RESUMEN
Miltefosine (MTS) is the only approved oral drug for treating leishmaniasis caused by intracellular Leishmania parasites that localize in macrophages of the liver, spleen, skin, bone marrow, and lymph nodes. MTS is extensively distributed in tissues and has prolonged elimination half-lives due to its high plasma protein binding, slow metabolic clearance, and minimal urinary excretion. Thus, understanding and predicting the tissue distribution of MTS help assess therapeutic and toxicologic outcomes of MTS, especially in special populations, e.g., pediatrics. In this study, a whole-body physiologically-based pharmacokinetic (PBPK) model of MTS was built on mice and extrapolated to rats and humans. MTS plasma and tissue concentration data obtained by intravenous and oral administration to mice were fitted simultaneously to estimate model parameters. The resulting high tissue-to-plasma partition coefficient values corroborate extensive distribution in all major organs except the bone marrow. Sensitivity analysis suggests that plasma exposure is most susceptible to changes in fraction unbound in plasma. The murine oral-PBPK model was further validated by assessing overlay of simulations with plasma and tissue profiles obtained from an independent study. Subsequently, the murine PBPK model was extrapolated to rats and humans based on species-specific physiological and drug-related parameters, as well as allometrically scaled parameters. Fold errors for pharmacokinetic parameters were within acceptable range in both extrapolated models, except for a slight underprediction in the human plasma exposure. These animal and human PBPK models are expected to provide reliable estimates of MTS tissue distribution and assist dose regimen optimization in special populations.
Asunto(s)
Antiprotozoarios , Fosforilcolina , Fosforilcolina/análogos & derivados , Fosforilcolina/farmacocinética , Animales , Antiprotozoarios/farmacocinética , Ratones , Humanos , Ratas , Distribución Tisular , Administración Oral , Masculino , FemeninoRESUMEN
INTRODUCTION: Post-kala-azar dermal leishmaniasis (PKDL) arises as a dermal complication following a visceral leishmaniasis (VL) infection. Current treatment options for PKDL are unsatisfactory, and there is a knowledge gap regarding the distribution of antileishmanial compounds within human skin. The present study investigated the skin distribution of miltefosine in PKDL patients, with the aim to improve the understanding of the pharmacokinetics at the skin target site in PKDL. METHODS: Fifty-two PKDL patients underwent treatment with liposomal amphotericin B (20â mg/kg) plus miltefosine (allometric dosing) for 21 days. Plasma concentrations of miltefosine were measured on study days 8, 15, 22 and 30, while a punch skin biopsy was taken on day 22. A physiologically based pharmacokinetic (PBPK) model was developed to evaluate the distribution of miltefosine into the skin. RESULTS: Following the allometric weight-based dosing regimen, median miltefosine concentrations on day 22 were 43.73â µg/g (IQR: 21.94-60.65â µg/g) in skin and 33.29â µg/mL (IQR: 25.9-42.58â µg/mL) in plasma. The median individual concentration ratio of skin to plasma was 1.19 (IQR: 0.79-1.9). In 87% (45/52) of patients, skin exposure was above the suggested EC90 PK target of 10.6â mg/L associated with in vitro susceptibility. Simulations indicated that the residence time of miltefosine in the skin would be more than 2-fold longer than in plasma, estimated by a mean residence time of 604 versus 266 hours, respectively. CONCLUSION: This study provides the first accurate measurements of miltefosine penetration into the skin, demonstrating substantial exposure and prolonged retention of miltefosine within the skin. These findings support the use of miltefosine in cutaneous manifestations of leishmaniasis. In combination with parasitological and clinical data, these results are critical for the future optimization of combination therapies with miltefosine in the treatment of PKDL.
Asunto(s)
Anfotericina B , Antiprotozoarios , Leishmaniasis Cutánea , Leishmaniasis Visceral , Fosforilcolina , Piel , Humanos , Fosforilcolina/análogos & derivados , Fosforilcolina/farmacocinética , Fosforilcolina/administración & dosificación , Fosforilcolina/uso terapéutico , Antiprotozoarios/farmacocinética , Antiprotozoarios/administración & dosificación , Antiprotozoarios/uso terapéutico , Masculino , Adulto , Leishmaniasis Cutánea/tratamiento farmacológico , Leishmaniasis Cutánea/parasitología , Femenino , Piel/parasitología , Leishmaniasis Visceral/tratamiento farmacológico , Persona de Mediana Edad , Adulto Joven , Anfotericina B/farmacocinética , Anfotericina B/uso terapéutico , Anfotericina B/administración & dosificación , Adolescente , Sur de AsiaRESUMEN
Poor drug penetration, emerging drug resistance, and systemic toxicity are among the major obstacles challenging the current treatment of cutaneous leishmaniasis. Hence, developing advanced strategies for effective and targeted delivery of antileishmanial agents is crucial. Several drug delivery carriers have been developed till current date for dermal/transdermal delivery, especially those which are fabricated using eco-friendly synthesis approaches, since they protect the environment from the harmful effects of chemical waste disposal. This work describes the preparation of selenium nanoparticles loaded with silymarin via one-pot green reduction technique, for treatment of cutaneous leishmaniasis. The selected silymarin loaded selenium nanoparticles (SSNs4-0.1) displayed good loading efficiency of 58.22 ± 0.56 %, zeta potential of -30.63 ± 0.40 mV, hydrodynamic diameter of 245.77 ± 11.12 nm, and polydispersity index of 0.19 ± 0.01. It exhibited good physical stability, as well as high ex vivo deposition % in the epidermis (46.98 ± 1.51 %) and dermis (35.23 ± 1.72 %), which was further proven using confocal laser microscopy. It also exhibited significant cytocompatibility and noticeable cellular internalization of 90.02 ± 3.81 % in human fibroblasts, as well as high trypanothione reductase inhibitory effect (97.10 ± 0.30 %). Results of this study confirmed the successful green synthesis of silymarin-loaded selenium nanoparticles; delineating them as one of the promising antileishmanial topical delivery systems.
