Study On The Regulatory Effect Of Rice Protein On Plasma HDL Level In Wistar Rat

In recent years,rice protein is being known as one of the plant protein which has higher nutritional values.Rice protein could be easily absorbed by human body.Meanwhile,it has the advantage of reducing cholesterol level for human body.However,there is still a lack of the studies on the effects of high density lipoprotein(HDL)which is one of the important transport materials in regulating cholesterol metabolism by rice protein.This research chose both of the growing rats and the adult rats as the study objects.Then we respectively added casein and rice protein into the animal diets.Under the different dietary conditions of cholesterol-free /cholesterol-enriched(add 1%)/oil-enriched(add 10%)diets,as well as the different ages,we studied the effects of which rice protein regulated the plasma HDL level and the liver gene expression level of lecithin cholesterol acyl transferase(LCAT),which is one of the important regulation factors of HDL metabolism as to the growing/adult rats.Under the cholesterol-free diet,compared to casein,on one hand,as to the growing rats,rice protein had no significant regulatory effects on the levels of plasma total cholesterol(TC),high density lipoprotein cholesterol(HDL-C),nonhigh density lipoprotein cholesterol(non-HDL-C)and the ratio of plasma HDLC/TC.However,rice protein had significant regulatory effects on the ratio of plasma non-HDL-C/HDL-C,as well as the liver gene expression level of LCAT;On the other hand,as to the adult rats,rice protein had significant regulatory effects on the level of plasma TC,HDL-C,non-HDL-C,and the ratio of plasma non-HDLC/HDL-C,as well as the liver gene expression level of LCAT.While there's no significant regulatory effects on the ratio of plasma HDL-C/TC.Under the cholesterol-enriched diet,compared to casein,rice protein showed significant regulatory effects on the level of plasma TC,HDL-C,non-HDL-C and the ratio of plasma non-HDL-C/HD as to both of the growing rats and the adult rats.However,rice protein had no significant reguthlatory effects on the liver gene expression level of LCAT.As for the ratio of plasma HDL-C/TC,rice protein showed opposite regulatory effects as to the growing/adult rats,and there were significant regulatory effects as to the adult rats.Under the oil-enriched diet,interestingly,as to both of the growing rats and the adult rats,rice protein performed significant regulatory effects on the level of plasma TC,HDL-C,non-HDL-C and the ratio of plasma non-HDL-C/HDL-C.Meanwhile,rice protein could slightly increase the liver gene expression level of LCAT.On the contrary,rice protein showed no significant regulat ory effects on the ratio of plasma HDL-C/TC.In conclusion,comparing different dietary conditions,rice protein showed the strongest HDL regulatory effects under the cholesterol-enriched diet.The next was the condition of oil-enriched diet,and the cholesterol-free diet was the weakest.Moreover,comparing different animal ages,rice protein showed stronger regulatory effects as to the adult rats than to the growing rats which suggested that rice protein could efficaciously reduce the increasing level of serum lipids and the higher risk of suffering from atherosclerosis along with the increasing age.