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1.
Bioorg Med Chem ; 102: 117679, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38461555

RESUMO

Trichomoniasis, a prevalent sexually transmitted infection (STI) caused by the protozoan Trichomonas vaginalis, has gained increased significance globally. Its relevance has grown in recent years due to its association with a heightened risk of acquiring and transmitting the human immunodeficiency virus (HIV) and other STIs. In addition, many publications have revealed a potential link between trichomoniasis and certain cancers. Metronidazole (MTZ), a nitroimidazole compound developed over 50 years ago, remains the first-choice drug for treatment. However, reports of genotoxicity and side effects underscore the necessity for new compounds to address this pressing global health concern. In this study, we synthesized ten pyrazole-nitroimidazoles 1(a-j) and 4-nitro-1-(hydroxyethyl)-1H-imidazole 2, an analog of metronidazole (MTZ), and assessed their trichomonacidal and cytotoxic effects. All compounds 1(a-j) and 2 exhibited IC50 values ≤ 20 µM and ≤ 41 µM, after 24 h and 48 h, respectively. Compounds 1d (IC50 5.3 µM), 1e (IC50 4.8 µM), and 1i (IC50 5.2 µM) exhibited potencies equivalent to MTZ (IC50 4.9 µM), the reference drug, after 24 h. Notably, compound 1i showed high anti-trichomonas activity after 24 h (IC50 5.2 µM) and 48 h (IC50 2.1 µM). Additionally, all compounds demonstrated either non-cytotoxic to HeLa cells (CC50 > 100 µM) or low cytotoxicity (CC50 between 69 and 100 µM). These findings suggest that pyrazole-nitroimidazole derivatives represent a promising heterocyclic system, serving as a potential lead for further optimization in trichomoniasis chemotherapy.


Assuntos
Antiprotozoários , Nitroimidazóis , Tricomoníase , Trichomonas vaginalis , Humanos , Nitroimidazóis/farmacologia , Metronidazol/farmacologia , Células HeLa , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Tricomoníase/tratamento farmacológico , Pirazóis/farmacologia , Pirazóis/uso terapêutico
2.
Antimicrob Agents Chemother ; 68(4): e0155923, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38497616

RESUMO

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


Assuntos
Antiprotozoários , Leishmania infantum , Leishmania mexicana , Leishmaniose , Animais , Camundongos , Humanos , Leishmaniose/tratamento farmacológico , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Expressão Gênica , Camundongos Endogâmicos BALB C
3.
PLoS Negl Trop Dis ; 18(3): e0012050, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38527083

RESUMO

Pharmacophores such as hydroxyethylamine (HEA) and phthalimide (PHT) have been identified as potential synthons for the development of compounds against various parasitic infections. In order to further advance our progress, we conducted an experiment utilising a collection of PHT and HEA derivatives through phenotypic screening against a diverse set of protist parasites. This approach led to the identification of a number of compounds that exhibited significant effects on the survival of Entamoeba histolytica, Trypanosoma brucei, and multiple life-cycle stages of Leishmania spp. The Leishmania hits were pursued due to the pressing necessity to expand our repertoire of reliable, cost-effective, and efficient medications for the treatment of leishmaniases. Antileishmanials must possess the essential capability to efficiently penetrate the host cells and their compartments in the disease context, to effectively eliminate the intracellular parasite. Hence, we performed a study to assess the effectiveness of eradicating L. infantum intracellular amastigotes in a model of macrophage infection. Among eleven L. infantum growth inhibitors with low-micromolar potency, PHT-39, which carries a trifluoromethyl substitution, demonstrated the highest efficacy in the intramacrophage assay, with an EC50 of 1.2 +/- 3.2 µM. Cytotoxicity testing of PHT-39 in HepG2 cells indicated a promising selectivity of over 90-fold. A chemogenomic profiling approach was conducted using an orthology-based method to elucidate the mode of action of PHT-39. This genome-wide RNA interference library of T. brucei identified sensitivity determinants for PHT-39, which included a P-type ATPase that is crucial for the uptake of miltefosine and amphotericin, strongly indicating a shared route for cellular entry. Notwithstanding the favourable properties and demonstrated efficacy in the Plasmodium berghei infection model, PHT-39 was unable to eradicate L. major infection in a murine infection model of cutaneous leishmaniasis. Currently, PHT-39 is undergoing derivatization to optimize its pharmacological characteristics.


