Synthesis and Phytotoxic Evaluation of Isatin Derivatives Supported by 3D-QSAR Study.

Concerned about weed infestation, a major threat to food production and herbicide resistance that interferes in the mechanism of action of the main herbicides, we have synthesized eight isatin derivatives using the "Click Chemistry" approach through copper-catalyzed azide-alkyne cycloadditions (CuAAC). Sixteen isatin derivatives were evaluated for their phytotoxic activity against the seed culture of the model plants, Lactuca sativa and Allium cepa. Six of them showed phytotoxic activity similar to the positive control, trifluralin. Hypocotyl length measurement analysis in L. sativa revealed that triazole derivative 8 is more active than trifluralin. For A. cepa, root length measurement analyses revealed that 3, 10, 14, 16, and 17 were similar to the positive control trifluralin. Three-dimensional quantitative structure-activity relationship (3D-QSAR) comparative molecular field analysis (CoMFA) model construction using the acetolactate synthase (ALS) crystallographic structure displayed pki values of predicted inhibitory activity and contour maps revealing sterically bulky groups for 11, the CF3 group in ortho, and for 17, Br in ortho, favoring the inhibitory ALS activity.

Virtual screening and in vitro assays of novel hits as promising DPP-4 inhibitors.

Diabetes is a metabolic disorder that presents hyperglycemia and vascular complications due to the non-production of insulin or its inappropriate use by the body. One of the strategies to treat diabetes is the inhibition of dipeptidyl peptidase-4 (DPP-4) and it is interesting to conduct virtual screening studies to search for new inhibitors of the DPP-4 enzyme. This study involves a virtual screening using the crystallographic structure of DPP-4 and a compound subset from the ZINC database. To filter this compound subset, we used some physicochemical properties, positioning at the three DPP-4 binding sites, molecular interactions, and ADME-Tox properties. The conformations of ligands obtained from AutoDock Vina were analyzed using a consensus with other algorithms (AutoDock and GOLD). The compounds selected from virtual screening were submitted to biological assays using the "DPPIV-Glo™ protease assay". Cytotoxicity tests were also performed. One promising compound (ZINC1572309) established interactions with important residues at the binding site. The results of the ADME-Tox prediction for ZINC1572309 were compared with a reference drug (sitagliptin). The cytotoxicity of sitagliptin and ZINC1572309 were evaluated using the XTT short-term cytotoxic assay, including normal and tumor cell lines to observe the cellular response to inhibitor treatment at different genetic bases. Both compounds (ZINC1572309 and the reference drug - sitagliptin) also inhibited DPP-4 activity, suggesting interesting biological effects of the selected compound at non-cytotoxic concentrations. Therefore, from in silico and in vitro studies, a potential hit as DPP-4 inhibitor was discovered and it can be structurally optimized to achieve suitable activity and pharmacokinetic profiles.

Topomer-CoMFA proposed as a tool to construct dual EGFR/HER-2 models.

Protein kinases (in this case, HER-2 and EGFR) are involved in cancer-related diseases. Some reports have shown unique CoMFA models using the sum of activities expressed as pIC50 (-log IC50), as the classical CoMFA technique would not be the best strategy to construct models for multitarget therapy considering that the molecular alignment will not be the same for different targets. An alternative for this problem is the use of Topomer-CoMFA, a variation of CoMFA, which does not require the alignment step in the generation of 3D models. In this study, we propose the combined use of the sum of activities and Topomer-CoMFA for the construction of a unique dual 3D model considering the inhibitory activities against EGFR and HER-2. For this, 88 compounds from the literature were divided into two groups: training (71) and test (17) sets. The biological activity of each compound, expressed as IC50 for EGFR and HER-2, was transformed into pIC50, summed, and used as the dependent variable in the Topomer-CoMFA analyses. The obtained model was considered statistically robust in the prediction of the dual activity of new compounds. Finally, based on the obtained model, we proposed structural modifications to some of the compounds used to improve the biological data. From the 3D model, we suggested new derivative compounds with improved biological activity for both targets. Therefore, the combination of the techniques proposed in this study proves to be a good strategy to construct better statistical models that can predict biological activities in multitarget systems.

Flavonoid Derivatives Targeting BCR-ABL Kinase: Semisynthesis, Molecular Dynamic Simulations and Enzymatic Inhibition.

