Centre de coopération internationale en recherche agronomique pour le développement
, Caporiccio Bertrand3
, Amiot Marie-Josèphe4
1CIRAD-UMR Qualisud, 34398 Montpellier, France
2Université catholique de Louvain, Institut des Sciences de la Vie, BCNT, Belgique 3Université Montpellier II UMR Nutripass, 34095 Montpellier, France
4UMR 476 INSERM/1260 INRA, Université de la Méditerranée,
Faculté de Médecine de la Timone, 13385 Marseille, France*
Corresponding author: firstname.lastname@example.org HE
health benefit of a diet rich in fruits and vegetables
could be attributed to the presence of a large diversity
of phytochemicals within this food group. Because
citrus juices are a rich source of antioxidants including
ascorbic acid, phenolics compounds, and carotenoids, the
bioavailability of these molecules could be modulated by the
interactions between micronutrients. Our study, focused on
effects of flavonoids and acid ascorbic on intestinal carotenoid uptake.
aterials and Method
Carotenoid uptake from synthetic micelles was assessed using differentiated
Caco-2 TC-7 cell monolayers, cultured on 75 cm2 flask or on transwells Synthetic mixed were
incubated with solutions of flavonoids (250 µM), acid ascorbic (50 µM) or iron and chelator (500 and 250 µM). Analysis of carotenoids from micelles and cells (i.e. the sum of carotenoids recovered in the scraped cells and in the basolateral chamber) were carried out by HPLC according previous work (1).
esults and discussion
❚❚❚ Data illustrated on figure 1 showed an enhancing effect of hesperetin (HES) and hesperidin (HES-G) on the uptake of β-cryptoxanthin (b-CX) and β-carotene (b-C). At 5h or 24h incubation with a mixture b-C + b-CX, HES-G and HES significantly increased total carotenoid uptake by 1.7, 1.6-fold, respectively. Interestingly, acid ascorbic (AA) was able to abolish the enhancing effect of HES-G by decreasing significantly the cellular uptake of carotenoids from 48.2 to 39% after 5h incubation (p < 0.05) (figure 2).
R e f e r e n c e
, the present data suggest that the citrus polyphenols could act through their
iron-chelating properties. This hypothesis was conforted by the last experimentation
demonstrating the role of iron and iron chelator on carotenoid uptake. However, further
investigations are needed to specify the mechanism responsible of this interaction
0 200 400 600 800 1000 1200 1400 1600 b-C + b-CX b-C + b-CX + HE S b-C + b-CX + HE S -G b-C + b-CX in cell s (pmol/m g o f p ro tein s) 0 200 400 600 800 1000 1200 1400 b -C b -C X b -C + HE S b -C X + HE S b-C o r b-CX in cell s (pmol/m g o f p ro tein s) a a a b b b c 0 1 0 2 0 3 0 4 0 5 0 6 0 C H E S -G A A H E S -G + A A % b-C+b-CX in cell s +Ba sola te ral me d ium * *
❚❚❚ In order to attribute the enhancing effect of HES-G to its already known iron-chelating effect, another experiment was conducted by incubating cells with b-CX in presence of either iron (Fe) or a metal chelator: deferoxamine (DFO). After 5h incubation, b-CX uptake decrease in presence of
iron from 926 to 677 picomol/mg de protein and increase in presence of chelator from 926 to 1548 picomol/mg de protein (figure 3).
Figure 2. Effect of ascorbic acid (AA) on carotenoid (b-C plus b-CX) uptake by Caco-2 cells grown on inserts with and without
addition of HES-G. Data are expressed as % of b-CX and b-CX recovered in cells and basolateral medium after incubation .
Values are expressed as mean ± SD, n = 6. * indicates a statistical significant difference.
Figure 1. Effect of HES and HES-G on cellular carotenoid uptake by Caco-2 cells grown in
T-75 flasks. A) Effect of HES on individual carotenoid uptake (b-C and b-CX). B) Effect of HES, HES-G
on carotenoid uptake (b-C plus b-CX). Values are expressed as mean ± SD of tree determinations.
Data with different letters display significant statistical differences
(p < 0.05). 0 200 400 600 800 1000 1200 1400 1600 1800 C HE S -G DF O F e picomol/m g p ro tein a b c d
Figure 3. Effect of HES-G, DFO and Ferric sulfate on b-CX cellular uptake by Caco-2 cells growing in inserts after 5 h incubation. Values (picomol/mg of protein) are expressed as mean ± SD of tree determinations. Data with
different letters display significant statistical differences (p < 0.05).
1. DHUIQUE-MAYER C., BOREL P., REBOUL E.,
CAPORICCIO B., BESANCON P. & AMIOT M. J.
(2007). Beta-Cryptoxanthin from Citrus juices: assessment of bioaccessibility using an in vitro digestion/Caco-2 cell culture model.
British Journal of Nutrition, 97, 883-890.
uptake by intestinal Caco-2 cells
Citrus flavanone enhance carotenoids
HES-G H Fe Fe HES G Fe Fe HES-G + Fe3+ BCO Hypothesis APICAL BASAL Enterocyte Vit C + Fe3+ Fe 2+ CAR CAR CAR CAR CAR CAR CAR T
Figure 4. Hypothetic mechanism of carotenoid uptake by enterocyte in presence of hesperidin. (CAR: carotenoids,
BCO: β-carotene 15, 15’ dioxygenase)
ICPH 2009— 4th International Conference on Polyphenols and Health — Yorkshire, England: 7-11 th December 2009
❚❚ The results indicate that citrus flavanones enhance the carotenoid uptake by intestinal cells and that addition of ascorbic acid counteract this effect. We supposed that HES-G has a chelating
function and in contrast AA releases Fe in the media. These results suggest that carotenoid uptake could be mediated by flavonoids and AA in relation with iron and support the following hypothesis. By
chelating iron from media the flavanones could possibly inhibit the enzyme responsible for
β-carotene cleavage (BCO) knowing that this enzyme activity is iron dependent (figure 4). The enhancing effect of HES-G was not observed on non-provitamin A carotenoid.
uptake by intestinal Caco-2 cells
O O O O OH O HO O OH OH HO OH OH OH OCH3 7 5 3' 4' Hesperidin β−cryptoxanthin HO
Design and production: CIRAD