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Sample records for hydrogen peroxide induced

  1. Hydrogen peroxide-induced apoptosis in human gingival fibroblasts.

    PubMed

    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.

  2. 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

  3. Hydrogen peroxide poisoning

    MedlinePlus

    Hydrogen peroxide is used in these products: Hydrogen peroxide Hair bleach Some contact lens cleaners Note: Household hydrogen peroxide has a 3% concentration. That means it contains 97% water and 3% hydrogen peroxide. Hair ...

  4. 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.

  5. Mechanisms of hydrogen peroxide-induced contraction of rat aorta.

    PubMed

    Yang, Z W; Zheng, T; Zhang, A; Altura, B T; Altura, B M

    1998-03-05

    It has been suggested that reactive oxygen species may be involved in the regulation of vascular tone. However, the underlying mechanisms remain to be elucidated. The present studies were designed to investigate the contractile effects of hydrogen peroxide (H2O2), one of the reactive oxygen species, on isolated ring segments of rat aorta with and without endothelium. H2O2 induced an endothelium-independent contraction in isolated rat aorta ring segments in a concentration-dependent manner at concentrations from 5 x 10(-6) to 5 x 10(-3) M. H2O2-induced contractions of denuded rat aorta rings were stronger than those on intact rat aorta segments. The contractile effects of H2O2 were inhibited completely by 1200 u/ml catalase. The presence of 1.0 microM Fe2+ or 10 microM proadifen, a cytochrome P450 monooxygenase inhibitor, potentiated the contractile effect of H2O2 on isolated rat aorta segments. 1 mM deferoxamine (a Fe2+ chelator) or 100 microM dimethyl sulfoxide (a hydroxyl radical scavenger) significantly attenuated the vessel contractions induced by hydrogen peroxide plus Fe2+ or hydrogen peroxide itself. Removal of extracellular Ca2+ ([Ca2+]0), addition of 5 microM verapamil, administration of a protein kinase C inhibitor (staurosporine), treatment with an inhibitor of protein tyrosine phosphorylation (genistein) or employment of 5.0 microM indomethacin resulted in a significant attenuation of the contractile responses of the vessels to H2O2. Pharmacological antagonists (e.g. a muscarinic acetylcholine receptor antagonist (atropine), an antagonist of histamine H1 receptors (diphenhydramine), an antagonist of histamine H2 receptors (cimetidine), an alpha-adrenoceptor antagonist (phentolamine), a beta-adrenoceptor antagonist (propranolol) and an antagonist of serotonin receptor (methysergide)) did not inhibit or attenuate the contractions induced by H2O2. Exposure of primary aortic smooth muscle cells to H2O2 (5 x 10(-6) to 5 x 10(-3) M) produced significant rises

  6. 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.

  7. 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.

  8. 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.

  9. Pyruvate protects neurons against hydrogen peroxide-induced toxicity.

    PubMed

    Desagher, S; Glowinski, J; Prémont, J

    1997-12-01

    Hydrogen peroxide (H2O2) is suspected to be involved in numerous brain pathologies such as neurodegenerative diseases or in acute injury such as ischemia or trauma. In this study, we examined the ability of pyruvate to improve the survival of cultured striatal neurons exposed for 30 min to H2O2, as estimated 24 hr later by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazoliumbromide assay. Pyruvate strongly protected neurons against both H2O2 added to the external medium and H2O2 endogenously produced through the redox cycling of the experimental quinone menadione. The neuroprotective effect of pyruvate appeared to result rather from the ability of alpha-ketoacids to undergo nonenzymatic decarboxylation in the presence of H2O2 than from an improvement of energy metabolism. Indeed, several other alpha-ketoacids, including alpha-ketobutyrate, which is not an energy substrate, reproduced the neuroprotective effect of pyruvate. In contrast, lactate, a neuronal energy substrate, did not protect neurons from H2O2. Optimal neuroprotection was achieved with relatively low concentrations of pyruvate (induced by the cotransport of pyruvate and protons into neurons. Indeed, cytosolic acidification both enhanced the H2O2-induced neurotoxicity and decreased the rate of pyruvate decarboxylation by H2O2. Together, these results indicate that pyruvate efficiently protects neurons against both exogenous and endogenous H2O2. Its low toxicity and its capacity to cross the blood-brain barrier open a new therapeutic perspective in brain pathologies in which H2O2 is involved.

  10. Lipid peroxidation induced by indomethacin with horseradish peroxidase and hydrogen peroxide: involvement of indomethacin radicals.

    PubMed

    Miura, Toshiaki; Muraoka, Sanae; Fujimoto, Yukio

    2002-06-01

    Some of the side-effects of using indomethacin (IM) involve damage to the gastric mucosa and liver mitochondria. On the other hand, neutrophils infiltrate inflammatory sites to damage the tissues through the generation of reactive oxygen species by myeloperoxidase. The stomach and intestine have large amounts of peroxidase. These findings suggest that peroxidases are involved in tissue damage induced by IM. To clarify the basis for the tissue damage induced by IM in the presence of horseradish peroxidase (HRP) and H2O2 (HRP-H2O2), lipid peroxidation was investigated. When IM was incubated with liver microsomes in the presence of HRP-H2O2 and ADP-Fe3+, lipid peroxidation was time-dependent. Catalase and desferrioxamine almost completely inhibited lipid peroxidation, indicating that H2O2 and iron are necessary for lipid peroxidation. Of interest, superoxide dismutase strongly inhibited lipid peroxidation, and it also inhibited the formation of bathophenanthroline-Fe2+, indicating that reduction of the ferric ion was due to superoxide (O2-). ESR signals of IM radicals were detected during the interaction of IM with HRP-H2O2. However, the IM radical by itself did not reduce the ferric ion. These results suggest that O2- may be generated during the interaction of IM radicals with H2O2. Ferryl species, which are formed during the reduction of iron by O2-, probably are involved in lipid peroxidation.

  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. Role of high-energy phosphate metabolism in hydrogen peroxide-induced cardiac dysfunction.

    PubMed

    Matsumoto, Y; Kaneko, M; Iimuro, M; Fujise, Y; Hayashi, H

    2000-01-01

    This study was undertaken to clarify the role of high-energy phosphate metabolism in hydrogen peroxide-induced cardiac dysfunction using phosphorus and fluorine nuclear magnetic resonance spectroscopy. The exposure of a Langendorff-perfused heart to hydrogen peroxide (200-400 micromol/L, 8 min) provoked biphasic contractile dysfunction characterized by a transient depression of left ventricular developed pressure during the administration of hydrogen peroxide and a delayed elevation of left ventricular end-diastolic pressure after the washout of hydrogen peroxide. The initial phase of cardiac dysfunction correlated well with the accumulation of sugar phosphates (r = 0.89, p < 0.01). Furthermore, we demonstrated that glibenclamide, a potent inhibitor of the ATP-sensitive K+ channel, attenuated the initial depression of developed pressure. On the other hand, the delayed elevation of end-diastolic pressure correlated well with the total ATP depletion (r = 0.96, p < 0.01). However, ATP loss was supposed to be a mere result from the increased ATP consumption corresponding to a rise in intracellular free Ca2+ (from the control value of 315+/-23 nmol/L to 708+/-104 after the administration of hydrogen peroxide, p < 0.01), which also paralleled the elevation of end-diastolic pressure. Thus glycolytic inhibition and intracellular Ca2+ overload are independently responsible for the biphasic contractile dysfunction induced by hydrogen peroxide.

  13. Tolerance of pentose utilising yeast to hydrogen peroxide-induced oxidative stress

    PubMed Central

    2014-01-01

    Background Bioethanol fermentations follow traditional beverage fermentations where the yeast is exposed to adverse conditions such as oxidative stress. Lignocellulosic bioethanol fermentations involve the conversion of pentose and hexose sugars into ethanol. Environmental stress conditions such as osmotic stress and ethanol stress may affect the fermentation performance; however, oxidative stress as a consequence of metabolic output can also occur. However, the effect of oxidative stress on yeast with pentose utilising capabilities has yet to be investigated. Results Assaying for the effect of hydrogen peroxide-induced oxidative stress on Candida, Pichia and Scheffersomyces spp. has demonstrated that these yeast tolerate hydrogen peroxide-induced oxidative stress in a manner consistent with that demonstrated by Saccharomyces cerevisiae. Pichia guillermondii appears to be more tolerant to hydrogen peroxide-induced oxidative stress when compared to Candida shehatae, Candida succiphila or Scheffersomyces stipitis. Conclusions Sensitivity to hydrogen peroxide-induced oxidative stress increased in the presence of minimal media; however, addition of amino acids and nucleobases was observed to increase tolerance. In particular adenine increased tolerance and methionine reduced tolerance to hydrogen peroxide-induced oxidative stress. PMID:24636079

  14. Hydrogen peroxide induced loss of heterozygosity correlates with replicative lifespan and mitotic asymmetry in Saccharomyces cerevisiae.

    PubMed

    Güven, Emine; Parnell, Lindsay A; Jackson, Erin D; Parker, Meighan C; Gupta, Nilin; Rodrigues, Jenny; Qin, Hong

    2016-01-01

    Cellular aging in Saccharomyces cerevisiae can lead to genomic instability and impaired mitotic asymmetry. To investigate the role of oxidative stress in cellular aging, we examined the effect of exogenous hydrogen peroxide on genomic instability and mitotic asymmetry in a collection of yeast strains with diverse backgrounds. We treated yeast cells with hydrogen peroxide and monitored the changes of viability and the frequencies of loss of heterozygosity (LOH) in response to hydrogen peroxide doses. The mid-transition points of viability and LOH were quantified using sigmoid mathematical functions. We found that the increase of hydrogen peroxide dependent genomic instability often occurs before a drop in viability. We previously observed that elevation of genomic instability generally lags behind the drop in viability during chronological aging. Hence, onset of genomic instability induced by exogenous hydrogen peroxide treatment is opposite to that induced by endogenous oxidative stress during chronological aging, with regards to the midpoint of viability. This contrast argues that the effect of endogenous oxidative stress on genome integrity is well suppressed up to the dying-off phase during chronological aging. We found that the leadoff of exogenous hydrogen peroxide induced genomic instability to viability significantly correlated with replicative lifespan (RLS), indicating that yeast cells' ability to counter oxidative stress contributes to their replicative longevity. Surprisingly, this leadoff is positively correlated with an inverse measure of endogenous mitotic asymmetry, indicating a trade-off between mitotic asymmetry and cell's ability to fend off hydrogen peroxide induced oxidative stress. Overall, our results demonstrate strong associations of oxidative stress to genomic instability and mitotic asymmetry at the population level of budding yeast.

  15. Hydrogen peroxide induced loss of heterozygosity correlates with replicative lifespan and mitotic asymmetry in Saccharomyces cerevisiae

    PubMed Central

    Jackson, Erin D.; Parker, Meighan C.; Gupta, Nilin; Rodrigues, Jenny

    2016-01-01

    Cellular aging in Saccharomyces cerevisiae can lead to genomic instability and impaired mitotic asymmetry. To investigate the role of oxidative stress in cellular aging, we examined the effect of exogenous hydrogen peroxide on genomic instability and mitotic asymmetry in a collection of yeast strains with diverse backgrounds. We treated yeast cells with hydrogen peroxide and monitored the changes of viability and the frequencies of loss of heterozygosity (LOH) in response to hydrogen peroxide doses. The mid-transition points of viability and LOH were quantified using sigmoid mathematical functions. We found that the increase of hydrogen peroxide dependent genomic instability often occurs before a drop in viability. We previously observed that elevation of genomic instability generally lags behind the drop in viability during chronological aging. Hence, onset of genomic instability induced by exogenous hydrogen peroxide treatment is opposite to that induced by endogenous oxidative stress during chronological aging, with regards to the midpoint of viability. This contrast argues that the effect of endogenous oxidative stress on genome integrity is well suppressed up to the dying-off phase during chronological aging. We found that the leadoff of exogenous hydrogen peroxide induced genomic instability to viability significantly correlated with replicative lifespan (RLS), indicating that yeast cells’ ability to counter oxidative stress contributes to their replicative longevity. Surprisingly, this leadoff is positively correlated with an inverse measure of endogenous mitotic asymmetry, indicating a trade-off between mitotic asymmetry and cell’s ability to fend off hydrogen peroxide induced oxidative stress. Overall, our results demonstrate strong associations of oxidative stress to genomic instability and mitotic asymmetry at the population level of budding yeast. PMID:27833823

  16. 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.

  17. 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.

  18. 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.

  19. Lens Endogenous Peptide αA66-80 Generates Hydrogen Peroxide and Induces Cell Apoptosis.

    PubMed

    Raju, Murugesan; Santhoshkumar, Puttur; Sharma, K Krishna

    2017-02-01

    In previous studies, we reported the presence of a large number of low-molecular-weight (LMW) peptides in aged and cataract human lens tissues. Among the LMW peptides, a peptide derived from αA-crystallin, αA66-80, was found in higher concentration in aged and cataract lenses. Additional characterization of the αA66-80 peptide showed beta sheet signature, and it formed well-defined unbranched fibrils. Further experimental data showed that αA66-80 peptide binds α-crystallin, impairs its chaperone function, and attracts additional crystallin proteins to the peptide α-crystallin complex, leading to the formation of larger light scattering aggregates. It is well established that Aβ peptide exhibits cell toxicity by the generation of hydrogen peroxide. The αA66-80 peptide shares the principal properties of Aβ peptide. Therefore, the present study was undertaken to determine whether the fibril-forming peptide αA66-80 has the ability to generate hydrogen peroxide. The results show that the αA66-80 peptide generates hydrogen peroxide, in the amount of 1.2 nM H2O2 per µg of αA66-80 peptide by incubation at 37°C for 4h. We also observed cytotoxicity and apoptotic cell death in αA66-80 peptide-transduced Cos7 cells. As evident, we found more TUNEL-positive cells in αA66-80 peptide transduced Cos7 cells than in control cells, suggesting peptide-mediated cell apoptosis. Additional immunohistochemistry analysis showed the active form of caspase-3, suggesting activation of the caspase-dependent pathway during peptide-induced cell apoptosis. These results confirm that the αA66-80 peptide generates hydrogen peroxide and promotes hydrogen peroxide-mediated cell apoptosis.

  20. Lens Endogenous Peptide αA66-80 Generates Hydrogen Peroxide and Induces Cell Apoptosis

    PubMed Central

    Raju, Murugesan; Santhoshkumar, Puttur; Sharma, K. Krishna

    2017-01-01

    In previous studies, we reported the presence of a large number of low-molecular-weight (LMW) peptides in aged and cataract human lens tissues. Among the LMW peptides, a peptide derived from αA-crystallin, αA66-80, was found in higher concentration in aged and cataract lenses. Additional characterization of the αA66-80 peptide showed beta sheet signature, and it formed well-defined unbranched fibrils. Further experimental data showed that αA66-80 peptide binds α-crystallin, impairs its chaperone function, and attracts additional crystallin proteins to the peptide α-crystallin complex, leading to the formation of larger light scattering aggregates. It is well established that Aβ peptide exhibits cell toxicity by the generation of hydrogen peroxide. The αA66-80 peptide shares the principal properties of Aβ peptide. Therefore, the present study was undertaken to determine whether the fibril-forming peptide αA66-80 has the ability to generate hydrogen peroxide. The results show that the αA66-80 peptide generates hydrogen peroxide, in the amount of 1.2 nM H2O2 per µg of αA66-80 peptide by incubation at 37°C for 4h. We also observed cytotoxicity and apoptotic cell death in αA66-80 peptide-transduced Cos7 cells. As evident, we found more TUNEL-positive cells in αA66-80 peptide transduced Cos7 cells than in control cells, suggesting peptide-mediated cell apoptosis. Additional immunohistochemistry analysis showed the active form of caspase-3, suggesting activation of the caspase-dependent pathway during peptide-induced cell apoptosis. These results confirm that the αA66-80 peptide generates hydrogen peroxide and promotes hydrogen peroxide-mediated cell apoptosis. PMID:28203481

  1. Hydrogen peroxide-induced renal injury. A protective role for pyruvate in vitro and in vivo.

    PubMed Central

    Salahudeen, A K; Clark, E C; Nath, K A

    1991-01-01

    Hydrogen peroxide (H2O2) contributes to renal cellular injury. alpha-Keto acids nonenzymatically reduce H2O2 to water while undergoing decarboxylation at the 1-carbon (1-C) position. We examined, in vitro and in vivo, the protective role of sodium pyruvate in H2O2-induced renal injury. Pyruvate effectively scavenged H2O2 in vitro, and suppressed H2O2-induced renal lipid peroxidation. Injury to LLC-PK1 cells induced by hydrogen peroxide was attenuated by pyruvate to an extent comparable to that seen with catalase. Studies utilizing [1-14C]pyruvate further demonstrated 1-C decarboxylation concurrent with cytoprotection by pyruvate from H2O2-induced injury. Pyruvate was also protective in vivo. Infusion of pyruvate before and during the intrarenal infusion of H2O2 attenuated H2O2-induced proteinuria. Systemic administration of pyruvate was also protective in the glycerol model of acute renal failure, a model also characterized by increased generation of H2O2. These findings indicate that pyruvate, a ubiquitous alpha-keto acid, scavenges H2O2 and protects renal tissue in vitro and in vivo from H2O2-mediated injury. These data suggest a potential therapeutic role for pyruvate in diseases in which increased generation of H2O2 is incriminated in renal damage. Images PMID:1752950

  2. Hydrogen peroxide centrally attenuates hyperosmolarity-induced thirst and natriuresis.

    PubMed

    Zanella, Regis C; Melo, Mariana Rosso; Furuya, Werner Issao; Colombari, Eduardo; Menani, José V; Colombari, Débora Simões Almeida

    2016-01-01

    Intragastric hypertonic NaCl that simulates the ingestion of osmotically active substances by food intake induces thirst, vasopressin and oxytocin release, diuresis and natriuresis. Reactive oxygen species (ROS) produced endogenously in central areas may act modulating autonomic and behavioral responses. In the present study, we investigated the effects of H2O2 injected centrally on water intake and renal responses induced by increasing plasma osmolality with intragastric (ig) administration of 2M NaCl (2 ml/rat). Male Holtzman rats (280-320 g) with stainless steel cannula implanted in the lateral ventricle (LV) were used. Injections of H2O2 (2.5 μmol/1 μl) into the LV reduced ig 2M NaCl-induced water intake (3.1 ± 0.7, vs. PBS: 8.6 ± 1.0 ml/60 min, p<0.05), natriuresis (769 ± 93, vs. PBS: 1158 ± 168 μEq/120 min, p<0.05) and diuresis (4.1 ± 0.5, vs. PBS: 5.0 ± 0.5 ml/120 min, p<0.05). Injections of H2O2 into the LV also decreased meal associated water intake (4.9 ± 1.5, vs. PBS: 11.0 ± 1.7 ml/120 min). However, H2O2 into the LV did not modify 2% sucrose intake (3.3 ± 1.5, vs. PBS: 5.4 ± 2.3 ml/120 min) or 24h food deprivation-induced food intake (8.2 ± 2.0, vs. PBS: 11.0 ± 1.6g/120 min), suggesting that this treatment does not produce nonspecific inhibition of ingestive behaviors. The data suggest an inhibitory role for H2O2 acting centrally on thirst and natriuresis induced by hyperosmolarity and on meal-associated thirst.

  3. 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.

  4. Hydrogen peroxide-induced structural alterations of RNAse A.

    PubMed

    Lasch, P; Petras, T; Ullrich, O; Backmann, J; Naumann, D; Grune, T

    2001-03-23

    Proteins exposed to oxidative stress are degraded via proteolytic pathways. In the present study, we undertook a series of in vitro experiments to establish a correlation between the structural changes induced by mild oxidation of the model protein RNase A and the proteolytic rate found upon exposure of the modified protein toward the isolated 20 S proteasome. Fourier transform infrared spectroscopy was used as a structure-sensitive probe. We report here strong experimental evidence for oxidation-induced conformational rearrangements of the model protein RNase A and, at the same time, for covalent modifications of amino acid side chains. Oxidation-related conformational changes, induced by H(2)O(2) exposure of the protein may be monitored in the amide I region, which is sensitive to changes in protein secondary structure. A comparison of the time- and H(2)O(2) concentration-dependent changes in the amide I region demonstrates a high degree of similarity to spectral alterations typical for temperature-induced unfolding of RNase A. In addition, spectral parameters of amino acid side chain marker bands (Tyr, Asp) revealed evidence for covalent modifications. Proteasome digestion measurements on oxidized RNase A revealed a specific time and H(2)O(2) concentration dependence; at low initial concentration of the oxidant, the RNase A turnover rate increases with incubation time and concentration. Based on these experimental findings, a correlation between structural alterations detected upon RNase A oxidation and proteolytic rates of RNase A is established, and possible mechanisms of the proteasome recognition process of oxidatively damaged proteins are discussed.

  5. Probiotics ameliorate the hydrogen peroxide-induced epithelial barrier disruption by a PKC- and MAP kinase-dependent mechanism

    PubMed Central

    Seth, A.; Yan, Fang; Polk, D.Brent; Rao, R. K.

    2009-01-01

    Probiotics promote intestinal epithelial integrity and reduce infection and diarrhea. We evaluated the effect of Lactobacillus rhamnosus GG-produced soluble proteins (p40 and p75) on the hydrogen peroxide-induced disruption of tight junctions and barrier function in Caco-2 cell monolayers. Pretreatment of cell monolayers with p40 or p75 attenuated the hydrogen peroxide-induced decrease in transepithelial resistance and increase in inulin permeability in a time- and dose-dependent manner. p40 and p75 also prevented hydrogen peroxide-induced redistribution of occludin, ZO-1, E-cadherin, and β-catenin from the intercellular junctions and their dissociation from the detergent-insoluble fractions. Both p40 and p75 induced a rapid increase in the membrane translocation of PKCβI and PKCε. The attenuation of hydrogen peroxide-induced inulin permeability and redistribution of tight junction proteins by p40 and p75 was abrogated by Ro-32-0432, a PKC inhibitor. p40 and p75 also rapidly increased the levels of phospho-ERK1/2 in the detergent-insoluble fractions. U0126 (a MAP kinase inhibitor) attenuated the p40- and p75-mediated reduction of hydrogen peroxide-induced tight junction disruption and inulin permeability. These studies demonstrate that probiotic-secretory proteins protect the intestinal epithelial tight junctions and the barrier function from hydrogen peroxide-induced insult by a PKC- and MAP kinase-dependent mechanism. PMID:18292183

  6. Probiotics ameliorate the hydrogen peroxide-induced epithelial barrier disruption by a PKC- and MAP kinase-dependent mechanism.

    PubMed

    Seth, A; Yan, Fang; Polk, D Brent; Rao, R K

    2008-04-01

    Probiotics promote intestinal epithelial integrity and reduce infection and diarrhea. We evaluated the effect of Lactobacillus rhamnosus GG-produced soluble proteins (p40 and p75) on the hydrogen peroxide-induced disruption of tight junctions and barrier function in Caco-2 cell monolayers. Pretreatment of cell monolayers with p40 or p75 attenuated the hydrogen peroxide-induced decrease in transepithelial resistance and increase in inulin permeability in a time- and dose-dependent manner. p40 and p75 also prevented hydrogen peroxide-induced redistribution of occludin, ZO-1, E-cadherin, and beta-catenin from the intercellular junctions and their dissociation from the detergent-insoluble fractions. Both p40 and p75 induced a rapid increase in the membrane translocation of PKCbetaI and PKCepsilon. The attenuation of hydrogen peroxide-induced inulin permeability and redistribution of tight junction proteins by p40 and p75 was abrogated by Ro-32-0432, a PKC inhibitor. p40 and p75 also rapidly increased the levels of phospho-ERK1/2 in the detergent-insoluble fractions. U0126 (a MAP kinase inhibitor) attenuated the p40- and p75-mediated reduction of hydrogen peroxide-induced tight junction disruption and inulin permeability. These studies demonstrate that probiotic-secretory proteins protect the intestinal epithelial tight junctions and the barrier function from hydrogen peroxide-induced insult by a PKC- and MAP kinase-dependent mechanism.

  7. 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

  8. In vitro curcumin modulates ferric nitrilotriacetate (Fe-NTA) and hydrogen peroxide (H2O2)-induced peroxidation of microsomal membrane lipids and DNA damage.

    PubMed

    Iqbal, Mohammad; Okazaki, Yasumasa; Okada, Shigeru

    2003-01-01

    A number of investigations have implicated the involvement of free radicals in various pathogenic process including initiation/promotion stages of carcinogenesis and antioxidants have been considered to be a protective agent for this reason. An iron chelate, ferric nitrilotriacetate (Fe-NTA), is a potent nephrotoxic agent and induces acute and subacute renal proximal tubular necrosis by catalyzing the decomposition of hydrogen peroxide-derived production of hydroxyl radicals, which are known to cause lipid peroxidation and DNA damage. The latter is associated with a high incidence of renal adenocarcinoma in rodents. Lipid peroxidation and DNA damage are the principal manifestation of Fe-NTA-induced toxicity, which could be mitigated by antioxidants. In this study, we therefore investigated the effect of curcumin, a polyphenolic compound from Curcuma longa for a possible protection against lipid peroxidation and DNA damage induced by Fe-NTA and hydrogen peroxide in vitro. Incubation of renal microsomal membrane/and or calf thymus DNA with hydrogen peroxide (40 mM) in the presence of Fe-NTA (0.1 mM) induces renal microsomal lipid peroxidation and DNA damage to about 2.2-and 5.6-fold, respectively, as compared to saline treated control (P<0.001). Induction of renal microsomal lipid peroxidation and DNA damage was modulated by curcumin dose dependently. In lipid peroxidation protection studies, curcumin treatment showed a dose-dependent strong inhibition (18-80% inhibition, P<0.05-0.001) of Fe-NTA and hydrogen peroxide-induced lipid peroxidation as measured by MDA formation in renal microsomes. Similarly, in DNA-sugar damage protection studies, curcumin treatment also showed a dose dependent inhibition (22-57% inhibition, P<0.05-0.001) of DNA-sugar damage. From these studies, it was concluded that curcumin modulates Fe-NTA and hydrogen peroxide-induced peroxidation of microsomal membrane lipids and DNA damage. Curcumin might, therefore, be a suitable candidate for the

  9. Inhibition of hydrogen peroxide induced injuring on human skin fibroblast by Ulva prolifera polysaccharide.

    PubMed

    Cai, Chuner; Guo, Ziye; Yang, Yayun; Geng, Zhonglei; Tang, Langlang; Zhao, Minglin; Qiu, Yuyan; Chen, Yifan; He, Peimin

    2016-10-01

    Ulva prolifera can protect human skin fibroblast from being injured by hydrogen peroxide. This work studied the composition of Ulva prolifera polysaccharide and identified its physicochemical properties. The results showed that the cell proliferation of 0.5mg/mL crude polysaccharide was 154.4% of that in negative control group. Moreover, ROS detection indices, including DCFH-DA, GSH-PX, MDA and CAT, indicated that crude polysaccharide could improve cellular ability to scavenge free radical and decrease the injury on human skin fibroblast by hydrogen peroxide. In purified polysaccharide, the activity of fraction P1-1 was the highest, with 174.6% of that in negative control group. The average molecular weight of P1-1 was 137kD with 18.0% of sulfate content. This work showed the inhibition of hydrogen peroxide induced injuries on human skin fibroblast by Ulva prolifera polysaccharide, which may further evaluate the application of U. prolifera on cosmetics.

  10. Gardenia jasminoides extract-capped gold nanoparticles reverse hydrogen peroxide-induced premature senescence.

    PubMed

    Chae, Seon Yeong; Park, Sun Young; Park, Jin Oh; Lee, Kyu Jin; Park, Geuntae

    2016-11-01

    This study reports a green approach for synthesis of gold nanoparticles using Gardenia jasminoides extract, and specifically, can potentially enhance anti senescence activity. Biological synthesis of gold nanoparticles is ecofriendly and effective for the development of environmentally sustainable nanoparticles compared with existing methods. Here, we developed a simple, fast, efficient, and ecofriendly approach to the synthesis of gold nanoparticles by means of a Gardenia jasminoides extract. These G. jasminoides extract-capped gold nanoparticles (GJ-GNPs) were characterized by UV-vis, high resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), and Furrier transform infrared spectroscopy (FT-IR). The synthesized GJ-GNPs turned red and showed maximal absorbance at 540nm. Thus, GJ-GNPs were synthesized successfully. We hypothesized that GJ-GNPs would protect ARPE19 cells from hydrogen peroxide-induced premature senescence. SA-β-gal activity was elevated in hydrogen peroxide-treated cells, however, this effect was attenuated by GJ-GNP treatment. Moreover, compared with the normal control, hydrogen peroxide treatment significantly increased lysosome content of the cells and production of reactive oxygen species (ROS). GJ-GNPs effectively attenuated the increase in lysosome content and ROS production in these senescent cells. According to cell cycle analysis, G2/M arrest was promoted by hydrogen peroxide treatment in ARPE19 cells, however, this change was reversed by GJ-GNPs. Western blot analysis showed that treatment with GJ-GNPs increased the expression of p53, p21, SIRT3, HO-1, and NQO1 in senescent cells. Our findings should advance the understanding of premature senescence and may lead to therapeutic use of GJ-GNPs in retina-related regenerative medicine.

  11. Hydrogen-peroxide-induced heme degradation in red blood cells: the protective roles of catalase and glutathione peroxidase.

    PubMed

    Nagababu, Enika; Chrest, Francis J; Rifkind, Joseph M

    2003-03-17

    Catalase and glutathione peroxidase (GSHPX) react with red cell hydrogen peroxide. A number of recent studies indicate that catalase is the primary enzyme responsible for protecting the red cell from hydrogen peroxide. We have used flow cytometry in intact cells as a sensitive measure of the hydrogen-peroxide-induced formation of fluorescent heme degradation products. Using this method, we have been able to delineate a unique role for GSHPX in protecting the red cell from hydrogen peroxide. For extracellular hydrogen peroxide, catalase completely protected the cells, while the ability of GSHPX to protect the cells was limited by the availability of glutathione. The effect of endogenously generated hydrogen peroxide in conjunction with hemoglobin autoxidation was investigated by in vitro incubation studies. These studies indicate that fluorescent products are not formed during incubation unless the glutathione is reduced to at least 40% of its initial value as a result of incubation or by reacting the glutathione with iodoacetamide. Reactive catalase only slows down the depletion of glutathione, but does not directly prevent the formation of these fluorescent products. The unique role of GSHPX is attributed to its ability to react with hydrogen peroxide generated in close proximity to the red cell membrane in conjunction with the autoxidation of membrane-bound hemoglobin.

  12. Benzene-Induced Uncoupling of Naphthalene Dioxygenase Activity and Enzyme Inactivation by Production of Hydrogen Peroxide

    PubMed Central

    Lee, Kyoung

    1999-01-01

    Naphthalene dioxygenase (NDO) is a multicomponent enzyme system that oxidizes naphthalene to (+)-cis-(1R,2S)-1,2-dihydroxy-1,2-dihydronaphthalene with consumption of O2 and two electrons from NAD(P)H. In the presence of benzene, NADH oxidation and O2 utilization were partially uncoupled from substrate oxidation. Approximately 40 to 50% of the consumed O2 was detected as hydrogen peroxide. The rate of benzene-dependent O2 consumption decreased with time, but it was partially increased by the addition of catalase in the course of the O2 consumption by NDO. Detailed experiments showed that the total amount of O2 consumed and the rate of benzene-induced O2 consumption increased in the presence of hydrogen peroxide-scavenging agents, and further addition of the terminal oxygenase component (ISPNAP) of NDO. Kinetic studies showed that ISPNAP was irreversibly inactivated in the reaction that contained benzene, but the inactivation was relieved to a high degree in the presence of catalase and partially relieved in the presence of 0.1 mM ferrous ion. Benzene- and naphthalene-reacted ISPNAP gave almost identical visible absorption spectra. In addition, hydrogen peroxide added at a range of 0.1 to 0.6 mM to the reaction mixtures inactivated the reduced ISPNAP containing mononuclear iron. These results show that hydrogen peroxide released during the uncoupling reaction acts both as an inhibitor of benzene-dependent O2 consumption and as an inactivator of ISPNAP. It is proposed that the irreversible inactivation of ISPNAP occurs by a Fenton-type reaction which forms a strong oxidizing agent, hydroxyl radicals (·OH), from the reaction of hydrogen peroxide with ferrous mononuclear iron at the active site. Furthermore, when [14C]benzene was used as the substrate, cis-benzene 1,2-dihydrodiol formed by NDO was detected. This result shows that NDO also couples a trace amount of benzene to both O2 consumption and NADH oxidation. PMID:10217759

  13. Hydrogen sulfide decreases the plasma lipid peroxidation induced by homocysteine and its thiolactone.

    PubMed

    Olas, Beata; Kontek, Bogdan

    2015-06-01

    Hydrogen sulfide (H2S) has been investigated widely in recent years. H2S plays a variety of roles in different biological systems, including cardiovascular system. It is the final product of amino acids metabolism, which contains sulfur-cysteine and homocysteine (Hcy). In human plasma, there are several various forms of homocysteine: free Hcy, protein-bound Hcy (S-linked, and N-linked), and homocysteine thiolactone (HTL). Our previous works have shown that both Hcy in the reduced form and its thiolactone may modify fibrinolysis, coagulation process, and biological activity of blood platelets. Moreover, we have observed that HTL, like its precursor-Hcy stimulated the generation of superoxide anion radicals (O 2 (-•) ) in blood platelets. The aim of our study in vitro was to establish the influence of sodium hydrosulfide (NaHS, as a fast-releasing H2S donor; at tested concentrations: 10-1000 µM) on the plasma lipid peroxidation induced by the reduced Hcy (at final concentrations of 0.01-1 mM) and HTL (at final concentrations of 0.1-1 µM). Our results indicate that 10 and 100 µM NaHS decreased the lipid peroxidation in plasma treated with 1 mM Hcy or 1 µM HTL (when NaHS and Hcy/HTL were added to plasma together). The protective effect of 10 and 100 µM NaHS against the lipid peroxidation in plasma preincubated with 1 mM Hcy or 1 µM HTL was also observed. Considering the data presented in this study, we suggest that the lipid peroxidation (induced by different forms of homocysteine) may be reduced by hydrogen sulfide.

  14. Ferricytochrome c protects mitochondrial cytochrome c oxidase against hydrogen peroxide-induced oxidative damage.

    PubMed

    Sedlák, Erik; Fabian, Marian; Robinson, Neal C; Musatov, Andrej

    2010-11-30

    An excess of ferricytochrome c protects purified mitochondrial cytochrome c oxidase and bound cardiolipin from hydrogen peroxide-induced oxidative modification. All of the peroxide-induced changes within cytochrome c oxidase, such as oxidation of Trp(19,IV) and Trp(48,VIIc), partial dissociation of subunits VIa and VIIa, and generation of cardiolipin hydroperoxide, no longer take place in the presence of ferricytochrome c. Furthermore, ferricytochrome c suppresses the yield of H(2)O(2)-induced free radical detectable by electron paramagnetic resonance spectroscopy within cytochrome c oxidase. These protective effects are based on two mechanisms. The first involves the peroxidase/catalase-like activity of ferricytochrome c, which results in the decomposition of H(2)O(2), with the apparent bimolecular rate constant of 5.1±1.0M(-1)s(-1). Although this value is lower than the rate constant of a specialized peroxidase, the activity is sufficient to eliminate H(2)O(2)-induced damage to cytochrome c oxidase in the presence of an excess of ferricytochrome c. The second mechanism involves ferricytochrome c-induced quenching of free radicals generated within cytochrome c oxidase. These results suggest that ferricytochrome c may have an important role in protection of cytochrome c oxidase and consequently the mitochondrion against oxidative damage.

  15. Protective effects of benidipine on hydrogen peroxide-induced injury in rat isolated hearts.

    PubMed

    Yao, Kozo; Ina, Yasuhiro; Sonoda, Rie; Nagashima, Ken; Ohmori, Kenji; Ohno, Tetsuji

    2003-01-01

    We investigated the effects of benidipine (hydrochloride), a calcium antagonist, on hydrogen peroxide (H(2)O(2))-induced injury in Langendorff-perfused rat hearts. The hearts were aerobically perfused at a constant flow and exposed to H(2)O(2) (600 micromol L(-1)) for 4 min, resulting in the oxidative stress-induced myocardial dysfunction (e.g., decrease in the left ventricular developed pressure) and myocardial cell injury (e.g., increase in the release of lactate dehydrogenase). Pretreatment of the hearts with benidipine or nifedipine was performed for 20 min until the start of H(2)O(2) exposure. Benidipine at 1 nmol L(-1) and nifedipine at 10 nmol L(-1) decreased the myocardial contractility and perfusion pressure to a similar degree in the hearts under normal conditions. Benidipine (1 nmol L(-1)) significantly reduced the H(2)O(2)-induced myocardial damage. Nifedipine (10 nmol L(-1)) also tended to exhibit similar effects. Benidipine inhibited the increase in tissue lipid peroxidation induced by H(2)O(2). The results suggest that, in addition to the calcium antagonism, benidipine possesses other actions responsible for the cardioprotective effects, to which the antioxidant activity of benidipine may partly contribute.

  16. Estrogens protect against hydrogen peroxide and arachidonic acid induced DNA damage.

    PubMed

    Tang, M; Subbiah, M T

    1996-01-19

    The ability of estrogens to protect against DNA damage induced by either hydrogen peroxide or arachidonic acid alone or in combination with Cu2+ was investigated. DNA strand breaks were determined by conversion of double stranded supercoiled OX-174 RFI DNA to double stranded open circular DNA and linear single stranded DNA. Estradiol-17 beta significantly decreased the formation of single and double strand breaks in DNA induced by H2O2 alone or with Cu2+. Equilin (an equine estrogen) was more effective than estradiol-17 beta at the doses tested. Arachidonic acid in the presence of Cu2+ caused the formation of high levels of linear DNA which was protected by estrogen with equilen being more effective. These studies suggest that estrogens through this protective effect on DNA damage might contribute to cardioprotection.

  17. [RAD18 gene product of yeast Saccharomyces cerevisiae controls mutagenesis induced by hydrogen peroxide].

    PubMed

    Kozhina, T N; Korolev, V G

    2012-04-01

    Within eukaryotes, tolerance to DNA damage is determined primarily by the repair pathway controlled by the members of the RAD6 epistasis group. Genetic studies on a yeast Saccharomyces cerevisiae model showed that the initial stage of postreplication repair (PRR), i.e., initiation of replication through DNA damage, is controlled by Rad6-Rad18 ubiquitin-conjugating enzyme complex. Mutants of these genes are highly sensitive to various genotoxic agents and reduce the level of induced mutagenesis. In this case, the efficiency of mutagenesis suppression depends on the type of damage. In this study we showed that DNA damage induced by hydrogen peroxide at the same mutagen doses causes significantly more mutations and lethal events in the rad18 mutant cells compared to control wild-type cells.

  18. 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.

  19. In vivo imaging of hydrogen peroxide with chemiluminescent nanoparticles.

    PubMed

    Lee, Dongwon; Khaja, Sirajud; Velasquez-Castano, Juan C; Dasari, Madhuri; Sun, Carrie; Petros, John; Taylor, W Robert; Murthy, Niren

    2007-10-01

    The overproduction of hydrogen peroxide is implicated in the development of numerous diseases and there is currently great interest in developing contrast agents that can image hydrogen peroxide in vivo. In this report, we demonstrate that nanoparticles formulated from peroxalate esters and fluorescent dyes can image hydrogen peroxide in vivo with high specificity and sensitivity. The peroxalate nanoparticles image hydrogen peroxide by undergoing a three-component chemiluminescent reaction between hydrogen peroxide, peroxalate esters and fluorescent dyes. The peroxalate nanoparticles have several attractive properties for in vivo imaging, such as tunable wavelength emission (460-630 nm), nanomolar sensitivity for hydrogen peroxide and excellent specificity for hydrogen peroxide over other reactive oxygen species. The peroxalate nanoparticles were capable of imaging hydrogen peroxide in the peritoneal cavity of mice during a lipopolysaccharide-induced inflammatory response. We anticipate numerous applications of peroxalate nanoparticles for in vivo imaging of hydrogen peroxide, given their high specificity and sensitivity and deep-tissue-imaging capability.

  20. Shark-cartilage containing preparation protects cells against hydrogen peroxide induced damage and mutagenesis.

    PubMed

    Gomes, E M; Souto, P R; Felzenszwalb, I

    1996-04-06

    Natural products from flora and fauna are frequently used as nutritional supplements and medicaments. Two short-term assays were carried out and negative results were obtained for shark-cartilage containing preparation. The tests employed were the Salmonella/mammalian microsome assay using tester strains TA97, TA98, TA100, TA102 and TA1535 with or without S9 mix and the SOS-Chromotest with Escherichia coli strain PQ37. Evidence for shark-cartilage containing preparation functioning as an antimutagen was detected. Using bacterial survival assays with Escherichia coli fpg (BH20) and xthA (BW9091), we investigated the putative role of shark-cartilage containing preparation in protecting cells against lesions induced by hydrogen peroxide in normal and low iron level conditions. Our data suggest that shark-cartilage containing preparation can play a scavenger role for reactive oxygen species and protect against DNA lesions in both conditions.

  1. 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

    2009-10-02

    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.

  2. 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.

