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Propolis and its constituent caffeic acid suppress LPS-stimulated pro-inflammatory response by blocking NF-κB and MAPK activation in macrophages, Journal of Ethnopharmacology, http://dx.doi.org/ 10. 1016/j.jep.2013.06.004 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. AbstractEthnopharmacological relevance: Propolis is a bee product with numerous biological and pharmacological properties, such as immunomodulatory and anti-inflammatory activities.It has been used in folk medicine as a healthy drink and in food to improve health and prevent inflammatory diseases. However, little is known about its mechanism of action.Thus, the goal of this study was to verify the antioxidant activity and to explore the antiinflammatory properties of propolis by addressing its intracellular mechanism of action.Caffeic acid was investigated as a possible compound responsible for propolis action. Materials and Methods:The antioxidant properties of propolis and caffeic acid were evaluated by using the 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH) scavenging method. To analyze the anti-inflammatory activity, Raw 264.7 macrophages were treated with different concentrations of propolis or caffeic acid, and nitric oxide (NO) production, a strong pro-inflammatory mediator, was evaluated by the Griess reaction. The concentrations of propolis and caffeic acid that inhibited NO production were evaluated on intracellular signaling pathways triggered during inflammation, namely p38 mitogenactivated protein kinase (MAPK), c-jun NH 2 -terminal kinase (JNK1/2), the transcription nuclear factor (NF)-NB and extracellular signal-regulated kinase (ERK1/2), through Western blot using specific antibodies. A possible effect of propolis on the cytotoxicity of hepatocytes was also evaluated, since this product can be used in human diets.Results: Caffeic acid showed a higher antioxidant activity than propolis extract. Propolis and caffeic acid inhibited NO production in macrophages, at concentrations without cytotoxicity. Furthermore, both propolis and caffeic acid suppressed LPS-induced signaling pathways, namely p38 MAPK, JNK1/2 and NF-NB. ERK1/2 was not affected by propolis extract and caffeic acid. In addition, propolis and caffeic acid did not induce hepatotoxicity at concentrations with strong anti-inflammatory potential. Conclusions:Propolis exerted an antioxidant and anti-inflammatory action and caffeic acid may be involved in its inhibitory effects on NO production and intracellular signaling cascades, suggesting its use as a natural source of safe anti-inflammatory drugs.

Cartilage matrix homeostasis involves a dynamic balance between numerous signals that modulate chondrocyte functions. This study aimed at elucidating the role of the extracellular glucose concentration in modulating anabolic and catabolic gene expression in normal and osteoarthritic (OA) human chondrocytes and its ability to modify the gene expression responses induced by pro-anabolic stimuli, namely Transforming Growth Factor-b (TGF). For this, we analyzed by real time RT-PCR the expression of articular cartilage matrix-specific and nonspecific genes, namely collagen types II and I, respectively. The expression of the matrix metalloproteinases (MMPs)-1 and -13, which plays a major role in cartilage degradation in arthritic conditions, and of their tissue inhibitors (TIMP) was also measured. The results showed that exposure to high glucose (30 mM) increased the mRNA levels of both MMPs in OA chondrocytes, whereas in normal ones only MMP-1 increased. Collagen II mRNA was similarly increased in normal and OA chondrocytes, but the increase lasted longer in the later. Exposure to high glucose for 24 h prevented TGF-induced downregulation of MMP-13 gene expression in normal and OA chondrocytes, while the inhibitory effect of TGF on MMP-1 expression was only partially reduced. Other responses were not significantly modified. In conclusion, exposure of human chondrocytes to high glucose, as occurs in vivo in diabetes mellitus patients and in vitro for the production of engineered cartilage, favors the chondrocyte catabolic program. This may promote articular cartilage degradation, facilitating OA development and/or progression, as well as compromise the quality and consequent in vivo efficacy of tissue engineered cartilage. J. Cell. Biochem. 112: 2813Biochem. 112: -2824Biochem. 112: , 2011. ß 2011 Wiley-Liss, Inc. KEY WORDS: COLLAGEN; GENE EXPRESSION; GLUCOSE; HUMAN CHONDROCYTE; MMP; OSTEOARTHRITIS; TIMPA rticular cartilage is a specialized connective tissue that supports and distributes loads and ensures a near-frictionless motion in joints. These unique properties are due to the structural organization of the main macromolecules that compose the cartilage extracellular matrix, namely collagens and proteoglycans. Chondrocytes, the only cell type present in articular cartilage, are embedded in the extracellular matrix and are responsible for maintaining its homeostasis by ensuring the synthesis and turnover of its components [Martel-Pelletier et al., 2008;Goldring and Marcu, 2009].Cartilage matrix homeostasis involves a dynamic balance between a variety of signals that modulate chondrocyte functions, namely mechanical forces, cytokines and growth factors and cellmatrix interactions, some favoring an anabolic program and others stimulating catabolic responses. Aging and mechanical stress of joints are major risk factors for osteoarthritis (OA), but growing evidence indicates that metabolic factors play an important role in disease development and progression. For instance, a significant positive correlation wa...

