School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, P. R. China.
School of Agriculture and Biology, Shanghai Jiaotong University, Shanghai, 200204, P. R. China.
Food Funct. 2022 May 23;13(10):5782-5793. doi: 10.1039/d2fo00199c.
Non-alcoholic fatty liver disease (NAFLD) is increasingly threatening human health. The remarkable effects of corn peptides (CPs) as bioactive peptides on liver protection have attracted much attention. Nevertheless, the specific effect of CPs on NAFLD remains unclear. The present study was designed to investigate the efficacy of CPs in the prevention and auxiliary treatment of high-fat diet (HFD)-induced NAFLD in SD rats, and puerarin was used as the positive control. SD rats were fed a high-fat diet to establish the NAFLD rat model, and LO2 cells were treated with a high concentration of fructose to simulate the NAFLD cell model. NAFLD was comprehensively examined in terms of body weight, liver function markers, serum biochemistry and liver histology. Protein expression was determined using western blot analysis. The results of animal experiments showed that CPs could effectively inhibit the rate of weight gain, reduce the blood lipid level and liver index, and enhance glucose tolerance. The results of cell experiments showed that CPs could effectively reduce the accumulation of lipids in LO2 cells and inhibit the accumulation of reactive oxygen species (ROS). In addition, CPs could markedly reduce liver lipid accumulation in the liver cell and liver tissue, as further evidenced by the reduced expression of SREBP-1c in human non-tumour hepatic (LO2) cells. Meanwhile, the increased expression of SIRT1/PPAR-α and Nrf2/HO-1 pathways under the pretreatment of CPs in LO2 cells indicated that CPs could markedly relieve high fat-induced fatty liver injury, regulate insulin sensitivity, and reduce production of ROS. The results of and experiments demonstrated that CPs provided potential prevention and auxiliary treatment for NAFLD through reducing lipid accumulation, alleviating insulin resistance, and inhibiting oxidative stress. This study investigated the biological activity of CPs and laid the theoretical basis for the development of CP-based functional foods and dietary supplements.
非酒精性脂肪性肝病（NAFLD）日益威胁人类健康。玉米肽作为生物活性肽对肝脏保护的显著作用引起了广泛关注。然而，玉米肽对 NAFLD 的具体作用尚不清楚。本研究旨在探讨玉米肽对 SD 大鼠高脂饮食（HFD）诱导的 NAFLD 的预防和辅助治疗作用，并以葛根素作为阳性对照。SD 大鼠给予高脂饮食建立 NAFLD 大鼠模型，LO2 细胞用高浓度果糖处理模拟 NAFLD 细胞模型。从体重、肝功能标志物、血清生化和肝组织学等方面综合评价 NAFLD。采用 Western blot 分析检测蛋白表达。动物实验结果表明，玉米肽能有效抑制体重增长速度，降低血脂水平和肝指数，提高葡萄糖耐量。细胞实验结果表明，玉米肽能有效减少 LO2 细胞内脂质堆积，抑制活性氧（ROS）的积累。此外，玉米肽能明显减少肝组织和肝细胞内的肝脂质堆积，人非肿瘤肝（LO2）细胞中 SREBP-1c 的表达降低进一步证实了这一点。同时，玉米肽预处理 LO2 细胞后 SIRT1/PPAR-α和 Nrf2/HO-1 通路表达增加，表明玉米肽能明显缓解高脂诱导的脂肪肝损伤，调节胰岛素敏感性，减少 ROS 的产生。和实验结果表明，玉米肽通过减少脂质积累、缓解胰岛素抵抗和抑制氧化应激，为 NAFLD 的防治提供了潜在的作用。本研究探讨了玉米肽的生物学活性，为开发基于玉米肽的功能性食品和膳食补充剂奠定了理论基础。
