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1.
Antimicrob Agents Chemother ; 68(4): e0155923, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38497616

RESUMO

Leishmaniasis remains one of the main public health problems worldwide, with special incidence in the poorest populations. Selenium and its derivatives can be potent therapeutic options against protozoan parasites. In this work, 17 aryl selenoates were synthesized and screened against three species of Leishmania (Leishmania major, Leishmania amazonensis, and Leishmania infantum). Initial screening in promastigotes showed L. infantum species was more sensitive to selenoderivatives than the others. The lead Se-(2-selenocyanatoethyl) thiophene-2-carboselenoate (16) showed a half-maximal effective concentration of 3.07 µM and a selectivity index > 32.57 against L. infantum promastigotes. It was also the most effective of all 17 compounds, decreasing the infection ratio by 90% in L. infantum-infected macrophages with amastigotes at 10 µM. This aryl selenoate did not produce a hemolytic effect on human red blood cells at the studied doses (10-100 µM). Furthermore, the gene expression of infected murine macrophages related to cell death, the cell cycle, and the selenoprotein synthesis pathway in amastigotes was altered, while no changes were observed in their murine homologs, supporting the specificity of Compound 16 against the parasite. Therefore, this work reveals the possible benefits of selenoate derivatives for the treatment of leishmaniasis.


Assuntos
Antiprotozoários , Leishmania infantum , Leishmania mexicana , Leishmaniose , Animais , Camundongos , Humanos , Leishmaniose/tratamento farmacológico , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Expressão Gênica , Camundongos Endogâmicos BALB C
2.
Antimicrob Agents Chemother ; 68(3): e0112723, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38349159

RESUMO

The problems associated with the drugs currently used to treat leishmaniasis, including resistance, toxicity, and the high cost of some formulations, call for the urgent identification of new therapeutic agents with novel modes of action. The aggregated protein dye YAT2150 has been found to be a potent antileishmanial compound, with a half-maximal inhibitory concentration (IC50) of approximately 0.5 µM against promastigote and amastigote stages of Leishmania infantum. The encapsulation in liposomes of YAT2150 significantly improved its in vitro IC50 to 0.37 and 0.19 µM in promastigotes and amastigotes, respectively, and increased the half-maximal cytotoxic concentration in human umbilical vein endothelial cells to >50 µM. YAT2150 became strongly fluorescent when binding intracellular protein deposits in Leishmania cells. This fluorescence pattern aligns with the proposed mode of action of this drug in the malaria parasite Plasmodium falciparum, the inhibition of protein aggregation. In Leishmania major, YAT2150 rapidly reduced ATP levels, suggesting an alternative antileishmanial mechanism. To the best of our knowledge, this first-in-class compound is the only one described so far having significant activity against both Plasmodium and Leishmania, thus being a potential drug for the treatment of co-infections of both parasites.


Assuntos
Antiprotozoários , Leishmania infantum , Leishmaniose , Parasitos , Animais , Humanos , Células Endoteliais , Leishmaniose/tratamento farmacológico , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico
3.
Antimicrob Agents Chemother ; 68(1): e0050923, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38063403

RESUMO

The main challenges associated with leishmaniasis chemotherapy are drug toxicity, the possible emergence of resistant parasites, and a limited choice of therapeutic agents. Therefore, new drugs and assays to screen and detect novel active compounds against leishmaniasis are urgently needed. We thus validated Leishmania braziliensis (Lb) and Leishmania infantum (Li) that constitutively express the tandem tomato red fluorescent protein (tdTomato) as a model for large-scale screens of anti-Leishmania compounds. Confocal microscopy of Lb and Li::tdTomato revealed red fluorescence distributed throughout the entire parasite, including the flagellum, and flow cytometry confirmed that the parasites emitted intense fluorescence. We evaluated the infectivity of cloned promastigotes and amastigotes constitutively expressing tdTomato, their growth profiles in THP-1 macrophages, and susceptibility to trivalent antimony, amphotericin, and miltefosine in vitro. The phenotypes of mutant and wild-type parasites were similar, indicating that the constitutive expression of tdTomato did not interfere with the evaluated parameters. We applied our validated model to a repositioning strategy and assessed the susceptibility of the parasites to eight commercially available drugs. We also screened 32 natural plant and fungal extracts and 10 pure substances to reveal new active compounds. The infectivity and Glucantime treatment efficacy of BALB/c mice and golden hamsters infected with Lb and Li::tdTomato mutant lines, respectively, were very similar compared to animals infected with wild-type parasites. Standardizing our methodology would offer more rapid, less expensive, and easier assays to screen of compounds against L. braziliensis and L. infantum in vitro and in vivo. Our method could also enhance the discovery of active compounds for treating leishmaniasis.


