Supplementation With Goldenseal (Hydrastis canadensis), but not Kava Kava (Piper methysticum), Inhibits Human CYP3A Activity In Vivo Academic Article uri icon


  • 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-infinity), 107.9+/-43.3 vs 175.3+/-74.8 ng x h/ml; Cl/F/kg, 1.26+/-0.59 vs 0.81+/-0.45 l/h/kg; T(1/2), 2.01+/-0.42 vs 3.15+/-1.12 h; Cmax, 50.6+/-26.9 vs 71.2+/-50.5 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.

altmetric score

  • 10

author list (cited authors)

  • Gurley, B. J., Swain, A., Hubbard, M. A., Hartsfield, F., Thaden, J., Williams, D. K., Gentry, W. B., & Tong, Y.

citation count

  • 71

publication date

  • May 2007