Effects of highly purified sardine proteins on lipid peroxidation and reverse cholesterol transport in rats fed a cholesterol-rich diet

The effect of highly purified sardine proteins was compared with that of casein on serum and lipoproteins lipid peroxidation and reverse cholesterol transport. Lecithin:cholesterol acyltransferase (LCAT) activity, high density lipoproteins (HDL₂ and HDL₃) composition and serum lipid and lipoproteins peroxidation were determined in rats fed a cholesterol-rich diet. Hypercholesterolemic rats were divided into two groups fed diets enriched with cholesterol and containing 20% of highly purified sardine proteins (SPc) or casein (CASc) for 28 days. A control group was fed a standard diet (CAS). Compared with CAS and CASc, the thiobarbituric acid reactive substances (TBARS) concentrations of low density lipoprotein (LDL)–HDL₁ in SPc were 3.5- and 1.7-fold higher compared with casein diets. TBARS in HDL₂ and HDL₃ were, respectively, 2.3- and 1.6-fold lower in SPc compared with CASc. In SPc group, LCAT activity was higher compared to CASc and CAS (P < 0.05). Purified sardine proteins had no beneficial effects on LDL-cholesterol and lipid peroxidation. However, they reduced HDL oxidation and improved reverse cholesterol transport, in the hypercholesterolemic rat.