial physiology leading to an increased efficiency in the ATP/ROS ratio. PMID:19164521

  10. Different mechanisms for the photoinduced production of oxidative DNA damage by fluoroquinolones differing in photostability.

    PubMed

    Spratt, T E; Schultz, S S; Levy, D E; Chen, D; Schlüter, G; Williams, G M

    1999-09-01

    Several fluoroquinolone antibacterial agents exhibit an adverse phototoxic effect in humans and are photo-cocarcinogenic in mice. The UV-induced production of reactive oxygen species plays a role in the toxicity and may be involved in carcinogenicity. Four fluoroquinolones were examined for the ability to photochemically produce oxidative damage in naked DNA. The major structural difference in the fluoroquinolones that would have an effect on their photostability is the functionality at the 8-position. At this position, 1-cyclopropyl-7-(2,8-diazbicyclo[4.3.0]non-8-yl)-6, 8-difluoro-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid (BAY y3118) contains a chlorine atom, lomefloxacin a fluorine atom, ciprofloxacin a proton, and moxifloxacin a methoxy group. The formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) in calf thymus DNA was assessed by HPLC with electrochemical detection, and strand breaks were measured in pBR322 with agarose gel electrophoresis. The relative photolability of the fluoroquinolones correlated to the extent of production of 8-oxodGuo and strand breaks, with both UVA and UVB irradiation, in the following order: BAY y3118 approximately lomefloxacin > ciprofloxacin > moxifloxacin. Experiments were performed to determine whether the mechanism of damage was due to a type I (radical) or type II (singlet oxygen) pathway. Nitrogen depletion of oxygen resulted in a decrease in the extent of formation of 8-oxodGuo, suggesting that oxygen was involved. The use of selective radical or singlet oxygen inhibitors was inconclusive with respect to which pathway was involved. The use of D(2)O as a solvent, which would extend the lifetime of singlet oxygen, suggested that this species is involved in the formation of 8-oxodGuo by moxifloxacin and ciprofloxacin, but not by lomefloxacin and BAY y3118. Similarly, it was found that singlet oxygen was not involved in strand break formation. Thus, the evidence suggests that fluoroquinolones can photochemically

  11. Markers of lipid oxidative damage in the exhaled breath condensate of nano TiO2 production workers.

    PubMed

    Pelclova, Daniela; Zdimal, Vladimir; Kacer, Petr; Zikova, Nadezda; Komarc, Martin; Fenclova, Zdenka; Vlckova, Stepanka; Schwarz, Jaroslav; Makeš, Otakar; Syslova, Kamila; Navratil, Tomas; Turci, Francesco; Corazzari, Ingrid; Zakharov, Sergey; Bello, Dhimiter

    2017-02-01

    Nanoscale titanium dioxide (nanoTiO2) is a commercially important nanomaterial. Animal studies have documented lung injury and inflammation, oxidative stress, cytotoxicity and genotoxicity. Yet, human health data are scarce and quantitative risk assessments and biomonitoring of exposure are lacking. NanoTiO2 is classified by IARC as a group 2B, possible human carcinogen. In our earlier studies we documented an increase in markers of inflammation, as well as DNA and protein oxidative damage, in exhaled breath condensate (EBC) of workers exposed nanoTiO2. This study focuses on biomarkers of lipid oxidation. Several established lipid oxidative markers (malondialdehyde, 4-hydroxy-trans-hexenal, 4-hydroxy-trans-nonenal, 8-isoProstaglandin F2α and aldehydes C6-C12) were studied in EBC and urine of 34 workers and 45 comparable controls. The median particle number concentration in the production line ranged from 1.98 × 10(4) to 2.32 × 10(4) particles/cm(3) with ∼80% of the particles <100 nm in diameter. Mass concentration varied between 0.40 and 0.65 mg/m(3). All 11 markers of lipid oxidation were elevated in production workers relative to the controls (p < 0.001). A significant dose-dependent association was found between exposure to TiO2 and markers of lipid oxidation in the EBC. These markers were not elevated in the urine samples. Lipid oxidation in the EBC of workers exposed to (nano)TiO2 complements our earlier findings on DNA and protein damage. These results are consistent with the oxidative stress hypothesis and suggest lung injury at the molecular level. Further studies should focus on clinical markers of potential disease progression. EBC has reemerged as a sensitive technique for noninvasive monitoring of workers exposed to engineered nanoparticles.

  12. Natural Products Mediated Regulation of Oxidative Stress and DNA Damage in Ultraviolet Exposed Skin Cells.

    PubMed

    Farooqi, Ammad A; Li, Ruei-Nian; Huang, Hurng-Wern; Ismail, Muhammad; Yuan, Shyng-Shiou F; Wang, Hui-Min D; Liu, Jing-Ru; Tang, Jen-Yang; Chang, Hsueh-Wei

    2015-01-01

    Data obtained through high-throughput technologies have gradually revealed that a unique stratified epithelial architecture of human skin along with the antioxidant-response pathways provided vital defensive mechanisms against UV radiation. However, it is noteworthy that skin is a major target for toxic insult by UV radiations that can alter its structure and function. Substantial fraction of information has been added into the existing pool of knowledge related to natural products mediated biological effects in UV exposed skin cells. Accumulating evidence has started to shed light on the potential of these bioactive ingredients as protective natural products in cosmetics against UV photodamage by exerting biological effects mainly through wide ranging intracellular signalling cascades of oxidative stress and modulation of miRNAs. In this review, we have summarized recently emerging scientific evidences addressing underlying mechanisms of UV induced oxidative stress and deregulation of signalling cascades and how natural products can be used tactfully to protect against UV induced harmful effects.

  13. Oxidative damage in dengue fever.

    PubMed

    Seet, Raymond C S; Lee, Chung-Yung J; Lim, Erle C H; Quek, Amy M L; Yeo, Leonard L L; Huang, Shan-Hong; Halliwell, Barry

    2009-08-15

    Oxidative stress may be important in the pathogenesis of dengue infection. Using accurate markers of oxidative damage, we assessed the extent of oxidative damage in dengue patients. The levels of hydroxyeicosatetraenoic acid products (HETEs), F(2)-isoprostanes (F(2)-IsoPs), and cholesterol oxidation products (COPs) were measured in 28 adult dengue patients and 28 age-matched study controls during the febrile, defervescent, and convalescent stages of infection. We compared the absolute and the percentage change in these markers in relation to key clinical parameters and inflammatory markers. The levels of total HETEs and total HETEs/arachidonate, total F(2)-IsoPs/arachidonate, and COPs/cholesterol were higher during the febrile compared to the convalescent level. Total HETEs correlated positively with admission systolic blood pressure (r=0.52, p<0.05), whereas an inverse relationship was found between 7beta-hydroxycholesterol and systolic and diastolic blood pressure (r=-0.61 and -0.59, respectively, p<0.01). The urinary F(2)-IsoP level was higher in urine during the febrile stage compared to the convalescent level. Despite lower total cholesterol levels during the febrile stage compared to convalescent levels, a higher percentage of cholesterol was found as COPs (7beta-, 24-, and 27-hydroxycholesterol). The levels of platelet-activating factor-acetylhydrolase activity, vascular cellular adhesion molecule-1, tumor necrosis factor-alpha, and high-sensitivity C-reactive protein were higher during the febrile stage compared to their convalescent levels (p<0.01). Markers of oxidative damage are altered during the various stages of dengue infection.

  14. Effects of Mountain Ultra-Marathon Running on ROS Production and Oxidative Damage by Micro-Invasive Analytic Techniques

    PubMed Central

    Mrakic-Sposta, Simona; Gussoni, Maristella; Moretti, Sarah; Pratali, Lorenza; Giardini, Guido; Tacchini, Philippe; Dellanoce, Cinzia; Tonacci, Alessandro; Mastorci, Francesca; Borghini, Andrea; Montorsi, Michela; Vezzoli, Alessandra

    2015-01-01

    Purpose Aiming to gain a detailed insight into the physiological mechanisms involved under extreme conditions, a group of experienced ultra-marathon runners, performing the mountain Tor des Géants® ultra-marathon: 330 km trail-run in Valle d’Aosta, 24000 m of positive and negative elevation changes, was monitored. ROS production rate, antioxidant capacity, oxidative damage and inflammation markers were assessed, adopting micro-invasive analytic techniques. Methods Forty-six male athletes (45.04±8.75 yr, 72.6±8.4 kg, 1.76±0.05 m) were tested. Capillary blood and urine were collected before (Pre-), in the middle (Middle-) and immediately after (Post-) Race. Samples were analyzed for: Reactive Oxygen Species (ROS) production by Electron Paramagnetic Resonance; Antioxidant Capacity by Electrochemistry; oxidative damage (8-hydroxy-2-deoxy Guanosine: 8-OH-dG; 8-isoprostane: 8-isoPGF2α) and nitric oxide metabolites by enzymatic assays; inflammatory biomarkers (plasma and urine interleukin-6: IL-6-P and IL-6-U) by enzyme-linked immunosorbent assays (ELISA); Creatinine and Neopterin by HPLC, hematologic (lactate, glucose and hematocrit) and urine parameters by standard analyses. Results Twenty-five athletes finished the race, while twenty-one dropped out of it. A significant increase (Post-Race vs Pre) of the ROS production rate (2.20±0.27 vs 1.65±0.22 μmol.min-1), oxidative damage biomarkers (8-OH-dG: 6.32±2.38 vs 4.16±1.25 ng.mg-1 Creatinine and 8-isoPGF2α: 1404.0±518.30 vs 822.51±448.91 pg.mg-1Creatinine), inflammatory state (IL-6-P: 66.42±36.92 vs 1.29±0.54 pg.mL-1 and IL-6-U: 1.33±0.56 vs 0.71±0.17 pg.mL1) and lactate production (+190%), associated with a decrease of both antioxidant capacity (-7%) and renal function (i.e. Creatinine level +76%) was found. Conclusions The used micro-invasive analytic methods allowed us to perform most of them before, during and immediately after the race directly in the field, by passing the need of storing and

  15. Damage of polyesters by the atmospheric free radical oxidant NO3 (•): a product study involving model systems.

    PubMed

    Goeschen, Catrin; Wille, Uta

    2013-01-01

    Manufactured polymer materials are used in increasingly demanding applications, but their lifetime is strongly influenced by environmental conditions. In particular, weathering and ageing leads to dramatic changes in the properties of the polymers, which results in decreased service life and limited usage. Despite the heavy reliance of our society on polymers, the mechanism of their degradation upon exposure to environmental oxidants is barely understood. In this work, model systems of important structural motifs in commercial high-performing polyesters were used to study the reaction with the night-time free radical oxidant NO3 (•) in the absence and presence of other radical and non-radical oxidants. Identification of the products revealed 'hot spots' in polyesters that are particularly vulnerable to attack by NO3 (•) and insight into the mechanism of oxidative damage by this environmentally important radical. It is suggested that both intermediates as well as products of these reactions are potentially capable of promoting further degradation processes in polyesters under environmental conditions.

  16. Damage of polyesters by the atmospheric free radical oxidant NO3 •: a product study involving model systems

    PubMed Central

    Goeschen, Catrin

    2013-01-01

    Summary Manufactured polymer materials are used in increasingly demanding applications, but their lifetime is strongly influenced by environmental conditions. In particular, weathering and ageing leads to dramatic changes in the properties of the polymers, which results in decreased service life and limited usage. Despite the heavy reliance of our society on polymers, the mechanism of their degradation upon exposure to environmental oxidants is barely understood. In this work, model systems of important structural motifs in commercial high-performing polyesters were used to study the reaction with the night-time free radical oxidant NO3 • in the absence and presence of other radical and non-radical oxidants. Identification of the products revealed ‘hot spots’ in polyesters that are particularly vulnerable to attack by NO3 • and insight into the mechanism of oxidative damage by this environmentally important radical. It is suggested that both intermediates as well as products of these reactions are potentially capable of promoting further degradation processes in polyesters under environmental conditions. PMID:24204400

  17. Dichloroacetate Enhances Apoptotic Cell Death via Oxidative Damage and Attenuates Lactate Production in Metformin-Treated Breast Cancer Cells

    PubMed Central

    Haugrud, Allison B.; Zhuang, Yongxian; Coppock, Joseph D.; Miskimins, W. Keith

    2014-01-01

    Purpose The unique metabolism of breast cancer cells provides interest in exploiting this phenomenon therapeutically. Metformin, a promising breast cancer therapeutic, targets complex I of the electron transport chain leading to an accumulation of reactive oxygen species (ROS) that eventually lead to cell death. Inhibition of complex I leads to lactate production, a metabolic byproduct already highly produced by reprogrammed cancer cells and associated with a poor prognosis. While metformin remains a promising cancer therapeutic, we sought a complementary agent to increase apoptotic promoting effects of metformin while attenuating lactate production possibly leading to greatly improve efficacy. Dichloroacetate (DCA) is a well-established drug used in the treatment of lactic acidosis which functions through inhibition of pyruvate dehydrogenase kinase (PDK) promoting mitochondrial metabolism. Our purpose was to examine the synergy and mechanisms by which these two drugs kill breast cancer cells. Methods Cell lines were subjected to the indicated treatments and analyzed for cell death and various aspects of metabolism. Cell death and ROS production was analyzed using flow cytometry, Western blot analysis, and cell counting methods. Images of cells were taken with phase contrast microscopy or confocal microscopy. Metabolism of cells was analyzed using the Seahorse XF24 analyzer, lactate assays, and pH analysis. Results We show that when DCA and metformin are used in combination, synergistic induction of apoptosis of breast cancer cells occurs. Metformin-induced oxidative damage is enhanced by DCA through PDK1 inhibition which also diminishes metformin promoted lactate production. Conclusions We demonstrate that DCA and metformin combine to synergistically induce caspase-dependent apoptosis involving oxidative damage with simultaneous attenuation of metformin promoted lactate production. Innovative combinations such as metformin and DCA show promise in expanding breast

  18. Alkali production associated with malolactic fermentation by oral streptococci and protection against acid, oxidative, or starvation damage

    PubMed Central

    Sheng, Jiangyun; Baldeck, Jeremiah D.; Nguyen, Phuong T.M.; Quivey, Robert G.; Marquis, Robert E.

    2011-01-01

    Alkali production by oral streptococci is considered important for dental plaque ecology and caries moderation. Recently, malolactic fermentation (MLF) was identified as a major system for alkali production by oral streptococci, including Streptococcus mutans. Our major objectives in the work described in this paper were to further define the physiology and genetics of MLF of oral streptococci and its roles in protection against metabolic stress damage. l-Malic acid was rapidly fermented to l-lactic acid and CO2 by induced cells of wild-type S. mutans, but not by deletion mutants for mleS (malolactic enzyme) or mleP (malate permease). Mutants for mleR (the contiguous regulator gene) had intermediate capacities for MLF. Loss of capacity to catalyze MLF resulted in loss of capacity for protection against lethal acidification. MLF was also found to be protective against oxidative and starvation damage. The capacity of S. mutans to produce alkali from malate was greater than its capacity to produce acid from glycolysis at low pH values of 4 or 5. MLF acted additively with the arginine deiminase system for alkali production by Streptococcus sanguinis, but not with urease of Streptococcus salivarius. Malolactic fermentation is clearly a major process for alkali generation by oral streptococci and for protection against environmental stresses. PMID:20651853

  19. Advanced lipid peroxidation end products in oxidative damage to proteins. Potential role in diseases and therapeutic prospects for the inhibitors

    PubMed Central

    Negre-Salvayre, A; Coatrieux, C; Ingueneau, C; Salvayre, R

    2007-01-01

    Reactive carbonyl compounds (RCCs) formed during lipid peroxidation and sugar glycoxidation, namely Advanced lipid peroxidation end products (ALEs) and Advanced Glycation end products (AGEs), accumulate with ageing and oxidative stress-related diseases, such as atherosclerosis, diabetes or neurodegenerative diseases. RCCs induce the ‘carbonyl stress' characterized by the formation of adducts and cross-links on proteins, which progressively leads to impaired protein function and damages in all tissues, and pathological consequences including cell dysfunction, inflammatory response and apoptosis. The prevention of carbonyl stress involves the use of free radical scavengers and antioxidants that prevent the generation of lipid peroxidation products, but are inefficient on pre-formed RCCs. Conversely, carbonyl scavengers prevent carbonyl stress by inhibiting the formation of protein cross-links. While a large variety of AGE inhibitors has been developed, only few carbonyl scavengers have been tested on ALE-mediated effects. This review summarizes the signalling properties of ALEs and ALE-precursors, their role in the pathogenesis of oxidative stress-associated diseases, and the different agents efficient in neutralizing ALEs effects in vitro and in vivo. The generation of drugs sharing both antioxidant and carbonyl scavenger properties represents a new therapeutic challenge in the treatment of carbonyl stress-associated diseases. PMID:17643134

  20. Determination of oxidative DNA base damage by gas chromatography-mass spectrometry. Effect of derivatization conditions on artifactual formation of certain base oxidation products.

    PubMed

    England, T G; Jenner, A; Aruoma, O I; Halliwell, B

    1998-10-01

    GC-MS is a widely used tool to measure oxidative DNA damage because of its ability to identify a wide range of base modification products. However, it has been suggested that the derivatization procedures required to form volatile products prior to GC-MS analysis can sometimes produce artifactual formation of certain base oxidation products, although these studies did not replicate previously-used reaction conditions, e.g. they failed to remove air from the derivatization vials. A systematic examination of this problem revealed that levels of 8-hydroxyguanine, 8-hydroxyadenine, 5-hydroxycytosine and 5-(hydroxymethyluracil) in commercial calf thymus DNA determined by GC-MS are elevated by increasing the temperature at which derivatization is performed in our laboratory. In particular, 8-hydroxyguanine levels after silylation at 140 degrees C were raised 8-fold compared to derivatization at 23 degrees C. Experiments on the derivatization of each undamaged base revealed that the artifactual oxidation of guanine, adenine, cytosine and thymine respectively was responsible. Formation of the above products was potentiated by not purging with nitrogen prior to derivatization. Increasing the temperature to 140 degrees C or allowing air to be present during derivatization did not significantly increase levels of the other oxidized bases measured. This work suggests that artifactual oxidation during derivatization is restricted to certain products (8-hydroxyguanine, 8-hydroxyadenine, 5-hydroxycytosine and 5-[hydroxymethyluracil]) and can be decreased by reducing the temperature of the derivatization reaction to 23 degrees C and excluding as much air possible. Despite some recent reports, we were easily able to detect formamidopyrimidines in acid-hydrolyzed DNA. Artifacts of derivatization are less marked than has been claimed in some papers and may vary between laboratories, depending on the experimental procedures used, in particular the efficiency of exclusion of O2 during

  1. Curcumin inhibits advanced glycation end product-induced oxidative stress and inflammatory responses in endothelial cell damage via trapping methylglyoxal.

    PubMed

    Sun, Yan Ping; Gu, Jun Fei; Tan, Xiao Bin; Wang, Chun Fei; Jia, Xiao Bin; Feng, Liang; Liu, Ji Ping

    2016-02-01

    Methylglyoxal (MGO)-induced carbonyl stress and pro-inflammatory responses have been suggested to contribute to endothelial dysfunction. Curcumin (Cur), a polyphenolic compound from Curcuma longa L., may protect endothelial cells against carbonyl stress-induced damage by trapping dicarbonyl compounds such as MGO. However, Cur-MGO adducts have not been studied in depth to date and it remains to be known whether Cur-MGO adducts are able to attenuate endothelial damage by trapping MGO. In the present study, 1,2-diaminobenzene was reacted with MGO to ensure the reliability of the reaction system. Cur was demonstrated to trap MGO at a 1:1 ratio to form adducts 1, 2 and 3 within 720 min. The structures of these adducts were identified by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry. The kinetic curves of Cur (10(-7), 10(-6) and 10(-5) M) were measured from 0-168 h by fluorescent intensity. Cur significantly inhibited the formation of advanced glycation end products (AGEs). The differences in oxidative damage and the levels of pro-inflammatory cytokines following MGO + HSA or Cur-MGO treatment were investigated in human umbilical vein endothelial cells (HUVECs). Exposure of HUVECs to the Cur-MGO reaction adducts significantly reduced the intracellular ROS levels and improved cell viability compared with MGO alone. Furthermore, there was a significant reduction in the expression levels of transforming growth factor-β1 and intercellular adhesion molecule(-1) following treatment with Cur-MGO adducts compared with MGO alone. These results provide further evidence that the trapping of MGO by Cur inhibits the formation of AGEs. The current study indicates that the protective effect of Cur on carbonyl stress and pro-inflammatory responses in endothelial damage occurs via the trapping of MGO.

  2. Role of controlled cardiac reoxygenation in reducing nitric oxide production and cardiac oxidant damage in cyanotic infantile hearts.

    PubMed Central

    Morita, K; Ihnken, K; Buckberg, G D; Sherman, M P; Young, H H; Ignarro, L J

    1994-01-01

    Cardiopulmonary bypass (CPB) is used increasingly to correct cyanotic heart defects during early infancy, but myocardial dysfunction is often seen after surgical repair. This study evaluates whether starting CPB at a conventional, hyperoxic pO2 causes an "unintentional" reoxygenation (ReO2) injury. We subjected 2-wk-old piglets to ventilator hypoxemia (FIO2 approximately 0.06, pO2 approximately 25 mmHg) followed by 5 min of ReO2 on CPB before instituting cardioplegia. CPB was begun in hypoxemic piglets by either abrupt ReO2 at a pO2 of 400 mmHg (standard clinical practice) or by maintaining pO2 approximately 25 mmHg on CPB until controlling ReO2 with blood cardioplegic arrest. The effects of abrupt vs. gradual ReO2 without surgical ischemia (blood cardioplegia) were also compared. Myocardial nitric oxide (NO) production (chemiluminescence measurements of NO2- + NO3-) and conjugated diene (CD) generation (spectrophotometric A233 measurements of lipid extracts) using aortic and coronary sinus blood samples were assessed during cardioplegic induction. 30 min after CPB, left ventricular end-systolic elastance (Ees, catheter conductance method) was used to determine cardiac function. CPB and blood cardioplegic arrest caused no functional or biochemical change in normoxic (control) hearts. Abrupt ReO2 caused a depression of myocardial function (Ees = 25 +/- 5% of control). Functional depression was relatively unaffected by gradual ReO2 without blood cardioplegia (34% recovery of Ees), and abrupt ReO2 immediately before blood cardioplegia caused a 10-fold rise in cardiac NO and CD production, with subsequent depression of myocardial function (Ees 21 +/- 2% of control). In contrast, controlled cardiac ReO2 reduced NO production 94%, CD did not rise, and Ees was 83 +/- 8% of normal. We conclude ReO2 injury is related to increased NO production during abrupt ReO2, nullifies the cardioprotective effects of blood cardioplegia, and that controlled cardiac ReO2 when starting CPB

  3. OXIDATIVE DNA DAMAGE AND REPAIR IN RATS TREATED WITH POTASSIUM BROMATE AND A MIXTUE OF DRINKING WATER DISINFECTION BY-PRODUCTS

    EPA Science Inventory

    Oxidative DNA Damage and Repair in Rats Treated with Potassium Bromate and a Mixture of Drinking Water Disinfection By-Products

    Public drinking water treated with chemical disint'ectants contains a complex mixture of disinfection by-products (D BPs). There is a need for m...

  4. Chlorogenic acid improves ex vivo vessel function and protects endothelial cells against HOCl-induced oxidative damage, via increased production of nitric oxide and induction of Hmox-1.

    PubMed

    Jiang, Rujia; Hodgson, Jonathan M; Mas, Emilie; Croft, Kevin D; Ward, Natalie C

    2016-01-01

    Dietary polyphenols are potential contributors toward improved cardiovascular health. Coffee is one of the richest sources of dietary polyphenols in a coffee-drinking population, the most abundant form being chlorogenic acid (CGA). Endothelial dysfunction is an early and major risk factor for cardiovascular disease. Nitric oxide (NO) is a key factor in regulation of endothelial function. Heme oxygenase-1 (Hmox-1), an inducible isoform of heme oxygenase that is produced in response to stressors such as oxidative stress, may also play a role in vascular protection. The aim of this study was to investigate the effect of CGA on endothelial function with oxidant-induced damage in isolated aortic rings from C57BL mice. We further examine the mechanism by investigating cell viability, activation of eNOS and induction of Hmox-1 in human aortic endothelial cells (HAECs). We found that pretreatment of isolated aortic rings with 10-μM CGA-protected vessels against HOCl-induced endothelial dysfunction (P<0.05). Pretreatment of cultured HAECs with 10-μM CGA increased endothelial cell viability following exposure to HOCl (P<0.05). Moreover, CGA increased NO production in HAECs in a dose-dependent manner, peaking at 6 h (P<0.05). CGA at 5 μM and 10 μM increased eNOS dimerization at 6 h and induced Hmox-1 protein expression at 6 h and 24 h in HAECs. These results are consistent with the cardiovascular protective effects of coffee polyphenols and demonstrate that CGA can protect vessels and cultured endothelial cells against oxidant-induced damage. The mechanism behind the beneficial effect of CGA appears to be in part via increased production of NO and induction of Hmox-1. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Ultrasensitive determination of DNA oxidation products by gas chromatography-tandem mass spectrometry and the role of antioxidants in the prevention of oxidative damage.

    PubMed

    Dawbaa, Sam; Aybastıer, Önder; Demir, Cevdet

    2017-04-15

    Oxidative stress is considered as one of the significant causes of DNA damage which in turn contributes to cell death through a series of intermediate processes such as cancer formation, mutation, and aging. Natural sources such as plant and fruit products have provided us with interesting substances of antioxidant activity that could be recruited in protecting the genetic materials of the cells. This study is an effort to discover some of those antioxidants effects in their standard and natural forms by performing an ultrasensitive determination of the products of DNA oxidation using GC-MS/MS. Experiments were used to determine the direct antioxidant activity of the substances contained in the tendrils of Vitis vinifera (var. alphonse) by extracting them and achieving Folin-Ciocalteau and CHROMAC analyses to determine the total phenolic content (TPC) and the antioxidant capacity of the extract, respectively; results revealed a phenolic content of 11.39±0.30mg Gallic Acid Equivalent (GAE)/g of the plant's fresh weight (FW) by Folin-Ciocalteau and 8.17±0.49mg Trolox Equivalent (TE)/g FW by CHROMAC assays. The qualitative analysis of the plant extract by HPLC-DAD technique revealed that two flavonoid glycosides namely rutin and isoquercitrin in addition to chlorogenic acid were contained in the extract. The determination of the DNA oxidation products was performed after putting DNA, rutin and isoquercitrin standard samples with different concentration, and the extract's sample under oxidative stress. Eighteen DNA oxidation products were traced using GC-MS/MS with ultra-sensitivity and the experiments proved a significant decrease in the concentration of the DNA oxidation products when the extract was used as a protectant against the oxidative stress. It is believed by conclusion that the extract of V. vinifera's (var. alphonse) tendrils has a good antioxidant activity; hence it is recommended to be used as a part of the daily healthy food list if possible

  6. Oxidative stress responses and lipid peroxidation damage are induced during dehydration in the production of dry active wine yeasts.

    PubMed

    Garre, Elena; Raginel, Françoise; Palacios, Antonio; Julien, Anne; Matallana, Emilia

    2010-01-01

    The tolerance of the yeast Saccharomyces cerevisiae to desiccation is important for the use of this microorganism in the wine industry, since active dry wine yeast is routinely used as starter for must fermentations. Many studies have shown the complexity of the cellular effects caused by water loss, including oxidative injuries on macromolecular components. However the technological interest of yeast drying was not addressed in those studies, and the dehydration conditions were far from the industrial practice. In the present study a molecular approach was used to characterize the relevant injuring conditions during pilot plant dehydration under two different drying temperatures (i.e., 35 and 41 degrees C). We have analyzed expression changes for several stress gene markers and we have determined two biochemical redox indicators (glutathione and lipid peroxidation levels) during pilot plant dehydration to produce active dry biomass, according to the standard practice in industry. The main gene expression response involves the induction of genes TRR1 and GRX5, corresponding to the two main redox balance systems, thioredoxins and glutathione/glutaredoxins. Elevated glutathione content and significant lipid peroxidation damage indicate the physiological impact of the oxidative stress on cellular components. The comparison between commercial stocks and pilot plant samples demonstrate the suitability of the molecular approach at the pilot plant scale to study physiological traits of industrial yeast products.

  7. Oxidative DNA damage estimated by urinary 8-hydroxy-2'-deoxyguanosine and arsenic in glass production workers.

    PubMed

    Lin, Tser-Sheng; Wu, Chin-Ching; Wu, Jyun-De; Wei, Chun-Han

    2012-07-01

    A total of 130 male glass workers, including 33 administrative workers, 18 batch house workers, 42 craftsmen, and 37 melting process workers, were recruited to investigate the potential DNA damage resulting from toxic element exposure. The occupational exposure to trace elements, including arsenic (As), cadmium (Cd), manganese (Mn), nickel (Ni), lead (Pb), and selenium (Se), was estimated by their urinary levels as internal doses. In addition, all participants filled a self-filled questionnaire indicating their individual information. The average levels of urinary As, Cd, Mn, Ni, Pb, Se, and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were 282.3 ± 464.6, 3.07 ± 5.39, 3.81 ± 11.43, 81.48 ± 138.9, 18.23 ± 49.61, 165.2 ± 224.9, and 17.21 ± 26.34 μg/g creatinine, respectively. The urinary levels of 8-OHdG and toxic elements were strongly associated with the work nature of the worker, with an exception of Mn and Pb. In contrast, the levels of toxic element were not influenced by age, smoking behavior, and alcohol consumption. The urinary 8-OHdG was found significantly higher in higher internal exposure groups of As, Cd, Ni, and Se. However, the stepwise multiple regression models showed that urinary 8-OHdG was only associated with urinary As and heat stress but inversely with age.

  8. CYTOTOXIC PHOSPHOLIPID OXIDATION PRODUCTS

    PubMed Central

    Chen, Rui; Yang, Lili; McIntyre, Thomas M.

    2008-01-01

    Phospholipid oxidation products accumulate in the necrotic core of atherosclerotic lesions, in apoptotic cells, and circulate in oxidized LDL. Phospholipid oxidation generates toxic products, but little is known about which specific products are cytotoxic, their receptors, or the mechanism(s) that induces cell death. We find the most common phospholipid oxidation product of oxidized LDL, phosphatidylcholine with esterified sn-2 azelaic acid, induced apoptosis at low micromolar concentrations. The synthetic ether phospholipid hexadecyl azelaoyl phosphatidylcholine (HAzPC) was rapidly internalized, and over-expression of PLA2g7 (PAF acetylhydrolase) that specifically hydrolyzes such oxidized phospholipids suppressed apoptosis. Internalized HAzPC associated with mitochondria, and cytochrome C and apoptosis-inducing factor escaped from mitochondria to the cytoplasm and nucleus, respectively, in cells exposed to HAzPC. Isolated mitochondria exposed to HAzPC rapidly swelled, and released cytochrome C and apoptosis-inducing factor. Other phospholipid oxidation products induced swelling, but HAzPC was the most effective and was twice as effective as its diacyl homolog. Cytoplasmic cytochrome C completes the apoptosome, and activated caspase 9 and 3 were present in cells exposed to HAzPC. Irreversible inhibition of caspase 9 blocked downstream caspase 3 activation, and prevented apoptosis. Mitochondrial damage initiated this apoptotic cascade because over-expression of Bcl-XL, an anti-apoptotic protein localized to mitochondria, blocked cytochrome C escape, and apoptosis. Thus, exogenous phospholipid oxidation products target intracellular mitochondria to activate the intrinsic apoptotic cascade. PMID:17597068

  9. Quantification of DNA damage products resulting from deamination, oxidation and reaction with products of lipid peroxidation by liquid chromatography isotope dilution tandem mass spectrometry

    PubMed Central

    Taghizadeh, Koli; McFaline, Jose L.; Pang, Bo; Sullivan, Matthew; Dong, Min; Plummer, Elaine; Dedon, Peter C.

    2009-01-01

    The analysis of damage products as biomarkers of inflammation has been hampered by a poor understanding of the chemical biology of inflammation, the lack of sensitive analytical methods, and a focus on single chemicals as surrogates for inflammation. To overcome these problems, we developed a general and sensitive liquid chromatographic tandem mass spectrometry (LC/MS-MS) method to quantify, in a single DNA sample, the nucleoside forms of seven DNA lesions reflecting the range of chemistries associated with inflammation: 2′-deoxyuridine, 2′-deoxyxanthosine, and 2′-deoxyinosine from nitrosative deamination; 8-oxo-2′-deoxyguanosine from oxidation; and 1,N2-etheno-2′-deoxyguanosine, 1,N6-etheno-2′-deoxyadenosine, and 3,N4-etheno-2′-deoxycytidine arising from reaction of DNA with lipid peroxidation products. Using DNA purified from cells or tissues under conditions that minimize artifacts, individual nucleosides are purified by HPLC and quantified by isotope-dilution, electrospray ionization LC/MS-MS. The method can be applied to other DNA damage products and requires 4-6 days to complete depending upon the number of samples. PMID:18714297

  10. Understanding and preventing mitochondrial oxidative damage

    PubMed Central

    Murphy, Michael P.

    2016-01-01

    Mitochondrial oxidative damage has long been known to contribute to damage in conditions such as ischaemia–reperfusion (IR) injury in heart attack. Over the past years, we have developed a series of mitochondria-targeted compounds designed to ameliorate or determine how this damage occurs. I will outline some of this work, from MitoQ to the mitochondria-targeted S-nitrosating agent, called MitoSNO, that we showed was effective in preventing reactive oxygen species (ROS) formation in IR injury with therapeutic implications. In addition, the protection by this compound suggested that ROS production in IR injury was mainly coming from complex I. This led us to investigate the mechanism of the ROS production and using a metabolomic approach, we found that the ROS production in IR injury came from the accumulation of succinate during ischaemia that then drove mitochondrial ROS production by reverse electron transport at complex I during reperfusion. This surprising mechanism led us to develop further new therapeutic approaches to have an impact on the damage that mitochondrial ROS do in pathology and also to explore how mitochondrial ROS can act as redox signals. I will discuss how these approaches have led to a better understanding of mitochondrial oxidative damage in pathology and also to the development of new therapeutic strategies. PMID:27911703

  11. Coccidian Infection Causes Oxidative Damage in Greenfinches

    PubMed Central

    Sepp, Tuul; Karu, Ulvi; Blount, Jonathan D.; Sild, Elin; Männiste, Marju; Hõrak, Peeter

    2012-01-01

    The main tenet of immunoecology is that individual variation in immune responsiveness is caused by the costs of immune responses to the hosts. Oxidative damage resulting from the excessive production of reactive oxygen species during immune response is hypothesized to form one of such costs. We tested this hypothesis in experimental coccidian infection model in greenfinches Carduelis chloris. Administration of isosporan coccidians to experimental birds did not affect indices of antioxidant protection (TAC and OXY), plasma triglyceride and carotenoid levels or body mass, indicating that pathological consequences of infection were generally mild. Infected birds had on average 8% higher levels of plasma malondialdehyde (MDA, a toxic end-product of lipid peroxidation) than un-infected birds. The birds that had highest MDA levels subsequent to experimental infection experienced the highest decrease in infection intensity. This observation is consistent with the idea that oxidative stress is a causative agent in the control of coccidiosis and supports the concept of oxidative costs of immune responses and parasite resistance. The finding that oxidative damage accompanies even the mild infection with a common parasite highlights the relevance of oxidative stress biology for the immunoecological research. PMID:22615772

  12. Oxidant damage during and after spaceflight

    NASA Technical Reports Server (NTRS)

    Stein, T. P.; Leskiw, M. J.

    2000-01-01

    The objectives of this study were to assess oxidant damage during and after spaceflight and to compare the results against bed rest with 6 degrees head-down tilt. We measured the urinary excretion of the F(2) isoprostane, 8-iso-prostaglandin (PG) F(2alpha), and 8-oxo-7,8-dihydro-2 deoxyguanosine (8-OH DG) before, during, and after long-duration spaceflight (4-9 mo) on the Russian space station MIR, short-duration spaceflight on the shuttle, and 17 days of bed rest. Sample collections on MIR were obtained between 88 and 186 days in orbit. 8-iso-PGF(2alpha) and 8-OH DG are markers for oxidative damage to membrane lipids and DNA, respectively. Data are mean +/- SE. On MIR, isoprostane levels were decreased inflight (96. 9 +/- 11.6 vs. 76.7 +/- 14.9 ng. kg(-1). day(-1), P < 0.05, n = 6) due to decreased dietary intake secondary to impaired thermoregulation. Isoprostane excretion was increased postflight (245.7 +/- 55.8 ng. kg(-1). day(-1), P < 0.01). 8-OH DG excretion was unchanged with spaceflight and increased postflight (269 +/- 84 vs 442 +/- 180 ng. kg(-1). day(-1), P < 0.05). On the shuttle, 8-OH DG excretion was unchanged in- and postflight, but 8-iso-PGF(2alpha) excretion was decreased inflight (15.6 +/- 4.3 vs 8.0 +/- 2.7 ng. kg(-1). day(-1), P < 0.05). No changes were found with bed rest, but 8-iso-PGF(2alpha) was increased during the recovery phase (48.9 +/- 23.0 vs 65.4 +/- 28.3 ng. kg(-1). day(-1), P < 0.05). The changes in isoprostane production were attributed to decreased production of oxygen radicals from the electron transport chain due to the reduced energy intake inflight. The postflight increases in the excretion of the products of oxidative damage were attributed to a combination of an increase in metabolic activity and the loss of some host antioxidant defenses inflight. We conclude that 1) oxidative damage was decreased inflight, and 2) oxidative damage was increased postflight.

  13. Oxidant damage during and after spaceflight

    NASA Technical Reports Server (NTRS)

    Stein, T. P.; Leskiw, M. J.

    2000-01-01

    The objectives of this study were to assess oxidant damage during and after spaceflight and to compare the results against bed rest with 6 degrees head-down tilt. We measured the urinary excretion of the F(2) isoprostane, 8-iso-prostaglandin (PG) F(2alpha), and 8-oxo-7,8-dihydro-2 deoxyguanosine (8-OH DG) before, during, and after long-duration spaceflight (4-9 mo) on the Russian space station MIR, short-duration spaceflight on the shuttle, and 17 days of bed rest. Sample collections on MIR were obtained between 88 and 186 days in orbit. 8-iso-PGF(2alpha) and 8-OH DG are markers for oxidative damage to membrane lipids and DNA, respectively. Data are mean +/- SE. On MIR, isoprostane levels were decreased inflight (96. 9 +/- 11.6 vs. 76.7 +/- 14.9 ng. kg(-1). day(-1), P < 0.05, n = 6) due to decreased dietary intake secondary to impaired thermoregulation. Isoprostane excretion was increased postflight (245.7 +/- 55.8 ng. kg(-1). day(-1), P < 0.01). 8-OH DG excretion was unchanged with spaceflight and increased postflight (269 +/- 84 vs 442 +/- 180 ng. kg(-1). day(-1), P < 0.05). On the shuttle, 8-OH DG excretion was unchanged in- and postflight, but 8-iso-PGF(2alpha) excretion was decreased inflight (15.6 +/- 4.3 vs 8.0 +/- 2.7 ng. kg(-1). day(-1), P < 0.05). No changes were found with bed rest, but 8-iso-PGF(2alpha) was increased during the recovery phase (48.9 +/- 23.0 vs 65.4 +/- 28.3 ng. kg(-1). day(-1), P < 0.05). The changes in isoprostane production were attributed to decreased production of oxygen radicals from the electron transport chain due to the reduced energy intake inflight. The postflight increases in the excretion of the products of oxidative damage were attributed to a combination of an increase in metabolic activity and the loss of some host antioxidant defenses inflight. We conclude that 1) oxidative damage was decreased inflight, and 2) oxidative damage was increased postflight.

  14. Lower oxidative DNA damage despite greater ROS production in muscles from rats selectively bred for high running capacity.

    PubMed

    Tweedie, Constance; Romestaing, Caroline; Burelle, Yan; Safdar, Adeel; Tarnopolsky, Mark A; Seadon, Scott; Britton, Steven L; Koch, Lauren G; Hepple, Russell T

    2011-03-01

    Artificial selection in rat has yielded high-capacity runners (HCR) and low-capacity runners (LCR) that differ in intrinsic (untrained) aerobic exercise ability and metabolic disease risk. To gain insight into how oxygen metabolism may have been affected by selection, we compared mitochondrial function, oxidative DNA damage (8-dihydroxy-guanosine; 8dOHG), and antioxidant enzyme activities in soleus muscle (Sol) and gastrocnemius muscle (Gas) of adult and aged LCR vs. HCR rats. In Sol of adult HCR rats, maximal ADP-stimulated respiration was 37% greater, whereas in Gas of adult HCR rats, there was a 23% greater complex IV-driven respiratory capacity and 54% greater leak as a fraction of electron transport capacity (suggesting looser mitochondrial coupling) vs. LCR rats. H(2)O(2) emission per gram of muscle was 24-26% greater for both muscles in adult HCR rats vs. LCR, although H(2)O(2) emission in Gas was 17% lower in HCR, after normalizing for citrate synthase activity (marker of mitochondrial content). Despite greater H(2)O(2) emission, 8dOHG levels were 62-78% lower in HCR rats due to 62-96% higher superoxide dismutase activity in both muscles and 47% higher catalase activity in Sol muscle in adult HCR rats, with no evidence for higher 8 oxoguanine glycosylase (OGG1; DNA repair enzyme) protein expression. We conclude that genetic segregation for high running capacity has generated a molecular network of cellular adaptations, facilitating a superior response to oxidative stress.

  15. Lung Oxidative Damage by Hypoxia

    PubMed Central

    Araneda, O. F.; Tuesta, M.

    2012-01-01

    One of the most important functions of lungs is to maintain an adequate oxygenation in the organism. This organ can be affected by hypoxia facing both physiological and pathological situations. Exposure to this condition favors the increase of reactive oxygen species from mitochondria, as from NADPH oxidase, xanthine oxidase/reductase, and nitric oxide synthase enzymes, as well as establishing an inflammatory process. In lungs, hypoxia also modifies the levels of antioxidant substances causing pulmonary oxidative damage. Imbalance of redox state in lungs induced by hypoxia has been suggested as a participant in the changes observed in lung function in the hypoxic context, such as hypoxic vasoconstriction and pulmonary edema, in addition to vascular remodeling and chronic pulmonary hypertension. In this work, experimental evidence that shows the implied mechanisms in pulmonary redox state by hypoxia is reviewed. Herein, studies of cultures of different lung cells and complete isolated lung and tests conducted in vivo in the different forms of hypoxia, conducted in both animal models and humans, are described. PMID:22966417

  16. Lung oxidative damage by hypoxia.

    PubMed

    Araneda, O F; Tuesta, M

    2012-01-01

    One of the most important functions of lungs is to maintain an adequate oxygenation in the organism. This organ can be affected by hypoxia facing both physiological and pathological situations. Exposure to this condition favors the increase of reactive oxygen species from mitochondria, as from NADPH oxidase, xanthine oxidase/reductase, and nitric oxide synthase enzymes, as well as establishing an inflammatory process. In lungs, hypoxia also modifies the levels of antioxidant substances causing pulmonary oxidative damage. Imbalance of redox state in lungs induced by hypoxia has been suggested as a participant in the changes observed in lung function in the hypoxic context, such as hypoxic vasoconstriction and pulmonary edema, in addition to vascular remodeling and chronic pulmonary hypertension. In this work, experimental evidence that shows the implied mechanisms in pulmonary redox state by hypoxia is reviewed. Herein, studies of cultures of different lung cells and complete isolated lung and tests conducted in vivo in the different forms of hypoxia, conducted in both animal models and humans, are described.

  17. Inflammation, oxidative DNA damage, and carcinogenesis

    SciTech Connect

    Lewis, J.G.; Adams, D.O.

    1987-12-01

    Inflammation has long been associated with carcinogenesis, especially in the promotion phase. The mechanism of action of the potent inflammatory agent and skin promoter 12-tetradecanoyl phorbol-13-acetate (TPA) is unknown. It is though that TPA selectively enhances the growth of initiated cells, and during this process, initiated cells progress to the preneoplastic state and eventually to the malignant phenotype. The authors and others have proposed that TPA may work, in part, by inciting inflammation and stimulating inflammatory cells to release powerful oxidants which then induce DNA damage in epidermal cells. Macrophages cocultured with target cells and TPA induce oxidized thymine bases in the target cells. This process is inhibited by both catalase and inhibitors of lipoxygenases, suggesting the involvement of both H/sub 2/O/sub 2/ and oxidized lipid products. In vivo studies demonstrated that SENCAR mice, which are sensitive to promotion by TPA, have a more intense inflammatory reaction in skin that C57LB/6 mice, which are resistant to promotion by TPA. In addition, macrophages from SENCAR mice release more H/sub 2/O/sub 2/ and metabolites of AA, and induce more oxidative DNA damage in cocultured cells than macrophages from C57LB/6 mice. These data support the hypothesis that inflammation and the release of genotoxic oxidants may be one mechanism whereby initiated cells receive further genetic insults. They also further complicate risk assessment by suggesting that some environmental agents may work indirectly by subverting host systems to induce damage rather than maintaining homeostasis.

  18. Inflammation, oxidative DNA damage, and carcinogenesis.

    PubMed Central

    Lewis, J G; Adams, D O

    1987-01-01

    Inflammation has long been associated with carcinogenesis, especially in the promotion phase. The mechanism of action of the potent inflammatory agent and skin promoter 12-tetradecanoyl phorbol-13-acetate (TPA) is unknown. It is thought that TPA selectively enhances the growth of initiated cells, and during this process, initiated cells progress to the preneoplastic state and eventually to the malignant phenotype. Many studies support the multistep nature of carcinogenesis, and a significant amount of evidence indicates that more than one genetic event is necessary for neoplastic transformation. Selective growth stimulation of initiated cells by TPA does not explain how further genetic events may occur by chronic exposure to this nongenotoxic agent. We and others have proposed that TPA may work, in part, by inciting inflammation and stimulating inflammatory cells to release powerful oxidants which then induce DNA damage in epidermal cells. Macrophages cocultured with target cells and TPA induce oxidized thymine bases in the target cells. This process is inhibited by both catalase and inhibitors of lipoxygenases, suggesting the involvement of both H2O2 and oxidized lipid products. Furthermore, macrophage populations that release both H2O2 and metabolites of arachidonic acid (AA) are more efficient at inducing oxidative DNA damage in surrounding cells than populations which only release H2O2 or metabolites of AA. In vivo studies demonstrated that SENCAR mice, which are sensitive to promotion by TPA, have a more intense inflammatory reaction in skin than C57LB/6 mice, which are resistant to promotion by TPA. In addition, macrophages from SENCAR mice release more H2O2 and metabolites of AA, and induce more oxidative DNA damage in cocultured cells than macrophages from C57LB/6 mice.(ABSTRACT TRUNCATED AT 250 WORDS) Images FIGURE 8. A FIGURE 8. B PMID:3129286

  19. Influence of salicylic acid on H2O2 production, oxidative stress, and H2O2-metabolizing enzymes. Salicylic acid-mediated oxidative damage requires H2O2.

    PubMed Central

    Rao, M V; Paliyath, G; Ormrod, D P; Murr, D P; Watkins, C B

    1997-01-01

    We investigated how salicylic acid (SA) enhances H2O2 and the relative significance of SA-enhanced H2O2 in Arabidopsis thaliana. SA treatments enhanced H2O2 production, lipid peroxidation, and oxidative damage to proteins, and resulted in the formation of chlorophyll and carotene isomers. SA-enhanced H2O2 levels were related to increased activities of Cu,Zn-superoxide dismutase and were independent of changes in catalase and ascorbate peroxidase activities. Prolonging SA treatments inactivated catalase and ascorbate peroxidase and resulted in phytotoxic symptoms, suggesting that inactivation of H2O2-degrading enzymes serves as an indicator of hypersensitive cell death. Treatment of leaves with H2O2 alone failed to invoke SA-mediated events. Although leaves treated with H2O2 accumulated in vivo H2O2 by 2-fold compared with leaves treated with SA, the damage to membranes and proteins was significantly less, indicating that SA can cause greater damage than H2O2. However, pretreatment of leaves with dimethylthiourea, a trap for H2O2, reduced SA-induced lipid peroxidation, indicating that SA requires H2O2 to initiate oxidative damage. The relative significance of the interaction among SA, H2O2, and H2O2-metabolizing enzymes with oxidative damage and cell death is discussed. PMID:9306697

  20. Urinary levels of oxidative DNA and RNA damage among workers exposed to polycyclic aromatic hydrocarbons in silicon production: comparison with 1-hydroxypyrene.

    PubMed

    Marie, Caroline; Ravanat, Jean-Luc; Badouard, Carine; Marques, Marie; Balducci, Franck; Maître, Anne

    2009-03-01

    Polycyclic aromatic hydrocarbons (PAH) are ubiquitous occupational and environmental pollutants and the urinary excretion of 1-hydroxypyrene (1-OHP) is classically measured for the determination of PAH exposure internal dose. Some of PAH are tumorigenic due to their metabolites ability to generate DNA adducts and oxidative DNA damage through the production of reactive oxygen species during metabolism. 8-hydroxy-7,8-dihydro-2'-deoxyguanosine (8-OHdGuo) is one of the major oxidative DNA lesions and its use as a potential biomarker of genotoxic PAH occupational exposure should be evaluated. Indeed conflicting results are frequently reported in occupational studies in terms of correlation between 8-OHdGuo urinary levels and PAH exposure. The aim of our study was therefore to determine the potential for PAH occupational exposure to increase urinary oxidative DNA damage. The population consisted of 68 male workers employed in silicon production. The urinary concentrations of 8-OHdGuo and its homologue in RNA, 8-hydroxy-7,8-dihydroguanosine (8-OHGuo) were determined using high performance liquid chromatography (HPLC) coupled to tandem mass spectrometry, whereas those of 1-OHP were measured using HPLC with fluorescence detection. Individual variation rates were calculated on a working day and a working week. The results indicated that, while 1-OHP levels strongly increased on a working day and even more on a working week, 8-OHdGuo and 8-OHGuo urinary levels did not show similar significant increases. Moreover, no correlation between 1-OHP and oxidative DNA and RNA lesions was found. Consequently, urinary 8-OHdGuo and 8-OHGuo did not seem to be relevant biomarkers of genotoxic PAH exposure in the case of the silicon plant studied.

  1. Curcumin protects against acute liver damage in the rat by inhibiting NF-kappaB, proinflammatory cytokines production and oxidative stress.

    PubMed

    Reyes-Gordillo, Karina; Segovia, José; Shibayama, Mineko; Vergara, Paula; Moreno, Mario G; Muriel, Pablo

    2007-06-01

    Curcumin, an anti-inflammatory and antioxidant compound, was evaluated for its ability to suppress acute carbon tetrachloride-induced liver damage. Acute hepatotoxicity was induced by oral administration of CCl4 (4 g/kg, p.o.). Curcumin treatment (200 mg/kg, p.o.) was given before and 2 h after CCl4 administration. Indicators of necrosis (alanine aminotransferase) and cholestasis (gamma-glutamyl transpeptidase and bilirubins) resulted in significant increases after CCl4 intoxication, but these effects were prevented by curcumin treatment. As an indicator of oxidative stress, GSH was oxidized and the GSH/GSSG ratio decreased significantly by CCl4, but was preserved within normal values by curcumin. In addition to its antioxidants properties, curcumin is capable of preventing NF-kappaB activation and therefore to prevent the secretion of proinflammatory cytokines. Therefore, in this study we determined the concentrations of tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and interleukin-6 (IL-6) mRNA, and NF-kappaB activation. CCl4-administered rats depicted significant increases in TNF-alpha, IL-1beta, and IL-6 production, while curcumin remarkably suppressed these mediators of inflammation in liver damage. These results were confirmed by measuring TNF-alpha, and IL-1beta protein production using Western Blot analysis. Accordingly, these proteins were increased by CCl4 and this effect was abolished by curcumin. Administration of CCl4 induced the translocation of NF-kappaB to the nucleus; CCl4 induced NF-kappaB DNA binding activity was blocked by curcumin treatment. These findings suggest that curcumin prevents acute liver damage by at least two mechanisms: acting as an antioxidant and by inhibiting NF-kappaB activation and thus production of proinflammatory cytokines.

  2. "Action-at-a distance" of a new DNA oxidative damage product 6-furfuryl-adenine (kinetin) on template properties of modified DNA.

    PubMed

    Wyszko, Eliza; Barciszewska, Mirosława Z; Markiewicz, Maria; Szymański, Maciej; Markiewicz, Wojciech T; Clark, Brian F C; Barciszewski, Jan

    2003-02-20

    N(6)-furfuryladenine (kinetin, K) was shown to have cytokinin activity and antiageing effects. It also appears to protect DNA against oxidative damage mediated by the Fenton reaction. Kinetin was identified as a natural component of DNA in plant extract, calf thymus DNA, fresh DNA preparations from human cell culture, as well as in human urine. A proposed mechanism of kinetin synthesis includes furfural, the oxidative damage product of a 2-deoxyribose moiety of DNA, which reacts with an adenine residue to form N(6)-furfuryladenine at DNA level. The identification of kinetin in plant cell extracts, as well as human urine, suggests its excision from DNA by repair mechanisms. Since such a bulky modification as kinetin induces conformational changes of DNA, this could lead to mutations. Therefore, it was interesting to analyze an effect of kinetin on coding properties of DNA. Chemically synthesized oligodeoxynucleotide (20-mer) containing kinetin AAAACTGCCGTCCTGAKGAT was used as a primer. It was elongated in a polymerase chain reaction (PCR) on a template plasmid pEW1 harboring a 210-bp fragment of DNA derived from the 5' end of HIV mRNA. The PCR product of that length containing kinetin in position 17 from the 5' end was isolated and sequenced. Interestingly, DNA polymerase correctly incorporates thymine opposite of kinetin (an adenine derivative) on the complementary strand, but the misincorporations occur in a vicinity of the modified base.

  3. Early oxidative damage induced by doxorubicin: Source of production, protection by GKT137831 and effect on Ca(2+) transporters in HL-1 cardiomyocytes.

    PubMed

    Asensio-López, Mari C; Soler, Fernando; Sánchez-Más, Jesús; Pascual-Figal, Domingo; Fernández-Belda, Francisco; Lax, Antonio

    2016-03-15

    In atrial-derived HL-1 cells, ryanodine receptor and Na(+)/Ca(2+)-exchanger were altered early by 5 μM doxorubicin. The observed effects were an increase of cytosolic Ca(2+) at rest, ensuing ryanodine receptor phosphorylation, and the slowing of Ca(2+) transient decay after caffeine addition. Doxorubicin triggered a linear rise of reactive oxygen species (ROS) with no early effect on mitochondrial inner membrane potential. Doxorubicin and ROS were both detected in mitochondria by colocalization with fluorescence probes and doxorubicin-induced ROS was totally blocked by mitoTEMPO. The NADPH oxidase activity in the mitochondrial fraction was sensitive to inhibition by GKT137831, and doxorubicin-induced ROS decreased gradually as the GKT137831 concentration added in preincubation was increased. When doxorubicin-induced ROS was prevented by GKT137831, the kinetic response revealed a permanent degree of protection that was consistent with mitochondrial NADPH oxidase inhibition. In contrast, the ROS induction by doxorubicin after melatonin preincubation was totally eliminated at first but the effect was completely reversed with time. Limiting the source of ROS production is a better alternative for dealing with oxidative damage than using ROS scavengers. The short-term effect of doxorubicin on Ca(2+) transporters involved in myocardiac contractility was dependent on oxidative damage, and so the impairment was subsequent to ROS production. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. NapA protects Helicobacter pylori from oxidative stress damage, and its production is influenced by the ferric uptake regulator.

    PubMed

    Cooksley, Clare; Jenks, Peter J; Green, Andrew; Cockayne, Alan; Logan, Robert P H; Hardie, Kim R

    2003-06-01

    The Helicobacter pylori protein NapA has been identified as a homologue of the Escherichia coli protein Dps. It is shown in this study that, like Dps, NapA is produced maximally in stationary phase cells and contributes to the ability of H. pylori to survive under oxidative stress conditions. Moreover, NapA co-localizes with the nuclear material, suggesting that it can interact with DNA in vivo. Furthermore, it is demonstrated that repression of NapA production by iron starvation was not so pronounced in a H. pylori fur mutant, suggesting that the ferric uptake regulator (Fur) is involved in napA regulation, and a potential fur box by which this control could be mediated is identified. This finding is consistent with the regulation of iron-binding proteins by Fur and also the modulation of Fur during oxidative stress, thus allowing NapA levels to be increased in the environmental conditions under which its ability to protect DNA from attack by toxic free radicals is most beneficial to the cell.

  5. Tissue damage and oxidant/antioxidant balance.

    PubMed

    Kisaoglu, Abdullah; Borekci, Bunyamin; Yapca, O Erkan; Bilen, Habib; Suleyman, Halis

    2013-02-01

    The oxidant/antioxidant balance in healthy tissues is maintained with a predominance of antioxidants. Various factors that can lead to tissue damage disrupt the oxidant/antioxidant balance in favor of oxidants. In this study, disruptions of the oxidant/antioxidant balance in favor of oxidants were found to be a consequence of the over-consumption of antioxidants. For this reason, antioxidants are considered to be of importance in the prevention and treatment of various types of tissue damage that are aggravated by stress.

  6. Electrochemical study of DNA damaged by oxidation stress.

    PubMed

    Zitka, Ondrej; Krizkova, Sona; Skalickova, Sylvie; Kopel, Pavel; Babula, Petr; Adam, Vojtech; Kizek, Rene

    2013-02-01

    Many compounds can interact with DNA leading to changes of DNA structure as point mutation and bases excision, which could trigger some metabolic failures, which leads to the changes in DNA structure resulting in cancer. Oxidation of nucleic acid bases belongs to the one of the mostly occurred type of DNA damaging leading to the above mentioned phenomena. The investigation of processes of DNA oxidation damage is topical and electrochemical methods include a versatile and sensitive tool for these purposes. 8-hydroxydeoxyguanosine (8-OHdG) is the most widely accepted marker of DNA damage. Oxidative damage to DNA by free radicals and exposure to ionizing radiation generate several other products within the double helix besides mentioned oxidation products of nucleic acid bases. The basic electrochemical behaviour of nucleic acids bases on various types of carbon electrodes is reviewed. Further, we address our attention on description of oxidation mechanisms and on detection of the most important products of nucleic bases oxidation. The miniaturization of detector coupled with some microfluidic devices is suggested and discussed. The main aim of this review is to report the advantages and features of the electrochemical detection of guanine oxidation product as 8-OHdG and other similarly produced molecules as markers for DNA damage.

  7. Oxidative DNA damage & repair: An introduction.

    PubMed

    Cadet, Jean; Davies, Kelvin J A

    2017-06-01

    This introductory article should be viewed as a prologue to the Free Radical Biology & Medicine Special Issue devoted to the important topic of Oxidatively Damaged DNA and its Repair. This special issue is dedicated to Professor Tomas Lindahl, co-winner of the 2015 Nobel Prize in Chemistry for his seminal discoveries in the area repair of oxidatively damaged DNA. In the past several years it has become abundantly clear that DNA oxidation is a major consequence of life in an oxygen-rich environment. Concomitantly, survival in the presence of oxygen, with the constant threat of deleterious DNA mutations and deletions, has largely been made possible through the evolution of a vast array of DNA repair enzymes. The articles in this Oxidatively Damaged DNA & Repair special issue detail the reactions by which intracellular DNA is oxidatively damaged, and the enzymatic reactions and pathways by which living organisms survive such assaults by repair processes. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Oxidative Damaged Products, Level of Hydrogen Peroxide, and Antioxidant Protection in Diapausing Pupa of Tasar Silk Worm, Antheraea mylitta: A Comparative Study in Two Voltine Groups.

    PubMed

    Sahoo, Alpana; Dandapat, Jagneshwar; Samanta, Luna

    2015-01-01

    The present study demonstrates tissue-specific (hemolymph and fat body) and inter-voltine [bivoltine (BV) and trivoltine (TV)] differences in oxidatively damaged products, H2O2 content, and the relative level of antioxidant protection in the diapausing pupae of Antheraea mylitta. Results suggest that fat body (FB) of both the voltine groups has oxidative predominance, as evident from the high value of lipid peroxidation and H2O2 content, despite better enzymatic defenses in comparison to hemolymph (HL). This may be attributed to the higher metabolic rate of the tissue concerned, concomitant with high lipid content and abundance of polyunsaturated fatty acids (PUFA). Nondetectable catalase activity in the pupal hemolymph of both strains apparently suggests an additional mechanism for H2O2 metabolism in the tissue. Inter-voltine comparison of the oxidative stress indices and antioxidant defense potential revealed that the TV group has a higher oxidative burden, lower activities for the antioxidant enzymes, and compensatory nonenzymatic protection from reduced glutathione and ascorbic acid.

  9. Immunochemical detection of oxidatively damaged DNA.

    PubMed

    Rossner, Pavel; Sram, Radim J

    2012-04-01

    Oxidatively damaged DNA is implicated in various diseases, including neurodegenerative disorders, cancer, diabetes, cardiovascular and inflammatory diseases as well as aging. Several methods have been developed to detect oxidatively damaged DNA. They include chromatographic techniques, the Comet assay, (32)P-postlabelling and immunochemical methods that use antibodies to detect oxidized lesions. In this review, we discuss the detection of 8-oxo-7,8-dihydro-29-deoxyguanosine (8-oxodG), the most abundant oxidized nucleoside. This lesion is frequently used as a marker of exposure to oxidants, including environmental pollutants, as well as a potential marker of disease progression. We concentrate on studies published between the years 2000 and 2011 that used enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry to detect 8-oxodG in humans, laboratory animals and in cell lines. Oxidative damage observed in these organisms resulted from disease, exposure to environmental pollutants or from in vitro treatment with various chemical and physical factors.

  10. Oxidative and alkylating damage in DNA.

    PubMed

    Martinez, Glaucia R; Loureiro, Ana Paula M; Marques, Sabrina A; Miyamoto, Sayuri; Yamaguchi, Lydia F; Onuki, Janice; Almeida, Eduardo A; Garcia, Camila C M; Barbosa, Lívea F; Medeiros, Marisa H G; Di Mascio, Paolo

    2003-11-01

    Modification of cellular DNA upon exposure to reactive oxygen and nitrogen species is the likely initial event involved in the induction of the mutagenic and lethal effects of various oxidative stress agents. Evidence has been accumulated for the significant implication of singlet oxygen (1O(2)), generated as the result of UVA activation of endogenous photosensitizers as porphyrins and flavins. 7,8-Dihydro-8-oxo-2'-deoxyguanosine (8-oxodGuo) has been shown to be the exclusive product of the reaction of 1O(2) with the guanine moiety of cellular DNA, in contrast to the hydroxyl radical, which reacts almost indifferently with all the nucleobases and the sugar moiety of DNA. Furthermore 8-oxodGuo is also produced by other oxidants and can be used as an ubiquitous biomarker of DNA oxidation but can not be a specific marker of any particular species. The role of DNA etheno adducts in mutagenic and carcinogenic processes triggered by known occupational and environmental carcinogens has also been studied. Much interest in etheno adducts resulted from the detection of increased levels of 1,N(6)-etheno-2'-deoxyadenosine and 3,N(4)-etheno-2'-deoxycytidine in DNA from human, rat and mouse tissues under pathophysiological conditions associated with oxidative stress. A method involving on-line HPLC with electrospray tandem mass spectrometry detection has been developed for the analysis of 1,N(2)-etheno-2'-deoxyguanosine (1,N(2)-epsilondGuo) in DNA. This methodology permits direct quantification of 20 fmol (7.4 adducts/10(8) dGuo) of the etheno adduct from approximately 350 microg of crude DNA hydrolysates. This method provides the first evidence of the occurrence of 1,N(2)-epsilondGuo as a basal endogenous lesion and may be utilized to better assess the biological consequences of etheno DNA damage under normal and pathological conditions. This work addresses the importance of isotope labeling associated with mass spectrometry technique for biomolecule damage studies.

  11. Synthesis of damaged DNA containing the oxidative lesion 3'-oxothymidine.

    PubMed

    Bedi, Mel F; Li, Weiye; Gutwald, Taylor; Bryant-Friedrich, Amanda C

    2017-09-01

    Oxidative events that take place during regular oxygen metabolism can lead to the formation of organic or inorganic radicals. The interaction of these radicals with macromolecules in the organism and with DNA in particular is suspected to lead to apoptosis, DNA lesions and cell damage. Independent generation of DNA lesions resulting from oxidative damage is used to promote the study of their effects on biological systems. An efficient synthesis of oligodeoxyribonucleotides (ODNs) containing the oxidative damage lesion 3'-oxothymidine has been accomplished via incorporation of C3'-hydroxymethyl thymidine as its corresponding 5'-phosphoramidite. Through oxidative cleavage using sodium periodate in aqueous solution, the lesion of interest is easily generated. Due to its inherent instability it cannot be directly isolated, but must be generated in situ. 3'-Oxothymidine is a demonstrated damage product formed upon generation of the C3'-thymidinyl radical in ODN. Copyright © 2017. Published by Elsevier Ltd.

  12. Puerarin ameliorates heat stress-induced oxidative damage and apoptosis in bovine Sertoli cells by suppressing ROS production and upregulating Hsp72 expression.

    PubMed

    Cong, Xia; Zhang, Qian; Li, Huatao; Jiang, Zhongling; Cao, Rongfeng; Gao, Shansong; Tian, Wenru

    2017-01-15

    Puerarin, a bioactive isoflavone glucoside extracted from radix Puerariae, has been proven to possess many biological activities. However, the role of puerarin in protecting bovine Sertoli cells (bSCs) under heat stress conditions remains to be clarified. The present study aimed to explore the possible protective mechanism of puerarin for primary cultured bSCs subjected to heat stress. Bovine Sertoli cells were treated with 15 μM of puerarin before they were exposed to 42 °C for 1 hour. The dose of puerarin (15 μM) was determined on the basis of cell viability. The results showed that puerarin treatment suppressed the production of reactive oxygen species and decreased the oxidative damage of the bSCs subjected to heat stress, as indicated by changes in superoxide dismutase, catalase, and glutathione peroxidase activities and malondialdehyde content. Moreover, puerarin treatment also suppressed the initiation of mitochondria-dependent apoptotic pathway, as revealed by changes in Bax to Bcl-2 ratio, mitochondrial membrane potential, cytochrome C release, caspase-3 activation, and apoptotic rate compared with the heat stress group. In addition, puerarin treatment increased Hsp72 expression in the bSCs with no apparent cellular cytotoxicity compared with the control group. Furthermore, increased Hsp72 was detected in the heat stress plus puerarin group compared with the heat stress group. In conclusion, puerarin attenuates heat stress-induced oxidative damage and apoptosis of bSCs by suppressing reactive oxygen species production and upregulating Hsp72 expression.

  13. Oxidative cell damage in Kat-sod assay of oxyhalides as inorganic disinfection by-products and their occurrence by ozonation.

    PubMed

    Ueno, H; Oishi, K; Sayato, Y; Nakamuro, K

    2000-01-01

    Nine oxyhalides as possible inorganic disinfection by-products were tested for oxidative cell damage by Kat-sod assay with E. coli mutant strains deficient in the active oxygen-scavenging enzymes. Chlorine dioxide, chlorite, and iodate were highly cytotoxic, whereas in the presence of cysteine, bromate (BrO3-) and metaperiodate (IO4-) showed more growth inhibition toward the superoxide dismutase-deficient strains than the wild strain. BrO3- also showed oxidative mutagenicity with cysteine or glutathione ethyl ester in S. typhimurium TA 100. To identify oxyhalides formed by ozonation of raw water containing sea water, the occurrence of ozonation by-products of bromide and iodide was investigated. The results indicate that BrO3- is toxicologically one of the most remarkable oxyhalides detectable in drinking water because IO4- was not detected in the ozonated solution of iodide, and the ozonation condition to lower BrO3- is to keep it neutral in the presence of ammonium ion.

  14. Oxidative stress and oxidative damage in chemical carcinogenesis

    SciTech Connect

    Klaunig, James E. Wang Zemin; Pu Xinzhu; Zhou Shaoyu

    2011-07-15

    Reactive oxygen species (ROS) are induced through a variety of endogenous and exogenous sources. Overwhelming of antioxidant and DNA repair mechanisms in the cell by ROS may result in oxidative stress and oxidative damage to the cell. This resulting oxidative stress can damage critical cellular macromolecules and/or modulate gene expression pathways. Cancer induction by chemical and physical agents involves a multi-step process. This process includes multiple molecular and cellular events to transform a normal cell to a malignant neoplastic cell. Oxidative damage resulting from ROS generation can participate in all stages of the cancer process. An association of ROS generation and human cancer induction has been shown. It appears that oxidative stress may both cause as well as modify the cancer process. Recently association between polymorphisms in oxidative DNA repair genes and antioxidant genes (single nucleotide polymorphisms) and human cancer susceptibility has been shown.

  15. Quercitrin protects skin from UVB-induced oxidative damage

    SciTech Connect

    Yin, Yuanqin; Li, Wenqi; Son, Young-Ok; Sun, Lijuan; Lu, Jian; Kim, Donghern; Wang, Xin; Yao, Hua; Wang, Lei; Pratheeshkumar, Poyil; Hitron, Andrew J.; Luo, Jia; Gao, Ning; Shi, Xianglin; Zhang, Zhuo

    2013-06-01

    Exposure of the skin to ultraviolet B (UVB) radiation causes oxidative damage to skin, resulting in sunburn, photoaging, and skin cancer. It is generally believed that the skin damage induced by UV irradiation is a consequence of generation of reactive oxygen species (ROS). Recently, there is an increased interest in the use of natural products as chemopreventive agents for non-melanoma skin cancer (NMSC) due to their antioxidants and anti-inflammatory properties. Quercitrin, glycosylated form of quercetin, is the most common flavonoid in nature with antioxidant properties. The present study investigated the possible beneficial effects of quercitrin to inhibit UVB irradiation-induced oxidative damage in vitro and in vivo. Our results showed that quercitrin decreased ROS generation induced by UVB irradiation in JB6 cells. Quercitrin restored catalase expression and GSH/GSSG ratio reduced by UVB exposure, two major antioxidant enzymes, leading to reductions of oxidative DNA damage and apoptosis and protection of the skin from inflammation caused by UVB exposure. The present study demonstrated that quercitrin functions as an antioxidant against UVB irradiation-induced oxidative damage to skin. - Highlights: • Oxidative stress plays a key role in UV-induced cell and tissue injuries. • Quercitrin decreases ROS generation and restores antioxidants irradiated by UVB. • Quercitrin reduces UVB-irradiated oxidative DNA damage, apoptosis, and inflammation. • Quercitrin functions as an antioxidant against UVB-induced skin injuries.

  16. Damage of lipopolysaccharides in outer cell membrane and production of ROS-mediated stress within bacteria makes nano zinc oxide a bactericidal agent

    NASA Astrophysics Data System (ADS)

    Patra, Prasun; Roy, Shuvrodeb; Sarkar, Sampad; Mitra, Shouvik; Pradhan, Saheli; Debnath, Nitai; Goswami, Arunava

    2014-12-01

    Zinc oxide nanoparticle (ZNP) has been synthesized by microwave-assisted technique with the aid of a buffer solution. ZNP inhibited the growth of bacterial system Escherichia coli, even its multidrug-resistant counterpart as well. Systematic evaluation reveals that bioavailable crystalline ZNP damages the lipopolysaccharide layer from outer membrane (OM) of E. coli, subsequently damages the OM followed by inner membrane, enters within the cell and generates extensive reactive oxygen species-mediated damage. A series of biochemical, biophysical and molecular techniques have been used to reach the conclusion. We believe this work is expected to enlighten the detailed mode of action study in bacterial system.

  17. Wheat peptides reduce oxidative stress and inhibit NO production through modulating μ-opioid receptor in a rat NSAID-induced stomach damage model.

    PubMed

    Yin, Hong; Cai, Hui-Zhen; Wang, Shao-Kang; Yang, Li-Gang; Sun, Gui-Ju

    2015-01-01

    Non-steroidal anti-inflammatory drugs (NSAIDs) induce tissue damage and oxidative stress in animal models of stomach damage. In the present study, the protective effects of wheat peptides were evaluated in a NSAID-induced stomach damage model in rats. Different doses of wheat peptides or distilled water were administered daily by gavage for 30 days before the rat stomach damage model was established by administration of NSAIDs (aspirin and indomethacin) into the digestive tract twice. The treatment of wheat peptides decreased the NSAID-induced gastric epithelial cell degeneration and oxidative stress and NO levels in the rats. Wheat peptides significantly increased the superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities and decreased iNOS activity in stomach. The mRNA expression level of μ-opioid receptor was significantly decreased in wheat peptides-treated rats than that in in the control rats. The results suggest that NSAID drugs induced stomach damage in rats, wchih can be prevented by wheat peptides. The mechanisms for the protective effects were most likely through reducing NSAID-induced oxidative stress. Copyright © 2015 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

  18. Electron beam damage in oxides: a review.

    PubMed

    Jiang, Nan

    2016-01-01

    This review summarizes a variety of beam damage phenomena relating to oxides in (scanning) transmission electron microscopes, and underlines the shortcomings of currently popular mechanisms. These phenomena include mass loss, valence state reduction, phase decomposition, precipitation, gas bubble formation, phase transformation, amorphization and crystallization. Moreover, beam damage is also dependent on specimen thickness, specimen orientation, beam voltage, beam current density and beam size. This article incorporates all of these damage phenomena and experimental dependences into a general description, interpreted by a unified mechanism of damage by induced electric field. The induced electric field is produced by positive charges, which are generated from excitation and ionization. The distribution of the induced electric fields inside a specimen is beam-illumination- and specimen-shape- dependent, and associated with the experimental dependence of beam damage. Broadly speaking, the mechanism operates differently in two types of material. In type I, damage increases the resistivity of the irradiated materials, and is thus divergent, resulting in phase separation. In type II, damage reduces the resistivity of the irradiated materials, and is thus convergent, resulting in phase transformation. Damage by this mechanism is dependent on electron-beam current density. The two experimental thresholds are current density and irradiation time. The mechanism comes into effect when these thresholds are exceeded, below which the conventional mechanisms of knock-on and radiolysis still dominate.

