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/metabolismoRESUMO
Trypanosomatids are an important group of parasites that predominate in tropical and subtropical areas of the planet, which cause diseases that are classified as forgotten and neglected by the world health organization. In this group of parasites, we find Trypanosoma cruzi, Trypanosoma brucei, Trypanosoma brucei rhodesiense and Leishmania spp, for which there is no vaccine available, and its control has focused mainly on pharmacological treatment. Due to the poverty situation where these diseases are found and the biological complexity of these parasites, there are multiple variables to control, including the diversity of species, the complexity of their life cycles, drug resistance, cytotoxicity, the limited use in pregnant women, the high costs of treatment and the little-known pharmacological mechanisms of action, among others. It is therefore necessary to find new strategies and approaches for the treatment of these parasitic diseases. Among these new approaches is the rational search for new targets based on the allosteric inhibition of protein kinases, which have been little studied in trypanosomatids. Among these kinases, we find Glycogen Synthase Kinase-3 (GSK-3), a kinase of great pharmacological interest, which is under intense basic and clinical research by pharmaceutical companies for the treatment of cancer. This kinase, highly studied in the PI3K/AKT/mTOR pathway signaling in humans, has an orthologous gene in these parasites (GSK-3 s), which has proven to be essential for them in response to different challenges; Therefore, it is notable to increase research in this kinase in order to achieve a broad structural and functional characterization in the different species of trypanosomatids.
Assuntos
Quinase 3 da Glicogênio Sintase , Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Humanos , Animais , Trypanosomatina/enzimologia , Trypanosomatina/efeitos dos fármacos , Trypanosomatina/genéticaRESUMO
Cyanotriazole compounds "poison" topoisomerase II of pathogenic trypanosomatids.
Assuntos
Antiparasitários , Inibidores da Topoisomerase II , Triazóis , Trypanosomatina , Antiparasitários/classificação , Antiparasitários/farmacologia , DNA Topoisomerases Tipo II , Triazóis/classificação , Triazóis/farmacologia , Inibidores da Topoisomerase II/classificação , Inibidores da Topoisomerase II/farmacologia , Trypanosomatina/efeitos dos fármacos , Animais , HumanosRESUMO
The objective of this study was to investigate the seasonal variance of the content and chemical composition of the essential oil from Lantana camara accessions at two harvest times, and to analyze the trypanocidal activity on Phytomonas serpens. Essential oil content ranged from 0.13 to 0.29% in the rainy season and from 0.13 to 0.33% in the dry season. The compounds E-caryophyllene, α-humulene, α-curcumene and germacrene D defined the formation of four chemical clusters in the rainy and dry seasons, classified as: Cluster 1 (E-caryophyllene + germacrene D); Cluster 2 (germacrene D + E-caryophyllene); Cluster 3 (α-humulene + E-caryophyllene); and Cluster 4 (α-curcumene + E-caryophyllene). All L. camara essential oils, representing the four chemical clusters, inhibited P. serpenswith low concentrations, considering the following IC50 values: 18.34±6.60 µg/mL (LAC-018, Cluster 1); 9.14±3.87 µg/mL (LAC-027, Cluster 2); 14.56±3.40 µg/mL (LAC-037, Cluster 3); and 14.97±2.68 µg/mL (LAC-019, Cluster 4).
El objetivo de este estudio fue investigar la variación estacional del contenido y la composición química del aceite esencial de accesiones de Lantana camara en dos tiempos de cosecha y analizar la actividad tripanocida en Phytomonas serpens. El contenido de aceite esencial osciló entre 0,13% y 0,29% en la temporada de lluvias y entre 0,13% y 0,33% en la temporada seca. Los compuestos E-cariofileno, α-humuleno, α-curcumeno y germacreno D definieron la formación de cuatro grupos químicos en las estaciones lluviosa y seca, clasificados como: Grupo 1 (E-cariofileno + germacreno D); Grupo 2 (germacreno D + E-cariofileno); Grupo 3 (α-humuleno + E-cariofileno); y Grupo 4 (α-curcumeno + E-cariofileno). Todos los aceites esenciales de L. camara, que representan los cuatro grupos químicos, inhibieron P. serpens con bajas concentraciones, considerando los siguientes valores de CI50:18,34 ± 6,60 µg / mL (LAC-018, grupo 1); 9,14 ± 3,87 µg / ml (LAC-027, grupo 2); 14,56 ± 3,40 µg / ml (LAC-037, grupo 3); y 14,97 ± 2,68 µg / ml (LAC-019, grupo 4).
