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1.
Pharmaceutics ; 16(3)2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38543309

RESUMO

Chagas disease, caused by the protozoan Trypanosoma cruzi, affects 6-7 million people worldwide. The dichloromethane extract obtained from the aerial parts of Gymnocoronis spilanthoides var subcordata showed trypanocidal activity in vitro. The fractionation of the dewaxed organic extract via column chromatography led to the isolation of three diterpenoids: ent-9α,11α-dihydroxy-15-oxo-kaur-16-en-19-oic acid or adenostemmoic acid B, (16R)-ent-11α-hydroxy-15-oxokauran-19-oic acid and ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic acid. These compounds showed IC50 values of 10.6, 15.9 and 4.8 µM against T. cruzi epimastigotes, respectively. When tested against amastigotes, the diterpenoids afforded IC50 values of 6.1, 19.5 and 60.6 µM, respectively. The cytotoxicity of the compounds was tested on mammalian cells using an MTT assay, resulting in CC50s of 321.8, 23.3 and 14.8 µM, respectively. The effect of adenostemmoic acid B on T. cruzi was examined at the ultrastructural level using transmission microscopy. Treatment with 20 µM for 48 h stimulated the formation of abnormal cytosolic membranous structures in the parasite. This compound also showed an anti-inflammatory effect in murine macrophages stimulated with LPS and other TLR agonists. Treatment of macrophages with adenostemmoic acid B was able to reduce TNF secretion and nitric oxide production, while increasing IL-10 production. The combination of adenostemmoic acid B with benznidazole resulted in greater inhibition of NF-kB and a decrease in nitrite concentration. The administration of adenostemmoic acid B to mice infected with trypomastigotes of T. cruzi at the dose of 1 mg/kg/day for five days produced a significant decrease in parasitemia levels and weight loss. Treatment with the association with benznidazole increased the survival time of the animals. In view of these results, adenostemmoic acid B could be considered a promising candidate for further studies in the search for new treatments for Chagas disease.

2.
Nat Prod Res ; 38(4): 690-695, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-36938813

RESUMO

Chagas disease is an infection caused by the protozoan Trypanosoma cruzi, affecting 6-8 million people worldwide. Only two drugs are available for its treatment, having a limited efficacy and adverse side-effects. Estafietin is a sesquiterpene lactone isolated from Stevia alpina with in vitro activity against T. cruzi and low cytotoxicity against mammalian cells. The aim of this work was to predict the toxicologic profile of estafietin by in silico methods and assess its in vivo activity on a murine model of Chagas disease. Estafietin showed low toxicity according to pkCSM web tool and passed the PAINS filter from PAINS-remover web server. The treatment of infected mice with 1 mg/Kg/day of estafietin for five consecutive days administrated by intraperitoneal route significatively decreased parasitemia levels and reduced inflammatory infiltrates and myocyte damage on muscle tissue. These results suggest that estafietin had effect both on acute and chronic stages of the infection.


Assuntos
Doença de Chagas , Stevia , Tripanossomicidas , Trypanosoma cruzi , Humanos , Camundongos , Animais , Tripanossomicidas/farmacologia , Tripanossomicidas/uso terapêutico , Doença de Chagas/tratamento farmacológico , Sesquiterpenos de Guaiano/farmacologia , Parasitemia/tratamento farmacológico , Lactonas/farmacologia , Lactonas/uso terapêutico , Mamíferos
3.
Toxicon ; 216: 115-124, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35835234

RESUMO

Encephalopathy associated with hemolytic uremic syndrome is produced by enterohemorrhagic E. coli (EHEC) infection, which releases the virulence factors Shiga toxin (Stx) and lipopolysaccharide (LPS). Neurological compromise is a poor prognosis and mortality factor of the disease, and the thalamus is one of the brain areas most frequently affected. We have previously demonstrated the effectiveness of anti-inflammatory drugs to ameliorate the deleterious effects of these toxins. However, the thalamic production of cytokines involved in pro-inflammatory processes has not yet been acknowledged. The aim of this work attempts to determine whether systemic sublethal Stx2a or co-administration of Stx2a with LPS are able to rise a proinflammatory profile accompanying alterations of the neurovascular unit in anterior and lateral ventral nuclei of the thalamus (VA-VL) and motor behavior in mice. After 4 days of treatment, Stx2a affected the lectin-bound microvasculature distribution while increasing the expression of GFAP in reactive astrocytes and producing aberrant NeuN distribution in degenerative neurons. In addition, increased swimming latency was observed in a motor behavioral test. All these alterations were heightened when Stx2a was co-administered with LPS. The expression of pro-inflammatory cytokines TNFα, INF-γ and IL-2 was detected in VA-VL. All these effects were concomitant with increased expression of the Stx receptor globotriaosylceramide (Gb3), which hints at receptor involvement in the neuroinflammatory process as a key finding of this study. In conclusion, Stx2a to Gb3 may be determinant in triggering a neuroinflammatory event, which may resemble clinical outcomes and should thus be considered in the development of preventive strategies.


