Date Published: February 9, 2017
Publisher: Public Library of Science
Author(s): Shuang-Wei Zhang, Yu Liu, Fang Wang, Jiao Qiang, Pan Liu, Jun Zhang, Jin-Wen Xu, Anindita Das.
The protective effects of ilexsaponin A on ischemia-reperfusion-induced myocardial injury were investigated. Myocardial ischemia/reperfusion model was established in male Sprague–Dawley rats. Myocardial injury was evaluated by TTC staining and myocardial marker enzyme leakage. The in vitro protective potential of Ilexsaponin A was assessed on hypoxia/reoxygenation cellular model in neonatal rat cardiomyocytes. Cellular viability and apoptosis were evaluated by MTT and TUNEL assay. Caspase-3, cleaved caspase-3, bax, bcl-2, p-Akt and Akt protein expression levels were detected by western-blot. Ilexsaponin A treatment was able to attenuate the myocardial injury in ischemia/reperfusion model by reducing myocardial infarct size and lower the serum levels of LDH, AST and CK-MB. The in vitro study also showed that ilexsaponin A treatment could increase cellular viability and inhibit apoptosis in hypoxia/reoxygenation cardiomyocytes. Proapoptotic proteins including caspase-3, cleaved caspase-3 and bax were significantly reduced and anti-apoptotic protein bcl-2 was significantly increased by ilexsaponin A treatment in hypoxia/reoxygenation cardiomyocytes. Moreover, Ilexsaponin A treatment was able to increase the expression levels of p-Akt in hypoxia/reoxygenation cellular model and myocardial ischemia/reperfusion animal model. Coupled results from both in vivo and in vitro experiments indicate that Ilexsaponin A attenuates ischemia-reperfusion-induced myocardial injury through anti-apoptotic pathway.
Myocardial ischemia reperfusion injury is one of the leading causes of death worldwide. Although early reperfusion therapy with thrombolytic drugs in myocardial infarction (MI) patients could reduce myocardial infarction size, this therapy tends to induce ischemia-reperfusion (IR) injury [1–3]. Various pharmacological agents have been developed to reduce IR injury, however, none of them have been used for MI patients in clinical practice [3–5]. Thus, further studies are needed to find novel drugs to combat myocardial IR injury.
Previous studies have shown that the main active components of MDQ are triterpene saponins [6–8], lignan glycosides , phenylethanols , and other minor compounds [20–21]. Several triterpene saponins have been isolated from MDQ and have been shown to have anti-inflammatory and anti-tumor effects [6,8]. However little is known about their effects on cardiovascular system. We isolated Ilexsaponin A which is one of representative saponins in MDQ (Fig 1). Our study showed that both low dose (10mg/Kg) and high dose (40mg/Kg) of Ilexsaponin A pretreatment were able to decrease the myocardial infarct size in myocardial ischemia/reperfusion rats. In order to confirm this protective effect, we furthermore investigated the levels of markers of myocardial tissue damage, such LDH, AST and CK-MB. The levels of these markers in rat’s serum were significantly increased after myocardial ischemia/reperfusion injury. Ilexsaponin A pretreatment in myocardial ischemia/reperfusion rats was able to decrease the levels of LDH, AST and CK-MB in the serum. These results indicates that Ilexsaponin A protect against myocardial tissue damage in ischemia/reperfusion rats.