Assuntos
Estações do Ano , Óleos Voláteis/química , Verbenaceae/química , Antiprotozoários/química , Terpenos/análise , Óleos Voláteis/farmacologia , Trypanosomatina/efeitos dos fármacos , Estação Seca , Estação Chuvosa , Antiprotozoários/farmacologiaRESUMO
Trypanosomatidae family belongs to the Kinetoplastida order, which consists of obligatory parasites that affect plants and all classes of vertebrates, especially humans and insects. Among the heteroxenic parasites, Leishmania spp., Trypanosoma cruzi, and T. brucei are protozoa of most significant interest for medicinal chemistry, being etiological agents of Leishmaniasis, Chagas, and Sleep Sickness diseases, respectively. Currently, inefficient pharmacotherapy, especially in chronic phases and low selectivity towards parasite/host cells, justifies the need to discover new drugs to treat them effectively. Among other targets, the sterol 14α-demethylase (CYP51), an enzyme responsible for ergosterol's biosynthesis in Trypanosomatidae parasites, has received more attention in the development of new bioactive compounds. In this context, antifungal ravuconazole proved to be the most promising drug among this class against T. cruzi, being used in combined therapy with Bnz in clinic trials. Non-antifungal inhibitors, such as VFV and VNF, have shown promising results against T. cruzi and T.brucei, respectively, being tested in Bnz-combined therapies. Among the experimental studies involving azoles, compound (15) was found to be the most promising derivative, displaying an IC50 value of 0.002 µM against amastigotes from T. cruzi, in addition to being non-toxic and highly selective towards TcCYP51 (< 25 nM). Interestingly, imidazole analog (16) was active against infectious forms of these three parasites, demonstrating Ki values of 0.17, 0.02, and 0.36 nM for CYP51 from T. cruzi, T. brucei, and L. infantum. Finally, this review will address promising inhibitors targeting sterol 14α-demethylase (CYP51) from Trypanosomatidae parasites, highlighting SAR studies, interactions with this target, and recent contributions and advances in the field, as well.
Assuntos
Inibidores de 14-alfa Desmetilase/farmacologia , Antiparasitários/farmacologia , Esterol 14-Desmetilase/metabolismo , Trypanosomatina/efeitos dos fármacos , Trypanosomatina/enzimologia , Inibidores de 14-alfa Desmetilase/química , Animais , Antiparasitários/química , Química Farmacêutica , Infecções por Euglenozoa/tratamento farmacológico , Infecções por Euglenozoa/parasitologia , HumanosRESUMO
Eight essential oils (EOs) from selected medicinal plants have been tested for their activity against Phytomonas davidi, a plant trypanosomal parasite. In the present research, the EOs have been tested on promastigote forms of P. davidi ATCC® 30287™ strain, along with their major components, both separately and in binary combinations, using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay. The EOs with the highest antipromastigote activity were from Origanum virens and Salvia lavandulifolia. Thymol and ß-pinene were the most active pure compounds. The study of the activity of the pure compounds in combination indicated the existence of antagonistic and synergistic effects depending on the concentration tested. In general, the combinations at low concentrations favored the activity.
Assuntos
Antiprotozoários/farmacologia , Monoterpenos Bicíclicos/farmacologia , Óleos Voláteis/farmacologia , Plantas Medicinais/química , Timol/farmacologia , Trypanosomatina/efeitos dos fármacos , Antiprotozoários/química , Antiprotozoários/isolamento & purificação , Monoterpenos Bicíclicos/química , Monoterpenos Bicíclicos/isolamento & purificação , Óleos Voláteis/química , Óleos Voláteis/isolamento & purificação , Origanum/química , Testes de Sensibilidade Parasitária , Salvia/química , Timol/química , Timol/isolamento & purificaçãoRESUMO
Neglected Tropical Diseases (NTD) represent a serious threat to humans, especially for those living in poor or developing countries. Almost one-sixth of the world population is at risk of suffering from these diseases and many thousands die because of NTDs, to which we should add the sanitary, labor and social issues that hinder the economic development of these countries. Protozoan-borne diseases are responsible for more than one million deaths every year. Visceral leishmaniasis, Chagas disease or sleeping sickness are among the most lethal NTDs. Despite not being considered an NTD by the World Health Organization (WHO), malaria must be added to this sinister group. Malaria, caused by the apicomplexan parasite Plasmodium falciparum, is responsible for thousands of deaths each year. The treatment of this disease has been losing effectiveness year after year. Many of the medicines currently in use are obsolete due to their gradual loss of efficacy, their intrinsic toxicity and the emergence of drug resistance or a lack of adherence to treatment. Therefore, there is an urgent and global need for new drugs. Despite this, the scant interest shown by most of the stakeholders involved in the pharmaceutical industry makes our present therapeutic arsenal scarce, and until recently, the search for new drugs has not been seriously addressed. The sources of new drugs for these and other pathologies include natural products, synthetic molecules or repurposing drugs. The most frequent sources of natural products are microorganisms, e.g., bacteria, fungi, yeasts, algae and plants, which are able to synthesize many drugs that are currently in use (e.g. antimicrobials, antitumor, immunosuppressants, etc.). The marine environment is another well-established source of bioactive natural products, with recent applications against parasites, bacteria and other pathogens which affect humans and animals. Drug discovery techniques have rapidly advanced since the beginning of the millennium. The combination of novel techniques that include the genetic modification of pathogens, bioimaging and robotics has given rise to the standardization of High-Performance Screening platforms in the discovery of drugs. These advancements have accelerated the discovery of new chemical entities with antiparasitic effects. This review presents critical updates regarding the use of High-Throughput Screening (HTS) in the discovery of drugs for NTDs transmitted by protozoa, including malaria, and its application in the discovery of new drugs of marine origin.