Assuntos
Antiprotozoários , Leishmania infantum , Leishmania , Leishmaniose Cutânea , Humanos , Animais , Camundongos , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Anfotericina B/uso terapêutico , Leishmaniose Cutânea/parasitologia , Ftalimidas/farmacologia , Ftalimidas/uso terapêutico
4.
Antimicrob Agents Chemother ; 68(3): e0112723, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38349159

RESUMO

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


Assuntos
Antiprotozoários , Leishmania infantum , Leishmaniose , Parasitos , Animais , Humanos , Células Endoteliais , Leishmaniose/tratamento farmacológico , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico
5.
PLoS One ; 19(2): e0296728, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38354178

RESUMO

INTRODUCTION: American Tegumentary Leishmaniasis (ATL) treatment is based on pentavalent antimonials (Sb5+), but these drugs have been associated to several adverse effects. Hearing loss and tinnitus during treatment with meglumine antimoniate (MA) have already been reported. This study aimed to describe the usefulness of self-reporting of hearing loss and tinnitus in diagnosing MA-induced ototoxicity. METHODS: A prospective longitudinal study was conducted with 102 patients with parasitological diagnosis of ATL, treated with different MA schemes. The presence of clinical auditory toxicity was defined as the emergence or worsening of self-reporting hearing loss and/or tinnitus during monitoring. Measures of sensitivity, specificity, and the positive and negative predictive value of the patient's self-reporting of hearing loss and tinnitus in relation to the result of the audiometric test (considered the gold standard) were calculated. RESULTS: The age of the evaluated patients ranged from 15 to 81 years, with a median of 41 years, and most were male (73.5%). Seventy-five patients (73.5%) had cutaneous leishmaniasis and 27 (26.5%) mucosal leishmaniasis. Eighty-six patients (84.3%) received intramuscular (IM) treatment and 16 (15.7%) were treated with intralesional MA. During treatment, 18 (17,6%) had tinnitus and 7 (6,9%) had complaint of hearing loss. 53 (52%) patients had cochlear toxicity confirmed by tone threshold audiometry and high frequency audiometry, from which 60% received a dose of 20 mg Sb5+/kg/day (p = 0.015) and 96.2% were treated with IM MA (p = 0.001). Tinnitus has greater specificity and positive predictive value than hearing loss, with a low number of false positives, but with a high false negative value. CONCLUSION: Although the large number of false negatives suggests that self-report of hearing loss or tinnitus cannot be considered a good screening test for referring the patient to an audiometry, the low number of false positives suggests the need to value the patient's complaint for referral. Otherwise, this study reinforces the importance of audiological monitoring during treatment with MA, especially in those patients with self-reporting of hearing loss or tinnitus when treated with 20 mg Sb5+/kg/day via IM.


Assuntos
Antiprotozoários , Surdez , Perda Auditiva , Leishmaniose Cutânea , Compostos Organometálicos , Ototoxicidade , Zumbido , Humanos , Masculino , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Feminino , Antimoniato de Meglumina/efeitos adversos , Zumbido/induzido quimicamente , Zumbido/diagnóstico , Zumbido/tratamento farmacológico , Meglumina/efeitos adversos , Antiprotozoários/uso terapêutico , Estudos Longitudinais , Estudos Prospectivos , Compostos Organometálicos/efeitos adversos , Leishmaniose Cutânea/diagnóstico , Leishmaniose Cutânea/tratamento farmacológico , Perda Auditiva/induzido quimicamente , Perda Auditiva/diagnóstico
6.
PLoS Negl Trop Dis ; 18(2): e0012015, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38422164

