TiO2 suspension exposed to H2O2 in ambient light or darkness: Degradation of methylene blue and EPR evidence for radical oxygen species

2013 ◽  
Vol 142-143 ◽  
pp. 662-667 ◽  
Author(s):  
Luis Domínguez Sánchez ◽  
Sébastien Francis Michel Taxt-Lamolle ◽  
Eli Olaug Hole ◽  
André Krivokapić ◽  
Einar Sagstuen ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Oxygen Species ◽  
Ambient Light ◽  
Radical Oxygen Species

scholarly journals Antioxidant and Anti-Inflammatory Strategies Based on the Potentiation of Glutathione Peroxidase Activity Prevent Endothelial Dysfunction in Chronic Kidney Disease

2018 ◽  
Vol 51 (3) ◽  
pp. 1287-1300 ◽  
Author(s):  
Manel Vera ◽  
Sergi Torramade-Moix ◽  
Susana Martin-Rodriguez ◽  
Aleix Cases ◽  
Josep M. Cruzado ◽  
...  
Keyword(s):  
Chronic Kidney Disease ◽  
Endothelial Dysfunction ◽  
Kidney Disease ◽  
Glutathione Peroxidase ◽  
Antioxidant Properties ◽  
Mitogen Activated Protein Kinase ◽  
Ros Generation ◽  
Oxygen Species ◽  
Radical Oxygen Species ◽  
Anti Inflammatory

Background/Aims: Accelerated atherosclerosis in chronic kidney disease (CKD) is preceded by endothelial dysfunction (ED), which exhibits a proinflammatory and prothrombotic phenotype and enhanced oxidative stress. In this study, the effect of several compounds with anti-inflammatory and/or antioxidant properties on uremia-induced endothelial dysfunction has been evaluated in an in vitro model. Methods: Endothelial cells (ECs) were exposed to sera from uremic patients in the absence and presence of the flavonoids apigenin, genistein and quercetin, the antioxidant enzyme mimetics (AEM) ebselen (glutathione peroxidase mimetic), EUK-134 and EUK-118 (both superoxide dismutase mimetics), and the pharmacological drug N-acetylcysteine (NAC). We explored changes in the expression of adhesion receptors on the cell surface, by immunofluorescence, the production of radical oxygen species (ROS), by fluorescence detection, and the activation of signaling proteins related to inflammation, by both a phosphospecific antibody cell-based ELISA and immunoblotting techniques. Results: Uremic media induced a significantly increased expression of ICAM-1, overproduction of radical oxygen species (ROS) and activation of p38 mitogen activated protein kinase (p38MAPK) and Nuclear Factor kB (NFkB) in ECs. Quercetin, the AEM and NAC showed a significant inhibitory effect on both ICAM-1 expression and ROS generation (p<0.05). All the compounds reduced p38MAPK activation, but only the AEM, especially ebselen, and NAC, both potentiating the glutathione peroxidase pathway, also inhibited NFkB activation. These two compounds were capable of increasing endothelial glutathione levels, especially in response to uremia. Conclusion: Our results indicate that the potentiation of the antioxidant pathways can be an effective strategy to improve endothelial dysfunction in uremia and a potential target to reduce the cardiovascular risk in this population.

scholarly journals Formation of Oxidatively Modified Lipids as the Basis for a Cellular Epilipidome

2020 ◽  
Vol 11 ◽  
Author(s):  
Corinne M. Spickett
Keyword(s):  
Biological Effects ◽  
Oxidative Modification ◽  
Oxygen Species ◽  
Radical Oxygen Species ◽  
Chemical Mechanisms ◽  
Control Gene Expression ◽  
Lipid Species ◽  
Regulatory Effects ◽  
Oxidatively Modified ◽  
The Stability

While often regarded as a subset of metabolomics, lipidomics can better be considered as a field in its own right. While the total number of lipid species in biology may not exceed the number of metabolites, they can be modified chemically and biochemically leading to an enormous diversity of derivatives, many of which retain the lipophilic properties of lipids and thus expand the lipidome greatly. Oxidative modification by radical oxygen species, either enzymatically or chemically, is one of the major mechanisms involved, although attack by non-radical oxidants also occurs. The modified lipids typically contain more oxygens in the form of hydroxyl, epoxide, carbonyl and carboxylic acid groups, and nitration, nitrosylation, halogenation or sulfation can also occur. This article provides a succinct overview of the types of species formed, the reactive compounds involved and the specific molecular sites that they react with, and the biochemical or chemical mechanisms involved. In many cases, these modifications reduce the stability of the lipid, and breakdown products are formed, which themselves have interesting properties such as the ability to react with other biomolecules. Publications on the biological effects of modified lipids are growing rapidly, supporting the concept that some of these biomolecules have potential signaling and regulatory effects. The question therefore arises whether modified lipids represent an “epilipidome”, analogous to the epigenetic modifications that can control gene expression.

