Effect of lysed and non-lysed sickle red cells on the activation of NLRP3 inflammasome and LTB4 production by mononuclear cells.

OBJECTIVE AND DESIGN: This study tested the hypothesis that sickle red blood cell (SS-RBC) can induce inflammasome NLRP3 components gene expression in peripheral blood mononuclear cells (PBMCs) as well as interleukin-1ß (IL-1ß) and leukotriene B4 (LTB4) production. Additionally, we investigated the effect of hydroxyurea (HU) treatment in these inflammatory markers. METHODS: PBMCs from healthy donors (AA-PBMC) were challenged with intact and lysed RBCs from SCA patients (SS-RBC) and from healthy volunteers (AA-RBC). NLRP3, IL-1ß, IL-18 and Caspase-1 gene expression levels were assessed by quantitative PCR (qPCR). IL-1ß protein levels and LTB4 were measured by ELISA. RESULTS: We observed that lysed SS-RBC induced the expression of inflammasome NLRP3 components, but this increase was more prominent for CASP1 and IL18 expression levels. Moreover, we observed that intact SS-RBC induced higher production of IL-1ß and LTB4 than lysed SS-RBC. Although SCA patients treated with HU have a reduction in NLRP3 gene expression and LTB4 production, this treatment did not modulate the expression of other inflammasome components or IL-1ß production. CONCLUSIONS: Thus, our data suggest that caspase-1, IL-1ß and IL-18 may contribute to the inflammatory status observed in SCA and that HU treatment may not interfere in this inflammatory pathway.

GC-MS Profile and Enhancement of Antibiotic Activity by the Essential Oil of Ocotea odorífera and Safrole: Inhibition of Staphylococcus aureus Efflux Pumps.

Considering the evidence that essential oils, as well as safrole, could modulate bacterial growth in different resistant strains, this study aims to characterize the phytochemical profile and evaluate the antibacterial and antibiotic-modulating properties of the essential oil Ocotea odorífera (EOOO) and safrole against efflux pump (EP)-carrying strains. The EOOO was extracted by hydrodistillation, and the phytochemical analysis was performed by gas chromatography coupled to mass spectrometry (GC-MS). The antibacterial and antibiotic-modulating activities of the EOOO and safrole against resistant strains of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were analyzed through the broth microdilution method. The EP-inhibiting potential of safrole in association with ethidium bromide or antibiotics was evaluated using the S. aureus 1199B and K2068 strains, which carry genes encoding efflux proteins associated with antibiotic resistance to norfloxacin and ciprofloxacin, respectively. A reduction in the MIC of ethidium bromide or antibiotics was used as a parameter of EP inhibition. The phytochemical analysis identified 16 different compounds in the EOOO including safrole as the principal constituent. While the EOOO and safrole exerted clinically relevant antibacterial effects against S. aureus only, they potentiated the antibacterial activity of norfloxacin against all strains evaluated by our study. The ethidium bromide and antibiotic assays using the strains of S. aureus SA1119B and K2068, as well as molecular docking analysis, indicated that safrole inhibits the NorA and MepA efflux pumps in S. aureus. In conclusion, Ocotea odorifera and safrole presented promising antibacterial and antibiotic-enhancing properties, which should be explored in the development of drugs to combat antibacterial resistance, especially in strains bearing genes encoding efflux proteins.

Antioxidative effect and phytochemical profile of natural products from the fruits of "babaçu" (Orbignia speciose) and "buriti" (Mauritia flexuosa).

Orbignya speciosa and Mauritia flexuosa are two native palm tree species found in Brazil. Their fruits are rich in edible fixed oils, which are used for many purposes in industry, such as in the manufacture of soaps, surfactants and margarines. The aim of this work was to characterize the chemical profiles and antioxidant properties of the methanol extracts obtained from the fruits of O. speciosa and M. flexuosa. The chemical prospection was carried out using specific qualitative tests to evaluate the presence of phenolic compounds (tannins and flavonoids) in the extracts of both species. The antioxidant properties of the extracts were analyzed by the following methods: production of thiobarbituric acid reactive substances (TBARS) from phospholipids, deoxyribose degradation, radical-scavenging activity-DPPH, iron chelation assay and ferric-reducing antioxidant power (FRAP). The methanolic extracts obtained from M. flexuosa and O. speciosa presented significant antioxidant activities, although M. flexuosa presented higher antioxidant activity than O. speciosa. In conclusion, M. flexuosa and O. speciosa are important sources of antioxidant substances that may be useful in the development of new products to prevent diseases associated with oxidative stress.

Effectiveness of Cissampelos sympodialis and its isolated alkaloid warifteine in airway hyperreactivity and lung remodeling in a mouse model of asthma.

BACKGROUND: Cissampelos sympodialis Eichl. (Menispermaceae) is a plant found in Northeastern and Southeast of Brazil and hot water infusion of C. sympodialis root bark is largely used in the indigenous and folk medicine to treat several inflammatory disorders, including asthma. Asthma is a chronic inflammatory allergic disease characterized by airway hyperreactivity (AHR), eosinophil tissue infiltration and lung remodeling. The aim of this study was to evaluate the therapeutic effect of C. sympodialis and its isolated alkaloid warifteine on allergen triggered airway hyperreactivity (AHR) and lung remodeling in murine model of asthma. METHODOLOGY/PRINCIPAL FINDINGS: The oral pre-treatment with C. sympodialis or warifteine inhibited allergen-induced AHR to inhaled methacholine and IL-13 levels in the bronchoalveolar lavage (BAL). In order to investigate the therapeutic potential of C. sympodialis and warifteine, animals were treated 1h after the last ovalbumin (OVA) challenge in sensitized animals. Similarly to the pre-treatment, post-treatment with warifteine was effective to inhibit significantly AHR to inhaled methacholine and to reduce IL-13 levels in the BAL. In addition, oral pre- or post-treatments with C. sympodialis or warifteine reduced OVA-induced eosinophil tissue infiltration, mucus production and subepithelial fibrosis to values similar to nonallergic controls. CONCLUSIONS: Our data show the anti-allergic and immunoregulatory properties of C. sympodialis, acting mostly through the active compound warifteine, to inhibit the airway hyperreactivity and lung remodeling through a mechanism at least partially dependent of IL-13 and eosinophil inhibition. Therefore placing warifteine as an interesting therapeutic candidate in allergic inflammation and corroborating the folk medicine use of C. sympodialis as anti-allergic plant.