RESUMEN

Asymptomatic Leishmania infantum, when associated with HIV, can become severe and potentially fatal. In this co-infection, the worst prognosis may be influenced by the host's immunological aspects, which are crucial in determining susceptibility. Chemokines play an important role in this process by influencing the cellular composition at affected sites and impacting the disease's outcome. Therefore, the aim of this study was to evaluate proinflammatory chemokines in HIV patients with the asymptomatic L. infantum infection. In this cross-sectional study, the levels of CCL2, CCL5, CXCL8, MIG, and IP-10 were measured in 160 serum samples from co-infected patients (n = 53), patients with HIV (n = 90), and negative controls (n = 17). Quantification was determined by flow cytometry. The obtained data were statistically analyzed using the Kruskal-Wallis test, followed by the Dunn's post-test and the Spearman's correlation coefficient. Significance was set at p < 0.05. The chemokines CCL2, CCL5, MIG, and IP-10 exhibited higher levels in the HIV group compared to co-infection. However, the elevated levels of all these chemokines and their increased connectivity in co-infected patients appear to be important in identifying proinflammatory immune responses associated with the asymptomatic condition. Furthermore, a weak negative correlation was observed between higher levels of CXCL8 and lower viral loads in co-infected patients.

RESUMEN

Cutaneous Leishmaniasis (CL) is a Neglected Tropical Disease characterized by skin ulcers caused by Leishmania spp. protozoans and there is no safe and effective vaccine to reduce its negative consequences. In a previous work by our group, we identified T cell epitopes of Leishmania (Viannia) braziliensis which stimulated patients' T cells in vitro. In the present work, the peptides were tested as two pools for their ability to rescue memory T cells during natural infection by Leishmania. We analyzed the frequency of central memory (TCM, CD45RA-CD62L+) and effector memory (TEM, CD45RA + CD62L-) cells during active CL and post-treatment. In parallel, we investigated cell proliferation levels and the cytokines produced after stimulation. Interestingly, we observed higher frequencies (%) in CD4+ TEM during CL, and CD8+ TEM and CD8+ TCM during CL and post-treatment. Cell proliferation was increased, and a significant difference in expression was observed on T-bet and RORγT. Besides that, IFN-γ, IL-2, and IL-10 were detected in patient samples. Collectively, this dataset suggests that during CL there is an increase in the frequency of TCM and TEM, especially in the CD8 compartment. These results indicate a potentially immunogenic profile of the peptide pools, which can support the development of anti-Leishmania formulations.

RESUMEN

Yeasts from the Candida parapsilosis complex are clinically relevant due to their high virulence and pathogenicity potential, such as adherence to epithelial cells and emission of filamentous structures, as well as their low susceptibility to antifungals. D-limonene, a natural compound, emerges as a promising alternative with previously described antibacterial, antiparasitic, and antifungal activity; however, its mechanisms of action and antivirulence activity against C. parapsilosis complex species have not been elucidated. Therefore, in the present study, we aimed to evaluate the antifungal and antivirulence action, as well as the mechanism of action of D-limonene against isolates from this complex. D-limonene exhibited relevant antifungal activity against C. parapsilosis complex yeasts, as well as excellent antivirulence activity by inhibiting yeast morphogenesis and adherence to the human epithelium. Furthermore, the apoptotic mechanism induced by this compound, which is not induced by oxidative stress, represents an important target for the development of new antifungal drugs.

Asunto(s)

Antifúngicos , Candida parapsilosis , Humanos , Antifúngicos/farmacología , Virulencia , Limoneno/farmacología , Factores de Virulencia , Pruebas de Sensibilidad Microbiana , Saccharomyces cerevisiae

