Hemin Versus Erythropoietin: Possible Role in Nrf2/HO-1 Signaling Pathway in Rats with Nephrotoxicity

BACKGROUND AND AIM:Gentamycin-induced nephrotoxicity is related to stimulation of oxidative stress and inflammatory cascades leading to apoptotic renal damage. Heme oxygenase-1 (HO-1) induction considered to be an adaptive response against oxidative tissue damage. Our study aimed to investigate the possible nephroprotective role of HO-1 inducers (hemin and erythropoietin (EPO)) and elucidate their potential underlying molecular mechanisms by assessing their antioxidant, anti-apoptotic, and anti-inflammatory properties.METHODS:Kidney function markers (urea and creatinine), lipid peroxidation and antioxidant markers (MDA and GPx), inflammation and apoptotic markers (IL-6 and Bcl-2), and the relative gene expression levels of Nrf2 and HO-1 were assessed. Histopathological changes of the kidney were examined.RESULTS:Nephrotoxic rats pretreated with hemin showed significant decrease in serum level of urea, creatinine, and MDA, compared to non-treated group. The kidney tissues also showed significant elevation of Bcl2 level, but significant decrease of IL-6, compared to non-treated group. Moreover, hemin pre-treatment significantly upregulated gene expression of Nrf2 and HO-1 in kidney tissue to near the normal control group. On the other hand, pretreatment with EPO showed significant upregulation of HO-1 gene expression but didn't show significant difference in Nrf2 gene expression compared to control group. The histopathological examination of kidney supported the biochemical results.CONCLUSION:The current results proved that hemin rather than EPO, showed reno-protective effects in rats, which was mediated by activation of Nrf2 signaling pathway. This could be also attributed to the observed anti-inflammatory, antioxidant, and anti-apoptotic properties of hemin. In this regard, EPO showed lower potency.