In silico activity profiling reveals the mechanism of action of antimalarials discovered in a high-throughput screen

Proc Natl Acad Sci U S A. 2008 Jul 1;105(26):9059-64. doi: 10.1073/pnas.0802982105. Epub 2008 Jun 25.


The growing resistance to current first-line antimalarial drugs represents a major health challenge. To facilitate the discovery of new antimalarials, we have implemented an efficient and robust high-throughput cell-based screen (1,536-well format) based on proliferation of Plasmodium falciparum (Pf) in erythrocytes. From a screen of approximately 1.7 million compounds, we identified a diverse collection of approximately 6,000 small molecules comprised of >530 distinct scaffolds, all of which show potent antimalarial activity (<1.25 microM). Most known antimalarials were identified in this screen, thus validating our approach. In addition, we identified many novel chemical scaffolds, which likely act through both known and novel pathways. We further show that in some cases the mechanism of action of these antimalarials can be determined by in silico compound activity profiling. This method uses large datasets from unrelated cellular and biochemical screens and the guilt-by-association principle to predict which cellular pathway and/or protein target is being inhibited by select compounds. In addition, the screening method has the potential to provide the malaria community with many new starting points for the development of biological probes and drugs with novel antiparasitic activities.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antimalarials / analysis*
  • Antimalarials / chemistry
  • Antimalarials / pharmacology*
  • Antimalarials / therapeutic use
  • Cluster Analysis
  • Computational Biology*
  • Drug Evaluation, Preclinical
  • Drug Resistance / drug effects
  • Folic Acid Antagonists / analysis
  • Folic Acid Antagonists / chemistry
  • Folic Acid Antagonists / pharmacology
  • Malaria / drug therapy
  • Models, Molecular
  • Parasites / drug effects
  • Plasmodium falciparum / drug effects
  • Plasmodium falciparum / enzymology
  • Reproducibility of Results
  • Structure-Activity Relationship
  • Tetrahydrofolate Dehydrogenase / chemistry


  • Antimalarials
  • Folic Acid Antagonists
  • Tetrahydrofolate Dehydrogenase