RESUMEN
Chagas disease (CD) is a neglected disease caused by the protozoan Trypanosoma cruzi. The two drugs used in the treatment schedules exhibit adverse effects and severe toxicity. Thus, searching for new antitrypanosomal agents is urgent to provide improved treatments to those affected by this disease. 5-Nitrofuran-isoxazole analogs were synthesized by cycloaddition reactions [3+2] between chloro-oximes and acetylenes in satisfactory yields. We analyzed the structure-activity relationship of the analogs based on Hammett's and Hansch's parameters. The 5-nitrofuran-isoxazole analogs exhibited relevant in vitro antitrypanosomal activity against the amastigote forms of T. cruzi. Analog 7s was the trending hit of the series, showing an IC50 value of 40 nM and a selectivity index of 132.50. A possible explanation for this result may be the presence of an electrophile near the isoxazole core. Moreover, the most active analogs proved to act as an in vitro substrate of type I nitroreductase rather than the cruzain, enzymes commonly investigated in molecular target studies of CD drug discovery. These findings suggest that 5-nitrofuran-isoxazole analogs are promising in the studies of agents for CD treatment.
Asunto(s)
Nitrofuranos , Tripanocidas , Trypanosoma cruzi , Relación Estructura-Actividad , Isoxazoles/farmacología , Isoxazoles/química , Reposicionamiento de Medicamentos , Nitrofuranos/farmacología , Nitrofuranos/química , Tripanocidas/farmacología , Tripanocidas/químicaRESUMEN
Breast cancer has the highest incidence and mortality in females, while prostate cancer has the second-highest incidence in males. Studies have shown that compounds from Brazilian green propolis have antitumor activities and can selectively inhibit the AKR1C3 enzyme, overexpressed in hormone-dependent prostate and breast tumors. Thus, in an attempt to develop new cytotoxic inhibitors against these cancers, three prenylated compounds, artepillin C, drupanin and baccharin, were isolated from green propolis to synthesize new derivatives via coupling reactions with different amino acids. All obtained derivatives were submitted to antiproliferative assays against four cancer cells (MCF-7, MDA MB-231, PC-3, and DU145) and two normal cell lines (MCF-10A and PNT-2) to evaluate their cytotoxicity. In general, the best activity was observed for compound6e, derived from drupanin, which exhibited half-maximal inhibitory concentration (IC50) of 9.6 ± 3 µM and selectivity index (SI) of 5.5 against MCF-7 cells.In silicostudies demonstrated that these derivatives present coherent docking interactions and binding modes against AKR1C3, which might represent a possible mechanism of inhibition in MCF-7 cells.
Asunto(s)
Aminoácidos/farmacología , Antineoplásicos Fitogénicos/farmacología , Cinamatos/farmacología , Fenilpropionatos/farmacología , Própolis/química , Tricotecenos/farmacología , Aminoácidos/análisis , Aminoácidos/síntesis química , Antineoplásicos Fitogénicos/análisis , Antineoplásicos Fitogénicos/síntesis química , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Cinamatos/análisis , Cinamatos/síntesis química , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Estructura Molecular , Fenilpropionatos/análisis , Fenilpropionatos/síntesis química , Própolis/análisis , Própolis/síntesis química , Própolis/farmacología , Relación Estructura-Actividad , Tricotecenos/análisis , Tricotecenos/síntesis químicaRESUMEN
Despite the serious public health problems caused by Chagas disease in several countries, the available therapy remains with only two drugs that are poorly active during the chronic phase of the disease in addition to having severe side effects. In search of new trypanocidal agents, herein we describe the synthesis and biological evaluation of eleven new 1,6-diphenyl-1H-pyrazolo[3,4-b]pyridine compounds containing the carbohydrazide or the 2,3-dihydro-1,3,4-oxadiazole moieties. Two of them showed promising in vitro activity against amastigote forms of T. cruzi and were evaluated in vivo in male BALB/c mice infected with T. cruzi Y strain. Our results suggest that the substitution at the C-2 position of the phenyl group connected to the carbohydrazide or to the 2,3-dihydro-1,3,4-oxadiazole moieties plays an important role in the trypanocidal activity of this class of compounds. Moreover, the compound containing the 2,3-dihydro-1,3,4-oxadiazole moiety has demonstrated more favorable structural requirements for in vivo activity than its carbohydrazide analog.
