Comparison of the inhibitory effects of procyanidins with different structures and their digestion products against acrylamide-induced cytotoxicity in IPEC-J2 cells

This study evaluated the stabilities of catechin (C), epicatechin (EC), procyanidin B3, procyanidin A1 and epicatechin-(4β → 6)-epicatechin-(2β → O → 7,4β → 8)-catechin (PCA-trimer) during in vitro digestion, as well as characterized their digestion products (DPs), and evaluated their protective effects against ACR-induced cytotoxicity on IPEC-J2 cells. The results showed that procyanidin A1 (70.38%) and procyanidin B3 (15.25%) had the highest and lowest stability in the gastric phase, respectively. During the intestinal phase, the contents of C, EC and procyanidin B3 increased from 57.37%, 49.92% and 15.25% to 88.15%, 71.81% and 46.72%, while those of procyanidin A1 and PCA-trimer showed continuous decreases to 27.13% and 28.89%, respectively. Isomerism, hydrolysis and condensation reactions were found to play major roles in in vitro digestion. Besides, procyanidin A1 and its DPs exhibited the best protective effect against ACR-induced cytotoxicity compared with other compounds and their DPs, as indicated by MTT assay and measurement of glutathione (GSH).