Asunto(s)
Antiprotozoarios , Portadores de Fármacos , Tecnología Química Verde , Nanopartículas , Selenio , Silimarina , Selenio/química , Selenio/administración & dosificación , Antiprotozoarios/administración & dosificación , Antiprotozoarios/farmacología , Antiprotozoarios/química , Antiprotozoarios/farmacocinética , Humanos , Silimarina/administración & dosificación , Silimarina/química , Silimarina/farmacología , Silimarina/farmacocinética , Portadores de Fármacos/química , Nanopartículas/química , Tecnología Química Verde/métodos , Animales , Administración Cutánea , Leishmaniasis Cutánea/tratamiento farmacológico , Fibroblastos/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Línea CelularRESUMEN
Leishmaniasis is a neglected tropical disease that is estimated to afflict over 12 million people. Current drugs for leishmaniasis suffer from serious deficiencies, including toxicity, high cost, modest efficacy, primarily parenteral delivery, and emergence of widespread resistance. We have discovered and developed a natural product-inspired tambjamine chemotype, known to be effective against Plasmodium spp, as a novel class of antileishmanial agents. Herein, we report in vitro and in vivo antileishmanial activities, detailed structure-activity relationships, and metabolic/pharmacokinetic profiles of a large library of tambjamines. A number of tambjamines exhibited excellent potency against both Leishmania mexicana and Leishmania donovani parasites with good safety and metabolic profiles. Notably, tambjamine 110 offered excellent potency and provided partial protection to leishmania-infected mice at 40 and/or 60 mg/kg/10 days of oral treatment. This study presents the first account of antileishmanial activity in the tambjamine family and paves the way for the generation of new oral antileishmanial drugs.
Asunto(s)
Antiprotozoarios , Leishmania donovani , Leishmania mexicana , Animales , Relación Estructura-Actividad , Antiprotozoarios/farmacología , Antiprotozoarios/química , Antiprotozoarios/uso terapéutico , Antiprotozoarios/síntesis química , Antiprotozoarios/farmacocinética , Ratones , Leishmania donovani/efectos de los fármacos , Leishmania mexicana/efectos de los fármacos , Descubrimiento de Drogas , Humanos , Femenino , Leishmaniasis/tratamiento farmacológico , Ratones Endogámicos BALB CRESUMEN
The bioluminescent Leishmania infantum BALB/c mouse model was used to evaluate the parasiticidal drug action kinetics of the reference drugs miltefosine, paromomycin, sodium stibogluconate, and liposomal amphotericin B. Infected mice were treated for 5 days starting from 7 days post-infection, and parasite burdens were monitored over time via bioluminescence imaging (BLI). Using nonlinear regression analyses of the BLI signal, the parasite elimination half-life (t1/2) in the liver, bone marrow, and whole body was determined and compared for the different treatment regimens. Significant differences in parasiticidal kinetics were recorded. A single intravenous dose of 0.5 mg/kg liposomal amphotericin B was the fastest acting with a t1/2 of less than 1 day. Intraperitoneal injection of paromomycin at 320 mg/kg for 5 days proved to be the slowest with a t1/2 of about 5 days in the liver and 16 days in the bone marrow. To conclude, evaluation of the cidal kinetics of the different antileishmanial reference drugs revealed striking differences in their parasite elimination half-lives. This BLI approach also enables an in-depth pharmacodynamic comparison between novel drug leads and may constitute an essential tool for the design of potential drug combinations.
Asunto(s)
Antiprotozoarios , Leishmania infantum , Leishmaniasis Visceral , Mediciones Luminiscentes , Ratones Endogámicos BALB C , Animales , Leishmania infantum/efectos de los fármacos , Antiprotozoarios/farmacología , Antiprotozoarios/farmacocinética , Leishmaniasis Visceral/tratamiento farmacológico , Leishmaniasis Visceral/parasitología , Ratones , Femenino , Hígado/parasitología , Hígado/efectos de los fármacos , Médula Ósea/parasitología , Médula Ósea/efectos de los fármacos , Cinética , Modelos Animales de EnfermedadRESUMEN
BACKGROUND: With the current treatment options for visceral leishmaniasis (VL), recrudescence of the parasite is seen in a proportion of patients. Understanding parasite dynamics is crucial to improving treatment efficacy and predicting patient relapse in cases of VL. This study aimed to characterize the kinetics of circulating Leishmania parasites in the blood, during and after different antileishmanial therapies, and to find predictors for clinical relapse of disease. METHODS: Data from three clinical trials, in which Eastern African VL patients received various antileishmanial regimens, were combined in this study. Leishmania kinetoplast DNA was quantified in whole blood with real-time quantitative PCR (qPCR) before, during, and up to six months after treatment. An integrated population pharmacokinetic-pharmacodynamic model was developed using non-linear mixed effects modelling. RESULTS: Parasite proliferation was best described by an exponential growth model, with an in vivo parasite doubling time of 7.8 days (RSE 12%). Parasite killing by fexinidazole, liposomal amphotericin B, sodium stibogluconate, and miltefosine was best described by linear models directly relating drug concentrations to the parasite elimination rate. After treatment, parasite growth was assumed to be suppressed by the host immune system, described by an Emax model driven by the time after treatment. No predictors for the high variability in onset and magnitude of the immune response could be identified. Model-based individual predictions of blood parasite load on Day 28 and Day 56 after start of treatment were predictive for clinical relapse of disease. CONCLUSION: This semi-mechanistic pharmacokinetic-pharmacodynamic model adequately captured the blood parasite dynamics during and after treatment, and revealed that high blood parasite loads on Day 28 and Day 56 after start of treatment are an early indication for VL relapse, which could be a useful biomarker to assess treatment efficacy of a treatment regimen in a clinical trial setting.
