Anti-tumor effect of Coriolus versicolor methanol extract against mouse B16 melanoma cells:: In vitro and in vivo study

Numerous studies have shown immunostimulatory and anti-tumor effects of water and standardized aqueous ethanol extracts derived from the medicinal mushroom, Coriolus versicolor, but the biological activity of methanol extracts has not been examined so far. In the present study we investigated the anti-tumor effect of C versicolor methanol extract (which contains terpenoids and poly-phenols) on B16 mouse melanoma cells both in vitro and in vivo. In vitro treatment of the cells with the methanol extract (25-1600 mu g/ml) reduced melanoma cell viability in it dose-dependent manner. Furthermore, in the presence of the methanol extract (200 mu g/ml, concentration IC50) the proliferation of B16 cells was arrested in the G(0)/G(1) phase of the cell cycle, followed by both apoptotic and secondary necrotic cell death. In vivo methanol extract treatment (i.p. 50 mg/kg, for 14 days) inhibited tumor growth in C57BL/6 mice inoculated with syngeneic B16 tumor cells. Moreover, peritoneal macrophages collected 21 days after tumor implantation from methanol extract-treated animals exerted stronger tumoristatic activity ex vivo than macrophages from control melanoma-bearing rnice. Taken together, our results demonstrate that C. versicolor methanol extract exerts pronounced anti-melanoma activity, both directly through antiproliferative and cytotoxic effects on tumor cells and indirectly through promotion of macrophage anti-tumor activity. (c) 2008 Elsevier Ltd. All rights reserved.