Effects of short-term ingestion of different sitosterol esters on plasma lipids, faecal steroids, fats and proteins in rats

Sterol and sterol esters are naturally occurring antioxidants available mainly from vegetable oils. The modification in compositions of these natural antioxidants leads to the production of nutraceuticals. The purpose of the present study was to compare the effects of different n-3 fatty acid rich sitosterol esters on plasma lipid lowering, faecal fat and steroid excretion. The difference in efficacy between the two esters (EPA-DHA and ALA rich sitosterol ester) in rats fed with a high cholesterol diet was also observed. Thirty six rats were taken for the study and were divided into 6 groups : control group, hypercholesterolemic group, EPA-DHA rich sitosterol ester treated and ALA rich sitosterol ester treated group with two different doses (0.25 g/kg body wt/day, 0.5 g/kg body wt/day). The sterol esters were gavaged to the rats daily for 4 weeks. The plasma total cholesterol, non-HDL cholesterol and triglyceride levels were elevated in hypercholesterolemic group but was significantly lowered by both the sterol esters. The high dose of EPA-DHA rich sterol ester showed the best result. Faecal cholesterol and total lipid excretion increased in the treated groups than the hypercholesterolemic one. Faecal protein excretion decreased in the treated groups in comparison to the hypercholesterolemic one which revealed that protein was utilized better in the bodies in presence of sterol esters. In conclusion EPA-DHA rich sterol ester produced better nutraceutical properties in comparison to ALA rich sterol ester.