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Sample records for hydrogen peroxide induced

  1. Hydrogen peroxide-induced apoptosis in human gingival fibroblasts

    PubMed Central

    Gutiérrez-Venegas, Gloria; Guadarrama-Solís, Adriana; Muñoz-Seca, Carmen; Arreguín-Cano, Juan Antonio

    2015-01-01

    In the process of bleaching vital, discolored teeth, low concentrations of hydrogen peroxide (H2O2) are effective alternatives to heat-activated 30% H2O2. However, interest has been expressed in the assessment of pathological effects of long-term exposure to bleaching agents such as irritation and ulceration of the gingival or other soft tissues. The aim of the present study was to determine the effect of hydrogen peroxide on apoptosis in human gingival fibroblasts (HGF). Cytochrome c, Bcl-2, Bax, Bid and caspase-3 protein expression were detected by Western blotting. HGF cell apoptosis induced by H2O2 was both dose and time dependent. The addition of H2O2 resulted in the release of cytochrome c to the cytosol, and an increase of Caspase-3 cleavage. Data suggest that oxidative stress-induced apoptosis in HGF is intrinsic pathway involved the release of apoptotic signal from mitochondria. PMID:26884825

  2. UV-induced synthesis of hydrogen peroxide

    SciTech Connect

    Murphy, T.M.; Huerta, A.J. )

    1989-04-01

    Suspension-cultured rose cells irradiated with UV (254 mm, 558 J m{sup {minus}2}) showed a transient efflux of K{sup +}, and a production of H{sub 2}O{sub 2} measured by chemiluminescence of luminol in the presence of peroxidase. The peak concentration of H{sub 2}O{sub 2}, attained at about 60-90 min after irradiation, was 2-5 uM. The addition of superoxide dismutase to irradiated cells stimulated luminscence, suggesting that the H{sub 2}O{sub 2} came at least in part from superoxide that was present in the extracellular medium. Treatments that inhibited the UV-induced efflux of K{sup +} also inhibited the appearance of H{sub 2}O{sub 2}, though the converse was not always true, suggesting that K{sup +} efflux was necessary for H{sub 2}O{sub 2} synthesis, but not vice-versa. H{sub 2}O{sub 2} in the extracellular space is required for lignin synthesis in many plant tissues. Phenolic compounds, the other substrates for lignin, are induced by UV. We suggest that the UV-stimulated production of H{sub 2}O{sub 2} is part of a coordinated induction of lignin synthesis.

  3. Hydrogen peroxide poisoning

    MedlinePlus

    ... peroxide is used in these products: Hydrogen peroxide Hair bleach Some contact lens cleaners Note: Household hydrogen peroxide ... it contains 97% water and 3% hydrogen peroxide. Hair bleaches are stronger. They usually have a concentration of ...

  4. Salidroside inhibits endogenous hydrogen peroxide induced cytotoxicity of endothelial cells.

    PubMed

    Zhao, Xingyu; Jin, Lianhai; Shen, Nan; Xu, Bin; Zhang, Wei; Zhu, Hongli; Luo, Zhengli

    2013-01-01

    Salidroside, a phenylpropanoid glycoside isolated from Rhodiola rosea L., shows potent antioxidant property. Herein, we investigated the protective effects of salidroside against hydrogen peroxide (H2O2)-induced oxidative damage in human endothelial cells (EVC-304). EVC-304 cells were incubated in the presence or absence of low steady states of H2O2 (3-4 µM) generated by glucose oxidase (GOX) with or without salidroside. 3(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione (GSH) assays were performed, together with Hoechst 33258 staining and flow cytometric analysis using Annexin-V and propidium iodide (PI) label. The results indicated that salidroside pretreatment attenuated endogenous H2O2 induced apoptotic cell death in EVC-304 cells in a dose-dependent pattern. Furthermore, Western blot data revealed that salidroside inhibited activation of caspase-3, 9 and cleavage of poly(ADP-ribose) polymerase (PARP) induced by endogenous H2O2. It also decreased the expression of Bax and rescued the balance of pro- and anti-apoptotic proteins. All these results demonstrated that salidroside may present a potential therapy for oxidative stress in cardiovascular and cerebrovascular diseases.

  5. Hydrogen peroxide-induced chemotaxis of mouse peritoneal neutrophils.

    PubMed

    Klyubin, I V; Kirpichnikova, K M; Gamaley, I A

    1996-08-01

    Directed locomotion of mouse peritoneal neutrophils under agarose was studied, and activity of hydrogen peroxide (H2O2) as a chemoattractant was tested in its concentration range of 10(-6) to 10(-3) M. It has been found that H2O2 at low concentrations (about 10 microM) induces chemotactic activity. This activity was not affected by the presence of serum in the agarose medium. Use of bovine serum albumin instead of the heat-inactivated bovine serum in the medium had no effect on cell locomotion. The H2O2-induced chemotaxis was significantly reduced by catalase. Involvement of [Ca2+]i transients in the H2O2-induced chemotactic response was shown. These data indicate that H2O2 itself in small quantities can act as a chemoattractant without interacting with a plasma precursor to form a chemotactic factor. It has been suggested that H2O2 may form an important link similar to the second messenger in communication between the cells.

  6. Hydrogen peroxide induces apoptosis via a mitochondrial pathway in chondrocytes

    NASA Astrophysics Data System (ADS)

    Zhuang, Cai-ping; Liang, Qian; Wang, Xiao-ping; Chen, Tong-sheng

    2012-03-01

    The degenerative joint disease such as osteoarthritis (OA) is closely associated with the death of chondrocytes in apoptosis fashion. Hydrogen peroxide (H2O2), higher expression following acute damage in OA patients, has been shown to be up-regulated during apoptosis in a bulk of experimental models. This study was aimed to explore the mechanism of H2O2-induced rabbit chondrocytes apoptosis. Articular cartilage was biopsied from the joints of 6 weeks old New Zealand rabbits. Cell Counting Kit (CCK-8) assay was used to assess the inhibitory effect of H2O2 on cell viability. H2O2 treatment induced a remarkable reduction of cell viability. We used flow cytometry to assess the form of cell death with Annexin-V/PI double staining, and found that H2O2 treatment induced apoptosis in a dose-and time-dependent manner. Exposure of chondrocytes to 1.5 mM of H2O2 for 2 h induced a burst apoptosis that can be alleviated by N-acetyl cysteine (NAC) pretreatment, an anti-oxidant amino-acid derivative. Loss of mitochondria membrane potential (▵Ψm) was evaluated using confocal microscopy imaging and flow cytometry (FCM). H2O2 treatment induced a marked reduction of ▵Ψm, and the abrupt disappearance of ▵Ψm occurred within 5 minutes. These results indicate that H2O2 induces a rapid apoptosis via a mitochondrial pathway in rabbit chondrocytes.

  7. Hydrogen Peroxide-Induced Akt Phosphorylation Regulates Bax Activation

    PubMed Central

    Sadidi, Mahdieh; Lentz, Stephen I.; Feldman, Eva L.

    2009-01-01

    Reactive oxygen species such as hydrogen peroxide (H2O2) are involved in many cellular processes that positively and negatively regulate cell fate. H2O2, acting as an intracellular messenger, activates phosphatidylinositol-3 kinase (PI3K) and its downstream target Akt, and promotes cell survival. The aim of the current study was to understand the mechanism by which PI3K/Akt signaling promotes survival in SH-SY5Y neuroblastoma cells. We demonstrate that PI3K/Akt mediates phosphorylation of the pro-apoptotic Bcl-2 family member Bax. This phosphorylation suppresses apoptosis and promotes cell survival. Increased survival in the presence of H2O2 was blocked by LY294002, an inhibitor of PI3K activation. LY294002 prevented Bax phosphorylation and resulted in Bax translocation to the mitochondria, cytochrome c release, caspase-3 activation, and cell death. Collectively, these findings reveal a mechanism by which H2O2-induced activation of PI3K/Akt influences posttranslational modification of Bax and inactivate a key component of the cell death machinery. PMID:19278624

  8. Hydrogen peroxide-induced necrotic cell death in cardiomyocytes is independent of matrix metalloproteinase-2.

    PubMed

    Ali, Mohammad A M; Kandasamy, Arulmozhi D; Fan, Xiaohu; Schulz, Richard

    2013-09-01

    Matrix metalloproteinase-2 (MMP-2) is well known to proteolyse both extracellular and intracellular proteins. Reactive oxygen species activate MMP-2 at both transcriptional and post-translational levels, thus MMP-2 activation is considered an early event in oxidative stress injury. Although hydrogen peroxide is widely used to trigger oxidative stress-induced cell death, the type of cell death (apoptosis vs. necrosis) in cardiomyocytes is still controversial depending on the concentration used and the exposure time. We carefully investigated the mode of cell death in neonatal rat cardiomyocytes induced by different concentrations (50-500 μM) of hydrogen peroxide at various time intervals after exposure and determined whether MMP-2 is implicated in hydrogen peroxide-induced cardiomyocyte death. Treating cardiomyocytes with hydrogen peroxide led to elevated MMP-2 level/activity with maximal effects seen at 200 μM. Hydrogen peroxide caused necrotic cell death by disrupting the plasmalemma as evidenced by the release of lactate dehydrogenase in a concentration- and time-dependent manner as well as the necrotic cleavage of PARP-1. The absence of both caspase-3 cleavage/activation and apoptotic cleavage of PARP-1 illustrated the weak contribution of apoptosis. Pre-treatment with selective MMP inhibitors did not protect against hydrogen peroxide-induced necrosis. In conclusion hydrogen peroxide increases MMP-2 level/activity in cardiomyocytes and induces necrotic cell death, however, the later effect is MMP-2 independent.

  9. Concentration of Hydrogen Peroxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2006-01-01

    Methods for concentrating hydrogen peroxide solutions have been described. The methods utilize a polymeric membrane separating a hydrogen peroxide solution from a sweep gas or permeate. The membrane is selective to the permeability of water over the permeability of hydrogen peroxide, thereby facilitating the concentration of the hydrogen peroxide solution through the transport of water through the membrane to the permeate. By utilizing methods in accordance with the invention, hydrogen peroxide solutions of up to 85% by volume or higher may be generated at a point of use without storing substantial quantities of the highly concentrated solutions and without requiring temperatures that would produce explosive mixtures of hydrogen peroxide vapors.

  10. Hydrogen peroxide induces microvilli on human retinal pigment epithelial cells in culture.

    PubMed

    Reid, G G; Edwards, J G; Marshall, G E; Sutcliffe, R G; Lee, W R

    1995-02-01

    We have found that hydrogen peroxide (10(-4)-10(-2) M) rapidly induces microvilli on separate cells and confluent sheets of human retinal pigment epithelium in culture. t-butyl hydroperoxide and sodium arsenite do not induce microvilli. A role for hydrogen peroxide as an intercellular messenger has previously been proposed in the inflammatory response, in which hydrogen peroxide from phagocytes may signal to vascular endothelial cells. Our observations thus provide a second example of the induction of what may be a physiological response by this potentially toxic agent. In the retina, hydrogen peroxide released from illuminated photoreceptors may elongate the microvilli which extend into the spaces between them. Increased numbers of microvilli and their protrusion further into the photoreceptor layer may enhance various interactions between the two cell types, including the antioxidant functions of the epithelium.

  11. Reduction of hydrogen peroxide-induced erythrocyte damage by Carica papaya leaf extract

    PubMed Central

    Okoko, Tebekeme; Ere, Diepreye

    2012-01-01

    Objective To investigate the in vitro antioxidant potential of Carica papaya (C. papaya) leaf extract and its effect on hydrogen peroxide-induced erythrocyte damage assessed by haemolysis and lipid peroxidation. Methods Hydroxyl radical scavenging activities, hydrogen ion scavenging activity, metal chelating activity, and the ferrous ion reducing ability were assessed as antioxidant indices. In the other experiment, human erythrocytes were treated with hydrogen peroxide to induce erythrocyte damage. The extract (at various concentrations) was subsequently incubated with the erythrocytes and later analysed for haemolysis and lipid peroxidation as indices for erythrocyte damage. Results Preliminary investigation of the extract showed that the leaf possessed significant antioxidant and free radical scavenging abilities using in vitro models in a concentration dependent manner (P<0.05). The extract also reduced hydrogen peroxide induced erythrocyte haemolysis and lipid peroxidation significantly when compared with ascorbic acid (P<0.05). The IC50 values were 7.33 mg/mL and 1.58 mg/mL for inhibition of haemolysis and lipid peroxidation, respectively. In all cases, ascorbic acid (the reference antioxidant) possessed higher activity than the extract. Conclusions The findings show that C. papaya leaves possess significant bioactive potential which is attributed to the phytochemicals which act in synergy. Thus, the leaves can be exploited for pharmaceutical and nutritional purposes. PMID:23569948

  12. Carbon Sources for Yeast Growth as a Precondition of Hydrogen Peroxide Induced Hormetic Phenotype.

    PubMed

    Vasylkovska, Ruslana; Petriv, Natalia; Semchyshyn, Halyna

    2015-01-01

    Hormesis is a phenomenon of particular interest in biology, medicine, pharmacology, and toxicology. In this study, we investigated the relationship between H2O2-induced hormetic response in S. cerevisiae and carbon sources in yeast growth medium. In general, our data indicate that (i) hydrogen peroxide induces hormesis in a concentration-dependent manner; (ii) the effect of hydrogen peroxide on yeast reproductive ability depends on the type of carbon substrate in growth medium; and (iii) metabolic and growth rates as well as catalase activity play an important role in H2O2-induced hormetic response in yeast. PMID:26843865

  13. Protection against hydrogen peroxide induced oxidative damage in rat erythrocytes by Mangifera indica L. peel extract.

    PubMed

    Ajila, C M; Prasada Rao, U J S

    2008-01-01

    Phytochemicals such as polyphenols and carotenoids are gaining importance because of their contribution to human health and their multiple biological effects such as antioxidant, antimutagenic, anticarcinogenic and cytoprotective activities and other therapeutic properties. Mango peel is a major by-product in pulp industry and it contains various bioactive compounds like polyphenols, carotenoids and others. In the present study, the protective effect of peel extracts of unripe and ripe mango fruits of two varieties namely, Raspuri and Badami on hydrogen peroxide induced hemolysis, lipid peroxidation, degradation of membrane proteins and its morphological changes are reported. The oxidative hemolysis of rat erythrocytes by hydrogen peroxide was inhibited by mango peel extract in a dose dependent manner. The IC(50) value for lipid peroxidation inhibition on erythrocyte ghost membrane was found to be in the range of 4.5-19.3 microg gallic acid equivalents. The mango peel extract showed protection against membrane protein degradation caused by hydrogen peroxide. Morphological changes to erythrocyte membrane caused by hydrogen peroxide were protected by mango peel extract. The results demonstrated that mango peel extracts protected erythrocytes against oxidative stress and may impart health benefits and it could be used as a valuable food ingredient or a nutraceutical product.

  14. Hydrogen Peroxide Concentrator

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F.

    2007-01-01

    A relatively simple and economical process and apparatus for concentrating hydrogen peroxide from aqueous solution at the point of use have been invented. The heart of the apparatus is a vessel comprising an outer shell containing tubular membranes made of a polymer that is significantly more permeable by water than by hydrogen peroxide. The aqueous solution of hydrogen peroxide to be concentrated is fed through the interstitial spaces between the tubular membranes. An initially dry sweep gas is pumped through the interiors of the tubular membranes. Water diffuses through the membranes and is carried away as water vapor mixed into the sweep gas. Because of the removal of water, the hydrogen peroxide solution flowing from the vessel at the outlet end is more concentrated than that fed into the vessel at the inlet end. The sweep gas can be air, nitrogen, or any other gas that can be conveniently supplied in dry form and does not react chemically with hydrogen peroxide.

  15. Baicalein Decreases Hydrogen Peroxide-Induced Damage to NG108-15 Cells via Upregulation of Nrf2.

    PubMed

    Yeh, Chao-Hung; Ma, Kuo-Hsing; Liu, Pei-Shan; Kuo, Jung-Kuei; Chueh, Sheau-Huei

    2015-08-01

    Baicalein is a flavonoid inhibitor of 12-lipoxygenase. Here, we investigated its effect on hydrogen peroxide-induced damage to NG108-15 cells. Hydrogen peroxide activated the mitochondrial apoptotic pathway, decreased Nrf2 expression, increased reactive oxygen species (ROS) levels, reduced viability, and increased cell death after 2-24 h treatment of NG108-15 cells. Co-treatment with hydrogen peroxide and baicalein completely suppressed the activation of mitochondrial apoptotic pathway by upregulating Nrf2 expression and reducing ROS stress and partially inhibited the effects on cell viability and cell death. Silencing of 12-lipoxygenase had a similar protective effect to baicalein on hydrogen peroxide-induced damage by blocking the hydrogen peroxide-induced decrease in Nrf2 expression and increase in ROS levels. Neither protective effect was altered by addition of 12-hydroxyeicosatetraenoic acid, the product of 12-lipoxygenase, suggesting that hydrogen peroxide induced damage via 12-lipoxygenase by another, as yet unknown, mechanism, rather than activating it. Co-treatment of cells with hydrogen peroxide and N-acetylcysteine or the Nrf2 inducer sulforaphane reduced hydrogen peroxide-induced damage in a similar fashion to baicalein, while the Nrf2 inhibitor retinoic acid blocked the protective effect of baicalein. Silencing Nrf2 also inhibited the protective effects of baicalein, sulforaphane, and N-acetylcysteine and resulted in high ROS levels, suggesting ROS elimination was mediated by Nrf2. Taken together our results suggest that baicalein protects cells from hydrogen peroxide-induced activation of the mitochondrial apoptotic pathway by upregulating Nrf2 and inhibiting 12-lipoxygenase to block the increase in ROS levels. Hydrogen peroxide also activates a second mitochondrial dysfunction independent death pathway which is resistant to baicalein.

  16. Preparation of hydrogen peroxide

    SciTech Connect

    Brill, W.F.

    1984-07-31

    Hydrogen peroxide is produced in a reaction between carbon monoxide, oxygen, and water in the presence of a solvent using a Group 8 noble metal as a catalyst. Especially preferred as the working solution is palladium chloride in acetone.

  17. Hydrogen peroxide poisoning.

    PubMed

    Watt, Barbara E; Proudfoot, Alex T; Vale, J Allister

    2004-01-01

    Hydrogen peroxide is an oxidising agent that is used in a number of household products, including general-purpose disinfectants, chlorine-free bleaches, fabric stain removers, contact lens disinfectants and hair dyes, and it is a component of some tooth whitening products. In industry, the principal use of hydrogen peroxide is as a bleaching agent in the manufacture of paper and pulp. Hydrogen peroxide has been employed medicinally for wound irrigation and for the sterilisation of ophthalmic and endoscopic instruments. Hydrogen peroxide causes toxicity via three main mechanisms: corrosive damage, oxygen gas formation and lipid peroxidation. Concentrated hydrogen peroxide is caustic and exposure may result in local tissue damage. Ingestion of concentrated (>35%) hydrogen peroxide can also result in the generation of substantial volumes of oxygen. Where the amount of oxygen evolved exceeds its maximum solubility in blood, venous or arterial gas embolism may occur. The mechanism of CNS damage is thought to be arterial gas embolisation with subsequent brain infarction. Rapid generation of oxygen in closed body cavities can also cause mechanical distension and there is potential for the rupture of the hollow viscus secondary to oxygen liberation. In addition, intravascular foaming following absorption can seriously impede right ventricular output and produce complete loss of cardiac output. Hydrogen peroxide can also exert a direct cytotoxic effect via lipid peroxidation. Ingestion of hydrogen peroxide may cause irritation of the gastrointestinal tract with nausea, vomiting, haematemesis and foaming at the mouth; the foam may obstruct the respiratory tract or result in pulmonary aspiration. Painful gastric distension and belching may be caused by the liberation of large volumes of oxygen in the stomach. Blistering of the mucosae and oropharyngeal burns are common following ingestion of concentrated solutions, and laryngospasm and haemorrhagic gastritis have been

  18. Proline dehydrogenase is essential for proline protection against hydrogen peroxide induced cell death

    PubMed Central

    Natarajan, Sathish Kumar; Zhu, Weidong; Liang, Xinwen; Zhang, Lu; Demers, Andrew J.; Zimmerman, Matthew C.; Simpson, Melanie A.; Becker, Donald F.

    2012-01-01

    Proline metabolism has an underlying role in apoptotic signaling that impacts tumorigenesis. Proline is oxidized to glutamate in the mitochondria with the rate limiting step catalyzed by proline dehydrogenase (PRODH). PRODH expression is inducible by p53 leading to increased proline oxidation, reactive oxygen species (ROS) formation, and induction of apoptosis. Paradoxical to its role in apoptosis, proline also protects cells against oxidative stress. Here we explore the mechanism of proline protection against hydrogen peroxide stress in melanoma WM35 cells. Treatment of WM35 cells with proline significantly increased cell viability, diminished oxidative damage of cellular lipids and proteins, and retained ATP and NADPH levels after exposure to hydrogen peroxide. Inhibition or siRNA-mediated knockdown of PRODH abolished proline protection against oxidative stress whereas knockdown of Δ1-pyrroline-5-carboxylate reductase, a key enzyme in proline biosynthesis, had no impact on proline protection. Potential linkages between proline metabolism and signaling pathways were explored. The combined inhibition of the mammalian target of rapamycin complex 1 (mTORC1) and mTORC2 eliminated proline protection. A significant increase in Akt activation was observed in proline treated cells after hydrogen peroxide stress along with a corresponding increase in the phosphorylation of the fork head transcription factor class O3a (FoxO3a). The role of PRODH in proline mediated protection was validated in the prostate carcinoma cell line, PC3. Knockdown of PRODH in PC3 cells attenuated phosphorylated levels of Akt and FoxO3a and decreased cell survival during hydrogen peroxide stress. The results provide evidence that PRODH is essential in proline protection against hydrogen peroxide mediated cell death and that proline/PRODH helps activate Akt in cancer cells. PMID:22796327

  19. Radiation-induced degradation of an epoxy thermoset supported by hydrogen peroxide

    NASA Astrophysics Data System (ADS)

    Nowicki, Andrzej; Przybytniak, Grażyna; Legocka, Izabella; Mirkowski, Krzysztof

    2014-01-01

    Epoxy resin was decomposed applying two complementary treatments, namely (1) soaking up with 30% aqueous solution of hydrogen peroxide and (2) exposure of the swelled material to ionizing radiation in air atmosphere over doses up to 1000 kGy. The phase transition characteristic determined by the DSC technique revealed that both factors, swelling with oxidizing agent and irradiation applied sequentially induce in the resin deep structural changes resulting in the rise of two new exothermic transitions assigned to hydrogen peroxide decomposition and resin oxidation. The flexural stress at break measurements confirmed significant influence of H2O2 on the mechanical properties of the irradiated material which, under applied conditions, is efficiently decayed via oxidative degradation. On the basis of results obtained by EPR spectroscopy chemical mechanism of the radiation induced degradation was proposed.

  20. Pneumococcal hydrogen peroxide-induced stress signaling regulates inflammatory genes.

    PubMed

    Loose, Maria; Hudel, Martina; Zimmer, Klaus-Peter; Garcia, Ernesto; Hammerschmidt, Sven; Lucas, Rudolf; Chakraborty, Trinad; Pillich, Helena

    2015-01-15

    Microbial infections can induce aberrant responses in cellular stress pathways, leading to translational attenuation, metabolic restriction, and activation of oxidative stress, with detrimental effects on cell survival. Here we show that infection of human airway epithelial cells with Streptococcus pneumoniae leads to induction of endoplasmic reticulum (ER) and oxidative stress, activation of mitogen-associated protein kinase (MAPK) signaling pathways, and regulation of their respective target genes. We identify pneumococcal H2O2 as the causative agent for these responses, as both catalase-treated and pyruvate oxidase-deficient bacteria lacked these activities. Pneumococcal H2O2 induced nuclear NF-κB translocation and transcription of proinflammatory cytokines. Inhibition of translational arrest and ER stress by salubrinal or of MAPK signaling pathways attenuate cytokine transcription. These results provide strong evidence for the notion that inhibition of translation is an important host pathway in monitoring harmful pathogen-associated activities, thereby enabling differentiation between pathogenic and nonpathogenic bacteria. PMID:25183769

  1. Hydrogen peroxide is involved in collagen-induced platelet activation.

    PubMed

    Pignatelli, P; Pulcinelli, F M; Lenti, L; Gazzaniga, P P; Violi, F

    1998-01-15

    In this study, we investigated whether (1) collagen-induced platelet aggregation is associated with a burst of H2O2, (2) this oxidant species is involved in the activation of platelets, and (3) the pathways of platelet activation are stimulated by H2O2. Collagen-induced platelet aggregation was associated with production of H2O2, which was abolished by catalase, an enzyme that destroys H2O2. H2O2 production was not observed when ADP or thrombin were used as agonists. Catalase inhibited dose-dependently thromboxane A2 production, release of arachidonic acid from platelet membrane, and Inositol 1,4,5P3 (IP3) formation. In aspirin-treated platelets stimulated with high concentrations of collagen, catalase inhibited platelet aggregation, calcium mobilization, and IP3 production. This study suggests that collagen-induced platelet aggregation is associated with a burst of H2O2 that acts as a second messenger by stimulating the arachidonic acid metabolism and phospholipase C pathway.

  2. Hydrogen peroxide catalytic decomposition

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2010-01-01

    Nitric oxide in a gaseous stream is converted to nitrogen dioxide using oxidizing species generated through the use of concentrated hydrogen peroxide fed as a monopropellant into a catalyzed thruster assembly. The hydrogen peroxide is preferably stored at stable concentration levels, i.e., approximately 50%-70% by volume, and may be increased in concentration in a continuous process preceding decomposition in the thruster assembly. The exhaust of the thruster assembly, rich in hydroxyl and/or hydroperoxy radicals, may be fed into a stream containing oxidizable components, such as nitric oxide, to facilitate their oxidation.

  3. Electrochemical Hydrogen Peroxide Generator

    NASA Technical Reports Server (NTRS)

    Tennakoon, Charles L. K.; Singh, Waheguru; Anderson, Kelvin C.

    2010-01-01

    Two-electron reduction of oxygen to produce hydrogen peroxide is a much researched topic. Most of the work has been done in the production of hydrogen peroxide in basic media, in order to address the needs of the pulp and paper industry. However, peroxides under alkaline conditions show poor stabilities and are not useful in disinfection applications. There is a need to design electrocatalysts that are stable and provide good current and energy efficiencies to produce hydrogen peroxide under acidic conditions. The innovation focuses on the in situ generation of hydrogen peroxide using an electrochemical cell having a gas diffusion electrode as the cathode (electrode connected to the negative pole of the power supply) and a platinized titanium anode. The cathode and anode compartments are separated by a readily available cation-exchange membrane (Nafion 117). The anode compartment is fed with deionized water. Generation of oxygen is the anode reaction. Protons from the anode compartment are transferred across the cation-exchange membrane to the cathode compartment by electrostatic attraction towards the negatively charged electrode. The cathode compartment is fed with oxygen. Here, hydrogen peroxide is generated by the reduction of oxygen. Water may also be generated in the cathode. A small amount of water is also transported across the membrane along with hydrated protons transported across the membrane. Generally, each proton is hydrated with 3-5 molecules. The process is unique because hydrogen peroxide is formed as a high-purity aqueous solution. Since there are no hazardous chemicals or liquids used in the process, the disinfection product can be applied directly to water, before entering a water filtration unit to disinfect the incoming water and to prevent the build up of heterotrophic bacteria, for example, in carbon based filters. The competitive advantages of this process are: 1. No consumable chemicals are needed in the process. The only raw materials

  4. Hyperthermic pre-treatment protects rat IPC-81 leukaemia cells against heat- and hydrogen peroxide-induced apoptosis.

    PubMed

    Zeise, E; Rensing, L

    2002-01-01

    It is well known that hyperthermia causes a transient tolerance of cells to a second heat challenge (acquired thermotolerance). The present study addresses the question of whether hyperthermic pre-treatment also increases the tolerance against heat- and hydrogen peroxide-induced apoptosis in rat IPC-81 leukaemia cells. This cell line exhibits an aberrant heat shock response which is characterized by a lack of the inducible Hsp70 isoform, even under conditions of heat or hydrogen peroxide stress, while the constitutively expressed Hsc70 and the inducible isoform of hemoxygenase (HO-1) are strongly enhanced by heat stress (43.5 degrees C; 30 min). In spite of this Hsp70 deficiency, hyperthermic pre-treatment protects IPC-81 leukaemia cells against apoptotic cell death induced by heat or hydrogen peroxide, but is less effective against necrosis induced by higher doses of the applied stressors. Addition of hydrogen peroxide (25 microM) enhances the amount of bax mRNA, while the level of bcl-2 mRNA remains unchanged. No increase of bax mRNA, in contrast, could be detected in heat shock-primed IPC-81 cells when treated with hydrogen peroxide after a 12h recovery. These results indicate that hyperthermic pre-treatment may exert its anti-apoptotic function not only by enhanced expression of constitutive as well as inducible HSPs but also by lowering the level of bax transcripts and thereby increasing the Bcl-2/Bax ratio.

  5. Layer-by-layer immobilized catalase on electrospun nanofibrous mats protects against oxidative stress induced by hydrogen peroxide.

    PubMed

    Huang, Rong; Deng, Hongbing; Cai, Tongjian; Zhan, Yingfei; Wang, Xiankai; Chen, Xuanxuan; Ji, Ailing; Lil, Xueyong

    2014-07-01

    Catalase, a kind of redox enzyme and generally recognized as an efficient agent for protecting cells against hydrogen peroxide (H2O2)-induced cytotoxicity. The immobilization of catalase was accomplished by depositing the positively charged chitosan and the negatively charged catalase on electrospun cellulose nanofibrous mats through electrospining and layer-by-layer (LBL) techniques. The morphology obtained from Field emission scanning electron microscopy (FE-SEM) indicated that more orderly arranged three-dimension (3D) structure and roughness formed with increasing the number of coating bilayers. Besides, the enzyme-immobilized nanofibrous mats were found with high enzyme loading and activity, moreover, X-ray photoelectron spectroscopy (XPS) results further demonstrated the successful immobilization of chitosan and catalase on cellulose nanofibers support. Furthermore, we evaluated the cytotoxicity induced by hydrogen peroxide in the Human umbilical vascular endothelial cells with or without pretreatment of nanofibrous mats by MTT assay, LDH activity and Flow cytometric evaluation, and confirmed the pronounced hydrogen peroxide-induced toxicity, but pretreatment of immobilized catalase reduced the cytotoxicity and protected cells against hydrogen peroxide-induced cytotoxic effects which were further demonstrated by scanning electron microscopy (SEM) and Transmission Electron Microscopy (TEM) images. The data pointed toward a role of catalase-immobilized nanofibrous mats in protecting cells against hydrogen peroxide-induced cellular damage and their potential application in biomedical field.

  6. Resveratrol attenuated hydrogen peroxide-induced myocardial apoptosis by autophagic flux

    PubMed Central

    Huang, Chih-Yang; Ting, Wei-Jen; Huang, Chih-Yang; Yang, Jing-Yi; Lin, Wan-Teng

    2016-01-01

    Background Resveratrol is a Sirt-1-specific activator, which also exerts cardioprotective effects that regulate redox signalling during oxidative stress and autophagy during cardiovascular disease (CVD). Objective This study investigated the protective effects of resveratrol against hydrogen peroxide-induced damage in cardiomyocytes. Design In this article, hydrogen peroxide-induced autophagy and apoptosis in H9c2 cardiomyoblasts were studied at an increasing concentration from 0 to 100 µM. Results Resveratrol pretreatment with concentrations of 10, 20, and 50 µM inhibits autophagic apoptosis by increasing p-Akt and Bcl-2 protein levels in H9c2 cells. Interestingly, resveratrol treatment activates the Beclin-1, LC3, p62, and the lysosome-associated protein LAMP2a within 24 h of administration. Conclusions These results suggest that resveratrol-regulated autophagy may play a role in degrading damaged organelles in H9c2 cells rather than causing apoptosis, and this may be a possible mechanism by which resveratrol protects the heart during CVD. PMID:27211317

  7. A comprehensive analysis of hydrogen peroxide-induced gene expression in tobacco

    PubMed Central

    Vandenabeele, Steven; Van Der Kelen, Katrien; Dat, James; Gadjev, Ilya; Boonefaes, Tom; Morsa, Stijn; Rottiers, Pieter; Slooten, Luit; Van Montagu, Marc; Zabeau, Marc; Inzé, Dirk; Van Breusegem, Frank

    2003-01-01

    Hydrogen peroxide plays a central role in launching the defense response during stress in plants. To establish a molecular profile provoked by a sustained increase in hydrogen peroxide levels, catalase-deficient tobacco plants (CAT1AS) were exposed to high light (HL) intensities over a detailed time course. The expression kinetics of >14,000 genes were monitored by using transcript profiling technology based on cDNA-amplified fragment length polymorphism. Clustering and sequence analysis of 713 differentially expressed transcript fragments revealed a transcriptional response that mimicked that reported during both biotic and abiotic stresses, including the up-regulation of genes involved in the hypersensitive response, vesicular transport, posttranscriptional processes, biosynthesis of ethylene and jasmonic acid, proteolysis, mitochondrial metabolism, and cell death, and was accompanied by a very rapid up-regulation of several signal transduction components. Expression profiling corroborated by functional experiments showed that HL induced photoinhibition in CAT1AS plants and that a short-term HL exposure of CAT1AS plants triggered an increased tolerance against a subsequent severe oxidative stress. PMID:14671332

  8. Hydrogen peroxide derived from marine peroxy sesquiterpenoids induces apoptosis in HCT116 human colon cancer cells.

    PubMed

    Miyazato, Haruna; Taira, Junsei; Ueda, Katsuhiro

    2016-10-01

    In this study, the isolates of the peroxy sesquiterpenoids (1-3) from the Okinawan soft coral, Sinularia sp., indicated cytotoxicity in HCT116 colon cancer cells. The apoptotic cells with a nuclear condensation were detected in the presence of these compounds, then the caspase 3/7 activity was induced, indicating that the compounds have a potential antitumor activity by apoptosis-induction. The cells treated with these compounds were generated reactive oxygen species (ROS), indicating that the ROS is related to the induction of apoptosis. The ROS production reduced in the presence of catalase or trolox, indicating that hydrogen peroxide (H2O2) is generated through a certain free radical reaction derived from the compound. In fact, the accumulation of intracellular H2O2 was also confirmed in the presence of these compounds. Based on all the results, this study proposed the apoptosis-inducing mechanism due to the compounds that the H2O2 produced involving free radical reactions derived from cleavage of the end or hydro-peroxide in the molecule induced cell death.

  9. Hydrogen peroxide derived from marine peroxy sesquiterpenoids induces apoptosis in HCT116 human colon cancer cells.

    PubMed

    Miyazato, Haruna; Taira, Junsei; Ueda, Katsuhiro

    2016-10-01

    In this study, the isolates of the peroxy sesquiterpenoids (1-3) from the Okinawan soft coral, Sinularia sp., indicated cytotoxicity in HCT116 colon cancer cells. The apoptotic cells with a nuclear condensation were detected in the presence of these compounds, then the caspase 3/7 activity was induced, indicating that the compounds have a potential antitumor activity by apoptosis-induction. The cells treated with these compounds were generated reactive oxygen species (ROS), indicating that the ROS is related to the induction of apoptosis. The ROS production reduced in the presence of catalase or trolox, indicating that hydrogen peroxide (H2O2) is generated through a certain free radical reaction derived from the compound. In fact, the accumulation of intracellular H2O2 was also confirmed in the presence of these compounds. Based on all the results, this study proposed the apoptosis-inducing mechanism due to the compounds that the H2O2 produced involving free radical reactions derived from cleavage of the end or hydro-peroxide in the molecule induced cell death. PMID:27575468

  10. Lipid Peroxide-Derived Short-Chain Carbonyls Mediate Hydrogen Peroxide-Induced and Salt-Induced Programmed Cell Death in Plants1[OPEN

    PubMed Central

    Biswas, Md. Sanaullah; Mano, Jun’ichi

    2015-01-01

    Lipid peroxide-derived toxic carbonyl compounds (oxylipin carbonyls), produced downstream of reactive oxygen species (ROS), were recently revealed to mediate abiotic stress-induced damage of plants. Here, we investigated how oxylipin carbonyls cause cell death. When tobacco (Nicotiana tabacum) Bright Yellow-2 (BY-2) cells were exposed to hydrogen peroxide, several species of short-chain oxylipin carbonyls [i.e. 4-hydroxy-(E)-2-nonenal and acrolein] accumulated and the cells underwent programmed cell death (PCD), as judged based on DNA fragmentation, an increase in terminal deoxynucleotidyl transferase dUTP nick end labeling-positive nuclei, and cytoplasm retraction. These oxylipin carbonyls caused PCD in BY-2 cells and roots of tobacco and Arabidopsis (Arabidopsis thaliana). To test the possibility that oxylipin carbonyls mediate an oxidative signal to cause PCD, we performed pharmacological and genetic experiments. Carnosine and hydralazine, having distinct chemistry for scavenging carbonyls, significantly suppressed the increase in oxylipin carbonyls and blocked PCD in BY-2 cells and Arabidopsis roots, but they did not affect the levels of ROS and lipid peroxides. A transgenic tobacco line that overproduces 2-alkenal reductase, an Arabidopsis enzyme to detoxify α,β-unsaturated carbonyls, suffered less PCD in root epidermis after hydrogen peroxide or salt treatment than did the wild type, whereas the ROS level increases due to the stress treatments were not different between the lines. From these results, we conclude that oxylipin carbonyls are involved in the PCD process in oxidatively stressed cells. Our comparison of the ability of distinct carbonyls to induce PCD in BY-2 cells revealed that acrolein and 4-hydroxy-(E)-2-nonenal are the most potent carbonyls. The physiological relevance and possible mechanisms of the carbonyl-induced PCD are discussed. PMID:26025050

  11. Lipid Peroxide-Derived Short-Chain Carbonyls Mediate Hydrogen Peroxide-Induced and Salt-Induced Programmed Cell Death in Plants.

    PubMed

    Biswas, Md Sanaullah; Mano, Jun'ichi

    2015-07-01

    Lipid peroxide-derived toxic carbonyl compounds (oxylipin carbonyls), produced downstream of reactive oxygen species (ROS), were recently revealed to mediate abiotic stress-induced damage of plants. Here, we investigated how oxylipin carbonyls cause cell death. When tobacco (Nicotiana tabacum) Bright Yellow-2 (BY-2) cells were exposed to hydrogen peroxide, several species of short-chain oxylipin carbonyls [i.e. 4-hydroxy-(E)-2-nonenal and acrolein] accumulated and the cells underwent programmed cell death (PCD), as judged based on DNA fragmentation, an increase in terminal deoxynucleotidyl transferase dUTP nick end labeling-positive nuclei, and cytoplasm retraction. These oxylipin carbonyls caused PCD in BY-2 cells and roots of tobacco and Arabidopsis (Arabidopsis thaliana). To test the possibility that oxylipin carbonyls mediate an oxidative signal to cause PCD, we performed pharmacological and genetic experiments. Carnosine and hydralazine, having distinct chemistry for scavenging carbonyls, significantly suppressed the increase in oxylipin carbonyls and blocked PCD in BY-2 cells and Arabidopsis roots, but they did not affect the levels of ROS and lipid peroxides. A transgenic tobacco line that overproduces 2-alkenal reductase, an Arabidopsis enzyme to detoxify α,β-unsaturated carbonyls, suffered less PCD in root epidermis after hydrogen peroxide or salt treatment than did the wild type, whereas the ROS level increases due to the stress treatments were not different between the lines. From these results, we conclude that oxylipin carbonyls are involved in the PCD process in oxidatively stressed cells. Our comparison of the ability of distinct carbonyls to induce PCD in BY-2 cells revealed that acrolein and 4-hydroxy-(E)-2-nonenal are the most potent carbonyls. The physiological relevance and possible mechanisms of the carbonyl-induced PCD are discussed.

  12. L-carnitine improves hydrogen peroxide-induced impairment of nuclear maturation in porcine oocytes.

    PubMed

    Yazaki, Takako; Hiradate, Yuki; Hoshino, Yumi; Tanemura, Kentaro; Sato, Eimei

    2013-05-01

    We investigated the effect of oxidative stress induced by hydrogen peroxide (H2 O2 ) on lipid peroxide (LPO) level and nuclear maturation in porcine oocytes cultured with or without cumulus cells. After 22 h of pre-culture, oocytes with attached cumulus cells (COC group) or denuded oocytes (DO group) were cultured with H2 O2 , and intra-oocyte H2 O2 and LPO levels were quantitatively analyzed using immunofluorescence. This is the first report evaluating LPO levels in porcine oocytes. After H2 O2 supplementation, the DO group showed severe accumulation of H2 O2 and LPO in the oocytes. Similarly, while inhibition of progression of nuclear maturation was observed in both groups, the effect was more severe in the DO group. These results demonstrate that cumulus cells reduce the accumulation of H2 O2 stress in oocytes. Furthermore, we attempted to reduce the oxidative stress by H2 O2 with L-carnitine, a H2 O2 scavenger. L-carnitine decreased H2 O2 and LPO levels in the oocytes in both groups, and improvement in the progression of impaired nuclear maturation was observed. These effects were different by the presence of cumulus cells. Our results provide that L-carnitine is useful for alleviating H2 O2 -induced oxidative stress by reducing LPO levels and improving the progression of nuclear maturation. PMID:23607575

  13. Aqueous 4-nitrophenol decomposition and hydrogen peroxide formation induced by contact glow discharge electrolysis.

    PubMed

    Liu, Yongjun; Wang, Degao; Sun, Bing; Zhu, Xiaomei

    2010-09-15

    Liquid-phase decomposition of 4-nitrophenol (4-NP) and formation of hydrogen peroxide (H(2)O(2)) induced by contact glow discharge electrolysis (CGDE) were investigated. Experimental results showed that the decays of 4-NP and total organic carbon (TOC) obeyed the first-order and pseudo-first-order reaction kinetics, respectively. The major intermediate products were 4-nitrocatechol, hydroquinone, benzoquinone, hydroxyhydroquinone, organic acids and nitrite ion. The final products were carbon dioxide and nitrate ion. The initial formation rate of H(2)O(2) decreased linearly with increasing initial concentration of 4-NP. Addition of iron ions, especially ferric ion, to the solution significantly enhanced the 4-NP removal due to the additional hydroxyl radical formation through Fenton's reaction. A reaction pathway is proposed based on the degradation kinetics and the distribution of intermediate products.

  14. Aqueous 4-nitrophenol decomposition and hydrogen peroxide formation induced by contact glow discharge electrolysis.

    PubMed

    Liu, Yongjun; Wang, Degao; Sun, Bing; Zhu, Xiaomei

    2010-09-15

    Liquid-phase decomposition of 4-nitrophenol (4-NP) and formation of hydrogen peroxide (H(2)O(2)) induced by contact glow discharge electrolysis (CGDE) were investigated. Experimental results showed that the decays of 4-NP and total organic carbon (TOC) obeyed the first-order and pseudo-first-order reaction kinetics, respectively. The major intermediate products were 4-nitrocatechol, hydroquinone, benzoquinone, hydroxyhydroquinone, organic acids and nitrite ion. The final products were carbon dioxide and nitrate ion. The initial formation rate of H(2)O(2) decreased linearly with increasing initial concentration of 4-NP. Addition of iron ions, especially ferric ion, to the solution significantly enhanced the 4-NP removal due to the additional hydroxyl radical formation through Fenton's reaction. A reaction pathway is proposed based on the degradation kinetics and the distribution of intermediate products. PMID:20576351

  15. Chloride channels involve in hydrogen peroxide-induced apoptosis of PC12 cells.

    PubMed

    Zuo, Wanhong; Zhu, Linyan; Bai, Zhiquan; Zhang, Haifeng; Mao, Jianwen; Chen, Lixin; Wang, Liwei

    2009-10-01

    Chloride channel activity is one of the critical factors responsible for cell apoptotic volume decrease (AVD). However, the roles of chloride channels in apoptosis have not been fully understood. In the current study, we assessed the role of chloride channels in hydrogen peroxide (H(2)O(2))-induced apoptosis of pheochromocytoma cells (PC12). Extracellular application of H(2)O(2) activated a chloride current and induced cell volume decrease in a few minutes. Incubation of cells with H(2)O(2) elevated significantly the membrane permeability to the DNA dye Hoechst 33258 in 1h and induced apoptosis of most PC12 cells tested in 24h. The chloride channel blocker NPPB (5-nitro-2-(3-phenylpropylamino)-benzoate) prevented appearance of H(2)O(2)-induced high membrane permeability and cell shrinkage, suppressed H(2)O(2)-activated chloride currents and protected PC12 cells from apoptosis induced by H(2)O(2). The results suggest that chloride channels may contribute to H(2)O(2)-induced apoptosis by ways of elevation of membrane permeability and AVD in PC12 cells.

  16. Glutamine Deprivation Causes Hydrogen Peroxide-induced Interleukin-8 Expression via Jak1/Stat3 Activation in Gastric Epithelial AGS Cells

    PubMed Central

    Lee, Yun Mi; Kim, Mi Jung; Kim, Youngha; Kim, Hyeyoung

    2015-01-01

    Background: The Janus kinase (Jak)/Signal transducers of activated transcription (Stat) pathway is an upstream signaling pathway for NF-κB activation in Helicobacter pylori-induced interleukin (IL)-8 production in gastric epithelial AGS cells. H. pylori activates NADPH oxidase and produces hydrogen peroxide, which activates Jak1/Stat3 in AGS cells. Therefore, hydrogen peroxide may be critical for IL-8 production via Jak/Stat activation in gastric epithelial cells. Glutamine is depleted during severe injury and stress and contributes to the formation of glutathione (GSH), which is involved in conversion of hydrogen peroxide into water as a cofactor for GSH peroxidase. Methods: We investigated whether glutamine deprivation induces hydrogen peroxide-mediated IL-8 production and whether hydrogen peroxide activates Jak1/Stat3 to induce IL-8 in AGS cells. Cells were cultured in the presence or absence of glutamine or hydrogen peroxide, with or without GSH or a the Jak/Stat specific inhibitor AG490. Results: Glutamine deprivation decreased GSH levels, but increased levels of hydrogen peroxide and IL-8, an effect that was inhibited by treatment with GSH. Hydrogen peroxide induced the activation of Jak1/Stat3 time-dependently. AG490 suppressed hydrogen peroxide- induced activation of Jak1/Stat3 and IL-8 expression in AGS cells, but did not affect levels of reactive oxygen species in AGS cells. Conclusions: In gastric epithelial AGS cells, glutamine deprivation increases hydrogen peroxide levels and IL-8 expression, which may be mediated by Jak1/Stat3 activation. Glutamine supplementation may be beneficial for preventing gastric inflammation by suppressing hydrogen peroxide-mediated Jak1/Stat3 activation and therefore, reducing IL-8 production. Scavenging hydrogen peroxide or targeting Jak1/Stat3 may also prevent oxidant-mediated gastric inflammation. PMID:26473156

  17. Guard cell hydrogen peroxide and nitric oxide mediate elevated CO2 -induced stomatal movement in tomato.

    PubMed

    Shi, Kai; Li, Xin; Zhang, Huan; Zhang, Guanqun; Liu, Yaru; Zhou, Yanhong; Xia, Xiaojian; Chen, Zhixiang; Yu, Jingquan

    2015-10-01

    Climate change as a consequence of increasing atmospheric CO2 influences plant photosynthesis and transpiration. Although the involvement of stomata in plant responses to elevated CO2 has been well established, the underlying mechanism of elevated CO2 -induced stomatal movement remains largely unknown. We used diverse techniques, including laser scanning confocal microscopy, transmission electron microscopy, biochemical methodologies and gene silencing to investigate the signaling pathway for elevated CO2 -induced stomatal movement in tomato (Solanum lycopersicum). Elevated CO2 -induced stomatal closure was dependent on the production of RESPIRATORY BURST OXIDASE 1 (RBOH1)-mediated hydrogen peroxide (H2 O2 ) and NITRATE REDUCTASE (NR)-mediated nitric oxide (NO) in guard cells in an abscisic acid (ABA)-independent manner. Silencing of OPEN STOMATA 1 (OST1) compromised the elevated CO2 -induced accumulation of H2 O2 and NO, upregulation of SLOW ANION CHANNEL ASSOCIATED 1 (SLAC1) gene expression and reduction of stomatal aperture, whereas silencing of RBOH1 or NR had no effects on the expression of OST1. Our results demonstrate that as critical signaling molecules, RBOH1-dependent H2 O2 and NR-dependent NO act downstream of OST1 that regulate SLAC1 expression and elevated CO2 -induced stomatal movement. This information is crucial to deepen the understanding of CO2 signaling pathway in guard cells. PMID:26308648

  18. Protective effect of butylated hydroxylanisole against hydrogen peroxide-induced apoptosis in primary cultured mouse hepatocytes

    PubMed Central

    Hwang, Geun Hye; Jeon, Yu Jin; Han, Ho Jae; Park, Soo Hyun; Baek, Kyoung Min; Chang, Woochul; Kim, Joong Sun; Kim, Lark Kyun; Lee, You-Mie; Lee, Sangkyu; Bae, Jong-Sup; Jee, Jun-Goo

    2015-01-01

    Butylated hydroxyanisole (BHA) is a synthetic phenolic compound consisting of a mixture of two isomeric organic compounds: 2-tert-butyl-4-hydroxyanisole and 3-tert-butyl-4-hydroxyanisole. We examined the effect of BHA against hydrogen peroxide (H2O2)-induced apoptosis in primary cultured mouse hepatocytes. Cell viability was significantly decreased by H2O2 in a dose-dependent manner. Additionally, H2O2 treatment increased Bax, decreased Bcl-2, and promoted PARP-1 cleavage in a dose-dependent manner. Pretreatment with BHA before exposure to H2O2 significantly attenuated the H2O2-induced decrease of cell viability. H2O2 exposure resulted in an increase of intracellular reactive oxygen species (ROS) generation that was significantly inhibited by pretreatment with BHA or N-acetyl-cysteine (NAC, an ROS scavenger). H2O2-induced decrease of cell viability was also attenuated by pretreatment with BHA and NAC. Furthermore, H2O2-induced increase of Bax, decrease of Bcl-2, and PARP-1 cleavage was also inhibited by BHA. Taken together, results of this investigation demonstrated that BHA protects primary cultured mouse hepatocytes against H2O2-induced apoptosis by inhibiting ROS generation. PMID:25798044

  19. Guard cell hydrogen peroxide and nitric oxide mediate elevated CO2 -induced stomatal movement in tomato.

    PubMed

    Shi, Kai; Li, Xin; Zhang, Huan; Zhang, Guanqun; Liu, Yaru; Zhou, Yanhong; Xia, Xiaojian; Chen, Zhixiang; Yu, Jingquan

    2015-10-01

    Climate change as a consequence of increasing atmospheric CO2 influences plant photosynthesis and transpiration. Although the involvement of stomata in plant responses to elevated CO2 has been well established, the underlying mechanism of elevated CO2 -induced stomatal movement remains largely unknown. We used diverse techniques, including laser scanning confocal microscopy, transmission electron microscopy, biochemical methodologies and gene silencing to investigate the signaling pathway for elevated CO2 -induced stomatal movement in tomato (Solanum lycopersicum). Elevated CO2 -induced stomatal closure was dependent on the production of RESPIRATORY BURST OXIDASE 1 (RBOH1)-mediated hydrogen peroxide (H2 O2 ) and NITRATE REDUCTASE (NR)-mediated nitric oxide (NO) in guard cells in an abscisic acid (ABA)-independent manner. Silencing of OPEN STOMATA 1 (OST1) compromised the elevated CO2 -induced accumulation of H2 O2 and NO, upregulation of SLOW ANION CHANNEL ASSOCIATED 1 (SLAC1) gene expression and reduction of stomatal aperture, whereas silencing of RBOH1 or NR had no effects on the expression of OST1. Our results demonstrate that as critical signaling molecules, RBOH1-dependent H2 O2 and NR-dependent NO act downstream of OST1 that regulate SLAC1 expression and elevated CO2 -induced stomatal movement. This information is crucial to deepen the understanding of CO2 signaling pathway in guard cells.

  20. Ethylene-induced stomatal closure in Arabidopsis occurs via AtrbohF-mediated hydrogen peroxide synthesis.

    PubMed

    Desikan, Radhika; Last, Kathryn; Harrett-Williams, Rhian; Tagliavia, Cecilia; Harter, Klaus; Hooley, Richard; Hancock, John T; Neill, Steven J

    2006-09-01

    Ethylene is a plant hormone that regulates many aspects of growth and development. Despite the well-known association between ethylene and stress signalling, its effects on stomatal movements are largely unexplored. Here, genetic and physiological data are provided that position ethylene into the Arabidopsis guard cell signalling network, and demonstrate a functional link between ethylene and hydrogen peroxide (H(2)O(2)). In wild-type leaves, ethylene induces stomatal closure that is dependent on H(2)O(2) production in guard cells, generated by the nicotinamide adenine dinucleotide phosphate hydrogen (NADPH) oxidase AtrbohF. Ethylene-induced closure is inhibited by the ethylene antagonists 1-MCP and silver. The ethylene receptor mutants etr1-1 and etr1-3 are insensitive to ethylene in terms of stomatal closure and H(2)O(2) production. Stomata of the ethylene signalling ein2-1 and arr2 mutants do not close in response to either ethylene or H(2)O(2) but do generate H(2)O(2) following ethylene challenge. Thus, the data indicate that ethylene and H(2)O(2) signalling in guard cells are mediated by ETR1 via EIN2 and ARR2-dependent pathway(s), and identify AtrbohF as a key mediator of stomatal responses to ethylene.

  1. Protection of Bovine Mammary Epithelial Cells from Hydrogen Peroxide-Induced Oxidative Cell Damage by Resveratrol

    PubMed Central

    Jin, Xiaolu; Wang, Kai; Liu, Hongyun; Hu, Fuliang; Zhao, Fengqi; Liu, Jianxin

    2016-01-01

    The mammary epithelial cells (MECs) of high-producing dairy cows are likely to be subject to oxidative stress (OS) due to the intensive cell metabolism. The objectives of this study were to investigate the cytoprotective effects of resveratrol against hydrogen peroxide- (H2O2-) induced OS in cultured bovine MECs (MAC-T). Pretreatment of MAC-T cells with resveratrol could rescue the decrease in cell viability and resulted in lower intracellular reactive oxygen species (ROS) accumulation after H2O2 exposure. Resveratrol helped MAC-T cells to prevent H2O2-induced endoplasmic reticulum stress and mitochondria-related cell apoptosis. Moreover, resveratrol induced mRNA expression of multiple antioxidant defense genes in MAC-T cells under normal/oxidative conditions. Nuclear factor erythroid 2-related factor 2 (Nrf2) was required for the cytoprotective effects on MAC-T cells by resveratrol, as knockdown of Nrf2 significantly abolished resveratrol-induced cytoprotective effects against OS. In addition, by using selective inhibitors, we further confirmed that the induction of Nrf2 by resveratrol was mediated through the prolonged activation of PI3K/Akt and ERK/MAPK pathways but negatively regulated by p38/MAPK pathway. Overall, resveratrol has beneficial effects on bovine MECs redox balance and may be potentially used as a therapeutic medicine against oxidative insult in lactating animals. PMID:26962394

  2. TNF-alpha and IL-1alpha induce apoptosis in subconfluent rat mesangial cells. Evidence for the involvement of hydrogen peroxide and lipid peroxidation as second messengers.

    PubMed

    Böhler, T; Waiser, J; Hepburn, H; Gaedeke, J; Lehmann, C; Hambach, P; Budde, K; Neumayer, H H

    2000-07-01

    Apoptosis of mesangial cells (MC) plays a role in glomerulonephritis (GN). In this study we investigated cytokine-induced apoptosis of cultured rat MC by morphological and biochemical features. TNF-alpha and IL-1alpha induced apoptosis in rat MC in a time- and concentration-dependent fashion. RT-PCR experiments revealed that MC express the TNF-receptor 1 (p60) gene constitutively. TNF-alpha as well as IL-1alpha stimulated the production of reactive oxygen species (ROS) and induced lipid peroxidation. Coincubation with catalase inhibited TNF-alpha and IL-1alpha induced apoptosis as well as lipid peroxidation. TNF-alpha, but not IL-1alpha increased the expression of c-jun. These results provide evidence that TNF-alpha and IL-1alpha induce apoptosis in rat MC with hydrogen peroxide and lipid peroxidation as second messengers. Increased c-jun expression may be a downstream intracellular signal of TNF-alpha-, but not IL-1alpha-induced apoptosis.

  3. 21 CFR 184.1366 - Hydrogen peroxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Hydrogen peroxide. 184.1366 Section 184.1366 Food... Specific Substances Affirmed as GRAS § 184.1366 Hydrogen peroxide. (a) Hydrogen peroxide (H2O2, CAS Reg. No... distillation of the hydrogen peroxide formed; by decomposition of barium peroxide with sulfuric or...

  4. 21 CFR 184.1366 - Hydrogen peroxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Hydrogen peroxide. 184.1366 Section 184.1366 Food... Specific Substances Affirmed as GRAS § 184.1366 Hydrogen peroxide. (a) Hydrogen peroxide (H2O2, CAS Reg. No... distillation of the hydrogen peroxide formed; by decomposition of barium peroxide with sulfuric or...

  5. 21 CFR 184.1366 - Hydrogen peroxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Hydrogen peroxide. 184.1366 Section 184.1366 Food... Specific Substances Affirmed as GRAS § 184.1366 Hydrogen peroxide. (a) Hydrogen peroxide (H2O2, CAS Reg. No... distillation of the hydrogen peroxide formed; by decomposition of barium peroxide with sulfuric or...

  6. 21 CFR 184.1366 - Hydrogen peroxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Hydrogen peroxide. 184.1366 Section 184.1366 Food... Specific Substances Affirmed as GRAS § 184.1366 Hydrogen peroxide. (a) Hydrogen peroxide (H2O2, CAS Reg. No... distillation of the hydrogen peroxide formed; by decomposition of barium peroxide with sulfuric or...

  7. Protective effects of parecoxib on rat primary astrocytes from oxidative stress induced by hydrogen peroxide* #

    PubMed Central

    Ling, Yun-zhi; Li, Xiao-hong; Yu, Li; Zhang, Ye; Liang, Qi-sheng; Yang, Xiao-di; Wang, Hong-tao

    2016-01-01

    Objective: To investigate the protective effects of parecoxib from oxidative stress induced by hydrogen peroxide (H2O2) in rat astrocytes in vitro. Methods: All experiments included 4 groups: (1) negative control (NC) group, without any treatment; (2) H2O2 treatment group, 100 μmol/L H2O2 treatment for 24 h; (3) and (4) parecoxib pretreatment groups, 80 and 160 μmol/L parecoxib treatment for 24 h, respectively, and then treated with 100 μmol/L H2O2. Several indices were investigated, and the expressions of Bax, Bcl-2, and brain-derived neurotrophic factor (BDNF) were quantified. Results: Compared to the NC group, exposure to H2O2 resulted in significant morphological changes, which could be reversed by pretreatment of parecoxib. In addition, H2O2 treatment led to loss of viability (P=0.026) and increased intracellular reactive oxygen species (ROS) levels (P<0.001), and induced apoptosis (P<0.01) in the primary astrocytes relative to the NC group. However, in the parecoxib pretreatment groups, all the above changes reversed significantly (P<0.05) as compared to the H2O2 treatment group, and were nearly unchanged when compared to the NC group. Mechanical investigation showed that dysregulated Bax, Bcl-2, and BDNF could be implicated in these changes. Conclusions: Our results indicated that parecoxib provided a protective effect from oxidative stress induced by exposure to H2O2. PMID:27604861

  8. Ganglioside GT1b protects human spermatozoa from hydrogen peroxide-induced DNA and membrane damage.

    PubMed

    Gavella, Mirjana; Garaj-Vrhovac, Verica; Lipovac, Vaskresenija; Antica, Mariastefania; Gajski, Goran; Car, Nikica

    2010-06-01

    We have reported previously that various gangliosides, the sialic acid containing glycosphingolipids, provide protection against sperm injury caused by reactive oxygen species (ROS). In this study, we investigated the effect of treatment of human spermatozoa with ganglioside GT1b on hydrogen peroxide (H(2)O(2))-induced DNA fragmentation and plasma membrane damage. Single-cell gel electrophoresis (Comet assay) used in the assessment of sperm DNA integrity showed that in vitro supplemented GT1b (100 microm) significantly reduced DNA damage induced by H(2)O(2) (200 microm) (p < 0.05). Measurements of Annexin V binding in combination with the propidium iodide vital dye labelling demonstrated that the spermatozoa pre-treated with GT1b exhibited a significant increase (p < 0.05) in the percentage of live cells with intact membrane and decreased phosphatidylserine translocation after exposure to H(2)O(2). Flow cytometry using the intracellular ROS-sensitive fluorescence dichlorodihydrofluorescein diacetate dye employed to investigate the transport of the extracellularly supplied H(2)O(2) into the cell interior revealed that ganglioside GT1b completely inhibited the passage of H(2)O(2) through the sperm membrane. These results suggest that ganglioside GT1b may protect human spermatozoa from H(2)O(2)-induced damage by rendering sperm membrane more hydrophobic, thus inhibiting the diffusion of H(2)O(2) across the membrane.

  9. Negative Regulation of NADPH Oxidase 4 by Hydrogen Peroxide-inducible Clone 5 (Hic-5) Protein*

    PubMed Central

    Desai, Leena P.; Zhou, Yong; Estrada, Aida V.; Ding, Qiang; Cheng, Guangjie; Collawn, James F.; Thannickal, Victor J.

    2014-01-01

    Hydrogen peroxide-inducible clone 5 (Hic-5) is a focal adhesion adaptor protein induced by the profibrotic cytokine TGF-β1. We have demonstrated previously that TGF-β1 induces myofibroblast differentiation and lung fibrosis by activation of the reactive oxygen species-generating enzyme NADPH oxidase 4 (Nox4). Here we investigated a potential role for Hic-5 in regulating Nox4, myofibroblast differentiation, and senescence. In normal human diploid fibroblasts, TGF-β1 induces Hic-5 expression in a delayed manner relative to the induction of Nox4 and myofibroblast differentiation. Hic-5 silencing induced constitutive Nox4 expression and enhanced TGF-β1-inducible Nox4 levels. The induction of constitutive Nox4 protein in Hic-5-silenced cells was independent of transcription and translation and controlled by the ubiquitin-proteasomal system. Hic-5 associates with the ubiquitin ligase Cbl-c and the ubiquitin-binding protein heat shock protein 27 (HSP27). The interaction of these proteins is required for the ubiquitination of Nox4 and for maintaining low basal levels of this reactive oxygen species-generating enzyme. Our model suggests that TGF-β1-induced Hic-5 functions as a negative feedback mechanism to limit myofibroblast differentiation and senescence by promoting the ubiquitin-proteasomal system-mediated degradation of Nox4. Together, these studies indicate that endogenous Hic-5 suppresses senescence and profibrotic activities of myofibroblasts by down-regulating Nox4 protein expression. Additionally, these are the first studies, to our knowledge, to demonstrate posttranslational regulation of Nox4. PMID:24831009

  10. Mechanical wounding-induced laticifer differentiation in rubber tree: An indicative role of dehydration, hydrogen peroxide, and jasmonates.

    PubMed

    Tian, Wei-Min; Yang, Shu-Guang; Shi, Min-Jing; Zhang, Shi-Xin; Wu, Ji-Lin

    2015-06-15

    The secondary laticifer in the secondary phloem of rubber tree are a specific tissue differentiating from vascular cambia. The number of the secondary laticifers is closely related to the rubber productivity of Hevea. Factors involved in the mechanical wounding-induced laticifer differentiation were analyzed by using paraffin section, gas chromatography-mass spectrometry (GC-MS), and Northern-blot techniques. Dehydration of the wounded bark tissues triggered a burst of hydrogen peroxide, abscisic acid, and jasmonates and up-regulated the expression of HbAOSa, which was associated with the secondary laticifer differentiation strictly limited to the wounded area. Application of exogenous hydrogen peroxide, methyl jasmonate, and polyethylene glycol 6000 (PEG6000) could induce the secondary laticifer differentiation, respectively. Moreover, 6-Benzylaminopurine, a synthetic cytokinin, enhanced the methyl jasmonate-induced secondary laticifer differentiation. However, the dehydration-induced secondary laticifer differentiation was inhibited by exogenous abscisic acid. Diphenyleneiodonium chloride (DPI), a specific inhibitor of NADPH oxidase, was effective in inhibiting the accumulation of hydrogen peroxide as well as of jasmonates upon dehydration. It blocked the dehydration-induced but not the methyl jasmonate-induced secondary laticifer differentiation. The results suggested a stress signal pathway mediating the wound-induced secondary laticifer differentiation in rubber tree.

  11. Is Hydrogen Peroxide a Suitable Apoptosis Inducer for All Cell Types?

    PubMed Central

    Xiang, Jinmei; Wan, Chunyun; Guo, Rui

    2016-01-01

    Hydrogen peroxide is currently the most widely used apoptosis inducer due to its broad cytotoxic efficacy against nearly all cell types. However, equivalent cytotoxicity is achieved over a wide range of doses, although the reasons for this differential sensitivity are not always clear. In this study, three kinds of cells, the 293T cell line, primary fibroblasts, and terminally differentiated myocardial cells, were treated with a wide range of H2O2 doses. Times to apoptosis initiation and end were measured cytochemically and the changes in expression of caspase-9, P53, NF-κB, and RIP were determined by RT-PCR. The 293T cell line was the most sensitive to H2O2, undergoing necroptosis and/or apoptosis at all concentrations from 0.1 to 1.6 mM. At > 0.4 mM, H2O2 also caused necroptosis in primary cells. At < 0.4 mM, however, primary cells exhibited classic signs of apoptosis, although they tended to survive for 36 hours in < 0.2 mM H2O2. Thus, H2O2 is a broadly effective apoptosis inducer, but the dose range differs by cell type. For cell lines, a low dose is required and the exposure time must be reduced compared to primary cells to avoid cell death primarily by necroptosis or necrosis. PMID:27595106

  12. Is Hydrogen Peroxide a Suitable Apoptosis Inducer for All Cell Types?

    PubMed Central

    Xiang, Jinmei; Wan, Chunyun; Guo, Rui

    2016-01-01

    Hydrogen peroxide is currently the most widely used apoptosis inducer due to its broad cytotoxic efficacy against nearly all cell types. However, equivalent cytotoxicity is achieved over a wide range of doses, although the reasons for this differential sensitivity are not always clear. In this study, three kinds of cells, the 293T cell line, primary fibroblasts, and terminally differentiated myocardial cells, were treated with a wide range of H2O2 doses. Times to apoptosis initiation and end were measured cytochemically and the changes in expression of caspase-9, P53, NF-κB, and RIP were determined by RT-PCR. The 293T cell line was the most sensitive to H2O2, undergoing necroptosis and/or apoptosis at all concentrations from 0.1 to 1.6 mM. At > 0.4 mM, H2O2 also caused necroptosis in primary cells. At < 0.4 mM, however, primary cells exhibited classic signs of apoptosis, although they tended to survive for 36 hours in < 0.2 mM H2O2. Thus, H2O2 is a broadly effective apoptosis inducer, but the dose range differs by cell type. For cell lines, a low dose is required and the exposure time must be reduced compared to primary cells to avoid cell death primarily by necroptosis or necrosis.

  13. 21 CFR 184.1366 - Hydrogen peroxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Hydrogen peroxide. 184.1366 Section 184.1366 Food... GRAS § 184.1366 Hydrogen peroxide. (a) Hydrogen peroxide (H2O2, CAS Reg. No. 7722-84-1) is also... peroxide formed; by decomposition of barium peroxide with sulfuric or phosphoric acid; by...

  14. Degradation of bisphenol A and formation of hydrogen peroxide induced by glow discharge plasma in aqueous solutions.

    PubMed

    Wang, Lei; Jiang, Xuanzhen; Liu, Yongjun

    2008-06-15

    Degradation of bisphenol A (BPA) and simultaneous formation of hydrogen peroxide induced by glow discharge plasma in contact with aqueous solution were investigated. Experimental results indicated that the BPA degradation rate was higher in sodium chloride solution than that in sodium sulfate or phosphate solutions. However, the formation rates of hydrogen peroxide were on the opposite case. Both the BPA removal and the hydrogen peroxide production rates decreased in the presence of hydroxyl radical scavengers, indicating that hydroxyl radicals are the most probable oxidants responsible for BPA degradation and the precursors of hydrogen peroxide. Ferric ion showed better catalytic effect than that of ferrous ion, suggesting that the ferric ion was reduced by the intermediates formed during BPA degradation, which was confirmed by following the production of ferrous ion in the system. TOC of the solution gradually reduced with discharge time; however, without catalysts, the solution COD increased with discharge time and sharply decreased in the presence of iron salts. The major intermediate products were identified by LC/MS and the possible degradation mechanism was discussed. PMID:18082947

  15. Hydrogen peroxide inducible clone-5 mediates reactive oxygen species signaling for hepatocellular carcinoma progression.

    PubMed

    Wu, Jia-Ru; Hu, Chi-Tan; You, Ren-In; Pan, Siou-Mei; Cheng, Chuan-Chu; Lee, Ming-Che; Wu, Chao-Chuan; Chang, Yao-Jen; Lin, Shu-Chuan; Chen, Chang-Shan; Lin, Teng-Yi; Wu, Wen-Sheng

    2015-10-20

    One of the signaling components involved in hepatocellular carcinoma (HCC) progression is the focal adhesion adaptor paxillin. Hydrogen peroxide inducible clone-5 (Hic-5), one of the paralogs of paxillin, exhibits many biological functions distinct from paxillin, but may cooperate with paxillin to trigger tumor progression. Screening of Hic-5 in 145 surgical HCCs demonstrated overexpression of Hic-5 correlated well with intra- and extra-hepatic metastasis. Hic-5 highly expressed in the patient derived HCCs with high motility such as HCC329 and HCC353 but not in the HCCs with low motility such as HCC340. Blockade of Hic-5 expression prevented constitutive migration of HCC329 and HCC353 and HGF-induced cell migration of HCC340. HCC329Hic-5(-), HCC353Hic-5(-), HCC372Hic-5(-), the HCCs stably depleted of Hic-5, exhibited reduced motility compared with each HCC expressing Scramble shRNA. Moreover, intra/extrahepatic metastasis of HCC329Hic-5(-) in SCID mice greatly decreased compared with HCC329Scramble. On the other hand, ectopic Hic-5 expression in HCC340 promoted its progression. Constitutive and HGF-induced Hic-5 expression in HCCs were suppressed by the reactive oxygen species (ROS) scavengers catalase and dithiotheritol and c-Jun N-terminal kinase (JNK) inhibitor SP600125. On the contrary, depletion of Hic-5 blocked constitutive and HGF-induced ROS generation and JNK phosphorylation in HCCs. Also, ectopic expression of Hic-5 enhanced ROS generation and JNK phosphorylation. These highlighted that Hic-5 plays a central role in the positive feedback ROS-JNK signal cascade. Finally, the Chinese herbal derived anti-HCC peptide LZ-8 suppressed constitutive Hic-5 expression and JNK phosphorylation. In conclusion, Hic-5 mediates ROS-JNK signaling and may serve as a therapeutic target for prevention of HCC progression. PMID:26416447

  16. Hydrogen peroxide inducible clone-5 mediates reactive oxygen species signaling for hepatocellular carcinoma progression

    PubMed Central

    Wu, Jia-Ru; Hu, Chi-Tan; You, Ren-In; Pan, Siou-Mei; Cheng, Chuan-Chu; Lee, Ming-Che; Wu, Chao-Chuan; Chang, Yao-Jen; Lin, Shu-Chuan; Chen, Chang-Shan; Lin, Teng-Yi; Wu, Wen-Sheng

    2015-01-01

    One of the signaling components involved in hepatocellular carcinoma (HCC) progression is the focal adhesion adaptor paxillin. Hydrogen peroxide inducible clone-5 (Hic-5), one of the paralogs of paxillin, exhibits many biological functions distinct from paxillin, but may cooperate with paxillin to trigger tumor progression. Screening of Hic-5 in 145 surgical HCCs demonstrated overexpression of Hic-5 correlated well with intra- and extra-hepatic metastasis. Hic-5 highly expressed in the patient derived HCCs with high motility such as HCC329 and HCC353 but not in the HCCs with low motility such as HCC340. Blockade of Hic-5 expression prevented constitutive migration of HCC329 and HCC353 and HGF-induced cell migration of HCC340. HCC329Hic-5(−), HCC353Hic-5(−), HCC372Hic-5(−), the HCCs stably depleted of Hic-5, exhibited reduced motility compared with each HCC expressing Scramble shRNA. Moreover, intra/extrahepatic metastasis of HCC329Hic-5(−) in SCID mice greatly decreased compared with HCC329Scramble. On the other hand, ectopic Hic-5 expression in HCC340 promoted its progression. Constitutive and HGF-induced Hic-5 expression in HCCs were suppressed by the reactive oxygen species (ROS) scavengers catalase and dithiotheritol and c-Jun N-terminal kinase (JNK) inhibitor SP600125. On the contrary, depletion of Hic-5 blocked constitutive and HGF-induced ROS generation and JNK phosphorylation in HCCs. Also, ectopic expression of Hic-5 enhanced ROS generation and JNK phosphorylation. These highlighted that Hic-5 plays a central role in the positive feedback ROS-JNK signal cascade. Finally, the Chinese herbal derived anti-HCC peptide LZ-8 suppressed constitutive Hic-5 expression and JNK phosphorylation. In conclusion, Hic-5 mediates ROS-JNK signaling and may serve as a therapeutic target for prevention of HCC progression. PMID:26416447

  17. Hydrogen peroxide inducible clone-5 mediates reactive oxygen species signaling for hepatocellular carcinoma progression.

    PubMed

    Wu, Jia-Ru; Hu, Chi-Tan; You, Ren-In; Pan, Siou-Mei; Cheng, Chuan-Chu; Lee, Ming-Che; Wu, Chao-Chuan; Chang, Yao-Jen; Lin, Shu-Chuan; Chen, Chang-Shan; Lin, Teng-Yi; Wu, Wen-Sheng

    2015-10-20

    One of the signaling components involved in hepatocellular carcinoma (HCC) progression is the focal adhesion adaptor paxillin. Hydrogen peroxide inducible clone-5 (Hic-5), one of the paralogs of paxillin, exhibits many biological functions distinct from paxillin, but may cooperate with paxillin to trigger tumor progression. Screening of Hic-5 in 145 surgical HCCs demonstrated overexpression of Hic-5 correlated well with intra- and extra-hepatic metastasis. Hic-5 highly expressed in the patient derived HCCs with high motility such as HCC329 and HCC353 but not in the HCCs with low motility such as HCC340. Blockade of Hic-5 expression prevented constitutive migration of HCC329 and HCC353 and HGF-induced cell migration of HCC340. HCC329Hic-5(-), HCC353Hic-5(-), HCC372Hic-5(-), the HCCs stably depleted of Hic-5, exhibited reduced motility compared with each HCC expressing Scramble shRNA. Moreover, intra/extrahepatic metastasis of HCC329Hic-5(-) in SCID mice greatly decreased compared with HCC329Scramble. On the other hand, ectopic Hic-5 expression in HCC340 promoted its progression. Constitutive and HGF-induced Hic-5 expression in HCCs were suppressed by the reactive oxygen species (ROS) scavengers catalase and dithiotheritol and c-Jun N-terminal kinase (JNK) inhibitor SP600125. On the contrary, depletion of Hic-5 blocked constitutive and HGF-induced ROS generation and JNK phosphorylation in HCCs. Also, ectopic expression of Hic-5 enhanced ROS generation and JNK phosphorylation. These highlighted that Hic-5 plays a central role in the positive feedback ROS-JNK signal cascade. Finally, the Chinese herbal derived anti-HCC peptide LZ-8 suppressed constitutive Hic-5 expression and JNK phosphorylation. In conclusion, Hic-5 mediates ROS-JNK signaling and may serve as a therapeutic target for prevention of HCC progression.

  18. Stabilized aqueous hydrogen peroxide solution

    SciTech Connect

    Malin, M.J.; Sciafani, L.D.

    1988-05-17

    This patent describes a stabilized aqueous hydrogen peroxide solution having a pH below 7 and an amount of Ferric ion up to about 2 ppm comprising hydrogen peroxide, acetanilide having a concentration which ranges between 0.74 M Mol/L and 2.22 mMol/L, and o-benzene disulfonic acid or salt thereof at a concentration between about 0.86 mMol/L to about 1.62 mMol/L.

  19. Salicylic acid-induced superoxide generation catalyzed by plant peroxidase in hydrogen peroxide-independent manner.

    PubMed

    Kimura, Makoto; Kawano, Tomonori

    2015-01-01

    It has been reported that salicylic acid (SA) induces both immediate spike and long lasting phases of oxidative burst represented by the generation of reactive oxygen species (ROS) such as superoxide anion radical (O2(•-)). In general, in the earlier phase of oxidative burst, apoplastic peroxidase are likely involved and in the late phase of the oxidative burst, NADPH oxidase is likely involved. Key signaling events connecting the 2 phases of oxidative burst are calcium channel activation and protein phosphorylation events. To date, the known earliest signaling event in response to exogenously added SA is the cell wall peroxidase-catalyzed generation of O2(•-) in a hydrogen peroxide (H2O2)-dependent manner. However, this model is incomplete since the source of the initially required H2O2 could not be explained. Based on the recently proposed role for H2O2-independent mechanism for ROS production catalyzed by plant peroxidases (Kimura et al., 2014, Frontiers in Plant Science), we hereby propose a novel model for plant peroxidase-catalyzed oxidative burst fueled by SA.

  20. Chemometric analysis of spectroscopic data on shape evolution of silver nanoparticles induced by hydrogen peroxide.

    PubMed

    Wongravee, Kanet; Parnklang, Tewarak; Pienpinijtham, Prompong; Lertvachirapaiboon, Chutiparn; Ozaki, Yukihiro; Thammacharoen, Chuchaat; Ekgasit, Sanong

    2013-03-28

    The study on the shape evolution of metal nanoparticles (MNPs) is crucial to gain an understanding on controlling the shape and size of metal nanostructures. In this work, a detailed study on shape evolution of silver (Ag) nanospheres to nanoplates induced by hydrogen peroxide (H2O2) was performed. According to the growth mechanism of Ag nanoplates, the spectrophotometric method combined with chemometric analysis has potential to reveal the structural evolution process as observed by surface plasmon resonance phenomena. The extinction spectra of the evolving nanostructures were analyzed by factor analysis and error indicator functions. Five major components attributed to the different particle shapes and sizes were theoretically predicted. Furthermore, the concentration profiles and pure spectra of these components were resolved using multivariate curve resolution-alternative least squares (MCR-ALS) analysis. The evolution profiles show that the spherical Ag particles systematically evolved into plate structures of different sizes. Larger nanoplates were obtained when higher concentrations of H2O2 were employed. An evidence of nanoplate disintegration was observed when a large amount of H2O2 was employed. The predicted structural morphologies of each component given by chemometric calculation were in excellent agreement with those observed by transmission electron microscope (TEM) images.

