The effects of isoflavones on serum lipids in C57BL/6J mice

Soy lowers cholesterol levels which corresponds to a decrease in cardiovascular disease risk. However, the mechanisms of this effect as well as the components of soy that cause this effect are a source of controversy. It is also unknown whether soy protein containing endogenous isoflavones would have the same effect as soy protein containing low isoflavones with isoflavones supplemented back to the protein source. We have previously shown in a cell culture model that the isoflavones increase the processing of the Sterol Regulatory Element Binding Proteins (SREBPs) and the expression SREBP‐regulated genes. In this study male and female C57BL/6J mice were fed for 2 days, 10 days or 6 weeks, an atherogenic diet containing soy protein with low endogenous amounts of isoflavones, soy protein with isoflavone supplementation or soy protein with high amounts of endogenous isoflavones. Cholesterol and/or atorvastatin were also added to the diets. Upon sacrifice serum and liver tissue lipids were analyzed. The results of the serum lipids are shown here. The expression levels of the SREBP‐regulated gene, the LDL receptor and HMG CoA reductase were investigated by PCR. Funding NIH 1R15HL096463‐01