Goldenseal (Hydrastis canadensis) 43525850
Effects of Herbal Products and their Constituents on Human Cytochrome P4502E1 Activity CSV JSON

Ethanolic extracts from fresh Echinacea purpurea and Spilanthes acmella and dried Hydrastis canadensis were examined with regard to their ability to inhibit cytochrome P4502E1 mediated oxidation of p-nitrophenol in vitro. In addition, individual constituents of these extracts, including alkylamides from E. purpurea and S. acmella, caffeic acid derivatives from E. purpurea, and several of the major alkaloids from H. canadensis, were tested for inhibition using the same assay. H. canadensis (goldenseal) was a strong inhibitor of the P4502E1, and the inhibition appeared to be related to the presence of the alkaloids berberine, hydrastine and canadine in the extract. These compounds inhibited 2E1 with KI values ranging from 2.8 μM for hydrastine to 18 μM for berberine. The alkylamides present in E. purpurea and S. acmella also showed significant inhibition at concentrations as low as 25 μM, whereas the caffeic acid derivatives had no effect. Commercial green tea preparations, along with four of the individual tea catechins, were also examined and were found to have no effect on the activity of P4502E1.

PMID: 17658211

17658211

1 . CYP2E1 Inhibition by Berberine (id=NPDI-Wkqo4w)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — not specified

p-nitrophenol

berberine 19012197

4-nitrophenyl sulfate

  • CYP2E1 4173608

Cell fraction Pooled human liver microsomes -7999662

Results

Table 3
n and significance not indicated

Sample Compound measured Value Measurement Study sequence Additional information N replicates

Experimental Conditions

0.5 mL

NADPH

0.020 mM

20 min

NADPH with precipitant

4.0 μM

2 . CYP2E1 Inhibition by GS root extract (id=NPDI-jjfDSA)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — not specified

p-nitrophenol

4-nitrophenyl sulfate

  • CYP2E1 4173608

Cell fraction Pooled human liver microsomes -7999662

Results

Table 3 - n is not indicated

Sample Compound measured Value Measurement Study sequence Additional information N replicates

Experimental Conditions

0.5 mL

NADPH

0.020 mM

20 min

NADPH with precipitant

3 . 2E1 Inhibition by Hydrastine (id=NPDI-aGqWbw)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — not specified

p-nitrophenol

hydrastine

4-nitrophenyl sulfate

  • CYP2E1 4173608

Cell fraction Pooled human liver microsomes -7999662

"hydrastine being most potent [inhibitor]"

Results

Table 3
n and significance not indicated

Sample Compound measured Value Measurement Study sequence Additional information N replicates

Experimental Conditions

0.5 mL

NADPH

0.020 mM

20 min

NADPH with precipitant

4.0 μM