title: Panax notoginseng saponins inhibit ischemia-induced apoptosis by activating PI3K/Akt pathway in cardiomyocytes.
abstract: OBJECTIVE
  The panax notoginseng saponins (PNS) have been clinically used for the treatment of cardiovascular diseases and stroke in China. Evidences demonstrated that PNS could protect cardiomyocytes from injury induced by ischemia, but the underlying molecular mechanisms of this protective effect are still unclear. This study was aimed to investigate the protective effect and potential molecular mechanisms of PNS on apoptosis in H9c2 cells in vitro and rat myocardial ischemia injury model in vivo.
  
  
  METHODS
  H9c2 cells subjected to serum, glucose and oxygen deprivation (SGOD) were used as in vitro models and SD rats subjected to left anterior descending (LAD) coronary artery ligation were used as in vivo models. The anti-apoptotic effect of PNS was evaluated by Annexin V/PI analysis or TUNEL assay. Mitochondrial membrane potential (Δψm) was detected by JC-1 analysis. The expression of Akt and phosphorylated Akt (p-Akt) were detected by western blot assay.
  
  
  RESULTS
  PNS exhibited anti-apoptotic effect both in H9c2 cells and in ischemic myocardial tissues. However, the effect was blocked in vitro by LY294002, a specific PI3K inhibitor. The anti-apoptotic effect of PNS was mediated by stabilizing Δψm in H9c2 cells. Furthermore the indices of the left ventricular ejection fractions (EF), left ventricular fractional shortening (FS), left ventricular dimensions at end diastole (LVDd) and left ventricular dimensions at end systole (LVDs) suggested that PNS improved rats cardiac function. PNS significantly increased p-Akt both in H9c2 cells and in ischemic myocardial tissues and this effect was also blocked by LY294002 in H9c2 cells.
  
  
  CONCLUSIONS
  Results of this study suggested that PNS could protect myocardial cells from apoptosis induced by ischemia in both the in vitro and in vivo models through activating PI3K/Akt signaling pathway.
authors.affiliation: Medical Research Center, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China. chenshx127@yahoo.com.cn
authors.forename: Shaoxian
authors.initials: S
authors.lastname: Chen
authors.forename: Juli
authors.initials: J
authors.lastname: Liu
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Liu
authors.forename: Yongheng
authors.initials: Y
authors.lastname: Fu
authors.forename: Mengzhen
authors.initials: M
authors.lastname: Zhang
authors.forename: Qiuxiong
authors.initials: Q
authors.lastname: Lin
authors.forename: Jiening
authors.initials: J
authors.lastname: Zhu
authors.forename: Liping
authors.initials: L
authors.lastname: Mai
authors.forename: Zhixin
authors.initials: Z
authors.lastname: Shan
authors.forename: Xiyong
authors.initials: X
authors.lastname: Yu
authors.forename: Min
authors.initials: M
authors.lastname: Yang
authors.forename: Shuguang
authors.initials: S
authors.lastname: Lin
mesh_terms: D000818:Animals; D017304:Annexin A5 / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D002316:Cardiotonic Agents / Q000302:isolation & purification / Q000494:pharmacology*; D002460:Cell Line; D019610:Cytoprotection; D004195:Disease Models, Animal; D004789:Enzyme Activation; D020287:In Situ Nick-End Labeling; D008297:Male; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D015428:Myocardial Reperfusion Injury / Q000201:enzymology / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D053723:Panax notoginseng / Q000737:chemistry; D058539:Phosphatidylinositol 3-Kinase / Q000378:metabolism*; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function; D012503:Saponins / Q000302:isolation & purification / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D013318:Stroke Volume / Q000187:drug effects; D013997:Time Factors; D016277:Ventricular Function, Left / Q000187:drug effects
chemical_list: D017304:Annexin A5; D002316:Cardiotonic Agents; D000081082:Phosphoinositide-3 Kinase Inhibitors; D047428:Protein Kinase Inhibitors; D012503:Saponins; D058539:Phosphatidylinositol 3-Kinase; D051057:Proto-Oncogene Proteins c-akt