Polysaccharide Nanoparticles from Isatis indigotica Fort. Root Decoction: Diversity, Cytotoxicity, and Antiviral Activity

It has been revealed that numerous nanoparticles are formed during the boiling preparation of traditional Chinese medical decoctions and culinary soups. They may possess physiological effects different from those of constituent components and are worth paying attention to but are barely noticed and investigated as of yet. In this study, six groups of nanoparticles, whose size ranged from 57 to 300 nm, were successfully isolated from the decoction of Isatis indigotica Fort. root, according to their particle size by the means of size-exclusive chromatography. All of the obtained nanoparticles have a high content of polysaccharides, which distinguishes them from the disclosed BLG protein nanoparticles. They also have high similarities in other compositions, surface charge, and stimuli responses. However, four out of these six nanoparticles (F2, F3, F4, and F5) exhibited significant antiviral activity against influenza virus H1N1, and their antiviral activities and cytotoxicity towards MDCK cells varied with their sizes. It suggested that the antiviral efficacy of BLG decoction could also be from its nanoparticles besides its well-known antiviral phytochemicals. It also implied that the biological effects of these polysaccharide nanoparticles, including cytotoxicity and antiviral activity, may be correlative with the physicochemical properties, especially the particle size.

Riesgo de sesgo de publicación en intervenciones terapéuticas para la COVID-19

En este artículo se describe el sesgo de publicación, sus causas más frecuentes, sus características, las herramientas regulatorias para evitarlo y algunas técnicas estadísticas para analizarlo. Se explican y aplican estas técnicas a tres intervenciones terapéuticas relacionadas con la enfermedad por el coronavirus 2019 (COVID-19, por su sigla en inglés): corticoides, ivermectina y tocilizumab; se detectó riesgo de sesgo de publicación para ivermectina y tocilizumab. Las revisiones sistemáticas y los metaanálisis son diseños de investigación secundaria que constituyen una referencia para guiar la toma de decisiones. Son propensos a distintos tipos de sesgo, que es una desviación sistemática en los resultados. Aun desarrollados con rigor metodológico, su validez puede verse amenazada por el sesgo de publicación. Este se define como el acto de ocultar o retrasar la publicación, retener datos surgidos de los estudios de investigación, o ambos. Hasta la mitad de los ensayos controlados que se realizan permanecen sin publicarse. Durante la pandemia por virus H1N1, el sesgo de publicación de estudios financiados por la industria llevó a recomendar y comprar en gran escala el fármaco oseltamivir que, luego se supo, no tenía efectos beneficiosos relevantes. Dos tercios del financiamiento de los estudios clínicos para COVID-19 provienen de la industria farmacéutica. En el contexto de la pandemia actual por COVID-19, se publican estudios a un ritmo acelerado, por lo que resulta de gran trascendencia conocer e identificar el sesgo de publicación. Para reducir el sesgo de publicación es necesario regular el registro y la publicación de ensayos clínicos, pero esto requiere una coordinación de los países y organismos internacionales. Es importante sospechar e intentar identificar el sesgo de publicación para la toma de decisiones.

Influenza A Virus (H1N1) Infection Induces Microglial Activation and Temporal Dysbalance in Glutamatergic Synaptic Transmission

Influenza A virus (IAV) causes respiratory tract disease and is responsible for seasonal and reoccurring epidemics affecting all age groups. Next to typical disease symptoms, such as fever and fatigue, IAV infection has been associated with behavioral alterations presumably contributing to the development of major depression.

Influenza A Virus (H1N1) Infection Induces Glycolysis to Facilitate Viral Replication

Viruses depend on host cellular metabolism to provide the energy and biosynthetic building blocks required for their replication. In this study, we observed that influenza A virus (H1N1), a single-stranded, negative-sense RNA virus with an eight-segmented genome, enhanced glycolysis both in mouse lung tissues and in human lung epithelial (A549) cells. In detail, the expression of hexokinase 2 (HK2), the first enzyme in glycolysis, was upregulated in H1N1-infected A549 cells, and the expression of pyruvate kinase M2 (PKM2) and pyruvate dehydrogenase kinase 3 (PDK3) was upregulated in H1N1-infected mouse lung tissues. Pharmacologically inhibiting the glycolytic pathway or targeting hypoxia-inducible factor 1 (HIF-1), the central transcriptional factor critical for glycolysis, significantly reduced H1N1 replication, revealing a requirement for glycolysis during H1N1 infection. In addition, pharmacologically enhancing the glycolytic pathway further promoted H1N1 replication. Furthermore, the change of H1N1 replication upon glycolysis inhibition or enhancement was independent of interferon signaling. Taken together, these findings suggest that influenza A virus induces the glycolytic pathway and thus facilitates efficient viral replication. This study raises the possibility that metabolic inhibitors, such as those that target glycolysis, could be used to treat influenza A virus infection in the future.

