Bee products as a source of promising therapeutic and chemoprophylaxis strategies against COVID-19 (SARS-CoV-2).

The emergence of novel coronavirus (SARS-CoV-2) in 2019 in China marked the third outbreak of a highly pathogenic coronavirus infecting humans. The novel coronavirus disease (COVID-19) spread worldwide, becoming an emergency of major international concern. However, even after a decade of coronavirus research, there are still no licensed vaccines or therapeutic agents to treat the coronavirus infection. In this context, apitherapy presents as a promising source of pharmacological and nutraceutical agents for the treatment and/or prophylaxis of COVID-19. For instance, several honeybee products, such as honey, pollen, propolis, royal jelly, beeswax, and bee venom, have shown potent antiviral activity against pathogens that cause severe respiratory syndromes, including those caused by human coronaviruses. In addition, the benefits of these natural products to the immune system are remarkable, and many of them are involved in the induction of antibody production, maturation of immune cells, and stimulation of the innate and adaptive immune responses. Thus, in the absence of specific antivirals against SARS-CoV-2, apitherapy could offer one hope toward mitigating some of the risks associated with COVID-19.

Nicotiana benthamiana as a model for studying Cryptococcus-plant interaction.

Cryptococcus gattii, an environmental yeast isolated from plants, is one of the agents of cryptococcosis. Here, we aimed to develop a plant model to study C. gattii-plant interaction, since it is unclear how it affects the plant and the yeast. We tested three inoculation methods (scarification, infiltration, and abrasion) in three plant species: Arabidopsis thaliana, Nicotiana tabacum, and N. benthamiana. Cryptococcus gattii was able to grow in all three models, with a peak of yeast cell burden after 7 days, without any pathological effects. Furthermore, the fungal burden was reduced later, confirming that C. gattii is not a phytopathogen. Cryptococcus gattii proliferation was higher in N. benthamiana, which presented an increase in the hydrogen peroxide content, antioxidant system activity, and indoleacetic acid (IAA) production. Cryptococcus gattii colonies recovered from N. benthamiana presented lower ergosterol content, reduced capsule, and increased growth rate in vitro and inside macrophages. In vitro, IAA altered C. gattii morphology and susceptibility to antifungal drugs. We hypothesize that C. gattii can temporarily colonize plant living tissues, which can be a potential reservoir of yeast virulence, with further dissemination to the environment, birds, and mammals. In conclusion, N. benthamiana is suitable for studying C. gattii-plant interaction.

A 3-alkylpyridine-bearing alkaloid exhibits potent antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA) with no detectable resistance.

Staphylococcus aureus is a Gram-positive bacterium responsible for a wide variety of infectious diseases, and its methicillin-resistant isolates pose a serious worldwide public health risk. New drugs are urgently needed for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections. Here, we evaluated the antibacterial activity of five 3-alkyl-pyridinic analogs against MRSA and, of these compounds, compound 6 showed promising antibacterial activity against Staphylococcus with minimum inhibitory concentration (MIC) ranging from 0.98 to 3.9 µgmL-¹ . In addition, it exhibited a rapid bactericidal action, with complete elimination of MRSA after 6 h of incubation at 15.6 µgmL-¹ . Compound 6 had the ability to damage the bacterial membrane and induce cell lysis and, due to its action on the membrane, showed low resistance induction potential in vitro. In the combination study, compound 6 revealed an additive effect (FICI = 1) with vancomycin and ofloxacin and ciprofloxacin (FICI = 0.75) against MRSA, reducing the effective concentration of this antibiotic two-fold. The anti-staphylococcal activity of compound 6 was stable in the presence of different concentrations of NaCl (50, 200, and 400 µM), trypsin ( 1:500, 1:250) and under a variety of pH values (4, 5, 6, and 8); however, its binding to plasmatic proteins (i.e., albumin) was substantial. The previous exposure of MRSA to the compound was able to reduce the formation of bacterial biofilm and reduce the biomass of mature biofilms. Compound 6 showed low selectivity in vitro for MRSA USA 300 when compared to eukaryotic cells (epithelial, fibroblast, and red blood cells).

