title: A comprehensive evaluation of the enzymatic and nonenzymatic antioxidant systems in childhood asthma.
abstract: BACKGROUND
  Even though there is ample evidence on the oxidative stress in asthma, there is limited information on the antioxidant defense systems.
  
  
  OBJECTIVE
  To conduct a comprehensive evaluation of various components of both enzymatic and nonenzymatic antioxidants in a large group of children with asthma.
  
  
  METHODS
  A total of 164 children with mild asthma and 173 healthy children were included in the study. Levels of the enzymes glutathione peroxidase and superoxide dismutase were measured by using ELISA, whereas reduced glutathione, ascorbic acid, alpha-tocopherol, lycopene, beta-carotene, amino acids participating in glutathione synthesis, and amino acids susceptible to oxidation were measured by HPLC. All comparisons were adjusted for atopy, body mass index, smoke exposure, and pet ownership.
  
  
  RESULTS
  Levels of the enzymes glutathione peroxidase and superoxide dismutase and of the nonenzymatic components of the antioxidant system including reduced glutathione, ascorbic acid, alpha-tocopherol, lycopene, and beta-carotene were significantly lower in children with asthma compared with healthy controls (P < .001 for each). Of the amino acids contributing to glutathione synthesis, glycine and glutamine were significantly lower in children with asthma (P < .001). The majority of the amino acid susceptible to oxidative stress displayed lower levels in children with asthma (P < .05).
  
  
  CONCLUSIONS
  Childhood asthma is associated with significant decreases in various components of both enzymatic and nonenzymatic antioxidant defenses.
authors.affiliation: Pediatric Allergy and Asthma Unit, Hacettepe University School of Medicine, Ankara, Turkey. csackesen@yahoo.com
authors.forename: Cansin
authors.initials: C
authors.lastname: Sackesen
authors.forename: Hulya
authors.initials: H
authors.lastname: Ercan
authors.forename: Evrim
authors.initials: E
authors.lastname: Dizdar
authors.forename: Ozge
authors.initials: O
authors.lastname: Soyer
authors.forename: Pinar
authors.initials: P
authors.lastname: Gumus
authors.forename: Berat Nursal
authors.initials: BN
authors.lastname: Tosun
authors.forename: Zehra
authors.initials: Z
authors.lastname: Büyüktuncer
authors.forename: Erdem
authors.initials: E
authors.lastname: Karabulut
authors.forename: Tanju
authors.initials: T
authors.lastname: Besler
authors.forename: Omer
authors.initials: O
authors.lastname: Kalayci
mesh_terms: D000293:Adolescent; D000596:Amino Acids / Q000378:metabolism; D000975:Antioxidants / Q000378:metabolism*; D001205:Ascorbic Acid / Q000378:metabolism; D001249:Asthma / Q000276:immunology* / Q000378:metabolism*; D002338:Carotenoids / Q000378:metabolism; D002648:Child; D005260:Female; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D006801:Humans; D000077276:Lycopene; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D018384:Oxidative Stress; D013482:Superoxide Dismutase / Q000378:metabolism; D024502:alpha-Tocopherol / Q000378:metabolism; D019207:beta Carotene / Q000378:metabolism
chemical_list: D000596:Amino Acids; D000975:Antioxidants; D019207:beta Carotene; D002338:Carotenoids; D008315:Malondialdehyde; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005978:Glutathione; D024502:alpha-Tocopherol; D001205:Ascorbic Acid; D000077276:Lycopene