苹果是人类的重要膳食成分，而苹果多酚（AP）是苹果的主要次生代谢产物。本研究通过细胞存活率、氧化应激变化以及细胞凋亡等方面，研究了AP对氢氧化物（H2O2）诱导的人类结肠腺癌Caco-2细胞氧化应激损伤的保护作用。预先添加AP可以显著提高H2O2处理的Caco-2细胞的生存率，同时抗氧化酶超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-PX）和过氧化氢酶（CAT）的活性升高，而多不饱和脂肪酸（PUFA）的主要氧化产物马来醛（MDA）含量在AP处理后降低。此外，AP还抑制了DNA碎片的出现并减少了凋亡相关蛋白Caspase-3的表达。这些结果表明，AP能够改善Caco-2细胞中的H2O2诱导氧化应激损伤，为苹果天然活性成分的进一步研究和抗氧化应激机制的深入研究提供了参考。

Apple is an important dietary agent for human and apple polyphenols (AP) are the main secondary metabolites of apples. In this study, the protective effects of AP on hydrogen peroxide (H2O2)-induced oxidative stress damage in human colon adenocarcinoma Caco-2 cells were investigated by cell viability, oxidative stress change as well as cell apoptosis. Pre-adding AP could significantly increase the survival rate of H2O2-treated Caco-2 cells. Besides, the activities of antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GSH-PX) and catalase (CAT) were elevated. While the malondialdehyde (MDA) content which is the major oxidant products of polyunsaturated fatty acids (PUFA) reduced after AP treatment. In addition, AP also suppressed the emergence of DNA fragment and decreased the expression of apoptosis-related protein Caspase-3. These results demonstrated that AP could ameliorate H2O2-induced oxidative stress damage in Caco-2 cells, which could serve as a reference for further studies of apple natural active products and deep study of the anti-oxidative stress mechanism.