The Sound of Evolution
Chloroquine
Mechanism of action:
Chloroquine is a 4-aminoquinoline derivative. Chloroquine mainly acts on the trophozoite stage of the malaria parasite during its erythrocytic stage. The parasite degrades host hemoglobin to obtain amino acids, and this process generates free heme (heme, Fe²⁺-protoporphyrin IX), which is toxic because it can generate free radicals. The parasite normally polymerizes this toxic heme into non-toxic hemozoin. Chloroquine binds to heme and forms a complex that blocks the conversion of heme into hemozoin. The chloroquine-heme complex and the accumulated toxic heme disrupt parasite cell membranes and various intracellular molecules, ultimately killing the parasite.
Reference(s):
1. Li C et al. (2017). Chloroquine, a FDA-approved drug, prevents Zika virus infection and its associated congenital microcephaly in mice. EBioMedicine.
2. Shiryaev SA et al. (2017). Repurposing of the anti-malaria drug chloroquine for Zika virus treatment and prophylaxis. Sci Rep.
3. Gao J et al. (2020). Breakthrough: Chloroquine phosphate has shown apparent efficacy in treatment of COVID-19 associated pneumonia in clinical studies. Biosci Trends.