Assuntos
Antiprotozoários/farmacologia , Organismos Aquáticos/química , Produtos Biológicos/farmacologia , Infecções por Euglenozoa/tratamento farmacológico , Malária Falciparum/tratamento farmacológico , Doenças Negligenciadas/tratamento farmacológico , Animais , Antiprotozoários/uso terapêutico , Produtos Biológicos/uso terapêutico , Descoberta de Drogas , Resistência a Medicamentos , Infecções por Euglenozoa/parasitologia , Ensaios de Triagem em Larga Escala , Humanos , Malária Falciparum/parasitologia , Doenças Negligenciadas/parasitologia , Plasmodium falciparum/efeitos dos fármacos , Plasmodium malariae/efeitos dos fármacos , Plasmodium malariae/patogenicidade , Trypanosomatina/efeitos dos fármacosRESUMO
BACKGROUND: Protozoa are distantly related to vertebrates but present some features of higher eukaryotes, making them good model systems for studying the evolution of basic processes such as the cell cycle. Herpetomonas samuelpessoai is a trypanosomatid parasite isolated from the hemipteran insect Zelus leucogrammus. Lysophosphatidylcholine (LPC) is implicated in the transmission and establishment of Chagas disease, whose etiological agent is Trypanosoma cruzi. LPC is synthesized by T. cruzi and its vectors, the hemipteran Rhodnius prolixus and Triatoma infestans. Platelet-activating factor (PAF), a phospholipid with potent and diverse physiological and pathophysiological actions, is a powerful inducer of cell differentiation in Herpetomonas muscarum muscarum and T. cruzi. The enzyme phospholipase A2 (PLA2) catalyzes the hydrolysis of the 2-ester bond of 3-sn-phosphoglyceride, transforming phosphatidylcholine (PC) into LPC. METHODS: In this study, we evaluated cellular differentiation, PLA2 activity and protein kinase CK2 activity of H. samuelpessoai in the absence and in the presence of LPC and PAF. RESULTS: We demonstrate that both PC and LPC promoted a twofold increase in the cellular differentiation of H. samuelpessoai, through CK2, with a concomitant inhibition of its cell growth. Intrinsic PLA2 most likely directs this process by converting PC into LPC. CONCLUSIONS: Our results suggest that the actions of LPC on H. samuelpessoai occur upon binding to a putative PAF receptor and that the protein kinase CK2 plays a major role in this process. Cartoon depicting a model for the synthesis and functions of LPC in Herpetomonas samuelpessoai, based upon our results regarding the role of LPC on the cell biology of Trypanosoma cruzi [28-32]. N nucleus, k kinetoplast, PC phosphatidylcholine, LPC lysophosphatidylcholine, PLA2 phospholipase A2, PAFR putative PAF receptor in trypanosomatids [65], CK2 protein kinase CK2 [16].