  19. Potential role of punicalagin against oxidative stress induced testicular damage

    PubMed Central

    Rao, Faiza; Tian, Hui; Li, Wenqing; Hung, Helong; Sun, Fei

    2016-01-01

    Punicalagin is isolated from pomegranate and widely used for the treatment of different diseases in Chinese traditional medicine. This study aimed to evaluate the effect of Punicalagin (purity ≥98%) on oxidative stress induced testicular damage and its effect on fertility. We detected the antioxidant potential of punicalagin in lipopolysaccharide (LPS) induced oxidative stress damage in testes, also tried to uncover the boosting fertility effect of Punicalagin (PU) against oxidative stress-induced infertility. Results demonstrated that 9 mg kg−1 for 7 days treatment significantly decreases LPS induced oxidative damage in testes and nitric oxide production. The administration of oxidative stress resulted in a significant reduction in testes antioxidants GSH, T-SOD, and CAT raised LPO, but treatment with punicalagin for 7 days increased antioxidant defense GSH, T-SOD, and CAT by the end of the experiment and reduced LPO level as well. PU also significantly activates Nrf2, which is involved in regulation of antioxidant defense systems. Hence, the present research categorically elucidates the protective effect of punicalagin against LPS induced oxidative stress induced perturbation in the process of spermatogenesis and significantly increased sperm health and number. Moreover, fertility success significantly decreased in LPS-injected mice compared to controls. Mice injected with LPS had fertility indices of 12.5%, while others treated with a combination of PU + LPS exhibited 75% indices. By promoting fertility and eliminating oxidative stress and inflammation, PU may be a useful nutrient for the treatment of infertility. PMID:26763544

  20. Potential role of punicalagin against oxidative stress induced testicular damage.

    PubMed

    Rao, Faiza; Tian, Hui; Li, Wenqing; Hung, Helong; Sun, Fei

    2016-01-01

    Punicalagin is isolated from pomegranate and widely used for the treatment of different diseases in Chinese traditional medicine. This study aimed to evaluate the effect of Punicalagin (purity ≥98%) on oxidative stress induced testicular damage and its effect on fertility. We detected the antioxidant potential of punicalagin in lipopolysaccharide (LPS) induced oxidative stress damage in testes, also tried to uncover the boosting fertility effect of Punicalagin (PU) against oxidative stress-induced infertility. Results demonstrated that 9 mg kg-1 for 7 days treatment significantly decreases LPS induced oxidative damage in testes and nitric oxide production. The administration of oxidative stress resulted in a significant reduction in testes antioxidants GSH, T-SOD, and CAT raised LPO, but treatment with punicalagin for 7 days increased antioxidant defense GSH, T-SOD, and CAT by the end of the experiment and reduced LPO level as well. PU also significantly activates Nrf2, which is involved in regulation of antioxidant defense systems. Hence, the present research categorically elucidates the protective effect of punicalagin against LPS induced oxidative stress induced perturbation in the process of spermatogenesis and significantly increased sperm health and number. Moreover, fertility success significantly decreased in LPS-injected mice compared to controls. Mice injected with LPS had fertility indices of 12.5%, while others treated with a combination of PU + LPS exhibited 75% indices. By promoting fertility and eliminating oxidative stress and inflammation, PU may be a useful nutrient for the treatment of infertility.

  1. The oxidative damage initiation hypothesis for meiosis.

    PubMed

    Hörandl, Elvira; Hadacek, Franz

    2013-12-01

    The maintenance of sexual reproduction in eukaryotes is still a major enigma in evolutionary biology. Meiosis represents the only common feature of sex in all eukaryotic kingdoms, and thus, we regard it a key issue for discussing its function. Almost all asexuality modes maintain meiosis either in a modified form or as an alternative pathway, and facultatively apomictic plants increase frequencies of sexuality relative to apomixis after abiotic stress. On the physiological level, abiotic stress causes oxidative stress. We hypothesize that repair of oxidative damage on nuclear DNA could be a major driving force in the evolution of meiosis. We present a hypothetical model for the possible redox chemistry that underlies the binding of the meiosis-specific protein Spo11 to DNA. During prophase of meiosis I, oxidized sites at the DNA molecule are being targeted by the catalytic tyrosine moieties of Spo11 protein, which acts like an antioxidant reducing the oxidized target. The oxidized tyrosine residues, tyrosyl radicals, attack the phosphodiester bonds of the DNA backbone causing DNA double strand breaks that can be repaired by various mechanisms. Polyploidy in apomictic plants could mitigate oxidative DNA damage and decrease Spo11 activation. Our hypothesis may contribute to explaining various enigmatic phenomena: first, DSB formation outnumbers crossovers and, thus, effective recombination events by far because the target of meiosis may be the removal of oxidative lesions; second, it offers an argument for why expression of sexuality is responsive to stress in many eukaryotes; and third, repair of oxidative DNA damage turns meiosis into an essential characteristic of eukaryotic reproduction.

  2. DNA damage, oxidative mutagen sensitivity, and repair of oxidative DNA damage in nonmelanoma skin cancer patients.

    PubMed

    Bendesky, Andrés; Michel, Alejandra; Sordo, Monserrat; Calderón-Aranda, Emma S; Acosta-Saavedra, Leonor C; Salazar, Ana M; Podoswa, Nancy; Ostrosky-Wegman, Patricia

    2006-08-01

    Nonmelanoma skin cancer (NMSC) is the most frequent type of cancer in humans. Exposure to UV radiation is a major risk factor for NMSC, and oxidative DNA damage, caused either by UV radiation itself or by other agents, may be involved in its induction. Increased sensitivity to oxidative damage and an altered DNA repair capacity (DRC) increase the risk of many types of cancer; however, sensitivity to oxidizing agents has not been evaluated for NMSC, and results regarding DRC in NMSC are inconclusive. In the present study, we evaluated DNA damage and repair in leukocytes from 41 NMSC patients and 45 controls. The Comet assay was used to measure basal and H(2)O(2)-induced DNA damage, as well as the DRC, while the cytokinesis-block micronucleus assay was used to measure the basal level of chromosome damage. Although basal DNA damage was higher for the controls than for the patients, this finding was mainly due to sampling more controls in the summer, which was associated with longer comet tails. In contrast, H(2)O(2)-induced DNA damage was significantly higher in cases than in controls, and this parameter was not influenced by the season of the year. The DRC for the H(2)O(2)-induced damage was similar for cases and controls and unrelated to seasonality. Finally, the frequency of binucleated lymphocytes with micronuclei was similar for cases and controls. The results of this study indicate that NMSC patients are distinguished from controls by an increased sensitivity to oxidative DNA damage.

  3. Combustion products of 1,3-butadiene inhibit catalase activity and induce expression of oxidative DNA damage repair enzymes in human bronchial epithelial cells.

    PubMed

    Kennedy, Christopher H; Catallo, W James; Wilson, Vincent L; Mitchell, James B

    2009-10-01

    1,3-Butadiene, an important petrochemical, is commonly burned off when excess amounts need to be destroyed. This combustion process produces butadiene soot (BDS), which is composed of a complex mixture of polycyclic aromatic hydrocarbons in particulates ranging in size from <1 microm to 1 mm. An organic extract of BDS is both cytotoxic and genotoxic to normal human bronchial epithelial (NHBE) cells. Based on the oxidizing potential of BDS, we hypothesized that an organic extract of this particulate matter would (1) cause enzyme inactivation due to protein amino acid oxidation and (2) induce oxidative DNA damage in NHBE cells. Thus, our aims were to determine the effect of butadiene soot ethanol extract (BSEE) on both enzyme activity and the expression of proteins involved in the repair of oxidative DNA damage. Catalase was found to be sensitive to BDS as catalase activity was potently diminished in the presence of BSEE. Using Western analysis, both the alpha isoform of human 8-oxoguanine DNA glycosylase (alpha-hOGG1) and human apurinic/apyrimidinic endonuclease (APE-1) were shown to be significantly overexpressed as compared to untreated controls after exposure of NHBE cells to BSEE. Our results indicate that BSEE is capable of effectively inactivating the antioxidant enzyme catalase, presumably via oxidation of protein amino acids. The presence of oxidized biomolecules may partially explain the extranuclear fluorescence that is detected when NHBE cells are treated with an organic extract of BDS. Overexpression of both alpha-hOGG1 and APE-1 proteins following treatment of NHBE cells with BSEE suggests that this mixture causes oxidative DNA damage.

  4. Quercitrin protects skin from UVB-induced oxidative damage.

    PubMed

    Yin, Yuanqin; Li, Wenqi; Son, Young-Ok; Sun, Lijuan; Lu, Jian; Kim, Donghern; Wang, Xin; Yao, Hua; Wang, Lei; Pratheeshkumar, Poyil; Hitron, Andrew J; Luo, Jia; Gao, Ning; Shi, Xianglin; Zhang, Zhuo

    2013-06-01

    Exposure of the skin to ultraviolet B (UVB) radiation causes oxidative damage to skin, resulting in sunburn, photoaging, and skin cancer. It is generally believed that the skin damage induced by UV irradiation is a consequence of generation of reactive oxygen species (ROS). Recently, there is an increased interest in the use of natural products as chemopreventive agents for non-melanoma skin cancer (NMSC) due to their antioxidants and anti-inflammatory properties. Quercitrin, glycosylated form of quercetin, is the most common flavonoid in nature with antioxidant properties. The present study investigated the possible beneficial effects of quercitrin to inhibit UVB irradiation-induced oxidative damage in vitro and in vivo. Our results showed that quercitrin decreased ROS generation induced by UVB irradiation in JB6 cells. Quercitrin restored catalase expression and GSH/GSSG ratio reduced by UVB exposure, two major antioxidant enzymes, leading to reductions of oxidative DNA damage and apoptosis and protection of the skin from inflammation caused by UVB exposure. The present study demonstrated that quercitrin functions as an antioxidant against UVB irradiation-induced oxidative damage to skin. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Oxidative Damage in Parkinson’s Disease

    DTIC Science & Technology

    2001-10-01

    of Parkinson’s Disease and the MPTP model of Parkinsonism. In the past year, we have developed a novel column switching assay for measurement of...oxidative damage to DNA in human body fluids. We have applied to this plasma samples of Parkinson’s Disease patients. We have also developed a novel...methodology. We have found a relatively high mutation rate and control samples and intend to apply this to Parkinson’s Disease . We have continued our

  6. Oxidative DNA damage from potassium bromate exposure in Long-Evans rats is not enhanced by a mixture of drinking water disinfection by-products.

    PubMed

    McDorman, Kevin S; Pachkowski, Brian F; Nakamura, Jun; Wolf, Douglas C; Swenberg, James A

    2005-04-15

    Public drinking water treated with chemical disinfectants contains a complex mixture of disinfection by-products (DBPs) for which the relative toxicity of the mixtures needs to be characterized to accurately assess risk. Potassium bromate (KBrO(3)) is a by-product from ozonation of high-bromide surface water for production of drinking water and is a rodent carcinogen that produces thyroid, mesothelial, and renal tumors. The proposed mechanism of KBrO(3) renal carcinogenesis involves the formation of 8-oxoguanine (8-oxoG), a promutagenic base lesion in DNA typically removed through base excision repair (BER). In this study, male Long-Evans rats were exposed via drinking water to carcinogenic concentrations of KBrO(3) (0.4 g/L), 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (0.07 g/L), chloroform (1.8 g/L), bromodichloromethane (0.7 g/L), or a mixture of all these chemicals at the same concentrations for 3 weeks. Half of one kidney was processed for microscopic examination, and the remaining kidney was frozen for isolation of genomic DNA. Levels of 8-oxoG were measured using HPLC with electrochemical detection in DNA samples incubated with formamidopyrimidine-DNA glycosylase. Aldehydic lesions (e.g. abasic sites) in DNA samples were quantitated using an aldehyde-reactive probe slot-blot assay. Treatment with KBrO(3) produced a measurable increase of 8-oxoG in the kidney, and this effect was greater than that produced by treatment with the DBP mixture. No other single chemical treatment caused measurable increases of 8-oxoG. The mixture effect on the amount of 8-oxoG observed in this study suggests an interaction between chemicals that reduced the generation of oxidative DNA damage. No increases in abasic sites were observed with treatment, but a decrease was apparent in the rats treated with the DBP mixture. These data are consistent with previous studies where chronic exposure to this chemical mixture in drinking water resulted in a less than additive

  7. Oxidative and non-oxidative DNA damage and cardiovascular disease.

    PubMed

    Malik, Qudsia; Herbert, Karl E

    2012-04-01

    Evidence for the association of DNA damage with cardiovascular disease has been obtained from in vitro cell culture models, experimental cardiovascular disease and analysis of samples obtained from humans with disease. There is general acceptance that several factors associated with the risk of developing cardiovascular disease cause oxidative damage to DNA in cell culture models with both nuclear and mitochondrial DNA as targets. Moreover, evidence obtained over the past 10 years points to a possible mechanistic role for DNA damage in experimental atherosclerosis culminating in recent studies challenging the assumption that DNA damage is merely a biomarker of the disease process. This kind of mechanistic insight provides a renewed impetus for further studies in this area.

  8. Oxidative DNA damage during sleep periods among nightshift workers.

    PubMed

    Bhatti, Parveen; Mirick, Dana K; Randolph, Timothy W; Gong, Jicheng; Buchanan, Diana Taibi; Zhang, Junfeng Jim; Davis, Scott

    2016-08-01

    Oxidative DNA damage may be increased among nightshift workers because of suppression of melatonin, a cellular antioxidant, and/or inflammation related to sleep disruption. However, oxidative DNA damage has received limited attention in previous studies of nightshift work. From two previous cross-sectional studies, urine samples collected during a night sleep period for 217 dayshift workers and during day and night sleep (on their first day off) periods for 223 nightshift workers were assayed for 8-hydroxydeoxyguanosine (8-OH-dG), a marker of oxidative DNA damage, using high-performance liquid chromatography with electrochemical detection. Urinary measures of 6-sulfatoxymelatonin (aMT6s), a marker of circulating melatonin levels, and actigraphy-based sleep quality data were also available. Nightshift workers during their day sleep periods excreted 83% (p=0.2) and 77% (p=0.03) of the 8-OH-dG that dayshift workers and they themselves, respectively, excreted during their night sleep periods. Among nightshift workers, higher aMT6s levels were associated with higher urinary 8-OH-dG levels, and an inverse U-shaped trend was observed between 8-OH-dG levels and sleep efficiency and sleep duration. Reduced excretion of 8-OH-dG among nightshift workers during day sleep may reflect reduced functioning of DNA repair machinery, which could potentially lead to increased cellular levels of oxidative DNA damage. Melatonin disruption among nightshift workers may be responsible for the observed effect, as melatonin is known to enhance repair of oxidative DNA damage. Quality of sleep may similarly impact DNA repair. Cellular levels of DNA damage will need to be evaluated in future studies to help interpret these findings. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  9. Nitric oxide ameliorates the damaging effects of oxidative stress induced by iron deficiency in cyanobacterium Anabaena 7120.

    PubMed

    Kaushik, Manish Singh; Srivastava, Meenakshi; Srivastava, Alka; Singh, Anumeha; Mishra, Arun Kumar

    2016-11-01

    In cyanobacterium Anabaena 7120, iron deficiency leads to oxidative stress with unavoidable consequences. Nitric oxide reduces pigment damage and supported the growth of Anabaena 7120 in iron-deficient conditions. Elevation in nitric oxide accumulation and reduced superoxide radical production justified the role of nitric oxide in alleviating oxidative stress in iron deficiency. Increased activities of antioxidative enzymes and higher levels of ROS scavengers (ascorbate, glutathione and thiol) in iron deficiency were also observed in the presence of nitric oxide. Nitric oxide also supported the membrane integrity of Anabaena cells and reduces protein and DNA damage caused by oxidative stress induced by iron deficiency. Results suggested that nitric oxide alleviates the damaging effects of oxidative stress induced by iron deficiency in cyanobacterium Anabaena 7120.

  10. Oxidative DNA damage causes mitochondrial genomic instability in Saccharomyces cerevisiae.

    PubMed

    Doudican, Nicole A; Song, Binwei; Shadel, Gerald S; Doetsch, Paul W

    2005-06-01

    Mitochondria contain their own genome, the integrity of which is required for normal cellular energy metabolism. Reactive oxygen species (ROS) produced by normal mitochondrial respiration can damage cellular macromolecules, including mitochondrial DNA (mtDNA), and have been implicated in degenerative diseases, cancer, and aging. We developed strategies to elevate mitochondrial oxidative stress by exposure to antimycin and H(2)O(2) or utilizing mutants lacking mitochondrial superoxide dismutase (sod2Delta). Experiments were conducted with strains compromised in mitochondrial base excision repair (ntg1Delta) and oxidative damage resistance (pif1Delta) in order to delineate the relationship between these pathways. We observed enhanced ROS production, resulting in a direct increase in oxidative mtDNA damage and mutagenesis. Repair-deficient mutants exposed to oxidative stress conditions exhibited profound genomic instability. Elimination of Ntg1p and Pif1p resulted in a synergistic corruption of respiratory competency upon exposure to antimycin and H(2)O(2). Mitochondrial genomic integrity was substantially compromised in ntg1Delta pif1Delta sod2Delta strains, since these cells exhibit a total loss of mtDNA. A stable respiration-defective strain, possessing a normal complement of mtDNA damage resistance pathways, exhibited a complete loss of mtDNA upon exposure to antimycin and H(2)O(2). This loss was preventable by Sod2p overexpression. These results provide direct evidence that oxidative mtDNA damage can be a major contributor to mitochondrial genomic instability and demonstrate cooperation of Ntg1p and Pif1p to resist the introduction of lesions into the mitochondrial genome.

  11. Mitochondria are the main target for oxidative damage in leaves of wheat (Triticum aestivum L.).

    PubMed

    Bartoli, Carlos Guillermo; Gómez, Facundo; Martínez, Dana Ethel; Guiamet, Juan José

    2004-08-01

    Photosynthesis, respiration, and other processes produce reactive oxygen species (ROS) that can cause oxidative modifications to proteins, lipids, and DNA. The production of ROS increases under stress conditions, causing oxidative damage and impairment of normal metabolism. In this work, oxidative damage to various subcellular compartments (i.e. chloroplasts, mitochondria, and peroxisomes) was studied in two cultivars of wheat differing in ascorbic acid content, and growing under good irrigation or drought. In well-watered plants, mitochondria contained 9-28-fold higher concentrations of oxidatively modified proteins than chloroplasts or peroxisomes. In general, oxidative damage to proteins was more intense in the cultivar with the lower content of ascorbic acid, particularly in the chloroplast stroma. Water stress caused a marked increase in oxidative damage to proteins, particularly in mitochondria and peroxisomes. These results indicate that mitochondria are the main target for oxidative damage to proteins under well-irrigated and drought conditions.

  12. Profiling oxidative DNA damage: effects of antioxidants.

    PubMed

    Box, Harold C; Patrzyc, Helen B; Budzinski, Edwin E; Dawidzik, Jean B; Freund, Harold G; Zeitouni, Nathalie C; Mahoney, Martin C

    2012-11-01

    The goal of this research was to determine whether antioxidant usage could be correlated with changes in DNA damage levels. Liquid Chromatography-tandem Mass Spectrometry (LC-MS/MS) was used to simultaneously measure five different oxidatively-induced base modifications in the DNA of WBC. Measurements of the five modifications were made before and after an 8-week trial during which participants took the SU.VI.MAX supplement. Levels of the five DNA modifications were compared among different groupings: users versus non-users of antioxidant supplements, before versus after the supplement intervention and men versus women. The statistical significance of differences between groups was most significant for pyrimidine base modifications and the observed trends reflect trends reported in epidemiological studies of antioxidant usage. A combination of modifications derived from pyrimidine bases is suggested as a superior indicator of oxidative stress.

  13. Dehydroepiandrosterone ameliorates H2O2-induced Leydig cells oxidation damage and apoptosis through inhibition of ROS production and activation of PI3K/Akt pathways.

    PubMed

    Ding, Xiao; Wang, Dian; Li, Longlong; Ma, Haitian

    2016-01-01

    Dehydroepiandrosterone (DHEA) is widely used as a nutritional supplement, and administration of DHEA produces a number of beneficial effects in the elderly. Many researchers have suggested that DHEA exerts it function after conversion into more biologically active hormones in peripheral target cells. The actions of DHEA in Leydig cells, a major target cell of DHEA biotransformation in males, are not clear. The present study found that DHEA increased cell viability and decreased reactive oxygen species (ROS) and malondialdehyde contents in H2O2-induced Leydig cells. DHEA significantly increased the activities of superoxide dismutase, catalase and peroxidase, and decreased the DNA damage in H2O2-induced Leydig cells. Apoptosis was significant decreased in H2O2-induced Leydig cells after DHEA treatment. DHEA inhibited the loss of mitochondrial membrane potential (ΔΨm) and the upregulation of the caspase-3 protein level induced by H2O2 in Leydig cells. DHEA also reversed the decrease in PI3K and p-Akt protein levels induced by H2O2. These data showed that DHEA could ameliorate H2O2-induced oxidative damage by increasing anti-oxidative enzyme activities, which resulted in reduced ROS content, and decreased apoptosis, mainly by preventing the loss of ΔΨm and inhibiting caspase-3 protein levels via activation of PI3K/Akt signaling pathways. These results increase our understanding of the molecular mechanism of the anti-ageing effect of DHEA.

  14. Reformulated meat products protect against ischemia-induced cardiac damage.

    PubMed

    Asensio-Lopez, M C; Lax, A; Sanchez-Mas, J; Avellaneda, A; Planes, J; Pascual-Figal, D A

    2016-02-01

    The protective effects of the antioxidants present in food are of great relevance for cardiovascular health. This study evaluates whether the extracts from reformulated meat products with a reduction in fat and/or sodium content exert a cardioprotective effect against ischemia-induced oxidative stress in cardiomyocytes, compared with non-meat foods. Ischemic damage caused loss of cell viability, increased reactive oxygen species and lipid peroxidation and decreased the antioxidant activity. Pretreatment for 24 h with digested or non-digested extracts from reformulated meat products led to protection against ischemia-induced oxidative damage: increased cell viability, reduced oxidative stress and restored the antioxidant activity. Similar results were obtained using extracts from tuna fish, but not with the extracts of green peas, salad or white beans. These results suggest that reformulated meat products have a beneficial impact in protecting cardiac cells against ischemia, and they may represent a source of natural antioxidants with benefits for cardiovascular health.

  15. Acrylonitrile-induced oxidative DNA damage in rat astrocytes.

    PubMed

    Pu, Xinzhu; Kamendulis, Lisa M; Klaunig, James E

    2006-10-01

    Chronic administration of acrylonitrile results in a dose-related increase in astrocytomas in rat brain, but the mechanism of acrylonitrile carcinogenicity is not fully understood. The potential of acrylonitrile or its metabolites to induce direct DNA damage as a mechanism for acrylonitrile carcinogenicity has been questioned, and recent studies indicate that the mechanism involves the induction of oxidative stress in rat brain. The present study examined the ability of acrylonitrile to induce DNA damage in the DI TNC1 rat astrocyte cell line using the alkaline Comet assay. Oxidized DNA damage also was evaluated using formamidopyrimidine DNA glycosylase treatment in the modified Comet assay. No increase in direct DNA damage was seen in astrocytes exposed to sublethal concentrations of acrylonitrile (0-1.0 mM) for 24 hr. However, acrylonitrile treatment resulted in a concentration-related increase in oxidative DNA damage after 24 hr. Antioxidant supplementation in the culture media (alpha-tocopherol, (-)-epigallocathechin-3 gallate, or trolox) reduced acrylonitrile-induced oxidative DNA damage. Depletion of glutathione using 0.1 mM DL-buthionine-[S,R]-sulfoximine increased acrylonitrile-induced oxidative DNA damage (22-46%), while cotreatment of acrylonitrile with 2.5 mM L-2-oxothiazolidine-4-carboxylic acid, a precursor for glutathione biosynthesis, significantly reduced acrylonitrile-induced oxidative DNA damage (7-47%). Cotreatment of acrylonitrile with 0.5 mM 1-aminobenzotriazole, a suicidal inhibitor of cytochrome P450, prevented the oxidative DNA damage produced by acrylonitrile. Cyanide (0.1-0.5 mM) increased oxidative DNA damage (44-160%) in astrocytes. These studies demonstrate that while acrylonitrile does not directly damage astrocyte DNA, it does increase oxidative DNA damage. The oxidative DNA damage following acrylonitrile exposure appears to arise mainly through the P450 metabolic pathway; moreover, glutathione depletion may contribute to the

  16. DNA damage in Fabry patients: An investigation of oxidative damage and repair.

    PubMed

    Biancini, Giovana Brondani; Moura, Dinara Jaqueline; Manini, Paula Regina; Faverzani, Jéssica Lamberty; Netto, Cristina Brinckmann Oliveira; Deon, Marion; Giugliani, Roberto; Saffi, Jenifer; Vargas, Carmen Regla

    2015-06-01

    Fabry disease (FD) is a lysosomal storage disorder associated with loss of activity of the enzyme α-galactosidase A. In addition to accumulation of α-galactosidase A substrates, other mechanisms may be involved in FD pathophysiology, such as inflammation and oxidative stress. Higher levels of oxidative damage to proteins and lipids in Fabry patients were previously reported. However, DNA damage by oxidative species in FD has not yet been studied. We investigated basal DNA damage, oxidative DNA damage, DNA repair capacity, and reactive species generation in Fabry patients and controls. To measure oxidative damage to purines and pyrimidines, the alkaline version of the comet assay was used with two endonucleases, formamidopyrimidine DNA-glycosylase (FPG) and endonuclease III (EndoIII). To evaluate DNA repair, a challenge assay with hydrogen peroxide was performed. Patients presented significantly higher levels of basal DNA damage and oxidative damage to purines. Oxidative DNA damage was induced in both DNA bases by H2O2 in patients. Fabry patients presented efficient DNA repair in both assays (with and without endonucleases) as well as significantly higher levels of oxidative species (measured by dichlorofluorescein content). Even if DNA repair be induced in Fabry patients (as a consequence of continuous exposure to oxidative species), the repair is not sufficient to reduce DNA damage to control levels.

  17. Transgenic Mouse Model for Reducing Oxidative Damage in Bone

    NASA Technical Reports Server (NTRS)

    Schreurs, Ann-Sofie; Torres, S.; Truong, T.; Moyer, E. L.; Kumar, A.; Tahimic, Candice C. G.; Alwood, J. S.; Limoli, C. L.; Globus, R. K.

    2016-01-01

    Bone loss can occur due to many challenges such age, radiation, microgravity, and Reactive Oxygen Species (ROS) play a critical role in bone resorption by osteoclasts (Bartell et al. 2014). We hypothesize that suppression of excess ROS in skeletal cells, both osteoblasts and osteoclasts, regulates skeletal growth and remodeling. To test our hypothesis, we used transgenic mCAT mice which overexpress the human anti-oxidant catalase gene targeted to the mitochondria, the main site for endogenous ROS production. mCAT mice have a longer life-span than wildtype controls and have been used to study various age-related disorders. To stimulate remodeling, 16 week old mCAT mice or wildtype mice were exposed to treatment (hindlimb-unloading and total body-irradiation) or sham treatment conditions (control). Tissues were harvested 2 weeks later for skeletal analysis (microcomputed tomography), biochemical analysis (gene expression and oxidative damage measurements), and ex vivo bone marrow derived cell culture (osteoblastogenesis and osteoclastogenesis). mCAT mice expressed the transgene and displayed elevated catalase activity in skeletal tissue and marrow-derived osteoblasts and osteoclasts grown ex vivo. In addition, when challenged with treatment, bone tissues from wildtype mice showed elevated levels of malondialdehyde (MDA), indicating oxidative damage) whereas mCAT mice did not. Correlation analysis revealed that increased catalase activity significantly correlated with decreased MDA levels and that increased oxidative damage correlated with decreased percent bone volume (BVTV). In addition, ex-vivo cultured osteoblast colony growth correlated with catalase activity in the osteoblasts. Thus, we showed that these transgenic mice can be used as a model to study the relationship between markers of oxidative damage and skeletal properties. mCAT mice displayed reduced BVTV and trabecular number relative to wildtype mice, as well as increased structural model index in the

  18. Prevention of oxidative DNA damage in rats by brussels sprouts.

    PubMed

    Deng, X S; Tuo, J; Poulsen, H E; Loft, S

    1998-03-01

    The alleged cancer preventive effects of cruciferous vegetables could be related to protection from mutagenic oxidative DNA damage. We have studied the effects of Brussels sprouts, some non-cruciferous vegetables and isolated glucosinolates on spontaneous and induced oxidative DNA damage in terms of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) in groups of 6-8 male Wistar rats. Excess oxidative DNA damage was induced by 2-nitropropane (2-NP 100 mg/kg). Four days oral administration of 3 g of cooked Brussels sprouts homogenate reduced the spontaneous urinary 8-oxodG excretion by 31% (p<0.05) whereas raw sprouts, beans and endive (1:1), isolated indolyl glucosinolates and breakdown products had no significant effect. An aqueous extract of cooked Brussels sprouts (corresponding to 6.7 g vegetable per day for 4 days) decreased the spontaneous 8-oxodG excretion from 92 +/- 12 to 52 +/- 15 pmol/24 h (p<0.05). After 2-NP administration the 8-oxodG excretion was increased to 132 +/- 26 pmol/24 h (p<0.05) whereas pretreatment with the sprouts extract reduced this to 102 +/- 30 pmol/24 h (p<0.05). The spontaneous level of 8-oxodG in nuclear DNA from liver and bone marrow was not significantly affected by the sprouts extract whereas the level decreased by 27% in the kidney (p<0.05). In the liver 2-NP increased the 8-oxodG levels in nuclear DNA 8.7 and 3.8 times (p<0.05) 6 and 24 h after dose, respectively. The sprouts extract reduced this increase by 57% (p<0.05) at 6 h whereas there was no significant effect at 24 h. In the kidneys 2-NP increased the 8-oxodG levels 2.2 and 1.2 times (p<0.05) 6 and 24 h after dose, respectively. Pretreatment with the sprouts extract abolished these increases (p<0.05). Similarly, in the bone marrow the extract protected completely (p<0.05) against a 4.9-fold 2-NP induced increase (p<0.05) in the 8-oxodG level. These findings demonstrate that cooked Brussels sprouts contain bioactive substance(s) with a potential for reducing the physiological

  19. Type-dependent oxidative damage in frontotemporal lobar degeneration: cortical astrocytes are targets of oxidative damage.

    PubMed

    Martínez, Anna; Carmona, Margarita; Portero-Otin, Manuel; Naudí, Alba; Pamplona, Reinald; Ferrer, Isidre

    2008-12-01

    Oxidative injury and stress responses are common features of many neurodegenerative diseases. To assess oxidative stress responses in frontotemporal lobar degeneration (FTLD), we identified increased 4-hydroxynonenal (HNE) adducts using gel electrophoresis and Western blotting in frontal cortex samples in 6 of 6 cases of FTLD with the P301L mutation in the tau gene (FTLD-tau), in 3 of 10 cases with tau-negative ubiquitin-immunoreactive inclusions, and in 2 of 3 cases associated with motor neuron disease. Selectively increased lipoxidation-derived protein damage associated with altered membrane unsaturation and fatty acid profiles was verified by mass spectrometry in FTLD-tau and FTLD associated with motor neuron disease. All FTLD-tau and most cases with increased HNE-positive bands had marked astrocytosis as determined by glial fibrillary acidic protein (GFAP) immunohistochemistry and increased GFAP expression on Western blotting; 2 FTLD cases with tau-negative ubiquitin-immunoreactive inclusions and with increased GFAP expression did not have increased HNE adducts. Bidimensional gel electrophoresis, Western blotting, in-gel digestion, and mass spectrometry identified GFAP as a major target of lipoxidation in all positive cases; confocal microscopy revealed colocalization of HNE and GFAP in cortical astrocytes, superoxide dismutase 1 in astrocytes, and superoxide dismutase 2 in astrocytes and neurons in all FTLD types. Thus, in FTLD, there is variable disease-dependent oxidative damage that is prominent in FTLD-tau, astrocytes are targets of oxidative damage, and GFAP is a target of lipoxidation. Astrocytes are, therefore, crucial elements of oxidative stress responses in FTLD.

  20. OXIDANT CONDITIONING PROTECTS CARTILAGE FROM MECHANICALLY-INDUCED DAMAGE

    PubMed Central

    Ramakrishnan, Prem; Hecht, Benjamin; Pedersen, Doug; Lavery, Matthew; Maynard, Jerry; Buckwalter, Joseph; Martin, James

    2013-01-01

    Articular cartilage degeneration in osteoarthritis has been linked to abnormal mechanical stresses that are known to cause chondrocyte apoptosis and metabolic derangement in in vitro models. Evidence implicating oxidative damage as the immediate cause of these harmful effects suggests that the anti-oxidant defenses of chondrocytes might influence their tolerance for mechanical injury. Based on evidence that anti-oxidant defenses in many cell types are stimulated by moderate oxidant exposure, we hypothesized that oxidant pre-conditioning would reduce acute chondrocyte death and proteoglycan depletion in cartilage explants after exposure to abnormal mechanical stresses. Porcine cartilage explants were treated every 48 hours with tert-butyl hydrogen peroxide (tBHP) at non-lethal concentrations (25, 100, 250, 500 µM) for a varying number of times (1, 2 or 4) prior to a bout of unconfined axial compression (5 MPa, 1 Hz, 1800 cycles). When compared with untreated controls, tBHP had significant positive effects on post-compression viability, lactate production, and proteoglycan losses. Overall, the most effective regime was 100 µM tBHP applied 4 times. RNA analysis revealed significant effects of 100 µM tBHP on gene expression. Catalase, hypoxia-inducible factor-1alpha (HIF-1α), and glyceraldehyde 6-phosphate dehydrogenase (GAPDH) were significantly increased relative to untreated controls in explants treated 4 times with 100 µM tBHP, a regime that also resulted in a significant decrease in matrix metalloproteinase-3 (MMP-3) expression. These findings demonstrate that repeated exposure of cartilage to sub-lethal concentrations of peroxide can moderate the acute effects of mechanical stress, a conclusion supported by evidence of peroxide-induced changes in gene expression that could render chondrocytes more resistant to oxidative damage. PMID:20058262

  1. Sperm DNA oxidative damage and DNA adducts

    PubMed Central

    Jeng, Hueiwang Anna; Pan, Chih-Hong; Chao, Mu-Rong; Lin, Wen-Yi

    2015-01-01

    The objective of this study was to investigate DNA damage and adducts in sperm from coke oven workers who have been exposed to polycyclic aromatic hydrocarbons. A longitudinal study was conducted with repeated measurements during spermatogenesis. Coke-oven workers (n=112) from a coke-oven plant served the PAH-exposed group, while administrators and security personnel (n=67) served the control. Routine semen parameters (concentration, motility, vitality, and morphology) were analyzed simultaneously; the assessment of sperm DNA integrity endpoints included DNA fragmentation, bulky DNA adducts, and 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxo-dGuo). The degree of sperm DNA fragmentation was measured using the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay and sperm chromatin structure assay (SCSA). The PAH-exposed group had a significant increase in bulky DNA adducts and 8-oxo-dGuo compared to the control subjects (Ps = 0.002 and 0.045, respectively). Coke oven workers' percentages of DNA fragmentation and denaturation from the PAH-exposed group were not significantly different from those of the control subjects (Ps = 0.232 and 0.245, respectively). Routine semen parameters and DNA integrity endpoints were not correlated. Concentrations of 8-oxo-dGuo were positively correlated with percentages of DNA fragmentation measured by both TUNEL and SCSA (Ps = 0.045 and 0.034, respectively). However, the concentrations of 8-oxo-dGuo and percentages of DNA fragmentation did not correlate with concentrations of bulky DNA adducts. In summary, coke oven workers with chronic exposure to PAHs experienced decreased sperm DNA integrity. Oxidative stress could contribute to the degree of DNA fragmentation. Bulky DNA adducts may be independent of the formation of DNA fragmentation and oxidative adducts in sperm. Monitoring sperm DNA integrity is recommended as a part of the process of assessing the impact of occupational and environmental toxins on

  2. Microsomal oxidative damage promoted by acetaminophen metabolism.

    PubMed

    Letelier, María Eugenia; López-Valladares, Miguel; Peredo-Silva, Liliana; Rojas-Sepúlveda, Daniel; Aracena, Paula

    2011-10-01

    Adverse reactions of acetaminophen have been associated to oxidative stress, which may be elicited by reactive oxygen species (ROS) and/or production of the metabolite NAPQI. Both phenomena would arise through the activity of liver cytochrome P450 (CYP450) system, but their contribution to this oxidative stress is yet to be clarified. A NADPH oxidase activity has been proposed in rat liver microsomes. This activity may be due to the presence of NAD(P)H oxidase (NOX) isoforms in liver endoplasmic reticulum. Both NOX and the CYP450 system activities can catalyze ROS generation using NADPH as a cofactor. Therefore, acetaminophen biotransformation, which requires NADPH, may promote ROS generation through either activity or both. To discriminate between these possibilities, rat liver microsomes were incubated with acetaminophen and NADPH in the presence or absence of specific inhibitors. Incubation with NADPH and acetaminophen elicited lipid peroxidation and decreased thiol content and glutathione-S-transferase (GST) activity. The NOX inhibitors apocynin and plumbagin prevented all these phenomena but the decrease in thiol content. In contrast, this decrease was completely prevented by the specific CYP450 system inhibitor SKF-525A. These data suggest that ROS generation following incubation of microsomes with acetaminophen and NADPH appears to be mainly caused by a NOX activity. In light of these data, toxicity of acetaminophen is discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Black tea extract supplementation decreases oxidative damage in Jurkat T cells.

    PubMed

    Erba, D; Riso, P; Foti, P; Frigerio, F; Criscuoli, F; Testolin, G

    2003-08-15

    The purpose of this study was to investigate the protective effect of black tea (BT) extract against induced oxidative damage in Jurkat T-cell line. Cells supplemented with 10 or 25 mg/L BT were subjected to oxidation with ferrous ions. Malondialdehyde (MDA) production as marker of lipid peroxidation, DNA single strand breaks as marker of DNA damage, and modification of the antioxidant enzyme activity, glutathione peroxidase (GPX) were measured. Results show the efficacy of BT polyphenols to decrease DNA oxidative damage and to affect GPX activity (P<0.05), while no effect was shown on MDA production. The succeeding investigation of the activity of caffeine and epigallocatechin gallate demonstrated their antioxidant potential with respect to the cellular markers evaluated. In conclusion, this study supports the protective effect of BT against ferrous ions induced oxidative damage to DNA and the ability of BT to affect the enzyme antioxidant system of Jurkat cells.

  4. High-Temperature Oxide Regrowth on Mechanically-Damaged Surfaces

    SciTech Connect

    Blau, Peter Julian; Lowe, Tracie M

    2008-01-01

    Here we report the effects of mechanical damage from a sharp stylus on the regrowth of oxide layers on a Ni-based superalloy known as Pyromet 80A . It was found that the oxide that reformed on the damaged portion of a pre-oxidized surface differed from that which formed on undamaged areas after the equal exposures to elevated temperature in air. These findings have broad implications for modeling the processes of material degradation in applications such as exhaust valves in internal combustion engines because they imply that static oxidation data for candidate materials may not adequately reflect their reaction to operating environments that involve both mechanical contact and oxidation.

  5. Oxidative DNA damage during night shift work.

    PubMed

    Bhatti, Parveen; Mirick, Dana K; Randolph, Timothy W; Gong, Jicheng; Buchanan, Diana Taibi; Zhang, Junfeng Jim; Davis, Scott

    2017-09-01

    We previously reported that compared with night sleep, day sleep among shift workers was associated with reduced urinary excretion of 8-hydroxydeoxyguanosine (8-OH-dG), potentially reflecting a reduced ability to repair 8-OH-dG lesions in DNA. We identified the absence of melatonin during day sleep as the likely causative factor. We now investigate whether night work is also associated with reduced urinary excretion of 8-OH-dG. For this cross-sectional study, 50 shift workers with the largest negative differences in night work versus night sleep circulating melatonin levels (measured as 6-sulfatoxymelatonin in urine) were selected from among the 223 shift workers included in our previous study. 8-OH-dG concentrations were measured in stored urine samples using high performance liquid chromatography with electrochemical detection. Mixed effects models were used to compare night work versus night sleep 8-OH-dG levels. Circulating melatonin levels during night work (mean=17.1 ng/mg creatinine/mg creatinine) were much lower than during night sleep (mean=51.7 ng/mg creatinine). In adjusted analyses, average urinary 8-OH-dG levels during the night work period were only 20% of those observed during the night sleep period (95% CI 10% to 30%; p<0.001). This study suggests that night work, relative to night sleep, is associated with reduced repair of 8-OH-dG lesions in DNA and that the effect is likely driven by melatonin suppression occurring during night work relative to night sleep. If confirmed, future studies should evaluate melatonin supplementation as a means to restore oxidative DNA damage repair capacity among shift workers. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  6. Mitochondrial DNA damage and oxidative damage in HL-60 cells exposed to 900MHz radiofrequency fields.

    PubMed

    Sun, Yulong; Zong, Lin; Gao, Zhen; Zhu, Shunxing; Tong, Jian; Cao, Yi

    2017-03-01

    HL-60 cells, derived from human promyelocytic leukemia, were exposed to continuous wave 900MHz radiofrequency fields (RF) at 120μW/cm(2) power intensity for 4h/day for 5 consecutive days to examine whether such exposure is capable damaging the mitochondrial DNA (mtDNA) mediated through the production of reactive oxygen species (ROS). In addition, the effect of RF exposure was examined on 8-hydroxy-2'-dexoyguanosine (8-OHdG) which is a biomarker for oxidative damage and on the mitochondrial synthesis of adenosine triphosphate (ATP) which is the energy required for cellular functions. The results indicated a significant increase in ROS and significant decreases in mitochondrial transcription factor A, mtDNA polymerase gamma, mtDNA transcripts and mtDNA copy number in RF-exposed cells compared with those in sham-exposed control cells. In addition, there was a significant increase in 8-OHdG and a significant decrease in ATP in RF-exposed cells. The response in positive control cells exposed to gamma radiation (GR, which is also known to induce ROS) was similar to those in RF-exposed cells. Thus, the overall data indicated that RF exposure was capable of inducing mtDNA damage mediated through ROS pathway which also induced oxidative damage. Prior-treatment of RF- and GR-exposed the cells with melatonin, a well-known free radical scavenger, reversed the effects observed in RF-exposed cells. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Oxidative damage and redox in Lysosomal Storage Disorders: Biochemical markers.

    PubMed

    Donida, Bruna; Jacques, Carlos Eduardo Diaz; Mescka, Caroline Paula; Rodrigues, Daiane Grigolo Bardemaker; Marchetti, Desirèe Padilha; Ribas, Graziela; Giugliani, Roberto; Vargas, Carmen Regla

    2017-03-01

    Lysosomal Storage Disorders (LSD) comprise a heterogeneous group of >50 genetic disorders caused by mutations in genes that encode lysosomal enzymes, transport proteins or other gene products essential for a functional lysosomal system. As a result, abnormal accumulation of substrates within the lysosome leads to a progressive cellular impairment and dysfunction of numerous organs and systems. The exact mechanisms underlying the pathophysiology of LSD remain obscure. Previous studies proposed a relationship between oxidative stress and the pathogenesis of several inborn errors of metabolism, including LSD. Considering these points, in this paper it was reviewed oxidative stress and emerging antioxidant therapy in LSD, emphasizing studies with biological samples from patients affected by this group of conditions. These studies allow presuming that metabolites accumulated in LSD cause an increase of lysosomes' number and size, which may induce excessive production of reactive species and/or deplete the tissue antioxidant capacity, leading to damage in biomolecules. In vitro and in vivo evidence showed that cell oxidative process occurs in LSD and probably contributes to the pathophysiology of these disorders. In this context, it is possible to suggest that, in the future, antioxidants could come to be used as adjuvant therapy for LSD patients.

  8. Oxidative base damage in RNA detected by reverse transcriptase.

    PubMed Central

    Rhee, Y; Valentine, M R; Termini, J

    1995-01-01

    Oxidative base damage in DNA and metabolic defects in the recognition and removal of such damage play important roles in mutagenesis and human disease. The extent to which cellular RNA is a substrate for oxidative damage and the possible biological consequences of RNA base oxidation, however, remain largely unexplored. Since oxidatively modified RNA may contribute to the high mutability of retroviral genomic DNA, we have been interested in developing methods for the sequence specific detection of such damage. We show here that a primer extension assay using AMV reverse transcriptase (RT) can be used to reveal oxidatively damaged sites in RNA. This finding extends the currently known range of RNA modifications detectable with AMV reverse transcriptase. Analogous assays using DNA polymerases to detect base damage in DNA substrates appear to be restricted to lesions at thymine. Oxidative base damage in the absence of any detectable chain breaks was produced by dye photosensitization of RNA. Six out of 20 dyes examined were capable of producing RT detectable lesions. RT stops were seen predominantly at purines, although many pyrimidine sites were also detected. Dye specific photofootprints revealed by RT analysis suggests differential dye binding to the RNA substrate. Some of the photoreactive dyes described here may have potential utility in RNA structural analysis, particularly in the identification of stem-loop regions in complex RNAs. Images PMID:7545285

  9. Liposomal Antioxidants for Protection against Oxidant-Induced Damage

    PubMed Central

    Suntres, Zacharias E.

    2011-01-01

    Reactive oxygen species (ROS), including superoxide anion, hydrogen peroxide, and hydroxyl radical, can be formed as normal products of aerobic metabolism and can be produced at elevated rates under pathophysiological conditions. Overproduction and/or insufficient removal of ROS result in significant damage to cell structure and functions. In vitro studies showed that antioxidants, when applied directly and at relatively high concentrations to cellular systems, are effective in conferring protection against the damaging actions of ROS, but results from animal and human studies showed that several antioxidants provide only modest benefit and even possible harm. Antioxidants have yet to be rendered into reliable and safe therapies because of their poor solubility, inability to cross membrane barriers, extensive first-pass metabolism, and rapid clearance from cells. There is considerable interest towards the development of drug-delivery systems that would result in the selective delivery of antioxidants to tissues in sufficient concentrations to ameliorate oxidant-induced tissue injuries. Liposomes are biocompatible, biodegradable, and nontoxic artificial phospholipid vesicles that offer the possibility of carrying hydrophilic, hydrophobic, and amphiphilic molecules. This paper focus on the use of liposomes for the delivery of antioxidants in the prevention or treatment of pathological conditions related to oxidative stress. PMID:21876690

  10. Contribution of Oxidative Damage to Antimicrobial Lethality▿

    PubMed Central

    Wang, Xiuhong; Zhao, Xilin

    2009-01-01

    A potential pathway linking hydroxyl radicals to antimicrobial lethality was examined by using mutational and chemical perturbations of Escherichia coli. Deficiencies of sodA or sodB had no effect on norfloxacin lethality; however, the absence of both genes together reduced lethal activity, consistent with rapid conversion of excessive superoxide to hydrogen peroxide contributing to quinolone lethality. Norfloxacin was more lethal with a mutant deficient in katG than with its isogenic parent, suggesting that detoxification of peroxide to water normally reduces quinolone lethality. An iron chelator (bipyridyl) and a hydroxyl radical scavenger (thiourea) reduced the lethal activity of norfloxacin, indicating that norfloxacin-stimulated accumulation of peroxide affects lethal activity via hydroxyl radicals generated through the Fenton reaction. Ampicillin and kanamycin, antibacterials unrelated to fluoroquinolones, displayed behavior similar to that of norfloxacin except that these two agents showed hyperlethality with an ahpC (alkyl hydroperoxide reductase) mutant rather than with a katG mutant. Collectively, these data are consistent with antimicrobial stress increasing the production of superoxide, which then undergoes dismutation to peroxide, from which a highly toxic hydroxyl radical is generated. Hydroxyl radicals then enhance antimicrobial lethality, as suggested by earlier work. Such findings indicate that oxidative stress networks may provide targets for antimicrobial potentiation. PMID:19223646

  11. Involvement of oxidatively damaged DNA and repair in cancer development and aging

    PubMed Central

    Tudek, Barbara; Winczura, Alicja; Janik, Justyna; Siomek, Agnieszka; Foksinski, Marek; Oliński, Ryszard

    2010-01-01

    DNA damage and DNA repair may mediate several cellular processes, like replication and transcription, mutagenesis and apoptosis and thus may be important factors in the development and pathology of an organism, including cancer. DNA is constantly damaged by reactive oxygen species (ROS) and reactive nitrogen species (RNS) directly and also by products of lipid peroxidation (LPO), which form exocyclic adducts to DNA bases. A wide variety of oxidatively-generated DNA lesions are present in living cells. 8-oxoguanine (8-oxoGua) is one of the best known DNA lesions due to its mutagenic properties. Among LPO-derived DNA base modifications the most intensively studied are ethenoadenine and ethenocytosine, highly miscoding DNA lesions considered as markers of oxidative stress and promutagenic DNA damage. Although at present it is impossible to directly answer the question concerning involvement of oxidatively damaged DNA in cancer etiology, it is likely that oxidatively modified DNA bases may serve as a source of mutations that initiate carcinogenesis and are involved in aging (i.e. they may be causal factors responsible for these processes). To counteract the deleterious effect of oxidatively damaged DNA, all organisms have developed several DNA repair mechanisms. The efficiency of oxidatively damaged DNA repair was frequently found to be decreased in cancer patients. The present work reviews the basis for the biological significance of DNA damage, particularly effects of 8-oxoGua and ethenoadduct occurrence in DNA in the aspect of cancer development, drawing attention to the multiplicity of proteins with repair activities. PMID:20589166

  12. Repair of Oxidative DNA Damage in Saccharomyces cerevisiae.

    PubMed

    Chalissery, Jisha; Jalal, Deena; Al-Natour, Zeina; Hassan, Ahmed H

    2017-03-01

    Malfunction of enzymes that detoxify reactive oxygen species leads to oxidative attack on biomolecules including DNA and consequently activates various DNA repair pathways. The nature of DNA damage and the cell cycle stage at which DNA damage occurs determine the appropriate repair pathway to rectify the damage. Oxidized DNA bases are primarily repaired by base excision repair and nucleotide incision repair. Nucleotide excision repair acts on lesions that distort DNA helix, mismatch repair on mispaired bases, and homologous recombination and non-homologous end joining on double stranded breaks. Post-replication repair that overcomes replication blocks caused by DNA damage also plays a crucial role in protecting the cell from the deleterious effects of oxidative DNA damage. Mitochondrial DNA is also prone to oxidative damage and is efficiently repaired by the cellular DNA repair machinery. In this review, we discuss the DNA repair pathways in relation to the nature of oxidative DNA damage in Saccharomyces cerevisiae. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Oxidative damage in multiple sclerosis lesions.

    PubMed

    Haider, Lukas; Fischer, Marie T; Frischer, Josa M; Bauer, Jan; Höftberger, Romana; Botond, Gergö; Esterbauer, Harald; Binder, Christoph J; Witztum, Joseph L; Lassmann, Hans

    2011-07-01

    Multiple sclerosis is a chronic inflammatory disease of the central nervous system, associated with demyelination and neurodegeneration. The mechanisms of tissue injury are currently poorly understood, but recent data suggest that mitochondrial injury may play an important role in this process. Since mitochondrial injury can be triggered by reactive oxygen and nitric oxide species, we analysed by immunocytochemistry the presence and cellular location of oxidized lipids and oxidized DNA in lesions and in normal-appearing white matter of 30 patients with multiple sclerosis and 24 control patients without neurological disease or brain lesions. As reported before in biochemical studies, oxidized lipids and DNA were highly enriched in active multiple sclerosis plaques, predominantly in areas that are defined as initial or 'prephagocytic' lesions. Oxidized DNA was mainly seen in oligodendrocyte nuclei, which in part showed signs of apoptosis. In addition, a small number of reactive astrocytes revealed nuclear expression of 8-hydroxy-d-guanosine. Similarly, lipid peroxidation-derived structures (malondialdehyde and oxidized phospholipid epitopes) were seen in the cytoplasm of oligodendrocytes and some astrocytes. In addition, oxidized phospholipids were massively accumulated in a fraction of axonal spheroids with disturbed fast axonal transport as well as in neurons within grey matter lesions. Neurons stained for oxidized phospholipids frequently revealed signs of degeneration with fragmentation of their dendritic processes. The extent of lipid and DNA oxidation correlated significantly with inflammation, determined by the number of CD3 positive T cells and human leucocyte antigen-D expressing macrophages and microglia in the lesions. Our data suggest profound oxidative injury of oligodendrocytes and neurons to be associated with active demyelination and axonal or neuronal injury in multiple sclerosis.

  14. LOX-1, oxidant stress, mtDNA damage, autophagy, and immune response in atherosclerosis.

    PubMed

    Ding, Zufeng; Liu, Shijie; Wang, Xianwei; Dai, Yao; Khaidakov, Magomed; Romeo, Francesco; Mehta, Jawahar L

    2014-07-01

    As a major receptor for oxidized low density lipoprotein (ox-LDL), lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is upregulated in many pathophysiological events, including endothelial cell dysfunction and smooth muscle cell growth, as well as monocyte migration and transformation into foam cells, which are present in atherosclerosis and myocardial ischemia. Excessive production of reactive oxygen species (ROS) increases LOX-1 expression, induces mitochondrial DNA damage, and activates autophagy. Damaged mitochondrial DNA that escapes from autophagy induces an inflammatory response. This paper reviews the potential link between LOX-1, mitochondrial DNA damage, autophagy, and immune response in atherosclerosis.

  15. Pathophysiology of Bronchoconstriction: Role of Oxidatively Damaged DNA Repair

    PubMed Central

    Bacsi, Attila; Pan, Lang; Ba, Xueqing; Boldogh, Istvan

    2016-01-01

    Purpose of review To provide an overview on the present understanding of roles of oxidative DNA damage repair in cell signaling underlying bronchoconstriction common to, but not restricted to various forms of asthma and chronic obstructive pulmonary disease Recent findings Bronchoconstriction is a tightening of smooth muscle surrounding the bronchi and bronchioles with consequent wheezing and shortness of breath. Key stimuli include air pollutants, viral infections, allergens, thermal and osmotic changes, and shear stress of mucosal epithelium, triggering a wide range of cellular, vascular and neural events. Although activation of nerve fibers, the role of G-proteins, protein kinases and Ca++, and molecular interaction within contracting filaments of muscle are well defined, the overarching mechanisms by which a wide range of stimuli initiate these events are not fully understood. Many, if not all, stimuli increase levels of reactive oxygen species (ROS), which are signaling and oxidatively modifying macromolecules, including DNA. The primary ROS target in DNA is guanine, and 8-oxoguanine is one of the most abundant base lesions. It is repaired by 8-oxoguanine DNA glycosylase1 (OGG1) during base excision repair processes. The product, free 8-oxoG base, is bound by OGG1 with high affinity, and the complex then functions as an activator of small GTPases, triggering pathways for inducing gene expression and contraction of intracellular filaments in mast and smooth muscle cells. Summary Oxidative DNA damage repair-mediated cell activation signaling result in gene expression that “primes” the mucosal epithelium and submucosal tissues to generate mediators of airway smooth muscle contractions. PMID:26694039

  16. Pathology of perinatal brain damage: background and oxidative stress markers.

    PubMed

    Tonni, Gabriele; Leoncini, Silvia; Signorini, Cinzia; Ciccoli, Lucia; De Felice, Claudio

    2014-07-01

    To review historical scientific background and new perspective on the pathology of perinatal brain damage. The relationship between birth asphyxia and subsequent cerebral palsy has been extensively investigated. The role of new and promising clinical markers of oxidative stress (OS) is presented. Electronic search of PubMed-Medline/EMBASE database has been performed. Laboratory and clinical data involving case series from the research group are reported. The neuropathology of birth asphyxia and subsequent perinatal brain damage as well as the role of electronic fetal monitoring are reported following a review of the medical literature. This review focuses on OS mechanisms underlying the neonatal brain damage and provides different perspective on the most reliable OS markers during the perinatal period. In particular, prior research work on neurodevelopmental diseases, such as Rett syndrome, suggests the measurement of oxidized fatty acid molecules (i.e., F4-Neuroprostanes and F2-Dihomo-Isoprostanes) closely related to brain white and gray matter oxidative damage.

  17. OXIDATIVE DNA DAMAGE IN DIESEL BUS MECHANICS

    EPA Science Inventory

    Rationale:

    Diesel exposure has been associated with adverse health effects, including susceptibility to asthma, allergy and cancer. Previous epidemiological studies demonstrated increased cancer incidence among workers exposed to diesel. This is likely due to oxid...

  18. OXIDATIVE DNA DAMAGE IN DIESEL BUS MECHANICS

    EPA Science Inventory

    Rationale:

    Diesel exposure has been associated with adverse health effects, including susceptibility to asthma, allergy and cancer. Previous epidemiological studies demonstrated increased cancer incidence among workers exposed to diesel. This is likely due to oxid...

  19. Strong, damage tolerant oxide-fiber/oxide matrix composites

    NASA Astrophysics Data System (ADS)

    Bao, Yahua

    cationic polyelectrolytes to have a positive surface charge and then dipped into diluted, negatively-charged AlPO4 colloidal suspension (0.05M) at pH 7.5. Amorphous AlPO4 (crystallizes to tridymite- and cristobalite-forms at 1080°C) nano particles were coated on fibers layer-by-layer using an electrostatic attraction protocol. A uniform and smooth coating was formed which allowed fiber pullout from the matrix of a Nextel 720/alumina mini-composite hot-pressed at 1250°C/20MPa. Reaction-bonded mullite (RBM), with low formation temperature and sintering shrinkage was synthesized by incorporation of mixed-rare-earth-oxide (MREO) and mullite seeds. Pure mullite formed with 7.5wt% MREO at 1300°C. Introduction of 5wt% mullite seeds gave RBM with less than 3% shrinkage and 20% porosity. AlPO4-coated Nextel 720/RBM composites were successful fabricated by EPID and pressureless sintering at 1300°C. Significant fiber pullout occurred and the 4-point bend strength was around 170MPa (with 25-30vol% fibers) at room temperature and 1100°C and a Work-of-Fracture 7KJ/m2. At 1200°C, the composite failed in shear due to the MREO-based glassy phase in the matrix. AlPO4-coated Nextel 720 fiber/aluminosilicate (no MREO) showed damage tolerance at 1200°C with a bend strength 170MPa.

  20. Oxidative Damage in the Guinea Pig Hippocampal Slice

    DTIC Science & Technology

    1989-01-01

    oxidation to the observed damage. the actions of the oxidants, chloramine -T and N-chlorosuccinimide (NCS). were studied on electrophysiological...hippocampus evoked a population postsynaptic potential (population PSP) in the dendritic layer and a population spike in the cell body layer. Chloramine -T (25...produced by free radicals but can rot account for the postsynaptic effects. Keywords- Chloramine -T. N-chlorosuccinimide. Oxidation. Free radical

  1. Photoexcited riboflavin induces oxidative damage to human serum albumin

    NASA Astrophysics Data System (ADS)

    Hirakawa, Kazutaka; Yoshioka, Takuto

    2015-08-01

    Photoexcited riboflavin induced damage of human serum albumin (HSA), a water soluble protein, resulting in the diminishment of fluorescence from the tryptophan residue. Because riboflavin hardly photosensitized singlet oxygen generation and sodium azide, a singlet oxygen quencher, did not inhibit protein damage, electron transfer-mediated oxidation of HSA was speculated. Fluorescence lifetime of riboflavin was not affected by HSA, suggesting that the excited triplet state of riboflavin is responsible for protein damage through electron transfer. In addition, the preventive effect of xanthone derivatives, triplet quenchers, on photosensitized protein damage could be evaluated using this photosensitized reaction system of riboflavin and HSA.

  2. Oxidative DNA Damage in Blood of CVD Patients Taking Detralex

    PubMed Central

    Krzyściak, Wirginia; Cierniak, Agnieszka; Kózka, Mariusz; Kozieł, Joanna

    2011-01-01

    The main goal of the work reported here was to determine the degree of oxidative/alkali-labile DNA damages in peripheral blood as well as in the blood stasis from varicose vein of (chronic venous disorder) CVD patients. Moreover, determination of the impact of Detralex usage on the level of (oxidative) DNA damages in CVD patients was evaluated as well. The degree of oxidative DNA damages was studied in a group consisted of thirty patients with diagnosed chronic venous insufficiency (CVI) in the 2nd and 3rd degree, according to clinical state, etiology, anatomy and pathophysiology (CEAP), and qualified to surgical procedure. The control group consisted of normal volunteers (blood donors) qualified during standard examinations at Regional Centers of Blood Donation and Blood Therapy. The comet assay was used for determination of DNA damages. Analyses of the obtained results showed increase in the level of oxidative/alkali-labile DNA damages in lymphocytes originating from antebrachial blood of CVD patients as compared to the control group (Control) (p < 0.002; ANOVA). In addition, it was demonstrated that the usage of Detralex® resulted in decrease of the level of oxidative/alkali-labile DNA damages in CVD patients as compared to patients without Detralex® treatment (p < 0.001; ANOVA). Based on findings from the study, it may be hypothesized about occurrence of significant oxidative DNA damages as the consequence of strong oxidative stress in CVD. In addition, antioxidative effectiveness of Detralexu® was observed at the recommended dose, one tablet twice daily. PMID:21912579

  3. Oxidative DNA damage in osteoarthritic porcine articular cartilage

    PubMed Central

    Chen, Antonia F.; Davies, Catrin M.; De Lin, Ming; Fermor, Beverley

    2008-01-01

    Purpose Osteoarthritis (OA) is associated with increased levels of reactive oxygen species. This study investigated if increased oxidative DNA damage accumulates in OA articular cartilage compared with non-OA articular cartilage from pigs with spontaneous OA. Additionally, the ability of nitric oxide (NO) or peroxynitrite (ONOO-) induced DNA damage in non-OA chondrocytes to undergo endogenous repair was investigated. Methods Porcine femoral condyles were graded for the stage of OA, macroscopically by the Collins Scale, and histologically by the modified Mankin Grade. Levels of DNA damage were determined in non-OA and OA cartilage, using the comet assay. For calibration, DNA damage was measured by exposing non-OA chondrocytes to 0-12 Gray of x-ray irradiation. Non-OA articular chondrocytes were treated with 0-500 μM of NO donors (NOC-18 or SIN-1), and DNA damage assessed after treatment and 5 days recovery. Results A significant increase (p<0.01) in oxidative DNA damage occurred in OA chondrocytes in joints with Mankin Grades 3 or greater, compared to non-OA chondrocytes. The percentage of nuclei containing DNA damage increased significantly (p<0.001) from early to late grades of OA. An increase of approximately 0.65-1.7 breaks/1000kB of DNA occurred in OA, compared to non-OA nuclei. NOC-18 or SIN-1 caused significant DNA damage (p<0.001) in non-OA chondrocytes that did not undergo full endogenous repair after 5 days (p<0.05). Conclusion Our data suggest significant levels of oxidative DNA damage occur in OA chondrocytes that accumulates with OA progression. Additionally, DNA damage induced by NO and ONOO- in non-OA chondrocytes does not undergo full endogenous repair. PMID:18720406

  4. Hydrogen sulfide induces oxidative damage to RNA and DNA in a sulfide-tolerant marine invertebrate.

    PubMed

    Joyner-Matos, Joanna; Predmore, Benjamin L; Stein, Jenny R; Leeuwenburgh, Christiaan; Julian, David

    2010-01-01

    Hydrogen sulfide acts as an environmental toxin across a range of concentrations and as a cellular signaling molecule at very low concentrations. Despite its toxicity, many animals, including the mudflat polychaete Glycera dibranchiata, are periodically or continuously exposed to sulfide in their environment. We tested the hypothesis that a broad range of ecologically relevant sulfide concentrations induces oxidative stress and oxidative damage to RNA and DNA in G. dibranchiata. Coelomocytes exposed in vitro to sulfide (0-3 mmol L(-1) for 1 h) showed dose-dependent increases in oxidative stress (as 2',7'-dichlorofluorescein fluorescence) and superoxide production (as dihydroethidine fluorescence). Coelomocytes exposed in vitro to sulfide (up to 0.73 mmol L(-1) for 2 h) also acquired increased oxidative damage to RNA (detected as 8-oxo-7,8-dihydroguanosine) and DNA (detected as 8-oxo-7,8-dihydro-2'-deoxyguanosine). Worms exposed in vivo to sulfide (0-10 mmol L(-1) for 24 h) acquired elevated oxidative damage to RNA and DNA in both coelomocytes and body wall tissue. While the consequences of RNA and DNA oxidative damage are poorly understood, oxidatively damaged deoxyguanosine bases preferentially bind thymine, causing G-T transversions and potentially causing heritable point mutations. This suggests that sulfide can be an environmental mutagen in sulfide-tolerant invertebrates.

  5. Oxidatively generated base damage to cellular DNA by hydroxyl radical and one-electron oxidants: similarities and differences.

    PubMed

    Cadet, Jean; Wagner, J Richard

    2014-09-01

    Hydroxyl radical (OH) and one-electron oxidants that may be endogenously formed through oxidative metabolism, phagocytosis, inflammation and pathological conditions constitute the main sources of oxidatively generated damage to cellular DNA. It is worth mentioning that exposure of cells to exogenous physical agents (UV light, high intensity UV laser, ionizing radiation) and chemicals may also induce oxidatively generated damage to DNA. Emphasis is placed in this short review article on the mechanistic aspects of OH and one-electron oxidant-mediated formation of single and more complex damage (tandem lesions, intra- and interstrand cross-links, DNA-protein cross-links) in cellular DNA arising from one radical hit. This concerns DNA modifications that have been accurately measured using suitable analytical methods such as high performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry. Evidence is provided that OH and one-electron oxidants after generating neutral radicals and base radical cations respectively may partly induce common degradation pathways. In addition, selective oxidative reactions giving rise to specific degradation products of OH and one-electron oxidation reactions that can be used as representative biomarkers of these oxidants have been identified.

  6. Viewing oxidative stress through the lens of oxidative signalling rather than damage.

    PubMed

    Foyer, Christine H; Ruban, Alexander V; Noctor, Graham

    2017-03-07

    Concepts of the roles of reactive oxygen species (ROS) in plants and animals have shifted in recent years from focusing on oxidative damage effects to the current view of ROS as universal signalling metabolites. Rather than having two opposing activities, i.e. damage and signalling, the emerging concept is that all types of oxidative modification/damage are involved in signalling, not least in the induction of repair processes. Examining the multifaceted roles of ROS as crucial cellular signals, we highlight as an example the loss of photosystem II function called photoinhibition, where photoprotection has classically been conflated with oxidative damage.

  7. Oxidative DNA damage and repair in teratogenesis and neurodevelopmental deficits.

    PubMed

    Wells, Peter G; McCallum, Gordon P; Lam, Kyla C H; Henderson, Jeffrey T; Ondovcik, Stephanie L

    2010-06-01

    Several teratogenic agents, including ionizing radiation and xenobiotics such as phenytoin, benzo[a]pyrene, thalidomide, and methamphetamine, can initiate the formation of reactive oxygen species (ROS) that oxidatively damage cellular macromolecules including DNA. Oxidative DNA damage, and particularly the most prevalent 8-oxoguanine lesion, may adversely affect development, likely via alterations in gene transcription rather than via a mutational mechanism. Contributions from oxidative DNA damage do not exclude roles for alternative mechanisms of initiation like receptor-mediated processes or the formation of covalent xenobiotic-macromolecular adducts, damage to other macromolecular targets like proteins and lipids, and other effects of ROS like altered signal transduction. Even in the absence of teratogen exposure, endogenous developmental oxidative stress can have embryopathic consequences in the absence of key pathways for detoxifying ROS or repairing DNA damage. Critical proteins in pathways for DNA damage detection/repair signaling, like p53 and ataxia telangiectasia mutated, and DNA repair itself, like oxoguanine glycosylase 1 and Cockayne syndrome B, can often, but not always, protect the embryo from ROS-initiating teratogens. Protection may be variably dependent upon such factors as the nature of the teratogen and its concentration within the embryo, the stage of development, the species, strain, gender, target tissue and cell type, among other factors.

  8. Acrylonitrile-Induced Oxidative Stress and Oxidative DNA Damage in Male Sprague-Dawley Rats

    PubMed Central

    Kamendulis, Lisa M.; Klaunig, James E.

    2009-01-01

    Studies have demonstrated that the induction of oxidative stress may be involved in brain tumor induction in rats by acrylonitrile. The present study examined whether acrylonitrile induces oxidative stress and DNA damage in rats and whether blood can serve as a valid surrogate for the biomonitoring of oxidative stress induced by acrylonitrile in the exposed population. Male Sprague-Dawley rats were treated with 0, 3, 30, 100, and 200 ppm acrylonitrile in drinking water for 28 days. One group of rats were also coadministered N-acetyl cysteine (NAC) (0.3% in diet) with acrylonitrile (200 ppm in drinking water) to examine whether antioxidant supplementation was protective against acrylonitrile-induced oxidative stress. Direct DNA strand breakage in white blood cells (WBC) and brain was measured using the alkaline comet assay. Oxidative DNA damage in WBC and brain was evaluated using formamidopyrimidine DNA glycosylase (fpg)-modified comet assay and with high-performance liquid chromatography-electrochemical detection. No significant increase in direct DNA strand breaks was observed in brain and WBC from acrylonitrile-treated rats. However, oxidative DNA damage (fpg comet and 8′hydroxyl-2-deoxyguanosine) in brain and WBC was increased in a dose-dependent manner. In addition, plasma levels of reactive oxygen species (ROS) increased in rats administered acrylonitrile. Dietary supplementation with NAC prevented acrylonitrile-induced oxidative DNA damage in brain and WBC. A slight, but significant, decrease in the GSH:GSSG ratio was seen in brain at acrylonitrile doses > 30 ppm. These results provide additional support that the mode of action for acrylonitrile-induced astrocytomas involves the induction of oxidative stress and damage. Significant associations were seen between oxidative DNA damage in WBC and brain, ROS formation in plasma, and the reported tumor incidences. Since oxidative DNA damage in brain correlated with oxidative damage in WBC, these results suggest

  9. Tempol protects blood proteins and lipids against peroxynitrite-mediated oxidative damage

    PubMed Central

    Mustafa, Ayman G; Bani-Ahmad, Mohammad A; Jaradat, Ahmad Q

    2015-01-01

    Oxidative stress is characterized by excessive production of various free radicals and reactive species among which, peroxynitrite is most frequently produced in several pathological conditions. Peroxynitrite is the product of the superoxide anion reaction with nitric oxide, which is reported to take place in the intravascular compartment. Several studies have reported that peroxynitrite targets red blood cells, platelets and plasma proteins, and induces various forms of oxidative damage. This in vitro study was designed to further characterize the types of oxidative damage induced in platelets and plasma proteins by peroxynitrite. This study also determined the ability of tempol to protect blood plasma and platelets against peroxynitrite-induced oxidative damage. The ability of various concentrations of tempol (25, 50, 75, and 100 µM) to antagonize peroxynitrite-induced oxidation was evaluated by measuring the levels of protein carbonyl groups and thiobarbituric-acid-reactive substances in experimental groups. Exposure of platelets and plasma to 100 µM peroxynitrite resulted in an increased levels of carbonyl groups and lipid peroxidation (P < 0.05). Tempol significantly inhibited carbonyl group formation in plasma and platelet proteins (P < 0.05). In addition, tempol significantly reduced the levels of lipid peroxidation in both plasma and platelet samples (P < 0.05). Thus, tempol has antioxidative properties against peroxynitrite-induced oxidative damage in blood plasma and platelets. PMID:25107897

  10. Oxidative Damage in Parkinson’s Disease

    DTIC Science & Technology

    2003-01-01

    supranuclear palsy brains. There were no significant alterations in 8-hydroxy-2- deoxyguanosine in the plasma of PD patients. We found that...patients and a number of specific genes linked to oxidative stress were reduced in expression. There was increased lipid peroxidation in progressive

  11. Protective effect of Pterostilbene against free radical mediated oxidative damage

    PubMed Central

    2013-01-01

    Background Pterostilbene, a methoxylated analog of Resveratrol, is gradually gaining more importance as a therapeutic drug owing to its higher lipophilicity, bioavailability and biological activity than Resveratrol. This study was undertaken to characterize its ability to scavenge free radicals such as superoxide, hydroxyl and hydrogen peroxide and to protect bio-molecules within a cell against oxidative insult. Methods Anti-oxidant activity of Pterostilbene was evaluated extensively by employing several in vitro radical scavenging/inhibiting assays and pulse radiolysis study. In addition, its ability to protect rat liver mitochondria against tertiary-butyl hydroperoxide (TBHP) and hydroxyl radical generated oxidative damage was determined by measuring the damage markers such as protein carbonyls, protein sulphydryls, lipid hydroperoxides, lipid peroxides and 8-hydroxy-2'-deoxyguanosine. Pterostilbene was also evaluated for its ability to inhibit •OH radical induced single strand breaks in pBR322 DNA. Result Pterostilbene exhibited strong anti-oxidant activity against various free radicals such as DPPH, ABTS, hydroxyl, superoxide and hydrogen peroxide in a concentration dependent manner. Pterostilbene conferred protection to proteins, lipids and DNA in isolated mitochondrial fractions against TBHP and hydroxyl radical induced oxidative damage. It also protected pBR322 DNA against oxidative assault. Conclusions Thus, present study provides an evidence for the strong anti-oxidant property of Pterostilbene, methoxylated analog of Resveratrol, thereby potentiating its role as an anti-oxidant. PMID:24070177

  12. DNA damage and oxidative status in PFAPA syndrome.

    PubMed

    Tuğrul, Selahattin; Doğan, Remzi; Kocyigit, Abdurrahim; Torun, Emel; Senturk, Erol; Ozturan, Orhan

    2015-10-01

    PFAPA syndrome is a clinical entity of unknown etiology which presents with periodic episodes of fever, aphthous stomatitis, tonsillitis or pharyngitis, and cervical adenitis. In this study we investigated DNA damage and the oxidative stress parameters in patients diagnosed with PFAPA, to elucidate the underlying pathophysiological mechanism of this syndrome. Thirty-one patients diagnosed with PFAPA (Group 1), 22 patients diagnosed with normal tonsillitis or pharyngitis (Group 2), and 20 healthy volunteers (Group 3) were included in our study. Heparinized peripheral blood samples were drawn from all patients and volunteers. DNA damage was assessed by single cell alkaline electrophoresis assay in peripheral mononuclear leukocytes. Plasma levels of total antioxidant status (TAS) and total oxidative status (TOS) were determined by using a novel automated measurement method, and oxidative stress index (OSI) was calculated. DNA damage in the mononuclear leukocytes of Group 1 was significantly higher than that of Group 2 and Group 3. The oxidative stress parameters revealed that the TOS and OSI values of Group 1 were significantly higher than those of Group 2 and Group 3. TAS values of Group 1 were significantly lower than those of Group 2 and Group 3. Correlation analysis of Group 1 demonstrated a significant correlation between TOS, one of the oxidative stress parameters, and DNA damage. Correlations between DNA damage and C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) values were also significant. Our study indicated that both the inflammatory and the oxidative stress parameters were significantly increased in patients with PFAPA syndrome, accompanied by a significant positive correlation between DNA damage and oxidative stress. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  13. Prevention of mitochondrial oxidative damage as a therapeutic strategy in diabetes.

    PubMed

    Green, Katherine; Brand, Martin D; Murphy, Michael P

    2004-02-01

    Hyperglycemia causes many of the pathological consequences of both type 1 and type 2 diabetes. Much of this damage is suggested to be a consequence of elevated production of reactive oxygen species by the mitochondrial respiratory chain during hyperglycemia. Mitochondrial radical production associated with hyperglycemia will also disrupt glucose-stimulated insulin secretion by pancreatic beta-cells, because pancreatic beta-cells are particularly susceptible to oxidative damage. Therefore, mitochondrial radical production in response to hyperglycemia contributes to both the progression and pathological complications of diabetes. Consequently, strategies to decrease mitochondrial radical production and oxidative damage may have therapeutic potential. This could be achieved by the use of antioxidants or by decreasing the mitochondrial membrane potential. Here, we outline the background to these strategies and discuss how antioxidants targeted to mitochondria, or selective mitochondrial uncoupling, may be potential therapies for diabetes.

  14. Lipids and Oxidative Stress Associated with Ethanol-Induced Neurological Damage.

    PubMed

    Hernández, José A; López-Sánchez, Rosa C; Rendón-Ramírez, Adela

    2016-01-01

    The excessive intake of alcohol is a serious public health problem, especially given the severe damage provoked by chronic or prenatal exposure to alcohol that affects many physiological processes, such as memory, motor function, and cognitive abilities. This damage is related to the ethanol oxidation in the brain. The metabolism of ethanol to acetaldehyde and then to acetate is associated with the production of reactive oxygen species that accentuate the oxidative state of cells. This metabolism of ethanol can induce the oxidation of the fatty acids in phospholipids, and the bioactive aldehydes produced are known to be associated with neurotoxicity and neurodegeneration. As such, here we will review the role of lipids in the neuronal damage induced by ethanol-related oxidative stress and the role that lipids play in the related compensatory or defense mechanisms.

