scholarly journals Redox cycling of anthracyclines by cardiac mitochondria. II. Formation of superoxide anion, hydrogen peroxide, and hydroxyl radical.

1986 ◽  
Vol 261 (7) ◽  
pp. 3068-3074 ◽  
Author(s):  
J H Doroshow ◽  
K J Davies
Keyword(s):  
Hydrogen Peroxide ◽  
Hydroxyl Radical ◽  
Superoxide Anion ◽  
Redox Cycling ◽  
Cardiac Mitochondria

Evaluation of antioxidant activity of Melothria maderaspatana in vitro

2010 ◽  
Vol 5 (2) ◽  
pp. 224-230 ◽  
Author(s):  
Boobalan Raja ◽  
Kodukkur Pugalendi
Keyword(s):  
Hydrogen Peroxide ◽  
Antioxidant Activity ◽  
Free Radical ◽  
Hydroxyl Radical ◽  
Superoxide Anion ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Free Radical Scavenging ◽  
Melothria Maderaspatana

AbstractIn this study, an aqueous extract of leaves from Melothria maderaspatana was tested for in vitro antioxidant activity. Free radical scavenging assays, such as hydroxyl radical, hydrogen peroxide, superoxide anion radical and 2,2-diphenyl-1-picryl hydrazyl (DPPH), 2,2’-azinobis-(3-ethyl-enzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, and reducing power assay, were studied. The extract effectively scavenged hydroxyl radical, hydrogen peroxide and superoxide anion radicals. It also scavenged DPPH and ABTS radicals. Furthermore, it was found to have reducing power. All concentrations of leaf extract exhibited free radical scavenging and antioxidant power, and the preventive effects were in a dose-dependent manner. The antioxidant activities of the above were compared to standard antioxidants such as butylated hydroxytoluene (BHT), ascorbic acid, and α-tocopherol. The results obtained in the present study indicate that the M. maderaspatana extract could be considered a potential source of natural antioxidant.

Beta-2-Agonists Have Antioxidant Function in vitro. 1. Inhibition of Superoxide Anion, Hydrogen Peroxide, Hypochlorous Acid and Hydroxyl Radical

Respiration ◽  
1997 ◽  
Vol 64 (1) ◽  
pp. 16-22 ◽  
Author(s):  
Adrian Gillissen ◽  
Malgorzata Jaworska ◽  
Birgit Schärling ◽  
Dominique van Zwoll ◽  
Gerhard Schultze-Werninghaus
Keyword(s):  
Hydrogen Peroxide ◽  
Hydroxyl Radical ◽  
Superoxide Anion ◽  
Hypochlorous Acid ◽  
Antioxidant Function ◽  
Beta 2

The oxidation of toluene sorbed on activated carbon in the presence of H2O2 and manganese oxide

2012 ◽  
Vol 66 (11) ◽  
pp. 2349-2354 ◽  
Author(s):  
Si-Hyun Do ◽  
Sung-Ho Kong
Keyword(s):  
Hydrogen Peroxide ◽  
Electron Transfer ◽  
Activated Carbon ◽  
Control System ◽  
Hydroxyl Radical ◽  
Manganese Oxide ◽  
Superoxide Anion ◽  
Gas Flow ◽  
Pure Water ◽  
Gas Purging

We investigated the oxidation of toluene sorbed on activated carbon (AC) in the presence of hydrogen peroxide (H2O2) and pyrolusite (MnO2). Sorbed toluene was prepared by reacting a toluene-saturated solution and AC. The amounts of sorbed toluene (mg of toluene/g of AC) decreased as the amounts of AC were increased. The reaction was conducted in a gas-purging (GP) reactor and the gas flow at the outlet of a GP reactor was carefully maintained. As a result, the percentage of toluene captured by ORBO tube was 28% in the control system with pure water. When H2O2 was catalyzed by AC (i.e. this forms a hydroxyl radical by electron transfer), approximately 17% of the desorbed toluene was oxidized and 68% of toluene remained on AC which was similar to the control system. However, when pyrolusite (650 mg/L) was added together with H2O2 (10,000 mg/L), only 5% of toluene was captured by the ORBO tube and 55% of toluene remained on AC, which indicated that both desorbed and sorbed toluene was oxidized. Moreover, toluene oxidation increased when concentrations of pyrolusite and H2O2 were increased. It was suggested that superoxide anion, which is generated by the reaction of H2O2 and pyrolusite, might stimulate toluene desorption and then toluene in the aqueous phase could be oxidized by hydroxyl radical.