Assuntos
Caseína Quinase II/metabolismo , Diferenciação Celular , Lisofosfatidilcolinas/metabolismo , Redes e Vias Metabólicas , Trypanosomatina/fisiologia , Animais , Diclororribofuranosilbenzimidazol/farmacologia , Inibidores Enzimáticos/farmacologia , Hemípteros/parasitologia , Fosfolipases A2/metabolismo , Triazóis/farmacologia , Trypanosomatina/efeitos dos fármacosRESUMO
(+)-N6-Hydroxyagelasine D, the enantiomer of the proposed structure of (-)-ageloxime D, as well as N6-hydroxyagelasine analogs were synthesized by selective N-7 alkylation of N6-[tert-butyl(dimethyl)silyloxy]-9-methyl-9H-purin-6-amine in order to install the terpenoid side chain, followed by fluoride mediated removal of the TBDMS-protecting group. N6-Hydroxyagelasine D and the analog carrying a geranylgeranyl side chain displayed profound antimicrobial activities against several pathogenic bacteria and protozoa and inhibited bacterial biofilm formation. However these compounds were also toxic towards mammalian fibroblast cells (MRC-5). The spectral data of N6-hydroxyagelasine D did not match those reported for ageloxime D before. Hence, a revised structure of ageloxime D was proposed. Basic hydrolysis of agelasine D gave (+)-N-[4-amino-6-(methylamino)pyrimidin-5-yl]-N-copalylformamide, a compound with spectral data in full agreement with those reported for (-)-ageloxime D.
Assuntos
Antibacterianos/farmacologia , Diterpenos/farmacologia , Pirimidinas/farmacologia , Antibacterianos/síntese química , Antibacterianos/toxicidade , Biofilmes/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Linhagem Celular , Diterpenos/síntese química , Diterpenos/toxicidade , Escherichia coli/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis/efeitos dos fármacos , Pirimidinas/síntese química , Pirimidinas/toxicidade , Staphylococcus aureus/efeitos dos fármacos , Trypanosomatina/efeitos dos fármacosRESUMO
Tritryps diseases are devastating parasitic neglected infections caused by Leishmania spp., Trypanosoma cruzi and Trypanosoma brucei subspecies. Together, these parasites affect more than 30 million people worldwide and cause high mortality and morbidity. Leishmaniasis comprises a complex group of diseases with clinical manifestation ranging from cutaneous lesions to systemic visceral damage. Antimonials, the first-choice drugs used to treat leishmaniasis, lead to high toxicity and carry significant contraindications limiting its use. Drug-resistant parasite strains are also a matter for increasing concern, especially in areas with very limited resources. The current scenario calls for novel and/or improvement of existing therapeutics as key research priorities in the field. Although several studies have shown advances in drug discovery towards leishmaniasis in recent years, key knowledge gaps in drug discovery pipelines still need to be addressed. In this review we discuss not only scientific and non-scientific bottlenecks in drug development, but also the central role of public-private partnerships for a successful campaign for novel treatment options against this devastating disease.
Assuntos
Descoberta de Drogas/métodos , Leishmania/efeitos dos fármacos , Leishmaniose/tratamento farmacológico , Animais , Antiprotozoários/efeitos adversos , Antiprotozoários/uso terapêutico , Antiprotozoários/toxicidade , Doença de Chagas/tratamento farmacológico , Sistemas de Liberação de Medicamentos/métodos , Sistemas de Liberação de Medicamentos/estatística & dados numéricos , Descoberta de Drogas/legislação & jurisprudência , Descoberta de Drogas/estatística & dados numéricos , Descoberta de Drogas/tendências , Humanos , Doenças Negligenciadas/tratamento farmacológico , Doenças Negligenciadas/parasitologia , Parcerias Público-Privadas , Trypanosoma brucei brucei/efeitos dos fármacos , Trypanosoma cruzi/efeitos dos fármacos , Trypanosomatina/efeitos dos fármacosRESUMO
The purpose of this review is to survey the antiparasitic plants of the Asteraceae family and their applicability in the treatment of parasites. This review is divided into three major parts: (a) literature on traditional uses of Asteraceae plants for the treatment of parasites; (b) description of the major classes of chemical compounds from Asteraceae and their antiparasitic effects; and (c) antiparasitic activity with special reference to flavonoids and terpenoids. This review provides detailed information on the reported Asteraceae plant extracts found throughout the world and on isolated secondary metabolites that can inhibit protozoan parasites such as Plasmodium, Trypanosoma, Leishmania, and intestinal worms. Additionally, special attention is given to the Asteraceae plants of Odisha, used by the tribes of the area as antiparasitics. These plants are compared to the same plants used traditionally in other regions. Finally, we provide information on which plants identified in Odisha, India and related compounds show promise for the development of new drugs against parasitic diseases. For most of the plants discussed in this review, the active compounds still need to be isolated and tested further.
