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Sample records for acid increases oxidative

  1. Oxidation in fish oil enriched mayonnaise : Ascorbic acid and low pH increase oxidative deterioration

    DEFF Research Database (Denmark)

    Jacobsen, Charlotte; Timm Heinrich, Maike; Meyer, Anne S.

    2001-01-01

    The effect of ascorbic acid (0-4000 ppm) and pH (3.8-6.2) on oxidation and levels of iron and copper in various fractions of mayonnaise enriched with 16% fish oil was investigated. Ascorbic acid induced release of iron from the assumed oil- water interface into the aqueous phase at all pH levels......, but this effect of ascorbic acid was strongest at low pH (pH 3.8- 4.2). Ascorbic acid generally promoted formation of volatile oxidation compounds and reduced the peroxide value in mayonnaises. Peroxide values and total volatiles generally increased with decreasing pH values, suggesting that low pH promoted...... oxidation. It is proposed that iron bridges between the egg yolk proteins low-density lipoproteins, lipovitellin, and phosvitin at the oil-water interface are broken at low pH values, whereby iron ions become accessible as oxidation initiators. In the presence of ascorbic acid, oxidation is further enhanced...

  2. IDH1 mutations alter citric acid cycle metabolism and increase dependence on oxidative mitochondrial metabolism

    National Research Council Canada - National Science Library

    Grassian, Alexandra R; Parker, Seth J; Davidson, Shawn M; Divakaruni, Ajit S; Green, Courtney R; Zhang, Xiamei; Slocum, Kelly L; Pu, Minying; Lin, Fallon; Vickers, Chad; Joud-Caldwell, Carol; Chung, Franklin; Yin, Hong; Handly, Erika D; Straub, Christopher; Growney, Joseph D; Vander Heiden, Matthew G; Murphy, Anne N; Pagliarini, Raymond; Metallo, Christian M

    2014-01-01

    .... We observed that under hypoxic conditions, IDH1-mutant cells exhibited increased oxidative tricarboxylic acid metabolism along with decreased reductive glutamine metabolism, but not IDH2-mutant cells...

  3. All-trans retinoic acid increases oxidative metabolism in mature adipocytes

    DEFF Research Database (Denmark)

    Mercader, Josep; Madsen, Lise; Felipe, Francisco

    2007-01-01

    ), and to an increased expression of proteins favoring fat oxidation (peroxisome proliferator-activated receptor gamma coactivator-1alpha, uncoupling protein 2, fasting-induced adipose factor, enzymes of mitochondrial fatty acid oxidation). These changes paralleled inactivation of the retinoblastoma protein and were...

  4. All-trans retinoic acid increases oxidative metabolism in mature adipocytes

    DEFF Research Database (Denmark)

    Mercader, Josep; Madsen, Lise; Felipe, Francisco

    2007-01-01

    BACKGROUND/AIMS: In rodents, retinoic acid (RA) treatment favors loss of body fat mass and the acquisition of brown fat features in white fat depots. In this work, we sought to examine to what extent these RA effects are cell autonomous or dependent on systemic factors. METHODS: Parameters of lipid......), and to an increased expression of proteins favoring fat oxidation (peroxisome proliferator-activated receptor gamma coactivator-1alpha, uncoupling protein 2, fasting-induced adipose factor, enzymes of mitochondrial fatty acid oxidation). These changes paralleled inactivation of the retinoblastoma protein and were...

  5. Increased hepatic fatty acids uptake and oxidation by LRPPRC-driven oxidative phosphorylation reduces blood lipid levels

    Directory of Open Access Journals (Sweden)

    Ping Zhou

    2016-07-01

    Full Text Available Hyperlipidemia is one of the major risk factors of atherosclerosis and other cardiovascular diseases. This study aimed to investigate the impact of leucine rich pentatricopeptide repeat containing protein (LRPPRC-driven hepatic oxidative phoshorylation on blood lipid levels. The hepatic LRPPRC level was modulated by liver-specific transgenic or adeno-associated virus 8 carried shRNA targeting Lrpprc (aav-shLrpprc. Mice were fed with a high fat diet to induce obesity. Gene expression was analyzed by quantitative real-time PCR and / or western blot. The hepatic ATP level, hepatic and serum lipids contents, and mitochondria oxidative phosphorylation complex activities were measured using specific assay kits. The uptake and oxidation of fatty acid by hepatocytes were assessed using 14C-palmitate. LRPPRC regulated the expression of genes encoded by mitochondrial genome but not those by nuclear genome involved in mitochondria biogenesis, oxidative phosphorylation, and lipid metabolism. Increased oxidative phosphorylation in liver mediated by LRPPRC resulted in the increase of hepatic ATP level. Lrpprc promoted palmitate uptake and oxidation by hypatocytes. The hepatic and serum triglyceride and total cholesterol levels were inversely associated with the hepatic LRPPRC level. These data demonstrated that LRPPRC-driven hepatic oxidative phosphorylation could promote fatty acids uptake and oxidation by hepatocytes and reduce both hepatic and circulating triglyceride and cholesterol levels.

  6. Ncb5or Deficiency Increases Fatty Acid Catabolism and Oxidative Stress*

    OpenAIRE

    Xu, Ming; Wang, Wenfang; Frontera, Jennifer R.; Neely, Melanie C.; Lu, Jianghua; Aires, Daniel; Hsu, Fong-Fu; Turk, John; Swerdlow, Russell H.; Carlson, Susan E; Zhu, Hao

    2011-01-01

    The endoplasmic reticulum-associated NADH cytochrome b5 oxidoreductase (Ncb5or) is widely distributed in animal tissues. Ncb5or−/− mice develop diabetes at age 7 weeks and have increased susceptibility to the diabetogenic oxidant streptozotocin. Ncb5or deficiency also results in lipoatrophy and increased hepatocyte sensitivity to cytotoxic effects of saturated fatty acids. Here we investigate the mechanisms of these phenomena in prediabetic Ncb5or−/− mice and find that, despite increased rate...

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

    Science.gov (United States)

    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.

  8. Increasing fatty acid oxidation remodels the hypothalamic neurometabolome to mitigate stress and inflammation.

    Directory of Open Access Journals (Sweden)

    Joseph W McFadden

    Full Text Available Modification of hypothalamic fatty acid (FA metabolism can improve energy homeostasis and prevent hyperphagia and excessive weight gain in diet-induced obesity (DIO from a diet high in saturated fatty acids. We have shown previously that C75, a stimulator of carnitine palmitoyl transferase-1 (CPT-1 and fatty acid oxidation (FAOx, exerts at least some of its hypophagic effects via neuronal mechanisms in the hypothalamus. In the present work, we characterized the effects of C75 and another anorexigenic compound, the glycerol-3-phosphate acyltransferase (GPAT inhibitor FSG67, on FA metabolism, metabolomics profiles, and metabolic stress responses in cultured hypothalamic neurons and hypothalamic neuronal cell lines during lipid excess with palmitate. Both compounds enhanced palmitate oxidation, increased ATP, and inactivated AMP-activated protein kinase (AMPK in hypothalamic neurons in vitro. Lipidomics and untargeted metabolomics revealed that enhanced catabolism of FA decreased palmitate availability and prevented the production of fatty acylglycerols, ceramides, and cholesterol esters, lipids that are associated with lipotoxicity-provoked metabolic stress. This improved metabolic signature was accompanied by increased levels of reactive oxygen species (ROS, and yet favorable changes in oxidative stress, overt ER stress, and inflammation. We propose that enhancing FAOx in hypothalamic neurons exposed to excess lipids promotes metabolic remodeling that reduces local inflammatory and cell stress responses. This shift would restore mitochondrial function such that increased FAOx can produce hypothalamic neuronal ATP and lead to decreased food intake and body weight to improve systemic metabolism.

  9. Overexpression of PGC-1α Increases Fatty Acid Oxidative Capacity of Human Skeletal Muscle Cells

    Directory of Open Access Journals (Sweden)

    Nataša Nikolić

    2012-01-01

    Full Text Available We investigated the effects of PGC-1α (peroxisome proliferator-activated receptor γ coactivator-1α overexpression on the oxidative capacity of human skeletal muscle cells ex vivo. PGC-1α overexpression increased the oxidation rate of palmitic acid and mRNA expression of genes regulating lipid metabolism, mitochondrial biogenesis, and function in human myotubes. Basal and insulin-stimulated deoxyglucose uptake were decreased, possibly due to upregulation of PDK4 mRNA. Expression of fast fiber-type gene marker (MHCIIa was decreased. Compared to skeletal muscle in vivo, PGC-1α overexpression increased expression of several genes, which were downregulated during the process of cell isolation and culturing. In conclusion, PGC-1α overexpression increased oxidative capacity of cultured myotubes by improving lipid metabolism, increasing expression of genes involved in regulation of mitochondrial function and biogenesis, and decreasing expression of MHCIIa. These results suggest that therapies aimed at increasing PGC-1α expression may have utility in treatment of obesity and obesity-related diseases.

  10. Raspberry ketone increases both lipolysis and fatty acid oxidation in 3T3-L1 adipocytes.

    Science.gov (United States)

    Park, Kyoung Sik

    2010-10-01

    Raspberry ketone (RK) is a natural phenolic compound of the red raspberry. The dietary administration of RK to male mice has been reported to prevent high-fat diet-induced elevation in body weight and to increase lipolysis in white adipocytes. To elucidate a possible mechanism for the antiobesity action of RK, its effects on the expression and the secretion of adiponectin, lipolysis, and fatty acid oxidation in 3T3-L1 were investigated. Treatment with 10 µM of RK increased lipolysis significantly in differentiated 3T3-L1 cells. An immunoassay showed that RK increased both the expression and the secretion of adiponectin, an adipocytokine mainly expressed and secreted by adipose tissue. In addition, treatment with 10 µM of RK increased the fatty acid oxidation and suppressed lipid accumulation in 3T3-L1 adipocytes. These findings suggest that RK holds great promise as an herbal medicine since its biological activities alter the lipid metabolism in 3T3-L1 adipocytes. © Georg Thieme Verlag KG Stuttgart · New York.

  11. Plasma acylcarnitine profiling indicates increased fatty acid oxidation relative to tricarboxylic acid cycle capacity in young, healthy low birth weight men

    DEFF Research Database (Denmark)

    Ribel-Madsen, Amalie; Ribel-Madsen, Rasmus; Brøns, Charlotte

    2016-01-01

    oxidation relative to the tricarboxylic acid cycle flux. Also, they had higher C6‐DC, C10‐OH/C8‐DC, and total hydroxyl‐/dicarboxyl‐acylcarnitine levels, which may suggest an increased fatty acid omega‐oxidation in the liver. Furthermore, LBW and NBW men decreased several acylcarnitine levels in response...... additionally tended to be negatively associated with the hepatic insulin resistance index. This indicates that an increased fatty acid omega‐oxidation could be a compensatory mechanism to prevent an accumulation of lipid species that impair insulin signaling.......We hypothesized that an increased, incomplete fatty acid beta‐oxidation in mitochondria could be part of the metabolic events leading to insulin resistance and thereby an increased type 2 diabetes risk in low birth weight (LBW) compared with normal birth weight (NBW) individuals. Therefore, we...

  12. Fish oil at low dietary levels enhances physiological activity of sesamin to increase hepatic fatty acid oxidation in rats.

    Science.gov (United States)

    Ide, Takashi

    2012-11-01

    We previously demonstrated that a diet containing fish oil at a level of 80 g/kg strongly stimulated the physiological activity of a sesame sesamin preparation containing sesamin and episesamin at equal amounts to increase hepatic fatty acid oxidation. This study was conducted to clarify whether fish oil at lower dietary levels enhances the physiological activity of sesamin to increase hepatic fatty acid oxidation. Rats were fed experimental diets supplemented with 0 or 2 g sesamin/kg, and containing 0, 15 or 30 g fish oil/kg for 15 days. Among rats fed sesamin-free diets, diets containing 15 and 30 g fish oil/kg slightly increased the activity of enzymes involved in hepatic fatty acid oxidation. Sesamin increased these values irrespective of the presence or absence of fish oil in diets; however, the extent of the increase of many parameters was much greater in rats given fish oil-containing diets than in those fed a fish oil-free diet. Diets simultaneously containing sesamin and fish oil increased the gene expression of various peroxisomal fatty acid oxidation enzymes in a synergistic manner; but they were ineffective in causing a synergistic increase in mRNA levels of mitochondrial fatty acid oxidation enzymes. The extent of the synergistic increase in the activity of hepatic fatty acid oxidation enzymes and mRNA levels of the peroxisomal enzymes was indistinguishable between diets containing 15 and 30 g fish oil/kg and appeared comparable to that observed previously with a diet containing 80 g fish oil/kg.

  13. Thyroid hormone reverses aging-induced myocardial fatty acid oxidation defects and improves the response to acutely increased afterload.

    Directory of Open Access Journals (Sweden)

    Dolena Ledee

    Full Text Available Subclinical hypothyroidism occurs during aging in humans and mice and may contribute to the development of heart failure. Aging also impairs myocardial fatty acid oxidation, causing increased reliance on flux through pyruvate dehydrogenase (PDH to maintain function. We hypothesize that the metabolic changes in aged hearts make them less tolerant to acutely increased work and that thyroid hormone supplementation reverses these defects.Studies were performed on young (Young, 4-6 months and aged (Old, 22-24 months C57/BL6 mice at standard (50 mmHg and high afterload (80 mmHg. Another aged group received thyroid hormone for 3 weeks (Old-TH, high afterload only. Function was measured in isolated working hearts along with substrate fractional contributions (Fc to the citric acid cycle (CAC using perfusate with (13C labeled lactate, pyruvate, glucose and unlabeled palmitate and insulin.Old mice maintained cardiac function under standard workload conditions, despite a marked decrease in unlabeled (presumably palmitate Fc and relatively similar individual carbohydrate contributions. However, old mice exhibited reduced palmitate oxidation with diastolic dysfunction exemplified by lower -dP/dT. Thyroid hormone abrogated the functional and substrate flux abnormalities in aged mice.The aged heart shows diminished ability to increase cardiac work due to substrate limitations, primarily impaired fatty acid oxidation. The heart accommodates slightly by increasing efficiency through oxidation of carbohydrate substrates. Thyroid hormone supplementation in aged mice significantly improves cardiac function potentially through restoration of fatty acid oxidation.

  14. Oleic acid increases mitochondrial reactive oxygen species production and decreases endothelial nitric oxide synthase activity in cultured endothelial cells

    NARCIS (Netherlands)

    Gremmels, Hendrik; Bevers, Lonneke M.; Fledderus, Joost O.; Braam, Branko; Jan Van Zonneveld, Anton; Verhaar, Marianne C.; Joles, Jaap A.

    2015-01-01

    Elevated plasma levels of free fatty acids (FFA) are associated with increased cardiovascular risk. This may be related to FFA-induced elevation of oxidative stress in endothelial cells. We hypothesized that, in addition to mitochondrial production of reactive oxygen species, endothelial nitric

  15. Acid leaching of oxide-sulphide copper ore prior the flotation: A way for an increased metal recovery

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    Sokić Miroslav D.

    2015-01-01

    Full Text Available Copper mine "Cerovo"- East Serbia as well as the other ore bodies in its vicinity contain a significant amount of oxide copper minerals in their uper layers (>40%. Processing of such mixed ores by the existing concentration technologies leads to a substantial copper losses (<60%. Reduction of "oxide copper", by acid leaching prior the flotation concentration, can increase the overall copper efficiency up to more than 70% in the single-stage leaching, achieving an efficiency in the flotation concentration stage higher than 75%. Based on the performed experimental results the flow sheet for processing of the mixed oxide-sulphide copper ore is proposed.

  16. Engineering the Saccharomyces cerevisiae β-oxidation pathway to increase medium chain fatty acid production as potential biofuel.

    Science.gov (United States)

    Chen, Liwei; Zhang, Jianhua; Chen, Wei Ning

    2014-01-01

    Fatty acid-derived biofuels and biochemicals can be produced in microbes using β-oxidation pathway engineering. In this study, the β-oxidation pathway of Saccharomyces cerevisiae was engineered to accumulate a higher ratio of medium chain fatty acids (MCFAs) when cells were grown on fatty acid-rich feedstock. For this purpose, the haploid deletion strain Δpox1 was obtained, in which the sole acyl-CoA oxidase encoded by POX1 was deleted. Next, the POX2 gene from Yarrowia lipolytica, which encodes an acyl-CoA oxidase with a preference for long chain acyl-CoAs, was expressed in the Δpox1 strain. The resulting Δpox1 [pox2+] strain exhibited a growth defect because the β-oxidation pathway was blocked in peroxisomes. To unblock the β-oxidation pathway, the gene CROT, which encodes carnitine O-octanoyltransferase, was expressed in the Δpox1 [pox2+] strain to transport the accumulated medium chain acyl-coAs out of the peroxisomes. The obtained Δpox1 [pox2+, crot+] strain grew at a normal rate. The effect of these genetic modifications on fatty acid accumulation and profile was investigated when the strains were grown on oleic acids-containing medium. It was determined that the engineered strains Δpox1 [pox2+] and Δpox1 [pox2+, crot+] had increased fatty acid accumulation and an increased ratio of MCFAs. Compared to the wild-type (WT) strain, the total fatty acid production of the strains Δpox1 [pox2+] and Δpox1 [pox2+, crot+] were increased 29.5% and 15.6%, respectively. The intracellular level of MCFAs in Δpox1 [pox2+] and Δpox1 [pox2+, crot+] increased 2.26- and 1.87-fold compared to the WT strain, respectively. In addition, MCFAs in the culture medium increased 3.29-fold and 3.34-fold compared to the WT strain. These results suggested that fatty acids with an increased MCFAs ratio accumulate in the engineered strains with a modified β-oxidation pathway. Our approach exhibits great potential for transforming low value fatty acid-rich feedstock into high

  17. THYROID HORMONE REVERSES AGING-INDUCED MYOCARDIAL FATTY ACID OXIDATION DEFECTS AND IMPROVES THE RESPONSE TO ACUTELY INCREASED AFTERLOAD

    Energy Technology Data Exchange (ETDEWEB)

    Ledee, Dolena; Portman, Michael A.; Kajimoto, Masaki; Isern, Nancy G.; Olson, Aaron

    2013-06-07

    Background: Subclinical hypothyroidism occurs during aging in humans and mice and may contribute to development of heart failure. Aging also impairs myocardial fatty acid oxidation, causing increased reliance on flux through pyruvate dehydrogenase (PDH) to maintain function. We hypothesize that the metabolic changes in aged hearts make them less tolerant to acutely increased work and that thyroid hormone reverses these defects. Methods: Studies were performed on young (Young, 4-6 months) and aged (Old, 22-24 months) C57/BL6 mice at standard (50 mmHg) and high afterload (80 mmHg). Another aged group received thyroid hormone for 3 weeks (Old-TH, high afterload only). Function was measured in isolated working hearts along with substrate fractional contributions (Fc) to the citric acid cycle (CAC) using perfusate with 13C labeled lactate, pyruvate, glucose and unlabeled palmitate and insulin. Results: Cardiac function was similar between Young and Old mice at standard afterload. Palmitate Fc was reduced but no individual carbohydrate contributions differed. CAC and individual substrate fluxes decreased in aged. At high afterload, -dP/dT was decreased in Old versus Young. Similar to low afterload, palmitate Fc was decreased in Old. Thyroid hormone reversed aging-induced changes in palmitate Fc and flux while significantly improving cardiac function. Conclusion: The aged heart shows diminished ability to increase cardiac work due to substrate limitations, primarily impaired fatty acid oxidation. The heart accommodates slightly by increasing efficiency through oxidation of carbohydrate substrates. Thyroid hormone supplementation in aged mice significantly improves cardiac function potentially through restoration of fatty acid oxidation.

  18. Wounding stimulates ALLENE OXIDE SYNTHASE gene and increases the level of jasmonic acid in Ipomoea nil cotyledons

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    Emilia Wilmowicz

    2016-03-01

    Full Text Available Allene oxide synthase (AOS encodes the first enzyme in the lipoxygenase pathway, which is responsible for jasmonic acid (JA formation. In this study we report the molecular cloning and characterization of InAOS from Ipomoea nil. The full-length gene is composed of 1662 bp and encodes for 519 amino acids. The predicted InAOS contains PLN02648 motif, which is evolutionarily conserved and characteristic for functional enzymatic proteins. We have shown that wounding led to a strong stimulation of the examined gene activity in cotyledons and an increase in JA level, which suggest that this compound may be a modulator of stress responses in I. nil.

  19. Probucol increases striatal glutathione peroxidase activity and protects against 3-nitropropionic acid-induced pro-oxidative damage in rats.

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    Dirleise Colle

    Full Text Available Huntington's disease (HD is an autosomal dominantly inherited neurodegenerative disease characterized by symptoms attributable to the death of striatal and cortical neurons. The molecular mechanisms mediating neuronal death in HD involve oxidative stress and mitochondrial dysfunction. Administration of 3-nitropropionic acid (3-NP, an irreversible inhibitor of the mitochondrial enzyme succinate dehydrogenase, in rodents has been proposed as a useful experimental model of HD. This study evaluated the effects of probucol, a lipid-lowering agent with anti-inflammatory and antioxidant properties, on the biochemical parameters related to oxidative stress, as well as on the behavioral parameters related to motor function in an in vivo HD model based on 3-NP intoxication in rats. Animals were treated with 3.5 mg/kg of probucol in drinking water daily for 2 months and, subsequently, received 3-NP (25 mg/kg i.p. once a day for 6 days. At the end of the treatments, 3-NP-treated animals showed a significant decrease in body weight, which corresponded with impairment on motor ability, inhibition of mitochondrial complex II activity and oxidative stress in the striatum. Probucol, which did not rescue complex II inhibition, protected against behavioral and striatal biochemical changes induced by 3-NP, attenuating 3-NP-induced motor impairments and striatal oxidative stress. Importantly, probucol was able to increase activity of glutathione peroxidase (GPx, an enzyme important in mediating the detoxification of peroxides in the central nervous system. The major finding of this study was that probucol protected against 3-NP-induced behavioral and striatal biochemical changes without affecting 3-NP-induced mitochondrial complex II inhibition, indicating that long-term probucol treatment resulted in an increased resistance against neurotoxic events (i.e., increased oxidative damage secondary to mitochondrial dysfunction. These data appeared to be of great

  20. Overexpression of carnitine palmitoyltransferase I in skeletal muscle in vivo increases fatty acid oxidation and reduces triacylglycerol esterification

    NARCIS (Netherlands)

    Bruce, Clinton R.; Brolin, Camilla; Turner, Nigel; Cleasby, Mark E.; van der Leij, Feike R.; Cooney, Gregory J.; Kraegen, Edward W.

    A key regulatory point in the control of fatty acid ( FA) oxidation is thought to be transport of FAs across the mitochondrial membrane by carnitine palmitoyltransferase I (CPT I). To investigate the role of CPT I in FA metabolism, we used in vivo electrotransfer (IVE) to locally overexpress CPT I

  1. PEGylated single-walled carbon nanotubes activate neutrophils to increase production of hypochlorous acid, the oxidant capable of degrading nanotubes.

    Science.gov (United States)

    Vlasova, Irina I; Vakhrusheva, Tatyana V; Sokolov, Alexey V; Kostevich, Valeria A; Gusev, Alexandr A; Gusev, Sergey A; Melnikova, Viktoriya I; Lobach, Anatolii S

    2012-10-01

    Perspectives for the use of carbon nanotubes in biomedical applications depend largely on their ability to degrade in the body into products that can be easily cleared out. Carboxylated single-walled carbon nanotubes (c-SWCNTs) were shown to be degraded by oxidants generated by peroxidases in the presence of hydrogen peroxide. In the present study we demonstrated that conjugation of poly(ethylene glycol) (PEG) to c-SWCNTs does not interfere with their degradation by peroxidase/H(2)O(2) system or by hypochlorite. Comparison of different heme-containing proteins for their ability to degrade PEG-SWCNTs has led us to conclude that the myeloperoxidase (MPO) product hypochlorous acid (HOCl) is the major oxidant that may be responsible for biodegradation of PEG-SWCNTs in vivo. MPO is secreted mainly by neutrophils upon activation. We hypothesize that SWCNTs may enhance neutrophil activation and therefore stimulate their own biodegradation due to MPO-generated HOCl. PEG-SWCNTs at concentrations similar to those commonly used in in vivo studies were found to activate isolated human neutrophils to produce HOCl. Both PEG-SWCNTs and c-SWCNTs enhanced HOCl generation from isolated neutrophils upon serum-opsonized zymosan stimulation. Both types of nanotubes were also found to activate neutrophils in whole blood samples. Intraperitoneal injection of a low dose of PEG-SWCNTs into mice induced an increase in percentage of circulating neutrophils and activation of neutrophils and macrophages in the peritoneal cavity, suggesting the evolution of an inflammatory response. Activated neutrophils can produce high local concentrations of HOCl, thereby creating the conditions favorable for degradation of the nanotubes. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Increased protein oxidation and loss of protein-bound sialic acid in hepatic tissues of D-galactose induced aged rats.

    Science.gov (United States)

    Cakatay, Ufuk; Aydın, Seval; Atukeren, Pınar; Yanar, Karolin; Sitar, Mustafa E; Dalo, Enis; Uslu, Ezel

    2013-07-01

    A redox basis of the increased oxidative protein damage and free radical-mediated desialylation have not been fully elucidated in aging. It is well known that the incidence of several liver diseases increase with age. This original research focuses on protein oxidation mechanisms and protein-bound sialic acid levels in liver tissue of the mimetic aging rats. Injection of D-galactose (60 mg/kg/day) for six weeks to male Sprague-Dawley rats (20-week-old) used to establish mimetic aging model. We investigated the tissue levels of various protein oxidation markers such as protein carbonyl groups, suitable advanced oxidation protein products and protein thiol groups. Our study also covered protein-bound sialic acid in liver tissue of D-galactose-induced aging rats. PCO (Protein Carbonyl Groups), P-OOH (Protein Hydroperoxides) and AOPP (Advanced Oxidation Protein Products) levels in aging rats were significantly higher compared to young control groups. On the other hand, P-SH (Protein Thiol Groups) levels were not found to be different between two groups. SA (Sialic Acid) levels in D-galactose-induced aging rats were significantly lower compared to control groups. Our results demonstrated greater susceptibility to hepatic oxidative protein damage and desialylation of hepatocellular proteins in Dgalactose- induced aging rats. These molecular mechanisms may be operative in the many age-related liver diseases, which are pertinent to increased oxidative stress and altered redox homeostasis.

  3. Rosemary distillation residues reduce lipid oxidation, increase alpha-tocopherol content and improve fatty acid profile of lamb meat.

    Science.gov (United States)

    Yagoubi, Y; Joy, M; Ripoll, G; Mahouachi, M; Bertolín, J R; Atti, N

    2018-02-01

    The experiment studied the effects of rosemary distillation residues (RR) intake on lamb meat quality, oxidative stability and fatty acid (FA) profile. Barbarine lambs of Control group were fed 600g of hay, which was substituted by 600g of pellets containing 60 and 87% of RR for RR60 and RR87 groups; all animals received 600g of concentrate. Meat protein and fat content was similar for 3 treatments. Lipid oxidation was strongly reduced with RR diets. Both RR diets resulted in a higher α- tocopherol content in muscle. The metmyoglobin and deoxymyoglobin percentages were similar for all groups; however oxymyoglobin was higher for RR groups. The saturated (SFA) and unsaturated FAs (UFA) were unaffected by the diets. However, the PUFA, n-6 and n-3 were higher for RR groups. In conclusion, rosemary residues resulted in higher vitamin E content, so it enhanced the oxidative status and improved the fatty acid profile of lamb meat. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Leptin induces mitochondrial superoxide production and monocyte chemoattractant protein-1 expression in aortic endothelial cells by increasing fatty acid oxidation via protein kinase A.

    Science.gov (United States)

    Yamagishi, S I; Edelstein, D; Du, X L; Kaneda, Y; Guzmán, M; Brownlee, M

    2001-07-06

    Leptin, a circulating hormone secreted mainly from adipose tissues, is involved in the control of body weight. The plasma concentrations are correlated with body mass index, and are reported to be high in patients with insulin resistance, which is one of the major risk factors for cardiovascular disease. However, the direct effect of leptin on vascular wall cells is not fully understood. In this study, we investigated the effects of leptin on reactive oxygen species (ROS) generation and expression of monocyte chemoattractant protein-1 (MCP-1) in bovine aortic endothelial cells (BAEC). We found that leptin increases ROS generation in BAEC in a dose-dependent manner and that its effects are additive with those of glucose. Rotenone, thenoyltrifluoroacetone (TTFA), carbonyl cyanide m-chlorophenylhydrazone (CCCP), Mn(III)tetrakis (4-benzoic acid) porphyrin (MnTBAP), uncoupling protein-1 (UCP1) HVJ-liposomes, or manganese superoxide dismutase (MnSOD) HVJ-liposomes completely prevented the effect of leptin, suggesting that ROS arise from mitochondrial electron transport. Leptin increased fatty acid oxidation by stimulating the activity of carnitine palmitoyltransferase-1 (CPT-1) and inhibiting that of acetyl-CoA carboxylase (ACC), pace-setting enzymes for fatty acid oxidation and synthesis, respectively. Leptin-induced ROS generation, CPT-1 activation, ACC inhibition, and MCP-1 overproduction were found to be completely prevented by either genistein, a tyrosine kinase inhibitor, H-89, a protein kinase A (PKA) inhibitor, or tetradecylglycidate, a CPT-1 inhibitor. Leptin activated PKA, and the effects of leptin were inhibited by the cAMP antagonist Rp-cAMPS. These results suggest that leptin induces ROS generation by increasing fatty acid oxidation via PKA activation, which may play an important role in the progression of atherosclerosis in insulin-resistant obese diabetic patients.

  5. (VI) oxide in acetic acid

    African Journals Online (AJOL)

    The oxidation of cyclohexene by chromium (VI) oxide in aqueous and acetic media was studied. The reaction products were analysed using infra red (IR) and gas chromatography coupled with mass (GC/MS) spectroscopy. The major products of the oxidation reaction in acetic acid medium were cyclohexanol, ...

  6. Interleukin-6 deficiency reduces the brain inflammatory response and increases oxidative stress and neurodegeneration after kainic acid-induced seizures

    DEFF Research Database (Denmark)

    Penkowa, M; Molinero, A; Carrasco, J

    2001-01-01

    The role of interleukin-6 in hippocampal tissue damage after injection with kainic acid, a rigid glutamate analogue inducing epileptic seizures, has been studied by means of interleukin-6 null mice. At 35mg/kg, kainic acid induced convulsions in both control (75%) and interleukin-6 null (100%) mi...

  7. Increased postprandial nonesterified fatty acid appearance and oxidation in type 2 diabetes is not fully established in offspring of diabetic subjects.

    Directory of Open Access Journals (Sweden)

    François Normand-Lauzière

    Full Text Available BACKGROUND: It has been proposed that abnormal postprandial plasma nonesterified fatty acid (NEFA metabolism may participate in the development of tissue lipotoxicity and type 2 diabetes (T2D. We previously found that non-diabetic offspring of two parents with T2D display increased plasma NEFA appearance and oxidation rates during intravenous administration of a fat emulsion. However, it is currently unknown whether plasma NEFA appearance and oxidation are abnormal during the postprandial state in these subjects at high-risk of developing T2D. METHODOLOGY: Palmitate appearance and oxidation rates and glycerol appearance rate were determined in eleven healthy offspring of two parents with T2D (positive family history, FH+, 13 healthy subjects without first-degree relatives with T2D (FH- and 12 subjects with T2D at fasting, during normoglycemic hyperinsulinemic clamp and during continuous oral intake of a standard liquid meal to achieve steady postprandial NEFA and triacylglycerols (TG without and with insulin infusion to maintain similar glycemia in all three groups. PRINCIPAL FINDINGS: Plasma palmitate appearance and oxidation were higher at fasting and during the clamp conditions in the T2D group (all P<0.05. In the postprandial state, palmitate appearance, oxidative and non oxidative rates were all elevated in T2D (all P<0.05 but not in FH+. Both T2D and FH+ displayed elevated postprandial TG vs. FH- (P<0.001. Acute correction of hyperglycemia during the postprandial state did not affect these group differences. Increased waist circumference and BMI were positively associated with elevated postprandial plasma palmitate appearance and oxidation. CONCLUSIONS/SIGNIFICANCE: Postprandial plasma NEFA intolerance observed in subjects with T2D is not fully established in non-diabetic offspring of both parents with T2D, despite the presence of increased postprandial plasma TG in the later. Elevated postprandial plasma NEFA appearance and oxidation in T

  8. Docosahexaenoic acid increases the expression of oxidative stress-induced growth inhibitor 1 through the PI3K/Akt/Nrf2 signaling pathway in breast cancer cells.

    Science.gov (United States)

    Tsai, Chia-Han; Shen, You-Cheng; Chen, Haw-Wen; Liu, Kai-Li; Chang, Jer-Wei; Chen, Pei-Yin; Lin, Chen-Yu; Yao, Hsien-Tsung; Li, Chien-Chun

    2017-10-01

    Oxidative stress-induced growth inhibitor 1 (OSGIN1), a tumor suppressor, inhibits cell proliferation and induces cell death. N-6 and n-3 PUFAs protect against breast cancer, but the molecular mechanisms of this effect are not clear. We investigated the effect of n-6 and n-3 PUFAs on OSGIN1 expression and whether OSGIN1 is involved in PUFA-induced apoptosis in breast cancer cells. We used 100 μM of n-6 PUFAs including arachidonic acid, linoleic acid, and gamma-linolenic acid and n-3 PUFAs including alpha-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid (DHA). Only DHA significantly induced OSGIN1 protein and mRNA expression. DHA triggered reactive oxygen species (ROS) generation and nuclear translocation of Nrf2. LY294002, a PI3K inhibitor, suppressed DHA-induced OSGIN1 protein expression and nuclear accumulation of Nrf2. Nrf2 knockdown attenuated DHA-induced OSGIN1 expression. N-Acetyl-l-cysteine, a ROS scavenger, abrogated the DHA-induced increases in Akt phosphorylation, Nrf2 nuclear accumulation, and OSGIN1 expression. DHA induced the Bax/Bcl-2 ratio, mitochondrial accumulation of OSGIN1 and p53, and cytochrome c release; knockdown of OSGIN1 diminished these effects. In conclusion, induction of OSGIN1 by DHA is at least partially associated with increased ROS production, which activates PI3K/Akt/Nrf2 signaling. Induction of OSGIN1 may be involved in DHA-induced apoptosis in breast cancer cells. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Jasmonic acid does not increase oxidative defense mechanisms or common defense-related enzymes in postharvest sugarbeet roots

    Science.gov (United States)

    Jasmonic acid (JA) treatment significantly reduces rot due to several sugarbeet (Beta vulgaris L.) storage pathogens. However, the mechanisms by which JA protects postharvest sugarbeet roots from disease are unknown. In other plant species and organs, alterations in antioxidant defense mechanisms ...

  10. Pyocyanin and its precursor phenazine-1-carboxylic acid increase IL-8 and intercellular adhesion molecule-1 expression in human airway epithelial cells by oxidant-dependent mechanisms.

    Science.gov (United States)

    Look, Dwight C; Stoll, Lynn L; Romig, Sara A; Humlicek, Alicia; Britigan, Bradley E; Denning, Gerene M

    2005-09-15

    Pseudomonas aeruginosa secretes numerous factors that alter host cell function and may contribute to disease pathogenesis. Among recognized virulence factors is the redox-active phenazine pyocyanin. We have recently demonstrated that the precursor for pyocyanin, phenazine-1-carboxylic acid (PCA), increases oxidant formation and alters gene expression in human airway epithelial cells. We report in this work that PCA and pyocyanin increase expression of ICAM-1 both in vivo and in vitro. Moreover, phenazines enhanced cytokine-dependent increases in IL-8 and ICAM-1. Antioxidant intervention studies indicated both similarities and differences between PCA and pyocyanin. The thiol antioxidant N-acetyl cysteine, extracellular catalase, and inducible NO synthase inhibitors inhibited ICAM-1 and IL-8 increases in response to both phenazines. However, pyocyanin was significantly more sensitive to N-acetylcysteine inhibition. Interestingly, hydroxyl radical scavengers inhibited the response to pyocyanin, but not to PCA. These studies suggest that P. aeruginosa phenazines coordinately up-regulate chemokines (IL-8) and adhesion molecules (ICAM-1) by mechanisms that are, at least in part, oxidant dependent. However, results indicate that the mechanisms by which PCA and pyocyanin exert their effects are not identical, and not all antioxidant interventions are equally effective in inhibiting phenazine-mediated proinflammatory effects.

  11. Oxidation of phenolic acids by soil iron and manganese oxides

    Energy Technology Data Exchange (ETDEWEB)

    Lehmann, R.G.; Cheng, H.H.; Harsh, J.B.

    Phenolic acids are intermediary metabolites of many aromatic chemicals and may be involved in humus formation, allelopathy, and nutrient availability. Depending on their structures, six phenolic acids were shown to react at different rates with oxidized forms of Fe and Mn in a Palouse soil (fine-silty, mixed, mesic Pachic Ultic Haploxeroll). Increasing methoxy substitution on the aromatic ring of phenolic acids increased the reaction rate. Reaction rate was also increased for longer carboxyl-containing side chains. After 4 h reaction, little of the applied (10 mg kg/sup -1/ soil) p-hydroxybenzoic or p-coumaric acids had reacted, while 0 to 5, 70, 90, and 100% of the vanillic, ferulic, syringic, and sinapic acids, respectively, had reacted. After 72 h under conditions limiting microbial growth, none of the p-hydroxybenzoic, 30% of the p-coumaric, and 50% of the vanillic acids had reacted. The reaction was shown to be predominantly chemical, and not biological, since phenolic acid extractabilities were similar for Palouse soil and for Palouse soil pretreated with LiOBr to remove organic matter. When the Palouse soil was pretreated with a sodium dithionite-citrate solution to remove Fe and Mn oxides, none of the phenolic acids reacted after 1 h. The reaction of sinapic acid with Palouse soil was shown to produce Fe(II) and soluble Mn as reaction products. The reaction of phenolic acids with soil was thus shown to be an oxidation of the phenolic acids, coupled with a reduction of soil Fe and Mn oxides.

  12. Selenium dioxide catalysed oxidation of acetic acid hydrazide by ...

    Indian Academy of Sciences (India)

    Selenium dioxide catalysed acetic acid hydrazide oxidation by bromate was studied in hydrochloric acid medium. The order in oxidant concentration, substrate and catalyst were found to be unity. Increasing hydrogen ion concentration increases the rate of the reaction due to protonation equilibria of the oxidant.

  13. Effects of Uric Acid on Exercise-induced Oxidative Stress

    OpenAIRE

    平井, 富弘

    2001-01-01

    We studied effects of uric acid on exercise― induced oxidative stress in humans based on a hypothesis that uric acid acts as an antioxidant to prevent from exercise―induced oxidative stress. Relation between uric acid level in plasma and increase of thiobarbituric acid reactive substance (TBARS)after the cycle ergometer exercise was examined. Thiobarbituricacid reactive substance in plasma increased after the ergometer exercise. High uric acid in plasma did not result in low increase of TBARS...

  14. Oxidative Decarboxylation of Levulinic Acid by Cupric Oxides

    Directory of Open Access Journals (Sweden)

    Lu Lin

    2010-11-01

    Full Text Available In this paper, cupric oxides was found to effectively oxidize levulinic acid (LA and lead to the decarboxylation of levulinic acid to 2-butanone. The effects of cupric oxide dosage, reaction time and initial pH value were investigated in batch experiments and a plausible mechanism was proposed. The results showed that LA decarboxylation over cupric oxides at around 300 °C under acidic conditions produced the highest yield of butanone (67.5%. In order to elucidate the catalytic activity of cupric oxides, XRD, AFM, XPS and H2-TPR techniques was applied to examine their molecular surfaces and their effects on the reaction process.

  15. Emulsifying Property and Antioxidative Activity of Cuttlefish Skin Gelatin Modified with Oxidized Linoleic Acid and Oxidized Tannic Acid

    NARCIS (Netherlands)

    Aewsiri, T.; Benjakul, S.; Visessanguan, W.; Wierenga, P.A.; Gruppen, H.

    2013-01-01

    Cuttlefish skin gelatins modified with oxidized linoleic acid (OLA) and oxidized tannic acid (OTA) were characterized and determined for emulsifying properties and antioxidative activity. Modification of gelatin with 5% OTA increased the total phenolic content and 1,1-diphenyl-2-picrylhydrazyl,

  16. Control of bovine hepatic fatty acid oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Jesse, B.W.; Emery, R.S.; Thomas, J.W.

    1986-09-01

    Fatty acid oxidation by bovine liver slices and mitochondria was examined to determine potential regulatory sites of fatty acid oxidation. Conversion of 1-(/sup 14/C)palmitate to /sup 14/CO/sub 2/ and total (/sup 14/C)acid-soluble metabolites was used to measure fatty acid oxidation. Oxidation of palmitate (1 mM) was linear in both liver slice weight and incubation time. Carnitine stimulated palmitate oxidation; 2 mM dl-carnitine produced maximal stimulation of palmitate oxidation to both CO/sup 2/ and acid-soluble metabolites. Propionate (10 mM) inhibited palmitate oxidation by bovine liver slices. Propionate (.5 to 10 mM) had no effect on palmitate oxidation by mitochondria, but malonyl Coenzyme A, the first committed intermediate of fatty acid synthesis, inhibited mitochondrial palmitate oxidation (inhibition constant = .3 ..mu..M). Liver mitochonndrial carnitine palmitoyltransferase exhibited Michaelis constants for palmitoyl Coenzyme A and l-carnitine of 11.5 ..mu..M and .59 mM, respectively. Long-chain fatty acid oxidation in bovine liver is regulated by mechanisms similar to those in rats but adapted to the unique digestive physiology of the bovine.

  17. Kinetics of oxidation of acidic amino acids by sodium N ...

    Indian Academy of Sciences (India)

    Unknown

    Keywords. Acidic amino acids; bromamine-B; oxidation kinetics, acid medium. 1. Introduction. The chemistry of aromatic sulphonyl haloamines has evoked considerable interest, as they are sources of halonium cations, hypohalite species, and N-anions which act both as bases and nucleophiles. The prominent members of ...

  18. Kinetics of oxidation of acidic amino acids by sodium N ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 113; Issue 4. Kinetics of oxidation of acidic amino acids by sodium N-bromobenzenesulphonamide in acid medium: A mechanistic approach ... Department of Post-Graduate Studies in Chemistry, Central College, Bangalore University, Bangalore 560 001, India ...

  19. Fatty acid omega-oxidation as a rescue pathway for fatty acid oxidation disorders in humans

    NARCIS (Netherlands)

    Wanders, Ronald J. A.; Komen, Jasper; Kemp, Stephan

    2011-01-01

    Fatty acids (FAs) can be degraded via different mechanisms including alpha-, beta- and omega-oxidation. In humans, a range of different genetic diseases has been identified in which either mitochondrial FA beta-oxidation, peroxisomal FA beta-oxidation or FA alpha-oxidation is impaired. Treatment

  20. Parabanic acid is the singlet oxygen specific oxidation product of uric acid.

    Science.gov (United States)

    Iida, Sayaka; Ohkubo, Yuki; Yamamoto, Yorihiro; Fujisawa, Akio

    2017-11-01

    Uric acid quenches singlet oxygen physically or reacts with it, but the oxidation product has not been previously characterized. The present study determined that the product is parabanic acid, which was confirmed by LC/TOFMS analysis. Parabanic acid was stable at acidic pH (acid at neutral or alkaline pH. The total yields of parabanic acid and oxaluric acid based on consumed uric acid were ~100% in clean singlet oxygen production systems such as UVA irradiation of Rose Bengal and thermal decomposition of 3-(1,4-dihydro-1,4-epidioxy-4-methyl-1-naphthyl)propionic acid. However, the ratio of the amount of uric acid consumed to the total amount of singlet oxygen generated was less than 1/180, indicating that most of the singlet oxygen was physically quenched. The total yields of parabanic acid and oxaluric acid were high in the uric acid oxidation systems with hydrogen peroxide plus hypochlorite or peroxynitrite. They became less than a few percent in peroxyl radical-, hypochlorite- or peroxynitrite-induced oxidation of uric acid. These results suggest that parabanic acid could be an in vivo probe of singlet oxygen formation because of the wide distribution of uric acid in human tissues and extracellular spaces. In fact, sunlight exposure significantly increased human skin levels of parabanic acid.

  1. Wet oxidation of salicylic acid solutions.

    Science.gov (United States)

    Collado, Sergio; Garrido, Laura; Laca, Adriana; Diaz, Mario

    2010-11-15

    Salicylic acid is a frequent pollutant in several industrial wastewaters. Uncatalyzed wet air oxidation, which is a promising technique for the treatment of phenolic effluents, has not been analyzed yet for the removal of salicylic acid. The effect of different conditions of pH (1.3-12.3), pressure (1.0-4.1 MPa), temperature (413-443 K), and initial concentrations (1.45-14.50 mM) on the wet oxidation of salicylate/salicylic acid solutions have here been investigated. The pH value of the reaction media was found to be a key parameter for the rate of the oxidation process with an optimum at pH 3.1, when the concentrations of salicylic acid and salicylate were similar. The oxidation reaction followed pseudofirst-order kinetics with respect to salicylic acid and 0.82 order with respect to dissolved oxygen. Additionally, the evolution of the color during the wet oxidation was analyzed and discussed in relation with the formation of intermediate compounds. Then, a reaction pathway for the noncatalytic wet oxidation of the salicylic acid was proposed.

  2. AMPK-independent pathways regulate skeletal muscle fatty acid oxidation

    DEFF Research Database (Denmark)

    Dzamko, Nicolas; Schertzer, Jonathan D.; Ryall, James G.

    2008-01-01

    The activation of AMP-activated protein kinase (AMPK) and phosphorylation/inhibition of acetyl-CoA carboxylase 2 (ACC2) is believed to be the principal pathway regulating fatty acid oxidation. However, during exercise AMPK activity and ACC Ser-221 phosphorylation does not always correlate...... with rates of fatty acid oxidation. To address this issue we have investigated the requirement for skeletal muscle AMPK in controlling aminoimidazole-4-carboxymide-1-beta-d-ribofuranoside (AICAR) and contraction-stimulated fatty acid oxidation utilizing transgenic mice expressing a muscle-specific kinase...... dead (KD) AMPK alpha2. In wild-type (WT) mice, AICAR and contraction increased AMPK alpha2 and alpha1 activities, the phosphorylation of ACC2 and rates of fatty acid oxidation while tending to reduce malonyl-CoA levels. Despite no activation of AMPK in KD mice, ACC2 phosphorylation was maintained...

  3. Fatty acid oxidation and ketogenesis in astrocytes

    Energy Technology Data Exchange (ETDEWEB)

    Auestad, N.

    1988-01-01

    Astrocytes were derived from cortex of two-day-old rat brain and grown in primary culture to confluence. The metabolism of the fatty acids, octanoate and palmitate, to CO{sub 2} in oxidative respiration and to the formation of ketone bodies was examined by radiolabeled tracer methodology. The net production of acetoacetate was also determined by measurement of its mass. The enzymes in the ketogenic pathway were examined by measuring enzymic activity and/or by immunoblot analyses. Labeled CO{sub 2} and labeled ketone bodies were produced from the oxidation of fatty acids labeled at carboxy- and {omega}-terminal carbons, indicating that fatty acids were oxidized by {beta}-oxidation. The results from the radiolabeled tracer studies also indicated that a substantial proportion of the {omega}-terminal 4-carbon unit of the fatty acids bypassed the {beta}-ketothiolase step of the {beta}-oxidation pathway. The ({sup 14}C)acetoacetate formed from the (1-{sup 14}C)labeled fatty acids, obligated to pass through the acetyl-CoA pool, contained 50% of the label at carbon 3 and 50% at carbon 1. In contrast, the ({sup 14}C)acetoacetate formed from the ({omega}-1)labeled fatty acids contained 90% of the label at carbon 3 and 10% at carbon 1.

  4. Investigation of Influential Parameters in Deep Oxidative Desulfurization of Dibenzothiophene with Hydrogen Peroxide and Formic Acid

    OpenAIRE

    Alireza Haghighat Mamaghani; Shohreh Fatemi; Mehrdad Asgari

    2013-01-01

    An effective oxidative system consisting of hydrogen peroxide, formic acid, and sulfuric acid followed by an extractive stage were implemented to remove dibenzothiophene in the simulated fuel oil. The results revealed such a great performance in the case of H2O2 in the presence of formic and sulfuric acids that led to the removal of sulfur compounds. Sulfuric acid was employed to increase the acidity of media as well as catalytic activity together with formic acid. The oxidation reaction was ...

  5. Oxidative stability of fatty acid alkyl esters: a review.

    Directory of Open Access Journals (Sweden)

    Michal Angelovič

    2015-12-01

    performance. Biodiesels are more susceptible to degradation compared to fossil diesel because of the presence of unsaturated fatty acid chain in it. The mechanisms of oxidative degradation are autoxidation in presence of atmospheric oxygen; thermal or thermal-oxidative degradation from excess heat; hydrolysis in presence of moisture or water during storage and in fuel lines; and microbial contamination from contact with dust particles or water droplets containing fungi or bacteria into the fuel. The oxidation of lipids is a complex process in which unsaturated fatty acids are reacted with molecular oxygen by means of free radicals. The radicals react with lipids, and cause oxidative destruction of unsaturated, polyunsaturated fatty acids, therefore, known as lipid peroxidation. The factors such as heat, oxygen, light, and some metal ions, especially iron and copper, also play a significant role in creating oxidation. Oxidative products formed in biodiesel affect fuel storage life, contribute to deposit formation in tanks, and they may cause clogging of fuel filters and injection systems. The volatile organic acids formed as secondary by products of the oxidative degradation, may stimulate corrosion in the fuel system. Poor stability can lead to increasing acid numbers, increasing fuel viscosity, and the formation of gums and sediments. In general, antioxidants can prevent oxidation. Biodiesel, because it contains large numbers of molecules with double bonds, is much less oxidatively stable than petroleum-based diesel fuel. Oxidation stability is the important parameter to determine the storage of biodiesel for longer period of time. Biodiesel samples were evaluated according to methods on the base of kept in contact with pure oxygen at elevated temperatures and pressures. The results show that the performance antioxidants variation is observed for biodiesel. The most commonly used primary synthetic antioxidants

  6. Bezafibrate in skeletal muscle fatty acid oxidation disorders

    DEFF Research Database (Denmark)

    Ørngreen, Mette Cathrine; Madsen, Karen Lindhardt; Preisler, Nicolai

    2014-01-01

    OBJECTIVE: To assess whether bezafibrate increases fatty acid oxidation (FAO) and lowers heart rate (HR) during exercise in patients with carnitine palmitoyltransferase (CPT) II and very long-chain acyl-CoA dehydrogenase (VLCAD) deficiencies. METHODS: This was a 3-month, randomized, double......, triglyceride, and free fatty acid concentrations; however, there were no changes in palmitate oxidation, FAO, or HR during exercise. CONCLUSION: Bezafibrate does not improve clinical symptoms or FAO during exercise in patients with CPT II and VLCAD deficiencies. These findings indicate that previous in vitro...

  7. Fatty acid omega‐oxidation as a rescue pathway for fatty acid oxidation disorders in humans

    National Research Council Canada - National Science Library

    Wanders, Ronald J. A; Komen, Jasper; Kemp, Stephan

    2011-01-01

    Fatty acids (FAs) can be degraded via different mechanisms including α‐, β‐ and ω‐oxidation. In humans, a range of different genetic diseases has been identified in which either mitochondrial FA...

  8. Effect of ascorbic and folic acids supplementation on oxidative ...

    African Journals Online (AJOL)

    An experiment was conducted on the effect of supplementation of ascorbic and folic acids on the oxidative hormones, enzymatic antioxidants, haematological and biochemical properties of layers exposed to increased heat load. A total of 72 Isa Brown laying hens at 31 weeks of age were randomly divided into four groups ...

  9. Aumento del contenido de ácidos húmicos en un carbón de bajo rango a través de la oxidación con aire y con peróxido de hidrogeno o ácido nítrico Increase of the content of humic acids in a low rank coal by oxidation with air and with hydrogen peroxide or nitric acid

    Directory of Open Access Journals (Sweden)

    Ruben Anillo-Correa

    2013-01-01

    Full Text Available Low-rank coals are an important source of humic acids, which are important in retention processes of water and nutrients in plants. In this study coal samples of Montelibano, Colombia, were oxidized with air at different temperatures and subsequently with H2O2 and HNO3. The materials were characterized by FTIR, proximate and elemental analysis, and quantification of humic acids. The oxidation process led to an increased content of oxygenated groups and humic acids in the carbonaceous structure. The solid oxidized with air at 200 ºC for 12 h and re-oxidized with HNO3 for 12 h showed the highest percentage of humic acids (85.3%.

  10. Interaction of metals with humic acid isolated from oxidized coal

    Energy Technology Data Exchange (ETDEWEB)

    Erdogan, S.; Baysal, A.; Akba, O.; Hamamci, C. [Dicle University, Diyarbakir (Turkey)

    2007-07-01

    The sorption behaviour of divalent cations M{sup 2+} (Cu, Pb and Zn) and trivalent cations M{sup 2+} (Fe, Al) with humic acid isolated from oxidized coal (Hazro, SE Anatolia,Turkey) was followed in aqueous solution. Coal humic acid and metal ion interaction was investigated with special emphasis on the effects of pH, metal ion concentration and humic acid concentration. It has been found that the interaction of humic acid with metal ions in solution increases with pH, decreases with metal ion concentration and increases with humic acid concentration. The differences in sorption ability of particular metal ions on oxidized coal-derived humic acid are Fe> Pb> Cu> Al> Zn and Fe> Pb> Al> Cu> Zn at pH 2.5 and 3.5, respectively, while they are Fe=Pb=Cu=Al> Zn at both pH 4.5 and 5.5. The interaction of some trivalent (Fe, Al) and divalent (Cu, Pb, Zn) metal ions with humic acid prepared from coal was also studied using FTIR spectroscopy. This has proven helpful with respect to metal binding to understand better the potential sites of binding within the humic acid. Infrared spectroscopy showed the participation of COOH and OH groups in binding to the metal ions.

  11. Induction of (omega-1)-oxidation of monocarboxylic acids by acetylsalicylic acid.

    Science.gov (United States)

    Kundu, R K; Getz, G S; Tonsgard, J H

    1993-07-01

    Monocarboxylic acids may be oxidized at the omega- and (omega-1)- positions to form dicarboxylic acids (DCAs) and (omega-1)-hydroxy- or (omega-1)-oxoacids. The significance of this pathway under normal conditions is unknown, but DCAs and (omega-1)-hydroxyacids are prominent features of disease states. The stimulation of this pathway has been linked to induction of fatty acid-binding protein and peroxisomal proliferation. In this study, we examined the effect of acetylsalicylic acid (ASA) on (omega-1)-oxidation. (Omega-1)-oxidation was assessed in subcellular fractions of rat liver. Rats were fed a normal diet or an ASA-supplemented diet. Products were identified by gas chromatography-mass spectrometry (GC-MS) and by comparison with the properties of authentic synthetic standards. Doses of ASA that produced relatively low serum concentrations (12-24 mg/dl) resulted in as much as a 20-fold increase in the capacity for (omega-1)-oxidation of medium (C12-C15) and long chain (C16-C20) monocarboxylic acids. Normal rat liver oxidizes monocarboxylic acids to (omega-1)-oxoacids, while liver from ASA-treated rats converts these substrates to (omega-1)-oxodicarboxylic acids and (omega-1)-oxoacids. The formation of oxoacids and oxodicarboxylic acids may be due to different enzymes. The formation of oxodicarboxylic acids appears to be more labile than the formation of oxoacids. These two processes also are differentially induced by ASA and have different substrate specificities. These results demonstrate that ASA is a potent stimulant of (omega-1)-oxidation and induces the formation of products that can be shortened in peroxisomes to key metabolic intermediates.

  12. Iron (II) ions induced oxidation of ascorbic acid and glucose.

    Science.gov (United States)

    Mlakar, A; Batna, A; Dudda, A; Spiteller, G

    1996-12-01

    Lipid peroxidation (LPO) of polyunsaturated fatty acids (PUFAs) is suspected to be involved in the generation of chronic diseases. A model reaction for LPO is the air oxidation of PUFAs initiated by Fe2+ and ascorbic acid. In the course of such model reactions glycolaldehyde (GLA) was detected as main aldehydic product. Since it is difficult to explain the generat on of GLA by oxidation of PUFAs, it was suspected that GLA might be derived by oxidation of ascorbic acid. This assumption was verified by treatment of ascorbic acid with Fe2+. Produced aldehydic compounds were trapped by addition of pentafluorobenzylhydroxylamine hydrochloride (PFBHA-HCl), trimethylsilylated and finally identified by gas chromatography/mass spectronetry (GC/MS). Oxidation of ascorbic acid with O2 in presence of iron ions produced not only glycolaldehyde (GLA), but also glyceraldehyde (GA), dihydroxyacetone (DA) and formaldehyde. Glyoxal (GO) and malondialdehyde (MDA) were detected as trace compounds. The yield of the aldehydic compounds was increased by addition of lipid hydroperoxides (LOOH) or H2O2. The buffer influenced the reaction considerably: Iron ions react with Tris buffer by producing dihydroxyacetone (DA). Since ascorbic acid is present in biological systems and Fe2+ ions are obviously generated by cell damaging processes, the production of GLA and other aldehydic components might add to the damaging effects of LPO. Glucose suffers also oxidation to short-chain aldehydic compounds in aqueous solution, but this reaction requires addition of equimolar amounts of Fe2+ together with equimolar amounts of H2O2 or 13-hydroperoxy -9-cis-11-trans-octadecadienoic acid (13-HPODE). Therefore this reaction, also influenced by the buffer system, seems to be not of biological relevance.

  13. RS4-type resistant starch prevents high-fat diet-induced obesity via increased hepatic fatty acid oxidation and decreased postprandial GIP in C57BL/6J mice.

    Science.gov (United States)

    Shimotoyodome, Akira; Suzuki, Junko; Fukuoka, Daisuke; Tokimitsu, Ichiro; Hase, Tadashi

    2010-03-01

    Chemically modified starches (CMS) are RS4-type resistant starch, which shows a reduced availability, as well as high-amylose corn starch (HACS, RS2 type), compared with the corresponding unmodified starch. Previous studies have shown that RS4 increases fecal excretion of bile acids and reduces zinc and iron absorption in rats. The aim of this study was to investigate the effects of dietary RS4 supplementation on the development of diet-induced obesity in mice. Weight- and age-matched male C57BL/6J mice were fed for 24 wk on a high-fat diet containing unmodified starch, hydroxypropylated distarch phosphate (RS4), or HACS (RS2). Those fed the RS4 diet had significantly lower body weight and visceral fat weight than those fed either unmodified starch or the RS2 diet. Those fed the RS4 diet for 4 wk had a significantly higher hepatic fatty acid oxidation capacity and related gene expression and lower blood insulin than those fed either unmodified starch or the RS2 diet. Indirect calorimetry showed that the RS4 group exhibited higher energy expenditure and fat utilization compared with the RS2 group. When gavaged with fat (trioleate), RS4 stimulated a lower postprandial glucose-dependent insulinotropic polypeptide (GIP; incretin) response than RS2. Higher blood GIP levels induced by chronic GIP administration reduced fat utilization in high-fat diet-fed mice. In conclusion, dietary supplementation with RS4-type resistant starch attenuates high-fat diet-induced obesity more effectively than RS2 in C57BL/6J mice, which may be attributable to lower postprandial GIP and increased fat catabolism in the liver.

  14. Triflic acid catalyzed oxidative lactonization and diacetoxylation of alkenes using peroxyacids as oxidants.

    Science.gov (United States)

    Kang, Yan-Biao; Gade, Lutz H

    2012-02-03

    A clean and efficient diacetoxylation reaction of alkenes catalyzed by triflic acid using commercially available peroxyacids as the oxidants has been developed. This method was also applied in oxidative lactonizations of unsaturated carboxylic acids in good to high yields.

  15. Pre-cold stress increases acid stress resistance and induces amino ...

    African Journals Online (AJOL)

    Pre-cold stress increases acid stress resistance and induces amino acid homeostasis in Lactococcus lactis NZ9000. ... Compared to exposure to acid stress only, pre-adaptation to cold stress decreased the redox balance ratio and the formation of hydroxyl radicals, indicating a change in aerobic respiration and oxidative ...

  16. Oxidation of positronium atoms on a surface of oxidic catalyst carrier containing acid centres

    CERN Document Server

    Paiziev, A A

    2000-01-01

    By Born approximation the cross section of positronium (Ps) oxidation on acid centres localized on the surface of oxide carriers is calculated. Analysis of the kinetics of elementary processes in porous carriers based on aluminum oxide including processes of annihilation of positron, formation of Ps and oxidation of Ps on acid centres is given.

  17. THE INFLUENCE OF NIOBIUM ON THE ACIDITY AND STRUCTURE OF GAMMA-ALUMINA-SUPPORTED VANADIUM OXIDES

    Directory of Open Access Journals (Sweden)

    Sathler M.N.B.

    1998-01-01

    Full Text Available Gamma-alumina-supported niobium oxide was used as a support for vanadium oxides. The influence of the addition of niobium oxide was studied by looking for changes in the structure and acid-base character of superficial species. Vanadium oxide was deposited using the continuous adsorption method; niobium oxide was impregnated using the incipient wetness method. The catalysts were characterized by XPS, UV-visible and IR spectroscopy. Catalytic tests were performed using propane oxidation reaction at 400oC. For coverage below the monolayer, both vanadium and niobium oxides were observed in slightly condensed superficial species. The presence of vanadium oxide on the support was found to increase the Lewis acidity and create some Bronsted acidity. Higher catalytic activity and selectivity for propene were associated with vanadium oxides. The presence of niobium did not contribute to the modification of the chemical properties of superficial vanadium but did decrease the adsorption of vanadium on the alumina.

  18. Saw palmetto extract enhances erectile responses by inhibition of phosphodiesterase 5 activity and increase in inducible nitric oxide synthase messenger ribonucleic acid expression in rat and rabbit corpus cavernosum.

    Science.gov (United States)

    Yang, Surong; Chen, Changrui; Li, Yiying; Ren, Zhenghua; Zhang, Yungang; Wu, Gantong; Wang, Hao; Hu, Zhenzhen; Yao, Minghui

    2013-06-01

    To evaluate whether saw palmetto extract (SPE) relaxes corpus cavernosum and explore the underlying mechanisms. Forty Sprague-Dawley rats and 30 New Zealand rabbits were randomly allocated into 3 SPE-treated groups (low-, middle-, and high-dose) and 1 saline-treated control group. SPE was administered intragastrically for 7 consecutive days. Another 23 rats treated with sildenafil were used to appraise the erectile response to electrical stimulation of nerves in the corpus cavernosum. The erectile functions of rats and rabbits were evaluated 24 hours after the last SPE administration or 15 minutes after intragastric sildenafil. Outcome measures included corpus cavernosum electrical activity recording, phosphodiesterase 5 (PDE5) activity detected by the colorimetric quantitative method, and messenger ribonucleic acid (mRNA) expression level for PDE5 and inducible nitric oxide synthase (iNOS) determined using real-time polymerase chain reaction. In the SPE-treated animals, the relaxant response to electrical stimulation of nerves in the corpus cavernosum, reflected by the amplitude of the electrical activity within the cavernosum, was significantly and dose-dependently augmented. Similar effects were observed in the sildenafil-treated rats. PDE5 activity in rat and rabbit corpus cavernosum tissues was significantly and dose-dependently inhibited in SPE-treated animals, whereas the iNOS mRNA level increased compared with the saline group. PDE5 mRNA, however, was only significantly enhanced in the rats treated with the middle dose of SPE. The results suggest that SPE may have potential application value for the prevention or treatment of erectile dysfunction through an increase in iNOS mRNA expression and inhibition of PDE5 activity in corpus cavernosum smooth muscles. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. Quinolinic Acid: Neurotoxin or Oxidative Stress Modulator?

    Directory of Open Access Journals (Sweden)

    Lenka Kubicova

    2013-10-01

    Full Text Available Quinolinic acid (2,3-pyridinedicarboxylic acid, QUIN is a well-known neurotoxin. Consequently, QUIN could produce reactive oxygen species (ROS. ROS are generated in reactions catalyzed by transition metals, especially iron (Fe. QUIN can form coordination complexes with iron. A combination of differential pulse voltammetry, deoxyribose degradation and Fe(II autoxidation assays was used for explorating ROS formation in redox reactions that are catalyzed by iron in QUIN-Fe complexes. Differential pulse voltammetry showed an anodic shift of the iron redox potential if iron was liganded by QUIN. In the H2O2/FeCl3/ascorbic acid variant of the deoxyribose degradation assay, the dose-response curve was U-shaped. In the FeCl3/ascorbic acid variant, QUIN unambiguously showed antioxidant effects. In the Fe(II autoxidation assay, QUIN decreased the rate of ROS production caused by Fe(II oxidation. Our study confirms that QUIN toxicity may be caused by ROS generation via the Fenton reaction. This, however, applies only for unnaturally high concentrations that were used in attempts to provide support for the neurotoxic effect. In lower concentrations, we show that by liganding iron, QUIN affects the Fe(II/Fe(III ratios that are beneficial to homeostasis. Our results support the notion that redox chemistry can contribute to explaining the hormetic dose-response effects.

  20. Amino acids as modulators of endothelium-derived nitric oxide.

    Science.gov (United States)

    Kakoki, Masao; Kim, Hyung-Suk; Edgell, Cora-Jean S; Maeda, Nobuyo; Smithies, Oliver; Mattson, David L

    2006-08-01

    To examine the mechanisms whereby amino acids modulate nitric oxide (NO) production and blood flow in the renal vasculature, chemiluminescence techniques were used to quantify NO in the renal venous effluent of the isolated, perfused rat kidney as different amino acids were added to the perfusate. The addition of 10(-4) or 10(-3) M cationic amino acids (l-ornithine, l-lysine, or l-homoarginine) or neutral amino acids (l-glutamine, l-leucine, or l-serine) to the perfusate decreased NO and increased renal vascular resistance. Perfusion with anionic amino acids (l-glutamate or l-aspartate) had no effect on either parameter. The effects of the cationic and neutral amino acids were reversed with 10(-3) M l-arginine and prevented by deendothelialization or NO synthase inhibition. The effects of the neutral amino acids but not the cationic amino acids were dependent on extracellular sodium. Cationic and neutral amino acids also decreased calcimycin-induced NO, as assessed by DAF-FM-T fluorescence, in cultured EA.hy926 endothelial cells. Inhibition of system y(+) or y(+)L by siRNA for the cationic amino acid transporter 1 or the CD98/4F2 heavy chain diminished the NO-depleting effects of these amino acids. Finally, transport studies in cultured cells demonstrated that cationic or neutral amino acids in the extracellular space stimulate efflux of l-arginine out of the cell. Thus the present experiments demonstrate that cationic and neutral amino acids can modulate NO production in endothelial cells by altering cellular l-arginine transport through y(+) and y(+)L transport mechanisms.

  1. Effect of sulfonylureas on hepatic fatty acid oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Patel, T.B.

    1986-08-01

    In isolated rat livers perfused with oleic acid (0.1 mM), infusion of tolbutamide or glyburide decreased the rate of ketogenesis in a dose-dependent manner. The inhibition of fatty acid oxidation was maximal at 2.0 mM and 10 M concentrations of tolbutamide and glyburide, respectively. Neither tolbutamide nor glyburide inhibited ketogenesis in livers perfused with octanoate. The inhibition of hepatic ketogenesis by sulfonylureas was independent of perfusate oleic acid concentration. Additionally, in rat livers perfused with oleic acid in the presence of L-(-)-carnitine (10 mM), submaximal concentrations of tolbutamide and glyburide did not inhibit hepatic ketogenesis. Finally, glyburide infusion into livers perfused with (U- $C)oleic acid (0.1 mM) increased the rate of UC label incorporation into hepatic triglycerides by 2.5-fold. These data suggest that both tolbutamide and glyburide inhibit long-chain fatty acid oxidation by inhibition the key regulatory enzyme, carnitine palmitoyltransferase I, most probably by competing with L-(-)-carnitine.

  2. Electrocatalysis by nanoparticles: Oxidation of formic acid at manganese oxide nanorods-modified Pt planar and nanohole-arrays

    Directory of Open Access Journals (Sweden)

    Mohamed S. El-Deab

    2010-01-01

    Full Text Available The electro-oxidation of formic acid (an essential reaction in direct formic acid fuel cells is a challenging process because of the deactivation of anodes by the adsorption of the poisoning intermediate carbon monoxide (CO. Pt electrodes in two geometries (planar and nanohole-array were modified by the electrodeposition of manganese oxide nanorods (nano-MnOx. The modified Pt electrodes were then tested for their electrocatalytic activity through the electro-oxidation of formic acid in a solution of pH 3.45. Two oxidation peaks (Ipd and Ipind were observed at 0.2 and 0.55 V, respectively; these were assigned to the direct and indirect oxidative pathways. A significant enhancement of the direct oxidation of formic acid to CO2 was observed at the modified electrodes, while the formation of the poisoning intermediate CO was suppressed. Ipd increases with surface coverage (θ of nano-MnOx with a concurrent depression of Ipind. An increase in the ratio Ipd/ν1/2 with decreasing potential scan rate (ν indicates that the oxidation process proceeds via a catalytic mechanism. The modification of Pt anodes with manganese oxide nanorods results in a significant improvement of the electrocatalytic activity along with a higher tolerance to CO. Thus nano-MnOx plays a crucial role as a catalytic mediator which facilitates the charge transfer during the direct oxidation of formic acid to CO2.

  3. Oxide for valve-regulated lead-acid batteries

    Science.gov (United States)

    Lam, L. T.; Lim, O. V.; Haigh, N. P.; Rand, D. A. J.; Manders, J. E.; Rice, D. M.

    In order to meet the increasing demand for valve-regulated lead-acid (VRLA) batteries, a new soft lead has been produced by Pasminco Metals. In this material, bismuth is increased to a level that produces a significant improvement in battery cycle life. By contrast, other common impurities, such as arsenic, cobalt, chromium, nickel, antimony and tellurium, that are known to be harmful to VRLA batteries are controlled to very low levels. A bismuth (Bi)-bearing oxide has been manufactured (Barton-pot method) from this soft lead and is characterized in terms of phase composition, particle size distribution, BET surface area, and reactivity. An investigation is also made of the rates of oxygen and hydrogen evolution on pasted electrodes prepared from the Bi-bearing oxide. For comparison, the characteristics and performance of a Bi-free (Barton-pot) oxide, which is manufactured in the USA, are also examined. Increasing the level of bismuth and lowering those of the other impurities in soft lead produces no unusual changes in either the physical or the chemical properties of the resulting Bi-bearing oxide compared with Bi-free oxide. This is very important because there is no need for battery manufacturers to change their paste formulae and paste-mixing procedures on switching to the new Bi-bearing oxide. There is little difference in the rates of oxygen and hydrogen evolution on pasted electrodes prepared from Bi-bearing or Bi-free oxides. On the other hand, these rates increase on the former electrodes when the levels of all the other impurities are made to exceed (by deliberately adding the impurities as oxide powders) the corresponding, specified values for the Bi-bearing oxide. The latter behaviour is particularly noticeable for hydrogen evolution, which is enhanced even further when a negative electrode prepared from Bi-bearing oxide is contaminated through the deposition of impurities added to the sulfuric acid solution. The effects of impurities in the positive

  4. Oxide for valve-regulated lead-acid batteries

    Energy Technology Data Exchange (ETDEWEB)

    Lam, L.T.; Lim, O.V.; Haigh, N.P.; Rand, D.A.J. [CSIRO, Div. of Minerals, Clayton South, Vic. (Australia); Manders, J.E.; Rice, D.M. [Pasminco Metals, Melbourne, Vic. (Australia)

    1998-05-18

    In order to meet the increasing demand for valve-regulated lead-acid (VRLA) batteries, a new soft lead has been produced by Pasminco Metals. In this material, bismuth is increased to a level that produces a significant improvement in battery cycle life. By contrast, other common impurities, such as arsenic, cobalt, chromium, nickel, antimony and tellurium, that are known to be harmful to VRLA batteries are controlled to very low levels. A bismuth (Bi)-bearing oxide has been manufactured (Barton-pot method) from this soft lead and is characterized in terms of phase composition, particle size distribution, BET surface area, and reactivity. An investigation is also made of the rates of oxygen and hydrogen evolution on pasted electrodes prepared from the Bi-bearing oxide. For comparison, the characteristics and performance of a Bi-free (Barton-pot) oxide, which is manufactured in the USA, are also examined. Increasing the level of bismuth and lowering those of the other impurities in soft lead produces no unusual changes in either the physical or the chemical properties of the resulting Bi-bearing oxide compared with Bi-free oxide. This is very important because there is no need for battery manufacturers to change their paste formulae and paste-mixing procedures on switching to the new Bi-bearing oxide. There is little difference in the rates of oxygen and hydrogen evolution on pasted electrodes prepared from Bi-bearing or Bi-free oxides. On the other hand, these rates increase on the former electrodes when the levels of all the other impurities are made to exceed (by deliberately adding the impurities as oxide powders) the corresponding, specified values for the Bi-bearing oxide. The latter behaviour is particularly noticeable for hydrogen evolution, which is enhanced even further when a negative electrode prepared from Bi-bearing oxide is contaminated through the deposition of impurities added to the sulfuric acid solution. The effects of impurities in the positive

  5. Increased systemic oxidatively generated DNA and RNA damage in schizophrenia

    DEFF Research Database (Denmark)

    Jørgensen, Anders; Brødbæk, Kasper; Fink-Jensen, Anders

    2013-01-01

    such as cardiovascular disease, type 2 diabetes and dementia. We determined the urinary excretion of markers of systemic Deoxyribonucleic Acid (DNA) and Ribonucleic Acid (RNA) oxidation, 8-oxo-7,8-dihydro-2'-deoxyguanosine and 8-oxo-7,8-dihydroguanosine, respectively, in 40 schizophrenia patients and 40 age- and sex...

