The Protective Effect Of Phytosterol (PSE) On High Fat Diet Induced Aorta Ageing Of Rats And Its Mechanism

Objective: The purpose of this study is to explore the protective effect of phytosterol ester on aortic aging in aged rats,and explore the mechanism of this effect,provide evidence for the development and application of PSE.Methods: 42 12-month old female SD rats were randomly divided into three groups: control group,model group and PSE intervening group.During the experiment,rats in control group,model group and PSE intervening group were treated with basic feed,high fat diet(HFD)and HFD with 2% PSE(w/w)respectively for 6 months.The levels of lipoprotein in plasma and liver were measured.Morphological changes of aorta were observed by HE and Masson staining,level of AGEs in plasma were detected.The expression of LXR?,CYP7A1,ABCA1,HMGCoA,FXR,SREBP-1c,PPAR? mRNA in liver and the expression of SIRT1 and PPAR? mRNA in vascular tissue were determined by real time PCR.The the expression of SIRT1 and PPAR? protein in vascular were determined by Western blot.Results: Results revealed that PSE significantly lowered plasma TC,LDL-C,increased plasma HDL-C level(P<0.05),had no effect on plasma TG level(P>0.05),and improved the thickening of intima and media of aging aorta,decreased the migration of vascular smooth muscle cell(VSMC)and the amount of VSMC and collagen fiber(CF)in aorta(P<0.05).PSE significantly reduced the contents of AGEs in plasma(P<0.05).PSE had no effect on the mRNA level of LXR?,HMG-CoA,ABCA1,SREBP-1c and FXR in livers,but PSE decreased mRNA CYP7A1 and PPAR?.What's more,PSE down-regulated PPAR? and up-regulated SIRT1 in aorta.Conclusion: Results above suggest that PSE was able to ameliorate the senescence process in aorta through modulating lipid metabolism disorder,or activating SIRT1 in vascular tissue,or activating SIRT1 so that the expression of PPAR? was inhibited.