Antimalarial activity of primaquine operates via a two-step biochemical relay
Author(s)March, Sandra; Miller, Alex B.; Bhatia, Sangeeta N.
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Primaquine (PQ) is an essential antimalarial drug but despite being developed over 70 years ago, its mode of action is unclear. Here, we demonstrate that hydroxylated-PQ metabolites (OH-PQm) are responsible for efficacy against liver and sexual transmission stages of Plasmodium falciparum. The antimalarial activity of PQ against liver stages depends on host CYP2D6 status, whilst OH-PQm display direct, CYP2D6-independent, activity. PQ requires hepatic metabolism to exert activity against gametocyte stages. OH-PQm exert modest antimalarial efficacy against parasite gametocytes; however, potency is enhanced ca.1000 fold in the presence of cytochrome P450 NADPH:oxidoreductase (CPR) from the liver and bone marrow. Enhancement of OH-PQm efficacy is due to the direct reduction of quinoneimine metabolites by CPR with the concomitant and excessive generation of H2O2, leading to parasite killing. This detailed understanding of the mechanism paves the way to rationally re-designed 8-aminoquinolines with improved pharmacological profiles.
DepartmentMassachusetts Institute of Technology. Institute for Medical Engineering & Science
Springer Science and Business Media LLC
Camarda, Grazia et al. “Antimalarial activity of primaquine operates via a two-step biochemical relay.” Nature Communications 10 (2019): 3226 © 2019 The Author(s)
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