Improvement of Endothelial Function by Gunnera Tinctoria Extract With Antioxidant Properties

[Abstract] Background: Gunnera tinctoria has been collected by Mapuche-Pewenche people for food and medicinal purposes. The high polyphenol content of methanolic extract from G. tinctoria leaves with chemical constituents such as ellagic acid and quercetin derivatives suggests its application to prevent endothelial dysfunction and oxidative stress. The aim of this study was to provide evidence of the protective effect of this extract on endothelial function by reducing oxidative stress induced by high D-glucose and H2O2, as well as by stimulating nitric oxide (NO) levels in human umbilical vein endothelial cells (HUVECs). Results: A methanolic extract with a high content of polyphenols (520 ± 30 mg gallic acid equivalents/g dry extract) was obtained from G. tinctoria leaves. Its main constituent was ellagic acid. The results of Ferric reducing antioxidant power and 2,2-diphenyl-1-picrylhydrazyl radical scavenging assays of the extract confirmed its antioxidant activity by inhibition pathway of radical species. The incubation of HUVECs with the extract decreased the apoptosis and reactive oxygen species (ROS) synthesis induced by high extracellular concentration of D-glucose or hydrogen peroxide. The extract increased endothelial NO levels and reduced vasoconstriction in human placental vessels. Conclusions: This study provides evidence about the antioxidant and endothelial protective properties of methanolic G. tinctoria leaf extract. The extract improves the availability of NO in HUVECs, inhibiting the production of ROS and vasoconstriction.Comisión Nacional de Investigación Científica y Tecnológica (Chile); 1191651InnovaChile; 13IDL223120Gobierno Regional del Biobío (Chile); R17A10003Comisión Nacional de Investigación Científica y Tecnológica (Chile); AFB170007Comisión Nacional de Investigación Científica y Tecnológica (Chile); EQM150025Comisión Nacional de Investigación Científica y Tecnológica (Chile); AFB170007Universidad de Concepción (Chile); VRID-Asociativo 213.A84.014-1.0Universidad de Concepción (Chile); VRID-Asociativo 217.033.110-1.0Universidad de Concepción (Chile); VRID-Enlace 216.033.108-1.0This work has been financed by Fondecyt Regular [Grant Number 1191651], InnovaChile [Grant Number 13IDL223120], CIPA, CONICYT Regional, GORE BIO BIO [Grant Number R17A10003], CONICYT PIA/APOYO CCTE [Grant Number AFB170007], Fondequip [Grant Numbers EQM150025 and AFB170007] and Universidad de Concepción, Chile [Grant Numbers VRID-Asociativo 213.A84.014-1.0, VRID-Asociativo 217.033.110-1.0, VRID-Enlace 216.033.108-1.0

Risk-based Evaluation of Treatments for Water Used at a Pre-harvest Stage to Mitigate Microbial Contamination of Fresh Raspberry in Chile

The global agricultural sectors are facing challenges of providing food for a rapidly growing population while still meeting appropriate food quality and safety standards. Chile, a South American country with great climatic and soil diversity, is positioned among the top ten agricultural exporters in the world. Berries are considered highly prioritized produce in terms of microbiological hazards. The work presented in this thesis primarily focuses on the control of microbial contamination in water used at a pre-harvest stage, for enhanced quality and safety of raspberry products in Chile destined for export. Two studies were conducted to achieve the goals. In the first study, a systematic review was carried out to characterize water treatments based on their efficacy of reducing E. coli contamination, and in-field feasibility. The second study employed a quantitative simulation model to analyze the impact of water quality on E. coli contamination on fresh raspberries at the arrival of importers’ border. Compiling findings of the two studies, suggestions on water treatment suitable for raspberry farms were provided. Independent, science-based assessment was conducted and highlighted the most relevant aspects that will help the Chilean food safety authorities with tools to suggest solutions to raspberry producers. Advisor: Bing Wan

Determinación de la concentración de residuos de clortetraciclina y su actividad antimicrobiana en deyecciones de pollos broiler