RESUMEN

BACKGROUND: Visceral leishmaniasis (VL) remains an important infectious disease worldwide. VL-HIV coinfected individuals can present with atypical clinical forms of VL and have a high risk of VL relapse. Some cytokines have been described as potential markers to diagnose active VL and to predict the severity of the cases. However, few studies have included VL-HIV coinfected patients. We aimed to characterize the levels of several cytokines among VL-HIV coinfected individuals living in a VL-endemic area in Northeast Brazil. METHODS: This was a retrospective, cross-sectional study, aiming to estimate the levels of various cytokines in symptomatic and asymptomatic VL-HIV coinfected individuals. There were 134 study participants (35 symptomatic VL-HIV, 75 asymptomatic VL-HIV, and 24 healthy controls), all ≥ 18 years-old. Serum cytokine levels (interferon-γ, tumor necrosis factor, and interleukins 2, 4, 6, 10, and 17A) were quantified using the Becton Dickinson-BD's Cytometric Bead Array (CBA) system. RESULTS: The population mainly consisted of men (64.9%), with a median age of 35 (27-41) years. Asymptomatic individuals were younger (p = 0.013), with more years of education (p < 0.001), and were more often on antiretroviral therapy (p < 0.001) than those in the symptomatic group. Hemoglobin levels (p < 0.001), lymphocytes (p < 0.001) and CD4 count (p < 0.001) were lower in symptomatic individuals, while HIV viral loads were higher (p < 0.001). In the symptomatic VL-HIV coinfected group, we observed increased serum levels of IL-17A, IL-6, and IL-10 compared to asymptomatic patients and the healthy controls. There were no differences in the levels of all cytokines between asymptomatic VL-HIV coinfected individuals and the healthy controls. CONCLUSIONS: Higher serum levels of IL-17A, IL-6, and IL-10 cytokines were observed in symptomatic coinfected individuals but not in asymptomatically infected individuals. More studies among HIV-positive persons are needed to better understand the role of serum cytokines for prognosis, to define cure and predict VL relapses in VL-HIV coinfected individuals.

Asunto(s)

Coinfección , Infecciones por VIH , Leishmania , Leishmaniasis Visceral , Adolescente , Adulto , Brasil/epidemiología , Estudios Transversales , Citocinas , Infecciones por VIH/epidemiología , Humanos , Interleucina-10 , Interleucina-17 , Interleucina-6 , Leishmaniasis Visceral/tratamiento farmacológico , Masculino , Estudios Retrospectivos

RESUMEN

Leishmaniasis is a neglected disease that affects millions of people around the world, mainly socially vulnerable populations and is considered a serious public health problem. Caused by several species of the flagellated protozoa of the Leishmania genus, it is transmitted to man through female sand fly bites. The disease can present the cutaneous, mucocutaneous and visceral clinical forms, varying according to the parasite species and depending on host immune response. Depending on its evolution, the disease may pose serious risks to the afflicted individual's health. In general, treatment for Leishmaniasis is with pentavalent antimonials, in use for approximately 70 years. However, the existing treatment for Leishmaniasis presents drawbacks such as high toxicity, several side effects, cases of resistance, highlighting the need for new efficient therapeutic approaches. Given all the problems that involve the current treatment of leishmaniasis, it is of paramount importance to seek and screen new molecules that have leishmanicidal activity, meet the safety criteria, while presenting low toxicity, low cost, easy administration and that cure efficiently. This review presents some considerations on the leishmaniasis situation, its treatment and the current panorama for the development of new therapies.

Asunto(s)

Leishmaniasis , Conductas Terapéuticas Homeopáticas , Enfermedades Desatendidas , Inmunidad

RESUMEN

Reactive oxygen species (ROS) cause cell damage and death. To reverse these effects, cells produce substances such as reduced glutathione (GSH) that serve as substrates for antioxidant enzymes. One way to combat microbial resistance includes nullifying the effect of glutathione in microbial cells, causing them to die from oxidative stress. The compound 2-((5-nitrothiophen-2-yl)methylene)-N-(pyridin-3-yl) hydrazine carbothioamide (L10) is a new thiophene-thiosemicarbazone derivative with promising antifungal activity. The aim of this study was to evaluate its mechanism of action against Candida albicans using assays that evaluate its effects on redox balance. Treatment with L10 promoted significant changes in the minimum inhibitory concentration (MIC) values in ascorbic acid and GSH protection tests, the latter increasing up to 64-fold of the MIC. Using nuclear magnetic resonance, we demonstrated interaction of L10 and GSH. At concentrations of 4.0 and 8.0 µg/mL, significant changes were observed in ROS production and mitochondrial membrane potential. The cell death profile showed characteristics of initial apoptosis at inhibitory concentrations (4.0 µg/mL). Transmission electron microscopy data corroborated these results and indicated signs of apoptosis, damage to plasma and nuclear membranes, and to mitochondria. Taken together, these results suggest a possible mechanism of action for L10 antifungal activity, involving changes in cellular redox balance, ROS production, and apoptosis-compatible cellular changes.