Asunto(s)
Enfermedad de Chagas/tratamiento farmacológico , Pirazoles/farmacología , Piridinas/farmacología , Tripanocidas/farmacología , Trypanosoma cruzi/efectos de los fármacos , Animales , Línea Celular , Supervivencia Celular/efectos de los fármacos , Enfermedad de Chagas/patología , Relación Dosis-Respuesta a Droga , Masculino , Ratones , Ratones Endogámicos BALB C , Estructura Molecular , Pruebas de Sensibilidad Parasitaria , Pirazoles/síntesis química , Pirazoles/química , Piridinas/síntesis química , Piridinas/química , Relación Estructura-Actividad , Tripanocidas/síntesis química , Tripanocidas/químicaRESUMEN
Cardiac damage during the acute phase of Chagas disease (CD) is associated with an increase in pro-inflammatory markers and oxidative stress. Melatonin (MEL) has emerged as a promising therapy for CD due to its antioxidant and immunomodulatory properties; however, the protective action of MEL in the cardiac tissue, as well as its direct action on the parasite cycle, is not fully understood. We investigated the effects of MEL on heart parasitism in mice infected with Trypanosoma cruzi and also its effects on the parasitic proliferation in vitro. Our in vivo study showed that MEL reduced circulating parasitemia load, but did not control tissue (heart, liver, and spleen) parasitism in mice. MEL did not prevent the redox imbalance in the left ventricle of infected mice. Our in vitro findings showed that MEL did not inhibit parasites replication within cells, but rather increased their release from cells. MEL did not control parasitism load in the heart or prevent the cardiac redox imbalance induced by acute T. cruzi infection. The hormone controlled the circulating parasitic load, but within cells MEL accelerated parasitic release, a response that can be harmful.
Asunto(s)
Melatonina , Trypanosoma cruzi , Animales , Enfermedad de Chagas , Corazón , RatonesRESUMEN
Chagas disease affects several countries around the world with health and sanitation problems. Cysteine proteases are essential for the virulence and replication of the Trypanosoma cruzi, being modulated by dipeptidyl nitriles and derivatives. Here, four dipeptidyl nitrile derivatives were assayed in three T. cruzi morphologies and two strains (Tulahuen and Y) using a set of assays: (i) analysis of the inhibitory activity against cysteine proteases; (ii) determination of the cytotoxic activity and selectivity index; (iii) verification of the inhibition of the trypomastigote invasion in the host cell. These compounds could inhibit the activity of cysteine proteases using the selective substrate Z-FR-MCA for the trypomastigote lysate and extracellular amastigotes. Interestingly, these compounds did not present relevant enzymatic inhibition for the epimastigote lysate. Most of the substances were also cytotoxic and selective against the trypomastigotes and intracellular amastigotes. The best compound of the series (Neq0662) could reduce the enzymatic activity of the cysteine proteases for the trypomastigotes and amastigotes. It was equipotent to the benznidazole drug in the cytotoxic studies using these two parasite forms. Neq0662 was also selective for the parasite, and it inhibited the invasion of the mammalian host cell in all conditions tested at 10 µM. The stereochemistry of the trifluoromethyl group was an important factor for the bioactivity when the two diastereomers (Neq0662 and Neq0663) were compared. All-in-all, these results indicate that these compounds could move further in the drug development stage because of its promising bioactive profile.
