Metabolism of (R)-Praziquantel versus the Activation of a Parasite Transient Receptor Potential Melastatin Ion Channel

ChemMedChem. 2023 Sep 15;18(18):e202300140. doi: 10.1002/cmdc.202300140. Epub 2023 Jun 15.


Praziquantel (PZQ) is an essential anthelmintic drug recently established to be an activator of a Transient Receptor Potential Melastatin (TRPMPZQ ) ion channel in trematode worms. Bioinformatic, mutagenesis and drug metabolism work indicate that the cyclohexyl ring of PZQ is a key pharmacophore for activation of trematode TRPMPZQ , as well as serving as the primary site of oxidative metabolism which results in PZQ being a short-lived drug. Based on our recent findings, the hydrophobic cleft in schistosome TRPMPZQ defined by three hydrophobic residues surrounding the cyclohexyl ring has little tolerance for polarity. Here we evaluate the in vitro and in vivo activities of PZQ analogues with improved metabolic stability relative to the challenge of maintaining activity on the channel. Finally, an estimation of the respective contribution to the overall activity of both the parent and the main metabolite of PZQ in humans is reported.

Keywords: metabolite; praziquantel; schistosomiasis; structure-activity relationships; transient receptor potential melastatin.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Anthelmintics* / pharmacology
  • Anthelmintics* / therapeutic use
  • Humans
  • Parasites*
  • Praziquantel / chemistry
  • Praziquantel / pharmacology
  • Schistosoma mansoni
  • TRPM Cation Channels*
  • Transient Receptor Potential Channels*


  • Praziquantel
  • Transient Receptor Potential Channels
  • TRPM Cation Channels
  • Anthelmintics