MRP-S7 contains inhibitors, such as, Verapamil is a phenylalkylamine calcium channel blocker that also acts on MRP1, while Probenecid is an organic anion compound known to modulate MRP2 and MRP4. MK-571 is a leukotriene receptor antagonist with potent inhibitory effects on MRP1 and MRP2, indicating its ability to block leukotriene transport. Flavonoids like Quercetin exert their inhibitory action by disrupting ATPase activity, essential for the MRP-mediated efflux function. Curcumin, a polyphenol, has been reported to inhibit MRP1, although the exact mechanism remains less clear.
These inhibitors operate by either directly inhibiting the ATPase activity required for substrate efflux or by competing with substrates for binding sites on the transporter. This class of inhibitors is not uniform in its action; rather, it encompasses a broad range of substances that can affect the transporters in multiple ways.Consequently, the inhibition of these proteins can lead to an accumulation of substrates within the cells.