Ketoconazole inhibits the cellular uptake of anandamide via inhibition of FAAH at pharmacologically relevant concentrations

PLoS One. 2014 Jan 23;9(1):e87542. doi: 10.1371/journal.pone.0087542. eCollection 2014.

Abstract

Background: The antifungal compound ketoconazole has, in addition to its ability to interfere with fungal ergosterol synthesis, effects upon other enzymes including human CYP3A4, CYP17, lipoxygenase and thromboxane synthetase. In the present study, we have investigated whether ketoconazole affects the cellular uptake and hydrolysis of the endogenous cannabinoid receptor ligand anandamide (AEA).

Methodology/principal findings: The effects of ketoconazole upon endocannabinoid uptake were investigated using HepG2, CaCo2, PC-3 and C6 cell lines. Fatty acid amide hydrolase (FAAH) activity was measured in HepG2 cell lysates and in intact C6 cells. Ketoconazole inhibited the uptake of AEA by HepG2 cells and CaCo2 cells with IC50 values of 17 and 18 µM, respectively. In contrast, it had modest effects upon AEA uptake in PC-3 cells, which have a low expression of FAAH. In cell-free HepG2 lysates, ketoconazole inhibited FAAH activity with an IC50 value (for the inhibitable component) of 34 µM.

Conclusions/significance: The present study indicates that ketoconazole can inhibit the cellular uptake of AEA at pharmacologically relevant concentrations, primarily due to its effects upon FAAH. Ketoconazole may be useful as a template for the design of dual-action FAAH/CYP17 inhibitors as a novel strategy for the treatment of prostate cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amidohydrolases / antagonists & inhibitors*
  • Amidohydrolases / metabolism
  • Analysis of Variance
  • Arachidonic Acids / metabolism*
  • Arachidonic Acids / pharmacokinetics*
  • Caco-2 Cells
  • Dose-Response Relationship, Drug
  • Endocannabinoids / metabolism*
  • Endocannabinoids / pharmacokinetics*
  • Hep G2 Cells
  • Humans
  • Ketoconazole / pharmacology*
  • Polyunsaturated Alkamides / metabolism*
  • Polyunsaturated Alkamides / pharmacokinetics*
  • Receptor, Cannabinoid, CB2 / metabolism

Substances

  • Arachidonic Acids
  • Endocannabinoids
  • Polyunsaturated Alkamides
  • Receptor, Cannabinoid, CB2
  • Amidohydrolases
  • fatty-acid amide hydrolase
  • Ketoconazole
  • anandamide

Grant support

The authors thank the Swedish Science Council (Grant no. 12158, medicine) and the Research Funds of the Medical Faculty, Umeå University for financial support. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.