Cyclosporine effects on the antioxidant capacity of rat renal tissues

OBJECTIVE: Cyclosporine (CsA) has been shown to improve long-term survival after organ transplantation. However, CsA therapy is associated with a variety of side effects, among which nephropathy is the major one. Recent studies have suggested increased oxidative stress as a cause of drug nephrotoxicity. Therefore, this study was designed to evaluate the effects of CsA administration on the antioxidant capacity of kidney tissue. METHODS: Adult male Sprague-Dawley rats were randomly assigned into 2 groups: one group received CsA (25 mg/kg/d, IP for 2 weeks) and a control group (no CsA administration). After 2 weeks, the kidneys of the rats from both groups were removed under anesthesia. A 50 mg fresh kidney tissue sample was homogenized in ice-cold phosphate buffer. Total antioxidant capacity (Ferric Reducing Ability of Plasma FRAP]) in the homogenates was assayed based on the Benzie spectrophotometric method. RESULTS: FRAP in the kidney tissues had been significantly decreased by 2 weeks of CsA administration when compared with control rats (P<.05). CONCLUSIONS: These data suggested that CsA administration may decrease the antioxidant capacity of renal tissues. More studies on the evaluation of the protective effects of antioxidant therapy against CsA nephrotoxicity are underway.