Goldenseal (Hydrastis canadensis)
Time-Dependent Inhibition of CYP2C19 by Isoquinoline Alkaloids: In Vitro and In Silico Analysis CSV JSON

The cytochrome P450 2C19 (CYP2C19) enzyme plays an important role in the metabolism of many commonly used drugs. Relatively little is known about CYP2C19 inhibitors, including compounds of natural origin, which could inhibit CYP2C19, potentially causing clinically relevant metabolism-based drug interactions. We evaluated a series (N = 49) of structurally related plant isoquinoline alkaloids for their abilities to interact with CYP2C19 enzyme using in vitro and in silico methods. We examined several common active alkaloids found in herbal products such as apomorphine, berberine, noscapine, and papaverine, as well as the previously identified mechanism-based inactivators bulbocapnine, canadine, and protopine. The IC50 values of the alkaloids ranged from 0.11 to 210 mM, and 42 of the alkaloids were confirmed to be time-dependent inhibitors of CYP2C19. Molec- ular docking and three-dimensional quantitative structure-activity relationship analysis revealed key interactions of the potent inhibitors with the enzyme active site. We constructed a comparative molecular field analysis model that was able to predict the inhibitory potency of a series of independent test molecules. This study revealed that many of these isoquinoline alkaloids do have the potential to cause clinically relevant drug interactions. These results highlight the need for studying more profoundly the potential interactions between drugs and herbal products. When further refined, in silico methods can be useful in the high-throughput prediction of P450 inhibitory potential of pharmaceutical compounds.

PMID: 26400396


1 . CYP2C19 Inhibition by Berberine (id=NPDI-roGv8w)

In Vitro Enzyme Inhibition Experiment

Negligible Inhibition was detected.  Cutoff used — TDI ≥1.5 fold decrease compared to preincubation


berberine 19012197


  • CYP2C19 4311137

Recombinant expression system Baculovirus-insect cells
Cytochrome B5 Co-expressed


Table 1

Sample Compound measured Value Measurement Study sequence Additional information N replicates

Experimental Conditions

1.5 pmol

Commercially available

NADPH regenerating system

1 μM

30 min

NADPH with precipitant