Assessment of Leishmania major and Leishmania braziliensis promastigote viability after photodynamic treatment with aluminum phthalocyanine tetrasulfonate (AlPcS4)

Pinto JG (1), Soares CP (2), Mittmann J (1)

(1) Laboratory of Parasitology and Biotechnology, Research and Development Institute, Vale do Paraíba University (UNIVAP), São José dos Campos, São Paulo State, Brazil; (2) Laboratory of Cell Culture, Research and Development Institute, Vale do Paraíba University (UNIVAP), São José dos Campos, São Paulo State, Brazil.

Abstract: Cutaneous leishmaniasis is an infectious disease caused by protozoans of the genus Leishmania, which is transmitted through the bite of hematophagous insects of the genus Lutzomyia. This study aimed at testing in vitro the phototoxic effect of aluminum phthalocyanine tetrasulfonate (AlPcS4) on the viability of Leishmania major and Leishmania braziliensis. Stationary phase promastigote forms were treated with AlPcS4 at 1.0 µM and 10.0 µM and incubated for one hour. Then 659 nm laser was applied at 5 and 10 J/cm². Parasite viability was determined by differential count using the trypan blue dye exclusion method and by monitoring growth curves for nine days. Trypan blue exclusion assay showed a significant reduction of viable parasites compared to controls, L. major seemed more sensitive to the toxic effects of AlPcS4 in the dark. The most effective photodynamic therapy (PDT) was obtained with AlPcS4 at 10.0 µM and 10 J/cm² whereas L. braziliensis showed the highest mortality rate after treatment.

Key words: cutaneous leishmaniasis, antiparasitic agents, Leishmania major, Leishmania braziliensis, AlPcS4, photodynamic therapy.

ACKNOWLEDGMENTS

The authors are grateful to Dr. Ângela K. Cruz for providing Leishmania major parasites, Dr. Mário Steindel for Leishmania braziliensis parasites, Dr. Cibelle Barbosa Lopes for laser equipment, Dr. Newton Soares from the Laboratory of Cell and Tissue Biology, Maira Gaspar Tosato for laser measurement equipment, and Prof. A. A. Martin for the use of the Espectra Pro 2500i® spectrometer (PiAction). We are also grateful to the Coordination for the Improvement of Higher Education Personnel (CAPES) for the fellowship offered to Juliana Guerra Pinto and Valeparaibana Education Foundation (FVE) for their financial support.

COPYRIGHT

© CEVAP 2011

SUBMISSION STATUS

Received: February 1, 2011.

Accepted: May 26, 2011.

Abstract published online: June 1, 2011.

Full paper published online: August 31, 2011.

CONFLICTS OF INTEREST

There are no conflicts of interest.

FINANCIAL SOURCE

Valeparaibana Education Foundation (FVE) provided the financial grants.

ETHICS COMMITTEE APPROVAL

This study was approved by the Ethics Committee of Vale do Paraíba University (UNIVAP), process number I034CEP/2009.

CORRESPONDENCE TO

JOSANE MITTMANN, Instituto de Pesquisa e desenvolvimento, UNIVAP, Av. Shishima Hifumi, 2911, Urbanova, São José dos Campos, SP, 12244-000, Brazil. Phone: +55 12 3947 1160. Email: mittmann@univap.br.