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Sample records for peroxidation product 4-hydroxynonenal

  1. Modulation of keratinocyte expression of antioxidants by 4-hydroxynonenal, a lipid peroxidation end product

    SciTech Connect

    Zheng, Ruijin; Heck, Diane E.; Mishin, Vladimir

    2014-03-01

    4-Hydroxynonenal (4-HNE) is a lipid peroxidation end product generated in response to oxidative stress in the skin. Keratinocytes contain an array of antioxidant enzymes which protect against oxidative stress. In these studies, we characterized 4-HNE-induced changes in antioxidant expression in mouse keratinocytes. Treatment of primary mouse keratinocytes and PAM 212 keratinocytes with 4-HNE increased mRNA expression for heme oxygenase-1 (HO-1), catalase, NADPH:quinone oxidoreductase (NQO1) and glutathione S-transferase (GST) A1-2, GSTA3 and GSTA4. In both cell types, HO-1 was the most sensitive, increasing 86–98 fold within 6 h. Further characterization of the effects of 4-HNE on HO-1 demonstrated concentration- and time-dependentmore » increases in mRNA and protein expression which were maximum after 6 h with 30 μM. 4-HNE stimulated keratinocyte Erk1/2, JNK and p38 MAP kinases, as well as PI3 kinase. Inhibition of these enzymes suppressed 4-HNE-induced HO-1 mRNA and protein expression. 4-HNE also activated Nrf2 by inducing its translocation to the nucleus. 4-HNE was markedly less effective in inducing HO-1 mRNA and protein in keratinocytes from Nrf2 −/− mice, when compared to wild type mice, indicating that Nrf2 also regulates 4-HNE-induced signaling. Western blot analysis of caveolar membrane fractions isolated by sucrose density centrifugation demonstrated that 4-HNE-induced HO-1 is localized in keratinocyte caveolae. Treatment of the cells with methyl-β-cyclodextrin, which disrupts caveolar structure, suppressed 4-HNE-induced HO-1. These findings indicate that 4-HNE modulates expression of antioxidant enzymes in keratinocytes, and that this can occur by different mechanisms. Changes in expression of keratinocyte antioxidants may be important in protecting the skin from oxidative stress. - Highlights: • Lipid peroxidation generates 4-hydroxynonenal, a reactive aldehyde. • 4-HNE induces antioxidant proteins in mouse keratinocytes. • Induction of

  2. Modulation of keratinocyte expression of antioxidants by 4-hydroxynonenal, a lipid peroxidation end product

    SciTech Connect

    Zheng, Ruijin; Heck, Diane E.; Mishin, Vladimir; Black, Adrienne T.; Shakarjian, Michael P.; Kong, Ah-Ng Tony; Laskin, Debra L.; Laskin, Jeffrey D.

    2014-03-01

    4-Hydroxynonenal (4-HNE) is a lipid peroxidation end product generated in response to oxidative stress in the skin. Keratinocytes contain an array of antioxidant enzymes which protect against oxidative stress. In these studies, we characterized 4-HNE-induced changes in antioxidant expression in mouse keratinocytes. Treatment of primary mouse keratinocytes and PAM 212 keratinocytes with 4-HNE increased mRNA expression for heme oxygenase-1 (HO-1), catalase, NADPH:quinone oxidoreductase (NQO1) and glutathione S-transferase (GST) A1-2, GSTA3 and GSTA4. In both cell types, HO-1 was the most sensitive, increasing 86–98 fold within 6 h. Further characterization of the effects of 4-HNE on HO-1 demonstrated concentration- and time-dependent increases in mRNA and protein expression which were maximum after 6 h with 30 μM. 4-HNE stimulated keratinocyte Erk1/2, JNK and p38 MAP kinases, as well as PI3 kinase. Inhibition of these enzymes suppressed 4-HNE-induced HO-1 mRNA and protein expression. 4-HNE also activated Nrf2 by inducing its translocation to the nucleus. 4-HNE was markedly less effective in inducing HO-1 mRNA and protein in keratinocytes from Nrf2 −/− mice, when compared to wild type mice, indicating that Nrf2 also regulates 4-HNE-induced signaling. Western blot analysis of caveolar membrane fractions isolated by sucrose density centrifugation demonstrated that 4-HNE-induced HO-1 is localized in keratinocyte caveolae. Treatment of the cells with methyl-β-cyclodextrin, which disrupts caveolar structure, suppressed 4-HNE-induced HO-1. These findings indicate that 4-HNE modulates expression of antioxidant enzymes in keratinocytes, and that this can occur by different mechanisms. Changes in expression of keratinocyte antioxidants may be important in protecting the skin from oxidative stress. - Highlights: • Lipid peroxidation generates 4-hydroxynonenal, a reactive aldehyde. • 4-HNE induces antioxidant proteins in mouse keratinocytes. • Induction of

  3. Intercellular transfer of pathogenic α-synuclein by extracellular vesicles is induced by the lipid peroxidation product 4-hydroxynonenal.

    PubMed

    Zhang, Shi; Eitan, Erez; Wu, Tsung-Yu; Mattson, Mark P

    2018-01-01

    Parkinson's disease (PD) is characterized by accumulations of toxic α-synuclein aggregates in vulnerable neuronal populations in the brainstem, midbrain, and cerebral cortex. Recent findings suggest that α-synuclein pathology can be propagated transneuronally, but the underlying molecular mechanisms are unknown. Advances in the genetics of rare early-onset familial PD indicate that increased production and/or reduced autophagic clearance of α-synuclein can cause PD. The cause of the most common late-onset PD is unclear, but may involve metabolic compromise and oxidative stress upstream of α-synuclein accumulation. As evidence, the lipid peroxidation product 4-hydroxynonenal (HNE) is elevated in the brain during normal aging and moreso in brain regions afflicted with α-synuclein pathology. Here, we report that HNE increases aggregation of endogenous α-synuclein in primary neurons and triggers the secretion of extracellular vesicles (EVs) containing cytotoxic oligomeric α-synuclein species. EVs released from HNE-treated neurons are internalized by healthy neurons which as a consequence degenerate. Levels of endogenously generated HNE are elevated in cultured cells overexpressing human α-synuclein, and EVs released from those cells are toxic to neurons. The EV-associated α-synuclein is located both inside the vesicles and on their surface, where it plays a role in EV internalization by neurons. On internalization, EVs harboring pathogenic α-synuclein are transported both anterogradely and retrogradely within axons. Focal injection of EVs containing α-synuclein into the striatum of wild-type mice results in spread of synuclein pathology to anatomically connected brain regions. Our findings suggest a scenario for late-onset PD in which lipid peroxidation promotes intracellular accumulation and then extrusion of EVs containing toxic α-synuclein species; the EVs are then internalized by adjacent neurons, so propagating the neurodegenerative process. Published

  4. Early involvement of lysosome dysfunction in the degeneration of cerebral cortical neurons caused by the lipid peroxidation product 4-hydroxynonenal.

    PubMed

    Zhang, Shi; Eitan, Erez; Mattson, Mark P

    2017-03-01

    Free radical-mediated oxidative damage to proteins, lipids, and DNA occurs in neurons during acute brain injuries and in neurodegenerative disorders. Membrane lipid peroxidation contributes to neuronal dysfunction and death, in part by disrupting neuronal ion homeostasis and cellular bioenergetics. Emerging findings suggest that 4-hydroxynonenal (HNE), an aldehyde produced during lipid peroxidation, impairs the function of various proteins involved in neuronal homeostasis. Here we tested the hypothesis that HNE impairs the cellular system that removes damaged proteins and organelles, the autophagy-lysosome pathway in rat primary cortical neurons. We found that HNE, at a concentration that causes apoptosis over a 48-72 h period, increases protein levels of LC3 II and p62 and within 1 and 4 h of exposure, respectively; LC3 II and p62 immunoreactive puncta were observed in the cytoplasm of HNE-treated neurons at 6 h. The extent of up-regulation of p62 and LC3 II in response to HNE was not affected by co-treatment with the lysosome inhibitor bafilomycin A1, suggesting that the effects of HNE on autophagy were secondary to lysosome inhibition. Indeed, we found that neurons exposed to HNE exhibit elevated pH levels, and decreased protein substrate hydrolysis and cathepsin B activity. Neurons exposed to HNE also exhibited the accumulation of K63-linked polyubiquitinated proteins, which are substrates targeted for lysosomal degradation. Moreover, we found that the levels of LAMP2a and constitutively active heat-shock protein 70, and numbers of LAMP2a-positive lysosomes, are decreased in neurons exposed to HNE. Our findings demonstrate that the lipid peroxidation product HNE causes early impairment of lysosomes which may contribute to the accumulation of damaged and dysfunctional proteins and organelles and consequent neuronal death. Because impaired lysosome function is increasingly recognized as an early event in the neuronal death that occurs in neurodegenerative

  5. Role of lipid peroxidation derived 4-hydroxynonenal (4-HNE) in cancer: focusing on mitochondria.

    PubMed

    Zhong, Huiqin; Yin, Huiyong

    2015-01-01

    Oxidative stress-induced lipid peroxidation has been associated with human physiology and diseases including cancer. Overwhelming data suggest that reactive lipid mediators generated from this process, such as 4-hydroxynonenal (4-HNE), are biomarkers for oxidative stress and important players for mediating a number of signaling pathways. The biological effects of 4-HNE are primarily due to covalent modification of important biomolecules including proteins, DNA, and phospholipids containing amino group. In this review, we summarize recent progress on the role of 4-HNE in pathogenesis of cancer and focus on the involvement of mitochondria: generation of 4-HNE from oxidation of mitochondria-specific phospholipid cardiolipin; covalent modification of mitochondrial proteins, lipids, and DNA; potential therapeutic strategies for targeting mitochondrial ROS generation, lipid peroxidation, and 4-HNE. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  6. Structure−Activity Analysis of Diffusible Lipid Electrophiles Associated with Phospholipid Peroxidation: 4-Hydroxynonenal and 4-Oxononenal Analogues

    PubMed Central

    2011-01-01

    Electrophile-mediated disruption of cell signal-ing is involved in the pathogenesis of several diseases including atherosclerosis and cancer. Diffusible and membrane bound lipid electrophiles are known to modify DNA and protein substrates and modulate cellular pathways including ER stress, antioxidant response, DNA damage, heat shock, and apoptosis. Herein we report on a structure−activity relationship for several electrophilic analogues of 4-hydroxynonenal (HNE) and 4-oxononenal (ONE) with regard to toxicity and anti-inflammatory activity. The analogues studied were the oxidation products of HNE and ONE, HNEA/ONEA, the in vivo hydrolysis products of oxidized phosphatidylcholine, COOH-HNE/COOH-ONE, and their methyl esters, COOMe-HNE/ONE. The reactivity of each compound toward N-acetylcysteine was determined and compared to the toxicity toward a human colorectal carcinoma cell line (RKO) and a human monocytic leukemia cell line (THP-1). Further analysis was performed in differentiated THP-1 macrophages to assess changes in macrophage activation and pro-inflammatory signaling in response to each lipid electrophile. HNE/ONE analogues inhibited THP-1 macrophage production of the pro-inflammatory cytokines, IL-6, IL-1β, and TNFα, after lipopolysaccharide (LPS)/IFNγ activation. Inhibition of cytokine production was observed at submicromolar concentrations of several analogues with as little as 30 min of exposure. Phagocytosis of fluorescent beads was also inhibited by lipid electrophile treatment. Lipid electrophiles related to HNE/ONE are both toxic and anti-inflammatory, but the anti-inflammatory effects in human macrophages are observed at nontoxic concentrations. Neither toxicity nor anti-inflammatory activity are strongly correlated to the reactivity of the model nucleophile, N-acetylcysteine. PMID:21291287

  7. Differential metabolism of 4-hydroxynonenal in liver, lung and brain of mice and rats

    SciTech Connect

    Zheng, Ruijin; Dragomir, Ana-Cristina; Mishin, Vladimir

    2014-08-15

    The lipid peroxidation end-product 4-hydroxynonenal (4-HNE) is generated in tissues during oxidative stress. As a reactive aldehyde, it forms Michael adducts with nucleophiles, a process that disrupts cellular functioning. Liver, lung and brain are highly sensitive to xenobiotic-induced oxidative stress and readily generate 4-HNE. In the present studies, we compared 4-HNE metabolism in these tissues, a process that protects against tissue injury. 4-HNE was degraded slowly in total homogenates and S9 fractions of mouse liver, lung and brain. In liver, but not lung or brain, NAD(P)+ and NAD(P)H markedly stimulated 4-HNE metabolism. Similar results were observed in rat S9 fractionsmore » from these tissues. In liver, lung and brain S9 fractions, 4-HNE formed protein adducts. When NADH was used to stimulate 4-HNE metabolism, the formation of protein adducts was suppressed in liver, but not lung or brain. In both mouse and rat tissues, 4-HNE was also metabolized by glutathione S-transferases. The greatest activity was noted in livers of mice and in lungs of rats; relatively low glutathione S-transferase activity was detected in brain. In mouse hepatocytes, 4-HNE was rapidly taken up and metabolized. Simultaneously, 4-HNE-protein adducts were formed, suggesting that 4-HNE metabolism in intact cells does not prevent protein modifications. These data demonstrate that, in contrast to liver, lung and brain have a limited capacity to metabolize 4-HNE. The persistence of 4-HNE in these tissues may increase the likelihood of tissue injury during oxidative stress. - Highlights: • Lipid peroxidation generates 4-hydroxynonenal, a highly reactive aldehyde. • Rodent liver, but not lung or brain, is efficient in degrading 4-hydroxynonenal. • 4-hydroxynonenal persists in tissues with low metabolism, causing tissue damage.« less

  8. Differential metabolism of 4-hydroxynonenal in liver, lung and brain of mice and rats

    SciTech Connect

    Zheng, Ruijin; Dragomir, Ana-Cristina; Mishin, Vladimir; Richardson, Jason R.; Heck, Diane E.; Laskin, Debra L.; Laskin, Jeffrey D.

    2014-08-15

    The lipid peroxidation end-product 4-hydroxynonenal (4-HNE) is generated in tissues during oxidative stress. As a reactive aldehyde, it forms Michael adducts with nucleophiles, a process that disrupts cellular functioning. Liver, lung and brain are highly sensitive to xenobiotic-induced oxidative stress and readily generate 4-HNE. In the present studies, we compared 4-HNE metabolism in these tissues, a process that protects against tissue injury. 4-HNE was degraded slowly in total homogenates and S9 fractions of mouse liver, lung and brain. In liver, but not lung or brain, NAD(P)+ and NAD(P)H markedly stimulated 4-HNE metabolism. Similar results were observed in rat S9 fractions from these tissues. In liver, lung and brain S9 fractions, 4-HNE formed protein adducts. When NADH was used to stimulate 4-HNE metabolism, the formation of protein adducts was suppressed in liver, but not lung or brain. In both mouse and rat tissues, 4-HNE was also metabolized by glutathione S-transferases. The greatest activity was noted in livers of mice and in lungs of rats; relatively low glutathione S-transferase activity was detected in brain. In mouse hepatocytes, 4-HNE was rapidly taken up and metabolized. Simultaneously, 4-HNE-protein adducts were formed, suggesting that 4-HNE metabolism in intact cells does not prevent protein modifications. These data demonstrate that, in contrast to liver, lung and brain have a limited capacity to metabolize 4-HNE. The persistence of 4-HNE in these tissues may increase the likelihood of tissue injury during oxidative stress. - Highlights: • Lipid peroxidation generates 4-hydroxynonenal, a highly reactive aldehyde. • Rodent liver, but not lung or brain, is efficient in degrading 4-hydroxynonenal. • 4-hydroxynonenal persists in tissues with low metabolism, causing tissue damage.

  9. Positron emission tomography-computed tomography and 4-hydroxynonenal-histidine immunohistochemistry reveal differential onset of lipid peroxidation in primary lung cancer and in pulmonary metastasis of remote malignancies.

    PubMed

    Živković, Nevenka Piskač; Petrovečki, Mladen; Lončarić, Čedna Tomasović; Nikolić, Igor; Waeg, Georg; Jaganjac, Morana; Žarković, Kamelija; Žarković, Neven

    2017-04-01

    The Aim of the study was to reveal if PET-CT analysis of primary and of secondary lung cancer could be related to the onset of lipid peroxidation in cancer and in surrounding non-malignant lung tissue. Nineteen patients with primary lung cancer and seventeen patients with pulmonary metastasis were involved in the study. Their lungs were analyzed by PET-CT scanning before radical surgical removal of the cancer. Specific immunohistochemistry for the major bioactive marker of lipid peroxidation, 4-hydroxynonenal (HNE), was done for the malignant and surrounding non-malignant lung tissue using genuine monoclonal antibody specific for the HNE-histidine adducts. Both the intensity of the PET-CT analysis and the HNE-immunohistochemistry were in correlation with the size of the tumors analyzed, while primary lung carcinomas were larger than the metastatic tumors. The intensity of the HNE-immunohistochemistry in the surrounding lung tissue was more pronounced in the metastatic than in the primary tumors, but it was negatively correlated with the cancer volume determined by PET-CT. The appearance of HNE was more pronounced in non-malignant surrounding tissue than in cancer or stromal cells, both in case of primary and metastatic tumors. Both PET-CT and HNE-immunohistochemistry reflect the size of the malignant tissue. However, lipid peroxidation of non-malignant lung tissue in the vicinity of cancer is more pronounced in metastatic than in primary malignancies and might represent the mechanism of defense against cancer, as was recently revealed also in case of human liver cancer. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  10. 4-Hydroxynonenal induces a DNA-binding protein similar to the heat-shock factor.

    PubMed Central

    Cajone, F; Salina, M; Benelli-Zazzera, A

    1989-01-01

    By using a gel mobility assay, we have shown that treatment of HeLa cells with 4-hydroxynonenal, a major product of the peroxidation of membrane lipids and an inducer of heat-shock proteins, has the same effect as heat shock in causing the appearance of a protein which binds to the sequence of DNA specific for the induction of heat-shock genes. Lipoperoxidation and heat exposure seem to share a common mechanism of specific gene activation. Images Fig. 1. Fig. 2. PMID:2590181

  11. Role of 4-hydroxynonenal in chemopreventive activities of sulforaphane

    PubMed Central

    Sharma, Rajendra; Sharma, Abha; Chaudhary, Pankaj; Sahu, Mukesh; Jaiswal, Shailesh; Awasthi, Sanjay; Awasthi, Yogesh C.

    2012-01-01

    Chemoprevention of cancer via herbal and dietary supplements is a logical approach to combat cancer and presently it is an attractive area of research investigations. Over the years, the use of isothiocyanates, such as sulforaphane (SFN) found in cruciferous vegetables, has been advocated as chemopreventive agents and their efficacy has been demonstrated in cell lines and animal models. In-vivo studies with SFN suggest that besides protecting normal healthy cells from environmental carcinogens it also exhibits cytotoxicity and apoptotic effects against various cancer cell types. Among several mechanisms for the chemopreventive activity of SFN against chemical carcinogenesis, its effect on drug metabolizing enzymes that causes activation/ neutralization of carcinogenic metabolites is well established. Recent studies suggest that SFN exerts its selective cytotoxicity to cancer cells via reactive oxygen species (ROS)-mediated generation of lipid peroxidation (LPO) products particularly 4-hydroxynonenal (HNE). Against the background of the known biochemical effects of SFN on normal and cancer cells, in this article we have reviewed the underlying molecular mechanisms responsible for the overall chemopreventive effects of SFN focusing on the role of HNE in these mechanisms that may also contribute to its selective cytotoxicity to cancer cells. PMID:22579574

  12. Reactive species and mitochondrial dysfunction: mechanistic significance of 4-hydroxynonenal.

    PubMed

    Roede, James R; Jones, Dean P

    2010-06-01

    Mitochondrial dysfunction is a global term used in the context of "unhealthy" mitochondria. In practical terms, mitochondria are extremely complex and highly adaptive in structure, chemical and enzymatic composition, subcellular distribution and functional interaction with other components of cells. Consequently, altered mitochondrial properties that are used in experimental studies as measures of mitochondrial dysfunction often provide little or no distinction between adaptive and maladaptive changes. This is especially a problem in terms of generation of oxidant species by mitochondria, wherein increased generation of superoxide anion radical (O(2*)(-)) or hydrogen peroxide (H(2)O(2)) is often considered synonymously with mitochondrial dysfunction. However, these oxidative species are signaling molecules in normal physiology so that a change in production or abundance is not a good criterion for mitochondrial dysfunction. In this review, we consider generation of reactive electrophiles and consequent modification of mitochondrial proteins as a means to define mitochondrial dysfunction. Accumulated evidence indicates that 4-hydroxynonenal (HNE) modification of proteins reflects mitochondrial dysfunction and provides an operational criterion for experimental definition of mitochondrial dysfunction. Improved means to detect and quantify mitochondrial HNE-protein adduct formation could allow its use for environmental healthrisk assessment. Furthermore, application of improved mass spectrometry-based proteomic methods will lead to further understanding of the critical targets contributing to disease risk.

  13. 4-Hydroxynonenal inhibits interleukin-1 beta converting enzyme.

    PubMed

    Davis, D W; Hamilton, R F; Holian, A

    1997-04-01

    Lipid peroxidation results from the interaction of reactive oxygen species and polyunsaturated fatty acids. Metabolites generated from oxidative stress play an important role in the pathogenesis of a variety of diseases and biologic processes. One such product generated from lipid peroxidation in 4-hydroxynonenal (HNE). HNE is thiol reactive and exhibits numerous cellular effects. In this study, the inhibition of the cysteine protease, interleukin-1 beta (IL-1 beta) converting enzyme (ICE), by HNE in human blood mononuclear cells was investigated. HNE blocked the release of lipopolysaccharide (LPS)-stimulated IL-1 beta (EC50 5 microM) and IL-10 (EC50 2 microM) in a dose-dependent manner and, to a lesser extent, tumor necrosis factor-alpha (TNF-alpha) (EC50 15 microM) release. However, LPS-stimulated elevation of intracellular proIL-1 beta levels was not affected by HNE treatment. HNE inhibited ICE activity in lysed cells in a similar dose-dependent manner, measured by hydrolysis of the fluorogenic substrate YVAD-AMC and recombinant proIL-1 beta. To confirm that the inhibition of ICE activity by HNE was not an indirect effect, ICE activity was examined using purified recombinant human ICE (rHu-ICE). HNE inhibited rHu-ICE activity in a dose-dependent manner. Thus, low levels of HNE can suppress mononuclear cell release of IL-1 beta, probably by interacting with the active site cysteine of ICE. These results have implications for modulating mononuclear cell function during oxidative stress conditions.

  14. Yeast aquaporin regulation by 4-hydroxynonenal is implicated in oxidative stress response.

    PubMed

    Rodrigues, Claudia; Tartaro Bujak, Ivana; Mihaljević, Branka; Soveral, Graça; Cipak Gasparovic, Ana

    2017-05-01

    Reactive oxygen species, especially hydrogen peroxide (H 2 O 2 ), contribute to functional molecular impairment and cellular damage, but also are necessary in normal cellular metabolism, and in low doses play stimulatory role in cell proliferation and stress resistance. In parallel, reactive aldehydes such as 4-hydroxynonenal (HNE), are lipid peroxidation breakdown products which also contribute to regulation of numerous cellular processes. Recently, channeling of H 2 O 2 by some mammalian aquaporin isoforms has been reported and suggested to contribute to aquaporin involvement in cancer malignancies, although the mechanism by which these membrane water channels are implicated in oxidative stress is not clear. In this study, two yeast models with increased levels of membrane polyunsaturated fatty acids (PUFAs) and aquaporin AQY1 overexpression, respectively, were used to evaluate their interplay in cell's oxidative status. In particular, the aim of the study was to investigate if HNE accumulation could affect aquaporin function with an outcome in oxidative stress response. The data showed that induction of aquaporin expression by PUFAs results in increased water permeability in yeast membranes and that AQY1 activity is impaired by HNE. Moreover, AQY1 expression increases cellular sensitivity to oxidative stress by facilitating H 2 O 2 influx. On the other hand, AQY1 expression has no influence on the cellular antioxidant GSH levels and catalase activity. These results strongly suggest that aquaporins are important players in oxidative stress response and could contribute to regulation of cellular processes by regulation of H 2 O 2 influx. © 2017 IUBMB Life, 69(5):355-362, 2017. © 2017 International Union of Biochemistry and Molecular Biology.

  15. Inhibition of arachidonate 15-lipoxygenase prevents 4-hydroxynonenal-induced protein damage in male germ cells.

    PubMed

    Bromfield, Elizabeth G; Mihalas, Bettina P; Dun, Matthew D; Aitken, R John; McLaughlin, Eileen A; Walters, Jessica L H; Nixon, Brett

    2017-03-01

    Lipid peroxidation products, such as 4-hydroxynonenal (4HNE), are causative agents responsible for extensive protein damage within the male and female germlines. Recently, we have demonstrated that 4HNE production can initiate the proteolytic degradation of the molecular chaperone Heat Shock Protein A2 (HSPA2) in male germ cells. These events may be partially responsible for HSPA2 deficiency in the spermatozoa of patients that repeatedly fail in vitro fertilization. Given this, mechanisms that limit the production of 4HNE will be highly advantageous for the preservation of male fertility. The propagation of 4HNE in somatic cells has been linked to the enzymatic actions of arachidonate 15-lipoxygenase (ALOX15), a member of the lipoxygenase family of proteins. In view of this association, this study sought to explore ALOX15 as a physiological target to manipulate the levels of 4HNE produced in the male germline. Herein, we have demonstrated that ALOX15 is markedly upregulated in response to oxidative stress in round spermatids and the GC-2 cell line. Pharmacological inhibition of ALOX15 in GC-2 cells resulted in a significant reduction in both mitochondrial and cytoplasmic reactive oxygen species, as well as a dramatic reduction in 4HNE. Importantly, the reduced bioavailability of this aldehyde appears to confer positive downstream effects to its target proteins such that HSPA2 could be protected from damage by 4HNE. Taken together, these results suggest that the actions of ALOX15 are intimately tied to the production of 4HNE. Thus, the ALOX15 protein may be a promising new target for the mitigation of germline oxidative stress. © The Authors 2017. Published by Oxford University Press on behalf of Society for the Study of Reproduction. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. New evidence implicating 4-hydroxynonenal in the pathogenesis of osteoarthritis in vivo.

    PubMed

    Shi, Qin; Abusarah, Jamilah; Zaouter, Charlotte; Moldovan, Florina; Fernandes, Julio C; Fahmi, Hassan; Benderdour, Mohamed

    2014-09-01

    To demonstrate the involvement of 4-hydroxynonenal (HNE), a very reactive aldehyde derived from lipid peroxidation, in the pathogenesis of osteoarthritis (OA) in vivo. In the first experimental protocol, OA was induced by anterior cruciate ligament transection (ACLT) of the right knees of crossbred dogs (n = 6 per group). The animals were treated with placebo or HNE-trapping carnosine (5 or 20 mg/kg/day) orally for 8 weeks. Another group of dogs was treated for 4 weeks with 20 mg/kg/day of carnosine starting 4 weeks after surgery. Sham-operated dogs served as controls. In the second experimental protocol, a pathophysiologic dose of HNE (80 nmoles/ml) or vehicle was injected weekly into the right knee joints of crossbred dogs (n = 6 per group) for 8 weeks. Articular cartilage was subjected to macroscopic, histomorphologic, and immunohistochemical analyses. Cartilage-degrading enzymes and oxidative stress-related products were assessed in synovial fluid and cartilage explants. Markers of inflammation were evaluated in synovium and synovial fluid. In dogs that had undergone ACLT, carnosine treatment reduced the severity and histopathology score of OA cartilage lesions and also decreased HNE-protein adducts, pentosidine, nitrosylated proteins, cartilage-degrading enzymes, and markers of inflammation. Intraarticular injection of HNE induced cartilage lesions, as assessed by macroscopic and microscopic criteria. Cartilage-degrading enzymes and markers of inflammation increased in HNE-treated dogs. This is the first in vivo study to demonstrate the pathophysiologic role of HNE in OA. That carnosine abolishes HNE production and a number of factors known to be involved in OA pathogenesis renders it a clinically valuable agent in prevention of the disease. Copyright © 2014 by the American College of Rheumatology.

  17. Pathophysiology of mitochondrial lipid oxidation: Role of 4-hydroxynonenal (4-HNE) and other bioactive lipids in mitochondria.

    PubMed

    Xiao, Mengqing; Zhong, Huiqin; Xia, Lin; Tao, Yongzhen; Yin, Huiyong

    2017-10-01

    Mitochondrial lipids are essential for maintaining the integrity of mitochondrial membranes and the proper functions of mitochondria. As the "powerhouse" of a cell, mitochondria are also the major cellular source of reactive oxygen species (ROS). Oxidative stress occurs when the antioxidant system is overwhelmed by overproduction of ROS. Polyunsaturated fatty acids in mitochondrial membranes are primary targets for ROS attack, which may lead to lipid peroxidation (LPO) and generation of reactive lipids, such as 4-hydroxynonenal. When mitochondrial lipids are oxidized, the integrity and function of mitochondria may be compromised and this may eventually lead to mitochondrial dysfunction, which has been associated with many human diseases including cancer, cardiovascular diseases, diabetes, and neurodegenerative diseases. How mitochondrial lipids are oxidized and the underlying molecular mechanisms and pathophysiological consequences associated with mitochondrial LPO remain poorly defined. Oxidation of the mitochondria-specific phospholipid cardiolipin and generation of bioactive lipids through mitochondrial LPO has been increasingly recognized as an important event orchestrating apoptosis, metabolic reprogramming of energy production, mitophagy, and immune responses. In this review, we focus on the current understanding of how mitochondrial LPO and generation of bioactive lipid mediators in mitochondria are involved in the modulation of mitochondrial functions in the context of relevant human diseases associated with oxidative stress. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Malondialdehyde and 4-hydroxynonenal protein adducts in plasma and liver of rats with iron overload.

    PubMed Central

    Houglum, K; Filip, M; Witztum, J L; Chojkier, M

    1990-01-01

    In hepatic iron overload, iron-catalyzed lipid peroxidation has been implicated in the mechanisms of hepatocellular injury. Lipid peroxidation may produce reactive aldehydes such as malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE), which may form aldehyde-protein adducts. We investigated whether lipid peroxidation occurred in rats fed a diet containing 3% carbonyl iron for 5-13 wk, and if this resulted in the formation of MDA- and 4-HNE- protein adducts. Chronic iron feeding resulted in hepatic iron overload (greater than 10-fold) and concomitantly induced a 2-fold increase in hepatic lipid peroxidation. Using an antiserum specific for MDA-lysine protein adducts, we demonstrated by immunohistochemistry the presence of aldehyde-protein adducts in the cytosol of periportal hepatocytes, which co-localized with iron. In addition, MDA- and 4-HNE-lysine adducts were found in plasma proteins of animals with iron overload. Only MDA adducts were detected in albumin, while other plasma proteins including a approximately 120-kD protein had both MDA and 4-HNE adducts. In this animal model of hepatic iron overload, injury occurs primarily in periportal hepatocytes, where MDA-lysine protein adducts and excess iron co-localized. Images PMID:2123889

  19. Lipid peroxidation products as potential bioindicators of Lyme arthritis.

    PubMed

    Łuczaj, W; Moniuszko, A; Rusak, M; Pancewicz, S; Zajkowska, J; Skrzydlewska, E

    2011-03-01

    Lipid peroxidation products, malondialdehyde (MDA), 4-hydroxynonenal (4-HNE) and [Formula: see text], were determined in the plasma and urine of patients with Lyme arthritis and healthy people. The group consisted of 19 patients with Lyme arthritis (mean age 47 years) and the control group consisted of 16 healthy individuals (mean age 38 years). Diagnosis of Lyme disease was confirmed by epidemiological anamnesis, clinical manifestation of arthritis and serological examinations. Lipid peroxidation was estimated by the measurement of aldehydes (MDA and 4-HNE, determined by high-performance liquid chromatography [HPLC]) and prostaglandin derivatives (8 - isoPGF(2a), determined by liquid chromatography/mass spectrometry [LC/MS]). MDA and 4-HNE levels were increased about 2-4-fold in the plasma, while in the urine, the increases were about 2-fold. More significant increases were noted for the 8 - isoPGF(2a) total plasma level, which was enhanced over 4-fold, and for the urine 8 - isoPGF(2a) level, which was increased over 8-fold. The 8 - isoPGF(2a) total plasma level consists of free and esterified form. During infection, the ratio of free to esterified form is significantly smaller compared to healthy people. The ratio of free to esterified form of 8 - isoPGF(2a) may be a useful indicator of Lyme arthritis. Moreover, the complementarities of three lipid peroxidation product levels may be helpful in the diagnosis of Lyme arthritis.

  20. Immunohistochemical Characterization of Hepatic Malondialdehyde and 4-Hydroxynonenal Modified Proteins During Early Stages of Ethanol-Induced Liver Injury

    PubMed Central

    Sampey, Brante P.; Korourian, Soheila; Ronis, Martin J.; Badger, Thomas M.; Petersen, Dennis R.

    2010-01-01

    Background Chronic ethanol consumption is associated with hepatic lipid peroxidation and the deposition or retention of aldehyde-adducted proteins postulated to be involved in alcohol-induced liver injury. The purpose of this study was to characterize hepatocellular formation of aldehyde-protein adducts during early stages of alcohol-induced liver injury. Methods Female Sprague Dawley® rats were subjected to the intragastric administration of a low-carbohydrate/high-fat total enteral nutrition diet or a total enteral nutrition diet containing ethanol for a period of 36 days. Indexes of hepatic responses to ethanol were evaluated in terms of changes in plasma alanine aminotransferase activity, hepatic histopathologic analysis, and induction of cytochrome P-4502E1 (CYP2E1). Immunohistochemical methods were used to detect hepatic proteins modified with malondialdehyde (MDA) or 4-hydroxynonenal (4-HNE) for subsequent quantitative image analysis. Results After 36 days of treatment, rats receiving the alcohol-containing diet displayed hepatic histopathologies characterized by marked micro- and macrosteatosis associated with only minor inflammation and necrosis. Alcohol administration resulted in a 3-fold elevation of plasma alanine aminotransferase activity and 3-fold increases (p < 0.01) in hepatic CYP2E1 apoprotein and activity. Quantitative immunohistochemical analysis revealed significant (p < 0.01) 5-fold increases in MDA- and 4-HNE modified proteins in liver sections prepared from rats treated with alcohol. The MDA- or 4-HNE modified proteins were contained in hepatocytes displaying intact morphology and were colocalized primarily with microvesicular deposits of lipid. Aldehyde-modified proteins were not prevalent in parenchymal or nonparenchymal cells associated with foci of necrosis or inflammation. Conclusions These results suggest that alcohol-induced lipid peroxidation is an early event during alcohol-mediated liver injury and may be a sensitizing event

  1. Alterations in mitochondrial respiratory functions, redox metabolism and apoptosis by oxidant 4-hydroxynonenal and antioxidants curcumin and melatonin in PC12 cells

    SciTech Connect

    Raza, Haider; John, Annie; Brown, Eric M.

    2008-01-15

    Cellular oxidative stress and alterations in redox metabolisms have been implicated in the etiology and pathology of many diseases including cancer. Antioxidant treatments have been proven beneficial in controlling these diseases. We have recently shown that 4-hydroxynonenal (4-HNE), a by-product of lipid peroxidation, induces oxidative stress in PC12 cells by compromising the mitochondrial redox metabolism. In this study, we have further investigated the deleterious effects of 4-HNE on mitochondrial respiratory functions and apoptosis using the same cell line. In addition, we have also compared the effects of two antioxidants, curcumin and melatonin, used as chemopreventive agents, on mitochondrial redox metabolismmore » and respiratory functions in these cells. 4-HNE treatment has been shown to cause a reduction in glutathione (GSH) pool, an increase in reactive oxygen species (ROS), protein carbonylation and apoptosis. A marked inhibition in the activities of the mitochondrial respiratory enzymes, cytochrome c oxidase and aconitase was observed after 4-HNE treatment. Increased nuclear translocation of NF-kB/p65 protein was also observed after 4-HNE treatment. Curcumin and melatonin treatments, on the other hand, maintained the mitochondrial redox and respiratory functions without a marked effect on ROS production and cell viability. These results suggest that 4-HNE-induced cytotoxicity may be associated, at least in part, with the altered mitochondrial redox and respiratory functions. The alterations in mitochondrial energy metabolism and redox functions may therefore be critical in determining the difference between cell death and survival.« less

  2. Metabolic Impact of 4-Hydroxynonenal on Macrophage-Like RAW 264.7 Function and Activation

    PubMed Central

    Harry, Reese S.; Hiatt, Leslie A.; Kimmel, Danielle W.; Carney, Clare K.; Halfpenny, Kristin C.; Cliffel, David E.; Wright, David W.

    2012-01-01

    Metabolic profiling of macrophage metabolic response upon exposure to 4-hydroxynonenal (HNE) demonstrates that HNE does not simply inactivate superoxide generating enzymes but could also be responsible for the impairment of downfield signaling pathways. Multianalyte microphysiometry (MAMP) was employed to simultaneously measure perturbations in extracellular acidification, lactate production and oxygen consumption for the examination of aerobic and anaerobic pathways. Combining the activation of oxidative burst with phorbol myristate acetate (PMA) and the immunosuppression with HNE, the complex nature of HNE toxicity was determined to be concentration- and time-dependent. Further analysis was utilized to assess the temporal effect of HNE on reactive oxygen species (ROS) production and on protein kinase C (PKC). Increased levels of HNE with decreasing PKC activity suggest PKC is a target for HNE adductation prior to oxidative burst. Additionally, localization of PKC to the cell membrane was prevented with the introduction of HNE, demonstrating a consequence of HNE adductation on NADPH activation. The impairment of ROS by HNE suggests HNE has a greater role in foam cell formation and tissue damage than is already known. Although work has been performed to understand the effect of HNE’s regulation of specific signaling pathways, details regarding its involvement in cellular metabolism as a whole are generally unknown. This study examines the impact of HNE on macrophage oxidative burst and identifies PKC as a key protein for HNE suppression and eventual metabolic response. PMID:22799741

  3. Malarial pigment hemozoin impairs chemotactic motility and transendothelial migration of monocytes via 4-hydroxynonenal.

    PubMed

    Skorokhod, Oleksii A; Barrera, Valentina; Heller, Regine; Carta, Franco; Turrini, Franco; Arese, Paolo; Schwarzer, Evelin

    2014-10-01

    Natural hemozoin, nHZ, is avidly phagocytosed in vivo and in vitro by human monocytes. The persistence of the undigested β-hematin core of nHZ in the phagocyte lysosome for long periods of time modifies several cellular immune functions. Here we show that nHZ phagocytosis by human primary monocytes severely impaired their chemotactic motility toward MCP-1, TNF, and FMLP, by approximately 80% each, and their diapedesis across a confluent human umbilical vein endothelial cell layer toward MCP-1 by 45±5%. No inhibition was observed with latex-fed or unfed monocytes. Microscopic inspection revealed polarization defects in nHZ-fed monocytes due to irregular actin polymerization. Phagocytosed nHZ catalyzes the peroxidation of polyunsaturated fatty acids and generation of the highly reactive derivative 4-hydroxynonenal (4-HNE). Similar to nHZ phagocytosis, the exposure of monocytes to in vivo-compatible 4-HNE concentrations inhibited cell motility in both the presence and the absence of chemotactic stimuli, suggesting severe impairment of cytoskeleton dynamics. Consequently, 4-HNE conjugates with the cytoskeleton proteins β-actin and coronin-1A were immunochemically identified in nHZ-fed monocytes and mass spectrometrically localized in domains of protein-protein interactions involved in cytoskeleton reorganization and cell motility. The molecular and functional modifications of actin and coronin by nHZ/4-HNE may also explain impaired phagocytosis, another motility-dependent process previously described in nHZ-fed monocytes. Further studies will show whether impaired monocyte motility may contribute to the immunodepression and the frequent occurrence of secondary infections observed in malaria patients. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Reduced cellular redox status induces 4-hydroxynonenal-mediated caspase 3 activation leading to erythrocyte death during chronic arsenic exposure in rats

    SciTech Connect

    Biswas, Debabrata; Sen, Gargi; Biswas, Tuli

    2010-05-01

    Chronic exposure to arsenic in rats led to gradual accumulation of the toxicant in erythrocytes causing oxidative stress in these cells. 4-Hydroxynonenal (4-HNE), a major aldehyde product of lipid peroxidation, contributed significantly to the cytopathological events observed during oxidative stress in the erythrocytes of exposed rats. 4-HNE triggered death signal cascade that was initiated with the formation of HNE-protein adducts in cytosol. HNE-protein adduct formation resulted in depletion of cytosolic antioxidants followed by increased generation of ROS. Results showed accumulation of hydrogen peroxide (H{sub 2}O{sub 2}) from the early stages of arsenic exposure, while superoxide (O{sub 2}{sup c}entre dot{sup -}) and hydroxyl radical ({sup c}entre dotOH) also contributed to the oxidative stress during longer period of exposure. Suppression of antioxidant system coupled with increased generation of ROS eventually led to activation of caspase 3 during arsenic exposure. Attenuation of HNE-mediated activation of caspase 3 in presence of N-acetylcysteine (NAC) indicated the involvement of GSH in the process. Prevention of HNE-mediated degradation of membrane proteins in presence of Z-DEVD-FMK identified caspase 3 as the principal mediator of HNE-induced cellular damage during arsenic exposure. Degradation of band 3 followed by its aggregation on the red cell surface promoted immunologic recognition of redistributed band 3 by autologous IgG with subsequent attachment of C3b. Finally, the formation of C3b-IgG-band 3 immune complex accelerated the elimination of affected cells from circulation and led to the decline of erythrocyte life span during chronic arsenic toxicity.

  5. Mitochondria as a Source and Target of Lipid Peroxidation Products in Healthy and Diseased Heart

    PubMed Central

    Anderson, Ethan J.; Katunga, Lalage A.; Willis, Monte S.

    2013-01-01

    Summary The heart is a highly oxidative organ in which cardiomyocyte turnover is virtually absent, making it particularly vulnerable to accumulation of lipid peroxidation products (LPPs) formed as a result of oxidative damage.Reactive oxygen and nitrogen species are the most common electrophiles formed during lipid peroxidation and lead to the formation of both stable and unstable lipid peroxidation products (LPPs). Of the LPPs formed, highly reactive aldehydes are a well-recognized causative factor in aging and age-associated diseases including cardiovascular disease and diabetes.Recent studies have identified that the mitochondria are both a primary source and target of LPPs, with specific emphasis on aldehydes in cardiomyocytes, and how these affect the electron transport system and Ca2+ balance.A number of studies have found that there are functional consequences in the heart as a consequence of exposure to specific aldehydes (acrolein, trans-2-hexanal, 4-hydroxynonenal, and acetaldehyde). Since these LPPs are known to form in heart failure, cardiac ischemia/reperfusion injury, and diabetes, they may have an underappreciated role in the pathophysiology of these disease processes.LPPs are involved in transcriptionally regulating endogenous anti-oxidant systems. Recent evidence has demonstrated that transient increases in LPPs might be beneficial in cardioprotection by contributing to mito-hormesis (i.e. this induction of anti-oxidant systems) in cardiomyocytes. Thus, exploitation of cardioprotective actions of LPPs may represent a novel therapeutic strategy for future treatment of heart disease. PMID:22066679

  6. 4-Hydroxynonenal induces mitochondrial oxidative stress, apoptosis and expression of glutathione S-transferase A4-4 and cytochrome P450 2E1 in PC12 cells

    SciTech Connect

    Raza, Haider; John, Annie

    2006-10-15

    An excessive and sustained increase in reactive oxygen species (ROS) production and oxidative stress have been implicated in the pathogenesis of many diseases. In the present study, we have demonstrated that 4-hydroxynonenal (4-HNE), a product of lipid peroxidation, alters glutathione (GSH) pools and induces oxidative stress in PC12 cells in culture. This increase was accompanied by alterations in subcellular ROS and glutathione (GSH) metabolisms. The GSH homeostasis was affected as both mitochondrial and extramitochondrial GSH levels, GSH peroxidase and glutathione reductase activities were inhibited and glutathione S-transferase (GST) activity was increased after 4-HNE treatment. A concentration- and time-dependent increase inmore » cytochrome P450 2E1 (CYP 2E1) activity in the mitochondria and postmitochondrial supernatant was also observed. 4-HNE-induced oxidative stress also caused an increase in the expression of GSTA4-4, CYP2E1 and Hsp70 proteins in the mitochondria. Increased oxidative stress in PC12 cells initiated apoptosis as indicated by the release of mitochondrial cytochrome c, activation of poly-(ADP-ribose) polymerase (PARP), DNA fragmentation and decreased expression of antiapoptotic Bcl-2 proteins. Mitochondrial respiratory and redox functions also appeared to be affected markedly by 4-HNE treatment. These results suggest that HNE-induced oxidative stress and apoptosis might be associated with altered mitochondrial functions and a compromised GSH metabolism and ROS clearance.« less

  7. Mitochondrial dysfunction and lipid peroxidation in rat frontal cortex by chronic NMDA administration can be partially prevented by lithium treatment.

    PubMed

    Kim, Helena K; Isaacs-Trepanier, Cameron; Elmi, Nika; Rapoport, Stanley I; Andreazza, Ana C

    2016-05-01

    Chronic N-methyl-d-aspartate (NMDA) administration to rats may be a model to investigate excitotoxicity mediated by glutamatergic hyperactivity, and lithium has been reported to be neuroprotective. We hypothesized that glutamatergic hyperactivity in chronic NMDA injected rats would cause mitochondrial dysfunction and lipid peroxidation in the brain, and that chronic lithium treatment would ameliorate some of these NMDA-induced alterations. Rats treated with lithium for 6 weeks were injected i.p. 25 mg/kg NMDA on a daily basis for the last 21 days of lithium treatment. Brain was removed and frontal cortex was analyzed. Chronic NMDA decreased brain levels of mitochondrial complex I and III, and increased levels of the lipid oxidation products, 8-isoprostane and 4-hydroxynonenal, compared with non-NMDA injected rats. Lithium treatment prevented the NMDA-induced increments in 8-isoprostane and 4-hydroxynonenal. Our findings suggest that increased chronic activation of NMDA receptors can induce alterations in electron transport chain complexes I and III and in lipid peroxidation in brain. The NMDA-induced changes may contribute to glutamate-mediated excitotoxicity, which plays a role in brain diseases such as bipolar disorder. Lithium treatment prevented changes in 8-isoprostane and 4-hydroxynonenal, which may contribute to lithium's reported neuroprotective effect and efficacy in bipolar disorder. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Chemistry and Biology of DNA Containing 1,N2-Deoxyguanosine Adducts of the α,β-Unsaturated Aldehydes Acrolein, Crotonaldehyde, and 4-Hydroxynonenal

    PubMed Central

    2009-01-01

    The α,β-unsaturated aldehydes (enals) acrolein, crotonaldehyde, and trans-4-hydroxynonenal (4-HNE) are products of endogenous lipid peroxidation, arising as a consequence of oxidative stress. The addition of enals to dG involves Michael addition of the N2-amine to give N2-(3-oxopropyl)-dG adducts, followed by reversible cyclization of N1 with the aldehyde, yielding 1,N2-dG exocyclic products. The 1,N2-dG exocyclic adducts from acrolein, crotonaldehyde, and 4-HNE exist in human and rodent DNA. The enal-induced 1,N2-dG lesions are repaired by the nucleotide excision repair pathway in both Escherichia coli and mammalian cells. Oligodeoxynucleotides containing structurally defined 1,N2-dG adducts of acrolein, crotonaldehyde, and 4-HNE were synthesized via a postsynthetic modification strategy. Site-specific mutagenesis of enal adducts has been carried out in E. coli and various mammalian cells. In all cases, the predominant mutations observed are G→T transversions, but these adducts are not strongly miscoding. When placed into duplex DNA opposite dC, the 1,N2-dG exocyclic lesions undergo ring opening to the corresponding N2-(3-oxopropyl)-dG derivatives. Significantly, this places a reactive aldehyde in the minor groove of DNA, and the adducted base possesses a modestly perturbed Watson−Crick face. Replication bypass studies in vitro indicate that DNA synthesis past the ring-opened lesions can be catalyzed by pol η, pol ι, and pol κ. It also can be accomplished by a combination of Rev1 and pol ζ acting sequentially. However, efficient nucleotide insertion opposite the 1,N2-dG ring-closed adducts can be carried out only by pol ι and Rev1, two DNA polymerases that do not rely on the Watson−Crick pairing to recognize the template base. The N2-(3-oxopropyl)-dG adducts can undergo further chemistry, forming interstrand DNA cross-links in the 5′-CpG-3′ sequence, intrastrand DNA cross-links, or DNA−protein conjugates. NMR and mass spectrometric analyses

  9. Protein-selective capture to analyze electrophile adduction of hsp90 by 4-hydroxynonenal.

    PubMed

    Connor, Rebecca E; Marnett, Lawrence J; Liebler, Daniel C

    2011-08-15

    The analysis of protein modification by electrophiles is a challenging problem. Most reported protein-electrophile adducts have been characterized from in vitro reactions or through affinity capture of the adduct moiety, which enables global analyses but is poorly suited to targeted studies of specific proteins. We employed a targeted molecular probe approach to study modifications of the molecular chaperone heat shock protein 90 (Hsp90), which regulates diverse client proteins. Noncovalent affinity capture with a biotinyl-geldanamycin probe isolated both isoforms of the native protein (Hsp90α and Hsp90β) from human RKO colorectal cancer cells. Geldanamycin-biotin capture afforded higher purity Hsp90 than did immunoprecipitation and enabled detection of endogenously phosphorylated protein by liquid chromatography-tandem mass spectrometry (LC-MS/MS). We applied this approach to map and quantify adducts formed on Hsp90 by 4-hydroxynonenal (HNE) in RKO cells. LC-MS/MS analyses of tryptic digests by identified His(450) and His(490) of Hsp90α as having a 158 Da modification, corresponding to NaBH(4)-reduced HNE adducts. Five histidine residues were also adducted on Hsp90β: His(171), His(442), His(458), His(625), and His(632). The rates of adduction at these sites were determined with Hsp90 protein in vitro and with Hsp90 in HNE-treated cells with a LC-MS/MS-based, label-free relative quantitation method. During in vitro and cell treatment with HNE, residues on Hsp90α and Hsp90β displayed adduction rates ranging from 3.0 × 10(-5) h(-1) to 1.08 ± 0.17 h(-1). Within the middle client-binding domain of Hsp90α, residue His(450) demonstrated the most rapid adduction with k(obs) of 1.08 ± 0.17 h(-1) in HNE-treated cells. The homologous residue on Hsp90β, His(442), was adducted more rapidly than the N-terminal residue, His(171), despite very similar predicted pK(a) values of both residues. The Hsp90 middle client-binding domain thus may play a signicant role in HNE

  10. Distribution and time-course of 4-hydroxynonenal, heat shock protein 110/105 family members and cyclooxygenase-2 expression in the hippocampus of rat during trimethyltin-induced neurodegeneration.

    PubMed

    Corvino, V; Marchese, E; Zarkovic, N; Zarkovic, K; Cindric, M; Waeg, G; Michetti, F; Geloso, M C

    2011-08-01

    Trimethyltin (TMT), an organotin compound considered a useful tool to obtain an experimental model of neurodegeneration, exhibits neurotoxicant effects selectively localised in the limbic system and especially in the hippocampus, which are different in the rat and in mice. In the rat hippocampus, we investigated the expression of aldehyde 4-hydroxynonenal, a major bioactive marker of membrane lipid peroxidation, heat shock protein (HSP) 110/105 family members, markers of oxidative stress, and the neuroinflammatory marker cyclooxygenase-2 after TMT-intoxication at various time points after treatment. Our data show that TMT-induced neurodegeneration in the rat hippocampus is associated specifically with oxidative stress and lipid peroxidation, but not with HSP expression, indicating species-specific differences in the neurotoxicity of TMT between rats and mice.

  11. The chemistry of cell signaling by reactive oxygen and nitrogen species and 4-hydroxynonenal

    PubMed Central

    Forman, Henry Jay; Fukuto, Jon M.; Miller, Tom; Zhang, Hongqiao; Rinna, Alessandra; Levy, Smadar

    2008-01-01

    During the past several years, major advances have been made in understanding how reactive oxygen species (ROS) and nitrogen species (RNS) participate in signal transduction. Identification of the specific targets and the chemical reactions involved still remains to be resolved with many of the signaling pathways in which the involvement of reactive species has been determined. Our understanding is that ROS and RNS have second messenger roles. While cysteine residues in the thiolate (ionized) form found in several classes of signaling proteins can be specific targets for reaction with H2O2 and RNS, better understanding of the chemistry, particularly kinetics, suggests that for many signaling events in which ROS and RNS participate, enzymatic catalysis is more likely to be involved than non-enzymatic reaction. Due to increased interest in how oxidation products, particularly lipid peroxidation products, also are involved with signaling, a review of signaling by 4-hydroxy-2-nonenal (HNE) is included. This article focuses on the chemistry of signaling by ROS, RNS, and HNE and will describe reactions with selected target proteins as representatives of the mechanisms rather attempt to comprehensively review the many signaling pathways in which the reactive species are involved. PMID:18602883

  12. [Low temperature phosphorescence of lipid peroxidation products].

    PubMed

    Mazhul', V M; Shcherbin, D G

    1998-01-01

    The phosphorescence exitation and emission spectra and the phosphorescence lifetimes of polymerized malonic aldehyde, Shiff bases, linoleic acid, phosphatidylcholine, phosphatidylethanolamine, cardiolipine, total lipid fraction from human erythrocyte membranes were measured at 77 K. The nature of chromophores of lipid peroxidation products capable of phosphorescence was discussed.

  13. Increased 4-hydroxynonenal protein adducts in male GSTA4–4/PPAR-α double knockout mice enhance injury during early stages of alcoholic liver disease

    PubMed Central

    Mercer, Kelly E.; Gannon, Brenda; Engi, Bridgette; Zimniak, Piotr; Shearn, Colin T.; Orlicky, David J.; Albano, Emanuele; Badger, Thomas M.; Petersen, Dennis R.

    2014-01-01

    To test the significance of lipid peroxidation in the development of alcoholic liver injury, an ethanol (EtOH) liquid diet was fed to male 129/SvJ mice (wild-type, WT) and glutathione S-transferase A4–4-null (GSTA4−/−) mice for 40 days. GSTA4−/− mice were crossed with peroxisome proliferator-activated receptor-α-null mice (PPAR-α−/−), and the effects of EtOH in the resulting double knockout (dKO) mice were compared with the other strains. EtOH increased lipid peroxidation in all except WT mice (P < 0.05). Increased steatosis and mRNA expression of the inflammatory markers CXCL2, tumor necrosis factor-α (TNF-α), and α-smooth muscle actin (α-SMA) were observed in EtOH GSTA4−/− compared with EtOH WT mice (P < 0.05). EtOH PPAR-α−/− mice had increased steatosis, serum alanine aminotransferase (ALT), and hepatic CD3+ T cell populations and elevated mRNA encoding CD14, CXCL2, TNF-α, IL-6, CD138, transforming growth factor-β, platelet-derived growth factor receptor-β (PDGFR-β), matrix metalloproteinase (MMP)-9, MMP-13, α-SMA, and collagen type 1 compared with EtOH WT mice. EtOH-fed dKO mice displayed elevation of periportal hepatic 4-hydroxynonenal adducts and serum antibodies against malondialdehyde adducts compared with EtOH feeding of GSTA4−/−, PPAR-α−/−, and WT mice (P < 0.05). ALT was higher in EtOH dKO mice compared with all other groups (P < 0.001). EtOH-fed dKO mice displayed elevated mRNAs for TNF-α and CD14, histological evidence of fibrosis, and increased PDGFR, MMP-9, and MMP-13 mRNAs compared with the EtOH GSTA4−/− or EtOH PPAR-α−/− genotype (P < 0.05). These findings demonstrate the central role lipid peroxidation plays in mediating progression of alcohol-induced necroinflammatory liver injury, stellate cell activation, matrix remodeling, and fibrosis. PMID:25501545

  14. Increased 4-hydroxynonenal protein adducts in male GSTA4-4/PPAR-α double knockout mice enhance injury during early stages of alcoholic liver disease.

    PubMed

    Ronis, Martin J J; Mercer, Kelly E; Gannon, Brenda; Engi, Bridgette; Zimniak, Piotr; Shearn, Colin T; Orlicky, David J; Albano, Emanuele; Badger, Thomas M; Petersen, Dennis R

    2015-03-01

    To test the significance of lipid peroxidation in the development of alcoholic liver injury, an ethanol (EtOH) liquid diet was fed to male 129/SvJ mice (wild-type, WT) and glutathione S-transferase A4-4-null (GSTA4-/-) mice for 40 days. GSTA4-/- mice were crossed with peroxisome proliferator-activated receptor-α-null mice (PPAR-α-/-), and the effects of EtOH in the resulting double knockout (dKO) mice were compared with the other strains. EtOH increased lipid peroxidation in all except WT mice (P < 0.05). Increased steatosis and mRNA expression of the inflammatory markers CXCL2, tumor necrosis factor-α (TNF-α), and α-smooth muscle actin (α-SMA) were observed in EtOH GSTA4-/- compared with EtOH WT mice (P < 0.05). EtOH PPAR-α-/- mice had increased steatosis, serum alanine aminotransferase (ALT), and hepatic CD3+ T cell populations and elevated mRNA encoding CD14, CXCL2, TNF-α, IL-6, CD138, transforming growth factor-β, platelet-derived growth factor receptor-β (PDGFR-β), matrix metalloproteinase (MMP)-9, MMP-13, α-SMA, and collagen type 1 compared with EtOH WT mice. EtOH-fed dKO mice displayed elevation of periportal hepatic 4-hydroxynonenal adducts and serum antibodies against malondialdehyde adducts compared with EtOH feeding of GSTA4-/-, PPAR-α-/-, and WT mice (P < 0.05). ALT was higher in EtOH dKO mice compared with all other groups (P < 0.001). EtOH-fed dKO mice displayed elevated mRNAs for TNF-α and CD14, histological evidence of fibrosis, and increased PDGFR, MMP-9, and MMP-13 mRNAs compared with the EtOH GSTA4-/- or EtOH PPAR-α-/- genotype (P < 0.05). These findings demonstrate the central role lipid peroxidation plays in mediating progression of alcohol-induced necroinflammatory liver injury, stellate cell activation, matrix remodeling, and fibrosis. Copyright © 2015 the American Physiological Society.

  15. Increased accumulation of 4-hydroxynonenal adducts in female GSTA4/PPAR alpha double knockout mice enhance steatosis and inflammation in a model of pediatric nonalcoholic fatty liver disease

    USDA-ARS?s Scientific Manuscript database

    Hepatocellular injury resulting from increased lipid peroxidation products and oxidative stress is considered a potential mechanism driving the progression of nonalcoholic fatty liver disease (NAFLD) to nonalcoholic steatohepatitsis (NASH). To test the significance of lipid peroxidation and protein...

  16. Increased levels of urinary biomarkers of lipid peroxidation products among workers occupationally exposed to diesel engine exhaust.

    PubMed

    Bin, Ping; Shen, Meili; Li, Haibin; Sun, Xin; Niu, Yong; Meng, Tao; Yu, Tao; Zhang, Xiao; Dai, Yufei; Gao, Weimin; Gu, Guizhen; Yu, Shanfa; Zheng, Yuxin

    2016-08-01

    Diesel engine exhaust (DEE) was found to induce lipid peroxidation (LPO) in animal exposure studies. LPO is a class of oxidative stress and can be reflected by detecting the levels of its production, such as malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE), and etheno-DNA adducts including 1,N(6)-etheno-2'-deoxyadenosine (ɛdA) and 3,N(4)-etheno-2'-deoxycytidine (ɛdC). However, the impact of DEE exposure on LPO has not been explored in humans. In this study, we evaluated urinary MDA, 4-HNE, ɛdA, and ɛdC levels as biomarkers of LPO among 108 workers with exclusive exposure to DEE and 109 non-DEE-exposed workers. Results showed that increased levels of urinary MDA and ɛdA were observed in subjects occupationally exposed to DEE before and after age, body mass index (BMI), smoking status, and alcohol use were adjusted (all p < 0.001). There was a statistically significant relationship between the internal exposure dose (urinary ΣOH-PAHs) and MDA, 4-HNE, and ɛdA (all p < 0.001). Furthermore, significant increased relations between urinary etheno-DNA adduct and MDA, 4-HNE were observed (all p < 0.05). The findings of this study suggested that the level of LPO products (MDA and ɛdA) was increased in DEE-exposed workers, and urinary MDA and ɛdA might be feasible biomarkers for DEE exposure. LPO induced DNA damage might be involved and further motivated the genomic instability could be one of the pathogeneses of cancer induced by DEE-exposure. However, additional investigations should be performed to understand these observations.

  17. FORMATION OF 4-HYDROXYNONENAL FROM CARDIOLIPIN OXIDATION: INTRAMOLECULAR PEROXYL RADICAL ADDITION AND DECOMPOSITION

    PubMed Central

    Liu, Wei; Porter, Ned A.; Schneider, Claus; Brash, Alan R.; Yin, Huiyong

    2010-01-01

    We report herein that oxidation of a mitochondria-specific phospholipid tetralinoleoyl cardiolipin (L4CL) by cytochrome c and H2O2 leads to the formation of 4-hydroxy-2-nonenal (4-HNE) via a novel chemical mechanism which involves cross-chain peroxyl radical addition and decomposition. As one of the most bioactive lipid electrophiles, 4-HNE possesses diverse biological activities ranging from modulation of multiple signal transduction pathways to the induction of intrinsic apoptosis. However, where and how 4-HNE is formed in vivo is much less understood. Recently a novel chemical mechanism has been proposed that involves inter-molecular dimerization of fatty acids by peroxyl bond formation; but the biological relevance of this mechanism is unknown because a majority of the fatty acids are esterified in phospholipids in the cellular membrane. We hypothesize that oxidation of cardiolipins, especially L4CL, may lead to the formation of 4-HNE via this novel mechanism. We employed L4CL and di-linoleoyl-phosphatidylcholine (DLPC) as model compounds to test this hypothesis. Indeed, in experiments designed to assess the intramolecular mechanism, more 4-HNE is formed from L4CL and DLPC oxidation than 1-palmitoyl-2-linoleoyl-phosphatydylcholine (PLPC). The key products and intermediates that are consistent with this proposed mechanism of 4-HNE formation have been identified using liquid chromatography – mass spectrometry (LC-MS) methods. Identical products from cardiolipin oxidation were identified in vivo in rat liver tissue after carbon tetrachloride treatment. Our studies provide the first evidence in vitro and in vivo for the formation 4-HNE from cardiolipin oxidation via cross-chain peroxyl radical addition and decomposition, which may have implications in apoptosis and other biological activities of 4-HNE. PMID:21047551

  18. Redox instability and hemin loss of mutant sperm whale myoglobins induced by 4-hydroxynonenal in vitro.

    PubMed

    Tatiyaborworntham, Nantawat; Faustman, Cameron; Yin, Shuang; Ramanathan, Ranjith; Mancini, Richard A; Suman, Surendranath P; Beach, Carol M; Maheswarappa, Naveena B; Grunwald, Eric W; Richards, Mark P

    2012-08-29

    The effects of 4-hydroxy-2-nonenal (HNE) on redox stability of Oxy- and Deoxy- wild-type (WT) and recombinant sperm whale myoglobins (P88H/Q152H, L29F, H97A, and H64F) and hemin loss from Met-myoglobin (Mb) were investigated. HNE induced greater redox instability in WT and mutant Mbs compared to controls (p < 0.05). The extent of HNE-induced OxyMb oxidation was lesser in L29F (p < 0.05) and greater in H97A and P88H/Q152H than in WT (p < 0.05). H64F DeoxyMb was more redox stable than WT DeoxyMb in the presence of HNE (p < 0.05). HNE alkylation occurred exclusively on histidine residues, and histidine 48 was alkylated in all sperm whale myoglobins. HNE alkylation accelerated the protoporphyrin moiety loss only in H97A. Met- forms of WT and L29F but not Deoxy- or Oxy- forms released hemin during storage. Primary structure strongly influenced Mb redox stability in the presence of reactive secondary lipid oxidation products.

  19. Identification of Protein Targets of 4-Hydroxynonenal Using Click Chemistry for Ex Vivo Biotinylation of Azido and Alkynyl Derivatives

    PubMed Central

    Vila, Andrew; Tallman, Keri A.; Jacobs, Aaron T.; Liebler, Daniel C.; Porter, Ned A.; Marnett, Lawrence J.

    2009-01-01

    Polyunsaturated fatty acids (PUFA) are primary targets of free radical damage during oxidative stress. Diffusible electrophilic α, β-unsaturated aldehydes, such as 4-hydroxynonenal (HNE), have been shown to modify proteins that mediate cell signaling (e.g. IKK and Keap1) and alter gene expression pathways responsible for inducing antioxidant genes, heat shock proteins, and the DNA damage response. To fully understand cellular responses to HNE, it is important to determine its protein targets in an unbiased fashion. This requires a strategy for detecting and isolating HNE-modified proteins regardless of the nature of the chemical linkage between HNE and its targets. Azido or alkynyl derivatives of HNE were synthesized and demonstrated to be equivalent to HNE in their ability to induce heme oxygenase induction and induce apoptosis in colon cancer (RKO) cells. Cells exposed to the tagged HNE derivatives were lysed and exposed to reagents to effect Staudinger ligation or copper-catalyzed Huisgen 1,3 dipolar cycloaddition reaction (click chemistry) to conjugate HNE-adducted proteins with biotin for subsequent affinity purification. Both strategies yielded efficient biotinylation of tagged HNE-protein conjugates but click chemistry was found to be superior for recovery of biotinylated proteins from streptavidin-coated beads. Biotinylated proteins were detected in lysates from RKO cell incubations with azido-HNE at concentrations as low as 1 μM. These proteins were affinity purified with streptavidin beads and proteomic analysis was performed by linear ion trap mass spectrometry. Proteomic analysis revealed a dose-dependent increase in labeled proteins with increased sequence coverage at higher concentrations. Several proteins involved in stress signaling (heat shock proteins 70 and 90, and the 78-kDa glucose-regulated protein) were selectively adducted by azido- and alkynyl-HNE. The use of azido and alkynyl derivatives in conjunction with click chemistry appears to be

  20. Phosphatase and Tensin Homolog Deleted on Chromosome 10 (PTEN) Inhibition by 4-Hydroxynonenal Leads to Increased Akt Activation in HepatocytesS⃞

    PubMed Central

    Shearn, Colin T.; Smathers, Rebecca L.; Stewart, Benjamin J.; Fritz, Kristofer S.; Galligan, James J.; Hail, Numsen

    2011-01-01

    The production of reactive aldehydes such as 4-hydroxynonenal (4-HNE) is proposed to be an important factor in the etiology of alcoholic liver disease. To understand the effects of 4-HNE on homeostatic signaling pathways in hepatocytes, cellular models consisting of the human hepatocellular carcinoma cell line (HepG2) and primary rat hepatocytes were evaluated. Treatment of both HepG2 cells and primary hepatocytes with subcytotoxic concentrations of 4-HNE resulted in the activation of Akt within 30 min as demonstrated by increased phosphorylation of residues Ser473 and Thr308. Quantification and subsequent immunocytochemistry of phosphatidylinositol-3,4,5-trisphosphate [PtdIns(3,4,5)P3[rsqb] resulted in a 6-fold increase in total PtdIns(3,4,5)P3 and increased immunostaining at the plasma membrane after 4-HNE treatment. Cotreatment of HepG2 cells with 4-HNE and the phosphatidylinositol 3-kinase (PI3K) inhibitor 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (Ly294002) or the protein phosphatase 2A (PP2A) inhibitor okadaic acid revealed that the mechanism of activation of Akt is PI3K-dependent and PP2A-independent. Using biotin hydrazide detection, it was established that the incubation of HepG2 cells with 4-HNE resulted in increased carbonylation of the lipid phosphatase known as “phosphatase and tensin homolog deleted on chromosome 10” (PTEN), a key regulator of Akt activation. Activity assays both in HepG2 cells and recombinant PTEN revealed a decrease in PTEN lipid phosphatase activity after 4-HNE application. Mass spectral analysis of 4-HNE-treated recombinant PTEN detected a single 4-HNE adduct. Subsequent analysis of Akt dependent physiological consequences of 4-HNE in HepG2 cells revealed significant increases in the accumulation of neutral lipids. These results provide a potential mechanism of Akt activation and cellular consequences of 4-HNE in hepatocytes. PMID:21415306

  1. Replication Bypass of the trans-4-Hydroxynonenal-Derived (6S,8R,11S)-1,N[superscript 2]-Deoxyguanosine DNA Adduct by the Sulfolobus solfataricus DNA Polymerase IV

    SciTech Connect

    Banerjee, Surajit; Christov, Plamen P.; Kozekova, Albena

    2014-10-02

    trans-4-Hydroxynonenal (HNE) is the major peroxidation product of {omega}-6 polyunsaturated fatty acids in vivo. Michael addition of the N{sub 2}-amino group of dGuo to HNE followed by ring closure of N1 onto the aldehyde results in four diastereomeric 1,N{sub 2}-dGuo (1,N{sub 2}-HNE-dGuo) adducts. The (6S,8R,11S)-HNE-1,N{sub 2}-dGuo adduct was incorporated into the 18-mer templates 5'-d(TCATXGAATCCTTCCCCC)-3' and d(TCACXGAATCCTTCCCCC)-3', where X = (6S,8R,11S)-HNE-1,N{sub 2}-dGuo adduct. These differed in the identity of the template 5'-neighbor base, which was either Thy or Cyt, respectively. Each of these templates was annealed with either a 13-mer primer 5'-d(GGGGGAAGGATTC)-3' or a 14-mer primer 5'-d(GGGGGAAGGATTCC)-3'. The addition of dNTPsmore » to the 13-mer primer allowed analysis of dNTP insertion opposite to the (6S,8R,11S)-HNE-1,N{sub 2}-dGuo adduct, whereas the 14-mer primer allowed analysis of dNTP extension past a primed (6S,8R,11S)-HNE-1,N{sub 2}-dGuo:dCyd pair. The Sulfolobus solfataricus P2 DNA polymerase IV (Dpo4) belongs to the Y-family of error-prone polymerases. Replication bypass studies in vitro reveal that this polymerase inserted dNTPs opposite the (6S,8R,11S)-HNE-1,N{sub 2}-dGuo adduct in a sequence-specific manner. If the template 5'-neighbor base was dCyt, the polymerase inserted primarily dGTP, whereas if the template 5'-neighbor base was dThy, the polymerase inserted primarily dATP. The latter event would predict low levels of Gua {yields} Thy mutations during replication bypass when the template 5'-neighbor base is dThy. When presented with a primed (6S,8R,11S)-HNE-1,N{sub 2}-dGuo:dCyd pair, the polymerase conducted full-length primer extension. Structures for ternary (Dpo4-DNA-dNTP) complexes with all four template-primers were obtained. For the 18-mer:13-mer template-primers in which the polymerase was confronted with the (6S,8R,11S)-HNE-1,N{sub 2}-dGuo adduct, the (6S,8R,11S)-1,N{sub 2}-dGuo lesion remained in the ring

  2. 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.

