Simvastatin Does Not Affect Nitric Oxide Generation Increased by Sesame Oil in Obese Zucker Rats

Current treatments for cardiovascular and obesity-associated diseases, such as statin therapy, may be associated with several side effects. Products from food sources with polyphenolic compounds may represent promising agents in the treatment of cardiovascular and metabolic diseases with minimal side effects. Thus, we aimed to study the effect of sesame oil and simvastatin treatment on plasma lipid profile, nitric oxide generation, and oxidative load in obese Zucker rats. 12-week-old male Zucker rats were divided into the control and sesame oil- (1.25 ml/kg/day) treated Zucker lean groups, the control and sesame oil (1.25 ml/kg/day), or simvastatin (15 mg/kg/day) together with sesame oil-treated Zucker fa/fa groups, n=6 in each group. The treatment lasted for 6 weeks. Sesame oil composition and plasma lipid profile were analyzed. Nitric oxide synthase (NOS) activity, endothelial NOS (eNOS), phosphorylated eNOS, and inducible NOS (iNOS) protein expressions were determined in the left ventricle and aorta. Oxidative load, measured as conjugated diene (CD) and thiobarbituric acid reactive substance (TBARS) concentrations, was detected in the liver. Neither sesame oil nor cotreatment with simvastatin affected plasma lipid profile in Zucker fa/fa rats. Sesame oil and similarly cotreatment with simvastatin markedly increased NOS activity and phosphorylated eNOS protein expressions in the left ventricle and aorta of Zucker fa/fa rats. There were no changes in eNOS and iNOS protein expressions within the groups and tissues investigated. Hepatic CD concentration was higher in Zucker fa/fa comparing Zucker lean rats, and sesame oil treatment decreased it significantly. Interestingly, this decrease was not seen after cotreatment with simvastatin. In conclusion, phosphorylation of eNOS and decreased oxidative load may significantly contribute to increase in total NOS activity with potential beneficial properties. Interestingly, simvastatin did not affect NO generation already increased by sesame oil in obese Zucker rats.