Asunto(s)
Antiprotozoarios , Leishmaniasis Visceral , Nitroimidazoles , Fosforilcolina/análogos & derivados , Leishmaniasis Visceral/tratamiento farmacológico , Leishmaniasis Visceral/parasitología , Humanos , Antiprotozoarios/farmacocinética , Antiprotozoarios/uso terapéutico , Antiprotozoarios/farmacología , Adulto , Femenino , Masculino , Adulto Joven , Adolescente , África Oriental , Anfotericina B/farmacocinética , Anfotericina B/uso terapéutico , Anfotericina B/farmacología , Recurrencia , ADN de Cinetoplasto/genética , Carga de Parásitos , Persona de Mediana Edad , Niño , Gluconato de Sodio Antimonio/uso terapéutico , Gluconato de Sodio Antimonio/farmacocinética , Preescolar , ADN Protozoario/genéticaRESUMEN
OBJECTIVES: To improve visceral leishmaniasis (VL) treatment in Eastern Africa, 14- and 28-day combination regimens of paromomycin plus allometrically dosed miltefosine were evaluated. As the majority of patients affected by VL are children, adequate paediatric exposure to miltefosine and paromomycin is key to ensuring good treatment response. METHODS: Pharmacokinetic data were collected in a multicentre randomized controlled trial in VL patients from Kenya, Sudan, Ethiopia and Uganda. Patients received paromomycin (20 mg/kg/day for 14 days) plus miltefosine (allometric dose for 14 or 28 days). Population pharmacokinetic models were developed. Adequacy of exposure and target attainment of paromomycin and miltefosine were evaluated in children and adults. RESULTS: Data from 265 patients (59% ≤12 years) were available for this pharmacokinetic analysis. Paromomycin exposure was lower in paediatric patients compared with adults [median (IQR) end-of-treatment AUC0-24h 187 (162-203) and 242 (217-328) µg·h/mL, respectively], but were both within the IQR of end-of-treatment exposure in Kenyan and Sudanese adult patients from a previous study. Cumulative miltefosine end-of-treatment exposure in paediatric patients and adults [AUCD0-28 517 (464-552) and 524 (456-567) µg·day/mL, respectively] and target attainment [time above the in vitro susceptibility value EC90 27 (25-28) and 30 (28-32) days, respectively] were comparable to previously observed values in adults. CONCLUSIONS: Paromomycin and miltefosine exposure in this new combination regimen corresponded to the desirable levels of exposure, supporting the implementation of the shortened 14 day combination regimen. Moreover, the lack of a clear exposure-response and exposure-toxicity relationship indicated adequate exposure within the therapeutic range in the studied population, including paediatric patients.
Asunto(s)
Antiprotozoarios , Leishmaniasis Visceral , Humanos , Adulto , Niño , Paromomicina/uso terapéutico , Leishmaniasis Visceral/tratamiento farmacológico , Antiprotozoarios/farmacocinética , Kenia , Fosforilcolina/uso terapéutico , Fosforilcolina/farmacocinética , Uganda , Resultado del TratamientoRESUMEN
Leishmaniasis caused by the protozoan Leishmania presents a severe illness, principally in tropical and subtropical areas. Antileishmanial metal complexes, like Glucantime®ï¸ with proven activity, are routinely studied to probe their potency. We investigated the effects of a Cu (II) homoleptic complex coordinated by two dimethyl-bipyridine ligands against Leishmania major stages in silico and in vitro. The affinity of this heterocyclic Cu (II) complex (CuDMBP) towards a parasitic metacaspase was studied by molecular docking. Key pharmacokinetic and pharmacodynamic properties of the complex were predicted using three web-based tools. CuDMBP was tested for in vitro antileishmanial activities using MTT assay, model murine macrophages, flow cytometry, and quantitative real-time polymerase chain reaction (qPCR). Molecular docking confirmed the tendency between the target macromolecule and the complex. ADMET evaluations highlighted CuDMBP's key pharmacological features, including P-glycoprotein-associated GI absorption and lack of trans-BBB permeability. MTT showed significant inhibitory effects against promastigotes. CuDMBP significantly increased the level of cellular IL-12 expression (p < 0.05), while the upregulation observed in the expression of iNOS was considered not significant (p > 0.05). It decreased the expression of IL-10 significantly (p < 0.05). Findings demonstrated that CuDMBP deserves to be introduced as a leishmanicidal candidate provided further studies are carried out.
