Effect of soybean peptide intake on catabolism of cholesterol in rats

  Objective   To investigate the effects of dietary soybean pr otein intake on the concentration of serum lipids in hypercholesterolemic rats and to study the mechanisms of them.

  Methods   Following 28 days of inducing the hyperc-holesterolemia model successfully, rats were fed a purified diet containing either casein or soybean protein.After the experimental diets had been fed for 56 days, fasting animals were killed.

  Results   Comparing with the rats in casein group, the total cholesterol(TC), trig lyceride(TG)and apolipoprotein B(apoB)in soybean protein group were significantly low(P < 0.05).The concentrations of fecal excretion of bile acids were higher in the rats of soybean protein group(P < 0.05).Whereas, the changes of high density lipoprotein cholesterol, apolipopr otein AI(apoA-Ⅰ)were not significant in these rats.The levels of 3-hydroxy-3-methylglutaryl coenzyme A(HMG-CoA)reductase mRNAand low density lipoprotein receptor mRNA in soybean protein rats were significantly high.

  Conclusion   Dietary soybean protein intake may lower TC.Further resear ches are needed for study.