Descripción del patrón de diferenciación longitudinal de los cromosomas de alpacas y llamas

Publicación a texto completo no autorizada por el autorProporciona información específica acerca de las características estructurales y fisiológicas de los cromosomas de una población de camélidos sudamericanos (CSA), conformada por 28 alpacas y 23 llamas, de ambos sexos, aparentemente sanas, fértiles y procedentes de Alemania, Italia y Perú. Considerando que aún subsisten imprecisiones para identificar de manera inequívoca cada par cromosómico del cariotipo, estimando su morfología, índice centromérico y la longitud relativa de cada cromosoma, siendo estas las dificultades para analizar la problemática reproductiva en estas especies, hemos visto la necesidad de determinar los cariotipos en base a los patrones de diferenciación longitudinal de los cromosomas de alpacas y llamas. En cada ejemplar estudiado, se procedió al cultivo de linfocitos a partir de sangre periférica, etapa realizada en cada país de procedencia y el análisis citogenético en el Laboratorio de Genética Humana de la Facultad de Ciencias Biológica de la Universidad Nacional Mayor de San Marcos. Utilizando las técnicas RBA, CBA, CBG y la coloración con Giemsa, identificamos y clasificamos a cada par cromramsosómico en concordancia con el Sistema Internacional de nomenclatura para los cromosomas humanos. Los cariotipos obtenidos confirmaron el número diploide (2n=74) en ambas especies, observando en alpacas 18 pares subtelocéntricos, 10 submetacéntricos y 9 metacéntricos incluyendo al par sexual. De otro lado, se reporta en llamas 17 pares subtelocéntricos, 10 submetacéntricos y 10 metacéntricos incluyendo al par sexual. Ambas especies describen un patrón de diferenciación sexual del tipo XX/XY. Los cromosomas X e Y de ambas especies son metacéntricos, siendo el cromosoma Y el metacéntrico más pequeño a diferencia de otros autores que lo reportan hasta la actualidad como acrocéntrico. Ambas especies difieren marcadamente en la morfología de los cromosomas 34 y 35 de sus cariotipos respectivos, donde la alpaca presenta a ambos cromosomas como subtelocéntrico (acrocéntrico), mientras que la llama lo presenta como submetacéntrico y metacéntrico respectivamente. Los resultados obtenidos nos permiten proponer los cariotipos de alpacas y llamas, dejando constancia que es necesario que sean confirmados mediante la utilización de secuencias nucleotidicas marcadas con fluorocromos.Consejo Nacional de Ciencia y Tecnología (Perú)  Tesi

Single Cell Determination of7,8-dihydro-8-oxo-2′-deoxyguanosine by FluorescenceTechniques: Antibody vs. Avidin Labeling

An important biomarker of oxidative damage in cellular DNA is the formation of 7,8-dihydro-8-oxo-2′-deoxyguanosine (8-oxodG). Although several methods are available for the bio-chemical analysis of this molecule, its determination at the single cell level may provide significantadvantages when investigating the influence of cell heterogeneity and cell type in the DNA damageresponse. to. For this purpose, antibodies recognizing 8-oxodG are available; however, detectionwith the glycoprotein avidin has also been proposed because of a structural similarity between itsnatural ligand biotin and 8-oxodG. Whether the two procedures are equivalent in terms of reliabilityand sensitivity is not clear. In this study, we compared the immunofluorescence determination of8-oxodG in cellular DNA using the monoclonal antibody N45.1 and labeling using avidin conjugatedwith the fluorochrome Alexa Fluor488 (AF488). Oxidative DNA damage was induced in different celltypes by treatment with potassium bromate (KBrO3), a chemical inducer of reactive oxygen species(ROS). By using increasing concentrations of KBrO3, as well as different reaction conditions, ourresults indicate that the monoclonal antibody N45.1 provides a specificity of 8-oxodG labeling greaterthan that attained with avidin-AF488. These findings suggest that immunofluorescence techniquesare best suited to the in situ analysis of 8-oxodG as a biomarker of oxidative DNA damage

Identification, quantification, and characterization of the phenolic fraction of Brunfelsia grandiflora: In vitro antioxidant capacity

