Impact of electroacupuncture on liver lipid metabolism and hepatic Sirt1 and PPARγ expression in abdominal obese rats / 针刺研究

ABSTRACT

OBJECTIVE: To observe the impact of electroacupuncture (EA) on liver lipid metabolism and expression of hepatic sirtuin 1(Sirt1) and peroxisome proliferator activated receptor γ(PPARγ) of abdominal obese rats induced by high-fat diet. METHODS: Eighteen male SD rats were divided into blank control, model and EA groups (n＝6 per group). The abdominal obesity model was established by feeding the rats with high-fat diet for 12 weeks. EA (2 Hz/15 Hz, 1.5 mA) was applied to bilateral "Daimai"(GB26) for 20 min every time, once every other day for 8 weeks. Rats of the model group were also restrained for 20 min. The body mass and abdominal circumference were measured every week, and the contents of serum cholesterol (TC), triglyceride (TG), alanine transaminase (ALT), aspartate aminotransferase (AST) were detected by using an automated biochemical analyzer. Histopathological changes of the liver tissues were observed under microscope after oil red "O" staining. The expression of hepatic Sirt1 and PPARγ mRNAs and proteins were detected using quantitative real time PCR and Western blot, separately. RESULTS: After modeling, the body weight and abdominal circumference, and serum TC, TG, ALT and AST contents, and expression of hepatic PPARγ mRNA and protein were significantly increased (P<0.001, P<0.01, P<0.05), and the expression levels of hepatic Sirt1 mRNA and protein obviously down-regulated (P<0.05, P<0.01) in the model group. Following EA intervention, the increased body weight and abdominal circumference, and serum TC, TG, ALT and AST contents, and hepatic PPARγ mRNA and protein expression were remarkably suppressed (P<0.05, P<0.01), and the decreased hepatic Sirt1 mRNA and protein were remarkably up-regulated (P<0.001，P<0.05). The lipid droplets in hepatocytes were reduced in the EA group relevant to the model group. CONCLUSION: EA intervention can significantly improve the liver lipid metabolism of abdominal obese rats, which is possibly related with its effect in up-regulating the expression of hepatic Sirt1 mRNA and protein, and in down-regulating the expression of hepatic PPARγ mRNA and protein.