Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Int J Parasitol Drugs Drug Resist ; 24: 100525, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38359731

RESUMO

Leishmaniasis is a disease caused by Leishmania spp., affecting millions of people around the world. For decades, its treatment has been based on pentavalent antimonials, which notoriously cause toxic side effects in patients. In this study, epoxy-α-lapachone incorporated into an oil-in-water-type microemulsion (ELAP-ME) and meglumine antimoniate (MA) were assayed in monotherapy and in combination (ELAP-ME/MA) in BALB/c mice infected with Leishmania (Leishmania) amazonensis. In general, there was a reduction in paw lesion size (up to 37% reduction) and decreases of parasite loads in the footpad (∼40%) and lymph nodes (∼31%) of animals treated with ELAP-ME/MA, when compared to the non-treated control groups. Analyses of serum biochemical parameters revealed that the ELAP-ME/MA showed lower renal and hepatic toxicity when compared to MA 2-doses/week monotherapy. These findings indicate that the ELAP-ME/MA combination may be a promising approach for the treatment of cutaneous leishmaniasis.


Assuntos
Antiprotozoários , Leishmania , Leishmaniose Cutânea , Naftoquinonas , Compostos Organometálicos , Humanos , Animais , Camundongos , Antimoniato de Meglumina/uso terapêutico , Leishmaniose Cutânea/tratamento farmacológico , Leishmaniose Cutânea/parasitologia , Meglumina/uso terapêutico , Compostos Organometálicos/uso terapêutico , Camundongos Endogâmicos BALB C
2.
Diseases ; 11(4)2023 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-37987264

RESUMO

Leishmaniasis is a neglected tropical illness with a wide variety of clinical signs ranging from visceral to cutaneous symptoms, resulting in millions of new cases and thousands of fatalities reported annually. This article provides a bibliometric analysis of the main authors' contributions, institutions, and nations in terms of productivity, citations, and bibliographic linkages to the application of nanoparticles (NPs) for the treatment of leishmania. The study is based on a sample of 524 Scopus documents from 1991 to 2022. Utilising the Bibliometrix R-Tool version 4.0 and VOSviewer software, version 1.6.17 the analysis was developed. We identified crucial subjects associated with the application of NPs in the field of antileishmanial development (NPs and drug formulation for leishmaniasis treatment, animal models, and experiments). We selected research topics that were out of date and oversaturated. Simultaneously, we proposed developing subjects based on multiple analyses of the corpus of published scientific literature (title, abstract, and keywords). Finally, the technique used contributed to the development of a broader and more specific "big picture" of nanomedicine research in antileishmanial studies for future projects.

3.
Mem. Inst. Oswaldo Cruz ; 118: e220225, 2023. graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1529019

RESUMO

BACKGROUND Leishmaniasis, a neglected disease caused by the parasite Leishmania, is treated with drugs associated with high toxicity and limited efficacy, in addition to constant reports of the emergence of resistant parasites. In this context, snake serums emerge as good candidates since they are natural sources with the potential to yield novel drugs. OBJECTIVES We aimed to show the antileishmanial effects of γCdcPLI, a phospholipase A2 inhibitor from Crotalus durissus collilineatus snake serum, against Leishmania (Leishmania) amazonensis. METHODS Promastigotes forms were exposed to γCdcPLI, and we assessed the parasite viability and cell cycle, as well as invasion and proliferation assays. FINDINGS Despite the low cytotoxicity effect on macrophages, our data indicate that γCdcPLI has a direct effect on parasites promoting an arrest in the G1 phase and reduction in the G2/M phase at the highest dose tested. Moreover, this PLA2 inhibitor reduced the parasite infectivity when promastigotes were pre-treated. Also, we demonstrated that the γCdcPLI treatment modulated the host cell environment impairing early and late steps of the parasitism. MAIN CONCLUSIONS γCdcPLI is an interesting tool for the discovery of new essential targets on the parasite, as well as an alternative compound to improve the effectiveness of the leishmaniasis treatment.