Assuntos
Infecções por Escherichia coli , Toxina Shiga II , Animais , Citocinas/metabolismo , Escherichia coli/metabolismo , Lipopolissacarídeos/toxicidade , Camundongos , Toxina Shiga/metabolismo , Toxina Shiga II/toxicidade , Tálamo/metabolismo , Triexosilceramidas
4.
Molecules ; 27(10)2022 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-35630539

RESUMO

Cancer is one of the most important causes of death worldwide. Solid tumors represent the vast majority of cancers (>90%), and the chemotherapeutic agents used for their treatment are still characterized by variable efficacy and toxicity. Sesquiterpenes are a group of natural compounds that have shown a wide range of biological activities, including cytotoxic and antiparasitic activity, among others. The antiproliferative activity of natural sesquiterpenes, tessaric acid, ilicic acid, and ilicic alcohol and their semisynthetic derivatives against HeLa, T-47D, WiDr, A549, HBL-100, and SW1573 cell lines were evaluated. The effect of the compounds on Trypanosoma cruzi epimastigotes was also assessed. The selectivity index was calculated using murine splenocytes. Derivatives 13 and 15 were the most antiproliferative compounds, with GI50 values ranging between 5.3 (±0.32) and 14 (±0.90) µM, in all cell lines tested. The presence of 1,2,3-triazole groups in derivatives 15−19 led to improvements in activity compared to those corresponding to the starting natural product (3), with GI50 values ranging between 12 (±1.5) and 17 (±1.1) µM and 16 being the most active compound. In relation to the anti-T. cruzi activity, derivatives 7 and 16 obtained from tessaric acid and ilicic acid were among the most active and selective compounds with IC50 values of 9.3 and 8.8 µM (SI = 8.0 and 9.4), respectively.


Assuntos
Antineoplásicos , Sesquiterpenos , Trypanosoma cruzi , Animais , Antineoplásicos/farmacologia , Células HeLa , Humanos , Camundongos , Sesquiterpenos/farmacologia , Relação Estrutura-Atividade
5.
ACS Omega ; 7(1): 968-978, 2022 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-35036760

RESUMO

The sesquiterpene lactones cumanin, helenalin, and hymenin and their semisynthetic derivatives were evaluated against Trypanosoma cruzi epimastigotes. The cytotoxicity of the compounds was evaluated on murine splenocytes. Cumanin diacetate was one of the most active and selective compounds [IC50 = 3.20 ± 0.52 µg/mL, selectivity index (SI) = 26.0]. This sesquiterpene lactone was selected for its evaluation on trypomastigote and amastigote forms of the parasite. The diacetylated derivative of cumanin showed moderate activity on trypomastigotes (IC50 = 32.4 ± 5.8 µg/mL). However, this compound was able to efficiently inhibit parasite replication with an IC50 value of 2.2 ± 0.05 µg/mL against the amastigote forms. Cumanin diacetate showed selectivity against the intracellular forms of Trypanosoma cruzi with an SI value of 52.7. This cumanin analogue was also active on an in vivo model of Chagas disease, leading to a reduction in the parasitemia levels in comparison with nontreated animals. Histopathological analysis of skeletal muscular tissues from treated mice showed only focal interstitial lymphocyte inflammatory infiltrates with slight myocyte necrosis; in contrast, nontreated animals showed severe lymphocyte inflammatory infiltrates with necrosis of the myocytes. A molecular docking study of cumanin and its derivatives on trypanothione reductase from T. cruzi (TcTR) was performed. The results of ΔG docking achieved let the identification of diacetylated and O-alkylated derivatives of cumanin as good inhibitors of TcTR. Cumanin diacetate could be considered a potential candidate for further studies for the development of new therapies against Chagas disease.

