RESUMO
The global impact of malaria remains staggering despite extensive efforts to eradicate the disease. With increasing drug resistance and the absence of a clinically available vaccine, there is an urgent need for novel, affordable, and safe drugs for prevention and treatment of malaria. Previously, we described a novel antimalarial acridone chemotype that is potent against both blood-stage and liver-stage malaria parasites. Here, we describe an optimization process that has produced a second-generation acridone series with significant improvements in efficacy, metabolic stability, pharmacokinetics, and safety profiles. These findings highlight the therapeutic potential of dual-stage targeting acridones as novel drug candidates for further preclinical development.
Assuntos
Acridonas/química , Antimaláricos/química , Acridonas/farmacocinética , Acridonas/farmacologia , Acridonas/uso terapêutico , Administração Oral , Animais , Antimaláricos/farmacocinética , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Feminino , Meia-Vida , Células Hep G2 , Humanos , Estágios do Ciclo de Vida/efeitos dos fármacos , Malária/tratamento farmacológico , Malária/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/isolamento & purificação , Relação Estrutura-AtividadeRESUMO
Malaria remains one of the deadliest diseases in the world today. Novel chemoprophylactic and chemotherapeutic antimalarials are needed to support the renewed eradication agenda. We have discovered a novel antimalarial acridone chemotype with dual-stage activity against both liver-stage and blood-stage malaria. Several lead compounds generated from structural optimization of a large library of novel acridones exhibit efficacy in the following systems: (1) picomolar inhibition of in vitro Plasmodium falciparum blood-stage growth against multidrug-resistant parasites; (2) curative efficacy after oral administration in an erythrocytic Plasmodium yoelii murine malaria model; (3) prevention of in vitro Plasmodium berghei sporozoite-induced development in human hepatocytes; and (4) protection of in vivo P. berghei sporozoite-induced infection in mice. This study offers the first account of liver-stage antimalarial activity in an acridone chemotype. Details of the design, chemistry, structure-activity relationships, safety, metabolic/pharmacokinetic studies, and mechanistic investigation are presented herein.