Effects Of Saponin From Tribulus Terrestris L. On Atherosclerotic Rats

Atherosclerosis is a kind of disease threatening the life and health of human being,and it is the pathological basis of cardiovascular and cerebrovacular diseases. So it is significant to investigate the mechanism and the treatment of AS to prevent and care cardiovascular and cerebrovacular diseases.Studies have shown that the gene expression of PPARsand ICAM-1,VCAM-1 have a great relations with the development of Atherosclerosis.STT has the antioxidant activity and efficacy of antiatherogensis,but the function mechanism has not been totally expounded yet.To investigate the effect of tribu saponin from Tribulus terrestris(STT)on the serum lipid levels of atherosclerotic rats,the changes of Aortic histomorphology and the changes of the gene expression of ICAM-1,VCAM-1 andPPARα,PPARγ,and study the function of anti-atherosclotic mechanism.The model rats of atherosclerosis were established by feeding with high cholesterol diet and injecting with vitamin D₃.The rats were divided into normal group,model group,and positive control group with Simvastatin and 3 groups with STT.Eight weeks late,body weight,liver weight,heart weight,renal weight,serum lipid levels of MDA,T-AOC,lipid and TG,TC in liver were measured;Aortic and liver histomorphology changes were observed by HE staining;Semi-quantitative PCR was used to detect ICAM-1,VCAM-1 and PPARα,PPARγgene expression in artery vessel.The change s of gene expression of ICAM-1,VCAM-1 and PPARα,PPARγin artery vessels in each group were analyzed.Results show that:1,The serum lipid levels of TG,TC,LDL-C,Glu were higher than those normal groups,but HDL-C was lower than the normal groups;STT has no effects on TC,LDL-C,but it can reduces the level ofHDL-C(P＜0.05).2,The levels TG,TC in liver of model group were higher than those normal groups;Comparing STT and Simvastatin treated groups with model group,TC in liver were significantly reduced(P＜0.01～P＜0.05).Also,TG in liver were reduced which treated with Simvastatin,low and middle STT(P＜0.01～P＜0.05).3,The level of MDA of model group was higher than than those normal groups,STT and Simvastatin can reduce MDA leveling serum(P＜0.01);while,Simvastatin and STTcan increase the T-AOC,and high STT was significantly increase the T-AOC level(P＜0.05).4,Aortic histomorphology changes were observed by HE staining.The damages of the aortas in STT and Simvastatin groups were less severe than that in model group.5,ICAM-1 and VCAM-1 gene expression levels in the model group were significantly higher than those of normal group(P＜0.01),but the expression of PPARα,PPARγwere lower,While compared with model group,the ICAM-1 and VCAM-1 gene expression levels in each medicated group were significantly lower (P＜0.01～P＜0.05)and the expression of PPARα,PPARγwere higher than those model groups(P＜0.01).We can get the Conclusions that STT can increase the serum lipid levels of HDL-C and T-AOC and reduce serum MDA;also,STT can down regulate the gene expression of ICAM-1,VCAM-1 and up regulate the gene expression of PPARαand PPARγin artery vessels of arterosclerotic rats,which may account for the anti-arteriosclerosis effects of STT.