  3. 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.

  4. S-adenosyl-L-methionine protection of acetaminophen mediated oxidative stress and identification of hepatic 4-hydroxynonenal protein adducts by mass spectrometry

    SciTech Connect

    Brown, James Mike; Kuhlman, Christopher; Terneus, Marcus V.; Labenski, Matthew T.; Lamyaithong, Andre Benja; Ball, John G.; Lau, Serrine S.; Valentovic, Monica A.

    2014-12-01

    Acetaminophen (APAP) hepatotoxicity is protected by S-adenosyl-L-methionine (SAMe) treatment 1 hour (h) after APAP in C57/Bl6 mice. This study examined protein carbonylation as well as mitochondrial and cytosolic protein adduction by 4-hydroxynonenal (4-HNE) using mass spectrometry (MS) analysis. Additional studies investigated the leakage of mitochondrial proteins and 4-HNE adduction of these proteins. Male C57/Bl6 mice (n = 5/group) were divided into the following groups and treated as indicated: Veh (15 ml/kg water, ip), SAMe (1.25 mmol/kg, ip), APAP (250 mg/kg), and SAMe given 1 h after APAP (S + A). APAP toxicity was confirmed by an increase (p < 0.05) in plasma ALT (U/l) and liver weight/10 g body weight relative to the Veh, SAMe and S + A groups 4 h following APAP treatment. SAMe administered 1 h post-APAP partially corrected APAP hepatotoxicity as ALT and liver weight/10 g body weights were lower in the S + A group compared the APAP group. APAP induced leakage of the mitochondrial protein, carbamoyl phosphate synthase-1 (CPS-1) into the cytosol and which was reduced in the S + A group. SAMe further reduced the extent of APAP mediated 4-HNE adduction of CPS-1. MS analysis of hepatic and mitochondrial subcellular fractions identified proteins from APAP treated mice. Site specific 4-HNE adducts were identified on mitochondrial proteins sarcosine dehydrogenase and carbamoyl phosphate synthase-1 (CPS-1). In summary, APAP is associated with 4-HNE adduction of proteins as identified by MS analysis and that CPS-1 leakage was greater in APAP treated mice. SAMe reduced the extent of 4-HNE adduction of proteins as well as leakage of CPS-1. - Highlights: • Acetaminophen (APAP) toxicity protected by S-adenosylmethionine (SAMe) • 4-Hydroxynonenal adducted to sarcosine dehydrogenase • 4-Hydroxynonenal adducted to carbamoyl phosphate synthetase-1 • SAMe reduced APAP mediated CPS-1 mitochondrial leakage.

  5. [The level of lipid peroxidation in milk replacer formulas for initial feeding of infants].

    PubMed

    Czeczot, Hanna; Cichosz, Grażyna; Ambroziak, Adam

    2015-02-01

    The products of lipids oxidation: peroxides, hydroxides, aldehydes, ketones, esters, alcohols and others show harmful activity against human organism. Presence of the compounds in baby's and children's food creates potential health hazard. Many of them cause infant's and children's diarrhoea, also, negatively influence development of nervous system, show cytotoxic, mutagenic and cancerogenic activity (e.g. malonicdialdehyde, 4-hydroxynonenal and others). The aim of the work was to assess the level of lipids peroxidation in milk substitute preparations for initial stage baby feeding, before their end of shelf-life. The level of lipids peroxidation measured as TBARS (thiobarbituric acid reactive substances) concentrations was determined in 6 available on the Polish market milk substitute infant formulas. The determinations was carried out before the end of the shelf-life after 1,2,3,6,9 and 12 months after purchase. The level of lipid peroxidation was also determined after 3-4 and 21 days post opening. TBARS content in the infants food ready to be eaten depended on the time of preparation storage. The highest level of lipids peroxidation was observed in all the studied food after 12 months of storage and after 21 days after opening of the hermetical wrapping. Various level of lipids peroxidation in milk substitutes for infant nutrition resulted from different amounts and quality of plant oils used in production (different content of mono- and polyunsaturated fatty acids, presence of lack of linoleic and α-linolenic acids). © 2015 MEDPRESS.

  6. S-adenosyl-L-methionine protection of acetaminophen mediated oxidative stress and identification of hepatic 4-hydroxynonenal protein adducts by mass spectrometry

    SciTech Connect

    Brown, James Mike; Kuhlman, Christopher; Terneus, Marcus V.

    2014-12-01

    Acetaminophen (APAP) hepatotoxicity is protected by S-adenosyl-L-methionine (SAMe) treatment 1 hour (h) after APAP in C57/Bl6 mice. This study examined protein carbonylation as well as mitochondrial and cytosolic protein adduction by 4-hydroxynonenal (4-HNE) using mass spectrometry (MS) analysis. Additional studies investigated the leakage of mitochondrial proteins and 4-HNE adduction of these proteins. Male C57/Bl6 mice (n = 5/group) were divided into the following groups and treated as indicated: Veh (15 ml/kg water, ip), SAMe (1.25 mmol/kg, ip), APAP (250 mg/kg), and SAMe given 1 h after APAP (S + A). APAP toxicity was confirmed by an increase (p < 0.05)more » in plasma ALT (U/l) and liver weight/10 g body weight relative to the Veh, SAMe and S + A groups 4 h following APAP treatment. SAMe administered 1 h post-APAP partially corrected APAP hepatotoxicity as ALT and liver weight/10 g body weights were lower in the S + A group compared the APAP group. APAP induced leakage of the mitochondrial protein, carbamoyl phosphate synthase-1 (CPS-1) into the cytosol and which was reduced in the S + A group. SAMe further reduced the extent of APAP mediated 4-HNE adduction of CPS-1. MS analysis of hepatic and mitochondrial subcellular fractions identified proteins from APAP treated mice. Site specific 4-HNE adducts were identified on mitochondrial proteins sarcosine dehydrogenase and carbamoyl phosphate synthase-1 (CPS-1). In summary, APAP is associated with 4-HNE adduction of proteins as identified by MS analysis and that CPS-1 leakage was greater in APAP treated mice. SAMe reduced the extent of 4-HNE adduction of proteins as well as leakage of CPS-1. - Highlights: • Acetaminophen (APAP) toxicity protected by S-adenosylmethionine (SAMe) • 4-Hydroxynonenal adducted to sarcosine dehydrogenase • 4-Hydroxynonenal adducted to carbamoyl phosphate synthetase-1 • SAMe reduced APAP mediated CPS-1 mitochondrial leakage.« less

  7. Damage to photosystem II by lipid peroxidation products.

    PubMed

    Pospíšil, Pavel; Yamamoto, Yasusi

    2017-02-01

    Photosystem II proteins of higher plant chloroplasts are prone to oxidative stress, and most prominently the reaction center-binding D1 protein is damaged under abiotic stress. The reactive oxygen species produced under these stress conditions have been suggested to be responsible for the protein injury. Recently, it has been shown that the primary and secondary products of non-enzymatic and enzymatic lipid peroxidation have a capability to modify photosystem II proteins. Here, we give an overview showing how lipid peroxidation products formed under light stress and heat stress in the thylakoid membranes cause oxidative modification of proteins in higher plant photosystem II. Damage to photosystem II proteins by lipid peroxidation products represents a new mechanism underlying photoinhibition and heat inactivation. Complete characterization of photosystem II protein damage is of crucial importance because avoidance of the damage makes plants to survive under various abiotic stresses. Further physiological significance of photosystem II protein oxidation by lipid peroxidation product should have a potential relevance to plant acclimation because the oxidized proteins might serve as signaling molecules. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Electrochemical production of ozone and hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Murphy, Oliver J. (Inventor); Hitchens, G. Duncan (Inventor)

    1999-01-01

    Methods of using ozone have been developed which sterilize instruments and medical wastes, oxidize organics found in wastewater, clean laundry, break down contaminants in soil into a form more readily digested by microbes, kill microorganisms present in food products, and destroy toxins present in food products. The preferred methods for killing microorganisms and destroying toxins use pressurized, humidified, and concentrated ozone produced by an electrochemical cell.

  9. Methods to create thermally oxidized lipids and comparison of analytical procedures to characterize peroxidation.

    PubMed

    Liu, P; Kerr, B J; Chen, C; Weber, T E; Johnston, L J; Shurson, G C

    2014-07-01

    The objective of this experiment was to evaluate peroxidation in 4 lipids, each with 3 levels of peroxidation. Lipid sources were corn oil (CN), canola oil (CA), poultry fat, and tallow. Peroxidation levels were original lipids (OL), slow-oxidized lipids (SO), and rapid-oxidized lipids (RO). To produce peroxidized lipids, OL were either heated at 95°C for 72 h to produce SO or heated at 185°C for 7 h to produce RO. Five indicative measurements (peroxide value [PV], p-anisidine value [AnV], thiobarbituric acid reactive substances [TBARS] concentration, hexanal concentration, 4-hydroxynonenal [HNE] concentration, and 2,4-decadienal [DDE]) and 2 predictive tests (active oxygen method [AOM] stability and oxidative stability index [OSI]) were performed to quantify the level of oxidation of the subsequent 12 lipids with varying levels of peroxidation. Analysis showed that a high PV accurately indicated the high level of lipid peroxidation, but a moderate or low PV may be misleading due to the unstable characteristics of hydroperoxides as indicated by the unchanged PV of rapidly oxidized CN and CA compared to their original state (OL). However, additional tests, which measure secondary peroxidation products such as AnV, TBARS, hexanal, HNE, and DDE, may provide a better indication of lipid peroxidation than PV for lipids subjected to a high level of peroxidation. Similar to PV analysis, these tests may also not provide irrefutable information regarding the extent of peroxidation because of the volatile characteristics of secondary peroxidation products and the changing stage of lipid peroxidation. For the predictive tests, AOM accurately reflected the increased lipid peroxidation caused by SO and RO as indicated by the increased AOM value in CN and CA but not in poultry fat and tallow, which indicated a potential disadvantage of the AOM test. Oxidative stability index successfully showed the increased lipid peroxidation caused by SO and RO in all lipids, but it too may

  10. 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 discharges...

  11. 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 discharges...

  12. 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 discharges...

  13. 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 discharges...

  14. 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 discharges...

  15. SELECTIVE SEPARATION OF URANIUM FROM THORIUM, PROTACTINIUM AND FISSION PRODUCTS BY PEROXIDE DISSOLUTION METHOD

    DOEpatents

    Seaborg, G.T.; Gofman, J.W.; Stoughton, R.W.

    1959-08-18

    A method is described for separating U/sup 233/ from thorium and fission products. The separation is effected by forming a thorium-nitric acid solution of about 3 pH, adding hydrogen peroxide to precipitate uranium and thorium peroxide, treating the peroxides with sodium hydroxide to selectively precipitate the uranium peroxide, and reacting the separated solution with nitric acid to re- precipitate the uranium peroxide.

  16. Synthesis of five- and six-membered cyclic organic peroxides: Key transformations into peroxide ring-retaining products.

    PubMed

    Terent'ev, Alexander O; Borisov, Dmitry A; Vil', Vera A; Dembitsky, Valery M

    2014-01-08

    The present review describes the current status of synthetic five and six-membered cyclic peroxides such as 1,2-dioxolanes, 1,2,4-trioxolanes (ozonides), 1,2-dioxanes, 1,2-dioxenes, 1,2,4-trioxanes, and 1,2,4,5-tetraoxanes. The literature from 2000 onwards is surveyed to provide an update on synthesis of cyclic peroxides. The indicated period of time is, on the whole, characterized by the development of new efficient and scale-up methods for the preparation of these cyclic compounds. It was shown that cyclic peroxides remain unchanged throughout the course of a wide range of fundamental organic reactions. Due to these properties, the molecular structures can be greatly modified to give peroxide ring-retaining products. The chemistry of cyclic peroxides has attracted considerable attention, because these compounds are used in medicine for the design of antimalarial, antihelminthic, and antitumor agents.

  17. Synthesis of five- and six-membered cyclic organic peroxides: Key transformations into peroxide ring-retaining products

    PubMed Central

    Borisov, Dmitry A; Vil’, Vera A; Dembitsky, Valery M

    2014-01-01

    Summary The present review describes the current status of synthetic five and six-membered cyclic peroxides such as 1,2-dioxolanes, 1,2,4-trioxolanes (ozonides), 1,2-dioxanes, 1,2-dioxenes, 1,2,4-trioxanes, and 1,2,4,5-tetraoxanes. The literature from 2000 onwards is surveyed to provide an update on synthesis of cyclic peroxides. The indicated period of time is, on the whole, characterized by the development of new efficient and scale-up methods for the preparation of these cyclic compounds. It was shown that cyclic peroxides remain unchanged throughout the course of a wide range of fundamental organic reactions. Due to these properties, the molecular structures can be greatly modified to give peroxide ring-retaining products. The chemistry of cyclic peroxides has attracted considerable attention, because these compounds are used in medicine for the design of antimalarial, antihelminthic, and antitumor agents. PMID:24454562

  18. 4-Hydroxy-nonenal—A Bioactive Lipid Peroxidation Product

    PubMed Central

    Schaur, Rudolf J.; Siems, Werner; Bresgen, Nikolaus; Eckl, Peter M.

    2015-01-01

    This review on recent research advances of the lipid peroxidation product 4-hydroxy-nonenal (HNE) has four major topics: I. the formation of HNE in various organs and tissues, II. the diverse biochemical reactions with Michael adduct formation as the most prominent one, III. the endogenous targets of HNE, primarily peptides and proteins (here the mechanisms of covalent adduct formation are described and the (patho-) physiological consequences discussed), and IV. the metabolism of HNE leading to a great number of degradation products, some of which are excreted in urine and may serve as non-invasive biomarkers of oxidative stress. PMID:26437435

  19. Rapid liquid chromatography-tandem mass spectrometry analysis of 4-hydroxynonenal for the assessment of oxidative degradation and safety of vegetable oils.

    PubMed

    Gabbanini, Simone; Matera, Riccardo; Valvassori, Alice; Valgimigli, Luca

    2015-04-15

    A novel method for the UHPLC-MS/MS analysis of (E)-4-hydroxynonenal (4-HNE) is described. The method is based on derivatization of 4-HNE with pentafluorophenylhydrazine (1) or 4-trifluoromethylphenylhydrazine (2) in acetonitrile in the presence of trifluoroacetic acid as catalyst at room temperature and allows complete analysis of one sample of vegetable oil in only 21 min, including sample preparation and chromatography. The method involving hydrazine 1, implemented in an ion trap instrument with analysis of the transition m/z 337→154 showed LOD=10.9 nM, average accuracy of 101% and precision ranging 2.5-4.0% RSD intra-day (2.7-4.1% RSD inter-day), with 4-HNE standard solutions. Average recovery from lipid matrices was 96.3% from vaseline oil, 91.3% from sweet almond oil and 105.3% from olive oil. The method was tested on the assessment of safety and oxidative degradation of seven samples of dietary oil (soybean, mixed seeds, corn, peanut, sunflower, olive) and six cosmetic-grade oils (avocado, blackcurrant, apricot kernel, echium, sesame, wheat germ) and effectively detected increased 4-HNE levels in response to chemical (Fenton reaction), photochemical, or thermal stress and aging, aimed at mimicking typical oxidation associated with storage or industrial processing. The method is a convenient, cost-effective and reliable tool to assess quality and safety of vegetable oils. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Kinetic release of hydrogen peroxide from different whitening products.

    PubMed

    da Silva Marques, Duarte Nuno; Silveira, Joao Miguel; Marques, Joana Rita; Amaral, Joao Almeida; Guilherme, Nuno Marques; da Mata, António Duarte

    2012-01-01

    The objective of this in vitro study was to evaluate the kinetics of hydrogen peroxide (HP) release from five different bleaching products: VivaStyle® 10% fitted tray gel, VivaStyle® 30% in-office bleaching gel, VivaStyle® Paint-On Plus paint-on bleaching varnish, Opalescence PF® 10% carbamide peroxide gel and Trèswhite Supreme™ 10% HP gel. Each product was firstly titrated for its HP content by a described method. HP release kinetics was assessed by a modified spectrophotometric technique. One sample t test was performed to test for differences between the manufacturers' claimed HP concentrations and the titrated HP content in the whitening products. Analysis of variance plus Tamhane's post hoc tests and Pearson correlation analysis were used as appropriate. Values of P < 0.05 were taken as significant. Titrated HP revealed an increased content when compared to the manufacturer's specifications for all the products tested (P < 0.05), although only products from one manufacturer produced significantly higher results. All products presented a significant (P < 0.05) and sustained release of HP. However, the product with paint-on cellulose-based matrix resulted in significantly (P < 0.05) faster kinetics when compared to other products tested. These results are consistent with manufacturers' reduced recommended application times. The results of this study suggest that modifying the matrix composition may be a viable alternative to HP concentration increase, since this may result in faster release kinetics without exposure to high HP concentrations.

  1. Time-resolved fluorescence spectroscopy investigation of the effect of 4-hydroxynonenal on endogenous NAD(P)H in living cardiac myocytes

    NASA Astrophysics Data System (ADS)

    Chorvatova, Alzbeta; Aneba, Swida; Mateasik, Anton; Chorvat, Dusan; Comte, Blandine

    2013-06-01

    Lipid peroxidation is a major biochemical consequence of the oxidative deterioration of polyunsaturated lipids in cell membranes and causes damage to membrane integrity and loss of protein function. 4-hydroxy-2-nonenal (HNE), one of the most reactive products of n-6 polyunsaturated fatty acid peroxidation of membrane phospholipids, has been shown to be capable of affecting both nicotinamide adenine dinucleotide (phosphate) reduced [NAD(P)H] as well as NADH production. However, the understanding of its effects in living cardiac cells is still lacking. Our goal was to therefore investigate HNE effects on NAD(P)H noninvasively in living cardiomyocytes. Spectrally resolved lifetime detection of endogenous fluorescence, an innovative noninvasive technique, was employed. Individual fluorescence components were resolved by spectral linear unmixing approach. Gathered results revealed that HNE reduced the amplitude of both resolved NAD(P)H components in a concentration-dependent manner. In addition, HNE increased flavoprotein fluorescence and responsiveness of the NAD(P)H component ratio to glutathione reductase (GR) inhibitor. HNE also increased the percentage of oxidized nucleotides and decreased maximal NADH production. Presented data indicate that HNE provoked an important cell oxidation by acting on NAD(P)H regulating systems in cardiomyocytes. Understanding the precise role of oxidative processes and their products in living cells is crucial for finding new noninvasive tools for biomedical diagnostics of pathophysiological states.

  2. Clinical trial of three 10% carbamide peroxide bleaching products.

    PubMed

    Tam, L

    1999-04-01

    A profusion of commercial bleaching systems exists on the market today, but there are few clinical comparisons of these systems. In this study, three different commercial 10% carbamide peroxide bleaching systems were used by 24 patients in an overnight protocol for two weeks. Each patient used two of the bleaching products simultaneously in a side-by-side comparison. The mean onset of tooth whitening was 2.4 +/- 1.7 days. Tooth sensitivity was the most frequent side effect, as 64% of the patients reported tooth sensitivity occurring after 4.8 +/- 4.1 days and lasting for 5.0 +/- 3.8 days. Although intrapatient differences were recorded for the three commercial 10% carbamide peroxide bleaching systems by the patients, there were no statistical differences in the time of onset of subjective tooth whitening and the onset, frequency and duration of tooth sensitivity among the three commercial bleaching systems when compared pairwise or independently (p < 0.05). Selection of which bleaching product to use should be based on the concentration of the active ingredient, the viscosity of the product and other marketing features. Further research is needed to investigate the causes of tooth sensitivity and methods to reduce its severity and frequency.

  3. 4-Hydroxynonenal Induces Rat γ-Glutamyl Transpeptidase through Mitogen-Activated Protein Kinase-Mediated Electrophile Response Element/Nuclear Factor Erythroid 2-Related Factor 2 Signaling

    PubMed Central

    Zhang, Hongqiao; Liu, Honglei; Iles, Karen E.; Liu, Rui-Ming; Postlethwait, Edward M.; Laperche, Yannick; Forman, Henry Jay

    2009-01-01

    γ-Glutamyl transpeptidase (GGT) plays critical roles in glutathione homeostasis and metabolism. Rat GGT is a single-copy gene from which seven types of GGT mRNA with a common protein encoding sequence, but different 5′-untranslated regions, may be transcribed. We previously showed that type V-2 was the predominant form of GGT mRNA in rat L2 epithelial cells, and that it could be induced by 4-hydroxynonenal (HNE) through the electrophile response element (EpRE) located in GGT promoter 5 (GP5). Here, we report transcription factors binding to GP5 EpRE and the involved signaling pathways. Immunodepletion gel shift assays demonstrated that GP5 EpRE bound JunB, c-Jun, FosB, and Fra2 from unstimulated cells, and that after exposure to HNE, EpRE binding complexes contained nuclear factor erythroid 2-related factor (Nrf) 1, Nrf2, JunB, c-Jun, FosB, c-Fos, Fra1, and Fra2. HNE-induced binding of Nrf2 and c-Jun in GP5 EpRE was confirmed by chromatin immunoprecipitation assays. Using reporter assays and specific inhibitors, we found that HNE induction of rat GGT mRNA V-2 was dependent on activation of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK), but not protein kinase C or phosphatidylinositol 3-kinase. Pretreatment with ERK and p38MAPK inhibitors also blocked HNE-increased EpRE binding. HNE-increased nuclear content of Nrf1, Nrf2, and c-Jun in L2 cells was partially blocked by inhibition of either ERK1/2 or p38MAPK and completely blocked by simultaneous inhibition of both MAPKs. In conclusion, HNE induces GGT mRNA V-2 through altered EpRE transcription factor binding mediated by both ERK and p38MAPK. PMID:16195535

  4. 4-Hydroxynonenal self-limits Fas-mediated DISC independent apoptosis by promoting export of Daxx from nucleus to cytosol and its binding to Fas†

    PubMed Central

    Sharma, Rajendra; Sharma, Abha; Dwivedi, Seema; Zimniak, Piotr; Awasthi, Sanjay; Awasthi, Yogesh C.

    2008-01-01

    Previously, we have shown that 4-hydroxynonenal (4-HNE) induces Fas-mediated apoptosis in HLE B-3 cells through a pathway which is independent of FasL, FADD, procaspase8-and DISC (Li, J. et al. Biochemistry, 45, 12253-12264). The involvement of Daxx has also been suggested in this pathway but its role is not clear. Here, we report that Daxx plays an important regulatory role during 4-HNE induced, Fas-mediated apoptosis in Jurkat cells. 4-HNE induces Fas-dependent apoptosis in procaspase8 deficient Jurkat cells via the activation of ASK1, JNK and caspase3 and the apoptosis can be inhibited by masking Fas with the antagonistic anti-Fas antibodies. We demonstrate that 4-HNE exposure to Jurkat cells leads to the induction of both Fas and Daxx. 4-HNE binds to both Fas and Daxx and promotes the export of Daxx from nucleus to cytosol where it binds to Fas and inhibits apoptosis. Depletion of Daxx results in increase in the activation of ASK1, JNK, and caspase3 along with exacerbation of 4-HNE-induced apoptosis suggesting that Daxx inhibits apoptosis by binding to Fas. 4-HNE-induced translocation of the Daxx is also accompanied with the activation of the transcription factor HSF1. Results of these studies are consistent with a model in which by interacting with Fas, 4-HNE promotes pro-apoptotic signaling via ASK1, JNK and caspase3. In parallel, 4-HNE induces Daxx and promotes its export from the nucleus to cytosol where it interacts with Fas to self-limit the extent of apoptosis by inhibiting the downstream pro-apoptotic signaling. Cytoplasmic translocation of Daxx also results in up-regulation of HSF1 associated stress responsive genes. PMID:18069800

  5. S-Adenosyl-L-Methionine Protection of Acetaminophen Mediated Oxidative Stress and Identification of Hepatic 4-Hydroxynonenal Protein Adducts by Mass Spectrometry

    PubMed Central

    Brown, James Mike; Kuhlman, Christopher; Terneus, Marcus V.; Labenski, Matthew T.; Lamyaithong, Andre Benja; Ball, John G.; Lau, Serrine S.; Valentovic, Monica A.

    2015-01-01

    Acetaminophen (APAP) hepatotoxicity is protected by S-adenosyl-L-methionine (SAMe) treatment 1 hour (h) after APAP in C57/Bl6 mice. This study examined protein carbonylation as well as mitochondrial and cytosolic protein adduction by 4-hydroxynonenal (4-HNE) using mass spectrometry (MS) analysis. Additional studies investigated the leakage of mitochondrial proteins and 4-HNE adduction of these proteins. Male C57/Bl6 mice (n=5/group) were divided into the following groups and treated as indicated: Veh (15 ml/kg water, ip), SAMe (1.25 mmol/kg, ip), APAP (250 mg/kg), and SAMe given 1 h after APAP (S+A). APAP toxicity was confirmed by an increase (p<0.05) in plasma ALT (U/L) and liver weight/10 g body weight relative to the Veh, SAMe and S+A groups 4 h following APAP treatment. SAMe administered 1 h post APAP partially corrected APAP hepatotoxicity as ALT and liver weight/10 g body weights were lower in the S+A group compared the APAP group. APAP induced leakage of the mitochondrial protein, carbamoyl phosphate synthase-1 (CPS-1) into the cytosol and which was reduced in the S+A group. SAMe further reduced the extent of APAP mediated 4-HNE adduction of CPS-1. MS analysis of hepatic and mitochondrial subcellular fractions identified proteins from APAP treated mice. Site specific 4-HNE adducts were identified on mitochondrial proteins sarcosine dehydrogenase and carbamoyl phosphate synthase-1 (CPS-1). In summary, APAP is associated with 4-HNE adduction of proteins as identified by MS analysis and that CPS-1 leakage was greater in APAP treated mice. SAMe reduced the extent of 4-HNE adduction of proteins as well as leakage of CPS-1. PMID:25246065

  6. Evidence in Support of Potential Applications of Lipid Peroxidation Products in Cancer Treatment

    PubMed Central

    Erejuwa, Omotayo O.; Sulaiman, Siti A.; Ab Wahab, Mohd S.

    2013-01-01

    Cancer cells generate reactive oxygen species (ROS) resulting from mitochondrial dysfunction, stimulation of oncogenes, abnormal metabolism, and aggravated inflammatory activities. Available evidence also suggests that cancer cells depend on intrinsic ROS level for proliferation and survival. Both physiological and pathophysiological roles have been ascribed to ROS which cause lipid peroxidation. In spite of their injurious effects, the ROS and the resulting lipid peroxidation products could be beneficial in cancer treatment. This review presents research findings suggesting that ROS and the resulting lipid peroxidation products could be utilized to inhibit cancer growth or induce cancer cell death. It also underscores the potential of lipid peroxidation products to potentiate the antitumor effect of other anticancer agents. The review also highlights evidence demonstrating other potential applications of lipid peroxidation products in cancer treatment. These include the prospect of lipid peroxidation products as a diagnostic tool to predict the chances of cancer recurrence, to monitor treatment progress or how well cancer patients respond to therapy. Further and detailed research is required on how best to successfully, effectively, and selectively target cancer cells in humans using lipid peroxidation products. This may prove to be an important strategy to complement current treatment regimens for cancer patients. PMID:24369491

  7. Modular Advanced Oxidation Process Enabled by Cathodic Hydrogen Peroxide Production

    PubMed Central

    2015-01-01

    Hydrogen peroxide (H2O2) is frequently used in combination with ultraviolet (UV) light to treat trace organic contaminants in advanced oxidation processes (AOPs). In small-scale applications, such as wellhead and point-of-entry water treatment systems, the need to maintain a stock solution of concentrated H2O2 increases the operational cost and complicates the operation of AOPs. To avoid the need for replenishing a stock solution of H2O2, a gas diffusion electrode was used to generate low concentrations of H2O2 directly in the water prior to its exposure to UV light. Following the AOP, the solution was passed through an anodic chamber to lower the solution pH and remove the residual H2O2. The effectiveness of the technology was evaluated using a suite of trace contaminants that spanned a range of reactivity with UV light and hydroxyl radical (HO•) in three different types of source waters (i.e., simulated groundwater, simulated surface water, and municipal wastewater effluent) as well as a sodium chloride solution. Irrespective of the source water, the system produced enough H2O2 to treat up to 120 L water d–1. The extent of transformation of trace organic contaminants was affected by the current density and the concentrations of HO• scavengers in the source water. The electrical energy per order (EEO) ranged from 1 to 3 kWh m–3, with the UV lamp accounting for most of the energy consumption. The gas diffusion electrode exhibited high efficiency for H2O2 production over extended periods and did not show a diminution in performance in any of the matrices. PMID:26039560

  8. Benzoyl Peroxide Topical

    MedlinePlus

    ... Up® (as a combination product containing Benzoyl Peroxide, Sulfur) ... NuOx® (as a combination product containing Benzoyl Peroxide, Sulfur) ... Sulfoxyl® (as a combination product containing Benzoyl Peroxide, Sulfur)

  9. Effect of hydrogen peroxide disinfection during incubation of chicken eggs on microbial levels and productivity.

    PubMed

    Sander, J E; Wilson, J L

    1999-01-01

    Hatchery sanitation has a significant impact on chick quality. The proper use of disinfectants is essential. Aerosol bacterial counts, egg moisture loss, hatchability, chick quality, and broiler productivity were measured in eggs exposed to hydrogen peroxide fogging and compared with eggs not exposed to disinfectant during the incubation period. Hydrogen peroxide was also evaluated in the presence of a severe challenge with Staphylococcus aureus-contaminated eggs. A significant reduction was found in aerosol bacterial counts within the hatcher when incubators were fogged with 3% hydrogen peroxide when compared with water-fogged machines even in the face of high bacterial challenge. Eggs exposed to hydrogen peroxide lost a significantly greater amount of moisture during incubation, but hatchability was not affected. The use of hydrogen peroxide as a hatchery sanitizer did not affect broiler livability, body weight, or feed conversion but did reduce the incidence of retained yolk sacs in 42-day-old chickens.

  10. Fluorescent products in high-density lipoproteins (HDL) and their association with other lipid peroxide products (LPPs)

    NASA Astrophysics Data System (ADS)

    Plavinski, Swiatoslav L.; Kuznetsov, Alexandr S.; Kopilevich, Yurij I.; Svetlykh, Alexander A.; Melnikov, Nikita O.

    1998-01-01

    The lipid peroxidation products of the lipofuscin type can be measured in plasma with the help of fluorimeters. Such products are increasing during whole plasm oxidation in parallel with other indices of lipid peroxidation damage. Preformed fluorescent products are located in all lipoprotein classes. The study of lipofuscin-type pigments fluorescence in HDL showed, that they contain substantial amounts of fluorescent compounds and that it rises in parallel with concentration of other lipid peroxidation products, especially thiobarbituric acid-reacting substances. Neither total plasma cholesterol, nor triglycerides influenced content of fluorescent products in HDL. The HDL subfractions contained different types of the fluorescent products but the bulk of these lipoproteins were almost free of them. The obtained data show that measurement of lipofuscin-type fluorescence in HDL gives a good and sensitive index of these lipoproteins damage by peroxidation.

  11. Lipid peroxidation: production, metabolism, and signaling mechanisms of malondialdehyde and 4-hydroxy-2-nonenal.

    PubMed

    Ayala, Antonio; Muñoz, Mario F; Argüelles, Sandro

    2014-01-01

    Lipid peroxidation can be described generally as a process under which oxidants such as free radicals attack lipids containing carbon-carbon double bond(s), especially polyunsaturated fatty acids (PUFAs). Over the last four decades, an extensive body of literature regarding lipid peroxidation has shown its important role in cell biology and human health. Since the early 1970s, the total published research articles on the topic of lipid peroxidation was 98 (1970-1974) and has been increasing at almost 135-fold, by up to 13165 in last 4 years (2010-2013). New discoveries about the involvement in cellular physiology and pathology, as well as the control of lipid peroxidation, continue to emerge every day. Given the enormity of this field, this review focuses on biochemical concepts of lipid peroxidation, production, metabolism, and signaling mechanisms of two main omega-6 fatty acids lipid peroxidation products: malondialdehyde (MDA) and, in particular, 4-hydroxy-2-nonenal (4-HNE), summarizing not only its physiological and protective function as signaling molecule stimulating gene expression and cell survival, but also its cytotoxic role inhibiting gene expression and promoting cell death. Finally, overviews of in vivo mammalian model systems used to study the lipid peroxidation process, and common pathological processes linked to MDA and 4-HNE are shown.

  12. Lipid Peroxidation: Production, Metabolism, and Signaling Mechanisms of Malondialdehyde and 4-Hydroxy-2-Nonenal

    PubMed Central

    Muñoz, Mario F.; Argüelles, Sandro

    2014-01-01

    Lipid peroxidation can be described generally as a process under which oxidants such as free radicals attack lipids containing carbon-carbon double bond(s), especially polyunsaturated fatty acids (PUFAs). Over the last four decades, an extensive body of literature regarding lipid peroxidation has shown its important role in cell biology and human health. Since the early 1970s, the total published research articles on the topic of lipid peroxidation was 98 (1970–1974) and has been increasing at almost 135-fold, by up to 13165 in last 4 years (2010–2013). New discoveries about the involvement in cellular physiology and pathology, as well as the control of lipid peroxidation, continue to emerge every day. Given the enormity of this field, this review focuses on biochemical concepts of lipid peroxidation, production, metabolism, and signaling mechanisms of two main omega-6 fatty acids lipid peroxidation products: malondialdehyde (MDA) and, in particular, 4-hydroxy-2-nonenal (4-HNE), summarizing not only its physiological and protective function as signaling molecule stimulating gene expression and cell survival, but also its cytotoxic role inhibiting gene expression and promoting cell death. Finally, overviews of in vivo mammalian model systems used to study the lipid peroxidation process, and common pathological processes linked to MDA and 4-HNE are shown. PMID:24999379

  13. Electrocatalytic synthesis of hydrogen peroxide on Au-Pd nanoparticles: From fundamentals to continuous production

    NASA Astrophysics Data System (ADS)

    Pizzutilo, Enrico; Kasian, Olga; Choi, Chang Hyuck; Cherevko, Serhiy; Hutchings, Graham J.; Mayrhofer, Karl J. J.; Freakley, Simon J.

    2017-09-01

    The electrochemical synthesis of hydrogen peroxide (H2O2) represents a promising alternative to the anthraquinone process, as it combines on-site chemical and electrical production. The design of selective electrocatalysts is challenging and is commonly based on the alloying of elements to generate a synergistic effect and increase activity. In the present work, we report the electrochemical activity of Au-Pd nanoparticles immobilized directly onto an electrode as a model to study H2O2 electrochemical synthesis from fundamentals to continuous production. The impact of composition on the oxygen reduction reaction (ORR), the selectivity, as well as the peroxide reduction and oxidation reactions (PROR) are studied.

  14. Solar-Driven Hydrogen Peroxide Production Using Polymer-Supported Carbon Dots as Heterogeneous Catalyst

    NASA Astrophysics Data System (ADS)

    Gogoi, Satyabrat; Karak, Niranjan

    2017-10-01

    Safe, sustainable, and green production of hydrogen peroxide is an exciting proposition due to the role of hydrogen peroxide as a green oxidant and energy carrier for fuel cells. The current work reports the development of carbon dot-impregnated waterborne hyperbranched polyurethane as a heterogeneous photo-catalyst for solar-driven production of hydrogen peroxide. The results reveal that the carbon dots possess a suitable band-gap of 2.98 eV, which facilitates effective splitting of both water and ethanol under solar irradiation. Inclusion of the carbon dots within the eco-friendly polymeric material ensures their catalytic activity and also provides a facile route for easy catalyst separation, especially from a solubilizing medium. The overall process was performed in accordance with the principles of green chemistry using bio-based precursors and aqueous medium. This work highlights the potential of carbon dots as an effective photo-catalyst.

  15. Trends in Selective Hydrogen Peroxide Production on Transition Metal Surfaces from First Principles

    SciTech Connect

    Rankin, Rees B.; Greeley, Jeffrey P.

    2012-10-19

    We present a comprehensive, Density Functional Theory-based analysis of the direct synthesis of hydrogen peroxide, H2O2, on twelve transition metal surfaces. We determine the full thermodynamics and selected kinetics of the reaction network on these metals, and we analyze these energetics with simple, microkinetically motivated rate theories to assess the activity and selectivity of hydrogen peroxide production on the surfaces of interest. By further exploiting Brønsted-Evans-Polanyi relationships and scaling relationships between the binding energies of different adsorbates, we express the results in the form of a two dimensional contour volcano plot, with the activity and selectivity being determined as functions of two independent descriptors, the atomic hydrogen and oxygen adsorption free energies. We identify both a region of maximum predicted catalytic activity, which is near Pt and Pd in descriptor space, and a region of selective hydrogen peroxide production, which includes Au. The optimal catalysts represent a compromise between activity and selectivity and are predicted to fall approximately between Au and Pd in descriptor space, providing a compact explanation for the experimentally known performance of Au-Pd alloys for hydrogen peroxide synthesis, and suggesting a target for future computational screening efforts to identify improved direct hydrogen peroxide synthesis catalysts. Related methods of combining activity and selectivity analysis into a single volcano plot may be applicable to, and useful for, other aqueous phase heterogeneous catalytic reactions where selectivity is a key catalytic criterion.

  16. Trends in Selective Hydrogen Peroxide Production on Transition Metal Surfaces from First Principles

    SciTech Connect

    Rankin, Rees B.; Greeley, Jeffrey P.

    2012-10-19

    We present a comprehensive, Density Functional Theory-based analysis of the direct synthesis of hydrogen peroxide, H2O2, on twelve transition metal surfaces. We determine the full thermodynamics and selected kinetics of the reaction network on these metals, and we analyze these energetics with simple, microkinetically motivated rate theories to assess the activity and selectivity of hydrogen peroxide production on the surfaces of interest. By further exploiting Brønsted-Evans-Polanyi relationships and scaling relationships between the binding energies of different adsorbates, we express the results in the form of a two dimensional contour volcano plot, with the activity and selectivity being determined as functionsmore » of two independent descriptors, the atomic hydrogen and oxygen adsorption free energies. We identify both a region of maximum predicted catalytic activity, which is near Pt and Pd in descriptor space, and a region of selective hydrogen peroxide production, which includes Au. The optimal catalysts represent a compromise between activity and selectivity and are predicted to fall approximately between Au and Pd in descriptor space, providing a compact explanation for the experimentally known performance of Au-Pd alloys for hydrogen peroxide synthesis, and suggesting a target for future computational screening efforts to identify improved direct hydrogen peroxide synthesis catalysts. Related methods of combining activity and selectivity analysis into a single volcano plot may be applicable to, and useful for, other aqueous phase heterogeneous catalytic reactions where selectivity is a key catalytic criterion.« less

  17. [Accumulation of lipid peroxidation products in the human lens during cataract maturation].

    PubMed

    Babizhaev, M A

    1985-01-01

    130 human lens impaired with cataract of various etiology (senile, traumatic, complicated cataract) and of different cataract maturation (initial, immature, quite mature, mature, over-maturated) as well as 18 transparent lens were studied. Primary products of lipid peroxidation (LP, hydroperoxides), secondary products (ketodiens) and the end products (Shiff bases) were distinctly accumulated in cataract lens. Intermediates of primary LP products were accumulated in lens within early periods of cataract development but the end LP products were mainly found at the late steps of cataract formation. Accumulation of the LP products was not distinctly different in cataracts with various clinical manifestations but similar in the level of maturation, thus indicating that lipid peroxidation plays a universal role in the process of lens opacity. The data obtained suggest that inhibitors of free radical oxidation (antioxidants) may be employed in medicamental treatment of cataracts.

  18. Partitioning of superoxide and hydrogen peroxide production by mitochondrial respiratory complex I.

    PubMed

    Grivennikova, Vera G; Vinogradov, Andrei D

    2013-03-01

    Membrane-bound respiratory complex I in inside-out submitochondrial particles (SMP) catalyzes both superoxide and hydrogen peroxide formation in NADH- and/or succinate-supported reactions. At optimal NADH concentration (50μM), the complex I-mediated process results in a formation of two superoxide anions and H(2)O(2) as the reaction products in approximately 0.7 ratio. Almost the same ratio is found for purified complex I (0.6) and for the aerobic succinate-supported reverse electron transfer reaction. Superoxide production is depressed at high, more physiologically relevant NADH concentrations, whereas hydrogen peroxide formation is insensitive to the elevated level of NADH. The rates of H(2)O(2) formation at variable NAD(+)/NADH ratios satisfactorily fit the Nernst equation for a single reactive two-electron donor component equilibrated with ambient midpoint redox potential of -347mV (0.13 NAD(+)/NADH ratio, pH 8.0). Half-maximal superoxide production rate proceeds at significantly higher NAD(+)/NADH ratio (0.33). Guanidine strongly stimulates NADH-supported hydrogen peroxide and superoxide production at any NADH concentration and activates NADH:ferricyanide and inhibits NADH:hexaammineruthenium (III) reductase activities while showing no effects on NADH oxidase of SMP. In the low range of NADH concentration, superoxide production rate shows a simple hyperbolic dependence on NADH with apparent K(m)(NADH) of 0.5μM, whereas sigmoidal dependence of hydrogen peroxide production is seen with half-maximal rate at 25μM NADH. We interpret the data as to suggest that at least two sites participate in complex I-mediated ROS generation: FMNH(-) that produces hydrogen peroxide, and an iron-sulfur center (likely N-2) that produces superoxide anion. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Hydroxyl radical production and human DNA damage induced by ferric nitrilotriacetate and hydrogen peroxide.

    PubMed

    Inoue, S; Kawanishi, S

    1987-12-15

    Reactivities of Fe3+ chelates of aminopolycarboxylic acids with DNA were investigated by the DNA-sequencing technique using 32P 5'-end-labeled DNA fragments obtained from the human c-Ha-ras-1 protooncogene, and the reaction mechanism was studied by electron spin resonance spectroscopy. Ferric nitrilotriacetate (Fe3+-NTA) plus hydrogen peroxide caused strong DNA cleavage in the presence of albumin. No or little DNA cleavage was observed with ferric chloride or Fe3+ chelates of other aminopolycarboxylic acids tested in the presence of hydrogen peroxide. The DNA cleavage by Fe3+-NTA plus hydrogen peroxide without piperidine treatment occurred at positions of every nucleotide although a specific cleavage was observed, whereas cleavages at the positions of guanine and thymine increased predominantly with piperidine treatment. Electron spin resonance studies using free radical traps demonstrated that of Fe3+ chelates of aminopolycarboxylic acids, Fe3+-NTA was the most effective catalyst in hydrogen peroxide-derived production of hydroxyl radicals under our conditions. The results suggest that Fe3+-NTA catalyzes the decomposition of hydrogen peroxide to produce hydroxyl radicals, which subsequently cause the strong base alterations of guanine and thymine, and deoxyribose-phosphate backbone breakages. The possibility that the Fe3+-NTA-induced DNA damage is the initiation and/or promotion of carcinogenesis by Fe3+-NTA is discussed.

  20. Coupling of Solar Energy to Hydrogen Peroxide Production in the Cyanobacterium Anacystis nidulans

    PubMed Central

    Roncel, Mercedes; Navarro, José A.; De la Rosa, Miguel A.

    1989-01-01

    Hydrogen peroxide production by blue-green algae (cyanobacteria) under photoautotrophic conditions is of great interest as a model system for the bioconversion of solar energy. Our experimental system was based on the photosynthetic reduction of molecular oxygen with electrons from water by Anacystis nidulans 1402-1 as the biophotocatalyst and methyl viologen as a redox intermediate. It has been demonstrated that the metabolic conditions of the algae in their different growth stages strongly influence the capacity for hydrogen peroxide photoproduction, and so the initial formation rate and net peroxide yield became maximum in the mid-log phase of growth. The overall process can be optimized in the presence of certain metabolic inhibitors such as iodoacetamide and p-hydroxymercuribenzoate, as well as by permeabilization of the cellular membrane after drastic temperature changes and by immobilization of the cells in inert supports such as agar and alginate. PMID:16347855

  1. Hydrogen peroxide production is affected by oxygen levels in mammalian cell culture.

    PubMed

    Maddalena, Lucas A; Selim, Shehab M; Fonseca, Joao; Messner, Holt; McGowan, Shannon; Stuart, Jeffrey A

    2017-11-04

    Although oxygen levels in the extracellular space of most mammalian tissues are just a few percent, under standard cell culture conditions they are not regulated and are often substantially higher. Some cellular sources of reactive oxygen species, like NADPH oxidase 4, are sensitive to oxygen levels in the range between 'normal' physiological (typically 1-5%) and standard cell culture (up to 18%). Hydrogen peroxide in particular participates in signal transduction pathways via protein redox modifications, so the potential increase in its production under standard cell culture conditions is important to understand. We measured the rates of cellular hydrogen peroxide production in some common cell lines, including C2C12, PC-3, HeLa, SH-SY5Y, MCF-7, and mouse embryonic fibroblasts (MEFs) maintained at 18% or 5% oxygen. In all instances the rate of hydrogen peroxide production by these cells was significantly greater at 18% oxygen than at 5%. The increase in hydrogen peroxide production at higher oxygen levels was either abolished or substantially reduced by treatment with GKT 137831, a selective inhibitor of NADPH oxidase subunits 1 and 4. These data indicate that oxygen levels experienced by cells in culture influence hydrogen peroxide production via NADPH oxidase 1/4, highlighting the importance of regulating oxygen levels in culture near physiological values. However, we measured pericellular oxygen levels adjacent to cell monolayers under a variety of conditions and with different cell lines and found that, particularly when growing at 5% incubator oxygen levels, pericellular oxygen was often lower and variable. Together, these observations indicate the importance, and difficulty, of regulating oxygen levels experienced by cells in culture. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Involvement of inducible nitric oxide synthase in hydroxyl radical-mediated lipid peroxidation in streptozotocin-induced diabetes

    PubMed Central

    Stadler, Krisztian; Bonini, Marcelo G.; Dallas, Shannon; Jiang, JinJie; Radi, Rafael; Mason, Ronald P.; Kadiiska, Maria B.

    2008-01-01

    Free radical production is implicated in the pathogenesis of diabetes mellitus, where several pathways and different mechanisms were suggested in the pathophysiology of the complications. In this study, we used electron paramagnetic resonance (EPR) spectroscopy combined with in vivo spin-trapping techniques to investigate the sources and mechanisms of free radical formation in streptozotocin-induced diabetic rats. Free radical production was directly detected in the diabetic bile, which correlated with lipid peroxidation in the liver and kidney. EPR spectra showed the trapping of a lipid-derived radical. Such radicals were demonstrated to be induced by hydroxyl radical through isotope labeling experiments. Multiple enzymes and metabolic pathways were examined as the potential source of the hydroxyl radicals using specific inhibitors. Neither xanthine oxidase, cytochrome P450s, the Fenton reaction, nor macrophage activation were required for the production of radical adducts. Interestingly, inducible nitric oxide synthase (apparently uncoupled) was identified as the major source of radical generation. The specific iNOS inhibitor 1400W as well as l-arginine pretreatment reduced the EPR signals to baseline levels, implicating peroxynitrite as the source of hydroxyl radical production. Applying immunological techniques, we localized iNOS overexpression in the liver and kidney of diabetic animals, which was closely correlated with the lipid radical generation and 4-hydroxynonenal-adducted protein formation, indicating lipid peroxidation. In addition, protein oxidation to protein free radicals occurred in the diabetic target organs. Taken together, our studies support inducible nitric oxide synthase as a significant source of EPR-detectable reactive intermediates, which leads to lipid peroxidation and may contribute to disease progression as well. PMID:18620046

  3. Development of a sterilizing in-place application for a production machine using Vaporized Hydrogen Peroxide.

    PubMed

    Mau, T; Hartmann, V; Burmeister, J; Langguth, P; Häusler, H

    2004-01-01

    The use of steam in sterilization processes is limited by the implementation of heat-sensitive components inside the machines to be sterilized. Alternative low-temperature sterilization methods need to be found and their suitability evaluated. Vaporized Hydrogen Peroxide (VHP) technology was adapted for a production machine consisting of highly sensitive pressure sensors and thermo-labile air tube systems. This new kind of "cold" surface sterilization, known from the Barrier Isolator Technology, is based on the controlled release of hydrogen peroxide vapour into sealed enclosures. A mobile VHP generator was used to generate the hydrogen peroxide vapour. The unit was combined with the air conduction system of the production machine. Terminal vacuum pumps were installed to distribute the gas within the production machine and for its elimination. In order to control the sterilization process, different physical process monitors were incorporated. The validation of the process was based on biological indicators (Geobacillus stearothermophilus). The Limited Spearman Karber Method (LSKM) was used to statistically evaluate the sterilization process. The results show that it is possible to sterilize surfaces in a complex tube system with the use of gaseous hydrogen peroxide. A total microbial reduction of 6 log units was reached.

  4. [THE CONTENT OF LIPIDS AND PRODUCTS OF THEIR PEROXIDATION OF RAT THYMOCYTES IN EXPERIMENTAL ULCEROGENESIS].

    PubMed

    Kovaleva, V A; Shelest, D V; Ostapchenko, L I

    2015-01-01

    The work is dedicated to the research of the content of lipids and products of their peroxidation in rats thymocytes in experimental ulceration. It was found significant increase of the content of lipid peroxidation products diene conjugates (DC), malondialdehyde (MDA), schiff base (SB) in experimental models of gastric ulcers (ethanol and stress). It was established that under ethanol gastric the contents of DC increases by 1.8 times, MDA by 2.1 and SB by 1.3 times relative to control values. Under stress model it was observed an increase in the number of DC by 2 times, MDA by 1.9 and SB by 1.3 times relative to control. When ethanol and stress ulcers cholesterol increased by 1.7 and 1.5 times, triacylglycerol by 2 and 2.3 times and fatty acids by 2.2 and 1.9 times, respectively, relative to controls. Phosphatidylethanolamine content decreases by 1.5 and 1.3 times compared to control. Also, the stress model, it was observed reduction of phosphatidylinositol by 1.3 times and increased lizofosfatydylholinu by 1.7 times compared to control. Therefore, our studies indicate quantitative changes of lipid content (neutral- and phospholipids) in rats' thymocytes under experimental (ethanol and stress) ulceration. The reason of this changes may be activation of lipid peroxidation, as shown by the increase of lipid peroxidation products' (DK, MDA, SB) content.

  5. Artificial photosynthesis for production of hydrogen peroxide and its fuel cells.

    PubMed

    Fukuzumi, Shunichi

    2016-05-01

    The reducing power released from photosystem I (PSI) via ferredoxin enables the reduction of NADP(+) to NADPH, which is essential in the Calvin-Benson cycle to make sugars in photosynthesis. Alternatively, PSI can reduce O2 to produce hydrogen peroxide as a fuel. This article describes the artificial version of the photocatalytic production of hydrogen peroxide from water and O2 using solar energy. Hydrogen peroxide is used as a fuel in hydrogen peroxide fuel cells to make electricity. The combination of the photocatalytic H2O2 production from water and O2 using solar energy with one-compartment H2O2 fuel cells provides on-site production and usage of H2O2 as a more useful and promising solar fuel than hydrogen. This article is part of a Special Issue entitled Biodesign for Bioenergetics--The design and engineering of electronc transfer cofactors, proteins and protein networks, edited by Ronald L. Koder and J.L. Ross Anderson. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Volatile fingerprints of seeds of four species indicate the involvement of alcoholic fermentation, lipid peroxidation, and Maillard reactions in seed deterioration during ageing and desiccation stress.

    PubMed

    Colville, Louise; Bradley, Emma L; Lloyd, Antony S; Pritchard, Hugh W; Castle, Laurence; Kranner, Ilse

    2012-11-01

    The volatile compounds released by orthodox (desiccation-tolerant) seeds during ageing can be analysed using gas chromatography-mass spectrometry (GC-MS). Comparison of three legume species (Pisum sativum, Lathyrus pratensis, and Cytisus scoparius) during artificial ageing at 60% relative humidity and 50 °C revealed variation in the seed volatile fingerprint between species, although in all species the overall volatile concentration increased with storage period, and changes could be detected prior to the onset of viability loss. The volatile compounds are proposed to derive from three main sources: alcoholic fermentation, lipid peroxidation, and Maillard reactions. Lipid peroxidation was confirmed in P. sativum seeds through analysis of malondialdehyde and 4-hydroxynonenal. Volatile production by ageing orthodox seeds was compared with that of recalcitrant (desiccation-sensitive) seeds of Quercus robur during desiccation. Many of the volatiles were common to both ageing orthodox seeds and desiccating recalcitrant seeds, with alcoholic fermentation forming the major source of volatiles. Finally, comparison was made between two methods of analysis; the first used a Tenax adsorbent to trap volatiles, whilst the second used solid phase microextraction to extract volatiles from the headspace of vials containing powdered seeds. Solid phase microextraction was found to be more sensitive, detecting a far greater number of compounds. Seed volatile analysis provides a non-invasive means of characterizing the processes involved in seed deterioration, and potentially identifying volatile marker compounds for the diagnosis of seed viability loss.

  7. Production of Hydrogen Peroxide in Groundwater at Rifle, Colorado.

    PubMed

    Yuan, Xiu; Nico, Peter S; Huang, Xiang; Liu, Tongxu; Ulrich, Craig; Williams, Kenneth H; Davis, James A

    2017-07-18

    The commonly held assumption that photodependent processes dominate H2O2 production in natural waters has been recently questioned. Here, we present evidence for the unrecognized and light-independent generation of H2O2 in groundwater of an alluvial aquifer adjacent to the Colorado River near Rifle, CO. In situ detection using a sensitive chemiluminescent method suggests H2O2 concentrations ranging from lower than the detection limit (<1 nM) to 54 nM along the vertical profiles obtained at various locations across the aquifer. Our results also suggest dark formation of H2O2 is more likely to occur in transitional redox environments where reduced elements (e.g., reduced metals and NOM) meet oxygen, such as oxic-anoxic interfaces. A simplified kinetic model involving interactions among iron, reduced NOM, and oxygen was able to reproduce roughly many, but not all, of the features in our detected H2O2 profiles, and therefore there are other minor biological and/or chemical controls on H2O2 steady-state concentrations in such aquifer. Because of its transient nature, the widespread presence of H2O2 in groundwater suggests the existence of a balance between H2O2 sources and sinks, which potentially involves a cascade of various biogeochemically important processes that could have significant impacts on metal/nutrient cycling in groundwater-dependent ecosystems, such as wetlands and springs. More importantly, our results demonstrate that reactive oxygen species are not only widespread in oceanic and atmospheric systems but also in the subsurface domain, possibly the least understood component of biogeochemical cycles.

  8. Optimization study on the hydrogen peroxide pretreatment and production of bioethanol from seaweed Ulva prolifera biomass.

    PubMed

    Li, Yinping; Cui, Jiefen; Zhang, Gaoli; Liu, Zhengkun; Guan, Huashi; Hwang, Hueymin; Aker, Winfred G; Wang, Peng

    2016-08-01

    The seaweed Ulva prolifera, distributed in inter-tidal zones worldwide, contains a large percentage of cellulosic materials. The technical feasibility of using U. prolifera residue (UPR) obtained after extraction of polysaccharides as a renewable energy resource was investigated. An environment-friendly and economical pretreatment process was conducted using hydrogen peroxide. The hydrogen peroxide pretreatment improved the efficiency of enzymatic hydrolysis. The resulting yield of reducing sugar reached a maximum of 0.42g/g UPR under the optimal pretreatment condition (hydrogen peroxide 0.2%, 50°C, pH 4.0, 12h). The rate of conversion of reducing sugar in the concentrated hydrolysates to bioethanol reached 31.4% by Saccharomyces cerevisiae fermentation, which corresponds to 61.7% of the theoretical maximum yield. Compared with other reported traditional processes on Ulva biomass, the reducing sugar and bioethanol yield are substantially higher. Thus, hydrogen peroxide pretreatment is an effective enhancement of the process of bioethanol production from the seaweed U. prolifera. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Oxidized Docosahexaenoic Acid Species and Lipid Peroxidation Products Increase Amyloidogenic Amyloid Precursor Protein Processing.

    PubMed

    Grimm, Marcus O W; Haupenthal, Viola J; Mett, Janine; Stahlmann, Christoph P; Blümel, Tamara; Mylonas, Nadine T; Endres, Kristina; Grimm, Heike S; Hartmann, Tobias

    2016-01-01

    One of the main characteristics of Alzheimer's disease (AD) is the β-amyloid peptide (Aβ) generated by β- and γ-secretase processing of the amyloid precursor protein (APP). Previously it has been demonstrated that polyunsaturated fatty acids (PUFAs), especially docosahexaenoic acid (DHA), are associated with a reduced risk of AD caused by decreased Aβ production. However, in epidemiological studies and nutritional approaches, the outcomes of DHA-dependent treatment were partially controversial. PUFAs are very susceptible to reactive oxygen species and lipid peroxidation, which are increased during disease pathology. In line with published results, lipid peroxidation was elevated in human postmortem AD brains; especially 4-hydroxy-nonenal (HNE) was increased. To investigate whether lipid peroxidation is only a consequence or might also influence the processes leading to AD, we analyzed 7 different oxidized lipid species including 5 oxidized DHA derivatives and the lipid peroxidation products of ω-3 and ω-6 PUFAs, HNE and 4-hydroxy-hexenal, in human neuroblastoma cells and mouse mixed cortical neurons. In the presence of oxidized lipids Aβ and soluble β-secreted APP levels were elevated, whereas soluble α-secreted APP was decreased, suggesting a shift from the nonamyloidogenic to the amyloidogenic pathway of APP processing. Furthermore, β- and γ-secretase activity was increased by oxidized lipids via increased gene expression and additionally by a direct effect on β-secretase activity. Importantly, only 1% oxidized DHA was sufficient to revert the protective effect of DHA and to significantly increase Aβ production. Therefore, our results emphasize the need to prevent DHA from oxidation in nutritional approaches and might help explain the divergent results of clinical DHA studies.

  10. Methods and apparatus for the on-site production of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Buschmann, Wayne E. (Inventor); James, Patrick I. (Inventor)

    2010-01-01

    Methods, apparatus, and applications for the on-site production of hydrogen peroxide are described. An embodiment of the apparatus comprises at least one anolyte chamber coupled to at least one anode, at least one catholyte chamber, wherein the at least one catholyte chamber is coupled to at least one cathode, at least one anode membrane and at least one cathode membrane, wherein the anode membrane is adjacent to the at least one anode, wherein the cathode membrane is adjacent to the at least one cathode, at least one central chamber disposed between the at least one anolyte chamber and the at least one catholyte chamber. Hydrogen peroxide is produced by reduction of an oxygen-containing gas at the cathode.

  11. THE PRODUCTION OF ORGANIC PEROXIDES OF VERY HIGH BIOLOGICAL EFFECTIVENESS BY IRRADIATION OF AGAR WITH HIGH DOSES(in German)

    SciTech Connect

    Sommermeyer, K.; Magnus, H.

    1962-01-01

    Irradiation of agars with alpha particles, ultraviolet radiation, and x rays for the production of organic peroxides was carried out to study the oxygen effect in radiation injuries to Bact. coli cells. (M.C.G.)

  12. Copper peroxide

    NASA Technical Reports Server (NTRS)

    Moser, L.

    1988-01-01

    A number of oxidizing agents, including chlorine, bromine, ozone and other peroxides, were allowed to act on copper solutions with the intention of forming copper peroxide. The only successful agent appears to be hydrogen peroxide. It must be used in a neutral 50 to 30 percent solution at a temperature near zero. Other methods described in the literature apparently do not work. The excess of hydrogen must be quickly sucked out of the brown precipitate, which it is best to wash with alcohol and ether. The product, crystalline under a microscope, can be analyzed only approximately. It approaches the formula CuO2H2O. In alkaline solution it appears to act catalytically in causing the decomposition of other peroxides, so that Na2O2 cannot be used to prepare it. On the addition of acids the H2O2 is regenerated. The dry substance decomposes much more slowly than the moist but is not very stable.

  13. Advanced oxidation protein products are more related to metabolic syndrome components than biomarkers of lipid peroxidation.

    PubMed

    Venturini, Danielle; Simão, Andréa Name Colado; Dichi, Isaias

    2015-09-01

    Although advanced oxidation protein products (AOPPs) have been reported as the most appropriate parameter for determination of oxidative stress in patients with metabolic syndrome (MetS), a direct comparison between protein and lipid peroxidation has not been performed yet. The aim of this study was to compare protein peroxidation with lipid peroxidation measured by 2 different methodologies (tert-butyl hydroperoxide-initiated chemiluminescence and ferrous oxidation-xylenol orange assay). The hypothesis of this study was that AOPPs would be more related to MetS than to oxidative markers of lipid peroxidation. This cross-sectional study evaluated 76 patients with MetS and 20 healthy subjects. Prooxidant-antioxidant index (PAI) assessed as AOPP/total radical-trapping antioxidant parameter ratio progressively increased (P < .05) according to the number of MetS components, whereas AOPPs and total radical-trapping antioxidant parameter increased (P < .05) when 5 components were compared with 3 components. Spearman test showed a positive correlation between AOPPs and waist circumference (r = 0.318, P < .01), fasting glucose (r = 0.250, P < .05), homeostasis model assessment insulin resistance (r = 0.043, P < .01), triacylglycerol (r = 0.713, P < .0001), highly sensitive C-reactive protein (r = 0.275, P < .05), and uric acid (r = 0.356, P < .01), whereas there was an inverse correlation with high-density lipoprotein cholesterol (r = -0.399, P < .001). Prooxidant-antioxidant index demonstrated a positive correlation with waist circumference (r = 0.386, P < .01), fasting glucose (r = 0.388, P < .01), fasting insulin (r = 0.344, P < .05), homeostasis model assessment insulin resistance (r = 0.519, P < .001), triacylglycerol (r = 0.687, P < .0001), highly sensitive C-reactive protein (r = 0.278, P < .05), and uric acid (r = 0.557, P < .0001), whereas there was an inverse correlation with high-density lipoprotein cholesterol (r = -0.480, P < .0001). In conclusion, protein

  14. The ozonation of unsaturated fatty acids: Aldehydes and hydrogen peroxide as products and possible mediators of ozone toxicity

    SciTech Connect

    Pryor, W.A.; Das, B.; Church, D.F. )

    1991-05-01

    The products of the reactions of ozone with aqueous emulsions of unsaturated fatty acids and with liposomes made from phosphatidylcholine esters were characterized. Ozonolysis of emulsions of methyl oleate yields approximately 1 mol of hydrogen peroxide and 2 mol of aldehydes per mole of ozone used and fatty acid reacted. That is, the net equation that occurs is RCH = CHR' + O3 + H2O----RCHO + R'CHO + H2O2 . Ozonolysis of emulsions of oleic, linoleic, linolenic, and arachidonic acids gives 1 mol of hydrogen peroxide per mole of ozone used. Only very low yields (less than 5%) of reducible materials other than hydrogen peroxide are observed, suggesting that the yields of organic peroxidic materials, including Criegee ozonides and lipid hydroperoxides, are small. Ozonolysis of rat erythrocyte ghost membranes and rat bronchoalveolar lavage also gives significant yields (about 50%) of hydrogen peroxide based on the moles of ozone consumed. Reactions of ozone with bovine serum albumin, glutathione, and glucose do not produce hydrogen peroxide, implying that the hydrogen peroxide formed during the ozonation of biological materials arises almost exclusively from ozone/olefin reactions. Hydrogen peroxide and aldehydes are suggested to be important mediators of the modifications observed in both the lung and extrapulmonary tissues when ozone is inhaled.

  15. Penetration of hydrogen peroxide and degradation rate of different bleaching products.

    PubMed

    Marson, F C; Gonçalves, R S; Silva, C O; Cintra, L T Â; Pascotto, R C; Santos, P H Dos; Briso, A L F

    2015-01-01

    This study's aim was to evaluate the degradation rate of hydrogen peroxide (H2O2) and to quantify its penetration in tooth structure, considering the residence time of bleaching products on the dental enamel. For this study, bovine teeth were randomly divided according to the bleaching product received: Opalescence Xtra Boost 38%, White Gold Office 35%, Whiteness HP Blue 35%, Whiteness HP Maxx 35%, and Lase Peroxide Sensy 35%. To analyze the degradation of H2O2, the titration of bleaching agents with potassium permanganate was used, while the penetration of H2O2 was measured via spectrophotometric analysis of the acetate buffer solution, collected from the artificial pulp chamber. The analyses were performed immediately as well as 15 minutes, 30 minutes, and 45 minutes after product application. The data of degradation rate of H2O2 were submitted to analysis of variance (ANOVA) and Tukey tests, while ANOVA and Fisher tests were used for the quantification of H2O2, at the 5% level. The results showed that all products significantly reduced the concentration of H2O2 activates at the end of 45 minutes. It was also verified that the penetration of H2O2 was enhanced by increasing the residence time of the product on the tooth surface. It was concluded that the bleaching gels retained substantial concentrations of H2O2 after 45 minutes of application, and penetration of H2O2 in the dental structure is time-dependent.

  16. A Comparison between Lime and Alkaline Hydrogen Peroxide Pretreatments of Sugarcane Bagasse for Ethanol Production

    NASA Astrophysics Data System (ADS)

    Rabelo, Sarita C.; Filho, Rubens Maciel; Costa, Aline C.

    Pretreatment procedures of sugarcane bagasse with lime (calcium hydroxide) or alkaline hydrogen peroxide were evaluated and compared. Analyses were performed using 2 × 2 × 2 factorial designs, with pretreatment time, temperature, and lime loading and hydrogen peroxide concentration as factors. The responses evaluated were the yield of total reducing sugars (TRS) and glucose released from pretreated bagasse after enzymatic hydrolysis. Experiments were performed using the bagasse as it comes from an alcohol/ sugar factory and bagasse in the size range of 0.248 to 1.397 mm (12-60 mesh). The results show that when hexoses and pentoses are of interest, lime should be the pretreatment agent chosen, as high TRS yields are obtained for nonscreened bagasse using 0.40 g lime/g dry biomass at 70 °C for 36 h. When the product of interest is glucose, the best results were obtained with lime pretreatment of screened bagasse. However, the results for alkaline peroxide and lime pretreatments of nonscreened bagasse are not very different.

