Phytochemical Characterization and In Vitro and In Silico Biological Studies from Ferns of Genus Blechnum (Blechnaceae, Polypodiales).

The genus Blechnum represents one of the most ecologically and therapeutically important groups of ferns that grow in tropical, subtropical and temperate regions. In this work, the chemical fingerprint of lyophilized extracts of Blechnum chilense, B. hastatum, B. magellanicum and B. penna-marina species, the determination of their antioxidant activity through ORAC, FRAP and DPPH assays and inhibition of cholinesterase enzymes (AChE and BChE), and an in silico analysis of selected majority compounds on cholinesterase enzymes were identified. Nineteen compounds were recorded for B. chilense, nine in B. hastatum, seventeen in B. magellanicum and seventeen in B. penna-marina by liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UHPLC-ESI-QTOF-MS). The content of phenolic compounds, flavonoids, antioxidant activity and enzyme inhibition were variable among species, with best results for B. penna-marina. Molecular docking evidenced low toxicities, significant pharmacokinetic properties, and significant binding affinities of the tested compounds for the AChE and BChE enzymes. These fern species show high diversity of bioactive compounds and represent a promising resource in phytotherapy, especially for their optimal levels of phenolic compounds that support their antioxidant activity.

Percepciones de los estudiantes de Medicina de la Universidad Nacional de Asunción sobre la salud mental y sobre las barreras para acceder a los servicios de salud mental ofrecidos por la institución / National University of Asunción medical students' perceptions on mental health and on the barriers to accessing mental healthcare services offered by the institution

Introducción: El estudio de las percepciones de los estudiantes de Medicina sobre la salud mental es un tema de investigación significativo, puesto que su conocimiento puede ayudar a comprender las principales barreras a vencer para acceder a servicios de salud mental. Objetivos: Describir la percepción de los estudiantes de Medicina (campus de Sajonia y de San Lorenzo) de la Facultad de Ciencias Médicas de la Universidad Nacional de Asunción sobre los problemas de salud mental y sobre las barreras para acceder a los servicios de atención a la salud mental ofrecidos por la institución. Materiales y métodos: Estudio observacional descriptivo, de corte transversal y temporalmente prospectivo, con muestreo no probabilístico. A través de una encuesta en línea, se examinaron una serie de variables con el fin de describir las percepciones, tales como estigma, actitudes de la Facultad hacia la salud mental y barreras para acceder a los servicios de salud mental. Resultados: 243 estudiantes fueron encuestados. El 24,7 % mencionó haber sido tratado por un problema de salud mental. El 83,13% refirió conocer a algún estudiante con problemas de salud mental en la Facultad. 81,07% indicó que el estigma/vergüenza es la barrera más importante en el acceso a los servicios de salud mental ofrecidos por la institución. El 89,71% sostuvo que la Facultad tiene la responsabilidad de brindar mejor atención a los estudiantes con problemas de salud mental, mientras que el 37,04% estuvo de acuerdo con que la Facultad es amigable con estudiantes con problemas de salud mental. Conclusión: estos hallazgos servirán de base para futuras investigaciones sobre problemas prevalentes de salud mental en los estudiantes de Medicina, incluyendo las maneras de abordarlos y tratarlos, y sobre qué debe hacer la Facultad para mejorar el cuidado de la salud mental de sus estudiantes.

Introduction: The study of the medical students' perceptions on mental health is a significant research topic, since its knowledge can help to understand the main barriers to overcome to access mental healthcare services. Objectives: To describe the perceptions of medical students (Sajonia and San Lorenzo campuses) of the Faculty of Medical Sciences of the National University of Asunción about mental health problems and about the barriers to accessing mental healthcare services offered by the institution. Materials and methods: Descriptive, cross-sectional and temporally prospective observational study, with non-probabilistic sampling. Through an online survey, a series of variables were examined to describe perceptions, such as stigma, Faculty attitudes towards mental health, and barriers to accessing mental healthcare services. Results: 243 students were surveyed. 24.7% mentioned having been treated for a mental health problem. 83.13% reported knowing a student with mental health problems at the Faculty. 81.07% indicated that stigma/shame is the most important barrier in accessing mental healthcare services offered by the institution. 89.71% said that the Faculty has the responsibility to provide better care to students with mental health problems, while 37.04% agreed that the Faculty is friendly with students with mental health problems. Conclusion: These findings will serve as the basis for future research on prevalent mental health problems in medical students, including ways to approach and treat them, and on what the Faculty should do to improve mental healthcare for its students.

Anthraquinone Derivative Reduces Tau Oligomer Progression by Inhibiting Cysteine-Cysteine Interaction.

Tau protein is a natively unfolded protein whose primary role is to participate in axonal transport closely associated with microtubules. Neurodegenerative disorders including Alzheimer's disease and Tauopathies involved tau protein that is found hyperphosphorylated in vivo; then, tau is detached from microtubules to form toxic aggregates or oligomers, which have a deleterious effect on membranes, triggering an inflammatory response. Considering finding tau inhibitors, we isolated two compounds in the ethyl acetate extract from Xanthoria ectaneoides (Nyl.) Zahlbr; ergosterol peroxide (1) and a new anthraquinone (2). We established the structure through spectroscopic data and biogenic considerations, and we named it "2-hydroxy-3-((8-hydroxy-3-methoxy-6-methylanthraquinonyl)oxy)propanoic acid". This new anthraquinone was evaluated as a tau inhibitor by ThT fluorescence, dot blot assays and total internal reflection fluorescence microscopy. Our results strongly suggest that this anthraquinone remodels soluble oligomers and diminishes ß-sheet content. Moreover, through the fluorescence labeling of cysteine inside of the microtubule-binding domain (4R), we showed that this anthraquinone could reduce the oligomers progression by inhibiting cysteine interactions.