  15. Lipids and Oxidative Stress Associated with Ethanol-Induced Neurological Damage

    PubMed Central

    2016-01-01

    The excessive intake of alcohol is a serious public health problem, especially given the severe damage provoked by chronic or prenatal exposure to alcohol that affects many physiological processes, such as memory, motor function, and cognitive abilities. This damage is related to the ethanol oxidation in the brain. The metabolism of ethanol to acetaldehyde and then to acetate is associated with the production of reactive oxygen species that accentuate the oxidative state of cells. This metabolism of ethanol can induce the oxidation of the fatty acids in phospholipids, and the bioactive aldehydes produced are known to be associated with neurotoxicity and neurodegeneration. As such, here we will review the role of lipids in the neuronal damage induced by ethanol-related oxidative stress and the role that lipids play in the related compensatory or defense mechanisms. PMID:26949445

  16. OXIDATIVE DNA DAMAGE FROM POTASSIUM BROMATE EXPOSURE IN LONG-EVANS RATS IS NOT ENHANCED BY A MIXTURE OF DRINKING WATER DISINFECTION BY-PRODUCTS

    EPA Science Inventory

    Public drinking water treated with chemical disinfectants contains a complex mixture of disinfection by-products (DBPs) for which the relative toxicity of the mixtures needs to be characterized to accurately assess risk. Potassium bromate (KBrO3) is a by-product from ozonation of...

  17. OXIDATIVE DNA DAMAGE FROM POTASSIUM BROMATE EXPOSURE IN LONG-EVANS RATS IS NOT ENHANCED BY A MIXTURE OF DRINKING WATER DISINFECTION BY-PRODUCTS

    EPA Science Inventory

    Public drinking water treated with chemical disinfectants contains a complex mixture of disinfection by-products (DBPs) for which the relative toxicity of the mixtures needs to be characterized to accurately assess risk. Potassium bromate (KBrO3) is a by-product from ozonation of...

  18. Gentamicin induced nitric oxide-related oxidative damages on vestibular afferents in the guinea pig.

    PubMed

    Hong, Sung Hwa; Park, Sook Kyung; Cho, Yang-Sun; Lee, Hyun-Seok; Kim, Ki Ryung; Kim, Myung Gu; Chung, Won-Ho

    2006-01-01

    Gentamicin is a well-known ototoxic aminoglycoside. However, the mechanism underlying this ototoxicity remains unclear. One of the mechanisms which may be responsible for this ototoxicity is excitotoxic damage to hair cells. The overstimulation of the N-methyl-d-aspartate (NMDA) receptors increases the production of nitric oxide (NO), which induces oxidative stress on hair cells. In order to determine the mechanism underlying this excitotoxicity, we treated guinea pigs with gentamicin by placing gentamicin (0.5 mg) pellets into a round window niche. After the sacrifice of the animals, which occurred at 3, 7 and 14 days after the treatment, the numbers of hair cells in the animals were counted with a scanning electron microscope. We then performed immunostaining using neuronal nitric oxide synthase (nNOS), inducible NOS (iNOS) and nitrotyrosine antibodies. The number of hair cells in the animals was found to decrease significantly after 7 days. nNOS and iNOS expression levels were observed to have increased 3 days after treatment. Nitrotyrosine was expressed primarily at the calyceal afferents of the type I hair cells 3 days after treatment. Terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) staining revealed positive hair cells 3 days after treatment. Our results suggest that inner ear treatment with gentamicin may upregulate nNOS and iNOS to induce oxidative stress in the calyceal afferents of type I hair cells, via nitric oxide overproduction.

  19. Induction of oxidative stress and oxidative damage in rat glial cells by acrylonitrile.

    PubMed

    Kamendulis, L M; Jiang, J; Xu, Y; Klaunig, J E

    1999-08-01

    Chronic treatment of rats with acrylonitrile (ACN) resulted in a dose-related increase in glial cell tumors (astrocytomas). While the exact mechanism(s) for ACN-induced carcinogenicity remains unresolved, non-genotoxic and possibly tumor promotion modes of action appear to be involved in the induction of glial tumors. Recent studies have shown that ACN induced oxidative stress selectively in rat brain in a dose-responsive manner. The present study examined the ability of ACN to induce oxidative stress in a rat glial cell line, a target tissue, and in cultured rat hepatocytes, a non-target tissue of ACN carcinogenicity. Glial cells and hepatocytes were treated for 1, 4 and 24 h with sublethal concentrations of ACN. ACN induced an increase in oxidative DNA damage, as evidenced by increased production of 8-hydroxy-2'-deoxyguanosine (8-OH-dG) in glial cells but not in rat hepatocytes. Hydroxyl radical formation following ACN treatment was also selectively increased in glial cells. Following 1 and 4 h of ACN exposure, the levels of the non-enzymatic antioxidant glutathione, as well as the activities of the enzymatic antioxidants catalase and superoxide dismutase were significantly decreased in the rat glial cells. Lipid peroxidation and the activity of glutathione peroxidase were not affected by ACN treatment in rat glial cells. No changes in any of these biomarkers of oxidative stress were observed in hepatocytes treated with ACN. These data indicate that ACN selectively induced oxidative stress in rat glial cells.

  20. Maternal diabetes triggers DNA damage and DNA damage response in neurulation stage embryos through oxidative stress

    PubMed Central

    Dong, Daoyin; Yu, Jingwen; Wu, Yanqing; Fu, Noah; Villela, Natalia Arias; Yang, Peixin

    2015-01-01

    DNA damage and DNA damage response (DDR) in neurulation stage embryos under maternal diabetes conditions are not well understood. The purpose of this study was to investigate whether maternal diabetes and high glucose in vitro induce DNA damage and DDR in the developing embryo through oxidative stress. In vivo experiments were conducted by mating superoxide dismutase 1 (SOD1) transgenic male mice with wild-type (WT) female mice with or without diabetes. Embryonic day 8.75 (E8.75) embryos were tested for the DNA damage markers, phosphorylated histone H2A.X (p-H2A.X) and DDR signaling intermediates, including phosphorylated checkpoint 1 (p-Chk1), phosphorylated checkpoint 2 (p-Chk2), and p53. Levels of the same DNA damage markers and DDR signaling intermediates were also determined in the mouse C17.2 neural stem cell line. Maternal diabetes and high glucose in vitro significantly increased the levels of p-H2A.X. Levels of p-Chk1, p-Chk2, and p53, were elevated under both maternal diabetic and high glucose conditions. SOD1 overexpression blocked maternal diabetes-induced DNA damage and DDR in vivo. Tempol, a SOD1 mimetic, diminished high glucose-induced DNA damage and DDR in vitro. In conclusion, maternal diabetes and high glucose in vitro induce DNA damage and activates DDR through oxidative stress, which may contribute to the pathogenesis of diabetes-associated embryopathy. PMID:26427872

  1. Characterization of Oxidative Guanine Damage and Repair in Mammalian Telomeres

    PubMed Central

    Wang, Zhilong; Rhee, David B.; Lu, Jian; Bohr, Christina T.; Zhou, Fang; Vallabhaneni, Haritha; de Souza-Pinto, Nadja C.; Liu, Yie

    2010-01-01

    8-oxo-7,8-dihydroguanine (8-oxoG) and 2,6-diamino-4-hydroxy-5-formamidopyrimidine (FapyG) are among the most common oxidative DNA lesions and are substrates for 8-oxoguanine DNA glycosylase (OGG1)–initiated DNA base excision repair (BER). Mammalian telomeres consist of triple guanine repeats and are subject to oxidative guanine damage. Here, we investigated the impact of oxidative guanine damage and its repair by OGG1 on telomere integrity in mice. The mouse cells were analyzed for telomere integrity by telomere quantitative fluorescence in situ hybridization (telomere–FISH), by chromosome orientation–FISH (CO–FISH), and by indirect immunofluorescence in combination with telomere–FISH and for oxidative base lesions by Fpg-incision/Southern blot assay. In comparison to the wild type, telomere lengthening was observed in Ogg1 null (Ogg1−/−) mouse tissues and primary embryonic fibroblasts (MEFs) cultivated in hypoxia condition (3% oxygen), whereas telomere shortening was detected in Ogg1−/− mouse hematopoietic cells and primary MEFs cultivated in normoxia condition (20% oxygen) or in the presence of an oxidant. In addition, telomere length abnormalities were accompanied by altered telomere sister chromatid exchanges, increased telomere single- and double-strand breaks, and preferential telomere lagging- or G-strand losses in Ogg1−/− mouse cells. Oxidative guanine lesions were increased in telomeres in Ogg1−/− mice with aging and primary MEFs cultivated in 20% oxygen. Furthermore, oxidative guanine lesions persisted at high level in Ogg1−/− MEFs after acute exposure to hydrogen peroxide, while they rapidly returned to basal level in wild-type MEFs. These findings indicate that oxidative guanine damage can arise in telomeres where it affects length homeostasis, recombination, DNA replication, and DNA breakage repair. Our studies demonstrate that BER pathway is required in repairing oxidative guanine damage in telomeres and maintaining

  2. CUPRAC colorimetric and electroanalytical methods determining antioxidant activity based on prevention of oxidative DNA damage.

    PubMed

    Uzunboy, Seda; Çekiç, Sema Demirci; Eksin, Ece; Erdem, Arzum; Apak, Reşat

    2017-02-01

    An unbalanced excess of oxygen/nitrogen species (ROS/RNS) can give oxidative hazard to DNA and other biomacromolecules under oxidative stress conditions. While the 'comet' assay for measuring DNA damage is neither specific nor practical, monitoring oxidative changes on individual DNA bases and other oxidation products needs highly specialized equipment and operators. Thus, we developed a modified CUPRAC (cupric ion reducing antioxidant capacity) colorimetric method to determine the average total damage on DNA produced by Fenton oxidation, taking advantage of the fact that the degradation products of DNA but not the original macromolecule is CUPRAC-responsive. The DNA-protective effects of water-soluble antioxidants were used to devise a novel antioxidant activity assay, considered to be physiologically more realistic than those using artificial probes. Our method, based on the measurement of DNA oxidative products with CUPRAC colorimetry proved to be 2 orders-of-magnitude more sensitive than the widely used TBARS (thiobarbituric acid-reactive substances) colorimetric assay used as reference. Additionally, the DNA damage was electrochemically investigated using pencil graphite electrodes (PGEs) as DNA sensor platform in combination with differential pulse voltammetry (DPV). The interaction of the radical species with DNA in the absence/presence of antioxidants was detected according to the changes in guanine oxidation signal.

  3. Elevated oxidative damage is correlated with reduced fitness in interpopulation hybrids of a marine copepod

    PubMed Central

    Barreto, Felipe S.; Burton, Ronald S.

    2013-01-01

    Aerobic energy production occurs via the oxidative phosphorylation pathway (OXPHOS), which is critically dependent on interactions between the 13 mitochondrial DNA (mtDNA)-encoded and approximately 70 nuclear-encoded protein subunits. Disruptive mutations in any component of OXPHOS can result in impaired ATP production and exacerbated oxidative stress; in mammalian systems, such mutations are associated with ageing as well as numerous diseases. Recent studies have suggested that oxidative stress plays a role in fitness trade-offs in life-history evolution and functional ecology. Here, we show that outcrossing between populations with divergent mtDNA can exacerbate cellular oxidative stress in hybrid offspring. In the copepod Tigriopus californicus, we found that hybrids that showed evidence of fitness breakdown (low fecundity) also exhibited elevated levels of oxidative damage to DNA, whereas those with no clear breakdown did not show significantly elevated damage. The extent of oxidative stress in hybrids appears to be dependent on the degree of genetic divergence between their respective parental populations, but this pattern requires further testing using multiple crosses at different levels of divergence. Given previous evidence in T. californicus that hybridization disrupts nuclear/mitochondrial interactions and reduces hybrid fitness, our results suggest that such negative intergenomic epistasis may also increase the production of damaging cellular oxidants; consequently, mtDNA evolution may play a significant role in generating postzygotic isolating barriers among diverging populations. PMID:23902912

  4. Elevated oxidative damage is correlated with reduced fitness in interpopulation hybrids of a marine copepod.

    PubMed

    Barreto, Felipe S; Burton, Ronald S

    2013-09-22

    Aerobic energy production occurs via the oxidative phosphorylation pathway (OXPHOS), which is critically dependent on interactions between the 13 mitochondrial DNA (mtDNA)-encoded and approximately 70 nuclear-encoded protein subunits. Disruptive mutations in any component of OXPHOS can result in impaired ATP production and exacerbated oxidative stress; in mammalian systems, such mutations are associated with ageing as well as numerous diseases. Recent studies have suggested that oxidative stress plays a role in fitness trade-offs in life-history evolution and functional ecology. Here, we show that outcrossing between populations with divergent mtDNA can exacerbate cellular oxidative stress in hybrid offspring. In the copepod Tigriopus californicus, we found that hybrids that showed evidence of fitness breakdown (low fecundity) also exhibited elevated levels of oxidative damage to DNA, whereas those with no clear breakdown did not show significantly elevated damage. The extent of oxidative stress in hybrids appears to be dependent on the degree of genetic divergence between their respective parental populations, but this pattern requires further testing using multiple crosses at different levels of divergence. Given previous evidence in T. californicus that hybridization disrupts nuclear/mitochondrial interactions and reduces hybrid fitness, our results suggest that such negative intergenomic epistasis may also increase the production of damaging cellular oxidants; consequently, mtDNA evolution may play a significant role in generating postzygotic isolating barriers among diverging populations.

  5. Effect of procyandin oligomers on oxidative hair damage.

    PubMed

    Kim, Moon-Moo

    2011-02-01

    Procyanidins are a subclass of flavonoids and consist of oligomers of catechin that naturally occur in plants and are known to exert many physiological effects, including antioxidant, anti-inflammatory, and enzyme inhibitory effects. These possible inhibitory effects of the procyanidins were known to involve metal chelation, radical trapping, or direct enzyme binding. The purpose of this study was to investigate the effect of procyandin oligomers on hair damage induced by oxidative stress. In this study, several methods for evaluating oxidative damage in bleached hair are utilized to analyze the protective effect of procyandin oligomers against oxidative hair damage. It was observed that procyanidin oligomers strongly bind to keratin in hair and inhibit the breakdown of hair caused by oxidative damage in an analysis of hair using electrophoresis, transmission electron microscope, and fluorescence dye. These results confirm that procyanidin oligomers can be applicable as a potential candidate to the development of hair care with protective effect on hair damage. © 2011 John Wiley & Sons A/S.

  6. Oxidative damage to rat brain in iron and copper overloads.

    PubMed

    Musacco-Sebio, Rosario; Ferrarotti, Nidia; Saporito-Magriñá, Christian; Semprine, Jimena; Fuda, Julián; Torti, Horacio; Boveris, Alberto; Repetto, Marisa G

    2014-08-01

    This study reports on the acute brain toxicity of Fe and Cu in male Sprague-Dawley rats (200 g) that received 0 to 60 mg kg(-1) (ip) FeCl2 or CuSO4. Brain metal contents and time-responses were determined for rat survival, in situ brain chemiluminescence and phospholipid and protein oxidation products. Metal doses hyperbolically defined brain metal content. Rat survival was 91% and 60% after Fe and Cu overloads. Brain metal content increased from 35 to 114 μg of Fe per g and from 3.6 to 34 μg of Cu per g. Brain chemiluminescence (10 cps cm(-2)) increased 3 and 2 times after Fe and Cu overloads, with half maximal responses (C50) of 38 μg of Fe per g of brain and 15 μg of Cu per g of brain, and with half time responses (t1/2) of 12 h for Fe and 20 h for Cu. Phospholipid peroxidation increased by 56% and 31% with C50 of 40 μg of Fe per g and 20 μg of Cu per g and with t1/2 of 9 h and 14 h. Protein oxidation increased by 45% for Fe with a C50 of 40 μg of Fe per g and 18% for Cu with a C50 of 10 μg of Cu per g and a t1/2 of 12 h for both metals. Fe and Cu brain toxicities are likely mediated by Haber-Weiss type HO˙ formation with subsequent oxidative damage.

  7. Inducible repair of oxidative DNA damage in Escherichia coli.

    PubMed

    Demple, B; Halbrook, J

    Hydrogen peroxide is lethal to many cell types, including the bacterium Escherichia coli. Peroxides yield transient radical species that can damage DNA and cause mutations. Such partially reduced oxygen species are occasionally released during cellular respiration and are generated by lethal and mutagenic ionizing radiation. Because cells live in an environment where the threat of oxidative DNA damage is continual, cellular mechanisms may have evolved to avoid and repair this damage. Enzymes are known which evidently perform these functions. We report here that resistance to hydrogen peroxide toxicity can be induced in E. coli, that this novel induction is specific and occurs, in part, at the level of DNA repair.

  8. Shape-dependent bactericidal activity of copper oxide nanoparticle mediated by DNA and membrane damage

    SciTech Connect

    Laha, Dipranjan; Pramanik, Arindam; Laskar, Aparna; Jana, Madhurya; Pramanik, Panchanan; Karmakar, Parimal

    2014-11-15

    Highlights: • Spherical and sheet shaped copper oxide nanoparticles were synthesized. • Physical characterizations of these nanoparticles were done by TEM, DLS, XRD, FTIR. • They showed shape dependent antibacterial activity on different bacterial strain. • They induced both membrane damage and ROS mediated DNA damage in bacteria. - Abstract: In this work, we synthesized spherical and sheet shaped copper oxide nanoparticles and their physical characterizations were done by the X-ray diffraction, fourier transform infrared spectroscopy, transmission electron microscopy and dynamic light scattering. The antibacterial activity of these nanoparticles was determined on both gram positive and gram negative bacterial. Spherical shaped copper oxide nanoparticles showed more antibacterial property on gram positive bacteria where as sheet shaped copper oxide nanoparticles are more active on gram negative bacteria. We also demonstrated that copper oxide nanoparticles produced reactive oxygen species in both gram negative and gram positive bacteria. Furthermore, they induced membrane damage as determined by atomic force microscopy and scanning electron microscopy. Thus production of and membrane damage are major mechanisms of the bactericidal activity of these copper oxide nanoparticles. Finally it was concluded that antibacterial activity of nanoparticles depend on physicochemical properties of copper oxide nanoparticles and bacterial strain.

  9. Zinc protects HepG2 cells against the oxidative damage and DNA damage induced by ochratoxin A

    SciTech Connect

    Zheng, Juanjuan; Zhang, Yu; Xu, Wentao; Luo, YunBo; Hao, Junran; Shen, Xiao Li; Yang, Xuan; Li, Xiaohong; Huang, Kunlun

    2013-04-15

    Oxidative stress and DNA damage are the most studied mechanisms by which ochratoxin A (OTA) induces its toxic effects, which include nephrotoxicity, hepatotoxicity, immunotoxicity and genotoxicity. Zinc, which is an essential trace element, is considered a potential antioxidant. The aim of this paper was to investigate whether zinc supplement could inhibit OTA-induced oxidative damage and DNA damage in HepG2 cells and the mechanism of inhibition. The results indicated that that exposure of OTA decreased the intracellular zinc concentration; zinc supplement significantly reduced the OTA-induced production of reactive oxygen species (ROS) and decrease in superoxide dismutase (SOD) activity but did not affect the OTA-induced decrease in the mitochondrial membrane potential (Δψ{sub m}). Meanwhile, the addition of the zinc chelator N,N,N′,N′-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) strongly aggravated the OTA-induced oxidative damage. This study also demonstrated that zinc helped to maintain the integrity of DNA through the reduction of OTA-induced DNA strand breaks, 8-hydroxy-2′-deoxyguanosine (8-OHdG) formation and DNA hypomethylation. OTA increased the mRNA expression of metallothionein1-A (MT1A), metallothionein2-A (MT2A) and Cu/Zn superoxide dismutase (SOD1). Zinc supplement further enhanced the mRNA expression of MT1A and MT2A, but it had no effect on the mRNA expression of SOD1 and catalase (CAT). Zinc was for the first time proven to reduce the cytotoxicity of OTA through inhibiting the oxidative damage and DNA damage, and regulating the expression of zinc-associated genes. Thus, the addition of zinc can potentially be used to reduce the OTA toxicity of contaminated feeds. - Highlights: ► OTA decreased the intracellular zinc concentration. ► OTA induced the formation of 8-OHdG in HepG2 cells. ► It was testified for the first time that OTA induced DNA hypomethylation. ► Zinc protects against the oxidative damage and DNA damage induced by

  10. Increased oxidative stress and oxidative DNA damage in non-remission schizophrenia patients.

    PubMed

    Sertan Copoglu, U; Virit, Osman; Hanifi Kokacya, M; Orkmez, Mustafa; Bulbul, Feridun; Binnur Erbagci, A; Semiz, Murat; Alpak, Gokay; Unal, Ahmet; Ari, Mustafa; Savas, Haluk A

    2015-09-30

    Increasing evidence shows that oxidative stress plays a role in the pathophysiology of schizophrenia. But there is not any study which examines the effects of oxidative stress on DNA in schizophrenia patients. Therefore we aimed to assess the oxidative stress levels and oxidative DNA damage in schizophrenia patients with and without symptomatic remission. A total of 64 schizophrenia patients (38 with symptomatic remission and 26 without symptomatic remission) and 80 healthy volunteers were included in the study. 8-hydroxydeoxyguanosine (8-OHdG), total oxidant status (TOS) and total antioxidant status (TAS) were measured in plasma. TOS, oxidative stress index (OSI) and 8-OHdG levels were significantly higher in non-remission schizophrenic (Non-R-Sch) patients than in the controls. TOS and OSI levels were significantly higher in remission schizophrenic (R-Sch) patients than in the controls. TAS level were significantly lower and TOS and OSI levels were significantly higher in R-Sch patients than in Non-R-Sch patients. Despite the ongoing oxidative stress in patients with both R-Sch and Non-R-Sch, oxidative DNA damage was higher in only Non-R-Sch patients compared to controls. It is suggested that oxidative stress can cause the disease via DNA damage, and oxidative stress plays a role in schizophrenia through oxidative DNA damage.

  11. In vivo oxidation and surface damage in retrieved ethylene oxide-sterilized total knee arthroplasties.

    PubMed

    MacDonald, Daniel; Hanzlik, Josa; Sharkey, Peter; Parvizi, Javad; Kurtz, Steven M

    2012-07-01

    Gas sterilization (eg, ethylene oxide [EtO] and gas plasma) was introduced for polyethylene to reduce oxidation due to free radicals occurring during radiation sterilization. Recently, oxidation has been observed in polyethylenes with undetectable levels of free radicals, which were expected to be oxidatively stable. It is unclear whether in vivo oxidation will occur in unirradiated inserts sterilized with EtO. We analyzed the oxidation, mechanical behavior, and surface damage mechanisms of tibial inserts of a single design sterilized using EtO. We collected 20 EtO-sterilized tibial inserts at revision surgeries. We assessed oxidative using Fourier transform infrared spectroscopy and mechanical properties using the small punch test. Surface damage was assessed using damage scoring techniques and micro-CT. Oxidation indexes were low and uniform between the regions. The subtle changes did not affect the mechanical properties of the polymer. The dominant surface damage modes included burnishing, abrasion, and third-body wear. There was no evidence of delamination in the retrievals. The retrieved EtO-sterilized UHMWPE retrievals remained stable with respect to both oxidative and mechanical properties for up to 10 years in vivo. We did observe slight measurable amounts of oxidation in the inserts; however, it was far below levels that would be expected to compromise the strength of the polymer. Due to the stable oxidative and mechanical properties, EtO-sterilized tibial components appear to be an effective alternative to gamma-sterilized inserts, at least in short-term implantations.

  12. Obesity Exacerbates Sepsis-Induced Oxidative Damage in Organs.

    PubMed

    Petronilho, Fabricia; Giustina, Amanda Della; Nascimento, Diego Zapelini; Zarbato, Graciela Freitas; Vieira, Andriele Aparecida; Florentino, Drielly; Danielski, Lucinéia Gainski; Goldim, Mariana Pereira; Rezin, Gislaine Tezza; Barichello, Tatiana

    2016-12-01

    Sepsis progression is linked to the imbalance between reactive oxygen species and antioxidant enzymes. Sepsis affects multiple organs, but when associated with a chronic inflammatory disease, such as obesity, it may be exacerbated. We hypothesized that obesity could aggravate the oxidative damage to peripheral organs of rats submitted to an animal model of sepsis. Male Wistar rats aged 8 weeks received hypercaloric nutrition for 2 months to induce obesity. Sepsis was induced by cecal ligation and puncture (CLP) procedure, and sham-operated rats were considered as control group. The experimental groups were divided into sham + eutrophic, sham + obese, CLP + eutrophic, and CLP + obese. Twelve and 24 h after surgery, oxidative damage to lipids and proteins and superoxide dismutase (SOD) and catalase (CAT) activities were evaluated in the liver, lung, kidney, and heart. The data indicate that obese rats subjected to sepsis present oxidative stress mainly in the lung and liver. This alteration reflected an oxidative damage to lipids and proteins and an imbalance of SOD and CAT levels, especially 24 h after sepsis. It follows that obesity due to its pro-inflammatory phenotype can aggravate sepsis-induced damage in peripheral organs.

  13. Induction of oxidative DNA damage by flavonoids of propolis: its mechanism and implication about antioxidant capacity.

    PubMed

    Tsai, Yi-Chih; Wang, Yi-Hsiang; Liou, Chih-Chiang; Lin, Yu-Cun; Huang, Haimei; Liu, Yin-Chang

    2012-01-13

    Propolis from beehives is commonly used as a home remedy for various purposes including as a topical antiseptic. Despite its antioxidant capacity, propolis induces oxidative DNA damage. In exploring the underlying mechanism, we found that the induction of oxidative DNA damage is attributed to the hydrogen peroxide (H(2)O(2)) produced by propolis. The formation of H(2)O(2) can take place without the participation of cells but requires the presence of transition metal ions such as iron. Flavonoids such as galangin, chrysin, and pinocembrin that are commonly detected in propolis have the capacity to induce oxidative DNA damage, and that capacity correlates with the production of H(2)O(2), suggesting the involvement of flavonoids in propolis in this process. On the basis of these results, we propose that the flavonoids of propolis serve as temporary carriers of electrons received from transition metal ions that are relayed to oxygen molecules to subsequently generate superoxide and H(2)O(2). In addition, propolis induces oxidative DNA damage that is subject to repair, and propolis-treated cells show a lower level of DNA damage level when challenged with another oxidative agent such as amoxicillin. This is reminiscent of an adaptive response that might contribute to the beneficial effects of propolis.

  14. Can graphene oxide cause damage to eyesight?

    PubMed

    Yan, Lu; Wang, Yaping; Xu, Xu; Zeng, Chao; Hou, Jiangping; Lin, Mimi; Xu, Jingzhou; Sun, Fei; Huang, Xiaojie; Dai, Liming; Lu, Fan; Liu, Yong

    2012-06-18

    As graphene becomes one of the most exciting candidates for multifunctional biomedical applications, contact between eyes and graphene-based materials is inevitable. On the other hand, eyes, as a special organ in the human body, have unique advantages to be used for testing new biomedical research and development, such as drug delivery. Intraocular biocompatible studies on graphene-related materials are thus essential. Here, we report our recent studies on intraocular biocompatibility and cytotoxicity of graphene oxide (GO) both in vitro and in vivo. The successful preparation of GO nanosheets was confirmed using atomic force microscopy, contact angle analyzer, Fourier transform infrared spectroscopy, and Raman spectroscopy. The influence of GO on human retinal pigment epithelium (RPE) cells in terms of the cell morphology, viability, membrane integrity, and apoptosis was investigated using various techniques, including optical micrography, cell counting kit-8 (CCK-8) assay, lactate dehydrogenase (LDH) assay, and apoptosis assay. The addition of GO had little influence on cell morphology, but the change was visible after long-time culturing. RPE cells showed higher than 60% cell viability by CCK-8 assay in GO solutions and less than 8% LDH release, although a small amount of apoptosis (1.5%) was observed. In vitro results suggested good biocompatibility of GO to RPE cells with slight adverse influence, on the cell viability and morphology in long-time periods, along with aggregation of GO. Thus, some further studies are needed to clarify the cytotoxicity mechanism of GO. GO intravitreally injected eyes showed few changes in eyeball appearance, intraocular pressure (IOP), eyesight, and histological photos. Our results suggested that GO did not cause any significant toxicity to the cell growth and proliferation. Intravitreal injection of GO into rabbits' eyes did not lead to much change in the eyeball appearance, IOP, electroretinogram, and histological examination.

  15. Acetaldehyde-induced mitochondrial dysfunction sensitizes hepatocytes to oxidative damage.

    PubMed

    Farfán Labonne, Blanca Eugenia; Gutiérrez, Mario; Gómez-Quiroz, Luis Enrique; Konigsberg Fainstein, Mina; Bucio, Leticia; Souza, Verónica; Flores, Oscar; Ortíz, Victor; Hernández, Elizabeth; Kershenobich, David; Gutiérrez-Ruíz, María Concepción

    2009-12-01

    Acetaldehyde (Ac), the main metabolite of ethanol oxidation, is a very reactive compound involved in alcohol-induced liver damage. In the present work, we studied the effect of Ac in mitochondria functionality. Mitochondria from Wistar rats were isolated and treated with Ac. Ac decreased respiratory control by 50% which was associated with a decrease in adenosine triphosphate content (28.5%). These results suggested that Ac could be inducing changes in cell redox status. We determined protein oxidation, superoxide dismutase (SOD) activity, and glutathione ratio, indicating that Ac induced an enhanced oxidation of proteins and a decrease in SOD activity (90%) and glutathione/oxidized GSH ratio (36%). The data suggested that Ac-induced oxidative stress mediated by mitochondria dysfunction can lead to cell sensitization and to a second oxidative challenge. We pretreated hepatocytes with Ac followed by treatment with antimycin A, and this experiment revealed a noticeable decrease in cell viability, determined by neutral red assay, in comparison with cells treated with Ac alone. Our data demonstrate that Ac impairs mitochondria functionality generating oxidative stress that sensitizes cells to a second damaging signal contributing to the development of alcoholic liver disease.

  16. Anti- and pro-oxidant effects of (+)-catechin on hemoglobin-induced protein oxidative damage.

    PubMed

    Lu, Naihao; Chen, Puqing; Yang, Qin; Peng, Yi-Yuan

    2011-06-01

    Evidence to support the role of heme proteins as major inducers of oxidative damage is increasingly present. Flavonoids have been widely used to ameliorate oxidative damage in vivo and in vitro, where the mechanism of this therapeutic action was usually dependent on their anti-oxidant effects. In this study, we investigated the influence of (+)-catechin, a polyphenol identified in tea, cocoa, and red wine, on hemoglobin-induced protein oxidative damage. It was found that (+)-catechin had the capacities to act as a free radical scavenger and reducing agent to remove cytotoxic ferryl hemoglobin, demonstrating apparent anti-oxidant activities. However, the presence of (+)-catechin surprisingly promoted hemoglobin-induced protein oxidation, which was probably due to the ability of this anti-oxidant to rapidly trigger the oxidative degradation of normal hemoglobin. In addition, hemoglobin-H2O2-induced protein carbonyl formation was significantly enhanced by (+)-catechin at lower concentrations, while it was efficiently inhibited when higher concentrations were used. These novel results showed that the dietary intake and therapeutic use of catechins might possess pro-oxidant activity through aggravating hemoglobin-related oxidative damage. The dual effects on hemoglobin redox reactions may provide new insights into the physiological implications of tea extract and wine (catechins) with cellular heme proteins.

  17. Alternative Interventions to Prevent Oxidative Damage following Ischemia/Reperfusion

    PubMed Central

    Rodríguez-Lara, Simón Quetzalcoatl; Ramírez-Lizardo, Ernesto Javier; Totsuka-Sutto, Sylvia Elena; Castillo-Romero, Araceli; García-Cobián, Teresa Arcelia

    2016-01-01

    Ischemia/reperfusion (I/R) lesions are a phenomenon that occurs in multiple pathological states and results in a series of events that end in irreparable damage that severely affects the recovery and health of patients. The principal therapeutic approaches include preconditioning, postconditioning, and remote ischemic preconditioning, which when used separately do not have a great impact on patient mortality or prognosis. Oxidative stress is known to contribute to the damage caused by I/R; however, there are no pharmacological approaches to limit or prevent this. Here, we explain the relationship between I/R and the oxidative stress process and describe some pharmacological options that may target oxidative stress-states. PMID:28116037

  18. Oxidative damage and cell-programmed death induced in Zea mays L. by allelochemical stress.

    PubMed

    Ciniglia, Claudia; Mastrobuoni, Francesco; Scortichini, Marco; Petriccione, Milena

    2015-05-01

    The allelochemical stress on Zea mays was analyzed by using walnut husk washing waters (WHWW), a by-product of Juglans regia post-harvest process, which possesses strong allelopathic potential and phytotoxic effects. Oxidative damage and cell-programmed death were induced by WHWW in roots of maize seedlings. Treatment induced ROS burst, with excess of H2O2 content. Enzymatic activities of catalase were strongly increased during the first hours of exposure. The excess in malonildialdehyde following exposure to WHWW confirmed that oxidative stress severely damaged maize roots. Membrane alteration caused a decrease in NADPH oxidase activity along with DNA damage as confirmed by DNA laddering. The DNA instability was also assessed through sequence-related amplified polymorphism assay, thus suggesting the danger of walnut processing by-product and focusing the attention on the necessity of an efficient treatment of WHWW.

  19. [Nitric oxide production in plants].

    PubMed

    Małolepsza, Urszula

    2007-01-01

    There are still many controversial observations and opinions on the cellular/subcellular localization and sources of endogenous nitric oxide synthesis in plant cells. NO can be produced in plants by non-enzymatic and enzymatic systems depending on plant species, organ or tissue as well as on physiological state of the plant and changing environmental conditions. The best documented reactions in plant that contribute to NO production are NO production from nitrite as a substrate by cytosolic (cNR) and membrane bound (PM-NR) nitrate reductases (NR), and NO production by several arginine-dependent nitric oxide synthase-like activities (NOS). The latest papers indicate that mitochondria are an important source of arginine- and nitrite-dependent NO production in plants. There are other potential enzymatic sources of NO in plants including xanthine oxidoreductase, peroxidase, cytochrome P450.

  20. Maternal diabetes triggers DNA damage and DNA damage response in neurulation stage embryos through oxidative stress.

    PubMed

    Dong, Daoyin; Yu, Jingwen; Wu, Yanqing; Fu, Noah; Villela, Natalia Arias; Yang, Peixin

    2015-11-13

    DNA damage and DNA damage response (DDR) in neurulation stage embryos under maternal diabetes conditions are not well understood. The purpose of this study was to investigate whether maternal diabetes and high glucose in vitro induce DNA damage and DDR in the developing embryo through oxidative stress. In vivo experiments were conducted by mating superoxide dismutase 1 (SOD1) transgenic male mice with wild-type (WT) female mice with or without diabetes. Embryonic day 8.75 (E8.75) embryos were tested for the DNA damage markers, phosphorylated histone H2A.X (p-H2A.X) and DDR signaling intermediates, including phosphorylated checkpoint 1 (p-Chk1), phosphorylated checkpoint 2 (p-Chk2), and p53. Levels of the same DNA damage markers and DDR signaling intermediates were also determined in the mouse C17.2 neural stem cell line. Maternal diabetes and high glucose in vitro significantly increased the levels of p-H2A.X. Levels of p-Chk1, p-Chk2, and p53, were elevated under both maternal diabetic and high glucose conditions. SOD1 overexpression blocked maternal diabetes-induced DNA damage and DDR in vivo. Tempol, a SOD1 mimetic, diminished high glucose-induced DNA damage and DDR in vitro. In conclusion, maternal diabetes and high glucose in vitro induce DNA damage and activates DDR through oxidative stress, which may contribute to the pathogenesis of diabetes-associated embryopathy.

  1. Large-brained birds suffer less oxidative damage.

    PubMed

    Vágási, C I; Vincze, O; Pătraş, L; Osváth, G; Marton, A; Bărbos, L; Sol, D; Pap, P L

    2016-10-01

    Large brains (relative to body size) might confer fitness benefits to animals. Although the putative costs of well-developed brains can constrain the majority of species to modest brain sizes, these costs are still poorly understood. Given that the neural tissue is energetically expensive and demands antioxidants, one potential cost of developing and maintaining large brains is increased oxidative stress ('oxidation exposure' hypothesis). Alternatively, because large-brained species exhibit slow-paced life histories, they are expected to invest more into self-maintenance such as an efficacious antioxidative defence machinery ('oxidation avoidance' hypothesis). We predict decreased antioxidant levels and/or increased oxidative damage in large-brained species in case of oxidation exposure, and the contrary in case of oxidation avoidance. We address these contrasting hypotheses for the first time by means of a phylogenetic comparative approach based on an unprecedented data set of four redox state markers from 85 European bird species. Large-brained birds suffered less oxidative damage to lipids (measured as malondialdehyde levels) and exhibited higher total nonenzymatic antioxidant capacity than small-brained birds, whereas uric acid and glutathione levels were independent of brain size. These results were not altered by potentially confounding variables and did not depend on how relative brain size was quantified. Our findings partially support the 'oxidation avoidance' hypothesis and provide a physiological explanation for the linkage of large brains with slow-paced life histories: reduced oxidative stress of large-brained birds can secure brain functionality and healthy life span, which are integral to their lifetime fitness and slow-paced life history. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

  2. NDE for Characterizing Oxidation Damage in Reinforced Carbon-Carbon

    NASA Technical Reports Server (NTRS)

    Roth, Don J.; Rauser, Richard W.; Jacobson, nathan S.; Wincheski, Russell A.; Walker, James L.; Cosgriff, Laura A.

    2009-01-01

    In this study, coated reinforced carbon-carbon (RCC) samples of similar structure and composition as that from the NASA space shuttle orbiter s thermal protection system were fabricated with slots in their coating simulating craze cracks. These specimens were used to study oxidation damage detection and characterization using NDE methods. These specimens were heat treated in air at 1143 and 1200 C to create cavities in the carbon substrate underneath the coating as oxygen reacted with the carbon and resulted in its consumption. The cavities varied in diameter from approximately 1 to 3 mm. Single-sided NDE methods were used since they might be practical for on-wing inspection, while x-ray micro-computed tomography (CT) was used to measure cavity sizes in order to validate oxidation models under development for carbon-carbon materials. An RCC sample having a naturally-cracked coating and subsequent oxidation damage was also studied with x-ray micro-CT. This effort is a follow-on study to one that characterized NDE methods for assessing oxidation damage in an RCC sample with drilled holes in the coating. The results of that study are briefly reviewed in this article as well. Additionally, a short discussion on the future role of simulation to aid in these studies is provided.

  3. Guarding chromosomes from oxidative DNA damage to the very end.

    PubMed

    Tan, Rong; Lan, Li

    2016-07-01

    The ends of each chromosome are capped by the telomere assembly to protect chromosomal integrity from telomere attrition and DNA damage. In response to DNA damage, DNA repair factors are enriched at damage sites by a sophisticated signaling and recruitment cascade. However, DNA damage response at telomeres is different from non-telomeric region of genomic DNA due to specialized sequences and structures of the telomeres. In the course of normal DNA replication or DNA damage repair, both the telomere shelterin protein complex and the condensed telomeric chromatin structure in mammalian cells are modified to protect telomeres from exposing free DNA ends which are subject to both telemere shortening and chromosome end fusion. Initiation of either homologous recombination or non-homologous end joint repair at telomeres requires disassembling and/or post-translational modifications of the shelterin complex and telomeric chromatin. In addition, cancer cells utilize distinct mechanisms to maintain telomere length and cell survival upon damage. In this review, we summarize current studies that focus on telomere end protection and telomere DNA repair using different methodologies to model telomere DNA damage and disruption. These include genetic ablation of sheltering proteins, targeting endonuclease to telomeres, and delivering oxidative damage directly. These different approaches, when combined, offer better understanding of the mechanistic differences in DNA damage response between telomeric and genomic DNA, which will provide new hope to identify potential cancer therapeutic targets to curtail cancer cell proliferation via induction of telomere dysfunctions. © The Author 2016. Published by Oxford University Press on behalf of the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Measurement of oxidatively induced DNA damage and its repair, by mass spectrometric techniques.

    PubMed

    Dizdaroglu, M; Coskun, E; Jaruga, P

    2015-05-01

    Oxidatively induced damage caused by free radicals and other DNA-damaging agents generate a plethora of products in the DNA of living organisms. There is mounting evidence for the involvement of this type of damage in the etiology of numerous diseases including carcinogenesis. For a thorough understanding of the mechanisms, cellular repair, and biological consequences of DNA damage, accurate measurement of resulting products must be achieved. There are various analytical techniques, with their own advantages and drawbacks, which can be used for this purpose. Mass spectrometric techniques with isotope dilution, which include gas chromatography (GC) and liquid chromatography (LC), provide structural elucidation of products and ascertain accurate quantification, which are absolutely necessary for reliable measurement. Both gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-mass spectrometry (LC-MS), in single or tandem versions, have been used for the measurement of numerous DNA products such as sugar and base lesions, 8,5'-cyclopurine-2'-deoxynucleosides, base-base tandem lesions, and DNA-protein crosslinks, in vitro and in vivo. This article reviews these techniques and their applications in the measurement of oxidatively induced DNA damage and its repair.

  5. Different Effects of CSA and CSB Deficiency on Sensitivity to Oxidative DNA Damage

    PubMed Central

    de Waard, Harm; de Wit, Jan; Andressoo, Jaan-Olle; van Oostrom, Conny T. M.; Riis, Bente; Weimann, Allan; Poulsen, Henrik E.; van Steeg, Harry; Hoeijmakers, Jan H. J.; van der Horst, Gijsbertus T. J.

    2004-01-01

    Mutations in the CSA and CSB genes cause Cockayne syndrome, a rare inherited disorder characterized by UV sensitivity, severe neurological abnormalities, and progeriod symptoms. Both gene products function in the transcription-coupled repair (TCR) subpathway of nucleotide excision repair (NER), providing the cell with a mechanism to remove transcription-blocking lesions from the transcribed strands of actively transcribed genes. Besides a function in TCR of NER lesions, a role of CSB in (transcription-coupled) repair of oxidative DNA damage has been suggested. In this study we used mouse models to compare the effect of a CSA or a CSB defect on oxidative DNA damage sensitivity at the levels of the cell and the intact organism. In contrast to CSB−/− mouse embryonic fibroblasts (MEFs), CSA−/− MEFs are not hypersensitive to gamma-ray or paraquat treatment. Similar results were obtained for keratinocytes. In contrast, both CSB−/− and CSA−/− embryonic stem cells show slight gamma-ray sensitivity. Finally, CSB−/− but not CSA−/− mice fed with food containing di(2-ethylhexyl)phthalate (causing elevated levels of oxidative DNA damage in the liver) show weight reduction. These findings not only uncover a clear difference in oxidative DNA damage sensitivity between CSA- and CSB-deficient cell lines and mice but also show that sensitivity to oxidative DNA damage is not a uniform characteristic of Cockayne syndrome. This difference in the DNA damage response between CSA- and CSB-deficient cells is unexpected, since until now no consistent differences between CSA and CSB patients have been reported. We suggest that the CSA and CSB proteins in part perform separate roles in different DNA damage response pathways. PMID:15340056

  6. In situ analysis of 8-oxo-7,8-dihydro-2'-deoxyguanosine oxidation reveals sequence- and agent-specific damage spectra.

    PubMed

    Lim, Kok Seong; Cui, Liang; Taghizadeh, Koli; Wishnok, John S; Chan, Wan; DeMott, Michael S; Babu, I Ramesh; Tannenbaum, Steven R; Dedon, Peter C

    2012-10-31

    Guanine is a major target for oxidation in DNA, with 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) as a major product. 8-oxodG is itself significantly more susceptible to oxidation than guanine, with the resulting damage consisting of more than 10 different products. This complexity has hampered efforts to understand the determinants of biologically relevant DNA oxidation chemistry. To address this problem, we have developed a high mass accuracy mass spectrometric method to quantify oxidation products arising site specifically in DNA. We applied this method to quantify the role of sequence context in defining the spectrum of damage products arising from oxidation of 8-oxodG by two oxidants: nitrosoperoxycarbonate (ONOOCO(2)(-)), a macrophage-derived chemical mediator of inflammation, and the classical one-electron oxidant, riboflavin-mediated photooxidation. The results reveal the predominance of dehydroguanidinohydantoin (DGh) in 8-oxodG oxidation by both oxidants. While the relative quantities of 8-oxodG oxidation products arising from ONOOCO(2)(-) did not vary as a function of sequence context, products of riboflavin-mediated photooxidation of 8-oxodG were highly sequence dependent. Several of the 8-oxodG oxidation products underwent hydrolytic conversion to new products with half-lives of 2-7 h. The results have implications for understanding the chemistry of DNA oxidation and the biological response to the damage, with DNA damage recognition and repair systems faced with a complex and dynamic set of damage targets.

  7. Mitochondrial oxidative stress significantly influences atherogenic risk and cytokine-induced oxidant production.

    PubMed

    Harrison, Corey M; Pompilius, Melissa; Pinkerton, Kent E; Ballinger, Scott W

    2011-05-01

    Oxidative stress associated with cardiovascular disease (CVD) risk factors contributes to disease development. However, less is known whether specific subcellular components play a role in disease susceptibility. In this regard, it has been previously reported that vascular mitochondrial damage and dysfunction are associated with atherosclerosis. However, no studies have determined whether altered mitochondrial oxidant production directly influences atherogenic susceptibility and response in primary cells to atherogenic factors such as tumor necrosis factor-α (TNF-α). We undertook this study to determine whether increased mitochondrial oxidant production affects atherosclerotic lesion development associated with CVD risk factor exposure and endothelial cell response to TNF-α. We assessed atherosclerotic lesion formation, oxidant stress, and mitochondrial DNA damage in male apolipoprotein E (apoE)-null mice with normal and decreased levels of mitochondrial superoxide dismutase-2 (SOD2; apoE(-/-) and apoE(-/-), SOD2(+/-), respectively) exposed to environmental tobacco smoke or filtered air. Atherogenesis, oxidative stress, and mitochondrial damage were significantly higher in apoE(-/-), SOD2(+/-) mice than in apoE(-/-) controls. Furthermore, experiments with small interfering RNA in endothelial cells revealed that decreased SOD2 activity increased TNF-α-mediated cellular oxidant levels compared with controls. Endogenous mitochondrial oxidative stress is an important CVD risk factor that can modulate atherogenesis and cytokine-induced endothelial cell oxidant generation. Consequently, CVD risk factors that induce mitochondrial damage alter cellular response to endogenous atherogenic factors, increasing disease susceptibility.

  8. Oxidative stress and mitochondrial damage in coronary artery bypass graft surgery: effects of antioxidant treatments.

    PubMed

    Milei, J; Ferreira, R; Grana, D R; Boveris, A

    2001-01-01

    We examined antioxidant actions in 73 patients undergoing coronary artery surgery by assessing mitochondrial damage and oxidative stress in ventricular biopsies obtained at preischemia and postreperfusion. Those patients who received antioxidant therapy benefited by less oxidative stress and mitochondrial damage.

  9. Oxidative damage to poultry: from farm to fork.

    PubMed

    Estévez, M

    2015-06-01

    Poultry and poultry meat are particularly susceptible to oxidative reactions. Oxidation processes have been for decades the focus of animal and meat scientists owing to the negative impact of these reactions on animal growth, performance, and food quality. Lipid oxidation has been recognized a major threat to the quality of processed poultry products. The recent discoveries on the occurrence of protein oxidation in muscle foods have increased the scientific and technological interest in a topic that broadens the horizons of food biochemistry into innovative fields. Furthermore, in recent years we have witnessed a growing interest in consumers on the impact of diet and oxidation on health and aging. Hence, the general description of oxidative reactions as harmful phenomena goes beyond the actual impact on animal production and food quality and reaches the potential influence of oxidized foods on consumer health. Likewise, the current antioxidant strategies aim for the protection of the living tissues, the food systems, and a potential health benefit in the consumer upon ingestion. Along these lines, the application of phytochemicals and other microelements (Se, Cu) with antioxidant potential in the feeds or directly in the meat product are strategies of substantial significance. The present paper reviews in a concise manner the most relevant and novel aspects of the mechanisms and consequences of oxidative reactions in poultry and poultry meat, and describes current antioxidant strategies against these undesirable reactions. © 2015 Poultry Science Association Inc.

  10. Reduction in oxidatively generated DNA damage following smoking cessation

    PubMed Central

    2011-01-01

    Background Cigarette smoking is a known cause of cancer, and cancer may be in part due to effects of oxidative stress. However, whether smoking cessation reverses oxidatively induced DNA damage unclear. The current study sought to examine the extent to which three DNA lesions showed significant reductions after participants quit smoking. Methods Participants (n = 19) in this study were recruited from an ongoing 16-week smoking cessation clinical trial and provided blood samples from which leukocyte DNA was extracted and assessed for 3 DNA lesions (thymine glycol modification [d(TgpA)]; formamide breakdown of pyrimidine bases [d(TgpA)]; 8-oxo-7,8-dihydroguanine [d(Gh)]) via liquid chromatography tandem mass spectrometry (LC-MS/MS). Change in lesions over time was assessed using generalized estimating equations, controlling for gender, age, and treatment condition. Results Overall time effects for the d(TgpA) (χ2(3) = 8.068, p < 0.045), d(PfpA) (χ2(3) = 8.477, p < 0.037), and d(Gh) (χ2(3) = 37.599, p < 0.001) lesions were seen, indicating levels of each decreased significantly after CO-confirmed smoking cessation. The d(TgpA) and d(PfpA) lesions show relatively greater rebound at Week 16 compared to the d(Gh) lesion (88% of baseline for d(TgpA), 64% of baseline for d(PfpA), vs 46% of baseline for d(Gh)). Conclusions Overall, results from this analysis suggest that cigarette smoking contributes to oxidatively induced DNA damage, and that smoking cessation appears to reduce levels of specific damage markers between 30-50 percent in the short term. Future research may shed light on the broader array of oxidative damage influenced by smoking and over longer durations of abstinence, to provide further insights into mechanisms underlying carcinogenesis. PMID:21569419

  11. Aloin Protects Skin Fibroblasts from Heat Stress-Induced Oxidative Stress Damage by Regulating the Oxidative Defense System.

    PubMed

    Liu, Fu-Wei; Liu, Fu-Chao; Wang, Yu-Ren; Tsai, Hsin-I; Yu, Huang-Ping

    2015-01-01

    Oxidative stress is commonly involved in the pathogenesis of skin damage induced by environmental factors, such as heat stress. Skin fibroblasts are responsible for the connective tissue regeneration and the skin recovery from injury. Aloin, a bioactive compound in Aloe vera, has been reported to have various pharmacological activities, such as anti-inflammatory effects. The aim of this study was to investigate the protective effect of aloin against heat stress-mediated oxidative stress in human skin fibroblast Hs68 cells. Hs68 cells were first incubated at 43°C for 30 min to mimic heat stress. The study was further examined if aloin has any effect on heat stress-induced oxidative stress. We found that aloin protected Hs68 cells against heat stress-induced damage, as assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase assay. Aloin protected Hs68 cells by regulating reactive oxygen species production and increasing the levels of glutathione, cytosolic and mitochondrial superoxide dismutase. Aloin also prevented the elevation of thiobarbituric acid reactive substances and the reduction of 8-OH-dG induced by heat stress. These results indicated that aloin protected human skin fibroblasts from heat stress-induced oxidative stress damage by regulating the oxidative defense system.

  12. Aloin Protects Skin Fibroblasts from Heat Stress-Induced Oxidative Stress Damage by Regulating the Oxidative Defense System

    PubMed Central

    Wang, Yu-Ren; Tsai, Hsin-I; Yu, Huang-Ping

    2015-01-01

    Oxidative stress is commonly involved in the pathogenesis of skin damage induced by environmental factors, such as heat stress. Skin fibroblasts are responsible for the connective tissue regeneration and the skin recovery from injury. Aloin, a bioactive compound in Aloe vera, has been reported to have various pharmacological activities, such as anti-inflammatory effects. The aim of this study was to investigate the protective effect of aloin against heat stress-mediated oxidative stress in human skin fibroblast Hs68 cells. Hs68 cells were first incubated at 43°C for 30 min to mimic heat stress. The study was further examined if aloin has any effect on heat stress-induced oxidative stress. We found that aloin protected Hs68 cells against heat stress-induced damage, as assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase assay. Aloin protected Hs68 cells by regulating reactive oxygen species production and increasing the levels of glutathione, cytosolic and mitochondrial superoxide dismutase. Aloin also prevented the elevation of thiobarbituric acid reactive substances and the reduction of 8-OH-dG induced by heat stress. These results indicated that aloin protected human skin fibroblasts from heat stress-induced oxidative stress damage by regulating the oxidative defense system. PMID:26637174

  13. Overloaded training increases exercise-induced oxidative stress and damage.

    PubMed

    Palazzetti, Stephane; Richard, Marie-Jeanne; Favier, Alain; Margaritis, Irene

    2003-08-01

    We hypothesized that overloaded training (OT) in triathlon would induce oxidative stress and damage on muscle and DNA. Nine male triathletes and 6 male sedentary subjects participated in this study. Before and after a 4-week OT, triathletes exercised for a duathlon. Blood ratio of reduced vs. oxidized glutathione (GSH/GSSG), plasma thiobarbituric acid reactive substances (TBARS), leukocyte DNA damage, creatine kinase (CK), and CK-MB mass in plasma, erythrocyte superoxide dismutase (SOD) activity, erythrocyte and plasma glutathione peroxidase (GSH-Px) activities, and plasma total antioxidant status (TAS) were measured before and after OT in pre- and postexercise situations. Triathletes were overloaded in response to OT. In rest conditions, OT induced plasma GSH-Px activity increase and plasma TAS decrease (both p < 0.05). In exercise conditions, OT resulted in higher exercise-induced variations of blood GSH/GSSG ratio, TBARS level (both p < 0.05), and CK-MB mass (p < 0.01) in plasma; and decreased TAS response (p < 0.05). OT could compromise the antioxidant defense mechanism with respect to exercise-induced response. The resulting increased exercise-induced oxidative stress and further cellular susceptibility to damage needs more study.

  14. Oxidatively generated DNA/RNA damage in psychological stress states.

    PubMed

    Jørgensen, Anders

    2013-07-01

    Both non-pathological psychological stress states and mental disorders are associated with molecular, cellular and epidemiological signs of accelerated aging. Oxidative stress on nucleic acids is a critical component of cellular and organismal aging, and a suggested pathogenic mechanism in several age-related somatic disorders. The overall aim of the PhD project was to investigate the relation between psychopathology, psychological stress, stress hormone secretion and oxidatively generated DNA and RNA damage, as measured by the urinary excretion of markers of whole-body DNA/RNA oxidation (8-oxodG and 8-oxoGuo, respectively). The main hypothesis was that psychological stress states are associated with increased DNA/RNA damage from oxidation. In a study of 40 schizophrenia patients and 40 healthy controls matched for age and gender, we found that 8-oxodG/8-oxoGuo excretion was increased in schizophrenia patients, providing a possible molecular link between schizophrenia and its associated signs of accelerated aging. We found no association between psychopathology, perceived stress or cortisol secretion and 8-oxodG/8-oxoGuo excretion in the patients. In the controls, there were positive correlations between 8-oxodG/8-ocoGuo excretion and 9AM plasma cortisol, but no associations to perceived stress. In an animal study of experimentally induced chronic stress performed in metabolism cages, we found no increase in urinary 8-oxodG/8-oxoGuo or cerebral (hippocampal and frontal cortex) levels of oxidatively generated nucleic acid damage. However, there was a trend towards an increased expression of genes involved in DNA repair, possibly reflecting a compensatory mechanism. In a study of 220 elderly, mostly healthy individuals from the Italian InChianti cohort, we found a significant association between the 24 h urinary cortisol excretion and the excretion of 8-oxodG/8-oxoGuo, determined in the same samples. Collectively, the studies could not confirm an association between

  15. Tyrosine-dependent oxidative DNA damage induced by carcinogenic tetranitromethane.

    PubMed

    Murata, Mariko; Kurimoto, Saori; Kawanishi, Shosuke

    2006-10-01

    Tetranitromethane (TNM) is used as an oxidizer in rocket propellants and explosives and as an additive to increase the cetane number of diesel fuel. TNM was reported to induce pulmonary adenocarcinomas and squamous cell carcinomas in mice and rats. However, the mechanisms underlying carcinogenesis induced by TNM has not yet been clarified. We previously revealed that nitroTyr and nitroTyr-containing peptides caused Cu(II)-dependent DNA damage in the presence of P450 reductase, which is considered to yield nitroreduction. Since TNM is a reagent for nitration of Tyr in proteins and peptides, we have hypothesized that TNM-treated Tyr and Tyr-containing peptides induce DNA damage by the modification of Tyr. We examined DNA damage induced by TNM-treated amino acids or peptides using (32)P-5'-end-labeled DNA fragments obtained from the human p53 tumor suppressor gene and the c-Ha-ras-1 protooncogene. TNM-treated Tyr and Lys-Tyr-Lys induced DNA damage including the formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine in the presence of Cu(II) and NADH. DNA damage was inhibited by catalase and bathocuproine, indicating the involvement of H(2)O(2) and Cu(I). The cytosine residue of the ACG sequence complementary to codon 273, well-known hotspots of the p53 gene, was cleaved with piperidine and Fpg treatments. On the other hand, nitroTyr and Lys-nitroTyr-Lys did not induce DNA damage in the presence of Cu(II) and NADH. Time-of-flight mass spectrometry confirmed that reactions between Lys-Tyr-Lys and TNM yielded not only Lys-nitroTyr-Lys but also Lys-nitrosoTyr-Lys. Therefore, it is speculated that the nitrosotyrosine residue can induce oxidative DNA damage in the presence of Cu(II) and NADH. It is concluded that Tyr-dependent DNA damage may play an important role in the carcinogenicity of TNM. TNM is a new type of carcinogen that induces DNA damage not by itself but via Tyr modification.

  16. Radiation damage of gallium arsenide production cells

    NASA Technical Reports Server (NTRS)

    Mardesich, N.; Garlick, G. F. J.

    1987-01-01

    High-efficiency gallium arsenide cells, made by the liquid epitaxy method (LPE), have been irradiated with 1-MeV electrons up to fluences of 10 to the 16th e/sq cm. Measurements have been made of cell spectral response and dark and light-excited current-voltage characteristics and analyzed using computer-based models to determine underlying parameters such as damage coefficients. It is possible to use spectral response to sort out damage effects in the different cell component layers. Damage coefficients are similar to other reported in the literature for the emitter and buffer (base). However, there is also a damage effect in the window layer and possibly at the window emitter interface similar to that found for proton-irradiated liquid-phase epitaxy-grown cells. Depletion layer recombination is found to be less than theoretically expected at high fluence.

  17. Measurement of oxidatively generated base damage in cellular DNA.

    PubMed

    Cadet, Jean; Douki, Thierry; Ravanat, Jean-Luc

    2011-06-03

    This survey focuses on the critical evaluation of the main methods that are currently available for monitoring single and complex oxidatively generated damage to cellular DNA. Among chromatographic methods, HPLC-ESI-MS/MS and to a lesser extent HPLC-ECD which is restricted to a few electroactive nucleobases and nucleosides are appropriate for measuring the formation of single and clustered DNA lesions. Such methods that require optimized protocols for DNA extraction and digestion are sensitive enough for measuring base lesions formed under conditions of severe oxidative stress including exposure to ionizing radiation, UVA light and high intensity UVC laser pulses. In contrast application of GC-MS and HPLC-MS methods that are subject to major drawbacks have been shown to lead to overestimated values of DNA damage. Enzymatic methods that are based on the use of DNA repair glycosylases in order to convert oxidized bases into strand breaks are suitable, even if they are far less specific than HPLC methods, to deal with low levels of single modifications. Several other methods including immunoassays and (32)P-postlabeling methods that are still used suffer from drawbacks and therefore are not recommended. Another difficult topic is the measurement of oxidatively generated clustered DNA lesions that is currently achieved using enzymatic approaches and that would necessitate further investigations.

  18. Homologous recombination is required for recovery from oxidative DNA damage.

    PubMed

    Hayashi, Michio; Umezu, Keiko

    2017-04-03

    We have been studying the genetic events, including chromosome loss, chromosome rearrangements and intragenic point mutations, that are responsible for the deletion of a URA3 marker in a loss of heterozygosity (LOH) assay in the yeast Saccharomycess cerevisiae. With this assay, we previously showed that homologous recombination plays an important role in genome maintenance in response to DNA lesions that occur spontaneously in normally growing cells. Here, to investigate DNA lesions capable of triggering homologous recombination, we examined the effects of oxidative stress, a prominent cause of endogenous DNA damage, on LOH events. Treatment of log-phase cells with H2O2 first caused growth arrest and then, during the subsequent recovery, chromosome loss and various chromosome rearrangements were induced more than 10-fold. Further analysis of the rearrangements showed that gene conversion was strongly induced, approximately 100 times more frequently than in untreated cells. Consistent with these results, two diploid strains deficient for homologous recombination, rad52Δ/rad52Δ and rad51Δ/rad51Δ, were sensitive to H2O2 treatment. In addition, chromosome DNA breaks were detected in H2O2-treated cells using pulsed-field gel electrophoresis. Altogether, these results suggest that oxidative stress induced recombinogenic lesions on chromosomes, which then triggered homologous recombination leading to chromosome rearrangements, and that this response contributed to the survival of cells afflicted by oxidative DNA damage. We therefore conclude that homologous recombination is required for the recovery of cells from oxidative stress.

  19. Choreography of oxidative damage repair in mammalian genomes.

    PubMed

    Mitra, Sankar; Izumi, Tadahide; Boldogh, Istvan; Bhakat, Kishor K; Hill, Jeff W; Hazra, Tapas K

    2002-07-01

    The lesions induced by reactive oxygen species in both nuclear and mitochondrial genomes include altered bases, abasic (AP) sites, and single-strand breaks, all repaired primarily via the base excision repair (BER) pathway. Although the basic BER process (consisting of five sequential steps) could be reconstituted in vitro with only four enzymes, it is now evident that repair of oxidative damage, at least in mammalian cell nuclei, is more complex, and involves a number of additional proteins, including transcription- and replication-associated factors. These proteins may be required in sequential repair steps in concert with other cellular changes, starting with nuclear targeting of the early repair enzymes in response to oxidative stress, facilitation of lesion recognition, and access by chromatin unfolding via histone acetylation, and formation of metastable complexes of repair enzymes and other accessory proteins. Distinct, specific subclasses of protein complexes may be formed for repair of oxidative lesions in the nucleus in transcribed vs. nontranscribed sequences in chromatin, in quiescent vs. cycling cells, and in nascent vs. parental DNA strands in replicating cells. Characterizing the proteins for each repair subpathway, their signaling-dependent modifications and interactions in the nuclear as well as mitochondrial repair complexes, will be a major focus of future research in oxidative damage repair.

  20. Nitric Oxide Production in Plants

    PubMed Central

    Planchet, Elisabeth

    2006-01-01

    There is now general agreement that nitric oxide (NO) is an important and almost universal signal in plants. Nevertheless, there are still many controversial observations and opinions on the importance and function of NO in plants. Partly, this may be due to the difficulties in detecting and even more in quantifying NO. Here, we summarize major pathways of NO production in plants, and briefly discuss some methodical problems. PMID:19521475

  1. Plasmalogen phospholipids protect internodal myelin from oxidative damage.

    PubMed

    Luoma, Adrienne M; Kuo, Fonghsu; Cakici, Ozgur; Crowther, Michelle N; Denninger, Andrew R; Avila, Robin L; Brites, Pedro; Kirschner, Daniel A

    2015-07-01

    Reactive oxygen species (ROS) are implicated in a range of degenerative conditions, including aging, neurodegenerative diseases, and neurological disorders. Myelin is a lipid-rich multilamellar sheath that facilitates rapid nerve conduction in vertebrates. Given the high energetic demands and low antioxidant capacity of the cells that elaborate the sheaths, myelin is considered intrinsically vulnerable to oxidative damage, raising the question whether additional mechanisms prevent structural damage. We characterized the structural and biochemical basis of ROS-mediated myelin damage in murine tissues from both central nervous system (CNS) and peripheral nervous system (PNS). To determine whether ROS can cause structural damage to the internodal myelin, whole sciatic and optic nerves were incubated ex vivo with a hydroxyl radical-generating system consisting of copper (Cu), hydrogen peroxide (HP), and ortho-phenanthroline (OP). Quantitative assessment of unfixed tissue by X-ray diffraction revealed irreversible compaction of myelin membrane stacking in both sciatic and optic nerves. Incubation in the presence of the hydroxyl radical scavenger sodium formate prevented this damage, implicating hydroxyl radical species. Myelin membranes are particularly enriched in plasmalogens, a class of ether-linked phospholipids proposed to have antioxidant properties. Myelin in sciatic nerve from plasmalogen-deficient (Pex7 knockout) mice was significantly more vulnerable to Cu/OP/HP-mediated ROS-induced compaction than myelin from WT mice. Our results directly support the role of plasmalogens as endogenous antioxidants providing a defense that protects ROS-vulnerable myelin. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Exposure to benzene metabolites causes oxidative damage in Saccharomyces cerevisiae.

    PubMed

    Raj, Abhishek; Nachiappan, Vasanthi

    2016-06-01

    Hydroquinone (HQ) and benzoquinone (BQ) are known benzene metabolites that form reactive intermediates such as reactive oxygen species (ROS). This study attempts to understand the effect of benzene metabolites (HQ and BQ) on the antioxidant status, cell morphology, ROS levels and lipid alterations in the yeast Saccharomyces cerevisiae. There was a reduction in the growth pattern of wild-type cells exposed to HQ/BQ. Exposure of yeast cells to benzene metabolites increased the activity of the anti-oxidant enzymes catalase, superoxide dismutase and glutathione peroxidase but lead to a decrease in ascorbic acid and reduced glutathione. Increased triglyceride level and decreased phospholipid levels were observed with exposure to HQ and BQ. These results suggest that the enzymatic antioxidants were increased and are involved in the protection against macromolecular damage during oxidative stress; presumptively, these enzymes are essential for scavenging the pro-oxidant effects of benzene metabolites.

  3. Tamoxifen inhibits mitochondrial oxidative stress damage induced by copper orthophenanthroline.

    PubMed

    Buelna-Chontal, Mabel; Hernández-Esquivel, Luz; Correa, Francisco; Díaz-Ruiz, Jorge Luis; Chávez, Edmundo

    2016-12-01

    In this work, we studied the effect of tamoxifen and cyclosporin A on mitochondrial permeability transition caused by addition of the thiol-oxidizing pair Cu(2+) -orthophenanthroline. The findings indicate that tamoxifen and cyclosporin A circumvent the oxidative membrane damage manifested by matrix Ca(2+) release, mitochondrial swelling, and transmembrane electrical gradient collapse. Furthermore, it was found that tamoxifen and cyclosporin A prevent the generation of TBARs promoted by Cu(2+) -orthophenanthroline, as well as the inactivation of the mitochondrial enzyme aconitase and disruption of mDNA. Electrophoretic analysis was unable to demonstrate a cross-linking reaction between membrane proteins. Yet, it was found that Cu(2+) -orthophenanthroline induced the generation of reactive oxygen species. It is thus plausible that membrane leakiness is due to an oxidative stress injury.

  4. Oxidative stress, DNA damage and repair in carcinogenesis: have we established a connection?

    PubMed

    Georgakilas, Alexandros G

    2012-12-31

    The production of a plethora of reactive oxygen and nitrogen species in the cell and tissues as the result of endogenous or exogenous mechanisms and interaction of our cells with the environment define the so called 'oxidative load'. The final balance between the oxidatively-induced stress and the various cellular defense mechanisms draw the picture on the landscape of oxidative injury and biological consequences. In this Special Issue, I have compiled a synthesis of concise reviews by leading experts in their fields. The articles focus on the current status and advances in the various pathways leading to the production of high oxidative stress, DNA damage and its processing in human cells and tissues. Significant mechanistic insights are offered as well as connections with biological and clinical significance. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  5. Bromination of deoxycytidine by eosinophil peroxidase: A mechanism for mutagenesis by oxidative damage of nucleotide precursors

    PubMed Central

    Henderson, Jeffrey P.; Byun, Jaeman; Williams, Michelle V.; McCormick, Michael L.; Parks, William C.; Ridnour, Lisa A.; Heinecke, Jay W.

    2001-01-01

    Oxidants generated by eosinophils during chronic inflammation may lead to mutagenesis in adjacent epithelial cells. Eosinophil peroxidase, a heme enzyme released by eosinophils, generates hypobromous acid that damages tissue in inflammatory conditions. We show that human eosinophils use eosinophil peroxidase to produce 5-bromodeoxycytidine. Flow cytometric, immunohistochemical, and mass spectrometric analyses all demonstrated that 5-bromodeoxycytidine generated by eosinophil peroxidase was taken up by cultured cells and incorporated into genomic DNA as 5-bromodeoxyuridine. Although previous studies have focused on oxidation of chromosomal DNA, our observations suggest another mechanism for oxidative damage of DNA. In this scenario, peroxidase-catalyzed halogenation of nucleotide precursors yields products that subsequently can be incorporated into DNA. Because the thymine analog 5-BrUra mispairs with guanine in DNA, generation of brominated pyrimidines by eosinophils might constitute a mechanism for cytotoxicity and mutagenesis at sites of inflammation. PMID:11172002

  6. 17β-estradiol protects human skin fibroblasts and keratinocytes against oxidative damage.

    PubMed

    Bottai, G; Mancina, R; Muratori, M; Di Gennaro, P; Lotti, T

    2013-10-01

    Reactive oxygen species (ROS) cause severe damage to extracellular matrix and to molecular structure of DNA, proteins and lipids. Accumulation of these molecular changes apparently constitutes the basis of cell ageing. 17b-estradiol (E2) has a key role in skin ageing homeostasis as evidenced by the accelerated decline in skin appearance seen in the perimenopausal years. Oestrogens improve many aspects of the skin such as skin thickness, vascularization, collagen content and quality. Despite these clinical evidences, the effects of oestrogens on skin at the cellular level need further clarification. HaCaT and human fibroblasts were cultured under various conditions with E2 and H2 O2 ; then were subjected to immunofluorescence and western blot analysis. Lipoperoxidation was investigated using BODIPY. In human fibroblasts oxidative stress decreases procollagen-I synthesis, while E2 significantly increases it. Fibroblasts and HaCaT cells viability in the presence of E2 demonstrates a notably increased resistance to H2 O2 effects. Furthermore E2 is able to counteract H2 O2 -mediated lipoperoxidation and DNA oxidative damage in skin cells. In this study we highlight that the menopause-associated oestrogens decline is involved in reduced collagen production and that E2 could counteract the detrimental effects of oxidative stress on the dermal compartment during skin aging. Furthermore, our data show that physiological concentrations of oestrogens are able to interfere with ROS-mediated cell viability reduction and to protect human skin cells against oxidative damage to cellular membranes and nucleic acids structure. Our experimental data show that the presence of 17β-estradiol may protect skin cells against oxidative damage and that the dramatic lowering of oestrogen levels during menopause, could render skin more susceptible to oxidative damage. © 2012 The Authors. Journal of the European Academy of Dermatology and Venereology © 2012 European Academy of Dermatology

  7. Oxidative damage in young alcohol drinkers: A preliminary study.

    PubMed

    Rendón-Ramírez, Adela; Cortés-Couto, Miriam; Martínez-Rizo, Abril Bernardette; Muñiz-Hernández, Saé; Velázquez-Fernández, Jesús Bernardino

    2013-11-01

    Oxidative damage (OD) biomarkers have been used to evaluate metabolic stress undergone by alcoholic individuals. In alcoholic patients, these biomarkers are usually measured at late stages, i.e., when the alcoholic patients are showing clear signs of impaired hepatic function. OD biomarkers are sensitive indicators of impaired metabolic function, and might be useful in early stages of alcohol consumption to identify individuals who are at greater risk of damage in later stages of alcohol consumption. The aim of the present work was to evaluate some OD biomarkers in young people at early stages of alcohol consumption. The study was carried out in a group of young people (18-23 years old) who drank alcohol, Youngsters Exposed to Alcohol (YEA) with an average intake of 118 g of ethanol/week, and a control group (CG) of non-drinkers. Blood counts, alcohol dehydrogenase (ADH) activity, glutathione peroxidase (GSH-Px) activity, oxidative damage to DNA, and lipid peroxidation were determined in both groups. The anthropometric and blood parameters of both groups were similar and no clinical symptoms of hepatic damage were observed. Nevertheless, ADH activity, lipid peroxidation, and percentage of damaged DNA cells were higher in the YEA group than in the control group. In contrast, GSH-Px activity was lower in the YEA group than in the control group. Alteration in OD biomarkers can be found in individuals with 4-5 years of alcohol drinking history. To our knowledge, this is the first study giving evidence of OD in individuals at early stages of alcohol abuse. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Photoprotective Effect of Carpomitra costata Extract against Ultraviolet B-Induced Oxidative Damage in Human Keratinocytes.

    PubMed

    Zheng, J; Hewage, S R K Madduma; Piao, Mei Jing; Kang, Kyoung Ah; Han, X; Kang, H K; Yoo, E S; Koh, Y S; Lee, N H; Ko, C S; Lee, J C; Ko, Mi Hee; Hyuna, Jin Won

    2016-01-01

    Natural marine products show various biological properties such as antiphotoaging, antioxidant, anticancer, and anti-inflammation. This study evaluated the protective effects of the brown alga Carpomitra costata (Stackhouse) Batters (Sporochnaceae) against ultraviolet B (UVB)-provoked damage in human HaCaT keratinocytes. C. costata extract (CCE) effectively reduced superoxide anion, hydroxyl radical, and UVB-stimulated intracellular reactive oxygen species (ROS) levels. CCE also restored the expression and activity of UVB-suppressed antioxidant enzymes. Furthermore, CCE decreased UVB-triggered oxidative damage to cellular components including DNA, protein, and lipid and defended the cells against mitochondrial membrane depolarization-medicated apoptosis. The results of this study indicate that CCE can safeguard human keratinocytes against UVB-induced cellular damage via a potent antioxidant mechanism. CCE may find utility as part of a therapeutic arsenal against the damaging effects of UVB radiation on the skin.

  9. Bactericidal Antibiotics Induce Mitochondrial Dysfunction and Oxidative Damage in Mammalian Cells

    PubMed Central

    Costello, James C.; Liesa, Marc; Morones-Ramirez, J Ruben; Slomovic, Shimyn; Molina, Anthony; Shirihai, Orian S.; Collins, James J.

    2013-01-01

    Prolonged antibiotic treatment can lead to detrimental side effects in patients, including ototoxicity, nephrotoxicity, and tendinopathy, yet the mechanisms underlying the effects of antibiotics in mammalian systems remain unclear. It has been suggested that bactericidal antibiotics induce the formation of toxic reactive oxygen species (ROS) in bacteria. We show that clinically relevant doses of bactericidal antibiotics—quinolones, aminoglycosides, and β-lactams—cause mitochondrial dysfunction and ROS overproduction in mammalian cells. We demonstrate that these bactericidal antibiotic–induced effects lead to oxidative damage to DNA, proteins, and membrane lipids. Mice treated with bactericidal antibiotics exhibited elevated oxidative stress markers in the blood, oxidative tissue damage, and up-regulated expression of key genes involved in antioxidant defense mechanisms, which points to the potential physiological relevance of these antibiotic effects. The deleterious effects of bactericidal antibiotics were alleviated in cell culture and in mice by the administration of the antioxidant N-acetyl-L-cysteine or prevented by preferential use of bacteriostatic antibiotics. This work highlights the role of antibiotics in the production of oxidative tissue damage in mammalian cells and presents strategies to mitigate or prevent the resulting damage, with the goal of improving the safety of antibiotic treatment in people. PMID:23825301

  10. Bactericidal antibiotics induce mitochondrial dysfunction and oxidative damage in Mammalian cells.

    PubMed

    Kalghatgi, Sameer; Spina, Catherine S; Costello, James C; Liesa, Marc; Morones-Ramirez, J Ruben; Slomovic, Shimyn; Molina, Anthony; Shirihai, Orian S; Collins, James J

    2013-07-03

    Prolonged antibiotic treatment can lead to detrimental side effects in patients, including ototoxicity, nephrotoxicity, and tendinopathy, yet the mechanisms underlying the effects of antibiotics in mammalian systems remain unclear. It has been suggested that bactericidal antibiotics induce the formation of toxic reactive oxygen species (ROS) in bacteria. We show that clinically relevant doses of bactericidal antibiotics-quinolones, aminoglycosides, and β-lactams-cause mitochondrial dysfunction and ROS overproduction in mammalian cells. We demonstrate that these bactericidal antibiotic-induced effects lead to oxidative damage to DNA, proteins, and membrane lipids. Mice treated with bactericidal antibiotics exhibited elevated oxidative stress markers in the blood, oxidative tissue damage, and up-regulated expression of key genes involved in antioxidant defense mechanisms, which points to the potential physiological relevance of these antibiotic effects. The deleterious effects of bactericidal antibiotics were alleviated in cell culture and in mice by the administration of the antioxidant N-acetyl-l-cysteine or prevented by preferential use of bacteriostatic antibiotics. This work highlights the role of antibiotics in the production of oxidative tissue damage in mammalian cells and presents strategies to mitigate or prevent the resulting damage, with the goal of improving the safety of antibiotic treatment in people.