6.
Front Immunol ; 11: 565142, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33162979

RESUMO

Chagas disease caused by the protozoan parasite Trypanosoma cruzi is endemic in 21 Latin American countries and the southern United States and now is spreading into several other countries due to migration. Despite the efforts to control the vector throughout the Americas, currently, there are almost seven million infected people worldwide, causing ~10,000 deaths per year, and 70 million people at risk to acquire the infection. Chagas disease treatment is restricted only to two parasiticidal drugs, benznidazole and nifurtimox, which are effective during the acute and early infections but have not been found to be as effective in chronic infection. No prophylactic or therapeutic vaccine for human use has been communicated at this moment. Here, we evaluate in a mouse model a therapeutic DNA vaccine combining Cruzipain (Cz), a T. cruzi cysteine protease that proved to be protective in several settings, and Chagasin (Chg), which is the natural Cz inhibitor. The DNAs of both antigens, as well as a plasmid encoding GM-CSF as adjuvant, were orally administrated and delivered by an attenuated Salmonella strain to treat mice during the acute phase of T. cruzi infection. The bicomponent vaccine based on Salmonella carrying Cz and Chg (SChg+SCz) was able to improve the protection obtained by each antigen as monocomponent therapeutic vaccine and significantly increased the titers of antigen- and parasite-specific antibodies. More importantly, the bicomponent vaccine triggered a robust cellular response with interferon gamma (IFN-γ) secretion that rapidly reduced the parasitemia during the acute phase and decreased the tissue damage in the chronic stage of the infection, suggesting it could be an effective tool to ameliorate the pathology associated to Chagas disease.


Assuntos
Doença de Chagas/prevenção & controle , Cisteína Endopeptidases/imunologia , Proteínas de Protozoários/imunologia , Vacinas Protozoárias/imunologia , Trypanosoma cruzi/imunologia , Vacinação/métodos , Vacinas de DNA/imunologia , Adjuvantes Imunológicos/administração & dosagem , Administração Oral , Animais , Anticorpos Antiprotozoários/imunologia , Antígenos de Protozoários/imunologia , Doença de Chagas/parasitologia , Modelos Animais de Doenças , Feminino , Imunidade Celular , Interferon gama/metabolismo , Camundongos , Camundongos Endogâmicos C3H , Vacinas Protozoárias/administração & dosagem , Salmonella/imunologia , Resultado do Tratamento , Vacinas Atenuadas , Vacinas de DNA/administração & dosagem
7.
Molecules ; 25(9)2020 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-32344932

RESUMO

The sesquiterpene lactones eupatoriopicrin, estafietin, eupahakonenin B and minimolide have been isolated from Argentinean Astearaceae species and have been found to be active against Trypanosoma cruzi epimastigotes. The aim of this work was to evaluate the activity of these compounds by analyzing their effect against the stages of the parasites that are infective for the human. Even more interesting, we aimed to determine the effect of the most active and selective compound on an in vivo model of T. cruzi infection. Eupatoriopicrin was the most active against amastigotes and tripomastigotes (IC50 = 2.3 µg/mL, and 7.2 µg/mL, respectively) and displayed a high selectivity index. This compound was selected to study on an in vivo model of T. cruzi infection. The administration of 1 mg/kg/day of eupatoriopicrin for five consecutive days to infected mice produced a significant reduction in the parasitaemia levels in comparison with non-treated animals (area under parasitaemia curves 4.48 vs. 30.47, respectively). Skeletal muscular tissues from eupatopicrin-treated mice displayed only focal and interstitial lymphocyte inflammatory infiltrates and small areas of necrotic; by contrast, skeletal tissues from T. cruzi infected mice treated with the vehicle showed severe lymphocyte inflammatory infiltrates with necrosis of the adjacent myocytes. The results indicate that eupatoriopicrin could be considered a promising candidate for the development of new therapeutic agents for Chagas disease.