Assuntos
Antiprotozoários , Leishmania braziliensis , Leishmania infantum , Leishmaniose , Cricetinae , Animais , Camundongos , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Fluorescência , Leishmaniose/tratamento farmacológico , Leishmania infantum/genética , Leishmania braziliensis/genética , Mesocricetus , Camundongos Endogâmicos BALB C
4.
Arch Microbiol ; 206(10): 408, 2024 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-39299989

RESUMO

Leishmaniasis is a complex vector-borne disease caused by intracellular protozoan parasites of the Leishmania genus. It presents a significant public health challenge in tropical and subtropical regions globally. As resistance to treatment increases, managing and controlling Leishmaniasis becomes more challenging, necessitating innovative approaches. To address this challenge, our study utilized subtractive genomics and structure-based approaches to identify common drug targets and combat antimicrobial resistance (AMR) across five Leishmania species strains. The subtractive genomics approach unraveled Glutamate Dehydrogenase (GDH) as a promising drug target for treating Leishmania infections. The investigation considered established methodologies observed in analogous studies, orthologous group, and druggability tests. Multiple sequence alignment revealed conserved sequences in GDH, while phylogenetic tree analysis provided insights into the evolutionary origin and close relationships of GDH across Leishmania species. Conserved sequences in GDH along with its function in pathogenicity provided insights into the close relationships of GDH across Leishmania species. Using a structure-based approach, our study showed the molecular interactions between GDH and three ligands-Bithionol, GW5074, and Hexachlorophene-through molecular docking and 100 ns molecular dynamics (MD) simulations. GW5074 exhibited a significant affinity for GDH, as indicated by stable RMSD values, a more compact conformation, and a higher number of hydrogen bonds than Bithionol. MMPBSA analysis confirmed the superior binding energy of the GW5074-GDH complex, emphasizing its potential as a potent ligand for drug development. This comprehensive analysis identified GW5074 as a promising candidate for inhibiting GDH activities in Leishmania species, contributing to the development of effective therapeutics against Leishmania infections.


Assuntos
Antiprotozoários , Genômica , Leishmania , Simulação de Acoplamento Molecular , Filogenia , Leishmania/efeitos dos fármacos , Leishmania/genética , Leishmania/enzimologia , Antiprotozoários/farmacologia , Simulação de Dinâmica Molecular , Glutamato Desidrogenase/genética , Glutamato Desidrogenase/metabolismo , Glutamato Desidrogenase/química , Glutamato Desidrogenase/antagonistas & inibidores , Leishmaniose/tratamento farmacológico , Leishmaniose/parasitologia , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Proteínas de Protozoários/química , Humanos , Ligantes , Alinhamento de Sequência
5.
Exp Parasitol ; 260: 108747, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38518969

RESUMO

Leishmaniasis are neglected infectious diseases caused by kinetoplastid protozoan parasites from the genus Leishmania. These sicknesses are present mainly in tropical regions and almost 1 million new cases are reported each year. The absence of vaccines, as well as the high cost, toxicity or resistance to the current drugs determines the necessity of new treatments against these pathologies. In this review, several compounds with potentialities as new antileishmanial drugs are presented. The discussion is restricted to the preclinical level and molecules are organized according to their chemical nature, source and molecular targets. In this manner, we present antimicrobial peptides, flavonoids, withanolides, 8-aminoquinolines, compounds from Leish-Box, pyrazolopyrimidines, and inhibitors of tubulin polymerization/depolymerization, topoisomerase IB, proteases, pteridine reductase, N-myristoyltransferase, as well as enzymes involved in polyamine metabolism, response against oxidative stress, signaling pathways, and sterol biosynthesis. This work is a contribution to the general knowledge of these compounds as antileishmanial agents.


