Triagem fitoquímica e avaliação da atividade fitotóxica do fruto maduro de Solanum lycocarpum (Solanaceae)

The Solanum lycocarpum species, belonging to the Solanaceae family, is popularly known as the wolf fruit and is used in folk medicine for the treatment of obesity, diabetes, and cholesterol reduction. Thus, the aim of this study was to perform phytochemical screening of the ethanol extract from the ripe fruit of S. lycocarpum to verify the presence of the main groups of secondary metabolites and to evaluate the phytotoxic effect on Lactuca sativa (lettuce) and Allium cepa (onion) seeds. The fruits of S. lycocarpum were collected, crushed and percolated with anhydrous ethanol and the solvent was dried in a rotatory evaporator to obtain the ethanol extract. In the phytotoxicity evaluation, the results showed that the ethanol extract was able to completely inhibit the growth of hypocotyl and radicle of L. sativa (lettuce) seeds in all concentrations tested. In A. cepa (onion) seeds, a concentration of 500 μg per plate was able to inhibit the growth of the hypocotyl and radicle by 100%. The metabolites detected in the extract were alkaloids, coumarins, flavonoids, and condensed tannins. The phytotoxic activity can be correlated to the presence of these compounds.A espécie Solanum lycocarpum, pertencente à família Solanaceae, é conhecida popularmente como lobeira ou fruto do lobo e utilizada na medicina popular para o tratamento da obesidade, do diabetes e na redução do colesterol. Desta forma, o objetivo deste estudo foi realizar a triagem fitoquímica do extrato etanólico do fruto maduro de S. lycocarpum para verificar a presença dos principais grupos de metabólitos secundários e avaliar o efeito fitotóxico sobre sementes de Lactuca sativa (alface) e de Allium cepa (cebola). Os frutos de S. lycocarpum foram coletados, triturados e extraídos por percolação com etanol anidro e, o solvente foi secado em evaporador rotatório, obtendo-se o extrato etanólico. Na avaliação da fitotoxicidade, os resultados demonstraram que o extrato etanólico foi capaz de inibir completamente o crescimento do hipocótilo e da radícula de sementes de L. sativa (alface), em todas as concentrações testadas. Nas sementes de A. cepa (cebola), a concentração de 500 μg por placa foi capaz de inibir em 100% o crescimento do hipocótilo e da radícula. Os metabólitos detectados no extrato foram alcaloides, cumarinas, flavonoides e taninos condensados. A atividade fitotóxica pode ser correlacionada à presença desses compostos

Drug repurposing clinical trials in the search for life-saving COVID-19 therapies; research targets and methodological and ethical issues