  6. Oxidation of hydrogen peroxide by [Ni (cyclam)] in aqueous acidic ...

    Indian Academy of Sciences (India)

    III. (cyclam)]. 3+ in aqueous acidic media. SANKARAN ANURADHA and VENKATAPURAM RAMANUJAM VIJAYARAGHAVAN. ∗. Department of Physical ... oxidation was followed spectrophotometrically by examining the oxidation of nickel(II) complexes of macro- .... stock solution of copper perchlorate was prepared by.

  7. Oxidation of hypotaurine and cysteine sulphinic acid by peroxynitrite.

    Science.gov (United States)

    Fontana, Mario; Amendola, Donatella; Orsini, Emanuela; Boffi, Alberto; Pecci, Laura

    2005-07-01

    Peroxynitrite mediates the oxidation of the sulphinic group of both HTAU (hypotaurine) and CSA (cysteine sulphinic acid), producing the respective sulphonates, TAU (taurine) and CA (cysteic acid). The reaction is associated with extensive oxygen uptake, suggesting that HTAU and CSA are oxidized by the one-electron transfer mechanism to sulphonyl radicals, which may initiate an oxygen-dependent radical chain reaction with the sulphonates as final products. Besides the one-electron mechanism, HTAU and CSA can be oxidized by the two-electron pathway, leading directly to sulphonate formation without oxygen consumption. The apparent second-order rate constants for the direct reaction of peroxynitrite with HTAU and CSA at pH 7.4 and 25 degrees C are 77.4+/-5 and 76.4+/-9 M(-1).s(-1) respectively. For both sulphinates, the apparent second-order rate constants increase sharply with decrease in pH, and the sigmoidal curves obtained are consistent with peroxynitrous acid as the species responsible for sulphinate oxidation. The kinetic data, together with changes in oxygen uptake, sulphinate depletion, sulphonate production, and product distribution of nitrite and nitrate, suggest that oxidation of sulphinates by peroxynitrite may take place by the two reaction pathways whose relative importance depends on reagent concentrations and pH value. In the presence of bicarbonate, the direct reaction of sulphinates with peroxynitrite is inhibited and the oxidative reaction probably involves only the radicals *NO2 and CO3*-, generated by decomposition of the peroxynitrite-CO2 adduct.

  8. Mitochondrial fatty acid oxidation alterations in heart failure, ischaemic heart disease and diabetic cardiomyopathy

    Science.gov (United States)

    Fillmore, N; Mori, J; Lopaschuk, G D

    2014-01-01

    Heart disease is a leading cause of death worldwide. In many forms of heart disease, including heart failure, ischaemic heart disease and diabetic cardiomyopathies, changes in cardiac mitochondrial energy metabolism contribute to contractile dysfunction and to a decrease in cardiac efficiency. Specific metabolic changes include a relative increase in cardiac fatty acid oxidation rates and an uncoupling of glycolysis from glucose oxidation. In heart failure, overall mitochondrial oxidative metabolism can be impaired while, in ischaemic heart disease, energy production is impaired due to a limitation of oxygen supply. In both of these conditions, residual mitochondrial fatty acid oxidation dominates over mitochondrial glucose oxidation. In diabetes, the ratio of cardiac fatty acid oxidation to glucose oxidation also increases, although primarily due to an increase in fatty acid oxidation and an inhibition of glucose oxidation. Recent evidence suggests that therapeutically regulating cardiac energy metabolism by reducing fatty acid oxidation and/or increasing glucose oxidation can improve cardiac function of the ischaemic heart, the failing heart and in diabetic cardiomyopathies. In this article, we review the cardiac mitochondrial energy metabolic changes that occur in these forms of heart disease, what role alterations in mitochondrial fatty acid oxidation have in contributing to cardiac dysfunction and the potential for targeting fatty acid oxidation to treat these forms of heart disease. LINKED ARTICLES This article is part of a themed issue on Mitochondrial Pharmacology: Energy, Injury & Beyond. To view the other articles in this issue visit http://dx.doi.org/10.1111/bph.2014.171.issue-8 PMID:24147975

  9. Prevalent mutations in fatty acid oxidation disorders

    DEFF Research Database (Denmark)

    Gregersen, N; Andresen, B S; Bross, P

    2000-01-01

    UNLABELLED: The mutational spectrum in a given disease-associated gene is often comprised of a large number of different mutations, of which a single or a few are present in a large proportion of diseased individuals. Such prevalent mutations are known in four genes of the fatty acid oxidation...... carrying the prevalent 985A > G mutation are at risk of developing life-threatening attacks. In SCAD/ethylmalonic aciduria, on the other hand, the presence of the prevalent susceptibility variations, 625A and 511T, in the SCAD gene seems to require additional genetic and cellular factors to be present...... in order to result in a phenotype. For the prevalent mutations in the LCHAD and CPT II genes further data are needed to evaluate the penetrance and risk of manifest disease when carrying these mutations. CONCLUSION: Assessment of the prevalence of a prevalent mutation in the mutation spectrum...

  10. Clarithromycin, trimethoprim, and penicillin and oxidative nucleic acid modifications in humans: randomised, controlled trials

    DEFF Research Database (Denmark)

    Larsen, Emil List; Cejvanovic, Vanja; Kjær, Laura Kofoed

    2017-01-01

    , phenoxymethylpenicillin (penicillin V), or placebo. Oxidative modifications were measured as 24-h urinary excretion of 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydroguanosine (8-oxoGuo), and plasma levels of malondialdehyde before and after treatment as a measurement of DNA oxidation, RNA oxidation.......7% (95% CI: 5.8–37.6%), but did not influence urinary excretion of 8-oxoGuo. Penicillin V did not influence urinary excretion of 8-oxodG or 8-oxoGuo. None of the antibiotic drugs influenced plasma levels of malondialdehyde. Conclusion Clarithromycin significantly increases oxidative nucleic acid...... modifications. Increased oxidative modifications might explain some of clarithromycin's known adverse reactions. Trimethoprim significantly lowers DNA oxidation but not RNA oxidation. Penicillin V had no effect on oxidative nucleic acid modifications....

  11. Fatty acids and oxidative stress in psychiatric disorders

    Directory of Open Access Journals (Sweden)

    Tonello Lucio

    2008-04-01

    Full Text Available Abstract Background The aim of this study was to determine whether there is published evidence for increased oxidative stress in neuropsychiatric disorders. Methods A PubMed search was carried out using the MeSH search term 'oxidative stress' in conjunction with each of the DSM-IV-TR diagnostic categories of the American Psychiatric Association in order to identify potential studies. Results There was published evidence of increased oxidative stress in the following DSM-IV-TR diagnostic categories: mental retardation; autistic disorder; Rett's disorder; attention-deficit hyperactivity disorder; delirium; dementia; amnestic disorders; alcohol-related disorders; amphetamine (or amphetamine-like-related disorders; hallucinogen-related disorders; nicotine-related disorders; opioid-related disorders; schizophrenia and other psychotic disorders; mood disorders; anxiety disorders; sexual dysfunctions; eating disorders; and sleep disorders. Conclusion Most psychiatric disorders are associated with increased oxidative stress. Patients suffering from that subgroup of these psychiatric disorders in which there is increased lipid peroxidation might therefore benefit from fatty acid supplementation (preferably with the inclusion of an antioxidant-rich diet while patients suffering from all these psychiatric disorders might benefit from a change to a whole-food plant-based diet devoid of refined carbohydrate products.

  12. Studies on the biological oxidation - The oxidation of ascorbic acid (vitamin C) in biological fluids

    OpenAIRE

    Guzmán Barrón, E. S.; Departamento de Medicina, Universidad de Chicago, Chicago, Estados Unidos; Facultad de Ciencias Médicas, Universidad de Lima, Lima, Perú; Guzmán Barrón, Alberto; Departamento de Medicina, Universidad de Chicago, Chicago, Estados Unidos; Facultad de Ciencias Médicas, Universidad de Lima, Lima, Perú; Klemperer, Friedrich; Departamento de Medicina, Universidad de Chicago, Chicago, Estados Unidos; Facultad de Ciencias Médicas, Universidad de Lima, Lima, Perú

    2014-01-01

    Biological fluids can be divided according to their behavior toward ascorbic acid into two groups: those having an inhibitory mechanism that protects the ascorbic acid oxidation, and those lacking this mechanism. Animal fluids and some of vegetable origin (those containing dosables amounts of ascorbic acid) corresponding to the first group. Ascorbic acid is protected from oxidation in the fluids by the action of copper catalyst. Fluids from plants (those that contain very little ascorbic acid...

  13. Regulation and limitations to fatty acid oxidation during exercise

    DEFF Research Database (Denmark)

    Jeppesen, Jacob; Kiens, Bente

    2012-01-01

    Fatty acids (FA) as fuel for energy utilization during exercise originate from different sources: FA transported in the circulation either bound to albumin or as triacylglycerol (TG) carried by very low density lipoproteins (VLDL) and FA from lipolysis of muscle TG stores (IMTG). Despite a high...... rate of energy expenditure during high intensity exercise the total fatty acid oxidation is suppressed to below that observed during moderate intensity exercise. Although this has been known for many years, the mechanisms behind this phenomenon are still not fully elucidated. A failure of adipose...... tissue to deliver sufficient fatty acids to exercising muscle has been proposed, but evidence is emerging that factors within the muscle might be of more importance. The high rate of glycolysis during high intensity exercise might be the "driving force" via the increased production of acetyl CoA which...

  14. Omega-3 fatty acids differentially modulate enzymatic anti-oxidant systems in skeletal muscle cells

    OpenAIRE

    da Silva, E. P.; Nachbar, R. T.; Levada-Pires, A. C.; Hirabara, S. M.; Lambertucci, R. H.

    2015-01-01

    During physical activity, increased reactive oxygen species production occurs, which can lead to cell damage and in a decline of individual’s performance and health. The use of omega-3 polyunsaturated fatty acids as a supplement to protect the immune system has been increasing; however, their possible benefit to the anti-oxidant system is not well described. Thus, the aim of this study was to evaluate whether the omega-3 fatty acids (docosahexaenoic acid and eicosapentaenoic acid) can be bene...

  15. Study of Perfluorophosphonic Acid Surface Modifications on Zinc Oxide Nanoparticles

    Directory of Open Access Journals (Sweden)

    Rosalynn Quiñones

    2017-11-01

    Full Text Available In this study, perfluorinated phosphonic acid modifications were utilized to modify zinc oxide (ZnO nanoparticles because they create a more stable surface due to the electronegativity of the perfluoro head group. Specifically, 12-pentafluorophenoxydodecylphosphonic acid, 2,3,4,5,6-pentafluorobenzylphosphonic acid, and (1H,1H,2H,2H-perfluorododecylphosphonic acid have been used to form thin films on the nanoparticle surfaces. The modified nanoparticles were then characterized using infrared spectroscopy, X-ray photoelectron spectroscopy, and solid-state nuclear magnetic resonance spectroscopy. Dynamic light scattering and scanning electron microscopy-energy dispersive X-ray spectroscopy were utilized to determine the particle size of the nanoparticles before and after modification, and to analyze the film coverage on the ZnO surfaces, respectively. Zeta potential measurements were obtained to determine the stability of the ZnO nanoparticles. It was shown that the surface charge increased as the alkyl chain length increases. This study shows that modifying the ZnO nanoparticles with perfluorinated groups increases the stability of the phosphonic acids adsorbed on the surfaces. Thermogravimetric analysis was used to distinguish between chemically and physically bound films on the modified nanoparticles. The higher weight loss for 12-pentafluorophenoxydodecylphosphonic acid and (1H,1H,2H,2H-perfluorododecylphosphonic acid modifications corresponds to a higher surface concentration of the modifications, and, ideally, higher surface coverage. While previous studies have shown how phosphonic acids interact with the surfaces of ZnO, the aim of this study was to understand how the perfluorinated groups can tune the surface properties of the nanoparticles.

  16. Defective methionine metabolism in the brain after repeated blast exposures might contribute to increased oxidative stress.

    Science.gov (United States)

    Arun, Peethambaran; Rittase, William B; Wilder, Donna M; Wang, Ying; Gist, Irene D; Long, Joseph B

    2017-07-31

    Blast-induced traumatic brain injury (bTBI) is one of the major disabilities in Service Members returning from recent military operations. The neurobiological underpinnings of bTBI, which are associated with acute and chronic neuropathological and neurobehavioral deficits, are uncertain. Increased oxidative stress in the brain is reported to play a significant role promoting neuronal damage associated with both brain injury and neurodegenerative disorders. In this study, brains of rats exposed to repeated blasts in a shock tube underwent untargeted profiling of primary metabolism by automatic linear exchange/cold injection GC-TOF mass spectrometry and revealed acute and sub-acute disruptions in the metabolism of the essential amino acid methionine and associated antioxidants. Methionine sulfoxide, the oxidized metabolite of methionine, showed a sustained increase in the brain after blast exposure which was associated with a significant decrease in cysteine, the amino acid derived from methionine. Glutathione, the antioxidant synthesized from cysteine, also concomitantly decreased as did the antioxidant ascorbic acid. Reductions in ascorbic acid were accompanied by increased levels of its oxidized metabolite, dehydroascorbic acid and other metabolites such as threonic acid, isothreonic acid, glycolic acid and oxalic acid. Fluorometric analysis of the brains showed acute and sub-acute increase in total reactive oxygen species. In view of the fundamental importance of glutathione in the brain as an antioxidant, including its role in the reduction of dehydroascorbic acid to ascorbic acid, the disruptions in methionine metabolism elicited by blast exposure might prominently contribute to neuronal injury by promoting increased and sustained oxidative stress. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Mechanistic chemistry of oxidation of balsalazide with acidic ...

    Indian Academy of Sciences (India)

    2-hydroxy-5-nitroso-benzoic acid and 3-(4-nitroso-benzoylamino)-propionic acid are identified as the oxidation products of BSZ with both CAT and BAT. The rate of oxidation of BSZ is about five-fold faster with BAT than with CAT. Plausible mechanism and related rate law have been deduced for the observed kinetics.

  18. Kinetics and mechanism of the oxidation of some -hydroxy acids ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 116; Issue 6. Kinetics and mechanism of the oxidation of some -hydroxy acids by hexamethylenetetramine-bromine ... The oxidation of -deuteriomandelic acid exhibits the presence of a substantial kinetic isotope effect (/ = 5.91 at 298 K). The rates of ...

  19. Fatty Acid Incubation of Myotubues from Humans with Type 2 Diabetes Leads to Enhanced Release of Beta Oxidation Products Due to Impaired Fatty Acid Oxidation

    DEFF Research Database (Denmark)

    Wensaas, Andreas J; Rustan, Arild C; Just, Marlene

    2008-01-01

    Objective: Increased availability of fatty acids is important for accumulation of intracellular lipids and development of insulin resistance in human myotubes. It is unknown whether different types of fatty acids like eicosapentaenoic acid (EPA) or tetradecylthioacetic acid (TTA) influence...... these processes. Research Design and Methods: We examined fatty acid and glucose metabolism, and gene expression in cultured human skeletal muscle cells from control and T2D individuals after four days preincubation with EPA or TTA. Results: T2D myotubes exhibited reduced formation of CO(2) from palmitic acid (PA....... EPA markedly enhanced TAG accumulation in myotubes, more pronounced in T2D cells. TAG accumulation and fatty acid oxidation were inversely correlated only after EPA preincubation, and total level of acyl-CoA was reduced. Glucose oxidation (CO(2) formation) was enhanced and lactate production decreased...

  20. Platinum nanoparticles–manganese oxide nanorods as novel binary catalysts for formic acid oxidation

    OpenAIRE

    El-Deab, Mohamed S.

    2012-01-01

    The current study proposes a novel binary catalyst system (composed of metal/metal oxide nanoparticles) as a promising electrocatalyst in formic acid oxidation. The electro-catalytic oxidation of formic acid is carried out with binary catalysts of Pt nanoparticles (nano-Pt) and manganese oxide nanorods (nano-MnOx) electrodeposited onto glassy carbon (GC) electrodes. Cyclic voltammetric (CV) measurements showed that unmodified GC and nano-MnOx/GC electrodes have no catalytic activity. While tw...

  1. Mitochondrial free fatty acid β-oxidation supports oxidative phosphorylation and proliferation in cancer cells.

    Science.gov (United States)

    Rodríguez-Enríquez, Sara; Hernández-Esquivel, Luz; Marín-Hernández, Alvaro; El Hafidi, Mohammed; Gallardo-Pérez, Juan Carlos; Hernández-Reséndiz, Ileana; Rodríguez-Zavala, José S; Pacheco-Velázquez, Silvia C; Moreno-Sánchez, Rafael

    2015-08-01

    Oxidative phosphorylation (OxPhos) is functional and sustains tumor proliferation in several cancer cell types. To establish whether mitochondrial β-oxidation of free fatty acids (FFAs) contributes to cancer OxPhos functioning, its protein contents and enzyme activities, as well as respiratory rates and electrical membrane potential (ΔΨm) driven by FFA oxidation were assessed in rat AS-30D hepatoma and liver (RLM) mitochondria. Higher protein contents (1.4-3 times) of β-oxidation (CPT1, SCAD) as well as proteins and enzyme activities (1.7-13-times) of Krebs cycle (KC: ICD, 2OGDH, PDH, ME, GA), and respiratory chain (RC: COX) were determined in hepatoma mitochondria vs. RLM. Although increased cholesterol content (9-times vs. RLM) was determined in the hepatoma mitochondrial membranes, FFAs and other NAD-linked substrates were oxidized faster (1.6-6.6 times) by hepatoma mitochondria than RLM, maintaining similar ΔΨm values. The contents of β-oxidation, KC and RC enzymes were also assessed in cells. The mitochondrial enzyme levels in human cervix cancer HeLa and AS-30D cells were higher than those observed in rat hepatocytes whereas in human breast cancer biopsies, CPT1 and SCAD contents were lower than in human breast normal tissue. The presence of CPT1 and SCAD in AS-30D mitochondria and HeLa cells correlated with an active FFA utilization in HeLa cells. Furthermore, the β-oxidation inhibitor perhexiline blocked FFA utilization, OxPhos and proliferation in HeLa and other cancer cells. In conclusion, functional mitochondria supported by FFA β-oxidation are essential for the accelerated cancer cell proliferation and hence anti-β-oxidation therapeutics appears as an alternative promising approach to deter malignant tumor growth. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Oct-2-yn-4-enoyl-CoA as a multifunctional enzyme inhibitor in fatty acid oxidation.

    Science.gov (United States)

    Wu, Long; Liu, Xiaojun; Li, Ding

    2008-06-05

    Oct-2-yn-4-enoyl-CoA was found to be a multifunctional irreversible enzyme inhibitor in fatty acid oxidation mainly targeting mitochondrial trifunctional protein beta-subunit. It can also inactivate enoyl-CoA hydratase 2 and medium-chain acyl-CoA dehydrogenase. This study increased our understanding for the effect of acetylenic acids on fatty acid oxidation.

  3. Ascorbic Acid and Beta-Carotene Alleviate Oxidative Effect of ...

    African Journals Online (AJOL)

    Ascorbic Acid and Beta-Carotene Alleviate Oxidative Effect of London King Size® Cigarette Smoke on Tissue Lipids. ... Malondialdehyde production in the tissues was reduced by ascorbic acid and or beta-carotene given daily to the rats. It is implied that ascorbic acid or ... http://dx.doi.org/10.4314/njhbs.v2i1.11451.

  4. Consumption of oxidized oil increases oxidative stress in broilers and affects the quality of breast meat.

    Science.gov (United States)

    Zhang, Wangang; Xiao, Shan; Lee, Eun Joo; Ahn, Dong U

    2011-02-09

    A total of 120 4-week-old broiler chickens were allotted to 12 pens and fed one of three diets including control, oxidized diet (5% oxidized oil), or antioxidant-added diet (500 IU vitamin E) for 2 weeks. Blood samples were collected at the end of feeding trial, and breast muscles were sampled immediately after slaughter. Breast meats were also collected 24 h after slaughter and used for meat quality measurements. Oxidative stress in blood, lipid and protein oxidation, and sarcoplasmic reticulum Ca²(+)-ATPase (SERCA) activity of breast muscle were determined. The oxidized diet increased oxidative stress in blood and increased carbonyl content in breast meat compared with the other two dietary treatments (P Meat from birds fed the oxidized diet showed higher drip loss after 1 and 3 days of storage and greater 0-1 h post-mortem pH decline (P < 0.05). Significant differences in specific SERCA activity in breast muscles from birds fed control and oxidized diets (P < 0.05) were detected. This suggested that dietary oxidized oil induced oxidative stress in live birds and increased lipid and protein oxidation in breast muscle. Decrease in SERCA activity in breast muscles due to oxidative stress in live animals accelerated post-mortem glycolysis, which sped the pH drop after slaughter and increased drip loss, indicating that oxidation of diet can cause PSE-like (pale, soft, and exudative) conditions in broiler breast muscles.

  5. Transformation of Unsaturated Fatty Acids/Esters to Corresponding Keto Fatty Acids/Esters by Aerobic Oxidation with Pd(II)/Lewis Acid Catalyst.

    Science.gov (United States)

    Senan, Ahmed M; Zhang, Sicheng; Zeng, Miao; Chen, Zhuqi; Yin, Guochuan

    2017-08-16

    Utilization of renewable biomass to partly replace the fossil resources in industrial applications has attracted attention due to the limited fossil feedstock with the increased environmental concerns. This work introduced a modified Wacker-type oxidation for transformation of unsaturated fatty acids/esters to the corresponding keto fatty acids/esters, in which Cu2+ cation was replaced with common nonredox metal ions, that is, a novel Pd(II)/Lewis acid (LA) catalyst. It was found that adding nonredox metal ions can effectively promote Pd(II)-catalyzed oxidation of unsaturated fatty acids/esters to the corresponding keto fatty acids/esters, even much better than Cu2+, and the promotional effect is highly dependent on the Lewis acidity of added nonredox metal ions. The improved catalytic efficiency is attributed to the formation of heterobimetallic Pd(II)/LA species, and the oxidation mechanism of this Pd(II)/LA catalyst is also briefly discussed.

  6. Time resolved study of hydroxyl radical oxidation of oleic acid at the air-water interface

    Science.gov (United States)

    Zhang, Xinxing; Barraza, Kevin M.; Upton, Kathleen T.; Beauchamp, J. L.

    2017-09-01

    The ubiquity of oleic acid (OA) renders it a poster child for laboratory investigations of environmental oxidation chemistry. In the current study, mechanistic details of the oxidation of OA by hydroxyl radicals at the air-water interface are investigated using field-induced droplet ionization mass spectrometry (FIDI-MS). Products from OH oxidation of both unsaturated and saturated carbon atoms are identified, and mechanisms for both types of oxidation processes are proposed. Uptake of oxygen in the interfacial layer increases linearly with time, consistent with Langmuir-Hinshelwood reaction kinetics. These results provide fundamental knowledge relating to OH initiated degradation of fatty acids in atmospheric aerosols.

  7. The rationale for preventing cancer cachexia: targeting excessive fatty acid oxidation.

    Science.gov (United States)

    Qian, Chao-Nan

    2016-07-21

    Cachexia commonly occurs at the terminal stage of cancer and has largely unclear molecular mechanisms. A recent study published in Nature Medicine, entitled "Excessive fatty acid oxidation induces muscle atrophy in cancer cachexia," reveals that cachectic cancer cells can secrete multiple cytokines that induce excessive fatty acid oxidation, which is responsible for muscle loss in cancer cachexia. Inhibition of fatty acid oxidation using etomoxir can increase muscle mass and body weight in cancer cachexia animal models. The usage of stable cachexia animal models is also discussed in this research highlight.

  8. Bone reactions to oxidized titanium implants with electrochemical anion sulphuric acid and phosphoric acid incorporation.

    Science.gov (United States)

    Sul, Young-Taeg; Johansson, Carina B; Kang, Yunmo; Jeon, Dong-Gyun; Albrektsson, Tomas

    2002-01-01

    The importance of the surface properties of implants for a successful osseointegration has been emphasized. It is generally known that bone response to implant surfaces is considerably related to the various surface properties. The purpose of this study was to investigate bone tissue reactions to multifactorial biocompatibility of the surface oxide of electrochemically oxidized titanium implants. The ultimate objective was to improve surface quality, resulting in enhancement of clinical outcomes of osseointegrated implants. Three different surface types of commercially pure titanium (c.p. Ti) implants were prepared. Turned implants were used for controls and test implants were prepared by the micro arc oxidation (MAO) method, either in sulphuric acid (S implants) or in phosphoric acid (P implants). Implants were inserted in the femur and tibia of 10 mature New Zealand White rabbits. The bone response was evaluated by biomechanical tests, histology, and histomorphometry. The follow-up time was 6 weeks. The mean peak values of the removal torque showed significant differences between control and test S implants (p =.022) but showed no significant differences between control and test P implants (p =.195) or between test S and test P implants (p =.457). In addition, the histomorphometric comparisons of the bone-to-metal contact around entire implants demonstrated 186% increase in S implants (p =.028) and 232% increase in P implants (p =.028) compared with the paired control groups. Quantification of the bone area in the threads did not show any significant differences. The present results suggest that the primary mode of action in strong bone response to S implants is mechanical interlocking, and to P implants, it is biochemical interaction. It is possible that the phosphate groups in the titanium oxide of P implants provide potential chemical bonding sites for calcium ions and hydroxyapatite of the bone matrix during biologic mineralization. key words: bone responses

  9. Decreased total antioxidant levels and increased oxidative stress in ...

    African Journals Online (AJOL)

    Background: Chronic hyperglycaemia in diabetes mellitus leads to increased lipid peroxidation in the body, followed by the development of chronic complications due to oxidative stress. Objective: The aim of this study was to compare total antioxidant (TAO) levels and oxidative stress in type 2 diabetes mellitus (T2DM) ...

  10. Phosphonic Acids for Interfacial Engineering of Transparent Conductive Oxides

    KAUST Repository

    Paniagua, Sergio A.

    2016-05-26

    Transparent conducting oxides (TCOs), such as indium tin oxide and zinc oxide, play an important role as electrode materials in organic-semiconductor devices. The properties of the inorganic-organic interface - the offset between the TCO Fermi level and the relevant transport level, the extent to which the organic semiconductor can wet the oxide surface, and the influence of the surface on semiconductor morphology - significantly affect device performance. This review surveys the literature on TCO modification with phosphonic acids (PAs), which has increasingly been used to engineer these interfacial properties. The first part outlines the relevance of TCO surface modification to organic electronics, surveys methods for the synthesis of PAs, discusses the modes by which they can bind to TCO surfaces, and compares PAs to alternative organic surface modifiers. The next section discusses methods of PA monolayer deposition, the kinetics of monolayer formation, and structural evidence regarding molecular orientation on TCOs. The next sections discuss TCO work-function modification using PAs, tuning of TCO surface energy using PAs, and initiation of polymerizations from TCO-tethered PAs. Finally, studies that examine the use of PA-modified TCOs in organic light-emitting diodes and organic photovoltaics are compared. © 2016 American Chemical Society.

  11. 'Low-acid' sulfide oxidation using nitrate-enriched groundwater

    Science.gov (United States)

    Donn, Michael; Boxall, Naomi; Reid, Nathan; Meakin, Rebecca; Gray, David; Kaksonen, Anna; Robson, Thomas; Shiers, Denis

    2016-04-01

    Acid drainage (AMD/ARD) is undoubtedly one of the largest environmental, legislative and economic challenges facing the mining industry. In Australia alone, at least 60m is spent on AMD related issues annually, and the global cost is estimated to be in the order of tens of billions US. Furthermore, the challenge of safely and economically storing or treating sulfidic wastes will likely intensify because of the trend towards larger mines that process increasingly higher volumes of lower grade ores and the associated sulfidic wastes and lower profit margins. While the challenge of managing potentially acid forming (PAF) wastes will likely intensify, the industrial approaches to preventing acid production or ameliorating the effects has stagnated for decades. Conventionally, PAF waste is segregated and encapsulated in non-PAF tips to limit access to atmospheric oxygen. Two key limitations of the 'cap and cover' approach are: 1) the hazard (PAF) is not actually removed; only the pollutant linkage is severed; and, 2) these engineered structures are susceptible to physical failure in short-to-medium term, potentially re-establishing that pollutant linkage. In an effort to address these concerns, CSIRO is investigating a passive, 'low-acid' oxidation mechanism for sulfide treatment, which can potentially produce one quarter as much acidity compared with pyrite oxidation under atmospheric oxygen. This 'low-acid' mechanism relies on nitrate, rather than oxygen, as the primary electron accepter and the activity of specifically cultured chemolithoautotrophic bacteria and archaea communities. This research was prompted by the observation that, in deeply weathered terrains of Australia, shallow (oxic to sub-oxic) groundwater contacting weathering sulfides are commonly inconsistent with the geochemical conditions produced by ARD. One key characteristic of these aquifers is the natural abundance of nitrate on a regional scale, which becomes depleted around the sulfide bodies, and

  12. Preparation of fulvic acid and low-molecular organic acids by oxidation of weathered coal humic acid

    Energy Technology Data Exchange (ETDEWEB)

    Shinozuka, T.; Ito, A.; Sasaki, O.; Yazawa, Y.; Yamaguchi, T. [Chiba Institute of Technolgy, Chiba (Japan). Dept. of Industrial Chemistry

    2002-07-01

    Weathered coal contains much humic acid and a little fulvic acid. Therefore, the production of fulvic acid, the most valuable humic substance because of its water-solubility, was examined by ozone and hydrogen peroxide oxidation of humic acid extracted form Xinjiang (China) weathered coal. The resulting products of the oxidation were water soluble fulvic acid and organic acids, mainly formic acid and oxalic acid. The product yield of fulvic acid was 20 (C%) and that of organic acids were 39 (C%) for formic and acid 13 (C%) for oxalic acid. The formed fulvic acid showed a higher content of oxygen and carboxyl groups, than those of the extracted one from the original weathered coal.

  13. Systemic oxidative DNA and RNA damage are not increased during early phases of psychosis

    DEFF Research Database (Denmark)

    Nordholm, Dorte; Poulsen, Henrik Enghusen; Hjorthøj, Carsten

    2016-01-01

    included 41 UHR patients, 35 FES patients, and 29 healthy controls. There was no difference in the level of DNA/RNA oxidative damage between UHR patients and FES patients compared with healthy controls. We found no association between levels of DNA/RNA oxidative damage and perceived stress/life events....... Based on the results, we suggest that DNA and RNA oxidative markers are not increased during the early stages of illness, but further longitudinal studies in first-episode psychosis should be carried out to examine whether DNA and RNA oxidative damage are potential markers of severe illness.......It has been suggested that patients with schizophrenia develop higher levels of oxidative stress, which may contribute to deteriorating mental illness. In order to examine oxidative stress in the early stages of severe mental illness, we examined the levels of systemic Deoxyribonucleic Acid (DNA...

  14. Omega-3 fatty acids differentially modulate enzymatic anti-oxidant systems in skeletal muscle cells.

    Science.gov (United States)

    da Silva, E P; Nachbar, R T; Levada-Pires, A C; Hirabara, S M; Lambertucci, R H

    2016-01-01

    During physical activity, increased reactive oxygen species production occurs, which can lead to cell damage and in a decline of individual's performance and health. The use of omega-3 polyunsaturated fatty acids as a supplement to protect the immune system has been increasing; however, their possible benefit to the anti-oxidant system is not well described. Thus, the aim of this study was to evaluate whether the omega-3 fatty acids (docosahexaenoic acid and eicosapentaenoic acid) can be beneficial to the anti-oxidant system in cultured skeletal muscle cells. C2C12 myocytes were differentiated and treated with either eicosapentaenoic acid or docosahexaenoic acid for 24 h. Superoxide content was quantified using the dihydroethidine oxidation method and superoxide dismutase, catalase, and glutathione peroxidase activity, and expression was quantified. We observed that the docosahexaenoic fatty acids caused an increase in superoxide production. Eicosapentaenoic acid induced catalase activity, while docosahexaenoic acid suppressed superoxide dismutase activity. In addition, we found an increased protein expression of the total manganese superoxide dismutase and catalase enzymes when cells were treated with eicosapentaenoic acid. Taken together, these data indicate that the use of eicosapentaenoic acid may present both acute and chronic benefits; however, the treatment with DHA may not be beneficial to muscle cells.

  15. Polyaniline: Aniline oxidation with strong and weak oxidants under various acidity

    Energy Technology Data Exchange (ETDEWEB)

    Bláha, Michal, E-mail: blaha@imc.cas.cz [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, 162 06 Prague 6 (Czech Republic); Trchová, Miroslava; Bober, Patrycja; Morávková, Zuzana [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, 162 06 Prague 6 (Czech Republic); Prokeš, Jan [Charles University, Faculty of Mathematics and Physics, 180 00 Prague 8 (Czech Republic); Stejskal, Jaroslav [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, 162 06 Prague 6 (Czech Republic)

    2017-06-15

    Aniline was oxidized with three strong inorganic oxidants (ammonium peroxydisulfate, cerium(IV) sulfate, potassium dichromate), two weak inorganic oxidants (iron(III) chloride, silver nitrate), and one organic oxidant (p-benzoquinone) in aqueous solutions of methanesulfonic acid (MSA) of various concentration. Whereas oxidation of aniline with ammonium peroxydisulfate yielded high-molecular-weight conducting polyaniline (PANI) in the whole acidity range, the oxidation with cerium(IV) sulfate led also to a single product close to PANI with considerably lower molecular weight and lower conductivity. Potassium dichromate gave PANI only at high concentration of MSA. The use of iron(III) chloride yielded composite mixtures of PANI and low-molecular-weight aniline oligomers. The oxidation of aniline with silver nitrate led to composites of silver and an organic part, which was constituted either by aniline oligomers or conducting polyaniline or both. p-Benzoquinone as oxidant produced mainly aniline oligomers with poor conductivity and 2,5-dianilino-p-benzoquinone-like structure detected in FTIR and Raman spectra when oxidation proceeded with weak oxidants. A general model of oxidation with strong and weak oxidants was formulated. - Highlights: • Comparison of aniline oxidation with oxidants of different redox potential. • UV–vis, FTIR and Raman spectroscopies combined with size-exclusion chromatography. • The contents of polymer and oligomers were analyzed and discussed. • General model of aniline oxidation with strong and weak oxidants was formulated.

  16. Overexpression of Fatty-Acid-β-Oxidation-Related Genes Extends the Lifespan of Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Shin-Hae Lee

    2012-01-01

    Full Text Available A better understanding of the aging process is necessary to ensure that the healthcare needs of an aging population are met. With the trend toward increased human life expectancies, identification of candidate genes affecting the regulation of lifespan and its relationship to environmental factors is essential. Through misexpression screening of EP mutant lines, we previously isolated several genes extending lifespan when ubiquitously overexpressed, including the two genes encoding the fatty-acid-binding protein and dodecenoyl-CoA delta-isomerase involved in fatty-acid β-oxidation, which is the main energy resource pathway in eukaryotic cells. In this study, we analyzed flies overexpressing the two main components of fatty-acid β-oxidation, and found that overexpression of fatty-acid-β-oxidation-related genes extended the Drosophila lifespan. Furthermore, we found that the ability of dietary restriction to extend lifespan was reduced by the overexpression of fatty-acid-β-oxidation-related genes. Moreover, the overexpression of fatty-acid-β-oxidation-related genes enhanced stress tolerance to oxidative and starvation stresses and activated the dFOXO signal, indicating translocation to the nucleus and transcriptional activation of the dFOXO target genes. Overall, the results of this study suggest that overexpression of fatty-acid-β-oxidation-related genes extends lifespan in a dietary-restriction-related manner, and that the mechanism of this process may be related to FOXO activation.

  17. Increased oxidative DNA damage in mononuclear leukocytes in vitiligo

    Energy Technology Data Exchange (ETDEWEB)

    Giovannelli, Lisa [Department of Preclinical and Clinical Pharmacology, University of Florence, Viale Pieraccini 6, 50139 Florence (Italy)]. E-mail: lisag@pharm.unifi.it; Bellandi, Serena [Department of Dermatological Sciences, University of Florence, Viale Pieraccini 6, 50139 Florence (Italy); Pitozzi, Vanessa [Department of Preclinical and Clinical Pharmacology, University of Florence, Viale Pieraccini 6, 50139 Florence (Italy); Fabbri, Paolo [Department of Dermatological Sciences, University of Florence, Viale Pieraccini 6, 50139 Florence (Italy); Dolara, Piero [Department of Preclinical and Clinical Pharmacology, University of Florence, Viale Pieraccini 6, 50139 Florence (Italy); Moretti, Silvia [Department of Dermatological Sciences, University of Florence, Viale Pieraccini 6, 50139 Florence (Italy)

    2004-11-22

    Vitiligo is an acquired pigmentary disorder of the skin of unknown aetiology. The autocytotoxic hypothesis suggests that melanocyte impairment could be related to increased oxidative stress. Evidences have been reported that in vitiligo oxidative stress might also be present systemically. We used the comet assay (single cell alkaline gel electrophoresis) to evaluate DNA strand breaks and DNA base oxidation, measured as formamidopyrimidine DNA glycosylase (FPG)-sensitive sites, in peripheral blood cells from patients with active vitiligo and healthy controls. The basal level of oxidative DNA damage in mononuclear leukocytes was increased in vitiligo compared to normal subjects, whereas DNA strand breaks (SBs) were not changed. This alteration was not accompanied by a different capability to respond to in vitro oxidative challenge. No differences in the basal levels of DNA damage in polymorphonuclear leukocytes were found between patients and healthy subjects. Thus, this study supports the hypothesis that in vitiligo a systemic oxidative stress exists, and demonstrates for the first time the presence of oxidative alterations at the nuclear level. The increase in oxidative DNA damage shown in the mononuclear component of peripheral blood leukocytes from vitiligo patients was not particularly severe. However, these findings support an adjuvant role of antioxidant treatment in vitiligo.

  18. Increased oxidative stress in patients with familial Mediterranean ...

    African Journals Online (AJOL)

    0.05) comparing to HC group. However, there were no statistically significant differences between the groups in terms of antioxidant vitamin levels. Conclusions: Our study demonstrated increased oxidative stress in patients with FMF during AP.

  19. Increased oxidant status in children with breath-holding spells.

    Science.gov (United States)

    Calik, Mustafa; Abuhandan, Mahmut; Aycicek, Ali; Taskin, Abdullah; Selek, Sahabettin; Iscan, Akin

    2013-06-01

    Breath-holding spells (BHS) are the most common form of non-epileptic paroxysmal events in infancy. The pathophysiology of BHS is not fully understood. Iron-deficiency anemia (IDA) may be a factor contributing to breath-holding spells. Although numerous reports have shown that elevated oxidative stress is implicated in the pathophysiology of neurodegenerative diseases and neurological conditions, such as epileptic seizures, brain damage, and neurotrauma, there are no data regarding the role of oxidative stress in the development of BHS. This study aimed to investigate oxidative stress in children with BHS. This case-control study was conducted at the Department of Pediatric Neurology, Harran University School of Medicine, Sanliurfa, in Turkey. Blood samples from 31 patients (14 females, 17 males) with BHS which were taken at least 24 h after the BHS attack, and a control group of 35 healthy individuals (13 females, 22 males) were used for the measurement of the plasma total antioxidant capacity, total oxidant status, and oxidative stress index, hemoglobin concentration, serum iron, transferrin saturation and serum ferritin levels. The plasma total antioxidant capacity values were markedly lower and total oxidant status and oxidative stress index values in the BHS group were significantly higher than that in the controls (P ≤ 0.01). Our data suggest that the value of oxidative stress was significantly higher in patients with BHS than in the controls. Conditions associated with increased oxidative stress such as IDA may be a risk factor for the development of BHS.

  20. The effect of valinomycin in fibroblasts from patients with fatty acid oxidation disorders

    Energy Technology Data Exchange (ETDEWEB)

    Ndukwe Erlingsson, Uzochi Chimdinma [Division of Medical Genetics, Department of Pediatrics, University of Utah, 2C412 SOM, 50 North Mario Capecchi Drive, Salt Lake City, UT 84132 (United States); Iacobazzi, Francesco [Division of Medical Genetics, Department of Pediatrics, University of Utah, 2C412 SOM, 50 North Mario Capecchi Drive, Salt Lake City, UT 84132 (United States); Department of Basic Medical Sciences, University of Bari, Piazza Giulio Cesare 11, Policlinico, I-70124 Bari (Italy); Liu, Aiping [ARUP Institute for Clinical and Experimental Pathology, ARUP Laboratories, 500 Chipeta Way, Salt Lake City, UT 84108 (United States); Ardon, Orly; Pasquali, Marzia [Division of Medical Genetics, Department of Pediatrics, University of Utah, 2C412 SOM, 50 North Mario Capecchi Drive, Salt Lake City, UT 84132 (United States); ARUP Institute for Clinical and Experimental Pathology, ARUP Laboratories, 500 Chipeta Way, Salt Lake City, UT 84108 (United States); Department of Pathology, University of Utah, Salt Lake City, UT 84132 (United States); Longo, Nicola, E-mail: Nicola.Longo@hsc.utah.edu [Division of Medical Genetics, Department of Pediatrics, University of Utah, 2C412 SOM, 50 North Mario Capecchi Drive, Salt Lake City, UT 84132 (United States); ARUP Institute for Clinical and Experimental Pathology, ARUP Laboratories, 500 Chipeta Way, Salt Lake City, UT 84108 (United States); Department of Pathology, University of Utah, Salt Lake City, UT 84132 (United States)

    2013-08-09

    Highlights: •Valinomycin can cause mitochondrial stress and stimulate fatty acid oxidation. •Cells with VLCAD deficiency fail to increase fatty acid oxidation in response to valinomycin. •Response to valinomycin can help in the diagnosis of VLCAD deficiency. -- Abstract: Disorders of the carnitine cycle and of the beta oxidation spiral impair the ability to obtain energy from fats at time of fasting and stress. This can result in hypoketotic hypoglycemia, cardiomyopathy, cardiac arrhythmia and other chronic medical problems. The in vitro study of fibroblasts from patients with these conditions is impaired by their limited oxidative capacity. Here we evaluate the capacity of valinomycin, a potassium ionophore that increases mitochondrial respiration, to increase the oxidation of fatty acids in cells from patients with inherited fatty acid oxidation defects. The addition of valinomycin to fibroblasts decreased the accumulation of the lipophilic cation tetraphenylphosphonium (TPP{sup +}) at low concentrations due to the dissipation of the mitochondrial membrane potential. At higher doses, valinomycin increased TPP{sup +} accumulation due to the increased potassium permeability of the plasma membrane and subsequent cellular hyperpolarization. The incubation of normal fibroblasts with valinomycin increased [{sup 14}C]-palmitate oxidation (measured as [{sup 14}C]O{sub 2} release) in a dose-dependent manner. By contrast, valinomycin failed to increase palmitate oxidation in fibroblasts from patients with very long chain acyl CoA dehydrogenase (VLCAD) deficiency. This was not observed in fibroblasts from patients heterozygous for this condition. These results indicate that valinomycin can increase fatty acid oxidation in normal fibroblasts and could be useful to differentiate heterozygotes from patients affected with VLCAD deficiency.

  1. Sodium Picosulfate, Magnesium Oxide, and Anhydrous Citric Acid

    Science.gov (United States)

    Sodium picosulfate, magnesium oxide, and anhydrous citric acid combination powder is used to empty the colon (large ... clear view of the walls of the colon. Sodium picosulfate is in a class of medications called ...

  2. Salvianolic acid B Relieves Oxidative Stress in Glucose Absorption ...

    African Journals Online (AJOL)

    levels of ROS as well as antioxidant enzyme activity were determined. Results: ... Keywords: Salvianolic acid B, Blood glucose, Reactive oxygen species, Oxidative stress, Sugar diet. Tropical .... dismutase (SOD), glutathione peroxidase (GSH-.

  3. Increased fat oxidation and regulation of metabolic genes with ultraendurance exercise

    DEFF Research Database (Denmark)

    Helge, Jørn Wulff; Rehrer, N J; Pilegaard, H

    2007-01-01

    AIM: Regular endurance exercise stimulates muscle metabolic capacity, but effects of very prolonged endurance exercise are largely unknown. This study examined muscle substrate availability and utilization during prolonged endurance exercise, and associated metabolic genes. METHODS: Data were...... exercise markedly increases plasma fatty acid availability and fat utilization during exercise. Exercise-induced regulation of genes encoding proteins involved in fatty acid recruitment and oxidation may contribute to these changes....

  4. Picolinic acid promoted oxidative decarboxylation of ...

    African Journals Online (AJOL)

    The kinetics and mechanism of picolinic acid promoted reaction of phenylsulfinylacetic acid (PSAA) with Cr(VI) was carried out in aqueous acetonitrile medium under pseudo first order conditions. The reaction follows Michaelis-Menten type of kinetics with respect to PSAA. The catalytic activity by picolinic acid can be ...

  5. Ferrous iron oxidation by Thiobacillus ferrooxidans: inhibition with benzoic acid, sorbic acid and sodium lauryl sulfate

    Energy Technology Data Exchange (ETDEWEB)

    Onysko, S.J.

    1984-07-01

    Acid mine drainage is formed by the weathering or oxidation of pyritic material exposed during coal mining. The rate of pyritic material oxidation can be greatly accelerated by certain acidophilic bacteria such as Thiobacillus ferrooxidans which catalyse the oxidation of ferrous to ferric iron. A number of organic compounds, under laboratory conditions, can apparently inhibit both the oxidation of ferrous to ferric iron by T. ferrooxidans and the weathering of pyritic material by mixed cultures of acid mine drainage micro-organisms. Sodium lauryl sulphate (SLS), an anionic surfactant has proved effective in this respect. Benzoic acid, sorbic acid and SLS at low concentrations, each effectively inhibited bacterial oxidation of ferrous iron in batch cultures of T. ferrooxidans. The rate of chemical oxidation of ferrous iron in low pH, sterile, batch reactors was not substantially affected at the tested concentrations of any of the compounds.

  6. catalyzed oxidation of some amino acids by acid bromate

    African Journals Online (AJOL)

    Preferred Customer

    Srivastava, S., Tripathi, H. and Singh, K. (2001). Ruthenium(III) Catalysed oxidation of glycerol by acidified KBrO3.Transition Metal. Chemistry 26:727–729. 19. Subramanian, N. Venkata and Thiagarajan, V. (1969). Kinetics and mechanism of ruthenium tetroxide catalysed oxidation of cyclic alcohols by bromate in a base.

  7. Metabolic Fate of the Increased Yeast Amino Acid Uptake Subsequent to Catabolite Derepression

    Directory of Open Access Journals (Sweden)

    John S. Hothersall

    2013-01-01

    Full Text Available Catabolite repression (CCR regulates amino acid permeases in Saccharomyces cerevisiae via a TOR-kinase mediated mechanism. When glucose, the preferred fuel in S. cerevisiae, is substituted by galactose, amino acid uptake is increased. Here we have assessed the contribution and metabolic significance of this surfeit of amino acid in yeast undergoing catabolite derepression (CDR. L-[U-14C]leucine oxidation was increased 15 ± 1 fold in wild type (WT strain grown in galactose compared to glucose. Under CDR, leucine oxidation was (i proportional to uptake, as demonstrated by decreased uptake and oxidation of leucine in strains deleted of major leucine permeases and (ii entirely dependent upon the TCA cycle, as cytochrome c1 (Cyt1 deleted strains could not grow in galactose. A regulator of amino acid carbon entry into the TCA cycle, branched chain ketoacid dehydrogenase, was also increased 29 ± 3 fold under CCR in WT strain. Protein expression of key TCA cycle enzymes, citrate synthase (Cs, and Cyt1 was increased during CDR. In summary, CDR upregulation of amino acid uptake is accompanied by increased utilization of amino acids for yeast growth. The mechanism for this is likely to be an increase in protein expression of key regulators of the TCA cycle.

  8. Ferrous iron oxidation by Thiobacillus ferrooxidans: inhibition with benzoic acid, sorbic acid, and sodium lauryl sulfate

    Energy Technology Data Exchange (ETDEWEB)

    Onysko, S.J.; Kleinmann, R.L.P.; Erickson, P.M.

    1984-07-01

    Thiobacillus ferrooxidans promote indirect oxidation of pyrite through the catalysis of the oxidation of ferrous iron to ferric iron, which is an effective oxidant of pyrite. These bacteria also may catalyze direct oxidation of pyrite by oxygen. A number of organic compounds, under laboratory conditions, can apparently inhibit both the oxidation of ferrous iron to ferric iron by T. ferrooxidans and the weathering of pyritic material by mixed cultures of acid mine drainage microorganisms. In this study, benzoic acid, sorbic acid, and sodium lauryl sulfate at low concentrations (5 to 10 mg/liter) each effectively inhibited bacterial oxidation of ferrous iron in batch cultures of Thiobacillus ferrooxidans. The rate of chemical oxidation of ferrous iron in low-pH, sterile batch reactors was not substantially affected at the tested concentrations (5 to 50 mg/liter) of any of the compounds.

  9. Catalytic wet peroxide oxidation of formic acid in wastewater with ...

    African Journals Online (AJOL)

    2016-07-03

    Jul 3, 2016 ... ABSTRACT. The catalytic wet oxidation of formic acid, using hydrogen peroxide as the oxidizing agent over naturally-occurring iron ore, was explored. Firstly, the decomposition of hydrogen peroxide to its hydroxyl radicals (HO• and HOO•) over naturally-occurring iron ore was investigated. The reaction was ...

  10. Catalytic wet peroxide oxidation of formic acid in wastewater with ...

    African Journals Online (AJOL)

    The catalytic wet oxidation of formic acid, using hydrogen peroxide as the oxidizing agent over naturally-occurring iron ore, was explored. Firstly, the decomposition of hydrogen peroxide to its hydroxyl radicals (HO• and HOO•) over naturally-occurring iron ore was investigated. The reaction was monitored by ATR FTIR by ...

  11. Humic acids of vermicompost as an ecological pathway to increase ...

    African Journals Online (AJOL)

    This paper discussed the potential role of humic acids (HA) in preventing oxidative stress in rice plants submitted to water stress. The rice seedlings (Oryza sativa L. cv. IACUB-30) was grown in nutrient solution and HA were extracted from vermicompost and analysed using Fourier-transform infrared (FTIR) spectroscopic ...

  12. Increased cortical nitric oxide release after phencyclidine administration.

    Science.gov (United States)

    Pålsson, Erik; Finnerty, Niall; Fejgin, Kim; Klamer, Daniel; Wass, Caroline; Svensson, Lennart; Lowry, John

    2009-12-01

    Phencyclidine exerts psychotomimetic effects in humans and is used as a pharmacological animal model for schizophrenia. We, and others, have demonstrated that phencyclidine induces cognitive deficits in rats that are associated with schizophrenia. These cognitive deficits can be normalized by inhibition of nitric oxide synthase. The development of selective microelectrochemical nitric oxide sensors may provide direct evidence for the involvement of nitric oxide in these effects. The aim of the present study was to use LIVE (long term in vivo electrochemistry) to investigate the effect of phencyclidine, alone or in combination with the nitric oxide synthase inhibitor L-NAME, on nitric oxide levels in the medial prefrontal cortex of freely moving rats. Phencyclidine (2 mg kg(-1)) produced an increase in cortical nitric oxide levels and this increase was ameliorated by L-NAME (10 mg kg(-1)). Tentatively, the results from the present study provide a biochemical rationale for the involvement of nitric oxide in the phencyclidine model of schizophrenia. (c) 2009 Wiley-Liss, Inc.

  13. Reduction of hydrogen peroxide stress derived from fatty acid beta-oxidation improves fatty acid utilization in Escherichia coli.

    Science.gov (United States)

    Doi, Hidetaka; Hoshino, Yasushi; Nakase, Kentaro; Usuda, Yoshihiro

    2014-01-01

    Fatty acids are a promising raw material for substance production because of their highly reduced and anhydrous nature, which can provide higher fermentation yields than sugars. However, they are insoluble in water and are poorly utilized by microbes in industrial fermentation production. We used fatty acids as raw materials for L-lysine fermentation by emulsification and improved the limited fatty acid-utilization ability of Escherichia coli. We obtained a fatty acid-utilizing mutant strain by laboratory evolution and demonstrated that it expressed lower levels of an oxidative-stress marker than wild type. The intracellular hydrogen peroxide (H₂O₂) concentration of a fatty acid-utilizing wild-type E. coli strain was higher than that of a glucose-utilizing wild-type E. coli strain. The novel mutation rpsA(D210Y) identified in our fatty acid-utilizing mutant strain enabled us to promote cell growth, fatty-acid utilization, and L-lysine production from fatty acid. Introduction of this rpsA(D210Y) mutation into a wild-type strain resulted in lower H₂O₂ concentrations. The overexpression of superoxide dismutase (sodA) increased intracellular H₂O₂ concentrations and inhibited E. coli fatty-acid utilization, whereas overexpression of an oxidative-stress regulator (oxyS) decreased intracellular H₂O₂ concentrations and promoted E. coli fatty acid utilization and L-lysine production. Addition of the reactive oxygen species (ROS) scavenger thiourea promoted L-lysine production from fatty acids and decreased intracellular H₂O₂ concentrations. Among the ROS generated by fatty-acid β-oxidation, H₂O₂ critically affected E. coli growth and L-lysine production. This indicates that the regression of ROS stress promotes fatty acid utilization, which is beneficial for fatty acids used as raw materials in industrial production.

  14. Skeletal muscle fatty acid oxidation is not directly associated with AMPK or ACC2 phosphorylation.

    Science.gov (United States)

    Alkhateeb, Hakam; Holloway, Graham P; Bonen, Arend

    2011-06-01

    Rescue of palmitate-induced insulin resistance has been linked with improvements in fatty acid oxidation, but importantly, not always with concurrently altered AMPK or ACC2 phosphorylation. Therefore, we examined the interrelationships among AMPK, ACC2, and fatty acid oxidation under 12 controlled conditions in isolated muscle. Incubation of soleus muscle (0-12 h) did not alter fatty acid oxidation, but did increase AMPK and ACC2 phosphorylation (24%-30%). Muscle incubation with palmitate (2 mmol·L(-1)) inhibited palmitate oxidation (∼55%), but paradoxically, this was associated with increased AMPK and ACC2 phosphorylation (∼50%). Addition of an AMPK activator (thujone) to control (no palmitate) muscle increased AMPK and ACC2 phosphorylation (∼25%) but did not alter palmitate oxidation. Addition of AMPK inhibitors, compound C (50 µmol·L(-1)) or adenine 9-β-d-arabinofuranoside (Ara; 2.5 mmol·L(-1)), to thujone-treated muscles (no palmitate) did not alter palmiate oxidation but reduced AMPK phosphorylation (32%-42%), while ACC2 phosphorylation remained above basal level (+14%-18%). Finally, in palmitate-treated muscle, thujone increased AMPK (+100%) and ACC2 phosphorylation (+52%) and restored palmitate oxidation. Compound C or Ara, administered along with thujone in palmitate-treated muscle, only partly blunted palmitate oxidation recovery despite inhibiting AMPK phosphorylation (-22%), although ACC2 phosphorylation remained upregulated (+33%). Among these experiments, AMPK phosphorylation and ACC2 phosphorylation were positively correlated. However, AMPK phosphorylation was not correlated with palmitate oxidation, and unexpectedly, palmitate oxidation was negatively correlated with ACC2 phosphorylation. Our study, in accordance with a growing body of evidence, indicates that neither AMPK phosphorylation nor ACC2 phosphorylation is by itself an appropriate marker of fatty acid oxidation, and further serves to question their regulatory role.

  15. Platinum nanoparticles–manganese oxide nanorods as novel binary catalysts for formic acid oxidation

    Directory of Open Access Journals (Sweden)

    Mohamed S. El-Deab

    2012-01-01

    Full Text Available The current study proposes a novel binary catalyst system (composed of metal/metal oxide nanoparticles as a promising electrocatalyst in formic acid oxidation. The electro-catalytic oxidation of formic acid is carried out with binary catalysts of Pt nanoparticles (nano-Pt and manganese oxide nanorods (nano-MnOx electrodeposited onto glassy carbon (GC electrodes. Cyclic voltammetric (CV measurements showed that unmodified GC and nano-MnOx/GC electrodes have no catalytic activity. While two oxidation peaks were observed at nano-Pt/GC electrode at ca. 0.2 and 0.55 V (corresponding to the direct oxidation of formic acid and the oxidation of the poisoning CO intermediate, respectively. The combined use of nano-MnOx and nano-Pt results in superb enhancement of the direct oxidation pathway. Nano-MnOx is shown to facilitate the oxidation of CO (to CO2 by providing oxygen at low over-potential. This leads to retrieval of Pt active sites necessary for the direct oxidation of formic acid. The higher catalytic activity of nano-MnOx/nano-Pt/GC electrode (with Pt firstly deposited compared to its mirror image electrode (i.e., with MnOx firstly deposited, nano-Pt/nano-MnOx/GC reveals that the order of the electrodeposition is an essential parameter.

  16. The effects of fatty acid composition on lipid oxidation, protein oxidation and color stability in minced pork

    OpenAIRE

    Liu, Miao

    2017-01-01

    The literature review covers different aspects of lipid oxidation and protein oxidation in meat.The mechanism of lipid and protein oxidation, factors influencing lipid oxidation, the consequences of protein oxidation, measurement methods, and the interactions between lipid oxidation, protein oxidation and meat color are introduced. The present thesis was aiming to study the effects of different fatty acid composition on lipid oxidation, protein oxidation and meat color in minced pork st...

  17. Cardiac fatty acid oxidation in heart failure associated with obesity and diabetes.

    Science.gov (United States)

    Fukushima, Arata; Lopaschuk, Gary D

    2016-10-01

    Obesity and diabetes are major public health problems, and are linked to the development of heart failure. Emerging data highlight the importance of alterations in cardiac energy metabolism as a major contributor to cardiac dysfunction related to obesity and diabetes. Increased rates of fatty acid oxidation and decreased rates of glucose utilization are two prominent changes in cardiac energy metabolism that occur in obesity and diabetes. This metabolic profile is probably both a cause and consequence of a prominent cardiac insulin resistance, which is accompanied by a decrease in both cardiac function and efficiency, and by the accumulation of potentially toxic lipid metabolites in the heart that can further exaggerate insulin resistance and cardiac dysfunction. The high cardiac fatty acid oxidation rates seen in obesity and diabetes are attributable to several factors, including: 1) increased fatty acid supply and uptake into the cardiomyocyte, 2) increased transcription of fatty acid metabolic enzymes, 3) decreased allosteric control of mitochondrial fatty acid uptake and fatty acid oxidation, and 4) increased post-translational acetylation control of various fatty acid oxidative enzymes. Emerging evidence suggests that therapeutic approaches aimed at switching the balance of cardiac energy substrate preference from fatty acid oxidation to glucose use can prevent cardiac dysfunction associated with obesity and diabetes. Modulating acetylation control of fatty acid oxidative enzymes is also a potentially attractive strategy, although presently this is limited to precursors of nicotinamide adenine or nonspecific activators of deacetylation such as resveratrol. This review will focus on the metabolic alterations in the heart that occur in obesity and diabetes, as well as on the molecular mechanisms controlling these metabolic changes. This article is part of a Special Issue entitled: Heart Lipid Metabolism edited by G.D. Lopaschuk. Copyright © 2016 Elsevier B

  18. Does Furosemide Increase Oxidative Stress in Acute Kidney Injury?

    Science.gov (United States)

    Silbert, Benjamin I; Ho, Kwok M; Lipman, Jeffrey; Roberts, Jason A; Corcoran, Tomas B; Morgan, David J; Pavey, Warren; Mas, Emilie; Barden, Anne E; Mori, Trevor A

    2017-02-10

    Furosemide, a loop diuretic, is used to increase urine output in patients with acute kidney injury (AKI). It remains uncertain whether the benefits of furosemide in AKI outweigh its potential harms. We investigated if furosemide influenced oxidative stress in 30 critically ill patients with AKI by measuring changes in F 2 -isoprostanes (F 2 -IsoPs), markers of in vivo oxidative stress, in plasma and urine following intravenous furosemide. Urine F 2 -IsoPs were higher in sepsis (p = 0.001) and increased in proportion to urine furosemide (p = 0.001). The furosemide-induced increase in urine F 2 -IsoPs differed depending on AKI severity (p Furosemide had no effect on plasma F 2 -IsoPs. We demonstrate for the first time that furosemide increases renal oxidative stress in AKI and find that patients with the most severe AKI-to whom the largest doses are likely to be administered-showed the greatest increase in oxidative stress. These findings lead to the hypothesis that the common practice of administering high-dose furosemide to convert oliguric to nonoliguric AKI may induce harmful oxidative stress in the kidneys, and an adequately powered, randomized controlled trial is required to determine if clinical benefits of this dosing strategy justify its potential harms. Antioxid. Redox Signal. 26, 221-226.

  19. Acute supplementation of amino acids increases net protein accretion in IUGR fetal sheep.

    Science.gov (United States)

    Brown, Laura D; Rozance, Paul J; Thorn, Stephanie R; Friedman, Jacob E; Hay, William W

    2012-08-01

    Placental insufficiency decreases fetal amino acid uptake from the placenta, plasma insulin concentrations, and protein accretion, thus compromising normal fetal growth trajectory. We tested whether acute supplementation of amino acids or insulin into the fetus with intrauterine growth restriction (IUGR) would increase net fetal protein accretion rates. Late-gestation IUGR and control (CON) fetal sheep received acute, 3-h infusions of amino acids (with euinsulinemia), insulin (with euglycemia and euaminoacidemia), or saline. Fetal leucine metabolism was measured under steady-state conditions followed by a fetal muscle biopsy to quantify insulin signaling. In CON, increasing amino acid delivery rates to the fetus by 100% increased leucine oxidation rates by 100%. In IUGR, amino acid infusion completely suppressed fetal protein breakdown rates but increased leucine oxidation rate by only 25%, resulting in increased protein accretion rates by 150%. Acute insulin infusion, however, had very little effect on amino acid delivery rates, fetal leucine disposal rates, or fetal protein accretion rates in CON or IUGR fetuses despite robust signaling of the fetal skeletal muscle insulin-signaling cascade. These results indicate that, when amino acids are given directly into the fetal circulation independently of changes in insulin concentrations, IUGR fetal sheep have suppressed protein breakdown rates, thus increasing net fetal protein accretion.

  20. Kinetics of Oxidation of 3-Benzoylpropionic Acid by N-Chlorobenzamide in Aqueous Acetic Acid Medium

    Directory of Open Access Journals (Sweden)

    N. A. Mohamed Farook

    2011-01-01

    Full Text Available The kinetics of oxidation of 3-benzoylpropionic acid (KA by N-chlorobenzamide (NCB in aqueous acetic acid medium in the presence of perchloric acid have been investigated. The observed rate of oxidation is first order dependence each in [KA], [NCB] and [H+]. The main product of the oxidation is the corresponding carboxylic acid. The rate decreases with the addition of benzamide, one of the products of the reaction. Variation in ionic strength of the reaction medium has no significant effect on the rate of oxidation. But the rate of the reaction is enhanced by lowering the dielectric constant of the reaction medium. Hypochlorous acidium ion (H2O+Cl, has been postulated as the reactive oxidizing species. A mechanism consistent with observed results have been proposed and the related rate law deduced. The activation parameters have been computed with respect to slow step of the mechanism.

  1. Effect of heating on oxidation stability and fatty acid composition of microwave roasted groundnut seed oil.

    Science.gov (United States)

    Abbas Ali, M; Anowarul Islam, M; Othman, Noor Hidayu; Noor, Ahmadilfitri Md

    2017-12-01

    The oxidative stability and fatty acid composition of groundnut seed oil (GSO) exposed to microwaves were evaluated during heating at 170 °C. During heating, the oxidative indices such as free fatty acid, peroxide value, p -anisidine value, TOTOX, thiobarbituric acid value, specific extinctions, and color value were increased. The increments were found to be higher in unroasted seed oils compared to roasted ones indicating lower release of lipid oxidation products in roasted GSO. After 9 h heating, the relative content of polyunsaturated fatty acid (PUFA) decreased to 89.53% and that of saturated fatty acid (SFA) increased to 117.46% in unroasted sample. The relative content of PUFA decreased to 92.05% and that of SFA increased to 105.76% in 7.5 min roasted sample after 9 h of heating. However, the roasting process slowed down the oxidative deterioration of PUFA. With increased heating times, an appreciable loss was more apparent in the triacylglycerol species OLL and OOL in unroasted samples compared to roasted ones. In FTIR, the peak intensities in unroasted samples were markedly changed in comparison with roasted samples during heating. The roasting of groundnut seed prior to the oil extraction reduced the oxidative degradation of oil samples; thereby increasing heat stability.

  2. Oxidation of furan fatty acids by soybean lipoxygenase-1 in the presence of linoleic acid.

    Science.gov (United States)

    Batna, A; Spiteller, G

    1994-04-19

    The interaction of furan fatty acids (F-acids) with lipoxygenase was investigated by incubation experiments of a synthetic dialkyl-substituted F-acid with soybean lipoxygenase-1. Originally the oxidation of furan fatty acids was assumed to be directly effected by lipoxygenase. It is now demonstrated that this reaction is a two-step process that requires the presence of lipoxygenase substrates, e.g. linoleic acid. In the first step linoleic acid is converted by the enzyme to the corresponding hydroperoxide. This attacks, probably in a radical reaction, the furan fatty acid to produce a dioxoene compound that can be detected unequivocally by gas chromatography-mass spectrometry.

  3. Kinetics and Mechanism of the Oxidation of Lactic Acid and Mandelic Acid by Pyridinium Chlorochromate in Aqueous Acidic Medium

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    Sapana Jain

    2009-01-01

    Full Text Available Pyridinium chlorochromate (PCC act as two electron oxidant in kinetic studies of the oxidation of lactic and mandelic acid in acidic medium. The influence of several factors such as acidity, salts, solvent composition and temperature on the reaction rate has been studied. The reaction shows first order dependence with respect to [PCC] and [H+]. The various thermodynamic parameters have been evaluated. Products as oxoacids and absence of free radical were confirmed. Suitable reaction mechanism has been proposed.

  4. Increased brain nitric oxide levels following ethanol administration.

    Science.gov (United States)

    Finnerty, Niall; O'Riordan, Saidhbhe L; Klamer, Daniel; Lowry, John; Pålsson, Erik

    2015-05-01

    Nitric oxide is a ubiquitous messenger molecule, which at elevated concentrations has been implicated in the pathogenesis of several neurological disorders. Its role in oxidative stress, attributed in particular to the formation of peroxynitrite, proceeds through its high affinity for the superoxide radical. Alcoholism has recently been associated with the induction of oxidative stress, which is generally defined as a shift in equilibrium between pro-oxidant and anti-oxidant species in the direction of the former. Furthermore, its primary metabolite acetaldehyde, has been extensively associated with oxidative damage related toxic effects following alcohol ingestion. The principal objective of this study was the application of long term in vivo electrochemistry (LIVE) to investigate the effect of ethanol (0.125, 0.5 and 2.0 g kg(-1)) and acetaldehyde (12.5, 50 and 200 mg kg(-1)) on NO levels in the nucleus accumbens of freely moving rats. Systemic administrations of ethanol and acetaldehyde resulted in a dose-dependent increases in NO levels, albeit with very differing time courses. Subsequent to this the effect on accumbal NO levels, of subjecting the animal to different drug combinations, was also elucidated. The nitric oxide synthase inhibitor L-NAME (20 mg kg(-1)) and acetaldehyde sequestering agent D-penicillamine (50 mg kg(-1)) both attenuated the increase in NO levels following ethanol (1 g kg(-1)) administration. Conversely, the alcohol dehydrogenase inhibitor 4-methylpyrazole (25 mg kg(-1)) and catalase inhibitor sodium azide (10 mg kg(-1)) potentiated the increase in NO levels following ethanol administration. Finally, dual inhibition of aldehyde dehydrogenase and catalase by cyanamide (25 mg kg(-1)) caused an attenuation of ethanol effects on NO levels. Taken together these data highlight a robust increase in brain NO levels following systemic alcohol administration which is dependent on NO synthase activity and may involve both alcohol- and acetaldehyde

  5. Triiodothyronine activates lactate oxidation without impairing fatty acid oxidation and improves weaning from extracorporeal membrane oxygenation

    Energy Technology Data Exchange (ETDEWEB)

    Kajimoto, Masaki; Ledee, Dolena R.; Xu, Chun; Kajimoto, Hidemi; Isern, Nancy G.; Portman, Michael A.

    2014-01-01

    Background: Extracorporeal membrane oxygenation (ECMO) provides a rescue for children with severe cardiac failure. We previously showed that triiodothyronine (T3) improves cardiac function by modulating pyruvate oxidation during weaning. This study was focused on fatty acid (FA) metabolism modulated by T3 for weaning from ECMO after cardiac injury. Methods: Nineteen immature piglets (9.1-15.3 kg) were separated into 3 groups with ECMO (6.5 hours) and wean: normal circulation (Group-C);transient coronary occlusion (10 minutes) followed by ECMO (Group-IR); and IR with T3 supplementation (Group-IR-T3). 13-Carbon labeled lactate, medium-chain and long-chain FAs were infused as oxidative substrates. Substrate fractional contribution to the citric acid cycle (FC) was analyzed by 13-Carbon nuclear magnetic resonance. Results: ECMO depressed circulating T3 levels to 40% baseline at 4 hours and were restored in Group-IR-T3. Group-IR decreased cardiac power, which was not fully restorable and 2 pigs were lost because of weaning failure. Group-IR also depressed FC-lactate, while the excellent contractile function and energy efficiency in Group-IR-T3 occurred along with a marked FC-lactate increase and [ATP]/[ADP] without either decreasing FC-FAs or elevating myocardial oxygen consumption over Group-C or -IR. Conclusions: T3 releases inhibition of lactate oxidation following ischemia-reperfusion injury without impairing FA oxidation. These findings indicate that T3 depression during ECMO is maladaptive, and that restoring levels improves metabolic flux and enhances contractile function during weaning.

  6. Increased oxidation, glycoxidation, and lipoxidation of brain proteins in prion disease.

    Science.gov (United States)

    Pamplona, Reinald; Naudí, Alba; Gavín, Rosalina; Pastrana, Miguel A; Sajnani, Gustavo; Ilieva, Ekaterina V; Del Río, José Antonio; Portero-Otín, Manuel; Ferrer, Isidre; Requena, Jesús R

    2008-10-15

    The basic molecular underpinnings of the pathological changes that unfold in prion disease remain elusive. A key role of increased oxidative stress has been hypothesized. Given the transient nature of most intermediate molecules implicated, increased oxidative stress is better assessed by quantitating the damage it causes to macromolecules. We used mass spectrometry-based methods to measure specific products of protein oxidation, glycoxidation, and lipoxidation in brains from patients suffering from Creutzfeldt-Jakob disease and Syrian hamsters affected by scrapie. In both cases, increased amounts of glutamic and aminoadipic semialdehydes, products of metal-catalyzed oxidation, malondialdehydelysine (a product of lipoxidation), N-epsilon-carboxyethyllysine (a product of glycoxidation), and N-epsilon-carboxymethyllysine (generated by lipoxidation and glycoxidation) were measured. PrP(Sc), the infectious isoform of the prion protein that accumulates in prion disease, was itself shown to be a target of increased oxidative modification. These changes were accompanied by alterations in fatty acid composition and increased phosphorylation of ERK(1/2) and p38, protein kinases known to respond to increased flows of ROS. These data support an important role of oxidative damage in the pathology of prion disease.

  7. Serum lipid resistance to oxidation and uric acid levels in subjects with Down's syndrome.

    Science.gov (United States)

    Nagyová, A; Sustrová, M; Raslová, K

    2000-01-01

    In subjects with Down's syndrome (DS) increased oxidative stress and consequent oxidative cell damage have been reported. The aim of this study was to assess whether the excessive production of free oxygen radicals in these subjects can affect the copper-induced lipid oxidation resistance measured in fresh whole serum. Since a significant elevation of serum uric acid levels, which is an efficient hydrophilic antioxidant, has been repeatedly reported in subjects with DS, we studied the association between increased serum uric acid levels and lipid resistance to oxidation measured directly in serum samples by monitoring the change in absorbance at 234 nm. The group of subjects with Down's syndrome consisted of 25 individuals (aged 18+/-5 years). Control group included brothers and sisters of subjects with DS (n = 25, aged 17+/-7 years). In subjects with DS, the serum lipid resistance to oxidation (lag time) was significantly higher than in controls (puric acid levels was observed (puric acid concentration was found in subjects with DS (r = 0.48, puric acid levels repeatedly observed in subjects with DS may be associated with an enhanced resistance of serum lipids to oxidation which is thought to play an important role in the atherogenic process.

  8. Increased 5S rRNA oxidation in Alzheimer's disease.

    Science.gov (United States)

    Ding, Qunxing; Zhu, Haiyan; Zhang, Bing; Soriano, Augusto; Burns, Roxanne; Markesbery, William R

    2012-01-01

    It is widely accepted that oxidative stress is involved in neurodegenerative disorders such as Alzheimer's disease (AD). Ribosomal RNA (rRNA) is one of the most abundant molecules in most cells and is affected by oxidative stress in the human brain. Previous data have indicated that total rRNA levels were decreased in the brains of subjects with AD and mild cognitive impairment concomitant with an increase in rRNA oxidation. In addition, level of 5S rRNA, one of the essential components of the ribosome complex, was significantly lower in the inferior parietal lobule (IP) brain area of subjects with AD compared with control subjects. To further evaluate the alteration of 5S rRNA in neurodegenerative human brains, multiple brain regions from both AD and age-matched control subjects were used in this study, including IP, superior and middle temporal gyro, temporal pole, and cerebellum. Different molecular pools including 5S rRNA integrated into ribosome complexes, free 5S rRNA, cytoplasmic 5S rRNA, and nuclear 5S rRNA were studied. Free 5S rRNA levels were significantly decreased in the temporal pole region of AD subjects and the oxidation of ribosome-integrated and free 5S rRNA was significantly increased in multiple brain regions in AD subjects compared with controls. Moreover, a greater amount of oxidized 5S rRNA was detected in the cytoplasm and nucleus of AD subjects compared with controls. These results suggest that the increased oxidation of 5S rRNA, especially the oxidation of free 5S rRNA, may be involved in the neurodegeneration observed in AD.