Assuntos
Asteraceae/química , Lactonas/farmacologia , Extratos Vegetais/farmacologia , Sesquiterpenos/farmacologia , Tripanossomicidas/farmacologia , Animais , Doença de Chagas/tratamento farmacológico , Doença de Chagas/parasitologia , Doença de Chagas/patologia , Humanos , Lactonas/química , Camundongos , Estrutura Molecular , Testes de Sensibilidade Parasitária , Compostos Fitoquímicos/química , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Sensibilidade e Especificidade , Sesquiterpenos/química , Sesquiterpenos/isolamento & purificação , Tripanossomicidas/química , Tripanossomicidas/isolamento & purificação , Trypanosoma cruzi/efeitos dos fármacos
8.
Front Immunol ; 11: 128, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32153562

RESUMO

There are several unmet needs in modern immunology. Among them, vaccines against parasitic diseases and chronic infections lead. Trypanosoma cruzi, the causative agent of Chagas disease, is an excellent example of a silent parasitic invasion that affects millions of people worldwide due to its progression into the symptomatic chronic phase of infection. In search for novel vaccine candidates, we have previously introduced Traspain, an engineered trivalent immunogen that was designed to address some of the known mechanisms of T. cruzi immune evasion. Here, we analyzed its performance in different DNA prime/protein boost protocols and characterized the systemic immune response associated with diverse levels of protection. Formulations that include a STING agonist, like c-di-AMP in the boost doses, were able to prime a Th1/Th17 immune response. Moreover, comparison between them showed that vaccines that were able to prime polyfunctional cell-mediated immunity at the CD4 and CD8 compartment enhanced protection levels in the murine model. These findings contribute to a better knowledge of the desired vaccine-elicited immunity against T. cruzi and promote the definition of a vaccine correlate of protection against the infection.


Assuntos
Imunidade/imunologia , Vacinas Protozoárias/imunologia , Trypanosoma cruzi/imunologia , Vacinação/métodos , Animais , Linfócitos T CD4-Positivos , Linfócitos T CD8-Positivos/imunologia , Citocinas/metabolismo , Feminino , Imunização Secundária , Masculino , Camundongos , Modelos Animais , Resultado do Tratamento
9.
Biochim Biophys Acta Mol Basis Dis ; 1866(5): 165658, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-31904415

RESUMO

Chagas disease is currently endemic to 21 Latin-American countries and has also become a global concern because of globalization and mass migration of chronically infected individuals. Prophylactic and therapeutic vaccination might contribute to control the infection and the pathology, as complement of other strategies such as vector control and chemotherapy. Ideal prophylactic vaccine would produce sterilizing immunity; however, a reduction of the parasite burden would prevent progression from Trypanosoma cruzi infection to Chagas disease. A therapeutic vaccine for Chagas disease may improve or even replace the treatment with current drugs which have several side effects and require long term treatment that frequently leads to therapeutic withdrawal. Here, we will review some aspects about sub-unit vaccines, the rationale behind the selection of the immunogen, the role of adjuvants, the advantages and limitations of DNA-based vaccines and the idea of therapeutic vaccines. One of the main limitations to advance vaccine development against Chagas disease is the high number of variables that must be considered and the lack of uniform criteria among research laboratories. To make possible comparisons, much of this review will be focused on experiments that kept many variables constant including antigen mass/doses, type of eukaryotic plasmid, DNA-delivery system, mice strain and sex, lethal and sublethal model of infection, and similar immunogenicity and efficacy assessments.


Assuntos
Antígenos de Protozoários/imunologia , Cardiomiopatia Chagásica/prevenção & controle , Vacinas Protozoárias/imunologia , Projetos de Pesquisa , Trypanosoma cruzi/imunologia , Animais , Cardiomiopatia Chagásica/imunologia , Cardiomiopatia Chagásica/parasitologia , Modelos Animais de Doenças , Feminino , Humanos , Imunogenicidade da Vacina , Masculino , Camundongos , Vacinas Protozoárias/administração & dosagem , Fatores Sexuais , Vacinas de Subunidades Antigênicas/administração & dosagem , Vacinas de Subunidades Antigênicas/imunologia
10.
Molecules ; 24(6)2019 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-30897836

RESUMO

Cancer is one of the most important causes of death worldwide. Solid tumors represent the great majority of cancers (>90%) and the chemotherapeutic agents used for their treatment are still characterized by variable efficacy and toxicity. Sesquiterpene lactones are a group of naturally occurring compounds that have displayed a diverse range of biological activities including cytotoxic activity. A series of oxygenated and oxy-nitrogenated derivatives (4⁻15) from the sesquiterpene lactones cumanin (1), helenalin (2), and hymenin (3) were synthesized. The silylated derivatives of helenalin, compounds 13 and 14, were found to be the most active against tumor cell lines, with GI50 values ranging from 0.15 to 0.59 µM. The ditriazolyl cumanin derivative (11) proved to be more active and selective than cumanin in the tested breast, cervix, lung, and colon tumor cell lines. This compound was the least toxic against splenocytes (CC50 = 524.1 µM) and exhibited the greatest selectivity on tumor cell lines. This compound showed a GI50 of 2.3 µM and a SI of 227.9 on WiDr human colon tumor cell lines. Thus, compound 11 can be considered for further studies and is a candidate for the development of new antitumor agents.


