The Cardiotoxicity Induced by Arsenic Trioxide is Alleviated by Salvianolic Acid A via Maintaining Calcium Homeostasis and Inhibiting Endoplasmic Reticulum Stress

Arsenic trioxide (ATO) has been verified as a breakthrough with respect to the management of acute promyelocytic leukemia (APL) in recent decades but associated with some serious adverse phenomena, particularly cardiac functional abnormalities. Salvianolic acid A (Sal A) is a major effective component in treating ATO-induced cardiotoxicity. Therefore, the objective of our study was to assess whether Sal A had protective effects by the regulation of calcium homeostasis and endoplasmic reticulum (ER) stress. For the in vivo study, BALB/c mice were treated with ATO and/or Sal A via daily tail vein injections for two weeks. For the in vitro study, we detected the effects of ATO and/or Sal A in real time using adult rat ventricular myocytes (ARVMs) and an IonOptix MyoCam system. Our results showed that Sal A pretreatment alleviated cardiac dysfunction and Ca2+ overload induced by ATO in vivo and vitro. Moreover, Sal A increased sarcoplasmic reticulum (SR) Ca2+-ATPase (SERCA) activity and expression, alleviated [Ca2+]ER depletion, and decreased ER stress-related protein expression. Sal A protects the heart from ATO-induced injury and its administration correlates with the modulation of SERCA, the recovery of Ca2+ homeostasis, and the down-regulation of ER stress-mediated apoptosis.