scholarly journals Rhodanese Rdl2 produces reactive sulfur species to scavenge hydroxyl radical and protect mitochondria

2021 ◽  
Author(s):  
Qingda Wang ◽  
Zhigang Chen ◽  
Xi Zhang ◽  
Yuping Xin ◽  
Yongzhen Xia ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Hydroxyl Radical ◽  
Superoxide Anion ◽  
Fenton Reaction ◽  
Aerobic Respiration ◽  
Oxygen Species ◽  
Sulfur Species ◽  
Ex Ante ◽  
Generate Superoxide Anion

During aerobic respiration, mitochondria generate superoxide anion (O2&middot−), hydrogen peroxide (H2O2), and hydroxyl radical (HO·), and these reactive oxygen species (ROS) are detrimental to mitochondria. Mitochondrial damage is linked to a broad spectrum of pathologies such as Alzheimer's disease, hemochromatosis, and diabetes. Mitochondria contain several enzymes for rapidly removing superoxide anion and hydrogen peroxide, but how they antagonize HO· is elusive, representing a loophole in the anti-ROS system. Herein, we discovered that Rhodanese 2 (Rdl2) is critical for maintaining the functionality and integrity of mitochondria under sub-lethal ROS stress in Saccharomyces cerevisiae. Rdl2 converts stable sulfur species (thiosulfate and dialkyl polysulfide) to reactive sulfane sulfur including persulfide that protects mitochondrial DNA via scavenging HO·. Surprisingly, hydrogen sulfide (H2S) promotes HO· production through stimulating the Fenton reaction, leading to increased DNA damage. Our study may reveal an ex-ante mean for antagonizing HO·, patching the loophole of the anti-ROS system in mitochondria.

Reactive forms of oxygen and chemiluminescence in phagocytizing rabbit alveolar macrophages

1978 ◽  
Vol 235 (3) ◽  
pp. C103-C108 ◽  
Author(s):  
P. R. Miles ◽  
V. Castranova ◽  
P. Lee
Keyword(s):  
Hydrogen Peroxide ◽  
Superoxide Dismutase ◽  
Hydroxyl Radical ◽  
Alveolar Macrophages ◽  
Superoxide Anion ◽  
Extracellular Fluid ◽  
Particle Uptake ◽  
O2 Production

Chemiluminescence (CL), superoxide anion (O2-) production, and particle uptake were measured to determine the role of antibacterial substances in the chemiluminescent response associated with phagocytosis in rabbit alveolar macrophages (AM). Exposure of AM to zymosan particles induced both CL and the production of extracellular O2-. CL is inhibited by superoxide dismutase, an enzyme which catalyzes the conversion of O2- to hydrogen peroxide (H2O2), by catalase, an enzyme which destroys H2O2, and by the hydroxyl radical (.OH) scavengers, benzoate and ethanol. Superoxide dismutase and catalase probably exert their effects in the extracellular fluid. CL can also be produced by the addition of NaO2 or H2O2 to zymosan in a noncellular system. The chemiluminescent response occurs before particle uptake is complete, which also indicates that CL occurs in the extracellular fluid. These results suggest that CL induced by zymosan in AM is due to the extracellular reaction between various reactive forms of oxygen and zymosan.

scholarly journals Suurstoftoksisiteit

1990 ◽  
Vol 9 (3) ◽  
pp. 118-123
Author(s):  
C. A. Van der Westhuizen ◽  
M. Viljoen ◽  
M. J. Pitout ◽  
P. H. Van Papendorp
Keyword(s):  
Hydrogen Peroxide ◽  
Endoplasmic Reticulum ◽  
Hydroxyl Radical ◽  
Singlet Oxygen ◽  
Superoxide Anion ◽  
Energy Production ◽  
Plasma Membranes ◽  
The Body ◽  
Toxic Metabolites ◽  
Oxygen Metabolites

Oxygen has been discovered about 200 years ago. Since then the vital physiological involvement of oxygen in various biologi­cal processes, mainly energy production, has been established. However, in the body molecular oxygen can be converted to toxic oxygen metabolites such as superoxide anion, hydrogen peroxide, the hydroxyl radical and singlet oxygen. These toxic metabolites are produced mainly in the mitochondria, plasma membranes and endoplasmic reticulum.

