Falcipain inhibition as a promising antimalarial target.

Falcipains are Plasmodium falciparum cysteine proteases involved in different processes of the erythrocytic cycle of the malaria parasite like hydrolysis of host hemoglobin, erythrocyte invasion, and erythrocyte rupture. These proteases constitute promising targets in the search for novel therapies that would ease the burden caused by the increasing resistance to current antimalarial drugs. Despite biochemical characterization of four falcipains so far, the search for new falcipain inhibitors has been limited to falcipain-2 and/ or falcipain-3, due to their interesting hemoglobinase capacity and the ample availability of tools to study them. We describe progress towards the discovery of promising falcipain inhibitors, in the light of their drug-like properties and the effect of the inhibition of several of these cysteine proteases. Some important aspects to focus on future development of falcipain inhibition are also discussed.