Polyoxovanadates as new P-glycoprotein inhibitors: insights into the mechanism of inhibition.

A promising strategy to overcome multidrug resistance is the use of inhibitors of ABC drug transporters. For this reason, we evaluated the polyoxovanadates (POVs) [V O ] (V ), [H V O (PO )] (V ), [V O Cl] (V ) and [V O I] (V ) as inhibitors of three major multidrug resistance-linked ABC transporters: P-glycoprotein (P-gp), ABCG2 and MRP1. All of the POVs selectively inhibited P-gp.