Table 1.

Reversal effects of Y₆ to ABCB1-mediated MDR in HEK293/pcDNA3.1 and HEK293/ABCB1 cell lines.

Treatment	HEK293/pcDNA3.1		HEK293/ABCB1
	IC50±SDa (μmol/L)	RFb	IC50±SD (μmol/L)	RF
Doxorubicin	0.34±0.03	[1.0]	8.80±0.32	[25.9]
+ EGCG (1 μmol/L)	0.30±0.08	[0.9]	1.43±0.08	[4.2]*
+ Y6 (1 μmol/L)	0.35±0.01	[1.0]	1.03±0.05	[3.0]*,#
+ Y6 (2 μmol/L)	0.29±0.05	[0.9]	0.62±0.09	[1.8]*
+ Verapamil (1 μmol/L)	0.39±0.05	[1.1]	0.77±0.03	[2.3]*
Cisplatin	1.07±0.07	[1.0]	1.05±0.05	[1.0]
+ EGCG (1 μmol/L)	0.92±0.01	[0.9]	1.01±0.01	[1.0]
+ Y6 (1 μmol/L)	0.96±0.04	[0.9]	1.05±0.06	[1.0]
+ Verapamil (1 μmol/L)	0.91±0.02	[0.8]	0.92±0.07	[0.9]

^*P < 0.05 versus no reversal agent group.

^#P < 0.05 versus doxorubicin–EGCG group

^aIC₅₀ values are represented as mean ± SD of three independent experiments performed in triplicate.

^bValues represent the resistance fold (RF) calculated by dividing IC₅₀ values of anticancer drug in HEK293/pcDNA3.1 and HEK293/ABCB1 cells in presence or absence reversal agent by the IC₅₀ value of HEK293/pcDNA3.1 cells without reversal agent.