Serum concentrations of retinol, alpha-tocopherol, beta-carotene and lycopene were measured by reversed-phase high-performance liquid chromatography (r-P HPLC) in 260 randomly selected healthy adult Kuwaitis (159 men and 101 women) aged 18-63 years (mean 33.3 years) to established reference ranges of the micronutrient antioxidants. Total cholesterol concentrations were assayed by an enzymatic m...

Much data support a role for both low density lipoprotein (LDL) oxidation and glycation in atherogenesis. While alpha-tocopherol decreases the oxidative susceptibility of LDL, its role in decreasing LDL glycation is unclear. Hence we tested the effect of alpha-tocopherol both in vitro and in vivo on LDL oxidation and glycation. LDL was isolated after enrichment of plasma with alpha-tocopherol. ...

Three experiments were conducted to estimate the effects of single intramuscular (IM) administrations of vitamin E on blood plasma and tissue concentrations of alpha-tocopherol in sheep. In Expt 1, plasma kinetics of alpha-tocopherol in sheep (n 30) were investigated following IM administration of three doses (ten sheep/dose) of DL-alpha-tocopheryl acetate, (20, 40 and 60 mg/kg live weight). Pl...

Diabetes mellitus is a risk factor for cerebrovascular ischemic disease. Aspirin (acetylsalicylic acid) is the most widely used drug for the secondary prevention of thrombotic phenomena. It has been also recently demonstrated that alpha-tocopherol influenced in vitro the antiplatelet effect of aspirin. The aim of the present study is to evaluate the effects aspirin plus alpha-tocopherol on cere...

BACKGROUND Vitamin E supplementation has been recommended for persons with familial hypobetalipoproteinemia (FHBL), a rare disorder of lipoprotein metabolism that leads to low serum alpha-tocopherol and decreased LDL-cholesterol and apolipoprotein (apo) B. We examined the effect of truncated apoB variants on vitamin E metabolism and oxidative stress in persons with FHBL. METHODS We studied 9 ...

We studied the effect of different concentrations of alpha-tocopherol on in vitro cupric ions induced oxidation of low density lipoproteins (LDL). Human native LDL (50 µg protein/ml) oxidation was induced by 10 µmol/L of CuSO4. Conjugated dienes were measured spectrophotometrically for up to 440 minutes. The length of the lag phase (Tlag), maximum velocity of the reaction (Vmax) and the maximum...

Postabsorptive elimination of the various forms of vitamin E appears to play a key role in regulation of tissue tocopherol concentrations, but mechanisms of tocopherol metabolism have not been elucidated. Here we describe a pathway involving cytochrome P450-mediated omega-hydroxylation of the tocopherol phytyl side chain followed by stepwise removal of two- or three-carbon moieties, ultimately ...

The influence of prolonged breastfeeding on breast-milk alpha tocopherol was assessed in 112 lactating mothers practicing exclusive breast-feeding on term infants. The cross sectional study was carried out between May 1st and 30th, 2005 at the University of Benin/University of Benin Teaching Hospital, Benin City among lactating mothers. Employing the Quaife's method, mean alpha-tocopherol value...

BACKGROUND Disorders of antioxidant balance are considered to be involved in the toxicity associated with radiotherapy or chemotherapy. PATIENTS AND METHODS Serum alpha-tocopherol and retinol were determined, by high performance liquid chromatography, before and during therapy with a combination of paclitaxel and carboplatin in 28 patients with breast and ovarian cancer. Serum neopterin and c...

BACKGROUND: The aim of our investigation was to estimate the stability of alpha-tocopheryl O-glycosides in relation to activity of exoglycosidases in selected rat tissues. MATERIAL AND METHODS: Acetylated glycosides were obtained in glucosidation of alpha-tocopherol using the Helferich method. The activity of exoglycosidases was determined by the Zwierz et al. method. Protein concentrations wer...