RESUMO

BACKGROUND: Visceral leishmaniasis (VL) resolution depends on a wide range of factors, including the instauration of an effective treatment coupled to a functional host immune system. Patients with a depressed immune system, like the ones receiving methotrexate (MTX), are at higher risk of developing VL and refusing antileishmanial drugs. Moreover, the alarmingly growing levels of antimicrobial resistance, especially in endemic areas, contribute to the increasing the burden of this complex zoonotic disease. PRINCIPAL FINDINGS: To understand the potential links between immunosuppressants and antileishmanial drugs, we have studied the interaction of antimony (Sb) and MTX in a Leishmania infantum reference strain (LiWT) and in two L. infantum clinical strains (LiFS-A and LiFS-B) naturally circulating in non-treated VL dogs in Spain. The LiFS-A strain was isolated before Sb treatment in a case that responded positively to the treatment, while the LiFS-B strain was recovered from a dog before Sb treatment, with the dog later relapsing after the treatment. Our results show that, exposure to Sb or MTX leads to an increase in the production of reactive oxygen species (ROS) in LiWT which correlates with a sensitive phenotype against both drugs in promastigotes and intracellular amastigotes. LiFS-A was sensitive against Sb but resistant against MTX, displaying high levels of protection against ROS when exposed to MTX. LiFS-B was resistant to both drugs. Evaluation of the melting proteomes of the two LiFS, in the presence and absence of Sb and MTX, showed a differential enrichment of direct and indirect targets for both drugs, including common and unique pathways. CONCLUSION: Our results show the potential selection of Sb-MTX cross-resistant parasites in the field, pointing to the possibility to undermine antileishmanial treatment of those patients being treated with immunosuppressant drugs in Leishmania endemic areas.


Assuntos
Antiprotozoários , Leishmania infantum , Leishmaniose Visceral , Humanos , Animais , Cães , Metotrexato/farmacologia , Metotrexato/uso terapêutico , Antimônio/farmacologia , Antimônio/uso terapêutico , Espécies Reativas de Oxigênio , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Leishmaniose Visceral/tratamento farmacológico , Leishmaniose Visceral/veterinária , Resistência a Medicamentos
7.
Ticks Tick Borne Dis ; 15(3): 102315, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38301344

RESUMO

Canine babesiosis has been increasingly diagnosed in various regions of Germany such as north-eastern Germany in recent years. A dog with several relapses of Babesia canis infection after treatment with imidocarb is described. A 9-year-old male Magyar Viszla with B. canis infection was referred after two treatments with imidocarb (dosage 2.1 mg/kg SC) because of lethargy, fever and pancytopenia (additional treatments with prednisolone and doxycycline). Merozoites were detected in the blood smear and imidocarb treatment was repeated. Clinical signs, pancytopenia and a positive B. canis PCR occurred after the 3rd (6 mg/kg SC), 4th (7.7 mg/kg SC) and 5th (7.5 mg/kg SC and doxycycline for 4 weeks in addition) imidocarb injection and thorough tick prevention with isoxazoline and permethrin products. 12 days after the 5th injection, the PCR was negative for the first time. The dog was again presented with fever 35 days after the 5th injection. The B. canis PCR was positive and laboratory examination revealed pancytopenia. Treatment with atovaquone/azithromycin for 18 days was performed and no further relapse occurred for 32 weeks. In the case of suspected imidocarb resistance in B. canis infection, treatment with atovaquone/azithromycin can be an alternative.


Assuntos
Antiprotozoários , Babesia , Babesiose , Doenças do Cão , Pancitopenia , Masculino , Cães , Animais , Imidocarbo/uso terapêutico , Antiprotozoários/uso terapêutico , Atovaquona/farmacologia , Atovaquona/uso terapêutico , Doxiciclina/uso terapêutico , Azitromicina/uso terapêutico , Pancitopenia/tratamento farmacológico , Babesiose/tratamento farmacológico , Babesiose/epidemiologia , Babesiose/diagnóstico , Alemanha/epidemiologia , Falha de Tratamento , Doenças do Cão/tratamento farmacológico , Doenças do Cão/epidemiologia , Doenças do Cão/diagnóstico
8.
Acta Trop ; 252: 107155, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38373527

