Explore the Molecular Mechanism of Apoptosis Induced by Tanshinone IIA on Activated Rat Hepatic Stellate Cells
(a) Inhibitory effect of Tan IIA upon HepG2 and HSC-T6 cell viability as measured by the MTT assays. HepG2 cells were indicated in white columns, and HSC-T6 cells were presented in grey columns. Both cells were treated with various concentrations of Tan IIA (x-axis). Data are means ± SD of three independent experiments, carried out in triplicate. (b) HSC-T6 cells were treated with 0, 3.75, 5, and 7.5 μM Tan IIA for 24 h. Samples were collected and analyzed by flow cytometry. The peak of the apoptotic phase characterized by the increase in the sub-G1 cell fraction was observed under treatment of 7.5 μM Tan IIA. Ratios of cells in the various phases are represented as a percentage. (c) Treatment of 7.5 μM Tan IIA significantly induced caspase-3, -9 activation and PARP cleavage at 24 h. β-actin was used as an internal control. (d) The cytosolic and mitochondria fractions were prepared and subjected to western blot using a specific antibody. COXIV used as a specific mitochondria marker protein was not identified in cytosol fraction to confirm a complete separation of cell fractions. GAPDH was applied as an internal control.