Atividade leishmanicida do veneno de tityus serrulatus e tratamento in vitro de macrófagos infectados

• Ano de defesa: 2009
• Autor(a) principal: Diogo Garcia Valadares
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso embargado
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; Brasil; ICB - DEPARTAMENTO DE BIOQUÍMICA E IMUNOLOGIA; Programa de Pós-Graduação em Bioquímica e Imunologia; UFMG
• Palavras-chave em Português: Tityus serrulatus; veneno; atividade leishmanicida; Bioquímica e imunologia; Venenos de Escorpião; Leishmania; Macrófagos; Doenças Parasitárias
• Link de acesso: http://hdl.handle.net/1843/59606

Leishmaniases are a group of infectious diseases caused by protozoa of the genus Leishmania. The treatment of leishmaniasis is limited by factors such as toxicity, side effects and cost. Tityus serrulatus scorpion venom is a complex compound that contains a variety of proteins, peptides and other bioactive compounds. Previous studies have shown that T. serrulatus venom has antimicrobial activity against a variety of bacteria, fungi and protozoa. In this study, we evaluated the leishmanicidal activity of the total venom of T. serrulatus against three species of Leishmania: L. amazonensis, L. chagasi and L. major. The results showed that the total venom of T. serrulatus was effective in killing all three species of Leishmania, both in the promastigote forms in the stationary growth phase and in the amastigote-like forms. Furthermore, the total venom of T. serrulatus was able to reduce Leishmania adhesion in peritoneal macrophages, which may also contribute to its leishmanicidal effect. To investigate the mechanisms of action of T. serrulatus venom, we purified the venom and analyzed its fractions. The results showed that the FG50 fraction was the most active against Leishmania, and that it induced the activation of macrophages via expression of the iNOS enzyme. Macrophage activation is an important process in the defense against parasitic infections, and its induction by the FG50 fraction may contribute to its leishmanicidal effect. The results of this study suggest that T. serrulatus venom is a promising new therapy for leishmaniasis.