  3. Protective effect of docosahexaenoic acid against hydrogen peroxide-induced oxidative stress in human lymphocytes.

    PubMed

    Bechoua, S; Dubois, M; Dominguez, Z; Goncalves, A; Némoz, G; Lagarde, M; Prigent, A F

    1999-05-01

    Oxidatively stressed lymphocytes exhibit decreased proliferative response to mitogenic stimulation. Although several sensitive targets involved in lymphocyte suppression have already been identified, little is known about the influence of oxidative stress on cyclic nucleotide phosphodiesterases (PDE) (EC 3.1.4.17), thought to play a major role in the control of cyclic AMP (cAMP) level, a well-recognized negative effector of lymphoproliferation. Although the polyunsaturated fatty acid content of membrane phospholipids is thought to be directly related to the extent of oxidant-induced lipid peroxidation, some n-3 fatty acids also seem to have antioxidant effects, depending on the concentration used and the overall redox status of the cells in question. Results of the present study showed that human peripheral blood mononuclear cells (PBMC) as well as rat thymocytes were relatively resistant to a short-term exposure (10 min) to hydrogen peroxide (H2O2). Indeed, H2O2-induced lipid peroxidation, estimated by malondialdehyde (MDA) production, was only 2-fold increased by H2O2 concentrations lower than 2 mM, whereas a larger increase (10-fold) could be observed in PBMC at the highest dose (5 mM). Previous enrichment of PBMC with 5 microM docosahexaenoic acid (22:6n-3), brought to the cells as a fatty acid-albumin complex (ratio 1), significantly reduced MDA production induced by low doses of H2O2, the protective effect no longer being observed at the highest doses. In contrast, eicosapentaenoic acid (20:5n-3) did not have any protective effect. Cytosolic PDE activities of both human PBMC and rat thymocytes were significantly inhibited (40-50%) after H2O2 treatment of the cells, whereas particulate PDE activities were not modified. Different responses of PDE activities to H2O2 treatment were observed when PBMC were first enriched with 22:6n-3 prior to H2O2 addition. In 22:6n-3-treated cells, the H2O2-induced inhibition of both cAMP- and cGMP-PDE cytosolic activities was

  4. Role of mitochondrial hydrogen peroxide induced by intermittent hypoxia in airway epithelial wound repair in vitro.

    PubMed

    Hamada, Satoshi; Sato, Atsuyasu; Hara-Chikuma, Mariko; Satooka, Hiroki; Hasegawa, Koichi; Tanimura, Kazuya; Tanizawa, Kiminobu; Inouchi, Morito; Handa, Tomohiro; Oga, Toru; Muro, Shigeo; Mishima, Michiaki; Chin, Kazuo

    2016-05-15

    The airway epithelium acts as a frontline barrier against various environmental insults and its repair process after airway injury is critical for the lung homeostasis restoration. Recently, the role of intracellular reactive oxygen species (ROS) as transcription-independent damage signaling has been highlighted in the wound repair process. Both conditions of continuous hypoxia and intermittent hypoxia (IH) induce ROS. Although IH is important in clinical settings, the roles of IH-induced ROS in the airway repair process have not been investigated. In this study, we firstly showed that IH induced mitochondrial hydrogen peroxide (H2O2) production and significantly decreased bronchial epithelial cell migration, prevented by catalase treatment in a wound scratch assay. RhoA activity was higher during repair process in the IH condition compared to in the normoxic condition, resulting in the cellular morphological changes shown by immunofluorescence staining: round cells, reduced central stress fiber numbers, pronounced cortical actin filament distributions, and punctate focal adhesions. These phenotypes were replicated by exogenous H2O2 treatment under the normoxic condition. Our findings confirmed the transcription-independent role of IH-induced intracellular ROS in the bronchial epithelial cell repair process and might have significant implications for impaired bronchial epithelial cell regeneration.

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

    PubMed

    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.

  6. 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

  7. Differential roles of hydrogen peroxide and hydroxyl radical in cisplatin-induced cell death in renal proximal tubular epithelial cells.

    PubMed

    Baek, Su Mi; Kwon, Chae Hwa; Kim, Jae Ho; Woo, Jae Suk; Jung, Jin Sup; Kim, Yong Keun

    2003-09-01

    Reactive oxygen species (ROS) have been suggested as important mediators of cisplatin-induced acute renal failure in vivo. However, our previous studies have shown that cisplatin-induced cell death in vitro could not be prevented by scavengers of hydrogen peroxide and hydroxyl radical in rabbit renal cortical slices. This discrepancy may be attributed to differential roles of ROS in necrotic and apoptotic cell death. We therefore examined, in this study, the roles of ROS in necrosis and apoptosis induced by cisplatin in primary cultured rabbit proximal tubule. Cisplatin induced necrosis at high concentrations over a few hours and apoptosis at much lower concentrations over longer periods. Necrosis induced by high concentration of cisplatin was prevented by a cell-permeable superoxide scavenger (tiron), hydrogen peroxide scavengers (catalase and pyruvate), and antioxidants (Trolox and deferoxamine), whereas hydroxyl radical scavengers (dimethythiourea and thiourea) did not affect the cisplatin-induced necrosis. However, apoptosis induced by lower concentration of cisplatin was partially prevented by tiron and hydroxyl radical scavengers but not by hydrogen peroxide scavengers and antioxidants. Cisplatin-induced apoptosis was mediated by the signaling pathway that is associated with cytochrome c release from mitochondria and caspase-3 activation. These effects were prevented by tiron and dimethylthiourea but not by catalase. Dimethylthiourea produced a significant protection against cisplatin-induced acute renal failure, and the effect was associated with an inhibition of apoptosis. These results suggest that hydrogen peroxide is involved in the cisplatin-induced necrosis, whereas hydroxyl radical is responsible for the cisplatin-induced apoptosis. The protective effects of hydroxyl radical scavengers are associated with an inhibition of cytochrome c release and caspase activation.

  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. The Beneficial Effect of Ginsenoside Rg1 on Schwann Cells Subjected to Hydrogen Peroxide Induced Oxidative Injury

    PubMed Central

    Ma, Junxiong; Liu, Jun; Wang, Qi; Yu, Hailong; Chen, Yu; Xiang, Liangbi

    2013-01-01

    Ginsenoside Rg1 (GRg1) has been considered to have therapeutic potential in promoting peripheral nerve regeneration and functional recovery after sciatic nerve injuries. However, the mechanism underlying the beneficial effect of GRg1 on peripheral nerve regeneration is currently unclear. The possible effect of GRg1 on Schwann cells (SCs), which were subjected to oxidative injury after nerve injury, might contribute to the beneficial effect of GRg1 on nerve regeneration. The present study was designed to investigate the potential beneficial effect of GRg1 on SCs exposed to oxidative injury. The oxidative injury to SCs was induced by hydrogen peroxide. The effect of GRg1 (50 μM) on SCs exposed to oxidative injury was measured by the levels of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH) and catalase (CAT) in SCs. The cell number and cell viability of SCs were evaluated through fluorescence observation and MTT assay. The apoptosis of SCs induced by oxidative injury was evaluated by an apoptosis assay. The expression and secretion of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) were evaluated using RT-PCR, Western blotting, and an ELISA method. We found that GRg1 significantly up-regulated the level of SOD, GSH and CAT, and decreased the level of MDA in SCs treated with hydrogen peroxide. In addition, GRg1 has been shown to be able to inhibit the proapoptotic effect of hydrogen peroxide, as well as inhibit the detrimental effect of hydrogen peroxide on cell number and cell viability. Furthermore, GRg1 also increased the mRNA levels, protein levels and secretion of NGF and BDNF in SCs after incubation of hydrogen peroxide. Further study showed that preincubation with H89 (a PKA inhibitor) significantly inhibited the effects induced by hydrogen peroxide, indicating that the PKA pathway might be involved in the antioxidant effect and neurotrophic factors (NTFs) promoting effect of GRg1. In addition, a short-term in vivo

  10. Hypoxia induces Wee1 expression and attenuates hydrogen peroxide-induced endothelial damage in MS1 cells

    PubMed Central

    Hong, Ki-Sun; Kim, Hyeon-Soo; Kim, Se-Hoon; Lim, Dong-Jun; Park, Jung-Yul

    2011-01-01

    In an oxygen-depleted environment, endothelial cells initiate an adaptive pattern of synthesis, which may enable them to survive hypoxic crises. Using high-resolution two-dimensional gel electrophoresis in conjunction with mass spectroscopy, we obtained a 24 differential display of proteins in the pancreatic endothelial cell line, MS-1, at four time points following induction of hypoxia. The induction of Wee1 under hypoxia was confirmed both at the mRNA and protein levels. The phosphorylation of cell division cycle 2, which is downstream of Wee1, was also increased after hypoxic exposure. In addition, pre-exposure to hypoxia attenuated a decrease in hydrogen peroxide-induced cell number. The induction of bax (a pro-apoptotic protein) and reduction of bcl (an anti-apoptotic protein) after hypoxia stimulus were also attenuated by hypoxic pre-exposure. Moreover, hydrogen peroxide-induced morphologic damage did not appear in the wild-type Wee1-expressing cells. Taken together, our results suggest that Wee1 may have important role in hypoxia-induced pathophysiological situations in endothelial cells. PMID:21918363

  11. Effect of vitamin C administration on hydrogen peroxide-induced cytotoxicity in periodontal ligament cells.

    PubMed

    Wu, Wenlei; Yang, Nanfei; Feng, Xiujing; Sun, Tingzhe; Shen, Pingping; Sun, Weibin

    2015-01-01

    Periodontitis is a disease, which is associated with chronic inflammation and leads to significant destruction of periodontal tissues. Periodontal ligament cells (PDLCs) constitute the largest cell population in PDL tissues and a considerable body of evidence has demonstrated an association between oxidative stress and the progression of periodontitis. However, the effects on PDLCs exposed to hydrogen peroxide (H2O2) and the molecular mechanisms by which H2O2 affects periodontitis remain to be elucidated. In the present study, the potential cytotoxic effect of H2O2 and the antioxidative function of vitamin C (Vc) in PDLCs were investigated. The results demonstrated that H2O2 treatment decreased the viability of PDLCs. The decreased PDLC viability was primarily induced by apoptosis, which was evidenced by cleaved caspases-3, caspases-9 and poly (ADP-ribose) polymerase. Following optimal Vc addition, the proapoptotic effects of H2O2 were partially antagonized. Taken together, the present study demonstrated that H2O2 primarily induced the apoptosis of PDLCs and that these adverse effects were partially rescued following treatment with Vc. These results revealed how H2O2 promotes the progression of periodontitis and provide an improved understanding of the reversal effect of antioxidant treatment. Therefore, optimal Vc administration may provide a potentially effective technique in periodontal therapy.

  12. Neuroprotective effect of didymin on hydrogen peroxide-induced injury in the neuronal membrane system.

    PubMed

    Morelli, Sabrina; Piscioneri, Antonella; Salerno, Simona; Al-Fageeh, Mohamed B; Drioli, Enrico; De Bartolo, Loredana

    2014-01-01

    In this study, the flavonoid didymin was administered in vitro in neuronal cells after hydrogen peroxide (H2O2)-induced injury (neurorescue) in order to investigate the effects of this natural molecule on cell damage in a neuronal membrane system. The results showed the effects of didymin in neuronal cells by using a polycaprolactone biodegradable membrane system as an in vitro model. Two major findings are presented in this study: first is the antioxidant property of didymin and, second, for the first time we provide evidence concerning its ability to rescue neuronal cells from oxidative damage. Didymin showed radical scavenging activities and it protected the neuronal cells against H2O2-induced neurotoxicity. Didymin increased cell viability, decreased intracellular reactive oxygen species generation, stimulated superoxide dismutase, catalase and glutathione peroxidase activity in neuronal cells which were previously insulted with H2O2. In addition, didymin strikingly inhibited H2O2-induced mitochondrial dysfunctions in terms of reduction of mitochondria membrane potential and the activation of cleaved caspase-3, and also decreased dramatically the H2O2-induced phosphorylation of c-Jun N-terminal kinase. Therefore, this molecule is capable of inducing recovery from oxidative damage, and promoting and/or restoring normal cellular conditions. Moreover, the mechanism underlying the protective effects of didymin in H2O2-injured neuronal cells might be related to the activation of antioxidant defense enzymes as well as to the inhibition of apoptotic features, such as p-JNK and caspase-3 activation. These data suggest that didymin may be a potential therapeutic molecule for the treatment of neurodegenerative disorders associated with oxidative stress.

  13. 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.

  14. 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.

  15. 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

  16. MicroRNA-135a Regulates Apoptosis Induced by Hydrogen Peroxide in Rat Cardiomyoblast Cells

    PubMed Central

    Liu, Ning; Shi, Yong-Feng; Diao, Hong-Ying; Li, Yang-Xue; Cui, Yan; Song, Xian-Jing; Tian, Xin; Li, Tian-Yi; Liu, Bin

    2017-01-01

    Oxidative stress and apoptosis are the most important pathologic features of ischemic heart disease. Recent research has indicated that microRNAs (miRs) play an essential role in apoptosis. However, whether miRs might regulate B cell lymphoma-2 (Bcl-2) protein in apoptosis during ischemic heart disease is still unclear. The aim of this study, therefore, was to confirm the regulation of microRNA-135a (miR-135a) in oxidative stress injuries induced by hydrogen peroxide (H2O2) in rat cardiomyoblast cells H9c2. To this end, we analyzed the effects of H2O2 treatment on miR-135a expression in rat cardiomyocytes. Furthermore, we upregulated and inhibited miR-135a using mimics and inhibitors, respectively, and examined the effects on cell viability and apoptosis-related proteins. We observed that miR-135a was markedly up-regulated under H2O2 treatment in rat cardiomyoblast cells. Overexpression of miR-135a blocked the Bcl-2 protein and enhanced the apoptosis induced by H2O2, and miR-135a inhibition restored Bcl-2 protein expression. Interestingly, miR-135a inhibition did not attenuate H2O2-induced apoptosis with Bcl-2 knockdown. The results of the present study indicate that miR-135a regulates H2O2-induced apoptosis in H9c2 cells via targeting Bcl-2, and that miR-135a may be a novel therapeutic target for ischemic heart disease. PMID:28123342

  17. A hydrogen peroxide-generating agent, 6-formylpterin, enhances heat-induced apoptosis.

    PubMed

    Wada, S; Cui, Z-G; Kondo, T; Zhao, Q-L; Ogawa, R; Shoji, M; Arai, T; Makino, K; Furuta, I

    2005-05-01

    The enhancement of heat-induced apoptosis by 6-formylpterin, an intra-cellular generator of hydrogen peroxide (H2O2), was examined in human myelomonocytic lymphoma U937 cells. The cells were treated with either 6-formylpterin alone at a nontoxic concentration of 300 microM (37 degrees C), heat shock (44 degrees C per 20 min) alone or a combination of the two, then incubated at 37 degrees C for 6 h. Assessments of apoptosis, mitochondrial membrane potential and caspase-3 activation were performed by flow cytometry. Moreover, caspase-8 activation and changes in the intra-cellular Ca2+ concentration ([Ca2+]i) were examined. Bax, Bcl-2, Bcl-XL, Bid, cytochrome c and PKCd were detected by Western blotting. The induction of heat-induced apoptosis evaluated by morphological observation and DNA fragmentation were promoted by the addition of 6-formylpterin. Mitochondrial membrane potential was decreased and the activation of caspase-3 and -8 was enhanced in the cells treated with the combination. A decreased-expression of Bid was noted, although no significant changes in Bax, Bcl-2 and Bcl-XL expression were observed after the combined treatment. Furthermore, both the release of cytochrome c from mitochondria to cytosol and the translocation of PKCd from cytosol to mitochondria, which were induced by heat shock, were enhanced by the addition of 6-formylpterin. The number of cells with a higher [Ca2+]i was also increased by the addition of 6-formylpterin. These findings suggest that the increase in [Ca2+]i, the activation of the mitochondria-caspase dependent pathway and the translocation of PKCd to mitochondria play principal roles in the enhancement of heat-induced apoptosis by 6-FP.

  18. Geraniol attenuates hydrogen peroxide-induced liver fatty acid alterations in male rats

    PubMed Central

    Ozkaya, Ahmet; Sahin, Zafer; Gorgulu, Ahmet Orhan; Yuce, Abdurrauf; Celik, Sait

    2017-01-01

    Background: Hydrogen peroxide (H2O2) is an oxidant agent and this molecule naturally occurs in the body as a product of aerobic metabolism. Geraniol is a plant-derived natural antioxidant. The aim of this study was to determine the role of geraniol on hepatic fatty acids alterations following H2O2-induced oxidative stress in male rats. Methods: After randomization, male Wistar rats were divided into four groups (n = 7 each group). Geraniol (50 mg/kg, dissolved in corn oil) and H2O2 (16 mg/kg, dissolved in distilled water) were administered by an intraperitoneal injection. Administrations were performed during 30 days with 1-day interval. Results: Administration of H2O2 resulted with a significant increase in malondialdehyde (MDA) and a significant decrease in glutathione (GSH) peroxidase glutathione level; geraniol restored its effects on liver. However, hepatic catalase (CAT) activities were significantly higher in H2O2, geraniol, and geraniol+H2O2 groups than control group. The ratio of hepatic total saturated fatty acids increased in H2O2-treated animals compared with control. In addition, hepatic total unsaturated fatty acids reduced in H2O2 group compared with control. The percentages of both hepatic total saturated and unsaturated fatty acids were not different between geraniol+H2O2 and control groups. Conclusions: H2O2-induced oxidative stress may affect fatty acid composition in liver and body. Geraniol can partly restore oxidative hepatic damage because it cannot completely reverse the H2O2-induced increase in hepatic CAT activities. Moreover, this natural compound can regulate hepatic total saturated and unsaturated fatty acids percentages against H2O2-induced alterations. PMID:28163957

  19. Protective effect of oat bran extracts on human dermal fibroblast injury induced by hydrogen peroxide.

    PubMed

    Feng, Bing; Ma, Lai-ji; Yao, Jin-jing; Fang, Yun; Mei, Yan-ai; Wei, Shao-min

    2013-02-01

    Oat contains different components that possess antioxidant properties; no study to date has addressed the antioxidant effect of the extract of oat bran on the cellular level. Therefore, the present study focuses on the investigation of the protective effect of oat bran extract by enzymatic hydrolysates on human dermal fibroblast injury induced by hydrogen peroxide (H(2)O(2)). Kjeldahl determination, phenol-sulfuric acid method, and high-performance liquid chromatography (HPLC) analysis indicated that the enzymatic products of oat bran contain a protein amount of 71.93%, of which 97.43% are peptides with a molecular range from 438.56 to 1301.01 Da. Assays for 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity indicate that oat peptide-rich extract has a direct and concentration-dependent antioxidant activity. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay and the TdT-mediated digoxigenin-dUTP nick-end labeling (TUNEL) assay for apoptosis showed that administration of H(2)O(2) in human dermal fibroblasts caused cell damage and apoptosis. Pre-incubation of human dermal fibroblasts with the Oatp for 24 h markedly inhibited human dermal fibroblast injury induced by H(2)O(2), but application oat peptides with H(2)O(2) at same time did not. Pre-treatment of human dermal fibroblasts with Oatp significantly reversed the H(2)O(2)-induced decrease of superoxide dismutase (SOD) and the inhibition of malondialdehyde (MDA). The results demonstrate that oat peptides possess antioxidant activity and are effective against H(2)O(2)-induced human dermal fibroblast injury by the enhanced activity of SOD and decrease in MDA level. Our results suggest that oat bran will have the potential to be further explored as an antioxidant functional food in the prevention of aging-related skin injury.

  20. 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...

  1. 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...

  2. 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...

  3. Microbial resistance in relation to catalase activity to oxidative stress induced by photolysis of hydrogen peroxide.

    PubMed

    Nakamura, Keisuke; Kanno, Taro; Mokudai, Takayuki; Iwasawa, Atsuo; Niwano, Yoshimi; Kohno, Masahiro

    2012-01-01

    The purpose of the present study was to evaluate the mechanism of microbial resistance to oxidative stress induced by photolysis of hydrogen peroxide (H(2)O(2)) in relation to microbial catalase activity. In microbicidal tests, Staphylococcus aureus and Candida albicans were killed and this was accompanied by production of hydroxyl radicals. C. albicans was more resistant to hydroxyl radicals generated by photolysis of H(2)O(2) than was S. aureus. A catalase activity assay demonstrated that C. albicans had stronger catalase activity; accordingly, catalase activity could be one of the reasons for the resistance of the fungus to photolysis of H(2)O(2). Indeed, it was demonstrated that C. albicans with strong catalase activity was more resistant to photolysis of H(2)O(2) than that with weak catalase activity. Kinetic analysis using a modified Lineweaver-Burk plot also demonstrated that the microorganisms reacted directly with hydroxyl radicals and that this was accompanied by decomposition of H(2)O(2). The results of the present study suggest that the microbicidal effects of hydroxyl radicals generated by photolysis of H(2)O(2) can be alleviated by decomposition of H(2)O(2) by catalase in microorganisms.

  4. Resveratrol attenuates L-DOPA-induced hydrogen peroxide toxicity in neuronal cells.

    PubMed

    Peritore, Carina S; Ho, Angela; Yamamoto, Bryan K; Schaus, Scott E

    2012-12-05

    A variety of polyphenol antioxidant compounds derived from natural products have demonstrated neuroprotective activity against neuronal cell death. The objective of this study was to investigate the effect of resveratrol (RESV) and bioflavonoids in attenuating hydrogen peroxide (H(2)O(2))-induced oxidative stress in neuronal cells. H2O2 levels were increased by the addition of L-3,4-dihydroxyphenylalanine (L-DOPA) to cultured dopaminergic SKNSH cells. H(2)O(2) was monitored by peroxyfluor-1, a selective H(2)O(2) optical probe. To examine the neuroprotective effects of RESV and bioflavonoids against L-DOPA, we cotreated RESV, quercetin, or (-) epigallocatechin gallate with L-DOPA and monitored for H(2)O(2) levels. The combination of RESV and L-DOPA was 50% more effective at reducing H(2)O(2) levels than the combination of quercetin or epigallocatechin gallate with L-DOPA. However, the combination of each antioxidant with L-DOPA was effective at preserving cell viability.

  5. Hydrogen peroxide induces a rapid production of nitric oxide in mung bean (Phaseolus aureus).

    PubMed

    Lum, H K; Butt, Y K C; Lo, S C L

    2002-03-01

    Nitric oxide (NO) has recently been identified as an important signaling molecule in plant immune response. The present study aims to investigate the signaling pathway that leads to NO production. Using the NO specific fluorescent dye DAF-2DA, we observed rapid production of NO in mung bean leaves after the addition of 10 mM hydrogen peroxide (H(2)O(2)). NO was probably produced by a NOS-like enzyme in plants, as the NO production was inhibited by l-NAME, a NOS inhibitor. The NOS-like activity in the total leaf protein preparation of mung bean (Phaseolus aureus) was elevated 8.3-fold after 10 mM H(2)O(2) treatment, as demonstrated using the chemiluminescence NOS assay. The NOS-like activity was BH(4) dependent: omitting BH(4) in the reaction mixture of NOS assay reduced the NOS activity by 76%. We also found that the H(2)O(2) induced NO production was mediated via calcium ion flux, as it was blocked in the presence of a calcium ion channel blocker, verapamil. Results from the present study identified H(2)O(2) as an upstream signal that leads to NO production in plants. H(2)O(2) and NO, besides acting as two independent signaling molecules in plant immune response, may interrelate to form an oxidative cell death (OCD) cycle.

  6. 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

    2016-07-09

    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.

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

    PubMed Central

    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. PMID:26633563

  8. Sailuotong Prevents Hydrogen Peroxide (H2O2)-Induced Injury in EA.hy926 Cells

    PubMed Central

    Seto, Sai Wang; Chang, Dennis; Ko, Wai Man; Zhou, Xian; Kiat, Hosen; Bensoussan, Alan; Lee, Simon M. Y.; Hoi, Maggie P. M.; Steiner, Genevieve Z.; Liu, Jianxun

    2017-01-01

    Sailuotong (SLT) is a standardised three-herb formulation consisting of Panax ginseng, Ginkgo biloba, and Crocus sativus designed for the management of vascular dementia. While the latest clinical trials have demonstrated beneficial effects of SLT in vascular dementia, the underlying cellular mechanisms have not been fully explored. The aim of this study was to assess the ability and mechanisms of SLT to act against hydrogen peroxide (H2O2)-induced oxidative damage in cultured human vascular endothelial cells (EAhy926). SLT (1–50 µg/mL) significantly suppressed the H2O2-induced cell death and abolished the H2O2-induced reactive oxygen species (ROS) generation in a concentration-dependent manner. Similarly, H2O2 (0.5 mM; 24 h) caused a ~2-fold increase in lactate dehydrogenase (LDH) release from the EA.hy926 cells which were significantly suppressed by SLT (1–50 µg/mL) in a concentration-dependent manner. Incubation of SLT (50 µg/mL) increased superoxide dismutase (SOD) activity and suppressed the H2O2-enhanced Bax/Bcl-2 ratio and cleaved caspase-3 expression. In conclusion, our results suggest that SLT protects EA.hy916 cells against H2O2-mediated injury via direct reduction of intracellular ROS generation and an increase in SOD activity. These protective effects are closely associated with the inhibition of the apoptotic death cascade via the suppression of caspase-3 activation and reduction of Bax/Bcl-2 ratio, thereby indicating a potential mechanism of action for the clinical effects observed. PMID:28067784

  9. Sailuotong Prevents Hydrogen Peroxide (H₂O₂)-Induced Injury in EA.hy926 Cells.

    PubMed

    Seto, Sai Wang; Chang, Dennis; Ko, Wai Man; Zhou, Xian; Kiat, Hosen; Bensoussan, Alan; Lee, Simon M Y; Hoi, Maggie P M; Steiner, Genevieve Z; Liu, Jianxun

    2017-01-05

    Sailuotong (SLT) is a standardised three-herb formulation consisting of Panax ginseng, Ginkgo biloba, and Crocus sativus designed for the management of vascular dementia. While the latest clinical trials have demonstrated beneficial effects of SLT in vascular dementia, the underlying cellular mechanisms have not been fully explored. The aim of this study was to assess the ability and mechanisms of SLT to act against hydrogen peroxide (H₂O₂)-induced oxidative damage in cultured human vascular endothelial cells (EAhy926). SLT (1-50 µg/mL) significantly suppressed the H₂O₂-induced cell death and abolished the H₂O₂-induced reactive oxygen species (ROS) generation in a concentration-dependent manner. Similarly, H₂O₂ (0.5 mM; 24 h) caused a ~2-fold increase in lactate dehydrogenase (LDH) release from the EA.hy926 cells which were significantly suppressed by SLT (1-50 µg/mL) in a concentration-dependent manner. Incubation of SLT (50 µg/mL) increased superoxide dismutase (SOD) activity and suppressed the H₂O₂-enhanced Bax/Bcl-2 ratio and cleaved caspase-3 expression. In conclusion, our results suggest that SLT protects EA.hy916 cells against H₂O₂-mediated injury via direct reduction of intracellular ROS generation and an increase in SOD activity. These protective effects are closely associated with the inhibition of the apoptotic death cascade via the suppression of caspase-3 activation and reduction of Bax/Bcl-2 ratio, thereby indicating a potential mechanism of action for the clinical effects observed.

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

    PubMed Central

    Okahashi, Nobuo; Kuwata, Hirotaka; Kawabata, Shigetada

    2016-01-01

    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

  11. Hydrogen peroxide-induced calcium influx in lung microvascular endothelial cells involves TRPV4

    PubMed Central

    Suresh, Karthik; Servinsky, Laura; Reyes, Jose; Baksh, Syeda; Undem, Clark; Caterina, Michael; Pearse, David B.

    2015-01-01

    In acute respiratory distress syndrome, both reactive oxygen species (ROS) and increased intracellular calcium ([Ca2+]i) are thought to play important roles in promoting endothelial paracellular permeability, but the mechanisms linking ROS and [Ca2+]i in microvascular endothelial cells are not known. In this study, we assessed the effect of hydrogen peroxide (H2O2) on [Ca2+]i in mouse and human lung microvascular endothelial cells (MLMVEC and HLMVEC, respectively). We found that in both MLMVECs and HLMVECs, exogenously applied H2O2 increased [Ca2+]i through Ca2+ influx and that pharmacologic inhibition of the calcium channel transient receptor potential vanilloid 4 (TRPV4) attenuated the H2O2-induced Ca2+ influx. Additionally, knockdown of TRPV4 in HLMVEC also attenuated calcium influx following H2O2 challenge. Administration of H2O2 or TRPV4 agonists decreased transmembrane electrical resistance (TER), suggesting increased barrier permeability. To explore the regulatory mechanisms underlying TRPV4 activation by ROS, we examined H2O2-induced Ca2+ influx in MLMVECs and HLMVECs with either genetic deletion, silencing, or pharmacologic inhibition of Fyn, a Src family kinase. In both MLMVECs derived from mice deficient for Fyn and HLMVECs treated with either siRNA targeted to Fyn or the Src family kinase inhibitor SU-6656 for 24 or 48 h, the H2O2-induced Ca2+ influx was attenuated. Treatment with SU-6656 decreased the levels of phosphorylated, but not total, TRPV4 protein and had no effect on TRPV4 response to the external agonist, GSK1016790A. In conclusion, our data suggest that application of exogenous H2O2 increases [Ca2+]i and decreases TER in microvascular endothelial cells via activation of TRPV4 through a mechanism that requires the Src kinase Fyn. PMID:26453519

  12. Protective effect of Phyllanthus emblica fruit extract against hydrogen peroxide-induced endothelial cell death.

    PubMed

    Wongpradabchai, Sudjai; Chularojmontri, Linda; Phornchirasilp, Srichan; Wattanapitayakul, Suvara K

    2013-01-01

    Numerous antioxidants from natural products have been shown to lower ROS levels and enhance vascular endothelial function. The fruits of Phyllanthus emblica are well-known in possessing antioxidative properties but its role and mechanisms in the protection of vascular endothelial cells from ROS damage have not yet been established. The present study was aimed to determine the possible protective effect of P. emblica fruit extract (PE) on human EA.hy926 endothelial cell death induced by hydrogen peroxide (H2O2) and PE protective mechanisms. Following incubation of endothelial cells with 300 microM H2O2 for 2 h, cell viability was decreased to 50.65 +/- 0.94% and intracellular ROS levels was increased to 159.01% +/- 6.27% as measured by MTT assay and DCF fluorescent intensity, respectively. Cytotoxic effect of PE was not observed in the range of 0.1 to 100 microM Pretreatment with PE (20 to 100 microg/mL) for 48 h significantly ameliorated the cytotoxic effect of H2O2 and attenuated the excessive intracellular ROS formation in endothelial cells. In addition, western blot analysis revealed that PE pretreatment (40 microg/L) induced Akt phosphorylation but did not activate NF-kappaB pathway. These findings suggest that PE could effectively protect human endothelial cell death induced by H2O2 via modification of ROS-related mechanism along with activation of PI3K/Akt pathway. However the value of this plant in vivo needs further investigations in supporting them to be developed as nutraceuticals for cardiovascular disease prevention.

  13. 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.

  14. The Hog1 MAP Kinase Promotes the Recovery from Cell Cycle Arrest Induced by Hydrogen Peroxide in Candida albicans

    PubMed Central

    Correia, Inês; Alonso-Monge, Rebeca; Pla, Jesús

    2017-01-01

    Eukaryotic cell cycle progression in response to environmental conditions is controlled via specific checkpoints. Signal transduction pathways mediated by MAPKs play a crucial role in sensing stress. For example, the canonical MAPKs Mkc1 (of the cell wall integrity pathway), and Hog1 (of the HOG pathway), are activated upon oxidative stress. In this work, we have analyzed the effect of oxidative stress induced by hydrogen peroxide on cell cycle progression in Candida albicans. Hydrogen peroxide was shown to induce a transient arrest at the G1 phase of the cell cycle. Specifically, a G1 arrest was observed, although phosphorylation of Mkc1 and Hog1 MAPKs can take place at all stages of the cell cycle. Interestingly, hog1 (but not mkc1) mutants required a longer time compared to wild type cells to resume growth after hydrogen peroxide challenge. Using GFP-labeled cells and mixed cultures of wild type and hog1 cells we were able to show that hog1 mutants progress faster through the cell cycle under standard growth conditions in the absence of stress (YPD at 37°C). Consequently, hog1 mutants exhibited a smaller cell size. The altered cell cycle progression correlates with altered expression of the G1 cyclins Cln3 and Pcl2 in hog1 cells compared to the wild type strain. In addition, Hgc1 (a hypha-specific G1 cyclin) as well as Cln3 displayed a different kinetics of expression in the presence of hydrogen peroxide in hog1 mutants. Collectively, these results indicate that Hog1 regulates the expression of G1 cyclins not only in response to oxidative stress, but also under standard growth conditions. Hydrogen peroxide treated cells did not show fluctuations in the mRNA levels for SOL1, which are observed in untreated cells during cell cycle progression. In addition, treatment with hydrogen peroxide prevented degradation of Sol1, an effect which was enhanced in hog1 mutants. Therefore, in C. albicans, the MAPK Hog1 mediates cell cycle progression in response to oxidative

  15. The Hog1 MAP Kinase Promotes the Recovery from Cell Cycle Arrest Induced by Hydrogen Peroxide in Candida albicans.

    PubMed

    Correia, Inês; Alonso-Monge, Rebeca; Pla, Jesús

    2016-01-01

    Eukaryotic cell cycle progression in response to environmental conditions is controlled via specific checkpoints. Signal transduction pathways mediated by MAPKs play a crucial role in sensing stress. For example, the canonical MAPKs Mkc1 (of the cell wall integrity pathway), and Hog1 (of the HOG pathway), are activated upon oxidative stress. In this work, we have analyzed the effect of oxidative stress induced by hydrogen peroxide on cell cycle progression in Candida albicans. Hydrogen peroxide was shown to induce a transient arrest at the G1 phase of the cell cycle. Specifically, a G1 arrest was observed, although phosphorylation of Mkc1 and Hog1 MAPKs can take place at all stages of the cell cycle. Interestingly, hog1 (but not mkc1) mutants required a longer time compared to wild type cells to resume growth after hydrogen peroxide challenge. Using GFP-labeled cells and mixed cultures of wild type and hog1 cells we were able to show that hog1 mutants progress faster through the cell cycle under standard growth conditions in the absence of stress (YPD at 37°C). Consequently, hog1 mutants exhibited a smaller cell size. The altered cell cycle progression correlates with altered expression of the G1 cyclins Cln3 and Pcl2 in hog1 cells compared to the wild type strain. In addition, Hgc1 (a hypha-specific G1 cyclin) as well as Cln3 displayed a different kinetics of expression in the presence of hydrogen peroxide in hog1 mutants. Collectively, these results indicate that Hog1 regulates the expression of G1 cyclins not only in response to oxidative stress, but also under standard growth conditions. Hydrogen peroxide treated cells did not show fluctuations in the mRNA levels for SOL1, which are observed in untreated cells during cell cycle progression. In addition, treatment with hydrogen peroxide prevented degradation of Sol1, an effect which was enhanced in hog1 mutants. Therefore, in C. albicans, the MAPK Hog1 mediates cell cycle progression in response to oxidative

  16. THE DECOMPOSITION OF HYDROGEN PEROXIDE BY LIVER CATALASE

    PubMed Central

    Williams, John

    1928-01-01

    1. The velocity of decomposition of hydrogen peroxide by catalase as a function of (a) concentration of catalase, (b) concentration of hydrogen peroxide, (c) hydrogen ion concentration, (d) temperature has been studied in an attempt to correlate these variables as far as possible. It is concluded that the reaction involves primarily adsorption of hydrogen peroxide at the catalase surface. 2. The decomposition of hydrogen peroxide by catalase is regarded as involving two reactions, namely, the catalytic decomposition of hydrogen peroxide, which is a maximum at the optimum pH 6.8 to 7.0, and the "induced inactivation" of catalase by the "nascent" oxygen produced by the hydrogen peroxide and still adhering to the catalase surface. This differs from the more generally accepted view, namely that the induced inactivation is due to the H2O2 itself. On the basis of the above view, a new interpretation is given to the equation of Yamasaki and the connection between the equations of Yamasaki and of Northrop is pointed out. It is shown that the velocity of induced inactivation is a minimum at the pH which is optimal for the decomposition of hydrogen peroxide. 3. The critical increment of the catalytic decomposition of hydrogen peroxide by catalase is of the order 3000 calories. The critical increment of induced inactivation is low in dilute hydrogen peroxide solutions but increases to a value of 30,000 calories in concentrated solutions of peroxide. PMID:19872400

  17. 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.

  18. 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...

  19. 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...

  20. 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...

  1. Copper inhibition of hydrogen peroxide-induced hypertrophy in embryonic rat cardiac H9c2 cells.

    PubMed

    Zhou, Yang; Jiang, Youchun; Kang, Y James

    2007-03-01

    Previous studies have shown that dietary copper deficiency causes cardiac hypertrophy and depression of vascular epithelial growth factor (VEGF) expression in mouse model. Copper replenishment in the diet reverses cardiac hypertrophy and restores VEGF expression. The present study was undertaken to specifically determine the role of VEGF in copper effect on cell hypertrophy. Embryonic rat cardiac H9c2 cells were exposed to hydrogen peroxide to develop hypertrophy, determined by increases in cell size and total protein content. Copper addition at 5 microM in cultures suppressed cell hypertrophy. In the presence of anti-VEGF antibody, copper inhibitory effect on cell hypertrophy was blunted, and VEGF alone mimicked the inhibitory effect of copper. The results thus demonstrated that VEGF is critically involved in copper inhibition of cell hypertrophy induced by hydrogen peroxide in the H9c2 cells.

  2. 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.

  3. Hydrogen peroxide pre-treatment induces salt-stress acclimation in maize plants.

    PubMed

    de Azevedo Neto, André Dias; Prisco, José Tarquinio; Enéas-Filho, Joaquim; Medeiros, Jand-Venes Rolim; Gomes-Filho, Enéas

    2005-10-01

    The effect of exogenously applied H2O2 on salt stress acclimation was studied with regard to plant growth, lipid peroxidation, and activity of antioxidative enzymes in leaves and roots of a salt-sensitive maize genotype. Pre-treatment by addition of 1 microM H2O2 to the hydroponic solution for 2 days induced an increase in salt tolerance during subsequent exposure to salt stress. This was evidenced by plant growth, lipid peroxidation and antioxidative enzymes measurements. In both leaves and roots the variations in lipid peroxidation and antioxidative enzymes (superoxide dismutase, ascorbate peroxidase, guaiacol peroxidase, glutathione reductase, and catalase) activities of both acclimated and unacclimated plants, suggest that differences in the antioxidative enzyme activities may, at least in part, explain the increased tolerance of acclimated plants to salt stress, and that H2O2 metabolism is involved as signal in the processes of maize salt acclimation.

  4. 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.

  5. 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.

  6. 8-Alkylcoumarins from the Fruits of Cnidium monnieri Protect against Hydrogen Peroxide Induced Oxidative Stress Damage

    PubMed Central

    Chang, Chi-I; Hu, Wan-Chiao; Shen, Che-Piao; Hsu, Ban-Dar; Lin, Wei-Yong; Sung, Ping-Jyun; Wang, Wei-Hsien; Wu, Jin-Bin; Kuo, Yueh-Hsiung

    2014-01-01

    Three new 8-alkylcoumarins, 7-O-methylphellodenol-B (1), 7-methoxy-8-(3-methyl-2,3-epoxy-1-oxobutyl)chromen-2-one (2), and 3′-O-methylvaginol (3), together with seven known compounds (4–10) were isolated from the fruits of Cnidium monnieri. Their structures were determined by detailed analysis of spectroscopic data and comparison with the data of known analogues. All the isolates were evaluated the cytoprotective activity by MTS cell proliferation assay and the results showed that all the three new 8-alkylcoumarins exhibited cytoprotective effect on Neuro-2a neuroblastoma cells injured by hydrogen peroxide. PMID:24642881

  7. Protective effect of medicinal fungus Xylaria nigripes mycelia extracts against hydrogen peroxide-induced apoptosis in PC12 cells.

    PubMed

    Divate, Rupesh D; Wang, Pei-Ming; Wang, Chiun-Chuang; Chou, Su-Tze; Chang, Chen-Tien; Chung, Yun-Chin

    2017-03-01

    Xylaria nigripes ( XN) is a medicinal fungus that was used traditionally as a diuretic, nerve tonic, and for treating insomnia and trauma. In this study, we elucidated possible mechanisms of neuroprotective effects of XN mycelia extracts. XN mycelia were produced by fermentation. Hot water extract and 70% ethanol extract of XN mycelia were evaluated on hydrogen peroxide (H2O2)-induced apoptosis in PC12, a rat pheochromocytoma cell line. Both XN extracts effectively protected PC12 cells against H2O2-induced cell damage by inhibiting release of lactate dehydrogenase, decreasing DNA damage, restoring mitochondrial membrane potential, and arresting abnormal apoptosis through upregulation of Bcl-2 and downregulation of Bax and caspase 3. Compared to water extract, ethanol extract showed not only greater neuroprotective effects but also a higher antioxidant activity by scavenging DPPH radicals, inhibiting lipid peroxidation, and reducing power. High phenolic content and antioxidant activity may provide the neuroprotective properties of XN ethanol extract.

  8. 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

  9. 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.

  10. 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.

  11. 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,...

  12. 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.…

  13. 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,...

  14. 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,...

  15. 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,...

  16. 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,...

  17. 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

  18. 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.

  19. Titanium-doped cerium oxide nanoparticles protect cells from hydrogen peroxide-induced apoptosis

    NASA Astrophysics Data System (ADS)

    Clark, Andrea; Zhu, Aiping; Petty, Howard R.

