Promoting effect of micellization on lutein absorption and evaluation of its mechanism using a Caco-2 cell model

Abstract

Abstract Background: Micellization can significantly promote the absorption of lutein. However, the mechanism is still unknown. Methods and Results: This study investigated the effect of micellar treatment on lutein absorption and transmembrane transport mechanism by in vitro digestion and the Caco-2 cell model. The results showed that the bioaccessibility of micellized lutein was 1.42 times that of lutein. The Apparent Permeability Coefficients (Papp) indicated that the main transmembrane pathway was found as passive transport. While solubility is regarded as a restrictive factor for lutein absorption. Further, nystatin and dynasore dramatically decreased the absorption of lutein micelle. In addition, micellization treatment increased cluster determinant 36 (CD36) expression (p<0.05). And lutein micelle treatments significantly lower SCARB1, SREBF, and ABCA1 mRNA expression and increased the CD36 mRNA expression (p<0.05). Conclusions: This study demonstrated that micellization significantly improved the absorption of lutein. The transmembrane absorption pathway in intestinal cells was mainly passive transport, as well as clathrin-mediated and caveolin/lipoprotein-mediated endocytosis.