- 作者: Ching Kuang Chow
- 作者服務機構: Graduate Center for Nutrition Sciences and Kentucky Agricultural Experiment Station, University of Kentucky, Lexington, Ky., USA
- 中文摘要: --
- 英文摘要: Information accumulated lately has confirmed the essen-tiality of vitamin E for humans and provided a betterunderstanding of its biological function and metabolicfate. The discovery of α-tocopherol transfer protein,which preferentially binds to RRR-α-tocopherol, not onlyprovides conclusive evidence of the essentiality of vita-min E for humans, but also sheds light on the superiorityof RRR-α-tocopherol biologically over other isomers. Thepresence of tocopherol regeneration systems and multi-pie interdependent antioxidant systems is largely re-sponsible for the lack of a widespread deficiency inhumans and the difficulty to deplete vitamin E in theadult. The bulk of excess tocopherols consumed is ex-creted to feces unchanged or to urine with the side chainshortened but the chroman ring intact. The ability ofdietary vitamin E to mediate mitochondrial superoxidegeneration affords a possible mode of action of vitamin Eat the tissue levels. By decreasing the generation and/orthe levels of reactive oxygen/nitrogen species, dietaryvitamin E not only protects against oxidative damage,but also modulates the expression and/or activation ofredox-sensitive biological response modifiers that regu-late important cellular events.
- 中文關鍵字: --
- 英文關鍵字: --