RESUMO

This study aimed to produce linalool loaded zinc oxide nanocomposite (LZNPs) and assess its in vitro and in vivo antileishmanial effects against Leishmania major. LZNPs was produced through the synthesis of an ethanolic solution containing polyvinyl alcohol. The average size of LZNPs was determined to be 105 nm. The findings indicated that LZNPs displayed significant (p < 0.01) antileishmanial effects on promastigotes and amastigotes. Following exposure of promastigotes to LZNPs, there was a notable rise in the percentage of early and late apoptotic cells from 9.0 to 57.2 %. The gene expression levels of iNOS, IFN-γ, and TNF-α in macrophages were upregulated in a dose-dependent approach following exposure to LZNPs. LZNPs alone and in conjunction with glucantime (Glu) resulted in a reduction in the diameter and parasite load of CL lesions in infected mice. Treatment of the CL-infected mice with LZNPs at 25 and 50 mg/kg mainly in combination with Glu-reduced the tissue level of malondialdehyde (MDA), increased both gene and protein expression of the antioxidant enzymes as well as raised the expression level of IFN-γ and IL-12 cytokines, whereas caused a significant reduction in the expression level of IL-4. The present study shows that LZNPs has potent antileishmanial effects and controls CL in a mice model through its antioxidant and immunomodulatory properties. Further investigation, especially in clinical trials, could explore the potential use of this nanocomposite in managing and treating CL.


Assuntos
Monoterpenos Acíclicos , Antiprotozoários , Cicloexanóis , Compostos de Tritil , Óxido de Zinco , Animais , Camundongos , Óxido de Zinco/farmacologia , Antioxidantes/farmacologia , Zinco , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Antimoniato de Meglumina , Camundongos Endogâmicos BALB C
9.
Acta Trop ; 252: 107139, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38307362

RESUMO

Clotrimazole is an FDA approved drug and is widely used as an antifungal agent. An extensive body of research is available about its mechanism of action on various cell types but its mode of killing of Leishmania donovani parasites is unknown. L. donovani causes Visceral Leishmaniasis which is a public health problem with limited treatment options. Its present chemotherapy is expensive, has adverse effects and is plagued with drug resistance issues. In this study we have explored the possibility of repurposing clotrimazole as an antileishmanial drug. We have assessed its efficacy on the parasites and attempted to understand its mode of action. We found that it has a half-maximal inhibitory concentration (IC50) of 35.75 ± 1.06 µM, 12.75 ± 0.35 µM and 73 ± 1.41 µM in promastigotes, intracellular amastigotes and macrophages, respectively. Clotrimazole is 5.73 times more selective for the intracellular amastigotes as compared to the mammalian cell. Effect of clotrimazole was reduced by ergosterol supplementation. It leads to impaired parasite morphology. It alters plasma membrane permeability and disrupts plasma membrane potential. Mitochondrial function is compromised as is evident from increased ROS generation, depolarized mitochondrial membrane and decreased ATP levels. Cell cycle analysis of clotrimazole treated parasites shows arrest at sub-G0 phase suggesting apoptotic mode of cell death.


Assuntos
Antiprotozoários , Leishmania donovani , Leishmaniose Visceral , Animais , Clotrimazol/farmacologia , Clotrimazol/metabolismo , Clotrimazol/uso terapêutico , Leishmaniose Visceral/tratamento farmacológico , Leishmaniose Visceral/parasitologia , Macrófagos , Pontos de Checagem do Ciclo Celular , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Mamíferos
10.
J Med Chem ; 67(4): 2849-2863, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38330051

RESUMO

Human African trypanosomiasis (HAT) still faces few therapeutic options and emerging drug resistance, stressing an urgency for novel antitrypanosomal drug discovery. Here, we describe lead optimization efforts aiming at improving antitrypanosomal efficacy and better physicochemical properties based on our previously reported optimized hit NPD-2975 (pIC50 7.2). Systematic modification of the 5-phenylpyrazolopyrimidinone NPD-2975 led to the discovery of a R4-substituted analogue 31c (NPD-3519), showing higher in vitro potency (pIC50 7.8) against Trypanosoma brucei and significantly better metabolic stability. Further, in vivo pharmacokinetic evaluation of 31c and experiments in an acute T. brucei mouse model confirmed improved oral bioavailability and antitrypanosomal efficacy at 50 mg/kg with no apparent toxicity. With good physicochemical properties, low toxicity, improved pharmacokinetic features, and in vivo efficacy, 31c may serve as a promising candidate for future drug development for HAT.


