Caracterização da atividade antiparasitária do dietilditiocarbamato frente a diferentes cepas de Trypanosoma cruzi

• Ano de defesa: 2019
• Autor(a) principal: Oliveira, Johny Wysllas de Freitas
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Brasil; UFRN; PROGRAMA DE PÓS-GRADUAÇÃO EM BIOQUÍMICA
• Palavras-chave em Português: Doença de Chagas; Trypanosoma cruzi; DETC; Atividade antiparasitária; DTU’s; CNPQ::CIENCIAS BIOLOGICAS::BIOQUIMICA
• Link de acesso: https://repositorio.ufrn.br/jspui/handle/123456789/27810

The Chagas Disease caused by protozoan Trypanosoma cruzi, affects thousands of people annually. The traditional pharmaceuticals used in treatment have high toxicity and are not efficient in the chronic phase of disease. Furthermore, the genetic diversity of parasite may cause different clinical manifestations and resistance for treatment. The sodium diethyldithiocarbamate attachment the dithiocarbamate class, chemical compounds of high pharmacological versatility that can interact with metals and induced the production of radical oxygen and nitrogen species. The main of this project is characterize the inhibitory action of DETC against different strains of T. cruzi. Firstly, the different strains Dm28c (TcI), Y (TcII), QMM9 (TcIII) e Cl Brener (TCVI) grown in LIT medium. The antiparasitic assay evaluated distinct concentration of DETC at time 24 hours and 48 hours, by count and resazurin methods, against epimastigote and trypomastigote forms of T. cruzi. The cellular cytotoxicity was analyzed utilizing animal lineage 3T3 (fibroblasts) and RAW (Macrophage) 24 hours after compound application and evaluated by the MTT assay. Additionally, was analyzed the parasite dead mechanisms triggered by the compound averse to T. cruzi epimastigote in 24 hours. Was observed too the mitochondrial activity of different strains of T. cruzi in epimastigote form after 24 hours of treatment by scanning electronic microscopy. In addiction, was evaluate the inhibitory action of DETC on proteolytic proteins of T. cruzi extracts by zymography followed by densitometry. Considering that the dithiocarbamate has an important inhibitory action against α-carbonic anhydrase of T. cruzi sought to demonstrate the docking of DETC in this protein through of in silico assay of molecular docking. Upon antiparasitic assay was determinate DETC concentration necessary for reducing the populational growth in 50% (IC50) each strains in 24 hours, resulting of 28,8 µM until 66,4 µM for epimastigote form and 23,5 µM until 79,0 µM for trypomastigote form depending on strain. Through of cellular cytotoxicity was evaluate inhibitory profile of compound that demonstrated moderate cytotoxicity against animal lineages 3T3 and RAW, thus determining IC50 81,46 µM for 3T3 e 96,34 µM for RAW. The inexistence or very low activity of markers annexin and PI (Inorganic phosphate),cause the unavailability determinate of cellular death mechanism by DETC against the parasite. Upon the mitochondrial potential evaluation was show the mitochondrial damages caused by DETC on different parasite strains, inhibiting the internal mitochondrial potential activity in 80%. Through the scanning electronic microscopy was observed that the compound present different actions in parasite cellular structure, resulting in membrane discontinuity, pores and ruptures. Furthermore the zymography founded the reduction in proteolytic activity of parasite extracts achieving 36%. Furthermore, DETC showed high capacity for biding with αcarbonic anhydrase of T. cruzi, analyzing the docking location in protein structure. Therefore, DETC presents like a possible candidate for alternative treatment of Chagas Disease due elevate antiparasitic activity, moderate cytotoxicity and present acting against specific targets of parasite.