Asunto(s)
Antiprotozoarios , Simulación por Computador , Cobre , Técnicas In Vitro , Leishmania major , Animales , Ratones , Apoptosis/efectos de los fármacos , Sitios de Unión , Caspasas/metabolismo , Colorimetría , Cobre/química , Cobre/farmacocinética , Cobre/farmacología , Cobre/toxicidad , Citometría de Flujo , Interleucina-12/genética , Leishmania major/efectos de los fármacos , Leishmania major/enzimología , Macrófagos/efectos de los fármacos , Antiprotozoarios/química , Antiprotozoarios/farmacocinética , Antiprotozoarios/farmacología , Antiprotozoarios/toxicidad , Modelos MolecularesRESUMEN
The increasing resistance of Toxoplasma gondii to drugs and side effects of therapy indicate that specific treatment for these parasites is still needed. The 4-arylthiosemicarbazide derivatives seem to be a solution to this challenge because they have low cytotoxicity against host cells and high anti-T. gondii activity. The molecular mechanism for these compounds is related to the inhibition of tyrosine amino acids involved in the proliferation and parasitophorous vacuole formation. The pharmacokinetic analysis shows that 1-(4-Methylimidazol-5-oyl)-4-(4-nitrophenyl)thiosemicarbazide and 4-(3-Iodophenyl)-1-(4-methylimidazol-5-oyl)thiosemicarbazide administered intragastrically pass into the bloodstream and cross the blood-brain barrier, and the absorption of both compounds is first-order absorption. Toxicity analysis shows that our derivatives possess lower toxicity than the routinely used drugs trimethoprim, sulfadiazine and pyrimethamine, as was observed in the level of liver enzymes and creatinine. Both derivatives are highly potent antiparasitic agents against T. gondii, prolonged survival and cure parasite-infected mice. Additionally, significant reductions in cyst formation in the brain and heart were observed, but the highest decreases were noted in muscle and the level of bradyzoites was similar to these observed in mice treated with commercially used drugs. Collectively, the obtained results support the conclusion that both compounds are highly efficacious in a mouse model of acute and chronic toxoplasmosis.
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Antiprotozoarios , Semicarbacidas , Toxoplasma , Toxoplasmosis , Animales , Ratones , Antiprotozoarios/química , Antiprotozoarios/farmacocinética , Antiprotozoarios/toxicidad , Semicarbacidas/química , Semicarbacidas/farmacocinética , Semicarbacidas/toxicidad , Toxoplasma/efectos de los fármacos , Toxoplasmosis/tratamiento farmacológicoRESUMEN
Leishmaniasis is a public health issue. It is among the top five parasitic illnesses worldwide and is one of the most neglected diseases. The current treatment disease includes limitations of toxicity, variable efficacy, high costs and inconvenient doses and treatment schedules. LASSBio-1736 was described as antileishmanial drug-candidate to cutaneous leishmaniasis, displaying plasma stability and with no preliminary signals of hepatic or renal toxicity. In this paper, we described the in vitro pharmacokinetic study of LASSBio-1491 (a less lipophilic isostere of LASSBio-1736) and it is in vitro and in vivo leishmanicidal activities. Our results demonstrated that LASSBio-1491 has high permeability, satisfactory aqueous solubility, long plasma and microsomal half-lives and low in vitro systemic clearance, suggesting a pharmacokinetic profile suitable for its use in a single daily dose. The antileishmanial effect of LASSBio-1491 was confirmed in vitro and in vivo. It exhibited no cytotoxic effect to mammalian cells and displayed good in -vivo effect against BALB/c mice infected with Leishmania major LV39 substrain, being 3 times more efficient than glucantime.
Asunto(s)
Antiprotozoarios , Leishmania major , Leishmaniasis Cutánea , Animales , Antiprotozoarios/farmacocinética , Antiprotozoarios/uso terapéutico , Leishmaniasis Cutánea/tratamiento farmacológico , Mamíferos , Ratones , Ratones Endogámicos BALB C , Enfermedades Desatendidas/tratamiento farmacológicoRESUMEN
Background: A high-throughput method using inductively coupled plasma mass spectrometry (ICP-MS) was developed and validated for the quantitative analysis of antimony in human plasma and peripheral blood mononuclear cells from patients with cutaneous leishmaniasis undergoing treatment with meglumine antimoniate. Materials & methods: Antimony was digested in clinical samples with 1% tetramethylammonium hydroxide/1% EDTA and indium was used as internal standard. Accuracy, precision and stability were evaluated. Conclusion: Taking the lower limit of quantitation to be the lowest validation concentration with precision and accuracy within 20%, the current assay was successfully validated from 25 to 10000 ng/ml for antimony in human plasma and peripheral blood mononuclear cells. This protocol will serve as a baseline for future analytical designs, aiming to provide a reference method to allow inter-study comparisons.
Lay abstract Cutaneous leishmaniasis is a disease caused by single-cell parasites in the genus Leishmania which results in painful skin ulcers and is spread by insect bites. Drugs containing antimony are the mainstay therapy for cutaneous leishmaniasis, but if and how the amount of these compounds in the cells can affect the success of the treatment, remains unknown. Validated methods to reliably measure these amounts in human cells are limited. Here we have developed a validated method that allows quantifying antimony in human plasma and peripheral blood cells from patients undergoing antileishmanial treatment. This protocol will serve as a baseline for future studies aiming to understand how antimonials work to treat leishmaniasis infections and how this therapy can be improved.
