-
Giorgio Honsell,
Alois Bonifacio, Marco De Bortoli,
Antonella Penna,
Cecilia Battocchi,
Patrizia Ciminiello,
Carmela Dell 'aversano,
Ernesto Fattorusso,
Silvio Sosa,
Takeshi Yasumoto,
Aurelia Tubaro
[show abstract]
[hide abstract]
ABSTRACT: The harmful dinoflagellate Ostreopsis cf. ovata has been causing toxic events along the Mediterranean coasts and other temperate and tropical areas, with increasing frequency during the last decade. Despite many studies, important biological features of this species are still poorly known. An integrated study, using different microscopy and molecular techniques, Raman microspectroscopy and high resolution liquid chromatography-mass spectrometry (HR LC-MS), was undertaken to elucidate cytological aspects, and identify main metabolites including toxins. The species was genetically identified as O. cf. ovata, Atlantic-Mediterranean clade. The ultrastructural results show unique features of the mucilage network abundantly produced by this species to colonize benthic substrates, with a new role of trichocysts, never described before. The amorphous polysaccharidic component of mucilage appears to derive from pusule fibrous material and mucocysts. In all stages of growth, the cells show an abundant production of lipids. Different developmental stages of chloroplasts are found in the peripheral cytoplasm and in the centre of cell. In vivo Raman microspectroscopy confirms the presence of the carotenoid peridinin in O. cf. ovata, and detects in several specimen the abundant presence of unsaturated lipids structurally related to docosahexaenoic acid. The HR LC-MS analysis reveals that ovatoxin-a is the predominant toxin, together with decreasing amounts of ovatoxin-b, -d/e, -c and putative palytoxin. Toxins concentration on a per cell basis increases from exponential to senescent phase. The results suggest that benthic blooms of this species are probably related to features such as the ability to create a unique mucilaginous sheath covering the sea bottom, associated with the production of potent toxins as palytoxin-like compounds. In this way, O. cf. ovata may be able to rapidly colonize benthic substrates outcompeting other species. Copyright: ß 2013 Honsell et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: The work was supported by the Italian Ministry of Education, University and Research (www.miur.it; PRIN 2007FXSCL2_005) and by Regione Autonoma Friuli-Venezia Giulia, Direzione Risorse Rurali, Agroalimentari e Forestali (www.regione.fvg.it/rafvg/cms/RAFVG/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist.
PLoS ONE 03/2013; · 4.09 Impact Factor
-
Sabrina Boscolo,
Marco Pelin, Marco De Bortoli,
Giampaolo Fontanive,
Alvaro Barreras,
Federico Berti,
Silvio Sosa,
Olivier Chaloin,
Alberto Bianco,
Takeshi Yasumoto,
Maurizio Prato,
Mark Poli,
Aurelia Tubaro
[show abstract]
[hide abstract]
ABSTRACT: Palytoxins are potent marine biotoxins that have recently become endemic to the Mediterranean Sea, and are becoming more frequently associated with seafood. Due to their high toxicity, suitable methods to quantify palytoxins are needed. Thus, we developed an indirect sandwich ELISA for palytoxin and 42-hydroxy-palytoxin. An intra-laboratory study demonstrated sensitivity (limit of detection, LOD=1.1 ng/ml; limit of quantitation, LOQ=2.2 ng/ml), accuracy (bias of 2.1%), repeatability (RSDr=6% and 9% for intra- and inter-assay variability, respectively) and specificity: other common marine toxins (okadaic acid, domoic acid, saxitoxin, brevetoxin-3 and yessotoxin) don't cross-react in this assay. It performed well in three different matrices: observed LOQs were 11.0, 9.6, and 2.4 ng/ml for mussel extracts, algal net samples and seawater, respectively, with good accuracy and precision. The LOQ in seafood is 11 µg palytoxin/kg mussel meat, lower than that of the most common detection technique, LC-MS/MS.
