RESUMO
The World Health Organization classifies Leishmania as one of the 17 "neglected diseases" that burden tropical and sub-tropical climate regions with over half a million diagnosed cases each year. Despite this, currently available anti-leishmania drugs have high toxicity and the potential to be made obsolete by parasite drug resistance. We chose to analyze organoselenides for leishmanicidal potential given the reduced toxicity inherent to selenium and the displayed biological activity of organoselenides against Leishmania. Thus, the biological activities of 77 selenoesters and their N-aryl-propanamide derivatives were predicted using robust in silico models of Leishmania infantum, Leishmania amazonensis, Leishmania major, and Leishmania (Viannia) braziliensis. The models identified 28 compounds with >60% probability of demonstrating leishmanicidal activity against L. infantum, and likewise, 26 for L. amazonesis, 25 for L. braziliensis, and 23 for L. major. The in silico prediction of ADMET properties suggests high rates of oral absorption and good bioavailability for these compounds. In the in silico toxicity evaluation, only seven compounds showed signs of toxicity in up to one or two parameters. The methodology was corroborated with the ensuing experimental validation, which evaluated the inhibition of the Promastigote form of the Leishmania species under study. The activity of the molecules was determined by the IC50 value (µM); IC50 values < 20 µM indicated better inhibition profiles. Sixteen compounds were synthesized and tested for their activity. Eight molecules presented IC50 values < 20 µM for at least one of the Leishmania species under study, with compound NC34 presenting the strongest parasite inhibition profile. Furthermore, the methodology used was effective, as many of the compounds with the highest probability of activity were confirmed by the in vitro tests performed.
RESUMO
BACKGROUND: Natural products are useful agents for the discovery of new lead- compounds and effective drugs to combat coronaviruses (CoV). OBJECTIVE: The present work provides an overview of natural substances, plant extracts, and essential oils as potential anti-SARS-CoV agents. In addition, this work evaluates their drug-like properties which are essential in the selection of compounds in order to accelerate the drug development process. METHODS: The search was carried out using PubMed, ScienceDirect and SciFinder. Articles addressing plant-based natural products as potential SARS-CoV or SARS-CoV-2 agents within the last seventeen years were analyzed and selected. The descriptors for Chemometrics analysis were obtained in alvaDesc and the principal component analysis (PCA) was carried out in SIMCA version 13.0. RESULTS: Based on in vitro assays and computational analyses, this review covers twentynine medicinal plant species and more than 300 isolated substances as potential anti-coronavirus agents. Among them, flavonoids and terpenes are the most promising compound classes. In silico analyses of drug-like properties corroborate these findings and indicate promising candidates for in vitro and in vivo studies to validate their activity. CONCLUSION: This paper highlights the role of ethnopharmacology in drug discovery and suggests the use of integrative (in silico/ in vitro) and chemocentric approaches to strengthen current studies and guide future research in the field of antiviral agents.
