Green Tea (Camellia sinensis) 19124972
Inhibition by green tea catechins of metabolic activation of procarcinogens by human cytochrome P450 CSV JSON

Inhibition by green tea catechins of metabolic activation of procarcinogens by human cytochrome P450.


1 . Percent inhibition of CYP2E1 by epicatechin gallate (id=NPDI-4i54tA)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — not provided

4-nitrophenol

epicatechin gallate

4-nitrocatechol

  • CYP2E1 4173608

Recombinant expression system Not available
Cytochrome B5 Not available

Results

Percent inhibition at 100 µM as estimated from Fig. 3 is presented.

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

Experiments were conducted using TA1538 cell membrane fractions expressing P450 reductase and individual CYP isoforms.

CYP: 20 pmol/mL

In-house preparation

0.5 mL

30 min at pH 6.8

NADPH regenerating system

Not available

Not available

100 µM

0-100 µM

2 . Unnamed Experiment (id=NPDI-_5Ix4Q)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — N/A

4-nitrophenol

epigallocatechin gallate 19058494

4-nitrocatechol

  • CYP2E1 4173608

Recombinant expression system Not available
Cytochrome B5 Not available

Results

The apparent Ki value is presented in the table.
Additional study using TA1538 cell membrane fractions of P450 reductase found that (-)-epigallocatechin gallate inhibited this enzyme competitively with an apparent Ki value of 2.5 µM.

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

Experiments were conducted using TA1538 cell membrane fractions expressing P450 reductase and individual CYP isoforms.

CYP: 20 pmol/mL

In-house preparation

0.5 mL

30 min at pH 6.8

NADPH regenerating system

Not available

Not available

100 µM

50 µM

3 . Percent inhibition of CYP1A1 by epicatechin gallate (id=NPDI-X_yVFw)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — not provided

7-ethoxycoumarin

epicatechin gallate

coumarin 19008106

  • CYP1A1 4173297

Recombinant expression system Not available
Cytochrome B5 Not available

Results

Percent inhibition at 100 µM as estimated from Fig. 3 is presented.

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

Experiments were conducted using TA1538 cell membrane fractions expressing P450 reductase and individual CYP isoforms.

CYP: 20 pmol/mL

In-house preparation

0.5 mL

15 min

NADPH regenerating system

Not available

Not available

10 µM

0-100 µM

4 . Unnamed Experiment (id=NPDI-vyz23w)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — N/A

7-ethoxycoumarin

epigallocatechin gallate 19058494

coumarin 19008106

  • CYP1A1 4173297

Recombinant expression system Not available
Cytochrome B5 Not available

Results

The apparent Ki value is presented in the table.

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

Experiments were conducted using TA1538 cell membrane fractions expressing P450 reductase and individual CYP isoforms.

CYP: 20 pmol/mL

In-house preparation

0.5 mL

15 min

NADPH regenerating system

Not available

Not available

10 µM

50 µM

5 . Percent inhibition of CYP1A2 by epicatechin gallate (id=NPDI-ArhlIA)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — not provided

7-ethoxyresorufin -7999995

epicatechin gallate

resorufin -7999853

  • CYP1A2 4312402

Recombinant expression system Not available
Cytochrome B5 Not available

Results

Percent inhibition at 100 µM as estimated from Fig. 3 is presented.

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

Experiments were conducted using TA1538 cell membrane fractions expressing P450 reductase and individual CYP isoforms.

CYP: 40 pmol/mL

In-house preparation

0.5 mL

10 min

NADPH regenerating system

Not available

Not available

1 µM

0-100 µM

6 . Unnamed Experiment (id=NPDI-p7eJTA)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — N/A

7-ethoxyresorufin -7999995

epigallocatechin gallate 19058494

resorufin -7999853

  • CYP1A2 4312402

Recombinant expression system Not available
Cytochrome B5 Not available

Results

The apparent Ki value is presented in the table.
Additional study using TA1538 cell membrane fractions of P450 reductase found that (-)-epigallocatechin gallate inhibited this enzyme competitively with an apparent Ki value of 2.5 µM.

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

Experiments were conducted using TA1538 cell membrane fractions expressing P450 reductase and individual CYP isoforms.

CYP: 40 pmol/mL

In-house preparation

0.5 mL

10 min

NADPH regenerating system

Not available

Not available

1 µM

10 µM

7 . Percent inhibition of CYP2A6 by epicatechin gallate (id=NPDI-CPfQsA)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — not provided

coumarin 19008106

epicatechin gallate

7-hydroxycoumarin

  • CYP2A6 4309826

Recombinant expression system Not available
Cytochrome B5 Not available

Results

Percent inhibition at 100 µM as estimated from Fig. 3 is presented.