Assuntos
Antiparasitários/farmacologia , Asteraceae/química , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Plasmodium/efeitos dos fármacos , Trypanosomatina/efeitos dos fármacos , Animais , Antiparasitários/química , Helmintos/efeitos dos fármacos , Humanos , Índia , Leishmania/efeitos dos fármacos , Fitoterapia , Grupos Populacionais , Trypanosoma/efeitos dos fármacosRESUMO
Nanomaterials are currently considered for many biological, biomedical and environmental purposes, due to their outstanding physical and chemical properties. The synthesis of gold nanoparticles (Au NPs) is of high interest for research in parasitology and entomology, since these nanomaterials showed promising applications, ranging from detection techniques to drug development, against a rather wide range of parasites of public health relevance, as well as on insect vectors. Here, I reviewed current knowledge about the bioactivity of Au NPs on selected insect species of public health relevance, including major mosquito vectors, such as Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus. The toxicity of Au NPs against helminths was reviewed, covering Schistosoma mansoni trematodes as well as Raillietina cestodes. Furthermore, I summarized the information available on the antiparasitic role of Au NPs in the fight against malaria, leishmaniosis, toxoplasmosis, trypanosomiasis, cryptosporidiosis, and microsporidian parasites affecting human and animals health. Besides, I examined the employ of Au NPs as biomarkers, tools for diagnostics and adjuvants for the induction of transmission blocking immunity in malaria vaccine research. In the final section, major challenges and future outlooks for further research are discussed, with special reference to the pressing need of further knowledge about the effect of Au NPs on other arthropod vectors, such as ticks, tsetse flies, tabanids, sandflies and blackflies, and related ecotoxicology assays.
Assuntos
Ouro/química , Ouro/imunologia , Insetos Vetores/efeitos dos fármacos , Nanopartículas Metálicas/química , Parasitos/efeitos dos fármacos , Aedes/efeitos dos fármacos , Animais , Anopheles/efeitos dos fármacos , Biomarcadores , Cryptosporidium/efeitos dos fármacos , Culex/efeitos dos fármacos , Técnicas e Procedimentos Diagnósticos , Helmintos/efeitos dos fármacos , Humanos , Inseticidas/farmacologia , Larva/efeitos dos fármacos , Vacinas Antimaláricas/química , Vacinas Antimaláricas/imunologia , Mosquitos Vetores/efeitos dos fármacos , Trypanosomatina/efeitos dos fármacosRESUMO
The species Phytomonas serpens is known to express some molecules displaying similarity to those described in trypanosomatids pathogenic to humans, such as peptidases from Trypanosoma cruzi (cruzipain) and Leishmania spp. (gp63). In this work, a population of P. serpens resistant to the calpain inhibitor MDL28170 at 70 µ m (MDLR population) was selected by culturing promastigotes in increasing concentrations of the drug. The only relevant ultrastructural difference between wild-type (WT) and MDLR promastigotes was the presence of microvesicles within the flagellar pocket of the latter. MDLR population also showed an increased reactivity to anti-cruzipain antibody as well as a higher papain-like proteolytic activity, while the expression of calpain-like molecules cross-reactive to anti-Dm-calpain (from Drosophila melanogaster) antibody and calcium-dependent cysteine peptidase activity were decreased. Gp63-like molecules also presented a diminished expression in MDLR population, which is probably correlated to the reduction in the parasite adhesion to the salivary glands of the insect vector Oncopeltus fasciatus. A lower accumulation of Rhodamine 123 was detected in MDLR cells when compared with the WT population, a phenotype that was reversed when MDLR cells were treated with cyclosporin A and verapamil. Collectively, our results may help in the understanding of the roles of calpain inhibitors in trypanosomatids.
