Goldenseal (Hydrastis canadensis)
Supplementation With Goldenseal (Hydrastis canadensis), but not Kava Kava (Piper methysticum), Inhibits Human CYP3A Activity In Vivo
The effects of goldenseal (Hydrastis canadensis) and kava kava (Piper methysticum) supplementation on human CYP3A activity were evaluated using midazolam (MDZ) as a phenotypic probe. Sixteen healthy volunteers were randomly assigned to receive either goldenseal or kava kava for 14 days. Each supplementation phase was followed by a 30-day washout period. MDZ (8 mg, per os) was administered before and after each phase, and pharmacokinetic parameters were determined using standard non-compartmental methods. Comparisons of pre- and post-supplementation MDZ pharmacokinetic parameters revealed significant inhibition of CYP3A by goldenseal (AUC(0–N), 107.9743.3 vs 175.3774.8 ng x h/ml; Cl/F/kg, 1.2670.59 vs 0.8170.45 l/h/kg; T1/2, 2.0170.42 vs 3.1571.12 h; Cmax, 50.6726.9 vs 71.2750.5 ng/ml). MDZ disposition was not affected by kava kava supplementation. These findings suggest that significant herb–drug interactions may result from the concomitant ingestion of goldenseal and CYP3A substrates.
In Vivo Interaction Study
Increased systemic exposure was detected.
- CYP3A4 4306811
Control is pre-goldenseal administration
Test is post-goldenseal administration
Data from Table 1/Table 2
|Sample||Compound measured||Value||Measurement||Study sequence||Additional information||N replicates|
Normal diet, and were not users of botanical dietary supplements; nor were they taking any prescription medications. All female subjects had a negative pregnancy test at baseline, and
0, 0.25, 0.50, 0.75, 1, 1.5, 2, 3, 4, 5, and 6 h
Drug or Natural Product Administration
8 mg with 240 mL of water
14 days administered 24h before the start of each supplementation/medication phase (baseline) and again on the last day of each phase.
three times daily
Nautre’s Resource Products
standardized to contain 24.1 mg isoquinoline alkaloids per capsule