Asunto(s)

Antifúngicos/farmacología , Apoptosis/efectos de los fármacos , Candida albicans/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Tiofenos/farmacología , Tiosemicarbazonas/farmacología , Antifúngicos/química , Humanos , Estructura Molecular , Tiofenos/química , Tiosemicarbazonas/química

RESUMEN

Chagas disease, caused by the protozoan Trypanosoma cruzi, is considered a public health problem. The current chemotherapy for this illness causes serious side effects and its use in the chronic phase of the disease is still controversial. In this regard, the investigation of novel therapeutic strategies remains a priority. The essential oils (EOs) from aromatic plants emerge as a promising source of bioactive compounds. In a previous work we reported the trypanocidal activity of the essential oils from the medicinal plants Lippia sidoides (LSEO) and Lippia origanoides (LOEO) against T. cruzi. Herein, we aimed to further investigate, in more details, the mode of action of LSEO and LOEO on the different developmental stages of this parasite. We showed that Lippia sidoides (LSEO) and Lippia origanoides (LOEO) induced a significant reduction in the percentage of macrophages infected by T. cruzi and in the number of intracellular parasites. Ultrastructural analysis showed that the treatment with both oils caused morphological changes consistent with loss of viability and cell death. The reduced staining with calcein and the increase in the proportion of HE-positive cells also demonstrated that LSEO and LOEO caused loss of parasite viability and membrane integrity. A considerable decrease in Rhodamine 123 and an increase in fluorescence intensity of MitoSox in LOEO were indicative of loss of mitochondrial potential and generation of reactive oxygen species, which ultimately lead to parasite death. Moreover, the optical tweezer analysis indicated that LOEO was more effective in reducing the motility of the epimastigotes. Taken together, our results demonstrated that the LSEO and LOEO are active against T. cruzi and constitute a promising drugs for the therapy of Chagas disease.

Asunto(s)

Enfermedad de Chagas/tratamiento farmacológico , Aceites Volátiles/farmacología , Aceites de Plantas/farmacología , Tripanocidas/farmacología , Trypanosoma cruzi/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Enfermedad de Chagas/parasitología , Enfermedad de Chagas/prevención & control , Lippia/química , Trypanosoma cruzi/ultraestructura

RESUMEN

Parasitic diseases still represent serious public health problems, since the high and steady emergence of resistant strains is evident. Because parasitic infections are distributed predominantly in developing countries, less toxic, more efficient, safer and more accessible drugs have become desirable in the treatment of the infected population. This is the case of leishmaniasis, an infectious disease caused by a protozoan of the genus Leishmania sp., responsible for triggering pathological processes from the simplest to the most severe forms leading to high rates of morbidity and mortality throughout the world. In the search for new leishmanicidal drugs, the thiosemicarbazones and the indole fragments have been identified as promising structures for leishmanicidal activity. The present study proposes the synthesis and structural characterization of new indole-thiosemicarbazone derivatives (2a-j), in addition to performing in vitro evaluations through cytotoxicity assays using macrophages (J774) activity against forms of Leishmania infantum and Leishmania amazonensis promastigote as well as ultrastructural analyzes in promastigotes of L. infantum. Results show that the indole-thiosemicarbazone derivatives were obtained with yield values varying from 32.09 to 94.64%. In the evaluation of cytotoxicity, the indole-thiosemicarbazone compounds presented CC50 values between 53.23 and 357.97 µM. Concerning the evaluation against L. amazonensis promastigote forms, IC50 values ranged between 12.31 and  > 481.52 µM, while the activity against L. infantum promastigotes obtained IC50 values between 4.36 and 23.35 µM. The compounds 2d and 2i tested against L. infantum were the most promising in the series, as they showed the lowest IC50 values: 5.60 and 4.36 respectively. The parasites treated with the compounds 2d and 2i showed several structural alterations, such as shrinkage of the cell body, shortening and loss of the flagellum, intense mitochondrial swelling and vacuolization of the cytoplasm leading the parasite to cellular unviability. Therefore, the indole-thiosemicarbazone compounds are promising because they yield considerable synthesis, have low cytotoxicity to mammalian cells and act as leishmanicidal agents.

