Goldenseal (Hydrastis canadensis) 43525850
Human Cytochrome P450 Inhibition and Metabolic-Intermediate Complex Formation By Goldenseal Extract and Its Methylenedioxyphenyl Components CSV JSON

The concurrent use of herbal medicinals with prescription and over-the-counter drugs carries a risk for unanticipated adverse drug-botanical pharmacokinetic interactions, particularly as a result of cytochrome P450 (P450) inhibition. Extracts of goldenseal (Hydrastis canadensis) containing approximately equal concentrations ( approximately 17 mM) of two methylenedioxyphenyl alkaloids, berberine and hydrastine, inhibited with increasing potency (CYP2C9) diclofenac 4'-hydroxylation, (CYP2D6) bufuralol 1'-hydroxylation, and (CYP3A4) testosterone 6beta-hydroxylation activities in human hepatic microsomes. The inhibition of testosterone 6beta-hydroxylation activity was noncompetitive with an apparent Ki of 0.11% extract. Of the methylenedioxyphenyl alkaloids, berberine (IC50 = 45 microM) was the more inhibitory toward bufuralol 1'-hydroxylation and hydrastine (IC50 approximately 350 microM for both isomers), toward diclofenac 4'-hydroxylation. For testosterone 6beta-hydroxylation, berberine was the least inhibitory component (IC50 approximately 400 microM). Hydrastine inhibited testosterone 6beta-hydroxylation with IC50 values for the (+)- and (-)-isomers of 25 and 30 microM, respectively. For (-)-hydrastine, an apparent Ki value of 18 microM without preincubation and an NADPH-dependent mechanism-based inhibition with a kinactivation of 0.23 min(-1) and a KI of approximately 110 microM were determined. Cytochrome P450 metabolic-intermediate (MI) complex formation could be demonstrated for both hydrastine isomers. With expressed P450 isoforms, hydrastine formed a P450 MI complex with CYP2C9, CYP2D6, and CYP3A4. Coexpression of cytochrome b5 with the P450 isoforms enhanced the rate but not the extent of P450 MI complex formation.

1 . 2D6 Inhibition by (-) Hydrastine (id=NPDI-UaWFPQ)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — not specified

bufuralol

(-)-beta-hydrastine

1'-Hydroxybufuralol

  • CYP2D6 4173631

Cell fraction Pooled human liver microsomes -7999662

Results

Fig 4b at 1000 μM

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

1 mg/mL

Commercially available

30 min

NADPH

25 μ􏱂M

No NADPH with precipitant

10, 100, and 1,000 μ􏱂M

2 . 2D6 Inhibition by Berberine (id=NPDI-LNDazQ)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — Not Specified

bufuralol

Berberine 19012197

1'-Hydroxybufuralol

  • CYP2D6 4173631

Cell fraction Pooled human liver microsomes -7999662

Results

Estimate at 500 μM Fig 4b

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

1 mg/mL

Commercially available

30 min

NADPH

25 μ􏱂M

No NADPH with precipitant

10, 100, and 500 μ􏱂M

3 . 2D6 Inhibition by GS Extract (id=NPDI-qzY27Q)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — not specified

bufuralol

1'-Hydroxybufuralol

  • CYP2D6 4173631

Cell fraction Pooled human liver microsomes -7999662

Results

Fig 2 Estimate

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

1 mg/mL

Commercially available

30 min

NADPH

25 μ􏱂M

No NADPH with precipitant

4 . 2D6 Inhibition by (+) Hydrastine (id=NPDI-w-6ghw)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — not specified

bufuralol

hydrastine

1'-Hydroxybufuralol

  • CYP2D6 4173631

Cell fraction Pooled human liver microsomes -7999662

Results

Fig 4b (+) hydrastine at 1000 μM

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

1 mg/mL

Commercially available

30 min

NADPH

25 μ􏱂M

No NADPH with precipitant

10, 100, and 1,000 μ􏱂M

5 . 2C9 Inhibition by (-) Hydrastine (id=NPDI-wdarow)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — not specified

diclofenac 1124300

(-)-beta-hydrastine

4'-hydroxydiclofenac

  • CYP2C9 4309227

Cell fraction Pooled human liver microsomes -7999662

Results

Fig 4c at 1000 μM

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

0.5 mg/mL

Commercially available

30 min

NADPH

100 μ􏱂M

No NADPH with precipitant

10, 100, and 1000 μ􏱂M

6 . 2C9 Inhibition by Berberine (id=NPDI-iSHQYQ)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — not specified

diclofenac 1124300

Berberine 19012197

4'-hydroxydiclofenac

  • CYP2C9 4309227

Cell fraction Pooled human liver microsomes -7999662

Results

Fig 4c estimation at 500 μM

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

0.5 mg/mL

Commercially available

30 min

NADPH

100 μ􏱂M

No NADPH with precipitant

10, 100, and 500 􏱂μ􏱂M

7 . 2C9 Inhibition by GS Extract (id=NPDI--K80vw)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — not specified

diclofenac 1124300

4'-hydroxydiclofenac

  • CYP2C9 4309227

Cell fraction Pooled human liver microsomes -7999662

Results

Fig 2 difference estimate at 1% of extract

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

0.5 mg/mL

Commercially available

30 min

NADPH

100 μ􏱂M

No NADPH with precipitant

8 . 2C9 Inhibition by (+) Hydrastine (id=NPDI-3M10oA)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — not specified

diclofenac 1124300

hydrastine

4'-hydroxydiclofenac

  • CYP2C9 4309227

Cell fraction Pooled human liver microsomes -7999662

Results

Fig 4c at 1000 μM

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

0.5 mg/mL

Commercially available

30 min

NADPH

100 μ􏱂M

No NADPH with precipitant

10, 100, and 1000 μ􏱂M

9 . 3A4 Inhibition by (-) Hydrastine (id=NPDI-CDvKlQ)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — not specified

testosterone

(-)-beta-hydrastine

6beta-Hydroxytestosterone

  • CYP3A4 4306811

Cell fraction Pooled human liver microsomes -7999662

Results

fig 4a at 1000 μM

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

0.2 mg/mL

Commercially available

15 min

NADPH

200 μ􏱂M

No NADPH with precipitant

10, 100, and 1000 μ􏱂M

10 . 3A4 Inhibition by Berberine (id=NPDI-_D6yiA)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — not specified

testosterone

Berberine 19012197

6beta-Hydroxytestosterone

  • CYP3A4 4306811

Cell fraction Pooled human liver microsomes -7999662

Results

Estimate at 500 μM (Fig 4a)

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

0.2 mg/mL

Commercially available

15 min

NADPH

200 μ􏱂M

No NADPH with precipitant

10, 100, and 500 μ􏱂M

11 . 3A4 Inhibition by GS Extract (id=NPDI-OCQ06Q)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — not specified

testosterone

6beta-Hydroxytestosterone

  • CYP3A4 4306811

Cell fraction Pooled human liver microsomes -7999662

Results

Fig 2 at 1%

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

0.2 mg/mL

Commercially available

15 min

NADPH

200 μ􏱂M

No NADPH with precipitant

12 . 3A4 Inhibition by (+) Hydrastine (id=NPDI-39rhWg)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — not specified

testosterone

hydrastine

6beta-Hydroxytestosterone

  • CYP3A4 4306811

Cell fraction Pooled human liver microsomes -7999662

Results

Fig 4a at 1000 μM

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

0.2 mg/mL

Commercially available

15 min

NADPH

200 μ􏱂M

No NADPH with precipitant

10, 100, and 1000 μ􏱂M