This article belongs to the Special Issue Improvements and Opportunities on Natural Products for Novel Drug Discovery.Brunfelsia grandiflora is an ancient plant widely used for its promising medicinal properties, although little explored scientifically. Despite being a rich source of phenolic compounds responsible in part for the proven anti-inflammatory activity, its characterization has not been carried out to date. The present work deals with the exhaustive identification and quantification of its phenolic fraction, along with its antioxidant activity. Decoction resulting from the bark as fine powder was filtered and lyophilized, and polyphenols were extracted from the resulting product by aqueous-organic solvents. Seventy-nine polyphenols were identified using LC-MSn. Hydroxycinnamates was the most abundant group of compounds (up to 66.8%), followed by hydroxycoumarins (15.5%), lignans (6.1%), flavonols (5.7%), phenolic simples (3.1), gallates (2.3%), flavanols (0.3%), and flavanones (0.2%). About 64% of the characterized phenols were in their glycosylated forms. The quantification of these phytochemicals by LC-QToF showed that this medicinal plant contained 2014.71 mg of phenolic compounds in 100 g dry matter, which evidences a great antioxidant potency determined by ABTS and DPPH assays. Therefore, Brunfelsia grandiflora represents an important source of polyphenols which supports its therapeutic properties scientifically proven.This research was funded by the Project “PCONFIGI A20041391” from the Major National University of San Marcos and the project 202270E021 funded by CSIC.Peer reviewe

In Vitro Neurotoxicity of Flumethrin Pyrethroid on SH-SY5Y Neuroblastoma Cells: Apoptosis Associated with Oxidative Stress

Pyrethroids are neurotoxicants for animals, showing a pattern of toxic action on the nervous system. Flumethrin, a synthetic pyrethroid, is used against ectoparasites in domestic animals, plants, and for public health. This compound has been shown to be highly toxic to bees, while its effects on other animals have been less investigated. However, in vitro studies to evaluate cytotoxicity are scarce, and the mechanisms associated with this effect at the molecular level are still unknown. This study aimed to investigate the oxidative stress and cell death induction in SH-SY5Y neuroblastoma cells in response to flumethrin exposure (1–1000 µM). Flumethrin induced a significant cytotoxic effect, as evaluated by MTT and LDH leakage assays, and produced an increase in the biomarkers of oxidative stress as reactive oxygen species and nitric oxide (ROS and NO) generation, malondialdehyde (MDA) concentration, and caspase-3 activity. In addition, flumethrin significantly increased apoptosis-related gene expressions (Bax, Casp-3, BNIP3, APAF1, and AKT1) and oxidative stress and antioxidative (NFκB and SOD2) mediators. The results demonstrated, by biochemical and gene expression assays, that flumethrin induces oxidative stress and apoptosis, which could cause DNA damage. Detailed knowledge obtained about these molecular changes could provide the basis for elucidating the molecular mechanisms of flumethrin-induced neurotoxicity

Chemical characterization, antioxidant capacity and anti-oxidative stress potential of South American fabaceae Desmodium tortuosum

It has been proposed that oxidative stress is a pathogenic mechanism to induce cytotoxicity and to cause cardiovascular and neuronal diseases. At present, natural compounds such as plant extracts have been used to reduce the cytotoxic effects produced by agents that induce oxidative stress. Our study aimed to evaluate the antioxidant and cytoprotective capacity of Desmodium tortuosum (D. tortuosum) extract in the co- and pre-treatment in EA.hy926 and SH-SY5Y cell lines subjected to oxidative stress induced by tert-butylhydroperoxide (t-BOOH). Cell viability, reactive oxygen species (ROS), nitric oxide (NO), caspase 3/7 activity, reduced glutathione (GSH), glutathione peroxidase (GPx), glutathione reductase (GR), and molecular expression of oxidative stress biomarkers (SOD2, NRF2 and NFκB1) and cell death (APAF1, BAX, Caspase3) were all evaluated. It was observed that the D. tortuosum extract, in a dose-dependent manner, was able to reduce the oxidative and cytotoxicity effects induced by t-BOOH, even normalized to a dose of 200 µg/mL, which would be due to the high content of phenolic compounds mainly phenolic acids, flavonoids, carotenoids and other antioxidant compounds. Finally, these results are indicators that the extract of D. tortuosum could be a natural alternative against the cytotoxic exposure to stressful and cytotoxic chemical agents.The project of Funding number “PCONFIGI A21081221” was funded by the Universidad Nacional Mayor de San Marcos, Lima-Perú.Peer reviewe