protective effect of antioxidants on renal ischemia-reperfusion injury in the rat

Renal ischemia-reperfusion [I/R] is of clinical interest because of its role in renal failure and also in renal graft rejection. There is increasing evidence to suggest that reactive oxygen species [ROS] play a role in the pathogenesis of I/R injury in the kidney. This study was designed to investigate the protective effect of some dietary antioxidants [garlic, vitamin E or vitamin A + Se [+2]] against the damage inflicted by [ROS] during renal I/R. Five groups of male albino rats were used in this study each composed of 10 rats. Group I: Sham-operated control group. Group II: I/R group [not treated] unilaterally nephrectomized after subjection of the left renal pedicle to 60 minutes of nontraumatic occlusion followed by 24 hours of reperfusion. Group III: the same procedure as group II but animals were preconditioned by adding garlic powder to their diet 80 mg kg[-1] daily for one month. Group IV: like group III but vitamin E [6.5 mg kg[-1]/d for one month] was supplemented to diet. Group V: like the two previous groups III and IV but vitamin A [7.9 mg/kg[-1]] and Se[+2] [50 microg/kg[-1]] were added daily to the rats' diet for one month. At the end of the reperfusion period, the rats were sacrificed. Malondialdehyde [MDA], Reduced glutathione [GSH] concentrations, superoxide dismutase [SOD], glutathione reductase and glutathione peroxidase enzymatic activities were determined in plasma and kidney homogenates of all groups. Serum creatinine and blood urea concentrations, were measured, for the evaluation of renal function. Also Na[+]-K[+]-ATPase was determined in kidney homogenates. Ischemic reperfused [l/R] animals demonstrated severe detonation of renal function and a significant renal oxidative stress. Pretreatment of animals with garlic, vitamin E or vitamin A + Se [2+] markedly attenuated renal dysfunction and oxidative stress as manifested by reducing blood urea, serum creatinine, MDA and restored depleted renal antioxidant enzymes. Na[+]-K[+]-ATPase activity, which was decreased in the I/R group, increased in the animals preconditioned with vitamins E and A + Se[2+]. From this it can be concluded that ROS play a causal role in I/R induced renal injury and supplementing the animals with garlic and/or other dietary antioxidants exerts protective effects. Therefore, it is recommended to supply patients expected to suffer from I/R renal injury with these antioxidants