Objectives: Carotenoids are natural pigments that give yellow, orange, and red colors to vegetables and fruits such as tomatoes, carrots, and paprika. Carotenoids such as lycopene, β-carotene, and lutein have strong antioxidant activity, and consumption of tomatoes and tomato products is known to reduce the risk of cancer by inhibiting the growth, metastasis, and invasion of cancer cells such as prostate, breast, and colon cancer. The purpose of this study was to measure the digestion, absorption, or bioavailability of carotenoids in the body by using an in vitro digestion model.
Methods: We determined carotenoids in tomato using an in vitro gastric and intestinal digestion model. The range of carotenoids in fresh and in in vitro gastric and intestinal digesta of tomato were characterized and quantified using high performance liquid chromatography.
Results: In fresh tomato, lycopene was the predominant carotenoid, which also correlates with previously reported data. In addition, we found that fresh tomato contains a high amount of lutein, α-carotene, and β-carotene. After gastric and intestinal digestion, the levels of all carotenoids decreased. The intestinal digesta at 120 min added to the Caco-2 human intestinal cells, contained lutein, lycopene, α-carotene, and β-carotene. After 6 h, the percentage of carotenoids in the apical compartment varied between 31.44 and 39.21%, whereas 9.85~18.40% of the carotenoids were transported into the basolateral compartment and 4.55~9.78% were retained in the cells in the Caco-2 monolayer. The percentage of total cellular uptake in the intestinal digesta ranged from 14.39% (α-carotene) to 23.91% (lutein).
Conclusions: These results indicate that there is a difference between the amounts of carotenoids ingested and the amount actual transported into cells. In addition, since the bioavailability of carotenoids is not high, it is necessary to try various methods to maximize the bioavailability of carotenoid-containing foods.
Funding Sources: This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF-2021R 1F1A1060605).