Assuntos
Lactonas/química , Sesquiterpenos/química , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias do Colo/metabolismo , Humanos , Lactonas/farmacologia , Sesquiterpenos/farmacologia , Sesquiterpenos de Guaiano
11.
Molecules ; 24(7)2019 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-30925657

RESUMO

Sesquiterpene lactones are naturally occurring compounds mainly found in the Asteraceae family. These types of plant metabolites display a wide range of biological activities, including antiprotozoal activity and are considered interesting structures for drug discovery. Four derivatives were synthesized from estafietin (1), isolated from Stevia alpina (Asteraceae): 11ßH,13-dihydroestafietin (2), epoxyestafietin (3a and 3b), 11ßH,13-methoxyestafietin, (4) and 11ßH,13-cianoestafietin. The antiprotozoal activity against Trypanosoma cruzi and Leishmania braziliensis of these compounds was evaluated. Epoxyestafietin was the most active compound against T. cruzi trypomastigotes and amastigotes (IC50 values of 18.7 and 2.0 µg/mL, respectively). Estafietin (1) and 11ßH,13-dihydroestafietin (2) were the most active and selective compounds on L. braziliensis promastigotes (IC50 values of 1.0 and 1.3 µg/mL, respectively). The antiparasitic activity demonstrated by estafietin and some of its derivatives make them promising candidates for the development of effective compounds for the treatment of Chagas disease and leihsmaniasis.


Assuntos
Leishmania braziliensis/efeitos dos fármacos , Sesquiterpenos de Guaiano/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Antiparasitários/química , Antiparasitários/farmacologia , Antiprotozoários/química , Antiprotozoários/farmacologia , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Morte Celular/efeitos dos fármacos , Chlorocebus aethiops , Espectroscopia de Prótons por Ressonância Magnética , Sesquiterpenos de Guaiano/química , Trypanosoma cruzi/crescimento & desenvolvimento , Células Vero
12.
PLoS Negl Trop Dis ; 12(3): e0006384, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29601585

RESUMO

BACKGROUND: Chagas disease, also known as American Trypanosomiasis, is a chronic parasitic disease caused by the flagellated protozoan Trypanosoma cruzi that affects about 8 million people around the world where more than 25 million are at risk of contracting the infection. Despite of being endemic on 21 Latin-American countries, Chagas disease has become a global concern due to migratory movements. Unfortunately, available drugs for the treatment have several limitations and they are generally administered during the chronic phase of the infection, when its efficacy is considered controversial. Thus, prophylactic and/or therapeutic vaccines are emerging as interesting control alternatives. In this work, we proposed Trypanosoma cruzi 80 kDa prolyl oligopeptidase (Tc80) as a new antigen for vaccine development against Chagas disease. METHODOLOGY/PRINCIPAL FINDINGS: In a murine model, we analyzed the immune response triggered by different immunization protocols based on Tc80 and evaluated their ability to confer protection against a challenge with the parasite. Immunized mice developed Tc80-specific antibodies which were able to carry out different functions such as: enzymatic inhibition, neutralization of parasite infection and complement-mediated lysis of trypomastigotes. Furthermore, vaccinated mice elicited strong cell-mediated immunity. Spleen cells from immunized mice proliferated and secreted Th1 cytokines (IL-2, IFN-γ and TNF-α) upon re-stimulation with rTc80. Moreover, we found Tc80-specific polyfunctional CD4 T cells, and cytotoxic T lymphocyte activity against one Tc80 MHC-I peptide. Immunization protocols conferred protection against a T. cruzi lethal challenge. Immunized groups showed a decreased parasitemia and higher survival rate compared with non-immunized control mice. Moreover, during the chronic phase of the infection, immunized mice presented: lower levels of myopathy-linked enzymes, parasite burden, electrocardiographic disorders and inflammatory cells. CONCLUSIONS/SIGNIFICANCE: Considering that an early control of parasite burden and tissue damage might contribute to avoid the progression towards symptomatic forms of chronic Chagas disease, the efficacy of Tc80-based vaccines make this molecule a promising immunogen for a mono or multicomponent vaccine against T. cruzi infection.


