Alpha-Lipoic Acid Attenuates Renal Injury in Rats with Obstructive Nephropathy

This study was established to determine the possible protective effects of alpha-lipoic acid (ALA), a powerful antioxidant, on renal injury in obstructive nephropathy. Male Sprague-Dawley rats were assigned into sham-operated unilateral ureteral obstruction (UUO) and UUO treated with ALA groups. ALA 60 mg/kg was injected intraperitoneally 2 days before UUO induction and continued afterward for 7 days. Renal function, oxidative stress markers, nitric oxide, transforming growth factor-1 (TGF-beta 1), and histological changes were evaluated at the end of the experiment. Obstruction of the ureter resulted in renal dysfunction as indicated by significant increases in blood urea nitrogen and serum creatinine. Nonobstructed contralateral kidneys in all groups examined did not show any morphological or biochemical alterations. In untreated UUO group, the obstructed kidney developed marked hydronephrosis, leukocyte infiltration, and severe interstitial fibrosis. These functional and structural changes were associated with significant increases in tissue levels of malondialdehyde, nitric oxide, and TGF-beta 1 but decreases in reduced glutathione and total antioxidant capacity. Pretreatment with ALA significantly minimized all the changes elicited by ureteral obstruction. These findings demonstrate that ALA supplementation attenuates renal injury in rats with obstructive nephropathy and further suggest that oxidative stress inhibition is likely to be involved in the beneficial effects of this compound.