  17. The expression and function of vascular endothelial growth factor in retinal pigment epithelial (RPE) cells is regulated by 4-hydroxynonenal (HNE) and glutathione S-transferaseA4-4

    SciTech Connect

    Vatsyayan, Rit; Lelsani, Poorna Chandra Rao; Chaudhary, Pankaj

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer Low concentration of HNE (0.1-1.0 {mu}M) induced secretion of VEGF in RPE cells. Black-Right-Pointing-Pointer VEGF secreted medium of RPE cells promoted proliferation of endothelial cells. Black-Right-Pointing-Pointer VEGFR2 expression was attenuated with increasing concentrations of HNE. Black-Right-Pointing-Pointer These effects of HNE could be blocked by the over expression of GSTA4-4 in cells. -- Abstract: It is well established that 4-hydroxynonenal (HNE) plays a major role in oxidative stress-induced signaling and the toxicity of oxidants. Surprisingly our recent studies also demonstrate that low levels of HNE generated during oxidative stress promote cell survival mechanisms and proliferation. Since the expression andmore » secretion of VEGF is known to be affected by Oxidative stress, during present studies, we have examined dose dependent effect of HNE on VEGF expression and secretion in a model of retinal pigment epithelial (RPE) cells in culture. Results of these studies showed that while inclusion of 0.1 {mu}M HNE in the medium caused increased secretion of VEGF, its secretion and expression was significantly suppressed in the presence of >5 {mu}M HNE in the media. These concentration dependent hormetic effects of HNE on VEGF secretion could be blocked by the over expression of GSTA4-4 indicating that these effects were specifically attributed to HNE and regulated by GSTA4-4. VEGF secreted into the media showed angiogenic properties as indicated by increased migration and tube formation of HUVEC in matrigel when grown in media from RPE cells treated with 1 {mu}M HNE. The corresponding media from GSTA4-4 over expressing RPE cells had no effect on migration and tube formation of HUVEC in matrigel. These results are consistent with earlier studies showing that at low concentrations, HNE promotes proliferative mechanisms and suggest that HNE induces VEGF secretion from RPE cells that acts in a paracrine fashion to

  18. Mutagenicity of ω-3 fatty acid peroxidation products in the Ames test.

    PubMed

    Grúz, Petr; Shimizu, Masatomi; Sugiyama, Kei-Ichi; Honma, Masamitsu

    2017-07-01

    Polyunsaturated fatty acids (PUFA) represent one of the main building blocks of cellular membranes and their varying composition impacts lifespan as well as susceptibility to cancer and other degenerative diseases. Increased intake of ω-3 PUFA is taught to compensate for the abundance of ω-6 PUFA in modern human diet and prevent cardiocirculatory diseases. However, highly unsaturated PUFA of marine and seed origin easily oxidize to aldehydic products which form DNA adducts. With increased PUFA consumption it is prudent to re-evaluate ω-3 PUFA safety and the genotoxic hazards of their metabolites. We have used the standard Ames test to examine the mutagenicity of 2 hexenals derived from lipid peroxidation of the common ω-3 PUFA in human diet and tissues. Both 4-hydroxyhexenal and 2-hexenal derived from the ω-3 docosahexaenoic and α-linolenic acid, respectively, induced base substitutions in the TA104 and TA100 Ames strains in a dose dependent manner. Their mutagenicity was dependent on the Y-family DNA polymerase RI and they did not induce other types of mutations such as the -2 and -1 frameshifts in the TA98 and TA97 strains. Our results expand previous findings about the mutagenicity of related ω-3 peroxidation product 4-oxohexenal and raise alert that overuse of ω-3 rich oils may have adverse effect on genome stability. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Sensitivity of plant mitochondrial terminal oxidases to the lipid peroxidation product 4-hydroxy-2-nonenal (HNE)

    PubMed Central

    2005-01-01

    We have investigated the effect of the lipid peroxidation product, HNE (4-hydroxy-2-nonenal), on plant mitochondrial electron transport. In mitochondria isolated from Arabidopsis thaliana cell cultures, HNE inhibited succinate-dependent oxygen consumption via the Aox (alternative oxidase), but had minimal effect on respiration via Cox (cytochrome c oxidase). Maximal Cox activity, measured with reduced cytochrome c as substrate, was only slightly inhibited by high concentrations of HNE, at which Aox was completely inhibited. Incubation with HNE prevented dimerization of the Aox protein, suggesting that one site of modification was the conserved cysteine residue involved in dimerization and activation of this enzyme (CysI). However, a naturally occurring isoform of Aox lacking CysI and unable to be dimerized, LeAox1b from tomato (Lycopersicon esculentum), was equally sensitive to HNE inhibition, showing that other amino acid residues in Aox also interact with HNE. The presence of HNE in vivo in Arabidopsis cell cultures was also investigated. Induction of oxidative stress in the cell cultures by the addition of hydrogen peroxide, antimycin A or menadione, caused a significant increase in hydroxyalkenals (of which HNE is the most prominent). Western blotting of mitochondrial proteins with antibodies against HNE adducts, demonstrated significant modification of proteins during these treatments. The implications of these results for the response of plants to reactive oxygen species are discussed. PMID:15689186

  20. Aminoguanidine inhibits aortic hydrogen peroxide production, VSMC NOX activity and hypercontractility in diabetic mice

    PubMed Central

    2009-01-01

    Background Dysfunctionally uncoupled endothelial nitric oxide synthase (eNOS) is involved in producing reactive oxygen species (ROS) in the diabetic endothelium. The present study investigated whether anti-diabetes drug Aminoguanidine (AG) has any effect on eNOS function and vascular oxidant stress. Methods and Results Blood glucose levels were increased to 452.0 ± 15.1 mg/dl in STZ-treated male C57BL/6J mice (148.4 ± 3.2 mg/dl in untreated controls). Aortic productions of NO• and O2•- were measured specifically and sensitively using electron spin resonance. Diabetic mice had a marked increase in aortic O2•- production. Aortic hydrogen peroxide (H2O2) production was also increased in diabetic aortas and significantly attenuated by AG. AG however had only a marginal effect in reducing aortic O2•- production, which corresponded to a minimal effect in improving aortic nitric oxide (NO•) bioavailability. The endothelium-dependent vasodilatation however was modestly but significantly improved by AG, likely consequent to AG-induced reduction in hyper-contractility. NAD(P)H oxidase (NOX)-dependent O2•- production was completely attenuated by AG in endothelium-denuded diabetic aortas. Conclusion In summary, despite that AG is not an effective eNOS recoupling agent presumably consequent to its ineffectiveness in preventing endothelial NOX activation, it is inhibitory of aortic H2O2 production, VSMC NOX activity, and hypercontractility in diabetes. PMID:20040119

  1. Epidermal growth factor-induced hydrogen peroxide production is mediated by dual oxidase 1.

    PubMed

    Sirokmány, Gábor; Pató, Anna; Zana, Melinda; Donkó, Ágnes; Bíró, Adrienn; Nagy, Péter; Geiszt, Miklós

    2016-08-01

    Stimulation of mammalian cells by epidermal growth factor (EGF) elicits complex signaling events, including an increase in hydrogen peroxide (H2O2) production. Understanding the significance of this response is limited by the fact that the source of EGF-induced H2O2 production is unknown. Here we show that EGF-induced H2O2 production in epidermal cell lines is dependent on the agonist-induced calcium signal. We analyzed the expression of NADPH oxidase isoforms and found both A431 and HaCaT cells to express the calcium-sensitive NADPH oxidase, Dual oxidase 1 (Duox1) and its protein partner Duox activator 1 (DuoxA1). Inhibition of Duox1 expression by small interfering RNAs eliminated EGF-induced H2O2 production in both cell lines. We also demonstrate that H2O2 production by Duox1 leads to the oxidation of thioredoxin-1 and the cytosolic peroxiredoxins. Our observations provide evidence for a new signaling paradigm in which changes of intracellular calcium concentration are transformed into redox signals through the calcium-dependent activation of Duox1. Copyright © 2016. Published by Elsevier Inc.

  2. The apparent quorum-sensing inhibitory activity of pyrogallol is a side effect of peroxide production.

    PubMed

    Defoirdt, Tom; Pande, Gde Sasmita Julyantoro; Baruah, Kartik; Bossier, Peter

    2013-06-01

    There currently is more and more interest in the use of natural products, such as tea polyphenols, as therapeutic agents. The polyphenol compound pyrogallol has been reported before to inhibit quorum-sensing-regulated bioluminescence in Vibrio harveyi. Here, we report that the addition of 10 mg · liter(-1) pyrogallol protects both brine shrimp (Artemia franciscana) and giant river prawn (Macrobrachium rosenbergii) larvae from pathogenic Vibrio harveyi, whereas the compound showed relatively low toxicity (therapeutic index of 10). We further demonstrate that the apparent quorum-sensing-disrupting activity is a side effect of the peroxide-producing activity of this compound rather than true quorum-sensing inhibition. Our results emphasize that verification of minor toxic effects by using sensitive methods and the use of appropriate controls are essential when characterizing compounds as being able to disrupt quorum sensing.

  3. The Apparent Quorum-Sensing Inhibitory Activity of Pyrogallol Is a Side Effect of Peroxide Production

    PubMed Central

    Pande, Gde Sasmita Julyantoro; Baruah, Kartik; Bossier, Peter

    2013-01-01

    There currently is more and more interest in the use of natural products, such as tea polyphenols, as therapeutic agents. The polyphenol compound pyrogallol has been reported before to inhibit quorum-sensing-regulated bioluminescence in Vibrio harveyi. Here, we report that the addition of 10 mg · liter−1 pyrogallol protects both brine shrimp (Artemia franciscana) and giant river prawn (Macrobrachium rosenbergii) larvae from pathogenic Vibrio harveyi, whereas the compound showed relatively low toxicity (therapeutic index of 10). We further demonstrate that the apparent quorum-sensing-disrupting activity is a side effect of the peroxide-producing activity of this compound rather than true quorum-sensing inhibition. Our results emphasize that verification of minor toxic effects by using sensitive methods and the use of appropriate controls are essential when characterizing compounds as being able to disrupt quorum sensing. PMID:23545532

  4. Concurrent calcium peroxide pretreatment and wet storage of water hyacinth for fermentable sugar production.

    PubMed

    Cheng, Yu-Shen; Chen, Kuan-Yu; Chou, Tzung-Han

    2015-01-01

    In the present study, a novel concurrent process of pretreatment and wet storage was developed and investigated by applying calcium peroxide for preservation and conversion of fresh water hyacinth biomass to fermentable sugars. The effects of CaO2 loading concentration and moisture content on the lignin reduction, carbohydrate preservation and enzymatic saccharification of water hyacinth biomass were evaluated by experimental design using a response surface methodology. The data showed that the concurrent process could conserve 70% carbohydrates and remove 40% lignin from biomass of water hyacinth at the best condition in this study. The enzymatic digestibility and reducing sugar yield from the best condition of concurrent process were around 93% and 325mg/g (dry weight) of fresh biomass, respectively. The result suggested that the concurrent process developed in this work could be a potential alternative to consolidate the pretreatment and storage of aquatic plant biomass for fermentable sugar production. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. [Dipeptide nootropic agent GVS-111 prevents accumulation of the lipid peroxidation products during immobilization].

    PubMed

    Lysenko, A V; Uskova, N I; Ostrovskaia, R U; Gudasheva, T A; Voronina, T A

    1997-01-01

    Immobilization of rats in a narrow plastic chamber for 24 h caused a sharp increase in the level of diene conjugates and the content of schiff bases in the synaptosomes of the brain cortex as well as accumulation of extraerythrocytic hemoglobin in blood serum. The dipeptide nootropic agent GVS-111 (ethyl ether of phenylacetylprolylglycine), when administered 15 and particularly 60 min before immobilization reduced the accumulation of these products of lipid peroxidation in the brain and blood. GVS-111 demonstrated these signs of its antioxidant effect after a single i.p. injection in doses of 0.12 and 0.5 mg/kg. Pyracetam produced a similar effect on the listed parameters in injection in a dose of 300 mg/kg for three successive days. The protective effect of the new pyracetam dipeptide analog GVS-111 in relation to activation of free-radical processes induced by immobilization is additional proof of the antistress action of this dipeptide.

  6. Production of Hydroxyl Radical via the Activation of Hydrogen Peroxide by Hydroxylamine.

    PubMed

    Chen, Liwei; Li, Xuchun; Zhang, Jing; Fang, Jingyun; Huang, Yanmin; Wang, Ping; Ma, Jun

    2015-09-01

    The production of the hydroxyl radical (HO·) is important in environmental chemistry. This study reports a new source of HO· generated solely from hydrogen peroxide (H2O2) activated by hydroxylamine (HA). Electron paramagnetic resonance analysis and the oxidation of a HO· probe, benzoic acid, were used to confirm the production of HO·. The production of HO· increased with increasing concentrations of either HA or H2O2 as well as decreasing pH. The second-order rate constant for the reaction was (2.2 ± 0.2) × 10(-4) M(-1) s(-1). HO· was probably produced in two steps: the activation of H2O2 by protonated HA and then reaction between the H2O2 and the intermediate protonated aminoxyl radical generated in the first step. Such a two-step oxidation can possibly be ascribed to the ionizable hydroxyl moiety in the molecular structure of HA, as is suggested by comparing the reactivity of a series of HA derivatives in HO· production. The results shed light on a previously unknown source of HO· formation, which broadens the understanding of its role in environmental processes.

  7. Endogenous hydrogen peroxide production in the epithelium of the developing embryonic lens

    PubMed Central

    Basu, Subhasree; Rajakaruna, Suren; Dickinson, Bryan C.; Chang, Christopher J.

    2014-01-01

    Purpose Hydrogen peroxide (H2O2) is an endogenously produced reactive oxygen species (ROS) present in a variety of mammalian systems. This particular ROS can play dichotomous roles, being beneficial in some cases and deleterious in others, which reflects the level and location of H2O2 production. While much is known about the redox regulation of ROS by antioxidant and repair systems in the lens, little is known about the endogenous production of H2O2 in embryonic lens tissue or the physiologic relevance of endogenous H2O2 to lens development. This gap in knowledge exists primarily from a lack of reagents that can specifically detect endogenous H2O2 in the intact lens. Here, using a recently developed chemoselective fluorescent boronate probe, peroxyfluor-6 acetoxymethyl ester (PF6-AM), which selectively detects H2O2 over related ROS, we examined the endogenous H2O2 signals in the embryonic lens. Methods Embryonic day 10 chick whole lenses in ex vivo organ culture and lens epithelial cells in primary culture were loaded with the H2O2 probe PF6-AM. To determine the relationship between localization of mitochondria with active membrane potential and the region of H2O2 production in the lens, cells were exposed to the mitochondrial probe MitoTracker Red CMXRos together with PF6-AM. Diphenyleneiodonium (DPI), a flavin inhibitor that blocks generation of intracellular ROS production, was used to confirm that the signal from PF6-AM was due to endogenous ROS production. All imaging was performed by live confocal microscopy. Results PF6-AM detected endogenous H2O2 in lens epithelial cells in whole lenses in ex vivo culture and in lens epithelial cells grown in primary culture. No endogenous H2O2 signal could be detected in differentiating lens fiber cells with this probe. Treatment with DPI markedly attenuated the fluorescence signal from the peroxide-specific probe PF6-AM in the lens epithelium, suggesting that basal generation of ROS occurs in this region. The lens

  8. Chemistry of peroxide compounds

    NASA Technical Reports Server (NTRS)

    Volnov, I. I.

    1981-01-01

    The history of Soviet research from 1866 to 1967 on peroxide compounds is reviewed. This research dealt mainly with peroxide kinetics, reactivity and characteristics, peroxide production processes, and more recently with superoxides and ozonides and emphasis on the higher oxides of group 1 and 2 elements. Solid state fluidized bed synthesis and production of high purity products based on the relative solubilities of the initial, intermediate, and final compounds and elements in liquid ammonia are discussed.

  9. Moderate intervention with carotenoid-rich vegetable products reduces lipid peroxidation in men.

    PubMed

    Bub, A; Watzl, B; Abrahamse, L; Delincée, H; Adam, S; Wever, J; Müller, H; Rechkemmer, G

    2000-09-01

    Because of their antioxidant properties, carotenoids may have beneficial effects in preventing cancer and cardiovascular disease. However, in humans consuming carotenoid-rich vegetables, data concerning the antioxidant effects of carotenoids are rather scarce. A human intervention trial was conducted, therefore, to determine whether a moderately increased consumption of carotenoid-rich vegetables would influence the antioxidant status in 23 healthy men. This short-term feeding study lasted 8 wk during which the men consumed a low carotenoid diet. A 2-wk low carotenoid period was followed by daily consumption of 330 mL tomato juice, then by 330 mL carrot juice and then by 10 g of spinach powder, each for 2 wk. Antioxidant status [water-soluble antioxidants in serum, ferric reducing ability of plasma (FRAP) and antioxidant enzyme activities] and lipid peroxidation (plasma malondialdehyde and ex vivo oxidation of LDL) were determined. In a subgroup of 10 men, lipoprotein carotenoids were measured. The consumption of carotenoid-rich vegetables significantly increased selected carotenoids in lipoproteins but had only minor effects on their relative distribution pattern. Tomato juice consumption reduced plasma thiobarbituric acid reactive substances (TBARS) by 12% (P: < 0.05) and lipoprotein oxidizability in terms of an increased lag time (18%, P: < 0.05). Carrot juice and spinach powder had no effect on lipid peroxidation. Water-soluble antioxidants, FRAP, glutathione peroxidase and reductase activities did not change during any study period. In evaluating the low carotenoid diet, we conclude that the additional consumption of carotenoid-rich vegetable products enhanced lipoprotein carotenoid concentrations, but only tomato juice reduced LDL oxidation in healthy men.

  10. Modulation of hydrogen peroxide production in cellular systems by low level magnetic fields.

    PubMed

    Martino, Carlos F; Castello, Pablo R

    2011-01-01

    Increased generation of reactive oxygen species (ROS) and an altered redox status have long been observed in cancer cells, suggesting that ROS might be involved in the development of these cells. However, recent studies suggest that inducing an excess of ROS in cancer cells can be exploited for therapeutic benefits. Cancer cells in advanced stage tumors frequently exhibit multiple genetic alterations and high oxidative stress, suggesting that it might be possible to preferentially modulate the development of these cells by controlling their ROS production. Low levels of ROS are also important for the development and survival of normal cells. In this manuscript, we present data on the influence of the suppression of the Earth's magnetic field (low level magnetic fields or LLF) which magnitudes range from 0.2 µT to 2 µT on the modulation of hydrogen peroxide (H(2)O(2)) in human fibrosarcoma cancer cell line HT1080, pancreatic AsPC-1 cancer cell line, and bovine pulmonary artery endothelial cells (PAEC) exposed to geomagnetic field (control; 45 µT-60 µT). Reduction of the Earth's magnetic field suppressed H(2)O(2) production in cancer cells and PAEC. The addition of catalase and superoxide dismutase (SOD) mimetic MnTBAP inhibited the magnetic field effect. Modulating ROS production by magnetic fields may open new venues of biomedical research and therapeutic strategies.

  11. [Antioxidant enzymes and lipid peroxidation products in patients with pulmonary tuberculosis].

    PubMed

    Golubović, Slavica; Stanković, Ivana; Ristić, Lidija; Cosić, Vladan; Dordević, Ivanka; Radović, Milan

    2010-01-01

    A lot of studies have dealt with the oxidative stress in pulmonary diseases, and some of them with tuberculosis as well. The aim of this study was to examine the antioxidant enzyme level (superoxide dismutase, glutathione peroxidase, catalase) and the lipid peroxidation products in patients with tuberculosis. Forty patients with tuberculosis were included in the study. The examined parameters were measured before and three weeks after the beginning of the antituberculosis treatment (group I). The control group included 40 healthy persons (group II). The superoxide dismutase level was significantly lower in group I in both measurements (p < 0.001 and p < 0.01) in relation to group II, but there were no significant changes in its level during the therapy. During the treatment, the glutation peroxidase level significantly increased (p < 0.05), and in relation to group II, its level was significantly lower in both measurements in group I (p < 0.001 and p < 0.001). The catalase level significantly increased during the treatment, but there was no significant difference in relation to group II level. There was no significant difference in relation to the lipid peroxidase products between the groups. Our study group had reduced antioxidant enzyme level and some of them showed significant improvement during the treatment. The lipid peroxidase product level was stable. In patients with tuberculosis the antioxidative status is lower and its level and possible development of the oxidative stress depend on the disease severity.

  12. 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. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Production of hydrogen peroxide in the atmosphere of a Snowball Earth and the origin of oxygenic photosynthesis.

    PubMed

    Liang, Mao-Chang; Hartman, Hyman; Kopp, Robert E; Kirschvink, Joseph L; Yung, Yuk L

    2006-12-12

    During Proterozoic time, Earth experienced two intervals with one or more episodes of low-latitude glaciation, which are probable "Snowball Earth" events. Although the severity of the historical glaciations is debated, theoretical "hard Snowball" conditions are associated with the nearly complete shutdown of the hydrological cycle. We show here that, during such long and severe glacial intervals, a weak hydrological cycle coupled with photochemical reactions involving water vapor would give rise to the sustained production of hydrogen peroxide. The photochemical production of hydrogen peroxide has been proposed previously as the primary mechanism for oxidizing the surface of Mars. During a Snowball, hydrogen peroxide could be stored in the ice; it would then be released directly into the ocean and the atmosphere upon melting and could mediate global oxidation events in the aftermath of the Snowball, such as that recorded in the Fe and Mn oxides of the Kalahari Manganese Field, deposited after the Paleoproterozoic low-latitude Makganyene glaciation. Low levels of peroxides and molecular oxygen generated during Archean and earliest Proterozoic non-Snowball glacial intervals could have driven the evolution of oxygen-mediating and -using enzymes and thereby paved the way for the eventual appearance of oxygenic photosynthesis.

  14. Seawater usable for production and consumption of hydrogen peroxide as a solar fuel.

    PubMed

    Mase, Kentaro; Yoneda, Masaki; Yamada, Yusuke; Fukuzumi, Shunichi

    2016-05-04

    Hydrogen peroxide (H2O2) in water has been proposed as a promising solar fuel instead of gaseous hydrogen because of advantages on easy storage and high energy density, being used as a fuel of a one-compartment H2O2 fuel cell for producing electricity on demand with emitting only dioxygen (O2) and water. It is highly desired to utilize the most earth-abundant seawater instead of precious pure water for the practical use of H2O2 as a solar fuel. Here we have achieved efficient photocatalytic production of H2O2 from the most earth-abundant seawater instead of precious pure water and O2 in a two-compartment photoelectrochemical cell using WO3 as a photocatalyst for water oxidation and a cobalt complex supported on a glassy-carbon substrate for the selective two-electron reduction of O2. The concentration of H2O2 produced in seawater reached 48 mM, which was high enough to operate an H2O2 fuel cell.

  15. Active macromolecules of honey form colloidal particles essential for honey antibacterial activity and hydrogen peroxide production.

    PubMed

    Brudzynski, Katrina; Miotto, Danielle; Kim, Linda; Sjaarda, Calvin; Maldonado-Alvarez, Liset; Fukś, Henryk

    2017-08-09

    Little is known about the global structure of honey and the arrangement of its main macromolecules. We hypothesized that the conditions in ripened honeys resemble macromolecular crowding in the cell and affect the concentration, reactivity, and conformation of honey macromolecules. Combined results from UV spectroscopy, DLS and SEM showed that the concentration of macromolecules was a determining factor in honey structure. The UV spectral scans in 200-400 nm visualized and allowed quantification of UV-absorbing compounds in the following order: dark > medium > light honeys (p < 0.0001). The high concentration of macromolecules promoted their self-assembly to micron-size superstructures, visible in SEM as two-phase system consisting of dense globules distributed in sugar solution. These particles showed increased conformational stability upon dilution. At the threshold concentration, the system underwent phase transition with concomitant fragmentation of large micron-size particles to nanoparticles in hierarchical order. Honey two-phase conformation was an essential requirement for antibacterial activity and hydrogen peroxide production. These activities disappeared beyond the phase transition point. The realization that active macromolecules of honey are arranged into compact, stable multicomponent assemblies with colloidal properties reframes our view on global structure of honey and emerges as a key property to be considered in investigating its biological activity.

  16. Seawater usable for production and consumption of hydrogen peroxide as a solar fuel

    PubMed Central

    Mase, Kentaro; Yoneda, Masaki; Yamada, Yusuke; Fukuzumi, Shunichi

    2016-01-01

    Hydrogen peroxide (H2O2) in water has been proposed as a promising solar fuel instead of gaseous hydrogen because of advantages on easy storage and high energy density, being used as a fuel of a one-compartment H2O2 fuel cell for producing electricity on demand with emitting only dioxygen (O2) and water. It is highly desired to utilize the most earth-abundant seawater instead of precious pure water for the practical use of H2O2 as a solar fuel. Here we have achieved efficient photocatalytic production of H2O2 from the most earth-abundant seawater instead of precious pure water and O2 in a two-compartment photoelectrochemical cell using WO3 as a photocatalyst for water oxidation and a cobalt complex supported on a glassy-carbon substrate for the selective two-electron reduction of O2. The concentration of H2O2 produced in seawater reached 48 mM, which was high enough to operate an H2O2 fuel cell. PMID:27142725

  17. Tailoring Microbial Electrochemical Cells for Production of Hydrogen Peroxide at High Concentrations and Efficiencies.

    PubMed

    Young, Michelle N; Links, Mikaela J; Popat, Sudeep C; Rittmann, Bruce E; Torres, César I

    2016-12-08

    A microbial peroxide producing cell (MPPC) for H 2 O 2 production at the cathode was systematically optimized with minimal energy input. First, the stability of H 2 O 2 was evaluated using different catholytes, membranes, and catalyst materials. On the basis of these results, a flat-plate MPPC fed continuously using 200 mm NaCl catholyte at a 4 h hydraulic retention time was designed and operated, producing H 2 O 2 for 18 days. H 2 O 2 concentration of 3.1 g L -1 H 2 O 2 with 1.1 Wh g -1 H 2 O 2 power input was achieved in the MPPC. The high H 2 O 2 concentration was a result of the optimum materials selected. The small energy input was largely the result of the 0.5 cm distance between the anode and cathode, which reduced ionic transport losses. However, >50 % of operational overpotentials were due to the 4.5-5 pH unit difference between the anode and cathode chambers. The results demonstrate that a MPPC can continuously produce H 2 O 2 at high concentration by selecting compatible materials and appropriate operating conditions. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. In vitro evaluation of variances between real and declared concentration of hydrogen peroxide in various tooth-whitening products.

    PubMed

    Majeed, Abdul; Farooq, Imran; Grobler, Sias R; Moola, M H

    2015-07-01

    The aim of this in vitro study was to analyze the real hydrogen peroxide (HP) concentration in various commercially available tooth-whitening products containing HP and/or carbamide peroxide (CP). Sixteen commercially available tooth-whitening products containing various concentrations of CP or HP were investigated. The products were divided into four groups: dentist-supervised home bleaching products (Group 1, n = 5), in-office bleaching products (Group 2, n = 4), over-the-counter bleaching products (Group 3, n = 3) and whitening toothpastes and rinses (Group 4, n = 4). The peroxide concentration was determined using the oxy-reduction titration method. All the reagents used in the study were of analytic grade and freshly prepared before the experiment. The HP concentration in various dentist-supervised home bleaching products and in-office bleaching products ranged from 3.02-37.08% (expected range = 3-38%). The HP concentration of over-the-counter whitening products ranged from 1.24-5.57% (expected range cannot be estimated as no concentration of active ingredient was provided). Among whitening toothpastes and rinses, Colgate Plax whitening rinse showed more than 1% HP concentration, whereas it was lower than 0.05% in other whitening toothpastes and oral rinses (expected range cannot be estimated as no active ingredient was mentioned). HP concentration of most of the professional tooth-whitening products was different from the expected concentrations, although the deviations were small and most of the products were close to the expected concentration. No concentration of active ingredient was provided for over-the-counter whitening products and no active ingredient was mentioned for whitening toothpastes and rinses.

  19. Increased production of hydrogen peroxide by peripheral blood monocytes associated with smoking exposure intensity in smokers.

    PubMed

    Tanni, Suzana E; Correa, Camila R; Angeleli, Aparecida Y; Vale, Simone A; Coelho, Liana S; Godoy, Irma

    2012-11-21

    Smoking is known to be associated with oxidative stress; however, it has not been elucidated whether the oxidative response is influenced by the intensity of smoking exposure. Evaluate the effect of smoking exposure on the secretion of hydrogen peroxide (H2O2) by the peripheral blood monocytes of smokers. A total of 25 smokers (50.3±8.8 years, 48% male) underwent the following evaluations: spirometry, pulse oximetry, body composition and total peripheral blood count. Peripheral blood monocyte (PBM) cultures were isolated and maintained, and IL-6 and TNF-α were measured in the plasma and in the supernatants of spontaneous and stimulated cultures. H2O2 was evaluated in the supernatants of the PBM cultures, and a subset of the PBM culture supernatants was stimulated with phorbol myristate acetate (PMA). We also evaluated 38 healthy controls (49.1±8.2 years, 42% male). The spontaneous and stimulated monocytes' secretion of H2O2 were statistically higher in the smokers than in the healthy controls (p<0.001). The H2O2 secretions were statistically significant higher after stimulation with PMA in both groups (p<0.001). In the multiple regression analysis, we identified a positive, statistically significant association between pack-years of smoking and the spontaneous secretion of H2O2 by PBM culture, adjusted for potential confounding variables. The association between PBM culture secretion of H2O2 and the production of TNF-α and IL-6 was not significant. We identified a positive association between higher production of H2O2 in smokers and higher smoking exposure during life. The influence of pack-years smoking may be a key modifiable factor in oxidative stress associated to smoking.

  20. Increased Production of Hydrogen Peroxide by Lactobacillus delbrueckii subsp. bulgaricus upon Aeration: Involvement of an NADH Oxidase in Oxidative Stress

    PubMed Central

    Marty-Teysset, C.; de la Torre, F.; Garel, J.-R.

    2000-01-01

    The growth of Lactobacillus delbrueckii subsp. bulgaricus (L. delbrueckii subsp. bulgaricus) on lactose was altered upon aerating the cultures by agitation. Aeration caused the bacteria to enter early into stationary phase, thus reducing markedly the biomass production but without modifying the maximum growth rate. The early entry into stationary phase of aerated cultures was probably related to the accumulation of hydrogen peroxide in the medium. Indeed, the concentration of hydrogen peroxide in aerated cultures was two to three times higher than in unaerated ones. Also, a similar shift from exponential to stationary phase could be induced in unaerated cultures by adding increasing concentrations of hydrogen peroxide. A significant fraction of the hydrogen peroxide produced by L. delbrueckii subsp. bulgaricus originated from the reduction of molecular oxygen by NADH catalyzed by an NADH:H2O2 oxidase. The specific activity of this NADH oxidase was the same in aerated and unaerated cultures, suggesting that the amount of this enzyme was not directly regulated by oxygen. Aeration did not change the homolactic character of lactose fermentation by L. delbrueckii subsp. bulgaricus and most of the NADH was reoxidized by lactate dehydrogenase with pyruvate. This indicated that NADH oxidase had no (or a very small) energetic role and could be involved in eliminating oxygen. PMID:10618234

  1. Chronic iron overload induces gender-dependent changes in iron homeostasis, lipid peroxidation and clinical course of experimental autoimmune encephalomyelitis.

    PubMed

    Ćurko-Cofek, Božena; Kezele, Tanja Grubić; Marinić, Jelena; Tota, Marin; Čizmarević, Nada Starčević; Milin, Čedomila; Ristić, Smiljana; Radošević-Stašić, Biserka; Barac-Latas, Vesna

    2016-12-01

    To analyze iron- and gender-dependent mechanisms possibly involved in pathogenesis of multiple sclerosis (MS) in this study we evaluated the effects of iron overload (IO) on iron status and lipid peroxidation processes (LPO) in tissues of female and male DA rats during chronic relapsing experimental autoimmune encephalomyelitis, a well-established MS animal model. Rats were treated by iron sucrose (75mg/kg bw/day) or with saline solution during two weeks before the sensitization with bovine brain homogenate in complete Freund's adjuvant. Clinical signs of EAE were monitored during 29 days. Serum and tissues of CNS and liver were sampled before immunization and at day 13th post immunization (during acute phase of EAE). The determination of ferritin, iron, malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE) and evaluation of histopathology were performed by ELISA, ICP spectrometry and immunohistochemistry. Results showed that IO in female EAE rats accelerated the onset of disease. In contrast, in male rats it accelerated the progression of disease and increased the mortality rate. During acute phase of EAE female IO rats sequestered more Fe in the liver, spinal cord and in the brain and produced more ferritin than male EAE rats. Male rats, however, reacted on IO by higher production of MDA or 4-HNE in the neural tissues and showed greater signs of plaque formation and gliosis in spinal cord. The data point to sexual dimorphism in mechanisms that regulate peripheral and brain iron homeostasis and imply that men and women during MS might be differentially vulnerable to exogenous iron overload. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Blending remote sensing data products to estimate photochemical production of hydrogen peroxide and superoxide in the surface ocean.

    PubMed

    Powers, Leanne C; Miller, William L

    2014-04-01

    Hydrogen peroxide (H₂O₂) and its precursor, superoxide (O₂(-)), are well-studied photochemical products that are pivotal in regulating redox transformations of trace metals and organic matter in the surface ocean. In attempts to understand the magnitude of both H₂O₂ and O₂(-) photoproduction on a global scale, we implemented a model to calculate photochemical fluxes of these products from remotely sensed ocean color and modeled solar irradiances. We generated monthly climatologies for open ocean H₂O₂ photoproduction rates using an average apparent quantum yield (AQY) spectrum determined from laboratory irradiations of oligotrophic water collected in the Gulf of Alaska. Because the formation of H₂O₂ depends on secondary thermal reactions involving O₂(-), we also implemented a temperature correction for the H₂O₂ AQY using remotely sensed sea surface temperature and an Arrhenius relationship for H₂O₂ photoproduction. Daily photoproduction rates of H₂O₂ ranged from <1 to over 100 nM per day, amounting to ∼30 μM per year in highly productive regions. When production rates were calculated without the temperature correction, maximum daily rates were underestimated by 15-25%, highlighting the importance of including the temperature modification for H₂O₂ in these models. By making assumptions about the relationship between H₂O₂ and O₂(-) photoproduction rates and O₂(-) decay kinetics, we present a method for calculating midday O₂(-) steady-state concentrations ([O₂(-)]ss) in the open ocean. Estimated [O₂(-)]ss ranged from 0.1-5 nM assuming biomolecular dismutation was the only sink for O₂(-), but were reduced to 0.1-290 pM when catalytic pathways were included. While the approach presented here provides the first global scale estimates of marine [O₂(-)]ss from remote sensing, the potential of this model to quantify O₂(-) photoproduction rates and [O₂(-)]ss will not be fully realized until the mechanisms

  3. Lead-induced increase in antioxidant enzymes and lipid peroxidation products in developing rat brain.

    PubMed

    Bokara, Kiran Kumar; Brown, Erika; McCormick, Rashidi; Yallapragada, Prabhakara Rao; Rajanna, Sharada; Bettaiya, Rajanna

    2008-02-01

    Pregnant rats were treated with 0.4% lead acetate through drinking water from 6th day of gestation and this treatment was continued till 21 post natal days (PND). Four regions of the brain namely hippocampus, cerebellum, frontal cortex and brain stem were dissected at 10, 20, 30 and 40 PND for estimation of lipid peroxidation products (LPP), catalase (CAT) and superoxide dismutase (SOD). The results indicate that there was a significant (P < 0.05) increase of LPP in exposed rats than their corresponding control at 10, 20 and 30 PND both in hippocampus and cerebellum. At PND 40, the LPP of control and exposed were found to be almost same in both the tissues indicating recovery from lead toxicity. CAT activity was significantly (P < 0.05) high in hippocampus of exposed rats up to PND 30 but up to PND 20 in cerebellum and frontal cortex. However, in brain stem, a significant (P < 0.05) increase in CAT activity was observed only at PND 10. A significant (P < 0.05) increase in SOD activity was observed up to PND 30 both in hippocampus and cerebellum on lead exposure. Frontal cortex exhibited a similar significant (P < 0.05) increase of SOD activity up to PND 20 and for brain stem up to PND 10. There was no significant change in the activity of antioxidant enzymes (CAT and SOD) and LPP in all the four brain tissues of control and exposed rats at PND 40 indicating recovery from lead-induced oxidative stress.

  4. Biological and Chemical Adaptation to Endogenous Hydrogen Peroxide Production in Streptococcus pneumoniae D39

    PubMed Central

    Lisher, John P.; Tsui, Ho-Ching Tiffany; Ramos-Montañez, Smirla; Hentchel, Kristy L.; Martin, Julia E.; Trinidad, Jonathan C.

    2017-01-01

    ABSTRACT The catalase-negative, facultative anaerobe Streptococcus pneumoniae D39 is naturally resistant to hydrogen peroxide (H2O2) produced endogenously by pyruvate oxidase (SpxB). Here, we investigate the adaptive response to endogenously produced H2O2. We show that lactate oxidase, which converts lactate to pyruvate, positively impacts pyruvate flux through SpxB and that ΔlctO mutants produce significantly lower H2O2. In addition, both the SpxB pathway and a candidate pyruvate dehydrogenase complex (PDHC) pathway contribute to acetyl coenzyme A (acetyl-CoA) production during aerobic growth, and the pyruvate format lyase (PFL) pathway is the major acetyl-CoA pathway during anaerobic growth. Microarray analysis of the D39 strain cultured under aerobic versus strict anaerobic conditions shows upregulation of spxB, a gene encoding a rhodanese-like protein (locus tag spd0091), tpxD, sodA, piuB, piuD, and an Fe-S protein biogenesis operon under H2O2-producing conditions. Proteome profiling of H2O2-induced sulfenylation reveals that sulfenylation levels correlate with cellular H2O2 production, with endogenous sulfenylation of ≈50 proteins. Deletion of tpxD increases cellular sulfenylation 5-fold and has an inhibitory effect on ATP generation. Two major targets of protein sulfenylation are glyceraldehyde-3-phosphate dehydrogenase (GapA) and SpxB itself, but targets also include pyruvate kinase, LctO, AdhE, and acetate kinase (AckA). Sulfenylation of GapA is inhibitory, while the effect on SpxB activity is negligible. Strikingly, four enzymes of capsular polysaccharide biosynthesis are sulfenylated, as are enzymes associated with nucleotide biosynthesis via ribulose-5-phosphate. We propose that LctO/SpxB-generated H2O2 functions as a signaling molecule to downregulate capsule production and drive altered flux through sugar utilization pathways. IMPORTANCE Adaptation to endogenous oxidative stress is an integral aspect of Streptococcus pneumoniae colonization and

  5. High-performance liquid chromatography method for the determination of hydrogen peroxide present or released in teeth bleaching kits and hair cosmetic products.

    PubMed

    Gimeno, Pascal; Bousquet, Claudine; Lassu, Nelly; Maggio, Annie-Françoise; Civade, Corinne; Brenier, Charlotte; Lempereur, Laurent

    2015-03-25

    This manuscript presents an HPLC/UV method for the determination of hydrogen peroxide present or released in teeth bleaching products and hair products. The method is based on an oxidation of triphenylphosphine into triphenylphosphine oxide by hydrogen peroxide. Triphenylphosphine oxide formed is quantified by HPLC/UV. Validation data were obtained using the ISO 12787 standard approach, particularly adapted when it is not possible to make reconstituted sample matrices. For comparative purpose, hydrogen peroxide was also determined using ceric sulfate titrimetry for both types of products. For hair products, a cross validation of both ceric titrimetric method and HPLC/UV method using the cosmetic 82/434/EEC directive (official iodometric titration method) was performed. Results obtained for 6 commercialized teeth whitening products and 5 hair products point out similar hydrogen peroxide contain using either the HPLC/UV method or ceric sulfate titrimetric method. For hair products, results were similar to the hydrogen peroxide content using the cosmetic 82/434/EEC directive method and for the HPLC/UV method, mean recoveries obtained on spiked samples, using the ISO 12787 standard, ranges from 100% to 110% with a RSD<3.0%. To assess the analytical method proposed, the HPLC method was used to control 35 teeth bleaching products during a market survey and highlight for 5 products, hydrogen peroxide contents higher than the regulated limit. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Can perchlorates be transformed to hydrogen peroxide (H2O2) products by cosmic rays on the Martian surface?

    NASA Astrophysics Data System (ADS)

    Crandall, Parker B.; Góbi, Sándor; Gillis-Davis, Jeffrey; Kaiser, Ralf I.

    2017-09-01

    Due to their oxidizing properties, perchlorates (ClO4-) are suggested by the planetary science community to play a vital role in the scarcity of organics on the Martian surface. However, alternative oxidation agents such as hydrogen peroxide (H2O2) have received surprisingly little attention. In this study, samples of magnesium perchlorate hexahydrate (Mg(ClO4)2 · 6H2O) were exposed to monoenergetic electrons and D2+ ions separately, sequentially, and simultaneously to probe the effects of galactic cosmic ray exposure of perchlorates and the potential incorporation of hydrogen (deuterium) into these minerals. The experiments were carried out under ultrahigh-vacuum conditions at 50 K, after which the samples were slowly heated to 300 K while the subliming products were monitored by a quadrupole mass spectrometer. In all cases, molecular oxygen (O2) was detected upon the onset of irradiation and also during the warmup phase. In case of a simultaneous D2+-electron exposure, deuterated water (D2O) and deuterium peroxide (D2O2) were also detected in the warmup phase, whereas only small amounts of D2O2 were found after an exclusive D2+ irradiation. These experiments yield the first data identifying hydrogen peroxide as a potential product in the interaction of cosmic rays with perchlorates in the Martian regolith revealing that perchlorates are capable of producing multiple oxidizing agents (O2 and D2O2) that may account for the destruction of organics on the Martian surface.

  7. Effects of ochratoxin A on some production traits, lipid peroxide and glutathione redox status of weaned piglets.

    PubMed

    Balogh, K; Hausenblasz, J; Weber, Mária; Erdélyi, Márta; Fodor, Judit; Mézes, M

    2007-12-01

    The effect of feeding ochratoxin A (OTA) contaminated diet (379.6 and 338.1 microg/kg in starter and grower diets) on production traits, lipid peroxidation and some parameters of the glutathione redox system were investigated in weaned piglets over a seven-week period. Feed intake and feed conversion ratio (FCR) did not differ significantly, but in the first phase (0-28 days) the daily weight gain was significantly lower in the piglets fed the OTA-contaminated diet. Lipid peroxidation, as measured by the amount of malondialdehyde, glutathione content and glutathione peroxidase activity, did not change significantly in the blood plasma and red blood cell haemolysate in the OTA-loaded group, while malondialdehyde content increased significantly in the liver and markedly but not significantly in the kidney of piglets fed OTA-contaminated feed. Glutathione content did not differ significantly in the studied organs of the two groups while glutathione peroxidase activity of the OTA-loaded animals was significantly lower both in the liver and in the kidney. The results suggest that the use of feed-stuffs contaminated with low levels of OTA for seven weeks did not cause marked differences in the production traits or in lipid peroxidation and amount or activity of the glutathione redox system in the blood plasma, red blood cells and kidney, while significant changes occurred in the liver homogenate.

  8. Products of binary complex compounds thermolysis: Catalysts for hydrogen peroxide decomposition

    NASA Astrophysics Data System (ADS)

    Domonov, D. P.; Pechenyuk, S. I.; Gosteva, A. N.

    2014-06-01

    Samples are obtained via the thermolysis of binary complex compounds in a hydrogen atmosphere. Their catalytic activity in hydrogen peroxide decomposition is studied. The values of the rate constants and activation energies for the catalytic reaction are estimated. The correlation between catalytic activity, composition, specific surface area ( S sp), and particle size of the samples is analyzed.

  9. Elastin aging and lipid oxidation products in human aorta.

    PubMed

    Zarkovic, Kamelija; Larroque-Cardoso, Pauline; Pucelle, Mélanie; Salvayre, Robert; Waeg, Georg; Nègre-Salvayre, Anne; Zarkovic, Neven

    2015-01-01

    Vascular aging is associated with structural and functional modifications of the arteries, and by an increase in arterial wall thickening in the intima and the media, mainly resulting from structural modifications of the extracellular matrix (ECM) components. Among the factors known to accumulate with aging, advanced lipid peroxidation end products (ALEs) are a hallmark of oxidative stress-associated diseases such as atherosclerosis. Aldehydes generated from the peroxidation of polyunsaturated fatty acids (PUFA), (4-hydroxynonenal, malondialdehyde, acrolein), form adducts on cellular proteins, leading to a progressive protein dysfunction with consequences in the pathophysiology of vascular aging. The contribution of these aldehydes to ECM modification is not known. This study was carried out to investigate whether aldehyde-adducts are detected in the intima and media in human aorta, whether their level is increased in vascular aging, and whether elastin fibers are a target of aldehyde-adduct formation. Immunohistological and confocal immunofluorescence studies indicate that 4-HNE-histidine-adducts accumulate in an age-related manner in the intima, media and adventitia layers of human aortas, and are mainly expressed in smooth muscle cells. In contrast, even if the structure of elastin fiber is strongly altered in the aged vessels, our results show that elastin is not or very poorly modified by 4-HNE. These data indicate a complex role for lipid peroxidation and in particular for 4-HNE in elastin homeostasis, in the vascular wall remodeling during aging and atherosclerosis development. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  10. Luminol-dependent chemiluminescence analysis of chitooligosaccharide-induced rapid production of hydrogen peroxide by intact wheat seedlings.

    PubMed

    Khairullin, R M; Akhmetova, I E

    2001-03-01

    The feasibility of a luminol-dependent chemiluminescence analysis of hydrogen peroxide production by intact wheat seedlings using a KhL-003 chemiluminometer was determined. It was shown that the minimal H2O2 concentration that can be detected in a 0.5-ml sample with this instrument is 0.125 microM. Analysis of biological activity of a mixture of chitooligosaccharides with molecular masses from 5 to 10 kD and acetylation degree of 65% demonstrated that, at a concentration of 1 microg/ml, they induce rapid overproduction of H2O2 in roots of 3-day-old wheat seedlings.

  11. Microbial production of low molecular weight hyaluronic acid by adding hydrogen peroxide and ascorbate in batch culture of Streptococcus zooepidemicus.

    PubMed

    Liu, Long; Du, Guocheng; Chen, Jian; Zhu, Yang; Wang, Miao; Sun, Jun

    2009-01-01

    Microbial production of low molecular weight hyaluronic acid (HA) by the addition of hydrogen peroxide and ascorbate during the batch culture of Streptococcus zooepidemicus was investigated. Hydrogen peroxide (1.0 mmol/g HA) and ascorbate (0.5 mmol/g HA) were added at 8h and 12h to degrade HA. With the redox depolymerization of HA, the HA molecular weight decreased from 1,300 kDa for the control to 80 kDa, and the average broth viscosity during 8-16 h decreased from 360 mPa s for the control to 290 mPa s. The average oxygen mass transfer coefficient K(L)a increased from 10h(-1) for the control to 35 h(-1) and the average dissolved oxygen level increased from 1% of air saturation in the control to 10%. HA production increased from 5.0 g/L for the control to 6.5 g/L, and contributed to the increased redox potential and energy charge. This novel process not only significantly enhanced production of low molecular weight HA, but also improved purification efficiency due to a decreased broth viscosity. Low molecular weight HA finds applications in biomedical and healthcare fields.

  12. Comparison of two at-home whitening products of similar peroxide concentration and different delivery methods.

    PubMed

    da Costa, J B; McPharlin, R; Hilton, T; Ferracane, J I; Wang, M

    2012-01-01

    This study compared the whitening efficacy, side effects, and patients' preferences/perceptions of two whitening systems of similar peroxide concentration but different formulation and delivery methods. The tooth color change of 24 participants was measured using a shade guide (BSG) and a spectrophotometer (ES). Color difference was calculated: ΔE* = [(ΔL*)(2) + (Δa*)(2) + (Δb*)(2)](1/2). One whitening treatment was randomly applied to the right or left maxillary anterior teeth and the other was applied to the contralateral teeth, at-home with 35% carbamide peroxide in a tray (TW) or with 14% hydrogen peroxide in strips (WS). The tooth color was evaluated at baseline, 15 and 30 days (15 days postwhitening). Participants rated their tooth and soft tissue sensitivity (1-10 scale) and completed a questionnaire on their preferences. Results were analyzed by repeated measurement regression analysis/Tukey and Mann-Whitney (p<0.05). At 15 days, the teeth treated with TW and WS presented ΔE* = 7 and 6, respectively (ΔBSG=3 for both), and at 30 days, they presented ΔE* = 7.5 and 6.5, respectively (ΔBSG=3 for both). There was no significant difference in tooth and soft tissue sensitivity between treatments. No participant reported tooth and gingival sensitivity at the postwhitening appointment. Of the participants, 83% preferred the TW over WS. Both ΔE* and ΔBSG showed no significant difference in tooth color change between TW and SW at either time point. By the end of the study no participants reported tooth and gingival sensitivity. Participants preferred TW over SW.

  13. Efficient oxidative hydrogen peroxide production and accumulation in photoelectrochemical water splitting using a tungsten trioxide/bismuth vanadate photoanode.

    PubMed

    Fuku, Kojiro; Sayama, Kazuhiro

    2016-04-07

    An aqueous solution of hydrogen carbonate (HCO3(-)) facilitated oxidative hydrogen peroxide (H2O2) production from water on a WO3/BiVO4 photoanode with the simultaneous production of hydrogen (H2) on a Pt cathode even at an applied voltage far lower than the theoretical electrolysis voltage (+1.77 V vs. RHE) under simulated solar light. The unprecedentedly efficient simultaneous production and accumulation of H2O2 and H2 was achieved in 2.0 M KHCO3 at low temperature, and the maximum selectivity, accumulated concentration and turnover number (TON) of H2O2 generated reached ca. 54%, more than 2 mM and 108, respectively.

  14. Effect of Thai banana (Musa AA group) in reducing accumulation of oxidation end products in UVB-irradiated mouse skin.

    PubMed

    Leerach, Nontaphat; Yakaew, Swanya; Phimnuan, Preeyawass; Soimee, Wichuda; Nakyai, Wongnapa; Luangbudnark, Witoo; Viyoch, Jarupa

    2017-03-01

    Chronic UVB exposure causes skin disorders and cancer through DNA strand breaks and oxidation of numerous functional groups of proteins and lipids in the skin. In this study, we investigated the effects of Thai banana (Musa AA group, "Khai," and Musa ABB group, "Namwa") on the prevention of UVB-induced skin damage when fed to male ICR mice. Mice were orally fed banana (Khai or Namwa) fruit pulps at dose of 1mg/g body weight/day for 12weeks. The shaved backs of the mice were irradiated with UVB for 12weeks. The intensity dose of UVB-exposure was increased from 54mJ/cm 2 /exposure at week 1 to 126mJ/cm 2 /exposure at week 12. A significant increase in skin thickness, lipid peroxidation, protein oxidation end products, and expression of MMP-1 was observed in UVB-irradiated mouse skin. A reduction in the accumulation of oxidation end products was found in the skin of UVB-irradiated mice receiving Khai. This occurred in conjunction with a reduction in MMP-1 expression, inhibition of epidermal thickening, and induction of γ-GCS expression. The dietary intake of Khai prevented skin damage from chronic UVB exposure by increased γ-GCS expression and reduced oxidation end products included carbonyls, malondialdehyde and 4-hydroxynonenal. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Inhibition of cellular proliferation and enhancement of hydrogen peroxide production in fibrosarcoma cell line by weak radio frequency magnetic fields.

    PubMed

    Castello, Pablo R; Hill, Iain; Sivo, Frank; Portelli, Lucas; Barnes, Frank; Usselman, Robert; Martino, Carlos F

    2014-12-01

    This study presents experimental data for the effects of weak radio frequency (RF) magnetic fields on hydrogen peroxide (H2O2) production and cellular growth rates of fibrosarcoma HT1080 cells in vitro. Cells were exposed either to 45 µT static magnetic fields (SMFs)-oriented vertical to the plane of growth or to SMFs combined with weak 5 and 10 MHz RF magnetic fields of 10 µTRMS intensity perpendicular to the static field. Cell numbers were reduced up to 30% on Day 2 for the cells exposed to the combination of SMF and a 10 MHz RF magnetic field compared with the SMF control cells. In addition, cells exposed to 10 MHz RF magnetic fields for 8 h increased H2O2 production by 55%. The results demonstrate an overall magnetic field-induced biological effect that shows elevated H2O2 levels with accompanying decrease in cellular growth rates. © 2014 Wiley Periodicals, Inc.

  16. SigF Controls Carotenoid Pigment Production and Affects Transformation Efficiency and Hydrogen Peroxide Sensitivity in Mycobacterium smegmatis▿ †

    PubMed Central

    Provvedi, Roberta; Kocíncová, Dana; Donà, Valentina; Euphrasie, Daniel; Daffé, Mamadou; Etienne, Gilles; Manganelli, Riccardo; Reyrat, Jean-Marc

    2008-01-01

    Carotenoids are complex lipids that are known for acting against photodynamic injury and free radicals. We demonstrate here that σF is required for carotenoid pigment production in Mycobacterium smegmatis. We further show that a sigF mutant exhibits a transformation efficiency 104-fold higher than that of the parental strain, suggesting that σF regulates the production of components affecting cell wall permeability. In addition, a sigF mutant showed an increased sensitivity to hydrogen peroxide. An in silico search of the M. smegmatis genome identified a number of SigF consensus sites, including sites upstream of the carotenoid synthesis locus, which explains its SigF regulation. PMID:18805974

  17. Mass-spectrometric characterization of phospholipids and their primary peroxidation products in rat cortical neurons during staurosporine-induced apoptosis

    PubMed Central

    Tyurin, Vladimir A.; Tyurina, Yulia Y.; Feng, Weihong; Mnuskin, Alexandra; Jiang, Jianfei; Tang, Minke; Zhang, Xiaojing; Zhao, Qing; Kochanek, Patrick M.; Clark, Robert S. B.; Bayır, Hulya; Kagan, Valerian E.

    2009-01-01

    The molecular diversity of phospholipids is essential for their structural and signaling functions in cell membranes. In the current work, we present, the results of mass spectrometric characterization of individual molecular species in major classes of phospholipids -phosphatidylcholine (PtdCho), phosphatidylethanolamine (PtdEtn), phosphatidylserine (PtdSer), phosphatidylinositol (PtdIns), sphingomyelin (CerPCho), and cardiolipin (Ptd2Gro) - and their oxidation products during apoptosis induced in neurons by staurosporine (STS). The diversity of molecular species of phospholipids in rat cortical neurons followed the order Ptd2Gro > PtdEtn ≫ PtdCho ≫ PtdSer > PtdIns > CerPCho. The number of polyunsaturated oxidizable species decreased in the order Ptd2Gro ≫ PtdEtn > PtdCho > PtdSer > PtdIns > CerPCho. Thus a relatively minor class of phospholipids, Ptd2Gro, was represented in cortical neurons by the greatest variety of both total and peroxidizable molecular species. Quantitative fluorescence HPLC analysis employed to assess the oxidation of different classes of phospholipids in neuronal cells during intrinsic apoptosis induced by staurosporine (STS) revealed that three anionic phospholipids — Ptd2Gro ≫ PtdSer > PtdIns — underwent robust oxidation. No significant oxidation in the most dominant phospholipid classes – PtdCho and PtdEtn – was detected. MS-studies revealed the presence of hydroxy-, hydroperoxy- as well as hydroxy-/hydroperoxy-species of Ptd2Gro, PtdSer, and PtdIns. Experiments in model systems where total cortex Ptd2Gro and PtdSer fractions were incubated in the presence of cytochrome c (cyt c) and H2O2, confirmed that molecular identities of the products formed were similar to the ones generated during STS-induced neuronal apoptosis. The temporal sequence of biomarkers of STS induced apoptosis and phospholipid peroxidation combined with recently demonstrated redox catalytic properties of cyt c realized through its interactions with Ptd2

  18. Steatosis-induced proteins adducts with lipid peroxidation products and nuclear electrophilic stress in hepatocytes.

    PubMed

    Anavi, Sarit; Ni, Zhixu; Tirosh, Oren; Fedorova, Maria

    2015-01-01

    Accumulating evidence suggests that fatty livers are particularly more susceptible to several pathological conditions, including hepatic inflammation, cirrhosis and liver cancer. However the exact mechanism of such susceptibility is still largely obscure. The current study aimed to elucidate the effect of hepatocytes lipid accumulation on the nuclear electrophilic stress. Accumulation of intracellular lipids was significantly increased in HepG2 cells incubated with fatty acid (FA) complex (1mM, 2:1 oleic and palmitic acids). In FA-treated cells, lipid droplets were localized around the nucleus and seemed to induce mechanical force, leading to the disruption of the nucleus morphology. Level of reactive oxygen species (ROS) was significantly increased in FA-loaded cells and was further augmented by treatment with moderate stressor (CoCl2). Increased ROS resulted in formation of reactive carbonyls (aldehydes and ketones, derived from lipid peroxidation) with a strong perinuclear accumulation. Mass-spectroscopy analysis indicated that lipid accumulation per-se can results in modification of nuclear protein by reactive lipid peroxidation products (oxoLPP). 235 Modified proteins involved in transcription regulation, splicing, protein synthesis and degradation, DNA repair and lipid metabolism were identified uniquely in FA-treated cells. These findings suggest that steatosis can affect nuclear redox state, and induce modifications of nuclear proteins by reactive oxoLPP accumulated in the perinuclear space upon FA-treatment. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  19. Characterization of peroxides formed by riboflavin and light exposure of milk. Detection of urate hydroperoxide as a novel oxidation product.

    PubMed

    Clausen, Morten R; Huvaere, Kevin; Skibsted, Leif H; Stagsted, Jan

    2010-01-13

    Characterization of peroxides by size exclusion chromatography (SEC) of milk following exposure to riboflavin and light showed that hydrogen peroxide was the most abundant peroxide formed since it could be removed by catalase. Formation of peroxides after separation by SEC showed that hydrogen peroxide formation was primarily increased in the presence of caseins and ascorbate, although whey proteins also were found to contribute. Caseins and beta-lactoglobulin also formed catalase-resistant peroxides, presumably protein hydroperoxides. A catalase-resistant and unstable peroxide was observed in fractions containing urate. Experiments performed with pure urate suggested that urate radicals reacted further with superoxide leading to a urate hydroperoxide. Electron paramagnetic resonance spectroscopy using spin-traps showed that the presence of oxygen was required for urate radical formation, which could be assigned as nitrogen-centered radicals. These results suggest a new route during light-induced oxidation sensitized by flavins, in effect making urate pro-oxidative.

  20. Hydrogen peroxide (H₂O₂) supply significantly improves xanthan gum production mediated by Xanthomonas campestris in vitro.

    PubMed

    Cheng, Rong; Lin, Lin; Zhang, Yongkui

    2012-05-01

    To improve xanthan gum productivity, a strategy of adding hydrogen peroxide (H₂O₂) was studied. The method could intensify oxygen supply through degradation of H₂O₂ to oxygen (O₂). In shake flask testing, the xanthan gum yield reached 2.8% (improved by 39.4%) when adding 12.5 mM H₂O₂ after 24 h of fermentation. In fermentor testing, it was obvious that the oxygen conditions varied with the H₂O₂ addition time. Eventually, gum yield of 4.2% (w/w) was achieved (increased by 27.3%). Compared with the method of intense mixing and increasing the air flow rate, adding H₂O₂ to improve the dissolved oxygen concentration was more effective and much better. Moreover, addition of H₂O₂ improved the quality of xanthan gum; the pyruvate content of xanthan was 4.4% (w/w), higher than that of the control (3.2%).

  1. Sporicidal performance induced by photocatalytic production of organic peroxide under visible light irradiation

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Yuichi; Shimodo, Takahito; Chikamori, Noriyasu; Usuki, Sho; Kanai, Yoshihiro; Endo, Takeshi; Katsumata, Ken-Ichi; Terashima, Chiaki; Ikekita, Masahiko; Fujishima, Akira; Suzuki, Tomonori; Sakai, Hideki; Nakata, Kazuya

    2016-09-01

    Bacteria that cause serious food poisoning are known to sporulate under conditions of nutrient and water shortage. The resulting spores have much greater resistance to common sterilization methods, such as heating at 100 °C and exposure to various chemical agents. Because such bacteria cannot be inactivated with typical alcohol disinfectants, peroxyacetic acid (PAA) often is used, but PAA is a harmful agent that can seriously damage human health. Furthermore, concentrated hydrogen peroxide, which is also dangerous, must be used to prepare PAA. Thus, the development of a facile and safe sporicidal disinfectant is strongly required. In this study, we have developed an innovative sporicidal disinfection method that employs the combination of an aqueous ethanol solution, visible light irradiation, and a photocatalyst. We successfully produced a sporicidal disinfectant one hundred times as effective as commercially available PAA, while also resolving the hazards and odor problems associated with PAA. The method presented here can potentially be used as a replacement for the general disinfectants employed in the food and health industries.

  2. Sporicidal performance induced by photocatalytic production of organic peroxide under visible light irradiation

    PubMed Central

    Yamaguchi, Yuichi; Shimodo, Takahito; Chikamori, Noriyasu; Usuki, Sho; Kanai, Yoshihiro; Endo, Takeshi; Katsumata, Ken-ichi; Terashima, Chiaki; Ikekita, Masahiko; Fujishima, Akira; Suzuki, Tomonori; Sakai, Hideki; Nakata, Kazuya

    2016-01-01

    Bacteria that cause serious food poisoning are known to sporulate under conditions of nutrient and water shortage. The resulting spores have much greater resistance to common sterilization methods, such as heating at 100 °C and exposure to various chemical agents. Because such bacteria cannot be inactivated with typical alcohol disinfectants, peroxyacetic acid (PAA) often is used, but PAA is a harmful agent that can seriously damage human health. Furthermore, concentrated hydrogen peroxide, which is also dangerous, must be used to prepare PAA. Thus, the development of a facile and safe sporicidal disinfectant is strongly required. In this study, we have developed an innovative sporicidal disinfection method that employs the combination of an aqueous ethanol solution, visible light irradiation, and a photocatalyst. We successfully produced a sporicidal disinfectant one hundred times as effective as commercially available PAA, while also resolving the hazards and odor problems associated with PAA. The method presented here can potentially be used as a replacement for the general disinfectants employed in the food and health industries. PMID:27666195

  3. Hydrogen Peroxide Is Involved in Salicylic Acid-Elicited Rosmarinic Acid Production in Salvia miltiorrhiza Cell Cultures

    PubMed Central

    Hao, Wenfang; Zhang, Jingyi; Hu, Gege; Yao, Yaqin; Dong, Juane

    2014-01-01

    Salicylic acid (SA) is an elicitor to induce the biosynthesis of secondary metabolites in plant cells. Hydrogen peroxide (H2O2) plays an important role as a key signaling molecule in response to various stimuli and is involved in the accumulation of secondary metabolites. However, the relationship between them is unclear and their synergetic functions on accumulation of secondary metabolites are unknown. In this paper, the roles of SA and H2O2 in rosmarinic acid (RA) production in Salvia miltiorrhiza cell cultures were investigated. The results showed that SA significantly enhanced H2O2 production, phenylalanine ammonia-lyase (PAL) activity, and RA accumulation. Exogenous H2O2 could also promote PAL activity and enhance RA production. If H2O2 production was inhibited by NADPH oxidase inhibitor (IMD) or scavenged by quencher (DMTU), RA accumulation would be blocked. These results indicated that H2O2 is secondary messenger for signal transduction, which can be induced by SA, significantly and promotes RA accumulation. PMID:24995364

  4. 5-Methylcytosine attack by hydroxyl free radicals and during carbon tetrachloride promoted liver microsomal lipid peroxidation: structure of reaction products.

    PubMed

    Castro, G D; Díaz Gómez, M I; Castro, J A

    1996-01-05

    We recently reported that trichloromethyl and trichloromethylperoxyl radicals attack 5-methylcytosine (5MC) to give several products derived from hydroxylation, deamination or halogenation reactions. Hydroxyl radicals and lipid peroxidation (LP) are more frequently involved in deleterious pathological or toxicological processes than those CCl4 derived radicals and thus we considered it of interest to test whether they also alter 5MC. We observed that OH radicals generated by 0.1 mM Fe2+/2.5 mM H202 at 25 degrees C for 1 h led to the production of 5-hydroxymethylcytosine (5MHC). When OH generation was performed with UV light (254 nm, 3400 muWatt/cm2) and 2mM H202 during 4 min at 25 degrees C the following products were observed: 5-hydroxy-5-methylhydantoin, 5-hydroxyhydantoin, 5MHC, thymine glycol (two isomers) and 5-hydroxymethyl-6-hydroxycytosine. When 5MC was exposed to liver microsomal suspensions in the presence of NADPH generating system and carbon tetrachloride during 1 h at 37 degrees C and under air, the formation of only 5HMC was observed. Detection and identification of all reaction products was done by GC/MS analysis of trimethylsilyl derivatives of the bases. If similar reactions occurred in DNA, these results might be of relevance to gene control, differentiation and carcinogenesis.

  5. Production of stabilized Criegee intermediates and peroxides in the gas phase ozonolysis of alkenes: 2. Asymmetric and biogenic alkenes

    NASA Astrophysics Data System (ADS)

    Hasson, Alam S.; Ho, Andy W.; Kuwata, Keith T.; Paulson, Suzanne E.

    2001-12-01

    Organic hydroperoxide, hydrogen peroxide, and >C1 carbonyl yields have been measured from the reaction of a set of structurally diverse and atmospherically significant terminal and exocyclic alkenes with ozone. Product yields were investigated for 1-butene, 1-pentene, 1-octene, methylene cyclohexane, β-pinene, camphene and isoprene for humidities from 0 to 80% using gas chromatography with flame ionization detection and high-performance liquid chromatography with fluorescence detection. The yields of these products were used to estimate the following stabilized Criegee intermediate yields: 1-butene (0.27), 1-pentene (0.29), 1-octene (0.36), methylene cyclohexane (0.18), β-pinene (0.28), camphene (0.31), and isoprene (0.27). The reaction of stabilized Criegee intermediates with water produces primarily hydroxymethyl hydroperoxide from CH2OO, and H2O2 and a carbonyl compound for larger Criegee intermediates; acid formation is expected to be low. The exception is camphene, for which the large Criegee intermediate generates the corresponding hydroxyalkyl hydroperoxide in its reaction with water. These results were used to develop a structure activity relationship to estimate stabilized Criegee intermediate yields and to demonstrate that this model is consistent with literature values for OH yields from these ozone-alkene reactions. The mechanisms of the formation of these products are discussed and a hypothesis for the decrease in OH formation with increasing chain length for terminal alkenes is provided. Finally, a parameterization of the reactions for incorporation into atmospheric models is developed.

  6. A six-month study of two self-applied tooth whitening products containing carbamide peroxide.

    PubMed

    Brunton, Paul A; Ellwood, Roger; Davies, Robin

    2004-01-01

    Bleaching offers a non-interventive way of improving the appearance of sound, yet discolored anterior teeth. Until recently, the whitening agent was applied using a tray, but now other methods of delivering whitening agents, such as those using brush applicators, are available. This study investigated the tooth whitening efficacy of two novel, self-applied tooth whitening systems containing either 18% (Group 1) or 16.4% (Group 2) carbamide peroxide. Ninety-five subjects, ranging in age from 18 to 70 with anterior teeth A3 or darker, were recruited and randomly allocated to a group. The subjects were instructed to apply the formulation to all maxillary anterior teeth after brushing in the morning and evening. At baseline, two weeks and six months the upper six anterior teeth of the subjects were measured using the Vita shade guide tab system. In addition, the gingival health of the labial surfaces of the upper six anterior teeth was assessed using the Loee and Silness Gingival index (Loee & Silness, 1963) at baseline and at two weeks. The mean (SD) reduction in shade guide scores was 4.1 (2.4) shade guide tabs for subjects in Group 1, compared to 3.7 (2.6) shades for those in Group 2. This difference was not statistically significant (p=0.5). During the course of study, the gingivitis scores reduced from a mean (SD) of 0.91 (0.62) at baseline to 0.44 (0.55) at final examination (48% reduction). At the six-month recall, the mean (SD) reduction in shade guide scores was 2.3 (2.7) shade guide tabs for subjects in Group 1, compared to 2.5 (2.5) shades for those in Group 2. The different concentrations tested were found to be equally effective in improving the whiteness of upper anterior teeth by approximately four shades over a two-week period and the majority of the whitening benefit (c.60%) was sustained at six-month recall.

  7. Hydrogen peroxide production from fibrous pectic cellulose analogs and effect on dermal fibroblasts

    USDA-ARS?s Scientific Manuscript database

    Naturally derived products with folklore remedies have in recent years been reconsidered for their benefit to wound healing i.e., honey’s application to chronic wound dressing products. Similarly, we have undertaken an evaluation of Fibrous pectin-cellulose (FPC) (cellulose blended with primary cel...

  8. QUENCHING OF CHLORINATION DISINFECTION BY-PRODUCT FORMATION IN DRINKING WATER BY HYDROGEN PEROXIDE. (R825362)

    EPA Science Inventory

    Reactions between chlorine disinfectants, dissolved organic matter, and other chemicals in water form a series of disinfection by-products (DBPs), including trihalomethanes (THMs) and haloacetic acids (HAAs), that are toxic and subject to increasingly stringent regulations. Th...

  9. Hydrogen peroxide poisoning.

    PubMed

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

    2004-01-01

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

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

    PubMed

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

    2015-03-01

    The production of reactive oxygen species (ROS) is an unavoidable part of photosynthesis. Stress that accompanies high light levels and low CO2 availability putatively includes enhanced ROS production in the so-called Mehler reaction. Such conditions are thought to encourage O2 to become an electron acceptor at photosystem I, producing the ROS superoxide anion radical (O2·-) and hydrogen peroxide (H2 O2 ). In contrast, here it is shown in Chlamydomonas reinhardtii that CO2 depletion under high light levels lowered cellular H2 O2 production, and that elevated CO2 levels increased H2 O2 production. Using various photosynthetic and mitochondrial mutants of C. reinhardtii, the chloroplast was identified as the main source of elevated H2 O2 production under high CO2 availability. High light levels under low CO2 availability induced photoprotective mechanisms called non-photochemical quenching, or NPQ, including state transitions (qT) and high energy state quenching (qE). The qE-deficient mutant npq4 produced more H2 O2 than wild-type cells under high light levels, although less so under high CO2 availability, whereas it demonstrated equal or greater enzymatic H2 O2 -degrading capacity. The qT-deficient mutant stt7-9 produced the same H2 O2 as wild-type cells under high CO2 availability. Physiological levels of H2 O2 were able to hinder qT and the induction of state 2, providing an explanation for why under high light levels and high CO2 availability wild-type cells behaved like stt7-9 cells stuck in state 1. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

  11. Chlorinated phenol treatment and in situ hydrogen peroxide production in a sulfate-reducing bacteria enriched bioelectrochemical system.

    PubMed

    Miran, Waheed; Nawaz, Mohsin; Jang, Jiseon; Lee, Dae Sung

    2017-06-15

    Wastewaters are increasingly being considered as renewable resources for the sustainable production of electricity, fuels, and chemicals. In recent years, bioelectrochemical treatment has come to light as a prospective technology for the production of energy from wastewaters. In this study, a bioelectrochemical system (BES) enriched with sulfate-reducing bacteria (SRB) in the anodic chamber was proposed and evaluated for the biodegradation of recalcitrant chlorinated phenol, electricity generation (in the microbial fuel cell (MFC)), and production of hydrogen peroxide (H 2 O 2 ) (in the microbial electrolysis cell (MEC)), which is a very strong oxidizing agent and often used for the degradation of complex organics. Maximum power generation of 253.5 mW/m 2 , corresponding to a current density of 712.0 mA/m 2 , was achieved in the presence of a chlorinated phenol pollutant (4-chlorophenol (4-CP) at 100 mg/L (0.78 mM)) and lactate (COD of 500 mg/L). In the anodic chamber, biodegradation of 4-CP was not limited to dechlorination, and further degradation of one of its metabolic products (phenol) was observed. In MEC operation mode, external voltage (0.2, 0.4, or 0.6 V) was added via a power supply, with 0.4 V producing the highest concentration of H 2 O 2 (13.3 g/L-m 2 or 974 μM) in the cathodic chamber after 6 h of operation. Consequently, SRB-based bioelectrochemical technology can be applied for chlorinated pollutant biodegradation in the anodic chamber and either net current or H 2 O 2 production in the cathodic chamber by applying an optimum external voltage. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Plasticity of the Pyruvate Node Modulates Hydrogen Peroxide Production and Acid Tolerance in Multiple Oral Streptococci.

