No abstract

As an effective antineoplastic agent, adriamycin (ADR) remains a use for the treatment of cancer. However, it is limited by the serous cardiotoxicity. Tanshinone II A is the main effective component of Salvia miltiorrhiza Bunge which has been used for treatment of cardiovascular diseases. The purpose of this study is to evaluate the protective effect of Tanshinone II A on adriamycin-induced myocardial injury in rat and explore the mechanism of this effect. Male Wistar rats (200 ± 20 g) were divided into three groups, control (CON) group, adriamycin (ADR) group and ADR + Tanshinone II A (TRA) group. At the end of the 4 week treatment period, cardiac function was evaluated by transthoracic echocardiography. Molecular and cellular measurements were performed in atrial muscle to examine histopathological changes, the formation of fibrosis, Inflammation and apoptosis. Cardiac dysfunction was induced by adriamycin, as indicated by significant decreases in ventricular fractional shortening and ejection fraction. This adriamycin-induced cardiac dysfunction was prevented by the treatment of Tanshinone II A. Adriamycin induced pathological changes and fibrosis, activated apoptosis (increased TUNEL index, apoptotic DNA fragmentation,and caspase-3 activity and decreased Bcl-2/Bax ratio), inflammation and suppressed phosphorylation status (eIF2α and PERK) in atrial. All these molecular and cellular alterations induced by ADR were not found in the rats treated with Tanshinone II A. These findings demonstrate clearly that Tanshinone II A protects the cardiomyocytes against the ADR-induced cardiomyopathy by preventing the activation of cardiac fibrosis and apoptosis, and the effects are probably mediated through ERS pathway.