  1. Protective Effects of Costunolide against Hydrogen Peroxide-Induced Injury in PC12 Cells.

    PubMed

    Cheong, Chong-Un; Yeh, Ching-Sheng; Hsieh, Yi-Wen; Lee, Ying-Ray; Lin, Mei-Ying; Chen, Chung-Yi; Lee, Chien-Hsing

    2016-01-01

    Oxidative stress-mediated cellular injury has been considered as a major cause of neurodegenerative diseases including Alzheimer's and Parkinson's diseases. The scavenging of reactive oxygen species (ROS) mediated by antioxidants may be a potential strategy for retarding the diseases' progression. Costunolide (CS) is a well-known sesquiterpene lactone, used as a popular herbal remedy, which possesses anti-inflammatory and antioxidant activity. This study aimed to investigate the protective role of CS against the cytotoxicity induced by hydrogen peroxide (H₂O₂) and to elucidate potential protective mechanisms in PC12 cells. The results showed that the treatment of PC12 cells with CS prior to H₂O₂ exposure effectively increased the cell viability. Furthermore, it decreased the intracellular ROS, stabilized the mitochondria membrane potential (MMP), and reduced apoptosis-related protein such as caspase 3. In addition, CS treatment attenuated the cell injury by H₂O₂ through the inhibition of phosphorylation of p38 and the extracellular signal-regulated kinase (ERK). These results demonstrated that CS is promising as a potential therapeutic candidate for neurodegenerative diseases resulting from oxidative damage and further research on this topic should be encouraged. PMID:27409597

  2. Role of hydrogen peroxide in NF-kappaB activation: from inducer to modulator.

    PubMed

    Oliveira-Marques, Virgínia; Marinho, H Susana; Cyrne, Luísa; Antunes, Fernando

    2009-09-01

    Hydrogen peroxide (H2O2) has been implicated in the regulation of the transcription factor NF-kappaB, a key regulator of the inflammatory process and adaptive immunity. However, no consensus exists regarding the regulatory role played by H2O2. We discuss how the experimental methodologies used to expose cells to H2O2 produce inconsistent results that are difficult to compare, and how the steady-state titration with H2O2 emerges as an adequate tool to overcome these problems. The redox targets of H2O2 in the NF-kappaB pathway--from the membrane to the post-translational modifications in both NF-kappaB and histones in the nucleus--are described. We also review how H2O2 acts as a specific regulator at the level of the single gene, and briefly discuss the implications of this regulation for human health in the context of kappaB polymorphisms. In conclusion, after near 30 years of research, H2O2 emerges not as an inducer of NF-kappaB, but as an agent able to modulate the activation of the NF-kappaB pathway by other agents. This modulation is generic at the level of the whole pathway but specific at the level of the single gene. Therefore, H2O2 is a fine-tuning regulator of NF-kappaB-dependent processes, as exemplified by its dual regulation of inflammation. PMID:19496701

  3. Role of hydrogen peroxide in NF-kappaB activation: from inducer to modulator.

    PubMed

    Oliveira-Marques, Virgínia; Marinho, H Susana; Cyrne, Luísa; Antunes, Fernando

    2009-09-01

    Hydrogen peroxide (H2O2) has been implicated in the regulation of the transcription factor NF-kappaB, a key regulator of the inflammatory process and adaptive immunity. However, no consensus exists regarding the regulatory role played by H2O2. We discuss how the experimental methodologies used to expose cells to H2O2 produce inconsistent results that are difficult to compare, and how the steady-state titration with H2O2 emerges as an adequate tool to overcome these problems. The redox targets of H2O2 in the NF-kappaB pathway--from the membrane to the post-translational modifications in both NF-kappaB and histones in the nucleus--are described. We also review how H2O2 acts as a specific regulator at the level of the single gene, and briefly discuss the implications of this regulation for human health in the context of kappaB polymorphisms. In conclusion, after near 30 years of research, H2O2 emerges not as an inducer of NF-kappaB, but as an agent able to modulate the activation of the NF-kappaB pathway by other agents. This modulation is generic at the level of the whole pathway but specific at the level of the single gene. Therefore, H2O2 is a fine-tuning regulator of NF-kappaB-dependent processes, as exemplified by its dual regulation of inflammation.

  4. Myocardial infarction induces cognitive impairment by increasing the production of hydrogen peroxide in adult rat hippocampus.

    PubMed

    Liu, Chunhua; Liu, Ye; Yang, Zhuo

    2014-02-01

    Accumulating clinical evidence has shown a causal relationship between heart diseases and cognitive impairment in clinical, but the underlying mechanism remains unclear. In this study, rats with myocardial infarction (MI) were used to investigate cognition-related synaptic function and proteins. Adult male Wistar rats were subjected to MI by ligating of left anterior descending artery (LAD) and the infarct size of rat heart was measured by 2,3,5-triphenyltetrazoium chloride (TTC) staining. In this study, results showed that compared with control group, long-term potentiation was suppressed in dentate gyrus area, the contents of hydrogen peroxide (H2O2) and malondialdehyde were significantly increased, whereas the Cu/Zn-superoxide dismutase activity and N-methyl-d-aspartate receptor subunit 2B were attenuated in hippocampus of MI rats. Interestingly, it was observed that the PI3K/Akt pathway was activated in MI rats. Therefore, this study suggests that H2O2 plays an important role in cognitive dysfunction induced by MI.

  5. Streptococcus oralis Induces Lysosomal Impairment of Macrophages via Bacterial Hydrogen Peroxide.

    PubMed

    Okahashi, Nobuo; Nakata, Masanobu; Kuwata, Hirotaka; Kawabata, Shigetada

    2016-07-01

    Streptococcus oralis, an oral commensal, belongs to the mitis group of streptococci and occasionally causes opportunistic infections, such as bacterial endocarditis and bacteremia. Recently, we found that the hydrogen peroxide (H2O2) produced by S. oralis is sufficient to kill human monocytes and epithelial cells, implying that streptococcal H2O2 is a cytotoxin. In the present study, we investigated whether streptococcal H2O2 impacts lysosomes, organelles of the intracellular digestive system, in relation to cell death. S. oralis infection induced the death of RAW 264 macrophages in an H2O2-dependent manner, which was exemplified by the fact that exogenous H2O2 also induced cell death. Infection with either a mutant lacking spxB, which encodes pyruvate oxidase responsible for H2O2 production, or Streptococcus mutans, which does not produce H2O2, showed less cytotoxicity. Visualization of lysosomes with LysoTracker revealed lysosome deacidification after infection with S. oralis or exposure to H2O2, which was corroborated by acridine orange staining. Similarly, fluorescent labeling of lysosome-associated membrane protein-1 gradually disappeared during infection with S. oralis or exposure to H2O2 The deacidification and the following induction of cell death were inhibited by chelating iron in lysosomes. Moreover, fluorescent staining of cathepsin B indicated lysosomal destruction. However, treatment of infected cells with a specific inhibitor of cathepsin B had negligible effects on cell death; instead, it suppressed the detachment of dead cells from the culture plates. These results suggest that streptococcal H2O2 induces cell death with lysosomal destruction and then the released lysosomal cathepsins contribute to the detachment of the dead cells. PMID:27113357

  6. 21 CFR 173.356 - Hydrogen peroxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Hydrogen peroxide. 173.356 Section 173.356 Food... Specific Usage Additives § 173.356 Hydrogen peroxide. Hydrogen peroxide (CAS Reg. No. 7722-84-1) may be... to exceed 0.001 percent by weight of the whey, providing that residual hydrogen peroxide is...

  7. 21 CFR 173.356 - Hydrogen peroxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Hydrogen peroxide. 173.356 Section 173.356 Food... Specific Usage Additives § 173.356 Hydrogen peroxide. Hydrogen peroxide (CAS Reg. No. 7722-84-1) may be... to exceed 0.001 percent by weight of the whey, providing that residual hydrogen peroxide is...

  8. 21 CFR 173.356 - Hydrogen peroxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Hydrogen peroxide. 173.356 Section 173.356 Food... Specific Usage Additives § 173.356 Hydrogen peroxide. Hydrogen peroxide (CAS Reg. No. 7722-84-1) may be... to exceed 0.001 percent by weight of the whey, providing that residual hydrogen peroxide is...

  9. Electrochemical and spectroscopic studies of ssDNA damage induced by hydrogen peroxide using graphene based nanomaterials.

    PubMed

    Berghian-Grosan, Camelia; Biris, Alexandru Radu; Coros, Maria; Pogacean, Florina; Pruneanu, Stela

    2015-06-01

    The oxidative damage of deoxyribonucleic acid (DNA) has been intensively studied due to its role in the occurrence of some diseases. The hydrogen peroxide (H2O2) is one of the reactive oxygen species (ROS). It can induce oxidation of DNA bases, sugar lesions or DNA strand breaks. The Pt/Gr-Au-3 modified electrode was employed for the analysis of four ssDNA samples: single-stranded DNA (ssDNA), ssDNA pre-treated with hydrogen peroxide (ssDNA-H2O2), ssDNA pre-treated with graphene-gold nanoparticles (ssDNA-Gr-Au) and ssDNA-Gr-Au complex pre-treated with hydrogen peroxide (ssDNA-Gr-Au-H2O2). By monitoring the changes of the purine oxidation peaks currents, we obtained valuable information about the damage induced by the hydrogen peroxide onto the un-treated or graphene pre-treated ssDNA and also about the interaction between ssDNA and graphene-based nanomaterial. The FTIR analysis has been also used to obtain information about the ssDNA damage. These findings allowed us to prove the utility of graphene-based nanomaterials (mainly Gr-Au-3) not only for the investigation of the oxidative damage induced by a non-radical oxidant, but also for the determination of the type of interaction between ssDNA and graphene surface. The stability of the ssDNA-Gr-Au-3 complex against the damage induced by H2O2, in the absence of reduced transition metals, was also established.

  10. Subtoxic levels hydrogen peroxide-induced expression of interleukin-6 by epidermal melanocytes.

    PubMed

    Yao, Lei; Hu, Dan-Ning; Chen, Min; Li, Shan-Shan

    2012-12-01

    Oxidative stress and autoimmune reaction are involved in the pathogenesis of vitiligo. Levels of hydrogen peroxide (H(2)O(2)) and interleukin-6 (IL-6), a proinflammation cytokine and a key factor in the pathogenesis of autoimmune diseases, have been reported to be elevated in vitiligo lesions. The objective of this study was to evaluate the effects of subtoxic levels of H(2)O(2) on the expression of IL-6 by cultured human epidermal melanocytes and to explore the relevant signal pathways. Cultured human melanocytes were stimulated with of H(2)O(2) at subtoxic levels. Levels of IL-6 protein in the medium and IL-6 mRNA in the cells were measured by IL-6 ELISA analysis and RT-PCR, respectively. NF-κB and phosphorylated p38 mitogen-activated protein kinase (MAPK), ERK and JNK in cells cultured with and without H(2)O(2) were measured by relevant ELISA kits. In cultured melanocytes, subtoxic levels of H(2)O(2) (30-300 μM) significantly increased the IL-6 mRNA and protein levels in a dose-dependent manner. NF-κB in nuclear extracts and phosphorylated p38 MAPK levels in cell lysates were significantly increased in H(2)O(2) treated cells. Pretreatment of cells with inhibitors of p38 MAPK (SB203580) and NF-κB (BAY11-7082), but not inhibitors of ERK (UO1026) and JNK (SP600125), abolished H(2)O(2)-induced expression of IL-6. H(2)O(2)-induced overexpression of IL-6 by melanocytes may be a molecular linkage for the oxidative stress and inflammatory/autoimmune reactions in vitiligo and may provide a novel target for the treatment of vitiligo.

  11. Hydrogen peroxide-inducible clone-5 regulates mesangial cell proliferation in proliferative glomerulonephritis in mice.

    PubMed

    Jamba, Ariunbold; Kondo, Shuji; Urushihara, Maki; Nagai, Takashi; Kim-Kaneyama, Joo-Ri; Miyazaki, Akira; Kagami, Shoji

    2015-01-01

    Hydrogen peroxide-inducible clone-5 (Hic-5) is a transforming growth factor (TGF)-β1-inducible focal adhesion protein. We previously demonstrated that Hic-5 was localized in mesangial cells and its expression was associated with glomerular cell proliferation and matrix expansion in human and rat glomerulonephritis (GN). In the present study, we first assessed the role of Hic-5 in mesangioproliferative GN by injecting Habu venom into heminephrectomized wild type (Hic-5+/+) and Hic-5-deficient (Hic-5-/-) mice. Hic-5+/+ GN mice exhibited glomerular cell proliferation on day 7. Surprisingly, glomerular cell number and Ki-67-positive cells in Hic-5-/- GN mice were significantly greater than those in Hic-5+/+ GN mice on day 7, although the number of glomerular apoptotic cells and the expression of growth factors (platelet-derived growth factor-BB and TGF-β1) and their receptors were similarly increased in both Hic-5+/+ and Hic-5-/- GN mice. In culture experiments, proliferation assays showed that platelet-derived growth factor-BB and TGF-β1 enhanced the proliferation of Hic-5-/- mesangial cells compared with Hic-5+/+ mesangial cells. In addition, mitogenic regulation by Hic-5 was associated with altered and coordinated expression of cell cycle-related proteins including cyclin D1 and p21. The present results suggest that Hic-5 might regulate mesangial cell proliferation in proliferative GN in mice. In conclusion, modulation of Hic-5 expression might have a potential to prevent mesangial cell proliferation in the acute mitogenic phase of glomerulonephritis.

  12. Heterotrimeric G protein mediates ethylene-induced stomatal closure via hydrogen peroxide synthesis in Arabidopsis.

    PubMed

    Ge, Xiao-Min; Cai, Hong-Li; Lei, Xue; Zhou, Xue; Yue, Ming; He, Jun-Min

    2015-04-01

    Heterotrimeric G proteins function as key players in hydrogen peroxide (H2O2) production in plant cells, but whether G proteins mediate ethylene-induced H2O2 production and stomatal closure are not clear. Here, evidences are provided to show the Gα subunit GPA1 as a missing link between ethylene and H2O2 in guard cell ethylene signalling. In wild-type leaves, ethylene-triggered H2O2 synthesis and stomatal closure were dependent on activation of Gα. GPA1 mutants showed the defect of ethylene-induced H2O2 production and stomatal closure, whereas wGα and cGα overexpression lines showed faster stomatal closure and H2O2 production in response to ethylene. Ethylene-triggered H2O2 generation and stomatal closure were impaired in RAN1, ETR1, ERS1 and EIN4 mutants but not impaired in ETR2 and ERS2 mutants. Gα activator and H2O2 rescued the defect of RAN1 and EIN4 mutants or etr1-3 in ethylene-induced H2O2 production and stomatal closure, but only rescued the defect of ERS1 mutants or etr1-1 and etr1-9 in ethylene-induced H2O2 production. Stomata of CTR1 mutants showed constitutive H2O2 production and stomatal closure, but which could be abolished by Gα inhibitor. Stomata of EIN2, EIN3 and ARR2 mutants did not close in responses to ethylene, Gα activator or H2O2, but do generate H2O2 following challenge of ethylene or Gα activator. The data indicate that Gα mediates ethylene-induced stomatal closure via H2O2 production, and acts downstream of RAN1, ETR1, ERS1, EIN4 and CTR1 and upstream of EIN2, EIN3 and ARR2. The data also show that ETR1 and ERS1 mediate both ethylene and H2O2 signalling in guard cells.

  13. Mechanisms of Sb(III) oxidation by pyrite-induced hydroxyl radicals and hydrogen peroxide.

    PubMed

    Kong, Linghao; Hu, Xingyun; He, Mengchang

    2015-03-17

    Antimony (Sb) is an element of growing interest, and its toxicity and mobility are strongly influenced by redox processes. Sb(III) oxidation mechanisms in pyrite suspensions were comprehensively investigated by kinetic measurements in oxic and anoxic conditions and simulated sunlight. Sb(III) was oxidized to Sb(V) in both solution and on pyrite surfaces in oxic conditions; the oxidation efficiency of Sb(III) was gradually enhanced with the increase of pH. The pyrite-induced hydroxyl radical (·OH) and hydrogen peroxide (H2O2) are the oxidants for Sb(III) oxidation. ·OH is the oxidant for Sb(III) oxidation in acidic solutions, and H2O2 becomes the main oxidant in neutral and alkaline solutions. ·OH and H2O2 can be generated by the reaction of previously existing FeIII(pyrite) and H2O on pyrite in anoxic conditions. The oxygen molecule is the crucial factor in continuously producing ·OH and H2O2 for Sb(III) oxidation. The efficiency of Sb(III) oxidation was enhanced in surface-oxidized pyrite (SOP) suspension, more ·OH formed through Fenton reaction in acidic solutions, but Fe(IV) and H2O2 were formed in neutral and alkaline solutions. Under the illumination of simulated sunlight, more ·OH and H2O2 were produced in the pyrite suspension, and the oxidation efficiency of Sb(III) was remarkably enhanced. In conclusion, Sb(III) can be oxidized to Sb(V) in the presence of pyrite, which will greatly influence the fate of Sb(III) in the environment.

  14. 21 CFR 529.1150 - Hydrogen peroxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Hydrogen peroxide. 529.1150 Section 529.1150 Food... peroxide. (a) Specifications. Each milliliter of solution contains 396.1 milligrams (mg) hydrogen peroxide... group. Eggs: Some strains of rainbow trout eggs are sensitive to hydrogen peroxide treatment at a...

  15. 21 CFR 173.356 - Hydrogen peroxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Hydrogen peroxide. 173.356 Section 173.356 Food... peroxide. Hydrogen peroxide (CAS Reg. No. 7722-84-1) may be safely used to treat food in accordance with..., providing that residual hydrogen peroxide is removed by appropriate chemical or physical means during...

  16. 21 CFR 529.1150 - Hydrogen peroxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Hydrogen peroxide. 529.1150 Section 529.1150 Food... peroxide. (a) Specifications. Each milliliter of solution contains 396.1 milligrams (mg) hydrogen peroxide... group. Eggs: Some strains of rainbow trout eggs are sensitive to hydrogen peroxide treatment at a...

  17. 21 CFR 529.1150 - Hydrogen peroxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Hydrogen peroxide. 529.1150 Section 529.1150 Food... peroxide. (a) Specifications. Each milliliter of solution contains 396.1 milligrams (mg) hydrogen peroxide... group. Eggs: Some strains of rainbow trout eggs are sensitive to hydrogen peroxide treatment at a...

  18. 21 CFR 529.1150 - Hydrogen peroxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Hydrogen peroxide. 529.1150 Section 529.1150 Food... peroxide. (a) Specifications. Each milliliter of solution contains 396.1 milligrams (mg) hydrogen peroxide... group. Eggs: Some strains of rainbow trout eggs are sensitive to hydrogen peroxide treatment at a...

  19. 21 CFR 529.1150 - Hydrogen peroxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Hydrogen peroxide. 529.1150 Section 529.1150 Food... peroxide. (a) Specifications. Each milliliter of solution contains 396.1 milligrams (mg) hydrogen peroxide... group. Eggs: Some strains of rainbow trout eggs are sensitive to hydrogen peroxide treatment at a...

  20. Zinc carnosine protects against hydrogen peroxide-induced DNA damage in WIL2-NS lymphoblastoid cell line independent of poly (ADP-Ribose) polymerase expression.

    PubMed

    Ooi, Theng Choon; Mohammad, Nur Hafiza; Sharif, Razinah

    2014-12-01

    The aim of this study is to investigate the ability of zinc carnosine to protect the human lymphoblastoid (WIL2-NS) cell line from hydrogen peroxide-induced DNA damage. Cells were cultured with medium containing zinc carnosine at the concentrations of 0.4, 4, 16 and 32 μM for 9 days prior to treatment with 30 μM of hydrogen peroxide (30 min). Zinc carnosine at the concentration 16 μM was optimal in protecting cells from hydrogen peroxide-induced cytotoxicity and gave the lowest percentage of apoptotic and necrotic cells. Results showed that zinc carnosine was able to induce glutathione production and protect cells from hydrogen peroxide-induced oxidative stress at all concentration and the highest protection was observed at 32-μM zinc carnosine culture. Cytokinesis-block micronucleus cytome assay showed that cells cultured with 4-32 μM of zinc carnosine showed significant reduction in micronuclei formation, nucleoplasmic bridges and nuclear bud frequencies (p < 0.05), suggesting that these concentrations maybe optimal in protecting cells from hydrogen peroxide-induced DNA damage. However, after being challenged with hydrogen peroxide, no increase in poly(ADP-ribose) polymerase expression was observed. Thus, results from this study demonstrate that zinc carnosines possess antioxidant properties and are able to reduce hydrogen peroxide-induced DNA damage in vitro independent of poly(ADP-ribose) polymerase. Further studies are warranted to understand the mechanism of protection of zinc carnosine against hydrogen peroxide-induced damage.

  1. Progress toward hydrogen peroxide micropulsion

    SciTech Connect

    Whitehead, J C; Dittman, M D; Ledebuhr, A G

    1999-07-08

    A new self-pressurizing propulsion system has liquid thrusters and gas jet attitude control without heavy gas storage vessels. A pump boosts the pressure of a small fraction of the hydrogen peroxide, so that reacted propellant can controllably pressurize its own source tank. The warm decomposition gas also powers the pump and is supplied to the attitude control jets. The system has been incorporated into a prototype microsatellite for terrestrial maneuvering tests. Additional progress includes preliminary testing of a bipropellant thruster, and storage of unstabilized hydrogen peroxide in small sealed tanks.

  2. Differential Gene Expression Patterns in Chicken Cardiomyocytes during Hydrogen Peroxide-Induced Apoptosis

    PubMed Central

    Li, Youwen; Guo, Dingzong

    2016-01-01

    Hydrogen peroxide (H2O2) is both an exogenous and endogenous cytotoxic agent that can reliably induce apoptosis in numerous cell types for studies on apoptosis signaling pathways. However, little is known of these apoptotic processes in myocardial cells of chicken, a species prone to progressive heart failure. Sequencing of mRNA transcripts (RNA-Seq) allows for the identification of differentially expressed genes under various physiological and pathological conditions to elucidate the molecular pathways involved, including cellular responses to exogenous and endogenous toxins. We used RNA-seq to examine genes differentially expressed during H2O2-induced apoptosis in primary cultures of embryonic chicken cardiomyocytes. Following control or H2O2 treatment, RNA was extracted and sequencing performed to identify novel transcripts up- or downregulated in the H2O2 treatment group and construct protein−protein interaction networks. Of the 19,268 known and 2,160 novel transcripts identified in both control and H2O2 treatment groups, 4,650 showed significant differential expression. Among them, 55.63% were upregulated and 44.37% downregulated. Initiation of apoptosis by H2O2 was associated with upregulation of caspase-8, caspase-9, and caspase-3, and downregulation of anti-apoptotic genes API5 and TRIA1. Many other differentially expressed genes were associated with metabolic pathways (including ‘Fatty acid metabolism’, ‘Alanine, aspartate, and glutamate metabolism’, and ‘Biosynthesis of unsaturated fatty acids’) and cell signaling pathways (including ‘PPAR signaling pathway’, ‘Adipocytokine signaling pathway’, ‘TGF-beta signaling pathway’, ‘MAPK signaling pathway’, and ‘p53 signaling pathway’). In chicken cardiomyocytes, H2O2 alters the expression of numerous genes linked to cell signaling and metabolism as well as genes directly associated with apoptosis. In particular, H2O2 also affects the biosynthesis and processing of proteins and

  3. Hydrogen Peroxide Induced Cell Death: The Major Defences Relative Roles and Consequences in E. coli.

    PubMed

    Uhl, Lionel; Dukan, Sam

    2016-01-01

    We recently developed a mathematical model for predicting reactive oxygen species (ROS) concentration and macromolecules oxidation in vivo. We constructed such a model using Escherichia coli as a model organism and a set of ordinary differential equations. In order to evaluate the major defences relative roles against hydrogen peroxide (H2 O2), we investigated the relative contributions of the various reactions to the dynamic system and searched for approximate analytical solutions for the explicit expression of changes in H2 O2 internal or external concentrations. Although the key actors in cell defence are enzymes and membrane, a detailed analysis shows that their involvement depends on the H2 O2 concentration level. Actually, the impact of the membrane upon the H2 O2 stress felt by the cell is greater when micromolar H2 O2 is present (9-fold less H2 O2 in the cell than out of the cell) than when millimolar H2 O2 is present (about 2-fold less H2 O2 in the cell than out of the cell). The ratio between maximal external H2 O2 and internal H2 O2 concentration also changes, reducing from 8 to 2 while external H2 O2 concentration increases from micromolar to millimolar. This non-linear behaviour mainly occurs because of the switch in the predominant scavenger from Ahp (Alkyl Hydroperoxide Reductase) to Cat (catalase). The phenomenon changes the internal H2 O2 maximal concentration, which surprisingly does not depend on cell density. The external H2 O2 half-life and the cumulative internal H2 O2 exposure do depend upon cell density. Based on these analyses and in order to introduce a concept of dose response relationship for H2 O2-induced cell death, we developed the concepts of "maximal internal H2 O2 concentration" and "cumulative internal H2 O2 concentration" (e.g. the total amount of H2 O2). We predict that cumulative internal H2 O2 concentration is responsible for the H2 O2-mediated death of bacterial cells. PMID:27494019

  4. Hydrogen Peroxide Induced Cell Death: The Major Defences Relative Roles and Consequences in E. coli

    PubMed Central

    Uhl, Lionel; Dukan, Sam

    2016-01-01

    We recently developed a mathematical model for predicting reactive oxygen species (ROS) concentration and macromolecules oxidation in vivo. We constructed such a model using Escherichia coli as a model organism and a set of ordinary differential equations. In order to evaluate the major defences relative roles against hydrogen peroxide (H2 O2), we investigated the relative contributions of the various reactions to the dynamic system and searched for approximate analytical solutions for the explicit expression of changes in H2 O2 internal or external concentrations. Although the key actors in cell defence are enzymes and membrane, a detailed analysis shows that their involvement depends on the H2 O2 concentration level. Actually, the impact of the membrane upon the H2 O2 stress felt by the cell is greater when micromolar H2 O2 is present (9-fold less H2 O2 in the cell than out of the cell) than when millimolar H2 O2 is present (about 2-fold less H2 O2 in the cell than out of the cell). The ratio between maximal external H2 O2 and internal H2 O2 concentration also changes, reducing from 8 to 2 while external H2 O2 concentration increases from micromolar to millimolar. This non-linear behaviour mainly occurs because of the switch in the predominant scavenger from Ahp (Alkyl Hydroperoxide Reductase) to Cat (catalase). The phenomenon changes the internal H2 O2 maximal concentration, which surprisingly does not depend on cell density. The external H2 O2 half-life and the cumulative internal H2 O2 exposure do depend upon cell density. Based on these analyses and in order to introduce a concept of dose response relationship for H2 O2-induced cell death, we developed the concepts of “maximal internal H2 O2 concentration” and “cumulative internal H2 O2 concentration” (e.g. the total amount of H2 O2). We predict that cumulative internal H2 O2 concentration is responsible for the H2 O2-mediated death of bacterial cells. PMID:27494019

  5. Hydrogen peroxide induces activation of insulin signaling pathway via AMP-dependent kinase in podocytes

    SciTech Connect

    Piwkowska, Agnieszka; Rogacka, Dorota; Angielski, Stefan; Jankowski, Maciej

    2012-11-09

    Highlights: Black-Right-Pointing-Pointer H{sub 2}O{sub 2} activates the insulin signaling pathway and glucose uptake in podocytes. Black-Right-Pointing-Pointer H{sub 2}O{sub 2} induces time-dependent changes in AMPK phosphorylation. Black-Right-Pointing-Pointer H{sub 2}O{sub 2} enhances insulin signaling pathways via AMPK activation. Black-Right-Pointing-Pointer H{sub 2}O{sub 2} stimulation of glucose uptake is AMPK-dependent. -- Abstract: Podocytes are cells that form the glomerular filtration barrier in the kidney. Insulin signaling in podocytes is critical for normal kidney function. Insulin signaling is regulated by oxidative stress and intracellular energy levels. We cultured rat podocytes to investigate the effects of hydrogen peroxide (H{sub 2}O{sub 2}) on the phosphorylation of proximal and distal elements of insulin signaling. We also investigated H{sub 2}O{sub 2}-induced intracellular changes in the distribution of protein kinase B (Akt). Western blots showed that H{sub 2}O{sub 2} (100 {mu}M) induced rapid, transient phosphorylation of the insulin receptor (IR), the IR substrate-1 (IRS1), and Akt with peak activities at 5 min ({Delta} 183%, P < 0.05), 3 min ({Delta} 414%, P < 0.05), and 10 min ({Delta} 35%, P < 0.05), respectively. Immunostaining cells with an Akt-specific antibody showed increased intensity at the plasma membrane after treatment with H{sub 2}O{sub 2}>. Furthermore, H{sub 2}O{sub 2} inhibited phosphorylation of the phosphatase and tensin homologue (PTEN; peak activity at 10 min; {Delta} -32%, P < 0.05) and stimulated phosphorylation of the AMP-dependent kinase alpha subunit (AMPK{alpha}; 78% at 3 min and 244% at 10 min). The stimulation of AMPK was abolished with an AMPK inhibitor, Compound C (100 {mu}M, 2 h). Moreover, Compound C significantly reduced the effect of H{sub 2}O{sub 2} on IR phosphorylation by about 40% (from 2.07 {+-} 0.28 to 1.28 {+-} 0.12, P < 0.05). In addition, H{sub 2}O{sub 2} increased glucose uptake in podocytes

  6. Exogenous low-dose hydrogen peroxide enhances drought tolerance of soybean (Glycine max L.) through inducing antioxidant system.

    PubMed

    Guler, Neslihan Saruhan; Pehlivan, Necla

    2016-06-01

    Hydrogen peroxide (H(2)O(2)) functions as a signal molecule in plants under abiotic and biotic stress. In this study, the role of exogenous H(2)O(2) in improving drought tolerance in two soybean cultivars (Glycine max L. Merrill) differing in their tolerance to drought was evaluated. Plants were grown in plastic pots with normal irrigation in a phytotron. Four weeks after radicle emergence, either 1 mM H(2)O(2) or distilled water was sprayed as foliar onto the leaves of each plant, after drought stress was applied. Leaf samples were harvested on the 4(th) and 7(th) days of the drought. Antioxidant-related enzyme activity, such as the superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), hydrogen peroxide (H(2)O(2)) and malondialdehyde (MDA) content was measured during the drought period. Drought stress decreased leaf water potential, relative water content and photosynthetic pigment content but enhanced lipid peroxidation and endogenous H(2)O(2) concentration. By contrast, exogenous low dose H(2)O(2) improved water status, pigment content and lipid peroxidation under drought stress. Endogenous H(2)O(2) concentration was reduced by exogenous H(2)O(2) as compared to drought treatment alone. H(2)O(2) pre-treatment induced all the antioxidant enzyme activities, to a greater extent than the control leaves, during drought. H(2)O(2) pretreatment further enhanced the activities of antioxidant enzymes in the tolerant cultivar compared to the sensitive cultivar. Results suggested that low dose H(2)O(2) pre-treatment alleviated water loss and H(2)O(2) content and increased drought stress tolerance by inducing the antioxidant system. PMID:27165528

  7. Exogenous low-dose hydrogen peroxide enhances drought tolerance of soybean (Glycine max L.) through inducing antioxidant system.

    PubMed

    Guler, Neslihan Saruhan; Pehlivan, Necla

    2016-06-01

    Hydrogen peroxide (H(2)O(2)) functions as a signal molecule in plants under abiotic and biotic stress. In this study, the role of exogenous H(2)O(2) in improving drought tolerance in two soybean cultivars (Glycine max L. Merrill) differing in their tolerance to drought was evaluated. Plants were grown in plastic pots with normal irrigation in a phytotron. Four weeks after radicle emergence, either 1 mM H(2)O(2) or distilled water was sprayed as foliar onto the leaves of each plant, after drought stress was applied. Leaf samples were harvested on the 4(th) and 7(th) days of the drought. Antioxidant-related enzyme activity, such as the superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), hydrogen peroxide (H(2)O(2)) and malondialdehyde (MDA) content was measured during the drought period. Drought stress decreased leaf water potential, relative water content and photosynthetic pigment content but enhanced lipid peroxidation and endogenous H(2)O(2) concentration. By contrast, exogenous low dose H(2)O(2) improved water status, pigment content and lipid peroxidation under drought stress. Endogenous H(2)O(2) concentration was reduced by exogenous H(2)O(2) as compared to drought treatment alone. H(2)O(2) pre-treatment induced all the antioxidant enzyme activities, to a greater extent than the control leaves, during drought. H(2)O(2) pretreatment further enhanced the activities of antioxidant enzymes in the tolerant cultivar compared to the sensitive cultivar. Results suggested that low dose H(2)O(2) pre-treatment alleviated water loss and H(2)O(2) content and increased drought stress tolerance by inducing the antioxidant system.

  8. Intraoperative Neurophysiological Evidence of Hydrogen Peroxide-Induced Stroke in Insular Tumor Surgery.

    PubMed

    León Jorba, Alba; López Cuiña, Miguel; Principe, Alessandro; Villalba Martínez, Gloria

    2015-01-01

    Hydrogen peroxide (H2O2) is commonly used as a haemostatic agent in all type of surgeries. Some adverse effects have been described related to its use. However, only very few cases are published in the literature of a stroke associated with the application of this agent directly to the brain. We present the case of a patient operated on for a right insular tumor with the assistance of intraoperative neurophysiological monitoring who developed a postoperative severe hemiparesis caused by a stroke in left middle cerebral artery territory due to the irrigation with H2O2. Based on this case, we recommend avoiding the H2O2 irrigation for hemostasis in surgery for brain tumors when vascular structures are exposed.

  9. Improved dual flow aluminum hydrogen peroxide battery

    NASA Astrophysics Data System (ADS)

    Marsh, Catherine; Licht, Stuart L.; Matthews, Donna

    1993-11-01

    A novel dual flow battery configuration is provided comprising an aqueous hydrogen peroxide catholyte, an aqueous anolyte, a porous solid electrocatalyst capable of reducing said hydrogen peroxide and separating said anolyte, and an aluminum anode positioned within said anolyte. Separation of catholyte and anolyte chambers prevents hydrogen peroxide poisoning of the aluminum anode.

  10. Improved dual flow aluminum hydrogen peroxide battery

    SciTech Connect

    Marsh, C.; Licht, S.L.; Matthews, D.

    1993-11-30

    A novel dual flow battery configuration is provided comprising an aqueous hydrogen peroxide catholyte, an aqueous anolyte, a porous solid electrocatalyst capable of reducing said hydrogen peroxide and separating said anolyte, and an aluminum anode positioned within said anolyte. Separation of catholyte and anolyte chambers prevents hydrogen peroxide poisoning of the aluminum anode.

  11. 21 CFR 582.1366 - Hydrogen peroxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Hydrogen peroxide. 582.1366 Section 582.1366 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1366 Hydrogen peroxide. (a) Product. Hydrogen peroxide. (b) (c) Limitations,...

  12. 21 CFR 582.1366 - Hydrogen peroxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Hydrogen peroxide. 582.1366 Section 582.1366 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1366 Hydrogen peroxide. (a) Product. Hydrogen peroxide. (b) (c) Limitations,...

  13. 21 CFR 582.1366 - Hydrogen peroxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Hydrogen peroxide. 582.1366 Section 582.1366 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1366 Hydrogen peroxide. (a) Product. Hydrogen peroxide. (b) (c) Limitations,...

  14. 21 CFR 582.1366 - Hydrogen peroxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Hydrogen peroxide. 582.1366 Section 582.1366 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1366 Hydrogen peroxide. (a) Product. Hydrogen peroxide. (b) (c) Limitations,...

  15. Sampling Stoichiometry: The Decomposition of Hydrogen Peroxide.

    ERIC Educational Resources Information Center

    Clift, Philip A.

    1992-01-01

    Describes a demonstration of the decomposition of hydrogen peroxide to provide an interesting, quantitative illustration of the stoichiometric relationship between the decomposition of hydrogen peroxide and the formation of oxygen gas. This 10-minute demonstration uses ordinary hydrogen peroxide and yeast that can be purchased in a supermarket.…

  16. 21 CFR 582.1366 - Hydrogen peroxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Hydrogen peroxide. 582.1366 Section 582.1366 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1366 Hydrogen peroxide. (a) Product. Hydrogen peroxide. (b) (c) Limitations,...

  17. Hydrogen peroxide induced cell death: One or two modes of action?

    PubMed

    Uhl, Lionel; Gerstel, Audrey; Chabalier, Maialène; Dukan, Sam

    2015-12-01

    Imlay and Linn show that exposure of logarithmically growing Escherichia coli to hydrogen peroxide (H2O2) leads to two kinetically distinguishable modes of cell killing. Mode one killing is pronounced near 1 mM concentration of H2O2 and is caused by DNA damage, whereas mode-two killing requires higher concentration ([Formula: see text]). The second mode seems to be essentially due to damage to all macromolecules. This phenomenon has also been observed in Fenton in vitro systems with DNA nicking caused by hydroxyl radical ([Formula: see text]). To our knowledge, there is currently no mathematical model for predicting mode one killing in vitro or in vivo after H2O2 exposure. We propose a simple model, using Escherichia coli as a model organism and a set of ordinary differential equations. Using this model, we show that available iron and cell density, two factors potentially involved in ROS dynamics, play a major role in the prediction of the experimental results obtained by our team and in previous studies. Indeed the presence of the mode one killing is strongly related to those two parameters. To our knowledge, mode-one death has not previously been explained. Imlay and Linn (Imlay and Linn, 1986) suggested that perhaps the amount of the toxic species was reduced at high concentrations of H2O2 because hydroxyl (or other) radicals might be quenched directly by hydrogen peroxide with the concomitant formation of superoxide anion (a less toxic species). We demonstrate (mathematically and numerically) that free available iron decrease is necessary to explain mode one killing which cannot appear without it and that H2O2 quenching or consumption is not responsible for mode-one death. We are able to follow ROS concentration (particularly responsible for mode one killing) after exposure to H2O2. This model therefore allows us to understand two major parameters involved in the presence or not of the first killing mode. PMID:27441232

  18. Effects of mulberry ethanol extracts on hydrogen peroxide-induced oxidative stress in pancreatic β-cells.

    PubMed

    Kim, Young Rae; Lee, Jong Seok; Lee, Ki Rim; Kim, Young Eon; Baek, Nam In; Hong, Eock Kee

    2014-01-01

    Reactive oxygen species (ROS) are key mediators of mammalian cellular damage and are associated with diseases such as aging, arteriosclerosis, inflammation, rheumatoid arthritis and diabetes. Type 1 diabetes develops upon the destruction of pancreatic β-cells, which is partly due to ROS activity. In this study, we investigated the cytoprotective and anti-oxidative effects of fractionated mulberry extracts in mouse insulin-producing pancreatic β-cells (MIN6N cells). Treatment with hydrogen peroxide (H2O2) induced significant cell death and increased intracellular ROS levels, lipid peroxidation and DNA fragmentation in the MIN6N cells. Fractionated mulberry extracts significantly reduced the H2O2-dependent production of intracellular ROS, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals and lipid peroxidation. In addition, mulberry extracts inhibited DNA fragmentation induced by H2O2. Thus, the antioxidant properties of mulberry extracts in pancreatic β-cells may be exploited for the prevention or treatment of type 1 diabetes. PMID:24154764

  19. Green tea constituents (-)-epigallocatechin-3-gallate (EGCG) and gallic acid induce topoisomerase I- and topoisomerase II-DNA complexes in cells mediated by pyrogallol-induced hydrogen peroxide.

    PubMed

    López-Lázaro, Miguel; Calderón-Montaño, José Manuel; Burgos-Morón, Estefanía; Austin, Caroline A

    2011-07-01

    Green tea and its major active constituent, (-)-epigallocatechin-3-gallate (EGCG), are in clinical trials for the prevention and treatment of several diseases such as cancer. DNA topoisomerase (topo) poisons are commonly prescribed anticancer drugs that kill cancer cells by inducing topo-DNA complexes. Using purified topoisomerases, previous in vitro studies have shown that EGCG induces the formation of topo-DNA complexes. Because the activity of a drug on purified topoisomerases does not always represent the activity in a cell, we have used an immunofluorescence technique that allows the visualisation of topo I- and topo II-DNA complexes produced in individual cells to evaluate the activity of EGCG on both enzymes. High levels of topo I- and topo II-DNA complexes were observed in K562 leukaemia cells exposed to EGCG. Similar levels of topo I- and topo II-DNA complexes were visualised in cells treated with gallic acid (GA) (the acid part of the EGCG ester). Pyrogallol (PG) also induced topo-DNA complexes with both enzymes, therefore suggesting that the activity of EGCG and GA is mediated by their PG moieties. Catalase prevented both the cytotoxicity and the formation of topo I- and topo II-DNA complexes induced by EGCG, GA, PG and myricetin (a PG-containing flavonoid recently shown to induce topo I- and topo II-DNA complexes in cells), indicating that hydrogen peroxide mediates these activities. Hydrogen peroxide induced topo I- and topo II (α and β)-DNA complexes in a time- and dose-dependent manner. The formation of topo I- and topo II-DNA complexes in cells exposed to hydrogen peroxide correlated well with the induction of apoptosis, suggesting that the topo-DNA complexes induced at long exposure times by the compounds tested in our study may be apoptotic topo-DNA complexes. Finally, we report results suggesting that PG-containing drugs may selectively kill tumour cells by generating hydrogen peroxide.

  20. Improved Electrolytic Hydrogen Peroxide Generator

    NASA Technical Reports Server (NTRS)

    James, Patrick I.

    2005-01-01

    An improved apparatus for the electrolytic generation of hydrogen peroxide dissolved in water has been developed. The apparatus is a prototype of H2O2 generators for the safe and effective sterilization of water, sterilization of equipment in contact with water, and other applications in which there is need for hydrogen peroxide at low concentration as an oxidant. Potential applications for electrolytic H2O2 generators include purification of water for drinking and for use in industrial processes, sanitation for hospitals and biotechnological industries, inhibition and removal of biofouling in heat exchangers, cooling towers, filtration units, and the treatment of wastewater by use of advanced oxidation processes that are promoted by H2O2.

  1. Effects on gastric mucosa induced by dental bleaching – an experimental study with 6% hydrogen peroxide in rats

    PubMed Central

    PAULA, Anabela Baptista; DIAS, Maria Isabel; FERREIRA, Manuel Marques; CARRILHO, Teresa; MARTO, Carlos Miguel; CASALTA, João; CABRITA, António Silvério; CARRILHO, Eunice

    2015-01-01

    The value of aesthetic dentistry has precipitated several developments in the investigation of dental materials related to this field. The free marketing of these products is a problem and it is subject to various interpretations regarding its legality. There are several techniques for tooth whitening, the most used one being the external bleaching. It is the later version of such technique that poses the greatest danger of ingesting the product. The present study analysed the systemic effect of these products when they are swallowed. Objective This experimental study aimed to observe the effects of a tooth whitening product, whose active agent is 6% hydrogen peroxide, on the gastric mucosa of healthy and non-tumour gastric pathology animals. Material and Methods Fifty Wistar-Han rats were used and then distributed into 5 groups, one for control and four test groups in which the bleaching product was administered in animals with and without non-tumour gastric pathology (induced by the administration of 1 sample of 50% ethanol and 5% of drinking water during 6 days) at different times of study by gavage. There was a decrease in body weight in animals of groups handled during the study period, which was most pronounced in IV and VA groups. Changes in spleen weight relative to body weight revealed no statistically significant changes. An analysis of the frequency was performed on the results of macroscopic observation of the gastric mucosa. Results The gastric mucosa revealed lesions in all manipulated groups, being more frequent in groups III and IV. It appears that there is a synergism when using hydrogen peroxide and 50% ethanol in the same group. Conclusion Therefore, it seems that there are some signs of toxicity 3 to 4 days after administration of 6% hydrogen peroxide. The prescription of these therapies must be controlled by the clinician and the risks must be minimized. PMID:26537721

  2. NASA Hydrogen Peroxide Propulsion Perspective

    NASA Technical Reports Server (NTRS)

    Unger, Ronald; Lyles, Garry M. (Technical Monitor)

    2002-01-01

    This presentation is to provide the current status of NASA's efforts in the development of hydrogen peroxide in both mono-propellant and bi-propellant applications, consistent with the Space Launch Initiative goals of pursuing low toxicity and operationally simpler propellants for application in the architectures being considered for the 2nd Generation Reusable Launch Vehicle, also known as the Space Launch Initiative, or SLI.

  3. Catalases Induction in High Virulence Pinewood Nematode Bursaphelenchus xylophilus under Hydrogen Peroxide-Induced Stress

    PubMed Central

    Vicente, Cláudia S. L.; Ikuyo, Yoriko; Shinya, Ryoji; Mota, Manuel; Hasegawa, Koichi

    2015-01-01

    Considered an EPPO A2 quarantine pest, Bursaphelenchus xylophilus is the causal agent of the pine wilt disease and the most devastating plant parasitic nematode attacking coniferous trees in the world. In the early stages of invasion, this nematode has to manage host defence mechanisms, such as strong oxidative stress. Only successful, virulent nematodes are able to tolerate the basal plant defences, and furthermore migrate and proliferate inside of the host tree. In this work, our main objective was to understand to what extent B. xylophilus catalases are involved in their tolerance to oxidative stress and virulence, using as oxidant agent the reactive oxygen species hydrogen peroxide (H2O2). After 24 hours of exposure, high virulence isolates of B. xylophilus could withstand higher H2O2 concentrations in comparison with low virulence B. xylophilus and B. mucronatus, corroborating our observation of Bxy-ctl-1 and Bxy-ctl-2 catalase up-regulation under the same experimental conditions. Both catalases are expressed throughout the nematode intestine. In addition, transgenic strains of Caenorhabditis elegans overexpressing B. xylophilus catalases were constructed and evaluated for survival under similar conditions as previously. Our results suggest that catalases of high virulence B. xylophilus were crucial for nematode survival under prolonged exposure to in vitro oxidative stress, highlighting their adaptive response, which could contribute to their success in host conditions. PMID:25894519

  4. Acetate induced enhancement of photocatalytic hydrogen peroxide production from oxalic acid and dioxygen.

    PubMed

    Yamada, Yusuke; Nomura, Akifumi; Miyahigashi, Takamitsu; Ohkubo, Kei; Fukuzumi, Shunichi

    2013-05-01

    The addition of acetate ion to an O2-saturated mixed solution of acetonitrile and water containing oxalic acid as a reductant and 2-phenyl-4-(1-naphthyl)quinolinium ion (QuPh(+)-NA) as a photocatalyst dramatically enhanced the turnover number of hydrogen peroxide (H2O2) production. In this photocatalytic H2O2 production, a base is required to facilitate deprotonation of oxalic acid forming oxalate dianion, which acts as an actual electron donor, whereas a Brønsted acid is also necessary to protonate O2(•-) for production of H2O2 by disproportionation. The addition of acetate ion to a reaction solution facilitates both the deprotonation of oxalic acid and the protonation of O2(•-) owing to a pH buffer effect. The quantum yield of the photocatalytic H2O2 production under photoirradiation (λ = 334 nm) of an O2-saturated acetonitrile-water mixed solution containing acetate ion, oxalic acid and QuPh(+)-NA was determined to be as high as 0.34, which is more than double the quantum yield obtained by using oxalate salt as an electron donor without acetate ion (0.14). In addition, the turnover number of QuPh(+)-NA reached more than 340. The reaction mechanism and the effect of solvent composition on the photocatalytic H2O2 production were scrutinized by using nanosecond laser flash photolysis.

  5. Hydrogen peroxide induced relaxation in porcine pulmonary arteries in vitro is mediated by EDRF and cyclic GMP

    SciTech Connect

    Zellers, T.; McCormick, J. )

    1991-03-15

    Xanthine and xanthine oxidase induced relaxations in porcine pulmonary arteries in vitro are augmented in the presence of the endothelium and abolished by catalase, implicating hydrogen peroxide as an endothelium-dependent effector. To determine the mechanism whereby H{sub 2}O{sub 2} causes relaxations, isolated rings of fifth order porcine pulmonary artery, with (E{sup +}) and without (E{sup {minus}}) endothelium, were suspended in organ baths filled with buffer, and isometric tension was recorded. Hydrogen peroxide caused concentration-dependent, endothelium-augmented relaxations which were abolished by catalase and hydroquinone and reversed by L-nitroarginine and methylene blue. Prostacyclin (PGI{sub 2}) levels, measured after a two minute exposure to H{sub 2}O{sub 2} in rings with endothelium were comparable to controls. This concentration of PGI{sub 2} does not cause relaxations in these rings. These data suggest that H{sub 2}O{sub 2} stimulates the release of an EDRF, causing relaxations mediated by cyclic GMP, which is independent of prostacyclin.

  6. Hydrogen peroxide is involved in the cold acclimation-induced chilling tolerance of tomato plants.

    PubMed

    Zhou, Jie; Wang, Jian; Shi, Kai; Xia, Xiao Jian; Zhou, Yan Hong; Yu, Jing Quan

    2012-11-01

    Cold acclimation increases plant tolerance to a more-severe chilling and in this process an accumulation of H(2)O(2) in plants is often observed. To examine the role of H(2)O(2) in cold acclimation in plants, the accumulation of H(2)O(2), antioxidant metabolism, the glutathione redox state, gas exchange and chlorophyll fluorescence were analyzed after cold acclimation at 12/10 °C and during the subsequent chilling at 7/4 °C in tomato (Solanum lycopersicum) plants. Cold acclimation modestly elevated the levels of H(2)O(2), the gene expression of respiratory burst oxidase homolog 1 (Rboh1) and NADPH oxidase activity, leading to the up-regulation of the expression and activity of antioxidant enzymes. In non-acclimated plants chilling caused a continuous rise in the H(2)O(2) content, an increase in the malondialdehyde (MDA) content and in the oxidized redox state of glutathione, followed by reductions in the CO(2) assimilation rate and the maximum quantum yield of photosystem II (F(v)/F(m)). However, in cold-acclimated plants chilling-induced photoinhibition, membrane peroxidation and reductions in the CO(2) assimilation rate were significantly alleviated. Furthermore, a treatment with an NADPH oxidase inhibitor or H(2)O(2) scavenger before the plants subjected to the cold acclimation abolished the cold acclimation-induced beneficial effects on photosynthesis and antioxidant metabolism, leading to a loss of the cold acclimation-induced tolerance against chilling. These results strongly suggest that the H(2)O(2) generated by NADPH oxidase in the apoplast of plant cells plays a crucial role in cold acclimation-induced chilling tolerance.

  7. Nitric oxide and hydrogen peroxide in tomato resistance. Nitric oxide modulates hydrogen peroxide level in o-hydroxyethylorutin-induced resistance to Botrytis cinerea in tomato.

    PubMed

    Małolepsza, Urszula; Rózalska, Sylwia

    2005-06-01

    Nitric oxide (NO) has been postulated to be required, together with reactive oxygen species (ROS), for activation of disease resistance reactions of plants to infection with a pathogen or elicitor treatment. However, biochemical mechanisms by which ROS and NO participate in these reactions are still under intensive study and controversial debate. We previously demonstrated that o-hydroxyethylorutin when applied on tomato leaves (Lycopersicon esculentum Mill. cv. "Perkoz") restricted Botrytis cinerea infection development. In this research we investigated ROS and NO generation in tomato plants treated with o-hydroxyethylorutin, non-treated and infected ones. The NO content was enhanced or decreased in the studied plants by supplying them with NO generator-SNP or scavenger-cPTIO. NO detection was carried out using diaminofluorescein diacetate (DAF-DA) in conjunction with confocal laser scanning microscopy. The influence of elevated and decreased levels of NO on B. cinerea infection development and ROS generation was studied. The elevated NO concentration in tomato leaves strongly decreased hydrogen peroxide concentration without affecting other studied ROS (superoxide anion and hydroxyl radical) levels. H2O2 concentrations in NO-supplied leaves were low regardless of further treatment of tomato leaves with o-hydroxyethylorutin or inoculation with B. cinerea. The low H2O2 concentration coincided with quick and severe infection development in NO-supplied leaves. As activities of enzymes generating (SOD EC 1.15.1.1)) and removing (APX EC 1.11.1.11, CAT EC 1.11.1.6) H2O2 were unchanged in the studied plants, the decrease in H2O2 concentration was probably due to a direct NO-H2O2 interaction. PMID:15922611

  8. Combination Treatment of Hydrogen Peroxide and X-Rays Induces Apoptosis in Human Prostate Cancer PC-3 Cells

    SciTech Connect

    Kariya, Shinji Sawada, Ken; Kobayashi, Toshihiro; Karashima, Takashi; Shuin, Taro; Nishioka, Akihito; Ogawa, Yasuhiro

    2009-10-01

    Purpose: To study the effect of hydrogen peroxide (H{sub 2}O{sub 2}) on radiation-induced apoptosis in human prostate cancer PC-3 cells. Methods and Materials: At 4h before the irradiation, PC-3 cells were exposed to 10mM ammonium chloride (NH{sub 4}Cl) concentrations. Subsequently, cells were exposed to 0.1mM H{sub 2}O{sub 2} just before the irradiations, which were administered with 10-MV X-rays at doses of 10Gy. Results: The percentage of apoptotic cells at 48h after X-irradiation alone, H{sub 2}O{sub 2} alone, and combined X-irradiation and H{sub 2}O{sub 2} was 1.85%, 4.85%, and 28.4%, respectively. With use of combined X-irradiation and H{sub 2}O{sub 2}, production of reactive oxygen species (ROS) occurred 4h after the irradiation. This resulted in lysosomal rupturing, mitochondrial fragmentation, and the release of cytochrome c into the cytoplasm from the mitochondria. In contrast, when cells were exposed to NH{sub 4}Cl before the X-irradiation and H{sub 2}O{sub 2} administration, apoptosis was almost completely suppressed, ROS production did not occur, lysosomal rupture and mitochondrial fragmentation were blocked, and cytochrome c was not released. Conclusions: Hydrogen peroxide strongly enhanced lysosome-dependent radiation-induced apoptosis in human prostate cancer PC-3 cells. A combined use of X-rays and H{sub 2}O{sub 2} can also injure the mitochondrial cytoplasmic organelles and lead to the production of ROS that in and of itself might possibly induce apoptosis.

  9. Hydrogen peroxide: A central player in physical plasma-induced oxidative stress in human blood cells.

    PubMed

    Bekeschus, S; Kolata, J; Winterbourn, C; Kramer, A; Turner, R; Weltmann, K D; Bröker, B; Masur, K

    2014-05-01

    Plasma medicine is an interdisciplinary field and recent clinical studies showed benefits of topical plasma application to chronic wounds. Whereas most investigations have focused on plasma-skin cell interaction, immune cells are omnipresent in most tissues as well. They not only elicit specific immune responses but also regulate inflammation, which is central in healing and regeneration. Plasma generates short-lived radicals and species in the gas phase. Mechanisms of plasma-cell interactions are not fully understood but it is hypothesized that reactive oxygen and nitrogen species (RONS) mediate effects of plasma on cells. In this study human blood cells were investigated after cold atmospheric plasma treatment with regard to oxidation and viability. Plasma generates hydrogen peroxide (H2O2) and the responses were similar in cells treated with concentration-matched H2O2. Both treatments gave an equivalent reduction in viability and this was completely abrogated if catalase was added prior to plasma exposure. Further, five oxidation probes were utilized and fluorescence increase was observed in plasma-treated cells. Dye-dependent addition of catalase diminished most but not all of the probe fluorescence, assigning H2O2 a dominant but not exclusive role in cellular oxidation by plasma. Investigations for other species revealed generation of nitrite and formation of 3-nitrotyrosine but not 3-chlorotyrosine after plasma treatment indicating presence of RNS which may contribute to cellular redox changes observed. Together, these results will help to clarify how oxidative stress associates with physical plasma treatment in wound relevant cells. PMID:24528134

  10. NADPH oxidase-generated hydrogen peroxide induces DNA damage in mutant FLT3-expressing leukemia cells.

    PubMed

    Stanicka, Joanna; Russell, Eileen G; Woolley, John F; Cotter, Thomas G

    2015-04-10

    Internal tandem duplication of the FMS-like tyrosine kinase (FLT3-ITD) receptor is present in 20% of acute myeloid leukemia (AML) patients and it has been associated with an aggressive AML phenotype. FLT3-ITD expressing cell lines have been shown to generate increased levels of reactive oxygen species (ROS) and DNA double strand breaks (DSBs). However, the molecular basis of how FLT3-ITD-driven ROS leads to the aggressive form of AML is not clearly understood. Our group has previously reported that inhibition of FLT3-ITD signaling results in post-translational down-regulation of p22(phox), a small membrane-bound subunit of the NADPH oxidase (NOX) complex. Here we demonstrated that 32D cells, a myeloblast-like cell line transfected with FLT3-ITD, have a higher protein level of p22(phox) and p22(phox)-interacting NOX isoforms than 32D cells transfected with the wild type FLT3 receptor (FLT3-WT). The inhibition of NOX proteins, p22(phox), and NOX protein knockdowns caused a reduction in ROS, as measured with a hydrogen peroxide (H2O2)-specific dye, peroxy orange 1 (PO1), and nuclear H2O2, as measured with nuclear peroxy emerald 1 (NucPE1). These reductions in the level of H2O2 following the NOX knockdowns were accompanied by a decrease in the number of DNA DSBs. We showed that 32D cells that express FLT3-ITD have a higher level of both oxidized DNA and DNA DSBs than their wild type counterparts. We also observed that NOX4 and p22(phox) localize to the nuclear membrane in MV4-11 cells expressing FLT3-ITD. Taken together these data indicate that NOX and p22(phox) mediate the ROS production from FLT3-ITD that signal to the nucleus causing genomic instability. PMID:25697362

  11. Modulatory effects of Moringa oleifera extracts against hydrogen peroxide-induced cytotoxicity and oxidative damage.

    PubMed

    Sreelatha, S; Padma, P R

    2011-09-01

    Studies have demonstrated that the induction of oxidative stress may be involved in oxidative DNA damage. The present study examined and assessed the hydrogen peroxide (H(2)O(2))-mediated DNA damage in human tumor KB cells and also assessed the ability of Moringa oleifera leaf extracts to inhibit the oxidative damage. H(2)O(2) imposed a stress on the membrane lipids which was quantified by the extent of thiobarbituric acid reactive substances (TBARS) formed. The leaf extracts caused a very significant inhibition of the extent of LPO formation and enhanced the activity of antioxidative enzymes such as superoxide dismutase (SOD) and catalase (CAT) in KB cells. The comet assay was employed to study the DNA damage and its inhibition by the leaf extracts. H(2)O(2) caused a significant increase in the number of cells bearing comets, resulting in significant DNA damage. The leaf extracts significantly reduced the incidence of comets in the oxidant stressed cells. The extent of cytotoxicity of H(2)O(2) in the presence and the absence of leaf extracts studied in KB tumor cells by the MTT assay showed that H(2)O(2) caused a marked decrease in the viability of KB cells where as the leaf extracts effectively increased the viability of assaulted KB cells. The observed cytoprotective activity is probably due to the antioxidant properties of its constituents, mainly phenolics. Total phenolics showed higher correlation with antioxidant activity. The leaf extracts showed higher antioxidant activity than the reference compound. These results suggest that the inhibition by the leaf extracts on oxidative DNA damage could be attributed to their free radical scavenging activities and the effect evidenced in KB cells can be in part correlated to a modulation of redox-sensitive mechanisms.

  12. Mechanism of hydrogen peroxide-induced inhibition of sheep airway cilia.

    PubMed

    Kobayashi, K; Salathé, M; Pratt, M M; Cartagena, N J; Soloni, F; Seybold, Z V; Wanner, A

    1992-06-01

    To study the effect of the inflammatory mediator hydrogen peroxide (H2O2) on airway ciliary activity, we measured ciliary beat frequency (CBF) in cultured tracheal explants from sheep. Addition of H2O2 (10(-8) to 10(-4) M) produced a concentration-dependent mean (+/- SEM) decrease in CBF between 11.1 +/- 0.4% (P less than 0.01) and 100 +/- 0% (P less than 0.001); at each concentration, the maximal effect was reached by 20 to 25 min. Between 10(-8) and 10(-6) M H2O2, the decrease in CBF was reversible, lactate dehydrogenase (LDH) release was not significantly increased, and major morphologic lesions were not seen. At higher concentrations of H2O2, incomplete recovery of CBF (10(-5) M) or irreversible ciliostasis (10(-4) M) developed, and a significant increase in LDH and morphologic lesions were present. Catalase (2,000 U/ml) and H-7 (10(-5) M), a protein kinase inhibitor, abolished cilioinhibition produced by H2O2 at 10(-6) M and lower concentrations but not at 10(-5) M and higher concentrations. Phorbol 12-myristate 13-acetate (PMA), a protein kinase C activator, caused a dose-dependent (10(-11) to 10(-5) M), reversible decrease in CBF; this effect was abolished by H-7. We suggest that at nonlethal concentrations, H2O2 inhibits the beat frequency of airway epithelial cilia reversibly, through the activation of second messengers, including protein kinase C. This mechanism might contribute to the previously demonstrated impairment of mucociliary clearance in airway inflammation.

  13. Coating for components requiring hydrogen peroxide compatibility

    NASA Technical Reports Server (NTRS)

    Yousefiani, Ali (Inventor)

    2010-01-01

    The present invention provides a heretofore-unknown use for zirconium nitride as a hydrogen peroxide compatible protective coating that was discovered to be useful to protect components that catalyze the decomposition of hydrogen peroxide or corrode when exposed to hydrogen peroxide. A zirconium nitride coating of the invention may be applied to a variety of substrates (e.g., metals) using art-recognized techniques, such as plasma vapor deposition. The present invention further provides components and articles of manufacture having hydrogen peroxide compatibility, particularly components for use in aerospace and industrial manufacturing applications. The zirconium nitride barrier coating of the invention provides protection from corrosion by reaction with hydrogen peroxide, as well as prevention of hydrogen peroxide decomposition.

  14. Catalase plays a key role in salt stress acclimation induced by hydrogen peroxide pretreatment in maize.

    PubMed

    Gondim, Franklin Aragão; Gomes-Filho, Enéas; Costa, José Hélio; Mendes Alencar, Nara Lídia; Prisco, José Tarquinio

    2012-07-01

    Pretreatment in plants is recognized as a valuable strategy to stimulate plant defenses, leading to better plant development. This study evaluated the effects of H₂O₂ leaf spraying pretreatment on plant growth and investigated the antioxidative mechanisms involved in the response of maize plants to salt stress. It was found that salinity reduced maize seedling growth when compared to control conditions, and H₂O₂ foliar spraying was effective in minimizing this effect. Analysis of the antioxidative enzymes catalase (EC 1.11.1.6), guaiacol peroxidase (EC 1.11.1.7), ascorbate peroxidase (EC 1.11.1.1) and superoxide dismutase (EC 1.15.1.1) revealed that H₂O₂ spraying increased antioxidant enzyme activities. Catalase (CAT) was the most responsive of these enzymes to H₂O₂, with higher activity early (48 h) in the treatment, while guaiacol peroxidase (GPX) and ascorbate peroxidase (APX) were responsive only at later stages (240 h) of treatment. Increased CAT activity appears linked to gene expression regulation. Lower malondialdehyde levels were detected in plants with higher CAT activity, which may result from the protective function of this enzyme. Overall, we can conclude that pretreatment with H₂O₂ leaf spraying was able to reduce the deleterious effects of salinity on seedling growth and lipid peroxidation. These responses could be attributed to the ability of H₂O₂ to induce antioxidant defenses, especially CAT activity.

  15. The role of insulin against hydrogen peroxide-induced oxidative damages in differentiated SH-SY5Y cells.

    PubMed

    Ramalingam, Mahesh; Kim, Sung-Jin

    2014-06-01

    Exogenous hydrogen peroxide (H2O2) can easily penetrate into biological membranes and enhance the formation of other reactive oxygen species (ROS). In the present study, we have investigated the neuroprotective effects of insulin on H2O2-induced toxicity of retinoic acid (RA)-differentiated SH-SY5Y cells. To measure the changes in the cell viability of SH-SY5Y cells at different concentrations of H2O2 for 24 h, a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT)-based assay was used and a 100 µM H2O2 was selected to establish a model of H2O2-induced oxidative stress. Further assays showed that 24 h of 100 µM H2O2-induced significant changes in the levels of lactate dehydrogenase (LDH), nitric oxide (NO), ROS, and calcium ion (Ca2+) in neuronal cells, but insulin can effectively diminish the H2O2-induced oxidative damages to these cells. Moreover, cells treated with insulin increased H2O2-induced suppression of glutathione levels and exerted an apparent suppressive effect on oxidative products. The results of insulin treatment with SH-SY5Y cells increased the Bcl-2 levels and decreased the Akt levels. The treatment of insulin had played a protective effect on H2O2-induced oxidative stress related to the Akt/Bcl-2 pathways.

  16. Hydrogen peroxide on the surface of Europa.

    PubMed

    Carlson, R W; Anderson, M S; Johnson, R E; Smythe, W D; Hendrix, A R; Barth, C A; Soderblom, L A; Hansen, G B; McCord, T B; Dalton, J B; Clark, R N; Shirley, J H; Ocampo, A C; Matson, D L

    1999-03-26

    Spatially resolved infrared and ultraviolet wavelength spectra of Europa's leading, anti-jovian quadrant observed from the Galileo spacecraft show absorption features resulting from hydrogen peroxide. Comparisons with laboratory measurements indicate surface hydrogen peroxide concentrations of about 0.13 percent, by number, relative to water ice. The inferred abundance is consistent with radiolytic production of hydrogen peroxide by intense energetic particle bombardment and demonstrates that Europa's surface chemistry is dominated by radiolysis. PMID:10092224

  17. High Temperature Decomposition of Hydrogen Peroxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2004-01-01

    Nitric oxide (NO) is oxidized into nitrogen dioxide (NO2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydropemxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

  18. High temperature decomposition of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2005-01-01

    Nitric oxide (NO) is oxidized into nitrogen dioxide (NO2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydroperoxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

  19. Hydrogen peroxide on the surface of Europa

    NASA Technical Reports Server (NTRS)

    Carlson, R. W.; Anderson, M. S.; Johnson, R. E.; Smythe, W. D.; Hendrix, A. R.; Barth, C. A.; Soderblom, L. A.; Hansen, G. B.; McCord, T. B.; Dalton, J. B.; Clark, R. N.; Shirley, J. H.; Ocampo, A. C.; Matson, D. L.

    1999-01-01

    Spatially resolved infrared and ultraviolet wavelength spectra of Europa's leading, anti-jovian quadrant observed from the Galileo spacecraft show absorption features resulting from hydrogen peroxide. Comparisons with laboratory measurements indicate surface hydrogen peroxide concentrations of about 0.13 percent, by number, relative to water ice. The inferred abundance is consistent with radiolytic production of hydrogen peroxide by intense energetic particle bombardment and demonstrates that Europa's surface chemistry is dominated by radiolysis.

  20. Hydrogen peroxide, from Wieland to Sies.

    PubMed

    Koppenol, Willem H

    2016-04-01

    A history of the formation of hydrogen peroxide in vivo is presented, starting with the discovery of catalase. The first hypothesis was formulated by Heinrich Wieland, who assumed that dioxygen reacted directly with organic molecules. This view was strongly criticised by Otto Warburg, Helmut Sies' academic grandfather. The involvement of hydrogen peroxide in physiological processes was investigated by Theodor Bücher, the "Doktorvater" of Helmut. Helmut's research made it possible to quantitate hydrogen peroxide in tissues.

  1. Hydrogen peroxide is a true first messenger.

    PubMed

    Holmquist, L; Stuchbury, G; Steele, M; Münch, G

    2007-01-01

    Hydrogen peroxide has been shown to act as a second messenger mediating intracellular redox-sensitive signal transduction. Here we show that hydrogen peroxide is also able to transmit pro-inflammatory signals from one cell to the other and that this action can be inhibited by extracellularly added catalase. If these data can be further substantiated, hydrogen peroxide might become as important as nitric oxide as a small molecule intercellular (first) messenger.

  2. Hydrogen peroxide mechanosynthesis in siloxane-hydrogel contact lenses.

    PubMed

    Tavazzi, Silvia; Ferraro, Lorenzo; Cozza, Federica; Pastori, Valentina; Lecchi, Marzia; Farris, Stefano; Borghesi, Alessandro

    2014-11-26

    Drug-loaded contact lenses are emerging as the preferred treatment method for several ocular diseases, and efforts are being directed to promote extended and controlled delivery. One strategy is based on delivery induced by environmental triggers. One of these triggers can be hydrogen peroxide, since many platforms based on drug-loaded nanoparticles were demonstrated to be hydrogen-peroxide responsive. This is particularly interesting when hydrogen peroxide is the result of a specific pathophysiological condition. Otherwise, an alternative route to induce drug delivery is here proposed, namely the mechano-synthesis. The present work represents the proof-of-concept of the mechanosynthesis of hydrogen peroxide in siloxane-hydrogel contact lenses as a consequence of the cleavage of siloxane bonds at the interface between the polymer and water in aqueous phase. Their spongy morphology makes contact lenses promising systems for mechanical-to-chemical energy conversion, since the amount of hydrogen peroxide is expected to scale with the interfacial area between the polymer and water. The eyelid pressure during wear is sufficient to induce the hydrogen peroxide synthesis with concentrations which are biocompatible and suitable to trigger the drug release through hydrogen-peroxide-responsive platforms. For possible delivery on demand, the integration of piezoelectric polymers in the siloxane-hydrogel contact lenses could be designed, whose mechanical deformation could be induced by an applied wireless-controlled voltage.

  3. Oxidative cleavage of cycloalkanones by hydrogen peroxide

    SciTech Connect

    Starostin, E.K.; Aleksandrov, A.V.; Nikishin, G.I.

    1986-07-10

    The authors have studied the reaction of cyclopentanone, cyclohexanone, cycloheptanone, and cyclododecanone with aqueous hydrogen peroxide over the temperature range 110-150/sup 0/C. The effects of temperature, hydrogen peroxide concentration, and the molar proportions of the reagents on the composition and yields of the products have been examined in the case of cyclohexanone. Oxidation of cyclohexanone by aqueous hydrogen peroxide at 110-150/sup 0/C gives 1,10-decanedicarboxylic acid and hexanoic acid as the principal products. Cyclopentanone and cycloheptanone react with hydrogen peroxide similarly to cyclohexanone, giving sebacic and pentanoic acids, and 1,12-dodecanedicarboxylic acids, respectively.

  4. Protective effect of reduced glutathione C60 derivative against hydrogen peroxide-induced apoptosis in HEK 293T cells.

    PubMed

    Huang, Jin; Zhou, Chi; He, Jun; Hu, Zheng; Guan, Wen-Chao; Liu, Sheng-Hong

    2016-06-01

    Hydrogen peroxide (H2O2) and free radicals cause oxidative stress, which induces cellular injuries, metabolic dysfunction, and even cell death in various clinical abnormalities. Fullerene (C60) is critical for scavenging oxygen free radicals originated from cell metabolism, and reduced glutathione (GSH) is another important endogenous antioxidant. In this study, a novel water-soluble reduced glutathione fullerene derivative (C60-GSH) was successfully synthesized, and its beneficial roles in protecting against H2O2-induced oxidative stress and apoptosis in cultured HEK 293T cells were investigated. Fourier Transform infrared spectroscopy and (1)H nuclear magnetic resonance were used to confirm the chemical structure of C60-GSH. Our results demonstrated that C60-GSH prevented the reactive oxygen species (ROS)-mediated cell damage. Additionally, C60-GSH pretreatment significantly attenuated H2O2-induced superoxide dismutase (SOD) consumption and malondialdehyde (MDA) elevation. Furthermore, C60-GSH inhibited intracellular calcium mobilization, and subsequent cell apoptosis via bcl-2/bax-caspase-3 signaling pathway induced by H2O2 stimulation in HEK 293T cells. Importantly, these protective effects of C60-GSH were superior to those of GSH. In conclusion, these results suggested that C60-GSH has potential to protect against H2O2-induced cell apoptosis by scavenging free radicals and maintaining intracellular calcium homeostasis without evident toxicity.

  5. N-Acetyl-Serotonin Protects HepG2 Cells from Oxidative Stress Injury Induced by Hydrogen Peroxide

    PubMed Central

    Jiang, Jiying; Yu, Shuna; Jiang, Zhengchen; Liang, Cuihong; Yu, Wenbo; Li, Jin; Du, Xiaodong; Wang, Hailiang; Gao, Xianghong; Wang, Xin

    2014-01-01

    Oxidative stress plays an important role in the pathogenesis of liver diseases. N-Acetyl-serotonin (NAS) has been reported to protect against oxidative damage, though the mechanisms by which NAS protects hepatocytes from oxidative stress remain unknown. To determine whether pretreatment with NAS could reduce hydrogen peroxide- (H2O2-) induced oxidative stress in HepG2 cells by inhibiting the mitochondrial apoptosis pathway, we investigated the H2O2-induced oxidative damage to HepG2 cells with or without NAS using MTT, Hoechst 33342, rhodamine 123, Terminal dUTP Nick End Labeling Assay (TUNEL), dihydrodichlorofluorescein (H2DCF), Annexin V and propidium iodide (PI) double staining, immunocytochemistry, and western blot. H2O2 produced dramatic injuries in HepG2 cells, represented by classical morphological changes of apoptosis, increased levels of malondialdehyde (MDA) and intracellular reactive oxygen species (ROS), decreased activity of superoxide dismutase (SOD), and increased activities of caspase-9 and caspase-3, release of cytochrome c (Cyt-C) and apoptosis-inducing factor (AIF) from mitochondria, and loss of membrane potential (ΔΨm). NAS significantly inhibited H2O2-induced changes, indicating that it protected against H2O2-induced oxidative damage by reducing MDA levels and increasing SOD activity and that it protected the HepG2 cells from apoptosis through regulating the mitochondrial apoptosis pathway, involving inhibition of mitochondrial hyperpolarization, release of mitochondrial apoptogenic factors, and caspase activity. PMID:25013541

  6. Protective effect of reduced glutathione C60 derivative against hydrogen peroxide-induced apoptosis in HEK 293T cells.

    PubMed

    Huang, Jin; Zhou, Chi; He, Jun; Hu, Zheng; Guan, Wen-Chao; Liu, Sheng-Hong

    2016-06-01

    Hydrogen peroxide (H2O2) and free radicals cause oxidative stress, which induces cellular injuries, metabolic dysfunction, and even cell death in various clinical abnormalities. Fullerene (C60) is critical for scavenging oxygen free radicals originated from cell metabolism, and reduced glutathione (GSH) is another important endogenous antioxidant. In this study, a novel water-soluble reduced glutathione fullerene derivative (C60-GSH) was successfully synthesized, and its beneficial roles in protecting against H2O2-induced oxidative stress and apoptosis in cultured HEK 293T cells were investigated. Fourier Transform infrared spectroscopy and (1)H nuclear magnetic resonance were used to confirm the chemical structure of C60-GSH. Our results demonstrated that C60-GSH prevented the reactive oxygen species (ROS)-mediated cell damage. Additionally, C60-GSH pretreatment significantly attenuated H2O2-induced superoxide dismutase (SOD) consumption and malondialdehyde (MDA) elevation. Furthermore, C60-GSH inhibited intracellular calcium mobilization, and subsequent cell apoptosis via bcl-2/bax-caspase-3 signaling pathway induced by H2O2 stimulation in HEK 293T cells. Importantly, these protective effects of C60-GSH were superior to those of GSH. In conclusion, these results suggested that C60-GSH has potential to protect against H2O2-induced cell apoptosis by scavenging free radicals and maintaining intracellular calcium homeostasis without evident toxicity. PMID:27376803

  7. Neuroprotective activity of Viola mandshurica extracts on hydrogen peroxide-induced DNA damage and cell death in PC12 cells.

    PubMed

    Jeon, Gyeong-Im; Yoon, Mi-Young; Park, Hae-Ryoung; Lee, Seung-Cheol; Park, Eunju

    2009-08-01

    This study was conducted to examine the neuroprotective effects of acetone extracts from Viola mandshurica (VME). The effect of VME on hydrogen peroxide (H(2)O(2))-induced DNA damage in PC12 cells was evaluated by the comet assay where VME (100 and 250 microg/mL) was a dose-dependent inhibitor of DNA damage induced by 500 micromol/L of H(2)O(2). The protective effect of VME against H(2)O(2)-induced oxidative damage on PC12 cells was investigated by an MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] reduction assay and lactate dehydrogenase (LDH) release assays. After 3 h of cell exposure to 500 micromol/L of H(2)O(2), a marked reduction in cell survival was observed. However, the reduction was significantly prevented by 100 and 250 microg/mL of VME. H(2)O(2) also induced severe apoptosis of the PC12 cells, which was indicated by Hoechst 33342 staining. Interestingly, the H(2)O(2)-stressed PC12 cells that were incubated with 100 and 250 microg/mL of VME had greatly suppressed apoptosis. The results suggest that VME could be a new antioxidant candidate against neuronal diseases.

  8. Inhibition of sphingomyelin synthase 1 affects ceramide accumulation and hydrogen peroxide-induced apoptosis in Neuro-2a cells.

    PubMed

    Tu, Ranran; Yang, Wei; Hu, Zhiping

    2016-09-01

    Oxidative stress plays a key role in brain injury after cerebral ischemia-reperfusion, which contributes toward excessive apoptosis of nerve cells. Therefore, it would be beneficial to identify a therapy that could interfere with the progression of apoptosis and protect the brain from ischemia-reperfusion injury. As ceramide, a well-known second messenger of apoptosis, can be metabolized by sphingomyelin synthase 1 (SMS1), recent research has focused on the link between SMS1 and apoptosis in different cells. To investigate whether SMS1 is involved in the process of oxidative stress-induced apoptosis in neurons and to explore the possible underlying mechanism, we treated mouse neuroblastoma Neuro-2A (N2a) cells with hydrogen peroxide (H2O2). Incubation with H2O2 significantly upregulated the expression of SMS1, increased the intracellular levels of ceramide and sphingomyelin synthase activity, and induced apoptosis. Moreover, pretreatment of N2a cells with D609, an sphingomyelin synthase inhibitor, or SMS1-silencing RNA (siRNA) further increased ceramide and potentiated H2O2-induced apoptosis which could be reversed by SB203580 (a p38 inhibitor). Thus, our study has shown that SMS1 regulates ceramide levels in N2a cells and plays a potent protective role in this oxidative stress-induced apoptosis partly through the p38 pathway.

  9. Potassium 2-(1-hydroxypentyl)-benzoate attenuated hydrogen peroxide-induced apoptosis in neuroblastoma SK-N-SH cells.

    PubMed

    Hu, Yanli; Peng, Ying; Long, Yan; Xu, Shaofeng; Feng, Nan; Wang, Ling; Wang, Xiaoliang

    2012-04-01

    Potassium 2-(1-hydroxypentyl)-benzoate (dl-PHPB) has been shown to have potent neuroprotective effects, such as reducing the infarct volume and improving neurobehavioral deficits in the transient focal cerebral ischemic rat model. The present study is to evaluate the neuroprotective effect of dl-PHPB on hydrogen peroxide (H(2)O(2))-induced apoptosis and the possible mechanism in the human neuroblastoma SK-N-SH cells. Our results showed that dl-PHPB significantly attenuated H(2)O(2)-induced cell death, and reduced neuronal apoptosis. Dl-PHPB partially reversed the decrease of B-cell CLL/lymphoma 2 (Bcl-2) protein level induced by H(2)O(2). Furthermore, dl-PHPB inhibited the elevation of pro-apoptotic Bcl-2-associated X protein (Bax) and caspase3, and alleviated the down-regulation of protein kinase C alpha (PKCα). The PKC inhibitor, Calphostin C significantly attenuated the protective effects of dl-PHPB. The findings suggest that dl-PHPB may protect neurons against H(2)O(2)-induced apoptosis by modulating apoptosis-related proteins, and PKC signaling pathway may be involved in the neuroprotection of dl-PHPB.

  10. Protective effect of cholesterol-loaded cyclodextrin pretreatment against hydrogen peroxide induced oxidative damage in ram sperm.

    PubMed

    Naseer, Zahid; Ahmad, Ejaz; Aksoy, Melih; Küçük, Niyazi; Serin, İlker; Ceylan, Ahmet; Boyacıoğlu, Murat; Kum, Cavit

    2015-08-01

    Three experiments were conducted to determine the protective effect of cholesterol-loaded cyclodextrin (CLC) against hydrogen peroxide (H2O2) or cryo-induced damage in ram sperm. In Experiment 1, the fresh ejaculates were either treated with CLC or remained untreated. Both CLC treated and untreated samples were then incubated with 0, 250 or 500 μM H2O2 at 35°C for 12 h. After incubation period of 12 h, the motility, viability and membrane integrity remained higher in CLC treated sperm even in the presence of 250 or 500 μM H2O2. The H2O2 treatment affected all the sperm parameters adversely (P<0.05). However, compared to CLC untreated counterpart, the motility, viability and membrane integrity remained higher (P<0.05) in treated sperm, even in the presence of 250 or 500 μM H2O2 during 12 h of incubation. In Experiment 2, semen was cryopreserved in the presence or absence of CLC. The post-thaw results revealed that CLC treated sperm has higher (P<0.05) motility, viability and membrane integrity compared to the control. In Experiment 3, lipid peroxidation levels were assessed by determining malondialdehyde (MDA) concentrations during the H2O2-induced oxidative stress in CLC treated and untreated sperm. However, no difference (P>0.05) in MDA level was observed among the groups at any stage of incubation. In conclusion, the CLC incorporation in ram sperm membrane may protects it against H2O2 or cryo-induced oxidative damage. The cryoprotective influence of CLC on ram sperm might be resulted from, at least partly, its antioxidative property.

