Tetramethylpyrazine protects bone marrow-derived mesenchymal stem cells against hydrogen peroxide-induced apoptosis through PI3K/Akt and ERK1/2 pathways

Bone marrow-derived mesenchymal stem cells (BMSCs) transplantation is one of the new therapeutic strategies for treating ischemic stroke. However, the poor survival rate of transplanted BMSCs in ischemic tissue limits the therapeutic efficacy of this approach. Oxidative stress is a major mechanism underlying the pathogenesis of brain ischemia and has a negative impact on the survival of transplanted BMSCs. Tetramethylpyrazine (TMP) has been reported to possess potent antioxidant activity. In the present study, we aimed to investigate the protective effects of TMP pretreatment on BMSCs survival of hydrogen peroxide (H2O2)-induced apoptosis in vitro and to elucidate the potential antiapoptotic mechanisms of TMP pretreatment on BMSCs. BMSCs were pretreated with TMP (10, 25, 50, 100, and 200 µmol/L) for 24 h and then exposed to 500 µmol/L of H2O2 for 24 h. We found that TMP pretreatment significantly increased cell viability and decreased cell apoptosis and intracellular reactive oxygen species (ROS) generation. Furthermore, the protective effects of TMP were related to increased Bcl-2 expression, attenuated Bax expression, and enhanced levels of phosphorylated Akt (p-Akt) and extracellular regulated protein kinases1/2 (p-ERK1/2). Further studies found that these beneficial effects of TMP were significantly blocked by wortmannin (an inhibitor of phosphoinositide-3 kinase (PI3K)) or PD98059 (an inhibitor of ERK1/2). In conclusion, our results confirm that TMP protects BMSCs against H2O2-induced apoptosis by regulating the PI3K/Akt and ERK1/2 signaling pathways, suggesting that TMP may be used in combination with BMSCs to improve cell survival for the treatment of ischemic stroke.