Table 1.

Flow cytometry analysis of P-gp functional activity with R123 or JC-1 in A549, HepG2, and MCF-7 cells.

Sample	Intracellular accumulation of JC-1 and R123 (%)
	A549	HepG2	MCF-7
R123	100.0 ± 5.1	100.0 ± 7.2	100.0 ± 6.2
R123 + V	70.6 ± 7.2	124.89 ± 3.7*	110.8 ± 3.9
R123 + DOX	129.7 ± 3.6*	126.88 ± 9.2*	148.2 ± 8.3∗+
R123 + ACL	111.2 ± 5.9	157.29 ± 6.5∗+	137.7 ± 11.7∗+
JC-1	100.0 ± 2.9	100.0 ± 4.7	100.0 ± 8.6
JC-1 + V	85.2 ± 5.6	212.41 ± 5.2*	161.2 ± 8.9*
JC-1 + DOX	92 ± 5.5	250 ± 2.9∗+	386.8 ± 13.3∗+
JC-1 + ACL	86.9 ± 13.9	212.59 ± 7.0∗+	158.3 ± 14.6*

Results represent means ± SD of 4 independent experiments. *P < 0.05, significant differences between P-gp functional activity calculated from influx of R123 or JC-1 and R123 or JC-1 plus Verapamil and from R123 or JC-1 plus ACL or DOX after a 30-minute period of time monitoring the transport of fluorescence probes to the cells. ⁺ P < 0.05, significant differences between positive control samples (cells preincubated with Verapamil) and cells treated with DOX or ACL. P-gp functional activity was evaluated based on the basis of fluorescence ratios of R123 or JC-1 (Figure 4) and calculated for each tested probe. The final results were presented as percentage values.