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

Experiments were conducted using TA1538 cell membrane fractions expressing P450 reductase and individual CYP isoforms.

CYP: 20 pmol/mL

In-house preparation

0.5 mL

15 min

NADPH regenerating system

Not available

Not available

1 µM

0-100 µM

8 . Unnamed Experiment (id=NPDI-q6-gZQ)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — N/A

coumarin 19008106

epigallocatechin gallate 19058494

7-hydroxycoumarin

  • CYP2A6 4309826

Recombinant expression system Not available
Cytochrome B5 Not available

Results

The apparent Ki value is presented in the table.
Additional study using TA1538 cell membrane fractions of P450 reductase found that (-)-epigallocatechin gallate inhibited this enzyme competitively with an apparent Ki value of 2.5 µM.

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

Experiments were conducted using TA1538 cell membrane fractions expressing P450 reductase and individual CYP isoforms.

CYP: 20 pmol/mL

In-house preparation

0.5 mL

15 min

NADPH regenerating system

Not available

Not available

1 µM

50 µM

9 . Percent inhibition of CYP2C9 by epicatechin gallate (id=NPDI-2KGgbg)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — not provided

diclofenac 1124300

epicatechin gallate

4'-hydroxydiclofenac

  • CYP2C9 4309227

Recombinant expression system Not available
Cytochrome B5 Not available

Results

Percent inhibition at 100 µM as estimated from Fig. 3 is presented.

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

Experiments were conducted using TA1538 cell membrane fractions expressing P450 reductase and individual CYP isoforms.

CYP: 20 pmol/mL

In-house preparation

0.25 mL

15 min

NADPH regenerating system

Not available

Not available

5 µM

0-100 µM

10 . Unnamed Experiment (id=NPDI-38xlLg)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — N/A

diclofenac 1124300

epigallocatechin gallate 19058494

4'-hydroxydiclofenac

  • CYP2C9 4309227

Recombinant expression system Not available
Cytochrome B5 Not available

Results

The apparent Ki value is presented in the table.
Additional study using TA1538 cell membrane fractions of P450 reductase found that (-)-epigallocatechin gallate inhibited this enzyme competitively with an apparent Ki value of 2.5 µM.

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

Experiments were conducted using TA1538 cell membrane fractions expressing P450 reductase and individual CYP isoforms.

CYP: 20 pmol/mL

In-house preparation

0.25 mL

15 min

NADPH regenerating system

Not available

Not available

5 µM

20 µM

11 . Percent inhibition of CYP3A4 by epicatechin gallate (id=NPDI-JGDRVA)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — not provided

midazolam 708298

epicatechin gallate

1'-hydroxymidazolam

  • CYP3A4 4306811

Recombinant expression system Not available
Cytochrome B5 Not available

Results

Percent inhibition at 100 µM as estimated from Fig. 3 is presented.

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

Experiments were conducted using TA1538 cell membrane fractions expressing P450 reductase and individual CYP isoforms.

CYP: 60 pmol/mL

In-house preparation

0.5 mL

5 min

NADPH regenerating system

Not available

Not available

10 µM

0-100 µM

12 . Unnamed Experiment (id=NPDI-Cuu5WA)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — N/A

midazolam 708298

epigallocatechin gallate 19058494

1'-hydroxymidazolam

  • CYP3A4 4306811

Recombinant expression system Not available
Cytochrome B5 Not available

Results

The apparent Ki value is presented in the table.
Additional study using TA1538 cell membrane fractions of P450 reductase found that (-)-epigallocatechin gallate inhibited this enzyme competitively with an apparent Ki value of 2.5 µM.

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

Experiments were conducted using TA1538 cell membrane fractions expressing P450 reductase and individual CYP isoforms.

CYP: 60 pmol/mL

In-house preparation

0.5 mL

5 min

NADPH regenerating system

Not available

Not available

10 µM

10 µM

13 . Percent inhibition of CYP1A1 by (-)-epicatechin (id=NPDI-pD4STA)

In Vitro Enzyme Inhibition Experiment

Negligible Inhibition was detected.  Cutoff used — not provided

7-ethoxycoumarin

(-)-epicatechin

coumarin 19008106

  • CYP1A1 4173297

Recombinant expression system Not available
Cytochrome B5 Not available

Results

Percent inhibition at 100 µM as estimated from Fig. 3 is presented.

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

Experiments were conducted using TA1538 cell membrane fractions expressing P450 reductase and individual CYP isoforms.

CYP: 20 pmol/mL

In-house preparation

0.5 mL

15 min

NADPH regenerating system

Not available

Not available

10 µM

0-100 µM