    2013-12-01

    To develop new nanoparticle materials possessing antioxidative capacity with improved physical characteristics, we have studied titanium-doped cerium oxide (CeTiO2) nanoparticles. CeTiO2 nanoparticles had mode diameters in the range of 15-20 nm. These nanoparticles demonstrated catalase activity, and did not promote the activation of hemolytic or cytolytic pathways in living cells. Using surface plasmon resonance-enhanced microscopy, we find that these nanoparticles associate with cells. Transmission electron microscopy studies demonstrated that these nanoparticles accumulate within the vacuolar compartment of cells. Importantly, CeTiO2 nanoparticles decrease hydrogen peroxide-mediated apoptosis of cells as judged by the reduced cleavage of a caspase 3-sensitive label. CeTiO2 nanoparticles may contribute to deflecting tissue damage in a broad spectrum of oxidant-mediated diseases, such as macular degeneration and Alzheimer's disease.

  20. Titanium-doped cerium oxide nanoparticles protect cells from hydrogen peroxide-induced apoptosis

    PubMed Central

    Clark, Andrea; Zhu, Aiping; Petty, Howard R.

    2014-01-01

    To develop new nanoparticle materials possessing anti-oxidative capacity with improved physical characteristics, we have studied titanium-doped cerium oxide (CeTiO2) nanoparticles. CeTiO2 nanoparticles had a mode diameter of 15-20 nm. These nanoparticles demonstrated catalase activity, and did not promote the activation of hemolytic or cytolytic pathways in living cells. Using surface plasmon resonance enhanced microscopy, we find that these nanoparticles associate with cells. Transmission electron microscopy studies demonstrated that these nanoparticles accumulate within the vacuolar compartment of cells. Importantly, CeTiO2 nanoparticles decrease hydrogen peroxide-mediated apoptosis of cells as judged by the reduced cleavage of a caspase 3-sensitive label. CeTiO2 nanoparticles may contribute to deflecting tissue damage in a broad spectrum of oxidant-mediated diseases, such as macular degeneration and Alzheimer's disease. PMID:24791147

  1. Method for detection of hydrogen peroxide in HT22 cells

    PubMed Central

    Jacewicz, Dagmara; Siedlecka-Kroplewska, Kamila; Drzeżdżon, Joanna; Piotrowska, Agnieszka; Wyrzykowski, Dariusz; Tesmar, Aleksandra; Żamojć, Krzysztof; Chmurzyński, Lech

    2017-01-01

    We have proposed a new method which can be applied in assessing the intracellular production of hydrogen peroxide. Using this assay we have examined the hydrogen peroxide generation during the L-glutamate induced oxidative stress in the HT22 hippocampal cells. The detection of hydrogen peroxide is based on two crucial reagents cis-[Cr(C2O4)(pm)(OH2)2]+ (pm denotes pyridoxamine) and 2-ketobutyrate. The results obtained indicate that the presented method can be a promising tool to detect hydrogen peroxide in biological samples, particularly in cellular experimental models. PMID:28358356

  2. Skeletal muscle contractions induce acute changes in cytosolic superoxide, but slower responses in mitochondrial superoxide and cellular hydrogen peroxide.

    PubMed

    Pearson, Timothy; Kabayo, Tabitha; Ng, Rainer; Chamberlain, Jeffrey; McArdle, Anne; Jackson, Malcolm J

    2014-01-01

    Skeletal muscle generation of reactive oxygen species (ROS) is increased following contractile activity and these species interact with multiple signaling pathways to mediate adaptations to contractions. The sources and time course of the increase in ROS during contractions remain undefined. Confocal microscopy with specific fluorescent probes was used to compare the activities of superoxide in mitochondria and cytosol and the hydrogen peroxide content of the cytosol in isolated single mature skeletal muscle (flexor digitorum brevis) fibers prior to, during, and after electrically stimulated contractions. Superoxide in mitochondria and cytoplasm were assessed using MitoSox red and dihydroethidium (DHE) respectively. The product of superoxide with DHE, 2-hydroxyethidium (2-HE) was acutely increased in the fiber cytosol by contractions, whereas hydroxy-MitoSox showed a slow cumulative increase. Inhibition of nitric oxide synthases increased the contraction-induced formation of hydroxy-MitoSox only with no effect on 2-HE formation. These data indicate that the acute increases in cytosolic superoxide induced by contractions are not derived from mitochondria. Data also indicate that, in muscle mitochondria, nitric oxide (NO) reduces the availability of superoxide, but no effect of NO on cytosolic superoxide availability was detected. To determine the relationship of changes in superoxide to hydrogen peroxide, an alternative specific approach was used where fibers were transduced using an adeno-associated viral vector to express the hydrogen peroxide probe, HyPer within the cytoplasmic compartment. HyPer fluorescence was significantly increased in fibers following contractions, but surprisingly followed a relatively slow time course that did not appear directly related to cytosolic superoxide. These data demonstrate for the first time temporal and site specific differences in specific ROS that occur in skeletal muscle fibers during and after contractile activity.

  3. Hydrogen peroxide production and mitochondrial dysfunction contribute to the fusaric acid-induced programmed cell death in tobacco cells.

    PubMed

    Jiao, Jiao; Sun, Ling; Zhou, Benguo; Gao, Zhengliang; Hao, Yu; Zhu, Xiaoping; Liang, Yuancun

    2014-08-15

    Fusaric acid (FA), a non-specific toxin produced mainly by Fusarium spp., can cause programmed cell death (PCD) in tobacco suspension cells. The mechanism underlying the FA-induced PCD was not well understood. In this study, we analyzed the roles of hydrogen peroxide (H2O2) and mitochondrial function in the FA-induced PCD. Tobacco suspension cells were treated with 100 μM FA and then analyzed for H2O2 accumulation and mitochondrial functions. Here we demonstrate that cells undergoing FA-induced PCD exhibited H2O2 production, lipid peroxidation, and a decrease of the catalase and ascorbate peroxidase activities. Pre-treatment of tobacco suspension cells with antioxidant ascorbic acid and NADPH oxidase inhibitor diphenyl iodonium significantly reduced the rate of FA-induced cell death as well as the caspase-3-like protease activity. Moreover, FA treatment of tobacco cells decreased the mitochondrial membrane potential and ATP content. Oligomycin and cyclosporine A, inhibitors of the mitochondrial ATP synthase and the mitochondrial permeability transition pore, respectively, could also reduce the rate of FA-induced cell death significantly. Taken together, the results presented in this paper demonstrate that H2O2 accumulation and mitochondrial dysfunction are the crucial events during the FA-induced PCD in tobacco suspension cells.

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

    PubMed

    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.

  5. 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.

  6. Detection of hydrogen peroxide with chemiluminescent micelles.

    PubMed

    Lee, Dongwon; Erigala, Venkata R; Dasari, Madhuri; Yu, Junhua; Dickson, Robert M; Murthy, Niren

    2008-01-01

    The overproduction of hydrogen peroxide is implicated in the progress of numerous life-threatening diseases and there is a great need for the development of contrast agents that can detect hydrogen peroxide in vivo. In this communication, we present a new contrast agent for hydrogen peroxide, termed peroxalate micelles, which detect hydrogen peroxide through chemiluminescence, and have the physical/chemical properties needed for in vivo imaging applications. The peroxalate micelles are composed of amphiphilic peroxalate based copolymers and the fluorescent dye rubrene, they have a 'stealth' polyethylene glycol (PEG) corona to evade macrophage phagocytosis, and a diameter of 33 nm to enhance extravasation into permeable tissues. The peroxalate micelles can detect nanomolar concentrations of hydrogen peroxide (>50 nM) and thus have the sensitivity needed to detect physiological concentrations of hydrogen peroxide. We anticipate numerous applications of the peroxalate micelles for in vivo imaging of hydrogen peroxide, given their high sensitivity, small size, and biocompatible PEG corona.

  7. 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.

  8. Occupational skin injury by hydrogen peroxide.

    PubMed

    Izu, K; Yamamoto, O; Asahi, M

    2000-01-01

    Hydrogen peroxide is widely used in products such as rocket fuel, bleaching preparations and topical disinfectants. Contact of hydrogen peroxide with the skin can cause severe skin damage. In this report, we describe a case of skin injury induced by hydrogen peroxide. The patient was a 34-year-old man working in a dry cleaning shop. While he was pouring 35% hydrogen peroxide, some of it accidentally splashed over his left shoulder and back, and then an erythema, purpura and vacuolar eruption, similar to bubble wrap, appeared on his left shoulder and down the left side of his back. Histologically, numerous vacuolar structures were observed in the epidermis, dermis and subcutaneous tissue. Coupled with the clinical features, these vacuolar structures were considered as 'oxygen bubbles'. Subcutaneous emphysema was detected by chest X-ray examination. All skin eruptions rapidly healed without scarring by using a steroid ointment. As far as we know, this is the first time such clinical and histological features have been described

  9. Characterization of the neuroprotective effects of estrogens on hydrogen peroxide-induced cell death in hippocampal HT22 cells: time and dose-dependency.

    PubMed

    Vedder, H; Teepker, M; Fischer, S; Krieg, J C

    2000-01-01

    Time and dose-dependency of the effects of estrogens (17-beta estradiol, estrone) and non-estrogenic steroids (progesterone, dexamethasone and methylprednisolone) on the toxicity of hydrogen peroxide were examined in mouse hippocampal HT22 cells. Hydrogen peroxide, an important intermediate of various disease-relevant oxidative stressors, induced cell death in HT22 cells in extracellular concentrations between 0.5 and 1.5 mM in a dose-dependent manner (EC50=0.95 mM). Regarding the underlying mechanisms of toxicity, incubation with hydrogen peroxide did not induce lipid peroxidation in living HT22 cells under these conditions. After preincubation with estrogens and non-estrogenic steroids for 22 hours, estrogen compounds protected the cells against hydrogen peroxide toxicity. Estrogens showed a maximal protective effect at 60-70% of hydrogen peroxide toxicity which diminished at higher and lower concentrations of the toxic challenge. Dose-dependency studies of estrogens revealed that concentrations of 1 microM already exerted a significant cytoprotective effect. Co- and postincubation with 17-beta estradiol and estrone also resulted in significant cell protection even if the estrogens were added 30 min after the initiation of the challenge with hydrogen peroxide. In contrast, preincubation with other steroids like progesterone, a physiological gonadal steroid, dexamethasone, a synthetic glucocorticoid and methylprednisolone, a glucocorticoid with radical scavenging properties, did not protect the cells against hydrogen peroxide toxicity but resulted in a dose-related decrease of HT22 cell survival in the course of the toxic challenge.

  10. Hydrogen peroxide and organic peroxides in the marine environment

    NASA Astrophysics Data System (ADS)

    Heikes, Brian G.; Miller, William L.; Lee, Meehye

    1991-05-01

    Aqueous fluorescence and chemiluminescence methods have been used to measure hydrogen peroxide in natural waters and in the atmosphere. Ambient hydrogen peroxide and soluble organic peroxide data is presented from the EMEX, MLOPEX and SAGA-3 experimental programs, experiments conducted in the remote marine environment. Methods to measure organic peroxide using conventional collection strategies and direct analysis by chemiluminescence or fluorescence method is approximately two orders of magnitude more sensitive than the fluorescence method. Species specific measurements of organic peroxides are also in development using high pressure liquid chromatography (HPLC) and fluorescence or chemiluminescence detection.

  11. 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

  12. Hydrogen peroxide induces apoptosis in cerebral vascular smooth muscle cells: possible relation to neurodegenerative diseases and strokes.

    PubMed

    Li, Jianfeng; Li, Wenyan; Su, Jialin; Liu, Weimin; Altura, Bella T; Altura, Burton M

    2003-12-15

    Recently, reactive oxygen species (ROS) have been suggested as important mediators of brain damage in a number of disease states, including traumatic brain injury, neurodegenerative diseases and strokes. Apoptosis has been suggested to play an important role in neurodegenerative diseases, traumatic brain injury and strokes. The aim of this study was to determine whether or not cerebral vascular smooth muscle cells (CVSMCs) undergo apoptosis following treatment with hydrogen peroxide (H2O2). Herein, we demonstrate, for the first time, that H2O2 can induce apoptosis in a concentration-dependent manner in primary cultured CVSMCs, as measured by several morphological and biochemical criteria. H2O2-induced apoptosis may be initiated by stimulating Ca2+-dependent endonuclease activity. The present new data suggest that apoptosis in cerebral VSMCs, induced by ROS, such as H2O2, could play important roles in neruodegenerative processes, traumatic brain injury and strokes.

  13. Carvedilol protects bone marrow stem cells against hydrogen peroxide-induced cell death via PI3K-AKT pathway.

    PubMed

    Chen, Meihui; Chen, Shudong; Lin, Dingkun

    2016-03-01

    Carvedilol, a nonselective β-adrenergic receptor blocker, has been reported to exert potent anti-oxidative activities. In the present study, we aimed to investigate the effects of carvedilol against hydrogen peroxide (H2O2)-induced bone marrow-derived mesenchymal stem cells (BMSCs) death, which imitate the microenvironment surrounding transplanted cells in the injured spinal cord in vitro. Carvedilol significantly reduced H2O2-induced reactive oxygen species production, apoptosis and subsequent cell death. LY294002, the PI3K inhibitor, blocked the protective effects and up-regulation of Akt phosphorylation of carvedilol. Together, our results showed that carvedilol protects H2O2-induced BMSCs cell death partly through PI3K-Akt pathway, suggesting carvedilol could be used in combination with BMSCs for the treatment of spinal cord injury by improving the cell survival and oxidative stress microenvironments.

  14. Hydroxyl radical consumption following photolysis of vapor-phase hydrogen peroxide at 266 nm: Implications for photofragmentation laser-induced fluorescence measurements of hydrogen peroxide

    NASA Astrophysics Data System (ADS)

    Johansson, O.; Bood, J.; Aldén, M.; Lindblad, U.

    2009-10-01

    The decay of OH concentration following photolysis of room-temperature vapor-phase hydrogen peroxide is studied as a function of photolysis fluence at 266 nm in an open air environment. The rate of decay is found to increase with increasing photolysis fluence, i.e., with increasing number of photodissociated H2O2(g) molecules. Single-exponential functions approximate the OH concentration decay rather well, even for higher photolysis levels, and the decay time is shown to be inversely proportional to the H2O2(g) concentration. For fluences of about 450 mJ/cm2 the difference between a single-exponential decay and measured data is becoming evident after approximately 150 μs. Calculations based on a chemical kinetics model agree well with experimental data also for times >150 μs. By combining the model with measurements, the actual photolysis levels used in experiments are estimated. The best fit between measured data and the model suggests that about 1.1% of the H2O2(g) molecules are dissociated with a photolysis fluence of ˜450 mJ/cm2, in reasonable agreement with a Beer-Lambert based estimation. Excitation scans did not unfold any differences between OH spectra recorded at different photolysis fluences.

  15. 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

  16. Astaxanthin protects steroidogenesis from hydrogen peroxide-induced oxidative stress in mouse Leydig cells.

    PubMed

    Wang, Jyun-Yuan; Lee, Yue-Jia; Chou, Mei-Chia; Chang, Renin; Chiu, Chih-Hsien; Liang, Yao-Jen; Wu, Leang-Shin

    2015-03-16

    Androgens, especially testosterone produced in Leydig cells, play an essential role in development of the male reproductive phenotype and fertility. However, testicular oxidative stress may cause a decline in testosterone production. Many antioxidants have been used as reactive oxygen species (ROS) scavengers to eliminate oxidative stress to protect steroidogenesis. Astaxanthin (AST), a natural extract from algae and plants ubiquitous in the marine environment, has been shown to have antioxidant activity in many previous studies. In this study, we treated primary mouse Leydig cells or MA-10 cells with hydrogen peroxide (H2O2) to cause oxidative stress. Testosterone and progesterone production was suppressed and the expression of the mature (30 kDa) form of StAR protein was down-regulated in MA-10 cells by H2O2 and cAMP co-treatment. However, progesterone production and expression of mature StAR protein were restored in MA-10 cells by a one-hour pretreatment with AST. AST also reduced ROS levels in cells so that they were lower than the levels in untreated controls. These results provide additional evidence of the potential health benefits of AST as a potential food additive to ease oxidative stress.

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

    PubMed

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

    2013-05-09

    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.

  18. Protective Effect of Quercetin on the Development of Preimplantation Mouse Embryos against Hydrogen Peroxide-Induced Oxidative Injury

    PubMed Central

    Zhang, Qin-hua; Yan, Zhi-guang; Liang, Hong-xing; Chai, Wei-ran; Yan, Zheng; Kuang, Yan-ping; Qi, Cong

    2014-01-01

    Quercetin, a plant-derived flavonoid in Chinese herbs, fruits and wine, displays antioxidant properties in many pathological processes associated with oxidative stress. However, the effect of quercetin on the development of preimplantation embryos under oxidative stress is unclear. The present study sought to determine the protective effect and underlying mechanism of action of quercetin against hydrogen peroxide (H2O2)-induced oxidative injury in mouse zygotes. H2O2 treatment impaired the development of mouse zygotes in vitro, decreasing the rates of blastocyst formation and hatched, and increasing the fragmentation, apoptosis and retardation in blastocysts. Quercetin strongly protected zygotes from H2O2-induced oxidative injury by decreasing the reactive oxygen species level, maintaining mitochondrial function and modulating total antioxidant capability, the activity of the enzymatic antioxidants, including glutathione peroxidase and catalase activity to keep the cellular redox environment. Additionally, quercetin had no effect on the level of glutathione, the main non-enzymatic antioxidant in embryos. PMID:24586844

  19. 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.

  20. 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.

  1. 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.

  2. Streptococcus sanguinis induces neutrophil cell death by production of hydrogen peroxide

    PubMed Central

    Sumioka, Ryuichi; Nakata, Masanobu; Okahashi, Nobuo; Li, Yixuan; Wada, Satoshi; Yamaguchi, Masaya; Sumitomo, Tomoko; Hayashi, Mikako; Kawabata, Shigetada

    2017-01-01

    Streptococcus is the dominant bacterial genus in the human oral cavity and a leading cause of infective endocarditis. Streptococcus sanguinis belongs to the mitis group of streptococci and produces hydrogen peroxide (H2O2) by the action of SpxB, a pyruvate oxidase. In this study, we investigated the involvement of SpxB in survival of S. sanguinis in human blood and whether bacterial H2O2 exhibits cytotoxicity against human neutrophils. Results of a bactericidal test with human whole blood revealed that the spxB mutation in S. sanguinis is detrimental to its survival in blood. When S. sanguinis strains were exposed to isolated neutrophils, the bacterial survival rate was significantly decreased by spxB deletion. Furthermore, human neutrophils exposed to the S. sanguinis wild-type strain, in contrast to those exposed to an spxB mutant strain, underwent cell death with chromatin de-condensation and release of web-like extracellular DNA, reflecting induction of neutrophil extracellular traps (NETs). Since reactive oxygen species-mediated NET induction requires citrullination of arginine residues in histone proteins and subsequent chromatin de-condensation, we examined citrullination levels of histone in infected neutrophils. It is important to note that the citrullinated histone H3 was readily detected in neutrophils infected with the wild-type strain, as compared to infection with the spxB mutant strain. Moreover, decomposition of streptococcal H2O2 with catalase reduced NET induction. These results suggest that H2O2 produced by S. sanguinis provokes cell death of neutrophils and NET formation, thus potentially affecting bacterial survival in the bloodstream. PMID:28222125

  3. 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.

  4. 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.

  5. 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.

  6. Hydrogen peroxide on the surface of Europa

    USGS Publications Warehouse

    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.

  7. 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.

  8. Constituents from the stem barks of Canarium bengalense with cytoprotective activity against hydrogen peroxide-induced hepatotoxicity.

    PubMed

    Le, Hoang Thi; Ha, Do Thi; Minh, Chau Thi Anh; Kim, Tae Hoon; Van Kiem, Phan; Thuan, Nguyen Duy; Na, Minkyun

    2012-01-01

    Phytochemical investigation of the stem barks of Canarium bengalense (Burseraceace) resulted in the isolation of a new flavone glycoside (5) together with six known compounds (1-4, 6, and 7). The chemical structure of the new compound was elucidated as 3'-hydroxy-7,4'-dimethoxyflavone-5-O-α-L-arabinofuranosyl-(1→6)-β-D-glucopyranoside by means of 1D and 2D NMR ((1)H-(1)H COSY, HMQC, and HMBC) and MS analyses. To evaluate the in vitro cytoprotective effect, the isolates (1-7) were tested against hydrogen peroxide (H(2)O(2))-induced damage in primary cultured hepatocytes. The viability of hepatocytes was increased by treatment with each compound, except compound 1. Compounds 3, 4, and 7 exerted cytoprotective effects comparable to curcumin, the positive control. Our results suggest that the cytoprotective constituents of C. bengalense may contribute to its traditional use in the treatment of tumor and liver damage.

  9. 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.

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

    PubMed

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

    2011-01-01

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

  11. 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

  12. 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.

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  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. 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)

  19. 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...

  20. 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

  1. 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

  2. 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

  3. 3',4',7-Trihydroxyflavone prevents apoptotic cell death in neuronal cells from hydrogen peroxide-induced oxidative stress.

    PubMed

    Kwon, Seung-Hwan; Hong, Sa-Ik; Ma, Shi-Xun; Lee, Seok-Yong; Jang, Choon-Gon

    2015-06-01

    In this study, we investigated the mechanisms of 3',4',7-trihydroxyflavone (THF) protection of neuronal cells from neuronal cell death induced by the oxidative stress-related neurotoxin hydrogen peroxide (H2O2). Pretreatment with THF significantly elevated cell viability, reduced H2O2-induced lactate dehydrogenase (LDH) release, reactive oxygen species (ROS) production, glutathione (GSH) content, superoxide dismutase (SOD) activity, catalase (CAT) activity, and mitochondria membrane potential (MMP) loss. Western blot data demonstrated that THF inhibited the H2O2-induced up- or down-regulation of cleaved caspase-3, cleaved caspase-9, cleaved poly-ADP-ribose polymerase (PARP), Bax, Bcl-2, and Bcl-xL, and attenuated the H2O2-induced release of cytochrome c from the mitochondria to the cytosol. In addition, pretreatment with THF attenuated H2O2-induced rapid and significant phosphorylation of c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), and phosphatidylinositol 3-kinases (PI3K)/Akt. THF also inhibited nuclear factor-κB (NF-κB) translocation to the nucleus induced by H2O2, down-stream of H2O2-induced phosphorylation of MAPKs and PI3K/Akt. These data provide the first evidence that THF protects neuronal cells against H2O2-induced oxidative stress, possibly through ROS reduction, mitochondria protection, and NF-κB modulation via MAPKs and PI3K/Akt pathways. The neuroprotective effects of THF make it a promising candidate as a therapeutic agent for neurodegenerative diseases.

  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. Salvianolic Acid B Inhibits Hydrogen Peroxide-Induced Endothelial Cell Apoptosis through Regulating PI3K/Akt Signaling

    PubMed Central

    Liu, Chen-Li; Xie, Li-Xia; Li, Min; Durairajan, Siva Sundara Kumar; Goto, Shinya; Huang, Jian-Dong

    2007-01-01

    Background Salvianolic acid B (Sal B) is one of the most bioactive components of Salvia miltiorrhiza, a traditional Chinese herbal medicine that has been commonly used for prevention and treatment of cerebrovascular disorders. However, the mechanism responsible for such protective effects remains largely unknown. It has been considered that cerebral endothelium apoptosis caused by reactive oxygen species including hydrogen peroxide (H2O2) is implicated in the pathogenesis of cerebrovascular disorders. Methodology and Principal Findings By examining the effect of Sal B on H2O2-induced apoptosis in rat cerebral microvascular endothelial cells (rCMECs), we found that Sal B pretreatment significantly attenuated H2O2-induced apoptosis in rCMECs. We next examined the signaling cascade(s) involved in Sal B-mediated anti-apoptotic effects. We showed that H2O2 induces rCMECs apoptosis mainly through the PI3K/ERK pathway, since a PI3K inhibitor (LY294002) blocked ERK activation caused by H2O2 and a specific inhibitor of MEK (U0126) protected cells from apoptosis. On the other hand, blockage of the PI3K/Akt pathway abrogated the protective effect conferred by Sal B and potentated H2O2-induced apoptosis, suggesting that Sal B prevents H2O2-induced apoptosis predominantly through the PI3K/Akt (upstream of ERK) pathway. Significance Our findings provide the first evidence that H2O2 induces rCMECs apoptosis via the PI3K/MEK/ERK pathway and that Sal B protects rCMECs against H2O2-induced apoptosis through the PI3K/Akt/Raf/MEK/ERK pathway. PMID:18091994

  6. Hydrogen peroxide generated by NADPH oxidase is involved in high blue-light-induced chloroplast avoidance movements in Arabidopsis

    NASA Astrophysics Data System (ADS)

    Wen, Feng; Xing, Da; Zhang, Lingrui

    2009-08-01

    One of the most important functions of blue light is to induce chloroplast movements by reducing the damage to photosynthetic machinery under excess light. Hydrogen peroxide (H2O2), generated by various environmental stimuli, can act as a signaling molecule that regulates a number of developmental processes and environmental responses. To investigate whether H2O2 is involved in high blue light-induced chloroplast avoidance movements, we use luminescence spectrometer to observe H2O2 generation with the assistance of the fluorescence probe dichlorofluorescin diacetate (H2DCF-DA). After treatment with high blue light, a large quantity of H2O2 indicated by the fluorescence intensity of DCF is produced in a dose-dependent manner in leaf strip of Arabidopsis. Enzymatic assay shows that the activity of NADPH oxidase, which is a major site for H2O2 generation, also rapidly increases in treated strips. Exogenously applied H2O2 can promote the high blue light-induced chloroplast movements. Moreover, high blue light-induced H2O2 generation can be abolished completely by addition of exogenous catalase (CAT), and partly by diphenylene iodonium (DPI) and dichlorophenyl dimethylurea (DCMU), which are an NADPH oxidase inhibitor and a blocker of electron transport chain. And subsequent chloroplast movements can be abolished by CAT and DPI, but not by DCMU. These results presented here suggested that high blue light can induce oxidative burst, and NADPH oxidase as a major producer for H2O2 is involved in blue light-induced chloroplast avoidance movements.

  7. 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

  8. Neuroprotective effects of germinated brown rice against hydrogen peroxide induced cell death in human SH-SY5Y cells.

    PubMed

    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 (H(2)O(2)) in human neuroblastoma SH-SY5Y cells have been investigated. Results show that GBR suppressed H(2)O(2)-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.

  9. Effects of phenolics in Empire apples on hydrogen peroxide-induced inhibition of gap-junctional intercellular communication.

    PubMed

    Lee, Ki Won; Lee, Sang Jun; Kang, Nam Joo; Lee, Chang Yong; Lee, Hyong Joo

    2004-01-01

    The present study investigated antioxidant and antitumor-promoting activities of major phenolic phytochemicals of apples. The contents of each antioxidant in Empire apples was quantified and their contributions to total antioxidant activity of apples were determined using assay for inhibition of 12-O-tetradecanoylphorbol-13-acetate-induced superoxide radical generation in cell culture model and expressed in vitamin C equivalent antioxidant capacity (VCEAC). The estimated contribution of major phenolics and vitamin C to total anitoxidant capacity of 100 g fresh Empire apples is as follows: quercetin (60.05 VCEAC) > chlorogenic acid (12.32) > phloretin (7.41) > procyanidin B2 (7.22) > vitamin C (6.61) > epicatechin (5.10) in superoxide radical scavenging assay. Recent reports suggest that the mechanism of carcinogenic process of hydrogen peroxide (H2O2) may be associated with the inhibition of gap-junctional intercellular communication (GJIC), which is involved in tumor promotion process. Apple extracts showed the protective effects against the inhibition of GJIC by H2O2 in a dose-dependent manner. Quercetin exerted the strongest protective effects among major antioxidants in apples on H2O2-induced inhibition of GJIC, following epicatechin, procyanidin B2, and vitamin C, while chlorogenic acid and phloretin had no effects. Our results indicate that cancer chemopreventive activity of apples is associated with the combined antioxidant capacity and antitumor-promoting activities of diverse antioxidants.

  10. Excess copper induces accumulation of hydrogen peroxide and increases lipid peroxidation and total activity of copper-zinc superoxide dismutase in roots of Elsholtzia haichowensis.

    PubMed

    Zhang, Hongxiao; Xia, Yan; Wang, Guiping; Shen, Zhenguo

    2008-01-01

    The effects of excess copper (Cu) on the accumulation of hydrogen peroxide (H2O2) and antioxidant enzyme activities in roots of the Cu accumulator Elsholtzia haichowensis Sun were investigated. Copper at 100 and 300 microM significantly increased the concentrations of malondialdehyde and H2O2, and the activities of catalase (E.C. 1.11.1.6), ascorbate peroxidase (E.C. 1.11.1.11), guaiacol peroxidase (GPOD, E.C. 1.11.1.7) and superoxide dismutase (SOD, E.C. 1.15.1.1). Isoenzyme pattern and inhibitor studies showed that, among SOD isoforms, only copper-zinc superoxide dismutase (CuZn-SOD) increased. Excess Cu greatly increased the accumulation of superoxide anion (O2 (.-)) and H2O2 in E. haichowensis roots. This study also provides the first cytochemical evidence of an accumulation of H2O2 in the root cell walls as a consequence of Cu treatments. Experiments with diphenyleneiodonium as an inhibitor of NADPH oxidase, 1,2-dihydroxybenzene-3,5-disulphonic acid as an O2 (.-) scavenger, and N-N-diethyldithiocarbamate as an inhibitor of SOD showed that the source of H2O2 in the cell walls could partially be NADPH oxidase. The enzyme can use cytosolic NADPH to produce O2 (.-), which rapidly dismutates to H2O2 by SOD. Apoplastic GPOD and CuZn-SOD activities were induced in roots of E. haichowensis with 100 microM Cu suggesting that these two antioxidant enzymes may be responsible for H2O2 accumulation in the root apoplast.

  11. 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.

  12. Protective effects of farrerol against hydrogen-peroxide-induced apoptosis in human endothelium-derived EA.hy926 cells.

    PubMed

    Li, Jian-Kuan; Ge, Rui; Tang, Li; Li, Qing-Shan

    2013-09-01

    Vascular endothelium plays an important role in the physiological homeostasis of blood vessels. Endothelial injury is considered to be implicated in the pathogenesis of many cardiovascular diseases, including atherosclerosis. Farrerol, a flavonoid considered to be the major bioactive component in a traditional Chinese herb, "Man-shan-hong", which is the dried leaves of Rhododendron dauricum L., displays many bioactive properties, including antibechic, antibacterial, anti-inflammatory, and the inhibition of vascular smooth muscle cell (VSMC) proliferation. In this study, the protective effects of farrerol on hydrogen peroxide (H2O2)-induced apoptosis in human endothelium-derived EA.hy926 cells were investigated. The results showed that farrerol significantly inhibited the loss of cell viability and enhanced superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in H2O2-induced EA.hy926 cells. Meanwhile, farrerol inhibited H2O2-induced elevation in the levels of intracellular malondialdehyde and reactive oxygen species, as well as cell apoptosis. Furthermore, real time RT-PCR and Western blot analysis showed that farrerol significantly decreased the expression of Bax mRNA, Bax, cleaved caspase-3, and phosph-p38 MAPK, while increasing the exporession of Bcl-2 mRNA and Bcl-2 in H2O2-induced EA.hy926 cells. These results are the first demonstration that farrerol has protective effects against H2O2-induced apoptosis in EA.hy926 cells, and suggests that farrerol is a potential candidate for the intervention of endothelial-injury-associated cardiovascular diseases.

  13. 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.

  14. No protective effect of curcumin on hydrogen peroxide-induced cytotoxicity in HepG2 cells.

    PubMed

    Chen, Xiuping; Zhong, Zhangfeng; Xu, Zengtao; Chen, Lidian; Wang, Yitao

    2011-01-01

    Scavenging of intracellular reactive oxygen species (ROS) is one of the potential mechanisms contributing to the protective effects of many antioxidants. Curcumin, a natural product, is an effective ROS scavenger. However, the role of its ROS scavenging ability in its cytoprotective action remains to be clarified. Herein, the protective effects of curcumin on hydrogen peroxide (H₂O₂)- and tert-butyl hydroperoxide-induced ROS formation and HepG2 cell injury were determined. HepG2 cells were pretreated with curcumin for 30 min and then treated with H₂O₂ (500 μM) or tert-butyl hydroperoxide (200 μM) for 24 h. Curcumin pretreatment dramatically decreased H₂O₂- and tert-butyl hydroperoxide-induced ROS production, but failed to suppress cytotoxicity of those compounds. H₂O₂ induced decreases in mitochondrial membrane potential (ΔΨm) and increases in DNA fragmentation could not be reversed by curcumin. Furthermore, curcumin enhanced expression of H₂O₂-induced pro-apoptotic protein Bax expression and inhibited expression of anti-apoptotic proteins Bcl-2 and Bcl-xL. In addition, curcumin significantly decreased p38MAPK and phospho-CDC-2 protein expression and increased phospho-p38MAPK, p42/44MAPK, and phospho-p42/44MAPK protein expression. These results suggest that short pretreatment and subsequent longer co-treatment of low concentrations of curcumin showed no obvious protective effect on H₂O₂-induced HepG₂ cell injury.

  15. 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.

  16. 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.

  17. Oxidative stress response of filamentous fungi induced by hydrogen peroxide and paraquat.

    PubMed

    Angelova, Maria B; Pashova, Svetlana B; Spasova, Boryana K; Vassilev, Spassen V; Slokoska, Lyudmila S

    2005-02-01

    Although, oxidative stress response, which protects organisms from deleterious effects of reactive oxygen species (ROS), has been extensively studied in pro- and eukaryotes, the information about filamentous fungi is fragmentary. We investigated the effect of two ROS-generating agents (paraquat, PQ, and H2O2) on cellular growth and antioxidant enzyme induction in 12 fungal species. Our results indicate that exposure of fungal spores or mycelia to PQ and H2O2 promoted oxidative stress, as evidenced by remarkable inhibition of spore germination and biomass production; stimulation of cyanide-resistant respiration; accumulation of oxidative modified proteins. Cell responses against both superoxide and peroxide stresses include enhanced expression of superoxide dismutase (SOD) and catalase, however, the extent was different: treatment with PQ increased mainly SOD, whereas exogenous H2O2 led to enhanced catalase. We also found that G6PD has a role in the mechanism of protection against superoxide and peroxide stresses. The activation of antioxidant enzyme defence was blocked by the translation inhibitor, cycloheximide, suggesting that there was de novo enzyme synthesis.

  18. Suppressive effects of genomic imprinted gene PEG10 on hydrogen peroxide-induced apoptosis in L02 cells.

    PubMed

    Liu, Yao; Huang, Huanjun; Lin, Jusheng; Zhang, Qiang; Tan, Jinquan; Ren, Jinghua

    2009-12-01

    The effects of PEG10 on hydrogen peroxide (H2O2)-induced apoptosis in human normal liver cell line L02 were investigated. The PEG10 gene was transfected into L02 cells by lipofectamine, the positive clone was screened by G418 and defined as L02/PEG10, while the cell transfected with empty expression vector (pEGFP-N1) was defined as L02/vector. L02/vector and parental L02 cells served as control. RT-PCR and Western blotting were employed to detect the expression of target genes. H2O2 (50-400 mmol/L) was administered to induce the apoptosis of L02 cells. Cells viability was measured by MTT and the morphological changes of apoptotic cells were determined by fluorescence microscopy using hoechst33342 nuclei staining. DNA fragmentation was observed by agarose gel electrophoresis. PEG10 mRNA and protein levels in L02/PEG10 cells were significantly increased as compared with those in the control cells. After treatment with 400 mmol/L H2O2 for 24 h, the cellular growth inhibition rate of L02/PEG10 cells was significantly lower (58.2%) than that of L02 (92.5%) and L02/vector (88%). Distinct morphological changes characteristic of cell apoptosis such as karyopyknosis and conglomeration were not observed in L02/PEG10. Ladder-like DNA fragmentation in a dose-dependent manner was observed in both L02 and L02/vector cell lines, but not in L02/PEG10. PEG10 over-expression significantly inhibited cytotoxicity induced by H2O2 on human normal liver cell line L02 by antagonizing H2O2-induced apoptosis.

  19. 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

  20. 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.

  1. [Hydrogen peroxide in the troposphere].

    PubMed

    Pehnec, Gordana

    2007-06-01

    The past few decades saw a rising interest in the role of hydrogen peroxide (H2O2) in atmospheric chemistry and its contribution to the formation of free radicals. Free radicals (oxidants) are formed by photochemical reactions between ozone and H2O2. Free radicals formed within cells can oxidise biomolecules, and this may lead to cell death and tissue injury. For this reason, free radicals are believed to cause more than 100 diseases. H2O2 has been suggested as a better indicator of atmospheric oxidation capacity than ozone. Atmospheric H2O2 can appear in the gas phase or in the aqueous phase. It shows typical diurnal and seasonal variations. However, measurements of H2O2 with expensive and sophisticated equipment are rare and limited to but a few sites in the world. Measurements in Greenland ice cores showed that H2O2 concentrations increased over the last 200 years and most of the increase has occurred over the last 20 years. Evaluations show that concentrations will still rise as a result of decreasing SO2 emission. H2O2 measurements have not been carried out in Croatia until now, and, accompanied by the existing longterm measurements of ozone and nitrogen oxides, they will provide an idea of the oxidative capacity of the atmosphere and its influence on oxidative stress.

  2. 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.

  3. 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.

  4. 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

  5. Hydrogen peroxide induces premature acrosome reaction in rat sperm and reduces their penetration of the zona pellucida.

    PubMed

    Hsu, P C; Hsu, C C; Guo, Y L

    1999-11-29

    Recent studies have demonstrated that mammalian sperm are capable of generating reactive oxygen species (ROS) and that this activity is significantly accelerated in subfertile subjects. The observed decrease in penetration of zona-intact oocyte might be explained by chemical-induced ROS-related early onset of capacitation and premature acrosome reaction, but the mechanism is not clear. We determine whether zona-intact oocyte penetration capability in rat epididymal sperm was affected by premature acrosome reaction in rat sperm treated with hydrogen peroxide (H2O2) and calcium ionophore A23187 or H2O2 and lysophosphatidyl choline. Chlortetracycline fluorescence assay was used to study the status of acrosome reaction on epididymal sperm. The sperm-oocyte binding and penetration assay was used to evaluate the capability for zona pellucida penetration. There was a positive linear correlation between the frequency of acrosome-reacted sperm and capability of sperm-oocyte binding and penetration in zona-free oocytes. In the zona-intact oocytes, the sperm-oocyte penetration rate was suppressed as the proportions of acrosome-reacted sperm increased. In summary, this study showed that premature acrosome reaction reduced rat sperm's capability of penetrating zona-intact oocytes. However, this reduction is not seen in zona-free oocytes. These findings may provide a basis for understanding the effects of sperm ROS generation on zona pellucida penetration in male reproductive toxicology.

  6. Hesperidin upregulates heme oxygenase-1 to attenuate hydrogen peroxide-induced cell damage in hepatic L02 cells.

    PubMed

    Chen, Ming-Cang; Ye, Yi-Yi; Ji, Guang; Liu, Jian-Wen

    2010-03-24

    Hesperidin, a naturally occurring flavonoid presents in fruits and vegetables, has been reported to exert a wide range of pharmacological effects that include antioxidant, anti-inflammatory, antihypercholesterolemic, and anticarcinogenic actions. However, the cytoprotection and mechanism of hesperidin to neutralize oxidative stress in human hepatic L02 cells remain unclear. In this work, we assessed the capability of hesperidin to attenuate hydrogen peroxide (H(2)O(2))-induced cell damage by augmenting the cellular antioxidant defense. Real-time quantitative polymerase chain reaction, Western blot, and enzyme activity assay demonstrated that hesperidin upregulated heme oxygenase-1 (HO-1) expression to protect hepatocytes against oxidative stress. In addition, hesperidin also promoted nuclear translocation of nuclear factor erythroid 2-related factor (Nrf2). What's more, hesperidin exhibited activation of extracellular signal-regulated protein kinase 1/2 (ERK1/2). Besides, ERK1/2 inhibitor significantly inhibited hesperidin-mediated HO-1 upregulation and Nrf2 nuclear translocation. Taken together, the above findings suggested that hesperidin augmented cellular antioxidant defense capacity through the induction of HO-1 via ERK/Nrf2 signaling. Therefore, hesperidin has potential as a therapeutic agent in the treatment of oxidative stress-related hepatocyte injury and liver dysfunctions.

  7. Nitric oxide attenuates hydrogen peroxide-induced barrier disruption and protein tyrosine phosphorylation in monolayers of intestinal epithelial cell.

    PubMed

    Katsube, Takanori; Tsuji, Hideo; Onoda, Makoto

    2007-06-01

    The intestinal epithelium provides a barrier to the transport of harmful luminal molecules into the systemic circulation. A dysfunctional epithelial barrier is closely associated with the pathogenesis of a variety of intestinal and systemic disorders. We investigated here the effects of nitric oxide (NO) and hydrogen peroxide (H(2)O(2)) on the barrier function of a human intestinal epithelial cell line, Caco-2. When treated with H(2)O(2), Caco-2 cell monolayers grown on permeable supports exhibited several remarkable features of barrier dysfunction as follows: a decrease in transepithelial electrical resistance, an increase in paracellular permeability to dextran, and a disruption of the intercellular junctional localization of the scaffolding protein ZO-1. In addition, an induction of tyrosine phosphorylation of numerous cellular proteins including ZO-1, E-cadherin, and beta-catenin, components of tight and adherens junctions, was observed. On the other hand, combined treatment of Caco-2 monolayers with H(2)O(2) and an NO donor (NOC5 or NOC12) relieved the damage to the barrier function and suppressed the protein tyrosine phosphorylation induced by H(2)O(2) alone. These results suggest that NO protects the barrier function of intestinal epithelia from oxidative stress by modulating some intracellular signaling pathways of protein tyrosine phosphorylation in epithelial cells.

