Integrated Experimental and Computational Investigation of Azobenzenoid Derivatives Against Trypanosomatid: RNA...

Neglected tropical diseases caused by pathogenic protozoa, including Chagas Disease (etiological agent Trypanosoma cruzi) and leishmaniasis (etiological agent Leishmania spp.), are public health problems in many developing countries.

Due to the lack of safe and effective therapies, the current study was designed to screen synthetic azobenzenoid derivatives using integrated in silico and in vitro assays.

Among the tested compounds, CaCS2 potentially inhibited promastigotes and amastigotes of Leishmania amazonensis and epimastigotes and trypomastigotes of Trypanosoma cruzi, while showing no cytotoxicity towards human J774A.1 and LLC-MK₂ cell lines. Reverse docking identified the parasite-specific RNA-editing ligase 1 (REL1), completely absent in humans, as a high-confidence target (p-value = 1.76 × 10^-12; MaxTC = 0.31). Similarly, docking simulations revealed high binding probabilities for CaCS2 in two main cavities of REL1, named the orthosteric and alternative sites, in both parasites. Molecular dynamic simulations confirmed stable CaCS2 binding at the orthosteric site, while interactions at the alternative site were transient.

Interestingly, CaCS2 was a specific ligand to REL1 and non cytotoxic to human cell lines, making it a promising scaffold for anti-trypanosomatid development.