Pharmacokinetic herb-drug interactions (part 1): origins, mechanisms, and the impact of botanical dietary supplements

Planta Med. 2012 Sep;78(13):1478-89. doi: 10.1055/s-0031-1298273. Epub 2012 Feb 9.


Phytochemicals have been components of man's diet for millennia and are believed to have played a significant role in steering the functional development of xenobiotic metabolizing enzymes and transporters within the human gastrointestinal tract. Only recently, however, have plant secondary metabolites been recognized as modulators of human drug disposition. Despite exposure to thousands of structurally diverse dietary phytochemicals, only a few appear to significantly modulate human drug metabolizing enzymes and transporters. In some instances, these interactions may have beneficial effects like cancer prevention, whereas others may dramatically affect the pharmacokinetics of concomitantly administered drugs. In today's global economy, the opportunity for exposure to more exotic phytochemicals is significantly enhanced. Formulated as concentrated phytochemical extracts, botanical dietary supplements are vehicles for a host of plant secondary metabolites rarely encountered in the normal diet. When taken with conventional medications, botanical dietary supplements may give rise to clinically significant herb-drug interactions. These interactions stem from phytochemical-mediated induction and/or inhibition of human drug metabolizing enzymes and transporters.

Publication types

  • Review

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Animals
  • Chemistry, Pharmaceutical
  • Cytochrome P-450 Enzyme System / drug effects*
  • Cytochrome P-450 Enzyme System / metabolism*
  • Dietary Supplements
  • Drug Contamination
  • Drug Synergism
  • Herb-Drug Interactions*
  • Humans
  • Membrane Transport Proteins / metabolism
  • Pharmacogenetics
  • Pharmacokinetics*
  • Plant Extracts / pharmacology
  • Plant Preparations / chemistry
  • Plant Preparations / pharmacology*
  • Transferases / metabolism


  • Membrane Transport Proteins
  • Plant Extracts
  • Plant Preparations
  • Adenosine Triphosphate
  • Cytochrome P-450 Enzyme System
  • Transferases