Asunto(s)

Antiprotozoarios/farmacología , Indoles/farmacología , Leishmania infantum/efectos de los fármacos , Leishmaniasis/tratamiento farmacológico , Tiosemicarbazonas/farmacología , Animales , Línea Celular , Supervivencia Celular/efectos de los fármacos , Leishmaniasis/parasitología , Macrófagos/efectos de los fármacos , Mitocondrias/efectos de los fármacos

RESUMEN

BACKGROUND: The present study aimed to demonstrate the applicability of a flow cytometry-based serology approach to identify spontaneous cure by the detection of immunoglobulin G, and also, the diagnosis and cure criterion by the IgG1 isotype in American Tegumentary Leishmaniasis - ATL caused by L. (V.) braziliensis. Also, a comparison between flow cytometry with the serological conventional technique was performed. METHODS: Forty five individuals were included in study. They were assessed in two moments: First, 8 subjects spontaneously cured of ATL, 8 healthy individuals and 15 patients who had a positive diagnosis for ATL were selected before treatment to identify spontaneous cure by immunoglobulin G detection. Secondly, 14 patients who were positive for ATL were selected and had their blood collected before and 1, 2 and 5 years after treatment, respectively, for the diagnostic tests (ELISA and flow cytometry) and cure criterion evaluation using the IgG1 isotype. RESULTS: The analysis of the mean percentage of positive fluorescent parasites (PPFP) along with the titration curves of IgG anti-fixed promastigotes of L.(V.)braziliensis, confirmed the applicability of this method for monitoring spontaneous cure in ATL with outstanding co-positivity (100%) and co-negativity (100%) performance indexes. Regarding the results of the comparison between flow cytometry and ELISA it was seen that there was a better accuracy of the first one in relation to the other. When IgG1 applicability was evaluated, it was observed that before treatment, 36.8% of the patients were negative; in patients 1 year post-treatment, 82.3%; 2 years post-treatment, 27.2% and in patients 5 years post-treatment, 87.5%. The overall analysis of the results suggests that flow cytometry can be applied to ATL detection, and that the use of IgG1 isotype has possibilities to contribute as a more specific diagnostic method. CONCLUSIONS: Therefore, this area has great perspectives use for the diagnosis and cure criterion, and also it can be scaled up with the possibility to characterize the different clinical stages of the disease. Together, these findings demonstrate the applicability of a flow cytometry-based serology approach and opens up new avenues of research with this technique, such as the understanding the humoral response in ATL patients.

Asunto(s)

Leishmania braziliensis/inmunología , Leishmaniasis Cutánea/diagnóstico , Anticuerpos Antiprotozoarios/sangre , Antiprotozoarios/uso terapéutico , Área Bajo la Curva , Ensayo de Inmunoadsorción Enzimática , Citometría de Flujo , Humanos , Inmunoglobulina G/sangre , Leishmania braziliensis/aislamiento & purificación , Leishmaniasis Cutánea/tratamiento farmacológico , Curva ROC , Remisión Espontánea

RESUMEN

Twelve 2-(quinolin-4-ylmethylene) hydrazinecarbothioamide derivatives were synthetized and their biological properties were investigated, among which, the ability to interact with DNA and BSA through UV-Vis absorption, fluorescence, Circular Dichroism, molecular docking and relative viscosity, antiproliferative activity against MCF-7 and T-47D mammary tumor cells and RAW-264.7 macrophages and inhibitory capacity of the enzyme topoisomerase IIα. In the binding study with DNA and BSA, all the compounds displayed affinity for interaction with both biomolecules, especially JF-92 (p-ethyl-substituted), with binding constant of 1.62 × 106 and 1.43 × 105, respectively, and DNA binding mode by intercalation. The IC50 values were obtained between 0.81 and 1.48 µM and topoisomerase inhibition results in 10 µM. Thus, we conclude that the reduction of the acridine to quinoline ring did not disrupt the antitumor action and that substitution patterns are important for biomolecule interaction affinity as they demonstrate the potential of these compounds for anticancer therapy.

