Leishmania tropica infection of the ear treated with photodynamic therapy

Marcolino

et al. 2021

RSD

Photodynamic Therapy (PDT) consists of using a light source and a photosensitive drug at an appropriate wavelength and molecular oxygen to trigger cell death through the production of reactive oxygen species. Because it is a localised therapy, PDT is shown to be ideal for skin diseases. American cutaneous Leishmaniasis (ACL) is a highly prevalent protozoan disease worldwide that presents different clinical evolutions and may result in ulcerations and disfiguring lesions on the skin and cartilage. This study was aimed at evaluating the effect in vitro of PDT applied serially using curcumin as a photosensitiser. For this, a concentration of 125 µg.mL-1 of curcumin was used on Leishmania braziliensis and Leishmania amazonensis strains, with a light fluence of 10 J.cm-2 and irradiance of 110 mW.cm-2. The tests done were viability analysis by trypan blue exclusion test, analysis of photosensitizer (PS) internalization by confocal microscopy and morphological alterations by May-Grunwald/Giemsa staining. We observed that there was internalisation of the PS before the first and second application of PDT, with L. braziliensis and L. amazonensis strains mortality of 92% and 82% respectively, after the second application, and induction of alterations in the structural conformation, such as cell size and non-evidence of nucleus and flagellum, demonstrating that PDT was effective. We conclude that serial PDT was effective in inducing the mortality of promastigotes forms of L. braziliensis and L. amazonensis in vitro, thus highlighting its potential for the treatment of leishmaniasis.

Section: Discussionsupporting

confidence: 92%

“…In other ways, serial PDT (sPDT) has shown even more promise as it gives more effective results in achieving a cure for leishmaniasis, as it consists of more than one application of the therapy (Johansen, Jernec & Fabrícius, 2019;Goldin et al, 2020).…”

Section: Introductionmentioning

confidence: 99%

Effect of serial photodynamic therapy with curcumin on Leishmania braziliensis and Leishmania amazonensis promastigotes

Marcolino

et al. 2021

RSD

“…The U.S. military suspended their development of topical paromomycin cream, and expanded access is not currently available. Photodynamic therapy and thermotherapy continue to look promising for treatment of Old World cutaneous leishmaniasis [ 60 , 61 ]. On the horizon, the Drugs for Neglected Diseases Initiative is exploring a nitroimidazole 0690 for VL and a modulatory CpG oligonucleotide (CpG-D35) for complicated CL to improve efficacy of parasite-directed chemotherapy [ 62 , 63 ].…”

Section: Emerging Issues Relevant To Leishmaniasis In the United Smentioning

confidence: 99%

Leishmaniasis in the United States: Emerging Issues in a Region of Low Endemicity

Curtin

Aronson

2021

Microorganisms

Leishmaniasis, a chronic and persistent intracellular protozoal infection caused by many different species within the genus Leishmania, is an unfamiliar disease to most North American providers. Clinical presentations may include asymptomatic and symptomatic visceral leishmaniasis (so-called Kala-azar), as well as cutaneous or mucosal disease. Although cutaneous leishmaniasis (caused by Leishmania mexicana in the United States) is endemic in some southwest states, other causes for concern include reactivation of imported visceral leishmaniasis remotely in time from the initial infection, and the possible long-term complications of chronic inflammation from asymptomatic infection. Climate change, the identification of competent vectors and reservoirs, a highly mobile populace, significant population groups with proven exposure history, HIV, and widespread use of immunosuppressive medications and organ transplant all create the potential for increased frequency of leishmaniasis in the U.S. Together, these factors could contribute to leishmaniasis emerging as a health threat in the U.S., including the possibility of sustained autochthonous spread of newly introduced visceral disease. We summarize recent data examining the epidemiology and major risk factors for acquisition of cutaneous and visceral leishmaniasis, with a special focus on implications for the United States, as well as discuss key emerging issues affecting the management of visceral leishmaniasis.

“…Therefore, PDT may represent an important alternative since it presents minimum side effects and can be easily implemented. Clinical applications of PDT in CL treatment using PS, such as methyl-ALA, is widely reported, indicating the potential of this therapy [8][9][10]. However, it is important to consider that if the treatment cost is low, the access to the therapy for the poorest population will be greater, especially in underdeveloped countries such as Brazil, Colombia, Afghanistan, Peru, and Bolivia [1,11].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of the Photodynamic Therapy with Curcumin on L. braziliensis and L. major Amastigotes

et al. 2021

Cutaneous leishmaniasis (CL) is a neglected disease prevalent in tropical countries with the ability to cause skin lesions. Photodynamic therapy (PDT) represents a specific and topical option for the treatment of these lesions. This study evaluated the response of macrophages infected with L. braziliensis and L. major to PDT with curcumin. Curcumin concentrations were evaluated in serial dilutions from 500.0 to 7.8 µg/mL using LED (λ = 450 ± 5 nm), with a light dose of 10 J/cm2. The Trypan blue viability test, ultrastructural analysis by scanning electron microscopy (SEM), mitochondrial polarity by Rhodamine 123 (Rho 123), curcumin internalization by confocal microscopy, and counting of the recovered parasites after the PDT treatment were performed. The lowest concentrations of curcumin (15.6 and 7.8 µg/mL) presented photodynamic inactivation. Cell destruction and internalization of curcumin in both macrophages and intracellular parasites were observed in microscopy techniques. In addition, an increase in mitochondrial membrane polarity and a decrease in the number of parasites recovered was observed in the PDT groups. This study indicates that PDT with curcumin has the potential to inactivate infected macrophages and might act as a basis for future in vivo studies using the parameters herein discussed.