4.
Mem Inst Oswaldo Cruz, v.118, e220225, nov. 2023
Artigo em Inglês | Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP | ID: bud-5165

RESUMO

BACKGROUND Leishmaniasis, a neglected disease caused by the parasite Leishmania, is treated with drugs associated with high toxicity and limited efficacy, in addition to constant reports of the emergence of resistant parasites. In this context, snake serums emerge as good candidates since they are natural sources with the potential to yield novel drugs. OBJECTIVES We aimed to show the antileishmanial effects of γCdcPLI, a phospholipase A2 inhibitor from Crotalus durissus collilineatus snake serum, against Leishmania (Leishmania) amazonensis. METHODS Promastigotes forms were exposed to γCdcPLI, and we assessed the parasite viability and cell cycle, as well as invasion and proliferation assays. FINDINGS Despite the low cytotoxicity effect on macrophages, our data indicate that γCdcPLI has a direct effect on parasites promoting an arrest in the G1 phase and reduction in the G2/M phase at the highest dose tested. Moreover, this PLA2 inhibitor reduced the parasite infectivity when promastigotes were pre-treated. Also, we demonstrated that the γCdcPLI treatment modulated the host cell environment impairing early and late steps of the parasitism. MAIN CONCLUSIONS γCdcPLI is an interesting tool for the discovery of new essential targets on the parasite, as well as an alternative compound to improve the effectiveness of the leishmaniasis treatment.

5.
Microorganisms ; 9(4)2021 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-33918954

RESUMO

Leishmania parasites efficiently develop resistance against several types of drugs including antimonials, the primary antileishmanial drug historically implemented. The resistance to antimonials is considered to be a major risk factor for effective leishmaniasis treatment. To detect biomarkers/biopatterns for the differentiation of antimony-resistant Leishmania strains, we employed untargeted global mass spectrometry to identify intracellular lipids present in antimony sensitive and resistant parasites before and after antimony exposure. The lipidomic profiles effectively differentiated the sensitive and resistant phenotypes growing with and without antimony pressure. Resistant phenotypes were characterized by significant downregulation of phosphatidylcholines, sphingolipid decrease, and lysophosphatidylcholine increase, while sensitive phenotypes were characterized by the upregulation of triglycerides with long-chain fatty acids and a tendency toward the phosphatidylethanolamine decrease. Our findings suggest that the changes in lipid composition in antimony-resistant parasites contribute to the physiological response conducted to combat the oxidative stress unbalance caused by the drug. We have identified several lipids as potential biomarkers associated with the drug resistance.

6.
Drug Deliv Transl Res ; 10(2): 403-412, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31701487

RESUMO

Leishmaniasis occurs in the five continents and represents a serious public health challenge, but is still a neglected disease, and the current pharmacological weaponry is far from satisfactory. Triglyceride-rich nanoparticles mimicking chylomicrons (TGNP) behave metabolically like native chylomicrons when injected into the bloodstream. Previously we have shown that TGNP as vehicle to amphothericin B (AB) for treatment of fungi infection showed reduced renal toxicity and lower animal death rates compared to conventional AB. The aim of the current study was to test the tolerability and effectiveness of the TGNP-AB preparation in a murine model of Leishmania amazonensis infection. The in vitro assays determined the cytotoxicity of TGNP-AB, AB, and TGNP in macrophages and promastigote forms and the leishmanicidal activity in infected macrophages. The in vivo toxicity tests were performed in healthy mice with increasing doses of TGPN-AB and AB. Then, animals were treated with 2.5 mg/kg/day of AB, 17.5 mg/kg/day of TGNP-AB, or TGNP three times a week for 4 weeks. TGNP-AB formulation was less cytotoxic for macrophages than AB. TGNP-AB was more effective than AB against the promastigotes forms of the parasite and more effective in reducing the number of infected macrophages and the number of amastigotes forms per cell. TGNP-AB-treated animals showed lower hepatotoxicity. In addition, TGNP-AB group showed a marked reduction in lesion size on the paws and parasitic load. The TGNP-AB preparation attained excellent leishmanicidal activity with remarkable lower drug toxicity at very high doses that, due to the toxicity-buffering properties of the nanocarrier, become fully tolerable.