Asunto(s)

Antineoplásicos/farmacología , ADN-Topoisomerasas de Tipo II/metabolismo , Quinolinas/farmacología , Tiosemicarbazonas/farmacología , Inhibidores de Topoisomerasa II/farmacología , Animales , Antineoplásicos/síntesis química , Antineoplásicos/química , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Células MCF-7 , Sustancias Macromoleculares/síntesis química , Sustancias Macromoleculares/química , Sustancias Macromoleculares/farmacología , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Ratones , Modelos Moleculares , Estructura Molecular , Quinolinas/síntesis química , Quinolinas/química , Células RAW 264.7 , Relación Estructura-Actividad , Tiosemicarbazonas/síntesis química , Tiosemicarbazonas/química , Inhibidores de Topoisomerasa II/síntesis química , Inhibidores de Topoisomerasa II/química , Viscosidad

RESUMEN

Liver diseases are a major health problem worldwide leading to high mortality rates and causing a considerable economic burden in many countries. Cellular therapies as potential treatments for liver diseases have proven beneficial in most of the conditions. In recent years, studies involving therapy with bone marrow cells have been implemented to promote liver regeneration and to reduce hepatic fibrosis, however identifying the cell population present in the bone marrow that is responsible for hepatic improvement after therapy is still necessary. The aim of the present study was the evaluation of the therapeutic efficacy of monocytes obtained from bone marrow in fibrosis resulting from S. mansoni infection in C57BL/6 mice. Monocytes were isolated by immunomagnetic separation and administered to the infected animals. The effects of treatment were evaluated through morphometric, biochemical, immunological and molecular analyzes. Monocyte therapy promoted reduction of liver fibrosis induced by S. mansoni infection, associated with a decrease in production of inflammatory and pro-fibrogenic mediators. In addition, monocyte infusion caused downregulation of factors associated with the M1 activation profile, as well as upregulation of M2reg markers. The findings altogether reinforce the hypothesis that the predominance of M2reg macrophages, producers of immunosuppressive cytokines, may favor the improvement of hepatic fibrosis in a preclinical model, through fibrous tissue remodeling, modulation of the inflammatory response and fibrogenesis.

Asunto(s)

Traslado Adoptivo/métodos , Tratamiento Basado en Trasplante de Células y Tejidos/métodos , Cirrosis Hepática/terapia , Regeneración Hepática , Monocitos/trasplante , Schistosoma mansoni/patogenicidad , Esquistosomiasis mansoni/terapia , Animales , Células de la Médula Ósea/citología , Células de la Médula Ósea/inmunología , Diferenciación Celular , Citocinas/genética , Citocinas/inmunología , Modelos Animales de Enfermedad , Regulación de la Expresión Génica , Hígado/inmunología , Hígado/parasitología , Hígado/patología , Cirrosis Hepática/inmunología , Cirrosis Hepática/parasitología , Cirrosis Hepática/patología , Macrófagos/citología , Macrófagos/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Monocitos/citología , Monocitos/inmunología , Schistosoma mansoni/crecimiento & desarrollo , Esquistosomiasis mansoni/inmunología , Esquistosomiasis mansoni/parasitología , Esquistosomiasis mansoni/patología

RESUMEN

AIM: To evaluate the therapeutic effects of bone marrow-derived CD11b+CD14+ monocytes in a murine model of chronic liver damage. METHODS: Chronic liver damage was induced in C57BL/6 mice by administration of carbon tetrachloride and ethanol for 6 mo. Bone marrow-derived monocytes isolated by immunomagnetic separation were used for therapy. The cell transplantation effects were evaluated by morphometry, biochemical assessment, immunohistochemistry and enzyme-linked immunosorbent assay. RESULTS: CD11b+CD14+ monocyte therapy significantly reduced liver fibrosis and increased hepatic glutathione levels. Levels of pro-inflammatory cytokines, including tumor necrosis factor-α, interleukin (IL)-6 and IL-1ß, in addition to pro-fibrotic factors, such as IL-13, transforming growth factor-ß1 and tissue inhibitor of metalloproteinase-1 also decreased, while IL-10 and matrix metalloproteinase-9 increased in the monocyte-treated group. CD11b+CD14+ monocyte transplantation caused significant changes in the hepatic expression of α-smooth muscle actin and osteopontin. CONCLUSION: Monocyte therapy is capable of bringing about improvement of liver fibrosis by reducing oxidative stress and inflammation, as well as increasing anti-fibrogenic factors.

