RESUMEN
Schistosomiasis is a neglected zoonotic parasitic disease. Currently, praziquantel is the drug of choice for the treatment of schistosomiasis, and is the only effective chemical for treatment of schistosomiasis japonica. Since its introduction in the 1970s, praziquantel has been used for large-scale chemotherapy of schistosomiasis for over 40 years. However, there have been reports pertaining to the resistance to praziquantel in schistosomes. Therefore, development of novel antischistosomal agents as alternatives of praziquantel, is of great need. Histone deacetylases and histone acetyltransferases have been recently reported to play critical roles in the growth, development and reproduction of schistosomes, and are considered as potential drug targets for the treatment of schistosomiasis. This review summarizes the latest advances of histone deacetylase and histone acetyltransferase inhibitors in the research on antischistosomal drugs, so as to provide insights into research and development of novelantischistosomal agents.
Asunto(s)
Histona Acetiltransferasas , Inhibidores de Histona Desacetilasas , Histona Desacetilasas , Animales , Inhibidores de Histona Desacetilasas/farmacología , Histona Acetiltransferasas/antagonistas & inhibidores , Humanos , Histona Desacetilasas/metabolismo , Schistosoma/efectos de los fármacos , Schistosoma/enzimología , Schistosoma/fisiología , Esquistosomiasis/tratamiento farmacológico , Esquistosomicidas/farmacología , Esquistosomicidas/uso terapéuticoRESUMEN
The burden of human schistosomiasis, a known but neglected tropical disease in Sub-Saharan Africa, has been worrisome in recent years. It is becoming increasingly difficult to tackle schistosomiasis with praziquantel, a drug known to be effective against all Schistosoma species, due to reports of reduced efficacy and resistance. Therefore, this study seeks to investigate the antischistosomal potential of phytochemicals from Azadirachta indica against proteins that have been implicated as druggable targets for the treatment of schistosomiasis using computational techniques. In this study, sixty-three (63) previously isolated and characterized phytochemicals from A. indica were identified from the literature and retrieved from the PubChem database. In silico screening was conducted to assess the inhibitory potential of these phytochemicals against three receptors (Schistosoma mansoni Thioredoxin glutathione reductase, dihydroorotate dehydrogenase, and Arginase) that may serve as therapeutic targets for schistosomiasis treatment. Molecular docking, ADMET prediction, ligand interaction, MMGBSA, and molecular dynamics simulation of the hit compounds were conducted using the Schrodinger molecular drug discovery suite. The results show that Andrographolide possesses a satisfactory pharmacokinetic profile, does not violate the Lipinski rule of five, binds with favourable affinity with the receptors, and interacts with key amino acids at the active site. Importantly, its interaction with dihydroorotate dehydrogenase, an enzyme responsible for the catalysis of the de novo pyrimidine nucleotide biosynthetic pathway rate-limiting step, shows a glide score and MMGBSA of -10.19 and -45.75 Kcal/mol, respectively. In addition, the MD simulation shows its stability at the active site of the receptor. Overall, this study revealed that Andrographolide from Azadirachta indica could serve as a potential lead compound for the development of an anti-schistosomal drug.
Asunto(s)
Azadirachta , Dihidroorotato Deshidrogenasa , Simulación del Acoplamiento Molecular , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH , Esquistosomiasis , Azadirachta/química , Animales , Esquistosomiasis/tratamiento farmacológico , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH/antagonistas & inhibidores , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH/metabolismo , Humanos , Fitoquímicos/farmacología , Fitoquímicos/química , Simulación de Dinámica Molecular , Schistosoma mansoni/efectos de los fármacos , Schistosoma mansoni/enzimología , NADH NADPH Oxidorreductasas/antagonistas & inhibidores , NADH NADPH Oxidorreductasas/metabolismo , Extractos Vegetales/química , Extractos Vegetales/farmacología , Simulación por Computador , Esquistosomicidas/farmacología , Esquistosomicidas/química , Esquistosomicidas/uso terapéutico , Complejos Multienzimáticos/antagonistas & inhibidores , Complejos Multienzimáticos/metabolismo , Praziquantel/farmacología , Praziquantel/química , Praziquantel/uso terapéuticoRESUMEN
Schistosomiasis, caused by a parasitic blood fluke of the genus Schistosoma, is a global health problem for which new chemotherapeutic options are needed. We explored the scaffold of gallinamide A, a natural peptidic metabolite of marine cyanobacteria that has previously been shown to inhibit cathepsin L-type proteases. We screened a library of 19 synthetic gallinamide A analogs and identified nanomolar inhibitors of the cathepsin B-type protease SmCB1, which is a drug target for the treatment of schistosomiasis mansoni. Against cultured S. mansoni schistosomula and adult worms, many of the gallinamides generated a range of deleterious phenotypic responses. Imaging with a fluorescent-activity-based probe derived from gallinamide A demonstrated that SmCB1 is the primary target for gallinamides in the parasite. Furthermore, we solved the high-resolution crystal structures of SmCB1 in complex with gallinamide A and its two analogs and describe the acrylamide covalent warhead and binding mode in the active site. Quantum chemical calculations evaluated the contribution of individual positions in the peptidomimetic scaffold to the inhibition of the target and demonstrated the importance of the P1' and P2 positions. Our study introduces gallinamides as a powerful chemotype that can be exploited for the development of novel antischistosomal chemotherapeutics.
