Sustainable Biofuels and Coproducts Research Unit, Eastern Regional Research Center, United States Department of Agriculture, Agricultural Research Service, 600 East Mermaid Lane, Wyndmoor, PA 18951, USA.
Institute of Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 9, 8092 Zurich, Switzerland.
Prog Lipid Res. 2018 Apr;70:35-61. doi: 10.1016/j.plipres.2018.04.001. Epub 2018 Apr 5.
Phytosterols (plant sterols) occur in the cells of all plants. They are important structural components that stabilize the biological membranes of plants. Sterols can occur in the "free" unbound form or they can be covalently bound via an ester or glycosidic bond. Since our previous 2002 review on phytosterols and phytosterol conjugates, phytosterol glucosides have been found to be important structural components in the lipid rafts of the plasma membrane of plant cells, where they are thought to be essential to the function of plasma membrane enzymes and perhaps other proteins. Phytosterols also serve as precursors in the synthesis of important bioactive compounds such as steroidal saponins, steroidal glycoalkaloids, phytoecdysteroids, and brassinosteroids. Methods for the analysis of phytosterols range from traditional gas chromatography of free phytosterols to modern sophisticated forms of mass spectrometry which have been used for the new field of sterol lipidomics, sometimes called "sterolomics." Phytosterol-enriched functional foods first appeared about twenty years ago and many clinical studies have confirmed the low density lipoprotein (LDL) cholesterol-lowering properties of various types of phytosterols. In recent years additional clinical studies and more than ten important meta-analyses have provided insights to better understand the cholesterol-lowering and other biological effects of plant sterols.
植物固醇（甾醇）存在于所有植物细胞中。它们是稳定植物生物膜的重要结构成分。甾醇可以以“游离”的未结合形式存在，也可以通过酯或糖苷键共价结合。自从我们在 2002 年对植物固醇和植物固醇共轭物进行了综述以来，人们发现植物固醇葡萄糖苷是植物细胞质膜脂筏的重要结构成分，它们被认为对质膜酶的功能以及其他蛋白质的功能是必不可少的。植物固醇还可以作为生物活性化合物如甾体皂苷、甾体糖苷生物碱、植物蜕皮激素和油菜素内酯的合成前体。植物固醇的分析方法从游离植物固醇的传统气相色谱法到现代复杂形式的质谱法，这些方法已被用于固醇脂质组学这一新领域，有时也称为“固醇组学”。富含植物固醇的功能性食品大约在二十年前首次出现，许多临床研究证实了各种类型的植物固醇降低低密度脂蛋白（LDL）胆固醇的特性。近年来，更多的临床研究和十多项重要的荟萃分析提供了更深入的了解，有助于更好地理解植物固醇的降胆固醇和其他生物学作用。