  11. Cytoprotective propensity of Bacopa monniera against hydrogen peroxide induced oxidative damage in neuronal and lung epithelial cells.

    PubMed

    Pandareesh, M D; Anand, T; Bhat, Pratiksha V

    2016-01-01

    Hydrogen peroxide (H2O2), a major reactive oxygen species (ROS) produced during oxidative stress, is toxic to the cells. Hence, H2O2 has been extensively used to study the effects of antioxidant and cytoprotective role of phytochemicals. In the present investigation H2O2 was used to induce oxidative stress via ROS production within PC12 and L132 cells. Cytoprotective propensity of Bacopa monniera extract (BME) was confirmed by cell viability assays, ROS estimation, lipid peroxidation, mitochondria membrane potential assay, comet assay followed by gene expression studies of antioxidant enzymes in PC12 and L132 cells treated with H2O2 for 24 h with or without BME pre-treatment. Our results elucidate that BME possesses radical scavenging activity by scavenging 2,2-diphenyl-1-picrylhydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid), superoxide radical, and nitric oxide radicals. The IC50 value of BME against these radicals was found to be 226.19, 15.17, 30.07, and 34.55 µg/ml, respectively). The IC50 of BME against ROS, lipid peroxidation and protein carbonylation was found to be 1296.53, 753.22, and 589.04 µg/ml in brain and 1137.08, 1079.65, and 11101.25 µg/ml in lung tissues, respectively. Further cytoprotective potency of the BME ameliorated the mitochondrial and plasma membrane damage induced by H2O2 as evidenced by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase leakage assays in both PC12 and L132 cells. H2O2 induced cellular, nuclear and mitochondrial membrane damage was restored by BME pre-treatment. H2O2 induced depleted antioxidant status was also replenished by BME pre-treatment. This was confirmed by spectrophotometric analysis, semi-quantitative RT-PCR and western blot studies. These results justify the traditional usage of BME based on its promising antioxidant and cytoprotective property.

  12. Neuroprotective effect of Citrus unshiu immature peel and nobiletin inhibiting hydrogen peroxide-induced oxidative stress in HT22 murine hippocampal neuronal cells

    PubMed Central

    Cho, Hyun Woo; Jung, Su Young; Lee, Gyeong Hwan; Cho, Jung Hee; Choi, In Young

    2015-01-01

    Background: Oxidative stress-induced cell damage is common in the etiology of several neurobiological disorders, including Alzheimer's disease and Parkinson's disease. In a case study, nobiletin-rich Citrus reticulata peels could prevent the progression of cognitive impairment in donepezil-preadministered Alzheimer's disease patients. Objective: In this study, we investigated the effects and underlying mechanism of nobiletin and Citrus unshiu immature peel (CUIP) water extract, which contains nobiletin as a major compound, on hydrogen peroxide-induced oxidative stress in HT22 cells, a murine hippocampal neuronal model. Materials and Methods: HT22 cells were treated with hydrogen peroxide in the presence or absence of various concentrations of CUIP and nobiletin. Cytotoxicity and apoptotic protein levels were measured by 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and Western blotting. Results: Pretreatment with CUIP and nobiletin inhibited cell death due to hydrogen peroxide. Hydrogen peroxide-induced the expression of phospho-Jun N-terminal kinases (p-JNK) and p-p38 proteins in HT22 cells; however CUIP and nobiletin suppressed p-JNK and p-p38 without changing JNK or p38. Regarding apoptosis, caspase 3, B-cell lymphoma 2 (Bcl-2), and Bax protein expression was determined. CUIP and nobiletin suppressed caspase 3 and Bax expression, but they induced Bcl-2 expression in HT22 cells. Conclusion: These results show that CUIP and nobiletin can protect against hydrogen peroxide-induced cell death in HT22 neurons via mitogen-activated protein kinases and apoptotic pathways. PMID:26664016

  13. Protective Effect of Total Phenolic Compounds from Inula helenium on Hydrogen Peroxide-induced Oxidative Stress in SH-SY5Y Cells

    PubMed Central

    Wang, J.; Zhao, Y. M.; Zhang, B.; Guo, C. Y.

    2015-01-01

    Inula helenium has been reported to contain a large amount of phenolic compounds, which have shown promise in scavenging free radicals and prevention of neurodegenerative diseases. This study is to investigate the neuroprotective effects of total phenolic compounds from I. helenium on hydrogen peroxide-induced oxidative damage in human SH-SY5Y cells. Antioxidant capacity of total phenolic compounds was determined by radical scavenging activity, the level of intracellular reactive oxygen species and superoxide dismutase activity. The cytotoxicity of total phenolic compounds was determined using a cell counting kit-8 assay. The effect of total phenolic compounds on cell apoptosis due to hydrogen peroxide-induced oxidative damage was detected by Hoechst 33258 and Annexin-V/PI staining using fluorescence microscope and flow cytometry, respectively. Mitochondrial function was evaluated using the mitochondrial membrane potential and mitochondrial ATP synthesis by JC-1 dye and high performance liquid chromatography, respectively. It was shown that hydrogen peroxide significantly induced the loss of cell viability, increment of apoptosis, formation of reactive oxygen species, reduction of superoxide dismutase activity, decrease in mitochondrial membrane potential and a decrease in adenosine triphosphate production. On the other hand, total phenolic compounds dose-dependently reversed these effects. This study suggests that total phenolic compounds exert neuroprotective effects against hydrogen peroxide-induced oxidative damage via blocking reactive oxygen species production and improving mitochondrial function. The potential of total phenolic compounds and its neuroprotective mechanisms in attenuating hydrogen peroxide-induced oxidative stress-related cytotoxicity is worth further exploration. PMID:26009648

  14. Hydrogen peroxide enteritis: the "snow white" sign.

    PubMed

    Bilotta, J J; Waye, J D

    1989-01-01

    Hydrogen peroxide is a useful disinfectant that has achieved widespread utility in varied clinical settings. We report an epidemic of hydrogen peroxide enteritis that developed in seven patients in our gastrointestinal endoscopy unit during a 2-week period in early 1988. During endoscopy, using recently sterilized endoscopes that were flushed with 3% hydrogen peroxide after the glutaraldehyde cycle, instantaneous blanching (the "snow white" sign) and effervescence were noted on the mucosal surfaces when the water button was depressed. No patient subsequently suffered morbidity or mortality associated with this peroxide enteritis, and the biopsy specimens revealed nonspecific inflammation. The toxicity of hydrogen peroxide when used in enema form is reviewed, as well as the pathogenesis of peroxide enteritis.

  15. Molecular Association and Structure of Hydrogen Peroxide.

    ERIC Educational Resources Information Center

    Giguere, Paul A.

    1983-01-01

    The statement is sometimes made in textbooks that liquid hydrogen peroxide is more strongly associated than water, evidenced by its higher boiling point and greater heat of vaporization. Discusses these and an additional factor (the nearly double molecular mass of the peroxide), focusing on hydrogen bonds and structure of the molecule. (JN)

  16. 7 CFR 58.431 - Hydrogen peroxide.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Hydrogen peroxide. 58.431 Section 58.431 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Material § 58.431 Hydrogen peroxide. The solution shall comply with the specification of the...

  17. 7 CFR 58.431 - Hydrogen peroxide.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Hydrogen peroxide. 58.431 Section 58.431 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Material § 58.431 Hydrogen peroxide. The solution shall comply with the specification of the...

  18. 7 CFR 58.431 - Hydrogen peroxide.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Hydrogen peroxide. 58.431 Section 58.431 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Material § 58.431 Hydrogen peroxide. The solution shall comply with the specification of the...

  19. 7 CFR 58.431 - Hydrogen peroxide.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Hydrogen peroxide. 58.431 Section 58.431 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Material § 58.431 Hydrogen peroxide. The solution shall comply with the specification of the...

  20. 7 CFR 58.431 - Hydrogen peroxide.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Hydrogen peroxide. 58.431 Section 58.431 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Material § 58.431 Hydrogen peroxide. The solution shall comply with the specification of the...

  1. Fundamentals of ISCO Using Hydrogen Peroxide

    EPA Science Inventory

    Hydrogen peroxide is a common oxidant that has been applied extensively with in situ chemical oxidation (ISCO). Because of its widespread use in this and other fields, it has been extensively researched. This research has revealed that hydrogen peroxide has very complex chemistry...

  2. Antioxidant properties and neuroprotective effects of isocampneoside II on hydrogen peroxide-induced oxidative injury in PC12 cells.

    PubMed

    Si, Chuan-Ling; Shen, Ting; Jiang, Yun-Yao; Wu, Lei; Yu, Guo-Jing; Ren, Xiao-Dan; Xu, Guang-Hui; Hu, Wei-Cheng

    2013-09-01

    Oxidative stress has been considered as a major cause of cell damage in various neurodegenerative disorders. One of the reasonable strategies for delaying the disease's progression is to prevent reactive oxygen species (ROS) mediated cellular injury by dietary or pharmaceutical augmentation of free radical scavengers. Isocampneoside II (ICD) is an active phenylethanoid glycoside isolated from the medicinal hardwood genus Paulownia. This study was designed to explore free radical scavenging potential of ICD in different in vitro systems and its protective role in hydrogen peroxide (H₂O₂)-induced oxidative stress and apoptotic death in cultured rat pheochromocytoma (PC12) cells. The results showed ICD eliminated approximately 80.75% superoxide radical at the concentration of 0.1mg/ml and inhibited metal chelating by 22.07% at 8 mg/ml. Additionally, ICD showed a strong ability on reducing power and provided protection against oxidative protein damage induced by hydroxyl radicals. Pretreatment of PC12 cells with ICD prior to H₂O₂ exposure elevated cell viability, enhanced activity of superoxide dismutase and catalase, and decreased levels of malondialdehyde and intracellular ROS. Furthermore, ICD inhibited cell apoptosis and Bax/Bcl-2 ratio induced by H₂O₂. These findings suggested ICD may be considered as a potential antioxidant agent and should encourage for further research in neurodegenerative diseases. PMID:23770344

  3. Antioxidant activity of herbaceous plant extracts protect against hydrogen peroxide-induced DNA damage in human lymphocytes

    PubMed Central

    2013-01-01

    Background Herbaceous plants containing antioxidants can protect against DNA damage. The purpose of this study was to evaluate the antioxidant substances, antioxidant activity, and protection of DNA from oxidative damage in human lymphocytes induced by hydrogen peroxide (H2O2). Our methods used acidic methanol and water extractions from six herbaceous plants, including Bidens alba (BA), Lycium chinense (LC), Mentha arvensis (MA), Plantago asiatica (PA), Houttuynia cordata (HC), and Centella asiatica (CA). Methods Antioxidant compounds such as flavonol and polyphenol were analyzed. Antioxidant activity was determined by the inhibition percentage of conjugated diene formation in a linoleic acid emulsion system and by trolox-equivalent antioxidant capacity (TEAC) assay. Their antioxidative capacities for protecting human lymphocyte DNA from H2O2-induced strand breaks was evaluated by comet assay. Results The studied plants were found to be rich in flavonols, especially myricetin in BA, morin in MA, quercetin in HC, and kaemperol in CA. In addition, polyphenol abounded in BA and CA. The best conjugated diene formation inhibition percentage was found in the acidic methanolic extract of PA. Regarding TEAC, the best antioxidant activity was generated from the acidic methanolic extract of HC. Water and acidic methanolic extracts of MA and HC both had better inhibition percentages of tail DNA% and tail moment as compared to the rest of the tested extracts, and significantly suppressed oxidative damage to lymphocyte DNA. Conclusion Quercetin and morin are important for preventing peroxidation and oxidative damage to DNA, and the leaves of MA and HC extracts may have excellent potential as functional ingredients representing potential sources of natural antioxidants. PMID:24279749

  4. Effects of various chemical compounds on spontaneous and hydrogen peroxide-induced reversion in strain TA104 of Salmonella typhimurium.

    PubMed

    Han, J S

    1992-04-01

    In experiments designed to determine which active oxygen species contribute to hydrogen peroxide (HP)-induced reversion in strain TA104 of Salmonella typhimurium, 1,10-phenanthroline (an iron chelator, which prevents the formation of hydroxyl radicals from HP and DNA-bound iron by the Fenton reaction), sodium azide (a singlet oxygen scavenger), and potassium iodide (an hydroxyl radical scavenger) inhibited HP-induced reversion. These results indicate that hydroxyl radicals generated from HP by the Fenton reaction, and perhaps singlet oxygen, contribute to HP-induced reversion in TA104. However, reduced glutathione (reduces Fe3+ to Fe2+ and/or HP to water), diethyldithiocarbamic acid (an inhibitor of superoxide dismutase), diethyl maleate (a glutathione scavenger), and 3-amino-1,2,4-triazole (an inhibitor of catalase) did not inhibit HP-induced reversion in TA104. Thus, superoxide radical anions and HP itself do not appear to be the cause of HP-induced reversion in this strain. In experiments on the effect of 5 common dietary compounds (beta-carotene, retinoic acid, and vitamins A, C and E), chlorophyllin (CHL), and ergothioneine, the frequency of revertants in TA104 increased above the spontaneous frequency in the presence of beta-carotene or vitamin C (about 2-fold) or vitamin A (about 3-fold). The 5 dietary antimutagens and CHL did not inhibit HP-induced reversion in TA104. However, L-ergothioneine inhibited HP-induced reversion in this strain. Therefore, it is likely that L-ergothioneine is a scavenger of hydroxyl radicals or an inhibitor of their formation, and perhaps of singlet oxygen, at the concentrations tested in TA104.

  5. Vapor Hydrogen Peroxide Sterilization Certification

    NASA Astrophysics Data System (ADS)

    Chen, Fei; Chung, Shirley; Barengoltz, Jack

    For interplanetary missions landing on a planet of potential biological interest, United States NASA planetary protection currently requires that the flight system must be assembled, tested and ultimately launched with the intent of minimizing the bioload taken to and deposited on the planet. Currently the only NASA approved microbial reduction method is dry heat sterilization process. However, with utilization of such elements as highly sophisticated electronics and sensors in modern spacecraft, this process presents significant materials challenges and is thus an undesirable bioburden reduction method to design engineers. The objective of this work is to introduce vapor hydrogen peroxide (VHP) as an alternative to dry heat microbial reduction to meet planetary protection requirements. The VHP sterilization technology is widely used by the medical industry, but high doses of VHP may degrade the performance of flight hardware, or compromise material compatibility. The goal of our study is determine the minimum VHP process conditions for PP acceptable microbial reduction levels. A series of experiments were conducted using Geobacillus stearothermophilus to determine VHP process parameters that provided significant reductions in spore viability while allowing survival of sufficient spores for statistically significant enumeration. In addition to the obvious process parameters -hydrogen peroxide concentration, number of pulses, and exposure duration -the investigation also considered the possible effect of environmental pa-rameters. Temperature, relative humidity, and material substrate effects on lethality were also studied. Based on the results, a most conservative D value was recommended. This recom-mended D value was also validated using VHP "hardy" strains that were isolated from clean-rooms and environmental populations collected from spacecraft relevant areas. The efficiency of VHP at ambient condition as well as VHP material compatibility will also be

  6. Neuroprotective Effects of Germinated Brown Rice against Hydrogen Peroxide Induced Cell Death in Human SH-SY5Y Cells

    PubMed Central

    Ismail, Norsharina; Ismail, Maznah; Fathy, Siti Farhana; Musa, Siti Nor Asma; Imam, Mustapha Umar; Foo, Jhi Biau; Iqbal, Shahid

    2012-01-01

    The neuroprotective and antioxidative effects of germinated brown rice (GBR), brown rice (BR) and commercially available γ-aminobutyric acid (GABA) against cell death induced by hydrogen peroxide (H2O2) in human neuroblastoma SH-SY5Y cells have been investigated. Results show that GBR suppressed H2O2-mediated cytotoxicity and induced G0/G1 phase cell cycle arrest in SH-SY5Y cells. Moreover, GBR reduced mitochondrial membrane potential (MMP) and prevented phosphatidylserine (PS) translocation in SH-SY5Y cells, key features of apoptosis, and subsequent cell death. GBR exhibited better neuroprotective and antioxidative activities as compared to BR and GABA. These results indicate that GBR possesses high antioxidative activities and suppressed cell death in SH-SY5Y cells by blocking the cell cycle re-entry and apoptotic mechanisms. Therefore, GBR could be developed as a value added functional food to prevent neurodegenerative diseases caused by oxidative stress and apoptosis. PMID:22949825

  7. Evaluating the effects of galbanic acid on hydrogen peroxide-induced oxidative DNA damage in human lymphocytes

    PubMed Central

    Shirani, Kobra; Behravan, Javad; Mosaffa, Fatemeh; Iranshahi, Mehrdad; Mehmankhah, Babak; Razavi-Azarkhiavi, Kamal; Karimi, Gholamreza

    2014-01-01

    Objective: Ferula szowitsiana has been widely used for medicinal purposes around the world. The anti-oxidant effect of F. szowitsiana had been proved. The current study aims to determine the protective effects of galbanic acid, a sesquiterpene coumarin from F. szowitsiana, against hydrogen peroxide (H2O2) - induced oxidative DNA damage in human lymphocytes. Materials and Methods: Human lymphocytes were incubated with H2O2 (0, 25, 50, 100, and 200 µM), galbanic acid (200 and 400 µM) and a combination of galbanic acid (200 and 400 µM) and H2O2 (25 µM) at 4 C for 30 minutes. Solvents of galbanic acid without H2O2 were used as negative controls. Results: The findings of this study demonstrated that H2O2 exposure leads to a significant concentration-dependent increase in DNA damage. Galbanic acid did not cause DNA damage compared with the control cells. Data showed that galbanic acid does not have a protective effect against H2O2-induced oxidative DNA damage in human lymphocytes. Conclusion: According to the results, it is concluded that the capability of F. szowitsiana in reducing reactive oxygen species and the anti-inflammatory property of its methanolic extract may be due to its other ingredients. PMID:25386396

  8. s-Ethyl Cysteine and s-Methyl Cysteine Protect Human Bronchial Epithelial Cells Against Hydrogen Peroxide Induced Injury.

    PubMed

    Hsia, Te-chun; Yin, Mei-chin

    2015-09-01

    Protective effects and actions from s-ethyl cysteine (SEC) and s-methyl cysteine (SMC) for BEAS-2B cells were examined. BEAS-2B cells were pretreated with SEC or SMC at 4, 8, or 16 μmol/L, and followed by hydrogen peroxide (H2 O2 ) treatment. Data showed that H2 O2 enhanced Bax, caspase-3 and caspase-8 expression, and declined Bcl-2 expression. However, SEC or SMC dose-dependently decreased caspase-3 expression and reserved Bcl-2 expression. H2 O2 increased reactive oxygen species (ROS) production, and lowered glutathione level, glutathione peroxide, and glutathione reductase activities in BEAS-2B cells. SEC or SMC pretreatments reduced ROS generation, and maintained glutathione redox cycle in those cells. H2 O2 upregulated the expression of both p47(phox) and gp91(phox) . SEC and SMC downregulated p47(phox) expression. SEC or SMC at 8 and 16 μmol/L decreased H2 O2 -induced release of inflammatory cytokines. H2 O2 stimulated the activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase. SEC and SMC pretreatments dose-dependently downregulated NF-κB p65 and p-p38 expression. Pyrrolidine dithiocarbamate or SB203580 inhibited NF-κB activation and p38 phosphorylation; thus, SEC or SMC pretreatments failed to affect protein expression of these factors. These novel findings suggest that SEC or SMC could protect bronchial cells and benefit respiratory epithelia stability and functions.

  9. Curcumin Attenuates Hydrogen Peroxide-Induced Premature Senescence via the Activation of SIRT1 in Human Umbilical Vein Endothelial Cells.

    PubMed

    Sun, Yueliu; Hu, Xiaorong; Hu, Gangying; Xu, Changwu; Jiang, Hong

    2015-01-01

    Endothelial senescence has been proposed to be involved in endothelial dysfunction and atherogenesis. Curcumin, a natural phenol, possesses antioxidant and anti-inflammatory properties. However, the effect of curcumin on endothelial senescence is unclear. This study explores the effect of curcumin on hydrogen peroxide (H2O2)-induced endothelial premature senescence and the mechanisms involved. Human umbilical vein endothelial cells (HUVECs) were cultured, and premature senescence was induced with 100 µM H2O2. Results showed that pretreatment with curcumin significantly attenuated the H2O2-induced HUVECs' premature senescence, which was evidenced by a decreased percentage of senescence-associated β-galactosidase positive cells, improved cell division and decreased expression of senescence-associated protein p21 (all p<0.05). Pretreatment with curcumin decreased oxidative stress and apoptosis in H2O2-treated HUVECs. Treatment of HUVECs with H2O2 also down-regulated the phosphorylation of endothelial nitric oxide synthase (eNOS), decreased the level of nitric oxide in the culture medium, and inhibited the protein expression and enzymatic activity of silent information regulator 1 (SIRT1), while pretreatment with curcumin partly reversed these effects (all p<0.05). Treatment with curcumin alone enhanced the enzymatic activity of SIRT1, but didn't affect cellular senescence, cell growth or apoptosis compared to the Control. The inhibition of SIRT1 using SIRT1 short interfering RNA (siRNA) could decrease the expression and phosphorylation of eNOS and abrogate the protective effect of curcumin on H2O2-induced premature senescence. These findings suggest that curcumin could attenuate oxidative stress-induced HUVECs' premature senescence via the activation of SIRT1.

  10. Piper sarmentosum as an antioxidant on oxidative stress in human umbilical vein endothelial cells induced by hydrogen peroxide*

    PubMed Central

    Hafizah, Abdul Hamid; Zaiton, Zakaria; Zulkhairi, Amom; Mohd Ilham, Adenan; Nor Anita, Megat Mohd Nordin; Zaleha, Abdullah Mahdy

    2010-01-01

    Endothelial cell death due to increased reactive oxygen species (ROS) may contribute to the initial endothelial injury, which promotes atherosclerotic lesion formation. Piper sarmentosum (PS), a natural product, has been shown to have an antioxidant property, which is hypothesized to inhibit production of ROS and prevent cell injury. Thus, the present study was designed to determine the effects of PS on the hydrogen peroxide (H2O2)-induced oxidative cell damage in cultured human umbilical vein endothelial cells (HUVECs). In this experiment, HUVECs were obtained by collagenase perfusion of the large vein in the umbilical cord and cultured in medium M200 supplemented with low serum growth supplementation (LSGS). HUVECs were treated with various concentrations of H2O2 (0–1000 µmol/L) and it was observed that 180 µmol/L H2O2 reduced cell viability by 50% as denoted by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Using the above concentration as the positive control, the H2O2-induced HUVECs were concomitantly treated with various concentrations (100, 150, 250 and 300 µg/ml) of three different extracts (aqueous, methanol and hexane) of PS. Malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) levels showed a significant increase (P<0.05) in HUVECs compared to the negative control. However, PS extracts showed a protective effect on HUVECs from H2O2-induced cell apoptosis with a significant reduction in MDA, SOD, CAT and GPX levels (P<0.05). Furthermore, PS had exhibited ferric reducing antioxidant power with its high phenolic content. Hence, it was concluded that PS plays a beneficial role in reducing oxidative stress in H2O2-induced HUVECs. PMID:20443214

  11. High temperature decomposition of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2004-01-01

    Nitric oxide (NO) is oxidized into nitrogen dioxide (NO.sub.2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydroperoxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

  12. High temperature decomposition of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2011-01-01

    Nitric oxide (NO) is oxidized into nitrogen dioxide (NO.sub.2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydroperoxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

  13. Generation of hydrogen peroxide in chloroplasts of Arabidopsis overexpressing glycolate oxidase as an inducible system to study oxidative stress.

    PubMed

    Fahnenstich, Holger; Scarpeci, Telma E; Valle, Estela M; Flügge, Ulf-Ingo; Maurino, Verónica G

    2008-10-01

    Arabidopsis (Arabidopsis thaliana) overexpressing glycolate oxidase (GO) in chloroplasts accumulates both hydrogen peroxide (H(2)O(2)) and glyoxylate. GO-overexpressing lines (GO plants) grown at 75 micromol quanta m(-2) s(-1) show retarded development, yellowish rosettes, and impaired photosynthetic performance, while at 30 micromol quanta m(-2) s(-1), this phenotype virtually disappears. The GO plants develop oxidative stress lesions under photorespiratory conditions but grow like wild-type plants under nonphotorespiratory conditions. GO plants coexpressing enzymes that further metabolize glyoxylate but still accumulate H(2)O(2) show all features of the GO phenotype, indicating that H(2)O(2) is responsible for the GO phenotype. The GO plants can complete their life cycle, showing that they are able to adapt to the stress conditions imposed by the accumulation of H(2)O(2) during the light period. Moreover, the data demonstrate that a response to oxidative stress is installed, with increased expression and/or activity of known oxidative stress-responsive components. Hence, the GO plants are an ideal noninvasive model system in which to study the effects of H(2)O(2) directly in the chloroplasts, because H(2)O(2) accumulation is inducible and sustained perturbations can reproducibly be provoked by exposing the plants to different ambient conditions.

  14. Microcalorimetric Measurements of Hydrogen Peroxide Stability

    NASA Technical Reports Server (NTRS)

    Davis, Dennis D.; Hornung, Steven D.; Baker, Dave L.

    1999-01-01

    Recent interest in propellants with nontoxic reaction products has led to a resurgence of interest in hydrogen peroxide for various propellant applications. Because hydrogen peroxide is sensitive to contaminants and materials interactions, stability and shelf life are issues. A relatively new, ultrasensitive heat measurement technique, isothermal microcalorimetry, is being used at the White Sands Test Facility to monitor the decomposition of hydrogen peroxide at near ambient temperatures. Isothermal microcalorimetry measures the beat flow from a reaction vessel into a surrounding heat sink. In these applications, microcalorimetry is approximately 1,000 times more sensitive than accelerating rate calorimetry or differential scanning calorimetry for measuring thermal events. Experimental procedures have been developed for the microcalorimetric measurement of the ultra-small beat effects caused by incompatible interactions of hydrogen peroxide. The decomposition rates of hydrogen peroxide at the picomole/sec/gram level have been measured showing the effects of stabilizers and peroxide concentration. Typical measurements are carried out at 40 C over a 24-hour period, This paper describes a method for the conversion of the heat flow measurements to chemical reaction rates based on thermochemical considerations. The reaction rates are used in a study of the effects of stabilizer levels on the decomposition of propellant grade hydrogen peroxide.

  15. Membrane transport of hydrogen peroxide.

    PubMed

    Bienert, Gerd P; Schjoerring, Jan K; Jahn, Thomas P

    2006-08-01

    Hydrogen peroxide (H2O2) belongs to the reactive oxygen species (ROS), known as oxidants that can react with various cellular targets thereby causing cell damage or even cell death. On the other hand, recent work has demonstrated that H2O2 also functions as a signalling molecule controlling different essential processes in plants and mammals. Because of these opposing functions the cellular level of H2O2 is likely to be subjected to tight regulation via processes involved in production, distribution and removal. Substantial progress has been made exploring the formation and scavenging of H2O2, whereas little is known about how this signal molecule is transported from its site of origin to the place of action or detoxification. From work in yeast and bacteria it is clear that the diffusion of H2O2 across membranes is limited. We have now obtained direct evidence that selected aquaporin homologues from plants and mammals have the capacity to channel H2O2 across membranes. The main focus of this review is (i) to summarize the most recent evidence for a signalling role of H2O2 in various pathways in plants and mammals and (ii) to discuss the relevance of specific transport of H2O2.

  16. Hydrogen peroxide functions as a secondary messenger for brassinosteroids-induced CO2 assimilation and carbohydrate metabolism in Cucumis sativus.

    PubMed

    Jiang, Yu-ping; Cheng, Fei; Zhou, Yan-hong; Xia, Xiao-jian; Mao, Wei-hua; Shi, Kai; Chen, Zhi-xiang; Yu, Jing-quan

    2012-10-01

    Brassinosteroids (BRs) are potent regulators of photosynthesis and crop yield in agricultural crops; however, the mechanism by which BRs increase photosynthesis is not fully understood. Here, we show that foliar application of 24-epibrassinolide (EBR) resulted in increases in CO(2) assimilation, hydrogen peroxide (H(2)O(2)) accumulation, and leaf area in cucumber. H(2)O(2) treatment induced increases in CO(2) assimilation whilst inhibition of the H(2)O(2) accumulation by its generation inhibitor or scavenger completely abolished EBR-induced CO(2) assimilation. Increases of light harvesting due to larger leaf areas in EBR- and H(2)O(2)-treated plants were accompanied by increases in the photochemical efficiency of photosystem II (Φ(PSII)) and photochemical quenching coefficient (q(P)). EBR and H(2)O(2) both activated carboxylation efficiency of ribulose-1,5-bisphosphate oxygenase/carboxylase (Rubisco) from analysis of CO(2) response curve and in vitro measurement of Rubisco activities. Moreover, EBR and H(2)O(2) increased contents of total soluble sugar, sucrose, hexose, and starch, followed by enhanced activities of sugar metabolism such as sucrose phosphate synthase, sucrose synthase, and invertase. Interestingly, expression of transcripts of enzymes involved in starch and sugar utilization were inhibited by EBR and H(2)O(2). However, the effects of EBR on carbohydrate metabolisms were reversed by the H(2)O(2) generation inhibitor diphenyleneodonium (DPI) or scavenger dimethylthiourea (DMTU) pretreatment. All of these results indicate that H(2)O(2) functions as a secondary messenger for EBR-induced CO(2) assimilation and carbohydrate metabolism in cucumber plants. Our study confirms that H(2)O(2) mediates the regulation of photosynthesis by BRs and suggests that EBR and H(2)O(2) regulate Calvin cycle and sugar metabolism via redox signaling and thus increase the photosynthetic potential and yield of crops.

  17. Hydrogen peroxide treatment of TCE contaminated soil

    SciTech Connect

    Hurst, D.H.; Robinson, K.G.; Siegrist, R.L.

    1993-12-31

    Solvent contaminated soils are ubiquitous in the industrial world and represent a significant environmental hazard due to their persistence and potentially negative impacts on human health and the environment. Environmental regulations favor treatment of soils with options which reduce the volume and toxicity of contaminants in place. One such treatment option is the in-situ application of hydrogen peroxide to soils contaminated with chlorinated solvents such as trichloroethylene (TCE). This study investigated hydrogen peroxide mass loading rates on removal of TCE from soils of varying organic matter content. Batch experiments conducted on contaminated loam samples using GC headspace analysis showed up to 80% TCE removal upon peroxide treatment. Column experiments conducted on sandy loam soils with high organic matter content showed only 25% TCE removal, even at hydrogen peroxide additions of 25 g peroxide per kg soil.

  18. NOX4-dependent Hydrogen peroxide promotes shear stress-induced SHP2 sulfenylation and eNOS activation.

    PubMed

    Sánchez-Gómez, Francisco J; Calvo, Enrique; Bretón-Romero, Rosa; Fierro-Fernández, Marta; Anilkumar, Narayana; Shah, Ajay M; Schröder, Katrin; Brandes, Ralf P; Vázquez, Jesús; Lamas, Santiago

    2015-12-01

    Laminar shear stress (LSS) triggers signals that ultimately result in atheroprotection and vasodilatation. Early responses are related to the activation of specific signaling cascades. We investigated the participation of redox-mediated modifications and in particular the role of hydrogen peroxide (H2O2) in the sulfenylation of redox-sensitive phosphatases. Exposure of vascular endothelial cells to short periods of LSS (12 dyn/cm(2)) resulted in the generation of superoxide radical anion as detected by the formation of 2-hydroxyethidium by HPLC and its subsequent conversion to H2O2, which was corroborated by the increase in the fluorescence of the specific peroxide sensor HyPer. By using biotinylated dimedone we detected increased total protein sulfenylation in the bovine proteome, which was dependent on NADPH oxidase 4 (NOX4)-mediated generation of peroxide. Mass spectrometry analysis allowed us to identify the phosphatase SHP2 as a protein susceptible to sulfenylation under LSS. Given the dependence of FAK activity on SHP2 function, we explored the role of FAK under LSS conditions. FAK activation and subsequent endothelial NO synthase (eNOS) phosphorylation were promoted by LSS and both processes were dependent on NOX4, as demonstrated in lung endothelial cells isolated from NOX4-null mice. These results support the idea that LSS elicits redox-sensitive signal transduction responses involving NOX4-dependent generation of hydrogen peroxide, SHP2 sulfenylation, and ulterior FAK-mediated eNOS activation.

  19. Simultaneous determination of superoxide and hydrogen peroxide in macrophage RAW 264.7 cell extracts by microchip electrophoresis with laser-induced fluorescence detection.

    PubMed

    Li, Hongmin; Li, Qingling; Wang, Xu; Xu, Kehua; Chen, Zhenzhen; Gong, Xiaocong; Liu, Xin; Tong, Lili; Tang, Bo

    2009-03-15

    A method for the first time to simultaneously determine superoxide and hydrogen peroxide in macrophage RAW 264.7 cell extracts by microchip electrophoresis with laser-induced fluorescence detection (MCE-LIF) was developed. 2-Chloro-1,3-dibenzothiazolinecyclohexene (DBZTC) and bis(p-methylbenzenesulfonyl) dichlorofluorescein (FS), two probes that can be specifically derivatized by superoxide and hydrogen peroxide, respectively, were synthesized and used. Parameters influencing the derivatization and on-chip separation were optimized. With the use of a HEPES (20 mM, pH 7.4) running buffer, a 50 mm long separation channel, and a separation voltage of 1800 V, baseline separation was achieved within 48 s for the two derivatization products, DBZTC-oxide (DBO) and 2,7-dichlorofluorescein (DCF). The linearity ranges of the method were 0.08-5.0 and 0.02-5.0 microM with detection limits (signal-to-noise ratio = 3) of 10 nM (1.36 amol) and 5.6 nM (0.76 amol) for superoxide and hydrogen peroxide, respectively. The relative standard deviations (RSDs) of migration time and peak area were less than 2.0% and 5.0%, respectively. The recoveries of the cell extract samples spiked with 1.0 microM standard solutions were 96.1% and 93.0% for superoxide and hydrogen peroxide, respectively. With the use of this method, superoxide and hydrogen peroxide in phorbol myristate acetate (PMA)-stimulated macrophage RAW 264.7 cell extracts were found to be 0.78 and 1.14 microM, respectively. The method has paved a way for simultaneously determining two or more reactive oxygen species (ROS) in a biological system with high resolution.

  20. Hydrogen Peroxide as a Sustainable Energy Carrier: Electrocatalytic Production of Hydrogen Peroxide and the Fuel Cell

    PubMed Central

    Fukuzumi, Shunichi; Yamada, Yusuke; Karlin, Kenneth D.

    2012-01-01

    This review describes homogeneous and heterogeneous catalytic reduction of dioxygen with metal complexes focusing on the catalytic two-electron reduction of dioxygen to produce hydrogen peroxide. Whether two-electron reduction of dioxygen to produce hydrogen peroxide or four-electron O2-reduction to produce water occurs depends on the types of metals and ligands that are utilized. Those factors controlling the two processes are discussed in terms of metal-oxygen intermediates involved in the catalysis. Metal complexes acting as catalysts for selective two-electron reduction of oxygen can be utilized as metal complex-modified electrodes in the electrocatalytic reduction to produce hydrogen peroxide. Hydrogen peroxide thus produced can be used as a fuel in a hydrogen peroxide fuel cell. A hydrogen peroxide fuel cell can be operated with a one-compartment structure without a membrane, which is certainly more promising for the development of low-cost fuel cells as compared with two compartment hydrogen fuel cells that require membranes. Hydrogen peroxide is regarded as an environmentally benign energy carrier because it can be produced by the electrocatalytic two-electron reduction of O2, which is abundant in air, using solar cells; the hydrogen peroxide thus produced could then be readily stored and then used as needed to generate electricity through the use of hydrogen peroxide fuel cells. PMID:23457415

  1. Hydrogen Peroxide as a Sustainable Energy Carrier: Electrocatalytic Production of Hydrogen Peroxide and the Fuel Cell.

    PubMed

    Fukuzumi, Shunichi; Yamada, Yusuke; Karlin, Kenneth D

    2012-11-01

    This review describes homogeneous and heterogeneous catalytic reduction of dioxygen with metal complexes focusing on the catalytic two-electron reduction of dioxygen to produce hydrogen peroxide. Whether two-electron reduction of dioxygen to produce hydrogen peroxide or four-electron O2-reduction to produce water occurs depends on the types of metals and ligands that are utilized. Those factors controlling the two processes are discussed in terms of metal-oxygen intermediates involved in the catalysis. Metal complexes acting as catalysts for selective two-electron reduction of oxygen can be utilized as metal complex-modified electrodes in the electrocatalytic reduction to produce hydrogen peroxide. Hydrogen peroxide thus produced can be used as a fuel in a hydrogen peroxide fuel cell. A hydrogen peroxide fuel cell can be operated with a one-compartment structure without a membrane, which is certainly more promising for the development of low-cost fuel cells as compared with two compartment hydrogen fuel cells that require membranes. Hydrogen peroxide is regarded as an environmentally benign energy carrier because it can be produced by the electrocatalytic two-electron reduction of O2, which is abundant in air, using solar cells; the hydrogen peroxide thus produced could then be readily stored and then used as needed to generate electricity through the use of hydrogen peroxide fuel cells.

  2. Vanadate induces apoptosis in epidermal JB6 P+ cells via hydrogen peroxide-mediated reactions.

    PubMed

    Ye, J; Ding, M; Leonard, S S; Robinson, V A; Millecchia, L; Zhang, X; Castranova, V; Vallyathan, V; Shi, X

    1999-12-01

    Apoptosis is a physiological mechanism for the control of DNA integrity in mammalian cells. Vanadium induces both DNA damage and apoptosis. It is suggested that vanadium-induced apoptosis serves to eliminate DNA-damaged cells. This study is designed to clarify a role of reactive oxygen species in the mechanism of apoptosis induced by vanadium. We established apoptosis model with murine epidermal JB6 P+ cells in the response to vanadium stimulation. Apoptosis was detected by a cell death ELISA assay and morphological analysis. The result shows that apoptosis induced by vanadate is dose-dependent, reaching its saturation level at a concentration of 100 microM vanadate. Vanadyl (IV) can also induce apoptosis albeit with lesser potency. A role of reactive oxygen species was analyzed by multiple reagents including specific scavengers of different reactive oxygen species. The result shows that vanadate-induced apoptosis is enhanced by NADPH, superoxide dismutase and sodium formate, but was inhibited by catalase and deferoxamine. Cells exposed to vanadium consume more molecular oxygen and at the same time, produce more H2O2 as measured by the change in fluorescence of scopoletin in the presence of horseradish peroxidase. This change in oxygen consumption and H2O2 production is enhanced by NADPH. Taken together, these results show that vanadate induces apoptosis in epidermal cells and H2O2 induced by vanadate plays a major role in this process. PMID:10705990

  3. Ethylene mediates brassinosteroid-induced stomatal closure via Gα protein-activated hydrogen peroxide and nitric oxide production in Arabidopsis.

    PubMed

    Shi, Chenyu; Qi, Cheng; Ren, Hongyan; Huang, Aixia; Hei, Shumei; She, Xiaoping

    2015-04-01

    Brassinosteroids (BRs) are essential for plant growth and development; however, whether and how they promote stomatal closure is not fully clear. In this study, we report that 24-epibrassinolide (EBR), a bioactive BR, induces stomatal closure in Arabidopsis (Arabidopsis thaliana) by triggering a signal transduction pathway including ethylene synthesis, the activation of Gα protein, and hydrogen peroxide (H(2)O(2)) and nitric oxide (NO) production. EBR initiated a marked rise in ethylene, H(2)O(2) and NO levels, necessary for stomatal closure in the wild type. These effects were abolished in mutant bri1-301, and EBR failed to close the stomata of gpa1 mutants. Next, we found that both ethylene and Gα mediate the inductive effects of EBR on H(2)O(2) and NO production. EBR-triggered H(2)O(2) and NO accumulation were canceled in the etr1 and gpa1 mutants, but were strengthened in the eto1-1 mutant and the cGα line (constitutively overexpressing the G protein α-subunit AtGPA1). Exogenously applied H(2)O(2) or sodium nitroprusside (SNP) rescued the defects of etr1-3 and gpa1 or etr1 and gpa1 mutants in EBR-induced stomatal closure, whereas the stomata of eto1-1/AtrbohF and cGα/AtrbohF or eto1-1/nia1-2 and cGα/nia1-2 constructs had an analogous response to H(2)O(2) or SNP as those of AtrbohF or Nia1-2 mutants. Moreover, we provided evidence that Gα plays an important role in the responses of guard cells to ethylene. Gα activator CTX largely restored the lesion of the etr1-3 mutant, but ethylene precursor ACC failed to rescue the defects of gpa1 mutants in EBR-induced stomatal closure. Lastly, we demonstrated that Gα-activated H(2)O(2) production is required for NO synthesis. EBR failed to induce NO synthesis in mutant AtrbohF, but it led to H(2)O(2) production in mutant Nia1-2. Exogenously applied SNP rescued the defect of AtrbohF in EBR-induced stomatal closure, but H(2)O(2) did not reverse the lesion of EBR-induced stomatal closure in Nia1-2. Together, our

  4. Isothermal Decomposition of Hydrogen Peroxide Dihydrate

    NASA Technical Reports Server (NTRS)

    Loeffler, M. J.; Baragiola, R. A.

    2011-01-01

    We present a new method of growing pure solid hydrogen peroxide in an ultra high vacuum environment and apply it to determine thermal stability of the dihydrate compound that forms when water and hydrogen peroxide are mixed at low temperatures. Using infrared spectroscopy and thermogravimetric analysis, we quantified the isothermal decomposition of the metastable dihydrate at 151.6 K. This decomposition occurs by fractional distillation through the preferential sublimation of water, which leads to the formation of pure hydrogen peroxide. The results imply that in an astronomical environment where condensed mixtures of H2O2 and H2O are shielded from radiolytic decomposition and warmed to temperatures where sublimation is significant, highly concentrated or even pure hydrogen peroxide may form.

  5. NASA Hydrogen Peroxide Propellant Hazards Technical Manual

    NASA Technical Reports Server (NTRS)

    Baker, David L.; Greene, Ben; Frazier, Wayne

    2005-01-01

    The Fire, Explosion, Compatibility and Safety Hazards of Hydrogen Peroxide NASA technical manual was developed at the NASA Johnson Space Center White Sands Test Facility. NASA Technical Memorandum TM-2004-213151 covers topics concerning high concentration hydrogen peroxide including fire and explosion hazards, material and fluid reactivity, materials selection information, personnel and environmental hazards, physical and chemical properties, analytical spectroscopy, specifications, analytical methods, and material compatibility data. A summary of hydrogen peroxide-related accidents, incidents, dose calls, mishaps and lessons learned is included. The manual draws from art extensive literature base and includes recent applicable regulatory compliance documentation. The manual may be obtained by United States government agencies from NASA Johnson Space Center and used as a reference source for hazards and safe handling of hydrogen peroxide.

  6. Ultraviolet absorption cross sections of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Lin, C. L.; Rohatgi, N. K.; Demore, W. B.

    1978-01-01

    Absorption cross-sections of hydrogen peroxide vapor and of neutral aqueous solutions of hydrogen peroxide were measured in the wavelength range from 195 to 350 nm at 296 K. The spectrophotometric procedure is described, and the reported cross-sections are compared with values obtained by other researchers. Photodissociation coefficients of atmospheric H2O2 were calculated for direct absorption of unscattered solar radiation, and the vertical distributions of these coefficients are shown for various solar zenith angles.

  7. Protective effect of Cymbopogon citratus on hydrogen peroxide-induced oxidative stress in the reproductive system of male rats.

    PubMed

    Rahim, Saleh M; Taha, Ekhlass M; Mubark, Zaid M; Aziz, Salam S; Simon, K D; Mazlan, A G

    2013-12-01

    Cymbopogon citratus (C. citratus) has antioxidant, anti-inflammatory, and chemoprotective properties. This study was conducted to evaluate the protective effect of C. citratus aqueous extract against hydrogen peroxide (H2O2)-induced oxidative stress and injury in the reproductive system of male rats. The twenty-five rats used in this study were divided into five groups, comprised of five rats each. The control group received standard food and drink. The H2O2 group received standard food and water with 0.5% H2O2. The rats in the H2O2 + C. citratus group and H2O2 + vitamin E group received standard food, H2O2, and C. citratus [100 mg·kg(-1) body weight (bw)], or vitamin E as an antioxidant reference (500 mg·kg(-1) bw), respectively. The C. citratus group was given C. citratus (100 mg·kg(-1) bw) in addition to the standard food and drink. The treatments were administered for 30 days. The H2O2 treatment significantly (P < 0.05) decreased body, testicular, and epididymal weight, as well as glutathione (GSH) level, but markedly increased malonaldehyde (MDA) in serum and testes homogenates. The rats treated with H2O2 exhibited testicular degeneration and significant reduction in sperm viability, motility, count, and rate of normal sperm. The C. citratus, vitamin E, and H2O2 treatment significantly (P < 0.05) increased the body, testicular, and epididymal weight, testosterone level, the values of the various sperm characteristics, and GSH. However, this treatment markedly reduced MDA in serum and testes homogenates, as well as testicular histopathological alterations in the H2O2-treated rats. The C. citratus aqueous extract reduced oxidative stress and protected male rats against H2O2-induced reproductive system injury.

  8. Ferulic acid renders protection to HEK293 cells against oxidative damage and apoptosis induced by hydrogen peroxide.

    PubMed

    Bian, Yuan-Yuan; Guo, Jia; Majeed, Hamid; Zhu, Ke-Xue; Guo, Xiao-Na; Peng, Wei; Zhou, Hui-Ming

    2015-08-01

    The application of antioxidants has been considered as an important and effective approach against conditions in which oxidative stress occurs. Especially, ferulic acid (FA) is an important antioxidant which exerts potency against cellular damage in the presence of oxidants. In the current study, the resistance effect of FA on hydrogen peroxide (H2O2)-stressed human embryonic kidney 293 cells (HEK293) in vitro was investigated. FA (1 mM) increased HEK293 cells' viability and significantly reduced H2O2-induced cellular apoptosis, which was confirmed with flow cytometry and morphological results. Cell cycle analysis indicated low percentage of sub-G0 population of FA-treated HEK293 cells that confirmed its resistance effect. The FA-treated HEK293 cells followed by H2O2 exposure resulted in decreased ROS levels compared to control (H2O2-treated only). The results indicated that pretreatment of FA on cell prior to H2O2 exposure could significantly improve cell survival and increase catalase (CAT) and superoxide dismutase (SOD) levels. On the other hand, reduction in the levels of MDA and ROS was obvious. It can be concluded that FA may protect HEK293 cells from injury induced by H2O2 through regulation of intracellular antioxidant enzyme activities and cell cycle distribution. The reduction in mitochondrial membrane potential was also inhibited by FA treatment. These results suggested the importance of naturally occurring antioxidants such as FA in therapeutic intervention methodology against oxidative stress-related diseases.

  9. Hydrogen peroxide induces a greater contraction in mesenteric arteries of spontaneously hypertensive rats through thromboxane A(2) production.

    PubMed

    Gao, Y J; Lee, R M

    2001-12-01

    1. Hydrogen peroxide (H(2)O(2)) caused a transient contraction in endothelium-intact (E+) and -denuded (E-) mesenteric arteries (MA) from 8 - 10-month-old spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY) in a concentration-dependent manner (10(-5) M to 10(-3) M). 2. The contraction to H(2)O(2) in MA (E+ or E-) was greater in SHR than in WKY. Removal of endothelium potentiated the contraction to H(2)O(2) in WKY but not in SHR. Tachyphylaxis to H(2)O(2) was less prominent in SHR than in WKY. 3. The contraction of aorta to H(2)O(2) (5 x 10(-4) M), expressed as a percentage of 80 mM KCl-induced contraction, was approximately half of that found in the MA. A greater contraction was found in E+ but not E- SHR aortic rings. 4. The contraction of MA to H(2)O(2) (5 x 10(-4) M) was greatly inhibited by SQ 29548 and ICI 192605 (thromboxane A(2) (TXA(2))/prostaglandin H(2) receptor antagonists), quinacrine (a phospholipase A(2) (PLA(2)) inhibitor), indomethacin and diclofenac (cyclooxygenase (COX) inhibitors), and furegrelate (a TXA(2) synthase inhibitor). 5. Production of thromboxane B(2) induced by H(2)O(2) (5 x 10(-4) M) was greater in SHR MA than in WKY, and was inhibited by quinacrine, indomethacin and diclofenac, and furegrelate, but not by SQ 29584 and ICI 192605. 6. These results suggested (1) that SHR MA exhibits a higher contraction involving an increased smooth muscle reactivity and less tachyphylaxis to H(2)O(2) than WKY; (2) that a greater production of TXA(2) through activation of PLA(2)-COX-TXA(2) synthase pathway appeared to be responsible for the enhanced contraction in SHR MA. The enhanced vascular response to H(2)O(2) may be related to hypertension in SHR.

  10. PKCα and HMGB1 antagonistically control hydrogen peroxide-induced poly-ADP-ribose formation

    PubMed Central

    Andersson, Anneli; Bluwstein, Andrej; Kumar, Nitin; Teloni, Federico; Traenkle, Jens; Baudis, Michael; Altmeyer, Matthias; Hottiger, Michael O.

    2016-01-01

    Harmful oxidation of proteins, lipids and nucleic acids is observed when reactive oxygen species (ROS) are produced excessively and/or the antioxidant capacity is reduced, causing ‘oxidative stress’. Nuclear poly-ADP-ribose (PAR) formation is thought to be induced in response to oxidative DNA damage and to promote cell death under sustained oxidative stress conditions. However, what exactly triggers PAR induction in response to oxidative stress is incompletely understood. Using reverse phase protein array (RPPA) and in-depth analysis of key stress signaling components, we observed that PAR formation induced by H2O2 was mediated by the PLC/IP3R/Ca2+/PKCα signaling axis. Mechanistically, H2O2-induced PAR formation correlated with Ca2+-dependent DNA damage, which, however, was PKCα-independent. In contrast, PAR formation was completely lost upon knockdown of PKCα, suggesting that DNA damage alone was not sufficient for inducing PAR formation, but required a PKCα-dependent process. Intriguingly, the loss of PAR formation observed upon PKCα depletion was overcome when the chromatin structure-modifying protein HMGB1 was co-depleted with PKCα, suggesting that activation and nuclear translocation of PKCα releases the inhibitory effect of HMGB1 on PAR formation. Together, these results identify PKCα and HMGB1 as important co-regulators involved in H2O2-induced PAR formation, a finding that may have important relevance for oxidative stress-associated pathophysiological conditions. PMID:27198223

  11. Protective effect of trifluoperazine on hydrogen peroxide-induced apoptosis in PC12 cells.

    PubMed

    Liu, Shichang; Han, Yangguang; Zhang, Tao; Yang, Zhuo

    2011-02-01

    This study investigated effects of trifluoperazine (TFP) against the cytotoxicity induced by H₂O₂ in PC12 cells and the mechanisms thereof. Different concentrations of H₂O₂ (100-500 μM) induced a significant decrease in cell viability accompanied by increased oxidative stress and cell apoptosis. Pretreatment with TFP inhibited H₂O₂-induced cell viability loss. The flow cytometric assay showed that TFP can inhibit intracellular reactive oxygen species (ROS) generation and reduce the cell apoptosis. The electrophysiological recordings indicated that when treated with H₂O₂, the calcium current was significantly increased. Pretreatment with TFP increased mitochondrial membrane potential (MMP) in cells of oxidative injury. These results suggested that TFP can reduce apoptosis by inhibiting ROS generation and preventing loss of MMP in cells. Meanwhile, the protective effect of TFP on the cell apoptosis may be related to the calcium overload. TFP may inhibit the calcium overload process to achieve the protection against apoptosis.

  12. Hydrogen-peroxide-induced oxidative stress responses in Desulfovibrio vulgaris Hildenborough

    SciTech Connect

    Zhou, A.; He, Z.; Redding-Johanson, A.M.; Mukhopadhyay, A.; Hemme, C.L.; Joachimiak, M.P.; Bender, K.S.; Keasling, J.D.; Stahl, D.A.; Fields, M.W.; Hazen, T.C.; Arkin, A.P.; Wall, J.D.; Zhou, J.; Luo, F.; Deng, Y.; He, Q.

    2010-07-01

    To understand how sulphate-reducing bacteria respond to oxidative stresses, the responses of Desulfovibrio vulgaris Hildenborough to H{sub 2}O{sub 2}-induced stresses were investigated with transcriptomic, proteomic and genetic approaches. H{sub 2}O{sub 2} and induced chemical species (e.g. polysulfide, ROS) and redox potential shift increased the expressions of the genes involved in detoxification, thioredoxin-dependent reduction system, protein and DNA repair, and decreased those involved in sulfate reduction, lactate oxidation and protein synthesis. A gene coexpression network analysis revealed complicated network interactions among differentially expressed genes, and suggested possible importance of several hypothetical genes in H{sub 2}O{sub 2} stress. Also, most of the genes in PerR and Fur regulons were highly induced, and the abundance of a Fur regulon protein increased. Mutant analysis suggested that PerR and Fur are functionally overlapped in response to stresses induced by H{sub 2}O{sub 2} and reaction products, and the upregulation of thioredoxin-dependent reduction genes was independent of PerR or Fur. It appears that induction of those stress response genes could contribute to the increased resistance of deletion mutants to H{sub 2}O{sub 2}-induced stresses. In addition, a conceptual cellular model of D. vulgaris responses to H{sub 2}O{sub 2} stress was constructed to illustrate that this bacterium may employ a complicated molecular mechanism to defend against the H{sub 2}O{sub 2}-induced stresses.

  13. 21 CFR 178.1005 - Hydrogen peroxide solution.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Hydrogen peroxide solution. 178.1005 Section 178... Growth of Microorganisms § 178.1005 Hydrogen peroxide solution. Hydrogen peroxide solution identified in...)(1) of this section. (a) Identity. For the purpose of this section, hydrogen peroxide solution is...

  14. ORGANIC AND INORGANIC ARSENICALS SENSITIZE HUMAN BRONCHIAL EPITHELIAL CELLS TO HYDROGEN PEROXIDE-INDUCED DNA DAMAGE

    EPA Science Inventory

    The lungs are a target organ for arsenic carcinogenesis, however, its mechanism of action remains unclear. Furthermore, it has been suggested that inorganic arsenic (iAs) can potentiate DNA damage induced by other agents. Once inside the human body iAs generally undergoes two ...

  15. Ethylene and hydrogen peroxide are involved in brassinosteroid-induced salt tolerance in tomato

    PubMed Central

    Zhu, Tong; Deng, Xingguang; Zhou, Xue; Zhu, Lisha; Zou, Lijuan; Li, Pengxu; Zhang, Dawei; Lin, Honghui

    2016-01-01

    Crosstalk between phytohormone pathways is essential in plant growth, development and stress responses. Brassinosteroids (BRs) and ethylene are both pivotal plant growth regulators, and the interaction between these two phytohormones in the tomato response to salt stress is still unclear. Here, we explored the mechanism by which BRs affect ethylene biosynthesis and signaling in tomato seedlings under salt stress. The activity of 1-aminocyclopropane-1-carboxylate synthase (ACS), an ethylene synthesis enzyme, and the ethylene signaling pathway were activated in plants pretreated with BRs. Scavenging of ethylene production or silencing of ethylene signaling components inhibited BR-induced salt tolerance and blocked BR-induced activities of several antioxidant enzymes. Previous studies have reported that BRs can induce plant tolerance to a variety of environmental stimuli by triggering the generation of H2O2 as a signaling molecule. We also found that H2O2 might be involved in the crosstalk between BRs and ethylene in the tomato response to salt stress. Simultaneously, BR-induced ethylene production was partially blocked by pretreated with a reactive oxygen species scavenger or synthesis inhibitor. These results strongly demonstrated that ethylene and H2O2 play important roles in BR-dependent induction of plant salt stress tolerance. Furthermore, we also investigated the relationship between BR signaling and ethylene signaling pathways in plant processes responding to salt stress. PMID:27739520

  16. Centella asiatica extracts modulate hydrogen peroxide-induced senescence in human dermal fibroblasts.

    PubMed

    Kim, Young Joo; Cha, Hwa Jun; Nam, Ki Ho; Yoon, Yeongmin; Lee, Hyunjin; An, Sungkwan

    2011-12-01

    Centella asiatica (C. asiatica) is a pharmacological plant in South Asia. It has been demonstrated that C. asiatica extracts containing various pentacyclic triterpenes exert healing effects, especially wound healing and collagen synthesis in skin. However, there are few studies on the effect of C. asiatica extracts on stress-induced premature senescence (SIPS). To determine whether H(2) O(2) -induced senescence is affected by C. asiatica extracts, we performed senescence analysis on cultured human dermal fibroblasts (HDFs). We also analysed whole gene expression level using microarrays and showed that 39 mRNAs are differentially expressed in H(2) O(2) -induced HDFs with and without treatment with C. asiatica extracts. These genes regulate apoptosis, gene silencing, cell growth, transcription, senescence, DNA replication and the spindle checkpoint. Differential expression of FOXM1, E2F2, MCM2, GDF15 and BHLHB2 was confirmed using semi-quantitative PCR. In addition, C. asiatica extracts rescued the H(2) O(2) -induced repression of replication in HDFs. Therefore, the findings presented here suggest that C. asiatica extracts might regulate SIPS by preventing repression of DNA replication and mitosis-related gene expression. PMID:22092576

  17. Implication of mitochondrial hydrogen peroxide generation in ceramide-induced apoptosis.

    PubMed

    Quillet-Mary, A; Jaffrézou, J P; Mansat, V; Bordier, C; Naval, J; Laurent, G

    1997-08-22

    The key events implicated in ceramide-triggered apoptosis remain unknown. In this study we show that 25 microM C6-ceramide induced significant H2O2 production within 60 min, which increased up to 180 min in human myeloid leukemia U937 cells. Inactive analogue dihydro-C6-ceramide had no effect. Furthermore, no H2O2 production was observed in C6-ceramide-treated U937 rho degrees cells, which are mitochondrial respiration-deficient. We also present evidence that ceramide-induced activation of the transcription factors NF-kappaB and AP-1 is mediated by mitochondrial derived reactive oxygen species. Both H2O2 production, transcription factor activation as well as apoptosis could be inhibited by rotenone and thenoyltrifluoroacetone (specific mitochondrial complexes I and II inhibitors) and antioxidants, N-acetylcysteine and pyrrolidine dithiocarbamate. These effects could be potentiated by antimycin A (specific complex III mitochondrial inhibitor). H2O2 production was also inhibitable by ruthenium red, suggesting a role of mitochondrial calcium homeostasis alterations in ceramide-induced oxidative stress. Finally, C6-ceramide had no influence on mitochondrial membrane potential within the first 6 h. Altogether, our study points to reactive oxygen species, generated at the ubiquinone site of the mitochondrial respiratory chain, as an early major mediator in ceramide-induced apoptosis. PMID:9261153

  18. Anethole prevents hydrogen peroxide-induced apoptosis and collagen metabolism alterations in human skin fibroblasts.

    PubMed

    Galicka, Anna; Krętowski, Rafał; Nazaruk, Jolanta; Cechowska-Pasko, Marzanna

    2014-09-01

    The collagen metabolism alterations triggered by reactive oxygen species are involved in the development of various connective tissue diseases and skin aging. This study was designed to examine whether (E)-anethole possesses a protective effect on H2O2-induced alterations in collagen metabolism as well as whether it can prevent apoptosis in human skin fibroblasts. In cells treated with 300 µM H₂O₂, a decrease in collagen biosynthesis of 54% was observed. Pretreatment of cells with 0.5 µM anethole for 1 h completely prevented this alteration. Changes at the protein level positively correlated with alterations of type I collagen mRNA expression. We have shown that H2O2 caused increase in the activity of MMP-2 and MMP-9 as well as that an increase in MMP-2 activity can contribute to the 8% decrease in the amount of collagen secreted into the medium. The most efficient suppression of these changes was observed in the presence of 0.5 µM of anethole. At 10 µM, in addition to suppression, an inhibitory effect of anethole on MMP-9 activity was documented. Additionally, the 60% H₂O₂-induced decrease in cell viability was suppressed by 1 µM of anethole and a 4-fold increase in cell apoptosis was suppressed by 0.5 µM of anethole. Our results suggest that anethole, which is a small lipophilic and non-toxic molecule with the ability to prevent H₂O₂-induced collagen metabolism alterations and apoptosis in human skin fibroblasts, would prove useful in the development of effective agents in pharmacotherapy of oxidative stress-related skin diseases.

  19. Lentinula edodes (Shiitake) mushroom extract protects against hydrogen peroxide induced cytotoxicity in peripheral blood mononuclear cells.

    PubMed

    Kuppusamy, U R; Chong, Y L; Mahmood, A A; Indran, M; Abdullah, Noorlidah; Vikineswary, S

    2009-04-01

    Lentinula edodes (Berk) Pegler, commonly known as Shiitake mushroom has been used as medicinal food in Asian countries, especially in China and Japan and is believed to possess strong immunomodulatory property. In the present study, the methanolic extract of the fruit bodies of L. edodes was investigated for cytoprotective effect against H2O2-induced cytotoxicity in human peripheral blood mononuclear cells (PBMCs) by measuring the activities of xanthine oxidase (XO) and glutathione peroxidase (GPx) . H2O2 at a concentration of 5 microM caused 50% inhibition of PBMCs viability. The extract improved the PBMC viability and exerted a dose-dependent protection against H2O2-induced cytotoxicity. At 100 microg/ml of extract concentration, the cell viability increased by 60% compared with the PBMCs incubated with H2O2 alone. The extract also inhibited XO activity in PBMC, while showing moderate stimulatory effect on GPx. However, in the presence of H2O2 alone, both the enzyme activities were increased significantly. The GPx activity increased, possibly in response to the increased availability of H2O2 in the cell. When the cells were pretreated with the extract and washed (to remove the extract) prior to the addition of H2O2, the GPx and XO activities as well as the cell viability were comparable to those when incubated with the extract alone. Thus, it is suggested that one of the possible mechanisms via which L. edodes methanolic extract confers protection against H2O2-induced oxidative stress in PBMC is by inhibiting the superoxide-producing XO and increasing GPx activity which could rapidly inactivate H2O2. PMID:19517993

  20. Requirement of intracellular free thiols for hydrogen peroxide-induced hypertrophy in cardiomyocytes.

    PubMed

    Tanaka, Hiroyuki; Sakurai, Koichi; Takahashi, Kiyoshi; Fujimoto, Yukio

    2003-08-01

    Reactive oxygen species (ROS) are by-products of aerobic metabolism and are implicated in the pathogenesis of several diseases. H(2)O(2) produces oxidative stress and acts as a second messenger in several cell types. We tested whether the effect of H(2)O(2) on cellular events could be altered by changes in the intracellular redox status in a cardiomyocyte cell line. Using flow cytometric measurements, we found that adding H(2)O(2) induced hypertrophy in control cells in a time-dependent manner. Pre-incubation of the cells with buthionine sulfoximine (BSO), an inhibitor of de novo GSH synthesis, induced increase in the number of cells of small sizes by the addition of H(2)O(2) as compared to non-BSO pre-incubated control cells, and exacerbated the decrease in viability. Total thiol and GSH levels in H9c2 cells pre-incubated with BSO were about 75 and 30% of control, respectively, and GSH levels fell to below the limitation of detection after the addition of H(2)O(2), although total thiol levels were not markedly decreased. In the cells pre-incubated with BSO, hypertrophy was not observed by the addition of H(2)O(2) at any level of concentration. N-acetyl-L-cysteine and cysteine not only prevented increase in the number of cells of small sizes caused by H(2)O(2) but also induced hypertrophy in cells pre-incubated with BSO. These results suggest that the intracellular free thiol levels determine whether cell death or hypertrophy occurs in cardiomyocytes in the presence of H(2)O(2). On the other hand, the hypertrophied cells did not become larger by adding H(2)O(2), but had high levels of cellular GSH, suggesting the possibility that the hypertrophied cells have tolerance to oxidative stress.

  1. Chlorella protects against hydrogen peroxide-induced pancreatic β-cell damage.

    PubMed

    Lin, Chia-Yu; Huang, Pei-Jane; Chao, Che-Yi

    2014-12-01

    Oxidative stress has been implicated in the etiology of pancreatic β-cell dysfunction and diabetes. Studies have shown that chlorella could be important in health promotion or disease prevention through its antioxidant capacity. However, whether chlorella has a cytoprotective effect in pancreatic β-cells remains to be elucidated. We investigated the protective effects of chlorella on H2O2-induced oxidative damage in INS-1 (832/13) cells. Chlorella partially restored cell viability after H2O2 toxicity. To further investigate the effects of chlorella on mitochondria function and cellular oxidative stress, we analyzed mitochondria membrane potential, ATP concentrations, and cellular levels of reactive oxygen species (ROS). Chlorella prevented mitochondria disruption and maintained cellular ATP levels after H2O2 toxicity. It also normalized intracellular levels of ROS to that of control in the presence of H2O2. Chlorella protected cells from apoptosis as indicated by less p-Histone and caspase 3 activation. In addition, chlorella not only enhanced glucose-stimulated insulin secretion (GSIS), but also partially restored the reduced GSIS after H2O2 toxicity. Our results suggest that chlorella is effective in amelioration of cellular oxidative stress and destruction, and therefore protects INS-1 (832/13) cells from H2O2-induced apoptosis and increases insulin secretion. Chlorella should be studied for use in the prevention or treatment of diabetes.

  2. Exogenous hydrogen peroxide reversibly inhibits root gravitropism and induces horizontal curvature of primary root during grass pea germination.

    PubMed

    Jiang, Jinglong; Su, Miao; Wang, Liyan; Jiao, Chengjin; Sun, Zhengxi; Cheng, Wei; Li, Fengmin; Wang, Chongying

    2012-04-01

    During germination in distilled water (dH(2)O) on a horizontally positioned Petri dish, emerging primary roots of grass pea (Lathyrus sativus L.) grew perpendicular to the bottom of the Petri dish, due to gravitropism. However, when germinated in exogenous hydrogen peroxide (H(2)O(2)), the primary roots grew parallel to the bottom of the Petri dish and asymmetrically, forming a horizontal curvature. Time-course experiments showed that the effect was strongest when H(2)O(2) was applied prior to the emergence of the primary root. H(2)O(2) failed to induce root curvature when applied post-germination. Dosage studies revealed that the frequency of primary root curvature was significantly enhanced with increased H(2)O(2) concentrations. This curvature could be directly counteracted by dimethylthiourea (DMTU), a scavenger of H(2)O(2), but not by diphenylene iodonium (DPI) and pyridine, inhibitors of H(2)O(2) production. Exogenous H(2)O(2) treatment caused both an increase in the activities of H(2)O(2)-scavenging enzymes [including ascorbate peroxidase (APX: EC 1.11.1.11), catalase (CAT: EC 1.11.1.6) and peroxidase (POD: EC 1.11.1.7)] and a reduction in endogenous H(2)O(2) levels and root vitality. Although grass pea seeds absorbed exogenous H(2)O(2) during seed germination, DAB staining of paraffin sections revealed that exogenous H(2)O(2) only entered the root epidermis and not inner tissues. These data indicated that exogenously applied H(2)O(2) could lead to a reversible loss of the root gravitropic response and a horizontal curvature in primary roots during radicle emergence of the seedling.

  3. High light-induced hydrogen peroxide production in Chlamydomonas reinhardtii is increased by high CO2 availability.

    PubMed

    Roach, Thomas; Na, Chae Sun; Krieger-Liszkay, Anja

    2015-03-01

    The production of reactive oxygen species (ROS) is an unavoidable part of photosynthesis. Stress that accompanies high light levels and low CO2 availability putatively includes enhanced ROS production in the so-called Mehler reaction. Such conditions are thought to encourage O2 to become an electron acceptor at photosystem I, producing the ROS superoxide anion radical (O2·-) and hydrogen peroxide (H2 O2 ). In contrast, here it is shown in Chlamydomonas reinhardtii that CO2 depletion under high light levels lowered cellular H2 O2 production, and that elevated CO2 levels increased H2 O2 production. Using various photosynthetic and mitochondrial mutants of C. reinhardtii, the chloroplast was identified as the main source of elevated H2 O2 production under high CO2 availability. High light levels under low CO2 availability induced photoprotective mechanisms called non-photochemical quenching, or NPQ, including state transitions (qT) and high energy state quenching (qE). The qE-deficient mutant npq4 produced more H2 O2 than wild-type cells under high light levels, although less so under high CO2 availability, whereas it demonstrated equal or greater enzymatic H2 O2 -degrading capacity. The qT-deficient mutant stt7-9 produced the same H2 O2 as wild-type cells under high CO2 availability. Physiological levels of H2 O2 were able to hinder qT and the induction of state 2, providing an explanation for why under high light levels and high CO2 availability wild-type cells behaved like stt7-9 cells stuck in state 1.

  4. High light-induced hydrogen peroxide production in Chlamydomonas reinhardtii is increased by high CO2 availability.

    PubMed

    Roach, Thomas; Na, Chae Sun; Krieger-Liszkay, Anja

    2015-03-01

    The production of reactive oxygen species (ROS) is an unavoidable part of photosynthesis. Stress that accompanies high light levels and low CO2 availability putatively includes enhanced ROS production in the so-called Mehler reaction. Such conditions are thought to encourage O2 to become an electron acceptor at photosystem I, producing the ROS superoxide anion radical (O2·-) and hydrogen peroxide (H2 O2 ). In contrast, here it is shown in Chlamydomonas reinhardtii that CO2 depletion under high light levels lowered cellular H2 O2 production, and that elevated CO2 levels increased H2 O2 production. Using various photosynthetic and mitochondrial mutants of C. reinhardtii, the chloroplast was identified as the main source of elevated H2 O2 production under high CO2 availability. High light levels under low CO2 availability induced photoprotective mechanisms called non-photochemical quenching, or NPQ, including state transitions (qT) and high energy state quenching (qE). The qE-deficient mutant npq4 produced more H2 O2 than wild-type cells under high light levels, although less so under high CO2 availability, whereas it demonstrated equal or greater enzymatic H2 O2 -degrading capacity. The qT-deficient mutant stt7-9 produced the same H2 O2 as wild-type cells under high CO2 availability. Physiological levels of H2 O2 were able to hinder qT and the induction of state 2, providing an explanation for why under high light levels and high CO2 availability wild-type cells behaved like stt7-9 cells stuck in state 1. PMID:25619314

  5. Hydrogen peroxide induced repression of icaADBC transcription and biofilm development in Staphylococcus epidermidis.

    PubMed

    Glynn, Aaron A; O'Donnell, Sinead T; Molony, Diarmuid C; Sheehan, Eoin; McCormack, Damian J; O'Gara, James P

    2009-05-01

    Expression of the icaADBC-encoded polysaccharide intercellular adhesion by Staphylococcus epidermidis promotes biofilm formation and represents an important virulence factor in biomaterial-related infections following orthopedic surgery. Biofilm development by the pathogen can be viewed as a protective reaction to environmental stressors including osmotic stress, thermal stress, and antimicrobial chemotherapy. Oxidative stress, arising from the release of toxic oxygen radicals by polymorphonuclear cells, is encountered by bacteria entering the body perioperatively. Evasion of this and other cell-mediated immune responses by pathogenic bacteria plays an important role in the development of chronic biomaterial-related infection. Here we investigated the impact of sublethal oxidative stress induced by H2O2 (<18 mM) on S. epidermidis biofilm formation. S. epidermidis grown in brain heart infusion (BHI) media supplemented with 5 mM H2O2 or 10 mM H2O2 formed significantly less biofilm (p < 0.01 and p < 0.001, respectively) than bacteria grown in BHI alone. Consistent with this, using reverse transcription-polymerase chain reaction expression of the ica locus was also shown to be reduced by subinhibitory concentrations of H2O2. Furthermore, diminished ica operon expression correlated with increased expression of icaR, which encodes a repressor of icaADBC. Thus, these data suggest that mild oxidative stress downregulates biofilm development by S. epidermidis and may have potential in a therapeutic context.

  6. Protective Effect of Selected Medicinal Plants against Hydrogen Peroxide Induced Oxidative Damage on Biological Substrates

    PubMed Central

    Pai Kotebagilu, Namratha; Reddy Palvai, Vanitha

    2014-01-01

    Oxidative stress is developed due to susceptibility of biological substrates to oxidation by generation of free radicals. In degenerative diseases, oxidative stress level can be reduced by antioxidants which neutralize free radicals. Primary objective of this work was to screen four medicinal plants, namely, Andrographis paniculata, Costus speciosus, Canthium parviflorum, and Abrus precatorius, for their antioxidant property using two biological substrates—RBC and microsomes. The antioxidative ability of three solvent extracts, methanol (100% and 80%) and aqueous leaf extracts, was studied at different concentrations by thiobarbituric acid reactive substances method using Fenton's reagent to induce oxidation in the substrates. The polyphenol and flavonoid content were analyzed to relate with the observed antioxidant effect of the extracts. The phytochemical screening indicated the presence of flavonoids, polyphenols, tannins, and β-carotene in the samples. In microsomes, 80% methanol extract of Canthium and Costus and, in RBC, 80% methanol extract of Costus showed highest inhibition of oxidation and correlated well with the polyphenol and flavonoid content. From the results it can be concluded that antioxidants from medicinal plants are capable of inhibiting oxidation in biological systems, suggesting scope for their use as nutraceuticals. PMID:25436152

  7. Human Umbilical Cord Wharton's Jelly Stem Cell Conditioned Medium Induces Tumoricidal Effects on Lymphoma Cells Through Hydrogen Peroxide Mediation.

    PubMed

    Lin, Hao Daniel; Fong, Chui-Yee; Biswas, Arijit; Choolani, Mahesh; Bongso, Ariff

    2016-09-01

    Several groups have reported that human umbilical cord Wharton's jelly stem cells (hWJSCs) possess unique tumoricidal properties against many cancers. However, the exact mechanisms as to how hWJSCs inhibit tumor growth are not known. Recent evidence suggests that exposure of cancer cells to high hydrogen peroxide (H2 O2 ) levels from H2 O2 -releasing drugs causes their death. We therefore explored whether the tumoricidal effect of hWJSCs on lymphoma cells was mediated via H2 O2 . We first exposed lymphoma cells to six different molecular weight cut-off (MWCO) concentrates of hWJSC-conditioned medium (hWJSC-CM) (3, 5, 10, 30, 50, 100 kDa) for 48 h. Since, the 3 kDa-MWCO concentrate showed the greatest cell inhibition we then investigated whether the tumoricidal effect of the specific 3 kDa-MWCO concentrate on two different lymphoma cell lines (Ramos and Toledo) was mediated via accumulation of H2 O2 . We used a battery of assays (MTT, propidium iodide, mitochondria membrane potential, apoptosis, cell cycle, oxidative stress enzymes, hydrogen peroxide, mitochondrial superoxide, hydroxyl radical, peroxynitrile anion, and lipid peroxidation) to test this mechanism. The hWJSC-CM-3 kDa MWCO concentrate significantly decreased cell viability and mitochondrial membrane potential and increased cell death and apoptosis in both lymphoma cell lines. There were significant increases in superoxide dismutase with concomitant decreases in glutathione peroxidase, catalase, and thioredoxin peroxidase activities. H2 O2 levels, mitochondrial superoxide, hydroxyl radical, peroxynitrile anion, and lipid peroxidation were also significantly increased in both lymphoma cell lines. The results suggested that the hWJSC-CM-3 kDa MWCO concentrate regulates cellular H2 O2 leading to a tumoricidal effect and may thus be a promising anti-lymphoma agent. J. Cell. Biochem. 117: 2045-2055, 2016. © 2016 Wiley Periodicals, Inc. PMID:27392313

  8. Exposure to Hydrogen Peroxide Induces Oxidation and Activation of AMP-activated Protein Kinase*

    PubMed Central

    Zmijewski, Jaroslaw W.; Banerjee, Sami; Bae, Hongbeom; Friggeri, Arnaud; Lazarowski, Eduardo R.; Abraham, Edward

    2010-01-01

    Although metabolic conditions associated with an increased AMP/ATP ratio are primary factors in the activation of 5′-adenosine monophosphate-activated protein kinase (AMPK), a number of recent studies have shown that increased intracellular levels of reactive oxygen species can stimulate AMPK activity, even without a decrease in cellular levels of ATP. We found that exposure of recombinant AMPKαβγ complex or HEK 293 cells to H2O2 was associated with increased kinase activity and also resulted in oxidative modification of AMPK, including S-glutathionylation of the AMPKα and AMPKβ subunits. In experiments using C-terminal truncation mutants of AMPKα (amino acids 1–312), we found that mutation of cysteine 299 to alanine diminished the ability of H2O2 to induce kinase activation, and mutation of cysteine 304 to alanine totally abrogated the enhancing effect of H2O2 on kinase activity. Similar to the results obtained with H2O2-treated HEK 293 cells, activation and S-glutathionylation of the AMPKα subunit were present in the lungs of acatalasemic mice or mice treated with the catalase inhibitor aminotriazole, conditions in which intracellular steady state levels of H2O2 are increased. These results demonstrate that physiologically relevant concentrations of H2O2 can activate AMPK through oxidative modification of the AMPKα subunit. The present findings also imply that AMPK activation, in addition to being a response to alterations in intracellular metabolic pathways, is directly influenced by cellular redox status. PMID:20729205

  9. Process for the production of hydrogen peroxide

    DOEpatents

    Datta, R.; Randhava, S.S.; Tsai, S.P.

    1997-09-02

    An integrated membrane-based process method for producing hydrogen peroxide is provided comprising oxidizing hydrogenated anthraquinones with air bubbles which were created with a porous membrane, and then contacting the oxidized solution with a hydrophilic membrane to produce an organics free, H{sub 2}O{sub 2} laden permeate. 1 fig.

  10. Process for the production of hydrogen peroxide

    DOEpatents

    Datta, Rathin; Randhava, Sarabjit S.; Tsai, Shih-Perng

    1997-01-01

    An integrated membrane-based process method for producing hydrogen peroxide is provided comprising oxidizing hydrogenated anthraquinones with air bubbles which were created with a porous membrane, and then contacting the oxidized solution with a hydrophilic membrane to produce an organics free, H.sub.2 O.sub.2 laden permeate.

  11. Titanium corrosion in alkaline hydrogen peroxide environments

    NASA Astrophysics Data System (ADS)

    Been, Jantje

    1998-12-01

    The corrosion of Grade 2 titanium in alkaline hydrogen peroxide environments has been studied by weight loss corrosion tests, electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR) measurements and potentiodynamic polarography. Calcium ions and wood pulp were investigated as corrosion inhibitors. In alkaline peroxide, the titanium corrosion rate increased with increasing pH, temperature, and hydrogen peroxide concentration. The corrosion controlling mechanism is thought to be the reaction of the oxide with the perhydroxyl ion. No evidence of thermodynamically stable calcium titanate was found in the surface film of test coupons exposed to calcium-inhibited alkaline peroxide solutions. Calcium inhibition is probably the result of low local alkali and peroxide concentrations at the metal surface produced by reaction of adsorbed calcium with hydrogen peroxide. It has been shown that the inhibiting effect of calcium is temporary, possibly through an effect of calcium on the chemical and/or physical stability of the surface oxide. Pulp is an effective and stable corrosion inhibitor. Raising the pulp concentration decreased the corrosion rate. The inhibiting effect of pulp may be related to the adsorption and interaction of the pulp fibers with H 2O2, thereby decreasing the peroxide concentration and rendering the solution less corrosive. The presence of both pulp and calcium led to higher corrosion rates than obtained by either one inhibitor alone. Replacement of hydrofluoric acid with alkaline peroxide for pickling of titanium was investigated. Titanium corrosion rates in alkaline peroxide exceeded those obtained in the conventional hydrofluoric acid bath. General corrosion was observed with extensive roughening of the surface giving a dull gray appearance. Preferred dissolution of certain crystallographic planes was investigated through the corrosion of a titanium single crystal. Whereas the overall effect on the corrosion rate was small

  12. Light emission of gold nanoparticles induced by the reaction of bis(2,4,6-trichlorophenyl) oxalate and hydrogen peroxide.