BACKGROUND: Natural products have been universally approached in the research of novel trends useful to detail the essential paths of the life sciences and as a strategy for pharmacotherapeutics. OBJECTIVE: This work focuses on further modification to the 6-hydroxy-flavanone building block aiming to obtain improved BCR-ABL kinase inhibitors. METHODS: Ether derivatives were obtained from Williamson synthesis and triazole from Microwave- assisted click reaction. Chemical structures were finely characterized through IR, 1H and 13C NMR and HRMS. They were tested for their inhibitory activity against BCR-ABL kinase. RESULTS: Two inhibitors bearing a triazole ring as a pharmacophoric bridge demonstrated the strongest kinase inhibition at IC50 value of 364 nM (compound 3j) and 275 nM (compound 3k). CONCLUSION: 6-hydroxy-flavanone skeleton can be considered as a promising core for BCR-ABL kinase inhibitors.

Factors Associated with Depressive Symptoms Among Rural Residents from Remote Areas.

This study aimed to investigate the risk factors for depressive symptoms among rural residents in Brazil. A representative sample of two hundred eighty-eight volunteers aged from 18 to 65 years was included and determining factors for high BDI-II score were investigated through a multivariate logistic model. Sadness, loss of pleasure, crying, worthlessness and loss of interest in sex are more likely to be observed in females, and risk factors to this high depression score among rural residents were shown to be: female gender, tobacco use, pesticide application, poor self-perceived health and presence of chronic disease. These data contribute to the knowledge of factors determining depressive symptoms among rural residents and may help to expand health policies to improve quality of rural life on these communities and others with similar characteristics.

Correction to: The role of fat on cardiomyopathy outcome in mouse models of chronic Trypanosoma cruzi infection.

The authors regret that Philipp E Scherer's name was spelt incorrectly in the author list. The name of the author is now corrected above.

The role of fat on cardiomyopathy outcome in mouse models of chronic Trypanosoma cruzi infection.

The underlying pathogenic mechanisms of cardiomyopathy in Chagas disease are still unsolved. In order to better clarify the role of fat on the evolution of cardiomyopathy, the present study employed three murine models of chronic Trypanosoma cruzi infection: (1) aP2-RIDα/ß transgenic mice (RID mice; an adipose tissue model which express a gain-of-function potent anti-inflammatory activity), (2) allograft inflammatory factor-1 knockout mice (Aif1-/-), and (3) a Swiss outbred mice. RID mice and non-transgenic mice (wild type, WT) were infected with blood trypomastigotes of Brazil strain. During the acute stage of infection, RID mice had lower parasitemia, lower heart inflammation, and a decrease in the relative distribution of parasite load from cardiac muscle tissue toward epididymal fat. Nevertheless, comparable profiles of myocardial inflammatory infiltrates and relative distribution of parasite load were observed among RID and WT at the chronic stage of infection. Aif1-/- and Aif1+/+ mice were infected with bloodstream trypomastigotes of Tulahuen strain and fed with high-fat diet (HFD) or regular diet (RD). Interestingly, Aif1+/+ HFD infected mice showed the highest mortality. Swiss mice infected with blood trypomastigotes of Berenice-78 strain on a HFD had higher levels of TNFα and more inflammation in their heart tissue than infected mice fed a RD. These various murine models implicate adipocytes in the pathogenesis of chronic Chagas disease and suggest that HFD can lead to a significant increase in the severity of parasite-induced chronic cardiac damage. Furthermore, these data implicate adipocyte TLR4-, TNFα-, and IL-1ß-mediated signaling in pro-inflammatory pathways and Aif-1 gene expression in the development of chronic Chagas disease.

Synthesis of Coumarin Derivatives as Versatile Scaffolds for GSK-3ß Enzyme Inhibition.

