Conversion of major soy isoflavone glucosides and aglycones in in vitro intestinal models. Issue 3 (18th November 2013)

• Record Type: Journal Article
• Authors: Islam, Mohammed A.; Punt, Ans; Spenkelink, Bert; Murk, Albertinka J.; Rolaf van Leeuwen, F. X.; Rietjens, Ivonne M. C. M.
• Is Part Of: Molecular nutrition & food research. Volume 58:Issue 3(2014:Mar.)
• Page Start: 503
• Page End: 515
• Publication Date: 2013-11-18
• Subjects: Food -- Biotechnology -- Periodicals; Food -- Microbiology -- Periodicals; Nutrition -- Periodicals; Food -- Toxicology -- Periodicals; Nutrition -- Periodicals; Food Microbiology -- Periodicals; Food Technology -- Periodicals; Molecular Biology -- Periodicals; 664.0705
• DOI: 10.1002/mnfr.201300390
• Languages: English
• ISSNs: 1613-4125

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="mnfr2105-sec-0010" sec-type="section"> <title>Scope</title> <p>This study compares conversion of three major soy isoflavone glucosides and their aglycones in a series of in vitro intestinal models.</p> </sec> <sec id="mnfr2105-sec-0020" sec-type="section"> <title>Methods and results</title> <p>In an in vitro human digestion model isoflavone glucosides were not deconjugated, whereas studies in a Caco‐2 transwell model confirmed that deconjugation is essential to facilitate transport across the intestinal barrier. Deconjugation was shown upon incubation of the isoflavone glucosides with rat as well as human intestinal S9. In incubations with rat intestinal S9 lactase phlorizin hydrolase, glucocerebrosidase, and cytosolic broad‐specific β‐glucosidase all contribute significantly to deconjugation, whereas in incubations with human intestinal S9 deconjugation appeared to occur mainly through the activity of broad‐specific β‐glucosidase. Species differences in glucuronidation and sulfation were limited and generally within an order of magnitude with 7‐<italic>O</italic>‐glucuronides being the major metabolites for all three isoflavone aglycones and the glucuronidation during first pass metabolism being more efficient in rats than in humans. Comparison of the catalytic efficiencies reveals that deconjugation is less efficient than conjugation confirming that aglycones are unlikely to enter the systemic circulation.</p> </sec> <sec id="mnfr2105-sec-0030" sec-type="section"> <title>Conclusion</title> <p>Altogether, the data point at possible differences in the characteristics for intestinal conversion of the major soy isoflavones between rat and human, especially with respect to their deconjugation.</p> </sec> </abstract>