An in vitro model to study the intestinal absorption of carotenoids
2005
During, A. | Harrison, E.H.
An in vitro cell culture model to assess the intestinal absorption of carotenoids is described. When supplemented with taurocholate and oleic acid, differentiated Caco-2 cells on membranes are able to produce chylomicrons. Under conditions mimicking the in vivo postprandial state, Caco-2 cells take up carotenoids and secrete them incorporated into chylomicrons; the extents of absorption of all-trans, 9-cis, 13-cis beta-carotene, alpha-carotene, lutein, lycopene were 11%, 2%, 3%, 10%, 7%, and 3%, respectively. Saturation of beta-carotene transport through Caco-2 cells occurred at concentrations (>15 micromolar) higher than "physiological" concentrations. Finally, retinol supplementation resulted in an 1.7-fold increase in beta-carotene transport. The data suggest that (1) the intestinal absorption of carotenoids is facilitated by the participation of a specific epithelial transporter and (2) retinol promotes beta-carotene incorporation into larger, retinyl ester-enriched chylomicrons. The present in vitro cell culture system is a relevant model to study the intestinal absorption of carotenoids at the molecular level.
显示更多 [+] 显示较少 [-]