Vitamin E Research Today is a free monthly online journal that collates and summarizes the latest research about Vitamin E, including details on benefits, dosage, supplements, antioxidants.

Bid integrates intrinsic and extrinsic signaling in apoptosis induced by alpha-tocopheryl succinate in human gastric carcinoma cells.

Zhao Y, Li R, Xia W, Neuzil J, Lu Y, Zhang H, Zhao X, Zhang X, Sun C, Wu K

Department of Nutrition and Food, Harbin Medical University, Harbin, China.

The underlying mechanisms of alpha-tocopheryl succinate (alpha-TOS)-mediated apoptosis are not understood in detail, although the redox-silent vitamin E analog is a potent apoptogen and anti-cancer agent. Our previous studies showed the important role of Fas signaling in apoptosis induced by the mitocan. The objective of the present study was to investigate whether apoptosis triggered by alpha-TOS in gastric carcinomas cells involves both mitochondria- and death receptor-dependent pathways. alpha-TOS induced apoptosis and mitochondrial permeability transition in a concentration- and time-dependent manner. As a consequence, cytochrome c and the apoptosis-inducing factor were released and caspases were activated. Bax was translocated from the cytosol to mitochondria and Bid was cleaved into its truncated form, tBid. Knocking down Bid by RNAi and Fas antisense oligodeoxynucleotides resulted in a decreased release and cleavage. The results imply that Bid may serve as a critical integrating factor of the death receptor and mitochondrial pathway in alpha-TOS-mediated apoptosis.

Published 1 February 2010 in Cancer Lett, 288(1): 42-9.
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Articles on Vitamin E published 28 January 2010:

Pretreatment with a combination of quercetin and alpha-tocopherol ameliorates adenosine triphosphatases and lysosomal enzymes in myocardial infarcted rats.   Life Sci, 86(5): 178-84.

AIMS: Membrane bound adenosine triphosphatases (ATPases) and lysosomal enzymes play an important role in the pathology of myocardial infarction. This study was aimed to evaluate the combined preventive effects of quercetin and alpha-tocopherol on membrane bound ATPases and lysosomal enzymes in isoproterenol induced myocardial infarcted rats. MAIN METHODS: Male Wistar rats were pretreated with a combination of quercetin (10mg/kg) and alpha-tocopherol (10mg/kg) daily for 14 days. After the ... [Abstract] [Full-text]

Articles on Vitamin E published 14 January 2010:

Alpha-tocopherol succinate protects mice from gamma-radiation by induction of granulocyte-colony stimulating factor.   Int J Radiat Biol, 86(1): 12-21.

PURPOSE: The purpose of this study was to further elucidate the role of granulocyte-colony stimulating factor (G-CSF)-induced in response to alpha-tocopherol succinate (TS) administration in protecting mice from total body irradiation (TBI). MATERIAL AND METHODS: The dose, route, and schedule of TS administration for optimal G-CSF induction were determined by giving TS through subcutaneous (sc) and oral routes to male CD2F1 mice. The level of cytokine in serum was determined by multiplex ... [Abstract] [Full-text]

Anti-proliferative effects of gamma-tocotrienol on mammary tumour cells are associated with suppression of cell cycle progression.   Cell Prolif, 43(1): 77-83.

OBJECTIVES: Previous studies have shown that gamma-tocotrienol induces potent anti-proliferative effects on +SA mammary tumour cells in culture; here, investigations have been conducted to determine its effects on intracellular signalling proteins involved in regulating cell cycle progression. MATERIALS AND METHODS: +SA cells were maintained in mitogen-free defined media containing 0 or 4 micromgamma-tocotrienol, for 48 h to synchronize cell cycle in G(0) phase, and then they were exposed to ... [Abstract] [Full-text]

Articles on Vitamin E published 28 December 2009:

Synergistic actions of atorvastatin with gamma-tocotrienol and celecoxib against human colon cancer HT29 and HCT116 cells.   Int J Cancer, 126(4): 852-63.

The synergistic actions of atorvastatin (ATST) with gamma-tocotrienol (gamma-TT) and celecoxib (CXIB) were studied in human colon cancer cell lines HT29 and HCT116. The synergistic inhibition of cell growth by ATST and gamma-TT was demonstrated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and isobologram analysis. delta-TT exhibited a similar inhibitory action when combined with ATST. Mevalonate and geranylgeranyl pyrophosphate eliminated most of the growth ... [Abstract] [Full-text]

Articles on Vitamin E published 24 December 2009:

Variegate porphyria induces plasma and neutrophil oxidative stress: effects of dietary supplementation with vitamins E and C.   Br J Nutr, 103(1): 69-76.

Our aim was to analyse the influence of variegate porphyria (VP) on the antioxidant defenses and markers of oxidative damage and inflammation in plasma and neutrophils and the effects of dietary supplementation with vitamins E and C on these parameters in plasma, neutrophils and erythrocytes. Twelve women affected by VP and twelve pair-matched healthy control women participated in a double-blind crossover study. Each participant took 50 mg/d of vitamin E and 150 mg/d of vitamin C, or a placebo, ... [Abstract] [Full-text]

Articles on Vitamin E published 22 December 2009:

Intersection of the tocopherol and plastoquinol metabolic pathways at the plastoglobule.   Biochem J, 425(2): 389-99.

Plastoglobules, lipid-protein bodies in the stroma of plant chloroplasts, are enriched in non-polar lipids, in particular prenyl quinols. In the present study we show that, in addition to the thylakoids, plastoglobules also contain a considerable proportion of the plastidial PQ-9 (plastoquinol-9), the redox component of photosystem II, and of the cyclized product of PQ-9, PC-8 (plastochromanol-8), a tocochromanol with a structure similar to gamma-tocopherol and gamma-tocotrienol, but with a ... [Abstract] [Full-text]

Articles on Vitamin E published 16 December 2009:

Diet and serum micronutrients in relation to cervical neoplasia and cancer among low-income Brazilian women.   Int J Cancer, 126(3): 703-14.

Cervical cancer is a leading cancer among women in developing countries. Infection with oncogenic human papillomavirus (HPV) types has been recognized as a necessary cause of this disease. Serum carotenoids and tocopherols have also been associated with risk for cervical neoplasia, but results from previous studies were not consistent. We evaluated the association of serum total carotene and tocopherols, and dietary intakes with the risk of newly diagnosed, histologically confirmed cervical ... [Abstract] [Full-text]

Articles on Vitamin E published 30 November 2009:

The role of alpha-tocopherol in motor hypofunction with aging in alpha-tocopherol transfer protein knockout mice as assessed by oxidative stress biomarkers.   J Nutr Biochem, 21(1): 66-76.

It has been hypothesized that oxidative stress plays a key role in aging. In order to elucidate the role of the antioxidant network - including alpha-tocopherol (alphaT) and alphaT transfer protein - in aging in vivo, alpha-tocopherol transfer protein knockout (alphaTTP(-/-)) mice were fed a vitamin-E-depleted diet, and wild-type (WT) mice were fed a diet containing 0.002 wt.% alphaT from the age of 3 months to 1 1/2 years. The lipid oxidation markers total hydroxyoctadecadienoic acid (tHODE) ... [Abstract] [Full-text]

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