5-Nitroindazole derivatives as potential therapeutic alternatives against Acanthamoeba castellanii Martín Escolano, Rubén Pérez Cordón, Gregorio Marín Sánchez, Clotilde Sánchez Moreno, Manuel Rosales Lombardo, María José Acanthamoeba castellanii Amoebicidal Chlorhexidine digluconate 5-nitroindazole derivatives This work was supported by the Spanish MINECO, FEDER funds of the E.U. [CTQ2013-14892 and 2010-CSD2010-00065] ; the Unidad de Excelencia MDM [2015-0038] ; and the Generalitat Valenciana (PROMETEO II 2015-002) . R.M.-E. is grateful for the fellowship from the Alfonso Martin Escudero Foundation. Amoebas of the genus Acanthamoeba are distributed worldwide, including species with a high pathogenic capacity for humans. In a similar way to what occurs with other parasitic protozoa, the available treatments show variable effectiveness in addition to high toxicity, which demands the development of new treatments. Positive results of 5-nitroindazole derivatives against several protozoa parasites suggest that these compounds may be a promising tool for the development of efficient antiparasitic drugs. In the present work we have evaluated the in vitro activity of ten 5-nitroindazole derivatives against Acanthamoeba castellanii trophozoites and cysts. To that end, AlamarBlue Assay Reagent® was used to determine the activity against trophozoites compared to the reference drug chlorhexidine digluconate. Cytotoxicity of the compounds was evaluated using Vero cells. The activity on cysts was evaluated by light microscopy and using a Neubauer chamber to quantifying cysts and presence of trophozoites, as an indication of cyst. Our results showed the effectiveness of the 5-nitroindazole derivatives tested against both trophozoites and cysts of A. castellani highlighting 5-nitroindazole derivative 8 which showed a 80% activity on cysts, which is higher than that of the reference drug. Moreover, 5-nitroindazole derivatives 8, 9 and 10 were more effective on trophozoites than the reference drug showing IC50 values lower than 5 μM. Taking together these results, these 5-nitroindazole derivatives specially compound 8, might be a promising alternative for the development of more efficient treatments against A. castellani infection. 2022-06-21T10:25:43Z 2022-06-21T10:25:43Z 2022-05-23 info:eu-repo/semantics/article Rubén Martín-Escolano... [et al.]. 5-Nitroindazole derivatives as potential therapeutic alternatives against Acanthamoeba castellanii, Acta Tropica, Volume 232, 2022, 106538, ISSN 0001-706X, [https://doi.org/10.1016/j.actatropica.2022.106538] http://hdl.handle.net/10481/75578 10.1016/j.actatropica.2022.106538 eng http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/openAccess Atribución 3.0 España Elsevier