    PubMed

    Cheng, Xingqun; Redanz, Sylvio; Cullin, Nyssa; Zhou, Xuedong; Xu, Xin; Joshi, Vrushali; Koley, Dipankar; Merritt, Justin; Kreth, Jens

    2018-01-15

    Commensal Streptococcus sanguinis and Streptococcus gordonii are pioneer oral biofilm colonizers. Characteristic for both is the SpxB-dependent production of H 2 O 2 , which is crucial for inhibiting competing biofilm members, especially the cariogenic species Streptococcus mutans H 2 O 2 production is strongly affected by environmental conditions, but few mechanisms are known. Dental plaque pH is one of the key parameters dictating dental plaque ecology and ultimately oral health status. Therefore, the objective of the current study was to characterize the effects of environmental pH on H 2 O 2 production by S. sanguinis and S. gordonii S. sanguinis H 2 O 2 production was not found to be affected by moderate changes in environmental pH, whereas S. gordonii H 2 O 2 production declined markedly in response to lower pH. Further investigation into the pyruvate node, the central metabolic switch modulating H 2 O 2 or lactic acid production, revealed increased lactic acid levels for S. gordonii at pH 6. The bias for lactic acid production at pH 6 resulted in concomitant improvement in the survival of S. gordonii at low pH and seems to constitute part of the acid tolerance response of S. gordonii Differential responses to pH similarly affect other oral streptococcal species, suggesting that the observed results are part of a larger phenomenon linking environmental pH, central metabolism, and the capacity to produce antagonistic amounts of H 2 O 2 IMPORTANCE Oral biofilms are subject to frequent and dramatic changes in pH. S. sanguinis and S. gordonii can compete with caries- and periodontitis-associated pathogens by generating H 2 O 2 Therefore, it is crucial to understand how S. sanguinis and S. gordonii adapt to low pH and maintain their competitiveness under acid stress. The present study provides evidence that certain oral bacteria respond to environmental pH changes by tuning their metabolic output in favor of lactic acid production, to increase their acid survival

  13. Influence of feeding thermally peroxidized soybean oil on growth performance, digestibility, and gut integrity in growing pigs.

    PubMed

    Lindblom, S C; Gabler, N K; Kerr, B J

    2018-01-29

    Consumption of highly peroxidized oils has been shown to affect pig performance and oxidative status through the development of compounds which differ according to how oils are thermally processed. The objective of this study was to evaluate the effect of feeding varying degrees of peroxidized soybean oil (SO) on parameters of growth performance; lipid, N, and GE digestibility, gut integrity in growing pigs, and plasma Trp. Fifty-six barrows (25.3 ± 3.3 kg initial BW) were randomly assigned to 1 of 4 diets containing either 10% fresh SO (22.5oC) or thermally processed SO (45oC for 288 h, 90oC for 72 h, or 180oC for 6 h), each with an air infusion of 15 L/min. Peroxide values for the 22.5, 45, 90 and 180oC processed SO were 2.0, 96, 145, and 4.0 mEq/kg, respectively; 2,4-decadienal values for 22.5, 45, 90 and 180oC processed SO were 2.11,5.05, 547.62, and 323.57 mg/kg, respectively; and 4-hydroxynonenal concentrations of 0.05, 1.05, 39.46, and 25.71 mg/kg with increasing SO processing temperature. Pigs were individually housed and fed ad libitum for a 49 d period to determine the effects of SO peroxidation status on growth performance, including a metabolism period for assessing GE and N digestibility, and N retention. In vivo urinary lactulose to mannitol ratio was also assessed to evaluate potential changes in small intestinal integrity. Although there were no differences observed in ADFI (P = 0.19), ADG was decreased in pigs fed 90oC SO diet (P = 0.01), while G:F was increased (P = 0.02) in pigs fed 45oC SO diet compared to the other SO diets. Pigs fed the 90oC processed SO had the lowest (P = 0.01) DE as a % of GE, whereas ME as a % of DE was lowest (P = 0.05) in pigs fed the 180 oC SO and 90oC SO followed by 45oC SO and fresh SO. Ether extract digestibility was lowest (P = 0.01) in pigs fed 90oC SO followed by pigs fed 180oC SO, 45oC SO, and fresh SO. The percent of N retained was greatest (P = 0.01) in pigs fed fresh SO followed by pigs fed 45oC SO, 180oC SO

  14. Sites of superoxide and hydrogen peroxide production during fatty acid oxidation in rat skeletal muscle mitochondria

    PubMed Central

    Perevoshchikova, Irina V.; Quinlan, Casey L.; Orr, Adam L.; Gerencser, Akos A.; Brand, Martin D.

    2013-01-01

    H2O2 production by skeletal muscle mitochondria oxidizing palmitoylcarnitine was examined under two conditions: the absence of respiratory chain inhibitors and the presence of myxothiazol to inhibit complex III. Without inhibitors, respiration and H2O2 production were low unless carnitine or malate was added to limit acetyl-CoA accumulation. With palmitoylcarnitine alone, H2O2 production was dominated by complex II (44% from site IIF in the forward reaction); the remainder was mostly from complex I (34%, superoxide from site IF). With added carnitine, H2O2 production was about equally shared between complexes I, II, and III. With added malate, it was 75% from complex III (superoxide from site IIIQo) and 25% from site IF. Thus complex II (site IIF in the forward reaction) is a major source of H2O2 production during oxidation of palmitoylcarnitine ± carnitine. Under the second condition (myxothiazol present to keep ubiquinone reduced), the rates of H2O2 production were highest in the presence of palmitoylcarnitine ± carnitine and were dominated by complex II (site IIF in the reverse reaction). About half the rest was from site IF, but a significant portion, ~40 pmol H2O2 · min−1 · mg protein−1, was not from complex I, II, or III and was attributed to the proteins of β-oxidation (electron-transferring flavoprotein (ETF) and ETF-ubiquinone oxidoreductase). The maximum rate from the ETF system was ~200 pmol H2O2 · min−1 ~ mg protein−1 under conditions of compromised antioxidant defense and reduced ubiqui-none pool. Thus complex II and the ETF system both contribute to H2O2 production during fatty acid oxidation under appropriate conditions. PMID:23583329

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

    PubMed

    Audenaert, Kris; Callewaert, Elien; Höfte, Monica; De Saeger, Sarah; Haesaert, Geert

    2010-04-15

    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. 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. 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.

  16. A PDI-catalyzed thiol-disulfide switch regulates the production of hydrogen peroxide by human Ero1.

    PubMed

    Ramming, Thomas; Okumura, Masaki; Kanemura, Shingo; Baday, Sefer; Birk, Julia; Moes, Suzette; Spiess, Martin; Jenö, Paul; Bernèche, Simon; Inaba, Kenji; Appenzeller-Herzog, Christian

    2015-06-01

    Oxidative folding in the endoplasmic reticulum (ER) involves ER oxidoreductin 1 (Ero1)-mediated disulfide formation in protein disulfide isomerase (PDI). In this process, Ero1 consumes oxygen (O2) and releases hydrogen peroxide (H2O2), but none of the published Ero1 crystal structures reveal any potential pathway for entry and exit of these reactants. We report that additional mutation of the Cys(208)-Cys(241) disulfide in hyperactive Ero1α (Ero1α-C104A/C131A) potentiates H2O2 production, ER oxidation, and cell toxicity. This disulfide clamps two helices that seal the flavin cofactor where O2 is reduced to H2O2. Through its carboxyterminal active site, PDI unlocks this seal by forming a Cys(208)/Cys(241)-dependent mixed-disulfide complex with Ero1α. The H2O2-detoxifying glutathione peroxidase 8 also binds to the Cys(208)/Cys(241) loop region. Supported by O2 diffusion simulations, these data describe the first enzymatically controlled O2 access into a flavoprotein active site, provide molecular-level understanding of Ero1α regulation and H2O2 production/detoxification, and establish the deleterious consequences of constitutive Ero1 activity. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Hydrogen peroxide release kinetics into saliva from different whitening products: a double-blind, randomized clinical trial.

    PubMed

    Marques, Duarte Nuno da Silva; da Mata, António Duarte Sola Pereira; Silveira, João Miguel Lourenço; Marques, Joana Rita Oliveira Faria; Amaral, João Pedro de Almeida Rato; Guilherme, Nuno Filipe Rito Parada Marques

    2012-02-01

    The objective of this study is to compare salivary hydrogen peroxide (HP) release kinetics and potential toxicity of systemic exposure of four different whitening products. A double-blind, randomized controlled trial was conducted in a Portuguese dental faculty clinic. Two hundred forty volunteers were randomized to eight intervention groups. Participants were randomly assigned to receive active or placebo applications of one of four different products: Opalescence 10% PF™ (OPL), Vivastyle® 10%™ (VS10%), Vivadent Paint On Plus™ (PO+), and Trés White Supreme™ (TWS). Saliva collection was obtained by established methods at different times. The HP salivary content was determined by a photometric method. Salivary HP variations, total amount of salivary HP, and counts of subjects above the safe daily HP dose were the main outcome measures. All whitening systems significantly released HP to the saliva when compared to placebo, and all showed different release kinetics. The adaptable tray system (TWS) presented a risk increase of 37% [20-54%, 95% confidence interval] when compared to the other systems. The use of an adaptable tray whitening system with higher concentration of HP increases the toxicity potential.

  18. Endogenous hydrogen peroxide increases biofilm formation by inducing exopolysaccharide production in Acinetobacter oleivorans DR1.

    PubMed

    Jang, In-Ae; Kim, Jisun; Park, Woojun

    2016-02-17

    In this study, we investigated differentially expressed proteins in Acinetobacter oleivorans cells during planktonic and biofilm growth by using 2-dimensional gel electrophoresis combined with matrix-assisted laser desorption time-of-flight mass spectrometry. We focused on the role of oxidative stress resistance during biofilm formation using mutants defective in alkyl hydroperoxide reductase (AhpC) because its production in aged biofilms was enhanced compared to that in planktonic cells. Results obtained using an ahpC promoter-gfp reporter vector showed that aged biofilms expressed higher ahpC levels than planktonic cells at 48 h. However, at 24 h, ahpC expression was higher in planktonic cells than in biofilms. Deletion of ahpC led to a severe growth defect in rich media that was not observed in minimal media and promoted early biofilm formation through increased production of exopolysaccharide (EPS) and EPS gene expression. Increased endogenous H2O2 production in the ahpC mutant in rich media enhanced biofilm formation, and this enhancement was not observed in the presence of antioxidants. Exogenous addition of H2O2 promoted biofilm formation in wild type cells, which suggested that biofilm development is linked to defense against H2O2. Collectively, our data showed that EPS production caused by H2O2 stress enhances biofilm formation in A. oleivorans.

  19. Quantification of the production of hydrogen peroxide H2O2 during accelerated wine oxidation.

    PubMed

    Héritier, Julien; Bach, Benoît; Schönenberger, Patrik; Gaillard, Vanessa; Ducruet, Julien; Segura, Jean-Manuel

    2016-11-15

    Understanding how wines react towards oxidation is of primary importance. Here, a novel approach was developed based on the quantitative determination of the key intermediate H2O2 produced during accelerated oxidation by ambient oxygen. The assay makes use of the conversion of the non-fluorescent Amplex Red substrate into a fluorescent product in presence of H2O2. The total production of H2O2 during 30min was quantified with low within-day and between-day variabilities. Polymerized pigments, but not total polyphenols, played a major role in the determination of H2O2 levels, which were lower in white wines than red wines. H2O2 amounts also increased with temperature and the addition of metal ions, but did not depend on the concentration of many other wine constituents such as SO2. H2O2 levels did not correlate with anti-oxidant properties. We believe that this novel methodology might be generically used to decipher the oxidation mechanisms in wines and food products. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Semi-rational engineering of cellobiose dehydrogenase for improved hydrogen peroxide production.

    PubMed

    Sygmund, Christoph; Santner, Paul; Krondorfer, Iris; Peterbauer, Clemens K; Alcalde, Miguel; Nyanhongo, Gibson S; Guebitz, Georg M; Ludwig, Roland

    2013-04-23

    The ability of fungal cellobiose dehydrogenase (CDH) to generate H2O2 in-situ is highly interesting for biotechnological applications like cotton bleaching, laundry detergents or antimicrobial functionalization of medical devices. CDH's ability to directly use polysaccharide derived mono- and oligosaccharides as substrates is a considerable advantage compared to other oxidases such as glucose oxidase which are limited to monosaccharides. However CDH's low activity with oxygen as electron acceptor hampers its industrial use for H2O2 production. A CDH variant with increased oxygen reactivity is therefore of high importance for biotechnological application. Uniform expression levels and an easy to use screening assay is a necessity to facilitate screening for CDH variants with increased oxygen turnover. A uniform production and secretion of active Myriococcum thermophilum CDH was obtained by using Saccharomyces cerevisiae as expression host. It was found that the native secretory leader sequence of the cdh gene gives a 3 times higher expression than the prepro leader of the yeast α-mating factor. The homogeneity of the expression in 96-well deep-well plates was good (variation coefficient <15%). A high-throughput screening assay was developed to explore saturation mutagenesis libraries of cdh for improved H2O2 production. A 4.5-fold increase for variant N700S over the parent enzyme was found. For production, N700S was expressed in P. pastoris and purified to homogeneity. Characterization revealed that not only the kcat for oxygen turnover was increased in N700S (4.5-fold), but also substrate turnover. A 3-fold increase of the kcat for cellobiose with alternative electron acceptors indicates that mutation N700S influences the oxidative- and reductive FAD half-reaction. Site-directed mutagenesis and directed evolution of CDH is simplified by the use of S. cerevisiae instead of the high-yield-host P. pastoris due to easier handling and higher transformation efficiencies

  1. Hydrogen Peroxide Production from Glycerol Metabolism Is Dispensable for Virulence of Mycoplasma gallisepticum in the Tracheas of Chickens

    PubMed Central

    Szczepanek, S. M.; Boccaccio, M.; Pflaum, K.; Liao, X.

    2014-01-01

    Hydrogen peroxide (H2O2) is a by-product of glycerol metabolism in mycoplasmas and has been shown to cause cytotoxicity for cocultured eukaryotic cells. There appears to be selective pressure for mycoplasmas to retain the genes needed for glycerol metabolism. This has generated interest and speculation as to their function during infection. However, the actual effects of glycerol metabolism and H2O2 production on virulence in vivo have never been assessed in any Mycoplasma species. To this end, we determined that the wild-type (WT) Rlow strain of the avian pathogen Mycoplasma gallisepticum is capable of producing H2O2 when grown in glycerol and is cytotoxic to eukaryotic cells in culture. Transposon mutants with mutations in the genes present in the glycerol transport and utilization pathway, namely, glpO, glpK, and glpF, were identified. All mutants assessed were incapable of producing H2O2 and were not cytotoxic when grown in glycerol. We also determined that vaccine strains ts-11 and 6/85 produce little to no H2O2 when grown in glycerol, while the naturally attenuated F strain does produce H2O2. Chickens were infected with one of two glpO mutants, a glpK mutant, Rlow, or growth medium, and tracheal mucosal thickness and lesion scores were assessed. Interestingly, all glp mutants were reproducibly virulent in the respiratory tracts of the chickens. Thus, there appears to be no link between glycerol metabolism/H2O2 production/cytotoxicity and virulence for this Mycoplasma species in its natural host. However, it is possible that glycerol metabolism is required by M. gallisepticum in a niche that we have yet to study. PMID:25156740

  2. Products of lipid peroxidation, but not membrane susceptibility to oxidative damage, are conserved in skeletal muscle following temperature acclimation.

    PubMed

    Grim, Jeffrey M; Semones, Molly C; Kuhn, Donald E; Kriska, Tamas; Keszler, Agnes; Crockett, Elizabeth L

    2015-03-01

    Changes in oxidative capacities and phospholipid remodeling accompany temperature acclimation in ectothermic animals. Both responses may alter redox status and membrane susceptibility to lipid peroxidation (LPO). We tested the hypothesis that phospholipid remodeling is sufficient to offset temperature-driven rates of LPO and, thus, membrane susceptibility to LPO is conserved. We also predicted that the content of LPO products is maintained over a range of physiological temperatures. To assess LPO susceptibility, rates of LPO were quantified with the fluorescent probe C11-BODIPY in mitochondria and sarcoplasmic reticulum from oxidative and glycolytic muscle of striped bass (Morone saxatilis) acclimated to 7°C and 25°C. We also measured phospholipid compositions, contents of LPO products [i.e., individual classes of phospholipid hydroperoxides (PLOOH)], and two membrane antioxidants. Despite phospholipid headgroup and acyl chain remodeling, these alterations do not counter the effect of temperature on LPO rates (i.e., LPO rates are generally not different among acclimation groups when normalized to phospholipid content and compared at a common temperature). Although absolute levels of PLOOH are higher in muscles from cold- than warm-acclimated fish, this difference is lost when PLOOH levels are normalized to total phospholipid. Contents of vitamin E and two homologs of ubiquinone are more than four times higher in mitochondria prepared from oxidative muscle of warm- than cold-acclimated fish. Collectively, our data demonstrate that although phospholipid remodeling does not provide a means for offsetting thermal effects on rates of LPO, differences in phospholipid quantity ensure a constant proportion of LPO products with temperature variation. Copyright © 2015 the American Physiological Society.

  3. Derivatization and detection of small aliphatic and lipid-bound carbonylated lipid peroxidation products by ESI-MS.

    PubMed

    Milic, Ivana; Fedorova, Maria

    2015-01-01

    Double bonds in polyunsaturated fatty acids (PUFA) and lipids are one of the major targets of reactive oxygen species (ROS). The resulting lipid peroxidation products (LPP) represent a group of chemically diverse compounds formed by several consecutive oxidative reactions. Oxidative cleavage leads to the formation of small aliphatic and lipid-bound aldehydes and ketones (oxoLPPs). These strong electrophiles can readily react with nucleophilic substrates, for example, side chains in proteins which can alter structure, function, and cellular distribution of the modified proteins. Despite growing interest in the field of oxidative lipidomics, only a few dominantly formed oxoLPP were identified. Due to the chemical and physical properties, aliphatic oxoLPPs are usually analyzed using gas chromatography-mass spectrometry (GC- MS), while nonvolatile lipid-bound oxoLPPs require liquid chromatography-mass spectrometry (LC-MS). To overcome the need for the two analyses, we have developed a new derivatization strategy to capture all oxoLPP independent to their properties with electrospray ionization (ESI) MS allowing simultaneous detection of aliphatic and lipid-bound oxoLPPs. Thus, the 7-(diethylamino)coumarin-3-carbohydrazide (CHH) derivatization reagent allowed us to identify 122 carbonyl compounds in a mixture of four PUFA and phosphatidylcholines (PC) oxidized in vitro.

  4. Enhancement of lipid production in Scenedesmus sp. by UV mutagenesis and hydrogen peroxide treatment.

    PubMed

    Sivaramakrishnan, Ramachandran; Incharoensakdi, Aran

    2017-07-01

    The high potential UV mutagenized Scenedesmus sp. was obtained in which the cells had a higher biomass and lipid content than the wild type with an increase from 1.9 to 2.4g/L and from 40 to 55% of dry cell weight respectively after 12days. Oxidative stress imposed by H2O2 treatment decreased the biomass of both the wild type and the mutant. The H2O2 treated mutant when grown in BG11 medium showed an increase in biomass which was in contrast to a decreased biomass observed in the H2O2 treated wild type. A 3-fold increase in lipid yield of 1.63g/L was obtained in the oxidative stress-induced mutant compared to the wild type. Overall results indicate that prior treatment of UV-mutagenized Scenedesmus with oxidative stress can increase the total lipid production which, due to its derived methyl ester having acceptable biodiesel properties, can be potentially utilized for biodiesel production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. 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

  6. Overexpression of sweetpotato swpa4 peroxidase results in increased hydrogen peroxide production and enhances stress tolerance in tobacco.

    PubMed

    Kim, Yun-Hee; Kim, Cha Young; Song, Wan-Keun; Park, Doo-Sang; Kwon, Suk-Yoon; Lee, Haeng-Soon; Bang, Jae-Wook; Kwak, Sang-Soo

    2008-03-01

    Plant peroxidases (POD) reduce hydrogen peroxide (H(2)O(2)) in the presence of an electron donor. Extracellular POD can also induce H(2)O(2) production and may perform a significant function in responses to environmental stresses via the regulation of H(2)O(2) in plants. We previously described the isolation of 10 POD cDNA clones from cell cultures of sweetpotato (Ipomoea batatas). Among them, the expression of the swpa4 gene was profoundly induced by a variety of abiotic stresses and pathogenic infections (Park et al. in Mol Gen Genome 269:542-552 2003; Jang et al. in Plant Physiol Biochem 42:451-455 2004). In the present study, transgenic tobacco (Nicotiana tabacum) plants overexpressing the swpa4 gene under the control of the CaMV 35S promoter were generated in order to assess the function of swpa4 in planta. The transgenic plants exhibited an approximately 50-fold higher POD specific activity than was observed in control plants. Both transient expression analysis with the swpa4-GFP fusion protein and POD activity assays in the apoplastic washing fluid revealed that the swpa4 protein is secreted into the apoplastic space. In addition, a significantly enhanced tolerance to a variety of abiotic and biotic stresses occurred in the transgenic plants. These plants harbored increased lignin and phenolic content, and H(2)O(2 )was also generated under normal conditions. Furthermore, they showed an increased expression level of a variety of apoplastic acidic pathogenesis-related (PR) genes following enhanced H(2)O(2) production. These results suggest that the expression of swpa4 in the apoplastic space may function as a positive defense signal in the H(2)O(2)-regulated stress response signaling pathway.

  7. Effect of Vitamin E and Zinc Supplementation on Energy Metabolites, Lipid Peroxidation, and Milk Production in Peripartum Sahiwal Cows

    PubMed Central

    Chandra, G.; Aggarwal, A.; Singh, A. K.; Kumar, M.; Upadhyay, R. C.

    2013-01-01

    The study was conducted to evaluate the effect of vitamin E and zinc supplementation on energy metabolites, lipid peroxidation, and milk production in peripartum Sahiwal cows. For this, thirty-two pregnant dry Sahiwal cows were selected at sixty days prepartum and divided into four groups viz control, T1, T2, and T3 of eight each. Group T1 were supplemented with zinc at 60 ppm/d/cow, group T2 were supplemented with vitamin E at 1,000 IU/d/cow and group T3 were supplemented with combination of vitamin E at 1,000 IU/d/cow and zinc at 60 ppm/d/cow during d 60 prepartum to d 90 postpartum. Blood samples were collected on d −60, −45, −30, −15, −7, −3, 0, 3, 7, 15, 30, 45, 60, 90, and 120 with respect to day of parturition and analysed for glucose, non esterified fatty acid, and thiobarbituric acid reactive substance. Body condition score was maintained significantly better (p<0.05) in T3 than in the control, T1 and T2 groups. Overall glucose level was higher (p<0.05) in T3 than control, T1, and T2 groups. Levels of nonesterified fatty acid, and thiobarbituric acid reactive substance were lower (p<0.05) in T3 than control, T1, and T2 groups. Milk yield was higher (p<0.05) in T3 than control, T1, and T2 groups. In conclusion, the present study indicated that the supplementation of vitamin E and zinc in peripartum Sahiwal cows enhanced milk production by reducing negative energy balance. PMID:25049743

  8. Mechanistic study on ultrasound assisted pretreatment of sugarcane bagasse using metal salt with hydrogen peroxide for bioethanol production.

    PubMed

    Ramadoss, Govindarajan; Muthukumar, Karuppan

    2016-01-01

    This study presents the ultrasound assisted pretreatment of sugarcane bagasse (SCB) using metal salt with hydrogen peroxide for bioethanol production. Among the different metal salts used, maximum holocellulose recovery and delignification were achieved with ultrasound assisted titanium dioxide (TiO2) pretreatment (UATP) system. At optimum conditions (1% H2O2, 4 g SCB dosage, 60 min sonication time, 2:100 M ratio of metal salt and H2O2, 75°C, 50% ultrasound amplitude and 70% ultrasound duty cycle), 94.98 ± 1.11% holocellulose recovery and 78.72 ± 0.86% delignification were observed. The pretreated SCB was subjected to dilute acid hydrolysis using 0.25% H2SO4 and maximum xylose, glucose and arabinose concentration obtained were 10.94 ± 0.35 g/L, 14.86 ± 0.12 g/L and 2.52 ± 0.27 g/L, respectively. The inhibitors production was found to be very less (0.93 ± 0.11 g/L furfural and 0.76 ± 0.62 g/L acetic acid) and the maximum theoretical yield of glucose and hemicellulose conversion attained were 85.8% and 77%, respectively. The fermentation was carried out using Saccharomyces cerevisiae and at the end of 72 h, 0.468 g bioethanol/g holocellulose was achieved. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis of pretreated SCB was made and its morphology was studied using scanning electron microscopy (SEM). The compounds formed during the pretreatment were identified using gas chromatography-mass spectrometry (GC-MS) analysis. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. 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

  10. Assessing the genotoxic effects of two lipid peroxidation products (4-oxo-2-nonenal and 4-hydroxy-hexenal) in haemocytes and midgut cells of Drosophila melanogaster larvae.

    PubMed

    Demir, Eşref; Marcos, Ricard

    2017-07-01

    Lipid peroxidation products can induce tissue damage and are implicated in diverse pathological conditions, including aging, atherosclerosis, brain disorders, cancer, lung and various liver disorders. Since in vivo studies produce relevant information, we have selected Drosophila melanogaster as a suitable in vivo model to characterise the potential risks associated to two lipid peroxidation products namely 4-oxo-2-nonenal (4-ONE) and 4-hydroxy-hexenal (4-HHE). Toxicity, intracellular reactive oxygen species production, and genotoxicity were the end-points evaluated. Haemocytes and midgut cells were the evaluated targets. Results showed that both compounds penetrate the intestine of the larvae, affecting midgut cells, and reaching haemocytes. Significant genotoxic effects, as determined by the comet assay, were observed in both selected cell targets in a concentration/time dependent manner. This study highlights the importance of D. melanogaster as a model organism in the study of the different biological effects caused by lipid peroxidation products entering via ingestion. This is the first study reporting genotoxicity data in haemocytes and midgut cells of D. melanogaster larvae for the two selected compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. 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, restrictions...

  12. 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, restrictions...

  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, restrictions...

  14. 21 CFR 529.1150 - Hydrogen peroxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Hydrogen peroxide. 529.1150 Section 529.1150 Food... DRUGS, FEEDS, AND RELATED PRODUCTS CERTAIN OTHER DOSAGE FORM NEW ANIMAL DRUGS § 529.1150 Hydrogen peroxide. (a) Specifications. Each milliliter of solution contains 396.1 milligrams (mg) hydrogen peroxide...

  15. 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... DRUGS, FEEDS, AND RELATED PRODUCTS CERTAIN OTHER DOSAGE FORM NEW ANIMAL DRUGS § 529.1150 Hydrogen peroxide. (a) Specifications. Each milliliter of solution contains 396.1 milligrams (mg) hydrogen peroxide...

  16. 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, restrictions...

  17. 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) [Reserved] (c) Limitations...

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

    PubMed Central

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

    2009-01-01

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

  19. Degradation of trichloroethene by siderite-catalyzed hydrogen peroxide and persulfate: Investigation of reaction mechanisms and degradation products.

    PubMed

    Yan, Ni; Liu, Fei; Xue, Qiang; Brusseau, Mark L; Liu, Yali; Wang, Junjie

    2015-08-15

    A binary catalytic system, siderite-catalyzed hydrogen peroxide (H 2 O 2 ) coupled with persulfate (S 2 O 8 2- ), was investigated for the remediation of trichloroethene (TCE) contamination. Batch experiments were conducted to investigate reaction mechanisms, oxidant decomposition rates, and degradation products. By using high performance liquid chromatography (HPLC) coupled with electron paramagnetic resonance (EPR), we identified four radicals (hydroxyl (HO·), sulfate (SO 4 - ·), hydroperoxyl (HO 2 ·), and superoxide (O 2 - ·)) in the siderite-catalyzed H 2 O 2 -S 2 O 8 2- system. In the absence of S 2 O 8 2- (i.e., siderite-catalyzed H 2 O 2 ), a majority of H 2 O 2 was decomposed in the first hour of the experiment, resulting in the waste of HO·. The addition of S 2 O 8 2- moderated the H 2 O 2 decomposition rate, producing a more sustainable release of hydroxyl radicals that improved the treatment efficiency. Furthermore, the heat released by H 2 O 2 decomposition accelerated the activation of S 2 O 8 2- , and the resultant SO 4 - · was the primary oxidative agent during the first two hours of the reaction. Dichloroacetic acid was firstly detected by ion chromatography (IC). The results of this study indicate a new insight to the reaction mechanism for the catalytic binary H 2 O 2 -S 2 O 8 2- oxidant system, and the delineation of radicals and the discovery of the chlorinated byproduct provide useful information for efficient treatment of chlorinated-solvent contamination in groundwater.

  20. Ethanol production from a biomass mixture of furfural residues with green liquor-peroxide saccarified cassava liquid.

    PubMed

    Ji, Li; Zheng, Tianran; Zhao, Pengxiang; Zhang, Weiming; Jiang, Jianxin

    2016-06-01

    As the most abundant renewable resources, lignocellulosic materials are ideal candidates as alternative feedstock for bioethanol production. Cassava residues (CR) are byproducts of the cassava starch industry which can be mixed with lignocellulosic materials for ethanol production. The presence of lignin in lignocellulosic substrates can inhibit saccharification by reducing the cellulase activity. Simultaneous saccharification and fermentation (SSF) of furfural residues (FR) pretreated with green liquor and hydrogen peroxide (GL-H2O2) with CR saccharification liquid was investigated. The final ethanol concentration, yield, initial rate, number of live yeast cells, and the dead yeast ratio were compared to evaluate the effectiveness of combining delignificated lignocellulosic substrates and starchy substrates for ethanol production. Our results indicate that 42.0 % of FR lignin removal was achieved on FR using of 0.06 g H2O2/g-substrate and 9 mL GL/g-substrate at 80 °C. The highest overall ethanol yield was 93.6 % of the theoretical. When the ratio of 0.06 g/g-H2O2-GL-pretreated FR to CR was 5:1, the ethanol concentration was the same with that ratio of untreated FR to CR of 1:1. Using 0.06 g/g-H2O2-GL-pretreated FR with CR at a ratio of 2:1 resulted in 51.9 g/L ethanol concentration. Moreover, FR pretreated with GL-H2O2 decreased the concentration of byproducts in SSF compared with that obtained in the previous study. The lignin in FR would inhibit enzyme activity and GL-H2O2 is an advantageous pretreatment method to treat FR and high intensity of FR pretreatment increased the final ethanol concentration. The efficiency of ethanol fermentation of was improved when delignification increased. GL-H2O2 is an advantageous pretreatment method to treat FR. As the pretreatment dosage of GL-H2O2 on FR increased, the proportion of lignocellulosic substrates was enhanced in the SSF of the substrate mixture of CR and FR as compared with untreated FR. Moreover, the

  1. The influence of carrier gas on plasma properties and hydrogen peroxide production in a nanosecond pulsed plasma discharge generated in a water-film plasma reactor

    NASA Astrophysics Data System (ADS)

    Wang, Huihui; Wandell, Robert J.; Locke, Bruce R.

    2018-03-01

    The influence of carrier gas (argon and helium) on the properties of a nanosecond pulsed filamentary discharge propagating along the water surface in a water film plasma reactor, and the effects of plasma properties on the formation of hydrogen peroxide (H2O2) are investigated. The plasma properties, including electron density, gas temperature, and plasma volume, and the hydrogen peroxide production rate and energy yield were measured and compared in both argon and helium discharges. The results show that helium plasma is more diffusive compared with the argon plasma, and it has lower electron density and gas temperature but larger volume. The production rates and energy yields of hydrogen peroxide are only slightly higher in the helium plasma although the electron density is much lower. A simple mathematical model with time-dependent fast radical and electron quenching in a small film surrounding the plasma core and with lumped reaction kinetics for H2O2 formation and degradation suggests that the hydroxyl radical (·OH) concentration is approximately two times higher in the argon discharge, but the larger volume of the helium leads to about two times more total ·OH in the helium with correspondingly higher energy yields. The experimental data and model imply that the H2O2 energy yield may increase at lower power (or specific energy density) for both carrier gases.

  2. Inhibition of nitric oxide (NO) production in lipopolysaccharide (LPS)-activated murine macrophage RAW 264.7 cells by the norsesterterpene peroxide, epimuqubilin A.

    PubMed

    Cheenpracha, Sarot; Park, Eun-Jung; Rostama, Bahman; Pezzuto, John M; Chang, Leng Chee

    2010-03-01

    Seven norsesterterpene peroxides: epimuqubilin A (1), muqubilone B (2), unnamed cyclic peroxide ester (3), epimuqubilin B (4), sigmosceptrellin A methyl ester (5), sigmosceptrellin A (6), and sigmosceptrellin B methyl ester (7), isolated from the marine sponge Latrunculia sp., were examined with regard to their effects on nitric oxide (NO) production in lipopolysaccharide (LPS)-activated murine macrophage RAW 264.7 cells. The results indicated epimuqubilin A (1) possessed potent NO inhibitory activity against lipopolysaccharide (LPS)-induced nitric oxide release with an IC(50) value of 7.4 microM, a level three times greater than the positive control, L-N(G)-monomethyl arginine citrate, followed by 6 (sigmosceptrellin A, IC(50) = 9.9 microM), whereas other compounds exhibited only modest activity (Table 1). These compounds did not show appreciable cytotoxicity at their IC(50) values for NO-inhibitory activity. The structure-activity upon NO inhibition could be summarized as follows: (1) a monocyclic carbon skeleton framework was essential for activity, (2) free acids gave higher activity, (3) the orientation of H3-22 with an equatorial position increased activity, and (4) a bicyclic structure reduced activity. This is the first report of a norsesterterpene peroxide with NO-inhibitory activity. In addition, compounds 1-7 were also evaluated for their inhibitory activities in the yeast glycogen synthase kinase-3beta assay. In summary, several norsesterterpene peroxides showed novel biological activities of inhibition in NO production, suggesting that these might provide leads for anti-inflammatory or cancer chemopreventive agents.

  3. Inhibition of Nitric Oxide (NO) Production in Lipopolysaccharide (LPS)-Activated Murine Macrophage RAW 264.7 Cells by the Norsesterterpene Peroxide, Epimuqubilin A

    PubMed Central

    Cheenpracha, Sarot; Park, Eun-Jung; Rostama, Bahman; Pezzuto, John M.; Chang, Leng Chee

    2010-01-01

    Seven norsesterterpene peroxides: epimuqubilin A (1), muqubilone B (2), unnamed cyclic peroxide ester (3), epimuqubilin B (4), sigmosceptrellin A methyl ester (5), sigmosceptrellin A (6), and sigmosceptrellin B methyl ester (7), isolated from the marine sponge Latrunculia sp., were examined with regard to their effects on nitric oxide (NO) production in lipopolysaccharide (LPS)-activated murine macrophage RAW 264.7 cells. The results indicated epimuqubilin A (1) possessed potent NO inhibitory activity against lipopolysaccharide (LPS)-induced nitric oxide release with an IC50 value of 7.4 μM, a level three times greater than the positive control, L-NG-monomethyl arginine citrate, followed by 6 (sigmosceptrellin A, IC50 = 9.9 μM), whereas other compounds exhibited only modest activity (Table 1). These compounds did not show appreciable cytotoxicity at their IC50 values for NO–inhibitory activity. The structure–activity upon NO inhibition could be summarized as follows: (1) a monocyclic carbon skeleton framework was essential for activity, (2) free acids gave higher activity, (3) the orientation of H3-22 with an equatorial position increased activity, and (4) a bicyclic structure reduced activity. This is the first report of a norsesterterpene peroxide with NO–inhibitory activity. In addition, compounds 1–7 were also evaluated for their inhibitory activities in the yeast glycogen synthase kinase-3β assay. In summary, several norsesterterpene peroxides showed novel biological activities of inhibition in NO production, suggesting that these might provide leads for anti-inflammatory or cancer chemopreventive agents. PMID:20411107

  4. Action of UV-A and blue light on enzymes activity and accumulation of lipid peroxidation products in attached and detached frog retinas

    NASA Astrophysics Data System (ADS)

    Lapina, Victoria A.; Doutsov, Alexander E.

    1994-07-01

    The effect of the UV-A and blue light on the accumulation of lipid peroxidation products and activities of succinate dehydrogenase and superoxide dismutase in the retina was examined in eye cup model of dark and light adapted frogs R. temporaria. Retinas were exposed to UV-A radiation (8 mW/cm2) and blue light (10 to 150 mW/cm2) for periods from 5 min to 1 hr. We have measured TBA-active products both in the retina homogenates and in the reaction media. Enzyme activities was measured in the retina homogenates only. The measurements revealed a significant increase in the endogenous and exogenous forms of lipid peroxidation products in the retina of dark adapted frog (1.6+/- 0.4; 1.4+/- 0.3 nmole TBA-active products per mg protein, respectively) compared to light adapted (0.85+/- 0.16; 0.32+/- 0.06 nmole TBA-active products per mg protein, respectively). In the same conditions succinate dehydrogenase activity was decline more than 50% but superoxide dismutase activity didn't decrease. Disorganized inner and outer segments were observed after 40 min exposures. No light microscopic changes were detected after 5 min exposures. Light damage was significantly higher in the retina of dark adapted frog. The results indicate that the retina from eye cup of dark adapted frog is more susceptible to UV-A and blue light damages.

  5. The elucidation and quantification of the decomposition products of sodium dithionite and the detection of peroxide vapors with thin films

    NASA Astrophysics Data System (ADS)

    James, Travis Houston

    Sodium dithionite (Na2S2O4) is an oxidizable sulfur oxyanion often employed as a reducing agent in environmental and synthetic chemistry. When exposed to the atmosphere, dithionite degrades through a series of decomposition reactions to form a number of compounds, with the primary two being bisulfite (HSO32-) and thiosulfate (S 2O32-). Ten samples of sodium dithionite ranging from brand new to nearly fifty years old were analyzed using ion chromatography; from this, a new quantification method for dithionite and thiosulfate was achieved and statistically validated against the current three iodometric titration method used industrially. Additional sample analysis with Raman spectroscopy of solid and dissolved samples identified unique compounds in the oldest samples, including dithionate (S2O6 2-) and tetrathionate (S4O62-). Additionally, titania nanoparticles in a hydroxypropyl cellulose matrix were used to prepare films on polycarbonate slides and coatings on cellulose papers. The exposure of these materials to hydrogen peroxide gas led to the development of an intense yellow color. Using an inexpensive web camera and a tungsten lamp to measure the reflected light, first-order behavior in the color change was observed when exposed to peroxide vapor of less than 50 ppm. For 50 mass percent titania nanoparticles in hydroxypropyl cellulose films on polycarbonate, the detection limit was estimated to be 90 ppm after a 1-minute measurement and 1.5 ppm after a 1-hour integration. The coatings on the filter paper had a threefold higher sensitivity compared to the films, with a detection limit of 5.4 ppm peroxide for a 1-minute measurement and 0.09 ppm peroxide for a 1-hour integration period. Further experimentation with the effects of acid loading on the filter paper coatings identified these as possible sensors for organic peroxides. With the addition of sulfuric acid, the support was changed from cellulose to glass microfiber or silica. This coatings showing increased

  6. Folic acid protects against lead acetate-induced hepatotoxicity by decreasing NF-κB, IL-1β production and lipid peroxidation mediataed cell injury.

    PubMed

    Abd Allah, Eman S H; Badary, Dalia M

    2017-03-01

    Folic acid plays an important role in cellular metabolic activities. The present study was designed to investigate the protective effect of folic acid against lead acetate-induced hepatotoxicity. Twenty four male Wistar albino rats were randomly divided into four groups, six animals each. Negative control group received the vehicle, positive control group received 1mg/kg folic acid for five consecutive days/week for 4 weeks orally, lead-exposed group received 10mg/kg lead acetate intraperitoneally (IP) for five consecutive days/week for 4 weeks, and lead-treated group received 10mg/kg lead acetate IP and 1mg/kg folic acid orally for five consecutive days/week for 4 weeks concurrently. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and γ- glutamyltransferase (GGT) were measured. Hepatic total peroxide and interleukin-1β (IL-1β) were also investigated. Histopathological studies using hematoxylin-eosin (H&E) and periodic acid shiff's (PAS) were carried out. The expression of nuclear factor kappa B (NF-κB) was evaluated using immunohistochemistry. Serum AST, ALT and GGT and hepatic total peroxide and IL-1β were significantly increased in lead-exposed group and were positively correlated with hepatic lead level. Moreover, lead-exposed rats showed hydropic degeneration, nuclear vesiculation, high lymphocytic infiltration, depletion of glycogen content and NF-κB expression. Concomitant folic acid administration resulted in a significant alleviation of biochemical and structural alteration-induced by lead. This was associated with reduction of hepatic total peroxide and IL-1β and reduction of NF-κB expression. In conclusion, folic acid protects against lead acetate-induced hepatotoxicity by decreasing NF-κB, IL-1β production and lipid peroxidation mediataed cell injury. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Protein oxidation and peroxidation

    PubMed Central

    Davies, Michael J.

    2016-01-01

    Proteins are major targets for radicals and two-electron oxidants in biological systems due to their abundance and high rate constants for reaction. With highly reactive radicals damage occurs at multiple side-chain and backbone sites. Less reactive species show greater selectivity with regard to the residues targeted and their spatial location. Modification can result in increased side-chain hydrophilicity, side-chain and backbone fragmentation, aggregation via covalent cross-linking or hydrophobic interactions, protein unfolding and altered conformation, altered interactions with biological partners and modified turnover. In the presence of O2, high yields of peroxyl radicals and peroxides (protein peroxidation) are formed; the latter account for up to 70% of the initial oxidant flux. Protein peroxides can oxidize both proteins and other targets. One-electron reduction results in additional radicals and chain reactions with alcohols and carbonyls as major products; the latter are commonly used markers of protein damage. Direct oxidation of cysteine (and less commonly) methionine residues is a major reaction; this is typically faster than with H2O2, and results in altered protein activity and function. Unlike H2O2, which is rapidly removed by protective enzymes, protein peroxides are only slowly removed, and catabolism is a major fate. Although turnover of modified proteins by proteasomal and lysosomal enzymes, and other proteases (e.g. mitochondrial Lon), can be efficient, protein hydroperoxides inhibit these pathways and this may contribute to the accumulation of modified proteins in cells. Available evidence supports an association between protein oxidation and multiple human pathologies, but whether this link is causal remains to be established. PMID:27026395

  8. 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.

  9. Polyphenols from Lonicera caerulea L. berry attenuate experimental nonalcoholic steatohepatitis by inhibiting proinflammatory cytokines productions and lipid peroxidation.

    PubMed

    Wu, Shusong; Yano, Satoshi; Hisanaga, Ayami; He, Xi; He, Jianhua; Sakao, Kozue; Hou, De-Xing

    2017-04-01

    Nonalcoholic steatohepatitis (NASH) is a common disease, which is closely associated with inflammation and oxidative stress, and Lonicera caerulea L. polyphenols (LCP) are reported to possess both antioxidant and anti-inflammatory properties. This study aimed to investigate the protective effects and mechanisms of LCP on NASH in a high-fat diet plus carbon tetrachloride (CCL 4 ) induced mouse model. Mice were fed with high-fat diet containing LCP (0.5-1%) or not, and then administrated with CCL 4 to induce NASH. Liver sections were stained by hematoxylin-eosin stain, serum transaminases and lipids were measured by clinical analyzer, insulin was examined by ELISA, cytokines were determined by multiplex technology, and hepatic proteins were detected by Western blotting. LCP improved histopathological features of NASH with lower levels of lipid peroxidation and cytokines including granulocyte colony-stimulating factor, IL-3, IL-4, macrophage inflammatory protein-1β, IL-6, IL-5, keratinocyte-derived cytokine, tumor necrosis factor-alpha, IL-2, IL-1β, monocytes chemotactic protein-1, IL-13, IFN-γ, IL-10, IL-12(p70), IL-1α, eotaxin, granulocyte-macrophage colony-stimulating factor, macrophage inflammatory protein-1α, IL-17, and RANTES. Further molecular analysis revealed that LCP increased the expression of nuclear factor (erythroid-derived 2)-like 2 and manganese-dependent superoxide dismutase, but decreased forkhead box protein O1 and heme oxygenase-1 in the liver of NASH mice. Dietary supplementation of LCP ameliorates inflammation and lipid peroxidation by upregulating nuclear factor (erythroid-derived 2)-like 2 and manganese-dependent superoxide dismutase, and downregulating forkhead box protein O1 and heme oxygenase-1 in NASH. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. 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.

  11. Influence of aerobic fitness on age-related lymphocyte DNA damage in humans: relationship with mitochondria respiratory chain and hydrogen peroxide production

    PubMed Central

    Peixoto, Francisco M.; Soares, Jorge F.; Figueiredo, Pedro A.; Leitão, José C.; Gaivão, Isabel; Duarte, José A.

    2010-01-01

    The aim of this study was to analyze the influence of aerobic fitness (AF) on age-related lymphocyte DNA damage in humans, giving special attention to the role of the mitochondrial respiratory chain and hydrogen peroxide production. Considering age and AF (as assessed by VO2max), 66 males (19–59 years old) were classified as high fitness (HF) or low fitness (LF) and distributed into one of the following groups: young adults (19–29 years old), adults (30–39 years old), and middle-aged adults (over 40 years old). Peripheral lymphocytes obtained at rest were used to assess DNA damage (strand breaks and formamidopyrimidine DNA glycosylase (FPG) sites through the comet assay), activity of mitochondrial complexes I and II (polarographically measured), and the hydrogen peroxide production rate (assayed by fluorescence). Results revealed a significant interaction between age groups and AF for DNA strand breaks (F = 8.415, p = .000), FPG sites (F = 11.766, p = .000), mitochondrial complex I activity (F = 7.555, p = .000), and H2O2 production (F = 7.500, p = .000). Except for mitochondrial complex II activity, the age variation of the remaining parameters was significantly attenuated by HF. Considering each AF level, an increase in DNA strand breaks and FPG sites with age (r = 0.655, p = 0.000, and r = 0.738, p = 0.000, respectively) was only observed in LF. Moreover, decreased mitochondrial complex I activity with age (r = −.470, p = .009) was reported in LF. These results allow the conclusion that high AF seems to play a key role in attenuating the biological aging process. PMID:20640548

  12. Detoxication of base propenals and other alpha, beta-unsaturated aldehyde products of radical reactions and lipid peroxidation by human glutathione transferases.

    PubMed Central

    Berhane, K; Widersten, M; Engström, A; Kozarich, J W; Mannervik, B

    1994-01-01

    Radiation and chemical reactions that give rise to free radicals cause the formation of highly cytotoxic base propenals, degradation products of DNA. Human glutathione transferases (GSTs; RX:glutathione R-transferase, EC 2.5.1.18) of classes Alpha, Mu, and Pi were shown to promote the conjugation of glutathione with base propenals and related alkenes. GST P1-1 was particularly active in catalyzing the reactions with the propenal derivatives, and adenine propenal was the substrate giving the highest activity. The catalytic efficiency of GST P1-1 with adenine propenal (kcat/Km = 7.7 x 10(5) M-1.s-1) is the highest so far reported with any substrate for this enzyme. In general, GST A1-1 and GST M1-1, in contrast to GST P1-1, were more active with 4-hydroxyalkenals (products of lipid peroxidation) than with base propenals. The adduct resulting from the Michael addition of glutathione to the alkene function of one of the base propenals (adenine propenal) was identified by mass spectrometry. At the cellular level, GST P1-1 was shown to provide protection against alpha, beta-unsaturated aldehydes. GST P1-1 added to the culture medium of HeLa cells augmented the protective effect of glutathione against the toxicity of adenine propenal and thymine propenal. No protective effect of the enzyme was observed in the presence of the competitive inhibitor S-hexylglutathione. GST P1-1 introduced into Hep G2 cells by electroporation was similarly found to increase their resistance to acrolein. The results show that glutathione transferases may play an important role in cellular detoxication of electrophilic alpha, beta-unsaturated carbonyl compounds produced by radical reactions, lipid peroxidation, ionizing radiation, and drug metabolism. Images PMID:8108434

  13. PRECIPITATION OF PLUTONOUS PEROXIDE

    DOEpatents

    Barrick, J.G.; Manion, J.P.

    1961-08-15

    A precipitation process for recovering plutonium values contained in an aqueous solution is described. In the process for precipitating plutonium as plutonous peroxide, hydroxylamine or hydrazine is added to the plutoniumcontaining solution prior to the addition of peroxide to precipitate plutonium. The addition of hydroxylamine or hydrazine increases the amount of plutonium precipitated as plutonous peroxide. (AEC)

  14. Photoelectrochemical Hydrogen Peroxide Production from Water on a WO3 /BiVO4 Photoanode and from O2 on an Au Cathode Without External Bias.

    PubMed

    Fuku, Kojiro; Miyase, Yuta; Miseki, Yugo; Funaki, Takashi; Gunji, Takahiro; Sayama, Kazuhiro

    2017-05-18

    The photoelectrochemical production and degradation properties of hydrogen peroxide (H2 O2 ) were investigated on a WO3 /BiVO4 photoanode in an aqueous electrolyte of hydrogen carbonate (HCO3- ). High concentrations of HCO3- species rather than CO32- species inhibited the oxidative degradation of H2 O2 on the WO3 /BiVO4 photoanode, resulting in effective oxidative H2 O2 generation and accumulation from water (H2 O). Moreover, the Au cathode facilitated two-electron reduction of oxygen (O2 ), resulting in reductive H2 O2 production with high current efficiency. Combining the WO3 /BiVO4 photoanode with a HCO3- electrolyte and an Au cathode also produced a clean and promising design for a photoelectrode system specializing in H2 O2 production (ηanode (H2 O2 )≈50 %, ηcathode (H2 O2 )≈90 %) even without applied voltage between the photoanode and cathode under simulated solar light through a two-photon process; this achieved effective H2 O2 production when using an Au-supported porous BiVO4 photocatalyst sheet. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Inhibitory effects of Zataria multiflora essential oil and its main components on nitric oxide and hydrogen peroxide production in lipopolysaccharide-stimulated macrophages.

    PubMed

    Kavoosi, Gholamreza; Teixeira da Silva, Jaime A; Saharkhiz, Mohammad J

    2012-10-01

    Zataria multiflora is an aromatic plant that is used in flavouring and preserving foods and also used as an antispasmodic, anaesthetic and antinociceptive agent. In this study, the effects of Z. multiflora essential oil on nitric oxide (NO) and hydrogen peroxide (H(2) O(2) ) production in lipopolysaccharide (LPS)-stimulated macrophages was investigated. Z. multiflora essential oil was extracted by water-distillation, analysed by GC-MS and then the effect of the essential oil on NO and H(2) O(2) production was investigated. Carvacrol (52%), thymol (16%) and p-cymene (10%) were the main components of the oil. The IC50 (concentration providing 50% inhibition) for reactive oxygen scavenging was estimated to be 5.7, 3 and 4.2 µg/ml for the essential oil, thymol and carvacrol, respectively, while the corresponding IC50 values for reactive nitrogen scavenging were estimated to be 8.6, 4.7 and 6.6 µg/ml. Z. multiflora essential oil, thymol, and carvacrol significantly reduced NO and H(2) O(2) production as well as NO synthase and NADH oxidase activity in LPS-stimulated murine macrophages while p-cymene did not show any antioxidant activity. Z. multiflora essential oil has the potential to be used in the therapy of oxidative damage. © 2012 The Authors. JPP © 2012 Royal Pharmaceutical Society.

  16. Inhibitory effects of Zataria multiflora essential oil and its main components on nitric oxide and hydrogen peroxide production in glucose-stimulated human monocyte.

    PubMed

    Kavoosi, Gholamreza; Teixeira da Silva, Jaime A

    2012-09-01

    The inhibitory effects of Zataria multiflora essential oil on nitric oxide (NO) and hydrogen peroxide (H(2)O(2)) production were examined in human monocytes cultured in the presence of 20mM glucose. Z. multiflora essential oil was extracted by water-distillation and then analyzed by GC-MS. Carvacrol (29.2%), thymol (25.4%), p-cymene (11.2%), linalool (9.6%) and γ-terpinene (8%) were the main components detected in the essential oil. Cells cultured in the presence of 20mM glucose showed an increase in NO and H(2)O(2) production as well as NO synthase (NOS) and NADH oxidase (NOX) activities compared to cells cultured in the presence of 5mM glucose. Pretreatment with Z. multiflora essential oil, carvacrol and thymol reduced NO and H(2)O(2) production as well as NOS and NOX activities in those cells cultured in the presence of 20mM glucose. However, p-cymene, linalool and γ-terpinene did not show any such activities. Accordingly, it was concluded that Z. multiflora can reduce oxidative stress and can be used in the therapy of oxidative damage accompanying hyperglycemia and some inflammatory conditions. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Effect of Cd⁺² on phosphate solubilizing abilities and hydrogen peroxide production of soil-borne micromycetes isolated from Phragmites australis-rhizosphere.

    PubMed

    Zúñiga-Silva, Jose Roberto; Chan-Cupul, Wilberth; Kuschk, Peter; Loera, Octavio; Aguilar-López, Ricardo; Rodríguez-Vázquez, Refugio

    2016-03-01

    The aims of this work were to evaluate the phosphate-solubilization and hydrogen peroxide (H2O2) production by the soil-borne micromycetes, Aspergillus japonicus, Penicillium italicum and Penicillium dipodomyicola, isolated from Phragmites australis rhizosphere and to study the effect of several concentrations of Cadmium (Cd(2+)) on both variables. Our results showed that P. italicum achieved a higher P-solubilization and H2O2 production than A. japonicus and P. dipodomyicola, as only P. italicum showed a positive correlation (R(2) = 0.71) between P-solubilization and H2O2 production. In dose-response assays, P. italicum was also more tolerant to Cd(2+) (0.31 mM) in comparison to A. japonicus (0.26 mM). Analysis of the 2(4) factorial experimental design showed that P-solubilization by P. italicum was negatively affected by increases in Cd(2+) (p = 0.04) and yeast extract (p = 0.02) in the culture medium. The production of H2O2 was positively affected only by glucose (p = 0.002). Fungal biomass production was reduced significantly (p = 0.0009) by Cd(2+) and increased (p = 0.0003) by high glucose concentration in the culture medium. The tolerance and correlation between P-solubilization and H2O2 production in the presence of Cd(2+) was strain and species dependent. The effects of Cd(2+), glucose, ammonium sulfate and yeast extract on those variables were evaluated through a two-level factorial design. P. italicum is promising for P-solubilization in soils contaminated with Cd(2+) and may be an alternative for manufacture of biofertilizers to replace chemical fertilizers.

  18. Comparison of protective effect of ascorbic acid on redox and endocannabinoid systems interactions in in vitro cultured human skin fibroblasts exposed to UV radiation and hydrogen peroxide.

    PubMed

    Gęgotek, Agnieszka; Bielawska, Katarzyna; Biernacki, Michał; Zaręba, Ilona; Surażyński, Arkadiusz; Skrzydlewska, Elżbieta

    2017-05-01

    The mechanisms of biological activity of commonly used natural compounds are constantly examined. Therefore, the aim of this study was to compare ascorbic acid efficacy in counteracting the consequences of UV and hydrogen peroxide treatment on lipid mediators and their regulative action on antioxidant abilities. Skin fibroblasts exposed to UVA and UVB irradiation, treated with hydrogen peroxide and ascorbic acid. The redox system was estimated through reactive oxygen species (ROS) generation (electron spin resonance spectrometer) and antioxidants level/activity (HPLC/spectrometry) which activity was evaluated by the level of phospholipid metabolites: 4-hydroxynonenal, malondialdehyde, 8-isoprostanes and endocannabinoids (GC/LC-MS) in the human skin fibroblasts. Protein and DNA oxidative modifications were also determined (LC). The expression of nuclear factor erythroid 2-related factor 2 (Nrf2), its activators and inhibitors as well as pro/anti-apoptotic proteins and endocannabinoid receptors was examined (Western blot) and collagen metabolism was evaluated by collagen biosynthesis and prolidase activity (spectrometry). UVA and UVB irradiation and hydrogen peroxide treatment enhanced activity of xanthine and NADPH oxidases resulting in ROS generation as well as diminution of antioxidant phospholipid protection (glutathione peroxidase-glutathione-vitamin E), what led to increased lipid peroxidation and decreased endocannabinoids level. Dysregulation of cannabinoid receptors expression and environment of transcription factor Nrf2 caused apoptosis induction. Ascorbic acid partially prevented ROS generation, antioxidant capacity diminution and endocannabinoid systems disturbances but only slightly protected macromolecules such as phospholipid, protein and DNA against oxidative modifications. However, ascorbic acid significantly prevented decrease in collagen type I biosynthesis. Ascorbic acid in similar degree prevents UV (UVA and UVB) and hydrogen peroxide

  19. Ingestion of the anti-bacterial agent, gemifloxacin mesylate, leads to increased gst activity and peroxidation products in hemolymph of Galleria mellonella l. (lepidoptera: pyralidae).

    PubMed

    Erdem, Meltem; Küçük, Ceyhun; Büyükgüzel, Ender; Büyükgüzel, Kemal

    2016-12-01

    Gemifloxacin mesylate (GEM) is a synthetic, fourth-generation fluoroquinolone antibacterial antibiotic that has a broad spectrum of activity against bacteria. GEM inhibits DNA synthesis by inhibiting DNA gyrase and topoisomerase IV activities. Recent research into insect nutrition and mass-rearing programs, in which antibiotics are incorporated into the culture media to maintain diet quality, raised a question of whether clinical antibiotics influence the health or biological performance of the insects that ingest these compounds. Because some antibiotics are pro-oxidant compounds, we addressed the question with experiments designed to assess the effects of GEM (mesylate salt) on oxidative stress indicators, using Galleria mellonella larvae. The insects were reared from first-instar larvae to adulthood on artificial diets amended with GEM at 0.001, 0.01, 0.1, or 1.0%. Feeding on the 1% diets led to significantly increased hemolymph contents of the lipid peroxidation product, malondialdehyde and protein oxidation products, protein carbonyl. All GEM concentrations led to increased hemolymph glutathione S-transferase activity. We inferred that although it was not directly lethal to G. mellonella larvae, dietary exposure to GEM exerts measurable oxidative damage, possibly on insects generally. Long-term, multigenerational effects remain unknown. © 2016 Wiley Periodicals, Inc.

  20. PEP-1-frataxin significantly increases cell proliferation and neuroblast differentiation by reducing lipid peroxidation in the mouse dentate gyrus.

    PubMed

    Kim, Woosuk; Kim, Dae Won; Shin, Bich Na; Yoo, Dae Young; Nam, Sung Min; Kim, Mi Jin; Choi, Jung Hoon; Yoon, Yeo Sung; Won, Moo-Ho; Choi, Soo Young; Hwang, In Koo

    2011-12-01

    Frataxin plays important roles in the mitochondrial respiratory chain and in the differentiation of neurons during early development. In this study, we observed the effects of frataxin on cell proliferation and neuroblast differentiation in the mouse hippocampal dentate gyrus. For this, we constructed an expression vector, PEP-1, that was fused with frataxin to create a PEP-1-frataxin fusion protein that easily penetrated frataxin into the blood-brain barrier. Three mg/kg PEP-1-frataxin was intraperitoneally administered to mice once a day for 2 weeks. The administration of PEP-1 alone did not result in any significant changes in the number of Ki67-positive cells and doublecortin (DCX)-immunoreactive neuroblasts in the mouse dentate gyrus. However, the administration of PEP-1-frataxin significantly increased the number of Ki67-positive cells and DCX-immunoreactive neuroblasts in the mouse dentate gyrus. In addition, PEP-1-frataxin significantly reduced 4-hydroxynonenal protein levels and malondialdehyde formation, while Cu, Zn-superoxide dismutase protein levels were maintained. These results suggest that frataxin effectively increased cell proliferation and neuroblast differentiation by decreasing lipid peroxidation in the dentate gyrus.

  1. A Green Method to Determine VUV (185 nm) Fluence Rate Based on Hydrogen Peroxide Production in Aqueous Solution.

    PubMed

    Yang, Laxiang; Li, Mengkai; Li, Wentao; Bolton, James R; Qiang, Zhimin

    2018-02-19

    A mini-fluidic vacuum ultraviolet/ultraviolet (VUV/UV) photoreaction system (MVPS) was developed in our previous study. Based on the MVPS, a green method to determine VUV fluence rate has been developed using the production rate of H 2 O 2 when water is exposed to 185 nm VUV. The H 2 O 2 production followed pseudo-zero-order reaction kinetics well over the first 10 min of VUV/UV exposure. This new method was well calibrated with a standard cis-cyclooctene cis-trans photoisomerization actinometer as recommended by the International Union of Pure and Applied Chemistry. The apparent quantum yield for H 2 O 2 production by 185 nm VUV irradiation of water was determined to be 0.024 ± 0.002. As the solution pH increased from 5.0 to 8.0, the H 2 O 2 production rate decreased from 0.83 to 0.40 μM min -1 . Dissolved oxygen had a negligible influence on the H 2 O 2 production. This study proposes a novel VUV fluence rate determination method with advantages of non-toxicity, low detection limits, low costs and convenience, and it can be used as a good alternative to traditional actinometers. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  2. Induction of antroquinonol production by addition of hydrogen peroxide in the fermentation of Antrodia camphorata S-29.

    PubMed

    Xia, Yongjun; Zhou, Xuan; Wang, Guangqiang; Zhang, Bobo; Xu, Ganrong; Ai, Lianzhong

    2017-01-01

    Antroquinonol have significantly anti-tumour effects on various cancer cells. There is still lack of reports on regulation of environmental factors on antroquinonol production by Antrodia camphorata. An effective submerged fermentation method was employed to induce antroquinonol with adding H2 O2 . The production of antroquinonol was 57.81 mg L-1 after fermentation for 10 days when adding 25 mmol L-1 H2 O2 at day 4 of the fermentation process. Then, antroquinonol was further increased to 80.10 mg L-1 with cell productivity of 14.94 mg g-1 dry mycelium when the feeding rate of H2 O2 was adjusted to 0.2 mmol L-1 h-1 in the 7 L fermentation bioreactor. After inhibiting the generation of reactive oxygen species with the inhibitor diphenyleneiodoium, the synthesis of antroquinonol from A. camphorata was significantly reduced, and the yield was only 3.3 mg L-1 . The results demonstrated that addition of H2 O2 was a very effective strategy to induce and regulate the synthesis of antroquinonol in submerged fermentation. Reactive oxygen species generated by H2 O2 during fermentation caused oxidative stress, which induced the synthesis of antroquinonol and other chemical compounds. Moreover, it is very beneficial process to improve production and diversity of the active compounds during liquid fermentation of A. camphorata mycelium. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  3. Isolation, taxonomic identification and hydrogen peroxide production by Lactobacillus delbrueckii subsp. lactis T31, isolated from Mongolian yoghurt: inhibitory activity on food-borne pathogens.

    PubMed

    Batdorj, B; Trinetta, V; Dalgalarrondo, M; Prévost, H; Dousset, X; Ivanova, I; Haertlé, T; Chobert, J-M

    2007-09-01

    The aim of this work was to isolate lactic acid bacteria (LAB) strains from Mongolian tarag (a traditionally homemade yoghurt) displaying antimicrobial activities against food-borne pathogens, identify inhibitory substances and study the kinetics of their production. Inhibitory substance-producing bacterial strains were isolated from tarag. From 300 bacterial clones, 31 were able to inhibit the growth of the indicator strain Lactobacillus bulgaricus 340. One of the most active strains was identified as Lactobacillus delbrueckii subsp. lactis strain T31 by using cluster analysis of amplified fragment length polymorphism (AFLP) DNA fingerprints. The antimicrobial substance was inactivated by catalase, demonstrating the production of hydrogen peroxide (H(2)O(2)). Production of H(2)O(2) was studied under aerated and nonaerated culture conditions. The amount of H(2)O(2) in the culture supernatant increased during bacterial growth and reached a maximum (5.12 mmol l(-1)) at the early stationary phase under aerated conditions (agitated cultures). H(2)O(2) was not detected in the culture performed without agitation. In mixed cultures performed in milk with either Lact. delbrueckii subsp. lactis T31 in the presence of Escherichia coli, or Lact. delbrueckii subsp. lactis T31 in the presence of Listeria innocua under aerated and nonaerated conditions, a significant decrease in pathogen count was observed in aerated cultures. The significant decrease in Listeria viability observed in aerated mixed cultures of Lact. delbrueckii subsp. lactis T31 is mainly because of H(2)O(2) production. Lactobacillus delbrueckii subsp. lactis T31 could be used as a protective culture in food industries or as a probiotic to prevent intestinal and urogenital infections.

  4. Sites of Superoxide and Hydrogen Peroxide Production by Muscle Mitochondria Assessed ex Vivo under Conditions Mimicking Rest and Exercise*

    PubMed Central

    Goncalves, Renata L. S.; Quinlan, Casey L.; Perevoshchikova, Irina V.; Hey-Mogensen, Martin; Brand, Martin D.

    2015-01-01

    The sites and rates of mitochondrial production of superoxide and H2O2 in vivo are not yet defined. At least 10 different mitochondrial sites can generate these species. Each site has a different maximum capacity (e.g. the outer quinol site in complex III (site IIIQo) has a very high capacity in rat skeletal muscle mitochondria, whereas the flavin site in complex I (site IF) has a very low capacity). The maximum capacities can greatly exceed the actual rates observed in the absence of electron transport chain inhibitors, so maximum capacities are a poor guide to actual rates. Here, we use new approaches to measure the rates at which different mitochondrial sites produce superoxide/H2O2 using isolated muscle mitochondria incubated in media mimicking the cytoplasmic substrate and effector mix of skeletal muscle during rest and exercise. We find that four or five sites dominate during rest in this ex vivo system. Remarkably, the quinol site in complex I (site IQ) and the flavin site in complex II (site IIF) each account for about a quarter of the total measured rate of H2O2 production. Site IF, site IIIQo, and perhaps site EF in the β-oxidation pathway account for most of the remainder. Under conditions mimicking mild and intense aerobic exercise, total production is much less, and the low capacity site IF dominates. These results give novel insights into which mitochondrial sites may produce superoxide/H2O2 in vivo. PMID:25389297

  5. Characterization of 2'-deoxyadenosine adducts derived from 4-oxo-2-nonenal, a novel product of lipid peroxidation.

    PubMed

    Lee, S H; Rindgen, D; Bible, R H; Hajdu, E; Blair, I A

    2000-07-01

    Analysis of the reaction between 2'-deoxyadenosine and 4-oxo-2-nonenal by liquid chromatography/mass spectrometry revealed the presence of three major products (adducts A(1), A(2), and B). Adducts A(1) and A(2) were isomeric; they interconverted at room temperature, and they each readily dehydrated to form adduct B. The mass spectral characteristics of adduct B obtained by collision-induced dissociation coupled with multiple tandem mass spectrometry were consistent with those expected for a substituted etheno adduct. The structure of adduct B was shown by NMR spectroscopy to be consistent with the substituted etheno-2'-deoxyadenosine adduct 1' '-[3-(2'-deoxy-beta-D-erythropentafuranosyl)-3H-imidazo[2, 1-i]purin-7-yl]heptane-2' '-one. Unequivocal proof of structure came from the reaction of adducts A(1) and A(2) (precursors of adduct B) with sodium borohydride. Adducts A(1) and A(2) each formed the same reduction product, which contained eight additional hydrogen atoms. The mass spectral characteristics of this reduction product established that the exocyclic amino group (N(6)) of 2'-deoxyadenosine was attached to C-1 of the 4-oxo-2-nonenal. The reaction of 4-oxo-2-nonenal with calf thymus DNA was also shown to result in the formation of substituted ethano adducts A(1) and A(2) and substituted etheno adduct B. Adduct B was formed in amounts almost 2 orders of magnitude greater than those of adducts A(1) and A(2). This was in keeping with the observed stability of the adducts. The study presented here has provided additional evidence which shows that 4-oxo-2-nonenal reacts efficiently with DNA to form substituted etheno adducts.

  6. Measurement of dark, particle-generated superoxide and hydrogen peroxide production and decay in the subtropical and temperate North Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Roe, Kelly L.; Schneider, Robin J.; Hansel, Colleen M.; Voelker, Bettina M.

