Alterations on the growth and ultrastructure of Leishmania chagasi induced by squalene synthase inhibitors.
Vet Parasitol
; 146(1-2): 25-34, 2007 May 15.
Article
em En
| MEDLINE
| ID: mdl-17367936
Leishmaniasis is an important disease in widely dispersed regions of the world. In South America, visceral leishmaniasis (VL) is mainly caused by Leishmania chagasi. The morbidity associated with the infection is high, and death may occur in some untreated patients. Treatment has been based upon pentavalent antimonial drugs for more than half a century and problems, including development of resistance to antimonials and lack of efficacy against VL/HIV co-infections, have emphasized the need for new drugs. Squalene synthase (SQS) is an essential enzyme for the biosynthesis of protozoal sterol molecules. In this work, nineteen synthetic quinuclidines, potentially inhibitors of SQS, were tested against promastigote forms of L. chagasi and the IC50 values of the compounds were determined. The most active compounds had IC50 values of around 30 nM and induced complete growth arrest and cell lysis at sub-micromolar concentrations. We analyzed the morphological structure of the parasites treated with these compounds by transmission electron microscopy of thin sections. Treated parasites showed significant ultrastructural changes, which varied from discrete alterations to total destruction of the cells, depending on the drug concentration and the time of incubation. One important change observed was a typical swelling of the unique and highly branched mitochondrion, where the inner membrane lost its organization. There was an increase in the number of autophagosomal structures. Changes in the organization of the nuclear chromatin and alterations in the flagellar pocket and flagellar membrane were also observed.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Farnesil-Difosfato Farnesiltransferase
/
Leishmania
/
Antiprotozoários
Limite:
Animals
Idioma:
En
Revista:
Vet Parasitol
Ano de publicação:
2007
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Holanda