Assuntos
Anfotericina B/administração & dosagem , Antiprotozoários/administração & dosagem , Quilomícrons/química , Leishmaniose Cutânea/tratamento farmacológico , Triglicerídeos/química , Anfotericina B/química , Anfotericina B/farmacologia , Animais , Antiprotozoários/química , Antiprotozoários/farmacologia , Linhagem Celular , Modelos Animais de Doenças , Composição de Medicamentos , Feminino , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Mimetismo Molecular , Nanopartículas , Carga Parasitária
7.
Artigo em Inglês | MEDLINE | ID: mdl-31130997

RESUMO

BACKGROUND: Three drugs - pentavalent antimonials, amphotericin B and pentamidine - are currently used for leishmaniasis treatment. They are administered for long periods, only parenterally, and have high cardiac, renal and hepatic toxicities. Therefore, the investigation of new compounds is required. Nitro-heterocyclic derivatives have been used as possible drug candidates to treat diseases caused by trypanosomatids. METHODS: Leishmania (L.) amazonensis promastigotes (MHO/BR/73/M2269), maintained in the Laboratório de Soroepidemiologia - Instituto de Medicina Tropical- USP, were exposed to five nitroheterocyclic derivatives, with differences at phenyl-ring position 4: BSF-C4H9, BSF-H, BSF-NO2, BSF-CH3 and BSF-Cl, for 48 hours. After analyzing viability (MTT assay), we evaluated cellular-morphology activity of compounds by transmission electron microscopy (TEM) and measurement of apoptosis (phosphatidylserine expression) by flow cytometry. RESULTS: EC50 of amphotericin B and BSF-CH3 were 0.50 (M and 0.39 (M respective. Other nitro-heterocyclic compounds presented EC50 higher than amphotericin B. All compounds showed greater AV- and PI-positive expression than amphotericin B at 100 (M, except BSF-NO2. TEM showed complete nuclear disfigurement with 100 (M of BSF-NO2, 25 and 6.25 (M of BSF-H, and 6.25 (M BSF-Cl; presence of vesicles within the flagellar pocket with 25 (M BSF-H; alteration of the kinetoplast with 25 (M BSF-C4H9, 25 (M of BSF-H, 6.25 (M BSF-CH3 and 6.25 (M of BSF-Cl. CONCLUSIONS: Nitro-heterocyclic compounds have shown activity against promastigotes of L. amazonensis, at lower concentrations. However, improvement of compound scaffolds are needed to assist the elucidation of the mechanism of action and to achieve greater activity.

8.
J. venom. anim. toxins incl. trop. dis ; 25: e144418, 2019. tab, graf
Artigo em Inglês | Sec. Est. Saúde SP, SESSP-IIERPROD, Sec. Est. Saúde SP | ID: biblio-990127

RESUMO

Abstract Background: Three drugs - pentavalent antimonials, amphotericin B and pentamidine - are currently used for leishmaniasis treatment. They are administered for long periods, only parenterally, and have high cardiac, renal and hepatic toxicities. Therefore, the investigation of new compounds is required. Nitro-heterocyclic derivatives have been used as possible drug candidates to treat diseases caused by trypanosomatids. Methods: Leishmania (L.) amazonensis promastigotes (MHO/BR/73/M2269), maintained in the Laboratório de Soroepidemiologia - Instituto de Medicina Tropical- USP, were exposed to five nitroheterocyclic derivatives, with differences at phenyl-ring position 4: BSF-C4H9, BSF-H, BSF-NO2, BSF-CH3 and BSF-Cl, for 48 hours. After analyzing viability (MTT assay), we evaluated cellular-morphology activity of compounds by transmission electron microscopy (TEM) and measurement of apoptosis (phosphatidylserine expression) by flow cytometry. Results: EC50 of amphotericin B and BSF-CH3 were 0.50 (M and 0.39 (M respective. Other nitro-heterocyclic compounds presented EC50 higher than amphotericin B. All compounds showed greater AV- and PI-positive expression than amphotericin B at 100 (M, except BSF-NO2. TEM showed complete nuclear disfigurement with 100 (M of BSF-NO2, 25 and 6.25 (M of BSF-H, and 6.25 (M BSF-Cl; presence of vesicles within the flagellar pocket with 25 (M BSF-H; alteration of the kinetoplast with 25 (M BSF-C4H9, 25 (M of BSF-H, 6.25 (M BSF-CH3 and 6.25 (M of BSF-Cl. Conclusions: Nitro-heterocyclic compounds have shown activity against promastigotes of L. amazonensis, at lower concentrations. However, improvement of compound scaffolds are needed to assist the elucidation of the mechanism of action and to achieve greater activity.