Official labeled and unlabeled Brazilian honey. Comparison between physicochemical, microbiological, and microscopic parameters / Miel brasileña oficial etiquetada y no etiquetada. Comparación entre parámetros fisicoquímicos, microbiológicos y microscópicos / Mel brasileiro oficialmente rotulado e não rotulado. Comparação entre parâmetros físico-químicos, microbiológicos e microscópicos

SUMMARY Introduction: Honey is a natural substance produced by bees mainly from flower nectar with high nutritional value. However, many commercialized samples are adulterated or falsified. Method: We bought twelve honey samples in markets in the city of Betim (Brazil) and analyzed their acidity, pH, electrical conductivity, insoluble matter, ashes, moisture content, presence of mesophile bacteria, molds, yeasts, total coliforms, Salmonella spp. and the presence of pollen grains. Results: Considering all honey samples, the average pH was 3.8 ± 0.5 and the average free acidity was 29.8 ± 6.6 mEq/kg. Considering acidity, we found the average of lactonic acidity 6.4 ± 2.4 mEq/kg and a total average acidity of 36.2 ± 6.9 mEq/kg. The average moisture content was 19.4 ± 1.0 %, the average electrical conductivity was 391.6 ± 168.6 μS/ cm, the average amount of ashes was 0.5 ± 0.8 % and the average insoluble matter was 0.08 ± 0.02 %. Only the moisture was significantly different between the two groups and ten honey samples had pollen grains. Conclusions: The quality parameters of the labeled and unlabeled samples were not significantly different, although two samples of unlabeled honey were fraudulent, mainly due to the absence of pollen grains. Identifying the presence or absence of pollen in the samples is a safe, economical, and reliable first step for verifying the authenticity of the honey.

RESUMEN Introducción: La miel es una sustancia natural producida por las abejas, principalmente, a partir del néctar de flores con alto valor nutricional. Sin embargo, muchas muestras comercializadas están adulteradas o falsificadas. Método: Compramos doce mieles en mercados de la ciudad de Betim (Brasil) y analizamos su acidez, pH, conductividad eléctrica, materia insoluble, cenizas, contenido de humedad, presencia de bacterias mesófilas, mohos, levaduras, coliformes totales, Salmonella spp. y la presencia de granos de polen. Resultados: Considerando todas las muestras de miel, el pH promedio fue de 3,8 ± 0,5 y la acidez libre promedio fue de 29,8 ± 6,6 mEq/kg. Considerando la acidez, encontramos el promedio de acidez lactónica 6,4 ± 2,4 mEq/kg y una acidez promedio total de 36,2 ± 6,9 mEq/kg. El contenido de humedad promedio fue 19,4 ± 1,0 %, la conductividad eléctrica promedio fue 391,6 ± 168,6 μS/crn, la cantidad promedio de cenizas fue 0,5 ± 0,8 % y la materia insoluble promedio fue 0,08 ± 0,02 %. Sólo la humedad fue significativamente diferente entre los dos grupos y diez de las muestras de miel tenían granos de polen. Conclusiones: Los parámetros de calidad de las muestras etiquetadas y no etiquetadas no fueron significativamente diferentes, aunque dos muestras de miel no etiquetadas fueron fraudulentas, debido a la ausencia de granos de polen. Identificar la presencia o ausencia de polen en las muestras es un primer paso seguro, económico y confiable para verificar la autenticidad de la miel.

RESUMO Introdução: O mel é uma substância natural produzida pelas abelhas principalmente a partir do néctar da flor com alto valor nutritivo. No entanto, muitas amostras comercializadas são adulteradas ou falsificadas. Método: Compramos doze méis em mercados da cidade de Betim (Brasil) e analisamos sua acidez, pH, condutividade elétrica, sólidos insolúveis, cinzas, teor de umidade, presença de bactérias mesófilas, bolores, leveduras, coliformes totais, Salmonella spp. e a presença de grãos de pólen. Resultados: Considerando todas as amostras de mel, o pH médio foi de 3,8 ± 0,5 e a acidez livre média foi de 29,8 ± 6,6 mEq/kg. Considerando a acidez, encontramos a média de acidez lactô-nica de 6,4 ± 2,4 mEq/kg e uma acidez média total de 36,2 ± 6,9 mEq/kg. O teor de umidade médio foi de 19,4 ± 1,0 %, a condutividade elétrica média foi 391,6 ± 168,6 μS/cm, a quantidade média de cinzas foi 0,5 ± 0,8 % e a matéria insolúvel média foi 0,08 ± 0,02 %. Apenas a umidade foi significativamente diferente entre os dois grupos e dez das amostras de mel apresentaram grãos de pólen. Conclusões: Os parâmetros de qualidade das amostras rotuladas e não rotuladas não foram diferentes, embora duas amostras de mel não rotulado fossem fraudulentas, principalmente devido à ausência de grãos de pólen. Identificar a presença ou ausência de pólen nas amostras é um primeiro passo seguro, económico e confiável para verificar a autenticidade do mel.