Effect of cyclosporine A on accumulation of tetraethylammonium and p-aminohippurate, and on lipid peroxidation in rat renal microsomes and cortical slices

Evaluating the Effect of Sulphated Polysaccharides on Cyclosporine A Induced Oxidative Renal Injury

Cyclosporine A (CsA) has been universally used as an immunosuppressant for the management of organ transplantation and various autoimmune diseases. However, nephrotoxicity due to CsA remains to be an important clinical challenge. In the present investigation, an attempt has been made to appraise the effect of sulphated polysaccharides on oxidative renal injury caused by CsA. Adult male Wistar rats were divided into four groups. Two groups received CsA by oral gavage (25 mg/kg body weight) for 21 days to provoke nephrotoxicity, one of which simultaneously received sulphated polysaccharides subcutaneously, (5 mg/kg body weight). A vehicle (olive oil) treated control group and sulphated polysaccharides drug control were also built-in. An increase in lipid peroxidation along with abnormal levels of enzymic (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione-S-transferase and glucose-6-phosphate dehydrogenase) and non-enzymic antioxidants (glutathione, vitamin C and vitamin E) are the salient features observed in CsA induced nephrotoxicity. CsA induced impairment of renal toxicity was evident from the marked decline in the activities of renal marker enzymes like alkaline phosphatase, acid phosphatase and lactate dehydrogenase, as well as an apparent increase in the serum urea, uric acid and creatinine; diagnostic of renal damage was normalized by sulphated polysaccharides co-administration. Sulphated polysaccharides treatment showed an effectual role in counteracting the free radical toxicity by bringing about a significant decrease in peroxidative levels and increase in antioxidant status. These observations emphasize the antioxidant property of sulphated polysaccharides and its cytoprotective action against CsA induced nephrotoxicity.

Effect of oxypurinol on cyclosporine toxicity in cultured EA, LLC-PK1 and MDCK cells

It has been proposed that cyclosporin (CsA) toxicity may in part be due to the action of oxygen-based free radicals. We compared the response of cultured endothelial (EA) and epithelial (LLC-PK1 and MDCK) cells to CsA, 250 or 1000 ng/mL for 24 or 72 h, with or without the xanthine oxidase inhibitor oxypurinol (Oxy), 10 mg/mL. CsA-induced alterations were seen on phase contrast and electron microscopy. In EA cells, swollen mitochondria and large cytoplasmic vacuoles surrounded by a thin membrane containing ribosomes were present at the periphery of the cell. In LLC-PK1 cells no vacuoles were present while in MDCK cells, the vacuoles were smaller and more centrally located. In both epithelial cell lines, mitochondria were distorted with loss of cristae. In all three cell lines, CsA depressed cell counts and decreased 3H-thymidine incorporation. Also, LDH release was accelerated. The addition of Oxy minimized the morphologic effect of CsA on all three cell lines with the effect more apparent in EA cells. The CsA-induced reduction of cell replication and increase in LDH release were also attenuated by Oxy. These results support the notion that the peroxidative properties of CsA may be responsible in part for CsA-induced nephrotoxicity.