Cannabis L. (Cannabis sativa)
Comparison in the in vitro inhibitory effects of major phytocannabinoids and polycyclic aromatic hydrocarbons contained in marijuana smoke on cytochrome P450 2C9 activity. CSV JSON

Inhibitory effects of Δ⁹-tetrahydrocannabinol (Δ⁹-THC), cannabidiol (CBD), and cannabinol (CBN), the three major constituents in marijuana, and polycyclic aromatic hydrocarbons (PAHs) contained in marijuana smoke on catalytic activity of human cytochrome P450 (CYP) 2C9 were investigated. These phytocannabinoids concentration-dependently inhibited S-warfarin 7-hydroxylase and diclofenac 4'-hydroxylase activities of human liver microsomes (HLMs) and recombinant CYP2C9 (rCYP2C9). In contrast, none of the twelve PAHs including benz[a]anthracene and benzo[a]pyrene exerted substantial inhibition (IC₅₀ > 10 µM). The inhibitory potentials of Δ⁹-THC (Ki = 0.937-1.50 µM) and CBN (Ki = 0.882-1.29 µM) were almost equivalent regardless of the enzyme sources used, whereas the inhibitory potency of CBD (Ki > = 0.954-9.88 µM) varied depending on the enzyme sources and substrates used. Δ⁹-THC inhibited both S-warfarin 7-hydroxylase and diclofenac 4'-hydroxylase activities of HLMs and rCYP2C9 in a mixed manner. CBD and CBN competitively inhibited the activities of HLMs and rCYP2C9, with the only notable difference being that CBD and CBN exhibited mixed-type inhibitions against diclofenac 4'-hydroxylation and S-warfarin 7-hydroxylation, respectively, by rCYP2C9. None of Δ⁹-THC, CBD, and CBN exerted metabolism-dependent inhibition. These results indicated that the three major phytocannabinoids but not PAHs contained in marijuana smoke potently inhibited CYP2C9 activity and that these cannabinoidscan be characterized as direct inhibitors for CYP2C9.

PMID: 22166891

22166891

1 . rCYP2C9: CBD-warfarin (id=NPDI-P2rdYg)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — Not specified

(s)-warfarin

cannabidiol (cbd)

7-hydroxywarfarin

  • CYP2C9 4309227

Recombinant expression system Baculovirus-insect cells
Cytochrome B5 No

Results

Tables 2, 3, and 4
IC50 preincubation time recorded at 20 min

Sample Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

6 pmol

Commercially available

200 μL

20 min

MgCl2
NADPH regenerating system

5 min

NADPH with precipitant

2 . pHLM: CBD-warfarin (id=NPDI-XouN0Q)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — Not specified

(s)-warfarin

cannabidiol (cbd)

7-hydroxywarfarin

  • CYP2C9 4309227

Cell fraction Pooled human liver microsomes -7999662

Results

Tables 2, 3, and 4.
IC50 pre-incubation recorded at 20 min

Sample Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

20 μg

Commercially available

200 μL

20 min

MgCl2
NADPH regenerating system

5 min

NADPH with precipitant

3 . iHLMs: CBD-warfarin (id=NPDI-dvyC1w)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — Not specified

(s)-warfarin

cannabidiol (cbd)

7-hydroxywarfarin

  • CYP2C9 4309227

Cell fraction Individual human liver microsomes

Results

Tables 2 and 3

Sample Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

50 μg

Commercially available

200 μL

20 min

MgCl2
NADPH regenerating system

5 min

NADPH with precipitant

4 . rCYP2C9: CBN-warfarin (id=NPDI-wt2yDg)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — Not specified

(s)-warfarin

cannabinol (cbn)

7-hydroxywarfarin

  • CYP2C9 4309227

Recombinant expression system Baculovirus-insect cells
Cytochrome B5 No

Results

Tables 2, 3, and 4
IC50 preincubation time recorded at 20 min

Sample Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

6 pmol

Commercially available

200 μL

20 min

MgCl2
NADPH regenerating system

5 min

NADPH with precipitant

5 . pHLM: CBN-warfarin (id=NPDI-mGu2ew)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — Not specified

(s)-warfarin

cannabinol (cbn)

7-hydroxywarfarin

  • CYP2C9 4309227

Cell fraction Pooled human liver microsomes -7999662

Results

Tables 2, 3, and 4.
IC50 pre-incubation recorded at 20 min

Sample Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

Commercially available

20 min

MgCl2
NADPH regenerating system

5 min

NADPH with precipitant

6 . iHLM: CBN-warfarin (id=NPDI-ZNPhvw)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — Not specified

