Abstract
Olive leaf extract (OLE) has potential health benefits and protects against cytotoxicity in different organs. However, nothing has yet been reported on its potential to prevent cyclophosphamide (CP)-induced nephrotoxicity. This study investigated the possible protective effect of OLE on CP-induced kidney injury in rats, focusing on oxidative stress, inflammation, apoptosis and Nrf2/ARE/HO-1 signaling. Rats received 100 or 200 mg/kg body weight OLE for 15 days and a single injection of 150 mg/kg CP at day 16. CP induced kidney injury evidenced by the significantly increased serum creatinine and urea, and histopathological alterations, including glomerular atrophy, interstitial hemorrhage, dilated urinary space and necrosis. CP-induced rats exhibited increased kidney lipid peroxidation, protein carbonyl, nitric oxide (NO) and pro-inflammatory cytokines, and up-regulated NF-kappa B, Bax, cytochrome c and caspase-3. OLE ameliorated kidney function markers and prevented CP-induced tissue damage. In addition, OLE significantly prevented oxidative stress, inflammation and apoptosis by enhancing the antioxidant defenses and Bcl-2 expression, and suppressing the pro-inflammatory and pro-apoptotic markers NF-kappa B, Bax, cytochrome c and caspase-3. OLE up-regulated Nrf2, HO-1 and NQO-1 expression in the kidney of CP-induced rats. In conclusion, OLE has a substantial protective role against CP-induced nephrotoxicity in rats by up-regulating the Nrf2/ARE/HO-1 signaling, enhancing the antioxidant activity and attenuating inflammation and apoptosis.