  8. Involvement of hydrogen peroxide in safingol-induced endonuclease G-mediated apoptosis of squamous cell carcinoma cells.

    PubMed

    Hamada, Masakazu; Wakabayashi, Ken; Masui, Atsushi; Iwai, Soichi; Imai, Tomoaki; Yura, Yoshiaki

    2014-02-17

    Safingol, a L-threo-dihydrosphingosine, induced the nuclear translocation of a mitochondrial apoptogenic mediator--endonuclease G (endo G)--and apoptosis of human oral squamous cell carcinoma (SCC) cells. Upstream mediators remain largely unknown. The levels of hydrogen peroxide (H2O2) in cultured oral SCC cells were measured. Treatment with safingol increased intracellular H2O2 levels but not extracellular H2O2 levels, indicating the production of H2O2. The cell killing effect of safingol and H2O2 was diminished in the presence of reactive oxygen species (ROS) scavenger N-acetyl-L-cysteine (NAC). Dual staining of cells with annexin V and propidium iodide (PI) revealed that apoptotic cell death occurred by treatment with H2O2 and safingol. The number of apoptotic cells was reduced in the presence of NAC. In untreated cells, endo G distributed in the cytoplasm and an association of endo G with mitochondria was observed. After treatment with H2O2 and safingol, endo G was distributed to the nucleus and cytoplasm, indicating the nuclear translocation of the mitochondrial factor. NAC prevented the increase of apoptotic cells and the translocation of endo G. Knock down of endo G diminished the cell killing effect of H2O2 and safingol. These results suggest that H2O2 is involved in the endo G-mediated apoptosis of oral SCC cells by safingol.

  9. Enhanced neuroprotective effects of resveratrol delivered by nanoparticles on hydrogen peroxide-induced oxidative stress in rat cortical cell culture.

    PubMed

    Lu, Xiaowei; Xu, Huae; Sun, Bo; Zhu, Zhenshu; Zheng, Donghui; Li, Xiaolin

    2013-05-06

    Resveratrol (RES) has recently been reported as a potential antioxidant in treatment of ischemia/reperfusion injury through attenuating oxidative stress and apoptosis. However, application of RES is limited for its insolubility and short half-time. Latest evidence raises the possibility of developing nanoparticle-based delivery systems with improved solubility, stability and cytotoxicity of lipophilic drug. Here, we reported first a simple way to produce RES-loaded nanoparticles (RES-NPs) based on poly(N-vinylpyrrolidone)-b-poly(ε-caprolactone) polymer and further evaluated the protective effect of RES-NPs on hydrogen peroxide-induced oxidative stress and apoptosis in rat cortical cell culture. The controlled release pattern of RES-loaded nanoparticles was characterized by in vitro release experiments. Cytotoxicity tests proved cytocompatibility of these nanoparticles with neurons. Shown by coumarin-6 loaded nanoparticles, the uptake of nanoparticles by neurons was considered through endocytosis, which could lead to higher uptake efficiency at lower concentration. Thereby, the hypothesis is raised that RES-NPs could demonstrate enhanced neuroprotection compared to an equivalent dose of free RES at lower concentration, especially. It was further supported by enhanced reduction of LDH release, elimination of ROS and MDA, and attenuation of apoptosis signal (ratio of Bax/Bcl-2, activation of caspase-3). RES-NPs could be a potential treatment needing intensive research for ischemia/reperfusion related disorder including stroke.

  10. 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.

  11. 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.

  12. 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.

  13. The Octadecaneuropeptide ODN Protects Astrocytes against Hydrogen Peroxide-Induced Apoptosis via a PKA/MAPK-Dependent Mechanism

    PubMed Central

    Hamdi, Yosra; Kaddour, Hadhemi; Vaudry, David; Bahdoudi, Seyma; Douiri, Salma; Leprince, Jérôme; Castel, Helene; Vaudry, Hubert; Tonon, Marie-Christine; Amri, Mohamed; Masmoudi-Kouki, Olfa

    2012-01-01

    Astrocytes synthesize and release endozepines, a family of regulatory peptides, including the octadecaneuropeptide (ODN) an endogenous ligand of both central-type benzodiazepine (CBR) and metabotropic receptors. We have recently shown that ODN exerts a protective effect against hydrogen peroxide (H2O2)-induced oxidative stress in astrocytes. The purpose of the present study was to determine the type of receptor and the transduction pathways involved in the protective effect of ODN in cultured rat astrocytes. We have first observed a protective activity of ODN at very low concentrations that was abrogated by the metabotropic ODN receptor antagonist cyclo1–8[DLeu5]OP, but not by the CBR antagonist flumazenil. We have also found that the metabotropic ODN receptor is positively coupled to adenylyl cyclase in astrocytes and that the glioprotective action of ODN upon H2O2-induced astrocyte death is PKA- and MEK-dependent, but PLC/PKC-independent. Downstream of PKA, ODN induced ERK phosphorylation, which in turn activated the expression of the anti-apoptotic gene Bcl-2 and blocked the stimulation by H2O2 of the pro-apoptotic gene Bax. The effect of ODN on the Bax/Bcl-2 balance contributed to abolish the deleterious action of H2O2 on mitochondrial membrane integrity and caspase-3 activation. Finally, the inhibitory effect of ODN on caspase-3 activity was shown to be PKA and MEK-dependent. In conclusion, the present results demonstrate that the potent glioprotective action of ODN against oxidative stress involves the metabotropic ODN receptor coupled to the PKA/ERK-kinase pathway to inhibit caspase-3 activation. PMID:22927932

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

    PubMed Central

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

    2012-01-01

    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 CO2 assimilation, hydrogen peroxide (H2O2) accumulation, and leaf area in cucumber. H2O2 treatment induced increases in CO2 assimilation whilst inhibition of the H2O2 accumulation by its generation inhibitor or scavenger completely abolished EBR-induced CO2 assimilation. Increases of light harvesting due to larger leaf areas in EBR- and H2O2-treated plants were accompanied by increases in the photochemical efficiency of photosystem II (ΦPSII) and photochemical quenching coefficient (q P). EBR and H2O2 both activated carboxylation efficiency of ribulose-1,5-bisphosphate oxygenase/carboxylase (Rubisco) from analysis of CO2 response curve and in vitro measurement of Rubisco activities. Moreover, EBR and H2O2 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 H2O2. However, the effects of EBR on carbohydrate metabolisms were reversed by the H2O2 generation inhibitor diphenyleneodonium (DPI) or scavenger dimethylthiourea (DMTU) pretreatment. All of these results indicate that H2O2 functions as a secondary messenger for EBR-induced CO2 assimilation and carbohydrate metabolism in cucumber plants. Our study confirms that H2O2 mediates the regulation of photosynthesis by BRs and suggests that EBR and H2O2 regulate Calvin cycle and sugar metabolism via redox signaling and thus increase the photosynthetic potential and yield of crops. PMID:23024048

  15. Can Melatonin Act as an Antioxidant in Hydrogen Peroxide-Induced Oxidative Stress Model in Human Peripheral Blood Mononuclear Cells?

    PubMed Central

    Emamgholipour, Solaleh; Hossein-Nezhad, Arash; Ansari, Mohammad

    2016-01-01

    Purpose. We aimed to investigate the possible effects of melatonin on gene expressions and activities of MnSOD and catalase under conditions of oxidative stress induced by hydrogen peroxide (H2O2) in peripheral blood mononuclear cells (PBMCs). Materials and Methods. PBMCs were isolated from healthy subjects and treated as follows: (1) control (only with 0.1% DMSO for 12 h); (2) melatonin (1 mM) for 12 h; (3) H2O2 (250 μM) for 2 h; (4) H2O2 (250 μM) for 2 h following 10 h pretreatment with melatonin (1 mM). The gene expression was evaluated by real-time PCR. MnSOD and catalase activities in PBMCs were determined by colorimetric assays. Results. Pretreatment of PBMCs with melatonin significantly augmented expression and activity of MnSOD which were diminished by H2O2. Melatonin treatment of PBMCs caused a significant upregulation of catalase by almost 2-fold in comparison with untreated cells. However, activity and expression of catalase increased by 1.5-fold in PBMCs under H2O2-induced oxidative stress compared with untreated cell. Moreover, pretreatment of PBMCs with melatonin resulted in a significant 1.8-fold increase in catalase expression compared to PBMCs treated only with H2O2. Conclusion. It seems that melatonin could prevent from undesirable impacts of H2O2-induced oxidative stress on MnSOD downregulation. Moreover, melatonin could promote inductive effect of H2O2 on catalase mRNA expression. PMID:26881079

  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. 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.

  18. Oxygen and hydrogen peroxide enhance light-induced carotenoid synthesis in Neurospora crassa.

    PubMed

    Iigusa, Hideo; Yoshida, Yusuke; Hasunuma, Kohji

    2005-07-18

    Previously, we found that intracellular reactive oxygen species (ROS) affect photomorphogenesis in Neurospora crassa. In this study, we investigated the physiological roles of ROS in the response to light and found that the exposure of mycelia to air was important for the light-induced carotenogenesis. Mycelia treated with a high concentration of O(2) gas and H(2)O(2) to release ROS showed an enhancement of light-induced carotenoid accumulation and the expression of gene related to light-inducible carotenogenesis. These results suggested that stimuli caused by the exposure of the mycelia to air containing O(2) gas triggered the light-induced carotenoid synthesis.

  19. 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

  20. Lysophosphatidic acid rescues bone mesenchymal stem cells from hydrogen peroxide-induced apoptosis.

    PubMed

    Wang, Xian-Yun; Fan, Xue-Song; Cai, Lin; Liu, Si; Cong, Xiang-Feng; Chen, Xi

    2015-03-01

    The increase of reactive oxygen species in infracted heart significantly reduces the survival of donor mesenchymal stem cells, thereby attenuating the therapeutic efficacy for myocardial infarction. In our previous study, we demonstrated that lysophosphatidic acid (LPA) protects bone marrow-derived mesenchymal stem cells (BMSCs) against hypoxia and serum deprivation-induced apoptosis. However, whether LPA protects BMSCs from H2O2-induced apoptosis was not examined. In this study, we report that H2O2 induces rat BMSC apoptosis whereas LPA pre-treatment effectively protects BMSCs from H2O2-induced apoptosis. LPA protection of BMSC from the induced apoptosis is mediated mostly through LPA3 receptor. Furthermore, we found that membrane G protein Gi2 and Gi3 are involved in LPA-elicited anti-apoptotic effects through activation of ERK1/2- and PI3 K-pathways. Additionally, H2O2 increases levels of type II of light chain 3B (LC3B II), an autophagy marker, and H2O2-induced autophagy thus protected BMSCs from apoptosis. LPA further increases the expression of LC3B II in the presence of H2O2. In contrast, autophagy flux inhibitor bafilomycin A1 has no effect on LPA's protection of BMSC from H2O2-induced apoptosis. Taken together, our data suggest that LPA rescues H2O2-induced apoptosis mainly by interacting with Gi-coupled LPA3, resulting activation of the ERK1/2- and PI3 K/AKT-pathways and inhibition caspase-3 cleavage, and LPA protection of BMSCs against the apoptosis is independent of it induced autophagy.

  1. Endogenous hydrogen peroxide in the hypothalamic paraventricular nucleus regulates neurohormonal excitation in high salt-induced hypertension.

    PubMed

    Zhang, Meng; Qin, Da-Nian; Suo, Yu-Ping; Su, Qing; Li, Hong-Bao; Miao, Yu-Wang; Guo, Jing; Feng, Zhi-Peng; Qi, Jie; Gao, Hong-Li; Mu, Jian-Jun; Zhu, Guo-Qing; Kang, Yu-Ming

    2015-06-15

    Reactive oxygen species (ROS) in the brain plays an important role in the progression of hypertension and hydrogen peroxide (H2O2) is a major component of ROS. The aim of this study is to explore whether endogenous H2O2 changed by polyethylene glycol-catalase (PEG-CAT) and aminotriazole (ATZ) in the hypothalamic paraventricular nucleus (PVN) regulates neurotransmitters, renin-angiotensin system (RAS), and cytokines, and whether subsequently affects the renal sympathetic nerve activity (RSNA) and mean arterial pressure (MAP) in high salt-induced hypertension. Male Sprague-Dawley rats received a high-salt diet (HS, 8% NaCl) or a normal-salt diet (NS, 0.3% NaCl) for 10 weeks. Then rats were treated with bilateral PVN microinjection of PEG-CAT (0.2 i.u./50nl), an analog of endogenous catalase, the catalase inhibitor ATZ (10nmol/50nl) or vehicle. High salt-fed rats had significantly increased MAP, RSNA, plasma norepinephrine (NE) and pro-inflammatory cytokines (PICs). In addition, rats with high-salt diet had higher levels of NOX-2, NOX-4 (subunits of NAD(P)H oxidase), angiotensin-converting enzyme (ACE), interleukin-1beta (IL-1β), glutamate and NE, and lower levels of gamma-aminobutyric acid (GABA) and interleukin-10 (IL-10) in the PVN than normal diet rats. Bilateral PVN microinjection of PEG-CAT attenuated the levels of RAS and restored the balance of neurotransmitters and cytokines, while microinjection of ATZ into the PVN augmented those changes occurring in hypertensive rats. Our findings demonstrate that ROS component H2O2 in the PVN regulating MAP and RSNA are partly due to modulate neurotransmitters, renin-angiotensin system, and cytokines within the PVN in salt-induced hypertension.

  2. 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.

  3. Inhibition of Hydrogen Peroxide-Induced Human Umbilical Vein Endothelial Cells Aging by Allicin Depends on Sirtuin1 Activation

    PubMed Central

    Lin, Xiao-Long; Liu, Yuanbo; Liu, Mihua; Hu, Huijun; Pan, Yongquan; Fan, Xiao-Juan; Hu, Xue-Mei; Zou, Wei-Wen

    2017-01-01

    Background The abnormal activity of Sirtuin 1 (Sirt1) is closely related to the aging of vascular endothelial cells. As a bioactive molecule, allicin has antioxidant, anti-inflammatory, and lipid-regulating mechanisms. However, few reports about the relationship of allicin and Sirt1 have been published. In this study, we aimed to elucidate the effect of allicin on Human Umbilical Vein Endothelial Cells (HUVECs) aging induced by hydrogen peroxide (H2O2) and the role of Sirt1 in this phenomenon. Material/Methods HUVEC were exposed to H2O2 to establish the aging model. The expression of protein and RNA were detected by Western blot and Reverse transcription-quantitative polymerase chain reaction. The 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to assess cell viability. Sirt1 enzyme activity assay was used to analyze enzymatic activity. Reactive oxygen species was detected by dichlorofluorescein diacetate (DCFH-DA). Cell aging was detected by Senescence β-Galactosidase (SA-β-gal) staining. Results Results of this study revealed that pretreating HUVECs with 5 ng/mL allicin before exposure to H2O2 resulted in increased cell viability and reduced reactive oxygen species generation. Western blot and quantitative real-time polymerase chain reaction (qRT-PCR) analysis showed that H2O2 attenuated the phosphorylation and activation of Sirt1 and increased the expression of plasminogen activator inhibitor-1(PAI-1) protein. Moreover, H2O2 also promoted HUVEC aging. These effects were significantly alleviated by 5 ng/mL allicin co-treatment. Furthermore, the anti-aging effects of allicin were abolished by the Sirt1 inhibitor nicotinamide (NAM). Conclusions Overall, the results demonstrated that allicin protects HUVECs from H2O2-induced oxidative stress and aging via the activation of Sirt1. PMID:28139552

  4. Nitric oxide and protein S-nitrosylation are integral to hydrogen peroxide-induced leaf cell death in rice.

    PubMed

    Lin, Aihong; Wang, Yiqin; Tang, Jiuyou; Xue, Peng; Li, Chunlai; Liu, Linchuan; Hu, Bin; Yang, Fuquan; Loake, Gary J; Chu, Chengcai

    2012-01-01

    Nitric oxide (NO) is a key redox-active, small molecule involved in various aspects of plant growth and development. Here, we report the identification of an NO accumulation mutant, nitric oxide excess1 (noe1), in rice (Oryza sativa), the isolation of the corresponding gene, and the analysis of its role in NO-mediated leaf cell death. Map-based cloning revealed that NOE1 encoded a rice catalase, OsCATC. Furthermore, noe1 resulted in an increase of hydrogen peroxide (H(2)O(2)) in the leaves, which consequently promoted NO production via the activation of nitrate reductase. The removal of excess NO reduced cell death in both leaves and suspension cultures derived from noe1 plants, implicating NO as an important endogenous mediator of H(2)O(2)-induced leaf cell death. Reduction of intracellular S-nitrosothiol (SNO) levels, generated by overexpression of rice S-nitrosoglutathione reductase gene (GSNOR1), which regulates global levels of protein S-nitrosylation, alleviated leaf cell death in noe1 plants. Thus, S-nitrosylation was also involved in light-dependent leaf cell death in noe1. Utilizing the biotin-switch assay, nanoliquid chromatography, and tandem mass spectrometry, S-nitrosylated proteins were identified in both wild-type and noe1 plants. NO targets identified only in noe1 plants included glyceraldehyde 3-phosphate dehydrogenase and thioredoxin, which have been reported to be involved in S-nitrosylation-regulated cell death in animals. Collectively, our data suggest that both NO and SNOs are important mediators in the process of H(2)O(2)-induced leaf cell death in rice.

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

    PubMed

    Zhou, Aifen; He, Zhili; Redding-Johanson, Alyssa M; Mukhopadhyay, Aindrila; Hemme, Christopher L; Joachimiak, Marcin P; Luo, Feng; Deng, Ye; Bender, Kelly S; He, Qiang; Keasling, Jay D; Stahl, David A; Fields, Matthew W; Hazen, Terry C; Arkin, Adam P; Wall, Judy D; Zhou, Jizhong

    2010-10-01

    To understand how sulphate-reducing bacteria respond to oxidative stresses, the responses of Desulfovibrio vulgaris Hildenborough to H(2)O(2)-induced stresses were investigated with transcriptomic, proteomic and genetic approaches. H(2)O(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(2)O(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(2)O(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(2)O(2)-induced stresses. In addition, a conceptual cellular model of D. vulgaris responses to H(2)O(2) stress was constructed to illustrate that this bacterium may employ a complicated molecular mechanism to defend against the H(2)O(2)-induced stresses.

  6. 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

  7. Dimethyl sulfoxide attenuates hydrogen peroxide-induced injury in cardiomyocytes via heme oxygenase-1.

    PubMed

    Man, Wang; Ming, Ding; Fang, Du; Chao, Liang; Jing, Cang

    2014-06-01

    The antioxidant property of dimethyl sulfoxide (DMSO) was formerly attributed to its direct effects. Our former study showed that DMSO is able to induce heme oxygenase-1 (HO-1) expression in endothelial cells, which is a potent antioxidant enzyme. In this study, we hypothesized that the antioxidant effects of DMSO in cardiomyocytes are mediated or partially mediated by increased HO-1 expression. Therefore, we investigated whether DMSO exerts protective effects against H2 O2 -induced oxidative damage in cardiomyocytes, and whether HO-1 is involved in DMSO-imparted protective effects, and we also explore the underlying mechanism of DMSO-induced HO-1 expression. Our study demonstrated that DMSO pretreatment showed a cytoprotective effect against H2 O2 -induced oxidative damage (impaired cell viability, increased apopototic cells rate and caspase-3 level, and increased release of LDH and CK) and this process is partially mediated by HO-1 upregulation. Furthermore, our data showed that the activation of p38 MAPK and Nrf2 translocation are involved in the HO-1 upregulation induced by DMSO. This study reports for the first time that the cytoprotective effect of DMSO in cardiomyocytes is partially mediated by HO-1, which may further explain the mechanisms by which DMSO exerts cardioprotection on H2 O2 injury. J. Cell. Biochem. 115: 1159-1165, 2014. © 2013 Wiley Periodicals, Inc.

  8. 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.

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

    PubMed

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

    2016-10-14

    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.

  10. 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 ...

  11. 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

  12. Edgeless Ag-Pt Bimetallic Nanocages: In Situ Monitor Plasmon-Induced Suppression of Hydrogen Peroxide Formation.

    PubMed

    Lin, Sheng-Chih; Hsu, Chia-Shuo; Chiu, Shih-Yun; Liao, Tzu-Yu; Chen, Hao Ming

    2017-02-15

    Improvements in the performance of electrocatalysts, along with continuing advances in selective pathway for target reaction, have great potential to offer opportunities in designing competitive reactions especially for using a photophysical process owing to its tunable properties. Herein, we demonstrated a first empirical evidence of suppressing the formation of undesired peroxide intermediate through plasmonic effects, in which plasmonic Ag-Pt bimetallic nanocages were synthesized with an edgeless feature, and a custom-made RDE/RRDE working station was designed to provide unique means by which to in situ realize the plasmon-induced effects toward the target reaction. The edgeless Ag-Pt bimetallic nanocages with hollow interior performed newly plasmon-induced effects, which was characteristic of photodependent nature to suppress the formation of undesired peroxide intermediate. We concluded that the plasmon-induced hot electron transfer governed the suppression of peroxide formation instead of plasmon-induced heating that would cause a negative effect (i.e., increase of peroxide yield), in which the hot electron transfer of Ag nanostructure offered a sufficient energy to populate the antibonding orbital of O2 as illustrated by in situ X-ray absorption approach. This rapid light-dependent nature corresponding to localized surface plasmon resonance in present nanocages can potentially offer synergetic strategies toward altering the chemical reactions or reaction pathways in various fields.

  13. The Antiapoptosis Effect of Glycyrrhizate on HepG2 Cells Induced by Hydrogen Peroxide

    PubMed Central

    Su, Miao; Yu, Tengfei; Zhang, Hong; Wu, Yan; Wang, Xiaoqin

    2016-01-01

    This study demonstrated that glycyrrhizate (GAS) could protect HEPG2 cells against damage and apoptosis induced by H2O2 (1600 μM, 4 h). Cell viability assay revealed that GAS was noncytotoxity at concentration 125 µg/mL, and GAS (5 μg/mL, 25 μg/mL, and 125 μg/mL) protected HepG2 cells against H2O2-induced cytotoxicity. H2O2 induced the HepG2 cells apoptosis, obvious morphologic changes were observed after Hochest 33258 staining, and more apoptotic cells were counted in flow cytometry assay compared to that of the natural group. Pretreatment GAS (5 μg/mL, 25 μg/mL, and 125 μg/mL) prior to H2O2 reverses the morphologic changes and reduced the apoptotic cells in HepG2 cells. GAS reduced the release of MDA, increased the activities of superoxide dismutase, and diminished the release of ALT and AST during oxidative stress in HepG2 cells. After Elisa kit detecting, GAS inhibited the caspase activity induced by H2O2, GAS decreased the level of caspase-3 and caspase-9 from mitochondria in dose-dependent manner. Western blot results showed that pretreatment GAS upregulated the expression of Bcl-2 and decreased the expression of Bax. These results reveal that GAS has the cytoprotection in HepG2 cells during ROS exposure by inhibiting the caspase activity in the mitochondria and influencing apoptogenic factors of the expression of Bax and Bcl-2. PMID:27891207

  14. 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.

  15. 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.

  16. Hydrogen peroxide-induced chlorophyll a bleaching in the cytochrome b6f complex: a simple and effective assay for stability of the complex in detergent solutions.

    PubMed

    Chen, Xiao-Bo; Zhao, Xiao-Hui; Zhu, Yi; Gong, Yan-Dao; Li, Liang-Bi; Zhang, Jian-Ping; Kuang, Ting-Yun

    2006-12-01

    The instability of cytochrome b ( 6 ) f complex in detergent solutions is a well-known problem that has been studied extensively, but without finding a satisfactory solution. One of the important reasons can be short of the useful method to verify whether the complex suspended in different detergent is in an intact state or not. In this article, a simple and effective assay for stability of the complex was proposed based on the investigation on the different effects of the two detergents, n-octyl-beta-D: -glucopyranoside (OG) and dodecyl-beta-D: -maltoside (DDM), on the properties of the complex. DDM stabilizes the complex preparation more effectively whereas OG denatures the interactions of the heme groups and pigment molecules with the protein environment, leading to the bleaching of chlorophyll a induced by addition of hydrogen peroxide. The assay of the use of hydrogen peroxide to characterize the complex by studying the bleaching of chlorophyll induced by hydrogen peroxide and the peroxidase activity of the complex was discussed. This simple method will probably be useful to study the stability of the complex.

  17. Mussel oligopeptides protect human fibroblasts from hydrogen peroxide (H2O2)-induced premature senescence.

    PubMed

    Zhou, Yue; Dong, Ying; Xu, Qing-Gang; Zhu, Shu-Yun; Tian, Shi-Lei; Huo, Jing-jing; Hao, Ting-Ting; Zhu, Bei-Wei

    2014-01-01

    Mussel bioactive peptides have been viewed as mediators to maximize the high quality of life. In this study, the anti-aging activities of mussel oligopeptides were evaluated using H2O2-induced prematurely senescent MRC-5 fibroblasts. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry displayed that exposure to H2O2 led to the loss of cell viability and cell cycle arrest. In addition, H2O2 caused the elevation of senescence-associated-β-galactosidase (SA-β-gal) activity and formation of senescence-associated heterochromatin foci (SAHF). It was found that pretreatment with mussel oligopeptides could significantly attenuate these properties associated with cellular senescence. Mussel oligopeptides also led to the increase of glutathione (GSH) level and mitochondrial transmembrane potential (Δψm) recovery. In addition, mussel oligopeptides resulted in an improvement in transcriptional activity of peroxiredoxin 1 (Prx1), nicotinamide phosphoribosyltransferase (NAMPT) and sirtuin 1 (SIRT1). This study revealed that mussel oligopeptides could protect against cellular senescence induced by H2O2, and the effects were closely associated with redox cycle modulating and potentiating the SIRT1 pathway. These findings provide new insights into the beneficial role of mussel bioactive peptides on retarding senescence process.

  18. 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.

  19. Hydrogen peroxide induces La cytoplasmic shuttling and increases hepatitis C virus internal ribosome entry site-dependent translation.

    PubMed

    Chan, Shiu-Wan

    2016-09-01

    We have previously shown that physio/pathological levels of hydrogen peroxide (H2O2) stimulate translation from the hepatitis C virus (HCV) internal ribosome entry site (IRES) element in tissue-cultured cells. Here, using in vitro translation, we further show that H2O2 upregulates HCV IRES-dependent mRNA translation and correlates with an increase in intracellular oxidant level. Using Western blotting, immunocytochemistry, microscopy and affinity pulldown, we show that H2O2 stimulates HCV IRES-dependent translation and correlates with nuclear-cytoplasmic shuttling of the La autoantigen, resulting in enhanced binding of cytoplasmic La to HCV IRES RNA. The role of the La protein in H2O2-stimulated IRES-dependent translation is further confirmed by the ability of an anti-La antibody to suppress H2O2-activated IRES-dependent translation in vitro. This is further supported by the ability of an ectopically expressed dominant, negative La mutant protein to suppress H2O2-inducible IRES-mediated translation in Huh7 cells, transiently transfected with a bicistronic reporter and in a sub-genomic replicon cell line resembling a persistent infection. On the other hand, translation from the encephalomyocarditis virus IRES is diminished in the presence of H2O2, suggesting that H2O2 translational responsiveness is a specific property of the HCV IRES and is not a general phenomenon for all viral IRESs. Altogether, these results suggest that HCV adapts to physio/pathological oxidative stress in the host cell by mediating La cytoplasmic shuttling to enhance its IRES-dependent translation.

  20. 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.

  1. Peroxide-induced cell death and lipid peroxidation in C6 glioma cells.

    PubMed

    Linden, Arne; Gülden, Michael; Martin, Hans-Jörg; Maser, Edmund; Seibert, Hasso

    2008-08-01

    Peroxides are often used as models to induce oxidative damage in cells in vitro. The aim of the present study was to elucidate the role of lipid peroxidation in peroxide-induced cell death. To this end (i) the ability to induce lipid peroxidation in C6 rat astroglioma cells of hydrogen peroxide (H2O2), cumene hydroperoxide (CHP) and t-butyl hydroperoxide (t-BuOOH) (ii) the relation between peroxide-induced lipid peroxidation and cell death in terms of time and concentration dependency and (iii) the capability of the lipid peroxidation chain breaking alpha-tocopherol to prevent peroxide-induced lipid peroxidation and/or cell death were investigated. Lipid peroxidation was characterised by measuring thiobarbituric acid reactive substances (TBARS) and, by HPLC, malondialdehyde (MDA), 4-hydroxynonenal (4-HNE) and hexanal. Within 2 h CHP, t-BuOOH and H2O2 induced cell death with EC50 values of 59+/-9 microM, 290+/-30 microM and 12+/-1.1 mM, respectively. CHP and t-BuOOH, but not H2O2 induced lipid peroxidation in C6 cells with EC50 values of 15+/-14 microM and 130+/-33 microM, respectively. The TBARS measured almost exclusively consisted of MDA. 4-HNE was mostly not detectable. The concentration of hexanal slightly increased with increasing concentrations of organic peroxides. Regarding time and concentration dependency lipid peroxidation preceded cell death. Pretreatment with alpha-tocopherol (10 microM, 24 h) prevented both, peroxide-induced lipid peroxidation and cell death. The results strongly indicate a major role of lipid peroxidation in the killing of C6 cells by organic peroxides but also that lipid peroxidation is not involved in H2O2 induced cell death.

  2. 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.

  3. Differential role of ethylene and hydrogen peroxide in dark-induced stomatal closure.

    PubMed

    Kar, R K; Parvin, N; Laha, D

    2013-12-15

    Regulation of stomatal aperture is crucial in terrestrial plants for controlling water loss and gaseous exchange with environment. While much is known of signaling for stomatal opening induced by blue light and the role of hormones, little is known about the regulation of stomatal closing in darkness. The present study was aimed to verify their role in stomatal regulation in darkness. Epidermal peelings from the leaves of Commelina benghalensis were incubated in a defined medium in darkness for 1 h followed by a 1 h incubation in different test solutions [H2O2, propyl gallate, ethrel (ethylene), AgNO3, sodium orthovanadate, tetraethyl ammonium chloride, CaCl2, LaCl3, separately and in combination] before stomatal apertures were measured under the microscope. In the dark stomata remained closed under treatments with ethylene and propyl gallate but opened widely in the presence of H2O2 and AgNO3. The opening effect was largely unaffected by supplementing the treatment with Na-vanadate (PM H+ ATPase inhibitor) and tetraethyl ammonium chloride (K(+)-channel inhibitor) except that opening was significantly inhibited by the latter in presence of H2O2. On the other hand, H2O2 could not override the closing effect of ethylene at any concentrations while a marginal opening of stomata was found when Ag NO3 treatment was given together with propyl gallate. CaCl2 treatment opened stomata in the darkness while LaCl3 maintained stomata closed. A combination of LaCl3 and propyl gallate strongly promoted stomatal opening. A probable action of ethylene in closing stomata of Commelina benghalensis in dark has been proposed.

  4. Hydrogen peroxide induced by the fungicide prothioconazole triggers deoxynivalenol (DON) production by Fusarium graminearum

    PubMed Central

    2010-01-01

    Background Fusarium head blight is a very important disease of small grain cereals with F. graminearum as one of the most important causal agents. It not only causes reduction in yield and quality but from a human and animal healthcare point of view, it produces mycotoxins such as deoxynivalenol (DON) which can accumulate to toxic levels. Little is known about external triggers influencing DON production. Results In the present work, a combined in vivo/in vitro approach was used to test the effect of sub lethal fungicide treatments on DON production. Using a dilution series of prothioconazole, azoxystrobin and prothioconazole + fluoxastrobin, we demonstrated that sub lethal doses of prothioconazole coincide with an increase in DON production 48 h after fungicide treatment. In an artificial infection trial using wheat plants, the in vitro results of increased DON levels upon sub lethal prothioconazole application were confirmed illustrating the significance of these results from a practical point of view. In addition, further in vitro experiments revealed a timely hyperinduction of H2O2 production as fast as 4 h after amending cultures with prothioconazole. When applying H2O2 directly to germinating conidia, a similar induction of DON-production by F. graminearum was observed. The effect of sub lethal prothioconazole concentrations on DON production completely disappeared when applying catalase together with the fungicide. Conclusions These cumulative results suggest that H2O2 induced by sub lethal doses of the triazole fungicide prothioconazole acts as a trigger of DON biosynthesis. In a broader framework, this work clearly shows that DON production by the plant pathogen F. graminearum is the result of the interaction of fungal genomics and external environmental triggers. PMID:20398299

  5. A copper-hydrogen peroxide redox system induces dityrosine cross-links and chemokine oligomerisation.

    PubMed

    MacGregor, Helen J; Kato, Yoji; Marshall, Lindsay J; Nevell, Thomas G; Shute, Janis K

    2011-12-01

    The activity of the chemoattractant cytokines, the chemokines, in vivo is enhanced by oligomerisation and aggregation on glycosaminoglycan (GAG), particularly heparan sulphate, side chains of proteoglycans. The chemokine RANTES (CCL5) is a T-lymphocyte and monocyte chemoattractant, which has a minimum tetrameric structure for in vivo activity and a propensity to form higher order oligomers. RANTES is unusual among the chemokines in having five tyrosine residues, an amino acid susceptible to oxidative cross-linking. Using fluorescence emission spectroscopy, Western blot analysis and LCMS-MS, we show that a copper/H2O2 redox system induces the formation of covalent dityrosine cross-links and RANTES oligomerisation with the formation of tetramers, as well as higher order oligomers. Amongst the transition metals tested, namely copper, nickel, mercury, iron and zinc, copper appeared unique in this respect. At high (400 μM) concentrations of H2O2, RANTES monomers, dimers and oligomers are destroyed, but heparan sulphate protects the chemokine from oxidative damage, promoting dityrosine cross-links and multimer formation under oxidative conditions. Low levels of dityrosine cross-links were detected in copper/H2O2-treated IL-8 (CXCL8), which has one tyrosine residue, and none were detected in ENA-78 (CXCL5), which has none. Redox-treated RANTES was fully functional in Boyden chamber assays of T-cell migration and receptor usage on activated T-cells following RANTES oligomerisation was not altered. Our results point to a protective, anti-oxidant, role for heparan sulphate and a previously unrecognised role for copper in chemokine oligomerisation that may offer an explanation for the known anti-inflammatory effect of copper-chelators such as penicillamine and tobramycin.

  6. Reaction of chromium(VI) with glutathione or with hydrogen peroxide: Identification of reactive intermediates and their role in chromium(VI)-induced DNA damage

    SciTech Connect

    Aiyar, J.; Berkovits, H.J.; Wetterhahn, K.E. ); Floyd, R.A. )

    1991-05-01

    The types of reactive intermediates generated upon reduction of chromium (VI) by glutathione or hydrogen peroxide and the resulting DNA damage have been determined. In vitro, reaction of chromium (VI) with glutathione led to formation of two chromium (V) complexes and the glutathione thiyl radical. When chromium (VI) was reacted with DNA in the presence of glutathione, chromium-DNA adducts were obtained, with no DNA strand breakage. The level of chromium-DNA adduct formation correlated with chromium (V) formation. Reaction of chromium (VI) with hydrogen peroxide led to formation of hydroxyl radical. No chromium (V) was detectable at 24 C (297 K); however, low levels of the tetraperoxochromium (V) complex were detected at 77 K. Reaction of chromium (VI) with DNA in the presence of hydrogen peroxide produced significant DNA strand breakage and the 8-hydroxydeoxyguanosine adduct, whose formation correlated with hydroxyl radical production. No significant chromium-DNA adduct formation was detected. Thus, the nature of chromium (VI)-induced DNA damage appears to be dependent on the reactive intermediates, i.e., chromium (V) or hydroxyl radical, produced during the reduction of chromium (VI).

  7. Hydrogen peroxide induces G:C to T:A and G:C to C:G transversions in the supF gene of Escherichia coli.

    PubMed

    Akasaka, S; Yamamoto, K

    1994-06-03

    A vector plasmid, pZ189, carrying an Escherichia coli supF gene as a target for mutations, was treated with a combination of hydrogen peroxide and Fe3+/EDTA complex and propagated in E. coli host cells that had been induced for SOS functions by ultraviolet irradiation. The mutations frequency increased by up to 30-fold over spontaneous background levels with increasing concentrations of hydrogen peroxide. The increase in mutation frequency correlated with an increase in the formation of 8-hydroxydeoxyguanosine in the pZ189 DNA. Sequence analysis of 82 independent supF mutant plasmids revealed that 70 mutants contained base substitutions, with 63 of the 70 involving a G:C base pair, and with G:C-->C:G (28 cases) and G:C-->T:A (26 cases) transversions predominating. Investigation of the influence of the local DNA sequence on the transversions revealed that the guanine at the center of the triplet 5'-PuGA-3' was five times more likely to mutate after treatment with hydrogen peroxide than that at the center of 5'PyGN3'. G:C-->T:A transversions presumably resulted from mispairing of an altered G (probably 8-hydroxydeoxyguanosine) with deoxyadenosine. The origin of the G:C-->C:G transversions may be an as yet unidentified lesion generated by hydrogen peroxide. Mutagenic hotspots for base substitutions were found at positions 133, 160 and 168. Mutation spectra and the positions of mutagenic hotspots, when compared with a previously determined spontaneous mutagenesis spectrum, also provide information on the mechanism of spontaneous mutagenesis.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Paraquat toxicity and effect of hydrogen peroxide on thermophilic bacteria.

    PubMed

    Allgood, G S; Perry, J J

    1985-01-01

    Paraquat (PQ++) increased cyanide-resistant univalent respiration in cell suspensions of five strains of obligately thermophilic bacteria. PQ++ was reduced by an NADH: or NADPH:paraquat diaphorase and selectivity for NADH, NADPH, or both electron donors varied among the thermophiles. Superoxide anion production that was dependent on the presence of PQ++ was shown by following the superoxide dismutase-inhibitable reduction of cytochrome c. In addition, the PQ++-dependent formation of hydrogen peroxide from superoxide anion was evident in two of the thermophilic strains. Catalase synthesis was induced by adding hydrogen peroxide to the growth medium of the thermophiles. The induction of catalase to eliminate hydrogen peroxide appears to be an important response of these thermophilic bacteria to oxygen toxicity.

  13. Oregano Essential Oil Induces SOD1 and GSH Expression through Nrf2 Activation and Alleviates Hydrogen Peroxide-Induced Oxidative Damage in IPEC-J2 Cells

    PubMed Central

    Zou, Yi; Wang, Jun; Peng, Jian

    2016-01-01

    Oregano essential oil (OEO) has long been used to improve the health of animals, particularly their intestinal health. The health benefits of OEO are generally attributed to antioxidative actions, but the mechanisms remain unclear. Here, we investigate the antioxidative effects of OEO and their underlying molecular mechanisms in porcine small intestinal epithelial (IPEC-J2) cells. We found that OEO treatment prior to hydrogen peroxide (H2O2) exposure increased cell viability and prevented lactate dehydrogenase (LDH) release into the medium. H2O2-induced reactive oxygen species (ROS) and malondialdehyde (MDA) were remarkably suppressed by OEO. OEO dose-dependently increased mRNA and protein levels of the nuclear factor-erythroid 2-related factor-2 (Nrf2) target genes Cu/Zn-superoxide dismutase (SOD1) and g-glutamylcysteine ligase (GCLC, GLCM), as well as intracellular concentrations of SOD1 and glutathione. OEO also increased intranuclear expression of Nrf2 and the activity of an antioxidant response element reporter plasmid in IPEC-J2 cells. The OEO-induced expression of Nrf2-regulated genes and increased SOD1 and glutathione concentrations in IPEC-J2 cells were reduced by Nrf2 small interfering (si) RNAs, counteracting the protective effects of OEO against oxidative stress in IPEC-J2 cells. Our results suggest that OEO protects against H2O2-induced IPEC-J2 cell damage by inducing Nrf2 and related antioxidant enzymes. PMID:28105249

  14. Oregano Essential Oil Induces SOD1 and GSH Expression through Nrf2 Activation and Alleviates Hydrogen Peroxide-Induced Oxidative Damage in IPEC-J2 Cells.

    PubMed

    Zou, Yi; Wang, Jun; Peng, Jian; Wei, Hongkui

    2016-01-01

    Oregano essential oil (OEO) has long been used to improve the health of animals, particularly their intestinal health. The health benefits of OEO are generally attributed to antioxidative actions, but the mechanisms remain unclear. Here, we investigate the antioxidative effects of OEO and their underlying molecular mechanisms in porcine small intestinal epithelial (IPEC-J2) cells. We found that OEO treatment prior to hydrogen peroxide (H2O2) exposure increased cell viability and prevented lactate dehydrogenase (LDH) release into the medium. H2O2-induced reactive oxygen species (ROS) and malondialdehyde (MDA) were remarkably suppressed by OEO. OEO dose-dependently increased mRNA and protein levels of the nuclear factor-erythroid 2-related factor-2 (Nrf2) target genes Cu/Zn-superoxide dismutase (SOD1) and g-glutamylcysteine ligase (GCLC, GLCM), as well as intracellular concentrations of SOD1 and glutathione. OEO also increased intranuclear expression of Nrf2 and the activity of an antioxidant response element reporter plasmid in IPEC-J2 cells. The OEO-induced expression of Nrf2-regulated genes and increased SOD1 and glutathione concentrations in IPEC-J2 cells were reduced by Nrf2 small interfering (si) RNAs, counteracting the protective effects of OEO against oxidative stress in IPEC-J2 cells. Our results suggest that OEO protects against H2O2-induced IPEC-J2 cell damage by inducing Nrf2 and related antioxidant enzymes.

