title: Antioxidant status and biomarkers of oxidative stress in dogs with lymphoma.
abstract: BACKGROUND
  Oxidative stress might play a role in carcinogenesis, as well as impacting morbidity and mortality of veterinary cancer patients. The purpose of this study was to evaluate antioxidant concentrations and biomarkers of oxidative stress in dogs with newly diagnosed lymphoma before treatment and once in remission, with comparison with healthy controls.
  
  
  OBJECTIVE
  Dogs with lymphoma have increased oxidant and reduced antioxidant concentrations compared with healthy controls, and that these abnormalities normalize once remission is achieved.
  
  
  METHODS
  Seventeen dogs with lymphoma and 10 healthy controls.
  
  
  METHODS
  Prospective, observational study. Measures of oxidative stress [malondialdehyde and total isoprostanes (isoP)] and antioxidants [alpha-tocopherol, gamma-tocopherol, oxygen radical absorbance capacity (ORAC), and glutathione peroxidase (GSHPx)] were assessed in dogs with newly diagnosed lymphoma before treatment compared with healthy control dogs. The same parameters were measured in the dogs with lymphoma on week 7 of the chemotherapy protocol when all dogs were in remission.
  
  
  RESULTS
  At baseline, dogs with lymphoma had significantly lower alpha-tocopherol (P <.001) and gamma-tocopherol (P= .003) but higher GSHPx (P= .05), ORAC (P= .001), and isoP (P < .001) compared with healthy controls. In the dogs with lymphoma, alpha-tocopherol concentrations were higher (P= .005) and ascorbic acid were lower (P= .04) after treatment.
  
  
  CONCLUSIONS
  Results suggest that dogs with lymphoma have alterations in oxidant and antioxidant concentrations and that the status of some of these biomarkers normalize after remission. Further studies are warranted to determine whether antioxidant interventions to correct these are beneficial in the treatment of canine lymphoma.
authors.affiliation: Department of Clinical Sciences, Tufts Cummings School of Veterinary Medicine, North Grafton, MA 01536, USA.
authors.forename: J L
authors.initials: JL
authors.lastname: Winter
authors.forename: L G
authors.initials: LG
authors.lastname: Barber
authors.forename: L
authors.initials: L
authors.lastname: Freeman
authors.forename: P C
authors.initials: PC
authors.lastname: Griessmayr
authors.forename: P E
authors.initials: PE
authors.lastname: Milbury
authors.forename: J B
authors.initials: JB
authors.lastname: Blumberg
mesh_terms: D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D000975:Antioxidants / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000097:blood*; D004283:Dog Diseases / Q000097:blood* / Q000188:drug therapy; D004285:Dogs; D005260:Female; D005979:Glutathione Peroxidase / Q000097:blood; D028421:Isoprostanes / Q000097:blood; D008223:Lymphoma / Q000097:blood / Q000188:drug therapy / Q000662:veterinary*; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology*; D011446:Prospective Studies; D024502:alpha-Tocopherol / Q000097:blood; D024504:gamma-Tocopherol / Q000097:blood
chemical_list: D000975:Antioxidants; D014408:Biomarkers, Tumor; D028421:Isoprostanes; D008315:Malondialdehyde; D024504:gamma-Tocopherol; D005979:Glutathione Peroxidase; D024502:alpha-Tocopherol