title: Charge properties of peptides derived from casein affect their bioavailability and cytoprotection against H2O2-induced oxidative stress.
abstract: The effects of charge properties of casein peptides on absorption stability, antioxidant activity, and cytoprotection were evaluated. Alcalase hydrolysates of casein were separated into 4 fractions by cation-exchange chromatography according to charge properties. After simulated digestion and Caco-2 cell transmembrane transport, we determined the total antioxidant capacity (Trolox equivalent antioxidative capacity and oxygen radical antioxidant activity) and nitrogen content of peptide fractions to estimate available antioxidant efficacy and bioavailability (BA) of peptides. Results showed that negatively charged peptide fractions had greater BA and antioxidant activities after digestion and absorption. The peptide permeates were used to test the cytoprotective effect against H2O2-induced oxidative damage in HepG-2 cells. All peptide permeates increased cell viability, elevated catalase activity, and decreased superoxide dismutase activity. However, negatively charged peptide fractions preserved cell viability to a greater degree. Therefore, the negatively charged peptides from casein may be potential antioxidants and could be used as ingredients in functional foods and dietary supplements.
authors: College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China.
authors: Bo
authors: B
authors: Wang
authors: Institute of Agro-food Science and Technology, Anhui Academy of Agricultural Sciences, Hefei, 230031, China.
authors: Ningning
authors: N
authors: Xie
authors: College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China; Beijing Higher Institution Engineering Research Center of Animal Product, Beijing, 100083, China. Electronic address: libo@cau.edu.cn.
authors: Bo
authors: B
authors: Li
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000032:analysis / Q000378:metabolism*; D001682:Biological Availability; D018938:Caco-2 Cells; D002364:Caseins / Q000378:metabolism*; D002470:Cell Survival; D019610:Cytoprotection; D004063:Digestion; D006801:Humans; D006861:Hydrogen Peroxide / Q000009:adverse effects*; D018384:Oxidative Stress; D010455:Peptides / Q000737:chemistry* / Q000302:isolation & purification / Q000493:pharmacokinetics; D017382:Reactive Oxygen Species / Q000032:analysis / Q000378:metabolism
chemical_list: D000975:Antioxidants; D002364:Caseins; D010455:Peptides; D017382:Reactive Oxygen Species; D006861:Hydrogen Peroxide
keywords: HepG-2 cells; antioxidative peptide; bioavailability; casein; charge property