Asunto(s)
Inhibidores de Cisteína Proteinasa/farmacología , Nitrilos/farmacología , Trypanosoma cruzi/efectos de los fármacos , Análisis de Varianza , Animales , Antiparasitarios/química , Antiparasitarios/farmacología , Área Bajo la Curva , Línea Celular , Supervivencia Celular , Inhibidores de Cisteína Proteinasa/química , Inhibidores de Cisteína Proteinasa/toxicidad , Haplorrinos , Riñón/citología , Nitrilos/química , Proteolisis , Estereoisomerismo , Sales de Tetrazolio , Tiazoles , Trypanosoma cruzi/enzimología , Trypanosoma cruzi/crecimiento & desarrollo , Trypanosoma cruzi/metabolismoRESUMEN
A series of 16 "3 + 2" mixed-ligand complexes of the general composition [ReO(L1)(L2)] (H2L1a-H2L1d = tridentate thiosemicarbazones having a phenyl group with 4-H, 4-F, 3,5-di-F, and 4-CF3 substituents; HL2a-HL2d = bidentate N,N-diethyl-N'-benzoylthioureas with 4-H, 4-F, 3,5-di-F, and 4-CF3 substituents at the benzoyl groups) have been synthesized and characterized by spectroscopic methods and X-ray diffraction. Irrespective of the individual fluorine substitution, the complexes are stable and possess the same general structure. Some systematic electronic effects of the fluorine-substitution patterns of the ligands have been found on the 13C NMR chemical shifts of the N-CâN carbon atoms of the {L1}2- and the CâO carbon atoms of the {L2}- ligands. Antiparasitic properties of the rhenium complexes have been tested against epimastigotes and trypomastigotes forms of two Trypanosoma cruzi strains and the amastigotes form of one of them. The results of this study indicate that the activity of the rhenium complexes can clearly be modulated by fluorine substitution of their ligands. Some of the fluorinated compounds show a high activity against epimastigotes and trypomastigotes forms of the parasites. Reactions between (NBu4)[TcOCl4] and two representatives of the fluorinated ligands (H2L1b, 4-F-substituted, and H2L1c, 4-CF3-substituted) form stable complexes of the composition [TcOCl(L1b)] and [TcOCl(L1c)]. Subsequent reactions of these products with HL2b (4-F-substituted) give the corresponding [TcO(L1)(L2)] mixed-ligand complexes. Also, the technetium compounds are stable as solids and in solutions and have structures corresponding to those of their rhenium analogues.
Asunto(s)
Complejos de Coordinación/farmacología , Halogenación , Renio/farmacología , Tiosemicarbazonas/farmacología , Tiourea/farmacología , Tripanocidas/farmacología , Trypanosoma cruzi/efectos de los fármacos , Animales , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Complejos de Coordinación/síntesis química , Complejos de Coordinación/química , Cristalografía por Rayos X , Haplorrinos , Ligandos , Modelos Moleculares , Estructura Molecular , Pruebas de Sensibilidad Parasitaria , Renio/química , Tiosemicarbazonas/química , Tiourea/química , Tripanocidas/síntesis química , Tripanocidas/químicaRESUMEN
Cysteine proteases are involved in critical cell processes to the protozoa from Leishmania genus, and their inhibition is a therapeutic alternative to treat the disease. In this work, derivatives of dipeptidyl nitriles acting as reversible covalent inhibitors of cysteine proteases were studied as cytostatic agents. The proteolytic activity inside the living and lysed parasite cells was quantified using a selective substrate for cysteine proteases (Z-FR-MCA) from Leishmania amazonensis and L. infantum. The overall proteolytic activity of intact cells and even cell extracts was only marginally affected at high concentrations, with the observation of cytostatic activity and cell cycle arrest of promastigotes. However, the cytotoxic effects were only observed for infected J774 macrophages, which impaired further analysis of the amastigote infection. Therefore, the proteolytic inhibition in intact L. amazonensis and L. infantum promastigotes had no relationship to the cytostatic activity, which emphasizes that these dipeptidyl nitriles act through another mechanism of action.
