scholarly journals Formation of hydroxyl radicals from hydrogen peroxide in the presence of iron. Is haemoglobin a biological Fenton reagent?

1988 ◽  
Vol 249 (1) ◽  
pp. 185-190 ◽  
Author(s):  
A Puppo ◽  
B Halliwell
Keyword(s):  
Hydrogen Peroxide ◽  
Hydroxyl Radicals ◽  
Reactive Species ◽  
Iron Ions ◽  
Fenton Reagent ◽  
Low Concentrations ◽  
Free Haemoglobin ◽  
The Brain ◽  
Damaging Effects

The ability of oxyhaemoglobin and methaemoglobin to generate hydroxyl radicals (OH.) from H2O2 has been investigated using deoxyribose and phenylalanine as ‘detector molecules’ for OH.. An excess of H2O2 degrades methaemoglobin, releasing iron ions that react with H2O2 to form a species that appears to be OH.. Oxyhaemoglobin reacts with low concentrations of H2O2 to form a ‘reactive species’ that degrades deoxyribose but does not hydroxylate phenylalanine. This ‘reactive species’ is less amenable to scavenging by certain scavengers (salicylate, phenylalanine, arginine) than is OH., but it appears more reactive than OH. is to others (Hepes, urea). The ability of haemoglobin to generate not only this ‘reactive species’, but also OH. in the presence of H2O2 may account for the damaging effects of free haemoglobin in the brain, the eye, and at sites of inflammation.

scholarly journals Killing of Bacillus Spores by Aqueous Dissolved Oxygen, Ascorbic Acid, and Copper Ions

2003 ◽  
Vol 69 (4) ◽  
pp. 2245-2252 ◽  
Author(s):  
J. B. Cross ◽  
R. P. Currier ◽  
D. J. Torraco ◽  
L. A. Vanderberg ◽  
G. L. Wagner ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Ascorbic Acid ◽  
Dissolved Oxygen ◽  
Hydroxyl Radicals ◽  
Fenton Reaction ◽  
Copper Ions ◽  
Transition Metal Ions ◽  
Fenton Reagent ◽  
Bacillus Spores ◽  
Modified Fenton

ABSTRACT An approach to decontamination of biological endospores is discussed. Specifically, the performance of an aqueous modified Fenton reagent is examined. A modified Fenton reagent formulation of cupric chloride, ascorbic acid, and sodium chloride is shown to be an effective sporicide under aerobic conditions. The traditional Fenton reaction involves the conversion of hydrogen peroxide to hydroxyl radical by aqueous ionic catalysts such as the transition metal ions. Our modified Fenton reaction involves the conversion of aqueous dissolved oxygen to hydrogen peroxide by an ionic catalyst (Cu2+) and then subsequent conversion to hydroxyl radicals. Results are given for the modified Fenton reagent deactivating spores of Bacillus globigii. A biocidal mechanism is proposed that is consistent with our experimental results and independently derived information found in the literature. This mechanism requires diffusion of relatively benign species into the interior of the spore, where dissolved O2 is then converted through a series of reactions which ultimately produce hydroxyl radicals that perform the killing action.

Formation of Hydroxyl Radicals from Hydrogen Peroxide and Iron Salts by Superoxide- and Ascorbate-Dependent Mechanisms: Relevance to the Pathology of Rheumatoid Disease

1983 ◽  
Vol 64 (6) ◽  
pp. 649-653 ◽  
Author(s):  
D. A. Rowley ◽  
B. Halliwell
Keyword(s):  
Hydrogen Peroxide ◽  
Hydroxyl Radical ◽  
Hydroxyl Radicals ◽  
Oxygen Radicals ◽  
Rheumatoid Disease ◽  
Iron Salts ◽  
Low Concentrations ◽  
Short Period ◽  
Generating System

