Sara Teixeira de Macedo Silva1,2, Gonzalo Visbal3, Joseane Lima Prado Godinho1,2, Julio A Urbina4, Wanderley de Souza1,2, Juliany Cola Fernandes Rodrigues1,2,5. 1. Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil. 2. Instituto Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem, Rio de Janeiro, Brazil. 3. Instituto Nacional de Metrologia, Qualidade e Tecnologia, Rio de Janeiro, Brazil. 4. Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela. 5. Núcleo Multidisciplinar de Pesquisa UFRJ-Xerém, Divisão Biologia, Universidade Federal do Rio de Janeiro, Campus Duque de Caxias, Rio de Janeiro, Brazil.
Abstract
Objectives: Leishmaniasis, one of the most significant neglected diseases around the world, is caused by protozoan parasites of the Leishmania genus. Nowadays, the available aetiological treatments for leishmaniasis have variable effectiveness and several problems such as serious side effects, toxicity, high cost and an increasing number of resistance cases. Thus, there is an urgent need for safe, oral and cost-effective drugs for leishmaniases. Previously, our group has shown the effect of the ergosterol biosynthesis inhibitors on Leishmania amazonensis. Herein, we showed the effect of ravuconazole against L. amazonensis; ravuconazole is a second-generation triazole antifungal drug that has good bioavailability after oral administration and a long terminal half-life in humans, a broad activity spectrum, high effectiveness in treatment of mycosis and negligible side effects. Methods: Several methodologies were used: cell culture, fluorescence and electron microscopy, high-resolution capillary GC coupled with MS, fluorimetry and flow cytometry. Results: Our results showed that ravuconazole was able to inhibit the proliferation of L. amazonensis promastigotes and intracellular amastigotes in vitro, with single-digit to sub-micromolar IC50 values, causing several alterations in the morphology, ultrastructure, cell viability and physiology of the parasites. The mitochondrion was significantly affected by the treatment, resulting in a collapse of the mitochondrial transmembrane potential that consequently led to inhibition of ATP production, combined with an increase in reactive oxygen species and mitochondrial superoxide production; by transmission electron microscopy, the organelle displayed a completely altered ultrastructure. The treatment changed the lipid profile, showing a profound depletion of the 14-desmethyl endogenous sterol pool. Conclusions: These results suggest that ravuconazole could be an alternative option for the treatment of leishmaniasis.
Objectives:Leishmaniasis, one of the most significant neglected diseases around the world, is caused by protozoan parasites of the Leishmania genus. Nowadays, the available aetiological treatments for leishmaniasis have variable effectiveness and several problems such as serious side effects, toxicity, high cost and an increasing number of resistance cases. Thus, there is an urgent need for safe, oral and cost-effective drugs for leishmaniases. Previously, our group has shown the effect of the ergosterol biosynthesis inhibitors on Leishmania amazonensis. Herein, we showed the effect of ravuconazole against L. amazonensis; ravuconazole is a second-generation triazole antifungal drug that has good bioavailability after oral administration and a long terminal half-life in humans, a broad activity spectrum, high effectiveness in treatment of mycosis and negligible side effects. Methods: Several methodologies were used: cell culture, fluorescence and electron microscopy, high-resolution capillary GC coupled with MS, fluorimetry and flow cytometry. Results: Our results showed that ravuconazole was able to inhibit the proliferation of L. amazonensis promastigotes and intracellular amastigotes in vitro, with single-digit to sub-micromolar IC50 values, causing several alterations in the morphology, ultrastructure, cell viability and physiology of the parasites. The mitochondrion was significantly affected by the treatment, resulting in a collapse of the mitochondrial transmembrane potential that consequently led to inhibition of ATP production, combined with an increase in reactive oxygen species and mitochondrial superoxide production; by transmission electron microscopy, the organelle displayed a completely altered ultrastructure. The treatment changed the lipid profile, showing a profound depletion of the 14-desmethyl endogenous sterol pool. Conclusions: These results suggest that ravuconazole could be an alternative option for the treatment of leishmaniasis.
Authors: Job D F Inacio; Myslene S Fonseca; Gabriel Limaverde-Sousa; Ana M Tomas; Helena Castro; Elmo E Almeida-Amaral Journal: Front Cell Infect Microbiol Date: 2021-03-25 Impact factor: 5.293
Authors: Sara Teixeira de Macedo-Silva; Gonzalo Visbal; Gabrielle Frizzo Souza; Mayara Roncaglia Dos Santos; Simon B Cämmerer; Wanderley de Souza; Juliany Cola Fernandes Rodrigues Journal: Sci Rep Date: 2022-07-04 Impact factor: 4.996
Authors: Fernando Almeida-Souza; Verônica Diniz da Silva; Gabriel Xavier Silva; Noemi Nosomi Taniwaki; Daiana de Jesus Hardoim; Camilla Djenne Buarque; Ana Lucia Abreu-Silva; Kátia da Silva Calabrese Journal: Int J Mol Sci Date: 2020-09-18 Impact factor: 5.923