Avaliação da atividade antiamebiana de compostos presentes no Covid-Box® contra trofozoítos de Acanthamoeba castellanii

Abstract

Free-living amoebas are ubiquitous protozoa that can be isolated from various environmental niches, such as soil, water and vegetation. The genus Acanthamoeba spp. has the characteristic of being amphizoic amoebas, being able to behave in the free and parasitic form. Acanthamoeba spp. it has two stages in its life cycle, the trophozoite, characterized as the metabolically active form and cyst, its active form. The drug repositioning is one of the strategies for the emergent infection’s treatment such as those occurred by the free-living ameba of the genus Acanthamoeba. In this context, this paper aimed to evaluate the anti-Acanthamoeba activity of the compounds present in the Covid-Box® in order to search for new therapeutical options for the amoebic keratitis and disseminated infections. The tests of the amebicidal activity were performed using the strain of the Acanthamoeba castellanii (ATCC 50492). In order to carry out the amebicity activity, the Acanthamoeba spp’s trophozoite were exposed in the concentration of the 10 µM of each compound present in the Covid-Box®. Moreover, the compounds that showed better amebicidal activity were evaluated in the concentrations of 20 µM, 15 µM, 10 µM, 5 µM and 2,5 µM to determine the IC50. Furthermore, to determine the trophozoites’ viability, it was used the viability indicator alamarBlue®. Also, the cytotoxicity assay against the SIRC of selected cells was performed. Ciclosenide and promethazine were able to considerably decrease the number of the A. castellanii’s trophozoites such as a viability decrease of the 35,01 ± 5,088% and 34,66 ± 5,165% respectively. Both ciclosenide and promethazine had lower ocular toxicity that the gold standard drug used in the amoebic keratitis treatment. The results allowed to identify two active compounds against the A.castellanii’s trophozoites with low cytotoxic potential which could be used as a study prototype of new active molecules, synergy studies, aiming to improve the treatments of the infections caused by Acanthamoeba spp.