Hyperbaric oxygenation applied before or after mild or hard stress: effects on the redox state in the muscle tissue.

The mechanism is unclear for the reported protective effect of hyperbaric oxygen preconditioning against oxidative stress in tissues, and the distinct effects of hyperbaric oxygen applied after stress. The trained mice were divided into three groups: the control, hyperbaric oxygenation preconditioning, and hyperbaric oxygenation applied after mild (fasting) or hard (prolonged exercise) stress. After preconditioning, we observed a decrease in basal levels of nitric oxide, tetrahydrobiopterin, and catalase despite the drastic increase in inducible and endothelial nitric oxide synthases. Moreover, the basal levels of glutathione, related enzymes, and nitrosative stress only increased in the preconditioning group. The control and preconditioning groups showed a similar mild stress response of the endothelial and neuronal nitric oxide synthases. At the same time, the activity of all nitric oxide synthase, glutathione (GSH) in muscle, declined in the experimental groups but increased in control during hard stress. The results suggested that hyperbaric oxygen preconditioning provoked uncoupling of nitric oxide synthases and the elevated levels of GSH in muscle during this study, while hyperbaric oxygen applied after stress showed a lower level of GSH but higher recovery post-exercise levels in the majority of antioxidant enzymes. We discuss the possible mechanisms of the redox response and the role of the nitric oxide in this process.

Selection of a GPER1 Ligand via Ligand-based Virtual Screening Coupled to Molecular Dynamics Simulations and Its Anti-proliferative Effects on Breast Cancer Cells.

BACKGROUND: Recent reports have demonstrated the role of the G Protein-Coupled Estrogen Receptor 1 (GPER1) on the proliferation of breast cancer. The coupling of GPER1 to estrogen triggers cellular signaling pathways related to cell proliferation. OBJECTIVE: Develop new therapeutic strategies against breast cancer. METHOD: We performed in silico studies to explore the binding mechanism of a set of G15 /G1 analogue compounds. We included a carboxyl group instead of the acetyl group from G1 to form amides with several moieties to increase affinity on GPER1. The designed ligands were submitted to ligand-based and structure-based virtual screening to get insights into the binding mechanism of the best designed compound and phenol red on GPER1. RESULTS: According to the in silico studies, the best molecule was named G1-PABA ((3aS,4R,9bR)-4-(6- bromobenzo[d][1,3]dioxol-5-yl)-3a,4,5,9b-tetrahydro-3H-cyclopenta[c]quinoline-8-carboxylic acid). It was synthesized and assayed in vitro in breast cancer (MCF-7 and MDA-MB-231) and normal (MCF-10A) cell lines. Experimental studies showed that the target compound was able to decrease cell proliferation, IC50 values of 15.93 µM, 52.92 µM and 32.45 µM in the MCF-7, MDA-MB-231 and MCF-10A cell lines, respectively, after 72 h of treatment. The compound showed better IC50 values without phenol red, suggesting that phenol red interfere with the G1-PABA action at GPER1, as observed through in silico studies, which is present in MCF-7 cells according to PCR studies and explains the cell proliferation effects. CONCLUSION: Concentration-dependent inhibition of cell proliferation occurred with G1-PABA in the assayed cell lines and could be due to its action on GPER1.

Identification of Ligustrum lucidum pollen allergens using a proteomics approach.

BACKGROUND: Ligustrum spp. are members of the Oleaceae family, one of the most prominent allergic families worldwide. The genus Ligustrum contains approximately fifty species, including Ligustrum lucidum, which have been widely cultivated as ornamental plants, and its pollen is a source of inhalant allergens associated with respiratory allergic diseases. Little is known about the presence of allergenic proteins in L. lucidum. METHODS: The L. lucidum pollen proteins were extracted by a modified phenolic extraction method. A pool of four sera from mono sensitive patients was analyzed by 2DE immunoblotting and mass spectrometric analysis was performed on 6 immunoreactive protein spots. RESULTS: SDS-PAGE of L. lucidum pollen extract revealed proteins in ranges of 15-150 kDa. The 2DE gel profile of the L. lucidum pollen protein extract showed approximately 180 spots, and the 2DE immunoblots obtained using sera from Ligustrum monosensitive patients as the source of IgE antibodies revealed six allergen protein spots, corresponding to Profilin, Enolase, Fra e 9.01 (ß-1,3-glucanase), Pollen-specific Polygalacturonases, Alanine aminotransferase, and two ATP synthase beta subunits. CONCLUSION: We report for the first time the identification of IgE-reactive proteins from L. lucidum.