Effects of dietary antioxidant supplementation before and after oral acetaminophen challenge in cats.
OBJECTIVE
To determine effects of lipoic acid, vitamin E, and cysteine before and after oxidant challenge in cats.


METHODS
24 sexually intact adult cats.


METHODS
Cats were allocated into 4 equal groups. For 25 weeks, group A was fed a control dry diet and groups B, C, and D received this diet supplemented with vitamin E (2200 U/kg [dry matter basis {DMB}]) plus cysteine (9.5 g/kg [DMB]), lipoate (150 mg/kg [DMB]), or all 3 antioxidants together, respectively. Weights were measured every 3 days and venous blood obtained every 5 weeks for CBC; serum biochemical analyses; lymphocyte blastogenesis; thiobarbituric acid reactive substances concentration; and concentrations of plasma protein carbonyl, 8-OH d-guanosine, blood glutathione, plasma amino acid, lipoate, and dihydrolipoate. At 15 weeks, all cats received acetaminophen (9 mg/kg, PO, once), clinical effects were observed, and methemoglobin concentrations were measured.


RESULTS
Lymphocyte blastogenesis increased transiently in group C and D cats. After acetaminophen administration, all groups had transient increases in methemoglobin within 4 hours and mild, brief facial edema; group C had decreased glutathione concentration and increased 8-OH d-guanosine concentration versus controls; and protein carbonyl concentration increased least for group B. Plasma lipoate and dihydrolipoate concentrations peaked by week 10 for groups C and D. Conclusions and Clinical Relevance-Lipoate, vitamin E, and cysteine did not have synergistic effects. Lipoate supplementation (150 mg/kg [DMB]) did not act as an antioxidant but appeared to enhance oxidant effects of acetaminophen. Vitamin E plus cysteine had protective effects.
Hill
Ana S
AS
Department of Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA.
Rogers
Quinton R
QR
O'Neill
Sharron L
SL
Christopher
Mary M
MM
D000080242:8-Hydroxy-2'-Deoxyguanosine / Q000031:analogs & derivatives; D000082:Acetaminophen / Q000008:administration & dosage / Q000494:pharmacology*; D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage*; D015415:Biomarkers / Q000097:blood; D002415:Cats; D002851:Chromatography, High Pressure Liquid / Q000662:veterinary; D003545:Cysteine / Q000008:administration & dosage*; D019587:Dietary Supplements; D004359:Drug Therapy, Combination; D005260:Female; D005978:Glutathione / Q000097:blood / Q000187:drug effects; D006147:Guanine / Q000031:analogs & derivatives* / Q000097:blood; D008213:Lymphocyte Activation / Q000187:drug effects; D008214:Lymphocytes / Q000187:drug effects; D008297:Male; D008706:Methemoglobin / Q000032:analysis / Q000187:drug effects; D008063:Thioctic Acid / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000097:blood; D014810:Vitamin E / Q000008:administration & dosage*
D018712:Analgesics, Non-Narcotic; D000975:Antioxidants; D015415:Biomarkers; D014810:Vitamin E; D000082:Acetaminophen; D006147:Guanine; C078307:8-oxo-7,8-dihydrodeoxyguanine; D008063:Thioctic Acid; C015144:dihydrolipoic acid; D000080242:8-Hydroxy-2'-Deoxyguanosine; D008706:Methemoglobin; D005978:Glutathione; D003545:Cysteine