Asunto(s)
Antiprotozoarios/farmacología , Inhibidores de Cisteína Proteinasa/farmacología , Citostáticos/farmacología , Leishmania infantum/efectos de los fármacos , Leishmania mexicana/efectos de los fármacos , Nitrilos/farmacología , Animales , Antiprotozoarios/química , Línea Celular , Inhibidores de Cisteína Proteinasa/química , Citostáticos/química , Fibroblastos/efectos de los fármacos , Citometría de Flujo , Leishmania infantum/enzimología , Leishmania mexicana/enzimología , Macrófagos/efectos de los fármacos , Ratones , Nitrilos/químicaRESUMEN
The acute phase of Chagas disease (CD) is characterized by high parasitic proliferation and intense inflammation, exacerbating the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS). These reactive molecules are also increased by the metabolism of the nitroheterocyclic compounds benznidazole (BZ) and nifurtimox, the only drugs available for the treatment of CD. This oxidative environment, associated with the intracellular multiplication of Trypanosoma cruzi, leads to tissue destruction, triggering the pathogenic process. Both drugs have limited efficacy and serious side effects, which demonstrates the need to seek alternative therapies. Due to the difficulty in developing new drugs, reviewing therapeutic regimens appears advantageous, and the use of BZ in low doses associated with antioxidants, such as ascorbic acid (AA), would be a valid alternative to attenuate oxidative stress. In our in vivo studies, mice receiving the combination of 7.14 mg/kg of body weight/day AA and 10 mg/kg/day BZ10 (AA+BZ10) showed a reduction in parasitemia that was more effective than that with those receiving BZ or AA alone. The combined treatment was effective in decreasing intracellular ROS and lipid peroxidation in cardiac tissue. Histological and PCR analyzes showed that AA also reduced the cardiac parasitism. However, the greatest benefit was seen in AA+BZ10 group, since cardiac inflammation was significantly reduced. In addition, the combined therapy prevented the hepatic damage induced by the infection. Our findings suggest that AA combined with a low dose of BZ may improve the trypanocidal activity and attenuate the toxic effects of BZ. The decrease in oxidative damage and inflammation observed in mice treated with AA+BZ10 could result in increased cardioprotection.
Asunto(s)
Ácido Ascórbico/farmacología , Enfermedad de Chagas/tratamiento farmacológico , Nitroimidazoles/farmacología , Animales , Antioxidantes/metabolismo , Enfermedad de Chagas/parasitología , Quimioterapia Combinada/métodos , Inflamación/tratamiento farmacológico , Inflamación/parasitología , Peroxidación de Lípido/efectos de los fármacos , Masculino , Ratones , Oxidación-Reducción/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Tripanocidas/farmacología , Trypanosoma cruzi/efectos de los fármacosRESUMEN
Over a hundred years after the discovery of Chagas disease, this ailment continues to affect thousands of people. For more than 40 years, only two drugs have been available to treat it. Ursolic acid is a naturally occurring terpene that has shown a good trypanocidal action. However, the hydrophobicity of this compound presents a challenge for the development of proper delivery systems. Nanostructured systems are a prominent in delivering lipophilic drugs. Thus, a nanoemulsion containing ursolic acid was developed and had its trypanocidal activity and cytotoxicity evaluated. Pseudo-ternary phase diagrams and hydrophilic-lipophilic balance (HLB) system were used in the development. The system was stable throughout 90 days of testing, as evidenced by turbidimetry analysis and measurements of the droplet size (57.3 nm) and polydispersity index (0.24). Fourier transform infrared spectroscopy and mass spectrometry evidenced drug's integrity in the formulation. An in vitro dissolution profile showed 75% of ursolic acid release after 5 min from the nanoemulsion into the alkaline dissolution medium, while only 20% could be released from a physical mixture after 2 h. Trypanocidal activity and cytotoxicity were evaluated on the CL Brener strain and LLC-MK2 (monkey kidney) fibroblast by chlorophenol red-ß-D-galactoside (CPRG) method. Biological studies showed that the developed formulation was nontoxic and effective against replicant forms of the parasite. A stable and efficient nanoemulsion could be developed to improve the delivery of a promising drug to treat a threatening illness such as Chagas disease.
Asunto(s)
Sistemas de Liberación de Medicamentos , Triterpenos/administración & dosificación , Tripanocidas/administración & dosificación , Enfermedad de Chagas/tratamiento farmacológico , Estabilidad de Medicamentos , Emulsiones , Nanoestructuras/química , Solubilidad , Triterpenos/química , Triterpenos/farmacología , Tripanocidas/farmacología , Ácido UrsólicoRESUMEN
Herein, we report the synthesis of 12 new naphthoquinone derivatives, 6 substituted 1,4-naphthoquinones and 6 heterocycle-fused naphthoquinones, as well as evaluation of their trypanocidal and leishmanicidal activities. Compounds 11a and 13a were active against the amastigote stage of T. cruzi and showed low cytotoxic effects. With respect to leishmanicidal assays, all compounds were inactive against the promastigote stages of L. chagasi and L. braziliensis.
