Aim of this study: Phellinus igniarius (Linnearus: Fries) Quelet (Phellinus igniarius) has been used in oriental countries for treatment of various diseases including cancer. However, it is unclear how Phellinus igniarius exerts anticancer effects.
Materials and methods: In this study the ethanolic extract from the fruiting body of Phellinus igniarius (EEPI) was used to evaluate the antiproliferative and antimetastatic effects in human hepatocarcinoma SK-Hep-1 cells and rat heart vascular endothelial cells (RHE cells).
Results: We found that EEPI inhibited the proliferation of both cell lines in a dose-dependent manner, and the IC50 values at 48 h were 72 and 103 microg/ml for SK-Hep-1 cells and RHE cells, respectively. EEPI at non- or sub-cytotoxic concentrations (25-100 microg/ml) markedly inhibited the migration and invasion of SK-Hep-1 cells. EEPI added at 25 microg/ml significantly decreased the secretion of matrix metalloproteinase-2 (MMP-2) (49%, p<0.01) and vascular endothelial growth factor (VEGF) (13%, p<0.05) in SK-Hep-1 cells. EEPI at 25 microg/ml completely inhibited matrigel-induced tube formation in RHE cells. Importantly, EEPI (25 or 50 microg/ml) in combination with oxaliplatin (Oxa) or 5-flurouracil (5-FU) synergistically inhibited the proliferation of SK-Hep-1 cells.
Conclusion: These results demonstrate the antiproliferative and antimetastatic effects of EEPI in vitro and the potential of EEPI as an adjuvant for chemotherapy.