Quinine has been employed in the treatment of malaria for centuries and is still used against severe Plasmodium falciparum malaria. However, its interactions with the parasite remain poorly understood and subject to debate. In this study, we used the Saccharomyces cerevisiae eukaryotic model to better understand quinine's mode of action and the mechanisms underlying the cell response to the drug.
Plasmodium falciparum resistance to chloroquine and sulphadoxine–pyrimethamine has led to the recent adoption of artemisinin-based combination therapies (ACTs) as the first line of treatment against malaria. ACTs comprise semisynthetic artemisinin derivatives paired with distinct chemical classes of longer acting drugs. These artemisinins are exceptionally potent against the pathogenic asexual blood stages of Plasmodium parasites and also act on the transmissible sexual stages.
The evolution of resistance in Plasmodium falciparum against safe and affordable drugs such as chloroquine (CQ) and sulfadoxine-pyrimethamine (SP) is a major global health threat. Investigating the dynamics of resistance against these antimalarial drugs will lead to approaches for addressing the problem of resistance in malarial parasites that are solidly based in evolutionary genetics and population biology. In this article, we discuss current developments in population biology modeling and evolutionary genetics.
Fatty acids are essential components of membranes, and are also involved in cell signalling. Plasmodium, the parasite that causes malaria, scavenges fatty acids from its hosts. However, Plasmodium also possesses enzymes for a prokaryotic-like de novo fatty acid synthesis pathway, which resides in the apicoplast. Recent research has demonstrated that Plasmodium parasites depend on de novo fatty acid synthesis only for liver-stage development.
Sulfadoxine-pyrimethamine (SP) resistance in Plasmodium falciparum has been widespread across continents, causing the major hurdle of controlling malaria. Resistance is encoded mainly by point mutations in P. falciparum dihydrofolate reductase (pfdhfr) and dihydropteroate synthase (pfdhps) target genes. To study the origin and evolution of pyrimethamine resistance on the Indian subcontinent, microsatellite markers flanking the pfdhfr gene were mapped. Here we describe the characteristics of genetic hitchhiking around the pfdhfr gene among 190 P. falciparum isolates.
In the field of malaria vaccines, there are many barriers to moving lead candidates from the bench into developmental programmes before clinical testing. Many of the same challenges are to be found in the field of vaccines for other infectious diseases. Here, we briefly outline the process of pre-clinical development to help identify ways to support the translation of laboratory-based information into viable vaccine candidates.
Almost one million people die of severe malaria every year. In recent years, artemisinin-based combination therapies have become the backbone of the treatment of uncomplicated falciparum malaria and have helped to reduce the burden of malaria in large parts of the malaria-endemic world. However, the treatment of severe malaria,the clinical syndrome responsible for most malaria-associated deaths, remains largely unaffected by this development.
The prevention and management of malaria is primarily based on the use of drugs. Clinical trials have however revealed that between individuals there is large variability in the pharmacokinetic profiles of many antimalarial drugs. The resulting variations in concentrations of the drug within plasma might lead to either suboptimum effectiveness or drug toxicity in some patients.
Hemoglobin (Hb) degradation is essential for the growth of the intraerythrocytic stages of malarial parasites. This process, which occurs inside an acidic digestive vacuole (DV), is thought to involve the action of four aspartic proteases, termed plasmepsins (PMs). These enzymes have received considerable attention as potential antimalarial drug targets.
Artemisinin-based combination therapies are now widely recommended as first-line treatment for uncomplicated malaria. However, which therapies are optimal is a matter of debate. We aimed to compare the short- and longer-term efficacy of 2 leading therapies in a cohort of young Ugandan children.