Assuntos
Antiprotozoários , Leishmania , Leishmaniose , Leishmaniose/tratamento farmacológico , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Antiprotozoários/química , Leishmania/efeitos dos fármacos , Animais , Humanos , Avaliação Pré-Clínica de Medicamentos , Flavonoides/farmacologia , Flavonoides/química , Flavonoides/uso terapêutico
6.
J Enzyme Inhib Med Chem ; 39(1): 2377586, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39037009

RESUMO

Species of Leishmania and Trypanosoma genera are the causative agents of relevant parasitic diseases. Survival inside their hosts requires the existence of a potent antioxidant enzymatic machinery. Four iron superoxide dismutases have been described in trypanosomatids (FeSODA, FeSODB1, FeSODB2, and FeSODC) that hold a potential as therapeutic targets. Nonetheless, very few studies have been developed that make use of the purified enzymes. Moreover, FeSODC remains uncharacterised in Leishmania. In this work, for the first time, we describe the purification and enzymatic activity of recombinant versions of the four Leishmania FeSOD isoforms and establish an improved strategy for developing inhibitors. We propose a novel parameter [(V*cyt. c - Vcyt. c)/Vcyt. c] which, in contrast to that used in the classical cytochrome c reduction assay, correlates linearly with enzyme concentration. As a proof of concept, we determine the IC50 values of two ruthenium carbosilane metallodendrimers against these isoforms.


Assuntos
Antiprotozoários , Relação Dose-Resposta a Droga , Leishmania infantum , Testes de Sensibilidade Parasitária , Superóxido Dismutase , Leishmania infantum/enzimologia , Leishmania infantum/efeitos dos fármacos , Relação Estrutura-Atividade , Estrutura Molecular , Superóxido Dismutase/metabolismo , Superóxido Dismutase/antagonistas & inibidores , Superóxido Dismutase/química , Antiprotozoários/farmacologia , Antiprotozoários/química , Antiprotozoários/síntese química , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/síntese química , Leishmaniose/tratamento farmacológico , Leishmaniose/parasitologia
7.
Eur Arch Otorhinolaryngol ; 281(5): 2739-2742, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38453713

RESUMO

PURPOSE: To investigate the clinical manifestations, management and outcomes of Leishmania lesions in the ear-nose-throat (ENT) region, and its relationship with tumor necrosis factor (TNF)-α blocking drugs. METHODS: Single-center retrospective observational study. Patients diagnosed with cutaneous and mucosal leishmaniasis in the otorhinolaryngologic area at a tertiary referral center over a period of 8 years. RESULTS: Three cases of Leishmania lesions in the ear and two in the nose were encountered at our institution. All patients were under treatment with TNF-α blocking drugs. Diagnosis was challenging, and it was important to have a clinical suspicion in order to use accurate detection techniques. All patients received systemic treatment and achieved a complete resolution of the lesions. CONCLUSIONS: With the increasing use of biologic treatments like TNF-α blockers, this type of infection will be increasingly frequent in endemic areas and also worldwide. It is important to include leishmaniasis in the differential diagnosis of inflammatory/infectious lesions in the ENT region.


Assuntos
Leishmaniose Cutânea , Leishmaniose , Otolaringologia , Humanos , Fator de Necrose Tumoral alfa , Leishmaniose/diagnóstico , Leishmaniose/tratamento farmacológico , Pele , Estudos Retrospectivos , Leishmaniose Cutânea/terapia
8.
Vet Ophthalmol ; 27(1): 86-89, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37489904

RESUMO

Dermatological clinical signs have been seldom reported in the literature secondary to equine leishmaniasis. This case depicts the clinical signs, treatment, and outcome of a young horse with a pink, elevated lesion on the ventromedial quadrant of the cornea. A corneal cytology was performed and revealed the presence of leishmania amastigotes reaching the diagnosis of keratitis secondary to leishmania. Surgical resection was recommended but the owner declined the procedure, and the lesion was treated with a topical antimonial for 6 weeks. The lesion reduced remarkably during the first weeks of treatment. The patient had not shown recurrence of the lesion for 2 years since the treatment was started. Leishmania spp. can be responsible for ocular surface abnormalities such as keratitis. Corneal cytology is an inexpensive diagnostic method that should be considered when ocular surface abnormalities are identified in horses in endemic areas.


