absorption and metabolism of xanthophylls叶黄素的吸收和代谢.pdfVIP

Mar. Drugs 2011, 9, 1024-1037; doi:10.3390/md9061024 OPEN ACCESS Marine Drugs ISSN 1660-3397 /journal/marinedrugs Review Absorption and Metabolism of Xanthophylls Eiichi Kotake-Nara and Akihiko Nagao * National Food Research Institute, National Agriculture and Food Research Organization, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, Japan; E-Mail: ekotake@affrc.go.jp * Author to whom correspondence should be addressed; E-Mail: nagao@affrc.go.jp; Tel.: +81-29-838-8039; Fax: +81-29-838-7996. Received: 1 April 2011; in revised form: 3 June 2011 / Accepted: 7 June 2011 / Published: 10 June 2011 Abstract: Dietary carotenoids, especially xanthophylls, have attracted significant attention because of their characteristic biological activities, including anti-allergic, anti-cancer, and anti-obese actions. Although no less than forty carotenoids are ingested under usual dietary habits, only six carotenoids and their metabolites have been found in human tissues, suggesting selectivity in the intestinal absorption of carotenoids. Recently, facilitated diffusion in addition to simple diffusion has been reported to mediate the intestinal absorption of carotenoids in mammals. The selective absorption of carotenoids may be caused by uptake to the intestinal epithelia by the facilitated diffusion and an unknown excretion to intestinal lumen. It is well known that β-carotene can be metabolized to vitamin A after intestinal absorption of carotenoids,