Screening of the Pathogen Box for inhibitors with dual efficacy against < i > Giardia lamblia < /i > and < i > Cryptosporidium parvum < /i >

by Kelly M. Hennessey, Ilse C. Rogiers, Han-Wei Shih, Matthew A. Hulverson, Ryan Choi, Molly C. McCloskey, Grant R. Whitman, Lynn K. Barrett, Ethan A. Merritt, Alexander R. Paredez, Kayode K. Ojo There is need for a more efficient cell-based assay amenable to high-throughput drug screening againstGiardia lamblia. Here, we report the development of a screening method utilizingG.lamblia engineered to express red-shifted firefly luciferase. Parasite growth and replication were quantified using D-luciferin as a substrate in a bioluminescent read-out platform. This assay was validated for reproducibility and reliability against the Medicines for Malaria Venture (MMV) Pathogen Box compounds. ForG.lamblia, forty-three compounds showed ≥ 75% inhibition of parasite growth in the initial screen (16 μM), with fifteen showing ≥ 95% inhibition. The Pathogen Box was also screened against Nanoluciferase expressing (Nluc)C.parvum, yielding 85 compounds with ≥ 75% parasite growth inhibition at 10 μM, with six showing ≥ 95% inhibition. A representative set of seven compounds with activity against both parasites were further analyzed to determine the effective concentration that causes 50% growth inhibition (EC50) and cytotoxicity against mammalian HepG2 cells. Four of the seven compounds were previously known to be effective in treating eitherGiardia orCryptosporidium. The remaining three shared no obvious chemical similarity with any previously characterized anti-parasite diarrheal...
Source: PLoS Neglected Tropical Diseases - Category: Tropical Medicine Authors: Source Type: research