1. Superoxide and hydrogen peroxide are formed by activated phagocytes and react together in the presence of iron salts to form the hydroxyl radical, which attacks hyaluronic acid. Ascorbic acid also interacts with hydrogen peroxide and iron salts to form hydroxyl radical in a reaction independent of superoxide. Since iron salts, ascorbate and activated phagocytes are present in the rheumatoid joint, experiments were designed to see whether ascorbate-dependent or superoxide-dependent formation of hydroxyl radicals would be more important in vivo. 2. in the present study, addition of ascorbate to a superoxide-generating system at concentrations of 100 μmol/l provoked a superoxide-independent formation of hydroxyl radicals for a short period. Lower concentrations of ascorbate did not do this. It is therefore suggested that the superoxide-dependent reaction is probably more important. 3. It is further suggested that destruction of ascorbate by oxygen radicals formed by activated phagocytes accounts for the previously reported low concentrations of this compound in the serum and synovial fluid of rheumatoid patients.

scholarly journals The antioxidant action of human extracellular fluids. Effect of human serum and its protein components on the inactivation of α1-antiproteinase by hypochlorous acid and by hydrogen peroxide

1987 ◽  
Vol 243 (1) ◽  
pp. 219-223 ◽  
Author(s):  
M Wasil ◽  
B Halliwell ◽  
D C S Hutchison ◽  
H Baum
Keyword(s):  
Hydrogen Peroxide ◽  
Protective Effect ◽  
Hydroxyl Radicals ◽  
Hypochlorous Acid ◽  
Antioxidant Action ◽  
Serum Samples ◽  
Inhibitory Capacity ◽  
Low Concentrations ◽  
High Concentrations ◽  
Protein Components

The elastase-inhibitory capacity of purified human alpha 1-antiproteinase is inactivated by low concentrations of the myeloperoxidase-derived oxidant hypochlorous acid, but much higher concentrations are required to inhibit the elastase-inhibitory capacity of serum samples. The protective effect of serum appears to be largely due to albumin. High concentrations of H2O2 also inactivate the elastase-inhibitory capacity of alpha 1-antiproteinase, by a mechanism not involving formation of hydroxyl radicals. Serum offers protection against H2O2 inactivation of alpha 1-antiproteinase. The relevance of these results to the tissue damage produced by activated phagocytes is discussed.

scholarly journals Monitoring the heme iron state in horseradish peroxidase to detect ultratrace amounts of hydrogen peroxide in alcohols

RSC Advances ◽  
2021 ◽  
Vol 11 (17) ◽  
pp. 9901-9910
Author(s):  
Raheleh Ravanfar ◽  
Alireza Abbaspourrad
Keyword(s):  
Hydrogen Peroxide ◽  
Horseradish Peroxidase ◽  
Oxidative Damage ◽  
Heme Iron ◽  
Aqueous Systems ◽  
Iron State ◽  
Low Concentrations

Despite the importance of hydrogen peroxide (H2O2) in initiating oxidative damage and its connection to various diseases, the detection of low concentrations of H2O2 (<10 μM) is still limited using current methods, particularly in non-aqueous systems.

Antiapoptotic activity maintenance of Brain Derived Neurotrophic Factor and the C fragment of the tetanus toxin genetic fusion protein

2008 ◽  
Vol 3 (2) ◽  
pp. 105-112 ◽  
Author(s):  
Jesús Ciriza ◽  
Marcos García-Ojeda ◽  
Inmaculada Martín-Burriel ◽  
Cendra Agulhon ◽  
Francisco Miana-Mena ◽  
...  
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Neurotrophic Factor ◽  
Tetanus Toxin ◽  
Brain Derived Neurotrophic Factor ◽  
Trophic Factors ◽  
Low Concentrations ◽  
Neuro2a Cells ◽  
Genetic Fusion ◽  
The Brain ◽  
Lateral Sclerosis

