The production of backyard chickens is an activity of great importance in the economy of rural families in Paraguay. The Rustipollos population was created through directed crosses between a commercial meat line and a local population belonging to non-specific breeds but phenotypically assimilated to Creole breeds. The aim of this study was to evaluate the genetic diversity, relationship, and structure of Rustipollos using 29 microsatellite markers. Analysis was performed on 50 Rustipollos animals and 926 other individuals as reference breeds/populations from Europe, Africa, South, and North America. A total of 318 alleles were detected, with a mean of 10.97 per locus. The polymorphic information content indicated that 80% of all loci were highly to moderately informative. Only two breeds/populations showed loci that did not deviate from the Hardy–Weinberg equilibrium. The results of genetic diversity indexes suggested moderate levels of genetic variability in Rustipollos population and low inbreeding level. The genetic differentiation index indicates a high genetic differentiation between populations. The results of the Neighbor-Net tree and STRUCTURE analyses indicate the existence of distinct gene pools, with some genetic relationships between Rustipollos, the commercial chicken strain, and south Spanish breeds. The Discriminant Analysis of Principal Components confirmed the observed genetic distances between breeds/populations. The results will be useful for sustainable use and official recognition of this population.

Dengue in Paraguay is an endemic disease of public health importance. Several studies suggest that an increased density of Aedes aegypti and the presence of dengue cases may be associated with climatic conditions. This study aimed to establish the phenotypic variations of Ae. aegypti from four cities (Asunción, Itauguá, Minga Guazú, and Ciudad del Este) and the potential association of environmental variables with the number of eggs in capture sites. Eleven morphometric phenotypic characters were evaluated, and environmental data were obtained from Earth Engine and local meteorological stations. An analysis was carried out using principal component analysis and linear discriminant analysis, and we estimated the correlation using [relative humidity, Normalized Difference Vegetation Index (NDVI) and Normalized Difference Water Index (NDWI)] between variables and the number of eggs in each site. Differences in mean NDVI and NDWI between cities and their relationship with the morphometric performance of individuals were also assessed. The study demonstrated morphometric variations between the populations of Ae. aegypti from two ecoregions, with the Litoral ecoregion populations presented a greater phenotypic variation than those observed in the Alto Paraná ecoregion. Significant statistical associations were registered between the number of eggs with relative humidity (r = –0.45) and the NDVI at 100 meters from the capture points (r = –0.61) for Minga Guazú, and with the NDWI at 100 meters (r = 0.54) for Ciudad del Este. Future studies on these Ae. aegypti populations, and its dispersion could contribute to improve vector control measures and foster future genetic studies.

In this work, we evaluated the antioxidant, toxicological, mutagenic, antigenotoxic and nutritional properties of Oudemansiella cubensis, which is a mushroom found in neotropical regions worldwide and native to Paraguay. Nutritional content analyses revealed that O. cubensis is a rich source of protein, dietary fiber, and fats. Antimicrobial analyses showed antimicrobial activity against Pseudomonas aeruginosa and Enterococcus faecalis. Additionally, the species resulted to be nontoxic for human consumption with an LD50 value of 37.1 mg.mL-1. The ethanolic extract of O. cubensis showcased an important antimutagenic activity at a concentration of 20 mg.mL-1, which promotes the prevention of genotoxic damage. Regarding its chemical profile, Gas Chromatography – Mass Spectrometry confirmed the presence of compounds such as l-(+)-ascorbic acid 2,6-dihexadecanoate, octacosanol and cyclo(l-leucyl-l-prolyl), which stood out for antioxidant and antimicrobial properties. This study provided further evidence that Oudemansiella cubensis is a valuable species because of its potential for biotechnological applications.