  9. catalyzed oxidation of some amino acids by acid bromate

    African Journals Online (AJOL)

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    Further, the product analysis by spotting techniques indicates the presence of aldehyde in the reaction mixture. So the product of oxidation should be the glycolic aldehyde (2-hydroxy ethanal) and α-hydroxy propionaldehyde (3- hydroxy propanal) for dl-serine and dl-threonine, respectively. The kinetic results were collected ...

  10. Stereoselective and nonstereoselective effects of ibuprofen enantiomers on mitochondrial beta-oxidation of fatty acids

    Energy Technology Data Exchange (ETDEWEB)

    Freneaux, E.; Fromenty, B.; Berson, A.; Labbe, G.; Degott, C.; Letteron, P.; Larrey, D.; Pessayre, D. (Unite de Recherches de Physiolopathologie Hepatique (INSERM U-24), Hopital Beaujon, Clichy (France))

    1990-11-01

    The effects of the R-(-) and S-(+)ibuprofen enantiomers were first studied in vitro with mouse liver mitochondria incubated in the presence of various concentrations of exogenous coenzyme A. In the presence of a low concentration of coenzyme A (2.5 microM), the R-(-)enantiomer (which forms an acylcoenzyme A) inhibited stereoselectively the beta oxidation of (1-{sup 14}C)palmitic acid but not that of (1-{sup 14}C)palmitoyl-L-carnitine (which can directly enter the mitochondria). In the presence, however, of a concentration of coenzyme A (50 microM) reproducing that present in liver cell cytosol, both enantiomers (2 mM) slightly inhibited the beta oxidation of (1-{sup 14}C)palmitic acid and markedly inhibited the beta oxidation of (1-{sup 14}C)octanoic acid and (1-{sup 14}C)butyric acid. In vivo, both enantiomers (1 mmol.kg-1) similarly inhibited the formation of ({sup 14}C)CO{sub 2} from (1-{sup 14}C)fatty acids. Both enantiomers similarly decreased plasma ketone bodies. Both similarly increased hepatic triglycerides, and both produced mild microvesicular steatosis of the liver. We conclude that both ibuprofen enantiomers inhibit beta oxidation of fatty acids in vitro and in vivo. In addition, the R-(-)enantiomer may stereoselectively sequester coenzyme A; at low concentrations of coenzyme A in vitro, this may stereoselectively inhibit the mitochondrial uptake and beta oxidation of long chain fatty acids.

  11. Increasing dietary fat elicits similar changes in fat oxidation and markers of muscle oxidative capacity in lean and obese humans.

    Directory of Open Access Journals (Sweden)

    Audrey Bergouignan

    Full Text Available In lean humans, increasing dietary fat intake causes an increase in whole-body fat oxidation and changes in genes that regulate fat oxidation in skeletal muscle, but whether this occurs in obese humans is not known. We compared changes in whole-body fat oxidation and markers of muscle oxidative capacity differ in lean (LN and obese (OB adults exposed to a 2-day high-fat (HF diet. Ten LN (BMI = 22.5±2.5 kg/m², age = 30±8 yrs and nine OB (BMI = 35.9±4.93 kg/m², 38±5 yrs, Mean±SD were studied in a room calorimeter for 24hr while consuming isocaloric low-fat (LF, 20% of energy and HF (50% of energy diets. A muscle biopsy was obtained the next morning following an overnight fast. 24h respiratory quotient (RQ did not significantly differ between groups (LN: 0.91±0.01; OB: 0.92±0.01 during LF, and similarly decreased during HF in LN (0.86±0.01 and OB (0.85±0.01. The expression of pyruvate dehydrogenase kinase 4 (PDK4 and the fatty acid transporter CD36 increased in both LN and OB during HF. No other changes in mRNA or protein were observed. However, in both LN and OB, the amounts of acetylated peroxisome proliferator-activated receptor γ coactivator-1-α (PGC1-α significantly decreased and phosphorylated 5-AMP-activated protein kinase (AMPK significantly increased. In response to an isoenergetic increase in dietary fat, whole-body fat oxidation similarly increases in LN and OB, in association with a shift towards oxidative metabolism in skeletal muscle, suggesting that the ability to adapt to an acute increase in dietary fat is not impaired in obesity.

  12. Characteristics of Oxidative Storage Stability of Canola Fatty Acid Methyl Ester Stabilised with Antioxidants

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    Tirto Prakoso

    2012-11-01

    Full Text Available The storage effects on the oxidation characteristics of fatty acid methyl ester of canola oil (CME were investigated in this study. CME stabilised with two antioxidants, i.e. 2,6-di-tert-bytyl-p-cresol (BHT and 6,6-di-tert-butyl-2, 2’-methylendi-p-cresol (BPH, was stored at 20, 40 and 60°C. The oxidation stability data were measured by the Rancimat test method and it was found that both BHT and BPH addition increased the oxidation resistance of the CME. The results showed that when BPH or BHT was added at a concentration of 100 ppm, the oxidation induction period of the neat CME samples increased from 5.53 h to 6.93 h and 6.14 h, respectively. Comparing both antioxidants, BPH proved to be more effective in increasing the oxidation resistance when both antioxidants were added at the same concentration. Furthermore, the oxidation induction time decreased linearly with the storage time. It was shown that the oxidation occurred rapidly in the first 8 weeks of storage. Later, a kinetic study was undertaken and first-order kinetics were applied to explain the oxidation characteristics of the CME added with antioxidants. This kinetic study focused on exploiting the activation energy values obtained from the Arrhenius equations. Also, the oxidation effects on other quality parameters, including acid value, peroxide value, kinematic viscosity, and water content, were examined.

  13. An environment-friendly preparation of reduced graphene oxide nanosheets via amino acid.

    Science.gov (United States)

    Chen, Dezhi; Li, Lidong; Guo, Lin

    2011-08-12

    Chemically modified graphene has been studied in many applications due to its excellent electrical, mechanical, and thermal properties. Among the chemically modified graphenes, reduced graphene oxide is the most important for its structure and properties, which are similar to pristine graphene. Here, we introduce an environment-friendly approach for preparation of reduced graphene oxide nanosheets through the reduction of graphene oxide that employs L-cysteine as the reductant under mild reaction conditions. The conductivity of the reduced graphene oxide nanosheets produced in this way increases by about 10(6) times in comparison to that of graphene oxide. This is the first report about using amino acids as a reductant for the preparation of reduced graphene oxide nanosheets, and this procedure offers an alternative route to large-scale production of reduced graphene oxide nanosheets for applications that require such material.

  14. Increased fluidity and oxidation of malarial lipoproteins: relation with severity and induction of endothelial expression of adhesion molecules

    Directory of Open Access Journals (Sweden)

    Looareesuwan Sornchai

    2004-06-01

    Full Text Available Abstract Introduction Oxidative stress has been demonstrated in malaria. The potential oxidative modification of lipoproteins derived from malaria patients was studied. These oxidized lipids may have role in pathogenesis of malaria. Method The plasma lipid profile and existence of oxidized forms of very low density lipoprotein (VLDL, low density lipoprotein (LDL and high density lipoprotein (HDL were investigated in malaria (17 mild and 24 severe patients and 37 control subjects. Thiobarbituric acid reactive substances (TBARs, conjugated dienes, tryptophan fluorescence and fluidity of lipoproteins were determined as markers of oxidation. The biological effect of malarial lipoproteins was assessed by the expression of adhesion molecules on endothelial cells. Results Malarial lipoproteins had decreased cholesterol (except in VLDL and phospholipid. The triglyceride levels were unchanged. The cholesterol/phospholipid ratio of LDL was decreased in malaria, but increased in VLDL and HDL. TBARs and conjugate dienes were increased in malarial lipoproteins, while the tryptophan fluorescence was decreased. The fluidity of lipoproteins was increased in malaria. These indicated the presence of oxidized lipoproteins in malaria by which the degree of oxidation was correlated with severity. Of three lipoproteins from malarial patients, LDL displayed the most pronounced oxidative modification. In addition, oxidized LDL from malaria patients increased endothelial expression of adhesion molecules. Conclusion In malaria, the lipoproteins are oxidatively modified, and the degree of oxidation is related with severity. Oxidized LDL from malarial patients increases the endothelial expression of adhesion molecules. These suggest the role of oxidized lipoproteins, especially LDL, on the pathogenesis of disease.

  15. Oxidative stress increases in overweight individuals following an exercise test.

    Science.gov (United States)

    Andrews, Anne M; Kantor, Mark A

    2010-12-01

    The objective of this study was to determine whether the Army Physical Fitness Test (APFT) causes oxidative stress and evaluate the impact of dietary antioxidant intake, fitness level, and body composition on changes in oxidative stress. Forty-seven overweight subjects were asked to perform an APFT. Creatine kinase (CK), C-reactive protein (CRP), glutathione peroxidase (GPX), and superoxide dismutase (SOD) were measured before, immediately after, and 24 hr postexercise. CK significantly increased immediately postexercise and at 24 hr postexercise. CRP and GPX significantly increased immediately postexercise, whereas SOD did not change significantly. Antioxidant intake, fitness level, and body composition were found to significantly influence changes in CK, GPX, and SOD after exercise. In conclusion, the APFT causes oxidative stress in overweight subjects. The associations between dietary antioxidants, fitness level, and body composition seen with each of the biomarkers provide support for future research in this area.

  16. Lipid oxidation and fatty acid composition in salt-dried yellow croaker ( Pseudosciaena polyactis) during processing

    Science.gov (United States)

    Cai, Qiuxing; Wu, Yanyan; Li, Laihao; Wang, Yueqi; Yang, Xianqing; Zhao, Yongqiang

    2017-10-01

    Lipid oxidation in salt-dried yellow croaker ( Pseudosciaena polyactis) was evaluated during processing with commonly used analytical indices, such as the peroxide value (POV), the thiobarbituric acid reactive substances (TBARS) value, and oxidative-relative lipoxygenase (LOX) activity. Additionally, fatty acids were analyzed using gas chromatography-mass spectrometry. Both POV and TBARS increased significantly ( P lipid oxidation. C18:0, C16:1n7, C19:0, and C22:6n3 showed clear changes in principle component one of a principle components analysis. These fatty acids are potential markers for evaluating lipid oxidation in fish muscle because there was a significant correlation between these markers and TBARS and LOX activity ( P 0.931.

  17. Retinol oxidation to retinoic acid in human thyroid glandular cells.

    Science.gov (United States)

    Taibi, Gennaro; Gueli, Maria Concetta; Nicotra, Concetta M A; Cocciadiferro, Letizia; Carruba, Giuseppe

    2014-12-01

    Abstract Retinoic acid is regarded as the retinol metabolite that controls proliferation and differentiation of epithelial cells. In the present study, we investigated the potential role of xanthine dehydrogenase (XDH) in retinoic acid biosynthesis in human thyroid glandular cells (HTGC). In particular, we observed that cellular retinoids binding proteins (CRBPs) are also implicated in the biosynthetic pathway leading to retinoic acid formation in primary cultures of HTGC, as we have already reported for human mammary epithelial cells (HMEC). After partial protein purification, the enzyme responsible for retinoic acid biosynthesis was identified and quantified as XDH by immunoassay, by its ability to oxidize xanthine to uric acid and its sensitivity to the inhibitory effect of oxypurinol. The evidence of XDH-driven formation of retinoic acid in HTGC cultures further corroborates the potential role of XDH in retinoic acid biosynthesis in the epithelia.

  18. Oxidative acid treatment and characterization of new biocarbon from sustainable Miscanthus biomass

    Energy Technology Data Exchange (ETDEWEB)

    Anstey, Andrew [Bioproducts Discovery and Development Centre (BDDC), Department of Plant Agriculture, Crop Science Building, University of Guelph, Guelph, ON N1G 2W1 (Canada); School of Engineering, Thornbrough Building, University of Guelph, Guelph, ON N1G 2W1 (Canada); Vivekanandhan, Singaravelu [Bioproducts Discovery and Development Centre (BDDC), Department of Plant Agriculture, Crop Science Building, University of Guelph, Guelph, ON N1G 2W1 (Canada); Sustainable Materials and Nanotechnology Lab, Department of Physics, VHNSN College, Virudhunagar 626 001, Tamilnadu (India); Rodriguez-Uribe, Arturo [Bioproducts Discovery and Development Centre (BDDC), Department of Plant Agriculture, Crop Science Building, University of Guelph, Guelph, ON N1G 2W1 (Canada); Misra, Manjusri [Bioproducts Discovery and Development Centre (BDDC), Department of Plant Agriculture, Crop Science Building, University of Guelph, Guelph, ON N1G 2W1 (Canada); School of Engineering, Thornbrough Building, University of Guelph, Guelph, ON N1G 2W1 (Canada); Mohanty, Amar Kumar, E-mail: mohanty@uoguelph.ca [Bioproducts Discovery and Development Centre (BDDC), Department of Plant Agriculture, Crop Science Building, University of Guelph, Guelph, ON N1G 2W1 (Canada); School of Engineering, Thornbrough Building, University of Guelph, Guelph, ON N1G 2W1 (Canada)

    2016-04-15

    Oxidative acid treatments of biochar produced from Miscanthus were performed in this study using nitric acid, sulfuric acid, and a mixture of both. The structural and morphological changes of the acid-treated biochar were investigated using Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Raman spectroscopy, organic elemental analysis and energy-dispersive X-ray spectroscopy (EDS). Improved surface functionality of the treated biochars was observed in their respective FT-IR spectra through the presence of nitro and carboxylic acid functional groups. SEM–EDS and elemental analysis revealed a large increase in the oxygen to carbon ratio in the biochar, which was evidence of chemical oxidation from the acid treatment. Further, TGA study showed the reduced thermal stability of acid-treated biochar over 200 °C due to the increased oxygen content. Acid treatments also influenced the graphitic structure of the biochar, as observed in the Raman spectra. The results suggest that biochar can be successfully functionalized for composite applications and provide a sustainable alternative to petroleum-based carbon additives. - Highlights: • Biochar was investigated as a candidate for renewable functionalized carbon. • Oxidative acid treatment was used to modify the carbon structure. • The chemical and morphological properties of the treated biochar were examined. • Successful chemical modification of biochar was verified through characterization. • Biochar shows potential as a sustainable carbon additive for polymer composites.

  19. Advanced oxidation of acid and reactive dyes

    DEFF Research Database (Denmark)

    Arslan-Alaton, I.; Gursoy, B.H.; Schmidt, Jens Ejbye

    2008-01-01

    The effect of untreated and Fenton-treated acid dyes (C.I. Acid Red 183 and C.I. Acid Orange 51) and a reactive dye (C.I. Reactive Blue 4) on aerobic, anoxic and anaerobic processes was investigated. The optimum Fe2+:H2O2 molar ratio was selected as 1:5 (4:hsp sp="0.25" mM:20:hsp sp="0.25"m...... for the untreated blue, red and orange dyes, respectively. The inhibitory effect of the blue reactive dye on methane production was ∼21% after Fenton treatment. Neither untreated nor treated dyes exhibited an inhibitory effect on denitrification. Aerobic glucose degradation was inhibited by 23-29% by untreated dyes......, whereas Fenton-treated dyes had no inhibitory effect on aerobic glucose degradation....

  20. Increased oxidative DNA damage, 8-hydroxydeoxy- guanosine, in human pterygium.

    Science.gov (United States)

    Kau, H-C; Tsai, C-C; Lee, C-F; Kao, S-C; Hsu, W-M; Liu, J-H; Wei, Y-H

    2006-07-01

    Chronic exposure to ultraviolet (UV) light is a widely accepted aetiological factor in the development of pterygium. UV radiation may induce production of reactive oxygen species via photosensitized oxidation, thus causing oxidative damage. This study was conducted to test the hypothesis that oxidative damage to DNA is increased in pterygium. Immunohistochemical analysis employing a monoclonal antibody specific for 8-hydroxy-2'-deoxyguanosine (8-OHdG), a ubiquitous maker of oxidative stress, was performed in three patients with primary pterygium. The levels of 8-OHdG in DNA isolated from the other 29 pterygium specimens and their adjacent normal conjunctival tissues were determined using enzyme-linked immunosorbent assay (ELISA). Immunohistochemistry of 8-OHdG showed a distinct pattern of more extensive and intense staining in the nuclei of pterygium tissue compared with that in their adjacent normal conjunctiva. ELISA also revealed that the average level of 8-OHdG in the pterygium tissues was 4.7-fold higher than that of the corresponding normal conjunctiva (P<0.001). The increased levels of 8-OHdG in the pterygium tissues indicate that oxidative stress could play a role in the development of pterygium. These findings provide new information to better understand the pathogenesis of pterygium and are useful in the prevention and treatment of this disease.

  1. Dietary fatty acids and oxidative stress in the heart mitochondria.

    Science.gov (United States)

    Lemieux, Hélène; Bulteau, Anne Laure; Friguet, Bertrand; Tardif, Jean-Claude; Blier, Pierre U

    2011-01-01

    Our study compared the effects of different oils on oxidative stress in rat heart mitochondria, as well as on plasma parameters used as risk factors for cardiovascular disease. The rats were fed for 16 weeks with coconut, olive, or fish oil diet (saturated, monounsaturated, or polyunsaturated fatty acids, respectively). The cardiac mitochondria from rats fed with coconut oil showed the lowest concentration of oxidized proteins and peroxidized lipids. The fish oil diet leads to the highest oxidative stress in cardiac mitochondria, an effect that could be partly prevented by the antioxidant probucol. Total and LDL cholesterols decreased in plasma of rats fed fish oil, compared to olive and coconut oils fed rats. A diet enriched in saturated fatty acids offers strong advantages for the protection against oxidative stress in heart mitochondria. Copyright © 2010 Mitochondria Research Society. Published by Elsevier B.V. All rights reserved.

  2. Corrosion behaviour of AISI type 304L stainless steel in nitric acid media containing oxidizing species

    Energy Technology Data Exchange (ETDEWEB)

    Ningshen, S. [Corrosion Science and Technology Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Kamachi Mudali, U., E-mail: kamachi@igcar.gov.i [Corrosion Science and Technology Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Ramya, S.; Raj, Baldev [Corrosion Science and Technology Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India)

    2011-01-15

    Research highlights: Corrosion behaviour of 304L stainless steel has been evaluated in the presence of oxidizing species in nitric acid medium. No significant change in corrosion potential even with increase in temperature and nitric acid concentration in presence of oxidizing ions. Faster passive film dissolution as indicated by low film polarization resistance, with increase in nitric acid concentration and temperature. The presence of oxidizing species further aggravates the corrosion of 304L SS along with increased temperature and nitric acid concentration. - Abstract: The corrosion behaviour of AISI type 304L stainless steel (SS) in different concentration of 0.01 M, 1 M and 5 M HNO{sub 3} in presence of oxidizing ions at different temperatures has been evaluated. The main objective of this study is to assess the corrosion resistance of type 304L SS in non-radioactive conditions encountered during storage of liquid nuclear waste. Electrochemical impedance spectroscopy (EIS) and laser Raman spectroscopy (LRS) has clearly brought out the deleterious effect of oxidizing species on the passive film leading to increased corrosion along with increase in HNO{sub 3} concentration and higher temperature.

  3. Fatty Acid Oxidation and Cardiovascular Risk during Menopause: A Mitochondrial Connection?

    Directory of Open Access Journals (Sweden)

    Paulo J. Oliveira

    2012-01-01

    Full Text Available Menopause is a consequence of the normal aging process in women. This fact implies that the physiological and biochemical alterations resulting from menopause often blur with those from the aging process. It is thought that menopause in women presents a higher risk for cardiovascular disease although the precise mechanism is still under discussion. The postmenopause lipid profile is clearly altered, which can present a risk factor for cardiovascular disease. Due to the role of mitochondria in fatty acid oxidation, alterations of the lipid profile in the menopausal women will also influence mitochondrial fatty acid oxidation fluxes in several organs. In this paper, we propose that alterations of mitochondrial bioenergetics in the heart, consequence from normal aging and/or from the menopausal process, result in decreased fatty acid oxidation and accumulation of fatty acid intermediates in the cardiomyocyte cytosol, resulting in lipotoxicity and increasing the cardiovascular risk in the menopausal women.

  4. Development of marker-free transgenic Jatropha plants with increased levels of seed oleic acid

    Directory of Open Access Journals (Sweden)

    Qu Jing

    2012-02-01

    Full Text Available Abstract Background Jatropha curcas is recognized as a new energy crop due to the presence of the high amount of oil in its seeds that can be converted into biodiesel. The quality and performance of the biodiesel depends on the chemical composition of the fatty acids present in the oil. The fatty acids profile of the oil has a direct impact on ignition quality, heat of combustion and oxidative stability. An ideal biodiesel composition should have more monounsaturated fatty acids and less polyunsaturated acids. Jatropha seed oil contains 30% to 50% polyunsaturated fatty acids (mainly linoleic acid which negatively impacts the oxidative stability and causes high rate of nitrogen oxides emission. Results The enzyme 1-acyl-2-oleoyl-sn-glycero-3-phosphocholine delta 12-desaturase (FAD2 is the key enzyme responsible for the production of linoleic acid in plants. We identified three putative delta 12 fatty acid desaturase genes in Jatropha (JcFAD2s through genome-wide analysis and downregulated the expression of one of these genes, JcFAD2-1, in a seed-specific manner by RNA interference technology. The resulting JcFAD2-1 RNA interference transgenic plants showed a dramatic increase of oleic acid (> 78% and a corresponding reduction in polyunsaturated fatty acids (Jatropha had around 37% oleic acid and 41% polyunsaturated fatty acids. This indicates that FAD2-1 is the major enzyme responsible for converting oleic acid to linoleic acid in Jatropha. Due to the changes in the fatty acids profile, the oil of the JcFAD2-1 RNA interference seed was estimated to yield a cetane number as high as 60.2, which is similar to the required cetane number for conventional premium diesel fuels (60 in Europe. The presence of high seed oleic acid did not have a negative impact on other Jatropha agronomic traits based on our preliminary data of the original plants under greenhouse conditions. Further, we developed a marker-free system to generate the transgenic Jatropha

  5. Ferrous Iron Oxidation by Thiobacillus ferrooxidans: Inhibition with Benzoic Acid, Sorbic Acid, and Sodium Lauryl Sulfate

    Science.gov (United States)

    Onysko, Steven J.; Kleinmann, Robert L. P.; Erickson, Patricia M.

    1984-01-01

    Benzoic acid, sorbic acid, and sodium lauryl sulfate at low concentrations (5 to 10 mg/liter) each effectively inhibited bacterial oxidation of ferrous iron in batch cultures of Thiobacillus ferrooxidans. The rate of chemical oxidation of ferrous iron in low-pH, sterile batch reactors was not substantially affected at the tested concentrations (5 to 50 mg/liter) of any of the compounds. PMID:16346592

  6. Comparison between conjugated linoleic acid and essential fatty acids in preventing oxidative stress in bovine mammary epithelial cells.

    Science.gov (United States)

    Basiricò, L; Morera, P; Dipasquale, D; Tröscher, A; Bernabucci, U

    2017-03-01

    Some in vitro and in vivo studies have demonstrated protective effects of conjugated linoleic acid (CLA) isomers against oxidative stress and lipid peroxidation. However, only a few and conflicting studies have been conducted showing the antioxidant potential of essential fatty acids. The objectives of the study were to compare the effects of CLA to other essential fatty acids on the thiol redox status of bovine mammary epithelia cells (BME-UV1) and their protective role against oxidative damage on the mammary gland by an in vitro study. The BME-UV1 cells were treated with complete medium containing 50 μM of cis-9,trans-11 CLA, trans-10,cis-12 CLA, α-linolenic acid, γ-linolenic acid, and linoleic acid. To assess the cellular antioxidant response, glutathione, NADPH, and γ-glutamyl-cysteine ligase activity were measured 48 h after addition of fatty acids (FA). Intracellular reactive oxygen species and malondialdehyde production were also assessed in cells supplemented with FA. Reactive oxygen species production after 3 h of H2O2 exposure was assessed to evaluate and to compare the potential protection of different FA against H2O2-induced oxidative stress. All FA treatments induced an intracellular GSH increase, matched by high concentrations of NADPH and an increase of γ-glutamyl-cysteine ligase activity. Cells supplemented with FA showed a reduction in intracellular malondialdehyde levels. In particular, CLA isomers and linoleic acid supplementation showed a better antioxidant cellular response against oxidative damage induced by H2O2 compared with other FA. The Authors. Published by the Federation of Animal Science Societies and Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).

  7. Increased carnitine-dependent fatty acid uptake into mitochondria of human colon cancer cells induces apoptosis.

    Science.gov (United States)

    Wenzel, Uwe; Nickel, Alexander; Daniel, Hannelore

    2005-06-01

    Carnitine-dependent fatty acid import into mitochondria and beta-oxidation seem to be impaired in tumor cells. In the present study we show that a supply of palmitoylcarnitine together with L-carnitine potently induces apoptosis in HT-29 human colon cancer cells as a consequence of accelerated fatty acid oxidation. Caspase-3-like activities, measured by the cleavage rate of a fluorogenic tetrapeptide substrate and nuclear fragmentation determined after DNA labeling in fixed cells by fluorescence microscopy, served as indicators of apoptosis. Neither L-carnitine nor palmitoylcarnitine alone were able to increase caspase-3-like activities and DNA fragmentation, but when provided together, apoptosis occurred. That exogenous carnitine was indeed able to enhance fatty acid uptake into mitochondria was demonstrated by an increased influx of a fluorescent palmitic acid analog. Enhanced fatty acid availability in mitochondria led to an increased generation of O*2-, as detected by a O*2- -sensitive fluorogenic dye, indicating oxidation of delivered substrates. Benzoquinone, an O*2- scavenger, blocked O*2- generation and prevented apoptosis as initiated by the combination of palmitoylcarnitine and carnitine. The lack of effect of the ceramide synthesis inhibitor fumonisin on palmitoylcarnitine/carnitine-induced apoptosis further supports the notion that apoptotic cell death is specifically due to fatty acid oxidation. In contrast to HT-29 cells, nontransformed human colonocytes did not respond to exogenous palmitoylcarnitine/carnitine and no apoptosis was observed. In conclusion, our studies provide evidence that a limited mitochondrial fatty acid import in human colon cancer cells prevents high rates of mitochondrial O*2- production and protects colon cancer cells from apoptosis that can be overcome by an exogenous carnitine supply.

  8. Myocardial metabolism during hypoxia: Maintained lactate oxidation during increased glycolysis

    Energy Technology Data Exchange (ETDEWEB)

    Mazer, C.D.; Stanley, W.C.; Hickey, R.F.; Neese, R.A.; Cason, B.A.; Demas, K.A.; Wisneski, J.A.; Gertz, E.W. (Univ. of California, San Francisco (USA))

    1990-09-01

    In the intact animal, myocardial lactate utilization and oxidation during hypoxia are not well understood. Nine dogs were chronically instrumented with flow probes on the left anterior descending coronary artery and with a coronary sinus sampling catheter. ({sup 14}C)lactate and ({sup 13}C)glucose tracers, or ({sup 13}C)lactate and ({sup 14}C)glucose were administered to quantitate lactate and glucose oxidation, lactate conversion to glucose, and simultaneous lactate extraction and release. The animals were anesthetized and exposed to 90 minutes of severe hypoxia (PO2 = 25 +/- 4 torr). Hypoxia resulted in significant increases in heart rate, cardiac output and myocardial blood flow, but no significant change in myocardial oxygen consumption. The arterial/coronary sinus differences for glucose and lactate did not change from normoxia to hypoxia; however, the rate of glucose uptake increased significantly due to the increase in myocardial blood flow. Tracer-measured lactate extraction did not decrease with hypoxia, despite a 250% increase in lactate release. During hypoxia, 90% +/- 4% of the extracted {sup 14}C-lactate was accounted for by the appearance of {sup 14}CO{sub 2} in the coronary sinus, compared with 88% +/- 4% during normoxia. Thus, in addition to the expected increase in glucose uptake and lactate production, we observed an increase in lactate oxidation during hypoxia.

  9. Impact of Fluorescent Lighting on Oxidation of Model Wine Solutions Containing Organic Acids and Iron.

    Science.gov (United States)

    Grant-Preece, Paris; Barril, Celia; Schmidtke, Leigh M; Clark, Andrew C

    2017-03-22

    Previous studies have provided evidence that light exposure can increase oxygen consumption in wine and that the photodegradation of iron(III) tartrate could contribute to this process. In the present study, model wine solutions containing iron(III) and various organic acids, either alone or combined, were stored in sealed clear glass wine bottles and exposed to light from fluorescent lamps. Dissolved oxygen was monitored, and afterward the organic acid degradation products were determined and the capacity of the solutions to bind sulfur dioxide, the main wine preservative, was assessed. In the dark controls, little or no dissolved oxygen was consumed and the organic acids were stable. In the irradiated solutions, dissolved oxygen was consumed at a rate that was dependent on the specific organic acid present, and the latter were oxidized to various carbonyl compounds. For the solutions containing tartaric acid, malic acid, and/or citric acid, irradiation increased their sulfur dioxide-binding capacity.

  10. Pyrite oxidation under simulated acid rain weathering conditions.

    Science.gov (United States)

    Zheng, Kai; Li, Heping; Wang, Luying; Wen, Xiaoying; Liu, Qingyou

    2017-07-31

    We investigated the electrochemical corrosion behavior of pyrite in simulated acid rain with different acidities and at different temperatures. The cyclic voltammetry, polarization curve, and electrochemical impedance spectroscopy results showed that pyrite has the same electrochemical interaction mechanism under different simulated acid rain conditions, regardless of acidity or environmental temperature. Either stronger acid rain acidity or higher environmental temperature can accelerate pyrite corrosion. Compared with acid rain having a pH of 5.6 at 25 °C, the prompt efficiency of pyrite weathering reached 104.29% as the acid rain pH decreased to 3.6, and it reached 125.31% as environmental temperature increased to 45 °C. Increasing acidity dramatically decreases the charge transfer resistance, and increasing temperature dramatically decreases the passivation film resistance, when other conditions are held constant. Acid rain always causes lower acidity mine drainage, and stronger acidity or high environmental temperatures cause serious acid drainage. The natural parameters of latitude, elevation, and season have considerable influence on pyrite weathering, because temperature is an important influencing factor. These experimental results are of direct significance for the assessment and management of sulfide mineral acid drainage in regions receiving acid rain.

  11. Supercritical water oxidation of acrylic acid production wastewater.

    Science.gov (United States)

    Gong, Y M; Wang, S Z; Tang, X Y; Xu, D H; Ma, H H

    2014-01-01

    Supercritical water oxidation (SCWO) of wastewater from an acrylic acid manufacturing plant has been studied on a continuous flow experimental system, whose reactor was made of Hastelloy C-276. Experimental conditions included a reaction temperature (T) ranging from 673 to 773K, a residence time (t) ranging from 72.7 to 339s, a constant pressure (P) of 25 MPa and a fixed oxidation coefficient (alpha) of 2.0. Experimental results indicated that reaction temperature and residence time had significant influences on the oxidation reaction, and increasing the two operation parameters could improve both degradation of chemical oxygen demand (COD) and ammonia nitrogen (NH3-N). The COD removal efficiency could reach up to 98.73% at 25 MPa, 773 K and 180.1 s, whereas the destruction efficiency of NH3-N was only 43.71%. We further carried out a kinetic analysis considering the induction period through free radical chain mechanism. It confirms that the power-law rate equation for COD removal was 345 exp(-52200/RT)[COD]1.98[O2]0.17 and for NH3-N removal was 500 exp(-64492.19/RT)[NH3-N]1.87 [O2]0.03. Moreover, the induction time formulations for COD and NH3-N were suspected to be exp(38250/RT)/173 and exp(55690/RT)/15231, respectively. Correspondingly, induction time changed from 2.22 to 5.38 s for COD and 0.38 to 1.38 s for NH3-N. Owing to the catalysis of reactor inner wall surface, more than 97% COD removal was achieved in all samples.

  12. Aerosol Fragmentation Driven by Coupling of Acid-Base and Free-Radical Chemistry in the Heterogeneous Oxidation of Aqueous Citric Acid by OH Radicals.

    Science.gov (United States)

    Liu, Matthew J; Wiegel, Aaron A; Wilson, Kevin R; Houle, Frances A

    2017-08-10

    A key uncertainty in the heterogeneous oxidation of carboxylic acids by hydroxyl radicals (OH) in aqueous-phase aerosol is how the free-radical reaction pathways might be altered by acid-base chemistry. In particular, if acid-base reactions occur concurrently with acyloxy radical formation and unimolecular decomposition of alkoxy radicals, there is a possibility that differences in reaction pathways impact the partitioning of organic carbon between the gas and aqueous phases. To examine these questions, a kinetic model is developed for the OH-initiated oxidation of citric acid aerosol at high relative humidity. The reaction scheme, containing both free-radical and acid-base elementary reaction steps with physically validated rate coefficients, accurately predicts the experimentally observed molecular composition, particle size, and average elemental composition of the aerosol upon oxidation. The difference between the two reaction channels centers on the reactivity of carboxylic acid groups. Free-radical reactions mainly add functional groups to the carbon skeleton of neutral citric acid, because carboxylic acid moieties deactivate the unimolecular fragmentation of alkoxy radicals. In contrast, the conjugate carboxylate groups originating from acid-base equilibria activate both acyloxy radical formation and carbon-carbon bond scission of alkoxy radicals, leading to the formation of low molecular weight, highly oxidized products such as oxalic and mesoxalic acid. Subsequent hydration of carbonyl groups in the oxidized products increases the aerosol hygroscopicity and accelerates the substantial water uptake and volume growth that accompany oxidation. These results frame the oxidative lifecycle of atmospheric aerosol: it is governed by feedbacks between reactions that first increase the particle oxidation state, then eventually promote water uptake and acid-base chemistry. When coupled to free-radical reactions, acid-base channels lead to formation of low molecular

  13. Acetylsalicylic acid and acetaminophen protect against oxidative neurotoxicity.

    Science.gov (United States)

    Maharaj, H; Maharaj, D S; Daya, S

    2006-09-01

    Due to the implication of oxidative stress in neurodegenerative disorders we decided to investigate the antioxidant properties of acetylsalicylic acid and acetaminophen either alone or in combination. The thiobarbituric acid assay (TBA) and the nitroblue tetrazolium (NBT) assay were used to investigate quinolinic acid (QA)-induced: lipid peroxidation and superoxide anion generation in the rat hippocampus, in vivo. The study also shows, using cresyl violet staining, the preservation of structural integrity of neuronal cells following treatment with acetylsalicylic acid and acetaminophen in QA-lesioned rat hippocampus. Furthermore the study sought to determine whether these agents have any effect on endogenous (QA) formation. This study shows that acetylsalicylic acid and acetaminophen inhibit QA-induced superoxide anion generation, lipid peroxidation and cell damage, in vivo, in the rat hippocampus. In addition these agents inhibit the enzyme, 3-hydroxyanthranilic acid oxygenase (3-HAO), responsible for the synthesis of endogenous QA.

  14. Fatty acid oxidation and carnitine palmitoyltransferase I: emerging therapeutic targets in cancer.

    Science.gov (United States)

    Qu, Q; Zeng, F; Liu, X; Wang, Q J; Deng, F

    2016-05-19

    Tumor cells exhibit unique metabolic adaptations that are increasingly viewed as potential targets for novel and specific cancer therapies. Among these targets, the carnitine palmitoyltransferase system is responsible for delivering the long-chain fatty acid (FA) from cytoplasm into mitochondria for oxidation, where carnitine palmitoyltransferase I (CPTI) catalyzes the rate-limiting step of fatty acid oxidation (FAO). With increasing understanding of the crucial role had by fatty acid oxidation in cancer, CPTI has received renewed attention as a pivotal mediator in cancer metabolic mechanism. CPTI activates FAO and fuels cancer growth via ATP and NADPH production, constituting an essential part of cancer metabolism adaptation. Moreover, CPTI also functionally intertwines with other key pathways and factors to regulate gene expression and apoptosis of cancer cell. Here, we summarize recent findings and update the current understanding of FAO and CPTI in cancer and provide theoretical basis for this enzyme as an emerging potential molecular target in cancer therapeutic intervention.

  15. An Increase in the Omega-6/Omega-3 Fatty Acid Ratio Increases the Risk for Obesity

    Science.gov (United States)

    Simopoulos, Artemis P.

    2016-01-01

    In the past three decades, total fat and saturated fat intake as a percentage of total calories has continuously decreased in Western diets, while the intake of omega-6 fatty acid increased and the omega-3 fatty acid decreased, resulting in a large increase in the omega-6/omega-3 ratio from 1:1 during evolution to 20:1 today or even higher. This change in the composition of fatty acids parallels a significant increase in the prevalence of overweight and obesity. Experimental studies have suggested that omega-6 and omega-3 fatty acids elicit divergent effects on body fat gain through mechanisms of adipogenesis, browning of adipose tissue, lipid homeostasis, brain-gut-adipose tissue axis, and most importantly systemic inflammation. Prospective studies clearly show an increase in the risk of obesity as the level of omega-6 fatty acids and the omega-6/omega-3 ratio increase in red blood cell (RBC) membrane phospholipids, whereas high omega-3 RBC membrane phospholipids decrease the risk of obesity. Recent studies in humans show that in addition to absolute amounts of omega-6 and omega-3 fatty acid intake, the omega-6/omega-3 ratio plays an important role in increasing the development of obesity via both AA eicosanoid metabolites and hyperactivity of the cannabinoid system, which can be reversed with increased intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). A balanced omega-6/omega-3 ratio is important for health and in the prevention and management of obesity. PMID:26950145

  16. An Increase in the Omega-6/Omega-3 Fatty Acid Ratio Increases the Risk for Obesity

    Directory of Open Access Journals (Sweden)

    Artemis P. Simopoulos

    2016-03-01

    Full Text Available In the past three decades, total fat and saturated fat intake as a percentage of total calories has continuously decreased in Western diets, while the intake of omega-6 fatty acid increased and the omega-3 fatty acid decreased, resulting in a large increase in the omega-6/omega-3 ratio from 1:1 during evolution to 20:1 today or even higher. This change in the composition of fatty acids parallels a significant increase in the prevalence of overweight and obesity. Experimental studies have suggested that omega-6 and omega-3 fatty acids elicit divergent effects on body fat gain through mechanisms of adipogenesis, browning of adipose tissue, lipid homeostasis, brain-gut-adipose tissue axis, and most importantly systemic inflammation. Prospective studies clearly show an increase in the risk of obesity as the level of omega-6 fatty acids and the omega-6/omega-3 ratio increase in red blood cell (RBC membrane phospholipids, whereas high omega-3 RBC membrane phospholipids decrease the risk of obesity. Recent studies in humans show that in addition to absolute amounts of omega-6 and omega-3 fatty acid intake, the omega-6/omega-3 ratio plays an important role in increasing the development of obesity via both AA eicosanoid metabolites and hyperactivity of the cannabinoid system, which can be reversed with increased intake of eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA. A balanced omega-6/omega-3 ratio is important for health and in the prevention and management of obesity.

  17. Oxidative cleavage of erucic acid for the synthesis of brassylic acid

    Energy Technology Data Exchange (ETDEWEB)

    Mohammed J. Nasrullah; Pooja Thapliyal; Erica N. Pfarr; Nicholas S. Dusek; Kristofer L. Schiele; James A. Bahr

    2010-10-29

    The main focus of this work is to synthesize Brassylic Acid (BA) using oxidative cleavage of Erucic Acid (EA). Crambe (Crambe abyssinica) is an industrial oilseed grown in North Dakota. Crambe has potential as an industrial fatty acid feedstock as a source of Erucic acid (EA). It has approximately 50-60 % of EA, a C{sub 22} monounsaturated fatty acid. Oxidative cleavage of unsaturated fatty acids derived from oilseeds produces long chain (9, 11, and 13 carbon atoms) dibasic and monobasic acids. These acids are known commercial feedstocks for the preparation of nylons, polyesters, waxes, surfactants, and perfumes. Other sources of EA are Rapeseed seed oil which 50-60 % of EA. Rapeseed is grown outside USA. The oxidative cleavage of EA was done using a high throughput parallel pressure reactor system. Kinetics of the reaction shows that BA yields reach a saturation at 12 hours. H{sub 2}WO{sub 4} was found to be the best catalyst for the oxidative cleavage of EA. High yields of BA were obtained at 80 C with bubbling of O{sub 2} or 10 bar of O{sub 2} for 12 hours.

  18. PPAR{delta} is a fatty acid sensor, which enhances mitochondrial oxidation in insulin

    DEFF Research Database (Denmark)

    Ravnskjaer, Kim; Frigerio, Francesca; Boergesen, Michael

    2010-01-01

    is the PPAR subtype expressed at the highest level in insulinoma cells and rat pancreatic islets. Furthermore, PPARdelta displays high transcriptional activity and acts in pronounced synergy with RXR. Interestingly, unsaturated fatty acids mimic the effects of synthetic PPARdelta agonists. Using shRNA......-mediated knockdown we demonstrate that the ability of unsaturated fatty acids to stimulate fatty acid metabolism is dependent on PPARdelta. Activation of PPARdelta increases the fatty acid oxidation potential in INS-1E beta-cells, enhances glucose-stimulated insulin secretion (GSIS) from islets, and protects GSIS...

  19. Enzymatic Browning in Sugar Beet Leaves (Beta vulgaris L.): Influence of Caffeic Acid Derivatives, Oxidative Coupling, and Coupled Oxidation.

    Science.gov (United States)

    Vissers, Anne; Kiskini, Alexandra; Hilgers, Roelant; Marinea, Marina; Wierenga, Peter Alexander; Gruppen, Harry; Vincken, Jean-Paul

    2017-06-21

    Sugar beet (Beta vulgaris L.) leaves of 8 month (8m) plants showed more enzymatic browning than those of 3 month (3m). Total phenolic content increased from 4.6 to 9.4 mg/g FW in 3m and 8m, respectively, quantitated by reverse-phase-ultrahigh-performance liquid chromatography-ultraviolet-mass spectrometry (RP-UHPLC-UV-MS). The PPO activity was 6.7 times higher in extracts from 8m than from 3m leaves. Substrate content increased from 0.53 to 2.45 mg/g FW in 3m and 8m, respectively, of which caffeic acid glycosyl esters were most important, increasing 10-fold with age. Caffeic acid glycosides and vitexin derivatives were no substrates. In 3m and 8m, nonsubstrate-to-substrate ratios were 8:1 and 3:1, respectively. A model system showed browning at 3:1 ratio due to formation of products with extensive conjugated systems through oxidative coupling and coupled oxidation. The 8:1 ratio did not turn brown as oxidative coupling occurred without much coupled oxidation. We postulate that differences in nonsubstrate-to-substrate ratio and therewith extent of coupled oxidation explain browning.

  20. Erythrocyte Sialic Acid Content during Aging in Humans: Correlation with Markers of Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Mohammad Murtaza Mehdi

    2012-01-01

    Full Text Available Sialic acids are substituted neuraminic acid derivatives which are typically found at the outermost end of glycan chains on the membrane in all cell types. The role of erythrocyte membrane sialic acids during aging has been established however the relationship between sialic acid and oxidative stress is not fully understood. The present work was undertaken to analyze the relationship between erythrocyte membrane sialic acid with its plasma level, membrane and plasma lipid hydroperoxide levels and plasma total antioxidant capacity. Results show that sialic acid content decreases significantly (P < 0.001 in RBC membrane (r = −0.901 and increases in plasma (r = 0.860 as a function of age in humans. Lipid peroxidation measured in the form of hydroperoxides increases significantly (P < 0.001 in plasma (r = 0.830 and RBC membranes (r = 0.875 with age in humans. The Trolox Equivalent Total Antioxidant Capacity (TETAC of plasma was found to be significantly decreased (P < 0.001, r = −0.844. We observe significant correlations between decrease of erythrocyte membrane sialic acid and plasma lipid hydroperoxide and TETAC. Based on the observed correlations, we hypothesize that increase in oxidative stress during aging may influence the sialic acid decomposition from membrane thereby altering the membrane configuration affecting many enzymatic and transporter activities. Considering the importance of plasma sialic acid as a diagnostic parameter, it is important to establish age-dependent reference.

  1. Nivalenol induces oxidative stress and increases deoxynivalenol pro-oxidant effect in intestinal epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Del Regno, Marisanta; Adesso, Simona; Popolo, Ada [Department of Pharmacy, School of Pharmacy, University of Salerno, Via Giovanni Paolo II, 132–84084 Fisciano, Salerno (Italy); Quaroni, Andrea [Department of Biomedical Sciences, Cornell University, Veterinary Research Tower, Cornell University, Ithaca, NY 14853–6401 (United States); Autore, Giuseppina [Department of Pharmacy, School of Pharmacy, University of Salerno, Via Giovanni Paolo II, 132–84084 Fisciano, Salerno (Italy); Severino, Lorella [Department of Pathology and Animal Health, Division of Toxicology, School of Veterinary Medicine, University of Naples “Federico II”, Via Delpino 1, 80137 Naples (Italy); Marzocco, Stefania, E-mail: smarzocco@unisa.it [Department of Pharmacy, School of Pharmacy, University of Salerno, Via Giovanni Paolo II, 132–84084 Fisciano, Salerno (Italy)

    2015-06-01

    Mycotoxins are secondary fungal metabolites often found as contaminants in almost all agricultural commodities worldwide, and the consumption of food or feed contaminated by mycotoxins represents a major risk for human and animal health. Reactive oxygen species are normal products of cellular metabolism. However, disproportionate generation of reactive oxygen species poses a serious problem to bodily homeostasis and causes oxidative tissue damage. In this study we analyzed the effect of two trichothecenes mycotoxins: nivalenol and deoxynivalenol, alone and in combination, on oxidative stress in the non-tumorigenic intestinal epithelial cell line IEC-6. Our results indicate the pro-oxidant nivalenol effect in IEC-6, the stronger pro-oxidant effect of nivalenol when compared to deoxynivalenol and, interestingly, that nivalenol increases deoxynivalenol pro-oxidative effects. Mechanistic studies indicate that the observed effects were mediated by NADPH oxidase, calcium homeostasis alteration, NF-kB and Nrf2 pathways activation and by iNOS and nitrotyrosine formation. The toxicological interaction by nivalenol and deoxynivalenol reported in this study in IEC-6, points out the importance of the toxic effect of these mycotoxins, mostly in combination, further highlighting the risk assessment process of these toxins that are of growing concern. - Highlights: • Nivalenol induces oxidative stress in intestinal epithelial cells (IECs). • Nivalenol increases deoxynivalenol pro-oxidant effects in IECs. • Nivalenol and deoxynivalenol trigger antioxidant response IECs. • These results indicate the importance of mycotoxins co-contamination.

  2. Increasing NADH oxidation reduces overflow metabolism in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Vemuri, Goutham; Eiteman, M.A; McEwen, J.E

    2007-01-01

    Crabtree effect.’’ The yeast Saccharomyces cerevisiae has served as an important model organism for studying the Crabtree effect. When subjected to increasing glycolytic fluxes under aerobic conditions, there is a threshold value of the glucose uptake rate at which the metabolism shifts from purely...... effect is due to limited respiratory capacity or is caused by glucose-mediated repression of respiration. When respiration in S. cerevisiae was increased by introducing a heterologous alternative oxidase, we observed reduced aerobic ethanol formation. In contrast, increasing nonrespiratory NADH oxidation...... NADH dehydrogenases in S. cerevisiae. These results indicate that NADH oxidase localizes in the cytosol, whereas alternative oxidase is directed to the mitochondria....

  3. Current issues regarding treatment of mitochondrial fatty acid oxidation disorders

    NARCIS (Netherlands)

    Spiekerkoetter, Ute; Bastin, Jean; Gillingham, Melanie; Morris, Andrew; Wijburg, Frits; Wilcken, Bridget

    2010-01-01

    Treatment recommendations in mitochondrial fatty acid oxidation (FAO) defects are diverse. With implementation of newborn screening and identification of asymptomatic patients, it is necessary to define whom to treat and how strictly. We here discuss critical questions that are currently under

  4. Mechanism of Oxidation of Brilliant Cresyl Blue with Acidic Chlorite ...

    African Journals Online (AJOL)

    diethylamino-8-methyl-phenoxazine chloride) (BB+) by chlorite in the presence of acid is reported. Under [H+]0>[ClO2–]0>[BB+]0 conditions, the oxidation reaction followed pseudo first-order kinetics with respect to BB+. During the reaction, chlorite ...

  5. Peroxisomal fatty acid beta-oxidation in relation to adrenoleukodystrophy

    NARCIS (Netherlands)

    Wanders, R. J.; Tager, J. M.

    1991-01-01

    X-linked adrenoleukodystrophy is a neurological disease characterized by progressive demyelination with destruction of the white matter, and adrenal insufficiency. Biochemically there is accumulation of very-long-chain fatty acids resulting from an impairment in the peroxisomal oxidation of these

  6. Formic Acid Oxidation at Platinum-Bismuth Clusters

    DEFF Research Database (Denmark)

    Lovic, J. D.; Stevanovic, S. I.; Tripkovic, D. V.

    2014-01-01

    Formic acid oxidation was studied on platinum-bismuth deposits on glassy carbon (GC) substrate. The catalysts of equimolar ratio were prepared by potentiostatic deposition using chronocoulometry. Bimetallic structures obtained by two-step process, comprising deposition of Bi followed by deposition...

  7. Fatty acids, lipid and protein oxidation, metmyoglobin reducing ...

    African Journals Online (AJOL)

    user

    2016-05-23

    May 23, 2016 ... ISSN 0375-1589 (print), ISSN 2221-4062 (online). Publisher: South African Society for Animal Science http://dx.doi.org/10.4314/sajas.v46i2.4. Fatty acids, lipid and protein oxidation, metmyoglobin reducing activity and sensory attributes of biceps femoris muscle in goats fed a canola and palm oil blend.

  8. Excessive fatty acid oxidation induces muscle atrophy in cancer cachexia.

    Science.gov (United States)

    Fukawa, Tomoya; Yan-Jiang, Benjamin Chua; Min-Wen, Jason Chua; Jun-Hao, Elwin Tan; Huang, Dan; Qian, Chao-Nan; Ong, Pauline; Li, Zhimei; Chen, Shuwen; Mak, Shi Ya; Lim, Wan Jun; Kanayama, Hiro-Omi; Mohan, Rosmin Elsa; Wang, Ruiqi Rachel; Lai, Jiunn Herng; Chua, Clarinda; Ong, Hock Soo; Tan, Ker-Kan; Ho, Ying Swan; Tan, Iain Beehuat; Teh, Bin Tean; Shyh-Chang, Ng

    2016-06-01

    Cachexia is a devastating muscle-wasting syndrome that occurs in patients who have chronic diseases. It is most commonly observed in individuals with advanced cancer, presenting in 80% of these patients, and it is one of the primary causes of morbidity and mortality associated with cancer. Additionally, although many people with cachexia show hypermetabolism, the causative role of metabolism in muscle atrophy has been unclear. To understand the molecular basis of cachexia-associated muscle atrophy, it is necessary to develop accurate models of the condition. By using transcriptomics and cytokine profiling of human muscle stem cell-based models and human cancer-induced cachexia models in mice, we found that cachectic cancer cells secreted many inflammatory factors that rapidly led to high levels of fatty acid metabolism and to the activation of a p38 stress-response signature in skeletal muscles, before manifestation of cachectic muscle atrophy occurred. Metabolomics profiling revealed that factors secreted by cachectic cancer cells rapidly induce excessive fatty acid oxidation in human myotubes, which leads to oxidative stress, p38 activation and impaired muscle growth. Pharmacological blockade of fatty acid oxidation not only rescued human myotubes, but also improved muscle mass and body weight in cancer cachexia models in vivo. Therefore, fatty acid-induced oxidative stress could be targeted to prevent cancer-induced cachexia.

  9. Fatty acid composition and oxidative stability of lambs' meat as ...

    African Journals Online (AJOL)

    Fatty acid composition and oxidative stability of lambs' meat as affected by a bioflavonoid antioxidant and fat sources. ... (EE) per kg dry matter (DM), differing in fat source (30 g/kg of either saturated beef tallow or unsaturated soybean oil) and type of antioxidant included (125 g/t of either a synthetic or natural antioxidant).

  10. Abnormal clearance of exogenous acid and increased acid sensitivity of the proximal duodenum in dyspeptic patients

    NARCIS (Netherlands)

    Samsom, M.; Verhagen, M. A.; vanBerge Henegouwen, G. P.; Smout, A. J.

    1999-01-01

    BACKGROUND & AIMS: Although acid is likely to play a role in the genesis of symptoms in dyspeptic patients, most studies have failed to show an increase in gastric acid secretion. The aim of this study was to investigate clearance of acid from the duodenum and its relationship with symptoms in

  11. Chloramines and hypochlorous acid oxidize erythrocyte peroxiredoxin 2.

    Science.gov (United States)

    Stacey, Melissa M; Peskin, Alexander V; Vissers, Margreet C; Winterbourn, Christine C

    2009-11-15

    Peroxiredoxin 2 (Prx2) is an abundant thiol protein that is readily oxidized in erythrocytes exposed to hydrogen peroxide. We investigated its reactivity in human erythrocytes with hypochlorous acid (HOCl) and chloramines, relevant oxidants in inflammation. Prx2 was oxidized to a disulfide-linked dimer by HOCl, glycine chloramine (GlyCl), and monochloramine (NH(2)Cl) in a dose-dependent manner. In the absence of added glucose, Prx2 and GSH showed similar sensitivities. Second-order rate constants for the reactions of Prx2 with NH(2)Cl and GlyCl were 1.5 x 10(4) and 8 M(-1) s(-1), respectively. The NH(2)Cl value is approximately 10 times higher than that for GSH, whereas Prx2 is approximately 30 times less sensitive than GSH to GlyCl. Thus, the relative sensitivity of Prx2 to GlyCl is greater in the erythrocyte. Oxidation of erythrocyte Prx2 and GSH was less in the presence of glucose, probably because of recycling. High doses of NH(2)Cl resulted in incomplete regeneration of reduced Prx2, suggesting impairment of the recycling mechanism. Our results show that, although HOCl and chloramines are less selective than H(2)O(2), they nevertheless oxidize Prx2. Exposure to these inflammatory oxidants will result in Prx2 oxidation and could compromise the erythrocyte's ability to resist damaging oxidative insult.

  12. Wheat aleurone polyphenols increase plasma eicosapentaenoic acid in rats

    Directory of Open Access Journals (Sweden)

    Fayçal Ounnas

    2014-08-01

    Full Text Available Methods: These studies were designed to assess whether wheat polyphenols (mainly ferulic acid [FA] increased the very-long-chain omega-3 fatty acids (VLC n-3 [eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA] in rats. Wheat aleurone (WA was used as a dietary source of wheat polyphenols. Two experiments were performed; in the first one, the rats were fed WA or control pellets (CP in presence of linseed oil (LO to provide alpha-linolenic acid (ALA, the precursor of VLC n-3. In the second one, the rats were fed WA or CP in presence of control oil (CO without ALA. The concentrations of phenolic acid metabolites in urine were also investigated. Results: The urinary concentration of conjugated FA increased with WA ingestion (p<0.05. Plasma EPA increased by 25% (p<0.05 with WA in the CO group but not in the LO group. In contrast, there was no effect of WA on plasma DHA and omega-6 fatty acids (n-6. Finally, both n-3 and n-6 in the liver remained unchanged by the WA. Conclusion: These results suggest that WA consumption has a significant effect on EPA in plasma without affecting n-6. Subsequent studies are required to examine whether these effects may explain partly the health benefits associated with whole wheat consumption.

  13. Ophthalmic acid is a marker of oxidative stress in plants as in animals.

    Science.gov (United States)

    Servillo, Luigi; Castaldo, Domenico; Giovane, Alfonso; Casale, Rosario; D'Onofrio, Nunzia; Cautela, Domenico; Balestrieri, Maria Luisa

    2018-04-01

    Ophthalmic acid (OPH), γ-glutamyl-L-2-aminobutyryl-glycine, a tripeptide analogue of glutathione (GSH), has recently captured considerable attention as a biomarker of oxidative stress in animals. The OPH and GSH biosynthesis, as well as some biochemical behaviors, are very similar. Here, we sought to investigate the presence of OPH in plants and its possible relationship with GSH, known to possess multiple functions in the plant development, growth and response to environmental changes. HPLC-ESI-MS/MS analysis was used to examine the occurrence of OPH in leaves from various plant species, and flours from several plant seeds. Different types of oxidative stress, i.e., water, dark, paraquat, and cadmium stress, were induced in rye, barley, oat, and winter wheat leaves to evaluate the effects on the levels of OPH and its metabolic precursors. OPH and its dipeptide precursor, γ-glutamyl-2-aminobutyric acid, were found to occur in phylogenetically distant plants. Interestingly, the levels of OPH were tightly associated with the oxidative stress tested. Levels of OPH precursors, γ-glutamyl-2-aminobutyric acid and 2-aminobutyric acid, the latter efficiently formed in plants via biosynthetic pathways absent in the animal kingdom, were also found to increase during oxidative stress. OPH occurs in plants and its levels are tightly associated with oxidative stress. OPH behaves as an oxidative stress marker and its biogenesis might occur through a biochemical pathway common to many living organisms. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Green reduction of graphene oxide by ascorbic acid

    Science.gov (United States)

    Khosroshahi, Zahra; Kharaziha, Mahshid; Karimzadeh, Fathallah; Allafchian, Alireza

    2018-01-01

    Graphene, a single layer of sp2-hybridized carbon atoms in a hexagonal (two-dimensional honey-comb) lattice, has attracted strong scientific and technological interest due to its novel and excellent optical, chemical, electrical, mechanical and thermal properties. The solution-processable chemical reduction of Graphene oxide (GO is considered as the most favorable method regarding mass production of graphene. Generally, the reduction of GO is carried out by chemical approaches using different reductants such as hydrazine and sodium borohydride. These components are corrosive, combustible and highly toxic which may be dangerous for personnel health and the environment. Hence, these reducing agents are not promising choice for reducing of graphene oxide (GO). As a consequence, it is necessary for further development and optimization of eco-friendly, natural reducing agent for clean and effective reduction of GO. Ascorbic acid, an eco-friendly and natural reducing agents, having a mild reductive ability and nontoxic property. So, the aim of this research was to green synthesis of GO with ascorbic acid. For this purpose, the required amount of NaOH and ascorbic acid were added to GO solution (0.5 mg/ml) and were heated at 95 °C for 1 hour. According to the X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and electrochemical results, GO were reduced with ascorbic acid like hydrazine with better electrochemical properties and ascorbic acid is an ideal substitute for hydrazine in the reduction of graphene oxide process.

  15. Effect of testosterone on oxidative stress and cell damage induced by 3-nitropropionic acid in striatum of ovariectomized rats.

    Science.gov (United States)

    Túnez, Isaac; Feijóo, Montserrat; Collado, Juan A; Medina, Francisco J; Peña, José; Muñoz, María del C; Jimena, Ignacio; Franco, Francisco; Rueda, Ignacio; Muntané, Jordi; Montilla, Pedro

    2007-03-06

    This paper evaluates the effects of testosterone (0.5 mg/kg subcutaneously (s.c.) for 8 days) on oxidative stress and cell damage induced by 3-nitropropionic acid (20 mg/kg intraperitoneally (i.p.) for 4 days) in ovariectomized rats. Gonadectomy triggered oxidative damage and cell loss, evaluated by the detection of caspase-3, whereas 3-nitropropionic acid increased the levels of oxidative stress induced by ovariectomy and prompted cell damage characterized by enhanced levels of lactate dehydrogenase. These changes were blocked by testosterone administration. Our results support the following conclusions: i) ovariectomy triggers oxidative and cell damage via caspase-3 in the striatum; ii) 3-nitropropionic acid exacerbates oxidative stress induced by ovariectomy and leads to cell damage characterized by increased levels of lactate dehydrogenase; iii) testosterone administration decreases oxidative stress and cell damage. Additionally, these data support the hypothesis that testosterone might play an important role in the onset and development of neurodegenerative diseases.

  16. Ascorbate and dehydroascorbic acid as reliable biomarkers of oxidative stress

    DEFF Research Database (Denmark)

    Lykkesfeldt, Jens

    2007-01-01

    Lack of post-sampling stability of ascorbate and dehydroascorbic acid and failure to block their in vivo equilibrium have lowered their value as biomarkers of oxidative stress and limited the ability to further investigate their possible role in disease prevention. In the present paper......, the analytical reproducibility was tested by repeated analysis of plasma aliquots from one individual over four years. The plasma was subjected to acidic deproteinization with an equal volume of 10% meta-phosphoric acid containing 2 mM EDTA and analyzed for ascorbate and dehydroascorbic acid by high......-performance liquid chromatography with coulometric detection. In a parallel experiment, stability of human plasma samples treated as above and stored at -80°C for five years was tested in a cohort of 131 individuals. No degradation or shift in the equilibrium between ascorbate and dehydroascorbic acid was observed...

  17. Increased oxidative stress in obesity: implications for metabolic syndrome, diabetes, hypertension, dyslipidemia, atherosclerosis, and cancer.

    Science.gov (United States)

    Matsuda, Morihiro; Shimomura, Iichiro

    2013-01-01

    Obesity, especially of the abdominal type, is a health problem that constitutes metabolic syndrome and increases the incidence of various diseases, including diabetes, hypertension, dyslipidemia, atherosclerosis, and cancer. Various mechanisms linking obesity to these associated diseases have been postulated. One candidate is oxidative stress, which has been implicated in vascular complications of diabetes and in pancreatic -cell failure in diabetes. Notably, obese people without diabetes also display elevated levels of systemic oxidative stress. In addition, levels of oxidative stress are increased in the adipose tissue in obese mice. Treating obese mice with antioxidant agents attenuates the development of diabetes. In 3T3-L1 adipocytes, increases in reactive oxygen species (ROS) occur with lipid accumulation; the addition of free fatty acids elevates ROS generation further. Thus, adipose tissue represents an important source of ROS; ROS may contribute to the development of obesity-associated insulin resistance and type 2 diabetes. Moreover, the levels of oxidative stress present in several other types of cells or tis-sues, including those in the brain, arterial walls, and tumors, have been implicated in the pathogenesis associated with hypertension, atherosclerosis, and cancer. The increased levels of systemic oxidative stress that occur in obesity may contribute to the obesity-associated development of these diseases. © 2013 Asian Oceanian Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.

  18. Citric acid effects on brain and liver oxidative stress in lipopolysaccharide-treated mice.

    Science.gov (United States)

    Abdel-Salam, Omar M E; Youness, Eman R; Mohammed, Nadia A; Morsy, Safaa M Youssef; Omara, Enayat A; Sleem, Amany A

    2014-05-01

    Citric acid is a weak organic acid found in the greatest amounts in citrus fruits. This study examined the effect of citric acid on endotoxin-induced oxidative stress of the brain and liver. Mice were challenged with a single intraperitoneal dose of lipopolysaccharide (LPS; 200 μg/kg). Citric acid was given orally at 1, 2, or 4 g/kg at time of endotoxin injection and mice were euthanized 4 h later. LPS induced oxidative stress in the brain and liver tissue, resulting in marked increase in lipid peroxidation (malondialdehyde [MDA]) and nitrite, while significantly decreasing reduced glutathione, glutathione peroxidase (GPx), and paraoxonase 1 (PON1) activity. Tumor necrosis factor-alpha (TNF-α) showed a pronounced increase in brain tissue after endotoxin injection. The administration of citric acid (1-2 g/kg) attenuated LPS-induced elevations in brain MDA, nitrite, TNF-α, GPx, and PON1 activity. In the liver, nitrite was decreased by 1 g/kg citric acid. GPx activity was increased, while PON1 activity was decreased by citric acid. The LPS-induced liver injury, DNA fragmentation, serum transaminase elevations, caspase-3, and inducible nitric oxide synthase expression were attenuated by 1-2 g/kg citric acid. DNA fragmentation, however, increased after 4 g/kg citric acid. Thus in this model of systemic inflammation, citric acid (1-2 g/kg) decreased brain lipid peroxidation and inflammation, liver damage, and DNA fragmentation.

  19. An Increase in the Omega-6/Omega-3 Fatty Acid Ratio Increases the Risk for Obesity

    OpenAIRE

    Artemis P. Simopoulos

    2016-01-01

    In the past three decades, total fat and saturated fat intake as a percentage of total calories has continuously decreased in Western diets, while the intake of omega-6 fatty acid increased and the omega-3 fatty acid decreased, resulting in a large increase in the omega-6/omega-3 ratio from 1:1 during evolution to 20:1 today or even higher. This change in the composition of fatty acids parallels a significant increase in the prevalence of overweight and obesity. Experimental studies have sugg...

  20. Heterogeneous Reactions of Acetic Acid with Oxide Surfaces: Effects of Mineralogy and Relative Humidity.

    Science.gov (United States)

    Tang, Mingjin; Larish, Whitney A; Fang, Yuan; Gankanda, Aruni; Grassian, Vicki H

    2016-07-21

    We have investigated the heterogeneous uptake of gaseous acetic acid on different oxides including γ-Al2O3, SiO2, and CaO under a range of relative humidity conditions. Under dry conditions, the uptake of acetic acid leads to the formation of both acetate and molecularly adsorbed acetic acid on γ-Al2O3 and CaO and only molecularly adsorbed acetic acid on SiO2. More importantly, under the conditions of this study, dimers are the major form for molecularly adsorbed acetic acid on all three particle surfaces investigated, even at low acetic acid pressures under which monomers are the dominant species in the gas phase. We have also determined saturation surface coverages for acetic acid adsorption on these three oxides under dry conditions as well as Langmuir adsorption constants in some cases. Kinetic analysis shows that the reaction rate of acetic acid increases by a factor of 3-5 for γ-Al2O3 when relative humidity increases from 0% to 15%, whereas for SiO2 particles, acetic acid and water are found to compete for surface adsorption sites.

  1. Uric acid increases erythrocyte aggregation: Implications for cardiovascular disease.

    Science.gov (United States)

    Sloop, Gregory D; Bialczak, Jessica K; Weidman, Joseph J; St Cyr, J A

    2016-10-05

    Uric acid may be a risk factor for atherosclerotic cardiovascular disease, although the data conflict and the mechanism by which it may cause cardiovascular disease is uncertain. This study was performed to test the hypothesis that uric acid, an anion at physiologic pH, can cause erythrocyte aggregation, which itself is associated with cardiovascular disease. Normal erythrocytes and erythrocytes with a positive direct antiglobulin test for surface IgG were incubated for 15 minutes in 14.8 mg/dL uric acid. Erythrocytes without added uric acid were used as controls. Erythrocytes were then examined microscopically for aggregation. Aggregates of up to 30 erythrocytes were noted when normal erythrocytes were incubated in uric acid. Larger aggregates were noted when erythrocytes with surface IgG were incubated in uric acid. Aggregation was negligible in controls. These data show that uric acid causes erythrocyte aggregation. The most likely mechanism is decreased erythrocyte zeta potential. Erythrocyte aggregates will increase blood viscosity at low shear rates and increase the risk of atherothrombosis. In this manner, hyperuricemia and decreased zeta potential may be risk factors for atherosclerotic cardiovascular disease.

  2. Survival of the Fittest: Overcoming Oxidative Stress at the Extremes of Acid, Heat and Metal

    Directory of Open Access Journals (Sweden)

    Yukari Maezato

    2012-08-01

    Full Text Available The habitat of metal respiring acidothermophilic lithoautotrophs is perhaps the most oxidizing environment yet identified. Geothermal heat, sulfuric acid and transition metals contribute both individually and synergistically under aerobic conditions to create this niche. Sulfuric acid and metals originating from sulfidic ores catalyze oxidative reactions attacking microbial cell surfaces including lipids, proteins and glycosyl groups. Sulfuric acid also promotes hydrocarbon dehydration contributing to the formation of black “burnt” carbon. Oxidative reactions leading to abstraction of electrons is further impacted by heat through an increase in the proportion of reactant molecules with sufficient energy to react. Collectively these factors and particularly those related to metals must be overcome by thermoacidophilic lithoautotrophs in order for them to survive and proliferate. The necessary mechanisms to achieve this goal are largely unknown however mechanistics insights have been gained through genomic studies. This review focuses on the specific role of metals in this extreme environment with an emphasis on resistance mechanisms in Archaea.

  3. Uric acid and allantoin levels in Down syndrome: antioxidant and oxidative stress mechanisms?

    Science.gov (United States)

    Zitnanová, Ingrid; Korytár, Peter; Aruoma, Okezie I; Sustrová, Mária; Garaiová, Iveta; Muchová, Jana; Kalnovicová, Terézia; Pueschel, Siegfried; Duracková, Zdenka

    2004-03-01

    Down syndrome (DS) is a chromosomal abnormality (trisomy 21) leading to mental retardation, to the characteristic change of individual's phenotype and to the pathological features of Alzheimer disease. Patients with DS have elevated ratio of superoxide dismutase to (catalase plus glutathione peroxidase) with respect to controls in all age categories suggesting that oxidative imbalance contributes to the clinical manifestation of accelerated aging. We report that persons with DS have elevated uric acid levels compared with controls, 348.56+/-22.78 versus 284.00+/-20.86 micromol/l (p=0.018). The levels of hypoxanthine and xanthine in DS children (6.35+/-0.31 and 1.02+/-0.23 micromol/l) were significantly lower than in controls (7.83+/-0.59 and 2.43+/-0.66 micromol/l). This result suggests increased conversion of hypoxanthine and xanthine to uric acid with subsequent free radical-dependent oxidation of uric acid to allantoin, mechanisms potentiated by the oxidative stress in DS. Allantoin is a nonenzymatic oxidative product of uric acid in human. In DS individuals, the levels of allantoin were significantly higher than those in healthy controls (18.58+/-2.27 and 14.07+/-1.07 micromol/l, respectively, p=0.03). Our data supported the presumption of increased oxidative stress in DS.

  4. The interplay between acid-base and free radical chemistry in the heterogeneous oxidation and fragmentation of citric acid in aqueous aerosol by OH radicals

    Science.gov (United States)

    Liu, M.; Wiegel, A. A.; Wilson, K. R.; Houle, F. A.

    2016-12-01

    A key uncertainty in the oxidation of organic compounds such as carboxylic acids in aqueous phase aerosol is how β-scission of alkoxy radicals is altered by acid-base chemistry. In particular, the differences between the unimolecular fragmentation rates of radical anions and their neutral forms may impact the partitioning of organic carbon between the gas and aqueous phase. To investigate the fragmentation reactions that occur during the oxidation of highly oxygenated organic aqueous aerosol, a kinetics model is developed for the OH initiated oxidation of citric acid aerosol at high relative humidities. The reaction scheme includes both free radical and acid-base reactions, uses physically validated rate coefficients, and thus accurately predicts the experimentally observed molecular composition, particle size, and average elemental composition of the aerosol upon oxidation. Free radical reactions functionalize the carbon skeleton while carboxylate groups from acid-base chemistry activate the carbon-carbon bond fragmentation of alkoxy radicals, leading to the formation of low molecular weight, highly oxidized products such as oxaloacetic and mesoxalic acid. Subsequent hydration of carbonyl groups in the oxidized products increases the aerosol hygroscopicity and causes the substantial water uptake and volume growth observed to accompany oxidation. These results highlight the significant role of water in controlling not only changes in physical properties but also the mechanisms of oxidation and fragmentation of aerosol in the atmosphere.

  5. Free fatty acids increase hepatic glycogen content in obese males

    NARCIS (Netherlands)

    Allick, G.; Sprangers, F.; Weverling, G. J.; Ackermans, M. T.; Meijer, A. J.; Romijn, J. A.; Endert, E.; Bisschop, P. H.; Sauerwein, H. P.

    2004-01-01

    Obesity is associated with increased hepatic glycogen content. In vivo and in vitro data suggest that plasma free fatty acids (FFA) may cause this increase. In this study we investigated the effect of physiological plasma FFA levels on hepatic glycogen metabolism by studying intrahepatic glucose

  6. Oxidized low density lipoprotein increases RANKL level in human vascular cells. Involvement of oxidative stress

    Energy Technology Data Exchange (ETDEWEB)

    Mazière, Cécile, E-mail: maziere.cecile@chu-amiens.fr [Biochemistry Laboratory, South Hospital University, René Laennec Avenue, Amiens 80000 (France); Salle, Valéry [Internal Medicine, North Hospital University, Place Victor Pauchet, Amiens 80000 (France); INSERM U1088 (EA 4292), SFR CAP-Santé (FED 4231), University of Picardie – Jules Verne (France); Gomila, Cathy; Mazière, Jean-Claude [Biochemistry Laboratory, South Hospital University, René Laennec Avenue, Amiens 80000 (France)

    2013-10-18

    Highlights: •Oxidized LDL enhances RANKL level in human smooth muscle cells. •The effect of OxLDL is mediated by the transcription factor NFAT. •UVA, H{sub 2}O{sub 2} and buthionine sulfoximine also increase RANKL level. •All these effects are observed in human fibroblasts and endothelial cells. -- Abstract: Receptor Activator of NFκB Ligand (RANKL) and its decoy receptor osteoprotegerin (OPG) have been shown to play a role not only in bone remodeling but also in inflammation, arterial calcification and atherosclerotic plaque rupture. In human smooth muscle cells, Cu{sup 2+}-oxidized LDL (CuLDL) 10–50 μg/ml increased reactive oxygen species (ROS) and RANKL level in a dose-dependent manner, whereas OPG level was not affected. The lipid extract of CuLDL reproduced the effects of the whole particle. Vivit, an inhibitor of the transcription factor NFAT, reduced the CuLDL-induced increase in RANKL, whereas PKA and NFκB inhibitors were ineffective. LDL oxidized by myeloperoxidase (MPO-LDL), or other pro-oxidant conditions such as ultraviolet A (UVA) irradiation, incubation with H{sub 2}O{sub 2} or with buthionine sulfoximine (BSO), an inhibitor of glutathione synthesis{sub ,} also induced an oxidative stress and enhanced RANKL level. The increase in RANKL in pro-oxidant conditions was also observed in fibroblasts and endothelial cells. Since RANKL is involved in myocardial inflammation, vascular calcification and plaque rupture, this study highlights a new mechanism whereby OxLDL might, by generation of an oxidative stress, exert a deleterious effect on different cell types of the arterial wall.

  7. Fructose and Sucrose Intake Increase Exogenous Carbohydrate Oxidation during Exercise

    Science.gov (United States)

    Trommelen, Jorn; Fuchs, Cas J.; Beelen, Milou; Lenaerts, Kaatje; Jeukendrup, Asker E.; Cermak, Naomi M.; van Loon, Luc J. C.

