Twice neglected? Neglected diseases in neglected populations

Neglected Diseases (NDs) affect million of people, especially the poorest population around the world. Several efforts to an effective treatment have proved insufficient at the moment. In this context, triazole derivatives have shown great relevance in medicinal chemistry due to a wide range of biological activities. This review aims to describe some of the most relevant and recent research focused on 1,2,3- and 1,2,4-triazolebased molecules targeting four expressive NDs: Chagas disease, Malaria, Tuberculosis and Leishmaniasis.

Privileged Structures in the Design of Potential Drug Candidates for Neglected Diseases

Current Medicinal Chemistry ◽

10.2174/0929867324666171023163752 ◽

2019 ◽

Vol 26 (23) ◽

pp. 4323-4354 ◽

Cited By ~ 9

Author(s):

Ana Cristina Lima Leite ◽

José Wanderlan Pontes Espíndola ◽

Marcos Veríssimo de Oliveira Cardoso ◽

Gevanio Bezerra de Oliveira Filho

Keyword(s):

Biologically Active ◽

Neglected Diseases ◽

Financial Return ◽

Drug Candidates ◽

Lead Compounds ◽

Wide Range ◽

Methods Of Synthesis ◽

Current Therapies ◽

Resistant Strains ◽

Privileged Structures

Background: Privileged motifs are recurring in a wide range of biologically active compounds that reach different pharmaceutical targets and pathways and could represent a suitable start point to access potential candidates in the neglected diseases field. The current therapies to treat these diseases are based in drugs that lack of the desired effectiveness, affordable methods of synthesis and allow a way to emergence of resistant strains. Due the lack of financial return, only few pharmaceutical companies have been investing in research for new therapeutics for neglected diseases (ND). Methods: Based on the literature search from 2002 to 2016, we discuss how six privileged motifs, focusing phthalimide, isatin, indole, thiosemicarbazone, thiazole, and thiazolidinone are particularly recurrent in compounds active against some of neglected diseases. Results: It was observed that attention was paid particularly for Chagas disease, malaria, tuberculosis, schistosomiasis, leishmaniasis, dengue, African sleeping sickness (Human African Trypanosomiasis - HAT) and toxoplasmosis. It was possible to verify that, among the ND, antitrypanosomal and antiplasmodial activities were between the most searched. Besides, thiosemicarbazone moiety seems to be the most versatile and frequently explored scaffold. As well, phthalimide, isatin, thiazole, and thiazolidone nucleus have been also explored in the ND field. Conclusion: Some described compounds, appear to be promising drug candidates, while others could represent a valuable inspiration in the research for new lead compounds.

Nanoemulsions Loaded with Amphotericin B: Development, Characterization and Leishmanicidal Activity

Current Pharmaceutical Design ◽

10.2174/1381612825666190705202030 ◽

2019 ◽

Vol 25 (14) ◽

pp. 1616-1622 ◽

Cited By ~ 1

Author(s):

Gabriela Muniz Félix Araújo ◽

Alana Rafaela Albuquerque Barros ◽

João Augusto Oshiro-Junior ◽

...

Keyword(s):

Amphotericin B ◽

Average Diameter ◽

Isopropyl Myristate ◽

Neglected Diseases ◽

Clinical Form ◽

Hydrophobic Compounds ◽

Internal Phase ◽

Oil In Water ◽

Spherical Structures ◽

Lipid Formulations

Leishmaniasis is one of the most neglected diseases in the world. Its most severe clinical form, called visceral, if left untreated, can be fatal. Conventional therapy is based on the use of pentavalent antimonials and includes amphotericin B (AmB) as a second-choice drug. The micellar formulation of AmB, although effective, is associated with acute and chronic toxicity. Commercially-available lipid formulations emerged to overcome such drawbacks, but their high cost limits their widespread use. Drug delivery systems such as nanoemulsions (NE) have proven ability to solubilize hydrophobic compounds, improve absorption and bioavailability, increase efficacy and reduce toxicity of encapsulated drugs. NE become even more attractive because they are inexpensive and easy to prepare. The aim of this work was to incorporate AmB in NE prepared by sonicating a mixture of surfactants, Kolliphor® HS15 (KHS15) and Brij® 52, and an oil, isopropyl myristate. NE exhibited neutral pH, conductivity values consistent with oil in water systems, spherical structures with negative Zeta potential value, monomodal size distribution and average diameter of drug-containing droplets ranging from 33 to 132 nm. AmB did not modify the thermal behavior of the system, likely due to its dispersion in the internal phase. Statistically similar antileishmanial activity of AmB-loaded NE to that of AmB micellar formulation suggests further exploring them in terms of toxicity and effectiveness against amastigotes, with the aim of offering an alternative to treat visceral leishmaniasis.