The genus Eugenia (Myrtaceae) represents an important source of medicinal species, with documented biological activities attributed to its diverse secondary metabolites, particularly phenolic compounds and terpenoids. However, comprehensive toxicological evaluation remains essential to validate the safety of traditional applications. This research aimed to evaluate the chemical constituents of non-polar fractions and the bioactive potential of Eugenia myrcianthes (Yva hái) leaves. Analyses were performed on hexane, chloroform, and aqueous fractions obtained from the ethanolic extract of the plant material. Phytochemical screening revealed the presence of phenolic compounds, flavonoids, tannins, saponins, and triterpenes/steroids. Gas chromatography-mass spectrometry (GC-MS) identified major bioactive constituents as Delta-cadinene, Alfa-tocopherol, phytol, and squalene in the chloroform fraction, while Tau-muurolol, stigmasterol, Beta-amyrone, and lupenyl acetate were detected in the hexane phase. Bioactivity assessment demonstrated remarkable antioxidant capacity in the aqueous portion (DPPH IC50 = 18.5±0.33 ug.mL-1), contrasting with limited antimicrobial effects against Escherichia coli, Salmonella typhimurium, Staphylococcus epidermidis, and Staphylococcus aureus strains at ?2500 ug.mL-1. Furthermore, no toxicity was detected at ?20 mg.mL-1 using Drosophila melanogaster as a model organism. These findings highlight E. myrcianthes as a promising source of natural antioxidants. Further research into its specific bioactive compounds is necessary to fully assess the plant’s therapeutic potential.

La glicoproteína de la espiga (S) del SARS-CoV2 se encuentra involucrada en el proceso de reconocimiento e infección viral. Debido a esto, la comunidad científica lo considera como blanco para la búsqueda de moléculas bioactivas de origen natural para combatir la Covid-19. Los flavonoides baicaleína y baicalina presentan actividades antivirales contra una gran cantidad de virus, por lo que son buenos candidatos para estudiar su efecto antiviral contra el SARS-CoV2. A fin de identificar y caracterizar in silico las afinidades de interacción de los flavonoides baicaleína y baicalina en el sitio de trimerización de la espiga del SARS-CoV2, se llevaron a cabo pruebas de simulaciones computacionales de acoplamiento molecular entre estos flavonoides y la estructura proteica de la espiga viral en conformaciones cerrada y abierta del ectodominio RBD. Los resultados evidenciaron a la baicaleína en interacción favorable en sitios proximales a la región de trimerización de la proteína, con una ?Gb= -9,12±0,39 kcal.mol-1 y la participación activa de los residuos Arg995, Asp994, Thr998 y Tyr756. Sin embargo, la baicalina demostró afinidad de acoplamiento significativamente favorable (p<0,001) con el sitio de trimerización de esta glicoproteína, con un ?Gb=-9,58±0,18 kcal.mol-1 y la participación activa de los residuos Pro728, Glu780, Ala1020, Leu1024, Lys1028 y Ser1030. Estos hallazgos sugieren que la presencia de ambos flavonoides en interacción con la región de trimerización o en sitios proximales a esta, podrían bloquear el proceso de ensamblaje de esta proteína viral pudiendo interferir con el ciclo replicativo viral, por lo tanto, ambas moléculas pueden ser consideradas como potenciales candidatos para posteriores estudios experimentales.

La enfermedad infecciosa bursal es una patología de origen viral que afecta a aves de corral ocasionando una alta tasa de mortalidad. Las vacunas existentes se enfrentan al problema de la aparición de nuevas cepas, por lo que se realizan búsquedas de moléculas con potencial afinidad de unión a proteínas virales. El extracto de Withania somnífera interviene en la replicación del virus de la bursitis infecciosa, pero el posible mecanismo de acción no es bien conocido. El objetivo de este estudio fue identificar a través de métodos in silico los fitoconstituyentes de W. somnifera con afinidad de unión al sitio activo de la proteína viral 1 (VP1) del virus de la bursitis infecciosa. Se realizaron pruebas de acoplamiento molecular entre la VP1 y 27 fitoconstituyentes descritos en W. somnifera. Los datos de energía de unión obtenidos fueron analizados con el test de Kruskal-Wallis y la prueba de Dunn (p<0.05). Los resultados evidenciaron que los compuestos somniferina, witanólido A, witanólido N, witanólido R, witanólido S y witasomniferol C presentaron energía libre de interacción significativamente favorables (p<0.001) con valores de -8.92±0.15, -7.98±0.20, -7.56±0.28, -8.09±0.01, -8.39±0.01 y -7.99±0.23 kcal.mol-1, respectivamente. Los residuos identificados en las interacciones entre la VP1 y los fitoconstituyentes fueron Arg175, Arg335, Asp402, Asn403, Lys419, Glu421 y Asn493, los cuales poseen funciones cruciales en el proceso de replicación del genoma viral. El fitoconstituyente con mejor resultado de acoplamiento con la VP1 fue la somniferina, la cual demostró afinidades de interacción favorable por el sitio activo de la proteína; sin embargo, se requiere la validación experimental in vitro de estas observaciones.