ABSTRACT
D uring its intraerythrocytic life cycle, Plasmodium digests up to 80% o f host hemoglobin as its nutrient source. However, this process releases the monomer heme that is very toxic for the parasite. Therefore, heme is sequestered as an insoluble, crystalline, dark-brown pigment called hemozoin (HZ), which is formed by heme dimers that interact through hydrogen bonds. The presence o f HZ inside erythrocytes and leukocytes has been used in malaria diagnosis and prognosis. Its synthesis is analogous to a process of “biocrystallization*’ and appears to be the target o f potent antimalarial drugs; however, it is not completely understood whether it is autocatalytic or if it requires the participation of proteins and/or lipids. Even though H Z was considered as a nontoxic metabolic byproduct, different lines o f evidence, including its rapid phagocytosis, its accumulation inside organs and its abil ity to modulate macrophage signaling and functions, suggest that HZ might contribute to malaria immunopathology.
