Identification of novel antioxidant peptides from snakehead (Channa argus) soup generated during gastrointestinal digestion and insights into the anti-oxidation mechanisms. (1st February 2021)

• Record Type: Journal Article
• Authors: Zhang, Jin; Li, Mei; Zhang, Gaonan; Tian, Yu; Kong, Fanbin; Xiong, Shanbai; Zhao, Siming; Jia, Dan; Manyande, Anne; Du, Hongying
• Is Part Of: Food chemistry. Volume 337(2021)
• Publication Date: 2021-02-01
• Subjects: Antioxidant peptides -- Snakehead soup -- Gastrointestinal digestion -- Molecular docking -- UPLC-MS/MS -- RP-HPLC -- Kelch-like ECH-associated protein 1 -- Cytoprotective effect; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2020.127921
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: Antioxidant peptides from digestion of snakehead soup were studied for the first time. Four novel antioxidant peptides (8–17 amino acids) were identified by UPLC-MS/MS. 3D structure and interactions with Keap1 were studied using in silico simulation. Cytoprotective effect was studied using the H2 O2 -induced HepG2 cell damage model. Abstract: Antioxidant peptides obtained from snakehead ( Channa argus ) soup (SHS) after simulated gastrointestinal (GI) digestion were separated, identified and characterized. Results showed that the fraction with MW < 3 kDa had the highest antioxidant capacity. Four novel antioxidant peptides were identified after RP-HPLC and UPLC-MS/MS. PGMLGGSPPGLLGGSPP and SDGSNIHFPN had the highest DPPH radical scavenging activity (IC50 = 1.39 mM) and Fe 2+ chelating ability (IC50 = 4.60 mM), respectively. Structures in silico for IVLPDEGK, PGMLGGSPPGLLGGSPP and SDGSNIHFPN suggest at least one β-turn and/or α-helix, which are associated with antioxidant activity. Moreover, our results showed that these three peptides docked with a recombinant Kelch-like ECH-associated protein 1 (Keap1) with a binding score greater than TX6, a good ligand of Keap1. The cell viability assay also showed significant cytoprotective effects against H2 O2 -induced cellular oxidative damage. This information implies that antioxidant mechanisms of novel SHS peptides occurred via activation of cellular anti-oxidation Keap1-Nrf2 signaling pathway.