BACKGROUND: Glycogen synthase kinase-3 (GSK-3) is involved in the phosphorylation and inactivation of glycogen synthase. GSK-3 inhibitors have been associated with a variety of diseases, including Alzheimer´s disease (AD), diabetes type II, neurologic disorders, and cancer. The inhibition of GSK-3ß isoforms is likely to represent an effective strategy against AD. OBJECTIVE: The present work aimed to design and synthesize coumarin derivatives to explore their potential as GSK-3ß kinase inhibitors. METHODS: The through different synthetic methods were used to prepare coumarin derivatives. The GSK-3ß activity was measured through the ADP-Glo™ Kinase Assay, which quantifies the kinasedependent enzymatic production of ADP from ATP, using a coupled-luminescence-based reaction. A docking study was performed by using the crystallographic structure of the staurosporine/GSK-3ß complex [Protein Data Bank (PDB) code: 1Q3D]. RESULTS: The eleven coumarin derivatives were obtained and evaluated as potential GSK-3ß inhibitors. Additionally, in silico studies were performed. The results revealed that the compounds 5c, 5d, and 6b inhibited GSK-3ß enzymatic activity by 38.97-49.62% at 1 mM. The other coumarin derivatives were tested at 1 mM, 1 µM, and 1 nM concentrations and were shown to be inhibitor candidates, with significant IC50 (1.224-6.875 µM) values, except for compound 7c (IC50 = 10.809 µM). Docking simulations showed polar interactions between compound 5b and Lys85 and Ser203, clarifying the mechanism of the most potent activity. CONCLUSION: The coumarin derivatives 3a and 5b, developed in this study, showed remarkable activity as GSK-3ß inhibitors.

Studies on the Dual Activity of EGFR and HER-2 Inhibitors Using Structure-Based Drug Design Techniques.

HER-2 and EGFR are biological targets related to the development of cancer and the discovery and/or development of a dual inhibitor could be a good strategy to design an effective drug candidate. In this study, analyses of the chemical properties of a group of substances having affinity for both HER-2 and EGFR were carried out with the aim of understanding the main factors involved in the interaction between these inhibitors and the biological targets. Comparative analysis of molecular interaction fields (CoMFA) and comparative molecular similarity index analysis (CoMSIA) techniques were applied on 63 compounds. From CoMFA analyses, we found for both HER-2 (r² calibration = 0.98 and q²cv = 0.83) and EGFR (r² calibration = 0.98 and q²cv = 0.73) good predictive models. Good models for CoMSIA technique have also been found for HER-2 (r² calibration = 0.92 and q²cv = 0.74) and EGFR (r² calibration = 0.97 and q²cv = 0.72). The constructed models could indicate some important characteristics for the inhibition of the biological targets. New compounds were proposed as candidates to inhibit both proteins. Therefore, this study may guide future projects for the development of new drug candidates for the treatment of breast cancer.

Psychosocial stress and central adiposity: A Brazilian study with a representative sample of the public health system users.

OBJECTIVE: To assess the association between indicators of psychosocial stress and central adiposity in adult users of the Unified Health System (SUS) from Southeast of Brazil. METHODS: This cross-sectional study was conducted with 384 adults (20 to 59 years old) from the city of Alegre, Southeastern Brazil. The simple random sample represented the population using the public health system of the municipality. The prevalence of obesity was based on the Body Mass Index, and central adiposity (dependent variable) was measured by waist circumference in centimeters. The independent variables were the following indicators of psychosocial stress: food and nutrition insecurity (yes/no), serum cortisol (µg/dL), symptoms suggestive of depression using the Beck Depression Inventory-II ≥ 17 (yes/no), and altered blood pressure ≥ 130/85 mmHg (yes/no). Univariate linear regression was performed between central adiposity and each stress indicator, and later the models were adjusted for socioeconomic, health, and lifestyle variables. All analyses were made separately by rural and urban location. RESULTS: The prevalence of weight excess, by the classification of the Body Mass Index ≥ 25.0 kg/m2, was 68.3% and, by waist circumference, 71.5% of individuals presented an increased risk for metabolic complications related to central adiposity. Mean waist circumference scores for the rural and urban population were 89.3 ± 12.7 cm and 92.9 ± 14.7 cm, respectively (p = 0.012). Indicators of stress that were associated with central adiposity were: cortisol in the rural population (ß = -0.60; 95% CI = -1.09;-0.11) and altered blood pressure in the urban population (ß = 6.66; 95% CI = 2.14;11.18). This occurred both in the raw analysis and in the models adjusted for confounding factors. CONCLUSION: Central adiposity was inversely associated with cortisol in the rural population and directly associated with higher arterial blood pressure in the urban population, suggesting a local influence on how individuals react to stress.

Effects of brown and golden flaxseed on the lipid profile, glycemia, inflammatory biomarkers, blood pressure and body composition in overweight adolescents.

