Effect of a high saturated fat and cholesterol diet supplemented with squalene or beta-sitosterol on lipoprotein profile in F1B hamsters

The effects of a high saturated fat and cholesterol diet, supplemented with squalene or beta-sitosterol, on plasma lipoprotein levels in animals were evaluated. Thirty-six male adult F1B hamsters were fed for four weeks on a diet rich in saturated fatty acids composed of 90% chow diet, 10% coconut oil and 0.05% cholesterol. Subsequently, the animals were randomly assigned to three different diet groups (12 animals per group) for four weeks. Group 1 animals consumed the same high-fat diet; group 2 the high-fat diet supplemented with 1% squalene, and group 3 the high-fat diet supplemented with 0.5% beta-sitosterol. Results show that squalene does not modify plasma lipoprotein levels. However, in animals that consumed the diet high in saturated fat and cholesterol supplemented with beta-sitosterol, plasma levels of total cholesterol, triglycerides and the total cholesterol/HDL-cholesterol ratio decreased by 33%, 49% and 48%, respectively. This reduction in total cholesterol was probably associated with decreased absorption of cholesterol and lower incorporation in chylomicrons and VLDL + IDL. However, cholesterol absorption per se was not measured in this experiment. Plasma triglyceride levels decreased in all lipoprotein fractions. In conclusion, under our experimental conditions, beta-sitosterol exerts a hypocholesterolemic and hypotriglyceridemic effect in experimental animals. However, the addition of squalene (1%) to this diet produces no effect on plasma lipoprotein levels. (C) 2000 Elsevier Science Inc.