Abstract: Objective To investigate the lipid regulating effects of soybean isoflavone extracts on genetic engineering mice with both hypercholesterolemia and hypertriglyceridemia. Method Under the western-type food conditioning，10(♂5，♀5) adult C57BL/6 mice were used as control, 40 adult mice with both aopE and LPL gene deficiency （apoE^-/-/LPL^+/-) were divided into four groups, i.e., the group of animal models of hyperlipidemia，three groups of intragastric administration respectively with dose of 200 mg·kg^-1·d^-1 of soybean isoflavone extracts，0.5 mg·kg^-1 of nylestrodial per week and 20 mg·kg^-1·d^-1 of lovastatin. After four weeks consecutive administration, concentration of serum total cholesterol, triacylglycerol，HDL cholesterol，LDL cholesterol and glucose were determined. Result Compared with the control mice of C57BL/6，the diet induced models of hyperlipidemia had a remarkable increase in triglyceride，total and LDL cholesterol(P<0.01). Compared with models of hyperlipidemia, administration of soybean isoflavones had a favorable reduction in triglyceride (p<0.05) and a 9.3% increase in HDL cholesterol, while administration of nylestrodial and lovastatin had 13.5% and 8.7% reduction in HDL cholesterol respectively. Probably due to the greatly increased total and LDL cholesterol in apoE^-/-/LPL^+/- mice, there is no effects of soybean isoflavone, nylestrodial and lovastatin on both the variables. Conclusion Soybean isoflavones had evident favorable lipid regulating effects.

Key words: Soybean isoflavones, apoE gene, LPL gene, Gene knockout, apoE and LPL gene deficient (apoE^-/-LPL^+/_) mice, Blood lipid