Assuntos
Doença de Chagas/prevenção & controle , Vacinas Protozoárias/imunologia , Serina Endopeptidases/imunologia , Trypanosoma cruzi/enzimologia , Trypanosoma cruzi/imunologia , Animais , Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/imunologia , Linfócitos T CD4-Positivos/imunologia , Doença de Chagas/imunologia , Doença de Chagas/parasitologia , Citocinas/imunologia , Imunidade Celular , Camundongos , Camundongos Endogâmicos BALB C , Carga Parasitária , Prolil Oligopeptidases , Proteínas de Protozoários , Vacinas Protozoárias/administração & dosagem , Vacinas Protozoárias/genética , Serina Endopeptidases/genética , Baço/citologia , Baço/imunologia , Linfócitos T Citotóxicos/imunologia , Vacinação
13.
NPJ Vaccines ; 2: 9, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29263868

RESUMO

The parasite Trypanosoma cruzi is the causative agent of Chagas disease, a potentially life-threatening infection that represents a major health problem in Latin America. Several characteristics of this protozoan contribute to the lack of an effective vaccine, among them: its silent invasion mechanism, T. cruzi antigen redundancy and immunodominance without protection. Taking into account these issues, we engineered Traspain, a chimeric antigen tailored to present a multivalent display of domains from key parasitic molecules, combined with stimulation of the STING pathway by c-di-AMP as a novel prophylactic strategy. This formulation proved to be effective for the priming of functional humoral responses and pathogen-specific CD8+ and CD4+ T cells, compatible with a Th1/Th17 bias. Interestingly, vaccine effectiveness assessed across the course of infection, showed a reduction in parasite load and chronic inflammation in different proof of concept assays. In conclusion, this approach represents a promising tool against parasitic chronic infections.

14.
PLoS Negl Trop Dis ; 11(9): e0005929, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28945741

RESUMO

Four sesquiterpene lactones, mikanolide, deoxymikanolide, dihydromikanolide and scandenolide, were isolated by a bioassay-guided fractionation of Mikania variifolia and Mikania micrantha dichloromethane extracts. Mikanolide and deoxymikanolide were the major compounds in both extracts (2.2% and 0.4% for Mikania variifolia and 21.0% and 6.4% for Mikania micrantha respectively, calculated on extract dry weight). Mikanolide, deoxymikanolide and dihydromikanolide were active against Trypanosoma cruzi epimastigotes (50% inhibitory concentrations of 0.7, 0.08 and 2.5 µg/mL, for each compound respectively). These sesquiterpene lactones were also active against the bloodstream trypomastigotes (50% inhibitory concentrations for each compound were 2.1, 1.5 and 0.3 µg/mL, respectively) and against amastigotes (50% inhibitory concentrations for each compound were 4.5, 6.3 and 8.5 µg/mL, respectively). By contrast, scandenolide was not active on Trypanosoma cruzi. Besides, mikanolide and deoxymikanolide were also active on Leishmania braziliensis promastigotes (50% inhibitory concentrations of 5.1 and 11.5 µg/mL, respectively). The four sesquiterpene lactones were tested for their cytotoxicity on THP 1 cells. Deoxymikanolide presented the highest selectivity index for trypomastigotes (SI = 54) and amastigotes (SI = 12.5). In an in vivo model of Trypanosoma cruzi infection, deoxymikanolide was able to decrease the parasitemia and the weight loss associated to the acute phase of the parasite infection. More importantly, while 100% of control mice died by day 22 after receiving a lethal T. cruzi infection, 70% of deoxymikanolide-treated mice survived. We also observed that this compound increased TNF-α and IL-12 production by macrophages, which could contribute to control T. cruzi infection.


