Biochemical effects of oleuropein in gentamicin-induced nephrotoxicity in rats

BACKGROUND: Oleuropein is a natural antioxidant and scavenging free radicals. In the present study, we examined effect of oleuropein on the paraoxonase ۱ (PON۱) activity, lipid peroxidation, lipid profile, atherogenic indexes, and relationship of PON۱ activity by high-density lipoprotein-cholesterol (HDL-C) and atherogenic indices in gentamicin (GM)-induced nephrotoxicity in rats. METHODS: This is a lab trial study in Khorramabad, Lorestan province of Iran (۲۰۱۳). ۳۰ Sprague-Dawley rats were divided into three groups to receive saline; GM, ۱۰۰ mg/kg/day; and GM plus oleuropein by ۱۵ mg/kg intraperitoneal daily, respectively. After ۱۲ days, animals were anesthetized, blood samples were also collected before killing to measure the levels of triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL), and very LDL (VLDL), HDL-C, atherogenic index, lipid peroxidation, and the activities of PON۱ of all groups were analyzed. Data were analyzed, and P < ۰.۰۵۰ was considered significant. RESULTS: 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 PON۱ in treated animals was (۶۲.۶۴ ± ۸.۶۸) that it was significantly higher than untreated animals (۴۷.۰۶ ± ۴.۱۰) (P = ۰.۰۴۷). The activity of PON۱ in the untreated nephrotoxic rats was significantly lower than that of control animals (۷۷.۸۴ ± ۹.۴۳) (P = ۰.۰۳۰). Furthermore, the activity of PON۱ correlated positively with HDL-C and negatively with AC, CRR ۱, and CRR ۲ in the treated group with oleuropein. CONCLUSION: This study showed that oleuropein improves PON۱ activity, lipid profile, and atherogenic index and can probably decrease the risk of cardiovascular death in nephrotoxic patients.