RESUMO
Photodynamic therapy (PDT) with photosensitizer methylene blue was applied to Leishmania braziliensis, and Fourier transform infrared (FTIR) spectroscopy was used to study biochemical changes in the parasite after PDT in comparison to untreated (C), only irradiation (I), and only photosensitizer (PS). Spectral analysis suggests increase in lipids, proteins, and protein secondary structures in PDT compared with C and decrease in nucleic acids and carbohydrates. Interestingly, these trends are different from PDT of Leishmania major species, wherein lipids decrease; there are minimal changes in secondary structures and increase in nucleic acids and carbohydrates. The study thus suggests possibility of different biomolecular players/pathways in PDT-induced death of L. braziliensis and L. major.
Assuntos
Leishmania braziliensis/metabolismo , Azul de Metileno/farmacologia , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier , Leishmania braziliensis/efeitos dos fármacos , Leishmania braziliensis/efeitos da radiação , Proteínas de Protozoários/metabolismoAssuntos
Carboidratos/análise , Leishmania major/efeitos dos fármacos , Leishmaniose/tratamento farmacológico , Lipídeos/análise , Azul de Metileno/farmacologia , Fotoquimioterapia/métodos , Proteínas/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Inibidores Enzimáticos/farmacologia , Humanos , Leishmaniose/parasitologia , Luz , Conformação ProteicaRESUMO
Paracoccidioides brasiliensis (P. brasiliensis) is a thermo-dimorphic fungus that causes paracoccidioidomycosis. Brazil epidemiological data shows that endemic areas are the subtropical regions, especially where agricultural activities predominate such as the Southeast, South, and Midwest. There are several tests to diagnose paracoccidioidomycosis, but they have many limitations such as low sensitivity, high cost, and a cross-reacting problem. In this work, gold nanoprobes were used to identify P. brasiliensis as an alternative diagnostic technique, which is easier to apply, costs less, and has great potential for application. The specific Ribosomal sequence of P. brasiliensis DNA was amplified and used to design the nanoprobes using a thiol-modified oligonucleotide. The results of positive and negative tests were done by UV-visible and Fourier Transform Infrared (FT-IR) measurements. The deconvolution of FT-IR sample spectra showed differences in the vibrational modes from the hydrogen bridge NHN and NHO bands that form the double helix DNA for samples matching the DNA sequence of nanoprobes that could be used to classify the samples.