Memoria para optar al Título Profesional de Médico VeterinarioLa familia de las tetraciclinas, es la segunda familia de antibióticos de mayor producción y uso a nivel mundial. En la industria avícola, son utilizadas para tratar enfermedades infecciosas de origen bacteriano, sin embargo, su uso no está exento de riesgos. Luego de su administración, son excretadas en grandes proporciones a través de orina y heces de humanos y animales de manera activa. Esto resulta relevante debido a que la cama broiler, compuesta en su mayoría por deyecciones de pollo, es utilizada como opción alimenticia para rumiantes. Además, el estiércol es utilizado para optimizar el crecimiento y cosecha en la agricultura, implicando un traspaso de residuos al medio ambiente, generando efectos eco toxicológicos y contribuyendo a la emergencia de resistencia bacteriana. Se llevó a cabo un estudio de depleción utilizando 80 pollos broiler, los cuales fueron tratados con clortetraciclina al 20% en condiciones terapéuticas. El objetivo fue evaluar las concentraciones de clortetraciclina y su epímero 4-epi-clortetraciclina, en las deyecciones de pollos broiler tratados, para lo cual se verificó una metodología analítica mediante cromatografía líquida asociada a un espectrómetro de masas (LC-MS/MS), según la normativa de la Unión Europea. Paralelamente, se llevó a cabo la medición de actividad antimicrobiana mediante un método de “screening”, el cual fue verificado para su uso en deyecciones. Clortetraciclina y su epímero 4-epi-clortetraciclina continuaron excretándose a través de las deyecciones aun cumplido el periodo de resguardo de la formulación farmacéutica en músculo, y sus concetraciones variaron entre 179,5 y 666 μg/kg. Además, del total de muestras analizadas mediante el “screening”, todas presentaron actividad antimicrobiana. Se estableció un tiempo de depleción de 69 días para deyeccionesThe family of tetracyclines, is the second family of antibiotics of greater production and use worldwide. In the poultry industry, they are used to treat infectious diseases of bacterial origin, however, their use is not without risks. After administration, they are excreted in large proportions through urine and feces of humans and animals actively. This is relevant because the poultry litter, composed mostly of poultry excreta, is used as a food option for ruminants. In addition, manure is used to optimize growth and harvesting in agriculture, implying a transfer of waste to the environment, generating ecotoxicological effects and contributing to the emergence of bacterial resistance. A depletion study was carried out using 80 broiler chickens, which were treated with 20% chlortetracycline under therapeutic conditions. The objective was to evaluate the concentrations of chlortetracycline in the excrement of treated broiler chickens, for which an analytical methodology was verified by liquid chromatography associated with a mass spectrometer (LC-MS / MS), according to European Union regulations. At the same time, the measurement of antimicrobial activity was carried out using a screening method, which was verified for use in excreta. The concentrations of chlortetracycline plus its epimer 4-epichlortetracycline varied between 179.5 and 666 μg / kg. Of the total samples analyzed, all of them had antimicrobial activity. A depletion time of 69 days for dejections was establishedFinanciamiento: Proyecto UINICIA 201

Determination of Chlortetracycline Residues, Antimicrobial Activity and Presence of Resistance Genes in Droppings of Experimentally Treated Broiler Chickens

Tetracyclines are important antimicrobial drugs for poultry farming that are actively excreted via feces and urine. Droppings are one of the main components in broiler bedding, which is commonly used as an organic fertilizer. Therefore, bedding becomes an unintended carrier of antimicrobial residues into the environment and may pose a highly significant threat to public health. For this depletion study, 60 broiler chickens were treated with 20% chlortetracycline (CTC) under therapeutic conditions. Concentrations of CTC and 4-epi-CTC were then determined in their droppings. Additionally, this work also aimed to detect the antimicrobial activity of these droppings and the phenotypic susceptibility to tetracycline in E. coli isolates, as well as the presence of tet(A), tet(B), and tet(G) resistance genes. CTC and 4-epi-CTC concentrations that were found ranged from 179.5 to 665.8 µg/kg. Based on these data, the depletion time for chicken droppings was calculated and set at 69 days. All samples presented antimicrobial activity, and a resistance to tetracyclines was found in bacterial strains that were isolated from these samples. Resistance genes tet(A) and tet(B) were also found in these samples

Assessment of Three Antimicrobial Residue Concentrations in Broiler Chicken Droppings as a Potential Risk Factor for Public Health and Environment

Tetracyclines, sulfonamides and amphenicols are broad spectrum antimicrobial drugs that are widely used in poultry farming. However, a high proportion of these drugs can be excreted at high concentrations in droppings, even after the end of a therapy course. This work intended to assess and compare concentrations of florfenicol (FF), florfenicol amine (FFa), chlortetracycline (CTC), 4-epi-chlortetracycline (4-epi-CTC), and sulfachloropyridazine (SCP) in broiler chicken droppings. To this end, 70 chickens were housed under controlled environmental conditions, and assigned to experimental groups that were treated with therapeutic doses of either 10% FF, 20% CTC, or 10% SCP. Consequently, we implemented and designed an in-house validation for three analytical methodologies, which allowed us to quantify the concentrations of these three antimicrobial drugs using liquid chromatography coupled to mass spectrometry (LC-MS/MS). Our results showed that FF and FFa concentrations were detected in chicken droppings up to day 10 after ceasing treatment, while CTC and 4-epi-CTC were detected up to day 25. As for SCP residues, these were detected up to day 21. Noticeably, CTC showed the longest excretion period, as well as the highest concentrations detected after the end of its administration using therapeutic doses

Opinión que se tiene sobre el rol y perfil de la educadora de párvulos en el trabajo con niños y niñas desde el nacimiento a los 4 años en Chile

Tesis (Educación Parvularia, Licenciado en Educación)La Organización Mundial para la Educación Preescolar (OMEP), está desarrollando una investigación acerca de la opinión que se tiene sobre el Rol y el Perfil que debe tener una Educadora de Párvulos que trabaja con niños y niñas desde el nacimiento hasta los 4 años, en Chile y en otros países Latinoamericanos. El presente seminario es un aporte a esta investigación, ya que su objetivo es recoger la opinión que tienen en Chile: los padres de familia o acudientes de Educación Preescolar, Educadoras y Directivos de educación en general, estudiantes de Educación Parvularia de la Universidad Andrés Bello, personas ajenas a la educación y estudiantes de otras áreas, que no tienen vínculo con la educación, de la Universidad Andrés Bello, a través de encuestas y cuestionarios. La información obtenida de este seminario se enviará a la Organización Mundial para la Educación Preescolar, para que ésta sea utilizada y contribuya a la investigación dentro de los países Latinoamericanos y así se conozca la opinión que tienen las personas encuestadas dentro de nuestro país. Es interesante realizar esta investigación para el grupo de seminario, ya que como Educadoras de Párvulos, es relevante conocer la opinión que se tiene sobre la función que se debe cumplir y lo que espera el país de estas profesionales