  15. Hydrogen sulfide prevents hydrogen peroxide-induced activation of epithelial sodium channel through a PTEN/PI(3,4,5)P3 dependent pathway.

    PubMed

    Zhang, Jianing; Chen, Shuo; Liu, Huibin; Zhang, Bingkun; Zhao, Ying; Ma, Ke; Zhao, Dan; Wang, Qiushi; Ma, Heping; Zhang, Zhiren

    2013-01-01

    Sodium reabsorption through the epithelial sodium channel (ENaC) at the distal segment of the kidney plays an important role in salt-sensitive hypertension. We reported previously that hydrogen peroxide (H2O2) stimulates ENaC in A6 distal nephron cells via elevation of phosphatidylinositol 3,4,5-trisphosphate (PI(3,4,5)P3) in the apical membrane. Here we report that H2S can antagonize H2O2-induced activation of ENaC in A6 cells. Our cell-attached patch-clamp data show that ENaC open probability (PO ) was significantly increased by exogenous H2O2, which is consistent with our previous finding. The aberrant activation of ENaC induced by exogenous H2O2 was completely abolished by H2S (0.1 mM NaHS). Pre-treatment of A6 cells with H2S slightly decreased ENaC P(O); however, in these cells H2O2 failed to elevate ENaC PO . Confocal microscopy data show that application of exogenous H2O2 to A6 cells significantly increased intracellular reactive oxygen species (ROS) level and induced accumulation of PI(3,4,5)P3 in the apical compartment of the cell membrane. These effects of exogenous H2O2 on intracellular ROS levels and on apical PI(3,4,5)P3 levels were almost completely abolished by treatment of A6 cells with H2S. In addition, H2S significantly inhibited H2O2-induced oxidative inactivation of the tumor suppressor phosphatase and tensin homolog (PTEN) which is a negative regulator of PI(3,4,5)P3. Moreover, BPV(pic), a specific inhibitor of PTEN, elevated PI(3,4,5)P3 and ENaC activity in a manner similar to that of H2O2 in A6 cells. Our data show, for the first time, that H2S prevents H2O2-induced activation of ENaC through a PTEN-PI(3,4,5)P3 dependent pathway.

  16. Hydrogen Sulfide Prevents Hydrogen Peroxide-Induced Activation of Epithelial Sodium Channel through a PTEN/PI(3,4,5)P3 Dependent Pathway

    PubMed Central

    Zhang, Jianing; Chen, Shuo; Liu, Huibin; Zhang, Bingkun; Zhao, Ying; Ma, Ke; Zhao, Dan; Wang, Qiushi; Ma, Heping; Zhang, Zhiren

    2013-01-01

    Sodium reabsorption through the epithelial sodium channel (ENaC) at the distal segment of the kidney plays an important role in salt-sensitive hypertension. We reported previously that hydrogen peroxide (H2O2) stimulates ENaC in A6 distal nephron cells via elevation of phosphatidylinositol 3,4,5-trisphosphate (PI(3,4,5)P3) in the apical membrane. Here we report that H2S can antagonize H2O2-induced activation of ENaC in A6 cells. Our cell-attached patch-clamp data show that ENaC open probability (PO) was significantly increased by exogenous H2O2, which is consistent with our previous finding. The aberrant activation of ENaC induced by exogenous H2O2 was completely abolished by H2S (0.1 mM NaHS). Pre-treatment of A6 cells with H2S slightly decreased ENaC PO; however, in these cells H2O2 failed to elevate ENaC PO. Confocal microscopy data show that application of exogenous H2O2 to A6 cells significantly increased intracellular reactive oxygen species (ROS) level and induced accumulation of PI(3,4,5)P3 in the apical compartment of the cell membrane. These effects of exogenous H2O2 on intracellular ROS levels and on apical PI(3,4,5)P3 levels were almost completely abolished by treatment of A6 cells with H2S. In addition, H2S significantly inhibited H2O2-induced oxidative inactivation of the tumor suppressor phosphatase and tensin homolog (PTEN) which is a negative regulator of PI(3,4,5)P3. Moreover, BPV(pic), a specific inhibitor of PTEN, elevated PI(3,4,5)P3 and ENaC activity in a manner similar to that of H2O2 in A6 cells. Our data show, for the first time, that H2S prevents H2O2-induced activation of ENaC through a PTEN-PI(3,4,5)P3 dependent pathway. PMID:23741314

  17. The L-histidine-mediated enhancement of hydrogen peroxide-induced DNA double strand breakage and cytotoxicity does not involve metabolic processes.

    PubMed

    Sestili, P; Cattabeni, F; Cantoni, O

    1995-11-27

    the topology of chromosomal domains where DSBs are generated. Overall, the results presented in this paper provide further experimental evidence supporting the notion that DNA DSBs are responsible for the L-histidine-mediated enhancement of hydrogen peroxide-induced cytotoxicity, and demonstrate that the mechanism whereby the amino acid enhances the ability of hydrogen peroxide to produce DNA double strand breakage and cell killing does not depend on cellular metabolism and/or energy-dependent reactions.

  18. Nucleotides protect rat brain astrocytes against hydrogen peroxide toxicity and induce antioxidant defense via P2Y receptors.

    PubMed

    Förster, Daniel; Reiser, Georg

    2016-03-01

    Consequences of neurodegenerative diseases or stroke also depend on astroglial survival during oxidative stress. P2Y receptors that are widely distributed in the central nervous system are suggested to be involved in cytoprotection. However, knowledge about the efficacy of protection by P2Y receptors and their involvement in antioxidant protective pathways is scarce. Here, we investigate the viability and reactive oxygen species (ROS) production after exposure of rat astrocytes to hydrogen peroxide. We determined the influence of treatment with the P2Y1 receptor-specific agonist 2-methyl-thio-ADP (2MeSADP) and the broad range P2Y receptor agonist adenosine 5'-(3-thiotriphosphate) (ATPγS). Preincubation (24-h before hydrogen peroxide application) and incubation with ATPγS and 2MeSADP protected astrocytes. The ROS production in hydrogen peroxide-treated astrocytes was reduced by pre- and co-incubation with ATPγS or 2MeSADP. Changes of levels of expression of antioxidant defense systems in astrocytes by treatment with P2Y receptor agonists were analyzed. Incubation with ATPγS and 2MeSADP increased mRNA levels of CAT encoding catalase and SOD2, encoding mitochondrial manganese dependent superoxide dismutase. ATPγS additionally increased mRNA levels of SOD3, encoding extracellular superoxide dismutase (ECSOD). Levels of total glutathione (GSH) increased in ATPγS/2MeSADP-treated astrocytes. mRNA levels of genes involved in GSH synthesis and in import of GSH precursors were analyzed after treatment with ATPγS and 2MeSADP. Both agonists significantly increased mRNA levels of a subunit of glutamate cysteine ligase, and a subunit of antiporter system xc(-). Changes in mRNA levels of antioxidant enzymes and genes of GSH metabolism depend on rise of intracellular Ca(2+) by P2Y receptor and basal activity of protein kinase A (PKA). SOD3 induction is suggested to depend on increased intracellular Ca(2+), increased cyclic AMP levels and PKA activity. Thus, we confirm a

  19. Activation of ERK1/2 by protein kinase C-alpha in response to hydrogen peroxide-induced cell death in human gingival fibroblasts.

    PubMed

    Gutiérrez-Venegas, Gloria; Arreguín-Cano, Juan Antonio; Arroyo-Cruz, Rita; Villeda-Navarro, Mónica; Méndez-Mejía, José Antonio

    2010-02-01

    Hydrogen peroxide (H(2)O(2)) increases protein tyrosine phosphorylation of numerous proteins in human gingival fibroblasts (HGFs). Two main proteins, with an apparent molecular weight of 44 and 42kDa, were phosphorylated after hydrogen peroxide stimulation of the human gingival fibroblasts. Further analysis identified these two proteins as ERK1/2. Maximum phosphorylation was detected at 10min post-H(2)O(2) treatment. Pretreatment with an MEK inhibitor, PD98059, inhibited H(2)O(2)-stimulated ERK1/2 phosphorylation in a dose-dependent manner. Treatment with H(2)O(2) also induced phosphorylation of protein kinase C-alpha (PKCalpha). Staurosporine, a PKC inhibitor, blocked ERK1/2 phosphorylation induced by H(2)O(2). In addition, H(2)O(2)-induced cell death was prevented by PD98059, SB203580, and calphostin C, which are MEK, p38 and PKC inhibitors, respectively. These results suggest that H(2)O(2) leads to the phosphorylation and activation of ERK1/2 in a PKC-dependent manner. These findings demonstrate that the MAPK signaling pathway plays an active role in mediating the H(2)O(2)-induced decrease in HGF cell viability and ATP depletion.

  20. Involvement of heat shock protein-70 in the mechanism of hydrogen peroxide-induced DNA damage: the role of lysosomes and iron.

    PubMed

    Doulias, Paschalis-Thomas; Kotoglou, Polychronis; Tenopoulou, Margarita; Keramisanou, Dimitra; Tzavaras, Theodore; Brunk, Ulf; Galaris, Dimitrios; Angelidis, Charalampos

    2007-02-15

    Heat shock protein-70 (Hsp70) is the main heat-inducible member of the 70-kDa family of chaperones that assist cells in maintaining proteins functional under stressful conditions. In the present investigation, the role of Hsp70 in the molecular mechanism of hydrogen peroxide-induced DNA damage to HeLa cells in culture was examined. Stably transfected HeLa cell lines, overexpressing or lacking Hsp70, were created by utilizing constitutive expression of plasmids containing the functional hsp70 gene or hsp70-siRNA, respectively. Compared to control cells, the Hsp70-overexpressing ones were significantly resistant to hydrogen peroxide-induced DNA damage, while Hsp70-depleted cells showed an enhanced sensitivity. In addition, the "intracellular calcein-chelatable iron pool" was determined in the presence or absence of Hsp70 and found to be related to the sensitivity of nuclear DNA to H(2)O(2). It seems likely that the main action of Hsp70, at least in this system, is exerted at the lysosomal level, by protecting the membranes of these organelles against oxidative stress-induced destabilization. Apart from shedding additional light on the mechanistic details behind the action of Hsp70 during oxidative stress, our results indicate that modulation of cellular Hsp70 may represent a way to make cancer cells more sensitive to normal host defense mechanisms or chemotherapeutic drug treatment.

  1. 21 CFR 178.1005 - Hydrogen peroxide solution.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... SANITIZERS Substances Utilized To Control the Growth of Microorganisms § 178.1005 Hydrogen peroxide solution... hydrogen peroxide can be determined in distilled water packaged under production conditions (assay to...

  2. 21 CFR 178.1005 - Hydrogen peroxide solution.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... SANITIZERS Substances Utilized To Control the Growth of Microorganisms § 178.1005 Hydrogen peroxide solution... hydrogen peroxide can be determined in distilled water packaged under production conditions (assay to...

  3. 21 CFR 178.1005 - Hydrogen peroxide solution.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... SANITIZERS Substances Utilized To Control the Growth of Microorganisms § 178.1005 Hydrogen peroxide solution... hydrogen peroxide can be determined in distilled water packaged under production conditions (assay to...

  4. 21 CFR 178.1005 - Hydrogen peroxide solution.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... SANITIZERS Substances Utilized To Control the Growth of Microorganisms § 178.1005 Hydrogen peroxide solution... hydrogen peroxide can be determined in distilled water packaged under production conditions (assay to...

  5. Systems and methods for generation of hydrogen peroxide vapor

    DOEpatents

    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.

  6. 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

    2016-06-08

    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.

  7. 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.

  8. Protective Effects of Bacopa Monnieri on Hydrogen Peroxide and Staurosporine: Induced Damage of Human Neuroblastoma SH-SY5Y Cells.

    PubMed

    Łojewski, Maciej; Pomierny, Bartosz; Muszyńska, Bożena; Krzyżanowska, Weronika; Budziszewska, Bogusława; Szewczyk, Agnieszka

    2016-02-01

    Many herbs, and recently their biomass from in vitro cultures, are essential for the treatment of diseases. The aim of this study was to determine the optimal growth of Bacopa monnieri (water hyssop) in an in vitro culture and to examine if extracts of the B. monnieri biomass from the in vitro culture would affect hydrogen peroxide- and staurosporine-induced injury of the human neuroblastoma SH-SY5Y cell line. It has been found that B. monnieri at concentrations of 25, 50, and 100 µg/mL inhibited both hydrogen peroxide-induced efflux of lactate dehydrogenase from damaged cells to culture medium and increased cell viability determined by an MTT assay. Moreover, B. monnieri at concentrations of 10, 25, and 50 µg/mL decreased staurosporine-induced activity of an executive apoptotic enzyme-caspase-3 and protected mitochondrial membrane potential. The obtained data indicate that the biomass from the in vitro culture of B. monnieri prevented SH-SY5Y cell damage related to oxidative stress and had the ability to inhibit the apoptotic process. Thus, this study supports the traditional use of B. monnieri as a neuroprotective therapy, and further in vivo studies on the effects of this preparation on morphology and function of nerve cells could lead to its wider application.

  9. 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.

  10. Impact of hydrogen peroxide as a soil amendment on nasturtiums

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hydrogen peroxide, H2O2, is a highly reactive oxidizing agent naturally occurring in plants and animals. Plants produce hydrogen peroxide to destroy either their infected plant cells or the pathogens within their cells. Hydrogen peroxide also acts as a stress signal to plants. It is approved for c...

  11. 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.

  12. 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.

  13. 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.

  14. How do porosity-inducing techniques affect antibiotic elution from bone cement? An in vitro comparison between hydrogen peroxide and a mechanical mixer

    PubMed Central

    Lovric, V.; Leung, A.; Walsh, W. R.

    2008-01-01

    Background Increasing the porosity of an antibiotic-loaded cement spacer increases the antibiotic elution, but the correlation between porosity and antibiotic elution is not well documented. The purposes of this study was to attempt new porosity-increasing methods and to investigate the correlation between antibiotic elution and both total and surface porosity. Materials and methods Five types of antibiotic-loaded bone cement (ALBC) using 2 g cefazolin and 40 g cement were prepared. Other than manual mixing, hydrogen peroxide was used as a foaming agent and a mixing drill piece was used as a mechanical device to try to induce porosity when mixing the cement. Elution of antibiotic into phosphate-buffered saline was measured from 1 h to 1 week. Surface porosity was calculated from density values which were measured with a density kit and an electronic balance, while total porosity was quantified using micro-computed tomography. Results When a mixing drill piece was used to induce porosity, we observed a significant increasin antibiotic elution compared to a manually mixed ALBC. On the other hand, hydrogen peroxide reduced the elution significantly. Mild correlation between the total amount of cluted in 1 week antibiotic elution and total porosity was observed. Conclusions In terms of improving elution, the mixing drill piece seemed to be efficient. A relationship between surface porosity and elution efficacy was not observed. PMID:19384476

  15. 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.

  16. 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.

  17. Hydrogen Peroxide: A Potential Wound Therapeutic Target.

    PubMed

    Zhu, Guanya; Wang, Qi; Lu, Shuliang; Niu, Yiwen

    2017-04-05

    Hydrogen peroxide (H2O2) is a topical antiseptic used in wound cleaning which kills pathogens through oxidation burst and local oxygen production. Hydrogen peroxide had been reported to be a reactive biochemical molecule synthesized by various cells which influences biological behavior through multiple mechanisms: alterations of membrane potential, generation of new molecules and changing intracellular redox balance which results in activation or inactivation of different signaling transduction pathways. Contrary to the traditional viewpoint that H2O2 probably impairs tissue through its high oxidative property, however, a proper level of H2O2 is considered as an important requirement for normal wound healing. Although the present clinical use of H2O2 is still limited to the elimination of microbial contamination and sometimes hemostasis, better understanding towards the sterilization ability and cell behavior regulatory function of H2O2 within wound will enhance the potential to exogenously augment and manipulate healing.

  18. Gentiana asclepiadea exerts antioxidant activity and enhances DNA repair of hydrogen peroxide- and silver nanoparticles-induced DNA damage.

    PubMed

    Hudecová, Alexandra; Kusznierewicz, Barbara; Hašplová, Katarína; Huk, Anna; Magdolenová, Zuzana; Miadoková, Eva; Gálová, Eliška; Dušinská, Mária

    2012-09-01

    Exposure to high levels of different environmental pollutants is known to be associated with induction of DNA damage in humans. Thus DNA repair is of great importance in preventing mutations and contributes crucially to the prevention of cancer. In our study we have focused on quantitative analysis of Gentiana asclepiadea aqueous or methanolic extracts obtained from flower and haulm, their antioxidant potency in ABTS post-column derivatisation, and their potential ability to enhance DNA repair in human lymphocytes after hydrogen peroxide (H(2)O(2)) treatment (250 μM, 5 min). We also studied DNA repair in human kidney HEK 293 cells after exposure to 20 nm silver nanoparticles (AgNPs) (100 μg/ml, 30 min) in the presence and absence of the plant extract. We have found that mangiferin along with unidentified polar compounds are the most pronounced antioxidants in the studied extracts. Extract from haulm exhibited slightly stronger antioxidant properties compared to flower extracts. However, all four extracts showed significant ability to enhance DNA repair in both cell types after H(2)O(2) and AgNP treatments.

  19. Temperature-induced bifurcations in the Cu(II)-catalyzed and catalyst-free hydrogen peroxide-thiosulfate oscillating reaction.

    PubMed

    Yuan, Ling; Gao, Qingyu; Zhao, Yuemin; Tang, Xiaodong; Epstein, Irving R

    2010-07-08

    We study the oxidation dynamics of thiosulfate ions by hydrogen peroxide in the presence of trace amounts of copper(II) using the reaction temperature as a control parameter in a continuous flow stirred tank reactor. The system displays period-doubling, aperodic, and mixed-mode oscillations at different temperatures. We are able to simulate these complex dynamics with a model proposed by Kurin-Csorgei et al. The model suggests that the Cu(2+)-containing term is not essential for the observed oscillations. We find small-amplitude and high-frequency oscillations in the catalyst-free experimental system. The reaction between H(2)O(2) and S(2)O(3)(2-) contains the core mechanism of the H(2)O(2)-S(2)O(3)(2-)-Cu(2+) and H(2)O(2)-S(2)O(3)(2-)-SO(3)(2-) oscillatory systems, while the Cu(2+) and SO(3)(2-) modulate the feedback loops so as to strengthen the oscillatory dynamics.

  20. Taurine chloramine protects RAW 264.7 macrophages against hydrogen peroxide-induced apoptosis by increasing antioxidants.

    PubMed

    Piao, Shuyu; Cha, Young-Nam; Kim, Chaekyun

    2011-07-01

    Taurine chloramine is the major chloramine generated in activated neutrophils via the reaction between the overproduced hypochlorous acid and the stored taurine. Taurine chloramine has anti-inflammatory and cytoprotective effects in inflamed tissues by inhibiting the production of inflammatory mediators. Taurine chloramine increases heme oxygenase activity and also protects against hydrogen peroxide (H(2)O(2))-derived necrosis in macrophages. In this study, we examined further whether taurine chloramine could protect RAW 264.7 macrophages from apoptosis caused by H(2)O(2). Macrophages treated with 0.4 mM H(2)O(2) underwent apoptosis without showing immediate signs of necrosis, and the cells pretreated with taurine chloramine were protected from the H(2)O(2)-derived apoptosis. Taurine chloramine increased heme oxygenase-1 expression and heme oxygenase activity. The taurine chloramine-derived upregulation of heme oxygenase-1 expression was blocked by inhibition of ERK phosphorylation. Taurine chloramine decreased cellular glutathione (GSH) levels initially, but the GSH level increased above the control level by 10 h. Taurine chloramine also increased catalase expression and protected macrophages from the apoptotic effect of H(2)O(2). Combined, these results indicate that the taurine chloramine, produced and released endogenously by the activated neutrophils, can protect the macrophages in inflamed tissues from the H(2)O(2)-derived apoptosis not only by increasing the expression of cytoprotective enzymes like heme oxygenase-1 and catalase, but also by increasing the intracellular antioxidant GSH level.

  1. 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

  2. Heat and chilling induced disruption of redox homeostasis and its regulation by hydrogen peroxide in germinating rice seeds (Oryza sativa L., Cultivar Ratna).

    PubMed

    Bhattacharjee, Soumen

    2013-04-01

    Extremes of temperature (both heat and chilling) during early inbibitional phase of germination caused disruption of redox-homeostasis by increasing accumulation of reactive oxygen species (superoxide and hydrogen peroxide) and significant reduction of antioxidative defense (assessed in terms of total thiol content and activities of superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase) in germinating tissues of rice (Oryza sativa L., cultivar Ratna). Imbibitional heat and chilling stress also induced oxidative damage to newly assembled membrane system by aggravating membrane lipid peroxidation and protein oxidation [measured in terms of thiobarbituric acid reactive substances (TBARS), free carbonyl content (C = O groups) and membrane protein thiol level (MPTL)]. Treatment with standardized low titer hydrogen peroxide during early imbibitional phase of germination caused significant reversal in oxidative damages to the newly assembled membrane system imposed by heat and chilling stress [evident from the data of TBARS, C = O, MPTL, ROS accumulation, membrane permeability status, membrane injury index and oxidative stress index] in seedlings of experimental rice cultivar. Imbibitional H2O2 pretreatment also caused up-regulation of antioxidative defense (activities of superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase and total thiol content) in the heat and chilling stress-raised rice seedlings. When the parameters of early growth performances were assessed (in terms of relative growth index, biomass accumulation, relative germination performance, mean daily germination, T50 value), it clearly exhibited significant improvement of early growth performances of the experimental rice cultivar. The result proposes that an 'inductive pulse' of H2O2 is required to switch on some stress acclimatory metabolism through which plant restores redox homeostasis and prevents or repairs oxidative damages to newly assembled membrane

  3. 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.

  4. Glycerophosphate-dependent hydrogen peroxide production by rat liver mitochondria.

    PubMed

    Jesina, P; Kholová, D; Bolehovská, R; Cervinková, Z; Drahota, Z; Houstek, J

    2004-01-01

    We studied the extent to which hormonally-induced mitochondrial glycerophosphate dehydrogenase (mGPDH) activity contributes to the supply of reducing equivalents to the mitochondrial respiratory chain in the rat liver. The activity of glycerophosphate oxidase was compared with those of NADH oxidase and/or succinate oxidase. It was found that triiodothyronine-activated mGPDH represents almost the same capacity for the saturation of the respiratory chain as Complex II. Furthermore, the increase of mGPDH activity induced by triiodothyronine correlated with an increase of capacity for glycerophosphate-dependent hydrogen peroxide production. As a result of hormonal treatment, a 3-fold increase in glycerophosphate-dependent hydrogen peroxide production by liver mitochondria was detected by polarographic and luminometric measurements.

  5. 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

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

    PubMed

    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.

  7. Hydrogen peroxide stabilization in one-dimensional flow columns.

    PubMed

    Schmidt, Jeremy T; Ahmad, Mushtaque; Teel, Amy L; Watts, Richard J

    2011-09-25

    Rapid hydrogen peroxide decomposition is the primary limitation of catalyzed H(2)O(2) propagations in situ chemical oxidation (CHP ISCO) remediation of the subsurface. Two stabilizers of hydrogen peroxide, citrate and phytate, were investigated for their effectiveness in one-dimensional columns of iron oxide-coated and manganese oxide-coated sand. Hydrogen peroxide (5%) with and without 25 mM citrate or phytate was applied to the columns and samples were collected at 8 ports spaced 13 cm apart. Citrate was not an effective stabilizer for hydrogen peroxide in iron-coated sand; however, phytate was highly effective, increasing hydrogen peroxide residuals two orders of magnitude over unstabilized hydrogen peroxide. Both citrate and phytate were effective stabilizers for manganese-coated sand, increasing hydrogen peroxide residuals by four-fold over unstabilized hydrogen peroxide. Phytate and citrate did not degrade and were not retarded in the sand columns; furthermore, the addition of the stabilizers increased column flow rates relative to unstabilized columns. These results demonstrate that citrate and phytate are effective stabilizers of hydrogen peroxide under the dynamic conditions of one-dimensional columns, and suggest that citrate and phytate can be added to hydrogen peroxide before injection to the subsurface as an effective means for increasing the radius of influence of CHP ISCO.

  8. Hydrogen peroxide stabilization in one-dimensional flow columns

    NASA Astrophysics Data System (ADS)

    Schmidt, Jeremy T.; Ahmad, Mushtaque; Teel, Amy L.; Watts, Richard J.

    2011-09-01

    Rapid hydrogen peroxide decomposition is the primary limitation of catalyzed H 2O 2 propagations in situ chemical oxidation (CHP ISCO) remediation of the subsurface. Two stabilizers of hydrogen peroxide, citrate and phytate, were investigated for their effectiveness in one-dimensional columns of iron oxide-coated and manganese oxide-coated sand. Hydrogen peroxide (5%) with and without 25 mM citrate or phytate was applied to the columns and samples were collected at 8 ports spaced 13 cm apart. Citrate was not an effective stabilizer for hydrogen peroxide in iron-coated sand; however, phytate was highly effective, increasing hydrogen peroxide residuals two orders of magnitude over unstabilized hydrogen peroxide. Both citrate and phytate were effective stabilizers for manganese-coated sand, increasing hydrogen peroxide residuals by four-fold over unstabilized hydrogen peroxide. Phytate and citrate did not degrade and were not retarded in the sand columns; furthermore, the addition of the stabilizers increased column flow rates relative to unstabilized columns. These results demonstrate that citrate and phytate are effective stabilizers of hydrogen peroxide under the dynamic conditions of one-dimensional columns, and suggest that citrate and phytate can be added to hydrogen peroxide before injection to the subsurface as an effective means for increasing the radius of influence of CHP ISCO.

  9. Metabolic responses of Beauveria bassiana to hydrogen peroxide-induced oxidative stress using an LC-MS-based metabolomics approach.

    PubMed

    Zhang, Chen; Wang, Wei; Lu, Ruili; Jin, Song; Chen, Yihui; Fan, Meizhen; Huang, Bo; Li, Zengzhi; Hu, Fenglin

    2016-06-01

    The entomopathogenic fungus, Beauveria bassiana, is commonly used as a biological agent for pest control. Environmental and biological factors expose the fungus to oxidative stress; as a result, B. bassiana has adopted a number of anti-oxidant mechanisms. In this study, we investigated metabolites of B. bassiana that are formed in response to oxidative stress from hydrogen peroxide (H2O2) by using a liquid chromatography mass spectrometry (LC-MS) approach. Partial least-squares discriminant analysis (PLS-DA) revealed differences between the control and the H2O2-treated groups. Hierarchical cluster analysis (HCA) showed 18 up-regulated metabolites and 25 down-regulated metabolites in the H2O2-treated fungus. Pathway analysis indicated that B. bassiana may be able to alleviate oxidative stress by enhancing lipid catabolism and glycometabolism, thus decreasing membrane polarity and preventing polar H2O2 or ROS from permeating into fungal cells and protecting cells against oxidative injury. Meanwhile, most of the unsaturated fatty acids that are derived from glycerophospholipids hydrolysis can convert into oxylipins through autoxidation, which can prevent the reactive oxygen of H2O2 from attacking important macromolecules of the fungus. Results showed also that H2O2 treatment can enhance mycotoxins production which implies that oxidative stress may be able to increase the virulence of the fungus. In comparison to the control group, citric acid and UDP-N-acetylglucosamine were down-regulated, which suggested that metabolic flux was occurring to the TCA cycle and enhancing carbohydrate metabolism. The findings from this study will contribute to the understanding of how the molecular mechanisms of fungus respond to environmental and biological stress factors as well as how the manipulation of such metabolisms may lead to selection of more effective fungal strains for pest control.

  10. 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.

  11. 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.

  12. Inhibitory heterotrimeric GTP-binding proteins inhibit hydrogen peroxide-induced apoptosis by up-regulation of Bcl-2 via NF-kappaB in H1299 human lung cancer cells.

    PubMed

    Seo, Miran; 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 (Galphai1QL), Gi2, or Gi3 inhibited hydrogen peroxide-induced apoptosis. The expression of Galphai1QL up-regulated Bcl-2 expression, and the knockdown of Bcl-2 with siRNA abolished the anti-apoptotic effect of Galphai1QL. Galphai1 induced the transcription of Bcl-2 by activation of NF-kappaB, which resulted from an increase in NF-kappaB p50 protein. We conclude that Galphai1 inhibits hydrogen peroxide-induced apoptosis of H1299 lung cancer cells by up-regulating the transcription of Bcl-2 through a p50-mediated NF-kappaB activation.

  13. The Arabidopsis Prohibitin Gene PHB3 Functions in Nitric Oxide-Mediated Responses and in Hydrogen Peroxide-Induced Nitric Oxide Accumulation.

    PubMed

    Wang, Yong; Ries, Amber; Wu, Kati; Yang, Albert; Crawford, Nigel M

    2010-01-01

    To discover genes involved in nitric oxide (NO) metabolism, a genetic screen was employed to identify mutants defective in NO accumulation after treatment with the physiological inducer hydrogen peroxide. In wild-type Arabidopsis thaliana plants, NO levels increase eightfold in roots after H(2)O(2) treatment for 30 min. A mutant defective in H(2)O(2)-induced NO accumulation was identified, and the corresponding mutation was mapped to the prohibitin gene PHB3, converting the highly conserved Gly-37 to an Asp in the protein's SPFH domain. This point mutant and a T-DNA insertion mutant were examined for other NO-related phenotypes. Both mutants were defective in abscisic acid-induced NO accumulation and stomatal closure and in auxin-induced lateral root formation. Both mutants were less sensitive to salt stress, showing no increase in NO accumulation and less inhibition of primary root growth in response to NaCl treatment. In addition, light-induced NO accumulation was dramatically reduced in cotyledons. We found no evidence for impaired H(2)O(2) metabolism or signaling in the mutants as H(2)O(2) levels and H(2)O(2)-induced gene expression were unaffected by the mutations. These findings identify a component of the NO homeostasis system in plants and expand the function of prohibitin genes to include regulation of NO accumulation and NO-mediated responses.

  14. 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.

  15. 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.

  16. Oxygen from Hydrogen Peroxide: An Experimental Modification

    NASA Astrophysics Data System (ADS)

    Burness, James H.

    1996-09-01

    A common experiment, performed at the high school and college levels, is the generation of a gas to explore molar mass and molar volume relationships. In one version of this experiment, hydrogen peroxide is decomposed by yeast to generate oxygen gas. This paper describes a simple modification to this experiment which eliminates the need for a pencil coated with petroleum jelly and dry yeast. This elimination not only prevents falling pieces of yeast from prematurely starting the reaction, but at the same time makes the reaction faster and simplifies cleanup. The modification also reduces the likelihood of cuts from broken tubing.

  17. 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.

  18. 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.

  19. 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.

  20. Localized surface plasmon resonance sensor for simultaneous kinetic determination of peroxyacetic acid and hydrogen peroxide.

    PubMed

    Tashkhourian, Javad; Hormozi-Nezhad, Mohammad Reza; Khodaveisi, Javad; Dashti, Razieh

    2013-01-31

    A new sensor for simultaneous determination of peroxyacetic acid and hydrogen peroxide using silver nanoparticles (Ag-NPs) as a chromogenic reagent is introduced. The silver nanoparticles have the catalytic ability for the decomposition of peroxyacetic acid and hydrogen peroxide; then the decomposition of them induces the degradation of silver nanoparticles. Hence, a remarkable change in the localized surface plasmon resonance absorbance strength could be observed. Spectra-kinetic approach and artificial neural network was applied for the simultaneous determination of peroxyacetic acid and hydrogen peroxide. Linear calibration graphs were obtained in the concentration range of (8.20×10(-5) to 2.00×10(-3) mol L(-1)) for peroxyacetic acid and (2.00×10(-5) to 4.80×10(-3) mol L(-1)) for hydrogen peroxide. The analytical performance of this sensor has been evaluated for the detection of simultaneous determination of peroxyacetic acid and hydrogen peroxide in real samples.

  1. [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.

  2. 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.

  3. 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.

  4. 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.

  5. Manganese Potentiates LPS-Induced Heme-Oxygenase 1 in Microglia but not Dopaminergic Cells: Role in Controlling Microglial Hydrogen Peroxide and Inflammatory Cytokine Output

    PubMed Central

    Dodd, Celia A.; Filipov, Nikolay M.

    2012-01-01

    Excessive manganese (Mn) exposure increases output of glial-derived inflammatory products, which may indirectly contribute to the neurotoxic effects of this essential metal. In microglia, Mn increases hydrogen peroxide (H2O2) release and potentiates lipopolysaccharide (LPS)-induced cytokines (TNF-α, IL-6) and nitric oxide (NO). Inducible heme-oxygenase (HO-1) plays a role in the regulation of inflammation and its expression is upregulated in response to oxidative stressors, including metals and LPS. Because Mn can oxidatively affect neurons both directly and indirectly, we investigated the effect of Mn exposure on the induction of HO-1 in resting and LPS-activated microglia (N9) and dopaminergic neurons (N27). In microglia, 24 h exposure to Mn (up to 250 μM) had minimal effects on its own, but it markedly potentiated LPS (100 ng/ml)-induced HO-1protein and mRNA. Inhibition of microglial HO-1 activity with two different inhibitors indicated that HO-1 is a positive regulator of the Mn-potentiated cytokine output and a negative regulator of the Mn-induced H2O2 output. Mn enhancement of LPS-induced HO-1 does not appear to be dependent on H2O2 or NO, as Mn+LPS-induced H2O2 release was not greater than the increase induced by Mn alone and inhibition of iNOS did not change Mn potentiation of HO-1. However, because Mn exposure potentiated the LPS-induced nuclear expression of small Maf proteins, this may be one mechanism Mn uses to affect the expression of HO-1 in activated microglia. Finally, the potentiating effects of Mn on HO-1 appear to be glia-specific for Mn, LPS, or Mn+LPS did not induce HO-1 in N27 neuronal cells. PMID:21963524

  6. 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

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

    DOEpatents

    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.

  8. Hydrogen peroxide and nitric oxide mediated cold- and dehydration-induced myo-inositol phosphate synthase that confers multiple resistances to abiotic stresses.

    PubMed

    Tan, Jiali; Wang, Congying; Xiang, Bin; Han, Ruihong; Guo, Zhenfei

    2013-02-01

    myo-Inositol phosphate synthase (MIPS) is the key enzyme of myo-inositol synthesis, which is a central molecule required for cell metabolism and plant growth as a precursor to a large variety of compounds. A full-length fragment of MfMIPS1 cDNA was cloned from Medicago falcata that is more cold-tolerant than Medicago sativa. While MfMIPS1 transcript was induced in response to cold, dehydration and salt stress, MIPS transcript and myo-inositol were maintained longer and at a higher level in M. falcata than in M. sativa during cold acclimation at 5 °C. MfMIPS1 transcript was induced by hydrogen peroxide (H(2) O(2)) and nitric oxide (NO), but was not responsive to abscisic acid (ABA). Pharmacological experiments revealed that H(2) O(2) and NO are involved in the regulation of MfMIPS1 expression by cold and dehydration, but not by salt. Overexpression of MfMIPS1 in tobacco increased the MIPS activity and levels of myo-inositol, galactinol and raffinose, resulting in enhanced resistance to chilling, drought and salt stresses in transgenic tobacco plants. It is suggested that MfMIPS1 is induced by diverse environmental factors and confers resistance to various abiotic stresses.

  9. 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.

  10. Cadmium-induced accumulation of hydrogen peroxide in the leaf apoplast of Phaseolus aureus and Vicia sativa and the roles of different antioxidant enzymes.

    PubMed

    Zhang, Fenqin; Zhang, Hongxiao; Wang, Guiping; Xu, Langlai; Shen, Zhenguo

    2009-08-30

    The effects of cadmium (Cd) on the accumulation of hydrogen peroxide (H(2)O(2)) and superoxide anion (O(2)(-)) in leaves of Phaseolus aureus and Vicia sativa were investigated. Cadmium at 100 microM significantly increased the production of O(2)(-) and H(2)O(2), as well as the activities of plasma membrane-bound nicotinamide adenine dinucleotide phosphate (NADPH) oxidases and the symplastic and apoplastic activities of superoxide dismutase and ascorbate peroxidase in the leaves of both species. Apoplastic guaiacol peroxidase activity was significantly induced in the leaves of both species, particularly in P. aureus exposed to 100 microM Cd. Experiments with diphenylene iodonium as an inhibitor of NADPH oxidase and NaN(3) as an inhibitor of peroxidase showed that the majority of Cd-induced reactive oxygen species production in the leaves of both species may involve plasma membrane-bound NADPH oxidase and apoplastic peroxidase. Compared to V. sativa, increases in Cd-induced production of O(2)(-) and H(2)O(2) and activities of NADPH oxidase and apoplastic peroxidase were more pronounced in P. aureus. In contrast, V. sativa had higher leaf symplastic superoxide dismutase and ascorbate peroxidase activities than P. aureus. The results indicated that V. sativa was more tolerant to Cd than P. aureus.

  11. Akt attenuates apoptotic death through phosphorylation of H2A under hydrogen peroxide-induced oxidative stress in PC12 cells and hippocampal neurons

    PubMed Central

    Park, Ji Hye; Kim, Chung Kwon; Lee, Sang Bae; Lee, Kyung-Hoon; Cho, Sung-Woo; Ahn, Jee-Yin

    2016-01-01

    Although the essential role of protein kinase B (PKB)/Akt in cell survival signaling has been clearly established, the mechanism by which Akt mediates the cellular response to hydrogen peroxide (H2O2)-induced oxidative stress remains unclear. We demonstrated that Akt attenuated neuronal apoptosis through direct association with histone 2A (H2A) and phosphorylation of H2A at threonine 17. At early time points during H2O2 exposure of PC12 cells and primary hippocampal neurons, when the cells can tolerate the level of DNA damage, Akt was activated and phosphorylated H2A, leading to inhibition of apoptotic death. At later time points, Akt delivered the NAD+-dependent protein deacetylase Sirtuin 2 (Sirt 2) to the vicinity of phosphorylated H2A in response to irreversible DNA damage, thereby inducing H2A deacetylation and subsequently leading to apoptotic death. Ectopically expressed T17A-substituted H2A minimally interacted with Akt and failed to prevent apoptosis under oxidative stress. Thus Akt-mediated H2A phosphorylation has an anti-apoptotic function in conditions of H2O2-induced oxidative stress in neurons and PC12 cells. PMID:26899247

  12. Switching off hydrogen peroxide hydrogenation in the direct synthesis process.

    PubMed

    Edwards, Jennifer K; Solsona, Benjamin; N, Edwin Ntainjua; Carley, Albert F; Herzing, Andrew A; Kiely, Christopher J; Hutchings, Graham J

    2009-02-20

    Hydrogen peroxide (H2O2) is an important disinfectant and bleach and is currently manufactured from an indirect process involving sequential hydrogenation/oxidation of anthaquinones. However, a direct process in which H2 and O2 are reacted would be preferable. Unfortunately, catalysts for the direct synthesis of H2O2 are also effective for its subsequent decomposition, and this has limited their development. We show that acid pretreatment of a carbon support for gold-palladium alloy catalysts switches off the decomposition of H2O2. This treatment decreases the size of the alloy nanoparticles, and these smaller nanoparticles presumably decorate and inhibit the sites for the decomposition reaction. Hence, when used in the direct synthesis of H2O2, the acid-pretreated catalysts give high yields of H2O2 with hydrogen selectivities greater than 95%.

  13. 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.

  14. Activation of AMPK protects against hydrogen peroxide-induced osteoblast apoptosis through autophagy induction and NADPH maintenance: new implications for osteonecrosis treatment?

    PubMed

    She, Chang; Zhu, Lun-qing; Zhen, Yun-fang; Wang, Xiao-dong; Dong, Qi-rong

    2014-01-01

    Elevated hydrogen peroxide (H2O2) causes osteoblast dysfunction and apoptosis, serving as an important contributor to the development of osteonecrosis. Here we aimed to understand the role of AMP-activated protein kinase (AMPK) in the process. We observed a high level of AMPK activation in surgery isolated patients' osteonecrosis tissues. In cultured osteoblastoma MG63 cells, H2O2 stimulation induced significant AMPK activation, oxidative stress, cell death and apoptosis. Inhibition of AMPK by its inhibitor (compound C) or by shRNA-mediated knockdown dramatically enhanced H2O2-induced MG63 cell apoptosis, while over-expression of AMPK in HEK-293 cells alleviated H2O2-induced cell damage. These results confirmed that H2O2-activated AMPK is pro-cell survival. We observed that H2O2 induced protective autophagy in MG63 cells, and AMPK-dependent Ulk1 activation and mTORC1 (mTOR complex 1) inactivation might involve autophagy activation. Further, AMPK activation inhibited H2O2-induced oxidative stress, probably through inhibiting NADPH (nicotinamide adenine dinucleotide phosphate) depletion, since more NADPH depletion and oxidative stress were induced by H2O2 in AMPK deficient MG63 cells. Finally, we observed a significant AMPK activation in H2O2-treated primary cultured and transformed (MC3T3-E1) osteoblasts, and AMPK inhibitor compound C enhanced death by H2O2 in these cells. Based on these results, we concluded that H2O2-induced AMPK activation is pro-survival and anti-apoptosis in osteoblasts. Autophagy induction and NADPH maintenance are involved in AMPK-mediated pro-survival effects. AMPK might represent a novel molecular target for osteonecrosis treatment.

