Evaluation of photodynamic therapy action in Leishmania sp.: in vitro study

Abstract

Leishmaniasis is infectious diseases caused by the Leishmania protozoa by the genus Leishmania that present two evolutive ways: one flagellate form, the promastigote, responsabe for infect and a not flagellate form, the amastigote, form in that parasite multiplies at the host. This disease could manifest in three different forms: cutaneous, mucocutaneous or visceral, being the last one the most agressive form. Cutaneous leishmaniasis is present in 80 countrys and is considerated by World health organization a public health problem with estimative for 65.000 new cases at year in Brazil that is the country with biggest prevalence in the american continent. Conventional treatment is performed with antimonials, Pentamidines and antibiotics however these treatments are agressive to the patient leading to several side effects as nausea, vomit and myalgia. Photodynamic therapy associates a photosensitive substance with a light source and tissue oxygen to induce formation of reactive oxygen species leading to a death of target cells by apoptosis. It's a attractive alternative to treat cutaneous leishmaniasis due to selectivity of the treatment field enabling to treat each wound individually without the impact caused when the patient is treated with conventional drugs administered systemically. The aim of this study is to test the phototoxic effect of chlorin, porphyrin, azulene and curcumin in Leishmania amazonensis and Leishmania braziliensis promastigotes and co-cultive with macrophages and parasites, using confocal microscopy, scanning and transmission microscopy, besides the morphological analysis and FT-IR, to verify the potential those compounds to treat cutaneous leishmaniasis and in the future performe in vivo tests if the in vitro results were favorable. (AU)