Determination of serum alpha-tocopherol (vitamin E) by high-performance liquid chromatography.

Leenheer, A.P. De; Bevere, V O De; Cruyl, Annie A.; Claeys, A.

doi:10.1093/clinchem/24.4.585

Cited by 84 publications

(14 citation statements)

References 7 publications

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“…Estimation of serum α-tocopherol is carried out as described by Andre r et al ., using High Performance Liquid Cromatography (HPLC) system at 292 nm with isocratic gradient pump. [ 13 ]…”

Section: Methodsmentioning

confidence: 99%

Low plasma antioxidant status in patients with epilepsy and the role of antiepileptic drugs on oxidative stress

Menon

Ravindran

Kumar

2014

Ann Indian Acad Neurol

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Background:Oxidative stress has been implicated in various disorders including epilepsy. We studied the antioxidant status in patients with epilepsy and aimed at determining whether there was any difference in the antioxidant levels between patients and controls, patients who are not on antiepileptic drugs (AEDs), and on treatment, between individual AEDs and patients on monotherapy and polytherapy.Materials and Methods:Antioxidant levels like catalase, glutathione peroxidase (GPx), vitamin E, glutathione (GSH), thiol group (SH), uric acid, and total antioxidant capacity (TAC) were compared between 100 patients with epilepsy and equal number of controls. Twenty-five patients who were not on AEDs were compared with patients on AEDs and the control group. Patients were divided into monotherapy and polytherapy group and antioxidant status was compared between the two groups and between individual drugs.Results:Catalase, SH, vitamin E, and TAC were significantly low in patients with epilepsy than those in the control group (P < 0.001). GSH and uric acid did not show any difference; GPx in patients was significantly higher than those in the control group There were no differences in the antioxidant levels between the treated and the untreated groups; however, it was lower in untreated patients than controls (P < 0.001), suggesting that AEDs do not modify the oxidative stress. Patients on Valproate (VPA) showed higher catalase and GPx levels. Catalase was higher in the monotherapy than polytherapy group (P < 0.04).Conclusion:Our study found significantly low levels of antioxidant in patients as compared to controls. AED did not influence the antioxidant status suggesting that seizures induce oxidative stress.

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“…Estimation of serum α-tocopherol is carried out as described by Andre r et al ., using High Performance Liquid Cromatography (HPLC) system at 292 nm with isocratic gradient pump. [ 13 ]…”

Section: Methodsmentioning

confidence: 99%

Low plasma antioxidant status in patients with epilepsy and the role of antiepileptic drugs on oxidative stress

Menon

Ravindran

Kumar

2014

Ann Indian Acad Neurol

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“…Vitamin A and E were determined by a modified method of MILLER and YANG (1985) and DE LEENHEER et al (1978) with an isocratic reversed-phase high-performance liquid chromatography (HPLC) system. Vitamin A and E were separated on a RP-18 column (4 x 125 mm, 5 pm, Fa.…”

Section: Methodsmentioning

confidence: 99%

Effect of gestation and lactation on lipoprotein pattern and composition in dairy cows¹

Schweigert

1990

Animal Physiology Nutrition

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Zusammenfassung Einfluß der Trächtigkeit und der Laktation auf das Lipoproteinmuster und die Lipoproteinzusammensetzung von Milchkühen Die Konzentration der Lipide und fettlöslichen Vitamine (Vitamin A und E, β‐Carotin) wurde im Serum und in den Lipoproteinfraktionen über einen Zeitraum von 3 Monaten bei 14 Kühen und Kalbinnen bestimmt. Im Kolostrum war die Konzentration der fettlöslichen Vitamine 10mal höher als in der reifen Milch. Die Serumlipide zeigten mit Ausnahme der Triglyceride einen deutlichen Abfall zur Geburt hin, um dann wieder anzusteigen. Bei den Lipoproteinfraktionen waren die “very low density” Lipoproteine (VLDL) vor der Geburt bis zu 5mal höher als während der Laktation. Der Abfall der VLDL‐Fraktion fand um den Geburtszeitpunkt statt. Im Gegensatz dazu begann die “low density” Lipoproteinfraktion (LDL) parallel zur Serumkonzentration bereits 3–4 Wochen vor der Geburt abzusinken. Niedrigste Werte wurden um die Geburt erreicht, um dann erneut auf Werte anzusteigen, die um etwa 25% niedriger waren als vor der Geburt. Der deutliche Abfall der VLDL Fraktion um die Geburt, ist mit der Bedeutung dieser Fraktion für den Lipidtransfer während der Laktation zu erklären. Die hohe Konzentration der fettlöslichen Vitamine und Cholesterin im Kolostrum bei mehr oder weniger unveränderter Triglyceridkonzentration im Vergleich zur reifen Milch, ebenso wie die deutliche Übereinstimmung des Verhaltens der LDL‐Fraktion und den IgGl im Serum weist darauf hin, daß die fettlöslichen Vitamine und Cholesterin über einen anderen Weg in das Kolostrum gelangen als die Triglyceride. Wegen der deutlichen kontinuierlichen Änderung der LDL‐Fraktion um den Geburtszeitpunkt ist ein LDL‐Rezeptor‐abhängiger Transfer von Vitamin E, β‐Carotin und Cholesterin in das Kolostrum am wahrscheinlichsten.