  11. Coal tar residues produce both DNA adducts and oxidative DNA damage in human mammary epithelial cells.

    PubMed

    Leadon, S A; Sumerel, J; Minton, T A; Tischler, A

    1995-12-01

    In the present study we compare the metabolic activation of coal tar, as measured by the production of both DNA adducts and oxidative DNA damage, with that of a single carcinogen that is a constituent of this complex mixture in human mammary epithelial cells (HMEC). We find that a significant level of DNA adducts, detected by 32P-postlabeling, are formed in HMEC following exposure to coal tar residues. This treatment also results in the generation of high levels of oxidative DNA damage, as measured by the production of one type of oxidative base modification, thymine glycols. The amounts of both DNA adducts and thymine varied considerably between the various coal tar residues and did not correlate with either the total amount of polycyclic aromatic hydrocarbons (PAH) or the amount of benzo[a]pyrene (B[a]P) present in the residue. Fractionating the residue from one of the sites by sequential extraction with organic solvents indicated that while the ability to produce both types of DNA damage was contained mostly in a hexane-soluble fraction, a benzene-soluble fraction produced high levels of reactive oxygens relative to the number of total DNA adducts. We find that the total amount of PAH or B[a]P present in the coal tars from the various sites was not a predictor of the level of total DNA damage formed.

  12. Transcription-coupled homologous recombination after oxidative damage.

    PubMed

    Wei, Leizhen; Levine, Arthur Samuel; Lan, Li

    2016-08-01

    Oxidative DNA damage induces genomic instability and may lead to mutagenesis and carcinogenesis. As severe blockades to RNA polymerase II (RNA POLII) during transcription, oxidative DNA damage and the associated DNA strand breaks have a profoundly deleterious impact on cell survival. To protect the integrity of coding regions, high fidelity DNA repair at a transcriptionally active site in non-dividing somatic cells, (i.e., terminally differentiated and quiescent/G0 cells) is necessary to maintain the sequence integrity of transcribed regions. Recent studies indicate that an RNA-templated, transcription-associated recombination mechanism is important to protect coding regions from DNA damage-induced genomic instability. Here, we describe the discovery that G1/G0 cells exhibit Cockayne syndrome (CS) B (CSB)-dependent assembly of homologous recombination (HR) factors at double strand break (DSB) sites within actively transcribed regions. This discovery is a challenge to the current dogma that HR occurs only in S/G2 cells where undamaged sister chromatids are available as donor templates. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Prolonged fasting does not increase oxidative damage or inflammation in postweaned northern elephant seal pups.

    PubMed

    Vázquez-Medina, José Pablo; Crocker, Daniel E; Forman, Henry Jay; Ortiz, Rudy M

    2010-07-15

    Elephant seals are naturally adapted to survive up to three months of absolute food and water deprivation (fasting). Prolonged food deprivation in terrestrial mammals increases reactive oxygen species (ROS) production, oxidative damage and inflammation that can be induced by an increase in the renin-angiotensin system (RAS). To test the hypothesis that prolonged fasting in elephant seals is not associated with increased oxidative stress or inflammation, blood samples and muscle biopsies were collected from early (2-3 weeks post-weaning) and late (7-8 weeks post-weaning) fasted seals. Plasma levels of oxidative damage, inflammatory markers and plasma renin activity (PRA), along with muscle levels of lipid and protein oxidation, were compared between early and late fasting periods. Protein expression of angiotensin receptor 1 (AT(1)), pro-oxidant (Nox4) and antioxidant enzymes (CuZn- and Mn-superoxide dismutases, glutathione peroxidase and catalase) was analyzed in muscle. Fasting induced a 2.5-fold increase in PRA, a 50% increase in AT(1), a twofold increase in Nox4 and a 70% increase in NADPH oxidase activity. By contrast, neither tissue nor systemic indices of oxidative damage or inflammation increased with fasting. Furthermore, muscle antioxidant enzymes increased 40-60% with fasting in parallel with an increase in muscle and red blood cell antioxidant enzyme activities. These data suggest that, despite the observed increases in RAS and Nox4, an increase in antioxidant enzymes appears to be sufficient to suppress systemic and tissue indices of oxidative damage and inflammation in seals that have fasted for a prolonged period. The present study highlights the importance of antioxidant capacity in mammals during chronic periods of stress to help avoid deleterious systemic consequences.

  14. Radiation damage of gallium arsenide production cells

    NASA Technical Reports Server (NTRS)

    Mardesich, N.; Joslin, D.; Garlick, J.; Lillington, D.; Gillanders, M.; Cavicchi, B.; Scott-Monck, J.; Kachare, R.; Anspaugh, B.

    1987-01-01

    High efficiency liquid phase epitaxy (LPE) gallium arsenide cells were irradiated with 1 Mev electrons up to fluences of 1 times 10 to the 16th power cm-2. Measurements of spectral response and dark and illuminated I-V data were made at each fluence and then, using computer codes, the experimental data was fitted to gallium arsenide cell models. In this way it was possible to determine the extent of the damage, and hence damage coefficients in both the emitter and base of the cell.

  15. A new potent natural antioxidant mixture provides global protection against oxidative skin cell damage.

    PubMed

    Jorge, A T S; Arroteia, K F; Lago, J C; de Sá-Rocha, V M; Gesztesi, J; Moreira, P L

    2011-04-01

    Oxidative stress occurs when there is an over production of free radicals and cells are not able to neutralize them by their own antioxidant mechanisms. These excess of free radicals will attack cellular macromolecules leading to cell damage, function impairment or death. Because of that, antioxidant substances have been largely used in products to offer complementary protection. In this study a new mixture of three known antioxidants (cocoa, green tea and alpha-tocopherol) was evaluated and its antioxidant protection was assessed focusing on its capacity to protect main cell macromolecules. Results have shown that it has a high antioxidant capacity by protecting lipids, DNA and proteins against oxidative damage. The antioxidant effect of the mixture on cells was also investigated and it was able to reduce oxidative stress generated by lipopolisacharide in human fibroblasts. Finally, as the mixture has proved to be highly antioxidant, its effect on cell senescence was evaluated, and it was demonstrated that fibroblasts in culture had delayed senescence when treated with these actives on a mixture. All results together provide important data about a new antioxidant mixture that uses a small amount of actives and is able to protect cell against oxidative damages in a global way.

  16. XPD localizes in mitochondria and protects the mitochondrial genome from oxidative DNA damage.

    PubMed

    Liu, Jing; Fang, Hongbo; Chi, Zhenfen; Wu, Zan; Wei, Di; Mo, Dongliang; Niu, Kaifeng; Balajee, Adayabalam S; Hei, Tom K; Nie, Linghu; Zhao, Yongliang

    2015-06-23

    Xeroderma pigmentosum group D (XPD/ERCC2) encodes an ATP-dependent helicase that plays essential roles in both transcription and nucleotide excision repair of nuclear DNA, however, whether or not XPD exerts similar functions in mitochondria remains elusive. In this study, we provide the first evidence that XPD is localized in the inner membrane of mitochondria, and cells under oxidative stress showed an enhanced recruitment of XPD into mitochondrial compartment. Furthermore, mitochondrial reactive oxygen species production and levels of oxidative stress-induced mitochondrial DNA (mtDNA) common deletion were significantly elevated, whereas capacity for oxidative damage repair of mtDNA was markedly reduced in both XPD-suppressed human osteosarcoma (U2OS) cells and XPD-deficient human fibroblasts. Immunoprecipitation-mass spectrometry analysis was used to identify interacting factor(s) with XPD and TUFM, a mitochondrial Tu translation elongation factor was detected to be physically interacted with XPD. Similar to the findings in XPD-deficient cells, mitochondrial common deletion and oxidative damage repair capacity in U2OS cells were found to be significantly altered after TUFM knock-down. Our findings clearly demonstrate that XPD plays crucial role(s) in protecting mitochondrial genome stability by facilitating an efficient repair of oxidative DNA damage in mitochondria.

  17. Early oxidative damage underlying neurodegeneration in X-adrenoleukodystrophy.

    PubMed

    Fourcade, Stéphane; López-Erauskin, Jone; Galino, Jorge; Duval, Carine; Naudi, Alba; Jove, Mariona; Kemp, Stephan; Villarroya, Francesc; Ferrer, Isidre; Pamplona, Reinald; Portero-Otin, Manuel; Pujol, Aurora

    2008-06-15

    X-linked adrenoleukodystrophy (X-ALD) is a fatal neurodegenerative disorder, characterized by progressive cerebral demyelination cerebral childhood adrenoleukodystrophy (CCALD) or spinal cord neurodegeneration (adrenomyeloneuropathy, AMN), adrenal insufficiency and accumulation of very long-chain fatty acids (VLCFA) in tissues. The disease is caused by mutations in the ABCD1 gene, which encodes a peroxisomal transporter that plays a role in the import of VLCFA or VLCFA-CoA into peroxisomes. The Abcd1 knockout mice develop a spinal cord disease that mimics AMN in adult patients, with late onset at 20 months of age. The mechanisms underlying cerebral demyelination or axonal degeneration in spinal cord are unknown. Here, we present evidence by gas chromatography/mass spectrometry that malonaldehyde-lysine, a consequence of lipoxidative damage to proteins, accumulates in the spinal cord of Abcd1 knockout mice as early as 3.5 months of age. At 12 months, Abcd1- mice accumulate additional proteins modified by oxidative damage arising from metal-catalyzed oxidation and glycoxidation/lipoxidation. While we show that VLCFA excess activates enzymatic antioxidant defenses at the protein expression levels, both in neural tissue, in ex vivo organotypic spinal cord slices from Abcd1- mice, and in human ALD fibroblasts, we also demonstrate that the loss of Abcd1 gene function hampers oxidative stress homeostasis. We find that the alpha-tocopherol analog Trolox is able to reverse oxidative lesions in vitro, thus providing therapeutic hope. These results pave the way for the identification of therapeutic targets that could reverse the deregulated response to oxidative stress in X-ALD.

  18. Oxidative Damage in the Aging Heart: an Experimental Rat Model

    PubMed Central

    Marques, Gustavo Lenci; Neto, Francisco Filipak; Ribeiro, Ciro Alberto de Oliveira; Liebel, Samuel; de Fraga, Rogério; Bueno, Ronaldo da Rocha Loures

    2015-01-01

    Introduction: Several theories have been proposed to explain the cause of ‘aging’; however, the factors that affect this complex process are still poorly understood. Of these theories, the accumulation of oxidative damage over time is among the most accepted. Particularly, the heart is one of the most affected organs by oxidative stress. The current study, therefore, aimed to investigate oxidative stress markers in myocardial tissue of rats at different ages. Methods: Seventy-two rats were distributed into 6 groups of 12 animals each and maintained for 3, 6, 9, 12, 18 and 24 months. After euthanasia, the heart was removed and the levels of non-protein thiols, lipid peroxidation, and protein carbonylation, as well as superoxide dismutase and catalase activities were determined. Results: Superoxide dismutase, catalase activity and lipid peroxidation were reduced in the older groups of animals, when compared with the younger group. However, protein carbonylation showed an increase in the 12-month group followed by a decrease in the older groups. In addition, the levels of non-protein thiols were increased in the 12-month group and not detected in the older groups. Conclusion: Our data showed that oxidative stress is not associated with aging in the heart. However, an increase in non-protein thiols may be an important factor that compensates for the decrease of superoxide dismutase and catalase activity in the oldest rats, to maintain appropriate antioxidant defenses against oxidative insults. PMID:27006709

  19. Oxidative guanine base damage regulates human telomerase activity

    PubMed Central

    Fouquerel, Elise; Lormand, Justin; Bose, Arindam; Lee, Hui-Ting; Kim, Grace S.; Li, Jianfeng; Sobol, Robert W.; Freudenthal, Bret D.; Myong, Sua; Opresko, Patricia L.

    2016-01-01

    Changes in telomere length are associated with degenerative diseases and cancer. Oxidative stress and DNA damage have been linked to both positive and negative alterations in telomere length and integrity. Here we examined how the common oxidative lesion 8-oxo-7,8-dihydro-2′-deoxyguanine (8-oxoG) regulates telomere elongation by telomerase. When present in the deoxynucleoside triphosphate pool as 8-oxodGTP, telomerase utilization of the oxidized nucleotide during telomere extension is mutagenic and terminates further elongation. Depletion of the enzyme that removes oxidized dNTPs, MTH1, increases telomere dysfunction and cell death in telomerase positive cancer cells harboring shortened telomeres. In contrast, a pre-existing 8-oxoG within the telomeric DNA sequence promotes telomerase activity by destabilizing G-quadruplex structure in the DNA. We show that the mechanism by which 8-oxoG arises in the telomere, either by insertion of oxidized nucleotides or by direct reaction with free radicals, dictates whether telomerase is inhibited or stimulated and thereby, mediates the biological outcome. PMID:27820808

  20. Oxidant-induced DNA damage of target cells.

    PubMed Central

    Schraufstätter, I; Hyslop, P A; Jackson, J H; Cochrane, C G

    1988-01-01

    In this study we examined the leukocytic oxidant species that induce oxidant damage of DNA in whole cells. H2O2 added extracellularly in micromolar concentrations (10-100 microM) induced DNA strand breaks in various target cells. The sensitivity of a specific target cell was inversely correlated to its catalase content and the rate of removal of H2O2 by the target cell. Oxidant species produced by xanthine oxidase/purine or phorbol myristate acetate-stimulated monocytes induced DNA breakage of target cells in proportion to the amount of H2O2 generated. These DNA strand breaks were prevented by extracellular catalase, but not by superoxide dismutase. Cytotoxic doses of HOCl, added to target cells, did not induce DNA strand breakage, and myeloperoxidase added extracellularly in the presence of an H2O2-generating system, prevented the formation of DNA strand breaks in proportion to its H2O2 degrading capacity. The studies also indicated that H2O2 formed hydroxyl radical (.OH) intracellularly, which appeared to be the most likely free radical responsible for DNA damage: .OH was detected in cells exposed to H2O2; the DNA base, deoxyguanosine, was hydroxylated in cells exposed to H2O2; and intracellular iron was essential for induction of DNA strand breaks. PMID:2843565

  1. SOS processing of unique oxidative DNA damages in Escherichia coli.

    PubMed

    Laspia, M F; Wallace, S S

    1989-05-05

    phi X174 replicative form (RF) I transfecting DNA containing thymine glycols (5,6-dihydroxy-5,6-dihydrothymine), urea glycosides or apurinic (AP) sites was used to study SOS processing of unique DNA damages in Escherichia coli. All three lesions can be found in DNA damaged by chemical oxidants or radiation and are representative of several common structural modifications of DNA bases. When phi X DNA containing thymine glycols was transfected into host cells that were ultraviolet-irradiated to induce the SOS response, a substantial increase in survival was observed compared to transfection into uninduced hosts. Studies with mutants demonstrated that both the activated form of RecA and UmuDC proteins were required for this reactivation. In contrast, no increase in survival was observed when DNA containing urea glycosides or AP sites was transfected into ultraviolet-induced hosts. These data suggest that SOS-induced reactivation does not reflect a generalized repair system for all replication-blocking, lethal lesions but rather that the efficiency of reactivation is damage dependent. Further, we found that a significant fraction of potentially lethal thymine glycols could be ultraviolet-reactivated in an umuC lexA recA-independent manner, suggesting the existence of an as yet uncharacterized damage-inducible SOS-independent mode of thymine glycol repair.

  2. Oxidative damage and neurodegeneration in manganese-induced neurotoxicity

    SciTech Connect

    Milatovic, Dejan; Yu, Yingchun

    2009-10-15

    Exposure to excessive manganese (Mn) levels results in neurotoxicity to the extrapyramidal system and the development of Parkinson's disease (PD)-like movement disorder, referred to as manganism. Although the mechanisms by which Mn induces neuronal damage are not well defined, its neurotoxicity appears to be regulated by a number of factors, including oxidative injury, mitochondrial dysfunction and neuroinflammation. To investigate the mechanisms underlying Mn neurotoxicity, we studied the effects of Mn on reactive oxygen species (ROS) formation, changes in high-energy phosphates (HEP), neuroinflammation mediators and associated neuronal dysfunctions both in vitro and in vivo. Primary cortical neuronal cultures showed concentration-dependent alterations in biomarkers of oxidative damage, F{sub 2}-isoprostanes (F{sub 2}-IsoPs) and mitochondrial dysfunction (ATP), as early as 2 h following Mn exposure. Treatment of neurons with 500 {mu}M Mn also resulted in time-dependent increases in the levels of the inflammatory biomarker, prostaglandin E{sub 2} (PGE{sub 2}). In vivo analyses corroborated these findings, establishing that either a single or three (100 mg/kg, s.c.) Mn injections (days 1, 4 and 7) induced significant increases in F{sub 2}-IsoPs and PGE{sub 2} in adult mouse brain 24 h following the last injection. Quantitative morphometric analyses of Golgi-impregnated striatal sections from mice exposed to single or three Mn injections revealed progressive spine degeneration and dendritic damage of medium spiny neurons (MSNs). These findings suggest that oxidative stress, mitochondrial dysfunction and neuroinflammation are underlying mechanisms in Mn-induced neurodegeneration.

  3. Manuka honey protects middle-aged rats from oxidative damage

    PubMed Central

    Jubri, Zakiah; Rahim, Noor Baitee Abdul; Aan, Goon Jo

    2013-01-01

    OBJECTIVE: This study aimed to determine the effect of manuka honey on the oxidative status of middle-aged rats. METHOD: Twenty-four male Sprague-Dawley rats were divided into young (2 months) and middle-aged (9 months) groups. They were further divided into two groups each, which were either fed with plain water (control) or supplemented with 2.5 g/kg body weight of manuka honey for 30 days. The DNA damage level was determined via the comet assay, the plasma malondialdehyde level was determined using high performance liquid chromatography, and the antioxidant enzyme activities (superoxide dismutase, glutathione peroxidase, glutathione peroxidase and catalase) were determined spectrophotometrically in the erythrocytes and liver. The antioxidant activities were measured using 1,1-diphenyl-2-picrylhydrazyl and ferric reducing/antioxidant power assays, and the total phenolic content of the manuka was analyzed using UV spectrophotometry and the Folin-Ciocalteu method, respectively. RESULTS: Supplementation with manuka honey reduced the level of DNA damage, the malondialdehyde level and the glutathione peroxidase activity in the liver of both the young and middle-aged groups. However, the glutathione peroxidase activity was increased in the erythrocytes of middle-aged rats given manuka honey supplementation. The catalase activity was reduced in the liver and erythrocytes of both young and middle-aged rats given supplementation. Manuka honey was found to have antioxidant activity and to have a high total phenolic content. These findings showed a strong correlation between the total phenolic content and antioxidant activity. CONCLUSIONS: Manuka honey reduces oxidative damage in young and middle-aged rats; this effect could be mediated through the modulation of its antioxidant enzyme activities and its high total phenolic content. Manuka honey can be used as an alternative supplement at an early age to improve the oxidative status. PMID:24270958

  4. Genetic damage caused by methyl-parathion in mouse spermatozoa is related to oxidative stress

    SciTech Connect

    Pina-Guzman, B.; Solis-Heredia, M.J.; Rojas-Garcia, A.E.; Uriostegui-Acosta, M.; Quintanilla-Vega, B. . E-mail: mquintan@cinvestav.mx

    2006-10-15

    Organophosphorous (OP) pesticides are considered genotoxic mainly to somatic cells, but results are not conclusive. Few studies have reported OP alterations on sperm chromatin and DNA, and oxidative stress has been related to their toxicity. Sperm cells are very sensitive to oxidative damage which has been associated with reproductive dysfunctions. We evaluated the effects of methyl-parathion (Me-Pa; a widely used OP) on sperm DNA, exploring the sensitive stage(s) of spermatogenesis and the relationship with oxidative stress. Male mice (10-12-weeks old) were administered Me-Pa (3-20 mg/kg bw/i.p.) and euthanized at 7- or 28-days post-treatment. Mature spermatozoa were obtained and evaluated for chromatin structure through SCSA (Sperm Chromatin Structure Assay; DNA Fragmentation Index parameters: Mean DFI and DFI%) and chromomycin-A{sub 3} (CMA{sub 3})-staining, for DNA damage through in situ-nick translation (NT-positive) and for oxidative stress through lipid peroxidation (LPO; malondialdehyde production). At 7-days post-treatment (mature spermatozoa when Me-Pa exposure), dose-dependent alterations in chromatin structure (Mean DFI and CMA{sub 3}-staining) were observed, as well as increased DNA damage, from 2-5-fold in DFI% and NT-positive cells. Chromatin alterations and DNA damage were also observed at 28-days post-treatment (cells at meiosis at the time of exposure); suggesting that the damage induced in spermatocytes was not repaired. Positive correlations were observed between LPO and sperm DNA-related parameters. These data suggest that oxidative stress is related to Me-Pa alterations on sperm DNA integrity and cells at meiosis (28-days post-treatment) and epididymal maturation (7-days post-treatment) are Me-Pa targets. These findings suggest a potential risk of Me-Pa to the offspring after transmission.

  5. Aluminum phosphide-induced genetic and oxidative damages in rats: attenuation by Laurus nobilis leaf extract.

    PubMed

    Türkez, Hasan; Toğar, Başak

    2013-08-01

    Aluminum phosphide (AlP) is a colorless, flammable, liquefied pesticide that is commonly used to control insects, nematodes, weeds, and pathogens in crops, forests, ornamental nurseries, and wood products. Early investigations of AlP-poisoned mammalian cells led to the proposed involvement of oxidative damage in its toxicity mechanism. Therefore, this study was aimed to evaluate the effect of Laurus nobilis (L) leaf extract (LNE) against AlP-induced genetic and oxidative damages in rats. Selected animals were assigned to four groups (n = 6), namely, group A: control (only distilled water is injected); group B: AlP (4 mg kg(-1) injected intraperitoneally (i.p.)); group C: LNE (200 mg kg(-1) injected i.p.), and group D: AlP plus LNE, respectively. The experimental period lasted for 14 successive days. Chromosomal aberrations (CAs) and micronucleus (MN) assay were used for monitoring genotoxic damage. In addition, biochemical parameters such as total antioxidant capacity (TAC) and total oxidative status (TOS) were examined in serum samples to determine oxidative damage. Our results indicated that AlP caused increase in CA and MN assay rates and alterations in TAC and TOS levels when compared with control group. On the contrary, LNE did not change the rates of both the analyzed cytogenetic end points and led to increase in TAC level. Moreover, we observed that LNE suppressed the genetic damage by AlP to bone marrow cells in vivo. Interestingly AlP-induced oxidative stress was also strongly reduced by LNE. The results of the present study indicated that the protective effect of LNE might be ascribable to its antioxidant and free radical scavenging properties.

  6. Sildenafil ameliorates oxidative stress and DNA damage in the stenotic kidneys in mice with renovascular hypertension

    PubMed Central

    2014-01-01

    Background Oxidative stress and DNA damage have been implicated in the pathogenesis of renovascular hypertension induced by renal artery stenosis in the two-kidney, one-clip (2K1C) Goldblatt model. Considering our previous report indicating that the chronic blockade of phosphodiesterase 5 with sildenafil (Viagra®) has marked beneficial effects on oxidative stress and DNA damage, we tested the hypothesis that sildenafil could also protect the stenotic kidneys of 2K1C hypertensive mice against oxidative stress and genotoxicity. Methods The experiments were performed with C57BL6 mice subjected to renovascular hypertension by left renal artery clipping. Two weeks after clipping, the mice were treated with sildenafil (40 mg/kg/day for 2 weeks, 2K1C-sildenafil group) or the vehicle (2K1C). These mice were compared with control mice not subjected to renal artery clipping (Sham). After hemodynamic measurements, the stenotic kidneys were assessed using flow cytometry to evaluate cell viability and the comet assay to evaluate DNA damage. Measurements of intracellular superoxide anions and hydrogen peroxide levels as well as nitric oxide bioavailability were also obtained. Results Sildenafil treatment significantly reduced mean arterial pressure (15%), heart rate (8%), intrarenal angiotensin II (50%) and renal atrophy (36%). In addition, it caused a remarkable decrease of reactive oxygen species production. On the other hand, sildenafil increased nitric oxide levels relative to those in the nontreated 2K1C mice. Sildenafil treatment also significantly reduced the high level of kidney DNA damage that is a characteristic of renovascular hypertensive mice. Conclusions Our data reveal that sildenafil has a protective effect on the stenotic kidneys of 2K1C mice, suggesting a new use of phosphodiesterase 5 inhibitors for protection against the DNA damage observed in the hypoperfused kidneys of individuals with renovascular hypertension. Further translational research is

  7. SIRT3 mediates decrease of oxidative damage and prevention of ageing in porcine fetal fibroblasts.

    PubMed

    Xie, Xiaoxian; Wang, Liangliang; Zhao, Binggong; Chen, Yangyang; Li, Jiaqi

    2017-05-15

    Sirtuin 3 (SIRT3) is a mitochondria-specific protein required for the deacetylation of metabolic enzymes and the action of oxidative phosphorylation by acting as a nicotinamide adenine dinucleotide (NAD(+))-dependent deacetylase. SIRT3 increases oxidative stress resistance and prevents mitochondrial decay associated with ageing in response to caloric restriction. However, the effects of SIRT3 on oxidative damage and ageing are not well understood. We investigated the physiological functions of porcine SIRT3 on the damage and ageing in porcine fetal fibroblasts (PFFs). Overexpression and knockdown of SIRT3 were confirmed by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot analysis, respectively. All cells were treated with three different stress reagents 12-o-tetradecanoylphorbol-13-acetate (TPA), methanesulfonic acid methylester (MMS), and tert-butylhydroperoxide (t-BHP), respectively, and then examined by flow cytometry following JC-1 (5, 5', 6, 6'-tetrachloro-1, 1', 3, 3'-tetraethylbenzimidazol-carbocyanine iodide) staining. SIRT3 overexpression enhanced the ability of superoxide dismutase 2 (SOD2) to reduce cellular reactive oxygen species (ROS), which further decreased the damage to the membranes and the organelles of the cells, especially to mitochondria. It inhibited the initial decrease of mitochondrial membrane potential, and prevented the decrease of adenosine triphosphate (ATP) production and activity of Nampt. In contrast, SIRT3 knockdown reduced the ability of SOD2 to increase cellular ROS which was directly correlated with stress-induced oxidative damage and ageing in PFFs. Our findings identify one function of SIRT3 in PFFs was to dampen cytotoxicity, and, therefore, to decrease oxidative damage and attenuate ageing possibly by enhancing the activity of SOD2. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Textile industrial effluent induces mutagenicity and oxidative DNA damage and exploits oxidative stress biomarkers in rats.

    PubMed

    Akhtar, Muhammad Furqan; Ashraf, Muhammad; Anjum, Aftab Ahmad; Javeed, Aqeel; Sharif, Ali; Saleem, Ammara; Akhtar, Bushra

    2016-01-01

    Exposure to complex mixtures like textile effluent poses risks to animal and human health such as mutations, genotoxicity and oxidative damage. Aim of the present study was to quantify metals in industrial effluent and to determine its mutagenic, genotoxic and cytotoxic potential and effects on oxidative stress biomarkers in effluent exposed rats. Metal analysis revealed presence of high amounts of zinc, copper, chromium, iron, arsenic and mercury in industrial effluent. Ames test with/without enzyme activation and MTT assay showed strong association of industrial effluent with mutagenicity and cytotoxicity respectively. In-vitro comet assay revealed evidence of high oxidative DNA damage. When Wistar rats were exposed to industrial effluent in different dilutions for 60 days, then activities of total superoxide dismutase and catalase and hydrogen peroxide concentration were found to be significantly lower in kidney, liver and blood/plasma of effluent exposed rats than control. Vitamin C in a dose of 50 mg/kg/day significantly reduced oxidative effects of effluent in rats. On the basis of this study it is concluded that industrial effluent may cause mutagenicity, in-vitro oxidative stress-related DNA damage and cytotoxicity and may be associated with oxidative stress in rats. Vitamin C may have ameliorating effect when exposed to effluent. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Displacement Cascade Damage Production in Metals

    SciTech Connect

    Stoller, Roger E; Malerba, Lorenzo; Nordlund, Kai

    2015-01-01

    Radiation-induced changes in microstructure and mechanical properties in structural materials are the result of a complex set of physical processes initiated by the collision between an energetic particle (neutron or ion) and an atom in the lattice. This primary damage event is called an atomic displacement cascade. The simplest description of a displacement cascade is to view it as a series of many billiard-ball-like elastic collisions among the atoms in the material. This chapter describes the formation and evolution of this primary radiation damage mechanism to provide an overview of how stable defects are formed by displacement cascades, as well as the nature and morphology of the defects themselves. The impact of the relevant variables such as cascade energy and irradiation temperature is discussed, and defect formation in different materials is compared.

  10. Highly oxidized graphene oxide and methods for production thereof

    DOEpatents

    Tour, James M.; Kosynkin, Dmitry V.

    2016-08-30

    A highly oxidized form of graphene oxide and methods for production thereof are described in various embodiments of the present disclosure. In general, the methods include mixing a graphite source with a solution containing at least one oxidant and at least one protecting agent and then oxidizing the graphite source with the at least one oxidant in the presence of the at least one protecting agent to form the graphene oxide. Graphene oxide synthesized by the presently described methods is of a high structural quality that is more oxidized and maintains a higher proportion of aromatic rings and aromatic domains than does graphene oxide prepared in the absence of at least one protecting agent. Methods for reduction of graphene oxide into chemically converted graphene are also disclosed herein. The chemically converted graphene of the present disclosure is significantly more electrically conductive than is chemically converted graphene prepared from other sources of graphene oxide.

  11. Role of Oxidative Damage in Radiation-Induced Bone Loss

    NASA Technical Reports Server (NTRS)

    Schreurs, Ann-Sofie; Alwood, Joshua S.; Limoli, Charles L.; Globus, Ruth K.

    2014-01-01

    During prolonged spaceflight, astronauts are exposed to both microgravity and space radiation, and are at risk for increased skeletal fragility due to bone loss. Evidence from rodent experiments demonstrates that both microgravity and ionizing radiation can cause bone loss due to increased bone-resorbing osteoclasts and decreased bone-forming osteoblasts, although the underlying molecular mechanisms for these changes are not fully understood. We hypothesized that excess reactive oxidative species (ROS), produced by conditions that simulate spaceflight, alter the tight balance between osteoclast and osteoblast activities, leading to accelerated skeletal remodeling and culminating in bone loss. To test this, we used the MCAT mouse model; these transgenic mice over-express the human catalase gene targeted to mitochondria, the major organelle contributing free radicals. Catalase is an anti-oxidant that converts reactive species, hydrogen peroxide into water and oxygen. This animal model was selected as it displays extended lifespan, reduced cardiovascular disease and reduced central nervous system radio-sensitivity, consistent with elevated anti-oxidant activity conferred by the transgene. We reasoned that mice overexpressing catalase in mitochondria of osteoblast and osteoclast lineage cells would be protected from the bone loss caused by simulated spaceflight. Over-expression of human catalase localized to mitochondria caused various skeletal phenotypic changes compared to WT mice; this includes greater bone length, decreased cortical bone area and moment of inertia, and indications of altered microarchitecture. These findings indicate mitochondrial ROS are important for normal bone-remodeling and skeletal integrity. Catalase over-expression did not fully protect skeletal tissue from structural decrements caused by simulated spaceflight; however there was significant protection in terms of cellular oxidative damage (MDA levels) to the skeletal tissue. Furthermore, we

  12. Influence of dietary carbohydrate on zinc-deficiency-induced changes in oxidative defense mechanisms and tissue oxidative damage in rats.

    PubMed

    Kim, S H; Keen, C L

    1999-10-01

    The aim of this study was to determine the effect of dietary carbohydrate type on the expression of zinc (Zn) deficiency in rats with respect to tissue oxidative damage and defense mechanisms. Rats were fed diets containing adequate (+Zn) or low concentrations (-Zn) of Zn. Both fructose- and glucose-based diets were tested. Pair-fed controls were also studied to evaluate changes in the oxidative defense system which are secondary to Zn-deficiency-induced anorexia. Plasma and liver Zn concentrations and CuZn superoxide dismutase activities were lower in the -Zn rats than in the +Zn rats. Liver glutathione (GSH) and disulfide glutathione concentrations were higher in the -Zn rats than in the +Zn rats; this difference was most pronounced in the fructose groups. Liver and heart selenium glutathione peroxidase (Se-GSH-Px) activities were lower in the -Zn-fructose group than in the +Zn-fructose group. Liver Se-GSH-Px activity was higher in the fructose groups than in the glucose groups. Liver GSH reductase (GSH-Red) activity was lower in the -Zn-fructose group than in its control group. Liver glutamine synthetase activity was lower in the -Zn-glucose group and in the fructose groups than in the glucose control group. Liver thiobarbituric acid reactive substance (TBARS) production was similar among the groups. Collectively, these results support the concept that Zn deficiency can result in an impaired oxidant defense system. Based on the observation that pair-fed control animals also showed evidence of oxidative damage, we suggest that one factor that contributes to the effect of Zn deficiency is the reduction in caloric intake that occurs in these animals. Fructose feeding resulted in increased activities of several of the oxidant defense enzymes. Protein oxidative damage assessed by glutamine synthetase activity was increased by both Zn deficiency and fructose feeding.

  13. Oxidative DNA damage background estimated by a system model of base excision repair

    SciTech Connect

    Sokhansanj, B A; Wilson, III, D M

    2004-05-13

    Human DNA can be damaged by natural metabolism through free radical production. It has been suggested that the equilibrium between innate damage and cellular DNA repair results in an oxidative DNA damage background that potentially contributes to disease and aging. Efforts to quantitatively characterize the human oxidative DNA damage background level based on measuring 8-oxoguanine lesions as a biomarker have led to estimates varying over 3-4 orders of magnitude, depending on the method of measurement. We applied a previously developed and validated quantitative pathway model of human DNA base excision repair, integrating experimentally determined endogenous damage rates and model parameters from multiple sources. Our estimates of at most 100 8-oxoguanine lesions per cell are consistent with the low end of data from biochemical and cell biology experiments, a result robust to model limitations and parameter variation. Our results show the power of quantitative system modeling to interpret composite experimental data and make biologically and physiologically relevant predictions for complex human DNA repair pathway mechanisms and capacity.

  14. Oxidative DNA damage background estimated by a system model of base excision repair.

    PubMed

    Sokhansanj, Bahrad A; Wilson, David M

    2004-08-01

    Human DNA can be damaged by natural metabolism through free radical production. It has been suggested that the equilibrium between innate damage and cellular DNA repair results in an oxidative DNA damage background that potentially contributes to disease and aging. Efforts to quantitatively characterize the human oxidative DNA damage background level, based on measuring 8-oxoguanine lesions as a biomarker, have led to estimates that vary over three to four orders of magnitude, depending on the method of measurement. We applied a previously developed and validated quantitative pathway model of human DNA base excision repair, integrating experimentally determined endogenous damage rates and model parameters from multiple sources. Our estimates of at most 100 8-oxoguanine lesions per cell are consistent with the low end of data from biochemical and cell biology experiments, a result robust to model limitations and parameter variation. Our findings show the power of quantitative system modeling to interpret composite experimental data and make biologically and physiologically relevant predictions for complex human DNA repair pathway mechanisms and capacity.

  15. Hydroxytyrosol protects against oxidative DNA damage in human breast cells.

    PubMed

    Warleta, Fernando; Quesada, Cristina Sánchez; Campos, María; Allouche, Yosra; Beltrán, Gabriel; Gaforio, José J

    2011-10-01

    Over recent years, several studies have related olive oil ingestion to a low incidence of several diseases, including breast cancer. Hydroxytyrosol and tyrosol are two of the major phenols present in virgin olive oils. Despite the fact that they have been linked to cancer prevention, there is no evidence that clarifies their effect in human breast tumor and non-tumor cells. In the present work, we present hydroxytyrosol and tyrosol's effects in human breast cell lines. Our results show that hydroxytyrosol acts as a more efficient free radical scavenger than tyrosol, but both fail to affect cell proliferation rates, cell cycle profile or cell apoptosis in human mammary epithelial cells (MCF10A) or breast cancer cells (MDA-MB-231 and MCF7). We found that hydroxytyrosol decreases the intracellular reactive oxygen species (ROS) level in MCF10A cells but not in MCF7 or MDA-MB-231 cells while very high amounts of tyrosol is needed to decrease the ROS level in MCF10A cells. Interestingly, hydroxytyrosol prevents oxidative DNA damage in the three breast cell lines. Therefore, our data suggest that simple phenol hydroxytyrosol could contribute to a lower incidence of breast cancer in populations that consume virgin olive oil due to its antioxidant activity and its protection against oxidative DNA damage in mammary cells.

  16. Hydroxytyrosol Protects against Oxidative DNA Damage in Human Breast Cells

    PubMed Central

    Warleta, Fernando; Quesada, Cristina Sánchez; Campos, María; Allouche, Yosra; Beltrán, Gabriel; Gaforio, José J.

    2011-01-01

    Over recent years, several studies have related olive oil ingestion to a low incidence of several diseases, including breast cancer. Hydroxytyrosol and tyrosol are two of the major phenols present in virgin olive oils. Despite the fact that they have been linked to cancer prevention, there is no evidence that clarifies their effect in human breast tumor and non-tumor cells. In the present work, we present hydroxytyrosol and tyrosol’s effects in human breast cell lines. Our results show that hydroxytyrosol acts as a more efficient free radical scavenger than tyrosol, but both fail to affect cell proliferation rates, cell cycle profile or cell apoptosis in human mammary epithelial cells (MCF10A) or breast cancer cells (MDA-MB-231 and MCF7). We found that hydroxytyrosol decreases the intracellular reactive oxygen species (ROS) level in MCF10A cells but not in MCF7 or MDA-MB-231 cells while very high amounts of tyrosol is needed to decrease the ROS level in MCF10A cells. Interestingly, hydroxytyrosol prevents oxidative DNA damage in the three breast cell lines. Therefore, our data suggest that simple phenol hydroxytyrosol could contribute to a lower incidence of breast cancer in populations that consume virgin olive oil due to its antioxidant activity and its protection against oxidative DNA damage in mammary cells. PMID:22254082

  17. Direct contribution of obesity to oxidative damage to macromolecules.

    PubMed

    Karbownik-Lewinska, Małgorzata; Szosland, Janusz; Kokoszko-Bilska, Agnieszka; Stępniak, Jan; Zasada, Krzysztof; Gesing, Adam; Lewinski, Andrzej

    2012-01-01

    Obesity constitutes a common modifiable risk factor for certain non-communicable diseases (NCDs) associated with enhanced oxidative stress. The aim of the study was to examine serum concentrations of malondialdehyde + 4-hydroxyalkenals (MDA+4-HDA), as an index of lipid peroxidation (LPO), and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) concentration in peripheral blood lymphocytes, as an index of nuclear DNA damage, in overweight and obese adult patients. LPO and 8-oxodG, as well as clinical and laboratory parameters, which are frequently affected by obesity, were evaluated in 58 overweight and obese adult patients, and in 20 healthy volunteers. Both LPO and 8-oxodG levels were increased in overweight and obese patients, with further increase observed with the increasing body mass index (BMI). LPO correlated positively with body mass, BMI, waist circumference, hip circumference, waist:hip ratio, systolic or diastolic blood pressure, glucose, C-reactive protein and ferritin concentrations. 8-oxodG correlated positively with body mass, BMI, hip circumference and triglyceride concentration, whereas it correlated negatively with iron concentration. Expectedly, positive correlation between LPO and 8-oxodG was also found. BMI constituted the only independent determinant (predictor) of LPO in overweight and obese patients. Consistently, LPO did constitute the only independent determinant of obesity. Overweight and obesity in adults are directly associated with increased oxidative damage to macromolecules.

  18. Different mechanisms between copper and iron in catecholamines-mediated oxidative DNA damage and disruption of gene expression in vitro.

    PubMed

    Nishino, Yoshihiko; Ando, Motozumi; Makino, Rena; Ueda, Koji; Okamoto, Yoshinori; Kojima, Nakao

    2011-07-01

    Catechols produce reactive oxygen species (ROS) and induce oxidative DNA damage through reduction-oxidation reactions with metals such as copper. Here, we examined oxidative DNA damage by neurotransmitter catecholamines in the presence of copper or iron and evaluated the effects of this damage on gene expression in vitro. Dopamine induced strand breaks and base oxidation in calf thymus DNA in the presence of Cu(II) or Fe(III)-NTA (nitrilotriacetic acid). The extent of this damage was greater for Cu(II) than for Fe(III)-NTA. For the DNA damage induced by dopamine, the responsible reactive species were hydrogen peroxide and Cu(I) for Cu(II) and hydroxyl radicals and Fe(II) for Fe(III)-NTA. Cu(II) induced DNA conformational changes, but Fe(III)-NTA did not in the presence of dopamine. These differences indicate different modes of action between Cu and Fe-NTA with regard to the induction of DNA damage. Expression of the lacZ gene coded on plasmid DNA was inhibited depending on the extent of the oxidative damage and strand breaks. Endogenous catecholamines (dopamine, adrenaline, and noradrenaline) were more potent than catechols (no aminoalkyl side chains) or 3,4-dihydroxybenzylamine (aminomethyl side chain). These results suggest that the metal-mediated DNA damage induced by dopamine disrupts gene expression, and leukoaminochromes (further oxidation products of O-quinones having aminoethyl side chain) are involved in the DNA damage. These findings indicate a possibility that metal (especially iron and copper)-mediated oxidation of catecholamines plays an important role in the pathogenesis of neurodegenerative disorders including Parkinson's disease.

  19. Resveratrol for prenatal-stress-induced oxidative damage in growing brain and its consequences on survival of neurons.

    PubMed

    Madhyastha, Sampath; Sahu, Sudhanshu Sekhar; Rao, Gayathri

    2014-02-01

    Prenatal-stress-induced neuronal damage in offspring is multifactorial, including oxidative damage in the developing brain. Resveratrol is known to exert its neuroprotective potentials by upregulating several antioxidant systems. Hence, the study was undertaken to evaluate the neuroprotective effect of resveratrol against prenatal-stress-induced hippocampal damage and oxidative damage in neonate rat brains. Pregnant rats were subjected to restraint stress during early or late gestational period. Another set of rats received resveratrol during the entire gestational period along with early or late gestational stress. The study parameters included several antioxidant studies directly from rat brain homogenate on the 40th postnatal day and hippocampal neuronal assay on the 21st postnatal day. Early as well as late gestational stress resulted in a significant increase in lipid peroxidation and advanced oxidation protein products and decrease in total antioxidant activity and nitric oxide levels in rat brain homogenate. The neurons of the dentate gyrus were severely affected in early and late gestational stress, and only the neurons of the CA3 region were adversely affected in late gestational stress. Administration of resveratrol reversed the prenatal-stress-induced oxidative damage and neurons of dentate gyrus but not the CA3 hippocampal neurons. These results show the neuroprotective abilities of resveratrol against prenatal-stress-induced oxidative damage in neonatal rat brain.

  20. Screening SIRT1 Activators from Medicinal Plants as Bioactive Compounds against Oxidative Damage in Mitochondrial Function

    PubMed Central

    Wang, Yi; Liang, Xinying; Chen, Yaqi; Zhao, Xiaoping

    2016-01-01

    Sirtuin type 1 (SIRT1) belongs to the family of NAD+ dependent histone deacetylases and plays a critical role in cellular metabolism and response to oxidative stress. Traditional Chinese medicines (TCMs), as an important part of natural products, have been reported to exert protective effect against oxidative stress in mitochondria. In this study, we screened SIRT1 activators from TCMs and investigated their activities against mitochondrial damage. 19 activators were found in total by in vitro SIRT1 activity assay. Among those active compounds, four compounds, ginsenoside Rb2, ginsenoside F1, ginsenoside Rc, and schisandrin A, were further studied to validate the SIRT1-activation effects by liquid chromatography-mass spectrometry and confirm their activities against oxidative damage in H9c2 cardiomyocytes exposed to tert-butyl hydroperoxide (t-BHP). The results showed that those compounds enhanced the deacetylated activity of SIRT1, increased ATP content, and inhibited intracellular ROS formation as well as regulating the activity of Mn-SOD. These SIRT1 activators also showed moderate protective effects on mitochondrial function in t-BHP cells by recovering oxygen consumption and increasing mitochondrial DNA content. Our results suggested that those compounds from TCMs attenuated oxidative stress-induced mitochondrial damage in cardiomyocytes through activation of SIRT1. PMID:26981165

  1. Active paraplegics are protected against exercise-induced oxidative damage through the induction of antioxidant enzymes.

    PubMed

    Inglés, M; Serra-Añó, P; Gambini, J; Abu-Sharif, F; Dromant, M; Garcia-Valles, R; Pareja-Galeano, H; Garcia-Lucerga, C; Gomez-Cabrera, M C

    2016-10-01

    Experimental study. Exercise improves functional capacity in spinal cord injury (SCI). However, exhaustive exercise, especially when sporadic, is linked to the production of reactive oxygen species that may have a detrimental effect on SCI. We aimed to study the effect of a single bout of exhaustive exercise on systemic oxidative stress parameters and on the expression of antioxidant enzymes in individuals with paraplegia. The study was conducted in the Physical Therapy department and the Physical Education and Sports department of the University of Valencia. Sixteen paraplegic subjects were submitted to a graded exercise test (GET) until volitional exhaustion. They were divided into active or non-active groups. Blood samples were drawn immediately, 1 and 2 h after the GET. We determined plasma malondialdehyde (MDA) and protein carbonylation as markers of oxidative damage. Antioxidant gene expression (catalase and glutathione peroxidase-GPx) was determined in peripheral blood mononuclear cells. We found a significant increase in plasma MDA and protein carbonyls immediately after the GET (P<0.05). This increment correlated significantly with the lactate levels. Active paraplegics showed lower levels of exercise-induced oxidative damage (P<0.05) and higher exercise-induced catalase (P<0.01) and GPx (P<0.05) gene expression after the GET. These results suggest that exercise training may be useful in SCI patients to develop systemic antioxidant defenses that may protect them against exercise-induced oxidative damage.

  2. Reproductive Benefit of Oxidative Damage: An Oxidative Stress “Malevolence”?

    PubMed Central

    Poljsak, B.; Milisav, I.; Lampe, T.; Ostan, I.

    2011-01-01

    High levels of reactive oxygen species (ROS) compared to antioxidant defenses are considered to play a major role in diverse chronic age-related diseases and aging. Here we present an attempt to synthesize information about proximate oxidative processes in aging (relevant to free radical or oxidative damage hypotheses of aging) with an evolutionary scenario (credited here to Dawkins hypotheses) involving tradeoffs between the costs and benefits of oxidative stress to reproducing organisms. Oxidative stress may be considered a biological imperfection; therefore, the Dawkins' theory of imperfect adaptation of beings to environment was applied to the role of oxidative stress in processes like famine and infectious diseases and their consequences at the molecular level such as mutations and cell signaling. Arguments are presented that oxidative damage is not necessarily an evolutionary mistake but may be beneficial for reproduction; this may prevail over its harmfulness to health and longevity in evolution. Thus, Dawkins' principle of biological “malevolence” may be an additional biological paradigm for explaining the consequences of oxidative stress. PMID:21969876

  3. Oxidative DNA damage induced by benz[a]anthracene dihydrodiols in the presence of dihydrodiol dehydrogenase.

    PubMed

    Seike, Kazuharu; Murata, Mariko; Hirakawa, Kazutaka; Deyashiki, Yoshihiro; Kawanishi, Shosuke

    2004-11-01

    Tobacco smoke and polluted air are risk factors for lung cancer and contain many kinds of polycyclic aromatic hydrocarbons (PAHs) including benzo[a]pyrene (B[a]P) and benz[a]anthracene (BA). BA, as well as B[a]P, is assessed as probably carcinogenic to humans (IARC group 2A). BA is metabolized to several dihydrodiols. Dihydrodiol dehydrogenase (DD), a member of the aldo-keto reductase superfamily, catalyzes NAD(P)+-linked oxidation of dihydrodiols of aromatic hydrocarbons to corresponding catechols. To clarify the role of DD on PAH carcinogenesis, we examined oxidative DNA damage induced by trans-dihydrodiols of BA and B[a]P treated with DD using 32P-5'-end-labeled DNA fragments obtained from the human p53 tumor suppressor gene. In addition, we investigated the formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), an indicator of oxidative DNA damage, in calf thymus DNA by using HPLC with an electrochemical detector. DD-catalyzed BA-1,2-dihydrodiol caused Cu(II)-mediated DNA damage including 8-oxodG formation in the presence of NAD+. BA-1,2-dihydrodiol induced a Fpg sensitive and piperidine labile G lesion at the 5'-ACG-3' sequence complementary to codon 273 of the human p53 tumor suppressor gene, which is known as a hotspot. DNA damage was inhibited by catalase and bathocuproine, suggesting the involvement of H2O2 and Cu(I). The observation of NADH production by UV-visible spectroscopy suggested that DD catalyzed BA-1,2-dihydrodiol most efficiently to the corresponding catechol among the PAH-dihydrodiols tested. A time-of-flight mass spectroscopic study showed that the catechol form of BA-1,2-dihydrodiol formed after DD treatment. In conclusion, BA-1,2-dihydrodiol can induce DNA damage more efficiently than B[a]P-7,8-dihydrodiol and other BA-dihydrodiols in the presence of DD. The reaction mechanism on oxidative DNA damage may be explained by theoretical calculations with an enthalpy change of dihydrodiols and oxidation potential of their catechol forms. DD

  4. Oxidative damage of naphthenic acids on the Eisenia fetida earthworm.

    PubMed

    Wang, Jie; Cao, Xiaofeng; Chai, Liwei; Liao, Jingqiu; Huang, Yi; Tang, Xiaoyan

    2016-11-01

    Naphthenic acids (NAs) have been gaining recognition in recent years as potentially harmful environmental contaminants. Few studies have focused on the potential ecotoxicity of NAs to terrestrial environment. In this study, the responses of antioxidant system and lipid peroxidation and DNA damage were investigated after exposing Eisenia fetida to soil contaminated with NAs. The results indicated that NAs induced a significant increase (p < 0.05) in superoxide dismutase and catalase enzyme activities. The glutathione peroxidase enzyme activities were significantly inhibited (p < 0.05) in the medium and high dose treatments. An increase in malondialidehyde indicated that NAs could cause cellular lipid peroxidation in the tested earthworms. The percentage of DNA in the tail of comet assay of coelomocytes as an indication of DNA damage increased after treatment with different doses of NAs, and a dose-dependent DNA damage of coelomocytes was found. In conclusion, oxidative stress caused by NAs exposure induces physiological responses and genotoxicity on earthworms. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1337-1343, 2016. © 2015 Wiley Periodicals, Inc.

  5. DNA photo-oxidative damage hazard in transfection complexes.

    PubMed

    Rudiuk, Sergii; Franceschi-Messant, Sophie; Chouini-Lalanne, Nadia; Perez, Emile; Rico-Lattes, Isabelle

    2011-01-01

    Complexes of DNA with various cationic vectors have been largely used for nonviral transfection, and yet the photochemical stability of DNA in such complexes has never been considered. We studied, for the first time, the influence of DNA complexation by a cationic lipid and polymers on the amount of damage induced by benzophenone photosensitization. The localization of benzophenone inside the hydrophobic domains formed by a cationic lipid, DOTAP (N-[1-(2,3-dioleoyloxy)propyl]-N,N,N-trimethylammonium chloride), and close to DNA, locally increases the photoinduced cleavage by the reactive oxygen species generated. The same effect was found in the case of DNA complexation with an amphiphilic polymer (polynorbornenemethyleneammonium chloride). However, a decrease in DNA damage was observed in the case of complexation with a hydrophilic polymer (polyethylenimine). The DNA protection in this case was because of the absence of benzophenone hydrophobic incorporation into the complex, and to DNA compaction which decreased the probability of radical attack. These results underline the importance of the chemical structure of the nonviral transfection vector in limiting the risks of photo-oxidative damage of the complexed DNA. © 2010 The Authors. Photochemistry and Photobiology © 2010 The American Society of Photobiology.

  6. Cerium Oxide Nanoparticles in Lung Acutely Induce Oxidative Stress, Inflammation, and DNA Damage in Various Organs of Mice.

    PubMed

    Nemmar, Abderrahim; Yuvaraju, Priya; Beegam, Sumaya; Fahim, Mohamed A; Ali, Badreldin H

    2017-01-01

    CeO2 nanoparticles (CeO2 NPs) which are used as a diesel fuel additive are emitted in the particulate phase in the exhaust, posing a health concern. However, limited information exists regarding the in vivo acute toxicity of CeO2 NPs on multiple organs. Presently, we investigated the acute (24 h) effects of intratracheally instilled CeO2 NPs in mice (0.5 mg/kg) on oxidative stress, inflammation, and DNA damage in major organs including lung, heart, liver, kidneys, spleen, and brain. Lipid peroxidation measured by malondialdehyde production was increased in the lungs only, and reactive oxygen species were increased in the lung, heart, kidney, and brain. Superoxide dismutase activity was decreased in the lung, liver, and kidney, whereas glutathione increased in lung but it decreased in the kidney. Total nitric oxide was increased in the lung and spleen but it decreased in the heart. Tumour necrosis factor-α increased in all organs studied. Interleukin- (IL-) 6 increased in the lung, heart, liver, kidney, and spleen. IL-1β augmented in the lung, heart, kidney, and spleen. Moreover, CeO2 NPs induced DNA damage, assessed by COMET assay, in all organs studied. Collectively, these findings indicate that pulmonary exposure to CeO2 NPs causes oxidative stress, inflammation, and DNA damage in multiple organs.

  7. Cerium Oxide Nanoparticles in Lung Acutely Induce Oxidative Stress, Inflammation, and DNA Damage in Various Organs of Mice

    PubMed Central

    Yuvaraju, Priya; Beegam, Sumaya; Fahim, Mohamed A.; Ali, Badreldin H.

    2017-01-01

    CeO2 nanoparticles (CeO2 NPs) which are used as a diesel fuel additive are emitted in the particulate phase in the exhaust, posing a health concern. However, limited information exists regarding the in vivo acute toxicity of CeO2 NPs on multiple organs. Presently, we investigated the acute (24 h) effects of intratracheally instilled CeO2 NPs in mice (0.5 mg/kg) on oxidative stress, inflammation, and DNA damage in major organs including lung, heart, liver, kidneys, spleen, and brain. Lipid peroxidation measured by malondialdehyde production was increased in the lungs only, and reactive oxygen species were increased in the lung, heart, kidney, and brain. Superoxide dismutase activity was decreased in the lung, liver, and kidney, whereas glutathione increased in lung but it decreased in the kidney. Total nitric oxide was increased in the lung and spleen but it decreased in the heart. Tumour necrosis factor-α increased in all organs studied. Interleukin- (IL-) 6 increased in the lung, heart, liver, kidney, and spleen. IL-1β augmented in the lung, heart, kidney, and spleen. Moreover, CeO2 NPs induced DNA damage, assessed by COMET assay, in all organs studied. Collectively, these findings indicate that pulmonary exposure to CeO2 NPs causes oxidative stress, inflammation, and DNA damage in multiple organs. PMID:28392888

  8. Fisetin Protects DNA Against Oxidative Damage and Its Possible Mechanism

    PubMed Central

    Wang, Tingting; Lin, Huajuan; Tu, Qian; Liu, Jingjing; Li, Xican

    2016-01-01

    Purpose: The paper tries to assess the protective effect of fisetin against •OH-induced DNA damage, then to investigate the possible mechanism. Methods: The protective effect was evaluated based on the content of malondialdehyde (MDA). The possible mechanism was analyzed using various antioxidant methods in vitro, including •OH scavenging (deoxyribose degradation), •O2- scavenging (pyrogallol autoxidation), DPPH• scavenging, ABTS•+ scavenging, and Cu2+-reducing power assays. Results: Fisetin increased dose-dependently its protective percentages against •OH-induced DNA damage (IC50 value =1535.00±29.60 µM). It also increased its radical-scavenging percentages in a dose-dependent manner in various antioxidants assays. Its IC50 values in •OH scavenging, •O2- scavenging, DPPH• scavenging, ABTS•+ scavenging, and Cu2+-reducing power assays, were 47.41±4.50 µM, 34.05±0.87 µM, 9.69±0.53 µM, 2.43±0.14 µM, and 1.49±0.16 µM, respectively. Conclusion: Fisetin can effectively protect DNA against •OH-induced oxidative damage possibly via reactive oxygen species (ROS) scavenging approach, which is assumed to be hydrogen atom (H•) and/or single electron (e) donation (HAT/SET) pathways. In the HAT pathway, the 3’,4’-dihydroxyl moiety in B ring of fisetin is thought to play an important role, because it can be ultimately oxidized to a stable ortho-benzoquinone form. PMID:27478791

  9. Oxidative damage involves in the inhibitory effect of nitric oxide on spore germination of Penicillium expansum.

    PubMed

    Lai, Tongfei; Li, Boqiang; Qin, Guozheng; Tian, Shiping

    2011-01-01

    The effects of nitric oxide (NO) on spore germination of Penicillium expansum were investigated and a possible mechanism was evaluated. The results indicated that NO released by sodium nitroprusside (SNP) significantly suppressed fungal growth. With the use of an oxidant sensitive probe and Western blot analysis, an increased level of intracellular reactive oxygen species (ROS) and enhanced carbonylation damage were detected in spores of P. expansum under NO stress. Exogenous superoxide dismutase (SOD) and ascorbic acid (Vc) could increase the resistance of the spore to the inhibitory effect of NO. The activities of SOD and catalase (CAT), as well as ATP content in spores under NO stress were also lower than those in the control. We suggest that NO in high concentration induces the generation of ROS which subsequently causes severe oxidative damage to proteins crucial to the process of spore germination of P. expansum.

  10. Analysis of oxidative DNA damage after human dietary supplementation with linoleic acid.

    PubMed

    de Kok, T M C M; Zwingman, I; Moonen, E J; Schilderman, P A E L; Rhijnsburger, E; Haenen, G R M M; Kleinjans, J C S

    2003-03-01

    It has been hypothesized that oxygen radicals generated by peroxidation of dietary linoleic acid may induce genetic damage and thereby increase cancer risk. We examined the effect of dietary supplementation with linoleic acid on the levels of oxidative DNA damage in peripheral lymphocytes and on the blood plasma antioxidant potential. Thirty volunteers received during 6 weeks either a high dose of linoleic acid (15 g/day), an intermediate dose of linoleic acid (7.5 g/day) or an isocaloric supplement without linoleic acid (15 g palmitic acid/day). After the intervention, no significant increase in oxidative DNA damage, measured as relative amounts of 7,8-dihydro-8-oxo-2'-deoxyguanosine (8-oxodG) in DNA from peripheral lymphocytes, was observed in both high and intermediate linoleic acid-supplemented groups (increase of respectively 13 and 21%; P>0.05). Also, the differences between levels of oxidative DNA damage in the high or intermediate linoleic acid-supplemented group and the control group receiving palmitic acid (23% decrease) were not significant. Furthermore, no statistically significant differences were found between the total antioxidant capacities of blood plasma from the different experimental groups. Plasma levels of malondialdehyde, an important end-product of lipid peroxidation, were not increased after supplementation, nor were effects found on the plasma concentrations of retinol, alpha-tocopherol and beta-carotene. Despite the experimental design that excludes several forms of bias introduced in studies based on modulation of dietary composition, our results provide no indication of increased oxidative stress or genetic damage as a result of increased dietary intake of linoleic acid. Therefore, we see no scientific basis to reconsider the public health policy to stimulate the intake of polyunsaturated fatty acids aimed at the reduction of coronary heart diseases.

  11. Age-related differences in experimental stroke: possible involvement of mitochondrial dysfunction and oxidative damage.

    PubMed

    Li, Nanlin; Kong, Xiangwei; Ye, Ruidong; Yang, Qianzi; Han, Junliang; Xiong, Lize

    2011-06-01

    Age is the single most important risk factor for cerebral stroke. Unfortunately, the effect of age on ischemic brain damage is less clear. In this study, we sought to examine the potential influence of aging on the histologic and functional outcomes after ischemia. Juvenile (4 weeks of age), young adult (4 months of age), mid-aged (11-12 months of age), and aged (18-19 months of age) mice were subjected to transient middle cerebral artery occlusion. There was no remarkable difference of infarct volume on postoperative days 1 and 3. However, on postoperative day 7, aged mice exhibited significantly worsened infarct volume compared with juvenile and young mice. Intriguingly, the increase of infarct volume was most prominent in the striatal area rather than in cortex. Accordingly, aged mice displayed a slower and incomplete functional recovery after stroke. We further evaluated the effects of aging on the oxidative damage and mitochondrial dysfunction following ischemia. Brain tissues were assayed for lipid, DNA, and protein peroxidation products, mitochondrial enzyme activities, mitochondrial membrane potential, production of reactive oxygen species, and antioxidant activities. Aging was associated with declined mitochondrial function and antioxidant detoxification following ischemia, thereby inducing a deteriorated oxidative damage. Regional subanalyses demonstrated that, in accordance with infarct area, the pro-oxidant/antioxidant imbalance occurred more prominently in subcortical areas. Collectively, these findings suggest mitochondria-mediated oxidative damage may be involved in the age-related aggravated injury in subcortical areas. Mitochondrial protection could be a promising target for neuroprotective therapy, especially in the aged population.

  12. Design and Production of Damage-Resistant Tray Pack Containers

    DTIC Science & Technology

    1985-07-01

    U) (01 ECHNICAL REPORT AD _____ 4ATICK/TR-86/008 < DESIGN AND PRODUCTION OF DAMAGE-RESISTANT TRAY PACK CONTAINE’.RS BY D I RICHARD D. CUMMINGS JULY...REPORT & PERIOO COVEREDDESIGN AND PRODUCTION OP DAMAGE-RESISTANT FINAL REPORT TRAY PACK CON’TAINERS 13 APRIL 1984 - 31 JULY 1985 G. PERFORMING ORG...Cont"nue on iee ,ide I ne.esar, od Identif, by bloPk nub.,) * TRAY PACK(S) LOADS CONTAINERS DAMAGE PACKAGING LOADING (HANDLING) SHIPPING TESTS 20

  13. 17β-Estradiol Alters Oxidative Stress Response Protein Expression and Oxidative Damage in the Uterus

    PubMed Central

    Yuan, Lisi; Dietrich, Alicia K.; Nardulli, Ann M.

    2014-01-01

    The steroid hormone 17β-estradiol (E2) has profound effects on the uterus. However, with the E2-induced increase in uterine cell proliferation and metabolism comes increased production of reactive oxygen species (ROS). We examined the expression of an interactive network of oxidative stress response proteins including thioredoxin (Trx), Cu/Zn superoxide dismutase (SOD1), apurinic endonuclease (Ape1), and protein disulfide isomerase (PDI). We demonstrated that treatment of ovariectomized C57BL/6J female mice with E2 increased the mRNA and protein levels of Trx, but decreased SOD1 and Ape1 mRNA and protein expression. In contrast, E2 treatment increased PDI protein levels but had no effect on PDI transcript levels.Interestingly, E2 treatment also increased two markers of cellular damage, lipid peroxidation and protein carbonylation. Our studies suggest that the decreased expression of SOD1 and Ape1 caused by E2 treatment may in the long term result in disruption of ROS regulation and play a role in endometrial carcinogenesis. PMID:24103313

  14. Evaluation of Oxidation Damage in Thermal Barrier Coating Systems

    NASA Technical Reports Server (NTRS)

    Zhu, Dongming; Miller, Robert A.

    1996-01-01

    A method based on the technique of dilatometry has been established to quantitatively evaluate the interfacial damage due to the oxidation in a thermal barrier coating system. Strain isolation and adhesion coefficients have been proposed to characterize the thermal barrier coating (TBC) performance based on its thermal expansion behavior. It has been found that, for a thermal barrier coating system consisting of ZrO2-8%Y2O3/FeCrAlY/4140 steel substrate, the oxidation of the bond coat and substrate significantly reduced the ceramic coating adherence, as inferred from the dilatometry measurements. The in-situ thermal expansion measurements under 30 deg C to 700 deg C thermal cycling in air showed that the adhesion coefficient, A(sub i) decreased by 25% during the first 35 oxidation cycles. Metallography showed that delamination occurred at both the ceramic/bond coat and bond coat/substrate interfaces. In addition, the strain isolation effect has been improved by increasing the FeCrAlY bond coat thickness. The strain isolation coefficient, Si, increased from about 0.04 to 0.25, as the bond coat thickness changed from 0.1 mm to 1.0 mm. It may be possible to design optimum values of strain isolation and interface adhesion coefficients to achieve the best TBC performance.

  15. Mitochondrial dysfunction and oxidative damage in parkin-deficient mice.

    PubMed

    Palacino, James J; Sagi, Dijana; Goldberg, Matthew S; Krauss, Stefan; Motz, Claudia; Wacker, Maik; Klose, Joachim; Shen, Jie

    2004-04-30

    Loss-of-function mutations in parkin are the predominant cause of familial Parkinson's disease. We previously reported that parkin-/- mice exhibit nigrostriatal deficits in the absence of nigral degeneration. Parkin has been shown to function as an E3 ubiquitin ligase. Loss of parkin function, therefore, has been hypothesized to cause nigral degeneration via an aberrant accumulation of its substrates. Here we employed a proteomic approach to determine whether loss of parkin function results in alterations in abundance and/or modification of proteins in the ventral midbrain of parkin-/- mice. Two-dimensional gel electrophoresis followed by mass spectrometry revealed decreased abundance of a number of proteins involved in mitochondrial function or oxidative stress. Consistent with reductions in several subunits of complexes I and IV, functional assays showed reductions in respiratory capacity of striatal mitochondria isolated from parkin-/- mice. Electron microscopic analysis revealed no gross morphological abnormalities in striatal mitochondria of parkin-/- mice. In addition, parkin-/- mice showed a delayed rate of weight gain, suggesting broader metabolic abnormalities. Accompanying these deficits in mitochondrial function, parkin-/- mice also exhibited decreased levels of proteins involved in protection from oxidative stress. Consistent with these findings, parkin-/- mice showed decreased serum antioxidant capacity and increased protein and lipid peroxidation. The combination of proteomic, genetic, and physiological analyses reveal an essential role for parkin in the regulation of mitochondrial function and provide the first direct evidence of mitochondrial dysfunction and oxidative damage in the absence of nigral degeneration in a genetic mouse model of Parkinson's disease.

  16. Protective Effect of Folic Acid on Oxidative DNA Damage

    PubMed Central

    Guo, Xiaojuan; Cui, Huan; Zhang, Haiyang; Guan, Xiaoju; Zhang, Zheng; Jia, Chaonan; Wu, Jia; Yang, Hui; Qiu, Wenting; Zhang, Chuanwu; Yang, Zuopeng; Chen, Zhu; Mao, Guangyun

    2015-01-01

    Abstract Although previous reports have linked DNA damage with both transmissions across generations as well as our own survival, it is unknown how to reverse the lesion. Based on the data from a Randomized, Double-blind, Placebo Controlled Clinical Trial, this study aimed to assess the efficacy of folic acid supplementation (FAS) on DNA oxidative damage reversal. In this randomized clinical trial (RCT), a total of 450 participants were enrolled and randomly assigned to 3 groups to receive folic acid (FA) 0.4 mg/day (low-FA), 0.8 mg/day (high-FA), or placebo (control) for 8 weeks. The urinary 8-hydroxy-2’-deoxyguanosine (8-OHdG) and creatinine (Cr) concentration at pre- and post-FAS were measured with modified enzyme-linked immunosorbent assay (ELISA) and high-performance liquid chromatography (HPLC), respectively. A multivariate general linear model was applied to assess the individual effects of FAS and the joint effects between FAS and hypercholesterolemia on oxidative DNA damage improvement. This clinical trial was registered with ClinicalTrials.gov, number NCT02235948. Of the 438 subjects that received FA fortification or placebo, the median (first quartile, third quartile) of urinary 8-OHdG/Cr for placebo, low-FA, and high-FA groups were 58.19 (43.90, 82.26), 53.51 (38.97, 72.74), 54.73 (39.58, 76.63) ng/mg at baseline and 57.77 (44.35, 81.33), 51.73 (38.20, 71.30), and 50.65 (37.64, 76.17) ng/mg at the 56th day, respectively. A significant decrease of urinary 8-OHdG was observed after 56 days FA fortification (P < 0.001). Compared with the placebo, after adjusting for some potential confounding factors, including the baseline urinary 8-OHdG/Cr, the urinary 8-OHdG/Cr concentration significantly decreased after 56 days FAS [β (95% confidence interval) = −0.88 (−1.62, −0.14) and P = 0.020 for low-FA; and β (95% confidence interval) = −2.68 (−3.42, −1.94) and P < 0.001 for high-FA] in a dose-response fashion (Ptrend

  17. Transparent conducting oxides and production thereof

    SciTech Connect

    Gessert, Timothy A; Yoshida, Yuki; Coutts, Timothy J

    2014-05-27

    Transparent conducting oxides and production thereof are disclosed. An exemplary method of producing a transparent conducting oxide (TCO) material may comprise: providing a TCO target (110) doped with either a high-permittivity oxide or a low-permittivity oxide in a process chamber (100). The method may also comprise depositing a metal oxide on the target (110) to form a thin film having enhanced optical properties without substantially decreasing electrical quality.

  18. Transparent conducting oxides and production thereof

    DOEpatents

    Gessert, Timothy A.; Yoshida, Yuki; Coutts, Timothy J.

    2014-06-10

    Transparent conducting oxides and production thereof are disclosed. An exemplary method of producing a transparent conducting oxide (TCO) material may comprise: providing a TCO target doped with either a high-permittivity oxide or a low-permittivity oxide in a process chamber. The method may also comprise depositing a metal oxide on the target in the process chamber to form a thin film having enhanced optical properties without substantially decreasing electrical quality.

  19. Molecular pathophysiology of impaired glucose metabolism, mitochondrial dysfunction, and oxidative DNA damage in Alzheimer's disease brain.

    PubMed

    Abolhassani, Nona; Leon, Julio; Sheng, Zijing; Oka, Sugako; Hamasaki, Hideomi; Iwaki, Toru; Nakabeppu, Yusaku

    2017-01-01

    In normal brain, neurons in the cortex and hippocampus produce insulin, which modulates glucose metabolism and cognitive functions. It has been shown that insulin resistance impairs glucose metabolism and mitochondrial function, thus increasing production of reactive oxygen species. Recent progress in Alzheimer's disease (AD) research revealed that insulin production and signaling are severely impaired in AD brain, thereby resulting in mitochondrial dysfunction and increased oxidative stress. Among possible oxidative DNA lesions, 8-oxoguanine (8-oxoG) is highly accumulated in the brain of AD patients. Previously we have shown that incorporating 8-oxoG in nuclear and mitochondrial DNA promotes MUTYH (adenine DNA glycosylase) dependent neurodegeneration. Moreover, cortical neurons prepared from MTH1 (8-oxo-dGTPase)/OGG1 (8-oxoG DNA glycosylase)-double deficient adult mouse brains is shown to exhibit significantly poor neuritogenesis in vitro with increased 8-oxoG accumulation in mitochondrial DNA in the absence of antioxidants. Therefore, 8-oxoG can be considered involved in the neurodegenerative process in AD brain. In mild cognitive impairment, mitochondrial dysfunction and oxidative damage may induce synaptic dysfunction due to energy failures in neurons thus resulting in impaired cognitive function. If such abnormality lasts long, it can lead to vicious cycles of oxidative damage, which may then trigger the neurodegenerative process seen in Alzheimer type dementia. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  20. Oxidative damage, skin aging, antioxidants and a novel antioxidant rating system.

    PubMed

    Palmer, Debbie M; Kitchin, Jennifer Silverman

    2010-01-01

    It is believed that oxidative stress is caused by an imbalance between the production of reactive oxygen and a biological system's ability to neutralize the reactive intermediates. Oxidative damage occurs because of both intrinsic and extrinsic mechanisms. Together, intrinsic and extrinsic damage are the primary causes of skin aging. The skin uses a series of intrinsic antioxidants to protect itself from free radical damage. Naturally occurring extrinsic antioxidants have also been widely shown to offset and alleviate these changes. Unlike sunscreens, which have an SPF rating system to guide consumers in their purchases, there is no widely accepted method to choose antioxidant anti-aging products. ORAC (Oxygen Radical Absorbance Capacity) and ABEL-RAC (Analysis By Emitted Light-Relative Antioxidant Capacity), are both accepted worldwide as a standard measure of the antioxidant capacity of foods, and are rating systems that could be applied to all antioxidant skincare products. The standardization of antioxidant creams could revolutionize the cosmeceutical market and give physicians and consumers the ability to compare and choose effectively.

  1. Oxidative damage to DNA during aging: 8-hydroxy-2'-deoxyguanosine in rat organ DNA and urine.

    PubMed Central

    Fraga, C G; Shigenaga, M K; Park, J W; Degan, P; Ames, B N

    1990-01-01

    Oxidative damage to DNA is shown to be extensive and could be a major cause of the physiological changes associated with aging and the degenerative diseases related to aging such as cancer. The oxidized nucleoside, 8-hydroxy-2'-deoxyguanosine (oh8dG), one of the approximately 20 known oxidative DNA damage products, has been measured in DNA isolated from various organs of Fischer 344 rats of different ages. oh8dG was present in the DNA isolated from all the organs studied: liver, brain, kidney, intestine, and testes. Steady-state levels of oh8dG ranged from 8 to 73 residues per 10(6) deoxyguanosine residues or 0.2-2.0 x 10(5) residues per cell. Levels of oh8dG in DNA increased with age in liver, kidney, and intestine but remained unchanged in brain and testes. The urinary excretion of oh8dG, which presumably reflects its repair from DNA by nuclease activity, decreased with age from 481 to 165 pmol per kg of body weight per day for urine obtained from 2-month- and 25-month-old rats, respectively. 8-Hydroxyguanine, the proposed repair product of a glycosylase activity, was also assayed in the urine. We estimate approximately 9 x 10(4) oxidative hits to DNA per cell per day in the rat. The results suggest that the age-dependent accumulation of oh8dG residues observed in DNA from liver, kidney, and intestine is principally due to the slow loss of DNA nuclease activity; however, an increase in the rate of oxidative DNA damage cannot be ruled out. PMID:2352934

  2. The basic chemistry of exercise-induced DNA oxidation: oxidative damage, redox signaling, and their interplay.

    PubMed

    Cobley, James N; Margaritelis, Nikos V; Morton, James P; Close, Graeme L; Nikolaidis, Michalis G; Malone, John K

    2015-01-01

    Acute exercise increases reactive oxygen and nitrogen species generation. This phenomenon is associated with two major outcomes: (1) redox signaling and (2) macromolecule damage. Mechanistic knowledge of how exercise-induced redox signaling and macromolecule damage are interlinked is limited. This review focuses on the interplay between exercise-induced redox signaling and DNA damage, using hydroxyl radical ((·)OH) and hydrogen peroxide (H2O2) as exemplars. It is postulated that the biological fate of H2O2 links the two processes and thus represents a bifurcation point between redox signaling and damage. Indeed, H2O2 can participate in two electron signaling reactions but its diffusion and chemical properties permit DNA oxidation following reaction with transition metals and (·)OH generation. It is also considered that the sensing of DNA oxidation by repair proteins constitutes a non-canonical redox signaling mechanism. Further layers of interaction are provided by the redox regulation of DNA repair proteins and their capacity to modulate intracellular H2O2 levels. Overall, exercise-induced redox signaling and DNA damage may be interlinked to a greater extent than was previously thought but this requires further investigation.

