Intestinal Epithelial Monolayer Permeability of Sweet Potato-Derived Anthocyanin and Carotenoid Extracts in Caco-2 Cells

Abstract

Caco-2 human intestinal epithelial cells were used to determine the intestinal epithelial monolayer membrane permeability of the anthocyanin and carotenoid extracts from the purple-and yellow-flashed sweet potatoes, respectively. The permeability was analyzed at concentrations of 10 mg/mL of anthocyanin extract and 0.5 mg/mL of carotenoid extract without cellular toxicity. The Caco-2 cells were incubated for 25 days to form a monolayer on the Transwell filter. It was ensured that the membrane integrity of the monolayer was suitable for measuring the permeability in vitro by treatment with lucifer yellow and comparison with two markers, atenolol and propranolol. The permeability of lucifer yellow was 0.53% and the apparent permeability coefficients (Papp) of atenolol and propranolol were 6.01×10 -7 and 2.26×10 -5 cm/s, respectively, indicating that the monolayer was successfully formed. The Papp of the anthocyanin extract was 0. 31×10 -6 , 1.57×10 -6, 4.69×10 -6, and 5.16×10 -6 cm/s for 1, 2, 4, and 6 hours, respectively. Analysis of the permeation rate on each of the twelve anthocyanins, 7 peonidins and 5 cyanidins in the extract showed that peonidins and cyanidins possessing caffeic acid present a higher permeability than those with ferulic acid or benzoic acid. However, cryptoxanthin, 13Z-β-carotene, all-trans-β-carotene, and 9Z-β-carotene in the carotenoid extract were not detectable within 6 hours of the incubation time.

Preparation of Hypoallergenic Whey Protein Hydrolysate by a Mixture of Alcalase and Prozyme and Evaluation of Its Digestibility and Immunoregulatory Properties

“…The buffer on the receiver plate was recovered over time (20, 40, 60, and 120 min). After analyzing the protein content of the sample initially distributed in the insert and the sample collected over time using the bicinchoninic acid assay, the permeability of the sample was analyzed using the following formula (Park et al, 2021): Permeability (%) = [Total protein (mg) in the receiver plate]/[Initial protein (mg) added to the insert] × 100.…”