    2017-01-01

    Peak exogenous carbohydrate oxidation rates typically reach ~1 g·min−1 during exercise when ample glucose or glucose polymers are ingested. Fructose co-ingestion has been shown to further increase exogenous carbohydrate oxidation rates. The purpose of this study was to assess the impact of fructose co-ingestion provided either as a monosaccharide or as part of the disaccharide sucrose on exogenous carbohydrate oxidation rates during prolonged exercise in trained cyclists. Ten trained male cyclists (VO2peak: 65 ± 2 mL·kg−1·min−1) cycled on four different occasions for 180 min at 50% Wmax during which they consumed a carbohydrate solution providing 1.8 g·min−1 of glucose (GLU), 1.2 g·min−1 glucose + 0.6 g·min−1 fructose (GLU + FRU), 0.6 g·min−1 glucose + 1.2 g·min−1 sucrose (GLU + SUC), or water (WAT). Peak exogenous carbohydrate oxidation rates did not differ between GLU + FRU and GLU + SUC (1.40 ± 0.06 vs. 1.29 ± 0.07 g·min−1, respectively, p = 0.999), but were 46% ± 8% higher when compared to GLU (0.96 ± 0.06 g·min−1: p < 0.05). In line, exogenous carbohydrate oxidation rates during the latter 120 min of exercise were 46% ± 8% higher in GLU + FRU or GLU + SUC compared with GLU (1.19 ± 0.12, 1.13 ± 0.21, and 0.82 ± 0.16 g·min−1, respectively, p < 0.05). We conclude that fructose co-ingestion (0.6 g·min−1) with glucose (1.2 g·min−1) provided either as a monosaccharide or as sucrose strongly increases exogenous carbohydrate oxidation rates during prolonged exercise in trained cyclists. PMID:28230742

  8. Free fatty acids enhance the oxidative damage induced by ethanol metabolism in an in vitro model.

    Science.gov (United States)

    Hernández, Ileana; Domínguez-Pérez, Mayra; Bucio, Leticia; Souza, Verónica; Miranda, Roxana U; Clemens, Dahn L; Gomez-Quiroz, Luis Enrique; Gutiérrez-Ruiz, María Concepción

    2015-02-01

    In recent years, there has been a growing interest to explore the responsiveness to injury in steatotic hepatocyte. VL-17A cells, which express ADH and Cyp2E1 overloaded with free fatty acids (1 mM of oleic and palmitic acid 2:1) showed an increased oxidative damaged after 24 h free fatty acids treatment when exposed to ethanol (100 mM) for 48 h as a second injury. An increment in reactive oxygen species, determined by DCFH-DA, protein oxidation, and apoptosis were observed although an increase in main antioxidant proteins such as superoxide dismutase 1 and glutathione peroxidase were observed, but failed in gamma-glutamylcysteine synthetase, suggesting a decreased capacity of synthesis of glutathione compared with cells treated only with free fatty acids or ethanol. The increased oxidative stress and toxicity in lipid overloaded VL-17A cells subjected to ethanol exposure were accompanied by increases in Cyp2E1 protein expression. Our data show that lipid loaded in an in vitro model, VL-17A cells, is more susceptible to cell damage and oxidative stress when treated with ethanol. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Hepatic Fatty Acid Oxidation Restrains Systemic Catabolism during Starvation

    Directory of Open Access Journals (Sweden)

    Jieun Lee

    2016-06-01

    Full Text Available The liver is critical for maintaining systemic energy balance during starvation. To understand the role of hepatic fatty acid β-oxidation on this process, we generated mice with a liver-specific knockout of carnitine palmitoyltransferase 2 (Cpt2L−/−, an obligate step in mitochondrial long-chain fatty acid β-oxidation. Fasting induced hepatic steatosis and serum dyslipidemia with an absence of circulating ketones, while blood glucose remained normal. Systemic energy homeostasis was largely maintained in fasting Cpt2L−/− mice by adaptations in hepatic and systemic oxidative gene expression mediated in part by Pparα target genes including procatabolic hepatokines Fgf21, Gdf15, and Igfbp1. Feeding a ketogenic diet to Cpt2L−/− mice resulted in severe hepatomegaly, liver damage, and death with a complete absence of adipose triglyceride stores. These data show that hepatic fatty acid oxidation is not required for survival during acute food deprivation but essential for constraining adipocyte lipolysis and regulating systemic catabolism when glucose is limiting.

  10. Clarithromycin, trimethoprim, and penicillin and oxidative nucleic acid modifications in humans: randomised, controlled trials.

    Science.gov (United States)

    Larsen, Emil List; Cejvanovic, Vanja; Kjaer, Laura Kofoed; Pedersen, Morten Thorup; Popik, Sara Daugaard; Hansen, Lina Kallehave; Andersen, Jon Traerup; Jimenez-Solem, Espen; Broedbaek, Kasper; Petersen, Morten; Weimann, Allan; Henriksen, Trine; Lykkesfeldt, Jens; Torp-Pedersen, Christian; Poulsen, Henrik Enghusen

    2017-08-01

    In vitro studies have demonstrated that formation of reactive oxygen species (ROS) contributes to the effect of bactericidal antibiotics. The formation of ROS is not restricted to bacteria, but also occurs in mammalian cells. Oxidative stress is linked to several diseases. This study investigates whether antibiotic drugs induce oxidative stress in healthy humans as a possible mechanism for adverse reactions to the antibiotic drugs. This study contains information from two randomised, controlled trials. Participants underwent 1 week treatment with clarithromycin, trimethoprim, phenoxymethylpenicillin (penicillin V), or placebo. Oxidative modifications were measured as 24-h urinary excretion of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydroguanosine (8-oxoGuo), and plasma levels of malondialdehyde before and after treatment as a measurement of DNA oxidation, RNA oxidation, and lipid peroxidation, respectively. Clarithromycin significantly increased urinary excretion of 8-oxodG by 22.0% (95% confidence interval (CI): 3.6-40.4%) and 8-oxoGuo by 14.9% (95% CI: 3.7-26.1%). Further, we demonstrated that trimethoprim significantly lowered urinary excretion of 8-oxodG by 21.7% (95% CI: 5.8-37.6%), but did not influence urinary excretion of 8-oxoGuo. Penicillin V did not influence urinary excretion of 8-oxodG or 8-oxoGuo. None of the antibiotic drugs influenced plasma levels of malondialdehyde. Clarithromycin significantly increases oxidative nucleic acid modifications. Increased oxidative modifications might explain some of clarithromycin's known adverse reactions. Trimethoprim significantly lowers DNA oxidation but not RNA oxidation. Penicillin V had no effect on oxidative nucleic acid modifications. © 2017 The British Pharmacological Society.

  11. Normal mitochondrial function and increased fat oxidation capacity in leg and arm muscles in obese humans

    DEFF Research Database (Denmark)

    Ara, I; Larsen, S; Stallknecht, Bente Merete

    2011-01-01

    Aim/hypothesis:The aim of this study was to investigate mitochondrial function, fibre-type distribution and substrate oxidation during exercise in arm and leg muscles in male postobese (PO), obese (O) and age- and body mass index (BMI)-matched control (C) subjects. The hypothesis of the study...... deltoideus (m. deltoideus) and m. vastus lateralis muscles. Fibre-type composition, enzyme activity and O(2) flux capacity of saponin-permeabilized muscle fibres were measured, the latter by high-resolution respirometry.Results:During the graded exercise tests, peak fat oxidation during leg cycling......, and plasma leptin was higher in O than in PO and C.Conclusions:In O subjects, maximal fat oxidation during exercise and the eliciting relative exercise intensity are increased. This is associated with higher intramuscular triglyceride levels and higher resting non esterified fatty acid (NEFA) concentrations...

  12. Absence of systemic oxidative stress and increased CSF prostaglandin F2α in progressive MS

    DEFF Research Database (Denmark)

    Lam, Magda A.; Maghzal, Ghassan J.; Khademi, Mohsen

    2016-01-01

    Objective: We aimed to investigate the role of oxidative stress in the progression of multiple sclerosis (MS).  Methods: We determined by liquid chromatography-tandem mass spectrometry nonenzymatic (F2-isoprostanes) and enzymatic oxidation products of arachidonic acid (prostaglandin F2α [PGF2α......]) in plasma and CSF of 45 controls (other neurologic disease [OND] with no signs of inflammation) and 62 patients with MS. Oxidation products were correlated with disease severity and validated biomarkers of inflammation (chemokine ligand 13; matrix metalloproteinase-9; osteopontin) and axonal damage......, but not F2-isoprostanes, were significantly higher in patients with progressive disease than OND controls (p age (p = 0.022), although this increase could not be explained by age. CSF PGF2α decreased...

  13. Formic acid oxidation at platinum-bismuth catalysts

    Directory of Open Access Journals (Sweden)

    Popović Ksenija Đ.

    2015-01-01

    Full Text Available The field of heterogeneous catalysis, specifically catalysis on bimetallic surfaces, has seen many advances over the past few decades. Bimetallic catalysts, which often show electronic and chemical properties that are distinct from those of their parent metals, offer the opportunity to obtain new catalysts with enhanced selectivity, activity, and stability. The oxidation of formic acid is of permanent interest as a model reaction for the mechanistic understanding of the electrooxidation of small organic molecules and because of its technical relevance for fuel cell applications. Platinum is one of the most commonly used catalysts for this reaction, despite the fact that it shows a few significant disadvantages: high cost and extreme susceptibility to poisoning by CO. To solve this problem, several approaches have been used, but generally, they all consist in the modification of platinum with a second element. Especially, bismuth has received significant attention as Pt modifier. According to the results presented in this survey dealing with the effects influencing the formic acid oxidation it was found that two types of Pt-Bi bimetallic catalysts (bulk and low loading deposits on GC showed superior catalytic activity in terms of the lower onset potential and oxidation current density, as well as exceptional stability compared to Pt. The findings in this report are important for the understanding of mechanism of formic acid electrooxidation on a bulk alloy and decorated surface, for the development of advanced anode catalysts for direct formic acid fuel cells, as well as for the synthesis of novel low-loading bimetallic catalysts. The use of bimetallic compounds as the anode catalysts is an effective solution to overcoming the problems of the formic acid oxidation current stability for long term applications. In the future, the tolerance of both CO poisoning and electrochemical leaching should be considered as the key factors in the development

  14. Effects of Dietary Zinc Oxide and a Blend of Organic Acids on Broiler Live Performance, Carcass Traits, and Serum Parameters

    Directory of Open Access Journals (Sweden)

    BG Sarvari

    2015-12-01

    Full Text Available ABSTRACT This experiment was carried out to evaluate the effect of different dietary supplementation levels of zinc oxide and of an organic acid blend on broiler performance, carcass traits, and serum parameters. A total of 2400 one-day-old male Ross 308 broiler chicks, with average initial body weight 44.21±0.19g, was distributed according to a completely randomized design in a 2 x 3 factorial arrangement. Six treatments, consisting of diets containing two zinc oxide levels (0 and 0.01% of the diet and three organic acid blend levels (0, 0.15, and 0.30% were applied, with eight replicates of 50 birds each. The experimental diets were supplied ad libitum for 42 days. There were significant performance differences among birds fed the different zinc oxide and organic acid blend levels until 42 d of age (p<0.01. The result of this experiment showed that the organic acid blend did not affect feed intake, but zinc oxide increased feed intake. Carcass traits were not influenced by the experimental supplements. Zinc oxide supplementation increased serum alkaline phosphatase level (p<0.01. The organic acid blend reduced serum cholesterol and triglyceride levels (p<0.05. No interactions were found between zinc oxide and the organic acid blend for none of the evaluated parameters. We concluded that zinc oxide and the evaluated organic acid blend improve broiler performance.

  15. Oxidative stability of Liposomes composed of docosahexaenoic acid-containing phospholipids

    DEFF Research Database (Denmark)

    Vikbjerg, Anders Falk; Andresen, Thomas Lars; Jørgensen, Kent

    2007-01-01

    Oxidative stability of liposomes made of (Docosahexaenoic acid) DHA-containing phosphatidylcholine (PC) was examined during preparation and storage. After preparation of the liposomes, the concentration of primary (conjugated dienes) and secondary oxidation products (Thiobarbituric acid-reactive...

  16. Santonic acid: Zn-HCl-ether reduction and ceric ammonium nitrate oxidation.

    Science.gov (United States)

    Fondekar, Kamlesh Pai; Malik, Bhiwa; Paknikar, Shashikumar Keshav

    2014-01-01

    Reduction of santonic acid using Zn-HCl-ether yielded succinic anhydride derivatives via pinacolisation followed by rearrangement, whereas oxidation of santonic acid using ceric ammonium nitrate afforded five oxidative decarboxylation products. Dedicated to Prof. TBH McMurry.

  17. Investigation of Influential Parameters in Deep Oxidative Desulfurization of Dibenzothiophene with Hydrogen Peroxide and Formic Acid

    Directory of Open Access Journals (Sweden)

    Alireza Haghighat Mamaghani

    2013-01-01

    Full Text Available An effective oxidative system consisting of hydrogen peroxide, formic acid, and sulfuric acid followed by an extractive stage were implemented to remove dibenzothiophene in the simulated fuel oil. The results revealed such a great performance in the case of H2O2 in the presence of formic and sulfuric acids that led to the removal of sulfur compounds. Sulfuric acid was employed to increase the acidity of media as well as catalytic activity together with formic acid. The oxidation reaction was followed by a liquid-liquid extraction stage using acetonitrile as a polar solvent to remove produced sulfones from the model fuel. The impact of operating parameters including the molar ratio of formic acid to sulfur (, hydrogen peroxide to sulfur (, and the time of reaction was investigated using Box-Behnken experimental design for oxidation of the model fuel. A significant quadratic model was introduced for the sulfur removal as a function of effective parameters by the statistic analysis.

  18. Kinetics of inorganic arsenopyrite oxidation in acidic aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    McKibben, M.A.; Tallant, B.A.; del Angel, J.K. [University of California Riverside, Riverside, CA (United States). Dept. of Earth Science

    2008-02-15

    In an effort to help evaluate the significance of common primary As-bearing minerals in releasing As into surface and ground waters, experiments were performed to determine rate laws for the irreversible inorganic aqueous oxidation of arsenopyrite by dissolved O{sub 2}, Fe{sup 3+} and NO{sub 3}{sup -} in low temperature acidic solutions. Batch reactor run conditions varied from pH 2-4.5 and 10-40{sup o}C at ionic strength 0.01 M. A major constraint on defining and measuring the rate of arsenopyrite oxidation is the non-stoichiometry (incongruency) of the reaction in acidic solutions; As and S are not released completely into solution, apparently remaining behind as more slowly-dissolving solids in an Fe-depleted lattice. Therefore the rate of mineral oxidation (destruction) at low pH is best defined and measured by rates of change in total dissolved Fe concentrations, not by changes in dissolved As or S concentrations or Eh. The measured mineral dissolution rate therefore places an upper limit on actual inorganic As-release rates, providing a conservative basis for geochemical modeling that may over-predict, but not underestimate, As concentrations observed in natural settings. The results indicate that Fe{sup 3+} oxidizes arsenopyrite at least 10 times faster than dissolved O{sub 2}. Nitrate does not oxidize arsenopyrite. At low pH arsenopyrite oxidizes 3-4 orders of magnitude faster than (arsenical) pyrite and 4-5 orders of magnitude faster than realgar and orpiment. Therefore in rocks with low ratios of arsenopyrite to other As-bearing sulfides, including coals and ores, arsenopyrite oxidation can still be the dominant source of As-release from sulfide minerals.

  19. Amino Acid and Peptide Immobilization on Oxidized Nanocellulose: Spectroscopic Characterization

    Directory of Open Access Journals (Sweden)

    Claude Daneault

    2012-06-01

    Full Text Available In this work, oxidized nanocellulose (ONC was synthesized and chemically coupled with amino acids and peptides using a two step coupling method at room temperature. First, ONC was activated by N-ethyl-N’-(3-dimethylaminopropyl carbodiimide hydrochloride, forming a stable active ester in the presence of N-hydroxysuccinimide. Second, the active ester was reacted with the amino group of the amino acid or peptide, forming an amide bond between ONC and the grafted molecule. Using this method, the intermolecular interaction of amino acids and peptides was avoided and uniform coupling of these molecules on ONC was achieved. The coupling reaction was very fast in mild conditions and without alteration of the polysaccharide. The coupling products (ONC-amino acids and ONC-peptides were characterized by transmission electron microscopy and by the absorption, emission, Fourier transform infrared spectroscopy (FTIR and X-ray photoelectron spectroscopy (XPS spectroscopic techniques.

  20. Conjugated linoleic acid or omega 3 fatty acids increase mitochondrial biosynthesis and metabolism in skeletal muscle cells

    Directory of Open Access Journals (Sweden)

    Vaughan Roger A

    2012-10-01

    Full Text Available Abstract Background Polyunsaturated fatty acids are popular dietary supplements advertised to contribute to weight loss by increasing fat metabolism in liver, but the effects on overall muscle metabolism are less established. We evaluated the effects of conjugated linoleic acid (CLA or combination omega 3 on metabolic characteristics in muscle cells. Methods Human rhabdomyosarcoma cells were treated with either DMSO control, or CLA or combination omega 3 for 24 or 48 hours. RNA was determined using quantitative reverse transcriptase polymerase chain reaction (qRT-PCR. Mitochondrial content was determined using flow cytometry and immunohistochemistry. Metabolism was quantified by measuring extracellular acidification and oxygen consumption rates. Results Omega 3 significantly induced metabolic genes as well as oxidative metabolism (oxygen consumption, glycolytic capacity (extracellular acidification, and metabolic rate compared with control. Both treatments significantly increased mitochondrial content. Conclusion Omega 3 fatty acids appear to enhance glycolytic, oxidative, and total metabolism. Moreover, both omega 3 and CLA treatment significantly increase mitochondrial content compared with control.

  1. Amorphous palladium-silicon alloys for the oxidation of formic acid and formaldehyde. A voltammetric investigation

    Directory of Open Access Journals (Sweden)

    Correia A.N.

    1999-01-01

    Full Text Available The electrocatalytic oxidation of formic acid and formaldehyde on Pd and on amorphous Pd(Si was studied by cyclic voltammetry and the results compared with the literature for similar systems. The oxidation of HCOOH on Pd occurs through direct catalytic dehydrogenation via (:C(OH2ads while on Pd(Si this intermediate does not appear to be formed. This is a consequence of the presence of inert Si on the surface that diminishes the probability of adjacent free sites. At high HCOOH concentrations, that intermediate undergoes dehydration on the Pd surface and COads oxidation peak is observed. For HCHO, the oxidation mechanism on both electrode materials appears similar to that previously proposed for Pt. However, the oxides formed on the amorphous Pd(Si alloy are more reactive than those on Pd thus affecting the overall kinetics of the process for both organic molecules, a fact revealed by the increase in anodic currents observed in the voltammograms.

  2. Impact of iron, chelators, and free fatty acids on lipid oxidation in low-moisture crackers.

    Science.gov (United States)

    Barden, Leann; Vollmer, Daniel; Johnson, David; Decker, Eric

    2015-02-18

    This research strove to understand the relationship between physical structure and oxidative stability in crackers since mechanisms of lipid oxidation are poorly understood in low-moisture foods. Confocal microscopy showed that lipids formed a continuous matrix surrounding starch granules, and starch-lipid, lipid-air, and protein-lipid interfaces were observed. Unlike bulk oils, meats, and emulsions, lipid hydroperoxides exhibited greater stability in low-moisture crackers as hexanal formation was delayed >20 d. Iron, added at 10 times the concentrations normally found in enriched flour, did not increase oxidation rates compared to the control. EDTA may reduce endogenous iron activity but not as greatly as in other matrices. Addition of fatty acids up to 1.0% of total lipid weight did not statistically affect lipid oxidation lag phases. The unique structure of low-moisture foods clearly affects their resistance to metal-promoted lipid oxidation.

  3. Counteracting oxidative stress in pregnancy through modulation of maternal micronutrients and omega-3 fatty acids.

    Science.gov (United States)

    D'Souza, V; Chavan-Gautam, P; Joshi, S

    2013-01-01

    During pregnancy, oxidative stress has been implicated in the pathophysiology of preeclampsia and preterm birth leading to poor birth outcome. Hyperhomocysteinemia caused as a consequence of altered micronutrients like folic acid and vitamin B12 is associated with increased production of reactive oxygen species that generate oxidative stress. These micronutrients are important determinants of methyl donor, s-adenosyl methionine while phospholipids are important methyl acceptors in the one-carbon metabolic cycle. A series of our studies in women during pregnancy have demonstrated altered levels of these micronutrients and the negative association of docosahexaenoic acid with homocysteine. Various strategies to counteract oxidative stress during pregnancy such as antioxidant therapy have been examined and found to be inconsistent. In this review, we focus on the role of oxidative stress in pregnancy and discuss the possibility of ameliorating it through modulation of maternal micronutrients and omega 3 fatty acids especially docosahexaenoic acid. We propose for the first time that manipulation of one-carbon metabolism by maternal diet could be a potential mechanism to counteract oxidative stress through homocysteine lowering effects and help in reducing the risk for adverse pregnancy outcomes.

  4. Dynamic simulations on the mitochondrial fatty acid Beta-oxidation network

    Directory of Open Access Journals (Sweden)

    Weinberger Klaus M

    2009-01-01

    Full Text Available Abstract Background The oxidation of fatty acids in mitochondria plays an important role in energy metabolism and genetic disorders of this pathway may cause metabolic diseases. Enzyme deficiencies can block the metabolism at defined reactions in the mitochondrion and lead to accumulation of specific substrates causing severe clinical manifestations. Ten of the disorders directly affecting mitochondrial fatty acid oxidation have been well-defined, implicating episodic hypoketotic hypoglycemia provoked by catabolic stress, multiple organ failure, muscle weakness, or hypertrophic cardiomyopathy. Additionally, syndromes of severe maternal illness (HELLP syndrome and AFLP have been associated with pregnancies carrying a fetus affected by fatty acid oxidation deficiencies. However, little is known about fatty acids kinetics, especially during fasting or exercise when the demand for fatty acid oxidation is increased (catabolic stress. Results A computational kinetic network of 64 reactions with 91 compounds and 301 parameters was constructed to study dynamic properties of mitochondrial fatty acid β-oxidation. Various deficiencies of acyl-CoA dehydrogenase were simulated and verified with measured concentrations of indicative metabolites of screened newborns in Middle Europe and South Australia. The simulated accumulation of specific acyl-CoAs according to the investigated enzyme deficiencies are in agreement with experimental data and findings in literature. Investigation of the dynamic properties of the fatty acid β-oxidation reveals that the formation of acetyl-CoA – substrate for energy production – is highly impaired within the first hours of fasting corresponding to the rapid progress to coma within 1–2 hours. LCAD deficiency exhibits the highest accumulation of fatty acids along with marked increase of these substrates during catabolic stress and the lowest production rate of acetyl-CoA. These findings might confirm gestational loss to

  5. 40 CFR 721.3680 - Ethylene oxide adduct of fatty acid ester with pentaerythritol.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Ethylene oxide adduct of fatty acid... New Uses for Specific Chemical Substances § 721.3680 Ethylene oxide adduct of fatty acid ester with... identified generically as ethylene oxide adduct of fatty acid ester with pentaerythritol (PMN P-91-442) is...

  6. Mutation analysis in mitochondrial fatty acid oxidation defects

    DEFF Research Database (Denmark)

    Gregersen, N; Andresen, B S; Corydon, M J

    2001-01-01

    Mutation analysis of metabolic disorders, such as the fatty acid oxidation defects, offers an additional, and often superior, tool for specific diagnosis compared to traditional enzymatic assays. With the advancement of the structural part of the Human Genome Project and the creation of mutation...... databases, procedures for convenient and reliable genetic analyses are being developed. The most straightforward application of mutation analysis is to specific diagnoses in suspected patients, particularly in the context of family studies and for prenatal/preimplantation analysis. In addition, from...... of mitochondrial fatty acid oxidation: very-long chain acyl-CoA dehydrogenase (VLCAD, also ACADVL), medium-chain acyl-CoA dehydrogenase (MCAD, also ACADM), and short-chain acyl-CoA dehydrogenase (SCAD, also ACADS) deficiencies. On the basis of this knowledge we discuss current understanding of the structural...

  7. Ozone oxidation of oleic acid surface films decreases aerosol cloud condensation nuclei activity

    Science.gov (United States)

    Schwier, A. N.; Sareen, N.; Lathem, T. L.; Nenes, A.; McNeill, V. F.

    2011-08-01

    Heterogeneous oxidation of aerosols composed of pure oleic acid (C18H34O2, an unsaturated fatty acid commonly found in continental and marine aerosol) by gas-phase O3 is known to increase aerosol hygroscopicity and activity as cloud condensation nuclei (CCN). Whether this trend is preserved when the oleic acid is internally mixed with other electrolytes is unknown and addressed in this study. We quantify the CCN activity of sodium salt aerosols (NaCl and Na2SO4) internally mixed with sodium oleate (SO) and oleic acid (OA). We find that particles containing roughly one monolayer of SO/OA show similar CCN activity to pure salt particles, whereas a tenfold increase in organic concentration slightly depresses CCN activity. O3 oxidation of these multicomponent aerosols has little effect on the critical diameter for CCN activation for unacidified particles at all conditions studied, and the activation kinetics of the CCN are similar in each case to those of pure salts. SO-containing particles which are acidified to atmospherically relevant pH before analysis in order to form oleic acid, however, show depressed CCN activity upon oxidation. This effect is more pronounced at higher organic concentrations. The behavior after oxidation is consistent with the disappearance of the organic surface film, supported by Köhler Theory Analysis (KTA). The κ-Köhler calculations show a small decrease in hygroscopicity after oxidation. The important implication of this finding is that oxidative aging may not always enhance the hygroscopicity of internally mixed inorganic-organic aerosols.

  8. Increased endogenous DNA oxidation correlates to increased iron levels in melanocytes relative to keratinocytes.

    Science.gov (United States)

    Pelle, Edward; Huang, Xi; Zhang, Qi; Pernodet, Nadine; Yarosh, Daniel B; Frenkel, Krystyna

    2014-01-01

    The endogenous oxidative state of normal human epidermal melanocytes was investigated and compared to normal human epidermal keratinocytes (NHEKs) in order to gain new insight into melanocyte biology. Previously, we showed that NHEKs contain higher levels of hydrogen peroxide (H2O2) than melanocytes and that it can migrate from NHEKs to melanocytes by passive permeation. Nevertheless, despite lower concentrations of H2O2, we now report higher levels of oxidative DNA in melanocytes as indicated by increased levels of 8-oxo-2'-deoxyguanosine (8-oxo-dG): 4.49 (±0.55 SEM) 8-oxo-dG/10(6) dG compared to 1.49 (±0.11 SEM) 8-oxo-dG/10(6) dG for NHEKs. An antioxidant biomarker, glutathione (GSH), was also lower in melanocytes (3.14 nmoles (±0.15 SEM)/cell) in comparison to NHEKs (5.98 nmoles (±0.33 SEM)/cell). Intriguingly, cellular bioavailable iron as measured in ferritin was found to be nearly fourfold higher in melanocytes than in NHEKs. Further, ferritin levels in melanocytes were also higher than in hepatocarcinoma cells, an iron-rich cell, and it indicates that higher relative iron levels may be characteristic of melanocytes. To account for the increased oxidative DNA and lower GSH and H2O2 levels that we observe, we propose that iron may contribute to higher levels of oxidation by reacting with H2O2 through a Fenton reaction leading to the generation of DNA-reactive hydroxyl radicals. In conclusion, our data support the concept of elevated oxidation and high iron levels as normal parameters of melanocytic activity. We present new evidence that may contribute to our understanding of the melanogenic process and lead to the development of new skin care products.

  9. Electrocatalysis by nanoparticles: Oxidation of formic acid at manganese oxide nanorods-modified Pt planar and nanohole-arrays

    OpenAIRE

    El-Deab, Mohamed S.

    2010-01-01

    The electro-oxidation of formic acid (an essential reaction in direct formic acid fuel cells) is a challenging process because of the deactivation of anodes by the adsorption of the poisoning intermediate carbon monoxide (CO). Pt electrodes in two geometries (planar and nanohole-array) were modified by the electrodeposition of manganese oxide nanorods (nano-MnOx). The modified Pt electrodes were then tested for their electrocatalytic activity through the electro-oxidation of formic acid in a ...

  10. Graphene Oxide-Gallic Acid Nanodelivery System for Cancer Therapy

    OpenAIRE

    Dorniani, D.; Saifullah, B.; Barahuie, F.; Arulselvan, P.; Hussein, M.Z.; Fakurazi, S; Twyman, L.J.

    2016-01-01

    Despite the technological advancement in the biomedical science, cancer remains a life-threatening disease. In this study, we designed an anticancer nanodelivery system using graphene oxide (GO) as nanocarrier for an active anticancer agent gallic acid (GA). The successful formation nanocomposite (GOGA) was characterized using XRD, FTIR, HRTEM, Raman, and UV/Vis spectroscopy. The release study shows that the release of GA from the designed anticancer nanocomposite (GOGA) occurs in a sustained...

  11. Kinetics and Mechanism of Oxidation of Aromatic Aldehydes by Imidazolium Dichromate in Aqueous Acetic Acid Medium

    Directory of Open Access Journals (Sweden)

    S. Sheik Mansoor

    2009-01-01

    Full Text Available The kinetics of oxidation of benzaldehyde (BA and para-substituted benzaldehydes by imidazolium dichromate (IDC has been studied in aqueous acetic acid medium in the presence of perchloric acid. The reaction is first order each in [IDC], [Substrate] and [H+]. The reaction rates have been determined at different temperatures and the activation parameters calculated. Electron withdrawing substituents are found to increase the reaction and electron releasing substituents are found to retard the rate of the reaction and the rate data obey the Hammett relationship. The products of the oxidation are the corresponding acids. The rate decreases with the increase in the water content of the medium. A suitable mechanism is proposed.

  12. Does acute psychological stress increase perception of oesophageal acid?

    NARCIS (Netherlands)

    Hemmink, G. J. M.; Bredenoord, A. J.; Weusten, B. L. A. M.; Timmer, R.; Smout, A. J. P. M.

    2009-01-01

    Gastro-oesophageal reflux disease (GORD) patients often report an increase in their reflux symptoms during stressful situations. The aim of this study was to assess the influence of acute psychological stress on oesophageal acid perception. In 15 healthy volunteers and 10 GORD patients with a

  13. Does acute psychological stress increase perception of oesophageal acid?

    NARCIS (Netherlands)

    Hemmink, G. J. M.; Bredenoord, A. J.; Weusten, B. L. A. M.; Timmer, R.; Smout, A. J. P. M.

    2009-01-01

    P>Gastro-oesophageal reflux disease (GORD) patients often report an increase in their reflux symptoms during stressful situations. The aim of this study was to assess the influence of acute psychological stress on oesophageal acid perception. In 15 healthy volunteers and 10 GORD patients with a

  14. Cold exposure increases exercise-induced oxidative stress.

    Science.gov (United States)

    Martarelli, D; Cocchioni, M; Scuri, S; Spataro, A; Pompei, P

    2011-06-01

    We determined the combined effects of cold and exercise on oxidative stress during submaximal exercise. Sixteen amateur male cyclists pedaled at a constant speed corresponding to 85% of maximal HR as determined in normal conditions. Eight athletes pedaled indoors at 23 °C while 8 athletes pedaled outdoors at a temperature of 4-6 °C. We then evaluated the levels of reactive oxygen metabolites and plasma levels of antioxidants after exercise. Performing a physical task in cold conditions increased the free radical production, as demonstrated by the augmented levels of reactive oxygen metabolites and the concomitant decrease of plasma levels of antioxidants in outdoors cyclists as compared to indoors cyclists. The overall ANOVA and the post-hoc comparisons revealed a significant exercise and temperature effect. The mean level of reactive oxygen metabolites in athletes who exercised indoors was significantly lower than that of the outdoor athletes. Moreover, the outdoors group presented plasma levels of antioxidants significantly lower than those of the indoors group. Since several sports are performed outdoors during the winter season, the increased risk of oxidative stress in cold conditions must be considered in these disciplines. Cyclists, football and rugby players, and runners are all affected by the elevation in oxygen radicals induced by cold and should take appropriate precautions, such as specific antioxidant integration.

  15. Maternal obesity increases oxidative stress in the newborn.

    Science.gov (United States)

    Gallardo, Juan Manuel; Gómez-López, Jaqueline; Medina-Bravo, Patricia; Juárez-Sánchez, Francisco; Contreras-Ramos, Alejandra; Galicia-Esquivel, Matilde; Sánchez-Urbina, Rocío; Klünder-Klünder, Miguel

    2015-08-01

    Obesity before pregnancy is associated with a greater risk for the offspring to develop obesity and diabetes in childhood and adulthood. The aim of the present study was to determine the association between maternal overweight or obesity before pregnancy and newborn oxidative stress (OS). Seventy-two mother-child pairs were divided according to the pre-gestational body mass index (BMI) of the mothers as follows: eutrophic (n = 21), overweight (n = 32), and obese (n = 19). Malondialdehyde (MDA) and nitric oxide (NO) were measured in the plasma of a blood sample from the newborn's umbilical cord. The MDA levels of newborns increased with maternal BMI (P = 0.001), as did the levels of NO (P = 0.019). There was a direct correlation between MDA and NO levels in each of the three groups (eutrophic: R(2)  = 0.59, P obese: R(2)  = 0.26, P = 0.024). Maternal overweight and obesity before pregnancy are associated with increased OS in the offspring. © 2015 The Obesity Society.

  16. Oxidation of amino acids and proteins by peroxynitrite

    Energy Technology Data Exchange (ETDEWEB)

    Lacsamana, M.; Gebicki, J. [Macquarie Univ., North Ryde, NSW (Australia). School of Biological Sciences

    1996-12-31

    Recent studies suggested that proteins exposed to free radicals and other strong oxidants generated by living organisms may be the source of damage to tissues even at sites distant from the original point of generation of the reactive species. In examining the ability of biologically significant oxidizing agents to generate protein peroxides, the authors have studied protein peroxidation by peroxynitrite (ONOO{sup -}), known to be a potential source of tissue damage. Treatment of bovine serum albumin, Iysozyme, apotransferrin, insulin or human serum albumin with peroxynitrous acid (POXNA) led to formation of hydroperoxide groups on the proteins, detected by their reaction with iodide. Under optimum conditions, up to one peroxide group formed on each molecule of protein. Hydroxyl radical scavengers, antioxidants, or metal chelators, were unable to affect the quantities of peroxides generated by POXNA. These findings suggest that the oxidation was not mediated by the hydroxyl free radicals. The iodide assay cannot be applied to the measurement of peroxides in presence of nitrite, which is a contaminant of most solutions of POXNA. Nitrite can be easily removed from proteins by molecular filtration, but this method cannot be applied to amino acids. Therefore an amino acid peroxide test based on chemiluminescence was used, which shows promise for general peroxide detection. Extended abstract. 2 refs.

  17. Myocardial carnitine palmitoyltransferase I expression and long-chain fatty acid oxidation in fetal and newborn lambs

    NARCIS (Netherlands)

    Bartelds, B; Takens, J; Smid, GB; Zammit, VA; Prip-Buus, C; Kuipers, JRG; van der Leij, FR

    Carnitine palmitoyltransferase I (CPT I) catalyzes the conversion of acyl-CoA to acylcarnitine at the outer mitochondrial membrane and is a key enzyme in the control of long-chain fatty acid ( LC- FA) oxidation. Because myocardial LC- FA oxidation increases dramatically after birth, we determined

  18. Oxidation in fresh and spray-dried omega 3 and omega 6 fatty acid enriched eggs. Vitamin E and canthaxantin

    OpenAIRE

    Galobart i Cots, Jaume

    2003-01-01

    Consumption of products enriched in co3 fatty acids such broiler meat or eggs are associated to health benefits. However, the increase in unsaturation of the lipids present in the food may cause a reduction in its oxidative stability, decreasing its nutritive and organoleptic value and producing toxic lipid oxidation products. Supplementation of animal diets with natural antioxidants

  19. Mutant E. coli strain with increased succinic acid production

    Science.gov (United States)

    Donnelly, Mark; Millard, Cynthia S.; Stols, Lucy

    2001-09-25

    A method for isolating succinic acid producing bacteria is provided comprising increasing the biomass of an organism which lacks the ability to catabolize pyruvate, and then subjecting the biomass to glucose-rich medium in an anaerobic environment to enable pyruvate-catabolizing mutants to grow. The invention also provides for a mutant that produces high amounts of succinic acid, which has been derived from a parent which lacked the genes for pyruvate formate lyase and lactate dehydrogenase, and which belongs to the E.coli Group of Bacteria.

  20. Mutant E. coli strain with increased succinic acid production

    Science.gov (United States)

    Donnelly, Mark; Millard, Cynthia S.; Stols, Lucy

    1998-01-01

    A method for isolating succinic acid producing bacteria is provided comprising increasing the biomass of an organism which lacks the ability to catabolize pyruvate, and then subjecting the biomass to glucose-rich medium in an anaerobic environment to enable pyruvate-catabolizing mutants to grow. The invention also provides for a mutant that produces high amounts of succinic acid, which as been derived from a parent which lacked the genes for pyruvate formate lyase and lactate dehydrogenase, and which belongs to the E.coli Group of Bacteria.

  1. Structure and friction of stearic acid and oleic acid films adsorbed on iron oxide surfaces in squalane.

    Science.gov (United States)

    Doig, Michael; Warrens, Chris P; Camp, Philip J

    2014-01-14

    The structure and friction of fatty acid surfactant films adsorbed on iron oxide surfaces lubricated by squalane are examined using large-scale molecular dynamics simulations. The structures of stearic acid and oleic acid films under static and shear conditions, and at various surface coverages, are described in detail, and the effects of unsaturation in the tail group are highlighted. At high surface coverage, the measured properties of stearic acid and oleic acid films are seen to be very similar. At low and intermediate surface coverages, the presence of a double bond, as in oleic acid, is seen to give rise to less penetration of lubricant in to the surfactant film and less layering of the lubricant near to the film. The kinetic friction coefficient is measured as a function of shear rate within the hydrodynamic (high shear rate) lubrication regime. Lubricant penetration and layering are observed to be correlated with friction coefficient. The friction coefficient with oleic acid depends only weakly on surface coverage, while stearic acid admits more lubricant penetration, and its friction coefficient increases significantly with decreasing surface coverage. Connections between film structure and friction are discussed.

  2. Activated Persulfate Oxidation of Perfluorooctanoic Acid (PFOA in Groundwater under Acidic Conditions

    Directory of Open Access Journals (Sweden)

    Penghua Yin

    2016-06-01

    Full Text Available Perfluorooctanoic acid (PFOA is an emerging contaminant of concern due to its toxicity for human health and ecosystems. However, successful degradation of PFOA in aqueous solutions with a cost-effective method remains a challenge, especially for groundwater. In this study, the degradation of PFOA using activated persulfate under mild conditions was investigated. The impact of different factors on persulfate activity, including pH, temperature (25 °C–50 °C, persulfate dosage and reaction time, was evaluated under different experimental conditions. Contrary to the traditional alkaline-activated persulfate oxidation, it was found that PFOA can be effectively degraded using activated persulfate under acidic conditions, with the degradation kinetics following the pseudo-first-order decay model. Higher temperature, higher persulfate dosage and increased reaction time generally result in higher PFOA degradation efficiency. Experimental results show that a PFOA degradation efficiency of 89.9% can be achieved by activated persulfate at pH of 2.0, with the reaction temperature of 50 °C, molar ratio of PFOA to persulfate as 1:100, and a reaction time of 100 h. The corresponding defluorination ratio under these conditions was 23.9%, indicating that not all PFOA decomposed via fluorine removal. The electron paramagnetic resonance spectrometer analysis results indicate that both SO4−• and •OH contribute to the decomposition of PFOA. It is proposed that PFOA degradation occurs via a decarboxylation reaction triggered by SO4−•, followed by a HF elimination process aided by •OH, which produces one-CF2-unit-shortened perfluoroalkyl carboxylic acids (PFCAs, Cn−1F2n−1COOH. The decarboxylation and HF elimination processes would repeat and eventually lead to the complete mineralization all PFCAs.

  3. Engineering of TM1459 from Thermotoga maritima for Increased Oxidative Alkene Cleavage Activity.

    Science.gov (United States)

    Fink, Matthias; Trunk, Sarah; Hall, Mélanie; Schwab, Helmut; Steiner, Kerstin

    2016-01-01

    Oxidative cleavage of alkenes is a widely employed process allowing oxyfunctionalization to corresponding carbonyl compounds. Recently, a novel biocatalytic oxidative alkene cleavage activity on styrene derivatives was identified in TM1459 from Thermotoga maritima. In this work we engineered the enzyme by site-saturation mutagenesis of active site amino acids to increase its activity and to broaden its substrate scope. A high-throughput assay for the detection of the ketone products was successfully developed. Several variants with up to twofold improved conversion level of styrene derivatives were successfully identified. Especially, changes in or removal of the C-terminus of TM1459 increased the activity most significantly. These best variants also displayed a slightly enlarged substrate scope.

  4. Engineering of TM1459 from Thermotoga maritima for increased oxidative alkene cleavage activity

    Directory of Open Access Journals (Sweden)

    Matthias Fink

    2016-09-01

    Full Text Available Oxidative cleavage of alkenes is a widely employed process allowing oxyfunctionalization to corresponding carbonyl compounds. Recently, a novel biocatalytic oxidative alkene cleavage activity on styrene derivatives was identified in TM1459 from Thermotoga maritima. In this work we engineered the enzyme by site-saturation mutagenesis of active site amino acids to increase its activity and to broaden its substrate scope. A high-throughput assay for the detection of the ketone products was successfully developed. Several variants with up to two fold improved conversion level of styrene derivatives were successfully identified. Especially changes in or removal of the C-terminus of TM1459 increased the activity most significantly. These best variants also displayed a slightly enlarged substrate scope.

  5. Nitric oxide and salicylic acid signaling in plant defense

    Science.gov (United States)

    Klessig, Daniel F.; Durner, Jörg; Noad, Robert; Navarre, Duroy A.; Wendehenne, David; Kumar, Dhirendra; Zhou, Jun Ma; Shah, Jyoti; Zhang, Shuqun; Kachroo, Pradeep; Trifa, Youssef; Pontier, Dominique; Lam, Eric; Silva, Herman

    2000-01-01

    Salicylic acid (SA) plays a critical signaling role in the activation of plant defense responses after pathogen attack. We have identified several potential components of the SA signaling pathway, including (i) the H2O2-scavenging enzymes catalase and ascorbate peroxidase, (ii) a high affinity SA-binding protein (SABP2), (iii) a SA-inducible protein kinase (SIPK), (iv) NPR1, an ankyrin repeat-containing protein that exhibits limited homology to IκBα and is required for SA signaling, and (v) members of the TGA/OBF family of bZIP transcription factors. These bZIP factors physically interact with NPR1 and bind the SA-responsive element in promoters of several defense genes, such as the pathogenesis-related 1 gene (PR-1). Recent studies have demonstrated that nitric oxide (NO) is another signal that activates defense responses after pathogen attack. NO has been shown to play a critical role in the activation of innate immune and inflammatory responses in animals. Increases in NO synthase (NOS)-like activity occurred in resistant but not susceptible tobacco after infection with tobacco mosaic virus. Here we demonstrate that this increase in activity participates in PR-1 gene induction. Two signaling molecules, cGMP and cyclic ADP ribose (cADPR), which function downstream of NO in animals, also appear to mediate plant defense gene activation (e.g., PR-1). Additionally, NO may activate PR-1 expression via an NO-dependent, cADPR-independent pathway. Several targets of NO in animals, including guanylate cyclase, aconitase, and mitogen-activated protein kinases (e.g., SIPK), are also modulated by NO in plants. Thus, at least portions of NO signaling pathways appear to be shared between plants and animals. PMID:10922045

  6. The kinetics of oxidation of bilirubin and ascorbic acid in solution

    Science.gov (United States)

    Solomonov, A. V.; Rumyantsev, E. V.; Kochergin, B. A.; Antina, E. V.

    2012-07-01

    The results of a comparative study of the oxidation of bilirubin, ascorbic acid, and their mixture in aqueous solutions under the action of air oxygen and hydrogen peroxide are presented. The observed and true rate constants for the oxidation reactions were determined. It was shown that the oxidation of tetrapyrrole pigment occurred under these conditions bypassing the stage of biliverdin formation to monopyrrole products. Simultaneous oxidation of bilirubin and ascorbic acid was shown to be accompanied by the inhibition of ascorbic acid oxidation by bilirubin, whereas ascorbic acid itself activated the oxidation of bilirubin.

  7. Oxidation in Acidic Medium of Lignins from Agricultural Residues

    Science.gov (United States)

    Labat, Gisele Aparecida Amaral; Gonçalves, Adilson Roberto

    Agricultural residues as sugarcane straw and bagasse are burned in boilers for generation of energy in sugar and alcohol industries. However, excess of those by-products could be used to obtain products with higher value. Pulping process generates cellulosic pulps and lignin. The lignin could be oxidized and applied in effluent treatments for heavy metal removal. Oxidized lignin presents very strong chelating properties. Lignins from sugarcane straw and bagasse were obtained by ethanol-water pulping. Oxidation of lignins was carried out using acetic acid and Co/Mn/Br catalytical system at 50, 80, and 115 °C for 5 h. Kinetics of the reaction was accomplished by measuring the UV-visible region. Activation energy was calculated for lignins from sugarcane straw and bagasse (34.2 and 23.4 kJ mol-1, respectively). The first value indicates higher cross-linked formation. Fourier-transformed infrared spectroscopy data of samples collected during oxidation are very similar. Principal component analysis applied to spectra shows only slight structure modifications in lignins after oxidation reaction.

  8. Impaired amino acid metabolism contributes to fasting-induced hypoglycemia in fatty acid oxidation defects

    NARCIS (Netherlands)

    Houten, S.M.; Herrema, H.; Brinke, te H.; Denis, S.; Ruiter, J.P.N.; Dijk, van Th.; Argmann, C.A.; Ottenhoff, R.; Müller, M.R.; Groen, A.K.; Kuipers, F.; Reijngoud, D.J.; Wanders, R.J.A.

    2013-01-01

    The importance of mitochondrial fatty acid beta-oxidation (FAO) as a glucose-sparing process is illustrated by patients with inherited defects in FAO, who may present with life-threatening fasting-induced hypoketotic hypoglycemia. It is unknown why peripheral glucose demand outpaces hepatic

  9. Impaired amino acid metabolism contributes to fasting-induced hypoglycemia in fatty acid oxidation defects

    NARCIS (Netherlands)

    Houten, Sander M.; Herrema, Hilde; te Brinke, Heleen; Denis, Simone; Ruiter, Jos P. N.; van Dijk, Theo H.; Argmann, Carmen A.; Ottenhoff, Roelof; Müller, Michael; Groen, Albert K.; Kuipers, Folkert; Reijngoud, Dirk-Jan; Wanders, Ronald J. A.

    2013-01-01

    The importance of mitochondrial fatty acid β-oxidation (FAO) as a glucose-sparing process is illustrated by patients with inherited defects in FAO, who may present with life-threatening fasting-induced hypoketotic hypoglycemia. It is unknown why peripheral glucose demand outpaces hepatic

  10. Relationship between fatty acid delivery and fatty acid oxidation during strenuous exercise

    NARCIS (Netherlands)

    Romijn, J. A.; Coyle, E. F.; Sidossis, L. S.; Zhang, X. J.; Wolfe, R. R.

    1995-01-01

    To evaluate the extent to which decreased plasma free fatty acid (FFA) concentration contributes to the relatively low rates of fat oxidation during high-intensity exercise, we studied FFA metabolism in six endurance-trained cyclists during 20-30 min of exercise [85% of maximal O2 uptake (VO2max)].

  11. Combined atmospheric oxidant capacity and increased levels of exhaled nitric oxide

    Science.gov (United States)

    Yang, Changyuan; Li, Huichu; Chen, Renjie; Xu, Wenxi; Wang, Cuicui; Tse, Lap Ah; Zhao, Zhuohui; Kan, Haidong

    2016-07-01

    Nitrogen dioxide and ozone are two interrelated oxidative pollutants in the atmosphere. Few studies have evaluated the health effects of combined oxidant capacity (O x ). We investigated the short-term effects of O x on fractional exhaled nitric oxide (FeNO), a well-established biomarker for airway inflammation, in a group of chronic obstructive pulmonary disease patients. Real-time concentrations of O x were obtained by calculating directly the sum of nitrogen dioxide and ozone. Linear mixed-effect models were applied to explore the acute effects of O x on FeNO levels. Short-term exposure to Ox was significantly associated with elevated FeNO. This effect was strongest in the first 24 h after exposure, and was robust to the adjustment of PM2.5. A 10 μg m-3 increase in 24 h average concentrations of O x was associated with 4.28% (95% confidence interval: 1.19%, 7.37%) increase in FeNO. The effect estimates were statistically significant only among males, elders, and those with body mass index ≥24 kg m-2, a comorbidity, higher educational attainment, or moderate airflow limitation. This analysis demonstrated an independent effect of O x on respiratory inflammation, and suggested that a single metric O x might serve as a preferable indicator of atmospheric oxidative capacity in further air pollution epidemiological studies.

  12. 10-Oxo-trans-11-octadecenoic acid generated from linoleic acid by a gut lactic acid bacterium Lactobacillus plantarum is cytoprotective against oxidative stress.

    Science.gov (United States)

    Furumoto, Hidehiro; Nanthirudjanar, Tharnath; Kume, Toshiaki; Izumi, Yasuhiko; Park, Si-Bum; Kitamura, Nahoko; Kishino, Shigenobu; Ogawa, Jun; Hirata, Takashi; Sugawara, Tatsuya

    2016-04-01

    Oxidative stress is a well-known cause of multiple diseases. The nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant response element (ARE) pathway plays a central role in cellular antioxidative responses. In this study, we investigated the effects of novel fatty acid metabolite derivatives of linoleic acid generated by the gut lactic acid bacteria Lactobacillus plantarum on the Nrf2-ARE pathway. 10-Oxo-trans-11-octadecenoic acid (KetoC) protected HepG2 cells from cytotoxicity induced by hydrogen peroxide. KetoC also significantly increased cellular Nrf2 protein levels, ARE-dependent transcription, and the gene expression of antioxidative enzymes such as heme oxygenase-1 (HO-1), glutamate-cysteine ligase modifier subunit (GCLM), and quinone oxidoreductase 1 (NQO1) in HepG2 cells. Additionally, a single oral dose administration of KetoC also increased antioxidative gene expression and protein levels of Nrf2 and HO-1 in mouse organs. Since other fatty acid metabolites and linoleic acid did not affect cellular antioxidative responses, the cytoprotective effect of KetoC may be because of its α,β-unsaturated carbonyl moiety. Collectively, our data suggested that KetoC activated the Nrf2-ARE pathway to enhance cellular antioxidative responses in vitro and in vivo, which further suggests that KetoC may prevent multiple diseases induced by oxidative stress. Copyright © 2016. Published by Elsevier Inc.

  13. Oleic, Linoleic and Linolenic Acids Increase ROS Production by Fibroblasts via NADPH Oxidase Activation

    Science.gov (United States)

    Hatanaka, Elaine; Dermargos, Alexandre; Hirata, Aparecida Emiko; Vinolo, Marco Aurélio Ramirez; Carpinelli, Angelo Rafael; Newsholme, Philip; Armelin, Hugo Aguirre; Curi, Rui

    2013-01-01

    The effect of oleic, linoleic and γ-linolenic acids on ROS production by 3T3 Swiss and Rat 1 fibroblasts was investigated. Using lucigenin-amplified chemiluminescence, a dose-dependent increase in extracellular superoxide levels was observed during the treatment of fibroblasts with oleic, linoleic and γ-linolenic acids. ROS production was dependent on the addition of β-NADH or NADPH to the medium. Diphenyleneiodonium inhibited the effect of oleic, linoleic and γ-linolenic acids on fibroblast superoxide release by 79%, 92% and 82%, respectively. Increased levels of p47phox phosphorylation due to fatty acid treatment were detected by Western blotting analyses of fibroblast proteins. Increased p47phox mRNA expression was observed using real-time PCR. The rank order for the fatty acid stimulation of the fibroblast oxidative burst was as follows: γ-linolenic > linoleic > oleic. In conclusion, oleic, linoleic and γ-linolenic acids stimulated ROS production via activation of the NADPH oxidase enzyme complex in fibroblasts. PMID:23579616

  14. Valorization of Lignin by Partial Wet Oxidation Using Sustainable Heteropoly Acid Catalysts

    Directory of Open Access Journals (Sweden)

    Abayneh Getachew Demesa

    2017-09-01

    Full Text Available The production of carboxylic acids by partial wet oxidation of alkali lignin at elevated temperatures and pressures was studied experimentally. Two different heteropoly acids, phosphotungstic acid (H3PW12O40 and phosphomolybdic acid (H3PMo12O40, were used to catalyze the oxidation of lignin under hydrothermal conditions. Factors influencing the total yield of carboxylic acids formed during the partial oxidation of lignin were investigated. Formic, acetic and succinic acids were the major products identified. Of the two catalysts used, phosphomolybdic acid gave the most promising results, with carboxylic acid yields and lignin conversions of up to 45% and 95%, respectively.

  15. Exogenous amino acids suppress glucose oxidation and potentiate hepatic glucose production in late gestation fetal sheep.

    Science.gov (United States)

    Brown, Laura D; Kohn, Jaden R; Rozance, Paul J; Hay, William W; Wesolowski, Stephanie R

    2017-05-01

    Acute amino acid (AA) infusion increases AA oxidation rates in normal late gestation fetal sheep. Because the fetal oxygen consumption rate does not change with increased AA oxidation, we hypothesized that AA infusion would suppress glucose oxidation pathways and that the additional carbon supply from AA would activate hepatic glucose production. To test this, late gestation fetal sheep were infused intravenously for 3 h with saline or exogenous AA (AA). Glucose tracer metabolic studies were performed and skeletal muscle and liver tissues samples were collected. AA infusion increased fetal arterial plasma branched chain AA, cortisol, and glucagon concentrations. Fetal glucose utilization rates were similar between basal and AA periods, yet the fraction of glucose oxidized and the glucose oxidation rate were decreased by 40% in the AA period. AA infusion increased expression of PDK4 , an inhibitor of glucose oxidation, nearly twofold in muscle and liver. In liver, AA infusion tended to increase PCK1 gluconeogenic gene and PCK1 correlated with plasma cortisol concentrations. AA infusion also increased liver mRNA expression of the lactate transporter gene ( MCT1) , protein expression of GLUT2 and LDHA, and phosphorylation of AMPK, 4EBP1, and S6 proteins. In isolated fetal hepatocytes, AA supplementation increased glucose production and PCK1 , LDHA , and MCT1 gene expression. These results demonstrate that AA infusion into fetal sheep competitively suppresses glucose oxidation and potentiates hepatic glucose production. These metabolic patterns support flexibility in fetal metabolism in response to increased nutrient substrate supply while maintaining a relatively stable rate of oxidative metabolism. Copyright © 2017 the American Physiological Society.

  16. Effects of fulvic acid on Fe(II) oxidation by hydrogen peroxide

    Energy Technology Data Exchange (ETDEWEB)

    Voelker, B.M.; Sulzberger, B. [Swiss Federal Inst. for Environmental Science and Technology (EAWAG), Duebendorf (Switzerland)

    1996-04-01

    Iron redox cycling can catalyze the oxidation of humic substances and increase the rate of oxygen consumption in surface waters rich in iron and organic carbon. This study examines the role of Fenton`s reaction [oxidation of Fe(II) by hydrogen peroxide] in this catalytic cycle. A number of competing processes were observed in model systems containing dissolved Fe, hydrogen peroxide, and Suwannee River fulvic acid. First, the effective rate constant of Fenton`s reaction increased with increasing fulvic acid concentration, indicating the formation Fe(II)-fulvate complexes that react more rapidly with hydrogen peroxide than Fe(II)-aquo complexes. This effect was significant at pH 5 but negligible at pH 3. A second effect was scavenging of the HO{sup .} radical produced in Fenton`s reaction by fulvic acid, forming an organic radical. The organic radical reduced oxygen to HO{sub 2}{sup .}/O{sub 2}{sup .-}, which then regenerated hydrogen peroxide by reaction with Fe(II). Finally, Fe(III) was reduced by a dark reaction with fulvic acid, characterized by an initially fast reduction followed by slower processes. The behavior of Fe(II) and hydrogen peroxide over time in the presence of fulvic acid and oxygen could be described by a kinetic model taking all of these reactions into account. The net result was an iron redox cycle in which hydrogen peroxide as well as oxygen were consumed (even though direct oxidation of Fe(II) by oxygen was not significant), and the oxidation of fulvic acid was accelerated. 56 refs., 7 figs., 1 tab.

  17. Reduction Rates for Higher Americium Oxidation States in Nitric Acid

    Energy Technology Data Exchange (ETDEWEB)

    Grimes, Travis Shane [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mincher, Bruce Jay [Idaho National Lab. (INL), Idaho Falls, ID (United States); Schmitt, Nicholas C [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-30

    The stability of hexavalent americium was measured using multiple americium concentrations and nitric acid concentrations after contact with the strong oxidant sodium bismuthate. Contrary to our hypotheses Am(VI) was not reduced faster at higher americium concentrations, and the reduction was only zero-order at short time scales. Attempts to model the reduction kinetics using zero order kinetic models showed Am(VI) reduction in nitric acid is more complex than the autoreduction processes reported by others in perchloric acid. The classical zero-order reduction of Am(VI) was found here only for short times on the order of a few hours. We did show that the rate of Am(V) production was less than the rate of Am(VI) reduction, indicating that some Am(VI) undergoes two electron-reduction to Am(IV). We also monitored the Am(VI) reduction in contact with the organic diluent dodecane. A direct comparison of these results with those in the absence of the organic diluent showed the reduction rates for Am(VI) were not statistically different for both systems. Additional americium oxidations conducted in the presence of Ce(IV)/Ce(III) ions showed that Am(VI) is reduced without the typical growth of Am(V) observed in the systems sans Ce ion. This was an interesting result which suggests a potential new reduction/oxidation pathway for Am in the presence of Ce; however, these results were very preliminary, and will require additional experiments to understand the mechanism by which this occurs. Overall, these studies have shown that hexavalent americium is fundamentally stable enough in nitric acid to run a separations process. However, the complicated nature of the reduction pathways based on the system components is far from being rigorously understood.

  18. Activation of peroxisome proliferator-activated receptor-{alpha} enhances fatty acid oxidation in human adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joo-Young; Hashizaki, Hikari; Goto, Tsuyoshi; Sakamoto, Tomoya; Takahashi, Nobuyuki [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011 (Japan); Kawada, Teruo, E-mail: fat@kais.kyoto-u.ac.jp [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011 (Japan)

    2011-04-22

    Highlights: {yields} PPAR{alpha} activation increased mRNA expression levels of adipocyte differentiation marker genes and GPDH activity in human adipocytes. {yields} PPAR{alpha} activation also increased insulin-dependent glucose uptake in human adipocytes. {yields} PPAR{alpha} activation did not affect lipid accumulation in human adipocytes. {yields} PPAR{alpha} activation increased fatty acid oxidation through induction of fatty acid oxidation-related genes in human adipocytes. -- Abstract: Peroxisome proliferator-activated receptor-{alpha} (PPAR{alpha}) is a key regulator for maintaining whole-body energy balance. However, the physiological functions of PPAR{alpha} in adipocytes have been unclarified. We examined the functions of PPAR{alpha} using human multipotent adipose tissue-derived stem cells as a human adipocyte model. Activation of PPAR{alpha} by GW7647, a potent PPAR{alpha} agonist, increased the mRNA expression levels of adipocyte differentiation marker genes such as PPAR{gamma}, adipocyte-specific fatty acid-binding protein, and lipoprotein lipase and increased both GPDH activity and insulin-dependent glucose uptake level. The findings indicate that PPAR{alpha} activation stimulates adipocyte differentiation. However, lipid accumulation was not changed, which is usually observed when PPAR{gamma} is activated. On the other hand, PPAR{alpha} activation by GW7647 treatment induced the mRNA expression of fatty acid oxidation-related genes such as CPT-1B and AOX in a PPAR{alpha}-dependent manner. Moreover, PPAR{alpha} activation increased the production of CO{sub 2} and acid soluble metabolites, which are products of fatty acid oxidation, and increased oxygen consumption rate in human adipocytes. The data indicate that activation of PPAR{alpha} stimulates both adipocyte differentiation and fatty acid oxidation in human adipocytes, suggesting that PPAR{alpha} agonists could improve insulin resistance without lipid accumulation in adipocytes. The expected

  19. Increased oxidative phosphorylation in response to acute and chronic DNA damage.

    Science.gov (United States)

    Brace, Lear E; Vose, Sarah C; Stanya, Kristopher; Gathungu, Rose M; Marur, Vasant R; Longchamp, Alban; Treviño-Villarreal, Humberto; Mejia, Pedro; Vargas, Dorathy; Inouye, Karen; Bronson, Roderick T; Lee, Chih-Hao; Neilan, Edward; Kristal, Bruce S; Mitchell, James R

    2016-01-01

    Accumulation of DNA damage is intricately linked to aging, aging-related diseases and progeroid syndromes such as Cockayne syndrome (CS). Free radicals from endogenous oxidative energy metabolism can damage DNA, however the potential of acute or chronic DNA damage to modulate cellular and/or organismal energy metabolism remains largely unexplored. We modeled chronic endogenous genotoxic stress using a DNA repair-deficient Csa -/- |Xpa -/- mouse model of CS. Exogenous genotoxic stress was modeled in mice in vivo and primary cells in vitro treated with different genotoxins giving rise to diverse spectrums of lesions, including ultraviolet radiation, intrastrand crosslinking agents and ionizing radiation. Both chronic endogenous and acute exogenous genotoxic stress increased mitochondrial fatty acid oxidation (FAO) on the organismal level, manifested by increased oxygen consumption, reduced respiratory exchange ratio, progressive adipose loss and increased FAO in tissues ex vivo . In multiple primary cell types, the metabolic response to different genotoxins manifested as a cell-autonomous increase in oxidative phosphorylation (OXPHOS) subsequent to a transient decline in steady-state NAD+ and ATP levels, and required the DNA damage sensor PARP-1 and energy-sensing kinase AMPK. We conclude that increased FAO/OXPHOS is a general, beneficial, adaptive response to DNA damage on cellular and organismal levels, illustrating a fundamental link between genotoxic stress and energy metabolism driven by the energetic cost of DNA damage. Our study points to therapeutic opportunities to mitigate detrimental effects of DNA damage on primary cells in the context of radio/chemotherapy or progeroid syndromes.

  20. Endoplasmic Reticulum Oxidative Stress Triggers Tgf-Beta-Dependent Muscle Dysfunction by Accelerating Ascorbic Acid Turnover

    Science.gov (United States)

    Pozzer, Diego; Favellato, Mariagrazia; Bolis, Marco; Invernizzi, Roberto William; Solagna, Francesca; Blaauw, Bert; Zito, Ester

    2017-01-01

    Endoplasmic reticulum (ER) and oxidative stress are two related phenomena that have important metabolic consequences. As many skeletal muscle diseases are triggered by oxidative stress, we explored the chain of events linking a hyperoxidized ER (which causes ER and oxidative stress) with skeletal muscle dysfunction. An unbiased exon expression array showed that the combined genetic modulation of the two master ER redox proteins, selenoprotein N (SEPN1) and endoplasmic oxidoreductin 1 (ERO1), led to an SEPN1-related myopathic phenotype due to excessive signalling of transforming growth factor (TGF)-beta. The increased TGF-beta activity in the genetic mutants was caused by accelerated turnover of the ER localized (anti-oxidant) ascorbic acid that affected collagen deposition in the extracellular matrix. In a mouse mutant of SEPN1, which is dependent on exogenous ascorbic acid, a limited intake of ascorbic acid revealed a myopathic phenotype as a consequence of an altered TGF-beta signalling. Indeed, systemic antagonism of TGF-beta re-established skeletal muscle function in SEPN1 mutant mice. In conclusion, this study sheds new light on the molecular mechanism of SEPN1-related myopathies and indicates that the TGF-beta/ERO1/ascorbic acid axis offers potential for their treatment. PMID:28106121

  1. Potentiometric studies of acid-base interactions in substituted 4-nitropyridine N-oxide systems

    Energy Technology Data Exchange (ETDEWEB)

    Gurzynski, Lukasz [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Puszko, Aniela [Department of Organic Chemistry, School of Economics, Wroclaw (Poland); Ostrzechowska, Agnieszka [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Makowski, Mariusz [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Chmurzynski, Lech [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland)]. E-mail: lech@chem.univ.gda.pl

    2006-05-15

    (Acid+base) equilibrium constants, involving the acidity (pK{sub a}{sup AC}) and cationic homoconjugation constants (in the form of lgK{sub BHB{sup +}}{sup AC}), have been determined by the potentiometric method in 13 systems formed by substituted 4-nitropyridine N-oxides in the polar aprotic solvent, acetone (AC). The derivatives covered a wide range of proton-acceptor properties and inherent diversified tendencies towards formation of hydrogen-bonded homocomplexed cations. In addition, the constant values (expressed as pK{sub a}{sup AN}andlgK{sub BHB{sup +}}{sup AN}) for two of the systems studied, N-oxides of 2-methylamino- and 2-ethylamino-4-nitropyridine, were determined in acetonitrile (AN). The acidity constants in the non-aqueous media studied have been found to change in line with their substituent effects and the sequence of acidity changes in water. The values of the cationic homoconjugation constants increased with increasing basicity of the N-oxides and decreased with increasing solvent basicity.

  2. Blends of rapeseed oil with black cumin and rice bran oils for increasing the oxidative stability.

    Science.gov (United States)

    Rudzińska, Magdalena; Hassanein, Minar M M; Abdel-Razek, Adel G; Ratusz, Katarzyna; Siger, Aleksander

    2016-02-01

    For the increase of oxidative stability and phytonutrient contents of rapeseed oil 5, 10 and 20 % blends with rice bran oil and black cumin oil were prepared. Profiles of different bioactive lipid components of blends including tocopherols, tocotrienols, phytosterols and phytostanols as well as fatty acid composition were carried out using HPLC and GLC. Rancimat was used for detecting oxidative stability of the fatty material. The blends with black cumin seed oil characterized higher level of α- and γ-tocopherols as well as all isomers of tocotrienols. Presence of rice bran oil in blends leads to increased tocotrienols amounts, β-sitosterol and squalene. Blending resulted in lowering ratio of PUFA/SFA and improves stability of these oils. The ratio of omega-6/omega-3 raises from 2.1 in rapeseed oil to 3.7 and 3.0 in blends with black cumin and rice bran oils, respectively. Addition of 10 and 20 % of black cumin and rice bran oils to rapeseed oil were influenced on the oxidative stability of prepared blends. The results appear that blending of rapeseed oil with black cumin seed oil or rice bran oil enhanced nutritional and functional properties via higher oxidative stability as well as improved phytonutrient contents.

  3. Hydroxyapatite formation on graphene oxide modified with amino acids: arginine versus glutamic acid

    Science.gov (United States)

    Tavafoghi, M.; Brodusch, N.; Gauvin, R.; Cerruti, M.

    2016-01-01

    Hydroxyapatite (HA, Ca5(PO4)3OH) is the main inorganic component of hard tissues, such as bone and dentine. HA nucleation involves a set of negatively charged phosphorylated proteins known as non-collagenous proteins (NCPs). These proteins attract Ca2+ and PO43− ions and increase the local supersaturation to a level required for HA precipitation. Polar and charged amino acids (AAs) are highly expressed in NCPs, and seem to be responsible for the mineralizing effect of NCPs; however, the individual effect of these AAs on HA mineralization is still unclear. In this work, we investigate the effect of a negatively charged (Glu) and positively charged (Arg) AA bound to carboxylated graphene oxide (CGO) on HA mineralization in simulated body fluids (SBF). Our results show that Arg induces HA precipitation faster and in larger amounts than Glu. We attribute this to the higher stability of the complexes formed between Arg and Ca2+ and PO43− ions, and also to the fact that Arg exposes both carboxyl and amino groups on the surface. These can electrostatically attract both Ca2+ and PO43− ions, thus increasing local supersaturation more than Glu, which exposes carboxyl groups only. PMID:26791001

  4. Hydroxyapatite formation on graphene oxide modified with amino acids: arginine versus glutamic acid.

    Science.gov (United States)

    Tavafoghi, M; Brodusch, N; Gauvin, R; Cerruti, M

    2016-01-01

    Hydroxyapatite (HA, Ca5(PO4)3OH) is the main inorganic component of hard tissues, such as bone and dentine. HA nucleation involves a set of negatively charged phosphorylated proteins known as non-collagenous proteins (NCPs). These proteins attract Ca(2+) and PO4(3-) ions and increase the local supersaturation to a level required for HA precipitation. Polar and charged amino acids (AAs) are highly expressed in NCPs, and seem to be responsible for the mineralizing effect of NCPs; however, the individual effect of these AAs on HA mineralization is still unclear. In this work, we investigate the effect of a negatively charged (Glu) and positively charged (Arg) AA bound to carboxylated graphene oxide (CGO) on HA mineralization in simulated body fluids (SBF). Our results show that Arg induces HA precipitation faster and in larger amounts than Glu. We attribute this to the higher stability of the complexes formed between Arg and Ca(2+) and PO4(3-) ions, and also to the fact that Arg exposes both carboxyl and amino groups on the surface. These can electrostatically attract both Ca(2+) and PO4(3-) ions, thus increasing local supersaturation more than Glu, which exposes carboxyl groups only. © 2016 The Author(s).

  5. Formic-acid-induced depolymerization of oxidized lignin to aromatics

    Science.gov (United States)

    Rahimi, Alireza; Ulbrich, Arne; Coon, Joshua J.; Stahl, Shannon S.

    2014-11-01

    Lignin is a heterogeneous aromatic biopolymer that accounts for nearly 30% of the organic carbon on Earth and is one of the few renewable sources of aromatic chemicals. As the most recalcitrant of the three components of lignocellulosic biomass (cellulose, hemicellulose and lignin), lignin has been treated as a waste product in the pulp and paper industry, where it is burned to supply energy and recover pulping chemicals in the operation of paper mills. Extraction of higher value from lignin is increasingly recognized as being crucial to the economic viability of integrated biorefineries. Depolymerization is an important starting point for many lignin valorization strategies, because it could generate valuable aromatic chemicals and/or provide a source of low-molecular-mass feedstocks suitable for downstream processing. Commercial precedents show that certain types of lignin (lignosulphonates) may be converted into vanillin and other marketable products, but new technologies are needed to enhance the lignin value chain. The complex, irregular structure of lignin complicates chemical conversion efforts, and known depolymerization methods typically afford ill-defined products in low yields (that is, less than 10-20wt%). Here we describe a method for the depolymerization of oxidized lignin under mild conditions in aqueous formic acid that results in more than 60wt% yield of low-molecular-mass aromatics. We present the discovery of this facile C-O cleavage method, its application to aspen lignin depolymerization, and mechanistic insights into the reaction. The broader implications of these results for lignin conversion and biomass refining are also considered.

  6. Perfluorooctanoic acid exposure triggers oxidative stress in the mouse pancreas

    Directory of Open Access Journals (Sweden)

    Lisa M. Kamendulis

    2014-01-01

    Full Text Available Perfluorooctanoic acid (PFOA is used in the manufacture of many industrial and commercial products. PFOA does not readily decompose in the environment, and is biologically persistent. Human epidemiologic and animal studies suggest that PFOA exposure elicits adverse effects on the pancreas. While multiple animal studies have examined PFOA-mediated toxicity in the liver, little is known about the potential adverse effects of PFOA on the pancreas. To address this, we treated C57Bl/6 mice with vehicle, or PFOA at doses of 0.5, 2.5 or 5.0 mg/kg BW/day for 7 days. Significant accumulation of PFOA was found in the serum, liver and pancreas of PFOA-treated animals. Histopathologic examination of the pancreas revealed focal ductal hyperplasia in mice treated with 2.5 and 5.0 mg/kg BW/day PFOA, while inflammation was observed only in the high dose group. Elevated serum levels of amylase and lipase were observed in the 2.5 mg/kg BW/day PFOA treatment group. In addition, PFOA exposure resulted in a dose-dependent increase in the level of the lipid peroxidation product 8-iso-PGF2α and induction of the antioxidant response genes Sod1, Sod2, Gpx2 and Nqo1. Our findings provide additional evidence that the pancreas is a target organ for PFOA-mediated toxicity and suggest that oxidative stress may be a mechanism through which PFOA induces histopathological changes in the pancreas.

  7. Phytanic acid alpha-oxidation: decarboxylation of 2-hydroxyphytanoyl-CoA to pristanic acid in human liver

    NARCIS (Netherlands)

    Verhoeven, N. M.; Wanders, R. J.; Schor, D. S.; Jansen, G. A.; Jakobs, C.

    1997-01-01

    The degradation of the first intermediate in the alpha-oxidation of phytanic acid, 2-hydroxyphytanoyl-CoA, was investigated. Human liver homogenates were incubated with 2-hydroxyphytanoyl-CoA or 2-hydroxyphytanic acid, after which formation of 2-ketophytanic acid and pristanic acid were studied.

  8. Extracorporeal membrane oxygenation promotes long chain fatty acid oxidation in the immature swine heart in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Kajimoto, Masaki; O' Kelly-Priddy, Colleen M.; Ledee, Dolena R.; Xu, Chun; Isern, Nancy G.; Olson, Aaron; Portman, Michael A.

