The effect of oleuropein on unilateral ureteral obstruction induced-kidney injury in rats: the role of oxidative stress, inflammation and apoptosis.

Unilateral ureteral obstruction (UUO) induces kidney injury. Oleuropein as a major compound of olive leaves modulates the inflammatory parameters and decreases oxidative stress. Accordingly, we evaluate the renoprotective effect of oleuropein against 3-day UUO rats. Forty rats were randomly divided into five groups (n = 8) including control, UUO and UUO + oleuropein groups (50, 100 and 200 mg/kg). UUO model was induced by left ureter ligation and continued for 3-day. Rats were treated synchronic daily for 3-day, then mean arterial pressure (MAP), renal perfusion pressure (RPP), renal blood flow (RBF), serum creatinine level, and also superoxide dismutase (SOD), glutathione peroxidase (GPx) activity levels and malondialdehyde (MDA) concentration (in the obstructed kidney) were measured. The western blotting method was applied to evaluate the Bax, Bcl-2, cleaved caspase-3 and TNF-α proteins expression level. The hematoxylin and eosin method was applied to evaluate the kidney tissue damage score (KTDS). UUO significantly increased RVR, KTDS, and MDA, cleaved caspase-3, Bax, serum creatinine and TNF-α protein levels (P < 0.05), and also significantly decreased RBF, SOD, and GPx and Bcl-2 protein expression levels (P < 0.001) in the obstructed kidney and oleuropein (200 mg/kg) significantly ameliorated the changes induced by UUO. Our findings showed that oleuropein has a renoprotective effect against 3-day UUO. The mechanisms underlying the observed effects may be related to its antioxidative stress, anti-apoptotic, and anti-inflammatory effects.