title: Urinary hydrogen peroxide: a probable marker of oxidative stress in malignancy.
abstract: BACKGROUND
  Urinary hydrogen peroxide was postulated to be a biomarker of oxidative stress. We estimated urinary hydrogen peroxide along with other established parameters of oxidative stress in malignancies where oxidative stress is well documented.
  
  
  METHODS
  The oxidative stress markers tested were concentrations of erythrocyte glutathione, erythrocyte malonaldehyde (MDA) and plasma hydroperoxide, and activities of plasma glutathione-S-transferase (GST) and erythrocyte catalase. Urinary hydrogen peroxide was measured by a modified ferrous ion oxidation xylenol orange version-2 (FOX-2) method on a spot random sample of urine.
  
  
  RESULTS
  In healthy controls (n=10), erythrocyte glutathione concentration was 4.41+/-0.057mg/g of hemoglobin, plasma hydroperoxide was 2.5+/-0.07 micromol/l, erythrocyte MDA was 0.9+/-0.15 nmol/ml of packed cell suspension and erythrocyte catalase and plasma GST were 74.66+/-9.2/s/ml of packed cell suspension and 6.12+/-0.84 IU/l, respectively. In cancer patients (n=25), erythrocyte glutathione, plasma hydroperoxide and erythrocyte MDA were 9.32+/-0.42 mg/g of hemoglobin, 6.2+/-0.13 micromol/l and 2.3+/-0.27 nmol/ml of packed cell suspension, respectively; and activities of erythrocyte catalase and plasma GST were 151.04+/-6.5/s/ml of packed cell suspension and 10.9+/-0.36 IU/l, respectively. Urinary hydrogen peroxide concentration was 15+/-9.8 micromol/l in the healthy controls and 56.3+/-3.9 micromol/l in cancer patients.
  
  
  CONCLUSIONS
  Urinary hydrogen peroxide may be a marker of oxidative stress in malignancies.
authors.affiliation: Department of Biochemistry, Kasturba Medical College, Manipal, Karnataka State 576119, India. dibo52000@yahoo.co.in
authors.forename: Dibyajyoti
authors.initials: D
authors.lastname: Banerjee
authors.forename: U K
authors.initials: UK
authors.lastname: Madhusoodanan
authors.forename: Sudhakar
authors.initials: S
authors.lastname: Nayak
authors.forename: Jose
authors.initials: J
authors.lastname: Jacob
mesh_terms: D015415:Biomarkers; D002374:Catalase / Q000097:blood; D002851:Chromatography, High Pressure Liquid; D003404:Creatinine / Q000652:urine; D004912:Erythrocytes / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D005982:Glutathione Transferase / Q000097:blood; D006801:Humans; D006861:Hydrogen Peroxide / Q000097:blood / Q000652:urine*; D007202:Indicators and Reagents; D008315:Malondialdehyde / Q000097:blood; D009369:Neoplasms / Q000378:metabolism* / Q000652:urine*; D018384:Oxidative Stress / Q000502:physiology*; D013056:Spectrophotometry, Ultraviolet; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
chemical_list: D015415:Biomarkers; D007202:Indicators and Reagents; D017392:Thiobarbituric Acid Reactive Substances; D008315:Malondialdehyde; D003404:Creatinine; D006861:Hydrogen Peroxide; D002374:Catalase; D005982:Glutathione Transferase; D005978:Glutathione