Introduction: So far, there is no vaccine, nor are there effective drugs to treat COVID-19, an emerging viral respiratory infection deadlier than influenza. Objective: To take a snapshot picture of planned and ongoing clinical research addressing drugs potentially useful for treating SAR-CoV-2 infections. Method: A search was conducted (20 April 2020) in an international registry of clinical studies (https://ClinicalTrials.gov, US NIH). After excluding observational studies and other interventions that fell outside the scope of this study, 294 research protocols (out of 516 retrieved protocols) were selected for analysis. Results: Of 294 included trials, 249 were Randomized Controlled Trials (RCT), 118 of which were double-, triple- or quadruple-blinded studies. The interventions (drug therapies) were compared with “standard-of-care” (SOC) or with the placebo plus SOC, or yet with presumed “active” comparators. RCT focused on the primary treatment of the disease (inhibitors of viral replication) or on the therapy for resolution of hyperinflammation in pneumonia/Acute Respiratory Distress Syndrome (ARDS) and thromboembolism associated with SARS-CoV-2. The trials found in the database involve existing antiviral compounds and drugs with multiple modes of antiviral action. Antiparasitic drugs, which inhibited viral replication in cell-culture assays, are being tested as well. Regarding the adjunctive immunomodulatory, anti-inflammatory and antithrombotic therapies, a number of drugs with distinct pharmacological targets are under investigation in trials enrolling patients with severe COVID-19. Conclusions: Although many clinical studies of drugs for COVID-19 are planned or in progress, only a minority of them are sufficiently large, randomized and placebo-controlled trials with masking and concealment of allocation. Owing to methodological limitations, only a few clinical trials found in the registry are likely to yield robust evidence of effectiveness and safety of drugs repurposable for COVID-19.TÍTULO PT: Ensaios clínicos para reposicionamento de medicamentos para COVID-19 na busca de terapias para salvar vidas; alvos de pesquisa, e questões metodológicas e éticas Introdução: Até agora, não há vacinas ou medicamentos eficazes para tratar COVID-19, uma infecção viral respiratória emergente mais letal do que a gripe. Objetivo: Desenhar um quadro das pesquisas planejadas e em curso sobre medicamentos potencialmente úteis para tratar infecções por SARS-CoV-2. Método: Um levantamento foi realizado (20 de abril de 2020) em um registro internacional de estudos clínicos (https://ClinicalTrials.gov, US NIH). Após excluir estudos observacionais e outras interveções fora do escopo deste estudo, 294 protocolos (de 516 identificados na busca) foram selecionados para análise. Resultados: De 294 ensaios incluídos, 249 eram Ensaios Controlados Randomizados (ECR), dos quais 118 eram estudos duplo-, triplo- ou quadruplo-cego. As intervenções (medicamentos testados) foram comparadas com o “tratamento padrão” (TP) ou com placebo mais TP, ou ainda com comparadores supostamente ativos. ECR abordaram o tratamento primário da doença (inibidores da replicação viral) ou a resolução da super-inflamação na pneumonia e Síndrome do Desconforto Respiratório Agudo (SDRA), e do tromboembolismo associados ao SARS-CoV-2. Os ensaios localizados no registro envolviam fármacos antivirais com múltiplos modos de ação e medicamentos anti-parasitários que inibem a replicação viral em cultura de células. Em relação às terapias imunomodulatória, antiinflamatória e antitrombótica adjuvantes, inúmeros medicamentos com alvos farmacológicos distintos também estão sendo investigados em ensaios envolvendo pacientes graves com COVID-19. Conclusões: Embora muitos ensaios clínicos de medicamentos para COVID-19 tenham sido planejados e estejam em andamento, apenas uma minoria deles são estudos suficientemente grandes, randomizados, controlados com placebo e com mascaramento, e ocultação da alocação. Em virtude das limitações metodológicas apontadas, provavelmente apenas uns poucos ensaios clínicos fornecerão evidências robustas da eficácia e segurança de medicamentos potencialmente redirecionáveis para COVID-19

Dedifferentiation of prostate smooth muscle cells in response to bacterial LPS

Prostate smooth muscle cells (SMCs) are strongly involved in the development and progression of benign prostatic hyperplasia and prostate cancer. However, their participation in prostatitis has not been completely elucidated. Thus, we aimed to characterize the response of normal SMC to bacterial lipopolysaccharide (LPS). Methods Primary prostate SMCs from normal rats were stimulated with LPS (0.1, 1, or 10Âμg/ml) for 24 or 48hr. The phenotype was evaluated by electron microscopy, immunofluorescence, and Western blot of SMCα-actin (ACTA2), calponin, vimentin, and tenascin-C, while the innate immune response was assessed by immunodetection of TLR4, CD14, and nuclear NF-κB. The secretion of TNFα and IL6 was determined using ELISA. Results Bacterial LPS induces SMCs to develop a secretory phenotype including dilated rough endoplasmic reticulum cisternae with well-developed Golgi complexes. Furthermore, SMCs displayed a decrease in ACTA2 and calponin, and an increase in vimentin levels after LPS challenge. The co-expression of ACTA2 and vimentin, together with the induction of tenascin-C expression indicate that a myofibroblastic-like phenotype was induced by the endotoxin. Moreover, LPS elicited a TLR4 increase, with a peak in NF-κB activation occurring after 10min of treatment. Finally, LPS stimulated the secretion of IL6 and TNFα. ConclusionS Prostate SMCs are capable of responding to LPS in vitro by dedifferentiating from a contractile to a miofibroblastic-like phenotype and secreting cytokines, with the TLR4 signaling pathway being involved in this response. In this way, prostate SMCs may contribute to the pathophysiology of inflammatory diseases by modifying the epithelial-stromal interactions.Fil: Leimgruber, Carolina. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Ciencias de la Salud. Universidad Nacional de Córdoba. Instituto de Investigaciones en Ciencias de la Salud; ArgentinaFil: Quintar, Amado A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Ciencias de la Salud. Universidad Nacional de Córdoba. Instituto de Investigaciones en Ciencias de la Salud; Argentina. Universidad Nacional de Córdoba; ArgentinaFil: Sosa, Liliana del Valle. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Ciencias de la Salud. Universidad Nacional de Córdoba. Instituto de Investigaciones en Ciencias de la Salud; ArgentinaFil: García, Luciana Noemí. Universidad Nacional de Córdoba; Argentina. Centro de Investigación de la Fundación Repro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Figueredo, Carlos Mauricio. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Maldonado, Cristina Alicia. Universidad Nacional de Córdoba. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Ciencias de la Salud. Universidad Nacional de Córdoba. Instituto de Investigaciones en Ciencias de la Salud; Argentin

