Steroidal saponin of Trillium tschonoskii. Reverses multidrug resistance of hepatocellular carcinoma.

Combating with multidrug resistance (MDR) is a major part of hepatocellular carcinoma (HCC) chemotherapy. Steroidal saponin from Trillium tschonoskii (TTS) could be a potential weapon. We found TTS could reverse the MDR in HCC cells and significantly enhance chemosensitization. TTS inhibited HepG2 and R-HepG2 cells survival in a dose-dependent manner by 75% and 76%, respectively (p<0.01), as well as colony formation 77% and 81% (p<0.01). Moreover, TTS induced sensitization of R-HepG2 to anti-cancer drugs, indicated by significantly reduced IC50. On the other hand, TTS suppressed expression of P-glucoprotein in MDR HCC cells, and thereby increased accumulation of doxorubicin from 126 ng/10(5)cells to 752 ng/10(5)cells (p<0.01). TTS also repressed expression of many other MDR genes, such as MRP1, MRP2, MRP3, MRP5, MVP and GST-π. In vivo, TTS dose-dependently reduced R-HepG2 cells xenografts tumour formation by inhibiting tumour cells proliferation in mice. Consistence with in vitro finding, TTS induced R-HepG2 sensitization to doxorubicin and therefore reduced tumour formation in vivo.