Asunto(s)
Antimonio/química , Antiprotozoarios/farmacocinética , Antimoniato de Meglumina/farmacocinética , Antimonio/sangre , Antiprotozoarios/sangre , Antiprotozoarios/química , Humanos , Leishmania/efectos de los fármacos , Espectrometría de Masas , Antimoniato de Meglumina/sangre , Antimoniato de Meglumina/química , Estructura Molecular , Pruebas de Sensibilidad ParasitariaRESUMEN
BACKGROUND: There is a continued need to develop effective and safe treatments for visceral leishmaniasis (VL). Preclinical studies on pharmacokinetics and pharmacodynamics of anti-infective agents, such as anti-bacterials and anti-fungals, have provided valuable information in the development and dosing of these agents. The aim of this study was to characterise the pharmacokinetic and pharmacodynamic properties of the anti-leishmanial drugs AmBisome and miltefosine in a preclinical disease model of VL. METHODOLOGY / PRINCIPAL FINDINGS: BALB/c mice were infected with L. donovani (MHOM/ET/67/HU3) amastigotes. Groups of mice were treated with miltefosine (orally, multi-dose regimen) or AmBisome (intravenously, single dose regimen) or left untreated as control groups. At set time points groups of mice were killed and plasma, livers and spleens harvested. For pharmacodynamics the hepatic parasite burden was determined microscopically from tissue impression smears. For pharmacokinetics drug concentrations were measured in plasma and whole tissue homogenates by LC-MS. Unbound drug concentrations were determined by rapid equilibrium dialysis. Doses exerting maximum anti-leishmanial effects were 40 mg/kg for AmBisome and 150 mg/kg (cumulatively) for miltefosine. AmBisome displayed a wider therapeutic range than miltefosine. Dose fractionation at a total dose of 2.5 mg/kg pointed towards concentration-dependent anti-leishmanial activity of AmBisome, favouring the administration of large doses infrequently. Protein binding was >99% for miltefosine and amphotericin B in plasma and tissue homogenates. CONCLUSION / SIGNIFICANCE: Using a PK/PD approach we propose optimal dosing strategies for AmBisome. Additionally, we describe pharmacokinetic and pharmacodynamic properties of miltefosine and compare our findings in a preclinical disease model to available knowledge from studies in humans. This approach also presents a strategy for improved use of animal models in the drug development process for VL.
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Anfotericina B/farmacocinética , Antiprotozoarios/farmacocinética , Leishmaniasis Visceral/tratamiento farmacológico , Fosforilcolina/análogos & derivados , Anfotericina B/uso terapéutico , Animales , Antiprotozoarios/uso terapéutico , Quimioterapia Combinada , Proteínas de Homeodominio/genética , Humanos , Hígado/parasitología , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Carga de Parásitos , Fosforilcolina/farmacocinética , Fosforilcolina/uso terapéutico , Unión Proteica/fisiologíaRESUMEN
Despite all efforts to provide new chemical entities to tackle leishmaniases, we are still dependent on a the limited drug arsenal, together with drawbacks like toxicity and drug-resistant parasites. Collaborative drug discovery emerged as an option to speed up the way to find alternative antileishmanial agents. This is the case of Medicines for Malaria Ventures - MMV, that promotes an open source drug discovery initiative to fight diseases worldwide. Here, we screened 400 compounds from 'Pathogen Box' (PBox) collection against Leishmania braziliensis, the main etiological agent of cutaneous leishmaniasis in Brazil. Twenty-three compounds were able to inhibit ≥ 80 % L. braziliensis growth at 5 µM. Six out of the PBox selected 23 compounds were found to be highly selective against L. braziliensis intracellular amastigotes with selectivity index varying from > 104 to > 746 and IC50s ranging from 47 to 480 nM. The compounds were also active against antimony-resistant L. braziliensis isolated from the field or laboratory selected mutants, revealing the potential on treating patients infected with drug resistant parasites. Most of the selected compounds were known to be active against kinetoplastids, however, two compounds (MMV688703 and MMV676477) were part of toxoplasmosis and tuberculosis 'PBox' disease set, reinforcing the potential of phenotyping screening to unveil drug repurposing. Here we applied a computational prediction of pharmacokinetic properties using the ADMET predictor pkCSM (http://biosig.unimelb.edu.au/pkcsm/). The tool offered clues on potential drug development needs and can support further in vivo studies. Molecular docking analysis identified CRK3 (LbrM.35.0660), CYP450 (LbrM.30.3580) and PKA (LbrM.18.1180) as L. braziliensis targets for MMV676604, MMV688372 and MMV688703, respectively. Compounds from 'Pathogen Box' thus represents a new hope for novel (or repurposed) small molecules source to tackle leishmaniases.