Asunto(s)
Catepsina B , Schistosoma mansoni , Catepsina B/antagonistas & inhibidores , Catepsina B/metabolismo , Animales , Schistosoma mansoni/enzimología , Schistosoma mansoni/efectos de los fármacos , Cristalografía por Rayos X , Esquistosomicidas/farmacología , Esquistosomicidas/química , Unión Proteica , Modelos MolecularesRESUMEN
Schistosomiasis is a neglected tropical disease associated with considerable morbidity. Praziquantel (PZQ) is effective against adult schistosomes, yet, it has little effect on juvenile stages, and PZQ resistance is emerging. Adopting the drug repurposing strategy as well as assuming enhancing the efficacy and lessening the doses and side effects, the present study aimed to investigate the in vivo therapeutic efficacy of the widely used antiarrhythmic, amiodarone, and diuretic, spironolactone, and combinations of them compared to PZQ. Mice were infected by Schistosoma mansoni "S. mansoni" cercariae (Egyptian strain), then they were divided into two major groups: Early- [3 weeks post-infection (wpi)] and late- [6 wpi] treated. Each group was subdivided into seven subgroups: positive control, PZQ, amiodarone, spironolactone, PZQ combined with amiodarone, PZQ combined with spironolactone, and amiodarone combined with spironolactone-treated groups. Among the early-treated groups, spironolactone had the best therapeutic impact indicated by a 69.4% reduction of total worm burden (TWB), 38.6% and 48.4% reduction of liver and intestine egg load, and a significant reduction of liver granuloma number by 49%. Whereas, among the late-treated groups, amiodarone combined with PZQ was superior to PZQ alone evidenced by 96.1% reduction of TWB with the total disappearance of female and copula in the liver and intestine, 53.1% and 84.9% reduction of liver and intestine egg load, and a significant reduction of liver granuloma number by 67.6%. Comparatively, spironolactone was superior to PZQ and amiodarone in the early treatment phase targeting immature stages, while amiodarone had a more potent effect when combined with PZQ in the late treatment phase targeting mature schistosomes.
Asunto(s)
Amiodarona , Modelos Animales de Enfermedad , Praziquantel , Schistosoma mansoni , Esquistosomiasis mansoni , Animales , Esquistosomiasis mansoni/tratamiento farmacológico , Esquistosomiasis mansoni/parasitología , Ratones , Schistosoma mansoni/efectos de los fármacos , Praziquantel/uso terapéutico , Praziquantel/farmacología , Amiodarona/uso terapéutico , Amiodarona/farmacología , Femenino , Espironolactona/uso terapéutico , Espironolactona/farmacología , Esquistosomicidas/uso terapéutico , Esquistosomicidas/farmacología , Masculino , Antihelmínticos/uso terapéutico , Antihelmínticos/farmacología , Resultado del Tratamiento , Quimioterapia Combinada , Hígado/parasitologíaRESUMEN
Schistosomiasis caused by Schistosoma spp. is a disease that causes a considerable health burden to millions of people worldwide. The limited availability of effective drugs on the market and the increased risk of resistance development due to extensive usage, highlight the urgent need for new antischistosomal drugs. Recent studies have shown that robenidine derivatives, containing an aminoguanidine core, exhibit promising activities against Plasmodium falciparum, motivating further investigation into their efficacy against Schistosoma mansoni, due to their similar habitat and the resulting related cellular mechanisms like the heme detoxification pathway. The conducted phenotypic screening of robenidine and 80 derivatives against newly transformed schistosomula and adult Schistosoma mansoni yielded 11 candidates with low EC50 values for newly transformed schistosomula (1.12-4.63 µM) and adults (2.78-9.47 µM). The structure-activity relationship revealed that electron-withdrawing groups at the phenyl moiety, as well as the presence of methyl groups adjacent to the guanidine moiety, enhanced the activity of derivatives against both stages of Schistosoma mansoni. The two compounds 2,2'-Bis[(3-cyano-4-fluorophenyl)methylene] carbonimidic Dihydrazide Hydrochloride (1) and 2,2'-Bis[(4-difluoromethoxyphenyl) ethylidene] carbonimidic Dihydrazide Hydrochloride (19), were selected for an in vivo study in Schistosoma mansoni-infected mice based on their potency, cytotoxicity, pharmacokinetic-, and physicochemical properties, but failed to reduce the worm burden significantly (worm burden reduction <20%). Thus, robenidine derivatives require further refinements to obtain higher antischistosomal specificity and in vivo activity.
