A High-Throughput Phenotypic Screen of the 'Pandemic Response Box' Identifies a Quinoline Derivative with Significant Anthelmintic Activity

Parasitic nematodes cause diseases in livestock animals and major economic losses to the agricultural industry worldwide. Nematodes of the order Strongylida, including Haemonchus contortus, are particularly important. The excessive use of anthelmintic compounds to treat infections and disease has led to widespread resistance to these compounds in nematodes, such that there is a need for new anthelmintics with distinctive mechanisms of action. With a focus on discovering new anthelmintic entities, we screened 400 chemically diverse compounds within the 'Pandemic Response Box' (from Medicines for Malaria Venture, MMV) for activity against H. contortus and its free-living relative, Caenorhabditis elegans-a model organism. Using established phenotypic assays, test compounds were evaluated in vitro for their ability to inhibit the motility and/or development of H. contortus and C. elegans. Dose-response evaluations identified a compound, MMV1581032, that significantly the motility of H. contortus larvae (IC50 = 3.4 +/- 1.1 mu M) and young adults of C. elegans (IC50 = 7.1 +/- 4.6 mu M), and the development of H. contortus larvae (IC50 = 2.2 +/- 0.7 mu M). The favourable characteristics of MMV1581032, such as suitable physicochemical properties and an efficient, cost-effective pathway to analogue synthesis, indicates a promising candidate for further evaluation as a nematocide. Future work will focus on a structure-activity relationship investigation of this chemical scaffold, a toxicity assessment of potent analogues and a mechanism/mode of action investigation.

Automated summary

Parasitic nematodes cause economic losses in the agricultural industry and the widespread resistance to anthelmintic compounds highlights the need for new treatments. In this study, a screening of 400 compounds led to the discovery of MMV1581032, which exhibited significant inhibition of the motility and development of Haemonchus contortus and Caenorhabditis elegans. MMV1581032 has favorable characteristics and promising potential as a nematocide.