Assuntos
Inibidores de Cisteína Proteinase/farmacologia , Dipeptídeos/farmacologia , Proteínas de Membrana Transportadoras/efeitos dos fármacos , Peptídeo Hidrolases/efeitos dos fármacos , Trypanosomatina/efeitos dos fármacos , Calpaína/antagonistas & inibidores , Calpaína/química , Calpaína/efeitos dos fármacos , Calpaína/genética , Cisteína Endopeptidases/imunologia , Resistência a Medicamentos , Glicoproteínas/farmacologia , Leishmania/química , Leishmania/fisiologia , Proteínas de Membrana Transportadoras/genética , Peptídeo Hidrolases/genética , Proteínas de Protozoários/imunologia , Trypanosoma cruzi/química , Trypanosoma cruzi/fisiologia , Trypanosomatina/genéticaRESUMO
The trypanosomatid-induced diseases are considered as neglected, because the countries where they kill people are not important markets for western big pharmaceutical companies. However, recently some effort has been made to translate the use of already known drugs to neglected infectious disease. Although many metals are essential to life, many disorders affecting metal homeostasis and bioavailability are responsible for several human diseases. Metals can be toxic even at very low concentrations and semimetals are classified as toxic and dangerous for the environment. However, metal- and metalloid-based therapeutic drugs have existed for centuries. Some of them, as antimony and arsenic compounds, are still the first line drugs used for the treatment of leishmaniasis and trypanosomiases in developing countries. Other metal complexes (as those of Ag, Pt, Pd and Au), already present in the market for cancer therapies or to cure bacterial infection or for anti-inflammatory treatments, have been proposed also against the vector-borne infections caused by trypanosomatids. The use of novel approaches based on nanotechnologies, allowing selective targeting, may represent a promising strategy to decrease the toxicity of these drugs.
Assuntos
Complexos de Coordenação/farmacologia , Leishmaniose/tratamento farmacológico , Metais/química , Tripanossomicidas/farmacologia , Trypanosomatina/efeitos dos fármacos , Tripanossomíase/tratamento farmacológico , Animais , Complexos de Coordenação/química , Interações Hospedeiro-Parasita/efeitos dos fármacos , Humanos , Leishmaniose/parasitologia , Resultado do Tratamento , Tripanossomicidas/química , Trypanosomatina/fisiologia , Tripanossomíase/parasitologiaRESUMO
Reactive oxygen species (ROS) are toxic molecules involved in several biological processes such as cellular signaling, proliferation, differentiation and cell death. Adaptations to oxidative environments are crucial for the success of the colonization of insects by protozoa. Strigomonas culicis is a monoxenic trypanosomatid found in the midgut of mosquitoes and presenting a life cycle restricted to the epimastigote form. Among S. culicis peculiarities, there is an endosymbiotic bacterium in the cytoplasm, which completes essential biosynthetic routes of the host cell and may represent an intermediary evolutive step in organelle origin, thus constituting an interesting model for evolutive researches. In this work, we induced ROS resistance in wild type S. culicis epimastigotes by the incubation with increasing concentrations of hydrogen peroxide (H2O2), and compared the oxidative and energetic metabolisms among wild type, wild type-H2O2 resistant and aposymbiotic strains. Resistant protozoa were less sensitive to the oxidative challenge and more dependent on oxidative phosphorylation, which was demonstrated by higher oxygen consumption and mitochondrial membrane potential, increased activity of complexes II-III and IV, increased complex II gene expression and higher ATP production. Furthermore, the wild type-H2O2 resistant strain produced reduced ROS levels and showed lower lipid peroxidation, as well as an increase in gene expression of antioxidant enzymes and thiol-dependent peroxidase activity. On the other hand, the aposymbiotic strain showed impaired mitochondrial function, higher H2O2 production and deficient antioxidant response. The induction of H2O2 resistance also led to a remarkable increase in Aedes aegypti midgut binding in vitro and colonization in vivo, indicating that both the pro-oxidant environment in the mosquito gut and the oxidative stress susceptibility regulate S. culicis population in invertebrates.
Assuntos
Aedes/parasitologia , Complexo de Proteínas da Cadeia de Transporte de Elétrons/genética , Metabolismo Energético/genética , Interações Hospedeiro-Parasita , Peróxido de Hidrogênio/farmacologia , Proteínas de Protozoários/genética , Trypanosomatina/metabolismo , Trifosfato de Adenosina/biossíntese , Animais , Antioxidantes/metabolismo , Betaproteobacteria/metabolismo , Evolução Biológica , Resistência a Medicamentos , Complexo de Proteínas da Cadeia de Transporte de Elétrons/metabolismo , Trato Gastrointestinal/parasitologia , Regulação da Expressão Gênica , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Oxirredução , Estresse Oxidativo , Proteínas de Protozoários/metabolismo , Transdução de Sinais , Simbiose/fisiologia , Trypanosomatina/efeitos dos fármacos , Trypanosomatina/genética , Trypanosomatina/microbiologiaRESUMO
Chalcones display a broad spectrum of pharmacological activities. Herein, a series of 2'-hydroxy methoxylated chalcones was synthesized and evaluated towards Trypanosoma brucei, Trypanosoma cruzi and Leishmania infantum. Among the synthesized library, compounds 1, 3, 4, 7 and 8 were the most potent and selective anti-T. brucei compounds (EC50 = 1.3-4.2 µM, selectivity index >10-fold). Compound 4 showed the best early-tox and antiparasitic profile. The pharmacokinetic studies of compound 4 in BALB/c mice using hydroxypropil-ß-cyclodextrins formulation showed a 7.5 times increase in oral bioavailability.
