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-β1), 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-β1 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.

The hydroglycolic (HG) extract from 70% propylene glycol (PG) extraction of myrobalan fruits showed the most appreciable antioxidant efficiency towards 1,1-diphenyl-2-picrylhydrazyl (DPPH) in comparison to the extracts from 30, 50, 70 and 100% ethyl alcohol (EA), and 30, 50 and 100% PG . Its total polyphenols were also higher than others. The additional analysis of antioxidant power revealed that this HG extract was able to counteract the induced oxidation caused by hydrogen peroxide (H(2) O(2) ) and 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH). The quantification for the antioxidant capacity of the extract showed it was equivalent to 93.78 mg of 6-hydroxy-2,5,7,8-tetramethychroman-2-carboxylic acid (Trolox) g(-1) by 2,2'-azino-bis(3-ethylbenzthiazoline-6-suphonic acid) diammonium (ABTS) assay, and was 140.17 mg ascorbic acid (AA) equivalent g(-1) and 107.50 mg Trolox equivalent g(-1) by photochemiluminescence (PCL) assay. The incorporation of the HG myrobalan extract into lotion and sunscreen lotion rendered these products to provide the similar antioxidant power as the extract alone.