Molecular modeling and simulation study of homoserine kinase as an effective leishmanial drug target

Overview of Research on Leishmaniasis in Africa: Current Status, Diagnosis, Therapeutics, and Recent Advances Using By-Products of the Sargassaceae Family

Leishmaniasis in Africa, which has been designated as a priority neglected tropical disease by various global organizations, exerts its impact on millions of individuals, primarily concentrated within this particular region of the world. As a result of the progressively grave epidemiological data, numerous governmental sectors and civil organizations have concentrated their endeavors on this widespread outbreak with the objective of devising appropriate remedies. This comprehensive examination delves into multiple facets of this parasitic ailment, scrutinizing the associated perils, diagnostic intricacies, and deficiencies within the existing therapeutic protocols. Despite the established efficacy of current treatments, they are not immune to deleterious incidents, particularly concerning toxicity and the emergence of parasitic resistance, thus accentuating the necessity of exploring alternative avenues. Consequently, this research not only encompasses conventional therapeutic approaches, but also extends its scope to encompass complementary and alternative medicinal techniques, thereby striving to identify innovative solutions. A particularly auspicious dimension of this study lies in the exploration of natural substances and by-products derived from some brown algae of the Sargassaceae family. These resources possess the potential to assume a pivotal role in the management of leishmaniasis.

Identification of potent inhibitors for Leishmania donovani homoserine kinase: an integrated in silico and kinetic study

Leishmaniasis is caused by ∼20 species of Leishmania that affects millions in endemic areas. Available therapies are not sufficient to effectively control the disease, cause severe side effects and eventually lead to drug resistance, making the discovery of novel therapeutic molecules an immediate need. Molecular target-based drug discovery, where the target is a defined molecular gene, protein or a mechanism, is a rationale driven approach for novel therapeutics. Humans obtain the essential amino acid such as threonine from dietary sources, while Leishmania synthesize it de-novo. Enzymes of the threonine biosynthesis pathway, including the rate limiting Homoserine kinase (HSK) which converts L-homoserine into ortho-phospho homoserine are thus attractive targets for rationale driven therapy. The absence of HSK in humans and its presence in Leishmania donovani enhances the opportunity to exploit HSK as a molecular target for anti-leishmanials therapeutic development. In this study, we utilize structure-based high throughput drug discovery (SBDD), followed by biochemical validation and identified two potential inhibitors (RH00038 and S02587) from Maybridge chemical library that targets L. donovani HSK. These two inhibitors effectively induced the mortality of Leishmania donovani in both amastigote and promastigote stages, with one of them being specific to parasite and twice as effective as the standard therapeutic molecule.

Discovery and Validation of Lmj_04_BRCT Domain, a Novel Therapeutic Target: Identification of Candidate Drugs for Leishmaniasis

Since many of the currently available antileishmanial treatments exhibit toxicity, low effectiveness, and resistance, search and validation of new therapeutic targets allowing the development of innovative drugs have become a worldwide priority. This work presents a structure-based drug discovery strategy to validate the Lmj_04_BRCT domain as a novel therapeutic target in Leishmania spp. The structure of this domain was explored using homology modeling, virtual screening, and molecular dynamics studies. Candidate compounds were validated in vitro using promastigotes of Leishmania major, L. amazonensis, and L. infantum, as well as primary mouse macrophages infected with L. major. The novel inhibitor CPE2 emerged as the most active of a group of compounds against Leishmania, being able to significantly reduce the viability of promastigotes. CPE2 was also active against the intracellular forms of the parasites and significantly reduced parasite burden in murine macrophages without exhibiting toxicity in host cells. Furthermore, L. major promastigotes treated with CPE2 showed significant lower expression levels of several genes (α-tubulin, Cyclin CYCA, and Yip1) related to proliferation and treatment resistance. Our in silico and in vitro studies suggest that the Lmj_04_BRCT domain and its here disclosed inhibitors are new potential therapeutic options against leishmaniasis.