title: The antioxidative effect of bread crust in a mouse macrophage reporter cell line.
abstract: OBJECTIVE
  Free radicals and oxidative stress are important factors in the biology of aging and responsible for the development of age-related diseases. One way to reduce the formation of free radicals is to boost the antioxidative system by nutrition. Heat treatment of food promote the Maillard reaction which is responsible for their characteristic color and taste. During the Maillard reaction reducing sugars react with proteins in a non-enzymatic way leading to the formation of advanced glycation end products (AGEs). As an AGE-rich source our group used bread crust (BCE) to investigate the effect of AGEs on the antioxidant defense.
  
  
  METHODS
  It is well known that the NF-kB pathway is activated by treatment of cells with AGEs. Therefore for stimulation with the BCE we used the macrophage reporter cell line RAW/NF-kB/SEAPorter™. Amino acid analysis and LC-MS/MS by Orbitrap Velo was used to determine the bioactive compounds in the soluble BCE. The radical scavenging effect was conducted by the DPPH-assay.
  
  
  RESULTS
  BCE induced the NF-kB pathway in RAW/NF-kB/SEAPorter™ cells and also showed a concentration-dependent antioxidative capacity by the DPPH-assay. With the LC/MS and amino acid analyses, we identified the presence of gliadin in BCE confirmed by using specific gliadin antibodies. By immunoprecipitation (IP) with an antibody against γ-gliadin and western blot probing against the AGE carboxymethyllysine (CML) the presence of AGE-gliadin in BCE was confirmed. Stimulation of the RAW/NF-kB/SEAPorter™ cells with the γ-gliadin depleted fractions did not activate the NF-kB pathway.
  
  
  CONCLUSIONS
  CML-modified gliadin in the BCE is a bioactive compound of the bread crust which is responsible for the antioxidative capacity and for the induction of the NF-kB pathway in mouse macrophages.
authors.affiliation: University Hospital (Martin-Luther University Halle-Wittenberg), Department of Cardiothoracic Surgery, Germany.
authors.forename: Sandy
authors.initials: S
authors.lastname: Pötzsch
authors.affiliation: Institut National de la Recherche Agronomique (Unité Biopolymères, Interactions Assemblages), Edifices lipoprotéiques et protéopolysaccharidiques, France.
authors.forename: Michele
authors.initials: M
authors.lastname: Dalgalarrondo
authors.affiliation: Institut National de la Recherche Agronomique (Unité Biopolymères, Interactions Assemblages), Edifices lipoprotéiques et protéopolysaccharidiques, France.
authors.forename: Benedicte
authors.initials: B
authors.lastname: Bakan
authors.affiliation: Institut National de la Recherche Agronomique (Unité Biopolymères, Interactions Assemblages), Edifices lipoprotéiques et protéopolysaccharidiques, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Marion
authors.affiliation: University of Vienna (Vienna), Department of Nutritional and Physiological Chemistry, Austria.
authors.forename: Veronika
authors.initials: V
authors.lastname: Somoza
authors.affiliation: Martin-Luther-University Halle-Wittenberg (Halle (Saale)), Institute of Agricultural and Nutritional Sciences, Germany.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Stangl
authors.affiliation: University Hospital (Martin-Luther University Halle-Wittenberg), Department of Cardiothoracic Surgery, Germany.
authors.forename: Rolf-Edgar
authors.initials: RE
authors.lastname: Silber
authors.affiliation: University Hospital (Martin-Luther University Halle-Wittenberg), Department of Cardiothoracic Surgery, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Simm
authors.affiliation: University Hospital (Martin-Luther University Halle-Wittenberg), Department of Cardiothoracic Surgery, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Navarrete Santos