MEK/ERK pathway mediates cytoprotection of salvianolic acid B against oxidative stress-induced apoptosis in rat bone marrow stem cells.

To improve the survival and/or differentiation of grafted BMSCs (bone marrow stem cells) represents one of the challenges for the promising cell-based therapy. Considerable reports have implicated Sal B (salvianolic acid B), a potent aqueous extract of Salvia miltiorrhiza, in enhancing the survival of cells under various conditions. In this study, we investigated the effect of Sal B on H₂O₂-induced apoptosis in rat BMSCs, focusing on the survival signalling pathways. Results indicated that the MEK [MAPK (mitogen-activated protein kinase)/ERK (extracellular-signal-regulated kinase) kinase] inhibitor (PD98059) and 10 μM Sal B remarkably prevented BMSCs from H₂O₂-induced apoptosis through attenuating caspase-3 activation, which is accompanied by the significant up-regulation of Bcl-2. In addition, the ROS (reactive oxygen species) accumulation was also reduced after Sal B treatment. Furthermore, Sal B inhibited the ERK1/2 phosphorylations stimulated by H₂O₂. Taken together, our results showed that H₂O₂-induced apoptosis in BMSCs via the ROS/MEK/ERK1/2 pathway and Sal B may exert its cytoprotection through mediating the pathway.