Evaluation of methylene blue as photosensitizer in promastigotes of Leishmania major and Leishmania braziliensis.
The cutaneous leishmaniasis is caused by the protozoan of the genus Leishmania. It is considered by WHO as a public health issue and a neglected disease, which affects rural workers and it is also a risk to travelers in endemic areas. The conventional treatment is toxic and leads to severe side effects. The photodynamic therapy has been studied as an alternative treatment to cutaneous leishmaniasis. This study aimed to evaluate the methylene blue internalization and the impact of the PDT in the viability and morphology of Leishmania major and Leishmania braziliensis promastigote in culture medium. The fluorescence microscopy was used to determine the MB localization. To evaluate the mitochondrial activity (MTT), viability (Trypan blue test) and the morphological alterations both species were incubated with the MB in concentrations starting in 500μg/ml, in serial dilution, until 7,8μg/ml. The fluorescence microscopy demonstrated that the MB is internalized by both species after one hour of incubation. The MB presented low toxicity at the dark and the PDT was capable of decreasing the viability in more than 70% in the higher concentrations tested. The PDT also triggered significant morphological alterations in the Leishmania promastigotes. The results presented in this study are an indicative that the MB is a photosensitizer with promising potential to clinical application, besides its low cost.
['Pinto|Juliana Guerra|JG|', 'Martins|Jaciara Fagundes de Souza|JFS|', 'Pereira|André Henrique Correia|AHC|', 'Mittmann|Josane|J|', 'Raniero|Leandro José|LJ|', 'Ferreira-Strixino|Juliana|J|']
D004305:Dose-Response Relationship, Drug D004307:Dose-Response Relationship, Radiation D007892:Leishmania braziliensis D018320:Leishmania major D008018:Life Cycle Stages D008751:Methylene Blue D010778:Photochemotherapy D017319:Photosensitizing Agents D016896:Treatment Outcome
Cutaneous leishmaniasis Treatment Photodynamic therapy