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Advances in Development of New Treatment for Leishmaniasis. BIOMED RESEARCH INTERNATIONAL 2015; 2015:815023. [PMID: 26078965 PMCID: PMC4442256 DOI: 10.1155/2015/815023] [Citation(s) in RCA: 123] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 04/07/2015] [Accepted: 04/18/2015] [Indexed: 01/01/2023]
Abstract
Leishmaniasis is a neglected infectious disease caused by several different species of protozoan parasites of the genus Leishmania. Current strategies to control this disease are mainly based on chemotherapy. Despite being available for the last 70 years, leishmanial chemotherapy has lack of efficiency, since its route of administration is difficult and it can cause serious side effects, which results in the emergence of resistant cases. The medical-scientific community is facing difficulties to overcome these problems with new suitable and efficient drugs, as well as the identification of new drug targets. The availability of the complete genome sequence of Leishmania has given the scientific community the possibility of large-scale analysis, which may lead to better understanding of parasite biology and consequent identification of novel drug targets. In this review we focus on how high-throughput analysis is helping us and other groups to identify novel targets for chemotherapeutic interventions. We further discuss recent data produced by our group regarding the use of the high-throughput techniques and how this helped us to identify and assess the potential of new identified targets.
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Sharlow ER, Close D, Shun T, Leimgruber S, Reed R, Mustata G, Wipf P, Johnson J, O'Neil M, Grögl M, Magill AJ, Lazo JS. Identification of potent chemotypes targeting Leishmania major using a high-throughput, low-stringency, computationally enhanced, small molecule screen. PLoS Negl Trop Dis 2009; 3:e540. [PMID: 19888337 PMCID: PMC2765639 DOI: 10.1371/journal.pntd.0000540] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2009] [Accepted: 10/02/2009] [Indexed: 11/21/2022] Open
Abstract
Patients with clinical manifestations of leishmaniasis, including cutaneous leishmaniasis, have limited treatment options, and existing therapies frequently have significant untoward liabilities. Rapid expansion in the diversity of available cutaneous leishmanicidal chemotypes is the initial step in finding alternative efficacious treatments. To this end, we combined a low-stringency Leishmania major promastigote growth inhibition assay with a structural computational filtering algorithm. After a rigorous assay validation process, we interrogated ∼200,000 unique compounds for L. major promastigote growth inhibition. Using iterative computational filtering of the compounds exhibiting >50% inhibition, we identified 553 structural clusters and 640 compound singletons. Secondary confirmation assays yielded 93 compounds with EC50s ≤ 1 µM, with none of the identified chemotypes being structurally similar to known leishmanicidals and most having favorable in silico predicted bioavailability characteristics. The leishmanicidal activity of a representative subset of 15 chemotypes was confirmed in two independent assay formats, and L. major parasite specificity was demonstrated by assaying against a panel of human cell lines. Thirteen chemotypes inhibited the growth of a L. major axenic amastigote-like population. Murine in vivo efficacy studies using one of the new chemotypes document inhibition of footpad lesion development. These results authenticate that low stringency, large-scale compound screening combined with computational structure filtering can rapidly expand the chemotypes targeting in vitro and in vivo Leishmania growth and viability. Leishmaniasis is a parasitic disease with cutaneous, mucocutaneous and visceral clinical manifestations, depending on the Leishmania spp. and human host. Globally, there are 350 million people at risk of leishmaniasis, but current treatment options rely predominantly on ancient pentavalent antimonials, which have the potential to cause serious systemic toxicity. Our research focuses on the rapid expansion of potential anti-leishmanial compounds that could function as novel chemical structures for future drug development and offer additional therapeutic options to patients with leishmaniasis. We combined high throughput screening methodologies with computational algorithms and multiple confirmatory assay formats to identify and characterize new potent L. major promastigote growth inhibitors, including one that displays in vivo activity without toxicity to human cells. Our use of a large, broadly distributed compound library enabled the identification of these new chemotypes. In addition, since this chemical library is publicly available and annotated, we were able to cross-query archived bioassays and to identify new molecular targets that may be involved in L. major growth and viability as well as identify new protein targets for future leishmanicidal drug discovery.
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Affiliation(s)
- Elizabeth R. Sharlow
- University of Pittsburgh Drug Discovery Institute and the Pittsburgh Molecular Library Screening Center, Pittsburgh, Pennsylvania, United States of America
- Departments of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - David Close
- University of Pittsburgh Drug Discovery Institute and the Pittsburgh Molecular Library Screening Center, Pittsburgh, Pennsylvania, United States of America
| | - Tongying Shun
- University of Pittsburgh Drug Discovery Institute and the Pittsburgh Molecular Library Screening Center, Pittsburgh, Pennsylvania, United States of America
| | - Stephanie Leimgruber
- University of Pittsburgh Drug Discovery Institute and the Pittsburgh Molecular Library Screening Center, Pittsburgh, Pennsylvania, United States of America
| | - Robyn Reed
- University of Pittsburgh Drug Discovery Institute and the Pittsburgh Molecular Library Screening Center, Pittsburgh, Pennsylvania, United States of America
| | - Gabriela Mustata
- Department of Computational Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Peter Wipf
- University of Pittsburgh Drug Discovery Institute and the Pittsburgh Molecular Library Screening Center, Pittsburgh, Pennsylvania, United States of America
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Jacob Johnson
- Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Michael O'Neil
- Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Max Grögl
- Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Alan J. Magill
- Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - John S. Lazo
- University of Pittsburgh Drug Discovery Institute and the Pittsburgh Molecular Library Screening Center, Pittsburgh, Pennsylvania, United States of America
- Departments of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
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Abstract
BACKGROUND Leishmaniasis is a disease produced by several species of protozoa of the Leishmania genus. These protozoa are injected into the human bloodstream by sandflies. The symptomathology, either cutaneous, mucocutaneous or visceral, depends on the infective species and the immune status of the patient. Antimonial drugs are the mainstay treatment for all the clinical forms of the disease. Amphotericin B is the second-choice drug. METHODS We report two clinical cases of cutaneous leishmaniasis treated with itraconazole. One case was a relapsing form unresponsive to conventional therapy. RESULTS Both patients achieved fast resolution of their lesions with no secondary effects. CONCLUSIONS Itraconazole may be a valid option for the treatment of cutaneous leishmaniasis, mainly in those cases unresponsive to conventional drugs.
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Abstract
The World Health Organization estimates that approximately 400,000 new cases of leishmaniasis occur worldwide each year. Cutaneous leishmaniasis is being encountered more frequently in the United States because of increasing travel and immigration from endemic areas. The indications for treatment and recommended treatment regimens reported in the infectious disease and dermatology literature vary widely. We examine both classic and newly developed therapeutic agents and modalities for cutaneous leishmaniasis. Proper therapy depends on species identification. New World leishmaniasis, in general, requires more aggressive therapy; parenteral antimonials are the drugs of choice. Physical modalities may suffice in most cases of Old World leishmaniasis because of its strong tendency toward spontaneous resolution.
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Affiliation(s)
- A B Koff
- Department of Dermatology, Baylor College of Medicine, Houston, TX 77030-3498
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