Assuntos
Antiprotozoários , Tripanossomicidas , Trypanosoma brucei brucei , Tripanossomíase Africana , Animais , Camundongos , Humanos , Tripanossomicidas/farmacologia , Tripanossomicidas/uso terapêutico , Tripanossomíase Africana/tratamento farmacológico , Antiprotozoários/uso terapêutico , Desenvolvimento de Medicamentos
12.
PLoS Negl Trop Dis ; 18(1): e0011559, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38166146

RESUMO

The parasite Leishmania donovani is one of the species causing visceral leishmaniasis in humans, a deadly infection claiming up to 40,000 lives each year. The current drugs for leishmaniasis treatment have severe drawbacks and there is an urgent need to find new anti-leishmanial compounds. However, the search for drug candidates is complicated by the intracellular lifestyle of Leishmania. Here, we investigate the use of human induced pluripotent stem cell (iPS)-derived macrophages (iMACs) as host cells for L. donovani. iMACs obtained through embryoid body differentiation were infected with L. donovani promastigotes, and high-content imaging techniques were used to optimize the iMACs seeding density and multiplicity of infection, allowing us to reach infection rates up to 70% five days after infection. IC50 values obtained for miltefosine and amphotericin B using the infected iMACs or mouse peritoneal macrophages as host cells were comparable and in agreement with the literature, showing the potential of iMACs as an infection model for drug screening.


Assuntos
Antiprotozoários , Células-Tronco Pluripotentes Induzidas , Leishmania donovani , Leishmaniose Visceral , Animais , Humanos , Camundongos , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Leishmaniose Visceral/parasitologia , Macrófagos/parasitologia
13.
Arch Med Res ; 55(2): 102958, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38290200

RESUMO

BACKGROUND: Chagas disease and cutaneous leishmaniasis, two parasitic diseases caused by Trypanosoma cruzi (T. cruzi) and Leishmania mexicana (L. mexicana), respectively, have a major global impact. Current pharmacological treatments for these diseases are limited and can cause severe side effects; thus, there is a need for new antiprotozoal drugs. METHODS: Using molecular docking, this work describes a structure-based virtual screening of an FDA-approved drug library against Trypanosoma cruzi and Leishmania mexicana glycolytic enzyme triosephosphate isomerase (TIM), which is highly conserved in these parasites. The selected compounds with potential dual inhibitory activity were tested in vitro to confirm their biological activity. RESULTS: The study showed that five compounds: nilotinib, chlorhexidine, protriptyline, cyproheptadine, and montelukast, were more active against T. cruzi, than the reference drugs, nifurtimox and benznidazole while chlorhexidine and protriptyline were the most active against L. mexicana. CONCLUSIONS: The analysis of these compounds and their structural characteristics may provide the basis for the development of new antiprotozoal agents.


Assuntos
Antiprotozoários , Doença de Chagas , Leishmaniose Cutânea , Trypanosoma cruzi , Humanos , Simulação de Acoplamento Molecular , Clorexidina/farmacologia , Clorexidina/uso terapêutico , Protriptilina/farmacologia , Protriptilina/uso terapêutico , Doença de Chagas/tratamento farmacológico , Leishmaniose Cutânea/tratamento farmacológico , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Antiprotozoários/química
14.
Pathog Glob Health ; 118(1): 40-46, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-37183476

RESUMO

The visceral form of leishmaniasis (VL), due to infection by Leishmania infantum, is a neglected tropical disease. The accessible therapeutic options are limited. Artemisinin is an efficient antileishmanial product with poor biological availability that requires high repetition of therapeutic doses in VL. Solid lipid nanoparticles (SLNs) provide targeted delivery, increase bioavailability and reduce toxicity of the traditional therapeutic strategy. The spherical shape artemisinin-loaded SLNs were prepared in a particle diameter of 222.0 ± 14.0 nm. The SLNs showed no particular toxic effect on the parasites, whereas the native artemisinin demonstrated a significant toxicity rate of 31% in viability of the promastigotes at the 250 µg/ml concentration. The therapeutic efficacy of the artemisinin-loaded SLNs was demonstrated in the experimental VL, using the L. infantum-infected BALB/c mice, in the present study. The 10 and 20 mg/kg doses of artemisinin-loaded SLNs showed higher level of antileishmanial efficacy compared with the free artemisinin. There was a significant diminishing of the parasite burden in liver (84.7 ± 4.9%) and spleen (85.0 ± 3.1%) and hepatosplenomegaly by the artemisinin-loaded SLNs treated at 20 mg/kg compared to the free artemisinin. Therefore, the present study supports the superior efficacy of artemisinin-loaded SLNs over the free artemisinin and could be considered as a new therapeutic strategy in the treatment of leishmaniasis.