    2013-09-01

    Extracorporeal membrane oxygenation (ECMO) supports infants and children with severe cardiopulmonary compromise. Nutritional support for these children includes provision of medium- and long-chain fatty acids (FAs). However, ECMO induces a stress response, which could limit the capacity for FA oxidation. Metabolic impairment could induce new or exacerbate existing myocardial dysfunction. Using a clinically relevant piglet model, we tested the hypothesis that ECMO maintains the myocardial capacity for FA oxidation and preserves myocardial energy state. Provision of 13-Carbon labeled medium-chain FA (octanoate), longchain free FAs (LCFAs), and lactate into systemic circulation showed that ECMO promoted relative increases in myocardial LCFA oxidation while inhibiting lactate oxidation. Loading of these labeled substrates at high dose into the left coronary artery demonstrated metabolic flexibility as the heart preferentially oxidized octanoate. ECMO preserved this octanoate metabolic response, but also promoted LCFA oxidation and inhibited lactate utilization. Rapid upregulation of pyruvate dehydrogenase kinase-4 (PDK4) protein appeared to participate in this metabolic shift during ECMO. ECMO also increased relative flux from lactate to alanine further supporting the role for pyruvate dehydrogenase inhibition by PDK4. High dose substrate loading during ECMO also elevated the myocardial energy state indexed by phosphocreatine to ATP ratio. ECMO promotes LCFA oxidation in immature hearts, while maintaining myocardial energy state. These data support the appropriateness of FA provision during ECMO support for the immature heart.

  9. Fatty acid oxidation changes and the correlation with oxidative stress in different preeclampsia-like mouse models.

    Directory of Open Access Journals (Sweden)

    Xiaoyan Ding

    Full Text Available BACKGROUND: Long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD expression is decreased in placenta of some cases of preeclampsia (PE which may result in free fatty acid (FFA increased. High FFA level will induce oxidative stress, so abnormal long-chain fatty acid-oxidation may participate in the pathogenesis of PE through oxidative stress pathway. METHODS: PE-like groups were ApoC3 transgenic mice with abnormal fatty acid metabolism, classical PE-like models with injection of Nw-nitro-L-arginine-methyl ester (L-NA or lipopolysaccharide (LPS and the antiphospholipid syndrome (APS mouse model with β2GPI injection (ApoC3+NS, ApoC3+L-NA, L-NA, LPS and β2GPI groups. The control group was wild-type mice with normal saline injection. Except for β2GPI mice, the other mice were subdivided into pre-implantation (Pre and mid-pregnancy (Mid subgroups by injection time. RESULTS: All PE-like groups showed hypertension and proteinuria except ApoC3+NS mice only showed hypertension. Serum FFA levels increased significantly except in LPS group compared to controls (P<0.05. LCHAD mRNA and protein expression in the liver and placenta was significantly higher for ApoC3+NS, ApoC3+L-NA and β2GPI mice and lower for L-NA mice than controls (P<0.05 but did not differ between LPS mice and controls. P47phox mRNA and protein expression in the liver significantly increased in all PE-like groups except LPS group, while P47phox expression in the placenta only significantly increased in L-NA and β2GPI groups. CONCLUSIONS: Abnormal long-chain fatty acid-oxidation may play a different role in different PE-like models and in some cases participate in the pathogenesis of PE through oxidative stress pathway.

  10. Storage-induced increase in biomarkers of oxidative stress and inflammation in red blood cell components

    DEFF Research Database (Denmark)

    Kücükakin, Bülent; Kocak, Volkan; Lykkesfeldt, Jens

    2011-01-01

    , respectively. The samples were analysed for various biomarkers expressing the oxidative stress and inflammation, including malondialdehyde (MDA), α-tocopherol (AT), dehydroascorbic acid (DHA), ascorbate (ASC), YKL-40 and interleukin-6 (IL-6). Results. The levels ofMDA, ASC, DHA, IL-6 and YKL-40 changed...... of 35 days except for AT. The data suggest a possible rationale behind the observation that aging blood products may increase the risk of complications following surgery and blood transfusion. Read More: http://informahealthcare.com/doi/abs/10.3109/00365513.2011.563789...

  11. Refractory Oxide Coatings on Titanium for Nitric Acid Applications

    Science.gov (United States)

    Ravi Shankar, A.; Kamachi Mudali, U.

    2014-07-01

    Tantalum and Niobium have good corrosion resistance in nitric acid as well as in molten chloride salt medium encountered in spent fuel nuclear reprocessing plants. Commercially, pure Ti (Cp-Ti) exhibits good corrosion resistance in nitric acid medium; however, in vapor condensates of nitric acid, significant corrosion was observed. In the present study, a thermochemical diffusion method was pursued to coat Ta2O5, Nb2O5, and Ta2O5 + Nb2O5 on Ti to improve the corrosion resistance and enhance the life of critical components in reprocessing plants. The coated samples were characterized by XRD, SEM, EDX, profilometry, micro-scratch test, and ASTM A262 Practice-C test in 65 pct boiling nitric acid. The SEM micrograph of the coated samples showed that uniform dense coating containing Ta2O5 and/or Nb2O5 was formed. XRD patterns indicated the formation of TiO2, Ta2O5/Nb2O5, and mixed oxide/solid solution phase on coated Ti samples. ASTM A262 Practice-C test revealed reproducible outstanding corrosion resistance of Ta2O5-coated sample in comparison to Nb2O5- and Ta2O5 + Nb2O5-coated sample. The hardness of the Ta2O5-coated Cp-Ti sample was found to be twice that of uncoated Cp-Ti. The SEM and XRD results confirmed the presence of protective oxide layer (Ta2O5, rutile TiO2, and mixed phase) on coated sample which improved the corrosion resistance remarkably in boiling liquid phase of nitric acid compared to uncoated Cp-Ti and Ti-5Ta-1.8Nb alloy. Three phase corrosion test conducted on Ta2O5-coated samples in boiling 11.5 M nitric acid showed poor corrosion resistance in vapor and condensate phases of nitric acid due to poor adhesion of the coating. The adhesive strength of the coated samples needs to be optimized in order to improve the corrosion resistance in vapor and condensate phases of nitric acid.

  12. Factors affecting the fatty acid composition and fat oxidative stability in pigs

    Directory of Open Access Journals (Sweden)

    Karel Vehovsky

    2015-03-01

    Full Text Available The aim of the study was to evaluate the effect of selected factors affecting fatty acids (FA composition in pig fat. In the experiment, the influence of nutrition, gender, carcass weight, lean meat proportion (LMP and intramuscular fat (IMF were monitored. The effect of diet, specifically the influence of added linseed or corn on the fatty acids composition in the backfat was studied in pigs. From the perspective of the required increase of polyunsaturated fatty acids (PUFA only the addition of the linseed proved to have a significant effect. Another evaluated aspect concerning the FA spectrum was the gender. While the backfat in barrows showed higher (P≤0.05 amount of monounsaturated fatty acids (MUFA, the backfat in gilts displayed a significantly higher proportion (P≤0.01 of the PUFA and total unsaturated fatty acids (UFA. A significant effect on the PUFA proportion has also been demonstrated for the lean meat proportion (LMP parameter, which therefore represents not only a qualitative carcass meat parameter but also plays an important role in relation to the FA composition in the fat in pigs. In connection to the FA proportion changes the study also monitored the fat oxidative stability with the use of the TBARS method. Concerning the oxidative stability the effects of nutrition, FA groups, gender, carcass weight and LMP were studied. The relationship between the above mentioned factors and oxidative stability was found to be insignificant.

  13. Increased FasL expression correlates with apoptotic changes in granulocytes cultured with oxidized clozapine.

    Science.gov (United States)

    Husain, Zaheed; Almeciga, Ingrid; Delgado, Julio C; Clavijo, Olga P; Castro, Januario E; Belalcazar, Viviana; Pinto, Clara; Zuñiga, Joaquin; Romero, Viviana; Yunis, Edmond J

    2006-08-01

    Clozapine has been associated with a 1% incidence of agranulocytosis. The formation of an oxidized intermediate clozapine metabolite has been implicated in direct polymorphonuclear (PMN) toxicity. We utilized two separate systems to analyze the role of oxidized clozapine in inducing apoptosis in treated cells. Human PMN cells incubated with clozapine (0-10 microM) in the presence of 0.1 mM H2O2 demonstrated a progressive decrease of surface CD16 expression along with increased apoptosis. RT-PCR analysis showed decreased CD16 but increased FasL gene expression in clozapine-treated PMN cells. No change in constitutive Fas expression was observed in treated cells. In HL-60 cells induced to differentiate with retinoic acid (RA), a similar increase in FasL expression, but no associated changes in CD16 gene expression, was observed following clozapine treatments. Our results demonstrate increased FasL gene expression in oxidized clozapine-induced apoptotic neutrophils suggesting that apoptosis in granulocytes treated with clozapine involves Fas/FasL interaction that initiates a cascade of events leading to clozapine-induced agranulocytosis.

  14. Manganese(II) catalyzes the bicarbonate-dependent oxidation of amino acids by hydrogen peroxide and the amino acid-facilitated dismutation of hydrogen peroxide.

    OpenAIRE

    Berlett, B S; Chock, P B; Yim, M B; Stadtman, E. R.

    1990-01-01

    In bicarbonate/CO2 buffer, Mn(II) and Fe(II) catalyze the oxidation of amino acids by H2O2 and the dismutation of H2O2. As the Mn(II)/Fe(II) ratio is increased, the yield of carbonyl compounds per mole of leucine oxidized is essentially constant, but the ratio of alpha-ketoisocaproate to isovaleraldehyde formed increases, and the fraction of H2O2 converted to O2 increases. In the absence of Fe(II), the rate of Mn(II)-catalyzed leucine oxidation is directly proportional to the H2O2, Mn(II), an...

  15. Protective effect of carvedilol on oxidative stress induced by okadaic acid in N1E-115 cells.

    Science.gov (United States)

    Túnez, Isaac; Collado, Juan A; Medina, Francisco J; Muñoz, M Carmen; Gordillo, Rafael; Sampedro, Concepción; Moyano, María J; Feijóo, Montserrat; Muntané, Jordi; Montilla, Pedro

    2006-09-01

    The effect of carvedilol on oxidative and cell damage induced by okadaic acid in N1E-115 cells were studied. The effects of okadaic acid were evaluated as changes in: the quantity of lipid peroxidation products, protein carbonyl groups, reduced glutathione content (GSH), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase and total lactate dehydrogenase (cell LDH). Additionally, a dose of carvedilol (10(-5)M) was added 2h before incubation with okadaic acid (50 nM) and was present until the end of the experiment (2h later added okadaic acid). Our results reveal that okadaic acid induces oxidative stress and an increase of cell LDH in N1E-115 cells, whereas carvedilol prevented the changes prompted by okadaic acid. In conclusion, the data show the protective effect of carvedilol, as well as its ability to modify cell response to okadaic acid, involving like cytoprotective mechanism its antioxidative properties.

  16. A chronic increase of corticosterone age-dependently reduces systemic DNA damage from oxidation in rats

    DEFF Research Database (Denmark)

    Jorgensen, Anders; Kalliokoski, Otto; Forsberg, Kristin

    2017-01-01

    differences. In old animals, CORT caused a borderline significant reduction of RNA oxidation in CNS, which was paralleled by a normalization of performance in an object location memory test. To our knowledge, this is the first demonstration that chronic stress-associated levels of CORT can reduce nucleic acid......Stress and depression are associated with an acceleration of brain and bodily aging; effects which have been attributed to chronic elevations of glucocorticoids. We tested the hypothesis that a three week administration of stress-associated levels of corticosterone (CORT, the principal rodent...... glucocorticoid) would increase systemic and CNS DNA and RNA damage from oxidation; a phenomenon known to be centrally involved in the aging process. We also hypothesized that older individuals would be more sensitive to this effect and that the chronic CORT administration would exacerbate age-related memory...

  17. Electro-oxidation of methanol and formic acid on platinum nanoparticles with different oxidation levels

    Energy Technology Data Exchange (ETDEWEB)

    Hsieh, Chien-Te, E-mail: cthsieh@saturn.yzu.edu.tw [Department of Chemical Engineering and Materials Science, Yuan Ze University, Taoyuan 320, Taiwan (China); Hsiao, Han-Tsung; Tzou, Dong-Ying; Yu, Po-Yuan [Department of Chemical Engineering and Materials Science, Yuan Ze University, Taoyuan 320, Taiwan (China); Chen, Po-Yen; Jang, Bi-Sheng [Materials and Electro-Optics Research Division, National Chung-Shan Institute of Science and Technology, Taoyuan 325, Taiwan (China)

    2015-01-15

    Herein reported is an atomic layer deposition (ALD) process of platinum (Pt) from (methylcyclopentadienyl) trimethylplatinum (MeCpPtMe{sub 3}) and oxygen (O{sub 2}) for synthesizing the Pt electrocatalysts toward methanol and formic acid oxidation. The as-synthesized Pt catalysts are thermally reduced in 5 vol% H{sub 2} within temperature window of 150–450 °C. The reduction treatment induces a decrease in amount of Pt oxide (Pt–O) species, e.g., PtO and PtO{sub 2}. The presence of Pt–O species not only enhances catalytic activity but also improves anti-poisoning ability toward the oxidation of methanol and formic acid. The improved activity originates from the fact that the Pt–O species, formed by the ALD route, creates a large number of active sites (e.g., Pt–O{sub ads} and Pt–(OH){sub ads}) to strip the CO-adsorbed sites, leading to a high-level of CO tolerance. This work also proposes a stepwise reaction steps to shed some lights on how the Pt–O species promote the catalytic activity. - Highlights: • This study adopts atomic layer deposition (ALD) to grow metallic Pt nanoparticles. • The Pt catalysts show catalytic activity toward methanol and formic acid oxidation. • The reduction treatment induces a decrease in amount of Pt oxide (Pt–O) species. • The Pt–O species creates a number of active sites to strip the CO-adsorbed sites. • A stepwise reaction step concerning the promoted catalytic activity is proposed.

  18. Effect of Dietary n-3 Polyunsaturated Fatty Acids on Oxidant/Antioxidant Status in Macrosomic Offspring of Diabetic Rats

    Directory of Open Access Journals (Sweden)

    B. Guermouche

    2014-01-01

    Full Text Available The aim of this work was to determine the effect of dietary n-3 PUFA on oxidant/antioxidant status, in vitro very low and low density lipoprotein (VLDL-LDL, and VLDL-LDL-fatty acid composition in macrosomic pups of diabetic mothers. We hypothesized that n-3 PUFA would improve oxidative stress in macrosomia. Diabetes was induced in female Wistar rats fed with the ISIO diet (control or with the EPAX diet (enriched in n-3 PUFAs, by streptozotocin. The macrosomic pups were killed at birth (day 0 and at adulthood (day 90. Lipid parameters and VLDL-LDL-fatty acid composition were investigated. The oxidant/antioxidant status was determined by measuring plasma oxygen radical absorbance capacity (ORAC, hydroperoxides, carbonyl proteins, and VLDL-LDL oxidation. Macrosomic rats of ISIO fed diabetic mothers showed an increase in plasma and VLDL-LDL-triglycerides and VLDL-LDL-cholesterol levels and altered VLDL-LDL-fatty acid composition. Plasma ORAC was low with high hydroperoxide and carbonyl protein levels. The in vitro oxidizability of VLDL-LDL was enhanced in these macrosomic rats. The EPAX diet corrected lipid parameters and improved oxidant/antioxidant status but increased VLDL-LDL susceptibility to oxidation. Macrosomia is associated with lipid abnormalities and oxidative stress. n-3 PUFA exerts favorable effects on lipid metabolism and on the oxidant/antioxidant status of macrosomic rats. However, there are no evident effects on VLDL-LDL oxidation.

  19. Changes in oxidative potential of soil and fly ash after reaction with gaseous nitric acid

    Science.gov (United States)

    Zhan, Ying; Ginder-Vogel, Matthew; Shafer, Martin M.; Rudich, Yinon; Pardo, Michal; Katra, Itzhak; Katoshevski, David; Schauer, James J.

    2018-01-01

    The goal of this study was to examine the impact of simulated atmospheric aging on the oxidative potential of inorganic aerosols comprised primarily of crustal materials. Four soil samples and one coal fly ash sample were artificially aged in the laboratory through exposure to the vapor from 15.8 M nitric acid solution for 24 h at room temperature. Native and acid-aged samples were analyzed with a cellular macrophage and acellular dithionthreitol assays to determine oxidative potential. Additionally, the samples were analyzed to determine the concentration of 50 elements, both total and the water-soluble fraction of these elements by Sector Field Inductively Coupled Plasma Mass Spectrometry (SF-ICMS) and crystalline mineral composition using X-ray Diffraction (XRD). The results show that reactions with gaseous nitric acid increase the water-soluble fraction of many elements, including calcium, iron, magnesium, zinc, and lead. The mineral composition analysis documented that calcium-rich minerals present in the soils (e.g., calcite) are converted into different chemical forms, such as calcium nitrate (Ca(NO3)2). The nitric acid aging process, which can occur in the atmosphere, leads to a 200-600% increase in oxidative potential, as measured by cellular and acellular assays. This laboratory study demonstrates that the toxic effects of aged versus freshly emitted atmospheric dust may be quite different. In addition, the results suggest that mineralogical analysis of atmospheric dust may be useful in understanding its degree of aging.

  20. Assays for urinary biomarkers of oxidatively damaged nucleic acids

    DEFF Research Database (Denmark)

    Weimann, Allan; Broedbaek, Kasper; Henriksen, Trine

    2012-01-01

    -linked immunosorbent assay). The major analytical challenge is specificity. The best combination of selectivity and speed of analysis can be obtained by liquid chromatography coupled with tandem mass spectrometric detection. This, however, is also the most demanding technique with regard to price, complexity...... and skills requirement. The available ELISA methods present considerable specificity problems and cannot be recommended at present. The oxidized nucleic acid metabolites in urine are assumed to originate from the DNA and RNA. However, direct evidence is not available. A possible contribution from...

  1. Defects in muscle branched-chain amino acid oxidation contribute to impaired lipid metabolism.

    Science.gov (United States)

    Lerin, Carles; Goldfine, Allison B; Boes, Tanner; Liu, Manway; Kasif, Simon; Dreyfuss, Jonathan M; De Sousa-Coelho, Ana Luisa; Daher, Grace; Manoli, Irini; Sysol, Justin R; Isganaitis, Elvira; Jessen, Niels; Goodyear, Laurie J; Beebe, Kirk; Gall, Walt; Venditti, Charles P; Patti, Mary-Elizabeth

    2016-10-01

    Plasma levels of branched-chain amino acids (BCAA) are consistently elevated in obesity and type 2 diabetes (T2D) and can also prospectively predict T2D. However, the role of BCAA in the pathogenesis of insulin resistance and T2D remains unclear. To identify pathways related to insulin resistance, we performed comprehensive gene expression and metabolomics analyses in skeletal muscle from 41 humans with normal glucose tolerance and 11 with T2D across a range of insulin sensitivity (SI, 0.49 to 14.28). We studied both cultured cells and mice heterozygous for the BCAA enzyme methylmalonyl-CoA mutase (Mut) and assessed the effects of altered BCAA flux on lipid and glucose homeostasis. Our data demonstrate perturbed BCAA metabolism and fatty acid oxidation in muscle from insulin resistant humans. Experimental alterations in BCAA flux in cultured cells similarly modulate fatty acid oxidation. Mut heterozygosity in mice alters muscle lipid metabolism in vivo, resulting in increased muscle triglyceride accumulation, increased plasma glucose, hyperinsulinemia, and increased body weight after high-fat feeding. Our data indicate that impaired muscle BCAA catabolism may contribute to the development of insulin resistance by perturbing both amino acid and fatty acid metabolism and suggest that targeting BCAA metabolism may hold promise for prevention or treatment of T2D.

  2. Evaluation of etanercept degradation under oxidative stress and potential protective effects of various amino acids.

    Science.gov (United States)

    Lim, Jun Yeul; Kim, Nam Ah; Lim, Dae Gon; Kim, Ki Hyun; Hada, Shavron; Jeong, Seong Hoon

    2015-08-15

    To evaluate the oxidative stability of proteins, a model protein, etanercept, was exposed to oxidative stress conditions using hydrogen peroxide. Various amino acids were also evaluated on their antioxidant effect. Transition temperature (Tm), secondary structural content, hydrodynamic size, and aggregation and fragmentation of etanercept in solution were assessed using dynamic light scattering (DLS), size exclusion chromatography (SEC), differential scanning calorimetry (DSC), and far-UV circular dichroism (CD). Sample solutions were stored at 4 °C, 20 °C, and 40 °C under oxidative stress. The DLS results exhibited a decrease in the Z-average and intensity peak size of etanercept during the storage, suggesting fragmentation issues rather than aggregation by oxidation. The SEC results exhibited an increase in fragmentation and a decrease in aggregation and monomer content. The monomer content remained higher in histidine than in other amino acids, followed by methionine. There were three Tm of etanercept that were selected as key parameters of conformational stability. Oxidized samples exhibited a significant decrease in Tm values, indicating decreased conformational stability. Methionine exhibited the highest values in Tm1, followed by histidine. The CD spectrum exhibited one unique negative peak of etanercept without amino acids, and changed with oxidation. Only methionine exhibited an enhancement of the stability. All four biophysical analyses results suggest that the histidine and methionine provide a protective effect in the protein solution against oxidative stress. However, histidine was effective as an antioxidant but methionine showed highly enhanced conformational and secondary structural stability. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Ab initio and kinetic modeling studies of formic acid oxidation

    DEFF Research Database (Denmark)

    Marshall, Paul; Glarborg, Peter

    2015-01-01

    A detailed chemical kinetic model for oxidation of formic acid (HOCHO) in flames has been developed, based on theoretical work and data from literature. Ab initio calculations were used to obtain rate coefficients for reactions of HOCHO with H, O, and HO2. Modeling predictions with the mechanism...... have been compared to the experimental results of de Wilde and van Tiggelen (1968) who measured the laminar burning velocities for HOCHO flames over a range of stoichiometries and dilution ratios. The modeling predictions are generally satisfactory. The governing reaction mechanisms are outlined based...... on calculations with the kinetic model. Formic acid is consumed mainly by reaction with OH, yielding OCHO, which dissociates rapidly to CO2 + H, and HOCO, which may dissociate to CO + OH or CO2 + H, or react with H, OH, or O2 to form more stable products. The branching fraction of the HOCHO + OH reaction, as well...

  4. Oxidized Fatty Acids as Inter-Kingdom Signaling Molecules

    Directory of Open Access Journals (Sweden)

    Carolina H. Pohl

    2014-01-01

    Full Text Available Oxylipins or oxidized fatty acids are a group of molecules found to play a role in signaling in many different cell types. These fatty acid derivatives have ancient evolutionary origins as signaling molecules and are ideal candidates for inter-kingdom communication. This review discusses examples of the ability of organisms from different kingdoms to “listen” and respond to oxylipin signals during interactions. The interactions that will be looked at are signaling between animals and plants; between animals and fungi; between animals and bacteria and between plants and fungi. This will aid in understanding these interactions, which often have implications in ecology, agriculture as well as human and animal health.

  5. Engineering Saccharomyces cerevisiae fatty acid composition for increased tolerance to octanoic acid.

    Science.gov (United States)

    Besada-Lombana, Pamela B; Fernandez-Moya, Ruben; Fenster, Jacob; Da Silva, Nancy A

    2017-07-01

    Biorenewable chemicals such as short and medium chain fatty acids enable functional or direct substitution of petroleum-derived building blocks, allowing reduction of anthropogenic greenhouse gases while meeting market needs of high-demand products like aliphatic alcohols and alpha olefins. However, producing these fatty acids in microorganisms can be challenging due to toxicity issues. Octanoic acid (C8) can disrupt the integrity of the cell membrane in yeast, and exogenous supplementation of oleic acid has been shown to help alleviate this. We recently engineered the Saccharomyces cerevisiae enzyme acetyl-CoA carboxylase by replacing serine residue 1157 with alanine to prevent deactivation by phosphorylation. Expression of Acc1 S1157A in S. cerevisiae resulted in an increase in total fatty acid production, with the largest increase for oleic acid. In this study, we evaluated the effect of this modified lipid profile on C8 toxicity to the yeast. Expression of Acc1 S1157A in S. cerevisiae BY4741 increased the percentage of oleic acid 3.1- and 1.6-fold in the absence and presence of octanoic acid challenge, respectively. Following exposure to 0.9 mM of C8 for 24 h, the engineered yeast had a 10-fold higher cell density relative to the baseline strain. Moreover, overexpressing Acc1 S1157A allowed survival at C8 concentrations that were lethal for the baseline strain. This marked reduction of toxicity was shown to be due to higher membrane integrity as an 11-fold decrease in leakage of intracellular magnesium was observed. Due to the increase in oleic acid, this approach has the potential to reduce toxicity of other valuable bioproducts such as shorter chain aliphatic acids and alcohols and other membrane stressors. In an initial screen, increased resistance to n-butanol, 2-propanol, and hexanoic acid was demonstrated with cell densities 3.2-, 1.8-, and 29-fold higher than the baseline strain, respectively. Biotechnol. Bioeng. 2017;114: 1531-1538. © 2017 Wiley

  6. Folic acid supplementation increases cutaneous vasodilator sensitivity to sympathetic nerve activity in older adults.

    Science.gov (United States)

    Stanhewicz, Anna E; Greaney, Jody L; Alexander, Lacy M; Kenney, W Larry

    2017-05-01

    During heat stress, blunted increases in skin sympathetic nervous system activity (SSNA) and reductions in end-organ vascular responsiveness contribute to the age-related reduction in reflex cutaneous vasodilation. In older adults, folic acid supplementation improves the cutaneous vascular conductance (CVC) response to passive heating; however, the influence of folic acid supplementation on SSNA:CVC transduction is unknown. Fourteen older adults (66 ± 1 yr, 8 male/6 female) ingested folic acid (5 mg/day) or placebo for 6 wk in a randomized, double-blind, crossover design. In protocol 1, esophageal temperature (Tes) was increased by 1.0°C (water-perfused suit) while SSNA (peroneal microneurography) and red cell flux in the innervated dermatome (laser Doppler flowmetry; dorsum of the foot) were continuously measured. In protocol 2, two intradermal microdialysis fibers were placed in the skin of the lateral calf for graded infusions of acetylcholine (ACh; 10(-10) to 10(-1) M) with and without nitric oxide synthase (NOS) blockade (20 mM nitro-l-arginine methyl ester). Folic acid improved reflex vasodilation (46 ± 4% vs. 31 ± 3% CVCmax for placebo; P Folic acid increased the slope of the SSNA-to-CVC relation (0.08 ± 0.02 vs. 0.05 ± 0.01 for placebo; P Folic acid augmented ACh-induced vasodilation (83 ± 3% vs. 66 ± 4% CVCmax for placebo; P = 0.002); however, there was no difference between treatments at the NOS-inhibited site (53 ± 4% vs. 52 ± 4% CVCmax for placebo; NS). These data demonstrate that folic acid supplementation enhances reflex vasodilation by increasing the sensitivity of skin arterioles to central sympathetic nerve outflow during hyperthermia in aged human subjects. Copyright © 2017 the American Physiological Society.

  7. Exercise Increases 24-h Fat Oxidation Only When It Is Performed Before Breakfast

    Directory of Open Access Journals (Sweden)

    Kaito Iwayama

    2015-12-01

    Interpretation: Under energy-balanced conditions, 24-h fat oxidation was increased by exercise only when performed before breakfast. Transient carbohydrate deficits, i.e., glycogen depletion, observed after morning exercise may have contributed to increased 24-h fat oxidation.

  8. Role of folic acid in nitric oxide bioavailability and vascular endothelial function.

    Science.gov (United States)

    Stanhewicz, Anna E; Kenney, W Larry

    2017-01-01

    Folic acid is a member of the B-vitamin family and is essential for amino acid metabolism. Adequate intake of folic acid is vital for metabolism, cellular homeostasis, and DNA synthesis. Since the initial discovery of folic acid in the 1940s, folate deficiency has been implicated in numerous disease states, primarily those associated with neural tube defects in utero and neurological degeneration later in life. However, in the past decade, epidemiological studies have identified an inverse relation between both folic acid intake and blood folate concentration and cardiovascular health. This association inspired a number of clinical studies that suggested that folic acid supplementation could reverse endothelial dysfunction in patients with cardiovascular disease (CVD). Recently, in vitro and in vivo studies have begun to elucidate the mechanism(s) through which folic acid improves vascular endothelial function. These studies, which are the focus of this review, suggest that folic acid and its active metabolite 5-methyl tetrahydrofolate improve nitric oxide (NO) bioavailability by increasing endothelial NO synthase coupling and NO production as well as by directly scavenging superoxide radicals. By improving NO bioavailability, folic acid may protect or improve endothelial function, thereby preventing or reversing the progression of CVD in those with overt disease or elevated CVD risk. © The Author(s) 2016. Published by Oxford University Press on behalf of the International Life Sciences Institute. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  9. Bronchoconstriction induced by citric acid inhalation in guinea pigs: role of tachykinins, bradykinin, and nitric oxide.

    Science.gov (United States)

    Ricciardolo, F L; Rado, V; Fabbri, L M; Sterk, P J; Di Maria, G U; Geppetti, P

    1999-02-01

    Gastroesophageal acid reflux into the airways can trigger asthma attacks. Indeed, citric acid inhalation causes bronchoconstriction in guinea pigs, but the mechanism of this effect has not been fully clarified. We investigated the role of tachykinins, bradykinin, and nitric oxide (NO) on the citric acid- induced bronchoconstriction in anesthetized and artificially ventilated guinea pigs. Citric acid inhalation (2-20 breaths) caused a dose-dependent increase in total pulmonary resistance (RL). RL value obtained after 10 breaths of citric acid inhalation was not significantly different from the value obtained after 20 breaths (p = 0.22). The effect produced by a half-submaximum dose of citric acid (5 breaths) was halved by the bradykinin B2 receptor antagonist HOE 140 (0.1 micromol x kg-1, intravenous) and abolished by the tachykinin NK2 receptor antagonist SR 48968 (0.3 micromol x kg-1, intravenous). Bronchoconstriction induced by a submaximum dose of citric acid (10 breaths) was partially reduced by the administration of HOE 140, SR 48968, or the NK1 receptor antagonist CP-99,994 (8 micromol x kg-1, intravenous) alone and completely abolished by the combination of SR 48968 and CP-99,994. Pretreatment with the NO synthase inhibitor, L-NMMA (1 mM, 10 breaths every 5 min for 30 min) increased in an L-arginine-dependent manner the effect of citric acid inhalation on RL. HOE 140 and CP-99,994 markedly reduced the L-NMMA-potentiated bronchoconstriction to inhaled citric acid. We conclude that citric acid-induced bronchoconstriction is caused by tachykinin release from sensory nerves, which, in part, is mediated by endogenously released bradykinin. Simultaneous release of NO by citric acid inhalation counteracts tachykinin-mediated bronchoconstriction. Our study suggests a possible implication of these mechanisms in asthma associated with gastroesophageal acid reflux and a potential therapeutic role of tachykinin and bradykinin antagonists.

  10. Hypochlorous acid-mediated protein oxidation: how important are chloramine transfer reactions and protein tertiary structure?

    Science.gov (United States)

    Pattison, David I; Hawkins, Clare L; Davies, Michael J

    2007-08-28

    Hypochlorous acid (HOCl) is a powerful oxidant generated from H2O2 and Cl- by the heme enzyme myeloperoxidase, which is released from activated leukocytes. HOCl possesses potent antibacterial properties, but excessive production can lead to host tissue damage that occurs in numerous human pathologies. As proteins and amino acids are highly abundant in vivo and react rapidly with HOCl, they are likely to be major targets for HOCl. In this study, two small globular proteins, lysozyme and insulin, have been oxidized with increasing excesses of HOCl to determine whether the pattern of HOCl-mediated amino acid consumption is consistent with reported kinetic data for isolated amino acids and model compounds. Identical experiments have been carried out with mixtures of N-acetyl amino acids (to prevent reaction at the alpha-amino groups) that mimic the protein composition to examine the role of protein structure on reactivity. The results indicate that tertiary structure facilitates secondary chlorine transfer reactions of chloramines formed on His and Lys side chains. In light of these data, second-order rate constants for reactions of Lys side chain and Gly chloramines with Trp side chains and disulfide bonds have been determined, together with those for further oxidation of Met sulfoxide by HOCl and His side chain chloramines. Computational kinetic models incorporating these additional rate constants closely predict the experimentally observed amino acid consumption. These studies provide insight into the roles of chloramine formation and three-dimensional structure on the reactions of HOCl with isolated proteins and demonstrate that kinetic models can predict the outcome of HOCl-mediated protein oxidation.

  11. Kinetics and mechanism of the oxidation of some α-hydroxy acids by ...

    Indian Academy of Sciences (India)

    Unknown

    2004-11-08

    Nov 8, 2004 ... Abstract. The oxidation of lactic acid, mandelic acid and ten monosubstituted mandelic acids by hexa- methylenetetramine-bromine (HABR) in glacial acetic acid, leads to the formation of the corresponding oxoacid. The reaction is first order with respect to each of the hydroxy acids and HABR. It is proposed.

  12. Anodic luminescence, structural, photoluminescent, and photocatalytic properties of anodic oxide films grown on niobium in phosphoric acid

    Energy Technology Data Exchange (ETDEWEB)

    Stojadinović, Stevan, E-mail: sstevan@ff.bg.ac.rs [University of Belgrade, Faculty of Physics, Studentski trg 12-16, 11000 Belgrade (Serbia); Tadić, Nenad [University of Belgrade, Faculty of Physics, Studentski trg 12-16, 11000 Belgrade (Serbia); Radić, Nenad [University of Belgrade, Institute of Chemistry, Technology and Metallurgy, Department of Catalysis and Chemical Engineering, Njegoševa 12, 11000 Belgrade (Serbia); Stefanov, Plamen [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Block 11, 1113 Sofia (Bulgaria); Grbić, Boško [University of Belgrade, Institute of Chemistry, Technology and Metallurgy, Department of Catalysis and Chemical Engineering, Njegoševa 12, 11000 Belgrade (Serbia); Vasilić, Rastko [University of Belgrade, Faculty of Physics, Studentski trg 12-16, 11000 Belgrade (Serbia)

    2015-11-15

    Graphical abstract: - Highlights: • Anodic luminescence is correlated to the existence of morphological defects in the oxide. • Spectrum under spark discharging reveals only oxygen and hydrogen lines. • Oxide films formed under spark discharging are crystallized and composed of Nb{sub 2}O{sub 5}. • Photocatalytic activity and photoluminescence of Nb{sub 2}O{sub 5} films increase with time. - Abstract: This article reports on properties of oxide films obtained by anodization of niobium in phosphoric acid before and after the dielectric breakdown. Weak anodic luminescence of barrier oxide films formed during the anodization of niobium is correlated to the existence of morphological defects in the oxide layer. Small sized sparks generated by dielectric breakdown of formed oxide film cause rapid increase of luminescence intensity. The luminescence spectrum of obtained films on niobium under spark discharging is composed of continuum radiation and spectral lines caused by electronic spark discharging transitions in oxygen and hydrogen atoms. Oxide films formed before the breakdown are amorphous, while after the breakdown oxide films are partly crystalline and mainly composed of Nb{sub 2}O{sub 5} hexagonal phase. The photocatalytic activity of obtained oxide films after the breakdown was investigated by monitoring the degradation of methyl orange. Increase of the photocatalytic activity with time is related to an increase of oxygen vacancy defects in oxide films formed during the process. Also, higher concentration of oxygen vacancy defects in oxide films results in higher photoluminescence intensity.

  13. Ruthenium-catalyzed aerobic oxidative decarboxylation of amino acids: a green, zero-waste route to biobased nitriles.

    Science.gov (United States)

    Claes, Laurens; Verduyckt, Jasper; Stassen, Ivo; Lagrain, Bert; De Vos, Dirk E

    2015-04-18

    Oxidative decarboxylation of amino acids into nitriles was performed using molecular oxygen as terminal oxidant and a heterogeneous ruthenium hydroxide-based catalyst. A range of amino acids was oxidized in very good yield, using water as the solvent.

  14. Chlorogenic acid ameliorates endotoxin-induced liver injury by promoting mitochondrial oxidative phosphorylation

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yan [State Key Laboratory of Food Science and Technology and School of Food Science, Nanchang University, Nanchang 330047 (China); College of Food Safety, Guizhou Medical University, Guiyang 550025 (China); Ruan, Zheng, E-mail: ruanzheng@ncu.edu.cn [State Key Laboratory of Food Science and Technology and School of Food Science, Nanchang University, Nanchang 330047 (China); Zhou, Lili; Shu, Xugang [State Key Laboratory of Food Science and Technology and School of Food Science, Nanchang University, Nanchang 330047 (China); Sun, Xiaohong [College of Food Safety, Guizhou Medical University, Guiyang 550025 (China); Mi, Shumei; Yang, Yuhui [State Key Laboratory of Food Science and Technology and School of Food Science, Nanchang University, Nanchang 330047 (China); Yin, Yulong, E-mail: yinyulong@isa.ac.cn [State Key Laboratory of Food Science and Technology and School of Food Science, Nanchang University, Nanchang 330047 (China); Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125 (China)

    2016-01-22

    Acute or chronic hepatic injury is a common pathology worldwide. Mitochondrial dysfunction and the depletion of adenosine triphosphate (ATP) play important roles in liver injury. Chlorogenic acids (CGA) are some of the most abundant phenolic acids in human diet. This study was designed to test the hypothesis that CGA may protect against chronic lipopolysaccharide (LPS)-induced liver injury by modulating mitochondrial energy generation. CGA decreased the activities of serum alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase. The contents of ATP and adenosine monophosphate (AMP), as well as the ratio of AMP/ATP, were increased after CGA supplementation. The activities of enzymes that are involved in glycolysis were reduced, while those of enzymes involved in oxidative phosphorylation were increased. Moreover, phosphorylated AMP-activated protein kinase (AMPK), and mRNA levels of AMPK-α, peroxisome proliferator-activated receptor-gamma coactivator 1α (PGC-1α), nuclear respiratory factor 1, and mitochondrial DNA transcription factor A were increased after CGA supplementation. Collectively, these findings suggest that the hepatoprotective effect of CGA might be associated with enhanced ATP production, the stimulation of mitochondrial oxidative phosphorylation and the inhibition of glycolysis. - Highlights: • Dietary supplementation with chlorogenic acid (CGA) improved endotoxin-induced liver injury. • Chlorogenic acid enhances ATP increase and shifts energy metabolism, which is correlated with up-regulation AMPK and PGC-1α. • The possible mechanism of CGA on mitochondrial biogenesis was correlated with up-regulation AMPK and PGC-1α.

  15. Trans fatty acids induce vascular inflammation and reduce vascular nitric oxide production in endothelial cells.

    Directory of Open Access Journals (Sweden)

    Naomi G Iwata

    Full Text Available Intake of trans fatty acids (TFA, which are consumed by eating foods made from partially hydrogenated vegetable oils, is associated with a higher risk of cardiovascular disease. This relation can be explained by many factors including TFA's negative effect on endothelial function and reduced nitric oxide (NO bioavailability. In this study we investigated the effects of three different TFA (2 common isomers of C18 found in partially hydrogenated vegetable oil and a C18 isomer found from ruminant-derived-dairy products and meat on endothelial NF-κB activation and nitric oxide (NO production. Human endothelial cells were treated with increasing concentrations of Elaidic (trans-C18:1 (9 trans, Linoelaidic (trans-C18:2 (9 trans, 12 trans, and Transvaccenic (trans-C18:1 (11 trans for 3 h. Both Elaidic and Linoelaidic acids were associated with increasing NF-κB activation as measured by IL-6 levels and phosphorylation of IκBα, and impairment of endothelial insulin signaling and NO production, whereas Transvaccenic acid was not associated with these responses. We also measured superoxide production, which has been hypothesized to be necessary in fatty acid-dependent activation of NF-κB. Both Elaidic acid and Linoelaidic acid are associated with increased superoxide production, whereas Transvaccenic acid (which did not induce inflammatory responses did not increase superoxide production. We observed differential activation of endothelial superoxide production, NF-κB activation, and reduction in NO production by different C18 isomers suggesting that the location and number of trans double bonds effect endothelial NF-κB activation.

  16. Lewis acid catalysis and Green oxidations: sequential tandem oxidation processes induced by Mn-hyperaccumulating plants.

    Science.gov (United States)

    Escande, Vincent; Renard, Brice-Loïc; Grison, Claude

    2015-04-01

    Among the phytotechnologies used for the reclamation of degraded mining sites, phytoextraction aims to diminish the concentration of polluting elements in contaminated soils. However, the biomass resulting from the phytoextraction processes (highly enriched in polluting elements) is too often considered as a problematic waste. The manganese-enriched biomass derived from native Mn-hyperaccumulating plants of New Caledonia was presented here as a valuable source of metallic elements of high interest in chemical catalysis. The preparation of the catalyst Eco-Mn1 and reagent Eco-Mn2 derived from Grevillea exul exul and Grevillea exul rubiginosa was investigated. Their unusual polymetallic compositions allowed to explore new reactivity of low oxidative state of manganese-Mn(II) for Eco-Mn1 and Mn(IV) for Eco-Mn2. Eco-Mn1 was used as a Lewis acid to catalyze the acetalization/elimination of aldehydes into enol ethers with high yields; a new green and stereoselective synthesis of (-)-isopulegol via the carbonyl-ene cyclization of (+)-citronellal was also performed with Eco-Mn1. Eco-Mn2 was used as a mild oxidative reagent and controlled the oxidation of aliphatic alcohols into aldehydes with quantitative yields. Oxidative cleavage was interestingly noticed when Eco-Mn2 was used in the presence of a polyol. Eco-Mn2 allowed direct oxidative iodination of ketones without using iodine, which is strongly discouraged by new environmental legislations. Finally, the combination of the properties in the Eco-Mn catalysts and reagents gave them an unprecedented potential to perform sequential tandem oxidation processes through new green syntheses of p-cymene from (-)-isopulegol and (+)-citronellal; and a new green synthesis of functionalized pyridines by in situ oxidation of 1,4-dihydropyridines.

  17. Acetic acid upregulates the expression of genes for fatty acid oxidation enzymes in liver to suppress body fat accumulation.

    Science.gov (United States)

    Kondo, Tomoo; Kishi, Mikiya; Fushimi, Takashi; Kaga, Takayuki

    2009-07-08

    We investigated the effect of acetic acid (AcOH) on the prevention of obesity in high-fat-fed mice. The mice were intragastrically administrated with water or 0.3 or 1.5% AcOH for 6 weeks. AcOH administration inhibited the accumulation of body fat and hepatic lipids without changing food consumption or skeletal muscle weight. Significant increases were observed in the expressions of genes for peroxisome-proliferator-activated receptor alpha (PPARalpha) and for fatty-acid-oxidation- and thermogenesis-related proteins: acetyl-CoA oxidase (ACO), carnitine palmitoyl transferase-1 (CPT-1), and uncoupling protein-2 (UCP-2), in the liver of the AcOH-treatment groups. PPARalpha, ACO, CPT-1, and UCP-2 gene expressions were increased in vitro by acetate addition to HepG2 cells. However, the effects were not observed in cells depleted of alpha2 5'-AMP-activated protein kinase (AMPK) by siRNA. In conclusion, AcOH suppresses accumulation of body fat and liver lipids by upregulation of genes for PPARalpha and fatty-acid-oxidation-related proteins by alpha2 AMPK mediation in the liver.

  18. Extraction of uranium from tailings by sulfuric acid leaching with oxidants

    Science.gov (United States)

    Huang, Jing; Li, Mi; Zhang, Xiaowen; Huang, Chunmei; Wu, Xiaoyan

    2017-06-01

    Recovery of uranium have been performed by leaching uranium-containing tailings in sulfuric acid system with the assistance of HF, HClO4, H2O2 and MnO2. The effect of reagent dosage, sulfuric acid concentration, Liquid/solid ratio, reaction temperature and particle size on the leaching of uranium were investigated. The results show that addiction of HF, HClO4, H2O2 and MnO2 significantly increased the extraction of uranium under 1M sulphuric acid condition and under the optimum reaction conditions a dissolution fraction of 85% by HClO4, 90% by HF, 95% by H2O2 can be reached respectively. The variation of technological mineralogy properites of tailings during leaching process show that the assistants can break gangue effectively. These observations suggest that optimum oxidants could potentially influence the extraction of uranium from tailings even under dilute acid condition.

  19. Protective effect of vitamin E on sperm motility and oxidative stress in valproic acid treated rats.

    Science.gov (United States)

    Ourique, Giovana M; Saccol, Etiane M H; Pês, Tanise S; Glanzner, Werner G; Schiefelbein, Sun Hee; Woehl, Viviane M; Baldisserotto, Bernardo; Pavanato, Maria A; Gonçalves, Paulo B D; Barreto, Kátia P

    2016-09-01

    Long-term administration of valproic acid (VPA) is known to promote reproductive impairment mediated by increase in testicular oxidative stress. Vitamin E (VitE) is a lipophilic antioxidant known to be essential for mammalian spermatogenesis. However, the capacity of this vitamin to abrogate the VPA-mediated oxidative stress has not yet been assessed. In the current study, we evaluated the protective effect of VitE on functional abnormalities related to VPA-induced oxidative stress in the male reproductive system. VPA (400 mg kg(-1)) was administered by gavage and VitE (50 mg kg(-1)) intraperitoneally to male Wistar rats for 28 days. Analysis of spermatozoa from the cauda epididymides was performed. The testes and epididymides were collected for measurement of oxidative stress biomarkers. Treatment with VPA induced a decrease in sperm motility accompanied by an increase in oxidative damage to lipids and proteins, depletion of reduced glutathione and a decrease in total reactive antioxidant potential on testes and epididymides. Co-administration of VitE restored the antioxidant potential and prevented oxidative damage on testes and epididymides, restoring sperm motility. Thus, VitE protects the reproductive system from the VPA-induced damage, suggesting that it may be a useful compound to minimize the reproductive impairment in patients requiring long-term treatment with VPA. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Photoassisted dissolution of a colloidal manganese oxide in the presence of fulvic acid

    Energy Technology Data Exchange (ETDEWEB)

    Walte, T.D.; Wrigley, I.C.; Szymczak, R.

    1988-07-01

    The dissolution of a synthesized manganese dioxide by a well-characterized fulvic acid has been investigated over a range of reactant concentrations, pH, and illumination conditions, as have components of the overall dissolution process including fulvic acid and manganous ion adsorption to the oxide surface. The dissolution process is satisfactorily described by an initial rapid formation of a surface-located precursor complex followed by a slower intramolecular electron-transfer step resulting in Mn(II) formation at the oxide surface. Illumination by 365-nm light enhances the rate of electron transfer significantly, with an increase in first-order reduction rate constant from 0.31 min/sup -1/ (dark) to 0.55 min/sup -1/ (light at pH 4.00 and from 0.53 min/sup -1/ (dark) to 1.23 min/sup -1/ (light) at pH 7.10. Depending on the affinity of the oxide surface for manganous ion, a portion of the Mn(II) produced at the oxide surface will be rapidly released to solution, resulting in dissolution of the oxide.

  1. Metformin suppresses lipid accumulation in skeletal muscle by promoting fatty acid oxidation.

    Science.gov (United States)

    Wang, Chao; Liu, Fang; Yuan, Yuan; Wu, Jie; Wang, Hui; Zhang, Lijun; Hu, Peizhen; Li, Zengshan; Li, Qing; Ye, Jing

    2014-01-01

    Obesity is a major risk factor for metabolic syndrome, including insulin resistance (IR), type 2 diabetes mellitus (T2DM), and cardiovascular disease; ectopic fat deposition plays a key role in the development of these conditions. In insulin-resistant and/or T2DM patients, lipid accumulation is increased in skeletal muscle; the intramuscular accumulation of fatty acid metabolites is recognized to play a critical role in metabolic syndrome. Besides improving insulin sensitivity, the anti-diabetic drug metformin can reduce lipid accumulation in skeletal muscle; however, its mechanism of action remains unclear. Ob/ob mice and C2C12 cells were used to explore the effects of metformin on the morphological and physiological changes of lipid droplets. To clarify the mechanism by which metformin regulates fatty acid metabolism, a cDNA microarray and quantitative real-time PCR were used to examine the effects of metformin on the transcriptome of C2C12 cells treated with 200 micromol/L oleic acid. Metformin could retard body weight gain, improve insulin sensitivity and reduce intramyocellular lipid accumulation in ob/ob mice. In C2C12 cells, metformin inhibited lipid accumulation, stimulated fatty acid oxidation, and decreased triglyceride synthesis. Twenty-seven differentially expressed genes, including 12 upregulated and 15 downregulated genes, were involved in fatty acid metabolism. Interestingly, several genes involved in acyl-CoA synthesis and fatty acid oxidation were also upregulated, such as Ppard, Acsbg1, Ascl3, and Mlycd. However, several genes related to lipolysis were downregulated, such as Ces1d and Cel. Moreover, several important genes related to lipid metabolism were also downregulated, such as Fabp4, Adipoq, and Apoc2. Metformin retards body weight gain, improves insulin sensitivity, and suppresses lipid accumulation in skeletal muscle by promoting fatty acid oxidation.

  2. Effect of boric acid on oxidative stress in rats with fetal alcohol syndrome.

    Science.gov (United States)

    Sogut, Ibrahim; Oglakci, Aysegul; Kartkaya, Kazim; Ol, Kevser Kusat; Sogut, Melis Savasan; Kanbak, Gungor; Inal, Mine Erden

    2015-03-01

    To the best of our knowledge, this is the first study concerning the effect of boric acid (BA) administration on fetal alcohol syndrome (FAS). In this study, the aim was to investigate prenatal alcohol-induced oxidative stress on the cerebral cortex of newborn rat pups and assess the protective and beneficial effects of BA supplementation on rats with FAS. Pregnant rats were divided into three groups, namely the control, alcohol and alcohol + boric acid groups. As markers of alcohol-induced oxidative stress in the cerebral cortex of the newborn pups, malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) levels were measured. Although the MDA levels in the alcohol group were significantly increased compared with those in the control group (Pboric acid group was shown to be significantly decreased compared with that in the alcohol group (Pboric acid group was significantly higher than that in the alcohol group (P<0.05). The GPx activity in the alcohol group was decreased compared with that in the control group (P<0.05). These results demonstrate that alcohol is capable of triggering damage to membranes of the cerebral cortex of rat pups and BA could be influential in antioxidant mechanisms against oxidative stress resulting from prenatal alcohol exposure.

  3. Oxidized LDL activates phospholipase A2 to supply fatty acids required for cholesterol esterification.

    Science.gov (United States)

    Akiba, Satoshi; Yoneda, Yukimasa; Ohno, Satoshi; Nemoto, Megumi; Sato, Takashi

    2003-09-01

    We examined the roles of phospholipase A2 (PLA2) in oxidized LDL (oxLDL)-induced cholesteryl ester formation in macrophages. In [3H]oleic acid-labeled RAW264.7 cells and mouse peritoneal macrophages, oxLDL induced [3H]cholesteryl oleate formation with an increase in free [3H]oleic acid and a decrease in [3H]phosphatidylcholine. The changes in these lipids were suppressed by methyl arachidonyl fluorophosphonate (MAFP), a cytosolic PLA2 (cPLA2) inhibitor. However, MAFP had no effect on the ACAT activity or the binding and/or uptake of oxLDL. Stimulation with oxLDL in the presence of [3H]cholesterol increased [3H]cholesteryl ester bearing fatty acyl chains derived from cellular and/or exogenous (oxLDL) lipids. The formation of cholesteryl ester under this condition was also inhibited by MAFP, and the inhibitory effect was reversed by adding oleic acid. While oxLDL did not affect the activity or amounts of cPLA2, preincubation with oxLDL enhanced the release of oleic acid and arachidonic acid induced by ionomycin in RAW264.7 cells. 13(S)-hydroxyoctadecadienoic acid, but not 7-ketocholesterol, also enhanced ionomycin-induced oleic acid release. These results suggest that oxLDL induces cPLA2 activation, which contributes, at least in part, to the supply of fatty acids required for the cholesteryl esterification, probably through the acceleration by oxidized lipids of the catalytic action of cPLA2 in macrophages.

  4. Activation of Secretagogue Independent Gastric Acid Secretion via Endothelial Nitric Oxide Synthase Stimulation in Rats

    Directory of Open Access Journals (Sweden)

    Alice Miriam Kitay

    2017-12-01

    Full Text Available Background/Aims: L-arginine is an important mediator of cell division, wound healing, and immune function. It can be transformed by the nitric oxide synthase (NOS to nitric oxide (NO, an important cell signaling molecule. Recent studies from our laboratory demonstrate specific effects of L-arginine (10mM exposure on gastric acid secretion in rat parietal cells. Methods: Studies were performed with isolated gastric glands and the pH sensitive dye BCECF-AM +/- L-arginine to examine its effects on acid secretion. The direct NO-donor diethylamine NONOate sodium salt hydrate, was also used while monitoring intracellular pH. The specific inhibitor of the intracellular NO signal cascade ODQ was also used. Results: We found that gastric proton extrusion was activated with application of L-arginine (10mM, in a separate series when L-arginine (10mM + L-NAME (30µM were added there was no acid secretion. Addition of the NO-donor diethylamine NONOate sodium salt hydrate (10µM also induced acid secretion. When the selective sGC-inhibitor ODQ was added with NONOate we did not observe acid secretion. Conclusion: We conclude that L-arginine is a novel secretagogue, which can mediate gastric acid secretion. Furthermore, the intake of L-arginine causes direct activation of the H+, K+ ATPase and increased proton extrusion from parietal cells resulting in the increased risk for acid-related diseases. The NO/sGC/cGMP pathway has never been described as a possible intracellular mechanism for H+, K+ ATPase activation before and presents a completely new scientific finding. Moreover, our studies demonstrate a novel role for L-NAME to effectively eliminate NOS induced acid secretion and thereby reducing the risk for L-arginine inducible ulcer disease.

  5. Neuroprotective effects of butterbur and rough aster against kainic Acid-induced oxidative stress in mice.

    Science.gov (United States)

    Oh, Sang Hee; Sok, Dai-Eun; Kim, Mee Ree

    2005-01-01

    The separate and combined neuroprotective effects of rough aster (Aster scaber) and butterbur (Petasite japonicus) extracts against oxidative damage in the brain of mice challenged with kainic acid were examined by comparing behavioral changes and biochemical parameters of oxidative stress. Rough aster butanol extract (400 mg/kg) and/or butterbur butanol extract (150 or 400 mg/kg) were administered to male ICR mice, 6-8 weeks old, through a gavage for 4 days consecutively, and on day 4, kainic acid (50 mg/kg) was administered intraperitoneally. Compared with the vehicle-treated control, no significant changes in body and brain weight were observed in mice administered rough aster or butterbur butanol extract. Administration of kainic acid only, causing a lethality of approximately 54%, resulted in a significant decrease of total glutathione level and increase of thiobarbituric acid-reactive substances (TBARS) value in brain tissue. The administration of butterbur or rough aster extract (400 mg/kg) decreased the lethality (50%) of kainic acid to 25%, alleviated the behavioral signs of neurotoxicity, restored the cytosolic glutathione level of brain homogenate to approximately 80% (P butterbur extract at a low dose (150 mg/kg), the combination of rough aster extract and butterbur extract reduced the lethality to 12.5%. Moreover, the combination delayed the onset time of behavioral signs by twofold, and significantly preserved the level of cytosolic glutathione peroxidase and glutathione reductase activities. However, the other biochemical parameters were not altered significantly by the combination. Thus, the combination of two vegetable extracts significantly increased the neuroprotective action against kainic acid-induced neurotoxicity. Based on these findings, the combination of butterbur extract and rough aster extract contains a functional agent or agents that protect against oxidative stress in the brain of mice.

  6. Systemic oxidative DNA and RNA damage are not increased during early phases of psychosis: A case control study.

    Science.gov (United States)

    Nordholm, Dorte; Poulsen, Henrik Enghusen; Hjorthøj, Carsten; Randers, Lasse; Nielsen, Mette Ø; Wulff, Sanne; Krakauer, Kristine; Nørbak-Emig, Henrik; Henriksen, Trine; Glenthøj, Birte; Nordentoft, Merete

    2016-07-30

    It has been suggested that patients with schizophrenia develop higher levels of oxidative stress, which may contribute to deteriorating mental illness. In order to examine oxidative stress in the early stages of severe mental illness, we examined the levels of systemic Deoxyribonucleic Acid (DNA) and Ribonucleic Acid (RNA) oxidation, 8-oxo-7,8-dihydro-2'-deoxyguanosine and 8-oxo-7,8-dihydroguanosine, perceived stress and recent life events in patients at ultra high-risk (UHR) of developing psychosis, in antipsychotic naïve patients with first-episode schizophrenia (FES), and in healthy controls. We included 41 UHR patients, 35 FES patients, and 29 healthy controls. There was no difference in the level of DNA/RNA oxidative damage between UHR patients and FES patients compared with healthy controls. We found no association between levels of DNA/RNA oxidative damage and perceived stress/life events. Based on the results, we suggest that DNA and RNA oxidative markers are not increased during the early stages of illness, but further longitudinal studies in first-episode psychosis should be carried out to examine whether DNA and RNA oxidative damage are potential markers of severe illness. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  7. Extremely rapid increase in fatty acid transport and intramyocellular lipid accumulation but markedly delayed insulin resistance after high fat feeding in rats.

    Science.gov (United States)

    Bonen, Arend; Jain, Swati S; Snook, Laelie A; Han, Xiao-Xia; Yoshida, Yuko; Buddo, Kathryn H; Lally, James S; Pask, Elizabeth D; Paglialunga, Sabina; Beaudoin, Marie-Soleil; Glatz, Jan F C; Luiken, Joost J F P; Harasim, Ewa; Wright, David C; Chabowski, Adrian; Holloway, Graham P

    2015-10-01

    The mechanisms for diet-induced intramyocellular lipid accumulation and its association with insulin resistance remain contentious. In a detailed time-course study in rats, we examined whether a high-fat diet increased intramyocellular lipid accumulation via alterations in fatty acid translocase (FAT/CD36)-mediated fatty acid transport, selected enzymes and/or fatty acid oxidation, and whether intramyocellular lipid accretion coincided with the onset of insulin resistance. We measured, daily (on days 1-7) and/or weekly (for 6 weeks), the diet-induced changes in circulating substrates, insulin, sarcolemmal substrate transporters and transport, selected enzymes, intramyocellular lipids, mitochondrial fatty acid oxidation and basal and insulin-stimulated sarcolemmal GLUT4 and glucose transport. We also examined whether upregulating fatty acid oxidation improved glucose transport in insulin-resistant muscles. Finally, in Cd36-knockout mice, we examined the role of FAT/CD36 in intramyocellular lipid accumulation, insulin sensitivity and diet-induced glucose intolerance. Within 2-3 days, diet-induced increases occurred in insulin, sarcolemmal FAT/CD36 (but not fatty acid binding protein [FABPpm] or fatty acid transporter [FATP]1 or 4), fatty acid transport and intramyocellular triacylglycerol, diacylglycerol and ceramide, independent of enzymatic changes or muscle fatty acid oxidation. Diet-induced increases in mitochondria and mitochondrial fatty acid oxidation and impairments in insulin-stimulated glucose transport and GLUT4 translocation occurred much later (≥21 days). FAT/CD36 ablation impaired insulin-stimulated fatty acid transport and lipid accumulation, improved insulin sensitivity and prevented diet-induced glucose intolerance. Increasing fatty acid oxidation in insulin-resistant muscles improved glucose transport. High-fat feeding rapidly increases intramyocellular lipids (in 2-3 days) via insulin-mediated upregulation of sarcolemmal FAT/CD36 and fatty acid

  8. Increased quinolinic acid in peripheral mononuclear cells in Alzheimer's dementia.

    Science.gov (United States)

    Busse, Mandy; Hettler, Vanessa; Fischer, Victoria; Mawrin, Christian; Hartig, Roland; Dobrowolny, Henrik; Bogerts, Bernhard; Frodl, Thomas; Busse, Stefan

    2017-04-06

    The role of monocytes and macrophages in the pathogenesis of neurodegenerative disorders such as Alzheimer's disease (AD) is poorly understood. Recently, we have shown that the number of CD14+ monocytes remained constant during healthy aging and in AD patients. Although only little is known about the function of activated macrophages and microglia in AD, one important mechanism involves the expression of quinolinic acid (QUIN), an endogenous N-methyl-D-aspartate glutamate receptor (NMDA-R) agonist which mediates excitotoxicity especially in the hippocampus. We used immunofluorescence stainings of PBMCs to determine the expression of quinolinic acid (QUIN) and the MHC class II molecule HLA-DR in peripheral monocytic cells in 51 healthy volunteers aged 22-87 years and 43 patients with AD at diagnosis (0 weeks) and during the course of rivastigmine treatment at 0.25 year (12 weeks), 0.5 year (30 weeks), 1 year, and 1.5 years. The number of QUIN+ HLA-DR+ cells rises in healthy persons aged 30-40 years compared to persons aged 60-70 years, indicating that this cell population increases with aging. AD patients at diagnosis had an increased frequency of QUIN+, QUIN+ HLA-DR+, and QUIN+ HLA-DR+/HLA-DR+ cells compared to aged-matched controls. These cell populations remained increased in AD for up to one year after initiation of treatment with rivastigmine; no alterations were detected in aged healthy persons. We conclude that the expression of the neurotoxic agent QUIN is increased in peripheral monocytes from AD patients. These cells could enter the brain and contribute to excitotoxicity.

  9. Oxidation of lactic acid by Vanadium(V) in sulphuric acid medium: a kinetic and mechanistic study

    OpenAIRE

    Clementin, Rosilene Maria; Takashima, Keiko

    1993-01-01

    The rate of lactic acid, HL, oxidation by vanadium(V), V(V), in sulphuric acid solution has been measured by monitoring, spectrophotometrically, the absorbance change of vanadium(IV), V(IV) in 760 nm at 30°C. This oxidation is a acid-catalysed, its dependence on acidity being complex. The rate constant or not the ionic strength. This reaction exhibited first order dependence on the V(V) and HL concentrations respectively and minimal dependence on sulphuric acid at lower concentrations (0.25 -...

  10. Ascorbic Acid may Exacerbate Aspirin-Induced Increase in Intestinal Permeability.

    Science.gov (United States)

    Sequeira, Ivana R; Kruger, Marlena C; Hurst, Roger D; Lentle, Roger G

    2015-09-01

    Ascorbic acid in combination with aspirin has been used to prevent aspirin-induced oxidative GI damage. We aimed to determine whether ascorbic acid reduces or prevents aspirin-induced changes in intestinal permeability over a 6-hr period using saccharidic probes mannitol and lactulose. The effects of administration of 600 mg aspirin alone, 500 mg ascorbic acid alone and simultaneous dosage of both agents were compared in a cross-over study in 28 healthy female volunteers. These effects were also compared with that of a placebo. The ability of ascorbic acid to mitigate the effects of aspirin when administered either half an hour before or after dosage with aspirin was also assessed in 19 healthy female volunteers. The excretion of lactulose over the 6-hr period was augmented after consumption of either aspirin or ascorbic acid compared with that after consumption of placebo. Dosage with ascorbic acid alone augmented the excretion of lactulose more than did aspirin alone. Simultaneous dosage with both agents augmented the excretion of lactulose in an additive manner. The timing of dosage with ascorbic acid in relation to that with aspirin had no significant effect on the excretion of the two sugars. These findings indicate that ascorbic acid does not prevent aspirin-induced increase in gut permeability rather that both agents augment it to a similar extent. The additive effect on simultaneous dosage with both agents in augmenting the absorption of lactulose suggests that each influences paracellular permeability by different pathways. © 2015 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

  11. Oleic acid-grafted chitosan/graphene oxide composite coating for corrosion protection of carbon steel.

    Science.gov (United States)

    Fayyad, Eman M; Sadasivuni, Kishor Kumar; Ponnamma, Deepalekshmi; Al-Maadeed, Mariam Al Ali

    2016-10-20

    An anticorrosion coating film based on the formation of nanocomposite coating is reported in this study. The composite consisted of chitosan (green matrix), oleic acid, and graphene oxide (nano filler). The nanocomposite coating was arranged on the surface of carbon steel, and the corrosion resistance was monitored using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PP). Compared to the pure chitosan (CS) coating, the corrosion resistance of oleic acid-modified chitosan/graphene oxide film (CS/GO-OA) is increased by 100 folds. Since the well-dispersed smart grafted nanolayers delayed the penetration rate of corrosive species and thus maintained long term anticorrosive stability which is correlated with hydrophobicity and permeability. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Ingestion of native and thermally oxidized polyunsaturated fats acutely increases circulating numbers of endothelial microparticles.

    Science.gov (United States)

    Sutherland, Wayne H F; de Jong, Sylvia A; Hessian, Paul A; Williams, Michael J A

    2010-03-01

    Circulating numbers of endothelial microparticles (EMP) are an index of endothelial injury and dysfunction; and microparticles positive to CD31 antibody increase acutely after cooked, fatty fast-food meals that are rich in saturated fatty acids (SAFA) and lipid oxidation products. The aim of this study was to determine the acute effect of meals rich in SAFA and native and thermally oxidized polyunsaturated vegetable oil on circulating numbers of EMP positive to CD144 antibody, a more specific marker of EMP. Twenty-two apparently healthy subjects received isocaloric meals rich in cream (CR), unheated sunflower oil, or heated sunflower oil in a randomized crossover study design. Circulating numbers of CD144-EMP and plasma lipids and Svedberg unit of flotation (S(f)) greater than 400 triglyceride content were measured before and 1 and 3 hours after the meals. Triglycerides in the plasma S(f) greater than 400 fraction increased significantly (P < .001) after the meals, with a significantly (P < .05) larger increase after the CR meal. Plasma CD144-EMP increased significantly (20%, P < .05) after the unheated sunflower oil and heated sunflower oil meals and did not increase significantly (P = .55) after the CR meal. This response was significantly different among the meals (P = .002) when first-visit fasting plasma glucose was a covariate. In conclusion, these data suggest that ingestion of meals rich in n-6 polyunsaturated vegetable oil irrespective of whether it has been mildly thermally oxidized may acutely alter the state of the vascular endothelium, resulting in increased shedding of CD144-EMP. The physiologic implications of these findings remain to be determined. (c) 2010 Elsevier Inc. All rights reserved.

  13. Constitutively elevated salicylic acid levels alter photosynthesis and oxidative state but not growth in transgenic populus.

    Science.gov (United States)

    Xue, Liang-Jiao; Guo, Wenbing; Yuan, Yinan; Anino, Edward O; Nyamdari, Batbayar; Wilson, Mark C; Frost, Christopher J; Chen, Han-Yi; Babst, Benjamin A; Harding, Scott A; Tsai, Chung-Jui

    2013-07-01

    Salicylic acid (SA) has long been implicated in plant responses to oxidative stress. SA overproduction in Arabidopsis thaliana leads to dwarfism, making in planta assessment of SA effects difficult in this model system. We report that transgenic Populus tremula × alba expressing a bacterial SA synthase hyperaccumulated SA and SA conjugates without negative growth consequences. In the absence of stress, endogenously elevated SA elicited widespread metabolic and transcriptional changes that resembled those of wild-type plants exposed to oxidative stress-promoting heat treatments. Potential signaling and oxidative stress markers azelaic and gluconic acids as well as antioxidant chlorogenic acids were strongly coregulated with SA, while soluble sugars and other phenylpropanoids were inversely correlated. Photosynthetic responses to heat were attenuated in SA-overproducing plants. Network analysis identified potential drivers of SA-mediated transcriptome rewiring, including receptor-like kinases and WRKY transcription factors. Orthologs of Arabidopsis SA signaling components NON-EXPRESSOR OF PATHOGENESIS-RELATED GENES1 and thioredoxins were not represented. However, all members of the expanded Populus nucleoredoxin-1 family exhibited increased expression and increased network connectivity in SA-overproducing Populus, suggesting a previously undescribed role in SA-mediated redox regulation. The SA response in Populus involved a reprogramming of carbon uptake and partitioning during stress that is compatible with constitutive chemical defense and sustained growth, contrasting with the SA response in Arabidopsis, which is transient and compromises growth if sustained.

  14. Niacin supplementation increases the number of oxidative type I fibers in skeletal muscle of growing pigs

    Science.gov (United States)

    2013-01-01

    Background A recent study showed that niacin supplementation counteracts the obesity-induced muscle fiber switching from oxidative type I to glycolytic type II and increases the number of type I fibers in skeletal muscle of obese Zucker rats. These effects were likely mediated by the induction of key regulators of fiber transition, PGC-1α and PGC-1β, leading to muscle fiber switching and up-regulation of genes involved in mitochondrial fatty acid import and oxidation, citrate cycle, oxidative phosphorylation, mitochondrial biogenesis. The aim of the present study was to investigate whether niacin supplementation causes type II to type I muscle and changes the metabolic phenotype of skeletal muscles in growing pigs. Results 25 male, 11 wk old crossbred pigs (Danzucht x Pietrain) with an average body weight of 32.8 ± 1.3 (mean ± SD) kg were randomly allocated to two groups of 12 (control group) and 13 pigs (niacin group) which were fed either a control diet or a diet supplemented with 750 mg niacin/kg diet. After 3 wk, the percentage number of type I fibers in three different muscles (M. longissismus dorsi, M. quadriceps femoris, M. gastrocnemius) was greater in the niacin group and the percentage number of type II fibers was lower in the niacin group than in the control group (P niacin group than in the control group (P niacin supplementation induces type II to type I muscle fiber switching, and thereby an oxidative metabolic phenotype of skeletal muscle in pigs. Given that oxidative muscle types tend to develop dark, firm and dry pork in response to intense physical activity and/or high psychological stress levels preslaughter, a niacin-induced change in the muscle´s fiber type distribution may influence meat quality of pigs. PMID:24010567

  15. Catalytic Effect of Cetyltrimethylammonium Bromide on the Oxidation of Triethylene glycol by Chloramine-T in Acidic Medium

    OpenAIRE

    Sharma, Vandana; Sharma, K. V.; Bhagwat, V. W.

    2008-01-01

    The kinetics and mechanism of cetyltrimethylammonium bromide catalyzed oxidation of triethylene glycol [2,2'-ethylene diqxybis(ethanol)] by chloramine-T in acidic acid medium have been investigated. The reaction is first order dependence on chloramine-T and fractional order for triethylene glycol with excess concentration of other reactants. The catalytic effect due to cetyletrimethylammonium bromide has been studied. The small salt effect and increase in the reaction rate with increasing die...

  16. Synthesis of Patchouli Biochar Cr2O3 Composite Using Double Acid Oxidators for Paracetamol Adsorption

    Directory of Open Access Journals (Sweden)

    Tutik Setianingsih

    2018-01-01

    Full Text Available Composite built by patchouli biochar and metal oxide, Cr2O3, is a potential material for remediation of contaminated wasterwater. Oxidation of biochar using acid or salt oxidators can improve its surface polar functional groups. This treatment may be able to increase impregnation of metal cation (as salt before calcination to form its oxide. In this research, 3 types of oxidators were used to oxidize the biochar before impregnation with purpose to study its influence toward physichochemistry and adsorption performance of the composite. Preparation of the composite included 3 steps, including preparation of biochar by pyrolisis of patchouli biomass using ZnCl2 activator at 450 oC, oxidation of the biochar using 3 different oxidators (H2SO4-HNO3, H3PO4-HNO3, H2O2–HNO3 at 60 oC, impregnation of the oxidized biochar using CrCl3 followed by calcination process to form biochar–Cr2O3 composite at 600 oC. Characterization using X-ray diffraction indicated that the composite containes the Cr2O3 structure. FTIR spectrophotometry characterization indicates the different content of C=O, C-O, and –OH on the composite surface. SEM images shows irregular micro ball shapes. EDX characterization indicates the different Cr content in the composite with same sequence with FTIR absorbances of both C-O and –OH. Adsorption of paracetamol indicates effect of Cr2O3 showing the same sequence of both.

  17. Leady oxide for lead/acid battery positive plates: scope for improvement?

    Science.gov (United States)

    Mayer, M. G.; Rand, D. A. J.

    Among the many factors that determine and influence the performance of lead/acid batteries, one of the most important, and as yet not fully developed, is how to make the positive active mass more electrochemically reactive. The inherent characteristics of this active mass are the cumulative result of the four precursor stages of its production, namely, the leady oxide, paste mixing, curing and formation procedures. There is evidence to suggest that the method of pasting itself is also influential. Many recent studies have reported progress on techniques to increase active-material utilization, to improve plate conditioning, and to solve the vexagious problem of premature capacity loss. The purpose of this discussion is to focus attention on the role and the importance of leady oxide on battery design and performance. At present, the battery industry makes leady oxide by either the ball-mill or the Barton-pot process. It is difficult to conclude which of the two methods gives the best leady oxide. Each type of leady oxide has its champions but, in general, ball-mill and Barton-pot product both make effective automotive batteries. For deep-cycle batteries, however, many battery companies (especially in Europe and Japan) prefer ball-mill oxide; in North America, the Barton-pot variety is favoured. This investigation examines the present procedures for making leady oxide, the desirable properties of leady oxide, and the influence of the oxide on battery performance. Analysis shows that there is scope for the production of improved leady oxide—by using existing production techniques and/or by the development of new processing technology.

  18. Circulating biologically active oxidized phospholipids show on-going and increased oxidative stress in older male mice

    Directory of Open Access Journals (Sweden)

    Jinbo Liu

    2013-01-01

    Significance: Oxidatively modified phospholipids are increased in the circulation during common, mild oxidant stresses of aging, or in male compared to female animals. Turnover of these biologically active phospholipids by rapid transport into liver and kidney is unchanged, so circulating levels reflect continuously increased production.

  19. Methanol oxidation at platinum electrodes in acid solution: comparison between model and real catalysts

    Directory of Open Access Journals (Sweden)

    A. V. TRIPKOVIC

    2006-12-01

    Full Text Available Methanol oxidation in acid solution was studied at platinum single crystals, Pt(hkl, as the model catalyst, and at nanostructural platinum supported on high surface area carbon, Pt/C, as the real catalyst. The linear extrapolation method was used to determine the beginning of hydroxyl anion adsorption. Structural sensitivity of the adsorption was proved and a correlation with the onset of the methanol oxidation current was established at all catalysts. Bisulfate and chloride anions were found to decrease the methanol oxidation rate, but probably did not influence the reaction parth. The specific activity for the reaction increased in the sequence Pt(110 < Pt/C < Pt(111, suggesting that the activity of the supported Pt catalyst can be correlated with the activities of the dominating crystal planes on its surface.

