Chronic flavan‐3‐ol exposure induces changes in metabolism and transport kinetics in differentiated Caco‐2 cell monolayers (270.1)

Abstract

A limiting factor in the application of flavan‐3‐ols for chronic disease prevention is their low oral bioavailability. However, evidence suggests that chronic dosing paradigms can significantly increase their bioavailability. To explore fundamental alterations occurring from chronic gut exposure to flavan‐3‐ols, Caco‐2 monolayers were cultured and differentiated in 6‐well plates in addition to Transwell® inserts for 12 and 21 days, respectively. Culture media contained 0, 1, or 10 μM concentrations of epigallocatechin gallate (EGCG) or epicatechin (EC). Following differentiation, cellular uptake and transport of flavan‐3‐ols was assessed from 0‐6 h following a final 50 μM acute treatment of respective pretreated compound. Transport of flavan‐3‐ols, along with metabolism to methylated and sulfonated metabolites, was assessed by LC‐TOF‐MS. After 90 min, 1 μM EGCG pretreated monolayers showed significantly (P < 0.05) greater accumulation compared to control (mean ± SEM; 310. ± 12.4 vs. 208 ± 12.1 pmol EGCG/mg protein). 1 μM EC pretreatment showed similar significant (P < 0.05) results (477 ± 65.9 vs. 150. ± 35.0 pmol EC/mg protein). Further, Papp calculated from Transwell® experiments for 10 μM pretreated cell monolayer were 7.93 x 10‐7 cm/s compared to 5.09 x 10‐7 cm/s for control. These results suggest that intestinal transport and metabolism of flavan‐3‐ols is modulated by chronic exposure.Grant Funding Source: Supported by National Science Foundation Graduate Research Fellowship Program Grant No. DGE‐1333468.