Investigation of the antileishmanial activity and mechanisms of action of acetyl-thiohydantoins

• Published in: Chemico-biological interactions Vol. 351; p. 109690
• Main Authors: Bortoleti, Bruna Taciane da Silva, Gonçalves, Manoela Daiele, Tomiotto-Pellissier, Fernanda, Camargo, Priscila Goes, Assolini, João Paulo, Concato, Virginia Marcia, Detoni, Mariana Barbosa, Bidóia, Danielle Larazin, Bispo, Marcelle de Lima Ferreira, Lima, Camilo Henrique da Silva, de Macedo, Fernando Cesar, Conchon-Costa, Ivete, Miranda-Sapla, Milena Menegazzo, Wowk, Pryscilla Fanini, Pavanelli, Wander Rogério
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier B.V 05-01-2022
• Subjects: ADAM17 Protein - metabolism; Animals; Apoptosis-like; Arginase - metabolism; G2 Phase Cell Cycle Checkpoints - drug effects; Heterocyclic; Humans; L. amazonensis; Leishmania - drug effects; Leishmania - enzymology; Mice; Mitochondria - drug effects; Molecular docking; Molecular Docking Simulation; Protozoan Proteins - metabolism; Sheep; Thiohydantoins; Thiohydantoins - chemical synthesis; Thiohydantoins - metabolism; Thiohydantoins - pharmacology; Thiohydantoins - toxicity; Trypanocidal Agents - chemical synthesis; Trypanocidal Agents - metabolism; Trypanocidal Agents - pharmacology; Trypanocidal Agents - toxicity; Tumor Necrosis Factor-alpha - metabolism; Apoptosis-like; Heterocyclic; Molecular docking; Thiohydantoins; L. amazonensis
• ISSN: 0009-2797; 1872-7786
• DOI: 10.1016/j.cbi.2021.109690

The currently available treatment options for leishmaniasis are associated with high costs, severe side effects, and high toxicity. In previous studies, thiohydantoins demonstrated some pharmacological activities and were shown to be potential hit compounds with antileishmanial properties.
The present study further explored the antileishmanial effect of acetyl-thiohydantoins against Leishmania amazonensis and determined the main processes involved in parasite death. We observed that compared to thiohydantoin nuclei, acetyl-thiohydantoin treatment inhibited the proliferation of promastigotes. This treatment caused alterations in cell cycle progression and parasite size and caused morphological and ultrastructural changes. We then investigated the mechanisms involved in the death of the protozoan; there was an increase in ROS production, phosphatidylserine exposure, and plasma membrane permeabilization and a loss of mitochondrial membrane potential, resulting in an accumulation of lipid bodies and the formation of autophagic vacuoles on these parasites and confirming an apoptosis-like process. In intracellular amastigotes, selected acetyl-thiohydantoins reduced the percentage of infected macrophages and the number of amastigotes/macrophages by increasing ROS production and reducing TNF-α levels. Moreover, thiohydantoins did not induce cytotoxicity in murine macrophages (J774A.1), human monocytes (THP-1), or sheep erythrocytes. In silico and in vitro analyses showed that acetyl-thiohydantoins exerted in vitro antileishmanial effects on L. amazonensis promastigotes in apoptosis-like and amastigote forms by inducing ROS production and reducing TNF-α levels, indicating that they are good candidates for drug discovery studies in leishmaniasis treatment. Additionally, we carried out molecular docking analyses of acetyl-thiohydantoins on two important targets of Leishmania amazonensis: arginase and TNF-alpha converting enzyme. The results suggested that the acetyl groups in the N1-position of the thiohydantoin ring and the ring itself could be pharmacophoric groups due to their affinity for binding amino acid residues at the active site of both enzymes via hydrogen bond interactions. These results demonstrate that thiohydantoins are promising hit compounds that could be used as antileishmanial agents.
The structural design, the experimental approach for evaluating antileishmanial effects, and the molecular docking studies of acetyl-thiohydantoins (1a-e). [Display omitted]
•Thiohydantoins cause low cytotoxicity in monocytes, macrophages, and erythrocytes.•Acetyl-thiohydantoins cause morphological and ultrastructural changes in promastigotes.•Acetyl-thiohydantoins acts through a mechanism similar to apoptosis in promastigotes.•Acetyl-thiohydantoin eliminates amastigotes through ROS production and reduced TNF-α levels in infected macrophages.•Acetyl-thiohydantoins presents drug-likeness and interacts with Leishmania arginase and TNF-α converting enzyme.