RESUMEN
INTRODUCTION: The effects of ezetimibe and atorvastatin on serum lipid profile and oxidant-antioxidant system were investigated in rats. METHODS: Seventy-two Sprague-Dawley rats were assigned to 6 groups. Group 1 was fed with standard rat chow. Group 2 and the other 4 groups were fed with a high-cholesterol diet: 10 mg/kg/d atorvastatin to group 3; 1 mg/kg/d atorvastatin to group 4; 10 mg/kg/d atorvastatin and 1 mg/kg/d ezetimibe to group 5; and 1 mg/kg/d ezetimibe to group 6. After 3 months, serum total, low-density lipoprotein, high-density lipoprotein cholesterol, and triglyceride levels, and the activities of malondialdehyde, glutathione peroxidase, and superoxide dismutase were measured in the plasma. In addition, the left anterior descending and femoral arteries were examined histopathologically. RESULTS: Serum total, low-density lipoprotein cholesterol, and triglyceride levels decreased slightly in group 3. However, administration of 1 mg/kg/d atorvastatin or 1 mg/kg/d ezetimibe did not significantly change lipid parameters. Plasma malondialdehyde levels slightly increased in group 2 compared with controls and decreased compared with both the atorvastatin regimens. However, malondialdehyde levels increased with the addition of ezetimibe to atorvastatin. Only the administration of ezetimibe significantly elevated the levels of malondialdehyde. Glutathione peroxidase and superoxide dismutase levels were also found to be significantly reduced in the groups receiving ezetimibe when compared with atorvastatin groups. CONCLUSIONS: Atorvastatin has a beneficial effect on oxidative stress in rats fed with high-cholesterol diet. A combination of ezetimibe with atorvastatin diminishes the beneficial effects of atorvastatin. Conversely, the sole administration of ezetimibe increases oxidative stress.