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Antimonio/farmacología , Antiprotozoarios/farmacología , Descubrimiento de Drogas , Reposicionamiento de Medicamentos , Resistencia a Medicamentos , Leishmania braziliensis/efectos de los fármacos , Bibliotecas de Moléculas Pequeñas , Animales , Antiprotozoarios/química , Antiprotozoarios/farmacocinética , Antiprotozoarios/toxicidad , Simulación por Computador , Relación Dosis-Respuesta a Droga , Humanos , Concentración 50 Inhibidora , Leishmania braziliensis/crecimiento & desarrollo , Modelos Biológicos , Modelos Químicos , Estructura Molecular , Pruebas de Sensibilidad Parasitaria , Células THP-1RESUMEN
Previous investigation of the potent antileishmanial properties of antitubercular 7-substituted 2-nitroimidazo[2,1-b][1,3]oxazines with biaryl side chains led to our development of a new clinical candidate for visceral leishmaniasis (DNDI-0690). Within a collaborative backup program, a racemic monoaryl lead (3) possessing comparable activity in mice but a greater hERG liability formed the starting point for our pursuit of efficacious second generation analogues having good solubility and safety. Asymmetric synthesis and appraisal of its enantiomers first established that chiral preferences for in vivo efficacy were species dependent and that neither form afforded a reduced hERG risk. However, in line with our findings in a structurally related series, less lipophilic heteroaryl ethers provided significant solubility enhancements (up to 16-fold) and concomitantly attenuated hERG inhibition. One promising pyridine derivative (49) displayed 100% oral bioavailability in mice and delivered a 96% parasite burden reduction when dosed at 50 mg/kg in a Leishmania donovani mouse model of visceral leishmaniasis.
Asunto(s)
Antiprotozoarios/síntesis química , Éter/síntesis química , Hidrocarburos Aromáticos/química , Leishmaniasis Visceral/tratamiento farmacológico , Oxazinas/química , Animales , Antiprotozoarios/administración & dosificación , Antiprotozoarios/farmacocinética , Cricetinae , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Éter/administración & dosificación , Éter/farmacocinética , Femenino , Humanos , Leishmania donovani/efectos de los fármacos , Masculino , Ratones , Pruebas de Sensibilidad Parasitaria , Piridinas/química , Solubilidad , Relación Estructura-ActividadRESUMEN
Tellurium compounds have been described as potential leishmanicides, bearing promising leishmanicidal and antimalarial effects. Therefore, the present study investigated the pharmacological potential of the organotellurane compound RF07 through preADMET parameters, such as absorption, distribution, metabolism and excretion. After studying the pharmacokinetic properties of RF07, studies were carried out on dogs naturally infected with visceral leishmaniasis after the administration of RF07, in order to assess pathophysiological parameters. Thus, dogs were divided into 4 groups with administration of daily intraperitoneal injections for 3 weeks (containing RF07 or placebo). During the trial, hematological parameters, renal and hepatic toxicity were evaluated. Serum urea, creatinine, alkaline phosphatase, transaminases (GOT and GPT), as well as hemogram results, were evaluated before the first administration and during the second and third weeks after the start of the treatment. In dogs with VL, RF07 improved liver damage, regulated GPT levels and significantly decreased leukocyte count, promoting its regularization. These phenomena occurred at the end of the third week of treatment. The administration of RF07 promoted a significant decrease in the average levels of GOT and GPT after the third week of treatment and did not significantly alter the hematological parameters. The application of RF07 in the treatment of visceral leishmaniasis suggests that it is an alternative to the disease, since the reversal of clinical signs in dogs with VL requires the use of 0.6â¯mg/kg.
Asunto(s)
Antiprotozoarios , Leishmaniasis Visceral , Compuestos Organometálicos , Compuestos de Espiro , Telurio , Alanina Transaminasa/sangre , Fosfatasa Alcalina/sangre , Animales , Antiprotozoarios/farmacocinética , Antiprotozoarios/farmacología , Antiprotozoarios/uso terapéutico , Aspartato Aminotransferasas/sangre , Recuento de Células Sanguíneas , Peso Corporal/efectos de los fármacos , Creatinina/sangre , Perros , Absorción Intestinal , Riñón/efectos de los fármacos , Riñón/patología , Leishmaniasis Visceral/sangre , Leishmaniasis Visceral/tratamiento farmacológico , Leishmaniasis Visceral/patología , Leishmaniasis Visceral/veterinaria , Hígado/efectos de los fármacos , Hígado/patología , Masculino , Modelos Biológicos , Compuestos Organometálicos/farmacocinética , Compuestos Organometálicos/farmacología , Compuestos Organometálicos/uso terapéutico , Compuestos de Espiro/farmacocinética , Compuestos de Espiro/farmacología , Compuestos de Espiro/uso terapéutico , Telurio/farmacocinética , Telurio/farmacología , Telurio/uso terapéutico , Urea/sangreRESUMEN
BACKGROUND: Leishmaniasis is a neglected tropical disease caused by protozoa of the genus Leishmania. Current treatments are restricted to a small number of drugs that display both severe side effects and a potential for parasites to develop resistance. A new N-(3,4-methylenedioxyphenyl)-N'- (2-phenethyl) thiourea compound (thiourea 1) has shown promising in vitro activity against Leishmania amazonensis with an IC50 of 54.14 µM for promastigotes and an IC50 of 70 µM for amastigotes. OBJECTIVE: To develop a formulation of thiourea 1 as an oral treatment for leishmaniasis, it was incorporated into Nanoparticles (NPs), a proven approach to provide long-acting drug delivery systems. METHODS: Poly (D,L-Lactic-co-Glycolic Acid) (PLGA) polymeric NPs containing thiourea 1 were obtained through a nanoprecipitation methodology associated with solvent evaporation. The NPs containing thiourea 1 were characterized for Encapsulation Efficiency (EE%), reaction yield (% w/w), surface charge, particle size and morphology by Transmission Electron Microscopy (TEM). RESULTS: NPs with thiourea 1 showed an improved in vitro leishmanicidal activity with a reduction in its cytotoxicity against macrophages (CC50>100 µg/mL) while preserving its IC50 against intracellular amastigotes (1.46 ± 0.09 µg/mL). This represents a parasite Selectivity Index (SI) of 68.49, which is a marked advancement from the reference drug pentamidine (SI = 30.14). CONCLUSION: The results suggest that the incorporation into NPs potentiated the therapeutic effect of thiourea 1, most likely by improving the selective delivery of the drug to the phagocytic cells that are targeted for infection by L. amazonensis. This work reinforces the importance of nanotechnology in the acquisition of new therapeutic alternatives for oral treatments.
