title: Associations between glutathione peroxidase-1 Pro198Leu polymorphism, selenium status, and DNA damage levels in obese women after consumption of Brazil nuts.
abstract: OBJECTIVE
  Alterations in selenium (Se) status may result in suboptimal amounts of selenoproteins, which have been associated with increased oxidative stress levels. The Pro198Leu polymorphism at the glutathione peroxidase-1 (GPx1) gene is supposed to be functional. The response of Se status, GPx activity, and levels of DNA damage to a Se supplementation trial between the genotypes related to that polymorphism was investigated.
  
  
  METHODS
  A randomized trial was conducted with 37 morbidly obese women. Participants consumed one Brazil nut, which provided approximately 290 μg of Se a day, for 8 wk. Blood Se concentrations, erythrocyte GPx activity, and DNA damage levels were measured at baseline and at 8 wk. The results were compared by genotypes.
  
  
  RESULTS
  The genotype frequencies were 0.487, 0.378, and 0.135 for Pro/Pro (the wild-type genotype), Pro/Leu, and Leu/Leu, respectively. At baseline, 100% of the subjects were Se deficient, and after the supplementation, there was an improvement in plasma Se (P < 0.001 for Pro/Pro and Pro/Leu, P < 0.05 for Leu/Leu), erythrocyte Se (P = 0.00 for Pro/Pro and Pro/Leu, P < 0.05 for Leu/Leu), and GPx activity (P = 0.00 for Pro/Pro, P < 0.00001 for Pro/Leu, P < 0.001 for Leu/Leu). In addition, the Pro/Pro group showed a decrease in DNA damage after Brazil nut consumption compared with baseline (P < 0.005), and those levels were higher in Leu/Leu subjects compared with those with the wild-type genotype (P < 0.05).
  
  
  CONCLUSIONS
  Consumption of one unit of Brazil nuts daily effectively increases Se status and increases GPx activity in obese women, regardless of GPx1 Pro198Leu polymorphism. However, the evaluated biomarkers showed distinct results in response to the supplementation when the polymorphism was considered.
authors.affiliation: Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Science, University of São Paulo, São Paulo, Brazil. ccominet@usp.br
authors.forename: Cristiane
authors.initials: C
authors.lastname: Cominetti
authors.forename: Maritsa Carla
authors.initials: MC
authors.lastname: de Bortoli
authors.forename: Eduardo
authors.initials: E
authors.lastname: Purgatto
authors.forename: Thomas Prates
authors.initials: TP
authors.lastname: Ong
authors.forename: Fernando Salvador
authors.initials: FS
authors.lastname: Moreno
authors.forename: Arthur Belarmino
authors.initials: AB
authors.lastname: Garrido
authors.forename: Silvia Maria Franciscato
authors.initials: SM
authors.lastname: Cozzolino
mesh_terms: D000293:Adolescent; D000328:Adult; D031383:Bertholletia / Q000737:chemistry*; D015415:Biomarkers / Q000097:blood; D004249:DNA Damage; D003677:Deficiency Diseases / Q000178:diet therapy / Q000378:metabolism*; D019587:Dietary Supplements; D005260:Female; D005838:Genotype; D005979:Glutathione Peroxidase / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D044623:Nutrition Therapy; D009752:Nutritional Status; D009754:Nuts / Q000737:chemistry; D009767:Obesity, Morbid / Q000235:genetics / Q000378:metabolism*; D018384:Oxidative Stress; D020641:Polymorphism, Single Nucleotide; D012643:Selenium / Q000097:blood* / Q000172:deficiency / Q000494:pharmacology; D000094765:Glutathione Peroxidase GPX1
chemical_list: D015415:Biomarkers; D005979:Glutathione Peroxidase; D012643:Selenium; D000094765:Glutathione Peroxidase GPX1