Methylene Blue has a potent antiviral activity against SARS-CoV-2 and H1N1 influenza virus in the absence of UV-activation in vitro

Methylene blue is an FDA (Food and Drug Administration) and EMA (European Medicines Agency) approved drug with an excellent safety profile. It displays broad-spectrum virucidal activity in the presence of UV light and has been shown to be effective in inactivating various viruses in blood products prior to transfusions. In addition, its use has been validated for methemoglobinemia and malaria treatment. In this study, we first evaluated the virucidal activity of methylene blue against influenza virus H1N1 upon different incubation times and in the presence or absence of light activation, and then against SARS-CoV-2. We further assessed the therapeutic activity of methylene blue by administering it to cells previously infected with SARS-CoV-2. Finally, we examined the effect of co-administration of the drug together with immune serum. Our findings reveal that methylene blue displays virucidal preventive or therapeutic activity against influenza virus H1N1 and SARS-CoV-2 at low micromolar concentrations and in the absence of UV-activation. We also confirm that MB antiviral activity is based on several mechanisms of action as the extent of genomic RNA degradation is higher in presence of light and after long exposure. Our work supports the interest of testing methylene blue in clinical studies to confirm a preventive and/or therapeutic efficacy against both influenza virus H1N1 and SARS-CoV-2 infections.

Perfil clínico de crianças internadas com vírus sincicial respiratório (VSR): análise em uma cidade do interior paulista de 2016 a 2017

Objetivo: Identificar e comparar o perfil epidemiológico e clínico de crianças com desconforto respiratório que realizaram teste rápido para VSR e/ou swab para o vírus H1N1 entre 2016 e 2017. Métodos: Os dados foram coletados do livro de controle dos testes para VSR e prontuários em um hospital no interior de São Paulo. Foram incluídas crianças menores de dois anos, com desconforto respiratório, que realizaram o teste para VSR e/ou swab para o vírus H1N1, de abril a junho de 2016 e 2017. Para análise estatística foram utilizados os testes Exato de Fisher e Mann-Whitney (significativo P=<0,05). Resultados: Em 2016, 84 crianças foram incluídas, com idade média de 6.1 meses, 42.9% apresentaram VSR positivo. Destas, 33.3% (P=0.0010) internaram na UTI, com tendência de maior uso (P=0.0933) e tempo em ventilação mecânica (P=0.0456). Em 2017, foram incluídas 165 crianças, com média de idade de 6.4 meses, 49.1% apresentaram VSR positivo. Destas, 86.1% (P=0.002) foram diagnosticadas com bronquiolite, 24.7% (P=0.031) utilizaram inalação hipertônica e 56.8% (P=0.016) oxitenda. Conclusão: A incidência do VSR foi maior em 2017, embora, em 2016, os pacientes com VSR positivo tenham internado com maior frequência em UTI, apresentando tempo mais prolongado e uso mais frequente da ventilação mecânica.

Lung Neutrophilic Recruitment and IL-8/IL-17A Tissue Expression in COVID-19

The new SARS-CoV-2 virus differs from the pandemic Influenza A virus H1N1 subtype (H1N1pmd09) how it induces a pro-inflammatory response in infected patients. This study aims to evaluate the involvement of SNPs and tissue expression of IL-17A and the neutrophils recruitment in post-mortem lung samples from patients who died of severe forms of COVID-19 comparing to those who died by H1N1pdm09. Twenty lung samples from patients SARS-CoV-2 infected (COVID-19 group) and 10 lung samples from adults who died from a severe respiratory H1N1pdm09 infection (H1N1 group) were tested. The tissue expression of IL-8/IL-17A was identified by immunohistochemistry, and hematoxylin and eosin (H&amp;E) stain slides were used for neutrophil scoring. DNA was extracted from paraffin blocks, and genotyping was done in real time-PCR for two IL17A target polymorphisms. Tissue expression increasing of IL-8/IL-17A and a higher number of neutrophils were identified in samples from the H1N1 group compared to the COVID-19 group. The distribution of genotype frequencies in the IL17A gene was not statistically significant between groups. However, the G allele (GG and GA) of rs3819025 was correlated with higher tissue expression of IL-17A in the COVID-19 group. SARS-CoV-2 virus evokes an exacerbated response of the host’s immune system but differs from that observed in the H1N1pdm09 infection since the IL-8/IL-17A tissue expression, and lung neutrophilic recruitment may be decreased. In SNP rs3819025 (G/A), the G allele may be considered a risk allele in the patients who died for COVID-19.