α-tocopherol (vitamin-E) ameliorates ferric nitrilotriacetate (Fe-NTA)-dependent renal proliferative response and toxicity:: diminution of oxidative stress

Ferric nitrilotriacetate (Fe-NTA) is a potent nephrotoxic agent. In this communication, we show the modulatory effect of DL-alpha-tocopherol (Vitamin-E) on ferric nitrilotriacetate (Fe-NTA)-induced renal oxidative stress, toxicity and hyperproliferative response in rats. Fe-NTA-treatment enhances the susceptibility of renal microsomal membrane for iron-ascorbate-induced lipid peroxidation and hydrogen peroxide generation which are accompanied by a decrease in the activities of renal antioxidant enzymes, catalase, glutathione peroxidase, glutathione reductase and glutathione-S-transferase and depletion in the level of renal glutathione. Parallel to these changes, a sharp increase in blood urea nitrogen and serum creatinine has been observed. In addition, Fe-NTA-treatment also enhances renal ornithine decarboxylase activity (ODC) and increases [H-3]thymidine incorporation in renal DNA. Prophylactic treatment of animals with Vit.E daily for 1 week prior to the administration of Fe-NTA resulted in the diminution of Fe-NTA-mediated damage. Enhanced susceptibility of renal microsomal membrane for lipid peroxidation induced by iron-ascorbate and hydrogen peroxide generation were significantly reduced (P<0.05). In addition, the depleted level of glutathione and inhibited activities of antioxidant enzymes recovered to significant levels (P<0.05). Similarly, the enhanced blood urea nitrogen and serum creatinine levels which are indicative of renal injury showed a reduction of about 50% at a higher dose of Vit.E. The pretreatment of rats with Vit.E reduced the Fe-NTA-mediated induction in ODC activity and enhancement in [H-3]thymidine incorporation in DNA. The protective effect of Vit.E was dose dependent. In summary, our data suggest that Vit.E is an effective chemopreventive agent in kidney and may suppress Fe-NTA-induced renal toxicity.