Asunto(s)
Guanidinas , Schistosoma mansoni , Esquistosomiasis mansoni , Esquistosomicidas , Animales , Schistosoma mansoni/efectos de los fármacos , Ratones , Esquistosomicidas/farmacología , Esquistosomiasis mansoni/tratamiento farmacológico , Esquistosomiasis mansoni/parasitología , Relación Estructura-Actividad , Guanidinas/farmacología , Guanidinas/química , Femenino , MasculinoRESUMEN
We have evaluated eight p-coumaric acid prenylated derivatives inâ vitro for their antileishmanial activity against Leishmania amazonensis promastigotes and their antischistosomal activity against Schistosoma mansoni adult worms. Compound 7 ((E)-3,4-diprenyl-4-isoprenyloxycinnamic alcohol) was the most active against L. amazonensis (IC50=45.92â µM) and S. mansoni (IC50=64.25â µM). Data indicated that the number of prenyl groups, the presence of hydroxyl at C9, and a single bond between C7 and C8 are important structural features for the antileishmanial activity of p-coumaric acid prenylated derivatives.
Asunto(s)
Antiprotozoarios , Ácidos Cumáricos , Leishmania , Pruebas de Sensibilidad Parasitaria , Schistosoma mansoni , Animales , Schistosoma mansoni/efectos de los fármacos , Ácidos Cumáricos/farmacología , Ácidos Cumáricos/química , Leishmania/efectos de los fármacos , Antiprotozoarios/farmacología , Antiprotozoarios/química , Antiprotozoarios/síntesis química , Relación Estructura-Actividad , Prenilación , Propionatos/farmacología , Propionatos/química , Estructura Molecular , Esquistosomicidas/farmacología , Esquistosomicidas/química , Esquistosomicidas/síntesis química , Relación Dosis-Respuesta a DrogaRESUMEN
Among all the neglected diseases, schistosomiasis is considered the second most important parasitic infection after malaria. Praziquantel is the most widely used drug for this disease, but its exclusive use may result in the development of drug-resistant schistosomiasis. To increase the control of the disease, new drugs have been developed as alternative treatments, among them 2-(-5-bromo-1-h-indole-3-yl-methylene)-N-(naphthalene-1-ylhydrazine-carbothiamide (LQIT/LT-50), which showed promising schistosomicidal activity in nonclinical studies. However, LQIT/LT-50 presents low solubility in water, resulting in reduced bioavailability. To overcome this solubility problem, the present study aimed to develop LQIT/LT-50 solid dispersions for the treatment of schistosomiasis. Solid dispersions were prepared through the solvent method using Soluplus©, polyethylene glycol (PEG) or polyvinylpyrrolidone (PVP K-30) as hydrophilic carriers. The formulations with the best results in the compatibility tests, aqueous solubility and preliminary stability studies have undergone solubility tests and physicochemical characterizations by Fourier-transform infrared spectroscopy (FTIR), x-ray diffractometry (XRD), exploratory differential calorimetry (DSC), thermogravimetry (TG) and Raman spectroscopy. Finally, the schistosomicidal activity was evaluated in vitro. The phycochemical analyzes showed that when using PVP K-30, there was an interaction between the PVP K-30 and LQIT/LT-50, proving the successful development of the solid dispersion. Furthermore, an increase in the solubility of the new system was observed (LQIT/LT-50:PVP K-30) in addition to the improvement in the in vitro shistosomidal activity at 1:4 (w/w) molar ratio (i.e., 20% drug loading) when compared to LQIT/LT-50 alone. The development of the LQIT/LT-50:PVP K-30 1:4 solid dispersion is encouraging for the future development of new pharmaceutical solid formulations, aiming the schistosomicidal treatment.
