Phospholipids affect the intestinal absorption of carotenoids in mice

Previously, we have shown that uptake of carotenoids solubilized with mixed micelles by human intestinal Caco-2 cells is enhanced by lysophosphatidylcholine (lysoPC) and suppressed by PC. This study determined the effect of PC and lysoPC in mixed micelles on the accumulation of beta-carotene and lutein in mice in order to elucidate the roles of micellar phospholipid in the intestinal uptake of carotenoids in vivo. Mixed micelles were composed of 2.5 mM monooleoylglycerol, 7.5 mM oleic acid, 12 mM sodium taurocholate, 200 microM carotenoid, and 3 mM phospholipid in PBS. The mice were fed single doses of beta-carotene or lutein solubilized in PC (PC group), lysoPC (LPC group), and no phospholipid (NoPL group) micelles. The beta-carotene responses in the plasma and liver of the PC group were markedly lower than those of the other two groups, whereas no differences were noticed between the LPC and NoPL groups. The average level of lutein in the plasma of the PC group after administration was significantly (P < 0.05) lower than those of the other groups. Moreover, the average level of lutein in the liver was significantly (P < 0.05) different among the groups in the order of LPC > NoPL > PC. Thus, the results clearly indicate that PC suppressed the accumulation of beta-carotene and lutein in plasma and liver and that lysoPC enhanced the accumulation of lutein in liver. These results suggest that the hydrolysis of PC to lysoPC plays an important role in the intestinal uptake of carotenoids solubilized in mixed micelles.