    PubMed

    Cui, Hua; Zhang, Zhi-Feng; Shi, Ming-Juan; Xu, Yang; Wu, Yun-Long

    2005-10-01

    Light emission at approximately 415 nm was observed for gold particles with diameters of 2.6-6.0 nm dispersed in a solution containing bis(2,4,6-trichlorophenyl) oxalate and hydrogen peroxide. It was found that the light intensity was independent of the protecting reagents of the gold nanoparticles with similar size, the light intensity with gold nanoparticles of 5.0 and 6.0 nm in diameter was stronger than that with gold nanoparticles of 2.6 and 2.8 nm in diameter, and the light intensity increased linearly with the concentration of the gold nanoparticles using 6.0-nm gold nanoparticles. The gold nanoparticles were identified as emitting species, and the quantum yield was determined to be (2.8 +/- 0.3) x 10(-5) using 6.0-nm gold nanoparticles. The light emission is suggested to involve a sequence of steps: the oxidation reaction of bis(2,4,6-trichlorophenyl) oxalate with hydrogen peroxide yielding an energy-rich intermediate 1,2-dioxetanedione, the energy transfer from this intermediate to gold nanoparticles, and the radiative relaxation of the as-formed exited-state gold nanoparticles. The observed luminescence is expected to find applications in the field of bioanalysis owing to the excellent biocompatibility and relatively high stability of gold nanoparticles. PMID:16194106

  13. Catalyst Development for Hydrogen Peroxide Rocket Engines

    NASA Technical Reports Server (NTRS)

    Morlan, P. W.; Wu, P.-K.; Ruttle, D. W.; Fuller, R. P.; Nejad, A. S.; Anderson, W. E.

    1999-01-01

    The development of various catalysts of hydrogen peroxide was conducted for the applications of liquid rocket engines. The catalyst development includes silver screen technology, solid catalyst technology, and homogeneous catalyst technology. The silver screen technology development was performed with 85% (by weight) hydrogen peroxide. The results of this investigation were used as the basis for the catalyst design of a pressure-fed liquid-fueled upper stage engine. Both silver-plated nickel 200 screens and pure silver screens were used as the active metal catalyst during the investigation, The data indicate that a high decomposition efficiency (greater than 90%) of 85% hydrogen peroxide can be achieved at a bed loading of 0.5 lbm/sq in/sec with both pure silver and silver plated screens. Samarium oxide coating, however, was found to retard the decomposition process and the catalyst bed was flooded at lower bed loading. A throughput of 200 lbm of hydrogen peroxide (1000 second run time) was tested to evaluate the catalyst aging issue and performance degradation was observed starting at approximately 400 seconds. Catalyst beds of 3.5 inch in diameter was fabricated using the same configuration for a 1,000-lbf rocket engine. High decomposition efficiency was obtained with a low pressure drop across the bed. Solid catalyst using precious metal was also developed for the decomposition of hydrogen peroxide from 85% to 98% by weight. Preliminary results show that the catalyst has a strong reactivity even after 15 minutes of peroxide decomposition. The development effort also includes the homogeneous catalyst technology. Various non-toxic catalysts were evaluated with 98% peroxide and hydrocarbon fuels. The results of open cup drop tests indicate an ignition delay around 11 ms.

  14. Mechanism of toxicity of hydrogen peroxide

    SciTech Connect

    Imlay, J.A.

    1987-01-01

    We examined the capacity of hydrogen peroxide to injure E. coli. Externally applied hydrogen peroxide rapidly permeates the bacterial cell and causes at least two classes of potentially lethal damage. These classes were initially distinguished by the kinetics of their production. Additional distinctions have been made regarding the chemistry of cell injury and the details of the cell response. One class of cell damage consists of DNA lesions; if unrepaired, mode one killing results. Hydrogen peroxide does not directly attack the DNA. Instead, ferrous iron reduces the peroxide to generate a hydroxyl-radical-like species, which acts as a DNA oxidant. The peculiar kinetics of mode-one killing may reflect an high reaction rate between this radical and peroxide itself. Interestingly, NADH may chemically reduce ferric iron in order to start and maintain the sequence of redox reactions. The target of the other class of cell damage is unknown. This damage, unlike that associated with mode-one killing, does not rely upon Fenton chemistry. Scavenging enzymes, such as catalase and superoxide dismutase, contribute to resisting oxidative stress. Increases in catalase titer accelerate detoxification of peroxide and are responsible for the protective effects of oxyR induction. When oxidants elude this defense and nick DNA, a variety of enzymes-exonuclease III, endonuclease IV, and DNA polymerase I-repair the damage.

  15. Hydrogen Peroxide - Material Compatibility Studied by Microcalorimetry

    NASA Technical Reports Server (NTRS)

    Homung, Steven D.; Davis, Dennis D.; Baker, David; Popp, Christopher G.

    2003-01-01

    Environmental and toxicity concerns with current hypergolic propellants have led to a renewed interest in propellant grade hydrogen peroxide (HP) for propellant applications. Storability and stability has always been an issue with HP. Contamination or contact of HP with metallic surfaces may cause decomposition, which can result in the evolution of heat and gas leading to increased pressure or thermal hazards. The NASA Johnson Space Center White Sands Test Facility has developed a technique to monitor the decompositions of hydrogen peroxide at temperatures ranging from 25 to 60 C. Using isothermal microcalorimetry we have measured decomposition rates at the picomole/s/g level showing the catalytic effects of materials of construction. In this paper we will present the results of testing with Class 1 and 2 materials in 90 percent hydrogen peroxide.

  16. [Hydrogen peroxide inhibits acetylcholinesterase of myometrium sarcolemma].

    PubMed

    Danylovych, Iu V

    2009-01-01

    The action of hydrogen peroxide on acetylcholinesterase enzymatic activity in myometrium sarcolemma fraction is investigated. Hydrogen peroxide (0.1-26 microM), depending on the concentration, suppressed the activity. Acetylcholinesterase proved to be highly sensitive to the action of H2O2, making Ki = 2.4 +/- 0.4 microM, nH = 0.65 +/- 0.08 (n = 4-5). It is established, that hydrogen peroxide in the range of 1.6 - 6.4 microM essentially reduce V(0,max) and K(M). In the presence of dithiothreitole (a reducer of SH-groups of the membrane surface) the investigated substance effect considerably decreased.

  17. Effects of methanolic extract form Fuzhuan brick-tea on hydrogen peroxide-induced oxidative stress in human intestinal epithelial adenocarcinoma Caco-2 cells.

    PubMed

    Song, Jia-Le; Gao, Yang

    2014-03-01

    The present study investigated the protective effect of methanolic extract from Fuzhuan brick‑tea (FME) on hydrogen peroxide (H2O2)‑induced oxidative stress in the human intestinal epithelial adenocarcinoma cell line Caco‑2. Caco‑2 cells were pretreated with different concentrations (50, 100 and 200 µg/ml) of FME for 2 h and then exposed to H2O2 (1 mM) for 6 h. FME did not exhibit a significant cytotoxic effect and increased the cell viability following H2O2 treatment by decreasing lipid peroxidation in Caco‑2 cells. To investigate the protective effect of FME on H2O2‑induced oxidative stress in Caco‑2 cells, the levels of intracellular glutathione (GSH) and the activity of the endogenous antioxidant enzymes catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH‑px) and glutathione S‑transferase (GST), were determined. FME significantly increased the level of GSH and the activity of antioxidant enzymes. The results from the present study demonstrated that FME has a protective effect on H2O2‑induced oxidative damage in Caco‑2 cells through the inhibition of lipid peroxidation and the increase in the activity of antioxidant enzymes. In addition, FME reduced the H2O2‑induced expression of interleukin‑8 at both the mRNA and protein levels in Caco‑2 cells.

  18. Probing skin interaction with hydrogen peroxide using diffuse reflectance spectroscopy

    NASA Astrophysics Data System (ADS)

    Zonios, George; Dimou, Aikaterini; Galaris, Dimitrios

    2008-01-01

    Hydrogen peroxide is an important oxidizing agent in biological systems. In dermatology, it is frequently used as topical antiseptic, it has a haemostatic function, it can cause skin blanching, and it can facilitate skin tanning. In this work, we investigated skin interaction with hydrogen peroxide, non-invasively, using diffuse reflectance spectroscopy. We observed transient changes in the oxyhaemoglobin and deoxyhaemoglobin concentrations as a result of topical application of dilute H2O2 solutions to the skin, with changes in deoxyhaemoglobin concentration being more pronounced. Furthermore, we did not observe any appreciable changes in melanin absorption properties as well as in the skin scattering properties. We also found no evidence for production of oxidized haemoglobin forms. Our observations are consistent with an at least partial decomposition of hydrogen peroxide within the stratum corneum and epidermis, with the resulting oxygen and/or remaining hydrogen peroxide inducing vasoconstriction to dermal blood vessels and increasing haemoglobin oxygen saturation. An assessment of the effects of topical application of hydrogen peroxide to the skin may serve as the basis for the development of non-invasive techniques to measure skin antioxidant capacity and also may shed light onto skin related disorders such as vitiligo.

  19. Improvement of adventitious root formation in flax using hydrogen peroxide.

    PubMed

    Takáč, Tomáš; Obert, Bohuš; Rolčík, Jakub; Šamaj, Jozef

    2016-09-25

    Flax (Linum usitatissimum L.) is an important crop for the production of oil and fiber. In vitro manipulations of flax are used for genetic improvement and breeding while improvements in adventitious root formation are important for biotechnological programs focused on regeneration and vegetative propagation of genetically valuable plant material. Additionally, flax hypocotyl segments possess outstanding morphogenetic capacity, thus providing a useful model for the investigation of flax developmental processes. Here, we investigated the crosstalk between hydrogen peroxide and auxin with respect to reprogramming flax hypocotyl cells for root morphogenetic development. Exogenous auxin induced the robust formation of adventitious roots from flax hypocotyl segments while the addition of hydrogen peroxide further enhanced this process. The levels of endogenous auxin (indole-3-acetic acid; IAA) were positively correlated with increased root formation in response to exogenous auxin (1-Naphthaleneacetic acid; NAA). Histochemical staining of the hypocotyl segments revealed that hydrogen peroxide and peroxidase, but not superoxide, were positively correlated with root formation. Measurements of antioxidant enzyme activities showed that endogenous levels of hydrogen peroxide were controlled by peroxidases during root formation from hypocotyl segments. In conclusion, hydrogen peroxide positively affected flax adventitious root formation by regulating the endogenous auxin levels. Consequently, this agent can be applied to increase flax regeneration capacity for biotechnological purposes such as improved plant rooting. PMID:26921706

  20. Improvement of adventitious root formation in flax using hydrogen peroxide.

    PubMed

    Takáč, Tomáš; Obert, Bohuš; Rolčík, Jakub; Šamaj, Jozef

    2016-09-25

    Flax (Linum usitatissimum L.) is an important crop for the production of oil and fiber. In vitro manipulations of flax are used for genetic improvement and breeding while improvements in adventitious root formation are important for biotechnological programs focused on regeneration and vegetative propagation of genetically valuable plant material. Additionally, flax hypocotyl segments possess outstanding morphogenetic capacity, thus providing a useful model for the investigation of flax developmental processes. Here, we investigated the crosstalk between hydrogen peroxide and auxin with respect to reprogramming flax hypocotyl cells for root morphogenetic development. Exogenous auxin induced the robust formation of adventitious roots from flax hypocotyl segments while the addition of hydrogen peroxide further enhanced this process. The levels of endogenous auxin (indole-3-acetic acid; IAA) were positively correlated with increased root formation in response to exogenous auxin (1-Naphthaleneacetic acid; NAA). Histochemical staining of the hypocotyl segments revealed that hydrogen peroxide and peroxidase, but not superoxide, were positively correlated with root formation. Measurements of antioxidant enzyme activities showed that endogenous levels of hydrogen peroxide were controlled by peroxidases during root formation from hypocotyl segments. In conclusion, hydrogen peroxide positively affected flax adventitious root formation by regulating the endogenous auxin levels. Consequently, this agent can be applied to increase flax regeneration capacity for biotechnological purposes such as improved plant rooting.

  1. PED/PEA-15 Inhibits Hydrogen Peroxide-Induced Apoptosis in Ins-1E Pancreatic Beta-Cells via PLD-1

    PubMed Central

    Raciti, Gregory Alexander; Zatterale, Federica; Nigro, Cecilia; Mirra, Paola; Falco, Roberta; Ulianich, Luca; Di Jeso, Bruno; Formisano, Pietro; Miele, Claudia; Beguinot, Francesco

    2014-01-01

    The small scaffold protein PED/PEA-15 is involved in several different physiologic and pathologic processes, such as cell proliferation and survival, diabetes and cancer. PED/PEA-15 exerts an anti-apoptotic function due to its ability to interfere with both extrinsic and intrinsic apoptotic pathways in different cell types. Recent evidence shows that mice overexpressing PED/PEA-15 present larger pancreatic islets and increased beta-cells mass. In the present work we investigated PED/PEA-15 role in hydrogen peroxide-induced apoptosis in Ins-1E beta-cells. In pancreatic islets isolated from TgPED/PEA-15 mice hydrogen peroxide-induced DNA fragmentation was lower compared to WT islets. TUNEL analysis showed that PED/PEA-15 overexpression increases the viability of Ins-1E beta-cells and enhances their resistance to apoptosis induced by hydrogen peroxide exposure. The activity of caspase-3 and the cleavage of PARP-1 were markedly reduced in Ins-1E cells overexpressing PED/PEA-15 (Ins-1EPED/PEA-15). In parallel, we observed a decrease of the mRNA levels of pro-apoptotic genes Bcl-xS and Bad. In contrast, the expression of the anti-apoptotic gene Bcl-xL was enhanced. Accordingly, DNA fragmentation was higher in control cells compared to Ins-1EPED/PEA-15 cells. Interestingly, the preincubation with propranolol, an inhibitor of the pathway of PLD-1, a known interactor of PED/PEA-15, responsible for its deleterious effects on glucose tolerance, abolishes the antiapoptotic effects of PED/PEA-15 overexpression in Ins-1E beta-cells. The same results have been obtained by inhibiting PED/PEA-15 interaction with PLD-1 in Ins-1EPED/PEA-15. These results show that PED/PEA-15 overexpression is sufficient to block hydrogen peroxide-induced apoptosis in Ins-1E cells through a PLD-1 mediated mechanism. PMID:25489735

  2. Hydrogen Peroxide Induced Changes in Energy Status and Respiration Metabolism of Harvested Longan Fruit in Relation to Pericarp Browning.

    PubMed

    Lin, Yi-Xiong; Lin, Yi-Fen; Chen, Yi-Hui; Wang, Hui; Shi, John; Lin, He-Tong

    2016-06-01

    Energy status and respiration metabolism of "Fuyan" longan fruit treated by hydrogen peroxide (H2O2) and their relationship to pericarp browning were studied. The results displayed that H2O2 significantly increased the respiration rate, increased activities of respiratory terminal oxidases like cytochrome C oxidase (CCO) and ascorbic acid oxidase (AAO), decreased NAD kinase activity, maintained lower contents of NADP and NADPH as well as higher amounts of NAD and NADH, and accelerated the decrease of energy charge. These results gave convincing evidence that the treatment of H2O2 for accelerating longan pericarp browning was due to an increase of energy deficiency, an increase of respiratory metabolic pathways of Embden-Meyerhof pathway (EMP) and tricarboxylic acid (TCA) cycle, a decrease of pentose phosphate pathway (PPP) of respiratory pathway, and an increase of activities of respiratory terminal oxidases like CCO and AAO. PMID:27213701

  3. Hydrogen Peroxide Induced Changes in Energy Status and Respiration Metabolism of Harvested Longan Fruit in Relation to Pericarp Browning.

    PubMed

    Lin, Yi-Xiong; Lin, Yi-Fen; Chen, Yi-Hui; Wang, Hui; Shi, John; Lin, He-Tong

    2016-06-01

    Energy status and respiration metabolism of "Fuyan" longan fruit treated by hydrogen peroxide (H2O2) and their relationship to pericarp browning were studied. The results displayed that H2O2 significantly increased the respiration rate, increased activities of respiratory terminal oxidases like cytochrome C oxidase (CCO) and ascorbic acid oxidase (AAO), decreased NAD kinase activity, maintained lower contents of NADP and NADPH as well as higher amounts of NAD and NADH, and accelerated the decrease of energy charge. These results gave convincing evidence that the treatment of H2O2 for accelerating longan pericarp browning was due to an increase of energy deficiency, an increase of respiratory metabolic pathways of Embden-Meyerhof pathway (EMP) and tricarboxylic acid (TCA) cycle, a decrease of pentose phosphate pathway (PPP) of respiratory pathway, and an increase of activities of respiratory terminal oxidases like CCO and AAO.

  4. [Rasburicase therapy may cause hydrogen peroxide shock].

    PubMed

    Góth, László

    2008-08-24

    Hyperuricemia contributes to the pathomechanism of diseases such as renal failure, gout, tumor lysis syndrome and metabolic syndrome. Tumor lysis syndrome is a complication of malignancies caused by massive tumor cell lysis due to either spontaneous tumor cell lysis or to different therapies and it may cause hyperuricemia. Recently, for treatment of hyperuricemia the recombinant urate oxidase (rasburicase) therapy has been used. This enzyme converts uric acid with high affinity into soluble allantoin which is eliminated by the kidneys. In this reaction high concentration of hydrogen peroxide is generated. This hydrogen peroxide could cause hemolysis and especially methemoglobin formation, in case of glucose-6-phosphate-dehydrogenase and catalase deficiencies. Therefore it is recommended that these enzymes are determined before therapy. For monitoring of rasburicase therapy the determination of serum uric acid concentration is used. More than 95 per cent of Hungarian clinical laboratories are using the uricate oxidase/peroxidase reactions and hydrogen peroxide measurements in the uric acid assays. These assays may be interfered by ascorbic acid and hydrogen peroxide which is generated by rasburicase either in vivo or in vitro. PMID:18708312

  5. Stabilization of native amyloid β-protein oligomers by Copper and Hydrogen peroxide Induced Cross-linking of Unmodified Proteins (CHICUP).

    PubMed

    Williams, Thomas L; Serpell, Louise C; Urbanc, Brigita

    2016-03-01

    Oligomeric assemblies are postulated to be proximate neurotoxic species in human diseases associated with aberrant protein aggregation. Their heterogeneous and transient nature makes their structural characterization difficult. Size distributions of oligomers of several amyloidogenic proteins, including amyloid β-protein (Aβ) relevant to Alzheimer's disease (AD), have been previously characterized in vitro by photo-induced cross-linking of unmodified proteins (PICUP) followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Due to non-physiological conditions associated with the PICUP chemistry, Aβ oligomers cross-linked by PICUP may not be representative of in vivo conditions. Here, we examine an alternative Copper and Hydrogen peroxide Induced Cross-linking of Unmodified Proteins (CHICUP), which utilizes naturally occurring divalent copper ions and hydrogen peroxide and does not require photo activation. Our results demonstrate that CHICUP and PICUP applied to the two predominant Aβ alloforms, Aβ40 and Aβ42, result in similar oligomer size distributions. Thioflavin T fluorescence data and atomic force microscopy images demonstrate that both CHICUP and PICUP stabilize Aβ oligomers and attenuate fibril formation. Relative to noncross-linked peptides, CHICUP-treated Aβ40 and Aβ42 cause prolonged disruption to biomimetic lipid vesicles. CHICUP-stabilized Aβ oligomers link the amyloid cascade, metal, and oxidative stress hypotheses of AD into a more comprehensive understanding of the molecular basis of AD pathology. Because copper and hydrogen peroxide are elevated in the AD brain, CHICUP-stabilized Aβ oligomers are biologically relevant and should be further explored as a new therapeutic target.

  6. Systems and methods for generation of hydrogen peroxide vapor

    SciTech Connect

    Love, Adam H; Eckels, Joel Del; Vu, Alexander K; Alcaraz, Armando; Reynolds, John G

    2014-12-02

    A system according to one embodiment includes a moisture trap for drying air; at least one of a first container and a second container; and a mechanism for at least one of: bubbling dried air from the moisture trap through a hydrogen peroxide solution in the first container for producing a hydrogen peroxide vapor, and passing dried air from the moisture trap into a headspace above a hydrogen peroxide solution in the second container for producing a hydrogen peroxide vapor. A method according one embodiment includes at least one of bubbling dried air through a hydrogen peroxide solution in a container for producing a first hydrogen peroxide vapor, and passing dried air from the moisture trap into a headspace above the hydrogen peroxide solution in a container for producing a second hydrogen peroxide vapor. Additional systems and methods are also presented.

  7. An upper limit for stratospheric hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Chance, K. V.; Traub, W. A.

    1984-01-01

    It has been postulated that hydrogen peroxide is important in stratospheric chemistry as a reservoir and sink for odd hydrogen species, and for its ability to interconvert them. The present investigation is concerned with an altitude dependent upper limit curve for stratospheric hydrogen peroxide, taking into account an altitude range from 21.5 to 38.0 km for January 23, 1983. The data employed are from balloon flight No. 1316-P, launched from the National Scientific Balloon Facility (NSBF) in Palestine, Texas. The obtained upper limit curve lies substantially below the data reported by Waters et al. (1981), even though the results are from the same latitude and are both wintertime measurements.

  8. Protective effects of Arctium lappa L. roots against hydrogen peroxide-induced cell injury and potential mechanisms in SH-SY5Y cells.

    PubMed

    Tian, Xing; Guo, Li-Ping; Hu, Xiao-Long; Huang, Jin; Fan, Yan-Hua; Ren, Tian-Shu; Zhao, Qing-Chun

    2015-04-01

    Accumulated evidence has shown that excessive reactive oxygen species (ROS) have been implicated in neuronal cell death related with various chronic neurodegenerative disorders. This study was designed to explore neuroprotective effects of ethyl acetate extract of Arctium lappa L. roots (EAL) on hydrogen peroxide (H2O2)-induced cell injury in human SH-SY5Y neuroblastoma cells. The cell viability was significantly decreased after exposure to 200 μM H2O2, whereas pretreatment with different concentrations of EAL attenuated the H2O2-induced cytotoxicity. Hoechst 33342 staining indicated that EAL reversed nuclear condensation in H2O2-treated cells. Meanwhile, TUNEL assay with DAPI staining showed that EAL attenuated apoptosis was induced by H2O2. Pretreatment with EAL also markedly elevated activities of antioxidant enzyme (GSH-Px and SOD), reduced lipid peroxidation (MDA) production, prevented ROS formation, and the decrease of mitochondrial membrane potential. In addition, EAL showed strong radical scavenging ability in 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) assays. Furthermore, EAL inhibited H2O2-induced apoptosis by increases in the Bcl-2/Bax ratio, decreases in cytochrome c release, and attenuation of caspase-3, caspase-9 activities, and expressions. These findings suggest that EAL may be regarded as a potential antioxidant agent and possess potent neuroprotective activity against H2O2-induced injury.

  9. Protective effects of Arctium lappa L. roots against hydrogen peroxide-induced cell injury and potential mechanisms in SH-SY5Y cells.

    PubMed

    Tian, Xing; Guo, Li-Ping; Hu, Xiao-Long; Huang, Jin; Fan, Yan-Hua; Ren, Tian-Shu; Zhao, Qing-Chun

    2015-04-01

    Accumulated evidence has shown that excessive reactive oxygen species (ROS) have been implicated in neuronal cell death related with various chronic neurodegenerative disorders. This study was designed to explore neuroprotective effects of ethyl acetate extract of Arctium lappa L. roots (EAL) on hydrogen peroxide (H2O2)-induced cell injury in human SH-SY5Y neuroblastoma cells. The cell viability was significantly decreased after exposure to 200 μM H2O2, whereas pretreatment with different concentrations of EAL attenuated the H2O2-induced cytotoxicity. Hoechst 33342 staining indicated that EAL reversed nuclear condensation in H2O2-treated cells. Meanwhile, TUNEL assay with DAPI staining showed that EAL attenuated apoptosis was induced by H2O2. Pretreatment with EAL also markedly elevated activities of antioxidant enzyme (GSH-Px and SOD), reduced lipid peroxidation (MDA) production, prevented ROS formation, and the decrease of mitochondrial membrane potential. In addition, EAL showed strong radical scavenging ability in 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) assays. Furthermore, EAL inhibited H2O2-induced apoptosis by increases in the Bcl-2/Bax ratio, decreases in cytochrome c release, and attenuation of caspase-3, caspase-9 activities, and expressions. These findings suggest that EAL may be regarded as a potential antioxidant agent and possess potent neuroprotective activity against H2O2-induced injury. PMID:25352420

  10. Fisetin attenuates hydrogen peroxide-induced cell damage by scavenging reactive oxygen species and activating protective functions of cellular glutathione system.

    PubMed

    Kang, Kyoung Ah; Piao, Mei Jing; Kim, Ki Cheon; Cha, Ji Won; Zheng, Jian; Yao, Cheng Wen; Chae, Sungwook; Hyun, Jin Won

    2014-01-01

    Hydrogen peroxide (H2O2) can induce cell damage by generating reactive oxygen species (ROS), resulting in DNA damage and cell death. The aim of this study is to elucidate the protective effects of fisetin (3,7,3',4',-tetrahydroxy flavone) against H2O2-induced cell damage. Fisetin reduced the level of superoxide anion, hydroxyl radical in cell free system, and intracellular ROS generated by H2O2. Moreover, fisetin protected against H2O2-induced membrane lipid peroxidation, cellular DNA damage, and protein carbonylation, which are the primary cellular outcomes of H2O2 treatment. Furthermore, fisetin increased the level of reduced glutathione (GSH) and expression of glutamate-cysteine ligase catalytic subunit, which is decreased by H2O2. Conversely, a GSH inhibitor abolished the cytoprotective effect of fisetin against H2O2-induced cells damage. Taken together, our results suggest that fisetin protects against H2O2-induced cell damage by inhibiting ROS generation, thereby maintaining the protective role of the cellular GSH system.

  11. 21 CFR 178.1005 - Hydrogen peroxide solution.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Hydrogen peroxide solution. 178.1005 Section 178... SANITIZERS Substances Utilized To Control the Growth of Microorganisms § 178.1005 Hydrogen peroxide solution. Hydrogen peroxide solution identified in this section may be safely used to sterilize polymeric...

  12. 21 CFR 178.1005 - Hydrogen peroxide solution.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Hydrogen peroxide solution. 178.1005 Section 178... SANITIZERS Substances Utilized To Control the Growth of Microorganisms § 178.1005 Hydrogen peroxide solution. Hydrogen peroxide solution identified in this section may be safely used to sterilize polymeric...

  13. 21 CFR 178.1005 - Hydrogen peroxide solution.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Hydrogen peroxide solution. 178.1005 Section 178... SANITIZERS Substances Utilized To Control the Growth of Microorganisms § 178.1005 Hydrogen peroxide solution. Hydrogen peroxide solution identified in this section may be safely used to sterilize polymeric...

  14. 21 CFR 178.1005 - Hydrogen peroxide solution.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Hydrogen peroxide solution. 178.1005 Section 178... SANITIZERS Substances Utilized To Control the Growth of Microorganisms § 178.1005 Hydrogen peroxide solution. Hydrogen peroxide solution identified in this section may be safely used to sterilize polymeric...

  15. Propofol-induced protection of SH-SY5Y cells against hydrogen peroxide is associated with the HO-1 via the ERK pathway.

    PubMed

    Gu, Jing; Chi, Meng; Sun, Xuechao; Wang, Guonian; Li, Mingming; Liu, Li; Li, Xuan

    2013-01-01

    Propofol (2, 6-diisopropylphenol), is an anesthetic and routinely used for the humans sedation during surgery. The potent inducers of phase II detoxifying and antioxidant stress responsive to propofol were investigated. First, a dose of 25-100 µM propofol showed no significant cytotoxicity on SH-SY5Y cells and pre-treatment of SH-SY5Y cells with propofol (25-100 μM) for 8h prevented cell death and maintained cell integrity following exposure to 1 mM hydrogen peroxide by MTT assays. Then, an increase in the generation of ROS following hydrogen peroxide treatment was significantly attenuated by 8 h pre-treatment with propofol. Additionally, the potential roles of ERK, p 38 MAPK and JNK in the regulation of propofol-induced endogenous HO-1 expression in SH-SY5Y cells were estimated by Western blotting assays. Results showed that propofol significantly increased the phosphorylation levels of ERK, p 38 MAPK and JNK and antioxidant stress responsive to propofol was attenuated by the inhibition of ERK signaling biochemical inhibitors. These results suggest that the ERK pathway plays an important role in the regulation of propofol-mediated antioxidant effects in SH-SY5Y cells.

  16. Propofol-Induced Protection of SH-SY5Y Cells against Hydrogen Peroxide Is Associated with the HO-1 via the ERK Pathway

    PubMed Central

    Gu, Jing; Chi, Meng; Sun, Xuechao; Wang, Guonian; Li, Mingming; Liu, Li; Li, Xuan

    2013-01-01

    Propofol (2, 6-diisopropylphenol), is an anesthetic and routinely used for the humans sedation during surgery. The potent inducers of phase II detoxifying and antioxidant stress responsive to propofol were investigated. First, a dose of 25-100 µM propofol showed no significant cytotoxicity on SH-SY5Y cells and pre-treatment of SH-SY5Y cells with propofol (25-100 μM) for 8h prevented cell death and maintained cell integrity following exposure to 1 mM hydrogen peroxide by MTT assays. Then, an increase in the generation of ROS following hydrogen peroxide treatment was significantly attenuated by 8 h pre-treatment with propofol. Additionally, the potential roles of ERK, p 38 MAPK and JNK in the regulation of propofol-induced endogenous HO-1 expression in SH-SY5Y cells were estimated by Western blotting assays. Results showed that propofol significantly increased the phosphorylation levels of ERK, p 38 MAPK and JNK and antioxidant stress responsive to propofol was attenuated by the inhibition of ERK signaling biochemical inhibitors. These results suggest that the ERK pathway plays an important role in the regulation of propofol-mediated antioxidant effects in SH-SY5Y cells. PMID:23569422

  17. Calyxin Y induces hydrogen peroxide-dependent autophagy and apoptosis via JNK activation in human non-small cell lung cancer NCI-H460 cells.

    PubMed

    Zhang, Chao; Yang, Lei; Wang, Xiao-bing; Wang, Jun-song; Geng, Ya-di; Yang, Chang-shui; Kong, Ling-yi

    2013-10-28

    Calyxin Y has been recently isolated from Alpinia katsumadai which has a folk use as an anti-tumor medicine. Calyxin Y induced caspase-dependent cell death in NCI-H460 cells, and concomitantly, provoked cytoprotective autophagy with the upregulation of critical Atg proteins. The cleavage of Atg proteins by caspases acted as a switch between autophagy and apoptosis induced by calyxin Y. Intracellular hydrogen peroxide (H2O2) production was triggered upon exposure to calyxin Y via the induction of autophagy and apoptosis. We provided evidence that activated JNK was upstream effectors controlling both autophagy and apoptosis in response to elevated H2O2. Therefore, our findings demonstrate that calyxin Y serves multiple roles as a promising chemotherapeutic agent that induces H2O2-dependent autophagy and apoptosis via JNK activation. PMID:23811287

  18. Revisiting the mesosome as a novel site of hydrogen peroxide accumulation in Escherichia coli.

    PubMed

    Xin, Li; Lipeng, Yang; Jiaju, Qiao; Hanqing, Feng; Yunhong, Liu; Min, Zhang; Yuxian, Zhang; Hongyu, Li

    2014-10-01

    The major source of endogenous hydrogen peroxide is generally thought to be the respiratory chain of bacteria and mitochondria. In our previous works, mesosome structure was induced in cells during rifampicin effect, and the mesosome formation is always accompanied by excess hydrogen peroxide accumulation in bacterial cells. However, the underlying mechanisms of hydrogen peroxide production and the rationale behind it remain still unknown. Here we report that hydrogen peroxide can specifically accumulate in the mesosome in vitro. Mesosomes were interpreted earlier as artifacts of specific cells under stress through TEM preparation, while, in the current study, mesosomes were shown as intracellular compartments with specific roles and features by using quickly freezing preparation of TEM. Formation of hydrogen peroxide was observed in suspension of mesosomal vesicles by using either a fluorescence-based reporter assay or a histochemical method, respectively. Our investigation provides experimental evidence that mesosomes can be a novel site of hydrogen peroxide accumulation.

  19. Experimental investigation of hydrogen peroxide RF plasmas

    NASA Astrophysics Data System (ADS)

    Barni, R.; Decina, A.; Zanini, S.; D'Orazio, A.; Riccardi, C.

    2016-04-01

    This work reports a detailed experimental study of the plasma properties in low pressure RF discharges in hydrogen peroxide and a comparison with argon under the same operating conditions. H2O2 plasmas have been proposed for sterilization purposes. Electrical properties of the discharge were shown to be similar, as for the RF and DC voltages of the driving electrode. Bulk plasma volume remains stable, concentrated in an almost cylindrical region between the two facing electrodes. It was found that the electron temperature is almost uniform across the plasma and independent of the power level. This is higher than in argon discharges: T e  =  4.6  ±  0.9 eV versus T e  =  3.3  ±  1.1 eV. The plasma density increases almost linearly with the power level and a substantial negative ion component has been ruled out in hydrogen peroxide. Dissociation in the plasma gas phase was revealed by atomic hydrogen and hydroxyl radical emission in the discharge spectra. Emission from hydroxyl and atomic oxygen demonstrates that oxidizing radicals are produced by hydrogen peroxide discharges, revealing its usefulness for plasma processing other than sterilization, for instance to increase polymer film surface energy. On the other hand, argon could be considered as a candidate for the sterilization purposes due to the intense production of UV radiation.

  20. Hydrogen peroxide contributes to the ultraviolet-B (280-315 nm) induced oxidative stress of plant leaves through multiple pathways.

    PubMed

    Czégény, Gyula; Wu, Min; Dér, András; Eriksson, Leif A; Strid, Åke; Hideg, Éva

    2014-06-27

    Solar UV-B (280-315 nm) radiation is a developmental signal in plants but may also cause oxidative stress when combined with other environmental factors. Using computer modeling and in solution experiments we show that UV-B is capable of photosensitizing hydroxyl radical production from hydrogen peroxide. We present evidence that the oxidative effect of UV-B in leaves is at least twofold: (i) it increases cellular hydrogen peroxide concentrations, to a larger extent in pyridoxine antioxidant mutant pdx1.3-1 Arabidopsis and; (ii) is capable of a partial photo-conversion of both 'natural' and 'extra' hydrogen peroxide to hydroxyl radicals. As stress conditions other than UV can increase cellular hydrogen peroxide levels, synergistic deleterious effects of various stresses may be expected already under ambient solar UV-B.

  1. Ybp1 is required for the hydrogen peroxide-induced oxidation of the Yap1 transcription factor.

    PubMed

    Veal, Elizabeth A; Ross, Sarah J; Malakasi, Panagiota; Peacock, Emma; Morgan, Brian A

    2003-08-15

    We describe the characterization of Ybp1, a novel protein, in Saccharomyces cerevisiae, that is required for the oxidative stress response to peroxides. Ybp1 is required for H2O2-induced expression of the antioxidant encoding gene TRX2. Our data indicate that the effects of Ybp1 are mediated through the Yap1 transcription factor. Indeed, Ybp1 forms a stress-induced complex with Yap1 in vivo and stimulates the nuclear accumulation of Yap1 in response to H2O2 but not in response to the thiol-oxidizing agent diamide. The H2O2-induced nuclear accumulation of Yap1 is regulated by the oxidation of specific cysteine residues and is dependent on the thiol peroxidase Gpx3. Our data suggest that Ybp1 is required for the H2O2-induced oxidation of Yap1 and acts in the same pathway as Gpx3. Consequently, Ybp1 represents a novel class of stress regulator of Yap1. These data have important implications for the regulation of protein oxidation and stress responses in eukaryotes. PMID:12743123

  2. BZYX, a novel acetylcholinesterase inhibitor, significantly improved chemicals-induced learning and memory impairments on rodents and protected PC12 cells from apoptosis induced by hydrogen peroxide.

    PubMed

    Zhang, Jing; Zhu, Difeng; Sheng, Rong; Wu, Honghai; Hu, Yongzhou; Wang, Feng; Cai, Tianyu; Yang, Bo; He, Qiaojun

    2009-06-24

    BZYX was designed as a dual-binding-site acetylcholinesterase (AChE) inhibitor and selected from series of indanone derivatives. The present study was designed to examine the cognition-enhanced, anti-cholinesterase, and neuroprotective effects of BZYX. In the passive avoidance performance and radial arm maze, BZYX showed a comparable effect to donepezil and rivastigmine on memory deficits in different stages induced by scopolamine, NaNO(2) and ethanol, respectively. Ellman's assay indicated BZYX exhibited high inhibition on AChE activity. IC(50) values for BZYX: 0.058+/-0.022 microM; donepezil: 0.019+/-0.004 microM; rivastigmine: 3.81+/-2.81 microM; glantamine: 3.01+/-1.85 microM and huperzine A: 0.053+/-0.016 microM. BZYX also presented great neuroprotecive function from apoptosis induced by hydrogen peroxide(H(2)O(2)) in PC12 cells. MTT assay and Annexin V-FITC Apoptosis Detection showed the viability of PC12 cells remarkably decreased with 400 microM H(2)O(2), while it significantly increased when the cells were pretreated with 0.1-1.0 microM BZYX. BZYX pretreatment remarkably reversed the loss of mitochondria membrane potential (DeltaPsim), scavenged reactive oxygen species formation induced by H(2)O(2) and resulted in up-regulation of procaspase3 and xIAP protein level and down-regulation of phosphorylated JNK protein, p53 protein level and cleavage of caspase 3. It is speculated that the mitochondrial pathway, mediated by Bcl-2 family and Mitogen-Activated Protein Kinases (MAPKs), might involved in the neuroprotection of BZYX. These results first demonstrated that BZYX had neuroprotective effects as well as cognition enhancement and acetylcholinesterase inhibition. It is hopeful that BZYX becomes a potential candidate for use in the intervention for neurodegenerative diseases. PMID:19345205

  3. Simultaneous visualization of water and hydrogen peroxide vapor using two-photon laser-induced fluorescence and photofragmentation laser-induced fluorescence.

    PubMed

    Larsson, Kajsa; Johansson, Olof; Aldén, Marcus; Bood, Joakim

    2014-01-01

    A concept based on a combination of photofragmentation laser-induced fluorescence (PF-LIF) and two-photon laser-induced fluorescence (LIF) is for the first time demonstrated for simultaneous detection of hydrogen peroxide (H2O2) and water (H2O) vapor. Water detection is based on two-photon excitation by an injection-locked krypton fluoride (KrF) excimer laser (248.28 nm), which induces broadband fluorescence (400-500 nm) from water. The same laser simultaneously photodissociates H2O2, whereupon the generated OH fragments are probed by LIF after a time delay of typically 50 ns, by a frequency-doubled dye laser (281.91 nm). Experiments in six different H2O2/H2O mixtures of known compositions show that both signals are linearly dependent on respective species concentration. For the H2O2 detection there is a minor interfering signal contribution from OH fragments created by two-photon photodissociation of H2O. Since the PF-LIF signal yield from H2O2 is found to be at least ∼24,000 times higher than the PF-LIF signal yield from H2O at room temperature, this interference is negligible for most H2O/H2O2 mixtures of practical interest. Simultaneous single-shot imaging of both species was demonstrated in a slightly turbulent flow. For single-shot imaging the minimum detectable H2O2 and H2O concentration is 10 ppm and 0.5%, respectively. The proposed measurement concept could be a valuable asset in several areas, for example, in atmospheric and combustion science and research on vapor-phase H2O2 sterilization in the pharmaceutical and aseptic food-packaging industries. PMID:25358016

  4. Synthesis and Protective Effects of Kaempferol-3'-sulfonate on Hydrogen Peroxide-induced injury in Vascular Smooth Muscle Cells.

    PubMed

    Yang, Xinbin; Wang, Qin; Wang, Chunmei; Qin, Xiaolin; Huang, Yu; Zeng, Renquan

    2016-06-01

    A novel water-soluble sulfated derivative, kaempferol-3'-sulfonate acid sodium (KS) with the composition of [C15 H9 O9 SNa]·2.5H2 O, was synthesized and characterized by elemental analysis, IR, (1) H NMR, (13) C NMR, and HRMS. Its protective effects on human vascular smooth muscle cells injured by hydrogen peroxide were evaluated by CCK-8 method, flow cytometry, and Western blotting. The experimental results indicated that the KS can significantly increase cell viability and reduce apoptosis on H2 O2 -injured VSMCs, as well as reverse the effects of H2 O2 on Bcl-2, Bad, and caspase-3 expressions. In addition, LDH leakage, MDA levels, and SOD and GSH activities were also measured with spectrophotometry. The results indicated that the KS acted as antioxidant preventing LDH leakage and MDA production, while increasing intracellular SOD and GSH activities. These findings revealed that KS might potentially serve as an effective antioxidant agent for prevention and treatment of vascular disease caused by H2 O2 -injured VSMCs.

  5. Materials Compatibility in High Test Hydrogen Peroxide

    NASA Technical Reports Server (NTRS)

    Gostowski, Rudy

    1999-01-01

    Previous ratings of the compatibility of high test hydrogen peroxide (HTP) with materials are not adequate for current needs. The goal of this work was to develop a new scheme of evaluation of compatibility of HTP with various materials. Procedures were developed to enrich commercially available hydrogen peroxide to 90% concentration and to assay the product. Reactivity testing, accelerated aging of materials and calorimetry studies were done on HTP with representative metallic and non-metallic materials. It was found that accelerated aging followed by concentration determination using refractive index effectively discriminated between different Class 2 metallic materials. Preliminary experiments using Differential Scanning Calorimetry (DSC) suggest that a calorimetry experiment is the most sensitive means to assay the compatibility of HTP with materials.

  6. Asymmetric Epoxidation Using Hydrogen Peroxide as Oxidant.

    PubMed

    Wang, Chuan; Yamamoto, Hisashi

    2015-10-01

    Asymmetric epoxidation is one of the most important transformations in organic synthesis. Although tremendous progress was achieved in this field in the 1980s and 1990s, it is still desirable from both economical and ecological views to develop environmentally friendly catalytic epoxidation with a broad substrate scope. Hydrogen peroxide is a safe and cheap oxidant, which is easy to handle and generates water as the sole byproduct. Therefore, asymmetric epoxidation of olefins using hydrogen peroxide as oxidant has been a very active research field and has been investigated by many research groups in recent years. In this review, the exciting very recent developments of this rapidly growing area are surveyed and organized according to the catalyst systems.

  7. Antioxidative effects of fermented sesame sauce against hydrogen peroxide-induced oxidative damage in LLC-PK1 porcine renal tubule cells

    PubMed Central

    Song, Jia-Le; Choi, Jung-Ho; Seo, Jae-Hoon; Kil, Jeung-Ha

    2014-01-01

    BACKGROUND/OBJECTIVES This study was performed to investigate the in vitro antioxidant and cytoprotective effects of fermented sesame sauce (FSeS) against hydrogen peroxide (H2O2)-induced oxidative damage in renal proximal tubule LLC-PK1 cells. MATERIALS/METHODS 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical (•OH), and H2O2 scavenging assay was used to evaluate the in vitro antioxidant activity of FSeS. To investigate the cytoprotective effect of FSeS against H2O2-induced oxidative damage in LLC-PK1 cells, the cellular levels of reactive oxygen species (ROS), lipid peroxidation, and endogenous antioxidant enzymes including catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-px) were measured. RESULTS The ability of FSeS to scavenge DPPH, •OH and H2O2 was greater than that of FSS and AHSS. FSeS also significantly inhibited H2O2-induced (500 µM) oxidative damage in the LLC-PK1 cells compared to FSS and AHSS (P < 0.05). Following treatment with 100 µg/mL of FSeS and FSS to prevent H2O2-induced oxidation, cell viability increased from 56.7% (control) to 83.7% and 75.6%, respectively. However, AHSS was not able to reduce H2O2-induced cell damage (viability of the AHSS-treated cells was 54.6%). FSeS more effectively suppressed H2O2-induced ROS generation and lipid peroxidation compared to FSS and AHSS (P < 0.05). Compared to the other sauces, FSeS also significantly increased cellular CAT, SOD, and GSH-px activities and mRNA expression (P < 0.05). CONCULUSIONS These results from the present study suggest that FSeS is an effective radical scavenger and protects against H2O2-induced oxidative damage in LLC-PK1 cells by reducing ROS levels, inhibiting lipid peroxidation, and stimulating antioxidant enzyme activity. PMID:24741396

  8. Dietary spices protect against hydrogen peroxide-induced DNA damage and inhibit nicotine-induced cancer cell migration.

    PubMed

    Jayakumar, R; Kanthimathi, M S

    2012-10-01

    Spices are rich sources of antioxidants due to the presence of phenols and flavonoids. In this study, the DNA protecting activity and inhibition of nicotine-induced cancer cell migration of 9 spices were analysed. Murine fibroblasts (3T3-L1) and human breast cancer (MCF-7) cells were pre-treated with spice extracts and then exposed to H₂O₂ and nicotine. The comet assay was used to analyse the DNA damage. Among the 9 spices, ginger, at 50 μg/ml protected against 68% of DNA damage in 3T3-L1 cells. Caraway, cumin and fennel showed statistically significant (p<0.05) DNA protecting activity. Treatment of MCF-7 cells with nicotine induced cell migration, whereas pre-treatment with spices reduced this migration. Pepper, long pepper and ginger exhibited a high rate of inhibition of cell migration. The results of this study prove that spices protect DNA and inhibit cancer cell migration. PMID:25005983

  9. Nelumbo nucifera leaves protect hydrogen peroxide-induced hepatic damage via antioxidant enzymes and HO-1/Nrf2 activation.

    PubMed

    Je, Jae-Young; Lee, Da-Bin

    2015-06-01

    Naturally occurring phenolic compounds are widely found in plants. Here, the phenolic composition and hepatoprotective effect of the butanolic extract (BE) from Nelumbo nucifera leaves against H2O2-induced hepatic damage in cultured hepatocytes were investigated. BE showed high total phenol and flavonoid contents, and major phenolic compounds are quercetin, catechin, ferulic acid, rutin, and protocatechuic acid by HPLC analysis. BE effectively scavenged 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis(3-ethylbenzthiazoline)-6-sulfonic acid (ABTS) cation radicals (IC50 values of 5.21 μg mL(-1) for DPPH and 6.22 μg mL(-1) for ABTS(+)) and showed strong reducing power. Pretreatment of BE prior to 650 μM H2O2 exposure markedly increased cell viability and suppressed H2O2-induced intracellular reactive oxygen species generation and AAPH-induced cell membrane lipid peroxidation. In addition, BE up-regulated intracellular glutathione levels under normal and oxidative stress conditions. Notably, the hepatoprotective effect of BE was directly correlated with the increased expression of superoxide dismutase-1 (SOD-1) by 0.62-fold, catalase (CAT) by 0.42-fold, and heme oxygenase-1 (HO-1) by 2.4-fold. Pretreatment of BE also increased the nuclear accumulation of Nrf2 by 8.1-fold indicating that increased SOD-1, CAT, and HO-1 expressions are Nrf2-mediated. PMID:25962859

  10. Prevention of hydrogen peroxide-induced red blood cells lysis by Ilex paraguariensis aqueous extract: participation of phenolic and xanthine compounds.

    PubMed

    Peralta, Ignacio N; Cogoi, Laura; Filip, Rosana; Anesini, Claudia

    2013-02-01

    The fresh leaves and stems of Ilex paraguariensis (Aquifoliaceae) are employed to prepare the commercial product used in North-eastern Argentina, Southern Brazil and Eastern Paraguay named yerba maté. The presence of polyphenols and xanthines, which present antioxidant activity, has been described in I. paraguariensis. In living organism, reactive oxygen species can cause tissue damage affecting erythrocyte membranes leading to hemolysis. The aim of this work was to evaluate the protective effect of an aqueous extract of I. paraguariensis (green leaves) on the hemolysis of red blood cells induced by hydrogen peroxide and to correlate this activity with the enzymatic activity related to hydrogen peroxide metabolism. The antioxidant activity of chlorogenic acid and caffeine was also analysed to evaluate their contribution to the activity of the crude extract. The extract as well as the isolated compounds protected red blood cells from hemolysis. This effect was related to a catalase-like activity. This study could contribute to the knowledge of the antioxidant activity of I. paraguariensis in view of the great quantities of yerba maté consumed by the population.

  11. Zingerone protects against stannous chloride-induced and hydrogen peroxide-induced oxidative DNA damage in vitro.

    PubMed

    Rajan, Iyappan; Narayanan, Nithya; Rabindran, Remitha; Jayasree, P R; Manish Kumar, P R

    2013-12-01

    In this paper, we report the dose-dependent antioxidant activity and DNA protective effects of zingerone. At 500 μg/mL, the DPPH radical scavenging activity of zingerone and ascorbic acid as a standard was found to be 86.7 and 94.2 % respectively. At the same concentration, zingerone also showed significant reducing power (absorbance 0.471) compared to that of ascorbic acid (absorbance 0.394). The in vitro toxicity of stannous chloride (SnCl2) was evaluated using genomic and plasmid DNA. SnCl2-induced degradation of genomic DNA was found to occur at a concentration of 0.8 mM onwards with complete degradation at 1.02 mM and above. In the case of plasmid DNA, conversion of supercoiled DNA into the open circular form indicative of DNA nicking activity was observed at a concentration of 0.2 mM onwards; complete conversion was observed at a concentration of 1.02 mM and above. Zingerone was found to confer protection against SnCl2-induced oxidative damage to genomic and plasmid DNA at concentrations of 500 and 750 μg/mL onwards, respectively. This protective effect was further confirmed in the presence of UV/H2O2-a known reactive oxygen species (ROS) generating system-wherein protection by zingerone against ROS-mediated DNA damage was observed at a concentration of 250 μg/mL onwards in a dose-dependent manner. This study clearly indicated the in vitro DNA protective property of zingerone against SnCl2-induced, ROS-mediated DNA damage.

  12. Vaporized hydrogen peroxide sterilization of freeze dryers.

    PubMed

    Johnson, J W; Arnold, J F; Nail, S L; Renzi, E

    1992-01-01

    The feasibility of using vapor hydrogen peroxide (VHP) as an alternative to steam sterilization has been examined using a pilot plant freeze dryer equipped with a prototype vapor generator. Specific objectives of the study discussed in this presentation were to: 1. Identify critical process variables affecting the lethality of VHP to Bacillus stearothermophilus spores, particularly within dead legs in the system. 2. Measure the efficacy of system degassing after sterilization. 3. Determine the effect of repeated sterilization cycles on the integrity of elastomeric components of the freeze dryer. Penetration of adequate concentrations of hydrogen peroxide vapor into small diameter piping, such as tubing connected to pressure gauges, is the most challenging aspect of VHP sterilization of freeze dryers. Prior to equipment modifications, spore strips placed within such dead legs remained positive irrespective of the number of gas/degas pulses and system pressure. Equipment modifications necessary to effect complete kill of biological indicators placed in system dead legs is discussed. Results of this study support the conclusion that vaporized hydrogen peroxide shows promise as an alternative sterilization method for freeze dryers. PMID:1474433

  13. Both near ultraviolet radiation and the oxidizing agent hydrogen peroxide induce a 32-kDa stress protein in normal human skin fibroblasts

    SciTech Connect

    Keyse, S.M.; Tyrrell, R.M.

    1987-10-25

    We have analyzed the pattern of protein synthesis in solar near ultraviolet (334 nm, 365 nm) and near visible (405 nm) irradiated normal human skin fibroblasts. Two hours after irradiation we find that one major stress protein of approximately 32 kDa is induced in irradiated cells. This protein is not induced by ultraviolet radiation at wavelengths shorter than 334 nm and is not inducible by heat shock treatment of these cells. Although sodium arsenite, diamide, and menadione all induced a 32-kDa protein, they also induced the major heat shock proteins. In contrast, the oxidizing agent, hydrogen peroxide, induced the low molecular weight stress protein without causing induction of the major heat shock proteins. A comparison of the 32-kDa proteins induced by sodium arsenite, H/sub 2/O/sub 2/, and solar near ultraviolet radiation using chemical peptide mapping shows that they are closely related. These results imply that the pathways for induction of the heat shock response and the 32-kDa protein are not identical and suggest that, at least in the case of radiation and treatment with H/sub 2/O/sub 2/, the 32-kDa protein might be induced in response to cellular oxidative stress. This conclusion is supported by the observation that depletion of endogenous cellular glutathione prior to solar near ultraviolet irradiation lowers the fluence threshold for induction of the 32-kDa stress protein.

  14. Flavonoid Fraction of Orange and Bergamot Juices Protect Human Lung Epithelial Cells from Hydrogen Peroxide-Induced Oxidative Stress

    PubMed Central

    Ferlazzo, Nadia; Visalli, Giuseppa; Smeriglio, Antonella; Cirmi, Santa; Lombardo, Giovanni Enrico; Campiglia, Pietro; Di Pietro, Angela; Navarra, Michele

    2015-01-01

    It has been reported that oxidant/antioxidant imbalance triggers cell damage that in turn causes a number of lung diseases. Flavonoids are known for their health benefits, and Citrus fruits juices are one of the main food sources of these secondary plant metabolites. The present study was designed to evaluate the effect of the flavonoid fraction of bergamot and orange juices, on H2O2-induced oxidative stress in human lung epithelial A549 cells. First we tested the antioxidant properties of both extracts in cell-free experimental models and then we assayed their capability to prevent the cytotoxic effects induced by H2O2. Our results demonstrated that both Citrus juice extracts reduce the generation of reactive oxygen species and membrane lipid peroxidation, improve mitochondrial functionality, and prevent DNA-oxidative damage in A549 cells incubated with H2O2. Our data indicate that the mix of flavonoids present in both bergamot and orange juices may be of use in preventing oxidative cell injury and pave the way for further research into a novel healthy approach to avoid lung disorders. PMID:26221182

  15. Hydrogen peroxide mediates hyperglycemia-induced invasive activity via ERK and p38 MAPK in human pancreatic cancer

    PubMed Central

    Ma, Jiguang; Li, Xuqi; Xu, Qinhong; Duan, Wanxing; Chen, Xin; Lv, Yunfu; Zhou, Shuang; Wu, Erxi; Ma, Qingyong; Huo, Xiongwei

    2015-01-01

    Diabetes mellitus and pancreatic cancer are intimately related, as approximately 85% of pancreatic cancer patients suffer from glucose intolerance or even diabetes. In this study, we evaluate the underlying mechanism by which hyperglycemia modulates the invasive potential of cancer cells and contributes to their enhanced metastatic behavior. Here we show that hyperglycemia increases the hydrogen peroxide (H2O2) concentration through up-regulation of manganese superoxide dismutase (SOD2) expression, which further activates the ERK and p38 MAPK pathways, as well as the transcription factors NF-κB and AP-1, in a time-dependent manner. The invasion of pancreatic cancer cells resulting from the activation of the H2O2/MAPK axis under high glucose conditions is effectively inhibited by PD 98059 (ERK inhibitor), SB 203580 (p38 MAPK inhibitor), polyethylene glycol-conjugated catalase (PEG-CAT), or the siRNA specific to SOD2. In addition, streptozotocin-treated diabetic nude mice exhibit a stronger tumor invasive ability in renal capsule xenografts which could be suppressed by PEG-CAT treatment. Furthermore, the integrated optical density (IOD) of SOD2 and uPA stainings is higher in the tumor tissues of pancreatic cancer patients with diabetes compared with pancreatic cancer patients with euglycemia. Taken together, our results demonstrate that hyperglycemia enhances cell invasive ability through the SOD2/H2O2/MAPK axis in human pancreatic cancer. Thus, SOD2/H2O2/MAPK axis may represent a promising therapeutic target for pancreatic cancer patients combined with diabetes mellitus. PMID:26439801

  16. Growth temperature-induced changes in biomass accumulation, photosynthesis and glutathione redox homeostasis as influenced by hydrogen peroxide in cucumber.

    PubMed

    Li, Hao; Wang, Xue Min; Chen, Li; Ahammed, Golam Jalal; Xia, Xiao Jian; Shi, Kai; Considine, Michael J; Yu, Jing Quan; Zhou, Yan Hong

    2013-10-01

    Hydrogen peroxide (H2O2) and glutathione (GSH) are involved in the stress response in plants. To elucidate the role of H2O2 in the acclimation of CO2 assimilation under sub- or supra-optimal growth temperatures, we examined the effect and interaction of H2O2 manipulation on the photosynthetic metabolism of cucumber plants (Cucumis sativus L.) grown under five temperature regimes spanning above and below the optimal growth temperature; 11/9, 18/15, 25/20, 32/27, and 39/33 °C (day/night), with or without dimethylthiourea (DMTU) or H2O2 treatment. As expected, exposure to sub- or supra-optimal growth temperatures resulted in decreased plant growth, associated with a decline in CO2 assimilation (Asat), Rubisco content, and activities of enzymes involved in the CO2 assimilation, as well as a decrease in the ratio of reduced (GSH) to oxidized (GSSG) glutathione (GSH/GSSG). Foliar application of H2O2 promoted, whilst DMTU retarded the capacity of plants to acclimate to non-optimal growth temperatures; this was consistently shown in altered activity of redox-sensitive enzymes involved in CO2 assimilation. These results strongly suggest that the influence of growth temperature on CO2 assimilation was primarily targeted at the activities of the redox-sensitive enzymes of CO2 assimilation. Meanwhile, the data suggest that the cellular H2O2 level is an important signal for the glutathione-dependent regulation of redox-sensitive enzymes of CO2 assimilation in cucumber plants.

  17. Hydrogen peroxide-induced antioxidant activities and cardiotonic glycoside accumulation in callus cultures of endemic Digitalis species.

    PubMed

    Cingoz, Gunce Sahin; Verma, Sandeep Kumar; Gurel, Ekrem

    2014-09-01

    The effect of hydrogen peroxide (H2O2) on callus cultures of four Digitalis species (Digitalis lamarckii, Digitalis trojana, Digitalis davisiana and Digitalis cariensis) increased catalase (CAT), superoxide dismutase (SOD), total phenolic, proline activity and cardiotonic glycoside production. Callus derived from hypocotyl explants was cultured on Murashige and Skoog medium supplemented with 0.25 mg L(-1) indole-3-acetic acid (IAA) and 0.5 mg L(-1) thidiazuron (TDZ). After a month of culture, callus was transferred to MS medium containing 10 mM H2O2 and then incubated for 6 h. The amount of five cardenolides (Lanatoside C, Digitoxin, Digoxigenin, Gitoxigenin and Digoxin) as well as CAT, SOD, total phenolic, proline activity from Digitalis species were compared. No digoxin was detected in all treatments and control groups. The total cardenolides estimated were in the order of D. lamarckii (586.65  μg g(-1) dw), D. davisiana (506.79 μg g(-1) dw), D. cariensis (376.60 μg g(-1) dw) and D. trojana (282.39 μg g(-1) dw). It was clear that H2O2 pre-treatment resulted in an increase in enzymatic and nonenzymatic antioxidants. However, a significant negative relationship between cardenolides production and overall activities of CAT, SOD, total phenolic and proline was evident. The described protocol here will be useful for the development of new strategies for a large-scale production of cardenolides.

  18. Long-lasting pain-related behaviors in mouse chronic cystitis model induced by a single intravesical injection of hydrogen peroxide.

    PubMed

    Dogishi, Koji; Kodera, Mizuki; Oyama, Shohei; Shirakawa, Hisashi; Nakagawa, Takayuki; Kaneko, Shuji

    2015-12-01

    We previously established a long-lasting cystitis model by an intravesical injection of hydrogen peroxide (H2O2) into mice. In this study, we assessed the pain-related behaviors in the cystitis model. An intravesical injection of 1.5% H2O2 transiently decreased spontaneous locomotor activity at 3 h after injection, indicative of acute spontaneous pain. In contrast, licking response to a bladder distention was slowly observed as licks to the lower abdomen at 7 and 14 days after injection, which was attenuated by amitriptyline and morphine, but not by oxybutynin. These results suggest that H2O2-induced chronic cystitis model shows delayed and long-lasting painful pathological condition.

  19. Complex I and complex III inhibition specifically increase cytosolic hydrogen peroxide levels without inducing oxidative stress in HEK293 cells

    PubMed Central

    Forkink, Marleen; Basit, Farhan; Teixeira, José; Swarts, Herman G.; Koopman, Werner J.H.; Willems, Peter H.G.M.

    2015-01-01

    Inhibitor studies with isolated mitochondria demonstrated that complex I (CI) and III (CIII) of the electron transport chain (ETC) can act as relevant sources of mitochondrial reactive oxygen species (ROS). Here we studied ROS generation and oxidative stress induction during chronic (24 h) inhibition of CI and CIII using rotenone (ROT) and antimycin A (AA), respectively, in intact HEK293 cells. Both inhibitors stimulated oxidation of the ROS sensor hydroethidine (HEt) and increased mitochondrial NAD(P)H levels without major effects on cell viability. Integrated analysis of cells stably expressing cytosolic- or mitochondria-targeted variants of the reporter molecules HyPer (H2O2-sensitive and pH-sensitive) and SypHer (H2O2-insensitive and pH-sensitive), revealed that CI- and CIII inhibition increased cytosolic but not mitochondrial H2O2 levels. Total and mitochondria-specific lipid peroxidation was not increased in the inhibited cells as reported by the C11-BODIPY581/591 and MitoPerOx biosensors. Also expression of the superoxide-detoxifying enzymes CuZnSOD (cytosolic) and MnSOD (mitochondrial) was not affected. Oxyblot analysis revealed that protein carbonylation was not stimulated by CI and CIII inhibition. Our findings suggest that chronic inhibition of CI and CIII: (i) increases the levels of HEt-oxidizing ROS and (ii) specifically elevates cytosolic but not mitochondrial H2O2 levels, (iii) does not induce oxidative stress or substantial cell death. We conclude that the increased ROS levels are below the stress-inducing level and might play a role in redox signaling. PMID:26516986

  20. Inhibitory heterotrimeric GTP-binding proteins inhibit hydrogen peroxide-induced apoptosis by up-regulation of Bcl-2 via NF-{kappa}B in H1299 human lung cancer cells

    SciTech Connect

    Seo, Mi Ran; Nam, Hyo-Jung; Kim, So-Young; Juhnn, Yong-Sung

    2009-04-03

    Inhibitory heterotrimeric GTP-binding proteins (Gi proteins) mediate a variety of signaling pathways by coupling receptors and effectors to regulate cellular proliferation, differentiation, and apoptosis. However, the role of Gi proteins in the modulation of hydrogen peroxide-induced apoptosis is not clearly understood. Thus, we investigated the effect of Gi proteins on hydrogen peroxide-induced apoptosis and the underlying mechanisms in H1299 human lung cancer cells. The stable expression of constitutively active alpha subunits of Gi1 (G{alpha}i1QL), Gi2, or Gi3 inhibited hydrogen peroxide-induced apoptosis. The expression of G{alpha}i1QL up-regulated Bcl-2 expression, and the knockdown of Bcl-2 with siRNA abolished the anti-apoptotic effect of G{alpha}i1QL. G{alpha}i1 induced the transcription of Bcl-2 by activation of NF-{kappa}B, which resulted from an increase in NF-{kappa}B p50 protein. We conclude that G{alpha}i1 inhibits hydrogen peroxide-induced apoptosis of H1299 lung cancer cells by up-regulating the transcription of Bcl-2 through a p50-mediated NF-{kappa}B activation.

  1. Protective effects of hydroxybenzoic acids and their esters on cell damage induced by hydroxyl radicals and hydrogen peroxides.

    PubMed

    Masaki, H; Okamoto, N; Sakaki, S; Sakurai, H

    1997-04-01

    The purpose of this study was to evaluate the hydroxyl radical scavenging activities of hydroxybenzoic acids and their esters from both chemical and biological aspects. These activities of hydroxybenzoic acids and their related compounds were estimated by ESR-spin trapping method, in which 3,4,5-trihydroxybenzoic acid and its ethyl and propyl esters showed the highest activities as estimated by IC50 value (50% inhibition concentration of hydroxyl radicals generated in the system): 78.04 +/- 11.23, 95.95 +/- 2.64, and 86.46 +/- 2.31 microM, respectively. In addition, 3,4,5-trihydroxybenzoic acid (gallic acid) at a concentration of 25 microM, protected against dermal fibroblast cell damage induced by H2O2, and enhanced the survival to 83.8 +/- 3.1%, in which the survival of control was 44.2 +/- 1.0%. Based on these results, the pretreatment effects of 3,4,5-trihydroxybenzoic acid n-alkyl esters on cell damage induced by H2O2 were examined. The survival of fibroblasts pretreated with the esters increased depending on the alkyl chain-length. Both C12 and C16 alkyl esters gave almost complete cell survival of 89.5 +/- 2.0% and 91.3 +/- 1.0%, respectively. The order of the protective effects of the compounds was in good agreement with that of their partition coefficients, suggesting that 3,4,5-trihydroxybenzoic acid alkyl esters are incorporated into fibroblasts, and thus prevent the cells from the toxicity caused by H2O2. In addition, an increase of intracellular peroxide formation in fibroblasts induced by UVA-irradiation, was suppressed to 2.27 +/- 0.41 nmol/10(4) cells by pretreatment with C16 alkyl ester at a concentration of 25 microM. Since 3,4,5-trihydroxybenzoic group has been demonstrated to possess a potent scavenging activity of hydroxyl radicals, this moiety was indicated to be important in preventing cell damage induced by UVA or H2O2: in turn, these produce hydroxyl radicals in the presence of trace metal ions such as iron and copper in cells.

  2. PROCESS OF ELIMINATING HYDROGEN PEROXIDE IN SOLUTIONS CONTAINING PLUTONIUM VALUES

    DOEpatents

    Barrick, J.G.; Fries, B.A.

    1960-09-27

    A procedure is given for peroxide precipitation processes for separating and recovering plutonium values contained in an aqueous solution. When plutonium peroxide is precipitated from an aqueous solution, the supernatant contains appreciable quantities of plutonium and peroxide. It is desirable to process this solution further to recover plutonium contained therein, but the presence of the peroxide introduces difficulties; residual hydrogen peroxide contained in the supernatant solution is eliminated by adding a nitrite or a sulfite to this solution.

  3. TRIM4; a novel mitochondrial interacting RING E3 ligase, sensitizes the cells to hydrogen peroxide (H2O2) induced cell death.

    PubMed

    Tomar, Dhanendra; Prajapati, Paresh; Lavie, Julie; Singh, Kritarth; Lakshmi, Sripada; Bhatelia, Khyati; Roy, Milton; Singh, Rochika; Bénard, Giovanni; Singh, Rajesh

    2015-12-01

    The emerging evidences suggest that posttranslational modification of target protein by ubiquitin (Ub) not only regulate its turnover through ubiquitin proteasome system (UPS) but is a critical regulator of various signaling pathways. During ubiquitination, E3 ligase recognizes the target protein and determines the topology of ubiquitin chains. In current study, we studied the role of TRIM4, a member of the TRIM/RBCC protein family of RING E3 ligase, in regulation of hydrogen peroxide (H2O2) induced cell death. TRIM4 is expressed differentially in human tissues and expressed in most of the analyzed human cancer cell lines. The subcellular localization studies showed that TRIM4 forms distinct cytoplasmic speckle like structures which transiently interacts with mitochondria. The expression of TRIM4 induces mitochondrial aggregation and increased level of mitochondrial ROS in the presence of H2O2. It sensitizes the cells to H2O2 induced death whereas knockdown reversed the effect. TRIM4 potentiates the loss of mitochondrial transmembrane potential and cytochrome c release in the presence of H2O2. The analysis of TRIM4 interacting proteins showed its interaction with peroxiredoxin 1 (PRX1), including other proteins involved in regulation of mitochondrial and redox homeostasis. TRIM4 interaction with PRX1 is critical for the regulation of H2O2 induced cell death. Collectively, the evidences in the current study suggest the role of TRIM4 in regulation of oxidative stress induced cell death.

  4. Water-soluble fractions from defatted sesame seeds protect human neuroblast cells against peroxyl radicals and hydrogen peroxide-induced oxidative stress.

    PubMed

    Ben Othman, Sana; Katsuno, Nakako; Kitayama, Akemi; Fujimura, Makoto; Kitaguchi, Kohji; Yabe, Tomio

    2016-09-01

    Oxidative stress is involved in the development of aging-related diseases, such as neurodegenerative diseases. Dietary antioxidants that can protect neuronal cells from oxidative damage play an important role in preventing such diseases. Previously, we reported that water-soluble fractions purified from defatted sesame seed flour exhibit good antioxidant activity in vitro. In the present study, we investigated the protective effects of white and gold sesame seed water-soluble fractions (WS-wsf and GS-wsf, respectively) against 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) and hydrogen peroxide (H2O2) induced oxidative stress in human neuroblast SH-SY5Y cells. Pretreatment with WS-wsf and GS-wsf did not protect cells against AAPH-induced cytotoxicity, while simultaneous co-treatment with AAPH significantly improved cell viability and inhibited membrane lipid peroxidation. These results suggest that WS-wsf and GS-wsf protect cells from AAPH-induced extracellular oxidative damage via direct scavenging of peroxyl radicals. When oxidative stress was induced by H2O2, pretreatment WS-wsf and GS-wsf significantly enhanced cell viability. These results suggest that in addition to radical scavenging, WS-wsf and GS-wsf enhance cellular resistance to intracellular oxidative stress by activation of the Nrf-2/ARE pathway as confirmed by the increased Nrf2 protein level in the nucleus and increased heme oxygenase 1 (HO-1) mRNA expression. The roles of ferulic and vanillic acids as bioactive antioxidants in these fractions were also confirmed. In conclusion, our results indicated that WS-wsf and GS-wsf, which showed antioxidant activity in vitro, are also efficient antioxidants in a cell system protecting SH-SY5Y cells against both extracellular and intracellular oxidative stress.

  5. Hazard Assessment of Personal Protective Clothing for Hydrogen Peroxide Service

    NASA Technical Reports Server (NTRS)

    Greene, Ben; McClure, Mark B.; Johnson, Harry T.

    2004-01-01

    Selection of personal protective equipment (PPE) for hydrogen peroxide service is an important part of the hazard assessment process. But because drip testing of chemical protective clothing for hydrogen peroxide service has not been reported for about 40 years, it is of great interest to test new protective clothing materials with new, high-concentration hydrogen peroxide following similar procedures. The suitability of PPE for hydrogen peroxide service is in part determined by observations made when hydrogen peroxide is dripped onto swatches of protective clothing material. Protective clothing material was tested as received, in soiled condition, and in grossly soiled condition. Materials were soiled by pretreating the material with potassium permanganate (KMnO4) solution then drying to promote a reaction. Materials were grossly soiled with solid KMnO4 to greatly promote reaction. Observations of results including visual changes to the hydrogen peroxide and materials, times to ignition, and self-extinguishing characteristics of the materials are reported.

  6. [Carbamide peroxide as source of hydrogen peroxide for the luminol application at crime scenes].

    PubMed

    Schwarz, Lothar; Hermanowski, Mona-Lena

    2009-01-01

    The solution of hydrogen peroxide is a critical ingredient of the Weber luminol application for blood detection at the crime scene. An ideal alternative to the unstable hydrogen peroxide is a solid compound which is easy to transport, stable and quick to solve in water at the crime scene. Carbamide peroxide (urea peroxide) is one of these solid hydrogen peroxide carriers which is easy to obtain as one gram tablets. At dry conditions it is stable over a long period at room temperature and even for a short time at higher temperatures. But at 70 degrees C (180 degrees F) the tablets go out of shape and cake after one hour. In the application of luminol there are no differences between the use of hydrogen peroxide and carbamide peroxide.

  7. A Modified Demonstration of the Catalytic Decomposition of Hydrogen Peroxide

    NASA Astrophysics Data System (ADS)

    Trujillo, Carlos Alexander

    2005-06-01

    A safer and cheaper version of the popular catalyzed decomposition of hydrogen peroxide demonstration commonly called the “Elephants’ Toothpaste” is presented. Hydrogen peroxide is decomposed in the presence of a surfactant by the enzyme catalase producing foam. Catalase has a higher activity compared with the traditional iodide and permits the use of diluted hydrogen peroxide solutions. The demonstration can be made with household products with similar amazing effects.

  8. Lycopene protects human SH-SY5Y neuroblastoma cells against hydrogen peroxide-induced death via inhibition of oxidative stress and mitochondria-associated apoptotic pathways

    PubMed Central

    FENG, CHUNSHENG; LUO, TIANFEI; ZHANG, SHUYAN; LIU, KAI; ZHANG, YANHONG; LUO, YINAN; GE, PENGFEI

    2016-01-01

    Oxidative stress, which is characterized by excessive production of reactive oxygen species (ROS), is a common pathway that results in neuronal injury or death due to various types of pathological stress. Although lycopene has been identified as a potent antioxidant, its effect on hydrogen peroxide (H2O2)-induced neuronal damage remains unclear. In the present study, pretreatment with lycopene was observed to protect SH-SY5Y neuroblastoma cells against H2O2-induced death via inhibition of apoptosis resulting from activation of caspase-3 and translocation of apoptosis inducing factor (AIF) to the nucleus. Furthermore, the over-produced ROS, as well as the reduced activities of anti-oxidative enzymes, superoxide dismutase and catalase, were demonstrated to be alleviated by lycopene. Additionally, lycopene counteracted H2O2-induced mitochondrial dysfunction, which was evidenced by suppression of mitochondrial permeability transition pore opening, attenuation of the decline of the mitochondrial membrane potential, and inhibition of the increase of Bax and decrease of Bcl-2 levels within the mitochondria. The release of cytochrome c and AIF from the mitochondria was also reduced. These results indicate that lycopene is a potent neuroprotectant against apoptosis, oxidative stress and mitochondrial dysfunction, and could be administered to prevent neuronal injury or death. PMID:27035331

  9. Amperometric sensing of hydrogen peroxide vapor for security screening.

    PubMed

    Benedet, John; Lu, Donglai; Cizek, Karel; La Belle, Jeff; Wang, Joseph

    2009-09-01

    Rapid detection of the hydrogen peroxide precursor of peroxide explosives is required in numerous security screening applications. We describe a highly sensitive and selective amperometric detection of hydrogen peroxide vapor at an agarose-coated Prussian-blue (PB) modified thick-film carbon transducer. The sensor responds rapidly and reversibly to dynamic changes in the level of the peroxide vapor, with no apparent carry over and with a detection limit of 6 ppbv. The remarkable selectivity of the PB-based screen-printed electrode towards hydrogen peroxide leads to effective discrimination against common beverage samples. For example, blind tests have demonstrated the ability to selectively and non-invasively identify concealed hydrogen peroxide in drinking cups and bottles. The attractive performance of the new microfabricated PB-based amperometric peroxide vapor sensor indicates great potential for addressing a wide range of security screening and surveillance applications.

  10. Use of Hydrogen Peroxide to Disinfect Hydroponic Plant Growth Systems

    NASA Technical Reports Server (NTRS)

    Barta, Daniel J.; Henderson, Keith

    2000-01-01

    Hydrogen peroxide was studied as an alternative to conventional bleach and rinsing methods to disinfect hydroponic plant growth systems. A concentration of 0.5% hydrogen peroxide was found to be effective. Residual hydrogen peroxide can be removed from the system by repeated rinsing or by flowing the solution through a platinum on aluminum catalyst. Microbial populations were reduced to near zero immediately after treatment but returned to pre-disinfection levels 2 days after treatment. Treating nutrient solution with hydrogen peroxide and planting directly into trays being watered with the nutrient solution without replenishment, was found to be detrimental to lettuce germination and growth.

  11. Monolithic Hydrogen Peroxide Catalyst Bed Development

    NASA Technical Reports Server (NTRS)

    Ponzo, J. B.

    2003-01-01

    With recent increased industry and government interest in rocket grade hydrogen peroxide as a viable propellant, significant effort has been expended to improve on earlier developments. This effort has been predominately centered in improving heterogeneous. typically catalyst beds; and homogeneous catalysts, which are typically solutions of catalytic substances. Heterogeneous catalyst beds have traditionally consisted of compressed wire screens plated with a catalytic substance, usually silver, and were used m many RCS applications (X-1, Mercury, and Centaur for example). Aerojet has devised a heterogeneous catalyst design that is monolithic (single piece), extremely compact, and has pressure drops equal to or less than traditional screen beds. The design consists of a bonded stack of very thin, photoetched metal plates, silver coated. This design leads to a high surface area per unit volume and precise flow area, resulting in high, stable, and repeatable performance. Very high throughputs have been demonstrated with 90% hydrogen peroxide. (0.60 lbm/s/sq in at 1775-175 psia) with no flooding of the catalyst bed. Bed life of over 900 seconds has also been demonstrated at throughputs of 0.60 lbm/s/sq in across varying chamber pressures. The monolithic design also exhibits good starting performance, short break-in periods, and will easily scale to various sizes.

  12. PROPULSE 980: A Hydrogen Peroxide Enrichment System

    NASA Technical Reports Server (NTRS)

    Boxwell, Robert; Bromley, G.; Wanger, Robert; Pauls, Dan; Maynard, Bryon; McNeal, Curtis; Dumbacher, D. L. (Technical Monitor)

    2000-01-01

    The PROPULSE 980 unit is a transportable processing plant that enriches aerospace grade hydrogen peroxide from 90% to 98% final concentration. The unit was developed by Degussa-H Is, in cooperation with Orbital, NASA Marshall Space Center, and NASA Stennis Space Center. The system is a self-contained unit that houses all of the process equipment, instrumentation and controls to perform the concentration operation nearly autonomously. It is designed to produce non-bulk quantities of 98% hydrogen peroxide. The enrichment unit design also maintains system, personnel and environmental safety during all aspects of the enrichment process and final product storage. As part of the Propulse 980 checkout and final buyoff, it will be disassembled at the Degussa-H Is Corporation plant in Theodore, AL, transported to the Stennis Space Center, reassembled and subjected to a series of checkout tests to verify design objectives have been met. This paper will summarize the basic project elements and provide an update on the present status of the project.

  13. Simple, field portable colorimetric detection device for organic peroxides and hydrogen peroxide

    SciTech Connect

    Pagoria, Philip F.; Mitchell, Alexander R.; Whipple, Richard E.; Carman, M. Leslie; Reynolds, John G.; Nunes, Peter; Shields, Sharon J.

    2010-11-09

    A simple and effective system for the colorimetric determination of organic peroxides and hydrogen peroxide. A peroxide pen utilizing a swipe material attached to a polyethylene tube contains two crushable vials. The two crushable vials contain a colorimetric reagent separated into dry ingredients and liquid ingredients. After swiping a suspected substance or surface the vials are broken, the reagent is mixed thoroughly and the reagent is allowed to wick into the swipe material. The presence of organic peroxides or hydrogen peroxide is confirmed by a deep blue color.

  14. Protective effect of polypeptides from larva of housefly (Musca domestica) on hydrogen peroxide-induced oxidative damage in HepG2 cells.

    PubMed

    Zhu, Li; Wang, Pan; Qin, Qi-Lian; Zhang, Huan; Wu, Yi-Jun

    2013-10-01

    Housefly (Musca domestica) is an important medical insect and its larva is an ideal high protein food source. We isolated from housefly larvae the polypeptides hydrolyzed by neutral protease (PHNP), and investigated the protective effect of PHNP on hydrogen peroxide (H₂O₂)-induced oxidative damage in HepG2 cells. Cells exposed to H₂O₂ showed a marked decrease in proliferation and intracellular superoxide dismutase (SOD) activity, and a significant increase in reactive oxygen species (ROS) level and malondialdehyde (MDA) content. H₂O₂ also caused apoptosis and mitochondrial dysfunction including mitochondrial fragmentation and the loss of mitochondrial membrane potential. Pretreatment with PHNP at concentrations of 2.5, 5, 10 μg/mL blocked these H₂O₂-induced cellular events in a dose-dependent manner. The effect of PHNP at 10 μg/mL is equal to that of ascorbic acid at 10 μM. In summary, PHNP has a protective effect against H₂O₂-induced oxidative injury in cells due to its ability to decrease intracellular ROS and elevate antioxidant enzyme activities.

  15. Baicalein protects C6 glial cells against hydrogen peroxide-induced oxidative stress and apoptosis through regulation of the Nrf2 signaling pathway.