Environmental Science & Technology 01/2013; · 4.80 Impact Factor
-
Giorgio Honsell, Marco De Bortoli,
Sabrina Boscolo,
Carmela Dell'Aversano,
Cecilia Battocchi,
Giampaolo Fontanive,
Antonella Penna,
Federico Berti,
Silvio Sosa,
Takeshi Yasumoto,
Patrizia Ciminiello,
Mark Poli,
Aurelia Tubaro
[show abstract]
[hide abstract]
ABSTRACT: Ostreopsis cf. ovata, a benthic dinoflagellate often blooming along the Mediterranean coasts, has been associated with toxic events ranging from dyspnea to mild dermatitis. In late September 2009, an Ostreopsis cf. ovata bloom occurred in the Gulf of Trieste (Northern Adriatic Sea; Italy), causing pruritus and mild dermatitis in beachgoers. An integrated study was initiated to characterize Ostreopsis cells by light and confocal microscopy, PCR techniques, immunocytochemistry, and high resolution liquid chromatography-mass spectrometry (HR LC-MS). The presence of Ostreopsis cf. ovata of the Atlantic/Mediterranean clade was unambiguously established by morphological and genetic analyses in field samples. Several palytoxin-like compounds (ovatoxin-a,-b,-c,-d,-e) were identified by HR LC-MS, ovatoxin-a being the most abundant (45-64 pg/cell). Surprisingly, no palytoxin was detected. For the first time, monoclonal and polyclonal antipalytoxin antibodies revealed the intracellular cytoplasmic localization of ovatoxins, suggesting their cross-reactivity with these antibodies. Since harmful dinoflagellates do not always produce toxins, the immunocytochemical localization of ovatoxins, although qualitative, can provide an early warning for toxic Ostreopsis cells before their massive diffusion and/or concentration in seafood.
Environmental Science & Technology 08/2011; 45(16):7051-9. · 4.80 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: There is growing evidence that the cannabinoid CB(1) receptor antagonist, rimonabant (SR141716) exerts potential anti-proliferative and anti-inflammatory actions. Here, we have assessed the effects of rimonabant in vitro in murine immortalized keratinocytes and in vivo by assaying the topical anti-inflammatory activity.
Cell viability and death in a keratinocyte cell line (C5N cells) were measured by Trypan blue exclusion assay and cytotoxicity by sulphorhodamine B test. Cell cycle progression was assessed by flow cytometry and the expression of apoptotic and anti-apoptotic markers, cyclins, pathways of signal transduction and CB1 receptor levels were evaluated by Western blot. The topical anti-inflammatory properties of rimonabant were analysed by inhibition of croton oil-induced ear dermatitis in mice.
Rimonabant reduced cell viability and induced apoptosis as shown by the enhanced number of cells in the subG0 phase of the cell cycle, the expression of Bax and reduced levels of Bcl-2 and X-inhibitor of apoptosis protein. In addition, reduced levels of phosphorylated serine/threonine protein kinase Akt and nuclear factor-kappa B were detected associated with regulation of total nuclear factor-kappa B and inhibitor of kappa B-α, phosphorylated inhibitor of kappa B-α, cyclins D1, E and A. In croton oil-induced ear dermatitis, rimonabant significantly reduced oedema and leukocyte infiltrate.
Rimonabant reduced cell viability, inducing cell death in keratinocytes and decreased croton oil-induced ear dermatitis. Our findings suggest a potential application of rimonabant as a topical anti-inflammatory drug. We did not assess the involvement of CB(1) receptors in these effects of rimonabant.
British Journal of Pharmacology 09/2010; 162(1):84-93. · 4.41 Impact Factor
-
Patrizia Ciminiello,
Carmela Dell’Aversano,
Emma Dello Iacovo,
Ernesto Fattorusso,
Martino Forino,
Laura Grauso,
Luciana Tartaglione,
Chiara Florio,
Paola Lorenzon, Marco De Bortoli,
Aurelia Tubaro,
Mark Poli,
Gary Bignami
[show abstract]
[hide abstract]
ABSTRACT: This paper reports on the analysis of the toxin content from Palythoa tuberculosa and Palythoa toxica samples collected off of the Hawaiian coast. Our work, based on in-depth high-resolution liquid chromatography−mass spectrometry analysis along with extensive NMR study, led us to structurally characterize 42-hydroxy-palytoxin, a new palytoxin congener. This toxin and palytoxin itself appeared to be the major components of toxic extract from a P. tuberculosa sample, while 42-hydroxy-palytoxin was proven by far to be the main palytoxin derivative in P. toxica. Functional studies on this new palytoxin-like compound suggest that the new palytoxin analogue and palytoxin itself present similar biological activities.
Chemical Research in Toxicology 11/2009; 22(11). · 3.78 Impact Factor
