Serum biomarkers of oxidative stress in dogs with idiopathic inflammatory bowel disease.

The objective of this work was to study and compare a panel of various serum biomarkers evaluating both the antioxidant response and oxidative damage in dogs with idiopathic inflammatory bowel disease (IBD). Eighteen dogs with IBD and 20 healthy dogs were enrolled in the study. Trolox equivalent antioxidant capacity (TEAC), cupric reducing antioxidant capacity (CUPRAC), ferric reducing ability of the plasma (FRAP), total thiol concentrations, and paraoxonase 1 (PON1) activity were evaluated in serum to determine antioxidant response. To evaluate oxidative status, ferrous oxidation-xylenol orange (FOX), thiobarbituric acid reactive substances (TBARS) and reactive oxygen species production (ROS) concentrations in serum were determined. Mean concentrations of all antioxidant biomarkers analyzed, with exception of FRAP, were significantly lower (P < 0.0001) in the sera of dogs with IBD than in healthy dogs. The oxidant markers studied were significantly higher (P < 0.0001) in sera of dogs with IBD than in healthy dogs. These findings support the hypothesis that oxidative stress could play an important role in the pathogenesis of canine IBD.