Please cite this article as: Francisco, V., Figueirinha, A., Neves, B.M., García-Rodríguez, C., Lopes, M.C., Cruz, M.T., Batista, M.T., Cymbopogon citratus as source of new and safe anti-inflammatory drugs: bio-guided assay using lipopolysaccharide-stimulated macrophages, Journal of Ethnopharmacology (2010Ethnopharmacology ( ), doi:10.1016Ethnopharmacology ( /j.jep.2010 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Page 1 of 30A c c e p t e d M a n u s c r i p t 1 Graphical abstractIn this report it was demonstrated that a lipid-and essential oil-free infusion of Cymbopogon citratus leaves (Cy), as well its polyphenols, have anti-inflammatory properties through inhibition of proinflammatory signaling pathways and nitric oxide production in lipopolysaccharide-stimulated macrophages. These evidences support the use of Cymbopogon citratus in traditional medicine and indicate that it could be a natural source of new and safe anti-inflammatory drugs. TitleCymbopogon citratus as source of new and safe anti-inflammatory drugs: bio-guided assay using lipopolysaccharide-stimulated macrophages Aim of the study: The aim of this study is to explore the anti-inflammatory properties of Cymbopogon citratus leaves and their polyphenol-rich fractions (PFs), as well its mechanism of action in murine macrophages. Materials and Methods:A lipid-and essential oil-free infusion of Cy leaves was prepared (Cy extract) and fractionated by column chromatography. Anti-inflammatory properties of Cy extract (1.115 mg/ml) and its PFs, namely phenolic acids (530 µg/ml), flavonoids (97.5 µg/ml) and tannins (78 µg/ml), were investigated using lipopolysaccharide (LPS)-stimulated Raw 264.7 macrophages as in vitro model. As inflammatory parameters, nitric oxide (NO) production was evaluated by Griess reaction, as well as effects on cyclooxygenase (COX-2), inducible NO synthase (iNOS) expression and on intracellular signaling pathways activation, which were analyzed by Western blot using specific antibodies. Page 3 of 30A c c e p t e d M a n u s c r i p t Conclusions: Our data provide evidence that support the usage of Cymbopogon citratus leaves extract in traditional medicine, and suggest that Cy, in particular its polyphenolic compounds, could constitute a natural source of a new and safe anti-inflammatory drugs.

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Human chondrocytes express functional InsR that respond to physiologic insulin concentrations. The InsR seems to be more abundant in normal than in OA chondrocytes, but these still respond to physiologic insulin concentrations, although some responses are impaired while others appear fully activated. Understanding the mechanisms that regulate the expression and function of the InsR in normal and OA chondrocytes can disclose new targets for the development of innovative therapies for OA.

Extensive research within the last two decades revealed that most chronic illnesses, including cancer, neurological, autoimmune and cardiovascular diseases are mediated through chronic inflammation. Thus, suppressing chronic inflammation has the potential to delay, prevent, and treat those diseases. However, side effects and high costs of current anti-inflammatory drugs force the development of new drugs. Natural products represent an important source of new bioactive compounds. Among them, phenolic compounds, which are widely distributed in plants, have been described as having many therapeutic effects. Several reviews have addressed the anti-inflammatory activity of phenols, attributing their properties not only to the antioxidant capacity, but also to inflammatory mediators' modulation, namely cytokines and pro-inflammatory proteins, such as inducible nitric oxide synthase and cyclooxygenase-2. Signal transduction pathways precede changes in inflammatory mediators' expression. However, only a restricted number of studies have addressed the effect of phenols on a specific signal transduction pathway. The present review attempts to summarize and highlight a broad range of inflammation-associated signaling pathways modulated by phenols namely: nuclear factor (NF)-κB, activator protein (AP)-1, peroxisome proliferator-activated receptor (PPAR) and nuclear factor erythroid 2-related factor 2 (Nrf2) transcription factors; mitogen-activated protein kinases (MAPKs); protein tyrosine kinases (PTKs); tyrosine phosphatidylinositol 3-kinase (PI3K)/Akt and ubiquitin-proteasome system. As a consequence of phenols effect on signaling pathways, described above, their action on inflammatory mediators' production is mentioned. Finally, it is established that the structure-activity relationships of phenolic compounds are a valuable information source on the development of new anti-inflammatory drugs from natural products.