Asunto(s)

Tratamiento Basado en Trasplante de Células y Tejidos/métodos , Citocinas/metabolismo , Cirrosis Hepática/terapia , Hígado/metabolismo , Monocitos/trasplante , Actinas/metabolismo , Animales , Antígeno CD11b/metabolismo , Tetracloruro de Carbono/toxicidad , Separación Celular , Modelos Animales de Enfermedad , Ensayo de Inmunoadsorción Enzimática , Etanol/toxicidad , Citometría de Flujo , Glutatión/metabolismo , Humanos , Inmunohistoquímica , Receptores de Lipopolisacáridos/metabolismo , Hígado/patología , Cirrosis Hepática/inducido químicamente , Cirrosis Hepática/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Monocitos/metabolismo , Osteopontina/metabolismo , Estrés Oxidativo

RESUMEN

Chagas disease is a parasitic infection caused by protozoan Trypanosoma cruzi that affects approximately 6-7 million people worldwide. Benznidazole is the only drug approved for treatment during the acute and asymptomatic chronic phases; however, its efficacy during the symptomatic chronic phase is controversial. The present work reports the synthesis and anti-T. cruzi activities of a novel series of phthalimido-thiazoles. Some of these compounds showed potent inhibition of the trypomastigote form of the parasite at low cytotoxicity concentrations in spleen cells, and the resulting structure-activity relationships are discussed. We also showed that phthalimido-thiazoles induced ultrastructural alterations on morphology, flagellum shortening, chromatin condensation, mitochondria swelling, reservosomes alterations and endoplasmic reticulum dilation. Together, these data revealed, for the first time, a novel series of phthalimido-thiazoles-structure-based compounds with potential effects against T. cruzi and lead-like characteristics against Chagas disease.

Asunto(s)

Ftalimidas/farmacología , Tiazoles/farmacología , Tripanocidas/farmacología , Trypanosoma cruzi/efectos de los fármacos , Trypanosoma cruzi/crecimiento & desarrollo , Animales , Proliferación Celular/efectos de los fármacos , Chlorocebus aethiops , Ratones , Ratones Endogámicos BALB C , Pruebas de Sensibilidad Parasitaria , Ftalimidas/química , Bazo/citología , Bazo/efectos de los fármacos , Tiazoles/química , Tripanocidas/síntesis química , Tripanocidas/química , Células Vero

RESUMEN

OBJECTIVE: Evaluate the effects of neonatal malnutrition on the microbicidal response and viability of in vitro macrophages infected with Staphylococcus aureus sensitive/resistant to methicillin. METHODS: Male Wistar rats (n = 24) were divided into two distinct groups: nourished (rats breast-fed by mothers undergoing diet with 17% casein) and malnourished (rats breast-fed by mothers undergoing diet with 8% casein). Macrophages were recovered after surgical tracheostomy procedure by collecting bronchoalveolar lavage. Four systems were established: negative control, composed only by phagocytes; positive control, macrophages plus lipopolysaccharide; and two test systems, macrophages plus Staphylococcus aureus sensitive and resistant to methicillin. Plates were incubated at 37 °C for 24 h. After this period, tests for the analysis of cell viability and microbicidal response were performed. In the statistical analysis, the Student's t and ANOVA tests were used, accepting p < 0.05. RESULTS: The neonatal malnutrition impaired the animals' body weight. There was a lower expression of the inducible nitric oxide enzyme (iNOS), nitric oxide production, and viability of macrophages infected with methicillin-resistant Staphylococcus aureus. However, increased production of superoxide anion in the malnourished group was detected. CONCLUSION: Neonatal malnutrition focusing on critical periods of development promoted lower expression of iNOS, nitric oxide production, cell viability, and exacerbated reactive oxygen species production. The high levels of reactive oxygen species may favor the onset of serious and systemic infections with fatal outcome if associated with methicillin-resistant Staphylococcus aureus.

