Proteomic Insights into the Mechanism of Action of Maduramicin, a Novel Ionophore with Potent Antimalarial Activity

Malaria is a common infectious disease in tropical countries and poses serious health burden due to limited treatment choices. In recent years, many of the state of the art anti-malarials such as Artemisinin, Chloroquine and Primaquine have been rendered ineffective due to emergence of resistant parasites. This underscores the urgent need to develop new anti-malarials and elucidate their mechanism of action. Recently, we have demonstrated the potent anti-malarial properties of a known anti-coccidial ionophore, Maduramicin. In this study, we investigated the mechanisms of action of Maduramicin in P. falciparum by assessing its stage-specific activity and time-dependent effect on parasite development. The drug exhibited maximum anti-malarial activity against the schizont stage and was characterised as a slow-acting drug. To gain mechanistic insights, we employed iTRAQ based quantitative proteomics approach to analyse global proteome alterations in P. falciparum following Maduramicin treatment. Analysis of the differentially regulated proteins were carried out by using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway database. The data reflected significant perturbations in protein synthesis, energy metabolism, and other key metabolic pathways in response to Maduramicin treatment. Collectively, our results of the proteomics study were validated by quantitative RT-PCR analysis of 9 representative genes. Our findings provide the basis for understanding the lethal activity of Maduramicin on P.falciparum.