  20. Stabilization of hydrogen peroxide using tartaric acids in Fenton and fenton-like oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Hyung Suk; Kim, Jeong-Jin; Kim, Young-Hun [Andong National University, Andong (Korea, Republic of)

    2016-03-15

    The stabilization of hydrogen peroxide is a key factor in the efficiency of a Fenton reaction. The stability of hydrogen peroxide was evaluated in a Fenton reaction and Fenton-like reactions in the presence of tartaric acid as a stabilizer. The interactions between ferrous or ferric iron and tartaric acid were observed through spectroscopic monitoring at variable pH around pKa{sub 1} and pKa{sub 2} of the stabilizer. Ferric iron had a strong interaction with the stabilizer, and the strong interaction was dominant above pKa{sub 2}. At a low pH, below pKa{sub 1}, the stabilizing effect was at its maximum and the prolonged life-time of hydrogen peroxide gave a higher efficiency to the oxidative degradation of nitrobenzene. In Fenton-like reactions with hematite, the acidic conditions caused dissolution of iron from an iron oxide, and an increase in iron species was the result. Tartaric acid showed a stabilizing effect on hydrogen peroxide in the Fentonlike system. The stabilization by tartaric acid might be due to an inhibition of catalytic activity of dissolved iron, and the stabilization strongly depends on the ionization state of the stabilizer.

  1. Decreased arylesterase activity and increased total Decreased arylesterase activity and increased total oxidative status in rosacea

    Directory of Open Access Journals (Sweden)

    Sertac Sener

    2017-10-01

    Full Text Available Background: Rosacea is an inflammatory skin disease of face. In recent years, it is revealed that imbalance is significant in oxidant/antioxidant system in pathophysiology. Objective: In this study, the role of oxidative stress on rosacea was investigated. Methods: 34 rosacea patients and 33 healthy control cases between 18 and 70 years old are included in the study. In all the cases, serum lipids, Paraoxonase1(PON1, stimulated Paraoxonase1(stPON1, Arylesterase(ARES, Total Oxidant Status (TOS and Total Antioxidant Status (TAS levels are measured. Results: ARES levels were significantly lower and TOS levels were significantly higher in the patient group (p<0,001. Oxidative Stress Index(OSI was found to be shifted towards the oxidative side in the patient group (p<0,001. Conclusion: This situation shows that oxidative stress may have a role in the rosacea pathophysiology

  2. Biogeochemical processes governing natural pyrite oxidation and release of acid metalliferous drainage.

    Science.gov (United States)

    Chen, Ya-ting; Li, Jin-tian; Chen, Lin-xing; Hua, Zheng-shuang; Huang, Li-nan; Liu, Jun; Xu, Bi-bo; Liao, Bin; Shu, Wen-sheng

    2014-05-20

    The oxidative dissolution of sulfide minerals (principally pyrite) is responsible for the majority of acid metalliferous drainage from mine sites, which represents a significant environmental problem worldwide. Understanding the complex biogeochemical processes governing natural pyrite oxidation is critical not only for solving this problem but also for understanding the industrial bioleaching of sulfide minerals. To this end, we conducted a simulated experiment of natural pyrite oxidative dissolution. Pyrosequencing analysis of the microbial community revealed a distinct succession across three stages. At the early stage, a newly proposed genus, Tumebacillus (which can use sodium thiosulfate and sulfite as the sole electron donors), dominated the microbial community. At the midstage, Alicyclobacillus (the fifth most abundant genus at the early stage) became the most dominant genus, whereas Tumebacillus was still ranked as the second most abundant. At the final stage, the microbial community was dominated by Ferroplasma (the tenth most abundant genus at the early stage). Our geochemical and mineralogical analyses indicated that exchangeable heavy metals increased as the oxidation progressed and that some secondary sulfate minerals (including jarosite and magnesiocopiapite) were formed at the final stage of the oxidation sequence. Additionally, we propose a comprehensive model of biogeochemical processes governing the oxidation of sulfide minerals.

  3. Graphene Oxide-Gallic Acid Nanodelivery System for Cancer Therapy

    Science.gov (United States)

    Dorniani, Dena; Saifullah, Bullo; Barahuie, Farahnaz; Arulselvan, Palanisamy; Hussein, Mohd Zobir Bin; Fakurazi, Sharida; Twyman, Lance J.

    2016-11-01

    Despite the technological advancement in the biomedical science, cancer remains a life-threatening disease. In this study, we designed an anticancer nanodelivery system using graphene oxide (GO) as nanocarrier for an active anticancer agent gallic acid (GA). The successful formation nanocomposite (GOGA) was characterized using XRD, FTIR, HRTEM, Raman, and UV/Vis spectroscopy. The release study shows that the release of GA from the designed anticancer nanocomposite (GOGA) occurs in a sustained manner in phosphate-buffered saline (PBS) solution at pH 7.4. In in vitro biological studies, normal fibroblast (3T3) and liver cancer cells (HepG2) were treated with different concentrations of GO, GOGA, and GA for 72 h. The GOGA nanocomposite showed the inhibitory effect to cancer cell growth without affecting normal cell growth. The results of this research are highly encouraging to go further for in vivo studies.

  4. A chronic increase of corticosterone age-dependently reduces systemic DNA damage from oxidation in rats.

    Science.gov (United States)

    Jorgensen, Anders; Kalliokoski, Otto; Forsberg, Kristin; Breitenstein, Katrine; Weimann, Allan; Henriksen, Trine; Hau, Jann; Wörtwein, Gitta; Poulsen, Henrik Enghusen; Jorgensen, Martin Balslev

    2017-03-01

    Stress and depression are associated with an acceleration of brain and bodily aging; effects which have been attributed to chronic elevations of glucocorticoids. We tested the hypothesis that a three week administration of stress-associated levels of corticosterone (CORT, the principal rodent glucocorticoid) would increase systemic and CNS DNA and RNA damage from oxidation; a phenomenon known to be centrally involved in the aging process. We also hypothesized that older individuals would be more sensitive to this effect and that the chronic CORT administration would exacerbate age-related memory decline. Young and old male Sprague-Dawley rats were non-invasively administered CORT by voluntary ingestion of nut paste containing either CORT (25mg/kg) or vehicle for a total of 22 days. CORT increased the 24h urinary excretion of the hormone to the levels previously observed after experimental psychological stress and caused a downregulation of the glucocorticoid receptor in the CA1 area of the hippocampus. Contrary to our hypothesis, 24h excretion of 8-oxodG/8-oxoGuo (markers of DNA/RNA damage from oxidation) was reduced in CORT-treated young animals, whereas old animals showed no significant differences. In old animals, CORT caused a borderline significant reduction of RNA oxidation in CNS, which was paralleled by a normalization of performance in an object location memory test. To our knowledge, this is the first demonstration that chronic stress-associated levels of CORT can reduce nucleic acid damage from oxidation. These findings contradict the notion of elevated CORT as a mediator of the accelerated aging observed in stress and depression. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Decreased total antioxidant levels and increased oxidative stress in ...

    African Journals Online (AJOL)

    antioxidant-rich diet and lifestyle changes in T2DM patients would help to avert the debilitating complications of diabetes. Keywords: diabetes mellitus, oxidative stress, total antioxidant status. Introduction. Diabetes mellitus (DM) is a cluster of metabolic disorders characterised by abnormally elevated blood glucose levels.

  6. Mixed drink increased carbohydrate oxidation but not performance ...

    African Journals Online (AJOL)

    Kathryn van Boom

    It is well-established that consuming exogenous carbohydrate during prolonged physical activity improves performance.[1,2] The role of exogenous carbohydrate intake is hypothesised to provide additional substrate for oxidation[3] specifically influencing performance by decreasing endogenous liver glycogen utilisation ...

  7. Hyaluronic acid metabolism is increased in unstable plaques

    NARCIS (Netherlands)

    Bot, Pieter T.; Pasterkamp, Gerard; Goumans, Marie-José; Strijder, Chaylendra; Moll, Frans L.; de Vries, Jean-Paul; Pals, Steven T.; de Kleijn, Dominique P.; Piek, Jan J.; Hoefer, Imo E.

    2010-01-01

    P>Background Hyaluronic acid is expressed in atherosclerotic lesions, but its exact role in atherosclerotic disease remains unknown. As degradation of hyaluronic acid by hyaluronidase into low molecular weight hyaluronic acid (LMW-HA) is associated with inflammation and Matrix Metalloproteinase

  8. Fluorometric estimation of amino acids interaction with colloidal suspension of FITC functionalized graphene oxide nanoparticles

    Science.gov (United States)

    Dave, Kashyap; Dhayal, Marshal

    2017-02-01

    A hydrosol approach developed to synthesize fluorescence quenched fluorescein isothiocyanate (FITC) functionalized colloidal suspension of graphene oxide nanoparticles (GONP). UV-vis spectroscopic measurements showed characteristic peak at 236 nm and 300 nm due to pi-pi* interaction in Cdbnd C and n-pi* transition in Cdbnd O bond of GONP, respectively. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectra showed reduced intensity of 1429 cm-1 IR band of GONP due to the electrostatic and pi-pi interactions of FITC with GONP in FITC-GONP. ATR-FTIR spectra of different amino acid co-functionalised FITC-GONP showed an increase in the FTIR band intensity at 1429 cm-1 which was significantly reduced due to electrostatic/pi-pi interactions of FITC with GONP in the absence of the amino acids. A peak at 1084 cm-1 in ATR-FTIR spectra appears which confirms the interaction between amine group of amino acids and sbnd COO- groups at GONP surface. The FITC interaction with GONP lead to fluorescence resonance energy transfers (FRET) and resulted in a liner decrease in the FITC fluorescence with an increase of GONP concentration. An increase in the reappearance of FITC fluorescence observed while the amino acid concentration was increased in co-functionalised FITC-GONP. The quantified amount of reappeared fluorescence of FITC in amino acid co-functionalised FITC-GONP depends on the concentration, polar and non-polar nature of amino acids. The reappearance of FITC from the surface of FITC-GONP with the addition of amino acid was found to be consistent with the organic substitute, size of amino acids and their functionalities. Therefore, FRET based method using FITC-GONP colloidal suspension may have potential application in determining the binding nature of biomolecules with GONP for biomedical applications.

  9. Peroxynitrous acid: controversy and consensus surrounding an enigmatic oxidant.

    Science.gov (United States)

    Koppenol, Willem H; Bounds, Patricia L; Nauser, Thomas; Kissner, Reinhard; Rüegger, Heinz

    2012-12-07

    The isomerisation of ONOOH to NO(3)(-) and H(+), some oxidations and all hydroxylations and nitrations of aromatic compounds are first-order in ONOOH and zero-order in the compounds that are modified. These reactions are widely believed to proceed via homolysis of ONOOH into HO˙ and NO(2)˙ to an extent of ca. 30%. We review the evidence pro and contra homolysis in studies that involve (1) thermochemical considerations, (2) isomerisation to NO(3)(-) and H(+), (3) decomposition to NO(2)(-) and O(2), (4) HO˙ scavenger studies, (5) deuterium isotope effects, (6) (18)O-scrambling studies, (7) electrochemistry, (8) CIDNP NMR, and (9) photolysis. Our conclusion is that homolysis may be involved to a minor extent of ca. 5%. The initiation of ONOOH isomerisation may be visualised as an out-of-plane vibration of the terminal HO-group relative to the nitrogen. At ONOO(-) concentrations exceeding 0.1 mM and near neutral pH, disproportionation to NO(2)(-) and O(2) occurs; such disproportionations are typical for peroxy acids. For oxidation and nitration of organic substrates, we favour a mechanism involving initial formation of an adduct between the compound to be oxidised or nitrated and ONOOH.

  10. Sleep restriction increases free fatty acids in healthy men.

    Science.gov (United States)

    Broussard, Josiane L; Chapotot, Florian; Abraham, Varghese; Day, Andrew; Delebecque, Fanny; Whitmore, Harry R; Tasali, Esra

    2015-04-01

    Sleep loss is associated with insulin resistance and an increased risk for type 2 diabetes, yet underlying mechanisms are not understood. Elevation of circulating non-esterified (i.e. free) fatty acid (NEFA) concentrations can lead to insulin resistance and plays a central role in the development of metabolic diseases. Circulating NEFA in healthy individuals shows a marked diurnal variation with maximum levels occurring at night, yet the impact of sleep loss on NEFA levels across the 24 h cycle remains unknown. We hypothesised that sleep restriction would alter hormones that are known to stimulate lipolysis and lead to an increase in NEFA levels. We studied 19 healthy young men under controlled laboratory conditions with four consecutive nights of 8.5 h in bed (normal sleep) and 4.5 h in bed (sleep restriction) in randomised order. The 24 h blood profiles of NEFA, growth hormone (GH), noradrenaline (norepinephrine), cortisol, glucose and insulin were simultaneously assessed. Insulin sensitivity was estimated by a frequently sampled intravenous glucose tolerance test. Sleep restriction relative to normal sleep resulted in increased NEFA levels during the nocturnal and early-morning hours. The elevation in NEFA was related to prolonged nocturnal GH secretion and higher early-morning noradrenaline levels. Insulin sensitivity was decreased after sleep restriction and the reduction in insulin sensitivity was correlated with the increase in nocturnal NEFA levels. Sleep restriction in healthy men results in increased nocturnal and early-morning NEFA levels, which may partly contribute to insulin resistance and the elevated diabetes risk associated with sleep loss.

  11. Sleep restriction increases free fatty acids in healthy men

    Science.gov (United States)

    Broussard, Josiane L.; Chapotot, Florian; Abraham, Varghese; Day, Andrew; Delebecque, Fanny; Whitmore, Harry R.; Tasali, Esra

    2015-01-01

    Aims/hypothesis Sleep loss is associated with insulin resistance and an increased risk for type 2 diabetes, yet underlying mechanisms are not understood. Elevation of circulating non-esterified (i.e. free) fatty acid (NEFA) concentrations can lead to insulin resistance and plays a central role in the development of metabolic diseases. Circulating NEFA in healthy individuals shows a marked diurnal variation with maximum levels occurring at night, yet the impact of sleep loss on NEFA levels across the 24 h cycle remains unknown. We hypothesised that sleep restriction would alter hormones that are known to stimulate lipolysis and lead to an increase in NEFA levels. Methods We studied 19 healthy young men under controlled laboratory conditions with four consecutive nights of 8.5 h in bed (normal sleep) and 4.5 h in bed (sleep restriction) in randomised order. The 24 h blood profiles of NEFA, growth hormone (GH), noradrenaline (norepinephrine), cortisol, glucose and insulin were simultaneously assessed. Insulin sensitivity was estimated by a frequently sampled intravenous glucose tolerance test. Results Sleep restriction relative to normal sleep resulted in increased NEFA levels during the nocturnal and early-morning hours. The elevation in NEFA was related to prolonged nocturnal GH secretion and higher early-morning noradrenaline levels. Insulin sensitivity was decreased after sleep restriction and the reduction in insulin sensitivity was correlated with the increase in nocturnal NEFA levels. Conclusions/interpretation Sleep restriction in healthy men results in increased nocturnal and early-morning NEFA levels, which may partly contribute to insulin resistance and the elevated diabetes risk associated with sleep loss. PMID:25702040

  12. Melatonin protects against uric acid-induced mitochondrial dysfunction, oxidative stress, and triglyceride accumulation in C2C12myotubes.

    Science.gov (United States)

    Maarman, Gerald J; Andrew, Brittany M; Blackhurst, Dee M; Ojuka, Edward O

    2017-04-01

    Excess uric acid has been shown to induce oxidative stress, triglyceride accumulation, and mitochondrial dysfunction in the liver and is an independent predictor of type-2 diabetes. Skeletal muscle plays a dominant role in type 2 diabetes and presents a large surface area to plasma uric acid. However, the effects of uric acid on skeletal muscle are underinvestigated. Our aim was therefore to characterize the effects of excessive uric acid on oxidative stress, triglyceride content, and mitochondrial function in skeletal muscle C 2 C 12 myotubes and assess how these are modulated by the antioxidant molecule melatonin. Differentiated C 2 C 12 myotubes were exposed to 750 µM uric acid or uric acid + 10 nM melatonin for 72 h. Compared with control, uric acid increased triglyceride content by ~237%, oxidative stress by 32%, and antioxidant capacity by 135%. Uric acid also reduced endogenous ROUTINE respiration, complex II-linked oxidative phosphorylation, and electron transfer system capacities. Melatonin counteracted the effects of uric acid without further altering antioxidant capacity. Our data demonstrate that excess uric acid has adverse effects on skeletal muscle similar to those previously reported in hepatocytes and suggest that melatonin at a low physiological concentration of 10 nM may be a possible therapy against some adverse effects of excess uric acid. NEW & NOTEWORTHY Few studies have investigated the effects of uric acid on skeletal muscle. This study shows that hyperuricemia induces mitochondrial dysfunction and triglyceride accumulation in skeletal muscle. The findings may explain why hyperuricemia is an independent predictor of diabetes. Copyright © 2017 the American Physiological Society.

  13. C-Myc Induced Compensated Cardiac Hypertrophy Increases Free Fatty Acid Utilization for the Citric Acid Cycle

    Energy Technology Data Exchange (ETDEWEB)

    Olson, Aaron; Ledee, Dolena; Iwamoto, Kate; Kajimoto, Masaki; O' Kelly-Priddy, Colleen M.; Isern, Nancy G.; Portman, Michael A.

    2013-02-01

    The protooncogene C-Myc (Myc) regulates cardiac hypertrophy. Myc promotes compensated cardiac function, suggesting that the operative mechanisms differ from those leading to heart failure. Myc regulation of substrate metabolism is a reasonable target, as Myc alters metabolism in other tissues. We hypothesize that Myc-induced shifts in substrate utilization signal and promote compensated hypertrophy. We used cardiac specific Myc-inducible C57/BL6 male mice between 4-6 months old that develop hypertrophy with tamoxifen (tam). Isolated working hearts and 13Carbon (13C )-NMR were used to measure function and fractional contributions (Fc) to the citric acid cycle by using perfusate containing 13C-labeled free fatty acids, acetoacetate, lactate, unlabeled glucose and insulin. Studies were performed at pre-hypertrophy (3-days tam, 3dMyc), established hypertrophy (7-days tam, 7dMyc) or vehicle control (cont). Non-transgenic siblings (NTG) received 7-days tam or vehicle to assess drug effect. Hypertrophy was confirmed by echocardiograms and heart weights. Western blots were performed on key metabolic enzymes. Hypertrophy occurred in 7dMyc only. Cardiac function did not differ between groups. Tam alone did not affect substrate contribution in NTG. Substrate utilization was not significantly altered in 3dMyc versus cont. The free fatty acid FC was significantly greater in 7dMyc vs cont with decreased unlabeled Fc, which is predominately exogenous glucose. Free fatty acid flux to the citric acid cycle increased while lactate flux was diminished in 7dMyc compared to cont. Total protein levels of a panel of key metabolic enzymes were unchanged; however total protein O-GlcNAcylation was increased in 7dMyc. Substrate utilization changes did not precede hypertrophy; therefore they are not the primary signal for cardiac growth in this model. Free fatty acid utilization and oxidation increase at established hypertrophy. Understanding the mechanisms whereby this change maintained

  14. Manganese(II) catalyzes the bicarbonate-dependent oxidation of amino acids by hydrogen peroxide and the amino acid-facilitated dismutation of hydrogen peroxide.

    Science.gov (United States)

    Berlett, B S; Chock, P B; Yim, M B; Stadtman, E R

    1990-01-01

    In bicarbonate/CO2 buffer, Mn(II) and Fe(II) catalyze the oxidation of amino acids by H2O2 and the dismutation of H2O2. As the Mn(II)/Fe(II) ratio is increased, the yield of carbonyl compounds per mole of leucine oxidized is essentially constant, but the ratio of alpha-ketoisocaproate to isovaleraldehyde formed increases, and the fraction of H2O2 converted to O2 increases. In the absence of Fe(II), the rate of Mn(II)-catalyzed leucine oxidation is directly proportional to the H2O2, Mn(II), and amino acid concentrations and is proportional to the square of the HCO3- concentration. The rate of Mn(II)-catalyzed O2 production in the presence of 50 mM alanine or leucine is about 4-fold the rate observed in the absence of amino acids and accounts for about half of the H2O2 consumed; the other half of the H2O2 is consumed in the oxidation of the amino acids. In contrast, O2 production is increased nearly 18-fold by the presence of alpha-methylalanine and accounts for about 90% of the H2O2 consumed. The data are consistent with the view that H2O2 decomposition is an inner sphere (cage-like) process catalyzed by a Mn coordination complex of the composition Mn(II), amino acid, (HCO3-)2. Oxidation of the amino acid in this complex most likely proceeds by a free radical mechanism involving hydrogen abstraction from the alpha-carbon as a critical step. The results demonstrate that at physiological concentrations of HCO3- and CO2, Mn(II) is able to facilitate Fenton-type reactions.

  15. Palladium-catalyzed air-based oxidative coupling of arylboronic acids with H-phosphine oxides leading to aryl phosphine oxides.

    Science.gov (United States)

    Fu, Tingting; Qiao, Hongwei; Peng, Zhimin; Hu, Gaobo; Wu, Xueji; Gao, Yuxing; Zhao, Yufen

    2014-05-14

    We present a novel and highly efficient methodology that allows for the construction of C-P bonds via the palladium-catalyzed air-based oxidative coupling of various commercially available arylboronic acids with easily oxidized H-phosphine oxides leading to valuable aryl phosphine oxides, particularly triarylphosphine oxides, with the use of air as the green oxidant, broad substrate applicability and good to excellent yields. The described catalytic system should be an efficient complement to the Chan-Lam type reaction and be useful in synthetic programs.

  16. Dietary docosahexaenoic acid supplementation prevents the formation of cholesterol oxidation products in arteries from orchidectomized rats

    Science.gov (United States)

    Villalpando, Diva M.; Rojas, Mibsam M.; García, Hugo S.

    2017-01-01

    Testosterone deficiency has been correlated with increased cardiovascular diseases, which in turn has been associated with increased oxidative stress. Several studies have considered cholesterol oxidation products (COPs) as oxidative stress biomarkers, since some of them play pro-oxidant and pro-inflammatory roles. We have previously described the cardioprotective effects of a dosahexaenoic acid (DHA) supplemented diet on the aortic and mesenteric artery function of orchidectomized rats. The aim of this study was to investigate whether impaired gonadal function alters the formation of COPs, as well as the potential preventive role of a DHA-supplemented diet on that effect. For this purpose, aortic and mesenteric artery segments obtained from control and orchidectomized rats, fed with a standard or supplemented with DHA, were used. The content of the following COPs: 7α-hydroxycholesterol, 7β-hydroxycholesterol, 7-ketocholesterol, 5,6α-epoxycholesterol, 5,6β-epoxycholesterol, cholestanetriol and 25-hydroxycholesterol, were analyzed by gas chromatography. The results showed that orchidectomy increased the formation of COPs in arteries from orchidectomized rats, which may participate in the orchidectomy-induced structural and functional vascular alterations already reported. The fact that the DHA-supplemented diet prevented the orchidectomy-induced COPs increase confirms the cardiovascular protective actions of DHA, which could be of special relevance in mesenteric arterial bed, since it importantly controls the systemic vascular resistance. PMID:28968462

  17. Unexpected increase in the oxidation capacity of the urban atmosphere of Madrid, Spain

    Science.gov (United States)

    Saiz-Lopez, A.; Borge, R.; Notario, A.; Adame, J. A.; Paz, D. De La; Querol, X.; Artíñano, B.; Gómez-Moreno, F. J.; Cuevas, C. A.

    2017-04-01

    Atmospheric oxidants such as ozone (O3), hydroxyl and nitrate radicals (OH and NO3) determine the ability of the urban atmosphere to process organic and inorganic pollutants, which have an impact on air quality, environmental health and climate. Madrid city has experienced an increase of 30-40% in ambient air O3 levels, along with a decrease of 20-40% in NO2, from 2007 to 2014. Using air pollution observations and a high-resolution air quality model, we find a large concentration increase of up to 70% and 90% in OH and NO3, respectively, in downtown Madrid (domain-wide average increase of 10% and 32% for OH and NO3, respectively). The results also show an 11% reduction in the nitric acid concentrations, leading to a remarkable denoxification of this urban atmosphere with implications for lower PM2.5 levels and nitrogen input into ecosystems. This study suggests that projected worldwide NOx emission reductions, following air quality standards, will lead to important changes in the oxidizing capacity of the atmosphere in and around large cities.

  18. Biochemical competition makes fatty-acid β-oxidation vulnerable to substrate overload.

    Directory of Open Access Journals (Sweden)

    Karen van Eunen

    Full Text Available Fatty-acid metabolism plays a key role in acquired and inborn metabolic diseases. To obtain insight into the network dynamics of fatty-acid β-oxidation, we constructed a detailed computational model of the pathway and subjected it to a fat overload condition. The model contains reversible and saturable enzyme-kinetic equations and experimentally determined parameters for rat-liver enzymes. It was validated by adding palmitoyl CoA or palmitoyl carnitine to isolated rat-liver mitochondria: without refitting of measured parameters, the model correctly predicted the β-oxidation flux as well as the time profiles of most acyl-carnitine concentrations. Subsequently, we simulated the condition of obesity by increasing the palmitoyl-CoA concentration. At a high concentration of palmitoyl CoA the β-oxidation became overloaded: the flux dropped and metabolites accumulated. This behavior originated from the competition between acyl CoAs of different chain lengths for a set of acyl-CoA dehydrogenases with overlapping substrate specificity. This effectively induced competitive feedforward inhibition and thereby led to accumulation of CoA-ester intermediates and depletion of free CoA (CoASH. The mitochondrial [NAD⁺]/[NADH] ratio modulated the sensitivity to substrate overload, revealing a tight interplay between regulation of β-oxidation and mitochondrial respiration.

  19. Synthesis and characterization of hybrid composite aerogels from alginic acid and graphene oxide

    Science.gov (United States)

    Co, C. J. U.; Quitain, A. T.; Borja, J. Q.; Dugos, N. P.; Takafuji, M.; Kida, T.

    2017-06-01

    Aerogels are one class of solid adsorbents that are gaining considerable attention because of their very high porosity, high specific surface area, and extremely low density. However, most aerogels being studied and used recently are synthetic in nature, which are usually mesoporous silica and metal-organic frameworks (MOFs). As research focus is geared towards sustainable engineering, it is desired to utilize biomass to synthesize aerogels. This study thus aims to produce alginic acid-graphene oxide hybrid composite aerogels and compare them with its existing synthetic counterparts. Alginic acid (AA) is an abundant marine biopolymer that easily forms gels, while graphene oxide (GO) is a nanomaterial consisting of many functional groups. Aerogels made up of AA and GO were successfully synthesized using a sol-gel method. The hydrogel was converted into an aerogel by drying with supercritical carbon dioxide. The percentage of graphene oxide was varied from 0 to 20%. The aerogels were characterized by scanning electron microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and nitrogen adsorption-desorption measurements. The addition of GO increased the specific surface area of the aerogel up to a certain point, after which it decreased. The 10% GO-AA aerogel showed the most favourable porosity characteristics with a specific surface area of 177.26 m2/g and average pore diameter of 53.2 nm. There had been no observable difference in the thermal behaviour of the aerogels with a change in the concentration of graphene oxide.

  20. Antioxidant evaluation and oxidative stability of structured lipids from extravirgin olive oil and conjugated linoleic acid.

    Science.gov (United States)

    Lee, Jeung Hee; Lee, Ki-teak; Akoh, Casimir C; Chung, Shin Kyo; Kim, Mee Ree

    2006-07-26

    Structured lipid (SL) was synthesized from extravirgin olive oil (EVOO) and conjugated linoleic acid (CLA) via a lipase-catalyzed reaction. CLA provides a variety of health benefits, but it is not consumed in free fatty acid form. The synthesized SL olive oil contained 42.5 mol % CLA isomers, and the major isomers were cis-9,trans-11-CLA (16.9 mol %) and trans-10,cis-12-CLA (24.2 mol %). The antioxidant activity determined by the radical scavenging capacity with the 2,2-diphenyl-1-picrylhydrazyl radical was lower in SL olive oil than in EVOO. The oxidative stability was also lower in SL olive oil since it had a higher peroxide value, rho-anisidine value, and 2-thiobarbituric acid reactive substances values during 20 days of storage at 60 degrees C. This observation could be due to the reduction in the natural phenolic compounds (97%) and tocopherols (56%), and the incorporated CLA with two conjugated double bonds in the SL olive oil. The oxidative stability of SL olive oil was increased by added rosemary extracts at concentrations of 100, 200, and 300 ppm. The present study suggests that the SL olive oil may be a suitable way to incorporate or deliver CLA into human diets. However, the addition of a proper antioxidant would be required for improving its oxidative stability.

  1. Dietary guanidinoacetic acid increases brain creatine levels in healthy men.

    Science.gov (United States)

    Ostojic, Sergej M; Ostojic, Jelena; Drid, Patrik; Vranes, Milan; Jovanov, Pavle

    2017-01-01

    Guanidinoacetic acid (GAA) is an experimental dietary additive that might act as a creatine source in tissues with high-energy requirements. In this case study, we evaluated brain levels of creatine in white matter, gray matter, cerebellum, and thalamus during 8 wk oral GAA administration in five healthy men and monitored the prevalence and severity of side effects of the intervention. Volunteers were supplemented daily with 36 mg/kg body weight (BW) of GAA for the first 4 wk of the intervention; afterward GAA dosage was titrated ≤60 mg/kg BW of GAA daily. At baseline, 4, and 8 wk, the participants underwent brain magnetic resonance spectroscopy, clinical chemistry studies, and open-ended questionnaire for side-effect prevalence and severity. Brain creatine levels increased in similar fashion in cerebellum, and white and gray matter after GAA supplementation, with an initial increase of 10.7% reported after 4 wk, and additional upsurge (7.7%) from the weeks 4 to 8 follow-up (P creatine levels decreased after 4 wk for 6.5% (P = 0.02), and increased nonsignificantly after 8 wk for 8% (P = 0.09). GAA induced an increase in N-acetylaspartate levels at 8-wk follow-up in all brain areas evaluated (P creatine pool in the human brain. This might be relevant for restoring cellular bioenergetics in disorders characterized by low brain creatine and functional enzymatic machinery for creatine synthesis, including neurodegenerative diseases, brain tumors, or cerebrovascular disease. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Oxidation of phenyl alanine by pyridinium chlorochromate in acidic DMF–water medium: A kinetic study

    Directory of Open Access Journals (Sweden)

    B.L. Hiran

    2016-11-01

    Full Text Available The kinetics of oxidation of phenyl alanine by pyridinium chlorochromate in DMF–water (70:30% mixture in presence of perchloric acid leads to the formation of corresponding aldehyde. The reaction is of first order each in [PCC], [HClO4] and [AA]. Michaelis–Menten type kinetics was observed with phenyl alanine. The reaction rates were determined at different temperatures [25, 30, 35, 40, 45, 50 °C] and the activation parameters were calculated. The reaction does not induce polymerization of acrylonitrile. With an increase in the amount of DMF in its aqueous mixture, the rate increases. A suitable mechanism for the reaction was postulated.

  3. Acid-activated biochar increased sulfamethazine retention in soils.

    Science.gov (United States)

    Vithanage, Meththika; Rajapaksha, Anushka Upamali; Zhang, Ming; Thiele-Bruhn, Sören; Lee, Sang Soo; Ok, Yong Sik

    2015-02-01

    Sulfamethazine (SMZ) is an ionizable and highly mobile antibiotic which is frequently found in soil and water environments. We investigated the sorption of SMZ onto soils amended with biochars (BCs) at varying pH and contact time. Invasive plants were pyrolyzed at 700 °C and were further activated with 30 % sulfuric (SBBC) and oxalic (OBBC) acids. The sorption rate of SMZ onto SBBC and OBBC was pronouncedly pH dependent and was decreased significantly when the values of soil pH increased from 3 to 5. Modeled effective sorption coefficients (K D,eff) values indicated excellent sorption on SBBC-treated loamy sand and sandy loam soils for 229 and 183 L/kg, respectively. On the other hand, the low sorption values were determined for OBBC- and BBC700-treated loamy sand and sandy loam soils. Kinetic modeling demonstrated that the pseudo second order model was the best followed by intra-particle diffusion and the Elovich model, indicating that multiple processes govern SMZ sorption. These findings were also supported by sorption edge experiments based on BC characteristics. Chemisorption onto protonated and ligand containing functional groups of the BC surface, and diffusion in macro-, meso-, and micro-pores of the acid-activated BCs are the proposed mechanisms of SMZ retention in soils. Calculated and experimental q e (amount adsorbed per kg of the adsorbent at equilibrium) values were well fitted to the pseudo second order model, and the predicted maximum equilibrium concentration of SBBC for loamy sand soils was 182 mg/kg. Overall, SBBC represents a suitable soil amendment because of its high sorption rate of SMZ in soils.

  4. Synergistic Effects of Zinc Oxide Nanoparticles and Fatty Acids on Toxicity to Caco-2 Cells

    DEFF Research Database (Denmark)

    Cao, Yi; Roursgaard, Martin; Kermanizadeh, Ali

    2015-01-01

    Fatty acids exposure may increase sensitivity of intestinal epithelial cells to cytotoxic effects of zinc oxide (ZnO) nanoparticles (NPs). This study evaluated the synergistic effects of ZnO NPs and palmitic acid (PA) or free fatty acids (FFAs) mixture (oleic/PA 2:1) on toxicity to human colon...... epithelial (Caco-2) cells. The ZnO NPs exposure concentration dependently induced cytotoxicity to Caco-2 cells showing as reduced proliferation and activity measured by 3 different assays. PA exposure induced cytotoxicity, and coexposure to ZnO NPs and PA showed the largest cytotoxic effects. The presence...... of FFAs mixture did not affect the ZnO NPs-induced cytotoxicity. Filtration of freshly prepared suspension of NPs through a 0.45-µm pore size membrane significantly reduced the cytotoxicity, indicating a role of concentration or size of particles in cytotoxic effects. The ZnO NPs and PA coexposure induced...

  5. Oxidation of indole-3-acetic acid to oxindole-3-acetic acid by an enzyme preparation from Zea mays

    Science.gov (United States)

    Reinecke, D. M.; Bandurski, R. S.

    1988-01-01

    Indole-3-acetic acid is oxidized to oxindole-3-acetic acid by Zea mays tissue extracts. Shoot, root, and endosperm tissues have enzyme activities of 1 to 10 picomoles per hour per milligram protein. The enzyme is heat labile, is soluble, and requires oxygen for activity. Cofactors of mixed function oxygenase, peroxidase, and intermolecular dioxygenase are not stimulatory to enzymic activity. A heat-stable, detergent-extractable component from corn enhances enzyme activity 6- to 10-fold. This is the first demonstration of the in vitro enzymic oxidation of indole-3-acetic acid to oxindole-3-acetic acid in higher plants.

  6. Chronic infusion of taurolithocholate into the brain increases fat oxidation in mice.

    Science.gov (United States)

    Eggink, Hannah M; Tambyrajah, Lauren L; van den Berg, Rosa; Mol, Isabel M; van den Heuvel, Jose K; Koehorst, Martijn; Groen, Albert K; Boelen, Anita; Kalsbeek, Andries; Romijn, Johannes A; Rensen, Patrick C N; Kooijman, Sander; Soeters, Maarten R

    2018-02-01

    Bile acids can function in the postprandial state as circulating signaling molecules in the regulation of glucose and lipid metabolism via the transmembrane receptor TGR5 and nuclear receptor FXR. Both receptors are present in the central nervous system, but their function in the brain is unclear. Therefore, we investigated the effects of intracerebroventricular (i.c.v.) administration of taurolithocholate (tLCA), a strong TGR5 agonist, and GW4064, a synthetic FXR agonist, on energy metabolism. We determined the effects of chronic i.c.v. infusion of tLCA, GW4064, or vehicle on energy expenditure, body weight and composition as well as tissue specific fatty acid uptake in mice equipped with osmotic minipumps. We found that i.c.v. administration of tLCA (final concentration in cerebrospinal fluid: 1 μM) increased fat oxidation (tLCA group: 0.083 ± 0.006 vs control group: 0.036 ± 0.023 kcal/h, F = 5.46, P = 0.04) and decreased fat mass (after 9 days of tLCA infusion: 1.35 ± 0.13 vs controls: 1.96 ± 0.23 g, P = 0.03). These changes were associated with enhanced uptake of triglyceride-derived fatty acids by brown adipose tissue and with browning of subcutaneous white adipose tissue. I.c.v. administration of GW4064 (final concentration in cerebrospinal fluid: 10 μM) did not affect energy metabolism, body composition nor bile acid levels, negating a role of FXR in the central nervous system in metabolic control. In conclusion, bile acids such as tLCA may exert metabolic effects on fat metabolism via the brain. © 2018 Society for Endocrinology.

  7. Exercise increases mitochondrial glutamate oxidation in the mouse cerebral cortex.

    Science.gov (United States)

    Herbst, Eric A F; Holloway, Graham P

    2016-07-01

    The present study investigated the impact of acute exercise on stimulating mitochondrial respiratory function in mouse cerebral cortex. Where pyruvate-stimulated respiration was not affected by acute exercise, glutamate respiration was enhanced following the exercise bout. Additional assessment revealed that this affect was dependent on the presence of malate and did not occur when substituting glutamine for glutamate. As such, our results suggest that glutamate oxidation is enhanced with acute exercise through activation of the malate-aspartate shuttle.

  8. Increased LDL susceptibility to oxidation accelerates future carotid artery atherosclerosis

    Directory of Open Access Journals (Sweden)

    Aoki Toshinari

    2012-01-01

    Full Text Available Abstract Background We analyzed the causal relationship between LDL susceptibility to oxidation and the development of new carotid artery atherosclerosis over a period of 5 years. We previously described the determinants related to a risk of cardiovascular changes determined in a Japanese population participating in the Niigata Study, which is an ongoing epidemiological investigation of the prevention of cardiovascular diseases. Methods We selected 394 individuals (169 males and 225 females who underwent a second carotid artery ultrasonographic examination in 2001 - 2002 for the present study. The susceptibility of LDL to oxidation was determined as the photometric absorbance and electrophoretic mobility of samples that had been collected in 1996 - 1997. The measurements were compared with ultrasonographic findings obtained in 2001 - 2002. Results The multivariate-adjusted model showed that age (odds ratio (OR, 1.034; 95% confidence interval (95%CI, 1.010 - 1.059, HbA1c (OR, 1.477; 95%CI, 0.980 - 2.225, and photometric O/N (OR, 2.012; 95%CI, 1.000 - 4.051 were significant variables that could independently predict the risk of new carotid artery atherosclerosis. Conclusion The susceptibility of LDL to oxidation was a significant parameter that could predict new carotid artery atherosclerosis over a 5-year period, and higher susceptibility was associated with a higher incidence of new carotid artery atherosclerosis.

  9. Histidine Regulates Seed Oil Deposition through Abscisic Acid Biosynthesis and β-Oxidation1

    Science.gov (United States)

    2016-01-01

    The storage compounds are deposited into plant seeds during maturation. As the model oilseed species, Arabidopsis (Arabidopsis thaliana) has long been studied for seed oil deposition. However, the regulation of this process remains unclear. Through genetic screen with a seed oil body-specific reporter, we isolated low oil1 (loo1) mutant. LOO1 was mapped to HISTIDINE BIOSYNTHESIS NUMBER 1A (HISN1A). HISN1A catalyzes the first step of His biosynthesis. Oil significantly decreased, and conversely proteins markedly increased in hisn1a mutants, indicating that HISN1A regulates both oil accumulation and the oil-protein balance. HISN1A was predominantly expressed in embryos and root tips. Accordingly, the hisn1a mutants exhibited developmental phenotype especially of seeds and roots. Transcriptional profiling displayed that β-oxidation was the major metabolic pathway downstream of HISN1A. β-Oxidation was induced in hisn1a mutants, whereas it was reduced in 35S:HISN1A-transgenic plants. In plants, seed storage oil is broken-down by β-oxidation, which is controlled by abscisic acid (ABA). We found that His activated genes of ABA biosynthesis and correspondingly advanced ABA accumulation. Exogenous ABA rescued the defects of hisn1a mutants, whereas mutation of ABA DEFICIENT2, a key enzyme in ABA biosynthesis, blocked the effect of His on β-oxidation, indicating that ABA mediates His regulation in β-oxidation. Intriguingly, structural analysis showed that a potential His-binding domain was present in the general amino acid sensors GENERAL CONTROL NON-DEREPRESSIBLE2 and PII, suggesting that His may serve as a signal molecule. Taken together, our study reveals that His promotes plant seed oil deposition through ABA biosynthesis and β-oxidation. PMID:27493214

  10. Histidine Regulates Seed Oil Deposition through Abscisic Acid Biosynthesis and β-Oxidation.

    Science.gov (United States)

    Ma, Huimin; Wang, Shui

    2016-10-01

    The storage compounds are deposited into plant seeds during maturation. As the model oilseed species, Arabidopsis (Arabidopsis thaliana) has long been studied for seed oil deposition. However, the regulation of this process remains unclear. Through genetic screen with a seed oil body-specific reporter, we isolated low oil1 (loo1) mutant. LOO1 was mapped to HISTIDINE BIOSYNTHESIS NUMBER 1A (HISN1A). HISN1A catalyzes the first step of His biosynthesis. Oil significantly decreased, and conversely proteins markedly increased in hisn1a mutants, indicating that HISN1A regulates both oil accumulation and the oil-protein balance. HISN1A was predominantly expressed in embryos and root tips. Accordingly, the hisn1a mutants exhibited developmental phenotype especially of seeds and roots. Transcriptional profiling displayed that β-oxidation was the major metabolic pathway downstream of HISN1A β-Oxidation was induced in hisn1a mutants, whereas it was reduced in 35S:HISN1A-transgenic plants. In plants, seed storage oil is broken-down by β-oxidation, which is controlled by abscisic acid (ABA). We found that His activated genes of ABA biosynthesis and correspondingly advanced ABA accumulation. Exogenous ABA rescued the defects of hisn1a mutants, whereas mutation of ABA DEFICIENT2, a key enzyme in ABA biosynthesis, blocked the effect of His on β-oxidation, indicating that ABA mediates His regulation in β-oxidation. Intriguingly, structural analysis showed that a potential His-binding domain was present in the general amino acid sensors GENERAL CONTROL NON-DEREPRESSIBLE2 and PII, suggesting that His may serve as a signal molecule. Taken together, our study reveals that His promotes plant seed oil deposition through ABA biosynthesis and β-oxidation. © 2016 American Society of Plant Biologists. All Rights Reserved.

  11. Manganese (Mn oxidation increases intracellular Mn in Pseudomonas putida GB-1.

    Directory of Open Access Journals (Sweden)

    Andy Banh

    Full Text Available Bacterial manganese (Mn oxidation plays an important role in the global biogeochemical cycling of Mn and other compounds, and the diversity and prevalence of Mn oxidizers have been well established. Despite many hypotheses of why these bacteria may oxidize Mn, the physiological reasons remain elusive. Intracellular Mn levels were determined for Pseudomonas putida GB-1 grown in the presence or absence of Mn by inductively coupled plasma mass spectrometry (ICP-MS. Mn oxidizing wild type P. putida GB-1 had higher intracellular Mn than non Mn oxidizing mutants grown under the same conditions. P. putida GB-1 had a 5 fold increase in intracellular Mn compared to the non Mn oxidizing mutant P. putida GB-1-007 and a 59 fold increase in intracellular Mn compared to P. putida GB-1 ∆2665 ∆2447. The intracellular Mn is primarily associated with the less than 3 kDa fraction, suggesting it is not bound to protein. Protein oxidation levels in Mn oxidizing and non oxidizing cultures were relatively similar, yet Mn oxidation did increase survival of P. putida GB-1 when oxidatively stressed. This study is the first to link Mn oxidation to Mn homeostasis and oxidative stress protection.

  12. Amino Acid Medical Foods Provide a High Dietary Acid Load and Increase Urinary Excretion of Renal Net Acid, Calcium, and Magnesium Compared with Glycomacropeptide Medical Foods in Phenylketonuria

    National Research Council Canada - National Science Library

    Bridget M. Stroup; Emily A. Sawin; Sangita G. Murali; Neil Binkley; Karen E. Hansen; Denise M. Ney

    2017-01-01

    .... We tested the hypothesis that amino acid medical foods (AA-MF) provide a high dietary acid load, subsequently increasing urinary excretion of renal net acid, calcium, and magnesium, compared to glycomacropeptide medical foods (GMP-MF). Design...

  13. Ameliorative Effects of Caffeic Acid on Lead Accumulation and Oxidative Stress in Lead-Exposed Mice

    Directory of Open Access Journals (Sweden)

    Maryam Lotfi-Ghahramanloo

    2016-05-01

    Full Text Available Background The currently approved treatment for lead toxicity is chelation therapy to reduce the burden of the toxic effects of lead, but the safety and efficacy of the various chelating agents may be questioned. Objectives This study was aimed to evaluate the effects of caffeic acid, a dietary non-flavonoid phenolic acid, on lead accumulation and lead-induced oxidative stress in mice. Materials and Methods In this experimental study, 24 mice were divided into four groups. Group 1 served as control. Mice in group 2 received water containing 1000 ppm lead acetate. Group 3 animals received caffeic acid (60 mg/kg body weight i.p. during lead treatment. Mice in group 4 only received caffeic acid. At the end of the experiment (18 days, blood samples were drawn and the levels of lead and some oxidative-stress related parameters were measured. Results Blood Pb concentration increased significantly in group 2 as compared to control group. Lead exposure caused significant increase of malondialdehyde and decrease of glutathione concentrations in erythrocyte haemolysate as compared to control group. Although caffeic acid was effective in normalization of the attenuated levels of erythrocytic glutathione, its administration had no significant effect in decreasing the augmented levels of erythrocytic malondialdehyde in group 3. Values of other measured parameters including erythrocytic activities of glutathione peroxidase and superoxide dismutase did not change significantly among experimental groups. Conclusions Present results show some beneficial effects of caffeic acid against lead poisoning and it can be thus proposed as a potential prophylactic treatment for amelioration of lead toxicity.

  14. Uric acid excretion predicts increased aggression in urban adolescents.

    Science.gov (United States)

    Mrug, Sylvie; Mrug, Michal

    2016-09-01

    Elevated levels of uric acid have been linked with impulsive and disinhibited behavior in clinical and community populations of adults, but no studies have examined uric acid in relation to adolescent aggression. This study examined the prospective role of uric acid in aggressive behavior among urban, low income adolescents, and whether this relationship varies by gender. A total of 84 adolescents (M age 13.36years; 50% male; 95% African American) self-reported on their physical aggression at baseline and 1.5years later. At baseline, the youth also completed a 12-h (overnight) urine collection at home which was used to measure uric acid excretion. After adjusting for baseline aggression and age, greater uric acid excretion predicted more frequent aggressive behavior at follow up, with no significant gender differences. The results suggest that lowering uric acid levels may help reduce youth aggression. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Evidence for two enzymatic pathways for omega-oxidation of docosanoic acid in rat liver microsomes

    NARCIS (Netherlands)

    Sanders, Robert-Jan; Ofman, Rob; Valianpour, Fredoen; Kemp, Stephan; Wanders, Ronald J. A.

    2005-01-01

    We studied the omega-oxidation of docosanoic acid (C22:0) in rat liver microsomes. C22:0 and 22-hydroxy-docosanoic acid (omega-hydroxy-C22:0) were used as substrates, and the reaction products were analyzed by electrospray ionization mass spectrometry. In the presence of NADPH, omega-oxidation of

  16. Hepatic fatty acid oxidation : activity, localization and function of some enzymes involved

    NARCIS (Netherlands)

    A. van Tol (Arie)

    1971-01-01

    textabstractFatty acid oxidation is an important pathway for energy production in mammals and birds. In animal tissues the enzymes of fatty acid oxidation are located in the mitochondrion. Recent reports suggest that this is not the case in Castor bean endosperm. In this tissue the enzymes of

  17. Neuropsychological Outcomes in Fatty Acid Oxidation Disorders: 85 Cases Detected by Newborn Screening

    Science.gov (United States)

    Waisbren, Susan E.; Landau, Yuval; Wilson, Jenna; Vockley, Jerry

    2013-01-01

    Mitochondrial fatty acid oxidation disorders include conditions in which the transport of activated acyl-Coenzyme A (CoA) into the mitochondria or utilization of these substrates is disrupted or blocked. This results in a deficit in the conversion of fat into energy. Most patients with fatty acid oxidation defects are now identified through…

  18. Recombinant microorganisms for increased production of organic acids

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Jian; Kleff, Susanne; Guettler, Michael V

    2013-04-30

    Disclosed are recombinant microorganisms for producing organic acids. The recombinant microorganisms express a polypeptide that has the enzymatic activity of an enzyme that is utilized in the pentose phosphate cycle. The recombinant microorganism may include recombinant Actinobacillus succinogenes that has been transformed to express a Zwischenferment (Zwf) gene. The recombinant microorganisms may be useful in fermentation processes for producing organic acids such as succinic acid and lactic acid. Also disclosed are novel plasmids that are useful for transforming microorganisms to produce recombinant microorganisms that express enzymes such as Zwf.

  19. Recombinant microorganisms for increased production of organic acids

    Science.gov (United States)

    Yi, Jian [East Lansing, MI; Kleff, Susanne [East Lansing, MI; Guettler, Michael V [Holt, MI

    2012-02-21

    Disclosed are recombinant microorganisms for producing organic acids. The recombinant microorganisms express a polypeptide that has the enzymatic activity of an enzyme that is utilized in the pentose phosphate cycle. The recombinant microorganism may include recombinant Actinobacillus succinogenes that has been transformed to express a Zwischenferment (Zwf) gene. The recombinant microorganisms may be useful in fermentation processes for producing organic acids such as succinic acid and lactic acid. Also disclosed are novel plasmids that are useful for transforming microorganisms to produce recombinant microorganisms that express enzymes such as Zwf.

  20. Urinary markers of nucleic acid oxidation and cancer in type 2 diabetes

    DEFF Research Database (Denmark)

    Broedbaek, Kasper; Siersma, Volkert; Henriksen, Trine Foged

    2015-01-01

    with breast cancer in the crude analyses (unadjusted hazard ratio for breast cancer per natural log increase in 8-oxodG was 2.37 [95% CI, 1.07-5.26]), although the association was attenuated in the adjusted analyses (sex- and age-adjusted hazard ratio 2.15 [95% CI, 0.92-5.02] and multivariate adjusted hazard......AIMS/HYPOTHESIS: We investigated whether urinary markers of nucleic acid oxidation are associated with an increased risk of cancer in type 2 diabetes patients. METHODS: Urine samples from 1381 newly diagnosed diabetes patients were assayed for the oxidatively modified guanine nucleosides 8-oxo-7......,8-dihydro-2'-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydroguanosine (8-oxoGuo). Cox proportional hazards regression was used to examine the relationship between the urinary markers and cancer incidence. RESULTS: The crude analyses showed an association between overall cancer and urinary excretion...

  1. Adenosine deaminase, xanthine oxidase, uric acid, and nitric oxide metabolism in the pathogenesis of disease in patients with colon polyps

    Directory of Open Access Journals (Sweden)

    Rafet Mete

    2014-03-01

    Full Text Available Objective: Protrusion of colonic mucosa to the lumen is called polyp. Since adenomatous polyps are neoplastic polyps, determining the factors contributing to the pathogenesis of the disease would be helpful in terms of reducing mortality and morbidity. Variety studies have showed that increased oxidative stress might play an important role in carcinogenesis. The aim of this study was to investigate the relationship between adenosine deaminase, xanthine oxidase nitric oxide, uric acid levels and oxidative stress in patients with colonic polyps to help the elucidation of pathophysiology of the disease. Methods: The study was conducted at Gastroenterology Clinics of Namik Kemal University Training and Research Hospital. Thirty-five subjects who underwent colonoscopy because of any gastrointestinal symptom and whose pathologic evaluation of colonoscopic biopsy revealed adenomatous polyps were enrolled as patient group. Control group was consisted of 36 healthy subjects. Uric acid was measured by an autoanalyzer using photometric method. Adenosine deaminase, xanthine oxidase, and nitric oxide were measured manually using a spectrophotometric method. Results: Xanthine oxidase, uric acid, and nitric oxide levels were found to be significantly higher in patients with colonic polyp compared that of the healthy controls. (p = 0.007; p = 0.02; p<0.001, respectively.Although adenosine deaminase levels were significantly higher in patient group, the difference was not statistically significant (p = 0.07 Conclusion: Increased serum levels of adenosine deaminase, xanthine oxidase, nitric oxide, and uric acid levels in patients with colonic adenomatous polyp may indicate the increased oxidative stress and the oxidative impairment of the colonic mucosa which may play an important role in the pathophysiology of the disease. Further studies would be useful to assess antioxidant treatment options in these patients.

  2. Effect of ascorbic acid supplementation on nitric oxide metabolites and systolic blood pressure in rats exposed to lead.

    Science.gov (United States)

    Mohammad, Amani; Ali, Noroozzadeh; Reza, Badalzadeh; Ali, Khoshbaten

    2010-04-01

    Extended exposure to low levels of lead causes high blood pressure in human and laboratory animals. The mechanism is not completely recognized, but it is relatively implicated with generation of free radicals, oxidant agents such as ROS, and decrease of available nitric oxide (NO). In this study, we have demonstrated the effect of ascorbic acid as an antioxidant on nitric oxide metabolites and systolic blood pressure in rats exposed to low levels of lead. The adult male Wistar rats weighing 200-250 g were divided into four groups: control, lead acetate (receiving 100 ppm lead acetate in drinking water), lead acetate plus ascorbic acid (receiving 100 ppm lead acetate and 1 g/l ascorbic acid in drinking water), and ascorbic acid (receiving 1 g/l ascorbic acid in drinking water) groups. The animals were anesthetized with ketamin/xylazine (50 and 7 mg/kg, respectively, ip) and systolic blood pressure was then measured from the tail of the animals by a sphygmomanometer. Nitric oxide levels in serum were measured indirectly by evaluation of its stable metabolites (total nitrite and nitrate (NOchi)). After 8 and 12 weeks, systolic blood pressure in the lead acetate group was significantly elevated compared to the control group. Ascorbic acid supplementation could prevent the systolic blood pressure rise in the lead acetate plus ascorbic acid group and there was no significant difference relative to the control group. The serum NOchi levels in lead acetate group significantly decreased in relation to the control group, but this reduction was not significantly different between the lead acetate plus ascorbic acid group and the control group. Results of this study suggest that ascorbic acid as an antioxidant prevents the lead induced hypertension. This effect may be mediated by inhibition of NOchi oxidation and thereby increasing availability of NO.

  3. Methionine restriction decreases endogenous oxidative molecular damage and increases mitochondrial biogenesis and uncoupling protein 4 in rat brain.

    Science.gov (United States)

    Naudí, Alba; Caro, Pilar; Jové, Mariona; Gómez, José; Boada, Jordi; Ayala, Victoria; Portero-Otín, Manuel; Barja, Gustavo; Pamplona, Reinald

    2007-12-01

    Aging plays a central role in the occurrence of neurodegenerative diseases. Caloric restriction (CR) mitigates oxidative stress by decreasing the rate of generation of endogenous damage, a mechanism that can contribute to the slowing of the aging rate induced by this intervention. Various reports have recently linked methionine to aging, and methionine restriction (MetR) without energy restriction also increases life span. We have thus hypothesized that MetR can be responsible, at least in part, for the decrease in endogenous oxidative damage in CR. In this investigation we subjected male rats to exactly the same dietary protocol of MetR that is known to increase their life span. We have found that MetR: (1) decreases the mitochondrial complex I content and activity, as well as complex III content, while the complex II and IV, the mitochondrial flavoprotein apoptosis-inducing factor (AIF) and ATP content are unchanged; (2) increases the mitochondrial biogenesis factor PGC-1alpha; (3) increases the resistance of brain to metabolic and oxidative stress by increasing mitochondrial uncoupling protein 4 uncoupling protein 4 (UCP4); and (4) decreases mitochondrial oxidative DNA damage and all five different markers of protein oxidation measured and lowers membrane unsaturation in rat brain. No changes were detected for protein amino acid composition. These beneficial MetR-induced changes likely derived from metabolic reprogramming at the cellular and tissue level can play a key role in the protection against aging-associated neurodegenerative disorders.

  4. 40 CFR 721.3700 - Fatty acid, ester with styrenated phenol, ethylene oxide adduct.

    Science.gov (United States)

    2010-07-01

    ... phenol, ethylene oxide adduct. 721.3700 Section 721.3700 Protection of Environment ENVIRONMENTAL..., ethylene oxide adduct. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified generically as fatty acid, ester with styrenated phenol, ethylene oxide...

  5. Disordered Manganese Oxide Nano-powder Prepared by Low-temperature Synthesis Followed by Acid Treatment

    OpenAIRE

    Koyanaka, Hideki; Hata, Toshihiro; IMAMURA, Yuji

    2005-01-01

    Disordered manganese oxide, prepared by low-temperature synthesis followed by acid treatment is introduced. Aggregated nano-powder of disordered manganese oxide was obtained in this method. The disordered manganese oxide is suitable starting material for the preparation of efficient adsorbents for the removal of harmful metals from the environment.

  6. Kinetics and mechanism of N-chlorosaccharin oxidation of malic acid

    OpenAIRE

    Sanjay Kumar Singh; Hari D. Gupta; Mohammad U. Khan; Santosh S. Baghel

    2010-01-01

    Kinetic study of N-chlorosaccharin (NCSA) oxidation of malic acid (MA) in aqueous acetic acid medium in presence of perchloric acid has been investigated. The reactions exhibit first-order dependency in oxidant and HClO4 while order varies from one to zero in substrate. The reactions are acid catalyzed and retarded by the addition of saccharin, a byproduct of reaction. The rate of oxidation decreases with decrease in dielectric constant of the medium. The effect of temperature on the reaction...

  7. Exogenous ascorbic acid increases resistance to salt of Silybum ...

    African Journals Online (AJOL)

    The detrimental effects of salt water were ameliorated by application of 100 ppm ascorbic acid (vitamin C). The inductive role of vitamin was associated with the improvement of seed germination, growth, plant water status, carotenoids, endogenous ascorbic acid and antioxidant enzyme activities. Moreover, vitamin C alone ...

  8. Increased brain fatty acid uptake in metabolic syndrome

    DEFF Research Database (Denmark)

    Karmi, Anna; Iozzo, Patricia; Viljanen, Antti

    2010-01-01

    To test whether brain fatty acid uptake is enhanced in obese subjects with metabolic syndrome (MS) and whether weight reduction modifies it.......To test whether brain fatty acid uptake is enhanced in obese subjects with metabolic syndrome (MS) and whether weight reduction modifies it....

  9. Ghrelin and orotic acid increased in subclinical mastitis.

    Science.gov (United States)

    Karatas, F; Aydin, S; Kaygusuzoglu, E; Yildiz, H; Erulas, F A; Ozkan, Y

    2008-07-01

    Hormone ghrelin and orotic acid accelerate wound healing as well as controlling inflammation and immunity. We have, therefore, investigated the serum and milk levels of ghrelin and orotic acid in dairy cows with (n = 21) or without (n = 21) subclinical mastitis. Acylated and des-acylated ghrelin as well as orotic acid concentration were detected by using high performance liquid chromatography (HPLC). The results revealed that ghrelin level in milk and serum was significantly higher in dairy cows with subclinical mastitis than that of dairy cows without subclinical mastitis. This was also the case when the orotic acid concentrations in dairy cows with subclinical mastitis were compared with those dairy cows without subclinical mastitis. In conclusion, ghrelin and orotic acid occur in particularly high concentrations in subclinical mastitis, and might, therefore, be required in greater amounts for tissue repair and may be also used as a indicator for subclinical mastitis.

  10. Natural resistance to ascorbic acid induced oxidative stress is mainly mediated by catalase activity in human cancer cells and catalase-silencing sensitizes to oxidative stress

    Science.gov (United States)

    2012-01-01

    Background Ascorbic acid demonstrates a cytotoxic effect by generating hydrogen peroxide, a reactive oxygen species (ROS) involved in oxidative cell stress. A panel of eleven human cancer cell lines, glioblastoma and carcinoma, were exposed to serial dilutions of ascorbic acid (5-100 mmol/L). The purpose of this study was to analyse the impact of catalase, an important hydrogen peroxide-detoxifying enzyme, on the resistance of cancer cells to ascorbic acid mediated oxidative stress. Methods Effective concentration (EC50) values, which indicate the concentration of ascorbic acid that reduced the number of viable cells by 50%, were detected with the crystal violet assay. The level of intracellular catalase protein and enzyme activity was determined. Expression of catalase was silenced by catalase-specific short hairpin RNA (sh-RNA) in BT-20 breast carcinoma cells. Oxidative cell stress induced apoptosis was measured by a caspase luminescent assay. Results The tested human cancer cell lines demonstrated obvious differences in their resistance to ascorbic acid mediated oxidative cell stress. Forty-five percent of the cell lines had an EC50 > 20 mmol/L and fifty-five percent had an EC50 ascorbic acid was observed. To study the possible protective role of catalase on the resistance of cancer cells to oxidative cell stress, the expression of catalase in the breast carcinoma cell line BT-20, which cells were highly resistant to the exposure to ascorbic acid (EC50: 94,9 mmol/L), was silenced with specific sh-RNA. The effect was that catalase-silenced BT-20 cells (BT-20 KD-CAT) became more susceptible to high concentrations of ascorbic acid (50 and 100 mmol/L). Conclusions Fifty-five percent of the human cancer cell lines tested were unable to protect themselves against oxidative stress mediated by ascorbic acid induced hydrogen peroxide production. The antioxidative enzyme catalase is important to protect cancer cells against cytotoxic hydrogen peroxide

  11. Natural resistance to ascorbic acid induced oxidative stress is mainly mediated by catalase activity in human cancer cells and catalase-silencing sensitizes to oxidative stress

    Directory of Open Access Journals (Sweden)

    Klingelhoeffer Christoph

    2012-05-01

    against oxidative stress mediated by ascorbic acid induced hydrogen peroxide production. The antioxidative enzyme catalase is important to protect cancer cells against cytotoxic hydrogen peroxide. Silenced catalase expression increased the susceptibility of the formerly resistant cancer cell line BT-20 to oxidative stress.

  12. Alteration of oxidative phosphorylation as a possible mechanism of the antifungal action of p-coumaric acid against Botrytis cinerea.

    Science.gov (United States)

    Morales, J; Mendoza, L; Cotoras, M

    2017-10-01

    The aim of this study was to analyse the mechanism of action of p-coumaric acid against isolate B05·10 of Botrytis cinerea. For this purpose, the effect of this compound on cell membrane, cell wall and oxidative phosphorylation was determined. Induction of oxidative stress triggered by this compound was also studied. p-coumaric acid showed antifungal effect on the mycelial growth. Additionally, the compound was able to retard the germination of Botrytis cinerea conidia. The mechanism of action of this compound was analysed using fluorescent probes. p-Coumaric acid did not affect the integrity of cell wall and plasmatic membrane and neither produced oxidative stress. Finally, it was shown that the compound produced an increase in oxygen consumption. p-coumaric acid performs as a mitochondrial uncoupler in B. cinerea. Its role as an uncoupler of oxidative phosphorylation could be explained to its acidic, nonpolar and planar characteristics. These structural and chemical characteristics would favour ability of p-coumaric acid to pass through cellular membranes. Plant secondary metabolites can be used as an alternative way to control phytopathogenic fungi. The knowledge of the action mechanism of these compounds can contribute to design modified molecules with higher antifungal activity. © 2017 The Society for Applied Microbiology.

  13. Markers of Increased Cardiovascular Risk in Postmenopausal Women: Focus on Oxidized-LDL and HDL Subpopulations

    Science.gov (United States)

    Mascarenhas-Melo, Filipa; Sereno, José; Teixeira-Lemos, Edite; Rocha-Pereira, Petronila; Teixeira, Frederico; Reis, Flávio

    2013-01-01

    Objective. To evaluate the effect of gender and menopause in cardiovascular risk (CVR) in a healthy population based on both classical and nontraditional markers. Methods. 56 men and 68 women (48 pre- and 20 postmenopause) were enrolled in the study. The following markers were analyzed: blood pressure (BP), body mass index (BMI), waist circumference (WC), glucose, total cholesterol (total-c), triglycerides (TGs), low-density lipoprotein cholesterol (LDL-c), oxidized-LDL (Ox-LDL), HDL-c and subpopulations, paraoxonase-1 activity, hsCRP, uric acid, tumor necrosis factor alpha (TNF-α), adiponectin, vascular endothelial growth factor (VEGF), and intercellular adhesion molecular 1 (ICAM1). Results. Relative to the women, men present significantly increased BMI, WC, BP, glucose, total-c, TGs, LDL-c, Ox-LDL, uric acid, and TNF-α and reduced adiponectin and total and large HDL-c. The protective profile of women is lost after menopause with a significantly increased BMI, WC, BP, glucose, LDL-c, Ox-LDL, hsCRP, and VEGF and decreased total and large HDL-c. Significant correlations were found in women population and in postmenopausal women between Ox-LDL and total, large, and small HDL-c and between TNF-α and total, large, and small HDL-c, LDL-c, and Ox-LDL. Conclusions. Men present higher CVR than women who lost protection after menopause, evidenced by nontraditional markers, including Ox-LDL and HDL subpopulations. PMID:24167352

  14. Markers of Increased Cardiovascular Risk in Postmenopausal Women: Focus on Oxidized-LDL and HDL Subpopulations

    Directory of Open Access Journals (Sweden)

    Filipa Mascarenhas-Melo

    2013-01-01

    Full Text Available Objective. To evaluate the effect of gender and menopause in cardiovascular risk (CVR in a healthy population based on both classical and nontraditional markers. Methods. 56 men and 68 women (48 pre- and 20 postmenopause were enrolled in the study. The following markers were analyzed: blood pressure (BP, body mass index (BMI, waist circumference (WC, glucose, total cholesterol (total-c, triglycerides (TGs, low-density lipoprotein cholesterol (LDL-c, oxidized-LDL (Ox-LDL, HDL-c and subpopulations, paraoxonase-1 activity, hsCRP, uric acid, tumor necrosis factor alpha (TNF-α, adiponectin, vascular endothelial growth factor (VEGF, and intercellular adhesion molecular 1 (ICAM1. Results. Relative to the women, men present significantly increased BMI, WC, BP, glucose, total-c, TGs, LDL-c, Ox-LDL, uric acid, and TNF-α and reduced adiponectin and total and large HDL-c. The protective profile of women is lost after menopause with a significantly increased BMI, WC, BP, glucose, LDL-c, Ox-LDL, hsCRP, and VEGF and decreased total and large HDL-c. Significant correlations were found in women population and in postmenopausal women between Ox-LDL and total, large, and small HDL-c and between TNF-α and total, large, and small HDL-c, LDL-c, and Ox-LDL. Conclusions. Men present higher CVR than women who lost protection after menopause, evidenced by nontraditional markers, including Ox-LDL and HDL subpopulations.

  15. Mechanisms of Oxidative Damage in Multiple Sclerosis and Neurodegenerative Diseases: Therapeutic Modulation via Fumaric Acid Esters

    Directory of Open Access Journals (Sweden)

    Ralf Gold

    2012-09-01

    Full Text Available Oxidative stress plays a crucial role in many neurodegenerative conditions such as Alzheimer’s disease, amyotrophic lateral sclerosis and Parkinson’s as well as Huntington’s disease. Inflammation and oxidative stress are also thought to promote tissue damage in multiple sclerosis (MS. Recent data point at an important role of anti-oxidative pathways for tissue protection in chronic-progressive MS, particularly involving the transcription factor nuclear factor (erythroid-derived 2-related factor 2 (Nrf2. Thus, novel therapeutics enhancing cellular resistance to free radicals could prove useful for MS treatment. Here, fumaric acid esters (FAE are a new, orally available treatment option which had already been tested in phase II/III MS trials demonstrating beneficial effects on relapse rates and magnetic resonance imaging markers. In vitro, application of dimethylfumarate (DMF leads to stabilization of Nrf2, activation of Nrf2-dependent transcriptional activity and abundant synthesis of detoxifying proteins. Furthermore, application of FAE involves direct modification of the inhibitor of Nrf2, Kelch-like ECH-associated protein 1. On cellular levels, the application of FAE enhances neuronal survival and protects astrocytes against oxidative stress. Increased levels of Nrf2 are detected in the central nervous system of DMF treated mice suffering from experimental autoimmune encephalomyelitis (EAE, an animal model of MS. In EAE, DMF ameliorates the disease course and improves preservation of myelin, axons and neurons. Finally, Nrf2 is also up-regulated in the spinal cord of autopsy specimens from untreated patients with MS, probably as part of a naturally occurring anti-oxidative response. In summary, oxidative stress and anti-oxidative pathways are important players in MS pathophysiology and constitute a promising target for future MS therapies like FAE.

  16. Increased oxidation-related glutathionylation and carbonic anhydrase activity in endometriosis.

    Science.gov (United States)

    Andrisani, Alessandra; Donà, Gabriella; Brunati, Anna Maria; Clari, Giulio; Armanini, Decio; Ragazzi, Eugenio; Ambrosini, Guido; Bordin, Luciana

    2014-06-01

    permeability and adhesion molecule expression, thus contributing to ongoing inflammation. Due to their main cellular functions--delivery of O2 from lung to tissue and removal of CO2 from tissue to lung--red blood cells (RBC) are exposed to oxidative stress. Carbon dioxide in tissue capillaries diffuses into red cells, where it is rapidly hydrated by the action of cytosolic carbonic anhydrase. Analysis of the oxidation status of endometriotic RBC membranes showed a high content of glutathionylated proteins, indicating pre-existing oxidation-related alterations. The increase in glutathionylated proteins was correlated to increased carbonic anhydrase activity in endometriotic RBC compared with healthy controls. Carbonic anhydrase is a family of metalloenzymes involved in many physiological processes such as acid-base homeostasis, respiration, carbon dioxide and ion transport, and bone resorption, and in the regulation of ureagenesis, gluconeogenesis, lipogenesis and tumourigenesis. Due to the potential implication of carbonic anhydrase activation in many pathologies, such as glaucoma, hypertension, obesity and infections, carbonic anhydrase activity should be closely monitored in endometriosis to prevent possible complications and/or worsening of related conditions. Copyright © 2014 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  17. In vivo protective effect of betulinic acid on dexamethasone induced thymocyte apoptosis by reducing oxidative stress.

    Science.gov (United States)

    Yi, Jine; Zhu, Ruocen; Wu, Jianping; Wu, Jing; Xia, Wei; Zhu, Lijuan; Jiang, Weiwei; Xiang, Siting; Tan, Zhuliang

    2016-02-01

    Dexamethasone (Dex), a synthetic glucocorticoid, is strictly controlled for use due to its serious side effects, including immune suppression. Betulinic acid (BA), an antioxidant prepared from the white birch, exhibits immunomodulation properties. To assess the implications and investigate the mechanisms of BA-elicited immunomodulation, we hypothesized that Dex induced thymocyte apoptosis via oxidative stress could be lessened by BA. Mice were given oral doses of BA (0.25, 0.5, and 1.0mg/kg) daily for 14 days, and induced oxidative stress by giving a single dose of Dex intraperitoneal at the dosage of 25mg/kg body weight 8h after the last administration of BA. Dex administration alone significantly decreased antioxidant enzyme activities, while significantly increased reactive oxygen species (ROS) production, lipid peroxidation, mitochondrial dysfunctions, caspase-3 activation and cellular apoptosis. However, pretreatment with BA dose-dependently mitigated Dex-induced oxidative damage after 14 days of feeding. In addition to ROS scavenging activity in Dex-induced thymocyte, BA administration decreased lipid peroxidation, up-regulated antioxidant enzymes, restored mitochondrial function, increased Bcl-2 expression but reduced Bax expression, inhibited caspase-3 activation, and improved cell survival. These findings reveal a protective capability of BA against Dex-induced cell death by reducing oxidative stress via mitochondrial mediated signal pathway which could be the potential mechanism underlying BA-elicited immunomodulation. Copyright © 2015 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  18. Decreased expression of adipose CD36 and FATP1 are associated with increased plasma nonesterified fatty acids during prolonged fasting in northern elephant seal pups (Mirounga angustirostris)

    Science.gov (United States)

    The northern elephant seal undergoes a 2-3 month post-weaning fast during which it depends primarily on the oxidation of fatty acids to meet its energetic demands. The concentration of plasma free fatty acids (FFA) increases and is associated with the development of insulin resistance in late-fasted...