Assuntos
Cobaias , Leishmaniose/tratamento farmacológico , Compostos Heterocíclicos
9.
Front Microbiol ; 9: 1427, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30018604

RESUMO

The present study focused on the activity of the palladacycle complex DPPE 1.1 on Leishmania (Leishmania) amazonensis. Promastigotes of L. (L.) amazonensis were destroyed in vitro by nanomolar concentrations of DPPE 1.1, whereas intracellular amastigotes were killed at drug concentrations fivefold less toxic than those harmful to macrophages. L. (L.) amazonensis-infected BALB/c mice were treated by intralesional injection of DPPE 1.1. Animals treated with 3.5 and 7.0 mg/kg of DPPE 1.1 showed a significant decrease of foot lesion sizes and a parasite load reduction of 93 and 99%, respectively, when compared to untreated controls. Furthermore, DPPE 1.1 was non-toxic to treated animals. The cathepsin B activity of L. (L.) amazonensis amastigotes was inhibited by DPPE 1.1 as demonstrated spectrofluorometrically by use of a specific fluorogenic substrate. Analysis of T-cells populations in mice treated with DPPE 1.1 and untreated controls was performed by fluorescence-activated cell sorter (FACS). IFN-γ was measured in supernatants of lymphocytes from popliteal and inguinal lymph nodes isolated from treated and untreated mice and stimulated with L. (L.) amazonensis amastigotes extract and active TGF-ß was evaluated in supernatants of foot lesions; both dosages were carried out by means of a double-sandwich ELISA assay. A significant increase of TCD4+ and TCD8+ lymphocytes and IFN-γ secretion was displayed in mice treated with DPPE 1.1 compared to untreated animals, whereas a significant reduction of active TGF-ß was observed in treated mice. These findings open perspectives for further investment in DPPE 1.1 as an alternative option for the chemotherapy of cutaneous leishmaniasis.

10.
Expert Rev Anti Infect Ther ; 16(5): 391-397, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29737887

RESUMO

INTRODUCTION: The increasing number of transplants performed worldwide and the growing global mobility with migration and travel to and from developing countries and tropical areas are bringing new challenges for the management of transplant infectious diseases, previously less commonly seen, such as Leishmaniasis. However, in this scenario there is a lack of information and the current knowledge is based on a few studies. The selection of the most appropriate treatment depends on various factors, such as patient profile, Leishmania species, disease extent, drug availability, concomitant infections and previous treatments. Therapeutic options may include different formulations of amphotericin B, pentavalent antimonials, miltefosine and paromomycin, among others. These drugs can be used alone or in combination. Areas covered: This review is a practical guide for Visceral Leishmaniasis (VL) specific treatment in solid organ transplant recipients (SOT), including therapeutic options and assessment of therapy response. Expert commentary: The main challenges for treatment of leishmaniasis in SOT recipients are related to the duration of therapy, curative criteria and secondary prophylaxis. Immunosuppression dose reduction is often recommended, but such decisions must be made on an individual basis. At present, Liposomal Amphotericin B is the best choice for treatment and prophylaxis.


