Article

Traber MG. Vitamin E regulatory mechanisms

Department of Nutrition and Exercise Science, Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA.
Annual Review of Nutrition (Impact Factor: 10.46). 02/2007; 27:347-62. DOI: 10.1146/annurev.nutr.27.061406.093819
Source: PubMed

ABSTRACT Dietary and supplemental vitamin E is absorbed and delivered to the liver, but of the various antioxidants with vitamin E activity, only alpha-tocopherol is preferentially recognized by the alpha-tocopherol transfer protein (alpha-TTP) and is transferred to plasma, while the other vitamin E forms (e.g., gamma-tocopherol or tocotrienols) are removed from the circulation. Hepatic alpha-TTP is required to maintain plasma and tissue alpha-tocopherol concentrations. The liver is the master regulator of the body's vitamin E levels in that it not only controls alpha-tocopherol concentrations, but also appears to be the major site of vitamin E metabolism and excretion. Vitamin Es are metabolized similarly to xenobiotics; they are initially omega-oxidized by cytochrome P450s, undergo several rounds of beta-oxidation, and then are conjugated and excreted. As a result of these various mechanisms, liver alpha-tocopherol and other vitamin E concentrations are closely regulated; thus, any potential adverse vitamin E effects are limited.

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    • "Vit E are classified into tocopherols and tocotrienols present in forms such as α-, β-, γ-and δtocopherols (α-, β-, γ -and δ-T) and α-, β-, γ-and δtocotrienols (α-, β-, γ-and δ-TT). Both tocopherols and tocotrienols have methyl groups on the chromanol ring (for α-, β-, γ-and δ-form); however, tocotrienols contain unsaturated 16-carbon side chain with double bonds at the positions of 3ʹ,7ʹ, and 11ʹ (Fig 1) [33]. "
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    ABSTRACT: Vitamin E (Vit E) has enormous potential for cancer growth inhibition and cancer prevention. It has been studied widely for its antioxidant, anti-inflammatory and anti-cancerous activity. The aim of this review is to provide a summary of the research so far in regards to Vit E and its role in the prevention of human esophageal squamous cell cancer (ESCC), which is among the most malignant types of cancers. Its prevalence is high in China and poses a serious threat to the health of the residents. Therefore, finding new strategies to prevent and lessen the risk of ESCC and comprehensive understanding of carcinogenesis is essential. This review will provide the brief guidelines in understanding of Vit E in the prevention of ESCC. The data suggest that the combination of tocopherols like γ-tocopherol-rich mixture of tocopherols (γ-TmT) would be highly effective to use in the future for the prevention of cancers.
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    • "Measurement of acetylcholinesterase (AchE) is broadly used like present study as biomarker of pollution, AchE activity was monitored in the clam Tapes philippinarum in the Lagoon of Venice (Italy) by[7] with no particular correlation between Ache activity and Condition Index(CI) was found and marked differences in AchE activity were showed when comparing enzyme activity of clams from various sites in the Lagoon of Venice with those of clams collected. Significant reductions in AchE activity were observed in animals collected in both nearby canals and licensed areas, indicating the homogeneous spatial distribution of potentially neurotoxic compounds throughout the Lagoon, On the other hand, Vitamin E is a fat soluble vitamin and its main role is a nonenzymatic antioxidant, it protects body cells from toxic compounds such as heavy metals [8]. "
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    ABSTRACT: Biochemical markers (Total protein, Vitamin C, Vitamin E, Acetylcholinesterase, and Metallothioneins) induced by acute exposure of Zn&pb in Snail (Viviparus bengalensis) to show their response against these metals. These makers in snail sp. showed different significance response according to Zn acute exposure. So increased and decreased as reaction against acute exposure, The same trend adapted from biomarkers after pb acute exposure in snail sp. while the different response was appeared from these biomarkers after interaction acute exposure.
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    • "Measurement of acetylcholinesterase (AchE) is broadly used like present study as biomarker of pollution, AchE activity was monitored in the clam Tapes philippinarum in the Lagoon of Venice (Italy) by[7] with no particular correlation between Ache activity and Condition Index(CI) was found and marked differences in AchE activity were showed when comparing enzyme activity of clams from various sites in the Lagoon of Venice with those of clams collected. Significant reductions in AchE activity were observed in animals collected in both nearby canals and licensed areas, indicating the homogeneous spatial distribution of potentially neurotoxic compounds throughout the Lagoon, On the other hand, Vitamin E is a fat soluble vitamin and its main role is a nonenzymatic antioxidant, it protects body cells from toxic compounds such as heavy metals [8]. "
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