黄精多糖对高脂血症小鼠脂代谢相关基因mRNA及蛋白表达的影响

Effect of polysaccharides from Polygonatum sibiricum on lipid-metabolism related mRNA and protein expression in hyperlipidemic mice

该文旨在研究黄精多糖对高脂血症小鼠脂代谢相关基因mRNA及蛋白表达的影响,将小鼠随机分为空白对照组,高脂血症模型组,辛伐他汀组,黄精多糖低、中、高剂量组(200,400,800 mg·kg^-1·d^-1),连续给药14 d后,腹腔注射75%新鲜蛋黄乳剂建立高脂血症小鼠模型。给药结束后测定血清中TC,TG,LDL-C,HDL-C的含量;采用Real-time PCR法测定肝脏组织中PPAR-α,PPAR-β,PPAR-γ,SREBP-1c,IL-6,TNF-αmRNA的表达水平;通过Western blot法分析检测黄精多糖对脂代谢相关基因(PPAR-α,PPAR-β,PPAR-γ,SREBP-1c,IL-6,TNF-α)蛋白表达的影响,以探讨黄精多糖的降血脂机制。实验结果表明,黄精多糖低、中、高剂量组均能降低血清中TC,TG,LDL-C的含量,以中、高剂量组多糖效果最为显著(P<0.01),同时,黄精多糖低、中、高剂量组均能升高血清中HDL-C的含量,以中、高剂量组多糖效果最为显著(P<0.01);此外,黄精多糖中、高剂量组可显著上调肝脏中PPAR-α,PPAR-βmRNA和蛋白表达量(P<0.05),下调肝脏中PPAR-γ,SREBP-1c,IL-6,TNF-αmRNA和蛋白表达量(P<0.05)。以上研究表明黄精多糖具有抑制肝脏脂质氧化,调节与脂类代谢相关基因和蛋白表达的作用,进而起到防治高脂血症的功效。

To study the effect of polysaccharides from Polygonatum sibiricum on mRNA and protein expressions of blood lipid metabolism in hyperlipidemic mice. The mice were randomly divided into 6 groups,namely the blank control group,the hyperlipidemia model group,the simvastatin group,and low,middle and high-dose PSP groups( 200,400,800 mg·kg^-1·d^-1). Each group of the mice was administrated intragastrically for 14 days,respectively. Subsequently,every group of mice,except for the blank control group,was intraperitoneally injected with 75% fresh egg yolk emulsion for establishing the hyperlipidemic mice model. Upon completion of the administration,the contents of TC,TG,LDL-C and HDL-C in serum of each group were investigated in details. In particular,the mRNA expression levels of PPAR-α,PPAR-β,PPAR-γ,SREBP-1 c,IL-6 and TNF-α of the liver tissues were detected by Real-time PCR,and the protein expression levels( including PPAR-α,PPAR-β,PPAR-γ,SREBP-1 c,IL-6,TNF-α) were examined by Western blot. Consequently,the obtained results showed that the contents of the serum TC,TG,LDL-C of low,middle and high-dose PSP groups significantly decreased compared with those of the hyperlipidemia model group. Simultaneously,there were significant differences between middle-dose and high-dose PSP groups( P < 0. 01). In striking contrast,the contents of serum HDL-C of low,middle and high-dose PSP groups significantly increased,while obvious differences were also observed between middle-dose and highdose PSP groups( P < 0. 01). Moreover,middle-dose and high-dose PSR groups could up-regulate the protein and mRNA expressions of PPAR-α,PPAR-β( P < 0. 05) compared with those of the hyperlipidemia model group,and down-regulate the expressions of PPAR-γ,SREBP-1 c,IL-6 and TNF-α( P < 0. 05) compared with those of liver tissues of the hyperlipidemia model group. In conclusion,all of the above results suggested that PSP could inhibit the oxidation of the liver lipid,and regulate the expression levels of the corresponding genes and proteins relating to the lipid metabolism,so as to play a critical role for preventing hyperlipidemia.