Magnolol Induces Apoptosis and Inhibits ERK-modulated Metastatic Potential in Hepatocellular Carcinoma Cells

Background/Aim: The aim of the present study was to evaluate the anti-cancer effect of magnolol in hepatocellular carcinoma (HCC) cells in vitro. Materials and Methods: HCC SK-Hep1 cells were treated with different concentrations of magnolol or PD98059 [extracellular-signal-regulated kinase (ERK) inhibitor] for 48 h, and then cell viability, apoptosis, signal transduction, expression of anti-apoptotic and metastasis-related proteins, and cell invasion were investigated by [3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assay, flow cytometry, nuclear factor kappa B (NF-kappa B) reporter gene, western blotting, and cell invasion assays. Results: Magnolol significantly induced accumulation of sub-G(1) phase and caspase-3 activation and inhibited NF-kappa B activation, cell invasion, expression of phosphorylated ERK (pERK), anti-apoptotic and metastatic-related proteins. ERK inactivation was required for magnolol-induced inhibition of metastatic potential of SK-Hep1 cells. Conclusion: Taken together, these results indicated that magnolol not only induced apoptosis, but also inhibited ERK-modulated metastatic potential of HCC SK-Hep1 cells.