Honoring antiparasitics: The 2015 Nobel Prize in Physiology or Medicine

Abstract

Protozoa and helminths are the two main groups that cause parasitic diseases with a broad spectrum of clinical symptoms. Protozoa are unicellular organisms like the malaria parasite Plasmodium, which is responsible for the majority of deaths associated with parasitic infections. Helminths are alternative parasites that can produce debilitating diseases in hosts, some of which result in chronic infections. The discovery of effective therapeutic drugs is the key to improving health in regions of poverty and poor sanitation where these parasites usually occur. It is very encouraging that the 2015 Nobel Prize in Physiology or Medicine was awarded to Youyou Tu as well as William C. Campbell and Satoshi Õmura for their considerable contributions in discovering artemisinin and avermectin, respectively. Both drugs revolutionized therapies for filariasis and malaria, significantly reducing by large percentages their morbidity and mortality.

Keywords: 2015 Nobel Prize; Artemisinin; Avermectin filariasis; Malaria.

Fig. 1

(A) Artemisinin identified from Artemisia annua contains an endoperoxide bridge reacts with the iron atoms, leading to disruption on the hemoglobin catabolism and heme detoxification systems in the food vacuole of Plasmodium species by forming free radicals. Malaria parasites developing inside the erythrocyte are consequently damaged which treated with artemisinin. (B) Streptomyces avermectinius – originated avermectin possesses activity against nematodes including those cause river blindness and lymphatic filariasis by binding to glutamate-gated chloride channels in treated parasites, causing increased chloride ion influx and hyperpolarization of the parasite nerves. It, in turn, interferes with the transmission of nerve signals, leading to paralysis and death of the parasite in consequence.