  19. Composition effects of FePt alloy nanoparticles on the electro-oxidation of formic acid.

    Science.gov (United States)

    Chen, Wei; Kim, Jaemin; Sun, Shouheng; Chen, Shaowei

    2007-10-23

    The catalytic activities of FexPt100-x alloy nanoparticles at different compositions (x=10, 15, 42, 54, 58, and 63) in the electro-oxidation of formic acid have been investigated by using cyclic voltammetry (CV), chronoamperometry, and electrochemical impedance spectroscopy (EIS). It was observed that the electrocatalytic performance was strongly dependent on the FePt particle composition. In chronoamperometric measurements, the alloy particles at x approximately 50 showed the highest steady-state current density among the catalysts under study and maintained the best long-term stability. In addition, on the basis of the anodic peak current density, onset potentials, and the ratios of the anodic peak current density to the cathodic peak current density in CV studies, the catalytic activity for HCOOH oxidation was found to decrease in the order of Fe42Pt58>Fe54Pt46 approximately Fe58Pt42>Fe15Pt85>Fe10Pt90>Fe63Pt37. That is, within the present experimental context, the alloy nanoparticles at x approximately 50 appeared to exhibit the maximum electrocatalytic activity and stability with optimal tolerance to CO poisoning. Consistent responses were also observed in electrochemical impedance spectroscopic measurements. For the alloy nanoparticles that showed excellent tolerance to CO poisoning, the impedance in the Nyquist plots was found to change sign from positive to negative with increasing electrode potential, suggesting that the electron-transfer kinetics evolved from resistive to pseudoinductive and then to inductive characters. However, for the nanoparticles that were heavily poisoned by adsorbed CO species during formic acid oxidation, the impedance was found to be confined to the first quadrant at all electrode potentials. The present work highlights the influence of the molecular composition of Pt-based alloy electrocatalysts on the performance of formic acid electro-oxidation, an important aspect in the design of bimetal electrocatalysts in fuel cell

  20. Urinary markers of nucleic acid oxidation and cancer in type 2 diabetes.

    Science.gov (United States)

    Broedbaek, Kasper; Siersma, Volkert; Henriksen, Trine; Weimann, Allan; Petersen, Morten; Andersen, Jon T; Jimenez-Solem, Espen; Hansen, Lars J; Henriksen, Jan Erik; Bonnema, Steen J; de Fine Olivarius, Niels; Friis, Søren; Poulsen, Henrik E

    2015-01-01

    We investigated whether urinary markers of nucleic acid oxidation are associated with an increased risk of cancer in type 2 diabetes patients. Urine samples from 1381 newly diagnosed diabetes patients were assayed for the oxidatively modified guanine nucleosides 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydroguanosine (8-oxoGuo). Cox proportional hazards regression was used to examine the relationship between the urinary markers and cancer incidence. The crude analyses showed an association between overall cancer and urinary excretion of the RNA oxidation marker 8-oxoGuo (unadjusted hazard ratio for cancer per natural log increase in 8-oxoGuo 1.35 [95% CI, 1.01-1.81]), however, in the adjusted analyses, no significant associations between 8-oxodG or 8-oxoGuo and overall cancer were found. For site-specific cancers 8-oxodG was associated with breast cancer in the crude analyses (unadjusted hazard ratio for breast cancer per natural log increase in 8-oxodG was 2.37 [95% CI, 1.07-5.26]), although the association was attenuated in the adjusted analyses (sex- and age-adjusted hazard ratio 2.15 [95% CI, 0.92-5.02] and multivariate adjusted hazard ratio1.98 [95% CI, 0.95-4.10]). Urinary excretion of the nucleic acid oxidation markers 8-oxodG and 8-oxoGuo at the time of diagnosis was not associated with cancer overall in type 2 diabetes patients. For site-specific cancers, risk elevations were seen for breast cancer (8-oxodG). These findings should be examined in future and larger studies. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  1. Ocean acidification increases fatty acids levels of larval fish

    National Research Council Canada - National Science Library

    Díaz-Gil, Carlos; Catalán, Ignacio A; Palmer, Miquel; Faulk, Cynthia K; Fuiman, Lee A

    2015-01-01

    Rising levels of anthropogenic carbon dioxide in the atmosphere are acidifying the oceans and producing diverse and important effects on marine ecosystems, including the production of fatty acids (FAs...

  2. Oxidative Decarboxylation of Levulinic Acid by Silver(I/Persulfate

    Directory of Open Access Journals (Sweden)

    Yan Gong

    2011-03-01

    Full Text Available The oxidative decarboxylation of levulinic acid (LA by silver(I/persulfate [Ag(I/S2O82−] has been investigated in this paper. The effects of buffer solution, initial pH value, time and temperature and dosages of Ag(I/S2O82− on the decarboxylation of LA were examined in batch experiments and a reaction scheme was proposed on basis of the reaction process. The experimental results showed that a solution of NaOH-KH2PO4 was comparatively suitable for the LA decarboxylation reaction by silver(I/persulfate. Under optimum conditions (temperature 160 °C, pH 5.0, and time 0.5 h, the rate of LA conversion in NaOH-KH2PO4 solutions with an initial concentration of 0.01 mol LA reached 70.2%, 2-butanone (methyl ethyl ketone was the single product in the gas phase and the resulted molar yield reached 44.2%.

  3. Hydrogen oxidation on gold electrode in perchloric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Sustersic, M.G.; Almeida, N.V.; Von Mengershausen, A.E. [Facultad de Ingenieria y Ciencias Economico Sociales, Universidad Nacional de San Luis, 25 de Mayo N 384, 5730 Villa Mercedes, San Luis (Argentina)

    2010-06-15

    The aim of this research is to study the interface gold/perchloric acid solution in presence of hydrogen. The reactive is generated by H{sup +} ion reduction and by saturating the electrolyte with the gaseous H{sub 2}. No evidence of H{sub 2} dissociative adsorption is found. In special conditions, a strongly adsorbed layer is formed from the atoms diffusing from inside of the metal. The mass transport occurs in three ways: the diffusion of H atoms inwards, the diffusion of H atoms back to the surface and the dissolved H{sub 2} diffusion from the bulk electrolyte to the surface. When dissolved H{sub 2} reacts, the reaction is kinetically controlled when the H{sub 2} partial pressure is high, and it is diffusionally controlled when the reactive partial pressure is low. Above 0.7 V, (measured vs. RHE), the (100) plane surface reconstruction lifts, and the rate determining step is the H diffusion towards inside of the metal, and the current suddenly falls. The Hydrogen redox reaction on gold shows reversibility with respect to the potential when the reactives are the H diffusing outwards of the metal and the H{sup +} ion present in the electrolyte. However, the absolute current values of oxidation and reduction are different because the reactive sources are different. (author)

  4. Increased ophthalmic acid production is supported by amino acid catabolism under fasting conditions in mice.

    Science.gov (United States)

    Kobayashi, Sho; Lee, Jaeyong; Takao, Toshifumi; Fujii, Junichi

    2017-09-23

    Glutathione (GSH) plays pivotal roles in antioxidation and detoxification. The transsulfuration pathway, in conjunction with methionine metabolism, produces equimolar amounts of cysteine (Cys) and 2-oxobutyric acid (2OB). The resulting 2OB is then converted into 2-aminobutyric acid (2AB) by a transaminase and is utilized as a substitute for Cys by the GSH-synthesizing machinery to produce ophthalmic acid (OPT). By establishing a method for simultaneously measuring Cys, GSH, and OPT by liquid chromatography-mass spectrometry, we found that fasting causes an elevation in OPT levels in the liver and blood plasma, even though the levels of Cys and GSH are decreased. Autophagy was activated, but the levels of GSH/OPT-synthesizing enzymes remained unchanged. After 6 h of fasting, the mice were given 1% 2AB and/or 5% glucose in the drinking water for an additional 24 h and the above metabolites analyzed. 2AB administration caused an increase in OPT levels, and, when glucose was co-administered with 2AB, the levels of OPT were elevated further but GSH levels were decreased somewhat. These results suggest that, while Cys is utilized for glyconeogenesis under fasting conditions, reaching levels that were insufficient for the synthesis of GSH, 2OB was preferentially converted to 2AB via amino acid catabolism and was utilized as a building block for OPT. Thus the consumption of Cys and the parallel elevation of 2AB under fasting conditions appeared to force γ-glutamylcysteine synthetase to form γ-glutamyl-2AB, despite the fact that the enzyme has a higher Km value for 2AB than Cys. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Evaluation of oxidative stress in autism: defective antioxidant enzymes and increased lipid peroxidation.

    Science.gov (United States)

    Meguid, Nagwa A; Dardir, Ahmed A; Abdel-Raouf, Ehab R; Hashish, Adel

    2011-10-01

    Autism is a neurodevelopmental disorder of childhood with poorly understood etiology and pathology. This pilot study aims to evaluate the levels of antioxidant enzymes, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and levels of malondialdehyde (MDA), a marker of lipid peroxidation, in Egyptian autistic children. Autism is a neurodevelopmental disorder of childhood with poorly understood etiology and pathology. The present study included 20 children with autism diagnosed by DSM-IV-TR criteria and Childhood Autism Rating Scale. Controls included 25 age-matched healthy children. Cases were referred to Outpatient Clinic of Children with Special Needs Department, National Research Center, Cairo, Egypt. We compared levels of SOD, GSH-Px, and MDA in children with autism and controls. In children less than 6 years of age, levels of SOD, and GSH-Px were significantly lower in autistic children compared with their controls, while MDA was significantly higher among patients than controls. In children older than 6 years, there was no significant difference in any of these values between cases and controls. We concluded that children with autism are more vulnerable to oxidative stress in the form of increased lipid peroxidation and deficient antioxidant defense mechanism especially at younger children. We highlight that autistic children might benefit from antioxidants supplementation coupled with polyunsaturated fatty acids. Moreover, early assessment of antioxidant status would have better prognosis as it may decrease the oxidative stress before inducing more irreversible brain damage.

  6. The Protective Effect of Lipoic Acid on Selected Cardiovascular Diseases Caused by Age-Related Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Beata Skibska

    2015-01-01

    Full Text Available Oxidative stress is considered to be the primary cause of many cardiovascular diseases, including endothelial dysfunction in atherosclerosis and ischemic heart disease, hypertension, and heart failure. Oxidative stress increases during the aging process, resulting in either increased reactive oxygen species (ROS production or decreased antioxidant defense. The increase in the incidence of cardiovascular disease is directly related to age. Aging is also associated with oxidative stress, which in turn leads to accelerated cellular senescence and organ dysfunction. Antioxidants may help lower the incidence of some pathologies of cardiovascular diseases and have antiaging properties. Lipoic acid (LA is a natural antioxidant which is believed to have a beneficial effect on oxidative stress parameters in relation to diseases of the cardiovascular system.

  7. Hydrogen Sulfide Increases Nitric Oxide Production and Subsequent S-Nitrosylation in Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Ping-Ho Chen

    2014-01-01

    Full Text Available Hydrogen sulfide (H2S and nitric oxide (NO, two endogenous gaseous molecules in endothelial cells, got increased attention with respect to their protective roles in the cardiovascular system. However, the details of the signaling pathways between H2S and NO in endothelia cells remain unclear. In this study, a treatment with NaHS profoundly increased the expression and the activity of endothelial nitric oxide synthase. Elevated gaseous NO levels were observed by a novel and specific fluorescent probe, 5-amino-2-(6-hydroxy-3-oxo-3H-xanthen-9-ylbenzoic acid methyl ester (FA-OMe, and quantified by flow cytometry. Further study indicated an increase of upstream regulator for eNOS activation, AMP-activated protein kinase (AMPK, and protein kinase B (Akt. By using a biotin switch, the level of NO-mediated protein S-nitrosylation was also enhanced. However, with the addition of the NO donor, NOC-18, the expressions of cystathionine-γ-lyase, cystathionine-β-synthase, and 3-mercaptopyruvate sulfurtransferase were not changed. The level of H2S was also monitored by a new designed fluorescent probe, 4-nitro-7-thiocyanatobenz-2-oxa-1,3-diazole (NBD-SCN with high specificity. Therefore, NO did not reciprocally increase the expression of H2S-generating enzymes and the H2S level. The present study provides an integrated insight of cellular responses to H2S and NO from protein expression to gaseous molecule generation, which indicates the upstream role of H2S in modulating NO production and protein S-nitrosylation.

  8. Oxidation of Tetracaine Hydrochloride by Chloramine-B in Acid Medium: Kinetic Modeling

    Directory of Open Access Journals (Sweden)

    Jayachamarajapura Pranesh Shubha

    2014-01-01

    Full Text Available Tetracaine hydrochloride (TCH is one of the potent local anaesthetics. A kinetic study of oxidation of tetracaine hydrochloride by sodium N-chlorobenzenesulfonamide (chloramine-B or CAB has been carried in HClO4 medium at 303 K. The rate shows first-order dependence on [CAB]o, shows fractional–order dependence on [substrate]o, and is self-governing on acid concentration. Decrease of dielectric constant of the medium, by adding methanol, increased the rate. Variation of ionic strength and addition of benzenesulfonamide or NaCl have no significant effect on the rate. The reaction was studied at different temperatures and the activation parameters have been evaluated. The stoichiometry of the reaction was found to be 1 : 5 and the oxidation products were identified by spectral analysis. The conjugate free acid C6H5SO2NHCl of CAB is postulated as the reactive oxidizing species. The observed results have been explained by plausible mechanism and the related rate law has been deduced.

  9. Protective effect of alpha-lipoic acid in methotrexate-induced ovarian oxidative injury and decreased ovarian reserve in rats.

    Science.gov (United States)

    Soylu Karapinar, Oya; Pinar, Neslihan; Özcan, Oğuzhan; Özgür, Tümay; Dolapçıoğlu, Kenan

    2017-08-01

    To determine whether the possible oxidative effect of methotrexate (Mtx) on ovary and to evaluate the effectiveness of alpha lipoic acid (ALA), which may be useful in many oxidative stress models. Thirty-two female Wistar-albino rats were randomly divided into four groups; control group, alpha lipoic acid group (ALA 100 mg/kg, 10 days), multiple dose Mtx group (Mtx 1 mg/kg 1, 3, 5, 7 days) and Mtx and ALA group (Mtx 1 mg/kg 1, 3, 5, 7 days and ALA 100 mg/kg, 10 days). Serum total antioxidant status (TAS), total oxidant status (TOS) and oxidative stress index (OSI), tumor necrosis factor-alpha (TNF-α), tissue malondialdehyde (MDA) and activities of glutathione peroxidase (GSH-Px) and catalase (CAT) and anti-Mullerian hormone (AMH) and total ovarian follicle count were evaluated. Mtx administration caused a significant decrease in TAS, a significant increase in TOS and OSI, a significant increase in MDA levels and a decrease in GSH-Px and CAT activity. Moreover the proinflammatory cytokine (TNF-α) was increased in the Mtx group. And AMH values and total follicle count were significantly decreased in Mtx group. However, ALA treatment reversed biochemical results and AMH levels and total follicle count. Alpha lipoic acid ameliorates methotrexate induced oxidative damage of ovarian in rats.

  10. Cupric oxide nanowires assembled by nanoparticles in situ with enhancing electrocatalytic oxidation of ascorbic acid

    Science.gov (United States)

    Wang, Chuanxi; Liu, Jie; Huang, Xing; Wang, Huanhuan; Zheng, Youdan; Lin, Li; Wang, Siyu; Chen, Song; Jin, Yong

    2014-02-01

    CuO nanowires are facilely fabricated on the surface of AgCuZn alloy in situ by direct oxidation and partial reduction procedures, which shows an improved electrocatalytic activity toward ascorbic acid oxidation. The morphology shows the nanowires are assembled by CuO nanoparticles and we consider the process that the unordered spheres convert to ordered wires is due to the reduction of [1 1 0] and [ 1 bar    1    1 ] crystal planes in CuO. Moreover, the prepared modified electrode displays a high sensitivity of 1660 μA cm-2 mM-1, wide linear range from 0.1 μM to 3.1 mM and a low detection limit of 0.095 μmol (signal/noise = 3). Further, the sensor is also tested for anti-interferences and real samples determination, exhibiting distinguished selectivity, accuracy, and recovery. Such excellent properties are owing to the special structure of the synthesized CuO that would provide more specific surface area and enhanced activity compared with common nanowires. Hence, this work of fabricating CuO nanowires assembled by CuO nanoparticles with high performance might supply a way for facile obtain more electrochemical sensor in this structure.

  11. Kinetics and mechanism of the oxidation of some neutral and acidic ...

    Indian Academy of Sciences (India)

    The oxidation of eleven amino acids by tetrabutylammonium tribromide (TBATB) in aqueous acetic acid results in the formation of the corresponding carbonyl compounds and ammonia. The reaction is first order with respect to TBATB. Michaelis-Menten type kinetics is observed with some of the amino acids while others ...

  12. The Biochemistry and Physiology of Mitochondrial Fatty Acid β-Oxidation and Its Genetic Disorders

    NARCIS (Netherlands)

    Houten, Sander M.; Violante, Sara; Ventura, Fatima V.; Wanders, Ronald J. A.

    2016-01-01

    Mitochondrial fatty acid β-oxidation (FAO) is the major pathway for the degradation of fatty acids and is essential for maintaining energy homeostasis in the human body. Fatty acids are a crucial energy source in the postabsorptive and fasted states when glucose supply is limiting. But even when

  13. Hydrogen Peroxide Cycling in Acidic Geothermal Environments and Potential Implications for Oxidative Stress

    Science.gov (United States)

    Mesle, M.; Beam, J.; Jay, Z.; Bodle, B.; Bogenschutz, E.; Inskeep, W.

    2014-12-01

    Hydrogen peroxide (H2O2) may be produced in natural waters via photochemical reactions between dissolved oxygen, organic carbon and light. Other reactive oxygen species (ROS) such as superoxide and hydroxyl radicals are potentially formed in environments with high concentrations of ferrous iron (Fe(II), ~10-100 μM) by reaction between H2O2 and Fe(II) (i.e., Fenton chemistry). Thermophilic archaea and bacteria inhabiting acidic iron-oxide mats have defense mechanisms against both extracellular and intracellular peroxide, such as peroxiredoxins (which can degrade H2O2) and against other ROS, such as superoxide dismutases. Biological cycling of H2O2 is not well understood in geothermal ecosystems, and geochemical measurements combined with molecular investigations will contribute to our understanding of microbial response to oxidative stress. We measured H2O2 and other dissolved compounds (Fe(II), Fe(III), H2S, O2), as well as photon flux, pH and temperature, over time in surface geothermal waters of several acidic springs in Norris Geyser Basin, Yellowstone National Park, WY (Beowulf Spring and One Hundred Spring Plain). Iron-oxide mats were sampled in Beowulf Spring for on-going analysis of metatranscriptomes and RT-qPCR assays of specific stress-response gene transcription (e.g., superoxide dismutases, peroxiredoxins, thioredoxins, and peroxidases). In situ analyses show that H2O2 concentrations are lowest in the source waters of sulfidic systems (ca. 1 μM), and increase by two-fold in oxygenated waters corresponding to Fe(III)-oxide mat formation (ca. 2 - 3 μM). Channel transects confirm increases in H2O2 as a function of oxygenation (distance). The temporal dynamics of H2O2, O2, Fe(II), and H2S in Beowulf geothermal waters were also measured during a diel cycle, and increases in H2O2 were observed during peak photon flux. These results suggest that photochemical reactions may contribute to changes in H2O2. We hypothesize that increases in H2O2 and O2

  14. Hydroxycitric acid ameliorates inflammation and oxidative stress in mouse models of multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Mahdi Goudarzvand

    2016-01-01

    Full Text Available Hydroxycitric acid (HCA is derived primarily from the Garcinia plant and is widely used for its anti-inflammatory effects. Multiple sclerosis can cause an inflammatory demyelination and axonal damage. In this study, to validate the hypothesis that HCA exhibits therapeutic effects on multiple sclerosis, we established female C57BL/6 mouse models of multiple sclerosis, i.e., experimental autoimmune encephalomyelitis, using Complete Freund′s Adjuvant (CFA emulsion containing myelin oligodendrocyte glycoprotein (35-55. Treatment with HCA at 2 g/kg/d for 3 weeks obviously improved the symptoms of nerve injury of experimental autoimmune encephalomyelitis mice, decreased serum interleulin-6, tumor necrosis factor alpha, nitric oxide, and malondialdehyde levels, and increased superoxide dismutase and glutathione reductase activities. These findings suggest that HCA exhibits neuroprotective effects on multiple sclerosis-caused nerve injury through ameliorating inflammation and oxidative stress.

  15. Hydroxycitric acid ameliorates inflammation and oxidative stress in mouse models of multiple sclerosis

    Science.gov (United States)

    Goudarzvand, Mahdi; Afraei, Sanaz; Yaslianifard, Somaye; Ghiasy, Saleh; Sadri, Ghazal; Kalvandi, Mustafa; Alinia, Tina; Mohebbi, Ali; Yazdani, Reza; Azarian, Shahin Khadem; Mirshafiey, Abbas; Azizi, Gholamreza

    2016-01-01

    Hydroxycitric acid (HCA) is derived primarily from the Garcinia plant and is widely used for its anti-inflammatory effects. Multiple sclerosis can cause an inflammatory demyelination and axonal damage. In this study, to validate the hypothesis that HCA exhibits therapeutic effects on multiple sclerosis, we established female C57BL/6 mouse models of multiple sclerosis, i.e., experimental autoimmune encephalomyelitis, using Complete Freund's Adjuvant (CFA) emulsion containing myelin oligodendrocyte glycoprotein (35–55). Treatment with HCA at 2 g/kg/d for 3 weeks obviously improved the symptoms of nerve injury of experimental autoimmune encephalomyelitis mice, decreased serum interleulin-6, tumor necrosis factor alpha, nitric oxide, and malondialdehyde levels, and increased superoxide dismutase and glutathione reductase activities. These findings suggest that HCA exhibits neuroprotective effects on multiple sclerosis-caused nerve injury through ameliorating inflammation and oxidative stress. PMID:27904492

  16. Preparation and Properties of Chitosan-Graft Acid)/graphene Oxide Nanocompostie Hydrogels

    Science.gov (United States)

    Huang, Yiwan; Zeng, Ming; Xu, Qingyu; Fan, Liren

    2013-07-01

    A series of chitosan-graft-poly(acrylic acid)/graphene oxide nanocomposite hydrogels were synthesized by in situ radical polymerization. The effects of graphene oxide (GO) content on the chemical structures and morphologies of the hydrogels were investigated. Meanwhile, swelling properties, mechanical properties, as well as salt- and pH- sensitive behaviors were also evaluated. Due to the good interactions between GO and polymer chains, only a few GO loadings could affect the morphologies of the hydrogels significantly, resulting in the formation of porous network structure. Although the swelling ratios decreased with increasing the amount of GO sheets, the composite hydrogels showed a marked improvement of their mechanical strength. The composite hydrogels also exhibited salt- and pH- sensitive behaviors. Therefore, this study provided a novel strategy to fabricate the porous hydrogels that have the promising applications in biomedical area.

  17. Involvement of Oxidative Stress and Inflammation in Liver Injury Caused by Perfluorooctanoic Acid Exposure in Mice

    Directory of Open Access Journals (Sweden)

    Bei Yang

    2014-01-01

    Full Text Available Perfluorooctanoic acid (PFOA is widely present in the environment and has been reported to induce hepatic toxicity in animals and humans. In this study, mice were orally administered different concentrations of PFOA (2.5, 5, or 10 mg/kg/day. Histological examination showed that the exposure to PFOA for 14 consecutive days led to serious hepatocellular injury and obvious inflammatory cell infiltration. In addition, malondialdehyde formation and hydrogen peroxide generation, indicators of oxidative stress, were significantly induced by PFOA treatment in the liver of mice. Furthermore, hepatic levels of interleukin-6, cyclooxygenase-2, and C-reactive protein, markers of inflammatory response, were markedly increased by exposure to PFOA in mice. These results demonstrated that PFOA-induced hepatic toxicity may be involved in oxidative stress and inflammatory response in mice.

  18. Ascorbic acid protects lipids in human plasma and low-density lipoprotein against oxidative damage

    Energy Technology Data Exchange (ETDEWEB)

    Frei, B. (Department of Nutrition, Harvard School of Public Health, Boston, MA (Unites States))

    1991-12-01

    The authors exposed human blood plasma and low-density lipoprotein (LDL) to many different oxidative challenges and followed the temporal consumption of endogenous antioxidants in relation to the initiation of oxidative damage. Under all types of oxidizing conditions, ascorbic acid completely protects lipids in plasma and LDL against detectable peroxidative damage as assessed by a specific and highly sensitive assay for lipid peroxidation. Ascorbic acid proved to be superior to the other water-soluble plasma antioxidants bilirubin, uric acid, and protein thiols as well as to the lipoprotein-associated antioxidants alpha-tocopherol, ubiquinol-10, lycopene, and beta-carotene. Although these antioxidants can lower the rate of detectable lipid peroxidation, they are not able to prevent its initiation. Only ascorbic acid is reactive enough to effectively intercept oxidants in the aqueous phase before they can attack and cause detectable oxidative damage to lipids.

  19. Impact of support oxide acidity in Pt-catalyzed HMF hydrogenation in alcoholic medium

    DEFF Research Database (Denmark)

    Al-Shamery, Katharina; Ly, Nhu; Chan-Thaw, Carine E.

    2017-01-01

    –zirconia and silica–niobia, confirming the peculiar acidity of Nb-oxide compounds in polar liquids: Colloidal spherical platinum nanoparticles were synthesized and then deposited (1 wt%) on the oxide supports. The obtained metallic nanophases were studied in the reduction of 5-hydroxymethylfurfural (HMF) to valuable......Abstract: Silica and three mixed silica oxides (silica–alumina, silica–niobia, and silica–zirconia) with nominally 5 wt% of the added element (Al, Nb and Zr) were prepared and used as supports for dispersing monometallic Pt-nanoparticles. The presence of the second oxide component on the silica......, respectively. The acid site density of silica–alumina was the highest compared with the other oxides; in general, an important decrease of acid sites density was determined in methanol. The order of the effective acidity in methanol was different from that determined in cyclohexane only for silica...

  20. Importance of relative humidity in the oxidative ageing of organic aerosols: case study of the ozonolysis of maleic acid aerosol

    Directory of Open Access Journals (Sweden)

    P. J. Gallimore

    2011-12-01

    Full Text Available Many important atmospheric aerosol processes depend on the chemical composition of the aerosol, e.g. water uptake and particle cloud interactions. Atmospheric ageing processes, such as oxidation reactions, significantly and continuously change the chemical composition of aerosol particles throughout their lifetime. These ageing processes are often poorly understood. In this study we utilize an aerosol flow tube set up and an ultra-high resolution mass spectrometer to explore the effect of relative humidity (RH in the range of <5–90% on the ozonolysis of maleic acid aerosol which is employed as model organic aerosol system. Due to the slow reaction kinetics relatively high ozone concentrations of 160–200 ppm were used to achieve an appreciable degree of oxidation of maleic acid. The effect of oxidative ageing on the hygroscopicity of maleic acid particles is also investigated using an electrodynamic balance and thermodynamic modelling. RH has a profound effect on the oxidation of maleic acid particles. Very little oxidation is observed at RH < 50% and the only observed reaction products are glyoxylic acid and formic acid. In comparison, when RH > 50% there are about 15 oxidation products identified. This increased oxidation was observed even when the particles were exposed to high humidities long after a low RH ozonolysis reaction. This result might have negative implications for the use of water as an extraction solvent for the analysis of oxidized organic aerosols. These humidity-dependent differences in the composition of the ozonolyzed aerosol demonstrate that water is both a key reactant in the oxidation scheme and a determinant of particle phase and hence diffusivity. The measured chemical composition of the processed aerosol is used to model the hygroscopic growth, which compares favourably with water uptake results from the electrodynamic balance measurements. A reaction mechanism is presented which takes into account the RH dependent

  1. Transcript and metabolite alterations increase ganoderic acid content in Ganoderma lucidum using acetic acid as an inducer.

    Science.gov (United States)

    Ren, Ang; Li, Xiong-Biao; Miao, Zhi-Gang; Shi, Liang; Jaing, Ai-Liang; Zhao, Ming-Wen

    2014-12-01

    Acetic acid at 5-8 mM increased ganoderic acid (GA) accumulation in Ganoderma lucidum. After optimization by the response surface methodology, the GA content reached 5.5/100 mg dry weight, an increase of 105% compared with the control. The intermediate metabolites of GA biosynthesis, lanosterol and squalene also increased to 47 and 15.8 μg/g dry weight, respectively, in response to acetic acid. Acetic acid significantly induced transcription levels of sqs, lano, hmgs and cyp51 in the GA biosynthesis pathway. An acetic acid-unregulated acetyl coenzyme A synthase (acs) gene was selected from ten candidate homologous acs genes. The results indicate that acetic acid alters the expression of genes related to acetic acid assimilation and increases GA biosynthesis and the metabolic levels of lanosterol, squalene and GA-a, thereby resulting in GA accumulation.

  2. Oxidative stability of lipids and cholesterol in salame Milano, coppa and Parma ham: dietary supplementation with vitamin E and oleic acid.

    Science.gov (United States)

    Zanardi, E; Novelli, E; Ghiretti, G P; Chizzolini, R

    2000-06-01

    An investigation has been carried out on the effect of dietary supplementation with vitamin E and oleic acid on oxidative stability of Italian representative pork products. Fatty acid composition of deposited fat was modified in the oil supplemented groups with negative effects on fat firmness. Oil supplementation significantly increased vitamin E content of muscles, as well. Oxidative stability of fat, evaluated by TBARS and cholesterol oxides, has not shown significant differences between dietary treatments but, although the differences were not significant, the tendency was sufficiently clear, especially in salame Milano, towards a lower oxidation level in vitamin E enriched meat. Cholesterol oxidation was found to vary in general around 0.1% of total cholesterol and the only cholesterol oxides observed were 7β-hydroxycholesterol, 5,6α-epoxycholesterol and 7-ketocholesterol. Aldehydes content and distribution appeared to be linked, firstly, to the specific processing technology of the product and, secondly, to the changed fatty acid composition.

  3. Kinetics of Oxidation of Cobalt(III Complexes of a Acids by Hydrogen Peroxide in the Presence of Surfactants

    Directory of Open Access Journals (Sweden)

    Mansur Ahmed

    2008-01-01

    Full Text Available Hydrogen peroxide oxidation of pentaamminecobalt(III complexes of α-hydroxy acids at 35°C in micellar medium has been attempted. In this reaction the rate of oxidation shows first order kinetics each in [cobalt(III] and [H2O2]. Hydrogen peroxide induced electron transfer in [(NH35 CoIII-L]2+ complexes of α-hydroxy acids readily yields 100% of cobalt(II with nearly 100% of C-C bond cleavage products suggesting that it behaves mainly as one equivalent oxidant in micellar medium. With unbound ligand also it behaves only as C-C cleavage agent rather than C-H cleavage agent. With increasing micellar concentration an increase in the rate is observed.

  4. Increased expression of fatty acid synthase provides a survival advantage to colorectal cancer cells via upregulation of cellular respiration.

    Science.gov (United States)

    Zaytseva, Yekaterina Y; Harris, Jennifer W; Mitov, Mihail I; Kim, Ji Tae; Butterfield, D Allan; Lee, Eun Y; Weiss, Heidi L; Gao, Tianyan; Evers, B Mark

    2015-08-07

    Fatty acid synthase (FASN), a lipogenic enzyme, is upregulated in colorectal cancer (CRC). Increased de novo lipid synthesis is thought to be a metabolic adaptation of cancer cells that promotes survival and metastasis; however, the mechanisms for this phenomenon are not fully understood. We show that FASN plays a role in regulation of energy homeostasis by enhancing cellular respiration in CRC. We demonstrate that endogenously synthesized lipids fuel fatty acid oxidation, particularly during metabolic stress, and maintain energy homeostasis. Increased FASN expression is associated with a decrease in activation of energy-sensing pathways and accumulation of lipid droplets in CRC cells and orthotopic CRCs. Immunohistochemical evaluation demonstrated increased expression of FASN and p62, a marker of autophagy inhibition, in primary CRCs and liver metastases compared to matched normal colonic mucosa. Our findings indicate that overexpression of FASN plays a crucial role in maintaining energy homeostasis in CRC via increased oxidation of endogenously synthesized lipids. Importantly, activation of fatty acid oxidation and consequent downregulation of stress-response signaling pathways may be key adaptation mechanisms that mediate the effects of FASN on cancer cell survival and metastasis, providing a strong rationale for targeting this pathway in advanced CRC.

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

    Science.gov (United States)

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

    2008-03-26

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

  6. Kolaviron and L-Ascorbic Acid Attenuate Chlorambucil-Induced Testicular Oxidative Stress in Rats

    Directory of Open Access Journals (Sweden)

    Ebenezer Tunde Olayinka

    2014-01-01

    Full Text Available Chlorambucil (4-[4-[bis(2-chloroethylamino]phenyl]butanoic acid is an alkylating agent, indicated in chronic lymphocytic leukaemia. Kolaviron (KV, a biflavonoid complex from Garcinia kola, and L-ascorbic acid (AA are known to protect against oxidative damage in vivo. This study evaluates the protective capacity of KV and AA on chlorambucil-induced oxidative stress in the testes of rat. Twenty male Wistar rats (180–200 g were randomized into four groups: I: control, II: chlorambucil (0.2 mg/kg b.w., III: 0.2 mg/kg chlorambucil and 100 mg/kg KV, and IV: 0.2 mg/kg chlorambucil and 100 mg/kg AA. After 14 days of treatments, results indicated that chlorambucil caused significant reduction (P<0.05 in testicular vitamin C and glutathione by 32% and 39%, respectively, relative to control. Similarly, activities of testicular GST, SOD, and CAT reduced significantly by 48%, 47%, and 49%, respectively, in chlorambucil-treated rats relative to control. Testicular MDA and activities of ALP, LDH, and ACP were increased significantly by 53%, 51%, 64%, and 70%, respectively, in the chlorambucil-treated rat. However, cotreatment with KV and AA offered protection and restored the levels of vitamin C, GSH, and MDA as well as SOD, CAT, GST, ACP, ALP, and LDH activities. Overall, kolaviron and L-ascorbic acid protected against chlorambucil-induced damage in the testes of the rat.

  7. Ferulic Acid Orchestrates Anti-Oxidative Properties of Danggui Buxue Tang, an Ancient Herbal Decoction: Elucidation by Chemical Knock-Out Approach.

    Directory of Open Access Journals (Sweden)

    Amy G W Gong

    Full Text Available Ferulic acid, a phenolic acid derived mainly from a Chinese herb Angelica Sinensis Radix (ASR, was reported to reduce the formation of free radicals. Danggui Buxue Tang (DBT, a herbal decoction composing of Astragali Radix (AR and ASR, has been utilized for more than 800 years in China having known anti-oxidative property. Ferulic acid is a major active ingredient in DBT; however, the role of ferulic acid within the herbal mixture has not been resolved. In order to elucidate the function of ferulic acid within this herbal decoction, a ferulic acid-depleted herbal decoction was created and named as DBTΔfa. The anti-oxidative properties of chemically modified DBT decoction were systemically compared in cultured H9C2 rat cardiomyoblast cell line. The application of DBT and DBTΔfa into the cultures showed functions in (i decreasing the reactive oxygen species (ROS formation, detected by laser confocal; (ii increasing of the activation of Akt; (iii increasing the transcriptional activity of anti-oxidant response element (ARE; and (iv increasing the expressions of anti-oxidant enzymes, i.e. NQO1 and GCLM. In all scenario, the aforementioned anti-oxidative properties of DBTΔfa in H9C2 cells were significantly reduced, as compared to authentic DBT. Thus, ferulic acid could be an indispensable chemical in DBT to orchestrate multi-components of DBT as to achieve maximal anti-oxidative functions.

  8. Morphology, thermal, mechanical, and barrier properties of graphene oxide/poly(lactic acid) nanocomposite films

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seong Woo; Choi, Hyun Muk [Kyonggi University, Suwon (Korea, Republic of)

    2016-01-15

    To improve the physical and gas barrier properties of biodegradable poly(lactic acid) (PLA) film, two graphene nanosheets of highly functionalized graphene oxide (0.3 wt% to 0.7 wt%) and low-functionalized graphene oxide (0.5 wt%) were incorporated into PLA resin via solution blending method. Subsequently, we investigated the effects of material parameters such as loading level and degree of functionalization for the graphene nanosheets on the morphology and properties of the resultant nanocomposites. The highly functionalized graphene oxide (GO) caused more exfoliation and homogeneous dispersion in PLA matrix as well as more sustainable suspensions in THF, compared to low-functionalized graphene oxide (LFGO). When loaded with GO from 0.3 wt% to 0.7 wt%, the glass transition temperature, degree of crystallinity, tensile strength and modulus increased steadily. The GO gave rise to more pronounced effect in the thermal and mechanical reinforcement, relative to LFGO. In addition, the preparation of fairly transparent PLA-based nanocomposite film with noticeably improved barrier performance achieved only when incorporated with GO up to 0.7wt%. As a result, GO may be more compatible with hydrophilic PLA resin, compared to LFGO, resulting in more prominent enhancement of nanocomposites properties.

  9. Arsenite induced oxidative damage in mouse liver is associated with increased cytokeratin 18 expression

    Energy Technology Data Exchange (ETDEWEB)

    Gonsebatt, M.E. [UNAM, Ciudad Universitaria, Dept. Medicina Genomica y Toxicologia Ambiental, Instituto de Investigaciones Biomedicas, Mexico (Mexico); Razo, L.M. del; Sanchez-Pena, L.C. [Seccion de Toxicologia, CINVESTAV, Mexico (Mexico); Cerbon, M.A. [Facultad de Quimica, UNAM, Departamento de Biologia, Mexico (Mexico); Zuniga, O.; Ramirez, P. [Facultad de Estudios Superiores Cuautitlan, UNAM, Laboratorio de Toxicologia Celular, Coordinacion General de Estudios de Posgrado e Investigacion, Cuautitlan Izcalli, Estado de Mexico (Mexico)

    2007-09-15

    Cytokeratins (CK) constitute a family of cytoskeletal intermediate filament proteins that are typically expressed in epithelial cells. An abnormal structure and function are effects that are clearly related to liver diseases as non-alcoholic steatohepatitis, cirrhosis and hepatocellular carcinoma. We have previously observed that sodium arsenite (SA) induced the synthesis of CK18 protein and promotes a dose-related disruption of cytoplasmic CK18 filaments in a human hepatic cell line. Both abnormal gene expression and disturbance of structural organization are toxic effects that are likely to cause liver disease by interfering with normal hepatocyte function. To investigate if a disruption in the CK18 expression pattern is associated with arsenite liver damage, we investigated CK18 mRNA and protein levels in liver slices treated with low levels of SA. Organotypic cultures were incubated with 0.01, 1 and 10 {mu}M of SA in the absence and presence of N-acetyl cysteine (NAC). Cell viability and inorganic arsenic metabolism were determined. Increased expression of CK18 was observed after exposure to SA. The addition of NAC impeded the oxidative effects of SA exposure, decreasing the production of thiobarbituric acid-reactive substances and significantly diminishing the up regulation of CK18 mRNA and protein. Liver arsenic levels correlated with increased levels of mRNA. Mice treated with intragastric single doses of 2.5 and 5 mg/kg of SA showed an increased expression of CK18. Results suggest that CK18 expression may be a sensible early biomarker of oxidative stress and damage induced by arsenite in vitro and in vivo. Then, during SA exposure, altered CK expression may compromise liver function. (orig.)

  10. Ursolic acid ameliorates oxidative stress, inflammation and fibrosis in diabetic cardiomyopathy rats.

    Science.gov (United States)

    Wang, Xu-Tao; Gong, Yan; Zhou, Bin; Yang, Jun-Jie; Cheng, Yin; Zhao, Jin-Guo; Qi, Min-You

    2017-11-16

    Diabetic cardiomyopathy is a major and severe cardiovascular complication of diabetes mellitus. Ursolic acid, a pentacyclic triterpene compound widespread in fruits and plants, performs a variety of pharmacological activities including lowering blood glucose, anti-oxidation, anti-inflammation and anti-fibrosis. Our present study aimed to investigate the cardioprotective effects of ursolic acid on diabetic cardiomyopathy rats and uncover its underlying mechanism. Diabetes mellitus was induced by a single injection of STZ-only (40 mg/ kg, i.v.) in male SD rats. Animals were divided into three groups (n=10): control group (normal saline, i.g.), diabetic group (normal saline, i.g.) and diabetic+ursolic acid group (35 mg/kg UA + normal saline, i.g.). Rats were administered for 8 weeks from 5th to 12th week. After the last administration, cardiac function was evaluated; HWI was calculated; FBG, CK, LDH in serum and SOD, MDA in cardiac tissue were detected. HE staining and Masson trichrome staining were employed to observe pathological alterations. Immunohistochemistry and western blotting were taken to determine the expression levels of TNF-α, MCP-1, TGF-β1 and MMP-2 in the heart. The results dramatically showed increased levels of FBG, CK, LDH, MDA and a decreased activity of SOD in diabetic group, in which left ventricular dysfunction, cardiac myocytes hypertrophy, inflammatory cell infiltration and myocardial interstitial fibrosis had also been found. What's more, the expressions of TNF-α, MCP-1 and TGF-β1 were significantly up-regulated and the expression of MMP-2 was markedly down-regulated in myocardium. Interestingly, treatment with ursolic acid remarkably ameliorated these changes. Collectively, our study strongly showed that ursolic acid is capable of improving the cardiac structure and function in STZ-induced diabetic cardiomyopathy rats by attenuating oxidative stress, inflammation and fibrosis. Copyright © 2017 Elsevier Masson SAS. All rights

  11. Oxidation of 2-cys peroxiredoxins in human endothelial cells by hydrogen peroxide, hypochlorous acid, and chloramines.

    Science.gov (United States)

    Stacey, Melissa M; Vissers, Margreet C; Winterbourn, Christine C

    2012-08-01

    Reactive oxygen species released from neutrophils during vascular inflammation could contribute to endothelial dysfunction seen in diseases such as atherosclerosis. Activated neutrophils generate hydrogen peroxide (H(2)O(2)) and hypochlorous acid (HOCl), as well as chloramines that are formed when HOCl reacts with amino compounds. These oxidants preferentially target thiol groups and thiol-containing proteins. The peroxiredoxins (Prxs) are thiol proteins that have high reactivity with H(2)O(2) and may also be sensitive to HOCl and chloramines. We have investigated human umbilical vein endothelial cells and shown that their cytoplasmic (Prx1 and Prx2) and mitochondrial (Prx3) Prxs are oxidized when they are exposed to H(2)O(2), HOCl, or cell-permeable chloramines. H(2)O(2) converted the Prxs to hyperoxidized, inactive forms, with little accumulation of disulfide-linked dimers. The oxidized Prxs were reduced over hours, presumably due to the action of endothelial sulfiredoxin. In contrast to the hyperoxidation seen with H(2)O(2), HOCl and the chloramine derivatives of glycine and ammonia converted the Prxs to disulfide-linked dimers and dimerization was reversed within 10-30 min of oxidant removal. HOCl treatment caused thioredoxin reductase (TrxR) inhibition with no reversal of dimerization. The cytotoxicity of ammonia chloramine was increased when cells were pretreated with H(2)O(2) to hyperoxidize the Prxs, or when the chloramine was added in the presence of the TrxR inhibitor, auranofin. We describe the novel observation that exposure of nucleated cells to inflammatory oxidants results in the accumulation of Prxs in the dimeric form. Endothelial cell Prxs are sensitive targets for neutrophil-derived oxidants and may protect against their damaging effects.

  12. Ferrous iron mediated oxidation of arachidonic acid: studies employing nitroblue tetrazolium (NBT).

    Science.gov (United States)

    Peterson, D A; Gerrard, J M; Rao, G H; Krick, T P; White, J G

    1978-10-01

    The oxidation of arachidonic acid by ferrous sulfate provides a useful model to study the role of iron in lipid oxidation reactions. We have employed nitroblue tetrazolium (NBT) in the present investigation to evaluate the mechanism of this reaction. In the presence of arachidonic acid, Fe +++, and O2, the yellow dye NBT was rapidly reduced to the blue form, NBTH2. The molar ratio of arachidonic acid to Fe++ in this rapid reaction was 1:1, showing an interaction of one fatty acid molecule per iron molecule. Approximately one molecule of NBT was reduced per four molecules of arachidonic acid and Fe++. Reduction of NBT was accompanied by oxidation of Fe++ to Fe+++, suggesting the transfer of four electrons from the Fe++ to NBT to reduce the dye. Arachidonic acid was found to be unchanged when extracted at the end of the reaction, indicating formation of a complex that could dissociate leaving intact arachidonic acid. Evidence for the presence of such a complex which slowly dissociates during the reaction was obtained after longer incubations with small amounts of arachidonic acid. NBT reduction was not inhibited by agents which hydrolyze superoxide, by catalase or by agents which trap hydroxy radicals. We, therefore, propose a model in which NBT traps a radical generated on the arachidonic acid molecule. The proposed model suggests mechanisms for other fatty acid oxidation reactions such as prostaglandin and hydroperoxy fatty acid synthesis.

  13. Oxidative stability of milk drinks containing structured lipids produced from sunflower oil and caprylic acid

    DEFF Research Database (Denmark)

    Timm Heinrich, Maike; Xu, Xuebing; Nielsen, Nina Skall

    2003-01-01

    Milk drinks containing 5% traditional sunflower oil (SO), randomized lipid (RL) or specific structured lipid (SL) (both produced from SO and tricaprylin/caprylic acid) were compared with respect to their particle size, viscosity and oxidative stability during storage. Furthermore, the effect...... of adding potential antioxidants EDTA or gallic acid to the milk drink based on SL was investigated. The lipid type significantly affected the oxidative stability of the milk drinks: Milk drink based on SL oxidized faster than milk drink based on RL or SO. The reduced oxidative stability in the SL milk...

  14. Electrophoretic deposition and electrochemical behavior of novel graphene oxide-hyaluronic acid-hydroxyapatite nanocomposite coatings

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ming; Liu, Qian; Jia, Zhaojun; Xu, Xuchen; Shi, Yuying [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Cheng, Yan, E-mail: chengyan@pku.edu.cn [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Zheng, Yufeng [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871 (China); Xi, Tingfei [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Wei, Shicheng [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Department of Oral and Maxillofacial Surgery, School of Stomatology, Peking University, Beijing 100081 (China)

    2013-11-01

    Novel ternary graphene oxide-hyaluronic acid-hydroxyapatite (GO-HY-HA) nanocomposite coatings were prepared on Ti substrate using anodic electrophoretic deposition (EPD). Hyaluronic acid was employed as charging additive and dispersion agent during EPD. The kinetics and mechanism of the deposition, and the microstructure of the coated samples were investigated using scanning electron microscopy, X-ray diffraction, Raman spectrum, thermo-gravimetric analysis, and microscopic Fourier transform infrared analysis. The results showed that the addition of GO sheets into the HY-HA suspensions could increase the deposition rate and inhibit cracks creation and propagation in the coatings. The corrosion resistant of the resulting samples were evaluated using potentiodynamic polarization method in simulated body fluid, and the GO-HY-HA coatings could effectively improve the anti-corrosion property of the Ti substrate.

  15. Evidence that nitric acid increases relative humidity in low-temperature cirrus clouds.

    Science.gov (United States)

    Gao, R S; Popp, P J; Fahey, D W; Marcy, T P; Herman, R L; Weinstock, E M; Baumgardner, D G; Garrett, T J; Rosenlof, K H; Thompson, T L; Bui, P T; Ridley, B A; Wofsy, S C; Toon, O B; Tolbert, M A; Kärcher, B; Peter, Th; Hudson, P K; Weinheimer, A J; Heymsfield, A J

    2004-01-23

    In situ measurements of the relative humidity with respect to ice (RHi) and of nitric acid (HNO3) were made in both natural and contrail cirrus clouds in the upper troposphere. At temperatures lower than 202 kelvin, RHi values show a sharp increase to average values of over 130% in both cloud types. These enhanced RHi values are attributed to the presence of a new class of HNO3-containing ice particles (Delta-ice). We propose that surface HNO3 molecules prevent the ice/vapor system from reaching equilibrium by a mechanism similar to that of freezing point depression by antifreeze proteins. Delta-ice represents a new link between global climate and natural and anthropogenic nitrogen oxide emissions. Including Delta-ice in climate models will alter simulated cirrus properties and the distribution of upper tropospheric water vapor.

  16. Apparent increase of vitamin C (ascorbic acid) levels in potato ...

    African Journals Online (AJOL)

    Vitamin C (Ascorbic acid) levels in Irish potato (Solanum tuberosum) tubers purchased from shops and open markets in Cardiff, U.K. were determined in the raw, boiled and fried (chips) pieces by 2,6, Dichlorophenolindophenol dye (DCP) method in the laboratory. The chips were prepared in sunflower oil, corn oil and ...

  17. Engineering lactic acid bacteria for increased industrial functionality

    NARCIS (Netherlands)

    Bron, P.A.; Kleerebezem, M.

    2011-01-01

    Based on their spoilage-preventing and flavor-contributing characteristics, lactic acid bacteria (LAB) are employed as starter cultures for the fermentation of foods and feeds. In addition, several specific LAB strains are marketed on basis of their beneficial effects on the consumer's health,

  18. Mixed cultures of Kimchi lactic acid bacteria show increased cell ...

    African Journals Online (AJOL)

    ufuoma

    solo culture, L. sakei 171 was superior in cell growth, lactate production and the release of amino acids .... The bacteria were grown under anaerobic conditions in the MRS broth containing glucose. The medium composition per liter was as follows: (a) 10 g peptone, 10 g beef extract, 5 g yeast extract, 3 g diammonium.

  19. Thermal properties of poly(ethylene oxide)/lauric acid blends. A SSA-DSC study

    Energy Technology Data Exchange (ETDEWEB)

    Pielichowski, Krzysztof; Flejtuch, Kinga [Department of Chemistry and Technology of Polymers, Cracow University of Technology, ul. Warszawska 24, 31-155 Krakow (Poland)

    2006-03-15

    A series of poly(ethylene oxide) (PEO)/lauric acid blends with different compositions has been prepared and characterised by differential scanning calorimetry (DSC) in dynamic mode. It has been found that the enthalpy of melting and crystallisation reaches its highest value for PEO/lauric acid blend (1:1, w/w) which makes this system a promising candidate for thermal energy storage applications. Further studies by step-scan alternating (SSA)-DSC revealed that an increase of the temperature step causes that the average total heating rate is also increasing and the heat flow is characterised by higher values. Reversing component of the heat flow during melting reaches lowest values at highest step (step=1{sup o}) when the re-crystallisation of PEO is hindered. An increase of step generally leads to an increase of the number of non-equilibrium effects and facilitates the activation of kinetic non-reversing processes, hindering the overall crystallisation of PEO. For lauric acid, due to facile crystallisation and self-association, formation of ordered regular structures takes place faster and is influenced by non-reversing processes in higher proportion. (author)

  20. Increased levels of oxidative stress biomarkers in metal oxides nanomaterial-handling workers.

    Science.gov (United States)

    Liou, Saou-Hsing; Chen, Yu-Cheng; Liao, Hui-Yi; Wang, Chien-Jen; Chen, Jhih-Sheng; Lee, Hui-Ling

    2016-11-01

    This study assessed oxidatively damaged DNA and antioxidant enzyme activity in workers occupational exposure to metal oxides nanomaterials. Exposure to TiO2, SiO2, and ITO resulted in significant lower antioxidant enzymes (glutathione peroxidase and superoxide dismutase) and higher oxidative biomarkers 8-hydroxydeoxyguanosine (8-oxodG) than comparison workers. Statistically significant correlations were noted between plasma and urine 8-oxodG, between white blood cells (WBC) and urine 8-oxodG, and between WBC and plasma 8-oxodG. In addition, there were significant negative correlations between WBC 8-oxodG and SOD and between urinary 8-oxodG and GPx levels. The results showed that urinary 8-oxodG may be considered to be better biomarker.

  1. Oxalic acid capped iron oxide nanorods as a sensing platform.

    Science.gov (United States)

    Sharma, Anshu; Baral, Dinesh; Bohidar, H B; Solanki, Pratima R

    2015-08-05

    A label free impedimetric immunosensor has been fabricated using protein bovine serum albumin (BSA) and monoclonal antibodies against Vibrio cholerae (Ab) functionalized oxalic acid (OA) capped iron oxide (Fe3O4) nanorods for V. cholerae detection. The structural and morphological studies of Fe3O4 and OA-Fe3O4, were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and dynamic light scattering (DLS) techniques. The average crystalline size of Fe3O4, OA-Fe3O4 nanorods were obtained as about 29±1 and 39±1nm, respectively. The hydrodynamic radius of nanorods is found as 116nm (OA-Fe3O4) and 77nm (Fe3O4) by DLS measurement. Cytotoxicity of Fe3O4 and OA-Fe3O4 nanorods has been investigated in the presence of human epithelial kidney (HEK) cell line 293 using MTT assay. The cell viability and proliferation studies reveal that the OA-Fe3O4 nanorods facilitate cell growth. The results of electrochemical response studies of the fabricated BSA/Ab/OA-Fe2O3/ITO immunosensor exhibits good linearity in the range of 12.5-500ng mL(-1) with low detection limit of 0.5ng mL(-1), sensitivity 0.1Ωng(-1)ml(-1)cm(-2) and reproducibility more than 11 times. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  2. Swimming training attenuates oxidative damage and increases enzymatic but not non-enzymatic antioxidant defenses in the rat brain.

    Science.gov (United States)

    Nonato, L F; Rocha-Vieira, E; Tossige-Gomes, R; Soares, A A; Soares, B A; Freitas, D A; Oliveira, M X; Mendonça, V A; Lacerda, A C; Massensini, A R; Leite, H R

    2016-09-29

    Although it is well known that physical training ameliorates brain oxidative function after injuries by enhancing the levels of neurotrophic factors and oxidative status, there is little evidence addressing the influence of exercise training itself on brain oxidative damage and data is conflicting. This study investigated the effect of well-established swimming training protocol on lipid peroxidation and components of antioxidant system in the rat brain. Male Wistar rats were randomized into trained (5 days/week, 8 weeks, 30 min; n=8) and non-trained (n=7) groups. Forty-eight hours after the last session of exercise, animals were euthanized and the brain was collected for oxidative stress analysis. Swimming training decreased thiobarbituric acid reactive substances (TBARS) levels (Pbrain non-enzymatic total antioxidant capacity, estimated by FRAP (ferric-reducing antioxidant power) assay (P>0.05). Moreover, the swimming training promoted metabolic adaptations, such as increased maximal workload capacity (Ptraining are key factors in promoting brain resistance. In conclusion, swimming training attenuated oxidative damage and increased enzymatic antioxidant but not non-enzymatic status in the rat brain.

  3. Arsenic-induced oxidative myocardial injury: protective role of arjunolic acid

    Energy Technology Data Exchange (ETDEWEB)

    Manna, Prasenjit; Sinha, Mahua; Sil, Parames C. [Bose Institute, Department of Chemistry, Kolkata, West Bengal (India)

    2008-03-15

    Arsenic, one of the most harmful metalloids, is ubiquitous in the environment. The present study has been carried out to investigate the protective role of a triterpenoid saponin, arjunolic acid (AA) against arsenic-induced cardiac oxidative damage. In the study, NaAsO{sub 2} was chosen as the source of arsenic. The free radical scavenging activity and the effect of AA on the intracellular antioxidant power were determined from its 2,2-diphenyl-1-picryl hydrazyl radical scavenging ability and ferric reducing/antioxidant power assay, respectively. Oral administration of NaAsO{sub 2} at a dose of 10 mg/kg body weight for 2 days caused significant accumulation of arsenic in cardiac tissues of the experimental mice in association with the reduction in cardiac antioxidant enzymes activities, namely superoxide dismutase, catalase, glutathione-S-transferase, glutathione reductase and glutathione peroxidase. Arsenic intoxication also decreased the cardiac glutathione (GSH) and total thiol contents and increased the levels of oxidized glutathione (GSSG), lipid peroxidation end products and protein carbonyl content. Treatment with AA at a dose of 20 mg/kg body weight for 4 days prior to NaAsO{sub 2} intoxication protected the cardiac tissue from arsenic-induced oxidative impairment. In addition to oxidative stress, arsenic administration increased total cholesterol level as well as the reduced high-density lipoprotein cholesterol level in the sera of the experimental mice. AA pretreatment, however, could prevent this hyperlipidemia. Histological studies on the ultrastructural changes in cardiac tissue supported the protective activity of AA also. Combining all, results suggest that AA could protect cardiac tissues against arsenic-induced oxidative stress probably due to its antioxidant property. (orig.)

  4. Dietary olive cake reduces the oxidation of lipids, including cholesterol, in lamb meat enriched in polyunsaturated fatty acids.

    Science.gov (United States)

    Luciano, G; Pauselli, M; Servili, M; Mourvaki, E; Serra, A; Monahan, F J; Lanza, M; Priolo, A; Zinnai, A; Mele, M

    2013-03-01

    Over 40 days, lambs were fed: concentrate (C), concentrate containing 20% linseed (L), concentrate containing 35% olive cake (OC), or concentrate containing 10% linseed and 17% olive cake (OCL). The polyunsaturated fatty acids (PUFA) and peroxidation index (PI) in phospholipids were increased by the L and OCL treatments (P=0.007 and P=0.003, respectively). The OC and OCL diets increased the concentration of tocopherol in muscle (P<0.001). Compared to the OC and OCL diet, the L diet increased fatty acid oxidation, measured as conjugated dienes (CD; P=0.003), peroxides (PV; P<0.001) and TBARS (P=0.002) in minced muscle over 11 days of storage in high-oxygen atmosphere. Also, the L diet increased (P<0.001) the levels cholesterol oxidation products (COPs). In conclusion, feeding olive cake improved the oxidative stability of lamb meat and the combination of olive cake and linseed improved the fatty acid composition of meat without compromising its oxidative stability. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Evaluation of Humic Acid and Tannic Acid Fouling in Graphene Oxide-Coated Ultrafiltration Membranes.

    Science.gov (United States)

    Chu, Kyoung Hoon; Huang, Yi; Yu, Miao; Her, Namguk; Flora, Joseph R V; Park, Chang Min; Kim, Suhan; Cho, Jaeweon; Yoon, Yeomin

    2016-08-31

    Three commercially available ultrafiltration (UF) membranes (poly(ether sulfone), PES) that have nominal molecular weight cut-offs (5, 10, and 30 kDa) were coated with graphene oxide (GO) nanosheets. Field-emission scanning electron microscopy, Fourier-transform infrared spectroscopy, confocal laser scanning microscopy, water contact angle measurements, and X-ray photoelectron spectroscopy were employed to determine the changed physicochemical properties of the membranes after GO coating. The water permeability and single-solute rejection of GO-coated (GOC) membranes for humic acid (HA) molecules were significantly higher by approximately 15% and 55%, respectively, compared to those of pristine UF membranes. However, the GOc membranes for single-solute tannic acid (TA) rejection showed similar trends of higher flux decline versus pristine PES membranes, because the relatively smaller TA molecules were readily adsorbed onto the membrane pores. When the mixed-solute of HA and TA rejection tests were performed, in particular, the adsorbed small TA molecules resulted in irreversible membrane fouling due to cake formation and membrane pore blocking on the membrane surface for the HA molecules. Although both membranes showed significantly higher flux declines for small molecules rejection, the GOc membranes showed better performance than the pristine UF membranes in terms of the rejection of various mixed-solute molecules, due to higher membrane recovery and antifouling capabilities.

  6. Integrating nitric oxide into salicylic acid and jasmonic acid/ ethylene plant defense pathways

    Science.gov (United States)

    Mur, Luis A. J.; Prats, Elena; Pierre, Sandra; Hall, Michael A.; Hebelstrup, Kim H.

    2013-01-01

    Plant defense against pests and pathogens is known to be conferred by either salicylic acid (SA) or jasmonic acid (JA)/ethylene (ET) pathways, depending on infection or herbivore-grazing strategy. It is well attested that SA and JA/ET pathways are mutually antagonistic allowing defense responses to be tailored to particular biotic stresses. Nitric oxide (NO) has emerged as a major signal influencing resistance mediated by both signaling pathways but no attempt has been made to integrate NO into established SA/JA/ET interactions. NO has been shown to act as an inducer or suppressor of signaling along each pathway. NO will initiate SA biosynthesis and nitrosylate key cysteines on TGA-class transcription factors to aid in the initiation of SA-dependent gene expression. Against this, S-nitrosylation of NONEXPRESSOR OF PATHOGENESIS-RELATED PROTEINS1 (NPR1) will promote the NPR1 oligomerization within the cytoplasm to reduce TGA activation. In JA biosynthesis, NO will initiate the expression of JA biosynthetic enzymes, presumably to over-come any antagonistic effects of SA on JA-mediated transcription. NO will also initiate the expression of ET biosynthetic genes but a suppressive role is also observed in the S-nitrosylation and inhibition of S-adenosylmethionine transferases which provides methyl groups for ET production. Based on these data a model for NO action is proposed but we have also highlighted the need to understand when and how inductive and suppressive steps are used. PMID:23818890

  7. Aminolevulinic acid and nitric oxide regulate oxidative defense and secondary metabolisms in canola (Brassica napus L.) under drought stress.

    Science.gov (United States)

    Akram, Nudrat Aisha; Iqbal, Majid; Muhammad, Atta; Ashraf, Muhammad; Al-Qurainy, Fahad; Shafiq, Sidra

    2018-01-01

    To minimize the damaging effects of stresses, plant growth regulators (PGRs) are widely used to sustain the plant life under stress-prone environments. So, a study was carried out to evaluate the response of two canola (Brassica napus L.) cultivars, Dunkeld and Cyclone, to foliar-applied two potential PGRs, nitric oxide (NO) and 5-aminolevulinic acid, under water deficit conditions. In this study, the levels of NO and ALA used were 0.02 and 0.895 mM, respectively. Plants of both canola cultivars were subjected to control (100% field capacity) and water deficit (60% field capacity). Drought stress significantly decreased growth, chlorophyll pigments, relative water contents (RWC), and soluble proteins, while it increased relative membrane permeability (RMP), proline, glycinebetaine (GB), malondialdehyde (MDA), total phenolics, and activities of catalase (CAT) and peroxidase (POD) enzymes in both cultivars. Foliar application of PGRs improved growth, chlorophyll a, GB, total phenolics, CAT activity, and total soluble proteins, while it decreased RMP, MDA, and POD activity in both canola cultivars. Other physio-biochemical attributes such as chlorophyll b, RWC, hydrogen peroxide (H2O2) and proline contents as well as superoxide dismutase (SOD) activity remained unaffected due to application of PGRs. So, the results of the present study suggest that exogenous application of NO and ALA could be useful to enhance the drought tolerance of canola plants by up-regulating the oxidative defense system, osmoprotectant accumulation, and minimizing the lipid peroxidation.

  8. An innovative zinc oxide-coated zeolite adsorbent for removal of humic acid

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lingling, E-mail: lasier_wang@hotmail.com [College of Chemical Engineering and Materials, Quanzhou Normal University, Quanzhou 362000, Fujian (China); Environmental Engineering and Science Program, 705 Engineering Research Center, University of Cincinnati, Cincinnati, OH 45221-0012 (United States); Han, Changseok [ORISE Post-doctoral Fellow, The U.S. Environmental Protection Agency, ORD, NRMRL, STD, CPB, 26 W. Martin Luther King Jr. Drive, Cincinnati, OH 45268 (United States); Nadagouda, Mallikarjuna N. [The U.S. Environmental Protection Agency, ORD, NRMRL, WSWRD, WQMB, 26 W. Martin Luther King Jr. Drive, Cincinnati, OH 45268 (United States); Dionysiou, Dionysios D., E-mail: dionysios.d.dionysiou@uc.edu [Environmental Engineering and Science Program, 705 Engineering Research Center, University of Cincinnati, Cincinnati, OH 45221-0012 (United States); Nireas-International Water Research Centre, School of Engineering, University of Cyprus, PO Box 20537, 1678, Nicosia (Cyprus)

    2016-08-05

    Highlights: • An innovative adsorbent was successfully synthesized to remove humic acid. • The adsorbent possessed high adsorption capacity for humic acid. • The adsorption capacity remarkably increased after an acid modification. • The adsorption capacity was proportional to the amount of ZnO coated on zeolite. • Electrostatic interactions are a major factor at the first stage of the process. - Abstract: Zinc oxide (ZnO)-coated zeolite adsorbents were developed by both nitric acid modification and Zn(NO{sub 3}){sub 2}·6H{sub 2}O functionalization of zeolite 4A. The developed adsorbents were used for the removal of humic acid (HA) from aqueous solutions. The synthesized materials were characterized by porosimetry analysis, scanning electron microscopy, X-Ray diffraction analysis, and high resolution transmission electron microscopy. The maximum adsorption capacity of the adsorbents at 21 ± 1 °C was about 60 mgC g{sup −1}. The results showed that the positive charge density of ZnO-coated zeolite adsorbents was proportional to the amount of ZnO coated on zeolite and thus, ZnO-coated zeolite adsorbents exhibited a greater affinity for negatively charged ions. Furthermore, the adsorption capacity of ZnO-coated zeolite adsorbents increased markedly after acid modification. Adsorption experiments demonstrated ZnO-coated zeolite adsorbents possessed high adsorption capacity to remove HA from aqueous solutions mainly due to strong electrostatic interactions between negative functional groups of HA and the positive charges of ZnO-coated zeolite adsorbents.

  9. Ocean acidification increases fatty acids levels of larval fish

    OpenAIRE

    Díaz-Gil, Carlos; Catalán, Ignacio Alberto; Palmer, Miquel; Faulk, Cynthia K.; Fulman, Lee A.

    2015-01-01

    Rising levels of anthropogenic carbon dioxide in the atmosphere are acidifying the oceans and producing diverse and important effects on marine ecosystems, including the production of fatty acids (FAs) by primary producers and their transfer through food webs. FAs, particularly essential FAs, are necessary for normal structure and function in animals and influence composition and trophic structure of marine food webs. To test the effect of ocean acidification (OA) on the FA composition of fis...

  10. Comparative inhibition studies of enoyl-CoA hydratase 1 and enoyl-CoA hydratase 2 in long-chain fatty acid oxidation.

    Science.gov (United States)

    Wu, Long; Lin, Shuping; Li, Ding

    2008-08-07

    Enoyl-CoA hydratase 1 and enoyl-CoA hydratase 2 in long-chain fatty acid oxidation were comparatively investigated through mechanistic studies for inactivation of the enzymes with methylenecyclopropylformyl-CoA and 3-octynoyl-CoA. Methylenecyclopropylformyl-CoA can inactivate both enzymes, while 3-octynoyl-CoA inactivates enoyl-CoA hydratase 2 only. The study increased our understanding of these two enzymes in fatty acid oxidation.

  11. Enantioselective changes in oxidative stress and toxin release in Microcystis aeruginosa exposed to chiral herbicide diclofop acid

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Jing [School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai 201418 (China); MOE Key Lab of Environmental Remediation and Ecosystem Health, College of Natural Research and Environmental Sciences, Zhejiang University, Hangzhou 310058 (China); Zhang, Ying [Department of Environmental Science, East China Normal University, Shanghai 200241 (China); Chen, Shengwen [School of Urban Development and Environment Engineering, Shanghai Second Polytechnic University, Shanghai 201209 (China); Liu, Chaonan; Zhu, Yongqiang [School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai 201418 (China); Liu, Weiping, E-mail: wliu@zju.edu.cn [MOE Key Lab of Environmental Remediation and Ecosystem Health, College of Natural Research and Environmental Sciences, Zhejiang University, Hangzhou 310058 (China)

    2014-01-15

    Highlights: •The first study on enantioselective oxidative stress and toxin release from Microcystis aeruginosa. •Provide information for the R-enantiomer poses more oxidative stress than the S-enantiomer. •Lifecycle analysis of chiral pollutants needs more attention in environmental assessment. -- Abstract: Enantioselective oxidative stress and toxin release from Microcystis aeruginosa after exposure to the chiral herbicide diclofop acid were investigated. Racemic diclofop acid, R-diclofop acid and S-diclofop acid induced reactive oxygen species (ROS) generation, increased the concentration of malondialdehyde (MDA), enhanced the activity of superoxide dismutase (SOD) and triggered toxin release in M. aeruginosa to varying degrees. The increase in MDA concentration and SOD activity in M. aeruginosa occurred sooner after exposure to diclofop acid than when the cyanobacteria was exposed to either the R- and the S-enantiomer. In addition, enantioselective toxicity of the enantiomers was observed. The R-enantiomer trigged more ROS generation, more SOD activity and more toxin synthesis and release in M. aeruginosa cells than the S-enantiomer. Diclofop acid and its R-enantiomer may collapse the transmembrane proton gradient and destroy the cell membrane through lipid peroxidation and free radical oxidation, whereas the S-enantiomer did not demonstrate such action. R-diclofop acid inhibits the growth of M. aeruginosa in the early stage, but ultimately induced greater toxin release, which has a deleterious effect on the water column. These results indicate that more comprehensive study is needed to determine the environmental safety of the enantiomers, and application of chiral pesticides requires more direct supervision and training. Additionally, lifecycle analysis of chiral pollutants in aquatic system needs more attention to aide in the environmental assessment of chiral pesticides.

  12. Long-term treatment with the pan-PPAR agonist tetradecylthioacetic acid or fish oil is associated with increased cardiac content of n-3 fatty acids in rat

    Directory of Open Access Journals (Sweden)

    Strand Elin

    2012-06-01

    Full Text Available Abstract Background Excess peroxisome proliferator-activated receptor (PPAR stimulation has been associated with detrimental health effects including impaired myocardial function. Recently, supplementation with n-3 polyunsaturated fatty acids (PUFA has been associated with improved left ventricular function and functional capacity in patients with dilated cardiomyopathy. We investigated the long-term effects of the pan-PPAR agonist tetradecylthioacetic acid (TTA and/or high-dose fish oil (FO on cardiac fatty acid (FA composition and lipid metabolism. Male Wistar rats were given one out of four different 25% (w/v fat diets: control diet; TTA diet; FO diet; or diet containing both TTA and FO. Results After 50 weeks n-3 PUFA levels were increased by TTA and FO in the heart, whereas liver levels were reduced following TTA administration. TTA was associated with a decrease in arachidonic acid, increased activities of carnitine palmitoyltransferase II, fatty acyl-CoA oxidase, glycerol-3-phosphate acyltransferase, and fatty acid synthase in the heart. Furthermore, cardiac Ucp3 and Cact mRNA was upregulated. Conclusions Long-term treatment with the pan-PPAR agonist TTA or high-dose FO induced marked changes in PUFA composition and enzymatic activity involved in FA metabolism in the heart, different from liver. Changes included increased FA oxidation and a selective increase in cardiac n-3 PUFA.

  13. Whole-body fat oxidation increases more by prior exercise than overnight fasting in elite endurance athletes.

    Science.gov (United States)

    Andersson Hall, Ulrika; Edin, Fredrik; Pedersen, Anders; Madsen, Klavs

    2016-04-01

    The purpose of this study was to compare whole-body fat oxidation kinetics after prior exercise with overnight fasting in elite endurance athletes. Thirteen highly trained athletes (9 men and 4 women; maximal oxygen uptake: 66 ± 1 mL·min(-1)·kg(-1)) performed 3 identical submaximal incremental tests on a cycle ergometer using a cross-over design. A control test (CON) was performed 3 h after a standardized breakfast, a fasting test (FAST) 12 h after a standardized evening meal, and a postexercise test (EXER) after standardized breakfast, endurance exercise, and 2 h fasting recovery. The test consisted of 3 min each at 30%, 40%, 50%, 60%, 70%, and 80% of maximal oxygen uptake and fat oxidation rates were measured through indirect calorimetry. During CON, maximal fat oxidation rate was 0.51 ± 0.04 g·min(-1) compared with 0.69 ± 0.04 g·min(-1) in FAST (P < 0.01), and 0.89 ± 0.05 g·min(-1) in EXER (P < 0.01). Across all intensities, EXER was significantly higher than FAST and FAST was higher than CON (P < 0.01). Blood insulin levels were lower and free fatty acid and cortisol levels were higher at the start of EXER compared with CON and FAST (P < 0.05). Plasma nuclear magnetic resonance-metabolomics showed similar changes in both EXER and FAST, including increased levels of fatty acids and succinate. In conclusion, prior exercise significantly increases whole-body fat oxidation during submaximal exercise compared with overnight fasting. Already high rates of maximal fat oxidation in elite endurance athletes were increased by approximately 75% after prior exercise and fasting recovery.

  14. Chronic oxidative stress causes increased tau phosphorylation in M17 neuroblastoma cells.

    Science.gov (United States)

    Su, Bo; Wang, Xinglong; Lee, Hyoung-Gon; Tabaton, Massimo; Perry, George; Smith, Mark A; Zhu, Xiongwei

    2010-01-14

    Tau hyperphosphorylation appears to be a critical event leading to abnormal aggregation and disrupted function of tau in affected neurons in Alzheimer's disease (AD). As a prominent early event during AD pathogenesis, oxidative stress is believed to contribute to tau phosphorylation and the formation of neurofibrillary lesions. However, acute oxidative stress has disparate effects on tau phosphorylation. Given the chronic nature of AD, in this study, we aimed to determine the long-term effect of oxidative stress on tau phosphorylation. In this regard, we established a novel in vitro model of chronic oxidative stress through inhibition of glutathione (GSH) synthesis with BSO. We confirmed that these cells were under a chronic mild oxidative stress by looking at oxidative response, the induction of heme oxygenase 1 (HO-1) without neuronal death. Chronic oxidative stress increased levels of tau phosphorylated at PHF-1 epitope (serine 399/404) in a time-dependent manner. Our data further suggest that increased activity of JNK and p38 and decreased activity of PP2A are likely involved in chronic oxidative stress-induced tau phosphorylation. In conclusion we suggest that chronic oxidative stress contributes to increased tau phosphorylation in vitro and could play a critical role in neurofibrillary pathology in vivo. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

  15. An investigation into the surface heterogeneity of nitric acid oxidized carbon fiber

    Energy Technology Data Exchange (ETDEWEB)

    Woodhead, Andrea L., E-mail: andrea.woodhead@csiro.au [CSIRO Manufacturing, Waurn Ponds, Geelong, Victoria 3216 (Australia); Institute for Frontier Materials, Deakin University, Waurn Ponds, Geelong, Victoria 3216 (Australia); Souza, Mandy L. de [Institute for Frontier Materials, Deakin University, Waurn Ponds, Geelong, Victoria 3216 (Australia); Church, Jeffrey S. [CSIRO Manufacturing, Waurn Ponds, Geelong, Victoria 3216 (Australia)

    2017-04-15

    Highlights: • A series of nitric acid treated CFs were produced to explore surface heterogeneity. • Several surface analysis techniques, SEM, XPS, AFM and Raman, were compared. • Raman spectral maps were used to explore chemical effects of the treatments on CF. • These maps provided information at a spatial resolution unattainable by XPS. • CFs subjected to the harshest treatment displayed increased surface heterogeneity. - Abstract: The carbon fiber surface plays a critical role in the performance of carbon fiber composite materials and, thus it is important to have a thorough understanding of the fiber surface. A series of nitric acid treated intermediate modulus carbon fibers with increasing treatment level was prepared and characterized using a range of surface sensitive techniques including Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), X-ray Photoelectron Spectroscopy (XPS) and Raman spectroscopy. The results, which were found to be consistent with increasing treatment levels, were compared to the literature. Raman spectral mapping has been used to investigate the heterogeneity of the carbon fiber surface after nitric acid oxidation. The mapping enabled the effects of surface treatment on carbon fiber to be investigated at a spatial resolution unattainable by XPS and provided chemical structure information not provided by SEM or AFM. The highest level of treatment resulted in the most heterogeneous surface. Raman mapping, while time consuming, can provide valuable information which can lead to an enhanced understanding of the heterogeneity of the carbon fiber surface.

  16. Piper sarmentosum increases nitric oxide production in oxidative stress: a study on human umbilical vein endothelial cells.

