胶束化对Caco-2上皮细胞叶黄素吸收和转运的影响

本试验为研究胶束化促进叶黄素肠上皮细胞转运的特性,采用体外消化模型探究胶束化处理对叶黄素生物利用度的影响以及Caco-2细胞模型测定胶束化对叶黄素肠细胞摄取、表观渗透系数和细胞内吞的影响。结果显示:随浓度升高胶束化叶黄素生物可给率先增大后减小,浓度为6×10-5 mol/L时胶束化叶黄素的生物可给率最高,是叶黄素单体的1.42倍;叶黄素胶束化显著促进了其细胞吸收量,细胞内积累量是单体的2.6倍。表观渗透系数(P_app)测定表明胶束化叶黄素累积转运分数大于1.5%,且被动扩散为其跨膜输送主要途径;胶束化后,P_app(B→A)与P_app(A→B)比值明显降低。进一步通过细胞内吞抑制实验发现制霉菌素(Nystain)、3-羟基-2-萘甲酸(3,4-二羟基苯基)亚甲基]酰肼(Dynasore)均能抑制胶束化叶黄素的转运(P<0.05),而5-(N-乙基-N-异丙基)阿米洛利(EIPA)无显著抑制作用(P>0.05)。以上研究结果表明,胶束化处理显著促进了叶黄素的生物利用度,其在肠细胞中的跨膜吸收途径以被动扩散为主,兼具网格蛋白介导和小窝/脂筏蛋白介导的细胞内吞途径。

Effect of Micellization on Lutein Absorption and Transportation in Caco-2 Epithelial Cells

This study aims to investigate the characteristics of micellarization to promote the transport of lutein in intestinal epithelial cells. We used in vitro digestion to investigate the effects of micellar treatment on lutein bioaccessibility and Caco-2 cell models to explore the effects of micellarization on cellular uptake,apparent permeability coefficients(P_app)and endocytic pathway of lutein. The results showed that the bioaccessibility of micellar lutein increased first and then decreased with the increase of concentration. The bioaccessibility of lutein micelle was the highest when the concentration was 6×10-5 mol/L,which was 1.42 times that of lutein monomer. Meanwhile,the cell uptake of lutein was significantly improved after micellization,which was 2.6 times that of lutein monomer. The P_app determination showed that the cumulative transport fraction of lutein micelle was greater than 1.5%,and passive diffusion was the main transmembrane transport pathway. Meanwhile,the ratio of P_app(B→A)and P_app(A→B)was significantly lower after micellization. Further,the endocytosis inhibition experiment showed that the migration of micellar lutein was significantly inhibited by Nystain and Dynasore inhibitors(P<0.05),while EIPA had no significant inhibitory effect(P>0.05). Therefore,this study demonstrates that micellization significantly improves the bioavailability of lutein,and its transmembrane absorption pathway in intestinal cells was mainly passive diffusion,as well as clathrin-mediated endocytosis,caveolin/lipoprotein-mediated endocytosis.