Assuntos
Doenças dos Cavalos , Ceratite , Leishmania , Leishmaniose , Cavalos , Animais , Ceratite/diagnóstico , Ceratite/tratamento farmacológico , Ceratite/veterinária , Córnea/patologia , Leishmaniose/diagnóstico , Leishmaniose/tratamento farmacológico , Leishmaniose/veterinária , Doenças dos Cavalos/diagnóstico , Doenças dos Cavalos/tratamento farmacológico , Doenças dos Cavalos/patologia
9.
Molecules ; 29(10)2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38792079

RESUMO

Infectious diseases caused by trypanosomatids, including African trypanosomiasis (sleeping sickness), Chagas disease, and different forms of leishmaniasis, are Neglected Tropical Diseases affecting millions of people worldwide, mainly in vulnerable territories of tropical and subtropical areas. In general, current treatments against these diseases are old-fashioned, showing adverse effects and loss of efficacy due to misuse or overuse, thus leading to the emergence of resistance. For these reasons, searching for new antitrypanosomatid drugs has become an urgent necessity, and different metabolic pathways have been studied as potential drug targets against these parasites. Considering that trypanosomatids possess a unique redox pathway based on the trypanothione molecule absent in the mammalian host, the key enzymes involved in trypanothione metabolism, trypanothione reductase and trypanothione synthetase, have been studied in detail as druggable targets. In this review, we summarize some of the recent findings on the molecules inhibiting these two essential enzymes for Trypanosoma and Leishmania viability.


Assuntos
Amida Sintases , Glutationa , NADH NADPH Oxirredutases , Trypanosoma , NADH NADPH Oxirredutases/metabolismo , NADH NADPH Oxirredutases/antagonistas & inibidores , Humanos , Amida Sintases/metabolismo , Amida Sintases/antagonistas & inibidores , Trypanosoma/efeitos dos fármacos , Trypanosoma/metabolismo , Glutationa/metabolismo , Glutationa/análogos & derivados , Animais , Espermidina/análogos & derivados , Espermidina/metabolismo , Leishmania/efeitos dos fármacos , Leishmania/metabolismo , Tripanossomicidas/farmacologia , Tripanossomicidas/uso terapêutico , Leishmaniose/tratamento farmacológico , Leishmaniose/metabolismo , Leishmaniose/parasitologia , Trypanosomatina/metabolismo , Trypanosomatina/efeitos dos fármacos , Proteínas de Protozoários/metabolismo , Proteínas de Protozoários/antagonistas & inibidores , Doença de Chagas/tratamento farmacológico , Doença de Chagas/parasitologia , Doença de Chagas/metabolismo
10.
Cutan Ocul Toxicol ; 43(3): 190-197, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39023122

RESUMO

OBJECTIVE: Miltefosine stands as the sole oral medication approved for the treatment of leishmaniasis. The appearance of severe ophthalmic toxicities induced by miltefosine in the context of leishmaniasis treatment is a matter of significant concern. The main objective of this study is to present a comprehensive summary of the ophthalmic adverse effects associated with miltefosine when used in the treatment of leishmaniasis. METHODS: A systematic search was performed on PubMed, ScienceDirect, Embase, Scopus, and Google Scholar, covering articles from inception up to June 2023, without language restrictions, to identify relevant studies documenting ocular toxicity following miltefosine treatment for leishmaniasis. RESULTS: A total of eight studies involving 31 leishmaniasis patients who developed ocular toxicities while undergoing miltefosine treatment were included in the analysis. These studies were conducted in various regions, with five originating from India, two from Bangladesh, and one from Nepal. Patients presented a spectrum of ophthalmic complications, including uveitis, keratitis, scleritis, and Mooren's ulcer. Commonly reported symptoms included pain, redness, excessive tearing, partial vision impairment, permanent blindness, light sensitivity, and the appearance of white spots on the eye. On average, patients received miltefosine treatment for a duration of 47 days before experiencing the onset of ocular problems. It is important to note that the risk of ocular toxicities increases with prolonged use of miltefosine. CONCLUSIONS: Therefore, to mitigate the potential for irreversible damage to the eyes, it is imperative that all individuals undergoing miltefosine therapy undergo regular eye examinations.


