A new focus of cutaneous leishmaniasis due to Leishmania amazonensis in a Sub Andean region of Bolivia

In the past few years, induction of protective immunity to cutaneous leishmaniasis has been attempted by many researchers using a variety of antigenic preparations, such as living promastigotes or promastigote extracts, partially purified, or defined proteins. In this study, eleven proteins from Leishmania (Leishmania) amazonensis (LLa) with estimated molecular mass ranging from 97 to 13.5kDa were isolated by polyacrylamide gel electrophoresis and electro-elution. The proteins were associated as vaccine in different preparations with gp63 and BCG (Bacilli Calmette-Guérin). The antigenicity of these vaccines was measured by their ability to induce the production of IFN-g by lymphocyte from subjects vaccinated with Leishvacinâ . The immunogenicity was evaluated in vaccinated mice. C57BL/10 mice were vaccinated with three doses of each vaccine consisting of 30 mg of each protein at 15 days interval. One hundred mg of live BCG was only used in the first dose. Seven days after the last dose, they received a first challenge infection with 105 infective promastigotes and four months later, a second challenge was done. Two months after the second challenge, 42.86% of protection was obtained in the group of mice vaccinated with association of proteins of gp63+46+22kDa, gp63+13.5+25+42kDa, gp63+46+42kDa, gp63+66kDa, and gp63+97kDa; 57.14% of protection was demonstrated with gp63+46+97+13.5kDa, gp63+46+97kDa, gp63+46+33kDa, and 71.43% protection for gp63 plus all proteins. The vaccine of gp63+46+40kDa that did not protect the mice, despite the good specific stimulation of lymphocytes (LSI = 7.60) and 10.77UI/ml of IFN-g production. When crude extract of L. (L.) amazonensis was used with BCG a 57.14% of protection was found after the first challenge and 28.57% after the second, the same result was observed for gp63. The data obtained with the vaccines can suggest that the future vaccine probably have to contain, except the 40kDa, a cocktail of proteins that would protect mice against cutaneous leishmaniasis.

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Evaluation of different total Leishmania amazonensis antigens for the development of a first-generation vaccine formulated with a Toll-like receptor-3 agonist to prevent cutaneous leishmaniasis

Memórias do Instituto Oswaldo Cruz ◽

10.1590/0074-02760200067 ◽

2020 ◽

Vol 115 ◽

Author(s):

María José Germanó ◽

Esteban Sebastián Lozano ◽

María Victoria Sanchez ◽

Flavia Alejandra Bruna ◽

María Fernanda García-Bustos ◽

...

Keyword(s):

Cutaneous Leishmaniasis ◽

First Generation ◽

Leishmania Amazonensis ◽

Toll Like Receptor ◽

Generation Vaccine

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Endlicheria bracteolata (Meisn.) Essential Oil as a Weapon Against Leishmania amazonensis: In Vitro Assay

Molecules ◽

10.3390/molecules24142525 ◽

2019 ◽

Vol 24 (14) ◽

pp. 2525 ◽

Cited By ~ 5

Author(s):

Mariana Margatto Rottini ◽

Ana Claudia Fernandes Amaral ◽

José Luiz Pinto Ferreira ◽

Edinilze Souza Coelho Oliveira ◽

Jefferson Rocha de Andrade Silva ◽

...

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Flow Cytometry ◽

Essential Oil ◽

Cutaneous Leishmaniasis ◽

Leishmania Amazonensis ◽

Vitro Assay ◽

Transmission Electron ◽

Biological Potential ◽

Intracellular Amastigote

The difficulties encountered and the numerous side effects present in the treatment of cutaneous leishmaniasis have encouraged the research for new compounds that can complement or replace existing treatment. The growing scientific interest in the study of plants, which are already used in folk remedies, has led our group to test Endlicheria bracteolata essential oil against Leishmania amazonensis. Several species of the Lauraceae family, or their compounds, have relevant antiprotozoal activities Therefore, the biological potential on L. amazonensis forms from the essential oil of Endlicheria bracteolata leaves was verified for the first time in that work. The antileishmanial activity was evaluated against promastigotes and intracellular amastigotes, and cytotoxicity were performed with J774.G8, which were incubated with different concentrations of E. bracteolata essential oil. Transmission electron microscopy and flow cytometry were performed with E. bracteolata essential oil IC50. Promastigote forms showed E. bracteolata essential oil IC50 of 7.945 ± 1.285 µg/mL (24 h) and 6.186 ± 1.226 µg/mL (48 h), while for intracellular amastigote forms it was 3.546 ± 1.184 µg/mL (24 h). The CC50 was 15.14 ± 0.090 µg/mL showing that E. bracteolata essential oil is less toxic to macrophages than to parasites. Transmission electron microscopy showed that E. bracteolata essential oil treatment is capable of inducing mitochondrial damage to promastigote and intracellular amastigote forms, while flow cytometry showed ΔѰm disruption in treated parasites. These results could bring about new possibilities to develop products based on E. bracteolata essential oil to treat cutaneous leishmaniasis, especially for people who cannot receive the conventional therapy.

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Lipid-core nanocapsules increase the oral efficacy of quercetin in cutaneous leishmaniasis

Parasitology ◽

10.1017/s003118201700097x ◽

2017 ◽

Vol 144 (13) ◽

pp. 1769-1774 ◽

Cited By ~ 9

Author(s):

A. J. SOUSA-BATISTA ◽

F. S. POLETTO ◽

C. I. M. S. PHILIPON ◽

S. S. GUTERRES ◽

A. R. POHLMANN ◽

...

Keyword(s):

Cutaneous Leishmaniasis ◽

Aspartate Aminotransferase ◽

Alanine Aminotransferase ◽

Serum Levels ◽

Leishmania Amazonensis ◽

Oral Drug ◽

Lipid Core ◽

Oral Doses

SUMMARYNew oral treatments are needed for all forms of leishmaniasis. Here, the improved oral efficacy of quercetin (Qc) and its penta-acetylated derivative (PQc) was evaluated in cutaneous leishmaniasis after encapsulation in lipid-core nanocapsules (LNCs) of poly(ε-caprolactone). Leishmania amazonensis-infected BALB/c mice were given 51 daily oral doses of free drugs (16 mg kg−1) or LNC-loaded drugs (0·4 mg kg−1). While treatment with free Qc reduced the lesion sizes and parasite loads by 38 and 71%, respectively, LNC-Qc produced 64 and 91% reduction, respectively. The antileishmanial efficacy of PQc was similar but not as potently improved by encapsulation as Qc. None of the treatments increased aspartate aminotransferase, alanine aminotransferase or creatinine serum levels. These findings indicate that when encapsulated in LNC, Qc and, to a lesser extent, PQc can safely produce an enhanced antileishmanial effect even at a 40-fold lower dose, with implications for the development of a new oral drug for cutaneous leishmaniasis.

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