The Effect of Ferulic Acid-Grafted Chitosan (FA-g-CS) on the Transmembrane Transport of Anthocyanins by and .

This work aims to evaluate the effect of ferulic acid-grafted chitosan (FA-g-CS) on the interaction between anthocyanin (ANC) and / and their functions in ANC transmembrane transport using Caco-2 cells. The transmembrane transport experiments of ANC showed its low transport efficiency (Papp < 10 cm/s), whereas the phenomenon of a significantly rise in anthocyanins transport efficiency was observed with the incubation of FA-g-CS ( < 0.05). In order to investigate the mechanism of FA-g-CS improving ANC transmembrane transport, Caco-2 cells were transfected with small interfering RNA () specific for transporters and , and incubated with ANC, FA-g-CS, or their combination. Subsequently, Western blot analyses and immunofluorescence staining were carried out to monitor the intracellular and levels. These siRNA-transfected cells, incubated with compounds, indicate that and participated in the ANC transmembrane transport and that FA-g-CS, ANC, or their combination enhance / expression. In particular, Caco-2 cells incubated with both FA-g-CS and ANC show significantly increased or expression (>80%) compared with exclusively using FA-g-CS or ANC (<60%). Molecular docking results demonstrate that there is a good binding between FA-g-CS/ANC and or . These results highlight that FA-g-CS promotes the transmembrane transport of ANC by influencing the interaction between ANC and /; the interaction between FA-g-CS and ANC could be another key factor that improves the bioavailability of ANC.