Assuntos
Antiprotozoários/uso terapêutico , Leishmaniose Visceral/tratamento farmacológico , Transplantados , Anfotericina B/uso terapêutico , Animais , Humanos , Imunossupressores/administração & dosagem , Leishmaniose Visceral/parasitologia , Leishmaniose Visceral/prevenção & controle , Transplante de Órgãos , Prevenção Secundária/métodos
11.
J Integr Med ; 16(4): 211-222, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29691188

RESUMO

Leishmaniasis, a neglected disease caused by Leishmania protozoans, primarily affects people in tropical and subtropical areas. Chemotherapy based on the use of pentavalent antimonials, amphotericin B, paromomycin, miltefosine and liposomal amphotericin B is currently the only effective treatment. However, adverse effects, long-term treatment and the emergence of parasite resistance have led to the search for alternative treatments. Natural products used in traditional medicine provide an unlimited source of molecules for the identification of new drugs, and the Amazon region has abundant biodiversity that includes several species of plants and animals, providing a rich source of new products and compounds. Although the literature describes numerous promising compounds and extracts for combating Leishmania protozoans, the results of such research have not been embraced by the pharmaceutical industry for the development of new drugs. Therefore, this review focused on the antileishmanial activity of extracts, isolated compounds and essential oils commonly used by the local population in the Brazilian Amazonian region to treat several illnesses and described in the literature as promising compounds for combating leishmaniasis.


Assuntos
Antiprotozoários/química , Antiprotozoários/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Animais , Antiprotozoários/isolamento & purificação , Brasil , Humanos , Leishmania/efeitos dos fármacos , Leishmania/genética , Leishmania/crescimento & desenvolvimento , Leishmaniose/tratamento farmacológico , Leishmaniose/parasitologia , Extratos Vegetais/isolamento & purificação
12.
Parasitology ; 145(4): 464-480, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-28103966

RESUMO

Cutaneous and visceral leishmaniasis are amongst the most devastating infectious diseases of our time, affecting millions of people worldwide. The treatment of these serious diseases rely on a few chemotherapeutic agents, most of which are of parenteral use and induce severe side-effects. Furthermore, rates of treatment failure are high and have been linked to drug resistance in some areas. Here, we reviewed data on current chemotherapy practice in leishmaniasis. Drug resistance and mechanisms of resistance are described as well as the prospects for applying drug combinations for leishmaniasis chemotherapy. It is clear that efforts for discovering new drugs applicable to leishmaniasis chemotherapy are essential. The main aspects on the various steps of drug discovery in the field are discussed.


Assuntos
Descoberta de Drogas/métodos , Leishmania/efeitos dos fármacos , Leishmaniose Cutânea/tratamento farmacológico , Leishmaniose Visceral/tratamento farmacológico , Falha de Tratamento , Animais , Antiprotozoários/efeitos adversos , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Ensaios Clínicos como Assunto , Cricetinae , Modelos Animais de Doenças , Resistência a Múltiplos Medicamentos/genética , Quimioterapia Combinada/métodos , Humanos , Leishmaniose Cutânea/parasitologia , Leishmaniose Visceral/parasitologia , Camundongos
13.
Journal of Integrative Medicine ; (12): 211-222, 2018.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-691074

RESUMO

Leishmaniasis, a neglected disease caused by Leishmania protozoans, primarily affects people in tropical and subtropical areas. Chemotherapy based on the use of pentavalent antimonials, amphotericin B, paromomycin, miltefosine and liposomal amphotericin B is currently the only effective treatment. However, adverse effects, long-term treatment and the emergence of parasite resistance have led to the search for alternative treatments. Natural products used in traditional medicine provide an unlimited source of molecules for the identification of new drugs, and the Amazon region has abundant biodiversity that includes several species of plants and animals, providing a rich source of new products and compounds. Although the literature describes numerous promising compounds and extracts for combating Leishmania protozoans, the results of such research have not been embraced by the pharmaceutical industry for the development of new drugs. Therefore, this review focused on the antileishmanial activity of extracts, isolated compounds and essential oils commonly used by the local population in the Brazilian Amazonian region to treat several illnesses and described in the literature as promising compounds for combating leishmaniasis.


