Intracellular ROS scavenging and antioxidant enzyme regulating capacities of corn gluten meal-derived antioxidant peptides in HepG2 cells

Liying Wang; Long Ding; Zhipeng Yu; Ting Zhang; Shuang Ma; Jingbo Liu

doi:10.1016/j.foodres.2016.10.023

Intracellular ROS scavenging and antioxidant enzyme regulating capacities of corn gluten meal-derived antioxidant peptides in HepG2 cells

Food Res Int. 2016 Dec:90:33-41. doi: 10.1016/j.foodres.2016.10.023. Epub 2016 Oct 15.

Authors

Liying Wang¹, Long Ding¹, Zhipeng Yu², Ting Zhang¹, Shuang Ma¹, Jingbo Liu³

Affiliations

¹ Laboratory of Nutrition and Functional Food, Jilin University, Changchun 130062, People's Republic of China.
² College of Food Science and Engineering, Bohai University, Jinzhou 121013, People's Republic of China.
³ Laboratory of Nutrition and Functional Food, Jilin University, Changchun 130062, People's Republic of China. Electronic address: ljb168@sohu.com.

PMID: 29195889
DOI: 10.1016/j.foodres.2016.10.023

Abstract

The objective of this study was to investigate the intracellular reactive oxygen species (ROS) scavenging activities and antioxidant enzyme regulating capacities of corn gluten peptide fractions (CPFs) in HepG2 cells. A cellular antioxidant activity (CAA) assay was used to assess their antioxidant activities and revealed that both CPF1 (molecular weight <1kDa) and CPF2 (molecular weight between 1 and 3kDa) exhibited high cellular antioxidant activities with EC₅₀ values of 2.85±0.19mg/mL and 5.05±0.32mg/mL, respectively. Both CPFs also exhibited cytoprotective effects and intracellular ROS scavenging activities in HepG2 cells subjected to oxidative stress by oxidation with H₂O₂. In addition, at concentrations of 2.50mg/mL, the CPFs increased the activity levels of superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GR), as well as the total glutathione (GSH) levels in oxidized HepG2 cells (from 86.54% to 114.14% (CPF1) or 109.72% (CPF2) for SOD activity; from 71.91% to 107.64% (CPF1) or 106.50% (CPF2) for CAT activity; from 70.52% to 103.01% (CPF1) or 104.10% (CPF2) for GR activity; and from 81.39% to 114.00% (CPF1) or 108.82% (CPF2) for total GSH levels). These results suggested that both CPF1 and CPF2 exhibited positive effects on the activities of the intracellular antioxidant enzymes SOD, CAT and GR, as well as on the total GSH levels in HepG2 cells under conditions of oxidative stress. Furthermore, size exclusion gel chromatography and MALDI-TOF/TOF mass spectrometry revealed that the molecular weights of the antioxidant peptides in CPF1 were between 500Da to 900Da, and a novel antioxidant peptide consisting of GLLLPH (Gly-Leu-Leu-Leu-Pro-His) was identified in CPF1.

Keywords: Antioxidant enzyme; Antioxidant peptide; Corn; HepG2 cell; ROS.