The aim of this study was to determine the anti-tumour activity of tanshinone 
IIA in SKOV3 cells. Results suggested that tanshinone IIA could significantly 
inhibit (IC50 value  =  19.6 μM) the proliferation and induce apoptosis of SKOV3 
cells as demonstrated by flow cytometry analysis. In addition, tanshinone IIA 
treatment induced G2/M phase cell cycle arrest in SKOV3 cells. The results of 
Western blotting indicated that tanshinone IIA can suppress the expression of 
anti-apoptotic protein Bcl-2, increase (0.28 vs. 0.62) the expression of 
pro-apoptotic protein Bax (0.83 vs. 0.24) in SKOV3 cells. It can be concluded 
that the tanshinone IIA may be a possible therapeutic candidate having cytotoxic 
and anti-tumour potential.