  3. DNA damage and TNFalpha cytokine production in hairdressers with contact dermatitis.

    PubMed

    Cavallo, Delia; Ursini, Cinzia Lucia; Setini, Andrea; Chianese, Concetta; Cristaudo, Antonio; Iavicoli, Sergio

    2005-09-01

    The present work was undertaken to study in hairdressers exposed to several irritants and allergens (prevalently hair-dyeing) and affected by hand contact dermatitis the possible correlation between exposure and direct-oxidative DNA damage, production of tumour necrosis factor alpha (TNFalpha) and allergic inflammatory disease. We evaluated in 19 hairdressers with hand contact dermatitis, 14 allergic contact dermatitis (ACD) and 5 irritant contact dermatitis (ICD) and in a selected control group TNFalpha serum levels by ELISA and direct-oxidative DNA damage by Fpg (formamido-pyrimidine-glycosylase)-modified Comet test on blood. Hairdressers were divided on the basis of number of hair-dyeing carried out weekly into 2 groups: low-exposure (<60 hair-dyeing/week) and high-exposure hairdressers (>or=60 hair-dyeing/week) that reflect also the exposure to other allergens and irritants and 2 different tasks (hairdressers and apprentice hairdressers, respectively). Serum levels of TNFalpha in hairdressers with ACD were significantly higher than controls with a correlation to exposure level. Significant DNA damage in ICD hairdressers with higher exposure as compared to controls was found. These findings suggest that occupational exposure can induce in hairdressers, particularly ICD, DNA damage, increase the TNFa levels particularly in ACD and induce allergic sensitization, suggesting a relationship between direct-oxidative DNA damage, TNFalpha production and allergic inflammatory disease.

  4. Oxidative stress, progressive damage in the substantia nigra and plasma dopamine oxidation, in rats chronically exposed to ozone.

    PubMed

    Santiago-López, D; Bautista-Martínez, J A; Reyes-Hernandez, C I; Aguilar-Martínez, M; Rivas-Arancibia, S

    2010-09-01

    The purpose of our work was to determine the effects of oxidative stress on the neurodegeneration process in the substantia nigra, and to evaluate dopamine-oxidation metabolites in the plasma using a cyclic voltammetry (CV) technique. We have also studied the correlation between the increases in oxidized dopamine-species levels with the severity of lipid-peroxidation in the plasma. Sixty-four male Wistar rats were divided into four experimental groups and received air (Group I, control) or ozone (0.25 ppm) daily by inhalation for 4h for 15 (Group II), 30 (Group III), and 60 (Group IV) days. The brains were processed for immunohistochemical location of dopamine and p53 in the substantia nigra. Plasma collected from these animals was assayed for oxidized dopamine products using CV and lipid-peroxidation levels were measured. Our results indicate that chronic exposure to low O(3) doses causes that the number of dopaminergic neurons decreased, and p53-immunoreactive cells increases until 30 days; which was a function of the time of exposure to ozone. Oxidative stress produces a significant increase in the levels of the dopamine quinones (DAQs) that correlated well (r=0.962) with lipid peroxides in the plasma during the study period. These results suggest that DAQ could be a reliable, peripheral oxidative indicator of nigral dopaminergic damage in the brain. (c) 2010 Elsevier Ireland Ltd. All rights reserved.

  5. NEIL2 protects against oxidative DNA damage induced by sidestream smoke in human cells.

    PubMed

    Sarker, Altaf H; Chatterjee, Arpita; Williams, Monique; Lin, Sabrina; Havel, Christopher; Jacob, Peyton; Boldogh, Istvan; Hazra, Tapas K; Talbot, Prudence; Hang, Bo

    2014-01-01

    Secondhand smoke (SHS) is a confirmed lung carcinogen that introduces thousands of toxic chemicals into the lungs. SHS contains chemicals that have been implicated in causing oxidative DNA damage in the airway epithelium. Although DNA repair is considered a key defensive mechanism against various environmental attacks, such as cigarette smoking, the associations of individual repair enzymes with susceptibility to lung cancer are largely unknown. This study investigated the role of NEIL2, a DNA glycosylase excising oxidative base lesions, in human lung cells treated with sidestream smoke (SSS), the main component of SHS. To do so, we generated NEIL2 knockdown cells using siRNA-technology and exposed them to SSS-laden medium. Representative SSS chemical compounds in the medium were analyzed by mass spectrometry. An increased production of reactive oxygen species (ROS) in SSS-exposed cells was detected through the fluorescent detection and the induction of HIF-1α. The long amplicon-quantitative PCR (LA-QPCR) assay detected significant dose-dependent increases of oxidative DNA damage in the HPRT gene of cultured human pulmonary fibroblasts (hPF) and BEAS-2B epithelial cells exposed to SSS for 24 h. These data suggest that SSS exposure increased oxidative stress, which could contribute to SSS-mediated toxicity. siRNA knockdown of NEIL2 in hPF and HEK 293 cells exposed to SSS for 24 h resulted in significantly more oxidative DNA damage in HPRT and POLB than in cells with control siRNA. Taken together, our data strongly suggest that decreased repair of oxidative DNA base lesions due to an impaired NEIL2 expression in non-smokers exposed to SSS would lead to accumulation of mutations in genomic DNA of lung cells over time, thus contributing to the onset of SSS-induced lung cancer.

  6. Oxidative damage induced in Vicia faba by coke plant wastewater.

    PubMed

    Liu, Yuxiang; Lv, Yongkang

    2011-10-01

    The present study investigated toxic impacts of coke plant wastewater over a concentration gradient of COD( Cr) 40-640 mg/l on malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in roots and leaves of Vicia faba. MDA levels and SOD activities were significantly increased at all concentrations both in roots and leaves of Vicia faba; CAT and POD activities were significantly enhanced in roots at low concentrations and were significantly decreased at high concentrations (COD(Cr) 320 and 640 mg/l for CAT; COD( Cr) 640 mg/l for POD). In leaves, CAT and POD activities remained enhanced at all concentration and did not show significant difference at COD( Cr) 640 mg/l for CAT and COD(Cr) 40, 640 mg/l for POD. These results suggest that coke plant wastewater can cause oxidative damage in roots and leaves of Vicia faba and root enzymes seemed more sensitive to the wastewater.

  7. Oxidatively induced DNA damage and its repair in cancer.

    PubMed

    Dizdaroglu, Miral

    2015-01-01

    Oxidatively induced DNA damage is caused in living organisms by endogenous and exogenous reactive species. DNA lesions resulting from this type of damage are mutagenic and cytotoxic and, if not repaired, can cause genetic instability that may lead to disease processes including carcinogenesis. Living organisms possess DNA repair mechanisms that include a variety of pathways to repair multiple DNA lesions. Mutations and polymorphisms also occur in DNA repair genes adversely affecting DNA repair systems. Cancer tissues overexpress DNA repair proteins and thus develop greater DNA repair capacity than normal tissues. Increased DNA repair in tumors that removes DNA lesions before they become toxic is a major mechanism for development of resistance to therapy, affecting patient survival. Accumulated evidence suggests that DNA repair capacity may be a predictive biomarker for patient response to therapy. Thus, knowledge of DNA protein expressions in normal and cancerous tissues may help predict and guide development of treatments and yield the best therapeutic response. DNA repair proteins constitute targets for inhibitors to overcome the resistance of tumors to therapy. Inhibitors of DNA repair for combination therapy or as single agents for monotherapy may help selectively kill tumors, potentially leading to personalized therapy. Numerous inhibitors have been developed and are being tested in clinical trials. The efficacy of some inhibitors in therapy has been demonstrated in patients. Further development of inhibitors of DNA repair proteins is globally underway to help eradicate cancer.

  8. Calculation of the stabilization energies of oxidatively damaged guanine base pairs with guanine.

    PubMed

    Suzuki, Masayo; Kino, Katsuhito; Morikawa, Masayuki; Kobayashi, Takanobu; Komori, Rie; Miyazawa, Hiroshi

    2012-06-01

    DNA is constantly exposed to endogenous and exogenous oxidative stresses. Damaged DNA can cause mutations, which may increase the risk of developing cancer and other diseases. G:C-C:G transversions are caused by various oxidative stresses. 2,2,4-Triamino-5(2H)-oxazolone (Oz), guanidinohydantoin (Gh)/iminoallantoin (Ia) and spiro-imino-dihydantoin (Sp) are known products of oxidative guanine damage. These damaged bases can base pair with guanine and cause G:C-C:G transversions. In this study, the stabilization energies of these bases paired with guanine were calculated in vacuo and in water. The calculated stabilization energies of the Ia:G base pairs were similar to that of the native C:G base pair, and both bases pairs have three hydrogen bonds. By contrast, the calculated stabilization energies of Gh:G, which form two hydrogen bonds, were lower than the Ia:G base pairs, suggesting that the stabilization energy depends on the number of hydrogen bonds. In addition, the Sp:G base pairs were less stable than the Ia:G base pairs. Furthermore, calculations showed that the Oz:G base pairs were less stable than the Ia:G, Gh:G and Sp:G base pairs, even though experimental results showed that incorporation of guanine opposite Oz is more efficient than that opposite Gh/Ia and Sp.

  9. Fermented goat milk improves antioxidant status and protects from oxidative damage to biomolecules during anemia recovery.

    PubMed

    Moreno-Fernandez, Jorge; Diaz-Castro, Javier; Alférez, María Jm; Boesch, Christine; Nestares, Teresa; López-Aliaga, Inmaculada

    2017-03-01

    Iron deficiency anemia (IDA) is one of the most common nutritional problems in the world, and it is accepted that reactive oxygen species (ROS) production is altered during IDA. The aim of this study was to assess the influence of fermented goat and cow milks on enzymatic antioxidant activities and gene expression, and their role in protecting from oxidative damage during anemia recovery. After feeding the fermented milks-based diets (cow or goat), a significant elevation of some antioxidant endogenous enzymes was found, together with an increase in total antioxidant status (TAS), and a decrease in 8-hydroxy-2'-deoxyguanosine (8-OHdG) was recorded in animals consuming fermented goat milk-based diet. In contrast, DNA strand breaks, hydroperoxides, 15-F2t-isoprostanes and protein carbonyl groups were lower in some tissues in animals fed fermented goat milk-based diet, revealing an improvement in both systemic and cellular antioxidant activity of plasma and tissues due to fermented goat milk consumption. Fermented goat milk consumption induces a protective increase in TAS together with lower oxidative damage biomarkers, revealing that the milk protects main cell bioconstituents (lipids, protein, DNA, prostaglandins) from evoked oxidative damage during anemia recovery. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  10. Oxidative stress and DNA damage in horses naturally infected with Theileria equi.

    PubMed

    Radakovic, M; Davitkov, D; Borozan, S; Stojanovic, S; Stevanovic, J; Krstic, V; Stanimirovic, Z

    2016-11-01

    The aim of this study was to determine the concentrations of oxidative stress parameters and DNA damage in horses infected by Theileria equi. Initial screening of 110 horses with duplex PCR enabled the selection of 30 infected horses with T. equi and 30 free of infection (control). Specimens from the 60 horses were further analysed by determining the following oxidative stress parameters: extent of haemolysis (EH), plasma free haemoglobin (PHb), catalase (CAT), Cu,Zn superoxide dismutase (SOD1), paraoxonase (PON1), nitrite (NO2(-)), total nitrate and nitrite (NOx), malondialdehyde (MDA) and free thiol groups (-SH). In addition, relative distribution of lactate dehydrogenase (LDH1-LDH5) activity and the DNA-damaging effects of T. equi infection were evaluated. Compared to control horses, horses infected with T. equi had significantly higher SOD1 activities (P <0.05) and PHb (P <0.01), NO2(-) (P <0.001), NOx (P <0.05) and MDA concentrations (P <0.001), and significantly lower EH (P <0.001), CAT (P <0.01) and PON1 (P <0.001) activities, and thiol group concentrations (P <0.05). The comet assay demonstrated significantly increased DNA damage in T. equi infected cells compared to non-infected cells (P <0.001). Infected horses had significantly increased LDH5 isoenzyme activities (P <0.05). There was higher production of ROS/RNS in T. equi-infected horses, which resulted in changes in osmotic fragility, damage to lipids, proteins and DNA, haemolysis and hepatocellular damage. Oxidative stress in horses naturally infected with T. equi could contribute to the pathogenesis of the infection. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Antioxidant-mediated protective effect of potato peel extract in erythrocytes against oxidative damage.

    PubMed

    Singh, Nandita; Rajini, P S

    2008-05-28

    Potato peels are waste by-product of the potato processing industry. They are reportedly rich in polyphenols. Our earlier studies have shown that extracts derived from potato peel (PPE) possess strong antioxidant activity in chemical and biological model systems in vitro, attributable to its polyphenolic content. The main objective of this study was to investigate the ability of PPE to protect erythrocytes against oxidative damage, in vitro. The protection rendered by PPE in erythrocytes was studied in terms of resistance to oxidative damage, morphological alterations as well as membrane structural alterations. The total polyphenolic content in PPE was found to be 3.93 mg/g powder. The major phenolic acids present in PPE were predominantly: gallic acid, caffeic acid, chlorogenic acid and protocatechuic acid. We chose the experimental prooxidant system: FeSO(4) and ascorbic acid to induce lipid peroxidation in rat RBCs and human RBC membranes. PPE was found to inhibit lipid peroxidation with similar effectiveness in both the systems (about 80-85% inhibition by PPE at 2.5 mg/ml). While PPE per se did not cause any morphological alteration in the erythrocytes, under the experimental conditions, PPE significantly inhibited the H(2)O(2)-induced morphological alterations in rat RBCs as revealed by scanning electron microscopy. Further, PPE was found to offer significant protection to human erythrocyte membrane proteins from oxidative damage induced by ferrous-ascorbate. In conclusion, our results indicate that PPE is capable of protecting erythrocytes against oxidative damage probably by acting as a strong antioxidant.

  12. Measurement of oxidative DNA damage by gas chromatography-mass spectrometry: ethanethiol prevents artifactual generation of oxidized DNA bases.

    PubMed

    Jenner, A; England, T G; Aruoma, O I; Halliwell, B

    1998-04-15

    Analysis of oxidative damage to DNA bases by GC-MS enables identification of a range of base oxidation products, but requires a derivatization procedure. However, derivatization at high temperature in the presence of air can cause 'artifactual' oxidation of some undamaged bases, leading to an overestimation of their oxidation products, including 8-hydroxyguanine. Therefore derivatization conditions that could minimize this problem were investigated. Decreasing derivatization temperature to 23 degrees C lowered levels of 8-hydroxyguanine, 8-hydroxyadenine, 5-hydroxycytosine and 5-(hydroxymethyl)uracil measured by GC-MS in hydrolysed calf thymus DNA. Addition of the reducing agent ethanethiol (5%, v/v) to DNA samples during trimethylsilylation at 90 degrees C also decreased levels of these four oxidized DNA bases as well as 5-hydroxyuracil. Removal of guanine from hydrolysed DNA samples by treatment with guanase, prior to derivatization, resulted in 8-hydroxyguanine levels (54-59 pmol/mg of DNA) that were significantly lower than samples not pretreated with guanase, independent of the derivatization conditions used. Only hydrolysed DNA samples that were derivatized at 23 degrees C in the presence of ethanethiol produced 8-hydroxyguanine levels (56+/-8 pmol/mg of DNA) that were as low as those of guanase-pretreated samples. Levels of other oxidized bases were similar to samples derivatized at 23 degrees C without ethanethiol, except for 5-hydroxycytosine and 5-hydroxyuracil, which were further decreased by ethanethiol. Levels of 8-hydroxyguanine, 8-hydroxyadenine and 5-hydroxycytosine measured in hydrolysed calf thymus DNA by the improved procedures described here were comparable with those reported previously by HPLC with electrochemical detection and by GC-MS with prepurification to remove undamaged base. We conclude that artifactual oxidation of DNA bases during derivatization can be prevented by decreasing the temperature to 23 degrees C, removing air from the

  13. Cadmium Chloride Induces DNA Damage and Apoptosis of Human Liver Carcinoma Cells via Oxidative Stress.

    PubMed

    Skipper, Anthony; Sims, Jennifer N; Yedjou, Clement G; Tchounwou, Paul B

    2016-01-02

    Cadmium is a heavy metal that has been shown to cause its toxicity in humans and animals. Many documented studies have shown that cadmium produces various genotoxic effects such as DNA damage and chromosomal aberrations. Ailments such as bone disease, renal damage, and several forms of cancer are attributed to overexposure to cadmium. Although there have been numerous studies examining the effects of cadmium in animal models and a few case studies involving communities where cadmium contamination has occurred, its molecular mechanisms of action are not fully elucidated. In this research, we hypothesized that oxidative stress plays a key role in cadmium chloride-induced toxicity, DNA damage, and apoptosis of human liver carcinoma (HepG₂) cells. To test our hypothesis, cell viability was determined by MTT assay. Lipid hydroperoxide content stress was estimated by lipid peroxidation assay. Genotoxic damage was tested by the means of alkaline single cell gel electrophoresis (Comet) assay. Cell apoptosis was measured by flow cytometry assessment (Annexin-V/PI assay). The result of MTT assay indicated that cadmium chloride induces toxicity to HepG₂ cells in a concentration-dependent manner, showing a 48 hr-LD50 of 3.6 µg/mL. Data generated from lipid peroxidation assay resulted in a significant (p < 0.05) increase of hydroperoxide production, specifically at the highest concentration tested. Data obtained from the Comet assay indicated that cadmium chloride causes DNA damage in HepG₂ cells in a concentration-dependent manner. A strong concentration-response relationship (p < 0.05) was recorded between annexin V positive cells and cadmium chloride exposure. In summary, these in vitro studies provide clear evidence that cadmium chloride induces oxidative stress, DNA damage, and programmed cell death in human liver carcinoma (HepG₂) cells.

  14. Acetylsalicylic acid provides cerebrovascular protection from oxidant damage in salt-loaded stroke-prone rats.

    PubMed

    Ishizuka, Toshiaki; Niwa, Atsuko; Tabuchi, Masaki; Ooshima, Kana; Higashino, Hideaki

    2008-03-26

    Inflammatory processes may play a pivotal role in the pathogenesis of cerebrovascular injury in salt-loaded stroke-prone spontaneously hypertensive rats (SHRSP). Recent reports revealed that acetylsalicylic acid (aspirin) has anti-oxidative properties and elicits nitric oxide release by a direct activation of the endothelial NO synthase. The present study was designed to determine whether low-dose aspirin might prevent cerebrovascular injury in salt-loaded SHRSP by protecting oxidative damage. Nine-week-old SHRSP were fed a 0.4% NaCl or a 4% NaCl diet with or without treatment by naproxen (20 mg/kg/day), salicylic acid (5 mg/kg/day), or aspirin (5 mg/kg/day) for 5 weeks. Blood pressure, blood brain barrier impairment, mortality, and the parameters of cerebrovascular inflammation and damage were compared among them. High salt intake in SHRSP significantly increased blood brain barrier impairment and early mortality, which were suppressed by treatment with aspirin independent of changes in blood pressure. Salt loading significantly increased superoxide production in basilar arteries of SHRSP, which were significantly suppressed by treatment with aspirin. Salt loading also significantly decreased NOS activity in the basilar arteries of SHRSP, which were significantly improved by treatment with aspirin. At 5 weeks after salt loading, macrophage accumulation and matrix metalloproteinase-9 activity at the stroke-negative area in cerebral cortex of SHRSP were significantly reduced by treatment with aspirin. These results suggest that low-dose aspirin may exert protective effects against cerebrovascular inflammation and damage by salt loading through down-regulation of superoxide production and induction of nitric oxide synthesis.

  15. Renal damage mediated by oxidative stress: a hypothesis of protective effects of red wine.

    PubMed

    Rodrigo, Ramón; Rivera, Gonzalo

    2002-08-01

    Over the last decade, oxidative stress has been implicated in the pathogenesis of a wide variety of seemingly unrelated renal diseases. Epidemiological studies have documented an association of moderate wine consumption with a decreased risk of cardiovascular and neurological diseases; however, similar studies in the kidney are still lacking. The kidney is an organ highly vulnerable to damage caused by reactive oxygen species (ROS), likely due to the abundance of polyunsaturated fatty acids in the composition of renal lipids. ROS are involved in the pathogenic mechanism of conditions such as glomerulosclerosis and tubulointerstitial fibrosis. The health benefits of moderate consumption of red wine can be partly attributed to its antioxidant properties. Indeed, the kidney antioxidant defense system is enhanced after chronic exposure to moderate amounts of wine, a response arising from the combined effects of ethanol and the nonalcoholic components, mainly polyphenols. Polyphenols behave as potent ROS scavengers and metal chelators; ethanol, in turn, modulates the activity of antioxidant enzymes. Therefore, a hypothesis that red wine causes a decreased vulnerability of the kidney to the oxidative challenges could be proposed. This view is partly supported by direct evidences indicating that wine and antioxidants isolated from red wine, as well as other antioxidants, significantly attenuate or prevent the oxidative damage to the kidney. The present hypothesis paper provides a collective body of evidence suggesting a protective role of moderate wine consumption against the production and progression of renal diseases, based on the existing concepts on the pathophysiology of kidney injury mediated by oxidative stress.

  16. Poly(ADP-ribose) protects vascular smooth muscle cells from oxidative DNA damage

    PubMed Central

    Zhang, Chao; Luo, Tao; Cui, Shijun; Gu, Yongquan; Bian, Chunjing; Chen, Yibin; Yu, Xiaochun; Wang, Zhonggao

    2015-01-01

    Vascular smooth muscle cells (VSMCs) undergo death during atherosclerosis, a widespread cardiovascular disease. Recent studies suggest that oxidative damage occurs in VSMCs and induces atherosclerosis. Here, we analyzed oxidative damage repair in VSMCs and found that VSMCs are hypersensitive to oxidative damage. Further analysis showed that oxidative damage repair in VSMCs is suppressed by a low level of poly (ADP-ribosyl)ation (PARylation), a key post-translational modification in oxidative damage repair. The low level of PARylation is not caused by the lack of PARP-1, the major poly(ADP-ribose) polymerase activated by oxidative damage. Instead, the expression of poly(ADP-ribose) glycohydrolase, PARG, the enzyme hydrolyzing poly(ADP-ribose), is significantly higher in VSMCs than that in the control cells. Using PARG inhibitor to suppress PARG activity facilitates oxidative damage-induced PARylation as well as DNA damage repair. Thus, our study demonstrates a novel molecular mechanism for oxidative damage-induced VSMCs death. This study also identifies the use of PARG inhibitors as a potential treatment for atherosclerosis. [BMB Reports 2015; 48(6): 354-359] PMID:25748172

  17. Methoxychlor causes mitochondrial dysfunction and oxidative damage in the mouse ovary

    SciTech Connect

    Gupta, R.K.; Schuh, R.A.; Fiskum, G.; Flaws, J.A. . E-mail: jflaws@epi.umaryland.edu

    2006-11-01

    Methoxychlor (MXC) is an organochlorine pesticide that reduces fertility in female rodents by causing ovarian atrophy, persistent estrous cyclicity, and antral follicle atresia (apoptotic cell death). Oxidative damage resulting from reactive oxygen species (ROS) generation has been demonstrated to lead to toxicant-induced cell death. Thus, this work tested the hypothesis that MXC causes oxidative damage to the mouse ovary and affects mitochondrial respiration in a manner that stimulates ROS production. For the in vitro experiments, mitochondria were collected from adult cycling mouse ovaries, treated with vehicle (dimethyl sulfoxide; DMSO) or MXC, and subjected to polarographic measurements of respiration. For the in vivo experiments, adult cycling CD-1 mice were dosed with either vehicle (sesame oil) or MXC for 20 days. After treatment, ovarian mitochondria were isolated and subjected to measurements of respiration and fluorimetric measurements of H{sub 2}O{sub 2} production. Some ovaries were also fixed and processed for immunohistochemistry using antibodies for ROS production markers: nitrotyrosine and 8-hydroxy-2'-deoxyguanosine (8-OHG). Ovaries from in vivo experiments were also used to measure the mRNA expression and activity of antioxidants such as Cu/Zn superoxide dismutase (SOD1), glutathione peroxidase (GPX), and catalase (CAT). The results indicate that MXC significantly impairs mitochondrial respiration, increases production of H{sub 2}O{sub 2}, causes more staining for nitrotyrosine and 8-OHG in antral follicles, and decreases the expression and activity of SOD1, GPX, and CAT as compared to controls. Collectively, these data indicate that MXC inhibits mitochondrial respiration, causes ROS production, and decreases antioxidant expression and activity in the ovary, specifically in the antral follicles. Therefore, it is possible that MXC causes atresia of ovarian antral follicles by inducing oxidative stress through mitochondrial production of ROS.

  18. Ibuprofen attenuates oxidative damage through NOX2 inhibition in Alzheimer’s Disease

    PubMed Central

    Wilkinson, Brandy L.; Cramer, Paige E.; Varvel, Nicholas H.; Reed-Geaghan, Erin; Jiang, Qingguang; Szabo, Alison; Herrup, Karl; Lamb, Bruce T.; Landreth, Gary E.

    2010-01-01

    Considerable evidence points to important roles for inflammation in Alzheimer’s disease (AD) pathophysiology. Epidemiological studies have suggested that long-term NSAID therapy reduces the risk for AD; however, the mechanism remains unknown. We report that a 9 month treated of aged R1.40 mice resulted in 90% decrease in plaque burden and a similar reduction in microglial activation. Ibuprofen treatment reduced levels of lipid peroxidation, tyrosine nitration, and protein oxidation, demonstrating a dramatic effect on oxidative damage in vivo. Fibrillar Aβ stimulation has previously been demonstrated to induce the assembly and activation of the microglial NADPH oxidase leading to superoxide production through a tyrosine kinase-based signaling cascade. Ibuprofen treatment of microglia or monocytes with racemic or S-ibuprofen inhibited Aβ-stimulated Vav tyrosine phosphorylation, NADPH oxidase assembly and superoxide production. Interestingly, Aβ-stimulated Vav phosphorylation was not inhibited by COX inhibitors. These findings suggest that ibuprofen acts independently of COX inhibition to disrupt signaling cascades leading to microglial NOX2 activation, preventing oxidative damage and enhancing plaque clearance in the brain. PMID:20696495

  19. Effect of tannic acid, resveratrol and its derivatives, on oxidative damage and apoptosis in human neutrophils.

    PubMed

    Zielińska-Przyjemska, Małgorzata; Ignatowicz, Ewa; Krajka-Kuźniak, Violetta; Baer-Dubowska, Wanda

    2015-10-01

    In this study we compared the antioxidant and DNA protective activity of tannic acid and stilbene derivatives, resveratrol, 3,5,4(')-trimethoxystilbene (TMS) and pterostilbene in human neutrophils stimulated to oxidative burst by 12-O-tetradecanoyl-phorbol-13-acetate (TPA) in relation to apoptosis induction. All polyphenols within the concentration range 1-100 μM reduced the intracellular ROS and H2O2 production in the TPA-stimulated cells. Tannic acid was the most effective polyphenol in protection against DNA damage induced by TPA. In the resting neutrophils resveratrol and to lesser extent other polyphenols increased DNA damage and increased the level of p53. Pretreatment of the TPA-stimulated cells with tannic acid or stilbenes led to the induction of apoptosis. The most significant effect was observed as a result of treatment with TMS and resveratrol. These compounds appeared the most effective inducers of p53 in the TPA-challenged neutrophils, what may suggest that pro-apoptotic activity of these stilbenes might be related to p53 activation. Overall, the results of our present study demonstrate that tannic acid and stilbenes modulate the ROS production, ultimately leading to cell apoptosis in human neutrophils stimulated to oxidative burst. In resting neutrophils they exhibit pro-oxidant activity, which is accompanied by p53 induction.

  20. Production-scale Direct Oxide Reduction demonstration

    SciTech Connect

    Humiston, T.J.; Santi, D.J.; Long, J.L.; Thomas, R.L.; Delaney, I.C.

    1989-01-23

    A detailed, statistically valid, examination of the direct oxide reduction parameters affecting process yield and purity was planned and executed. Guidelines for attaining yields approaching 100% are presented. Feed oxide, percent excess calcium, and stirrer design affected yield and product purity. Experiments were performed in production-scale equipment utilizing 800 grams of plutonium dioxide per charge. 1 ref., 9 figs., 3 tabs.

  1. Stem bark and flower extracts of Vismia cauliflora are highly effective antioxidants to human blood cells by preventing oxidative burst in neutrophils and oxidative damage in erythrocytes.

    PubMed

    Ribeiro, Alessandra Braga; Berto, Alessandra; Ribeiro, Daniela; Freitas, Marisa; Chisté, Renan Campos; Visentainer, Jesuí Vergílio; Fernandes, Eduarda

    2015-01-01

    Vismia cauliflora A.C.Sm. [Hypericaceae (Clusiaceae)] is an Amazonian plant traditionally used by indigenous population to treat dermatosis and inflammatory processes of the skin. Previous research on V. cauliflora extracts suggests its potential to neutralize cellular oxidative damages related to the production of reactive oxygen and nitrogen species. To determine the activity of stem bark and flower extracts of V. cauliflora on the modulation of oxidative burst in human neutrophils, as well as its potential to inhibit oxidative damage in human erythrocytes. The modulation of neutrophil's oxidative burst by the ethanolic extracts (0.3-1000 µg/mL) was determined by the oxidation of specific probes by reactive species. Additionally, the potential of these extracts to inhibit oxidative damage in human erythrocytes was evaluated by monitoring its biomarkers of oxidative stress. Vismia cauliflora extracts presented remarkable capacity to prevent the oxidative burst in activated human neutrophils (IC50 < 15 µg/mL). However, the maximum percentage of inhibition achieved against hydrogen peroxide was 45%. Concerning the oxidative damage in human erythrocytes, the extracts were able to minimize the tert-butyl hydroperoxide-induced hemoglobin oxidation and lipid peroxidation in a very low concentration range (2.7-18 μg/mL). Furthermore, only stem bark extract (100 µg/mL) was able to inhibit the depletion of glutathione (13%). These results reinforce the therapeutic potential of stem bark and flower extracts of V. cauliflora to heal topical skin disease, namely in the treatment of neutrophil-related dermatosis and skin conditions related to oxidative stress, including skin aging.

  2. Impact-induced muscle damage and urinary pterins in professional rugby: 7,8-dihydroneopterin oxidation by myoglobin.

    PubMed

    Lindsay, A; Healy, J; Mills, W; Lewis, J; Gill, N; Draper, N; Gieseg, S P

    2016-03-01

    Muscle damage caused through impacts in rugby union is known to increase oxidative stress and inflammation. Pterins have been used clinically as markers of oxidative stress, inflammation, and neurotransmitter synthesis. This study investigates the release of myoglobin from muscle tissue due to force-related impacts and how it is related to the subsequent oxidation of 7,8-dihydroneopterin to specific pterins. Effects of iron and myoglobin on 7,8-dihydroneopterin oxidation were examined in vitro via strong cation-exchange high-performance liquid chromatography (SCX-HPLC) analysis of neopterin, xanthopterin, and 7,8-dihydroxanthopterin. Urine samples were collected from 25 professional rugby players pre and post four games and analyzed for myoglobin by enzyme-linked immunosorbent assay, and 7,8-dihydroneopterin oxidation products by HPLC. Iron and myoglobin oxidized 7,8-dihydroneopterin to neopterin, xanthopterin, and 7,8-dihydroxanthopterin at concentrations at or above 10 μM and 50 μg/mL, respectively. All four games showed significant increases in myoglobin, neopterin, total neopterin, biopterin, and total biopterin, which correlated between each variable (P < 0.05). Myoglobin and iron facilitate 7,8-dihydroneopterin oxidation to neopterin and xanthopterin. In vivo delocalization of myoglobin due to muscle damage may contribute to oxidative stress and inflammation after rugby. Increased concentrations of biopterin and total biopterin may indicate production of nitric oxide and monoamine neurotransmitters in response to the physical stress.

  3. Comparison of Oxidative Stress/DNA Damage in Semen and Blood of Fertile and Infertile Men

    PubMed Central

    Guz, Jolanta; Gackowski, Daniel; Foksinski, Marek; Rozalski, Rafal; Zarakowska, Ewelina; Siomek, Agnieszka; Szpila, Anna; Kotzbach, Marcin; Kotzbach, Roman; Olinski, Ryszard

    2013-01-01

    Abnormal spermatozoa frequently display typical features of oxidative stress, i.e. excessive level of reactive oxygen species (ROS) and depleted antioxidant capacity. Moreover, it has been found that a high level of oxidatively damaged DNA is associated with abnormal spermatozoa and male infertility. Therefore, the aim of our study was the comparison of oxidative stress/DNA damage in semen and blood of fertile and infertile men. The broad range of parameters which describe oxidative stress and oxidatively damaged DNA and repair were analyzed in the blood plasma and seminal plasma of groups of fertile and infertile subjects. These parameters include: (i) 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydroguanine (8-oxoGua) levels in urine; (ii) 8-oxodG level in DNA isolated from leukocytes and spermatozoa; (iii) antioxidant vitamins (A, C and E) and uric acid. Urinary excretion of 8-oxodG and 8-oxoGua and the level of oxidatively damaged DNA in leukocytes as well as the level of antioxidant vitamins were analyzed using HPLC and HPLC/GC/MS methods. The results of our study demonstrate that 8-oxodG level significantly correlated with every parameter which describe sperm quality: sperm count, motility and morphology. Moreover, the data indicate a higher level of 8-oxodG in sperm DNA compared with DNA of surrogate tissue (leukocytes) in infertile men as well as in healthy control group. For the whole study population the median values of 8-oxodG/106 dG were respectively 7.85 and 5.87 (p = 0.000000002). Since 8-oxodG level in sperm DNA is inversely correlated with urinary excretion rate of 8-oxoGua, which is the product of OGG1 activity, we hypothesize that integrity of spermatozoa DNA may be highly dependent on OGG1 activity. No relationship between the whole body oxidative stress and that of sperm plasma was found, which suggests that the redox status of semen may be rather independent on this characteristic for other tissues. PMID:23874641

  4. Aging-associated oxidized albumin promotes cellular senescence and endothelial damage.

    PubMed

    Luna, Carlos; Alique, Matilde; Navalmoral, Estefanía; Noci, Maria-Victoria; Bohorquez-Magro, Lourdes; Carracedo, Julia; Ramírez, Rafael

    2016-01-01

    Increased levels of oxidized proteins with aging have been considered a cardiovascular risk factor. However, it is unclear whether oxidized albumin, which is the most abundant serum protein, induces endothelial damage. The results of this study indicated that with aging processes, the levels of oxidized proteins as well as endothelial microparticles release increased, a novel marker of endothelial damage. Among these, oxidized albumin seems to play a principal role. Through in vitro studies, endothelial cells cultured with oxidized albumin exhibited an increment of endothelial damage markers such as adhesion molecules and apoptosis levels. In addition, albumin oxidation increased the amount of endothelial microparticles that were released. Moreover, endothelial cells with increased oxidative stress undergo senescence. In addition, endothelial cells cultured with oxidized albumin shown a reduction in endothelial cell migration measured by wound healing. As a result, we provide the first evidence that oxidized albumin induces endothelial injury which then contributes to the increase of cardiovascular disease in the elderly subjects.

  5. Aging-associated oxidized albumin promotes cellular senescence and endothelial damage

    PubMed Central

    Luna, Carlos; Alique, Matilde; Navalmoral, Estefanía; Noci, Maria-Victoria; Bohorquez-Magro, Lourdes; Carracedo, Julia; Ramírez, Rafael

    2016-01-01

    Increased levels of oxidized proteins with aging have been considered a cardiovascular risk factor. However, it is unclear whether oxidized albumin, which is the most abundant serum protein, induces endothelial damage. The results of this study indicated that with aging processes, the levels of oxidized proteins as well as endothelial microparticles release increased, a novel marker of endothelial damage. Among these, oxidized albumin seems to play a principal role. Through in vitro studies, endothelial cells cultured with oxidized albumin exhibited an increment of endothelial damage markers such as adhesion molecules and apoptosis levels. In addition, albumin oxidation increased the amount of endothelial microparticles that were released. Moreover, endothelial cells with increased oxidative stress undergo senescence. In addition, endothelial cells cultured with oxidized albumin shown a reduction in endothelial cell migration measured by wound healing. As a result, we provide the first evidence that oxidized albumin induces endothelial injury which then contributes to the increase of cardiovascular disease in the elderly subjects. PMID:27042026

  6. Oxidative Damage of Biomolecules by the Environmental Pollutants NO2(•) and NO3(•).

    PubMed

    Gamon, Luke F; Wille, Uta

    2016-10-18

    Air pollution is responsible for the premature death of about 7 million people every year. Ozone (O3) and nitrogen dioxide (NO2(•)) are the key gaseous pollutants in the troposphere, which predominantly result from combustion processes. Their inhalation leads to reactions with constituents in the airway surface fluids (ASF) of the respiratory tract and/or lungs. ASF contain small molecular-weight antioxidants, which protect the underlying epithelial cells against oxidative damage. When this defense system is overwhelmed, proteins and lipids present on cell surfaces or within the ASF become vulnerable to attack. The resulting highly reactive protein and lipid oxidation products could subsequently damage the epithelial cells through secondary reactions, thereby causing inflammation. While reactions of NO2(•) with biological molecules are considered to proceed through radical pathways, the biological effect of O3 is attributed to its high reactivity with π systems. Because O3 and NO2(•) always coexist in the polluted ambient atmosphere, synergistic effects resulting from in situ formed strongly oxidizing nitrate radicals (NO3(•)) may also require consideration. For example, in vitro product studies revealed that phenylalanine, which is inert not only to oxidants produced through biochemical processes, but also to NO2(•) or O3 in isolation, is damaged by NO3(•). The reaction is initiated by oxidation of the aromatic ring and, depending on the availability of NO2(•), leads to formation of nitrophenylalanine or β-nitrooxyphenylalanine, which could serve as marker for NO3(•)-induced oxidative damage in peptides. More easily oxidizable aromatic amino acids are directly attacked by NO2(•) and are converted to the same products independent of whether O3 is also present. Remarkably, NO2(•)-induced oxidative damage in peptides occurs not only through the well-established radical oxidation of peptide side chains, but also through an unprecedented

  7. In vitro effects of 50 Hz magnetic fields on oxidatively damaged rabbit red blood cells

    SciTech Connect

    Fiorani, M.; Biagiarelli, B.; Vetrano, F.; Guidi, G.; Dacha, M.; Stocchi, V.

    1997-05-01

    The aim of this study was to investigate the effects of 50 Hz magnetic fields on rabbit red blood cells (RBCs) that were exposed simultaneously to the action of an oxygen radical-generating system, Fe(II)/ascorbate. Previous data obtained in the authors` laboratory showed that the exposure of rabbit erythrocytes or reticulocytes to Fe(II)/ascorbate induces hexokinase inactivation, whereas the other glycolytic enzymes do not show any decay. The authors also observed depletion of reduced glutathione (GSH) content with a concomitant intracellular and extracellular increase in oxidized glutathione (GSSG) and a decrease in energy charge. In this work, they investigated whether 50 Hz magnetic fields could influence the intracellular impairments that occur when erythrocytes or reticulocytes are exposed to this oxidant system, namely, inactivation of hexokinase activity, GSH depletion, a change in energy charge, and hemoglobin oxidation. The results obtained indicate that a 0.5 mT magnetic field had no effect on intact RBCs, whereas it increased the damage in an oxidatively stressed erythrocyte system. In fact, exposure of intact erythrocytes incubated with Fe(II)/ascorbate to a 0.5 mT magnetic field induced a significant further decay in hexokinase activity as well as a twofold increase in methemoglobin production compared with RBCs that were exposed to the oxidant system alone. Although further studies will be needed to determine the physiological implications of these data, the results reported in this study demonstrate that the effects of the magnetic fields investigated are able to potentiate the cellular damage induced in vitro by oxidizing agents.

  8. Oxidative Stress and Proinflammatory Cytokines Contribute to Demyelination and Axonal Damage in a Cerebellar Culture Model of Neuroinflammation

    PubMed Central

    di Penta, Alessandra; Moreno, Beatriz; Reix, Stephanie; Fernandez-Diez, Begoña; Villanueva, Maite; Errea, Oihana; Escala, Nagore; Vandenbroeck, Koen; Comella, Joan X.; Villoslada, Pablo

    2013-01-01

    Background Demyelination and axonal damage are critical processes in the pathogenesis of multiple sclerosis (MS). Oxidative stress and pro-inflammatory cytokines elicited by inflammation mediates tissue damage. Methods/Principal Findings To monitor the demyelination and axonal injury associated with microglia activation we employed a model using cerebellar organotypic cultures stimulated with lipopolysaccharide (LPS). Microglia activated by LPS released pro-inflammatory cytokines (IL-1β, IL-6 and TNFα), and increased the expression of inducible nitric oxide synthase (iNOS) and production of reactive oxygen species (ROS). This activation was associated with demyelination and axonal damage in cerebellar cultures. Axonal damage, as revealed by the presence of non-phosphorylated neurofilaments, mitochondrial accumulation in axonal spheroids, and axonal transection, was associated with stronger iNOS expression and concomitant increases in ROS. Moreover, we analyzed the contribution of pro-inflammatory cytokines and oxidative stress in demyelination and axonal degeneration using the iNOS inhibitor ethyl pyruvate, a free-scavenger and xanthine oxidase inhibitor allopurinol, as well as via blockage of pro-inflammatory cytokines using a Fc-TNFR1 construct. We found that blocking microglia activation with ethyl pyruvate or allopurinol significantly decreased axonal damage, and to a lesser extent, demyelination. Blocking TNFα significantly decreased demyelination but did not prevented axonal damage. Moreover, the most common therapy for MS, interferon-beta, was used as an example of an immunomodulator compound that can be tested in this model. In vitro, interferon-beta treatment decreased oxidative stress (iNOS and ROS levels) and the release of pro-inflammatory cytokines after LPS stimulation, reducing axonal damage. Conclusion The model of neuroinflammation using cerebellar culture stimulated with endotoxin mimicked myelin and axonal damage mediated by the combination of

  9. Metformin does not prevent DNA damage in lymphocytes despite its antioxidant properties against cumene hydroperoxide-induced oxidative stress.

    PubMed

    Onaran, Ilhan; Guven, Gulgun S; Ozdaş, Sule Beyhan; Kanigur, Gonul; Vehid, Suphi

    2006-12-10

    Metformin (1-(diaminomethylidene)-3,3-dimethyl-guanidine), which is the most commonly prescribed oral antihyperglycaemic drug in the world, was reported to have several antioxidant properties such as the inhibition of advanced glycation end-products. In addition to its use in the treatment of diabetes, it has been suggested that metformin may be a promising anti-aging agent. The present work was aimed at assessing the possible protective effects of metformin against DNA-damage induction by oxidative stress in vitro. The effects of metformin were compared with those of N-acetylcysteine (NAC). For this purpose, peripheral blood lymphocytes from aged (n=10) and young (n=10) individuals were pre-incubated with various concentrations of metformin (10-50microM), followed by incubation with 15microM cumene hydroperoxide (CumOOH) for 48h, under conditions of low oxidant level, which do not induce cell death. Protection against oxidative DNA damage was evaluated by use of the Comet assay and the cytokinesis-block micronucleus technique. Changes in the levels of malondialdehyde+4-hydroxy-alkenals, an index of oxidative stress, were also measured in lymphocytes. At concentrations ranging from 10microM to 50microM, metformin did not protect the lymphocytes from DNA damage, while 50microM NAC possessed an effective protective effect against CumOOH-induced DNA damage. Furthermore, NAC, but not metformin, inhibited DNA fragmentation induced by CumOOH. In contrast to the lack of protection against oxidative damage in lymphocyte cultures, metformin significantly protected the cells from lipid peroxidation in both age groups, although not as effective as NAC in preventing the peroxidative damage at the highest doses. Within the limitations of this study, the results indicate that pharmacological concentrations of metformin are unable to protect against DNA damage induced by a pro-oxidant stimulus in cultured human lymphocytes, despite its antioxidant properties.

  10. Oxidative DNA damage caused by pulsed discharge with cavitation on the bactericidal function

    NASA Astrophysics Data System (ADS)

    Kudo, Ken-ichi; Ito, Hironori; Ihara, Satoshi; Terato, Hiroaki

    2015-09-01

    Plasma-based techniques are expected to have practical use for wastewater purification with a potential for killing contaminated microorganisms and degrading recalcitrant materials. In the present study, we analysed oxidative DNA damage in bacterial cells treated by the plasma to unveil its mechanisms in the bactericidal process. Escherichia coli cell suspension was exposed to the plasma induced by applying an alternating-current voltage of about 1 kV with bubbling formed by water-cavitation, termed pulsed discharge with cavitation. Chromosomal DNA damage, such as double strand break (DSB) and oxidative base lesions, increased proportionally with the applied energy, as determined by electrophoretic and mass spectrometric analyses. Among the base lesions identified, the yields of 8-hydroxyguanine (8-OH-G) and 5-hydroxycytosine (5-OH-C) in chromosomal DNA increased by up to 4- and 15-fold, respectively, compared to untreated samples. The progeny DNA sequences, derived from plasmid DNA exposed to the plasma, indicated that the production rate of 5-OH-C exceeded that of 8-OH-G, as G:C to A:T transitions accounted for 65% of all base changes, but only a few G:C to T:A transversions were observed. The cell viabilities of E. coli cells decreased in direct proportion to increases in the applied energy. Therefore, the plasma-induced bactericidal mechanism appears to relate to oxidative damage caused to bacterial DNA. These results were confirmed by observing the generation of hydroxyl radicals and hydrogen peroxide molecules following the plasma exposure. We also compared our results with the plasma to those obtained with 137Cs γ-rays, as a well-known ROS generator to confirm the DNA-damaging mechanism involved.

  11. Detection of DNA damage by using hairpin molecular beacon probes and graphene oxide.

    PubMed

    Zhou, Jie; Lu, Qian; Tong, Ying; Wei, Wei; Liu, Songqin

    2012-09-15

    A hairpin molecular beacon tagged with carboxyfluorescein in combination with graphene oxide as a quencher reagent was used to detect the DNA damage by chemical reagents. The fluorescence of molecular beacon was quenched sharply by graphene oxide; while in the presence of its complementary DNA the quenching efficiency decreased because their hybridization prevented the strong adsorbability of molecular beacon on graphene oxide. If the complementary DNA was damaged by a chemical reagent and could not form intact duplex structure with molecular beacon, more molecular beacon would adsorb on graphene oxide increasing the quenching efficiency. Thus, damaged DNA could be detected based on different quenching efficiencies afforded by damaged and intact complementary DNA. The damage effects of chlorpyrifos-methyl and three metabolites of styrene such as mandelieaeids, phenylglyoxylieaeids and epoxystyrene on DNA were studied as models. The method for detection of DNA damage was reliable, rapid and simple compared to the biological methods. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. A study of pyrimidine base damage in relation to oxidative stress and cancer

    PubMed Central

    Iijima, H; Patrzyc, H B; Budzinski, E E; Freund, H G; Dawidzik, J B; Rodabaugh, K J; Box, H C

    2009-01-01

    Background: A long-standing hypothesis is that oxidative stress is a risk factor for cancer. Support for this hypothesis comes from observations of higher levels of oxidative damage in the DNA of WBC of cancer patients compared with healthy controls. Methods: Two generally overlooked types of DNA damage, the formamide modification and the thymine glycol modification, both derived from pyrimidine bases, were assayed as markers of oxidative stress. Damage levels were measured in the DNA of WBC of ovarian cancer patients and of healthy controls. Results: The levels of both modifications were higher in ovarian cancer patients than in healthy controls although in the case of the formamide modification age could not be ruled out as a factor. Conclusion: Our results in combination with other published measurements of oxidative DNA damage support the hypothesis that oxidative damage, on average, is higher in WBC of cancer patients than in healthy controls. PMID:19603029

  13. Non-thermal dielectric-barrier discharge plasma damages human keratinocytes by inducing oxidative stress

    PubMed Central

    KIM, KI CHEON; PIAO, MEI JING; HEWAGE, SUSARA RUWAN KUMARA MADDUMA; HAN, XIA; KANG, KYOUNG AH; JO, JIN OH; MOK, YOUNG SUN; SHIN, JENNIFER H.; PARK, YEUNSOO; YOO, SUK JAE; HYUN, JIN WON

    2016-01-01

    The aim of this study was to identify the mechanisms through which dielectric-barrier discharge plasma damages human keratinocytes (HaCaT cells) through the induction of oxidative stress. For this purpose, the cells were exposed to surface dielectric-barrier discharge plasma in 70% oxygen and 30% argon. We noted that cell viability was decreased following exposure of the cells to plasma in a time-dependent manner, as shown by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The levels of intracellular reactive oxygen species (ROS) were determined using 2′,7′-dichlorodihydro-fluorescein diacetate and dihydroethidium was used to monitor superoxide anion production. Plasma induced the generation of ROS, including superoxide anions, hydrogen peroxide and hydroxyl radicals. N-acetyl cysteine, which is an antioxidant, prevented the decrease in cell viability caused by exposure to plasma. ROS generated by exposure to plasma resulted in damage to various cellular components, including lipid membrane peroxidation, DNA breaks and protein carbonylation, which was detected by measuring the levels of 8-isoprostane and diphenyl-1-pyrenylphosphine assay, comet assay and protein carbonyl formation. These results suggest that plasma exerts cytotoxic effects by causing oxidative stress-induced damage to cellular components. PMID:26573561

  14. Non-thermal dielectric-barrier discharge plasma damages human keratinocytes by inducing oxidative stress.

    PubMed

    Kim, Ki Cheon; Piao, Mei Jing; Madduma Hewage, Susara Ruwan Kumara; Han, Xia; Kang, Kyoung Ah; Jo, Jin Oh; Mok, Young Sun; Shin, Jennifer H; Park, Yeunsoo; Yoo, Suk Jae; Hyun, Jin Won

    2016-01-01

    The aim of this study was to identify the mechanisms through which dielectric-barrier discharge plasma damages human keratinocytes (HaCaT cells) through the induction of oxidative stress. For this purpose, the cells were exposed to surface dielectric-barrier discharge plasma in 70% oxygen and 30% argon. We noted that cell viability was decreased following exposure of the cells to plasma in a time-dependent manner, as shown by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The levels of intracellular reactive oxygen species (ROS) were determined using 2',7'-dichlorodihydrofluorescein diacetate and dihydroethidium was used to monitor superoxide anion production. Plasma induced the generation of ROS, including superoxide anions, hydrogen peroxide and hydroxyl radicals. N-acetyl cysteine, which is an antioxidant, prevented the decrease in cell viability caused by exposure to plasma. ROS generated by exposure to plasma resulted in damage to various cellular components, including lipid membrane peroxidation, DNA breaks and protein carbonylation, which was detected by measuring the levels of 8-isoprostane and diphenyl-1-pyrenylphosphine assay, comet assay and protein carbonyl formation. These results suggest that plasma exerts cytotoxic effects by causing oxidative stress-induced damage to cellular components.

  15. Significant damage-rescuing effects of wood vinegar extract in living Caenorhabditis elegans under oxidative stress.

    PubMed

    Cai, Kezhou; Jiang, Shaotong; Ren, Chong; He, Yujie

    2012-01-15

    Wood vinegar (WV), a byproduct from the charcoal production process, has been reported to have excellent antioxidant capability by chemical examination. However, the biological effect of WV in living animals is still unknown. In this study, a simple model organism, the nematode Caenorhabditis elegans, was used as an in vivo system to assess the biological effects of wood vinegar through the development, lifespan, brood size, germline cell apoptosis and superoxide dismutase (SOD) level. Wood vinegar extract (WVE) promoted the development, prolonged the lifespan and increased the brood size in reactive oxidative species (ROS)-sensitive mutant worms. WVE treatment rescued the effects of damage in germline cell apoptosis and SOD upregulation induced by paraquat, an ROS generator, to the control level. Additionally, WVE showed comparative ability in rescuing damage as compared with L-ascorbic acid and α-tocopherol. WVE treatment exhibits a remedial/beneficial effect on ROS-sensitive mutant under normal cultural conditions and on wild-type worms under oxidative stress. ROS scavenging is involved in the damage-rescuing mechanism. This study will provide a basal biological and nutritional exploration for the use of WV as a functional food, and for the substitution of chemical antioxidants with side effects in food. Copyright © 2011 Society of Chemical Industry.

  16. Dimethoate-induced oxidative stress and DNA damage in Oncorhynchus mykiss.

    PubMed

    Dogan, Demet; Can, Canan; Kocyigit, Abdurrahim; Dikilitas, Murat; Taskin, Abdullah; Bilinc, Hasan

    2011-06-01

    The present study was conducted in order to investigate pro-oxidant activity of dimethoate in liver and brain tissues following sublethal pesticide exposure for 5, 15 and 30 d by using SOD, GPx, CAT enzyme activities and lipid peroxidation as biomarkers as well as DNA damaging potential via detecting% Tail DNA, Tail moment and Olive tail moment as endpoints in erythrocytes of Oncorhynchus mykiss in an in vitro experiment. Antioxidant enzyme activities were found to elicit two staged response which was an initial induction followed by a sharp inhibition in liver tissue while a sustained increase in GPx activity and slight stimulation in SOD activity were detected in brain tissue. Lipid peroxidation showed an ascending pattern throughout the exposure period in both tissues and a decreasing trend was determined in tissue protein levels which was proved to be positively correlated with duration. Similar findings were obtained from outcomes preferred to quantify DNA damage and TM was decided to reflect the extent of damage more sensitively because of determined positive correlation with concentrations applied. Considering these results, it can be concluded that oxidative stress condition evoked by dimethoate could not be responded effectively and genotoxic nature of pesticide was proven by determined clastogenic effect possibly via being an alkylation agent or stimulating the production of reactive species.

  17. Helicobacter pylori and Its Virulence Factors' Effect on Serum Oxidative DNA Damages in Adults With Dyspepsia.

    PubMed

    Shahi, Heshmat; Bahreiny, Rasoul; Reiisi, Somayeh

    2016-11-01

    Helicobacter Pylori infection is a common gastrointestinal infection that can cause pathological effects, increase oxidative stress and induce an inflammatory response in gastric mucosa. Inflammatory aspects may prompt the production of radical oxygen substance (ROS) which may damage cells and release 8-hydroxydyoxyguanosine (8-OHdG) to serum. In this study, we evaluate the prevalence of H. pylori virulence factors and the association between serum level of 8-OHdG, H. pylori infection, and its various virulence factors. The presence of H. pylori and prevalence of cagA, babA and oipA genes in samples were determined by rapid urease test (RUT), histopathological exam (HE) and polymerase chain reaction (PCR) and oxidative DNA damage situation were assessed by using serum level of 8-OHdG. There was not any direct relation between H. pylori negative and H. pylori oipA+specimens by 8-OHdG serum level (P>0.05). In all clinical observations, the presence of cagA and oipA genes was common. There was a statistical relationship between the presence of cagA, babA factors, and high serum level of 8-OHdG (P<0.05). The presence of cagA and babA virulence factors may be associated with increased serum 8-OHdG in dyspeptic patients and may induce the damage to gastric cells.

  18. Enantioselective oxidative damage of chiral pesticide dichlorprop to maize.

    PubMed

    Wu, Tong; Li, Xiuying; Huang, Honglin; Zhang, Shuzhen

    2011-04-27

    To investigate the enantioselective oxidative damage of the pesticide dichlorprop (DCPP) to maize, young seedlings were exposed to solutions of DCPP enantiomers and racemate at different concentrations. Early root development was more influenced by (R)-DCPP than racemic (rac)- and (S)-DCPP. Inhibition rates of seed germination, seedling biomass, and root and shoot elongation were all in the order of (R)-DCPP > (rac)-DCPP > (S)-DCPP treatments. The antioxidant enzyme activities of superoxide dismutase (SOD) and peroxidase (POD) were significantly upregulated by exposure to lower concentrations of (R)-DCPP than (rac)- and (S)-DCPP. Direct determination of the formation of hydroxyl radical (•OH) with electron paramagnetic resonance (EPR) spectroscopy indicated that the •OH level in maize roots followed the order of (R)-DCPP > (rac)-DCPP > (S)-DCPP treatments. All of these results provide solicited evidence of the significant enantioselective phytotoxicity of DCPP to maize with a higher toxicity of (R)-DCPP than (S)- and (rac)-DCPP.

  19. An Update on Oxidative Damage to Spermatozoa and Oocytes

    PubMed Central

    Opuwari, Chinyerum S.; Henkel, Ralf R.

    2016-01-01

    On the one hand, reactive oxygen species (ROS) are mandatory mediators for essential cellular functions including the function of germ cells (oocytes and spermatozoa) and thereby the fertilization process. However, the exposure of these cells to excessive levels of oxidative stress by too high levels of ROS or too low levels of antioxidative protection will render these cells dysfunctional thereby failing the fertilization process and causing couples to be infertile. Numerous causes are responsible for the delicate bodily redox system being out of balance and causing disease and infertility. Many of these causes are modifiable such as lifestyle factors like obesity, poor nutrition, heat stress, smoking, or alcohol abuse. Possible correctable measures include foremost lifestyle changes, but also supplementation with antioxidants to scavenge excessive ROS. However, this should only be done after careful examination of the patient and establishment of the individual bodily antioxidant needs. In addition, other corrective measures include sperm separation for assisted reproductive techniques. However, these techniques have to be carried out very carefully as they, if applied wrongly, bear risks of generating ROS damaging the germ cells and preventing fertilization. PMID:26942204

  20. Biological oxidative damage by carbon nanotubes: fingerprint or footprint?

    PubMed

    Hsieh, Shu-Feng; Bello, Dhimiter; Schmidt, Daniel F; Pal, Anoop K; Rogers, Eugene J

    2012-02-01

    Carbon nanotubes (CNTs) have received much attention for performance and toxicity, but vary substantially in terms of impurity type and content, morphology, and surface activity. This study determined the decrease of antioxidant capacity, defined as biological oxidative damage (BOD), of CNTs-exposed serum. The variability in several physicochemical properties of CNTs and their links to BOD elicited in human serum were explored. Tremendous variation in transition metal type and content (104-fold), specific surface area (SSA, nine-fold), and BOD were observed. Mass specific BOD (mBOD) varied from 0.006-0.187 μmol TEU mg(-1), whereas surface area specific BOD (sBOD) varied from 0.068-0.42 μmol TEU m(-2). The sBOD increased in a stepwise fashion from ∼0.1-0.32 μmol TEU m(-2) for tubes with outer diameter less than 10 nm. The mBOD and sBOD may be useful denominators of surface activity and impurity content and assist in designing safer CNTs.

  1. Nitroxide stable radicals protect beating cardiomyocytes against oxidative damage

    SciTech Connect

    Samuni, A.; Winkelsberg, D.; Pinson, A.; Hahn, S.M.; Mitchell, J.B.; Russo, A. )

    1991-05-01

    The protective effect of stable nitroxide radicals against oxidative damage was studied using cardiomyocyte cultures obtained from newborn rats. Monolayered cardiomyocytes were exposed to H{sub 2}O{sub 2} and the effect on spontaneous beating and leakage of LDH was determined. Hydrogen peroxide irreversibly blocked rhythmic beating and resulted in a significant membrane injury as shown by release of LDH. The injury was prevented by catalase which removes H{sub 2}O{sub 2} and by cell-permeable, metal-chelating agents such as desferrioxamine or bipyridine. In contrast, reagents which are excluded from the cell such as superoxide dismutase or DTPA did not protect the cells against H{sub 2}O{sub 2}. Five- and six-membered ring, stable nitroxide radicals which have previously been shown to chemically act as low-molecular weight, membrane-permeable, SOD-mimetic compounds provided full protection. The nitroxides prevented leakage of LDH and preserved normal cardiomyocyte contractility, presumably by intercepting intracellular O{sub 2}-radicals. Alternatively, protection may result through nitroxides reacting with reduced transition metal ions or by detoxifying secondary organic radicals.

  2. Transgenic Mouse Model for Reducing Oxidative Damage in Bone

    NASA Technical Reports Server (NTRS)

    Schreurs, A.-S.; Torres, S.; Truong, T.; Kumar, A.; Alwood, J. S.; Limoli, C. L.; Globus, R. K.

    2014-01-01

    Exposure to musculoskeletal disuse and radiation result in bone loss; we hypothesized that these catabolic treatments cause excess reactive oxygen species (ROS), and thereby alter the tight balance between bone resorption by osteoclasts and bone formation by osteoblasts, culminating in bone loss. To test this, we used transgenic mice which over-express the human gene for catalase, targeted to mitochondria (MCAT). Catalase is an anti-oxidant that converts the ROS hydrogen peroxide into water and oxygen. MCAT mice were shown previously to display reduced mitochondrial oxidative stress and radiosensitivity of the CNS compared to wild type controls (WT). As expected, MCAT mice expressed the transgene in skeletal tissue, and in marrow-derived osteoblasts and osteoclast precursors cultured ex vivo, and also showed greater catalase activity compared to wildtype (WT) mice (3-6 fold). Colony expansion in marrow cells cultured under osteoblastogenic conditions was 2-fold greater in the MCAT mice compared to WT mice, while the extent of mineralization was unaffected. MCAT mice had slightly longer tibiae than WT mice (2%, P less than 0.01), although cortical bone area was slightly lower in MCAT mice than WT mice (10%, p=0.09). To challenge the skeletal system, mice were treated by exposure to combined disuse (2 wk Hindlimb Unloading) and total body irradiation Cs(137) (2 Gy, 0.8 Gy/min), then bone parameters were analyzed by 2-factor ANOVA to detect possible interaction effects. Treatment caused a 2-fold increase (p=0.015) in malondialdehyde levels of bone tissue (ELISA) in WT mice, but had no effect in MCAT mice. These findings indicate that the transgene conferred protection from oxidative damage caused by treatment. Unexpected differences between WT and MCAT mice emerged in skeletal responses to treatment.. In WT mice, treatment did not alter osteoblastogenesis, cortical bone area, moment of inertia, or bone perimeter, whereas in MCAT mice, treatment increased these

  3. Nitric oxide alleviates oxidative damage induced by high temperature stress in wheat.

    PubMed

    Bavita, A; Shashi, B; Navtej, S B

    2012-05-01

    Effect of sodium nitroprusside (SNP), a donor of nitric oxide (NO) was examined in two wheat (Triticum aestivum L.) cultivars, C 306 (heat tolerant) and PBW 550 (comparatively heat susceptible) to study the extent of oxidative injury and activities of antioxidant enzyme in relation to high temperature (HT) stress. HT stress resulted in a marked decrease in membrane thermostability (MTS) and 2, 3, 5-triphenyl tetrazolium chloride (TTC) cell viability whereas content of lipid peroxide increased in both the cultivars. The tolerant cultivar C 306 registered less damage to cellular membranes compared to PBW 550 under HT stress. Activities of antioxidant enzymes viz, superoxide dismutase, catalase, ascorbate peroxidase, guaicol peroxidase and glutathione reductase increased with HT in both the cultivars. Following treatment with SNP, activities of all antioxidant enzymes further increased in correspondence with an increase in MTS and TTC. Apparently, lipid peroxide content was reduced by SNP more in shoots of heat tolerant cultivar C 306 indicating better protection over roots under HT stress. The up-regulation of the antioxidant system by NO possibly contributed to better tolerance against HT induced oxidative damage in wheat.

  4. Caryocar brasiliense camb protects against genomic and oxidative damage in urethane-induced lung carcinogenesis

    PubMed Central

    Colombo, N.B.R.; Rangel, M.P.; Martins, V.; Hage, M.; Gelain, D.P.; Barbeiro, D.F.; Grisolia, C.K.; Parra, E.R.; Capelozzi, V.L.

    2015-01-01

    The antioxidant effects of Caryocar brasiliense Camb, commonly known as the pequi fruit, have not been evaluated to determine their protective effects against oxidative damage in lung carcinogenesis. In the present study, we evaluated the role of pequi fruit against urethane-induced DNA damage and oxidative stress in forty 8-12 week old male BALB/C mice. An in vivo comet assay was performed to assess DNA damage in lung tissues and changes in lipid peroxidation and redox cycle antioxidants were monitored for oxidative stress. Prior supplementation with pequi oil or its extract (15 µL, 60 days) significantly reduced urethane-induced oxidative stress. A protective effect against DNA damage was associated with the modulation of lipid peroxidation and low protein and gene expression of nitric oxide synthase. These findings suggest that the intake of pequi fruit might protect against in vivo genotoxicity and oxidative stress. PMID:26200231

  5. Cholesterol Oxidation in Fish and Fish Products.

    PubMed

    Dantas, Natalie Marinho; Sampaio, Geni Rodrigues; Ferreira, Fernanda Silva; Labre, Tatiana da Silva; Torres, Elizabeth Aparecida Ferraz da Silva; Saldanha, Tatiana

    2015-12-01

    Fish and fish products are important from a nutritional point of view due to the presence of high biological value proteins and the high content of polyunsaturated fatty acids, especially those of the n-3 series, and above all eicosapentaenoic acid and docosahexaenoic acid. However, these important food products also contain significant amounts of cholesterol. Although cholesterol participates in essential functions in the human body, it is unstable, especially in the presence of light, oxygen, radiation, and high temperatures that can cause the formation of cholesterol oxidation products or cholesterol oxides, which are prejudicial to human health. Fish processing involves high and low temperatures, as well as other methods for microbiological control, which increases shelf life and consequently added value; however, such processes favor the formation of cholesterol oxidation products. This review brings together data on the formation of cholesterol oxides during the preparation and processing of fish into food products which are recognized and recommended for their nutritional properties.

  6. Dynamics of protein damage in yeast frataxin mutant exposed to oxidative stress.

    PubMed

    Kim, Jin-Hee; Sedlak, Miroslav; Gao, Qiang; Riley, Catherine P; Regnier, Fred E; Adamec, Jiri

    2010-12-01

    Oxidative stress and protein carbonylation is implicated in aging and various diseases such as neurodegenerative disorders, diabetes, and cancer. Therefore, the accurate identification and quantification of protein carbonylation may lead to the discovery of new biomarkers. We have developed a new method that combines avidin affinity selection of carbonylated proteins with iTRAQ labeling and LC fractionation of intact proteins. This simple LC-based workflow is an effective technique to reduce sample complexity, minimize technical variation, and enable simultaneous quantification of four samples. This method was used to determine protein oxidation in an iron accumulating mutant of Saccharomyces cerevisiae exposed to oxidative stress. Overall, 31 proteins were identified with 99% peptide confidence, and of those, 27 proteins were quantified. Most of the identified proteins were associated with energy metabolism (32.3%), and cellular defense, transport, and folding (38.7%), suggesting a drop in energy production and reducing power of the cells due to the damage of glycolytic enzymes and decrease in activity of enzymes involved in protein protection and regeneration. In addition, the oxidation sites of seven proteins were identified and their estimated position also indicated a potential impact on the enzymatic activities. Predicted 3D structures of peroxiredoxin (TSA1) and thioredoxin II (TRX2) revealed close proximity of all oxidized amino acid residues to the protein active sites.

  7. Oxidative DNA damage protective activity, antioxidant and anti-quorum sensing potentials of Moringa oleifera.

    PubMed

    Singh, Brahma N; Singh, B R; Singh, R L; Prakash, D; Dhakarey, R; Upadhyay, G; Singh, H B

    2009-06-01

    The aqueous extract of leaf (LE), fruit (FE) and seed (SE) of Moringa oleifera was assessed to examine the ability to inhibit the oxidative DNA damage, antioxidant and anti-quorum sensing (QS) potentials. It was found that these extracts could significantly inhibit the OH-dependent damage of pUC18 plasmid DNA and also inhibit synergistically with trolox, with an activity sequence of LE > FE > SE. HPLC and MS/MS analysis was carried out, which showed the presence of gallic acid, chlorogenic acid, ellagic acid, ferulic acid, kaempferol, quercetin and vanillin. The LE was with comparatively higher total phenolics content (105.04 mg gallic acid equivalents (GAE)/g), total flavonoids content (31.28 mg quercetin equivalents (QE)/g), and ascorbic acid content (106.95 mg/100 g) and showed better antioxidant activity (85.77%), anti-radical power (74.3), reducing power (1.1 ascorbic acid equivalents (ASE)/ml), inhibition of lipid peroxidation, protein oxidation, OH-induced deoxyribose degradation, and scavenging power of superoxide anion and nitric oxide radicals than did the FE, SE and standard alpha-tocopherol. Eventually, LE and FE were found to inhibit violacein production, a QS-regulated behavior in Chromobacterium violaceum 12472.

  8. Erythrocyte membrane fluidity and indices of plasmatic oxidative damage after acute physical exercise in humans.

    PubMed

    Berzosa, C; Gómez-Trullén, E M; Piedrafita, E; Cebrián, I; Martínez-Ballarín, E; Miana-Mena, F J; Fuentes-Broto, L; García, J J

    2011-06-01

    Optimal levels of membrane fluidity are essential for numerous cell functions including cell growth, solute transport and signal transduction. Since exercise enhances free radical production, our aim was to evaluate in healthy male subjects the effects of an acute bout of maximal and submaximal exercise on the erythrocyte membrane fluidity and its possible relation to the oxidative damage overproduction due to exercise. Subjects (n = 34) performed three cycloergometric tests: a continuous progressive exercise, a strenuous exercise until exhaustion and an acute bout of exercise at an intensity corresponding to 70% of maximal work capacity for 30 min. Venous blood samples were collected before and immediately after these exercises. Erythrocyte membrane fluidity was assessed by fluorescence spectroscopy. Plasma malondialdehyde (MDA) and 4-hydroxyalkenals (4-HDA) concentrations and carbonyl content of plasmatic proteins were used as an index of lipid and protein oxidation, respectively. Exercise produced a dramatic drop in the erythrocyte membrane fluidity as compared to resting time, but this was not accompanied by significant changes in the plasmatic MDA and 4-HDA concentrations. The highest erythrocyte membrane rigidity was detected immediately after strenuous exercise until exhaustion was performed. Protein carbonyl levels were higher after exhaustive exercises than at rest. Continuous progressive and strenuous exercises until exhaustion, but not submaximal workload, resulted in a significant enhanced accumulation of carbonylated proteins in the plasma. These findings are consistent with the idea that exercise exaggerates oxidative damage, which may contribute, at least partially, to explain the rigidity in the membrane of the erythrocytes due to acute exercise.

  9. DNA damage by the sulfate radical anion: hydrogen abstraction from the sugar moiety versus one-electron oxidation of guanine.

    PubMed

    Roginskaya, Marina; Mohseni, Reza; Ampadu-Boateng, Derrick; Razskazovskiy, Yuriy

    2016-07-01

    The products of oxidative damage to double-stranded (ds) DNA initiated by photolytically generated sulfate radical anions SO4(•-) were analyzed using reverse-phase (RP) high-performance liquid chromatography (HPLC). Relative efficiencies of two major pathways were compared: production of 8-oxoguanine (8oxoG) and hydrogen abstraction from the DNA 2-deoxyribose moiety (dR) at C1,' C4,' and C5' positions. The formation of 8oxoG was found to account for 87% of all quantified lesions at low illumination doses. The concentration of 8oxoG quickly reaches a steady state at about one 8oxoG per 100 base pairs due to further oxidation of its products. It was found that another guanine oxidation product identified as 2-amino-5-(2'-alkylamino)-4H-imidazol-4-one (X) was released in significant quantities from its tentative precursor 2-amino-5-[(2'-deoxy-β-d-erythro-pentofuranosyl)amino]-4H-imidazol-4-one (dIz) upon treatment with primary amines in neutral solutions. The linear dose dependence of X release points to the formation of dIz directly from guanine and not through oxidation of 8oxoG. The damage to dR was found to account for about 13% of the total damage, with majority of lesions (33%) originating from the C4' oxidation. The contribution of C1' oxidation also turned out to be significant (17% of all dR damages) despite of the steric problems associated with the abstraction of the C1'-hydrogen. However, no evidence of base-to-sugar free valence transfer as a possible alternative to direct hydrogen abstraction at C1' was found.

  10. In vitro effects of 50 Hz magnetic fields on oxidatively damaged rabbit red blood cells.

    PubMed

    Fiorani, M; Biagiarelli, B; Vetrano, F; Guidi, G; Dachà, M; Stocchi, V

    1997-01-01

    The aim of this study was to investigate the effects of 50 Hz magnetic fields (0.2-0.5 mT) on rabbit red blood cells (RBCs) that were exposed simultaneously to the action of an oxygen radical-generating system, Fe(II)/ascorbate. Previous data obtained in our laboratory showed at the exposure of rabbit erythrocytes or reticulocytes to Fe(II)/ascorbate hexokinase inactivation, whereas the other glycolytic enzymes do not show any decay. We also observed depletion of reduced glutathione (GSH) content with a concomitant intracellular and extracellular increase in oxidized glutathione (GSSG) and a decrease in energy charge. In this work we investigated whether 50 Hz magnetic fields could influence the intracellular impairments that occur when erythrocytes or reticulocytes are exposed to this oxidant system, namely, inactivation of hexokinase activity, GSH depletion, a change in energy charge, and hemoglobin oxidation. The results obtained indicate the a 0.5 mT magnetic field had no effect on intact RBCs, whereas it increased the damage with Fe(II)/ascorbate to a 0.5 mT magnetic field induced a significant further decay in hexokinase activity (about 20%) as well as a twofold increase in methemoglobin production compared with RBCs that were exposed to the oxidant system alone. Although further studies will be needed to determine the physiological implications of these data, the results reported in this study demonstrate that the effects of the magnetic fields investigated are able to potentiate the cellular damage induced in vitro by oxidizing agents.

  11. The effect of thiamine and thiamine pyrophosphate on oxidative liver damage induced in rats with cisplatin.

    PubMed

    Turan, Mehmet Ibrahim; Siltelioglu Turan, Isil; Mammadov, Renad; Altınkaynak, Konca; Kisaoglu, Abdullah

    2013-01-01

    The aim of this study was to investigate the effect of thiamine and thiamine pyrophosphate (TPP) on oxidative stress induced with cisplatin in liver tissue. Rats were divided into four groups; thiamine group (TG), TPP + cisplatin group (TPG), healthy animal group (HG), and cisplatin only group (CG). Oxidant and antioxidant parameters in liver tissue and AST, ALT, and LDH levels in rat sera were measured in all groups. Malondialdehyde levels in the CG, TG, TPG, and HG groups were 11 ± 1.4, 9 ± 0.5, 3 ± 0.5, and 2.2 ± 0.48  μ mol/g protein, respectively. Total glutathione levels were 2 ± 0.7, 2.8 ± 0.4, 7 ± 0.8, and 9 ± 0.6 nmol/g protein, respectively. Levels of 8-OH/Gua, a product of DNA damage, were 2.7 ± 0.4 pmol/L, 2.5 ± 0.5, 1.1 ± 0.3, and 0.9 ± 0.3 pmol/L, respectively. A statistically significant difference was determined in oxidant/antioxidant parameters and AST, ALT, and LDH levels between the TPG and CG groups (P < 0.05). No significant difference was determined between the TG and CG groups (P > 0.05). In conclusion, cisplatin causes oxidative damage in liver tissue. TPP seems to have a preventive effect on oxidative stress in the liver caused by cisplatin.

