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Antioxidant Supplementation Enhances Erythrocyte Antioxidant Status and Attenuates Cyclosporine‐Induced Vascular Dysfunction
Author(s) -
Lexis L.A.,
Fenning A.,
Brown L.,
Fassett R.G.,
Coombes J.S.
Publication year - 2006
Publication title -
american journal of transplantation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.89
H-Index - 188
eISSN - 1600-6143
pISSN - 1600-6135
DOI - 10.1111/j.1600-6143.2005.01154.x
Subject(s) - glutathione peroxidase , antioxidant , superoxide dismutase , medicine , endocrinology , glutathione , malondialdehyde , pharmacology , biochemistry , oxidative stress , chemistry , enzyme
The aim of this study was to determine the effects of dietary antioxidant supplementation with α‐tocopherol and α‐lipoic acid on cyclosporine‐induced alterations to erythrocyte and plasma redox balance, and cyclosporine‐induced endothelial and smooth muscle dysfunction. Rats were randomly assigned to either control, antioxidant, cyclosporine or cyclosporine + antioxidant treatments. Cyclosporine A was administered for 10 days after an 8‐week feeding period. Plasma was analyzed for α‐tocopherol, total antioxidant capacity, malondialdehyde and creatinine. Erythrocytes were analyzed for glutathione, methemoglobin, superoxide dismutase, catalase, glutathione peroxidase, glucose‐6‐phosphate dehydrogenase, α‐tocopherol and malondialdehye. Vascular endothelial and smooth muscle function was determined in vitro . Antioxidant supplementation resulted in significant increases in erythrocyte α‐tocopherol concentration and glutathione peroxidase activity in both of the antioxidant‐supplemented groups. Cyclosporine administration caused significant decreases in glutathione concentration, methemoglobin concentration and superoxide dismutase activity. Antioxidant supplementation attenuated the cyclosporine‐induced decrease in superoxide dismutase activity. Cyclosporine therapy impaired both endothelium‐independent and ‐dependent relaxation of the thoracic aorta, and this was attenuated by antioxidant supplementation. In summary, dietary supplementation with α‐tocopherol and α‐lipoic acid attenuated the cyclosporine‐induced decrease in erythrocyte superoxide dismutase activity and attenuated cyclosporine‐induced vascular dysfunction.