Assuntos
Animais , Humanos , Antiprotozoários , Química , Farmacologia , Brasil , Leishmania , Genética , Leishmaniose , Tratamento Farmacológico , Parasitologia , Extratos Vegetais , Química , Farmacologia , Plantas Medicinais , Química
14.
Cytokine ; 91: 6-9, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27940090

RESUMO

BACKGROUND: In Ethiopia, visceral leishmaniasis (VL) is a growing public health threat. Among the key challenges in VL control in Ethiopia is lack of an effective test of cure. The recommended test of cure is parasite detection. As sterile cure is not expected with the current widely used drugs, the value of parasite detection as test of cure is questionable. Moreover, the sampling is invasive, requires a well-equipped facility and highly skilled personnel, which are all hardly found in endemic set-ups. OBJECTIVE: Our aim was to assess the value of sCD40L, MMP9 and IL-10 serum levels as signature biomarkers of clinical cure in VL cases from Ethiopia. METHODS: A total of 45 VL cases before and after treatment and 30 endemic healthy controls were included in the study. Sandwich ELISA was used to measure serum levels of sCD40L, MMP9 and IL-10. RESULT: The mean sCD40L, MMP9 and IL-10 serum levels changed significantly at clinical cure. At individual case level sCD40L and MMP9 showed an increasing trend. Yet, the degree of increase in serum level of MMP9 seems to be affected by nutritional status of the individual VL case. The mean IL-10 serum level was significantly reduced at clinical cure. As seen on case by case basis, all demonstrated a declining trend except that two VL cases had a high IL10 level at clinical cure. CONCLUSION: Our result is suggestive of the possibility of developing a signature biomarker to monitor VL treatment in Ethiopia using one or a combination of parameters.


Assuntos
Gluconato de Antimônio e Sódio/administração & dosagem , Ligante de CD40/sangue , Interleucina-10/sangue , Leishmaniose Visceral , Metaloproteinase 9 da Matriz/sangue , Adulto , Etiópia , Feminino , Humanos , Leishmaniose Visceral/sangue , Leishmaniose Visceral/tratamento farmacológico , Masculino
15.
Braz. J. Pharm. Sci. (Online) ; 53(1): e16067, 2017. tab, graf
Artigo em Inglês | LILACS | ID: biblio-839450

RESUMO

ABSTRACT We describe herein the synthesis and evaluation of the antileishmanial activity against promastigote forms of Leishmania amazonensis and cytotoxicity to murine macrophages of a series of 2-chloro-N-arylacetamide derivatives. All compounds were active, except one (compound 3). Compound 5 presented the most promising results, showing good antileishmanial activity (CI50=5.39±0.67 µM) and moderate selectivity (SI=6.36), indicating that further development of this class is worthwhile. Preliminary QSAR studies, although not predictive, furnished some insights on the importance of electronic character of aryl substituent to biological activity, as well as an indirect influence of hydrophobicity on activity.


Assuntos
Animais , Feminino , Ratos , Leishmaniose/tratamento farmacológico , Relação Quantitativa Estrutura-Atividade , Leishmania mexicana/isolamento & purificação , Interações Hidrofóbicas e Hidrofílicas , Macrófagos/citologia
16.
J Mol Graph Model ; 55: 134-47, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25528729

