Table 1. Effect of the ethanolic extract of Antrodia cinnamomea (EEAC) on rhodamine123 transport by wild-type and variant-type human P-gp.

	Nonlinear kinetic parameters
ABCB1 1236C-2677G-3435C (wild-type)	Vm (pmole/mg protein/10 mins)	Km (µM)
Nonlinear regression
Rhodamine 123 only	11.22±0.73	20.17±4.45
+ EEAC, 1 µg/ml	5.12±0.73*	21.9±3.26
+ EEAC, 5 µg/ml	3.95±1.03*	20.44±6.28
EEAC Ki estimation
Ki from Lineweaver–Burk (µg/ml)			4.5±0.83
IC50 (µg/ml)			1.51±0.08
ABCB1 1236T-2677T-3435T
Nonlinear regression
Rhodamine 123 only	9.84±1.16	24.54±1.94
+ EEAC, 1 µg/ml	4.49±0.66*	19.24±5.11
+ EEAC, 5 µg/ml	3.65±0.18*	16.83±3.23
EEAC Ki estimation
Ki from Lineweaver–Burk (µg/ml)			6.32±1.18
IC50 (µg/ml)			5.56±0.49
ABCB1 1236T-2677A-3435T
Nonlinear regression
Rhodamine 123 only	3.54±0.18	23.8±0.5
+ EEAC, 1 µg/ml	1.54±0.1*	10.7±2.91*
+ EEAC, 5 µg/ml	0.89±0.16*	8.65±1.35*
EEAC Ki estimation
Ki from Lineweaver–Burk (µg/ml)			1.45±0.66
IC50 (µg/ml)			3.33±0.67

*p<0.05 compared with rhodamine123 transport without EEAC.