A simple quinoline salt derivative is active in vitro against Plasmodiumfalciparum asexual blood stages and inhibits the development of cerebral malaria in murine model

Abstract

Chloroquine (CQ) was the most effective and widely used drug for the prophylaxis and treatment of severe and non-severe malaria. Although its prophylactic use has led to resistance to P. falciparum in all endemic countries, CQ still remains the drug of choice for the treatment of vivax malaria. Otherwise, the speed in which parasite resistance to available antimalarials rises and spreads in endemic regions points to the urgent need for the development of new antimalarials. Quinoline derivatives have been used as a tool in the search for new drugs and were investigated in the present study in an attempt to produce a HIT compound to avoid the cerebral malarial (CM). Seven compounds were synthesized, including three quinoline derivate salts. The cytotoxicity and antiplasmodial activity were assayed in vitro, highlighting compound 3 as a HIT, which also showed interaction with ferriprotoporphyrin IX similarly to CQ. Physicochemical and pharmacokinetic properties of absorption were found to be favorable when analyzed in silico. The in vivo assays, using the experimental cerebral malaria (ECM) model, showed important values of parasite growth inhibition on the 7th day-post infection (Q15 15 mg/kg: 76.9%, Q30 30 mg/kg: 90,1% and Q50 50 mg/kg: 92,9%). Compound 3 also showed significant protection against the development of CM, besides hepatic and renal parameters better than CQ. In conclusion, this quinoline derivative demonstrated promising activity for the treatment of malaria and was able to avoid the development of severe malaria in mice.