Differential determination of l-ascorbic acid and d-isoascorbic acid by reversed-phase high-performance liquid chromatography with electrochemical detection

Tsao, Constance S.; Salimi, Sanam

doi:10.1016/s0021-9673(00)88023-1

Cited by 62 publications

(15 citation statements)

References 16 publications

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“…Plasma and neutrophil ascorbate were determined by an HPLC method with electrochemical detection (Tsao and Salimi 1982) after deproteinisation with ortho-phosphoric acid. The mobile phase consisted of 0.05 M sodium phosphate, 0.05 M sodium acetate, 189 M dodecyltrimethylammonium chloride and 36.6 M tetraoctylammonium bromide in 25:75 methanol: H 2 O, pH 4.8.…”

Section: Plasma Vitamins Carotenes and Coenzyme Q Determinationmentioning

confidence: 99%

Supplementation with an antioxidant cocktail containing coenzyme Q prevents plasma oxidative damage induced by soccer

et al. 2008

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The aim of the study was to determine the effects of an antioxidant supplementation, which includes coenzyme Q(10), on plasma and neutrophil oxidative stress and the antioxidant response after a soccer match. Nineteen voluntary male pre-professional footballers were randomly and double-blinded treated with either a multivitamin and mineral supplement (n = 8) or a placebo (n = 11). After the 3 months of supplementation, the sportsmen played a friendly soccer match of 60 min. The 3-month supplementation induced higher plasma ascorbate and coenzyme Q levels when compared to the placebo group. Antioxidant supplementation influenced plasma oxidative stress markers because they were lower in the supplemented group than in the placebo one after the match. The football match induced decreased neutrophil vitamin E levels and catalase and glutathione peroxidase activities but increased glutathione reductase activity. Antioxidant diet supplementation prevented plasma oxidative damage but did not influence the neutrophil response to a football match.

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Section: Plasma Vitamins Carotenes and Coenzyme Q Determinationmentioning

confidence: 99%

Supplementation with an antioxidant cocktail containing coenzyme Q prevents plasma oxidative damage induced by soccer

et al. 2008

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“…Vitamin E was determined at 290 nm. Plasma ascorbate was determined by an HPLC method with electrochemical detection [10,36]. Immediately after plasma separation, samples were deproteinised with 30% trichloroacetic acid containing 2 mM EDTA.…”

Section: Plasma Vitamin Determinationsmentioning

confidence: 99%

Influence of vitamin C diet supplementation on endogenous antioxidant defences during exhaustive exercise

Tauler

Aguiló

Gimeno

et al. 2003

Pflugers Arch - Eur J Physiol

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We determined the effects of dietary vitamin C supplementation on erythrocyte antioxidant enzymes and on plasma antioxidants during athletic competition and short-term recovery. Blood samples were taken from 16 volunteer endurance athletes, participating in a duathlon competition, under basal conditions and both immediately and 1 h after the competition. The results were analysed taking into account the individual vitamin C intake and the plasma levels. Athletes were assigned to either the vitamin C-supplemented or control groups ( n=8 each). The control group had normal plasma ascorbate levels, the supplemented group high levels as a result of the higher vitamin C intake. Uric acid and lactate dehydrogenase increased after the competition only in the control group. Plasma ascorbate decreased after short-term recovery in the supplemented group. Erythrocyte catalase activity increased after the competition in the supplemented group. Glutathione peroxidase activity (determined with cumene hydroperoxide as substrate) increased only in the control group after short-term recovery. This pattern may suggest an important role for plasma ascorbate, and dietary vitamin C supplementation, in the defence against oxidative stress induced by exercise and in avoiding negative effects on erythrocyte integrity.

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“…Plasma vitamin C was determined by an HPLC method with electrochemical detection [17,46]. Plasma samples were deproteinized with cold perchloric acid (6%).…”

Section: Plasma Vitamin Determinationsmentioning

confidence: 99%

Diet supplementation with vitamin E, vitamin C and β-carotene cocktail enhances basal neutrophil antioxidant enzymes in athletes

Tauler

Aguiló

Fuentespina

et al. 2002

Pflugers Arch - Eur J Physiol

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Exercise increases oxygen consumption and causes a disturbance of intracellular pro-oxidant-antioxidant homeostasis. Few data are available as to the cumulative effects of exercise on the antioxidant defenses of the neutrophil. We studied the effects of 90 days' supplementation with placebo or an antioxidant cocktail of vitamin E (500 mg/day) and beta-carotene (30 mg/day) and the last 15 days also with vitamin C (1 g/day) on sportsmen's basal neutrophil antioxidant defenses. We analyzed the activities of catalase, glutathione peroxidase, glutathione reductase and the activities and levels of superoxide dismutase, glutathione and glutathione disulfide in neutrophils purified from antecubital vein blood of sportsmen before and after diet supplementation. Plasma vitamin E, beta-carotene and vitamin C concentrations in the antioxidant-supplemented group were approximately 1.6, 10, and 1.2 times higher respectively than those of the placebo group. The antioxidant-supplemented group presented a significantly higher glutathione versus glutathione disulfide ratio in neutrophils (about 20%) than the placebo one. Antioxidant supplementation enhances the antioxidant enzyme activity of superoxide dismutase and catalase in neutrophils.

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Differential determination of l-ascorbic acid and d-isoascorbic acid by reversed-phase high-performance liquid chromatography with electrochemical detection

Cited by 62 publications

References 16 publications

Supplementation with an antioxidant cocktail containing coenzyme Q prevents plasma oxidative damage induced by soccer

Supplementation with an antioxidant cocktail containing coenzyme Q prevents plasma oxidative damage induced by soccer

Influence of vitamin C diet supplementation on endogenous antioxidant defences during exhaustive exercise

Diet supplementation with vitamin E, vitamin C and β-carotene cocktail enhances basal neutrophil antioxidant enzymes in athletes

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