    PubMed

    Choi, Eun-Ok; Jeong, Jin-Woo; Park, Cheol; Hong, Su Hyun; Kim, Gi-Young; Hwang, Hye-Jin; Cho, Eun-Ju; Choi, Yung Hyun

    2016-03-01

    Baicalein, a flavonoid originally obtained from the roots of Scutellaria baicalensis Georgi, has been reported to possess various biological properties. Although several studies have demonstrated the anti-oxidative activity of baicalein, its neuroprotective mechanisms have not been clearly established. The present study aimed to detect the effects of baicalein against hydrogen peroxide (H2O2)-induced neuronal damage in C6 glial cells and to investigate the molecular mechanisms involved in this process. The results demonstrated that baicalein effectively inhibited H2O2-induced growth and reactive oxygen species (ROS) generation. We noted that Baicalein also attenuated the H2O2‑induced formation of comet tail, phosphorylation of p-γH2A.X, loss of mitochondrial membrane potential (MMP or ΔΨm), and changes to apoptosis‑related protein expression, which suggests that it can prevent H2O2‑induced cellular DNA damage and apoptotic cell death. Furthermore, treatment with baicalein effectively induced the expression of nuclear factor-erythroid 2-related factor 2 (Nrf2) as well as heme oxygenase-1 (HO-1) and thioredoxin reductase 1 (TrxR1) in a concentration and time-dependent manner. Moreover, the protective effects of baicalein against H2O2‑induced DNA damage and apoptosis were abolished by zinc protoporphyrin (ZnPP) IX, a HO-1 inhibitor, and auranofin, a TrxR inhibitor. In addition, we noted that the cytoprotective effects of baicalein were attenuated by transient transfection with Nrf2-specific small interfering RNA (siRNA). The findings of our present study suggest that baicalein enhances cellular antioxidant defense capacity through the inhibition of ROS generation and the activation of the Nrf2 signaling pathway, thus protecting C6 cells from H2O2-induced neuronal damage.

  16. Molecular mechanisms of 6-hydroxydopamine-induced cytotoxicity in PC12 cells: involvement of hydrogen peroxide-dependent and -independent action.

    PubMed

    Saito, Yoshiro; Nishio, Keiko; Ogawa, Yoko; Kinumi, Tomoya; Yoshida, Yasukazu; Masuo, Yoshinori; Niki, Etsuo

    2007-03-01

    The neurotoxin 6-hydroxydopamine (6-OHDA) has been widely used to generate an experimental model of Parkinson's disease. It has been reported that reactive oxygen species (ROS), such as the superoxide anion and hydrogen peroxide (H2O2), generated from 6-OHDA are involved in its cytotoxicity; however, the contribution and role of ROS in 6-OHDA-induced cell death have not been fully elucidated. In the present study using PC12 cells, we observed the generation of 50 microM H2O2 from a lethal concentration of 100 microM 6-OHDA within a few minutes, and compared the sole effect of H2O2 with 6-OHDA. Catalase, an H2O2-removing enzyme, completely abolished the cytotoxic effect of H2O2, while a significant but partial protective effect was observed against 6-OHDA. 6-OHDA induced peroxiredoxin oxidation, cytochrome c release, and caspase-3 activation. Catalase exhibited a strong inhibitory effect against the peroxiredoxin oxidation, and cytochrome c release induced by 6-OHDA; however, caspase-3 activation was not effectively inhibited by catalase. On the other hand, 6-OHDA-induced caspase-3 activation was inhibited in the presence of caspase-8, caspase-9, and calpain inhibitors. These results suggest that the H2O2 generated from 6-OHDA plays a pivotal role in 6-OHDA-induced peroxiredoxin oxidation, and cytochrome c release, while H2O2- and cytochrome c-independent caspase activation pathways are involved in 6-OHDA-induced neurotoxicity. These findings may contribute to explain the importance of generated H2O2 and secondary products as a second messenger of 6-OHDA-induced cell death signal linked to Parkinson's disease.

  17. Demonstration of the Catalytic Decomposition of Hydrogen Peroxide.

    ERIC Educational Resources Information Center

    Conklin, Alfred R. Jr.; Kessinger, Angela

    1996-01-01

    Describes a demonstration known as Elephant's Toothpaste in which the decomposition of hydrogen peroxide is catalyzed by iodide. Oxygen is released and soap bubbles are produced. The foam produced is measured, and results show a good relationship between the amount of foam and the concentration of the hydrogen peroxide. (DDR)

  18. Low Temperature-Induced 30 (LTI30) positively regulates drought stress resistance in Arabidopsis: effect on abscisic acid sensitivity and hydrogen peroxide accumulation.

    PubMed

    Shi, Haitao; Chen, Yinhua; Qian, Yongqiang; Chan, Zhulong

    2015-01-01

    As a dehydrin belonging to group II late embryogenesis abundant protein (LEA) family, Arabidopsis Low Temperature-Induced 30 (LTI30)/XERO2 has been shown to be involved in plant freezing stress resistance. However, the other roles of AtLTI30 remain unknown. In this study, we found that the expression of AtLTI30 was largely induced by drought stress and abscisic acid (ABA) treatments. Thereafter, AtLTI30 knockout mutants and overexpressing plants were isolated to investigate the possible involvement of AtLTI30 in ABA and drought stress responses. AtLTI30 knockout mutants were less sensitive to ABA-mediated seed germination, while AtLTI30 overexpressing plants were more sensitive to ABA compared with wild type (WT). Consistently, the AtLTI30 knockout mutants displayed decreased drought stress resistance, while the AtLTI30 overexpressing plants showed improved drought stress resistance compared with WT, as evidenced by a higher survival rate and lower leaf water loss than WT after drought stress. Moreover, manipulation of AtLTI30 expression positively regulated the activities of catalases (CATs) and endogenous proline content, as a result, negatively regulated drought stress-triggered hydrogen peroxide (H2O2) accumulation. All these results indicate that AtLTI30 is a positive regulator of plant drought stress resistance, partially through the modulation of ABA sensitivity, H2O2 and proline accumulation. PMID:26539205

  19. Low Temperature-Induced 30 (LTI30) positively regulates drought stress resistance in Arabidopsis: effect on abscisic acid sensitivity and hydrogen peroxide accumulation.

    PubMed

    Shi, Haitao; Chen, Yinhua; Qian, Yongqiang; Chan, Zhulong

    2015-01-01

    As a dehydrin belonging to group II late embryogenesis abundant protein (LEA) family, Arabidopsis Low Temperature-Induced 30 (LTI30)/XERO2 has been shown to be involved in plant freezing stress resistance. However, the other roles of AtLTI30 remain unknown. In this study, we found that the expression of AtLTI30 was largely induced by drought stress and abscisic acid (ABA) treatments. Thereafter, AtLTI30 knockout mutants and overexpressing plants were isolated to investigate the possible involvement of AtLTI30 in ABA and drought stress responses. AtLTI30 knockout mutants were less sensitive to ABA-mediated seed germination, while AtLTI30 overexpressing plants were more sensitive to ABA compared with wild type (WT). Consistently, the AtLTI30 knockout mutants displayed decreased drought stress resistance, while the AtLTI30 overexpressing plants showed improved drought stress resistance compared with WT, as evidenced by a higher survival rate and lower leaf water loss than WT after drought stress. Moreover, manipulation of AtLTI30 expression positively regulated the activities of catalases (CATs) and endogenous proline content, as a result, negatively regulated drought stress-triggered hydrogen peroxide (H2O2) accumulation. All these results indicate that AtLTI30 is a positive regulator of plant drought stress resistance, partially through the modulation of ABA sensitivity, H2O2 and proline accumulation.

  20. Low Temperature-Induced 30 (LTI30) positively regulates drought stress resistance in Arabidopsis: effect on abscisic acid sensitivity and hydrogen peroxide accumulation

    PubMed Central

    Shi, Haitao; Chen, Yinhua; Qian, Yongqiang; Chan, Zhulong

    2015-01-01

    As a dehydrin belonging to group II late embryogenesis abundant protein (LEA) family, Arabidopsis Low Temperature-Induced 30 (LTI30)/XERO2 has been shown to be involved in plant freezing stress resistance. However, the other roles of AtLTI30 remain unknown. In this study, we found that the expression of AtLTI30 was largely induced by drought stress and abscisic acid (ABA) treatments. Thereafter, AtLTI30 knockout mutants and overexpressing plants were isolated to investigate the possible involvement of AtLTI30 in ABA and drought stress responses. AtLTI30 knockout mutants were less sensitive to ABA-mediated seed germination, while AtLTI30 overexpressing plants were more sensitive to ABA compared with wild type (WT). Consistently, the AtLTI30 knockout mutants displayed decreased drought stress resistance, while the AtLTI30 overexpressing plants showed improved drought stress resistance compared with WT, as evidenced by a higher survival rate and lower leaf water loss than WT after drought stress. Moreover, manipulation of AtLTI30 expression positively regulated the activities of catalases (CATs) and endogenous proline content, as a result, negatively regulated drought stress-triggered hydrogen peroxide (H2O2) accumulation. All these results indicate that AtLTI30 is a positive regulator of plant drought stress resistance, partially through the modulation of ABA sensitivity, H2O2 and proline accumulation. PMID:26539205

  1. Mitogen-activated protein kinase-activated protein kinase 2 mediates resistance to hydrogen peroxide-induced oxidative stress in human hepatobiliary cancer cells.

    PubMed

    Nguyen Ho-Bouldoires, Thanh Huong; Clapéron, Audrey; Mergey, Martine; Wendum, Dominique; Desbois-Mouthon, Christèle; Tahraoui, Sylvana; Fartoux, Laetitia; Chettouh, Hamza; Merabtene, Fatiha; Scatton, Olivier; Gaestel, Matthias; Praz, Françoise; Housset, Chantal; Fouassier, Laura

    2015-12-01

    The development and progression of liver cancer are characterized by increased levels of reactive oxygen species (ROS). ROS-induced oxidative stress impairs cell proliferation and ultimately leads to cell death. Although liver cancer cells are especially resistant to oxidative stress, mechanisms of such resistance remain understudied. We identified the MAPK-activated protein kinase 2 (MK2)/heat shock protein 27 (Hsp27) signaling pathway mediating defenses against oxidative stress. In addition to MK2 and Hsp27 overexpression in primary liver tumors compared to adjacent nontumorous tissues, the MK2/Hsp27 pathway is activated by hydrogen peroxide-induced oxidative stress in hepatobiliary cancer cells. MK2 inactivation or inhibition of MK2 or Hsp27 expression increases caspase-3 and PARP cleavage and DNA breaks and therefore cell death. Interestingly, MK2/Hsp27 inhibition decreases antioxidant defenses such as heme oxygenase 1 through downregulation of the transcription factor nuclear factor erythroid-derived 2-like 2. Moreover, MK2/Hsp27 inhibition decreases both phosphorylation of epidermal growth factor receptor (EGFR) and expression of its ligand, heparin-binding EGF-like growth factor. A new identified partner of MK2, the scaffold PDZ protein EBP50, could facilitate these effects through MK2/Hsp27 pathway regulation. These findings demonstrate that the MK2/Hsp27 pathway actively participates in resistance to oxidative stress and may contribute to liver cancer progression.

  2. Measurement of hydrogen peroxide from aircraft

    SciTech Connect

    Kok, G.L.

    1980-01-01

    Hydrogen peroxide (H/sub 2/O/sub 2/) is an important species in both the homogeneous and the heterogeneous chemistry of the troposphere. Measurement of H/sub 2/O/sub 2/ from aircraft provides information on the distribution of H/sub 2/O/sub 2/ in the troposphere and provides a great deal of additional information which cannot be obtained from ground-based measurements. Three analytical techniques for atmospheric H/sub 2/O/sub 2/ are available. Two of these are colorimetric methods involving the formation of a colored complex with titanium salt. In 1978, a chemiluminescent method for the determination of atmospheric H/sub 2/O/sub 2/ was introduced. This method involves the reaction of H/sub 2/O/sub 2/ with luminol in the presence of a copper catalyst, with the chemiluminescence serving as the basis of the analytical reaction.

  3. Locating bomb factories by detecting hydrogen peroxide.

    PubMed

    Romolo, Francesco Saverio; Connell, Samantha; Ferrari, Carlotta; Suarez, Guillaume; Sauvain, Jean-Jacques; Hopf, Nancy B

    2016-11-01

    The analytical capability to detect hydrogen peroxide vapour can play a key role in localizing a site where a H2O2 based Improvised Explosive (IE) is manufactured. In security activities it is very important to obtain information in a short time. For this reason, an analytical method to be used in security activity needs portable devices. The authors have developed the first analytical method based on a portable luminometer, specifically designed and validated to locate IE manufacturing sites using quantitative on-site vapour analysis for H2O2. The method was tested both indoor and outdoor. The results demonstrate that the detection of H2O2 vapours could allow police forces to locate the site, while terrorists are preparing an attack. The collected data are also very important in developing new sensors, able to give an early alarm if located at a proper distance from a site where an H2O2 based IE is prepared.

  4. Hydrogen Peroxide Storage in Small Sealed Tanks

    SciTech Connect

    Whitehead, J.

    1999-10-20

    Unstabilized hydrogen peroxide of 85% concentration has been prepared in laboratory quantities for testing material compatibility and long term storage on a small scale. Vessels made of candidate tank and liner materials ranged in volume from 1 cc to 2540 cc. Numerous metals and plastics were tried at the smallest scales, while promising ones were used to fabricate larger vessels and liners. An aluminum alloy (6061-T6) performed poorly, including increasing homogeneous decay due to alloying elements entering solution. The decay rate in this high strength aluminum was greatly reduced by anodizing. Better results were obtained with polymers, particularly polyvinylidene fluoride. Data reported herein include ullage pressures as a function of time with changing decay rates, and contamination analysis results.

  5. Hydrogen peroxide, nitric oxide and UV RESISTANCE LOCUS8 interact to mediate UV-B-induced anthocyanin biosynthesis in radish sprouts

    PubMed Central

    Wu, Qi; Su, Nana; Zhang, Xiaoyan; Liu, Yuanyuan; Cui, Jin; Liang, Yongchao

    2016-01-01

    The cross talk among hydrogen peroxide (H2O2), nitric oxide (NO) and UV RESISTANCE LOCUS8 (UVR8) in UV-B-induced anthocyanin accumulation in the hypocotyls of radish sprouts was investigated. The results showed that UV-B irradiation significantly increased the anthocyanin accumulation and the expression of UVR8, and a similar trend appeared in radish sprouts subjected to cadmium, chilling and salt stresses regardless of light source. However, these responses disappeared under dark exposure. These results suggest that abiotic stress-induced anthocyanin accumulation and UVR8 expression were light-dependent. Moreover, abiotic stresses all enhanced the production of H2O2 and exogenous H2O2 addition significantly increased the anthocyanin concentration and UVR8 transcription, while these increases were severely inhibited by addition of dimethylthiourea (DMTU, a chemical trap for H2O2). It seems to suggest that H2O2 played an important role in the anthocyanin biosynthesis. Furthermore, addition of 0.5 mM sodium nitroprusside (SNP, a NO-releasing compound) substantially induced the anthocyanin accumulation, and H2O2-induced anthocyanin accumulation and UVR8 expression were significantly suppressed by co-treatment with 2-phenyl-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl (PTIO, a NO scavenger), which was parallel with the expression of anthocyanin biosynthesis-related transcription factors and structural genes. All these results demonstrate that both H2O2 and NO are involved in UV-B-induced anthocyanin accumulation, and there is a crosstalk between them as well as a classical UVR8 pathway. PMID:27404993

  6. Hydrogen peroxide, nitric oxide and UV RESISTANCE LOCUS8 interact to mediate UV-B-induced anthocyanin biosynthesis in radish sprouts.

    PubMed

    Wu, Qi; Su, Nana; Zhang, Xiaoyan; Liu, Yuanyuan; Cui, Jin; Liang, Yongchao

    2016-01-01

    The cross talk among hydrogen peroxide (H2O2), nitric oxide (NO) and UV RESISTANCE LOCUS8 (UVR8) in UV-B-induced anthocyanin accumulation in the hypocotyls of radish sprouts was investigated. The results showed that UV-B irradiation significantly increased the anthocyanin accumulation and the expression of UVR8, and a similar trend appeared in radish sprouts subjected to cadmium, chilling and salt stresses regardless of light source. However, these responses disappeared under dark exposure. These results suggest that abiotic stress-induced anthocyanin accumulation and UVR8 expression were light-dependent. Moreover, abiotic stresses all enhanced the production of H2O2 and exogenous H2O2 addition significantly increased the anthocyanin concentration and UVR8 transcription, while these increases were severely inhibited by addition of dimethylthiourea (DMTU, a chemical trap for H2O2). It seems to suggest that H2O2 played an important role in the anthocyanin biosynthesis. Furthermore, addition of 0.5 mM sodium nitroprusside (SNP, a NO-releasing compound) substantially induced the anthocyanin accumulation, and H2O2-induced anthocyanin accumulation and UVR8 expression were significantly suppressed by co-treatment with 2-phenyl-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl (PTIO, a NO scavenger), which was parallel with the expression of anthocyanin biosynthesis-related transcription factors and structural genes. All these results demonstrate that both H2O2 and NO are involved in UV-B-induced anthocyanin accumulation, and there is a crosstalk between them as well as a classical UVR8 pathway.

  7. Hydrogen peroxide, nitric oxide and UV RESISTANCE LOCUS8 interact to mediate UV-B-induced anthocyanin biosynthesis in radish sprouts.

    PubMed

    Wu, Qi; Su, Nana; Zhang, Xiaoyan; Liu, Yuanyuan; Cui, Jin; Liang, Yongchao

    2016-01-01

    The cross talk among hydrogen peroxide (H2O2), nitric oxide (NO) and UV RESISTANCE LOCUS8 (UVR8) in UV-B-induced anthocyanin accumulation in the hypocotyls of radish sprouts was investigated. The results showed that UV-B irradiation significantly increased the anthocyanin accumulation and the expression of UVR8, and a similar trend appeared in radish sprouts subjected to cadmium, chilling and salt stresses regardless of light source. However, these responses disappeared under dark exposure. These results suggest that abiotic stress-induced anthocyanin accumulation and UVR8 expression were light-dependent. Moreover, abiotic stresses all enhanced the production of H2O2 and exogenous H2O2 addition significantly increased the anthocyanin concentration and UVR8 transcription, while these increases were severely inhibited by addition of dimethylthiourea (DMTU, a chemical trap for H2O2). It seems to suggest that H2O2 played an important role in the anthocyanin biosynthesis. Furthermore, addition of 0.5 mM sodium nitroprusside (SNP, a NO-releasing compound) substantially induced the anthocyanin accumulation, and H2O2-induced anthocyanin accumulation and UVR8 expression were significantly suppressed by co-treatment with 2-phenyl-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl (PTIO, a NO scavenger), which was parallel with the expression of anthocyanin biosynthesis-related transcription factors and structural genes. All these results demonstrate that both H2O2 and NO are involved in UV-B-induced anthocyanin accumulation, and there is a crosstalk between them as well as a classical UVR8 pathway. PMID:27404993

  8. Bactericidal effect of hydrogen peroxide on spacecraft isolates

    NASA Technical Reports Server (NTRS)

    Wardle, M. D.; Renninger, G. M.

    1975-01-01

    Results are presented for an experimental study designed to assess the effect of hydrogen peroxide on both sporeforming and nonsporeforming spacecraft isolates as an initial step in determining its suitability for microbiological decontamination of certain United States spacecraft. Survivor data were obtained for eight bacterial isolates (six sporeformers and two nonsporeformers) recovered before launch Mariner 9 and exposed to concentrations of 3, 10, and 15% hydrogen peroxide. The effects of various concentrations of hydrogen peroxide on the spores are presented in tabular form, along with the percentage of survival of nonsporeformers exposed to hydrogen peroxide. No viable vegetative cells were recovered after a 10-min exposure time to any of the three concentration of hydrogen peroxide.

  9. Esculetin-induced protection of human hepatoma HepG2 cells against hydrogen peroxide is associated with the Nrf2-dependent induction of the NAD(P)H: Quinone oxidoreductase 1 gene

    SciTech Connect

    Subramaniam, Sudhakar R.; Ellis, Elizabeth M.

    2011-01-15

    Esculetin (6,7-dihydroxy coumarin), is a potent antioxidant that is present in several plant species. The aim of this study was to investigate the mechanism of protection of esculetin in human hepatoma HepG2 cells against reactive oxygen species (ROS) induced by hydrogen peroxide. Cell viability, cell integrity, intracellular glutathione levels, generation of reactive oxygen species and expression of antioxidant enzymes were used as markers to measure cellular oxidative stress and response to ROS. The protective effect of esculetin was compared to a well-characterized chemoprotective compound quercetin. Pre-treatment of HepG2 cells with sub-lethal (10-25 {mu}M) esculetin for 8 h prevented cell death and maintained cell integrity following exposure to 0.9 mM hydrogen peroxide. An increase in the generation of ROS following hydrogen peroxide treatment was significantly attenuated by 8 h pre-treatment with esculetin. In addition, esculetin ameliorated the decrease in intracellular glutathione caused by hydrogen peroxide exposure. Moreover, treatment with 25 {mu}M esculetin for 8 h increased the expression of NAD(P)H: quinone oxidoreductase (NQO1) at both protein and mRNA levels significantly, by 12-fold and 15-fold, respectively. Esculetin treatment also increased nuclear accumulation of Nrf2 by 8-fold indicating that increased NQO1 expression is Nrf2-mediated. These results indicate that esculetin protects human hepatoma HepG2 cells from hydrogen peroxide induced oxidative injury and that this protection is provided through the induction of protective enzymes as part of an adaptive response mediated by Nrf2 nuclear accumulation.

  10. Synchronized expression of two caspase family genes, ice-2 and ice-5, in hydrogen peroxide-induced cells of the silkworm, Bombyx mori.

    PubMed

    Sun, Y; Wang, W; Li, B; Wu, Y; Wu, H; Shen, W

    2010-01-01

    Caspase family proteins play important roles in different stages of the apoptotic pathway. To date, however, functions of Bombyx mori L. (Lepidoptera: Bombycidae) caspase family genes are poorly known. This paper focuses on the morphology, mitochondrial membrane potential, and expression profiles of two novel B. mori caspase family genes (ice-2 and ice-5) in 3 microM hydrogen peroxide (H2O2) damaged B. mori cells, which were separated from the ovary of B. mori. In addition, comparisons were made between damage caused by H2O2 and by ultraviolet (UV) irradiation. The results showed that the potential change of the mitochondrial membrane occurred at 0.5 h after H2O2 stimulation, which was sooner than occurred in the UV treated model where the obvious decrease appeared at 6 h after stimulation. In addition, the total change in the potential of the mitochondrial membrane in H2O2 treated B. mori cells was larger than with UV treated cells during the whole process. Analysis of fluorescent quantitative real-time PCR demonstrated that ice-2 and ice-5 might be involved in both H2O2 and UV-induced apoptosis in B. mori cells. Notably, after exposure to H2O2, the expression patterns of ice-5 were remarkably higher than those of ice-2, while the result was the opposite after exposure to UV irradiation. The data indicate that apoptosis induced by H2O2 was directly related to the mitochondrial pathway. The two isoforms of B. mori ice may play different roles in the mitochondrion associated apoptotic pathway in B. mori cells, and the apoptotic pathway in H2O2 induced B. mori cells is different from the UV induced apoptotic pathway.

  11. Hydrogen peroxide as a signal controlling plant programmed cell death

    PubMed Central

    Gechev, Tsanko S.; Hille, Jacques

    2005-01-01

    Hydrogen peroxide (H2O2) has established itself as a key player in stress and programmed cell death responses, but little is known about the signaling pathways leading from H2O2 to programmed cell death in plants. Recently, identification of key regulatory mutants and near-full genome coverage microarray analysis of H2O2-induced cell death have begun to unravel the complexity of the H2O2 network. This review also describes a novel link between H2O2 and sphingolipids, two signals that can interplay and regulate plant cell death. PMID:15631987

  12. Hydrogen Peroxide-Induced Inhibition of Vasomotor Activity: Evaluation of Single and Combined Treatments With Vitamin A and Insulin in Streptozotocin-Diabetic Rats

    PubMed Central

    Zobali, Fulya; Besler, Tanju; Ari, Nuray

    2002-01-01

    A positive correlation has been established between increased oxidative stress and cardiovascular diseases in diabetes mellitus. We evaluated the effects of single or combined treatments with vitamin A (retinol acetate, 30 mg/kg/day, for 12-weeks) and insulin (8-10 IU/rat/day for the final 6-week) on vasomotor activity, oxidative stress and retinol metabolism in 12-week streptozotocin diabetic rats. The vasomotor activity was determined by measuring in vitro responsiveness of aorta rings to phenylephrine (PE) and acetylcholine (ACh) in the absence or in the presence of hydrogen peroxide (H2O2). Preincubation with H2O2 (10 μM) produced a significant decrease in PE (1 mM)-induced contraction in untreated-diabetic but not in control rats. Single treatment with insulin counteracted this effect of H2O2 and also reversed the increased contractile response of diabetic aorta to PE, while vitamin A was found to be ineffective. H2O2 (10 μM) also inhibited ACh (1 mM)-stimulated endothelium- dependent relaxation two fold more in diabetic than in control aorta. In the prevention of H2O2-induced inhibition of vascular relaxation to ACh, vitamin A alone was markedly effective while insulin alone was not. The combination of vitamin A plus insulin removed the inhibitory action of H2O2 in diabetic aorta. Diabetic animals displayed an increased level of aorta thiobarbituric acid reactive substance (TBARS) in association with decreased levels of plasma retinol and retinol-binding protein (RBP). Single treatment with insulin, in spite of allowing recovery of normal growth rate and improved glucose and retinol metabolism in diabetic rats, was unable to control TBARS production to the same extent as vitamin A alone. Our findings suggest that the maintenance of ACh-stimulated endothelium-dependent vasorelaxant tone in normal physiological levels depends largely on the prevention and/or inhibition of peroxidative stress, which is achieved by combined treatment with vitamin A plus insulin

  13. Modulation of Hydrogen Peroxide-Induced Oxidative Stress in Human Neuronal Cells by Thymoquinone-Rich Fraction and Thymoquinone via Transcriptomic Regulation of Antioxidant and Apoptotic Signaling Genes

    PubMed Central

    Ismail, Norsharina; Ismail, Maznah; Azmi, Nur Hanisah; Abu Bakar, Muhammad Firdaus; Basri, Hamidon; Abdullah, Maizaton Atmadini

    2016-01-01

    Nigella sativa Linn. (N. sativa) and its bioactive constituent Thymoquinone (TQ) have demonstrated numerous pharmacological attributes. In the present study, the neuroprotective properties of Thymoquinone-rich fraction (TQRF) and TQ against hydrogen peroxide- (H2O2-) induced neurotoxicity in differentiated human SH-SY5Y cells were investigated. TQRF was extracted using supercritical fluid extraction while TQ was acquired commercially, and their effects on H2O2 were evaluated using cell viability assay, reactive oxygen species (ROS) assay, morphological observation, and multiplex gene expression. Both TQRF and TQ protected the cells against H2O2 by preserving the mitochondrial metabolic enzymes, reducing intracellular ROS levels, preserving morphological architecture, and modulating the expression of genes related to antioxidants (SOD1, SOD2, and catalase) and signaling genes (p53, AKT1, ERK1/2, p38 MAPK, JNK, and NF-κβ). In conclusion, the enhanced efficacy of TQRF over TQ was likely due to the synergism of multiple constituents in TQRF. The efficacy of TQRF was better than that of TQ alone when equal concentrations of TQ in TQRF were compared. In addition, TQRF also showed comparable effects to TQ when the same concentrations were tested. These findings provide further support for the use of TQRF as an alternative to combat oxidative stress insults in neurodegenerative diseases. PMID:26823946

  14. Enzyme-Treated Asparagus Extract Attenuates Hydrogen Peroxide-Induced Matrix Metalloproteinase-9 Expression in Murine Skin Fibroblast L929 Cells.

    PubMed

    Shirato, Ken; Takanari, Jun; Ogasawara, Junetsu; Sakurai, Takuya; Imaizumi, Kazuhiko; Ohno, Hideki; Kizaki, Takako

    2016-05-01

    Enzyme-treated asparagus extract (ETAS) exerts a wide variety of beneficial biological actions including facilitating anti-cortisol stress and neurological anti-aging responses. However, the anti-skin aging effects of ETAS remain to be elucidated. Reactive oxygen species (ROS) play pivotal roles in skin aging. Increased ROS levels in fibroblasts in response to ultraviolet irradiation activate c-Jun N-terminal kinase (JNK) and its downstream transcription factor activator protein-1 (AP-1), and the resultant gene expression of matrix metalloproteinase (MMP) isoforms accelerates collagen breakdown in the dermis. Therefore, we explored whether ETAS has anti-skin aging effects by attenuating the oxidative stress responses in fibroblasts. Simultaneous treatment of murine skin L929 fibroblasts with hydrogen peroxide (H2O2) and either ETAS or dextrin showed that ETAS significantly suppressed H2O2-induced expression of MMP-9 mRNA as measured by real-time polymerase chain reaction. ETAS also clearly suppressed H2O2-stimulated phosphorylation of c-Jun (AP-1 subunit) and JNK as determined by Western blot. However, ETAS did not affect the increased amounts of carbonyl proteins in response to H2O2, also as determined by Western blotting. These results suggest that ETAS diminishes cellular responsiveness to ROS but does not scavenge ROS. Thus, ETAS has the potential to prevent skin aging through attenuating the oxidative stress responses in dermal fibroblasts. PMID:27319149

  15. Modulation of Hydrogen Peroxide-Induced Oxidative Stress in Human Neuronal Cells by Thymoquinone-Rich Fraction and Thymoquinone via Transcriptomic Regulation of Antioxidant and Apoptotic Signaling Genes.

    PubMed

    Ismail, Norsharina; Ismail, Maznah; Azmi, Nur Hanisah; Abu Bakar, Muhammad Firdaus; Basri, Hamidon; Abdullah, Maizaton Atmadini

    2016-01-01

    Nigella sativa Linn. (N. sativa) and its bioactive constituent Thymoquinone (TQ) have demonstrated numerous pharmacological attributes. In the present study, the neuroprotective properties of Thymoquinone-rich fraction (TQRF) and TQ against hydrogen peroxide- (H2O2-) induced neurotoxicity in differentiated human SH-SY5Y cells were investigated. TQRF was extracted using supercritical fluid extraction while TQ was acquired commercially, and their effects on H2O2 were evaluated using cell viability assay, reactive oxygen species (ROS) assay, morphological observation, and multiplex gene expression. Both TQRF and TQ protected the cells against H2O2 by preserving the mitochondrial metabolic enzymes, reducing intracellular ROS levels, preserving morphological architecture, and modulating the expression of genes related to antioxidants (SOD1, SOD2, and catalase) and signaling genes (p53, AKT1, ERK1/2, p38 MAPK, JNK, and NF-κβ). In conclusion, the enhanced efficacy of TQRF over TQ was likely due to the synergism of multiple constituents in TQRF. The efficacy of TQRF was better than that of TQ alone when equal concentrations of TQ in TQRF were compared. In addition, TQRF also showed comparable effects to TQ when the same concentrations were tested. These findings provide further support for the use of TQRF as an alternative to combat oxidative stress insults in neurodegenerative diseases. PMID:26823946

  16. Enzyme-Treated Asparagus Extract Attenuates Hydrogen Peroxide-Induced Matrix Metalloproteinase-9 Expression in Murine Skin Fibroblast L929 Cells.

    PubMed

    Shirato, Ken; Takanari, Jun; Ogasawara, Junetsu; Sakurai, Takuya; Imaizumi, Kazuhiko; Ohno, Hideki; Kizaki, Takako

    2016-05-01

    Enzyme-treated asparagus extract (ETAS) exerts a wide variety of beneficial biological actions including facilitating anti-cortisol stress and neurological anti-aging responses. However, the anti-skin aging effects of ETAS remain to be elucidated. Reactive oxygen species (ROS) play pivotal roles in skin aging. Increased ROS levels in fibroblasts in response to ultraviolet irradiation activate c-Jun N-terminal kinase (JNK) and its downstream transcription factor activator protein-1 (AP-1), and the resultant gene expression of matrix metalloproteinase (MMP) isoforms accelerates collagen breakdown in the dermis. Therefore, we explored whether ETAS has anti-skin aging effects by attenuating the oxidative stress responses in fibroblasts. Simultaneous treatment of murine skin L929 fibroblasts with hydrogen peroxide (H2O2) and either ETAS or dextrin showed that ETAS significantly suppressed H2O2-induced expression of MMP-9 mRNA as measured by real-time polymerase chain reaction. ETAS also clearly suppressed H2O2-stimulated phosphorylation of c-Jun (AP-1 subunit) and JNK as determined by Western blot. However, ETAS did not affect the increased amounts of carbonyl proteins in response to H2O2, also as determined by Western blotting. These results suggest that ETAS diminishes cellular responsiveness to ROS but does not scavenge ROS. Thus, ETAS has the potential to prevent skin aging through attenuating the oxidative stress responses in dermal fibroblasts.

  17. Frozen fruit pulp of Euterpe oleraceae Mart. (Acai) prevents hydrogen peroxide-induced damage in the cerebral cortex, cerebellum, and hippocampus of rats.

    PubMed

    Spada, Patricia D S; Dani, Caroline; Bortolini, Giovana V; Funchal, Claudia; Henriques, João A P; Salvador, Mirian

    2009-10-01

    Oxidative stress is implicated in several human illnesses, including neurological disorders such as Parkinson's and Alzheimer's diseases. Acai is largely consumed in Brazil and contains high levels of antioxidant compounds. This work aims to study the antioxidant activity of acai frozen fruit pulp in the cerebral cortex, hippocampus, and cerebellum of rats treated with the oxidizing agent hydrogen peroxide (H(2)O(2)). Pretreatment of tissue with acai decreased H(2)O(2)-induced damage of both lipids and proteins in all tissues tested. This fruit was also able to reduce the activities of the antioxidant enzymes superoxide dismutase and catalase to basal levels. We observed a negative correlation between the polyphenol content of acai and the levels of lipid (r = -0.689; P

  18. Kohlrabi-based amperometric biosensor for hydrogen peroxide measurement

    SciTech Connect

    Lu Chen; Meng Shan Lin; Hara, Minoru; Rechnitz, G.A. )

    1991-01-01

    Hydrogen peroxide is a very important substance both in biological and environmental reactions. Hydrogen peroxide was determined amperometrically in a steady-state arrangement by utilizing a kohlrabi-ferrocene based carbon paste electrode. A very short response time (2.6 seconds) and a relatively large usable pH range (5.0-7.4) were obtained. Several important hydrogen donors were studied as possible interferences.

  19. Enhanced sensitivity to hydrogen peroxide-induced apoptosis in Evi1 transformed Rat1 fibroblasts due to repression of carbonic anhydrase III.

    PubMed

    Roy, P; Reavey, E; Rayne, M; Roy, S; Abed El Baky, M; Ishii, Y; Bartholomew, C

    2010-01-01

    EVI1 is a nuclear zinc finger protein essential to normal development, which participates in acute myeloid leukaemia progression and transforms Rat1 fibroblasts. In this study we show that enforced expression of Evi1 in Rat1 fibroblasts protects from paclitaxel-induced apoptosis, consistent with previously published studies. Surprisingly, however, these cells show increased sensitivity to hydrogen peroxide (H(2)O(2))-induced apoptosis, demonstrated by elevated caspase 3 catalytic activity. This effect is caused by a reduction in carbonic anhydrase III (caIII) production. caIII transcripts are repressed by 92-97% by Evi1 expression, accompanied by a similar reduction in caIII protein. Reporter assays with the rat caIII gene promoter show repressed activity, demonstrating that Evi1 either directly or indirectly modulates transcription of this gene in Rat1 cells. Targeted knockdown of caIII alone, with Dicer-substrate short inhibitory RNAs, also increases the sensitivity of Rat1 fibroblasts to H(2)O(2), which occurs in the absence of any other changes mediated by Evi1 expression. Enforced expression of caIII in Evi1-expressing Rat1 cells reverts the phenotype, restoring H(2)O(2) resistance. Together these data show that Evi1 represses transcription of caIII gene expression, leading to increased sensitivity to H(2)O(2)-induced apoptosis in Rat1 cells and might suggest the basis for the development of a novel therapeutic strategy for the treatment of leukaemias and solid tumours where EVI1 is overexpressed.

  20. Bimodal effect of hydrogen peroxide and oxidative events in nitrite-induced rapid root abscission by the water fern Azolla pinnata

    DOE PAGESBeta

    Cohen, Michael F.; Gurung, Sushma; Birarda, Giovanni; Holman, Hoi-Ying N.; Yamasaki, Hideo

    2015-07-09

    In the genus Azolla rapid abscission of roots from floating fronds occurs within minutes in response to a variety of stresses, including exposure to nitrite. We found that hydrogen peroxide, though itself not an inducer of root abscission, modulates nitrite-induced root abscission by Azolla pinnata in a dose-dependent manner, with 2 mM H2O2 significantly diminishing the responsiveness to 2 mM NaNO2, and 10 mM H2O2 slightly enhancing it. Hypoxia, which has been found in other plants to result in autogenic production of H2O2, dramatically stimulated root abscission of A. pinnata in response to nitrite, especially for plants previously cultivated inmore » medium containing 5 mM KNO3 compared to plants cultivated under N2-fixing conditions without combined nitrogen. Plants, including Azolla, produce the small signaling molecule nitric oxide (NO) from nitrite using nitrate reductase. We found Azolla plants to display dose-dependent root abscission in response to the NO donor spermine NONOate. Treatment of plants with the thiol-modifying agents S-methyl methanethiosulfonate or glutathione inhibited the nitrite-induced root abscission response. Synchrotron radiation-based Fourier transform infrared spectromicroscopy revealed higher levels of carbonylation in the abscission zone of dropped roots, indicative of reaction products of polysaccharides with potent free radical oxidants. Lastly, we hypothesize that metabolic products of nitrite and NO react with H2O2 in the apoplast leading to free-radical-mediated cleavage of structural polysaccharides and consequent rapid root abscission.« less

  1. Bimodal effect of hydrogen peroxide and oxidative events in nitrite-induced rapid root abscission by the water fern Azolla pinnata

    SciTech Connect

    Cohen, Michael F.; Gurung, Sushma; Birarda, Giovanni; Holman, Hoi-Ying N.; Yamasaki, Hideo

    2015-07-09

    In the genus Azolla rapid abscission of roots from floating fronds occurs within minutes in response to a variety of stresses, including exposure to nitrite. We found that hydrogen peroxide, though itself not an inducer of root abscission, modulates nitrite-induced root abscission by Azolla pinnata in a dose-dependent manner, with 2 mM H2O2 significantly diminishing the responsiveness to 2 mM NaNO2, and 10 mM H2O2 slightly enhancing it. Hypoxia, which has been found in other plants to result in autogenic production of H2O2, dramatically stimulated root abscission of A. pinnata in response to nitrite, especially for plants previously cultivated in medium containing 5 mM KNO3 compared to plants cultivated under N2-fixing conditions without combined nitrogen. Plants, including Azolla, produce the small signaling molecule nitric oxide (NO) from nitrite using nitrate reductase. We found Azolla plants to display dose-dependent root abscission in response to the NO donor spermine NONOate. Treatment of plants with the thiol-modifying agents S-methyl methanethiosulfonate or glutathione inhibited the nitrite-induced root abscission response. Synchrotron radiation-based Fourier transform infrared spectromicroscopy revealed higher levels of carbonylation in the abscission zone of dropped roots, indicative of reaction products of polysaccharides with potent free radical oxidants. Lastly, we hypothesize that metabolic products of nitrite and NO react with H2O2 in the apoplast leading to free-radical-mediated cleavage of structural polysaccharides and consequent rapid root abscission.

  2. Protective effects of Semiaquilegia adoxoides n-butanol extract against hydrogen peroxide-induced oxidative stress in human lens epithelial cells.

    PubMed

    Liang, Bing; Wei, Wei; Wang, Jianta; Zhang, Mingming; Xu, Ran; Wu, Fei; Xiao, Haitao; Tang, Lei

    2016-09-01

    Context Hydrogen peroxide (H2O2)-induced damage in the lens epithelium leads to cell death and cataract. Semiaquilegia adoxoides (DC.) Makino (Ranunculaceae), a folk medicine of Hmong (an ethnic group of China), has been traditionally used to treat cataract; however, the underlying molecular mechanism is yet to be uncovered. Objective This study aimed to investigate whether the n-butanol extract of S. adoxoides (nSA) is effective against the H2O2-induced oxidative stress in human lens epithelial (HLE) cells. Materials and methods Human lens epithelial (SRA 01/04) cells were stimulated by H2O2 (250 μM) in the presence or absence of nSA. The antioxidant effects of nSA were determined in terms of cell viability (MTT assay), apoptosis (AnnexinV/PI staining), radical scavenging capability (various enzymatic assays), loss of mitochondrial membrane potential (Rhodamine 123 staining), expression of apoptotic markers including caspase-3 and caspase-9 and the change of Bcl-2/Bax ratio (western blot) in the HLE cells. Results The results showed that pretreatment of nSA (250, 500 and 1000 μg/mL) markedly reduced H2O2-induced cellular apoptosis and malondialdehyde accumulation, but elevated the activities of total superoxide dismutase, catalase, glutathione peroxidase. Thus, the total antioxidative capability was enhanced upon the nSA treatment meanwhile the loss of mitochondrial membrane potential was prevented. Moreover, nSA at concentrations of 250, 500 and 1000 μg/mL also significantly suppressed the activation of caspase-3 and -9, and increased the Bcl-2/Bax ratio in the HLE cells. Discussion and conclusion Our findings suggested that nSA is a potential prophylactic agent in the prevention of cataractogeneis.

  3. 1,4-Benzenediboronic-Acid-Induced Aggregation of Gold Nanoparticles: Application to Hydrogen Peroxide Detection and Biotin-Avidin-Mediated Immunoassay with Naked-Eye Detection.

    PubMed

    Yang, Ya-Chun; Tseng, Wei-Lung

    2016-05-17

    Hydrogen-peroxide (H2O2)-induced growth of small-sized gold nanoparticles (AuNPs) is often implemented for H2O2 sensing and plasmonic immunoassay. In contrast, there is little-to-no information in the literature regarding the application of H2O2-inhibited aggregation of citrate-capped AuNPs. This study discloses that benzene-1,4-diboronic acid (BDBA) was effective in driving the aggregation of citrate-capped AuNPs through an interaction between α-hydroxycarboxylate of citrate and boronic acids of BDBA. The H2O2-mediated oxidation of BDBA resulted in the conversion of boronic acid groups to phenol groups. The oxidized BDBA was incapable of triggering the aggregation of citrate-capped AuNPs. Thus, the presence of H2O2 prohibited BDBA-induced aggregation of citrate-capped AuNPs. The BDBA-induced aggregation of citrate-capped AuNPs can be paired with the glucose oxidase (GOx)-glucose system to design a colorimetric probe for glucose. Moreover, a H2O2·BDBA·AuNP probe was integrated with sandwich immunoassay, biotinylated antibody, and avidin-conjugated GOx for the selective naked-eye detection of rabbit immunoglobulin G (IgG) and human-prostate-specific antigen (PSA). The lowest detectable concentrations of rabbit IgG and human PSA by the naked eye were down to 0.1 and 4 ng/mL, respectively. More importantly, the proposed plasmonic immunoassay allowed the naked-eye quantification of 0-10 ng/mL PSA at an interval of 2 ng/mL in plasma samples.

  4. Bimodal effect of hydrogen peroxide and oxidative events in nitrite-induced rapid root abscission by the water fern Azolla pinnata

    PubMed Central

    Cohen, Michael F.; Gurung, Sushma; Birarda, Giovanni; Holman, Hoi-Ying N.; Yamasaki, Hideo

    2015-01-01

    In the genus Azolla rapid abscission of roots from floating fronds occurs within minutes in response to a variety of stresses, including exposure to nitrite. We found that hydrogen peroxide, though itself not an inducer of root abscission, modulates nitrite-induced root abscission by Azolla pinnata in a dose-dependent manner, with 2 mM H2O2 significantly diminishing the responsiveness to 2 mM NaNO2, and 10 mM H2O2 slightly enhancing it. Hypoxia, which has been found in other plants to result in autogenic production of H2O2, dramatically stimulated root abscission of A. pinnata in response to nitrite, especially for plants previously cultivated in medium containing 5 mM KNO3 compared to plants cultivated under N2-fixing conditions without combined nitrogen. Plants, including Azolla, produce the small signaling molecule nitric oxide (NO) from nitrite using nitrate reductase. We found Azolla plants to display dose-dependent root abscission in response to the NO donor spermine NONOate. Treatment of plants with the thiol-modifying agents S-methyl methanethiosulfonate or glutathione inhibited the nitrite-induced root abscission response. Synchrotron radiation-based Fourier transform infrared spectromicroscopy revealed higher levels of carbonylation in the abscission zone of dropped roots, indicative of reaction products of polysaccharides with potent free radical oxidants. We hypothesize that metabolic products of nitrite and NO react with H2O2 in the apoplast leading to free-radical-mediated cleavage of structural polysaccharides and consequent rapid root abscission. PMID:26217368

  5. 1,4-Benzenediboronic-Acid-Induced Aggregation of Gold Nanoparticles: Application to Hydrogen Peroxide Detection and Biotin-Avidin-Mediated Immunoassay with Naked-Eye Detection.

    PubMed

    Yang, Ya-Chun; Tseng, Wei-Lung

    2016-05-17

    Hydrogen-peroxide (H2O2)-induced growth of small-sized gold nanoparticles (AuNPs) is often implemented for H2O2 sensing and plasmonic immunoassay. In contrast, there is little-to-no information in the literature regarding the application of H2O2-inhibited aggregation of citrate-capped AuNPs. This study discloses that benzene-1,4-diboronic acid (BDBA) was effective in driving the aggregation of citrate-capped AuNPs through an interaction between α-hydroxycarboxylate of citrate and boronic acids of BDBA. The H2O2-mediated oxidation of BDBA resulted in the conversion of boronic acid groups to phenol groups. The oxidized BDBA was incapable of triggering the aggregation of citrate-capped AuNPs. Thus, the presence of H2O2 prohibited BDBA-induced aggregation of citrate-capped AuNPs. The BDBA-induced aggregation of citrate-capped AuNPs can be paired with the glucose oxidase (GOx)-glucose system to design a colorimetric probe for glucose. Moreover, a H2O2·BDBA·AuNP probe was integrated with sandwich immunoassay, biotinylated antibody, and avidin-conjugated GOx for the selective naked-eye detection of rabbit immunoglobulin G (IgG) and human-prostate-specific antigen (PSA). The lowest detectable concentrations of rabbit IgG and human PSA by the naked eye were down to 0.1 and 4 ng/mL, respectively. More importantly, the proposed plasmonic immunoassay allowed the naked-eye quantification of 0-10 ng/mL PSA at an interval of 2 ng/mL in plasma samples. PMID:27091002

  6. miR-21 Reduces Hydrogen Peroxide-Induced Apoptosis in c-kit+ Cardiac Stem Cells In Vitro through PTEN/PI3K/Akt Signaling

    PubMed Central

    Wang, Yan; Long, Xianping; Zhao, Ranzun; Wang, Zhenglong; Liu, Zhijiang

    2016-01-01

    The low survival rate of cardiac stem cells (CSCs) in the infarcted myocardium hampers cell therapy for ischemic cardiomyopathy. MicroRNA-21 (miR-21) and one of its target proteins, PTEN, contribute to the survival and proliferation of many cell types, but their prosurvival effects in c-kit+ CSC remain unclear. Thus, we hypothesized that miR-21 reduces hydrogen peroxide- (H2O2-) induced apoptosis in c-kit+ CSC and estimated the contribution of PTEN/PI3K/Akt signaling to this oxidative circumstance. miR-21 mimics efficiently reduced H2O2-induced apoptosis in c-kit+ CSC, as evidenced by the downregulation of the proapoptosis proteins caspase-3 and Bax and upregulation of the antiapoptotic Bcl-2. In addition, the gain of function of miR-21 in c-kit+ CSC downregulated the protein level of PTEN although its mRNA level changed slightly; in the meantime, miR-21 overexpression also increased phospho-Akt (p-Akt). The antiapoptotic effects of miR-21 were comparable with Phen (bpV), the selective inhibitor of PTEN, while miR-21 inhibitor or PI3K's inhibitor LY294002 efficiently attenuated the antiapoptotic effect of miR-21. Taken together, these results indicate that the anti-H2O2-induced apoptosis effect of miR-21 in c-kit+ CSC is contributed by PTEN/PI3K/Akt signaling. miR-21 could be a potential molecule to facilitate the c-kit+ CSC therapy in ischemic myocardium. PMID:27803763

  7. Hydrogen peroxide stimulates cell motile activity through LPA receptor-3 in liver epithelial WB-F344 cells

    SciTech Connect

    Shibata, Ayano; Tanabe, Eriko; Inoue, Serina; Kitayoshi, Misaho; Okimoto, Souta; Hirane, Miku; Araki, Mutsumi; Fukushima, Nobuyuki; Tsujiuchi, Toshifumi

    2013-04-12

    Highlights: •Hydrogen peroxide stimulates cell motility of WB-F344 cells. •LPA{sub 3} is induced by hydrogen peroxide in WB-F344 cells. •Cell motility by hydrogen peroxide is inhibited in LPA{sub 3} knockdown cells. •LPA signaling is involved in cell migration by hydrogen peroxide. -- Abstract: Hydrogen peroxide which is one of reactive oxygen species (ROS) mediates a variety of biological responses, including cell proliferation and migration. In the present study, we investigated whether lysophosphatidic acid (LPA) signaling is involved in cell motile activity stimulated by hydrogen peroxide. The rat liver epithelial WB-F344 cells were treated with hydrogen peroxide at 0.1 or 1 μM for 48 h. In cell motility assays, hydrogen peroxide treated cells showed significantly high cell motile activity, compared with untreated cells. To measure the expression levels of LPA receptor genes, quantitative real time RT-PCR analysis was performed. The expressions of LPA receptor-3 (Lpar3) in hydrogen peroxide treated cells were significantly higher than those in control cells, but not Lpar1 and Lpar2 genes. Next, to assess the effect of LPA{sub 3} on cell motile activity, the Lpar3 knockdown cells from WB-F344 cells were also treated with hydrogen peroxide. The cell motile activity of the knockdown cells was not stimulated by hydrogen peroxide. Moreover, in liver cancer cells, hydrogen peroxide significantly activated cell motility of Lpar3-expressing cells, but not Lpar3-unexpressing cells. These results suggest that LPA signaling via LPA{sub 3} may be mainly involved in cell motile activity of WB-F344 cells stimulated by hydrogen peroxide.

  8. Kinetics of Platinum-Catalyzed Decomposition of Hydrogen Peroxide

    NASA Astrophysics Data System (ADS)

    Vetter, Tiffany A.; Colombo, D. Philip, Jr.

    2003-07-01

    CIBA Vision Corporation markets a contact lens cleaning system that consists of an AOSEPT disinfectant solution and an AOSEPT lens cup. The disinfectant is a buffered 3.0% m/v hydrogen peroxide solution and the cup includes a platinum-coated AOSEPT disc. The hydrogen peroxide disinfects by killing bacteria, fungi, and viruses found on the contact lenses. Because the concentration of hydrogen peroxide needed to disinfect is irritating to eyes, the hydrogen peroxide needs to be neutralized, or decomposed, before the contact lenses can be used again. A general chemistry experiment is described where the kinetics of the catalyzed decomposition of the hydrogen peroxide are studied by measuring the amount of oxygen generated as a function of time. The order of the reaction with respect to the hydrogen peroxide, the rate constant, and the energy of activation are determined. The integrated rate law is used to determine the time required to decompose the hydrogen peroxide to a concentration that is safe for eyes.

  9. One-pot hydrogen peroxide and hydrohalic acid induced ring closure and selective aromatic halogenation to give new ring-fused benzimidazoles.

    PubMed

    Gurry, Michael; Sweeney, Martin; McArdle, Patrick; Aldabbagh, Fawaz

    2015-06-01

    A new series of selectively dichlorinated and dibrominated five- to eight-membered-ring [1,2-a]-fused benzimidazoles and [1,4]oxazino[4,3-a]benzimidazoles are synthesized in mostly high yields of >80% using the reaction of hydrogen peroxide and hydrohalic acid with commercially available o-cyclic amine substituted anilines. Domestic bleach with HCl can also be used for a one-pot ring closure and chlorination.

  10. Beta-nodavirus B2 protein induces hydrogen peroxide production, leading to Drp1-recruited mitochondrial fragmentation and cell death via mitochondrial targeting.

    PubMed

    Su, Yu C; Chiu, Hsuan W; Hung, Jo C; Hong, Jiann R

    2014-10-01

    Because the role of the viral B2 protein in the pathogenesis of nervous necrosis virus infection remains unknown, the aim of the present study was to determine the effects of B2 protein on hydrogen peroxide (H2O2)-mediated cell death via mitochondrial targeting. Using a B2 deletion mutant, the B2 mitochondrial targeting signal sequence ((41)RTFVISAHAA(50)) correlated with mitochondrial free radical production and cell death in fish cells, embryonic zebrafish, and human cancer cells. After treatment of grouper fin cells (GF-1) overexpressing B2 protein with the anti-oxidant drug, N-acetylcysteine (NAC), and overexpression of the antioxidant enzymes, zfCu/Zn superoxide dismutase (SOD) and zfCatalase, decreased H2O2 production and cell death were observed. To investigate the correlation between B2 cytotoxicity and H2O2 production in vivo, B2 was injected into zebrafish embryos. Cell damage, as assessed by the acridine orange assay, gradually increased over 24 h post-fertilization, and was accompanied by marked increases in H2O2 production and embryonic death. Increased oxidative stress, as evidenced by the up-regulation of Mn SOD, catalase, and Nrf2, was also observed during this period. Finally, B2-induced dynamin-related protein 1 (Drp1)-mediated mitochondrial fragmentation and cell death could be reversed by NAC and inhibitors of Drp1 and Mdivi in GF-1 cells. Taken together, betanodavirus B2 induces H2O2 production via targeting the mitochondria, where it inhibits complex II function. H2O2 activates Drp1, resulting in its association with the mitochondria, mitochondrial fission and cell death in vitro and in vivo.

  11. Beta-nodavirus B2 protein induces hydrogen peroxide production, leading to Drp1-recruited mitochondrial fragmentation and cell death via mitochondrial targeting.

    PubMed

    Su, Yu C; Chiu, Hsuan W; Hung, Jo C; Hong, Jiann R

    2014-10-01

    Because the role of the viral B2 protein in the pathogenesis of nervous necrosis virus infection remains unknown, the aim of the present study was to determine the effects of B2 protein on hydrogen peroxide (H2O2)-mediated cell death via mitochondrial targeting. Using a B2 deletion mutant, the B2 mitochondrial targeting signal sequence ((41)RTFVISAHAA(50)) correlated with mitochondrial free radical production and cell death in fish cells, embryonic zebrafish, and human cancer cells. After treatment of grouper fin cells (GF-1) overexpressing B2 protein with the anti-oxidant drug, N-acetylcysteine (NAC), and overexpression of the antioxidant enzymes, zfCu/Zn superoxide dismutase (SOD) and zfCatalase, decreased H2O2 production and cell death were observed. To investigate the correlation between B2 cytotoxicity and H2O2 production in vivo, B2 was injected into zebrafish embryos. Cell damage, as assessed by the acridine orange assay, gradually increased over 24 h post-fertilization, and was accompanied by marked increases in H2O2 production and embryonic death. Increased oxidative stress, as evidenced by the up-regulation of Mn SOD, catalase, and Nrf2, was also observed during this period. Finally, B2-induced dynamin-related protein 1 (Drp1)-mediated mitochondrial fragmentation and cell death could be reversed by NAC and inhibitors of Drp1 and Mdivi in GF-1 cells. Taken together, betanodavirus B2 induces H2O2 production via targeting the mitochondria, where it inhibits complex II function. H2O2 activates Drp1, resulting in its association with the mitochondria, mitochondrial fission and cell death in vitro and in vivo. PMID:25008790

  12. Ac-cel, a novel antioxidant, protects against hydrogen peroxide-induced injury in PC12 cells via attenuation of mitochondrial dysfunction.

    PubMed

    Guo, Xianjun; Chen, Yuting; Liu, Qunfang; Wu, Jian; Wang, Luoyi; Tang, Xican; Zhao, Weimin; Zhang, Haiyan

    2013-07-01

    Oxidative stress has been implicated in pathophysiology of many neurodegenerative diseases (ND) and increased oxidative stress is closely associated with mitochondrial dysfunction. As a result, looking for potent antioxidants, especially those targeting mitochondria, has become an attractive strategy in ND therapy. In this study, we explored protective effects and potential mechanism of Ac-cel, a novel compound, against hydrogen peroxide (H(2)O(2))-induced injury in PC12 cells. Pretreatment of PC12 cells with Ac-cel prior to 24 h of H(2)O(2) exposure markedly attenuated cytotoxicity induced by H(2)O(2) as evidenced by morphological changes and 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Ac-cel also exhibited potent antiapoptotic effect demonstrated by results of annexin V and PI staining. The above beneficial effects of Ac-cel were accompanied by improved mitochondrial function, reduced caspase-3 cleavage as well as upregulated ratio of Bcl-2/Bax protein expression. Moreover, Ac-cel pretreatment markedly reversed intracellular reactive oxygen species (ROS) accumulation following 30 min of H(2)O(2) exposure in PC12 cells. Further, subcellular investigation indicated that Ac-cel significantly reduced production of mitochondrial ROS in isolated rat cortical mitochondria. Taken together, the present study, for the first time, reports that Ac-cel pretreatment inhibits H(2)O(2)-stimulated early accumulation of intracellular ROS possibly via reducing mitochondrial ROS production directly and leads to subsequent preservation of mitochondrial function. These results indicate that Ac-cel is a potential drug candidate for treatment of oxidative stress-associated ND.

  13. Exendin-4 protects adipose-derived mesenchymal stem cells from apoptosis induced by hydrogen peroxide through the PI3K/Akt-Sfrp2 pathways.

    PubMed

    Zhou, Hao; Yang, Junjie; Xin, Ting; Li, Dandan; Guo, Jun; Hu, Shunyin; Zhou, Shanshan; Zhang, Tao; Zhang, Ying; Han, Tianwen; Chen, Yundai

    2014-12-01

    Adipose-derived mesenchymal stem cells (ADMSCs)-based therapy is a promising modality for the treatment of myocardial infarction in the future. However, the majority of transplanted cells are readily lost after transplantation because of hypoxia and oxidative stress. An efficient means to enhance the ability of ADMSCs to survive under pathologic conditions is required. In our study, we explored the effects of exendin-4 (Ex-4) on ADMSCs apoptosis in vitro induced by hydrogen peroxide, focusing in particular on mitochondrial apoptotic pathways and PI3K/Akt-secreted frizzled-related protein 2 (Sfrp2) survival signaling. We demonstrated that ADMSCs subjected to H2O2 for 12h exhibited impaired mitochondrial function and higher apoptotic rate. However, Ex-4 (1-20 nM) preconditioning for 12h could protect ADMSCs against H2O2-mediated apoptosis in a dose-dependent manner. Furthermore, Ex-4 pretreatment upregulated the levels of superoxide dismutase and glutathione as well as downregulating the production of reactive oxygen species and malondialdehyde. Western blots revealed that increased antiapoptotic proteins Bcl-2 and c-IAP1/2 as well as decreased proapoptotic proteins Bax and cytochrome c appeared in ADMSCs with Ex-4 incubation, which inhibited the caspase-9-involved mitochondrial apoptosis pathways with evidence showing inactivation of caspase-9/3 and preservation of mitochondrial membrane potential. Furthermore, we illustrated that Ex-4 enhanced Akt phosphorylation, which increased the expression of Sfrp2. Notably, blockade of the PI3K/Akt pathway or knockdown of Sfrp2 with siRNA obviously abolished the protective effects of Ex-4 on mitochondrial function and ADMSCs apoptosis under H2O2. In summary, this study confirmed that H2O2 induced ADMSCs apoptosis through mitochondria-dependent cell death pathways, and Ex-4 preconditioning may reduce such apoptosis of ADMSCs through the PI3K/Akt-Sfrp2 pathways.

  14. Pectinase-treated Panax ginseng ameliorates hydrogen peroxide-induced oxidative stress in GC-2 sperm cells and modulates testicular gene expression in aged rats

    PubMed Central

    Kopalli, Spandana Rajendra; Cha, Kyu-Min; Jeong, Min-Sik; Lee, Sang-Ho; Sung, Jong-Hwan; Seo, Seok-Kyo; Kim, Si-Kwan

    2015-01-01

    Background To investigate the effect of pectinase-treated Panax ginseng (GINST) in cellular and male subfertility animal models. Methods Hydrogen peroxide (H2O2)-induced mouse spermatocyte GC-2spd cells were used as an in vitro model. Cell viability was measured using MTT assay. For the in vivo study, GINST (200 mg/kg) mixed with a regular pellet diet was administered orally for 4 mo, and the changes in the mRNA and protein expression level of antioxidative and spermatogenic genes in young and aged control rats were compared using real-time reverse transcription polymerase chain reaction and western blotting. Results GINST treatment (50 μg/mL, 100 μg/mL, and 200 μg/mL) significantly (p < 0.05) inhibited the H2O2-induced (200 μM) cytotoxicity in GC-2spd cells. Furthermore, GINST (50 μg/mL and 100 μg/mL) significantly (p < 0.05) ameliorated the H2O2-induced decrease in the expression level of antioxidant enzymes (peroxiredoxin 3 and 4, glutathione S-transferase m5, and glutathione peroxidase 4), spermatogenesis-related protein such as inhibin-α, and specific sex hormone receptors (androgen receptor, luteinizing hormone receptor, and follicle-stimulating hormone receptor) in GC-2spd cells. Similarly, the altered expression level of the above mentioned genes and of spermatogenesis-related nectin-2 and cAMP response element-binding protein in aged rat testes was ameliorated with GINST (200 mg/kg) treatment. Taken together, GINST attenuated H2O2-induced oxidative stress in GC-2 cells and modulated the expression of antioxidant-related genes and of spermatogenic-related proteins and sex hormone receptors in aged rats. Conclusion GINST may be a potential natural agent for the protection against or treatment of oxidative stress-induced male subfertility and aging-induced male subfertility. PMID:27158240

  15. Locating bomb factories by detecting hydrogen peroxide.

    PubMed

    Romolo, Francesco Saverio; Connell, Samantha; Ferrari, Carlotta; Suarez, Guillaume; Sauvain, Jean-Jacques; Hopf, Nancy B

    2016-11-01

    The analytical capability to detect hydrogen peroxide vapour can play a key role in localizing a site where a H2O2 based Improvised Explosive (IE) is manufactured. In security activities it is very important to obtain information in a short time. For this reason, an analytical method to be used in security activity needs portable devices. The authors have developed the first analytical method based on a portable luminometer, specifically designed and validated to locate IE manufacturing sites using quantitative on-site vapour analysis for H2O2. The method was tested both indoor and outdoor. The results demonstrate that the detection of H2O2 vapours could allow police forces to locate the site, while terrorists are preparing an attack. The collected data are also very important in developing new sensors, able to give an early alarm if located at a proper distance from a site where an H2O2 based IE is prepared. PMID:27591582

  16. Molecular evolution of hydrogen peroxide degrading enzymes.

    PubMed

    Zámocký, Marcel; Gasselhuber, Bernhard; Furtmüller, Paul G; Obinger, Christian

    2012-09-15

    For efficient removal of intra- and/or extracellular hydrogen peroxide by dismutation to harmless dioxygen and water (2H(2)O(2) → O(2) + 2H(2)O), nature designed three metalloenzyme families that differ in oligomeric organization, monomer architecture as well as active site geometry and catalytic residues. Here we report on the updated reconstruction of the molecular phylogeny of these three gene families. Ubiquitous typical (monofunctional) heme catalases are found in all domains of life showing a high structural conservation. Their evolution was directed from large subunit towards small subunit proteins and further to fused proteins where the catalase fold was retained but lost its original functionality. Bifunctional catalase-peroxidases were at the origin of one of the two main heme peroxidase superfamilies (i.e. peroxidase-catalase superfamily) and constitute a protein family predominantly present among eubacteria and archaea, but two evolutionary branches are also found in the eukaryotic world. Non-heme manganese catalases are a relatively small protein family with very old roots only present among bacteria and archaea. Phylogenetic analyses of the three protein families reveal features typical (i) for the evolution of whole genomes as well as (ii) for specific evolutionary events including horizontal gene transfer, paralog formation and gene fusion. As catalases have reached a striking diversity among prokaryotic and eukaryotic pathogens, understanding their phylogenetic and molecular relationship and function will contribute to drug design for prevention of diseases of humans, animals and plants. PMID:22330759

  17. Hydrogen peroxide diffusion dynamics in dental tissues.

    PubMed

    Ubaldini, A L M; Baesso, M L; Medina Neto, A; Sato, F; Bento, A C; Pascotto, R C

    2013-07-01

    The aim of this study was to investigate the diffusion dynamics of 25% hydrogen peroxide (H2O2) through enamel-dentin layers and to correlate it with dentin's structural alterations. Micro-Raman Spectroscopy (MRS) and Fourier Transform Infrared Photoacoustic Spectroscopy (FTIR-PAS) were used to measure the spectra of specimens before and during the bleaching procedure. H2O2 was applied to the outer surface of human enamel specimens for 60 minutes. MRS measurements were performed on the inner surface of enamel or on the subsurface dentin. In addition, H2O2 diffusion dynamics from outer enamel to dentin, passing through the dentin-enamel junction (DEJ) was obtained with Raman transverse scans. FTIR-PAS spectra were collected on the outer dentin. MRS findings revealed that H2O2 (O-O stretching µ-Raman band) crossed enamel, had a more marked concentration at DEJ, and accumulated in dentin. FTIR-PAS analysis showed that H2O2 modified dentin's organic compounds, observed by the decrease in amides I, II, and III absorption band intensities. In conclusion, H2O2 penetration was demonstrated to be not merely a physical passage through enamel interprismatic spaces into the dentinal tubules. H2O2 diffusion dynamics presented a concentration gradient determined by the chemical affinity of the H2O2 with each specific dental tissue.

  18. Materials Compatibility Testing in Concentrated Hydrogen Peroxide

    NASA Technical Reports Server (NTRS)

    Boxwell, R.; Bromley, G.; Mason, D.; Crockett, D.; Martinez, L.; McNeal, C.; Lyles, G. (Technical Monitor)

    2000-01-01

    Materials test methods from the 1960's have been used as a starting point in evaluating materials for today's space launch vehicles. These established test methods have been modified to incorporate today's analytical laboratory equipment. The Orbital test objective was to test a wide range of materials to incorporate the revolution in polymer and composite materials that has occurred since the 1960's. Testing is accomplished in 3 stages from rough screening to detailed analytical tests. Several interesting test observations have been made during this testing and are included in the paper. A summary of the set-up, test and evaluation of long-term storage sub-scale tanks is also included. This sub-scale tank test lasted for a 7-month duration prior to being stopped due to a polar boss material breakdown. Chemical evaluations of the hydrogen peroxide and residue left on the polar boss surface identify the material breakdown quite clearly. The paper concludes with recommendations for future testing and a specific effort underway within the industry to standardize the test methods used in evaluating materials.

  19. Inactivation of rabies virus by hydrogen peroxide.

    PubMed

    Abd-Elghaffar, Asmaa A; Ali, Amal E; Boseila, Abeer A; Amin, Magdy A

    2016-02-01

    Development of safe and protective vaccines against infectious pathogens remains a challenge. Inactivation of rabies virus is a critical step in the production of vaccines and other research reagents. Beta-propiolactone (βPL); the currently used inactivating agent for rabies virus is expensive and proved to be carcinogenic in animals. This study aimed to investigate the ability of hydrogen peroxide (H2O2) to irreversibly inactivate rabies virus without affecting its antigenicity and immunogenicity in pursuit of finding safe, effective and inexpensive alternative inactivating agents. H2O2 3% rapidly inactivated a Vero cell adapted fixed rabies virus strain designated as FRV/K within 2h of exposure without affecting its antigenicity or immunogenicity. No residual infectious virus was detected and the H2O2-inactivated vaccine proved to be safe and effective when compared with the same virus harvest inactivated with the classical inactivating agent βPL. Mice immunized with H2O2-inactivated rabies virus produced sufficient level of antibodies and were protected when challenged with lethal CVS virus. These findings reinforce the idea that H2O2 can replace βPL as inactivating agent for rabies virus to reduce time and cost of inactivation process. PMID:26731189

  20. Inactivation of rabies virus by hydrogen peroxide.

    PubMed

    Abd-Elghaffar, Asmaa A; Ali, Amal E; Boseila, Abeer A; Amin, Magdy A

    2016-02-01

    Development of safe and protective vaccines against infectious pathogens remains a challenge. Inactivation of rabies virus is a critical step in the production of vaccines and other research reagents. Beta-propiolactone (βPL); the currently used inactivating agent for rabies virus is expensive and proved to be carcinogenic in animals. This study aimed to investigate the ability of hydrogen peroxide (H2O2) to irreversibly inactivate rabies virus without affecting its antigenicity and immunogenicity in pursuit of finding safe, effective and inexpensive alternative inactivating agents. H2O2 3% rapidly inactivated a Vero cell adapted fixed rabies virus strain designated as FRV/K within 2h of exposure without affecting its antigenicity or immunogenicity. No residual infectious virus was detected and the H2O2-inactivated vaccine proved to be safe and effective when compared with the same virus harvest inactivated with the classical inactivating agent βPL. Mice immunized with H2O2-inactivated rabies virus produced sufficient level of antibodies and were protected when challenged with lethal CVS virus. These findings reinforce the idea that H2O2 can replace βPL as inactivating agent for rabies virus to reduce time and cost of inactivation process.

  1. Efficacy of hydrogen peroxide for treating saprolegniasis in channel catfish

    USGS Publications Warehouse

    Howe, G.E.; Gingerich, W.H.; Dawson, V.K.; Olson, J.J.

    1999-01-01

    Hatchery-reared fish and their eggs are commonly afflicted with saprolegniasis, a fungal disease that can cause significant losses in production. Fish culturists need safe and effective fungicides to minimize losses and meet production demands. The efficacy of hydrogen peroxide was evaluated for preventing or controlling mortality associated with saprolegniasis in channel catfish Ictalurus punctatus. Saprolegniasis was systematically induced in channel catfish so various therapies could be evaluated in a controlled laboratory environment. Both prophylactic and therapeutic hydrogen peroxide bath treatments of 50, 100, and 150 ??L/L for 1 h were administered every other day for seven total treatments. All untreated positive control fish died of saprolegniasis during the prophylactic and therapeutic tests. Hydrogen peroxide treatments of 150 ??L/L were harmful (relative to lower concentrations) to test fish and resulted in 73-95% mortality. Mortality was attributed to a combination of abrasion, temperature, chemical treatment, and disease stressors. Treatments of 100 ??L/L were less harmful (relatively) but also appeared to contribute to mortality (60-79%). These treatments, however, significantly reduced the incidence of mortality and infection compared with those observed for fish of the positive control or 150-??L/L treatment groups. Overall, treatments of 50 ??L/L were found to be the most safe and effective of those tested. Mortality with this concentration ranged from 16% in therapeutic tests to 41% in prophylactic tests. The statistical model employed estimated that the optimum treatment concentration for preventing or controlling mortality, reducing the incidence of infections, and enhancing the recovery of infected fish was 75 ??L H2O2/L.

  2. Bioremediation of chlorobenzene-contaminated ground water in an in situ reactor mediated by hydrogen peroxide.

    PubMed

    Vogt, Carsten; Alfreider, Albin; Lorbeer, Helmut; Hoffmann, Doreen; Wuensche, Lothar; Babel, Wolfgang

    2004-01-01

    New in situ reactive barrier technologies were tested nearby a local aquifer in Bitterfeld, Saxonia-Anhalt, Germany, which is polluted mainly by chlorobenzene (CB), in concentrations up to 450 microM. A reactor filled with original aquifer sediment was designed for the microbiological remediation of the ground water by indigenous bacterial communities. Two remediation variants were examined: (a) the degradation of CB under anoxic conditions in the presence of nitrate; (b) the degradation of CB under mixed electron acceptor conditions (oxygen+nitrate) using hydrogen peroxide as the oxygen-releasing compound. Under anoxic conditions, no definite degradation of CB was observed. Adding hydrogen peroxide (2.94 mM) and nitrate (2 mM) led to the disappearance of CB (ca. 150 microM) in the lower part of the reactor, accompanied by a strong increase of the number of cultivable aerobic CB degrading bacteria in reactor water and sediment samples, indicating that CB was degraded mainly by productive bacterial metabolism. Several aerobic CB degrading bacteria, mostly belonging to the genera Pseudomonas and Rhodococcus, were isolated from reactor water and sediments. In laboratory experiments with reactor water, oxygen was rapidly released by hydrogen peroxide, whereas biotic-induced decomposition reactions of hydrogen peroxide were almost four times faster than abiotic-induced decomposition reactions. A clear chemical degradation of CB mediated by hydrogen peroxide was not observed. CB was also completely degraded in the reactor after reducing the hydrogen peroxide concentration to 880 microM. The CB degradation completely collapsed after reducing the hydrogen peroxide concentration to 440 microM. In the following, the hydrogen peroxide concentrations were increased again (to 880 microM, 2.94 mM, and 880 microM, respectively), but the oxygen demand for CB degradation was higher than observed before, indicating a shift in the bacterial population. During the whole experiment

  3. Enhanced gellan gum production by hydrogen peroxide (H2O 2) induced oxidative stresses in Sphingomonas paucimobilis.

    PubMed

    Zhu, Guilan; Sheng, Long; Tong, Qunyi

    2014-04-01

    In this study, the effect of H2O2-induced oxidative stress on gellan gum production and cell growth were investigated. Gellan gum production was improved and cell growth was inhibited by H2O2. A multiple H2O2 stresses with different concentrations were developed to optimize gellan gum production. A maximal gellan gum yield (22.52 g/L), which was 35.58 % higher than the control, was observed with 2, 2, 3, 4 mmol/L H2O2 added at 6, 12, 18, 24 h, respectively. Moreover, UDP-glucose pyrophosphorylase activity and glucosyltransferase activity were increased with H2O2 stresses. This new strategy of multiple H2O2-induced oxidative stresses would be further applied to gellan gum production in future study.

  4. Hydrogen peroxide formation and actin filament reorganization by Cdc42 are essential for ethanol-induced in vitro angiogenesis.

    PubMed

    Qian, Yong; Luo, Jia; Leonard, Stephen S; Harris, Gabriel K; Millecchia, Lyndell; Flynn, Daniel C; Shi, Xianglin

    2003-05-01

    This report focuses on the identification of the molecular mechanisms of ethanol-induced in vitro angiogenesis. The manipulation of angiogenesis is an important therapeutic approach for the treatment of cancer, cardiovascular diseases, and chronic inflammation. Our results showed that ethanol stimulation altered the integrity of actin filaments and increased the formation of lamellipodia and filopodia in SVEC4-10 cells. Further experiments demonstrated that ethanol stimulation increased cell migration and invasion and induced in vitro angiogenesis in SVEC4-10 cells. Mechanistically, ethanol stimulation activated Cdc42 and produced H(2)O(2) a reactive oxygen species intermediate in SVEC4-10 cells. Measuring the time course of Cdc42 activation and H(2)O(2) production upon ethanol stimulation revealed that the Cdc42 activation and the increase of H(2)O(2) lasted more than 3 h, which indicates the mechanisms of the long duration effects of ethanol on the cells. Furthermore, either overexpression of a constitutive dominant negative Cdc42 or inhibition of H(2)O(2) production abrogated the effects of ethanol on SVEC4-10 cells, indicating that both the activation of Cdc42 and the production of H(2)O(2) are essential for the actions of ethanol. Interestingly, we also found that overexpression of a constitutive dominant positive Cdc42 itself was sufficient to produce H(2)O(2) and to induce in vitro angiogenesis. Taken together, our results suggest that ethanol stimulation can induce H(2)O(2) production through the activation of Cdc42, which results in reorganizing actin filaments and increasing cell motility and in vitro angiogenesis. PMID:12598535

  5. MAPK interacts with occludin and mediates EGF-induced prevention of tight junction disruption by hydrogen peroxide.

    PubMed

    Basuroy, Shyamali; Seth, Ankur; Elias, Bertha; Naren, Anjaparavanda P; Rao, Radhakrishna

    2006-01-01

    The MAPK (mitogen-activated protein kinase) pathway is a major intracellular signalling pathway involved in EGF (epithelial growth factor) receptor-mediated cell growth and differentiation. A novel function of MAPK activity in the mechanism of EGF-mediated protection of TJs (tight junctions) from H2O2 was examined in Caco-2 cell monolayers. EGF-mediated prevention of H2O2-induced increase in paracellular permeability was associated with the prevention of H2O2-induced Tyr-phosphorylation, Thr-dephosphorylation and cellular redistribution of occludin and ZO-1 (zonula occludin-1). EGF also prevented H2O2-induced disruption of the actin cytoskeleton and the dissociation of occludin and ZO-1 from the actin-rich detergent-insoluble fractions. MEK (MAPK/ERK kinase, where ERK stands for extracellular signal related kinase) inhibitors, PD98059 and U0126, completely blocked these protective effects of EGF on TJs. EGF rapidly increased the levels of phosphorylated MEK (p-MEK) in detergent-soluble fractions and phosphorylated ERK (p-ERK) in detergent-insoluble fractions. p-ERK was colocalized and co-immunoprecipitated with occludin. GST (glutathione S-transferase) pull-down assay showed that the C-terminal tail of occludin binds to p-ERK in Caco-2 cell extracts. Pair-wise binding studies using recombinant proteins demonstrated that ERK1 directly interacts with the C-terminal tail of occludin. Therefore the present study shows that ERK interacts with the C-terminal region of occludin and mediates the prevention of H2O2-induced disruption of TJs by EGF. PMID:16134968

  6. Purification of kavalactones from Alpinia zerumbet and their protective actions against hydrogen peroxide-induced cytotoxicity in PC12 cells.

    PubMed

    Rao, Yerra Koteswara; Shih, Hui-Nung; Lee, Yi-Ching; Cheng, Wen-Tai; Hung, Hui-Chin; Wang, Huang-Chi; Chen, Ching Jung; Tzeng, Yew-Min; Lee, Meng-Jen

    2014-12-01

    This study found that fruit shells of shell ginger (Alpinia zerumbet) are a rich source of the kavalactones dihydro-5,6-dehydrokavain (DDK) and 5,6-dehydrokavain (DK). The fruit shell extraction with hexane resulted in good purity and higher yields of DDK and DK than did chloroform, ethanol, 10% ethanol, methanol or water. Additionally, this study examined the neuroprotective effects of DDK and DK against H2O2-induced cytotoxicity in PC12 cells and the possible molecular mechanisms involved. 16 h after stimulation with 400 μM H2O2, the viability (MTT reduction) of PC12 cells decreased while membrane damage (LDH release) was noticeably increased. However, pretreatment for 6 h with DDK and DK (1 μM, 5 μM, 10 μM and 50 μM) rescued PC12 cells from H2O2-induced cytotoxicity, as evidenced by decreased LDH release and increased cell viability. DDK and DK inhibit the MAPK family member p38, activate AKT, and reduce caspase-3 activity. DDK also reduced the oxidative status in H2O2-treated PC12 cells. Together, our data indicate that the A. zerumbet constituents, DDK and DK, exert a protective effect against oxidative stress-induced PC12 cell death and that the regulation of p-Akt and the p38 MAPK, and of oxidative states may be involved.

  7. Nanomolar concentrations of zinc pyrithione increase cell susceptibility to oxidative stress induced by hydrogen peroxide in rat thymocytes.

