Assessment of oxidative stress in leukocytes and granulocyte function following oral administration of a silibinin-phosphatidylcholine complex in cats.
OBJECTIVE
To determine the effect of oral administration of a silibinin-phosphatidylcholine complex (SPC) on oxidative stress in leukocytes and granulocyte function in healthy cats.


METHODS
10 purpose-bred adult cats.


METHODS
Cats were administered SPC (10 mg/kg/d) orally for 5 days; blood samples were collected prior to and immediately after the 5-day treatment period. Leukocytes were incubated with monochlorobimane for detection of reduced glutathione (GSH) via flow cytometry. Leukocytes were also incubated with dihydrorhodamine 123 and mixed with Escherichia coli conjugated to a fluorescent marker to measure E coli phagocytosis and the subsequent oxidative burst via flow cytometry. Activities of the antioxidant enzymes superoxide dismutase and glutathione peroxidase, along with the reduced glutathione-to-oxidized glutathione (GSH:GSSG) ratio and a measure of lipid peroxidation (malondialdehyde concentration [micromol/L of blood]), were measured spectrophotometrically.


RESULTS
The mean fluorescence intensity (MFI), representing GSH content, increased significantly in feline lymphocytes and granulocytes following 5 days of oral administration of SPC. Mean +/- SD lymphocyte MFI significantly increased from 27.8 +/- 9.0 to 39.6 +/- 6.7, and the granulocyte MFI increased from 508.6 +/- 135.6 to 612.1 +/- 122.9. Following 5 days of SPC administration, the percentage of phagocytic cells that were responding optimally significantly increased (from 37 +/- 11.8% to 45 +/- 17.5%). Other measures of oxidative stress did not change significantly.


CONCLUSIONS
In cats, oral administration of supplemental SPC appears to increase granulocyte GSH content and phagocytic function, both of which would be potentially beneficial in cats with diseases associated with oxidative stress.
Webb
Craig B
CB
Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA.
McCord
Kelly W
KW
Twedt
David C
DC
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D002415:Cats / Q000097:blood*; D005260:Female; D005434:Flow Cytometry / Q000662:veterinary; D005978:Glutathione / Q000097:blood; D005979:Glutathione Peroxidase / Q000097:blood; D006098:Granulocytes / Q000187:drug effects* / Q000378:metabolism; D007962:Leukocytes / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects*; D010587:Phagocytosis; D010713:Phosphatidylcholines / Q000737:chemistry / Q000494:pharmacology*; D016897:Respiratory Burst; D000077385:Silybin; D012838:Silymarin / Q000737:chemistry / Q000494:pharmacology; D013482:Superoxide Dismutase / Q000097:blood
D000975:Antioxidants; D010713:Phosphatidylcholines; D012838:Silymarin; D000077385:Silybin; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005978:Glutathione