http://http://dspace.unitus.it:80 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. 2013-05-22T06:04:26Z http://hdl.handle.net/2067/1571 Title: Synthesis of a novel ester of hydroxytyrosol and lipoic acid exhibiting an antiproliferative effect on human colon cancer HT-29 cells Authors: Bernini, Roberta; Crisante, Fernanda; Merendino, Nicolò; Molinari, Romina; Soldatelli, Maria Chiara; Velotti, Francesca Abstract: A novel hydroxytyrosol-lipoic acid derivative has been synthesized. Key steps are an esterification reaction between tyrosol and -lipoic acid derivatives and a regioselective aromatic hydroxylation of the monohydroxylated ester performed by 2-iodoxybenzoic acid (IBX) followed by an in situ reduction with sodium dithionite (Na2S2O4). The novel ester exhibited an antiproliferative effect on the human colorectal adenocarcinoma HT-29 cell line significantly more potent than its parent compounds 2009-12-31T23:00:00Z http://hdl.handle.net/2067/2068 Title: Involvement of 5-lipoxygenase in survival of Epstein-Barr virus (EBV)-converted B lymphoma cells Authors: Belfiore, Maria Cristina; Natoni, Alessandro; Barzellotti, Roberta; Merendino, Nicolò; Pessina, Gloria; Gualandi, Giampiero Abstract: Epstein–Barr Virus (EBV) is involved in the progression of lymphomas through still unknown mechanism involving increased resistance to induced apoptosis. We show here that in a set of apoptosis-resistant EBV-converted Burkitt’s lymphoma clones, 5- and 12-lipoxygenases (LOXs) are over-expressed. Further investigations on 5-LOX showed that resistance to apoptosis increases parallely with the expression of 5-lipoxygenase (5-LOX). Inhibitors of 5-LOX: (a) decrease peroxides level, indicating that this enzyme promotes the generation of oxidative stress in EBV+ cells, and (b) potently induce apoptosis in the EBV resistant cell line E2R. 5- and 15-HETE, the products of the 5 and 15-LOXs, respectively, counteract 5-LOX inhibitor induced apoptosis, indicating that products of arachidonate metabolism, rather than peroxides, trigger a signal transduction that is required for survival of the EBV-converted cells. These findings suggest that 5- and, to a lesser extent, other LOXs, that are involved in tumor progression of several cell types, may also participate in lymphomagenesis, especially that EBV-mediated. Description: L'articolo è disponibile sul sito dell'editore http://www.sciencedirect.com 2006-12-31T23:00:00Z http://hdl.handle.net/2067/1581 Title: Synthesis of a novel ester of hydroxytyrosol and lipoic acid exhibiting an antiproliferative effect on human colon cancer HT-29 cells Authors: Bernini, Roberta; Crisante, Fernanda; Merendino, Nicolò; Molinari, Romina; Soldatelli, Maria Chiara; Velotti, Francesca Abstract: A novel hydroxytyrosol-lipoic acid derivative has been synthesized. Key steps are an esterification reaction between tyrosol and cJipoic acid derivatives and a regioselective aromatic hydroxylation ofthe monohydroxylated ester performed by 2-iodoxybenzoic acid (IBX) followed by an in situ reductionw ith sodium dithionite (Na2S2O4T).h e novel estere xhibited an antiproliferative effect on the human colorectal adenocarcinoma HT-29 cell line signifrcantly more potent than its parent compounds. 2009-12-31T23:00:00Z http://hdl.handle.net/2067/2069 Title: Zinc deficiency suppresses the development of oral tolerance in rats Authors: Finamore, Alberto; Roselli, Marianna; Merendino, Nicolò; Nobili, Fabio; Vignolini, Francesco; Mengheri, Elena Abstract: Oral tolerance is a specific immune unresponsiveness to food antigens to prevent hypersensitivity reactions. We investigated whether zinc deficiency affects oral tolerance. Rats were fed a control (C) or zincdeficient (ZD) diet, or pair-fed (PF) to ZD rats for 28 d. Beginning on d 7, rats were administered ovalbumin (OVA) orally to induce tolerance, or PBS 3 times/wk, and were then immunized by OVA injection. The proliferation of mesenteric lymph node (MLN) and spleen lymphocytes after in vitro OVA stimulation and the delayed-type hypersensitivity were higher in OVA-fed ZD than in OVA-fed C rats and not different between OVA- and PBS-fed ZD rats, indicating a suppression of tolerance. Lymphocyte proliferation did not differ between PF and C rats. Expressions of cytokines involved in oral tolerance, i.e., interleukin (IL)-4, IL-10 and transforming growth factor- , were higher in OVA- than in PBS-fed C rats, but not in ZD rats. Apoptosis was higher in OVA- than in PBS-fed C rats but not different between OVA- and PBS-fed ZD rats. Inflammation and ulcerations that were not present in ZD rats on d 7 (ZD7 ) developed in OVA- or PBS-fed ZD rats. Compared with ZD7 rats, tumor necrosis factor- and cytokine-induced neutrophil chemoattractant were higher in OVA- and PBS-fed ZD rats, whereas interferon- increased only in OVA-fed ZD rats. In conclusion, zinc deficiency suppresses oral tolerance through dysregulation of cytokine expression and lack of antigen-specific clonal deletion. We suggest that abrogation of tolerance may lead to development of mucosal inflammation and damage. Description: L'articolo è disponibile sul sito dell'editore http://jn.nutrition.org 2002-12-31T23:00:00Z