Faculty and Student Publications
Document Type
Article
Publication Date
2-1-2019
Abstract
Copyright © 2019 Hamerly, Tweedell, Hritzo, Nyasembe, Tekwani, Nanayakkara, Walker and Dinglasan. Malaria is a major global health threat, with nearly half the world's population at risk of infection. Given the recently described delayed clearance of parasites by artemisinincombined therapies, new antimalarials are needed to facilitate the global effort toward elimination and eradication. NPC1161 is an 8-aminoquinoline that is derived from primaquine with an improved therapeutic profile compared to the parent compound. The (R)-(-) enantiomer (NPC1161B) has a lower effective dose that results in decreased toxic side effects such as hemolysis compared to the (S)-(+)-enantiomer, making it a promising compound for consideration for clinical development. We explored the effect of NPC1161B on Plasmodium falciparum oocyst and sporozoite development to evaluate its potential transmission-blocking activity viz. its ability to cure mosquitoes of an ongoing infection. When mosquitoes were fed NPC1161B 4 days after P. falciparum infection, we observed that total oocyst numbers were not affected by NPC1161B treatment. However, the sporozoite production capacity of the oocysts was impaired, and salivary gland sporozoite infections were completely blocked, rendering the mosquitoes non-infectious. Importantly, NPC1161B did not require prior liver metabolism for its efficacy as is required in mammalian systems, suggesting that an alternative metabolite is produced in the mosquito that is active against the parasite. We performed liquid chromatography-mass spectrometry (LC-MS)/MS analysis of methanol extracts from the midguts of mosquitoes fed on an NPC1161B (434.15 m/z)-treated blood meal and identified a compound with a mass of 520.2 m/z, likely a conjugate of NPC1161B or an oxidized metabolite. These findings establish NPC1161B, and potentially its metabolites, as transmission-blocking candidates for the treatment of P. falciparum.
Relational Format
journal article
Recommended Citation
Lawrence, L., Cottrill, A., Valluri, A., Marenzi, G., Denning, K., Valluri, J., Claudio, P., & Day, J. (2019). Minimally Manipulative Method for the Expansion of Human Bone Marrow Mesenchymal Stem Cells to Treat Osseous Defects. International Journal of Molecular Sciences, 20(3), 612. https://doi.org/10.3390/ijms20030612
DOI
10.3390/ijms20030612