The Effect of Olive Leaf Extract and α-Tocopherol on Nephroprotective Activity in Rats

The present study aimed to evaluate the nephroprotective effects of different doses of aqueous extract of olive leaf (OLE), vitamin E and their combination on gentamicin induced nephrotoxicity in albino rats. 54 adult healthy male rats were divided into nine groups comprising 6 animals each. Group 1 served as normal control group. All other groups (group 2 to group 9) were administered gentamicin sulphate (GS) intraperitoneal at dose 70 mg/kg body weight for 4 week daily. Group 3, 4, 5 and 6 received olive leaf extracts at doses 20, 40, 80 and 160 mg/Kg/oral respectively. Group 7 received vitamin E 250 mg/Kg, whereas group 8 and 9 received vitamin E and olive leaf extracts (20 mg/Kg/oral and 40 mg/Kg/oral respectively). All the treatments were continued for 30 days. The results of the study indicated that olive leaf significantly protected the nephrotoxicity induced by Gentamisin sulphate. Serum creatinine, urea, malonaldhyde levels significantly increased as a result of nephrotoxicity in group 2. The renal antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities were decreased; level of malondialdehyde (MDA) was elevated in group 2. Remarkably treatment with olive leaf extracts and vitamin E increased levels of antioxidant enzymes and decrease levels of MDA, serum creatinine and urea in all treated groups. Sodium levels were significantly reduced and elevated potassium levels in G2. According to the biochemical findings, were supported by histopathological evidences, administration of olive leaf extracts with vit. E more was effective protection than their individual dose. Administration of olive leaf extract (20 mg/kg, 40 mg/kg) plus vitamin E (250 mg/kg) indicated better protection against GS-induced nephrotoxicity. This study concluded that olive leaf acts in the kidney as a potent scavenger of free radicals to prevent the toxic effects of GS both in the biochemical and histopathological parameters. Germinated barley extract with OLE (20 mg, 40 mg) + vitamin E was showed good antioxidant properties.