Asunto(s)
Esquistosomiasis , Esquistosomicidas , Humanos , Esquistosomicidas/farmacología , Química Farmacéutica/métodos , Povidona/química , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Naftalenos , Agua , Indoles/farmacología , Difracción de Rayos X , Portadores de Fármacos/químicaRESUMEN
BACKGROUND: CLA (conjugated linoleic acid)-mediated activation of the schistosome tegument-associated sphingomyelinase and consequent disruption of the outer membrane might allow host antibodies to access the apical membrane antigens. Here, we investigated a novel approach to enhance specific antibody delivery to concealed surface membrane antigens of Schistosoma mansoni utilising antibody-conjugated-CLA nanomicelle technology. METHODOLOGY/PRINCIPAL FINDINGS: We invented and characterised an amphiphilic CLA-loaded whey protein co-polymer (CLA-W) as an IV injectable protein nanocarrier. Rabbit anti-Schistosoma mansoni infection (anti-SmI) and anti-Schistosoma mansoni alkaline phosphatase specific IgG antibodies were purified from rabbit sera and conjugated to the surface of CLA-W co-polymer to form antibody-conjugated-CLA-W nanomicelles (Ab-CLA-W). We investigated the schistosomicidal effects of CLA-W and Ab-CLA-W in a mouse model of Schistosoma mansoni against early and late stages of infection. Results showed that conjugation of nanomicelles with antibodies, namely anti-SmI, significantly enhanced the micelles' schistosomicidal and anti-pathology activities at both the schistosomula and adult worm stages of the infection resulting in 64.6%-89.9% reductions in worm number; 72.5-94% and 66.4-85.2% reductions in hepatic eggs and granulomas, respectively. Treatment induced overall improvement in liver histopathology, reducing granuloma size and fibrosis and significantly affecting egg viability. Indirect immunofluorescence confirmed CLA-W-mediated antigen exposure on the worm surface. Electron microscopy revealed extensive ultrastructural damage in worm tegument induced by anti-SmI-CLA-W. CONCLUSION/SIGNIFICANCE: The novel antibody-targeted nano-sized CLA delivery system offers great promise for treatment of Schistosoma mansoni infection and control of its transmission. Our in vivo observations confirm an immune-mediated enhanced effect of the schistosomicidal action of CLA and hints at the prospect of nanotechnology-based immunotherapy, not only for schistosomiasis, but also for other parasitic infections in which chemotherapy has been shown to be immune-dependent. The results propose that the immunodominant reactivity of the anti-SmI serum, Schistosoma mansoni fructose biphosphate aldolase, SmFBPA, merits serious attention as a therapeutic and vaccine candidate.
Asunto(s)
Esquistosomiasis mansoni , Esquistosomiasis , Esquistosomicidas , Ratones , Animales , Conejos , Esquistosomiasis mansoni/parasitología , Schistosoma mansoni , Esquistosomiasis/tratamiento farmacológico , Anticuerpos Antihelmínticos , Esquistosomicidas/farmacología , Polímeros/farmacología , Polímeros/uso terapéutico , Antígenos HelmínticosRESUMEN
Background: The impact of schistosomiasis, which affects over 230 million people, emphasizes the urgency of developing new antischistosomal drugs. Artificial intelligence is vital in accelerating the drug discovery process. Methodology & results: We developed classification and regression machine learning models to predict the schistosomicidal activity of compounds not experimentally tested. The prioritized compounds were tested on schistosomula and adult stages of Schistosoma mansoni. Four compounds demonstrated significant activity against schistosomula, with 50% effective concentration values ranging from 9.8 to 32.5 µM, while exhibiting no toxicity in animal and human cell lines. Conclusion: These findings represent a significant step forward in the discovery of antischistosomal drugs. Further optimization of these active compounds can pave the way for their progression into preclinical studies.
Asunto(s)
Esquistosomiasis , Esquistosomicidas , Animales , Humanos , Schistosoma mansoni , Inteligencia Artificial , Esquistosomicidas/farmacología , Esquistosomiasis/tratamiento farmacológico , Descubrimiento de DrogasRESUMEN
Schistosomiasis, caused by Schistosoma mansoni Sambon, 1907, is a severe and widely distributed parasitic disease, affecting about 200 million people worldwide. The disease is recognized by elevated mortality rates, especially among those living in areas of poor sanitation. Currently, the chemotherapeutic treatment is solely based on using the praziquantel drug. Therefore, there is a need for the discovery of new medicines for the treatment of this parasitosis. Thus, this work aimed to evaluate the schistosomicidal activity of ethanolic crude extracts from the branches, leaves, flowers, and fruits of Handroanthus impetiginosus (Mart ex DC.) Masttos and characterize its metabolic profile by UPLC-ESI-QTOF analysis. Evaluation of plant extract on S. mansoni was carried out in adult worms in vitro, in which the mortality rate was quantified, and the damages in the tegument of the worms were monitored. All extracts induced changes in the viability of adult males of S. mansoni, causing the death of the parasites, which was directly dependent of the concentration.