Asunto(s)

Radicales Libres/metabolismo , Macrófagos Alveolares/microbiología , Desnutrición/microbiología , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Óxido Nítrico Sintasa de Tipo II/metabolismo , Staphylococcus aureus/aislamiento & purificación , Animales , Animales Recién Nacidos , Peso Corporal , Supervivencia Celular , Dieta , Lipopolisacáridos/efectos adversos , Macrófagos Alveolares/citología , Masculino , Desnutrición/fisiopatología , Meticilina/farmacología , Viabilidad Microbiana/efectos de los fármacos , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo II/genética , Fagocitos/metabolismo , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo , Superóxidos/metabolismo

RESUMEN

The discovery of new antiparasitic compounds against Trypanosoma cruzi, the etiological agent of Chagas disease, is necessary. Novel aryloxy/aryl thiosemicarbazone-based conformationally constrained analogs of thiosemicarbazones (1) and (2) were developed as potential inhibitors of the T. cruzi protease cruzain, using a rigidification strategy of the iminic bond of (1) and (2). A structure-activity relationship analysis was performed in substituents attached in both aryl and aryloxy rings. This study indicated that apolar substituents or halogen atom substitution at the aryl position improved cruzain inhibition and antiparasitic activity in comparison to unsubstituted thiosemicarbazone. Two of these compounds displayed potent inhibitory antiparasitic activity by inhibiting cruzain and consequently were able to reduce the parasite burden in infected cells and cause parasite cell death through necrosis. In conclusion, we demonstrated that conformational restriction is a valuable strategy in the development of antiparasitic thiosemicarbazones.

Asunto(s)

Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Proteínas Protozoarias/antagonistas & inhibidores , Tiosemicarbazonas/farmacología , Tripanocidas/química , Tripanocidas/farmacología , Trypanosoma cruzi/efectos de los fármacos , Cristalografía por Rayos X , Cisteína Endopeptidasas/metabolismo , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/química , Modelos Moleculares , Estructura Molecular , Pruebas de Sensibilidad Parasitaria , Proteínas Protozoarias/metabolismo , Relación Estructura-Actividad , Tiosemicarbazonas/síntesis química , Tiosemicarbazonas/química , Tripanocidas/síntesis química , Trypanosoma cruzi/enzimología

RESUMEN

The aim of this study was to compare the techniques of indirect immunofluorescence assay (IFA) and flow cytometry to clinical and laboratorial evaluation of patients before and after clinical cure and to evaluate the applicability of flow cytometry in post-therapeutic monitoring of patients with American tegumentary leishmaniasis (ATL). Sera from 14 patients before treatment (BT), 13 patients 1 year after treatment (AT), 10 patients 2 and 5 years AT were evaluated. The results from flow cytometry were expressed as levels of IgG reactivity, based on the percentage of positive fluorescent parasites (PPFP). The 1:256 sample dilution allowed us to differentiate individuals BT and AT. Comparative analysis of IFA and flow cytometry by ROC (receiver operating characteristic curve) showed, respectively, AUC (area under curve)=0.8 (95% CI=0.64-0.89) and AUC=0.90 (95% CI=0.75-0.95), demonstrating that the flow cytometry had equivalent accuracy. Our data demonstrated that 20% was the best cut-off point identified by the ROC curve for the flow cytometry assay. This test showed a sensitivity of 86% and specificity of 77% while the IFA had a sensitivity of 78% and specificity of 85%. The after-treatment screening, through comparative analysis of the technique performance indexes, 1, 2 and 5 years AT, showed an equal performance of the flow cytometry compared with the IFA. However, flow cytometry shows to be a better diagnostic alternative when applied to the study of ATL in the cure criterion. The information obtained in this work opens perspectives to monitor cure after treatment of ATL.

