NSC23925 is a selective and effective inhibitor of P-glycoprotein (Pgp).

NSC23925 specifically inhibits Pgp overexpression to prevent the emergence of paclitaxel resistance during paclitaxel treatment. NSC23925 reverses chemoresistance in a wide variety of tumor types where Multidrug resistance 1 (MDR1) is highly expressed. SKOV-3 cells with long-term exposure of 1 μM NSC23925 display stable growth in the culture medium. However, the mean concentration of NSC23925 required for maximal reversal of resistance in SKOV-3TR or OVCAR8TR to cytotoxic drugs is 0.5 μM to 1 μM. The IC50 for NSC23925 is 8 μM in SKOV-3/SKOV-3TR and 25 μM in OVCAR8/OVCAR8TR cell lines. Maximal reversal of MDR is typically seen in NSC23925 doses between 0.5 and 1 μM [1][2].

The usage of NSC23925 significantly prolongs the anticancer efficacy of paclitaxel in paclitaxel chemotherapy. Both saline alone and NSC23925 alone treated tumors grow progressively [1].