Salvianolic Acid A Protects H9c2 Cells from Arsenic Trioxide-Induced Injury via Inhibition of the MAPK Signaling Pathway.

Background/aims: This study aimed to investigate whether Salvianolic acid A (Sal A) conferred cardiac protection against Arsenic trioxide (ATO)-induced cardiotoxicity in H9c2 cells by inhibiting MAPK pathways activation.

Methods: H9c2 cardiac cells were exposed to 10 µM ATO for 24 h to induce cytotoxicity. The cells were pretreated with Sal A for 4 h before exposure to ATO. Cell viability was determined utilizing the MTT assay. The percentage of apoptosis was measured by a FITC-Annexin V/PI apoptosis kit for flow cytometry. Mitochondrial membrane potential (∆Ψm) was detected by JC-1. The intracellular ROS levels were measured using an Image-iTTM LIVE Green Reactive Oxygen Species Detection Kit. The apoptosis-related proteins and the MAPK signaling pathways proteins expression were quantified by Western blotting.

Results: Sal A pretreatment increased cell viability, suppressed ATO-induced mitochondrial membrane depolarization, and significantly altered the apoptotic rate by enhancing endogenous antioxidative enzyme activity and ROS generation. Signal transduction studies indicated that Sal A suppressed the ATO-induced activation of the MAPK pathway. More importantly, JNK, ERK, and p38 inhibitors mimicked the cytoprotective activity of Sal A against ATO-induced injury in H9c2 cells by increasing cell viability, up-regulating Bcl-2 protein expression, and down-regulating both Bax and caspase-3 protein expression.

Conclusion: Sal A decreases the ATO-induced apoptosis and necrosis of H9c2 cells, and the underlying mechanisms of this protective effect of Sal A may be connected with the MAPK pathways.