    2016-01-01

    Reactive oxygen species (ROS), which include the superoxide radical (O2-) and hydrogen peroxide (H2O2), are thought to be generated mostly through photochemical reactions and biological activity in seawater and can influence trace metal speciation in the ocean. This study reports the results of an intercomparison of two methods to measure particle-generated [O2-] in seawater samples, as well as measurements of particle-generated O2- and H2O2 concentrations, decay kinetics, and dark production rates in seawater samples at Station ALOHA and (O2- only) in the southern California Current Ecosystem. O2- was measured using two different methods relying on chemiluminescence detection. The first method measured the difference between steady-state [O2-] in filtered and unfiltered seawater, while the second method (standard method) measured O2- decay to baseline in freshly filtered seawater. Because both methods detected [O2-] relative to the background signal from filtered seawater, both should have measured [O2-] generated by particles (presumably biota). However, the O2- concentrations determined by the first method were always much smaller than those obtained from the second (standard) method. Follow-up laboratory and field experiments showed that the increased signal in the standard method was due to a filtration artifact that could neither be eliminated nor consistently accounted for under the tested conditions. We therefore recommend the first method for measuring particle-generated [O2-]. Measured by this method, Station ALOHA had particle-generated O2- concentrations that ranged from undetectable to 0.02 nM, with production rates less than 0.6 nM hr-1 and decay rate coefficients from 0.003 to 0.014 s-1. The southern California Current Ecosystem had particle-generated O2- concentrations that ranged from undetectable to 0.05 nM, with production rates up to 4.7 nM hr-1 and decay rate coefficients from 0.006 to 0.017 s-1. H2O2 concentrations were measured by

  7. Seasonal dynamics of products of lipid peroxidation in liver of bank vole (Myodes glareolus) under conditions of environmental pollution by heavy metals.

    PubMed

    Zadyra, S V; Lukashov, D V

    2013-01-01

    The presented research involves the integral assessment of biochemistry indexes of natural populations of voles under conditions of environmental pollution by heavy metals. The raised content of mobile forms of Pb, Cd, Cr, Ni and Co in soils was revealed for a distance of 500 m to the south-west of Tripillya Thermal Power Plant (TPP) (Kyiv region, Ukraine). It considerably (up to 3-5 times) exceeds the levels in the territory of Kaniv Nature Reserve (Cherkassy region, Ukraine). The territory of National Nature Park "Holosiivsky" (Kyiv, Ukraine) is characterized by rather increased content of active form of investigated heavy metals, especially Pb. The increase of the concentration of diene conjugates (up to 7-10 times) and thiobarbituric acid (TBA) active compounds (up to 2-3 times) in the liver of bank vole (Myodes glareolus) polluted by heavy metals has been found. The insignificant increase of the content of Schiff bases in liver homogenate of voles in the region of impact of the Tripillya TPP (2 times in spring and summer, 3 times - in autumn) was detected. Seasonal dynamics of the maintenance of lipid peroxidation products has been revealed. The registered changes of biochemical indicators evidence for availability of biochemical stress in the bank vole organism in the region of influence of the Tripillya TPP.

  8. Effect of injected yeast glucan on the activity of macrophages in Atlantic salmon, Salmo salar L., as evaluated by in vitro hydrogen peroxide production and phagocytic capacity.

    PubMed Central

    Brattgjerd, S; Evensen, O; Lauve, A

    1994-01-01

    A prepared polysaccharide from the cell wall of yeast, M-Glucan, has previously been demonstrated to have immunostimulatory effects in salmonids as observed by enhanced in vivo non-specific disease resistance in Atlantic salmon, Salmo salar L., and increased in vitro bactericidal activity of rainbow trout, Oncorhynchus mykiss (Walbaum), macrophages. In the present study M-Glucan was injected intraperitoneally into Atlantic salmon and the effect on core components in the non-specific part of the immune system was observed. The hydrogen peroxide (H2O2) production of isolated head kidney macrophages from glucan-injected fish was measured 3 and 6 weeks after M-Glucan treatment and was increased at both time-points upon phorbol myristate acetate-(PMA) triggering. Without PMA triggering the difference was only significant 3 weeks after glucan injection when compared to a control group injected with saline. In a phagocytic assay with macrophages and Vibrio salmonicida the initial uptake of bacteria was elevated at both 3 and 6 weeks after glucan treatment. There was no significant difference when uptake of another fish pathogenic bacteria, Renibacterium salmoninarum, was studied. Treatment of Atlantic salmon with M-Glucan also resulted in enhanced serum lysozyme activity in week 3 of the experimental period. The results indicate that M-Glucan elevates the activity of the non-specific part of the immune system and the use of M-Glucan as an immunostimulant is discussed. PMID:7835949

  9. Cr(VI) reduction by gluconolactone and hydrogen peroxide, the reaction products of fungal glucose oxidase: Cooperative interaction with organic acids in the biotransformation of Cr(VI).

    PubMed

    Romo-Rodríguez, Pamela; Acevedo-Aguilar, Francisco Javier; Lopez-Torres, Adolfo; Wrobel, Kazimierz; Wrobel, Katarzyna; Gutiérrez-Corona, J Félix

    2015-09-01

    The Cr(VI) reducing capability of growing cells of the environmental A. tubingensis Ed8 strain is remarkably efficient compared to reference strains A. niger FGSC322 and A. tubingensis NRRL593. Extracellular glucose oxidase (GOX) activity levels were clearly higher in colonies developed in solid medium and in concentrated extracts of the spent medium of liquid cultures of the Ed8 strain in comparison with the reference strains. In addition, concentrated extracts of the spent medium of A. tubingensis Ed8, but not those of the reference strains, exhibited the ability to reduce Cr(VI). In line with this observation, it was found that A. niger purified GOX is capable of mediating the conversion of Cr(VI) to Cr(III) in a reaction dependent on the presence of glucose that is stimulated by organic acids. Furthermore, it was found that a decrease in Cr(VI) may occur in the absence of the GOX enzyme, as long as the reaction products gluconolactone and hydrogen peroxide are present; this conversion of Cr(VI) is stimulated by organic acids in a reaction that generates hydroxyl radicals, which may involve the formation of an intermediate peroxichromate(V) complex. These findings indicated that fungal glucose oxidase acts an indirect chromate reductase through the formation of Cr(VI) reducing molecules, which interact cooperatively with other fungal metabolites in the biotransformation of Cr(VI). Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Enhanced potential for oxidative stress in hyperinsulinemic rats: imbalance between hepatic peroxisomal hydrogen peroxide production and decomposition due to hyperinsulinemia.

    PubMed

    Xu, L; Badr, M Z

    1999-04-01

    Oxidative stress is involved in aging and age-related diseases. Several metabolic alterations similar to those encountered with aging and age-related diseases have been observed in response to hyperinsulinemia. Surprisingly, this metabolic derangement diminished hepatic peroxisomal beta-oxidation which is a major source of H2O2 production in the liver, suggesting a protective effect against oxidative stress. However, the impact of hyperinsulinemia on the balance between H2O2 production and elimination in the liver is not known. Consequently, this study was undertaken to evaluate the effect of sustained high serum insulin levels on the activity of hepatic catalase, a peroxisomal antioxidant enzyme involved in the decomposition of H2O2. Male Sprague-Dawley rats received intravenous infusion of either 30% glucose, 30% galactose or normal saline for seven days. Activity of hepatic peroxisomal beta-oxidation and catalase decreased 58% and 74%, respectively, in glucose-infused rats compared with galactose- or saline-infused animals. When infused simultaneously with glucose, diazoxide blocked glucose-enhanced insulin secretion and prevented the decrease in peroxisomal enzyme activities, without altering blood glucose concentration. Neither diazoxide alone nor galactose, which did not alter serum insulin levels, had any effect on enzyme activities. These results suggest that hyperinsulinemia is responsible for the decreased enzyme activities observed in glucose-infused rats. Indeed, a strong negative correlation between serum insulin levels and hepatic peroxisomal enzyme activities was found. To investigate the mechanism by which insulin modulates catalase activity, we studied rates of synthesis and degradation of catalase in saline- and glucose-infused rats. Data show that insulin diminishes rates of catalase synthesis, while exhibiting no effect on its degradation. Upsetting the balance between the cellular capacity to produce and eliminate H2O2 may be a contributing

  11. Hydrogen peroxide-independent production of α-alkenes by OleTJE P450 fatty acid decarboxylase

    PubMed Central

    2014-01-01

    Background Cytochrome P450 OleTJE from Jeotgalicoccus sp. ATCC 8456, a new member of the CYP152 peroxygenase family, was recently found to catalyze the unusual decarboxylation of long-chain fatty acids to form α-alkenes using H2O2 as the sole electron and oxygen donor. Because aliphatic α-alkenes are important chemicals that can be used as biofuels to replace fossil fuels, or for making lubricants, polymers and detergents, studies on OleTJE fatty acid decarboxylase are significant and may lead to commercial production of biogenic α-alkenes in the future, which are renewable and more environmentally friendly than petroleum-derived equivalents. Results We report the H2O2-independent activity of OleTJE for the first time. In the presence of NADPH and O2, this P450 enzyme efficiently decarboxylates long-chain fatty acids (C12 to C20) in vitro when partnering with either the fused P450 reductase domain RhFRED from Rhodococcus sp. or the separate flavodoxin/flavodoxin reductase from Escherichia coli. In vivo, expression of OleTJE or OleTJE-RhFRED in different E. coli strains overproducing free fatty acids resulted in production of variant levels of multiple α-alkenes, with a highest total hydrocarbon titer of 97.6 mg·l-1. Conclusions The discovery of the H2O2-independent activity of OleTJE not only raises a number of fundamental questions on the monooxygenase-like mechanism of this peroxygenase, but also will direct the future metabolic engineering work toward improvement of O2/redox partner(s)/NADPH for overproduction of α-alkenes by OleTJE. PMID:24565055

  12. Lung cancer biomarkers for the assessment of modified risk tobacco products: an oxidative stress perspective.

    PubMed

    Lowe, Frazer J; Luettich, Karsta; Gregg, Evan O

    2013-05-01

    Manufacturers have developed prototype cigarettes yielding reduced levels of some tobacco smoke toxicants, when tested using laboratory machine smoking under standardised conditions. For the scientific assessment of modified risk tobacco products, tests that offer objective, reproducible data, which can be obtained in a much shorter time than the requirements of conventional epidemiology are needed. In this review, we consider whether biomarkers of biological effect related to oxidative stress can be used in this role. Based on published data, urinary 8-oxo-7,8-dihydro-2-deoxyguanosine, thymidine glycol, F2-isoprostanes, serum dehydroascorbic acid to ascorbic acid ratio and carotenoid concentrations show promise, while 4-hydroxynonenal requires further qualification.

  13. Lung cancer biomarkers for the assessment of modified risk tobacco products: an oxidative stress perspective

    PubMed Central

    Luettich, Karsta; Gregg, Evan O.

    2013-01-01

    Manufacturers have developed prototype cigarettes yielding reduced levels of some tobacco smoke toxicants, when tested using laboratory machine smoking under standardised conditions. For the scientific assessment of modified risk tobacco products, tests that offer objective, reproducible data, which can be obtained in a much shorter time than the requirements of conventional epidemiology are needed. In this review, we consider whether biomarkers of biological effect related to oxidative stress can be used in this role. Based on published data, urinary 8-oxo-7,8-dihydro-2-deoxyguanosine, thymidine glycol, F2-isoprostanes, serum dehydroascorbic acid to ascorbic acid ratio and carotenoid concentrations show promise, while 4-hydroxynonenal requires further qualification. PMID:23530763

  14. Aerobic exercise training protects against endothelial dysfunction by increasing nitric oxide and hydrogen peroxide production in LDL receptor-deficient mice.

    PubMed

    Guizoni, Daniele M; Dorighello, Gabriel G; Oliveira, Helena C F; Delbin, Maria A; Krieger, Marta H; Davel, Ana P

    2016-07-19

    Endothelial dysfunction associated with hypercholesterolemia is an early event in atherosclerosis characterized by redox imbalance associated with high superoxide production and reduced nitric oxide (NO) and hydrogen peroxide (H2O2) production. Aerobic exercise training (AET) has been demonstrated to ameliorate atherosclerotic lesions and oxidative stress in advanced atherosclerosis. However, whether AET protects against the early mechanisms of endothelial dysfunction in familial hypercholesterolemia remains unclear. This study investigated the effects of AET on endothelial dysfunction and vascular redox status in the aortas of LDL receptor knockout mice (LDLr(-/-)), a genetic model of familial hypercholesterolemia. Twelve-week-old C57BL/6J (WT) and LDLr(-/-) mice were divided into sedentary and exercised (AET on a treadmill 1 h/5 × per week) groups for 4 weeks. Changes in lipid profiles, endothelial function, and aortic NO, H2O2 and superoxide production were examined. Total cholesterol and triglycerides were increased in sedentary and exercised LDLr(-/-) mice. Endothelium-dependent relaxation induced by acetylcholine was impaired in aortas of sedentary LDLr(-/-) mice but not in the exercised group. Inhibition of NO synthase (NOS) activity or H2O2 decomposition by catalase abolished the differences in the acetylcholine response between the animals. No changes were noted in the relaxation response induced by NO donor sodium nitroprusside or H2O2. Neuronal NOS expression and endothelial NOS phosphorylation (Ser1177), as well as NO and H2O2 production, were reduced in aortas of sedentary LDLr(-/-) mice and restored by AET. Incubation with apocynin increased acetylcholine-induced relaxation in sedentary, but not exercised LDLr(-/-) mice, suggesting a minor participation of NADPH oxidase in the endothelium-dependent relaxation after AET. Consistent with these findings, Nox2 expression and superoxide production were reduced in the aortas of exercised compared to

  15. 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.

  16. Ascorbic acid pre-treated quartz stimulates TNF-α release in RAW 264.7 murine macrophages through ROS production and membrane lipid peroxidation

    PubMed Central

    Scarfì, Sonia; Magnone, Mirko; Ferraris, Chiara; Pozzolini, Marina; Benvenuto, Federica; Benatti, Umberto; Giovine, Marco

    2009-01-01

    Background Inhalation of crystalline silica induces a pulmonary fibrotic degeneration called silicosis caused by the inability of alveolar macrophages to dissolve the crystalline structure of phagocytosed quartz particles. Ascorbic acid is capable of partially dissolving quartz crystals, leading to an increase of soluble silica concentration and to the generation of new radical sites on the quartz surface. The reaction is specific for the crystalline forms of silica. It has been already demonstrated an increased cytotoxicity and stronger induction of pro-inflammatory cyclooxygenase-2 (COX-2) by ascorbic acid pre-treated quartz (QA) compared to untreated quartz (Q) in the murine macrophage cell line RAW 264.7. Methods Taking advantage of the enhanced macrophage response to QA as compared to Q particles, we investigated the first steps of cell activation and the contribution of early signals generated directly from the plasma membrane to the production of TNF-α, a cytokine that activates both inflammatory and fibrogenic pathways. Results Here we demonstrate that TNF-α mRNA synthesis and protein secretion are significantly increased in RAW 264.7 macrophages challenged with QA as compared to Q particles, and that the enhanced response is due to an increase of intracellular ROS. Plasma membrane-particle contact, in the absence of phagocytosis, is sufficient to trigger TNF-α production through a mechanism involving membrane lipid peroxidation and this appears to be even more detrimental to macrophage survival than particle phagocytosis itself. Conclusion Taken together these data suggest that an impairment of pulmonary macrophage phagocytosis, i.e. in the case of alcoholic subjects, could potentiate lung disease in silica-exposed individuals. PMID:19298665

  17. Ultrasonically Induced Degradation of Microcystin-LR and -RR: Identification of Products, Effect of pH, Formation and Destruction of Peroxides

    PubMed Central

    SONG, WEIHUA; DE LA CRUZ, ARMAH A.; REIN, KATHLEEN; O'SHEA, KEVIN E.

    2008-01-01

    Microcystins (MCs) are a family of toxic peptides produced by a number of cyanobacteria commonly found in lakes, water reservoirs, and recreational facilities. The increased eutrophication of freshwater supplies has led to an increase in the incidence of cyanobacterial harmful algal blooms and concerns over the public health implications of these toxins in the water supply. Conventional water treatment methods are ineffective at removing low concentrations of cyanotoxins, hence specialized treatment is usually recommended for treatment of contaminated water. In this study, the products of ultrasonically induced degradation of microcystin-LR (MC-LR) and microcystin-RR (MC-RR) were analyzed by LC–MS to elucidate the probable pathways of degradation of these toxins. Results indicate preliminary products of sonolysis of MCs are due to the hydroxyl radical attack on the benzene ring and diene of the Adda peptide residue and cleavage of the Mdha–Ala peptide bond. The effect of pH on the toxin degradation was evaluated since the pH of the solution changes upon ultrasonic irradiation and varies with the water quality of treatable waters. The initial rate of MC-LR degradation is greater at acidic pH and coincides with the change in hydrophobic character of MC-LR as a function of pH. Hydrogen and organic peroxides are formed during ultrasonic irradiation, but can be eliminated by adding Fe(II). The addition of Fe(II) also accelerates the degradation of MC-LR, presumably by promoting the formation of hydroxyl radicals via conversion of ultrasonically produced H2O2. These findings suggest that sonolysis can effectively degrade MCs in drinking water. PMID:16830565

  18. 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.

  19. Distribution of Gaseous and Particulate Organic Peroxides Formed in the Ozonolysis of α-Pinene

    NASA Astrophysics Data System (ADS)

    Li, H.; Chen, Z.; Huang, L.; Huang, D.

    2015-12-01

    Organic peroxides, an important species in the atmosphere, will affect HOx cycling, promote SOA aging, and cause adverse health effect. However, the formation, distribution and evolution of organic peroxides are extremely complicated and still unclear. In this study, we investigate in laboratory the production of peroxides and gas-particle partitioning in the ozonolysis of α-pinene. The molar yields of hydrogen peroxide (H2O2), hydromethyl hydroperoxide (HMHP), performic acid (PFA), peracetic acid (PAA) and total peroxides (TPO, including unknown peroxides) and contribution of peroxides to SOA mass are carefully determined. Comparing the gaseous and particulate peroxides, we find that more than 75% peroxides formed in the ozonolysis remain in the gas phase, and water vapour will significantly influence the formation and distribution of peroxides. Such an unexpected large amount of gaseous peroxides deserves more attention, especially to their effect on HOx cycling.

  20. Antimalarial Cyclic Peroxide Lactones.

    DTIC Science & Technology

    1987-05-31

    AD-019? 365 RNTINRLARIAL CYCLIC PEROXIDE LACTONES (U) NORTH CROLINA 1’ UWIY AT CHAPEL HILL SCHOOL OF PHARMACY K LEE 31 MAY S? 0 AND 7-82-C-3096...CYCLIC PEROXIDE LACTONES FINAL REPORT I KUO-HSIUNG LEE SELEC-1 NOiV 25 87 May 31, 1987 Supported by U. S. ARMY MEDICAL RESEARCH AND DEVELOPMENT COMMAND...Security Classification) (U) Antimalarial Cyclic Peroxide Lactones 12. PERSONAL AUTHOR(S) Kuo-Hsiung Lee 13a. TYPE OF REPORT 13b. TIME COVERED 14

  1. The relationship between plasma lipid peroxidation products and primary graft dysfunction after lung transplantation is modified by donor smoking and reperfusion hyperoxia

    PubMed Central

    Diamond, Joshua M.; Porteous, Mary K.; Roberts, L. Jackson; Wickersham, Nancy; Rushefski, Melanie; Kawut, Steven M.; Shah, Rupal J.; Cantu, Edward; Lederer, David J.; Chatterjee, Shampa; Lama, Vibha N.; Bhorade, Sangeeta; Crespo, Maria; McDyer, John; Wille, Keith; Orens, Jonathan; Weinacker, Ann; Arcasoy, Selim; Shah, Pali D.; Wilkes, David S.; Hage, Chadi; Palmer, Scott M.; Snyder, Laurie; Calfee, Carolyn S.

    2016-01-01

    Purpose Donor smoking history and higher FiO2 at reperfusion are associated with primary graft dysfunction (PGD) after lung transplantation. We hypothesized that oxidative injury biomarkers would be elevated in PGD, with higher levels associated with donor exposure to cigarette smoke and recipient hyperoxia at reperfusion. Methods We performed a nested case control study of 72 lung transplant recipients from the Lung Transplant Outcomes Group cohort. F2-isoprostanes and isofurans were measured by mass spectroscopy in plasma collected after transplantation. Cases were defined in two ways: grade 3 PGD present at day 2 or day 3 after reperfusion (severe PGD), or any grade 3 PGD (any PGD). Results There were 31 severe PGD cases with 41 controls and 35 any PGD cases with 37 controls. Plasma F2-isoprostane levels were higher in severe PGD compared to controls (28.6 pg/ml vs. 19.8 pg/ml, p=0.03). Plasma F2-isoprostane levels were higher in severe PGD compared to controls (29.6 pg/ml vs. 19.0 pg/ml, p=0.03) among patients reperfused with FiO2>40%. Among recipients of lungs from donors with smoke exposure, plasma F2-isoprostane (38.2 pg/ml vs. 22.5 pg/ml, p=0.046) and isofuran (66.9 pg/ml vs. 34.6 pg/ml, p=0.046) levels were higher in severe PGD compared with controls. Conclusions Plasma levels of lipid peroxidation products are higher in patients with severe PGD, in recipients of lungs from donors with smoke exposure, and recipients exposed to higher FiO2 at reperfusion. Oxidative injury is an important mechanism of PGD and may be magnified by donor exposure to cigarette smoke and hyperoxia at reperfusion. PMID:26856667

  2. Cockayne syndrome group B protein is engaged in processing of DNA adducts of lipid peroxidation product trans-4-hydroxy-2-nonenal

    PubMed Central

    Maddukuri, Leena; Speina, Elżbieta; Christiansen, Mette; Dudzińska, Dominika; Zaim, Jolanta; Obtułowicz, Tomasz; Kabaczyk, Sylwia; Komisarski, Marek; Bukowy, Zuzanna; Szczegielniak, Jadwiga; Wójcik, Andrzej; Kuśmierek, Jaroslaw T.; Stevnsner, Tinna; Bohr, Vilhelm A.; Tudek, Barbara

    2015-01-01

    Cockayne syndrome complementation group B (CSB) protein is engaged in transcription-coupled repair (TCR) of UV induced DNA damage and its deficiency leads to progressive multisystem degeneration and premature aging. Here, we show that human CSB-deficient cells are hypersensitive to physiological concentrations (1–10 µM) of a lipid peroxidation product, trans-4-hydroxy-2-nonenal (HNE), and in response to HNE they develop a higher level of sister chromatid exchanges (SCEs) in comparison to the wild-type cells. HNE-DNA adducts block in vitro transcription by T7 RNA polymerase, as well as by HeLa cell-free extracts. Treatment of wild-type cells with 1–20 µM HNE causes dephosphorylation of the CSB protein, which stimulates its ATPase activity necessary for TCR. However, high HNE concentrations (100–200 µM) inhibit in vitro CSB ATPase activity as well as the transcription machinery in HeLa cell-free extracts. Cell lines expressing CSB protein mutated in different ATPase domains exhibit different sensitivities to HNE. The motif II mutant, which binds ATP, but is defective in ATP hydrolysis was as sensitive to HNE as CSB-null cells. In contrast, motif V mutant cells were as sensitive to HNE as were the cells bearing wild-type protein, while motif VI mutant cells showed intermediate sensitivity to HNE. These mutants exhibit decreased ATP binding, but retain residual ATPase activity. Homology modeling suggested that amino acids mutated in motifs II and VI are localized closer to the ATP binding site than amino acids mutated in ATPase motif V. These results suggest that HNE-DNA adducts are extremely toxic endogenous DNA lesion, and that their processing involves CSB. When these lesions are not removed from the transcribed DNA strand due to CSB gene mutation or CSB protein inactivation by high, pathological HNE concentrations, they may contribute to accelerated aging. PMID:19481676

  3. Intraneuronal Amylin Deposition, Peroxidative Membrane Injury and Increased IL-1β Synthesis in Brains of Alzheimer's Disease Patients with Type-2 Diabetes and in Diabetic HIP Rats.

    PubMed

    Verma, Nirmal; Ly, Han; Liu, Miao; Chen, Jing; Zhu, Haining; Chow, Martin; Hersh, Louis B; Despa, Florin

    2016-05-05

    Amylin is a hormone synthesized and co-secreted with insulin by pancreatic β-cells that crosses the blood-brain barrier and regulates satiety. Amylin from humans (but not rodents) has an increased propensity to aggregate into pancreatic islet amyloid deposits that contribute to β-cell mass depletion and development of type-2 diabetes by inducing oxidative stress and inflammation. Recent studies demonstrated that aggregated amylin also accumulates in brains of Alzheimer's disease (AD) patients, preponderantly those with type-2 diabetes. Here, we report that, in addition to amylin plaques and mixed amylin-Aβ deposits, brains of diabetic patients with AD show amylin immunoreactive deposits inside the neurons. Neuronal amylin formed adducts with 4-hydroxynonenal (4-HNE), a marker of peroxidative membrane injury, and increased synthesis of the proinflammatory cytokine interleukin (IL)-1β. These pathological changes were mirrored in rats expressing human amylin in pancreatic islets (HIP rats) and mice intravenously injected with aggregated human amylin, but not in hyperglycemic rats secreting wild-type non-amyloidogenic rat amylin. In cultured primary hippocampal rat neurons, aggregated amylin increased IL-1β synthesis via membrane destabilization and subsequent generation of 4-HNE. These effects were blocked by membrane stabilizers and lipid peroxidation inhibitors. Thus, elevated circulating levels of aggregated amylin negatively affect the neurons causing peroxidative membrane injury and aberrant inflammatory responses independent of other confounding factors of diabetes. The present results are consistent with the pathological role of aggregated amylin in the pancreas, demonstrate a novel contributing mechanism to neurodegeneration, and suggest a direct, potentially treatable link of type-2 diabetes with AD.

  4. Hydrogen peroxide inhibition of bicupin oxalate oxidase

    PubMed Central

    Goodwin, John M.; Rana, Hassan; Ndungu, Joan; Chakrabarti, Gaurab

    2017-01-01

    Oxalate oxidase is a manganese containing enzyme that catalyzes the oxidation of oxalate to carbon dioxide in a reaction that is coupled with the reduction of oxygen to hydrogen peroxide. Oxalate oxidase from Ceriporiopsis subvermispora (CsOxOx) is the first fungal and bicupin enzyme identified that catalyzes this reaction. Potential applications of oxalate oxidase for use in pancreatic cancer treatment, to prevent scaling in paper pulping, and in biofuel cells have highlighted the need to understand the extent of the hydrogen peroxide inhibition of the CsOxOx catalyzed oxidation of oxalate. We apply a membrane inlet mass spectrometry (MIMS) assay to directly measure initial rates of carbon dioxide formation and oxygen consumption in the presence and absence of hydrogen peroxide. This work demonstrates that hydrogen peroxide is both a reversible noncompetitive inhibitor of the CsOxOx catalyzed oxidation of oxalate and an irreversible inactivator. The build-up of the turnover-generated hydrogen peroxide product leads to the inactivation of the enzyme. The introduction of catalase to reaction mixtures protects the enzyme from inactivation allowing reactions to proceed to completion. Circular dichroism spectra indicate that no changes in global protein structure take place in the presence of hydrogen peroxide. Additionally, we show that the CsOxOx catalyzed reaction with the three carbon substrate mesoxalate consumes oxygen which is in contrast to previous proposals that it catalyzed a non-oxidative decarboxylation with this substrate. PMID:28486485

  5. Hydrogen peroxide inhibition of bicupin oxalate oxidase.

    PubMed

    Goodwin, John M; Rana, Hassan; Ndungu, Joan; Chakrabarti, Gaurab; Moomaw, Ellen W

    2017-01-01

    Oxalate oxidase is a manganese containing enzyme that catalyzes the oxidation of oxalate to carbon dioxide in a reaction that is coupled with the reduction of oxygen to hydrogen peroxide. Oxalate oxidase from Ceriporiopsis subvermispora (CsOxOx) is the first fungal and bicupin enzyme identified that catalyzes this reaction. Potential applications of oxalate oxidase for use in pancreatic cancer treatment, to prevent scaling in paper pulping, and in biofuel cells have highlighted the need to understand the extent of the hydrogen peroxide inhibition of the CsOxOx catalyzed oxidation of oxalate. We apply a membrane inlet mass spectrometry (MIMS) assay to directly measure initial rates of carbon dioxide formation and oxygen consumption in the presence and absence of hydrogen peroxide. This work demonstrates that hydrogen peroxide is both a reversible noncompetitive inhibitor of the CsOxOx catalyzed oxidation of oxalate and an irreversible inactivator. The build-up of the turnover-generated hydrogen peroxide product leads to the inactivation of the enzyme. The introduction of catalase to reaction mixtures protects the enzyme from inactivation allowing reactions to proceed to completion. Circular dichroism spectra indicate that no changes in global protein structure take place in the presence of hydrogen peroxide. Additionally, we show that the CsOxOx catalyzed reaction with the three carbon substrate mesoxalate consumes oxygen which is in contrast to previous proposals that it catalyzed a non-oxidative decarboxylation with this substrate.

  6. 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.

  7. Structural diversity and chemical synthesis of peroxide and peroxide-derived polyketide metabolites from marine sponges.

    PubMed

    Norris, Matthew D; Perkins, Michael V

    2016-07-28

    Covering: up to early 2016Marine sponges are widely known as a rich source of natural products, especially of polyketide origin, with a wealth of chemical diversity. Within this vast collection, peroxide and peroxide-derived secondary metabolites have attracted significant interest in the fields of natural product isolation and chemical synthesis for their structural distinction and promising in vitro antimicrobial and anticancer properties. In this review, peroxide and peroxide-derived polyketide metabolites isolated from marine sponges in the past 35 years are summarised. Efforts toward their synthesis are detailed with a focus on methods that utilise or attempt to elucidate the complex biosynthetic interrelationships of these compounds beyond enzymatic polyketide synthesis. Recent isolations, advances in synthetic methodology and theories of biogenesis are highlighted and critically evaluated.

  8. Effect of cinnamon (Cinnamomum zeylanicum) bark oil on heat stress-induced changes in sperm production, testicular lipid peroxidation, testicular apoptosis, and androgenic receptor density in developing Japanese quails.

    PubMed

    Türk, Gaffari; Şimşek, Ülkü G; Çeribaşı, Ali O; Çeribaşı, Songül; Özer Kaya, Şeyma; Güvenç, Mehmet; Çiftçi, Mehmet; Sönmez, Mustafa; Yüce, Abdurrauf; Bayrakdar, Ali; Yaman, Mine; Tonbak, Fadime

    2015-08-01

    The aim of this study was to investigate the effect of cinnamon bark oil (CBO) on heat stress (HS)-induced changes in sperm production, testicular lipid peroxidation, testicular apoptosis, and androgenic receptor (AR) density in developing Japanese quails. Fifteen-day-old 90 male chicks were assigned to two main groups. The first group (45 chicks) was kept in a thermoneutral room at 22 °C for 24 h/day. The second group (45 chicks) was kept in a room with high ambient temperature at 34 °C for 8 h/day (from 9 AM-5 PM) and at 22 °C for 16 h/day. Each of these two main groups was then divided into three subgroups (CBO groups 0, 250, 500 ppm) consisting of 15 chicks (six treatment groups in 2 × 3 factorial order). Each of subgroups was replicated for three times and each replicate included five chicks. Heat stress caused significant decreases in body weight, spermatid and testicular sperm numbers, the density of testicular Bcl-2 (antiapoptotic marker) and AR immunopositivity, and significant increases in testicular lipid peroxidation level, the density of testicular Bax (apoptotic marker) immunopositivity, and a Bax/Bcl-2 ratio along with some histopathologic damages. However, 250 and 500 ppm CBO supplementation provided significant improvements in HS-induced increased level of testicular lipid peroxidation, decreased number of spermatid and testicular sperm, decreased densities of Bcl-2 and AR immunopositivity, and some deteriorated testicular histopathologic lesions. In addition, although HS did not significantly affect the testicular glutathione level, addition of both 250 and 500 ppm CBO to diet of quails reared in both HS and thermoneutral conditions caused a significant increase when compared with quails without any consumption of CBO. In conclusion, HS-induced lipid peroxidation causes testicular damage in developing male Japanese quails and, consumption of CBO, which has antiperoxidative effect, protects their testes against HS. Copyright © 2015 Elsevier

  9. The Peroxide Pathway

    NASA Technical Reports Server (NTRS)

    McNeal, Curtis I., Jr.; Anderson, William

    1999-01-01

    NASA's current focus on technology roadmaps as a tool for guiding investment decisions leads naturally to a discussion of NASA's roadmap for peroxide propulsion system development. NASA's new Second Generation Space Transportation System roadmap calls for an integrated Reusable Upper-Stage (RUS) engine technology demonstration in the FY03/FY04 time period. Preceding this integrated demonstration are several years of component developments and subsystem technology demonstrations. NASA and the Air Force took the first steps at developing focused upper stage technologies with the initiation of the Upper Stage Flight Experiment with Orbital Sciences in December 1997. A review of this program's peroxide propulsion development is a useful first step in establishing the peroxide propulsion pathway that could lead to a RUS demonstration in 2004.

  10. 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.

  11. Development of a thermally self-sustaining kWe-class diesel reformer using hydrogen peroxide for hydrogen production in low-oxygen environments

    NASA Astrophysics Data System (ADS)

    Han, Gwangwoo; Lee, Kwangho; Ha, Sanghyeon; Bae, Joongmyeon

    2016-09-01

    A novel technology of a diesel reformer that uses hydrogen peroxide is developed to obtain the hydrogen required for fuel cell air-independent propulsion for underwater applications, such as submarines and unmanned underwater vehicles. Diesel fuel could be a promising hydrogen source for underwater applications due to its high hydrogen density and its globally well-equipped infrastructure. An alternative oxidant, hydrogen peroxide (H2O2), is applied to supply not only oxygen but also the water required for diesel autothermal (ATR) reforming. The proposed reformer does not require an additional heating device to supply heat for the vaporization of diesel or oxidant due to the exothermic nature of the ATR reaction and the heat of decomposition of H2O2. The effects of H2O2 on diesel reforming were confirmed based on operating the engineering-scale (kWe-class) diesel-H2O2 reformer. Undecomposed H2O2 caused an excessively high temperature in the mixing zone and a corrosion effect in the reformer wall. To overcome these phenomena, we introduced a catalytic H2O2 decomposer to fully decompose hydrogen peroxide into steam and oxygen. From this important step, we essentially eliminate side effects from undecomposed H2O2 and retain a high reforming efficiency by utilizing the heat of decomposition of H2O2.

  12. Production of stabilized Criegee intermediates and peroxides in the gas phase ozonolysis of alkenes: 1. Ethene, trans-2-butene, and 2,3-dimethyl-2-butene

    NASA Astrophysics Data System (ADS)

    Hasson, Alam S.; Orzechowska, Grazyna; Paulson, Suzanne E.

    2001-12-01

    Ozone-alkene reactions generate stabilized Criegee intermediates (of the form R1R2COO), which are believed to react with water molecules to form organic hydroperoxides, hydrogen peroxide and carboxylic acids. These reactions are thought to be significant sources of these environmentally important compounds, yet both the yields of stabilized Criegee intermediates and the branching ratios from their reaction with water are not well known. The formation of hydrogen peroxide and organic hydroperoxides was investigated in the gas phase ozonolysis of ethene, trans-2-butene, and 2,3-dimethyl-2-butene for relative humidities (RH) from 0 and 80% by gas chromatography with flame ionization detection and high-performance liquid chromatography with fluorescence detection. Additionally, yields of acetaldehyde and acetic acid from trans-2-butene and acetone from 2,3-dimethyl-2-butene were measured. The reactions of stabilized Criegee intermediates with water were found to proceed almost entirely via organic hydroperoxide or hydrogen peroxide formation with little acid formation. Stabilized Criegee intermediate yields of 0.39, 0.24, and 0.10 were obtained for ethene, trans-2-butene, and 2,3-dimethyl-2-butene, respectively.

  13. Determination of peroxides in saliva--kinetics of peroxide release into saliva during home-bleaching with Whitestrips and Vivastyle.

    PubMed

    Hannig, Christian; Zech, Ronald; Henze, Elvira; Dorr-Tolui, Reza; Attin, Thomas

    2003-08-01

    Aim of the study was to determine peroxides in saliva, released during bleaching procedures. Upper incisors of five subjects were bleached with Whitestrips (5% H2O2) and Vivastyle (10% carbamide peroxide, tray charged with 225mg) for 30min, each on different days. Saliva was collected before and during the whole period of bleaching at different intervals. The amount of peroxide in the salivary samples was assessed with peroxidase, phenol and 4-aminoantipyrin in a photometric assay. Additionally the amount of peroxides in the bleaching material was determined before and after the bleaching, so that the peroxide release into saliva could be balanced. The amount of peroxides released into saliva was related to the bleaching system and only partially influenced by the individual salivary flow rate. Bleaching with Vivastyle led to lower release of peroxides into saliva compared to Whitestrips (Vivastyle: 0.8+/-0.17mg; Whitestrips: 1.5+/-0.84mg). Salivary flow rate was not correlated to release of peroxides from the bleaching products. It can be concluded that the enzymatic method adopting 4-aminoantipyrin and peroxidase is valid for the determination of peroxides in saliva. Furthermore distinctly more peroxides are released into the oral cavity from Whitestrips than from trays charged with Vivastyle .

  14. Clindamycin and Benzoyl Peroxide Topical

    MedlinePlus

    The combination of clindamycin and benzoyl peroxide is used to treat acne. Clindamycin and benzoyl peroxide are in a class of medications called topical antibiotics. The combination of clindamycin ...

  15. 21 CFR 184.1157 - Benzoyl peroxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...; milk used for production of Asiago fresh and Asiago soft cheese (§ 133.102), Asiago medium cheese... chloride, sodium hydroxide, and hydrogen peroxide. (b) The ingredient meets the specifications of the Food... material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal...

  16. Phytic Acid Inhibits Lipid Peroxidation In Vitro

    PubMed Central

    Węglarz, Ludmiła; Dzierżewicz, Zofia

    2013-01-01

    Phytic acid (PA) has been recognized as a potent antioxidant and inhibitor of iron-catalyzed hydroxyl radical formation under in vitro and in vivo conditions. Therefore, the aim of the present study was to investigate, with the use of HPLC/MS/MS, whether PA is capable of inhibiting linoleic acid autoxidation and Fe(II)/ascorbate-induced peroxidation, as well as Fe(II)/ascorbate-induced lipid peroxidation in human colonic epithelial cells. PA at 100 μM and 500 μM effectively inhibited the decay of linoleic acid, both in the absence and presence of Fe(II)/ascorbate. The observed inhibitory effect of PA on Fe(II)/ascorbate-induced lipid peroxidation was lower (10–20%) compared to that of autoxidation. PA did not change linoleic acid hydroperoxides concentration levels after 24 hours of Fe(II)/ascorbate-induced peroxidation. In the absence of Fe(II)/ascorbate, PA at 100 μM and 500 μM significantly suppressed decomposition of linoleic acid hydroperoxides. Moreover, PA at the tested nontoxic concentrations (100 μM and 500 μM) significantly decreased 4-hydroxyalkenal levels in Caco-2 cells which structurally and functionally resemble the small intestinal epithelium. It is concluded that PA inhibits linoleic acid oxidation and reduces the formation of 4-hydroxyalkenals. Acting as an antioxidant it may help to prevent intestinal diseases induced by oxygen radicals and lipid peroxidation products. PMID:24260736

  17. Inhibition of Mitochondrial Complex I Leads to Decreased Motility and Membrane Integrity Related to Increased Hydrogen Peroxide and Reduced ATP Production, while the Inhibition of Glycolysis Has Less Impact on Sperm Motility

    PubMed Central

    Plaza Davila, María; Martin Muñoz, Patricia; Tapia, Jose A.; Ortega Ferrusola, Cristina; Balao da Silva C, Carolina; Peña, Fernando J.

    2015-01-01

    Mitochondria have been proposed as the major source of reactive oxygen species in somatic cells and human spermatozoa. However, no data regarding the role of mitochondrial ROS production in stallion spermatozoa are available. To shed light on the role of the mitochondrial electron transport chain in the origin of oxidative stress in stallion spermatozoa, specific inhibitors of complex I (rotenone) and III (antimycin-A) were used. Ejaculates from seven Andalusian stallions were collected and incubated in BWW media at 37°C in the presence of rotenone, antimycin-A or control vehicle. Incubation in the presence of these inhibitors reduced sperm motility and velocity (CASA analysis) (p<0.01), but the effect was more evident in the presence of rotenone (a complex I inhibitor). These inhibitors also decreased ATP content. The inhibition of complexes I and III decreased the production of reactive oxygen species (p<0.01) as assessed by flow cytometry after staining with CellRox deep red. This observation suggests that the CellRox probe mainly identifies superoxide and that superoxide production may reflect intense mitochondrial activity rather than oxidative stress. The inhibition of complex I resulted in increased hydrogen peroxide production (p<0.01). The inhibition of glycolysis resulted in reduced sperm velocities (p<0.01) without an effect on the percentage of total motile sperm. Weak and moderate (but statistically significant) positive correlations were observed between sperm motility, velocity and membrane integrity and the production of reactive oxygen species. These results indicate that stallion sperm rely heavily on oxidative phosphorylation (OXPHOS) for the production of ATP for motility but also require glycolysis to maintain high velocities. These data also indicate that increased hydrogen peroxide originating in the mitochondria is a mechanism involved in stallion sperm senescence. PMID:26407142

  18. Oxidation of white phosphorus by peroxides in water

    NASA Astrophysics Data System (ADS)

    Abdreimova, R. R.; Akbaeva, D. N.; Polimbetova, G. S.

    2017-10-01

    A mixture of hypophosphorous, phosphorous, and phosphoric acids is formed during the anaerobic oxidation of white phosphorus by peroxides [ROOH; R = H, 3-ClC6H4CO, (CH3)3C] in water. The rate of reactions grows considerably upon adding nonpolar organic solvents. The activity series of peroxides and solvents are determined experimentally. NMR spectroscopy shows that the main product of the reaction is phosphorous acid, regardless of the nature of the peroxide and solvent. A radical mechanism of oxidation of white phosphorus by peroxides in water is proposed. It is initiated by the homolysis of peroxide with the formation of HO• radicals that are responsible for the homolytic opening of phosphoric tetrahedrons. Further oxidation and stages of the hydrolysis of intermediate phosphorus-containing compounds yield products of the reaction.

  19. [Changes of fatty-acid structure of common lipids and contents of peroxidation products in tissues of embryos depending on the level of vitamins A, D3 and E in a diet of geese during the reproductive period].

    PubMed

    Moravs'ka, O V; Vovk, S O

    2010-01-01

    Results concerning the contents of retinol in the liver, residual yoke of 25-day embryos and yoke of eggs depending on the level of vitamins A, D3 and E in the diet of geese by grey Obroshin breeds in reproductive period are presented in the paper. It is established, that vitamin D3 reduces the level of retinol deposition in the tissues of embryos and yoke of eggs of geese, and addition of vitamins A and E to a diet of geese raises the level of retinol both in the liver and residual yoke of embryos, and in yokes of geese eggs. Besides the data about changes of fatty-acid spectrum of common lipids and contents of lipid peroxidations products in tissues of the liver and pectoral muscles of 25-day embryos are presented in the paper depending on the level of vitamins A, D3 and E in geese diet during their reproductive period. Introduction of vitamin A--in quantity of 10000 IU, vitamin D3--in quantity of 3000 IU, in the composition of mixed fodder of geese during the reproductive period and vitamin E in quantity 35 IU on 1 kg to mixed fodder optimizes fatty-acid structure of the common lipids and the level of peroxidations lipids products in the liver and pectoral muscles of embryos.

  20. Algal toxicity of the alternative disinfectants performic acid (PFA), peracetic acid (PAA), chlorine dioxide (ClO2) and their by-products hydrogen peroxide (H2O2) and chlorite (ClO2-).

    PubMed

    Chhetri, Ravi Kumar; Baun, Anders; Andersen, Henrik Rasmus

    2017-05-01

    Environmental effect evaluation of disinfection of combined sewer overflow events with alternative chemical disinfectants requires that the environmental toxicity of the disinfectants and the main by-products of their use are known. Many disinfectants degrade quickly in water which should be included in the evaluation of both their toxicity as determined in standardized tests and their possible negative effect in the water environment. Here we evaluated according to the standardized ISO 8692 test the toxicity towards the green microalgae, Pseudokirchneriella subcapitata, of three disinfectants: performic acid (PFA), peracetic acid (PAA) and chlorine dioxide (ClO 2 ) as well as two by-products of their use: hydrogen peroxide (H 2 O 2 ) and chlorite. All of the five chemicals investigated showed clear toxicity to the algae with well-defined dose response curves. The EC 50 values ranged from 0.16 to 2.9mg/L based on nominal concentrations leading to the labeling of the chemicals as either toxic or very toxic. The five investigated chemicals decreased in toxicity in the order chlorine dioxide, performic acid, peracetic acid, chlorite and hydrogen peroxide. The stability of the chemicals increased in the same order as the toxicity decrease. This indicates that even though ClO 2 has the highest environmental hazard potential, it may still be suitable as an alternative disinfectant due to its rapid degradation in water. Copyright © 2016 Elsevier GmbH. All rights reserved.

  1. Lipid peroxidation in presence of ebselen.

    PubMed

    Batna, A; Fuchs, C; Spiteller, G

    1997-07-14

    Lipid peroxidation is initiated by cell damage. After homogenisation of porcine heart tissue in aqueous solution we observed the same lipid peroxidation products as detected after heart infarction. We used this observation to study the influence of ebselen (2-phenyl-1,2-benzoisoselenazol-3-(2H)-one) on the generation of oxidatively derived monohydroxy fatty acids and alpha-hydroxyaldehydes, typical lipid peroxidation (LPO) products. Heart tissue was homogenised before and after enzyme destruction and with addition of ebselen. The obtained LPO products were analysed by GC/MS after appropriate derivatisation and quantified by using internal standards. The amount of monohydroxy fatty acids and alpha-hydroxyaldehydes increased considerably in the porcine heart homogenates in which the enzymes were kept active. Addition of ebselen caused an additional significant increase of hydroxy fatty acids, while the increase of aldehydic compounds was less. These results confirm the glutathione peroxidase-like activity of ebselen but demonstrate also that it does not prevent lipid peroxidation.

  2. Efficacy, efficiency and safety aspects of hydrogen peroxide vapour and aerosolized hydrogen peroxide room disinfection systems.

    PubMed

    Fu, T Y; Gent, P; Kumar, V

    2012-03-01

    This was a head-to-head comparison of two hydrogen-peroxide-based room decontamination systems. To compare the efficacy, efficiency and safety of hydrogen peroxide vapour (HPV; Clarus R, Bioquell, Andover, U.K.) and aerosolized hydrogen peroxide (aHP; SR2, Sterinis, now supplied as Glosair, Advanced Sterilization Products (ASP), Johnson & Johnson Medical Ltd, Wokingham, U.K.) room disinfection systems. Efficacy was tested using 4- and 6-log Geobacillus stearothermophilus biological indicators (BIs) and in-house prepared test discs containing approximately 10(6) meticillin-resistant Staphylococcus aureus (MRSA), Clostridium difficile and Acinetobacter baumannii. Safety was assessed by detecting leakage of hydrogen peroxide using a hand-held detector. Efficiency was assessed by measuring the level of hydrogen peroxide using a hand-held sensor at three locations inside the room, 2 h after the start of the cycles. HPV generally achieved a 6-log reduction, whereas aHP generally achieved less than a 4-log reduction on the BIs and in-house prepared test discs. Uneven distribution was evident for the aHP system but not the HPV system. Hydrogen peroxide leakage during aHP cycles with the door unsealed, as per the manufacturer's operating manual, exceeded the short-term exposure limit (2 ppm) for more than 2 h. When the door was sealed with tape, as per the HPV system, hydrogen peroxide leakage was <1 ppm for both systems. The mean concentration of hydrogen peroxide in the room 2 h after the cycle started was 1.3 [standard deviation (SD) 0.4] ppm and 2.8 (SD 0.8) ppm for the four HPV and aHP cycles, respectively. None of the readings were <2 ppm for the aHP cycles. The HPV system was safer, faster and more effective for biological inactivation. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  3. Therapies Targeting Lipid Peroxidation in Traumatic Brain Injury

    PubMed Central

    Anthonymuthu, Tamil Selvan; Kenny, Elizabeth Megan; Bayır, Hülya

    2016-01-01

    Lipid peroxidation can be broadly defined as the process of inserting a hydroperoxy group into a lipid. Polyunsaturated fatty acids present in the phospholipids are often the targets for peroxidation. Phospholipids are indispensable for normal structure of membranes. The other important function of phospholipids stems from their role as a source of lipid mediators – oxygenated free fatty acids that are derived from lipid peroxidation. In the CNS, excessive accumulation of either oxidized phospholipids or oxygenated free fatty acids may be associated with damage occurring during acute brain injury and subsequent inflammatory responses. There is a growing body of evidence that lipid peroxidation occurs after severe traumatic brain injury in humans and correlates with the injury severity and mortality. Identification of the products and sources of lipid peroxidation and its enzymatic or non-enzymatic nature is essential for the design of mechanism-based therapies. Recent progress in mass spectrometry-based lipidomics/oxidative lipidomics offers remarkable opportunities for quantitative characterization of lipid peroxidation products, providing guidance for targeted development of specific therapeutic modalities. In this review, we critically evaluate previous attempts to use non-specific antioxidants as neuroprotectors and emphasize new approaches based on recent breakthroughs in understanding of enzymatic mechanisms of lipid peroxidation associated with specific death pathways, particularly apoptosis. We also emphasize the role of different phospholipases (calcium-dependent and -independent) in hydrolysis of peroxidized phospholipids and generation of pro- and anti-inflammatory lipid mediators. PMID:26872597

  4. 4-Hydroxy-2-Nonenal, a Reactive Product of Lipid Peroxidation, and Neurodegenerative Diseases: A Toxic Combination Illuminated by Redox Proteomics Studies

    PubMed Central

    Coccia, Raffaella; Butterfield, D. Allan

    2012-01-01

    Abstract Significance: Among different forms of oxidative stress, lipid peroxidation comprises the interaction of free radicals with polyunsaturated fatty acids, which in turn leads to the formation of highly reactive electrophilic aldehydes. Among these, the most abundant aldehydes are 4-hydroxy-2-nonenal (HNE) and malondialdehyde, while acrolein is the most reactive. HNE is considered a robust marker of oxidative stress and a toxic compound for several cell types. Proteins are particularly susceptible to modification caused by HNE, and adduct formation plays a critical role in multiple cellular processes. Recent Advances: With the outstanding progress of proteomics, the identification of putative biomarkers for neurodegenerative disorders has been the main focus of several studies and will continue to be a difficult task. Critical Issues: The present review focuses on the role of lipid peroxidation, particularly of HNE-induced protein modification, in neurodegenerative diseases. By comparing results obtained in different neurodegenerative diseases, it may be possible to identify both similarities and specific differences in addition to better characterize selective neurodegenerative phenomena associated with protein dysfunction. Results obtained in our laboratory and others support the common deregulation of energy metabolism and mitochondrial function in neurodegeneration. Future Directions: Research towards a better understanding of the molecular mechanisms involved in neurodegeneration together with identification of specific targets of oxidative damage is urgently required. Redox proteomics will contribute to broaden the knowledge in regard to potential biomarkers for disease diagnosis and may also provide insight into damaged metabolic networks and potential targets for modulation of disease progression. Antioxid. Redox Signal. 17, 1590–1609. PMID:22114878

  5. Pomegranate (Punicagranatum) juice decreases lipid peroxidation, but has no effect on plasma advanced glycated end-products in adults with type 2 diabetes: a randomized double-blind clinical trial

    PubMed Central

    Sohrab, Golbon; Angoorani, Pooneh; Tohidi, Maryam; Tabibi, Hadi; Kimiagar, Masoud; Nasrollahzadeh, Javad

    2015-01-01

    Introduction Diabetes mellitus characterized by hyperglycemia could increase oxidative stress and formation of advanced glycated end-products (AGEs), which contribute to diabetic complications. The purpose of this study was to assess the effect of pomegranate juice (PJ) containing natural antioxidant on lipid peroxidation and plasma AGEs in patients with type 2 diabetes (T2D). Materials and methods In a randomized, double-blind, placebo-controlled trial, 44 patients (age range 56±6.8 years), T2D were randomly assigned to one of two groups: group A (PJ, n=22) and group B (Placebo, n=22). At the baseline and the end of 12-week intervention, biochemical markers including fasting plasma glucose, insulin, oxidative stress, and AGE markers including carboxy methyl lysine (CML) and pentosidine were assayed. Results At baseline, there were no significant differences in plasma total antioxidant capacity (TAC) levels between the two groups, but malondialdehyde (MDA) decreased levels were significantly different (P<0.001). After 12 weeks of intervention, TAC increased (P<0.05) and MDA decreased (P<0.01) in the PJ group when compared with the placebo group. However, no significant differences were observed in plasma concentration of CML and pentosidine between the two groups. Conclusions The study showed that PJ decreases lipid peroxidation. Therefore, PJ consumption may delay onset of T2D complications related to oxidative stress. PMID:26355954

  6. The neuroprotective effect of heme oxygenase (HO) on oxidative stress in HO-1 siRNA-transfected HT22 cells.

    PubMed

    Kaizaki, Asuka; Tanaka, Sachiko; Ishige, Kumiko; Numazawa, Satoshi; Yoshida, Takemi

    2006-09-07

    To investigate the role of heme oxygenase (HO) isozymes, we used siRNA technology to suppress HO-1 expression. HO-1 siRNA-transfected HT22 cells were vulnerable to hydrogen peroxide- and 4-hydroxynonenal-induced cytotoxicity. Biliverdin and bilirubin, degradative products of heme catalyzed by HO, protected HT22 cells from the insult of these oxidative stressors. These results suggest that inducible HO-1 plays a protective role against oxidative stress in HT22 cells.

  7. Isoprene Produced by Leaves Protects the Photosynthetic Apparatus against Ozone Damage, Quenches Ozone Products, and Reduces Lipid Peroxidation of Cellular Membranes1

    PubMed Central

    Loreto, Francesco; Velikova, Violeta

    2001-01-01

    Many plants invest carbon to form isoprene. The role of isoprene in plants is unclear, but many experiments showed that isoprene may have a role in protecting plants from thermal damage. A more general antioxidant action has been recently hypothesized on the basis of the protection offered by exogenous isoprene in nonemitting plants exposed to acute ozone doses. We inhibited the synthesis of endogenous isoprene by feeding fosmidomycin and observed that Phragmites australis leaves became more sensitive to ozone than those leaves forming isoprene. Photosynthesis, stomatal conductance, and fluorescence parameters were significantly affected by ozone only in leaves on which isoprene was not formed. The protective effect of isoprene was more evident when the leaves were exposed for a long time (8 h) to relatively low (100 nL L−1) ozone levels than when the exposure was short and acute (3 h at 300 nL L−1). Isoprene quenched the amount of H2O2 formed in leaves and reduced lipid peroxidation of cellular membranes caused by ozone. These results indicate that isoprene may exert its protective action at the membrane level, although a similar effect could be obtained if isoprene reacted with ozone before forming active oxygen species. Irrespective of the mechanism, our results suggest that endogenous isoprene has an important antioxidant role in plants. PMID:11743121

  8. 21 CFR 172.802 - Acetone peroxides.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Acetone peroxides. 172.802 Section 172.802 Food... Multipurpose Additives § 172.802 Acetone peroxides. The food additive acetone peroxides may be safely used in... acetone peroxide, with minor proportions of higher polymers, manufactured by reaction of hydrogen peroxide...

  9. 21 CFR 172.802 - Acetone peroxides.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Acetone peroxides. 172.802 Section 172.802 Food... Multipurpose Additives § 172.802 Acetone peroxides. The food additive acetone peroxides may be safely used in... acetone peroxide, with minor proportions of higher polymers, manufactured by reaction of hydrogen peroxide...

  10. Lipid peroxidation of membrane phospholipids in the vertebrate retina.

    PubMed

    Catala, Angel

    2011-01-01

    Retina is very rich in membranes containing polyunsaturated fatty acids. Reactive oxygen species initiates chain reactions of lipid peroxidation which injure the retina, especially the membranes that play important roles in visual function. Furthermore, biomolecules such as proteins or amino lipids can be covalently modified by lipid decomposition products. In retinal membranes, peroxidation of lipids is also usually accompanied by oxidation of membrane proteins. In consequence, lipid peroxidation may alter the arrangement of proteins in bilayers and by that interfere with their physiological role on the membrane function. Here, we review several studies on the lipid peroxidation of membrane phospholipids in retina. Particular emphasis is placed on the molecular changes of very long chain polyunsaturated fatty acids associated with protein modifications during peroxidation of photoreceptor membranes. Furthermore we use liposomes to analyze peroxidation of retinal lipids. Conjugated dienes formed from oxidized PUFAs, and TBARS products derived from the breakdown of these fatty acids located in phospholipids can be analyzed during lipid peroxidation of liposomes made of retinal lipids using Fe2+ and Fe3+ as initiators.

  11. Diffusion of hydrogen peroxide across DPPC large unilamellar liposomes.

    PubMed

    Abuin, Elsa; Lissi, Eduardo; Ahumada, Manuel

    2012-09-01

    The decomposition of hydrogen peroxide catalyzed by catalase entrapped in the pool of dipalmitoylphosphatidyl choline unilamellar liposomes has been studied. The rate of the process was evaluated by following the production of oxygen as a function of time. Under the experimental conditions employed the rate of oxygen production was controlled by the diffusion of hydrogen peroxide, allowing for the estimation of the diffusion coefficient of hydrogen peroxide across the liposome bilayer. The rate of diffusion across the bilayer increases with the temperature and the presence of fluidizers (n-nonanol), according with changes in the bilayer fluidity, as sensed by 1,6-diphenyl hexatriene (DPH) fluorescence anisotropy. A peculiar aspect of the data is the fast hydrogen peroxide diffusion observed at the bilayer phase transition temperature. This fast diffusion is associated to rafts fluctuations that take place in the partially melted bilayer. These fluctuations have no effect on the microviscosity sensed by DPH. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  12. Continuous synthesis of methyl ethyl ketone peroxide in a microreaction system with concentrated hydrogen peroxide.

    PubMed

    Zhang, Jing; Wu, Wei; Qian, Gang; Zhou, Xing-Gui

    2010-09-15

    Methyl ethyl ketone peroxide (MEKPO) is widely used in polymer industry. It is highly sensitive to heat, friction, shock, flame or other sources of ignition, causing risks in production, storage and transportation. In this article, MEKPO is synthesized at a high throughput with concentrated hydrogen peroxide in a microreactor for on-site and on-demand production. The influences of acid concentration, residence time, feeding rate and ratio, and reaction temperature on the yield and the mass fractions of residual methyl ethyl ketone (MEK) and active oxygen of the product are systematically investigated. Under optimized condition, the reaction is completed in a few seconds, and the product contains less than 2 wt% residual MEK and has a mass active oxygen fraction higher than 22 wt%, which meets the standard for industrial application. Copyright 2010 Elsevier B.V. All rights reserved.

  13. Organic peroxides' gas-particle partitioning and rapid heterogeneous decomposition on secondary organic aerosol

    NASA Astrophysics Data System (ADS)

    Li, Huan; Chen, Zhongming; Huang, Liubin; Huang, Dao

    2016-02-01

    Organic peroxides, important species in the atmosphere, promote secondary organic aerosol (SOA) aging, affect HOx radicals cycling, and cause adverse health effects. However, the formation, gas-particle partitioning, and evolution of organic peroxides are complicated and still unclear. In this study, we investigated in the laboratory the production and gas-particle partitioning of peroxides from the ozonolysis of α-pinene, which is one of the major biogenic volatile organic compounds in the atmosphere and an important precursor for SOA at a global scale. We have determined the molar yields of hydrogen peroxide (H2O2), hydromethyl hydroperoxide (HMHP), peroxyformic acid (PFA), peroxyacetic acid (PAA), and total peroxides (TPOs, including unknown peroxides) and the fraction of peroxides in α-pinene/O3 SOA. Comparing the gas-phase peroxides with the particle-phase peroxides, we find that gas-particle partitioning coefficients of PFA and PAA are 104 times higher than the values from the theoretical prediction, indicating that organic peroxides play a more important role in SOA formation than previously expected. Here, the partitioning coefficients of TPO were determined to be as high as (2-3) × 10-4 m3 µg-1. Even so, more than 80 % of the peroxides formed in the reaction remain in the gas phase. Water changes the distribution of gaseous peroxides, while it does not affect the total amount of peroxides in either the gas or the particle phase. Approx. 18 % of gaseous peroxides undergo rapid heterogeneous decomposition on SOA particles in the presence of water vapor, resulting in the additional production of H2O2. This process can partially explain the unexpectedly high H2O2 yields under wet conditions. Transformation of organic peroxides to H2O2 also preserves OH in the atmosphere, helping to improve the understanding of OH cycling.

  14. Skeletal muscle insulin resistance is induced by 4-hydroxy-2-hexenal, a by-product of n-3 fatty acid peroxidation.

    PubMed

    Soulage, Christophe O; Sardón Puig, Laura; Soulère, Laurent; Zarrouki, Bader; Guichardant, Michel; Lagarde, Michel; Pillon, Nicolas J

    2018-03-01

    Oxidative stress is involved in the pathophysiology of insulin resistance and its progression towards type 2 diabetes. The peroxidation of n-3 polyunsaturated fatty acids produces 4-hydroxy-2-hexenal (4-HHE), a lipid aldehyde with potent electrophilic properties able to interfere with many pathophysiological processes. The aim of the present study was to investigate the role of 4-HHE in the development of insulin resistance. 4-HHE concentration was measured in plasma from humans and rats by GC-MS. Insulin resistance was estimated in healthy rats after administration of 4-HHE using hyperinsulinaemic-euglycaemic clamps. In muscle cells, glucose uptake was measured using 2-deoxy-D-glucose and signalling pathways were investigated by western blotting. Intracellular glutathione was measured using a fluorimetric assay kit and boosted using 1,2-dithiole-3-thione (D3T). Circulating levels of 4-HHE in type 2 diabetic humans and a rat model of diabetes (obese Zucker diabetic fatty rats), were twice those in their non-diabetic counterparts (33 vs 14 nmol/l, p < 0.001), and positively correlated with blood glucose levels. During hyperinsulinaemic-euglycaemic clamps in rats, acute intravenous injection of 4-HHE significantly altered whole-body insulin sensitivity and decreased glucose infusion rate (24.2 vs 9.9 mg kg -1  min -1 , p < 0.001). In vitro, 4-HHE impaired insulin-stimulated glucose uptake and signalling (protein kinase B/Akt and IRS1) in L6 muscle cells. Insulin-induced glucose uptake was reduced from 186 to 141.9 pmol mg -1 min -1 (p < 0.05). 4-HHE induced carbonylation of cell proteins and reduced glutathione concentration from 6.3 to 4.5 nmol/mg protein. Increasing intracellular glutathione pools using D3T prevented 4-HHE-induced carbonyl stress and insulin resistance. 4-HHE is produced in type 2 diabetic humans and Zucker diabetic fatty rats and blunts insulin action in skeletal muscle. 4-HHE therefore plays a causal role in the pathophysiology

  15. Oxygen Mass Flow Rate Generated for Monitoring Hydrogen Peroxide Stability

    NASA Technical Reports Server (NTRS)

    Ross, H. Richard

    2002-01-01

    Recent interest in propellants with non-toxic reaction products has led to a resurgence of interest in hydrogen peroxide for various propellant applications. Because peroxide is sensitive to contaminants, material interactions, stability and storage issues, monitoring decomposition rates is important. Stennis Space Center (SSC) uses thermocouples to monitor bulk fluid temperature (heat evolution) to determine reaction rates. Unfortunately, large temperature rises are required to offset the heat lost into the surrounding fluid. Also, tank penetration to accomodate a thermocouple can entail modification of a tank or line and act as a source of contamination. The paper evaluates a method for monitoring oxygen evolution as a means to determine peroxide stability. Oxygen generation is not only directly related to peroxide decomposition, but occurs immediately. Measuring peroxide temperature to monitor peroxide stability has significant limitations. The bulk decomposition of 1% / week in a large volume tank can produce in excess of 30 cc / min. This oxygen flow rate corresponds to an equivalent temperature rise of approximately 14 millidegrees C, which is difficult to measure reliably. Thus, if heat transfer were included, there would be no temperature rise. Temperature changes from the surrounding environment and heat lost to the peroxide will also mask potential problems. The use of oxygen flow measurements provides an ultra sensitive technique for monitoring reaction events and will provide an earlier indication of an abnormal decomposition when compared to measuring temperature rise.

  16. Crystal structure of rubidium peroxide ammonia disolvate.

    PubMed

    Grassl, Tobias; Korber, Nikolaus

    2017-02-01

    The title compound, Rb2O2·2NH3, has been obtained as a reaction product of rubidium metal dissolved in liquid ammonia and glucuronic acid. As a result of the low-temperature crystallization, a disolvate was formed. To our knowledge, only one other solvate of an alkali metal peroxide is known: Na2O2·8H2O has been reported by Grehl et al. [Acta Cryst. (1995), C51, 1038-1040]. We determined the peroxide bond length to be 1.530 (11) Å, which is in accordance with the length reported by Bremm & Jansen [Z. Anorg. Allg. Chem. (1992), 610, 64-66]. One of the ammonia solvate molecules is disordered relative to a mirror plane, with 0.5 occupancy for the corresponding nitrogen atom.

  17. 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.

  18. Decreased hydrogen peroxide production and mitochondrial respiration in skeletal muscle but not cardiac muscle of the green-striped burrowing frog, a natural model of muscle disuse.

    PubMed

    Reilly, Beau D; Hickey, Anthony J R; Cramp, Rebecca L; Franklin, Craig E

    2014-04-01

    Suppression of disuse-induced muscle atrophy has been associated with altered mitochondrial reactive oxygen species (ROS) production in mammals. However, despite extended hindlimb immobility, aestivating animals exhibit little skeletal muscle atrophy compared with artificially immobilised mammalian models. Therefore, we studied mitochondrial respiration and ROS (H2O2) production in permeabilised muscle fibres of the green-striped burrowing frog, Cyclorana alboguttata. Mitochondrial respiration within saponin-permeabilised skeletal and cardiac muscle fibres was measured concurrently with ROS production using high-resolution respirometry coupled to custom-made fluorometers. After 4 months of aestivation, C. alboguttata had significantly depressed whole-body metabolism by ~70% relative to control (active) frogs, and mitochondrial respiration in saponin-permeabilised skeletal muscle fibres decreased by almost 50% both in the absence of ADP and during oxidative phosphorylation. Mitochondrial ROS production showed up to an 88% depression in aestivating skeletal muscle when malate, succinate and pyruvate were present at concentrations likely to reflect those in vivo. The percentage ROS released per O2 molecule consumed was also ~94% less at these concentrations, indicating an intrinsic difference in ROS production capacities during aestivation. We also examined mitochondrial respiration and ROS production in permeabilised cardiac muscle fibres and found that aestivating frogs maintained respiratory flux and ROS production at control levels. These results show that aestivating C. alboguttata has the capacity to independently regulate mitochondrial function in skeletal and cardiac muscles. Furthermore, this work indicates that ROS production can be suppressed in the disused skeletal muscle of aestivating frogs, which may in turn protect against potential oxidative damage and preserve skeletal muscle structure during aestivation and following arousal.

  19. Radicular peroxide penetration from carbamide peroxide gels during intracoronal bleaching.

    PubMed

    Gökay, O; Ziraman, F; Cali Asal, A; Saka, O M

    2008-07-01

    To evaluate and compare radicular peroxide diffusion from different concentrations of carbamide peroxide bleaching gels. METHODOLOGY; Fifty maxillary premolar teeth were separated into five groups (n = 10). Standardized endodontic access cavities were prepared in the occlusal surfaces, and the root canals were prepared using a step back technique and filled using the lateral compaction technique. The gutta-percha filling was removed 4 mm short of the cemento-enamel junction (CEJ) and a 2-mm-thick glass-ionomer cement base was placed. Outer root surfaces were sealed with wax and nail polish, leaving the coronal third of the tooth and the CEJ exposed. All teeth were immersed in a plastic tube containing 2 mL of distilled water, and the experimental groups were treated with a bleaching agent of either 10%, 17% or 37% carbamide peroxide (CP) or a mixture of 30% hydrogen peroxide (HP) and sodium perborate (SP) placed into the coronal pulp chamber of teeth and left for 24 h. Peroxide penetration was measured using the ferrothiocyanate method. Statistical analysis of data was conducted by using the Kruskal-Wallis Analysis of Variance and Mann-Whitney U test. Higher peroxide penetration occurred with the 30% HP-SP mixture than with the CP bleaching gels, and the 37% CP group also promoted greater peroxide penetration than the other CP groups (P < 0.05). There was no statistically significant difference between 10% and 17% CP groups (P > 0.05). Peroxide penetration of CP gels was significantly lower than that of a HP-SP mixture.

  20. Dissolution of Spent Nuclear Fuel in Carbonate-Peroxide Solution

    SciTech Connect

    Soderquist, Chuck Z.; Hanson, Brady D.

    2010-01-31

    This study shows that spent UO2 fuel can be completely dissolved in a carbonate-peroxide solution apparently without attacking the metallic Mo-Tc-Ru-Rh-Pd fission product phase. Samples of spent nuclear fuel were pulverized and sieved to a uniform size, then duplicate aliquots were weighed into beakers for analysis. One set was dissolved in near-boiling 10M nitric acid, and the other set was dissolved in a solution of ammonium carbonate and hydrogen peroxide at room temperature. All the resulting fuel solutions were then analyzed for Sr-90, Tc-99, Cs-137, plutonium, and Am-241. For all the samples, the concentrations of Cs-137, Sr-90, plutonium, and Am-241 were the same for both the nitric acid dissolution and the ammonium carbonate-hydrogen peroxide dissolution, but the technetium concentration of the ammonium carbonate-hydrogen peroxide fuel solution was only about 25% of the same fuels dissolved in hot nitric acid.