(s)-warfarin

cannabinol (cbn)

7-hydroxywarfarin

  • CYP2C9 4309227

Cell fraction Individual human liver microsomes

Results

Tables 2 and 3

Sample Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

50 μg

Commercially available

200 μL

20 min

MgCl2
NADPH regenerating system

5 min

NADPH with precipitant

7 . rCYP2C9: THC-warfarin (id=NPDI-59dZ4A)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — Not specified

(s)-warfarin

7-hydroxywarfarin

  • CYP2C9 4309227

Recombinant expression system Baculovirus-insect cells
Cytochrome B5 No

Results

Tables 2, 3, and 4
IC50 preincubation time recorded at 20 min

Sample Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

6 pmol

Commercially available

200 μL

20 min

MgCl2
NADPH regenerating system

5 min

NADPH with precipitant

8 . iHLM: THC-warfarin (id=NPDI-vUechg)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — Not specified

(s)-warfarin

7-hydroxywarfarin

  • CYP2C9 4309227

Cell fraction Individual human liver microsomes

Results

Tables 2 and 3

Sample Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

50 μg

Commercially available

200 μL

20 min

MgCl2
NADPH regenerating system

5 min

NADPH with precipitant

9 . pHLM: THC-warfarin (id=NPDI-jZO6oQ)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — Not specified

(s)-warfarin

7-hydroxywarfarin

  • CYP2C9 4309227

Cell fraction Pooled human liver microsomes -7999662

Results

Tables 2, 3, and 4.
IC50 pre-incubation recorded at 20 min

Sample Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

20 μg

Commercially available

200 μL

20 min

MgCl2
NADPH regenerating system

5 min

NADPH with precipitant

10 . rCYP2C9: CBD-diclofenac (id=NPDI-LKS7Ow)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — Not specified

diclofenac 1124300

cannabidiol (cbd)

4'-hydroxydiclofenac

  • CYP2C9 4309227

Recombinant expression system Baculovirus-insect cells
Cytochrome B5 No

Results

Tables 2 and 3

Sample Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

2 pmol

Commercially available

250 μL

20 min

MgCl2
NADPH regenerating system

5 min

NADPH with precipitant

11 . iHLM: CBD-diclofenac (id=NPDI-Fqa3JA)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — Not specified

diclofenac 1124300

cannabidiol (cbd)

4'-hydroxydiclofenac

  • CYP2C9 4309227

Cell fraction Individual human liver microsomes

Results

Tables 2 and 3

Sample Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

50 μg

Commercially available

250 μL

20 min

MgCl2
NADPH regenerating system

5 min

NADPH with precipitant

12 . rCYP2C9: CBN-diclofenac (id=NPDI-KqafWg)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — Not specified

diclofenac 1124300

cannabinol (cbn)

4'-hydroxydiclofenac

  • CYP2C9 4309227

Recombinant expression system Baculovirus-insect cells
Cytochrome B5 No

Results

Tables 2 and 3

Sample Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

2 pmol

Commercially available

250 μL

20 min

MgCl2
NADPH regenerating system

5 min

NADPH with precipitant

13 . iHLM: CBN-diclofenac (id=NPDI-V1SemA)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — Not specified

diclofenac 1124300

cannabinol (cbn)

4'-hydroxydiclofenac

  • CYP2C9 4309227

Cell fraction Individual human liver microsomes

Results

Tables 2 and 3

Sample Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

50 μg

Commercially available

250 μL

20 min

MgCl2
NADPH regenerating system

5 min

NADPH with precipitant

14 . rCYP2C9: THC-diclofenac (id=NPDI-bM6NOQ)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — Not specified

diclofenac 1124300

4'-hydroxydiclofenac

  • CYP2C9 4309227

Recombinant expression system Baculovirus-insect cells
Cytochrome B5 No

Results

Tables 2 and 3

Sample Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

2 pmol

Commercially available

250 μL

20 min

MgCl2
NADPH regenerating system

5 min

NADPH with precipitant

15 . iHLM: THC-diclofenac (id=NPDI-Jb4JFA)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — Not specified

diclofenac 1124300

4'-hydroxydiclofenac

  • CYP2C9 4309227

Cell fraction Individual human liver microsomes

Results

Tables 2 and 3

Sample Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

50 μg

Commercially available

250 μL

20 min

MgCl2
NADPH regenerating system

5 min

NADPH with precipitant