  12. The Effect of Thiamine and Thiamine Pyrophosphate on Oxidative Liver Damage Induced in Rats with Cisplatin

    PubMed Central

    Turan, Mehmet Ibrahim; Siltelioglu Turan, Isil; Mammadov, Renad; Altınkaynak, Konca; Kisaoglu, Abdullah

    2013-01-01

    The aim of this study was to investigate the effect of thiamine and thiamine pyrophosphate (TPP) on oxidative stress induced with cisplatin in liver tissue. Rats were divided into four groups; thiamine group (TG), TPP + cisplatin group (TPG), healthy animal group (HG), and cisplatin only group (CG). Oxidant and antioxidant parameters in liver tissue and AST, ALT, and LDH levels in rat sera were measured in all groups. Malondialdehyde levels in the CG, TG, TPG, and HG groups were 11 ± 1.4, 9 ± 0.5, 3 ± 0.5, and 2.2 ± 0.48 μmol/g protein, respectively. Total glutathione levels were 2 ± 0.7, 2.8 ± 0.4, 7 ± 0.8, and 9 ± 0.6 nmol/g protein, respectively. Levels of 8-OH/Gua, a product of DNA damage, were 2.7 ± 0.4 pmol/L, 2.5 ± 0.5, 1.1 ± 0.3, and 0.9 ± 0.3 pmol/L, respectively. A statistically significant difference was determined in oxidant/antioxidant parameters and AST, ALT, and LDH levels between the TPG and CG groups (P < 0.05). No significant difference was determined between the TG and CG groups (P > 0.05). In conclusion, cisplatin causes oxidative damage in liver tissue. TPP seems to have a preventive effect on oxidative stress in the liver caused by cisplatin. PMID:23841092

  13. The abilities of selenium dioxide and selenite ion to coordinate DNA-bound metal ions and decrease oxidative DNA damage.

    PubMed

    Hart, William E; Marczak, Steven P; Kneller, Andrew R; French, Robert A; Morris, Daniel L

    2013-08-01

    Several transition metals react with H2O2 and produce reactive oxygen species (ROS) responsible for oxidative damage linked to many diseases and disorders, and species that form coordination complexes with these metal ions show promise as antioxidants. The present study demonstrates that metal-mediated radical and non-radical oxidative DNA damage decreases when selenium dioxide (SeO2) and sodium selenite (Na2SeO3) are present. Radical-induced damage is associated with production of 8-hydroxy-2'-deoxyguanosine (8-OH-dG), which arises from ROS generated at or near the guanine base, and the selenium compounds reduce Fe(II)-, Cr(III)- and Cu(II)-mediated radical damage to differing degrees based on the identity of the metal ion and the order in which the metals, selenium compounds and DNA are combined. Radical damage arising from Fe(II) and Cr(III) decreases substantially when they are pre-incubated with the selenium compounds prior to adding DNA. Non-radical damage is associated with oxidation of the adenine base in the presence of high H2O2 concentrations through an ionic mechanism, and this type of damage also decreases significantly when the selenium compounds are allowed to interact with the metal ions before adding DNA. Fluorescence studies using dihydrodichlorofluorescein diacetate (DCF-DA) to probe ROS formation indicate that the majority of the SeO2- and SeO3(2-)-metal systems in combination with H2O2 (no DNA present) produce ROS to the same degree as the metal/H2O2 systems in the absence of the selenium compounds, suggesting that selenium-metal complexes react with H2O2 in a sacrificial manner that protects DNA from oxidative damage. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Drill-in fluid reduces formation damage, increases production rates

    SciTech Connect

    Hands, N.; Kowbel, K.; Nouris, R.

    1998-07-13

    A sodium formate drill-in fluid system reduced formation damage, resulting in better-than-expected production rates for an off-shore Dutch development well. Programmed to optimize production capacity and reservoir drainage from a Rotliegend sandstone gas discovery, the 5-7/8-in. subhorizontal production interval was drilled and completed barefoot with a unique, rheologically engineered sodium formate drill-in fluid system. The new system, consisting of a sodium formate (NaCOOH) brine as the base fluid and properly sized calcium carbonate as the formation-bridging agent, was selected on the basis of its well-documented record in reducing solids impairment and formation damage in similar sandstone structures in Germany. The system was engineered around the low-shear-rate viscosity (LSRV) concept, designed to provide exceptional rheological properties. After describing the drilling program, the paper gives results on the drilling and completion.

  15. Chemical Characterization and Reactivity of Fuel-Oxidizer Reaction Product

    NASA Technical Reports Server (NTRS)

    David, Dennis D.; Dee, Louis A.; Beeson, Harold D.

    1997-01-01

    Fuel-oxidizer reaction product (FORP), the product of incomplete reaction of monomethylhydrazine and nitrogen tetroxide propellants prepared under laboratory conditions and from firings of Shuttle Reaction Control System thrusters, has been characterized by chemical and thermal analysis. The composition of FORP is variable but falls within a limited range of compositions that depend on three factors: the fuel-oxidizer ratio at the time of formation; whether the composition of the post-formation atmosphere is reducing or oxidizing; and the reaction or post-reaction temperature. A typical composition contains methylhydrazinium nitrate, ammonium nitrate, methylammonium nitrate, and trace amounts of hydrazinium nitrate and 1,1-dimethylhydrazinium nitrate. Thermal decomposition reactions of the FORP compositions used in this study were unremarkable. Neither the various compositions of FORP, the pure major components of FORP, nor mixtures of FORP with propellant system corrosion products showed any unusual thermal activity when decomposed under laboratory conditions. Off-limit thruster operations were simulated by rapid mixing of liquid monomethylhydrazine and liquid nitrogen tetroxide in a confined space. These tests demonstrated that monomethylhydrazine, methylhydrazinium nitrate, ammonium nitrate, or Inconel corrosion products can induce a mixture of monomethylhydrazine and nitrogen tetroxide to produce component-damaging energies. Damaging events required FORP or metal salts to be present at the initial mixing of monomethylhydrazine and nitrogen tetroxide.

  16. Protective effect of erdosteine metabolite I against hydrogen peroxide-induced oxidative DNA-damage in lung epithelial cells.

    PubMed

    Marabini, Laura; Calò, Rossella; Braga, Pier Carlo

    2011-01-01

    It has been shown that the mucolytic agent erdosteine (N-carboxymethylthio-acetyl-homocysteine thiolactone, CAS 84611-23-4) has anti-inflammatory and anti-oxidant properties, and an active metabolite I (MET I) containing pharmacologically active sulphydryl group has been found to have a free radical scavenging activity. The aim of this study was to assess the ability of erdosteine metabolite I to protect A549 human lung adenocarcinoma cell against hydrogen peroxide (H2O2)-mediated oxidative stress and oxidative DNA damage. When A549 cells were pre-treated with the active metabolite I (2.5-5-10 microg/ml) for 10-30 min and then exposed to H2O2 (1-4 mM) for two additional hours at 37 degrees C, 5% at CO2, the intracellular peroxide production, reflected by dichlorofluorescein (DCF) fluorescence, decreased in a concentration-dependent manner. Furthermore, using a comet assay as an indicator for oxidative DNA damage, it was found that the metabolite I prevented damage to cells exposed to shortterm H2O2 treatment. The data suggest that this compound is effective in preventing H2O2-induced oxidative stress and DNA damage in A549 cells. The underlying mechanisms involve the scavenging of intracellular reactive oxygen species (ROS).

  17. Oxide production program monthly report - December 2014

    SciTech Connect

    Kelley, Evelyn A.; Whitworth, Julia; Lloyd, Jane Alexandria; Hampton, David Earl; Benavidez, Amelia A.

    2015-01-15

    A summary of the major activities, accomplishments, milestones, financial summary, project performance and issues facing the ARIES Oxide Production Program for the month of December 2014 is presented in this Executive Summary.

  18. Polymorphic trial in oxidative damage of arsenic exposed Vietnamese

    SciTech Connect

    Fujihara, Junko; Soejima, Mikiko; Yasuda, Toshihiro; Koda, Yoshiro; Kunito, Takashi; Iwata, Hisato; Tanabe, Shinsuke; Takeshita, Haruo

    2011-10-15

    Arsenic causes DNA damage and changes the cellular capacity for DNA repair. Genes in the base excision repair (BER) pathway influence the generation and repair of oxidative lesions. Single nucleotide polymorphisms (SNPs) in human 8-oxoguanine DNA glycosylase (hOGG1) Ser326Cys; apurinic/apyrimidinic endonuclease (APE1) Asp148Glu; X-ray and repair and cross-complementing group 1 (XRCC1) Arg280His and Arg399Gln in the BER genes were analyzed, and the relationship between these 4 SNPs and the urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) concentrations of 100 Vietnamese population exposed to arsenic was investigated. Individuals with hOGG1 326Cys/Cys showed significantly higher urinary 8-OHdG concentrations than did those with 326 Ser/Cys and Ser/Ser. As for APE1 Asp148Glu, heterozygous subjects showed significantly higher urinary 8-OHdG concentrations than did those homozygous for Asp/Asp. Moreover, global ethnic comparison of the allelic frequencies of the 4SNPs was performed in 10 population and previous reported data. The mutant allele frequencies of hOGG1 Ser326Cys in the Asian populations were higher than those in the African and Caucasian populations. As for APE1 Asp148Glu, Caucasians showed higher mutant frequencies than those shown by African and Asian populations. Among Asian populations, the Bangladeshi population showed relatively higher mutant allele frequencies of the APE1 Asp148Glu polymorphism. This study is the first to demonstrate the existence of genetic heterogeneity in a worldwide distribution of SNPs (hOGG1 Ser326Cys, APE1 Asp148Glu, XRCC1 Arg280His, and XRCC1 Arg399Gln) in the BER genes. - Highlights: > We showed that hOGG1 and APE1 are associated with urinary 8-OHdG concentrations. > We showed the existence of inter-ethnic differences in hOGG1 and APE1 polymorphism. > These polymorphisms is a genetic marker of susceptibility to oxidative stress.

  19. Preliminary evaluation of a model of stimulant use, oxidative damage, and executive dysfunction

    PubMed Central

    Winhusen, Theresa; Walker, Jessica; Brigham, Gregory; Lewis, Daniel; Somoza, Eugene; Theobald, Jeff; Somoza, Veronika

    2014-01-01

    Background Illicit stimulant use increases oxidative stress and oxidative stress has been found to be associated with deficits in memory, attention, and problem-solving. Objective To test a model of the association among oxidative DNA damage, a severe form of oxidative stress, and stimulant use, executive function, and stimulant-use outcomes. Methods Six sites evaluating 12-step facilitation for stimulant abusers obtained peripheral blood samples from methamphetamine-dependent (n=45) and cocaine-dependent (n=120) participants. The blood samples were submitted to a comet assay to assess oxidative DNA damage. Executive Dysfunction was assessed with the Frontal Systems Behavior Scale (FrSBe), which is a reliable and valid self-report assessment of executive dysfunction, disinhibition, and apathy. Stimulant-use measures included self-reported stimulant use and stimulant urine drug screens (UDS). Results While more recent cocaine use (<30 days abstinence) was associated with greater oxidative DNA damage (W=2.4, p<.05, d=.36), the results did not support the hypothesized relationship between oxidative DNA damage, executive dysfunction, and stimulant-use outcomes for cocaine-dependent patients. Support for the model was found for methamphetamine-dependent patients, with oxidative DNA damage significantly greater in methamphetamine-dependent patients with executive dysfunction (W=2.2, p<.05, d=.64) and with executive dysfunction being a significant mediator of oxidative DNA damage and stimulant use during active treatment (ab=0.089, p<.05). As predicted, neither disinhibition nor apathy were significant mediators of oxidative damage and future stimulant use. Conclusion These findings provide preliminary support for a model in which oxidative damage resulting from methamphetamine use results in executive dysfunction which in turn increases vulnerability to future stimulant use. PMID:23808868

  20. Magnesium sulfate affords protection against oxidative damage during severe preeclampsia.

    PubMed

    Abad, C; Vargas, F R; Zoltan, T; Proverbio, T; Piñero, S; Proverbio, F; Marín, R

    2015-02-01

    MgSO4 is the drug of choice to prevent seizures in preeclamptic pregnant women, but its mechanism of action at the molecular level remains an enigma. In previous works, we found that treating preeclamptic women with MgSO4 reduces the lipid peroxidation of their red blood cell membranes to normal levels and leads to a significant reduction in the osmotic fragility of the red blood cells that is increased during preeclampsia. In addition, the increase in lipid peroxidation of red cell membranes induced by the Fenton reaction does not occur when MgSO4 is present. The antioxidant protection of MgSO4 was evaluated in UV-C-treated red blood cell ghosts and syncytiotrophoblast plasma membranes by measuring their level of lipid peroxidation. The interaction of MgSO4 with free radicals was assessed for its association with the galvinoxyl radical, the quenching of H2O2-induced chemiluminescence and its effect on sensitized peroxidation of linoleic acid. a) MgSO4 protected red blood cell ghosts and the syncytiotrophoblast plasma membranes of normotensive pregnant women against lipid peroxidation induced by UV-C irradiation. b) MgSO4 does not seem to scavenge the galvinoxyl free radical. c) The quenching of the H2O2-enhanced luminol chemiluminescence is increased by the presence of MgSO4. d) The peroxidation of linoleic acid is significantly blocked by MgSO4. MgSO4 may provide protection against oxidative damage of plasma membranes through interactions with alkyl radicals. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Oxidative stress as a damage mechanism in porcine cumulus-oocyte complexes exposed to malathion during in vitro maturation.

    PubMed

    Flores, Diana; Souza, Verónica; Betancourt, Miguel; Teteltitla, Mario; González-Márquez, Humberto; Casas, Eduardo; Bonilla, Edmundo; Ramírez-Noguera, Patricia; Gutiérrez-Ruíz, María Concepción; Ducolomb, Yvonne

    2017-06-01

    Malathion is one of the most commonly used insecticides. Recent findings have demonstrated that it induces oxidative stress in somatic cells, but there are not enough studies that have demonstrated this effect in germ cells. Malathion impairs porcine oocyte viability and maturation, but studies have not shown how oxidative stress damages maturation and which biochemical mechanisms are affected in this process in cumulus-oocyte complexes (COCs). The aims of the present study were to determine the amount of oxidative stress produced by malathion in porcine COCs matured in vitro, to define how biochemical mechanisms affect this process, and determine whether trolox can attenuate oxidative damage. Sublethal concentrations 0, 750, and 1000 µM were used to evaluate antioxidant enzyme expressions, reactive oxygen species (ROS production), protein oxidation, and lipid peroxidation, among other oxidation products. COCs viability and oocyte maturation decreased in a concentration-dependent manner. Malathion increased Cu, Zn superoxide dismutase (SOD1), glutathione-S-transferase (GST), and glucose 6 phosphate dehydrogenase (G6PD) protein level and decreased glutathione peroxidase (GSH-Px) and catalase (CAT) protein level. Species reactives of oxygen (ROS), protein oxidation and Thiobarbituric acid reactive substances (TBARS) levels increased in COCs exposed to the insecticide, but when COCs were pre-treated with the trolox (50 µM) 30 min before and during malathion exposure, these parameters decreased down to control levels. This study showed that malathion has a detrimental effect on COCs during in vitro maturation, inducing oxidative stress, while trolox attenuated malathion toxicity by decreasing oxidative damage. © 2017 Wiley Periodicals, Inc.

  2. Vitamin D3 Reduces Tissue Damage and Oxidative Stress Caused by Exhaustive Exercise

    PubMed Central

    Ke, Chun-Yen; Yang, Fwu-Lin; Wu, Wen-Tien; Chung, Chen-Han; Lee, Ru-Ping; Yang, Wan-Ting; Subeq, Yi-Maun; Liao, Kuang-Wen

    2016-01-01

    Exhaustive exercise results in inflammation and oxidative stress, which can damage tissue. Previous studies have shown that vitamin D has both anti-inflammatory and antiperoxidative activity. Therefore, we aimed to test if vitamin D could reduce the damage caused by exhaustive exercise. Rats were randomized to one of four groups: control, vitamin D, exercise, and vitamin D+exercise. Exercised rats received an intravenous injection of vitamin D (1 ng/mL) or normal saline after exhaustive exercise. Blood pressure, heart rate, and blood samples were collected for biochemical testing. Histological examination and immunohistochemical (IHC) analyses were performed on lungs and kidneys after the animals were sacrificed. In comparison to the exercise group, blood markers of skeletal muscle damage, creatine kinase and lactate dehydrogenase, were significantly (P < 0.05) lower in the vitamin D+exercise group. The exercise group also had more severe tissue injury scores in the lungs (average of 2.4 ± 0.71) and kidneys (average of 3.3 ± 0.6) than the vitamin D-treated exercise group did (1.08 ± 0.57 and 1.16 ± 0.55). IHC staining showed that vitamin D reduced the oxidative product 4-Hydroxynonenal in exercised animals from 20.6% to 13.8% in the lungs and from 29.4% to 16.7% in the kidneys. In summary, postexercise intravenous injection of vitamin D can reduce the peroxidation induced by exhaustive exercise and ameliorate tissue damage, particularly in the kidneys and lungs. PMID:26941574

  3. Association of serum bilirubin with oxidant damage of human atherosclerotic plaques and the severity of atherosclerosis.

    PubMed

    Lapenna, Domenico; Ciofani, Giuliano; Pierdomenico, Sante Donato; Giamberardino, Maria Adele; Ucchino, Sante; Davì, Giovanni

    2017-09-25

    Bilirubin has protective effects against atherosclerotic cardiovascular diseases hypothetically due to its antioxidant-antilipoperoxidative properties. Thus, we investigated whether serum bilirubin is associated with oxidant damage, namely lipid peroxidation, of human atherosclerotic plaques and the severity of atherosclerosis. In this regard, we correlated the levels of serum total bilirubin (STB), direct (conjugated) bilirubin (SDB) and indirect (unconjugated) bilirubin (SIB) with those of fluorescent damage products of lipid peroxidation (FDPL) and lipid hydroperoxides (LOOH) of 32 endarterectomy-derived carotid atherosclerotic plaques. Moreover, we compared the levels of serum bilirubin and plaque lipoperoxides between two groups of patients of the study population with different severity of atherosclerosis as judged by the carotid stenosis degree, i.e., <90% (group A, n = 23) and ≥90% (group B, n = 9). Remarkably, the levels of STB were strongly inversely correlated with those of plaque FDPL (rS = -0.70, P < 0.0001) and LOOH (rS = -0.66, P < 0.0001), as were those of SIB (FDPL: rS = -0.68, P < 0.0001; LOOH: rS = -0.63, P < 0.0001). SDB had a weaker association with plaque FDPL (rS = -0.41, P < 0.05) and LOOH (rS = -0.35, P < 0.05). Moreover, the levels of STB, SDB and SIB were lower and those of plaque lipoperoxides higher in group B than in group A, pointing to the association of serum bilirubin and plaque oxidant burden with the severity of atherosclerosis. In conclusion, lowered serum bilirubin is associated with oxidant damage of human atherosclerotic plaques and the severity of atherosclerosis.

  4. [Role of rotenone in mitochondrial oxidative damage and the underlying mechanisms].

    PubMed

    Deng, Yong; Lu, Jun

    2014-10-01

    Rotenone is one of the typical inhibitors of the complex I on the mitochondrial respiratory chain. Numerous studies showed when applied to live animals or cells, rotenone could lead to mitochondrial dysfunction, ROS augment, and thus oxidative damage to proteins, lipids and nucleic acids. Through exploring the process of ROS generation in mitochondria, the relationship between rotenone and mitochondrial ROS generation and the role of rotenone in DNA damage, we elucidated the mechanisms of rotenone induced-mitochondrial oxidative damage. At the same time, we attempted to explore the mtDNA damage and the mutation induced by rotenone.

  5. Modification of radiation-induced oxidative damage in liposomal and microsomal membrane by eugenol

    NASA Astrophysics Data System (ADS)

    Pandey, B. N.; Lathika, K. M.; Mishra, K. P.

    2006-03-01

    Radiation-induced membrane oxidative damage, and their modification by eugenol, a natural antioxidant, was investigated in liposomes and microsomes. Liposomes prepared with DPH showed decrease in fluorescence after γ-irradiation, which was prevented significantly by eugenol and correlated with magnitude of oxidation of phospholipids. Presence of eugenol resulted in substantial inhibition in MDA formation in irradiated liposomes/microsomes, which was less effective when added after irradiation. Similarly, the increase in phospholipase C activity observed after irradiation in microsomes was inhibited in samples pre-treated with eugenol. Results suggest association of radio- oxidative membrane damage with alterations in signaling molecules, and eugenol significantly prevented these membrane damaging events.

  6. Mitochondrial Oxidative Stress, Mitochondrial DNA Damage and Their Role in Age-Related Vascular Dysfunction

    PubMed Central

    Mikhed, Yuliya; Daiber, Andreas; Steven, Sebastian

    2015-01-01

    The prevalence of cardiovascular diseases is significantly increased in the older population. Risk factors and predictors of future cardiovascular events such as hypertension, atherosclerosis, or diabetes are observed with higher frequency in elderly individuals. A major determinant of vascular aging is endothelial dysfunction, characterized by impaired endothelium-dependent signaling processes. Increased production of reactive oxygen species (ROS) leads to oxidative stress, loss of nitric oxide (•NO) signaling, loss of endothelial barrier function and infiltration of leukocytes to the vascular wall, explaining the low-grade inflammation characteristic for the aged vasculature. We here discuss the importance of different sources of ROS for vascular aging and their contribution to the increased cardiovascular risk in the elderly population with special emphasis on mitochondrial ROS formation and oxidative damage of mitochondrial DNA. Also the interaction (crosstalk) of mitochondria with nicotinamide adenosine dinucleotide phosphate (NADPH) oxidases is highlighted. Current concepts of vascular aging, consequences for the development of cardiovascular events and the particular role of ROS are evaluated on the basis of cell culture experiments, animal studies and clinical trials. Present data point to a more important role of oxidative stress for the maximal healthspan (healthy aging) than for the maximal lifespan. PMID:26184181

  7. Phenolic compounds from plants as nitric oxide production inhibitors.

    PubMed

    Conforti, F; Menichini, F

    2011-01-01

    Nitric oxide (NO) is a diatomic free radical produced from L-arginine by constitutive and inducible nitric oxide synthase (cNOS and iNOS) in numerous mammalian cells and tissues. Nitric oxide (NO), superoxide (O2-) and their reaction product peroxynitrite (ONOO-) may be generated in excess during the host response against viral and antibacterial infections and contribute to some pathogenesis by promoting oxidative stress, tissue injury and, even, cancer. Oxidative damage, caused by action of free radicals, may initiate and promote the progression of a number of chronic diseases, including cancer, cardiovascular diseases, Alzheimer's disease, diabetes and inflammation. The mechanism of inflammation injury is attributed, in part, to release of reactive oxygen species from activated neutrophils and macrophages. ROS propagate inflammation by stimulating release of mediators such as NO and cytokines. The interest of the research is motivated by the current need to find new substances of natural origin which have demonstrated effectiveness in the described fields of application and low degree of toxicity for humans. Natural products provide a vast pool of NO inhibitors that can possibly be developed into clinical products. This article reviews some plenolic secondary metabolites from plants with NO inhibitory properties and their structure-activity relationship studies that can be focused for drug development programs.

  8. [The effects of oxidative damage induced by organic oxidant t-BHP on cochlear hair cells].

    PubMed

    Chen, Li-mei; Guo, Xiao; Li, Xu-dong; Wang, Zhi; Liu, Yi-min

    2012-03-01

    To establish the oxidative damage model of cochlea hair cells using organic oxidant t-BHP in vitro. HEI-OC1 cells were exposed to t-BHP at 8 doses (30~4000 µmol/L) for 12 h. Trypan blue test was used to detected the cellular viability and MTT assay was utilized to measured the cellular proliferation. The intracellular ROS levels were determined by 2,7-dichlorodihydrofluorescein diacetate (DCFH-DA). The survival rates of HEI-OC1 cells started decrease significantly at the dose of 100 µmol/L t-BHP, the peak of decreased survival rates appeared at the doses of 200~800 µmol/L. The results of MTT assay demonstrated that 30 µmol/L t-BHP could promote cellular proliferation ability, when t-BHP concentrations were higher than 200 µmol/L, the cellular proliferation ability was inhibited. The results of DCFH-DA assay showed that there was no fluorescence in control group, the strong fluorescence was observed in positive control group, the weak fluorescence was observed in 30~50 µmol/L t-BHP groups, the bright fluorescence was observed in 100 µmol/L t-BHP group, still the stronger fluorescence was observed in 200~1000 µmol/L groups, but the cellular number decreased with the doses because of the lower cellular viability. The exposure to 100 µmol/L t-BHP for 12 h could simulate the oxidative damage induced by noise in cochlear hair cells.

  9. Arabidopsis mutants lacking phenolic sunscreens exhibit enhanced ultraviolet-B injury and oxidative damage.

    PubMed Central

    Landry, L G; Chapple, C C; Last, R L

    1995-01-01

    We have assessed ultraviolet-B (UV-B)-induced injury in wild-type Arabidopsis thaliana and two mutants with altered aromatic secondary product biosynthesis. Arabidopsis mutants defective in the ability to synthesize UV-B-absorbing compounds (flavonoids in transparent testa 5 [tt5] and sinapate esters in ferulic acid hydroxylase 1 [fah1]) are more sensitive to UV-B than is the wild-type Landsberg erecta. Despite its ability to accumulate UV-absorptive flavonoid compounds, the ferulic acid hydroxylase mutant fah1 exhibits more physiological injury (growth inhibition and foliar lesions) than either wild type or tt5. The extreme UV-B sensitivity of fah1 demonstrates the importance of hydroxycinnamate esters as UV-B protectants. Consistent with the whole-plant response, the highest levels of lipid and protein oxidation products were seen in fah1. Ascorbate peroxidase enzyme activity was also increased in the leaves of UV-B-treated plants in a dose- and genotype-dependent manner. These results demonstrate that, in A. thaliana, hydroxycinnamates are more effective UV-B protectants than flavonoids. The data also indicate that A. thaliana responds to UV-B as an oxidative stress, and sunscreen compounds reduce the oxidative damage caused by UV-B. PMID:8539286

  10. Arabidopsis mutants lacking phenolic sunscreens exhibit enhanced ultraviolet-B injury and oxidative damage

    SciTech Connect

    Landry, L.G.; Last, R.L.; Chapple, C.C.S.

    1995-12-01

    We have assessed ultraviolet-B (UV-B)-induced injury in wild-type Arabidopsis thaliana and two mutants with altered aromatic secondary product biosynthesis. Arabidopsis mutants defective in the ability to synthesize UV-B-absorbing compounds (flavonoids in transparent testa 5 [tt5] and sinapate esters in ferulic acid hydroxylase 1 [fah 1]) are more sensitive to UV-B than is the wild-type Landsberg erecta. Despite its ability to accumulate UV-absorptive flavonoid compounds, the ferulic acid hydroxylase mutant fah1 exhibits more physiological injury (growth inhibition and foliar lesions) than either wild type or tt5. The extreme UV-B sensitivity of fah1 demonstrates the importance of hydroxycinnamate esters as UV-B protectants. Consistent with the whole-plant response, the highest levels of lipid and protein oxidation products were seen in fah1. Ascorbate peroxidase enzyme activity was also increased in the leaves of UV-B-treated plants in a dose- and genotype-dependent manner. These results demonstrate that, in A. thaliana, hydryoxycinnamates are more effective UV-B protectants than flavonoids. The data also indicate that A. thaliana responds to UV-B as an oxidative stress, and sunscreen compounds reduce the oxidative damage caused by UV-B. 36 refs., 6 figs.

  11. Protein oxidative damage and heme oxygenase in sunlight-exposed human skin: roles of MAPK responses to oxidative stress.

    PubMed

    Akasaka, Emiko; Takekoshi, Susumu; Horikoshi, Yosuke; Toriumi, Kentarou; Ikoma, Norihiro; Mabuchi, Tomotaka; Tamiya, Shiho; Matsuyama, Takashi; Ozawa, Akira

    2010-12-20

    Oxidative stress derived from ultraviolet (UV) light in sunlight induces different hazardous effects in the skin, including sunburn, photo-aging and DNA mutagenesis. In this study, the protein-bound lipid peroxidation products 4-hydroxy-2-nonenal (HNE) and the oxidative DNA damage marker 8-hydroxy-2'-deoxyguanosine (8OHdG) were investigated in chronically sun-exposed and sun-protected human skins using immunohistochemistry. The levels of antioxidative enzymes, such as heme oxygenase 1 and 2, Cu/Zn-SOD, Mn-SOD and catalase, were also examined. Oxidative stress is also implicated in the activation of signal transduction pathways, such as mitogen-activated protein kinase (MAPK). Therefore, the expression and distribution of phosphorylated p38 MAPK, phosphorylated Jun N-terminal kinase (JNK) and phosphorylated extracellular signal-regulated kinase (ERK) were observed. Skin specimens were obtained from the surgical margins. Chronically sunlight-exposed skin samples were taken from the ante-auricular (n = 10) and sunlight-protected skin samples were taken from the post-auricular (n = 10). HNE was increased in the chronically sunlight-exposed skin but not in the sunlight-protected skin. The expression of heme oxygenase-2 was markedly increased in the sunlight-exposed skin compared with the sun-protected skin. In contrast, the intensity of immunostaining of Cu/Zn-SOD, Mn-SOD and catalase was not different between the two areas. Phosphorylated p38 MAPK and phosphorylated JNK accumulated in the ante-auricular dermis and epidermis, respectively. These data show that particular anti-oxidative enzymes function as protective factors in chronically sunlight-exposed human skin. Taken together, our results suggest (1) antioxidative effects of heme oxygenase-2 in chronically sunlight-exposed human skin, and that (2) activation of p38 MAPK may be responsible for oxidative stress.

  12. Does the oxidative stress theory of aging explain longevity differences in birds? II. Antioxidant systems and oxidative damage.

    PubMed

    Montgomery, Magdalene K; Buttemer, William A; Hulbert, A J

    2012-03-01

    The oxidative damage hypothesis of aging posits that the accumulation of oxidative damage is a determinant of an animal species' maximum lifespan potential (MLSP). Recent findings in extremely long-living mammal species such as naked mole-rats challenge this proposition. Among birds, parrots are exceptionally long-living with an average MLSP of 25 years, and with some species living more than 70 years. By contrast, quail are among the shortest living bird species, averaging about 5-fold lower MLSP than parrots. To test if parrots have correspondingly (i) superior antioxidant protection and (ii) lower levels of oxidative damage compared to similar-sized quail, we measured (i) total antioxidant capacity, uric acid and reduced glutathione (GSH) levels, as well as the activities of enzymatic antioxidants (superoxide dismutase, glutathione peroxidase and catalase), and (ii) markers of mitochondrial DNA damage (8-OHdG), protein damage (protein carbonyls) and lipid peroxidation (lipid hydroperoxides and TBARS) in three species of long-living parrots and compared these results to corresponding measures in two species of short-living quails (average MLSP=5.5 years). All birds were fed the same diet to exclude differences in dietary antioxidant levels. Tissue antioxidants and oxidative damage were determined both 'per mg protein' and 'per g tissue'. Only glutathione peroxidase was consistently higher in tissues of the long-living parrots and suggests higher protection against the harmful effects of hydroperoxides, which might be important for parrot longevity. The levels of oxidative damage were mostly statistically indistinguishable between parrots and quails (67%), occasionally higher (25%), but rarely lower (8%) in the parrots. Despite indications of higher protection against some aspects of oxidative stress in the parrots, the pronounced longevity of parrots appears to be independent of their antioxidant mechanisms and their accumulation of oxidative damage.

  13. Tetramethylpyrazine protects palmitate-induced oxidative damage and mitochondrial dysfunction in C2C12 myotubes.

    PubMed

    Gao, Xin; Zhao, Xiao-long; Zhu, Yan-hui; Li, Xiao-mu; Xu, Qiong; Lin, Huan-dong; Wang, Ming-wei

    2011-04-25

    Tetramethylpyrazine (TMP), one of the active ingredients isolated from a Chinese herbal prescription, possesses protective effects against oxidative stress caused by high glucose in endothelial cells. In this study, the role of TMP in preventing muscle cells from palmitate-induced oxidative damage was investigated and the possible mechanisms of action elucidated. Mitochondrial reactive oxygen species (ROS) were measured in C2C12 myotubes, a palmitate-induced oxidative stress cell model, with or without TMP. Both mitochondrial membrane potential (MMP) and oxygen consumption were assessed in conjunction with quantification of mitochondrial DNA and mitochondrial biogenesis-related factors, such as peroxisome proliferator-activated receptor-γ coactivator 1 α (PGC1α), nuclear respiratory factor 1 (NRF1) and mitochondrial transcription factor A (Tfam), by real-time polymerase chain reaction. Expression of mitochondrial respiratory chain complex III as an index of mitochondrial function was evaluated by immunoblotting, and glucose transport into the C2C12 myotube examined by analyzing 2-deoxy-[(3)H]glucose uptake. TMP significantly alleviated palmitate-induced mitochondrial ROS production, mitigated mitochondrial dysfunction and increased D-loop mRNA expression as compared with the control. This was accompanied by a marked reversal of palmitate-induced down-regulation in the expression of mitochondrial biogenesis-related factors (PGC1α, NRF1 and Tfam) and decreased glucose uptake in C2C12 myotubes. As a result, cell respiration, as reflected by the elevated expression of mitochondrial respiratory chain complex III and oxygen consumption, was enhanced. TMP is capable of protecting C2C12 myotubes against palmitate-induced oxidative damage and mitochondrial dysfunction, and improving glucose uptake in muscle cells partially through the up-regulation of mitochondrial biogenesis. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. Biomarkers of oxidative stress and DNA damage in agricultural workers: A pilot study

    SciTech Connect

    Muniz, Juan F. McCauley, Linda; Scherer, J.; Lasarev, M.; Koshy, M.; Kow, Y.W.; Nazar-Stewart, Valle; Kisby, G.E.

    2008-02-15

    Oxidative stress and DNA damage have been proposed as mechanisms linking pesticide exposure to health effects such as cancer and neurological diseases. A study of pesticide applicators and farmworkers was conducted to examine the relationship between organophosphate pesticide exposure and biomarkers of oxidative stress and DNA damage. Urine samples were analyzed for OP metabolites and 8-hydroxy-2'-deoxyguanosine (8-OH-dG). Lymphocytes were analyzed for oxidative DNA repair activity and DNA damage (Comet assay), and serum was analyzed for lipid peroxides (i.e., malondialdehyde, MDA). Cellular damage in agricultural workers was validated using lymphocyte cell cultures. Urinary OP metabolites were significantly higher in farmworkers and applicators (p < 0.001) when compared to controls. 8-OH-dG levels were 8.5 times and 2.3 times higher in farmworkers or applicators (respectively) than in controls. Serum MDA levels were 4.9 times and 24 times higher in farmworkers or applicators (respectively) than in controls. DNA damage (Comet assay) and oxidative DNA repair were significantly greater in lymphocytes from applicators and farmworkers when compared with controls. Markers of oxidative stress (i.e., increased reactive oxygen species and reduced glutathione levels) and DNA damage were also observed in lymphocyte cell cultures treated with an OP. The findings from these in vivo and in vitro studies indicate that organophosphate pesticides induce oxidative stress and DNA damage in agricultural workers. These biomarkers may be useful for increasing our understanding of the link between pesticides and a number of health effects.

  15. 17β-estradiol prevents experimentally-induced oxidative damage to membrane lipids and nuclear DNA in porcine ovary.

    PubMed

    Stepniak, Jan; Karbownik-Lewinska, Malgorzata

    2016-01-01

    Estrogens, with their principle representative 17β-estradiol, contribute to the redox state of cells showing both pro- and antioxidative properties. In the ovary, being the main source of estrogens, maintaining balance between the production and detoxification of ROS is crucial. Whereas ovary estrogen concentration is difficult to estimate, its circulating concentration in women may reach the nanomolar level. The aim of the study was to evaluate the effects of 17β-estradiol on oxidative damage to membrane lipids (lipid peroxidation, LPO) and to nuclear DNA in the porcine ovary under basal conditions and in the presence of Fenton reaction (Fe(2+)+H2O2→Fe(3+)+(•)OH + OH(-)) substrates. Ovary homogenates and DNA were incubated in the presence of 17β-estradiol (1 mM-1 pM), without/with FeSO4 (30 μM) + H2O2 (0.5 mM). Malondialdehyde + 4-hydroxyalkenals (MDA + 4-HDA) concentration (LPO index) was measured spectrophotometrically. The concentration of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) (DNA damage index) was measured by HPLC. We observed that 17β-estradiol did not alter the basal level of oxidative damage, but reduced Fe(2+)+H2O2-induced oxidative damage to membrane lipids when ≥10 nM and to DNA at concentrations ≥1 nM. In the ovary at near physiological concentration, 17β-estradiol prevents experimentally induced oxidative damage. This suggests that under physiological conditions this hormone may contribute to protecting the ovary against oxidative damage.

  16. Withaferin A Induces Oxidative Stress-Mediated Apoptosis and DNA Damage in Oral Cancer Cells.

    PubMed

    Chang, Hsueh-Wei; Li, Ruei-Nian; Wang, Hui-Ru; Liu, Jing-Ru; Tang, Jen-Yang; Huang, Hurng-Wern; Chan, Yu-Hsuan; Yen, Ching-Yu

    2017-01-01

    Withaferin A (WFA) is one of the most active steroidal lactones with reactive oxygen species (ROS) modulating effects against several types of cancer. ROS regulation involves selective killing. However, the anticancer and selective killing effects of WFA against oral cancer cells remain unclear. We evaluated whether the killing ability of WFA is selective, and we explored its mechanism against oral cancer cells. An MTS tetrazolium cell proliferation assay confirmed that WFA selectively killed two oral cancer cells (Ca9-22 and CAL 27) rather than normal oral cells (HGF-1). WFA also induced apoptosis of Ca9-22 cells, which was measured by flow cytometry for subG1 percentage, annexin V expression, and pan-caspase activity, as well as western blotting for caspases 1, 8, and 9 activations. Flow cytometry analysis shows that WFA-treated Ca9-22 oral cancer cells induced G2/M cell cycle arrest, ROS production, mitochondrial membrane depolarization, and phosphorylated histone H2A.X (γH2AX)-based DNA damage. Moreover, pretreating Ca9-22 cells with N-acetylcysteine (NAC) rescued WFA-induced selective killing, apoptosis, G2/M arrest, oxidative stress, and DNA damage. We conclude that WFA induced oxidative stress-mediated selective killing of oral cancer cells.

  17. Age-related NADH oxidase (arNOX)-catalyzed oxidative damage to skin proteins.

    PubMed

    Meadows, Christiaan; Morré, D James; Morré, Dorothy M; Draelos, Zoe D; Kern, Dale

    2014-09-01

    Age-related NADH oxidase (arNOX), a cell surface-located hydroquinone oxidase capable of superoxide generation, appears at age 30 and increases with age thereafter. The ectodomain of arNOX is shed from the cell surface into body fluids including sera and saliva where its activity was measured spectrophotometrically using a reduction of ferricytochrome c as a measure of superoxide generation. The autofluorescence of advanced glycation end products correlates with epidermal arNOX activity as well. To demonstrate protein cross-linking, a fluorescence-labeled analog of tyrosine, tyramine, that would react with proteins carrying arNOX-generated tyrosyl radicals was used. The assay demonstrated the potential for arNOX-induced oxidative damage (dityrosine formation) to human collagen and elastin and to other surface proteins of intact human embryo fibroblasts and frozen sections from epidermal punch biopsies. The findings support a role for arNOX as a major source of oxidative damage leading to cross-linking of skin proteins.

  18. Amelioration of Isoproterenol-Induced Oxidative Damage in Rat Myocardium by Withania somnifera Leaf Extract

    PubMed Central

    Khalil, Md. Ibrahim; Ahmmed, Istiyak; Ahmed, Romana; Tanvir, E. M.; Afroz, Rizwana; Paul, Sudip; Gan, Siew Hua; Alam, Nadia

    2015-01-01

    We investigated the protective role of Withania somnifera leaf extract (WSLEt) on isoproterenol- (ISO-) induced myocardial infarction (MI) in rats. Subcutaneous injection of ISO (85 mg/kg body weight (b.w.)) administered to rats for two consecutive days caused a significant increase in cardiac troponin I (cTnI) levels and serum lipid profiles, as well as the activities of some marker enzymes. In addition to these diagnostic markers, there were increased levels of lipid peroxidation (LPO) and decreased activities of enzymatic antioxidants (superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GRx), and glutathione-S-transferase (GST)) in the myocardium. However, oral pretreatment (100 mg/kg b.w.) with WSLEt for 4 weeks elicited a significant cardioprotective activity by lowering the levels of cTnI, lipid profiles, and marker enzymes. The levels of LPO products were also significantly decreased. Elevated activities of antioxidant enzymes were also observed in rats pretreated with WSLEt. As further confirmed histopathologically, our findings strongly suggest that the cardioprotective effect of WSLEt on myocardium experiencing ISO-induced oxidative damage may be due to an augmentation of the endogenous antioxidant system and an inhibition of LPO in the myocardial membrane. We conclude that WSLEt confers some protection against oxidative damage in ISO-induced MI in rats. PMID:26539517

  19. Changes of thioredoxin, oxidative stress markers, inflammation and muscle/renal damage following intensive endurance exercise.

    PubMed

    Sugama, Kaoru; Suzuki, Katsuhiko; Yoshitani, Kayo; Shiraishi, Koso; Miura, Shigeki; Yoshioka, Hiroshi; Mori, Yuichi; Kometani, Takashi

    2015-01-01

    Thioredoxin (TRX) is a 12 kDa protein that is induced by oxidative stress, scavenges reactive oxygen species (ROS) and modulates chemotaxis. Furthermore it is thought to play a protective role in renal ischemia/reperfusion injury. Complement 5a (C5a) is a chemotactic factor of neutrophils and is produced after ischemia/reperfusion injury in the kidney. Both TRX and C5a increase after endurance exercise. Therefore, it may be possible that TRX has an association with C5a in renal disorders and/or renal protection caused by endurance exercise. Accordingly, the aim of this study was to investigate relationships among the changes of urine levels of TRX, C5a and acute kidney injury (AKI) caused by ischemia/reperfusion, inflammatory responses, and oxidative stress following intensive endurance exercise. Also, we applied a newly-developed measurement system of neutrophil migratory activity and ROS-production by use of ex vivo hydrogel methodology with an extracellular matrix to investigate the mechanisms of muscle damage. Fourteen male triathletes participated in a duathlon race consisting of 5 km of running, 40 km of cycling and 5 km of running were recruited to the study. Venous blood and urine samples were collected before, immediately following, 1.5 h and 3 h after the race. Plasma, serum and urine were analyzed using enzyme-linked immunosorbent assays, a free radical analytical system, and the ex vivo neutrophil functional measurement system. These data were analyzed by assigning participants to damaged and minor-damage groups by the presence and absence of renal tubular epithelial cells in the urinary sediments. We found strong associations among urinary TRX, C5a, interleukin (IL)-2, IL-4, IL-8, IL-10, interferon (IFN)-γ and monocyte chemotactic protein (MCP)-1. From the data it might be inferred that urinary TRX, MCP-1 and β-N-acetyl-D-glucosaminidase (NAG) were associated with renal tubular injury. Furthermore, TRX may be influenced by levels of IL-10, regulate

  20. Oxidative stress and DNA damage induced by imidacloprid in zebrafish (Danio rerio).

    PubMed

    Ge, Weili; Yan, Saihong; Wang, Jinhua; Zhu, Lusheng; Chen, Aimei; Wang, Jun

    2015-02-18

    Imidacloprid is a neonicotinoid insecticide that can have negative effects on nontarget animals. The present study was conducted to assess the toxicity of various imidacloprid doses (0.3, 1.25, and 5 mg/mL) on zebrafish sampled after 7, 14, 21, and 28 days of exposure. The levels of catalase (CAT), superoxide dismutase (SOD), reactive oxygen species (ROS), glutathione-S-transferase (GST), and malondialdehyde (MDA) and the extent of DNA damage were measured to evaluate the toxicity of imidacloprid on zebrafish. SOD and GST activities were noticeably increased during early exposure but were inhibited toward the end of the exposure period. In addition, the CAT levels decreased to the control level following their elevation during early exposure. High concentrations of imidacloprid (1.25 and 5 mg/L) induced excessive ROS production and markedly increased MDA content on the 21st day of exposure. DNA damage was dose- and time-dependent. In conclusion, the present study showed that imidacloprid can induce oxidative stress and DNA damage in zebrafish.

  1. Resveratrol protects mouse oocytes from methylglyoxal-induced oxidative damage.

    PubMed

    Liu, Yu; He, Xiao-Qin; Huang, Xin; Ding, Lu; Xu, Lin; Shen, Yu-Ting; Zhang, Fei; Zhu, Mao-Bi; Xu, Bai-Hui; Qi, Zhong-Quan; Wang, Hai-Long

    2013-01-01

    Methylglyoxal, a reactive dicarbonyl compound, is mainly formed from glycolysis. Methylglyoxal can lead to the dysfunction of mitochondria, the depletion of cellular anti-oxidation enzymes and the formation of advanced glycation ends. Previous studies showed that the accumulation of methylglyoxal and advanced glycation ends can impair the oocyte maturation and reduce the oocyte quality in aged and diabetic females. In this study, we showed that resveratrol, a kind of phytoalexin found in the skin of grapes, red wine and other botanical extracts, can alleviate the adverse effects caused by methylglyoxal, such as inhibition of oocyte maturation and disruption of spindle assembly. Besides, methylglyoxal-treated oocytes displayed more DNA double strands breaks and this can also be decreased by treatment of resveratrol. Further investigation of these processes revealed that methylglyoxal may affect the oocyte quality by resulting in excessive reactive oxygen species production, aberrant mitochondrial distribution and high level lipid peroxidation, and resveratrol can block these cytotoxic changes. Collectively, our results showed that resveratrol can protect the oocytes from methylglyoxal-induced cytotoxicity and this was mainly through the correction of the abnormity of cellular reactive oxygen species metabolism.

  2. AMBIENT PARTICULATE MATTER STIMULATES OXIDATIVE STRESS IN BRAIN MICROGLIA AND DAMAGES NEURONS IN CULTURE.

    EPA Science Inventory

    Ambient particulate matter (PM) damages biological targets through oxidative stress (OS) pathways. Several reports indicate that the brain is one of those targets. Since microglia (brain macrophage) are critical to OS-mediated neurodegeneration, their response to concentrated amb...

  3. Oxidative damage increases with reproductive energy expenditure and is reduced by food-supplementation

    PubMed Central

    Fletcher, Quinn E.; Selman, Colin; Boutin, Stan; McAdam, Andrew G.; Woods, Sarah B.; Seo, Arnold Y.; Leeuwenburgh, Christiaan; Speakman, John R.; Humphries, Murray M.

    2013-01-01

    A central principle in life-history theory is that reproductive effort negatively affects survival. Costs of reproduction are thought to be physiologically-based, but the underlying mechanisms remain poorly understood. Using female North American red squirrels (Tamiasciurus hudsonicus), we test the hypothesis that energetic investment in reproduction overwhelms investment in antioxidant protection, leading to oxidative damage. In support of this hypothesis we found that the highest levels of plasma protein oxidative damage in squirrels occurred during the energetically-demanding period of lactation. Moreover, plasma protein oxidative damage was also elevated in squirrels that expended the most energy and had the lowest antioxidant protection. Finally, we found that squirrels that were food-supplemented during lactation and winter had increased antioxidant protection and reduced plasma protein oxidative damage providing the first experimental evidence in the wild that access to abundant resources can reduce this physiological cost. PMID:23617928

  4. AMBIENT PARTICULATE MATTER STIMULATES OXIDATIVE STRESS IN BRAIN MICROGLIA AND DAMAGES NEURONS IN CULTURE.

    EPA Science Inventory

    Ambient particulate matter (PM) damages biological targets through oxidative stress (OS) pathways. Several reports indicate that the brain is one of those targets. Since microglia (brain macrophage) are critical to OS-mediated neurodegeneration, their response to concentrated amb...

  5. Protective effect of pomegranate-derived products on UVB-mediated damage in human reconstituted skin.

    PubMed

    Afaq, Farrukh; Zaid, Mohammad Abu; Khan, Naghma; Dreher, Mark; Mukhtar, Hasan

    2009-06-01

    Solar ultraviolet (UV) radiation, particularly its UVB (290-320 nm) component, is the primary cause of many adverse biological effects including photoageing and skin cancer. UVB radiation causes DNA damage, protein oxidation and induces matrix metalloproteinases (MMPs). Photochemoprevention via the use of botanical antioxidants in affording protection to human skin against UVB damage is receiving increasing attention. Pomegranate, from the tree Punica granatum, contains anthocyanins and hydrolysable tannins and possesses strong antioxidant and anti-tumor-promoting properties. In this study, we determined the effect of pomegranate-derived products--POMx juice, POMx extract and pomegranate oil (POMo)--against UVB-mediated damage using reconstituted human skin (EpiDerm(TM) FT-200). EpiDerm was treated with POMx juice (1-2 microl/0.1 ml/well), POMx extract (5-10 microg/0.1 ml/well) and POMo (1-2 microl/0.1 ml/well) for 1 h prior to UVB (60 mJ/cm(2)) irradiation and was harvested 12 h post-UVB to assess protein oxidation, markers of DNA damage and photoageing by Western blot analysis and immunohistochemistry. Pretreatment of Epiderm with pomegranate-derived products resulted in inhibition of UVB-induced (i) cyclobutane pyrimidine dimers (CPD), (ii) 8-dihydro-2'-deoxyguanosine (8-OHdG), (iii) protein oxidation and (iv) proliferating cell nuclear antigen (PCNA) protein expression. We also found that pretreatment of Epiderm with pomegranate-derived products resulted in inhibition of UVB-induced (i) collagenase (MMP-1), (ii) gelatinase (MMP-2, MMP-9), (iii) stromelysin (MMP-3), (iv) marilysin (MMP-7), (v) elastase (MMP-12) and (vi) tropoelastin. Gelatin zymography revealed that pomegranate-derived products inhibited UVB-induced MMP-2 and MMP-9 activities. Pomegranate-derived products also caused a decrease in UVB-induced protein expression of c-Fos and phosphorylation of c-Jun. Collectively, these results suggest that all three pomegranate-derived products may be useful

  6. Diminution of Oxidative Damage to Human Erythrocytes and Lymphocytes by Creatine: Possible Role of Creatine in Blood.

    PubMed

    Qasim, Neha; Mahmood, Riaz

    2015-01-01

    Creatine (Cr) is naturally produced in the body and stored in muscles where it is involved in energy generation. It is widely used, especially by athletes, as a staple supplement for improving physical performance. Recent reports have shown that Cr displays antioxidant activity which could explain its beneficial cellular effects. We have evaluated the ability of Cr to protect human erythrocytes and lymphocytes against oxidative damage. Erythrocytes were challenged with model oxidants, 2, 2'-azobis(2-amidinopropane) dihydrochloride (AAPH) and hydrogen peroxide (H2O2) in the presence and absence of Cr. Incubation of erythrocytes with oxidant alone increased hemolysis, methemoglobin levels, lipid peroxidation and protein carbonyl content. This was accompanied by decrease in glutathione levels. Antioxidant enzymes and antioxidant power of the cell were compromised while the activity of membrane bound enzyme was lowered. This suggests induction of oxidative stress in erythrocytes by AAPH and H2O2. However, Cr protected the erythrocytes by ameliorating the AAPH and H2O2 induced changes in these parameters. This protective effect was confirmed by electron microscopic analysis which showed that oxidant-induced cell damage was attenuated by Cr. No cellular alterations were induced by Cr alone even at 20 mM, the highest concentration used. Creatinine, a by-product of Cr metabolism, was also shown to exert protective effects, although it was slightly less effective than Cr. Human lymphocytes were similarly treated with H2O2 in absence and presence of different concentrations of Cr. Lymphocytes incubated with oxidant alone had alterations in various biochemical and antioxidant parameters including decrease in cell viability and induction of DNA damage. The presence of Cr attenuated all these H2O2-induced changes in lymphocytes. Thus, Cr can function as a blood antioxidant, protecting cells from oxidative damage, genotoxicity and can potentially increase their lifespan.

  7. Diminution of Oxidative Damage to Human Erythrocytes and Lymphocytes by Creatine: Possible Role of Creatine in Blood

    PubMed Central

    Qasim, Neha; Mahmood, Riaz

    2015-01-01

    Creatine (Cr) is naturally produced in the body and stored in muscles where it is involved in energy generation. It is widely used, especially by athletes, as a staple supplement for improving physical performance. Recent reports have shown that Cr displays antioxidant activity which could explain its beneficial cellular effects. We have evaluated the ability of Cr to protect human erythrocytes and lymphocytes against oxidative damage. Erythrocytes were challenged with model oxidants, 2, 2'-azobis(2-amidinopropane) dihydrochloride (AAPH) and hydrogen peroxide (H2O2) in the presence and absence of Cr. Incubation of erythrocytes with oxidant alone increased hemolysis, methemoglobin levels, lipid peroxidation and protein carbonyl content. This was accompanied by decrease in glutathione levels. Antioxidant enzymes and antioxidant power of the cell were compromised while the activity of membrane bound enzyme was lowered. This suggests induction of oxidative stress in erythrocytes by AAPH and H2O2. However, Cr protected the erythrocytes by ameliorating the AAPH and H2O2 induced changes in these parameters. This protective effect was confirmed by electron microscopic analysis which showed that oxidant-induced cell damage was attenuated by Cr. No cellular alterations were induced by Cr alone even at 20 mM, the highest concentration used. Creatinine, a by-product of Cr metabolism, was also shown to exert protective effects, although it was slightly less effective than Cr. Human lymphocytes were similarly treated with H2O2 in absence and presence of different concentrations of Cr. Lymphocytes incubated with oxidant alone had alterations in various biochemical and antioxidant parameters including decrease in cell viability and induction of DNA damage. The presence of Cr attenuated all these H2O2-induced changes in lymphocytes. Thus, Cr can function as a blood antioxidant, protecting cells from oxidative damage, genotoxicity and can potentially increase their lifespan. PMID

  8. A Comparison of the Effects of Neuronal Nitric Oxide Synthase and Inducible Nitric Oxide Synthase Inhibition on Cartilage Damage.

    PubMed

    Gokay, Nevzat Selim; Yilmaz, Ibrahim; Komur, Baran; Demiroz, Ahu Senem; Gokce, Alper; Dervisoglu, Sergülen; Gokay, Banu Vural

    2016-01-01

    The objective of this study was to investigate the effects of selective inducible nitric oxide synthase and neuronal nitric oxide synthase inhibitors on cartilage regeneration. The study involved 27 Wistar rats that were divided into five groups. On Day 1, both knees of 3 rats were resected and placed in a formalin solution as a control group. The remaining 24 rats were separated into 4 groups, and their right knees were surgically damaged. Depending on the groups, the rats were injected with intra-articular normal saline solution, neuronal nitric oxide synthase inhibitor 7-nitroindazole (50 mg/kg), inducible nitric oxide synthase inhibitor amino-guanidine (30 mg/kg), or nitric oxide precursor L-arginine (200 mg/kg). After 21 days, the right and left knees of the rats were resected and placed in formalin solution. The samples were histopathologically examined by a blinded evaluator and scored on 8 parameters. Although selective neuronal nitric oxide synthase inhibition exhibited significant (P = 0.044) positive effects on cartilage regeneration following cartilage damage, it was determined that inducible nitric oxide synthase inhibition had no statistically significant effect on cartilage regeneration. It was observed that the nitric oxide synthase activation triggered advanced arthrosis symptoms, such as osteophyte formation. The fact that selective neuronal nitric oxide synthase inhibitors were observed to have mitigating effects on the severity of the damage may, in the future, influence the development of new agents to be used in the treatment of cartilage disorders.

  9. A Comparison of the Effects of Neuronal Nitric Oxide Synthase and Inducible Nitric Oxide Synthase Inhibition on Cartilage Damage

    PubMed Central

    Gokay, Nevzat Selim; Yilmaz, Ibrahim; Demiroz, Ahu Senem; Gokce, Alper; Dervisoglu, Sergülen; Gokay, Banu Vural

    2016-01-01

    The objective of this study was to investigate the effects of selective inducible nitric oxide synthase and neuronal nitric oxide synthase inhibitors on cartilage regeneration. The study involved 27 Wistar rats that were divided into five groups. On Day 1, both knees of 3 rats were resected and placed in a formalin solution as a control group. The remaining 24 rats were separated into 4 groups, and their right knees were surgically damaged. Depending on the groups, the rats were injected with intra-articular normal saline solution, neuronal nitric oxide synthase inhibitor 7-nitroindazole (50 mg/kg), inducible nitric oxide synthase inhibitor amino-guanidine (30 mg/kg), or nitric oxide precursor L-arginine (200 mg/kg). After 21 days, the right and left knees of the rats were resected and placed in formalin solution. The samples were histopathologically examined by a blinded evaluator and scored on 8 parameters. Although selective neuronal nitric oxide synthase inhibition exhibited significant (P = 0.044) positive effects on cartilage regeneration following cartilage damage, it was determined that inducible nitric oxide synthase inhibition had no statistically significant effect on cartilage regeneration. It was observed that the nitric oxide synthase activation triggered advanced arthrosis symptoms, such as osteophyte formation. The fact that selective neuronal nitric oxide synthase inhibitors were observed to have mitigating effects on the severity of the damage may, in the future, influence the development of new agents to be used in the treatment of cartilage disorders. PMID:27382570

  10. Alcoholic beverages and gastric epithelial cell viability: effect on oxidative stress-induced damage.

    PubMed

    Loguercio, C; Tuccillo, C; Federico, A; Fogliano, V; Del Vecchio Blanco, C; Romano, M

    2009-12-01

    Alcohol is known to cause damage to the gastric epithelium independently of gastric acid secretion. Different alcoholic beverages exert different damaging effects in the stomach. However, this has not been systematically evaluated. Moreover, it is not known whether the non-alcoholic components of alcoholic beverages also play a role in the pathogenesis of gastric epithelial cell damage. Therefore, this study was designed to evaluate whether different alcoholic beverages, at a similar ethanol concentration, exerted different damaging effect in gastric epithelial cells in vitro. Moreover, we evaluated whether pre-treatment of gastric epithelial cells with alcoholic beverages prevented oxidative stress-induced damage to gastric cells. Cell damage was assessed, in MKN-28 gastric epithelial cells, by MTT assay. Oxidative stress was induced by incubating cells with xanthine and xanthine oxidase. Gastric cell viability was assessed following 30, 60, and 120 minutes incubation with ethanol 17.5-125 mg/ml(-1) or different alcoholic beverages (i.e., beer, white wine, red wine, spirits) at comparable ethanol concentration. Finally, we assessed whether pre-incubation with red wine (with or without ethanol) prevented oxidative stress-induced cell damage. Red wine caused less damage to gastric epithelial cells in vitro compared with other alcoholic beverages at comparable ethanol concentration. Pre-treatment with red wine, but not with dealcoholate red wine, significantly and time-dependently prevented oxidative stress-induced cell damage. 1) red wine is less harmful to gastric epithelial cells than other alcoholic beverages; 2) this seems related to the non-alcoholic components of red wine, because other alcoholic beverages with comparable ethanol concentration exerted more damage than red wine; 3) red wine prevents oxidative stress-induced cell damage and this seems to be related to its ethanol content.

  11. Cellular and molecular damage of Phanerochaete chrysosporium by the oxidation hair dyes.

    PubMed

    Xiong, Hongxia; Zhou, Qixing

    2012-07-01

    The toxic effect of the oxidation hair dyes on Phanerochaete chrysosporium was investigated by exposure of this fungus in a nitrogen-limited culture medium to various concentrations of the oxidation hair dyes. The results showed that both the size and the dry weight of the mycelial pellets of P. chrysosporium could be reduced when the concentration of the oxidation hair dyes was higher than 300 mg/L. By using the AFLP analysis and the UPGMA dendrogram, the DNA damage of P. chrysosporium by the oxidation hair dyes was also detected. Comparing with that in the control, the percent polymorphism under different concentrations of the oxidation hair dyes increased. In the meantime, the DNA similarity was decreased, which meant that the DNA damage was aggravated with an increase in the concentrations of the oxidation hair dyes. Thus, as an environmental pollutant, the oxidation hair dyes have a toxic effect on P. chrysosporium at both cellular and molecular levels.

  12. Protective effects of curcumin on amyloid-β-induced neuronal oxidative damage.

    PubMed

    Huang, Han-Chang; Chang, Ping; Dai, Xue-Ling; Jiang, Zhao-Feng

    2012-07-01

    To investigate the protective effects of curcumin against amyloid-β (Aβ)-induced neuronal damage. Primary rat cortical neurons were cultured with different treatments of Aβ and curcumin. Neuronal morphologies, viability and damage were assessed. Neuronal oxidative stress was assessed, including extracellular hydrogen peroxide and intracellular reactive oxygen species. The abilities of curcumin to scavenge free radicals and to inhibit Aβ aggregation and β-sheeted formation are further assessed and discussed. Curcumin preserves cell viability, which is decreased by Aβ. The results of changed morphology, released Lactate dehydrogenases and cell viability assays indicate that curcumin protects Aβ-induced neuronal damage. Curcumin depresses Aβ-induced up-regulation of neuronal oxidative stress. The treatment sequence impacts the protective effect of curcumin on Aβ-induced neuronal damage. Curcumin shows a more protective effect on neuronal oxidative damage when curcumin was added into cultured neurons not later than Aβ, especially prior to Aβ. The abilities of curcumin to scavenge free radicals and to inhibit the formation of β-sheeted aggregation are both beneficial to depress Aβ-induced oxidative damage. Curcumin prevents neurons from Aβ-induced oxidative damage, implying the therapeutic usage for the treatment of Alzheimer's disease patients.

  13. The interplay between inflammation, oxidative stress, DNA damage, DNA repair and mitochondrial dysfunction in depression.

    PubMed

    Czarny, Piotr; Wigner, Paulina; Galecki, Piotr; Sliwinski, Tomasz

    2017-06-29

    A growing body of evidence suggests that inflammation, mitochondrial dysfunction and oxidant-antioxidant imbalance may play a significant role in the development and progression of depression. Elevated levels of reactive oxygen and nitrogen species - a result of oxidant-antioxidant imbalance - may lead to increased damage of biomolecules, including DNA. This was confirmed in depressed patients in a research study conducted by our team and other scientists. 8-oxoguanine - a marker of oxidative DNA damage - was found in the patients' lymphocytes, urine and serum. These results were confirmed using a comet assay on lymphocytes. Furthermore, it was shown that the patients' cells repaired peroxide-induced DNA damage less efficiently than controls' cells and that some single nucleotide polymorphisms (SNP) of the genes involved in oxidative DNA damage repair may modulate the risk of depression. Lastly, less efficient DNA damage repair observed in the patients can be, at least partly, attributed to the presence of specific SNP variants, as it was revealed through a genotype-phenotype analysis. In conclusion, the available literature shows that both oxidative stress and less efficient DNA damage repair may lead to increased DNA damage in depressed patients. A similar mechanism may result in mitochondrial dysfunction, which is observed in depression. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Dose-Dependent Protective and Inductive Effects
of Xanthohumol on Oxidative DNA Damage in
Saccharomyces cerevisiae.

    PubMed

    Carvalho, Daniel O; Oliveira, Rui; Johansson, Björn; Guido, Luís F

    2016-03-01

    The effect of xanthohumol, a prenylflavonoid isolated from the hop plant (Humulus lupulus L.), on Saccharomyces cerevisiae DNA oxidative damage and viability was evaluated. Yeast cultures under oxidative stress, induced by H2O2, displayed stronger growth in the presence of 5 mg/L of xanthohumol than cultures with only H2O2. Likewise, DNA damage assessed by the comet assay was significantly lower in cells co-incubated with xanthohumol and H2O2. Accordingly, fluorescence of dichlorofluorescein in cells treated with H2O2 and xanthohumol was considerably lower than in cells exclusively treated with H2O2, indicative of a reactive oxygen species scavenging mechanism and consequent formation of oxidation products, as detected by mass spectrometry. However, at concentrations above 5 mg/L, xanthohumol elicited an opposite effect, leading to a slower growth rate and significant increase in DNA damage. A yeast yap1 deletion mutant strain sensitive to oxidative stress grew more slowly in the presence of at least 5 mg/L of xanthohumol than cultures of the wild type, suggesting that xanthohumol toxicity is mediated by oxidative stress. This evidence provides further insight into the impact of xanthohumol on yeast cells, supporting dose-dependent antioxidant/antigenotoxic and prooxidant/genotoxic effects.

  15. Dose-Dependent Protective and Inductive Effects
of Xanthohumol on Oxidative DNA Damage in
Saccharomyces cerevisiae

    PubMed Central

    Carvalho, Daniel O.; Oliveira, Rui; Johansson, Björn

    2016-01-01

    Summary The effect of xanthohumol, a prenylflavonoid isolated from the hop plant (Humulus lupulus L.), on Saccharomyces cerevisiae DNA oxidative damage and viability was evaluated. Yeast cultures under oxidative stress, induced by H2O2, displayed stronger growth in the presence of 5 mg/L of xanthohumol than cultures with only H2O2. Likewise, DNA damage assessed by the comet assay was significantly lower in cells co-incubated with xanthohumol and H2O2. Accordingly, fluorescence of dichlorofluorescein in cells treated with H2O2 and xanthohumol was considerably lower than in cells exclusively treated with H2O2, indicative of a reactive oxygen species scavenging mechanism and consequent formation of oxidation products, as detected by mass spectrometry. However, at concentrations above 5 mg/L, xanthohumol elicited an opposite effect, leading to a slower growth rate and significant increase in DNA damage. A yeast yap1 deletion mutant strain sensitive to oxidative stress grew more slowly in the presence of at least 5 mg/L of xanthohumol than cultures of the wild type, suggesting that xanthohumol toxicity is mediated by oxidative stress. This evidence provides further insight into the impact of xanthohumol on yeast cells, supporting dose-dependent antioxidant/antigenotoxic and prooxidant/genotoxic effects. PMID:27904394

  16. A FLUORESCENCE BASED ASSAY FOR DNA DAMAGE INDUCED BY STYRENE OXIDE

    EPA Science Inventory

    A rapid and simple assay to detect DNA damage to calf thymus DNA caused by styrene oxide (SO) is reported. This assay is based on changes observed in the melting and annealing behavior of the damaged DNA. The melting annealing process was monitored using a fluorescence indicat...

  17. Metal Oxide Silicon /MOS/ transistors protected from destructive damage by wire

    NASA Technical Reports Server (NTRS)

    Deboo, G. J.; Devine, E. J.

    1966-01-01

    Loop of flexible, small diameter, nickel wire protects metal oxide silicon /MOS/ transistors from a damaging electrostatic potential. The wire is attached to a music-wire spring, slipped over the MOS transistor case, and released so the spring tensions the wire loop around all the transistor leads, shorting them together. This allows handling without danger of damage.

  18. A FLUORESCENCE BASED ASSAY FOR DNA DAMAGE INDUCED BY STYRENE OXIDE

    EPA Science Inventory

    A rapid and simple assay to detect DNA damage to calf thymus DNA caused by styrene oxide (SO) is reported. This assay is based on changes observed in the melting and annealing behavior of the damaged DNA. The melting annealing process was monitored using a fluorescence indicat...

  19. Ascorbic acid protects lipids in human plasma and low-density lipoprotein against oxidative damage

    SciTech Connect

    Frei, B. )

    1991-12-01

    The authors exposed human blood plasma and low-density lipoprotein (LDL) to many different oxidative challenges and followed the temporal consumption of endogenous antioxidants in relation to the initiation of oxidative damage. Under all types of oxidizing conditions, ascorbic acid completely protects lipids in plasma and LDL against detectable peroxidative damage as assessed by a specific and highly sensitive assay for lipid peroxidation. Ascorbic acid proved to be superior to the other water-soluble plasma antioxidants bilirubin, uric acid, and protein thiols as well as to the lipoprotein-associated antioxidants alpha-tocopherol, ubiquinol-10, lycopene, and beta-carotene. Although these antioxidants can lower the rate of detectable lipid peroxidation, they are not able to prevent its initiation. Only ascorbic acid is reactive enough to effectively intercept oxidants in the aqueous phase before they can attack and cause detectable oxidative damage to lipids.

  20. New Paradigms in the Repair of Oxidative Damage in Human Genome

    PubMed Central

    Dutta, Arijit; Yang, Chunying; Sengupta, Shiladitya; Mitra, Sankar; Hegde, Muralidhar L.

    2015-01-01

    Oxidized bases in the mammalian genome, which are invariably mutagenic due to their mis-pairing property, are continuously induced by endogenous reactive oxygen species (ROS) and more abundantly after oxidative stress. Unlike bulky base adducts induced by UV and other environmental mutagens in the genome that block replicative DNA polymerases, oxidatively damaged bases such as 5-hydoxyuracil (5-OHU), produced by oxidative deamination of cytosine in the template strand, do not block replicative polymerases and thus need to be repaired prior to replication in order to prevent mutation. Following up our earlier studies, which showed that the Nei endonuclease VIII like 1 (NEIL1) DNA glycosylase, one of five base excision repair (BER)-initiating enzymes in mammalian cells, has enhanced expression during the S-phase and higher affinity for replication fork-mimicking single-stranded (ss) DNA substrates, we recently provided direct experimental evidence for NEIL1’s role in replicating template-strand repair. The key requirement for this event, which we named as the ‘cow-catcher’ mechanism of pre-replicative BER, is NEIL1’s non-productive binding (substrate binding without product formation) to the lesion base in ss DNA template to stall DNA synthesis, causing fork regression. Repair of the lesion in re-annealed duplex is then carried out by NEIL1 in association with the DNA replication proteins. NEIL1 (and other BER-initiating enzymes) also interact with several accessory and non-canonical proteins including the heterogeneous nuclear ribonucleoprotein U (hnRNP-U) and Y-box-binding protein 1 (YB-1) as well as high mobility group box 1 protein (HMGB1), whose precise roles in BER are still obscure. In this review, we have discussed the recent advances in our understanding of oxidative genome damage repair pathways with particular focus on the pre-replicative template strand repair and the role of scaffold factors like X-ray repair cross-complementing protein 1 (XRCC1

  1. Oxidatively Generated DNA Damage Following Cu(II)-Catalysis of Dopamine and Related Catecholamine Neurotransmitters and Neurotoxins: Role of Reactive Oxygen Species1

    PubMed Central

    Spencer, Wendy A.; Jeyabalan, Jeyaprakash; Kichambre, Sunita; Gupta, Ramesh C.

    2012-01-01

    There is increasing evidence supporting a causal role of oxidatively damaged DNA in neurodegeneration during the natural aging process and neurodegenerative diseases such as Parkinson’s and Alzheimer’s. The presence of redox-active catecholamine neurotransmitters coupled with the localization of catalytic copper to DNA suggests a plausible role for these agents in the induction of oxidatively generated DNA damage. In this study we have investigated the role of Cu(II)-catalyzed oxidation of several catecholamine neurotransmitters and related neurotoxins to induce oxidatively generated DNA damage. Auto-oxidation of all catechol neurotransmitters and related congeners tested resulted in the formation of nearly a dozen oxidation DNA products resulting in a decomposition pattern that was essentially identical for all agents tested. The presence of Cu(II), and to a lesser extent Fe(III), had no effect on the decomposition pattern but substantially enhanced the DNA product levels by up to 75 fold, with dopamine producing the highest levels of unidentified oxidation DNA products (383 ± 46 adducts/106 nucleotides), comparable to 8-oxo-7,8-dihydro-2′-deoxyguanosine levels under the same conditions (122 ± 19 adducts/106 nucleotides). The addition of sodium azide, 2,2,6,6-tetramethyl-4-piperidone, tiron, catalase, bathocuproine or methional to the dopamine/Cu(II) reaction mixture resulted in a substantial decrease (>90%) in oxidation DNA product levels, indicating a role of singlet oxygen, superoxide, H2O2, Cu(I) and Cu(I)OOH in their formation. While the addition of N-tert-butyl-α-phenylnitrone significantly decreased (67%) dopamine-mediated oxidatively damaged DNA, three other hydroxyl radical scavengers, ascorbic acid, sodium benzoate and mannitol, had little to no effect on these oxidation DNA product levels, suggesting that free hydroxyl radicals may have limited involvement in this dopamine/Cu(II)-mediated oxidatively generated DNA damage. These studies suggest

  2. Effects of solutes on damage production and recovery in zirconium

    SciTech Connect

    Zee, R.H.; Birtcher, R.C.; MacEwen, S.R.; Abromeit, C.

    1986-04-01

    Dilute zirconium-based alloys and pure zirconium were irradiated at 10 K with spallation neutrons at IPNS. Four types of alloys - Zr-Ti, Zr-Sn, Zr-Dy and Zr-Au - each with three concentration levels, were used. Low-temperature resistivity damage rates are enhanced by the presence of any of the four solutes. The greatest enhancement was produced by Au while the least by Dy. Within each alloy group, damage production also increased but at a decreasing rate, with increasing concentration. Post-irradiation annealing experiments, up to 400 K, showed that all four solutes suppress recovery due to interstitial migration, indicative of interstitial trapping by the solutes. Vacancy recovery is also suppressed by the presence of Sn, Dy or Au. The effect of Ti is to shift this stage to lower temperature. No clear correlation between the results with solute size was detected.

  3. Roles of hydrogen sulfide and nitric oxide in the alleviation of cadmium-induced oxidative damage in alfalfa seedling roots.

    PubMed

    Li, Le; Wang, Yanqin; Shen, Wenbiao

    2012-06-01

    Despite hydrogen sulfide (H(2)S) and nitric oxide (NO) are important endogenous signals or bioregulators involved in many vital aspects of plant growth and responses against abiotic stresses, little information was known about their interaction. In the present study, we evaluated the effects of H(2)S and NO on alfalfa (Medicago sativa L.) plants exposed to cadmium (Cd) stress. Pretreatment with an H(2)S donor sodium hydrosulfide (NaHS) and well-known NO donor sodium nitroprusside (SNP) decreased the Cd toxicity. This conclusion was supported by the decreases of lipid peroxidation as well as the amelioration of seedling growth inhibition and Cd accumulation, in comparison with the Cd-stressed alone plants. Total activities and corresponding transcripts of antioxidant enzymes, including superoxide dismutase, peroxidase and ascorbate peroxidase were modulated differentially, thus leading to the alleviation of oxidative damage. Effects of H(2)S above were reversed by 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt (cPTIO), the specific scavenger of NO. By using laser confocal scanning microscope combined with Greiss reagent method, further results showed that NO production increased significantly after the NaHS pretreatment regardless of whether Cd was applied or not, all of which were obviously inhibited by cPTIO. These decreases of NO production were consistent with the exaggerated syndromes associated with Cd toxicity. Together, above results suggested that NO was involved in the NaHS-induced alleviation of Cd toxicity in alfalfa seedlings, and also indicated that there exists a cross-talk between H(2)S and NO responsible for the increased abiotic stress tolerance.

