Table 2.

Biological evaluation of MDR inhibitors and reference compounds

EC50 ± SEM,a (μM)
Compounds	Caco-2 [3H] vinblastine transport inhibition	MDCK-MDR1 Calcein-AM	MDCK-MRP1 Calcein-AM	MDCK-BCRP Calcein-AM
Celecoxib	30 ± 2.0	46.9 ± 2.5	10.1 ± 0.5	24.1 ± 1.2
Mitomycin C	10 ± 0.5	N.D.b	N.D.b	N.D.b
MK-571c			2.85 ± 0.25
Verapamilc	20d			3.65 ± 0.2

^aData ± SEM are the mean of three independent determinations (samples in triplicate).

^bMitomycin C activity was not determined because in the experimental conditions quenched the spectroscopic properties of the probe.

^cReference compounds for MDR pumps.

^dSee Colabufo et al. [40].