Study on Protective Mechanism of Dracocephalum moldavica Total Flavonoids against Myocardial Ischemia- reperfusion Injury in Rats Based on AMPK/SIRT 1/PGC-1α Signaling Pathway / 中国药房

ABSTRACT

OBJECTIVE：To s tudy the effects of Dracocephalum moldavica total flavonoids （TFDM）on AMPK/SIRT 1/PGC-1α signaling pathway ，and to explore the mechanism of its protective effect on myocardial ischemia reperfusion injury （MIRI）rats. METHODS：Totally 50 healthy male SD rats were randomly divided into sham operation group ，model group ，TFDM group [ 60 mg/（kg·d），by extract] ，Compound C+TFDM group [ig administration of 60 mg/（kg·d）TFDM+intravenous injection of 250 μg/kg Compound C（AMPK inhibitor ）via tail vein 15 min before reperfusion] ，EX-527+TFDM group [ig administration of 60 mg/ （kg·d）TFDM+ip injection of 5 mg/kg EX- 527（SIRT1 inhibitor）20 min before reperfusion] ，with 10 rats in each group. They were given relevant medicine intragastrically ，once a day ，for consecutive 7 days. After last ig administration ，sham operation group underwent sham operation ，other 4 groups were established MIRI model by ligating left anterior descending coronary artery ， ischemia for 30 min and reperfusion for 2 h. After reperfusion ，the myocardial histopathological changes were observed by HE staining；RP-HPLC method was used to determine the contents of ATP ，ADP，AMP and NAD + in cardiac tissue. mRNA expressions of AMPK ，SIRT1 and PGC- 1α were detected by quantitative real-time PCR assay. Western blotting assay was the expressions of SIRT 1 and PGC- 1α protein in myocardium. RESULTS： Compared with sham operation group ， model group showed myocardial fib ers arranged disorder and horizontal stripes disappearance ，cell swelling burst and necrosis ，and nuclei deformation displacement ；the contents of ATP and NAD+，mRNA expression of AMPK ，SIRT1 and PGC- 1α，protein expression of SIRT 1 and PGC- 1α in cardiac tissue were decreased significantly （P＜0.05 or P＜0.01）；the contents of ADP and AMP ，the phosphorylation level of AMPK protein were increased significantly （P＜0.01）. Compared with model group ，myocardial pathological morphology were improved significantly in TFDM group ；the contents of ATP and NAD + in cardiac tissue ，mRNA expression of AMPK ，SIRT1 and PGC- 1α，the phosphorylation level of AMPK protein ，the protein expression of SIRT 1 and PGC- 1α were increased significantly（P＜0.05 or P＜ 0.01），while the contents of ADP and AMP were decreased significantly （P＜0.01）. Compared with TFDM group ，improvement effects of Compound C + TFDM group and EX- 527 + TFDM group on above indexes were reversed （P＜0.05 or P＜0.01）. CONCLUSIONS：TFDM may play a protective role on myocardium by activating AMPK/SIRT 1/PGC-1α signaling pathway and regulating energy metabolism.