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Volume 24, Issue 6, Pages 621-628

Azure dyes as new photosensitizer prototypes to application in photodynamic therapy against Candida spp.

Leonardo M. Moreira,1 Juliana P. Lyon,2 Suellen M.S. Tursi,3 Isis Trajano,3 Monalisa P. Felipe,3 Maricília S. Costa,3 Máira R. Rodrigues,4 Lúcia Codognoto,5 and Hueder P.M. de Oliveira5,6

1Departamento de Engenharia de Biossistemas, Universidade Federal de São João Del Rei, São João del Rei, MG, Brazil
2Departamento de Ciências Naturais, Universidade Federal de São João Del Rei, São João del Rei, MG, Brazil
3Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraíba, São José dos Campos, SP, Brazil
4Departamento de Ciência e Tecnologia, Universidade Federal Fluminense, Polo Universitário de Rio das Ostras, Rio das Ostras, RJ, Brazil
5Universidade Camilo Castelo Branco, São José dos Campos, SP, Brazil
6Universidade Camilo Castelo Branco/Rod, Presidente Dutra Km 139–Eugênio de Melo, São José dos Campos, SP 12247-004, Brazil

Copyright © 2010 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Infections caused by Candida albicans are of increasing concern, especially considering immunodepressed patients. The toxicity of most antifungal agents, the great number of cases with recidives, as well as the emergence of resistant samples has provoked the evaluation of new forms of therapy. In this context, the photodynamic therapy (PDT) presents auspicious antimicrobial properties, stimulating the development of trials employing several kinds of photosensitizers. In the present work, the application of different kind of Azure dyes as photosensitizer in PDT against C. albicans was evaluated through instrumental measurements of electronic spectroscopy. In fact, the values of optical density were a precise indicator of the growth inhibition of the microorganisms. Indeed, Azures are phenothiazinium derivatives that constitute a very relevant class of compounds with several biomedical applications, such as photoantimicrobial therapy against local bacterial infection, tuberculosis, trypanosomiasis, malaria, Rickettsia, yeasts, viral infection n and cancer. Azure A, Azure B, Azure A thiocyanate, Azure B BF4, Azure A eosinate are the dyes tested against C. albicans. The results denoted completely distinct behaviors to the different types of Azure compound evaluated in this work. In fact, Azure A and Azure A eosinate presented significant results when irradiated with 56 J/cm2, since the growth inhibition of C. albicans reached approximately 60%. This Azure compounds have significant potential to be employed as photosensitizer (PS) in PDT, especially in cases of mucocutaneous candidosis. The spectroscopic evaluation was very effective to the detection of slight alterations in the growth of the microorganisms, denoting that this kind of analysis is an excellent alternative to determine growth inhibition of Candida albicans. The experimental data are discussed in details in agreement with recent results from literature.