Comparative study of the effects of replacing casein by soybean flour on the cholesterol Metabolism of rats fed with normocaloric and hypercaloric diets

GABRIELA S. RAZZETO,VIVIANA . LUCERO LLPEZ, NORA L, ESCUDERO AND MARÍA S. GIMÉNEZ

Journal of Advances in Food Science & Technology

International Knowledge Press

Año: 2016

2454-4213

Although regular soy consumption is mainly in the whole grain form, most of the research on soybean has beenconducted on soy protein concentrate or isolate. Therefore, the aim of this investigation was to evaluate thepotential benefits of soybean flour on the cholesterol metabolism of rats previously fed with normocaloric andhypercaloric casein-based diets. The study was performed with two groups, one fed with control diet (AIN-93)and one with hypercaloric diet, for 9 weeks. Each group was then divided into two subgroups, and casein wasreplaced by soybean flour in one of them, for 6 weeks (subgroups: control casein (CC), control soy (CS),hypercaloric casein (HC) and hypercaloric soy (HS)). We measured total cholesterol (Total-C) and high densitylipoprotein cholesterol (HDL-C) in serum by the enzymatic method; Low-density lipoprotein (LDL-C) usingthe Friedewald formula and very low-density lipoprotein-cholesterol (VLDL-C) by TG/5. In liver, wemeasured: total lipids by dry weight; total cholesterol (TC), free cholesterol (FC) and esterified cholesterol(EC) by spectrophotometry; and the expression of 3-hydroxy-3-methylglutaryl-Coenzyme A reductase (HMGCoAR),low-density lipoprotein receptor (LDLR), sterol regulatory element binding protein 2 (SREBP2),cholesterol 7 α-hydroxylase (CYP7A1) and apolipoprotein B (APOB) by reverse transcription polymerasechain reaction (RT-PCR). When comparing CS vs. CC, a positive effect of soybean flour was found bydecreasing the Total-C (P