The role of hemozoin in disease: oxidative stress

Abstract

Infecting 200 million people chronically, Schistosoma mansoni, the helminth responsible for schistosomiasis, catabolizes host hemoglobin releasing amino acids and heme. To avoid the oxidative stress caused by toxic free heme, the heme aggregates into a biomineral known as hemozoin, which is comprised of heme molecules linked through an iron carboxylate bond. Subsequently, the schistosomes regurgitate this biomineral into the host vasculature where it is engulfed by professional phagocytes. Described in this work is the complete isolation and characterization of schistosomal hemozoin from host liver and spleen tissues and further exploration into hemozoin’s role in the pathogenesis of schistosomiasis. Hemozoin is shown to coincide with markers of oxidative stress in infected host tissue. A synthetic analogue of hemozoin, â-hematin, is demonstrated to facilitate the production of oxidative stress markers from components of cell membranes. The evidence gathered from these experiments supports the ability of hemozoin to promote oxidative stress.