Effects of scavengers of superoxide radicals, hydrogen peroxide, singlet oxygen and hydroxyl radicals on malondialdehyde generation from arachidonic acid by bovine seminal vesicle microsomes

1980 ◽  
Vol 36 (12) ◽  
pp. 1339-1340 ◽  
Author(s):  
J. de Vries ◽  
C. N. Verboom
Keyword(s):  
Hydrogen Peroxide ◽  
Arachidonic Acid ◽  
Singlet Oxygen ◽  
Seminal Vesicle ◽  
Hydroxyl Radicals ◽  
Superoxide Radicals

Chemical and biochemical aspects of superoxide radicals and related species of activated oxygen

1982 ◽  
Vol 60 (11) ◽  
pp. 1330-1345 ◽  
Author(s):  
Ajit Singh
Keyword(s):  
Hydrogen Peroxide ◽  
Hydroxyl Radicals ◽  
Superoxide Radical ◽  
Superoxide Radicals ◽  
Living Systems ◽  
Biological Processes ◽  
Oxygen Species ◽  
Peroxy Radicals ◽  
Activated Oxygen ◽  
Oxygen Yield

The spectrum of biological processes in which oxygen is used by living systems is quite large, and the products include some damaging species of activated oxygen, particularly the superoxide radical [Formula: see text] and hydrogen peroxide (H2O2). Superoxide radicals and hydrogen peroxide, in turn, can lead to the formation of other damaging species: hydroxyl radicals (∙OH) and singlet oxygen (1O2). Hydroxyl radicals react with organic compounds to give secondary free radicals that, in the presence of oxygen, yield peroxy radicals, peroxides, and hydroperoxides. Formation, interconversion, and reactivity of [Formula: see text] and related activated oxygen species, methods available for their detection, and the basis of their biological toxicity are briefly reviewed.

scholarly journals 367 Scavenging Capacity of Active Oxygen Species in Blackberry

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 455E-455
Author(s):  
Shiow Y. Wang ◽  
Hongjun Jiao
Keyword(s):  
Hydrogen Peroxide ◽  
Ascorbic Acid ◽  
Singlet Oxygen ◽  
Hydroxyl Radicals ◽  
Fruit Juice ◽  
Active Oxygen Species ◽  
Active Oxygen ◽  
Oxygen Species ◽  
Scavenging Capacity ◽  
Β Carotene

The effect of blackberries (Rubus sp.) genotypes on antioxidant activities against superoxide radicals (O2–), hydrogen peroxide (H2O2), hydroxyl radicals (OH), and singlet oxygen (O,), was evaluated. The results were expressed as percent inhibition of active oxygen species production in the presence of fruit juice. The active oxygen radical absorbance capacity (ORAC) value referred to the net protection in the presence of fruit juice, and was expressed as micromoles of α-tocopherol, ascorbate, α-tocopherol, and β-carotene equivalents per 10 g of fresh weight for O2–, H2O2, OH, and O2, respectively. Among the different cultivars, juice of Hull' blackberry had the highest oxygen species, superoxide radicals (O2–), hydrogen peroxide (H2O2), hydroxyl radicals (OH), and singlet oxygen (O2,) scavenging capacity. Different antioxidants have their functional scavenging capacity against active oxygen species. There were interesting and marked differences among the different antioxidants in their abilities to inhibit the different active oxygen species. β-carotene had by far the highest scavenging activity against O2– but had absolutely no effect on H2O2. Ascorbic acid was the best at inhibiting H2O2 free radical activity. For OH, there was a wide range of scavenging capacities with α-tocopherol the highest and ascorbic acid the lowest. Glutathione had higher O2– scavenging capacity compared to the other antioxidants.

Study on N-Demethylation of N,N-Dimethyl-4-aminoazobenzene and N-Nitrosamines by Prostaglandin H Synthase

1997 ◽  
Vol 62 (6) ◽  
pp. 971-980 ◽  
Author(s):  
Marie Stiborová ◽  
Eva Frei ◽  
Heinz H. Schmeiser
Keyword(s):  
Hydrogen Peroxide ◽  
Arachidonic Acid ◽  
Free Radicals ◽  
Seminal Vesicle ◽  
Oxidation Mechanism ◽  
Maximal Velocity ◽  
Prostaglandin H Synthase ◽  
Michaelis Constant ◽  
Prostaglandin H

