Background: Tanshinone IIA is a key active ingredient of danshen, which is derived from
the dried root or rhizome of Salviae miltiorrhizae Bge. The tanshinone IIA has protective effects
against the focal cerebral ischemic injury. However, the underlying mechanisms remain unclear.
Methods: An in vitro model of cerebral ischemia was established by subjecting cultures of
hippocampal neuronal cells to oxygen-glucose deprivation followed by reperfusion (OGD/R). The
probes of 5-(and-6)-chloromethyl-2’,7’-dichlorodihydrofluorescein diacetate, acetyl ester (CMH2DCFDA)
and 5’,6,6’-tetrachloro-1,1’,3,3’-tetraethylbenzimidazolylcarbocyanine,iodide (JC-1)
were used to determine the mitochondrial membrane potential (MMP) and reactive oxygen species
(ROS) production. Western-blot was used to detect the expression of proteins in HT-22 cells.
Results: The results of cell proliferative assays showed that the tanshinone IIA attenuated OGD/Rmediated
neuronal cell death, with the evidence of increased cell viability. In addition, OGD/R
exposure led to increase the levels of intracellular reactive oxygen species (ROS), which were
significantly suppressed by tanshinone IIA treatment. Furthermore, tanshinone IIA treatment
inhibited elevations in MMP and autophagy following exposure to OGD/R. Additionally, OGD/R
promoted cell death with concomitant inhibiting phosphatidylinositol-3-kinase (PI3K)/protein kinase
B (Akt)/ mammalian target of Rapamycin (mTOR) pathway, which was reversed by tanshinone IIA.
Conclusion: These results suggest that the tanshinone IIA protects against OGD/R-mediated cell
death in HT-22 cells, in part, due to activating PI3K/Akt/mTOR pathway.