Heme detoxification pathway (Plasmodium species)

The heme detoxification pathway in Plasmodium species encompasses the biochemical process by which the malaria parasite neutralizes toxic free heme, a byproduct of hemoglobin digestion inside infected erythrocytes. Plasmodium digests host-cell hemoglobin, releasing large quantities of heme, which is toxic due to its oxidative properties. The parasite detoxifies heme mainly by converting it into an insoluble, crystalline form called hemozoin (malaria pigment), primarily within its digestive vacuole. This process involves key parasite proteins, notably the heme detoxification protein (HDP), and possibly histidine-rich proteins such as PfHRP-2 in P. falciparum, which catalyze or scaffold hemozoin formation. Disruption of this pathway—particularly by antimalarial drugs like chloroquine and artemisinin—results in parasite death due to heme toxicity. This pathway represents a validated drug target, although it is a combination of molecules and processes rather than a single discrete molecular entity.

Other names

heme detoxificationhaem detoxificationhemozoin formation pathwayhemoglobin degradation–hemozoin pathway

Inhibition of heme to hemozoin crystallization, leading to toxic heme accumulation; Heme binding, preventing detoxification and inducing parasite toxicity.