Determination of Selenium Bioavailability from Wheat Mill Fractions in Rats by Using the Slope-Ratio Assay and a Modified Torula Yeast-Based Diet

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• 作者：Philip G. Reeves ; Brian R. Gregoire ; David F. Garvin ; Gary A. Hareland ; James E. Lindlauf ; LuAnn K. Johnson ; and ; John W. Finley
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2007
• 出版时间：January 24, 2007
• 年：2007
• 卷：55
• 期：2
• 页码：516 - 522
• 全文大小：214K
• 年卷期：v.55,no.2(January 24, 2007)
• ISSN：1520-5118

文摘

Selenium is an essential mineral micronutrient for animals, and significant evidence supports anassociation between supranutritional Se intake and a reduction in the incidence of some forms ofcancer. Thus, supplemental Se intake may provide an avenue for reducing cancer incidence. However,an important issue to consider is the form of Se that should be provided in such a supplement, becausethe bioavailability and bioactivity of Se can vary dramatically depending on the chemical form in whichit is delivered. Because wheat products are the largest source of Se in U.S. diets, the absorption ofSe was evaluated in different fractions of milled wheat that exhibits very high Se levels, owing to itsproduction on naturally Se-rich soils. An experiment was conducted to determine the bioavailabilityof Se from three milled fractions of high-Se wheat. The method used was the slope-ratio assay,which measures the ability of Se from the wheat fractions to regenerate Se-dependent enzymeactivities and tissue Se concentrations in Se-deficient rats. The responses generated from wheat Sewere compared to a standard response curve generated by feeding graded amounts of Se as sodiumselenite (Na₂SeO₃; NaSelenite) or selenomethionine (SeMet) in an AIN-93G-Torula yeast-based diet.Results showed that Se from wheat flour (~75% extraction) was nearly 100% available by a numberof measures including plasma, liver, kidney, and muscle Se concentrations and liver and erythrocyteSe-dependent enzyme activities when compared with similar measures in rats fed NaSelenite orSeMet. However, on the basis of similar criteria, Se from wheat shorts was only about 85% availableand that from wheat bran was about 60% available for absorption. These results indicate that high-Se wheat products, mainly those made from refined flour alone, might be particularly well suited foruse as dietary Se supplements.