A relatively simple spectrophotometeric method has been developed for the determination of alpha tocopherol in human plasma. Method is modification of a previous micromethod base on oxidation of alpha tocopherol by ferric chloride. The complex of ferrous ions (generated in this reaction) with bathophenanthroline is determined spectrophotometrically at 536 nm. The absorbance of this colored comp...

The incidence of prostate cancer is increasing and there is continuing research into possible preventive treatments. Vitamin E, an antioxidant, has been studied as a chemoprotective agent in recent literature with α-Tocopherol being the most prominently studied. Although α-Tocopherol is found in highest concentration in the body, there are seven other isomers of vitamin E as tocopherols and toc...

Tocotrienols and tocopherols are isoforms of vitamin E. Vitamin E may exhibit antioxidant, prooxidant and non-antioxidant activities depending upon circumstances. In this study, the effect of tocotrienols and a-tocopherol on the activities of HMG CoA reductase and cholesterol 7 a-hydroxylase was investigated. Pure tocotrienols were isolated from palm fatty acid distillate and pure a-tocopherol ...

PURPOSE Alpha-Tocopherol is an essential micronutrient acting as an antioxidant in the retina. However, the molecular mechanism of its retinal uptake from the circulating blood remains to be determined. The purpose of this study was to elucidate the contribution of scavenger receptor class B, type I (SR-BI), to the uptake of high-density lipoprotein (HDL)-associated alpha-tocopherol (alpha-toco...

The aim of this study was to determine the effects of vitamin E (alpha-tocopherol) on the low density lipoprotein (LDL) receptor, a cell surface protein which plays an important role in controlling blood cholesterol. Human HepG2 hepatoma cells were incubated for 24 hours with increasing amounts of alpha, delta, or gamma-tocopherol. The LDL receptor binding activity, protein and mRNA, 3-hydroxy-...

The aim of this work was to compare protective and anti-apoptotic effects of α-tocopherol at nanomolar and micromolar concentrations against 0.2 mM H(2)O(2)-induced toxicity in the PC12 neuronal cell line and to reveal protein kinases that contribute to α-tocopherol protective action. The protection by 100 nM α-tocopherol against H(2)O(2)-induced PC12 cell death was pronounced if the time of pr...

The effect of alpha-tocopherol on the structure and phase behaviour of 1-palmitoyl-2-oleoyl-phosphatidylcholine was examined by real-time synchrotron X-ray diffraction and freeze-fracture electron microscopic methods. X-ray scattering intensity was recorded from mixed aqueous dispersions of phospholipid with 2.5, 5, 10 and 20 mol% alpha-tocopherol during temperature scans at 3 degrees /min betw...

A randomized, double-masked, crossover clinical trial was carried out to evaluate whether lovastatin therapy (60 mg daily) affects the initiation of oxidation of low density lipoprotein (LDL) in cardiac patients on a-tocopherol supplementation therapy (450 IU daily). Twenty-eight men with verified coronary heart disease and hypercholesterolemia received a-tocopherol with lovastatin or with dumm...

Tocopherols are a class of four natural compounds that can provide nutrition and function as antioxidant in both plants and animals. Maize kernels have low α-tocopherol content, the compound with the highest vitamin E activity, thus, raising the risk of vitamin E deficiency in human populations relying on maize as their primary vitamin E source. In this study, two insertion/deletions (InDels) w...

A new colorimetric method is proposed to determine α-tocopherol and its anti-oxidant activity by monitoring the ability of α-tocopherol to cause quantitative reduction of ferric ions. The method, based on Trinder reaction, includes incubating 1 μmol of ferric chloride in presence of 0 and 15 through 120 μmoles of α-tocopherol followed by detection of the iron (III) with standard mass of salicyl...