Cell-Based Assay To Quantify the Antioxidant Effect of Food-Derived Carotenoids Enriched in Postprandial Human Chylomicrons

Abstract

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 β-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.

Detection of Key Factors Affecting Lycopene in Vitro Accessibility

“…Second, during intestinal digestion, carotenoids must be solubilized into micelles, a phenomenon favored by the intestinal pH, the carotenoids’ hydrophobicity, the amount of bile salts secreted during digestion, and the presence of oil or fat in a carotenoid-rich diet. − After solubilization into micelles, they are taken up into enterocytes by passive diffusion or by active transport associated with a lack of membrane transport proteins, such as SR-BI, NPC1L1, ABCA1, and CD36, and then are packaged into triacylglycerol-rich chylomicrons and secreted into the lymph for delivery to the bloodstream, where they are rapidly degraded by lipoprotein lipase . The resulting chylomicrons remnants are rapidly taken up by the liver, which secretes lycopene and other carotenoids associated with hepatic lipoprotein. ,, However, the absorption efficiency of lycopene is variable, since many factors affect uptake in the enterocyte, and in the population there are low and high lycopene absorbers.…”

“…18 The resulting chylomicrons remnants are rapidly taken up by the liver, which secretes lycopene and other carotenoids associated with hepatic lipoprotein. 11,18,19 However, the absorption efficiency of lycopene is variable, since many factors affect uptake in the enterocyte, and in the population there are low and high lycopene absorbers.…”