Author
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FAILLA, MARK - OHIO STATE UNIV., OH |
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CHITCHUMROONCHOKCHAI, CHUREEPORN - OHIO STATE UNIV., OH |
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Ishida, Betty |
Submitted to: Journal of Nutrition
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 12/10/2007 Publication Date: 2/20/2008 Citation: Failla, M.L., Chitchumroonchokchai, C., Ishida, B.K. 2008. In Vitro Micellarization and Intestinal Cell Uptake of cis Isomers of Lycopene Exceed Those of All-trans Lycopene. Journal of Nutrition. 138:482-486. Interpretive Summary: The ratio of cis to all-trans lycopene (LYC) in human and animal tissues is higher than in foods. We don’t know the reason for this difference, but their stability, transport, and metabolism might differ. Here we compared stability during digestion, efficiency of forming micells (tiny fat droplets), and uptake of cis and all-trans isomers of LYC and carotenes and stability in cells, using an in vitro digestion and Caco-2 human intestinal cell model. Aril and oil from carotenoid-rich gac fruit were cooked with rice to provide a natural source for LYC and carotenes [mostly beta-carotene (ßC)]. The ratio of cis to trans isomers of LYC and ßC was similar before and after simulated gastric and small intestinal digestion with recovery of total carotenoids greater than 70%. More micells of cis-LYC isomers were formed during digestion of meals with both gac aril and oil than the all-trans isomer, but less than with carotenes. Uptake of cis-LYC isomers and carotenes by Caco-2 cells were similar and much greater than all-trans LYC. Carotenoids in micells were relatively stable in cell culture and after being taken up into Caco-2 cells. Our data suggest that the greater bioaccessibility of cis compared to all-trans isomers of LYC explains some of the increase in the cis isomers in tissues and that gac fruit is an excellent source of bioaccessible LYC and vitamin A-forming carotenoids. Technical Abstract: The ratio of cis and all-trans lycopene (LYC) in human and animal tissues exeeds that in foods. The basis for this difference remains unknown, although differences in their stability, transport, and metabolism have been suggested. Here we systematically compared the digestive stability, efficiency of micellarization, and uptake and intracellular stability of cis and all-trans isomers of LYC and carotenes using the coupled in vitro digestion and Caco-2 human intestinal cell model. Aril and oil from the carotenoid-rich gac fruit were cooked with rice to provide a natural source for LYC and carotenes. The ratio of cis to trans isomers of LYC and beta-carotene (BC) was similar before and after simulated gastric and small intestinal digestion with recovery ot total carotenoids exceeding 70%. Micellarization of cis isomers of LYC during digestion of meals with both gac aril and oil was significantly greater than that of the all trans isomer, but less than for the carotenes. Uptake of cis isomers of LYC by Caco-2 cells was similar to that of carotenes and significantly greater than all-trans LYC. Micellarized carotenoids were relatively stable in micelles incubated in the cell culture environment and after accumulation in Caco-2 cells. These data suggest that the greater bioaccessibility of cis compared to all-trans isomers of LYC contributes to the enrichment of the cis isomers in tissues and that gac fruit is an excellent source of bioaccessible LYC and provitamin A carotenoids. |