Effect of the consumption of a fruit and vegetable soup with high in vitro carotenoid bioaccessibility on serum carotenoid concentrations and markers of oxidative stress in young men.

AIM: To evaluate the effect of the daily intake of a fruit & vegetable soup with high in vitro bioaccessibility of carotenoids on ß-carotene and lycopene serum concentrations. METHODS: Fourteen healthy young men (24 ± 1 years) received 300 mL/day of a carrot, tomato, and broccoli soup, containing 3.9 mg ß-carotene and 4 mg lycopene, for 4 weeks followed by a 4-week washout period. The serum carotenoid response and oxidative markers were analyzed after 3 and 4 weeks of soup consumption and after a 4-week washout. RESULTS: The in vitro bioaccessibility of ß-carotene and lycopene was 55 and 43%, respectively, in the soup. Serum ß-carotene concentrations were significantly higher than baseline (0.33 ± 0.05 µmol/L) after 3 weeks (0.69 ± 0.06 µmol/L) and 4 weeks (0.78 ± 0.10 µmol/L) of soup consumption (P < 0.001). Serum lycopene was also significantly higher compared with baseline levels (0.26 ± 0.08-0.56 ± 0.04 µmol/L and 0.60 ± 0.04 µmol/L, after 3 and 4 weeks, respectively) (P < 0.001). Although the highest concentration of both carotenoids was found after 4 weeks, the levels were not statistically different from the levels at 3 weeks. A 4-week washout significantly decreased serum carotenoid concentrations, although only ß-carotene returned to baseline. Glutathione peroxidase (GPx) increased significantly after soup supplementation compared with baseline, while superoxide dismutase was significantly lower only after 3 weeks. Glutathione reductase, lipid, protein, and DNA oxidative markers remained unchanged. CONCLUSIONS: The soup contributed to increasing the concentration of each carotenoid by more than 100% after 3 and 4 weeks of consumption, the maximum increase being observed after 4 weeks. Oxidative markers did not show any variation except for GPx. Serum lycopene half-life was longer than that of ß-carotene, which may be important for studies evaluating both carotenoids.

Cell-based assay to quantify the antioxidant effect of food-derived carotenoids enriched in postprandial human chylomicrons.

We developed a new method to evaluate the antioxidant effect of food products in a biological system. The antioxidant status of HepG2 cells was quantified after incubation with postprandial human chylomicrons after the intake of vegetable products. Three subjects consumed in a meal a vegetable soup containing 8.4 mg of ß-carotene and 9 mg of lycopene. After 5 h, the subjects consumed a second meal without carotenoids. Blood samples were collected at basal time and every hour for 9 h. Chylomicrons were isolated from serum samples and used for both carotenoid quantification and HepG2 stimulation. Carotenoid in chylomicrons followed an inter-individual and bimodal carotenoid response. We demonstrated the antioxidant effect of postprandial chylomicrons in HepG2 at the time of maximum carotenoid concentration of chylomicrons with respect to basal time. This cell-based assay seems to be a useful method to evaluate the antioxidant effect of fruit and vegetable products in a biological system.