The in vitro enzymatic metabolism of carcinogenic N,N-dimethyl-4-aminoazobenzene, N-nitroso-N-methylaniline and N-nitroso-N,N-dimethylamine was investigated using ram seminal vesicle microsomal prostaglandin H synthase. Both N-nitrosamines are not converted by the studied enzyme. Formaldehyde is produced by the prostaglandin H synthase catalyzed reaction from N,N-dimethyl-4-aminoazobenzene. Arachidonic acid and hydrogen peroxide serve as cofactors for the oxidation of N,N-dimethyl-4-aminoazobenzene. The apparent Michaelis constant and the maximal velocity values for N,N-dimethyl-4-aminoazobenzene as a substrate are 64 μmol/l and 51.2 nmol HCHO/min/mg protein, respectively. In addition to formaldehyde, N-methyl-4-aminoazobenzene and 4-aminoazobenzene, two unknown substances are the products of the N,N-dimethyl-4-aminoazobenzene oxidation. The oxidation of N,N-dimethyl-4-aminoazobenzene catalyzed by prostaglandin H synthase is inhibited by glutathione, ascorbate and NADH. The results suggest that prostaglandin H synthase metabolizes N,N-dimethyl-4-aminoazobenzene through a one-electron oxidation mechanism, giving rise to free radicals.

scholarly journals Ferrous ion-EDTA-stimulated phospholipid peroxidation. A reaction changing from alkoxyl-radical- to hydroxyl-radical-dependent initiation

1984 ◽  
Vol 224 (3) ◽  
pp. 697-701 ◽  
Author(s):  
J M C Gutteridge
Keyword(s):  
Hydrogen Peroxide ◽  
Lipid Peroxidation ◽  
Hydroxyl Radical ◽  
Hydroxyl Radicals ◽  
Superoxide Radicals ◽  
Ferrous Ion ◽  
Radical Scavengers ◽  
Alkoxyl Radical ◽  
Phospholipid Peroxidation ◽  
Hydroxyl Radical Scavengers

The stimulatory effect of ferrous salts on the peroxidation of phospholipids can be enhanced by EDTA when the concentration of Fe2+ in the reaction is greater than that of EDTA. Hydroxyl-radical scavengers do not inhibit peroxidation until the concentrations of Fe2+ and EDTA in the reaction are equal. Lipid peroxidation is then substantially initiated by hydroxyl radicals derived from a Fenton-type reaction requiring hydrogen peroxide. Superoxide radicals appear to play some role in the formation of initiating species.

Curculigo orchioides Protects Cisplatin-Induced Cell Damage

2013 ◽  
Vol 41 (02) ◽  
pp. 425-441 ◽  
Author(s):  
Tong Ho Kang ◽  
Bin Na Hong ◽  
Su-Young Jung ◽  
Jeong-Han Lee ◽  
Hong-Seob So ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Lipid Peroxidation ◽  
Hydroxyl Radicals ◽  
Cell Damage ◽  
Superoxide Radicals ◽  
Ros Generation ◽  
Protective Mechanism ◽  
Dependent Manner ◽  
Protective Effects ◽  
Curculigo Orchioides

Cisplatin is commonly used as a chemotherapeutic agent against many human cancers. However, it generates reactive oxygen species (ROS) and has serious dose-limiting side effects, including ototoxicity. The roots of Curculigo orchioides (C. orchioides) have been used to treat auditory diseases such as tinnitus and hearing loss in Chinese traditional medicine. In the present study, we investigated the protective effects of an ethanol extract obtained from C. orchioides rhizome (COR) on cisplatin-induced cell damage in auditory cells (HEI-OC1). COR (2.5–25 μg/ml) inhibited cisplatin-induced HEI-OC1 cell damage in a dose-dependent manner. To investigate the protective mechanism of COR on cisplatin cytotoxicity in HEI-OC1 cells, we measured the effects of COR on ROS generation and lipid peroxidation in cisplatin-treated cells as well as its scavenging activities against superoxide radicals, hydroxyl radicals, hydrogen peroxide, and DPPH radicals. COR (1–25 μg/ml) had scavenging activities against superoxide radicals, hydroxyl radicals, hydrogen peroxide, and DPPH radicals, as well as reduced lipid peroxidation. In in vivo experiments, COR was shown to reduce cochlear and peripheral auditory function impairments through cisplatin-induced auditory damage in mice. These results indicate that COR protects from cisplatin-induced auditory damage by inhibiting lipid peroxidation and scavenging activities against free radicals.

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