TABLE 5

Basal-to-apical permeability (efflux) of 3,5-di-O-caffeoylquinic acid in the presence of ABC transporter inhibitors

P_app values in the basal-to-apical direction were determined by analysis of the apical solution after basal incubation (1 h) of 3,5-diCQA (500 μM) with differentiated monolayers (n = 6) and ABC transporter inhibitor (apical side) at 37°C and 5% CO₂. P_app is expressed as ×10⁻⁶ ± S.D.

Inhibitor	Transporter Affected^{^a}	Permeability: P_app B→A	%Inhibition^{^b}	Inhibitor Conc.: Current Study
		cm/s		μM
Quercetin	MRP-2, BCRP, P-gp	0.13 ± 0.03	65^†	25
MK571	MRP-2	0.21 ± 0.04	46^†	25
Cyclosporine	P-gp	0.25 ± 0.06	35^†	10
Apigenin	BCRP	0.26 ± 0.04	32^†	25
Control		0.39 ± 0.03

↵† Statistical significant reduction (P < 0.05) of 3,5-diCQA efflux compared with the control condition.
↵a Inhibitor specificity evaluated by Matsson et al. (2009).
↵b %Inhibition: [(P_app control − P_app inhibitor)/(P_app control × 100).