Reversal of resistance to doxorubicin with cepharanthine in murine P388 leukemia cells.

Cytotoxic effect in vitro and antitumor effect in vivo of doxorubicin (DOX) combined with cepharanthine were investigated on DOX-resistant murine P388 leukemia (P388/R) cells. Cepharanthine was minimally cytotoxic in the cell line, but reversed DOX-resistance in a dose-related manner in P388/R cells. The administration of cepharanthine to mice bearing the P388 leukemia enhanced the antitumor activity of DOX. These results indicate that cepharanthine is an effective agent to reverse DOX-resistant cells.