The relative contributions of vitamin E, urate, ascorbate and proteins to the total peroxyl radical-trapping antioxidant activity of human blood plasma

Wayner, Danial D. M.; Burton, Graham W.; Ingold, K. U.; Barclay, L. R. C.; Locke, Steven J.

doi:10.1016/0304-4165(87)90155-3

Cited by 824 publications

(436 citation statements)

References 37 publications

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“…Thus, it is suggested that the resistance of cord plasma to Cu 2 -mediated lipid peroxidation observed in the current study is at least partly due to circulating levels of urate, albumin, bilirubin and sulphydryl groups. Urate is a powerful hydrophilic antioxidant and is a scavenger of singlet oxygen (Ames et al, 1981) and peroxyl radicals (Wayner et al, 1987). Urate can also act as a plasma antioxidant by binding transition metal ions (Becker, 1993).…”

Section: Discussionmentioning

confidence: 99%

“…Plasma sulphydryl groups are thought to represent the ®rst line of defence against peroxyl radicals, and the most expendable source of antioxidants in plasma, as there is no known mechanism of regeneration once they are oxidised (Wayner et al, 1987). Sonani et al, (1994) found that albumin and sulphydryl proteins were prominent in scavenging carbon-centred free radicals under anaerobic conditions in plasma, where ascorbate, vitamin E and nonsulphydryl amino acids were ineffective.…”

Section: Discussionmentioning

confidence: 99%

“…Plasma sulphydryl concentrations were determined by a modi®cation of the method of Ellman (1959), as described by Wayner et al, (1987).Phosphate buffer (900 ml of 0.2 M Na 2 HPO 4 , pH 9.0, containing 2 mM EDTA and 1% s.d.S), 100 ml of plasma and 20 ml of DTNB stock solution (10 mM in 0.05 M phosphate buffer pH 7.0) were added to a semimicrocuvette. Following 25 min incubation at room temperature, absorbance was read at 412 nm.…”

Section: Methodsmentioning

confidence: 99%

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Low molecular weight plasma antioxidants and lipid peroxidation in maternal and cord blood

et al. 1999

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Objective: To determine the concentrations of the low molecular weight antioxidants urate, bilirubin, albumin and sulphydryl groups and to measure lipid peroxidation levels in pair-matched maternal and cord blood plasma. Design: Venous blood plasma concentrations of urate, bilirubin, albumin and sulphydryls were determined in healthy pregnant women and in pair matched umbilical cords. The ability of maternal and cord plasma to withstand Cu 2 -induced lipid peroxidation was assessed by measuring the production of thiobarbituric acid reactive substances (TBARS) over time in plasma incubated with Cu 2 . Subjects: Forty healthy women, between 10 and 20 weeks gestation, were recruited randomly from an antenatal clinic. Venous blood samples were obtained from the mothers at the recruitment stage and from the umbilical cords of their newborn after delivery. Results: Urate, bilirubin and sulphydryls were present in signi®cantly higher concentrations (P`0.001) in cord plasma than in maternal plasma. Albumin levels were similar in mothers and cords. Signi®cantly lower levels (P 0.018) of TBARS were produced in cord plasma compared with maternal plasma following incubation with Cu 2 . There were signi®cant correlations between albumin and sulphydryl concentrations in maternal plasma (r 0.43, P 0.007) and between urate concentrations in maternal and cord plasma (r 0.37, P 0.026). Conclusion: Urate, bilirubin and sulphydryls are present in signi®cantly higher concentrations in cord blood than in maternal blood. The increased levels of these antioxidants in cord plasma may contribute to the increased resistance of cord plasma to Cu 2 -induced lipid peroxidation.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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Low molecular weight plasma antioxidants and lipid peroxidation in maternal and cord blood

et al. 1999

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“…Several plasma components will Plasma total homocysteine, oxidative damage and antioxidant activity SJ Moat et al contribute to this activity including uric acid, albumin, thiols and a-tocopherol (Miller et al, 1993). Plasma thiols have been shown to contribute to various measures of antioxidant activity Miller et al, 1993;Wayner et al, 1987) and there may have been changes in the redox state of plasma thiols following a reduction in plasma total homocysteine. There is current interest in the potential antioxidant role for folate, but a doubling in plasma folate was associated with such a small increase in TAOC that it is unlikely that there is a direct causative association.…”