Asunto(s)
Bignoniaceae , Esquistosomicidas , Tabebuia , Humanos , Masculino , Esquistosomicidas/farmacología , Esquistosomicidas/uso terapéutico , Frutas , Etanol , Flores , Extractos Vegetales/farmacología , Extractos Vegetales/uso terapéuticoRESUMEN
The chemical classes of semicarbazones, thiosemicarbazones, and hydrazones are present in various compounds, each demonstrating diverse biological activities. Extensive studies have revealed their potential as schistosomicidal agents. Thiosemicarbazones, in particular, have shown inhibitory effects on Schistosoma mansoni's cathepsin B1 enzyme (SmCB1), which plays a crucial role in hemoglobin degradation within the worm's gut and its nutrition processes. Consequently, SmCB1 has emerged as a promising target for novel schistosomiasis therapies. Moreover, chloroquinoline exhibits characteristics in its aromatic structure that hold promise for developing SmCB1 inhibitors, along with its interaction with hemoglobin's heme group, potentially synergizing against the parasite's gut. In this context, we report the synthesis of 22 hybrid analogs combining hydrazones and quinolines, evaluated against S. mansoni. Five of these hybrids demonstrated schistosomicidal activity in vitro, with GPQF-8Q10 being the most effective, causing worm mortality within 24 h at a concentration of 25 µM. GPQF-8Q8 proved to be the most promising in vivo, significantly reducing egg presence in feces (by 52.8%) and immature eggs in intestines (by 45.8%). These compounds exhibited low cytotoxicity in Vero cells and an in in vivo animal model (Caenorhabditis elegans), indicating a favorable selectivity index. This suggests their potential for the development of new schistosomiasis therapies. Further studies are needed to uncover specific target mechanisms, but these findings offer a promising starting point.
Asunto(s)
Esquistosomiasis mansoni , Esquistosomiasis , Esquistosomicidas , Tiosemicarbazonas , Animales , Chlorocebus aethiops , Schistosoma mansoni , Células Vero , Esquistosomicidas/farmacología , Tiosemicarbazonas/farmacología , Hidrazonas/farmacología , Hemoglobinas/farmacología , Esquistosomiasis mansoni/tratamiento farmacológicoRESUMEN
BACKGROUND: Praziquantel (PZQ) has been the first line antischistosomal drug for all species of Schistosoma, and the only available drug for schistosomiasis japonica, without any alternative drugs since the 1980s. However, PZQ cannot prevent reinfection, and cannot cure schistosomiasis thoroughly because of its poor activity against juvenile schistosomes. In addition, reliance on a single drug is extremely dangerous, the development and spread of resistance to PZQ is becoming a great concern. Therefore, development of novel drug candidates for treatment and control of schistosomiasis is urgently needed. METHODOLOGYS/PRINCIPAL FINDINGS: One of the PZQ derivative christened P96 with the substitution of cyclohexyl by cyclopentyl was synthesized by School of Pharmaceutical Sciences of Shandong University. We investigated the in vitro and in vivo activities of P96 against different developmental stages of S. japonicum. Parasitological studies and scanning electron microscopy were used to study the primary action characteristics of P96 in vitro. Both mouse and rabbit models were employed to evaluate schistosomicidal efficacy of P96 in vivo. Besides calculation of worm reduction rate and egg reduction rate, quantitative real-time PCR was used to evaluate the in vivo antischistosomal activity of P96 at molecular level. In vitro, after 24h exposure, P96 demonstrated the highest activities against both juvenile and adult worm of S. japonicum in comparison to PZQ. The antischistosomal efficacy was concentration-dependent, with P96 at 50µM demonstrating the most evident schistosomicidal effect. Scanning electron microscopy demonstrated that P96 caused more severe damages to schistosomula and adult worm tegument compared to PZQ. In vivo, our results showed that P96 was effective against S. japonicum at all developmental stages. Notably, its efficacy against young stage worms was significantly improved compared to PZQ. Moreover, P96 retained the high activity comparable to PZQ against the adult worm of S. japonicum. CONCLUSIONS: P96 is a promising drug candidate for chemotherapy of schistosomiasis japonica, which has broad spectrum of action against various developmental stage, potentially addressing the deficiency of PZQ. It might be promoted as a drug candidate for use either alone or in combination with PZQ for the treatment of schistosomiasis.
