title: Identification of Trypanocidal Activity for Known Clinical Compounds Using a New Trypanosoma cruzi Hit-Discovery Screening Cascade.
abstract: Chagas disease is a significant health problem in Latin America and the available treatments have significant issues in terms of toxicity and efficacy. There is thus an urgent need to develop new treatments either via a repurposing strategy or through the development of new chemical entities. A key first step is the identification of compounds with anti-Trypanosoma cruzi activity from compound libraries. Here we describe a hit discovery screening cascade designed to specifically identify hits that have the appropriate anti-parasitic properties to warrant further development. The cascade consists of a primary imaging-based assay followed by newly developed and appropriately scaled secondary assays to predict the cidality and rate-of-kill of the compounds. Finally, we incorporated a cytochrome P450 CYP51 biochemical assay to remove compounds that owe their phenotypic response to inhibition of this enzyme. We report the use of the cascade in profiling two small libraries containing clinically tested compounds and identify Clemastine, Azelastine, Ifenprodil, Ziprasidone and Clofibrate as molecules having appropriate profiles. Analysis of clinical derived pharmacokinetic and toxicity data indicates that none of these are appropriate for repurposing but they may represent suitable start points for further optimisation for the treatment of Chagas disease.
authors.affiliation: Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, University of Dundee, Dundee, United Kingdom.
authors.forename: Manu
authors.initials: M
authors.lastname: De Rycker
authors.affiliation: Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, University of Dundee, Dundee, United Kingdom.
authors.forename: John
authors.initials: J
authors.lastname: Thomas
authors.affiliation: Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, University of Dundee, Dundee, United Kingdom.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Riley
authors.affiliation: GlaxoSmithKline, Biological Sciences, Medicines Research Centre, Stevenage, Hertfordshire, United Kingdom.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Brough
authors.affiliation: GlaxoSmithKline, Diseases of the Developing World, Parque Tecnologico de Madrid, Servero Ochoa, Madrid, Spain.
authors.forename: Tim J
authors.initials: TJ
authors.lastname: Miles
authors.affiliation: Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, University of Dundee, Dundee, United Kingdom.
authors.forename: David W
authors.initials: DW
authors.lastname: Gray
mesh_terms: D000818:Animals; D058633:Antipyretics / Q000494:pharmacology; D002460:Cell Line; D014355:Chagas Disease / Q000188:drug therapy / Q000469:parasitology; D002522:Chlorocebus aethiops; D002974:Clemastine / Q000494:pharmacology; D004353:Drug Evaluation, Preclinical; D058492:Drug Repositioning; D057166:High-Throughput Screening Assays; D021261:Parasitic Sensitivity Tests; D058886:Sterol 14-Demethylase; D014344:Trypanocidal Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D014349:Trypanosoma cruzi / Q000187:drug effects* / Q000254:growth & development / Q000648:ultrastructure; D014709:Vero Cells
chemical_list: D058633:Antipyretics; D014344:Trypanocidal Agents; D002974:Clemastine; D058886:Sterol 14-Demethylase