Asunto(s)

Citometría de Flujo/métodos , Técnica del Anticuerpo Fluorescente Indirecta/métodos , Inmunoglobulina G/inmunología , Leishmania braziliensis/inmunología , Leishmaniasis Cutánea/inmunología , Adolescente , Adulto , Anciano , Anticuerpos Antiprotozoarios/sangre , Anticuerpos Antiprotozoarios/inmunología , Femenino , Humanos , Inmunoglobulina G/uso terapéutico , Leishmaniasis Cutánea/sangre , Leishmaniasis Cutánea/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Evaluación de Resultado en la Atención de Salud/métodos , Reproducibilidad de los Resultados , Factores de Tiempo , Adulto Joven

Asunto(s)

Humanos , Citometría de Flujo , Leishmania braziliensis , Leishmaniasis Cutánea , Brasil

RESUMEN

Cramoll 1,4 is a lectin extracted from Cratylia mollis Mart. seeds that has shown antitumor and lymphocyte mitogenic activities in other studies. The aim of this work was to investigate, in vitro, the immunomodulatory activity of Cramoll 1,4 on experimental cultures of mice lymphocytes through cytotoxic assays, nitric oxide (NO) concentrations and IL-10 and IFN-γ production. Cramoll 1,4 did not show cytotoxic activity at 1-25 µg/mL concentrations, similar results were observed with concanavalin A (Con A) and phytohemagglutinin (PHA) lectins. The minimum production of IL-10 was observed in splenocytes cultivated with Con A, PHA and Cramoll 1,4 lectins. However, splenocytes treated with Cramoll 1,4 showed higher IFN-γ production in comparison with PHA and Con A (p < 0.05 for both). Production of NO was effectively suppressed in murine cells stimulated with the lectins and was only detected after 72 h for PHA in relation to non-stimulated lymphocytes (p < 0.05). Cramoll 1,4 was not toxic to murine lymphocytes, induced Th1 response through IFN-γ production and showed antiinflammatory activity through NO suppression. Therefore, Cramoll 1,4 can be considered a lectin with immunomodulatory activity.

Asunto(s)

Fabaceae/química , Lectinas/farmacología , Linfocitos/efectos de los fármacos , Animales , Células Cultivadas , Concanavalina A/farmacología , Inmunomodulación , Interferón gamma/inmunología , Interleucina-10/inmunología , Linfocitos/inmunología , Masculino , Ratones , Ratones Endogámicos BALB C , Óxido Nítrico/metabolismo , Fitohemaglutininas/farmacología , Semillas/química , Bazo/citología

RESUMEN

Although effective against epimastigotes (proliferative form) and of low cytotoxicity in mammals, the aryl-4-oxothiazolylhydrazones (ATZ) display only limited activity against trypomastigotes (bloodstream form) of Trypanosoma cruzi. Considering the metal complexation approach with bioactive ligands as one possible strategy for improving the biological efficacy of ATZ, a set of eight new ruthenium-ATZ complexes (RuCl(2)ATZCOD, COD is 1,5-cyclooctadiene) were prepared, chemically and biologically characterized, including in vitro assays against epimastigotes and trypomastigote forms of the parasite and also assessment of cytotoxicity in mammals. Two of these complexes presented antitrypanosomal activity at non-cytotoxic concentrations on mammalian cells and of higher potency than its metal-free ligands, while the metallic precursor [RuCl(2)COD(MeCN)(2)] showed only moderate antitrypanosomal activity. Comparative analysis between the ruthenium complexes and metal-free ligands demonstrated the usefulness of this approach, with the establishment of new SAR data. Additional pharmacological tests, including a DNA bond assay, gave rise to the proposal of a single preliminary explanation for the molecular origin of the bioactivity.

Asunto(s)

Compuestos de Rutenio/química , Compuestos de Rutenio/farmacología , Tripanocidas/química , Tripanocidas/farmacología , Trypanosoma cruzi/efectos de los fármacos , Animales , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , ADN/metabolismo , Hidrazonas/síntesis química , Hidrazonas/química , Hidrazonas/farmacología , Ratones , Ratones Endogámicos BALB C , Plásmidos/metabolismo , Compuestos de Rutenio/síntesis química , Compuestos de Rutenio/toxicidad , Bazo/citología , Relación Estructura-Actividad , Tiazoles/síntesis química , Tiazoles/química , Tiazoles/farmacología , Tripanocidas/síntesis química , Tripanocidas/toxicidad , Trypanosoma cruzi/crecimiento & desarrollo