Plants and their constituents have been used to treat diverse ailments since time immemorial. Many plants are used in diverse external and internal formulations (infusions, alcoholic extracts, essential oils (EOs), etc.) in the treatment of inflammation-associated diseases, such as those affecting the respiratory tract or causing gastrointestinal or joint problems, among others. To support the traditional uses of plant extracts, EOs have been assessed for their alleged anti-inflammatory properties. However, the effect of EOs on the release of cytokines and chemokines has been much less reported. Considering their traditional use and commercial relevance in Portugal and Angola, this study evaluated the effect of EOs on the in vitro inhibition of the cytokine tumor necrosis factor-α (TNF-α) and the chemokine (C-C motif) ligand 2 (CCL2) by lipopolysaccharide (LPS)-stimulated human acute monocytic leukemia cells (THP-1 cells). Twenty EOs extracted from eighteen species from seven families, namely from Amaranthaceae (Dysphania ambrosioides), Apiaceae (Foeniculum vulgare), Asteraceae (Brachylaena huillensis, Solidago virgaurea), Euphorbiaceae (Spirostachys africana), Lamiaceae (Lavandula luisieri, Mentha cervina, Origanum majorana, Satureja montana, Thymbra capitata, Thymus mastichina, Thymus vulgaris, Thymus zygis subsp. zygis), Myrtaceae (Eucalyptus globulus subsp. maidenii, Eucalyptus radiata, Eucalyptus viminalis) and Pinaceae (Pinus pinaster) were assayed for the release of CCL2 and TNF-α by LPS-stimulated THP-1 cells. B. huillensis, S. africana, S. montana, Th. mastichina and Th. vulgaris EOs showed toxicity to THP-1 cells, at the lowest concentration tested (10 μg/mL), using the tetrazolium dye assay. The most active EOs in reducing TNF-α release by LPS-stimulated THP-1 cells were those of T. capitata (51% inhibition at 20 μg/mL) and L. luisieri (15–23% inhibition at 30 μg/mL and 78–83% inhibition at 90 μg/mL). L. luisieri EO induced a concentration-dependent inhibition of CCL2 release by LPS‑stimulated THP-1 cells (23%, 54% and 82% inhibition at 10, 30 and 90 μg/mL, respectively). These EOs are potentially useful in the management of inflammatory diseases mediated by CCL2 and TNF‑α, such as atherosclerosis and arthritis.

In Portugal, beekeeping activity has a significant weight among livestock production. The antimicrobial activities of Portuguese honeys have been reported, but the anti-biofilm formation and anti-virulence abilities have not been investigated. The main goal of this work was to study the impact of three monofloral honeys (citrus, lavender and strawberry tree) honeys on adherence of Staphylococcus aureus, methicillin-resistant S. aureus (MRSA) and Pseudomonas aeruginosa, as well as the influence of the same honeys on virulence using Galleria mellonella as a model. In addition, the general physico-chemical characterization of these honeys and the microbial quality were also performed. The anti-inflammatory activity was also estimated by analyzing the activity of the enzymes hyaluronidase and lipoxygenase. The tested honeys complied with European legislation and no microbial contamination was observed. Of all the honeys at 12.5 and 25%, w/v the citrus honey caused the highest inhibitory activity against P. aeruginosa. Strawberry tree honey at 25% w/v was able to significantly inhibit the MRSA strains. Anti-biofilm formation and anti-inflammatory activities were observed. The different honeys impaired the virulence of S. aureus and MRSA strains. The Portuguese honeys were capable of combating the tested bacterial pathogens not only by inhibiting their growth but also by affecting important pathogenicity properties, such as adherence and virulence. Propiedades antibacterianas, anti-biofilm, anti-inflamatorias y de inhibició n de la virulencia de mieles portuguesas En Portugal, la actividad apícola tiene un peso significativo entre la producció n ganadera. Las actividades antimicrobianas de las mieles portuguesas han sido reportadas, pero la capacidad de formació n antibiofilm y la habilidad anti-virulencia no se han investigado. El objetivo principal de este trabajo fue estudiar el impacto de tres mieles monoflorales (cítricos, lavanda y madroño) en la adhesió n de Staphylococcus aureus, S. aureus resistente a la meticilina (SARM) y Pseudomonas aeruginosa, así como la influencia de la mismas mieles sobre la virulencia utilizando Galleria mellonella como modelo. Además, también se llevaron a cabo la caracterizació n físico-química general de estas mieles y la calidad microbiana. La actividad anti-inflamatoria también se estimó mediante el análisis de la actividad de la hialuronidasa y enzimas lipoxigenasa. Se observó que las mieles analizadas cumplían con la legislació n europea y que no había contaminació n microbiana. De todas las mieles al 12.5 y 25%, p/v, la miel de cítricos causó la mayor actividad inhibidora frente a P. aeruginosa. La miel de madroño al 25% p/v fue capaz de inhibir significativamente las cepas de SARM. Se observó actividad formació n anti-biofilm y anti-inflamatoria. Los diferentes tipos de miel deterioraron la virulencia de las cepas de S. aureus y SARM. Las mieles portuguesas fueron capaces de combatir los pató genos bacterianos ensayados no só lo mediante la inhibició n de su crecimiento, sino ...