Mitochondrial Cumulative Damage Induced by Mitoxantrone: Late Onset Cardiac Energetic Impairment

Mitoxantrone (MTX) is a chemotherapeutic agent, which presents late irreversible cardiotoxicity. This work aims to highlight the mechanisms involved in the MTX-induced cardiotoxicity, namely the effects toward mitochondria using in vivo and in vitro studies. Male Wistar rats were treated with 3 cycles of 2.5 mg/kg MTX at day 0, 10, and 20. One treated group was euthanized on day 22 (MTX22) to evaluate the early MTX cardiac toxic effects, while the other was euthanized on day 48 (MTX48), to allow the evaluation of MTX late cardiac effects. Cardiac mitochondria isolated from 4 adult untreated rats were also used to evaluate in vitro the MTX (10 nM, 100 nM, and 1 lM) direct effects upon mitochondria functionality. Two rats of MTX48 died on day 35, and MTX treatment caused a reduction in relative body weight gain in both treated groups with no significant changes in water and food intake. Decreased levels of plasma total creatine kinase and CK-MB were detected in the MTX22 group, and increased plasma levels of lactate were seen in MTX48. Increased cardiac relative mass and microscopic changes were evident in both treated groups. Considering mitochondrial effects, for the first time, it was evidenced that MTX induced an increase in the complex IV and complex V activities in MTX22 group, while a decrease in the complex V activity was accompanied by the reduction in ATP content in the MTX48 rats. No alterations in mitochondria transmembrane potential were found in isolated mitochondria from MTX48 rats or in isolated mitochondria directly incubated with MTX. This study highlights the relevance of the cumulative MTX-induced in vivo mitochondriopathy to the MTX cardiotoxicity.This work was supported by the Fundação para a Ciência e Tecnologia (FCT)—project (EXPL/DTP-FTO/0290/ 2012)—QREN initiative with EU/FEDER financing through COMPETE— Operational Programme for Competitiveness Factors. LGR, VMC, and RJD-O thank FCT for their PhD Grant (SFRH/BD/63473/ 2009) and Post-doc Grants (SFRH/BPD/63746/2009) and (SFRH/ BPD/36865/2007), respectively. The authors are grateful to Fundação para a Ciência e Tecnologia for grant no. Pest C/EQB/LA0006/2011

Linking shifts in bacterial community with changes in dissolved organic matter pool in a tropical lake

Bacterioplankton communities have a pivotal role in the global carbon cycle. Still the interaction between microbial community and dissolved organic matter (DOM) in freshwater ecosystems remains poorly understood. Here, we report results from a 12-day mesocosm study performed in the epilimnion of a tropical lake, in which inorganic nutrients and allochthonous DOM were supplemented under full light and shading. Although the production of autochthonous DOM triggered by nutrient addition was the dominant driver of changes in bacterial community structure, temporal covariations between DOM optical proxies and bacterial community structure revealed a strong influence of community shifts on DOM fate. Community shifts were coupled to a successional stepwise alteration of the DOM pool, with different fractions being selectively consumed by specific taxa Typical freshwater clades as Limnohabitans and Sporichthyaceae were associated with consumption of low molecular weight carbon, whereas Gammaproteobacteria and Flavobacteria utilized higher molecular weight carbon, indicating differences in DOM preference among Glades. Importantly. Verrucomicrobiaceae were important in the turnover of freshly produced autochthonous DOM, ultimately affecting light availability and dissolved organic carbon concentrations. Our findings suggest that taxonomically defined bacterial assemblages play definite roles when influencing DOM fate, either by changing specific fractions of the DOM pool or by regulating light availability and DOC levels. (C) 2019 Elsevier B.V. All rights reserved.Peer reviewe

