Effect of a bioflavonoid dietary supplement on acetaminophen-induced oxidative injury to feline erythrocytes

Objective-To determine the effect of a commercial bioflavonoid antioxidant on acetaminophen-induced oxidative injury to feline erythrocytes. Design-Randomized controlled study. Animals-45 healthy age-matched cats. Procedure-Cats were assigned to 3 experimental groups. Groups 1 and 3 recei ved a bioflavonoid antioxidant (10 mg/d) orally for 2 weeks. Groups 2 and 3 received an oxidative challenge with acetaminophen (90 mg/kg [41 mg/lb] of body weight, PO) on day 7. Packed cell volume, percentage of erythrocytes with Heinz bodies, blood methemoglobin concentration, and blood reduced and oxidized glutathione concentrations were determined at various times durin g the 2-week study period. Results-Adverse effects were not associated with bioflavonoid antioxidant a dministration alone. Acetaminophen administration resulted in a significant increase in methemoglobin concentration in groups 2 and 3; differences wer e not detected between these groups. Heinz body concentrations in groups 2 and 3 Increased after acetaminophen administration; however, the increase i n cats that received the antioxidant was significantly less than in group-2 cats. Total blood glutathione concentrations did not change significantly in groups 2 and 3 after acetaminophen administration; however, ratio of red uced to oxidized glutathione concentration increased significantly after ad ministration in group-2 cats, compared with group-3 cats. Conclusions and Clinical Relevance-Oral administration of bioflavonoid anti oxidants to cats at risk for oxidative stress may have a beneficial effect on their ability to resist oxidative injury to erythrocytes.