    Science.gov (United States)

    Ugusman, Azizah; Zakaria, Zaiton; Hui, Chua Kien; Nordin, Nor Anita Megat Mohd

    2010-07-01

    Nitric oxide produced by endothelial nitric oxide synthase (eNOS) possesses multiple anti-atherosclerotic properties. Hence, enhanced expression of eNOS and increased Nitric oxide levels may protect against the development of atherosclerosis. Piper sarmentosum is a tropical plant with antioxidant and anti-inflammatory activities. This study aimed to investigate the effects of Piper sarmentosum on the eNOS and Nitric oxide pathway in cultured human umbilical vein endothelial cells (HUVECs). HUVECS WERE DIVIDED INTO FOUR GROUPS: control, treatment with 180 microM hydrogen peroxide (H(2)O(2)), treatment with 150 microg/mL aqueous extract of Piper sarmentosum, and concomitant treatment with aqueous extract of PS and H(2)O(2) for 24 hours. Subsequently, HUVECs were harvested and eNOS mRNA expression was determined using qPCR. The eNOS protein level was measured using ELISA, and the eNOS activity and Nitric oxide level were determined by the Griess reaction. Human umbilical vein endothelial cells treated with aqueous extract of Piper sarmentosum showed a marked induction of Nitric oxide. Treatment with PS also resulted in increased eNOS mRNA expression, eNOS protein level and eNOS activity in HUVECs. Aqueous extract of Piper sarmentosum may improve endothelial function by promoting NO production in HUVECs.

  17. Piper sarmentosum increases nitric oxide production in oxidative stress: a study on human umbilical vein endothelial cells

    Directory of Open Access Journals (Sweden)

    Azizah Ugusman

    2010-01-01

    Full Text Available OBJECTIVE: Nitric oxide produced by endothelial nitric oxide synthase (eNOS possesses multiple anti-atherosclerotic properties. Hence, enhanced expression of eNOS and increased Nitric oxide levels may protect against the development of atherosclerosis. Piper sarmentosum is a tropical plant with antioxidant and anti-inflammatory activities. This study aimed to investigate the effects of Piper sarmentosum on the eNOS and Nitric oxide pathway in cultured human umbilical vein endothelial cells (HUVECs. METHODS: HUVECs were divided into four groups: control, treatment with 180 μM hydrogen peroxide (H2O2, treatment with 150 μg/mL aqueous extract of Piper sarmentosum, and concomitant treatment with aqueous extract of PS and H2O2 for 24 hours. Subsequently, HUVECs were harvested and eNOS mRNA expression was determined using qPCR. The eNOS protein level was measured using ELISA, and the eNOS activity and Nitric oxide level were determined by the Griess reaction. RESULTS: Human umbilical vein endothelial cells treated with aqueous extract of Piper sarmentosum showed a marked induction of Nitric oxide. Treatment with PS also resulted in increased eNOS mRNA expression, eNOS protein level and eNOS activity in HUVECs. CONCLUSION: Aqueous extract of Piper sarmentosum may improve endothelial function by promoting NO production in HUVECs.

  18. Simultaneous Electrochemical Detection of Dopamine and Ascorbic Acid Using an Iron Oxide/Reduced Graphene Oxide Modified Glassy Carbon Electrode

    Directory of Open Access Journals (Sweden)

    Teo Peik-See

    2014-08-01

    Full Text Available The fabrication of an electrochemical sensor based on an iron oxide/graphene modified glassy carbon electrode (Fe3O4/rGO/GCE and its simultaneous detection of dopamine (DA and ascorbic acid (AA is described here. The Fe3O4/rGO nanocomposite was synthesized via a simple, one step in-situ wet chemical method and characterized by different techniques. The presence of Fe3O4 nanoparticles on the surface of rGO sheets was confirmed by FESEM and TEM images. The electrochemical behavior of Fe3O4/rGO/GCE towards electrocatalytic oxidation of DA was investigated by cyclic voltammetry (CV and differential pulse voltammetry (DPV analysis. The electrochemical studies revealed that the Fe3O4/rGO/GCE dramatically increased the current response against the DA, due to the synergistic effect emerged between Fe3O4 and rGO. This implies that Fe3O4/rGO/GCE could exhibit excellent electrocatalytic activity and remarkable electron transfer kinetics towards the oxidation of DA. Moreover, the modified sensor electrode portrayed sensitivity and selectivity for simultaneous determination of AA and DA. The observed DPVs response linearly depends on AA and DA concentration in the range of 1–9 mM and 0.5–100 µM, with correlation coefficients of 0.995 and 0.996, respectively. The detection limit of (S/N = 3 was found to be 0.42 and 0.12 µM for AA and DA, respectively.

  19. Increased Production of Fatty Acids and Triglycerides in Aspergillus oryzae by Enhancing Expressions of Fatty Acid Synthesis-Related Genes

    Energy Technology Data Exchange (ETDEWEB)

    Tamano, Koichi; Bruno, Kenneth S.; Karagiosis, Sue A.; Culley, David E.; Deng, Shuang; Collett, James R.; Umemura, Myco; Koike, Hideaki; Baker, Scott E.; Machida, Masa

    2013-01-01

    Microbial production of fats and oils is being developedas a means of converting biomass to biofuels. Here we investigate enhancing expression of enzymes involved in the production of fatty acids and triglycerides as a means to increase production of these compounds in Aspergillusoryzae. Examination of the A.oryzaegenome demonstrates that it contains twofatty acid synthases and several other genes that are predicted to be part of this biosynthetic pathway. We enhancedthe expressionof fatty acid synthesis-related genes by replacing their promoters with thepromoter fromthe constitutively highly expressedgene tef1. We demonstrate that by simply increasing the expression of the fatty acid synthasegenes we successfullyincreasedtheproduction of fatty acids and triglyceridesby more than two fold. Enhancement of expression of the fatty acid pathway genes ATP-citrate lyase and palmitoyl-ACP thioesteraseincreasedproductivity to a lesser extent.Increasing expression ofacetyl-CoA carboxylase caused no detectable change in fatty acid levels. Increases in message level for each gene were monitored usingquantitative real-time RT-PCR. Our data demonstrates that a simple increase in the abundance of fatty acid synthase genes can increase the detectable amount of fatty acids.

  20. Phytanic acid alpha-oxidation in peroxisomal disorders: studies in cultured human fibroblasts

    NARCIS (Netherlands)

    Verhoeven, N. M.; Schor, D. S.; Roe, C. R.; Wanders, R. J.; Jakobs, C.

    1997-01-01

    We studied the alpha-oxidation of phytanic acid in human fibroblasts of controls and patients affected with classical Refsum disease, rhizomelic chondrodysplasia punctata, generalized peroxisomal disorders and peroxisomal bifunctional protein deficiency. Cultured fibroblasts were incubated with

  1. High-efficiency palladium catalysts supported on ppy-modified C60 for formic acid oxidation.

    Science.gov (United States)

    Bai, Zhengyu; Yang, Lin; Guo, Yuming; Zheng, Zhi; Hu, Chuangang; Xu, Pengle

    2011-02-14

    A facile preparation of polypyrrole-modified fullerene supported Pd nanoparticles catalyst is introduced; electrochemical measurements demonstrate that the obtained Pd/ppy-C(60) catalyst shows a good electrocatalytic activity and stability for the oxidation of formic acid.

  2. Oxidation of hepatic carnitine palmitoyl transferase-I (CPT-I impairs fatty acid beta-oxidation in rats fed a methionine-choline deficient diet.

    Directory of Open Access Journals (Sweden)

    Gaetano Serviddio

    Full Text Available There is growing evidence that mitochondrial dysfunction, and more specifically fatty acid β-oxidation impairment, is involved in the pathophysiology of non-alcoholic steatohepatitis (NASH. The goal of the present study was to achieve more understanding on the modification/s of carnitinepalmitoyltransferase-I (CPT-I, the rate-limiting enzyme of the mitochondrial fatty acid β-oxidation, during steatohepatitis. A high fat/methionine-choline deficient (MCD diet, administered for 4 weeks, was used to induce NASH in rats.We demonstrated that CPT-I activity decreased, to the same extent, both in isolated liver mitochondria and in digitonin-permeabilized hepatocytes from MCD-diet fed rats.At the same time, the rate of total fatty acid oxidation to CO(2 and ketone bodies, measured in isolated hepatocytes, was significantly lowered in treated animals when compared to controls. Finally, an increase in CPT-I mRNA abundance and protein content, together with a high level of CPT-I protein oxidation was observed in treated rats. A posttranslational modification of rat CPT-I during steatohepatitis has been here discussed.

  3. Black soldier fly as dietary protein source for broiler quails: meat proximate composition, fatty acid and amino acid profile, oxidative status and sensory traits.

    Science.gov (United States)

    Cullere, M; Tasoniero, G; Giaccone, V; Acuti, G; Marangon, A; Dalle Zotte, A

    2017-07-24

    In the perspective of improving the sustainability of meat production, insects have been rapidly emerging as innovative feed ingredient for some livestock species, including poultry. However, at present, there is still limited knowledge regarding the quality and sensory traits of the derived meat. Therefore, the present study tested the effect of a partial substitution of soya bean meal and oil with defatted black soldier fly (Hermetia illucens) larvae meal (H) in the diet for growing broiler quails (Coturnix coturnix japonica) on meat proximate composition, cholesterol, amino acid and mineral contents, fatty acid profile, oxidative status and sensory characteristics. To this purpose, three dietary treatments were designed: a control diet (C) and two diets (H1 and H2) corresponding to 10% and 15% H inclusion levels, respectively, were fed to growing quails from 10 to 28 days of age. At 28 days of age, quails were slaughtered and breast meat was used for meat quality evaluations. Meat proximate composition, cholesterol content and oxidative status remained unaffected by H supplementation as well as its sensory characteristics and off-flavours perception. Differently, with increasing the dietary H inclusion, the total saturated fatty acid and total monounsaturated fatty acid proportions raised to the detriment of the polyunsaturated fatty acid fraction thus lowering the healthiness of the breast meat. The H2 diet increased the contents of aspartic acid, glutamic acid, alanine, serine, tyrosine and threonine thus further enhancing the biological value of the meat protein. As a direct result of the dietary content of Ca and P, the meat of quails fed with the highest H level, displayed the highest Ca and the lowest P values. Therefore, meat quality evaluations confirmed H to be a promising insect protein source for quails. The only potential drawback from feeding H to broiler quails regarded the fatty acid profile of the meat, therefore requiring further research

  4. Patients with systemic vasculitis have increased levels of autoantibodies against oxidized LDL

    NARCIS (Netherlands)

    Swets, BP; Brouwer, DAJ; Tervaert, JWC

    Oxidation of low density lipoprotein (LDL) is considered to play an important role in the development of atherosclerosis and increased levels of autoantibodies against oxidized LDL have been found in patients with various manifestations of atherosclerosis. Patients with vasculitis are prone to the

  5. Oxidized fatty acid analysis by charge-switch derivatization, selected reaction monitoring, and accurate mass quantitation.

    Science.gov (United States)

    Liu, Xinping; Moon, Sung Ho; Mancuso, David J; Jenkins, Christopher M; Guan, Shaoping; Sims, Harold F; Gross, Richard W

    2013-11-01

    A highly sensitive, specific, and robust method for the analysis of oxidized metabolites of linoleic acid (LA), arachidonic acid (AA), and docosahexaenoic acid (DHA) was developed using charge-switch derivatization, liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI MS/MS) with selected reaction monitoring (SRM) and quantitation by high mass accuracy analysis of product ions, thereby minimizing interferences from contaminating ions. Charge-switch derivatization of LA, AA, and DHA metabolites with N-(4-aminomethylphenyl)-pyridinium resulted in a 10- to 30-fold increase in ionization efficiency. Improved quantitation was accompanied by decreased false positive interferences through accurate mass measurements of diagnostic product ions during SRM transitions by ratiometric comparisons with stable isotope internal standards. The limits of quantitation were between 0.05 and 6.0pg, with a dynamic range of 3 to 4 orders of magnitude (correlation coefficient r(2)>0.99). This approach was used to quantitate the levels of representative fatty acid metabolites from wild-type (WT) and iPLA2γ(-/-) mouse liver identifying the role of iPLA2γ in hepatic lipid second messenger production. Collectively, these results demonstrate the utility of high mass accuracy product ion analysis in conjunction with charge-switch derivatization for the highly specific quantitation of diminutive amounts of LA, AA, and DHA metabolites in biologic systems. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Nicotine Induces Podocyte Apoptosis through Increasing Oxidative Stress.

    Directory of Open Access Journals (Sweden)

    Xiqian Lan

    Full Text Available Cigarette smoking plays an important role in the progression of chronic kidney disease (CKD. Nicotine, one of the major components of cigarette smoking, has been demonstrated to increase proliferation of renal mesangial cells. In this study, we examined the effect of nicotine on podocyte injury.To determine the expression of nicotinic acetylcholine receptors (nAChR subunits in podocytes, cDNAs and cell lysate of cultured human podocytes were used for the expression of nAChR mRNAs and proteins, respectively; and mouse renal cortical sections were subjected to immunofluorescant staining. We also studied the effect of nicotine on podocyte nephrin expression, reactive oxygen species (ROS generation (via DCFDA loading followed by fluorometric analysis, proliferation, and apoptosis (morphologic assays. We evaluated the effect of nicotine on podocyte downstream signaling including phosphorylation of ERK1/2, JNK, and p38 and established causal relationships by using respective inhibitors. We used nAChR antagonists to confirm the role of nicotine on podocyte injury.Human podocytes displayed robust mRNA and protein expression of nAChR in vitro studies. In vivo studies, mice renal cortical sections revealed co-localization of nAChRs along with synaptopodin. In vitro studies, nephrin expression in podocyte was decreased by nicotine. Nicotine stimulated podocyte ROS generation; nonetheless, antioxidants such as N-acetyl cysteine (NAC and TEMPOL (superoxide dismutase mimetic agent inhibited this effect of nicotine. Nicotine did not modulate proliferation but promoted apoptosis in podocytes. Nicotine enhanced podocyte phosphorylation of ERK1/2, JNK, and p38, and their specific inhibitors attenuated nicotine-induced apoptosis. nAChR antagonists significantly suppressed the effects of nicotine on podocyte.Nicotine induces podocyte apoptosis through ROS generation and associated downstream MAPKs signaling. The present study provides insight into molecular

  7. Japanese butterbur (Petasites japonicus) leaves increase hepatic oxidative stress in male rats.

    Science.gov (United States)

    Han, Kyu-Ho; Sekikawa, Mitsuo; Shimada, Ken-Ichiro; Lee, Chi-Ho; Hashimoto, Naoto; Fukushima, Michihiro

    2012-01-01

    We investigated the adverse effects of Japanese butterbur leaves (Petasites japonicus, Compositae) in male F344/DuCrj rats. The rats were fed a control diet or a treatment diet containing 5% butterbur leaf powder for 4 weeks. No differences were observed in body weight gain, food intake or feed efficiency between treatments, but relative liver weight in the butterbur group was significantly higher than that of the control group. In addition, thiobarbituric acid reactive substances (TBARs) and glutathione levels in the serum and liver of the butterbur group were higher than those of the control group. Hepatic glutathione reductase and glutathione S-transferase activities and mRNA expression in the butterbur leaf group were higher than in the control group. Furthermore, hepatic cytochrome 2E1 mRNA expression was higher than in the control group. In vitro, an acetone extract of the butterbur leaf powder showed the strongest increase in TBARs level in a hepatic homogenate through 4 d. Our findings suggest that feeding 5% butterbur leaf powder to rats can cause adverse effects by increasing oxidative stress.

  8. Inhibition of oxidative phosphorylation for enhancing citric acid production by Aspergillus niger.

    Science.gov (United States)

    Wang, Lu; Zhang, Jianhua; Cao, Zhanglei; Wang, Yajun; Gao, Qiang; Zhang, Jian; Wang, Depei

    2015-01-16

    The spore germination rate and growth characteristics were compared between the citric acid high-yield strain Aspergillus niger CGMCC 5751 and A. niger ATCC 1015 in media containing antimycin A or DNP. We inferred that differences in citric acid yield might be due to differences in energy metabolism between these strains. To explore the impact of energy metabolism on citric acid production, the changes in intracellular ATP, NADH and NADH/NAD+ were measured at various fermentation stages. In addition, the effects of antimycin A or DNP on energy metabolism and citric acid production was investigated by CGMCC 5751. By comparing the spore germination rate and the extent of growth on PDA plates containing antimycin A or DNP, CGMCC 5751 was shown to be more sensitive to antimycin A than ATCC 1015. The substrate-level phosphorylation of CGMCC 5751 was greater than that of ATCC 1015 on PDA plates with DNP. DNP at tested concentrations had no apparent effect on the growth of CGMCC 5751. There were no apparent effects on the mycelial morphology, the growth of mycelial pellets or the dry cell mass when 0.2 mg L(-1) antimycin A or 0.1 mg L(-1) DNP was added to medium at the 24-h time point. The concentrations of intracellular ATP, NADH and NADH/NAD+ of CGMCC 5751 were notably lower than those of ATCC 1015 at several fermentation stages. Moreover, at 96 h of fermentation, the citric acid production of CGMCC 5751 reached up to 151.67 g L(-1) and 135.78 g L(-1) by adding 0.2 mg L(-1) antimycin A or 0.1 mg L(-1) DNP, respectively, at the 24-h time point of fermentation. Thus, the citric acid production of CGMCC 5751 was increased by 19.89% and 7.32%, respectively. The concentrations of intracellular ATP, NADH and NADH/NAD+ of the citric acid high-yield strain CGMCC 5751 were notably lower than those of ATCC 1015. The excessive ATP has a strong inhibitory effect on citric acid accumulation by A. niger. Increasing NADH oxidation and appropriately reducing the concentration of

  9. Oxidation of styrene to benzaldehyde/benzoic acid

    Indian Academy of Sciences (India)

    selectivity.11Due to the availability of dual oxidation states of metal ion, it offers the catalytic behaviour towards oxidation of alcohols and olefins resulting in aldehydes or ketones. Such properties are tuned by changing the counter cation of the polyoxoanions, for example, Co3[Si2W12O40] is a good catalyst in oxida-.

  10. Phytoagents for Cancer Management: Regulation of Nucleic Acid Oxidation, ROS, and Related Mechanisms

    Directory of Open Access Journals (Sweden)

    Wai-Leng Lee

    2013-01-01

    Full Text Available Accumulation of oxidized nucleic acids causes genomic instability leading to senescence, apoptosis, and tumorigenesis. Phytoagents are known to reduce the risk of cancer development; whether such effects are through regulating the extent of nucleic acid oxidation remains unclear. Here, we outlined the role of reactive oxygen species in nucleic acid oxidation as a driving force in cancer progression. The consequential relationship between genome instability and cancer progression highlights the importance of modulation of cellular redox level in cancer management. Current epidemiological and experimental evidence demonstrate the effects and modes of action of phytoagents in nucleic acid oxidation and provide rationales for the use of phytoagents as chemopreventive or therapeutic agents. Vitamins and various phytoagents antagonize carcinogen-triggered oxidative stress by scavenging free radicals and/or activating endogenous defence systems such as Nrf2-regulated antioxidant genes or pathways. Moreover, metal ion chelation by phytoagents helps to attenuate oxidative DNA damage caused by transition metal ions. Besides, the prooxidant effects of some phytoagents pose selective cytotoxicity on cancer cells and shed light on a new strategy of cancer therapy. The “double-edged sword” role of phytoagents as redox regulators in nucleic acid oxidation and their possible roles in cancer prevention or therapy are discussed in this review.

  11. A novel glutathione-hydroxycinnamic acid product generated in oxidative wine conditions.

    Science.gov (United States)

    Bouzanquet, Quentin; Barril, Celia; Clark, Andrew C; Dias, Daniel A; Scollary, Geoffrey R

    2012-12-12

    This study characterizes a novel glutathione-substituted dihydroxyphenyl compound formed during the oxidation of white wine and model wine solutions, which may contribute to the synergistic role of glutathione and hydroxycinnamic acids in delaying oxidative coloration. The critical components for the formation of the compound were found to be hydroxycinnamic acids and glutathione, while ascorbic acid enabled the product to accumulate to higher concentrations. The presence of the wine components important in other wine oxidation mechanisms, (+)-catechin, ethanol and/or tartaric acid, was not essential for the formation of this new compound. Via LC-MS/MS, HR-MS and (1)H NMR (1D and 2D NMR) analyses, the major isomer of the compound formed from glutathione and caffeic acid was found to be 4-[(E)-2'-(S)-glutathionyl ethenyl]-catechol (GEC). Equivalent products were also confirmed via LC-MS/MS for other hydroxycinnamic acids (i.e., ferulic and coumaric acids). Only trace amounts of GEC were formed with the quinic ester of caffeic acid (i.e., chlorogenic acid), and no equivalent product was found for cinnamic acid. GEC was detected in a variety of white wines supplemented with glutathione and caffeic acid. A radical mechanism for the formation of the styrene-glutathione derivatives is proposed.

  12. Microcontact Printing onto Oxide-Free Silicon via Highly Reactive Acid Fluoride-Functionalized Monolayers

    NARCIS (Netherlands)

    Scheres, L.M.W.; Maat, ter J.; Giesbers, M.; Zuilhof, H.

    2010-01-01

    This work describes a new route for patterning organic monolayers on oxide-free silicon by microcontact printing (µCP) on a preformed, reactive, acid-fluoride-terminated monolayer. This indirect printing approach is fast and easily preserves the oxide-free and well-defined monolayer-silicon

  13. Kinetics and mechanism of the oxidation of some neutral and acidic ...

    Indian Academy of Sciences (India)

    Unknown

    Addition of bromide ion causes decrease in the oxidation rate but only to a limiting value. The reaction is susceptible to both polar and steric effects of the substituents. A suitable mechanism has been propo- sed. Keywords. Amino acid; tetraalkylammonium tribromide; kinetics; mechanism; oxidation. 1. Introduction.

  14. Kinetics and Mechanism of the Oxidation of Menthol by Potassium Bromate in Acidic Solution

    OpenAIRE

    Ravikant na; Ms. Meena; Shrikant Sharma

    2014-01-01

    No suitable method is available for the estimation of menthol, hence in all kinetic results reported in this chapter, menthol was in excess over potassium bromate and the stoichiometry was also determined under the experimental conditions where menthol (substrate) was in excess over potassium bromate (oxidant). Present study was focused on the analysis of kinetics and mechanism of oxidation of neomenthol by potassium bromate in acidic medium. For oxidizing neomenthol, potassium bromate stock ...

  15. Kinetics and Mechanism of the Oxidation of Neomenthol by Potassium Bromate in Acidic Solution

    OpenAIRE

    Ravikant na

    2014-01-01

    Present study was focused on the analysis of kinetics and mechanism of oxidation of neomenthol by potassium bromate in acidic medium. For oxidizing neomenthol, potassium bromate stock solution (5.0×10─2 mol. dm─3) was prepared by dissolving exactly weighed quantity of potassium bromate in doubly distilled water. The suitable reaction mixtures were prepared and left at 313 K for over 24 hours to ensure complete oxidation of neomenthol15. The unreacted potassium bromate was determined iodometri...

  16. The pro-oxidant gene p66shc increases nicotine exposure-induced lipotoxic oxidative stress in renal proximal tubule cells.

    Science.gov (United States)

    Arany, Istvan; Hall, Samuel; Reed, Dustin K; Dixit, Mehul

    2016-09-01

    Nicotine (NIC) exposure augments free fatty acid (FFA) deposition and oxidative stress, with a concomitant increase in the expression of the pro-oxidant p66shc. In addition, a decrease in the antioxidant manganese superoxide dismutase (MnSOD) has been observed in the kidneys of mice fed a high‑fat diet. The present study aimed to determine whether the pro‑oxidant p66shc mediates NIC‑dependent increases in renal oxidative stress by augmenting the production of reactive oxygen species (ROS) and suppressing the FFA‑induced antioxidant response in cultured NRK52E renal proximal tubule cells. Briefly, NRK52E renal proximal tubule cells were treated with 200 µM NIC, 100 µM oleic acid (OA), or a combination of NIC and OA. The expression levels of p66shc and MnSOD were modulated according to genetic methods. ROS production and cell injury, in the form of lactate dehydrogenase release, were subsequently detected. Promoter activity of p66shc and MnSOD, as well as forkhead box (FOXO)‑dependent transcription, was investigated using reporter luciferase assays. The results demonstrated that NIC exacerbated OA‑mediated intracellular ROS production and cell injury through the transcriptional activation of p66shc. NIC also suppressed OA‑mediated induction of the antioxidant MnSOD promoter activity through p66shc‑dependent inactivation of FOXO activity. Overexpression of p66shc and knockdown of MnSOD had the same effect as treatment with NIC on OA‑mediated lipotoxicity. These data may be used to generate a therapeutic means to ameliorate renal lipotoxicity in obese smokers.

  17. Replacement of two amino acids of 9R-dioxygenase-allene oxide synthase of Aspergillus niger inverts the chirality of the hydroperoxide and the allene oxide.

    Science.gov (United States)

    Sooman, Linda; Wennman, Anneli; Hamberg, Mats; Hoffmann, Inga; Oliw, Ernst H

    2016-02-01

    The genome of Aspergillus niger codes for a fusion protein (EHA25900), which can be aligned with ~50% sequence identity to 9S-dioxygenase (DOX)-allene oxide synthase (AOS) of Fusarium oxysporum, homologues of the Fusarium and Colletotrichum complexes and with over 62% sequence identity to homologues of Aspergilli, including (DOX)-9R-AOS of Aspergillus terreus. The aims were to characterize the enzymatic activities of EHA25900 and to identify crucial amino acids for the stereospecificity. Recombinant EHA25900 oxidized 18:2n-6 sequentially to 9R-hydroperoxy-10(E),12(Z)-octadecadienoic acid (9R-HPODE) and to a 9R(10)-allene oxide. 9S- and 9R-DOX-AOS catalyze abstraction of the pro-R hydrogen at C-11, but the direction of oxygen insertion differs. A comparison between twelve 9-DOX domains of 9S- and 9R-DOX-AOS revealed conserved amino acid differences, which could contribute to the chirality of products. The Gly616Ile replacement of 9R-DOX-AOS (A. niger) increased the biosynthesis of 9S-HPODE and the 9S(10)-allene oxide, whereas the Phe627Leu replacement led to biosynthesis of 9S-HPODE and the 9S(10)-allene oxide as main products. The double mutant (Gly616Ile, Phe627Leu) formed over 90% of the 9S stereoisomer of HPODE. 9S-HPODE was formed by antarafacial hydrogen abstraction and oxygen insertion, i.e., the original H-abstraction was retained but the product chirality was altered. We conclude that 9R-DOX-AOS can be altered to 9S-DOX-AOS by replacement of two amino acids (Gly616Ile, Phe627Leu) in the DOX domain. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Effect of high doses of L-ascorbic acid on the antioxidative/oxidative state in the rats

    DEFF Research Database (Denmark)

    Niemiec, T.; Sawosz, E.; Chwalibog, André

    2005-01-01

    The objective of this study was to determine the effects of mega-doses of vitamin C (0.3, 0.6 and 0.9% of diet) as a dietary supplement for rats on selected indices of the antioxidative/oxidative state in 40 growing Wistar rats (4x10). It was found that L-ascorbic acid and Total Antioxidative State...... (TAS) in plasma did not increase with increasing vitamin C supply. The results indicate that high doses of L-ascorbic acid (0.3 and 0.9 but not 0.6%) increased the concentration of this antioxidant in plasma. Supplementation of vitamin C above 0.3% to the diets had pro-oxidative effects on lipid...

  19. Gibberellic acid, a plant growth regulator, increases mast cell recruitment and alters Substance P levels.

    Science.gov (United States)

    Erin, Nuray; Afacan, Berna; Ersoy, Yasemin; Ercan, Feriha; Balci, Mustafa Kemal

    2008-12-05

    Gibberellic acid (GA3), a plant growth regulator, is used commonly in agriculture. Its potential hazardous effects on human health, however, were relatively unexplored. Several studies demonstrated that in animals chronic GA3 consumption increased tumor formation and oxidative stress. Mast cells and Substance P (SP) play an important role in inflammation. Because chronic inflammation triggers serious conditions, including tumor formation, we examined changes in mast cell recruitment and activation as well as SP levels in skin and urinary bladder. Wistar Albino rats were treated with either a single GA3 dose or multiple GA3 doses for 30 days. Sub-chronic exposure to GA3 markedly increased mast cell recruitment and activation in both tissues. Treatment with 2mg/kg GA3 dose for 30 days decreased SP levels in skin and bladder. SP levels returned to control values in bladder and further increased in skin following 30-day treatment with the 20mg/kg GA3 dose. There was marked urothelial loss and inflammatory cell infiltration in bladder of 30-day GA3 treated groups. In skin, single GA3 doses also decreased SP levels and enhanced mast cell activation and recruitment. Since both SP and mast cell activation elicit inflammatory responses, these results demonstrate that exposure to plant growth regulators may increase inflammatory skin and bladder disease and that use of GA3 should be clearly monitored.

  20. Effect of citric acid dosage and sintered temperature on the composition, morphology and electrochemical properties of lithium vanadium oxide prepared by a sol-gel method

    Science.gov (United States)

    Zhong, C. R.; Su, X. J.; Hou, G. L.; Liu, Z. H.; Yu, F. S.; Bi, S.; Li, H.

    2017-03-01

    A lithium vanadium oxide cathode material was synthesized via sol-gel processing using citric acid as the chelating agent. Different dosage of citric acid and sintered temperature were introduced to investigate their effects on the products composition, morphology and electrochemical properties. The results showed that the V2O3 yield was inhibited and the crystallization of grain was accelerated with the increasing dosage of citric acid. Furthermore, V2O3 was oxidized to LiV3O8 and Li0.3V2O5 with the increase of sintered temperature.

  1. Increase in the permeability of tonoplast of garlic (Allium sativum) by monocarboxylic acids.

    Science.gov (United States)

    Bai, Bing; Li, Lei; Hu, Xiaosong; Wang, Zhengfu; Zhao, Guanghua

    2006-10-18

    Immersion of intact aged garlic (Allium sativum) cloves in a series of 5% weak organic monocarboxylate solutions (pH 2.0) resulted in green color formation. No color was formed upon treatment with other weak organic acids, such as citric and malic acids, and the inorganic hydrochloric acid under the same conditions. To understand the significance of monocarboxylic acids and their differing function from that of other acids, acetic acid was compared with organic acids citric and malic and the inorganic hydrochloric acid. The effects of these acids on the permeability of plasma and intracellular membrane of garlic cells were measured by conductivity, light microscopy, and transmission electron microscopy. Except for hydrochloric acid, treatment of garlic with all three organic acids greatly increased the relative conductivity of their respective pickling solutions, indicating that all tested organic acids increased the permeability of plasma membrane. Moreover, a pickling solution containing acetic acid exhibited 1.5-fold higher relative conductivity (approximately 90%) as compared to those (approximately 60%) of both citric and malic acids, implying that exposure of garlic cloves to acetic acid not only changed the permeability of the plasma membrane but also increased the permeability of intracellular membrane. Exposure of garlic to acetic acid led to the production of precipitate along the tonoplast, but no precipitate was formed by citric and malic acids. This indicates that the structure of the tonoplast was damaged by this treatment. Further support for this conclusion comes from results showing that the concentration of thiosulfinates [which are produced only by catalytic conversion of S-alk(en)yl-l-cysteine sulfoxides in cytosol by alliinase located in the vacuole] in the acetic acid pickling solution is 1.3 mg/mL, but almost no thiosulfinates were detected in the pickling solution of citric and malic acids. Thus, all present results suggest that damage of

  2. Increasing Thai Catfish's Immunity (Pangasius hypophthalmus Fowler Using Ascorbic Acid

    Directory of Open Access Journals (Sweden)

    , Ilmiah

    2007-08-01

    Full Text Available ABSTRACTAn experiment to determine Thai catfish's (Pangasius hypophthalmus Fowler immunity was carried out using different levels of ascorbic acid (0, 1.000, 2.000 and 3.000 mg/kg feed.  Fish of 15-20 g in weight were kept in aquaria for 6 weeks with density of 15 fish/aquaria.  Feed was given at 5-10 % of total biomass with frequency of three times a day.  The blood sampling was taken every week and the challenge test with Aeromonas hydrophila (106cells/mm3 injection intramuscular was done on the 30th day.   The result of this experiment shown that feed with ascorbic acid of 2.000 mg/kg was elevated the cellular responses such as: leucocyte total (34.850 cels/mm3, differential of leucocyte (lymphocyte: 72,2%, monocyte: 8,0%, neutrophyl: 7,8%, phagocytic index (13% and humoral response (titre antibody: 0.829 serum aglutination unit, which at the same time proves high level of survival rate against the artificial injection using A. hydrophila. Key words :  Ascorbic acid, fish immunity, Thai catfish, Pangasius hypophthalmus.   ABSTRAK Suatu penelitian telah dilakukan di laboratorium dengan menggunakan ikan jambal Siam (Pangasius hypophthalmus Fowler untuk melihat tingkat kekebalan ikan dengan menambahkan vitamin C pada pakan (0, 1.000, 2.000 dan 3.000 mg/kg pakan.  Ikan jambal Siam ukuran 15-20 g dipelihara dalam aquarium selama 6 minggu dengan kepadatan 15 ekor/wadah.  Pemberian pakan dilakukan 3 kali sehari sebanyak 5-10% dari bobot biomasa, pengambilan contoh darah dilakukan setiap minggu dan uji tantang dilakukan pada hari ke-30 dengan bakteri Aeromonas hydrophila (106 sel/mm3 secara intramuskular.  Hasil penelitian menunjukkan bahwa penambahan vitamin C sebanyak 2.000 mg/kg pakan menyebabkan meningkatnya respon seluler antara lain: total lekosit (34.850 sel/mm3, jenis lekosit (limfosit: 72,2%, monosit: 8,0%, netrofil: 7,7% dan trombosit: 17,6% indeks fagositik 13% dan respon humoral (titer antibodi: 0,829 unit serum aglutinasi

  3. Efficient Enzymatic Synthesis of Phenolic Ester by Increasing Solubility of Phenolic Acids in Ionic Liquids

    DEFF Research Database (Denmark)

    Yang, Zhiyong; Guo, Zheng; Xu, Xuebing

    Compounds from phenolic acid family are well known natural antioxidants, but the application of phenolic acids as antioxidants in industry is limited due to the relatively low solubility in oil-based media. The properties of phenolic acids can be modified through enzymatic lipophilization...... reactions, and it had been widely used for esterification of various phenolic acids with fatty alcohol or triglycerides. However, the conversion of phenolic acids is low due to low solubility in hydrophobic solvents and hindrance effect of unsaturated side chain towards the enzyme. Our studies show...... and modified phenolic acids will have amphiphilic property, therefore they can be localized at oil-water or water-oil phase where oxidation is considered to occur frequently. It had been reported that immobilized Candida Antarctica lipase B was the most effective biocatalyst for the various esterification...

  4. Bioaugmentation of Syntrophic Acetate-Oxidizing Culture in Biogas Reactors Exposed to Increasing Levels of Ammonia

    Science.gov (United States)

    Westerholm, Maria; Levén, Lotta

    2012-01-01

    The importance of syntrophic acetate oxidation for process stability in methanogenic systems operating at high ammonia concentrations has previously been emphasized. In this study we investigated bioaugmentation of syntrophic acetate-oxidizing (SAO) cultures as a possible method for decreasing the adaptation period of biogas reactors operating at gradually increased ammonia concentrations (1.5 to 11 g NH4+-N/liter). Whole stillage and cattle manure were codigested semicontinuously for about 460 days in four mesophilic anaerobic laboratory-scale reactors, and a fixed volume of SAO culture was added daily to two of the reactors. Reactor performance was evaluated in terms of biogas productivity, methane content, pH, alkalinity, and volatile fatty acid (VFA) content. The decomposition pathway of acetate was analyzed by isotopic tracer experiments, and population dynamics were monitored by quantitative PCR analyses. A shift in dominance from aceticlastic methanogenesis to SAO occurred simultaneously in all reactors, indicating no influence by bioaugmentation on the prevailing pathway. Higher abundances of Clostridium ultunense and Tepidanaerobacter acetatoxydans were associated with bioaugmentation, but no influence on Syntrophaceticus schinkii or the methanogenic population was distinguished. Overloading or accumulation of VFA did not cause notable dynamic effects on the population. Instead, the ammonia concentration had a substantial impact on the abundance level of the microorganisms surveyed. The addition of SAO culture did not affect process performance or stability against ammonia inhibition, and all four reactors deteriorated at high ammonia concentrations. Consequently, these findings further demonstrate the strong influence of ammonia on the methane-producing consortia and on the representative methanization pathway in mesophilic biogas reactors. PMID:22923397

  5. Biologically relevant oxidants and terminology, classification and nomenclature of oxidatively generated damage to nucleobases and 2-deoxyribose in nucleic acids

    DEFF Research Database (Denmark)

    Cadet, Jean; Loft, Steffen; Olinski, Ryszard

    2012-01-01

    A broad scientific community is involved in investigations aimed at delineating the mechanisms of formation and cellular processing of oxidatively generated damage to nucleic acids. Perhaps as a consequence of this breadth of research expertise, there are nomenclature problems for several of the ...

  6. Lipid oxidation in fish oil enriched mayonnaise : Calcium disodium ethylenediaminetetraacetate, but not gallic acid, strongly inhibited oxidative deterioration

    DEFF Research Database (Denmark)

    Jacobsen, Charlotte; Hartvigsen, Karsten; Thomsen, Mikael Holm

    2001-01-01

    was attributed to its ability to chelate free metal ions and iron from egg yolk located at the oil-water interface. Gallic acid reduced the levels of both free radicals and lipid hydroperoxides but promoted slightly the oxidative flavor deterioration in mayonnaise and influenced the profile of volatiles. Gallic...

  7. Mechanism of Oxidation of (p-Substituted Phenylthioacetic Acids with N-Bromophthalimide

    Directory of Open Access Journals (Sweden)

    N. M. I. Alhaji

    2011-01-01

    Full Text Available The kinetics of oxidation of (phenylthioacetic acid (PTAA by N-Bromophthalimide (NBP in acetonitrile-water solvent mixture at 298 K in the presence of perchloric acid has been followed potentiometrically. The reaction is first-order each in NBP and PTAA and inverse fractional-order in H+. Also, it has been found that the reaction rate is not affected by changes in ionic strength of the reaction medium or by the addition of chemicals such as phthalimide, acrylonitrile and potassium bromide. However, an increase in the water content of the solvent mixture causes an increase in the rate of reaction. These observations have been well analyzed in favour of a SN2-type mechanism, involving NBP itself as the reactive species. Effect of substituents on the reaction rate has been analysed by employing various (p-sustituted phenylthioacetic acids. The electron-releasing substituent in the phenyl ring of PTAA accelerates the reaction rate while the electron-withdrawing substituent retards the rate. The excellently linear Hammett plot yields a large negative ρ value, supporting the involvement a bromosulphonium ion intermediate in the rate-determining step.

  8. Kinetics and Mechanistic Chemistry of Oxidation of Butacaine Sulfate by Chloramine-B in Acid Medium

    Energy Technology Data Exchange (ETDEWEB)

    Shubha, Jayachamarajapura Pranesh; Kotabagi, Vinutha [Bosco Institute of Technology, Bangalore (India); Puttaswamy [Bangalore Univ., Bangalore (India)

    2012-11-15

    Butacaine sulfate is an ester of p-aminobenzoic acid which has been widely used as a local anaesthetic and it is a long standing agent particularly for spinal anaesthesia. For this reason, a kinetic study of oxidation of butacaine sulfate by sodium N-chlorobenzenesulfonamide (chloramine-B or CAB) has been carried out in HClO{sub 4} medium at 303 K in order to explore this redox system mechanistic chemistry. The rate shows a first-order dependence on both [CAB]{sub o}, and [substrate]{sub o}, and a fractional-order dependence on acid concentration. Decrease of dielectric constant of the medium, by adding methanol, increases the rate of the reaction. Variation of ionic strength and addition of benzenesulfonamide or NaCl have no significant effect on the rate. The reaction was studied at different temperatures and the activation parameters have been evaluated. The stoichiometry of the reaction has been found to be 1:2 and the oxidation products have been identified by spectral analysis. The observed results have been explained by plausible mechanism and the related rate law has been deduced.

  9. Photoelectrocatalytic degradation of oxalic acid by spray deposited nanocrystalline zinc oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Shinde, S.S. [Electrochemical Materials Laboratory, Department of Physics, Shivaji University, Kolhapur 416004 (India); Shinde, P.S. [Department of Nano-Engineering, Kyungnam University, Masan 631-701 (Korea, Republic of); Sapkal, R.T. [Electrochemical Materials Laboratory, Department of Physics, Shivaji University, Kolhapur 416004 (India); Oh, Y.W. [Department of Nano-Engineering, Kyungnam University, Masan 631-701 (Korea, Republic of); Haranath, D. [National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110 012 (India); Bhosale, C.H. [Electrochemical Materials Laboratory, Department of Physics, Shivaji University, Kolhapur 416004 (India); Rajpure, K.Y., E-mail: rajpure@yahoo.com [Electrochemical Materials Laboratory, Department of Physics, Shivaji University, Kolhapur 416004 (India)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer Influence of substrate temperature onto the physico-chemical properties. Black-Right-Pointing-Pointer Photochemical, structural, luminescent, optoelectrical and thermal properties. Black-Right-Pointing-Pointer The kinetics of oxalic acid degradation with reaction mechanism. Black-Right-Pointing-Pointer Extent of mineralization by COD and TOC. - Abstract: The high quality nano-crystalline zinc oxide thin films are deposited onto corning glasses by spray pyrolysis technique. The influence of reaction temperature onto their photoelectrochemical, structural, morphological, optoelectronic, luminescence and thermal properties has been investigated. The structural characteristics studied by X-ray diffractometry has complemented by resistivity measurements and UV-Vis spectroscopy. The photoelectrochemical activity shows enhancement in short circuit current (I{sub sc} = 0.357 mA) and open circuit voltage (V{sub oc} = 0.48 V). Direct band gap calculated by considering R and T values of ZnO thin films increases from 3.14-3.21 eV exhibiting a slight blue shift in band edge. Three characteristic luminescence peaks having near band-edge, blue and green emission are observed in the photoluminescence spectra. The specific heat and thermal conductivity study shows the phonon conduction behavior is dominant in films. Photocatalytic degradation of oxalic acid followed with reaction mechanism by using zinc oxide photoelectrode under solar illumination has been investigated.

  10. Graphene nanosheets-polypyrrole hybrid material as a highly active catalyst support for formic acid electro-oxidation

    Science.gov (United States)

    Yang, Sudong; Shen, Chengmin; Liang, Yanyu; Tong, Hao; He, Wei; Shi, Xuezhao; Zhang, Xiaogang; Gao, Hong-Jun

    2011-08-01

    A novel electrode material based on graphene oxide (GO)-polypyrrole (PPy) composites was synthesized by in situ chemical oxidation polymerization. Palladium nanoparticles (NPs) with a diameter of 4.0 nm were loaded on the reduced graphene oxide(RGO)-PPy composites by a microwave-assisted polyol process. Microstructure analysis showed that a layer of coated PPy film with monodisperse Pd NPs is present on the RGO surface. The Pd/RGO-PPy catalysts exhibit excellent catalytic activity and stability for formic acid electro-oxidation when the weight feed ratio of GO to pyrrole monomer is 2 : 1. The superior performance of Pd/RGO-PPy catalysts may arise from utilization of heterogeneous nucleation sites for NPs and the greatly increased electronic conductivity of the supports.

  11. Can allopurinol improve retinopathy in diabetic rats? Oxidative stress or uric acid; which one is the culprit?

    Science.gov (United States)

    Goharinia, Mohsen; Zareei, Athar; Rahimi, Mansour; Mirkhani, Hossein

    2017-10-01

    Allopurinol, an inhibitor of xanthine oxidase, reduces both plasma uric acid and oxidative stress and shows useful effects on some complications of diabetes. However, it is not defined which of the above mentioned properties are involved. Moreover, to the best of our knowledge no study has been done on the effects of allopurinol on diabetic retinopathy. In the present study, the effect of allopurinol on experimental diabetic retinopathy and its possible mechanism has been investigated. Thirty two rats were divided into four groups of eight rats each; (1) normal, (2) diabetic control, (3) diabetic + allopurinol (50 mg/kg.day), (4) diabetic + benzbromarone (10 mg/kg.day). Drugs were administered daily and orally from the day after diabetes induction for eight weeks. Thereafter retinal function and structure were evaluated by electroretinography and microscopic studies. Uric acid and oxidative stress biomarkers were measured biochemically. Diabetes significantly increased plasma uric acid and oxidative stress markers and reduced body weight and amplitude of electroretinogram (ERG) b-wave and oscillatory potentials. Treatment of diabetic rats with allopurinol caused a significant increase in the amplitude of ERG b-wave (87%) and decrease in blood sugar (20%), uric acid (49%), and 8-iso-prostaglandin F2a (56%), but had no effect on the number of retinal ganglionic cells and oscillatory potentials. Benzbromarone showed no significant effects on the considered parameters except the reduction of uric acid. Allopurinol improved the b-wave amplitude of diabetic rats. It seems that this beneficial effect is due to the reduction of oxidative stress rather than its effect on plasma uric acid.

  12. [Effects of exogenous nitric oxide on physiological characteristics of longan (Dimocarpus longana) seedlings under acid rain stress].

    Science.gov (United States)

    Liu, Jian-fu; Wang, Ming-yuan; Yang, Chen; Zhu, Ai-jun

    2013-08-01

    This paper studied the effects of exogenous nitric oxide donor sodium nitroprusside (SNP) on the chlorophyll content, antioxidant enzyme activities, and osmotic regulation substances of longan (Dimocarpus longana 'Fuyan') seedlings under acid rain (pH 3.0) stress. Under the acid rain stress, the seedling leaf superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities and chlorophyll, soluble protein and soluble sugar contents decreased obviously, while the leaf malondialdedyde content had a remarkable increase, suggesting the toxic effect of the acid rain on the seedlings. Exogenous nitric oxide had dual nature on the physiological characteristics of longan seedlings under acid rain stress. Applying 0.1-0.5 mmol x L(-1) of SNP improved the SOD, POD and CAT activities and the chlorophyll, soluble protein and soluble sugar contents significantly, and decreased the malondialdedyde content. Low concentrations SNP reduced the oxidative damage caused by the acid rain stress, and 0.5 mmol x L(-1) of SNP had the best effect. Under the application of 0.5 mmol x L(-1) of SNP, the total chlorophyll, soluble protein, and soluble sugar contents and the SOD, POD and CAT activities increased by 76.0%, 107.0%, 216.1%, 150. 0%, 350.9% and 97.1%, respectively, and the malondialdedyde content decreased by 46.4%. It was suggested that low concentration (0.1-0.5 mmol x L(-1)) SNP could alleviate the toxic effect of acid rain stress on longan seedlings via activating the leaf antioxidant enzyme activities and reducing oxidative stress, while high concentration SNP (1.0 mmol x L(-1)) lowered the mitigation effect.

  13. Measurement of the rates of oxindole-3-acetic acid turnover, and indole-3-acetic acid oxidation in Zea mays seedlings

    Science.gov (United States)

    Nonhebel, H. M.; Bandurski, R. S. (Principal Investigator)

    1986-01-01

    Oxindole-3-acetic acid is the principal catabolite of indole-3-acetic acid in Zea mays seedlings. In this paper measurements of the turnover of oxindole-3-acetic acid are presented and used to calculate the rate of indole-3-acetic acid oxidation. [3H]Oxindole-3-acetic acid was applied to the endosperm of Zea mays seedlings and allowed to equilibrate for 24 h before the start of the experiment. The subsequent decrease in its specific activity was used to calculate the turnover rate. The average half-life of oxindole-3-acetic acid in the shoots was found to be 30 h while that in the kernels had an average half-life of 35h. Using previously published values of the pool sizes of oxindole-3-acetic acid in shoots and kernels from seedlings of the same age and variety, and grown under the same conditions, the rate of indole-3-acetic acid oxidation was calculated to be 1.1 pmol plant-1 h-1 in the shoots and 7.1 pmol plant-1 h-1 in the kernels.

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

    Science.gov (United States)

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

    2010-07-15

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

  15. Arginase-Negative Mutants of Arabidopsis Exhibit Increased Nitric Oxide Signaling in Root Development

    National Research Council Canada - National Science Library

    Teresita Flores; Christopher D. Todd; Alejandro Tovar-Mendez; Preetinder K. Dhanoa; Natalia Correa-Aragunde; Mary Elizabeth Hoyos; Disa M. Brownfield; Robert T. Mullen; Lorenzo Lamattina; Joe C. Polacco

    2008-01-01

    ...) seedlings and increased nitric oxide (NO) accumulation and efflux, detected by the fluorogenic traps 3-amino,4-aminomethyl-2',7'-difluorofluorescein diacetate and diamino-rhodamine-4M, respectively...

  16. Increased tolerance to salt stress in OPDA-deficient rice ALLENE OXIDE CYCLASE mutants is linked to an increased ROS-scavenging activity

    Science.gov (United States)

    Hazman, Mohamed; Hause, Bettina; Eiche, Elisabeth; Nick, Peter; Riemann, Michael

    2015-01-01

    Salinity stress represents a global constraint for rice, the most important staple food worldwide. Therefore the role of the central stress signal jasmonate for the salt response was analysed in rice comparing the responses to salt stress for two jasmonic acid (JA) biosynthesis rice mutants (cpm2 and hebiba) impaired in the function of ALLENE OXIDE CYCLASE (AOC) and their wild type. The aoc mutants were less sensitive to salt stress. Interestingly, both mutants accumulated smaller amounts of Na+ ions in their leaves, and showed better scavenging of reactive oxygen species (ROS) under salt stress. Leaves of the wild type and JA mutants accumulated similar levels of abscisic acid (ABA) under stress conditions, and the levels of JA and its amino acid conjugate, JA–isoleucine (JA-Ile), showed only subtle alterations in the wild type. In contrast, the wild type responded to salt stress by strong induction of the JA precursor 12-oxophytodienoic acid (OPDA), which was not observed in the mutants. Transcript levels of representative salinity-induced genes were induced less in the JA mutants. The absence of 12-OPDA in the mutants correlated not only with a generally increased ROS-scavenging activity, but also with the higher activity of specific enzymes in the antioxidative pathway, such as glutathione S-transferase, and fewer symptoms of damage as, for example, indicated by lower levels of malondialdehyde. The data are interpreted in a model where the absence of OPDA enhanced the antioxidative power in mutant leaves. PMID:25873666

  17. Verapamil reverses PTH- or CRF-induced abnormal fatty acid oxidation in muscle

    Energy Technology Data Exchange (ETDEWEB)

    Perna, A.F.; Smogorzewski, M.; Massry, S.G.

    1988-12-01

    Chronic renal failure (CRF) is associated with impaired long chain fatty acids (LCFA) oxidation by skeletal muscle mitochondria. This is due to reduced activity of carnitine palmitoyl transferase (CPT). These derangements were attributed to the secondary hyperparathyroidism of CRF, since prior parathyroidectomy in CRF rats reversed these abnormalities and PTH administration to normal rats reproduced them. It was proposed that these effects of PTH are mediated by its ionophoric property leading to increased entry of calcium into skeletal muscle. A calcium channel blocker may, therefore, correct these derangements. The present study examined the effects of verapamil on LCFA oxidation, CPT activity by skeletal muscle mitochondria, and /sup 45/Ca uptake by skeletal muscle obtained from CRF rats and normal animals treated with PTH with and without verapamil. Both four days of PTH administration and 21 days of CRF produced significant (P less than 0.01) reduction in LCFA oxidation and CPT activity of skeletal muscle mitochondria, and significant (P less than 0.01) increment in /sup 45/Ca uptake by skeletal muscle. Simultaneous treatment with verapamil corrected all these derangements. Administration of verapamil alone to normal rats did not cause a significant change in any of these parameters. The data are consistent with the proposition that the alterations in LCFA in CRF or after PTH treatment are related to the ionophoric action of the hormone and could be reversed by a calcium channel blocker.

  18. UREMIC TOXIN GUANIDINE ACETIC ACID INHIBITS THE OXIDATIVE METABOLISM OF NEUTROPHILS IN DOGS

    Directory of Open Access Journals (Sweden)

    Priscila Preve Pereira

    2015-10-01

    Full Text Available Abstract Among the uremic toxins proven to affect the neutrophil function in humans with chronic kidney disease (CKD, guanidine compounds stand out. To achieve a clearer understanding of the mechanisms that affect the immunity of uremic patients, the hypothesis that guanidine acetic acid (GAA contributes to the inhibition of oxidative metabolism and an increase in neutrophil apoptosis in healthy dogs was investigated in vitro. To this end, neutrophils isolated from ten healthy dogs were incubated in pure RPMI 1640 (control and enriched with 5 mg/L of GAA. Capillary flow cytometry was used to quantify superoxide production in neutrophils with the probe (hydroethidine, in the presence and absence of phorbol-12-myristate-13-acetate (PMA, in order to assess oxidative metabolism. Apoptotic indices were quantified using the Annexin V-PE system, with and without the inductive effect of camptothecin. Neutrophils isolated and incubated in a GAA-enriched medium produced smaller amounts of superoxide (p<0.001 when activated with PMA, however, this inhibition of oxidative metabolism occurred without significantly altering their viability or rate of apoptosis. Thus, the results show guanidine compounds contribute to immunosuppression in dogs with CKD.

  19. Oxidative stability during storage of structured lipids produced from fish oil and caprylic acid

    DEFF Research Database (Denmark)

    Nielsen, Nina Skall; Xu, Xuebing; Timm Heinrich, Maike

    2004-01-01

    lipid (SFO), produced by enzymatic interesterification from the same oil and caprylic acid, was compared with the stability of FO. Oils were stored at 2degreesC for 11 wk followed by storage at 20degreesC for 6 wk. In addition, the antioxidative effect of adding the metal chelators EDTA or citric acid...... period, and off-flavors were more pronounced in SFO. The lower oxidative stability of SFO was probably related to the initially lower quality (regarding oxidation products), which is apparently a result of the long production procedure required. Addition of metal chelators did not reduce the oxidation...

  20. Increase of oxidation and inflammation in nervous and immune systems with aging and anxiety.

    Science.gov (United States)

    Vida, Carmen; González, Eva M; De la Fuente, Mónica

    2014-01-01

    According to the oxidation-inflammation theory of aging, chronic oxidative stress and inflammatory stress situations (with higher levels of oxidant and inflammatory compounds and lower antioxidant and anti-inflammatory defenses) are the basis of the agerelated impairment of organism functions, including those of the nervous and immune systems, as well as of the neuroimmune communication, which explains the altered homeostasis and the resulting increase of morbidity and mortality. Overproduction of oxidant compounds can induce an inflammatory response, since oxidants are inflammation effectors. Thus, oxidation and inflammation are interlinked processes and have many feedback loops. However, the nature of their potential interactions, mainly in the brain and immune cells, and their key involvement in aging remain unclear. Moreover, in the context of the neuroimmune communication, it has been described that an oxidative-inflammatory situation occurs in subjects with anxiety, and this situation contributes to an immunosenescence, alteration of survival responses and shorter life span. As an example of this, a model of premature aging in mice, in which animals show a poor response to stress and high levels of anxiety, an oxidative stress in their immune cells and tissues, as well as a premature immunosenescence and a shorter life expectancy, will be commented in the present review. This model supports the hypothesis that anxiety can be a situation of chronic oxidative stress and inflammation, especially in brain and immune cells, and this accelerates the rate of aging.

  1. Palladium(II)/Brønsted Acid-Catalyzed Enantioselective Oxidative Carbocyclization–Borylation of Enallenes**

    Science.gov (United States)

    Jiang, Tuo; Bartholomeyzik, Teresa; Mazuela, Javier; Willersinn, Jochen; Bäckvall, Jan-E

    2015-01-01

    An enantioselective oxidative carbocyclization–borylation of enallenes that is catalyzed by palladium(II) and a Brønsted acid was developed. Biphenol-type chiral phosphoric acids were superior co-catalysts for inducing the enantioselective cyclization. A number of chiral borylated carbocycles were synthesized in high enantiomeric excess. PMID:25808996

  2. Biological iron(II) oxidation as pre-treatment to limestone neutralisation of acid water

    CSIR Research Space (South Africa)

    Maree, JP

    1998-01-01

    Full Text Available Iron (II) should be oxidised to iron (III) before the neutralisation of acid water with limestone, otherwise the oxidation will occur downstream of the neutralisation plant with the formation of acid (reactions 1 and 2). This study aimed...

  3. Serum uric acid levels and leukocyte nitric oxide production in multiple sclerosis patients outside relapses

    NARCIS (Netherlands)

    Mostert, JP; Ramsaransing, GSM; Heerserna, DJ; Heerings, M; Wilczak, N; De Keyser, J

    2005-01-01

    Background: A number of studies found that patients with multiple sclerosis (MS) have low serum levels of uric acid. It is unclear whether this represents a primary deficit or secondary effect. Uric acid is a scavenger of peroxynitrite, which is the product of nitric oxide (NO) and superoxide.

  4. Biochemical Competition Makes Fatty-Acid beta-Oxidation Vulnerable to Substrate Overload

    NARCIS (Netherlands)

    van Eunen, Karen; Simons, Sereh M. J.; Gerding, Albert; Bleeker, Aycha; den Besten, Gijs; Touw, Catharina M. L.; Houten, Sander M.; Groen, Bert K.; Krab, Klaas; Reijngoud, Dirk-Jan; Bakker, Barbara M.

    Fatty-acid metabolism plays a key role in acquired and inborn metabolic diseases. To obtain insight into the network dynamics of fatty-acid beta-oxidation, we constructed a detailed computational model of the pathway and subjected it to a fat overload condition. The model contains reversible and

  5. An innovative zinc oxide-coated zeolite adsorbent for removal of humic acid

    Science.gov (United States)

    Zinc oxide (ZnO)-coated zeolite adsorbents were developed by both nitric acid modification and Zn(NO3)2•6H2O functionalization of zeolite. The developed adsorbents were used for the removal of humic acid (HA) from aqueous solutions. The adsorption capacity of the adsorbents at 21...

  6. Natural and pyrogenic humic acids at goethite and natural oxide surfaces interacting with phosphate

    NARCIS (Netherlands)

    Hiemstra, T.; Mia, S.; Duhaut, P.B.; Molleman, B.

    2013-01-01

    Fulvic and humic acids have a large variability in binding to metal (hydr) oxide surfaces and interact differently with oxyanions, as examined here experimentally. Pyrogenic humic acid has been included in our study since it will be released to the environment in the case of large-scale application

  7. Fatty acids, lipid and protein oxidation, metmyoglobin reducing ...

    African Journals Online (AJOL)

    ... of chronic diseases in humans substantiates efforts to modify its lipid profile. ... the lipid profile of ruminant meat could affect its quality attributes and shelf life. ... colour, metmyoglobin reducing activity (MRA) and lipid and protein oxidation in ...

  8. Phytochemicals in regulating fatty acid β-oxidation: Potential underlying mechanisms and their involvement in obesity and weight loss.

    Science.gov (United States)

    Rupasinghe, H P Vasantha; Sekhon-Loodu, Satvir; Mantso, Theodora; Panayiotidis, Mihalis I

    2016-09-01

    Excessive accumulation of fat as the result of more energy intake and less energy expenditure is known as obesity. Lipids are essential components in the human body and are vital for maintaining homeostasis and physiological as well as cellular metabolism. Fatty acid synthesis and catabolism (by fatty acid oxidation) are normal part of basic fuel metabolism in animals. Fatty acids are degraded in the mitochondria by a biochemical process called β-oxidation in which two-carbon fragments are produced in each cycle. The increase in fatty acid β-oxidation is negatively correlated with body mass index. Although healthy life style, avoiding Western diet, dieting and strenuous exercise are the commonly used methods to lose weight, they are not considered a permanent solution in addition to risk attenuation of basal metabolic rate (BMR). Pharmacotherapy offers benefits of weight loss by altering the satiety and lowering absorption of fat from the food; however, its side effects may outweigh the benefits of weight loss. Alternatively, dietary phytochemicals and natural health products offer great potential as an efficient weight loss strategy by modulating lipid metabolism and/or increasing BMR and thermogenesis. Specifically, polyphenols such as citrus flavonoids, green tea epigallocatechin gallate, resveratrol, capsaicin and curcumin, have been reported to increase lipolysis and induce fatty acid β-oxidation through modulation of hormone sensitive lipase, acetyl-coA carboxylase, carnitine acyl transferase and peroxisome proliferator-activated receptor gamma coactivator-1. In this review article, we discuss selected phytochemicals in relation to their integrated functionalities and specific mechanisms for weight loss. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Ocean acidification increases fatty acids levels of larval fish.

    Science.gov (United States)

    Díaz-Gil, Carlos; Catalán, Ignacio A; Palmer, Miquel; Faulk, Cynthia K; Fuiman, Lee A

    2015-07-01

    Rising levels of anthropogenic carbon dioxide in the atmosphere are acidifying the oceans and producing diverse and important effects on marine ecosystems, including the production of fatty acids (FAs) by primary producers and their transfer through food webs. FAs, particularly essential FAs, are necessary for normal structure and function in animals and influence composition and trophic structure of marine food webs. To test the effect of ocean acidification (OA) on the FA composition of fish, we conducted a replicated experiment in which larvae of the marine fish red drum (Sciaenops ocellatus) were reared under a climate change scenario of elevated CO2 levels (2100 µatm) and under current control levels (400 µatm). We found significantly higher whole-body levels of FAs, including nine of the 11 essential FAs, and altered relative proportions of FAs in the larvae reared under higher levels of CO2. Consequences of this effect of OA could include alterations in performance and survival of fish larvae and transfer of FAs through food webs. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  10. Human milk arachidonic acid and docosahexaenoic acid contents increase following supplementation during pregnancy and lactation

    NARCIS (Netherlands)

    van Goor, Saskia A.; Dijick-Brouwer, D. A. Janneke; Hadders-Algra, Mijna; Doornbos, Bennard; Erwich, Jan Jaap H. M.; Schaafsma, Anne; Muskiet, Frits A. J.; Djick-Brouwer, D.A.J.

    Introduction: Docosahexaenoic acid (DHA) and arachidonic acid (AA) are important for neurodevelopment. Maternal diet influences milk DHA, whereas milk AA seems rather constant. We investigated milk AA, DHA and DHA/AA after supplementation of AA plus DHA, or DHA alone during pregnancy and lactation.

  11. The utilization of oil palm fronds in producing oxalic acid through oxidation

    Science.gov (United States)

    Maulina, Seri; Rahmadi, Ihwan

    2017-08-01

    As one of the solid waste generated by palm oil plantations, Oil Palm Fronds have the potential to be further processed into useful products since the presence of cellulose, hemicellulose and lignin. Hence, the objective of this study was to utilize oil palm fronds in producing oxalic acid through oxidation process using. To achieve the objective, this study assessed conversion of cellulose, yield and quality of oxalic acid produced. Two stages are carried out, namely oxidation and crystallization. Assays on raw materials revealed the cellulose content of 29.2 percent. The largest yield of oxalic acid was 43.31 percent, the highest conversion of cellulose was 58.86 percent. FTIR and melting point analysis were employed in this study. These analyses indicated that the functional groups have reached the standard of oxalic acid with a melting point of 102.1 °C, which showed that the oxalic acid obtained was oxalic acid dehydrate.

  12. AMPK activation through mitochondrial regulation results in increased substrate oxidation and improved metabolic parameters in models of diabetes.

    Directory of Open Access Journals (Sweden)

    Yonchu Jenkins

    Full Text Available Modulation of mitochondrial function through inhibiting respiratory complex I activates a key sensor of cellular energy status, the 5'-AMP-activated protein kinase (AMPK. Activation of AMPK results in the mobilization of nutrient uptake and catabolism for mitochondrial ATP generation to restore energy homeostasis. How these nutrient pathways are affected in the presence of a potent modulator of mitochondrial function and the role of AMPK activation in these effects remain unclear. We have identified a molecule, named R419, that activates AMPK in vitro via complex I inhibition at much lower concentrations than metformin (IC50 100 nM vs 27 mM, respectively. R419 potently increased myocyte glucose uptake that was dependent on AMPK activation, while its ability to suppress hepatic glucose production in vitro was not. In addition, R419 treatment of mouse primary hepatocytes increased fatty acid oxidation and inhibited lipogenesis in an AMPK-dependent fashion. We have performed an extensive metabolic characterization of its effects in the db/db mouse diabetes model. In vivo metabolite profiling of R419-treated db/db mice showed a clear upregulation of fatty acid oxidation and catabolism of branched chain amino acids. Additionally, analyses performed using both (13C-palmitate and (13C-glucose tracers revealed that R419 induces complete oxidation of both glucose and palmitate to CO2 in skeletal muscle, liver, and adipose tissue, confirming that the compound increases mitochondrial function in vivo. Taken together, our results show that R419 is a potent inhibitor of complex I and modulates mitochondrial function in vitro and in diabetic animals in vivo. R419 may serve as a valuable molecular tool for investigating the impact of modulating mitochondrial function on nutrient metabolism in multiple tissues and on glucose and lipid homeostasis in diabetic animal models.

  13. Reaction of Oxidized Polysialic Acid and a Diaminooxy Linker: Characterization and Process Optimization Using Nuclear Magnetic Resonance Spectroscopy.

    Science.gov (United States)

    Ray, G Joseph; Siekmann, Jürgen; Scheinecker, Richard; Zhang, Zhenqing; Gerasimov, Mikhail V; Szabo, Christina M; Kosma, Paul

    2016-09-21

    Native polysialic acid (natPSA) is a high-molecular-weight glycan composed of repeat units of α-(2 → 8) linked N-acetylneuraminic acid (Neu5Ac). Mild periodate oxidation of PSA selectively targets the end sialic acid ring containing three adjacent alcohols generating a putative aldehyde, which can be used, after attachment of a linker molecule, for terminal attachment of PSA to protein. Previously, we showed that the oxidized PSA (oxoPSA) contained a hemiacetal at the oxidation site and can react with a linker containing an aminooxy group in a conjugation reaction to form a stable oxime linkage. Thus, reagents containing an aminooxy group may be prepared for conjugation of PSA to the carbohydrate moiety of therapeutic proteins, thereby increasing their half-life. These aminooxy-PSA reagents can selectively react with aldehyde groups generated by mild NaIO4 oxidation of glycans on the surface of the target protein. To comprehend the conjugation, unoxidized tetrasialic acid and Neu5Ac were reacted in model reactions with a diaminooxy linker to define the nuclear magnetic resonance (NMR) chemical shifts. Based on these data, we were able to show that, in the case of PSA, the reaction with the linker occurs not only at the expected oxidized end to form an aldoxime but also at the end distal to the oxidation to form a ketoxime. We determined that, in aged solutions, both oxoPSA and PSA aldoxime were hydrolyzed. PSA aldoxime was also shown to disproportionate to form a dimer (PSA-linker-PSA), which then could react further with the released linker at one of its PSA termini. Furthermore, NMR was used to monitor the effects of deliberate process changes so that conditions could be optimized for attachment of linker at the desired end of the PSA chain, which led to a well-defined product.

  14. Ferrous iron oxidation by molecular oxygen under acidic conditions: The effect of citrate, EDTA and fulvic acid

    Science.gov (United States)

    Jones, Adele M.; Griffin, Philippa J.; Waite, T. David

    2015-07-01

    In this study, the rates of Fe(II) oxidation by molecular oxygen in the presence of citrate, ethylenediaminetetraacetic acid (EDTA) and Suwannee River fulvic acid (SRFA) were determined over the pH range 4.0-5.5 and, for all of the ligands investigated, found to be substantially faster than oxidation rates in the absence of any ligand. EDTA was found to be particularly effective in enhancing the rate of Fe(II) oxidation when sufficient EDTA was available to complex all Fe(II) present in solution, with a kinetic model of the process found to adequately describe all results obtained. When Fe(II) was only partially complexed by EDTA, reactions with reactive oxygen species (ROS) and heterogeneous Fe(II) oxidation were found to contribute significantly to the removal rate of iron from solution at different stages of oxidation. This was possible due to the rapid rate at which EDTA enhanced Fe(II) oxidation and formed ROS and Fe(III). The rapid rate of Fe(III) generation facilitated the formation of free ferric ion activities in excess of those required for ferric oxyhydroxide precipitation following Fe(III)-EDTA dissociation. In comparison, the rate of Fe(II) oxidation was slower in the presence of citrate, and therefore the concentrations of free Fe(III) able to form in the initial stages of Fe(II) oxidation were much lower than those formed in the presence of EDTA, despite the resultant Fe(III)-citrate complex being less stable than that of Fe(III)-EDTA. The slower rate of citrate enhanced oxidation also resulted in slower rates of ROS generation, and, as such, oxidation of the remaining inorganic Fe(II) species by ROS was negligible. Overall, this study demonstrates that organic ligands may substantially enhance the rate of Fe(II) oxidation. Even under circumstances where the ligand is not present at sufficient concentrations to complex all of the Fe(II) in solution, ensuing oxidative processes may sustain an enhanced rate of Fe(II) oxidation relative to that of

  15. Influence of pH-control in phosphoric acid treatment of zinc oxide

    Energy Technology Data Exchange (ETDEWEB)

    Onoda, H., E-mail: onoda@kpu.ac.jp [Department of Informatics and Environmental Sciences, Kyoto Prefectural University (Japan); Chemel, M. [Ecole de Biologie Industrielle, CERGY Cedex (France)

    2017-04-15

    Zinc oxide is often used as a white pigment for cosmetics; however, it shows photocatalytic activity that causes decomposition of sebum on the skin when exposed to the ultraviolet radiation in sunlight. In this work, zinc oxide was reacted with phosphoric acid at various pH values to synthesize a novel white pigment for cosmetics. The chemical composition, powder properties, photocatalytic activities, colors, and smoothness of these pigments were studied. The obtained materials exhibited X-ray diffraction peaks relating to zinc oxide and phosphate after phosphoric acid treatment. The ratio of zinc phosphate to zinc oxide was estimated from inductively coupled plasma - atomic emission spectroscopy results. Samples treated at pH 4-7 yielded small particles with sub-micrometer sizes. The photocatalytic activity of zinc oxide became lower after phosphoric acid treatment. Samples treated at pH 4-7 showed the same reflectance as zinc oxide in both the ultraviolet and visible ranges. Adjustment of the pH was found to be important in the phosphoric acid treatment of zinc oxide. (author)

  16. A Comparative Study of Basic, Amphoteric, and Acidic Catalysts in the Oxidative Coupling of Methanol and Ethanol for Acrolein Production.

    Science.gov (United States)

    Lilić, Aleksandra; Wei, Tiantian; Bennici, Simona; Devaux, Jean-François; Dubois, Jean-Luc; Auroux, Aline

    2017-09-11

    The impact of acid/base properties (determined by adsorption microcalorimetry) of various catalysts on the cross-aldolization of acetaldehyde and formaldehyde leading to acrolein was methodically studied in oxidizing conditions starting from a mixture of methanol and ethanol. The aldol condensation and further dehydration to acrolein were carried out on catalysts presenting various acid/base properties (MgO, Mg-Al oxides, Mg/SiO 2 , NbP, and heteropolyanions on silica, HPA/SiO 2 ). Thermodynamic calculations revealed that cross-aldolization is always favored compared with self-aldolization of acetaldehyde, which leads to crotonaldehyde formation. The presence of strong basic sites is shown to be necessary, but a too high amount drastically increases CO x production. On strong acid sites, production of acrolein and carbon oxides (CO x ) does not increase with temperature. The optimal catalyst for this process should be amphoteric with a balanced acid/base cooperation of medium strength sites and a small amount (150 kJ mol -1 ). © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Kinetic and Mechanism of Oxidation of Oxalic Acid by Cerium (IV)

    OpenAIRE

    Dr. Ammar J. Mohammed

    2005-01-01

    Kinetic and mechanism studies of the oxidation of oxalic acid by Cerium sulphate have been carried out in acid medium sulphuric acid. The uv- vis. Spectrophotometric technique was used to follow up the reaction and the selected wavelength to be followed was 320 nm. The kinetic study showed that the order of reaction is first order in Ce(IV) and fractional in oxalic acid. The effect of using different concentration of sulphuric acid on the rate of the reaction has been studied a and it was fou...

  18. The oxidation of tetrabromobisphenol A by potassium monopersulfate with an iron(III)-phthalocyanine-tetrasulfonic acid catalyst in the presence of humic acid.

    Science.gov (United States)

    Maeno, Shohei; Mizutani, Yusuke; Zhu, Qianqian; Miyamoto, Takafumi; Fukushima, Masami; Kuramitz, Hideki

    2014-01-01

    Tetrabromobisphenol A (TBBPA), a type of brominated flame retardant that shows endocrine disruption effects, has been identified in leachates from landfills. Iron(III)-porphyrins that mimic the active site of peroxidases have been shown to be effective in oxidizing halogenated phenols, such as TBBPA. In the present study, TBBPA was subjected to oxidation with potassium monopersulfate (KHSO5) using an iron(III)-phthalocyanine-tetrasulfonic acid (FePcTS), structural analogue of iron(III)-porphyrin, in the presence of humic acid (HA), a major component in landfill leachates. When TBBPA was oxidized using the above system, the levels of degradation and debromination increased with increasing pH in the presence of HA. Because of landfill leachates are weakly alkaline (around pH 8), oxidation products derived from TBBPA were investigated at pH 8. Approximately 48% of the bromine in the degraded TBBPA was incorporated into HA, and hydroxy-tribromobisphenol A was determined to be the major brominated intermediate in the HA fraction. In the iron(III)-porphyrin catalytic systems, the brominated intermediate incorporated into HA is mainly TBBPA, and no hydroxy-substituted bromophenols are found. Thus, the catalytic power of FePcTS is higher than that of iron(III)-porphyrin catalysts.

  19. the roles of gastric acid and nitric oxide

    African Journals Online (AJOL)

    Dr Olaleye

    Fujishita, T., Furutani, K and Okabe, S. (2003):. Pharmacological control of gastric acid secretion for the treatment of acid-related peptic disease: past, present and future. Pharmacol. Ther. 98:109-127. Amure, B.O., and Ginsburg, M. (1964). Inhibitors of histamine catabolism and the action of gastrin in the rat. Br. J. Pharmacol.

  20. Potent protection of gallic acid against DNA