Forecasting maize yield at field scale based on high-resolution satellite imagery

Estimating maize (Zea mays L.) yields at the field level is of great interest to farmers, service dealers, and policy-makers. The main objectives of this study were to: i) provide guidelines on data selection for building yield forecasting models using Sentinel-2 imagery; ii) compare different statistical techniques and vegetation indices (VIs) during model building; and iii) perform spatial and temporal validation to see if empirical models could be applied to other regions or when models' coefficients should be updated. Data analysis was divided into four steps: i) data acquisition and preparation; ii) selection of training data; iii) building of forecasting models; and iv) spatial and temporal validation. Analysis was performed using yield data collected from 19 maize fields located in Brazil (2016 and 2017) and in the United States (2016), and normalized vegetation indices (NDVI, green NDVI and red edge NDVI) derived from Sentinel-2. Main outcomes from this study were: i) data selection impacted yield forecast model and fields with narrow yield variability and/or with skewed data distribution should be avoided; ii) models considering spatial correlation of residuals outperformed Ordinary least squares (OLS) regression; iii) red edge NDVI was most frequently retained into the model compared with the other VIs; and iv) model prediction power was more sensitive to yield data frequency distribution than to the geographical distance or years. Thus, this study provided guidelines to build more accurate maize yield forecasting models, but also established limitations for up-scaling, from farm-level to county, district, and state-scales.Publicado originalmente en: Rai A. Schwalbert, Telmo J.C. Amado, Luciana Nieto, Sebastian Varela, Geomar M. Corassa, Tiago A.N. Horbe, Charles W. Rice, Nahuel R. Peralta, Ignacio A. Ciampitti. Forecasting maize yield at field scale based on high-resolution satellite imagery. Biosystem Engineering. 171: 179–192 DOI: https://doi.org/10.1016/j.biosystemseng.2018.04.020Sociedad Argentina de Informática e Investigación Operativ

Unauthorized Horizontal Spread in the Laboratory Environment: The Tactics of Lula, a Temperate Lambdoid Bacteriophage of Escherichia coli

We investigated the characteristics of a lambdoid prophage, nicknamed Lula, contaminating E. coli strains from several sources, that allowed it to spread horizontally in the laboratory environment. We found that new Lula infections are inconspicuous; at the same time, Lula lysogens carry unusually high titers of the phage in their cultures, making them extremely infectious. In addition, Lula prophage interferes with P1 phage development and induces its own lytic development in response to P1 infection, turning P1 transduction into an efficient vehicle of Lula spread. Thus, using Lula prophage as a model, we reveal the following principles of survival and reproduction in the laboratory environment: 1) stealth (via laboratory material commensality), 2) stability (via resistance to specific protocols), 3) infectivity (via covert yet aggressive productivity and laboratory protocol hitchhiking). Lula, which turned out to be identical to bacteriophage phi80, also provides an insight into a surprising persistence of T1-like contamination in BAC libraries

AVALIAÇÃO DA ATIVIDADE ANTIFÚNGICA DOS FRUTOS VERDES E MADUROS DE Solanum lycocarpum FRENTE À Candida albicans e Candida krusei

A espécie Solanum lycocarpum é usada na medicina popular e possui atividade antibacteriana descrita na literatura. O objetivo do estudo foi avaliar a atividade antifúngica dos frutos de S. lycocarpum frente a Candida albicans (ATCC 18804) e Candida krusei (ATCC 20298). Os frutos maduros e verdes foram coletados, extraídos em Sohxlet, obtendo-se o extrato etéreo dos frutos verdes e o extrato etéreo dos frutos maduros, que assim como o antifúngico cetoconazol, a combinação (extratos e cetoconazol) foram testados em concentrações entre 15-2000 g/mL e determinada a Concentração Inibitória Mínima e a Concentração Fungicida Mínima. A combinação do extrato etéreo dos frutos verdes e cetoconazol e do extrato etéreo dos frutos maduros e cetoconazol exibiram atividade antifúngica frente as duas espécies de Candida, principalmente frente a C. albicans, destacando o efeito sinérgico entre o extrato etéreo dos frutos maduros e cetoconazol (CIM e CFM de 15 g/mL). Os resultados demonstram a ação antifúngica para os frutos verdes e maduros de S. lycocarpum.