Effect of the combination of tanshinone IIA and statin treatments on PCSK9 protein expression and LDLR activity.

<p>The HepG2 cells were cultured in LPDS medium and pretreated with the vehicle or tanshinone IIA (10 μM) for 1 h and then incubated with 1 μM lovastatin or simvastatin for an additional 24 h. (A) The PCSK9 protein level was measured by western blot analysis. The immunoblot experiments were repeated three times, and a representative blot is shown. The normalized intensity of mature PCSK9 (m) versus β-actin is presented as the mean ± SD of three independent experiments. **<i>p</i><0.01 represents a significant difference compared to the vehicle-treated cells. ##<i>p</i><0.01 represents a significant difference compared to the statin (lovastatin or simvastatin) alone treatment group. (B) The LDL uptake by the cells was measured by flow cytometry analysis, and the data are expressed as the geometric mean fluorescence intensity. The data represent the mean ± SD from three independent experiments. **<i>p</i><0.01 represents a significant difference compared to the tanshinone IIA-untreated vehicle group. ##<i>p</i><0.01 represents a significant difference compared to the tanshinone IIA-untreated cells.