Evaluation of photodynamic therapy against Leishmania tropica promastigotes using different photosensitizers

Abstract

Background: Photodynamic therapy is a two-step procedure, involving the use of photosensitizing agents followed by selective illumination of the target lesion with visible light. Photodynamic therapy has been described recently as a promising strategy for treatment of leishmaniasis. This study aims to evaluate the in vitro phototoxic, morphological, and apoptotic effect of methylene blue, toluidine blue, chloro-aluminum phthalocyanine, and pheophorbide a-mediated photodynamic therapy on the viability of Leishmania tropica promastigotes.Methods: Parasites were treated with methylene blue, toluidine blue, chloroaluminum phthalocyanine, and pheophorbide a or/and methylene blue, toluidine blue, chloro-aluminum phthalocyanine, and pheophorbide a-mediated photodynamic therapy, and cell proliferation, morphological changes, and apoptosis were evaluated by XTT, giemsa staining, DAPI staining, and DNA fragmentation, respectively.Results: Parasite viability was significantly different in between the groups treated with methylene blue, toluidine blue, and pheophorbide a, with or without irradiation. chloro-aluminum phthalocyanine treatment did not lead to any alterations in cell viability in Leishmania tropica promastigotes with or without irradiation. DAPI staining results indicated that apoptotic bodies and nucleus fragmentation started to be visible in methylene blue, chloro-aluminum phthalocyanine, and pheophorbide a-mediated photodynamic therapy groups. DNA ladder pattern which is used to define apoptosis was observed in irradiated methylene blue, chloro-aluminum phthalocyanine, and pheophorbide a groups. Conclusions:The results revealed that apoptosis-induced cell death was observed in Leishmania tropica promastigotes after the application of photosensitizers in combination with light irradiation.

Photodynamic Therapy Applications in Cancer, Infections and Cardiovascular Disease

“…Chloro-aluminum phthalocyanine (PC) treatment did not lead to any alterations in cell viability in L. tropica promastigotes with or without irradiation. DAPI staining indicated that apoptotic bodies and nuclear fragmentation were observed in MB-, chloro-Al PC-, and Pheo a-mediated PDT groups [166].…”