Assuntos
Antiprotozoários , Fosforilcolina , Humanos , Antiprotozoários/efeitos adversos , Antiprotozoários/uso terapêutico , Fosforilcolina/análogos & derivados , Fosforilcolina/efeitos adversos , Fosforilcolina/uso terapêutico , Leishmaniose/tratamento farmacológico , Oftalmopatias/induzido quimicamente
11.
Gastroenterol Hepatol ; 47(1): 82-92, 2024 Jan.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-37061089

RESUMO

Infection by Leishmania spp. in patients diagnosed with inflammatory bowel disease (IBD) is rare. Considered endemic in the Mediterranean basin, its manifestations are almost exclusive of patients with impaired cellular immunity. Most of the evidence is found through case reports; without guidelines for its management in patients with IBD. In this study we present three cases of Leishmania infection in patients with IBD that lead us to carry out a review of the current literature. Immunosuppressive treatment contributes to this infection, which presents atypically, with a challenging diagnosis. Initial systemic treatment with withdrawal of the immunosuppressant drug seems to be the best therapeutic strategy. Studies are needed in endemic areas to determine its incidence in IBD patients, as well as its possible association with immunosuppressive therapy. The need for serological screening prior introduction of immunosuppressive drugs could be suggested.


Assuntos
Colite Ulcerativa , Doenças Inflamatórias Intestinais , Leishmaniose , Humanos , Colite Ulcerativa/tratamento farmacológico , Doenças Inflamatórias Intestinais/complicações , Doenças Inflamatórias Intestinais/tratamento farmacológico , Doenças Inflamatórias Intestinais/epidemiologia , Imunossupressores/efeitos adversos , Leishmaniose/complicações , Leishmaniose/tratamento farmacológico
12.
PLoS Pathog ; 17(12): e1010058, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34882737

RESUMO

Proteasomes are compartmentalized, ATP-dependent, N-terminal nucleophile hydrolases that play essentials roles in intracellular protein turnover. They are present in all 3 kingdoms. Pharmacological inhibition of proteasomes is detrimental to cell viability. Proteasome inhibitor rugs revolutionize the treatment of multiple myeloma. Proteasomes in pathogenic microbes such as Mycobacterium tuberculosis (Mtb), Plasmodium falciparum (Pf), and other parasites and worms have been validated as therapeutic targets. Starting with Mtb proteasome, efforts in developing inhibitors selective for microbial proteasomes have made great progress lately. In this review, we describe the strategies and pharmacophores that have been used in developing proteasome inhibitors with potency and selectivity that spare human proteasomes and highlight the development of clinical proteasome inhibitor candidates for treatment of leishmaniasis and Chagas disease. Finally, we discuss the future challenges and therapeutical potentials of the microbial proteasome inhibitors.


Assuntos
Doença de Chagas/tratamento farmacológico , Leishmaniose/tratamento farmacológico , Complexo de Endopeptidases do Proteassoma/efeitos dos fármacos , Inibidores de Proteassoma/farmacologia , Animais , Humanos , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/metabolismo , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/metabolismo
13.
Cytokine ; 164: 156143, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36774730

RESUMO

Leishmania amazonensis can cause a wide spectrum of the clinical manifestations of leishmaniasis in humans. The development of new therapeutics is a long and expensive task; in this context, drug repositioning could be considered a strategy to identify new biological actions of known products. In the present study, ivermectin (IVE) was tested against distinct Leishmania species able to cause disease in humans. In vitro experiments showed that IVE was effective to reduce the infection degree and parasite load in Leishmania donovani- and L. amazonensis-infected macrophages that were treated with it. In addition, using the culture supernatant of treated macrophages, higher production of IFN-γ and IL-12 and lower levels of IL-4 and IL-10 were found. Then, IVE was used in a pure form or incorporated into Poloxamer 407-based polymeric micelles (IVE/M) for the treatment of L. amazonensis-infected BALB/c mice. Animals (n = 16 per group) were infected and later received saline, empty micelles, amphotericin B (AmpB), IVE, or IVE/M. They were euthanized at one (n = 8 per group) and 30 (n = 8 per group) days after treatment and, in both endpoints, immunological, parasitological, and biochemical evaluations were performed. Results showed that both IVE and IVE/M induced higher levels of IFN-γ, IL-12, GM-CSF, nitrite, and IgG2a antibodies, as well as higher IFN-γ expression evaluated by RT-qPCR in spleen cell cultures. Such animals showed low organic toxicity, as well as significant reductions in the lesion's average diameter and parasite load in their infected tissue, spleen, liver, and draining lymph node. The efficacy was maintained 30 days post-therapy, while control mice developed a polarized Th2-type response and high parasite load. In this context, IVE could be considered as a new candidate to be applied in future studies for the treatment against distinct Leishmania species.