RESUMO

Leishmaniases are caused by protozoa of the genus Leishmania and are considered the second-highest cause of death worldwide by parasitic infection. The drugs available for treatment in humans are becoming ineffective mainly due to parasite resistance; therefore, it is extremely important to develop a new chemotherapy against these parasites. A crucial aspect of drug design development is the identification and characterization of novel molecular targets. In this work, through an in silico comparative analysis between the genomes of Leishmania major and Homo sapiens, the enzyme ribose 5-phosphate isomerase (R5PI) was indicated as a promising molecular target. R5PI is an important enzyme that acts in the pentose phosphate pathway and catalyzes the interconversion of d-ribose-5-phosphate (R5P) and d-ribulose-5-phosphate (5RP). R5PI activity is found in two analogous groups of enzymes called RpiA (found in H. sapiens) and RpiB (found in L. major). Here, we present the first report of the three-dimensional (3D) structures and active sites of RpiB from L. major (LmRpiB) and RpiA from H. sapiens (HsRpiA). Three-dimensional models were constructed by applying a hybrid methodology that combines comparative and ab initio modeling techniques, and the active site was characterized based on docking studies of the substrates R5P (furanose and ring-opened forms) and 5RP. Our comparative analyses show that these proteins are structural analogs and that distinct residues participate in the interconversion of R5P and 5RP. We propose two distinct reaction mechanisms for the reversible isomerization of R5P to 5RP, which is catalyzed by LmRpiB and HsRpiA. We expect that the present results will be important in guiding future molecular modeling studies to develop new drugs that are specially designed to inhibit the parasitic form of the enzyme without significant effects on the human analog.


Assuntos
Aldose-Cetose Isomerases/química , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Leishmania major/enzimologia , Simulação de Acoplamento Molecular , Homologia Estrutural de Proteína , Aldose-Cetose Isomerases/metabolismo , Sequência de Aminoácidos , Domínio Catalítico , Humanos , Isomerismo , Leishmania major/efeitos dos fármacos , Leishmaniose Cutânea/tratamento farmacológico , Ligantes , Dados de Sequência Molecular , Ribosemonofosfatos/química , Ribosemonofosfatos/metabolismo , Ribulosefosfatos/química , Ribulosefosfatos/metabolismo , Eletricidade Estática , Especificidade por Substrato/efeitos dos fármacos
17.
Medicina (B Aires) ; 74(5): 371-7, 2014.
Artigo em Espanhol | MEDLINE | ID: mdl-25347898

RESUMO

The conventional treatment for tegumentary leishmaniasis is meglumine antimoniate, which needs parenteral administration, has increased therapeutic failure, and produces serious adverse effects, justifying the search for therapeutic alternatives. We report here the preliminary results of a phase II clinical trial in patients with mucosal leishmaniasis, in which the efficacy of oral miltefosine versus the antimonial compound was assessed. The evaluation of response to the treatment was performed by monitoring with nasopharyngeal video-fibroscopy, using a score of mucosal injury severity for patients at each follow-up point. We found no significant differences so far between the number of patients cured with miltefosine or conventional chemotherapy. The favorable results of this study suggest that miltefosine could be an effective and safe oral therapeutic alternative in the region.


Assuntos
Antiprotozoários/uso terapêutico , Leishmaniose Mucocutânea/tratamento farmacológico , Meglumina/uso terapêutico , Compostos Organometálicos/uso terapêutico , Fosforilcolina/análogos & derivados , Adolescente , Adulto , Idoso , Pesquisa Comparativa da Efetividade , Feminino , Humanos , Escala de Gravidade do Ferimento , Masculino , Antimoniato de Meglumina , Pessoa de Meia-Idade , Nasofaringe/parasitologia , Fosforilcolina/uso terapêutico , Adulto Jovem
18.
Medicina (B.Aires) ; 74(5): 371-377, oct. 2014. ilus, tab
Artigo em Espanhol | BINACIS | ID: bin-131424

RESUMO

El tratamiento convencional para la leishmaniasis tegumentaria es el antimoniato de meglumina, el cual presenta falla terapéutica creciente, producción de efectos adversos graves, y necesidad de administración parenteral, justificando la búsqueda de alternativas terapéuticas. Presentamos aquí los resultados preliminares de un ensayo clínico de fase II en pacientes con leishmaniasis mucosa, en el que se comparó la eficacia de miltefosina por vía oral con respecto a la del compuesto antimonial. La evaluación de la respuesta a los tratamientos se realizó mediante un seguimiento con videofibroscopia nasofaríngea, utilizándose un score de gravedad de lesiones mucosas para aplicar en cada momento del seguimiento de los pacientes. No se encontraron hasta ahora diferencias significativas entre el número de pacientes curados con miltefosina o con la quimioterapia convencional. Los resultados favorables de este trabajo sugieren que miltefosina podría constituir una alternativa terapéutica efectiva y segura en la región.(AU)