Asunto(s)
Antiprotozoarios/administración & dosificación , Portadores de Fármacos/química , Leishmania mexicana/efectos de los fármacos , Leishmaniasis Cutánea/tratamiento farmacológico , Tiourea/administración & dosificación , Animales , Antiprotozoarios/farmacocinética , Antiprotozoarios/toxicidad , Modelos Animales de Enfermedad , Liberación de Fármacos , Humanos , Leishmaniasis Cutánea/parasitología , Macrófagos/parasitología , Ratones , Nanopartículas/química , Pruebas de Sensibilidad Parasitaria , Tamaño de la Partícula , Copolímero de Ácido Poliláctico-Ácido Poliglicólico/química , Cultivo Primario de Células , Tiourea/análogos & derivados , Tiourea/farmacocinética , Tiourea/toxicidad , Pruebas de Toxicidad AgudaRESUMEN
BACKGROUND: Ponazuril is used for the treatment of equine protozoal myeloencephalitis (EPM). Coadministration of ponazuril with oil could result in higher serum and cerebrospinal fluid (CSF) concentrations of ponazuril. HYPOTHESIS: Coadministration of corn oil will result in higher serum and CSF concentrations of ponazuril than when ponazuril is administered alone. ANIMALS: Ten resident university-owned adult horses of either sex and >2 years of age. METHODS: Cohort study. Ponazuril oral paste (5 mg/kg BW; ponazuril treatment group (PON); n = 5), or ponazuril oral paste (5 mg/kg BW; ponazuril and oil treatment group (PONOIL; n = 5) coadministered with 2 oz of corn oil q24h for 21 days. Horses were treated once daily, for 21 days. Blood was collected on days 0, 7, 14, and 21 before dosing. In addition, CSF was collected on days 1, 7, 14, and 21. The concentration of ponazuril was determined in serum and CSF and results compared using repeated measures ANOVA. RESULTS: Coadministration of ponazuril with 2 oz of corn oil resulted in higher concentrations of ponazuril in serum (at steady state) than that found in horses given ponazuril alone (6.2 ± 0.9 mg/L versus 4.5 ± 1.0 mg/L; P = .004) (mean ± 1 SD). Cerebrospinal fluid concentrations of ponazuril were also greater in horses that received ponazuril and oil (0.213 mg/L ± 0.04 versus 0.162 ± 0.04 mg/L) (P = .03). CONCLUSIONS AND CLINICAL IMPORTANCE: Results suggest that coadministration of corn oil with ponazuril might enhance the effectiveness of treatment with ponazuril.
Asunto(s)
Antiprotozoarios/farmacocinética , Aceite de Maíz/administración & dosificación , Triazinas/administración & dosificación , Triazinas/farmacocinética , Administración Oral , Animales , Antiprotozoarios/administración & dosificación , Antiprotozoarios/sangre , Antiprotozoarios/líquido cefalorraquídeo , Estudios de Cohortes , Femenino , Caballos , Masculino , Triazinas/sangre , Triazinas/líquido cefalorraquídeoRESUMEN
Leishmaniasis are a group of neglected infectious diseases caused by protozoa of the genus Leishmania with distinct presentations. The available leishmaniasis treatment options are either expensive and/or; cause adverse effects and some are ineffective for resistant Leishmania strains. Therefore, molecules derived from natural products as the monoterpene carvacrol, have attracted interest as promising anti-leishmania agents. However, the therapeutic use of carvacrol is limited due to its low aqueous solubility, rapid oxidation and volatilization. Thus, the development of nanostructured lipid carriers (NLCs) was proposed in the present study as a promising nanotechnology strategy to overcome these limitations and enable the use of carvacrol in leishmaniasis therapy. Carvacrol NLCs were obtained using a warm microemulsion method, and evaluated regarding the influence of lipid matrix and components concentration on the NLCs formation. NLCs were characterized by DSC and XRD as well. In addition, to the in vitro carvacrol release from NLCs, the in vitro cytotoxicity and leishmanicidal activity assays, and the in vivo pharmacokinetics evaluation of free and encapsulated carvacrol were performed. NLCs containing carvacrol were obtained successfully using a warm microemulsion dilution method. The NLCs formulation with the lowest particle size (98.42 ± 0.80 nm), narrowest size distribution (suitable for intravenous administration), and the highest encapsulation efficiency was produced by using beeswax as solid lipid (HLB=9) and 5% of lipids and surfactant. The in vitro release of carvacrol from NLCs was fitted to the Korsmeyer and Peppas, and Weibull models, demonstrating that the release mechanism is probably the Fickian diffusion type. Moreover, carvacrol encapsulation in NLCs provided a lower cytotoxicity in comparison to free carvacrol (p<0.05), increasing its in vitro leishmanicidal efficacy in the amastigote form. Finally, the in vivo pharmacokinetics of carvacrol after IV bolus administration suggests that this phenolic monoterpene undergoes enterohepatic circulation and therefore presented a long half-life (t1/2) and low clearance (Cl). In addition, C0, mean residence time (MRT) and Vdss of encapsulated carvacrol were higher than free carvacrol (p < 0.05), favoring a higher distribution of carvacrol in the target tissues. Thus, it is possible to conclude that the developed NLCs are a promising delivery system for leishmaniasis treatment.