    PubMed

    Oyama, Tomohiro M; Saito, Minoru; Yonezawa, Takayasu; Okano, Yoshiro; Oyama, Yasuo

    2012-06-01

    Zinc pyrithione is used as an antifouling agent. However, the environmental impacts of zinc pyrithione have recently been of concern. Zinc induces diverse actions during oxidative stress; therefore, we examined the effect of zinc pyrithione on rat thymocytes suffering from oxidative stress using appropriate fluorescent probes. The cytotoxicity of zinc pyrithione was not observed when the cells were incubated with 3 μM zinc pyrithione for 3 h. However, zinc pyrithione at nanomolar concentrations (10 nM or more) significantly increased the lethality of cells suffering from oxidative stress induced by 3 mM H(2)O(2). The application of zinc pyrithione alone at nanomolar concentrations increased intracellular Zn(2+) level and the cellular content of superoxide anions, and decreased the cellular content of nonprotein thiols. The simultaneous application of nanomolar zinc pyrithione and micromolar H(2)O(2) synergistically increased the intracellular Zn(2+) level. Therefore, zinc pyrithione at nanomolar concentrations may exert severe cytotoxic action on cells simultaneously exposed to chemicals that induce oxidative stress. If so, zinc pyrithione leaked from antifouling materials into surrounding environments would be a risk factor for aquatic ecosystems. Alternatively, zinc pyrithione under conditions of oxidative stress may become more potent antifouling ingredient. PMID:22356860

  8. Protective activity of butyrate on hydrogen peroxide-induced DNA damage in isolated human colonocytes and HT29 tumour cells.

    PubMed

    Rosignoli, P; Fabiani, R; De Bartolomeo, A; Spinozzi, F; Agea, E; Pelli, M A; Morozzi, G

    2001-10-01

    Epidemiological studies support the involvement of short-chain fatty acids (SCFA) in colon physiology and the protective role of butyrate on colon carcinogenesis. Among the possible mechanisms by which butyrate may exert its anti-carcinogenicity an antioxidant activity has been recently suggested. We investigated the effects of butyrate and mixtures of SCFA (butyrate, propionate and acetate) on DNA damage induced by H(2)O(2) in isolated human colonocytes and in two human colon tumour cell lines (HT29 and HT29 19A). Human colonocytes were isolated from endoscopically obtained samples and the DNA damage was assessed by the comet assay. H(2)O(2) induced DNA damage in normal colonocytes in a dose-dependent manner which was statistically significant at concentrations over 10 microM. At 15 microM H(2)O(2) DNA damage in HT29 and HT29 19A cells was significantly lower than that observed in normal colonocytes (P < 0.01). Pre-incubation of the cells with physiological concentrations of butyrate (6.25 and 12.5 mM) reduced H(2)O(2) (15 microM) induced damage by 33 and 51% in human colonocytes, 45 and 75% in HT29 and 30 and 80% in HT29 19A, respectively. Treatment of cells with a mixture of 25 mM acetate + 10.4 mM propionate + 6.25 mM butyrate did not induce DNA damage, while a mixture of 50 mM acetate + 20.8 mM propionate + 12.5 mM butyrate was weakly genotoxic only towards normal colonocytes. However, both mixtures were able to reduce the H(2)O(2)-induced DNA damage by about 50% in all cell types. The reported protective effect of butyrate might be important in pathogenetic mechanisms mediated by reactive oxygen species, and aids understanding of the apparent protection toward colorectal cancer exerted by dietary fibres, which enhance the butyrate bioavailability in the colonic mucosa. PMID:11577008

  9. Electrochemical Visualization of Intracellular Hydrogen Peroxide at Single Cells.

    PubMed

    He, Ruiqin; Tang, Huifen; Jiang, Dechen; Chen, Hong-yuan

    2016-02-16

    In this Letter, the electrochemical visualization of hydrogen peroxide inside one cell was achieved first using a comprehensive Au-luminol-microelectrode and electrochemiluminescence. The capillary with a tip opening of 1-2 μm was filled with the mixture of chitosan and luminol, which was coated with the thin layers of polyvinyl chloride/nitrophenyloctyl ether (PVC/NPOE) and gold as the microelectrode. Upon contact with the aqueous hydrogen peroxide, hydrogen peroxide and luminol in contact with the gold layer were oxidized under the positive potential resulting in luminescence for the imaging. Due to the small diameter of the electrode, the microelectrode tip was inserted into one cell and the bright luminescence observed at the tip confirmed the visualization of intracellular hydrogen peroxide. The further coupling of oxidase on the electrode surface could open the field in the electrochemical imaging of intracellular biomolecules at single cells, which benefited the single cell electrochemical detection. PMID:26879364

  10. Catalytic hydroxylation of benzoic acid by hydrogen peroxide

    SciTech Connect

    Pulippurasseril, C.R.; Filippova, T.Yu.; Dedov, A.G.

    1992-12-31

    An effective catalytic system based on Fe(III) and surfactants is proposed for the hydroxylation of benozic acid by hydrogen peroxide in an aqueous medium at a temperature of 30-80{degrees}C. 8 refs., 1 tab.

  11. Electrochemical Visualization of Intracellular Hydrogen Peroxide at Single Cells.

    PubMed

    He, Ruiqin; Tang, Huifen; Jiang, Dechen; Chen, Hong-yuan

    2016-02-16

    In this Letter, the electrochemical visualization of hydrogen peroxide inside one cell was achieved first using a comprehensive Au-luminol-microelectrode and electrochemiluminescence. The capillary with a tip opening of 1-2 μm was filled with the mixture of chitosan and luminol, which was coated with the thin layers of polyvinyl chloride/nitrophenyloctyl ether (PVC/NPOE) and gold as the microelectrode. Upon contact with the aqueous hydrogen peroxide, hydrogen peroxide and luminol in contact with the gold layer were oxidized under the positive potential resulting in luminescence for the imaging. Due to the small diameter of the electrode, the microelectrode tip was inserted into one cell and the bright luminescence observed at the tip confirmed the visualization of intracellular hydrogen peroxide. The further coupling of oxidase on the electrode surface could open the field in the electrochemical imaging of intracellular biomolecules at single cells, which benefited the single cell electrochemical detection.

  12. pCramoll and rCramoll as New Preventive Agents against the Oxidative Dysfunction Induced by Hydrogen Peroxide.

    PubMed

    da Silva, Luís Cláudio Nascimento; Alves, Neyla Maria Pereira; de Castro, Maria Carolina Accioly Brelaz; Higino, Taciana Mirely Maciel; da Cunha, Cássia Regina Albuquerque; Pereira, Valéria Rêgo Alves; da Paz, Nathalia Varejão Nogueira; Coelho, Luana Cassandra Breitenbach Barroso; Correia, Maria Tereza dos Santos; de Figueiredo, Regina Celia Bressan Queiroz

    2015-01-01

    Oxidative stress plays an important role in the induction of cell death and is associated with various pathologic disorders; therefore, the search for natural products that attenuate the effects produced by oxidant agents is greatly increased. Here, the protective effects of native lectin from Cratylia mollis seeds (pCramoll) and recombinant Cramoll 1 (rCramoll) against H2O2-induced oxidative stress in Vero cells were evaluated. Both lectins significantly attenuated the H2O2-induced cytotoxicity in a concentration-dependent way. The maximum protective effects were 96.85 ± 15.59% (rCramoll) and 59.48 ± 23.44% (pCramoll). The Live/Dead analysis showed a reduction in the percentage of dead cells from 65.04 ± 3.29% (H2O2) to 39.77 ± 2.93% (pCramoll) and 13.90 ± 9.01% (rCramoll). The deleterious effects of H2O2 on cell proliferation were reduced to 10.83% (pCramoll) and 24.17% (rCramoll). Lectins treatment attenuated the excessive superoxide production, the collapse of the mitochondrial membrane potential, and the lysosomal and DNA damage in H2O2-treated cells. In conclusion, our results suggest that pCramoll and rCramoll blocked H2O2-induced cytotoxicity through decreasing reactive oxygen species, restoring the mitochondrial potential, preventing the lysosomal damage and DNA fragmentation, and thus promoting cell survival and proliferation. PMID:26576224

  13. High glucose induces cell death of cultured human aortic smooth muscle cells through the formation of hydrogen peroxide

    PubMed Central

    Peiró, Concepción; Lafuente, Nuria; Matesanz, Nuria; Cercas, Elena; Llergo, José L; Vallejo, Susana; Rodríguez-Mañas, Leocadio; Sánchez-Ferrer, Carlos F

    2001-01-01

    Alterations of the vessel structure, which is mainly determined by smooth muscle cells through cell growth and/or cell death mechanisms, are characteristic of diabetes complications. We analysed the influence of high glucose (22 mM) on cultured human aortic smooth muscle cell growth and death, as hyperglycaemia is considered one of the main factors involved in diabetic vasculopathy. Growth curves were performed over 96 h in medium containing 0.5% foetal calf serum. Cell number increased by 2–4 fold over the culture period in the presence of 5.5 mM (low) glucose, while a 20% reduction in final cell number was observed with high glucose. Under serum-free conditions, cell number remained constant in low glucose cultures, but a 40% decrease was observed in high glucose cultures, suggesting that high glucose may induce increased cell death rather than reduced proliferation. Reduced final cell number induced by high glucose was also observed after stimulation with 5 or 10% foetal calf serum. The possible participation of oxidative stress was investigated by co-incubating high glucose with different reactive oxygen species scavengers. Only catalase reversed the effect of high glucose. Intracellular H2O2 content, visualized with 2′,7′-dichlorofluorescein and quantified by flow cytometry, was increased after high glucose treatment. To investigate the cell death mechanism induced by high glucose, apoptosis and necrosis were quantified. No differences were observed regarding the apoptotic index between low and high glucose cultures, but lactate dehydrogenase activity was increased in high glucose cultures. In conclusion, high glucose promotes necrotic cell death through H2O2 formation, which may participate in the development of diabetic vasculopathy. PMID:11487505

  14. pCramoll and rCramoll as New Preventive Agents against the Oxidative Dysfunction Induced by Hydrogen Peroxide

    PubMed Central

    Nascimento da Silva, Luís Cláudio; Alves, Neyla Maria Pereira; de Castro, Maria Carolina Accioly Brelaz; Higino, Taciana Mirely Maciel; da Cunha, Cássia Regina Albuquerque; Pereira, Valéria Rêgo Alves; da Paz, Nathalia Varejão Nogueira; Coelho, Luana Cassandra Breitenbach Barroso; Correia, Maria Tereza dos Santos; de Figueiredo, Regina Celia Bressan Queiroz

    2015-01-01

    Oxidative stress plays an important role in the induction of cell death and is associated with various pathologic disorders; therefore, the search for natural products that attenuate the effects produced by oxidant agents is greatly increased. Here, the protective effects of native lectin from Cratylia mollis seeds (pCramoll) and recombinant Cramoll 1 (rCramoll) against H2O2-induced oxidative stress in Vero cells were evaluated. Both lectins significantly attenuated the H2O2-induced cytotoxicity in a concentration-dependent way. The maximum protective effects were 96.85 ± 15.59% (rCramoll) and 59.48 ± 23.44% (pCramoll). The Live/Dead analysis showed a reduction in the percentage of dead cells from 65.04 ± 3.29% (H2O2) to 39.77 ± 2.93% (pCramoll) and 13.90 ± 9.01% (rCramoll). The deleterious effects of H2O2 on cell proliferation were reduced to 10.83% (pCramoll) and 24.17% (rCramoll). Lectins treatment attenuated the excessive superoxide production, the collapse of the mitochondrial membrane potential, and the lysosomal and DNA damage in H2O2-treated cells. In conclusion, our results suggest that pCramoll and rCramoll blocked H2O2-induced cytotoxicity through decreasing reactive oxygen species, restoring the mitochondrial potential, preventing the lysosomal damage and DNA fragmentation, and thus promoting cell survival and proliferation. PMID:26576224

  15. Sodium Borohydride/Hydrogen Peroxide Fuel Cells For Space Application

    NASA Technical Reports Server (NTRS)

    Valdez, T. I.; Deelo, M. E.; Narayanan, S. R.

    2006-01-01

    This viewgraph presentation examines Sodium Borohydride and Hydrogen Peroxide Fuel Cells as they are applied to space applications. The topics include: 1) Motivation; 2) The Sodium Borohydride Fuel Cell; 3) Sodium Borohydride Fuel Cell Test Stands; 4) Fuel Cell Comparisons; 5) MEA Performance; 6) Anode Polarization; and 7) Electrode Analysis. The benefits of hydrogen peroxide as an oxidant and benefits of sodium borohydride as a fuel are also addressed.

  16. Prediction and assignment of the FIR spectrum of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Helminger, P.; Messer, J. K.; De Lucia, F. C.; Bowman, W. C.

    1984-01-01

    Millimeter and submillimeter microwave studies are used to predict and assign the FIR rotational-torsional spectrum of hydrogen peroxide. Special attention is given to the strong Q-branch features that have recently been used by Traub and Chance to place an upper limit on the atmospheric abundance of hydrogen peroxide. In addition, 67 new transitions are reported in the 400-1000 GHz region.

  17. [Hydrogen peroxide in the surgery of hydatid cyst].

    PubMed

    Djilali, G; Mahrour, A; Oussedik, T; Abad, M; Bouguerra, T; Nekrouf, G; Belkaid, M; Souilamas, F

    1983-01-29

    Discouraged by the dangers and drawbacks of the usual scolicidal agents (formalin or strongly hypertonic saline), the authors have tried and adopted hydrogen peroxide in surgery of hydatid cysts. Liberal applications of this product on the operative field seem to be devoid of harmful effects. This, together with constant and rapid effectiveness, easy handling, low cost and wide availability should recommend hydrogen peroxide as the sole scolicidal agent in general surgery units.

  18. Hydrogen peroxide production protects Chlamydomonas reinhardtii against light-induced cell death by preventing singlet oxygen accumulation through enhanced carotenoid synthesis.

    PubMed

    Chang, Hsueh-Ling; Kang, Cheng-Yang; Lee, Tse-Min

    2013-07-15

    The effect of hydrogen peroxide (H₂O₂) on carotenoid synthesis in Chlamydomonas reinhardtii under light-induced stress at 3000 μmol m⁻² s⁻¹ has been investigated. This very high light (VHL) illumination triggered a transient increase in H₂O₂ production during the initial 30 min of light stress, followed by singlet oxygen (¹O₂) production, growth inhibition and necrotic cell death. The carotenoid content was slightly reduced during the first 30 min of VHL illumination and strongly diminished after 60 min, while the expression of the transcripts of enzymes involved in carotenoid biosynthesis, including phytoene synthase (PSY), phytoene desaturase (PDS), and lycopene ɛ-cyclase (LCYE), initially increased and then decreased. Lycopene β-cyclase (LCYB) transcripts did not change. Treatment with dimethylthiourea, a H₂O₂ scavenger, under VHL conditions reduced H₂O₂ production and PSY and PDS transcript levels and accelerated the reduction of carotenoids, the production of ¹O₂, viability loss and necrotic cell death. Pretreatment with 0.1 μM methyl viologen or 0.2 mM H₂O₂ under 50 μmol m⁻² s⁻¹ low light for 60 min increased VHL tolerance, carotenoid content, and PSY and PDS transcripts, while LCYB and LCYE transcripts were not affected. These results suggest that H₂O₂, produced under VHL stress, ameliorates the ¹O₂-mediated oxidative damage to C. reinhardtii through a reduction in the degree of carotenoid breakdown by activation of de novo carotenoid synthesis.

  19. Development of high-density DNA microarray membrane for profiling smoke- and hydrogen peroxide-induced genes in a human bronchial epithelial cell line.

    PubMed

    Yoneda, K; Peck, K; Chang, M M; Chmiel, K; Sher, Y P; Chen, J; Yang, P C; Chen, Y; Wu, R

    2001-11-15

    Development of the high-density DNA microarray technique permits the analysis of thousands of genes simultaneously for their differential expression patterns in various biological processes. Through clustering analysis and pattern recognition, the significance of differentially expressed genes can be recognized and correlated with biological events that may take place inside the cell and tissue. With this notion in mind, high-density DNA microarray nylon membrane with colorimetry detection was used to profile the expression of smoke- and hydrogen peroxide-inducible genes in a human bronchial epithelial cell line, HBE1. On the basis of the time course of expression, at least three phases of change in gene expression could be recognized. The first phase is an immediate event in response to oxidant injury. This phase includes induction of the bcl-2 and mdm-2 genes, which are involved in the regulation of apoptosis, and the mitogen-activated protein (MAP) kinase phosphatase 1 (MKP-1) gene, that functions as a regulator of various mitogen-activated protein kinase activities. The second phase, usually 5 h later, includes the induction of various stress proteins and ubiquitin, which are important in providing the chaperone mechanism and the turnover of damaged macromolecules. The third phase, which is 5-10 h later, includes the induction of genes that are apparently involved in reducing oxidative stress by metabolizing reactive oxygen species. In this phase, enzymes associated with tissue and cell remodeling are also elevated. These results demonstrate a complex gene expression array by bronchial epithelial cells in response to the insult of oxidants that are relevant to environmental pollutants.

  20. Salvianolic acid Y: a new protector of PC12 cells against hydrogen peroxide-induced injury from Salvia officinalis.

    PubMed

    Gong, Jun; Ju, Aichun; Zhou, Dazheng; Li, Dekun; Zhou, Wei; Geng, Wanli; Li, Bing; Li, Li; Liu, Yanjie; He, Ying; Song, Meizhen; Wang, Yunhua; Ye, Zhengliang; Lin, Ruichao

    2015-01-06

    Salvianolic acid Y (TSL 1), a new phenolic acid with the same planar structure as salvianolic acid B, was isolated from Salvia officinalis. The structural elucidation and stereochemistry determination were achieved by spectroscopic and chemical methods, including 1D, 2D-NMR (1H-1H COSY, HMQC and HMBC) and circular dichroism (CD) experiments. The biosynthesis pathway of salvianolic acid B and salvianolic acid Y (TSL 1) was proposed based on structural analysis. The protection of PC12 cells from injury induced by H2O2 was assessed in vitro using a cell viability assay. Salvianolic acid Y (TSL 1) protected cells from injury by 54.2%, which was significantly higher than salvianolic acid B (35.2%).

  1. OxyR acts as a transcriptional repressor of hydrogen peroxide-inducible antioxidant genes in Corynebacterium glutamicum R.

    PubMed

    Teramoto, Haruhiko; Inui, Masayuki; Yukawa, Hideaki

    2013-07-01

    OxyR, a LysR-type transcriptional regulator, has been established as a redox-responsive activator of antioxidant genes in bacteria. This study shows that OxyR acts as a transcriptional repressor of katA, dps, ftn and cydA in Corynebacterium glutamicum R. katA encodes H2O2-detoxifing enzyme catalase, dps and ftn are implicated in iron homeostasis and cydA encodes a subunit of cytochrome bd oxidase. Quantitative RT-PCR analyses revealed that expression of katA and dps, but not of ftn and cydA, was induced by H2O2. Disruption of the oxyR gene encoding OxyR resulted in a marked increase in katA and dps mRNAs to a level higher than that induced by H2O2, and the oxyR-deficient mutant showed a H2O2-resistant phenotype. This is in contrast to the conventional OxyR-dependent regulatory model. ftn and cydA were also upregulated by oxyR disruption but to a smaller extent. Electrophoretic mobility shift assays revealed that the OxyR protein specifically binds to all four upstream regions of the respective genes under reducing conditions. We observed that the oxidized form of OxyR similarly bound to not only the target promoter regions, but also nonspecific DNA fragments. Based on these findings, we propose that the transcriptional repression by OxyR is alleviated under oxidative stress conditions in a titration mechanism due to the decreased specificity of its DNA-binding activity. DNase I footprinting analyses revealed that the OxyR-binding site in the four target promoters is ~ 50 bp in length and has multiple T-N11-A motifs, a feature of LysR-type transcriptional regulators, but no significant overall sequence conservation. PMID:23621709

  2. Hydrogen peroxide deposition and decomposition in rain and dew waters

    NASA Astrophysics Data System (ADS)

    Ortiz, Vicky; Angélica Rubio, M.; Lissi, Eduardo A.

    Peroxides and hydrogen peroxide were determined by a fluorometric method in dew and rain collected in the atmosphere of Santiago of Chile city. The measured peroxides comprise hydrogen peroxide (the main component) and peroxides not decomposed by catalase. The collected natural peroxides readily decompose in the natural matrix, rendering difficult an estimation of the values present in real-time. In order to establish the kinetics of the process and the factors that condition their decomposition, the kinetics of the decay at several pHs and/or the presence of metal chelators were followed. The kinetics of hydrogen peroxide decomposition in the water matrix was evaluated employing the natural peroxides or hydrogen peroxide externally added. First-order kinetics was followed, with half decay times ranging from 80 to 2300 min. The addition of Fe(II) in the micromolar range increases the decomposition rate, while lowering the pH (<3) notably reduces the rate of the process. The contribution of metals to the decomposition of the peroxides in the natural waters was confirmed by the reduction in decomposition rate elicited by its treatment with Chelex-100. Dew and rain waters were collected in pre-acidified collectors, rendering values considerably higher than those measured in non-treated collectors. This indicates that acidification can be proposed as an easy procedure to stabilize the samples, reducing its decomposition during collection time and the time elapsed between collection and analysis. The weighted average concentration for total peroxides measured in pre-treated collectors was 5.4 μM in rains and 2.2 μM in dews.

  3. Generation of hydrogen peroxide in a shorted fuel cell

    SciTech Connect

    Webb, S.P.; McIntyre, J.A.

    1996-12-31

    Hydrogen peroxide is a {open_quotes}green{close_quotes} chemical with a well-assured future. As such, significant growth in demand is predicted for this material. To meet this growth, new technologies of manufacture are being contemplated to compete with the established Anthraquinone process. Some of these new methods seek the niche market of on-site generation of hydrogen peroxide. One good example of this is Dow`s caustic/peroxide generation scheme for the bleaching of paper pulp. Others rely on externally-supplied electrical power in an electrochemical reactor scheme, where peroxide may be generated additionally in neutral or acidic solution. It has long been realized that the chemical potential of the reactants themselves can be used in a controlled manner in an electrolytic cell. This is the basis of fuel cells (to generate electrical power) and has been extended to the synthesis of useful chemical species, either using solid polymer electrolytes or active oxygen transporting membranes. Use has also been made of the inherent chemical potential in H{sub 2}/O{sub 2} reactions to produce hydrogen peroxide. This reactor utilized a liquid phase cathode with dissolved air or oxygen to produce small concentrations of peroxide in a fixed volume. In fact, most schemes for the direct, electrochemical production of peroxide from hydrogen and oxygen yield low, millimolar peroxide concentrations. This paper describes the development of a scalable, segmented-flow, shorted fuel cell for the generation of greater than 1 w/o hydrogen peroxide. Three areas are of major importance in the development of a continuous, peroxide-forming reactor: the reactor design, catalyst choice and application, and the operating parameters for the reactor. The cathode catalyst is probably the single most important part. Operating parameters include such basics as temperature, pressure, gas flow rate, and liquid flow rate. Each of these topics will be discussed.

  4. A Neisseria gonorrhoeae catalase mutant is more sensitive to hydrogen peroxide and paraquat, an inducer of toxic oxygen radicals.

    PubMed

    Soler-García, Angel A; Jerse, Ann E

    2004-08-01

    Catalase is hypothesized to be critical in the protection of Neisseria gonorrhoeae from H2O2 produced during aerobic respiration and by phagocytes during infection. Here we cloned the catalase (kat) gene of gonococcal strain FA1090 and constructed a genetically defined N. gonorrhoeae kat mutant to assess the role of catalase in defense against oxidative stress. The gonococcal kat gene conferred increased H2O2 resistance to a catalase-deficient Escherichia coli strain. Mutation of the kat gene in strain FA1090 via an in-frame deletion resulted in increased sensitivity to H2O2 and paraquat, an inducer of toxic oxygen radicals. Expression of catalase in trans from a shuttle vector restored catalase activity and paraquat resistance to the kat mutant, but not resistance to H2O2. The inability to fully complement the mutant was perhaps due to a modification in the catalase, as evidenced by altered mobility of the recombinant catalase on activity gels when expressed from the shuttle vector in N. gonorrhoeae. Additionally, we showed a 262 base pair region upstream of the kat gene is required for expression in E. coli and a putative fumarate-nitrate regulator (FNR) binding site is located in this region.

  5. Hydrogen peroxide mediates abscisic acid-induced HSP70 accumulation and heat tolerance in grafted cucumber plants.

    PubMed

    Li, Hao; Liu, Shan-Shan; Yi, Chang-Yu; Wang, Feng; Zhou, Jie; Xia, Xiao-Jian; Shi, Kai; Zhou, Yan-Hong; Yu, Jing-Quan

    2014-12-01

    Root-shoot communications play important roles in plant stress responses. Here, we examined the roles of root-sourced signals in the shoot response to heat in cucumber plants. Cucumber plants grafted onto their own roots and luffa roots were exposed to aerial and root-zone heat to examine their tolerance by assessing the levels of oxidative stress, PSII photoinhibition, accumulation of abscisic acid (ABA), H2 O2 and heat shock protein (HSP) 70 using immunoblotting, chlorophyll fluorescence, immunoassay, CeCl3 staining and Western blotting, respectively. Grafting onto the luffa rootstock enhanced the shoot tolerance to the heat. This enhanced tolerance was associated with increased accumulation of ABA and apoplastic H2 O2 , RBOH transcripts and HSP70 expression and a decrease in oxidative stress in the shoots. The increases in the ABA and H2 O2 concentrations in the shoots were attributed to an increase in ABA transport from roots and an increase in ABA biosynthesis in the shoots when the root-zone and shoots were heat stressed, respectively. Inhibition of H2 O2 accumulation compromised luffa rootstock-induced HSP70 expression and heat tolerance. These results suggest that, under heat stress, ABA triggers the expression of HSP70 in an apoplastic H2 O2 -dependent manner, implicating the role of an ABA-dependent H2 O2 -driven mechanism in a systemic response involving root-shoot communication.

  6. Atmospheric hydrogen peroxide and Eoarchean iron formations.

    PubMed

    Pecoits, E; Smith, M L; Catling, D C; Philippot, P; Kappler, A; Konhauser, K O

    2015-01-01

    It is widely accepted that photosynthetic bacteria played a crucial role in Fe(II) oxidation and the precipitation of iron formations (IF) during the Late Archean-Early Paleoproterozoic (2.7-2.4 Ga). It is less clear whether microbes similarly caused the deposition of the oldest IF at ca. 3.8 Ga, which would imply photosynthesis having already evolved by that time. Abiological alternatives, such as the direct oxidation of dissolved Fe(II) by ultraviolet radiation may have occurred, but its importance has been discounted in environments where the injection of high concentrations of dissolved iron directly into the photic zone led to chemical precipitation reactions that overwhelmed photooxidation rates. However, an outstanding possibility remains with respect to photochemical reactions occurring in the atmosphere that might generate hydrogen peroxide (H2 O2 ), a recognized strong oxidant for ferrous iron. Here, we modeled the amount of H2 O2 that could be produced in an Eoarchean atmosphere using updated solar fluxes and plausible CO2 , O2 , and CH4 mixing ratios. Irrespective of the atmospheric simulations, the upper limit of H2 O2 rainout was calculated to be <10(6) molecules cm(-2) s(-1) . Using conservative Fe(III) sedimentation rates predicted for submarine hydrothermal settings in the Eoarchean, we demonstrate that the flux of H2 O2 was insufficient by several orders of magnitude to account for IF deposition (requiring ~10(11) H2 O2 molecules cm(-2) s(-1) ). This finding further constrains the plausible Fe(II) oxidation mechanisms in Eoarchean seawater, leaving, in our opinion, anoxygenic phototrophic Fe(II)-oxidizing micro-organisms the most likely mechanism responsible for Earth's oldest IF. PMID:25324177

  7. Atmospheric hydrogen peroxide and Eoarchean iron formations.

    PubMed

    Pecoits, E; Smith, M L; Catling, D C; Philippot, P; Kappler, A; Konhauser, K O

    2015-01-01

    It is widely accepted that photosynthetic bacteria played a crucial role in Fe(II) oxidation and the precipitation of iron formations (IF) during the Late Archean-Early Paleoproterozoic (2.7-2.4 Ga). It is less clear whether microbes similarly caused the deposition of the oldest IF at ca. 3.8 Ga, which would imply photosynthesis having already evolved by that time. Abiological alternatives, such as the direct oxidation of dissolved Fe(II) by ultraviolet radiation may have occurred, but its importance has been discounted in environments where the injection of high concentrations of dissolved iron directly into the photic zone led to chemical precipitation reactions that overwhelmed photooxidation rates. However, an outstanding possibility remains with respect to photochemical reactions occurring in the atmosphere that might generate hydrogen peroxide (H2 O2 ), a recognized strong oxidant for ferrous iron. Here, we modeled the amount of H2 O2 that could be produced in an Eoarchean atmosphere using updated solar fluxes and plausible CO2 , O2 , and CH4 mixing ratios. Irrespective of the atmospheric simulations, the upper limit of H2 O2 rainout was calculated to be <10(6) molecules cm(-2) s(-1) . Using conservative Fe(III) sedimentation rates predicted for submarine hydrothermal settings in the Eoarchean, we demonstrate that the flux of H2 O2 was insufficient by several orders of magnitude to account for IF deposition (requiring ~10(11) H2 O2 molecules cm(-2) s(-1) ). This finding further constrains the plausible Fe(II) oxidation mechanisms in Eoarchean seawater, leaving, in our opinion, anoxygenic phototrophic Fe(II)-oxidizing micro-organisms the most likely mechanism responsible for Earth's oldest IF.

  8. Hydrogen Peroxide in Groundwater at Rifle, Colorado

    NASA Astrophysics Data System (ADS)

    Yuan, X.; Nico, P. S.; Williams, K. H.; Hobson, C.; Davis, J. A.

    2015-12-01

    Hydrogen peroxide (H2O2), as a reactive transient presenting ubiquitously in natural surface waters, can react with a large suite of biologically important and redox-sensitive trace elements. The dominant source of H2O2 in natural waters has long been thought to be photo-oxidation of chromophoric dissolved organic matter by molecular oxygen to produce superoxide radical, which then proceeds via dismutation to generate H2O2. However, recent studies have indicated that dark production of H2O2 in deep seawater, principally by biological production, is potentially on par with photochemical generation. Here, we present evidence for abiotic dark generation of H2O2 in groundwater in an alluvial aquifer adjacent to the Colorado River near Rifle, CO. Background H2O2 concentrations were determined in situ using a sensitive chemiluminescence-based method. Our results suggest H2O2 concentrations ranged from lower than the detection limit (1 nM) to 54 nM in different monitoring wells at the site, and the concentrations exhibited close correlations with profiles of dissolved oxygen and iron concentrations in the wells, indicating a possible metal redox cycling mechanism. In addition, dissolved natural organic matter, which could potentially coordinate the interconversion of ferric and ferrous species, might also play an important role in H2O2 formation. While biologically mediated activities have been recognized as the major sink of H2O2, the detected H2O2 pattern in groundwater suggests the existence of a balance between H2O2 source and decay, which potentially involves a cascade of biogeochemically significant processes, including the interconversion of ferrous/ferric species, the generation of more reactive oxygen species, such as hydroxyl radical, the depletion of dissolved oxygen and further transformation of natural organic matter and other chemical pollutants.

  9. Recent Development in Hydrogen Peroxide Pumped Propulsion

    SciTech Connect

    Ledebuhr, A G; Antelman, D R; Dobie, D W; Gorman, T S; Jones, M S; Kordas, J F; McMahon, D H; Ng, L C; Nielsen, D P; Ormsby, A E; Pittenger, L C; Robinson, J A; Skulina, K M; Taylor, W G; Urone, D A; Wilson, B A

    2004-03-22

    This paper describes the development of a lightweight high performance pump-fed divert and attitude control system (DACS). Increased kinetic Kill Vehicles (KV) capabilities (higher .v and acceleration capability) will especially be needed for boost phase engagements where a lower mass KV DACS enables smaller overall interceptors. To increase KV performance while reducing the total DACS dry mass (<10 kg), requires a design approach that more closely emulates those found in large launch vehicles, where pump-fed propulsion enables high propellant-mass-fraction systems. Miniaturized reciprocating pumps, on a scale compatible with KV applications, offer the potential of a lightweight DACS with both high {Delta}v and acceleration capability, while still enabling the rapid pulsing of the divert thrusters needed in the end-game fly-in. Pumped propulsion uses lightweight low-pressure propellant tanks, as the main vehicle structure and eliminates the need for high-pressure gas bottles, reducing mass and increasing the relative propellant load. Prior work used hydrazine and demonstrated a propellant mass fraction >0.8 and a vehicle propulsion dry mass of {approx}3 kg. Our current approach uses the non-toxic propellants 90% hydrogen peroxide and kerosene. This approach enables faster development at lower costs due to the ease of handling. In operational systems these non-toxic propellants can simplify the logistics for manned environments including shipboard applications. This DACS design configuration is expected to achieve sufficient mass flows to support divert thrusters in the 1200 N to 1330 N (270 lbf to 300 lbf) range. The DACS design incorporates two pairs of reciprocating differential piston pumps (oxidizer and fuel), a warm-gas drive system, compatible bi-propellant thrusters, lightweight valves, and lightweight low-pressure propellant tanks. This paper summarizes the current development status and plans.

  10. Localised hydrogen peroxide sensing for reproductive health

    NASA Astrophysics Data System (ADS)

    Purdey, Malcolm S.; Schartner, Erik P.; Sutton-McDowall, Melanie L.; Ritter, Lesley J.; Thompson, Jeremy G.; Monro, Tanya M.; Abell, Andrew D.

    2015-05-01

    The production of reactive oxygen species (ROS) is known to affect the developmental competence of embryos. Hydrogen peroxide (H2O2) an important reactive oxygen species, is also known to causes DNA damage and defective sperm function. Current techniques require incubating a developing embryo with an organic fluorophore which is potentially hazardous for the embryo. What we need is a localised ROS sensor which does not require fluorophores in solution and hence will allow continuous monitoring of H2O2 production without adversely affect the development of the embryo. Here we report studies on such a fibre-based sensor for the detection of H2O2 that uses a surface-bound aryl boronate fluorophore carboxyperoxyfluor-1(CPF1). Optical fibres present a unique platform due to desirable characteristics as dip sensors in biological solutions. Attempts to functionalise the fibre tips using polyelectrolyte layers and (3-aminopropyl)triethoxysilane (APTES) coatings resulted in a limited signal and poor fluorescent response to H2O2 due to a low tip surface density of the fluorophore. To increase the surface density, CPF1 was integrated into a polymer matrix formed on the fibre tip by a UV-catalysed polymerisation process of acrylamide onto a methacrylate silane layer. The polyacrylamide containing CPF1 gave a much higher surface density than previous surface attachment methods and the sensor was found to effectively detect H2O2. Using this method, biologically relevant concentrations of H2O2 were detected, enabling remote sensing studies into ROS releases from embryos throughout early development.

  11. Low Concentrations of Hydrogen Peroxide or Nitrite Induced of Paracoccidioides brasiliensis Cell Proliferation in a Ras-Dependent Manner

    PubMed Central

    Haniu, Ana Eliza Coronel Janu; Maricato, Juliana Terzi; Mathias, Pedro Paulo Moraes; Castilho, Daniele Gonçalves; Miguel, Rodrigo Bernardi; Monteiro, Hugo Pequeno; Puccia, Rosana; Batista, Wagner Luiz

    2013-01-01

    Paracoccidioides brasiliensis, a causative agent of paracoccidioidomycosis (PCM), should be able to adapt to dramatic environmental changes inside the infected host after inhalation of air-borne conidia and transition to pathogenic yeasts. Proteins with antioxidant functions may protect fungal cells against reactive oxygen (ROS) and nitrogen (RNS) species generated by phagocytic cells, thus acting as potential virulence factors. Ras GTPases are involved in stress responses, cell morphology, and differentiation in a range of organisms. Ras, in its activated form, interacts with effector proteins and can initiate a kinase cascade. In lower eukaryotes, Byr2 kinase represents a Ras target. The present study investigated the role of Ras in P. brasiliensis after in vitro stimulus with ROS or RNS. We have demonstrated that low concentrations of H2O2 (0.1 mM) or NO2 (0.1–0.25 µM) stimulated P. brasiliensis yeast cell proliferation and that was not observed when yeast cells were pre-incubated with farnesyltransferase inhibitor. We constructed an expression plasmid containing the Byr2 Ras-binding domain (RBD) fused with GST (RBD-Byr2-GST) to detect the Ras active form. After stimulation with low concentrations of H2O2 or NO2, the Ras active form was observed in fungal extracts. Besides, NO2 induced a rapid increase in S-nitrosylated Ras levels. This alternative posttranslational modification of Ras, probably in residue Cys123, would lead to an exchange of GDP for GTP and consequent GTPase activation in P. brasiliensis. In conclusion, low concentrations of H2O2 or NO2 stimulated P. brasiliensis proliferation through Ras activation. PMID:23922749

  12. Different Modes of Hydrogen Peroxide Action During Seed Germination.

    PubMed

    Wojtyla, Łukasz; Lechowska, Katarzyna; Kubala, Szymon; Garnczarska, Małgorzata

    2016-01-01

    Hydrogen peroxide was initially recognized as a toxic molecule that causes damage at different levels of cell organization and thus losses in cell viability. From the 1990s, the role of hydrogen peroxide as a signaling molecule in plants has also been discussed. The beneficial role of H2O2 as a central hub integrating signaling network in response to biotic and abiotic stress and during developmental processes is now well established. Seed germination is the most pivotal phase of the plant life cycle, affecting plant growth and productivity. The function of hydrogen peroxide in seed germination and seed aging has been illustrated in numerous studies; however, the exact role of this molecule remains unknown. This review evaluates evidence that shows that H2O2 functions as a signaling molecule in seed physiology in accordance with the known biology and biochemistry of H2O2. The importance of crosstalk between hydrogen peroxide and a number of signaling molecules, including plant phytohormones such as abscisic acid, gibberellins, and ethylene, and reactive molecules such as nitric oxide and hydrogen sulfide acting on cell communication and signaling during seed germination, is highlighted. The current study also focuses on the detrimental effects of H2O2 on seed biology, i.e., seed aging that leads to a loss of germination efficiency. The dual nature of hydrogen peroxide as a toxic molecule on one hand and as a signal molecule on the other is made possible through the precise spatial and temporal control of its production and degradation. Levels of hydrogen peroxide in germinating seeds and young seedlings can be modulated via pre-sowing seed priming/conditioning. This rather simple method is shown to be a valuable tool for improving seed quality and for enhancing seed stress tolerance during post-priming germination. In this review, we outline how seed priming/conditioning affects the integrative role of hydrogen peroxide in seed germination and aging.

  13. Different Modes of Hydrogen Peroxide Action During Seed Germination.

    PubMed

    Wojtyla, Łukasz; Lechowska, Katarzyna; Kubala, Szymon; Garnczarska, Małgorzata

    2016-01-01

    Hydrogen peroxide was initially recognized as a toxic molecule that causes damage at different levels of cell organization and thus losses in cell viability. From the 1990s, the role of hydrogen peroxide as a signaling molecule in plants has also been discussed. The beneficial role of H2O2 as a central hub integrating signaling network in response to biotic and abiotic stress and during developmental processes is now well established. Seed germination is the most pivotal phase of the plant life cycle, affecting plant growth and productivity. The function of hydrogen peroxide in seed germination and seed aging has been illustrated in numerous studies; however, the exact role of this molecule remains unknown. This review evaluates evidence that shows that H2O2 functions as a signaling molecule in seed physiology in accordance with the known biology and biochemistry of H2O2. The importance of crosstalk between hydrogen peroxide and a number of signaling molecules, including plant phytohormones such as abscisic acid, gibberellins, and ethylene, and reactive molecules such as nitric oxide and hydrogen sulfide acting on cell communication and signaling during seed germination, is highlighted. The current study also focuses on the detrimental effects of H2O2 on seed biology, i.e., seed aging that leads to a loss of germination efficiency. The dual nature of hydrogen peroxide as a toxic molecule on one hand and as a signal molecule on the other is made possible through the precise spatial and temporal control of its production and degradation. Levels of hydrogen peroxide in germinating seeds and young seedlings can be modulated via pre-sowing seed priming/conditioning. This rather simple method is shown to be a valuable tool for improving seed quality and for enhancing seed stress tolerance during post-priming germination. In this review, we outline how seed priming/conditioning affects the integrative role of hydrogen peroxide in seed germination and aging. PMID:26870076

  14. Different Modes of Hydrogen Peroxide Action During Seed Germination

    PubMed Central

    Wojtyla, Łukasz; Lechowska, Katarzyna; Kubala, Szymon; Garnczarska, Małgorzata

    2016-01-01

    Hydrogen peroxide was initially recognized as a toxic molecule that causes damage at different levels of cell organization and thus losses in cell viability. From the 1990s, the role of hydrogen peroxide as a signaling molecule in plants has also been discussed. The beneficial role of H2O2 as a central hub integrating signaling network in response to biotic and abiotic stress and during developmental processes is now well established. Seed germination is the most pivotal phase of the plant life cycle, affecting plant growth and productivity. The function of hydrogen peroxide in seed germination and seed aging has been illustrated in numerous studies; however, the exact role of this molecule remains unknown. This review evaluates evidence that shows that H2O2 functions as a signaling molecule in seed physiology in accordance with the known biology and biochemistry of H2O2. The importance of crosstalk between hydrogen peroxide and a number of signaling molecules, including plant phytohormones such as abscisic acid, gibberellins, and ethylene, and reactive molecules such as nitric oxide and hydrogen sulfide acting on cell communication and signaling during seed germination, is highlighted. The current study also focuses on the detrimental effects of H2O2 on seed biology, i.e., seed aging that leads to a loss of germination efficiency. The dual nature of hydrogen peroxide as a toxic molecule on one hand and as a signal molecule on the other is made possible through the precise spatial and temporal control of its production and degradation. Levels of hydrogen peroxide in germinating seeds and young seedlings can be modulated via pre-sowing seed priming/conditioning. This rather simple method is shown to be a valuable tool for improving seed quality and for enhancing seed stress tolerance during post-priming germination. In this review, we outline how seed priming/conditioning affects the integrative role of hydrogen peroxide in seed germination and aging. PMID:26870076

  15. Microbiologic evaluation of a hydrogen peroxide sterilization system.

    PubMed

    Wilkins, D L; Chung, P Y; Tsuchiya, P Y; Wessels, I F; Zuccarelli, A J

    1994-01-01

    The reliability of chemical sterilizers (acetone and/or 30-percent hydrogen peroxide at 25 degrees C and at 60 degrees C) was tested against Bacillus subtilis inoculated onto glass slides, commercial biological indicator discs (Bacillus stearothermophilus and B. subtilis), and B. subtilis spore survival. Acetone alone was not sporicidal. Hydrogen-peroxide-sterilized glass slides were sterile after 5 minutes. The indicator discs required 25 minutes at 25 degrees C, and less than 3 minutes at 60 degrees C (P < .0001). The D value of B. subtilis in 27-percent hydrogen peroxide at 25 degrees C is 2 minutes, with z values of 22 degrees C and 26 degrees C at 25 degrees C and 40 degrees C, respectively. For delicate instruments, a 30-percent peroxide solution followed by an acetone rinse provides an effective alternative to classic heat sterilization.

  16. Depletion of OLFM4 gene inhibits cell growth and increases sensitization to hydrogen peroxide and tumor necrosis factor-alpha induced-apoptosis in gastric cancer cells

    PubMed Central

    2012-01-01

    Background Human olfactomedin 4 (OLFM4) gene is a secreted glycoprotein more commonly known as the anti-apoptotic molecule GW112. OLFM4 is found to be frequently up-regulated in many types of human tumors including gastric cancer and it was believed to play significant role in the progression of gastric cancer. Although the function of OLFM4 has been indicated in many studies, recent evidence strongly suggests a cell or tissue type-dependent role of OLFM4 in cell growth and apoptosis. The aim of this study is to examine the role of gastric cancer-specific expression of OLFM4 in cell growth and apoptosis resistance. Methods OLFM4 expression was eliminated by RNA interference in SGC-7901 and MKN45 cells. Cell proliferation, anchorage-independent growth, cell cycle and apoptosis were characterized in vitro. Tumorigenicity was analyzed in vivo. The apoptosis and caspase-3 activation in response to hydrogen peroxide (H2O2) or tumor necrosis factor-alpha (TNF α) were assessed in the presence or absence of caspase inhibitor Z-VAD-fmk. Results The elimination of OLFM4 protein by RNA interference in SGC-7901 and MKN45 cells significantly inhibits tumorigenicity both in vitro and in vivo by induction of cell G1 arrest (all P < 0.01). OLFM4 knockdown did not trigger obvious cell apoptosis but increased H2O2 or TNF α-induced apoptosis and caspase-3 activity (all P < 0.01). Treatment of Z-VAD-fmk attenuated caspase-3 activity and significantly reversed the H2O2 or TNF α-induced apoptosis in OLFM4 knockdown cells (all P < 0.01). Conclusion Our study suggests that depletion of OLFM4 significantly inhibits tumorigenicity of the gastric cancer SGC-7901 and MKN45 cells. Blocking OLFM4 expression can sensitize gastric cancer cells to H2O2 or TNF α treatment by increasing caspase-3 dependent apoptosis. A combination strategy based on OLFM4 inhibition and anticancer drugs treatment may provide therapeutic potential in gastric cancer intervention. PMID:22471589

  17. [Accelerated senescence of fresh-cut Chinese water chestnut tissues in relation to hydrogen peroxide accumulation].

    PubMed

    Peng, Li-Tao; Jiang, Yue-Ming; Yang, Shu-Zhen; Pan, Si-Yi

    2005-10-01

    Accelerated senescence of fresh-cut Chinese water chestnut (CWC) tissues in relation to active oxygen species (AOS) metabolism was investigated. Fresh-cut CWC (2 mm thick) and intact CWC were stored at 4 degrees C in trays wrapped with plastic films. Changes in superoxide anion production rate, activities of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) were monitored, while contents of hydrogen peroxide, ascorbic acid, MDA as well as electrolyte leakage were measured. Fresh-cutting of CWC induced activities of SOD, CAT and APX to a certain extent (Fig. 2B and Fig. 3), but simultaneously stimulated superoxide anion production markedly (Fig. 2A), enhanced hydrogen peroxide accumulation and accelerated loss in ascorbic acid (Figs. 4 and 5), which resulted in increased lipid peroxidation indicated by malondialdehyde (MDA) content and electrolyte leakage (Fig. 1). Statistics analysis indicated that there was a significantly positive correlation among hydrogen peroxide accumulation, MDA content and electrolyte leakage (Table 1). Histochemical detection with 3, 3'-diaminobenzidine further demonstrated that hydrogen peroxide accumulation increased in fresh-cut CWC during storage (Fig. 5). AOS production rate and activities of SOD, CAT and APX changed little while no obvious hydrogen peroxide accumulation was observed, in intact CWC during storage.

  18. Fisetin inhibits TNF-α-induced inflammatory action and hydrogen peroxide-induced oxidative damage in human keratinocyte HaCaT cells through PI3K/AKT/Nrf-2-mediated heme oxygenase-1 expression.

    PubMed

    Seo, Seung-Hee; Jeong, Gil-Saeng

    2015-12-01

    Oxidative skin damage and skin inflammation play key roles in the pathogenesis of skin-related diseases. Fisetin is a naturally occurring flavonoid abundantly found in several vegetables and fruits. Fisetin has been shown to exert various positive biological effects, such as anti-cancer, anti-proliferative, neuroprotective and anti-oxidative effects. In this study, we investigate the skin protective effects and anti-inflammatory properties of fisetin in hydrogen peroxide- and TNF-α-challenged human keratinocyte HaCaT cells. When HaCaT cells were treated with non-cytotoxic concentrations of fisetin (1-20μM), heme oxygenase (HO)-1 mRNA and protein expression increased in a dose-dependent manner. Furthermore, fisetin dose-dependently increased cell viability and reduced ROS production in hydrogen peroxide-treated HaCaT cells. Fisetin also inhibited the production of NO, PGE2 IL-1β, IL-6, expression of iNOS and COX-2, and activation of NF-κB in HaCaT cells treated with TNF-α. Fisetin induced Nrf2 translocation to the nuclei. HO-1 siRNA transient transfection reversed the effects of fisetin on cytoprotection, ROS reduction, NO, PGE2, IL-1β, IL-6, and TNF-α production, and NF-κB DNA-binding activity. Moreover, fisetin increased Akt phosphorylation and a PI3K pathway inhibitor (LY294002) abolished fisetin-induced cytoprotection and NO inhibition. Taken together, these results provide evidence for a beneficial role of fisetin in skin therapy. PMID:26590114

  19. Fisetin inhibits TNF-α-induced inflammatory action and hydrogen peroxide-induced oxidative damage in human keratinocyte HaCaT cells through PI3K/AKT/Nrf-2-mediated heme oxygenase-1 expression.

    PubMed

    Seo, Seung-Hee; Jeong, Gil-Saeng

    2015-12-01

    Oxidative skin damage and skin inflammation play key roles in the pathogenesis of skin-related diseases. Fisetin is a naturally occurring flavonoid abundantly found in several vegetables and fruits. Fisetin has been shown to exert various positive biological effects, such as anti-cancer, anti-proliferative, neuroprotective and anti-oxidative effects. In this study, we investigate the skin protective effects and anti-inflammatory properties of fisetin in hydrogen peroxide- and TNF-α-challenged human keratinocyte HaCaT cells. When HaCaT cells were treated with non-cytotoxic concentrations of fisetin (1-20μM), heme oxygenase (HO)-1 mRNA and protein expression increased in a dose-dependent manner. Furthermore, fisetin dose-dependently increased cell viability and reduced ROS production in hydrogen peroxide-treated HaCaT cells. Fisetin also inhibited the production of NO, PGE2 IL-1β, IL-6, expression of iNOS and COX-2, and activation of NF-κB in HaCaT cells treated with TNF-α. Fisetin induced Nrf2 translocation to the nuclei. HO-1 siRNA transient transfection reversed the effects of fisetin on cytoprotection, ROS reduction, NO, PGE2, IL-1β, IL-6, and TNF-α production, and NF-κB DNA-binding activity. Moreover, fisetin increased Akt phosphorylation and a PI3K pathway inhibitor (LY294002) abolished fisetin-induced cytoprotection and NO inhibition. Taken together, these results provide evidence for a beneficial role of fisetin in skin therapy.

  20. Hydrogen Peroxide, Signaling in Disguise during Metal Phytotoxicity

    PubMed Central

    Cuypers, Ann; Hendrix, Sophie; Amaral dos Reis, Rafaela; De Smet, Stefanie; Deckers, Jana; Gielen, Heidi; Jozefczak, Marijke; Loix, Christophe; Vercampt, Hanne; Vangronsveld, Jaco; Keunen, Els

    2016-01-01

    Plants exposed to excess metals are challenged by an increased generation of reactive oxygen species (ROS) such as superoxide (O2•-), hydrogen peroxide (H2O2) and the hydroxyl radical (•OH). The mechanisms underlying this oxidative challenge are often dependent on metal-specific properties and might play a role in stress perception, signaling and acclimation. Although ROS were initially considered as toxic compounds causing damage to various cellular structures, their role as signaling molecules became a topic of intense research over the last decade. Hydrogen peroxide in particular is important in signaling because of its relatively low toxicity, long lifespan and its ability to cross cellular membranes. The delicate balance between its production and scavenging by a plethora of enzymatic and metabolic antioxidants is crucial in the onset of diverse signaling cascades that finally lead to plant acclimation to metal stress. In this review, our current knowledge on the dual role of ROS in metal-exposed plants is presented. Evidence for a relationship between H2O2 and plant metal tolerance is provided. Furthermore, emphasis is put on recent advances in understanding cellular damage and downstream signaling responses as a result of metal-induced H2O2 production. Finally, special attention is paid to the interaction between H2O2 and other signaling components such as transcription factors, mitogen-activated protein kinases, phytohormones and regulating systems (e.g. microRNAs). These responses potentially underlie metal-induced senescence in plants. Elucidating the signaling network activated during metal stress is a pivotal step to make progress in applied technologies like phytoremediation of polluted soils. PMID:27199999

  1. The hydrogen peroxide impact on larval settlement and metamorphosis of abalone Haliotis diversicolor supertexta

    NASA Astrophysics Data System (ADS)

    Zhang, Xiangjing; Yang, Zhihui; Cai, Zhonghua

    2008-08-01

    Abalone Haliotis diversicolor supertexta is an important economic mollusk. The settlement and metamorphosis are two critical stages during its development period, which has direct influence on abalone survival and production. The influence of reactive oxygen species (hydrogen peroxide) on abalone embryo and juvenile development were examined in this study. Larvae of Haliotis diversicolor supertexta were induced to settlement and metamorphose by exposure to seawater supplemented with hydrogen peroxide. They had the best performance at 800 μmol/L. The concentration of 1 000 μmol/L or higher was toxic to the larvae, as the larvae could settle down only at benthic diatom plates without complete metamorphosis. In addition, H2O2 adding time was critical to the larval performance. 24h after two-day post-fertilization was proved to be the optimal adding time. In this paper, two action mechanisms of hydrogen peroxide are discussed: (1) hydrogen peroxide has direct toxicity to ciliated cells, thus cause apoptosis; (2) hydrogen peroxide, as a product from catecholamines’ autoxidation process in vivo, can reverse this process to produce neuro-transmitters to induce abalone metamorphosis.

  2. Activation of Store-Operated ICRAC by Hydrogen Peroxide

    PubMed Central

    Grupe, Morten; Myers, George; Penner, Reinhold; Fleig, Andrea

    2010-01-01

    SUMMARY Reactive oxygen species such as hydrogen peroxide (H2O2) play a role in both innate immunity as well as cellular injury. H2O2 induces changes in intracellular calcium ([Ca2+]i) in many cell types and this seems to be at least partially mediated by transient receptor potential melastatin 2 (TRPM2) in cells that express this channel. Here we show that low concentrations of H2O2 induce the activation of the Ca2+-release activated Ca2+ current ICRAC. This effect is not mediated by direct CRAC channel activation, since H2O2 does not activate heterologously expressed CRAC channels independently of stromal interaction molecule (STIM). Instead, ICRAC activation is partially mediated by store depletion through activation of inositol 1,4,5 trisphosphate receptors (IP3R), since pharmacological inhibition of IP3 receptors by heparin or molecular knock-out of all IP3 receptors in DT40 B cells strongly reduce H2O2-induced ICRAC. The remainder of H2O2-induced ICRAC activation is likely mediated by IP3R-independent store-depletion. Our data suggest that H2O2 can activate Ca2+ entry through TRPM2 as well as store-operated CRAC channels, thereby adding a new facet to ROS-induced Ca2+ signaling. PMID:20646759

  3. 14 CFR 420.66 - Separation distance requirements for storage of hydrogen peroxide, hydrazine, and liquid hydrogen...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... storage of hydrogen peroxide, hydrazine, and liquid hydrogen and any incompatible energetic liquids stored... Responsibilities of a Licensee § 420.66 Separation distance requirements for storage of hydrogen peroxide... section for each explosive hazard facility storing: (1) Hydrogen peroxide in concentrations of...

  4. 14 CFR 420.66 - Separation distance requirements for storage of hydrogen peroxide, hydrazine, and liquid hydrogen...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... storage of hydrogen peroxide, hydrazine, and liquid hydrogen and any incompatible energetic liquids stored... Responsibilities of a Licensee § 420.66 Separation distance requirements for storage of hydrogen peroxide... section for each explosive hazard facility storing: (1) Hydrogen peroxide in concentrations of...

  5. Selective electrochemical generation of hydrogen peroxide from water oxidation

    DOE PAGESBeta

    Viswanathan, Venkatasubramanian; Hansen, Heine A.; Norskov, Jens K.

    2015-10-08

    Water is a life-giving source, fundamental to human existence, yet over a billion people lack access to clean drinking water. The present techniques for water treatment such as piped, treated water rely on time and resource intensive centralized solutions. In this work, we propose a decentralized device concept that can utilize sunlight to split water into hydrogen and hydrogen peroxide. The hydrogen peroxide can oxidize organics while the hydrogen bubbles out. In enabling this device, we require an electrocatalyst that can oxidize water while suppressing the thermodynamically favored oxygen evolution and form hydrogen peroxide. Using density functional theory calculations, wemore » show that the free energy of adsorbed OH* can be used to determine selectivity trends between the 2e– water oxidation to H2O2 and the 4e– oxidation to O2. We show that materials which bind oxygen intermediates sufficiently weakly, such as SnO2, can activate hydrogen peroxide evolution. Furthermore, we present a rational design principle for the selectivity in electrochemical water oxidation and identify new material candidates that could perform H2O2 evolution selectively.« less

  6. Selective electrochemical generation of hydrogen peroxide from water oxidation

    SciTech Connect

    Viswanathan, Venkatasubramanian; Hansen, Heine A.; Norskov, Jens K.

    2015-10-08

    Water is a life-giving source, fundamental to human existence, yet over a billion people lack access to clean drinking water. The present techniques for water treatment such as piped, treated water rely on time and resource intensive centralized solutions. In this work, we propose a decentralized device concept that can utilize sunlight to split water into hydrogen and hydrogen peroxide. The hydrogen peroxide can oxidize organics while the hydrogen bubbles out. In enabling this device, we require an electrocatalyst that can oxidize water while suppressing the thermodynamically favored oxygen evolution and form hydrogen peroxide. Using density functional theory calculations, we show that the free energy of adsorbed OH* can be used to determine selectivity trends between the 2e– water oxidation to H2O2 and the 4e– oxidation to O2. We show that materials which bind oxygen intermediates sufficiently weakly, such as SnO2, can activate hydrogen peroxide evolution. Furthermore, we present a rational design principle for the selectivity in electrochemical water oxidation and identify new material candidates that could perform H2O2 evolution selectively.

  7. Selective Electrochemical Generation of Hydrogen Peroxide from Water Oxidation.

    PubMed

    Viswanathan, Venkatasubramanian; Hansen, Heine A; Nørskov, Jens K

    2015-11-01

    Water is a life-giving source, fundamental to human existence, yet over a billion people lack access to clean drinking water. The present techniques for water treatment such as piped, treated water rely on time and resource intensive centralized solutions. In this work, we propose a decentralized device concept that can utilize sunlight to split water into hydrogen and hydrogen peroxide. The hydrogen peroxide can oxidize organics while the hydrogen bubbles out. In enabling this device, we require an electrocatalyst that can oxidize water while suppressing the thermodynamically favored oxygen evolution and form hydrogen peroxide. Using density functional theory calculations, we show that the free energy of adsorbed OH* can be used to determine selectivity trends between the 2e(-) water oxidation to H2O2 and the 4e(-) oxidation to O2. We show that materials which bind oxygen intermediates sufficiently weakly, such as SnO2, can activate hydrogen peroxide evolution. We present a rational design principle for the selectivity in electrochemical water oxidation and identify new material candidates that could perform H2O2 evolution selectively.

  8. Hydrogen peroxide sensor using laser grade dye Rhodamine B

    NASA Astrophysics Data System (ADS)

    Pattanaik, Amitansu; Sahare, P. D.; Nanda, Maitreyee

    2007-11-01

    Many chemical sensors based on fluorescence spectroscopy have been reported in applications, ranging from biomedical and environmental monitoring to industrial process control. In these diverse applications, the analyte can be probed directly, by measuring its intrinsic absorption, or by incorporating some transduction mechanism such as reagent chemistry to enhance sensitivity and selectivity. Hydrogen Peroxide is a colorless liquid. It is a common oxidizing and bleaching agent. It plays an important role in High Power Laser such as Chemical Oxygen Iodine Laser (COIL). As it is on the Hazardous substance list and on the special health hazard substance list, detection of Hydrogen Peroxide is of great importance. In the present study the detection of hydrogen Peroxide is by fluorescence quenching of laser grade dye Rhodamine B. Estimation of rate constant of the bimolecular quenching reaction is made.

  9. Cathodic electrocatalyst layer for electrochemical generation of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Rhodes, Christopher P. (Inventor); Tennakoon, Charles L. K. (Inventor); Singh, Waheguru Pal (Inventor); Anderson, Kelvin C. (Inventor)

    2011-01-01

    A cathodic gas diffusion electrode for the electrochemical production of aqueous hydrogen peroxide solutions. The cathodic gas diffusion electrode comprises an electrically conductive gas diffusion substrate and a cathodic electrocatalyst layer supported on the gas diffusion substrate. A novel cathodic electrocatalyst layer comprises a cathodic electrocatalyst, a substantially water-insoluble quaternary ammonium compound, a fluorocarbon polymer hydrophobic agent and binder, and a perfluoronated sulphonic acid polymer. An electrochemical cell using the novel cathodic electrocatalyst layer has been shown to produce an aqueous solution having between 8 and 14 weight percent hydrogen peroxide. Furthermore, such electrochemical cells have shown stable production of hydrogen peroxide solutions over 1000 hours of operation including numerous system shutdowns.

  10. Oxidative desulfurization of Tufanbeyli coal by hydrogen peroxide solution

    SciTech Connect

    Guru, M.; Sarioz, B.V.; Cakanyildirim, C.

    2008-07-01

    It is becoming popular to use fossil fuels efficiently since the necessary energy is mostly supplied from fossil fuels. Altough there are high lignite reserves, high sulfur content limits the efficient use of them. In this article, we aimed to convert combustible sulfur in coal to non-combustible sulfate form in the ash by oxidizing it with a hydrogen peroxide solution. The parameters affecting the sulfur conversion were determined to be: hydrogen peroxide concentration, reaction time, mean particle size at constant room temperature and shaking rate. The maximum desulfurization efficiency reached was 74% of the original combustible sulfur with 15% (w/w) hydrogen peroxide solution, 12 hours of reaction time, and 0.25 mm mean particle size.

  11. Biologically active constituents from Salix viminalis bio-oil and their protective activity against hydrogen peroxide-induced oxidative stress in Chinese hamster ovary cells.

    PubMed

    Ilnicka, Anna; Roszek, Katarzyna; Olejniczak, Andrzej; Komoszynski, Michal; Lukaszewicz, Jerzy P

    2014-11-01

    The protective antioxidative effect of the phenolic extract (PE) isolated from Salix viminalis pyrolysis derived bio-oil was shown in vitro on the Chinese hamster ovary (CHO) cells exposed to hydrogen peroxide (H2O2). Cells pretreated with 0.05 μg/ml PE after exposure to different concentrations of H2O2 (300-900 μM) showed up to 25 % higher viability than the unpretreated ones. The antioxidative effect of PE was also observed in a time-dependent manner. The results were confirmed by visual examination of the specimens using microscopy. Finally, superoxide dismutase (SOD) activity modulation was shown by SOD assay, designed to determine the activity of enzymes removing free radicals.

  12. Hydrogen Peroxide Gas Generator Cycle with a Reciprocating Pump

    SciTech Connect

    Whitehead, J C

    2002-06-11

    A four-chamber piston pump is powered by decomposed 85% hydrogen peroxide. The performance envelope of the evolving 400 gram pump has been expanded to 172 cc/s water flow at discharge pressures near 5 MPa. A gas generator cycle system using the pump has been tested under similar conditions of pressure and flow. The powerhead gas is derived from a small fraction of the pumped hydrogen peroxide, and the system starts from tank pressures as low as 0.2 MPa. The effects of steam condensation on performance have been evaluated.

  13. Degradation of medical-grade polyurethane elastomers: the effect of hydrogen peroxide in vitro.

    PubMed

    Meijs, G F; McCarthy, S J; Rizzardo, E; Chen, Y C; Chatelier, R C; Brandwood, A; Schindhelm, K

    1993-03-01

    Treatment of Pellethane 2363-80A--a medical-grade poly(tetramethylene oxide)-based polyurethane elastomer--with 25% (w/w) hydrogen peroxide at 100 degrees C for times ranging from 24 h to 336 h led to significant decreases in ultimate tensile properties and decreases in molecular weight, both at the surface and in the bulk. IR spectral changes were similar to those observed after degradation in vivo. Differential scanning calorimetry showed that hydrogen-peroxide-induced degradation was associated with greater order in the hard domain and greater mobility in the soft domain. Studies conducted with low-molecular-weight model compounds for the hard and soft segments confirmed that methylene groups adjacent to oxygen were susceptible toward oxidation. The extent of degradation of a series of commercial polyurethanes on treatment with hydrogen peroxide (25%, 24 h, 100 degrees C) correlated well with their reported susceptibility to environmental stress cracking in vivo. PMID:8360204

  14. Distillation Kinetics of Solid Mixtures of Hydrogen Peroxide and Water and the Isolation of Pure Hydrogen Peroxide in Ultrahigh Vacuum

    NASA Technical Reports Server (NTRS)

    Teolis, B. D.; Baragiola, R. A.

    2006-01-01

    We present results of the growth of thin films of crystalline H2O2 and H2O2.2H2O (dihydrate) in ultrahigh vacuum by distilling an aqueous solution of hydrogen peroxide. We traced the process using infrared reflectance spectroscopy, mass loss on a quartz crystal microbalance, and in a few cases ultraviolet-visible reflectance. We find that the different crystalline phases-water, dihydrate, and hydrogen peroxide-have very different sublimation rates, making distillation efficient to isolate the less volatile component, crystalline H2O2.

  15. Oxygen Mass Flow Rate Generated for Monitoring Hydrogen Peroxide Stability

    NASA Technical Reports Server (NTRS)

    Ross, H. Richard

    2002-01-01

    Recent interest in propellants with non-toxic reaction products has led to a resurgence of interest in hydrogen peroxide for various propellant applications. Because peroxide is sensitive to contaminants, material interactions, stability and storage issues, monitoring decomposition rates is important. Stennis Space Center (SSC) uses thermocouples to monitor bulk fluid temperature (heat evolution) to determine reaction rates. Unfortunately, large temperature rises are required to offset the heat lost into the surrounding fluid. Also, tank penetration to accomodate a thermocouple can entail modification of a tank or line and act as a source of contamination. The paper evaluates a method for monitoring oxygen evolution as a means to determine peroxide stability. Oxygen generation is not only directly related to peroxide decomposition, but occurs immediately. Measuring peroxide temperature to monitor peroxide stability has significant limitations. The bulk decomposition of 1% / week in a large volume tank can produce in excess of 30 cc / min. This oxygen flow rate corresponds to an equivalent temperature rise of approximately 14 millidegrees C, which is difficult to measure reliably. Thus, if heat transfer were included, there would be no temperature rise. Temperature changes from the surrounding environment and heat lost to the peroxide will also mask potential problems. The use of oxygen flow measurements provides an ultra sensitive technique for monitoring reaction events and will provide an earlier indication of an abnormal decomposition when compared to measuring temperature rise.

  16. Anti-oxidant effects of the extracts from the leaves of Chromolaena odorata on human dermal fibroblasts and epidermal keratinocytes against hydrogen peroxide and hypoxanthine-xanthine oxidase induced damage.

    PubMed

    Thang, P T; Patrick, S; Teik, L S; Yung, C S

    2001-06-01

    In cutaneous tissue repair, oxidants and antioxidants play very important roles. In local acute and chronic wounds, oxidants are known to have the ability to cause as cell damage and may function as inhibitory factors to wound healing. The administration of anti-oxidants or free radical scavengers is reportedly helpful, notably in order to limit the delayed sequelae of thermal trauma and to enhance the healing process. Extracts from the leaves of Chromolaena odorata have been shown to be beneficial for treatment of wounds. Studies in vitro of these extracts demonstrated enhanced proliferation of fibroblasts, endothelial cells and keratinocytes, stimulation of keratinocyte migration in an in vitro wound assay, up-regulation of production by keratinocytes of extracellular matrix proteins and basement membrane components, and inhibition of collagen lattice contraction by fibroblasts. In this study, the anti-oxidant effects of both total ethanol and polyphenolic extracts from the plant leaves on hydrogen peroxide and hypoxanthine-xanthine oxidase induced damage to human fibroblasts and keratinocytes were investigated. Cell viability was monitored by a colorimetric assay. The results showed that for fibroblasts, toxicity of hydrogen peroxide or hypoxanthine xanthine oxidase on cells was dose-dependent. Total ethanol extract (TEE) at 400 and 800 microg/ml showed maximum and consistent protective cellular effect on oxidant toxicity at low or high doses of oxidants. The 50 microg/ml concentration of TEE also had significant and slightly protective effects on fibroblasts against hydrogen peroxide and hypoxanthine-xanthine oxidase induced damage, respectively. For keratinocytes, a dose-dependent relationship of oxidant toxicity was only seen with hydrogen peroxide but the protective action of the extract correlated with oxidant dosage. TEE at 400 and 800 microg/ml showed dose-dependent effects with both low and high concentration of oxidants. TEE at 50 microg/ml had no

  17. Hydrogen peroxide evolution during V-UV photolysis of water.

    PubMed

    Azrague, Kamal; Bonnefille, Eric; Pradines, Vincent; Pimienta, Véronique; Oliveros, Esther; Maurette, Marie-Thérèse; Benoit-Marquié, Florence

    2005-05-01

    Hydrogen peroxide evolution during the vacuum-ultraviolet (V-UV, 172 nm) photolysis of water is considerably affected by the presence of oxalic acid (employed as a model water pollutant) and striking differences are observed in the absence and in the presence of dioxygen.

  18. Hydrogen peroxide fuels aging, inflammation, cancer metabolism and metastasis

    PubMed Central

    Martinez-Outschoorn, Ubaldo E; Lin, Zhao; Pavlides, Stephanos; Whitaker-Menezes, Diana; Pestell, Richard G; Howell, Anthony

    2011-01-01

    In 1889, Dr. Stephen Paget proposed the “seed and soil” hypothesis, which states that cancer cells (the seeds) need the proper microenvironment (the soil) for them to grow, spread and metastasize systemically. In this hypothesis, Dr. Paget rightfully recognized that the tumor microenvironment has an important role to play in cancer progression and metastasis. In this regard, a series of recent studies have elegantly shown that the production of hydrogen peroxide, by both cancer cells and cancer-associated fibroblasts, may provide the necessary “fertilizer,” by driving accelerated aging, DNA damage, inflammation and cancer metabolism, in the tumor microenvironment. By secreting hydrogen peroxide, cancer cells and fibroblasts are mimicking the behavior of immune cells (macrophages/neutrophils), driving local and systemic inflammation, via the innate immune response (NFκB). Thus, we should consider using various therapeutic strategies (such as catalase and/or other antioxidants) to neutralize the production of cancer-associated hydrogen peroxide, thereby preventing tumor-stroma co-evolution and metastasis. The implications of these findings for overcoming chemo-resistance in cancer cells are also discussed in the context of hydrogen peroxide production and cancer metabolism. PMID:21734470

  19. Hydrogen peroxide as a fungicide for fish culture

    USGS Publications Warehouse

    Dawson, V.K.; Rach, J.J.; Schreier, T.M.

    1994-01-01

    Antifungal agents are needed to maintain healthy stocks of fish in the intensive culture systems currently employed in fish hatcheries. Malachite green has been the most widely used antifungal agent; however, its potential for producing teratology in animals and fish precludes further use in fish culture. Preliminary studies at the National Fisheries Research Center, La Crosse, WI, USA (La Crosse Center) indicate that hydrogen peroxide is effective for control of Saprolegnia sp. fungus on incubating eggs of rainbow trout. It is also effective against a wide variety of other organisms such as bacteria, yeasts, viruses, and spores, and has been proposed as a treatment for sea lice on salmon. Hydrogen peroxide and its primary decomposition products, oxygen and water, are not systemic poisons and are considered environmentally compatible. In response to a petition from the La Crosse Center, the U.S. Food and Drug Administration (FDA) recently classified hydrogen peroxide as a 'low regulatory priority' when used for control of fungus on fish and fish eggs. Preliminary tests conducted at the La Crosse Center suggest that prophylactic treatments of 250 to 500 ppm (based on 100% active ingredient) for 15 minutes every other day will inhibit fungal infections on healthy rainbow trout (Oncorhynchus mykiss) eggs. This treatment regime also seems to inhibit fungal development and increase hatching success among infected eggs. Efficacy and safety of hydrogen peroxide as a fungicide for fish are currently being evaluated.

  20. Hydrogen peroxide in sulfuric acid extraction of uranium ores

    SciTech Connect

    DeVries, F.W.

    1984-01-10

    Uranium can be extracted from its ores at a pH of 2.5 to 5.5 using sulfuric acid, hydrogen peroxide, trace of iron and a sulfate. The extraction process is applicable to both tank leaching of conventionally mined ores and in situ leaching.

  1. Inactivation of penicillin G in milk using hydrogen peroxide.

    PubMed

    Hanway, W H; Hansen, A P; Anderson, K L; Lyman, R L; Rushing, J E

    2005-02-01

    Milk antibiotic residues have been a public concern in recent years. The Grade A Pasteurized Milk Ordinance mandates that raw Grade A milk will test negative for beta-lactam antibiotic residues before processing. The purpose of this research was to investigate the ability of various levels of peroxide and heat to inactivate penicillin G in raw milk. Whole milk spiked to a mean of 436 +/- 15.1 (standard error of the mean) ppb of potassium penicillin G was treated with hydrogen peroxide at levels of 0.0, 0.09, 0.17, and 0.34%. Samples at each peroxide level (n = 6 per treatment) were treated as follows: 1) incubated at 54.4 degrees C for 3 h, 2) pasteurized at 62.8 degrees C for 30 min, 3) incubated and pasteurized as in treatments 1 and 2, or 4) received no further treatment. A beta-lactam competitive microbial receptor assay was used for quantification of penicillin G. Concentrations of penicillin in selected samples were determined by HPLC for a comparison of test methods. Treatments were evaluated relative to their ability to reduce milk penicillin G levels to below the safe level of 5 ppb. The 0.09% hydrogen peroxide level was ineffective for all treatments. Hydrogen peroxide at 0.17% lowered the mean penicillin G (+/- SEM) from 436 +/- 15.1 to 6 +/- 1.49 ppb using the incubated and pasteurized heat treatment. The 0.34% concentration of hydrogen peroxide was the most effective, inactivating penicillin G to a level well below the safe level of 5 ppb with the pasteurized heat treatment, with or without incubation.

  2. Toxicity of hydrogen peroxide treatments to rainbow trout eggs

    USGS Publications Warehouse

    Gaikowski, M.P.; Rach, J.J.; Olson, J.J.; Ramsay, R.T.

    1998-01-01

    Hydrogen peroxide treatments of 0, 500, 1,000, and 3,000 I?L/L, concentrations that were multiples of the Low Regulatory Priority limit of 500 I?L/L, were administered for 15 min every weekday (Mondaya??Friday) to eggs of rainbow trout Oncorhynchus mykiss and steelhead (anadromous rainbow trout) to determine the margin of safety existing for standard egg treatments. All untreated and treated eggs remained free of fungal infection throughout incubation. Hydrogen peroxide treatment reduced the mean percent hatch of rainbow trout eggs by 1.4a??5.9% among those treated at 500 I?L/L, 6.8a??15.4% among those treated at 1,000 I?L/L, and 13.2a??25.3% among those treated at 3,000 I?L/L. Mean percent hatch of rainbow trout eggs treated at 1,000 I?L H2O2/L was 7% lower than that for eggs treated at 500 I?L H2O2/L. Mean percent hatch of Skamania strain steelhead was significantly reduced by hydrogen peroxide treatment, whereas the mean percent hatch of Ganaraska strain steelhead was similar to the mean percent hatch of rainbow trout eggs. Daily percent mortality of rainbow trout eggs increased significantly from day 6 to day 10 (78a??135 daily temperature units, DTUsA?C) of incubation. Discontinuing hydrogen peroxide treatments to Skamania strain steelhead eggs from day 7 to day 11 (78a??105 DTUsA?C) of incubation significantly increased the probability of eggs reaching the eyed egg stage. The mean percent hatch of rainbow trout eggs treated with hydrogen peroxide at concentrations up to 1,000 I?L/L may be increased if no treatments are administered between 70 and 140 DTUsA?C. Mortality of sac fry was not observed at hydrogen peroxide concentrations of 1,000 I?L/L or lower. Fish culturists should be aware that other species or strains may be more sensitive than rainbow trout. Other species and strains should be initially treated with hydrogen peroxide at 500 I?L/L until monitoring of egg mortality identifies the presence or absence of a sensitive period.

  3. Impairment of phagocytic functions of alveolar macrophages by hydrogen peroxide

    SciTech Connect

    Oosting, R.S.; van Bree, L.; van Iwaarden, J.F.; van Golde, L.M.; Verhoef, J. )

    1990-08-01

    Hydrogen peroxide (H2O2) inhibited phagocytosis and superoxide anion production by rat alveolar macrophages. The inhibition was irreversible and concentration and exposure time dependent. The potential relationship between H2O2-induced biochemical perturbations and impaired alveolar macrophage phagocytic functions was investigated. Alveolar macrophage viability and Fc receptor binding capacity were not affected by H2O2. There was probably no correlation between a H2O2-induced rise in cytosolic (Ca2+) ((Ca2+)i) and the impairment of phagocytosis by alveolar macrophages, as was suggested by the following findings. First, the H2O2-induced rise in (Ca2+)i could be inhibited by chelation of extracellular Ca2+, whereas the H2O2-induced impairment of phagocytosis could not. Second, the H2O2-induced rise in (Ca2+)i was reversible, whereas the impairment of phagocytosis was not. And finally, a rise in (Ca2+)i by incubation of alveolar macrophages with the calcium ionophore A23187 did not affect phagocytosis. Various experiments suggested that ATP depletion may play an important role in the H2O2 toxicity for alveolar macrophages. Comparable concentrations of H2O2 caused an irreversible decrease both in cellular ATP and in phagocytosis and superoxide production by alveolar macrophages. In addition, time course of ATP depletion and induction of impaired alveolar macrophage function were similar. In view of the fact that the strong oxidant H2O2 may react with a large variety of biological substances, possible other toxic lesions may not be excluded as underlying mechanism for H2O2-induced inhibition of phagocytic functions of alveolar macrophages.

  4. Endothelial activation by hydrogen peroxide. Selective increases of intercellular adhesion molecule-1 and major histocompatibility complex class I.

    PubMed Central

    Bradley, J. R.; Johnson, D. R.; Pober, J. S.

    1993-01-01

    Products of activated leukocytes may alter vascular endothelial cell (EC) function. For example, ECs respond to leukocyte-derived cytokines, such as tumor necrosis factor (TNF) or interleukin-1, by reversibly altering levels of expression of specific gene products that promote inflammation. In contrast, hydrogen peroxide, a product of TNF-activated neutrophils, can produce irreversible EC injury and death. In this study, we have investigated the effects of subinjurious concentrations of hydrogen peroxide on EC inflammatory functions. Treatment with 50 to 100 mumol/L hydrogen peroxide selectively increases surface expression of intercellular adhesion molecule-1 and major histocompatibility complex class I, but not endothelial leukocyte adhesion molecule-1 (also known as E-selectin), vascular cell adhesion molecule-1, or gp96, a constitutively expressed EC surface protein. Increased major histocompatibility complex class I and intercellular adhesion molecule-1 surface expression is associated with specifically increased messenger RNA levels, suggesting selective endothelial gene activation. Hydrogen peroxide does not activate the transcription factor Nuclear Factor kappa B, an important mediator of TNF-induced gene expression. Co-treatment with hydrogen peroxide inhibits TNF-induced gene expression at 4 hours, an effect which can be attributed to reversible inhibition of TNF binding to EC surface receptors. Hydrogen peroxide also antagonizes the actions of interleukin-1. At 24 hours, TNF and hydrogen peroxide produce, at most, additive increases in intercellular adhesion molecule-1 and major histocompatibility complex class I. These results suggest that subinjurious concentrations of hydrogen peroxide can activate endothelium and that the effects of hydrogen peroxide on ECs differ from those of inflammatory cytokines. Images Figure 3 Figure 4 Figure 5 PMID:8098585

  5. Chloroplastic NADPH oxidase-like activity-mediated perpetual hydrogen peroxide generation in the chloroplast induces apoptotic-like death of Brassica napus leaf protoplasts.

    PubMed

    Tewari, Rajesh Kumar; Watanabe, Daisuke; Watanabe, Masami

    2012-01-01

    Despite extensive research over the past years, regeneration from protoplasts has been observed in only a limited number of plant species. Protoplasts undergo complex metabolic modification during their isolation. The isolation of protoplasts induces reactive oxygen species (ROS) generation in Brassica napus leaf protoplasts. The present study was conducted to provide new insight into the mechanism of ROS generation in B. napus leaf protoplasts. In vivo localization of H(2)O(2) and enzymes involved in H(2)O(2) generation and detoxification, molecular antioxidant-ascorbate and its redox state and lipid peroxidation were investigated in the leaf and isolated protoplasts. Incubating leaf strips in the macerating enzyme (ME) for different duration (3, 6, and 12 h) induced accumulation of H(2)O(2) and malondialdehyde (lipid peroxidation, an index of membrane damage) in protoplasts. The level of H(2)O(2) was highest just after protoplast isolation and subsequently decreased during culture. Superoxide generating NADPH oxidase (NOX)-like activity was enhanced, whereas superoxide dismutase (SOD) and ascorbate peroxidase (APX) decreased in the protoplasts compared to leaves. Diaminobenzidine peroxidase (DAB-POD) activity was also lower in the protoplasts compared to leaves. Total ascorbate content, ascorbate to dehydroascorbate ratio (redox state), were enhanced in the protoplasts compared to leaves. Higher activity of NOX-like enzyme and weakening in the activity of antioxidant enzymes (SOD, APX, and DAB-POD) in protoplasts resulted in excessive accumulation of H(2)O(2) in chloroplasts of protoplasts. Chloroplastic NADPH oxidase-like activity mediated perpetual H(2)O(2) generation probably induced apoptotic-like cell death of B. napus leaf protoplasts as indicated by parallel DNA laddering and decreased mitochondrial membrane potential. PMID:21853253

  6. Chloroplastic NADPH oxidase-like activity-mediated perpetual hydrogen peroxide generation in the chloroplast induces apoptotic-like death of Brassica napus leaf protoplasts.