  15. 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)

  16. A Volumetric Method for Titrimetric Analysis of Hydrogen Peroxide

    DTIC Science & Technology

    1985-05-06

    side it necessary and iden~tify by block nambet) *Hydrogen Peroxide Quantitative Analysis *Potassium Dichromate * Volumetrie Analysis,~ Ferrous Ammonium ...report describes a titrimetric method (using ferrous- dichromate oxidation reduction) of analysis for hydrogen peroxide. The concept is theoretically...2 COMPARISON OF FERROUS SOLUTION TO DICHROMATE SOLUTION . . . . . . . . .. 3 PROCEDURE . . . . . . . . . . . . . . . . . 3 CALCULATIONS

  17. Farrerol regulates occludin expression in hydrogen peroxide-induced EA.hy926 cells by modulating ERK1/2 activity.

    PubMed

    Li, Jiankuan; Ge, Rui; Zhao, Chengxiao; Tang, Li; Li, Jianguo; Li, Qingshan

    2014-07-05

    Endothelial tight junction is a crucial intracellular junctional structure that controls paracellular permeability across vascular endothelium. Oxidative stress-mediated elevation in endothelial permeability is associated with pathogenesis of several cardiovascular diseases. In the present research, the regulation of farrerol on occludin, a transmembrane proteins associated with endothelial tight junction, was investigated in hydrogen peroxide-induced human endothelium-derived EA.hy926 cells. Western blot analysis demonstrated that H2O2 exposure caused a significant decrease in occludin expression, but had little effect on ZO-1 expression, and the decrease of occludin expression was significantly attenuated by farrerol in a dose-dependent manner. Meanwhile, immunofluorescent staining assay also demonstrated that the loss of occludin expression induced by H2O2 exposure was restored by farrerol pretreatment. Further investigations showed that farrerol prevented H2O2-induced activation of extracellular signal-regulated kinase (ERK) 1/2 in a dose-dependent manner. The use of U0126, a specific inhibitor of MEK1/2, proved that H2O2-induced decrease of occludin in EA.hy926 cells was likely associated with activation of ERK1/2, which indicated that the regulation of farrerol on occludin expression in H2O2-induced EA.hy926 cells was likely related to the modulation of ERK1/2 activation. In conclusion, the present study demonstrates for the first time that farrerol has potential effects on oxidative stress-induced endothelial tight junction disruption and suggests that farrerol is a potential candidate for the intervention of endothelial permeability-associated cardiovascular diseases.

  18. Hydrogen peroxide measurements in the marine atmosphere

    NASA Astrophysics Data System (ADS)

    Jacob, P.; Klockow, D.

    1992-11-01

    Hydrogen peroxide, one of the key compounds in multiphase atmospheric chemistry, was measured on an Atlantic cruise (ANT VII/1) of the German research vessel Polarstern from 15 September to 9 October 1988, in rain and ambient air by a chemiluminescence technique. For gas-phase H2O2 cryogenic sampling was employed. The presented results show an increase of gas-phase mixing ratios of about 45 pptv per degree latitude between 50 deg N and 0 deg, and a maximum of 3.5 ppbv around the equator. Generally higher mixing ratios were observed in the Southern Hemisphere, with a clear diurnal variation. The H2O2 mixing ratio is correlated to the UV radiation intensity and to the temperature difference between air and ocean surface water.

  19. 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.

  20. Hydrogen Peroxide (HP) Potential for Space Applications

    NASA Astrophysics Data System (ADS)

    Grafwallner, F.

    2004-10-01

    Low toxicity or "green" propellants are now under study by organizations around the world. Especially ultra high concentrated hydrogen peroxide (HP) may be a significant step toward less toxic, storable und safer operation of upper stages and spacecrafts. HP can be used as a monopropellant, when catalytically decomposed or as a bipropellant constituting the propellant combination`s oxidizer. Serving as a monopropellant, catalytic decomposition will result in exhaust of superheated steam and oxygen which can be used to drive gas turbines and feed life support systems or provide thrust as a monopropellant, provide the oxidizer, or function as an igniter for bipropellant engines. HP can be used in fuel cells to produce electrical power, heat and water.

  1. 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.

  2. Hydrogen peroxide in the human body.

    PubMed

    Halliwell, B; Clement, M V; Long, L H

    2000-12-01

    Hydrogen peroxide (H(2)O(2)) is widely regarded as a cytotoxic agent whose levels must be minimized by the action of antioxidant defence enzymes. In fact, H(2)O(2) is poorly reactive in the absence of transition metal ions. Exposure of certain human tissues to H(2)O(2) may be greater than is commonly supposed: substantial amounts of H(2)O(2) can be present in beverages commonly drunk (especially instant coffee), in freshly voided human urine, and in exhaled air. Levels of H(2)O(2) in the human body may be controlled not only by catabolism but also by excretion, and H(2)O(2) could play a role in the regulation of renal function and as an antibacterial agent in the urine. Urinary H(2)O(2) levels are influenced by diet, but under certain conditions might be a valuable biomarker of 'oxidative stress'.

  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. 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.

  5. Potential Protective Effects of Bioactive Constituents from Chinese Propolis against Acute Oxidative Stress Induced by Hydrogen Peroxide in Cardiac H9c2 Cells

    PubMed Central

    Xu, Xiang; Ge, Miaomiao

    2017-01-01

    Chinese propolis (CP) is known as a health food but its beneficial effects in protecting cardiomyocytes remain elusive. Here, we investigated the effects of CP and its active compounds on hydrogen peroxide (H2O2) induced rats cardiomyocytes (H9c2) oxidative injury. Cell viability decreases induced by H2O2 were mitigated by different CP extracts using various solvents. From these active fractions, six active compounds were separated and identified. Among tested isolated compound, the cytoprotective activities of three caffeates, caffeic acid phenethyl ester (CAPE), benzyl caffeate (BZC), and cinnamyl caffeate (CNC), exerted stronger effects than chrysin, pinobanksin, and 3,4-dimethoxycinnamic acid (DMCA). These three caffeates also increased H9c2 cellular antioxidant potential, decreased intracellular calcium ion ([Ca2+]i) level, and prevented cell apoptosis. Overall, the cardiovascular protective effects of the CP might be attributed to its caffeates constituents (CAPE, BZC, and CNC) and provide evidence for its usage in complementary and alternative medicine. PMID:28337227

  6. Carbocisteine attenuates hydrogen peroxide-induced inflammatory injury in A549 cells via NF-κB and ERK1/2 MAPK pathways.

    PubMed

    Wang, Wei; Zheng, Jin-Ping; Zhu, Shao-Xuan; Guan, Wei-Jie; Chen, Mao; Zhong, Nan-Shan

    2015-02-01

    Carbocisteine is a mucolytic drug with anti-oxidative effect, we had previously proved that carbocisteine remarkably reduced the rate of acute exacerbations and improved the quality of life in patients with chronic obstructive pulmonary disease (COPD), however, very little is known about its mechanisms. In this study, we aimed to investigate the anti-inflammatory effects of carbocisteine against hydrogen peroxide (H2O2). A549 cells were cultured in vitro and treated with H2O2 as damaged cell models, carbocisteine was administered 24h prior to or after H2O2 exposure, and the protective effects of carbocisteine were determined by MTT, qRT-PCR, ELISA, western blot and immunofluorescence assays. The results showed that carbocisteine could increase cell viability and decrease LDH, IL-6 and IL-8 levels in the supernatant. Additionally, carbocisteine decreased IL-6, IL-8, TNF-α, IP-10 and MIP-1β mRNA in a dose-dependent manner. Moreover, carbocisteine could attenuate phosphorylation of NF-κB p65 and ERK1/2 and inhibit the nuclear translocation of pNF-κB p65 induced by H2O2. In conclusion, carbocisteine inhibited H2O2-induced inflammatory injury in A549 cells, NF-κB and ERK1/2 MAPK were the target pathways.

  7. Protective Effect of 2,4',5'-Trihydroxyl-5,2'-dibromo diphenylmethanone, a New Halophenol, against Hydrogen Peroxide-Induced EA.hy926 Cells Injury.

    PubMed

    Li, Jianguo; Feng, Xiue; Ge, Rui; Li, Jiankuan; Li, Qingshan

    2015-08-05

    Vascular endothelial cells produce reactive oxygen species (ROS) during the process of energy metabolism in aerobic respiration. A growing body of evidence indicates that excessive ROS is implicated in the pathogenesis of cardiovascular diseases including atherosclerosis. The newly synthesized halophenol, 2,4',5'-trihydroxyl-5,2'-dibromo diphenylmethanone (TDD), exhibits antioxidative and cytoprotective activities in vitro. In this study, the protective effect of TDD against hydrogen peroxide (H2O2)-induced oxidative injury of EA.hy926 cells was investigated. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-dephenyltetrazolium bromide (MTT) assay, while the effect of TDD on the transcription profile of EA.hy926 cells subjected to H2O2-induced oxidative injury was evaluated by microarray analysis. Several signaling pathways, including apoptosis, were significantly associated with TDD. Flow cytometric analysis was used to evaluate anti-apoptotic effect of TDD. Subsequently, RT-PCR and Western blot were used to detect the expressions of the apoptosis-associated protein, Bcl-2 and Bax. Meanwhile the expression of cleaved caspase-3, an executioner of apoptosis, was also detected by Western blot. The results showed that pretreatment of EA.hy926 cells with TDD prevented the decrease of cell viability induced by H2O2, and attenuated H2O2-induced elevation of Bax and cleaved caspase-3 while increased Bcl-2 expressions. In summary, TDD inhibited H2O2-induced oxidative injury of EA.hy926 cells through negative regulation of apoptosis. These findings suggest that TDD is a potential candidate for therapeutic intervention in oxidative stress-associated cardiovascular diseases.

  8. 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

  9. 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

    2016-07-12

    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.

  10. 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.

  11. Hydrogen peroxide mediates EGF-induced down-regulation of E-cadherin expression via p38 MAPK and snail in human ovarian cancer cells.

    PubMed

    Cheng, Jung-Chien; Klausen, Christian; Leung, Peter C K

    2010-08-01

    In ovarian cancer, it has been shown that E-cadherin is down-regulated by epidermal growth factor (EGF) receptor (EGFR) activation, and that cells with low E-cadherin expression are particularly invasive. Although it is generally believed that reactive oxygen species play important roles in intracellular signal transduction, the role of reactive oxygen species in EGF-mediated reductions in E-cadherin remains to be elucidated. In this study, we show that EGF treatment down-regulated E-cadherin by up-regulating its transcriptional repressors, Snail and Slug, in human ovarian cancer cells. Using 5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate acetyl ester staining, we found that intracellular hydrogen peroxide (H(2)O(2)) production was increased in EGF-treated cells and could be inhibited by treatment with an EGFR inhibitor, AG1478, or an H(2)O(2) scavenger, polyethylene glycol (PEG)-catalase. In addition, PEG-catalase diminished EGF-induced p38 MAPK, but not ERK1/2 or c-Jun N-terminal kinase, phosphorylation. PEG-catalase and the p38 MAPK inhibitor SB203580 abolished EGF-induced Snail, but not Slug, expression and E-cadherin down-regulation. Furthermore, the involvement of p38 MAPK in the down-regulation of E-cadherin was confirmed using specific p38alpha MAPK small interfering RNA. Finally, we also show that EGF-induced cell invasion was abolished by treatment with PEG-catalase and SB203580, as well as p38alpha MAPK small interfering RNA, and that forced expression of E-cadherin diminished intrinsic invasiveness as well as EGF-induced cell invasion. This study demonstrates a novel mechanism in which EGF down-regulates E-cadherin expression through production of H(2)O(2), activation of p38 MAPK, and up-regulation of Snail in human ovarian cancer cells.

  12. Aloperine attenuates hydrogen peroxide-induced injury via anti-apoptotic activity and suppression of the nuclear factor-κB signaling pathway

    PubMed Central

    Ren, Dongliang; Ma, Weisong; Guo, Baozhen; Wang, Shunyi

    2017-01-01

    Aloperine is an alkaloid that exerts significant inhibitive effects on acute inflammation and Type III and IV hypersensitivity caused by a variety of inflammatory agents. The aims of the present study were to investigate whether the protective effect of aloperine attenuates hydrogen peroxide (H2O2)-induced injury, and to identify the underlying mechanisms involved. Nucleus pulposus cells were extracted from adult male Sprague-Dawley rats, and incubated with fresh medium containing 200 µM H2O2 for 24 h. In the study, treatment with aloperine significantly increased cell viability and suppressed apoptosis in H2O2-treated nucleus pulposus cells in a dose-dependent manner. In addition, 10 and 100 nM aloperine significantly inhibited H2O2-induced tumor necrosis factor-α and interleukin-6 activities, and significantly increased the H2O2-reduced superoxide dismutase and glutathione peroxidase activities in nucleus pulposus cells (all P<0.01). However, aloperine treatment (10 and 100 nM) significantly reduced the H2O2-induced caspase-9 activity in nucleus pulposus cells. Furthermore, addition of 10 and 100 nM aloperine significantly suppressed nuclear factor-κB (NF-κB) and phosphorylated-protein kinase B expression levels in H2O2-treated nucleus pulposus cells. In conclusion, the protective effect of aloperine attenuated H2O2-induced injury via hyperproliferation, its anti-apoptotic activity and suppression of the NF-κB signaling pathway. PMID:28123508

  13. 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.

  14. Marine Photochemistry of Hydrogen Peroxide in the Northwest Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Yuan, J.; Shiller, A. M.

    2002-12-01

    A systematical study of hydrogen peroxide in seawater, rainwater, and marine air in the Northwest Pacific Ocean was conducted during a transect from Osaka, Japan, to Hawaii, USA, in May and June of 2002. During the transect, surface seawater samples were analyzed continuously for peroxide which showed the effects of photochemical production, wet deposition, and terrestrial impact. In the surface waters, hydrogen peroxide decreased with latitude from a little over 25 nM in the north (50°N) to more than 150 nM in the south (22°N). This latitudinal variation of hydrogen peroxide followed a trend similar to shipboard measurement of ultraviolet radiation. Diel variations of surface hydrogen peroxide were observed at several locations, with surface water concentrations increasing during the day and decreasing at night. The concentration of surface water peroxide increased to over 200 nM following rain events. Higher concentrations of hydrogen peroxide (>150 nM) were also observed near Asia. The profiles of hydrogen peroxide were obtained at 10 stations that exhibited surface maxima of 24 to 120 nM. The rate constant of dark decay varied from 0.08 d-1 to 0.22 d-1. Rate of photo-production decreased from 10 nM hr-1 at noon to 0 at night. The concentration of hydrogen peroxide varied from 16 μM to 526 μM in rainwater. The data set permits a systematical analysis and modeling of factors regulating the dynamics of hydrogen peroxide in marine environment.

  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.

  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. Nitric oxide is involved in the oxytetracycline-induced suppression of root growth through inhibiting hydrogen peroxide accumulation in the root meristem

    NASA Astrophysics Data System (ADS)

    Yu, Qing-Xiang; Ahammed, Golam Jalal; Zhou, Yan-Hong; Shi, Kai; Zhou, Jie; Yu, Yunlong; Yu, Jing-Quan; Xia, Xiao-Jian

    2017-02-01

    Use of antibiotic-contaminated manure in crop production poses a severe threat to soil and plant health. However, few studies have studied the mechanism by which plant development is affected by antibiotics. Here, we used microscopy, flow cytometry, gene expression analysis and fluorescent dyes to study the effects of oxytetracycline (OTC), a widely used antibiotic in agriculture, on root meristem activity and the accumulation of hydrogen peroxide (H2O2) and nitric oxide (NO) in the root tips of tomato seedlings. We found that OTC caused cell cycle arrest, decreased the size of root meristem and inhibited root growth. Interestingly, the inhibition of root growth by OTC was associated with a decline in H2O2 levels but an increase in NO levels in the root tips. Diphenyliodonium (DPI), an inhibitor of H2O2 production, showed similar effects on root growth as those of OTC. However, exogenous H2O2 partially reversed the effects on the cell cycle, meristem size and root growth. Importantly, cPTIO (the NO scavenger) and tungstate (an inhibitor of nitrate reductase) significantly increased H2O2 levels in the root tips and reversed the inhibition of root growth by OTC. Out results suggest that OTC-induced NO production inhibits H2O2 accumulation in the root tips, thus leading to cell cycle arrest and suppression of root growth.

  18. Nitric oxide is involved in the oxytetracycline-induced suppression of root growth through inhibiting hydrogen peroxide accumulation in the root meristem

    PubMed Central

    Yu, Qing-Xiang; Ahammed, Golam Jalal; Zhou, Yan-Hong; Shi, Kai; Zhou, Jie; Yu, Yunlong; Yu, Jing-Quan; Xia, Xiao-Jian

    2017-01-01

    Use of antibiotic-contaminated manure in crop production poses a severe threat to soil and plant health. However, few studies have studied the mechanism by which plant development is affected by antibiotics. Here, we used microscopy, flow cytometry, gene expression analysis and fluorescent dyes to study the effects of oxytetracycline (OTC), a widely used antibiotic in agriculture, on root meristem activity and the accumulation of hydrogen peroxide (H2O2) and nitric oxide (NO) in the root tips of tomato seedlings. We found that OTC caused cell cycle arrest, decreased the size of root meristem and inhibited root growth. Interestingly, the inhibition of root growth by OTC was associated with a decline in H2O2 levels but an increase in NO levels in the root tips. Diphenyliodonium (DPI), an inhibitor of H2O2 production, showed similar effects on root growth as those of OTC. However, exogenous H2O2 partially reversed the effects on the cell cycle, meristem size and root growth. Importantly, cPTIO (the NO scavenger) and tungstate (an inhibitor of nitrate reductase) significantly increased H2O2 levels in the root tips and reversed the inhibition of root growth by OTC. Out results suggest that OTC-induced NO production inhibits H2O2 accumulation in the root tips, thus leading to cell cycle arrest and suppression of root growth. PMID:28220869

  19. Protective effect of the ultra-filtration extract from Xin Mai Jia on human aortic smooth muscle cell injury induced by hydrogen peroxide

    PubMed Central

    WAN, JIA; YIN, YALING; SUN, RUILI; PAN, GUOPIN; LI, PENG; JIA, YANLONG; WAN, GUANGRUI; LIU, ZHANG-SUO

    2014-01-01

    The aim of the present study was to explore whether an ultra-filtration extract from Xin Mai Jia (XMJ), a Chinese medicinal formulation, has a protective effect on human aortic smooth muscle cell (HASMC) injury models induced by hydrogen peroxide (H2O2), and to consider the mechanism and efficacy of the therapeutic action of XMJ on atherosclerosis. HASMCs were injured by H2O2 and then exposed to various concentrations of XMJ. The morphological changes, growth, proliferation, migration and cytokine release of HASMCs were detected using 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT), an enzyme-linked immunosorbent assay and a scratch adhesion test. H2O2 significantly promoted the proliferation of HASMCs. The ultra-filtration extract from XMJ was observed to significantly attenuate the morphological changes of injured HASMCs, reduce the expression levels of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), interleukin (IL)-1, IL-6 and nuclear factor (NF)-κB, and increase the expression levels of matrix metalloproteinase (MMP)-2 and tissue inhibitor of metalloproteinase (TIMP). XMJ has clear anti-inflammatory and antioxidant effects, and significantly inhibits the proliferation and migration of HASMCs. PMID:24348756

  20. 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.

  1. β-Carotene and lutein inhibit hydrogen peroxide-induced activation of NF-κB and IL-8 expression in gastric epithelial AGS cells.

    PubMed

    Kim, Youngha; Seo, Ji Hye; Kim, Hyeyoung

    2011-01-01

    Reactive oxygen species (ROS) including hydrogen peroxide (H(2)O(2)) are involved in the pathogenesis of gastric inflammation. Interleukin-8 (IL-8) is a potent mediator of the inflammatory response by activating and recruiting neutrophils to the site of infection. Oxidant-sensitive transcription factor NF-κB regulates the expression of IL-8 in the immune and inflammatory events. Carotenoids (carotenes and oxygenated carotenoids) show antioxidant and anti-inflammatory activities. Low intake of β-carotene leads to high risk of gastric cancer. Oxygenated carotenoid lutein inhibited NF-κB activation in experimental uveitis. The present study aims to investigate whether β-carotene and lutein inhibit H(2)O(2)-induced activation of NF-κB and expression of IL-8 in gastric epithelial AGS cells. The cells were treated with carotenoids 2 h prior to the treatment of H(2)O(2). mRNA expression was analyzed by reverse transcription-polymerase chain reaction (RT-PCR) and real time RT-PCR analyses. IL-8 level in the medium was determined by enzyme-linked immunosorbent assay. NF-κB activation was assessed by electrophoretic mobility shift assay. ROS levels of the cells were detected by confocal microscopic analysis for fluorescent dichlorofluorescein. As a result, H(2)O(2 )induced the activation of NF-κB and expression of IL-8 in AGS cells time-dependently. β-Carotene and lutein showed inhibitory effects on H(2)O(2)-induced increase in intracellular ROS levels, activation of NF-κB, and IL-8 expression in AGS cells. In conclusion, supplementation of carotenoids such as β-carotene and lutein may be beneficial for the treatment of oxidative stress-mediated gastric inflammation.

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

    DOE PAGES

    Cohen, Michael F.; Gurung, Sushma; Birarda, Giovanni; ...

    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

  3. 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.

  4. 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.

  5. 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

  6. Hydrogen peroxide and coffee induce G:C-->T:A transversions in the lacI gene of catalase-defective Escherichia coli.

    PubMed

    Ruiz-Laguna, J; Pueyo, C

    1999-01-01

    The mutagenicity of hydrogen peroxide (H2O2) was compared with that of coffee, a complex mixture which generates H2O2. An Escherichia coli strain defective in catalase activity (katG katE double mutant) and carrying a single copy mucAB (pRW144) plasmid was constructed to enhance the mutagenic response to oxidants. The ability of the mucAB genes to influence the type, frequency and distribution of H2O2-induced mutations was also investigated in isogenic bacteria lacking pRW144. Induced mutational spectra were characterized and compared with that of spontaneous mutagenesis. A total of 444 independent forward mutations affecting the first 210 bp of the lacI gene were identified by DNA sequence analysis. The spontaneous mutation spectrum showed no bias (P = 0.52) for substitutions at G:C base pairs. In contrast, in the H2O2-induced spectrum substitutions occurred preferentially at G:C base pairs (P < 0.0001) with a preponderance of G:C-->T:A transversions (43.4% of H2O2-induced mutants versus 17.3% of spontaneous mutants). These data support the view that 7,8-dihydro-8-oxoguanine is the main premutagenic lesion induced by H2O2 and that catalase-defective bacteria have elevated levels of 8-oxoguanine in chromosome DNA after H2O2 exposure. Coffee produced a similar distribution of mutational events as H2O2 (P > 0.05), suggesting that this compound may be the main cause of the coffee-induced mutagenesis. The presence of plasmid pRW144 did not affect the frequency of H2O2-induced G:C-->T:A transversions, but caused an increase in A:T-->T:A transversions and a decrease in -1 base frameshifts. Although the frequencies of G:C-->T:A transversions were similar in all three induced spectra (H2O2 and coffee +/- pRW144), differences were observed in location of mutations throughout the target gene.

  7. Efficient repair of hydrogen peroxide-induced DNA damage by Escherichia coli requires SOS induction of RecA and RuvA proteins.

    PubMed

    Konola, J T; Sargent, K E; Gow, J B

    2000-04-28

    The survival of Escherichia coli following treatment with a low dose (1-3 mM) of hydrogen peroxide (H(2)O(2)) that causes extensive mode-one killing of DNA repair mutants is stimulated by the induction of the SOS regulon. Results for various mutants indicate that induction of recA and RecA protein-mediated recombination are critical factors contributing to the repair of H(2)O(2)-induced oxidative DNA damage. However, because DNA damage activates RecA protein's coprotease activity essential to cleavage of LexA repressor protein and derepression of all SOS genes, it is unclear to what extent induction of RecA protein stimulates this repair. To make this determination, we examined mode-one killing of DeltarecA cells carrying plasmid-borne recA (P(tac)-recA(+)) and constitutively expressing a fully induced level of wild-type RecA protein when SOS genes other than recA are non-inducible in a lexA3 (Ind(-)) genetic background or inducible in a lexA(+) background. At a H(2)O(2) dose resulting in maximal killing, DeltarecA lexA3 (Ind(-)) cells with P(tac)-recA(+) show 40-fold greater survival than lexA3 (Ind(-)) cells with chromosomal recA having a low, non-induced level of RecA protein. However, they still show 10- to 15-fold lower survival than wild-type cells and DeltarecA lexA(+) cells with P(tac)-recA(+). To determine if the inducible RuvA protein stimulates survival, we examined a ruvA60 mutant that is defective for the repair of UV-induced DNA damage. This mutant also shows 10- to 15-fold lower survival than wild-type cells. We conclude that while induction of RecA protein has a pronounced stimulatory effect on the recombinational repair of H(2)O(2)-induced oxidative DNA damage, the induction of other SOS proteins such as RuvA is essential for wild-type repair.

  8. 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

    2015-06-05

    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.

  9. Involvement of hydrogen peroxide in the regulation of senescence in pear.

    PubMed

    Brennan, T; Frenkel, C

    1977-03-01

    Endogenous peroxide levels in pear fruit (Pyrus communis) were measured using a titanium assay method, and were found to increase during senescence in both Bartlett and Bosc varieties. Application of glycolic acid or xanthine, serving as substrates for the formation of H(2)O(2), increased the peroxide content of the tissue and accelerated the onset of ripening, as measured by increased softening and ethylene evolution. Application of ethylene also induced increased peroxide levels. Ripening processes were similarly promoted when peroxides were conserved by inhibiting the activity of catalase with hydroxylamine or potassium cyanide. By comparison, the inhibition of glycolate oxidase with alphahydroxy-2-pyridinemethanesulfonic acid decreased the peroxide content of the tissue and delayed the onset of ripening. These results indicate that the onset of ripening correlates with the peroxide content of fruit tissues as occurring under normal conditions or as influenced by the treatments. Hydrogen peroxide may be involved in oxidative processes required in the initiation and the promotion of ripening.

  10. 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.

  11. Hydrogen peroxide mediated transvaginal drug delivery.

    PubMed

    Fatakdawala, Hussain; Uhland, Scott A

    2011-05-16

    Simple, safe and effective permeability enhancers are crucial for successful non-invasive drug delivery methods. We seek local permeability augmentation mechanisms for integration into passive or active architectures in order to enable novel therapeutic delivery routes of the target drug while minimizing drug formulation challenges. This study explores the efficacy of hydrogen peroxide (HP) as a permeability enhancer for transmucosal delivery of macromolecules. HP at low concentrations (2–8 mM) is an effective permeability enhancer that is locally metabolized and safe. HP improves drug permeation through mucosa by altering tight junctions (TJ) between cells and oxidizing enzymes that function to degrade the foreign species. Results from trans-epithelial electrical resistance measurements and cell viability assay show reversible disassembly of TJ with minimal cell damage demonstrating the feasibility of HP as a safe permeability enhancer for drug delivery. Permeation studies show that HP treatment of cell cultured vaginal mucosa significantly enhances the permeability to insulin by more than an order of magnitude. This work lays foundation for the development of a drug delivery platform that administers drug doses by enhancing the permeability of local epithelial tissue via a separate HP treatment step.

  12. 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.

  13. 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.

  14. 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

  15. Methanol extracts from Cystoseira tamariscifolia and Cystoseira nodicaulis are able to inhibit cholinesterases and protect a human dopaminergic cell line from hydrogen peroxide-induced cytotoxicity.

    PubMed

    Custódio, Luísa; Silvestre, Laura; Rocha, Maria Isabel; Rodrigues, Maria João; Vizetto-Duarte, Catarina; Pereira, Hugo; Barreira, Luísa; Varela, João

    2016-09-01

    Context Marine macroalgae contain several bioactive molecules that may be developed as functional foods, but information about their neuroprotective potential is scarce. Objective The objective of this study is to determine the in vitro antioxidant and neuroprotective features of marine algae from the southern coast of Portugal and to assess the total content of different types of bioactives. Materials and methods Methanol extracts from 21 macroalgal species from the southern Portugal were evaluated for in vitro antioxidant and acetylcholinesterase (AChE) inhibition. Active extracts were further evaluated for inhibitory activity against butyrylcholinesterase (BuChE) and tyrosinase (TYRO), and for their ability to attenuate hydrogen peroxide (H2O2)-induced toxicity in SH-SY5Y cells. The total contents of different phenolic groups were determined for the most active extracts. Results Cystoseira tamariscifolia (Hudson) Papenfuss (Sargassaceae) had the highest antiradical activity (92%, 1 mg/mL). Cystoseira nodicaulis (Withering) M. Roberts (Sargassaceae) (75%) and Cystoseira humilis Schousboe ex Kützing (Sargassaceae) (70%) had the highest iron-chelating activity at 10 mg/mL. Cystoseira baccata (S.G. Gmelin) P.C. Silva (Sargassaceae) was more active towards copper (66%, 10 mg/mL). Cystoseira tamariscifolia had the highest AChE inhibitory capacity (85%, 10 mg/mL). Cystoseira tamariscifolia and C. nodicaulis were also active against BuChE and TYRO, and were able to protect SH-SY5Y cells against oxidative stress induced by H2O2. Cystoseira tamariscifolia had the highest content of all the groups of phenolics, and was particularly enriched in hydroxycinnamic acids (106 mg CAE/g DW). Discussion and conclusion Results indicate that C. tamariscifolia and C. nodicaulis are important sources of nutraceutical compounds and may be considered functional foods that could improve cognitive functions.

  16. 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.

  17. NADPH oxidase-dependent hydrogen peroxide production, induced by salinity stress, may be involved in the regulation of total calcium in roots of wheat.

    PubMed

    Yang, Yingli; Xu, Shijian; An, Lizhe; Chen, Nianlai

    2007-11-01

    Hydrogen peroxide (H(2)O(2)) is often generated by cells and tissues under environmental stress. In this work, we provide evidence that plasma membrane (PM) NADPH oxidase-dependent H(2)O(2) production might act as an intermediate step in the NaCl-induced elevation of calcium (Ca) in roots of wheat. Remarkable increases in the content of total Ca were observed not only in roots exposed to NaCl but also in roots of seedlings exposed to exogenous H(2)O(2). In roots, H(2)O(2) production increased upon exposure to salt stress. PM vesicles were isolated from roots, and NADPH oxidase activity was determined by measuring superoxide anion (O(2)(-)) production. NADPH oxidase-dependent O(2)(-) production was 11.6nmolmg(-1)proteinmin(-1) in control vesicles, but 19.6nmol after NaCl treatment (24h), indicating that salt stress resulted in the activation of the PM NADPH oxidase. Furthermore, the NaCl-induced increase in total Ca was partially abolished by the addition of 150U/mL catalase (CAT), a H(2)O(2) scavenger, and also by 10microM diphenylane iodonium (DPI), a NADPH oxidase inhibitor. This data suggest that NADPH oxidase-dependent H(2)O(2) production might be involved in the modulation of the Ca content in wheat roots. In conclusion, our results show that salinity stress increases the total Ca content of wheat roots, which is partly due to PM NADPH oxidase-dependent H(2)O(2) generation.

  18. Genome-Wide Analysis of Hydrogen Peroxide-Regulated Gene Expression in Arabidopsis Reveals a High Light-Induced Transcriptional Cluster Involved in Anthocyanin Biosynthesis1[w

    PubMed Central

    Vanderauwera, Sandy; Zimmermann, Philip; Rombauts, Stéphane; Vandenabeele, Steven; Langebartels, Christian; Gruissem, Wilhelm; Inzé, Dirk; Van Breusegem, Frank

    2005-01-01

    In plants, reactive oxygen species and, more particularly, hydrogen peroxide (H2O2) play a dual role as toxic by-products of normal cell metabolism and as regulatory molecules in stress perception and signal transduction. Peroxisomal catalases are an important sink for photorespiratory H2O2. Using ATH1 Affymetrix microarrays, expression profiles were compared between control and catalase-deficient Arabidopsis (Arabidopsis thaliana) plants. Reduced catalase levels already provoked differences in nuclear gene expression under ambient growth conditions, and these effects were amplified by high light exposure in a sun simulator for 3 and 8 h. This genome-wide expression analysis allowed us to reveal the expression characteristics of complete pathways and functional categories during H2O2 stress. In total, 349 transcripts were significantly up-regulated by high light in catalase-deficient plants and 88 were down-regulated. From this data set, H2O2 was inferred to play a key role in the transcriptional up-regulation of small heat shock proteins during high light stress. In addition, several transcription factors and candidate regulatory genes involved in H2O2 transcriptional gene networks were identified. Comparisons with other publicly available transcriptome data sets of abiotically stressed Arabidopsis revealed an important intersection with H2O2-deregulated genes, positioning elevated H2O2 levels as an important signal within abiotic stress-induced gene expression. Finally, analysis of transcriptional changes in a combination of a genetic (catalase deficiency) and an environmental (high light) perturbation identified a transcriptional cluster that was strongly and rapidly induced by high light in control plants, but impaired in catalase-deficient plants. This cluster comprises the complete known anthocyanin regulatory and biosynthetic pathway, together with genes encoding unknown proteins. PMID:16183842

  19. Titrimetric determination of hydrogen peroxide in alkaline solution.

    PubMed

    McCurdy, W H; Bell, H F

    1966-07-01

    Direct titration of hydrogen peroxide in alkaline bromide media has been accomplished with sodium hypochlorite. The relative standard deviation is 0.2%. A photometric end-point is recommended for the determination of 0.10-1.0 mequiv of peroxide. Larger samples are evaluated by use of Bordeaux Red as visual indicator. The hypochlorite procedure compares favourably with iodometry and permanganate in the analysis of commercial peroxides.

  20. THE PRODUCTION OF HYDROGEN PEROXIDE BY HIGH OXYGEN PRESSURES

    PubMed Central

    Gilbert, Daniel L.; Gerschman, Rebeca; Ruhm, K. Barclay; Price, William E.

    1958-01-01

    Hydrogen peroxide is formed in solutions of glutathione exposed to oxygen. This hydrogen peroxide or its precursors will decrease the viscosity of polymers like desoxyribonucleic acid and sodium alginate. Further knowledge of the mechanism of these chemical effects of oxygen might further the understanding of the biological effects of oxygen. This study deals with the rate of solution of oxygen and with the decomposition of hydrogen peroxide in chemical systems exposed to high oxygen pressures. At 6 atmospheres, the absorption coefficient for oxygen into water was about 1 cm./hour and at 143 atmospheres, it was about 2 cm./hour; the difference probably being due to the modus operandi. The addition of cobalt (II), manganese (II), nickel (II), or zinc ions in glutathione (GSH) solutions exposed to high oxygen pressure decreased the net formation of hydrogen peroxide and also the reduced glutathione remaining in the solution. Studies on hydrogen peroxide decomposition indicated that these ions act probably by accelerating the hydrogen perioxide oxidation of glutathione. The chelating agent, ethylenediaminetetraacetic acid disodium salt, inhibited the oxidation of GSH exposed to high oxygen pressure for 14 hours. However, indication that oxidation still occurred, though at a much slower rate, was found in experiments lasting 10 weeks. Thiourea decomposed hydrogen peroxide very rapidly. When GSH solutions were exposed to high oxygen pressure, there was oxidation of the GSH, which became relatively smaller with increasing concentrations of GSH. PMID:13525677

  1. Abscisic acid is a key inducer of hydrogen peroxide production in leaves of maize plants exposed to water stress.

    PubMed

    Hu, Xiuli; Zhang, Aying; Zhang, Jianhua; Jiang, Mingyi

    2006-11-01

    The histochemical and cytochemical localization of water stress-induced H(2)O(2) production in the leaves of ABA-deficient vp5 mutant and wild-type maize (Zea mays L.) plants were examined, using 3,3-diaminobenzidine and CeCl(3) staining, respectively, and the roles of endogenous ABA in the production of H(2)O(2) induced by water stress were assessed. Water stress induced by polyethylene glycol resulted in the accumulation of H(2)O(2) in mesophyll cells, bundle-sheath cells and vascular bundles of wild-type maize leaves, and the accumulation was substantially blocked in the mutant maize leaves exposed to water stress. Pre-treatments with several apoplastic H(2)O(2) manipulators abolished the majority of H(2)O(2) accumulation induced by water stress in the wild-type leaves. The subcellular localization of H(2)O(2) production was demonstrated in the cell walls, xylem vessels, chloroplasts, mitochondria and peroxisomes in the leaves of wild-type maize plants exposed to water stress, and the accumulation of H(2)O(2) induced by water stress in the cell walls and xylem vessels, but not in the chloroplasts, mitochondria and peroxisomes, was arrested in the leaves of the ABA mutant or the ABA biosynthesis inhibitor (tungstate)-pre-treated maize plants. Pre-treatments with the apoplastic H(2)O(2) manipulators also blocked the apoplastic but not the intracellular H(2)O(2) accumulation induced by water stress in the leaves of wild-type plants. These data indicate that under water stress, the apoplast is the major source of H(2)O(2) production and ABA is a key inducer of apoplastic H(2)O(2) production. These data also suggest that H(2)O(2) generated in the apoplast could not diffuse freely into subcellular compartments.

  2. Hydrogen peroxide-induced apoptosis of HL-60 human leukemia cells is mediated by the oxidants hypochlorous acid and chloramines.

    PubMed

    Wagner, Brett A; Britigan, Bradley E; Reszka, Krzysztof J; McCormick, Michael L; Burns, C Patrick

    2002-05-15

    We set out to identify whether HOCl, which is generated from H(2)O(2) /MPO/Cl(-), is a proximal mediator of H(2)O(2) programmed cell death in the HL-60 human leukemia cell. We found that authentic HOCl induces apoptosis in the HL-60 cell. Both the addition of methionine, an HOCl scavenger, and the removal of Cl(-) from the medium to prevent the formation of HOCl inhibited H(2)O(2)-induced apoptosis. HL-60 cells underwent apoptosis when exposed to HOCl in full medium, which gives rise to chloramines by the reaction of HOCl with amine groups, but not by HOCl in the amine-free HBSS, in which HOCl but not chloramines can be detected. Authentic chloramines induced apoptosis in this cell line in a concentration-dependent manner and at concentrations lower than HOCl. Full medium exposed to HOCl for 24 h would support methionine noninhibitable apoptosis, but did not react with 2-nitro-5-thiobenzoic acid (TNB), raising the possibility that the final inducer is a nonoxidant formed from HOCl and chloramines. We conclude that the signal for apoptosis induced by H(2)O(2) in the MPO-containing HL-60 cell involves the reaction of the diffusible oxidant HOCl with amines producing chloramines and a subsequent non-TNB-reactive product.

  3. 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.

  4. [Risks of hydrogen peroxide irrigation in military surgery].

    PubMed

    Saïssy, J M; Guignard, B; Pats, B; Lenoir, B; Rouvier, B

    1994-01-01

    Two cases of severe complications due to injection of hydrogen peroxide under pressure into areas of muscular attrition in war wounds are reported. In both cases the administration of hydrogen peroxide was associated with tachypnoea, with major arterial desaturation and a precordial "mill-wheel" murmur was heard. In one case, these symptoms were followed by hemiplegia caused by paradoxical arterial gas embolism, and in the other case by a pulmonary oedema confirmed by computerized tomography. Both patients recovered under hyperbaric oxygen therapy. The release of gaseous oxygen under the effect of tissue catalase and the membrane peroxydasic activity of hydrogen peroxide initiate such complications. The injection of hydrogen peroxide under pressure into a closed or partially closed cavity should therefore be strictly prohibited.

  5. The Protective Effect of Eupatilin against Hydrogen Peroxide-Induced Injury Involving 5-Lipoxygenase in Feline Esophageal Epithelial Cells

    PubMed Central

    Lim, Jae Chun; Park, Sun Young; Nam, Yoonjin; Nguyen, Thanh Thao

    2012-01-01

    In this study, we focused to identify whether eupatilin (5,7-dihydroxy-3',4',6-trimethoxyflavone), an extract from Artemisia argyi folium, prevents H2O2-induced injury of cultured feline esophageal epithelial cells. Cell viability was measured by the conventional MTT reduction assay. Western blot analysis was performed to investigate the expression of 5-lipoxygenase by H2O2 treatment in the absence and presence of inhibitors. When cells were exposed to 600 µM H2O2 for 24 hours, cell viability was decreased to 40%. However, when cells were pretreated with 25~150 µM eupatilin for 12 hours, viability was significantly restored in a concentration-dependent manner. H2O2-treated cells were shown to express 5-lipoxygenase, whereas the cells pretreated with eupatilin exhibited reduction in the expression of 5-lipoxygenase. The H2O2-induced increase of 5-lipoxygenase expression was prevented by SB202190, SP600125, or NAC. We further demonstrated that the level of leukotriene B4 (LTB4) was also reduced by eupatilin, SB202190, SP600125, NAC, or nordihydroguaiaretic acid (a lipoxygenase inhibitor) pretreatment. H2O2 induced the activation of p38MAPK and JNK, this activation was inhibited by eupatilin. These results indicate that eupatilin may reduce H2O2-induced cytotoxicity, and 5-lipoxygenase expression and LTB4 production by controlling the p38 MAPK and JNK signaling pathways through antioxidative action in feline esophageal epithelial cells. PMID:23118554

  6. The cytoprotective effect of Rumex Aquaticus Herba extract against hydrogen peroxide-induced oxidative stress in AGS cells.

