Haemozoin

Haemozoin is a dark brown pigment found in the blood cells of many parasitic organisms, most notably the malaria parasite Plasmodium. It is formed as a byproduct of the parasite's digestion of hemoglobin, the oxygen-carrying protein in red blood cells. When the parasite consumes hemoglobin, it releases heme, a toxic molecule. The parasite then detoxifies heme by polymerizing it into insoluble haemozoin crystals. This process is crucial for the parasite's survival within the host's red blood cells.

The presence of haemozoin within infected red blood cells is a hallmark of malaria infection. Diagnostic methods for malaria often involve microscopic examination of blood smears to detect these pigmented crystals. The accumulation of haemozoin within the host's cells and its eventual release into the bloodstream are thought to contribute to some of the symptoms of malaria, such as fever and chills, through inflammatory responses.

The formation of haemozoin is a target for some antimalarial drugs. By inhibiting the parasite's ability to detoxify heme, these drugs can lead to the buildup of toxic heme, ultimately killing the parasite. Research into the precise mechanisms of haemozoin formation and its role in disease pathogenesis continues to be an active area of study in malaria research.