Asunto(s)
Praziquantel , Esquistosomiasis Japónica , Esquistosomicidas , Animales , Ratones , Conejos , Microscopía Electrónica de Rastreo , Praziquantel/análogos & derivados , Praziquantel/farmacología , Schistosoma japonicum/efectos de los fármacos , Esquistosomiasis Japónica/tratamiento farmacológico , Esquistosomicidas/farmacologíaRESUMEN
Malaria and schistosomiasis are two of the neglected tropical diseases that persistently wreak havoc worldwide. Although many antimalarial drugs such as chloroquine are readily available, the emergence of drug resistance necessitates the development of new therapies to combat this disease. Conversely, Praziquantel (PZQ) remains the sole effective drug against schistosomiasis, but its extensive use raises concerns about the potential for drug resistance to develop. In this project, the concept of molecular hybridization was used as a strategy to design the synthesis of new molecular hybrids with potential antimalarial and antischistosomal activity. A total of seventeen molecular hybrids and two PZQ analogues were prepared by coupling 6-alkylpraziquanamines with cinnamic acids and cyclohexane carboxylic acid, respectively. The synthesised compounds were evaluated for their antimalarial and antischistosomal activity; while all of the above compounds were inactive against Plasmodium falciparum (IC50 > 6 µM), many were active against schistosomiasis with four particular compounds exhibiting up to 100% activity against newly transformed schistosomula and adult worms at 50 µM. Compared to PZQ, the reference drug, the activity of which is 91.7% at 1 µM, one particular molecular hybrid, compound 32, which bears a para-isopropyl group on the cinnamic acid moiety, exhibited a notable activity at 10 µM (78.2% activity). This compound has emerged as the front runner candidate that might, after further optimization, hold promise as a potential lead compound in the fight against schistosomiasis.
Asunto(s)
Antimaláricos , Esquistosomiasis , Esquistosomicidas , Animales , Praziquantel/farmacología , Praziquantel/uso terapéutico , Antimaláricos/farmacología , Antimaláricos/uso terapéutico , Schistosoma mansoni , Esquistosomicidas/farmacología , Esquistosomicidas/uso terapéutico , Esquistosomiasis/tratamiento farmacológicoRESUMEN
Schistosomiasis is a parasitic disease that afflicts approximately 250 million people worldwide. There is an urgent demand for new antiparasitic agents because praziquantel, the only drug available for the treatment of schistosomiasis, is not universally effective and may derail current progress toward the WHO goal of eliminating this disease as a public health problem by 2030. Nifuroxazide (NFZ), an oral nitrofuran antibiotic, has recently been explored to be repurposed for parasitic diseases. Here, in vitro, in vivo, and in silico studies were conducted to evaluate the activity of NFZ on Schistosoma mansoni. The in vitro study showed significant antiparasitic activity, with 50% effective concentration (EC50) and 90% effective concentration (EC90) values of 8.2 to 10.8 and 13.7 to 19.3 µM, respectively. NFZ also affected worm pairing and egg production and induced severe damage to the tegument of schistosomes. In vivo, a single oral dose of NFZ (400 mg/kg of body weight) to mice harboring either prepatent or patent S. mansoni infection significantly reduced the total worm burden (~40%). In patent infection, NFZ achieved a high reduction in the number of eggs (~80%), but the drug caused a low reduction in the egg burden of animals with prepatent infection. Finally, results from in silico target fishing methods predicted that serine/threonine kinases could be one of the potential targets for NFZ in S. mansoni. Overall, the present study revealed that NFZ possesses antischistosomal properties, mainly in terms of egg burden reduction in animals with patent S. mansoni infection. IMPORTANCE The increasing recognition of the burden imposed by helminthiasis, associated with the limited therapeutic arsenal, has led to initiatives and strategies to research and develop new drugs for the treatment of schistosomiasis. One of these strategies is drug repurposing, which considers low-risk compounds with potentially reduced costs and shorter time for development. In this study, nifuroxazide (NFZ) was evaluated for its anti-Schistosoma mansoni potential through in vitro, in vivo, and in silico studies. In vitro, NFZ affected worm pairing and egg production and induced severe damage to the tegument of schistosomes. In vivo, a single oral dose of NFZ (400 mg/kg) to mice harboring either prepatent or patent S. mansoni infection significantly reduced the total worm burden and egg production. In silico investigations have identified serine/threonine kinases as a molecular target for NFZ. Collectively, these results implied that NFZ might be a potential therapeutic candidate for the treatment of schistosomiasis.
