BackgroundCeliac Disease (CD) is both a frequent disease (1∶100) and an interesting model of a disease induced by food. It consists in an immunogenic reaction to wheat gluten and glutenins that has been found to arise in a specific genetic background; however, this reaction is still only partially understood. Activation of innate immunity by gliadin peptides is an important component of the early events of the disease. In particular the so-called “toxic” A-gliadin peptide P31-43 induces several pleiotropic effects including Epidermal Growth Factor Receptor (EGFR)-dependent actin remodelling and proliferation in cultured cell lines and in enterocytes from CD patients. These effects are mediated by delayed EGFR degradation and prolonged EGFR activation in endocytic vesicles. In the present study we investigated the effects of gliadin peptides on the trafficking and maturation of endocytic vesicles.Methods/Principal FindingsBoth P31-43 and the control P57-68 peptide labelled with fluorochromes were found to enter CaCo-2 cells and interact with the endocytic compartment in pulse and chase, time-lapse, experiments. P31-43 was localised to vesicles carrying early endocytic markers at time points when P57-68-carrying vesicles mature into late endosomes. In time-lapse experiments the trafficking of P31-43-labelled vesicles was delayed, regardless of the cargo they were carrying. Furthermore in celiac enterocytes, from cultured duodenal biopsies, P31-43 trafficking is delayed in early endocytic vesicles. A sequence similarity search revealed that P31-43 is strikingly similar to Hrs, a key molecule regulating endocytic maturation. A-gliadin peptide P31-43 interfered with Hrs correct localisation to early endosomes as revealed by western blot and immunofluorescence microscopy.ConclusionsP31-43 and P57-68 enter cells by endocytosis. Only P31-43 localises at the endocytic membranes and delays vesicle trafficking by interfering with Hrs-mediated maturation to late endosomes in cells and intestinal biopsies. Consequently, in P31-43-treated cells, Receptor Tyrosin Kinase (RTK) activation is extended. This finding may explain the role played by gliadin peptides in inducing proliferation and other effects in enterocytes from CD biopsies.

The carcinogenic activity of chromium appears to be due to its direct interaction with cellular targets and not to nonspecific solid-state carcinogenesis. Chromium was evaluated at 2 valences, Cr+3 (as CrC13) and Cr+6 (as K2Cr2O7), for its toxicity, transforming activity, and ability to induce chromosomal aberrations in tertiary cultures of mouse fetal cells. The ID50 (dose for 50 percent inhibition of cell growth) of Cr+3 was approximately 4 times greater than that of Cr+6 after 96 h of exposure, and about 29 times greater than that of Cr+6 after 1 h of exposure. At equitoxic concentrations, both chromium valences induced the same degree of morphologic changes and alterations of growth behavior, but Cr+6 produced more chromosomal aberrations. Using autoradiography in an established cloned line of mouse cells, unscheduled DNA synthesis was observed in cells previously exposed to Cr+6 but not in cells previously exposed to Cr+3.

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Introduction Cinnamic acids are a class of compounds based on phenyl propanoid backbone (C6‐C3) isolated from plants and microorganisms, exhibiting interesting biological activities. Objective To characterise cinnamic acids through the phytochemical study of welsh onion, Allium fistulosum, and to evaluate their antibacterial and cytotoxic properties. Material and methods The phytochemical study of A. fistulosum was performed through chromatographic techniques, including reversed phase medium‐pressure liquid chromatography (MPLC) and high‐pressure liquid chromatography (HPLC). Preliminary analysis of crude chromatographic fractions from the organic extracts was carried out by proton nuclear magnetic resonance (1H‐NMR) in order to prioritise the study of those having phenyl propanoid skeleton. The structural identification of the isolated compounds was performed through analysis of spectroscopic data, mainly one‐dimensional (1D) and two‐dimensional (2D) NMR. The antibacterial activity was assessed against gram negative (Escherichia coli) and gram positive (Staphylococcus aureus) bacteria while the cytotoxic property was evaluated on breast cancer cell line (MCF‐7). Results The 1H‐NMR study of crude fractions and application of a straightforward method to purify the phenyl propanoid compounds by reversed phase MPLC and HPLC, allowed the effortless isolation of several cinnamic acids, including two new rare phenolic imidates (1 and 2). The use of an entirely NMR approach for structural elucidation of the isolated metabolites allowed the isolated material to be kept for further pharmacological tests. Conclusion These results corroborate the importance of the use of 1D and 2D NMR to the identification of new phenyl propanoids, potential lead compounds against bacteria and cancer cells.

An extensive phytochemical analysis of the polar extracts from bulbs of Welsh onion L. led to the isolation of nine saponins, four of them, named fistulosaponins G (), H (), I (), and J (), have never been reported previously. Fistulosaponins G and I were isolated as a couple of isomers in equilibrium. On the basis of 2D NMR and mass spectrometry data, the structure of the novel compounds were elucidated as (25)-26-[(-D-glucopyranosyl)oxy]-3,22-dihydroxyfurost-5-en-1-yl O--L-rhamnopyranosyl-(1 → 4)-O--L-rhamnopyranosyl-(1 → 4)--D-glucopyranoside () with its 22 epimer (), (25)-26-[(-D-glucopyranosyl)oxy]-3-hydroxyfurost-5,20-dien-1-yl O--L-rhamnopyranosyl-(1 → 4)-O--L-rhamnopyranosyl-(1 → 4)--D-glucopyranoside (), (25)-26-[(-D-glucopyranosyl)oxy]-3,22-dihydroxyfurost-5-en-1-yl O--L-rhamnopyranosyl-(1 → 4)--D-glucopyranoside () with its 22 epimer (), and (25)-26-[(-D-glucopyranosyl)oxy]-3-hydroxyfurost-5,20-dien-1-yl O--L-rhamnopyranosyl-(1 → 4)--D-glucopyranoside (). This is the first report of furostanol saponins in bulbs. In addition, data on the antibacterial tests of the isolated saponins against and are reported.

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