  1. Lipid peroxidation in cell death.

    PubMed

    Gaschler, Michael M; Stockwell, Brent R

    2017-01-15

    Disruption of redox homeostasis is a key phenotype of many pathological conditions. Though multiple oxidizing compounds such as hydrogen peroxide are widely recognized as mediators and inducers of oxidative stress, increasingly, attention is focused on the role of lipid hydroperoxides as critical mediators of death and disease. As the main component of cellular membranes, lipids have an indispensible role in maintaining the structural integrity of cells. Excessive oxidation of lipids alters the physical properties of cellular membranes and can cause covalent modification of proteins and nucleic acids. This review discusses the synthesis, toxicity, degradation, and detection of lipid peroxides in biological systems. Additionally, the role of lipid peroxidation is highlighted in cell death and disease, and strategies to control the accumulation of lipid peroxides are discussed. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  2. Lipid peroxidation in cell death

    PubMed Central

    Gaschler, Michael M.; Stockwell, Brent R.

    2016-01-01

    Disruption of redox homeostasis is a key phenotype of many pathological conditions. Though multiple oxidizing compounds such as hydrogen peroxide are widely recognized as mediators and inducers of oxidative stress, increasingly, attention is focused on the role of lipid hydroperoxides as critical mediators of death and disease. As the main component of cellular membranes, lipids have an indispensible role in maintaining the structural integrity of cells. Excessive oxidation of lipids alters the physical properties of cellular membranes and can cause covalent modification of proteins and nucleic acids. This review discusses the synthesis, toxicity, degradation, and detection of lipid peroxides in biological systems. Additionally, the role of lipid peroxidation is highlighted in disease and death, and strategies to control the accumulation of lipid peroxides are discussed. PMID:28212725

  3. Organic peroxides gas-particle partitioning and rapid heterogeneous decomposition on secondary organic aerosol

    NASA Astrophysics Data System (ADS)

    Li, H.; Chen, Z. M.; Huang, L. B.; Huang, D.

    2015-10-01

    Organic peroxides, important species in the atmosphere, will promote secondary organic aerosols (SOA) aging, affect HOx radicals cycling, and cause adverse health effects. However, the formation, gas-particle partitioning, and evolution of organic peroxides are extremely complicated and still unclear. In this study, we investigate in the laboratory the production and gas-particle partitioning of peroxides from the ozonolysis of α-pinene, which is one of the major biogenic volatile organic compounds in the atmosphere and is an important precursor for SOA at a global scale. We have determined the molar yields of hydrogen peroxide (H2O2), hydroxymethyl hydroperoxide (HMHP), peroxyformic acid (PFA), peroxyacetic acid (PAA) and total peroxides (TPO, including unknown peroxides) and the fraction of peroxides in SOA. Comparing the gas-phase and particle-phase peroxides, we find that gas-particle partitioning coefficients of PFA and PAA are 104 times higher than theoretical prediction, indicating that organic peroxides play a more important role in the SOA formation than expected previously. Here, we give the partitioning coefficients of TPO as (2-3) × 10-4 m3μg-1. Even so, more than 80 % of the peroxides formed in the reaction remain in the gas phase. Water does not affect the total amount of peroxides in either the gas or particle phase, but can change the distribution of gaseous peroxides. About 18 % gaseous peroxides undergo rapid heterogeneous decomposition on SOA particles in the presence of water vapor, resulting in the additional production of H2O2. This process can partially interpret the unexpected high H2O2 yield under wet conditions. Transformation of organic peroxides to H2O2 also saves OH in the atmosphere, helping to improve the understanding of OH cycling.

  4. Bioethanol production from sodium hydroxide/hydrogen peroxide-pretreated water hyacinth via simultaneous saccharification and fermentation with a newly isolated thermotolerant Kluyveromyces marxianu strain.

    PubMed

    Yan, Jinping; Wei, Zhilei; Wang, Qiaoping; He, Manman; Li, Shumei; Irbis, Chagan

    2015-10-01

    In this study, bioethanol production from NaOH/H2O2-pretreated water hyacinth was investigated. Pretreatment of water hyacinth with 1.5% (v/v) H2O2 and 3% (w/v) NaOH at 25 °C increased the production of reducing sugars (223.53 mg/g dry) and decreased the cellulose crystallinity (12.18%), compared with 48.67 mg/g dry and 22.80% in the untreated sample, respectively. The newly isolated Kluyveromyces marxianu K213 showed greater ethanol production from glucose (0.43 g/g glucose) at 45 °C than did the control Saccharomyces cerevisiae angel yeast. The maximum ethanol concentration (7.34 g/L) achieved with K. marxianu K213 by simultaneous saccharification and fermentation (SSF) from pretreated water hyacinth at 42 °C was 1.78-fold greater than that produced by angel yeast S. cerevisiae at 30 °C. The present work demonstrates that bioethanol production achieved via SSF of NaOH/H2O2-pretreated water hyacinth with K. marxianu K213 is a promising strategy to utilize water hyacinth biomass. Copyright © 2015. Published by Elsevier Ltd.

  5. Therapies targeting lipid peroxidation in traumatic brain injury.

    PubMed

    Anthonymuthu, Tamil Selvan; Kenny, Elizabeth Megan; Bayır, Hülya

    2016-06-01

    Lipid peroxidation can be broadly defined as the process of inserting a hydroperoxy group into a lipid. Polyunsaturated fatty acids present in the phospholipids are often the targets for peroxidation. Phospholipids are indispensable for normal structure of membranes. The other important function of phospholipids stems from their role as a source of lipid mediators - oxygenated free fatty acids that are derived from lipid peroxidation. In the CNS, excessive accumulation of either oxidized phospholipids or oxygenated free fatty acids may be associated with damage occurring during acute brain injury and subsequent inflammatory responses. There is a growing body of evidence that lipid peroxidation occurs after severe traumatic brain injury in humans and correlates with the injury severity and mortality. Identification of the products and sources of lipid peroxidation and its enzymatic or non-enzymatic nature is essential for the design of mechanism-based therapies. Recent progress in mass spectrometry-based lipidomics/oxidative lipidomics offers remarkable opportunities for quantitative characterization of lipid peroxidation products, providing guidance for targeted development of specific therapeutic modalities. In this review, we critically evaluate previous attempts to use non-specific antioxidants as neuroprotectors and emphasize new approaches based on recent breakthroughs in understanding of enzymatic mechanisms of lipid peroxidation associated with specific death pathways, particularly apoptosis. We also emphasize the role of different phospholipases (calcium-dependent and -independent) in hydrolysis of peroxidized phospholipids and generation of pro- and anti-inflammatory lipid mediators. This article is part of a Special Issue entitled SI:Brain injury and recovery. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Effects of advanced glycation end products-inductor glyoxal and hydrogen peroxide as oxidative stress factors on rat retinal organ cultures and neuroprotection by UK-14,304.

    PubMed

    Knels, Lilla; Worm, Maximilian; Wendel, Martina; Roehlecke, Cora; Kniep, Eva; Funk, Richard H W

    2008-08-01

    Retinal ganglion cell degeneration is supposed to be mediated by reactive oxygen species (ROS) and advanced glycation end products (AGEs). The alpha2-adrenergic agonist, 5-bromo-N-(4,5-dihydro-1H-imidazol-2-yl)-6-quinoxalinamine (brimonidine; UK-14,304), is said to exert a neuroprotective effect. To investigate these mechanisms in detail, we exposed rat whole mounts to glyoxal or H(2)O(2) and treated them with either UK-14,304 alone or additionally with the phosphatidylinositide 3 kinase (PI3) kinase inhibitor, 2-(4-Morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (Ly 294002). The accumulation of Nepsilon-[carboxymethyl] lysine (CML) was assessed immunohistochemically and changes in intracellular pH (pHi), mitochondrial transmembrane potential (MTMP) and ROS production in cell bodies of multipolar ganglion cell layer were studied by intravital fluorescence microscopy and confocal laser scanning microscopy. Ultrastructural changes in mitochondria of multipolar ganglion cell layer cell bodies were determined by transmission electron microscopy. We found that glyoxal and H(2)O(2) increased accumulation of CML-modified proteins and ROS production and decreased pHi and MTMP in cell bodies of multipolar ganglion cell layer. UK-14,304 could prevent production of ROS, accumulation of CML-modified proteins, ameliorate acidification, preserve MTMP and attenuate ultrastructural damages of ganglion cell mitochondria. Ly 294002 reversed the UK-14,304-mediated attenuation of CML and ROS production. We conclude that the protective effects of UK-14,304 seem partly to be mediated by PI3 kinase-dependent pathways.

  7. 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 time...

  8. 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 time...

  9. 21 CFR 529.1150 - Hydrogen peroxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

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

  10. 21 CFR 172.802 - Acetone peroxides.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Acetone peroxides. 172.802 Section 172.802 Food... Acetone peroxides. The food additive acetone peroxides may be safely used in flour, and in bread and rolls... conditions: (a) The additive is a mixture of monomeric and linear dimeric acetone peroxide, with minor...

  11. 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 removed...

  12. 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 removed...

  13. 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 removed...

  14. 21 CFR 172.802 - Acetone peroxides.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... acetone peroxide, with minor proportions of higher polymers, manufactured by reaction of hydrogen peroxide... grams to 10 grams of hydrogen peroxide equivalent per 100 grams of the additive, plus carrier, for use in flour maturing and bleaching; or (2) approximately 0.75 gram of hydrogen peroxide equivalent per...

  15. 21 CFR 172.802 - Acetone peroxides.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... acetone peroxide, with minor proportions of higher polymers, manufactured by reaction of hydrogen peroxide... grams to 10 grams of hydrogen peroxide equivalent per 100 grams of the additive, plus carrier, for use in flour maturing and bleaching; or (2) approximately 0.75 gram of hydrogen peroxide equivalent per...

  16. Experimental investigation of hydrogen peroxide RF plasmas

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  17. [Indicators of phospholipase activity, lipid peroxidation and antioxidants in bronchial secretions from children with bronchopulmonary diseases].

    PubMed

    Krylov, V I; Olekhnovich, V M; Sorozin, V P; Zhogin, S V

    1984-01-01

    Lipid peroxidation, activity of phospholipases and antioxidants were studied in bronchial secretion products of 5-14 years old children with bronchial asthma. During the acute period of the disease of lipid peroxidation as shown by estimation of hydroperoxides, malone dialdehyde, diene conjugates and Shiff bases and the activity of endogenous phospholipases were distinctly stimulated. Simultaneously, deficiency of endogenous antioxidants, especially of beta-carotin, was observed in the bronchopulmonary system. Content of peroxides and the activity of phospholipases tended to decrease in bronchial secretion products during the periods of remission. The alterations found correlated with the severity of the disease. Role of lipid peroxidation in development of bronchial asthma is discussed.

  18. High level extracellular production of a recombinant alkaline catalase in E. coli BL21 under ethanol stress and its application in hydrogen peroxide removal after cotton fabrics bleaching.

    PubMed

    Yu, Zhenxiao; Zheng, Hongchen; Zhao, Xingya; Li, Shufang; Xu, Jianyong; Song, Hui

    2016-08-01

    The effects of induction parameters, osmolytes and ethanol stress on the productivity of the recombinant alkaline catalase (KatA) in Escherichia coli BL21 (pET26b-KatA) were investigated. The yield of soluble KatA was significantly enhanced by 2% ethanol stress. And a certain amount of Triton X-100 supplementation could markedly improved extracellular ratio of KatA. A total soluble catalase activity of 78,762U/mL with the extracellular ratio of 92.5% was achieved by fed-batch fermentation in a 10L fermentor, which was the highest yield so far. The purified KatA showed high stability at 50°C and pH 6-10. Application of KatA for elimination of H2O2 after cotton fabrics bleaching led to less consumption of water, steam and electric power by 25%, 12% and 16.7% respectively without productivity and quality losing of cotton fabrics. Thus, the recombinant KatA is a promising candidate for industrial production and applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. 21 CFR 178.1005 - Hydrogen peroxide solution.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) INDIRECT FOOD ADDITIVES: ADJUVANTS, PRODUCTION AIDS, AND SANITIZERS Substances Utilized To Control the... peroxide can be determined in distilled water packaged under production conditions (assay to be performed... § 177.1580 of this chapter. Polyethylene-terephthalate polymers Complying with § 177.1630 of this...

  20. Hydrogen Peroxide Production as a Limiting Factor in Xenobiotic Compound Oxidation by Nitrogen-Sufficient Cultures of Bjerkandera sp. Strain BOS55 Overproducing Peroxidases

    PubMed Central

    Kotterman, M.; Wasseveld, R. A.; Field, J. A.

    1996-01-01

    The overproduction of ligninolytic peroxidase by the N-deregulated white rot fungus Bjerkandera sp. strain BOS55 under nitrogen-sufficient conditions had no noteworthy effect on the oxidation of anthracene or the decolorization of the polymeric aromatic dye Poly R-478 in 6-day-old cultures. Only when the endogenous production of H(inf2)O(inf2) was increased by the addition of extra oxygen and glucose could a 2.5-fold increase in the anthracene oxidation rate and a 6-fold increase in the Poly R-478 decolorization rate be observed in high-N cultures with 10- to 35-fold higher peroxidase activities than N-limited cultures. Further increase of the H(inf2)O(inf2) generation rate in high-N cultures with glucose oxidase led to an additional 3.5-fold increase in the anthracene oxidation rate (350 mg liter(sup-1) day(sup-1)) and a 10-fold increase in the Poly R-478 decolorization rate. These results indicate that xenobiotic compound oxidation by white rot fungi cannot be improved by overproducing peroxidases without increasing the endogenous production of H(inf2)O(inf2). The absence of Mn, which decreased the manganese peroxidase titers and increased the lignin peroxidase titers, was associated with up to 95% improvements in the anthracene oxidation rate. The simultaneous presence of Mn and veratryl alcohol was observed to have a synergistic negative effect on the oxidation of anthracene and the decolorization of Poly R-478. PMID:16535276

  1. Hydrogen Peroxide Production as a Limiting Factor in Xenobiotic Compound Oxidation by Nitrogen-Sufficient Cultures of Bjerkandera sp. Strain BOS55 Overproducing Peroxidases.

    PubMed

    Kotterman, M; Wasseveld, R A; Field, J A

    1996-03-01

    The overproduction of ligninolytic peroxidase by the N-deregulated white rot fungus Bjerkandera sp. strain BOS55 under nitrogen-sufficient conditions had no noteworthy effect on the oxidation of anthracene or the decolorization of the polymeric aromatic dye Poly R-478 in 6-day-old cultures. Only when the endogenous production of H(inf2)O(inf2) was increased by the addition of extra oxygen and glucose could a 2.5-fold increase in the anthracene oxidation rate and a 6-fold increase in the Poly R-478 decolorization rate be observed in high-N cultures with 10- to 35-fold higher peroxidase activities than N-limited cultures. Further increase of the H(inf2)O(inf2) generation rate in high-N cultures with glucose oxidase led to an additional 3.5-fold increase in the anthracene oxidation rate (350 mg liter(sup-1) day(sup-1)) and a 10-fold increase in the Poly R-478 decolorization rate. These results indicate that xenobiotic compound oxidation by white rot fungi cannot be improved by overproducing peroxidases without increasing the endogenous production of H(inf2)O(inf2). The absence of Mn, which decreased the manganese peroxidase titers and increased the lignin peroxidase titers, was associated with up to 95% improvements in the anthracene oxidation rate. The simultaneous presence of Mn and veratryl alcohol was observed to have a synergistic negative effect on the oxidation of anthracene and the decolorization of Poly R-478.

  2. Real-time mapping of a hydrogen peroxide concentration profile across a polymicrobial bacterial biofilm using scanning electrochemical microscopy.

    PubMed

    Liu, Xiuhui; Ramsey, Matthew M; Chen, Xiaole; Koley, Dipankar; Whiteley, Marvin; Bard, Allen J

    2011-02-15

    Quantitative detection of hydrogen peroxide in solution above a Streptococcus gordonii (Sg) bacterial biofilm was studied in real time by scanning electrochemical microscopy (SECM). The concentration of hydrogen peroxide was determined to be 0.7 mM to 1.6 mM in the presence of 10 mM glucose over a period of 2 to 8 h. The hydrogen peroxide production measured was higher near the biofilm surface in comparison to Sg grown planktonically. Differential hydrogen peroxide production was observed both by fluorometric as well as by SECM measurements. The interaction between two different species in a bacterial biofilm of Sg and Aggregatibacter actinomycetemcomitans (Aa) in terms of hydrogen peroxide production was also studied by SECM. One-directional y-scan SECM measurements showed the unique spatial mapping of hydrogen peroxide concentration across a mixed species biofilm and revealed that hydrogen peroxide concentration varies greatly dependent upon local species composition.

  3. The rotational spectrum and structure of chlorine peroxide

    NASA Technical Reports Server (NTRS)

    Birk, Manfred; Friedl, Randall R.; Cohen, Edward A.; Pickett, Herbert M.; Sander, Stanley P.

    1989-01-01

    The dimerization products of the ClO + ClO reaction were investigated in a flowing chemical reactor using submillimeter wave spectroscopy. The major products were identified as the chlorine peroxide (Cl2O2) and chlorine dioxide (OClO). The rotational constants as well as a complete set of quartic centrifugal distortion constants were determined. The identification of the chlorine peroxide supports the earlier proposed ClO-dimer mechanisms, which partly explain the ozone hole formation during the Antarctic springtime.

  4. 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

  5. BASIC PEROXIDE PRECIPITATION METHOD OF SEPARATING PLUTONIUM FROM CONTAMINANTS

    DOEpatents

    Seaborg, G.T.; Perlman, I.

    1959-02-10

    A process is described for the separation from each other of uranyl values, tetravalent plutonium values and fission products contained in an aqueous acidic solution. First the pH of the solution is adjusted to between 2.5 and 8 and hydrogen peroxide is then added to the solution causing precipitation of uranium peroxide which carries any plutonium values present, while the fission products remain in solution. Separation of the uranium and plutonium values is then effected by dissolving the peroxide precipitate in an acidic solution and incorporating a second carrier precipitate, selective for plutonium. The plutonium values are thus carried from the solution while the uranium remains flissolved. The second carrier precipitate may be selected from among the group consisting of rare earth fluorides, and oxalates, zirconium phosphate, and bismuth lihosphate.

  6. 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.

  7. Modeling the oxidation of phenolic compounds by hydrogen peroxide photolysis.

    PubMed

    Zhang, Tianqi; Cheng, Long; Ma, Lin; Meng, Fanchao; Arnold, Robert G; Sáez, A Eduardo

    2016-10-01

    Hydrogen peroxide UV photolysis is among the most widely used advanced oxidation processes (AOPs) for the destruction of trace organics in waters destined for reuse. Previous kinetic models of hydrogen peroxide photolysis focus on the dynamics of hydroxyl radical production and consumption, as well as the reaction of the target organic with hydroxyl radicals. However, the rate of target destruction may also be affected by radical scavenging by reaction products. In this work, we build a predictive kinetic model for the destruction of p-cresol by hydrogen peroxide photolysis based on a complete reaction mechanism that includes reactions of intermediates with hydroxyl radicals. The results show that development of a predictive kinetic model to evaluate process performance requires consideration of the complete reaction mechanism, including reactions of intermediates with hydroxyl radicals. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. 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.

  9. Investigating the Stability of Benzoyl Peroxide in Over-the-Counter Acne Medications

    ERIC Educational Resources Information Center

    Kittredge, Marina Canepa; Kittredge, Kevin W.; Sokol, Melissa S.; Sarquis, Arlyne M.; Sennet, Laura M.

    2008-01-01

    One of the most commonly used ingredients in over-the-counter acne treatments in cream, gel, and wash form is benzoyl peroxide. It is an anti-bacterial agent that kills the bacterium ("Propionibacterium acne") involved in the formation of acne. The formulation of these products is extremely difficult owing to the instability of benzoyl peroxide.…

  10. Safety in the Chemical Laboratory. Organic Peroxides.

    ERIC Educational Resources Information Center

    Shanley, Edward S.

    1990-01-01

    Discussed is the thermodynamic instability of organic peroxides. The process of autoxidation which results in peroxide formation is described. Precautions necessary to prevent autoxidation hazards associated with these reagents are suggested. (CW)

  11. Safety Tips: Peroxides Can Be Treacherous.

    ERIC Educational Resources Information Center

    Nagel, Miriam C.

    1984-01-01

    Peroxides are unstable, shock-, thermal-, and friction-sensitive compounds whose sensitivity increases with concentration. In addition, peroxides can form in aging organic solvents and stored alkali metals. Cautions related to storage, use, and disposal of peroxides in the secondary school chemistry laboratory are discussed. (JN)

  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 173.356 - Hydrogen peroxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Hydrogen peroxide. 173.356 Section 173.356 Food... DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Specific Usage Additives § 173.356 Hydrogen peroxide. Hydrogen peroxide (CAS Reg. No. 7722-84-1) may be safely used to treat food in accordance with...

  14. 21 CFR 184.1366 - Hydrogen peroxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Hydrogen peroxide. 184.1366 Section 184.1366 Food... Specific Substances Affirmed as GRAS § 184.1366 Hydrogen peroxide. (a) Hydrogen peroxide (H2O2, CAS Reg. No. 7722-84-1) is also referred to as hydrogen dioxide. It is made by the electrolytic oxidation of...

  15. 21 CFR 184.1366 - Hydrogen peroxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Hydrogen peroxide. 184.1366 Section 184.1366 Food... Specific Substances Affirmed as GRAS § 184.1366 Hydrogen peroxide. (a) Hydrogen peroxide (H2O2, CAS Reg. No. 7722-84-1) is also referred to as hydrogen dioxide. It is made by the electrolytic oxidation of...

  16. Safety issues of tooth whitening using peroxide-based materials.

    PubMed

    Li, Y; Greenwall, L

    2013-07-01

    In-office tooth whitening using hydrogen peroxide (H₂O₂) has been practised in dentistry without significant safety concerns for more than a century. While few disputes exist regarding the efficacy of peroxide-based at-home whitening since its first introduction in 1989, its safety has been the cause of controversy and concern. This article reviews and discusses safety issues of tooth whitening using peroxide-based materials, including biological properties and toxicology of H₂O₂, use of chlorine dioxide, safety studies on tooth whitening, and clinical considerations of its use. Data accumulated during the last two decades demonstrate that, when used properly, peroxide-based tooth whitening is safe and effective. The most commonly seen side effects are tooth sensitivity and gingival irritation, which are usually mild to moderate and transient. So far there is no evidence of significant health risks associated with tooth whitening; however, potential adverse effects can occur with inappropriate application, abuse, or the use of inappropriate whitening products. With the knowledge on peroxide-based whitening materials and the recognition of potential adverse effects associated with the procedure, dental professionals are able to formulate an effective and safe tooth whitening regimen for individual patients to achieve maximal benefits while minimising potential risks.

  17. 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.

  18. Catalyst-free activation of peroxides under visible LED light irradiation through photoexcitation pathway.

    PubMed

    Gao, Yaowen; Li, Yixi; Yao, Linyu; Li, Simiao; Liu, Jin; Zhang, Hui

    2017-05-05

    Catalysts are known to activate peroxides to generate active radicals (i.e., hydroxyl radical (OH) and sulfate radical (SO4-)) under certain conditions, but the activation of peroxides in the absence of catalysts under visible light irradiation has been rarely reported. This work demonstrates a catalyst-free activation of peroxides for the generation of OH and/or SO4- through photoexcited electron transfer from organic dyes to peroxides under visible LED light irradiation, where Rhodamine B (RhB) and Eosin Y (EY) were selected as model dyes. The formation of OH and/or SO4- in the reactions and the electron transfer from the excited dyes to peroxides were validated via electron paramagnetic resonance (EPR), photoluminescence (PL) spectra and cyclic voltammetry (CV). The performance of the peroxide/dye/Vis process was demonstrated to be altered depending on the target substrate. Meanwhile, the peroxide/dye/Vis process was effective for simultaneous decolorization of dyes and production of active radicals under neutral even or basic conditions. The findings of this study clarified a novel photoexcitation pathway for catalyst-free activation of peroxides under visible light irradiation, which could avoid the secondary metal ion (dissolved or leached) pollution from the metal-based catalysts and expand the application range of the peroxide-based catalytic process. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Zinc dioxide nanoparticulates: a hydrogen peroxide source at moderate pH.

    PubMed

    Wolanov, Yitzhak; Prikhodchenko, Petr V; Medvedev, Alexander G; Pedahzur, Rami; Lev, Ovadia

    2013-08-06

    Solid peroxides are a convenient source of hydrogen peroxide, which once released can be readily converted to active oxygen species or to dissolved dioxygen. A zinc peroxide nanodispersion was synthesized and characterized, and its solubility was determined as a function of pH and temperature. We show that zinc peroxide is much more stable in aqueous solutions compared to calcium and magnesium peroxides and that it retains its peroxide content down to pH 6. At low pH conditions H2O2 release is thermodynamically controlled and its dissolution product, Zn(2+), is highly soluble, and thus, hydrogen peroxide release can be highly predictable. The Gibbs free energy of formation of zinc peroxide was found to be -242.0 ± 0.4 kJ/mol and the enthalpy of formation was -292.1 ± 0.7 kJ/mol, substantially higher than theoretically predicted before. The biocidal activity of zinc peroxide was determined by inactivation studies with Escherichia coli cultures, and the activity trend agrees well with the thermodynamic predictions.

  20. 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.

  1. Advanced glycation endproducts cause lipid peroxidation in the human neuronal cell line SH-SY5Y.

    PubMed

    Gasic-Milenkovic, Jovana; Loske, Claudia; Münch, Gerald

    2003-02-01

    Advanced glycation endproducts (AGEs), sugar-derived protein modifications and lipid peroxidation products are prominent features of Alzheimer's disease. AGEs accumulate on beta-amyloid plaques during the course of the disease and can exert chronic oxidative stress via receptor-mediated mechanisms. Lipid peroxidation products such as hydroxynonenal, further markers of oxidative stress, are also increased in Alzheimer's diesease. In this study we present evidence for a direct biochemical link between AGEs and lipid peroxidation. Our results show that AGEs induce lipid peroxidation in a neuronal cell line in a dose-dependant manner, and that blocking the specific AGE-receptor RAGE, as well as using different antioxidants (alpha-lipoic acid, N-acetylcysteine, 17 beta-estradiol or aminoguanidine) can reduce the AGE-mediated formation of lipid peroxidation products. Thus, both RAGE antagonists and scavengers of oxygen free radicals could be useful in protecting brain tissue from lipid peroxidation and its pathophysilogical consequences that occur in Alzheimer's disease.

  2. 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.

  3. 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.

  4. Dynamics of Uranyl Peroxide Nanocapsules

    SciTech Connect

    Nyman, May; Alam, Todd M.

    2012-11-30

    Discrete aqueous metal oxide polyionic clusters that include aluminum polycations, transition-metal polyoxometalates, and the actinyl peroxide clusters have captivated the interest of scientists in the realm of both their fundamental and applied chemistries. Yet the counterions for these polycations or polyanions are often ignored, even though they are imperative for solubility, crystallization, purification, and even templating cluster formation. The actinyl peroxide clusters have counterions not only external, but internal to the hollow peroxide capsules. In this study, we reveal the dynamic behavior of these internal alkali counterions via solid-state and liquid NMR experiments. These studies on two select cluster geometries, those containing 24 and 28 uranyl polyhedra, respectively, show that the capsules-like clusters are not rigid entities. Rather, the internal alkalis both have mobility inside the capsules, as well as exchange with species in the media in which they are dissolved. The alkali mobilities are affected by both what is inside the clusters as well as the composition of the dissolving medium.

  5. Lipid peroxidation is essential for α-synuclein-induced cell death.

    PubMed

    Angelova, Plamena R; Horrocks, Mathew H; Klenerman, David; Gandhi, Sonia; Abramov, Andrey Y; Shchepinov, Mikhail S

    2015-05-01

    Parkinson's disease is the second most common neurodegenerative disease and its pathogenesis is closely associated with oxidative stress. Deposition of aggregated α-synuclein (α-Syn) occurs in familial and sporadic forms of Parkinson's disease. Here, we studied the effect of oligomeric α-Syn on one of the major markers of oxidative stress, lipid peroxidation, in primary co-cultures of neurons and astrocytes. We found that oligomeric but not monomeric α-Syn significantly increases the rate of production of reactive oxygen species, subsequently inducing lipid peroxidation in both neurons and astrocytes. Pre-incubation of cells with isotope-reinforced polyunsaturated fatty acids (D-PUFAs) completely prevented the effect of oligomeric α-Syn on lipid peroxidation. Inhibition of lipid peroxidation with D-PUFAs further protected cells from cell death induced by oligomeric α-Syn. Thus, lipid peroxidation induced by misfolding of α-Syn may play an important role in the cellular mechanism of neuronal cell loss in Parkinson's disease. We have found that aggregated α-synuclein-induced production of reactive oxygen species (ROS) that subsequently stimulates lipid peroxidation and cell death in neurons and astrocytes. Specific inhibition of lipid peroxidation by incubation with reinforced polyunsaturated fatty acids (D-PUFAs) completely prevented the effect of α-synuclein on lipid peroxidation and cell death. © 2015 The Authors. Journal of Neurochemistry published by John Wiley & Sons Ltd on behalf of The International Society for Neurochemistry.

  6. Tetrafluoroethylene telomerization initiated by benzoyl peroxide

    NASA Astrophysics Data System (ADS)

    Bolshakov, A. I.; Kuzina, S. I.; Kiryukhin, D. P.

    2017-03-01

    The radical telomerization of tetrafluoroethylene initiated by benzoyl peroxide (BP) photolysis at λ ≥ 365 nm is studied in acetone, dichloromethane, carbon tetrachloride, and Freon 114B2 at 25°C. The products of synthesis are a mixture of telomers of different molar masses, segregated into soluble and insoluble fractions. To characterize the radicals initiating telomerization, crystalline BP and its solution in ethanol are subjected to low-temperature (77 K) photolysis, with the liquid system serving as a model for BP behavior in solutions of telogens. It is established that radicals are not only initiators but also participate in chain termination reactions, lowering the telomers' molar mass and thus raising the proportion of the soluble fraction. Telomerization initiated by an initiator compound versus initiation by gamma radiation are compared and discussed.

  7. Iron Supplements and Magnesium Peroxide: An Example of a Hazardous Combination in Self-Medication.

    PubMed

    Vrolijk, Misha F; Opperhuizen, Antoon; Jansen, Eugène H J M; Bast, Aalt; Haenen, Guido R M M

    2016-10-01

    The use of self-medication, which includes dietary supplements and over-the-counter drugs, is still on the rise, while safety issues are not well addressed yet. This especially holds for combinations. For example, iron supplements and magnesium peroxide both produce adverse effects via the formation of reactive oxygen species (ROS). This prompted us to investigate the effect of the combination of three different iron supplements with magnesium peroxide on ROS formation. Hydroxyl radical formation by the three iron supplements either combined with magnesium peroxide or alone was determined by performing a deoxyribose assay. Free iron content of iron supplements was determined using ferrozine assay. To determine hydrogen peroxide formation by magnesium peroxide, a ferrous thiocyanate assay was performed. Finally, electron spin resonance spectroscopy (ESR) was performed to confirm the formation of hydroxyl radicals. Our results show that magnesium peroxide induces the formation of hydrogen peroxide. All three iron supplements induced the formation of the extremely reactive hydroxyl radical, although the amount of radicals formed by the different supplements differed. It was shown that combining iron supplements with magnesium peroxide increases radical formation. The formation of hydroxyl radicals after the combination was confirmed with ESR. All three iron supplements contained labile iron and induced the formation of hydroxyl radicals. Additionally, magnesium peroxide in water yields hydrogen peroxide, which is converted into hydroxyl radicals by iron. Hence, iron supplements and magnesium peroxide is a hazardous combination and exemplifies that more attention should be given to combinations of products used in self-medication. © 2016 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

  8. Are 2 combined antimicrobial mechanisms better than 1 for the treatment of acne vulgaris? Clinical and antimicrobial results of a topical combination product containing 1% clindamycin and 5% benzoyl peroxide. Introduction.

    PubMed

    Leyden, J

    2001-02-01

    Acne vulgaris is the most common chronic skin condition seen by dermatologists. Available topical therapies include comedolytic agents such as tretinoin, adapalene, azelaic acid, tazarotene, and salicylic acid; bactericidal agents such as benzoyl peroxide; antibiotics such as clindamycin, erythromycin, and tetracycline; and anti-inflammatory agents such as sodium sulfacetamide and metronidazole. Therapeutic failure with some antibiotic regimens due to the presence or development of resistant strains is becoming an increasing problem in the treatment of acne. One strategy aimed at limiting the resistant Propionibacterium acnes population is the use of treatment regimens that incorporate agents with complementary but different mechanisms of action. A combination gel consisting of 5% benzoyl peroxide and 1% clindamycin has recently become available. This supplement summarizes the dermatopharmacology, clinical efficacy, and tolerability of this combination gel, along with its potential role in the management of acne vulgaris.

  9. Peroxides and peroxide-degrading enzymes in the thyroid.

    PubMed

    Schweizer, Ulrich; Chiu, Jazmin; Köhrle, Josef

    2008-09-01

    Iodination of thyroglobulin is the key step of thyroid hormone biosynthesis. It is catalyzed by thyroid peroxidase and occurs within the follicular space at the apical plasma membrane. Hydrogen peroxide produced by thyrocytes as an oxidant for iodide may compromise cellular and genomic integrity of the surrounding cells, unless these are sufficiently protected by peroxidases. Thus, peroxidases play two opposing roles in thyroid biology. Both aspects of peroxide biology in the thyroid are separated in space and time and respond to the different physiological states of the thyrocytes. Redox-protective peroxidases in the thyroid are peroxiredoxins, glutathione peroxidases, and catalase. Glutathione peroxidases are selenoenzymes, whereas selenium-independent peroxiredoxins are functionally linked to the selenoenzymes of the thioredoxin reductase family through their thioredoxin cofactors. Thus, selenium impacts directly and indirectly on protective enzymes in the thyroid, a link that has been supported by animal experiments and clinical observations. In view of this relationship, it is remarkable that rather little is known about selenoprotein expression and their potential functional roles in the thyroid. Moreover, selenium-dependent and -independent peroxidases have rarely been examined in the same studies. Therefore, we review the relevant literature and present expression data of both selenium-dependent and -independent peroxidases in the murine thyroid.

  10. 7-Hydroxycholestrol as a possible biomarker of cellular lipid peroxidation: difference between cellular and plasma lipid peroxidation.

    PubMed

    Saito, Yoshiro; Noguchi, Noriko

    2014-04-11

    Polyunsaturated fatty acids and their esters are known to be susceptible to free radical-mediated oxidation, whereas cholesterol is thought to be more resistant to oxidation. In fact, it has been observed that in the case of plasma lipid peroxidation, the amount of oxidation products of polyunsaturated fatty acids such as linoleic acid was higher than that of cholesterol. In contrast, during oxidative stress-induced cellular lipid peroxidation, oxidation products of cholesterol such as 7-hydroxycholesterol (7-OHCh) were detected in greater amounts than those of linoleates such as hydroxyoctadecadienoic acid (HODE). There are several forms of oxidation products of cholesterol and linoleates in vivo, namely, hydroperoxides, as well as the hydroxides of both the free and ester forms of cholesterol and linoleates. To evaluate these oxidation products, a method used to determine the lipid oxidation products after reduction and saponification was developed. With this method, several forms of oxidation products of cholesterol and linoleates are measured as total 7-OHCh (t7-OHCh) and total HODE (tHODE), respectively. During free radical-mediated lipid peroxidation in plasma, the amount of tHODE was 6.3-fold higher than that of t7-OHCh. In contrast, when Jurkat cells were exposed to free radicals, the increased amount of cellular t7-OHCh was 5.7-fold higher than that of tHODE. Higher levels of t7-OHCh than those of tHODE have also been observed in selenium-deficient Jurkat cells and glutamate-treated neuronal cells. These results suggest that, in contrast to plasma oxidation, cellular cholesterol is more susceptible to oxidation than cellular linoleates. Collectively, cholesterol oxidation products at the 7-position may be a biomarker of cellular lipid peroxidation. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. 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.

  12. Oxidation resistant peroxide cross-linked UHMWPE produced by blending and surface diffusion

    NASA Astrophysics Data System (ADS)

    Gul, Rizwan M.; Oral, Ebru; Muratoglu, Orhun K.

    2014-06-01

    Ultra-high molecular weight polyethylene (UHMWPE) has been widely used as acetabular cup in total hip replacement (THR) and tibial component in total knee replacement (TKR). Crosslinking of UHMWPE has been successful used to improve its wear performance leading to longer life of orthopedic implants. Crosslinking can be performed by radiation or organic peroxides. Peroxide crosslinking is a convenient process as it does not require specialized equipment and the level of crosslinking can be manipulated by changing the amount of peroxide added. However, there is concern about the long-term stability of these materials due to possible presence of by-products. Vitamin E has been successfully used to promote long-term oxidative stability of UHMWPE. In this study, UHMWPE has been crosslinked using organic peroxide in the presence of Vitamin E to produce an oxidation resistant peroxide crosslinked material. Crosslinking was performed both in bulk by mixing peroxide and resin, and only on the surface using diffusion of peroxides.The results show that UHMWPE can be crosslinked using organic peroxides in the presence of vitamin E by both methods. However, the level of crosslinking decreases with the increase in vitamin E content. The wear resistance increases with the increase in crosslink density, and oxidation resistance significantly increases due to the presence of vitamin E.

  13. Influence of cysteine and methionine availability on protein peroxide scavenging activity and phenolic stability in emulsions.

    PubMed

    Zhou, Lisa; Elias, Ryan J

    2014-03-01

    Plant phenolics are secondary metabolites that have been shown to confer beneficial health effects in humans. However, many of these compounds undergo metal-catalysed oxidation reactions, leading to the generation of hydrogen peroxide (H2O2) and other reactive oxygen species that may negatively impact product stability. In proteins, methionine (Met) and cysteine (Cys) are capable of reacting directly with peroxides. Thus, the dairy proteins, casein (CAS) and β-lactoglobulin (BLG), were examined for their ability to scavenge H2O2 (400μM) and influence (-)-epigallocatechin-3-gallate (EGCG) oxidation (400μM) in Tween- or sodium dodecyl sulphate (SDS)-stabilised hexadecane emulsions. To examine the effect that the accessibility of these amino acids have on their peroxide scavenging activities, proteins were pre-treated with tert-butyl hydroperoxide (TBHP), a bulky peroxide, to oxidise only solvent accessible Met residues or H2O2, the smallest peroxide, to oxidise buried Met residues. In CAS treatments, higher Met content yielded greater peroxide scavenging activity and EGCG stability. CAS treatments also showed significantly higher peroxide scavenging activity compared to the corresponding BLG treatment. However, BLG peroxide scavenging activity was greatly enhanced in SDS-stabilised emulsions due to protein denaturation and subsequent exposure of previously buried Cys residues. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. 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.

  15. Short time exposure to hydrogen peroxide induces sustained glutathione export from cultured neurons.

    PubMed

    Hohnholt, Michaela C; Dringen, Ralf

    2014-05-01

    Hydrogen peroxide is a normal by-product of cellular metabolism that in higher concentrations can cause oxidative stress. Cultured cerebellar granule neurons efficiently disposed of micromolar concentrations of hydrogen peroxide with half-times in the minute range in a process that predominately involved catalase. Application of up to 100 µM hydrogen peroxide did not affect the cell viability for up to 4h, but caused a time- and concentration-dependent increase in the extracellular glutathione (GSH) content that was accompanied by a matching decrease in the cellular GSH content. Hydrogen peroxide at 100 µM stimulated maximally the GSH export from viable neurons, but did not affect GSH export from cultured astrocytes. The peroxide-induced extracellular GSH accumulation from neurons was lowered by 70% in the presence of MK571, an inhibitor of multidrug resistance protein (Mrp) 1. The extracellular GSH content determined after 4h of incubation was already significantly increased after a 5-min exposure of neurons to hydrogen peroxide and became maximal after 15 min of peroxide application. These data demonstrate that just a short exposure of viable cerebellar granule neurons to micromolar concentrations of hydrogen peroxide stimulates a prolonged Mrp1-mediated export of cellular GSH. This process may compromise the antioxidative potential of neurons and increase their sensitivity toward drugs and toxins. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. PEROXIDE PROCESS FOR SEPARATION OF RADIOACTIVE MATERIALS

    DOEpatents

    Seaborg, G.T.; Perlman, I.

    1958-09-16

    reduced state, from hexavalent uranium. It consists in treating an aqueous solution containing such uranium and plutonium ions with sulfate ions in order to form a soluble uranium sulfate complex and then treating the solution with a soluble thorium compound and a soluble peroxide compound in order to ferm a thorium peroxide carrier precipitate which carries down with it the plutonium peroxide present. During this treatment the pH of the solution must be maintained between 2 and 3.

  17. 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.

  18. 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.

  19. Characterization of peroxidized lipids in Bruch's membrane.

    PubMed

    Spaide, R F; Ho-Spaide, W C; Browne, R W; Armstrong, D

    1999-01-01

    To determine if peroxidized lipids occur in Bruch's membrane isolates and to characterize the type present in human necropsy specimens. Bruch's membrane isolates from eye bank eyes obtained from 13 white donors were homogenized. Measurement of peroxidized lipids was done with the fluorometric thiobarbituric acid assay and high pressure liquid chromatography. Bruch's membrane isolate homogenates contained native unsaturated fatty acids and peroxidized lipids in a ratio of about 200:1. The amount of thiobarbituric acid reacting substances increased exponentially with age. The peroxidized lipids identified in Bruch's membrane isolates were derived from long chain polyunsaturated fatty acids, particularly docosahexaenoic acid and linolenic acid, which are normally found in the photoreceptor outer segments. Lipids are known to accumulate in Bruch's membrane, an acellular layer with no known intrinsic mechanisms to combat lipid peroxidation. In related studies, lipid peroxides have been shown to induce neovascularization by inducing expression of a cascade of angiogenic cytokines. This is the first study to show that lipid peroxides, biological molecules that have the potential to incite new vessel growth, occur in Bruch's membrane. The increase in amount of peroxidized lipids with age, combined with their vasogenic potential, suggests that peroxidized lipids may play a role in the etiology of age-related macular degeneration, particularly choroidal neovascularization.

  20. 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.

  1. Differential anti-lipid peroxidative activity of melatonin

    NASA Astrophysics Data System (ADS)

    Kawanishi, Shinya; Sakurai, Hiromu

    2002-01-01

    Scavenging activities of melatonin, which is a pineal secretory product and functions in circadian biology, and its related compounds against reactive oxygen species such as superoxide anion radical, hydrogen peroxide, hydroxyl radical and singlet oxygen as well as organic peroxide radical (t-BuOO•) were evaluated chemically by using electron spin resonance-spin trap and chemiluminescence methods. Antioxidative activity of the compounds was estimated by IC50 value (µM), 50% inhibiting concentration of a compound against reactive oxygen species formed in each system, and the second-order rate constants ( k 2) for the reactions of the compounds and superoxide anion radical or hydroxyl radical. Because melatonin has exhibited the highest scavenging activity against t-BuOO•, the biochemical anti-lipid peroxide radical scavenging activities of melatonin were examined. We found that melatonin exhibits higher anti-lipid peroxidative activity in the rat brain microsomes than in the rat liver microsomal and liposomal systems, suggesting that melatonin may function as a treatment for reactive oxygen species-related diseases of the brain.

  2. Mechanisms involved in the modulation of astroglial resistance to oxidative stress induced by activated microglia: antioxidative systems, peroxide elimination, radical generation, lipid peroxidation.

    PubMed

    Röhl, Claudia; Armbrust, Elisabeth; Herbst, Eva; Jess, Anne; Gülden, Michael; Maser, Edmund; Rimbach, Gerald; Bösch-Saadatmandi, Christine

    2010-05-01

    Microglia and astrocytes are the cellular key players in many neurological disorders associated with oxidative stress and neuroinflammation. Previously, we have shown that microglia activated by lipopolysaccharides (LPS) induce the expression of antioxidative enzymes in astrocytes and render them more resistant to hydrogen peroxide (H2O2). In this study, we examined the mechanisms involved with respect to the cellular action of different peroxides, the ability to detoxify peroxides, and the status of further antioxidative systems. Astrocytes were treated for 3 days with medium conditioned by purified quiescent (microglia-conditioned medium, MCM[-]) or LPS-activated (MCM[+]) microglia. MCM[+] reduced the cytotoxicity of the organic cumene hydroperoxide in addition to that of H2O2. Increased peroxide resistance was not accompanied by an improved ability of astrocytes to remove H2O2 or an increased expression/activity of peroxide eliminating antioxidative enzymes. Neither peroxide-induced radical generation nor lipid peroxidation were selectively affected in MCM[+] treated astrocytes. The glutathione content of peroxide resistant astrocytes, however, was increased and superoxide dismutase and heme oxygenase were found to be upregulated. These changes are likely to contribute to the higher peroxide resistance of MCM[+] treated astrocytes by improving their ability to detoxify reactive oxygen radicals and oxidation products. For C6 astroglioma cells a protective effect of microglia-derived factors could not be observed, underlining the difference of primary cells and cell lines concerning their mechanisms of oxidative stress resistance. Our results indicate the importance of microglial-astroglial cell interactions during neuroinflammatory processes.

  3. Mechanisms of hydrogen peroxide decomposition in soils.

    PubMed

    Petigara, Bhakti R; Blough, Neil V; Mignerey, Alice C

    2002-02-15

    The rates and mechanisms of hydrogen peroxide (H2O2) decomposition were examined in a series of soil suspensions at H2O2 concentrations comparable to those found in rainwaters. The formation of hydroxyl radical (OH) as a possible decomposition intermediate was investigated using a new, highly sensitive method. In surface soils with higher organic matter or manganese content, H2O2 usually decayed rapidly, with disproportionation to water and dioxygen dominating the decomposition, whereas the formation of the hydroxyl radical (OH) represented <10% of the total H2O2 decomposed. In contrast, for soils with lower organic matter content, H2O2 usually decayed much more slowly, but OH was a major product of the H2O2 decomposed. The decomposition was principally associated with soil particles, not the soil supernatant. Different sterilization techniques indicated that decomposition of H2O2 was at least partly due to biological activity. Because the loss of H2O2 can largely be accommodated by the production of O2 and OH within these soils, our results suggest that disproportionation through a catalase-type mechanism and the production of OH through a Haber-Weiss mechanism represent the principal routes through which H2O2 is lost.

  4. Study of use of different types of hydrogen peroxides (2006-2008).

    PubMed

    Vissers, Marc; Van Parys, Pieter; Audenaert, Joachim; Kerger, Pierrot; De Windt, Wim; Dick, Jan; Gobin, Bruno

    2009-01-01

    Hydrogen peroxides are commonly used in greenhouses for cleaning purposes and disinfection of irrigation water systems, i.e., to prevent clogging by duckweed (Lemna minor), algae and other (micro)organisms. This use contains a potential risk of involuntary contact to the plants, e.g., to roots through irrigation or to the plant leaves through accidental droplets (spraying mist). To help growers to maximize disinfection with minimal risks, the efficacy and plant safety of a variety of commercial available peroxide formulations were compared, i.e., pure peroxide products, peroxide products with additives: Ag, performic acid, peracetic acid and sorbitol. Starting from pure (clean and without fertilizers) irrigation water the peroxides with Ag-stabilisers were most stable and most effective for algae prevention. In screenings for the curative effect on algae, duckweed and bacteria the best results were obtained with peroxide formulations with performic acid. In plant safety tests on potted Ficus benjamina, sprays and irrigations above the plants gave no toxicity till 500 ppm a.i.; irrigations below the plants didn't show toxicity but the plant growth was reduced with weekly applications of 2000 ppm a.i. On the contrary several applications were risky on herbaceous plants, sometimes even with very low dosages (12.5 ppm peroxide).

  5. 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. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. The Reactions of Nitrogen Peroxide with Possible Stabilisers for Propellants

    DTIC Science & Technology

    1957-03-01

    but when this is not so separate provision is necessary, This aspect is not dealt with in this report, nor is the stabilising capacity of picrite ...sole products with nitrogen peroxide are nitrous oxide, water, and carbon dioxide(3); however, propellants containing picrite required the addition of...another suitable stabiliser to combat nitrogen oxy-acids, against which picrite has little effect. 5.3 Substances which are sufficiently reactive to be

  7. The interaction between lipid peroxidation and prostaglandin synthesis in rabbit kidney-medulla slices.

    PubMed Central

    Fujimoto, Y; Tanioka, H; Keshi, I; Fujita, T

    1983-01-01

    Lipid peroxidation induced by ascorbic acid and Fe2+ was inhibited by mepacrine (phospholipase A2 inhibitor) and aspirin (prostaglandin cyclo-oxygenase inhibitor) in rabbit kidney-medulla slices. Moreover, ascorbic acid and Fe2+ potentiated the inhibitory effect on prostaglandin E2 formation by mepacrine, but they had no influence on prostaglandin E2 production decreased by aspirin. Lipid peroxidation induced by ascorbic acid and Fe2+ appears to be affecting the activity of prostaglandin endoperoxide synthase. These results suggest that lipid peroxidation is connected closely with the prostaglandin-generating system, and it has the potential to modulate the turnover of arachidonic acid and prostaglandin synthesis. PMID:6575779

  8. The possible role of squalene and its peroxide of the sebum in the occurrence of sunburn and protection from the damage caused by U.V. irradiation.

    PubMed

    Ohsawa, K; Watanabe, T; Matsukawa, R; Yoshimura, Y; Imaeda, K

    1984-05-01

    To clarify the role of squalene peroxide in the occurrence of skin damage from sunburn, the optimum condition of squalene peroxidation and the effect of squalene peroxide on cutaneous tissue were examined. Peroxidation of squalene was more easily induced than palmitoleic acid and oleic acid in the unsaturated lipid occurred in sebum. The peroxidation of squalene gradually occurred by U.V. irradation, and it is parallel to increases in the malonyldialdehyde production (production of lipoperoxide). This peroxidation easily carries out in the case of high temperature (40 degrees C than 30 degrees C), and in the case of low pH. Good correspondence was recognized among the spectrum of natural daylight, U.V. absorption spectrum of squalene and erythema curve. Squalene and its peroxide have an important role in the occurrence of sunburn, and/or protection from damage caused by U.V. irradiation.

  9. [Advances in peroxide-based decontaminating technologies].

    PubMed

    Xi, Hai-ling; Zhao, San-ping; Zhou, Wen

    2013-05-01

    With the boosting demand for eco-friendly decontaminants, great achievements in peroxide-based decontaminating technologies have been made in recent years. These technologies have been applied in countering chemical/biological terrorist attacks, dealing with chemical/biological disasters and destructing environmental pollutants. Recent research advances in alpha-nucleophilic/oxidative reaction mechanisms of peroxide-based decontamination against chemical warfare agents were reviewed, and some classical peroxide-based decontaminants such as aqueous decontaminating solution, decontaminating foam, decontaminating emulsions, decontaminating gels, decontaminating vapors, and some newly developed decontaminating media (e.g., peroxide-based self-decontaminating materials and heterogeneous nano-catalytic decontamination systems) were introduced. However, currently available peroxide-based decontaminants still have some deficiencies. For example, their decontamination efficiencies are not as high as those of chlorine-containing decontaminants, and some peroxide-based decontaminants show relatively poor effect against certain agents. More study on the mechanisms of peroxide-based decontaminants and the interfacial interactions in heterogeneous decontamination media is suggested. New catalysts, multifunctional surfactants, self-decontaminating materials and corrosion preventing technologies should be developed before peroxide-based decontaminants really become true "green" decontaminants.

  10. 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)

  11. 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...

  12. 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... Material § 58.431 Hydrogen peroxide. The solution shall comply with the specification of the U.S. Pharmacopeia, except that it may exceed the concentration specified therein and it does not contain added...

  13. 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... Material § 58.431 Hydrogen peroxide. The solution shall comply with the specification of the U.S. Pharmacopeia, except that it may exceed the concentration specified therein and it does not contain added...

  14. 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... Material § 58.431 Hydrogen peroxide. The solution shall comply with the specification of the U.S. Pharmacopeia, except that it may exceed the concentration specified therein and it does not contain added...

  15. 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 U.S...

  16. 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 U.S...

  17. Hydroxynonenal and uncoupling proteins: a model for protection against oxidative damage.

    PubMed

    Echtay, Karim S; Pakay, Julian L; Esteves, Telma C; Brand, Martin D

    2005-01-01

    In this mini review we summarize recent studies from our laboratory that show the involvement of superoxide and the lipid peroxidation product 4-hydroxynonenal in the regulation of mitochondrial uncoupling. Superoxide produced during mitochondrial respiration is a major cause of the cellular oxidative damage that may underlie degenerative diseases and ageing. Superoxide production is very sensitive to the magnitude of the mitochondrial protonmotive force, so can be strongly decreased by mild uncoupling. Superoxide is able to give rise to other reactive oxygen species, which elicit deleterious effects primarily by oxidizing intracellular components, including lipids, DNA and proteins. Superoxide-induced lipid peroxidation leads to the production of reactive aldehydes, including 4-hydroxynonenal. These aldehydic lipid peroxidation products are in turn able to modify proteins such as mitochondrial uncoupling proteins and the adenine nucleotide translocase, converting them into active proton transporters. This activation induces mild uncoupling and so diminishes mitochondrial superoxide production, hence protecting against disease and oxidative damage at the expense of energy production.

  18. 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.

  19. Peroxide test strips detect added hydrogen peroxide in raw milk at levels affecting bacterial load.

    PubMed

    Martin, Nicole H; Friedlander, Adam; Mok, Allen; Kent, David; Wiedmann, Martin; Boor, Kathryn J

    2014-10-01

    Hydrogen peroxide (H2O2) has a long-established history of use as a preservative in milk worldwide. The use of H2O2 to activate the inherent lactoperoxidase enzyme system has dramatically improved the quality of raw dairy products in areas in which cooling is not widely available. In the United States, however, where refrigeration is widely available, the addition of H2O2 to milk is not permitted, with the exception of certain applications prior to cheesemaking and during the preparation of modified whey. Due to the relatively quick deterioration of H2O2 in fluid milk, the detection of raw milk adulterated with the compound can be challenging. In this study we evaluated (i) total aerobic bacterial counts and (ii) ability of peroxide test strips to detect H2O2 in raw milk with various concentrations (0, 100, 300, 500, 700, and 900 ppm) of added H2O2, incubated at both 6 and 21°C for 0, 24, and 48 h. Results showed that at both 6 and 21°C the H2O2 concentration and time had a significant effect on bacterial loads in raw milk. Additionally, commercially available test strips were able to detect H2O2 in raw milk, with predicted probability of >90%, immediately after addition and after 24 and 48 h for the higher concentrations used, offering a viable method for detecting raw milk adulteration with H2O2.

  20. 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

  1. How Hydrogen Peroxide Is Metabolized by Oxidized Cytochrome c Oxidase

    PubMed Central

    2015-01-01

    In the absence of external electron donors, oxidized bovine cytochrome c oxidase (CcO) exhibits the ability to decompose excess H2O2. Depending on the concentration of peroxide, two mechanisms of degradation were identified. At submillimolar peroxide concentrations, decomposition proceeds with virtually no production of superoxide and oxygen. In contrast, in the millimolar H2O2 concentration range, CcO generates superoxide from peroxide. At submillimolar concentrations, the decomposition of H2O2 occurs at least at two sites. One is the catalytic heme a3–CuB center where H2O2 is reduced to water. During the interaction of the enzyme with H2O2, this center cycles back to oxidized CcO via the intermediate presence of two oxoferryl states. We show that at pH 8.0 two molecules of H2O2 react with the catalytic center accomplishing one cycle. In addition, the reactions at the heme a3–CuB center generate the surface-exposed lipid-based radical(s) that participates in the decomposition of peroxide. It is also found that the irreversible decline of the catalytic activity of the enzyme treated with submillimolar H2O2 concentrations results specifically from the decrease in the rate of electron transfer from heme a to the heme a3–CuB center during the reductive phase of the catalytic cycle. The rates of electron transfer from ferrocytochrome c to heme a and the kinetics of the oxidation of the fully reduced CcO with O2 were not affected in the peroxide-modified CcO. PMID:24840065

  2. How hydrogen peroxide is metabolized by oxidized cytochrome c oxidase.

    PubMed

    Jancura, Daniel; Stanicova, Jana; Palmer, Graham; Fabian, Marian

    2014-06-10

    In the absence of external electron donors, oxidized bovine cytochrome c oxidase (CcO) exhibits the ability to decompose excess H2O2. Depending on the concentration of peroxide, two mechanisms of degradation were identified. At submillimolar peroxide concentrations, decomposition proceeds with virtually no production of superoxide and oxygen. In contrast, in the millimolar H2O2 concentration range, CcO generates superoxide from peroxide. At submillimolar concentrations, the decomposition of H2O2 occurs at least at two sites. One is the catalytic heme a3-CuB center where H2O2 is reduced to water. During the interaction of the enzyme with H2O2, this center cycles back to oxidized CcO via the intermediate presence of two oxoferryl states. We show that at pH 8.0 two molecules of H2O2 react with the catalytic center accomplishing one cycle. In addition, the reactions at the heme a3-CuB center generate the surface-exposed lipid-based radical(s) that participates in the decomposition of peroxide. It is also found that the irreversible decline of the catalytic activity of the enzyme treated with submillimolar H2O2 concentrations results specifically from the decrease in the rate of electron transfer from heme a to the heme a3-CuB center during the reductive phase of the catalytic cycle. The rates of electron transfer from ferrocytochrome c to heme a and the kinetics of the oxidation of the fully reduced CcO with O2 were not affected in the peroxide-modified CcO.

  3. Rearrangements of organic peroxides and related processes

    PubMed Central

    Yaremenko, Ivan A; Vil’, Vera A; Demchuk, Dmitry V

    2016-01-01

    Summary This review is the first to collate and summarize main data on named and unnamed rearrangement reactions of peroxides. It should be noted, that in the chemistry of peroxides two types of processes are considered under the term rearrangements. These are conventional rearrangements occurring with the retention of the molecular weight and transformations of one of the peroxide moieties after O–O-bond cleavage. Detailed information about the Baeyer−Villiger, Criegee, Hock, Kornblum−DeLaMare, Dakin, Elbs, Schenck, Smith, Wieland, and Story reactions is given. Unnamed rearrangements of organic peroxides and related processes are also analyzed. The rearrangements and related processes of important natural and synthetic peroxides are discussed separately. PMID:27559418

  4. In-use peroxide kinetics of 10% hydrogen peroxide whitening strips.

    PubMed

    Gerlach, Robert W; Barker, Matthew L; Sagel, Paul A; Ralston, Christopher S; McMillan, Donna A

    2008-01-01

    Clinical research was conducted to establish the peroxide degradation profile of a very thin 10% hydrogen peroxide bleaching gel delivered on a flexible polyethylene strip. Sixteen subjects participated in this study of Crest Whitestrips Premium, a thin layer of 10% hydrogen peroxide gel. Application was supervised, and strips were removed after five, 10, 30, and 60 minutes. Samples were collected from the strips, teeth, gingiva, and saliva, and peroxide levels were derived using a colorimetric peroxide assay. At five minutes, median peroxide concentrations were 7.3%, 6.4%, and 0.7% for strips, teeth, and gingiva, respectively, declining to 4.6%, 2.9%, and 0.1% at 30 minutes. Salivary samples never exceeded a median concentration of 0.014% at any time point. Samples differed significantly (p < 0.01) with respect to the 30- and 60-minute area-under-the-curve calculations, with the highest concentrations on the strip and teeth, and the lowest on the gingiva and in saliva. Median peroxide concentrations on strips and teeth remained above 2% over 60 minutes. At all post-treatment time points, the gingival peroxide concentration was an order of magnitude lower than the teeth samples. Use of 10% hydrogen peroxide whitening strips yielded appreciable peroxide on teeth over a 60-minute period, with rapid peroxide degradation on the gingiva, and exceedingly low accumulation in saliva anytime during use.

  5. [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.

  6. In vivo evaluation of the effects of 10% carbamide peroxide and 3.5% hydrogen peroxide on the enamel surface.

    PubMed

    Berga Caballero, Amparo; Forner Navarro, Leopoldo; Amengual Lorenzo, José

    2007-09-01

    Bleaching of vital teeth performed at home by the patient under the dentist's supervision, using low-concentration peroxides and custom-fitted trays specifically designed for this purpose, is one of several options for this type of dental treatment, whether alone or in combination with another in-office bleaching technique. The objective of this study is to analyse the effect on the enamel surface of two bleaching products recommended for this technique. Two bleaching products were used: VivaStyle (Vivadent), a 10% carbamide peroxide, and FKD (Kin), a 3.5% hydrogen peroxide. They were applied in trays to the anterior teeth of 20 patients (10 in each group). The application times were 2 and 3 hours a day respectively for 28-33 days. Replicas of the tooth surfaces before and after treatment were obtained. These were observed with a scanning electron microscope. The images obtained showed that the tooth surfaces remained entire and the enamel surface structures remained normal. The results show that neither of the products affects the enamel surface: no post-operatory changes were observed.

  7. Global Phospholipidomics Analysis Reveals Selective Pulmonary Peroxidation Profiles Upon Inhalation of Single Walled Carbon Nanotubes

    PubMed Central

    Tyurina, Yulia Y.; Kisin, Elena R.; Murray, Ashley; Tyurin, Vladimir A.; Kapralova, Valentina I.; Sparvero, Louis J.; Amoscato, Andrew A.; Samhan-Arias, Alejandro K.; Swedin, Linda; Lahesmaa, Riitta; Fadeel, Bengt; Shvedova, Anna A.; Kagan, Valerian E.

    2011-01-01

    It is commonly believed that nanomaterials cause non-specific oxidative damage. Our mass spectrometry-based oxidative lipidomics analysis of all major phospholipid classes revealed highly selective patterns of pulmonary peroxidation after inhalation exposure of mice to single-walled carbon nanotubes. No oxidized molecular species were found in two most abundant phospholipid classes – phosphatidylcholine and phosphatidylethanolamine. Peroxidation products were identified in three relatively minor classes of anionic phospholipids, cardiolipin, phosphatidylserine and phosphatidylinositol whereby oxygenation of polyunsaturated fatty acid residues also showed unusual substrate specificity. This non-random peroxidation coincided with the accumulation of apoptotic cells in the lung. A similar selective phospholipid peroxidation profile was detected upon incubation of a mixture of total lung lipids with H2O2/cytochrome c known to catalyze cardiolipin and phosphatidylserine peroxidation in apoptotic cells. The characterized specific phospholipid peroxidation signaling pathways indicate new approaches to the development of mitochondria targeted regulators of cardiolipin peroxidation to protect against deleterious effects of pro-apoptotic effects of single-walled carbon nanotubes in the lung. PMID:21800898

  8. Lipid antioxidants: free radical scavenging versus regulation of enzymatic lipid peroxidation.

    PubMed

    Samhan-Arias, Alejandro K; Tyurina, Yulia Y; Kagan, Valerian E

    2011-01-01

    The essentiality of polyunsaturated lipids makes membranes susceptible to peroxidative modifications. One of the most contemporary examples includes selective peroxidation of cardiolipin in mitochondria of cells undergoing apoptosis. Cardiolipin peroxidation products are required for the mitochondrial membrane permeabilization, release of pro-apoptotic factors and completion of the cell death program. Therefore, search for effective inhibitors of cardiolipin peroxidation is critical to discovery and development of anti-apoptotic antioxidants. Mitochondria contain significant amounts of α-tocopherol, a well known scavenger of reactive free radicals. In the present study, we used an oxidative lipidomics approach to evaluate the effect of α-tocopherol and its homologues with different lengths of the side-chain such as 2,5,7,8,-tetramethyl-2(4-methylpentyl)-6-chromanol and 2,2,5,7,8-pentamethyl-6-chromanol, on oxidation of tetralinoleoyl cardiolipin induced by cytochrome c in the presence of hydrogen peroxide. Our data indicate that vitamin E homologues inhibit not only accumulation of tetralinoleoyl cardiolipin hydroperoxides but also hydroxy-derivatives of tetralinoleoyl cardiolipin formed in the enzymatic peroxidase half-reaction catalyzed by cytochrome c. This suggests that protective effects of vitamin E homologues against tetralinoleoyl cardiolipin peroxidation catalyzed by cytochrome c/hydrogen peroxide are realized largely due to their effects on the peroxidase activity of cytochrome c towards tetralinoleoyl cardiolipin rather than via their scavenging activity.

  9. Metal peroxide- polymer composites for dye degradation

    NASA Astrophysics Data System (ADS)

    Anshu, Ashwini; Vijayaraghavan, R.

    2017-11-01

    Semiconductor metal oxides/its composites with polymers have been explored for dye degradation through photocatalytic mechanism; these require UV or visible light for activation. Hence, there is need to develop (photo) catalyst that work in absence/presence of light. Towards this objective we are exploring metal peroxides and its composites for dye degradation. Here, we report our work on magnesium peroxide and its composites for dye degradation by photochemical pathways. The nanocomposites are synthesized from monomers and peroxides. The synthesized composites have been characterized by IR, DRS and powder XRD. The composites did not degrade dyes in dark.

  10. 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.

  11. High temperature decomposition of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2004-01-01

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

  12. Inactivation of rabies virus by hydrogen peroxide.

    PubMed

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

    2016-02-03

    Development of safe and protective vaccines against infectious pathogens remains a challenge. Inactivation of rabies virus is a critical step in the production of vaccines and other research reagents. Beta-propiolactone (βPL); the currently used inactivating agent for rabies virus is expensive and proved to be carcinogenic in animals. This study aimed to investigate the ability of hydrogen peroxide (H2O2) to irreversibly inactivate rabies virus without affecting its antigenicity and immunogenicity in pursuit of finding safe, effective and inexpensive alternative inactivating agents. H2O2 3% rapidly inactivated a Vero cell adapted fixed rabies virus strain designated as FRV/K within 2h of exposure without affecting its antigenicity or immunogenicity. No residual infectious virus was detected and the H2O2-inactivated vaccine proved to be safe and effective when compared with the same virus harvest inactivated with the classical inactivating agent βPL. Mice immunized with H2O2-inactivated rabies virus produced sufficient level of antibodies and were protected when challenged with lethal CVS virus. These findings reinforce the idea that H2O2 can replace βPL as inactivating agent for rabies virus to reduce time and cost of inactivation process. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. The role of iron in ferritin- and haemosiderin-mediated lipid peroxidation in liposomes.

    PubMed Central

    O'Connell, M J; Ward, R J; Baum, H; Peters, T J

    1985-01-01

    Ferritin and haemosiderin were shown, by the measurement of malondialdehyde production and loss of polyunsaturated fatty acids, to stimulate lipid peroxidation in liposomes. At pH 7.4 ascorbate was additionally required to achieve peroxidation; however, peroxidation occurred at pH 4.5 in the presence of iron-proteins alone. The damage was completely inhibited by the incorporation of chain-breaking antioxidants (alpha-tocopherol and butylated hydroxytoluene) into the liposomes. Metal chelators (desferrioxamine and EDTA) also completely inhibited lipid peroxidation. These and further results indicate that, at pH 4.5, even in the absence of a reducing agent, iron is released from haemosiderin and can mediate oxidative damage to a lipid membrane. PMID:3929767

  14. Determination of berberine in pharmaceutical preparations using acidic hydrogen peroxide-nitrite chemiluminescence system.

    PubMed

    Liang, Yao-Dong; Yu, Chun-Xia

    2013-03-01

    A stronger chemiluminescence (CL) was observed when hydrogen peroxide was mixed with nitrite and berberine in sulfuric acid solution. The stronger CL originated from peroxidation of berberine by peroxynitrous acid that was synthesized online by the mixing of acidic hydrogen peroxide solution with nitrite solution in a flow system. The emitting species was excited state oxyberberine, a peroxidized product of berberine. Based on the stronger CL, a flow injection CL method for the determination of berberine was proposed. Under optimum experimental conditions, the stronger CL intensity was linearly related to the concentration of berberine over the range of 2.0 × 10(-7) -2.0 × 10(-5) mol L(-1) . The limit of detection (s/n = 3) was 6.2 × 10(-8) mol L(-1) . The proposed method has been evaluated by analyzing berberine in pharmaceutical preparations. Copyright © 2011 John Wiley & Sons, Ltd.

  15. The hydrogen peroxide reactivity of peptidylglycine monooxygenase supports a Cu(II)-superoxo catalytic intermediate.

    PubMed

    Bauman, Andrew T; Yukl, Erik T; Alkevich, Katsiaryna; McCormack, Ashley L; Blackburn, Ninian J

    2006-02-17

    We have investigated the reaction of peptidylglycine monooxygenase with hydrogen peroxide to determine whether Cu(II)-peroxo is a likely intermediate. When the oxidized enzyme was reacted with the dansyl-YVG substrate and H(2)O(2), the alpha-hydroxyglycine product was formed. The reaction was catalytic and did not require the presence of additional reductant. When (18)O-labeled H(2)O(2) was reacted with peptidylglycine monooxygenase and substrate anaerobically, oxygen in the product was labeled with (18)O and must therefore be derived from H(2)O(2). However, when the reaction was carried out with H (16)(2)O(2) in the presence of (18)O(2), 60% of the product contained the (18)O label. Therefore, the reaction must proceed via an intermediate that can react directly with dioxygen and thus scramble the label. Under strictly anaerobic conditions (in the presence of glucose and glucose oxidase, where no oxygen was released into the medium from nonenzymatic peroxide decomposition), product formation and peroxide consumption were tightly coupled, and the rate of product formation was identical to that measured under aerobic conditions. Peroxide reactivity was eliminated by a mutation at the Cu(H) center, which should not be involved in the peroxide shunt. Our data lend support to recent proposals that Cu(II)-superoxide is the active species.

  16. 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.

