title: Lipid peroxidation as determined by plasma isoprostanes is related to disease severity in mild asthma.
abstract: Oxidlative stress is believed to play an important role in the pathophysiology of asthma. Recently discovered F2-isoprostanes, of which 8-iso-PGF2alpha is the most well-known isomer, have emerged as the most reliable marker of in vivo oxidative stress. The aim of this study was to examine 8-iso-PGF2alpha as a biomarker of oxidative stress in mild asthma in relation to endogenous and dietary antioxidant protection. Total (free and esterified) plasma 8-iso-PGF2alpha, plasma dietary antioxidants (vitamins E and C, Beta-carotene, Zn, and Se), and erythrocyte antioxidant enzyme activities (glutathione peroxidase and superoxide dismutase) were measured in 15 mild asthmatics and 15 age-and sex-matched controls. Total plasma 8-iso-PGF2alpha levels [median (quartile 1 - quartile 3)] were significantly increased in the asthmatics [213 pg/mL (122-455) vs. 139 pg/mL (109-174), P= 0.042]. The 8-iso PGF2alpha levels were found to be associated with clinical asthma severity (P = 0.044) and inhaled corticosteroid use (P = 0.027) in asthmatics. No differences were observed in the plasma dietary antioxidant vitamins. The asthmatics had significantly lower plasma levels of Zn (P = 0.027) and Se (P = 0.006). Plasma Se correlated negatively with 8-iso-PGF2alpha (r = -0.725, P= 0.002). No differences between the groups were observed for glutathione peroxidase or superoxide dismutase, however, superoxide dismutase activity was negatively associated with asthma severity (P = 0.042). In conclusion, oxidative stress is increased in mildly asthmatics, as reflected by increased plasma levels of 8-iso-PGF2alpha and a deficiency in plasma Zn and Se. The isoprostane 8-iso-PGF2alpha may provide a useful tool in intervention studies aimed at improving clinical status in asthma.
authors.affiliation: Discipline of Nutrition and Dietetics, Faculty of Medicine and Health Sciences, University of Newcastle, New South Wales, Australia.
authors.forename: L G
authors.initials: LG
authors.lastname: Wood
authors.forename: D A
authors.initials: DA
authors.lastname: Fitzgerald
authors.forename: P G
authors.initials: PG
authors.lastname: Gibson
authors.forename: D M
authors.initials: DM
authors.lastname: Cooper
authors.forename: M L
authors.initials: ML
authors.lastname: Garg
mesh_terms: D000293:Adolescent; D000328:Adult; D000975:Antioxidants / Q000032:analysis / Q000378:metabolism*; D001249:Asthma / Q000097:blood* / Q000201:enzymology / Q000378:metabolism / Q000503:physiopathology*; D015415:Biomarkers / Q000097:blood; D001772:Blood Cell Count; D002648:Child; D004032:Diet; D015237:Dinoprost / Q000031:analogs & derivatives* / Q000097:blood / Q000378:metabolism; D004912:Erythrocytes / Q000201:enzymology / Q000378:metabolism; D028441:F2-Isoprostanes; D005260:Female; D005979:Glutathione Peroxidase / Q000378:metabolism; D006801:Humans; D015227:Lipid Peroxidation; D008297:Male; D008670:Metals / Q000097:blood; D018384:Oxidative Stress; D010641:Phenotype; D013482:Superoxide Dismutase / Q000378:metabolism; D014815:Vitamins / Q000097:blood / Q000378:metabolism
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D028441:F2-Isoprostanes; D008670:Metals; D014815:Vitamins; C075750:8-epi-prostaglandin F2alpha; D015237:Dinoprost; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase