Antiproliferative and apoptotic effects of paeonol on human hepatocellular carcinoma cells.

Paeonol, a major phenolic component of Moutan Cortex, is known to have antitumor effects through an unknown mechanism. In this study, we tried to elucidate the anticancer effects of paeonol on human hepatocellular carcinoma (HCC) cell lines BEL-7404, SMMC-7721, and MHCC97-H in vitro. Using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay, we compared the cytotoxicity of paeonol with the cytotoxicity of 5-fluorouracil (5-FU) in these three HCC cell lines. In addition, we examined the combined effect of paeonol and 5-FU over time, and found that the two compounds inhibited the proliferation of all three human HCC cell lines in a dose-dependent manner. The concentrations that inhibited the proliferation by 50% ranged from 11.39 to 56.23 mg/l for paeonol, and 6.47 to 37.87 mg/l for 5-FU. We determined that exposure to these compounds led to an upregulation of the anti-oncogene PTEN, and the downregulation of the oncogene AKT in the cell lines tested as determined by real-time quantitative reverse transcription-PCR and western blot. In addition, paeonol induced DNA fragmentation in the HCC cell line BEL-7404. These observations suggest that paeonol has the potential to be explored for use as an effective antitumor agent for HCC.