Asunto(s)
Antiprotozoarios/química , Leishmania/efectos de los fármacos , Naftoquinonas/química , Tripanocidas/química , Animales , Antiprotozoarios/farmacología , Línea Celular , Humanos , Espectroscopía de Resonancia Magnética , Naftoquinonas/farmacología , Espectrometría de Masa por Ionización de Electrospray , Tripanocidas/farmacologíaRESUMEN
There is an urgent need to develop new, safer, and more effective drugs against Chagas disease (CD) as well as related kinetoplastid diseases. Targeting and inhibiting the Trypanosoma cruzi proteasome has emerged as a promising therapeutic approach in this context. To expand the chemical space for this class of inhibitors, we performed virtual screening campaigns with emphasis on shape-based similarity and ADMET prioritization. We describe the ideation and application of robustly validated shape queries for these campaigns, which furnished 44 compounds for biological evaluation. Five hit compounds demonstrated in vitro antitrypanosomal activity by potential inhibition of T. cruzi proteasome and notable chemical diversities, particularly, LCQFTC11. Structural insights were achieved by homology modeling, sequence/structure alignment, proteasome-species comparison, docking, molecular dynamics, and MMGBSA binding affinity estimations. These methods confirmed key interactions as well as the stability of LCQFTC11 at the ß4/ß5 subunits' binding site of the T. cruzi proteasome, consistent with known inhibitors. Our results warrant future assay confirmation of our hit as a T. cruzi proteasome inhibitor. Importantly, we also shed light into dynamic details for a proteasome inhibition mechanism that shall be further investigated. We expect to contribute to the development of viable CD drug candidates through such a relevant approach.
RESUMEN
Old Yellow Enzymes (OYEs) are flavin-dependent redox enzymes that promote the asymmetric reduction of activated alkenes. Due to the high importance of flavoenzymes in the metabolism of organisms, the interaction between OYEs from the parasites Trypanosoma cruzi and Leishmania braziliensis and three diterpene icetexanes (brussonol and two analogs), were evaluated in the present study, and differences in the binding mechanism and inhibition capacity of these molecules were examined. Although the aforementioned compounds showed poor and negligible activities against T. cruzi and L. braziliensis cells, respectively, the experiments with the purified enzymes indicated that the interaction occurs by divergent mechanisms. Overall, the ligands' inhibitory effect depends on their accessibility to the N5 position of the flavin's isoalloxazine ring. The results also indicated that the OYEs found in both parasites share structural similarities and showed affinities for the diterpene icetexanes in the same range. Nevertheless, the interaction between OYEs and ligands is directed by enthalpy and/or entropy in distinct ways. In conclusion, the binding site of both OYEs exhibits remarkable plasticity, and a large range of different molecules, including that can be substrates and inhibitors, can bind this site. This plasticity should be considered in drug design using OYE as a target.
Asunto(s)
Enfermedad de Chagas , Leishmania braziliensis , Trypanosoma cruzi , Humanos , NADPH Deshidrogenasa/química , NADPH Deshidrogenasa/farmacología , Enfermedad de Chagas/parasitología , Flavinas/farmacologíaRESUMEN
A series of 28 compounds, 3-nitro-1H-1,2,4-triazole, were synthesized by click-chemistry with diverse substitution patterns using medicinal chemistry approaches, such as bioisosterism, Craig-plot, and the Topliss set with excellent yields. Overall, the analogs demonstrated relevant in vitro antitrypanosomatid activity. Analog 15g (R1 = 4-OCF3-Ph, IC50 = 0.09 µM, SI = >555.5) exhibited an outstanding antichagasic activity (Trypanosoma cruzi, Tulahuen LacZ strain) 68-fold more active than benznidazole (BZN, IC50 = 6.15 µM, SI = >8.13) with relevant selectivity index, and suitable LipE = 5.31. 15g was considered an appropriate substrate for the type I nitro reductases (TcNTR I), contributing to a likely potential mechanism of action for antichagasic activity. Finally, 15g showed nonmutagenic potential against Salmonella typhimurium strains (TA98, TA100, and TA102). Therefore, 3-nitro-1H-1,2,4-triazole 15g is a promising antitrypanosomatid candidate for in vivo studies.