  4. The protective effect of magnesium lithospermate B against glucose-induced intracellular oxidative damage

    SciTech Connect

    Qu, Jian; Ren, Xian; Hou, Rui-ying; Dai, Xing-ping; Zhao, Ying-chun; Xu, Xiao-jing; Zhang, Wei; Zhou, Gan; Zhou, Hong-hao; Liu, Zhao-qian

    2011-07-22

    Highlights: {yields} LAB reduced the ROS production in HEK293T cells cultured under oxidative stress. High dose of glucose enhanced the expression of HO-1 mRNA and HO-1 protein in a time-dependent manner. {yields} LAB enhanced the expression of HO-1 mRNA and HO-1 protein in a dose-dependent manner treated with high dose of glucose. {yields} LAB plays an important role against glucose-induced intracellular oxidative damage. {yields} The enhanced expression of HO-1 mRNA and HO-1 protein caused by LAB is regulated via Nrf2 signal pathway. -- Abstract: Objectives: To investigate the effects of magnesium lithospermate B (LAB) on intracellular reactive oxygen species (ROS) production induced by high dose of glucose or H{sub 2}O{sub 2}, we explored the influences of LAB on the expression of heme oxygenase-1 (HO-1) and nuclear factor E2-related factor-2 (Nrf2) in HEK293T cells after treatment with high dose of glucose. Materials and methods: The total nuclear proteins in HEK293T cells were extracted with Cytoplasmic Protein Extraction Kit. The ROS level was determined by flow cytometry. The mRNA and protein expression of HO-1 and Nrf2 were determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot. Results: LAB reduced the ROS production in HEK293T cells cultured under oxidative stress. High dose of glucose enhanced the expression of HO-1 mRNA and HO-1 protein in a time-dependent manner. LAB enhanced the expression of HO-1 mRNA and HO-1 protein in a dose-dependent manner treated with high dose of glucose. The amount of Nrf2 translocation was enhanced after cells were pretreated with 50 {mu}mol/L or 100 {mu}mol/L LAB. Silencing of Nrf2 gene eliminated the enhanced expression of HO-1 protein induced by high dose of glucose plus LAB. Conclusions: LAB plays an important role against glucose-induced intracellular oxidative damage. The enhanced expression of HO-1 mRNA and HO-1 protein caused by LAB is regulated via Nrf2 signal pathway.

  5. Production of pesticide metabolites by oxidative reactions.

    PubMed

    Hodgson, E

    1982-08-01

    The cytochrome P-450-dependent monooxygenase system catalyzes a wide variety of oxidations of pesticide chemicals and related compounds. These reactions include epoxidation and aromatic hydroxylation, aliphatic hydroxylation, O-, N- and S-dealkylation, N-oxidation, oxidative deamination, S-oxidation, P-oxidation, desulfuration and ester cleavage and may result in either detoxication or activation of the pesticide. The current status of such reactions, relative to the production, in vivo, of biologically active intermediates in pesticide metabolism is summarized. More recently we have shown that the FAD-containing monooxygenase of mammalian liver (E.C.1.14.13.8), a xenobiotic metabolizing enzyme of broad specificity formerly known as an amine oxidase, is involved in a variety of pesticide oxidations. These include sulfoxidation of organophosphorus insecticides such as phorate and disulfoton, oxidative desulfuration of phosphonate insecticides such as fonofos and oxidation at the phosphorus atom in such compounds as the cotton defoliant, folex. The relative importance of the FAD-containing monooxygenase vis-a-vis the cytochrome P-450-dependent monooxygenase system is discussed, based on in vitro studies on purified enzymes.

  6. Attenuation of Oxidative Damage by Boerhaavia diffusa L. Against Different Neurotoxic Agents in Rat Brain Homogenate.

    PubMed

    Ayyappan, Prathapan; Palayyan, Salin Raj; Kozhiparambil Gopalan, Raghu

    2016-01-01

    Due to a high rate of oxidative metabolic activity in the brain, intense production of reactive oxygen metabolite occurs, and the subsequent generation of free radicals is implicated in the pathogenesis of traumatic brain injury, epilepsy, and ischemia as well as chronic neurodegenerative diseases. In the present study, protective effects of polyphenol rich ethanolic extract of Boerhaavia diffusa (BDE), a neuroprotective edible medicinal plant against oxidative stress induced by different neurotoxic agents, were evaluated. BDE was tested against quinolinic acid (QA), 3-nitropropionic acid (NPA), sodium nitroprusside (SNP), and Fe (II)/EDTA complex induced oxidative stress in rat brain homogenates. QA, NPA, SNP, and Fe (II)/EDTA treatment caused an increased level of thiobarbituric acid reactive substances (TBARS) in brain homogenates along with a decline in the activities of antioxidant enzymes. BDE treatment significantly decreased the production of TBARS (p < .05) and increased the activities of antioxidant enzymes like catalase and superoxide dismutase along with increased concentration of non-enzymatic antioxidant, reduced glutathione (GSH). Similarly, BDE caused a significant decrease in the lipid peroxidation (LPO) in the cerebral cortex. Inhibitory potential of BDE against deoxyribose degradation (IC50 value 38.91 ± 0.12 μg/ml) shows that BDE can protect hydroxyl radical induced DNA damage in the tissues. Therefore, B. diffusa had high antioxidant potential that could inhibit the oxidative stress induced by different neurotoxic agents in brain. Since many of the neurological disorders are associated with free radical injury, these data may imply that B. diffusa, functioning as an antioxidant agent, may be beneficial for reducing various neurodegenerative complications.

  7. Oxidative damage to DNA constituents by iron-mediated Fenton reactions: the deoxyadenosine family.

    PubMed

    Chattopadhyaya, Rajagopal; Goswami, Bhaswati

    2012-01-01

    The effect of exposing 2'-deoxyadenosine (dA), 5'-dAMP, 3'-dAMP, dApA, dA(pdA)(19,) and poly(dA): oligo(dT) to iron/H(2)O(2) in the presence and absence of ethanol or NADH has been studied. HPLC retention times, enzyme treatments, radio-labeled substrates, UV absorption spectra, and fast atom bombardment mass spectrometry (FABMS) have been used to distinguish 20 products arising from the reaction, of which 16 have been identified and four anomers proposed by comparison with earlier gamma radiation studies. The radical responsible for the reactions seems to be analogous to radiation-derived [Formula: see text], has many products in common, but has some novel ones probably specific for Fenton-induced damage. Two new dimeric adducts arising from the generation of hydroxylamine at N7 and its subsequent condensation with two known sugar damage products, dR-adenine-N1-oxide, and two isomers of dR-FAPy arising from radical attacks at C4 and C5, may be considered novel in the present study. Unlike radiation-derived [Formula: see text], the radical under study is difficult to eliminate due to its generation in the proximity of the substrate molecules. It is proposed that the iron binds to the phosphate group and generates the radical in its vicinity. Strand breaks in dA(pdA)(11) resulting from the Fenton reaction are of two types, spontaneous and alkali-labile. Duplex DNA is less sensitive to attack by this radical, as its various degradation products are a subset of those obtained with monomer substrates and only dR-FAPy production is relatively enhanced for poly (dA): oligo (dT) as compared to those from other substrates.

  8. Experimental Colitis Is Attenuated by Cardioprotective Diet Supplementation That Reduces Oxidative Stress, Inflammation, and Mucosal Damage.

    PubMed

    Vargas Robles, Hilda; Citalán Madrid, Alí Francisco; García Ponce, Alexander; Silva Olivares, Angelica; Shibayama, Mineko; Betanzos, Abigail; Del Valle Mondragón, Leonardo; Nava, Porfirio; Schnoor, Michael

    2016-01-01

    Inflammatory bowel diseases (IBD) such as ulcerative colitis (UC) and Crohn's disease (CD) are multifactorial, relapsing disorders of the gastrointestinal tract. However, the etiology is still poorly understood but involves altered immune responses, epithelial dysfunction, environmental factors, and nutrition. Recently, we have shown that the diet supplement corabion has cardioprotective effects due to reduction of oxidative stress and inflammation. Since oxidative stress and inflammation are also prominent risk factors in IBD, we speculated that corabion also has beneficial effects on experimental colitis. Colitis was induced in male mice by administration of 3.5% (w/v) dextran sulfate sodium (DSS) in drinking water for a period of 3 or 7 days with or without daily gavage feeding of corabion consisting of vitamin C, vitamin E, L-arginine, and eicosapentaenoic and docosahexaenoic acid. We found that corabion administration attenuated DSS-induced colon shortening, tissue damage, and disease activity index during the onset of colitis. Mechanistically, these effects could be explained by reduced neutrophil recruitment, oxidative stress, production of proinflammatory cytokines, and internalization of the junctional proteins ZO-1 and E-cadherin leading to less edema formation. Thus, corabion may be a useful diet supplement for the management of chronic inflammatory intestinal disorders such as IBD.

  9. SIRT3 deacetylates FOXO3 to protect mitochondria against oxidative damage.

    PubMed

    Tseng, Anne H H; Shieh, Shyan-Shu; Wang, Danny Ling

    2013-10-01

    Progressive accumulation of defective mitochondria is a common feature of aged cells. SIRT3 is a NAD(+)-dependent protein deacetylase that regulates mitochondrial function and metabolism in response to caloric restriction and stress. FOXO3 is a direct target of SIRT3 and functions as a forkhead transcription factor to govern diverse cellular responses to stress. Here we show that hydrogen peroxide induces SIRT3 to deacetylate FOXO3 at K271 and K290, followed by the upregulation of a set of genes that are essential for mitochondrial homeostasis (mitochondrial biogenesis, fission/fusion, and mitophagy). Consequently, SIRT3-mediated deacetylation of FOXO3 modulates mitochondrial mass, ATP production, and clearance of defective mitochondria. Thus, mitochondrial quantity and quality are ensured to maintain mitochondrial reserve capacity in response to oxidative damage. Maladaptation to oxidative stress is a major risk factor underlying aging and many aging-related diseases. Hence, our finding that SIRT3 deacetylates FOXO3 to protect mitochondria against oxidative stress provides a possible direction for aging-delaying therapies and disease intervention. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Influence of green tea extract on oxidative damage and apoptosis induced by deltamethrin in rat brain.

    PubMed

    Ogaly, Hanan A; Khalaf, A A; Ibrahim, Marwa A; Galal, Mona K; Abd-Elsalam, Reham M

    2015-01-01

    In the present study, we investigated the protective effect of an aqueous extract of green tea leaves (GTE) against neurotoxicity and oxidative damage induced by deltamethrin (DM) in male rats. Four different groups of rats were used: the 1st group was the vehicle treated control group, the 2nd group received DM (0.6 mg/kg BW), the 3rd group received DM plus GTE, and the 4th received GTE alone (25 mg/kg BW). The brain tissues were collected at the end of the experimental regimen for subsequent investigation. Rats that were given DM had a highly significant elevation in MDA content, nitric oxide concentration, DNA fragmentation and expression level of apoptotic genes, TP53 and COX2. Additionally, a significant reduction in the total antioxidant capacity in the second group was detected. The findings for the 3rd group highlight the efficacy of GTE as a neuro-protectant in DM-induced neurotoxicity through improving the oxidative status and DNA fragmentation as well as suppressing the expression of the TP53 and COX2 genes. In conclusion, GTE, at a concentration of 25mg/kg/day, protected against DM-induced neurotoxicity through its antioxidant and antiapoptotic influence; therefore, it can be used as a protective natural product against DM-induced neurotoxicity.

  11. Experimental Colitis Is Attenuated by Cardioprotective Diet Supplementation That Reduces Oxidative Stress, Inflammation, and Mucosal Damage

    PubMed Central

    Vargas Robles, Hilda; Citalán Madrid, Alí Francisco; García Ponce, Alexander; Silva Olivares, Angelica; Shibayama, Mineko; Betanzos, Abigail; Del Valle Mondragón, Leonardo; Nava, Porfirio; Schnoor, Michael

    2016-01-01

    Inflammatory bowel diseases (IBD) such as ulcerative colitis (UC) and Crohn's disease (CD) are multifactorial, relapsing disorders of the gastrointestinal tract. However, the etiology is still poorly understood but involves altered immune responses, epithelial dysfunction, environmental factors, and nutrition. Recently, we have shown that the diet supplement corabion has cardioprotective effects due to reduction of oxidative stress and inflammation. Since oxidative stress and inflammation are also prominent risk factors in IBD, we speculated that corabion also has beneficial effects on experimental colitis. Colitis was induced in male mice by administration of 3.5% (w/v) dextran sulfate sodium (DSS) in drinking water for a period of 3 or 7 days with or without daily gavage feeding of corabion consisting of vitamin C, vitamin E, L-arginine, and eicosapentaenoic and docosahexaenoic acid. We found that corabion administration attenuated DSS-induced colon shortening, tissue damage, and disease activity index during the onset of colitis. Mechanistically, these effects could be explained by reduced neutrophil recruitment, oxidative stress, production of proinflammatory cytokines, and internalization of the junctional proteins ZO-1 and E-cadherin leading to less edema formation. Thus, corabion may be a useful diet supplement for the management of chronic inflammatory intestinal disorders such as IBD. PMID:26881044

  12. Biscoclaurine alkaloid cepharanthine protects DNA in TK6 lymphoblastoid cells from constitutive oxidative damage

    PubMed Central

    Halicka, H. Dorota; Ita, Masamichi; Tanaka, Toshiki; Kurose, Akira; Darzynkiewicz, Zbigniew

    2008-01-01

    Cepharanthine (CEP), a biscoclaurine (bisbenzylisoquinoline) alkaloid isolated from Stephania cepharantha Hayata, is widely used in Japan to treat variety of diseases. Among a plethora of its biological activities CEP was reported to be able to scavenge radicals and prevent lipid peroxidation. We have recently described the phenomenon of constitutive ATM activation (CAA) and histone H2AX phosphorylation (CHP), the events that report DNA damage induced by endogenously generated radicals, the product of oxidative metabolism in otherwise healthy, untreated cells. The aim of the present study was to explore whether CEP can attenuate the level of CAA and CHP, which would indicate on its ability to protect DNA against endogenous oxidants. The data show that indeed the levels of CAA and CHP in human lymphoblastoid TK6 cells were distinctly lowered upon treatment with CEP. Thus, exposure of cells to 8.3 μM CEP for 4 h led to a reduction of the mean level of CAA and CHP by up to 60% and 50%, respectively. At 1.7 μM CEP the reduction of CAA and CHP after 4 h was 35% and 25%, respectively. Cells exposure to CEP led to a decrease in the level of ondogenous oxidants as measured by the ability to oxidate the fluorescent probe 5-(and-6)-carboxy-2′,7′-dichlorodihydro-fluorescein diacetate. No evidence of apoptosis was seen during the first 8 h of treatment with CEP but initiation of apoptosis (caspase-3 activation) was detected in relatively few (< 10%) cells after exposure to 8.3 μM CEP for 24 h. The data strongly suggest that the scavenging properties of CEP provide a protection of DNA from the radicals generated endogenously during oxidative metabolism. PMID:18276990

  13. Bilirubin oxidation products, oxidative stress, and intracerebral hemorrhage

    PubMed Central

    Clark, J. F.; Loftspring, M.; Wurster, W. L.; Beiler, S.; Beiler, C; Wagner, K. R.; Pyne-Geithman, G. J.

    2009-01-01

    Summary Hematoma and perihematomal regions after intracerebral hemorrhage (ICH) are biochemically active environments known to undergo potent oxidizing reactions. We report facile production of bilirubin oxidation products (BOXes) via hemoglobin/Fenton reaction under conditions approximating putative in vivo conditions seen following ICH. Using a mixture of human hemoglobin, physiological buffers, unconjugated solubilized bilirubin, and molecular oxygen and/or hydrogen peroxide, we generated BOXes, confirmed by spectral signature consistent with known BOXes mixtures produced by independent chemical synthesis, as well as HPLC-MS of BOX A and BOX B. Kinetics are straightforward and uncomplicated, having initial rates around 0.002 μM bilirubin per μM hemoglobin per second under normal experimental conditions. In hematomas from porcine ICH model, we observed significant production of BOXes, malondialdehyde, and superoxide dismutase, indicating a potent oxidizing environment. BOX concentrations increased from 0.084 ± 0.01 in fresh blood to 22.24 ± 4.28 in hematoma at 72 h, and were 11.22 ± 1.90 in adjacent white matter (nmol/g). Similar chemical and analytical results are seen in ICH in vivo, indicating the hematoma is undergoing similar potent oxidations. This is the first report of BOXes production using a well-defined biological reaction and in vivo model of same. Following ICH, amounts of unconjugated bilirubin in hematoma can be substantial, as can levels of iron and hemoglobin. Oxidation of unconjugated bilirubin to yield bioactive molecules, such as BOXes, is an important discovery, expanding the role of bilirubin in pathological processes seen after ICH. PMID:19066073

  14. Oxidative Stress Induces Persistent Telomeric DNA Damage Responsible for Nuclear Morphology Change in Mammalian Cells

    PubMed Central

    Coluzzi, Elisa; Colamartino, Monica; Cozzi, Renata; Leone, Stefano; Meneghini, Carlo; O’Callaghan, Nathan; Sgura, Antonella

    2014-01-01

    One main function of telomeres is to maintain chromosome and genome stability. The rate of telomere shortening can be accelerated significantly by chemical and physical environmental agents. Reactive oxygen species are a source of oxidative stress and can produce modified bases (mainly 8-oxoG) and single strand breaks anywhere in the genome. The high incidence of guanine residues in telomeric DNA sequences makes the telomere a preferred target for oxidative damage. Our aim in this work is to evaluate whether chromosome instability induced by oxidative stress is related specifically to telomeric damage. We treated human primary fibroblasts (MRC-5) in vitro with hydrogen peroxide (100 and 200 µM) for 1 hr and collected data at several time points. To evaluate the persistence of oxidative stress-induced DNA damage up to 24 hrs after treatment, we analysed telomeric and genomic oxidative damage by qPCR and a modified comet assay, respectively. The results demonstrate that the genomic damage is completely repaired, while the telomeric oxidative damage persists. The analysis of telomere length reveals a significant telomere shortening 48 hrs after treatment, leading us to hypothesise that residual telomere damage could be responsible for the telomere shortening observed. Considering the influence of telomere length modulation on genomic stability, we quantified abnormal nuclear morphologies (Nucleoplasmic Bridges, Nuclear Buds and Micronuclei) and observed an increase of chromosome instability in the same time frame as telomere shortening. At subsequent times (72 and 96 hrs), we observed a restoration of telomere length and a reduction of chromosome instability, leaving us to conjecture a correlation between telomere shortening/dysfunction and chromosome instability. We can conclude that oxidative base damage leads to abnormal nuclear morphologies and that telomere dysfunction is an important contributor to this effect. PMID:25354277

  15. Specialty supplement use and biologic measures of oxidative stress and DNA damage

    PubMed Central

    Kantor, Elizabeth D.; Ulrich, Cornelia M.; Owen, Robert W.; Schmezer, Peter; Neuhouser, Marian L.; Lampe, Johanna W.; Peters, Ulrike; Shen, Danny D.; Vaughan, Thomas L.; White, Emily

    2013-01-01

    Background Oxidative stress and resulting cellular damage have been suggested to play a role in the etiology of several chronic diseases, including cancer and cardiovascular disease. Identifying factors associated with reduced oxidative stress and resulting damage may guide future disease-prevention strategies. Methods In the VITamins And Lifestyle (VITAL) biomarker-study of 209 persons living in the Seattle area, we examined the association between current use of several specialty supplements and oxidative stress, DNA damage, and DNA repair capacity. Use of glucosamine, chondroitin, fish oil, methylsulfonylmethane (MSM), co-enzyme Q10 (CoQ10), ginseng, ginkgo, and saw palmetto was ascertained by a supplement inventory/interview, while use of fiber supplements was ascertained by questionnaire. Supplements used by more than 30 persons (glucosamine and chondroitin) were evaluated as the trend across number of pills/week (non-use, <14 pills/week, 14+ pills/week), while less-commonly used supplements were evaluated as use/non-use. Oxidative stress was measured by urinary 8-isoprostane and PGF2α concentrations using enzyme immunoassays (EIA), while lymphocyte DNA damage and DNA repair capacity were measured using the Comet assay. Multivariate-adjusted linear regression was used to model the associations between supplement use and oxidative stress/DNA damage. Results Use of glucosamine (p-trend:0.01), chondroitin (p-trend:0.003), and fiber supplements (p:0.01) was associated with reduced PGF2α concentrations, while CoQ10 supplementation was associated with reduced baseline DNA damage (p:0.003). Conclusions Use of certain specialty supplements may be associated with reduced oxidative stress and DNA damage. Impact Further research is needed to evaluate the association between specialty supplement use and markers of oxidative stress and DNA damage. PMID:23917455

  16. Role of PTEN in Oxidative Stress and DNA Damage in the Liver of Whole-Body Pten Haplodeficient Mice

    PubMed Central

    Bankoglu, Ezgi Eyluel; Tschopp, Oliver; Schmitt, Johannes; Burkard, Philipp; Jahn, Daniel

    2016-01-01

    Type 2 diabetes (T2DM) and obesity are frequently associated with non-alcoholic fatty liver disease (NAFLD) and with an elevated cancer incidence. The molecular mechanisms of carcinogenesis in this context are only partially understood. High blood insulin levels are typical in early T2DM and excessive insulin can cause elevated reactive oxygen species (ROS) production and genomic instability. ROS are important for various cellular functions in signaling and host defense. However, elevated ROS formation is thought to be involved in cancer induction. In the molecular events from insulin receptor binding to genomic damage, some signaling steps have been identified, pointing at the PI3K/AKT pathway. For further elucidation Phosphatase and Tensin homolog (Pten), a tumour suppressor phosphatase that plays a role in insulin signaling by negative regulation of PI3K/AKT and its downstream targets, was investigated here. Dihydroethidium (DHE) staining was used to detect ROS formation in immortalized human hepatocytes. Comet assay and micronucleus test were performed to investigate genomic damage in vitro. In liver samples, DHE staining and western blot detection of HSP70 and HO-1 were performed to evaluate oxidative stress response. DNA double strand breaks (DSBs) were detected by immunohistostaining. Inhibition of PTEN with the pharmacologic inhibitor VO-OHpic resulted in increased ROS production and genomic damage in a liver cell line. Knockdown of Pten in a mouse model yielded increased oxidative stress levels, detected by ROS levels and expression of the two stress-proteins HSP70 and HO-1 and elevated genomic damage in the liver, which was significant in mice fed with a high fat diet. We conclude that PTEN is involved in oxidative stress and genomic damage induction in vitro and that this may also explain the in vivo observations. This further supports the hypothesis that the PI3K/AKT pathway is responsible for damaging effects of high levels of insulin. PMID:27893783

  17. Detection of Strand Cleavage And Oxidation Damage Using Model DNA Molecules Captured in a Nanoscale Pore

    NASA Technical Reports Server (NTRS)

    Vercoutere, W.; Solbrig, A.; DeGuzman, V.; Deamer, D.; Akeson, M.

    2003-01-01

    We use a biological nano-scale pore to distinguish among individual DNA hairpins that differ by a single site of oxidation or a nick in the sugar-phosphate backbone. In earlier work we showed that the protein ion channel alpha-hemolysin can be used as a detector to distinguish single-stranded from double-stranded DNA, single base pair and single nucleotide differences. This resolution is in part a result of sensitivity to structural changes that influence the molecular dynamics of nucleotides within DNA. The strand cleavage products we examined here included a 5-base-pair (5-bp) hairpin with a 5-prime five-nucleotide overhang, and a complementary five-nucleotide oligomer. These produced predictable shoulder-spike and rapid near-full blockade signatures, respectively. When combined, strand annealing was monitored in real time. The residual current level dropped to a lower discrete level in the shoulder-spike blockade signatures, and the duration lengthened. However, these blockade signatures had a shorter duration than the unmodified l0bp hairpin. To test the pore sensitivity to nucleotide oxidation, we examined a 9-bp hairpin with a terminal 8-oxo-deoxyguanosine (8-oxo-dG), or a penultimate 8-oxo-dG. Each produced blockade signatures that differed from the otherwise identical control 9bp hairpins. This study showed that DNA structure is modified sufficiently by strand cleavage or oxidation damage at a single site to alter in a predictable manner the ionic current blockade signatures produced. This technique improves the ability to assess damage to DNA, and can provide a simple means to help characterize the risks of radiation exposure. It may also provide a method to test radiation protection.

  18. Oxidation of ubiquinol by peroxynitrite: implications for protection of mitochondria against nitrosative damage.

    PubMed Central

    Schöpfer, F; Riobó, N; Carreras, M C; Alvarez, B; Radi, R; Boveris, A; Cadenas, E; Poderoso, J J

    2000-01-01

    A major pathway of nitric oxide utilization in mitochondria is its conversion to peroxynitrite, a species involved in biomolecule damage via oxidation, hydroxylation and nitration reactions. In the present study the potential role of mitochondrial ubiquinol in protecting against peroxynitrite-mediated damage is examined and the requirements of the mitochondrial redox status that support this function of ubiquinol are established. (1) Absorption and EPR spectroscopy studies revealed that the reactions involved in the ubiquinol/peroxynitrite interaction were first-order in peroxynitrite and zero-order in ubiquinol, in agreement with the rate-limiting formation of a reactive intermediate formed during the isomerization of peroxynitrite to nitrate. Ubiquinol oxidation occurred in one-electron transfer steps as indicated by the formation of ubisemiquinone. (2) Peroxynitrite promoted, in a concentration-dependent manner, the formation of superoxide anion by mitochondrial membranes. (3) Ubiquinol protected against peroxynitrite-mediated nitration of tyrosine residues in albumin and mitochondrial membranes, as suggested by experimental models, entailing either addition of ubiquinol or expansion of the mitochondrial ubiquinol pool caused by selective inhibitors of complexes III and IV. (4) Increase in membrane-bound ubiquinol partially prevented the loss of mitochondrial respiratory function induced by peroxynitrite. These findings are analysed in terms of the redox transitions of ubiquinone linked to both nitrogen-centred radical scavenging and oxygen-centred radical production. It may be concluded that the reaction of mitochondrial ubiquinol with peroxynitrite is part of a complex regulatory mechanism with implications for mitochondrial function and integrity. PMID:10861208

  19. Therapeutic role of curcumin in oxidative DNA damage caused by formaldehyde.

    PubMed

    Ciftci, Gulay; Aksoy, Abdurrahman; Cenesiz, Sena; Sogut, Mehtap Unlu; Yarim, Gul Fatma; Nisbet, Cevat; Guvenc, Dilek; Ertekin, Ali

    2015-05-01

    Formaldehyde is a common environmental contaminant that causes oxidative DNA damage in cells by increasing the production of reactive oxygen species. The aim of this study was to investigate the amount of 8-hydroxy-deoxyguanosine (8-OhdG), tumor protein 53(TP53), beta-amyloid[Aß(1-42), Aß (1-40)], total antioxidant capacity (TAC) and malondialdehyde (MDA) and the therapeutic role of curcumin in rat cells with oxidative DNA damage caused by formaldehyde. The control group was given physiological saline for 15 days (i.p.) and the second group was given 37% formaldehyde (i.p.) at a dose of 9 mg/kg group every other day. The third group was given 9 mg/kg formaldehyde (i.p.) every other day and treated therapeutically with 100 mg/kg curcumin every day by gavage. At the end of the trial period, urine, blood, and brain tissue was collected from the rats. The levels of MDA in sera were increased and the TAC, TP53, and Aß (1-40) levels were reduced in the formaldehyde-treated group with respect to the control group (p<0.005). After treatment with curcumin, the levels of sera MDA were significantly reduced, the TAC, TP53, and Aß (1-40) levels were significantly increased (P < 0.05). The levels of whole brain Aß (1-42) and 8-OhdG were increased in the formaldehyde-treated group and reduced after treatment with curcumin (P < 0.05). Urinary 8-OhdG excretion increased in the formaldehyde-treated group (P < 0.05) and decreased after treatment with curcumin (P > 0.05). In conclusion, the oxidative stress caused by formaldehyde exposure was reduced with the application of curcumin. © 2015 Wiley Periodicals, Inc.

  20. Anti-oxidant enzyme activities and expression and oxidative damage in patients with non-immediate reactions to drugs

    PubMed Central

    Cornejo-Garcia, J A; Mayorga, C; Torres, M J; Fernandez, T D; R-Pena, R; Bravo, I; Mates, J M; Blanca, M

    2006-01-01

    Adverse drug reactions with an immunological basis (ADRIB) may involve activation of other concomitant, non-specific mechanisms, amplifying the specific response and contributing to the severity and duration. One concomitant mechanism could be the generation of reactive oxygen species (ROS) and/or their detoxification by anti-oxidants, including anti-oxidant enzymes. We analysed the activity of the anti-oxidant enzymes Cu/Zn-superoxide dismutase (SOD), catalase (CAT) and cellular glutathione peroxidase (GPX), as well as certain markers of oxidative damage (thiobarbituric acid reactive substances (TBARS) and carbonyl content) in peripheral blood mononuclear cells from patients with non-immediate ADRIB using spectrophotometric methods and the anti-oxidant enzymes expression by quantitative real-time reverse transcription–polymerase chain reaction. SOD activity and expression were increased in all types of non-immediate reactions (urticaria, maculopapular exanthema and toxic epidermal necrolysis). Regarding oxidative damage, TBARS were increased in urticaria and maculopapular exanthema, and carbonyl groups in all types of reactions. Our observations indicate that oxidative damage occurs in non-immediate reactions. Carbonyl stress and the inadequacy of the anti-oxidant defences are probable causes. PMID:16879248

  1. Anti-oxidant enzyme activities and expression and oxidative damage in patients with non-immediate reactions to drugs.

    PubMed

    Cornejo-Garcia, J A; Mayorga, C; Torres, M J; Fernandez, T D; R-Pena, R; Bravo, I; Mates, J M; Blanca, M

    2006-08-01

    Adverse drug reactions with an immunological basis (ADRIB) may involve activation of other concomitant, non-specific mechanisms, amplifying the specific response and contributing to the severity and duration. One concomitant mechanism could be the generation of reactive oxygen species (ROS) and/or their detoxification by anti-oxidants, including anti-oxidant enzymes. We analysed the activity of the anti-oxidant enzymes Cu/Zn-superoxide dismutase (SOD), catalase (CAT) and cellular glutathione peroxidase (GPX), as well as certain markers of oxidative damage (thiobarbituric acid reactive substances (TBARS) and carbonyl content) in peripheral blood mononuclear cells from patients with non-immediate ADRIB using spectrophotometric methods and the anti-oxidant enzymes expression by quantitative real-time reverse transcription-polymerase chain reaction. SOD activity and expression were increased in all types of non-immediate reactions (urticaria, maculopapular exanthema and toxic epidermal necrolysis). Regarding oxidative damage, TBARS were increased in urticaria and maculopapular exanthema, and carbonyl groups in all types of reactions. Our observations indicate that oxidative damage occurs in non-immediate reactions. Carbonyl stress and the inadequacy of the anti-oxidant defences are probable causes.

  2. Anti-oxidative effects of safranal on immobilization-induced oxidative damage in rat brain.

    PubMed

    Samarghandian, Saeed; Samini, Fariborz; Azimi-Nezhad, Mohsen; Farkhondeh, Tahereh

    2017-09-01

    Safranal, a major constituent of saffron, possesses antioxidant and anti-apoptotic properties showing considerable neuroprotective effects. The present study was designed to investigate the effects of safranal against restraint stress induced oxidative damage in the rat brain. For inducing the chronic restraint stress, rats were kept in the restrainers for 1h every day, for 21 consecutive days, then, the animals received systemic administrations of vehicle (0.1% DMSO) acted as the control group or safranal daily for 21days. Results indicated that the rats submitted to restraint stress showed an increase in the immobility time versus the non-stress rats. In addition, stress decreased number of crossing in the rats submitted to restraint stress versus the non-stress animals. Treatment with safranal (0.75mg/kg) showed a significant reduction in the immobility time compared to the non-treated stress group, while, the treatment improved the number of crossing in rats submitted to restraint stress versus the vehicle-treated stress rats. In the stressed animals that received vehicle, the MDA level was significantly higher and the levels of GSH and antioxidant enzymes were significantly lower than the non-stressed rats. Safranal ameliorated the changes in the stressed animals as compared with the control groups. The present findings indicate that safranal might be effective against depressant-like effects induced by chronic stress via modulating brain oxidative response. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Azoxystrobin causes oxidative stress and DNA damage in the aquatic macrophyte Myriophyllum quitense.

    PubMed

    Garanzini, Daniela S; Menone, Mirta L

    2015-02-01

    Among the search for new types of pesticides, the fungicide azoxystrobin (AZX) was the first patent of the strobilurin compounds, entering in the market in 1996. Its use worldwide is growing, mainly linked to soybean production, although its effects in non-target organisms are almost unknown. The goal of the present work was to evaluate effects of short-term AZX exposure to the aquatic macrophyte Myriophyllum quitense, focusing on oxidative stress parameters and DNA fragmentation. Significant inhibition of the antioxidant enzyme systems were observed at 50 μg/L AZX for catalase and peroxidase (p < 0.05). Lipid and DNA damage were significant at 50 and 100 μg/L AZX. These biomarkers were sensitive to AZX and can be used in a battery to evaluate the occurrence of AZX in freshwater ecosystems.

  4. Effect of low and high temperature anneal on process-induced damage of gate oxide

    SciTech Connect

    King, J.C.; Hu, C. . Dept. of Electrical Engineering and Computer Sciences)

    1994-11-01

    The authors have investigated the ability of high and low temperature anneals to repair the gate oxide damage due to simulated electrical stress caused by wafer charging resulting from plasma etching, etc. Even 800 C anneal cannot restore the stability in interface trap generation. Even 900 C anneal cannot repair the deteriorated charge-to-breakdown and oxide charge trapping. As a small consolation, the ineffectiveness of anneal in repairing the process-induced damage allows them to monitor the damages even at the end of the fabrication process.

  5. Exogenous nitric oxide improves salt tolerance during establishment of Jatropha curcas seedlings by ameliorating oxidative damage and toxic ion accumulation.

    PubMed

    Gadelha, Cibelle Gomes; Miranda, Rafael de Souza; Alencar, Nara Lídia M; Costa, José Hélio; Prisco, José Tarquinio; Gomes-Filho, Enéas

    2017-05-01

    Jatropha curcas is an oilseed species that is considered an excellent alternative energy source for fossil-based fuels for growing in arid and semiarid regions, where salinity is becoming a stringent problem to crop production. Our working hypothesis was that nitric oxide (NO) priming enhances salt tolerance of J. curcas during early seedling development. Under NaCl stress, seedlings arising from NO-treated seeds showed lower accumulation of Na(+) and Cl(-) than those salinized seedlings only, which was consistent with a better growth for all analyzed time points. Also, although salinity promoted a significant increase in hydrogen peroxide (H2O2) content and membrane damage, the harmful effects were less aggressive in NO-primed seedlings. The lower oxidative damage in NO-primed stressed seedlings was attributed to operation of a powerful antioxidant system, including greater glutathione (GSH) and ascorbate (AsA) contents as well as catalase (CAT) and glutathione reductase (GR) enzyme activities in both endosperm and embryo axis. Priming with NO also was found to rapidly up-regulate the JcCAT1, JcCAT2, JcGR1 and JcGR2 gene expression in embryo axis, suggesting that NO-induced salt responses include functional and transcriptional regulations. Thus, NO almost completely abolished the deleterious salinity effects on reserve mobilization and seedling growth. In conclusion, NO priming improves salt tolerance of J. curcas during seedling establishment by inducing an effective antioxidant system and limiting toxic ion and reactive oxygen species (ROS) accumulation. Copyright © 2017 Elsevier GmbH. All rights reserved.

  6. Higher dermal exposure of cashiers to BPA and its association with DNA oxidative damage.

    PubMed

    Lv, Yanshan; Lu, Shaoyou; Dai, Yanyan; Rui, Caiyan; Wang, Yongjun; Zhou, Yuanxiu; Li, Yanru; Pang, Qihua; Fan, Ruifang

    2017-01-01

    Bisphenol A (BPA) is a widely used chemical in the production of many polycarbonate plastics, epoxy resin linings for food and beverage containers and thermal papers. Oral intakes from the contaminated diets were considered as the predominant source of BPA exposure for humans. However, due to the high levels of BPA on thermal receipts and their wide applications in our daily life, the amount of BPA be transferred to the skin after holding thermal paper should not be underestimated, particularly for cashiers. To investigate the contribution of BPA exposure levels via the dermal contact route and the relationship between BPA exposure level and oxidative DNA damage, six male volunteers were recruited and required to simulate the cashiers' work and handle the thermal receipts during the study period. Triclosan (TCS, an antimicrobial compound used widely in personal health and skin care products) was applied as a reference compound. Their urinary BPA, TCS and 8-hydroxy-2'-deoxyguanosine (8-OHdG) concentrations were determined by high performance liquid chromatography/ tandem spectrometer (LC/MS/MS). The results showed that after handling the thermal receipts, the urinary BPA concentrations of volunteers increased 3 times of those before the experimental period. But TCS levels in urine kept stable. There existed a correlation between BPA exposure and 8-OHdG (R(2)=0.237, p<0.001), but not between TCS and 8-OHdG concentrations (R(2)=0.026, p<0.777), indicating that more BPA exposure could lead to higher oxidative DNA damage. That the increases in 8-OHdG levels in urine being almost consistent with those of BPA suggested that handling thermal receipts resulted in the increasing BPA intakes and BPA exposure was correlated with DNA oxidative damage. After 48h of the end of handling thermal receipts, the urinary BPA levels did not descend to the levels before experiment, suggesting that the excretion of BPA via dermal contact was over 48h. BPA exposure through dermal contact

  7. Honey bee (Apis mellifera) drones survive oxidative stress due to increased tolerance instead of avoidance or repair of oxidative damage.

    PubMed

    Li-Byarlay, Hongmei; Huang, Ming Hua; Simone-Finstrom, Michael; Strand, Micheline K; Tarpy, David R; Rueppell, Olav

    2016-10-01

    Oxidative stress can lead to premature aging symptoms and cause acute mortality at higher doses in a range of organisms. Oxidative stress resistance and longevity are mechanistically and phenotypically linked; considerable variation in oxidative stress resistance exists among and within species and typically covaries with life expectancy. However, it is unclear whether stress-resistant, long-lived individuals avoid, repair, or tolerate molecular damage to survive longer than others. The honey bee (Apis mellifera L.) is an emerging model system that is well-suited to address this question. Furthermore, this species is the most economically important pollinator, whose health may be compromised by pesticide exposure, including oxidative stressors. Here, we develop a protocol for inducing oxidative stress in honey bee males (drones) via Paraquat injection. After injection, individuals from different colony sources were kept in common social conditions to monitor their survival compared to saline-injected controls. Oxidative stress was measured in susceptible and resistant individuals. Paraquat drastically reduced survival but individuals varied in their resistance to treatment within and among colony sources. Longer-lived individuals exhibited higher levels of lipid peroxidation than individuals dying early. In contrast, the level of protein carbonylation was not significantly different between the two groups. This first study of oxidative stress in male honey bees suggests that survival of an acute oxidative stressor is due to tolerance, not prevention or repair, of oxidative damage to lipids. It also demonstrates colony differences in oxidative stress resistance that might be useful for breeding stress-resistant honey bees.

  8. The acute toxicity of iron and copper: biomolecule oxidation and oxidative damage in rat liver.

    PubMed

    Boveris, Alberto; Musacco-Sebio, Rosario; Ferrarotti, Nidia; Saporito-Magriñá, Christian; Torti, Horacio; Massot, Francisco; Repetto, Marisa G

    2012-11-01

    The transition metals iron (Fe) and copper (Cu) are needed at low levels for normal health and at higher levels they become toxic for humans and animals. The acute liver toxicity of Fe and Cu was studied in Sprague Dawley male rats (200 g) that received ip 0-60 mg/kg FeCl(2) or 0-30 mg/kg CuSO(4). Dose and time-responses were determined for spontaneous in situ liver chemiluminescence, phospholipid lipoperoxidation, protein oxidation and lipid soluble antioxidants. The doses linearly defined the tissue content of both metals. Liver chemiluminescence increased 4 times and 2 times after Fe and Cu overloads, with half maximal responses at contents (C(50%)) of 110 μgFe/g and 42 μgCu/g liver, and with half maximal time responses (t(1/2)) of 4h for both metals. Phospholipid peroxidation increased 4 and 1.8 times with C(50%) of 118 μg Fe/g and 45 μg Cu/g and with t(1/2) of 7h and 8h. Protein oxidation increased 1.6 times for Fe with C(50%) at 113 μg Fe/g and 1.2 times for Cu with 50 μg Cu/g and t(1/2) of 4h and 5h respectively. The accumulation of Fe and Cu in liver enhanced the rate of free radical reactions and produced oxidative damage. A similar free radical-mediated process, through the formation HO(•) and RO(•) by a Fenton-like homolytic scission of H(2)O(2) and ROOH, seems to operate as the chemical mechanism for the liver toxicity of both metals.

  9. Protective effect of boldine on oxidative mitochondrial damage in streptozotocin-induced diabetic rats.

    PubMed

    Jang, Y Y; Song, J H; Shin, Y K; Han, E S; Lee, C S

    2000-10-01

    Increased oxidative stress has been suggested to be involved in the pathogenesis and progression of diabetic tissue damage. Several antioxidants have been described as beneficial for oxidative stress-associated diseases. Boldine ([s]-2,9-dihydroxy-1, 10-dimethoxyaporphine) is a major alkaloid found in the leaves and bark of boldo (Peumus boldus Molina), and has been shown to possess antioxidant activity and anti-inflammatory effects. From this point of view, the possible anti-diabetic effect of boldine and its mechanism were evaluated. The experiments were performed on male rats divided into four groups: control, boldine (100 mg kg(-1), daily in drinking water), diabetic [single dose of 80 mg kg(-1)of streptozotocin (STZ), i.p.] and diabetic simultaneously fed with boldine for 8 weeks. Diabetic status was evaluated periodically with changes of plasma glucose levels and body weight in rats. The effect of boldine on the STZ-induced diabetic rats was examined with the formation of malondialdehydes and carbonyls and the activities of endogenous antioxidant enzymes (superoxide dismutase and glutathione peroxidase) in mitochondria of the pancreas, kidney and liver. The scavenging action of boldine on oxygen free radicals and the effect on mitochondrial free-radical production were also investigated. The treatment of boldine attenuated the development of hyperglycemia and weight loss induced by STZ injection in rats. The levels of malondialdehyde (MDA) and carbonyls in liver, kidney and pancreas mitochondria were significantly increased in STZ-treated rats and decreased after boldine administration. The activities of mitochondrial manganese superoxide dismutase (MnSOD) in the liver, pancreas and kidney were significantly elevated in STZ-treated rats. Boldine administration decreased STZ-induced elevation of MnSOD activity in kidney and pancreas mitochondria, but not in liver mitochondria. In the STZ-treated group, glutathione peroxidase activities decreased in liver

  10. Pre-fledgling oxidative damage predicts recruitment in a long-lived bird

    PubMed Central

    Noguera, José Carlos; Kim, Sin-Yeon; Velando, Alberto

    2012-01-01

    Empirical evidence has shown that stressful conditions experienced during development may exert long-term negative effects on life-history traits. Although it has been suggested that oxidative stress has long-term effects, little is known about delayed consequences of oxidative stress experienced early in life in fitness-related traits. Here, we tested whether oxidative stress during development has long-term effects on a life-history trait directly related to fitness in three colonies of European shags Phalacrocorax aristotelis. Our results revealed that recruitment probability decreased with oxidative damage during the nestling period; oxidative damage, in turn, was related to the level of antioxidant capacity. Our results suggest a link between oxidative stress during development and survival to adulthood, a key element of population dynamics. PMID:21865247

  11. Perinatal tobacco smoke exposure increases vascular oxidative stress and mitochondrial damage in non-human primates.

    PubMed

    Westbrook, David G; Anderson, Peter G; Pinkerton, Kent E; Ballinger, Scott W

    2010-09-01

    Epidemiological studies suggest that events occurring during fetal and early childhood development influence disease susceptibility. Similarly, molecular studies in mice have shown that in utero exposure to cardiovascular disease (CVD) risk factors such as environmental tobacco smoke (ETS) increased adult atherogenic susceptibility and mitochondrial damage; however, the molecular effects of similar exposures in primates are not yet known. To determine whether perinatal ETS exposure increased mitochondrial damage, dysfunction and oxidant stress in primates, archived tissues from the non-human primate model Macaca mulatta (M. mulatta) were utilized. M. mulatta were exposed to low levels of ETS (1 mg/m(3) total suspended particulates) from gestation (day 40) to early childhood (1 year), and aortic tissues were assessed for oxidized proteins (protein carbonyls), antioxidant activity (SOD), mitochondrial function (cytochrome oxidase), and mitochondrial damage (mitochondrial DNA damage). Results revealed that perinatal ETS exposure resulted in significantly increased oxidative stress, mitochondrial dysfunction and damage which were accompanied by significantly decreased mitochondrial antioxidant capacity and mitochondrial copy number in vascular tissue. Increased mitochondrial damage was also detected in buffy coat tissues in exposed M. mulatta. These studies suggest that perinatal tobacco smoke exposure increases vascular oxidative stress and mitochondrial damage in primates, potentially increasing adult disease susceptibility.

  12. Protective Effects of Gelam Honey against Oxidative Damage in Young and Aged Rats

    PubMed Central

    Sahhugi, Zulaikha; Jubri, Zakiah

    2014-01-01

    Aging is characterized by progressive decline in physiological and body function due to increase in oxidative damage. Gelam honey has been accounted to have high phenolic and nonphenolic content to attenuate oxidative damage. This study was to determine the effect of local gelam honey on oxidative damage of aged rats. Twenty-four male Spraque-Dawley rats were divided into young (2 months) and aged (19 months) groups. Each group was further divided into control (fed with plain water) and supplemented with 2.5 mg/kg body weight of gelam honey for 8 months. DNA damage level was determined by comet assay and plasma malondialdehyde (MDA) by high performance liquid chromatography (HPLC). The activity of blood and cardiac antioxidant enzymes was determined by spectrophotometer. The DNA damage and MDA level were reduced in both gelam honey supplemented groups. Gelam honey increases erythrocytes CAT and cardiac SOD activities in young and cardiac CAT activity in young and aged groups. The DNA damage was increased in the aged group compared to young group, but reduced at the end of the study. The decline of oxidative damage in rats supplemented with gelam honey might be through the modulation of antioxidant enzyme activities. PMID:25505937

  13. Protective effects of gelam honey against oxidative damage in young and aged rats.

    PubMed

    Sahhugi, Zulaikha; Hasenan, Siti Maisarah; Jubri, Zakiah

    2014-01-01

    Aging is characterized by progressive decline in physiological and body function due to increase in oxidative damage. Gelam honey has been accounted to have high phenolic and nonphenolic content to attenuate oxidative damage. This study was to determine the effect of local gelam honey on oxidative damage of aged rats. Twenty-four male Spraque-Dawley rats were divided into young (2 months) and aged (19 months) groups. Each group was further divided into control (fed with plain water) and supplemented with 2.5 mg/kg body weight of gelam honey for 8 months. DNA damage level was determined by comet assay and plasma malondialdehyde (MDA) by high performance liquid chromatography (HPLC). The activity of blood and cardiac antioxidant enzymes was determined by spectrophotometer. The DNA damage and MDA level were reduced in both gelam honey supplemented groups. Gelam honey increases erythrocytes CAT and cardiac SOD activities in young and cardiac CAT activity in young and aged groups. The DNA damage was increased in the aged group compared to young group, but reduced at the end of the study. The decline of oxidative damage in rats supplemented with gelam honey might be through the modulation of antioxidant enzyme activities.

  14. Therapeutic Hypothermia Reduces Oxidative Damage and Alters Antioxidant Defenses after Cardiac Arrest

    PubMed Central

    Hackenhaar, Fernanda S.; Medeiros, Tássia M.; Heemann, Fernanda M.; Behling, Camile S.; Putti, Jordana S.; Mahl, Camila D.; Verona, Cleber; da Silva, Ana Carolina A.; Guerra, Maria C.; Gonçalves, Carlos A. S.; Oliveira, Vanessa M.; Riveiro, Diego F. M.; Vieira, Silvia R. R.

    2017-01-01

    After cardiac arrest, organ damage consequent to ischemia-reperfusion has been attributed to oxidative stress. Mild therapeutic hypothermia has been applied to reduce this damage, and it may reduce oxidative damage as well. This study aimed to compare oxidative damage and antioxidant defenses in patients treated with controlled normothermia versus mild therapeutic hypothermia during postcardiac arrest syndrome. The sample consisted of 31 patients under controlled normothermia (36°C) and 11 patients treated with 24 h mild therapeutic hypothermia (33°C), victims of in- or out-of-hospital cardiac arrest. Parameters were assessed at 6, 12, 36, and 72 h after cardiac arrest in the central venous blood samples. Hypothermic and normothermic patients had similar S100B levels, a biomarker of brain injury. Xanthine oxidase activity is similar between hypothermic and normothermic patients; however, it decreases posthypothermia treatment. Xanthine oxidase activity is positively correlated with lactate and S100B and inversely correlated with pH, calcium, and sodium levels. Hypothermia reduces malondialdehyde and protein carbonyl levels, markers of oxidative damage. Concomitantly, hypothermia increases the activity of erythrocyte antioxidant enzymes superoxide dismutase, glutathione peroxidase, and glutathione S-transferase while decreasing the activity of serum paraoxonase-1. These findings suggest that mild therapeutic hypothermia reduces oxidative damage and alters antioxidant defenses in postcardiac arrest patients. PMID:28553435

  15. N-Acetylcysteine supplementation reduces oxidative stress and DNA damage in children with β-thalassemia.

    PubMed

    Ozdemir, Zeynep Canan; Koc, Ahmet; Aycicek, Ali; Kocyigit, Abdurrahim

    2014-01-01

    There are several reports that increased oxidative stress and DNA damage were found in β-thalassemia major (β-TM) patients. In this study, we aimed to evaluate the effects of N-acetylcysteine (NAC) and vitamin E on total oxidative stress and DNA damage in children with β-TM. Seventy-five children with transfusion-dependent β-thalassemia (β-thal) were randomly chosen to receive 10 mg/kg/day of NAC or 10 IU/kg/day of vitamin E or no supplementation; 28 healthy controls were also included in the study. Serum total oxidant status (TOS) and total antioxidant capacity (TAC) were measured, oxidative stress index (OSI) was calculated, and mononuclear DNA damage was assessed by alkaline comet assay; they were determined before treatment and after 3 months of treatment. Total oxydent status, OSI, and DNA damage levels were significantly higher and TAC levels were significantly lower in the thalassemic children than in the healthy controls (p < 0.001). In both supplemented groups, mean TOS and OSI levels were decreased; TAC and pre transfusion hemoglobin (Hb) levels were significantly increased after 3 months (p ≤ 0.002). In the NAC group, DNA damage score decreased (p = 0.001). N-Acetylcysteine and vitamin E may be effective in reducing serum oxidative stress and increase pre transfusion Hb levels in children with β-thal. N-Acetylcysteine also can reduce DNA damage.

  16. A Topical Mitochondria-Targeted Redox-Cycling Nitroxide Mitigates Oxidative Stress-Induced Skin Damage.

    PubMed

    Brand, Rhonda M; Epperly, Michael W; Stottlemyer, J Mark; Skoda, Erin M; Gao, Xiang; Li, Song; Huq, Saiful; Wipf, Peter; Kagan, Valerian E; Greenberger, Joel S; Falo, Louis D

    2017-03-01

    Skin is the largest human organ, and it provides a first line of defense that includes physical, chemical, and immune mechanisms to combat environmental stress. Radiation is a prevalent environmental stressor. Radiation-induced skin damage ranges from photoaging and cutaneous carcinogenesis caused by UV exposure, to treatment-limiting radiation dermatitis associated with radiotherapy, to cutaneous radiation syndrome, a frequently fatal consequence of exposures from nuclear accidents. The major mechanism of skin injury common to these exposures is radiation-induced oxidative stress. Efforts to prevent or mitigate radiation damage have included development of antioxidants capable of reducing reactive oxygen species. Mitochondria are particularly susceptible to oxidative stress, and mitochondrial-dependent apoptosis plays a major role in radiation-induced tissue damage. We reasoned that targeting a redox cycling nitroxide to mitochondria could prevent reactive oxygen species accumulation, limiting downstream oxidative damage and preserving mitochondrial function. Here we show that in both mouse and human skin, topical application of a mitochondrially targeted antioxidant prevents and mitigates radiation-induced skin damage characterized by clinical dermatitis, loss of barrier function, inflammation, and fibrosis. Further, damage mitigation is associated with reduced apoptosis, preservation of the skin's antioxidant capacity, and reduction of irreversible DNA and protein oxidation associated with oxidative stress. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  17. Oxidative damage to the promoter region of SQSTM1/p62 is common to neurodegenerative disease

    PubMed Central

    Du, Yifeng; Wooten, Michael C; Wooten, Marie W.

    2009-01-01

    Recently we reported that declined SQSTM1/p62 expression in Alzheimer disease brain was age-correlated with oxidative damage to the p62 promoter. The objective of this study was to examine whether oxidative damage to the p62 promoter is common to DNA recovered from brain of individuals with neurodegenerative disease. Increased 8-OHdG staining was observed in brain sections from Alzheimer’s disease (AD), Parkinson disease (PD), Huntington disease (HD), Frontotemporal dementia (FTD), and Pick’s disease compared to control subjects. In parallel, the p62 promoter exhibited elevated oxidative damage in samples from various diseases compared to normal brain, and damage was negatively correlated with p62 expression in FTD samples. Oxidative damage to the p62 promoter induced by H2O2 treatment decreased its transcriptional activity. In keeping with this observation, the transcriptional activity of a Sp-1 element deletion mutant displayed reduced stimulus-induced activity. These findings reveal that oxidative damage to the p62 promoter decreased its transcriptional activity and might therefore account for decreased expression of p62. Altogether these results suggest that pharmacological means to increase p62 expression may be beneficial in delaying the onset of neurodegeneration. PMID:19481605

  18. Oxidative damage induced by copper in mouse primary hepatocytes by single-cell analysis.

    PubMed

    Jing, Mingyang; Liu, Yang; Song, Wei; Yan, Yunxing; Yan, Wenbao; Liu, Rutao

    2016-01-01

    Copper can disturb the intracellular redox balance, induce oxidative stress, and subsequently cause irreversible damage, leading to a variety of diseases. In the present study, mouse primary hepatocytes were chosen to elucidate the in vitro oxidative damage of short-term copper exposure (10-200 μM) by single-cell analysis. We evaluated the toxicity of copper by reactive oxygen species (ROS), glutathione (GSH), and oxidative DNA damage at the single-cell level. Oxidative damage induced by copper was verified by the morphological changes, persistent elevations of excessive ROS and malondialdehyde (MDA), a decrease in GSH level, and the oxidative DNA damage. Furthermore, the average ROS generation, GSH consumption, and the indicators in DNA damage did not significantly change at relatively low concentrations (10 or 50 μM), but we can find the alterations of parameters in some single cells clearly. Emphasis on the analysis of single cells is conducive to gain a better understanding on the toxicity of copper. This study will also complement studies on the environmental risk assessment of copper pollution.

  19. Effects of Hydrogen Peroxide on Wound Healing in Mice in Relation to Oxidative Damage

    PubMed Central

    Ho, Rongjian; Wasser, Martin; Du, Tiehua; Ng, Wee Thong; Halliwell, Barry

    2012-01-01

    It has been established that low concentrations of hydrogen peroxide (H2O2) are produced in wounds and is required for optimal healing. Yet at the same time, there is evidence that excessive oxidative damage is correlated with poor-healing wounds. In this paper, we seek to determine whether topical application of H2O2 can modulate wound healing and if its effects are related to oxidative damage. Using a C57BL/6 mice excision wound model, H2O2 was found to enhance angiogenesis and wound closure at 10 mM but retarded wound closure at 166 mM. The delay in closure was also associated with decreased connective tissue formation, increased MMP-8 and persistent neutrophil infiltration. Wounding was found to increase oxidative lipid damage, as measured by F2-isoprostanes, and nitrative protein damage, as measured by 3-nitrotyrosine. However H2O2 treatment did not significantly increase oxidative and nitrative damage even at concentrations that delay wound healing. Hence the detrimental effects of H2O2 may not involve oxidative damage to the target molecules studied. PMID:23152875

  20. [Preventive measures against health damage due to chemicals in household products].

    PubMed

    Kaniwa, Masa-aki

    2010-01-01

    Chemicals in household products have been paid much attention as the main cause of health damage in consumers, such as allergic contact dermatitis. Preventive measures against health damage due to chemicals in fabrics, plastics and rubber products for household use, are reviewed, focusing on 1) the incidence of health damage due to household products, 2) causative product-chemical investigation, and 3) case studies on skin damage.

  1. LC-MS/MS Analysis and Comparison of Oxidative Damages on Peptides Induced by Pathogen Reduction Technologies for Platelets

    NASA Astrophysics Data System (ADS)

    Prudent, Michel; Sonego, Giona; Abonnenc, Mélanie; Tissot, Jean-Daniel; Lion, Niels

    2014-04-01

    Pathogen reduction technologies (PRT) are photochemical processes that use a combination of photosensitizers and UV-light to inactivate pathogens in platelet concentrates (PCs), a blood-derived product used to prevent hemorrhage. However, different studies have questioned the impact of PRT on platelet function and transfusion efficacy, and several proteomic analyses revealed possible oxidative damages to proteins. The present work focused on the oxidative damages produced by the two main PRT on peptides. Model peptides containing residues prone to oxidation (tyrosine, histidine, tryptophane, and cysteine) were irradiated with a combination of amotosalen/UVA (Intercept process) or riboflavin/UVB (Mirasol-like process). Modifications were identified and quantified by liquid chromatography coupled to tandem mass spectrometry. Cysteine-containing peptides formed disulfide bridges (R-SS-R, -2 Da; favored following amotosalen/UVA), sulfenic and sulfonic acids (R-SOH, +16 Da, R-SO3H, +48 Da, favored following riboflavin/UVB) upon treatment and the other amino acids exhibited different oxidations revealed by mass shifts from +4 to +34 Da involving different mechanisms; no photoadducts were detected. These amino acids were not equally affected by the PRT and the combination riboflavin/UVB generated more oxidation than amotosalen/UVA. This work identifies the different types and sites of peptide oxidations under the photochemical treatments and demonstrates that the two PRT may behave differently. The potential impact on proteins and platelet functions may thus be PRT-dependent.

  2. Effect of Tai Chi exercise on DNA damage, antioxidant enzymes, and oxidative stress in middle-age adults.

    PubMed

    Goon, J A; Aini, A H Noor; Musalmah, M; Anum, M Y Yasmin; Nazaimoon, W M Wan; Ngah, W Z Wan

    2009-01-01

    The biochemical mechanisms involving oxidative stress to explain the relationship between exercise and healthy aging are still unclear. Tai Chi participants and matched sedentary volunteers age 45 and above were enrolled. Glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) activities; levels of DNA damage using the comet assay; and malondialdehyde (MDA) and advanced glycation end products (AGE) were determined at 0, 6, and 12 months. Tai Chi subjects had decreased normal and increased mildly damaged DNA with elevated GPx activity after 6 months (n=25). Plasma MDA and AGE concentrations decreased significantly after 12 months (n=15) accompanied by increased SOD activity. This may be attributed to the hormesis effect, whereby mild induction of oxidative stress at the first 6 months of exercise resulted in stimulation of antioxidant defenses. These parameters were unchanged in the sedentary subjects in the first 6 months (n=27) except for elevated SOD activity. After 12 months, the sedentary subjects (n=17) had decreased normal DNA and increased severely damaged DNA with unaltered MDA and AGE levels while SOD and GPx activities were significantly elevated. Regular Tai Chi exercise stimulated endogenous antioxidant enzymes and reduced oxidative damage markers.

  3. The effect of thalidomide on ethanol-induced gastric mucosal damage in mice: involvement of inflammatory cytokines and nitric oxide.

    PubMed

    Amirshahrokhi, Keyvan; Khalili, Ali-Reza

    2015-01-05

    Excessive ethanol ingestion causes gastric mucosal damage through the inflammatory and oxidative processes. The present study was aimed to evaluate the protective effect of thalidomide on ethanol-induced gastric mucosal damage in mice. The animals were pretreated with vehicle or thalidomide (30 or 60 mg/kg, orally), and one hour later, the gastric mucosal injury was induced by oral administration of acidified ethanol. The animals were euthanized one hour after ethanol ingestion, and gastric tissues were collected to biochemical analyzes. The gastric mucosal lesions were assessed by macroscopic and histopathological examinations. The results showed that treatment of mice with thalidomide prior to the administration of ethanol dose-dependently reduced the gastric ulcer index. Thalidomide pretreatment significantly reduced the levels of pro-inflammatory cytokines [tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6], malondialdehyde (MDA) and myeloperoxidase (MPO) activity. In addition, thalidomide significantly inhibited ethanol-induced nitric oxide (NO) overproduction in gastric tissue. Histological observations showed that ethanol-induced gastric mucosal damage was attenuated by thalidomide pretreatment. It seems that thalidomide as an anti-inflammatory agent may have a protective effect against alcohol-induced mucosal damage by inhibition of neutrophil infiltration and reducing the production of nitric oxide and inflammatory cytokines in gastric tissue.

  4. DNA oxidation in anionic reverse micelles: ruthenium-mediated damage at Guanine in single- and double-stranded DNA.

    PubMed

    Evans, Sarah E; Mon, Soe; Singh, Robinder; Ryzhkov, Lev R; Szalai, Veronika A

    2006-04-03

    One-electron guanine oxidation in DNA has been investigated in anionic reverse micelles (RMs). A photochemical method for generating Ru3+ from the ruthenium polypyridyl complex tris(2-2'-bipyridine)ruthenium(II) chloride ([Ru(bpy)3]Cl2) is combined with high-resolution polyacrylamide gel electrophoresis (PAGE) to quantify piperidine-labile guanine oxidation products. As characterized by emission spectroscopy of Ru(bpy)3(2+), the addition of DNA to RMs containing Ru(bpy)3(2+) does not perturb the environment of Ru(bpy)3(2+). The steady-state quenching efficiency of Ru(bpy)3(2+) with K3[Fe(CN)6] in buffer solution is approximately 2-fold higher than that observed in RMs. Consistent with the difference in quenching efficiency in the two media, a 1.5-fold higher yield of piperidine-labile damage products as monitored by PAGE is observed for duplex oligonucleotide in buffer vs RMs. In contrast, a 13-fold difference in the yield of PAGE-detected G oxidation products is observed when single-stranded DNA is the substrate. Circular dichroism spectra showed that single-stranded DNA undergoes a structural change in anionic RMs. This structural change is potentially due to cation-mediated adsorption of the DNA phosphates on the anionic headgroups of the RMs, leading to protection of the guanine from oxidatively generated damage.

  5. A modified alkaline Comet assay for in vivo detection of oxidative DNA damage in Drosophila melanogaster.

    PubMed

    Shukla, A K; Pragya, P; Chowdhuri, D Kar

    2011-12-24

    Modifications to the alkaline Comet assay by using lesion-specific endonucleases, such as formamidopyrimidine-DNA glycosylase (FPG) and endonuclease III (ENDOIII, also known as Nth), can detect DNA bases with oxidative damage. This modified assay can be used to assess the genotoxic/carcinogenic potential of environmental chemicals. The goal of this study was to validate the ability of this modified assay to detect oxidative stress-induced genotoxicity in Drosophila melanogaster (Oregon R(+)). In this study, we used three well known chemical oxidative stress inducers: hydrogen peroxide (H(2)O(2)), cadmium chloride (CdCl(2)) and copper sulfate (CuSO(4)). Third instar larvae of D. melanogaster were fed various concentrations of the test chemicals (50-200μM) mixed with a standard Drosophila food for 24h. Alkaline Comet assays with and without the FPG and ENDOIII enzymes were performed with midgut cells that were isolated from the control and treated larvae. Our results show a concentration-dependent increase (p<0.05-0.001) in the migration of DNA from the treated larvae. ENDOIII treatment detected more oxidative DNA damage (specifically pyrimidine damage) in the H(2)O(2) exposed larvae compared to FPG or no enzyme treatment (buffer only). In contrast, FPG treatment detected more oxidative DNA damage (specifically purine damage) in CuSO(4) exposed larvae compared to ENDOIII. Although previously reported to be a potent genotoxic agent, CdCl(2) did not induce more oxidative DNA damage than the other test chemicals. Our results show that the modified alkaline Comet assay can be used to detect oxidative stress-induced DNA damage in D. melanogaster and thus may be applicable for in vivo genotoxic assessments of environmental chemicals.

  6. Melatonin reduces oxidant damage and promotes mitochondrial respiration: implications for aging.

    PubMed

    Reiter, Russel J; Tan, Dun Xian; Manchester, Lucien C; El-Sawi, Mamdouh R

    2002-04-01

    Melatonin has a number of properties as a consequence of which it could be beneficial to animals as they age. Of particular interest are its ubiquitous actions as a direct and indirect antioxidant and free radical scavenger. Besides directly detoxifying a variety of reactive oxygen and reactive nitrogen species, at least one product that is formed as a result of these interactions is also a potent free radical scavenger. Thus, the product that is formed when melatonin detoxifies hydrogen peroxide, that is, N1-acetyl-N2-formyl-5-methoxykynuramine is an efficient scavenger, at least equivalent to melatonin itself. This antioxidant cascade increases the ability of melatonin to resist oxidative damage. Other actions of melatonin, such as stimulation of antioxidative enzymes also improves its status as an antioxidant. Finally, recent observations documenting melatonin's ability to stimulate electron transport and ATP production in the inner-mitochondrial membrane also has relevance for melatonin as an agent that could alter processes of aging. These findings, coupled with diminished melatonin production in advanced age, has prompted scientists to consider melatonin in the context of aging. As of this writing there is no definitive evidence to prove that melatonin alters the rate of aging, although data relating to melatonin deferring some age-related degenerative conditions is accumulating rapidly.

  7. Microglial Hv1 proton channel promotes cuprizone-induced demyelination through oxidative damage.

    PubMed

    Liu, Junli; Tian, Daishi; Murugan, Madhuvika; Eyo, Ukpong B; Dreyfus, Cheryl F; Wang, Wei; Wu, Long-Jun

    2015-10-01

    NADPH oxidase (NOX)-dependent reactive oxygen species (ROS) production in inflammatory cells including microglia plays an important role in demyelination and free radical-mediated tissue injury in multiple sclerosis (MS). However, the mechanism underlying microglial ROS production and demyelination remains largely unknown. The voltage-gated proton channel, Hv1, is selectively expressed in microglia and is required for NOX-dependent ROS generation in the brain. In the present study, we sought to determine the role of microglial Hv1 proton channels in a mouse model of cuprizone-induced demyelination, a model for MS. Following cuprizone exposure, wild-type mice presented obvious demyelination, decreased myelin basic protein expression, loss of mature oligodendrocytes, and impaired motor coordination in comparison to mice on a normal chow diet. However, mice lacking Hv1 (Hv1(-/-) ) are partially protected from demyelination and motor deficits compared with those in wild-type mice. These rescued phenotypes in Hv1(-/-) mice in cuprizone-induced demyelination is accompanied by reduced ROS production, ameliorated microglial activation, increased oligodendrocyte progenitor cell (NG2) proliferation, and increased number of mature oligodendrocytes. These results demonstrate that the Hv1 proton channel is required for cuprizone-induced microglial oxidative damage and subsequent demyelination. Our study suggests that the microglial Hv1 proton channel is a unique target for controlling NOX-dependent ROS production in the pathogenesis of MS.

  8. Differential protection by nitroxides and hydroxylamines to radiation-induced and metal ion-catalyzed oxidative damage.

    PubMed

    Xavier, Sandhya; Yamada, Ken-ichi; Samuni, Ayelet M; Samuni, Amram; DeGraff, William; Krishna, Murali C; Mitchell, James B

    2002-11-14

    Modulation of radiation- and metal ion-catalyzed oxidative-induced damage using plasmid DNA, genomic DNA, and cell survival, by three nitroxides and their corresponding hydroxylamines, were examined. The antioxidant property of each compound was independently determined by reacting supercoiled DNA with copper II/1,10-phenanthroline complex fueled by the products of hypoxanthine/xanthine oxidase (HX/XO) and noting the protective effect as assessed by agarose gel electrophoresis. The nitroxides and their corresponding hydroxylamines protected approximately to the same degree (33-47% relaxed form) when compared to 76.7% relaxed form in the absence of protectors. Likewise, protection by both the nitroxide and corresponding hydroxylamine were observed for Chinese hamster V79 cells exposed to hydrogen peroxide. In contrast, when plasmid DNA damage was induced by ionizing radiation (100 Gy), only nitroxides (10 mM) provide protection (32.4-38.5% relaxed form) when compared to radiation alone or in the presence of hydroxylamines (10 mM) (79.8% relaxed form). Nitroxide protection was concentration dependent. Radiation cell survival studies and DNA double-strand break (DBS) assessment (pulse field electrophoresis) showed that only the nitroxide protected or prevented damage, respectively. Collectively, the results show that nitroxides and hydroxylamines protect equally against the damage mediated by oxidants generated by the metal ion-catalyzed Haber-Weiss reaction, but only nitroxides protect against radiation damage, suggesting that nitroxides may more readily react with intermediate radical species produced by radiation than hydroxylamines.

  9. Prenatal exposure to testosterone impairs oxidative damage repair efficiency in the domestic chicken (Gallus gallus).

    PubMed

    Treidel, L A; Whitley, B N; Benowitz-Fredericks, Z M; Haussmann, M F

    2013-10-23

    Elevated levels of maternal androgens in avian eggs affect numerous traits, including oxidative stress. However, current studies disagree as to whether prenatal androgen exposure enhances or ameliorates oxidative stress. Here, we tested how prenatal testosterone exposure affects oxidative stress in female domestic chickens (Gallus gallus) during the known oxidative challenge of an acute stressor. Prior to incubation, eggs were either injected with an oil vehicle or 5 ng testosterone. At either 17 or 18 days post-hatch, several oxidative stress markers were assessed from blood taken before and after a 20 min acute stressor, as well as following a 25 min recovery from the stressor. We found that, regardless of yolk treatment, during both stress and recovery all individuals were in a state of oxidative stress, with elevated levels of oxidative damage markers accompanied by a reduced total antioxidant capacity. In addition, testosterone-exposed individuals exhibited poorer DNA damage repair efficiencies in comparison with control individuals. Our work suggests that while yolk androgens do not alter oxidative stress directly, they may impair mechanisms of oxidative damage repair.

  10. Dexamethasone and 1,25-dihydroxyvitamin D3 reduce oxidative stress-related DNA damage in differentiating osteoblasts.

    PubMed

    Pawlowska, Elzbieta; Wysokiński, Daniel; Tokarz, Paulina; Piastowska-Ciesielska, Agnieszka; Szczepanska, Joanna; Blasiak, Janusz

    2014-09-19

    The process of osteoblast differentiation is regulated by several factors, including RUNX2. Recent reports suggest an involvement of RUNX2 in DNA damage response (DDR), which is important due to association of differentiation with oxidative stress. In the present work we explore the influence of two RUNX2 modifiers, dexamethasone (DEX) and 1,25-dihydroxyvitamin D3 (1,25-D3), in DDR in differentiating MC3T3-E1 preosteoblasts challenged by oxidative stress. The process of differentiation was associated with reactive oxygen species (ROS) production and tert-butyl hydroperoxide (TBH) reduced the rate of differentiation. The activity of alkaline phosphatase (ALP), a marker of the process of osteoblasts differentiation, increased in a time-dependent manner and TBH further increased this activity. This may indicate that additional oxidative stress, induced by TBH, may accelerate the differentiation process. The cells displayed changes in the sensitivity to TBH in the course of differentiation. DEX increased ALP activity, but 1,25-D3 had no effect on it. These results suggest that DEX might stimulate the process of preosteoblasts differentiation. Finally, we observed a protective effect of DEX and 1,25-D3 against DNA damage induced by TBH, except the day 24 of differentiation, when DEX increased the extent of TBH-induced DNA damage. We conclude that oxidative stress is associated with osteoblasts differentiation and induce DDR, which may be modulated by RUNX2-modifiers, DEX and 1,25-D3.

  11. A high-fat and cholesterol diet causes fatty liver in guinea pigs. The role of iron and oxidative damage.

    PubMed

    Ye, P; Cheah, I K; Halliwell, B

    2013-08-01

    Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disease. Iron, cholesterol, and oxidative damage are frequently suggested to be related to the progression of NAFLD, but the precise relationship between them remains unclear. Guinea pigs fed on a high cholesterol and fat diet (without oxidized lipids) generated a disease model of NAFLD with hallmark observations in liver histology and increased liver damage markers. Hepatic cholesterol and iron levels were found to be significantly elevated and directly correlated. Plasma hepcidin and transferrin levels were decreased. Plasma iron concentrations were found to be elevated, likely due to an increased intestinal iron absorption caused by the decrease in plasma hepcidin. However, hepatic transferrin receptor-2 levels were unchanged. No significant increase in hepatic lipid peroxidation was detected using F2-isoprostanes as a reliable biomarker, nor was there a rise in protein carbonyls, a general index of oxidative protein damage. Some increases in cholesterol oxidation products were observed, but largely negated after normalizing for the elevated hepatic cholesterol content. Indeed, increased hemosiderin deposition and unchanged ferritin levels in liver suggested that the excess iron mainly existed as hemosiderin, which is redox-inactive.

  12. Oxidative damage and cellular defense mechanisms in sea urchin models of aging.

    PubMed

    Du, Colin; Anderson, Arielle; Lortie, Mae; Parsons, Rachel; Bodnar, Andrea

    2013-10-01

    The free radical, or oxidative stress, theory of aging proposes that the accumulation of oxidative cellular damage is a major contributor to the aging process and a key determinant of species longevity. This study investigates the oxidative stress theory in a novel model for aging research, the sea urchin. Sea urchins present a unique model for the study of aging because of the existence of species with tremendously different natural life spans, including some species with extraordinary longevity and negligible senescence. Cellular oxidative damage, antioxidant capacity, and proteasome enzyme activities were measured in the tissues of three sea urchin species: short-lived Lytechinus variegatus, long-lived Strongylocentrotus franciscanus, and Strongylocentrotus purpuratus, which has an intermediate life span. Levels of protein carbonyls and 4-hydroxynonenal measured in tissues (muscle, nerve, esophagus, gonad, coelomocytes, ampullae) and 8-hydroxy-2'-deoxyguanosine measured in cell-free coelomic fluid showed no general increase with age. The fluorescent age pigment lipofuscin, measured in muscle, nerve, and esophagus, increased with age; however, it appeared to be predominantly extracellular. Antioxidant mechanisms (total antioxidant capacity, superoxide dismutase) and proteasome enzyme activities were maintained with age. In some instances, levels of oxidative damage were lower and antioxidant activity higher in cells or tissues of the long-lived species compared to the short-lived species; however, further studies are required to determine the relationship between oxidative damage and longevity in these animals. Consistent with the predictions of the oxidative stress theory of aging, the results suggest that negligible senescence is accompanied by a lack of accumulation of cellular oxidative damage with age, and maintenance of antioxidant capacity and proteasome enzyme activities may be important mechanisms to mitigate damage.

  13. Oxidative Damage and Cellular Defense Mechanisms in Sea Urchin Models of Aging

    PubMed Central

    Du, Colin; Anderson, Arielle; Lortie, Mae; Parsons, Rachel; Bodnar, Andrea

    2013-01-01

    The free radical or oxidative stress theory of aging proposes that the accumulation of oxidative cellular damage is a major contributor to the aging process and a key determinant of species longevity. This study investigates the oxidative stress theory in a novel model for aging research, the sea urchin. Sea urchins present a unique model for the study of aging due to the existence of species with tremendously different natural life spans including some species with extraordinary longevity and negligible senescence. Cellular oxidative damage, antioxidant capacity and proteasome enzyme activities were measured in the tissues of three sea urchin species: short-lived Lytechinus variegatus, long-lived Strongylocentrotus franciscanus and Strongylocentrotus purpuratus which has an intermediate lifespan. Levels of protein carbonyls and 4-hydroxynonenal (HNE) measured in tissues (muscle, nerve, esophagus, gonad, coelomocytes, ampullae) and 8-hydroxy-2’-deoxyguanosine (8-OHdG) measured in cell-free coelomic fluid showed no general increase with age. The fluorescent age-pigment lipofuscin measured in muscle, nerve and esophagus, increased with age however it appeared to be predominantly extracellular. Antioxidant mechanisms (total antioxidant capacity, superoxide dismutase) and proteasome enzyme activities were maintained with age. In some instances, levels of oxidative damage were lower and antioxidant activity higher in cells or tissues of the long-lived species compared to the short-lived species, however further studies are required to determine the relationship between oxidative damage and longevity in these animals. Consistent with the predictions of the oxidative stress theory of aging, the results suggest that negligible senescence is accompanied by a lack of accumulation of cellular oxidative damage with age and maintenance of antioxidant capacity and proteasome enzyme activities may be important mechanisms to mitigate damage. PMID:23707327

  14. Saikosaponin-D attenuates heat stress-induced oxidative damage in LLC-PK1 cells by increasing the expression of anti-oxidant enzymes and HSP72.

