Activity of benzothiazoles and chemical derivatives onPlasmodium falciparum

Abstract

Malaria is a major health concern particularly in Africa which has about 90% of the worldwide annual clinical cases. The increasing number of drug-resistantPlasmodium falciparumjustifies the search for new drugs in this field. Antimalarial activity of 2-substituted 6-nitro- and 6-amino-benzothiazoles and their anthranilic acids has been tested. Anin vitrostudy has been performed on W2 and 3D7 strains ofP. falciparumand on clinical isolates from malaria-infected patients. Toxicity has been assessed on THP1 human monocytic cells. For the most active drug candidates, thein vitrostudy was followed byin vivoassaysonP. berghei-infected mice and byin vitroassays in order to determine the stage-dependency and the mechanism of action. Of 39 derivatives testedin vitro, 2 had specific antimalarial properties. Each compound was active on all stages of the parasite, but one was markedly active on mature schizonts, while the other was more active on young schizont forms. Both drugs were also active on mitochondrial membrane potential.In vivodata confirmed efficiency with a sustained decrease of parasitaemia. Products A12 and C7 may be considered as potential antimalarial worthy of further chemical and biological research.