Duncan Kimbell R, Suzuki Yuichiro J
Department of Pharmacology and Physiology, Georgetown University Medical Center, 3900 Reservoir Road NW, Washington, DC 20057, USA.
Antioxidants (Basel). 2017 Mar 13;6(1):20. doi: 10.3390/antiox6010020.
Vitamin E refers to a family of compounds that function as lipid-soluble antioxidants capable of preventing lipid peroxidation. Naturally occurring forms of vitamin E include tocopherols and tocotrienols. Vitamin E in dietary supplements and fortified foods is often an esterified form of α-tocopherol, the most common esters being acetate and succinate. The vitamin E esters are hydrolyzed and converted into free α-tocopherol prior to absorption in the intestinal tract. Because its functions are relevant to many chronic diseases, vitamin E has been extensively studied in respect to a variety of diseases as well as cosmetic applications. The forms of vitamin E most studied are natural α-tocopherol and the esters α-tocopheryl acetate and α-tocopheryl succinate. A small number of studies include or focus on another ester form, α-tocopheryl nicotinate, an ester of vitamin E and niacin. Some of these studies raise the possibility of differences in metabolism and in efficacy between vitamin E nicotinate and other forms of vitamin E. Recently, through metabolomics studies, we identified that α-tocopheryl nicotinate occurs endogenously in the heart and that its level is dramatically decreased in heart failure, indicating the possible biological importance of this vitamin E ester. Since knowledge about vitamin E nicotinate is not readily available in the literature, the purpose of this review is to summarize and evaluate published reports, specifically with respect to α-tocopheryl nicotinate with an emphasis on the differences from natural α-tocopherol or α-tocopheryl acetate.
维生素E是指一类化合物，它们作为脂溶性抗氧化剂发挥作用，能够防止脂质过氧化。天然存在的维生素E形式包括生育酚和生育三烯酚。膳食补充剂和强化食品中的维生素E通常是α-生育酚的酯化形式，最常见的酯是乙酸酯和琥珀酸酯。维生素E酯在肠道吸收前会被水解并转化为游离的α-生育酚。由于其功能与许多慢性疾病相关，维生素E已针对多种疾病以及化妆品应用进行了广泛研究。研究最多的维生素E形式是天然α-生育酚以及α-生育酚乙酸酯和α-生育酚琥珀酸酯。少数研究包括或聚焦于另一种酯形式，即维生素E烟酸酯，它是维生素E与烟酸的酯。这些研究中的一些提出了维生素E烟酸酯与其他形式的维生素E在代谢和功效方面存在差异的可能性。最近，通过代谢组学研究，我们发现α-生育酚烟酸酯在心脏中内源性存在，并且其水平在心力衰竭时显著降低，这表明这种维生素E酯可能具有生物学重要性。由于关于维生素E烟酸酯的知识在文献中并不容易获取，本综述的目的是总结和评估已发表的报告，特别是关于α-生育酚烟酸酯的报告，重点是与天然α-生育酚或α-生育酚乙酸酯的差异。