Section: Effect On Antioxidant Activitymentioning

confidence: 99%

Reduction in plasma total homocysteine through increasing folate intake in healthy individuals is not associated with changes in measures of antioxidant activity or oxidant damage

et al. 2003

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Background: Various mechanisms have been proposed to explain the association between plasma total homocysteine (tHcy) and risk of cardiovascular disease, including oxidative activity of homocysteine. Objective: To explore the putative role of reactive oxygen species in the association between plasma tHcy and risk of cardiovascular disease in healthy individuals. Design: A double-blind, placebo-controlled crossover intervention to increase folate intake through diet (increased consumption of folate-rich foods) and supplement (400 mg folic acid) was carried out in 126 healthy men and women. Measurements were made of antioxidant activity in red blood cells and plasma, and products of oxidant damage in plasma. Results: Diet and supplement-based interventions led to an increase in measures of folate status and a reduction in plasma tHcy. This was not associated with any significant change in measures of antioxidant activity (plasma and red blood cell glutathione peroxidase activity and red blood cell superoxide dismutase activity) or oxidant damage (plasma malondialdehyde), although an improvement in plasma total antioxidant capacity just failed to reach significance. Conclusions: In healthy individuals lowering plasma tHcy does not have any functional implications regarding oxidative damage.

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“…Again, lipid peroxidation is a free radical-mediated oxidative deterioration of polyunsaturated fatty acid residues in membrane lipids, resulting in the formation of lipid hydroperoxide (Wayner et al, 1987) [36]. Malondial-dehydes, the peroxidative end product of unsaturated fatty acids, are water soluble; when they are free they could dissipate from erythrocyte into the plasma (Jain, 1988) [37].…”

Section: Discussionmentioning

confidence: 99%

Modulation of Antioxidant Status of Erythrocyte of In Vivo Heat Exposed Rats Fed on Altered Dietary Protein Level

2017

IJCRR

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This study was carried out to determine the effect of altered dietary protein level on the antioxidant status of erythrocytes of in vivo heat exposed rats. Experiments were performed on adult (80-90 days old) male Wister strain rats, divided in six groups of five animals each. Animals were exposed to 43±1 °C, ambient humidity conditions for 3 h daily for 15 days in a well maintained climatic chamber. Increased TBARS productions were found when measured in packed erythrocytes and erythrocyte membranes in both the rats fed on 18% or 6% protein diet after acute and chronic heat exposure. Supplementation of ascorbic acid to the rats fed on 18% or 6% protein diet was found to reduce the TBARS production remarkably in packed erythrocytes while it further raised the TBARS production in erythrocyte membrane in response to chronic and acute heat exposure. The liberation of alanine increased in 18% protein-fed as well as 6% protein-fed rats following chronic and acute exposure to heat. Decreased GSH content and increased membrane total thiol (-SH) content of erythrocytes were observed in both 18% protein-fed and 6% protein-fed rats. Prior supplementation of ascorbic acid was found to restore partially the GSH content of erythrocyte and to potentiate the increase in membrane total thiol (-SH) content in both adequately protein-fed and protein-restricted groups of rats.

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The relative contributions of vitamin E, urate, ascorbate and proteins to the total peroxyl radical-trapping antioxidant activity of human blood plasma

Abstract: The relative contributions of vitamin E, urate, ascorbate and proteins to the total peroxyl radical-trapping antioxidant activity of human blood plasma Wayner, D. D. M.; Burton, G.W.; Ingold, K. U.; Barclay, L. R. C.; Locke, S. J.

Cited by 824 publications

References 37 publications

Low molecular weight plasma antioxidants and lipid peroxidation in maternal and cord blood

Low molecular weight plasma antioxidants and lipid peroxidation in maternal and cord blood

Reduction in plasma total homocysteine through increasing folate intake in healthy individuals is not associated with changes in measures of antioxidant activity or oxidant damage

Modulation of Antioxidant Status of Erythrocyte of In Vivo Heat Exposed Rats Fed on Altered Dietary Protein Level

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