    PubMed

    Zhang, Bao-Zhen; Guo, Xiao-Tong; Chen, Jian-Wei; Zhao, Yuan; Cong, Xia; Jiang, Zhong-Ling; Cao, Rong-Feng; Cui, Kai; Gao, Shan-Song; Tian, Wen-Ru

    2014-01-01

    Heat stress stimulates the production of reactive oxygen species (ROS), which cause oxidative damage in the kidney. This study clarifies the mechanism by which saikosaponin-d (SSd), which is extracted from the roots of Bupleurum falcatum L, protects heat-stressed pig kidney proximal tubular (LLC-PK1) cells against oxidative damage. SSd alone is not cytotoxic at concentrations of 1 or 3 μg/mL as demonstrated by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. To assess the effects of SSd on heat stress-induced cellular damage, LLC-PK1 cells were pretreated with various concentrations of SSd, heat stressed at 42°C for 1 h, and then returned to 37°C for 9 h. DNA ladder and MTT assays demonstrated that SSd helped to prevent heat stress-induced cellular damage when compared to untreated cells. Additionally, pretreatment with SSd increased the activity of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) but decreased the concentration of malondialdehyde (MDA) in a dose-dependent manner when compared to controls. Furthermore, real-time PCR and Western blot analysis demonstrated that SSd significantly increased the expression of copper and zinc superoxide dismutase (SOD-1), CAT, GPx-1 and heat shock protein 72 (HSP72) at both the mRNA and protein levels. In conclusion, these results are the first to demonstrate that SSd ameliorates heat stress-induced oxidative damage by modulating the activity of anti-oxidant enzymes and HSP72 in LLC-PK1 cells.

  15. Identification of the C4'-oxidized abasic site as the most abundant 2-deoxyribose lesion in radiation-damaged DNA using a novel HPLC-based approach.

    PubMed

    Roginskaya, Marina; Mohseni, Reza; Moore, Terence J; Bernhard, William A; Razskazovskiy, Yuriy

    2014-02-01

    A novel analytical high-performance liquid chromatography (HPLC)-based method of quantification of the yields of C4'-oxidized abasic sites, 1, in oxidatively damaged DNA has been elaborated. This new approach is based on efficient conversion of 1 into N-substituted 5-methylene-Δ(3)-pyrrolin-2-ones, 2, upon treatment of damaged DNA with primary amines in neutral or slightly acidic solutions with subsequent quantification of 2 by HPLC. The absolute and relative radiation-chemical yields of 1 in irradiated DNA solutions were re-evaluated using this method. The yields were compared with those of other 2-deoxyribose degradation products including 5-methylene-2(5H)-furanone, malondialdehyde, and furfural resulting from the C1', C4' and C5'-oxidations, respectively. The yield of free base release (FBR) determined in the same systems was employed as an internal measure of the total oxidative damage to the 2-deoxyribose moiety. Application of this technique identifies 1 as the most abundant sugar lesion in double-stranded (ds) DNA irradiated under air in solution (36% FBR). In single-stranded (ss) DNA this product is second by abundance (33% FBR) after 2-deoxyribonolactones (C1'-oxidation; 43% FBR). The production of nucleoside-5'-aldehydes (C5'-oxidation; 14% and 5% FBR in dsDNA and ssDNA, respectively) is in the third place. Taken together with the parallel reaction channel that converts C4'-radicals into malondialdehyde and 3'-phosphoglycolates, our results identify the C4'-oxidation as a prevalent pathway of oxidative damage to the sugar-phosphate backbone (50% or more of all 2-deoxyribose damages) in indirectly damaged DNA.

  16. New Perspectives on Oxidized Genome Damage and Repair Inhibition by Pro-Oxidant Metals in Neurological Diseases

    PubMed Central

    Mitra, Joy; Guerrero, Erika N.; Hegde, Pavana M.; Wang, Haibo; Boldogh, Istvan; Rao, Kosagi Sharaf; Mitra, Sankar; Hegde, Muralidhar L.

    2014-01-01

    The primary cause(s) of neuronal death in most cases of neurodegenerative diseases, including Alzheimer’s and Parkinson’s disease, are still unknown. However, the association of certain etiological factors, e.g., oxidative stress, protein misfolding/aggregation, redox metal accumulation and various types of damage to the genome, to pathological changes in the affected brain region(s) have been consistently observed. While redox metal toxicity received major attention in the last decade, its potential as a therapeutic target is still at a cross-roads, mostly because of the lack of mechanistic understanding of metal dyshomeostasis in affected neurons. Furthermore, previous studies have established the role of metals in causing genome damage, both directly and via the generation of reactive oxygen species (ROS), but little was known about their impact on genome repair. Our recent studies demonstrated that excess levels of iron and copper observed in neurodegenerative disease-affected brain neurons could not only induce genome damage in neurons, but also affect their repair by oxidatively inhibiting NEIL DNA glycosylases, which initiate the repair of oxidized DNA bases. The inhibitory effect was reversed by a combination of metal chelators and reducing agents, which underscore the need for elucidating the molecular basis for the neuronal toxicity of metals in order to develop effective therapeutic approaches. In this review, we have focused on the oxidative genome damage repair pathway as a potential target for reducing pro-oxidant metal toxicity in neurological diseases. PMID:25036887

  17. Oxidative DNA damage is a preliminary step during rat tongue carcinogenesis induced by 4-nitroquinoline 1-oxide.

    PubMed

    Miranda, Sandra Regina; Noguti, Juliana; Carvalho, Juliana Gonçalves; Oshima, Celina Tijuko Fujiyama; Ribeiro, Daniel Araki

    2011-04-01

    The aim of this study was to investigate oxidative DNA damage during 4-nitroquinoline 1-oxide (4NQO)-induced rat tongue carcinogenesis. For this purpose, male Wistar rats were distributed into three groups of 10 animals each and treated with 50 ppm 4NQO solution through their drinking water for 4, 12, and 20 weeks. Ten animals were used as negative control. The alkaline Comet assay modified with lesion-specific enzymes was used to detect single and double strand breaks, labile sites (SBs), and oxidised purines and pyrimidines. Although no histopathological abnormalities were induced in the epithelium after 4 weeks of carcinogen exposure, oxidative DNA damage was detected in the 'normal' oral epithelium. In pre-neoplastic lesions and squamous cell carcinomas induced after 12 and 20 weeks following carcinogen exposure, respectively, oxidative DNA damage was also increased (P < 0.05) when compared to negative control. In conclusion, our results suggest that oxidative DNA damage is an early event during multistep carcinogenesis assay induced by 4NQO. This kind of approach should be considered to persons with high risk of oral cancer, such as in smokers or alcohol consumers.

  18. Aryl Hydrocarbon Receptor Ligand 5F 203 Induces Oxidative Stress That Triggers DNA Damage in Human Breast Cancer Cells

    PubMed Central

    McLean, Lancelot S.; Watkins, Cheri N.; Campbell, Petreena; Zylstra, Dain; Rowland, Leah; Amis, Louisa H.; Scott, Lia; Babb, Crystal E.; Livingston, W. Joel; Darwanto, Agus; Davis, Willie L.; Senthil, Maheswari; Sowers, Lawrence C.; Brantley, Eileen

    2015-01-01

    Breast tumors often show profound sensitivity to exogenous oxidative stress. Investigational agent 2-(4-amino-3-methylphenyl)-5-fluorobenzothiazole (5F 203) induces aryl hydrocarbon receptor (AhR)-mediated DNA damage in certain breast cancer cells. Since AhR agonists often elevate intracellular oxidative stress, we hypothesize that 5F 203 increases reactive oxygen species (ROS) to induce DNA damage, which thwarts breast cancer cell growth. We found that 5F 203 induced single-strand break formation. 5F 203 enhanced oxidative DNA damage that was specific to breast cancer cells sensitive to its cytotoxic actions, as it did not increase oxidative DNA damage or ROS formation in nontumorigenic MCF-10A breast epithelial cells. In contrast, AhR agonist and procarcinogen benzo[a]pyrene and its metabolite, 1,6-benzo[a]pyrene quinone, induced oxidative DNA damage and ROS formation, respectively, in MCF-10A cells. In sensitive breast cancer cells, 5F 203 activated ROS-responsive kinases: c-Jun-N-terminal kinase (JNK) and p38 mitogen activated protein kinase (p38). AhR antagonists (alpha-naphthoflavone, CH223191) or antioxidants (N-acetyl-l-cysteine, EUK-134) attenuated 5F 203-mediated JNK and p38 activation, depending on the cell type. Pharmacological inhibition of AhR, JNK, or p38 attenuated 5F 203-mediated increases in intracellular ROS, apoptosis, and single-strand break formation. 5F 203 induced the expression of cytoglobin, an oxidative stress-responsive gene and a putative tumor suppressor, which was diminished with AhR, JNK, or p38 inhibition. Additionally, 5F 203-mediated increases in ROS production and cytoglobin were suppressed in AHR100 cells (AhR ligand-unresponsive MCF-7 breast cancer cells). Our data demonstrate 5F 203 induces ROS-mediated DNA damage at least in part via AhR, JNK, or p38 activation and modulates the expression of oxidative stress-responsive genes such as cytoglobin to confer its anticancer action. PMID:25781201

  19. Environmentally relevant concentrations of galaxolide (HHCB) and tonalide (AHTN) induced oxidative and genetic damage in Dreissena polymorpha.

    PubMed

    Parolini, Marco; Magni, Stefano; Traversi, Irene; Villa, Sara; Finizio, Antonio; Binelli, Andrea

    2015-03-21

    Synthetic musk compounds (SMCs) are extensively used as fragrances in several personal care products and have been recognized as emerging aquatic pollutants. Among SMCs, galaxolide (HHCB) and tonalide (AHTN) are extensively used and have been measured in aquatic ecosystems worldwide. However, their potential risk to organisms remains largely unknown. The aim of this study was to investigate whether 21-day exposures to HHCB and AHTN concentrations frequently measured in aquatic ecosystems can induce oxidative and genetic damage in Dreissena polymorpha. The lipid peroxidation (LPO) and protein carbonyl content (PCC) were measured as oxidative stress indexes, while the DNA precipitation assay and the micronucleus test (MN test) were applied to investigate genetic injuries. HHCB induced significant increases in LPO and PCC levels, while AHTN enhanced only protein carbonylation. Moreover, significant increases in DNA strand breaks were caused by exposure to the highest concentrations of HHCB and AHTN tested in the present study, but no fixed genetic damage was observed.

  20. Nrf2 is critical in defense against high glucose-induced oxidative damage in cardiomyocytes.

    PubMed

    He, Xiaoqing; Kan, Hong; Cai, Lu; Ma, Qiang

    2009-01-01

    Exposure to high levels of glucose induces the production of reactive oxygen species (ROS) in cardiomyocytes that may contribute to the development of cardiomyopathy in diabetes. Nuclear factor erythroid 2-related factor 2 (Nrf2) controls the antioxidant response element (ARE)-dependent gene regulation in response to oxidative stress. The role of Nrf2 in defense against high glucose-induced oxidative damage in cardiomyocytes was investigated. Glucose at high concentrations induced ROS production in both primary neonatal and adult cardiomyocytes from the Nrf2 wild type (WT) mouse heart, whereas, in Nrf2 knockout (KO) cells, ROS was significantly higher under basal conditions and high glucose markedly further increased ROS production in concentration and time-dependent manners. Concomitantly, high glucose induced significantly higher levels of apoptosis at lower concentrations and in shorter time in Nrf2 KO cells than in WT cells. Primary adult cardiomyocytes from control and diabetic mice also showed dependence on Nrf2 function for isoproterenol-stimulated contraction. Additionally, cardiomyocytes from Nrf2 KO mice exhibited increased sensitivity to 3-nitropropionic acid, an inhibitor of mitochondrial respiratory complex II, for both ROS production and apoptosis compared with Nrf2 WT cells, further emphasizing the role of Nrf2 in ROS defense in the cells. Mechanistically, Nrf2 was shown to mediate the basal expression and induction of ARE-controlled cytoprotective genes, Nqo1 and Ho1, at both mRNA and protein levels in cardiomyocytes, as both the basal and inducible expressions of the genes were lost in Nrf2 KO cells or largely reduced by Nrf2 SiRNA. The findings, for the first time, established Nrf2 as a critical regulator of defense against ROS in normal and diabetic hearts.

  1. Effects of arginine on hair damage via oxidative coloring process.

    PubMed

    Oshimura, Eiko; Ino, Masahiro

    2004-01-01

    The purpose of this study was to measure the protective effects of arginine in oxidative coloring or bleaching process. Contact angle measurement, tensile measurement and amino acid analysis were employed. As the first step, it was shown that oxidative coloring or bleaching process decreases hair surface hydrophobicity and tensile strength in wet condition. Next the study has been conducted with coloring agents in which part of the ammonia was replaced with arginine, to find that arginine reduced the oxidative change in contact angle and tensile strength. These results suggest that arginine prevents the undesirable attack by hydrogen peroxide on hair proteins and hair surface lipids. Furthermore, it is also suggested from amino acid analysis that a considerable amount of arginine is deposited on, or in hair fibers from coloring agents.

  2. Atmospheric Nonthermal Plasma-Treated PBS Inactivates Escherichia coli by Oxidative DNA Damage.

    PubMed

    Yost, Adam D; Joshi, Suresh G

    2015-01-01

    We recently reported that phosphate-buffered saline (PBS) treated with nonthermal dielectric-barrier discharge plasma (plasma) acquires strong antimicrobial properties, but the mechanisms underlying bacterial inactivation were not known. The goal of this study is to understand the cellular responses of Escherichia coli and to investigate the properties of plasma-activated PBS. The plasma-activated PBS induces severe oxidative stress in E. coli cells and reactive-oxygen species scavengers, α-tocopherol and catalase, protect E. coli from cell death. Here we show that the response of E. coli to plasma-activated PBS is regulated by OxyR and SoxyRS regulons, and mediated predominantly through the expression of katG that deactivates plasma-generated oxidants. During compensation of E. coli in the absence of both katG and katE, sodA and sodB are significantly overexpressed in samples exposed to plasma-treated PBS. Microarray analysis found that up-regulation of genes involved in DNA repair, and E. coli expressing recA::lux fusion was extremely sensitive to the SOS response upon exposure to plasma-treated PBS. The cellular changes include rapid loss of E. coli membrane potential and membrane integrity, lipid peroxidation, accumulation of 8-hydroxy-deoxyguinosine (8OHdG), and severe oxidative DNA damage; reveal ultimate DNA disintegration, and cell death. Together, these data suggest that plasma-treated PBS contains hydrogen peroxide and superoxide like reactive species or/and their products which lead to oxidative changes to cell components, and are eventually responsible for cell death.

  3. Brown propolis attenuates cerebral ischemia-induced oxidative damage via affecting antioxidant enzyme system in mice.

    PubMed

    Bazmandegan, Gholamreza; Boroushaki, Mohammad Taher; Shamsizadeh, Ali; Ayoobi, Fatemeh; Hakimizadeh, Elham; Allahtavakoli, Mohammad

    2017-01-01

    Oxidative stress plays a critical role in ischemic brain injury. Superoxide dismutase (SOD) and glutathione peroxidase (GPx) are the enzymes underlying the endogenous antioxidant mechanisms affected by stroke and are considered as oxidative stress biomarkers. Brown propolis (BP) is a bioactive natural product with a set of biological activities that in turn may differ depending on the area from which the substance is originated. The aim of this study was to investigate the effect of water-extracted brown propolis (WEBPs), from two regions of Iran, against cerebral ischemia-induced oxidative injury in a mouse model of stroke. Experimentally, the chemical characterization and total polyphenol content were determined using GC/MS and Folin-Ciocalteu assay respectively. Seventy-two adult male mice were randomly divided into the surgical sham group, control group (treated with vehicle), and four groups of WEBPs-treated animals. The WEBPs were administered at the doses of 100 and 200mg/kg IP, during four different time points. Oxidative stress biomarkers (SOD and GPx activity, SOD/GPx ratio), lipid peroxidation (LPO) index (malondialdehyde content) and infarct volume were measured 48h post stroke. Behavioral tests were evaluated 24 and 48h after stroke. WEBPs treatment resulted in significant restoration of antioxidant enzymes activity and a subsequent decrease in LPO as well as the infarct volume compared to the control group. Sensory-motor impairment and neurological deficits were improved significantly as well. These results indicate that Iranian BP confers neuroprotection on the stroke-induced neuronal damage via an antioxidant mechanism which seems to be mediated by the endogenous antioxidant system. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  4. Atmospheric Nonthermal Plasma-Treated PBS Inactivates Escherichia coli by Oxidative DNA Damage

    PubMed Central

    Yost, Adam D.; Joshi, Suresh G.

    2015-01-01

    We recently reported that phosphate-buffered saline (PBS) treated with nonthermal dielectric-barrier discharge plasma (plasma) acquires strong antimicrobial properties, but the mechanisms underlying bacterial inactivation were not known. The goal of this study is to understand the cellular responses of Escherichia coli and to investigate the properties of plasma-activated PBS. The plasma-activated PBS induces severe oxidative stress in E. coli cells and reactive-oxygen species scavengers, α-tocopherol and catalase, protect E. coli from cell death. Here we show that the response of E. coli to plasma-activated PBS is regulated by OxyR and SoxyRS regulons, and mediated predominantly through the expression of katG that deactivates plasma-generated oxidants. During compensation of E. coli in the absence of both katG and katE, sodA and sodB are significantly overexpressed in samples exposed to plasma-treated PBS. Microarray analysis found that up-regulation of genes involved in DNA repair, and E. coli expressing recA::lux fusion was extremely sensitive to the SOS response upon exposure to plasma-treated PBS. The cellular changes include rapid loss of E. coli membrane potential and membrane integrity, lipid peroxidation, accumulation of 8-hydroxy-deoxyguinosine (8OHdG), and severe oxidative DNA damage; reveal ultimate DNA disintegration, and cell death. Together, these data suggest that plasma-treated PBS contains hydrogen peroxide and superoxide like reactive species or/and their products which lead to oxidative changes to cell components, and are eventually responsible for cell death. PMID:26461113

  5. The molecular chaperone Hsp70 promotes the proteolytic removal of oxidatively damaged proteins by the proteasome

    PubMed Central

    Reeg, Sandra; Jung, Tobias; Castro, José P.; Davies, Kelvin J.A.; Henze, Andrea; Grune, Tilman

    2016-01-01

    One hallmark of aging is the accumulation of protein aggregates, promoted by the unfolding of oxidized proteins. Unraveling the mechanism by which oxidized proteins are degraded may provide a basis to delay the early onset of features, such as protein aggregate formation, that contribute to the aging phenotype. In order to prevent aggregation of oxidized proteins, cells recur to the 20S proteasome, an efficient turnover proteolysis complex. It has previously been shown that upon oxidative stress the 26S proteasome, another form, dissociates into the 20S form. A critical player implicated in its dissociation is the Heat Shock Protein 70 (Hsp70), which promotes an increase in free 20S proteasome and, therefore, an increased capability to degrade oxidized proteins. The aim of this study was to test whether or not Hsp70 is involved in cooperating with the 20S proteasome for a selective degradation of oxidatively damaged proteins. Our results demonstrate that Hsp70 expression is induced in HT22 cells as a result of mild oxidative stress conditions. Furthermore, Hsp70 prevents the accumulation of oxidized proteins and directly promotes their degradation by the 20S proteasome. In contrast the expression of the Heat shock cognate protein 70 (Hsc70) was not changed in recovery after oxidative stress and Hsc70 has no influence on the removal of oxidatively damaged proteins. We were able to demonstrate in HT22 cells, in brain homogenates from 129/SV mice and in vitro, that there is an increased interaction of Hsp70 with oxidized proteins, but also with the 20S proteasome, indicating a role of Hsp70 in mediating the interaction of oxidized proteins with the 20S proteasome. Thus, our data clearly implicate an involvement of Hsp70 oxidatively damaged protein degradation by the 20S proteasome. PMID:27498116

  6. Unbalanced oxidant-induced DNA damage and repair in COPD: a link towards lung cancer.

    PubMed

    Caramori, Gaetano; Adcock, Ian M; Casolari, Paolo; Ito, Kazuhiro; Jazrawi, Elen; Tsaprouni, Loukia; Villetti, Gino; Civelli, Maurizio; Carnini, Chiara; Chung, Kian Fan; Barnes, Peter J; Papi, Alberto

    2011-06-01

    Chronic obstructive pulmonary disease (COPD) is characterised by oxidative stress and increased risk of lung carcinoma. Oxidative stress causes DNA damage which can be repaired by DNA-dependent protein kinase complex. To investigate DNA damage/repair balance and DNA-dependent protein kinase complex in COPD lung and in an animal model of smoking-induced lung damage and to evaluate the effects of oxidative stress on Ku expression and function in human bronchial epithelial cells. Protein expression was quantified using immunohistochemistry and/or western blotting. DNA damage/repair was measured using colorimetric assays. 8-OH-dG, a marker of oxidant-induced DNA damage, was statistically significantly increased in the peripheral lung of smokers (with and without COPD) compared with non-smokers, while the number of apurinic/apyrimidinic (AP) sites (DNA damage and repair) was increased in smokers compared with non-smokers (p = 0.0012) and patients with COPD (p < 0.0148). Nuclear expression of Ku86, but not of DNA-PKcs, phospho-DNA-PKcs, Ku70 or γ-H2AFX, was reduced in bronchiolar epithelial cells from patients with COPD compared with normal smokers and non-smokers (p < 0.039). Loss of Ku86 expression was also observed in a smoking mouse model (p < 0.012) and prevented by antioxidants. Oxidants reduced (p < 0.0112) Ku86 expression in human bronchial epithelial cells and Ku86 knock down modified AP sites in response to oxidative stress. Ineffective DNA repair rather than strand breakage per se accounts for the reduced AP sites observed in COPD and this is correlated with a selective decrease of the expression of Ku86 in the bronchiolar epithelium. DNA damage/repair imbalance may contribute to increased risk of lung carcinoma in COPD.

  7. Radiation Damage and Fission Product Release in Zirconium Nitride

    SciTech Connect

    Egeland, Gerald W.

    2005-08-29

    Zirconium nitride is a material of interest to the AFCI program due to some of its particular properties, such as its high melting point, strength and thermal conductivity. It is to be used as an inert matrix or diluent with a nuclear fuel based on transuranics. As such, it must sustain not only high temperatures, but also continuous irradiation from fission and decay products. This study addresses the issues of irradiation damage and fission product retention in zirconium nitride through an assessment of defects that are produced, how they react, and how predictions can be made as to the overall lifespan of the complete nuclear fuel package. Ion irradiation experiments are a standard method for producing radiation damage to a surface for observation. Cryogenic irradiations are performed to produce the maximum accumulation of defects, while elevated temperature irradiations may be used to allow defects to migrate and react to form clusters and loops. Cross-sectional transmission electron microscopy and grazing-incidence x-ray diffractometry were used in evaluating the effects that irradiation has on the crystal structure and microstructure of the material. Other techniques were employed to evaluate physical effects, such as nanoindentation and helium release measurements. Results of the irradiations showed that, at cryogenic temperatures, ZrN withstood over 200 displacements per atom without amorphization. No significant change to the lattice or microstructure was observed. At elevated temperatures, the large amount of damage showed mobility, but did not anneal significantly. Defect clustering was possibly observed, yet the size was too small to evaluate, and bubble formation was not observed. Defects, specifically nitrogen vacancies, affect the mechanical behavior of ZrN dramatically. Current and previous work on dislocations shows a distinct change in slip plane, which is evidence of the bonding characteristics. The stacking-fault energy changes dramatically with

  8. Smoking-promoted oxidative DNA damage response is highly correlated to lung carcinogenesis.

    PubMed

    Cao, Chao; Lai, Tianwen; Li, Miao; Zhou, Hongbin; Lv, Dan; Deng, Zaichun; Ying, Songmin; Chen, Zhihua; Li, Wen; Shen, Huahao

    2016-04-05

    Oxidative stress induced by tobacco smoking is one of the main causes of DNA damage and is known to be involved in various cancers. Smoking is the leading cause of lung cancer, while the role of cigarette smoke-induced oxidative DNA damage response during lung carcinogenesis is largely unknown. In this study, we investigated oxidative DNA damage response levels in smoking and nonsmoking patients with lung cancer, and evaluated the potential diagnostic value of 8-OHdG for lung cancer. We observed a higher level of 8-OHdG expression and secretion in airways of lung cancer patients than that of noncancer controls. 8-OHdG expression was associated with the TNM stages. Additionally, cigarette smoke-induced oxidative DNA damage response was observed in bronchial epithelial cells in vitro and in vivo. A statistical significance correlation was found between the levels of 8-OHdG and smoking index. With a cut-off value of 2.86 ng/ml, 8-OHdG showed a sensitivity and specificity of 70.0% and 73.7%, respectively, to identify a patient with lung cancer. These findings not only underscore the importance of smoking in oxidative DNA damage response of lung cancer patients, but also suggest 8-OHdG as a potential diagnostic biomarker for lung cancer.

  9. Vitamin E-coated dialysis membranes reduce the levels of oxidative genetic damage in hemodialysis patients.

    PubMed

    Rodríguez-Ribera, Lara; Corredor, Zuray; Silva, Irene; Díaz, Juan Manuel; Ballarín, José; Marcos, Ricard; Pastor, Susana; Coll, Elisabet

    2017-03-01

    End-stage renal disease patients present oxidative stress status that increases when they are submitted to hemodialysis (HD). This increase in oxidative stress can affect their genetic material, among other targets. The objective of this study was to evaluate the effect of using polysulfone membranes coated with vitamin E, during the HD sessions, on the levels of genetic damage of HD patients. Forty-six patients were followed for 6 months, of whom 29 changed from conventional HD to the use of membranes coated with vitamin E. The level of genetic damage was measured using the micronucleus and the comet assays, both before and after the follow-up period. Serum vitamin E concentration was also checked. The obtained results showed that 24% of our patients presented vitamin E deficiency, and this was normalized in those patients treated with vitamin E-coated membranes. Patients with vitamin E deficiency showed higher levels of oxidative DNA damage. After the use of vitamin E-coated membranes we detected a significant decrease in the levels of oxidative damage. Additionally, hemoglobin values increased significantly with the use of vitamin E-coated membranes. In conclusion, the use of vitamin E-coated membranes supposes a decrease on the levels of oxidative DNA damage, and improves the uremic anemia status. Furthermore, the use of this type of membrane was also effective in correcting vitamin E deficiency.

  10. MECHANISMS FOR COUNTERING OXIDATIVE STRESS AND DAMAGE IN RETINAL PIGMENT EPITHELIUM

    PubMed Central

    Plafker, Scott M.; O’Mealey, Gary B.; Szweda, Luke I.

    2013-01-01

    Clinical and experimental evidence supports that chronic oxidative stress is a primary contributing factor to numerous retinal degenerative diseases, such as age-related macular degeneration (AMD). Eyes obtained postmortem from AMD patients have extensive free radical damage to the proteins, lipids, DNA, and mitochondria of their retinal pigment epithelial (RPE) cells. In addition, several mouse models of chronic oxidative stress develop many of the pathological hallmarks of AMD. However, the extent to which oxidative stress is an etiologic component versus its involvement in disease progression remains a major unanswered question. Further, whether the primary target of oxidative stress and damage is photoreceptors or RPE cells, or both, is still unclear. In this review, we discuss the major functions of RPE cells with an emphasis on the oxidative challenges these cells encounter and the endogenous antioxidant mechanisms employed to neutralize the deleterious effects that such stresses can elicit if left unchecked. PMID:22878106

  11. Oxidative Stress in Ischemic Brain Damage: Mechanisms of Cell Death and Potential Molecular Targets for Neuroprotection

    PubMed Central

    Chen, Hai; Yoshioka, Hideyuki; Kim, Gab Seok; Jung, Joo Eun; Okami, Nobuya; Sakata, Hiroyuki; Maier, Carolina M.; Narasimhan, Purnima; Goeders, Christina E.

    2011-01-01

    Abstract Significant amounts of oxygen free radicals (oxidants) are generated during cerebral ischemia/reperfusion, and oxidative stress plays an important role in brain damage after stroke. In addition to oxidizing macromolecules, leading to cell injury, oxidants are also involved in cell death/survival signal pathways and cause mitochondrial dysfunction. Experimental data from laboratory animals that either overexpress (transgenic) or are deficient in (knock-out) antioxidant proteins, mainly superoxide dismutase, have provided strong evidence of the role of oxidative stress in ischemic brain damage. In addition to mitochondria, recent reports demonstrate that NADPH oxidase (NOX), an important pro-oxidant enzyme, is also involved in the generation of oxidants in the brain after stroke. Inhibition of NOX is neuroprotective against cerebral ischemia. We propose that superoxide dismutase and NOX activity in the brain is a major determinant for ischemic damage/repair and that these major anti- and pro-oxidant enzymes are potential endogenous molecular targets for stroke therapy. Antioxid. Redox Signal. 14, 1505–1517. PMID:20812869

  12. Preventive Effects of Poloxamer 188 on Muscle Cell Damage Mechanics Under Oxidative Stress.

    PubMed

    Wong, Sing Wan; Yao, Yifei; Hong, Ye; Ma, Zhiyao; Kok, Stanton H L; Sun, Shan; Cho, Michael; Lee, Kenneth K H; Mak, Arthur F T

    2017-04-01

    High oxidative stress can occur during ischemic reperfusion and chronic inflammation. It has been hypothesized that such oxidative challenges could contribute to clinical risks such as deep tissue pressure ulcers. Skeletal muscles can be challenged by inflammation-induced or reperfusion-induced oxidative stress. Oxidative stress reportedly can lower the compressive damage threshold of skeletal muscles cells, causing actin filament depolymerization, and reduce membrane sealing ability. Skeletal muscles thus become easier to be damaged by mechanical loading under prolonged oxidative exposure. In this study, we investigated the preventive effect of poloxamer 188 (P188) on skeletal muscle cells against extrinsic oxidative challenges (H2O2). It was found that with 1 mM P188 pre-treatment for 1 h, skeletal muscle cells could maintain their compressive damage threshold. The actin polymerization dynamics largely remained stable in term of the expression of cofilin, thymosin beta 4 and profilin. Laser photoporation demonstrated that membrane sealing ability was preserved even as the cells were challenged by H2O2. These findings suggest that P188 pre-treatment can help skeletal muscle cells retain their normal mechanical integrity in oxidative environments, adding a potential clinical use of P188 against the combined challenge of mechanical-oxidative stresses. Such effect may help to prevent deep tissue ulcer development.

  13. CUX2 protein functions as an accessory factor in the repair of oxidative DNA damage.

    PubMed

    Pal, Ranjana; Ramdzan, Zubaidah M; Kaur, Simran; Duquette, Philippe M; Marcotte, Richard; Leduy, Lam; Davoudi, Sayeh; Lamarche-Vane, Nathalie; Iulianella, Angelo; Nepveu, Alain

    2015-09-11

    CUX1 and CUX2 proteins are characterized by the presence of three highly similar regions called Cut repeats 1, 2, and 3. Although CUX1 is ubiquitously expressed, CUX2 plays an important role in the specification of neuronal cells and continues to be expressed in postmitotic neurons. Cut repeats from the CUX1 protein were recently shown to stimulate 8-oxoguanine DNA glycosylase 1 (OGG1), an enzyme that removes oxidized purines from DNA and introduces a single strand break through its apurinic/apyrimidinic lyase activity to initiate base excision repair. Here, we investigated whether CUX2 plays a similar role in the repair of oxidative DNA damage. Cux2 knockdown in embryonic cortical neurons increased levels of oxidative DNA damage. In vitro, Cut repeats from CUX2 increased the binding of OGG1 to 7,8-dihydro-8-oxoguanine-containing DNA and stimulated both the glycosylase and apurinic/apyrimidinic lyase activities of OGG1. Genetic inactivation in mouse embryo fibroblasts or CUX2 knockdown in HCC38 cells delayed DNA repair and increased DNA damage. Conversely, ectopic expression of Cut repeats from CUX2 accelerated DNA repair and reduced levels of oxidative DNA damage. These results demonstrate that CUX2 functions as an accessory factor that stimulates the repair of oxidative DNA damage. Neurons produce a high level of reactive oxygen species because of their dependence on aerobic oxidation of glucose as their source of energy. Our results suggest that the persistent expression of CUX2 in postmitotic neurons contributes to the maintenance of genome integrity through its stimulation of oxidative DNA damage repair. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  14. Graphene oxide and H2 production from bioelectrochemical graphite oxidation

    NASA Astrophysics Data System (ADS)

    Lu, Lu; Zeng, Cuiping; Wang, Luda; Yin, Xiaobo; Jin, Song; Lu, Anhuai; Jason Ren, Zhiyong

    2015-11-01

    Graphene oxide (GO) is an emerging material for energy and environmental applications, but it has been primarily produced using chemical processes involving high energy consumption and hazardous chemicals. In this study, we reported a new bioelectrochemical method to produce GO from graphite under ambient conditions without chemical amendments, value-added organic compounds and high rate H2 were also produced. Compared with abiotic electrochemical electrolysis control, the microbial assisted graphite oxidation produced high rate of graphite oxide and graphene oxide (BEGO) sheets, CO2, and current at lower applied voltage. The resultant electrons are transferred to a biocathode, where H2 and organic compounds are produced by microbial reduction of protons and CO2, respectively, a process known as microbial electrosynthesis (MES). Pseudomonas is the dominant population on the anode, while abundant anaerobic solvent-producing bacteria Clostridium carboxidivorans is likely responsible for electrosynthesis on the cathode. Oxygen production through water electrolysis was not detected on the anode due to the presence of facultative and aerobic bacteria as O2 sinkers. This new method provides a sustainable route for producing graphene materials and renewable H2 at low cost, and it may stimulate a new area of research in MES.

  15. Graphene oxide and H2 production from bioelectrochemical graphite oxidation

    PubMed Central

    Lu, Lu; Zeng, Cuiping; Wang, Luda; Yin, Xiaobo; Jin, Song; Lu, Anhuai; Jason Ren, Zhiyong

    2015-01-01

    Graphene oxide (GO) is an emerging material for energy and environmental applications, but it has been primarily produced using chemical processes involving high energy consumption and hazardous chemicals. In this study, we reported a new bioelectrochemical method to produce GO from graphite under ambient conditions without chemical amendments, value-added organic compounds and high rate H2 were also produced. Compared with abiotic electrochemical electrolysis control, the microbial assisted graphite oxidation produced high rate of graphite oxide and graphene oxide (BEGO) sheets, CO2, and current at lower applied voltage. The resultant electrons are transferred to a biocathode, where H2 and organic compounds are produced by microbial reduction of protons and CO2, respectively, a process known as microbial electrosynthesis (MES). Pseudomonas is the dominant population on the anode, while abundant anaerobic solvent-producing bacteria Clostridium carboxidivorans is likely responsible for electrosynthesis on the cathode. Oxygen production through water electrolysis was not detected on the anode due to the presence of facultative and aerobic bacteria as O2 sinkers. This new method provides a sustainable route for producing graphene materials and renewable H2 at low cost, and it may stimulate a new area of research in MES. PMID:26573014

  16. Graphene oxide and H2 production from bioelectrochemical graphite oxidation.

    PubMed

    Lu, Lu; Zeng, Cuiping; Wang, Luda; Yin, Xiaobo; Jin, Song; Lu, Anhuai; Jason Ren, Zhiyong

    2015-11-17

    Graphene oxide (GO) is an emerging material for energy and environmental applications, but it has been primarily produced using chemical processes involving high energy consumption and hazardous chemicals. In this study, we reported a new bioelectrochemical method to produce GO from graphite under ambient conditions without chemical amendments, value-added organic compounds and high rate H2 were also produced. Compared with abiotic electrochemical electrolysis control, the microbial assisted graphite oxidation produced high rate of graphite oxide and graphene oxide (BEGO) sheets, CO2, and current at lower applied voltage. The resultant electrons are transferred to a biocathode, where H2 and organic compounds are produced by microbial reduction of protons and CO2, respectively, a process known as microbial electrosynthesis (MES). Pseudomonas is the dominant population on the anode, while abundant anaerobic solvent-producing bacteria Clostridium carboxidivorans is likely responsible for electrosynthesis on the cathode. Oxygen production through water electrolysis was not detected on the anode due to the presence of facultative and aerobic bacteria as O2 sinkers. This new method provides a sustainable route for producing graphene materials and renewable H2 at low cost, and it may stimulate a new area of research in MES.

  17. Pentoxifylline Diminishes the Oxidative Damage to Renal Tissue Induced by Streptozotocin in the Rat

    PubMed Central

    Martínez-Morales, F.

    2004-01-01

    Oxidative damage has been suggested to be a contributing factor in the development to diabetic nephropathy (DN). Recently, there has been evidence that pentoxifylline (PTX) has free radical-scavenging properties; thus, its antiinflammatory and renoprotective effects may be related to a reduction in reactive oxygen species production. It is likely that the pharmacological effects of PTX include an antioxidant mechanism as shown in in vitro assays. The aim of this study was to evaluate whether the reported renoprotective effects of PTX could be the result of its antioxidant actions in streptozotocin (STZ)-induced DN in rats. The administration of PTX over a period of 8 weeks, in addition to displaying renoprotective effects, caused a significant reduction in lipoperoxide levels (LPOS) in the diabetic kidney (P < 0.05), compared to untreated rats. These levels were comparable to those in the healthy kidney of experimental animals (P > 0.05). All untreated STZ rats exhibited an increase in LPOS as opposed to healthy controls (H) (P < 0.001). The total antioxidant activity (TAA) in plasma was increased significantly already after 2 days of STZ (P < 0.05). When we examined the progression of TAA in STZ rats, there was a significant decrease over 8 weeks (P < 0.05). PTX treatment caused an increase in TAA when compared to untreated STZ rats (P < 0.05). Renal hypertrophy was less evident in PTX-treated STZ than in untreated STZ rats, evaluated by kidney weight/body weight ratio. These results indicate that PTX decreases the oxidative damage induced by these experimental procedures and may increase antioxidant defense mechanisms in STZ-induced diabetes in rats. PMID:15763938

  18. Sulforaphane prevents microcystin-LR-induced oxidative damage and apoptosis in BALB/c mice

    SciTech Connect

    Sun Xiaoyun; Mi Lixin; Liu Jin; Song Lirong; Chung Funglung; Gan Nanqin

    2011-08-15

    Microcystins (MCs), the products of blooming algae Microcystis, are waterborne environmental toxins that have been implicated in the development of liver cancer, necrosis, and even fatal intrahepatic bleeding. Alternative protective approaches in addition to complete removal of MCs in drinking water are urgently needed. In our previous work, we found that sulforaphane (SFN) protects against microcystin-LR (MC-LR)-induced cytotoxicity by activating the NF-E2-related factor 2 (Nrf2)-mediated defensive response in human hepatoma (HepG2) and NIH 3T3 cells. The purpose of this study was to investigate and confirm efficacy the SFN-induced multi-mechanistic defense system against MC-induced hepatotoxicity in an animal model. We report that SFN protected against MC-LR-induced liver damage and animal death at a nontoxic and physiologically relevant dose in BALB/c mice. The protection by SFN included activities of anti-cytochrome P450 induction, anti-oxidation, anti-inflammation, and anti-apoptosis. Our results suggest that SFN may protect mice against MC-induced hepatotoxicity. This raises the possibility of a similar protective effect in human populations, particularly in developing countries where freshwaters are polluted by blooming algae. - Graphical abstract: Display Omitted Research Highlights: > SFN protected against MC-LR-induced liver damage and animal death in BALB/c mice. > The dose of SFN is at a nontoxic and physiologically relevant dose. > The protection included activities of anti-oxidation, anti-inflammation, and anti-apoptosis. > SFN may protect mice against MC-induced hepatotoxicity.

  19. Mechanisms of MDMA (ecstasy)-induced oxidative stress, mitochondrial dysfunction, and organ damage.

    PubMed

    Song, Byoung-Joon; Moon, Kwan-Hoon; Upreti, Vijay V; Eddington, Natalie D; Lee, Insong J

    2010-08-01

    Despite numerous reports about the acute and sub-chronic toxicities caused by MDMA (3,4-methylenedioxymethamphetamine, ecstasy), the underlying mechanism of organ damage is poorly understood. The aim of this review is to present an update of the mechanistic studies on MDMA-mediated organ damage partly caused by increased oxidative/nitrosative stress. Because of the extensive reviews on MDMA-mediated oxidative stress and tissue damage, we specifically focus on the mechanisms and consequences of oxidative-modifications of mitochondrial proteins, leading to mitochondrial dysfunction. We briefly describe a method to systematically identify oxidatively-modified mitochondrial proteins in control and MDMA-exposed rats by using biotin-N-maleimide (biotin-NM) as a sensitive probe for oxidized proteins. We also describe various applications and advantages of this Cys-targeted proteomics method and alternative approaches to overcome potential limitations of this method in studying oxidized proteins from MDMA-exposed tissues. Finally we discuss the mechanism of synergistic drug-interaction between MDMA and other abused substances including alcohol (ethanol) as well as application of this redox-based proteomics method in translational studies for developing effective preventive and therapeutic agents against MDMA-induced organ damage.

  20. Biomarkers of oxidative damage and antioxidant defense capacity in Caiman latirostris blood.

    PubMed

    Poletta, Gisela L; Simoniello, María Fernanda; Mudry, Marta D

    2016-01-01

    Several xenobiotics, and among them pesticides, can produce oxidative stress, providing a mechanistic basis for their observed toxicity. Chronic oxidative stress induces deleterious modifications to DNA, lipids and proteins that are used as effective biomarkers to study pollutant-mediated oxidative stress. No previous report existed on the application of oxidative damage and antioxidant defense biomarkers in Caiman latirostris blood, while few studies reported in other crocodilians were done in organs or muscles of dead animals. The aim of this study was to characterize a new set of oxidative stress biomarkers in C. latirostris blood, through the modification of conventional techniques: 1) damage to lipids by thiobarbituric acid reactive substances (TBARS), 2) damage to DNA by comet assay modified with the enzymes FPG and Endo III, and 3) antioxidant defenses: catalase, superoxide dismutase and glutathione; in order to apply them in future biomonitoring studies. We successfully adapted standard procedures for CAT, SOD, GSH and TBARS determination in C. latirostris blood. Calibration curves for FPG and Endo III showed that the three dilutions tested were appropriate to conduct the modified comet assay for the detection of oxidized bases in C. latirostris erythrocytes. One hour of incubation allowed a complete repair of the damage generated. The incorporation of these biomarkers in biomonitoring studies of caiman populations exposed to xenobiotics is highly important considering that this species has recovered from a serious endangered state through the implementation of sustainable use programs in Argentina, and represents nowadays a relevant economic resource for many human communities.

  1. Mechanisms of MDMA (Ecstasy)-Induced Oxidative Stress, Mitochondrial Dysfunction, and Organ Damage

    PubMed Central

    Song, Byoung-Joon; Moon, Kwan-Hoon; Upreti, Vijay V.; Eddington, Natalie D.; Lee, Insong J.

    2010-01-01

    Despite numerous reports about the acute and sub-chronic toxicities caused by MDMA (3,4-methylenedioxymethamphetamine, ecstasy), the underlying mechanism of organ damage is poorly understood. The aim of this review is to present an update of the mechanistic studies on MDMA-mediated organ damage partly caused by increased oxidative/nitrosative stress. Because of the extensive reviews on MDMA-mediated oxidative stress and tissue damage, we specifically focus on the mechanisms and consequences of oxidative-modifications of mitochondrial proteins, leading to mitochondrial dysfunction. We briefly describe a method to systematically identify oxidatively-modified mitochondrial proteins in control and MDMA-exposed rats by using biotin-N-maleimide (biotin-NM) as a sensitive probe for oxidized proteins. We also describe various applications and advantages of this Cys-targeted proteomics method and alternative approaches to overcome potential limitations of this method in studying oxidized proteins from MDMA-exposed tissues. Finally we discuss the mechanism of synergistic drug-interaction between MDMA and other abused substances including alcohol (ethanol) as well as application of this redox-based proteomics method in translational studies for developing effective preventive and therapeutic agents against MDMA-induced organ damage. PMID:20420575

  2. Neutrophil-derived ROS contribute to oxidative DNA damage induction by quartz particles.

    PubMed

    van Berlo, Damien; Wessels, Anton; Boots, Agnes W; Wilhelmi, Verena; Scherbart, Agnes M; Gerloff, Kirsten; van Schooten, Frederik J; Albrecht, Catrin; Schins, Roel P F

    2010-12-01

    The carcinogenicity of respirable quartz is considered to be driven by reactive oxygen species (ROS) generation in association with chronic inflammation. The contribution of phagocyte-derived ROS to inflammation, oxidative stress, and DNA damage responses was investigated in the lungs of C57BL/6J wild-type and p47(phox-/-) mice, 24h after pharyngeal aspiration of DQ12 quartz (100 mg/kg bw). Bone-marrow-derived neutrophils from wild-type and p47(phox-/-) mice were used for parallel in vitro investigations in coculture with A549 human alveolar epithelial cells. Quartz induced a marked neutrophil influx in both wild-type and p47(phox-/-) mouse lungs. Significant increases in mRNA expression of the oxidative stress markers HO-1 and γ-GCS were observed only in quartz-treated wild-type animals. Oxidative DNA damage in lung tissue was not affected by quartz exposure and did not differ between p47(phox-/-) and WT mice. Differences in mRNA expression of the DNA repair genes OGG1, APE-1, DNA Polβ, and XRCC1 were also absent. Quartz treatment of cocultures containing wild-type neutrophils, but not p47(phox-/-) neutrophils, caused increased oxidative DNA damage in epithelial cells. Our study demonstrates that neutrophil-derived ROS significantly contribute to pulmonary oxidative stress responses after acute quartz exposure, yet their role in the associated induction of oxidative DNA damage could be shown only in vitro.

  3. Exposure to 1800 MHz radiofrequency radiation induces oxidative damage to mitochondrial DNA in primary cultured neurons.

    PubMed

    Xu, Shangcheng; Zhou, Zhou; Zhang, Lei; Yu, Zhengping; Zhang, Wei; Wang, Yuan; Wang, Xubu; Li, Maoquan; Chen, Yang; Chen, Chunhai; He, Mindi; Zhang, Guangbin; Zhong, Min

    2010-01-22

    Increasing evidence indicates that oxidative stress may be involved in the adverse effects of radiofrequency (RF) radiation on the brain. Because mitochondrial DNA (mtDNA) defects are closely associated with various nervous system diseases and mtDNA is particularly susceptible to oxidative stress, the purpose of this study was to determine whether radiofrequency radiation can cause oxidative damage to mtDNA. In this study, we exposed primary cultured cortical neurons to pulsed RF electromagnetic fields at a frequency of 1800 MHz modulated by 217 Hz at an average special absorption rate (SAR) of 2 W/kg. At 24 h after exposure, we found that RF radiation induced a significant increase in the levels of 8-hydroxyguanine (8-OHdG), a common biomarker of DNA oxidative damage, in the mitochondria of neurons. Concomitant with this finding, the copy number of mtDNA and the levels of mitochondrial RNA (mtRNA) transcripts showed an obvious reduction after RF exposure. Each of these mtDNA disturbances could be reversed by pretreatment with melatonin, which is known to be an efficient antioxidant in the brain. Together, these results suggested that 1800 MHz RF radiation could cause oxidative damage to mtDNA in primary cultured neurons. Oxidative damage to mtDNA may account for the neurotoxicity of RF radiation in the brain.

  4. Antioxidant properties of xanthones from Calophyllum brasiliense: prevention of oxidative damage induced by FeSO4

    PubMed Central

    2013-01-01

    Background Reactive oxygen species (ROS) are important mediators in a number of degenerative diseases. Oxidative stress refers to the imbalance between the production of ROS and the ability to scavenge these species through endogenous antioxidant systems. Since antioxidants can inhibit oxidative processes, it becomes relevant to describe natural compounds with antioxidant properties which may be designed as therapies to decrease oxidative damage and stimulate endogenous cytoprotective systems. The present study tested the protective effect of two xanthones isolated from the heartwood of Calophyllum brasilienses against FeSO4-induced toxicity. Methods Through combinatory chemistry assays, we evaluated the superoxide (O2●—), hydroxyl radical (OH●), hydrogen peroxide (H2O2) and peroxynitrite (ONOO—) scavenging capacity of jacareubin (xanthone III) and 2-(3,3-dimethylallyl)-1,3,5,6-tetrahydroxyxanthone (xanthone V). The effect of these xanthones on murine DNA and bovine serum albumin degradation induced by an OH• generator system was also evaluated. Additionally, we investigated the effect of these xanthones on ROS production, lipid peroxidation and glutathione reductase (GR) activity in FeSO4-exposed brain, liver and lung rat homogenates. Results Xanthone V exhibited a better scavenging capacity for O2●—, ONOO- and OH● than xanthone III, although both xanthones were unable to trap H2O2. Additionally, xanthones III and V prevented the albumin and DNA degradation induced by the OH● generator system. Lipid peroxidation and ROS production evoked by FeSO4 were decreased by both xanthones in all tissues tested. Xanthones III and V also prevented the GR activity depletion induced by pro-oxidant activity only in the brain. Conclusions Altogether, the collected evidence suggests that xanthones can play a role as potential agents to attenuate the oxidative damage produced by different pro-oxidants. PMID:24119308

  5. DNA damage and oxidative stress induced by endosulfan exposure in zebrafish (Danio rerio).

    PubMed

    Shao, Bo; Zhu, Lusheng; Dong, Miao; Wang, Jun; Wang, Jinhua; Xie, Hui; Zhang, Qingming; Du, Zhongkun; Zhu, Shaoyuan

    2012-07-01

    Endosulfan (6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzo-dioxathiepin-3-oxide), an organochlorine pesticide, is prevalently used all around the world. It is considered to be a new candidate for the persistent organic pollutants group. Endosulfan residues in the environment may cause serious damage to ecosystems, especially in aquatic environments. The present study was conducted to investigate the effect of endosulfan on antioxidant enzymes [catalase (CAT) and superoxide dismutase (SOD)], reactive oxygen species (ROS) generation and DNA damage in zebrafish. Male and female zebrafish were separated and exposed to a control solution and four concentrations of endosulfan (0.01, 0.1, 1, and 10 μg L⁻¹) and were sampled after 7, 14, 21, and 28 days. It is noteworthy that the present research explored the correlation among the three indicators induced by endosulfan. Low endosulfan concentrations (0.01 μg L⁻¹) induced a slight increase of SOD and CAT activity, which kept ROS in a stable level. High endosulfan concentration (10 μg L⁻¹) induced excessive ROS production which exceeded the capacity of the cellular antioxidants and exhausted the enzyme including CAT and SOD. The DNA damage of zebrafish was evaluated by single-cell gel electrophoresis and was enhanced with increasing endosulfan concentration. In conclusion, the present study showed that endosulfan (0.01-10 μg L⁻¹) has toxic effects on zebrafish.

  6. High molecular weight hyaluronan decreases oxidative DNA damage induced by EDTA in human corneal epithelial cells

    PubMed Central

    Ye, J; Wu, H; Wu, Y; Wang, C; Zhang, H; Shi, X; Yang, J

    2012-01-01

    Purpose To investigate the toxic effects of ethylenediaminetetraacetic acid disodium salt (EDTA), a corneal penetration enhancer in topical ophthalmic formulations, on DNA in human corneal epithelial cells (HCEs), and to investigate whether the effect induced by EDTA can be inhibited by high molecular weight hyaluronan (HA). Methods Cells were exposed to EDTA in concentrations ranging from 0.00001 to 0.01% for 60 min, or 30 min high molecular weight HA pretreatment followed by EDTA treatment. The cell viability was measured by the MTT test. Cell apoptosis was determined with annexin V staining by flow cytometry. The DNA single- and double-strand breaks of HCEs were examined by alkaline comet assay and by immunofluorescence microscope detection of the phosphorylated form of histone variant H2AX (γH2AX) foci, respectively. Reactive oxygen species (ROS) production was assessed by the fluorescent probe, 2′, 7′-dichlorodihydrofluorescein diacetate. Results EDTA exhibited no adverse effect on cell viability and did not induce cell apoptosis in human corneal epithelial cells at concentrations lower than 0.01%. However, a significant increase of DNA single- and double-strand breaks was observed in a dose-dependent manner with all the concentrations of EDTA tested in HCEs. In addition, EDTA treatment led to elevated ROS generation. Moreover, 30 min preincubation with high molecular weight HA significantly decreased EDTA-induced ROS generation and DNA damage. Conclusions EDTA could induce DNA damage in HCEs, probably through oxidative stress. Furthermore, high molecular weight HA was an effective protective agent that had antioxidant properties and decreased DNA damage induced by EDTA. PMID:22595911

  7. Elimination of damaged mitochondria through mitophagy reduces mitochondrial oxidative stress and increases tolerance to trichothecenes.

    PubMed

    Bin-Umer, Mohamed Anwar; McLaughlin, John E; Butterly, Matthew S; McCormick, Susan; Tumer, Nilgun E

    2014-08-12

    Trichothecene mycotoxins are natural contaminants of small grain cereals and are encountered in the environment, posing a worldwide threat to human and animal health. Their mechanism of toxicity is poorly understood, and little is known about cellular protection mechanisms against trichothecenes. We previously identified inhibition of mitochondrial protein synthesis as a novel mechanism for trichothecene-induced cell death. To identify cellular functions involved in trichothecene resistance, we screened the Saccharomyces cerevisiae deletion library for increased sensitivity to nonlethal concentrations of trichothecin (Tcin) and identified 121 strains exhibiting higher sensitivity than the parental strain. The largest group of sensitive strains had significantly higher reactive oxygen species (ROS) levels relative to the parental strain. A dose-dependent increase in ROS levels was observed in the parental strain treated with different trichothecenes, but not in a petite version of the parental strain or in the presence of a mitochondrial membrane uncoupler, indicating that mitochondria are the main site of ROS production due to toxin exposure. Cytotoxicity of trichothecenes was alleviated after treatment of the parental strain and highly sensitive mutants with antioxidants, suggesting that oxidative stress contributes to trichothecene sensitivity. Cotreatment with rapamycin and trichothecenes reduced ROS levels and cytotoxicity in the parental strain relative to the trichothecene treatment alone, but not in mitophagy deficient mutants, suggesting that elimination of trichothecene-damaged mitochondria by mitophagy improves cell survival. These results reveal that increased mitophagy is a cellular protection mechanism against trichothecene-induced mitochondrial oxidative stress and a potential target for trichothecene resistance.

  8. Resveratrol ameliorates the oxidative damage induced by arsenic trioxide in the feline lung.

    PubMed

    Cheng, Yanyan; Xue, Jiangdong; Yao, Chunyu; Gao, Li; Ma, Dexing; Liu, Yan; Zhang, Zhigang

    2013-01-01

    The objective of this study was to evaluate the possible protection of resveratrol against lung injury induced by arsenic trioxide (As2O3). Twenty-four healthy Chinese Dragon Li cats of either sex were randomly divided into four groups: control (1 ml/kg physiological saline), As2O3 (1 mg/kg), resveratrol (3 mg/kg) and resveratrol (3 mg/kg) + As2O3 (1 mg/kg). The resveratrol + As2O3- treated group was given resveratrol 1 hr before As2O3 (1 mg/kg) administration. We found that pretreatment with resveratrol in a clinically comparable dose regimen can reversed the changes in morphological and biochemical parameters induced by As2O3 in the lung. Resveratrol treatment also upregulated the activities of antioxidant enzymes and attenuated As2O3-induced increases in reactive oxygen species, 8-hydroxydeoxyguanosine and malondialdehyde production in the lung. In addition, resveratrol attenuated the As2O3-induced reduction in the ratio of reduced glutathione to oxidized glutathione, the content of total glutathione and lung arsenic burden. These findings indicated that resveratrol can provide significant protection against As2O3-induced oxidative damage.

  9. Insulin, catecholamines, glucose and antioxidant enzymes in oxidative damage during different loads in healthy humans.

    PubMed

    Koska, J; Blazícek, P; Marko, M; Grna, J D; Kvetnanský, R; Vigas, M

    2000-01-01

    Exercise, insulin-induced hypoglycemia and oral glucose loads (50 g and 100 g) were used to compare the production of malondialdehyde and the activity of antioxidant enzymes in healthy subjects. Twenty male volunteers participated in the study. Exercise consisted of three consecutive work loads on a bicycle ergometer of graded intensity (1.5, 2.0, and 2.5 W/kg, 6 min each). Hypoglycemia was induced by insulin (Actrapid MC Novo, 0.1 IU/kg, i.v.). Oral administration of 50 g and 100 g of glucose was given to elevate plasma glucose. The activity of superoxide dismutase (SOD) was determined in red blood cells, whereas glutathione peroxidase (GSH-Px) activity was measured in whole blood. The concentration of malondialdehyde (MDA) was determined by HPLC, catecholamines were assessed radioenzymatically and glucose was measured by the glucose-oxidase method. Exercise increased MDA concentrations, GSH-Px and SOD activities as well as plasma noradrenaline and adrenaline levels. Insulin hypoglycemia increased plasma adrenaline levels, but the concentrations of MDA and the activities of GSH-Px and SOD were decreased. Hyperglycemia increased plasma MDA concentrations, but the activities of GSH-Px and SOD were significantly higher after a larger dose of glucose only. Plasma catecholamines were unchanged. These results indicate that the transient increase of plasma catecholamine and insulin concentrations did not induce oxidative damage, while glucose already in the low dose was an important triggering factor for oxidative stress.

  10. Preventive effect of safranal against oxidative damage in aged male rat brain

    PubMed Central

    Samarghandian, Saeed; Azimi-Nezhad, Mohsen; Samini, Fariborz

    2014-01-01

    An imbalance between production of reactive oxygen species (ROS) and its elimination by antioxidant defense system in the body has been implicated for causes of aging and neurodegenerative diseases. This study was design to assess the changes in activities of antioxidant enzymes (superoxide dismutase (SOD), glutathione-S-transferase (GST), catalase), lipid peroxidation and reduced glutathione (GSH) levels in the brain of 2, 10 and 20 month old rats, and to determine the effect of safranal on the status of selected oxidative stress indices in the 10 and 20 month old rats. The aged rats (10 and 20 months) were given intraperitoneal injections of safranal (0.5 mg/kg day) daily for one month. The results of this study demonstrated that aging caused significant increase in the level of lipid peroxidation as well decrease in the GSH level and activities of SOD and GST in the brain of aging rats. The results of this study showed that safranal ameliorated the increased lipid peroxidation level as well as decreased GSH content of the brain of 10 and 20 month old rats. In addition, safranal treatment to the 20 month old rats, which restored the SOD and GST activities. In conclusion, safranal can be effective to protect susceptible aged brain from oxidative damage by increasing antioxidant defenses. PMID:25312506

  11. Oxidative damage in keratinocytes exposed to cigarette smoke and aldehydes.

    PubMed

    Avezov, Katia; Reznick, Abraham Z; Aizenbud, Dror

    2014-06-01

    Cigarette smoke (CS) is a significant environmental source of human exposure to chemically active saturated (acetaldehyde) and α,β-unsaturated aldehydes (acrolein) inducing protein carbonylation and dysfunction. The exposure of oral tissues to environmental hazards is immense, especially in smokers. The objectives of the current study were to examine the effect of aldehydes originating from CS on intracellular proteins of oral keratinocytes and to observe the antioxidant response in these cells. Intracellular protein carbonyl modification under CS, acrolein and acetaldehyde exposure in the HaCaT keratinocyte cell line, representing oral keratinocytes was examined by Western blot. Possible intracellular enzymatic dysfunction under the above conditions was examined by lactate dehydrogenase (LDH) activity assay. Oxidative stress response was investigated, by DCF (2,7-dichlorodihydrofluorescein) assay and GSH (glutathione) oxidation. Intracellular protein carbonyls increased 5.2 times after CS exposure and 2.7 times after exposure to 1 μmol of acrolein. DCF assay revealed an increase of fluorescence intensity 3.2 and 3.1 times after CS and acrolein exposure, respectively. CS caused a 72.5% decrease in intracellular GSH levels compared to controls. Activity of intracellular LDH was preserved. α,β-Unsaturated aldehydes from CS are capable of intracellular protein carbonylation and have a role in intracellular oxidative stress elevation in keratinocytes, probably due to the reduction in GSH levels.

  12. Diversity of endurance training effects on antioxidant defenses and oxidative damage in different brain regions of adolescent male rats.

    PubMed

    Chalimoniuk, M; Jagsz, S; Sadowska-Krepa, E; Chrapusta, S J; Klapcinska, B; Langfort, J

    2015-08-01

    Studies on the effect of physical activity on brain oxidative stress, performed mostly in adult rats, have shown that moderate aerobic activity increases resistance to oxidative stress and reduces cellular damage. These effects can greatly differ between various brain regions. The postnatal period of the highest brain sensitivity to various stimuli is adolescence. We hypothesized that endurance training will modify brain antioxidant barrier differently in various regions, depending on their role in locomotion. Therefore, we studied the effect of moderate intensity endurance training on the activities of selected antioxidant enzymes (superoxide dismutase, gluthathione peroxidase and catalase and the contents of thiobarbituric acid-reactive substances (the key index of lipid peroxidation) and glutathione in several brain regions with dissimilar relationship to locomotion, as well as in circulating blood. Additionally, we investigated the effect of the training on nitric oxide synthase activity that may be a major player in exercise-related oxidative stress in brain regions that are directly involved in the locomotion control and execution (the striatum, midbrain and cerebellum). The training significantly enhanced nitric oxide synthase activity only in the latter three regions. Surprisingly, it elevated the activities of all studied antioxidant enzymes (excepting gluthathione peroxidase) in the neocortex, while no appreciable change in these activities was found in either the cerebellum (except for elevated catalase activity), or the striatum, or the midbrain. The training also elevated total glutathione content (a key protector of brain proteins under the conditions of enhanced nitric oxide production) in the cerebellum and striatum, but not in the other regions. The observed brain changes greatly differed from those in circulating blood and did not prevent the training-related increases in oxidative damage as evidenced by elevations in cerebellar and striatal

  13. Fission product behavior during the PBF (Power Burst Facility) Severe Fuel Damage Test 1-1

    SciTech Connect

    Hartwell, J K; Petti, D A; Hagrman, D L; Jensen, S M; Cronenberg, A W

    1987-05-01

    In response to the accident at Three Mile Island Unit 2 (TMI-2), the United States Nuclear Regulatory Commission (USNRC) initiated a series of Severe Fuel Damage tests that were performed in the Power Burst Facility at the Idaho National Engineering Laboratory to obtain data necessary to understand (a) fission product release, transport, and deposition; (b) hydrogen generation; and (c) fuel/cladding material behavior during degraded core accidents. Data are presented about fission product behavior noted during the second experiment of this series, the Severe Fuel Damage Test 1-1, with an in-depth analysis of the fission product release, transport, and deposition phenomena that were observed. Real-time release and transport data of certain fission products were obtained from on-line gamma spectroscopy measurements. Liquid and gas effluent grab samples were collected at selected periods during the test transient. Additional information was obtained from steamline deposition analysis. From these and other data, fission product release rates and total release fractions are estimated and compared with predicted release behavior using current models. Fission product distributions and a mass balance are also summarized, and certain probable chemical forms are predicted for iodine, cesium, and tellurium. An in-depth evaluation of phenomena affecting the behavior of the high-volatility fission products - xenon, krypton, iodine, cesium, and tellurium - is presented. Analysis indicates that volatile release from fuel is strongly influenced by parameters other than fuel temperature. Fission product behavior during transport through the Power Burst Facility effluent line to the fission product monitoring system is assessed. Tellurium release behavior is also examined relatve to the extent of Zircaloy cladding oxidation. 81 fig., 53 tabs.

  14. Reduction of nitric oxide and DNA/RNA oxidation products are associated with active disease in systemic lupus erythematosus patients.

    PubMed

    Iriyoda, T M V; Stadtlober, N; Lozovoy, M A B; Delongui, F; Costa, N T; Reiche, E M V; Dichi, I; Simão, A N C

    2017-09-01

    The aims of the present study were to evaluate biomarkers of oxidative and nitrosative stress in systemic lupus erythematosus (SLE) patients, in particular products of DNA/RNA oxidative damage and their correlation with disease activity. This study included 188 controls and 203 patients; 153 with inactive SLE (SLEDAI < 6) and 50 with active SLE (SLEDAI ≥ 6) without renal impairment. Oxidative stress was assessed by tert-butyl hydroperoxide-initiated by chemiluminescence, advanced oxidation protein products (AOPP), total radical-trapping antioxidant parameter (TRAP), nitric oxide metabolites (NOx), and DNA/RNA oxidation products. Patients with SLE showed increased oxidative stress, as demonstrated by the augmentation of lipid hydroperoxides ( p < 0.0001) and AOPP ( p < 0.001) and reduced total antioxidant capacity ( p < 0.0001), without differences between patients with active disease and in remission. NOx levels and DNA/RNA oxidation products were inversely and independently associated with disease activity ( p < 0.0001 and p = 0.021, respectively), regardless of BMI and prednisone use. The linear regression analysis showed that about 5% of the SLEDAI score can be explained by the levels of DNA/RNA oxidation products ( r(2):0.051; p = 0.002) and about 9% of this score by the levels of NOx ( r(2):0.091; p < 0.0001). This study provides evidence for an inverse association between serum NOx levels and DNA/RNA oxidation products and SLE disease activity, suggesting that oxidative/nitrosative stress markers may be useful in evaluating SLE disease activity and progression of the disease.

  15. Roles of oxidative stress in synchrotron radiation X-ray-induced testicular damage of rodents

    PubMed Central

    Ma, Yingxin; Nie, Hui; Sheng, Caibin; Chen, Heyu; Wang, Ban; Liu, Tengyuan; Shao, Jiaxiang; He, Xin; Zhang, Tingting; Zheng, Chaobo; Xia, Weiliang; Ying, Weihai

    2012-01-01

    Synchrotron radiation (SR) X-ray has characteristic properties such as coherence and high photon flux, which has excellent potential for its applications in medical imaging and cancer treatment. However, there is little information regarding the mechanisms underlying the damaging effects of SR X-ray on biological tissues. Oxidative stress plays an important role in the tissue damage induced by conventional X-ray, while the role of oxidative stress in the tissue injury induced by SR X-ray remains unknown. In this study we used the male gonads of rats as a model to study the roles of oxidative stress in SR X-ray-induced tissue damage. Exposures of the testes to SR X-ray at various radiation doses did not significantly increase the lipid peroxidation of the tissues, assessed at one day after the irradiation. No significant decreases in the levels of GSH or total antioxidation capacity were found in the SR X-ray-irradiated testes. However, the SR X-ray at 40 Gy induced a marked increase in phosphorylated H2AX – a marker of double-strand DNA damage, which was significantly decreased by the antioxidant N-acetyl cysteine (NAC). NAC also attenuated the SR X-ray-induced decreases in the cell layer number of seminiferous tubules. Collectively, our observations have provided the first characterization of SR X-ray-induced oxidative damage of biological tissues: SR X-ray at high doses can induce DNA damage and certain tissue damage during the acute phase of the irradiation, at least partially by generating oxidative stress. However, SR X-ray of various radiation doses did not increase lipid peroxidation. PMID:22837810

  16. Elevated levels of urinary markers of oxidatively generated DNA and RNA damage in bipolar disorder.

    PubMed

    Munkholm, Klaus; Poulsen, Henrik Enghusen; Kessing, Lars Vedel; Vinberg, Maj

    2015-05-01

    The pathophysiological mechanisms underlying bipolar disorder and its multi-system nature are unclear. Oxidatively generated damage to nucleosides has been demonstrated in metabolic disorders; however, the extent to which this occurs in bipolar disorder in vivo is unknown. We investigated oxidatively generated damage to DNA and RNA in patients with bipolar disorder and its relationship with the affective phase compared with healthy control subjects. Urinary excretion of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydroguanosine (8-oxoGuo), markers of oxidatively generated DNA and RNA damage, respectively, was measured in 37 rapid cycling patients with bipolar disorder and in 40 age- and gender-matched healthy control subjects. Employing a longitudinal design, repeated measurements of both markers were evaluated in various affective phases in patients with bipolar disorder during a six- to 12-month period and compared with repeated measurements in healthy control subjects. In linear mixed models, adjusting for demographical, metabolic, and lifestyle factors, the excretion of 8-oxodG and 8-oxoGuo was significantly elevated in euthymic patients with bipolar disorder compared with healthy control subjects, with increases of 40% (p < 0.0005) and 43% (p < 0.0005), respectively. The increased oxidatively generated nucleoside damage was present through all affective phases of the illness, with no significant difference between affective states. Our results indicate that bipolar disorder is associated with increased oxidatively generated damage to nucleosides. The findings could suggest a role for oxidatively generated damage to DNA and RNA as a molecular mechanism contributing to the increased risk of medical disorders, shortened life expectancy, and the progressive course of illness observed in bipolar disorder. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Oxidative DNA damage induced by activation of polychlorinated biphenyls (PCBs): implications for PCB-induced oxidative stress in breast cancer.

    PubMed

    Oakley, G G; Devanaboyina, U; Robertson, L W; Gupta, R C

    1996-12-01

    We have previously reported that mono- and dichlorinated biphenyls (PCBs) can be metabolized to dihydroxy compounds and further oxidized to reactive metabolites which form adducts with nitrogen and sulfur nucleophiles including DNA [Amaro et al. (1966) Chem. Res. Toxicol. 9, 623-629; Oakley et al. (1996) Carcinogenesis 17, 109-114]. The former studies also demonstrated that during the metabolism of PCBs superoxide may be produced. We have therefore examined the abilities of PCB metabolites to induce free radical-mediated oxidative DNA damage using a newly developed, highly sensitive, 32P-postlabeling assay for 8-oxode-oxyguanosine (8-oxodG) [Devanaboyina, U., and Gupta, R. (1996) Carcinogenesis 17, 917-924]. The incubation of 3,4-dichloro-2'5'-dihydroxybiphenyl (100 microM) with calf thymus DNA (300 micrograms/microL) in the presence of the breast tissue and milk-associated enzyme, lactoperoxidase (10 mU/mL), and H2O2 (0.5 mM) resulted in a significant increase in free radical-induced DNA damage (253 8-oxodG/10(6) nucleotides) as compared to vehicle-treated DNA (118 8-oxodG/10(6) nucleotides). Substituting CuCl(2) (100 microM) for lactoperoxidase/H2O2, however, resulted in a substantial increase in 8-oxodG content (2669 8-oxodG/10(6) nucleotides). FeCl(3) was ineffective, suggesting that CuCl(2) but not FeCl(3) mediates oxidation of PCB dihydroxy metabolites, resulting in oxidative DNA damage. The addition of catalase (100 U/mL) and sodium azide (0.1 M) reduced the effect of CuCl(2) (849 and 896 8-oxodG/10(6) nucleotides, respectively), while superoxide dismutase (600 U/mL) moderately stimulated and glutathione (100 microM) substantially stimulated 8-oxodG formation (3014 and 4415 8-oxodG/10(6) nucleotides, respectively). The effect of various buffers as well as the effects of PCB structure on Cu(II)-mediated oxidative DNA damage were examined. These results demonstrate that free radicals and oxidative DNA damage are produced during oxidation of lower chlorinated

  18. Product analysis of partial discharge damage to oil-impregnated insulation paper

    NASA Astrophysics Data System (ADS)

    Yan, Jiaming; Liao, Ruijin; Yang, Lijun; Li, Jian; Liu, Bin

    2011-04-01

    Surface products of oil-impregnated insulation paper during the damage process caused by partial discharge (PD), as well as gas within the cavity, were studied. An optical microscope and a scanning electron microscope (SEM) were used to investigate surface morphology, while an infrared spectroscopy (IR) and an X-ray photoelectron spectroscopy (XPS) were used to study surface products and their components. The volume variation in cavity gas was also analyzed. Furthermore, gas constituents and their relevant contents were studied using a gas chromatography-mass spectrometer (GC-MS). The study results reveal the following: during the PD damage process, the total gas volume and the content of electronegative gasses alternately decline and increase, while discharge types alternate between pulse type and pseudo-glow type (or glow type); “surface droplets” and “crystalline solids” appear on the insulation surface one after another; surface droplets mainly consist of (Cdbnd O)-group-containing compounds, whereas crystalline solids are mainly carboxylic acids, with carboxyl groups also found in cellulose chains; and the discharge type related to the oxidization of decomposition products is the main factor that determines the state (liquid or solid) of the surface products.

  19. The beetroot component betanin modulates ROS production, DNA damage and apoptosis in human polymorphonuclear neutrophils.

    PubMed

    Zielińska-Przyjemska, Małgorzata; Olejnik, Anna; Kostrzewa, Artur; Łuczak, Michał; Jagodziński, Paweł P; Baer-Dubowska, Wanda

    2012-06-01

    The aim of this study was to evaluate the effect of betanin, one of the beetroot major components, on ROS production, DNA damage and apoptosis in human resting and stimulated with phorbol 12-myristate13-acetate polymorphonuclear neutrophils, one of the key elements of the inflammatory response. Incubation of neutrophils with betanin in the concentration range 2-500 µM resulted in significant inhibition of ROS production (by 15-46%, depending on the ROS detection assay). The antioxidant capacity of betanin was most prominently expressed in the chemiluminescence measurements. This compound decreased also the percentage of DNA in comet tails in stimulated neutrophils, but only at the 24 h time point. In resting neutrophils an increased level of DNA in comet tails was observed. Betanin did not affect the activity of caspase-3, in resting neutrophils, but significantly enhanced the enzyme activity in stimulated neutrophils. The western blot analysis showed, however, an increased level of caspase-3 cleavage products as a result of betanin treatment both in resting and stimulated neutrophils. The results indicate that betanin may be responsible for the effect of beetroot products on neutrophil oxidative metabolism and its consequences, DNA damage and apoptosis. The dose and time dependent effects on these processes require further studies.

  20. Age-Dependent Oxidative DNA Damage Does Not Correlate with Reduced Proliferation of Cardiomyocytes in Humans

    PubMed Central

    Li, Minghui; Liu, Jinfen; Jiang, Chuan; Zhang, Haibo; Ye, Lincai; Zheng, Jinghao

    2017-01-01

    Background Postnatal human cardiomyocyte proliferation declines rapidly with age, which has been suggested to be correlated with increases in oxidative DNA damage in mice and plays an important role in regulating cardiomyocyte proliferation. However, the relationship between oxidative DNA damage and age in humans is unclear. Methods Sixty right ventricular outflow myocardial tissue specimens were obtained from ventricular septal defect infant patients during routine congenital cardiac surgery. These specimens were divided into three groups based on age: group A (age 0–6 months), group B (age, 7–12 months), and group C (>12 months). Each tissue specimen was subjected to DNA extraction, RNA extraction, and immunofluorescence. Results Immunofluorescence and qRT-PCR analysis revealed that DNA damage markers—mitochondrial DNA copy number, oxoguanine 8, and phosphorylated ataxia telangiectasia mutated—were highest in Group B. However immunofluorescence and qRT-PCR demonstrated that two cell proliferation markers, Ki67 and cyclin D2, were decreased with age. In addition, wheat germ agglutinin-staining indicated that the average size of cardiomyocytes increased with age. Conclusions Oxidative