Assuntos
Antiparasitários/química , Antiparasitários/farmacologia , Chalconas/química , Chalconas/farmacologia , Animais , Antiparasitários/farmacocinética , Antiparasitários/toxicidade , Linhagem Celular Tumoral , Chalconas/farmacocinética , Chalconas/toxicidade , Ciclodextrinas/química , Portadores de Fármacos/química , Camundongos , Solubilidade , Trypanosomatina/efeitos dos fármacosRESUMO
In Liu et al., the authors present a 2.5-Å structure of the Trypanosoma cruzi 60S ribosomal subunit and propose a model for the stepwise assembly of the large-subunit ribosomal RNA (rRNA). Based on this study, we discuss how the unique features of trypanosomatid ribosome assembly offer potential drug targets.
Assuntos
Descoberta de Drogas , Ribossomos/química , Ribossomos/metabolismo , Trypanosomatina/fisiologia , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Sistemas de Liberação de Medicamentos , Multimerização Proteica/efeitos dos fármacos , Trypanosomatina/efeitos dos fármacos , Tripanossomíase/tratamento farmacológicoRESUMO
BACKGROUND: Bacterial endosymbionts are found across the eukaryotic kingdom and profoundly impacted eukaryote evolution. In many endosymbiotic associations with vertically inherited symbionts, highly complementary metabolic functions encoded by host and endosymbiont genomes indicate integration of metabolic processes between the partner organisms. While endosymbionts were initially expected to exchange only metabolites with their hosts, recent evidence has demonstrated that also host-encoded proteins can be targeted to the bacterial symbionts in various endosymbiotic systems. These proteins seem to participate in regulating symbiont growth and physiology. However, mechanisms required for protein targeting and the specific endosymbiont targets of these trafficked proteins are currently unexplored owing to a lack of molecular tools that enable functional studies of endosymbiotic systems. RESULTS: Here we show that the trypanosomatid Angomonas deanei, which harbors a ß-proteobacterial endosymbiont, is readily amenable to genetic manipulation. Its rapid growth, availability of full genome and transcriptome sequences, ease of transfection, and high frequency of homologous recombination have allowed us to stably integrate transgenes into the A. deanei nuclear genome, efficiently generate null mutants, and elucidate protein localization by heterologous expression of a fluorescent protein fused to various putative targeting signals. Combining these novel tools with proteomic analysis was key for demonstrating the routing of a host-encoded protein to the endosymbiont, suggesting the existence of a specific endosymbiont-sorting machinery in A. deanei. CONCLUSIONS: After previous reports from plants, insects, and a cercozoan amoeba we found here that also in A. deanei, i.e. a member of a fourth eukaryotic supergroup, host-encoded proteins can be routed to the bacterial endosymbiont. This finding adds further evidence to our view that the targeting of host proteins is a general strategy of eukaryotes to gain control over and interact with a bacterial endosymbiont. The molecular resources reported here establish A. deanei as a time and cost efficient reference system that allows for a rigorous dissection of host-symbiont interactions that have been, and are still being shaped over evolutionary time. We expect this system to greatly enhance our understanding of the biology of endosymbiosis.
Assuntos
Genômica/métodos , Simbiose , Trypanosomatina/genética , Trypanosomatina/microbiologia , Animais , Sequência de Bases , Betaproteobacteria/efeitos dos fármacos , Betaproteobacteria/metabolismo , Cinamatos/farmacologia , Vetores Genéticos/metabolismo , Genoma de Protozoário , Gentamicinas/farmacologia , Proteínas de Fluorescência Verde/metabolismo , Recombinação Homóloga/efeitos dos fármacos , Recombinação Homóloga/genética , Higromicina B/análogos & derivados , Higromicina B/farmacologia , Mutagênese Insercional/genética , Transporte Proteico/efeitos dos fármacos , Proteínas de Protozoários/metabolismo , Reprodutibilidade dos Testes , Análise de Sequência de DNA , Frações Subcelulares/efeitos dos fármacos , Frações Subcelulares/metabolismo , Simbiose/efeitos dos fármacos , Simbiose/genética , Transcriptoma/efeitos dos fármacos , Transcriptoma/genética , Trypanosomatina/efeitos dos fármacosRESUMO
In this review, we summarize our knowledge about mitochondrial potassium channels, with a special focus on unanswered questions in this field. The following potassium channels have been well described in the inner mitochondrial membrane: ATP-regulated potassium channel, Ca(2+)-activated potassium channel, the voltage-gated Kv1.3 potassium channel, and the two-pore domain TASK-3 potassium channel. The primary functional roles of these channels include regulation of mitochondrial respiration and the alteration of membrane potential. Additionally, they modulate the mitochondrial matrix volume and the synthesis of reactive oxygen species by mitochondria. Mitochondrial potassium channels are believed to contribute to cytoprotection and cell death. In this paper, we discuss fundamental issues concerning mitochondrial potassium channels: their molecular identity, channel pharmacology and functional properties. Attention will be given to the current problems present in our understanding of the nature of mitochondrial potassium channels. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi.