Significance of Lipolytic Enzymes in Pathogenesis and Treatment of Neglected Diseases

Current Protein and Peptide Science ◽

10.2174/1389203716666151002115925 ◽

2015 ◽

Vol 16 (999) ◽

pp. 1-1

Author(s):

D Chakravorty ◽

S Patra

Keyword(s):

Neglected Diseases ◽

Lipolytic Enzymes

Recent Advancement in the Diagnosis and Treatment of Leprosy

Current Topics in Medicinal Chemistry ◽

10.2174/1568026618666181025100434 ◽

2018 ◽

Vol 18 (18) ◽

pp. 1550-1558

Author(s):

Muhammad Aamir ◽

Asma Sadaf ◽

Sehroon Khan ◽

Shagufta Perveen ◽

Afsar Khan

Keyword(s):

Vitamin D ◽

Drug Treatment ◽

Mycobacterium Leprae ◽

Neglected Diseases ◽

Specific Drug ◽

Genetic Studies ◽

Vitamin D Receptors ◽

Micro Rnas ◽

Leprosy Patients ◽

Skin Biopsies

Background: Many of the tropical diseases are neglected by the researchers and medicinal companies due to lack of profit and other interests. The Drugs for Neglected Diseases initiative (DNDi) is established to overcome the problems associated with these neglected diseases. According to a report published by the WHO, leprosy (Hansen's disease) is also a neglected infectious disease. Methods: A negligible amount of advancements has been made in last few decades which includes the tools of diagnosis, causes, treatment, and genetic studies of the bacterium (Mycobacterium leprae) that causes leprosy. The diagnosis of leprosy at earlier stages is important for its effective treatment. Recent studies on vitamin D and its receptors make leprosy diagnosis easier at earlier stages. Skin biopsies and qPCR are the other tools to identify the disease at its initial stages. Results: Until now a specific drug for the treatment of leprosy is not available, therefore, Multi-Drug Therapy (MDT) is used, which is hazardous to health. Besides Mycobacterium leprae, recently a new bacterium Mycobacterium lepromatosis was also identified as a cause of leprosy. During the last few years the genetic studies of Mycobacterium leprae, the role of vitamin D and vitamin D receptors (VDR), and the skin biopsies made the treatment and diagnosis of leprosy easier at early stages. The studies of micro RNAs (miRNAs) made it easy to differentiate leprosy from other diseases especially from tuberculosis. Conclusion: Leprosy can be distinguished from sarcoidosis by quantitative study of reticulin fibers present in skin. The treatment used until now for leprosy is multi-drug treatment. The complete genome identification of Mycobacterium leprae makes the research easy to develop target specified drugs for leprosy. Rifampicin, identified as a potent drug, along with other drugs in uniform multi-drug treatment, has a significant effect when given to leprosy patients at initial stages. These are effective treatments but a specific drug for leprosy is still needed to be identified. The current review highlights the use of modern methods for the identification of leprosy at its earlier stages and the effective use of drugs alone as well as in combination.

Polyamines and Related Nitrogen Compounds in the Chemotherapy of Neglected Diseases Caused by Kinetoplastids

Current Topics in Medicinal Chemistry ◽

10.2174/1568026618666180427151338 ◽

2018 ◽

Vol 18 (5) ◽

pp. 321-368 ◽

Cited By ~ 2

Author(s):

Juan A. Bisceglia ◽

Maria C. Mollo ◽

Nadia Gruber ◽

Liliana R. Orelli

Keyword(s):

Drug Targets ◽

Redox Homeostasis ◽

Cost Effective ◽

Structural Features ◽

Mammalian Host ◽

Neglected Diseases ◽

Nitrogen Compounds ◽

Chemical Structures

Neglected diseases due to the parasitic protozoa Leishmania and Trypanosoma (kinetoplastids) affect millions of people worldwide, and the lack of suitable treatments has promoted an ongoing drug discovery effort to identify novel nontoxic and cost-effective chemotherapies. Polyamines are ubiquitous small organic molecules that play key roles in kinetoplastid parasites metabolism, redox homeostasis and in the normal progression of cell cycles, which differ from those found in the mammalian host. These features make polyamines attractive in terms of antiparasitic drug development. The present work provides a comprehensive insight on the use of polyamine derivatives and related nitrogen compounds in the chemotherapy of kinetoplastid diseases. The amount of literature on this subject is considerable, and a classification considering drug targets and chemical structures were made. Polyamines, aminoalcohols and basic heterocycles designed to target the relevant parasitic enzyme trypanothione reductase are discussed in the first section, followed by compounds directed to less common targets, like parasite SOD and the aminopurine P2 transporter. Finally, the third section comprises nitrogen compounds structurally derived from antimalaric agents. References on the chemical synthesis of the selected compounds are reported together with their in vivo and/or in vitro IC50 values, and structureactivity relationships within each group are analyzed. Some favourable structural features were identified from the SAR analyses comprising protonable sites, hydrophobic groups and optimum distances between them. The importance of certain pharmacophoric groups or amino acid residues in the bioactivity of polyamine derived compounds is also discussed.