Bioavailability of ß-cryptoxanthin is greater from pasteurized orange juice than from fresh oranges - a randomized cross-over study.

SCOPE: Orange fruits and products thereof represent important dietary sources of carotenoids, particularly ß-cryptoxanthin. Since previous studies reported a positive effect of vegetable processing on carotenoid absorption, our objective was to compare the bioavailability of ß-cryptoxanthin from either fresh navel oranges (Citrus sinensis L. Osbeck) or pasteurized orange juice. METHODS AND RESULTS: The study was designed as a randomized 2-way cross-over study. Twelve volunteers consumed two meals delivering 744 µg of ß-cryptoxanthin from either fresh navel oranges or pasteurized orange juice. Eight blood samples were collected over 9.5 h after test meal consumption and analyzed using HPLC-DAD. Additionally, carotenoid bioaccessibility was assessed after in vitro digestion of the same test foods. ß-cryptoxanthin bioavailability from pasteurized orange juice was 1.8-fold higher than from fresh oranges (P = 0.011). Similarly, mean absorption of the non-dose adjusted carotenoids lutein (P = 0.301), zeaxanthin (P = 0.216), and zeinoxanthin (P = 0.090) were slightly higher from orange juice, although not reaching statistical significance. The in vitro digestion revealed a 5.3-fold higher bioaccessibility of ß-cryptoxanthin from orange juice. Dietary fiber contents in the test foods were inversely associated with carotenoid bioavailability. CONCLUSION: Orange juice represents a more bioavailable source of ß-cryptoxanthin than fresh oranges.

Comparison of bioavailability between ß-cryptoxanthin and ß-carotene and tissue distribution in its intact form in rats.

The bioavailability of two intact carotenoids in several tissues of ß-cryptoxanthin- and ß-carotene-fed rats (20 mg/kg of diet) was investigated. Although metabolites of provitamin A are not included in our study, ß-cryptoxanthin was found at higher concentrations in majority of the tissues. The results show that the bioavailability of intact ß-cryptoxanthin seemed to be higher than that of ß-carotene.

ß-Cryptoxanthin uptake in THP-1 macrophages upregulates the CYP27A1 signaling pathway.

SCOPE: Mitochondrial sterol 27-hydroxylase (CYP27A1), a mediator of cholesterol homeostasis, is reported to exhibit antiatherogenic properties. Many studies suggested that all-trans retinoic acid can be used to treat atherosclerosis through retinoic acid receptor (RAR)-mediated upregulation of CYP27A1 expression. In this study, we hypothesized that ß-cryptoxanthin (ß-cry), as a natural ligand of RAR, might act as antiatherogenic agent by upregulating CYP27A1. METHODS AND RESULTS: We found that ß-cry treatment significantly upregulated genes involved in the uptake, transport, and metabolism of retinoids and the signaling pathway of CYP27A1 expression in THP-1 macrophages as detected by microarray analysis. Meanwhile, intracellular levels of ß-cry were correlated to the concentration and exposure time of the treatment. The expression of genes, involved in signaling pathway of CYP27A1, was dramatically decreased due to repressed activity of RAR. Higher level of 27-hydroxycholesterol was detected in ß-cry-treated macrophages by HPLC. Docking simulation showed that ß-cry could interact with cellular retinoic acid binding protein 2. These findings were further confirmed through microarray results. CONCLUSION: Our results provide strong evidence that ß-cry can be actively taken up by THP-1 macrophages and exhibits antiatherogenic effect on THP-1 macrophages by inducing CYP27A1 expression via RAR.