Lim Sun Ha, Han Mee-Jung, Lee You Mie, Lee Jongwon
Department of Biochemistry, School of Medicine, Catholic University of Daegu, Daegu 42472, Korea.
Department of Biomolecular and Chemical Engineering, Dongyang University, Gyeongbuk 36040, Korea.
Prev Nutr Food Sci. 2018 Dec;23(4):309-316. doi: 10.3746/pnf.2018.23.4.309. Epub 2018 Dec 31.
We have previously shown that supplementation of wheat with hot-water extract reduces myocardial injury by inhibiting apoptosis in a rat model of myocardial infarction (MI). Arabinogalactan-peptide (AGP), a cell wall polysaccharide of wheat, was also responsible for the protection. However, the underlying mechanisms were not elucidated. In this study, we investigated the underlying mechanisms for how AGP supplementation reduces myocardial injury. First, we isolated highly pure AGP from all-purpose wheat flour. We supplemented rats with AGP at a dose of 100 mg/kg/d for 3 days, and subjected the rats to ischemia (30 min) through ligation of the left anterior descending coronary artery followed by reperfusion (3 h) through a release of the ligation. Supplementation with AGP significantly reduced the infarct size in the heart. In addition, AGP intake inhibited the apoptotic cascade, determined through decreased mitogen-activated protein kinases (p38 and c-Jun N-terminal kinase) phosphorylation, decreased Bcl-2-associated X protein/B-cell lymphoma ratios, and decreased generation of nicked DNA, which was confirmed through western blotting and terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling staining. These findings indicate that AGP intake can protect against myocardial injury. Traditionally, consumption of dietary fiber such as AGP has been shown to reduce MI risk by inhibiting preocclusion steps through reducing risk factors. Our findings suggest that AGP intake can also reduce MI risk by inhibiting postocclusion steps. This study describes a better dietary recommendation and new prevention strategy for reducing MI risk through regular consumption of wheat rich in AGP.
我们之前已经表明，在小麦中添加热水提取物可通过抑制心肌梗死（MI）大鼠模型中的细胞凋亡来减轻心肌损伤。阿拉伯半乳聚糖肽（AGP）是小麦的一种细胞壁多糖，也起到了保护作用。然而，其潜在机制尚未阐明。在本研究中，我们探究了补充AGP减轻心肌损伤的潜在机制。首先，我们从通用小麦粉中分离出了高纯度的AGP。我们以100 mg/kg/d的剂量给大鼠补充AGP，持续3天，然后通过结扎左冠状动脉前降支使大鼠缺血30分钟，随后松开结扎进行3小时的再灌注。补充AGP可显著减小心脏梗死面积。此外，通过蛋白免疫印迹法和末端脱氧核苷酸转移酶介导的dUTP缺口末端标记染色证实，摄入AGP可抑制凋亡级联反应，表现为丝裂原活化蛋白激酶（p38和c-Jun氨基末端激酶）磷酸化水平降低、Bcl-2相关X蛋白/B细胞淋巴瘤比值降低以及切口DNA生成减少。这些发现表明，摄入AGP可预防心肌损伤。传统上，已表明食用膳食纤维（如AGP）可通过降低危险因素来抑制阻塞前步骤，从而降低MI风险。我们的研究结果表明，摄入AGP还可通过抑制阻塞后步骤来降低MI风险。本研究描述了一种更好的饮食建议和新的预防策略，即通过经常食用富含AGP的小麦来降低MI风险。
