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Background and purpose:Avarol is a marine sesquiterpenoid hydroquinone with anti-inflammatory and antipsoriatic properties. The aim of this study was to evaluate the in vitro and in vivo pharmacological behaviour of the derivative avarol-3′-thiosalicylate (TA) on some inflammatory parameters related to the pathogenesis of psoriasis.Experimental approach:Human neutrophils and monocytes as well as the human keratinocyte cell line HaCaT were used to study the effect of TA on oxidative stress, the arachidonic acid pathway, tumour necrosis factor-α (TNF-α) release and nuclear factor-κB (NF-κB) activation. All these parameters were also determined in vivo using the zymosan induced mouse air pouch model and the 12-O-tetradecanoylphorbol-13-acetate (TPA) induced mouse epidermal hyperplasia model.Key results:TA showed antioxidant properties in human neutrophils and in the hypoxanthine/xanthine oxidase assay. This compound reduced, in a concentration-dependent manner, leukotriene B4, prostaglandin E2 and TNF-α production in activated leukocytes. Oral and intrapouch administration of TA in the mouse air pouch model produced a dose-dependent reduction of all these inflammatory mediators. TA also inhibited secretory phospholipase A2 activity and NF-κB DNA-binding in HaCaT keratinocytes. In TPA-induced mouse epidermal hyperplasia, topical administration of TA reduced oedema, leukocyte infiltration, eicosanoid levels and TNF-α in skin. In addition, interleukin (IL)-1β and IL-2 production were also inhibited. Finally, TA was also capable of suppressing NF-κB nuclear translocation in vivo.Conclusions and implications:TA inhibited several key biomarkers up-regulated in the inflammatory response of psoriatic skin and this compound could be a promising antipsoriatic agent.British Journal of Pharmacology (2007) 152, 353–365; doi:10.1038/sj.bjp.0707394; published online 16 July 2007 [ABSTRACT FROM AUTHOR]

Presents case reports of allergy to mammalian meats. Symptomatology; Indications for skin prick testing; Quantification of specific immunoglobulin E antibodies.

Objective: Hyperplasia of fibroblast-like synoviocytes (FLS) contributes to chronic inflammation and joint destruction in rheumatoid arthritis (RA). FLICE-inhibitory protein (FLIP) is an antiapoptotic protein that might prevent apoptotic elimination of FLS in response to death ligands such as tumor necrosis factor alpha (TNFalpha) or Fas ligand, which are present in RA synovium. Previous studies on FLIP expression by osteoarthritis (OA) and RA FLS have shown variable results, and the specific role of FLIP as an apoptosis inhibitor in these cells remains unclear. We undertook this study to investigate the expression and antiapoptotic function of FLIP in FLS., Methods: We studied the expression of FLIP by immunohistochemistry and immunoblotting in synovial tissues or cultured FLS from RA and OA patients. FLS apoptosis was induced by an agonistic anti-Fas monoclonal antibody and FLS were then quantified. We studied the effects of cycloheximide (CHX), TNFalpha, and FLIP antisense oligonucleotide on FLIP expression and FLS apoptotic susceptibility., Results: FLIP(L) was the isoform mainly expressed in lining synoviocytes and cultured FLS. Synovial tissues and cultured FLS from OA and RA tissues displayed similar patterns and levels of expression of FLIP. Fas-induced apoptosis was variable in different FLS lines, but differences between OA and RA groups were not detected. TNFalpha induced increases in FLIP(L) and FLIP(S) expression and protected RA FLS from apoptosis, while CHX induced the opposite effects. Down-regulation of FLIP by antisense oligonucleotide strongly sensitized RA FLS to Fas-mediated apoptosis., Conclusion: Apoptosis susceptibility and FLIP expression are similar in OA and RA FLS. Down-regulation of FLIP sensitizes RA FLS to Fas-mediated apoptosis and may be a valuable tool for targeting RA FLS hyperplasia.