Table 3

Activation of human and zebrafish PXRs by xenobiotics and vitamins

Cmp. #
Compound
hPXR Activity
hPXR Efficacy
zfPXR Activity
zfPXR Efficacy
Toxicity

MI1
Acetaminophen
None

None

None
MI2
3-Aminobenzoic acid
None

None

None
MI3
Benzo [a]pyren
4.75
0.55
4.00
0.06
100
MI4
n-Butyl-4-aminobenzoate
4.88
1.35
4.86
0.69
100
MI5
Butylbenzoate
None

None

None
MI6
Caffeine
None

None

None
MI7
Carbamazepine
4.20
0.37
None

200
MI8
Carbamazepine epoxide
4.09
0.57
None

200
MI9
β-Carotene
5.46
0.67
None

100
MI10
Chlorpyrifos
4.59
2.05
5.44
0.88
None
MI11
Chlorzoxazone
None

None

500
MI12
Cyclosporine
None

None

20
MI13
Ecdysone
None

None

None
MI14
Ethyl-2-aminobenzoate
None

None

None
MI15
Flurbiprofen
4.10
1.59
4.10
0.53
None
MI16
Folic acid
None

None

None
MI17
Guggulsterone
None

None

None
MI18
GW3965
None

None

10
MI19
Hyperforin
7.22
1.29
None

50
MI20
Mevastatin
5.23
0.51
None

15
MI21
Mycophenolic acid
None

None

None
MI22
Nifedipine
5.33
0.41
4.91
0.99
50
MI23
Oxcarbazepine
4.74
0.35
~4.70
~0.30
200
MI24
Paclitaxel
4.92
0.13
None

100
MI25
Phenobarbital
3.43
1.19
3.49
0.10
None
MI26
Phenytoin
4.26
0.52
None

200
MI27
n-Propyl-4-hydroxybenzoate
4.51
0.32
4.28
0.31
100
MI28
Provitamin D3
None

None

10
MI29
Provitamin D2
None

None

20
MI30
Reserpine
4.91
0.72
None

50
MI31
Retinol
5.80
0.20
None

50
MI32
Rifampicin
7.00
1.00
None

200
MI33
SR12813
6.41
0.90
None

10
MI34
TCDD
7.17
1.78
6.32
6.17
10
MI35
TCPOBOP
5.25
0.66
None

200
MI36
T-0901317
7.66
1.24
None

100
MI37
α-Tocopherol
~4.30
~0.25
None

100
MI38
β-Tocopherol
4.85
0.33
None

100
MI39
δ-Tocopherol
5.14
0.64
None

100
MI40
γ-Tocopherol
None

None

100
MI41
1α,25-Dihydroxyvitamin D3
None

None

50
MI42
1α-Hydroxyvitamin D2
None

None

50
MI43
1α-Hydroxyvitamin D3
None

None

50
MI44
Vitamin K1
4.99
0.13
None

100
MI45
Vitamin K2
5.04
0.80
None

100
MI46
Vitamin K3
~4.30
~0.15
None

100

Activities are in -log(EC50), with EC50 in molar units for the activation of human or zebrafish PXR. Efficacy is relative to 10 μM rifampicin (human PXR) or 20 μM 5α-androstan-3α-ol (zebrafish PXR) which are assigned an efficacy of 1.0. Toxicity is the lowest concentration in micromolar that produced significant toxicity in the HepG2 cells.

Ekins et al. BMC Evolutionary Biology 2008 8:103   doi:10.1186/1471-2148-8-103