ORIGINAL ARTICLE In vitro evaluation of photodynamic therapy using curcumin on Leishmania major and Leishmania braziliensis Juliana Guerra Pinto 1 & Letícia Correa Fontana 1 & Marco Antonio de Oliveira 2 & Cristina Kurachi 3 & Leandro José Raniero 4 & Juliana Ferreira-Strixino 1 Received: 1 December 2015 /Accepted: 18 March 2016 # Springer-Verlag London 2016 Abstract Cutaneous leishmaniasis is an infectious disease caused by the Leishmania protozoan. The conventional treatment is long-lasting and aggressive, in addition to causing harmful effect. Photodynamic therapy has emerged as a promising alternative treatment, which al- lows local administration with fewer side effects. This study investigated the photodynamic activity of curcumin on Leishmania major and Leishmania braziliensis promastigote. Both species were submitted to incubation with curcumin in serial dilutions from 500 μg/ml up to 7.8 μg/ml. Control groups were kept in the dark while PDT groups received a fluency of 10 J/cm 2 at 450 nm. Mitochondrial activity was assessed by MTT assay 18 h after light treatment, and viability was measured by Trypan blue dye exclusion test. Morphological alterations were observed by Giemsa staining. Confocal microscopy showed the up- take of curcumin by both tested Leishmania species. Mitochondrial activity was inconclusive to determine vi- ability; however, Trypan blue test was able to show that curcumin photodynamic treatment had a significant effect on viability of parasites. The morphology of promastigotes was highly affected by the photodynamic therapy. These results indicated that curcumin may be a promising alternative photosensitizer, because it presents no toxicity in the dark; however, further tests in co-culture with macro- phages and other species of Leishmania should be con- ducted to determine better conditions before in vivo tests are performed. Keywords Photodynamic therapy . Cutaneous leishmaniasis . Leishmania major . Leishmania braziliensis . Curcumin Introduction Leishmaniases are infectious diseases caused by protozoan of the genus Leishmania and transmitted by the bite of an infected phlebotomine female [ 1, 2]. More than 20 species of Leishmania are distributed geographically across the globe, and different species can cause different manifestations of this dis- ease, including cutaneous, mucosal, or visceral, which is the most dangerous form of the disease. Cutaneous leishmaniasis (CL) affects mostly rural workers in tropical regions, but also frequent- ly affects travelers who visit transmission areas [2–5]. The World Health Organization considers CL a public health issue present in more than 80 countries [6]. Between 1999 and 2008, Brazil registered 269,122 cases of CL, which was the highest preva- lence rate in the Americas [7, 8]. The conventional treatment is with Antimonials, Pentamidine, and antibiotics, and although these treatments can be effective, there are many side effects and restrictions. * Juliana Ferreira-Strixino juferreira@univap.br; jgbiomd@gmail.com 1 Laboratório de Terapia Fotodinâmica, Instituto de Pesquisa e desenvolvimento, Univap-Universidade do Vale do Paraíba, Av. Shishima Hifumi, 2911, 12244-000 São José dos Campos, SP, Brazil 2 Laboratório de Parasitologia e Biotecnologia, Instituto de Pesquisa e desenvolvimento, Univap-Universidade do Vale do Paraíba, Av. Shishima Hifumi, 2911, 12244-000 São José dos Campos, SP, Brazil 3 Laboratório de Biofotônica, Instituto de Física de São Carlos, USP-Universidade de São Paulo, USP São Carlos-Campus 1, Avenida Trabalhador São-Carlense, 400 - Parque Arnold Schimidt, São Carlos, SP 13566, Brazil 4 Laboratório de Nanossensores, Instituto de Pesquisa e desenvolvimento, Univap-Universidade do Vale do Paraíba, Av. Shishima Hifumi, 2911, 12244-000 São José dos Campos, SP, Brazil Lasers Med Sci DOI 10.1007/s10103-016-1928-5