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4 Publications visible to you, out of a total of 4
Humudifucol and Bioactive Prenylated Polyphenols from Hops (Humulus lupulus cv. "Cascade")

Abstract (Expand)

Humulus lupulus (hop plant) has long been used in traditional medicine as a sedative and antimicrobial agent. More recently, attention has been devoted to the phytoestrogenic activity of the plant … extracts as well as to the anti-inflammatory and chemopreventive properties of the prenylated chalcones present. In this study, an Italian sample of H. lupulus cv. "Cascade" has been investigated and three new compounds [4-hydroxycolupulone (6), humudifucol (7) and cascadone (8)] have been purified and identified by means of NMR spectroscopy along with four known metabolites. Notably, humudifucol (7) is the first prenylated dimeric phlorotannin discovered in nature. Because structurally related phloroglucinols from natural sources were found previously to inhibit microsomal prostaglandin E2 synthase (mPGES)-1 and 5-lipoxygenase (5-LO), the isolated compounds were evaluated for their bioactivity against these pro-inflammatory target proteins. The prenylated chalcone xanthohumol inhibited both enzymes at low muM concentrations.

Authors: M. Forino, , G. Chianese, L. Santagostini, , C. Weinigel, S. Rummler, G. Fico, , O. Taglialatela-Scafati

Date Published: 27th Feb 2016

Publication Type: Not specified

The hallucinogenic diterpene salvinorin A inhibits leukotriene synthesis in experimental models of inflammation

Abstract (Expand)

Leukotrienes (LTs) are lipid mediators derived from arachidonic acid (AA) involved in a number of autoimmune/inflammatory disorders including asthma, allergic rhinitis and cardiovascular diseases. … Salvinorin A (SA), a diterpene isolated from the hallucinogenic plant Salvia divinorum, is a well-established analgesic compound, but its anti-inflammatory properties are under-researched and its effects on LT production is unknown to date. Here, we studied the possible effect of SA on LT production and verified its actions on experimental models of inflammation in which LTs play a prominent role. Peritoneal macrophages (PM) stimulated by calcium ionophore A23187 were chosen as in vitro system to evaluate the effect of SA on LT production. Zymosan-induced peritonitis in mice and carrageenan-induced pleurisy in rats were selected as LT-related models to evaluate the effect of SA on inflammation as well as on LT biosynthesis. SA inhibited, in a concentration-dependent manner, A23187-induced LTB4 biosynthesis in isolated PM. In zymosan-induced peritonitis, SA inhibited cell infiltration, myeloperoxidase activity, vascular permeability and LTC4 production in the peritoneal cavity without decreasing the production of prostaglandin E2. In carrageenan-induced pleurisy in rats, a more sophisticated model of acute inflammation related to LTs, SA significantly inhibited LTB4 production in the inflammatory exudates, along with reducing the phlogistic process in the lung. In conclusion, SA inhibited LT production and it was effective in experimental models of inflammation in which LTs play a pivotal role. SA might be considered as a lead compound for the development of drugs useful in LTs-related diseases.

Authors: A. Rossi, , F. Tedesco, E. Pagano, G. Guerra, F. Troisi, , F. Roviezzo, J. K. Zjawiony, , A. A. Izzo, R. Capasso

Date Published: 10th Feb 2016

Publication Type: Not specified

Human macrophages differentially produce specific resolvin or leukotriene signals that depend on bacterial pathogenicity.

Abstract (Expand)

Proinflammatory eicosanoids (prostaglandins and leukotrienes) and specialized pro-resolving mediators (SPM) are temporally regulated during infections. Here we show that human macrophage phenotypes … biosynthesize unique lipid mediator signatures when exposed to pathogenic bacteria. E. coli and S. aureus each stimulate predominantly proinflammatory 5-lipoxygenase (LOX) and cyclooxygenase pathways (i.e., leukotriene B4 and prostaglandin E2) in M1 macrophages. These pathogens stimulate M2 macrophages to produce SPMs including resolvin D2 (RvD2), RvD5, and maresin-1. E. coli activates M2 macrophages to translocate 5-LOX and 15-LOX-1 to different subcellular locales in a Ca(2+)-dependent manner. Neither attenuated nor non-pathogenic E. coli mobilize Ca(2+) or activate LOXs, rather these bacteria stimulate prostaglandin production. RvD5 is more potent than leukotriene B4 at enhancing macrophage phagocytosis. These results indicate that M1 and M2 macrophages respond to pathogenic bacteria differently, producing either leukotrienes or resolvins that further distinguish inflammatory or pro-resolving phenotypes.

Authors: O. Werz, J. Gerstmeier, S. Libreros, X. De la Rosa, M. Werner, P. C. Norris, N. Chiang, C. N. Serhan

Date Published: No date defined

Publication Type: Not specified

Algal Oxylipins Mediate the Resistance of Diatoms against Algicidal Bacteria.

Abstract (Expand)

Algicidal bacteria can lyse microalgal blooms and trigger shifts within plankton communities. Resistant algal species can escape lysis, and have the opportunity to dominate the phytoplankton after a … bacterial infection. Despite their important function in ecosystem regulation, little is known about mechanisms of resistance. Here, we show that the diatom Chaetoceros didymus releases eicosanoid oxylipins into the medium, and that the lytic algicidal bacterium, Kordia algicida, induces the production of several wound-activated oxylipins in this resistant diatom. Neither releases nor an induction occurs in the susceptible diatom Skeletonema costatum that is lysed by the bacterium within a few days. Among the upregulated oxylipins, hydroxylated eicosapentaenoic acids (HEPEs) dominate. However, also, resolvins, known lipid mediators in mammals, increase upon exposure of the algae to the algicidal bacteria. The prevailing hydroxylated fatty acid, 15-HEPE, significantly inhibits growth of K. algicida at a concentration of approximately 1 microM. The oxylipin production may represent an independent line of defense of the resistant alga, acting in addition to the previously reported upregulation of proteases.

Authors: N. Meyer, J. Rettner, M. Werner, O. Werz, G. Pohnert

Date Published: No date defined

Publication Type: Not specified

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