Preclinical Investigation of Methylene Blue-mediated Antimicrobial Photodynamic Therapy on Leishmania Parasites Using Real-Time Bioluminescence

Author(s)

Cabral, Fernanda V. ; Sabino, Caetano P. ; Dimmer, Jesica A. ; Sauter, Ismael P. ; Cortez, Mauro J. ; Ribeiro, Martha S.

• Document type: Journal article
• Source: Photochemistry and Photobiology; v. 96, n. 3, p. 7-pg., 2019-12-17.

Abstract

Cutaneous leishmaniasis (CL) is a neglected disease that promotes destructive lesions. Difficulties in treatment are related to accessibility of drugs, resistance and toxicity. Antimicrobial photodynamic therapy (APDT) has been emerging as a promising treatment for CL. In this work, we evaluated methylene blue (MB)-mediated APDT (MB-APDT) on Leishmania amazonensis in vitro and in vivo by bioluminescence technique. In vitro, MB-APDT was performed using a red LED (lambda = 660 +/- 11 nm, 100 mW cm(-2)) and MB (100 mu m) at different light doses. In vivo, mice were infected and 4 weeks later, randomly divided into three groups: control, APDT 1 (single session) and APDT 2 (two sessions of MB-APDT). MB was used at 100 mu m and energy dose was established at 150 J cm(-2). Parasite burden, lesion size and pain were evaluated weekly for 4 weeks. In vitro, lethal dose for 90% parasite inactivation was achieved at 48.8 J cm(-2). In vivo, although APDT 1 and APDT 2 groups have showed similar parasite burden after 4 weeks, two sessions were clinically better, especially considering the inflammatory process associated to CL. Our findings reinforce MB-APDT as a cost-effective treatment to combat CL. (AU)

• FAPESP's process: 12/24105-3 - Immunobiology of Leishmania spp.: study of the role of CD200 and biogenesis of parasitophorous vacuole in fagocitic cells infected by Leishmania
• Grantee: Mauro Javier Cortez Véliz
• Support Opportunities: Research Grants - Young Investigators Grants