235 MANGALARGA STALLION SPERM IS HIGHLY SUSCEPTIBLE TO THE HYDROXYL RADICAL

2011 ◽  
Vol 23 (1) ◽  
pp. 216
Author(s):  
J. R. C. Gurgel ◽  
M. Nichi ◽  
E. G. A. Perez ◽  
P. A. A. Góes ◽  
A. Dalmazzo ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Lipid Peroxidation ◽  
Hydroxyl Radical ◽  
Superoxide Anion ◽  
Activity Level ◽  
Lower Percentage ◽  
Sperm Chromatin ◽  
Mitochondrial Activity ◽  
Computer Assisted

Mangalarga, due to its marching abilities, is the mostly widespread and numerous equine breed in Brazil. Furthermore, previous studies indicate that the semen of these horses is particularly susceptible to cryo-injuries. Therefore, the use of chilled semen is crucial when employing reproductive biotechnologies. However, previous studies indicate that chilled semen is highly impaired by the oxidative stress, which is caused by reactive oxygen species (ROS). An alternative to overcome the injuries caused by oxidative stress is antioxidant treatment, which requires the identification of those ROS that are the most deleterious. The aim of this study was to identify the most harmful ROS to Mangalarga sperm. Semen samples from 4 horses were collected, mixed with chilling media (Equimix®, Nutricell) and transported to the laboratory at 15°C. Samples were then incubated (1 h, 37°C) with 4 ROS inducing mechanisms: xanthine/xanthine oxidase (produces superoxide anion), hydrogen peroxide (4 mM), ascorbate and ferrous sulfate (4 mM; produces hydroxyl radical). Samples were analysed for motility using computer assisted sperm analysis (CASA). The 3-3′ diaminobenzidine stain was used as an index of mitochondrial activity, the eosin nigrosin stain as an index of membrane integrity, the simple stain (fast green/Bengal rose) as an index of acrosome integrity, sperm chromatin structure assay (SCSA) as an index of DNA fragmentation, and the measurement of thiobarbituric acid reactive substances (TBARS) an index of lipid peroxidation. Statistical analysis was performed using the SAS System for Windows (SAS Institute Inc., Cary, NC, USA; least significant differences test and Spearman correlation; P < 0.05). Results showed that Mangalarga sperm is highly susceptible to the hydroxyl radical. Samples treated with this ROS showed a lower percentage of sperm with high mitochondrial activity then samples treated with hydrogen peroxide (24.6 ± 5.9 v. 43.7 ± 6.8%, respectively). Similarly, lipid peroxidation (TBARS) was higher in samples treated with hydroxyl radical when compared with those treated with both superoxide anion and hydrogen peroxide (2037.7 ± 154.8, 681.2 ± 170.1, and 789.4 ± 124.5 ng/106 sperm). In addition, for all variables analysed using CASA except for ALH and BCF, samples treated with hydroxyl radical showed decreased quality when compared with the other samples. A positive correlation was found between TBARS and mitochondrial activity, indicating that the higher the sperm susceptibility of sperm against oxidative stress, the lower the mitochondrial activity. Level of TBARS also correlated negatively with most of the variables evaluated by CASA. The present results suggest that Mangalarga sperm is highly susceptible to the hydroxyl radical, a mechanism apparently related to the mitochondrial activity. Therefore, an alternative to overcome the deleterious influence of oxidative stress in semen of Mangalarga stallions would be the treatment with hydroxyl radical scavengers such as vitamins C and E, reduced glutathione, and other nonenzymatic antioxidants. The authors acknowledge Nutricell for the media used and CAPES for financial support.

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