    PubMed

    Cho, Eun Jeong; Um, Seung In; Han, Jeong Hoon; Kim, Byeonghee; Han, Sang Beom; Jeong, Ji Hoon; Kim, Hak Rim; Kim, Inkyeom; Whang, Wan Kyun; Lee, Eunhwa; Sohn, Uy Dong

    2016-12-01

    The Rumex Aquaticus Herba extract containing quercetin-3-β-D-glucuronopyranoside (ECQ) has been reported to exhibit various pharmacological activities, including anti-inflammatory and anti-oxidative effects. This plant has been traditionally used for the treatment of diarrhea, disinfestation, edema and jaundice, and as an antipyretic drug. The aim of the present study was to investigate the ability of ECQ to protect against oxidative damage and to determine its signaling mechanism in AGS cells. The protein expressions of heme oxygenase-1 (HO-1) and nuclear factor-erythroid 2 related factor 2 (Nrf2) were measured by Western blots. Cell viability was measured by MTT assay. Intracellular reactive oxygen species (ROS) levels were measured using 2',7'-dichlorofluorescein diacetate. Glutathione peroxidase levels were measured using kits. The protein expressions of HO-1 and its upstream mediator, Nrf2, increased after ECQ treatment. The HO-1 inhibitor, ZnPP, repressed the protective effect of ECQ on H2O2-induced cell damage. We found that LY294002, a specific PI3 K/Akt inhibitor, suppressed ECQ-induced HO-1 expression. ECQ significantly attenuated H2O2-induced cytotoxicity and ROS generation. Also, ECQ enhanced the antioxidant enzyme activities of glutathione peroxidase. These results suggest that ECQ exerts a cytoprotective effect against H2O2-induced oxidative stress by upregulation of Nrf2/HO-1 via the PI3 K/Akt pathway.

  7. 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.

  8. 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.

  9. In Vitro Evaluation of the Risk of Inducing Bacterial Resistance to Disinfection Treatment with Photolysis of Hydrogen Peroxide

    PubMed Central

    Ikai, Hiroyo; Odashima, Yu; Kanno, Taro; Nakamura, Keisuke; Shirato, Midori; Sasaki, Keiichi; Niwano, Yoshimi

    2013-01-01

    The purpose of the present study was to evaluate the risk of inducing bacterial resistance to disinfection treatment with photolysis of H2O2 and comparing this with existing antibacterial agents. We tested seven antibacterial agents, including amoxicillin, cefepime hydrochloride, erythromycin, ofloxacin, clindamycin hydrochloride, ciprofloxacin hydrochloride, and minocycline hydrochloride, as positive controls for validation of the assay protocol. For all of the agents tested, at least one of the four bacterial species (Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Streptococcus salivarius) was resistant to these agents by repeated exposure to subinhibitory concentrations of the agents up to 10 times. In contrast, antibacterial activity against any of the bacterial species tested (S. aureus, E. faecalis, E. coli, S. salivarius, Pseudomonas aeruginosa, Streptococcus mutans, and Aggregatibacter actinomycetemcomitans) was not affected by repeated exposure to the disinfection treatment up to 40 times. This finding suggested that the risk of inducing bacterial resistance by disinfection treatment was low. The active ingredient of this disinfection treatment is hydroxyl radicals generated by photolysis of H2O2. Therefore, hydroxyl radicals interact with several cell structures and different metabolic pathways in microbial cells, probably resulting in a lack of development of bacterial resistance. In conclusion, disinfection treatment with photolysis of H2O2 appears to be a potential alternative for existing antimicrobial agents in terms of a low risk of inducing bacterial resistance. PMID:24282582

  10. 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.

  11. In vitro evaluation of the risk of inducing bacterial resistance to disinfection treatment with photolysis of hydrogen peroxide.

    PubMed

    Ikai, Hiroyo; Odashima, Yu; Kanno, Taro; Nakamura, Keisuke; Shirato, Midori; Sasaki, Keiichi; Niwano, Yoshimi

    2013-01-01

    The purpose of the present study was to evaluate the risk of inducing bacterial resistance to disinfection treatment with photolysis of H2O2 and comparing this with existing antibacterial agents. We tested seven antibacterial agents, including amoxicillin, cefepime hydrochloride, erythromycin, ofloxacin, clindamycin hydrochloride, ciprofloxacin hydrochloride, and minocycline hydrochloride, as positive controls for validation of the assay protocol. For all of the agents tested, at least one of the four bacterial species (Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Streptococcus salivarius) was resistant to these agents by repeated exposure to subinhibitory concentrations of the agents up to 10 times. In contrast, antibacterial activity against any of the bacterial species tested (S. aureus, E. faecalis, E. coli, S. salivarius, Pseudomonas aeruginosa, Streptococcus mutans, and Aggregatibacter actinomycetemcomitans) was not affected by repeated exposure to the disinfection treatment up to 40 times. This finding suggested that the risk of inducing bacterial resistance by disinfection treatment was low. The active ingredient of this disinfection treatment is hydroxyl radicals generated by photolysis of H2O2. Therefore, hydroxyl radicals interact with several cell structures and different metabolic pathways in microbial cells, probably resulting in a lack of development of bacterial resistance. In conclusion, disinfection treatment with photolysis of H2O2 appears to be a potential alternative for existing antimicrobial agents in terms of a low risk of inducing bacterial resistance.

  12. 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.

  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

    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.

  15. Polyphenols suppress hydrogen peroxide-induced oxidative stress in human bone-marrow derived mesenchymal stem cells.

    PubMed

    Yagi, Haruyo; Tan, Jian; Tuan, Rocky S

    2013-05-01

    Human mesenchymal stem cells (hMSCs) are considered a highly promising candidate cell type for cell-based tissue engineering and regeneration because of their self-renewal and multi-lineage differentiation characteristics. Increased levels of reactive oxygen/nitrogen species (ROS/RNS) are associated with tissue injury and inflammation, impact a number of cellular processes, including cell adhesion, migration, and proliferation, and have been linked to cellular senescence in MSCs, potentially compromising their activities. Naturally occurring polyphenolic compounds (polyphenols), epigallocatechin-3-gallate (EGCG), and curcumin, block ROS/RNS and are potent inflammation-modulating agents. However, their potential protective effects against oxidative stress in hMSCs have not been examined. In this study, we carried out a systematic analysis of the effects of polyphenols on hMSCs in their response to oxidative stress in the form of treatment with H(2)O(2) and S-nitroso-N-acetylpenicillamine (SNAP), respectively. Parameters measured included colony forming activity, apoptosis, and the levels of antioxidant enzymes and free reactive species. We found that polyphenols reversed H(2)O(2) -induced loss of colony forming activity in hMSCs. In a dose-dependent manner, polyphenols inhibited increased levels of ROS and NO, produced by H(2)O(2) or SNAP, respectively, in MSCs. Notably, polyphenols rapidly and almost completely blocked H(2)O(2) -induced ROS in the absence of significant direct effect on H(2)O(2) itself. Polyphenols also protected the antioxidant enzymes and reduced apoptotic cell death caused by H(2)O(2) exposure. Taken together, these findings demonstrate that EGCG and curcumin are capable of suppressing inducible oxidative stress in hMSCs, and suggest a possible new approach to maintain MSC viability and potency for clinical application.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. Hydrogen peroxide induced phenylpropanoids pathway eliciting a defensive response in plants micropropagated in Temporary Immersion Bioreactors (TIBs).

    PubMed

    Arencibia, Ariel D; Bernal, Aydiloide; Zayas, Carlos; Carmona, Elva; Cordero, Cecilia; González, Gloria; García, Rolando; Santana, Ignacio

    2012-10-01

    The relation between the oxidative burst and phenylpropanoid pathways has been studied using the sugarcane cultivar C86-56, which does not release phenolics in agar-base micropropagation systems. In stationary liquid culture, a significant production of phenolic compounds and plant survival were determined in sugarcane plants treated with 5mM H(2)O(2). The spectrophotometer determinations and the gene expression analysis corroborated that releasing of phenolics and soluble θ-quinones was induced during the first 24h of treatment. In comparison with the control treatments, sugarcane plants treated with H(2)O(2) demonstrated differences in the micropropagation-related variables when multiplied in Temporary Immersion Bioreactors (TIBs) supplemented with polyethyleneglycol (PEG 20%). Expression of selected genes related to photosynthesis, ethylene, auxins, oxidative burst, and defense pathways were confirmed during the entire PEG 20% stress in the plants coming from the 5mM H(2)O(2) treatment; whereas, much more heterogeneous expression patterns were evidenced in plants stressed with PEG but not previously treated with H(2)O(2). RT-PCR expression analysis supports the hypothesis that while H(2)O(2) induces the oxidative burst, the phenylpropanoids pathways elicit and maintain the defensive response mechanism in micropropagated sugarcane plants.

  1. 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%).

  2. Extract from Armoracia rusticana and its flavonoid components protect human lymphocytes against oxidative damage induced by hydrogen peroxide.

    PubMed

    Gafrikova, Michala; Galova, Eliska; Sevcovicova, Andrea; Imreova, Petronela; Mucaji, Pavel; Miadokova, Eva

    2014-03-14

    DNA damage prevention is an important mechanism involved in cancer prevention by dietary compounds. Armoracia rusticana is cultivated mainly for its roots that are used in the human diet as a pungent spice. The roots represent rich sources of biologically active phytocompounds, which are beneficial for humans. In this study we investigated the modulation of H₂O₂ genotoxicity using the A. rusticana root aqueous extract (AE) and two flavonoids (kaempferol or quercetin). Human lymphocytes pre-treated with AE, kaempferol and quercetin were challenged with H₂O₂ and the DNA damage was assessed by the comet assay. At first we assessed a non-genotoxic concentration of AE and flavonoids, respectively. In lymphocytes challenged with H₂O₂ we proved that the 0.0025 mg·mL⁻¹ concentration of AE protected human DNA. It significantly reduced H₂O₂-induced oxidative damage (from 78% to 35.75%). Similarly, a non-genotoxic concentration of kaempferol (5 μg·mL⁻¹) significantly diminished oxidative DNA damage (from 83.3% to 19.4%), and the same concentration of quercetin also reduced the genotoxic effect of H₂O₂ (from 83.3% to 16.2%). We conclude that AE, kaempferol and quercetin probably act as antimutagens. The molecular mechanisms underlying their antimutagenic activity might be explained by their antioxidant properties.

  3. 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

  4. 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.

  5. [Determination of hydrogen peroxide in rainwater by fluorometry].

    PubMed

    Fang, Yan-Fen; Huang, Ying-Ping; Luo, Guang-Fu; Li, Rui-Ping

    2008-04-01

    The present paper introduces a new method using spectrofluorimetric analysis to determine the concentration of hydrogen peroxide in rainwater. In this method, an oxidation reaction is conducted between o-phenylenediamine (OPDA) and hydrogen peroxide in the buffer medium of NaAc-HAc at pH 4. 48 to form a new product 2,3-diaminophenazine (DAPN). Then the fluorescence intensity of DAPN is measured and 426 and 554 nm are chosen as the excitation and emission wavelengths. Therefore, with the foreknown concentration of input hydrogen peroxide, a series of fluorescence intensities of DAPN are acquired according to a series of different concentration of hydrogen peroxide as input, greatly improving the selectivity and sensibility of the system. A relationship between the input concentration of hydrogen peroxide and the fluorescence intensity of DAPN is then obtained using a linear regression. Results show that fluorescence intensity of DAPN is in proportion to the increase in the concentration of hydrogen peroxide in the range of 9.0 x 10(-7) -3.56 x 10(-5) mol x L(-1) almost linearly. The linear equation is F = 1.15c (micromol x L(-1))+398.6 (r = 0.999 1) and the detection limit is 2.7 x10(-7) mol x L(-1) (n = 11). The relative standard deviation of 11 parallel measurements with the concentration of H2O2 at 7.5 x 10(-6) and 3.0 x 10(-5) mol x L(-1), is 2.2 and 1.0%, respectively. Results from DPD method was used to verify this method. The interference of foreign iron was studied. Compared to the traditional methods, this binary system has a simplified operation and high sensitivity. The proposed method has been successfully applied to determine the concentration of hydrogen peroxide in rainwater.

  6. [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.

  7. Hydrogen peroxide overload increases adriamycin-induced apoptosis of SaOS(2)FM, a manganese superoxide dismutase-overexpressing human osteosarcoma cell line.

    PubMed

    Wang, Yadi; Kuroda, Masahiro; Gao, Xian-Shu; Asaumi, Jun-Ichi; Shibuya, Kohichi; Kawasaki, Shoji; Akaki, Shiro; St Clair, Daret; Hiraki, Yoshio; Kanazawa, Susumu

    2005-05-01

    We previously developed a new microscopic observation system that enables time-lapse quantitative analysis of apoptosis and necrosis. With this system we quantitatively analyzed adriamycin (ADR)-induced cell death using manganese superoxide dismutase (MnSOD)- and wild-type p53-gene transfectants on SaOS(2), a p53-deficient human osteosarcoma cell line. A highly MnSOD-overexpressing cell line, SaOS(2)FM(H), acquired ADR-tolerance compared to the parent cell line SaOS(2). The ADR-tolerance of SaOS(2)FM(H) diminished by L-buthionine-[S,R]-sulfoximine (BSO), which did not change ADR-sensitivity of SaOS(2), to the similar ADR-sensitivity of SaOS(2). A wild-type p53-expressing cell line, SaOS(2)wtp53, significantly increased in ADR-sensitivity compared to SaOS(2). This ADR-sensitivity of SaOS(2)wtp53 was enhanced by BSO. When isosorbide 5-mononitrate was combined with BSO, isosorbide 5-mononitrate increased ADR sensitivity of a moderately MnSOD-overexpressing cell line, SaOS(2)FM(L), decreased that of SaOS(2) FM(H), and did not change those of SaOS(2) and SaOS(2)wtp53 compared to BSO alone. Time-lapse microscopic observations during ADR treatment for 24 h indicated that the most cells of each cell line underwent apoptosis, and a few cells (less than 11%) died by necrosis. When cells were treated with iso-concentration of ADR, apoptosis of SaOS(2)FM(H) was less than that of SaOS(2). BSO, which did not change ADR-sensitivity of SaOS(2), increased appearance rate of ADR-induced apoptosis, but not necrosis of MnSOD-overexpressing cell lines. When iso-survival dose of ADR, which reduced surviving fraction to 0.01, was given for each cell line, no difference was observed in appearance of either apoptosis or necrosis between SaOS(2) and MnSOD-overexpressing cell lines. On the other hands, appearance of both apoptosis and the following secondary necrosis of SaOS(2) wtp53 was significantly accelerated compared to those of SaOS(2). These findings indicate that hydrogen peroxide

  8. Antioxidant activity of wine pigments derived from anthocyanins: hydrogen transfer reactions to the dpph radical and inhibition of the heme-induced peroxidation of linoleic acid.

    PubMed

    Goupy, Pascale; Bautista-Ortin, Ana-Belen; Fulcrand, Helene; Dangles, Olivier

    2009-07-08

    The consumption of red wine can provide substantial concentrations of antioxidant polyphenols, in particular grape anthocyanins (e.g., malvidin-3-O-beta-d-glucoside (1)) and specific red wine pigments formed by reaction between anthocyanins and other wine components such as catechin (3), ethanol, and hydroxycinnamic acids. In this work, the antioxidant properties of red wine pigments (RWPs) are evaluated by the DPPH assay and by inhibition of the heme-induced peroxidation of linoleic acid in acidic conditions (a model of antioxidant action in the gastric compartment). RWPs having a 1 and 3 moieties linked via a CH(3)-CH bridge appear more potent than the pigment with a direct 1-3 linkage. Pyranoanthocyanins derived from 1 reduce more DPPH radicals than 1 irrespective of the substitution of their additional aromatic ring. Pyranoanthocyanins are also efficient inhibitors of the heme-induced lipid peroxidation, although the highly hydrophilic pigment derived from pyruvic acid appears less active.

  9. Effect of amino acids on X-ray-induced hydrogen peroxide and hydroxyl radical formation in water and 8-oxoguanine in DNA.

    PubMed

    Shtarkman, I N; Gudkov, S V; Chernikov, A V; Bruskov, V I

    2008-04-01

    Generation of hydrogen peroxide and hydroxyl radicals in L-amino acid solutions in phosphate buffer, pH 7.4, under X-ray irradiation was determined by enhanced chemiluminescence in the luminol-p-iodophenol-peroxidase system and using the fluorescent probe coumarin-3-carboxylic acid, respectively. Amino acids are divided into three groups according to their effect on the hydrogen peroxide formation under irradiation: those decreasing yield of H2O2, having no effect, and increasing its yield. All studied amino acids at 1 mM concentration decrease the yield of hydroxyl radicals in solution under X-ray irradiation. However, the highest effect is observed in the order: Cys > His > Phe = Met = Trp > Tyr. At Cys, Tyr, and His concentrations close to physiological, the yield of hydroxyl radicals decreases significantly. Immunoenzyme analysis using monoclonal antibodies to 8-oxoguanine (8-oxo-7,8-dihydroguanine) was applied to study the effect of amino acids with the most pronounced antioxidant properties (Cys, Met, Tyr, Trp, Phe, His, Lys, Arg, Pro) on 8-oxoguanine formation in vitro under X-ray irradiation. It is shown that amino acids decrease the content of 8-oxoguanine in DNA. These amino acids within DNA-binding proteins may protect intracellular DNA against oxidative damage caused by formation of reactive oxygen species in conditions of moderate oxidative stress.

  10. Changes in tetrahydrobiopterin levels in endothelial cells and adult cardiomyocytes induced by LPS and hydrogen peroxide--a role for GFRP?

    PubMed

    Kalivendi, Shasi; Hatakeyama, Kazuyuki; Whitsett, Jennifer; Konorev, Eugene; Kalyanaraman, B; Vásquez-Vivar, Jeannette

    2005-02-15

    Alterations in tetrahydrobiopterin (BH4) levels have significant consequences in vascular pathophysiology. However, the mechanisms regulating BH4 remain poorly understood. The activity of GTP cyclohydrolase I (GTPCH-I), the first enzyme in BH4 biosynthesis, is controlled by protein levels, posttranslational modifications and interaction with GTPCH-I feedback regulatory protein (GFRP). This work examined the correlation between GTPCH-I protein levels and activity and changes in BH4 in human endothelial cells (HAECs) and adult rat cardiomyocytes (ARCM). Changes in BH4 were stimulated with LPS in HAECs and ARCM, and with hydrogen peroxide in HAECs only. Biopterin production by HAECs and ARCM were attained with concentrations of LPS >1 microg/ml and responses were nonlinear with respect to LPS concentrations. Western blot analysis demonstrated that induction of biopterin synthesis in HAECs and ARCM by LPS does not entail augmentation of constitutive GTPCH-I protein levels. However, LPS diminished GFRP mRNA, suggesting that disruption of GTPCH-I:GFRP complex enhances de novo biopterin synthesis. Conversely, treatment with hydrogen peroxide increased GTPCH-I and GFRP mRNA levels in HAECs while depleting BH4 and GSH, which was counteracted by catalase. This indicates that GFRP may override increases in GTPCH-I protein inhibiting enzyme activity. This conclusion is further supported by depletion of biopterin in cells transiently transfected with GFRP. Thus, allosteric regulation of GTPCH-I activity in the cardiovascular system maybe an important mechanism regulating BH4 levels through GFRP signaling.

  11. Direct synthesis of hydrogen peroxide from plasma-water interactions

    NASA Astrophysics Data System (ADS)

    Liu, Jiandi; He, Bangbang; Chen, Qiang; Li, Junshuai; Xiong, Qing; Yue, Guanghui; Zhang, Xianhui; Yang, Size; Liu, Hai; Liu, Qing Huo

    2016-12-01

    Hydrogen peroxide (H2O2) is usually considered to be an important reagent in green chemistry since water is the only by-product in H2O2 involved oxidation reactions. Early studies show that direct synthesis of H2O2 by plasma-water interactions is possible, while the factors affecting the H2O2 production in this method remain unclear. Herein, we present a study on the H2O2 synthesis by atmospheric pressure plasma-water interactions. The results indicate that the most important factors for the H2O2 production are the processes taking place at the plasma-water interface, including sputtering, electric field induced hydrated ion emission, and evaporation. The H2O2 production rate reaches ~1200 μmol/h when the liquid cathode is purified water or an aqueous solution of NaCl with an initial conductivity of 10500 μS cm‑1.

  12. Direct synthesis of hydrogen peroxide from plasma-water interactions.

    PubMed

    Liu, Jiandi; He, Bangbang; Chen, Qiang; Li, Junshuai; Xiong, Qing; Yue, Guanghui; Zhang, Xianhui; Yang, Size; Liu, Hai; Liu, Qing Huo

    2016-12-05

    Hydrogen peroxide (H2O2) is usually considered to be an important reagent in green chemistry since water is the only by-product in H2O2 involved oxidation reactions. Early studies show that direct synthesis of H2O2 by plasma-water interactions is possible, while the factors affecting the H2O2 production in this method remain unclear. Herein, we present a study on the H2O2 synthesis by atmospheric pressure plasma-water interactions. The results indicate that the most important factors for the H2O2 production are the processes taking place at the plasma-water interface, including sputtering, electric field induced hydrated ion emission, and evaporation. The H2O2 production rate reaches ~1200 μmol/h when the liquid cathode is purified water or an aqueous solution of NaCl with an initial conductivity of 10500 μS cm(-1).

  13. 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

  14. 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...

  15. 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...

  16. 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.

  17. Millimeter and sub-millimeter wave detection of hydrogen peroxide

    NASA Astrophysics Data System (ADS)

    Kolbe, W. F.; Leskovar, B.

    1987-08-01

    The measurement of small concentrations of hydrogen peroxide through the detection of rotational transitions in the millimeter and sub-millimeter wave regions is discussed. Calculated transition frequencies and absorption coefficients of H2O2 for frequencies up to 2000 GHz are presented. The reliability of the calculated values is illustrated by measurements of the linewidths and absorption coefficients of transitions in the 140 GHz range. Finally, methods for the detection of trace quantities of the peroxide molecule are briefly described.

  18. A MEMS methanol reformer heated by decomposition of hydrogen peroxide.

    PubMed

    Kim, Taegyu; Hwang, Jin Soo; Kwon, Sejin

    2007-07-01

    This paper presents the design, fabrication and evaluation of a micro methanol reformer complete with a heat source. The micro system consists of the steam reforming reactor of methanol, the catalytic decomposition reactor of hydrogen peroxide, and a heat exchanger between the two reactors. In the present study, catalytic decomposition of hydrogen peroxide is used as a process to supply heat to the reforming reactor. The decomposition process of hydrogen peroxide produces water vapor and oxygen as a product that can be used efficiently to operate the reformer/PEMFC system. Cu/ZnO was selected as a catalyst for methanol steam reforming and Pt for the decomposition of hydrogen peroxide. Incipient wetness method was used to load catalysts on a porous support. Catalyst loaded supports were inserted in the cavity made on the glass wafer. The performance of the methanol steam reforming system was measured at various test conditions and the optimum operation condition was sought. At the optimum condition, the hydrogen selectivity was 86.4% and the thermal efficiency was 44.8%. The product gas included 74.1% H(2), 24.5% CO(2) and 1.4% CO and the total volume production rate was 23.5 ml min(-1). This amount of hydrogen can produce 1.5 W of power on a typical PEMFC.

  19. 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.

  20. Selective electrochemical generation of hydrogen peroxide from water oxidation

    DOE PAGES

    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

  1. Simulated afterburner performance with hydrogen peroxide injection for thrust augmentation

    NASA Technical Reports Server (NTRS)

    Metzler, Allen J; Grobman, Jack S

    1956-01-01

    Combustion performance of three afterburner configurations was evaluated at simulated altitude flight conditions with liquid augmentation to the primary combustor. Afterburner combustion efficiency and stability were better with injection of high-strength hydrogen peroxide than with no injection or with water injection. Improvements were observed in afterburner configurations with and without flameholders and in a short-length afterburner. At a peroxide-air ratio of 0.3, combustion was stable and 85 to 90 percent efficient in all configurations tested. Calculated augmented net-thrust ratios for peroxide injection with afterburning were approximately 60 percent greater than those for water injection.

  2. Catalytic wet hydrogen peroxide oxidation of a petrochemical wastewater.

    PubMed

    Pariente, M I; Melero, J A; Martínez, F; Botas, J A; Gallego, A I

    2010-01-01

    Continuous Catalytic Wet Hydrogen Peroxide Oxidation (CWHPO) for the treatment of a petrochemical industry wastewater has been studied on a pilot plant scale process. The installation, based on a catalytic fixed bed reactor (FBR) coupled with a stirred tank reactor (STR), shows an interesting alternative for the intensification of a continuous CWHPO treatment. Agglomerated SBA-15 silica-supported iron oxide (Fe(2)O(3)/SBA-15) was used as Fenton-like catalyst. Several variables such as the temperature and hydrogen peroxide concentration, as well as the capacity of the pilot plant for the treatment of inlet polluted streams with different dilution degrees were studied. Remarkable results in terms of TOC reduction and increased biodegradability were achieved using 160 degrees C and moderate hydrogen peroxide initial concentration. Additionally, a good stability of the catalyst was evidenced for 8 hours of treatment with low iron leaching (less than 1 mg/L) under the best operating conditions.

  3. 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.

  4. 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.

  5. 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.

  6. Insulin Induces Relaxation and Decreases Hydrogen Peroxide-Induced Vasoconstriction in Human Placental Vascular Bed in a Mechanism Mediated by Calcium-Activated Potassium Channels and L-Arginine/Nitric Oxide Pathways

    PubMed Central

    Cabrera, Lissette; Saavedra, Andrea; Rojas, Susana; Cid, Marcela; Valenzuela, Cristina; Gallegos, David; Careaga, Pamela; Basualto, Emerita; Haensgen, Astrid; Peña, Eduardo; Rivas, Coralia; Vera, Juan Carlos; Gallardo, Victoria; Zúñiga, Leandro; Escudero, Carlos; Sobrevia, Luis; Wareing, Mark; González, Marcelo

    2016-01-01

    HIGHLIGHTS Short-term incubation with insulin increases the L-arginine transport in HUVECs.Short-term incubation with insulin increases the NO synthesis in HUVECs.Insulin induces relaxation in human placental vascular bed.Insulin attenuates the constriction induced by hydrogen peroxide in human placenta.The relaxation induced by insulin is dependent on BKCa channels activity in human placenta. Insulin induces relaxation in umbilical veins, increasing the expression of human amino acid transporter 1 (hCAT-1) and nitric oxide synthesis (NO) in human umbilical vein endothelial cells (HUVECs). Short-term effects of insulin on vasculature have been reported in healthy subjects and cell cultures; however, its mechanisms remain unknown. The aim of this study was to characterize the effect of acute incubation with insulin on the regulation of vascular tone of placental vasculature. HUVECs and chorionic vein rings were isolated from normal pregnancies. The effect of insulin on NO synthesis, L-arginine transport, and hCAT-1 abundance was measured in HUVECs. Isometric tension induced by U46619 (thromboxane A2 analog) or hydrogen peroxide (H2O2) were measured in vessels previously incubated 30 min with insulin and/or the following pharmacological inhibitors: tetraethylammonium (KCa channels), iberiotoxin (BKCa channels), genistein (tyrosine kinases), and wortmannin (phosphatidylinositol 3-kinase). Insulin increases L-arginine transport and NO synthesis in HUVECs. In the placenta, this hormone caused relaxation of the chorionic vein, and reduced perfusion pressure in placental cotyledons. In vessels pre-incubated with insulin, the constriction evoked by H2O2 and U46619 was attenuated and the effect on H2O2-induced constriction was blocked with tetraethylammonium and iberiotoxin, but not with genistein, or wortmannin. Insulin rapidly dilates the placental vasculature through a mechanism involving activity of BKCa channels and L-arginine/NO pathway in endothelial cells. This

  7. Effect of carbamide peroxide and hydrogen peroxide on the surface morphology and zinc oxide levels of IRM fillings.

    PubMed

    Rostein, I; Cohenca, N; Mor, C; Moshonov, J; Stabholz, A

    1995-12-01

    The effect of 10% carbamide peroxide or 10% hydrogen peroxide on the surface morphology and zinc oxide levels of IRM fillings was tested. Ninety IRM samples were treated with either 10% carbamide peroxide, 10% hydrogen peroxide or phosphate buffer which served as control. Treatment consisted of placing the samples in a dry incubator at 37 degrees C for 1, 3 or 7 days. At each time point, the samples were removed from the test solutions, dried and prepared for surface scanning electron microscopy and energy dispersive spectrometric analysis. After 3 days, 10% carbamide peroxide significantly reduced the zinc oxide levels as compared to the 10% hydrogen peroxide group (<0.01) and the controls (p<0.01). 10% hydrogen peroxide reduced the zinc oxide levels similarly to the control. No significant changes in the zinc oxide levels were found between 3 and 7 days in any of the groups tested. Microscopy examination of the carbamide peroxide group revealed granular surface with well defined crystalline areas. In the hydrogen peroxide group, numerous cracks with multiple sun burst-like areas were found. At the macroscopic level, the samples of this group appeared cracked and more swollen, as compared to controls and samples treated with carbamide peroxide. In conclusion, both 10% carbamide peroxide and 10% hydrogen peroxide altered the surface morphology and the zinc oxide levels of IRM fillings, but their modes of action differed.

  8. Hispidin produced from Phellinus linteus protects pancreatic beta-cells from damage by hydrogen peroxide.

    PubMed

    Jang, Jae Soon; Lee, Jong Seok; Lee, Jung Hyun; Kwon, Duck Soo; Lee, Keun Eok; Lee, Shin Young; Hong, Eock Kee

    2010-06-01

    Phellinus linteus, which is a traditional medicinal mushroom used in Asian countries for the treatment of various diseases, has attracted a lot of attention due to its antioxidant, anti-inflammatory, anti-mutagenicity, and cell-mediated immunity properties in addition to its ability to inhibit tumor growth and metastasis. However, the antidiabetic efficacy of P. linteus has not yet been examined. In this study, hispidin from P. linteus exhibited quenching effects against DPPH radicals, superoxide radicals, and hydrogen peroxide in a dose-dependent manner. Intracellular reactive oxygen species scavenging activity of hispidin was approximately 55% at a concentration of 30 microM. In addition, hispidin was shown to inhibit hydrogen peroxide-induced apoptosis and increased insulin secretion in hydrogen peroxide-treated cells. These combined results indicate that hispidin may act as an antidiabetic and that this property occurs through preventing beta-cells from the toxic action of reactive oxygen species in diabetes.

  9. Hydrogen Peroxide Pretreatment Mitigates Cadmium-Induced Oxidative Stress in Brassica napus L.: An Intrinsic Study on Antioxidant Defense and Glyoxalase Systems

    PubMed Central

    Hasanuzzaman, Mirza; Nahar, Kamrun; Gill, Sarvajeet S.; Alharby, Hesham F.; Razafindrabe, Bam H. N.; Fujita, Masayuki

    2017-01-01

    Cadmium (Cd) is considered as one of the most toxic metals for plant growth and development. In the present study, we investigated the role of externally applied hydrogen peroxide (H2O2) in regulating the antioxidant defense and glyoxalase systems in conferring Cd-induced oxidative stress tolerance in rapeseed (Brassica napus L.). Seedlings were pretreated with 50 μM H2O2 for 24 h. These pretreated seedlings as well as non-pretreated seedlings were grown for another 48 h at two concentrations of CdCl2 (0.5 and 1.0 mM). Both the levels of Cd increased MDA and H2O2 levels and lipoxygenase activity while ascorbate (AsA) declined significantly. However, reduced glutathione (GSH) content showed an increase at 0.5 mM CdCl2, but glutathione disulfide (GSSG) increased at any level of Cd with a decrease in GSH/GSSG ratio. The activities of ascorbate peroxidase (APX) and glutathione S-transferase (GST) upregulated due to Cd treatment in dose-dependent manners, while glutathione reductase (GR) and glutathione peroxidase (GPX) increased only at 0.5 mM CdCl2 and decreased at higher dose. The activity of monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), catalase (CAT), glyoxalase I (Gly I), and glyoxalase II (Gly II) decreased under Cd stress. On the other hand, H2O2 pretreated seedlings, when exposed to Cd, AsA and GSH contents and GSH/GSSG ratio increased noticeably. H2O2 pretreatment increased the activities of APX, MDHAR, DHAR, GR, GST, GPX, and CAT of Cd affected seedlings. Thus enhancement of both the non-enzymatic and enzymatic antioxidants helped to decrease the oxidative damage as indicated by decreased levels of H2O2 and MDA. The seedlings which were pretreated with H2O2 also showed enhanced glyoxalase system. The activities of Gly I, and Gly II and the content of GSH increased significantly due to H2O2 pretreatment in Cd affected seedlings, compared to the Cd-stressed plants without H2O2 pretreatment which were vital for methylglyoxal

  10. 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.

  11. Quantifying intracellular hydrogen peroxide perturbations in terms of concentration

    PubMed Central

    Huang, Beijing K.; Sikes, Hadley D.

    2014-01-01

    Molecular level, mechanistic understanding of the roles of reactive oxygen species (ROS) in a variety of pathological conditions is hindered by the difficulties associated with determining the concentration of various ROS species. Here, we present an approach that converts fold-change in the signal from an intracellular sensor of hydrogen peroxide into changes in absolute concentration. The method uses extracellular additions of peroxide and an improved biochemical measurement of the gradient between extracellular and intracellular peroxide concentrations to calibrate the intracellular sensor. By measuring peroxiredoxin activity, we found that this gradient is 650-fold rather than the 7–10-fold that is widely cited. The resulting calibration is important for understanding the mass-action kinetics of complex networks of redox reactions, and it enables meaningful characterization and comparison of outputs from endogenous peroxide generating tools and therapeutics across studies. PMID:25460730

  12. Oxygen K-shell excitation spectroscopy of hydrogen peroxide

    NASA Astrophysics Data System (ADS)

    Rühl, E.; Hitchcock, A. P.

    1991-07-01

    The absolute oscillator strength spectrum for oxygen K-shell excitation of hydrogen peroxide has been derived from electron energy loss spectra recorded under electric dipole scattering conditions. The spectrum is dominated by an intense low-lying excitation to the {O 1s -1, σ* (OO)} state at 533.0 eV. The spectrum is compared to the O 1 s spectra of bis (trifluoromethyl) peroxide and bis( t-butyl)peroxide. The spectra of all three peroxides exhibit a strong transition around 533 eV which involves O 1s promotions to an orbital of largely σ* (OO) character. The bond length-σ* resonance energy correlation and its relation to near-edge X-ray absorption fine structure (NEXAFS) determinations of the geometry of O 2 adsorbed on various metal surfaces is explored.

  13. 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.

  14. 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 178.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) INDIRECT FOOD ADDITIVES: ADJUVANTS, PRODUCTION AIDS, AND SANITIZERS Substances Utilized To Control...

  15. 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.

  16. Evaluation of a new hydrogen peroxide wipe disinfectant.

    PubMed

    Boyce, John M; Havill, Nancy L

    2013-05-01

    A new activated hydrogen peroxide wipe disinfectant was used to disinfect 10 high-touch surfaces in 72 patient rooms. After cleaning, 99% of surfaces yielded less than 2.5 colony-forming units/cm(2), 75% yielded no growth, and 70% yielded adenosine triphosphate counts of less than 250 relative light units. The new disinfectant was highly effective.

  17. 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.

  18. 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.

  19. 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.

  20. Protective effect of enzymatic hydrolysates from highbush blueberry (Vaccinium corymbosum L.) against hydrogen peroxide-induced oxidative damage in Chinese hamster lung fibroblast cell line.

    PubMed

    Senevirathne, Mahinda; Kim, Soo-Hyun; Jeon, You-Jin

    2010-06-01

    Blueberry was enzymatically hydrolyzed using selected commercial food grade carbohydrases (AMG, Celluclast, Termamyl, Ultraflo and Viscozyme) and proteases (Alcalase, Flavourzyme, Kojizyme, Neutrase and Protamex) to obtain water soluble compounds, and their protective effect was investigated against H(2)O(2)-induced damage in Chinese hamster lung fibroblast cell line (V79-4) via various published methods. Both AMG and Alcalase hydrolysates showed higher total phenolic content as well as higher cell viability and ROS scavenging activities, and hence, selected for further antioxidant assays. Both AMG and Alcalase hydrolysates also showed higher protective effects against lipid peroxidation, DNA damage and apoptotic body formation in a dose-dependent fashion. Thus, the results indicated that water soluble compounds obtained by enzymatic hydrolysis of blueberry possess good antioxidant activity against H(2)O(2)-induced cell damage in vitro.

  1. 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.

  2. Glycerophosphate-dependent hydrogen peroxide production by brown adipose tissue mitochondria and its activation by ferricyanide.

    PubMed

    Drahota, Zdenek; Chowdhury, Subir K R; Floryk, Daniel; Mrácek, Tomás; Wilhelm, Jirí; Rauchová, Hana; Lenaz, Giorgio; Houstek, Josef

    2002-04-01

    Oxidation of glycerophosphate (GP) by brown adipose tissue mitochondria in the presence of antimycin A was found to be accompanied by significant production of hydrogen peroxide. GP-dependent hydrogen peroxide production could be detected by p-hydroxyphenylacetate fluorescence changes or as an antimycin A-insensitive oxygen consumption. One-electron acceptor, potassium ferricyanide, highly stimulated the rate of GP-dependent antimycin A-insensitive oxygen uptake, which was prevented by inhibitors of mitochondrial GP dehydrogenase (mGPDH) or by coenzyme Q (CoQ). GP-dependent ferricyanide-induced peroxide production was also determined luminometrically, using mitochondria or partially purified mGPDH. Ferricyanide-induced peroxide production was negligible, when succinate or NADH was used as a substrate. These results indicate that hydrogen peroxide is produced directly by mGPDH and reflect the differences in the transport of reducing equivalents from mGPDH and succinate dehydrogenase to the CoQ pool. The data suggest that more intensive production of reactive oxygen species may be present in mammalian cells with active mGPDH.

  3. Hydrogen Peroxide: A Key Chemical for Today's Sustainable Development.

    PubMed

    Ciriminna, Rosaria; Albanese, Lorenzo; Meneguzzo, Francesco; Pagliaro, Mario

    2016-12-20

    The global utilization of hydrogen peroxide, a green oxidant that decomposes in water and oxygen, has gone from 0.5 million tonnes per year three decades ago to 4.5 million tonnes per year in 2014, and is still climbing. With the aim of expanding the utilization of this eminent green chemical across different industrial and civil sectors, the production and use of hydrogen peroxide as a green industrial oxidant is reviewed herein to provide an overview of the explosive growth of its industrial use over the last three decades and of the state of the art in its industrial manufacture, with important details of what determines the viability of the direct production from oxygen and hydrogen compared with the traditional auto-oxidation process.

  4. Investigation on regeneration of basic hydrogen peroxide by electrochemical methods

    NASA Astrophysics Data System (ADS)

    Ke, Changchun; Chen, Wenwu; Xu, Xiaobo; Wang, Jinglong; Liu, Yushi; Jin, Yuqi; Sang, Fengting

    2015-02-01

    Two electrochemical methods for regeneration of Basic Hydrogen Peroxide (BHP) were investigated in this paper, which could be called one-step method and two-step method, respectively, distinguished by the number of steps during the regeneration process. The one-step method converts potassium chloride solution and oxygen directly to chlorine and BHP by a modified chlor-alkali cell with an oxygen cathode. For the one-step method, two reactors of different structure and corresponding regenerating process were designed. The experimental results showed that, for the continuous-type reactor, the highest peroxide concentration was 0.042 mol/L, while for batch-type reactor the highest peroxide concentration was 0.563 mol/L. The two-step method accomplishes the regeneration of BHP by a conventional chlor-alkali cell combined with a fuel cell reactor which could convert hydrogen and oxygen to peroxide in alkaline potassium hydroxide solution. A peroxide concentration of 2.450 mol/L was obtained for the two-step method.

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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.

  1. Hydrogen peroxide modified sodium titanates with improved sorption capabilities

    DOEpatents

    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.

  2. Preparation of vermiculite nanoparticles using thermal hydrogen peroxide treatment.

    PubMed

    Weiss, Zdenĕk; Valásková, Marta; Seidlerová, Jana; Supová-Krístková, Monika; Sustai, Ondrej; Matĕjka, Vlastimil; Capková, Pavla

    2006-03-01

    Powdered natural Mg-vermiculite (Letovice, Czech Republic), with the formula (Mg0.35K0.02Ca0.01) (Mg2.39Fe0.51(3+)Fe0.02(2+)Al0.08) (Si2.64Al1.33Ti0.03) O10(OH)2 x 4.97H2O and particle size < 5 microm, was used for the investigation of exfoliation after hydrogen peroxide and/or microwave treatment (600 W). A sample heated in the microwave oven for 40 min exhibits a 11% mass loss and reduction of the 001 peak intensity in the X-ray diffraction pattern. The basal 001 peak intensity of untreated Mg-vermiculite sample (/001 = 100%) drops to 35% in the microwave treated sample. Only the sample treated for 5 h at 80 degrees C fully rehydrated after 120 min at room temperature. A more pronounced reduction of the 001 peak intensity (to 8%) was observed after hydrogen peroxide treatment of the sample at 25 degrees C. The combination of a five-hour hydrogen peroxide treatment at 80 degrees C and subsequent microwave heating leads to an effective extinction of the 001 diffraction in the XRD pattern. The 001 diffraction profile becomes very diffuse with peak intensity less than 1%. The degree of reduction of the 001 diffraction intensity also depends on the time and temperature of hydrogen peroxide treatment and on the peroxide concentration. An even more pronounced reduction of the peak intensity is caused by exfoliation of particles to nano-domains coupled with a randomization of the c-axes.

  3. 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

  4. 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.

  5. 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.

  6. Direct synthesis of hydrogen peroxide from plasma-water interactions

    PubMed Central

    Liu, Jiandi; He, Bangbang; Chen, Qiang; Li, Junshuai; Xiong, Qing; Yue, Guanghui; Zhang, Xianhui; Yang, Size; Liu, Hai; Liu, Qing Huo

    2016-01-01

    Hydrogen peroxide (H2O2) is usually considered to be an important reagent in green chemistry since water is the only by-product in H2O2 involved oxidation reactions. Early studies show that direct synthesis of H2O2 by plasma-water interactions is possible, while the factors affecting the H2O2 production in this method remain unclear. Herein, we present a study on the H2O2 synthesis by atmospheric pressure plasma-water interactions. The results indicate that the most important factors for the H2O2 production are the processes taking place at the plasma-water interface, including sputtering, electric field induced hydrated ion emission, and evaporation. The H2O2 production rate reaches ~1200 μmol/h when the liquid cathode is purified water or an aqueous solution of NaCl with an initial conductivity of 10500 μS cm−1. PMID:27917925

  7. 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

    2014-04-05

    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.

