Alpha-tocopherol supplementation (50 mg daily for 5-8 years) reduced prostate cancer incidence by 32% in the alpha-Tocopherol, beta-Carotene Cancer Prevention Study. We investigated whether serum alpha-tocopherol or intake of vitamin E (eight tocopherols and tocotrienols) was associated with prostate cancer risk with up to 19 years of follow-up in the alpha-Tocopherol, beta-Carotene Cancer Prev...

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 (...

BACKGROUND Oxidative stress and inflammation are crucial in atherogenesis. alpha-Tocopherol is both an antioxidant and an antiinflammatory agent. OBJECTIVE We evaluated the effect of RRR-alpha-tocopherol supplementation on carotid atherosclerosis in patients with stable coronary artery disease (CAD) on drug therapy. DESIGN Randomized, controlled, double-blind trial compared RRR-alpha-tocoph...

A simple, sensitive and rapid spectrofluorimetric method for determination of α-tocopherol in pharmaceutical capsule and human plasma was developed and validated. The native fluorescence of α-tocopherol was measured at 334 nm with excitation at 291 nm, after extraction of α-tocopherol from human plasma hexane:dichloromethane mixture. The calibration curves were linear (R≥0.9993) in the concentr...

BACKGROUND Higher blood levels of alpha-tocopherol, the predominant form of vitamin E, have been associated in some studies with a reduced risk of lung cancer, but other studies have yielded conflicting results. To clarify this association, we examined the relationship between prospectively collected serum alpha-tocopherol and lung cancer in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention...

Although vitamin E can block mutagenesis and cell transformation in vitro and can reduce the number of chemically induced colonic adenomas in mice, previous clinical trials have found no protective effect of vitamin E supplements against colorectal adenomas, and epidemiological studies have found only weak protective effects of dietary or plasma alpha-tocopherol against colorectal cancer. We pr...

Rapeseed (Brassica napus L.) is the most important oil crop of temperate climates. Rapeseed oil contains tocopherols, also known as vitamin E, which is an indispensable nutrient for humans and animals due to its antioxidant and radical scavenging abilities. Moreover, tocopherols are also important for the oxidative stability of vegetable oils. Therefore, seed oil with increased tocopherol conte...

The effects of coenzyme Q(10) (CoQ(10)) and alpha-tocopherol on the rate of mitochondrial superoxide anion radical (O2(./-)) generation were examined in skeletal muscle, liver, and kidney of 24-month-old mice. Mice were orally administered alpha-tocopherol (200 mg.kg(-1).day(-1)) alone, CoQ(10) (123 mg.kg(-1).day(-1)) alone, or the two together for 13 wk. Administration of alpha-tocopherol resu...

The effect of -tocopherol treatment on gene expression in human aortic vascular smooth muscle cells was analyzed by gene expression arrays. The expression of the connective tissue growth factor (CTGF) gene was induced by -tocopherol 1.8-fold in gene array experiments, and similar results were also obtained by RT-PCR (1.7-fold) and at the protein level (1.4-fold). The antioxidants -tocopherol an...

Tocopherol (vitamin E) is a plant chloroplast lipid presumed to be involved in the response to oxidative stress. A tocopherol-deficient mutant (vte1) was isolated from Arabidopsis thaliana by using a TLC-based screening approach. Mutant plants lacked all four tocopherol forms and were deficient in tocopherol cyclase activity. Genetic mapping of vte1 and a genomics-based approach led to the iden...