In silico Screening and Evaluation of Plasmodium falciparum Protein Kinase 5 (PK5) Inhibitors

Study of the naturally occurring lignan brachangobinan A as antiplasmodial agent: Synthesis, biological evaluation, and in silico prediction

This study focused on the synthesis, structural validation, and evaluation of the antiplasmodial efficacy of brachangobinan A (BA) and its enantiomers, (+)-BA and (-)-BA, as potential antimalarial agents. BA, (+)-BA, and (-)-BA were synthesized through chemical processes and validated via advanced spectroscopic techniques. In vitro studies were conducted to assess their efficacy against Plasmodium falciparum strains 3D7 and K1 by determining their half maximal inhibitory concentration (IC50) values, cytotoxicity profiles, and selectivity indices. Additional evaluations examined the impacts of exposure to these compounds on stage-specific effects, parasite morphology, and parasitemia levels, as well as potential mechanisms of action through in silico drug target prediction and molecular docking simulations. In vivo efficacy was tested in a mouse model of malaria caused by P. yoelii 17XNL. The results revealed that BA, (+)-BA, and (-)-BA exhibited promising in vitro antiplasmodial activity and selectivity, inducing morphological changes and demonstrating cidal effects. Drug-likeness predictions indicated favorable safety profiles but challenges in terms of bioavailability. In silico analyses identified Pf HSP90, Pf CDK2H, and Pf MAPK as key targets of (+)-BA and (-)-BA. In vivo studies confirmed the efficacy of BA in reducing parasitemia levels (trial 1: 19.72 %; trial 2: 15.00 %) compared with the untreated group (trial 1: 29.95 %; trial 2: 28.27 %) without adverse effects. These findings suggest that BA and its enantiomers have potential as seed compounds for development of antimalarial agents.

Artificial Intelligence Applied to the Rapid Identification of New Antimalarial Candidates with Dual-Stage Activity

Increasing reports of multidrug-resistant malaria parasites urge the discovery of new effective drugs with different chemical scaffolds. Protein kinases play a key role in many cellular processes such as signal transduction and cell division, making them interesting targets in many diseases. Protein kinase 7 (PK7) is an orphan kinase from the Plasmodium genus, essential for the sporogonic cycle of these parasites. Here, we applied a robust and integrative artificial intelligence-assisted virtual-screening (VS) approach using shape-based and machine learning models to identify new potential PK7 inhibitors with in vitro antiplasmodial activity. Eight virtual hits were experimentally evaluated, and compound LabMol-167 inhibited ookinete conversion of Plasmodium berghei and blood stages of Plasmodium falciparum at nanomolar concentrations with low cytotoxicity in mammalian cells. As PK7 does not have an essential role in the Plasmodium blood stage and our virtual screening strategy aimed for both PK7 and blood-stage inhibition, we conducted an in silico target fishing approach and propose that this compound might also inhibit P. falciparum PK5, acting as a possible dual-target inhibitor. Finally, docking studies of LabMol-167 with P. falciparum PK7 and PK5 proteins highlighted key interactions for further hit-to lead optimization.

Parasite and Host Erythrocyte Kinomics of Plasmodium Infection

Malaria remains a heavy public health and socioeconomic burden in tropical and subtropical regions. Increasing resistance against front-line treatments implies that novel targets for antimalarial intervention are urgently required. Protein kinases of both the parasites and their host cells possess strong potential in this respect. We present an overview of the updated kinome of Plasmodium falciparum, the species that is the largest contributor to malaria mortality, and of current knowledge pertaining to the function of parasite-encoded protein kinases during the parasite's life cycle. Furthermore, we detail recent advances in drug initiatives targeting Plasmodium kinases and outline the potential of protein kinases in the context of the growing field of host-directed therapies, which is currently being explored as a novel way to combat parasite drug resistance.

Plasmodial Kinase Inhibitors Targeting Malaria: Recent Developments

Recent progress in reducing malaria cases and ensuing deaths is threatened by factors like mutations that induce resistance to artemisinin derivatives. Multiple drugs are currently in clinical trials for malaria treatment, including some with novel mechanisms of action. One of these, MMV390048, is a plasmodial kinase inhibitor. This review lists the recently developed molecules which target plasmodial kinases. A systematic review of the literature was performed using CAPLUS and MEDLINE databases from 2005 to 2020. It covers a total of 60 articles and describes about one hundred compounds targeting 22 plasmodial kinases. This work highlights the strong potential of compounds targeting plasmodial kinases for future drug therapies. However, the majority of the Plasmodium kinome remains to be explored.

An Update on Development of Small-Molecule Plasmodial Kinase Inhibitors

Malaria control relies heavily on the small number of existing antimalarial drugs. However, recurring antimalarial drug resistance necessitates the continual generation of new antimalarial drugs with novel modes of action. In order to shift the focus from only controlling this disease towards elimination and eradication, next-generation antimalarial agents need to address the gaps in the malaria drug arsenal. This includes developing drugs for chemoprotection, treating severe malaria and blocking transmission. Plasmodial kinases are promising targets for next-generation antimalarial drug development as they mediate critical cellular processes and some are active across multiple stages of the parasite's life cycle. This review gives an update on the progress made thus far with regards to plasmodial kinase small-molecule inhibitor development.

Targeting malaria protein kinases

Malaria is one of the most impacting public health problems in tropical and subtropical areas of the globe, with approximately 200 million cases worldwide annually. In the absence of an effective vaccine, rapid treatment is vital for effective malaria control. However, parasite resistance to currently available drugs underscores the urgent need for identifying new antimalarial therapies with new mechanisms of action. Among potential drug targets for developing new antimalarial candidates, protein kinases are attractive. These enzymes catalyze the phosphorylation of several proteins, thereby regulating a variety of cellular processes and playing crucial roles in the development of all stages of the malaria parasite life cycle. Moreover, the large phylogenetic distance between Plasmodium species and its human host is reflected in marked differences in structure and function of malaria protein kinases between the homologs of both species, indicating that selectivity can be attained. In this review, we describe the functions of the different types of Plasmodium kinases and highlight the main recent advances in the discovery of kinase inhibitors as potential new antimalarial drug candidates.