Hypolipidemic effects of soy yogurt fortified with antioxidant rich vegetable oil on albino mice fed high cholesterol diet

Abstract

Soy yogurt containing specific antioxidants such as oryzanol by adding rice bran oil and specific lignans such as sesamin and sesamolin from sesame oil that exhibited lipid peroxidation was developed with the use of mixtures of yogurt starter culture and edible soy flour (meal) instead of using whole soy bean seed. The aim of this study was to investigate the cholesterol-lowering properties of rice bran oil and sesame oil containing soy yogurt. In order to examine the effects on hypercholesterolemia in Swiss albino male mice with administration of 1.25% cholesterol, soy yogurt (control) and rice bran oil-sesame oil incorporated soy yogurt with doses of 3.0 and 2.5 g kg-1 body weight was given orally daily for 8 weeks respectively. Changes in the content of functional components (antioxidants, lipid profile and proximate composition) and microbiological characteristics (microbial cell counts) of soy yogurt (control) and rice bran oil-sesame oil incorporated soy yogurt were also examined. In hypercholesterolemia, mice fed with rice bran oil-sesame oil incorporated soy yogurt showed a favourable effect in reducing blood cholesterol, triglycerides and LDL-c cholesterol, caused a significant decrease in lowering the atherogenic index when compared with regular chow diet only. In hypercholesterolemia, consumption of bio-fortified soy yogurt significantly improved the HDL-c in serum, super oxide dismutase and catalase level in liver homogenate and significantly declined the serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, acid phosphatase and gamma glutamyl transferase activities. Treatment with rice bran oil-sesame oil incorporated soy yogurt with yogurt starter culture ameliorates lipid peroxidation in liver. The results indicated that the addition of oil(s) improved physicochemical and microbiological characteristics of soy yogurt and enabled a novel technological approach for making antioxidants and lignans fortified soy yogurt which had anti-atherogenic, hypolipidemic and improved liver function effects.