In vitro interactions of water-soluble garlic components with human cytochromes p450.
Eight water-soluble components of aged garlic extract were evaluated to assess their potential to inhibit the activity of human cytochrome-P450 (CYP) enzymes. The in vitro model consisted of human liver microsomes with index reactions chosen to profile the activity of the following six CYP isoforms: CYP1A2, 2B6, 2C9, 2C19, 2D6, and 3A. With only 2 exceptions, none of the 8 garlic components produced >50% inhibition even at high concentrations (100 micromol/L). S-methyl-L-cysteine and S-allyl-L-cysteine at 100 micromol/L produced modest inhibition of CYP3A, reducing activity to 20-40% of control. However available clinical evidence does not indicate CYP3A inhibition in vivo. The findings suggest that drug interactions involving inhibition of CYP3A enzymes by aged garlic extract are very unlikely.
Greenblatt
David J
DJ
Department of Pharmacology and Experimental Therapeutics, Tufts University School of Medicine and Tufts-New England Medical Center, Boston, MA, USA. dj.greenblatt@tufts.edu
Leigh-Pemberton
Richard A
RA
von Moltke
Lisa L
LL
D016642:Bupropion / Q000494:pharmacology; D003577:Cytochrome P-450 Enzyme System / Q000187:drug effects / Q000378:metabolism*; D003915:Dextromethorphan / Q000494:pharmacology; D005480:Flurbiprofen / Q000494:pharmacology; D005737:Garlic; D006801:Humans; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000378:metabolism; D007700:Kinetics; D010615:Phenacetin / Q000494:pharmacology; D010936:Plant Extracts / Q000494:pharmacology*; D014229:Triazolam / Q000494:pharmacology
D007527:Isoenzymes; D010936:Plant Extracts; D016642:Bupropion; D014229:Triazolam; D005480:Flurbiprofen; D003915:Dextromethorphan; D003577:Cytochrome P-450 Enzyme System; D010615:Phenacetin