Fermented Soy Milk On Serum Lipids In High Fat Diet On The Rct Pathway Regulating Role

ObjectivObjective:In this study, male SD rats were chosen and fed on fermented soy milk. The experiment wasdesigned to study the effect of fermented soymilk on surem lipid-lowering in rats induced byhigh fat diets. Also the possible mechanism of reverse cholesterol transport(RCT)wasexplored.Methods:Male Sprague-Dawley rats (n=32) were acclimatized for 1 week before commencement of thetrial. They were divided into control group, hyperlipidemia group, soymilk group and fermentedsoymilk group by randomized block grouping according to the initial serum cholesterol and bodyweight. The animals were housed individually. Feed and given to the appropriate treatment,therats were killed 8weeks later and their livers were weighed.Total cholesterol (TC), triglyceride(TG), high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol(LDL-C), indexes of serum were detected with commercial kits.The expression of mRNA ofABCA1, LCAT, SR-BI in liver of rats were detected by means of RT-PCR.Results:1.The body weight of the rats rose with the time, but it in high fat control group was significantlylower than that of normal control group(P<0.05)at the end of the experiment; The ratio of liverindex(liver/body weight)in high fat control group was higher than that of normal control groupsignificantly; Compared with the high fat control group, the ratio of liver/body weight liver indexin soymilk group and fermented soymilk group was lower significantly(P<0.01), but it wassignificantly higher than that of normal control group(P<0.01).2.After four weeks, the level of serum total cholesterol in high fat control group was higher thanthat of normal control group (P<0.05); At the end of the sixth week, the level of serum totalcholesterol in the two intervention groups was lower than it in high fat control group(P<0.05),the fermented soymilk group was decreased significantly(P<0.01).3.There were no significant differences in serum triglyceride level among the experimentgroups(P>0.05) at the end of the first sixth week. At the end of the experiment, serum trigly -ceride level of the high fat control group and two intervention groups was lower than it in normalcontrol group(P<0.05).4.There were no significant differences in serum high density lipoprotein-cholesterol levelamong the experiment groups(P>0.05) until the end of the eighth week.Then the level of serumhigh density lipoprotein-cholesterol was higher than those in normal control group and twointervention groups(P<0.05). 5.From the end of the fourth week to the end of the experiment, The levels of serum low densitylipoprotein-cholesterol in high fat control group was higher than the normal control group andfermented soymilk group (P<0.05), the fermented soymilk group was decreased significantly(P<0.01); Compared with the high fat control group, serum low density lipoprotein cholesterol insoymilk group decreased, but the difference was not significant (P>0.05) at the end of the eighthweek.6.There were ABCA1, LCAT, SR-B? expression in Rat liver.High-fat diet decreased rat liverABCA1, LCAT, SR-B? mRNA expression;soymilk markedly enhanced the SR-BI mRNAexpression of SR-BI in high-fat diet rat liver, and it had no effect on ABCA1 and LCAT;Fermented soymilk enhanced ABCA1 and SR-B? mRNA expression in rat liver to close thenormal levels. The mRNA expression level of LCAT mRNA in liver in fermented soymilk groupwas higher than it of high fat control group(P<0.05) but was lower than the normal controlgroup(P<0.05).Conclusion:Fermented soymilk could regulate plasma lipid of rats with high fat diet effectively. It decreasedthe level of serum total cholesterol and low density lipoprotein-cholesterol; increased the mRNAexpression level of ABCA1 and SR-B? mRNA and played an important role in promotion ofreverse cholesterol transport(RCT).