Efecto antiviral de bifidobacterium longum y chlorella sorokiniana en un modelo de infección in vitro

Los suplementos alimenticios con probióticos y prebióticos ha mostrado su potencial preventivo de infecciones por patógenos entéricos, debido a su capacidad de competir con receptores y sitios de adhesión en el intestino y a la modulación de la respuesta inmune. Ciertos virus patógenos entéricos poseen variaciones antigénicas y pueden producir proteínas que interfieren con la respuesta inmune innata del huésped, inhibiendo la vía de señalización de interferones (INFs), evadiendo la respuesta inmune incluso después de la vacunación. Por esto es necesario buscar alternativas para controlar este tipo de virus, y reducir la severidad sintomatológica por estos patógenos. En el presente trabajo se evaluó el efecto antiviral del probiótico Bifidobacterium longum y del prebiótico Chlorella sorokiniana en células HT-29 infectadas con Rotavirus wa. El efecto citopático de rotavirus en células HT-29 contra células no infectadas, mostró que con C. sorokiniana se redujo 10 % en la pre-infección a las 24 h y 20 % en la post-infección. Cuando las células se trataron con B. longum, se redujo hasta en un 20 % en la pre-infección y en la post-infección en 30%. Los niveles de expresión de INF- , IRF-3, IRF-5. RIG-1 y SOCS3 aumentaron significativamente (p < 0.05) en células HT29 infectadas con Rotavirus wa tratadas en combinación con C. sorokiniana y B. longum en la pre-infección, en comparación con células no infectadas. En conclusión, la combinación de C. sorokiniana y B. longum favorecen la expresión de citocinas encargadas de inducir la activación de la respuesta antiviral celular, esto permite disminuir el efecto citopático ocasionado por rotavirus. Abstract Food supplements with probiotics and prebiotics have shown their preventive potential for enteric pathogen infections, because of their potential to compete with receptors and adhesion sites in the intestine and modulate the immune response. Several enteric pathogenic viruses possess antigenic variations and produce proteins that interfere with the host innate immune response, inhibiting the interferon (INFs) signaling pathway and evading the immune response even after vaccination. Therefore, it is necessary to search for alternatives to control this type of virus and reduce the symptomatic severity of these pathogens. In the present study, the antiviral effect of the probiotic Bifidobacterium longum and the prebiotic Chlorella sorokiniana in HT-29 cells infected with Rotavirus wa was evaluated. The cytopathic effect of rotavirus in HT-29 cells against uninfected cells showed that with C. sorokiniana the pre-infection was reduced by 10% at 24 h and the post-infection by 20%. When the cells were treated with B. longum, it was reduced in pre-infection by up to 20% and in post-infection by 30%. Expression levels of INF-α, IRF-3, IRF-5. RIG-1 and SOCS3 significantly (p <0.05) increased in HT-29 cells infected with Rotavirus wa treated in combination with C. sorokiniana and B. longum in pre-infection, compared to uninfected cells. In conclusion, combination of C. sorokiniana and B. longum favors expression of cytokines responsible for inducing cellular antiviral response activation, allowing to reduce rotavirus-mediated cytopathic effect

In Vitro Antitumor Activity of Endophytic and Rhizosphere Gram-Positive Bacteria from Ibervillea sonorae (S. Watson) Greene against L5178Y-R Lymphoma Cells

Plant-associated microorganisms represent a potential source of new antitumor compounds. The aim of the present study was to isolate endophytic and rhizosphere Gram-positive bacteria from Ibervillea sonorae and produce extracts with antitumor activity. Methanol and ethyl acetate extracts were obtained from 28 d bacterial fermentation, after which murine L5178Y-R lymphoma cells growth inhibition was evaluated at concentrations ranging from 15.62 &micro;g/mL to 500 &micro;g/mL by the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide reduction colorimetric assay. IC50 and the selectivity index (SI) were calculated and compared with healthy control human peripheral blood mononuclear cells (PBMC). Identification of the isolated strains was performed using the 16S ribosomal gene and by MALDI-TOF MS mass spectrometry. The endophytic and rhizosphere bacterial extracts from strains ISE-B22, ISE-B26, ISE-B27, ISS-A01, ISS-A06, and ISS-A16 showed significant (p &lt; 0.05) L5178Y-R cell growth inhibition, compared with an untreated control. The rhizosphere Micromonospora echinospora isolate ISS-A16 showed the highest (90.48%) percentage of lymphoma cells growth inhibition and SI (19.1) for PBMC, whereas the Bacillus subtilis ISE-B26 isolate caused significant (p &lt; 0.01) growth inhibition (84.32%) and a SI of 5.2. Taken together, results of the present study evidenced antitumor effects by I. sonorae endophytic and rhizosphere bacteria culture extracts. Further research will involve the elucidation of the compounds that exert the antitumor activity and their evaluation in pre-clinical studies

In Vitro Tumor Cell Growth Inhibition Induced by Lophocereus marginatus (DC.) S. Arias and Terrazas Endophytic Fungi Extracts

Endophytic fungi have become potential sources of antitumor agents, particularly against antineoplastic-resistant cancer cells, with marginal or nil adverse effects for the oncological patient. Endophytic fungi were isolated from stems of the Lophocereus marginatus cactus, commonly found in Mexico. Methanol extracts were then obtained from fungus liquid cultures and their effects on tumor cell growth against murine lymphoma (L5178Y-R), human colorectal adenocarcinoma (HT-29), and human breast cancer (MCF-7) cells were evaluated at concentrations ranging from 31 µg/mL to 250 µg/mL via the colorimetric 3- [4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazoliumbromide reduction assay, using monkey kidney epithelial (MA-104) and human peripheral mononuclear (PBMC) cells as controls. Furthermore, we obtained the IC50 and the selectivity index (SI) was calculated from the IC50 ratio of normal and tumor cells. In addition, molecular identification of fungi showing cytotoxic activity was determined, using internal transcribed spacer molecular markers. PME-H001, PME-H002, PME-H005, PME-H007, and PME-H008 filamentous fungus strain extracts showed significant (p &lt; 0.05) tumor cell growth inhibition. In particular, they significantly (p &lt; 0.05) inhibited L5178Y-R cell growth, whereas the least susceptible cell line was HT-29. The endophytic strain PME-H008 of Cladosporium sp. caused the highest growth inhibition percentage against L5178Y-R and HT-29 cells with 96.6% (p &lt; 0.01) and 42.5% (p &lt; 0.05) respectively, and the highest SIs against L5178Y-R cells with 2.4 and 2.9 for MA-104 and PBMCs, respectively, whereas the PME-H005 extract showed SIs of 2.77 and 1.5 against MCF-7 and L5178Y-R cells, respectively, as compared with PBMCs. In addition, the endophytic strain PME-H007 of Metarhizium anisopliae caused the highest percentage of growth inhibition (p &lt; 0.01) against MCF-7 cells with 55.8% at 250 µg/mL. We demonstrated in vitro antitumor effects of L. marginatus endophytic fungi. Further research will involve the isolation and in vivo testing of bioactive compounds

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field