TanshinoneIIA and cryptotanshinone protect against hypoxia-induced mitochondrial apoptosis in H9c2 cells

• Published in: PloS one 2013-01, Vol.8 (1), p.e51720-e51720
• Main Authors: Jin, Hyou-Ju, Xie, Xiao-Liang, Ye, Ji-Ming, Li, Chun-Guang
• Format: Article
• Language: English
• Subjects: Alternative medicine; Angina pectoris; Animals; Apoptosis; Apoptosis - drug effects; Bax protein; Bcl-2 protein; Bioactive compounds; Biology; Cardiomyocytes; Caspase; Caspase 3 - metabolism; Caspase Inhibitors - pharmacology; Caspase-3; Cell Hypoxia - drug effects; Cell Survival - drug effects; Cryptotanshinone; Cyclosporine - pharmacology; Cytochrome; Cytochrome c; Cytochromes c - metabolism; Cytoprotection - drug effects; Diterpenes, Abietane - pharmacology; Enzyme Activation - drug effects; Health sciences; Heart attacks; Herbal medicine; Hyperpolarization; Hypoxia; Hypoxia-Inducible Factor 1, alpha Subunit - metabolism; Ischemia; Medicine; Membrane potential; Membrane Potential, Mitochondrial - drug effects; Mitochondria; Mitochondria - drug effects; Mitochondria - metabolism; Molecular modelling; Myocardial ischemia; Myocytes, Cardiac - cytology; Myocytes, Cardiac - drug effects; Myocytes, Cardiac - metabolism; Oxidative stress; Phenanthrenes - pharmacology; Physiology; Protein Stability - drug effects; Protein Transport - drug effects; Proteins; Proto-Oncogene Proteins c-bcl-2 - metabolism; Rats; Reperfusion; Rodents; Salvia miltiorrhiza; Signal transduction; Signaling; Tanshinones; Tumor necrosis factor-TNF
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0051720

Mitochondrial apoptosis pathway is an important target of cardioprotective signalling. Tanshinones, a group of major bioactive compounds isolated from Salvia miltiorrhiza, have been reported with actions against inflammation, oxidative stress, and myocardial ischemia reperfusion injury. However, the actions of these compounds on the chronic hypoxia-related mitochondrial apoptosis pathway have not been investigated. In this study, we examined the effects and molecular mechanisms of two major tanshonones, tanshinone IIA (TIIA) and cryptotanshinone (CT) on hypoxia induced apoptosis in H9c2 cells. Cultured H9c2 cells were treated with TIIA and CT (0.3 and 3 μΜ) 2 hr before and during an 8 hr hypoxic period. Chronic hypoxia caused a significant increase in hypoxia inducible factor 1α expression and the cell late apoptosis rate, which was accompanied with an increase in caspase 3 activity, cytochrome c release, mitochondria membrane potential and expression of pro-apoptosis proteins (Bax and Bak). TIIA and CT (0.3 and 3 μΜ), in concentrations without affecting the cell viability, significantly inhibited the late apoptosis and the changes of caspase 3 activity, cytochrome c release, and mitochondria membrane potential induced by chronic hypoxia. These compounds also suppressed the overexpression of Bax and reduced the ratio of Bax/Bcl-2. The results indicate that TIIA and CT protect against chronic hypoxia induced cell apoptosis by regulating the mitochondrial apoptosis signaling pathway, involving inhibitions of mitochondria hyperpolarization, cytochrome c release and caspase 3 activity, and balancing anti- and pro-apoptotic proteins in Bcl-2 family proteins.