Asunto(s)
Enfermedad de Chagas , Leishmaniasis , Tripanocidas , Trypanosoma cruzi , Humanos , Relación Estructura-Actividad , Enfermedad de Chagas/tratamiento farmacológico , Triazoles/químicaRESUMEN
Reduction in the parasitemic levels of the Y strain of Trypanosoma cruzi in mice treated with oral or intraperitoneal ursolic (UA) and oleanolic (OA) acids was evaluated during the acute phase of Chagas' disease. Oral administration of UA and OA (50mg/kg/day) provided the most significant reduction in the parasitemic peak, while intraperitoneal administration of UA and OA did not significantly affect the biological activity of the Y strain of T. cruzi. Interleukin levels in mice treated by the intraperitoneal route were compared to untreated chagasic mice. Reduced γ-IFN levels and enhanced IL-10 concentrations potentially explain the exacerbated parasitemia. Our data suggests an immunosuppressive effect for UA and OA, which could interfere with host control of parasitemia. Optimal results were achieved with oral administration. This observation may be explained by the low intestinal absorption of UA and OA, could cause a reduced immune response and promote parasite control. Taken together, these data demonstrate that triterpenes could be interesting compounds to develop therapeutically for the treatment of Chagas' disease.
Asunto(s)
Antiinfecciosos/uso terapéutico , Enfermedad de Chagas/tratamiento farmacológico , Ácido Oleanólico/uso terapéutico , Triterpenos/uso terapéutico , Enfermedad Aguda , Administración Oral , Animales , Antiinfecciosos/administración & dosificación , Antiinfecciosos/química , Enfermedad de Chagas/inmunología , Modelos Animales de Enfermedad , Infusiones Parenterales , Interferón gamma/sangre , Interleucina-10/sangre , Masculino , Melastomataceae/química , Ratones , Ratones Endogámicos BALB C , Nitroimidazoles/administración & dosificación , Nitroimidazoles/uso terapéutico , Ácido Oleanólico/administración & dosificación , Ácido Oleanólico/química , Parasitemia/tratamiento farmacológico , Parasitemia/inmunología , Distribución Aleatoria , Triterpenos/administración & dosificación , Triterpenos/química , Tripanocidas/administración & dosificación , Tripanocidas/uso terapéutico , Ácido UrsólicoRESUMEN
Even though the Chagas' disease, caused by the protozoan Trypanosoma cruzi, was described 100years ago by Carlos Chagas, it still represents a major public health concern and is found in 18 developing countries in South and Central America. In Brazil, Benznidazole (Rochagan) is the only drug with trypanocidal activity available in the market, despite its several side effects and limited efficacy in the chronic phase of the infection. In view of the need for new substances displaying biological activity against T. cruzi, there has been growing interest in research toward the attainment of compounds capable of acting on the parasite while being devoid of serious side effects. In this context, this study aims to evaluate the in vivo therapeutic activity of dibenzylbutyrolactone lignans (-)-cubebin and (-)-hinokinin during the acute phase of infection by T. cruzi. As a study criterion, animals with acute parasitemia were investigated by tissue morphometric analysis. There was significant parasitemia reduction in the groups of animals treated with (-)-cubebin or (-)-hinokin oral administration, compared to the negative control. Values close to those of the uninfected control were found in the groups treated with (-)-cubebin and (-)-hinokinin via kariometry, showing that there was positive cellular response compared to the infected control.