scholarly journals Elevated production of radical oxygen species by polymorphonuclear neutrophils in cerebrospinal fluid infection

2012 ◽  
Vol 2 (1) ◽  
pp. 10 ◽  
Author(s):  
Anne-Claire Lukaszewicz ◽  
Geraldine Gontier ◽  
Valerie Faivre ◽  
Ingrid Ouanounou ◽  
Didier Payen
Keyword(s):  
Cerebrospinal Fluid ◽  
Polymorphonuclear Neutrophils ◽  
Oxygen Species ◽  
Radical Oxygen Species

The protective ability of Mediterranean dietary plants against the oxidative damage: The role of radical oxygen species in inflammation and the polyphenol, flavonoid and sterol contents

2009 ◽  
Vol 112 (3) ◽  
pp. 587-594 ◽  
Author(s):  
Filomena Conforti ◽  
Silvio Sosa ◽  
Mariangela Marrelli ◽  
Federica Menichini ◽  
Giancarlo A. Statti ◽  
...  
Keyword(s):  
Oxidative Damage ◽  
Oxygen Species ◽  
Radical Oxygen Species ◽  
Protective Ability ◽  
Dietary Plants

scholarly journals Role of Radical Oxygen Species in Rat Testicular Germ Cell Apoptosis Induced by Heat Stress

1999 ◽  
Vol 61 (2) ◽  
pp. 393-399 ◽  
Author(s):  
Masato Ikeda ◽  
Hideya Kodama ◽  
Jun Fukuda ◽  
Yasushi Shimizu ◽  
Masanori Murata ◽  
...  
Keyword(s):  
Heat Stress ◽  
Germ Cell ◽  
Cell Apoptosis ◽  
Oxygen Species ◽  
Radical Oxygen Species ◽  
Testicular Germ Cell ◽  
Germ Cell Apoptosis

scholarly journals Modulation of rat peripheral polymorphonuclear leukocyte response by nitric oxide and arginine

Blood ◽  
1994 ◽  
Vol 84 (8) ◽  
pp. 2741-2748 ◽  
Author(s):  
P Seth ◽  
R Kumari ◽  
M Dikshit ◽  
RC Srimal
Keyword(s):  
Nitric Oxide ◽  
Reactive Oxygen Species ◽  
Methylene Blue ◽  
Polymorphonuclear Leukocytes ◽  
Reactive Oxygen Species Generation ◽  
Oxygen Species ◽  
Superoxide Generation ◽  
No Donor ◽  
Radical Generation ◽  
Leukocyte Response

The effect of nitric oxide (NO) on the luminol-dependent chemiluminescence (LCL) response of rat polymorphonuclear leukocytes (PMNLs) was analyzed by using sodium nitroprusside (SNP), a NO donor, and L-arginine (L-arg), a NO precursor. A significant reduction in the LCL intensity was observed in presence of SNP (100 mumol/L) or L-arg (5 or 10 mmol/L) in arachidonic acid (AA) phorbol ester (PMA) and formyl- methionyl-leucyl-phenylalanine stimulated PMNLs. However, opsonized zymosan-induced LCL was not attenuated significantly. Reduction in hydroxyl radical and superoxide generation was also observed in SNP- or L-arg-pretreated cells. D-Arg (10 mmol/L) pretreatment did not inhibit PMNLs' LCL response. Furthermore, methylene blue (5 mumol/L) and L-NG- mono methyl-L-arginine (100 or 300 mumol/L) significantly attenuated the LCL response, as induced by various agonists. Cyclic GMP did not alter the reactive oxygen species generation from rat PMNLs. In addition, AA-induced release of myeloperoxidase, a marker of azurophilic granules, was found to be enhanced in L-arg- (10 mmol/L) pretreated PMNLs. The results suggest that NO inhibits free radical generation from rat PMNLs.

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