Plasmodium falciparum heme detoxification pathway (HDP) (HDP)

The Plasmodium falciparum heme detoxification pathway is a vital metabolic process that allows the malaria parasite to survive during its infection of human red blood cells [1]. During this stage, the parasite digests host hemoglobin to obtain amino acids, a process that releases free heme (ferriprotoporphyrin IX), which is highly toxic to the parasite's membranes and enzymes [2]. To neutralize this threat, the parasite converts the toxic heme into an insoluble, non-toxic crystalline polymer called hemozoin, also known as malaria pigment [3]. This biocrystallization occurs within the parasite's acidic digestive vacuole and is facilitated by the Heme Detoxification Protein (HDP) and specific lipids [4]. This pathway is the primary target for several major classes of antimalarial drugs, including quinolines like chloroquine and quinine, which bind to heme or the growing crystal face to prevent further polymerization [5]. The resulting accumulation of free heme leads to oxidative stress and the eventual death of the parasite [1]. Despite its historical success as a drug target, the development of resistance mechanisms, such as mutations in the Plasmodium falciparum chloroquine resistance transporter (PfCRT), continues to pose a significant challenge to global malaria control efforts [6].

Other names

Hemozoin formation pathwayHeme biocrystallizationHeme polymerizationHemoglobin degradation pathway

Inhibition of heme biocrystallization into hemozoin, leading to the accumulation of toxic free heme.