A spectrophotometric method was used to determine the total tocopherol levels in platelets, plasma, and erythrocytes from human subjects. The platelets contained about three times as much total tocopherol per cell as erythrocytes. This difference was not related to the content of polyunsaturated fatty acids in platelets and erythrocytes. In vitro incubation resulted in significant uptake of toc...

Nonenzymatic glycation of low density lipoprotein (LDL) is a reaction of glucose and other reducing sugars with apolipoprotein B100 (apo-B100) lysine residues. In diabetes, this reaction is greatly accelerated and is important in the pathogenesis of diabetic complications. The objective of this study was to investigate in vitro effects of ?-tocopherol, ascorbic acid and lycopene on LDL glycatio...

The effects of graded levels of Flora GLO (FG), a dietary supplement containing lutein derived from marigold flowers, on tissue concentrations of lutein and alpha- and gamma-tocopherol were determined. Six groups of male weanling Fischer 344 rats (15/group) were fed ad libitum modified AIN-93G diets containing 0%, 0.30%, 0.60%, 1.20%, 2.40%, or 4.80% FG for eight weeks. FG provided 0%, 0.015%, ...

BACKGROUND Clinical studies of the associations of vitamin E with lung function have reported conflicting results. However, these reports primarily examine the α-tocopherol isoform of vitamin E and have not included the isoform γ-tocopherol which we recently demonstrated in vitro opposes the function of α-tocopherol. We previously demonstrated, in vitro and in animal studies, that the vitamin E...

The effect of DL-alpha-tocopherol on the differentiation of the mouse myeloid leukemia cell line (M1) was investigated using fluorometry. The reliability of the fluorometric determination was verified by the mutual overlapping of the curves of disappearance of the radioactivity recovered as alpha-tocopherol and the loss of its fluorescence. alpha-Tocopherol solubilized into the culture medium w...

OBJECTIVE Lipid-soluble antioxidants are associated with a lower incidence for many chronic diseases of aging, possibly by preventing damage from chronic inflammation. In the current study, we compared serum levels of coenzyme Q₁₀ (CoQ₁₀), α-tocopherol, γ-tocopherol, and C-reactive protein (CRP) between adolescent girls and premenopausal women to assess changes from childhood to midlife. METH...

BACKGROUND Little is known about α-tocopherol's bioavailability as a constituent of food or its dependence on a subject's age. OBJECTIVE To evaluate the α-tocopherol bioavailability from food, we used collard greens grown in deuterated water ((2)H collard greens) as a source of deuterium-labeled ((2)H) α-tocopherol consumed by younger and older adults in a post hoc analysis of a vitamin K stu...

BACKGROUND Vitamin E compounds exhibit prostate cancer preventive properties experimentally, but serologic investigations of tocopherols, and randomized controlled trials of supplementation in particular, have been inconsistent. Many studies suggest protective effects among smokers and for aggressive prostate cancer, however. METHODS We conducted a nested case-control study of serum α-tocophe...

The pregnane X receptor (PXR) has been postulated to play a role in the metabolism of a-tocopherol owing to the up-regulation of hepatic cytochrome P450 (P450) 3A in human cell lines and murine models after a-tocopherol treatment. However, in vivo studies confirming the role of PXR in a-tocopherol metabolism in humans presents significant difficulties and has not been performed. PXR-humanized (...

AIMS ICAM-1-dependent leukocyte recruitment in vivo is inhibited by the vitamin E isoform d-α-tocopherol and elevated by d-γ-tocopherol. ICAM-1 is reported to activate endothelial cell signals including protein kinase C (PKC), but the PKC isoform and the mechanism for ICAM-1 activation of PKC are not known. It is also not known whether ICAM-1 signaling in endothelial cells is regulated by tocop...