    PubMed

    Tewari, Rajesh Kumar; Watanabe, Daisuke; Watanabe, Masami

    2012-01-01

    Despite extensive research over the past years, regeneration from protoplasts has been observed in only a limited number of plant species. Protoplasts undergo complex metabolic modification during their isolation. The isolation of protoplasts induces reactive oxygen species (ROS) generation in Brassica napus leaf protoplasts. The present study was conducted to provide new insight into the mechanism of ROS generation in B. napus leaf protoplasts. In vivo localization of H(2)O(2) and enzymes involved in H(2)O(2) generation and detoxification, molecular antioxidant-ascorbate and its redox state and lipid peroxidation were investigated in the leaf and isolated protoplasts. Incubating leaf strips in the macerating enzyme (ME) for different duration (3, 6, and 12 h) induced accumulation of H(2)O(2) and malondialdehyde (lipid peroxidation, an index of membrane damage) in protoplasts. The level of H(2)O(2) was highest just after protoplast isolation and subsequently decreased during culture. Superoxide generating NADPH oxidase (NOX)-like activity was enhanced, whereas superoxide dismutase (SOD) and ascorbate peroxidase (APX) decreased in the protoplasts compared to leaves. Diaminobenzidine peroxidase (DAB-POD) activity was also lower in the protoplasts compared to leaves. Total ascorbate content, ascorbate to dehydroascorbate ratio (redox state), were enhanced in the protoplasts compared to leaves. Higher activity of NOX-like enzyme and weakening in the activity of antioxidant enzymes (SOD, APX, and DAB-POD) in protoplasts resulted in excessive accumulation of H(2)O(2) in chloroplasts of protoplasts. Chloroplastic NADPH oxidase-like activity mediated perpetual H(2)O(2) generation probably induced apoptotic-like cell death of B. napus leaf protoplasts as indicated by parallel DNA laddering and decreased mitochondrial membrane potential.

  7. Hydrogen peroxide oxidant fuel cell systems for ultra-portable applications

    NASA Technical Reports Server (NTRS)

    Valdez, T. I.; Narayanan, S. R.

    2001-01-01

    This paper will address the issues of using hydrogen peroxide as an oxidant fuel in a miniature DMFC system. Cell performance for DMFC based fuel cells operating on hydrogen peroxide will be presented and discussed.

  8. Contact Lens Solutions With Hydrogen Peroxide: To Avoid Injury, Follow All Instructions

    MedlinePlus

    ... For Consumers Consumer Updates Contact Lens Solutions With Hydrogen Peroxide: To Avoid Injury, Follow All Instructions Share Tweet ... Program . back to top Checklist for Solutions With Hydrogen Peroxide Talk to your eye-care provider before deciding ...

  9. 78 FR 73697 - New Animal Drugs; Hyaluronate Sodium; Hydrogen Peroxide; Imidacloprid and Moxidectin; Change of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-09

    ...; Hyaluronate Sodium; Hydrogen Peroxide; Imidacloprid and Moxidectin; Change of Sponsor AGENCY: Food and Drug... interest in, NADA 141-255 for PEROX-AID (hydrogen peroxide) 35% Solution to Western Chemical, Inc.,...

  10. Application of a newly developed hydrogen peroxide vapor phase sensor to HPV sterilizer.

    PubMed

    Taizo, I; Sinichi, A; Kawamura, K

    1998-01-01

    A new type of concentration sensor for hydrogen peroxide vapor has been developed by making use of a semiconductor. Output from the vapor sensor has been shown to have a good linear relationship with the logarithm of the concentration of hydrogen peroxide vapor. Concentration of hydrogen peroxide vapor introduced into the sterilization chamber could be kept constant by monitoring the concentration of the hydrogen peroxide vapor continuously and controlling the vapor supply. Temperature and humidity have also been kept constant. D-values for B. stearothermophilus ATCC 12980 at various concentrations of hydrogen peroxide vapor have been determined by using the combination system of the hydrogen peroxide vapor sensor, the hydrogen peroxide vapor supplier, thermosensor and humidity sensor. D-values at the temperature of 30 degrees C and the absolute humidity of 0.7 mg H2O/L thus obtained, were 0.2 minutes at hydrogen peroxide concentration of 600 ppm and 1.2 minutes at 200 ppm at the temperature of 30 degrees C and 0.7 mg/L absolute humidity. D-values for B. stearothermophilus ATCC 12980 at various temperatures, humidity and levels of hydrogen peroxide concentration have also been determined. These fundamental data indicate that the sterilization by hydrogen peroxide vapor can be validated as precisely as steam sterilization by measuring and controlling the concentration of hydrogen peroxide vapor using a combination of the hydrogen peroxide concentration sensor and the vapor generator. Influence of temperature and humidity have also been studied. The hydrogen peroxide sensor has been calibrated and standardized by using the standard hydrogen peroxide vapor whose concentration has been determined by calculating partial pressure of hydrogen peroxide over the water-hydrogen peroxide solution. PMID:9542409

  11. Protective Effects of Coenzyme Q10 Against Hydrogen Peroxide-Induced Oxidative Stress in PC12 Cell: The Role of Nrf2 and Antioxidant Enzymes.

    PubMed

    Li, Li; Du, Jikun; Lian, Yaru; Zhang, Yun; Li, Xingren; Liu, Ying; Zou, Liyi; Wu, Tie

    2016-01-01

    Oxidative stress is a major component of harmful cascades activated in neurodegenerative disorders. Coenzyme Q10 (CoQ10), an essential component in the mitochondrial respiratory chain, has recently gained attention for its potential role in the treatment of neurodegenerative disease. Here, we investigated the possible protective effects of CoQ10 on H2O2-induced neurotoxicity in PC12 cells and the underlying mechanism. CoQ10 showed high free radical-scavenging activity as measured by a DPPH and TEAC. Pre-treatment of cells with CoQ10 diminished intracellular generation of ROS in response to H2O2. H2O2 decreased viability of PC12 cells which was reversed by pretreatment with CoQ10 according to MTT assay. H2O2-induced lipid peroxidation was attenuated by CoQ10 as shown by inhibition of MDA formation. Furthermore, pre-incubation of the cells with CoQ10 also restored the activity of cellular antioxidant enzymes which had been altered by H2O2. Moreover, CoQ10 induced Nrf2 nuclear translocation, the upstream of antioxidant enzymes. These findings suggest CoQ10 augments cellular antioxidant defense capacity through both intrinsic free radical-scavenging activity and activation of Nrf2 and subsequently antioxidant enzymes induction, thereby protecting the PC12 cells from H2O2-induced oxidative cytotoxicity.

  12. 40 CFR 180.1197 - Hydrogen peroxide; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Hydrogen peroxide; exemption from the... Exemptions From Tolerances § 180.1197 Hydrogen peroxide; exemption from the requirement of a tolerance. An exemption from the requirement of a tolerance is established for residues of hydrogen peroxide in or on...

  13. 21 CFR 172.167 - Silver nitrate and hydrogen peroxide solution.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Silver nitrate and hydrogen peroxide solution. 172... FOOD FOR HUMAN CONSUMPTION Food Preservatives § 172.167 Silver nitrate and hydrogen peroxide solution. An aqueous solution containing a mixture of silver nitrate and hydrogen peroxide may be safely...

  14. 40 CFR 415.90 - Applicability; description of the hydrogen peroxide production subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... hydrogen peroxide production subcategory. 415.90 Section 415.90 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Hydrogen Peroxide Production Subcategory § 415.90 Applicability; description of the hydrogen peroxide production subcategory. The provisions of this subpart are applicable to...

  15. 40 CFR 180.1197 - Hydrogen peroxide; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Hydrogen peroxide; exemption from the... Exemptions From Tolerances § 180.1197 Hydrogen peroxide; exemption from the requirement of a tolerance. An exemption from the requirement of a tolerance is established for residues of hydrogen peroxide in or on...

  16. 40 CFR 180.1197 - Hydrogen peroxide; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Hydrogen peroxide; exemption from the... Exemptions From Tolerances § 180.1197 Hydrogen peroxide; exemption from the requirement of a tolerance. An exemption from the requirement of a tolerance is established for residues of hydrogen peroxide in or on...

  17. 21 CFR 172.167 - Silver nitrate and hydrogen peroxide solution.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Silver nitrate and hydrogen peroxide solution. 172... Preservatives § 172.167 Silver nitrate and hydrogen peroxide solution. An aqueous solution containing a mixture of silver nitrate and hydrogen peroxide may be safely used in accordance with the...

  18. 40 CFR 180.1197 - Hydrogen peroxide; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Hydrogen peroxide; exemption from the... Exemptions From Tolerances § 180.1197 Hydrogen peroxide; exemption from the requirement of a tolerance. An exemption from the requirement of a tolerance is established for residues of hydrogen peroxide in or on...

  19. 40 CFR 415.90 - Applicability; description of the hydrogen peroxide production subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... hydrogen peroxide production subcategory. 415.90 Section 415.90 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Hydrogen Peroxide Production Subcategory § 415.90 Applicability; description of the hydrogen peroxide production subcategory. The provisions of this subpart are applicable to...

  20. 21 CFR 172.167 - Silver nitrate and hydrogen peroxide solution.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Silver nitrate and hydrogen peroxide solution. 172... FOOD FOR HUMAN CONSUMPTION Food Preservatives § 172.167 Silver nitrate and hydrogen peroxide solution. An aqueous solution containing a mixture of silver nitrate and hydrogen peroxide may be safely...

  1. 40 CFR 180.1197 - Hydrogen peroxide; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Hydrogen peroxide; exemption from the... Exemptions From Tolerances § 180.1197 Hydrogen peroxide; exemption from the requirement of a tolerance. An exemption from the requirement of a tolerance is established for residues of hydrogen peroxide in or on...

  2. 21 CFR 172.167 - Silver nitrate and hydrogen peroxide solution.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Silver nitrate and hydrogen peroxide solution. 172... FOOD FOR HUMAN CONSUMPTION Food Preservatives § 172.167 Silver nitrate and hydrogen peroxide solution. An aqueous solution containing a mixture of silver nitrate and hydrogen peroxide may be safely...

  3. 21 CFR 172.167 - Silver nitrate and hydrogen peroxide solution.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Silver nitrate and hydrogen peroxide solution. 172... FOOD FOR HUMAN CONSUMPTION Food Preservatives § 172.167 Silver nitrate and hydrogen peroxide solution. An aqueous solution containing a mixture of silver nitrate and hydrogen peroxide may be safely...

  4. 40 CFR 415.90 - Applicability; description of the hydrogen peroxide production subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... hydrogen peroxide production subcategory. 415.90 Section 415.90 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Hydrogen Peroxide Production Subcategory § 415.90 Applicability; description of the hydrogen peroxide production subcategory. The provisions of this subpart are applicable to...

  5. 40 CFR 415.90 - Applicability; description of the hydrogen peroxide production subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... hydrogen peroxide production subcategory. 415.90 Section 415.90 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Hydrogen Peroxide Production Subcategory § 415.90 Applicability; description of the hydrogen peroxide production subcategory. The provisions of this subpart are applicable to...

  6. 40 CFR 415.90 - Applicability; description of the hydrogen peroxide production subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... hydrogen peroxide production subcategory. 415.90 Section 415.90 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Hydrogen Peroxide Production Subcategory § 415.90 Applicability; description of the hydrogen peroxide production subcategory. The provisions of this subpart are applicable to...

  7. Atrazine photodegradation in aqueous solution induced by interaction of humic acids and iron: photoformation of iron(II) and hydrogen peroxide.

    PubMed

    Ou, Xiaoxia; Quan, Xie; Chen, Shuo; Zhao, Huimin; Zhang, Yaobin

    2007-10-17

    The photochemical formation of Fe(II) and hydrogen peroxide (H 2O 2) coupled with humic acids (HA) was studied to understand the significance of iron cycling in the photodegradation of atrazine under simulated sunlight. The presence of HA significantly enhanced the formation of Fe(II) and H 2O 2, and their subsequent product, hydroxyl radical ( (*)OH), was the main oxidant responsible for the atrazine photodegradation. During 60 h of irradiation, the fraction of iron presented as Fe(II) (Fe(II)/Fe(t)) decreased from 20-32% in the presence of the Fe(III)-HA complex to 10-22% after adding atrazine. The rate of atrazine photodegradation in solutions containing Fe(III) increased with increasing HA concentration, suggesting that the complexation of Fe(III) with HA accelerated the Fe(III)/Fe(II) cycling. Using fluorescence spectrometry, the quenching constant and the percentage of fluorophores participating in the complexation of HA with Fe(III) were estimated by the modified Stern-Volmer equation. Fourier transform infrared spectroscopy (FTIR) offered the direct evidence that Fe(III)-carboxylate complex could be formed by ligand exchange of HA with Fe(III). Based on all the information, a possible reaction mechanism was proposed.

  8. Calcium release by ryanodine receptors mediates hydrogen peroxide-induced activation of ERK and CREB phosphorylation in N2a cells and hippocampal neurons.

    PubMed

    Kemmerling, Ulrike; Muñoz, Pablo; Müller, Marioly; Sánchez, Gina; Aylwin, María L; Klann, Eric; Carrasco, M Angélica; Hidalgo, Cecilia

    2007-05-01

    Hydrogen peroxide, which stimulates ERK phosphorylation and synaptic plasticity in hippocampal neurons, has also been shown to stimulate calcium release in muscle cells by promoting ryanodine receptor redox modification (S-glutathionylation). We report here that exposure of N2a cells or rat hippocampal neurons in culture to 200 microM H2O2 elicited calcium signals, increased ryanodine receptor S-glutathionylation, and enhanced both ERK and CREB phosphorylation. In mouse hippocampal slices, H2O2 (1 microM) also stimulated ERK and CREB phosphorylation. Preincubation with ryanodine (50 microM) largely prevented the effects of H2O2 on calcium signals and ERK/CREB phosphorylation. In N2a cells, the ERK kinase inhibitor U0126 suppressed ERK phosphorylation and abolished the stimulation of CREB phosphorylation produced by H2O2, suggesting that H2O2 enhanced CREB phosphorylation via ERK activation. In N2a cells in calcium-free media, 200 microM H2O2 stimulated ERK and CREB phosphorylation, while preincubation with thapsigargin prevented these enhancements. These combined results strongly suggest that H2O2 promotes ryanodine receptors redox modification; the resulting calcium release signals, by enhancing ERK activity, would increase CREB phosphorylation. We propose that ryanodine receptor stimulation by activity-generated redox species produces calcium release signals that may contribute significantly to hippocampal synaptic plasticity, including plasticity that requires long-lasting ERK-dependent CREB phosphorylation. PMID:17074386

  9. Hydrogen peroxide modified sodium titanates with improved sorption capabilities

    SciTech Connect

    Nyman, May D.; Hobbs, David T.

    2009-02-24

    The sorption capabilities (e.g., kinetics, selectivity, capacity) of the baseline monosodium titanate (MST) sorbent material currently being used to sequester Sr-90 and alpha-emitting radioisotopes at the Savannah River Site are significantly improved when treated with hydrogen peroxide; either during the original synthesis of MST, or, as a post-treatment step after the MST has been synthesized. It is expected that these peroxide-modified MST sorbent materials will have significantly improved sorption capabilities for non-radioactive cations found in industrial processes and waste streams.

  10. Protective Effects of Minor Components of Curcuminoids on Hydrogen Peroxide-Treated Human HaCaT Keratinocytes.

    PubMed

    Liu, Yuh-Hwa; Lin, Yin-Shiou; Huang, Yu-Wei; Fang, Sheng-Uei; Lin, Shyr-Yi; Hou, Wen-Chi

    2016-05-11

    Hydrogen peroxide, one of the reactive oxygen species (ROS), can cause intracellular oxidative stress associated with skin aging and/or photoaging. Curcumin, a polyphenol in turmeric, has been reported to exhibit biological activity. In this study, five naturally occurring curcuminoids [curcumin, demethoxycurcumin (DMC), bisdemethoxycurcumin (BDMC), monohydroxy-DMC, and monohydroxy-BDMC] were used to investigate their protective roles against hydrogen peroxide-induced oxidative stress in the immortalized human keratinocyte cell lines (HaCaT cells). These five curcuminoids at 10 μM, but not at 5 μM, were shown to exhibit cytotoxicities toward HaCaT keratinocytes. Therefore, a 5 μM concentration of the five curcuminoids was selected for further investigations. Cells were pretreated with or without curcuminoids for 2.5 h before 24-h hydrogen peroxide (150 μM) treatments. Pretreatments with the minor components monohydroxy-DMC or monohydroxy-BDMC, but not curcumin, DMC, and BDMC, showed protective activity, elevating cell viability compared to cells with direct hydrogen peroxide treatments. Pretreatments with monohydroxy-DMC and monohydroxy-BDMC showed the best protective effects, reducing apoptotic cell populations and intracellular ROS, as demonstrated by flow cytometry, as well as reducing the changes of the mitochondrial membrane potential compared to cells with direct hydrogen peroxide treatments. The pretreatments with monohydroxy-DMC and monohydroxy-BDMC reduced c-jun and c-fos mRNA expression and p53 tumor suppressor protein expression and increased HO-1 protein expression and glutathione peroxidase (GPx) activity, respectively, compared to cells with direct hydrogen peroxide treatments. The five curcuminoids exhibited similar hydrogen peroxide-scavenging activity in vitro. It was proposed that monohydroxy-DMC and monohydroxy-BDMC could induce antioxidant defense systems better than curcumin, DMC, or BDMC could against hydrogen peroxide-induced oxidative

  11. Paper-based vapor detection of hydrogen peroxide: colorimetric sensing with tunable interface.

    PubMed

    Xu, Miao; Bunes, Benjamin R; Zang, Ling

    2011-03-01

    Vapor detection of hydrogen peroxide still remains challenging for conventional sensing techniques, though such vapor detection implies important applications in various practical areas, including locating IEDs. We report herein a new colorimetric sensor system that can detect hydrogen peroxide vapor down to parts per billion level. The sensory materials are based on the cellulose microfibril network of paper towels, which provide a tunable interface for modification with Ti(IV) oxo complexes for binding and reacting with H(2)O(2). The Ti(IV)-peroxide bond thus formed turns the complex from colorless to bright yellow with an absorption maximum around 400 nm. Such complexation-induced color change is exclusively selective for hydrogen peroxide, with no color change observed in the presence of water, oxygen, common organic reagents or other chelating reagents. This paper-based sensor material is disposable and one-time use, representing a cheap, simple approach to detect peroxide vapors. The reported sensor system also proves the technical feasibility of developing enhanced colorimetric sensing using nanofibril materials that will provide plenty of room to enlarge the surface area (by shrinking the fiber size), so as to enhance the surface interaction with gas phase. PMID:21355618

  12. Specific aquaporins facilitate the diffusion of hydrogen peroxide across membranes.

    PubMed

    Bienert, Gerd P; Møller, Anders L B; Kristiansen, Kim A; Schulz, Alexander; Møller, Ian M; Schjoerring, Jan K; Jahn, Thomas P

    2007-01-12

    The metabolism of aerobic organisms continuously produces reactive oxygen species. Although potentially toxic, these compounds also function in signaling. One important feature of signaling compounds is their ability to move between different compartments, e.g. to cross membranes. Here we present evidence that aquaporins can channel hydrogen peroxide (H2O2). Twenty-four aquaporins from plants and mammals were screened in five yeast strains differing in sensitivity toward oxidative stress. Expression of human AQP8 and plant Arabidopsis TIP1;1 and TIP1;2 in yeast decreased growth and survival in the presence of H2O2. Further evidence for aquaporin-mediated H2O2 diffusion was obtained by a fluorescence assay with intact yeast cells using an intracellular reactive oxygen species-sensitive fluorescent dye. Application of silver ions (Ag+), which block aquaporin-mediated water diffusion in a fast kinetics swelling assay, also reversed both the aquaporin-dependent growth repression and the H2O2-induced fluorescence. Our results present the first molecular genetic evidence for the diffusion of H2O2 through specific members of the aquaporin family.

  13. Mononuclear Iron Enzymes Are Primary Targets of Hydrogen Peroxide Stress*

    PubMed Central

    Anjem, Adil; Imlay, James A.

    2012-01-01

    This study tested whether nonredox metalloenzymes are commonly charged with iron in vivo and are primary targets of oxidative stress because of it. Indeed, three sample mononuclear enzymes, peptide deformylase, threonine dehydrogenase, and cytosine deaminase, were rapidly damaged by micromolar hydrogen peroxide in vitro and in live Escherichia coli. The first two enzymes use a cysteine residue to coordinate the catalytic metal atom; it was quantitatively oxidized by the radical generated by the Fenton reaction. Because oxidized cysteine can be repaired by cellular reductants, the effect was to avoid irreversible damage to other active-site residues. Nevertheless, protracted H2O2 exposure gradually inactivated these enzymes, consistent with the overoxidation of the cysteine residue to sulfinic or sulfonic forms. During H2O2 stress, E. coli defended all three proteins by inducing MntH, a manganese importer, and Dps, an iron-sequestration protein. These proteins appeared to collaborate in replacing the iron atom with nonoxidizable manganese. The implication is that mononuclear metalloproteins are common targets of H2O2 and that both structural and metabolic arrangements exist to protect them. PMID:22411989

  14. Heme degradation upon production of endogenous hydrogen peroxide via interaction of hemoglobin with sodium dodecyl sulfate.

    PubMed

    Salehi, N; Moosavi-Movahedi, A A; Fotouhi, L; Yousefinejad, S; Shourian, M; Hosseinzadeh, R; Sheibani, N; Habibi-Rezaei, M

    2014-04-01

    In this study the hemoglobin heme degradation upon interaction with sodium dodecyl sulfate (SDS) was investigated using UV-vis and fluorescence spectroscopy, multivariate curve resolution analysis, and chemiluminescence method. Our results showed that heme degradation occurred during interaction of hemoglobin with SDS producing three fluorescent components. We showed that the hydrogen peroxide, produced during this interaction, caused heme degradation. In addition, the endogenous hydrogen peroxide was more effective in hemoglobin heme degradation compared to exogenously added hydrogen peroxide. The endogenous form of hydrogen peroxide altered oxyHb to aquamethemoglobin and hemichrome at low concentration. In contrast, the exogenous hydrogen peroxide lacked this ability under same conditions.

  15. Hydrogen peroxide regulated photosynthesis in C4-pepc transgenic rice.

    PubMed

    Ren, C G; Li, X; Liu, X L; Wei, X D; Dai, C C

    2014-01-01

    In this study, we investigated the photosynthetic physiological basis in 'PC' transgenic rice (Oryza sativa L.), showing high-level expression of the gene encoding C4 phosphoenolpyruvate carboxylase (pepc), by hydrogen peroxide (H2O2). The C4-PEPC gene (pepc) from maize in the transgenic rice plants was checked by PCR. Comparison of yield components and photosynthetic indices between PC and untransformed wild-type (WT) plants indicated that increased yield in PC was associated with higher net photosynthetic rate and higher activities of phosphoenolpyruvate carboxylase (PEPC). Both PC and WT plants were treated with 1 mmol L(-1) abscisic acid (ABA), 0.04% 1-butanol (BA), 2 mmol L(-1) neomycin (NS), or 2 mmol L(-1) diphenyleneiodonium chloride (DPI) to investigate the relationship between photosynthesis and levels of H2O2 and phosphatidic acid. In both PC and WT, ABA induced H2O2 generation and simultaneous decrease in stomatal conductance (g(s)). PC plants treated with BA showed decreased H2O2 content and strongly increased g(s) within 2 h of treatment. Similar results were observed in response to DPI treatment in PC. However, WT did not observe the decrease of H2O2 during the treatments of BA and DPI. The reduced H2O2 content in PC caused by BA treatment differed to that induced by DPI because BA did not inhibit NADPH oxidase activities. While BA induced a larger PEPC activity in PC, and higher catalase activity as well. These results indicated that the regulation of endogenous H2O2 metabolism of PC could be helpful for enhancing photosynthetic capability.

  16. Quantification of peroxide ion passage in dentin, enamel, and cementum after internal bleaching with hydrogen peroxide.

    PubMed

    Palo, R M; Bonetti-Filho, I; Valera, M C; Camargo, C H R; Camargo, Sea; Moura-Netto, C; Pameijer, C

    2012-01-01

    The aim of this study was to evaluate the amount of peroxide passage from the pulp chamber to the external enamel surface during the internal bleaching technique. Fifty bovine teeth were sectioned transversally 5 mm below the cemento-enamel junction (CEJ), and the remaining part of the root was sealed with a 2-mm layer of glass ionomer cement. The external surface of the samples was coated with nail varnish, with the exception of standardized circular areas (6-mm diameter) located on the enamel, exposed dentin, or cementum surface of the tooth. The teeth were divided into three experimental groups according to exposed areas close to the CEJ and into two control groups (n=10/group), as follows: GE, enamel exposure area; GC, cementum exposed area; GD, dentin exposed area; Negative control, no presence of internal bleaching agent and uncoated surface; and Positive control, pulp chamber filled with bleaching agent and external surface totally coated with nail varnish. The pulp chamber was filled with 35% hydrogen peroxide (Opalescence Endo, Ultradent). Each sample was placed inside of individual flasks with 1000 μL of acetate buffer solution, 2 M (pH 4.5). After seven days, the buffer solution was transferred to a glass tube, in which 100 μL of leuco-crystal violet and 50 μL of horseradish peroxidase were added, producing a blue solution. The optical density of the blue solution was determined by spectrophotometer and converted into microgram equivalents of hydrogen peroxide. Data were submitted to Kruskal-Wallis and Dunn-Bonferroni tests (α=0.05). All experimental groups presented passage of peroxide to the external surface that was statistically different from that observed in the control groups. It was verified that the passage of peroxide was higher in GD than in GE (p<0.01). The GC group presented a significantly lower peroxide passage than did GD and GE (p<0.01). It can be concluded that the hydrogen peroxide placed into the pulp chamber passed through the

  17. Quantification of peroxide ion passage in dentin, enamel, and cementum after internal bleaching with hydrogen peroxide.

    PubMed

    Palo, R M; Bonetti-Filho, I; Valera, M C; Camargo, C H R; Camargo, Sea; Moura-Netto, C; Pameijer, C

    2012-01-01

    The aim of this study was to evaluate the amount of peroxide passage from the pulp chamber to the external enamel surface during the internal bleaching technique. Fifty bovine teeth were sectioned transversally 5 mm below the cemento-enamel junction (CEJ), and the remaining part of the root was sealed with a 2-mm layer of glass ionomer cement. The external surface of the samples was coated with nail varnish, with the exception of standardized circular areas (6-mm diameter) located on the enamel, exposed dentin, or cementum surface of the tooth. The teeth were divided into three experimental groups according to exposed areas close to the CEJ and into two control groups (n=10/group), as follows: GE, enamel exposure area; GC, cementum exposed area; GD, dentin exposed area; Negative control, no presence of internal bleaching agent and uncoated surface; and Positive control, pulp chamber filled with bleaching agent and external surface totally coated with nail varnish. The pulp chamber was filled with 35% hydrogen peroxide (Opalescence Endo, Ultradent). Each sample was placed inside of individual flasks with 1000 μL of acetate buffer solution, 2 M (pH 4.5). After seven days, the buffer solution was transferred to a glass tube, in which 100 μL of leuco-crystal violet and 50 μL of horseradish peroxidase were added, producing a blue solution. The optical density of the blue solution was determined by spectrophotometer and converted into microgram equivalents of hydrogen peroxide. Data were submitted to Kruskal-Wallis and Dunn-Bonferroni tests (α=0.05). All experimental groups presented passage of peroxide to the external surface that was statistically different from that observed in the control groups. It was verified that the passage of peroxide was higher in GD than in GE (p<0.01). The GC group presented a significantly lower peroxide passage than did GD and GE (p<0.01). It can be concluded that the hydrogen peroxide placed into the pulp chamber passed through the

  18. Ozonation of deciduous wood in the presence of hydrogen peroxide

    NASA Astrophysics Data System (ADS)

    Mamleeva, N. A.; Kharlanov, A. N.; Fionov, A. V.; Lunin, V. V.

    2011-10-01

    The kinetic curves of the dependence of ozone specific absorption ( Q r, sp ) upon aspen wood ozonation in the presence and absence of hydrogen peroxide are obtained. It is established that the rate of ozone and Q r, sp absorption increase in the O3/H2O2 system. It is demonstrated by ESR, IR, and UV spectroscopy of diffuse reflection that wood ozonation in the O3/H2O2 system results in the destruction of lignin aromatic and quinoid structures. The ozonation process in the presence of H2O2 is accompanied by destruction of the carbohydrate component of the lignocarbohydrate complex. We conclude that O3/H2O2 can be used in the deep delignification of wood. It is shown that the presence of hydrogen peroxide upon ozonation increases the efficiency of the process, allowing its duration and total ozone consumption to be reduced.

  19. Response of Mouse Zygotes Treated with Mild Hydrogen Peroxide as a Model to Reveal Novel Mechanisms of Oxidative Stress-Induced Injury in Early Embryos

    PubMed Central

    2016-01-01

    Our study aimed to develop embryo models to evaluate the impact of oxidative stress on embryo development. Mouse zygotes, which stayed at G1 phase, were treated with prepared culture medium (containing 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, or 0.1 mM hydrogen peroxide (H2O2)) for 30 min in experiment 1. The dose-effects of H2O2 on embryo development were investigated via comparisons of the formation rate at each stage (2- and 4-cell embryos and blastocysts). Experiment 2 was carried out to compare behaviors of embryos in a mild oxidative-stressed status (0.03 mM H2O2) with those in a control (0 mM H2O2). Reactive oxygen species (ROS) levels, variation of mitochondrial membrane potential (MMP), expression of γH2AX, and cell apoptosis rate of blastocyst were detected. We observed a dose-dependent decrease on cleavage and blastocyst rates. Besides, higher level of ROS, rapid reduction of MMP, and the appearance of γH2AX revealed that embryos are injured early in mild oxidative stress. Additionally, γH2AX may involve during DNA damage response in early embryos. And the apoptotic rate of blastocyst may significantly increase when DNA damage repair is inadequate. Most importantly, our research provides embryo models to study cell cycle regulation and DNA damage response under condition of different levels of oxidative stress. PMID:27738489

  20. Ybp1 and Gpx3 Signaling in Candida albicans Govern Hydrogen Peroxide-Induced Oxidation of the Cap1 Transcription Factor and Macrophage Escape

    PubMed Central

    Patterson, Miranda J.; McKenzie, Christopher G.; Smith, Deborah A.; da Silva Dantas, Alessandra; Sherston, Sam; Veal, Elizabeth A.; Morgan, Brian A.; MacCallum, Donna M.

    2013-01-01

    Abstract Aims: As Candida albicans is the major fungal pathogen of humans, there is an urgent need to understand how this pathogen evades toxic reactive oxygen species (ROS) generated by the host immune system. A key regulator of antioxidant gene expression, and thus ROS resistance, in C. albicans is the AP-1-like transcription factor Cap1. Despite this, little is known regarding the intracellular signaling mechanisms that underlie the oxidation and activation of Cap1. Therefore, the aims of this study were; (i) to identify the regulatory proteins that govern Cap1 oxidation, and (ii) to investigate the importance of Cap1 oxidation in C. albicans pathogenesis. Results: In response to hydrogen peroxide (H2O2), but not glutathione-depleting/modifying oxidants, Cap1 oxidation, nuclear accumulation, phosphorylation, and Cap1-dependent gene expression, is mediated by a glutathione peroxidase-like enzyme, which we name Gpx3, and an orthologue of the Saccharomyces cerevisiae Yap1 binding protein, Ybp1. In addition, Ybp1 also functions to stabilise Cap1 and this novel function is conserved in S. cerevisiae. C. albicans cells lacking Cap1, Ybp1, or Gpx3, are unable to filament and thus, escape from murine macrophages after phagocytosis, and also display defective virulence in the Galleria mellonella infection model. Innovation: Ybp1 is required to promote the stability of fungal AP-1-like transcription factors, and Ybp1 and Gpx3 mediated Cap1-dependent oxidative stress responses are essential for the effective killing of macrophages by C. albicans. Conclusion: Activation of Cap1, specifically by H2O2, is a prerequisite for the subsequent filamentation and escape of this fungal pathogen from the macrophage. Antioxid. Redox Signal. 19, 2244–2260. PMID:23706023

  1. Novel aqueous dual-channel aluminum-hydrogen peroxide battery

    NASA Astrophysics Data System (ADS)

    Marsh, Catherine; Licht, Stuart

    1994-06-01

    A dual-channel aluminum hydrogen peroxide battery is introduced with an open-circuit voltage of 1.9 volts, polarization losses of 0.9 mV cm(exp 2) mA(exp -1), and power densities of 1 W/cm(exp 2). Catholyte and anolyte cell compartments are separated by an Ir/Pd modified porous nickel cathode. Separation of catholyte and anolyte chambers prevents hydrogen peroxide poisoning of the aluminum anode. The battery is expressed by aluminum oxidation and aqueous solution phase hydrogen peroxide reduction for an overall battery discharge consisting of 2Al + 3H2O2 + 2OH(-) yields 2AlO2(-) + 4H2O E = 2.3 V. The search for electrical propulsion sources which fit the requirements for electrically powered vehicles has blurred the standard characteristics associated with electrochemical storage systems. Presently, electrochemical systems comprised of mechanically rechargeable primary batteries, secondary batteries, and fuel cells are candidates for electrochemical propulsion sources. While important advances in energy and power density continue for nonaqueous and molten electrolytes, aqueous electrolyte batteries often have an advantage in simplicity, conductivity, cost effectiveness, and environmental impact. Systems coupling aluminum anodes and aqueous electrolytes have been investigated. These systems include: aluminum/silver oxide, aluminum/manganese dioxide, aluminum air, aluminum/hydrogen peroxide aqueous batteries, and the recently introduced aluminum/ferricyanide and aluminum sulfur aqueous batteries. Conventional aqueous systems such as the nickel cadmium and lead-acid batteries are characterized by their relatively low energy densities and adverse environmental impact. Other systems have substantially higher theoretical energy capacities. While aluminum-silver oxide has demonstrated the highest steady-state power density, its high cost is an impediment for widespread utilization for electric propulsion.

  2. Hydrogen peroxide propulsion for smaller satellites (SSC98-VIII-1)

    SciTech Connect

    Whitehead, J C

    1998-07-13

    As satellite designs shrink, providing maneuvering and control capability falls outside the realm of available propulsion technology. While cold gas has been used on the smallest satellites, hydrogen peroxide propellant is suggested as the next step in performance and cost before hydrazine. Minimal toxicity and a small scale enable benchtop propellant preparation and development testing. Progress toward low-cost thrusters and self-pressurizing tank systems is described.

  3. SONEX-Hydrogen Peroxide, Methylhydroperoxide and Formaldehyde Measurements

    NASA Technical Reports Server (NTRS)

    Heikes, Brian

    1999-01-01

    We measured gas phase H2O2, CH3OOH, and CH2O on board the NASA DC-8 during the SONEX field mission, presented preliminary results at three scientific meetings, participated in two data workshops and contributed to joint publications of final results. The observations of peroxides and formaldehyde were instrumental in assessing odd-hydrogen radical chemistry, ozone chemistry, and in tracing meteorological transport paths.

  4. Ultraviolet absorption spectrum of hydrogen peroxide vapor. [for atmospheric abundances

    NASA Technical Reports Server (NTRS)

    Molina, L. T.; Schinke, S. D.; Molina, M. J.

    1977-01-01

    The ultraviolet absorption cross sections of hydrogen peroxide vapor have been determined over the wavelength range 210 to 350 nm at 296 K. At the longer wavelengths, the gas phase absorptivities are significantly larger than the corresponding values in condensed phase. The atmospheric H2O2 photodissociation rate for overhead sun at the earth's surface is estimated to be about 1.3 x 10 to the -5th/sec.

  5. Ultrasonic degradation of Rhodamine B in the presence of hydrogen peroxide and some metal oxide.

    PubMed

    Mehrdad, Abbas; Hashemzadeh, Robab

    2010-01-01

    In this research, degradation of Rodamine B in the presence of (hydrogen peroxide), (hydrogen peroxide+ultrasound), (hydrogen peroxide+aluminum oxide), (hydrogen peroxide+aluminum oxide+ultrasound with different ultrasound power), (hydrogen peroxide+iron oxide) and (hydrogen peroxide+iron oxide+ultrasound with different ultrasound power) were investigated at 25 degrees C. The apparent rate constants for the examined systems were calculated by pseudo-first-order kinetics. The results indicate that the rate of degradation was accelerated by ultrasound. The rate of degradation was increased by increasing power ultrasound. The efficiency of the (hydrogen peroxide+iron oxide+ultrasound) system for degradation of Rodamine B was higher than the others examined.

  6. Microsolvation of methyl hydrogen peroxide: Ab initio quantum chemical approach

    NASA Astrophysics Data System (ADS)

    Kulkarni, Anant D.; Rai, Dhurba; Bartolotti, Libero J.; Pathak, Rajeev K.

    2009-08-01

    Methyl hydrogen peroxide (MHP), one of the simplest organic hydroperoxides, is a strong oxidant, with enhanced activity in aqueous ambience. The present study investigates, at the molecular level, the role of hydrogen bonding that is conducive to cluster formation of MHP with water molecules from its peroxide end, with the methyl group remaining hydrophobic for up to five water molecules. Ab initio quantum chemical computations on MHP⋯(H2O)n, [n =1-5] are performed at second order Møller-Plesset (MP2) perturbation theory employing the basis sets 6-31G(d,p) and 6-311++G(2d,2p) to study the cluster formation of MHP with water molecules from its peroxide end and hydrophobic hydration due to the methyl group. Successive addition of water molecules alters the hydrogen bonding pattern, which leads to changes in overall cluster geometry and in turn to IR vibrational frequency shifts. Molecular co-operativity in these clusters is gauged directly through a detailed many-body interaction energy analysis. Molecular electrostatic potential maps are shown to have a bearing on predicting further growth of these clusters, which is duly corroborated through sample calculations for MHP⋯(H2O)8. Further, a continuum solvation model calculation for energetically stable clusters suggests that this study should serve as a precursor for pathways to aqueous solvation of MHP.

  7. A reaction-diffusion model of cytosolic hydrogen peroxide.

    PubMed

    Lim, Joseph B; Langford, Troy F; Huang, Beijing K; Deen, William M; Sikes, Hadley D

    2016-01-01

    As a signaling molecule in mammalian cells, hydrogen peroxide (H2O2) determines the thiol/disulfide oxidation state of several key proteins in the cytosol. Localization is a key concept in redox signaling; the concentrations of signaling molecules within the cell are expected to vary in time and in space in manner that is essential for function. However, as a simplification, all theoretical studies of intracellular hydrogen peroxide and many experimental studies to date have treated the cytosol as a well-mixed compartment. In this work, we incorporate our previously reported reduced kinetic model of the network of reactions that metabolize hydrogen peroxide in the cytosol into a model that explicitly treats diffusion along with reaction. We modeled a bolus addition experiment, solved the model analytically, and used the resulting equations to quantify the spatiotemporal variations in intracellular H2O2 that result from this kind of perturbation to the extracellular H2O2 concentration. We predict that micromolar bolus additions of H2O2 to suspensions of HeLa cells (0.8 × 10(9)cells/l) result in increases in the intracellular concentration that are localized near the membrane. These findings challenge the assumption that intracellular concentrations of H2O2 are increased uniformly throughout the cell during bolus addition experiments and provide a theoretical basis for differing phenotypic responses of cells to intracellular versus extracellular perturbations to H2O2 levels.

  8. Improving the hydrogen peroxide bleaching efficiency of aspen chemithermomechanical pulp by using chitosan.

    PubMed

    Li, Zongquan; Dou, Hongyan; Fu, Yingjuan; Qin, Menghua

    2015-11-01

    The presence of transition metals during the hydrogen peroxide bleaching of pulp results in the decomposition of hydrogen peroxide, which decreases the bleaching efficiency. In this study, chitosans were used as peroxide stabilizer in the alkaline hydrogen peroxide bleaching of aspen chemithermomechanical pulp (CTMP). The results showed that the brightness of the bleached CTMP increased 1.5% ISO by addition of 0.1% chitosan with 95% degree of deacetylation during peroxide bleaching. Transition metals in the form of ions or metal colloid particles, such as iron, copper and manganese, could be adsorbed by chitosans. Chitosans could inhibit the decomposition of hydrogen peroxide catalyzed by different transition metals under alkaline conditions. The ability of chitosans to inhibit peroxide decomposition depended on the type of transition metals, chitosan concentration and degree of deacetylation applied. The addition of chitosan slightly reduced the concentration of the hydroxyl radical formed during the hydrogen peroxide bleaching of aspen CTMP.

  9. Localisation of hydrogen peroxide accumulation during Solanum tuberosum cv. Rywal hypersensitive response to Potato virus Y.

    PubMed

    Otulak, Katarzyna; Garbaczewska, Grazyna

    2010-06-01

    The reactive oxygen species hydrogen peroxide (H(2)O(2)) was detected cytochemically in Solanum tuberosum cv. Rywal tissues as a hypersensitive response (HR) 24 and 48 h after a Potato virus Y (PVY) infection. Hydrogen peroxide was detected in vivo by its reaction with 3.3-diaminobenzidine, producing a reddish-brown staining in contact with H(2)O(2). Hydrogen peroxide was detected in the necrotic area of the epidermal and mesophyll cells 24 and 48 h after the PVY infection. Highly localised accumulations of H(2)O(2) were found within xylem tracheary elements, and this was much more intensive than in non-infected leaves. Hydrogen peroxide was detected cytochemically in HR also by its reaction with cerium chloride, producing electron-dense deposits of cerium perhydroxides. Inoculation with PVY(NTN) and also PVY(N) Wi induced a rapid hypersensitive response during which highly localised accumulations of H(2)O(2) was detected in plant cell walls. The most intensive accumulation was present in the bordering cell walls of necrotic mesophyll cells and the adjacent non-necrotic mesophyll cells. Intensive electron-dense deposits of cerium perhydroxide were found along ER cistrenae and chloroplast envelopes connected with PVY particles. The precipitates of hydrogen peroxide were detected in the nuclear envelope and along tracheary elements, especially when virus particles were present inside. The intensive accumulation of H(2)O(2) at the early stages of potato-PVY interaction is consistent with its role as an antimicrobial agent and for this reason it has been regarded as a signalling molecule.

  10. Electric Response of Hydrogen Peroxide-doped Water Ices: an Analog Study for Positive Hole Currents in Rocks

    NASA Astrophysics Data System (ADS)

    Stockburger, C. C.; Keller, C. T.; Gray, A.; Sornette, J.; Udom, A.; Cruikshank, D. P.; Freund, F.

    2013-12-01

    Hydrogen peroxide-doped water ices can be viewed an analog system to igneous and high-grade metamorphic rocks, which invariably contain peroxy defects, typically Si-OO-Si, and generate positive hole charge carriers when subjected to stress. By preparing pure water ice and hydrogen peroxide-doped water ices, freezing them to -80°C, allows us to control the concentration of peroxy defects (here hydrogen peroxide molecules) and study the electrical response, when the ices are subjected to stress. Blocks of pure water ice and hydrogen peroxide-doped water ices, -80°C, were prepared. Two methods to activate peroxy bonds were used: (i) stressing one end of rectangular blocks in a hydraulic press, (ii) subjecting one part of a 2-chamber plastic tray to intense ultrasound to create a gradient of activated charge carriers. In the hydraulic press experiments the pure water ice samples produced vanishingly small currents except for occasional transients, mostly negative, during fracturing of the ice. By contrast, hydrogen peroxide-doped water ices led to significant currents, consistently positive, flowing down the stress gradients. Using ultrasound as an activation method avoids fracturing. Therefore the results are much 'cleaner', not contaminated by hard-to-control fracture-induced currents. The positive sign of the currents suggests defect electrons, generated by the break-up of peroxy bonds of hydrogen peroxide molecules embedded in the ice structure, analogous to positive hole charge carriers that are stress-activated in rocks.

  11. Lichen metabolites modulate hydrogen peroxide and nitric oxide in mouse macrophages.

    PubMed

    Carlos, Iracilda Z; Quilles, Marcela B; Carli, Camila B A; Maia, Danielle C G; Benzatti, Fernanda P; Lopes, Thiago I B; Gianini, Aline S; Brum, Rosenei L; Vilegas, Wagner; dos Santos, Lourdes C; Honda, Neli K

    2009-01-01

    The activities of perlatolic acid (1), atranorin (2), and lecanoric acid (3) and their derivatives, such as orsellinates and beta-methyl orsellinates obtained by alcoholysis, were assessed for stimulation of the release of hydrogen peroxide and nitric oxide in cultures of peritoneal macrophage cells from mice. The hydrogen peroxide production was estimated by oxidation of phenol red, while the Griess reagent was used to determine the nitric oxide production. 1 and 4-methoxy-ethyl orsellinate (XVII) were the compounds that induced the greatest release of H2O2, whereas n-pentyl orsellinate (IV), iso-propyl orsellinate (V), sec-butyl orsellinate (VI), and XVII induced a small release of NO. These results indicate that lichen products and their derivatives have potential immune-modulating activities. PMID:19957434

  12. Lipid peroxidation induced by shockwave lithotripsy.

    PubMed

    Cohen, T D; Durrani, A F; Brown, S A; Ferraro, R; Preminger, G M

    1998-06-01

    To determine the relation between high-energy shockwaves (HESW) and the presence of lipid peroxidation produces, juvenile pigs were subjected to shockwave lithotripsy (SWL). After lithotripsy, both treated and control kidneys were analyzed, along with urine samples collected before, during, and after SWL. Thiobarbituric acid-reactive substance (TBARS) and lipid-conjugated diene (CD) concentrations, used as markers for membrane lipid peroxidation, were determined in the kidney and urine samples. Significantly increased mean TBARS concentrations (146%) were associated with homogenates of lithotripsy-treated kidneys, 77.8 +/- 14.4 (SD) mmol/g v the controls, 31.4 +/- 14.9 mmol/g. Lithotripsy induction of lipid peroxidation products in the cortex, the gross damage site, and the respective medulla were also examined. In HESW-treated cortex samples, increased TBARS concentrations were seen--75.0 +/- 21.3 mmol/g--compared with untreated controls-- 45.2+/- 5.6 mmol/g--while increased CD concentrations (168%) were observed in the medulla of HESW-treated samples. No significant differences were observed in TBARS or CD concentrations in urine samples from control or treated kidneys, yet specific lipid hydroperperoxides were detected in the urine of HESW-treated kidneys. We conclude that HESW lithotripsy of swine kidneys is associated with increased lipid peroxidation products that may cause further cellular damage. Lipid peroxidation induced by SWL may be one of several mechanisms that lead to other potential bioeffects. Finally, analysis of specific lipid hydroperoxides in the urine of HESW-treated kidneys may serve as a noninvasive marker of renal injury after clinical SWL.

  13. Abscisic acid and hydrogen peroxide induce modification of plasma membrane H(+)-ATPase from Cucumis sativus L. roots under heat shock.

    PubMed

    Janicka-Russak, Małgorzata; Kabała, Katarzyna

    2012-11-01

    We examined the effect of heat shock (HS), for 2 h at 48°C, on plasma membrane H(+)-ATPase (PM-H(+)-ATPase) measured as the hydrolytic and H(+)-pumping activity. Some of the plants were transferred after 2 h HS to control temperature for another 24 h, as post-stressed (PS) plants. A significant increase of PM-H(+)-ATPase in plants subjected to HS was observed. The stimulation of PM-H(+)-ATPase was higher in PS plants. Estimation of transcript levels of cucumber PM-H(+)-ATPase in roots indicated that the action of HS affected gene expression levels. Transcript levels of two isoforms, CsHA4 and CsHA8, in PS plants were elevated. The expression of PM-H(+)-ATPase genes was not affected in plants treated for 2 h with HS. HS elevated the endogenous level of abscisic acid (ABA) both in plants treated for 2 h with HS and in PS plants. Moreover, in PS plants, a distinctly higher level of H(2)O(2) was observed. It was also demonstrated that transcript levels of PM-H(+)-ATPase were elevated in cucumber roots after 24-h treatment of plants with ABA or H(2)O(2). Both of these compounds seem to play an important role in increasing ATPase activity during heat stress, because the use of the inhibitors tungstate and DPI restrained stimulation of PM-H(+)-ATPase activity by heat. Moreover, protein blot analysis with an antibody against phosphothreonine and 14-3-3 protein indicated that increased activity of PM-H(+)-ATPase under HS resulted from phosphorylation of the enzyme. Taken together, the data presented here suggest that, under post-heat stress conditions, abscisic acid and hydrogen peroxide are involved in PM-ATPase modification, through stimulation of gene expression of that PM proton pump. Moreover, heat treatment of cucumber plants results in increased phosphorylation of PM-ATPase and thus fast post-translational modification, leading to activation of the enzyme protein.

  14. Kinetic study of the reactions between chloramine disinfectants and hydrogen peroxide: temperature dependence and reaction mechanism.

    PubMed

    McKay, Garrett; Sjelin, Brittney; Chagnon, Matthew; Ishida, Kenneth P; Mezyk, Stephen P

    2013-09-01

    The temperature-dependent kinetics for the reaction between hydrogen peroxide and chloramine water disinfectants (NH2Cl, NHCl2, and NCl3) have been determined using stopped flow-UV/Vis spectrophotometry. Rate constants for the mono- and dichloramine-peroxide reaction were on the order of 10(-2)M(-1)s(-1) and 10(-5)M(-1)s(-1), respectively. The reaction of trichloramine with peroxide was negligibly slow compared to its thermal and photolytically-induced decomposition. Arrhenius expressions of ln(kH2O2-NH2Cl)=(17.3±1.5)-(51500±3700)/RT and ln(kH2O2-NHCl2)=(18.2±1.9)-(75800±5100)/RT were obtained for the mono- and dichloramine peroxide reaction over the temperature ranges 11.4-37.9 and 35.0-55.0°C, respectively. Both monochloramine and hydrogen peroxide were first-order in the rate-limiting kinetic step and concomitant measurements made using a chloride ion selective electrode showed that the chloride was produced quantitatively. These data will aid water utilities in predicting chloramine concentrations (and thus disinfection potential) throughout the water distribution system.

  15. Pentachlorophenol (PCP) degradation using heme and hydrogen peroxide

    SciTech Connect

    Chen, S.T.

    1996-11-01

    Investigations of pentachlorophenol (PCP) degradation using both biotic and abiotic methods have been extensively studied. Due to the hydrophobic nature of PCP and its toxicity, the performance of the biotic treatments varies from site to site and is not satisfactory in most cases. An abiotic method for oxidative PCP degradation in soil under unsaturated conditions and a neutral pH was found. Hydrogen peroxide was used as an oxidant and heme as a catalyst. A mechanism was proposed to describe the possible reaction of heme and peroxide at the presence of PCP. In order to ensure that heme and peroxide are the most important factors during the reaction, two screening tests were run. In order to find the best conditions of PCP degradation using heme and peroxide, a statistical technique, so-called response surface methodology (RSM), was employed and the best conditions for PCP degradation in soil were determined. In order to examine the rate and extent of PCP degradation, kinetic studies were conducted and the results showed that about 70% of PCP was degraded within the first two hours and up to 80% of PCP was degraded within one day. Up to 17% of the PCP was mineralized to carbon dioxide as well. A scaled-up experiment was also studied to confirm the results in the laboratory. The result of the scaled-up experiment showed not much difference between the laboratory and the scaled-up experiments.

  16. Improved sensing response of photo activated ZnO thin film for hydrogen peroxide detection.

    PubMed

    Parthasarathy, S; Nandhini, V; Jeyaprakash, B G

    2016-11-15

    The nanostructured ZnO thin films were deposited using spray pyrolysis technique. Formation of polycrystalinity with hexagonal wurtzite structure was observed from the structural study. Highly dense spherical shaped nanoparticles with fine crystallites were observed from the surface morphological studies. The light induced hydrogen peroxide vapour sensing was done using chemi-resistive method and its effect on the sensing response was studied and reported.

  17. Improved sensing response of photo activated ZnO thin film for hydrogen peroxide detection.

    PubMed

    Parthasarathy, S; Nandhini, V; Jeyaprakash, B G

    2016-11-15

    The nanostructured ZnO thin films were deposited using spray pyrolysis technique. Formation of polycrystalinity with hexagonal wurtzite structure was observed from the structural study. Highly dense spherical shaped nanoparticles with fine crystallites were observed from the surface morphological studies. The light induced hydrogen peroxide vapour sensing was done using chemi-resistive method and its effect on the sensing response was studied and reported. PMID:27491004

  18. Durability of bleaching results achieved with 15% carbamide peroxide and 38% hydrogen peroxide in vitro.

    PubMed

    Knösel, Michael; Reus, Monika; Rosenberger, Albert; Attin, Thomas; Ziebolz, Dirk

    2011-01-01

    The aim of this study was to assess the durability of bleaching results achieved with (1) 15% carbamide peroxide home bleaching and (2) 38% hydrogen peroxide in-office bleaching. A total of 231 extracted anterior teeth were randomly divided into three groups (n = 77 in each group) with comparable mean baseline L*-values (68.24 ± 0.8): a non-bleached control group A, a 15% carbamide peroxide group B (5 bleaching intervals of 8 hours), and a 38% hydrogen peroxide group C (3 intervals of 15 minutes). Durability of bleaching was assessed by comparing CIE-L*a*b* data after intervals of 2, 4, 12, and 26 weeks from baseline. Both bleaching regimes initially produced a highly significant increase in lightness parameter L*, with no significant difference between the respective bleaching regimes (B: 68.23 / 72.48; C: 68.32 / 73.25). Six months after starting the trial, L*-values for group B yielded no significant differences compared to baseline (69.55), whereas L*-values for group C were still significantly raised (69.91), despite a highly significant decrease when compared to initial bleaching results. In both treatment groups, there was a lasting response to bleaching in terms of CIE-a* and -b* value decreases. Results for both home- and in-practice regimes were found to be similar for about 12 weeks. However, in-office results were longer lasting, despite the shorter treatment intervals. Summarized bleaching effects, in terms of delta E values, revealed no significant differences between treatment groups and the control group after 6 months, indicating an abatement of the bleaching results achieved.

  19. Hydrogen peroxide in the western Mediterranean Sea: a tracer for vertical advection

    NASA Astrophysics Data System (ADS)

    Johnson, Kenneth S.; Willason, Stewart W.; Wiesenburg, Denis A.; Lohrenz, Steven E.; Arnone, Robert A.

    1989-02-01

    Hydrogen peroxide, micronutrients, chlorophyll, primary production and light were measured at a series of stations in the western Mediterranean Sea. Hydrogen peroxide concentrations greater than 100 nmol 1 -1 were found in this region. There was a significant relationship between hydrogen peroxide and primary production rates near the surface where the light intensity was high. This link between hydrogen peroxide and biological activity may have resulted from photochemically reactive organic compounds that were excreted during photosynthesis or from the direct biological production of hydrogen peroxide. Elevated concentrations were not found in the deep chlorophyll maximum however, which indicates that high light intensities are necessary for biogenic hydrogen peroxide production in this area. Hydrogen peroxide concentrations decreased much more slowly with depth than did light. The decoupling of light and hydrogen peroxide must have been due to a combination of a slow decay rate and rapid vertical transport. However, simple calculations indicate that eddy diffusion alone could not have transported enough hydrogen peroxide to produce the effects that were seen. Large anomalies in the concentration profiles that were detected in frontal regions indicate that hydrogen peroxide can be a useful tracer of vertical transport in the upper ocean. The size of the anomalies appears to be coupled to the salinity gradient across the front, which drives the frontal circulation.

  20. Photochemical formation of hydrogen peroxide in surface and ground waters exposed to sunlight

    SciTech Connect

    Cooper, W.J.; Zika, R.G.

    1983-05-13

    A rapid increase in the concentration of hydrogen peroxide was observed when samples of natural surface and ground water from various locations in the United States were exposed to sunlight. The hydrogen peroxide is photochemically generated from organic constitutents present in the water; humic materials are believed to be the primary agent producing the peroxide. Studies with superoxide dismutase suggest that the superoxide anion is the precursor of the peroxide.

  1. Understanding the mechanism of DNA deactivation in ion therapy of cancer cells: hydrogen peroxide action*

    NASA Astrophysics Data System (ADS)

    Piatnytskyi, Dmytro V.; Zdorevskyi, Oleksiy O.; Perepelytsya, Sergiy M.; Volkov, Sergey N.

    2015-11-01

    Changes in the medium of biological cells under ion beam irradiation has been considered as a possible cause of cell function disruption in the living body. The interaction of hydrogen peroxide, a long-lived molecular product of water radiolysis, with active sites of DNA macromolecule was studied, and the formation of stable DNA-peroxide complexes was considered. The phosphate groups of the macromolecule backbone were picked out among the atomic groups of DNA double helix as a probable target for interaction with hydrogen peroxide molecules. Complexes consisting of combinations including: the DNA phosphate group, H2O2 and H2O molecules, and Na+ counterion, were considered. The counterions have been taken into consideration insofar as under the natural conditions they neutralise DNA sugar-phosphate backbone. The energy of the complexes have been determined by considering the electrostatic and the Van der Waals interactions within the framework of atom-atom potential functions. As a result, the stability of various configurations of molecular complexes was estimated. It was shown that DNA phosphate groups and counterions can form stable complexes with hydrogen peroxide molecules, which are as stable as the complexes with water molecules. It has been demonstrated that the formation of stable complexes of H2O2-Na+-PO4- may be detected experimentally by observing specific vibrations in the low-frequency Raman spectra. The interaction of H2O2 molecule with phosphate group of the double helix backbone can disrupt DNA biological function and induce the deactivation of the cell genetic apparatus. Thus, the production of hydrogen peroxide molecules in the nucleus of living cells can be considered as an additional mechanism by which high-energy ion beams destroy tumour cells during ion beam therapy. Contribution to the Topical Issue "COST Action Nano-IBCT: Nano-scale Processes Behind Ion-Beam Cancer Therapy", edited by Andrey Solov'yov, Nigel Mason, Gustavo García, Eugene

  2. Vapor hydrogen peroxide as alternative to dry heat microbial reduction

    NASA Astrophysics Data System (ADS)

    Chung, S.; Kern, R.; Koukol, R.; Barengoltz, J.; Cash, H.

    2008-09-01

    The Jet Propulsion Laboratory (JPL), in conjunction with the NASA Planetary Protection Officer, has selected vapor phase hydrogen peroxide (VHP) sterilization process for continued development as a NASA approved sterilization technique for spacecraft subsystems and systems. The goal was to include this technique, with an appropriate specification, in NASA Procedural Requirements 8020.12 as a low-temperature complementary technique to the dry heat sterilization process. The VHP process is widely used by the medical industry to sterilize surgical instruments and biomedical devices, but high doses of VHP may degrade the performance of flight hardware, or compromise material compatibility. The goal for this study was to determine the minimum VHP process conditions for planetary protection acceptable microbial reduction levels. Experiments were conducted by the STERIS Corporation, under contract to JPL, to evaluate the effectiveness of vapor hydrogen peroxide for the inactivation of the standard spore challenge, Geobacillus stearothermophilus. VHP process parameters were determined that provide significant reductions in spore viability while allowing survival of sufficient spores for statistically significant enumeration. In addition to the obvious process parameters of interest: hydrogen peroxide concentration, number of injection cycles, and exposure duration, the investigation also considered the possible effect on lethality of environmental parameters: temperature, absolute humidity, and material substrate. This study delineated a range of test sterilizer process conditions: VHP concentration, process duration, a process temperature range for which the worst case D-value may be imposed, a process humidity range for which the worst case D-value may be imposed, and the dependence on selected spacecraft material substrates. The derivation of D-values from the lethality data permitted conservative planetary protection recommendations.

  3. Hydrogen peroxide administered into the rat spinal cord at the level elevated by contusion spinal cord injury oxidizes proteins, DNA and membrane phospholipids, and induces cell death: attenuation by a metalloporphyrin.

    PubMed

    Liu, D; Bao, F

    2015-01-29

    We previously demonstrated that hydrogen peroxide concentration ([H2O2]) significantly increases after spinal cord injury (SCI). The present study explored (1) whether SCI-elevated [H2O2] is sufficient to induce oxidation and cell death, (2) if apoptosis is a pathway of H2O2-induced cell death, and (3) whether H2O2-induced oxidation and cell death could be reversed by treatment with the catalytic antioxidant Mn (III) tetrakis (4-benzoic acid) porphyrin (MnTBAP). H2O2 was perfused through a microcannula into the uninjured rat spinal cord to mimic the conditions induced by SCI. Protein and DNA oxidation, membrane phospholipids peroxidation (MLP), cell death and apoptosis were characterized by histochemical and immunohistochemical staining with antibodies against markers of oxidation and apoptosis. Stained cells were quantified in sections of H2O2-, or artificial cerebrospinal fluid (ACSF)-exposed with vehicle-, or MnTBAP-treated groups. Compared with ACSF-exposed animals, SCI-elevated [H2O2] significantly increased intracellular protein and DNA oxidation by threefold and MLP by eightfold in neurons, respectively. H2O2-elevated extracellular malondialdehyde was measured by microdialysis sampling. We demonstrated that SCI-elevated [H2O2] significantly increased extracellular malondialdehyde above pre-injury levels. H2O2 also significantly increased cell loss and the numbers of terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate-(dUTP)-biotin nick end labeling (TUNEL)-positive and active caspase-3-positive neurons by 2.3-, 2.8-, and 5.6-fold compared to ACSF controls, respectively. Our results directly and unequivocally demonstrate that SCI-elevated [H2O2] contributes to post-SCI MLP, protein, and DNA oxidation to induce cell death. Therefore, we conclude that (1) the role of H2O2 in secondary SCI is pro-oxidation and pro-cell death, (2) apoptosis is a pathway for SCI-elevated [H2O2] to induce cell death, (3) caspase activation is a mechanism

  4. Hydrogen peroxide as an effective disinfectant for Pasteurella multocida.

    PubMed

    Jung, In-Soo; Kim, Hyun-Jung; Jung, Won-Yong; Kim, Chan-Wha

    2014-07-01

    Pasteurella multocida (P. multocida) infections vary widely, from local infections resulting from animal bites and scratches to general infections. As of yet, no vaccine against P. multocida has been developed, and the most effective way to prevent pathogenic transmission is to clean the host environment using disinfectants. In this study, we identified which disinfectants most effectively inhibited environmental isolates of P. multocida. Three readily available disinfectants were compared: 3% hydrogen peroxide (HP), 70% isopropyl alcohol, and synthetic phenol. In suspension tests and zone inhibition tests, 3% HP was the most promising disinfectant against P. multocida.

  5. Hydrogen peroxide in inflammation: messenger, guide, and assassin.

    PubMed

    Wittmann, C; Chockley, P; Singh, S K; Pase, L; Lieschke, G J; Grabher, C

    2012-01-01

    Starting as a model for developmental genetics, embryology, and organogenesis, the zebrafish has become increasingly popular as a model organism for numerous areas of biology and biomedicine over the last decades. Within haematology, this includes studies on blood cell development and function and the intricate regulatory mechanisms within vertebrate immunity. Here, we review recent studies on the immediate mechanisms mounting an inflammatory response by in vivo analyses using the zebrafish. These recently revealed novel roles of the reactive oxygen species hydrogen peroxide that have changed our view on the initiation of a granulocytic inflammatory response. PMID:22737171

  6. Detection of hydrogen peroxide by lactoperoxidase-mediated dityrosine formation.

    PubMed

    Donkó, Agnes; Orient, Anna; Szabó, Pál T; Németh, Gábor; Vántus, Tibor; Kéri, György; Orfi, László; Hunyady, László; Buday, László; Geiszt, Miklós

    2009-05-01

    The aim of this work was to study the dityrosine-forming activity of lactoperoxidase (LPO) and its potential application for measuring hydrogen peroxide (H2O2). It was observed that LPO was able to form dityrosine at low H2O2 concentrations. Since dityrosine concentration could be measured in a simple fluorimetric reaction, this activity of the enzyme was utilized for the measurement of H2O2 production in different systems. These experiments successfully measured the activity of NADPH oxidase 4 (Nox4) by this method. It was concluded that LPO-mediated dityrosine formation offers a simple way for H2O2 measurement.

  7. Hydrogen peroxide-based propulsion and power systems.

    SciTech Connect

    Melof, Brian Matthew; Keese, David L.; Ingram, Brian V.; Grubelich, Mark Charles; Ruffner, Judith Alison; Escapule, William Rusty

    2004-04-01

    Less toxic, storable, hypergolic propellants are desired to replace nitrogen tetroxide (NTO) and hydrazine in certain applications. Hydrogen peroxide is a very attractive replacement oxidizer, but finding acceptable replacement fuels is more challenging. The focus of this investigation is to find fuels that have short hypergolic ignition delays, high specific impulse, and desirable storage properties. The resulting hypergolic fuel/oxidizer combination would be highly desirable for virtually any high energy-density applications such as small but powerful gas generating systems, attitude control motors, or main propulsion. These systems would be implemented on platforms ranging from guided bombs to replacement of environmentally unfriendly existing systems to manned space vehicles.

  8. The effect of hydrogen peroxide on polishing removal rate in CMP with various abrasives

    NASA Astrophysics Data System (ADS)

    Manivannan, R.; Ramanathan, S.

    2009-01-01

    The effect of hydrogen peroxide in chemical mechanical planarization slurries for shallow trench isolation was investigated. The various abrasives used in this study were ceria, silica, alumina, zirconia, titania, silicon carbide, and silicon nitride. Hydrogen peroxide suppresses the polishing of silicon dioxide and silicon nitride surfaces by ceria abrasives. The polishing performances of other abrasives were either unaffected or enhanced slightly with the addition of hydrogen peroxide. The ceria abrasives were treated with hydrogen peroxide, and the polishing of the work surfaces with the treated abrasive shows that the inhibiting action of hydrogen peroxide is reversible. It was found that the effect of hydrogen peroxide as an additive is a strong function of the nature of the abrasive particle.

  9. APPARATUS AND METHOD FOR TREATING POLLUTANTS IN A GAS USING HYDROGEN PEROXIDE AND UV LIGHT

    NASA Technical Reports Server (NTRS)

    Cooper, Charles David (Inventor); Clauseu, christian Anthony (Inventor)

    2005-01-01

    An apparatus for treating pollutants in a gas may include a source of hydrogen peroxide, and a treatment injector for creating and injecting dissociated hydrogen peroxide into the flow of gas. The treatment injector may further include an injector housing having an inlet, an outlet, and a hollow interior extending there between. The inlet may be connected in fluid communication with the source of hydrogen peroxide so that hydrogen peroxide flows through the hollow interior and toward the outlet. At least one ultraviolet (UV) lamp may be positioned within the hollow interior of the injector housing. The at least one UV lamp may dissociate the hydrogen peroxide flowing through the tube. The dissociated hydrogen peroxide may be injected into the flow of gas from the outlet for treating pollutants, such as nitrogen oxides.

  10. Apparatus and method for treating pollutants in a gas using hydrogen peroxide and UV light

    NASA Technical Reports Server (NTRS)

    Cooper, Charles David (Inventor); Clausen, Christian Anthony (Inventor)

    2005-01-01

    An apparatus for treating pollutants in a gas may include a source of hydrogen peroxide, and a treatment injector for creating and injecting dissociated hydrogen peroxide into the flow of gas. The treatment injector may further include an injector housing having an inlet, an outlet, and a hollow interior extending therebetween. The inlet may be connected in fluid communication with the source of hydrogen peroxide so that hydrogen peroxide flows through the hollow interior and toward the outlet. At least one ultraviolet (UV) lamp may be positioned within the hollow interior of the injector housing. The at least one UV lamp may dissociate the hydrogen peroxide flowing through the tube. The dissociated hydrogen peroxide may be injected into the flow of gas from the outlet for treating pollutants, such as nitrogen oxides.

  11. Hydrogenation of liquid natural rubber via diimide reduction in hydrazine hydrate/hydrogen peroxide system

    SciTech Connect

    Yusof, Muhammad Jefri Mohd; Jamaluddin, Naharullah; Abdullah, Ibrahim; Yusoff, Siti Fairus M.

    2015-09-25

    Liquid natural rubber (LNR) with molecular weight of lower than 10{sup 5} and shorter polymeric chain than natural rubber was prepared. LNR was then hydrogenated via diimide reduction by oxidation of hydrazine hydrate with hydrogen peroxide. The unsaturated units of the rubber were converted into saturated hydrocarbon to strengthen the backbone of the polymer so it was able to resist thermal degradation. The results indicated that hydrogenation degree of the product (HLNR) could be extended to 91.2% conversion under appropriate conditions. The hydrogenated LNR (HLNR) was characterized using Fourier-Transform Infrared (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopy. The physical characteristics of HLNR were analyzed with Termogravimetric Analysis (TGA)

  12. Hydrogenation of liquid natural rubber via diimide reduction in hydrazine hydrate/hydrogen peroxide system

    NASA Astrophysics Data System (ADS)

    Yusof, Muhammad Jefri Mohd; Jamaluddin, Naharullah; Abdullah, Ibrahim; Yusoff, Siti Fairus M.

    2015-09-01

    Liquid natural rubber (LNR) with molecular weight of lower than 105 and shorter polymeric chain than natural rubber was prepared. LNR was then hydrogenated via diimide reduction by oxidation of hydrazine hydrate with hydrogen peroxide. The unsaturated units of the rubber were converted into saturated hydrocarbon to strengthen the backbone of the polymer so it was able to resist thermal degradation. The results indicated that hydrogenation degree of the product (HLNR) could be extended to 91.2% conversion under appropriate conditions. The hydrogenated LNR (HLNR) was characterized using Fourier-Transform Infrared (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopy. The physical characteristics of HLNR were analyzed with Termogravimetric Analysis (TGA).

  13. Differential regulation of epidermal growth factor receptor by hydrogen peroxide and flagellin in cultured lung alveolar epithelial cells.

    PubMed

    Nishi, Hiroyuki; Maeda, Noriko; Izumi, Shunsuke; Higa-Nakamine, Sayomi; Toku, Seikichi; Kakinohana, Manabu; Sugahara, Kazuhiro; Yamamoto, Hideyuki

    2015-02-01

    In previous studies, we found that stimulation of Toll-like receptor 5 (TLR5) by flagellin induced the activation of mitogen-activated protein kinase (MAPK)-activated protein kinase-2 (MAPKAPK-2) through activation of the p38 MAPK pathway in cultured alveolar epithelial A549 cells. Our studies strongly suggested that MAPKAPK-2 phosphorylated epidermal growth factor receptor (EGFR) at Ser1047. It has been reported that phosphorylation of Ser1047 after treatment with tumor necrosis factor α (TNFα) induced the internalization of EGFR. In the present study, we first found that treatment of A549 cells with hydrogen peroxide induced the activation of MAPKAPK-2 and phosphorylation of EGFR at Ser1047 within 30 min. This was different from flagellin treatment because hydrogen peroxide treatment induced the phosphorylation of EGFR at Tyr1173 as well as Ser1047, indicating the activation of EGFR. We also found that KN93, an inhibitor of CaM kinase II, inhibited the hydrogen peroxide-induced phosphorylation of EGFR at Ser1047 through inhibition of the activation of the p38 MAPK pathway. Furthermore, we examined the internalization of EGFR by three different methods. Flow cytometry with an antibody against the extracellular domain of EGFR and biotinylation of cell surface proteins revealed that flagellin, but not hydrogen peroxide, decreased the amount of cell-surface EGFR. In addition, activation of extracellular signal-regulated kinase by EGF treatment was reduced by flagellin pre-treatment. These results strongly suggested that hydrogen peroxide activated the p38 MAPK pathway via activation of CaM kinase II and that flagellin and hydrogen peroxide regulate the functions of EGFR by different mechanisms.

  14. Is SS-A/Ro52 a hydrogen peroxide-sensitive signaling molecule?

    PubMed

    Nobuhara, Yumiko; Kawano, Seiji; Kageyama, Goichi; Sugiyama, Daisuke; Saegusa, Jun; Kumagai, Shunichi

    2007-03-01

    SS-A/Ro52 (Ro52) protein is one of the targets of autoantibodies in Sjogren's syndrome and systemic lupus erythematosus. Ro52 structurally belongs to the RING-B-box/coiled-coil family, which appears to carry out diverse functions, but the physiological function of Ro52 remains largely unknown. Here, the authors demonstrate that hydrogen peroxide but not other oxidative stressors induced translocation of Ro52 protein from the cytoplasm to the nucleus and this phenomenon was attenuated by inhibition of MAP kinases, ERK in particular. These findings raise the possibility that SS-A/Ro52 may function as a hydrogen peroxide-selective, oxidative stress-sensitive signaling molecule that is activated via the MAP kinase pathway.

  15. Hydrogen Peroxide Accidents and Incidents: What We Can Learn From History

    NASA Technical Reports Server (NTRS)

    Greene, Ben; Baker, David L.; Frazier, Wayne

    2005-01-01

    Historical accidents and incidents involving hydrogen peroxide are reviewed and presented. These hydrogen peroxide events are associated with storage, transportation, handling, and disposal and they include exposures, fires, and explosions. Understanding the causes and effects of these accident and incident examples may aid personnel currently working with hydrogen peroxide to mitigate and perhaps avoid similar situations. Lessons learned, best practices, and regulatory compliance information related to the cited accidents and incidents are also discussed.

  16. Time-course diffusion of hydrogen peroxide using modern technologies

    NASA Astrophysics Data System (ADS)

    Florez, F. L. E.; Vollet-Filho, J. D.; Oliveira-Junior, O. B.; Bagnato, V. S.

    2009-02-01

    The concern with the hydrogen penetration towards the pulp can be observed on the literature by the great number of papers published on this topic; Those measurements often uses chemical agents to quantify the concentration of the bleaching agent that cross the enamel and dentin. The objective of this work was the quantification of oxygen free radicals by fluorescence that are located in the interface between enamel and dentin. It was used to accomplish our objectives a Ruthenium probe (FOXY R - Ocean Optics) a 405nm LED, a bovine tooth and a portable diagnostic system (Science and support LAB - LAT - IFSC/USP). The fluorescence of the probe is suppressed in presence of oxygen free radicals in function of time. The obtained results clearly shows that the hydrogen peroxide when not catalyzed should be kept in contact with the tooth for longer periods of time.

  17. Use of hydrogen peroxide as a biocide: new consideration of its mechanisms of biocidal action.

    PubMed

    Linley, Ezra; Denyer, Stephen P; McDonnell, Gerald; Simons, Claire; Maillard, Jean-Yves

    2012-07-01

    Hydrogen peroxide is extensively used as a biocide, particularly in applications where its decomposition into non-toxic by-products is important. Although increasing information on the biocidal efficacy of hydrogen peroxide is available, there is still little understanding of its biocidal mechanisms of action. This review aims to combine past and novel evidence of interactions between hydrogen peroxide and the microbial cell and its components, while reflecting on alternative applications that make use of gaseous hydrogen peroxide. It is currently believed that the Fenton reaction leading to the production of free hydroxyl radicals is the basis of hydrogen peroxide action and evidence exists for this reaction leading to oxidation of DNA, proteins and membrane lipids in vivo. Investigations of DNA oxidation suggest that the oxidizing radical is the ferryl radical formed from DNA-associated iron, not hydroxyl. Investigations of protein oxidation suggest that selective oxidation of certain proteins might occur, and that vapour-phase hydrogen peroxide is a more potent oxidizer of protein than liquid-phase hydrogen peroxide. Few studies have investigated membrane damage by hydrogen peroxide, though it is suggested that this is important for the biocidal mechanism. No studies have investigated damage to microbial cell components under conditions commonly used for sterilization. Despite extensive studies of hydrogen peroxide toxicity, the mechanism of its action as a biocide requires further investigation.

  18. Singlet oxygen generation from [bis(trifluoroacetoxy)iodo]benzene and hydrogen peroxide.

    PubMed

    Catir, Mustafa; Kilic, Hamdullah; Nardello-Rataj, Véronique; Aubry, Jean-Marie; Kazaz, Cavit

    2009-06-19

    Decomposition of hydrogen peroxide with a hypervalent iodine compound was examined. The results indicate that treatment of a hypervalent iodine compound with hydrogen peroxide produces singlet molecular oxygen ((1)O(2)). Convergent evidence for the production of singlet molecular oxygen ((1)O(2)) by decomposition of hydrogen peroxide with a hypervalent iodine compound comes from chemical trapping experiments and the specific chemiluminescence detection of (1)O(2) at 1270 nm. Substantial evidence demonstrates that hydroperoxyl radical produced from hydrogen peroxide with hypervalent iodine reacts via a tetraoxidane intermediate, decomposing to give singlet molecular oxygen. PMID:19449850

  19. Inhibitory effects of LPA1 on cell motile activities stimulated by hydrogen peroxide and 2,3-dimethoxy-1,4-naphthoquinone in fibroblast 3T3 cells.

    PubMed

    Hirane, Miku; Araki, Mutsumi; Dong, Yan; Honoki, Kanya; Fukushima, Nobuyuki; Tsujiuchi, Toshifumi

    2013-11-01

    Reactive oxygen species (ROS) are known to mediate a variety of biological responses, including cell motility. Recently, we indicated that lysophosphatidic acid (LPA) receptor-3 (LPA3) increased cell motile activity stimulated by hydrogen peroxide. In the present study, we assessed the role of LPA1 in the cell motile activity mediated by ROS in mouse fibroblast 3T3 cells. 3T3 cells were treated with hydrogen peroxide and 2,3-dimethoxy-1,4-naphthoquinone (DMNQ) at concentrations of 0.1 and 1 μM for 48 h. In cell motility assays with Cell Culture Inserts, the cell motile activities of 3T3 cells treated with hydrogen peroxide and DMNQ were significantly higher than those of untreated cells. 3T3 cells treated with hydrogen peroxide and DMNQ showed elevated expression levels of the Lpar3 gene, but not the Lpar1 and Lpar2 genes. To investigate the effects of LPA1 on the cell motile activity induced by hydrogen peroxide and DMNQ, Lpar1-overexpressing (3T3-a1) cells were generated from 3T3 cells and treated with hydrogen peroxide and DMNQ. The cell motile activities stimulated by hydrogen peroxide and DMNQ were markedly suppressed in 3T3-a1 cells. These results suggest that LPA signaling via LPA1 inhibits the cell motile activities stimulated by hydrogen peroxide and DMNQ in 3T3 cells.

  20. YS 51, 1-(beta-naphtylmethyl)-6,7-dihydroxy-1,2,3,4,-tetrahydroisoquinoline, protects endothelial cells against hydrogen peroxide-induced injury via carbon monoxide derived from heme oxygenase-1.

