The effect of quercetin, a bioflavonoid on ischemia/reperfusion induced renal injury in rats.

There is increasing evidence to suggest that toxic oxygen radicals play a role in the pathogenesis of ischemia/reperfusion (I/R) injury in the kidney. This study was designed to investigate the effects of quercetin (Qr), a bioflavonoid in ischemia-reperfusion induced renal failure in rats. The effect of quercetin against the damage inflicted by reactive oxygen species (ROS) during renal I/R was investigated in Sprague-Dawley rats using histopathological and biochemical parameters. In one set of experiments, animals were unilaterally nephrectomized and subjected to 45 min of left renal pedicle occlusion, and in another set both renal pedicles were occluded for 45 min followed by 24 h of reperfusion. Quercetin (2 mg/kg, 30 mg/kg, i.p. and 100 mg/kg, p.o.) was administered 2 h prior to ischemia. At the end of the reperfusion period, rats were sacrificed. Thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH) levels, glutathione reductase (GR), catalase (CAT), and superoxide dismutase (SOD) activities were determined in renal tissue. Serum creatinine and blood urea nitrogen (BUN) concentrations were measured for the evaluation of renal function. Ischemic control animals demonstrated severe deterioration of renal function, renal morphology and a significant renal oxidative stress. Pretreatment of animals with quercetin (2 mg/kg and 30 mg/kg, i.p.) markedly attenuated renal dysfunction, morphological alterations, reduced elevated TBARS levels and restored the depleted renal antioxidant enzymes, whereas the (100 mg/kg, p.o.) dose of quercetin failed to revert the renal I/R induced changes. The findings imply that ROS play a causal role in I/R induced renal injury and quercetin exerts protective and deleterious effects in the kidney, depending upon the dose.