Evaluation of photodynamic therapy with methylene blue in Leishmania SP: in vitro study

Abstract

The leishmaniasis are a complex chronic diseases, not contagious, which are caused by various species of the protozoan Leishmania genus, which has two forms during its life cycle: promastigote and amastigote. They are transmitted through the bite of sand flies insects, and particularly attack the mononuclear phagocyte system. According to the World Health Organization (WHO), the American Cutaneous Leishmaniasis (ACL) is a public health problem, and considered one of the six most important endemic infectious and parasitic diseases. The treatment of ACL is performed mainly with pentavalent antimonials, but these medications have adverse effects on the patient during treatment and, therefore, new alternative treatments are being developed, for example, photodynamic therapy (PDT). The PDT is a photochemical reaction that combines light, photosensitizer (FS) and oxygen to destroy selectively and locally abnormal tissue, through the formation of reactive oxygen species (ROS), which induce cell death. One FS that has been used as a therapeutic agent is Methylene Blue, which is well known as a histological stain and has bacteriostatic function. The aim of this study is to evaluate in vitro phototoxic effects of Methylene Blue as a alternative treatment of Cutaneous Leishmaniasis ( ACL) with Photodynamic Therapy (PDT) in promastigotes of the strains of Leishmania major and Leishmania braziliensis and co- cultive with macrophages infected with the same species.