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“…Plasma MDA levels were measured by a spectrophotometric assay by using the commercially available Bioxyteck kit (OXIS International Inc., Foster City, CA, USA). Serum vitamin C and vitamin E were measured by high‐performance liquid chromatography as previously described 11, 12 …”

Section: Patientsmentioning

confidence: 99%

Effects of phlebotomy therapy on cytochrome P450 2e1 activity and oxidative stress markers in dysmetabolic iron overload syndrome: a randomized trial

Lainé

Reymann

Morel

et al. 2006

Aliment Pharmacol Ther

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SUMMARY AimTo assess the effects of iron removal on cytochrome P450 2E1 activity and oxidative stress in dysmetabolic iron overload syndrome. MethodsForty-eight patients were randomized to phlebotomy therapy consisting of removal of 300-500 mL of blood every 14 days until serum ferritin levels dropped under 100 lg/L or to follow-up without phlebotomy therapy. Cytochrome P450 2E1 activity was measured at baseline and at the end of treatment by using the 6-hydroxychlorzoxazone/chlorzoxazone blood metabolic ratio, 2 h after the intake of 500 mg of chlorzoxazone. ResultsIn the treatment group, a mean of 3.9 AE 1.3 L of blood was removed and serum ferritin levels dropped from 715 AE 397 to 74 AE 34 lg/L. Variation of cytochrome P450 2E1 activity was not significantly different between the 2 groups (0.07 AE 0.26 vs. 0.03 AE 0.19, P ¼ 0.36). In the treatment group, low-density lipoprotein cholesterol and vitamin E were lowered after treatment compared with control group ()0.15 AE 0.51 vs. 0.24 AE 0.58, P ¼ 0.002 and )1.3 AE 4.4 vs. 2.3 AE 5.2, P ¼ 0.03, respectively). Inversely, vitamin C was increased (0.5 AE 3.5 vs. )1.8 AE 3.9, P ¼ 0.03). ConclusionsIn dysmetabolic iron overload syndrome, reduction of iron stores does not significantly influence cytochrome P450 2E1 activity but is associated with a significant decrease of low-density lipoprotein cholesterol, suggesting that venesection therapy may be a suitable option in these patients.

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Determination of serum alpha-tocopherol (vitamin E) by high-performance liquid chromatography.

Cited by 84 publications

References 7 publications

Low plasma antioxidant status in patients with epilepsy and the role of antiepileptic drugs on oxidative stress

Low plasma antioxidant status in patients with epilepsy and the role of antiepileptic drugs on oxidative stress

Effect of gestation and lactation on lipoprotein pattern and composition in dairy cows¹

Effects of phlebotomy therapy on cytochrome P450 2e1 activity and oxidative stress markers in dysmetabolic iron overload syndrome: a randomized trial

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Determination of serum alpha-tocopherol (vitamin E) by high-performance liquid chromatography.

Cited by 84 publications

References 7 publications

Low plasma antioxidant status in patients with epilepsy and the role of antiepileptic drugs on oxidative stress

Low plasma antioxidant status in patients with epilepsy and the role of antiepileptic drugs on oxidative stress

Effect of gestation and lactation on lipoprotein pattern and composition in dairy cows1

Effects of phlebotomy therapy on cytochrome P450 2e1 activity and oxidative stress markers in dysmetabolic iron overload syndrome: a randomized trial

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Effect of gestation and lactation on lipoprotein pattern and composition in dairy cows¹