AbstractNeurotrophic factors have been widely suggested as a treatment for multiple diseases including motorneuron pathologies, like Amyotrophic Lateral Sclerosis. However, clinical trials in which growth factors have been systematically administered to Amyotrophic Lateral Sclerosis patients have not been effective, owing in part to the short half-life of these factors and their low concentrations at target sites. A possible strategy is the use of the atoxic C fragment of the tetanus toxin as a neurotrophic factor carrier to the motorneurons. The activity of trophic factors should be tested because their genetic fusion to proteins could alter their folding and conformation, thus undermining their neuroprotective properties. For this purpose, in this paper we explored the Brain Derived Neurotrophic Factor (BDNF) activity maintenance after genetic fusion with the C fragment of the tetanus toxin. We demonstrated that BDNF fused with the C fragment of the tetanus toxin induces the neuronal survival Akt kinase pathway in mouse cortical culture neurons and maintains its antiapoptotic neuronal activity in Neuro2A cells.

scholarly journals Hormetic Concentrations of Hydrogen Peroxide but Not Ethanol Induce Cross-Adaptation to Different Stresses in Budding Yeast

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Halyna M. Semchyshyn
Keyword(s):  
Hydrogen Peroxide ◽  
Dose Response ◽  
Budding Yeast ◽  
Regulatory Protein ◽  
Colony Growth ◽  
Inhibitory Effect ◽  
Cross Resistance ◽  
Mild Stress ◽  
Low Concentrations ◽  
Cross Adaptation

The biphasic-dose response of microorganisms to hydrogen peroxide is a phenomenon of particular interest in hormesis research. In different animal models, the dose-response curve for ethanol is also nonlinear showing an inhibitory effect at high doses but a stimulatory effect at low doses. In this study, we observed the hormetic-dose response to ethanol in budding yeastS. cerevisiae. Cross-protection is a phenomenon in which exposure to mild stress results in the acquisition of cellular resistance to lethal stress induced by different factors. Since both hydrogen peroxide and ethanol at low concentrations were found to stimulate yeast colony growth, we evaluated the role of one substance in cell cross-adaptation to the other substance as well as some weak organic acid preservatives. This study demonstrates that, unlike ethanol, hydrogen peroxide at hormetic concentrations causes cross-resistance ofS. cerevisiaeto different stresses. The regulatory protein Yap1 plays an important role in the hormetic effects by low concentrations of either hydrogen peroxide or ethanol, and it is involved in the yeast cross-adaptation by low sublethal doses of hydrogen peroxide.

Effect of low concentrations of hydrogen peroxide on the contractile responses of rat detrusor smooth muscle strips

2010 ◽  
Vol 638 (1-3) ◽  
pp. 115-120 ◽  
Author(s):  
June Hyun Han ◽  
Moo Yeol Lee ◽  
Shin Young Lee ◽  
In Ho Chang ◽  
Hae Jong Kim ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Smooth Muscle ◽  
Detrusor Smooth Muscle ◽  
Contractile Responses ◽  
Low Concentrations

scholarly journals Hydrogen Peroxide Induces Hyphal Differentiation in Candida albicans

2008 ◽  
Vol 7 (11) ◽  
pp. 2008-2011 ◽  
Author(s):  
Olviyani Nasution ◽  
Kavitha Srinivasa ◽  
Minsun Kim ◽  
Yeo-Jung Kim ◽  
Wankee Kim ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Ascorbic Acid ◽  
Candida Albicans ◽  
Intracellular Concentration ◽  
Low Concentrations ◽  
Null Mutants

ABSTRACT In this study, we demonstrate that hyphal differentiation is induced by the subtoxic concentration of exogenous H2O2 in Candida albicans. This finding is confirmed by the changing intracellular concentration of H2O2. In order to induce the same level of differentiation, low concentrations of exogenous H2O2 are required for the null mutants of the thiol-specific antioxidant and catalase, while higher concentrations are needed for cells treated with ascorbic acid, an antioxidant chemical.

Removal of Proteinaceous Soils Using Hydroxyl Radicals Generated by the Electrolysis of Hydrogen Peroxide

2002 ◽  
Vol 250 (2) ◽  
pp. 409-414 ◽  
Author(s):  
Koreyoshi Imamura ◽  
Yoichiro Tada ◽  
Hirohumi Tanaka ◽  
Takaharu Sakiyama ◽  
Kazuhiro Nakanishi
Keyword(s):  
Hydrogen Peroxide ◽  
Hydroxyl Radicals
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