Assuntos
Antiprotozoários , Artemisininas , Leishmania infantum , Leishmaniose Visceral , Leishmaniose , Parasitos , Animais , Camundongos , Leishmaniose Visceral/tratamento farmacológico , Antiprotozoários/uso terapêutico , Leishmaniose/tratamento farmacológico , Artemisininas/uso terapêutico , Artemisininas/farmacologia , Camundongos Endogâmicos BALB C
15.
Antimicrob Agents Chemother ; 68(1): e0050923, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38063403

RESUMO

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


Assuntos
Antiprotozoários , Leishmania braziliensis , Leishmania infantum , Leishmaniose , Cricetinae , Animais , Camundongos , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Fluorescência , Leishmaniose/tratamento farmacológico , Leishmania infantum/genética , Leishmania braziliensis/genética , Mesocricetus , Camundongos Endogâmicos BALB C
16.
Parasitology ; 151(1): 1-14, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38012864

RESUMO

Leishmaniasis is a vector-borne parasitic disease caused by Leishmania parasites with a spectrum of clinical manifestations, ranging from skin lesions to severe visceral complications. Treatment of this infection has been extremely challenging with the concurrent emergence of drug resistance. The differential gene expression and the discrepancies in protein functions contribute to the appearance of 2 distinct phenotypes: resistant and sensitive, but the current diagnostic tools fail to differentiate between them. The identification of gene expression patterns and molecular mechanisms coupled with antimony (Sb) resistance can be leveraged to prompt diagnosis and select the most effective treatment methods. The present study attempts to use comparative expression of Sb resistance-associated genes in resistant and sensitive Leishmania, to disclose their relative abundance in clinical or in vitro selected isolates to gain an understanding of the molecular mechanisms of Sb response/resistance. Data suggest that the analysis of resistance gene expression would verify the Sb resistance or susceptibility only to a certain extent; however, none of the individual expression patterns of the studied genes was diagnostic as a biomarker of Sb response of Leishmania. The findings highlighted will be useful in bridging the knowledge gap and discovering innovative diagnostic tools and novel therapeutic targets.


Assuntos
Antiprotozoários , Leishmania , Leishmania/genética , Antimônio/farmacologia , Antimônio/uso terapêutico , Proteômica , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Resistência a Medicamentos/genética , Expressão Gênica
17.
Lancet Infect Dis ; 24(1): e36-e46, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37640031

RESUMO

For the past 15 years, trials of combination therapy options for visceral leishmaniasis have been conducted with the aim of identifying effective, and safe treatment regimens that were shorter than existing monotherapy regimens and could also prevent or delay the emergence of drug resistance. Although first-line treatment currently relies on combination therapy in east Africa, this is not true in Latin America owing to disappointing trial results, with lower than expected efficacy seen for the combination treatment group. By contrast, several effective combination therapy regimens have been identified through trials on the Indian subcontinent; yet, first-line therapy is still AmBisome monotherapy as the drug is part of a free donation programme and is highly effective in this region. Achieving a short all-oral combination treatment will require new chemical entities, several of which are currently under evaluation. Future studies should systematically include pharmacological substudies to ensure optimal dosing for all patient groups. To achieve maximal impact of new combination treatments, mechanisms to ensure drug availability and access after trials should be established. Enhancing the longevity of current and novel treatments will require effective systems for early detection of emerging drug resistance.


