Crude terpene glycoside component from Radix paeoniae rubra protects against isoproterenol-induced myocardial ischemic injury via activation of the PI3K/AKT/mTOR signaling pathway
Authors: Jie Song
Liang Feng
Lei Yang
Gang Wang
Hao Wu
Xiaobin Jia
Zhongcheng Ke
Juan Chen
Huihui Qiu
Mei Du
Journal: Journal of Ethnopharmacology (2017)
Discipline: PHARMACOLOGY & TOXICOLOGY
Keywords: Radix paeoniae rubra; chishao; terpene glycoside; myocardial ischemia; cardioprotective
Affiliations: Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210023, China; College of Chemistry and Chemical Engineering, Huangshan University, Huangshan, Anhui, 245041, China; Key Laboratory of New Drug Delivery System of Chinese Material Medica, Jiangsu Provincial Academy of Chinese Medicine, Nanjing, Jiangsu, 210028, China., Key Laboratory of New Drug Delivery System of Chinese Material Medica, Jiangsu Provincial Academy of Chinese Medicine, Nanjing, Jiangsu, 210028, China., Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210023, China; Key Laboratory of New Drug Delivery System of Chinese Material Medica, Jiangsu Provincial Academy of Chinese Medicine, Nanjing, Jiangsu, 210028, China. Electronic address: .

Abstract:  Ethnopharmacological relevance: Radix paeoniae rubra, also known as chishao (CS), is a frequently used traditional Chinese medicine that can promote blood circulation to remove blood stasis. It has been widely used for the prevention and treatment of cardiovascular diseases in China. Although terpene glycoside (TG), the major component in CS, has been shown to possess cardioprotective properties, the mechanism underlying CS-TG's preventive effect against myocardial ischemia injury is unknown. This study was conducted to explore the protective and curative effects of CS-TG against isoproterenol (ISO)-induced myocardial ischemic injury in rats and investigate the underlying myocardial protective mechanisms. Materials and methods: A rat model of ISO-induced myocardial ischemia was established to evaluate the protective effect of CS-TG in ameliorating heart injury. Myocardial ischemia was induced by administering ISO (40mg/kg/d) subcutaneously for 2 days. Serum was collected and analyzed for the levels of different cardiac biomarkers, and heart tissues were isolated and prepared for ATP analysis, glycogen content determination, histopathology assay, and ultrastructure observation. The regulatory effects of CS-TG on myocardial apoptosis in rats were studied by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, and the levels of cleaved caspase-3, Bax, and Bcl-2 were detected by western blotting. Furthermore, in vitro experiments were conducted to examine whether the CS-TG's cardioprotective effects were linked to the inhibition of apoptosis via activation of the phosphoinositide-3-kinase/serine-threonine kinase AKT/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway. Results: CS-TG (300mg/kg/d) significantly decreased serum levels of creatine kinase and lactate dehydrogenase in ISO-induced myocardial ischemic rats. Analysis of ATP and glycogen contents, myocardial ultrastructure, and pathological examination showed that CS-TG (300mg/kg/d) significantly improved energy metabolism and alleviated myocardial injury in vivo. In addition, the expression of p-AKT and p-mTOR in rats subjected to CS-TG significantly elevated, while the levels of caspase-3 and Bax/Bcl-2 dramatically reduced. Moreover, treatment with LY294002, a PI3K inhibitor, abrogated CS-TG (200μg/mL) induced down-regulation of cleaved caspase-3, Bax/Bcl-2 in the serum. Conclusions: CS-TG protects the heart from ISO-induced myocardial ischemia, potentially by improving cardiac energy metabolism and inhibiting cardiomyocyte apoptosis via activation of the PI3K/AKT/mTOR signaling pathway. Thus, CS -TG might be a potential therapeutic candidate for the prevention and treatment of myocardial ischemia. 

Retracted: No

PubPeer comments:
 Figure 6A appears to have two images which overlap. Caption reads: Fig. 6. CS-TG inhibited myocardial apoptosis in vivo. Effects of CS-TG on (A) apoptotic cardiomyocyte, (B) apoptotic index and (C) expression of cleaved caspase-3, Bcl-2, and Bax (n=3 group). **P 0.01 vs. Con; #P 0.05 vs. ISO; ##P 0.01 vs. ISO. *** ![file] ,