  17. Ultrafast Photoinduced Electron Transfer from Peroxide Dianion.

    PubMed

    Anderson, Bryce L; Maher, Andrew G; Nava, Matthew; Lopez, Nazario; Cummins, Christopher C; Nocera, Daniel G

    2015-06-18

    The encapsulation of peroxide dianion by hexacarboxamide cryptand provides a platform for the study of electron transfer of isolated peroxide anion. Photoinitiated electron transfer (ET) between freely diffusing Ru(bpy)3(2+) and the peroxide dianion occurs with a rate constant of 2.0 × 10(10) M(-1) s(-1). A competing electron transfer quenching pathway is observed within an ion pair. Picosecond transient spectroscopy furnishes a rate constant of 1.1 × 10(10) s(-1) for this first-order process. A driving force dependence for the ET rate within the ion pair using a series of Ru(bpy)3(2+) derivatives allows for the electronic coupling and reorganization energies to be assessed. The ET reaction is nonadiabatic and dominated by a large inner-sphere reorganization energy, in accordance with that expected for the change in bond distance accompanying the conversion of peroxide dianion to superoxide anion.

  18. 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.

  19. Synthesis, properties and transformations of fullerene peroxides

    NASA Astrophysics Data System (ADS)

    Bulgakov, R. G.; Galimov, D. I.; Dzhemilev, U. M.

    2014-08-01

    Methods of synthesis, properties and transformations of fullerene peroxides are considered and systematized for the first time. It is shown that the chemistry of fullerene peroxides is a new approach to functionalization of fullerenes, which has been intensively developing since 2002. Methods of synthesis, mechanisms of formation and reactions of C60 and C70 alkyl peroxides with or without epoxide moieties are discussed. Transformations of fullerene peroxides affording a wide range of fullerene derivatives containing, as addends, halogen or sulfur atoms; epoxide, dioxolane, thiirane, crown ether, aziridine and dioxetane rings, as well as hydroxyl, alkoxyl and carbonyl groups, are considered. Special attention is focused on reactions constituting the basis of a new approach — so-called molecular surgery, which enables the synthesis of open-cage fullerene derivatives. It has been demonstrated that such compounds are good candidates for designing photovoltaic cells and carriers of drugs and radionuclides (for radiopharmaceuticals). The bibliography includes 130 references.

  20. 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.

  1. The biological chemistry of hydrogen peroxide.

    PubMed

    Winterbourn, Christine C

    2013-01-01

    Hydrogen peroxide is generated in numerous biological processes and is implicated as the main transmitter of redox signals. Although a strong oxidant, high activation energy barriers make it unreactive with most biological molecules. It reacts directly with thiols, but for low-molecular-weight thiols and cysteine residues in most proteins, the reaction is slow. The most favored reactions of hydrogen peroxide are with transition metal centers, selenoproteins, and selected thiol proteins. These include proteins such as catalase, glutathione peroxidases, and peroxiredoxins, which, as well as providing antioxidant defense, are increasingly being considered as targets for signal transmission. This overview describes the main biological reactions of hydrogen peroxide and takes a kinetic approach to identifying likely targets in the cell. It also considers diffusion of hydrogen peroxide and constraints to its acting at localized sites. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Peroxidative Activity in Euglena gracilis1

    PubMed Central

    Brown, Richard H.; Collins, Neville; Merrett, Michael J.

    1975-01-01

    Cell-free homogenates of Euglena gracilis contain very low levels of catalase activity as compared to higher plants and some other algae. Purified Euglena cytochrome c acts catalytically as a peroxidase. The observed catalytic activity of cytochrome c in extracts from heterotrophically grown cells was more than enough to account for the observed rates of hydrogen peroxide destruction. The peroxidative activity of Euglena cytochrome c was completely inhibited by 20 mm 3-amino-1,2,4-triazole. PMID:16659224

  3. EFFLUENT TREATMENT FACILITY PEROXIDE DESTRUCTION CATALYST TESTING

    SciTech Connect

    HALGREN DL

    2008-07-30

    The 200 Area Effluent Treatment Facility (ETF) main treatment train includes the peroxide destruction module (PDM) where the hydrogen peroxide residual from the upstream ultraviolet light/hydrogen peroxide oxidation unit is destroyed. Removal of the residual peroxide is necessary to protect downstream membranes from the strong oxidizer. The main component of the PDM is two reaction vessels utilizing granular activated carbon (GAC) as the reaction media. The PDM experienced a number of operability problems, including frequent plugging, and has not been utilized since the ETF changed to groundwater as the predominant feed. The unit seemed to be underperforming in regards to peroxide removal during the early periods of operation as well. It is anticipated that a functional PDM will be required for wastewater from the vitrification plant and other future streams. An alternate media or methodology needs to be identified to replace the GAC in the PDMs. This series of bench scale tests is to develop information to support an engineering study on the options for replacement of the existing GAC method for peroxide destruction at the ETF. A number of different catalysts will be compared as well as other potential methods such as strong reducing agents. The testing should lead to general conclusions on the viability of different catalysts and identify candidates for further study and evaluation.

  4. Effect of americium-241 on luminous bacteria. Role of peroxides.

    PubMed

    Alexandrova, M; Rozhko, T; Vydryakova, G; Kudryasheva, N

    2011-04-01

    The effect of americium-241 ((241)Am), an alpha-emitting radionuclide of high specific activity, on luminous bacteria Photobacterium phosphoreum was studied. Traces of (241)Am in nutrient media (0.16-6.67 kBq/L) suppressed the growth of bacteria, but enhanced luminescence intensity and quantum yield at room temperature. Lower temperature (4 °C) increased the time of bacterial luminescence and revealed a stage of bioluminescence inhibition after 150 h of bioluminescence registration start. The role of conditions of exposure the bacterial cells to the (241)Am is discussed. The effect of (241)Am on luminous bacteria was attributed to peroxide compounds generated in water solutions as secondary products of radioactive decay. Increase of peroxide concentration in (241)Am solutions was demonstrated; and the similarity of (241)Am and hydrogen peroxide effects on bacterial luminescence was revealed. The study provides a scientific basis for elaboration of bioluminescence-based assay to monitor radiotoxicity of alpha-emitting radionuclides in aquatic solutions. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. [Status of the lipid peroxidation system in the tissues of rats following a 7-day flight on the Kosmos-1667 biosatellite].

    PubMed

    Delenian, N V; Markin, A A

    1989-01-01

    Rats flown for 7 days on Cosmos-1667 were for the first time used to measure antioxidative enzymes (superoxide dismutase, glutathione peroxidase, glutathione reductase, catalase), lipid peroxidation products (diene conjugates, malonic dialdehyde, Schiff bases) and tocopherol. Enhanced lipid peroxidation in the heart was completely compensated by activation of antioxidative enzymes. The content of all lipid peroxidation products measured in the liver increased; this was accompanied by a decrease of glutathione peroxidase and an increase of superoxide dismutase activities. It is suggested that lipid peroxidation was activated in response to altered gravity.

  6. Occurrence of Metastudtite (Uranium Peroxide Dihydrate) at a FUSRAP Site

    SciTech Connect

    Young, C.M.; Nelson, K.A.; Stevens, G.T.

    2006-07-01

    Uranium concentrations in groundwater in a localized area of a site exceed the USEPA Maximum Contaminant Level (MCL) by a factor of one thousand. Although the groundwater seepage velocity ranges up to 0.7 meters per day (m/day), data indicate that the uranium is not migrating in groundwater. We believe that the uranium is not mobile because of local geochemical conditions and the unstable nature of the uranium compound present at the site; uranium peroxide dihydrate (metastudtite). Metastudtite [UO{sub 4}.2(H{sub 2}O) or (U(O{sub 2})|O|(OH){sub 2}).3H{sub 2}O] has been identified at other sites as an alteration product in casks of spent nuclearmore » fuel, but neither enriched nor depleted uranium were present at this site. Metastudtite was first identified as a natural mineral in 1983, although documented occurrences in the environment are uncommon. The U.S. Army Corps of Engineers (USACE) is conducting a remedial investigation at the DuPont Chambers Works in Deep water New Jersey under the Formerly Utilized Sites Remedial Action Program (FUSRAP) to evaluate radioactive contamination resulting from historical activities conducted in support of Manhattan Engineering District operations. From 1942 to 1947, Chambers Works converted uranium oxides to uranium tetrafluoride and uranium metal. More than half of the production at this facility resulted from the recovery process, where uranium-bearing dross and scrap were reacted with hydrogen peroxide to produce uranium peroxide dihydrate. The 280-hectare Chambers Works has produced some 600 products, including petrochemicals, aromatics, fluoro-chemicals, polymers, and elastomers. Contaminants resulting from these processes, including separate-phase petrochemicals, have also been detected within the boundaries of the FUSRAP investigation. USACE initiated remedial investigation field activities in 2002. The radionuclides of concern are natural uranium (U{sub nat}) and its short-lived progeny. Areas of impacted soil

  7. 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.

  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. Water disinfection with the hydrogen peroxide-ascorbic acid-copper (II) system.

    PubMed Central

    Ragab-Depre, N J

    1982-01-01

    Treatment of secondary effluents with hydrogen peroxide (10 mg/liter)-ascorbic acid (10 mg/liter)-Cu2+ (0.5 mg/liter) for 60 min resulted in around 99% reduction of the initial plate count. Hydrogen peroxide could be replaced by other peroxygen compounds; ascorbic acid could be replaced by other reducing agents, of which sodium sulfite and ethanol were the most effective. Cu2+, however, could not be replaced by other metal ions without loss of bactericidal efficiency of the ternary combination. Enterobacteriaceae, total and fecal coliforms, staphylococci, and micrococci were reduced by 99.0 to 99.9%. Group D streptococci aerobic spores were reduced by 80 and 15%, respectively. Clostridium perfringens, yeasts, and molds were not killed by the disinfectant combinations. The effect of pH was only minor in the range from 6 to 7.5. At a higher pH value the bactericidal effects tended to decrease. The hydrogen peroxide-ascorbic acid-Cu2+ combination made it possible to obtain 99% reduction within 30 min. When using the hydrogen peroxide-sodium sulfite-Cu2+ or the hydrogen peroxide-ethanol-Cu2+ combinations, 60 min of contact time was necessary to obtain 99% reduction of the initial plate count. Cu2+ combined to an intermediate product of the ascorbic acid autoxidation is the toxic agent, and its penetration into the cell is promoted by hydrogen peroxide. PMID:7138000

  10. Safe handling of potential peroxide forming compounds and their corresponding peroxide yielded derivatives.

    SciTech Connect

    Sears, Jeremiah Matthew; Boyle, Timothy J.; Dean, Christopher J.

    2013-06-01

    This report addresses recent developments concerning the identification and handling of potential peroxide forming (PPF) and peroxide yielded derivative (PYD) chemicals. PPF chemicals are described in terms of labeling, shelf lives, and safe handling requirements as required at SNL. The general peroxide chemistry concerning formation, prevention, and identification is cursorily presented to give some perspective to the generation of peroxides. The procedure for determining peroxide concentrations and the proper disposal methods established by the Hazardous Waste Handling Facility are also provided. Techniques such as neutralization and dilution are provided for the safe handling of any PYD chemicals to allow formore » safe handling. The appendices are a collection of all available SNL documentation pertaining to PPF/PYD chemicals to serve as a single reference.« less

  11. Safe handling of potential peroxide forming compounds and their corresponding peroxide yielded derivatives.

    SciTech Connect

    Sears, Jeremiah Matthew; Boyle, Timothy J.; Dean, Christopher J.

    2013-06-01

    This report addresses recent developments concerning the identification and handling of potential peroxide forming (PPF) and peroxide yielded derivative (PYD) chemicals. PPF chemicals are described in terms of labeling, shelf lives, and safe handling requirements as required at SNL. The general peroxide chemistry concerning formation, prevention, and identification is cursorily presented to give some perspective to the generation of peroxides. The procedure for determining peroxide concentrations and the proper disposal methods established by the Hazardous Waste Handling Facility are also provided. Techniques such as neutralization and dilution are provided for the safe handling of any PYD chemicals to allow for safe handling. The appendices are a collection of all available SNL documentation pertaining to PPF/PYD chemicals to serve as a single reference.

  12. Effects of cupric and ferric ions on in vitro lipid peroxidation of human serum

    SciTech Connect

    Dasgupta, A.; Peng, Y.; Zdunek, T.

    1991-03-15

    Transition metal ions especially ferric ions can catalytically generate free radicals by the Haber-Weiss reaction and initiate lipid peroxidation. Such processes may contribute to the mechanism of acute toxicity by transition metals. Serum pools were prepared from normal blood donors and incubated with 1mM cupric or ferric ions at 37C for 24h. Lipid peroxidation products were subsequently measured by 2-thiobarbituric acid assay as described by Yagi and the values were expressed as {mu}mol/L malonaldehyde equivalents. In another experiment, lipoproteins were coprecipitated with other proteins by 10% phosphotungstic acid/sulfuric acid and precipitates in aqueous suspension were incubated with 1 mM cupricmore » or ferric ions. When sera were incubated, the authors observed higher concentrations of lipid peroxidation products with cupric ions compared to samples supplemented with ferric ions. The mean value for peroxidation products in control group was 2.5 {mu}mol/L. However, the effect was reversed when protein precipitates were incubated in presence of such ions. Ferric ions also caused more peroxidation of linoleic acid and phosphatidylcholine isolated from egg yolk when compared to cupric ions. Such differential behavior may be attributed to different degree of chelation of ferric and cupric ions with serum proteins.« less

  13. 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.

  14. Erythromycin and Benzoyl Peroxide Topical

    MedlinePlus

    ... doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking. Be sure to mention other topical medications for acne. Your doctor may need to change the doses ...

  15. Hydrogen peroxide synthesis: an outlook beyond the anthraquinone process.

    PubMed

    Campos-Martin, Jose M; Blanco-Brieva, Gema; Fierro, Jose L G

    2006-10-27

    Hydrogen peroxide (H2O2) is widely used in almost all industrial areas, particularly in the chemical industry and environmental protection. The only degradation product of its use is water, and thus it has played a large role in environmentally friendly methods in the chemical industry. Hydrogen peroxide is produced on an industrial scale by the anthraquinone oxidation (AO) process. However, this process can hardly be considered a green method. It involves the sequential hydrogenation and oxidation of an alkylanthraquinone precursor dissolved in a mixture of organic solvents followed by liquid-liquid extraction to recover H2O2. The AO process is a multistep method that requires significant energy input and generates waste, which has a negative effect on its sustainability and production costs. The transport, storage, and handling of bulk H2O2 involve hazards and escalating expenses. Thus, novel, cleaner methods for the production of H2O2 are being explored. The direct synthesis of H2O2 from O2 and H2 using a variety of catalysts, and the factors influencing the formation and decomposition of H2O2 are examined in detail in this Review.

  16. 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.

  17. Enhancement of lipid peroxidation and its amelioration by vitamin E in a subject with mutations in the SBP2 gene.

    PubMed

    Saito, Yoshiro; Shichiri, Mototada; Hamajima, Takashi; Ishida, Noriko; Mita, Yuichiro; Nakao, Shohei; Hagihara, Yoshihisa; Yoshida, Yasukazu; Takahashi, Kazuhiko; Niki, Etsuo; Noguchi, Noriko

    2015-11-01

    Selenocysteine (Sec) insertion sequence-binding protein 2 (SBP2) is essential for the biosynthesis of Sec-containing proteins, termed selenoproteins. Subjects with mutations in the SBP2 gene have decreased levels of several selenoproteins, resulting in a complex phenotype. Selenoproteins play a significant role in antioxidative defense, and deficiencies in these proteins can lead to increased oxidative stress. However, lipid peroxidation and the effects of antioxidants in subjects with SBP2 gene mutations have not been studied. In the present study, we evaluated the lipid peroxidation products in the blood of a subject (the proband) with mutations in the SBP2 gene. We found that the proband had higher levels of free radical-mediated lipid peroxidation products, such as 7β-hydroxycholesterol, than the control subjects. Treatment of the proband with vitamin E (α-tocopherol acetate, 100 mg/day), a lipid-soluble antioxidant, for 2 years reduced lipid peroxidation product levels to those of control subjects. Withdrawal of vitamin E treatment for 7 months resulted in an increase in lipid peroxidation products. Collectively, these results clearly indicate that free radical-mediated oxidative stress is increased in the subject with SBP2 gene mutations and that vitamin E treatment effectively inhibits the generation of lipid peroxidation products. Copyright © 2015 by the American Society for Biochemistry and Molecular Biology, Inc.

  18. Lipid Peroxidation Markers in Coronary Artery Disease Patients with Possible Vascular Mild Cognitive Impairment.

    PubMed

    Suridjan, Ivonne; Herrmann, Nathan; Adibfar, Alex; Saleem, Mahwesh; Andreazza, Ana; Oh, Paul I; Lanctôt, Krista L

    2017-01-01

    This study examined associations between lipid peroxidation markers and cognition, and associations between these markers and cognitive response to an exercise intervention program, in adults with coronary artery disease at risk of dementia. Lipid peroxidation products were measured in serum in 118 patients (29 possible vascular mild cognitive impairment and 89 controls). Ratios of early- (lipid hydroperoxides, LPH) to late-stage (8-isoprostane, 8-ISO; 4-hydroxy-2-nonenal, 4-HNE) lipid peroxidation products were calculated. Cognitive performance was assessed before and at completion of a 24-week exercise intervention program. A global effect of group on lipid peroxidation markers was observed, adjusting for sex, years of education, and cardiopulmonary fitness (main effect of group F (3,102) = 2.957, p = 0.036). Lower lipid peroxidation at baseline, as determined by lower 8-ISO concentration, was associated with greater improvement in verbal memory (F (1, 64) = 4.738, p = 0.03) and executive function (F (1, 64) = 5.219, p = 0.026) performance. Similarly, higher ratios of 8-ISO/LPH (F (1, 65) = 6.592, p = 0.013) and (8-ISO+4-HNE) to LPH (F (1, 65) = 3.857, p = 0.054), were associated with less improvement in executive function performance over a 24-week exercise intervention. Lipid peroxidation may be a biomarker of early vascular cognitive impairment, and elevated lipid peroxidation might limit the cognitive benefits of exercise in this high-risk population.

  19. Lipid Peroxidation Markers in Coronary Artery Disease Patients with Possible Vascular Mild Cognitive Impairment

    PubMed Central

    Suridjan, Ivonne; Herrmann, Nathan; Adibfar, Alex; Saleem, Mahwesh; Andreazza, Ana; Oh, Paul I.; Lanctôt, Krista L.

    2017-01-01

    This study examined associations between lipid peroxidation markers and cognition, and associations between these markers and cognitive response to an exercise intervention program, in adults with coronary artery disease at risk of dementia. Lipid peroxidation products were measured in serum in 118 patients (29 possible vascular mild cognitive impairment and 89 controls). Ratios of early- (lipid hydroperoxides, LPH) to late-stage (8-isoprostane, 8-ISO; 4-hydroxy-2-nonenal, 4-HNE) lipid peroxidation products were calculated. Cognitive performance was assessed before and at completion of a 24-week exercise intervention program. A global effect of group on lipid peroxidation markers was observed, adjusting for sex, years of education, and cardiopulmonary fitness (main effect of group F (3,102) = 2.957, p = 0.036). Lower lipid peroxidation at baseline, as determined by lower 8-ISO concentration, was associated with greater improvement in verbal memory (F (1, 64) = 4.738, p = 0.03) and executive function (F (1, 64) = 5.219, p = 0.026) performance. Similarly, higher ratios of 8-ISO/LPH (F (1, 65) = 6.592, p = 0.013) and (8-ISO+4-HNE) to LPH (F (1, 65) = 3.857, p = 0.054), were associated with less improvement in executive function performance over a 24-week exercise intervention. Lipid peroxidation may be a biomarker of early vascular cognitive impairment, and elevated lipid peroxidation might limit the cognitive benefits of exercise in this high-risk population. PMID:28505971

  20. Ozonation and alkaline-peroxide pretreatment of wheat straw for Cryptococcus curvatus fermentation

    NASA Technical Reports Server (NTRS)

    Greenwalt, C. J.; Hunter, J. B.; Lin, S.; McKenzie, S.; Denvir, A.

    2000-01-01

    Crop residues in an Advanced Life Support System (ALS) contain many valuable components that could be recovered and used. Wheat is 60% inedible, with approximately 90% of the total sugars in the residue cellulose and hemicellulose. To release these sugars requires pretreatment followed by enzymatic hydrolysis. Cryptococcus curvatus, an oleaginous yeast, uses the sugars in cellulose and hemicellulose for growth and production of storage triglycerides. In this investigation, alkaline-peroxide and ozonation pretreatment methods were compared for their efficiency to release glucose and xylose to be used in the cultivation of C. curvatus. Leaching the biomass with water at 65 degrees C for 4 h prior to pretreatment facilitated saccharification. Alkaline-peroxide and ozone pretreatment were almost 100% and 80% saccharification efficient, respectively. The sugars derived from the hydrolysis of alkaline-peroxide-treated wheat straw supported the growth of C. curvatus and the production of edible single-cell oil.

  1. Ozonation and alkaline-peroxide pretreatment of wheat straw for Cryptococcus curvatus fermentation.

    PubMed

    Greenwalt, C J; Hunter, J B; Lin, S; McKenzie, S; Denvir, A

    2000-01-01

    Crop residues in an Advanced Life Support System (ALS) contain many valuable components that could be recovered and used. Wheat is 60% inedible, with approximately 90% of the total sugars in the residue cellulose and hemicellulose. To release these sugars requires pretreatment followed by enzymatic hydrolysis. Cryptococcus curvatus, an oleaginous yeast, uses the sugars in cellulose and hemicellulose for growth and production of storage triglycerides. In this investigation, alkaline-peroxide and ozonation pretreatment methods were compared for their efficiency to release glucose and xylose to be used in the cultivation of C. curvatus. Leaching the biomass with water at 65 degrees C for 4 h prior to pretreatment facilitated saccharification. Alkaline-peroxide and ozone pretreatment were almost 100% and 80% saccharification efficient, respectively. The sugars derived from the hydrolysis of alkaline-peroxide-treated wheat straw supported the growth of C. curvatus and the production of edible single-cell oil.

  2. Peroxide as a Novel Treatment for Ecchymoses

    PubMed Central

    Sroa, Novie; Campbell, Shannon M.; Bechtel, Mark A.; Mitch Opremcak, E.

    2010-01-01

    Ecchymoses, commonly known as bruises, frequently occur after injury to the skin causes extravasation of red blood cells into interstitial tissue. This extravasation can lead to an inflammatory cascade. The case report presented details one patient who displayed rapid improvement in the pain and appearance of a partially treated bruise on her thigh after an eight-hour application of hydrogen peroxide 15% carbamide gel under occlusion. Hydrogen peroxide 15% carbamide gel may represent a novel treatment for ecchymoses. This potential new treatment for bruises needs to be studied further to detail its adverse effects, safety profile, and efficacy profile. PMID:21103315

  3. Thermal Ignition of Detonable Hydrogen Peroxide Compositions

    NASA Astrophysics Data System (ADS)

    Zucker, J. M.; Tappan, B. C.; Lloyd, J. M.; Foley, T. J.

    2009-12-01

    Hydrogen peroxide can be mixed with a variety of fuels to produce detonable compositions. These compositions can be thermally unstable and their behavior can be difficult to predict. Furthermore, the addition of some acids to the mixture could increase its sensitivity. Presented here are the outcomes of cookoff experiments performed on hydrogen peroxide and fuels compositions, as well as an acid-sensitized mixture. Soak temperatures of 88° C, 84° C and 82° C were used, with reaction times of 3010 seconds, 3560 seconds and 3230 seconds, accordingly. The acid-sensitized experiment, when soaked at 82° C, reacted after just 2450 seconds.

  4. 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.

  5. Effect of the reaction conditions on the performance of Au-Pd/TiO(2) catalyst for the direct synthesis of hydrogen peroxide.

    PubMed

    Piccinini, Marco; Ntainjua, Edwin; Edwards, Jennifer K; Carley, Albert F; Moulijn, Jacob A; Hutchings, Graham J

    2010-03-14

    The direct synthesis of hydrogen peroxide from H(2) and O(2) has been studied using a high activity AuPd/TiO(2) catalyst. In particular, the effect of variation in the reaction conditions on the productivity of hydrogen peroxide formation is investigated in detail. The effect of H(2)/O(2) molar ratio, temperature, total pressure and solvent composition has been studied and optimised conditions identified. In addition, the effect of carrying out the synthesis reaction in the presence of hydrogen peroxide is investigated and the competing reactions of hydrogen peroxide formation, decomposition and hydrogenation are discussed and optimal operating conditions are identified.

  6. Investigation of flavonoid influence on peroxidation processes intensity in the blood

    NASA Astrophysics Data System (ADS)

    Navolokin, N. A.; Mudrak, D. A.; Plastun, I. L.; Bucharskaya, A. B.; Agandeeva, K. E.; Ivlichev, A. V.; Tychina, S. A.; Afanasyeva, G. A.; Polukonova, N. V.; Maslyakova, G. N.

    2017-03-01

    Influence of flavonoids on the intensity of peroxidation processes in the blood is investigated by numerical modeling and by experiment in vivo. As an example we consider the effects of flavonoid-containing extract of Helichrysum arenarium L. with antitumor activity on serum of rats with transplanted liver cancer PC-1. It was found that the content of malondialdehyde, lipid hydroperoxides and average mass molecules were decreased in animals with transplanted liver cancer after intramuscular and oral administration of Helichrysum arenarium L extract in a dose of 1000 mg/mL. The extract reduces the intensity of lipid peroxidation processes in animals. The compound formation possibility of flavonoids and products of lipid peroxidation is investigated by numerical simulations. Using the density functional theory method of molecular modeling, we analyze hydrogen bonds formation and their influence on IR - spectra and structure of molecular complex which is formed due to interaction between flavonoids and products of lipid peroxidation processes on example of naringine and malondialdehyde. We have found that naringine can form a steady molecular complex with malondialdehyde by hydrogen bonds formation. Thus, the application of Helichrysum arenarium L. extract for suppression processes of lipid peroxidation and activation of enzymatic and non-enzymatic antioxidant systems is promising.

  7. The hydrogen peroxide impact on larval settlement and metamorphosis of abalone Haliotis diversicolor supertexta

    NASA Astrophysics Data System (ADS)

    Zhang, Xiangjing; Yang, Zhihui; Cai, Zhonghua

    2008-08-01

    Abalone Haliotis diversicolor supertexta is an important economic mollusk. The settlement and metamorphosis are two critical stages during its development period, which has direct influence on abalone survival and production. The influence of reactive oxygen species (hydrogen peroxide) on abalone embryo and juvenile development were examined in this study. Larvae of Haliotis diversicolor supertexta were induced to settlement and metamorphose by exposure to seawater supplemented with hydrogen peroxide. They had the best performance at 800 μmol/L. The concentration of 1 000 μmol/L or higher was toxic to the larvae, as the larvae could settle down only at benthic diatom plates without complete metamorphosis. In addition, H2O2 adding time was critical to the larval performance. 24h after two-day post-fertilization was proved to be the optimal adding time. In this paper, two action mechanisms of hydrogen peroxide are discussed: (1) hydrogen peroxide has direct toxicity to ciliated cells, thus cause apoptosis; (2) hydrogen peroxide, as a product from catecholamines’ autoxidation process in vivo, can reverse this process to produce neuro-transmitters to induce abalone metamorphosis.

  8. The influence of Ambroxol on peroxidative processes in lung and plasma in dogs after pulmonectomy.

    PubMed

    Jabłonka, S; Ledwozyw, A; Kadziołka, W; Jabłonka, A; Nestorowicz, A

    1992-01-01

    The purpose of the studies was to determine the effect of Ambroxol on the activity of antioxidant enzymes and on the glutathione level as well as the intensity of the peroxidative processes in the lung tissue, alveolar macrophages and plasma in dogs after unilateral pulmonectomy. On the 2nd and 6th day after the surgery the activity of antioxidant enzymes and the glutathione level were studied in the remaining lung. The levels of the lipid peroxidation products were determined in the analogous system. In both examined groups the increase in the antioxidant enzyme activity and the lipid peroxidation product levels was observed in the remaining lung after the surgery. In Ambroxol-treated animals the statistically significant increase in the antioxidant enzyme activity was noted while the intensity of peroxidative processes was found to be lower. This fact may suggest that Ambroxol stimulates the resistance of the lung tissue to the free radical activity and inhibits the lung peroxidative processes in dogs after pulmonectomy.

  9. Photochemical formation of peroxides and fluorescence characteristics of the water-soluble fraction of bulk aerosols collected in Okinawa, Japan

    NASA Astrophysics Data System (ADS)

    Nakajima, Hitomi; Okada, Kouichirou; Kuroki, Yukiko; Nakama, Yoshihide; Handa, Daishi; Arakaki, Takemitsu; Tanahara, Akira

    Photochemical reactions of dissolved organic compounds, fluorescent dissolved organic matter (FDOM) in particular, are implicated as an important source of peroxides, but their contribution to overall peroxide formation is not well understood. We studied the photochemical formation of peroxides (hydrogen peroxide and organic peroxides), together with changes in fluorescent properties of water-soluble fraction (WSF) solutions of bulk aerosols ( n=28) collected in Okinawa, Japan. Monochromatic wavelengths of 313, 334, 366, and 405 nm were used to examine the samples, and the changes in peroxide concentrations and fluorescence intensities (FIs) during these illuminations were measured. For many samples, two peaks of fluorescence were found in the WSF solutions at excitation/emission wavelengths (Ex/Em) of 250-275/375-455 and 300-320/400-440 nm, which can be signatures for fulvic acid-like compounds. Several samples collected between November and April (winter samples) showed another fluorescence peak at 260-290/305-345 nm, which could be due to the presence of aromatic amines. As illumination time increased, the peroxide concentrations increased and the FI changed, but not uniformly. The FI and peroxide photo-production rates were only weakly correlated ( R<0.36), and the correlation between FI and dissolved organic carbon (DOC) concentrations was also weak ( R<0.75). These results suggest that the photochemistry of FDOM may not comprise a dominant pathway to form peroxides in the WSF solutions, but that peroxides are formed as a result of complex processes in the WSF solutions of aerosols collected in Okinawa.

  10. Efficacy of Mouthwashes Containing Hydrogen Peroxide on Tooth Whitening

    PubMed Central

    Karadas, Muhammet; Hatipoglu, Omer

    2015-01-01

    The aim of this study was to analyze the efficacy of mouthwashes containing hydrogen peroxide compared with 10% carbamide peroxide (CP) gel. Fifty enamel-dentin samples were obtained from bovine incisors and then stained in a tea solution. The stained samples were randomly divided into five groups according to the whitening product applied (n = 10): AS: no whitening (negative control), with the samples stored in artificial saliva; CR: Crest 3D White mouthwash; LS: Listerine Whitening mouthwash; SC: Scope White mouthwash; and OP group: 10% CP Opalescence PF (positive control). Color measurements were carried out with a spectrophotometer before staining, after staining, and on the 7th, 28th, and 56th day of the whitening period. The data were analyzed using two-way analysis of variance followed by a Tukey post hoc test. The color change (ΔE) was significantly greater in all the groups compared to that of the AS group. After 56 days, no significant differences were found among the mouthwash products with respect to color change (P > 0.05). The whiteness of the teeth treated with the mouthwashes increased significantly over time. Nevertheless, the color change achieved with the mouthwashes was significantly lower than that achieved with the 10% CP at-home bleaching gel. PMID:26295061

  11. Transient release of lipid peroxides after coronary artery balloon angioplasty.

    PubMed

    Roberts, M J; Young, I S; Trouton, T G; Trimble, E R; Khan, M M; Webb, S W; Wilson, C M; Patterson, G C; Adgey, A A

    1990-07-21

    Free radical production may cause myocardial damage during reperfusion of ischaemic myocardial tissue; when free radicals interact with polyunsaturated fatty acids or their esters, lipid peroxides are produced. A product of lipid peroxidation, malondialdehyde, was measured in 10 subjects with stable angina who underwent angioplasty of a proximal high-grade stenosis (over 90%) of the left anterior descending coronary artery. In all subjects the duration of balloon occlusion was 60 s. Blood was withdrawn from the great cardiac vein immediately before balloon inflation (T0), immediately after balloon deflation (T60), 15 s after balloon deflation (T75), and 1 min after balloon deflation (T120). There was a significant increase in malondialdehyde at T60 compared with T0 for the first balloon inflation (mean increase 0.3 mumol/l [95% confidence limits 0.1, 0.5]), and at both T60 (0.31 mumol/l [0.15, 0.47]) and T75 (0.22 mumol/l [0.04, 0.40]) for the second balloon inflation. This model could be used to assess antioxidant effects of drugs.

  12. Kinetics of lithium peroxide monohydrate thermal decomposition

    NASA Astrophysics Data System (ADS)

    Nefedov, Roman; Posternak, Nikolay; Ferapontov, Yuriy

    2017-11-01

    Topochemical dehydration of lithium peroxide was studied to determine kinetic parameters at the range of temperatures from 90°C to 147°C in non-isothermal conditions by derivatographic method. The study was conducted to select optimal conditions of lithium peroxide synthesis in dehydration reaction of triple LiOH-H2O2-H2O system in ultra-high frequency radiation field. Conditions of dehydration reaction were caused by the thermal conductivity of LiOH -H2O2-H2O system. It is determined that dehydration process runs close to the first order reaction (n=0.85±0.03). The activation energy and pre-exponential factor values were found as Eak = 86.0 ± 0.8 kJ/mol, k0 = (2.19 ± 0.16) .1011 min-1, correspondingly. It is supposed that there is a similarity between the dehydration mechanism of lithium peroxide monohydrate and peroxide hydrates of alkaline-earth metals (calcium, barium and strontium).

  13. Surface cross-linked UHMWPE using peroxides.

    PubMed

    Gul, Rizwan M; Fung, Katharina; Doshi, Brinda N; Oral, Ebru; Muratoglu, Orhun K

    2017-11-01

    Crosslinking of ultra-high molecular weight polyethylene (UHMWPE) has been successfully used to improve its wear performance. Wear is a surface phenomenon and limiting crosslinking to a layer only on the surface is desirable, as crosslinking of the bulk of the implant reduces its mechanical strength and toughness. We present a novel technique to surface crosslink consolidated UHMWPE/vitamin-E blends by diffusing an organic peroxide into the polymer at moderate temperatures, followed by heating to above the peroxide decomposition temperature to cause crosslinking on the surface. We characterized the surface crosslink density and wear rate of surface crosslinked UHMWPE/vitamin-E blends with two different types of peroxides. Both peroxides resulted in surface crosslinking with an increase in wear resistance comparable to the state-of-the-art highly crosslinked UHMWPE used for orthopedic implants. The addition of the antioxidant vitamin-E led to higher oxidation resistance. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2551-2556, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  14. Efficacy of hydrogen peroxide in controlling mortality associated with saprolegniasis on walleye, white sucker, and paddlefish eggs

    USGS Publications Warehouse

    Gaikowski, M.P.; Rach, J.J.; Drobish, M.; Hamilton, J.; Harder, T.; Lee, L.A.; Moen, C.; Moore, A.

    2003-01-01

    The efficacy of hydrogen peroxide in controlling saprolegniasis on eggs of walleye Stizostedion vitreum, white sucker Catostomus commersoni, and paddlefish Polyodon spathula was evaluated at four private, state, and federal production hatcheries participating in an Investigational New Animal Drug efficacy study (experiment 1; walleyes) and in a laboratory-based miniature egg jar incubation system (experiment 2; walleyes, white suckers, and paddlefish). Naturally occurring fungal infestations (saprolegniasis) were observed on eggs in both experiments. Confirmatory diagnosis of infested eggs from one hatchery in experiment 1 identified the pathogen as Saprolegnia parasitica. During experiment 1, eggs were treated daily for 15 min with either 0, 500, or 750 mg/L of hydrogen peroxide, and one trial compared a 500-mg/L hydrogen peroxide treatment with a formalin treatment at 1,667 mg/L. Saprolegniasis infestation was observed in control egg jars, whereas treatment with either formalin or hydrogen peroxide virtually eliminated the infestation. Hydrogen peroxide treatments of 500 mg/L either increased egg hatch or were as effective as physical removal of infested eggs in controlling mortality. Although treatment with formalin at 1,667 mg/L significantly increased the percent eye-up of walleye eggs compared with that of those treated with hydrogen peroxide at 500 mg/L, the difference was only 1.9-2.6%. In experiment 2, noneyed eggs were treated for 15 min every other day with 0, 283, 565, or 1,130 mg/L of hydrogen peroxide until the viable eggs hatched. Saprolegniasis infestation engulfed most control eggs, whereas infestation of treated eggs was either reduced or not visible. Hydrogen peroxide significantly increased egg hatch for all three species tested in experiment 2. Although hydrogen peroxide treatments as low as 283 mg/L significantly increased walleye and white sucker hatch, treatments between 500 and 1,000 mg/L are more likely to be effective in production egg

  15. 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.

  16. Systems and methods for generation of hydrogen peroxide vapor

    SciTech Connect

    Love, Adam H; Eckels, Joel Del; Vu, Alexander K

    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 amore » 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.« less

  17. Induced lipid peroxidation in ram sperm: semen profile, DNA fragmentation and antioxidant status.

    PubMed

    Hamilton, Thais Rose dos Santos; de Castro, Letícia Signori; Delgado, Juliana de Carvalho; de Assis, Patrícia Monken; Siqueira, Adriano Felipe Perez; Mendes, Camilla Mota; Goissis, Marcelo Demarchi; Muiño-Blanco, Teresa; Cebrián-Pérez, José Álvaro; Nichi, Marcílio; Visintin, José Antonio; D'Ávila Assumpção, Mayra Elena Ortiz

    2016-04-01

    Action of reactive oxygen species, protamination failures and apoptosis are considered the most important etiologies of sperm DNA fragmentation. This study evaluated the effects of induced lipid peroxidation susceptibility on native semen profile and identified the mechanisms involved in sperm DNA fragmentation and testicular antioxidant defense on Santa Ines ram sperm samples. Semen was collected from 12 adult rams (Ovis aries) performed weekly over a 9-week period. Sperm analysis (motility, mass motility, abnormalities, membrane and acrosome status, mitochondrial potential, DNA fragmentation, lipid peroxidation and intracellular free radicals production); protamine deficiency; PRM1, TNP1 and TNP2 gene expression; and determination of glutathione peroxidase (GPx), glutathione reductase, catalase (CAT) and superoxide dismutase activity and immunodetection in seminal plasma were performed. Samples were distributed into four groups according to the sperm susceptibility to lipid peroxidation after induction with ascorbate and ferrous sulfate (low, medium, high and very high). The results were analyzed by GLM test and post hoc least significant difference. We observed an increase in native GPx activity and CAT immunodetection in groups with high susceptibility to induced lipid peroxidation. We also found an increase in total sperm defects, acrosome and membrane damages in the group with the highest susceptibility to induced lipid peroxidation. Additionally, the low mitochondrial membrane potential, susceptible to chromatin fragmentation and the PRM1 mRNA were increased in the group showing higher susceptibility to lipid peroxidation. Ram sperm susceptibility to lipid peroxidation may compromise sperm quality and interfere with the oxidative homeostasis by oxidative stress, which may be the main cause of chromatin damage in ram sperm. © 2016 Society for Reproduction and Fertility.

  18. Lipid peroxidation in cardiac surgery: towards consensus on biomonitoring, diagnostic tools and therapeutic implementation.

    PubMed

    Romano, Rosalba; Cristescu, Simona M; Risby, Terence H; Marczin, Nandor

    2017-11-06

    This review focuses on oxidative stress and more specifically lipid peroxidation in cardiac surgery, one of the fundamental theories of perioperative complications. We present the molecular pathways leading to lipid peroxidation and integrate analytical methods that allow detection of lipid peroxidation markers in the fluid phase with those focusing on volatile compounds in exhaled breath. In order to explore the accumulated data in the literature, we present a systematic review of quantitative analysis of malondialdehyde (MDA), a widely used lipid peroxidation product at various stages of cardiac surgery. This exploration reveals major limitations of existing studies in terms of variability of reported values and significant gaps due to discrete and variable sampling times during surgery. We also appraise methodologies that allow real time and continuous monitoring of oxidative stress. Complimentary techniques highlight that beyond the widely acclaimed contribution of the cardiopulmonary bypass technology and myocardial reperfusion injury, the use of diathermy contributes significantly to intraoperative lipid peroxidation. We conclude that there is an urgent need to implement the theory of oxidative stress towards a paradigm change in the clinical practice. Firstly, we need to acquire definite and irrefutable information on the link between lipid peroxidation and postoperative complications by building international consensus on best analytical approaches towards generating qualitatively and quantitatively comparable data sets in coordinated multicentre studies. Secondly, we should move away from routine low risk surgeries towards higher risk interventions where there is major unmet clinical need for improving patient journey and outcomes. There is also need for consensus on best therapeutic interventions which could be tested in convincing large scale clinical trials. As future directions, we propose combination of fluid phase platforms and "metabography" , an

  19. The Iodide-Catalyzed Decomposition of Hydrogen Peroxide: A Simple Computer-Interfaced Kinetics Experiment for General Chemistry

    NASA Astrophysics Data System (ADS)

    Hansen, John C.

    1996-08-01

    A kinetics experiment appropriate for use in a General Chemistry course is described. The reaction studied is the iodide-catalyzed decomposition of hydrogen peroxide. The rate of oxygen production is measured as a function of time using a computer-interfaced pressure transducer. The data are analyzed to determine the order of the reaction with respect to iodide and hydrogen peroxide concentrations and to determine the rate constant.

  20. Using hydrogen peroxide to prevent antibody disulfide bond reduction during manufacturing process.

    PubMed

    Du, Cheng; Huang, Yunping; Borwankar, Ameya; Tan, Zhijun; Cura, Anthony; Yee, Joon Chong; Singh, Nripen; Ludwig, Richard; Borys, Michael; Ghose, Sanchayita; Mussa, Nesredin; Li, Zheng Jian

    2018-01-16

    During large-scale monoclonal antibody manufacturing, disulfide bond reduction of antibodies, which results in generation of low molecule weight species, is occasionally observed. When this happens, the drug substance does not meet specifications. Many investigations have been conducted across the biopharmaceutical industry to identify the root causes, and multiple strategies have been proposed to mitigate the problem. The reduction is correlated with the release of cellular reducing components and depletion of dissolved oxygen before, during, and after harvest. Consequently, these factors can lead to disulfide reduction over long-duration storage at room temperature prior to Protein A chromatography. Several strategies have been developed to minimize antibody reduction, including chemical inhibition of reducing components, maintaining aeration before and after harvest, and chilling clarified harvest during holding. Here, we explore the use of hydrogen peroxide in clarified harvest bulk or cell culture fluid as a strategy to prevent disulfide reduction. A lab-scale study was performed to demonstrate the effectiveness of hydrogen peroxide in preventing antibody reduction using multiple IgG molecules. Studies were done to define the optimal concentration of hydrogen peroxide needed to avoid unnecessary oxidization of the antibody products. We show that adding a controlled amount of hydrogen peroxide does not change product quality attributes of the protein. Since hydrogen peroxide is soluble in aqueous solutions and decomposes into water and oxygen, there is no additional burden involved in removing it during the downstream purification steps. Due to its ease of use and minimal product impact, we demonstrate that hydrogen peroxide treatment is a powerful, simple tool to quench reducing potential by simply mixing it with harvested cell culture fluid.

  1. Expanding the crystal chemistry of uranyl peroxides: four hybrid uranyl-peroxide structures containing EDTA.

    PubMed

    Qiu, Jie; Ling, Jie; Sieradzki, Claire; Nguyen, Kevin; Wylie, Ernest M; Szymanowski, Jennifer E S; Burns, Peter C

    2014-11-17

    The first four uranyl peroxide compounds containing ethylenediaminetetra-acetate (EDTA) were synthesized and characterized from aqueous uranyl peroxide nitrate solutions with a pH range of 5-7. Raman spectra demonstrated that reaction solutions that crystallized [NaK15[(UO2)8(O2)8(C10H12O10N2)2(C2O4)4]·(H2O)14] (1) and [Li4K6[(UO2)8(O2)6(C10H12O10N2)2(NO3)6]·(H2O)26] (2) contained excess peroxide, and their structures contained oxidized ethylenediaminetetraacetate, EDTAO2(4-). The solutions from which [K4[(UO2)4(O2)2(C10H13O8N2)2(IO3)2]·(H2O)16] (3) and LiK3[(UO2)4(O2)2(C10H12O8N2)2(H2O)2]·(H2O)18 (4) crystallized contained no free peroxide, and the structures incorporated intact EDTA(4-). In contrast to the large family of uranyl peroxide cage clusters, coordination of uranyl peroxide units in 1-4 by EDTA(4-) or EDTAO2(4-) results in isolated tetramers or dimers of uranyl ions that are bridged by bidentate peroxide groups. Two tetramers are bridged by EDTAO2(4-) to form octamers in 1 and 2, and dimers of uranyl polyhedra are linked through iodate groups in 3 and EDTA(4-) in 4, forming chains in both cases. In each structure the U-O2-U dihedral angle is strongly bent, at ∼140°, consistent with the configuration of this linkage in cage clusters and other recently reported uranyl peroxides.

  2. Synthesis and asymmetric resolution of α-azido-peroxides.

    PubMed

    Pramanik, Suman; Ghorai, Prasanta

    2013-08-02

    An unprecedented synthesis of α-azido-peroxides has been developed using an FeCl3-catalyst starting from carbonyl, TMS-azide, and hydroperoxide. Further, a base promoted decomposition of synthesized secondary α-azido-peroxides to provide the corresponding tert-butyl esters has been disclosed. Finally, an asymmetric kinetic resolution of such α-azido-peroxides has also been developed to provide chiral α-azido-peroxides in excellent enantiopurity.

  3. Hydrogen and oxygen isotope values in hydrogen peroxide.

    PubMed

    Barnette, Janet E; Lott, Michael J; Howa, John D; Podlesak, David W; Ehleringer, James R

    2011-05-30

    Hydrogen peroxide (H(2)O(2)) is a widely used oxidizer with many commercial applications; unfortunately, it also has terrorist-related uses. We analyzed 97 hydrogen peroxide solutions representing four grades purchased across the United States and in Mexico. As expected, the range of hydrogen (δ(2)H, 230‰) and oxygen (δ(18)O, 24‰) isotope values of the H(2)O(2) solutions was large, reflecting the broad isotopic range of dilution waters. This resulted in predictable linear relationships of δ(2)H and δ(18)O values of H(2)O(2) solutions that were near parallel to the Meteoric Water Line (MWL), offset by the concentration of H(2)O(2) in the solution. By grade, dilute (3 to 35%) H(2)O(2) solutions were not statistically different in slope. Although the δ(2)H values of manufactured H(2)O(2) could be different from those of water, rapid H(2)O(2)-H(2)O exchange of H atoms eliminated any distinct isotope signal. We developed a method to measure the δ(18)O value of H(2)O(2) independent of dilution water by directly measuring O(2) gas generated from a catalase-induced disproportionation reaction. We predicted that the δ(18)O values of H(2)O(2) would be similar to that of atmospheric oxygen (+23.5‰), the predominant source of oxygen in the most common H(2)O(2) manufacturing process (median disproportionated δ(18)O=23.8‰). The predictable H-O relationships in H(2)O(2) solutions make it possible to distinguish commercial dilutions from clandestine concentration practices. Future applications of this work include synthesis studies that investigate the chemical link between H(2)O(2) reagents and peroxide-based explosive products, which may assist law enforcement in criminal investigations. Copyright © 2011 John Wiley & Sons, Ltd.

  4. Synthetic peroxides as potent antimalarials. News and views.

    PubMed

    Jefford, Charles W

    2012-01-01

    The present review describes the development of synthetic cyclic peroxides, which are designed to surpass the antimalarial activity of the lead molecule, the natural product (+)-artemisinin and some of its C10 derivatives. To begin with, tricyclic and bicyclic 1,2,4-trioxanes are taken to show how the pharmacophore was identified and chirality proved to be irrelevant. The action of ferrous salts on trioxanes illustrates the structural elements that are needed so that reductive breaking of the peroxide bond leads to C-centered radicals, the alleged parasiticidal agents. Views are expressed on how heme, Plasmodium SERCA, and plain ferrous ions, either as targets or activators, could be implicated in the mode of action. Thereafter, news about 1,2,4-trioxolanes, 1,2,4-trioxanes, 1,2,4,5-tetraoxanes, 1,2-dioxolanes, and 1,2-dioxanes is recounted, emphasizing aspects of design, mechanism, and the importance of the adamantane entity for buttressing activity. News about compounds made up of a trioxane covalently bound to aminoquinoline, so-called hybrid molecules, is reported together with a view that they might be better than mechanical mixtures. No new antimalarial can be considered without a word about the risk posed by the parasite developing resistance. The review is not intended to be exhaustive. Some gaps prior to 2009 are filled in, while the later literature up to the end of July 2011 has been covered. Artemisinin and its derivatives fall outside the scope of the review. Nevertheless, some mechanistic insights garnered from artemisinin, which are relevant to synthetic peroxides, are included.

  5. Noninvasive assessment of peroxidative lung damage by HIPDM lung scanning

    SciTech Connect

    Miniati, M.; Borrelli, E.; Monti, S.; Cocci, F.; Solfanelli, S.; Giani, L.; Pistolesi, M. Univ. of Siena, )

    1991-03-15

    The basic compound iodobenzyl-propanediamine (HIPDM), when given intravenously, is extracted by the lungs whence it is effluxed at a slow exponential rate. In humans (normal non smokers), the mean residence time ({bar t}) of 123I-HIPDM, assessed by external detection, averages 7.2 {plus minus} 1.1 hrs. Persistence of HIPDM in lungs is significantly increased in asymptomatic smokers and, to a greater extent, in patients with ARDS. Since production of free oxygen radicals reportedly occurs as a consequence of smoke exposure and in the course of acute lung injury, the authors hypothesized that the prolonged persistence of HIPDM in the lungs of smokers and of patients with ARDS might reflect a peroxidative damage of lung tissue. They tested this hypothesis in rabbits since their baseline HIPDM lung clearance is similar to that of nonsmoking humans. In rabbits, acute lung injury was induced by phorbol myristate acetate. Three hrs after PMA administration, the animals received an i.v. bolus of {sup 131}I-HIPDM. Radioactivity over the chest was recorded for 2 hrs by gamma camera and HIPDM mean residence time in the lungs was computed. Thereafter, the animals were sacrificed and their lungs were removed to measure wet/dry weight ratio as index of lung edema and malondialdehyde (MDA) content as index of lipid peroxidation. HIPDM mean residence time was positively correlated with MDA level in lung tissue, but not with wet/dry weight ratio. Noninvasive assessment of HIPDM lung kinetics may then serve as specific in vivo marker of peroxidative lung injury.

  6. Strategies for designing supported gold-palladium bimetallic catalysts for the direct synthesis of hydrogen peroxide.

    PubMed

    Edwards, Jennifer K; Freakley, Simon J; Carley, Albert F; Kiely, Christopher J; Hutchings, Graham J

    2014-03-18

    Hydrogen peroxide is a widely used chemical but is not very efficient to make in smaller than industrial scale. It is an important commodity chemical used for bleaching, disinfection, and chemical manufacture. At present, manufacturers use an indirect process in which anthraquinones are sequentially hydrogenated and oxidized in a manner that hydrogen and oxygen are never mixed. However, this process is only economic at a very large scale producing a concentrated product. For many years, the identification of a direct process has been a research goal because it could operate at the point of need, producing hydrogen peroxide at the required concentration for its applications. Research on this topic has been ongoing for about 100 years. Until the last 10 years, catalyst design was solely directed at using supported palladium nanoparticles. These catalysts require the use of bromide and acid to arrest peroxide decomposition, since palladium is a very active catalyst for hydrogen peroxide hydrogenation. Recently, chemists have shown that supported gold nanoparticles are active when gold is alloyed with palladium because this leads to a significant synergistic enhancement in activity and importantly selectivity. Crucially, bimetallic gold-based catalysts do not require the addition of bromide and acids, but with carbon dioxide as a diluent its solubility in the reaction media acts as an in situ acid promoter, which represents a greener approach for peroxide synthesis. The gold catalysts can operate under intrinsically safe conditions using dilute hydrogen and oxygen, yet these catalysts are so active that they can generate peroxide at commercially significant rates. The major problem associated with the direct synthesis of hydrogen peroxide concerns the selectivity of hydrogen usage, since in the indirect process this factor has been finely tuned over decades of operation. In this Account, we discuss how the gold-palladium bimetallic catalysts have active sites for the

  7. Catalytic oxidative cleavage of olefins promoted by osmium tetroxide and hydrogen peroxide.

    PubMed

    Hart, Stewart R; Whitehead, Daniel C; Travis, Benjamin R; Borhan, Babak

    2011-07-07

    Hydrogen peroxide was employed as the terminal oxidant in the osmium tetroxide mediated oxidative cleavage of olefins, producing the corresponding aldehyde and ketone products. Aryl olefins are cleaved in good to excellent yield regardless of arene electronics. Alkyl olefins cleave in moderate to good yield for di- and tri-substituted alkenes.

  8. Effective oxidation of sulfides to sulfoxides with hydrogen peroxide under transition-metal-free conditions.

    PubMed

    Golchoubian, Hamid; Hosseinpoor, Farideh

    2007-03-03

    A "green" highly selective oxidation of organic sulfides to the corresponding sulfoxides was developed using hydrogen peroxide and glacial acetic acid under transition metal-free and mild conditions. The oxidation procedure is very simple and the products are easily isolated in excellent yields (90-99%).

  9. CATALYTIC OXIDATION OF ALCOHOLS AND EPOXIDATION OF OLEFINS WITH HYDROGEN PEROXIDE AS OXIDANT

    EPA Science Inventory

    Hydrogen peroxide (H2O2) is an ideal oxidant of choice for these oxidations due to economic and environmental reasons by giving water as a by-product. Two catalysts used are vanadium phosphorus oxide (VPO) and Fe3+/montmorillonite-K10 catalyst prepared by ion-exchange method at a...

  10. The Feasibility of Using Hydrogen Peroxide Decomposition Studies for High School Chemistry.

    ERIC Educational Resources Information Center

    Carter, Gillian E.

    1986-01-01

    Highlights difficulties that occur when teachers attempt to devise new experiments (use of hydrogen peroxide decomposition) and how seemingly useless results can be turned into productive student projects. Considers effects of ions present in tap water, pH, dust, and nature of vessel's surface. Reaction order and safety precautions are noted. (JN)

  11. 49 CFR 172.427 - ORGANIC PEROXIDE label.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false ORGANIC PEROXIDE label. 172.427 Section 172.427... SECURITY PLANS Labeling § 172.427 ORGANIC PEROXIDE label. (a) Except for size and color, the ORGANIC PEROXIDE label must be as follows: ER29DE06.000 (b) In addition to complying with § 172.407, the background...

  12. 49 CFR 172.552 - ORGANIC PEROXIDE placard.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false ORGANIC PEROXIDE placard. 172.552 Section 172.552... SECURITY PLANS Placarding § 172.552 ORGANIC PEROXIDE placard. (a) Except for size and color, the ORGANIC PEROXIDE placard must be as follows: Er29de06.001 (b) In addition to complying with § 172.519, the...

  13. 49 CFR 172.552 - ORGANIC PEROXIDE placard.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false ORGANIC PEROXIDE placard. 172.552 Section 172.552... SECURITY PLANS Placarding § 172.552 ORGANIC PEROXIDE placard. (a) Except for size and color, the ORGANIC PEROXIDE placard must be as follows: Er29de06.001 (b) In addition to complying with § 172.519, the...

  14. 49 CFR 172.427 - ORGANIC PEROXIDE label.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false ORGANIC PEROXIDE label. 172.427 Section 172.427... SECURITY PLANS Labeling § 172.427 ORGANIC PEROXIDE label. (a) Except for size and color, the ORGANIC PEROXIDE label must be as follows: ER29DE06.000 (b) In addition to complying with § 172.407, the background...

  15. 49 CFR 172.427 - ORGANIC PEROXIDE label.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false ORGANIC PEROXIDE label. 172.427 Section 172.427... SECURITY PLANS Labeling § 172.427 ORGANIC PEROXIDE label. (a) Except for size and color, the ORGANIC PEROXIDE label must be as follows: ER29DE06.000 (b) In addition to complying with § 172.407, the background...

  16. 49 CFR 172.552 - ORGANIC PEROXIDE placard.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false ORGANIC PEROXIDE placard. 172.552 Section 172.552... SECURITY PLANS Placarding § 172.552 ORGANIC PEROXIDE placard. (a) Except for size and color, the ORGANIC PEROXIDE placard must be as follows: Er29de06.001 (b) In addition to complying with § 172.519, the...

  17. 49 CFR 172.552 - ORGANIC PEROXIDE placard.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false ORGANIC PEROXIDE placard. 172.552 Section 172.552... SECURITY PLANS Placarding § 172.552 ORGANIC PEROXIDE placard. (a) Except for size and color, the ORGANIC PEROXIDE placard must be as follows: Er29de06.001 (b) In addition to complying with § 172.519, the...

  18. 49 CFR 172.427 - ORGANIC PEROXIDE label.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false ORGANIC PEROXIDE label. 172.427 Section 172.427... SECURITY PLANS Labeling § 172.427 ORGANIC PEROXIDE label. (a) Except for size and color, the ORGANIC PEROXIDE label must be as follows: ER29DE06.000 (b) In addition to complying with § 172.407, the background...

  19. 49 CFR 172.427 - ORGANIC PEROXIDE label.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false ORGANIC PEROXIDE label. 172.427 Section 172.427... SECURITY PLANS Labeling § 172.427 ORGANIC PEROXIDE label. (a) Except for size and color, the ORGANIC... on the ORGANIC PEROXIDE label must be red in the top half and yellow in the lower half. [71 FR 78627...

  20. MEASUREMENT AND MODELING OF THE DRY DEPOSITION OF PEROXIDES

    EPA Science Inventory

    Measurements of the dry deposition velocity (Vd) of hydrogen peroxide (H2O2) and total organic peroxides (ROOH) were made during four experiments at three forested sites. Details and uncertainties associated with the measurement of peroxide...

  1. 21 CFR 178.1005 - Hydrogen peroxide solution.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... concentration specified therein. (d) Limitations. No use of hydrogen peroxide solution in the sterilization of... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Hydrogen peroxide solution. 178.1005 Section 178... SANITIZERS Substances Utilized To Control the Growth of Microorganisms § 178.1005 Hydrogen peroxide solution...

  2. 21 CFR 178.1005 - Hydrogen peroxide solution.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... concentration specified therein. (d) Limitations. No use of hydrogen peroxide solution in the sterilization of... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Hydrogen peroxide solution. 178.1005 Section 178... SANITIZERS Substances Utilized To Control the Growth of Microorganisms § 178.1005 Hydrogen peroxide solution...

  3. 21 CFR 178.1005 - Hydrogen peroxide solution.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

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

  4. 21 CFR 178.1005 - Hydrogen peroxide solution.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  5. Photosensitized Peroxidation of Lipids: An Experiment Using 1H-NMR

    NASA Astrophysics Data System (ADS)

    Smith, Marion W.; Brown, Renee; Smullin, Steven; Eager, Jon

    1997-12-01

    The photoperoxidation of methyl linoleate, using 5,10,15,20-tetraphenyl porphyrin as photosensitizer, was monitored by 60 MHz 1H-NMR. Samples were irradiated for 10-24 hours in front of a 15 W fluorescent light, and NMR signals in the 5-6 ppm and 10-11 ppm region of the spectrum indicated peroxidation products were formed. The absorption of oxygen from the air was measured by attaching the sample tube to a gas burette. When vitamin E was added to the mixture the extent of peroxidation was reduced, showing the protective effect of the antioxidant. These experiments are appropriate for students of biochemistry

  6. [Changes in the state of monooxygenase system and lipid peroxidation under the effects of carcinogenic dust].

    PubMed

    Kuz'mina, L P; Bezrukavnikova, L M; Arkhipova, O G; Kasparov, A A

    1997-01-01

    The work was aimed to study relationship of monooxygenase system and lipid peroxidation in experiments and in clinical group. The examinees were workers engaged into graphite ware production and exposed to low fibrogenic dust of coke and graphite with carcinogens (including 3,4-benzpyrene). The experimental data and examination materials prove the carcinogens to alter seriously those systems. Long stimulation of monooxygenase system and activation of lipid peroxidation could result in more intensive carcinogenic effects of polycyclic aromatic hydrocarbons being a component of coal pitch.

  7. The effect of hydrogen peroxide solution on SO2 removal in the semidry flue gas desulfurization process.

    PubMed

    Zhou, Yuegui; Zhu, Xian; Peng, Jun; Liu, Yaobin; Zhang, Dingwang; Zhang, Mingchuan

    2009-10-15

    The present study attempts to use hydrogen peroxide solution to humidify Ca(OH)(2) particles to enhance the absorption of SO(2) to achieve higher removal efficiency and to solve the valuable reuse of the reaction product in the semidry flue gas desulfurization (FGD) process. Experiments were carried out to examine the effect of various operating parameters including hydrogen peroxide solution concentration, Ca/S molar ratio and approach to adiabatic saturation temperature on SO(2) removal efficiency in a laboratory scale spray reactor. The product samples were analyzed to obtain semi-quantitative measures of mineralogical composition by X-ray diffraction (XRD) with reference intensity ratio (RIR) method and the morphology of the samples was examined by scanning electron microscope (SEM). Compared with spraying water to humidify Ca(OH)(2), SO(2) removal efficiency was improved significantly by spraying hydrogen peroxide solution of 1-3 wt.% to humidify Ca(OH)(2) because hydrogen peroxide solution enhanced the dissolution and absorption rate of SO(2). Moreover, XRD and SEM analyses show that the desulfurization products contain less amount of unreacted Ca(OH)(2) and more amount of stable calcium sulfate with increasing hydrogen peroxide solution concentration. Thus, the process mechanism of the enhanced absorption of SO(2) by spraying hydrogen peroxide solution to humidify Ca(OH)(2) was elucidated on the basis of the experimental results.

  8. Direct synthesis of hydrogen peroxide using in-situ selective layer

    NASA Astrophysics Data System (ADS)

    Makertihartha, I. G. B. N.; Dharmawijaya, P. T.; Zunita, M.; Wenten, I. G.

    2017-05-01

    Hydrogen peroxide is used in broad range of application such as oxidation, bleaching, and wastewater treatment. Conventionally, hydrogen peroxide is synthesized using reduction oxidation cycle of anthraquinones from hydrogen and oxygen. This process is rather complex and requires considerable amount of energy. Direct synthesis of hydrogen peroxide is one attractive approach to said problems. However, activity and selectivity is the main problem of direct synthesis since the reactants form explosive mixture. Dilution of gasses is commonly used to solve said problem but limit the amount of reactants in the liquid solvent. Membrane reactor can separate pure reactant gases and also constantly feed them over the length of reaction channel. Pd-Ag alloy membrane can be used both as a catalyst and hydrogen dosage. There are some studies that investigate the use of Pd based membrane reactor but still no commercial application. This paper will bring basic concept of Pd based membrane reactor for direct synthesis of hydrogen peroxide. Special attention will be given to current hurdles and their possible solutions that lead to facile production of hydrogen peroxide. Furthermore, recent trends towards utilization of micro reactor will also be discussed.

  9. Comparative effects of aripiprazole and selected antipsychotic drugs on lipid peroxidation in plasma.

    PubMed

    Dietrich-Muszalska, Anna; Kolińska-Łukaszuk, Jolanta

    2017-12-27

    The aim of the present study was to evaluate and compare the effects of a new antipsychotic aripiprazole, unique due to its mechanism of action, with the effects of selected antipsychotic drugs such as quetiapine, olanzapine, clozapine, risperidone and ziprasidone (at the final concentrations corresponding to clinically effective doses used for the treatment of acute episodes of schizophrenia) on lipid peroxidation in human plasma measured by the level of TBARS (thiobarbituric acid reactive substances), which is a marker of oxidative stress. The level of TBARS were measured spectrophotometrically, according to the modification of the Rice-Evans method. Our results indicate that antipsychotics at doses recommended for the treatment of acute episodes of schizophrenia may induce distinct changes in the levels of lipid peroxidation products (TBARS) in plasma. Aripiprazole had no effect on the level of a lipid peroxidation marker in plasma, although used at lower doses it showed insignificant prooxidative properties similar to clozapine. Quetiapine had the strongest antioxidant properties, contrary to prooxidative action of risperidone, ziprasidone or haloperidol, and clozapine at lower doses. Olanzapine reduced the level of TBARS in plasma only at a lower dose. Antipsychotics at doses recommended for the treatment of acute episode in schizophrenia may induce the distinct changes in plasma lipid peroxidation. Aripiprazole did not induce significant changes in plasma lipid peroxidation. In further studies, the role of oxidative stress in schizophrenic patients together with their clinical symptomatology and use of antipsychotics should be taken into account. This article is protected by copyright. All rights reserved.

  10. Transenamel and transdentinal penetration of hydrogen peroxide applied to cracked or microabrasioned enamel.

    PubMed

    Briso, A L F; Lima, A P B; Gonçalves, R S; Gallinari, M O; dos Santos, P H

    2014-01-01

    The present study evaluated transenamel and transdentinal penetration of hydrogen peroxide during tooth whitening recognized in altered enamel by the presence of cracks or microabrasion. We used 72 experimental units (n=20) obtained from bovine incisors: GI-sound enamel; GII-teeth showing visible enamel cracks (4 mm to 5.7 mm in length); and GIII-microabrasioned enamel. The 12 remaining specimens were used to analyze the enamel surface morphology using scanning electron microscopy. The specimens were cylindrical and 5.7 mm in diameter and 3.5 mm thick. A product based on 35% hydrogen peroxide was used for bleaching, following the manufacturer's recommendations for use. To quantify the H2O2 penetration, the specimens were placed in artificial pulp chambers containing an acetate buffer solution. After bleaching, the solution was collected and adequately proportioned with leucocrystal violet, peroxidase enzyme, and deionized water. The resulting solution was evaluated using ultraviolet visible reflectance spectrophotometer equipment. The data were analyzed by analysis of variance (ANOVA) and Fisher's PLSD at a significance level of 0.05, and significant differences in the penetration of peroxide in different substrate conditions were observed (p<0.0001). The penetration of hydrogen peroxide was more intense in cracked teeth. The group in which the enamel was microabraded showed intermediate values when compared to the control group. Microabrasion and the presence of cracks in the enamel make this substrate more susceptible to penetration of hydrogen peroxide during in-office whitening.

  11. Red fluorescent genetically encoded indicator for intracellular hydrogen peroxide

    NASA Astrophysics Data System (ADS)

    Ermakova, Yulia G.; Bilan, Dmitry S.; Matlashov, Mikhail E.; Mishina, Natalia M.; Markvicheva, Ksenia N.; Subach, Oksana M.; Subach, Fedor V.; Bogeski, Ivan; Hoth, Markus; Enikolopov, Grigori; Belousov, Vsevolod V.

    2014-10-01

    Reactive oxygen species (ROS) are conserved regulators of numerous cellular functions, and overproduction of ROS is a hallmark of various pathological processes. Genetically encoded fluorescent probes are unique tools to study ROS production in living systems of different scale and complexity. However, the currently available recombinant redox sensors have green emission, which overlaps with the spectra of many other probes. Expanding the spectral range of recombinant in vivo ROS probes would enable multiparametric in vivo ROS detection. Here we present the first genetically encoded red fluorescent sensor for hydrogen peroxide detection, HyPerRed. The performance of this sensor is similar to its green analogues. We demonstrate the utility of the sensor by tracing low concentrations of H2O2 produced in the cytoplasm of cultured cells upon growth factor stimulation. Moreover, using HyPerRed we detect local and transient H2O2 production in the mitochondrial matrix upon inhibition of the endoplasmic reticulum Ca2+ uptake.

  12. Hydrogen peroxide and the evolution of oxygenic photosynthesis

    NASA Technical Reports Server (NTRS)

    Mckay, C. P.; Hartman, H.

    1991-01-01

    Possible pathways for the evolution of oxygenic photosynthesis in the early reducing atmosphere of the earth are discussed. It is suggested that the abiotic production of atmospheric oxidants could have provided a mechanism by which locally oxidizing conditions were sustained within spatially confined habitats thus removing the available reductants and forcing photosynthetic organisms to utilize water (rather than ferrous or sulfide ions) as the electron donor. It is argued that atmospheric H2O2 played the key role in inducing oxygenic photosynthesis, because, as peroxide concentrations local environments increased, primitive organisms would not only be faced with a loss of a reductant, but would be also forced to develop a biochemical apparatus (such as catalase) that would protect them against the products of oxygenic photosynthesis. This scenario allows for the early evolution of oxygenic photosynthesis at the time when global conditions were still anaerobic.

  13. Sterilization of hydrogen peroxide resistant bacterial spores with stabilized chlorine dioxide.

    PubMed

    Friedline, Anthony; Zachariah, Malcolm; Middaugh, Amy; Heiser, Matt; Khanna, Neeraj; Vaishampayan, Parag; Rice, Charles V

    2015-01-01

    Bacillus pumilus SAFR-032 spores isolated from a clean room environment are known to exhibit enhanced resistance to peroxide, desiccation, UV radiation and chemical disinfection than other spore-forming bacteria. The survival of B. pumilus SAFR-032 spores to standard clean room sterilization practices requires development of more stringent disinfection agents. Here, we report the effects of a stabilized chlorine dioxide-based biocidal agent against spores of B. pumilus SAFR-032 and Bacillus subtilis ATCC 6051. Viability was determined via CFU measurement after exposure. Chlorine dioxide demonstrated efficacy towards sterilization of spores of B. pumilus SAFR-032 equivalent or better than exposure to hydrogen peroxide. These results indicate efficacy of chlorine dioxide delivered through a stabilized chlorine dioxide product as a means of sterilization of peroxide- and UV-resistant spores.

