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 (PC_A-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 PC_A-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).

本研究评估了儿茶素（C），表儿茶素（EC），原花青素B ₃，原花青素A ₁和表儿茶素-（4β→6）-表儿茶素-（2β→O→7,4β→8）-儿茶素（PC _{A -trimer}）期间体外消化，以及其特征在于它们的消化产物（DPS），并评价它们对上IPEC-J2细胞ACR诱导的细胞毒性的保护作用。结果表明，原花青素A ₁（70.38％）和原花青素B ₃（15.25％）在胃中分别具有最高和最低的稳定性。在肠道阶段，C，EC和原花青素B ₃的含量分别从57.37％，49.92％和15.25％增至88.15％，71.81％和46.72％，而原花青素A ₁和PC _{A-三聚体分别}连续下降至27.13％和28.89％。发现异构体，水解和缩合反应在体外消化中起主要作用。此外，如MTT分析和谷胱甘肽（GSH）的测定所表明，与其他化合物及其DPs相比，原花青素A ₁及其DPs对ACR诱导的细胞毒性表现出最好的保护作用。