Assuntos
Antiprotozoários , Leishmania , Leishmaniose Visceral , Leishmaniose , Humanos , Camundongos , Animais , Micelas , Ivermectina/farmacologia , Ivermectina/uso terapêutico , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Reposicionamento de Medicamentos , Leishmaniose/tratamento farmacológico , Leishmaniose/parasitologia , Interleucina-12/farmacologia , Camundongos Endogâmicos BALB C , Leishmaniose Visceral/tratamento farmacológico
14.
Bioorg Chem ; 137: 106593, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37186964

RESUMO

The current regime for leishmaniasis is associated with several adverse effects, expensive, parenteral treatment for longer periods and the emergence of drug resistance. To develop affordable and potent antileishmanial agents, a series of N-acyl and homodimeric aryl piperazines were synthesized with high purity, predicted druggable properties by in silico methods and investigated their antileishmanial activity. The in vitro biological activity of synthesized compounds against clinically validated intracellular amastigote and extracellular promastigote form of Leishmania donovani parasite showed eight compounds inhibited 50% amastigotes growth below 25 µM. The half maximal inhibitory concentration (IC50) and cytotoxicity assessment of eight active compounds, 4a, 4d and 4e demonstrated activity with an IC50 2.0 - 9.1 µM and selectivity index 10 - 42. Compound 4d (IC50 2.0 µM, SI = 42) found to be the best among them with four-folds more potent and eight-folds less toxic than the control drug miltefosine. Overall, results demonstrated that compound 4d is a promising lead candidate for further development as antileishmanial drug.


Assuntos
Antiprotozoários , Leishmania donovani , Leishmaniose , Humanos , Leishmaniose/tratamento farmacológico
15.
Bioorg Chem ; 138: 106624, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37295238

RESUMO

Nowadays, leishmaniasis is still treated with outdated drugs that present several obstacles related to their high toxicity, long duration, parenteral administration, high costs and drug resistance. Therefore, there is an urgent demand for safer and more effective novel drugs. Previous studies indicated that selenium compounds are promising derivatives for innovative therapy in leishmaniasis treatment. With this background, a new library of 20 selenocyanate and diselenide derivatives were designed based on structural features present in the leishmanicidal drug miltefosine. Compounds were initially screened against promastigotes of L. major and L. infantum and their cytotoxicity was evaluated in THP-1 cells. Compounds B8 and B9 were the most potent and less cytotoxic and were further screened for the intracellular back transformation assay. The results obtained revealed that B8 and B9 showed EC50 values of 7.7 µM and 5.7 µM, respectively, in L. major amastigotes, while they presented values of 6.0 µM and 7.4 µM, respectively, against L. infantum amastigotes. Furthermore, they exerted high selectivity (60 < SI > 70) towards bone marrow-derived macrophages. Finally, these compounds exhibited higher TryR inhibitory activity than mepacrine (IC50 7.6 and 9.2 µM, respectively), and induced nitric oxide (NO) and reactive oxygen species (ROS) production in macrophages. These results suggest that the compounds B8 and B9 could not only exert a direct leishmanicidal activity against the parasite but also present an indirect action by activating the microbicidal arsenal of the macrophage. Overall, these new generation of diselenides could constitute promising leishmanicidal drug candidates for further studies.


Assuntos
Antiprotozoários , Leishmaniose , Compostos de Selênio , Animais , Camundongos , Antiprotozoários/química , Macrófagos , Leishmaniose/tratamento farmacológico , Compostos de Selênio/farmacologia , Camundongos Endogâmicos BALB C
16.
Mol Divers ; 27(5): 2073-2092, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36306047

RESUMO

Drug therapy for leishmaniasis remains a major challenge as currently available drugs have limited efficacy, induce serious side-effects and are not accessible to everyone. Thus, the discovery of affordable drugs is urgently needed. Chalcones present a great potential as bioactive agents due to simple structure and functionalization capacity. The antileishmanial activity of different natural and synthetic chalcones have been reported. Here we report the synthesis of twenty-five novel prenylated chalcones that displayed antiparasitic activity in Leishmania mexicana. All the chalcones were evaluated at 5 µg/mL and eleven compounds exhibited a metabolic inhibition close to or exceeding 50%. Compounds 49, 30 and 55 were the three most active with IC50 values < 10 µM. These chalcones also showed the highest selectivity index (SI) values. Interestingly 49 and 55 possessing a substituent at a meta position in the B ring suggests that the substitution pattern influences antileishmanial activity. Additionally, a tridimensional model of fumarate reductase of L. mexicana was obtained by homology modeling. Docking studies suggest that prenylated chalcones could modulate fumarate reductase activity by binding with good affinity to two binding sites that are critical for the target. In conclusion, the novel prenylated chalcones could be considered as promising antileishmanial agents.