  14. Lipid peroxidation and antioxidant vitamin status in oral cavity and oropharyngeal cancer patients.

    PubMed

    Marakala, Vijaya; Malathi, M; Shivashankara, A R

    2012-01-01

    This study was conducted to determine levels of lipid peroxidation and antioxidant vitamin status in patients with oral cavity and oropharyngeal cancer. The study group consisted of a total number of 80 subjects between the age 40-68 years, 40 with clinically and histopathologically proved cases of oral cavity and oropharyngeal cancer and 40 normal healthy, age and sex matched volunteers as controls. Levels of lipid peroxidation products as malondialdehyde (MDA) and antioxidant vitamins as vitamin A and vitamin C were estimated and compared between the two groups. There was a statistical significant difference in the mean MDA, plasma vitamin A and vitamin C in the oral and oropharyngeal cancer patients compared with the healthy controls (p<0.0001). Lipid peroxidation (MDA) is higher and plasma antioxidant vitamins like vitamin A and vitamin C were lower in oral cavity and oropharyngeal cancer patients than healthy controls.

  15. Fluorescent Probes Used for Detection of Hydrogen Peroxide under Biological Conditions.

    PubMed

    Żamojć, Krzysztof; Zdrowowicz, Magdalena; Jacewicz, Dagmara; Wyrzykowski, Dariusz; Chmurzyński, Lech

    2016-05-03

    Hydrogen peroxide is a well-established precursor of reactive oxygen and nitrogen species that are known to contribute to oxidative stress-the crucial factor responsible for the course of a wide range of phy-sicochemical processes as well as the genesis of various diseases, such as cancer and neurodegenerative disorders. Thus, the development of sensitive and selective methods for the detection and quantitative determination of hydrogen peroxide is of great importance in monitoring the in vivo production of that species and elucidating its biological functions. This review highlights the progress that has been made in the development of fluorescent and luminescent probes (excluding nanoparticles) employed to monitor hydrogen peroxide under biological conditions. Attention was focused on probes developed in the past 10 years.

  16. Photopatternable and photoactive hydrogel for on-demand generation of hydrogen peroxide in cell culture.

    PubMed

    Garland, Shaun P; Wang, Royal Y; Raghunathan, Vijay Krishna; Lam, Kit S; Murphy, Christopher J; Russell, Paul; Sun, Gang; Pan, Tingrui

    2014-02-01

    Oxidative stress, largely mediated by reactive oxygen species (ROS), is a nearly ubiquitous component in complex biological processes such as aging and disease. Optimal in vitro methods used in elucidating disease mechanisms would deliver of low levels of hydrogen peroxide, emulating the in vivo pathological state, but current methods are limited by kinetic stability or accurate measurement of the dose administered. Here we present an in vitro platform that exploits anthraquinone catalysts for the photocatalytic production of hydrogen peroxide. This system can be dynamically tuned to provide constant generation of hydrogen peroxide at a desired physiologic rate over at least 14 days and is described using a kinetic model. Material characterization and stability is discussed along with a proof-of-concept in vitro study that assessed the viability of cells as they were oxidatively challenged over 24 h at different ROS generation rates. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Frost-weathering on Mars: experimental evidence for peroxide formation.

    PubMed

    Huguenin, R L; Miller, K J; Harwood, W S

    1979-12-01

    A laboratory study of the interaction of H2O frost with samples of the minerals olivine (Mg,Fe)2SiO4 and pyroxene (Mg,Fe)SiO3 at -11 degrees C to -22 degrees C revealed that an acidic oxidant was produced. Exposure of the frost-treated minerals to liquie H2O produced a sudden drop in pH and resulted in the production of copious O2(g) (as much as approximately 10(20) molecules g-1). Exposure of frost-treated samples to 5 ml of 0.1M HCOONa solution resulted in the rapid oxidation of up to 43% of the formate to CO2(g). These reactions were qualitatively similar to the chemical activity observed during the active cycles of the Viking lander Gas Exchange and Labeled Release Biology experiments. Attempts to identify the oxidant by chemical indicators were inconclusive, but they tentatively suggested that chemisorbed hydrogen peroxide may have formed. The formation of chemisorbed peroxide could be explained as a byproduct of the chemical reduction of the mineral. The following model was proposed. H+ was incorporated into the mineral from surface frost. This would have left behind a residual of excess OH-(ads) (relative to surface H+). Electrons were then stripped from the surface OH-(ads) (due to the large repulsive potential between neighboring OH-(ads)) and incorporated into the crystal to restore charge balance and produce a chemical reduction of the mineral. The resultant surface hydroxyl radicals could then have combined to form the more stable chemisorbed hydrogen peroxide species. While the chemisorbed peroxide should be relatively stable at low temperatures, it should tend to decay to O(ads)+ H2O(g) at higher temperatures with an activation energy of greater than or approximately 34 kcal mole-1. This is consistent with the long-term storage and sterilization behavior of the Viking soil oxidants. It is possible that as little as 0.1--1% frost-weathered material in the martian soil could have produced the unusual chemical activity that occurred during the Viking Gas

  18. Pro-oxidant activity of indicaxanthin from Opuntia ficus indica modulates arachidonate metabolism and prostaglandin synthesis through lipid peroxide production in LPS-stimulated RAW 264.7 macrophages.

    PubMed

    Allegra, M; D'Acquisto, F; Tesoriere, L; Attanzio, A; Livrea, M A

    2014-01-01

    Macrophages come across active prostaglandin (PG) metabolism during inflammation, shunting early production of pro-inflammatory towards anti-inflammatory mediators terminating the process. This work for the first time provides evidence that a phytochemical may modulate the arachidonate (AA) metabolism in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages, promoting the ultimate formation of anti-inflammatory cyclopentenone 15deoxy-PGJ2. Added 1 h before LPS, indicaxanthin from Opuntia Ficus Indica prevented activation of nuclear factor-κB (NF-κB) and over-expression of PGE2 synthase-1 (mPGES-1), but up-regulated cyclo-oxygenase-2 (COX-2) and PGD2 synthase (H-PGDS), with final production of the anti-inflammatory cyclopentenone. The effects were positively related with concentration between 50 and 100 µM. Indicaxanthin did not have any effect in the absence of LPS. A kinetic study investigating the redox status of LPS-stimulated macrophages between 0.5 and 12 h, either in the absence or in the presence of 50-100 µM indicaxanthin, revealed a differential control of ROS production, with early (0.5-3 h) modest inhibition, followed by a progressive (3-12 h) concentration-dependent enhancement over the level induced by LPS alone. In addition, indicaxanthin caused early (0.5-3 h) concentration-dependent elevation of conjugated diene lipid hydroperoxides, and production of hydroxynonenal-protein adducts, over the amount induced by LPS. In LPS-stimulated macrophages indicaxanthin did not affect PG metabolism when co-incubated with either an inhibitor of NADPH oxidase or vitamin E. It is concluded that LPS-induced pro-oxidant activity of indicaxanthin at the membrane level allows formation of signaling intermediates whose accumulation modulates PG biosynthetic pathway in inflamed macrophages.

  19. Pro-oxidant activity of indicaxanthin from Opuntia ficus indica modulates arachidonate metabolism and prostaglandin synthesis through lipid peroxide production in LPS-stimulated RAW 264.7 macrophages

    PubMed Central

    Allegra, M.; D’Acquisto, F.; Tesoriere, L.; Attanzio, A.; Livrea, M.A.

    2014-01-01

    Macrophages come across active prostaglandin (PG) metabolism during inflammation, shunting early production of pro-inflammatory towards anti-inflammatory mediators terminating the process. This work for the first time provides evidence that a phytochemical may modulate the arachidonate (AA) metabolism in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages, promoting the ultimate formation of anti-inflammatory cyclopentenone 15deoxy-PGJ2. Added 1 h before LPS, indicaxanthin from Opuntia Ficus Indica prevented activation of nuclear factor-κB (NF-κB) and over-expression of PGE2 synthase-1 (mPGES-1), but up-regulated cyclo-oxygenase-2 (COX-2) and PGD2 synthase (H-PGDS), with final production of the anti-inflammatory cyclopentenone. The effects were positively related with concentration between 50 and 100 µM. Indicaxanthin did not have any effect in the absence of LPS. A kinetic study investigating the redox status of LPS-stimulated macrophages between 0.5 and 12 h, either in the absence or in the presence of 50–100 µM indicaxanthin, revealed a differential control of ROS production, with early (0.5–3 h) modest inhibition, followed by a progressive (3–12 h) concentration-dependent enhancement over the level induced by LPS alone. In addition, indicaxanthin caused early (0.5–3 h) concentration-dependent elevation of conjugated diene lipid hydroperoxides, and production of hydroxynonenal-protein adducts, over the amount induced by LPS. In LPS-stimulated macrophages indicaxanthin did not affect PG metabolism when co-incubated with either an inhibitor of NADPH oxidase or vitamin E. It is concluded that LPS-induced pro-oxidant activity of indicaxanthin at the membrane level allows formation of signaling intermediates whose accumulation modulates PG biosynthetic pathway in inflamed macrophages. PMID:25180166

  20. Lipid peroxidation-induced VEGF expression in the skin of KKAy obese mice.

    PubMed

    Nakai, Kozo; Yoneda, Kozo; Ishihara, Yasuhiro; Ohmori, Koji; Moriue, Tetsuya; Igarashi, Junsuke; Kohno, Masakazu; Kosaka, Hiroaki; Kubota, Yasuo

    2011-05-01

    Obesity is known to be associated with a number of effects on skin physiology. KKA(y) obese mouse is a model of type 2 diabetes characterized by systemic oxidative stress because of severe obesity, hypertriglyceridaemia, hyperglycaemia and hyperinsulinaemia. We investigated lipid peroxidation and vascular endothelial growth factor (VEGF) expression in the skin of KKA(y) obese mice. We also investigated the effect of lipid peroxidation derivatives on VEGF production and proliferation in human epidermal keratinocyte cell line (HaCaT). The lipid peroxidation level in the mouse skin tissue was determined by measuring the levels of thiobarbituric acid-reactive substances. The levels of VEGF expression, p44/p42 mitogen-activated protein kinase (MAPK) activation and CD36 expression were analysed by Western blot. Their localization was examined by immunofluorescence. For the in vitro experiments, an enzyme-linked immunosorbent assay was utilized to measure VEGF secretion in the medium. In vitro experiments demonstrated that lipid peroxidation derivatives increased VEGF production in HaCaT cells, which was blocked by a p44/p42 MAPK inhibitor and anti-CD36 antibody. We observed increased levels of lipid peroxidation derivatives, p44/p42 MAPK activation and VEGF expression in the skin of KKA(y) obese mice. Notably, pitavastatin, an inhibitor of competitive 3-hydroxy-3-methylglutaryl coenzyme A reductase, suppressed all of these processes. Our results suggest that lipid peroxidation induces VEGF expression via CD36 and p44/p42 MAPK pathway in the skin of obese mice. © 2011 John Wiley & Sons A/S.

  1. GPx4, Lipid Peroxidation, and Cell Death: Discoveries, Rediscoveries, and Open Issues.

    PubMed

    Maiorino, Matilde; Conrad, Marcus; Ursini, Fulvio

    2017-05-30

    Iron-dependent lipid peroxidation is a complex oxidative process where phospholipid hydroperoxides (PLOOH) are produced in membranes and finally transformed into a series of decomposition products, some of which are endowed with biological activity. It is specifically prevented by glutathione peroxidase 4 (GPx4), the selenoenzyme that reduces PLOOH by glutathione (GSH). PLOOH is both a product and the major initiator of peroxidative chain reactions, as well as an activator of lipoxygenases. α-Tocopherol both specifically breaks peroxidative chain propagation and inhibits lipoxygenases. Thus, GPx4, GSH, and α-tocopherol are integrated in a concerted anti-peroxidant mechanism. Recent Advances: Ferroptosis has been recently identified as a cell death subroutine that is specifically activated by missing GPx4 activity and inhibited by iron chelation or α-tocopherol supplementation. Ferroptosis induction may underlie spontaneous human diseases, such as major neurodegeneration and neuroinflammation, causing an excessive cell death. The basic mechanism of ferroptosis, therefore, fits the features of activation of lipid peroxidation. Still lacking are convincing proofs that lipoxygenases are involved in ferroptosis. Also, unknown are the molecules eventually killing cells and the mechanisms underlying the drop of the cellular anti-peroxidant capacity. Molecular events and mechanisms of ferroptosis to be unraveled and validated on animal models are GPx4 inactivation, role of GSH concentration, increased iron availability, and membrane structure and composition. This is expected to drive drug discovery that is aimed at halting cell death in degenerative diseases or boosting it in cancer cells. Antioxid. Redox Signal. 00, 000-000.

  2. Coronary venous lipid peroxide concentrations after coronary angioplasty: correlation with biochemical and electrocardiographic evidence of myocardial ischaemia

    PubMed Central

    Oldroyd, K G; Paterson, J R; Rumley, A G; Eteiba, H; Rae, A P; Shepherd, J; Cobbe, S M; Hutton, I

    1992-01-01

    Background—Raised lipid peroxide concentrations in coronary venous plasma have been reported after coronary angioplasty in humans. This may reflect increased free radical activity after myocardial ischaemia and reperfusion. If so, it may be possible to correlate lipid peroxide concentrations with the degree of myocardial ischaemia produced during angioplasty. Methods—15 patients (age range 42-70; 12 men) with stable angina pectoris undergoing angioplasty of a proximal left anterior descending coronary artery stenosis were studied. Plasma lipid peroxide and lactate concentrations were measured in sequential blood samples taken from the great cardiac vein before and immediately after one to five serial 60 second balloon inflations. The maximum ST segment shift during each balloon inflation was also measured. Results—Lipid peroxide concentrations in coronary venous plasma were raised from pre-angioplasty values by more than 2 SDs of the relevant measurement error after 27 out of 46 (59%) balloon inflations. Lactate concentrations were raised after 43 out of 46 (93%) balloon inflations. No significant difference was found between the peak percentage change of either lipid peroxide or lactate concentrations after any of the first three serial inflations. The maximum ST segment shift after each of the first three serial inflations was also similar. Coronary venous lactate concentrations after balloon inflation correlated positively with the maximum ST segment shift, but did not correlate with lipid peroxide concentrations. Conclusions—Raised lipid peroxide concentrations in coronary venous plasma can be detected in humans after balloon angioplasty. There is no positive correlation between lipid peroxide concentrations in coronary venous plasma after angioplasty and the degree of preceding myocardial ischaemia as assessed by either ST segment shift or lactate production. These indices showed that one to three serial 60 second balloon inflations each produce a

  3. Synthetic Strategies for Peroxide Ring Construction in Artemisinin.

    PubMed

    Vil', Vera A; Yaremenko, Ivan A; Ilovaisky, Alexey I; Terent'ev, Alexander O

    2017-01-11

    The present review summarizes publications on the artemisinin peroxide fragment synthesis from 1983 to 2016. The data are classified according to the structures of a precursor used in the key peroxidation step of artemisinin peroxide cycle synthesis. The first part of the review comprises the construction of artemisinin peroxide fragment in total syntheses, in which peroxide artemisinin ring resulted from reactions of unsaturated keto derivatives with singlet oxygen or ozone. In the second part, the methods of artemisinin synthesis based on transformations of dihydroartemisinic acid are highlighted.

  4. MEMS-Based Satellite Micropropulsion Via Catalyzed Hydrogen Peroxide Decomposition

    NASA Technical Reports Server (NTRS)

    Hitt, Darren L.; Zakrzwski, Charles M.; Thomas, Michael A.; Bauer, Frank H. (Technical Monitor)

    2001-01-01

    Micro-electromechanical systems (MEMS) techniques offer great potential in satisfying the mission requirements for the next generation of "micro-scale" satellites being designed by NASA and Department of Defense agencies. More commonly referred to as "nanosats", these miniature satellites feature masses in the range of 10-100 kg and therefore have unique propulsion requirements. The propulsion systems must be capable of providing extremely low levels of thrust and impulse while also satisfying stringent demands on size, mass, power consumption and cost. We begin with an overview of micropropulsion requirements and some current MEMS-based strategies being developed to meet these needs. The remainder of the article focuses the progress being made at NASA Goddard Space Flight Center towards the development of a prototype monopropellant MEMS thruster which uses the catalyzed chemical decomposition of high concentration hydrogen peroxide as a propulsion mechanism. The products of decomposition are delivered to a micro-scale converging/diverging supersonic nozzle which produces the thrust vector; the targeted thrust level approximately 500 N with a specific impulse of 140-180 seconds. Macro-scale hydrogen peroxide thrusters have been used for satellite propulsion for decades; however, the implementation of traditional thruster designs on a MEMS scale has uncovered new challenges in fabrication, materials compatibility, and combustion and hydrodynamic modeling. A summary of the achievements of the project to date is given, as is a discussion of remaining challenges and future prospects.

  5. Are sensory TRP channels biological alarms for lipid peroxidation?

    PubMed

    Choi, Seung-In; Yoo, Sungjae; Lim, Ji Yeon; Hwang, Sun Wook

    2014-09-17

    Oxidative stress induces numerous biological problems. Lipid oxidation and peroxidation appear to be important steps by which exposure to oxidative stress leads the body to a disease state. For its protection, the body has evolved to respond to and eliminate peroxidation products through the acquisition of binding proteins, reducing and conjugating enzymes, and excretion systems. During the past decade, researchers have identified a group of ion channel molecules that are activated by oxidized lipids: transient receptor potential (TRP) channels expressed in sensory neurons. These ion channels are fundamentally detectors and signal converters for body-damaging environments such as heat and cold temperatures, mechanical attacks, and potentially toxic substances. When messages initiated by TRP activation arrive at the brain, we perceive pain, which results in our preparing defensive responses. Excessive activation of the sensory neuronal TRP channels upon prolonged stimulations sometimes deteriorates the inflammatory state of damaged tissues by promoting neuropeptide release from expresser neurons. These same paradigms may also work for pathologic changes in the internal lipid environment upon exposure to oxidative stress. Here, we provide an overview of the role of TRP channels and oxidized lipid connections during abnormally increased oxidative signaling, and consider the sensory mechanism of TRP detection as an alert system.

  6. Control of oxygen release from peroxides using polymers.

    PubMed

    Steg, Hilde; Buizer, Arina T; Woudstra, Willem; Veldhuizen, Albert G; Bulstra, Sjoerd K; Grijpma, Dirk W; Kuijer, Roel

    2015-07-01

    An important limitation in cell therapy for the regeneration of tissue is the initial lack of oxygen. After implantation of large 3D cell-seeded structures, cells die rather than contribute to tissue regenerating. Here we've tested oxygen-releasing materials to improve cell survival and growth after implantation. Calcium peroxide (CaO2) in a polymer matrix was used as source of oxygen. Two polymers were tested in order to slow down and extend the period of oxygen release, poly(D,L-lactic acid) and poly(lactic-co-glycolic acid). Compared to CaO2 particles, both releasing systems showed an initially higher and shorter oxygen release. Human mesenchymal stromal cells cultured on casted films of these oxygen-releasing composites required catalase to proliferate, indicating the production of cytotoxic hydrogen peroxide as intermediate. Poly(D,L-lactic acid) and poly(lactic-co-glycolic acid) are less suited for slowly oxygen-releasing materials. Catalase was able to reduce the cytotoxic effect of H2O2.

  7. 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.

  8. High levels of lipid peroxidation in semen of diabetic patients.

    PubMed

    La Vignera, S; Condorelli, R A; Vicari, E; D'Agata, R; Salemi, M; Calogero, A E

    2012-05-01

    The aim of this study was to evaluate the level of malondialdehyde (MDA) (one of the final products of lipid peroxidation and well-known marker of oxidative stress) in semen of infertile men with type 2 diabetes and to investigate its relationship with their glycaemic control. Forty infertile men with type 2 diabetes were evaluated. The mean ages were 36.5 ± 8.0. Men with diabetes were divided into two groups. Group A (n = 20) with glycated haemoglobin >10% and group B (n = 20) with glycated haemoglobin <7%. A single sample was examined according to the criteria of the World Health Organization (WHO Laboratory Manual for the Examination of Human Semen and Sperm-Cervical Mucus Interaction, 1999, Cambridge University Press). MDA was assessed using the thiobarbituric acid method. MDA concentration in semen of group A patients (0.95 ± 0.35 nmol ml(-1)) was significantly higher than in group B patients (0.43 ± 0.13 nmol ml(-1)) (P value < 0.05) and had negative relationship with sperm density (r = -.717; P value < 0.05), total sperm count (r = -.625; P value < 0.05), progressive motility (r = -.489; P value < 0.05) and normal forms (r = -.545; P value < 0.05). Based on these results, it could be concluded that increase in lipid peroxidation in men with diabetes with poor metabolic control was associated with low sperm quality. © 2011 Blackwell Verlag GmbH.

  9. Silver-palladium catalysts for the direct synthesis of hydrogen peroxide

    NASA Astrophysics Data System (ADS)

    Khan, Zainab; Dummer, Nicholas F.; Edwards, Jennifer K.

    2017-11-01

    A series of bimetallic silver-palladium catalysts supported on titania were prepared by wet impregnation and assessed for the direct synthesis of hydrogen peroxide, and its subsequent side reactions. The addition of silver to a palladium catalyst was found to significantly decrease hydrogen peroxide productivity and hydrogenation, but crucially increase the rate of decomposition. The decomposition product, which is predominantly hydroxyl radicals, can be used to decrease bacterial colonies. The interaction between silver and palladium was characterized using scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy (XPS) and temperature programmed reduction (TPR). The results of the TPR and XPS indicated the formation of a silver-palladium alloy. The optimal 1% Ag-4% Pd/TiO2 bimetallic catalyst was able to produce approximately 200 ppm of H2O2 in 30 min. The findings demonstrate that AgPd/TiO2 catalysts are active for the synthesis of hydrogen peroxide and its subsequent decomposition to reactive oxygen species. The catalysts are promising for use in wastewater treatment as they combine the disinfectant properties of silver, hydrogen peroxide production and subsequent decomposition. This article is part of a discussion meeting issue 'Providing sustainable catalytic solutions for a rapidly changing world'.

  10. Stability of peroxide-containing uranyl minerals.

    PubMed

    Kubatko, Karrie-Ann Hughes; Helean, Katheryn B; Navrotsky, Alexandra; Burns, Peter C

    2003-11-14

    Minerals containing peroxide are limited to studtite, (UO2)O2(H2O)4, and metastudtite, (UO2)O2(H2O)2. High-temperature oxide-melt solution calorimetry and solubility measurements for studtite (standard enthalpy of formation at 298 kelvin is -2344.7 +/- 4.0 kilojoules per mole from the elements) establishes that these phases are stable in peroxide-bearing environments, even at low H2O2 concentrations. Natural radioactivity in a uranium deposit, or the radioactivity of nuclear waste, can create sufficient H2O2 by alpha radiolysis of water for studtite formation. Studtite and metastudtite may be important alteration phases of nuclear waste in a geological repository and of spent fuel under any long-term storage, possibly at the expense of the commonly expected uranyl oxide hydrates and uranyl silicates.

  11. Alkene anti-Dihydroxylation with Malonoyl Peroxides.

    PubMed

    Alamillo-Ferrer, Carla; Davidson, Stuart C; Rawling, Michael J; Theodoulou, Natalie H; Campbell, Matthew; Humphreys, Philip G; Kennedy, Alan R; Tomkinson, Nicholas C O

    2015-10-16

    Malonoyl peroxide 1, prepared in a single step from the commercially available diacid, is an effective reagent for the anti-dihydroxylation of alkenes. Reaction of 1 with an alkene in the presence of acetic acid at 40 °C followed by alkaline hydrolysis leads to the corresponding diol (35-92%) with up to 13:1 anti-selectivity. A mechanism consistent with experimental findings is proposed that accounts for the selectivity observed.

  12. Inactivation of human myeloperoxidase by hydrogen peroxide.

    PubMed

    Paumann-Page, Martina; Furtmüller, Paul G; Hofbauer, Stefan; Paton, Louise N; Obinger, Christian; Kettle, Anthony J

    2013-11-01

    Human myeloperoxidase (MPO) uses hydrogen peroxide generated by the oxidative burst of neutrophils to produce an array of antimicrobial oxidants. During this process MPO is irreversibly inactivated. This study focused on the unknown role of hydrogen peroxide in this process. When treated with low concentrations of H2O2 in the absence of reducing substrates, there was a rapid loss of up to 35% of its peroxidase activity. Inactivation is proposed to occur via oxidation reactions of Compound I with the prosthetic group or amino acid residues. At higher concentrations hydrogen peroxide acts as a suicide substrate with a rate constant of inactivation of 3.9 × 10(-3) s(-1). Treatment of MPO with high H2O2 concentrations resulted in complete inactivation, Compound III formation, destruction of the heme groups, release of their iron, and detachment of the small polypeptide chain of MPO. Ten of the protein's methionine residues were oxidized and the thermal stability of the protein decreased. Inactivation by high concentrations of H2O2 is proposed to occur via the generation of reactive oxidants when H2O2 reacts with Compound III. These mechanisms of inactivation may occur inside neutrophil phagosomes when reducing substrates for MPO become limiting and could be exploited when designing pharmacological inhibitors. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

  13. Application of FTIR-ATR Spectroscopy to Determine the Extent of Lipid Peroxidation in Plasma during Haemodialysis.

    PubMed

    Oleszko, Adam; Olsztyńska-Janus, Sylwia; Walski, Tomasz; Grzeszczuk-Kuć, Karolina; Bujok, Jolanta; Gałecka, Katarzyna; Czerski, Albert; Witkiewicz, Wojciech; Komorowska, Małgorzata

    2015-01-01

    During a haemodialysis (HD), because of the contact of blood with the surface of the dialyser, the immune system becomes activated and reactive oxygen species (ROS) are released into plasma. Particularly exposed to the ROS are lipids and proteins contained in plasma, which undergo peroxidation. The main breakdown product of oxidized lipids is the malondialdehyde (MDA). A common method for measuring the concentration of MDA is a thiobarbituric acid reactive substances (TBARS) method. Despite the formation of MDA in plasma during HD, its concentration decreases because it is removed from the blood in the dialyser. Therefore, this research proposes the Fourier Transform Infrared Attenuated Total Reflectance (FTIR-ATR) spectroscopy, which enables determination of primary peroxidation products. We examined the influence of the amount of hydrogen peroxide added to lipid suspension that was earlier extracted from plasma specimen on lipid peroxidation with use of TBARS and FTIR-ATR methods. Linear correlation between these methods was shown. The proposed method was effective during the evaluation of changes in the extent of lipid peroxidation in plasma during a haemodialysis in sheep. A measurement using the FTIR-ATR showed an increase in plasma lipid peroxidation after 15 and 240 minutes of treatment, while the TBARS concentration was respectively lower.

  14. Application of FTIR-ATR Spectroscopy to Determine the Extent of Lipid Peroxidation in Plasma during Haemodialysis

    PubMed Central

    Oleszko, Adam; Olsztyńska-Janus, Sylwia; Grzeszczuk-Kuć, Karolina; Bujok, Jolanta; Gałecka, Katarzyna; Czerski, Albert; Witkiewicz, Wojciech; Komorowska, Małgorzata

    2015-01-01

    During a haemodialysis (HD), because of the contact of blood with the surface of the dialyser, the immune system becomes activated and reactive oxygen species (ROS) are released into plasma. Particularly exposed to the ROS are lipids and proteins contained in plasma, which undergo peroxidation. The main breakdown product of oxidized lipids is the malondialdehyde (MDA). A common method for measuring the concentration of MDA is a thiobarbituric acid reactive substances (TBARS) method. Despite the formation of MDA in plasma during HD, its concentration decreases because it is removed from the blood in the dialyser. Therefore, this research proposes the Fourier Transform Infrared Attenuated Total Reflectance (FTIR-ATR) spectroscopy, which enables determination of primary peroxidation products. We examined the influence of the amount of hydrogen peroxide added to lipid suspension that was earlier extracted from plasma specimen on lipid peroxidation with use of TBARS and FTIR-ATR methods. Linear correlation between these methods was shown. The proposed method was effective during the evaluation of changes in the extent of lipid peroxidation in plasma during a haemodialysis in sheep. A measurement using the FTIR-ATR showed an increase in plasma lipid peroxidation after 15 and 240 minutes of treatment, while the TBARS concentration was respectively lower. PMID:25961007

  15. The impact of iron on the bleaching efficacy of hydrogen peroxide in liquid whey systems.

    PubMed

    Jervis, Suzanne M; Drake, MaryAnne

    2013-02-01

    Whey is a value-added product that is utilized in many food and beverage applications for its nutritional and functional properties. Whey and whey products are generally utilized in dried ingredient applications. One of the primary sources of whey is from colored Cheddar cheese manufacture that contains the pigment annatto resulting in a characteristic yellow colored Cheddar cheese. The colorant is also present in the liquid cheese whey and must be bleached so that it can be used in ingredient applications without imparting a color. Hydrogen peroxide and benzoyl peroxide are 2 commercially approved chemical bleaching agents for liquid whey. Concerns regarding bleaching efficacy, off-flavor development, and functionality changes have been previously reported for whey bleached with hydrogen peroxide and benzoyl peroxide. It is very important for the dairy industry to understand how bleaching can impact flavor and functionality of dried ingredients. Currently, the precise mechanisms of off-flavor development and functionality changes are not entirely understood. Iron reactions in a bleached liquid whey system may play a key role. Reactions between iron and hydrogen peroxide have been widely studied since the reaction between these 2 relatively stable species can cause great destruction in biological and chemical systems. The actual mechanism of the reaction of iron with hydrogen peroxide has been a controversy in the chemistry and biological community. The precise mechanism for a given reaction can vary greatly based upon the concentration of reactants, temperature, pH, and addition of biological material. In this review, some hypotheses for the mechanisms of iron reactions that may occur in fluid whey that may impact bleaching efficacy, off-flavor development, and changes in functionality are presented. Cheese whey is bleached to remove residual carotenoid cheese colorant. Concerns regarding bleaching efficacy, off-flavor development, and functionality changes have

  16. Development of a sensitive long pathlength absorbance photometer to quantify peroxides in aerosol particles (Peroxide-LOPAP)

    NASA Astrophysics Data System (ADS)

    Mertes, P.; Pfaffenberger, L.; Dommen, J.; Kalberer, M.; Baltensperger, U.

    2012-02-01

    A new off-line instrument to quantify peroxides in aerosol particles using iodometry in long pathlength absorption spectroscopy has been developed and is called peroxide long pathlength absorbance photometer (Peroxide-LOPAP). The new analytical setup features important technical innovations compared to hitherto published iodometric peroxide measurements. Firstly, the extraction, chemical conversion and measurement of the aerosol samples are performed in a closed oxygen-free (∼1 ppb) environment. Secondly, a 50-cm optical detection cell is used for an increased photometric sensitivity. The limit of detection was 0.1 μM peroxide in solution or 0.25 nmol m-3 with respect to an aerosol sample volume of 1000 l. The test reaction was done at a constant elevated temperature of 40 °C and the reaction time was 60 min. Calibration experiments showed that the test reaction with all reactive peroxides, i.e. hydrogen peroxide (H2O2), peracids and peroxides with vicinal carbonyl groups (e.g. lauroyl peroxide) goes to completion and their sensitivity (slope of calibration curve) varies by only ±5%. However, very stable peroxides have a lower sensitivity. For example tert-butyl hydroperoxide shows only 37% sensitivity compared to H2O2 after 1h. A kinetic study revealed that even after 5 h only 85% of this stable compound had reacted. The time trends of the peroxide content in secondary organic aerosol (SOA) from the ozonolysis and photo-oxidation of α-pinene in smog chamber experiments were measured. The highest amount of peroxides with 34% (assuming a MW of 300 g mol-1) was found in freshly generated SOA from α-pinene ozonolysis. Contents decreased with increasing NO levels in the photo-oxidation experiments. A decrease of the peroxide content was observed with aging of the aerosol indicating a decomposition of peroxides in the particles.

  17. Development of a sensitive long path absorption photometer to quantify peroxides in aerosol particles (Peroxide-LOPAP)

    NASA Astrophysics Data System (ADS)

    Mertes, P.; Pfaffenberger, L.; Dommen, J.; Kalberer, M.; Baltensperger, U.

    2012-10-01

    A new off-line instrument to quantify peroxides in aerosol particles using iodometry in long path absorption spectroscopy has been developed and is called peroxide long path absorption photometer (Peroxide-LOPAP). The new analytical setup features important technical innovations compared to hitherto published iodometric peroxide measurements. Firstly, the extraction, chemical conversion and measurement of the aerosol samples are performed in a closed oxygen-free (~ 1 ppb) environment. Secondly, a 50-cm optical detection cell is used for an increased photometric sensitivity. The limit of detection was 0.1 μM peroxide in solution or 0.25 nmol m-3 with respect to an aerosol sample volume of 1 m3. The test reaction was done at a constant elevated temperature of 40 °C and the reaction time was 60 min. Calibration experiments showed that the test reaction with all reactive peroxides, i.e. hydrogen peroxide (H2O2), peracids and peroxides with vicinal carbonyl groups (e.g. lauroyl peroxide) goes to completion and their sensitivity (slope of calibration curve) varies by only ±5%. However, very inert peroxides have a lower sensitivity. For example, tert-butyl hydroperoxide shows only 37% sensitivity compared to H2O2 after 1 h. A kinetic study revealed that even after 5 h only 85% of this inert compound had reacted. The time trends of the peroxide content in secondary organic aerosol (SOA) from the ozonolysis and photo-oxidation of α-pinene in smog chamber experiments were measured. The highest mass fraction of peroxides with 34% (assuming a molecular weight of 300 g mol-1) was found in freshly generated SOA from α-pinene ozonolysis. Mass fractions decreased with increasing NO levels in the photo-oxidation experiments. A decrease of the peroxide content was also observed with aging of the aerosol, indicating a decomposition of peroxides in the particles.

  18. Desulfuration of 2-thiouridine with hydrogen peroxide in the physiological pH range 6.6-7.6 is pH-dependent and results in two distinct products.

    PubMed

    Sochacka, Elzbieta; Bartos, Paulina; Kraszewska, Karina; Nawrot, Barbara

    2013-11-01

    The 2-thiomodified nucleosides, located at first position of tRNAs anticodon, may constitute a primary target for oxidative attack under conditions of oxidative stress. Desulfuration of 2-thiouridine (S2U) was investigated in the (1)H NMR scale in the presence of 100mM H2O2 and phosphate buffer in the physiological pH range, from pH 6.6 to 7.6. The obtained data demonstrate an intriguing result that within one unit of the pH range uridine is the major product of the S2U desulfuration in the pH 7.6, while the 4-pyrimidinone nucleoside (H2U) is dominant in pH 6.6. The possible desulfuration pathway and the biological importance of the transformation of S2U either to U or H2U are discussed in the context of the tRNA oxidative damage. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Peroxides with antiplasmodial activity inhibit proliferation of Perkinsus olseni, the causative agent of Perkinsosis in bivalves.

    PubMed

    Araujo, N C P; Afonso, R; Bringela, A; Cancela, M L; Cristiano, M L S; Leite, R B

    2013-12-01

    Perkinsus olseni, the causative agent of Perkinsosis, can drastically affect the survival of target marine mollusks, with dramatic economic consequences for aquaculture. P. olseni is a member of the Alveolata group, which also comprises parasites that are highly relevant for medical and veterinary sciences such as Plasmodium falciparum and Toxoplasma. P. olseni shares several unique metabolic pathways with those pathological parasites but is not toxic to humans. In this work, six antimalarially active peroxides, derived from the natural product artemisinin or synthetic trioxolanes, were synthesized and tested on P. olseni proliferation and survival. All peroxides tested revealed an inhibitory effect on P. olseni proliferation at micromolar concentrations. The relevance of the peroxide functionality on toxicity and the effect of Fe(II)-intracellular concentration on activity were also evaluated. Results demonstrated that the peroxide functionality is the toxofore and intracellular iron concentration also proved to be a crucial co-factor on the activation of peroxides in P. olseni. These data points to a mechanism of bioactivation in P. olseni sharing similarities with the one proposed in P. falciparum parasites. Preliminary studies on bioaccumulation were conducted using fluorescent-labeled peroxides. Results show that synthetic trioxolanes tend to accumulate on a vacuole while the labeled artemisinin accumulates in the cytoplasm. Preliminary experiments on differential genes expression associated to Fe(II) transport protein (Nramp) and calcium transport protein (ATP6/SERCA) were also conducted by qPCR. Results point to a fourfold increase in expression of both genes upon exposure to trioxolanes and approximately twofold upon exposure to artemisinin derivatives. Data obtained in this investigation is relevant for better understanding of the biology of Perkinsus and may also be important in the development of new strategies for Perkinsosis prevention and control.

  20. Uptake of methacrolein into aqueous solutions of sulfuric acid and hydrogen peroxide.

    PubMed

    Liu, Ze; Wu, Ling-Yan; Wang, Tian-He; Ge, Mao-Fa; Wang, Wei-Gang

    2012-01-12

    Multiphase acid-catalyzed oxidation by hydrogen peroxide has been suggested to be a potential route to secondary organic aerosol (SOA) formation from isoprene and its gas-phase oxidation products, but the kinetics and chemical mechanism remain largely uncertain. Here we report the first measurement of uptake of methacrolein into aqueous solutions of sulfuric acid and hydrogen peroxide in the temperature range of 253-293 K. The steady-state uptake coefficients were acquired and increased quickly with increasing sulfuric acid concentration and decreasing temperature. Propyne, acetone, and 2,3-dihydroxymethacrylic acid were suggested as the products. The chemical mechanism is proposed to be the oxidation of carbonyl group and C═C double bonds by peroxide hydrogen in acidic environment, which could explain the large content of polyhydroxyl compounds in atmospheric fine particles. These results indicate that multiphase acid-catalyzed oxidation of methacrolein by hydrogen peroxide can contribute to SOA mass in the atmosphere, especially in the upper troposphere.

  1. 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.

  2. 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. Copyright © 2011. Published by Elsevier B.V.

  3. Kinetics of hydrogen peroxide decomposition by catalase: hydroxylic solvent effects.

    PubMed

    Raducan, Adina; Cantemir, Anca Ruxandra; Puiu, Mihaela; Oancea, Dumitru

    2012-11-01

    The effect of water-alcohol (methanol, ethanol, propan-1-ol, propan-2-ol, ethane-1,2-diol and propane-1,2,3-triol) binary mixtures on the kinetics of hydrogen peroxide decomposition in the presence of bovine liver catalase is investigated. In all solvents, the activity of catalase is smaller than in water. The results are discussed on the basis of a simple kinetic model. The kinetic constants for product formation through enzyme-substrate complex decomposition and for inactivation of catalase are estimated. The organic solvents are characterized by several physical properties: dielectric constant (D), hydrophobicity (log P), concentration of hydroxyl groups ([OH]), polarizability (α), Kamlet-Taft parameter (β) and Kosower parameter (Z). The relationships between the initial rate, kinetic constants and medium properties are analyzed by linear and multiple linear regression.

  4. 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 (H 2 O 2 ) from hydrogen and oxygen has been studied using an Au-Pd/TiO 2 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 H 2 O 2 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 H 2 O 2 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.

  5. Mitochondrial generation of superoxide and hydrogen peroxide as the source of mitochondrial redox signaling.

    PubMed

    Brand, Martin D

    2016-11-01

    This review examines the generation of reactive oxygen species by mammalian mitochondria, and the status of different sites of production in redox signaling and pathology. Eleven distinct mitochondrial sites associated with substrate oxidation and oxidative phosphorylation leak electrons to oxygen to produce superoxide or hydrogen peroxide: oxoacid dehydrogenase complexes that feed electrons to NAD + ; respiratory complexes I and III, and dehydrogenases, including complex II, that use ubiquinone as acceptor. The topologies, capacities, and substrate dependences of each site have recently clarified. Complex III and mitochondrial glycerol 3-phosphate dehydrogenase generate superoxide to the external side of the mitochondrial inner membrane as well as the matrix, the other sites generate superoxide and/or hydrogen peroxide exclusively in the matrix. These different site-specific topologies are important for redox signaling. The net rate of superoxide or hydrogen peroxide generation depends on the substrates present and the antioxidant systems active in the matrix and cytosol. The rate at each site can now be measured in complex substrate mixtures. In skeletal muscle mitochondria in media mimicking muscle cytosol at rest, four sites dominate, two in complex I and one each in complexes II and III. Specific suppressors of two sites have been identified, the outer ubiquinone-binding site in complex III (site III Qo ) and the site in complex I active during reverse electron transport (site I Q ). These suppressors prevent superoxide/hydrogen peroxide production from a specific site without affecting oxidative phosphorylation, making them excellent tools to investigate the status of the sites in redox signaling, and to suppress the sites to prevent pathologies. They allow the cellular roles of mitochondrial superoxide/hydrogen peroxide production to be investigated without catastrophic confounding bioenergetic effects. They show that sites III Qo and I Q are active in cells

  6. 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

  7. Depletion Rate of Hydrogen Peroxide from Sodium Perborate Bleaching Agent.

    PubMed

    Tran, Liliann; Orth, Rebecca; Parashos, Peter; Tao, Ying; Tee, Calvin W J; Thomas, Vineet Thenalil; Towers, Georgina; Truong, Diem Thuy; Vinen, Cynthia; Reynolds, Eric C

    2017-03-01

    Internal bleaching of discolored teeth uses sodium perborate reacting with water to form the active agent, hydrogen peroxide (H 2 O 2 ). Sodium perborate is replaced at varying time intervals depending on clinician preference and until esthetically acceptable results are achieved, but this is done without scientific basis. This study measured the depletion rate of hydrogen peroxide from sodium perborate as a bleaching agent. Two sodium perborate bleaching products (Odontobleach [Australian Dental Manufacturing, Kenmore Hills, Queensland, Australia] and Endosure Perborate Micro [Dentalife, Ringwood, Victoria, Australia]) and distilled deionized water mixtures at ratios of 25 μg/mL, 50 μg/mL, and 100 μg/mL were placed into sealed microtubes and incubated at 37°C. H 2 O 2 concentrations were measured at 23 time points over 4 weeks. Quantification of H 2 O 2 concentrations was obtained using a ferrothiocyanate oxidation reduction reaction followed by spectrophotometry readings. The H 2 O 2 concentration rapidly peaked within 27 hours and reached a plateau by about 3 days (75 hours). Low levels of H 2 O 2 were evident beyond 3 days and for at least 28 days. No significant differences were found between the 2 sodium perborate products. There was also no significant difference in the depletion rate between the different ratios. Based on the chemistry of H 2 O 2 depletion, the minimum replacement interval for the bleaching agent is 3 days. Frequent replacements of the perborate clinically may be unnecessary because of the continued presence of low H 2 O 2 levels for at least 28 days. Although these data cannot be extrapolated to the clinical situation, they set a baseline for further studies to address the many clinical variables influencing internal bleaching. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  8. High throughput assay for evaluation of reactive carbonyl scavenging capacity☆

    PubMed Central

    Vidal, N.; Cavaille, J.P.; Graziani, F.; Robin, M.; Ouari, O.; Pietri, S.; Stocker, P.

    2014-01-01

    Many carbonyl species from either lipid peroxidation or glycoxidation are extremely reactive and can disrupt the function of proteins and enzymes. 4-hydroxynonenal and methylglyoxal are the most abundant and toxic lipid-derived reactive carbonyl species. The presence of these toxics leads to carbonyl stress and cause a significant amount of macromolecular damages in several diseases. Much evidence indicates trapping of reactive carbonyl intermediates may be a useful strategy for inhibiting or decreasing carbonyl stress-associated pathologies. There is no rapid and convenient analytical method available for the assessment of direct carbonyl scavenging capacity, and a very limited number of carbonyl scavengers have been identified to date, their therapeutic potential being highlighted only recently. In this context, we have developed a new and rapid sensitive fluorimetric method for the assessment of reactive carbonyl scavengers without involvement glycoxidation systems. Efficacy of various thiol- and non-thiol-carbonyl scavenger pharmacophores was tested both using this screening assay adapted to 96-well microplates and in cultured cells. The scavenging effects on the formation of Advanced Glycation End-product of Bovine Serum Albumin formed with methylglyoxal, 4-hydroxynonenal and glucose-glycated as molecular models were also examined. Low molecular mass thiols with an α-amino-β-mercaptoethane structure showed the highest degree of inhibitory activity toward both α,β-unsaturated aldehydes and dicarbonyls. Cysteine and cysteamine have the best scavenging ability toward methylglyoxal. WR-1065 which is currently approved for clinical use as a protective agent against radiation and renal toxicity was identified as the best inhibitor of 4-hydroxynonenal. PMID:24688895

  9. High throughput assay for evaluation of reactive carbonyl scavenging capacity.

    PubMed

    Vidal, N; Cavaille, J P; Graziani, F; Robin, M; Ouari, O; Pietri, S; Stocker, P

    2014-01-01

    Many carbonyl species from either lipid peroxidation or glycoxidation are extremely reactive and can disrupt the function of proteins and enzymes. 4-hydroxynonenal and methylglyoxal are the most abundant and toxic lipid-derived reactive carbonyl species. The presence of these toxics leads to carbonyl stress and cause a significant amount of macromolecular damages in several diseases. Much evidence indicates trapping of reactive carbonyl intermediates may be a useful strategy for inhibiting or decreasing carbonyl stress-associated pathologies. There is no rapid and convenient analytical method available for the assessment of direct carbonyl scavenging capacity, and a very limited number of carbonyl scavengers have been identified to date, their therapeutic potential being highlighted only recently. In this context, we have developed a new and rapid sensitive fluorimetric method for the assessment of reactive carbonyl scavengers without involvement glycoxidation systems. Efficacy of various thiol- and non-thiol-carbonyl scavenger pharmacophores was tested both using this screening assay adapted to 96-well microplates and in cultured cells. The scavenging effects on the formation of Advanced Glycation End-product of Bovine Serum Albumin formed with methylglyoxal, 4-hydroxynonenal and glucose-glycated as molecular models were also examined. Low molecular mass thiols with an α-amino-β-mercaptoethane structure showed the highest degree of inhibitory activity toward both α,β-unsaturated aldehydes and dicarbonyls. Cysteine and cysteamine have the best scavenging ability toward methylglyoxal. WR-1065 which is currently approved for clinical use as a protective agent against radiation and renal toxicity was identified as the best inhibitor of 4-hydroxynonenal.

  10. Lichen metabolites modulate hydrogen peroxide and nitric oxide in mouse macrophages.

    PubMed

    Carlos, Iracilda Z; Quilles, Marcela B; Carli, Camila B A; Maia, Danielle C G; Benzatti, Fernanda P; Lopes, Thiago I B; Gianini, Aline S; Brum, Rosenei L; Vilegas, Wagner; dos Santos, Lourdes C; Honda, Neli K

    2009-01-01

    The activities of perlatolic acid (1), atranorin (2), and lecanoric acid (3) and their derivatives, such as orsellinates and beta-methyl orsellinates obtained by alcoholysis, were assessed for stimulation of the release of hydrogen peroxide and nitric oxide in cultures of peritoneal macrophage cells from mice. The hydrogen peroxide production was estimated by oxidation of phenol red, while the Griess reagent was used to determine the nitric oxide production. 1 and 4-methoxy-ethyl orsellinate (XVII) were the compounds that induced the greatest release of H2O2, whereas n-pentyl orsellinate (IV), iso-propyl orsellinate (V), sec-butyl orsellinate (VI), and XVII induced a small release of NO. These results indicate that lichen products and their derivatives have potential immune-modulating activities.

  11. Alkaline Peroxide Delignification of Corn Stover

    SciTech Connect

    Mittal, Ashutosh; Katahira, Rui; Donohoe, Bryon S.

    2017-05-30

    Selective biomass fractionation into carbohydrates and lignin is a key challenge in the conversion of lignocellulosic biomass to fuels and chemicals. In the present study, alkaline hydrogen peroxide (AHP) pretreatment was investigated to fractionate lignin from polysaccharides in corn stover (CS), with a particular emphasis on the fate of the lignin for subsequent valorization. The influence of peroxide loading on delignification during AHP pretreatment was examined over the range of 30-500 mg H2O2/g dry CS at 50 degrees C for 3 h. Mass balances were conducted on the solid and liquid fractions generated after pretreatment for each of the threemore » primary components, lignin, hemicellulose, and cellulose. AHP pretreatment at 250 mg H2O2/g dry CS resulted in the pretreated solids with more than 80% delignification consequently enriching the carbohydrate fraction to >90%. Two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy of the AHP pretreated residue shows that, under high peroxide loadings (>250 mg H2O2/g dry CS), most of the side chain structures were oxidized and the aryl-ether bonds in lignin were partially cleaved, resulting in significant delignification of the pretreated residues. Gel permeation chromatography (GPC) analysis shows that AHP pretreatment effectively depolymerizes CS lignin into low molecular weight (LMW) lignin fragments in the aqueous fraction. Imaging of AHP pretreated residues shows a more granular texture and a clear lamellar pattern in secondary walls, indicative of layers of varying lignin removal or relocalization. Enzymatic hydrolysis of this pretreated residue at 20 mg/g of glucan resulted in 90% and 80% yields of glucose and xylose, respectively, after 120 h. Overall, AHP pretreatment is able to selectively remove more than 80% of the lignin from biomass in a form that has potential for downstream valorization processes and enriches the solid pulp into a highly digestible material.« less

  12. Alkaline Peroxide Delignification of Corn Stover

    SciTech Connect

    Mittal, Ashutosh; Katahira, Rui; Donohoe, Bryon S.; Black, Brenna A.; Pattathil, Sivakumar; Stringer, Jack M.; Beckham, Gregg T.

    2017-05-30

    Selective biomass fractionation into carbohydrates and lignin is a key challenge in the conversion of lignocellulosic biomass to fuels and chemicals. In the present study, alkaline hydrogen peroxide (AHP) pretreatment was investigated to fractionate lignin from polysaccharides in corn stover (CS), with a particular emphasis on the fate of the lignin for subsequent valorization. The influence of peroxide loading on delignification during AHP pretreatment was examined over the range of 30-500 mg H2O2/g dry CS at 50 degrees C for 3 h. Mass balances were conducted on the solid and liquid fractions generated after pretreatment for each of the three primary components, lignin, hemicellulose, and cellulose. AHP pretreatment at 250 mg H2O2/g dry CS resulted in the pretreated solids with more than 80% delignification consequently enriching the carbohydrate fraction to >90%. Two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy of the AHP pretreated residue shows that, under high peroxide loadings (>250 mg H2O2/g dry CS), most of the side chain structures were oxidized and the aryl-ether bonds in lignin were partially cleaved, resulting in significant delignification of the pretreated residues. Gel permeation chromatography (GPC) analysis shows that AHP pretreatment effectively depolymerizes CS lignin into low molecular weight (LMW) lignin fragments in the aqueous fraction. Imaging of AHP pretreated residues shows a more granular texture and a clear lamellar pattern in secondary walls, indicative of layers of varying lignin removal or relocalization. Enzymatic hydrolysis of this pretreated residue at 20 mg/g of glucan resulted in 90% and 80% yields of glucose and xylose, respectively, after 120 h. Overall, AHP pretreatment is able to selectively remove more than 80% of the lignin from biomass in a form that has potential for downstream valorization processes and enriches the solid pulp into a highly digestible material.

  13. TAML activator/peroxide-catalyzed facile oxidative degradation of the persistent explosives trinitrotoluene and trinitrobenzene in micellar solutions.

    PubMed

    Kundu, Soumen; Chanda, Arani; Khetan, Sushil K; Ryabov, Alexander D; Collins, Terrence J

    2013-05-21

    TAML activators are well-known for their ability to activate hydrogen peroxide to oxidize persistent pollutants in water. The trinitroaromatic explosives, 2,4,6-trinitrotoluene (TNT) and 1,3,5-trinitrobenzene (TNB), are often encountered together as persistent, toxic pollutants. Here we show that an aggressive TAML activator with peroxides boosts the effectiveness of the known surfactant/base promoted breakdown of TNT and transforms the surfactant induced nondestructive binding of base to TNB into an extensive multistep degradation process. Treatment of basic cationic surfactant solutions of either TNT or TNB with TAML/peroxide (hydrogen peroxide and tert-butylhydroperoxide, TBHP) gave complete pollutant removal for both in <1 h with >75% of the nitrogen and ≥20% of the carbon converted to nitrite/nitrate and formate, respectively. For TNT, the TAML advantage is to advance the process toward mineralization. Basic surfactant solutions of TNB gave the colored solutions typical of known Meisenheimer complexes which did not progress to degradation products over many hours. However with added TAML activator, the color was bleached quickly and the TNB starting compound was degraded extensively toward minerals within an hour. A slower surfactant-free TAML activator/peroxide process also degrades TNT/TNB effectively. Thus, TAML/peroxide amplification effectively advances TNT and TNB water treatment giving reason to explore the environmental applicability of the approach.

  14. 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.

  15. Antioxidative effect of sesamol and related compounds on lipid peroxidation.

    PubMed

    Uchida, M; Nakajin, S; Toyoshima, S; Shinoda, M

    1996-04-01

    The effect of sesamol and 20 related compounds on the lipid peroxidation of liposomes induced by Fe(2)+, on the lipid peroxidation of rat liver microsomes induced by CCl(4) or NADPH and on the lipid peroxidation of mitochondria induced by ascorbate/Fe(2)+ were demonstrated. Consequently, sesamol and related compounds, such as 3-methoxy-4-hydroxyquinone, isosafrol, isoeugenol, eugenol, 3,4-methylenedioxyaniline, catechol, hydroxy-hydroquinone, 3,4-dimethoxyaniline and caffeic acid, exhibited powerful inhibitory effects on the lipid peroxidation system investigated. In particular, isoeugenol was the most powerful inhibitor among all the sesamol-related compounds tested on the lipid peroxidation system. In addition, 1,2-methylenedioxybenzene, ferulic acid, and 3,4-methylenedioxynitrobenzene were also effective on the lipid peroxidation system of liposomes induced by Fe(2)+. The correlation between the structures of sesamol-related compounds and their inhibitory effect is discussed.

  16. Bactericidal Efficacy of Hydrogen Peroxide-Based Disinfectants Against Gram-Positive and Gram-Negative Bacteria on Stainless Steel Surfaces.

    PubMed

    Ríos-Castillo, Abel G; González-Rivas, Fabián; Rodríguez-Jerez, José J

    2017-10-01

    In order to develop disinfectant formulations that leverage the effectiveness of hydrogen peroxide (H 2 O 2 ), this study evaluated the bactericidal efficacy of hydrogen peroxide-based disinfectants against Gram-positive and Gram-negative bacteria on stainless steel surfaces. Low concentration of hydrogen peroxide as 0.5% with a cationic polymer, ethoxylated fatty alcohol, and ethyl alcohol had bactericidal efficacy (reductions ≥ 4 log 10 CFU/mL) against Escherichia coli, Staphylococcus aureus, Enterococcus hirae, and Pseudomonas aeruginosa. Hydrogen peroxide-based disinfectants were more effective against E. hirae and P. aeruginosa than to S. aureus. However, the efficacy of hydrogen peroxide against catalase positive bacteria such as S. aureus was increased when this compound was formulated with low concentrations of benzalkonium chloride or ethyl alcohol, lactic acid, sodium benzoate, cationic polymer, and salicylic acid. This study demonstrates that the use of hydrogen peroxide with other antimicrobial products, in adequate concentrations, had bactericidal efficacy in Gram-positive and Gram-negative bacteria on stainless steel surfaces, enabling to reduce the effective concentration of hydrogen peroxide. In the same way, the use of hydrogen peroxide-based disinfectants could reduce the concentrations of traditional disinfectants as quaternary ammonium compounds and therefore a reduction of their chemical residues in the environment after being used. The study of the bactericidal properties of environmentally nontoxic disinfectants such as hydrogen peroxide, sole or in formulations with other disinfectants against Gram-positive and Gram-negative bacteria can enhance the efficacy of various commonly used disinfectant formulations with the hygiene benefits that it entails. Also, the use of hydrogen peroxide formulations can reduce the concentration levels of products that generate environmental residues. © 2017 Institute of Food Technologists®.

  17. Quantification of peroxide ion passage in dentin, enamel, and cementum after internal bleaching with hydrogen peroxide.

    PubMed

    Palo, R M; Bonetti-Filho, I; Valera, M C; Camargo, C H R; Camargo, Sea; Moura-Netto, C; Pameijer, C

    2012-01-01

    The aim of this study was to evaluate the amount of peroxide passage from the pulp chamber to the external enamel surface during the internal bleaching technique. Fifty bovine teeth were sectioned transversally 5 mm below the cemento-enamel junction (CEJ), and the remaining part of the root was sealed with a 2-mm layer of glass ionomer cement. The external surface of the samples was coated with nail varnish, with the exception of standardized circular areas (6-mm diameter) located on the enamel, exposed dentin, or cementum surface of the tooth. The teeth were divided into three experimental groups according to exposed areas close to the CEJ and into two control groups (n=10/group), as follows: GE, enamel exposure area; GC, cementum exposed area; GD, dentin exposed area; Negative control, no presence of internal bleaching agent and uncoated surface; and Positive control, pulp chamber filled with bleaching agent and external surface totally coated with nail varnish. The pulp chamber was filled with 35% hydrogen peroxide (Opalescence Endo, Ultradent). Each sample was placed inside of individual flasks with 1000 μL of acetate buffer solution, 2 M (pH 4.5). After seven days, the buffer solution was transferred to a glass tube, in which 100 μL of leuco-crystal violet and 50 μL of horseradish peroxidase were added, producing a blue solution. The optical density of the blue solution was determined by spectrophotometer and converted into microgram equivalents of hydrogen peroxide. Data were submitted to Kruskal-Wallis and Dunn-Bonferroni tests (α=0.05). All experimental groups presented passage of peroxide to the external surface that was statistically different from that observed in the control groups. It was verified that the passage of peroxide was higher in GD than in GE (p<0.01). The GC group presented a significantly lower peroxide passage than did GD and GE (p<0.01). It can be concluded that the hydrogen peroxide placed into the pulp chamber passed through the

  18. Synthesis and thermal properties of strontium and calcium peroxides

    NASA Technical Reports Server (NTRS)

    Philipp, Warren H.; Kraft, Patricia A.

    1989-01-01

    A practical synthesis and a discussion of some chemical properties of pure strontium peroxide and calcium peroxide are presented. The general synthesis of these peroxides involves precipitation of their octahydrates by addition of H2O2 to aqueous ammoniacal Sr(NO3)2 or CaCl2. The octahydrates are converted to the anhydrous peroxides by various dehydration techniques. A new x-ray diffraction powder pattern for CaO2 x 8H2O is given from which lattice parameters a=6.212830 and c=11.0090 were calculated on the basis of the tetragonal crystal system.

  19. Hydrogen peroxide stimulates activity and alters behavior in Drosophila melanogaster.

    PubMed

    Grover, Dhruv; Ford, Daniel; Brown, Christopher; Hoe, Nicholas; Erdem, Aysen; Tavaré, Simon; Tower, John

    2009-10-28

    Circadian rhythms in animals are regulated at the level of individual cells and by systemic signaling to coordinate the activities of multiple tissues. The circadian pacemakers have several physiological outputs, including daily locomotor rhythms. Several redox-active compounds have been found to function in regulation of circadian rhythms in cells, however, how particular compounds might be involved in regulating specific animal behaviors remains largely unknown. Here the effects of hydrogen peroxide on Drosophila movement were analyzed using a recently developed three-dimensional real-time multiple fly tracking assay. Both hydrogen peroxide feeding and direct injection of hydrogen peroxide caused increased adult fly locomotor activity. Continuous treatment with hydrogen peroxide also suppressed daily locomotor rhythms. Conditional over-expression of the hydrogen peroxide-producing enzyme superoxide dismutase (SOD) also increased fly activity and altered the patterns of locomotor activity across days and weeks. The real-time fly tracking system allowed for detailed analysis of the effects of these manipulations on behavior. For example, both hydrogen peroxide feeding and SOD over-expression increased all fly motion parameters, however, hydrogen peroxide feeding caused relatively more erratic movement, whereas SOD over-expression produced relatively faster-moving flies. Taken together, the data demonstrate that hydrogen peroxide has dramatic effects on fly movement and daily locomotor rhythms, and implicate hydrogen peroxide in the normal control of these processes.

  20. Hydrogen Peroxide Stimulates Activity and Alters Behavior in Drosophila melanogaster

    PubMed Central

    Grover, Dhruv; Ford, Daniel; Brown, Christopher; Hoe, Nicholas; Erdem, Aysen; Tavaré, Simon; Tower, John

    2009-01-01

    Circadian rhythms in animals are regulated at the level of individual cells and by systemic signaling to coordinate the activities of multiple tissues. The circadian pacemakers have several physiological outputs, including daily locomotor rhythms. Several redox-active compounds have been found to function in regulation of circadian rhythms in cells, however, how particular compounds might be involved in regulating specific animal behaviors remains largely unknown. Here the effects of hydrogen peroxide on Drosophila movement were analyzed using a recently developed three-dimensional real-time multiple fly tracking assay. Both hydrogen peroxide feeding and direct injection of hydrogen peroxide caused increased adult fly locomotor activity. Continuous treatment with hydrogen peroxide also suppressed daily locomotor rhythms. Conditional over-expression of the hydrogen peroxide-producing enzyme superoxide dismutase (SOD) also increased fly activity and altered the patterns of locomotor activity across days and weeks. The real-time fly tracking system allowed for detailed analysis of the effects of these manipulations on behavior. For example, both hydrogen peroxide feeding and SOD over-expression increased all fly motion parameters, however, hydrogen peroxide feeding caused relatively more erratic movement, whereas SOD over-expression produced relatively faster-moving flies. Taken together, the data demonstrate that hydrogen peroxide has dramatic effects on fly movement and daily locomotor rhythms, and implicate hydrogen peroxide in the normal control of these processes. PMID:19862323

  1. Antioxidant effect of bisphosphonates and simvastatin on chondrocyte lipid peroxidation

    SciTech Connect

    Dombrecht, E.J.; De Tollenaere, C.B.; Aerts, K.

    2006-09-22

    The objective of this study was to evaluate the effect of bisphosphonates (BPs) and simvastatin on chondrocyte lipid peroxidation. For this purpose, a flow cytometrical method using C11-BODIPY{sup 581/591} was developed to detect hydroperoxide-induced lipid peroxidation in chondrocytes. Tertiary butylhydroperoxide (t-BHP) induced a time and concentration dependent increase in chondrocyte lipid peroxidation. Addition of a Fe{sup 2+}/EDTA complex to t-BHP or hydrogen peroxide (H{sub 2}O{sub 2}) clearly enhanced lipid peroxidation. The lipophilic simvastatin demonstrated a small inhibition in the chondrocyte lipid peroxidation. None of three tested BPs (clodronate, pamidronate, and risedronate) had an effect on chondrocyte lipid peroxidation induced bymore » t-BHP. However, when Fe{sup 2+}/EDTA complex was added to t-BHP or H{sub 2}O{sub 2}, BPs inhibited the lipid peroxidation process varying from 25% to 58%. This study demonstrates that BPs have antioxidant properties as iron chelators, thereby inhibiting the chondrocyte lipid peroxidation. These findings add evidence to the therapeutic potential of bisphosphonates and statins in rheumatoid arthritis.« less

  2. Effect of antioxidants and silicates on peroxides in povidone.

    PubMed

    Narang, Ajit S; Rao, Venkatramana M; Desai, Divyakant S

    2012-01-01

    Reactive peroxides in povidone often lead to degradation of oxidation-labile drugs. To reduce peroxide concentration in povidone, the roles of storage conditions, antioxidants, and silicates were investigated. Povidone alone and its physical mixtures with ascorbic acid, propyl gallate, sodium sulfite, butylated hydroxyanisole (BHA), or butylated hydroxytoluene (BHT) were stored at 25 °C and 40 °C, at 11%, 32%, and 50% relative humidity. In addition, povidone solution in methanol was equilibrated with silicates (silica gel and molecular sieves), followed by solvent evaporation to recover povidone powder. Peroxide concentrations in povidone were measured. The concentration of peroxides in povidone increased under very-low-humidity storage conditions. Among the antioxidants, ascorbic acid, propyl gallate, and sodium sulfite reduced the peroxide concentration in povidone, whereas BHA and BHT did not. Water solubility appeared to determine the effectiveness of antioxidants. Also, some silicates significantly reduced peroxide concentration in povidone without affecting its functionality as a tablet binder. Porosity of silicates was critical to their ability to reduce the peroxide concentration in povidone. A combination of these approaches can reduce the initial peroxide concentration in povidone and minimize peroxide growth under routine storage conditions. Copyright © 2011 Wiley-Liss, Inc.

  3. Antioxidant effect of bisphosphonates and simvastatin on chondrocyte lipid peroxidation

    SciTech Connect

    Dombrecht, E.J.; De Tollenaere, C.B.; Aerts, K.; Cos, P.; Schuerwegh, A.J.; Bridts, C.H.; Van Offel, J.F.; Ebo, D.G.; Stevens, W.J. . E-mail: immuno@ua.ac.be; De Clerck, L.S.

    2006-09-22

    The objective of this study was to evaluate the effect of bisphosphonates (BPs) and simvastatin on chondrocyte lipid peroxidation. For this purpose, a flow cytometrical method using C11-BODIPY{sup 581/591} was developed to detect hydroperoxide-induced lipid peroxidation in chondrocytes. Tertiary butylhydroperoxide (t-BHP) induced a time and concentration dependent increase in chondrocyte lipid peroxidation. Addition of a Fe{sup 2+}/EDTA complex to t-BHP or hydrogen peroxide (H{sub 2}O{sub 2}) clearly enhanced lipid peroxidation. The lipophilic simvastatin demonstrated a small inhibition in the chondrocyte lipid peroxidation. None of three tested BPs (clodronate, pamidronate, and risedronate) had an effect on chondrocyte lipid peroxidation induced by t-BHP. However, when Fe{sup 2+}/EDTA complex was added to t-BHP or H{sub 2}O{sub 2}, BPs inhibited the lipid peroxidation process varying from 25% to 58%. This study demonstrates that BPs have antioxidant properties as iron chelators, thereby inhibiting the chondrocyte lipid peroxidation. These findings add evidence to the therapeutic potential of bisphosphonates and statins in rheumatoid arthritis.

  4. 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.

  5. High Test Peroxide Incident at Stennis Space Center

    NASA Technical Reports Server (NTRS)

    Ross, R.; Sewell, D.; Cockrell, M.

    2001-01-01

    A renewed interest n hydrogen peroxide as a rocket engine propellant has created a void in the experience base since the last era of significant peroxide use. Advanced catalyst beds and high concentration formulations are currently being developed and tested in the propulsion community. Although peroxide has many positive attributes, there are situations where peroxide must be handled with extreme care. An incident occurred at NASA's Stennis Space Center (SSC) in December 2000 where a significant over pressurization event damaged facility and test hardware. A description of the event and findings of the investigation board are presented and discussed.

  6. Mechanisms of lipid peroxide formation in animal tissues

    PubMed Central

    Wills, E. D.

    1966-01-01

    1. Homogenates of rat liver, spleen, heart and kidney form lipid peroxides when incubated in vitro and actively catalyse peroxide formation in emulsions of linoleic acid or linolenic acid. 2. In liver, catalytic activity is distributed throughout the nuclear, mitochondrial and microsomal fractions and is present in the 100000g supernatant. Activity is weak in the nuclear fraction. 3. Dilute (0·5%, w/v) homogenates catalyse peroxidation over the range pH5·0–8·0 but concentrated (5%, w/v) homogenates inhibit peroxidation and destroy peroxide if the solution is more alkaline than pH7·0. 4. Ascorbic acid increases the rate of peroxidation of unsaturated fatty acids catalysed by whole homogenates of liver, heart, kidney and spleen at pH6·0 but not at pH7·4. 5. Catalysis of peroxidation of unsaturated fatty acids by the mitochondrial and microsomal fractions of liver is inhibited by ascorbic acid at pH7·4 but the activity of the supernatant fraction is enhanced. 6. Inorganic iron or ferritin are active catalysts in the presence of ascorbic acid. 7. Lipid peroxide formation in linoleic acid or linolenic acid emulsions catalysed by tissue homogenates is partially inhibited by EDTA but stimulated by o-phenanthroline. 8. Cysteine or glutathione (1mm) inhibits peroxide formation catalysed by whole homogenates, mitochondria or haemoprotein. Inhibition increases with increase of pH. PMID:5964963

  7. 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

  8. Peroxide-Sensing Transcriptional Regulators in Bacteria

    PubMed Central

    Mongkolsuk, Skorn

    2012-01-01

    The ability to maintain intracellular concentrations of toxic reactive oxygen species (ROS) within safe limits is essential for all aerobic life forms. In bacteria, as well as other organisms, ROS are produced during the normal course of aerobic metabolism, necessitating the constitutive expression of ROS scavenging systems. However, bacteria can also experience transient high-level exposure to ROS derived either from external sources, such as the host defense response, or as a secondary effect of other seemingly unrelated environmental stresses. Consequently, transcriptional regulators have evolved to sense the levels of ROS and coordinate the appropriate oxidative stress response. Three well-studied examples of these are the peroxide responsive regulators OxyR, PerR, and OhrR. OxyR and PerR are sensors of primarily H2O2, while OhrR senses organic peroxide (ROOH) and sodium hypochlorite (NaOCl). OxyR and OhrR sense oxidants by means of the reversible oxidation of specific cysteine residues. In contrast, PerR senses H2O2 via the Fe-catalyzed oxidation of histidine residues. These transcription regulators also influence complex biological phenomena, such as biofilm formation, the evasion of host immune responses, and antibiotic resistance via the direct regulation of specific proteins. PMID:22797754

  9. 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.

  10. Uranyl peroxide nanoclusters at high-pressure

    DOE PAGES

    Turner, Katlyn M.; Szymanowski, Jennifer E. S.; Zhang, Fuxiang; ...

    2017-08-14

    Here, U 60