Tanshinone IIA (Tanshinone B)(Tanshinone B) is the diterpene quinone in Danshen, which is utilized in the treatment of cardiovascular and inflammatory.

In rats, the LD50 of Tanshinone IIA administered via gavage (oral administration) is 25 g/kg.

In cardiomyocytes, Tanshinone IIA can inhibit oxidative stress-induced apoptosis.

Tanshinone IIA (Tan IIA) is dissolved in DMSO (10 mM) and stored (in dark and -20°C), and serially diluted in a RPMI 1640 medium immediately prior to experiments[1]. A549 cells are counted in logarithmic phase and 6000 cells (90 μL volume) are placed in 96-well plates. 10 μL varying concentrations of Tanshinone IIA (final concentrations 80, 60, 40, 30, 20, 15, 10, 5 and 2.5 μM) and ADM (final concentrations 8, 4, 2, 1, 0.5 and 0.25 μM) are added into drug groups, while negative control group (vehicle group) is only added 10 μL DMSO or normal saline without Tanshinone IIA or ADM. Cells are incubated for an additional 2 h with CCK-8 reagent (100 μL/mL medium) and the absorbance is read at 450 nm using a microplate reader. Cell proliferation inhibition rates are calculated according to the following formula: the proliferation inhibition ratio (%)=1-[(A1-A4)/(A2-A3)]×100, where, A1 is the OD value of drug experimental group, A2 is the OD value of blank control group, A3 is the OD value of the RPMI1640 medium without cells, and A4 is the OD value of drugs with the same concentration as A1 but without cells. The IC50 value, which represents the concentration of the drug that demonstrates 50% of cell growth inhibition, is calculated by nonlinear regression analysis using GraphPad Prism software[1].