Assuntos
Antiprotozoários , Chalconas , Leishmaniose , Humanos , Chalconas/química , Succinato Desidrogenase , Éteres , Antiprotozoários/química , Leishmaniose/tratamento farmacológico , Relação Estrutura-Atividade
17.
Exp Parasitol ; 245: 108441, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36572088

RESUMO

Leishmaniasis is an enigmatic disease that has very restricted options for chemotherapy and none for prophylaxis. As a result, deriving therapeutic principles for curing the disease has been a major objective in Leishmania research for a long time. Leishmania is a protozoan parasite that lives within macrophages by subverting or switching cell signaling to the pathways that ensure its intracellular survival. Therefore, three groups of molecules aimed at blocking or eliminating the parasite, at least, in principle, include blockers of macrophage receptor- Leishmania ligand interaction, macrophage-activating small molecules, peptides and cytokines, and signaling inhibitors or activators. Macrophages also act as an antigen-presenting cell, presenting antigen to the antigen-specific T cells to induce activation and differentiation of the effector T cell subsets that either execute or suppress anti-leishmanial functions. Three groups of therapeutic principles targeting this sphere of Leishmania-macrophage interaction include antibodies that block pro-leishmanial response of T cells, ligands that activate anti-leishmanial T cells and the antigens for therapeutic vaccines. Besides these, prophylactic vaccines have been in clinical trials but none has succeeded so far. Herein, we have attempted to encompass all these principles and compose a comprehensive review to analyze the feasibility and adoptability of different therapeutics for leishmaniasis.


Assuntos
Leishmania , Leishmaniose , Vacinas , Humanos , Leishmaniose/tratamento farmacológico , Citocinas , Linfócitos T
18.
Exp Parasitol ; 251: 108555, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37247802

RESUMO

The treatment against leishmaniasis presents problems, mainly due to their toxicity of the drugs, high cost and/or by the emergence of parasite resistant strains. In this context, new therapeutics should be searched. In this study, two novel synthetic derivatives from vanillin: [4-(2-hydroxy-3-(4-octyl-1H-1,2,3-triazol-1-yl)propoxy)-3-methoxybenzaldehyde] or 3s and [4-(3-(4-decyl-1H-1,2,3-triazol-1-yl)-2-hydroxypropoxy)-3-methoxybenzaldehyde] or 3t, were evaluated regarding their antileishmanial activity against distinct parasite species able to cause cutaneous and visceral leishmaniasis. Results showed that compounds 3s and 3t were effective against Leishmania infantum, L. amazonensis and L. braziliensis promastigote and amastigote-like forms, showing selectivity index (SI) of 25.1, 18.2 and 22.9, respectively, when 3s was used against promastigotes, and of 45.2, 7.5 and 15.0, respectively, against amastigote-like stage. Using the compound 3t, SI values were 45.2, 53.0 and 80.0, respectively, against promastigotes, and of 35.9, 46.0 and 58.4, respectively, against amastigote-like forms. Amphotericin B (AmpB) showed SI values of 5.0, 7.5 and 15.0, respectively, against promastigotes, and of 3.8, 5.0 and 7.5, respectively, against amastigote-like stage. The treatment of infected macrophages and inhibition of the infection upon pre-incubation with the molecules showed that they were effective in reducing the infection degree and inhibiting the infection in pre-incubated parasites, respectively, as compared to data obtained using AmpB. The mechanism of action of 3s and 3t was evaluated in L. infantum, revealing that both 3s and 3t altered the parasite mitochondrial membrane potential leading to reactive oxygen species production, increase in lipid corps and changes in the cell cycle, causing the parasite' death. A preliminary assay using the cell culture supernatant from treated and infected macrophages showed that 3s and 3t induced higher IL-12 and lower IL-10 values; suggesting the development of an in vitro Th1-type response in the treated cells. In this context, data indicated that 3s and 3t could be considered therapeutic agents to be tested in future studies against leishmaniasis.