Asunto(s)
4-Butirolactona/análogos & derivados , Enfermedad de Chagas/tratamiento farmacológico , Dioxoles/uso terapéutico , Lignanos/uso terapéutico , Tripanocidas/farmacología , Tripanocidas/uso terapéutico , Trypanosoma cruzi/efectos de los fármacos , 4-Butirolactona/química , 4-Butirolactona/farmacología , 4-Butirolactona/uso terapéutico , Animales , Benzodioxoles , Dioxoles/química , Dioxoles/farmacología , Lignanos/química , Lignanos/farmacología , Masculino , Ratones , Ratones Endogámicos BALB C , Nitroimidazoles/farmacología , Nitroimidazoles/uso terapéutico , Piper/química , Tripanocidas/químicaRESUMEN
Nifurtimox and benznidazole, medications currently used for the treatment of the Chagas disease, are not always successful. We determine whether (-)-cubebin and (-)-hinokinin could be used as alternative drugs for the treatment of parasitic infections by Trypanosoma cruzi. To this end, male BALB/c mice were treated with both drugs, and the nuclear parameters (largest diameter, smallest diameter, and perimeter) were determined from slides prepared from the spleen, liver, and heart. The cytotoxicity of the substances was determined after 24-h treatment. Results revealed increased cell nuclei in untreated infected animals as compared to uninfected mice. The values obtained for infected animals treated with (-)-cubebin and (-)-hinokinin were close to those observed for uninfected mice. For the spleen, perimeter values of 10.85 µm (p < 0.01) and 10.90 µm (p < 0.05) were obtained for mice treated with (-)-cubebin 50 mg/kg and (-)-hinokinin 20 mg/kg, respectively, whereas untreated infected animals furnished a perimeter of 11.76 µm. As for the liver, perimeter values of 19.06 µm (p < 0.01) and 18.61 µm (p < 0.001) were achieved for mice treated with (-)-cubebin 50 mg/kg and (-)-hinokinin 20 mg/kg, respectively, whereas a perimeter of 18.54 µm was obtained for untreated infected animals. The cytotoxicity assays demonstrated that (-)-cubebin and (-)-hinokinin does not display toxicity. Therefore, (-)-cubebin and (-)-hinokinin are promising therapeutic agents and could be used in future clinical studies concerning treatment of the Chagas disease. Even if the karyometry is not used frequently, it can complement other methods, such as PCR, and furthermore, it is a simple method which is easily possible to analyze the activity of substances in the tissues of treated infected animals compared to uninfected animals.
Asunto(s)
4-Butirolactona/análogos & derivados , Enfermedad de Chagas/tratamiento farmacológico , Enfermedad de Chagas/patología , Dioxoles/administración & dosificación , Lignanos/administración & dosificación , 4-Butirolactona/administración & dosificación , 4-Butirolactona/efectos adversos , Animales , Antiprotozoarios/administración & dosificación , Antiprotozoarios/efectos adversos , Benzodioxoles , Biometría , Línea Celular , Enfermedad de Chagas/parasitología , Dioxoles/efectos adversos , Modelos Animales de Enfermedad , Fibroblastos/efectos de los fármacos , Cariotipificación , Lignanos/efectos adversos , Hígado/patología , Macaca mulatta , Masculino , Ratones , Ratones Endogámicos BALB C , Bazo/patología , Trypanosoma cruzi/patogenicidadRESUMEN
Chagas disease is a well-known Neglected Tropical Disease, mostly endemic in continental Latin America, but that has spread to North America and Europe. Unfortunately, current treatments against such disease are ineffective and produce known and undesirable side effects. To find novel effective drug candidates to treat Chagas disease, we uniquely explore the Trypanosoma cruzi proteasome as a recent biological target and, also, apply drug repurposing through different computational methodologies. For this, we initially applied protein homology modeling to build a robust model of proteasome ß4/ß5 subunits, since there is no crystallographic structure of this target. Then, we used it on a drug repurposing via a virtual screening campaign starting with more than 8,000 drugs and including the methodologies: ligand-based similarity, toxicity predictions, and molecular docking. Three drugs were selected concerning their favorable interactions at the protein binding site and subsequently submitted to molecular dynamics simulations, which allowed us to elucidate their behavior and compare such theoretical results with experimental ones, obtained in biological assays also described in this paper.Communicated by Ramaswamy H. Sarma.
