Effects of oleuropein on lipid peroxidation, lipid profile, atherogenic indices, and paraoxonase 1 status in gentamicin-induced nephrotoxicity in rats

Oleuropein is a natural antioxidant and scavenging free radicals. In the present study, we examined effect of oleuropein on paraoxonase 1 (PON1) activity, lipid peroxidation, lipid profile, atherogenic indices, and relationship of PON1 activity by high-density lipoprotein cholesterol (HDL-C) and atherogenic indices in gentamicin (GM)-induced nephrotoxicity in rats. This is a lab trial study in Khorramabad, Lorestan province of Iran (2013). Thirty Sprague-Dawley rats were divided into three groups to receive saline; GM, 100 mg/kg/d; and GM plus oleuropein by 15 mg/kg i.p daily, respectively. After 12 days, animals were anaesthetized, blood samples were also collected before killing to measure the levels of triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL), and very low-density lipoprotein (VLDL), HDL-C, atherogenic index, lipid peroxidation and the activities of PON1 of all groups were analyzed. Data were analyzed, and P < 0.050 was considered significant. Oleuropein significantly decreased lipid peroxidation, TG, TC, LDL, VLDL, atherogenic index, atherogenic coefficient (AC), and cardiac risk ratio (CRR). HDL-C level was significantly increased when treated with oleuropein. The activity of PON1 in treated animals was (62.64 ± 8.68) that it was significantly higher than untreated animals (47.06 ± 4.10) (P = 0.047). The activity of PON1 in the untreated nephrotoxic rats was significantly lower than that of control animals (77.84 ± 9.43) (P = 0.030). Furthermore, the activity of PON1 correlated positively with HDL-C and negatively with AC, CRR1, and CRR2 in the treated group with oleuropein. This study showed that oleuropein improves PON1 activity, lipid profile, and atherogenic index and can probably decrease the risk of cardiovascular death in nephrotoxic patients.