Asunto(s)
Nitrofuranos , Esquistosomiasis mansoni , Esquistosomiasis , Esquistosomicidas , Animales , Ratones , Esquistosomicidas/farmacología , Esquistosomicidas/uso terapéutico , Esquistosomiasis mansoni/tratamiento farmacológico , Esquistosomiasis mansoni/parasitología , Schistosoma mansoni , Nitrofuranos/farmacología , Nitrofuranos/uso terapéutico , Treonina/farmacología , Treonina/uso terapéutico , SerinaRESUMEN
Schistosomiasis affects about 260â million people worldwide and the search for new schistosomicidal compounds is urgent. In this study we evaluated the inâ vitro effect of barbatic acid against schistosomulae and young worms of Schistosoma mansoni. The barbatic acid was evaluated through the bioassay of motility and mortality, cellular viability and ultrastructural analysis of juvenile stages through Scanning Electron Microscopy. Barbatic acid showed a schistosomicidal effect against schistosomulae and young worms of S. mansoni after 3â h of exposure. At the end of 24â h, barbatic acid showed 100 %, 89.5 %, 52 % and 28.5 % of lethality for schistosomulae at the concentrations of 200, 100, 50 and 25â µM, respectively. For young worms, barbatic acid showed 100 % and 31.7 % of lethality at the concentrations of 200 and 100â µM, respectively. Motility changes were observed at all sublethal concentrations. There was a significant reduction in the viability of young worms after exposure to barbatic acid at 50, 100 and 200â µM. Extensive damage to the schistosomulae and young worm's tegument, was observed from 50â µM. This report provides data showing the schistosomicidal effect of barbatic acid on schistosomulae and young worms of S.â mansoni, causing death, motility changes and ultrastructural damage to worms.
Asunto(s)
Antihelmínticos , Ácidos Ftálicos , Esquistosomicidas , Animales , Schistosoma mansoni , Antihelmínticos/farmacología , Ácidos Ftálicos/farmacología , Esquistosomicidas/farmacología , Microscopía Electrónica de RastreoRESUMEN
Only praziquantel is available for treating schistosomiasis, a disease affecting more than 200 million people. Praziquantel-resistant worms have been selected for in the lab and low cure rates from mass drug administration programs suggest that resistance is evolving in the field. Thioredoxin glutathione reductase (TGR) is essential for schistosome survival and a validated drug target. TGR inhibitors identified to date are irreversible and/or covalent inhibitors with unacceptable off-target effects. In this work, we identify noncovalent TGR inhibitors with efficacy against schistosome infections in mice, meeting the criteria for lead progression indicated by WHO. Comparisons with previous in vivo studies with praziquantel suggests that these inhibitors outperform the drug of choice for schistosomiasis against juvenile worms.
Asunto(s)
Esquistosomiasis , Esquistosomicidas , Animales , Ratones , Esquistosomicidas/farmacología , Esquistosomicidas/uso terapéutico , Praziquantel/farmacología , Schistosoma , NADH NADPH Oxidorreductasas/farmacología , NADH NADPH Oxidorreductasas/uso terapéutico , Schistosoma mansoniRESUMEN
The present work aimed to carry out in vitro biological assays of thiazole compounds against adult worms of Schistosoma mansoni, as well as the in silico determination of pharmacokinetic parameters to predict the oral bioavailability of these compounds. In addition to presenting moderate to low cytotoxicity against mammalian cells, thiazole compounds are not considered hemolytic. All compounds were initially tested at concentrations ranging from 200 to 6.25 µM against adult worms of S. mansoni parasites. The results showed the best activity of PBT2 and PBT5 at a concentration of 200 µM, which caused 100% mortality after 3 h of incubation. While at 6 h of exposure, 100% mortality was observed at the concentration of 100 µM. Subsequent studies with these same compounds allowed classifying PBT5, PBT2, PBT6 and PBT3 compounds, which were considered active and PBT1 and PBT4 compounds, which were considered inactive. In the ultrastructural analysis the compounds PBT2 and PBT5 (200 µM) promoted integumentary changes with exposure of the muscles, formation of integumentary blisters, integuments with abnormal morphology and destruction of tubercles and spicules. Therefore, the compounds PBT2 and PBT5 are promising antiparasitics against S. mansoni.
Asunto(s)
Esquistosomiasis mansoni , Esquistosomicidas , Animales , Schistosoma mansoni/ultraestructura , Tiazoles/farmacología , Tiazoles/uso terapéutico , Esquistosomicidas/farmacología , Esquistosomicidas/uso terapéutico , Antiparasitarios/uso terapéutico , Esquistosomiasis mansoni/tratamiento farmacológico , MamíferosRESUMEN
Schistosomiasis is a neglected tropical parasitic disease that affects millions of people, being the second most prevalent parasitic disease worldwide. The current treatment has limited effectiveness, drug-resistant strains, and is not effective in different stages of the disease. This study investigated the antischistosomal activity of biogenic silver nanoparticles (Bio-AgNp) against Schistosoma mansoni. Bio-AgNp presented direct schistosomicidal activity on newly transformed schistosomula causing plasma membrane permeabilization. In S. mansoni adult worms, reduced the viability and affected the motility, increasing oxidative stress parameters, and inducing plasma membrane permeabilization, loss of mitochondrial membrane potential, lipid bodies accumulation, and autophagic vacuoles formation. During the experimental schistosomiasis mansoni model, Bio AgNp restored body weight, reduced hepatosplenomegaly, and decrease the number of eggs and worms in feces and liver tissue. The treatment also ameliorates liver damage and reduces macrophage and neutrophil infiltrates. A reduction in count and size was evaluated in the granulomas, as well as a change to an exudative-proliferative phase, with a local increase of IFN-γ. Together our results showed that Bio-AgNp is a promising therapeutic candidate for studies of new therapeutic strategies against schistosomiasis.