Assuntos
Antiprotozoários , Leishmaniose Visceral , Humanos , Leishmaniose Visceral/tratamento farmacológico , Antiprotozoários/uso terapêutico , Quimioterapia Combinada , Fosforilcolina/uso terapêutico , Terapia Combinada
18.
Curr Med Chem ; 31(15): 1955-1982, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37718524

RESUMO

Protozoan parasites represent a significant risk for public health worldwide, afflicting particularly people in more vulnerable categories and cause large morbidity and heavy economic impact. Traditional drugs are limited by their toxicity, low efficacy, route of administration, and cost, reflecting their low priority in global health management. Moreover, the drug resistance phenomenon threatens the positive therapy outcome. This scenario claims the need of addressing more adequate therapies. Among the diverse strategies implemented, the medicinal chemistry efforts have also focused their attention on the benzimidazole nucleus as a promising pharmacophore for the generation of new drug candidates. Hence, the present review provides a global insight into recent progress in benzimidazole-based derivatives drug discovery against important protozoan diseases, such as malaria, leishmaniasis and trypanosomiasis. The more relevant chemical features and structure-activity relationship studies of these molecules are discussed for the purpose of paving the way towards the development of more viable drugs for the treatment of these parasitic infections.


Assuntos
Antiprotozoários , Leishmaniose , Malária , Tripanossomíase , Humanos , Antiparasitários/uso terapêutico , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Antiprotozoários/química , Malária/tratamento farmacológico , Tripanossomíase/tratamento farmacológico , Leishmaniose/tratamento farmacológico , Benzimidazóis/farmacologia , Benzimidazóis/uso terapêutico
19.
Curr Top Med Chem ; 24(2): 89-108, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37842892

RESUMO

Recent developments in the use of natural product-based molecules as antiparasitic agents for Malaria, leishmaniasis (LE), Chagas disease (CD), and Human African trypanosomiasis (HAT) are reviewed. The role of diverse plants in developing bioactive species is discussed in addition to analyzing the structural diversity of natural products as active agents and the diverse biological applications in CD, HAT, LE, and Malaria. This review focuses on medicinal chemistry, emphasizing the structural characteristics of natural molecules as bioactive agents against parasitic infections caused by Leishmania, Trypanosoma, and Plasmodium parasites.


Assuntos
Antiprotozoários , Produtos Biológicos , Doença de Chagas , Leishmaniose , Malária , Tripanossomíase Africana , Animais , Humanos , Antiparasitários/farmacologia , Antiparasitários/uso terapêutico , Antiparasitários/química , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Antiprotozoários/química , Produtos Biológicos/farmacologia , Produtos Biológicos/uso terapêutico , Produtos Biológicos/química , Doenças Negligenciadas/tratamento farmacológico , Doenças Negligenciadas/parasitologia , Tripanossomíase Africana/tratamento farmacológico , Leishmaniose/tratamento farmacológico , Doença de Chagas/tratamento farmacológico , Malária/tratamento farmacológico
20.
Am J Trop Med Hyg ; 110(1): 40-43, 2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38011733

RESUMO

About 75% cases of post-kala-azar dermal leishmaniasis (PKDL) occur in India. Although the classic description of PKDL is the progression from initial hypopigmented macular lesions to papules to plaques and nodular lesions, atypical morphologies are also seen and are easily missed or misdiagnosed. We report a case of a 27-year-old man who presented to us with multiple acral ulcers and verrucous lesions for 5 years. A diagnosis of PKDL was made based on slit skin smear, histopathology, and quantitative polymerase chain reaction. The patient was given combination therapy with four doses of liposomal amphotericin B and miltefosine 50 mg twice daily for 45 days. In this report, we discuss unusual morphologies of PKDL, the pathway to the diagnosis, and the therapeutic options available along with their efficacy.


Assuntos
Antiprotozoários , Leishmaniose Cutânea , Leishmaniose Visceral , Masculino , Humanos , Adulto , Leishmaniose Visceral/complicações , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/tratamento farmacológico , Leishmaniose Cutânea/complicações , Leishmaniose Cutânea/diagnóstico , Leishmaniose Cutânea/tratamento farmacológico , Úlcera/tratamento farmacológico , Antiprotozoários/uso terapêutico , Terapia Combinada , Papillomaviridae
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