Antioxidant and protective effects of silymarin on ischemia and reperfusion injury in the kidney tissues of rats.
BACKGROUND
Renal ischemia/reperfusion (I/R) injury is a major cause of acute renal failure. Silymarin is extracted from Silybum marianum and Cynara cardunculus seeds and fruits. The aim of this study is to investigate whether silymarin administration prevents the damage induced by I/R in rat kidneys.


METHODS
Thirty male Wistar rats were randomly divided into five experimental groups (n = 6, each) as follows; control group, sham-operated group, I/R group, silymarin group, and I/R + silymarin group. In the I/R and I/R + silymarin groups, both renal arteries were occluded using nontraumatic microvascular clamps for 45 min. Then, at the end of 24 h of reperfusion, the animals were killed. Kidney function tests, the serum and tissue antioxidant enzymes and oxidant products were determined.


RESULTS
Animals that were subjected to I/R exhibited significant increase in serum urea, creatinine, and cystatin C levels compared with the rats treated with silymarin prior to the I/R process (P < 0.001). The serum enzymatic activities of superoxide dismutase and glutathione peroxidase significantly decreased in the I/R group; however, this reduction was significantly improved by the treatment with silymarin (P < 0.001 and P < 0.05, respectively). Renal I/R produced a significant increase in serum and tissue malondialdehyde, nitric oxide, and protein carbonyl as compared with controls. Treatment with silymarin resulted in significant reduction in these markers (P < 0.001).


CONCLUSIONS
Based on our findings, silymarin protects the kidneys against I/R injury. This finding may provide a basis for the development of novel therapeutic strategies for protection against the damages caused by I/R.
Turgut
Faruk
F
Department of Nephrology, Fatih University, School of Medicine, Hosdere cad no: 145, Y. Ayranci, 06540 Ankara, Turkey. turgutfaruk@yahoo.com
Bayrak
Omer
O
Catal
Ferhat
F
Bayrak
Reyhan
R
Atmaca
Ali Fuat
AF
Koc
Akif
A
Akbas
Ali
A
Akcay
Ali
A
Unal
Dogan
D
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology* / Q000627:therapeutic use; D055316:Cystatin C; D015891:Cystatins / Q000097:blood; D007668:Kidney / Q000098:blood supply / Q000187:drug effects* / Q000201:enzymology; D007684:Kidney Tubules / Q000473:pathology; D008297:Male; D009336:Necrosis; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology* / Q000627:therapeutic use; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000517:prevention & control*; D012838:Silymarin / Q000494:pharmacology* / Q000627:therapeutic use
D000975:Antioxidants; C525032:Cst3 protein, rat; D055316:Cystatin C; D015891:Cystatins; D010936:Plant Extracts; D012838:Silymarin