Asunto(s)
Nanopartículas del Metal , Esquistosomiasis mansoni , Esquistosomicidas , Animales , Humanos , Esquistosomiasis mansoni/tratamiento farmacológico , Esquistosomicidas/farmacología , Esquistosomicidas/uso terapéutico , Plata/farmacología , Schistosoma mansoniRESUMEN
Schistosomiasis is an endemic disease in Brazil. It is important to broaden the treatment options to control and containment of the disease. Thiazolidine derivatives appear as important alternatives to treatment. In vitro studies have demonstrated excellent schistosomiasis activity for LPSF/GQ-238. The molecule, however, has poorly water-soluble. This study focused on increasing the aqueous solubility of LPSF/GQ-238 by obtaining solid dispersions. Were prepared by the solvent techniques, using Soluplus®, Polyethylene glycol (PEG), and Polyvinylpyrrolidone (PVP-K30) as carriers. Solubility tests, Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), Exploratory Differential Calorimetry (DSC), and Raman Spectroscopy characterized these new intermediate products. The solubility tests showed that the higher the proportion of polymer used in the preparation of the dispersion, the greater the solubility presented. The observation of the morphology by SEM analysis, elucidated, that the new chemical entity (NCE) has a characteristic crystalline structure. The folding of this structure by the polymer was observed in all analyzed dispersions, thus demonstrating the amorphous state of the product. The scales observed in the structures of the dispersions demonstrate the successive wrinkles that occurred. The greater the proportion of the polymer, the greater the number of folds that occurred, which may explain the greater solubility observed in these preparations. The X-ray diffraction profile of the NCE reveals the presence of intense peaks, presenting a crystalline pattern. The polymer, on the other hand, shows amorphous nature, evidenced by the absence of peaks. All the analyzed dispersions did not present the characteristic peaks of the NCE, evidencing the amorphous behavior of the products. The thermal degradation profile of the NCE presents a characteristic crystalline structure endothermic peak. This peak was not observed in any of the obtained dispersions, evidencing the obtaining of a new solid state. Raman spectroscopy showed that peaks in the range 200-400 (cm-1) by NCE were lost when compared to all analyzed dispersions, showing a slight change in the structure of the molecule when dispersed, probably due to the formation of hydrogen bonds with the polymer. The in vitro study showed a significant improvement in the activity of the NCE against the adult worm and to the schistosomulae. It was possible to observe that the obtained solid dispersions were physicochemically and biologically viable for schistosomicidal treatment due to the increase of solubility of the molecule.
Asunto(s)
Esquistosomiasis , Esquistosomicidas , Humanos , Tiazolidinas , Esquistosomicidas/farmacología , Espectroscopía Infrarroja por Transformada de Fourier , Polímeros/química , Povidona , Difracción de Rayos XRESUMEN
The antischistosomal drug oxamniquine, OXA, requires activation by a sulfotransferase within the parasitic worm to enable killing. Examination of the pharmacokinetic/pharmacodynamic (PK/PD) relationship for OXA identified an in vitro-in vivo paradox with the maximal clinical plasma concentrations five-to ten-times lower than the efficacious concentration for in vitro schistosomal killing. The parasite resides in the vasculature between the intestine and the liver, and modeling the PK data to determine portal concentrations fits with in vitro studies and explains the required human dose. In silico models were used to predict murine dosing to recapitulate human conditions for OXA portal concentration and time course. Follow-up PK studies verified in mice that a 50-100 mg/kg oral gavage dose of OXA formulated in acetate buffer recapitulates the 20-40 mg/kg dose common in patients. OXA was rapidly cleared through a combination of metabolism and excretion into bile. OXA absorbance and tissue distribution were similar in wild-type and P-gp efflux transporter knockout mice. The incorporation of in vitro efficacy data and portal concentration was demonstrated for an improved OXA-inspired analog that has been shown to kill S. mansoni, S. haematobium, and S. japonicum, whereas OXA is only effective against S. mansoni. Second-generation OXA analogs should optimize both in vitro killing and physiochemical properties to achieve high portal concentration via rapid oral absorption, facilitated by favorable solubility, permeability, and minimal intestinal metabolism.