Formation of 8-Hydroxydeoxyguanosine from Deoxyguanosine by Fe2+/Ascorbic Acid/EDTA/H2O2 System.

Yoshimura, Yoshihiro; Matsuzaki, Yumi; Uchiyama, Katsumi; Watanabe, Takaho; Ohsawa, Keiko; Imaeda, Kazuo

doi:10.3164/jcbn.15.155

Cited by 3 publications

(3 citation statements)

References 14 publications

(10 reference statements)

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“…The concentration of supersaturated H 2 water was found to be 2•73 mmol/l. Hydroxyl radicals were generated by the Fenton reaction described by Yoshimura et al (17) , with some modifications. The reaction mixture (1 ml) was as follows: 1•37 mmol H 2 /l, 5 mmol HEPES buffer (pH 7•5)/l, 5 μmol ammonium iron (II) sulphate/l, 0•5 mmol EDTA/l, 0•5 mmol L-ascorbic acid/l and 1•25 mmol L-phenylalanine/l.…”

Section: In Vitro Effect Of Hydrogen Molecule On Hydroxyl Radicalsmentioning

confidence: 99%

Hydrogen produced in rat colon improves in vivo reduction–oxidation balance due to induced regeneration of α-tocopherol

et al. 2019

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We investigated whether non-digestible saccharide fermentation-derived hydrogen molecules (H2) in rat colon could improve the in vivo reduction–oxidation (redox) balance via regeneration of α-tocopherol, by assessing their effect on hydroxyl radicals, the α-tocopherol concentration and the redox balance. In Expt 1, a Fenton reaction with phenylalanine (0 or 1·37 mmol/l of H2) was conducted. In Expt 2, rats received intraperitoneally maize oil containing phorone (400 mg/kg) 7 d after drinking ad libitum water containing 0 or 4 % fructo-oligosaccharides (FOS) (groups CP and FP, respectively). In Expt 3, rats unable to synthesise ascorbic acid drank ad libitum for 14 d water with 240 mg ascorbic acid/l (group AC), 20 mg of ascorbic acid/l (group DC) or 20 mg of ascorbic acid/l and 4 % FOS (group DCF). In the Fenton reaction, H2 reduced tyrosine produced from phenylalanine to 72 % when platinum was added and to 92 % when platinum was excluded. In Expt 2, liver glutathione was depleted by administration of phorone to rats. However, compared with CP, no change in the m-tyrosine concentration in the liver of FP was detected. In Expt 3, net H2 excretion was higher in DCF than in the other rats after 3 d of the experiment. Furthermore, the concentrations of H2 and α-tocopherol and the redox glutathione ratio in perirenal adipose tissue of rats were significantly higher in DCF than in DC. To summarise, in rat colon, fermentation-derived H2 further shifted the redox balance towards a more reducing status in perirenal adipose tissue through increased regeneration of α-tocopherol.

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Section: In Vitro Effect Of Hydrogen Molecule On Hydroxyl Radicalsmentioning

confidence: 99%

Hydrogen produced in rat colon improves in vivo reduction–oxidation balance due to induced regeneration of α-tocopherol

et al. 2019

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“…The ESR signal intensity of this mixture was then taken to measure the yield of the inhibition of • OH by MRP. The inhibition rate of • OH was determined by the ratio of peak height of the second signal from the DMPO-OH spin adduct to the third signal of Mn 2+ and compared to the ratio of control (Yoshimura et al, 1993). The measurement conditions of an ESR were as follows: temperature, ambient; microwave power, 8 mW; magnetic field, 336 ( 5 mT; sweep time, 2 min; modulation frequency, 100 kHz; modulation amplitude, 0.063 mT; receiver gain, 2 × 100; time constant, 0.03 s.…”

Section: Dialysis Of Mrpmentioning

confidence: 99%

“…Determination of Inhibition Rate on O2 -. Fifty microliters of 2 mM hypoxanthine, 50 µL of 0.05 M HEPES buffer solution (pH 7.4), 50 µL of MRP, 10 µL of DMPO, and 50 µL of 0.4 unit/mL xanthine oxidase were stirred together successively to determine the ability of MRP to inhibit O2 - (Yoshimura et al, 1993). The inhibition rate of O2 -was determined by taking the ratio of the peak height of the first signal from the DMPO-OH spin adduct to the third signal of Mn 2+ , and the ratio was compared to that of control value.…”

Section: Dialysis Of Mrpmentioning

confidence: 99%

Antioxidative Effect of Maillard Reaction Products Using Glucose−Glycine Model System

Yoshimura

Iijima

Watanabe

et al. 1997

J. Agric. Food Chem.

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176

107

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Using a glucose-glycine system as a Maillard reaction model, the rate of inhibition toward active oxygen by Maillard reaction products (MRP) was investigated by electron spin resonance (ESR). MRP obtained through heating a glucose-glycine mixture for 1 h inhibited more than ca. 90% of active oxygen species existing in the form of hydroxyl radicals ( • OH) in the sample and decreased its inhibition power as heating time increased. Studies have revealed the direct scavenging activity of MRP along with the depression of the Fenton reaction, which is brought about by the strong chelating ability of MRP with Fe 2+ due to the inhibition of • OH. Moreover, the decrease in the inhibition activity toward • OH during the prolonged heating period can be explained by the increase in reducing power of MRP promoting the reduction of Fe 3+ to Fe 2+ , and thus, activating the Fenton reaction. The high molecular weight fraction obtained from MRP, because of its stronger metalchelating capability, inhibited • OH more efficiently than the low molecular weight fraction. In addition, MRP obtained after 1 h of heat treatment exhibited ca. 14% inhibition of superoxide anion (O 2 -), indicating a lower rate of inhibition compared to that of • OH, which can be explained by the contribution of trace amounts of O 2 -formation during the early stage of glucose-glycine reaction.

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Competitive reactions of peroxynitrite with 2′-deoxyguanosine and 7,8-dihydro-8-oxo-2′-deoxyguanosine (8-oxodG): Relevance to the formation of 8-oxodG in DNA exposed to peroxynitrite

Uppu

Cueto

Squadrito

et al. 1996

Free Radical Biology and Medicine

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Formation of 8-Hydroxydeoxyguanosine from Deoxyguanosine by Fe2+/Ascorbic Acid/EDTA/H2O2 System.

Cited by 3 publications

References 14 publications

Hydrogen produced in rat colon improves in vivo reduction–oxidation balance due to induced regeneration of α-tocopherol

Hydrogen produced in rat colon improves in vivo reduction–oxidation balance due to induced regeneration of α-tocopherol

Antioxidative Effect of Maillard Reaction Products Using Glucose−Glycine Model System

Competitive reactions of peroxynitrite with 2′-deoxyguanosine and 7,8-dihydro-8-oxo-2′-deoxyguanosine (8-oxodG): Relevance to the formation of 8-oxodG in DNA exposed to peroxynitrite

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