The conventional treatment for tegumentary leishmaniasis is meglumine antimoniate, which needs parenteral administration, has increased therapeutic failure, and produces serious adverse effects, justifying the search for therapeutic alternatives. We report here the preliminary results of a phase II clinical trial in patients with mucosal leishmaniasis, in which the efficacy of oral miltefosine versus the antimonial compound was assessed. The evaluation of response to the treatment was performed by monitoring with nasopharyngeal video-fibroscopy, using a score of mucosal injury severity for patients at each follow-up point. We found no significant differences so far between the number of patients cured with miltefosine or conventional chemotherapy. The favorable results of this study suggest that miltefosine could be an effective and safe oral therapeutic alternative in the region.(AU)

19.
Medicina (B.Aires) ; 74(5): 371-377, oct. 2014. ilus, tab
Artigo em Espanhol | LILACS | ID: lil-734403

RESUMO

El tratamiento convencional para la leishmaniasis tegumentaria es el antimoniato de meglumina, el cual presenta falla terapéutica creciente, producción de efectos adversos graves, y necesidad de administración parenteral, justificando la búsqueda de alternativas terapéuticas. Presentamos aquí los resultados preliminares de un ensayo clínico de fase II en pacientes con leishmaniasis mucosa, en el que se comparó la eficacia de miltefosina por vía oral con respecto a la del compuesto antimonial. La evaluación de la respuesta a los tratamientos se realizó mediante un seguimiento con videofibroscopia nasofaríngea, utilizándose un score de gravedad de lesiones mucosas para aplicar en cada momento del seguimiento de los pacientes. No se encontraron hasta ahora diferencias significativas entre el número de pacientes curados con miltefosina o con la quimioterapia convencional. Los resultados favorables de este trabajo sugieren que miltefosina podría constituir una alternativa terapéutica efectiva y segura en la región.


The conventional treatment for tegumentary leishmaniasis is meglumine antimoniate, which needs parenteral administration, has increased therapeutic failure, and produces serious adverse effects, justifying the search for therapeutic alternatives. We report here the preliminary results of a phase II clinical trial in patients with mucosal leishmaniasis, in which the efficacy of oral miltefosine versus the antimonial compound was assessed. The evaluation of response to the treatment was performed by monitoring with nasopharyngeal video-fibroscopy, using a score of mucosal injury severity for patients at each follow-up point. We found no significant differences so far between the number of patients cured with miltefosine or conventional chemotherapy. The favorable results of this study suggest that miltefosine could be an effective and safe oral therapeutic alternative in the region.


Assuntos
Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Antiprotozoários/uso terapêutico , Leishmaniose Mucocutânea/tratamento farmacológico , Meglumina/uso terapêutico , Compostos Organometálicos/uso terapêutico , Fosforilcolina/análogos & derivados , Pesquisa Comparativa da Efetividade , Escala de Gravidade do Ferimento , Nasofaringe/parasitologia , Fosforilcolina/uso terapêutico
20.
J Family Community Med ; 16(2): 41-7, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-23012189

RESUMO

BACKGROUND: Cutaneous leishmaniasis (CL) is still a major health problem in many countries including Saudi Arabia. Patients with CL are seen, not only by dermatologists, but also by pediatricians and community physicians. Knowledge of available treatment options is essential. DESIGN: A literature review utilizing PubMed and Cochrane evidence-based library was undertaken in the last five years. RESULTS: Several medications and therapeutic modalities are currently in use, though the gold standard remains systemic antimonials. Drug resistance and serious side effects preclude the use of available medications. Newer therapies like liposomal amphotericin B, miltefosine and pentamidine are being used; while it is hoped that other drugs like imiquimod, tamoxifen, PDT and pentamidine structural analogs being tested would offer better efficacy, easier administration and lower toxicity. CONCLUSION: After decades of little advance in the treatment of leishmaniasis, there are now several options with newer compounds and combinations of these.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...