BACKGROUND: Flaxseed is a promising alternative to reduce the risk of diseases associated with body weight excess because it is rich in a-linolenic acid, lignans, and dietary fiber. Flaxseed (Linum usitatissimum) can be found in brown and golden varieties; however, questions have arisen as to whether the variety may influence the health effects. OBJECTIVE: The objective of this study was to compare the effects of brown and golden flaxseeds on lipid profile, glycemia, blood pressure, inflammatory status,body weight, and body composition in overweight adolescents. METHODS: Seventy-five overweight adolescents (33 boys, 42 girls; age 13.7 ! 2.1 y), from Alegre-ES, Brazil, were randomized to one of the three groups (n » 25) on a parallel, single-blind clinical trial. They received 28 g/d of brown flaxseed (BF), golden flaxseed (GF), or the equivalent amount of wheat bran (Control, CG) in different preparations at school from Monday to Friday for 11 wk. Blood pressure, anthropometric evaluation, and the analyses of blood total cholesterol, lipoproteins, glucose, and inflammatory markers were performed at the beginning and at the end of the intervention. The data were analyzed by ANCOVA at 5% significance. RESULTS: The groups who consumed brown and golden flaxseed showed significant reduction in diastolic blood pressure. Brown and golden flaxseed did not differentially affect plasma lipid responses, plasma glucose and inflammatory profile, although all groups (BF, GF, and CG) showed increased levels of TNF-a. CONCLUSIONS: The adolescents consumed about half the daily amount provided, which may not have been sufficient to exert the health benefits of flaxseed reported in the literature, concerning the lipid profile, inflammation biomarkers and body composition.

Metabolic syndrome components can predict C reactive protein concentration in adolescents.

BACKGROUND: Metabolic syndrome (MS) is suggested to be associated with a low grade inflammation state, but the relationship between inflammation biomarkers and the components of metabolic syndrome in adolescents are still lacking. OBJECTIVE: To investigate the association between C-reactive protein (CRP) serum concentrations and metabolic syndrome components in adolescents. METHODS: A cross-sectional population based study was conducted. Anthropometric, biochemical and clinical data were collected from 524 adolescents (11-15 years old) randomly sampled from school population of Alegre city, Espírito Santo, Brazil. Data were analyzed by STATA version 9.0. RESULTS: Adolescents with higher values for BMI (p = 0.001) and higher body fat percentage (p = 0.003) had higher CRP concentrations than those with lower BMI and body fat percentage. CRP concentrations was directly correlated with BMI (r = 0.17, p = 0.0001), waist circumference (r = 0.15, p = 0.0005), HDL-c (r = 0.13, p = 0.003), fasting insulin (r = 0.12, p = 0.003) and systolic blood pressure (r = 0.11, p with = 0.01). In the multiple linear regression analysis BMI (r = 0.05, p = 0.002), fasting glucose (r = -0.01, p = 0.003) and HDL-c (r = 0.017, p < 0.001) were associated to CRP concentrations after adjusting for the other components of MS. CONCLUSION: The association found between individual components of MS and CRP concentrations suggests that inflammation might be an early event in the development of metabolic disorders in adolescents.

Antecedentes: El síndrome metabólico (SM) se sugiere que está asociada con un estado de inflamación crónica de bajo grado, pero la relación entre biomarcadores de inflamación crónica de bajo grado, pero la relación entre biomarcadores de inflamación y los componentes del síndrome metabólico en adolescentes son escasos. Objetivo: Investigar la asociación entre las concentraciones séricas de proteína C reactiva (CRP) y los componentes del síndrome metabólico en adolescentes. Metodología: Hemos realizado una población basada en estudio de corte transversal. Los datos antropométricos, bioquímicos y clínicos se obtuvieron de 524 adolescentes (11-15 años de edad) seleccionados al azar de la población escolar de la ciudad Alegre, Espírito Santo, Brasil. Los datos fueron analizados por STATA versión 9.0. Resultados: Los adolescentes, con valores más altos de IMC (p = 0,001) y mayor porcentaje de grasa corporal (p = 0,003) tuvieron mayores concentraciones de PCR que aquellos con menor IMC y porcentaje de grasa corporal. Las concentraciones de PCR se correlacionó directamente con el IMC (r = 0,17, p = 0,0001), la circunferencia de la cintura (r = 0,15, p = 0,0005), HDL-c (r = 0,13, p = 0,003), la insulina en ayunas (r = 0,12, p = 0,009) y la presión arterial sistólica (r = 0,11, p = a 0,01). En el análisis de regresión lineal múltiple IMC (r = 0,05, p = 0,002), la glucosa en ayunas (r = -0,01, p = 0,003) y HDL-c (r = 0,017, p < 0,001) se asociaron a las concentraciones de PCR después de ajustar por los otros componentes de SM. Conclusión: La asociación encontrada entre los componentes individuales de SM y las concentraciones de PCR sugiere que la inflamación podría ser un evento temprano en el desarrollo de trastornos metabólicos en los adolescentes.