  8. Possible involvement of hydroxyl radical on the stimulation of tetrahydrobiopterin synthesis by hydrogen peroxide and peroxynitrite in vascular endothelial cells.

    PubMed

    Shimizu, Shunichi; Ishii, Masakazu; Miyasaka, Yoshiyuki; Wajima, Teruaki; Negoro, Takaharu; Hagiwara, Tamio; Kiuchi, Yuji

    2005-04-01

    We recently described that hydrogen peroxide (H2O2) stimulates the synthesis of tetrahydrobiopterin (BH4) through the induction of the rate-limiting enzyme GTP-cyclohydrolase I (GTPCH), and increases tetrahydrobiopterin content in vascular endothelial cells. Tetrahydrobiopterin is easily oxidized by peroxynitrite (ONOO-), but not by hydrogen peroxide. The aim of this study was to determine the effect of hydroxyl radical and peroxynitrite, which are both toxic biological oxidants, on tetrahydrobiopterin synthesis and the regulation of its content in vascular endothelial cells. In the cell-free assay system, tetrahydrobiopterin was rapidly oxidized by the hydroxyl radical and peroxynitrite, but not by hydrogen peroxide. However, the addition of not only hydrogen peroxide but also the hydroxyl radical and peroxynitrite to vascular endothelial cells transiently decreased tetrahydrobiopterin content, and then markedly increased its content. Interestingly, total biopterin content was also decreased by early treatment with oxidants. Moreover, oxidants induced the expression of GTP-cyclohydrolase I, and the increase of the tetrahydrobiopterin content was blocked by the treatment with GTP-cyclohydrolase I inhibitor. Both the hydrogen peroxide- and peroxynitrite-induced increases in tetrahydrobiopterin content and findings suggest that not only hydrogen peroxide but also the hydroxyl radical and peroxynitrite stimulates tetrahydrobiopterin synthesis through GTP-cyclohydrolase I expression, and that the hydroxyl radical plays a central role in the stimulation of tetrahydrobiopterin synthesis. Moreover, the transient decrease in BH4 to tetrahydrobiopterin.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Effect of hydrogen peroxide on antioxidant enzyme activities in Saccharomyces cerevisiae is strain-specific.

    PubMed

    Bayliak, M; Semchyshyn, H; Lushchak, V

    2006-09-01

    The effect of hydrogen peroxide on the survival and activity of antioxidant and associated enzymes in Saccharomyces cerevisiae has been studied. A difference found in the response of wild-type yeast strains treated with hydrogen peroxide was probably related to the different protective effects of antioxidant enzymes in these strains. Exposure of wild-type YPH250 cells to 0.25 mM H(2)O(2) for 30 min increased activities of catalase and superoxide dismutase (SOD) by 3.4- and 2-fold, respectively. However, no activation of catalase in the EG103 strain, as well as of SOD in the YPH98 and EG103 wild strains was detected, which was in parallel to lower survival of these strains under oxidative stress. There is a strong positive correlation (R(2) = 0.95) between activities of catalase and SOD in YPH250 cells treated with different concentrations of hydrogen peroxide. It is conceivable that catalase would protect SOD against inactivation caused by oxidative stress and vice versa. Finally, yeast cell treatment with hydrogen peroxide can lead to either a H(2)O(2)-induced increase in activities of antioxidant and associated enzymes or their decrease depending on the H(2)O(20 concentration used or the yeast strain specificity.

  15. Direct synthesis of hydrogen peroxide in water at ambient temperature.

    PubMed

    Crole, David A; Freakley, Simon J; Edwards, Jennifer K; Hutchings, Graham J

    2016-06-01

    The direct synthesis of hydrogen peroxide (H2O2) from hydrogen and oxygen has been studied using an Au-Pd/TiO2 catalyst. The aim of this study is to understand the balance of synthesis and sequential degradation reactions using an aqueous, stabilizer-free solvent at ambient temperature. The effects of the reaction conditions on the productivity of H2O2 formation and the undesirable hydrogenation and decomposition reactions are investigated. Reaction temperature, solvent composition and reaction time have been studied and indicate that when using water as the solvent the H2O2 decomposition reaction is the predominant degradation pathway, which provides new challenges for catalyst design, which has previously focused on minimizing the subsequent hydrogenation reaction. This is of importance for the application of this catalytic approach for water purification.

  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. 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.

  18. Luminol-hydrogen peroxide chemiluminescence produced by sweet potato peroxidase.

    PubMed

    Alpeeva, Inna S; Yu Sakharov, Ivan

    2007-01-01

    Anionic sweet potato peroxidase (SPP; Ipomoea batatas) was shown to efficiently catalyse luminol oxidation by hydrogen peroxide, forming a long-term chemiluminescence (CL) signal. Like other anionic plant peroxidases, SPP is able to catalyse this enzymatic reaction efficiently in the absence of any enhancer. Maximum intensity produced in SPP-catalysed oxidation of luminol was detected at pH 7.8-7.9 to be lower than that characteristic of other peroxidases (8.4-8.6). Varying the concentrations of luminol, hydrogen peroxide and Tris buffer in the reaction medium, we determined favourable conditions for SPP catalysis (100 mmol/L Tris-HCl buffer, pH 7.8, containing 5 mmol/L hydrogen peroxide and 8 mmol/L luminol). The SPP detection limit in luminol oxidation was 1.0 x 10(-14) mol/L. High sensitivity in combination with the long-term CL signal and high stability is indicative of good promise for the application of SPP in CL enzyme immunoassay.

  19. Treatment of ammonia contaminated water by ozone and hydrogen peroxide

    SciTech Connect

    Yuan, F.; Hill, D.O.; Kuo, C.H.

    1995-12-31

    The present research concerns kinetics of oxidation of ammonia by ozone and ozone-hydrogen peroxide mixtures in alkaline solutions. Experiments were carried out at 15 to 35{degrees}C in solutions with pH values varying from 8 to 10 utilizing a stopped-flow spectrophotometer system. Fractions of free ammonia present in acidic and neutral solutions are negligible, and the reaction is very slow. This confirms that only free ammonia can react with ozone in the aqueous phase. The reaction proceeds at moderate rates in the alkaline solutions requiring four moles of ozone to react with each mole of ammonia. The free ammonia is oxidized and converted completely to nitrate in the solutions. The overall reaction between ammonia and ozone is second order with first order in each reactant. The reaction rate constant increases with temperature and pH value of the solution. The average activation energy is 59 Kcal/gmol for all systems investigated at different pH values. The results of the kinetic experiments suggest that the reaction is predominated by the direct oxidation between ammonia and ozone molecules, and that the hydroxyl radical reactions play insignificant roles in the ozonation process. The oxidation rate of ammonia is enhanced considerably in the presence of hydrogen peroxide and ozone mixtures. The formation of hydroxyl radical from interactions between ozone and hydrogen peroxide and the subsequent free radical reactions of ammonia seem important in controlling the destruction rate of free ammonia, as suggested by the results of this study.

  20. Reactive oxygen species induce apoptosis in bronchial epithelial BEAS-2B cells by inhibiting the antiglycation glyoxalase I defence: involvement of superoxide anion, hydrogen peroxide and NF-κB.

    PubMed

    Antognelli, Cinzia; Gambelunghe, Angela; Talesa, Vincenzo Nicola; Muzi, Giacomo

    2014-01-01

    Reactive oxygen species (ROS) are implicated in the regulation of apoptosis through a number of distinct mechanisms depending on cell type and stimulation conditions. Glyoxalase I (GI) metabolizes methylglyoxal (MG) and MG-derived advanced glycation end products (AGEs) known to cause apoptosis. This study examined the possible role of GI among the mechanisms of ROS-driven apoptosis in human bronchial epithelial BEAS-2B cells exposed to wood dust and signaling pathways by which these reactive species regulate GI expression. Our results showed that wood dust generated distinct ROS (superoxide anion, and hydrogen peroxide) by selectively inhibiting the enzymatic activity of superoxide dismutase or glutathione peroxidase and catalase enzymes. These ROS caused a dramatic inhibition of the antiglycation GI enzyme, leading to the intracellular accumulation of the pro-apoptotic AGE, argpyrimidine (AP) and programmed cell death via a mitochondrial pathway. Pre-treatment with N-acetyl-L-cysteine (NAC), a ROS scavenger, prevented these events. Hence, ROS-induced apoptosis in BEAS-2B cells occurred via a novel mechanism relying on GI inhibition and AP accumulation. We interestingly found that superoxide anion and hydrogen peroxide induced a diverse apoptosis level by differently inhibiting GI via NF-κB pathway. Since maintenance of an intact epithelium is a critically important determinant of normal respiratory function, the knowledge of the mechanisms underlying its disruption may provide insight into the genesis of a number of pathological conditions commonly occurring in wood dust occupational exposure. Our findings suggest that the antioxidant NAC may merit investigation as a potential preventive agent in wood dust exposure-induced respiratory diseases.

  1. 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

  2. Improving the hydrogen peroxide bleaching efficiency of aspen chemithermomechanical pulp by using chitosan.

    PubMed

    Li, Zongquan; Dou, Hongyan; Fu, Yingjuan; Qin, Menghua

    2015-11-05

    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.

  3. Multiple protective mechanisms of alpha-lipoic acid in oxidation, apoptosis and inflammation against hydrogen peroxide induced toxicity in human lymphocytes.

    PubMed

    Rahimifard, Mahban; Navaei-Nigjeh, Mona; Baeeri, Maryam; Maqbool, Faheem; Abdollahi, Mohammad

    2015-05-01

    The naturally antioxidant and coenzyme, alpha-lipoic acid (α-LA), has gained considerable attention regarding different functions and therapeutically effective in treating oxidative stress-associated diseases in the human body. This study was designed to examine the protective effect of α-LA against H2O2-induced oxidative stress and apoptosis in human lymphoid cells. Human peripheral blood lymphocytes were preincubated with α-LA and then exposed to H2O2. After that, the viability of the cells, rate of apoptosis, oxidative stress biomarkers such as reactive oxygen species (ROS) and level of lipid peroxidation (LPO), and also tumor necrosis factor-α (TNF-α) were studied. Pretreatment of lymphocytes with α-LA, dramatically enhanced viability of the cells and decreased apoptosis. Investigation of caspases gives a clear picture of the mechanism by which α-LA decreases ROS and causes a reduction in apoptosis through caspase-9-dependent mitochondrial pathway. Furthermore, α-LA dose dependently decreased oxidative stress by a reduction in level of LPO, and the dose of 1000 µM indicates a significant decrease (p < 0.01) in TNF-α level. Collectively, the present data show that α-LA is an ideal compound which has profound protective effects on oxidation, inflammation, and apoptosis. As a result, α-LA may indicate a new way toward the development of antioxidant therapy.

  4. Direct reduction of hydrogen peroxides into hydroxyl ions in peroxide-based fuel cell

    NASA Astrophysics Data System (ADS)

    Luo, Nie; Miley, George H.; Noid, D. W.

    2004-03-01

    We study the catalytic electrochemical reduction of hydrogen peroxide (H_2O2 + 2 e = 2 OH^-) at the electrolyte/cathode interface of peroxide fuel cells. This is the desired reaction for high efficiency fuel cell operation, but is nevertheless in competition with wasteful processes such as the direct decomposition of H_2O2 to water and oxygen gas. The reaction kinetics of these competing processes is calculated with thermodynamic and electrochemical data of relevant materials, resulting in a qualitative guide on the selection of effective catalyst and cathode compositions. The experimental research includes cyclic voltammetry, used to probe the surface electrochemistry of the catalytic process, and shed light on how proper theories are restricted experimentally. The fuel cell based on direct hydrogen peroxide cathode has the following distinct advantages: i) Very high volumetric power density (several times higher than ordinary H_2O2 fuel cells) through direct utilization of a liquid phase oxidant at the cathode; (ii) The potential for high efficiency (over 60%): use of H_2O2 eliminates the oxygen over-potential problem inherent to ordinary H_2O2 fuel cell designs, which require transfer of four electrons simultaneously; (iii) Safe, and stable storage of the energetic materials.

  5. 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.

  6. Small heterodimer partner attenuates hydrogen peroxide-induced expression of cyclooxygenase-2 and inducible nitric oxide synthase by suppression of activator protein-1 and nuclear factor-κB in renal proximal tubule epithelial cells.

    PubMed

    Park, Jung Sun; Choi, Hoon In; Bae, Eun Hui; Ma, Seong Kwon; Kim, Soo Wan

    2017-03-01

    The orphan nuclear receptor, small heterodimer partner (SHP), plays a negative regulatory role in innate immune responses and is involved in various inflammatory signaling pathways. In the present study, we aimed to ascertain whether SHP is effective in preventing hydrogen peroxide (H2O2)-induced kidney tubular inflammation and explored the molecular mechanisms underlying the protective effects of SHP. Renal ischemia/reperfusion (I/R) injury was induced in mice by clamping both renal pedicles for 30 min. The effects of H2O2 on cell viability in human renal proximal tubule (HK-2) cells were determined using MTT assays. 2',7'-DCF-DA was used to determine intracellular reactive oxygen species (ROS). SHP, cyclooxygenase-2 (COX-2) levels, and inducible nitric oxide synthase (iNOS) expression levels were determined by semi-quantitative immunoblotting and real-time polymerase chain reaction. In addition, SHP, nuclear factor-κB (NF-κB), and activator protein-1 (AP-1) promoter activities were determined by luciferase assays. SHP mRNA and protein expression levels were reduced, whereas COX-2 and iNOS levels were increased in mice subjected to renal I/R. H2O2 treatment in HK-2 cells decreased cell viability, increased ROS production, and induced COX-2 and iNOS expression. These changes were counteracted by transient transfection with SHP. H2O2 treatment decreased SHP luciferase activity, which was recovered by treatment with the NF-κB inhibitor Bay11-7082, transfection with dominant-negative c-Jun or treatment with N-acetyl cysteine (NAC). AP-1 and NF-κB promoter activities were increased by H2O2 and this increase was blocked by SHP transfection. To conclude, SHP protected HK-2 cells from H2O2-induced tubular injury by inhibition of COX-2 and iNOS through suppression of AP-1 and NF-κB promoter activities.

  7. Changes in Gene Transcription Induced by Hydrogen Peroxide Treatment of Verotoxin-Producing Escherichia coli O157:H7 and Non-O157 Serotypes on Romaine Lettuce

    PubMed Central

    Mei, Gui-Ying; Tang, Joshua; Bach, Susan; Kostrzynska, Magdalena

    2017-01-01

    Disease outbreaks of verotoxin-producing Escherichia coli (VTEC) O157:H7 and non-O157 serotypes associated with leafy green vegetables are becoming a growing concern. A better understanding of the behavior of VTEC, particularly non-O157 serotypes, on lettuce under stress conditions is necessary for designing more effective control strategies. Hydrogen peroxide (H2O2) can be used as a sanitizer to reduce the microbial load in leafy green vegetables, particularly in fresh produce destined for the organic market. In this study, we tested the hypothesis that H2O2 treatment of contaminated lettuce affects in the same manner transcription of stress-associated and virulence genes in VTEC strains representing O157 and non-O157 serotypes. Six VTEC isolates representing serotypes O26:H11, O103:H2, O104:H4, O111:NM, O145:NM, and O157:H7 were included in this study. The results indicate that 50 mM H2O2 caused a population reduction of 2.4–2.8 log10 (compared to non-treated control samples) in all six VTEC strains present on romaine lettuce. Following the treatment, the transcription of genes related to oxidative stress (oxyR and sodA), general stress (uspA and rpoS), starvation (phoA), acid stress (gadA, gadB, and gadW), and virulence (stx1A, stx2A, and fliC) were dramatically downregulated in all six VTEC serotypes (P ≤ 0.05) compared to not treated control samples. Therefore, VTEC O157:H7 and non-O157 serotypes on lettuce showed similar survival rates and gene transcription profiles in response to 50 mM H2O2 treatment. Thus, the results derived from this study provide a basic understanding of the influence of H2O2 treatment on the survival and virulence of VTEC O157:H7 and non-O157 serotypes on lettuce. PMID:28377761

  8. 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.

  9. Antioxidative effects of diallyl trisulfide on hydrogen peroxide-induced cytotoxicity through regulation of nuclear factor-E2-related factor-mediated thioredoxin reductase 1 expression in C2C12 skeletal muscle myoblast cells.

    PubMed

    Kang, Ji Sook; Kim, Gi-Yiung; Kim, Byung Woo; Choi, Yung Hyun

    2017-04-01

    Diallyl trisulfide (DATS) is one of the major sulfur-containing compounds in garlic oil. In this study, we analyzed the effects of DATS against hydrogen peroxide (H2O2)-induced oxidative stress in C2C12 myoblasts. DATS preconditioning significantly attenuated H2O2-induced growth inhibition and DNA damage, as well as apoptosis by decreasing the generation of ROS. Treatment with DATS alone effectively upregulated the expression of nuclear factor-erythroid 2-related factor 2 (Nrf2) and thioredoxin reductase 1 (TrxR1), which was associated with the increased phosphorylation of Nrf2. However, the protective effects of DATS against H2O2-induced growth reduction and ROS accumulation were significantly abolished by auranofin, an inhibitor of TrxR activity. Moreover, DATS-mediated phosphorylation of Nrf2 and induction of TrxR1 were markedly reduced by genetic silencing of Nrf2. DATS treatment also induced the phosphorylation extracellular signal-regulating kinase (ERK), and analysis using specific inhibitors of cellular signaling pathways demonstrated that only ERK activation was involved in Nrf2 phosphorylation and TrxR1 induction. In addition, the cytoprotective potentials were abrogated in C2C12 cells pretreated with an ERK specific inhibitor. The results demonstrate that DATS protects against oxidative stress-induced DNA damage and apoptosis in C2C12 cells in part through the activation of Nrf2-mediated TrxR1 induction via the ERK signaling pathway.

  10. 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.

  11. 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.

  12. 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)

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. Hydrogen peroxide tooth-whitening (bleaching): review of safety in relation to possible carcinogenesis.

    PubMed

    Naik, Supritha; Tredwin, Christopher Jeremy; Scully, Crispian

    2006-08-01

    Hydrogen peroxide in the form of carbamide peroxide is widely used in professionally and self-administered products for tooth whitening. Hydrogen peroxide is a highly reactive substance that can damage oral soft and hard tissues when present in high concentrations and with exposures of prolonged duration. This review examines the issue of oral mucosal damage and possible carcinogenicity relating to the use of hydrogen peroxide in the mouth for tooth whitening, with an emphasis on safety with prolonged exposure to low concentrations of peroxide products.

  18. Hydrogen Peroxide as an Effective Disinfectant for Pasteurella multocida

    PubMed Central

    Jung, In-Soo; Kim, Hyun-Jung; Jung, Won-Yong

    2014-01-01

    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. PMID:24954350

  19. 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.

  20. Historical Survey: German Research on Hydrogen Peroxide/Alcohol Explosives

    SciTech Connect

    Parmeter, John E.

    2015-01-01

    Discussion of HP/fuel explosives in the scientific literature dates back to at least 1927. A paper was published that year in a German journal entitled On Hydrogen Peroxide Explosives [Bamberger and Nussbaum 1927]. The paper dealt with HP/cotton/Vaseline formulations, specifically HP89/cotton/Vaseline (76/15/9) and (70/8.5/12.5). The authors performed experiments with charge masses of 250-750 g and charge diameters of 35-45 mm. This short paper provides brief discussion on the observed qualitative effects of detonations but does not report detonation velocities.

  1. 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.

  2. 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

    2015-02-05

    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.

  3. The requirement for and mobilization of calcium during induction by sodium ascorbate and by hydrogen peroxide of cell death.

    PubMed

    Sakagami, H; Kuribayashi, N; Iida, M; Hagiwara, T; Takahashi, H; Yoshida, H; Shiota, F; Ohata, H; Momose, K; Takeda, M

    1996-01-01

    The requirement for and mobilization of Ca2+ ions during induction of cell death by sodium ascorbate were compared with those during induction of cell death by hydrogen peroxide. When HL-60 cells were incubated with sodium ascorbate, a rapid increase in the intracellular concentration of Ca2+ ions and subsequent apoptotic cell death, characterized by cell shrinkage, nuclear fragmentation and cleavage of internucleosomal DNA to yield fragments that were multiples of 180-200 base pairs, were induced. However, these effects of sodium ascorbate were significantly reduced in Ca2+-depleted medium. By contrast, hydrogen peroxide induced similar apoptosis associated phenomena in the presence and in the absence of extracellular Ca2+ ions. The intracellular concentration of the reduced form of glutathione was not significantly affected and glutathione disulfide was undetectable during the early stages of apoptosis. These data suggest that sodium ascorbate and hydrogen peroxide initiate cell death by different mechanisms.

  4. 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.

  5. [Oxidative destruction of estradiol after treatment with hydrogen peroxide catalyzed by horseradish peroxidase and methemoglobin].

    PubMed

    Petrenko, Iu M; Matiushin, A I; Titov, V Iu

    1999-01-01

    It is shown that estradiol in the presence of horse radish peroxidase interacts with hydrogen peroxide, which is evidenced by an increase in its optical density at 280 nm. The photometering of samples containing estradiol and horse radish peroxidase upon their titration with hydrogen peroxide indicated that the increase in optical density stops after introducing hydrogen peroxide equimolar in concentration to estradiol. The stoichiometric ratio of estradiol consumed during oxidative destruction to hydrogen peroxide was 1:1. In the presence of ascorbate, the oxidative destruction of estradiol by the action of hydrogen peroxide, catalyzed by horse radish peroxidase, was observed only after a latent period and showed the same regularities as in the absence of ascorbate. It was found by calorimetry that, during the latent period, estradiol catalyzes the degradation of hydrogen peroxide and ascorbate without undergoing oxidative destruction. The substrates of the peroxidase reaction benzidine, 1-naphthol, and phenol interact with hydrogen peroxide in the presence of ascorbate and horse radish peroxidase in a similar way. Presumably, upon interaction with hydrogen peroxide in the presence of horse radish peroxidase, estradiol, like other substrates of this reaction, undergoes oxidative destruction by the mechanism of peroxidase reaction. It is shown that oxidative destruction of estradiol by the action of hydrogen peroxide can also be catalyzed by methemoglobin by the same mechanism. These data are important for understanding the role of estradiol in the organism and the pathways of its metabolic conversions.

  6. 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

    2013-11-08

    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.

  7. Direct reduction of hydrogen peroxides into hydroxyl ions in peroxide-based fuel cells

    NASA Astrophysics Data System (ADS)

    Luo, Nie; Miley, George; Noid, Don; Chubb, Scott

    2004-03-01

    The physics of catalytic electrochemical reduction of hydrogen peroxide (H2O2 + 2 e = 2 OH-) at the electrolyte/cathode interface of peroxide fuel cells is under study. This reaction is ideally suited for high efficiency fuel cell operation, but is nevertheless in competition with wasteful processes such as the direct decomposition of H2O2 to water and oxygen gas. The reaction kinetics of these competing processes are calculated with thermodynamic and electrochemical data of relevant materials, resulting in a qualitative guide to the selection of effective catalyst and cathode compositions. The experimental research includes cyclic voltammetry, used to probe the surface electrochemistry of the catalytic process, and to shed light on how a correct theoretical understanding is restricted experimentally. A fuel cell based on direct hydrogen peroxide cathode has the following distinct advantages: i) Very high volumetric power density (several times higher than conventional H2/O2 fuel cells) due to direct utilization of a liquid phase oxidant at the cathode; (ii) The potential for a very high efficiency (over 60%) because the use of H2O2 overcomes the oxygen over-potential problem (slow O2 reduction kinetics) inherent to a H2/O2 fuel cell designs, which require simultaneous transfer of four electrons; (iii) Safe, and long time stable storage of the energetic materials for fuel cells in special environment (space, underwater, etc.). The measurement on open cell voltage, short-circuit current density shows an improved performance compared to a typical H2/O2 fuel cell, indicating a higher efficiency at similar discharge conditions.

  8. Sphingosine-1-phosphate (S1P) mediates darkness-induced stomatal closure through raising cytosol pH and hydrogen peroxide (H₂O₂) levels in guard cells in Vicia faba.

    PubMed

    Ma, Yinli; She, Xiaoping; Yang, Shushen

    2012-11-01

    The role and signaling of sphingosine-1-phosphate (S1P) during darkness-induced stomatal closure were examined in Vicia faba. Darkness substantially raised S1P and hydrogen peroxide (H(2)O(2)) levels and closed stomata. These darkness effects were significantly suppressed by DL-threo-dihydrosphingosine (DL-threo-DHS) and N,N-dimethylsphingosine (DMS), two inhibitors of long-chain base kinases. Exogenous S1P led to stomatal closure and H(2)O(2) production, and the effects of S1P were largely prevented by the H(2)O(2) modulators ascorbic acid, catalase, and diphenyleneiodonium. These results indicated that S1P mediated darkness-induced stomatal closure by triggering H(2)O(2) production. In addition, DL-threo-DHS and DMS significantly suppressed both darkness-induced cytosolic alkalization in guard cells and stomatal closure. Exogenous S1P caused cytosolic alkalization and stomatal closure, which could be largely abolished by butyric acid. These results demonstrated that S1P synthesis was necessary for cytosolic alkalization during stomatal closure caused by darkness. Furthermore, together with the data described above, inhibition of darkness-induced H(2)O(2) production by butyric acid revealed that S1P synthesis-induced cytosolic alkalization was a prerequisite for H(2)O(2) production during stomatal closure caused by darkness, a conclusion supported by the facts that the pH increase caused by exogenous S1P had a shorter lag and peaked faster than H(2)O(2) levels and that butyric acid prevented exogenous S1P-induced H(2)O(2) production. Altogether, our data suggested that darkness induced S1P synthesis, causing cytosolic alkalization and subsequent H(2)O(2) production, finally leading to stomatal closure.

  9. An Investigation into the Effect of Stabiliser Content on the Minimum Characteristic Chamber Length for Homogeneously-Catalysed Hydrogen Peroxide

    DTIC Science & Technology

    2007-11-02

    rate. 15. SUBJECT TERMS Hydrogen peroxide, high test peroxide, HTP , rocket grade hydrogen peroxide, RGHP, stabilized hydrogen...homogeneous catalytic decomposition of hydrogen peroxide (often referred to as ’high test peroxide’, or HTP - here used in a general sense to...207< Tc < 516 deg C, depending on the HTP concentration. 3. THE TEST RIG DELTACAT Ltd runs a small test -site in Hampshire, England. Recently

  10. Peroxide induced ultra-weak chemiluminescence and its application in analytical chemistry.

    PubMed

    Lin, Zhen; Chen, Hui; Lin, Jin-Ming

    2013-09-21

    Chemiluminescence (CL), as a sensitive, rapid, and facile analytical method, has been widely applied in environmental monitoring, clinical diagnosis and food safety. Recently, the main challenge and research interest in the CL study have been focused on exploring new CL systems and obtaining new insight into the interaction between CL reagents. The peroxide induced ultra-weak CL reactions are some new arising systems that have received great attention and have been successfully applied in many fields. The peroxide includes hydrogen peroxide, peroxynitrite, peroxymonocarbonate, peroxomonosulphate and so on. This review paper covers the mechanism of the peroxide induced ultra-weak CL and the analytical applications of the CL have also been summarized. The future prospects for the peroxide induced ultra-weak CL are discussed.

  11. Hydrogen Peroxide and Sodium Transport in the Lung and Kidney

    PubMed Central

    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

  12. 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.

  13. 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.

  14. 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

  15. The alpha-hemolysin of Streptococcus gordonii is hydrogen peroxide.

    PubMed Central

    Barnard, J P; Stinson, M W

    1996-01-01

    The alpha-hemolysin of viridans group streptococci, which causes greening of intact erythrocytes, is a potential virulence factor as well as an important criterion for the laboratory identification of these bacteria; however, it has never been purified and characterized. The alpha-hemolysin of Streptococcus gordonii CH1 caused characteristic shifts in the A403, A430, A578, and A630 of sheep hemoglobin. A spectrophotometric assay was developed and used to monitor purification of alpha-hemolysin during extraction in organic solvents and separation by reverse-phase high-performance liquid chromatography (HPLC). The alpha-hemolysin was identical to hydrogen peroxide with respect to its effects on erythrocyte hemoglobin, oxygen-dependent synthesis by streptococci, insensitivity to proteases, inactivation by catalase, differential solubility, failure to adsorb to ion-exchange chromatography resins, and retention time on a reverse-phase HPLC column. The amount of hydrogen peroxide present in HPLC-fractionated spent culture medium was sufficient to account for all alpha-hemolytic activity observed. PMID:8751938

  16. Effect of Hydrogen Peroxide on the Antibacterial Substantivity of Chlorhexidine

    PubMed Central

    Shahriari, Shahriar; Mohammadi, Zahed; Mokhtari, Mohammadi Mehdi; Yousefi, Rasoul

    2010-01-01

    The purpose of this in vitro study was to assess the effect of hydrogen peroxide on the antibacterial substantivity of chlorhexidine (CHX). Seventy-five dentine tubes prepared from human maxillary central and lateral incisor teeth were used. After contamination with Enterococcus faecalis for 14 days, the specimens were divided into five groups as follows: CHX, H2O2, CHX + H2O2, infected dentine tubes (positive control), and sterile dentine tubes (negative control). Dentine chips were collected with round burs into tryptic soy broth, and after culturing, the number of colony-forming units (CFU) was counted. The number of CFU was minimum in the first cultures in all experimental groups, and the results obtained were significantly different from each other at any time period (P < .05). At the first culture, the number of CFU in the CHX + H2O2 group was lower than other two groups. At the other experimental periods, the CHX group showed the most effective antibacterial action (P < .05). Hydrogen peroxide group showed the worst result at all periods. In each group, the number of CFU increased significantly by time lapse (P < .05). In conclusion, H2O2 had no additive effect on the residual antibacterial activity of CHX. PMID:21318180

  17. A low-volume microstructured optical fiber hydrogen peroxide sensor

    NASA Astrophysics Data System (ADS)

    Schartner, E. P.; Murphy, D. F.; Ebendorff-Heidepriem, H.; Monro, T. M.

    2011-05-01

    The ability to measure the concentration of hydrogen peroxide (H2O2) in solution is critical for quality assessment and control in many disparate applications, including wine, aviation fuels and IVF. The objective of this research is to develop a rapid test for the hydrogen peroxide content that can be performed on very low volume samples (i.e. sub-μL) that is relatively independent of other products within the sample. For H2O2 detection we use suspended core optical fibers to achieve a high evanescent field interaction with the fluid of interest, without the constraint of limited interaction length that is generally inherent with nanowire structures. By filling the holes of the fiber with an analyte/fluorophore solution we seek to create a quick and effective sensor that should enable detection of desired species within liquid media. By choosing a fluorophore that reacts with our target species to produce an increase in fluorescence, we can correlate observed fluorescence intensity with the concentration of the target molecule.

  18. 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.

  19. Pseudomonas aeruginosa Thiol Peroxidase Protects against Hydrogen Peroxide Toxicity and Displays Atypical Patterns of Gene Regulation

    PubMed Central

    Somprasong, Nawarat; Jittawuttipoka, Thichakorn; Duang-nkern, Jintana; Romsang, Adisak; Chaiyen, Pimchai; Schweizer, Herbert P.; Vattanaviboon, Paiboon

    2012-01-01

    The Pseudomonas aeruginosa PAO1 thiol peroxidase homolog (Tpx) belongs to a family of enzymes implicated in the removal of toxic peroxides. We have shown the expression of tpx to be highly inducible with redox cycling/superoxide generators and diamide and weakly inducible with organic hydroperoxides and hydrogen peroxide (H2O2). The PAO1 tpx pattern is unlike the patterns for other peroxide-scavenging genes in P. aeruginosa. Analysis of the tpx promoter reveals the presence of a putative IscR binding site located near the promoter. The tpx expression profiles in PAO1 and the iscR mutant, together with results from gel mobility shift assays showing that purified IscR specifically binds the tpx promoter, support the role of IscR as a transcriptional repressor of tpx that also regulates the oxidant-inducible expression of the gene. Recombinant Tpx has been purified and biochemically characterized. The enzyme catalyzes thioredoxin-dependent peroxidation and can utilize organic hydroperoxides and H2O2 as substrates. The Δtpx mutant demonstrates differential sensitivity to H2O2 only at moderate concentrations (0.5 mM) and not at high (20 mM) concentrations, suggesting a novel protective role of tpx against H2O2 in P. aeruginosa. Altogether, P. aeruginosa tpx is a novel member of the IscR regulon and plays a primary role in protecting the bacteria from submillimolar concentrations of H2O2. PMID:22609922

  20. 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.

  1. Cremophor EL augments the cytotoxicity of hydrogen peroxide in lymphocytes dissociated from rat thymus glands.

    PubMed

    Iwase, Kyoko; Oyama, Yasuo; Tatsuishi, Tomoko; Yamaguchi, Jun-ya; Nishimura, Yumiko; Kanada, Aimi; Kobayashi, Masako; Maemura, Yuko; Ishida, Shiro; Okano, Yoshiro

    2004-12-01

    The pharmaceutical uses of cremophor EL, a non-ionic surfactant, are similar to those of polysorbate 80. In our previous study, polysorbate 80 exerted some adverse actions on rat thymocytes under in vitro condition. Therefore, the effects of cremophor EL on thymic lymphocytes were examined using a flow cytometer with appropriate fluorescent dyes. Cremophor EL at 10 microg/ml or more (up to 300 microg/ml) concentration-dependently decreased cellular content of glutathione. The cell viability of thymocytes under control condition was 95.4 +/- 1.2% (n = 7, mean +/- S.D.). The incubation of thymocytes with 300 microg/ml cremophor EL or 3 mM hydrogen peroxide for 2 h, respectively, decreased the cell viability to 90.8 +/- 2.8% or 91.2 +/- 2.6%. However, the simultaneous incubation with cremophor EL and hydrogen peroxide decreased the cell viability to 28.7 +/- 8.2%. Cremophor EL at 100 microg/ml accelerated the process of cell death induced by hydrogen peroxide. Results suggest that cremophor EL increases the susceptibility to oxidative stress. Cremophor EL at clinically relevant concentrations may increase the therapeutic potential of some anticancer agents to produce oxidative stress.

  2. Analysis of the Color and Fluorescence Alterations of Enamel and Dentin Treated With Hydrogen Peroxide.

    PubMed

    Caneppele, Taciana Marco Ferraz; Rocha Gomes Torres, Carlos; Bresciani, Eduardo

    2015-10-01

    The aim of this study was to evaluate the effect of hydrogen peroxide whitening on fluorescence and color of bovine enamel and dentin. Twenty five dentin discs and 25 enamel discs, with 6 mm diameter and 1 mm thick, were obtained. Direct fluorescence (spectrofluorophotometry) and color (spectrophotometry) were assessed. After fluorescence and color baseline measurements, specimens were immersed in a 35% hydrogen peroxide (HP) solution for 1 h. This procedure was repeated after 7 days. Final fluorescence and color measurements were performed after the second immersion. Chemical characterization of 5 additional specimens was also performed. Data were submitted to repeated analysis of variance and Tukey's test for fluorescence and unpaired t-test for color and chemical components (p<0.05). Fluorescence decreased significantly in dentin specimens after whitening. Enamel presented lower fluorescence than dentin at baseline, but this parameter did not decrease after whitening. Color changes were observed for both substrates, with significantly greater whitening effect in dentin (ΔE=10.37) (p<0.001). Whitening by hydrogen peroxide induced significant decrease in fluorescence of tooth dentin and promoted significant color changes in dentin and enamel with more accentuated outcomes in dentin.

  3. 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.

  4. Exposure of cells to hydrogen peroxide can increase the intracellular accumulation of drugs.

    PubMed

    Funk, Ryan S; Krise, Jeffrey P

    2007-01-01

    One of the fastest growing areas of scientific research involves aspects of oxidative stress, either causes of or results from. Despite the enormous quantity of literature on the topic, surprisingly, the effects of oxidative stress on the pharmacokinetics of drugs have not been previously investigated. This is an extremely important concern, considering that the degree of oxidative stress that the human body experiences is known to be widely variable. Oxidative stress may be transiently increased, as is the case with some inflammatory episodes, or it may be chronically elevated, as is the case in some disease states, in aging, or with smokers. This report examines the influence of oxidative stress on the pharmacokinetics of model drugs utilizing cells in culture. Specifically, the effect of subtoxic, short-term exposure to hydrogen peroxide was investigated. Low micromolar, single doses of hydrogen peroxide were shown to cause dramatic increases in the apparent intracellular accumulation of model compounds with different physicochemical properties in different cell types. To examine the mechanistic basis for this, we evaluated possible hydrogen peroxide induced changes in cells including (1) intracellular pH, (2) membrane integrity, and (3) membrane fluidity (i.e., lateral membrane diffusion). We found no significant changes in pH or membrane integrity, but results were consistent with changes in hydrogen peroxide mediated reductions in lateral membrane diffusion, which we postulate facilitated the accumulation of the test substrates. Although studies presented here were all done in cell culture systems, we believe the findings could have substantial therapeutic relevance and warrant further investigations, which may provide reasons why drugs often have anomalous pharmacokinetic behavior and disproportionate dose-response relationships in certain patient populations.

  5. Xanthine oxidase-generated hydrogen peroxide is a consequence, not a mediator of cell death.

    PubMed

    Czupryna, Julie; Tsourkas, Andrew

    2012-03-01

    Oxidative stress has been associated with a wide range of diseases including atherosclerosis, cancer and Alzheimer's disease. When present in excessive concentrations, reactive oxygen species (ROS) can cause deleterious effects. This has led to the notion that the anticancer effects of various chemotherapeutics may be mediated, at least in part, by an increase in ROS. To investigate the role of xanthine oxidase (XO), a source of hydrogen peroxide, in cell death, MCF7, HeLa and 293T cells were treated with various cell-death-inducing drugs in the presence and absence of allopurinol, a specific inhibitor of XO. In the absence of allopurinol, each drug led to a time- and concentration-dependent increase in percent DNA fragmentation and ROS levels, regardless of the mechanism of cell death incurred, i.e. caspase dependent and caspase independent. By contrast, pretreatment with allopurinol led to dramatically lower ROS levels in all cases, suggesting that XO is a major contributor to oxidative stress. However, allopurinol did not exhibit a protective effect against cell death. Similarly, the administration of siRNA against XO also did not exhibit a protective effect against cell death. The level of oxidative stress was recorded using the ROS sensor CM-H(2) DCFDA and a ratiometric bioluminescent assay that takes advantage of the increased sensitivity of Firefly luciferase to hydrogen peroxide, compared with a stable variant of Renilla luciferase (RLuc), RLuc8. Overall, these findings suggest that XO-generated hydrogen peroxide, and perhaps hydrogen peroxide in general, is a consequence, but not a mediator of cell death.

  6. Effectiveness of treatment with carbamide peroxide and hydrogen peroxide in subjects affected by dental fluorosis: a clinical trial.

    PubMed

    Loyola-Rodriguez, Juan Pablo; Pozos-Guillen, Amaury de Jesus; Hernandez-Hernandez, Felipe; Berumen-Maldonado, Rocio; Patiño-Marin, Nuria

    2003-01-01

    Dental fluorosis is an endemic dental health problem around the world; so, it is important to develop clinical alternatives that are non-invasive and inexpensive. In this study, nightguard vital bleaching technique (NVBT), using carbamide and hydrogen peroxide as active agents, has shown itself to be effective in whitening teeth affected by dental fluorosis. Carbamide peroxide at 10 and 20% and hydrogen peroxide at 7.5% showed good clinical effectiveness in improving clinical appearence, but it is important to point out that clinical success is only in cases of class 1 to 3 of the Tooth Surface Index of Fluorosis. When comparing 10 and 20% concentrations of carbamide peroxide, there was no difference in the clinical effectiveness (p > 0.05); but when comparing both concentrations of carbamide peroxide against hydrogen peroxide, results showed that carbamide peroxide was more effective in whitening in cases of dental fluorosis, the difference being statistically significant (p < 0.05). NVBT has two advantages: it is a non-invasive technique and the relationship cost/benefit is excellent; only a few patients reported tenderness or mild tooth sensitivity.

  7. 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

  8. 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.

  9. [Role of catalase and superoxide dismutase in the yeast Saccharomyces cerevisiae response to hydrogen peroxide in exponential phase of growth].

    PubMed

    Baĭliak, M M; Semchyshyn, H M; Lushchak, V I

    2006-01-01

    The role of catalase and superoxide dismutase (SOD) in response of the yeast Saccharomyces cerevisiae to oxidative stress induced by hydrogen peroxide in the middle-exponential phase has been investigated. It was shown that cell survival is significantly decreased after yeast exposure to hydrogen peroxide in the strains defective in cytosolic or peroxisomal catalases. Treatment of the wild-type cells with 0.5 mM H2O2 for 30 min causes an increase in the activity of catalase and superoxide dismutase, but the effect was not observed in all strains investigated. It was also shown that hydrogen peroxide leads to an increase in the activities of both catalases and Cu,Zn-containing SOD. The effect was cancelled by cycloheximide, an inhibitor of protein synthesis.

  10. 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.

  11. 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.

  12. 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…

  13. An Experimental Investigation of Hypergolic Ignition Delay of Hydrogen Peroxide with Fuel Mixtures