Superoxide dismutase in Plasmodium: a current survey

Superoxide anion plays a role in the production of hydroxyl radical, interacts with protein containing ironsulfur clusters and is involved in formation of peroxynitrite.1–3 Currently, only dihydroorotate dehydrogenase can be considered as an endogenous enzymatic superoxide source in Plasmodium.4 The digestion of haemoglobin is another source of superoxide anion.5 Haemoglobin autoxidation in the host red blood cell (RBC) is an exogenous source of superoxide which can be destroyed by an abundant RBC superoxide dismutase.6 Some cells implicated in the immune response produce superoxide anion via NADPH oxidase.7 The involvement of immune cells in the production of an oxidative stress against Plasmodium has been demonstrated by many research groups.8–14 Exposure of parasites to superoxide using superoxide producing molecules12,15,16 or activated cells8,14 results in a decrease of parasite growth. Superoxide is also able to impair the transmission capacity of the parasite.17,18