Asunto(s)
Antiprotozoarios/administración & dosificación , Cimenos/administración & dosificación , Portadores de Fármacos/administración & dosificación , Leishmania/efectos de los fármacos , Nanoestructuras/administración & dosificación , Animales , Antiprotozoarios/sangre , Antiprotozoarios/química , Antiprotozoarios/farmacocinética , Supervivencia Celular/efectos de los fármacos , Cimenos/sangre , Cimenos/farmacocinética , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Liberación de Fármacos , Humanos , Leishmaniasis/tratamiento farmacológico , Lípidos/administración & dosificación , Lípidos/química , Lípidos/farmacocinética , Macrófagos Peritoneales/efectos de los fármacos , Masculino , Ratones Endogámicos BALB C , Nanoestructuras/química , Ratas Wistar , Células THP-1RESUMEN
A highly sensitive method was developed to quantitate the antileishmanial agent paromomycin in human plasma, with a lower limit of quantification of 5â¯ng/mL. Separation was achieved using an isocratic ion-pair ultra-high performance liquid chromatographic (UPLC) method with a minimal concentration of heptafluorobutyric acid, which was coupled through an electrospray ionization interface to a triple quadrupole - linear ion trap mass spectrometer for detection. The method was validated over a linear calibration range of 5 to 1000â¯ng/mL (r2≥0.997) with inter-assay accuracies and precisions within the internationally accepted criteria. Volumes of 50⯵L of human K2EDTA plasma were processed by using a simple protein precipitation method with 40⯵L 20 % trichloroacetic acid. A good performance was shown in terms of recovery (100 %), matrix effect (C.V.â¯≤â¯12.0 %) and carry-over (≤17.5 % of the lower limit of quantitation). Paromomycin spiked to human plasma samples was stable for at least 24â¯h at room temperature, 6â¯h at 35⯰C, and 104 days at -20⯰C. Paromomycin adsorbs to glass containers at low concentrations, and therefore acidic conditions were used throughout the assay, in combination with polypropylene tubes and autosampler vials. The assay was successfully applied in a pharmacokinetic study in visceral leishmaniasis patients from Eastern Africa.
Asunto(s)
Antiprotozoarios/sangre , Monitoreo de Drogas/métodos , Leishmaniasis Visceral/tratamiento farmacológico , Paromomicina/sangre , Adsorción , África Oriental , Antiprotozoarios/administración & dosificación , Antiprotozoarios/química , Antiprotozoarios/farmacocinética , Calibración , Cromatografía Líquida de Alta Presión/métodos , Cromatografía Líquida de Alta Presión/normas , Estabilidad de Medicamentos , Humanos , Inyecciones Intramusculares , Leishmaniasis Visceral/sangre , Límite de Detección , Paromomicina/administración & dosificación , Paromomicina/química , Paromomicina/farmacocinética , Estándares de Referencia , Reproducibilidad de los Resultados , Espectrometría de Masas en Tándem/métodos , Espectrometría de Masas en Tándem/normas , Ácido Tricloroacético/químicaRESUMEN
The present study aims to optimize and evaluate amphotericin B (AmB) and miltefosine (MTF) co-loaded second generation ultra-deformable liposomes (SGUDLs) for the topical treatment of cutaneous leishmaniasis (CL). The development of an effective topical drug formulation against CL is desirable because of its non-invasive nature, which may potentially enhance the patient adherence and treatment accessibility. AmB-MTF co-loaded SGUDLs were prepared and characterized for size, entrapment efficiency (EE) and elasticity. The optimized formulation was then subjected to ex-vivo permeation studies in addition to cytotoxicity and anti-leishmanial assays. The co-loaded SGUDLs had an average size of 139.7 ± 1.7 nm and high EE of 77.8 ± 3.9% with respect to AmB. The ex-vivo permeation of co-loaded SGUDLs exhibited 6.15-fold higher permeation of AmB. A synergistic interaction was observed between AmB and MTF, and anti-leishmanial activity of co-loaded SGUDLs against amastigotes of Lesihmania mexicana indicated 8.62 and 6.12-fold lower IC50 values of AmB and MTF as compared to plain drug solutions, respectively. The results of the in-vivo study displayed a significant reduction in the parasitic burden in an infected BALB/c experimental model of CL. In conclusion, AmB-MTF co-loaded SGUDLs could be an effective topical treatment option against CL.