MC-70 is a potent P-gp inhibitor (EC50 = 0.69 μM). Multidrug resistance (MDR) is the major cause of the failure of cancer therapy since this phenomenon generates cancer cells that are unresponsive to chemotherapeutic agents. P-glycoprotein (P-gp) is a well-known membrane transporter expressed in a number of strategic biological barriers, where it exerts a protective effect of paramount importance.