Assuntos
Mitocôndrias/metabolismo , Canais de Potássio Cálcio-Ativados/metabolismo , Canais de Potássio Corretores do Fluxo de Internalização/metabolismo , Canais de Potássio de Domínios Poros em Tandem/metabolismo , Canais de Potássio de Abertura Dependente da Tensão da Membrana/metabolismo , Animais , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Expressão Gênica , Humanos , Transporte de Íons , Mitocôndrias/efeitos dos fármacos , Miócitos Cardíacos/citologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Neurônios/citologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Especificidade de Órgãos , Plantas/efeitos dos fármacos , Plantas/metabolismo , Bloqueadores dos Canais de Potássio/farmacologia , Canais de Potássio Cálcio-Ativados/antagonistas & inibidores , Canais de Potássio Cálcio-Ativados/genética , Canais de Potássio Corretores do Fluxo de Internalização/antagonistas & inibidores , Canais de Potássio Corretores do Fluxo de Internalização/genética , Canais de Potássio de Domínios Poros em Tandem/antagonistas & inibidores , Canais de Potássio de Domínios Poros em Tandem/genética , Canais de Potássio de Abertura Dependente da Tensão da Membrana/antagonistas & inibidores , Canais de Potássio de Abertura Dependente da Tensão da Membrana/genética , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/metabolismo , Linfócitos T/citologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo , Trypanosomatina/efeitos dos fármacos , Trypanosomatina/metabolismoRESUMO
BACKGROUND: Angomonas deanei is a trypanosomatid parasite of insects that has a bacterial endosymbiont, which supplies amino acids and other nutrients to its host. Bacterium loss induced by antibiotic treatment of the protozoan leads to an aposymbiotic strain with increased need for amino acids and results in increased production of extracellular peptidases. In this work, a more detailed examination of A. deanei was conducted to determine the effects of endosymbiont loss on the host calpain-like proteins (CALPs), followed by testing of different calpain inhibitors on parasite proliferation. RESULTS: Western blotting showed the presence of different protein bands reactive to antibodies against calpain from Drosophila melanogaster (anti-Dm-calpain), lobster calpain (anti-CDPIIb) and cytoskeleton-associated calpain from Trypanosoma brucei (anti-CAP5.5), suggesting a possible modulation of CALPs influenced by the endosymbiont. In the cell-free culture supernatant of A. deanei wild type and aposymbiotic strains, a protein of 80 kDa cross-reacted with the anti-Dm-calpain antibody; however, no cross-reactivity was found with anti-CAP5.5 and anti-CDPIIb antibodies. A search in A. deanei genome for homologues of D. melanogaster calpain, T. brucei CAP5.5 and lobster CDPIIb calpain revealed the presence of hits with at least one calpain conserved domain and also with theoretical molecular mass consistent with the recognition by each antibody. No significant hit was observed in the endosymbiont genome, indicating that calpain molecules might be absent from the symbiont. Flow cytometry analysis of cells treated with the anti-calpain antibodies showed that a larger amount of reactive epitopes was located intracellularly. The reversible calpain inhibitor MDL28170 displayed a much higher efficacy in diminishing the growth of both strains compared to the non-competitive calpain inhibitor PD150606, while the irreversible calpain inhibitor V only marginally diminished the proliferation. CONCLUSIONS: Altogether, these results indicate that distinct calpain-like molecules are expressed by A. deanei, with a possible modulation in the expression influenced by the endosymbiont. In addition, treatment with MDL28170 affects the growth rate of both strains, as previously determined in the human pathogenic species Leishmania amazonensis and Trypanosoma cruzi, with whom A. deanei shares immunological and biochemical relationships.