Iron overload alters glucose homeostasis, causes liver steatosis, and increases serum triacylglycerols in rats.

The objective of this study was to investigate the effect of iron overload with a hyperlipidemic diet on the histologic feature of hepatic tissue, the lipid and glycemic serum profiles, and the markers of oxidative damage and stress in a rat model. Twenty-four male Fischer rats, purchased from Experimental Nutrition Laboratory, Federal University of Ouro Preto, were assigned to 4 equal groups, 2 were fed a standard cholesterol-free diet (group C or control and CI or control with iron) containing 8.0% soybean oil and 2 were fed a hyperlipidemic diet (group H or hyperlipidemic and HI or hyperlipidemic with iron) containing 1.0% cholesterol and 25.0% soybean oil. A total of 50 mg of iron was administered to rats in groups CI and HI in 5 equal doses (1 every 3 weeks for a 16-week period) by intraperitoneal injections of 0.1 mL of iron dextran solution (100 g Fe(2+)/L; Sigma, St Louis, Mo). The other rats in groups C and H were treated in a similar manner but with sterile saline (0.1 mL). Irrespective of the diet, iron excess enhanced serum triacylglycerols (P < .05) and reduced serum glucose and glycated hemoglobin levels (P < .05) but did not affect serum cholesterol concentration. Histologic analysis showed steatosis in groups H and to a lesser extent in HI. No significant differences (P > .05) were observed in paraoxonase activities or in serum levels of free or total sulfhydryl radicals, malondialdehyde, or total antioxidants. The findings suggest that iron excess in the rat probably modifies lipid metabolism and, as a consequence, alters glucose homeostasis and increases the level of serum triacylglycerols but not of cholesterol.

Iron overload in hypercholesterolemic rats affects iron homeostasis and serum lipids but not blood pressure.

Epidemiologic and experimental data suggest that excess iron may contribute to the development of cardiovascular diseases (CVD). Because increased LDL cholesterol, decreased HDL cholesterol and alteration of systolic blood pressure (SBP) have all been implicated as risk factors for atherosclerosis and related CVD, the present study was designed to determine whether excess iron alters serum lipids and SBP in control and hypercholesterolemic rats. Female Fischer rats were divided into four groups. The control group (C) was fed the control diet, the CI group was fed the control diet and given iron dextran injections, the hypercholesterolemic group (H) was fed a 1 g/100 g cholesterol diet, and the HI group was fed the cholesterol diet and given iron dextran injections. The rats were fed the diets for 8 wk and iron dextran injections were given during wk 6 at doses of 10 mg/d for 5 d. Excess iron reduced (P < 0.01) plasma total cholesterol in rats fed the cholesterol diet (5.31 +/- 0.83 and 3.17 +/- 0.31 mmol/L for H and HI, respectively). Excess iron also resulted in a redistribution of cholesterol among the various lipoprotein fractions, with an increase (P < 0.01) in HDL cholesterol (0.56 +/- 0.12 and 0.85 +/- 0.16 mmol/L for H and HI, respectively) and a decrease (P < 0.01) in LDL cholesterol (4.49 +/- 0.77 and 2.09 +/- 0.26 mmol/L for H and HI, respectively). This redistribution also occurred in the rats fed the control diet. The treatments did not affect SBP or heart rate. The high cholesterol diet affected iron homeostasis; group H had lower transferrin saturation than group C (P < 0.01); group HI had a lower serum iron concentration than group CI but did not differ from group H (P < 0.05). Therefore, we conclude that if iron has any effect on CVD, it is not through its influence on serum lipids and blood pressure.