    PubMed

    Heo, Ja Myung; Kim, Hye Jung; Ha, Yu Mi; Park, Min Kyu; Kang, Young Jin; Lee, Young Soo; Seo, Han Geuk; Lee, Jae Heun; Yun-Choi, Hye Sook; Chang, Ki Churl

    2007-11-01

    Oxidative stress plays an important role in the pathophysiology of several vascular diseases such as atherosclerosis, and great attention has been placed on the protective role of heme oxygenase-1 (HO-1) for vasculature against oxidant-induced injury. We tested whether the protective effects of YS 51, 1-(beta-naphtyl-methyl)-6,7-dihydroxy-1,2,3,4,-tetrahydroisoquinoline, against hydrogen peroxide (H2O2)-induced cell injury is associated with HO-1 activity in bovine aortic endothelial cells (BAEC). YS 51 increased HO-1 expression and activity in concentration-dependent manners (10-100 microM) and time-dependent manners (1, 3, 6, 18 h), which were correlated well with its protective effect against H2O2-induced injury. Zinc protoporphyrin IX (ZnPP IX), a HO inhibitor, significantly inhibited the effect of YS 51 (50 microM). In contrast, [Ru(CO)3(Cl)2]2 (CORM-2, a CO releasing molecule) but not bilirubin protected against H2O2-induced injury. Oxyhemoglobin (HbO2) used as a CO scavenger significantly inhibited the protective effect of both YS 51 and CORM-2. Furthermore, both YS 51 and CORM-2 significantly reduced H2O2-induced intracellular reactive oxygen species (ROS) production; however, this was counteracted by ZnPP IX, HbO2 and deferoxamine. We found evidence for the involvement of PI3/Akt kinase and ERK1/2 pathways in HO-1 induction by YS-51. Taken together, we conclude that CO is, at least, responsible for the YS 51-mediated protective action of endothelial cells against oxidant stress via HO-1 gene induction, involving the activation of the PI3/Akt and ERK1/2 kinase pathways. Thus, YS 51 may be useful in oxidative stress-induced vascular disorders.

  1. Hydrogen peroxide generation from hydrated protein drink mixes.

    PubMed

    Boatright, William L

    2013-11-01

    Generation of oxygen radicals upon hydration of powdered protein products was examined using luminol-enhanced chemiluminescence. Among individual proteins powders examined oxidative bursts occurred almost immediately, and then rapidly declined in the 1st 5 min. Commercially available powdered protein drink mixes behaved differently, with an initial lag phase followed by a sustained increase in luminol-enhanced luminescence, lasting for an hour or beyond. The drink mix that produced the highest level of luminol-enhanced luminescence also contained 379 nM ascorbate radical when hydrated (28 nmole/g of powdered drink mix). The entire ascorbic acid content of this drink mix was oxidized to nondetectable levels (using HPLC-diode array detection) within 60 min of being hydrated. Treatment of the hydrated drink mixes with the enzyme catalase almost completely inhibited the luminol-enhanced luminescence from the hydrated drink mix demonstrating that hydrogen peroxide generated via a chemical reaction among the drink mixes' ingredients was a primary reactive oxygen species (ROS). This is the strongest oxidative capacity demonstrated in a food product as consumed (without any manipulation to increase ROS) and the 1st time that the ascrobate radical in a food product as been quantified. Generation of hydrogen peroxide in the hydrated drink mixes from metal catalyzed reactions involving oxygen and reducing equivalents from ascorbic acid is proposed.

  2. MEMS-based satellite micropropulsion via catalyzed hydrogen peroxide decomposition

    NASA Astrophysics Data System (ADS)

    Hitt, Darren L.; Zakrzwski, Charles M.; Thomas, Michael A.

    2001-12-01

    Microelectromechanical systems (MEMS) techniques offer great potential in satisfying the mission requirements for the next generation of miniaturized spacecraft being designed by NASA and Department of Defense agencies. More commonly referred to as `nanosats', these spacecraft feature masses in the range of 10-100 kg and therefore have unique propulsion requirements. The propulsion systems must be capable of providing extremely low levels of thrust and impulse while also satisfying stringent demands on size, mass, power consumption and cost. We begin with an overview of micropropulsion requirements and some current MEMS-based strategies being developed to meet these needs. The remainder of the paper focuses on the progress being made at NASA Goddard Space Flight Center toward the development of a prototype monopropellant MEMS thruster which uses the catalyzed chemical decomposition of high-concentration hydrogen peroxide as a propulsion mechanism. The products of decomposition are delivered to a microscale converging/diverging supersonic nozzle, which produces the thrust vector; the targeted thrust level is approximately 500 µN with a specific impulse of 140-180 s. Macroscale hydrogen peroxide thrusters have been used for satellite propulsion for decades; however, the implementation of traditional thruster designs on the MEMS scale has uncovered new challenges in fabrication, materials compatibility, and combustion and hydrodynamic modeling. A summary of the achievements of the project to date is given, as is a discussion of remaining challenges and future prospects.

  3. Fiber optic biosensors for hydrogen peroxide and L-lactate

    NASA Astrophysics Data System (ADS)

    Schubert, Florian; Rinneberg, Herbert H.; Wang, Fang

    1995-02-01

    An optical fiber biosensor for the selective determination of hydrogen peroxide has been developed as the base sensor for the construction of multienzyme optodes involving lactate converting enzymes for the analysis of lactic acid. The optode uses the H2O2 dependent oxidation of homovanillic acid by horseradish peroxidase (HRP) as the sensing reaction. The fluorescence of the dimeric product formed is used as the measuring signal related to the concentration of H2O2. HRP was immobilized on a membrane and combined with a bifurcated fiber optic probe. Under optimized conditions the sensor responds linearly to hydrogen peroxide between 1 micrometers ol/l and 0.12 mmol/l and exhibits a half life of 90 days. Using a lactate oxidase-HRP membrane, the sensor is suitable for lactate measurement with a linear range of 3 micrometers ol/l-0.2 mmol/l. To increase the sensitivity for lactate, lactate dehydrogenase was coimmobilized on the sensor membrane. In the presence of NADH the signal for lactate is amplified fourfold through the internal analyte recycling accomplished by the lactate-converting enzymes.

  4. MEMS-Based Satellite Micropropulsion Via Catalyzed Hydrogen Peroxide Decomposition

    NASA Technical Reports Server (NTRS)

    Hitt, Darren L.; Zakrzwski, Charles M.; Thomas, Michael A.; Bauer, Frank H. (Technical Monitor)

    2001-01-01

    Micro-electromechanical systems (MEMS) techniques offer great potential in satisfying the mission requirements for the next generation of "micro-scale" satellites being designed by NASA and Department of Defense agencies. More commonly referred to as "nanosats", these miniature satellites feature masses in the range of 10-100 kg and therefore have unique propulsion requirements. The propulsion systems must be capable of providing extremely low levels of thrust and impulse while also satisfying stringent demands on size, mass, power consumption and cost. We begin with an overview of micropropulsion requirements and some current MEMS-based strategies being developed to meet these needs. The remainder of the article focuses the progress being made at NASA Goddard Space Flight Center towards the development of a prototype monopropellant MEMS thruster which uses the catalyzed chemical decomposition of high concentration hydrogen peroxide as a propulsion mechanism. The products of decomposition are delivered to a micro-scale converging/diverging supersonic nozzle which produces the thrust vector; the targeted thrust level approximately 500 N with a specific impulse of 140-180 seconds. Macro-scale hydrogen peroxide thrusters have been used for satellite propulsion for decades; however, the implementation of traditional thruster designs on a MEMS scale has uncovered new challenges in fabrication, materials compatibility, and combustion and hydrodynamic modeling. A summary of the achievements of the project to date is given, as is a discussion of remaining challenges and future prospects.

  5. Vapor hydrogen peroxide as alternative to dry heat microbial reduction

    NASA Astrophysics Data System (ADS)

    Chung, S.; Kern, R.; Koukol, R.; Barengoltz, J.; Cash, H.

    The Jet Propulsion Laboratory in conjunction with the NASA Planetary Protection Officer has selected vapor phase hydrogen peroxide sterilization process for continued development as a NASA approved sterilization technique for spacecraft subsystems and systems The goal is to include this technique with appropriate specification in NPG8020 12C as a low temperature complementary technique to the dry heat sterilization process To meet microbial reduction requirements for all Mars in-situ life detection and sample return missions various planetary spacecraft subsystems will have to be exposed to a qualified sterilization process This process could be the elevated temperature dry heat sterilization process 115C for 40 hours which was used to sterilize the Viking lander spacecraft However with utilization of highly sophisticated electronics and sensors in modern spacecraft this process presents significant materials challenges and is thus undesirable to design engineers to achieve bioburden reduction The objective of this work is to introduce vapor hydrogen peroxide VHP as an alternative to dry heat microbial reduction to meet planetary protection requirements The VHP process is widely used by the medical industry to sterilize surgical instruments and biomedical devices but high doses of VHP may degrade the performance of flight hardware or compromise material compatibility Our goal for this study is to determine the minimum VHP process conditions for planetary protection acceptable microbial reduction levels A series of experiments were conducted to

  6. Hydrogen Peroxide and Sodium Transport in the Lung and Kidney.

    PubMed

    Shlyonsky, V; Boom, A; Mies, F

    2016-01-01

    Renal and lung epithelial cells are exposed to some significant concentrations of H2O2. In urine it may reach 100 μM, while in the epithelial lining fluid in the lung it is estimated to be in micromolar to tens-micromolar range. Hydrogen peroxide has a stimulatory action on the epithelial sodium channel (ENaC) single-channel activity. It also increases stability of the channel at the membrane and slows down the transcription of the ENaC subunits. The expression and the activity of the channel may be inhibited in some other, likely higher, oxidative states of the cell. This review discusses the role and the origin of H2O2 in the lung and kidney. Concentration-dependent effects of hydrogen peroxide on ENaC and the mechanisms of its action have been summarized. This review also describes outlooks for future investigations linking oxidative stress, epithelial sodium transport, and lung and kidney function. PMID:27073804

  7. Dissolution of ion exchange resin by hydrogen peroxide

    SciTech Connect

    Lee, S.C.

    1981-08-01

    The resin dissolution process was conducted successfully in full-scale equipment at the SRL Semiworks. A solution containing 0.001M Fe/sup 2 +/, or Fe/sup 3 +/, and 3 vol % H/sub 2/O/sub 2/ in 0.1M HNO/sub 3/ is sufficient to dissolve up to 40 vol % resin slurry (Dowex 50W-X8). Foaming and pressurization can be eliminated by maintaining the dissolution temperature below 99/sup 0/C. The recommended dissolution temperature range is 85 to 90/sup 0/C. Premixing hydrogen peroxide with all reactants will not create a safety hazard, but operating with a continual feed of hydrogen peroxide is recommended to control the dissolution rate. An air sparging rate of 1.0 to 1.5 scfm will provide sufficient mixing. Spent resin from chemical separation contains DTPA (diethylenetriaminepentaacetic acid) residue, and the resin must be washed with 0.1M NH/sub 4/ OH to remove excess DTPA before dissolution. Gamma irradiation of resin up to 4 kW-hr/L did not change the dissolution rate significantly.

  8. Antifungal efficacy of hydrogen peroxide in dental unit waterline disinfection.

    PubMed

    Szymańska, Jolanta

    2006-01-01

    The concentration and composition of fungal flora in dental unit waterlines (DUWL) were evaluated. For this purpose, water samples from unit reservoirs and high-speed handpieces, and biofilm samples from the waterline walls from units were collected. Subsequently, analogous samples from DUWL were taken before and after disinfection using agent containing hydrogen peroxide. In the examined samples, the yeast-like fungi Candida albicans and Candida curvata were found. The following species of mould were also identified: Aspergillus amstelodami, Aspergillus fumigatus, Aspergillus glaucus group, Aspergillus (=Eurotium herbariorum) repens, Citromyces spp., Geotrichum candidum, Penicillium (glabrum) frequentans, Penicillium pusillum, Penicillium turolense and Sclerotium sclerotiorum (Sclerotinia sclerotiorum). Before disinfection, Candida curvata and Candida albicans constituted the greatest proportion of the total fungi in the reservoirs water; in the water of handpieces--Candida albicans and Aspergillus glaucus group; and in the biofilm samples--Aspergillus glaucus group and Candida albicans. After disinfection, in all 3 kinds of samples, Candida albicans prevailed, constituting from 31.2-85.7 % of the total fungi. The application of agent containing hydrogen peroxide caused a significant decrease both in the number of total fungi and individual fungal species, which confirms the product effectiveness in fungal decontamination of DUWL. PMID:17196007

  9. Lemon grass (Cymbopogon citratus (D.C) Stapf) polyphenols protect human umbilical vein endothelial cell (HUVECs) from oxidative damage induced by high glucose, hydrogen peroxide and oxidised low-density lipoprotein.

    PubMed

    Campos, J; Schmeda-Hirschmann, G; Leiva, E; Guzmán, L; Orrego, R; Fernández, P; González, M; Radojkovic, C; Zuñiga, F A; Lamperti, L; Pastene, E; Aguayo, C

    2014-05-15

    The aromatic herb Cymbopogon citratus Stapf is widely used in tropical and subtropical countries in cooking, as a herbal tea, and in traditional medicine for hypertension and diabetes. Some of its properties have been associated with the in vitro antioxidant effect of polyphenols isolated from their aerial parts. However, little is known about C. citratus effects on endothelial cells oxidative injury. Using chromatographic procedures, a polyphenol-rich fraction was obtained from C. citratus (CCF) and their antioxidant properties were assessed by cooper-induced LDL oxidation assay. The main constituents of the active CCF, identified by high-performance liquid chromatography with diode-array detection and mass spectrometry (HPLC-DAD-MS), were chlorogenic acid, isoorientin and swertiajaponin. CCF 10 and 100 μg/ml diminishes reactive oxidative species (ROS) production in human umbilical vein endothelial cell (HUVECs), challenged with high D-glucose (60% inhibition), hydrogen peroxide (80% inhibition) or oxidised low-density lipoprotein (55% inhibition). CCF 10 or 100 μg/ml did not change nitric oxide (NO) production. However, CCF was able to inhibit vasoconstriction induced by the thromboxane A2 receptor agonist U46619, which suggest a NO-independent vasodilatador effect on blood vessels. Our results suggest that lemon grass antioxidant properties might prevent endothelial dysfunction associated to an oxidative imbalance promoted by different oxidative stimuli.

  10. Radiographic findings following irrigation of chronic perineal drain with hydrogen peroxide

    PubMed Central

    Melin, Alyson A.; Heckman, Andrew M.; Hussain, Shahid; Thompson, Jon S.

    2014-01-01

    INTRODUCTION Hydrogen peroxide is a widely available agent used for irrigation and disinfecting. With misuse, significant side effects have been noted ranging from nausea to abdominal cramping to portal venous gas, air embolism and death. PRESENTATION OF CASE We present an 81 year old male who developed a rectovesicular fistula following radiation for metastatic prostate cancer. He had recurrent bleeding and infections and underwent a pelvic exenteration which was complicated by a persistent pelvic abscess requiring placement of a transperineal drainage catheter. After months of persistent drainage, he noted decreased output and irrigated the catheter with 3% hydrogen peroxide. He presented to the emergency room with fever, diarrhea and abdominal cramping but no rebound or guarding. CT depicted free air in the pre-sacral space extending into the retroperitoneum and diffusely throughout the peritoneum. Given his clinical exam and upon review of imaging, we assumed his radiographic findings were related to the direct instillation of hydrogen peroxide into his chronic pelvic cavity. DISCUSSION Hydrogen peroxide has been used therapeutically for over 100 years. Hydrogen peroxide exerts direct cytotoxicity by corrosion and lipid peroxidation and indirectly by oxygen gas formation. When the oxygen produced exceeds the solubility in the blood, arterial and venous gas embolism occur. It is this sequelae of hydrogen peroxide that is described most frequently in the literature. CONCLUSION Instillation of hydrogen peroxide into a chronic pelvic cavity resulted in a benign pneumoperitoneum. This effect of hydrogen peroxide is a significant and potentially treatment altering radiographic finding. PMID:25560055

  11. Responses of rabbit pulmonary arteries to hydrogen peroxide

    SciTech Connect

    Russell, J.A.; Gugino, S.F.; Giese, E.C. )

    1991-03-15

    The effects of hydrogen peroxide on isolated rabbit intrapulmonary arteries were investigated using tissue bath techniques. Exposure of resting vessels to 10{sup {minus}7}-10{sup {minus}5} M H{sub 2}O{sub 2} caused concentration-dependent contractions that were blocked by 10{sup {minus}5} M indomethacin, 3 {times} 10{sup {minus}6} M SQ 29548 or by removal of the endothelium. Addition of a single concentration of H{sub 2}O{sub 2} to resting vessels incubated with 3 {times} 10{sup {minus}6} M SQ 29548 caused slowly developing contractions that attained approximately 80% of the response to 118mM KCL. Late phase contractions were highly resistance to the inhibitory effects of 10{sup {minus}8}-10{sup {minus}5} M isoproterenol or 10{sup {minus}7}-10{sup {minus}5} M sodium nitroprusside and they persisted in calcium-free media, in vessels incubated with 5 {times} 10{sup {minus}5} M verapamil, and after removal of the endothelium. Pulmonary arteries incubated with 3 {times} 10{sup {minus}6} M SQ 29548 and contracted by 10{sup {minus}7} M phenylephrine relaxed in response to 10{sup {minus}7}-10{sup {minus}5} M H{sub 2}O{sub 2}. H{sub 2}O{sub 2}-induced relaxations were unaffected by 10{sup {minus}4} M N{omega}-nitro-L-arginine or 10{sup {minus}5}M indomethacin but were partially depressed by removal of the endothelium. The authors conclude that H{sub 2}O{sub 2} causes: an early phase contraction via release of thromboxane A2 from endothelial cells; a late-phase contraction that is endothelium-independent and probably results from the release of calcium from intracellular stores in smooth muscle cells; and an early phase relaxation that may be due to both endothelium-dependent and endothelium-independent mechanisms. The endothelium-derived relaxing factor does not appear to be nitric oxide or a dilator prostaglandin.

  12. Folate deficiency-induced oxidative stress and apoptosis are mediated via homocysteine-dependent overproduction of hydrogen peroxide and enhanced activation of NF-kappaB in human Hep G2 cells.

    PubMed

    Chern, C L; Huang, R F; Chen, Y H; Cheng, J T; Liu, T Z

    2001-10-01

    Folate coenzymes are critical for de novo synthesis of purine and thymidine, and for interconversion of amino acids. Folate deficiency inhibits cellular proliferation, disturbs cell cycling, causes genetic damage and eventually results in cell death. Previously, we demonstrated that the demise of human hepatoma Hep G2 cells mediated by folate deficiency proceeded via a p53-independent apoptosis, and the perturbation of intracellular calcium homeostasis was also shown to be involved. To further delineate the mechanism associated with this observed phenomenon, Hep G2 cells were cultivated in the control or folate-deficient media (control media lacking folate, glycine, thymidine and hypoxanthine) for 4 weeks. At the end of this cultivation period, we found that TBARS (an index of lipid peroxidation) concentrations in the folate-deficient cells were drastically increased as compared to the control cells (0.04 vs 0.01 nmole/10(6) cells), indicating that a severe oxidative stress of the former cells had occurred. This phenomenon was also shown to coincide with the ability of these folate-deficient cells to elaborate increased amounts of H2O2 as compared to its folate-supplemented cells (2.87 vs 0.98 nmole/10(5) cells/h). Furthermore, the accelerated production of H2O2 by the folate-deficient cells was also closely correlated with the elevated homocysteine concentrations released in the culture medium (15.37 +/- 2.4 vs 3.58 +/- 2.4 micromole/L; P< 0.001). Finally, we demonstrated that folate deficiency was indeed capable of activating a redox-sensitive transcription factor, NF-kappaB, which is crucial in the control of a reactive oxygen species-mediated apoptosis. In summary, we show that folate deficiency-induced apoptosis is proceeded via the enhanced activation of NF-kappaB, which is the resulting form of the homocysteine-mediated overproduction of hydrogen peroxide.

  13. Bacterial Fucose-Rich Polysaccharide Stabilizes MAPK-Mediated Nrf2/Keap1 Signaling by Directly Scavenging Reactive Oxygen Species during Hydrogen Peroxide-Induced Apoptosis of Human Lung Fibroblast Cells

    PubMed Central

    Roy Chowdhury, Sougata; Sinha, Tridib Kumar; Sen, Ramkrishna; Basak, Ratan Kumar; Adhikari, Basudam; Bhattacharyya, Arindam

    2014-01-01

    Continuous free radical assault upsets cellular homeostasis and dysregulates associated signaling pathways to promote stress-induced cell death. In spite of the continuous development and implementation of effective therapeutic strategies, limitations in treatments for stress-induced toxicities remain. The purpose of the present study was to determine the potential therapeutic efficacy of bacterial fucose polysaccharides against hydrogen peroxide (H2O2)-induced stress in human lung fibroblast (WI38) cells and to understand the associated molecular mechanisms. In two different fermentation processes, Bacillus megaterium RB-05 biosynthesized two non-identical fucose polysaccharides; of these, the polysaccharide having a high-fucose content (∼42%) conferred the maximum free radical scavenging efficiency in vitro. Structural characterizations of the purified polysaccharides were performed using HPLC, GC-MS, and 1H/13C/2D-COSY NMR. H2O2 (300 µM) insult to WI38 cells showed anti-proliferative effects by inducing intracellular reactive oxygen species (ROS) and by disrupting mitochondrial membrane permeability, followed by apoptosis. The polysaccharide (250 µg/mL) attenuated the cell death process by directly scavenging intracellular ROS rather than activating endogenous antioxidant enzymes. This process encompasses inhibition of caspase-9/3/7, a decrease in the ratio of Bax/Bcl2, relocalization of translocated Bax and cytochrome c, upregulation of anti-apoptotic members of the Bcl2 family and a decrease in the phosphorylation of MAPKs (mitogen activated protein kinases). Furthermore, cellular homeostasis was re-established via stabilization of MAPK-mediated Nrf2/Keap1 signaling and transcription of downstream cytoprotective genes. This molecular study uniquely introduces a fucose-rich bacterial polysaccharide as a potential inhibitor of H2O2-induced stress and toxicities. PMID:25412177

  14. Bacterial fucose-rich polysaccharide stabilizes MAPK-mediated Nrf2/Keap1 signaling by directly scavenging reactive oxygen species during hydrogen peroxide-induced apoptosis of human lung fibroblast cells.

    PubMed

    Roy Chowdhury, Sougata; Sengupta, Suman; Biswas, Subir; Sinha, Tridib Kumar; Sen, Ramkrishna; Basak, Ratan Kumar; Adhikari, Basudam; Bhattacharyya, Arindam

    2014-01-01

    Continuous free radical assault upsets cellular homeostasis and dysregulates associated signaling pathways to promote stress-induced cell death. In spite of the continuous development and implementation of effective therapeutic strategies, limitations in treatments for stress-induced toxicities remain. The purpose of the present study was to determine the potential therapeutic efficacy of bacterial fucose polysaccharides against hydrogen peroxide (H2O2)-induced stress in human lung fibroblast (WI38) cells and to understand the associated molecular mechanisms. In two different fermentation processes, Bacillus megaterium RB-05 biosynthesized two non-identical fucose polysaccharides; of these, the polysaccharide having a high-fucose content (∼ 42%) conferred the maximum free radical scavenging efficiency in vitro. Structural characterizations of the purified polysaccharides were performed using HPLC, GC-MS, and (1)H/(13)C/2D-COSY NMR. H2O2 (300 µM) insult to WI38 cells showed anti-proliferative effects by inducing intracellular reactive oxygen species (ROS) and by disrupting mitochondrial membrane permeability, followed by apoptosis. The polysaccharide (250 µg/mL) attenuated the cell death process by directly scavenging intracellular ROS rather than activating endogenous antioxidant enzymes. This process encompasses inhibition of caspase-9/3/7, a decrease in the ratio of Bax/Bcl2, relocalization of translocated Bax and cytochrome c, upregulation of anti-apoptotic members of the Bcl2 family and a decrease in the phosphorylation of MAPKs (mitogen activated protein kinases). Furthermore, cellular homeostasis was re-established via stabilization of MAPK-mediated Nrf2/Keap1 signaling and transcription of downstream cytoprotective genes. This molecular study uniquely introduces a fucose-rich bacterial polysaccharide as a potential inhibitor of H2O2-induced stress and toxicities.

  15. Functional activation of the egr-1 (early growth response-1) gene by hydrogen peroxide.

    PubMed

    Nose, K; Ohba, M

    1996-06-01

    The redox-based regulation of gene expression is one of the fundamental mechanisms of cellular functions, and hydrogen peroxide seems to act as an intracellular second messenger of signal transduction of cytokines. Hydrogen peroxide at non-toxic doses induced the accumulation of mRNA for the early growth response-1 (egr-1) gene in mouse osteoblastic cells. The Egr-1 protein is a transcription factor that binds the GCGGGGGCG sequence and contains a zinc-finger structure that is essential for DNA binding. Egr-1 protein is sensitive to oxidative stress and loses specific DNA-binding activity when exposed to high levels of oxidative stress. Incubating cells with hydrogen peroxide at about 50 microM, however, increased the accumulation of Egr-1 protein, and the Egr-1 product seemed to be functional, judging by its binding activity to the GCGGGGGCG sequence and its ability to activate the chloramphenicol acetyltransferase reporter gene under the control of the human thymidine kinase enhancer containing the Egr-1 binding sequence. It was reported that the activity of Egr-1 protein as a transcription factor was negatively regulated by active oxygens. However, with appropriate concentrations of active oxygen, its capacity to bind a specific DNA sequence and to enhance the transcriptional activity of target genes is thought to be elevated.

  16. Effect of species, life stage, and water temperature on the toxicity of hydrogen peroxide to fish

    USGS Publications Warehouse

    Rach, J.J.; Schreier, T.M.; Howe, G.E.; Redman, S.D.

    1997-01-01

    Hydrogen peroxide is a drug of low regulatory priority status that is effective in treating fish and fish eggs infected by fungi. However, only limited information is available to guide fish culturists in administering hydrogen peroxide to diseased fish. Laboratory tests were conducted to determine (1) the sensitivity of brown trout Salmo trutta, lake trout Salvelinus namaycush, fathead minnow Pimephales promelas, walleye Stizostedion vitreum, channel catfish Ictalurus punctatus, and bluegill Lepomis, machrochirus to hydrogen peroxide treatments; (2) the sensitivity of various life stages of rainbow trout Oncorhynchus mykiss to hydrogen peroxide treatments; and (3) the effect of water temperature on the acute toxicity of hydrogen peroxide to three fish species. Fish were exposed to hydrogen peroxide concentrations ranging from 100 to 5,000 mu L/L (ppm) for 15-min or 45-min treatments every other day for four consecutive treatments to determine the sensitivity of various species and life stages of fish. Except for walleye, most species of fish tested (less than or equal to 2 g) tolerated hydrogen peroxide of 1,000 mu L/L or greater. Walleyes were sensitive to hydrogen peroxide concentrations as low as 100 mu L/L. A correlation was found between the toxicity of hydrogen peroxide and the life stages of rainbow trout; larger fish were more sensitive. Generally, the toxicity of hydrogen peroxide increased for all species as water temperature increased. The results of these experiments demonstrate that it is important to consider the effects of species, life stage, and water temperature when conducting hydrogen peroxide treatments.

  17. Photoluminescence of MoS2 quantum dots quenched by hydrogen peroxide: A fluorescent sensor for hydrogen peroxide

    NASA Astrophysics Data System (ADS)

    Gan, Zhixing; Gui, Qingfeng; Shan, Yun; Pan, Pengfei; Zhang, Ning; Zhang, Lifa

    2016-09-01

    By cutting MoS2 microcrystals to quantum dots (QDs) of sizes below 10 nm, the photoluminescence (PL) at ca. 450 nm can be detected easily due to the quantum confinement effects across the 2D planes. The PL is stable under continuous irradiation of UV light but gradually quenches when treated with an increasing concentration of hydrogen peroxide. Time-resolved PL and Raman spectra imply that H2O2 causes the partial oxidation of MoS2 QDs. First-principles calculations reveal that the MoS2 QDs with oxygen impurity are of indirect bandgap structures showing no notable PL. And absorption spectra verify that the PL of MoS2 QDs quenched by H2O2 is attributed to the oxidation. The integrated PL intensity and H2O2 concentration show an exponential relationship in the range of 2-20 μM, suggesting that MoS2 QDs are potential fluorescent probes for hydrogen peroxide sensing in a physiological environment.

  18. Presence of Hydrogen Peroxide, a Source of Hydroxyl Radicals, in Acid Electrolyzed Water

    PubMed Central

    Mokudai, Takayuki; Nakamura, Keisuke; Kanno, Taro; Niwano, Yoshimi

    2012-01-01

    Background Acid electrolyzed water (AEW), which is produced through the electrolysis of dilute sodium chloride (NaCl) or potassium chloride solution, is used as a disinfectant in various fields because of its potent antimicrobial activity. The hydroxyl radical, an oxygen radical species, is often suggested as a putative active ingredient for AEW antimicrobial activity. Methodology/Principal Findings The aim of the present study is to detect hydroxyl radicals in AEW. The hydroxyl radicals in AEW prepared under different conditions were determined using an electron spin resonance (ESR) technique. A signal from 5,5-dimethyl-1-pyrroline N-oxide (DMPO)-OH, an adduct of DMPO and the hydroxyl radical, was detected in AEW prepared by double or triple electrolyses of 1% NaCl but not of 0.1% NaCl solution. Then the presence of hydrogen peroxide as a proposed source of hydroxyl radicals was examined using a combination of ESR and a Fenton reaction. The DMPO-OH signal was clearly detected, even in AEW prepared by single electrolysis of 0.1% NaCl solution, when ferrous sulfate was added to induce a Fenton reaction, indicating the presence of hydrogen peroxide in the AEW. Since sodium formate, a hydroxyl radical scavenger, did not affect the bactericidal activity of AEW, it is concluded that the radical is unlikely to contribute to the antimicrobial activity of AEW, although a small amount of the radical is produced from hydrogen peroxide. Dimethyl sulfoxide, the other hydroxyl radical scavenger used in the present study, canceled the bactericidal activity of AEW, accompanied by complete depletion of free available chlorine, suggesting that hypochlorous acid is probably a major contributor to the antimicrobial activity. Conclusions It is strongly suggested that although hydrogen peroxide is present in AEW as a source of hydroxyl radicals, the antimicrobial activity of AEW does not depend on these radicals. PMID:23029505

  19. Melatonin protects skin keratinocyte from hydrogen peroxide-mediated cell death via the SIRT1 pathway

    PubMed Central

    Lee, Ju-Hee; Moon, Ji-Hong; Nazim, Uddin MD.; Lee, You-Jin; Seol, Jae-Won; Eo, Seong-Kug; Lee, John-Hwa; Park, Sang-Youel

    2016-01-01

    Melatonin (N-acetyl-5-methoxytryptamine), which is primarily synthesized in and secreted from the pineal gland, plays a pivotal role in cell proliferation as well as in the regulation of cell metastasis and cell survival in a diverse range of cells. The aim of this study is to investigate protection effect of melatonin on H2O2-induced cell damage and the mechanisms of melatonin in human keratinocytes. Hydrogen peroxide dose-dependently induced cell damages in human keratinocytes and co-treatment of melatonin protected the keratinocytes against H2O2-induced cell damage. Melatonin treatment activated the autophagy flux signals, which were identified by the decreased levels of p62 protein. Inhibition of autophagy flux via an autophagy inhibitor and ATG5 siRNA technique blocked the protective effects of melatonin against H2O2-induced cell death in human keratinocytes. And we found the inhibition of sirt1 using sirtinol and sirt1 siRNA reversed the protective effects of melatonin and induces the autophagy process in H2O2-treated cells. This is the first report demonstrating that autophagy flux activated by melatonin protects human keratinocytes through sirt1 pathway against hydrogen peroxide-induced damages. And this study also suggest that melatonin could potentially be utilized as a therapeutic agent in skin disease. PMID:26918354

  20. A combination of four effective components derived from Sheng-mai san attenuates hydrogen peroxide-induced injury in PC12 cells through inhibiting Akt and MAPK signaling pathways.

    PubMed

    Cao, Guo-Sheng; Li, Shao-Xia; Wang, Yan; Xu, Ying-Qiong; Lv, Yan-Ni; Kou, Jun-Ping; Yu, Bo-Yang

    2016-07-01

    The present study was designed to investigate whether a combination of four effective components derived from Sheng-mai san (SMXZF; ginsenoside Rb1: ginsenoside Rg1: DT-13: Schizandrol A as 6 : 9 : 4 : 5) could attenuate hydrogen peroxide (H2O2)-induced injury in PC12 cells, focusing on the Akt and MAPK pathways . The PC12 cells were exposed to H2O2 (400 μmol·L(-1)) for 1 h in the presence or absence of SMXZF pre-treatment for 24 h. Cell viability was measured by MTT assay. The efflux of lactate dehydrogenase (LDH), the intracellular content of malondialdehyde (MDA), the activities of superoxide dismutase (SOD), and caspase-3 were also determined. Cell apoptosis was measured by Hoechst 33342 staining and Annexin V-FITC/PI staining method. The expression of Bcl-2, Bax, cleaved caspase-3, Akt, and MAPKs were detected by Western blotting analyses. SMXZF pretreatment significantly increased the cell viability and SOD activity and improved the cell morphological changes, while reduced the levels of LDH and MDA at the concentrations of 0.1, 1 and 10 μg·mL(-1). SMXZF also inhibited H2O2-induced apoptosis in PC12 cells. Moreover, SMXZF reduced the activity of caspase-3, up-regulated the protein ratio of Bcl-2 and Bax and inhibited the expression of cleaved caspase-3, p-Akt, p-p38, p-JNK and p-ERK1/2 in H2O2-induced PC12 cells. Co-incubation of Akt inhibitor or p38 inhibitor partly attenuated the protection of SMXZF against H2O2-injured PC12 cells. In conclusion, our findings suggested that SMXZF attenuated H2O2-induced injury in PC12 cells by inhibiting Akt and MAPKs signaling pathways, which might shed insights on its neuroprotective mechanism. PMID:27507201

  1. The electrochemistry of SIMFUEL in dilute alkaline hydrogen peroxide solutions

    NASA Astrophysics Data System (ADS)

    Goldik, Jon

    The work described in this thesis is a study of the electrochemistry of SIMFUEL (SIMulated nuclear FUEL) in dilute, alkaline hydrogen peroxide solutions. In the first set of experiments, the reaction of H2O 2 on SIMFUEL electrodes was studied electrochemically and under open circuit conditions in 0.1 mol L-1 NaCl solutions at pH 9.8. The composition of the oxidized UO2 surface was determined by X-ray photoelectron spectroscopy. Hydrogen peroxide reduction was found to be catalyzed by the formation of a mixed UIV/UV (UO 2+x) surface layer, but to be blocked by the accumulation of UVI species (UO3· yH2O or adsorbed (UO2)2+) on the electrode surface. The formation of this UVI layer blocks both H2O2 reduction and oxidation, thereby inhibiting the potentially rapid H2O2 decomposition reaction to H2O and O2. Decomposition is found to proceed at a rate controlled by the desorption of the adsorbed (UO2)2+ or reduction of adsorbed O2 species. Reduction of (O2) ads is coupled to the slow oxidative dissolution of UO2 and formation of a corrosion product deposit of UO3· yH2O. In the second series of experiments, the electrochemical reduction of hydrogen peroxide on SIMFUEL was studied using the steady-state polarization technique. Kinetic parameters for the reaction, such as Tafel slopes and reaction orders, were determined. The results were interpreted in terms of a chemical-electrochemical mechanism involving UIV/UV donor-acceptor reduction sites. The large values of the Tafel slopes and the fractional reaction orders with respect to H2O2 can be understood in terms of the potential-dependent surface coverage of active sites, similar to that observed in the reduction of hydrogen peroxide on oxidized copper surfaces. The effects of pH over the range 10-13 were also investigated. The H2O 2 reduction currents were nearly independent of pH in the range 10-11, but were slowed at more alkaline values. The change in pH dependence appears to be related to the acid-base properties

  2. [Acute ischemia of the hand, an unknown complication of the hydrogen peroxide irrigation. Case report].

    PubMed

    Zemirline, A; Loaëc, F; Hélaine, L; Richou, J; Le Nen, D

    2011-04-01

    We report a case of acute transitional ischemia of the hand with acute compartment syndrome of the forearm, following hydrogen peroxide irrigation of a wound. We discuss the physiopathology and management of this complication. Along with numerous related cases of gas embolism, this complication emphasizes the risks of using hydrogen peroxide under pressure, notably in hand surgery.

  3. Role of hydrogen peroxide and hydroxyl radical in pyrite oxidation by molecular oxygen

    NASA Astrophysics Data System (ADS)

    Schoonen, Martin A. A.; Harrington, Andrea D.; Laffers, Richard; Strongin, Daniel R.

    2010-09-01

    Hydrogen peroxide and hydroxyl radical are readily formed during the oxidation of pyrite with molecular oxygen over a wide range of pH conditions. However, pretreatment of the pyrite surface influences how much of the intermediates are formed and their fate. Acid-washed pyrite produces significant amounts of hydrogen peroxide and hydroxyl radical when suspended in air-saturated water. However, the hydrogen peroxide concentration shows an exponential decrease with time. Suspensions made with partially oxidized pyrite yield significantly lower amounts of hydrogen peroxide product. The presence of Fe(III)-oxide or Fe(III)-hydroxide patches facilitates the conversion of hydrogen peroxide to oxygen and water. Hence, the degree to which a pyrite surface is covered with patches of Fe(III)-oxide or Fe(III)-hydroxide patches is an important control on the concentration of hydrogen peroxide in solution. Hydrogen peroxide appears to be an important intermediate in the four-electron transfer from pyrite to molecular oxygen. Addition of catalase, an enzyme that decomposes hydrogen peroxide to water and molecular oxygen, to a pyrite suspension reduces the oxidation rate by 40%. By contrast, hydroxyl radical does not appear to play a significant role in the oxidation mechanism. It is estimated on the basis of a molecular oxygen and sulfate mass balance that 5-6% of the molecular oxygen is consumed without forming sulfate.

  4. Hydrogen peroxide and povidone-lodine solution--a dangerous combination.

    PubMed

    2011-02-01

    When mixed with povidone-iodine solution, hydrogen peroxide can release enough oxygen to cause sealed waste containers to burst open. Such risks can also result from using a sealed container to collect hydrogen peroxide that has mixed with body fluids (for instance, in a debridement procedure). Staff should be instructed to avoid both practices. PMID:23444560

  5. An Experimental Investigation of Hypergolic Ignition Delay of Hydrogen Peroxide with Fuel Mixtures

    NASA Technical Reports Server (NTRS)

    Blevins, John A.; Gostowski, Rudy; Chianese, Silvio

    2003-01-01

    An experimental evaluation of decomposition and ignition delay of hydrogen peroxide at concentrations of 80% to 98% with combinations of hydrocarbon fuels, tertiary amines and transition metal chelates will be presented in the proposed paper. The results will be compared to hydrazine ignition delays with hydrogen peroxide and nitric acid mixtures using the same test apparatus.

  6. Oxygen from Hydrogen Peroxide. A Safe Molar Volume-Molar Mass Experiment.

    ERIC Educational Resources Information Center

    Bedenbaugh, John H.; And Others

    1988-01-01

    Describes a molar volume-molar mass experiment for use in general chemistry laboratories. Gives background technical information, procedures for the titration of aqueous hydrogen peroxide with standard potassium permanganate and catalytic decomposition of hydrogen peroxide to produce oxygen, and a discussion of the results obtained in three…

  7. Development of vapor phase hydrogen peroxide sterilization process for spacecraft applications

    NASA Technical Reports Server (NTRS)

    Rohatgi, N.; Schubert, W.; Knight, J.; Quigley, M.; Forsberg, G.; Ganapathi, G.; Yarbrough, C.; Koukol, R.

    2001-01-01

    This paper will present test data and discussion on the work we are conducting at JPL to address the following issues: 1) efficacy of sterilization process; 2) diffusion of hydrogen peroxide under sterilization process conditions into hard to reach places; 3) materials and components compatibility with the sterilization process and 4) development of methodology to protect sensitive components from hydrogen peroxide vapor.

  8. Efficacy of Mouthwashes Containing Hydrogen Peroxide on Tooth Whitening.

    PubMed

    Karadas, Muhammet; Hatipoglu, Omer

    2015-01-01

    The aim of this study was to analyze the efficacy of mouthwashes containing hydrogen peroxide compared with 10% carbamide peroxide (CP) gel. Fifty enamel-dentin samples were obtained from bovine incisors and then stained in a tea solution. The stained samples were randomly divided into five groups according to the whitening product applied (n = 10): AS: no whitening (negative control), with the samples stored in artificial saliva; CR: Crest 3D White mouthwash; LS: Listerine Whitening mouthwash; SC: Scope White mouthwash; and OP group: 10% CP Opalescence PF (positive control). Color measurements were carried out with a spectrophotometer before staining, after staining, and on the 7th, 28th, and 56th day of the whitening period. The data were analyzed using two-way analysis of variance followed by a Tukey post hoc test. The color change (ΔE) was significantly greater in all the groups compared to that of the AS group. After 56 days, no significant differences were found among the mouthwash products with respect to color change (P > 0.05). The whiteness of the teeth treated with the mouthwashes increased significantly over time. Nevertheless, the color change achieved with the mouthwashes was significantly lower than that achieved with the 10% CP at-home bleaching gel.

  9. Efficacy of Mouthwashes Containing Hydrogen Peroxide on Tooth Whitening

    PubMed Central

    Karadas, Muhammet; Hatipoglu, Omer

    2015-01-01

    The aim of this study was to analyze the efficacy of mouthwashes containing hydrogen peroxide compared with 10% carbamide peroxide (CP) gel. Fifty enamel-dentin samples were obtained from bovine incisors and then stained in a tea solution. The stained samples were randomly divided into five groups according to the whitening product applied (n = 10): AS: no whitening (negative control), with the samples stored in artificial saliva; CR: Crest 3D White mouthwash; LS: Listerine Whitening mouthwash; SC: Scope White mouthwash; and OP group: 10% CP Opalescence PF (positive control). Color measurements were carried out with a spectrophotometer before staining, after staining, and on the 7th, 28th, and 56th day of the whitening period. The data were analyzed using two-way analysis of variance followed by a Tukey post hoc test. The color change (ΔE) was significantly greater in all the groups compared to that of the AS group. After 56 days, no significant differences were found among the mouthwash products with respect to color change (P > 0.05). The whiteness of the teeth treated with the mouthwashes increased significantly over time. Nevertheless, the color change achieved with the mouthwashes was significantly lower than that achieved with the 10% CP at-home bleaching gel. PMID:26295061

  10. Efficacy of Mouthwashes Containing Hydrogen Peroxide on Tooth Whitening.

    PubMed

    Karadas, Muhammet; Hatipoglu, Omer

    2015-01-01

    The aim of this study was to analyze the efficacy of mouthwashes containing hydrogen peroxide compared with 10% carbamide peroxide (CP) gel. Fifty enamel-dentin samples were obtained from bovine incisors and then stained in a tea solution. The stained samples were randomly divided into five groups according to the whitening product applied (n = 10): AS: no whitening (negative control), with the samples stored in artificial saliva; CR: Crest 3D White mouthwash; LS: Listerine Whitening mouthwash; SC: Scope White mouthwash; and OP group: 10% CP Opalescence PF (positive control). Color measurements were carried out with a spectrophotometer before staining, after staining, and on the 7th, 28th, and 56th day of the whitening period. The data were analyzed using two-way analysis of variance followed by a Tukey post hoc test. The color change (ΔE) was significantly greater in all the groups compared to that of the AS group. After 56 days, no significant differences were found among the mouthwash products with respect to color change (P > 0.05). The whiteness of the teeth treated with the mouthwashes increased significantly over time. Nevertheless, the color change achieved with the mouthwashes was significantly lower than that achieved with the 10% CP at-home bleaching gel. PMID:26295061

  11. Kinetics of hydrogen peroxide decomposition by catalase: hydroxylic solvent effects.

    PubMed

    Raducan, Adina; Cantemir, Anca Ruxandra; Puiu, Mihaela; Oancea, Dumitru

    2012-11-01

    The effect of water-alcohol (methanol, ethanol, propan-1-ol, propan-2-ol, ethane-1,2-diol and propane-1,2,3-triol) binary mixtures on the kinetics of hydrogen peroxide decomposition in the presence of bovine liver catalase is investigated. In all solvents, the activity of catalase is smaller than in water. The results are discussed on the basis of a simple kinetic model. The kinetic constants for product formation through enzyme-substrate complex decomposition and for inactivation of catalase are estimated. The organic solvents are characterized by several physical properties: dielectric constant (D), hydrophobicity (log P), concentration of hydroxyl groups ([OH]), polarizability (α), Kamlet-Taft parameter (β) and Kosower parameter (Z). The relationships between the initial rate, kinetic constants and medium properties are analyzed by linear and multiple linear regression.

  12. Hydrogen peroxide as an endothelium-derived hyperpolarizing factor.

    PubMed

    Shimokawa, Hiroaki; Matoba, Tetsuya

    2004-06-01

    Vascular endothelium plays an important role in maintaining vascular homeostasis by synthesizing and releasing several vasodilating factors, such as prostacyclin, nitric oxide (NO), and a yet unidentified endothelium-derived hyperpolarizing factor (EDHF). Possible candidates for EDHF include epoxyeicosatrienoic acids (EETs), endothelium-derived potassium ions (K(+)), and as we have recently identified, hydrogen peroxide (H2O2). Electrical communication between endothelial and smooth muscle cells through gap junctions has also been suggested to be involved in endothelium-dependent hyperpolarization. Among the above candidates, the H2O2 hypothesis well explains the pathophysiological interactions between NO and EDHF and re-highlights the physiological roles of the reactive oxygen species (ROS) in endothelium-dependent vascular responses. This brief review summarizes our current knowledge about H2O2 as an EDHF, with special reference to its production by the endothelium, its action on membrane potentials and its pathophysiological roles. PMID:15026032

  13. Temperature-dependent absorption cross sections for hydrogen peroxide vapor

    NASA Technical Reports Server (NTRS)

    Nicovich, J. M.; Wine, P. H.

    1988-01-01

    Relative absorption cross sections for hydrogen peroxide vapor were measured over the temperature ranges 285-381 K for lambda = 230 nm-295 nm and 300-381 K for lambda = 193 nm-350 nm. The well established 298 K cross sections at 202.6 and 228.8 nm were used as an absolute calibration. A significant temperature dependence was observed at the important tropospheric photolysis wavelengths lambda over 300 nm. Measured cross sections were extrapolated to lower temperatures, using a simple model which attributes the observed temperature dependence to enhanced absorption by molecules possessing one quantum of O-O stretch vibrational excitation. Upper tropospheric photodissociation rates calculated using the extrapolated cross sections are about 25 percent lower than those calculated using currently recommended 298 K cross sections.

  14. Vapor Hydrogen Peroxide as Alternative to Dry Heat Microbial Reduction

    NASA Technical Reports Server (NTRS)

    Cash, Howard A.; Kern, Roger G.; Chung, Shirley Y.; Koukol, Robert C.; Barengoltz, Jack B.

    2006-01-01

    The Jet Propulsion Laboratory, in conjunction with the NASA Planetary Protection Officer, has selected vapor phase hydrogen peroxide (VHP) sterilization process for continued development as a NASA approved sterilization technique for spacecraft subsystems and systems. The goal is to include this technique, with appropriate specification, in NPG8020.12C as a low temperature complementary technique to the dry heat sterilization process. A series of experiments were conducted in vacuum to determine VHP process parameters that provided significant reductions in spore viability while allowing survival of sufficient spores for statistically significant enumeration. With this knowledge of D values, sensible margins can be applied in a planetary protection specification. The outcome of this study provided an optimization of test sterilizer process conditions: VHP concentration, process duration, a process temperature range for which the worst case D value may be imposed, a process humidity range for which the worst case D value may be imposed, and robustness to selected spacecraft material substrates.

  15. Plasma Depolymerization of Chitosan in the Presence of Hydrogen Peroxide

    PubMed Central

    Ma, Fengming; Wang, Zhenyu; Zhao, Haitian; Tian, Shuangqi

    2012-01-01

    The depolymerization of chitosan by plasma in the presence of hydrogen peroxide (H2O2) was investigated. The efficiency of the depolymerization was demonstrated by means of determination of viscosity-average molecular weight and gel permeation chromatography (GPC). The structure of the depolymerized chitosan was characterized by Fourier-transform infrared spectra (FT-IR), ultraviolet spectra (UV) and X-ray diffraction (XRD). The results showed that chitosan can be effectively degradated by plasma in the presence of H2O2. The chemical structure of the depolymerized chitosan was not obviously modified. The combined plasma/H2O2 method is significantly efficient for scale-up manufacturing of low molecular weight chitosan. PMID:22837727

  16. Kinetics of hydrogen peroxide decomposition by catalase: hydroxylic solvent effects.

    PubMed

    Raducan, Adina; Cantemir, Anca Ruxandra; Puiu, Mihaela; Oancea, Dumitru

    2012-11-01

    The effect of water-alcohol (methanol, ethanol, propan-1-ol, propan-2-ol, ethane-1,2-diol and propane-1,2,3-triol) binary mixtures on the kinetics of hydrogen peroxide decomposition in the presence of bovine liver catalase is investigated. In all solvents, the activity of catalase is smaller than in water. The results are discussed on the basis of a simple kinetic model. The kinetic constants for product formation through enzyme-substrate complex decomposition and for inactivation of catalase are estimated. The organic solvents are characterized by several physical properties: dielectric constant (D), hydrophobicity (log P), concentration of hydroxyl groups ([OH]), polarizability (α), Kamlet-Taft parameter (β) and Kosower parameter (Z). The relationships between the initial rate, kinetic constants and medium properties are analyzed by linear and multiple linear regression. PMID:22565543

  17. What is the role of hydrogen peroxide in plant peroxisomes?

    PubMed

    Corpas, Francisco J

    2015-11-01

    Plant peroxisomes are unusual subcellular compartments with an apparent simple morphology but with complex metabolic activity. The presence of signal molecules, such as hydrogen peroxide (H(2)O(2)) and nitric oxide inside plant peroxisomes have added new functions in the cross-talk events among organelles and cells under physiological and stress conditions. Moreover, recent advances in proteomic analyses of plant peroxisomes have identified new protein candidates involved in several novel metabolic pathways. With all these new data, the present concise manuscript will focus on the relevance of the peroxisomal H(2)O(2) and its two main antioxidant enzymes, catalase and membrane-bound ascorbate peroxidase, which regulate its level and consequently its potential functions.

  18. Greywater disinfection with the environmentally friendly Hydrogen Peroxide Plus (HPP).

    PubMed

    Ronen, Zeev; Guerrero, Adriana; Gross, Amit

    2010-01-01

    Hydrogen Peroxide Plus (HPP) is a newly developed, stabilized-H(2)O(2)-based compound. This study was aimed at determining the disinfection efficiency of HPP in greywater (GW), assessing HPP dose requirements and evaluating the feasibility of its use in small-scale GW-treatment systems. Fecal coliforms were the most sensitive to treatment, followed by somatic coliphages and F+ bacteriophages. The calculated HPP dose required to reduce fecal coliform counts by 99% was 125mg H(2)O(2)L(-1), with a contact time of 35min. The use of HPP was found feasible and comparable to the use of chlorine for small systems with a flow rate of 5m(3)d(-1). HPP is suggested as an alternative for GW disinfection in small communities and private houses.

  19. Alkaline hydrogen peroxide pretreatment of softwood: hemicellulose degradation pathways.

    PubMed

    Alvarez-Vasco, Carlos; Zhang, Xiao

    2013-12-01

    This study investigated softwood hemicelluloses degradation pathways during alkaline hydrogen peroxide (AHP) pretreatment of Douglas fir. It was found that glucomannan is much more susceptible to alkaline pretreatment than xylan. Organic acids, including lactic, succinic, glycolic and formic acid are the predominant products from glucomannan degradation. At low treatment temperature (90°C), a small amount of formic acid is produced from glucomannan, whereas glucomannan degradation to lactic acid and succinic acid becomes the main reactions at 140°C and 180°C. The addition of H2O2 during alkaline pretreatment of D. fir led to a significant removal of lignin, which subsequently facilitated glucomannan solubilization. However, H2O2 has little direct effect on the glucomannan degradation reaction. The main degradation pathways involved in glucomannan conversion to organics acids are elucidated. The results from this study demonstrate the potential to optimize pretreatment conditions to maximize the value of biomass hemicellulose.

  20. Pd nanoparticle-modified electrodes for nonenzymatic hydrogen peroxide detection

    NASA Astrophysics Data System (ADS)

    Wang, Jue; Chen, Xue-jiao; Liao, Kai-ming; Wang, Guang-hou; Han, Min

    2015-08-01

    A hydrogen peroxide (H2O2) sensor based on Pd nanoparticles (NPs) and glassy carbon electrodes (GCEs) is fabricated. Pd NPs are deposited on GCEs by using a gas phase cluster beam deposition technique. The NP-deposited electrodes show enhanced electrocatalytic activity in reduction of H2O2. The electrode with an optimized NP coverage of 85 % has a high selective and stable nonenzymatic sensing ability of H2O2 with a low detection limit (3.4 × 10-7 M), high sensitivity (50.9 μA mM-1), and a wide linear range (from 1.0 × 10-6 to 6.0 × 10-3 M). The reduction peak potential of the electrode is close to -0.12 V, which enables high selective amperometric detection of H2O2 at a low applied potential.

  1. Effect of acetone extract from stem bark of Acacia species (A. dealbata, A. ferruginea and A. leucophloea) on antioxidant enzymes status in hydrogen peroxide-induced HepG2 cells

    PubMed Central

    Sowndhararajan, Kandhasamy; Hong, Sunghyun; Jhoo, Jin-Woo; Kim, Songmun; Chin, Nyuk Ling

    2015-01-01

    Acacia species are multipurpose trees, widely used in the traditional systems of medicine to treat various ailments. The major objective of the present study was to determine the gene expression of enzymatic antioxidants by acetone extract from the stem bark of three Acacia species (Acacia dealbata, Acacia ferruginea and Acacia leucophloea) in hydrogen peroxide (H2O2)-induced human hepatoma (HepG2) cells. The expression of antioxidant enzymes such as superoxide dismutase containing copper–zinc (CuZnSOD)/manganese (MnSOD), catalase (CAT) and glutathione peroxidase (GPx) in HepG2 cells was evaluated by real-time PCR. The results of antioxidant enzyme expression in real-time PCR study revealed that the H2O2 (200 μM) challenged HepG2 cells reduced the expression of enzymes such as SOD, GPx and CAT. However, the cells pre-treated with acetone extracts of all the three Acacia species significantly (P > 0.05) up-regulated the expression of antioxidant enzymes in a concentration dependent manner (25, 50 and 75 μg/mL). In conclusion, the findings of our study demonstrated that the acetone extract of Acacia species effectively inhibited H2O2 mediated oxidative stress and may be useful as a therapeutic agent in preventing oxidative stress mediated diseases. PMID:26586994

  2. Effect of acetone extract from stem bark of Acacia species (A. dealbata, A. ferruginea and A. leucophloea) on antioxidant enzymes status in hydrogen peroxide-induced HepG2 cells.

    PubMed

    Sowndhararajan, Kandhasamy; Hong, Sunghyun; Jhoo, Jin-Woo; Kim, Songmun; Chin, Nyuk Ling

    2015-11-01

    Acacia species are multipurpose trees, widely used in the traditional systems of medicine to treat various ailments. The major objective of the present study was to determine the gene expression of enzymatic antioxidants by acetone extract from the stem bark of three Acacia species (Acacia dealbata, Acacia ferruginea and Acacia leucophloea) in hydrogen peroxide (H2O2)-induced human hepatoma (HepG2) cells. The expression of antioxidant enzymes such as superoxide dismutase containing copper-zinc (CuZnSOD)/manganese (MnSOD), catalase (CAT) and glutathione peroxidase (GPx) in HepG2 cells was evaluated by real-time PCR. The results of antioxidant enzyme expression in real-time PCR study revealed that the H2O2 (200 μM) challenged HepG2 cells reduced the expression of enzymes such as SOD, GPx and CAT. However, the cells pre-treated with acetone extracts of all the three Acacia species significantly (P > 0.05) up-regulated the expression of antioxidant enzymes in a concentration dependent manner (25, 50 and 75 μg/mL). In conclusion, the findings of our study demonstrated that the acetone extract of Acacia species effectively inhibited H2O2 mediated oxidative stress and may be useful as a therapeutic agent in preventing oxidative stress mediated diseases.

  3. Effect of acetone extract from stem bark of Acacia species (A. dealbata, A. ferruginea and A. leucophloea) on antioxidant enzymes status in hydrogen peroxide-induced HepG2 cells.

    PubMed

    Sowndhararajan, Kandhasamy; Hong, Sunghyun; Jhoo, Jin-Woo; Kim, Songmun; Chin, Nyuk Ling

    2015-11-01

    Acacia species are multipurpose trees, widely used in the traditional systems of medicine to treat various ailments. The major objective of the present study was to determine the gene expression of enzymatic antioxidants by acetone extract from the stem bark of three Acacia species (Acacia dealbata, Acacia ferruginea and Acacia leucophloea) in hydrogen peroxide (H2O2)-induced human hepatoma (HepG2) cells. The expression of antioxidant enzymes such as superoxide dismutase containing copper-zinc (CuZnSOD)/manganese (MnSOD), catalase (CAT) and glutathione peroxidase (GPx) in HepG2 cells was evaluated by real-time PCR. The results of antioxidant enzyme expression in real-time PCR study revealed that the H2O2 (200 μM) challenged HepG2 cells reduced the expression of enzymes such as SOD, GPx and CAT. However, the cells pre-treated with acetone extracts of all the three Acacia species significantly (P > 0.05) up-regulated the expression of antioxidant enzymes in a concentration dependent manner (25, 50 and 75 μg/mL). In conclusion, the findings of our study demonstrated that the acetone extract of Acacia species effectively inhibited H2O2 mediated oxidative stress and may be useful as a therapeutic agent in preventing oxidative stress mediated diseases. PMID:26586994

  4. Protective Effects of Minor Components of Curcuminoids on Hydrogen Peroxide-Treated Human HaCaT Keratinocytes.

    PubMed

    Liu, Yuh-Hwa; Lin, Yin-Shiou; Huang, Yu-Wei; Fang, Sheng-Uei; Lin, Shyr-Yi; Hou, Wen-Chi

    2016-05-11

    Hydrogen peroxide, one of the reactive oxygen species (ROS), can cause intracellular oxidative stress associated with skin aging and/or photoaging. Curcumin, a polyphenol in turmeric, has been reported to exhibit biological activity. In this study, five naturally occurring curcuminoids [curcumin, demethoxycurcumin (DMC), bisdemethoxycurcumin (BDMC), monohydroxy-DMC, and monohydroxy-BDMC] were used to investigate their protective roles against hydrogen peroxide-induced oxidative stress in the immortalized human keratinocyte cell lines (HaCaT cells). These five curcuminoids at 10 μM, but not at 5 μM, were shown to exhibit cytotoxicities toward HaCaT keratinocytes. Therefore, a 5 μM concentration of the five curcuminoids was selected for further investigations. Cells were pretreated with or without curcuminoids for 2.5 h before 24-h hydrogen peroxide (150 μM) treatments. Pretreatments with the minor components monohydroxy-DMC or monohydroxy-BDMC, but not curcumin, DMC, and BDMC, showed protective activity, elevating cell viability compared to cells with direct hydrogen peroxide treatments. Pretreatments with monohydroxy-DMC and monohydroxy-BDMC showed the best protective effects, reducing apoptotic cell populations and intracellular ROS, as demonstrated by flow cytometry, as well as reducing the changes of the mitochondrial membrane potential compared to cells with direct hydrogen peroxide treatments. The pretreatments with monohydroxy-DMC and monohydroxy-BDMC reduced c-jun and c-fos mRNA expression and p53 tumor suppressor protein expression and increased HO-1 protein expression and glutathione peroxidase (GPx) activity, respectively, compared to cells with direct hydrogen peroxide treatments. The five curcuminoids exhibited similar hydrogen peroxide-scavenging activity in vitro. It was proposed that monohydroxy-DMC and monohydroxy-BDMC could induce antioxidant defense systems better than curcumin, DMC, or BDMC could against hydrogen peroxide-induced oxidative

  5. Development of hydrogen peroxide technique for bioburden reduction

    NASA Astrophysics Data System (ADS)

    Rohatgi, N.; Schwartz, L.; Stabekis, P.; Barengoltz, J.

    In order to meet the National Aeronautics and Space Administration (NASA) Planetary Protection microbial reduction requirements for Mars in-situ life detection and sample return missions, entire planetary spacecraft (including planetary entry probes and planetary landing capsules) may have to be exposed to a qualified sterilization process. Presently, dry heat is the only NASA approved sterilization technique available for spacecraft application. However, with the increasing use of various man-made materials, highly sophisticated electronic circuit boards, and sensors in a modern spacecraft, compatibility issues may render this process unacceptable to design engineers and thus impractical to achieve terminal sterilization of the entire spacecraft. An alternative vapor phase hydrogen peroxide sterilization process, which is currently used in various industries, has been selected for further development. Strategic Technology Enterprises, Incorporated (STE), a subsidiary of STERIS Corporation, under a contract from the Jet Propulsion Laboratory (JPL) is developing systems and methodologies to decontaminate spacecraft using vaporized hydrogen peroxide (VHP) technology. The VHP technology provides an effective, rapid and low temperature means for inactivation of spores, mycobacteria, fungi, viruses and other microorganisms. The VHP application is a dry process affording excellent material compatibility with many of the components found in spacecraft such as polymers, paints and electronic systems. Furthermore, the VHP process has innocuous residuals as it decomposes to water vapor and oxygen. This paper will discuss the approach that is being used to develop this technique and will present lethality data that have been collected to establish deep vacuum VHP sterilization cycles. In addition, the application of this technique to meet planetary protection requirements will be addressed.

  6. Chemiluminescent Nanomicelles for Imaging Hydrogen Peroxide and Self-Therapy in Photodynamic Therapy

    PubMed Central

    Chen, Rui; Zhang, Luzhong; Gao, Jian; Wu, Wei; Hu, Yong; Jiang, Xiqun

    2011-01-01

    Hydrogen peroxide is a signal molecule of the tumor, and its overproduction makes a higher concentration in tumor tissue compared to normal tissue. Based on the fact that peroxalates can make chemiluminescence with a high efficiency in the presence of hydrogen peroxide, we developed nanomicelles composed of peroxalate ester oligomers and fluorescent dyes, called peroxalate nanomicelles (POMs), which could image hydrogen peroxide with high sensitivity and stability. The potential application of the POMs in photodynamic therapy (PDT) for cancer was also investigated. It was found that the PDT-drug-loaded POMs were sensitive to hydrogen peroxide, and the PDT drug could be stimulated by the chemiluminescence from the reaction between POMs and hydrogen peroxide, which carried on a self-therapy of the tumor without the additional laser light resource. PMID:21765637

  7. Inactivation of possible micromycete food contaminants using the low-temperature plasma and hydrogen peroxide

    SciTech Connect

    Čeřovský, M.; Khun, J.; Rusová, K.; Scholtz, V.; Soušková, H.

    2013-09-15

    The inhibition effect of hydrogen peroxide aerosol, low-temperature plasma and their combinations has been studied on several micromycetes spores. The low-temperature plasma was generated in corona discharges in the open air apparatus with hydrogen peroxide aerosol. Micromycete spores were inoculated on the surface of agar plates, exposed solely to the hydrogen peroxide aerosol, corona discharge or their combination. After incubation the diameter of inhibition zone was measured. The solely positive corona discharge exhibits no inactivation effect, the solely negative corona discharge and solely hydrogen peroxide aerosol exhibit the inactivation effect, however their combinations exhibit to be much more effective. Low-temperature plasma and hydrogen peroxide aerosol present a possible alternative method of microbial decontamination of food, food packages or other thermolabile materials.

  8. In vivo levels of mitochondrial hydrogen peroxide increase with age in mtDNA mutator mice.

    PubMed

    Logan, Angela; Shabalina, Irina G; Prime, Tracy A; Rogatti, Sebastian; Kalinovich, Anastasia V; Hartley, Richard C; Budd, Ralph C; Cannon, Barbara; Murphy, Michael P

    2014-08-01

    In mtDNA mutator mice, mtDNA mutations accumulate leading to a rapidly aging phenotype. However, there is little evidence of oxidative damage to tissues, and when analyzed ex vivo, no change in production of the reactive oxygen species (ROS) superoxide and hydrogen peroxide by mitochondria has been reported, undermining the mitochondrial oxidative damage theory of aging. Paradoxically, interventions that decrease mitochondrial ROS levels in vivo delay onset of aging. To reconcile these findings, we used the mitochondria-targeted mass spectrometry probe MitoB to measure hydrogen peroxide within mitochondria of living mice. Mitochondrial hydrogen peroxide was the same in young mutator and control mice, but as the mutator mice aged, hydrogen peroxide increased. This suggests that the prolonged presence of mtDNA mutations in vivo increases hydrogen peroxide that contributes to an accelerated aging phenotype, perhaps through the activation of pro-apoptotic and pro-inflammatory redox signaling pathways.

  9. Spatially-resolved intracellular sensing of hydrogen peroxide in living cells.

    PubMed

    Warren, Emilie A K; Netterfield, Tatiana S; Sarkar, Saheli; Kemp, Melissa L; Payne, Christine K

    2015-11-20

    Understanding intracellular redox chemistry requires new tools for the site-specific visualization of intracellular oxidation. We have developed a spatially-resolved intracellular sensor of hydrogen peroxide, HyPer-Tau, for time-resolved imaging in live cells. This sensor consists of a hydrogen peroxide-sensing protein tethered to microtubules. We demonstrate the use of the HyPer-Tau sensor for three applications; dose-dependent response of human cells to exogenous hydrogen peroxide, a model immune response of mouse macrophages to stimulation by bacterial toxin, and a spatially-resolved response to localized delivery of hydrogen peroxide. These results demonstrate that HyPer-Tau can be used as an effective tool for tracking changes in spatially localized intracellular hydrogen peroxide and for future applications in redox signaling.

  10. Role of OGG1 and NTG2 in the repair of oxidative DNA damage and mutagenesis induced by hydrogen peroxide in Saccharomyces cerevisiae: relationships with transition metals iron and copper.

    PubMed

    Melo, R G M; Leitão, A C; Pádula, M

    2004-09-01

    The base excision repair pathway of Saccharomyces cerevisiae possesses three DNA N-glycosylases, viz. Ogg1p, Ngt1p and Ntg2p, involved in the repair of oxidative DNA damage. It was previously reported that inactivation of any of these activities, in most cases, did not generate a sensitive mutant phenotype to a variety of oxidative agents. Only the ntg1 mutant appeared to be more sensitive to hydrogen peroxide (H2O2) than a wild-type (WT) strain. In the present study we evaluated the role of S. cerevisiae OGG1 and NTG2 genes in the repair of oxidative lesions induced by high H2O2 concentrations (5-100 mM for 20 min), followed by catalase treatment (500 IU/ml). In these conditions, the ogg1 mutant was more sensitive than the WT strain to H2O2 (concentration 40-60 mM). Unexpectedly, the inactivation of NTG2 in an ogg1 background was able to suppress both sensitivity and mutagenesis induced by H2O2. Indeed, even the ntg2 single mutant was more resistant than the WT (60-100 mM H2O2). The use of metal ion chelators dipyridyl and neocuproine allowed us to evaluate the participation of iron and copper ions in the production of lethal and mutagenic lesions during H2O2 treatment in different DNA repair-deficient S. cerevisiae strains. The roles of OGG1 and NTG2 genes in the repair of lethal and mutagenic oxidative lesions induced by H2O2 and their relationships with iron and copper ions are discussed.

  11. Fluorescence ratiometric sensor for trace vapor detection of hydrogen peroxide.

    PubMed

    Xu, Miao; Han, Ji-Min; Wang, Chen; Yang, Xiaomei; Pei, Jian; Zang, Ling

    2014-06-11

    Trace vapor detection of hydrogen peroxide (H2O2) represents a practical approach to nondestructive detection of peroxide-based explosives, including liquid mixtures of H2O2 and fuels and energetic peroxide derivatives, such as triacetone triperoxide (TATP), diacetone diperoxide (DADP), and hexamethylene triperoxide diamine (HMTD). Development of a simple chemical sensor system that responds to H2O2 vapor with high reliability and sufficient sensitivity (reactivity) remains a challenge. We report a fluorescence ratiometric sensor molecule, diethyl 2,5-bis((((4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzyl)oxy)carbonyl)amino)terephthalate (DAT-B), for H2O2 that can be fabricated into an expedient, reliable, and sensitive sensor system suitable for trace vapor detection of H2O2. DAT-B is fluorescent in the blue region, with an emission maximum at 500 nm in the solid state. Upon reaction with H2O2, DAT-B is converted to an electronic "push-pull" structure, diethyl 2,5-diaminoterephthalate (DAT-N), which has an emission peak at a longer wavelength centered at 574 nm. Such H2O2-mediated oxidation of aryl boronates can be accelerated through the addition of an organic base such as tetrabutylammonium hydroxide (TBAH), resulting in a response time of less than 0.5 s under 1 ppm of H2O2 vapor. The strong overlap between the absorption band of DAT-N and the emission band of DAT-B enables efficient Förster resonance energy transfer (FRET), thus allowing further enhancement of the sensing efficiency of H2O2 vapor. The detection limit of a drop-cast DAT-B/TBAH film was projected to be 7.7 ppb. By combining high sensitivity and selectivity, the reported sensor system may find broad application in vapor detection of peroxide-based explosives and relevant chemical reagents through its fabrication into easy-to-use, cost-effective kits. PMID:24801730

  12. Overoxidation of chloroplast 2-Cys peroxiredoxins: balancing toxic and signaling activities of hydrogen peroxide

    PubMed Central

    Puerto-Galán, Leonor; Pérez-Ruiz, Juan M.; Ferrández, Julia; Cano, Beatriz; Naranjo, Belén; Nájera, Victoria A.; González, Maricruz; Lindahl, Anna M.; Cejudo, Francisco J.

    2013-01-01

    Photosynthesis, the primary source of biomass and oxygen into the biosphere, involves the transport of electrons in the presence of oxygen and, therefore, chloroplasts constitute an important source of reactive oxygen species, including hydrogen peroxide. If accumulated at high level, hydrogen peroxide may exert a toxic effect; however, it is as well an important second messenger. In order to balance the toxic and signaling activities of hydrogen peroxide its level has to be tightly controlled. To this end, chloroplasts are equipped with different antioxidant systems such as 2-Cys peroxiredoxins (2-Cys Prxs), thiol-based peroxidases able to reduce hydrogen and organic peroxides. At high peroxide concentrations the peroxidase function of 2-Cys Prxs may become inactivated through a process of overoxidation. This inactivation has been proposed to explain the signaling function of hydrogen peroxide in eukaryotes, whereas in prokaryotes, the 2-Cys Prxs of which were considered to be insensitive to overoxidation, the signaling activity of hydrogen peroxide is less relevant. Here we discuss the current knowledge about the mechanisms controlling 2-Cys Prx overoxidation in chloroplasts, organelles with an important signaling function in plants. Given the prokaryotic origin of chloroplasts, we discuss the occurrence of 2-Cys Prx overoxidation in cyanobacteria with the aim of identifying similarities between chloroplasts and their ancestors regarding their response to hydrogen peroxide. PMID:23967002

  13. Measurement of hydrogen peroxide in an advanced oxidation process using an automated biosensor.

    PubMed

    Modrzejewska, B; Guwy, A J; Dinsdale, R; Hawkes, D L

    2007-01-01

    A hydrogen peroxide biosensor was used to monitor hydrogen peroxide concentrations in a UV/hydrogen peroxide immobilised Fenton advanced oxidation process (AOP). The biosensor is based on gas phase monitoring and thus is more resistant to fouling from the liquid phase constituents of industrial processes. The biosensor is supplied with catalase continually, therefore overcoming any problems with enzyme degradation, which would occur in an immobilised enzyme biosensor. The biosensors response was linear within the experimental range 30-400mg H(2)O(2)l(-1) with a R(2) correlation of 0.99. The hydrogen peroxide monitor was used to monitor residual peroxide in an AOP, operated with a step overload of hydrogen peroxide, with correlation factors of 0.96-0.99 compared to offline hydrogen peroxide determinations by UV spectroscopy. Sparging the sample with nitrogen was found to be effective in reducing the interference from dissolved gases produced with the AOP itself. It is proposed that this biosensor could be used to improve the effectiveness of AOPs via hydrogen peroxide control.

  14. Overoxidation of chloroplast 2-Cys peroxiredoxins: balancing toxic and signaling activities of hydrogen peroxide.

    PubMed

    Puerto-Galán, Leonor; Pérez-Ruiz, Juan M; Ferrández, Julia; Cano, Beatriz; Naranjo, Belén; Nájera, Victoria A; González, Maricruz; Lindahl, Anna M; Cejudo, Francisco J

    2013-01-01

    Photosynthesis, the primary source of biomass and oxygen into the biosphere, involves the transport of electrons in the presence of oxygen and, therefore, chloroplasts constitute an important source of reactive oxygen species, including hydrogen peroxide. If accumulated at high level, hydrogen peroxide may exert a toxic effect; however, it is as well an important second messenger. In order to balance the toxic and signaling activities of hydrogen peroxide its level has to be tightly controlled. To this end, chloroplasts are equipped with different antioxidant systems such as 2-Cys peroxiredoxins (2-Cys Prxs), thiol-based peroxidases able to reduce hydrogen and organic peroxides. At high peroxide concentrations the peroxidase function of 2-Cys Prxs may become inactivated through a process of overoxidation. This inactivation has been proposed to explain the signaling function of hydrogen peroxide in eukaryotes, whereas in prokaryotes, the 2-Cys Prxs of which were considered to be insensitive to overoxidation, the signaling activity of hydrogen peroxide is less relevant. Here we discuss the current knowledge about the mechanisms controlling 2-Cys Prx overoxidation in chloroplasts, organelles with an important signaling function in plants. Given the prokaryotic origin of chloroplasts, we discuss the occurrence of 2-Cys Prx overoxidation in cyanobacteria with the aim of identifying similarities between chloroplasts and their ancestors regarding their response to hydrogen peroxide.

  15. Effect of carbamide peroxide and hydrogen peroxide on enamel surface: an in vitro study.

    PubMed

    Abouassi, Thaer; Wolkewitz, Martin; Hahn, Petra

    2011-10-01

    The aim of the study was to investigate changes in the micromorphologyl and microhardness of the enamel surface after bleaching with two different concentrations of hydrogen peroxide (HP) and carbamide peroxide (CP). Bovine enamel samples were embedded in resin blocks, and polished. Specimens in the experimental groups (n = 10) were treated with bleaching gels containing 10% CP, 35% CP, 3.6% HP, and 10% HP, respectively, for 2 h every second day over a period of 2 weeks. The gels had the identical composition and pH and differed only in their HP or CP content. The roughness and morphology of the enamel surface were analyzed using laser profilometry and SEM. Microhardness was measured using a Knoop hardness tester. The data were evaluated statistically. Specimens in the 10% HP group showed significantly higher roughness after bleaching compared to the control group (ΔRa, p = 0.01). Bleaching with 35% CP showed only a tendency to increase roughness (ΔRa, p = 0.06). Application of 10% CP or 3.6% HP had no significant influence on Ra. Enamel microhardness was significantly higher after application of 10% HP compared to the control (ΔMic = 8 KHN, p = 0.0002) and 35% CP (ΔMic = 20KHN, p = 0.01) groups. In summary, application of CP and HP showed only small quantitative and qualitative differences. In addition, the influence of bleaching procedure on the morphology and hardness of the enamel surface depended on the concentration of the active ingredients.

  16. Localization of hydrogen peroxide accumulation and diamine oxidase activity in pea root nodules under aluminum stress.

    PubMed

    Sujkowska-Rybkowska, Marzena; Borucki, Wojciech

    2014-02-01

    Aluminum (Al) is one of the environmental stressors that induces formation of reactive oxygen species (ROS) in plants. Hydrogen peroxide (H2O2) and H2O2-generated apoplast diamine oxidase (DAO) activity were detected cytochemically via transmission electron microscopy (TEM), in pea (Pisum sativum L.) root nodules exposed to high (50 μM AlCl3, for 2 and 24h) Al stress. The nodules were shown to respond to Al stress by disturbances in infection thread (IT) growth, bacteria endocytosis, premature degeneration of bacteroidal tissue and generation of H2O2 in nodule apoplast. Large amounts of peroxide were found at the same sites as high DAO activity under Al stress, suggesting that DAO is a major source of Al-induced peroxide accumulation in the nodules. Peroxide distribution and DAO activity in the nodules of both control plants and Al-treated ones were typically found in the plant cell walls, intercellular spaces and infection threads. However, 2 h Al treatment increased DAO activity and peroxide accumulation in the nodule apoplast and bacteria within threads. A prolonged Al treatment (24 h) increased the H2O2 content and DAO activity in the nodule apoplast, especially in the thread walls, matrix and bacteria within infection threads. In addition to ITs, prematurely degenerated bacteroids, which occurred in response to Al, were associated with intense staining for H2O2 and DAO activity. These results suggest the involvement of DAO in the production of a large amount of H2O2 in the nodule apoplast under Al stress. The role of reactive oxygen species in pea-Rhizobium symbiosis under Al stress is discussed. PMID:24246127

  17. Alpha-tocopherol modulates hydrogen peroxide-induced DNA damage and telomere shortening of human skin fibroblasts derived from differently aged individuals.

    PubMed

    Makpol, Suzana; Zainuddin, Azalina; Rahim, Norhazira Abdul; Yusof, Yasmin Anum; Ngah, Wan Zurinah

    2010-06-01

    Antioxidants such as vitamin E may act differently on skin cells depending on the age of the skin and the level of oxidative damage induced. The effects of alpha-tocopherol (ATF) on H(2)O(2)-induced DNA damage and telomere shortening of normal human skin fibroblast cells derived from young and old individual donors were determined. Fibroblasts were divided into five groups; untreated control, H(2)O(2)-induced oxidative stress, alpha-tocopherol treatment, and pre- and post-treatment with alpha-tocopherol for H(2)O(2)-induced oxidative stress. Our results showed that H(2)O(2)-induced oxidative stress increased DNA damage, shortened the telomere length and reduced the telomerase activity (p < 0.05) in fibroblasts obtained from young and old donors. Pre- and post-treatment with alpha-tocopherol protected against H(2)O(2)-induced DNA damage in fibroblasts obtained from young individuals (p = 0.005; p = 0.01, respectively). However, in fibroblasts obtained from old individuals, similar protective effects were only seen in cells pretreated with alpha-tocopherol (p = 0.05) but not in the post-treated cells. Protection against H(2)O(2)-induced telomere shortening was observed in fibroblasts obtained from both young and old donors which were pre-treated with alpha-tocopherol (p = 0.009; p = 0.008, respectively). However, similar protective effects against telomere shortening in fibroblasts obtained from both young and old donors were not observed in the post-treated fibroblasts. Protection against H(2)O(2)-induced telomerase activity loss was observed only in fibroblasts obtained from old donors which were pretreated with alpha-tocopherol (p = 0.04) but not in fibroblasts obtained from young donors. Similar protective effects against telomerase activity loss in fibroblasts obtained from both young and old donors were not observed in the post-treated fibroblasts. In conclusion, alpha-tocopherol protected against H(2)O(2)-induced telomere shortening by restoring the telomerase

  18. Hydrogen peroxide inhibits transforming growth factor-β1-induced cell cycle arrest by promoting Smad3 linker phosphorylation through activation of Akt-ERK1/2-linked signaling pathway.

    PubMed

    Choi, Jiyeon; Park, Seong Ji; Jo, Eun Ji; Lee, Hui-Young; Hong, Suntaek; Kim, Seong-Jin; Kim, Byung-Chul

    2013-06-14

    Hydrogen peroxide (H2O2) functions as a second messenger in growth factor receptor-mediated intracellular signaling cascade and is tumorigenic by virtue of its ability to promote cell proliferation; however, the mechanisms underlying the growth stimulatory action of H2O2 are less understood. Here we report an important mechanism for antagonistic effects of H2O2 on growth inhibitory response to transforming growth factor-β1 (TGF-β1). In Mv1Lu and HepG2 cells, pretreatment of H2O2 (0.05-0.2 mM) completely blocked TGF-β1-mediated induction of p15(INK4B) expression and increase of its promoter activity. Interestingly, H2O2 selectively suppressed the transcriptional activation potential of Smad3, not Smad2, in the absence of effects on TGF-β1-induced phosphorylation of the COOH-tail SSXS motif of Smad3 and its nuclear translocation. Mechanism studies showed that H2O2 increases the phosphorylation of Smad3 at the middle linker region in a concentration- and time-dependent manner and this effect is mediated by activation of extracellular signal-activated kinase 1/2 through Akt. Furthermore, expression of a mutant Smad3 in which linker phosphorylation sites were ablated significantly abrogated the inhibitory effects of H2O2 on TGF-β1-induced increase of p15(INK4B)-Luc reporter activity and blockade of cell cycle progression from G1 to S phase. These findi