Assuntos
Lactonas/farmacologia , Leishmania braziliensis/efeitos dos fármacos , Mikania/química , Extratos Vegetais/farmacologia , Sesquiterpenos/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Doença de Chagas/tratamento farmacológico , Doença de Chagas/parasitologia , Descoberta de Drogas , Interleucina-12/biossíntese , Interleucina-12/imunologia , Lactonas/administração & dosagem , Lactonas/química , Lactonas/isolamento & purificação , Lactonas/uso terapêutico , Estágios do Ciclo de Vida/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Extratos Vegetais/química , Sesquiterpenos/química , Sesquiterpenos/isolamento & purificação , Sesquiterpenos de Germacrano/administração & dosagem , Sesquiterpenos de Germacrano/isolamento & purificação , Sesquiterpenos de Germacrano/farmacologia , Sesquiterpenos de Germacrano/uso terapêutico , Trypanosoma cruzi/isolamento & purificação , Fator de Necrose Tumoral alfa/biossíntese , Fator de Necrose Tumoral alfa/imunologia
15.
Methods Mol Biol ; 1404: 683-695, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27076330

RESUMO

Chagas disease is an important neglected disease affecting thousands of people in the Americas. Novel strategies for prophylactic and therapeutic vaccines against the etiological agent, the intracellular protozoan Trypanosoma cruzi, are urgently needed. Vaccines based on attenuated virus and bacteria as a foreign DNA delivery system represent a strong advantage over naked DNA-based vaccines. Here we describe the use of attenuated Salmonella carrying a eukaryotic expression plasmid encoding a T. cruzi antigen. The main advantages of the methodology are the oral administration of the Salmonella-based vaccine and the induction of a strong humoral and cell-mediated immune response at both mucosal and systemic level, favored by the adjuvant effect elicited by the bacteria pathogen-associated molecular patterns.


Assuntos
Antígenos de Protozoários/genética , Vacinas Protozoárias/genética , Salmonella/genética , Trypanosoma cruzi/imunologia , Vacinas de DNA/genética , Animais , Linhagem Celular , Vetores Genéticos/genética , Transformação Genética , Vacinas Atenuadas/genética
16.
Pharm Biol ; 54(10): 2188-95, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26983579

RESUMO

Context Chagas' disease and leishmaniasis produce significant disability and mortality with great social and economic impact. The genus Stevia (Asteraceae) is a potential source of antiprotozoal compounds. Objective Aerial parts of four Stevia species were screened on Trypanosoma cruzi. Stevia satureiifolia (Lam.) Sch. Bip. var. satureiifolia (Asteraceae) dichloromethane extract was selected for a bioassay-guided fractionation in order to isolate its active compounds. Additionally, the antileishmanial activity and the cytotoxicity of these compounds on mammalian cells were assessed. Materials and methods The dichloromethane extract was fractionated by column chromatography. The isolated compounds were evaluated using concentrations of 0-100 µg/mL on T. cruzi epimastigotes and on Leishmania braziliensis promastigotes for 72 h, on trypomastigotes and amastigotes of T. cruzi for 24 h and 120 h, respectively. The compounds' cytotoxicity (12.5-500 µg/mL) was assessed on Vero cells by the MTT assay. The structure elucidation of each compound was performed by spectroscopic methods and HPLC analysis. Results The dichloromethane extracts of Stevia species showed significant activity on T. cruzi epimastigotes. The flavonoids eupatorin (1.3%), cirsimaritin (1.9%) and 5-desmethylsinensetin (1.5%) were isolated from S. satureiifolia var. satureiifolia extract. Eupatorin and 5-desmethylsinensetin showed IC50 values of 0.2 and 0.4 µg/mL on T. cruzi epimastigotes and 61.8 and 75.1 µg/mL on trypomastigotes, respectively. The flavonoid 5-desmethylsinensetin showed moderate activity against T. cruzi amastigotes (IC50 value = 78.7 µg/mL) and was the most active compound on L. braziliensis promastigotes (IC50 value = 37.0 µg/mL). Neither of the flavonoids showed cytotoxicity on Vero cells, up to a concentration of 500 µg/mL.


Assuntos
Leishmania braziliensis/efeitos dos fármacos , Extratos Vegetais/farmacologia , Stevia , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Sobrevivência Celular/efeitos dos fármacos , Fracionamento Químico , Chlorocebus aethiops , Cromatografia Líquida de Alta Pressão , Relação Dose-Resposta a Droga , Concentração Inibidora 50 , Leishmania braziliensis/crescimento & desenvolvimento , Cloreto de Metileno/química , Testes de Sensibilidade Parasitária , Fitoterapia , Componentes Aéreos da Planta , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/toxicidade , Plantas Medicinais , Solventes/química , Stevia/química , Tripanossomicidas/isolamento & purificação , Tripanossomicidas/toxicidade , Trypanosoma cruzi/crescimento & desenvolvimento , Células Vero
17.
Hum Vaccin Immunother ; 12(2): 438-50, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26312947