Asunto(s)
Enfermedad de Chagas , Trypanosoma cruzi , Humanos , Simulación de Dinámica Molecular , Complejo de la Endopetidasa Proteasomal/metabolismo , Complejo de la Endopetidasa Proteasomal/farmacología , Complejo de la Endopetidasa Proteasomal/uso terapéutico , Simulación del Acoplamiento Molecular , Ligandos , Enfermedad de Chagas/tratamiento farmacológicoRESUMEN
p-Coumaric acid is derived from cinnamic acid and is one of the major compounds in the Brazilian green propolis extract. Studies have shown that both p-coumaric acid and cinnamic acid have promising antiproliferative effects. In this context, aiming to increase the complexity of these active natural products and their activities, we performed coupling reactions with propargylamine and benzylamine, as well as with threonine, phenylalanine and lysine amino acids, aiming to enhance their antiproliferative effects towards the hormone-dependent breast cancer MCF-7 cells. Overall, the p-coumaric acid coupling with L-threonine amino acid (compound 15) had the best selectivity index (SI = 5.1), with half-maximal inhibitory concentration of 39.6 ± 1 µM, showing a high selectivity against hormone-dependent breast cancer cell lines MCF-7 and low cytotoxicity against the normal breast cell lines MCF-10A. Thus, this new natural product derivative may represent a prototype for the future development of antiproliferative agents, especially against hormone-dependent breast cancer.
Asunto(s)
Antineoplásicos , Neoplasias de la Mama , Humanos , Femenino , Ácidos Cumáricos/farmacología , Células MCF-7 , Antineoplásicos/química , Neoplasias de la Mama/tratamiento farmacológico , Hormonas/farmacología , Hormonas/uso terapéutico , Proliferación Celular , Línea Celular TumoralRESUMEN
Trypanosoma cruzi, the etiological agent of Chagas disease, relies on finely coordinated epigenetic regulation during the transition between hosts. Herein we targeted the silent information regulator 2 (Sir2) enzyme, a NAD+-dependent class III histone deacetylase, to interfere with the parasites' cell cycle. A combination of molecular modelling with on-target experimental validation was used to discover new inhibitors from commercially available compound libraries. We selected six inhibitors from the virtual screening, which were validated on the recombinant Sir2 enzyme. The most potent inhibitor (CDMS-01, IC50 = 40 µM) was chosen as a potential lead compound.
RESUMEN
Chagas disease and leishmaniasis are neglected diseases of high priority as a public health problem. Pharmacotherapy is based on the administration of a few drugs, which exhibit hazardous adverse effects and toxicity to the patients. Thus, the search for new antitrypanosomatid drugs is imperative to overcome the limitations of the treatments. In this work, 46 2-nitroimidazole 3,5-disubstituted isoxazole compounds were synthesized in good yields by [3 + 2] cycloaddition reaction between terminal acetylene (propargyl-2-nitroimidazole) and chloro-oximes. The compounds were non-toxic to LLC-MK2 cells. Compounds 30, 35, and 44 showed in vitro antichagasic activity, 15-fold, 12-fold, and 10-fold, respectively, more active than benznidazole (BZN). Compounds 30, 35, 44, 45, 53, and 61 acted as substrates for the TcNTR enzyme, indicating that this might be one of the mechanisms of action involved in their antiparasitic activity. Piperazine series and 4-monosubstituted compounds were potent against T. cruzi parasites. Besides the in vitro activity observed in compound 45, the in vivo assay showed that the compound only reduced the parasitemia levels by the seventh-day post-infection (77%, pâ¯>â¯0.001) compared to the control group. However, 45 significantly reduced the parasite load in cardiac tissue (pâ¯<â¯0.01) 11 days post-infection. Compounds 49, 52, and 54 showed antileishmanial activity against intracellular amastigotes of Leishmania (L.) amazonensis at the same range as amphotericin B. These findings highlight the antitrypanosomatid properties of 2-nitroimidazole 3,5-disubstituted isoxazole compounds and the possibility in using them as antitrypanosomatid agents in further studies.