Search results for "Oxidation-Reduction"
showing 10 items of 689 documents
Solid-State Electrochemical Assay of Heme-Binding Molecules for Screening of Drugs with Antimalarial Potential
2013
The interaction between heme and ligands is the basis for a variety of tests aimed at the discovery of antiplasmodial molecules. Two electrochemical methods for the screening of molecules with potential antimalarial activity through heme-binding mechanism are described. The first method is applicable to lipophilic environment, by using solution phase electrochemistry in DMSO solutions of Fe(III)-heme plus the tested compounds at carbon electrodes. This method provides well-defined voltammetric signals, characteristic of the heme-ligand (L) interaction. The second method involves aqueous media at biological pH and the use of voltammetry of immobilized particles, by means of microparticulate …
Membrane protein oxidation determines neuronal degeneration
2015
Oxidative stress is an early hallmark in neurodegenerative disorders such as Alzheimer's and Parkinson's diseases. However, the critical biochemical effector mechanisms of oxidative neurotoxicity have remained surprisingly elusive. In screening various peroxides and potential substrates of oxidation for their effect on neuronal survival, we observed that intramembrane compounds were significantly more active than aqueous or amphiphilic compounds. To better understand this result, we synthesized a series of competitive and site-specific membrane protein oxidation inhibitors termed aminoacyllipids, whose structures were designed on the basis of amino acids frequently found at the protein-lipi…
Genotoxicity of 1,4-benzoquinone and 1,4-naphthoquinone in relation to effects on glutathione and NAD(P)H levels in V79 cells.
1989
1,4-Benzoquinone is cytotoxic in V79 Chinese hamster cells and induces gene mutations and micronuclei. The cell-damaging effects of quinones are usually attributed to thiol depletion, oxidation of NAD(P)H, and redox-cycling involving the formation of semiquinone radicals and reactive oxygen species. To elucidate the role of these mechanisms in the genotoxicity of 1,4-benzoquinone, we measured various genotoxic effects, cytotoxicity, and the levels of glutathione, NADPH, NADH, and their oxidized forms all in the same experiment. 1,4-Naphthoquinone, which does not induce gene mutations in V79 cells, was investigated for comparative reasons. The quinones had a similar effect on the levels of c…
Oxidative Stress, Induced by Sub-Lethal Doses of BDE 209, Promotes Energy Management and Cell Cycle Modulation in the Marine Fish Cell Line SAF-1
2019
The effects of sub-lethal doses of polybrominated diphenyl ether (PBDE)-209 in terms of toxicity, oxidative stress, and biomarkers were evaluated in the Sparus aurata fibroblast cell line (SAF-1). Vitality and oxidative stress status were studied after incubation with PBDE for 72 h. Concomitantly, the quantification of proteins related to cell cycle and DNA repair (p53), cell proliferation (extracellular signal&ndash
Lafora disease fibroblasts exemplify the molecular interdependence between thioredoxin 1 and the proteasome in mammalian cells
2013
13 páginas, 8 figuras (que no aparecen en este documento, se pueden consultar en: http://www.sciencedirect.com/science/article/pii/S0891584913003274#ec0005)
Interplay of oxidants and antioxidants during exercise: Implications for muscle health
2010
Muscle contraction results in generation of reactive oxygen and nitrogen species (RONS) at a rate determined by the intensity, frequency, and duration of the exercise protocols. Strenuous exercise causes oxidation of protein, lipid, and DNA, release of cytosolic enzymes, and other signs of cell damage; however, only exhaustive exercise is detrimental. Indeed, the regulation of vascular tone, the excitation-contraction coupling, growth, and differentiation in skeletal muscle, are governed in part by RONS. This is accomplished by RONS interaction with redox-sensitive transcription factors, leading to increased gene expression of antioxidant enzymes, cytoprotective proteins, and other enzymes …
A nuclear glutathione cycle within the cell cycle
2010
The complex antioxidant network of plant and animal cells has the thiol tripeptide GSH at its centre to buffer ROS (reactive oxygen species) and facilitate cellular redox signalling which controls growth, development and defence. GSH is found in nearly every compartment of the cell, including the nucleus. Transport between the different intracellular compartments is pivotal to the regulation of cell proliferation. GSH co-localizes with nuclear DNA at the early stages of proliferation in plant and animal cells. Moreover, GSH recruitment and sequestration in the nucleus during the G1- and S-phases of the cell cycle has a profound impact on cellular redox homoeostasis and on gene expression. F…
Changes in carnitine octanoyltransferase activity induce alteration in fatty acid metabolism
2011
The peroxisomal beta oxidation of very long chain fatty acids (VLCFA) leads to the formation of medium chain acyl-CoAs such as octanoyl-CoA. Today, it seems clear that the exit of shortened fatty acids produced by the peroxisomal beta oxidation requires their conversion into acyl-carnitine and the presence of the carnitine octanoyltransferase (CROT). Here, we describe the consequences of an overexpression and a knock down of the CROT gene in terms of mitochondrial and peroxisomal fatty acids metabolism in a model of hepatic cells. Our experiments showed that an increase in CROT activity induced a decrease in MCFA and VLCFA levels in the cell. These changes are accompanied by an increase in …
Improved synthesis and in vitro evaluation of the cytotoxic profile of oxysterols oxidized at C4 (4α- and 4β-hydroxycholesterol) and C7 (7-ketocholes…
2013
Whereas the biological activities of oxysterols oxidized at C7 (7-ketocholesterol (7KC), 7β-hydroxycholesterol (7β-OHC), 7α-hydroxycholesterol (7α-OHC)) are well documented, those of oxysterols oxidized at C4 (4β-hydroxycholesterol (4β-OHC), 4α-hydroxycholesterol (4α-OHC)) are not well known, especially on the cells of the central nervous system. Therefore, an improved methodology has been validated for 4β-OHC and 4α-OHC synthesis, and the effects on cell viability and cell growth of these molecules were studied on immortalized, tumoral and normal brain cells (158N, C6 and SK-N-BE cells, and mixed primary cultures of astrocytes and oligodendrocytes). Whereas inhibition of cell growth with 7…
Diffusion of Oxygen through Cork Stopper: Is It a Knudsen or a Fickian Mechanism?
2014
International audience; The aim of this work is to identify which law governs oxygen transfer through cork: Knudsen or Fickian mechanism. This is important to better understand wine oxidation during post-bottling aging. Oxygen transfer through cork wafers is measured at 298 K using a manometric permeation technique. Depending on the mechanism, we can extract the transport coefficients. Increasing the initial pressure of oxygen from 50 to 800 hPa leads to a change in the values of the transport coefficients. This implies that oxygen transport through cork does not obey the Knudsen law. From these results, we conclude that the limiting step of oxygen transport through cork occurs in the cell …