RESUMO

Therapeutic vaccine research and development are especially important in Chagas disease considering the characteristics of the chronic infection and the number of people in the Americas living with a parasite infection for decades. We have previously reported the efficacy of attenuated Salmonella enterica (S) carrying plasmid encoding cruzipain (SCz) to protect against Trypanosoma cruzi infection. In the present work we investigated whether Cz DNA vaccine immunotherapy could be effective in controlling an ongoing T. cruzi infection in mice. We here report the intramuscular administration of naked Cz DNA or the oral administration of Salmonella as Cz DNA delivery system as therapeutic vaccines in mice during acute or chronic infection. The coadministration of a plasmid encoding GM-CSF improved vaccine performance, indicating that the stimulation of innate immune cells is needed in the event of an ongoing infection. These therapeutic vaccines were able to address the response to a protective and sustained Th1 biased profile not only against Cz but also against a variety of parasite antigens. The combined therapeutic vaccine during the chronic phase of infection prevents tissue pathology as shown by a reduced level of enzyme activity characteristic of tissue damage and a tissue status compatible with normal tissue. The obtained results suggest that immunotherapy with Cz and GM-CSF DNAs, either alone or in combination with other drug treatments, may represent a promising alternative for Chagas disease therapy.


Assuntos
Anticorpos Antiprotozoários/sangue , Doença de Chagas/tratamento farmacológico , Cisteína Endopeptidases/uso terapêutico , DNA/uso terapêutico , Fator Estimulador de Colônias de Granulócitos e Macrófagos/genética , Imunoterapia/métodos , Vacinas Protozoárias/imunologia , Trypanosoma cruzi/imunologia , Animais , Anticorpos Antiprotozoários/imunologia , Antígenos de Protozoários/imunologia , Doença de Chagas/parasitologia , Combinação de Medicamentos , Feminino , Imunidade Inata/genética , Imunidade Inata/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Camundongos , Camundongos Endogâmicos C3H , Parasitemia/tratamento farmacológico , Parasitemia/prevenção & controle , Plasmídeos/genética , Plasmídeos/uso terapêutico , Proteínas de Protozoários , Salmonella/genética , Células Th1/imunologia , Trypanosoma cruzi/efeitos dos fármacos , Vacinas de DNA/genética , Vacinas de DNA/imunologia
18.
J Infect Dis ; 211(5): 698-707, 2015 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-25160983

RESUMO

We have reported that attenuated Salmonella (S) carrying plasmids encoding the cysteine protease cruzipain (Cz) protects against Trypanosoma cruzi infection. Here, we determined whether immunoprotection could be improved by the oral coadministration of 3 Salmonella carrying the plasmids that encode the antigens Cz, Tc52, and Tc24. SCz+STc52+STc24-immunized mice presented an increased antibody response against each antigen compared with those in the single antigen-immunized groups, as well as higher trypomastigotes antibody-mediated lyses and cell invasion inhibition compared with controls. SCz+STc52+STc24-immunized and -challenged mice rendered lower parasitemia. Weight loss after infection was detected in all mice except those in the SCz+STc52+STc24 group. Moreover, cardiomyopathy-associated enzyme activity was significantly lower in SCz+STc24+STc52-immunized mice compared with controls. Few or no abnormalities were found in muscle tissues of SCz+STc24+STc52-immunized mice, whereas controls presented with inflammatory foci, necrosis, and amastigote nests. We conclude that a multicomponent approach that targets several invasion and metabolic mechanisms improves protection compared with single-component vaccines.


Assuntos
Doença de Chagas/prevenção & controle , Portadores de Fármacos , Vacinas Protozoárias/imunologia , Salmonella/genética , Trypanosoma cruzi/imunologia , Vacinas de DNA/imunologia , Animais , Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/genética , Antígenos de Protozoários/imunologia , Peso Corporal , Doença de Chagas/parasitologia , Doença de Chagas/patologia , Modelos Animais de Doenças , Feminino , Camundongos Endogâmicos C3H , Miocárdio/patologia , Parasitemia/prevenção & controle , Vacinas Protozoárias/administração & dosagem , Vacinas Protozoárias/genética , Resultado do Tratamento , Trypanosoma cruzi/genética , Vacinas de DNA/administração & dosagem , Vacinas de DNA/genética
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