Assuntos
Antiprotozoários , Leishmania infantum , Leishmaniose Visceral , Leishmaniose , Animais , Camundongos , Leishmaniose Visceral/tratamento farmacológico , Leishmaniose Visceral/parasitologia , Antiprotozoários/toxicidade , Antiprotozoários/uso terapêutico , Anfotericina B/toxicidade , Anfotericina B/uso terapêutico , Leishmaniose/tratamento farmacológico , Camundongos Endogâmicos BALB C
19.
Exp Parasitol ; 246: 108462, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36642298

RESUMO

Tegumentary leishmaniasis encompasses a spectrum of clinical manifestations caused by the parasitic protozoa of the genus Leishmania. In Brazil, there are at least seven Leishmania species that are endemic and responsible for this set of clinical manifestations of the disease. Current treatment is limited to a restricted number of drugs that in general have several drawbacks including parenteral use, toxicity, and severe side effects. Amphotericin B is considered a second-line drug for tegumentary leishmaniasis in Brazil, while miltefosine was recently approved for clinical use in the treatment of this disease. In this study, we investigated the in vitro susceptibility of Leishmania strains representative of the species endemic to Brazil, as well as a panel of thirteen clinical isolates of tegumentary leishmaniasis, to both amphotericin B and miltefosine. A moderate variation in the susceptibility to both drugs was found, where the EC50 values varied from 11.43 to 52.67 µM for miltefosine and from 12.89 to 62.36 nM for amphotericin B in promastigotes, while for the intracellular amastigotes, values ranged from 1.08 to 9.60 µM and from 1.69 to 22.71 nM for miltefosine and amphotericin B respectively. Furthermore, the clinical isolates and strains of the subgenus Viannia were evaluated for the presence of Leishmania RNA virus 1 (LRV1), as this is an important factor associated with disease severity and treatment outcome. These findings provide a preclinical dataset of the activity of these drugs against the causative species of tegumentary leishmaniasis in Brazil.


Assuntos
Antiprotozoários , Leishmania , Leishmaniose Cutânea , Leishmaniose , Humanos , Anfotericina B/farmacologia , Anfotericina B/uso terapêutico , Brasil/epidemiologia , Leishmaniose/tratamento farmacológico , Fosforilcolina/farmacologia , Fosforilcolina/uso terapêutico , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Leishmaniose Cutânea/tratamento farmacológico , Leishmaniose Cutânea/epidemiologia , Leishmaniose Cutânea/parasitologia
20.
Exp Parasitol ; 251: 108554, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37268108

RESUMO

Although there are available treatments for cutaneous leishmaniasis (CL), the drugs used are far from ideal, toxic, and costly, in addition to the challenge faced by the development of resistance. Plants have been used as a source of natural compounds with antileishmanial action. However, few have reached the market and become phytomedicines with registration in regulatory agencies. Difficulties related to the extraction, purification, chemical identification, efficacy, safety, and production in sufficient quantity for clinical studies, hinder the emergence of new effective phytomedicines against leishmaniasis. Despite the difficulties reported, the major research centers in the world see that natural products are a trend concerning the treatment of leishmaniasis. The present work consists of a literature review of articles with in vivo studies, covering the period from January 2011 to December 2022, providing an overview of promising natural products for CL treatment. The papers show encouraging antileishmanial action of natural compounds with reduced parasite load and lesion size in animal models, suggesting new strategies for the treatment of the disease. The results reported in this review show advances in using natural products as safe and effective formulations, which can stimulate clinical studies to establish clinical therapy. In conclusion, the information in this review article serves as a preliminary basis for establishing a therapeutic protocol for future clinical trials that can validate the safety and efficacy of natural compounds, providing the development of affordable and safe phytomedicines for the treatment of CL.


Assuntos
Antiprotozoários , Produtos Biológicos , Leishmania , Leishmaniose Cutânea , Leishmaniose , Animais , Produtos Biológicos/farmacologia , Produtos Biológicos/uso terapêutico , Leishmaniose Cutânea/tratamento farmacológico , Leishmaniose/tratamento farmacológico , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Antiprotozoários/química , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Extratos Vegetais/química
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