Publications by authors named "Alessia Parroni"

12 Publications

  • Page 1 of 1

Oligosaccharides Derived from Tramesan: Their Structure and Activity on Mycotoxin Inhibition in and .

Biomolecules 2021 Feb 8;11(2). Epub 2021 Feb 8.

Department of Life Sciences, University of Trieste, Via Licio Giorgieri 1, Bdg. C11, 34127 Trieste, Italy.

Food and feed safety are of paramount relevance in everyday life. The awareness that different chemicals, e.g., those largely used in agriculture, could present both environmental problems and health hazards, has led to a large limitation of their use. Chemicals were also the main tool in a control of fungal pathogens and their secondary metabolites, mycotoxins. There is a drive to develop more environmentally friendly, "green", approaches to control mycotoxin contamination of foodstuffs. Different mushroom metabolites showed the potential to act as control agents against mycotoxin production. The use of a polysaccharide, Tramesan, extracted from the basidiomycete , for controlling biosynthesis of aflatoxin B1 and ochratoxin A, has been previously discussed. In this study, oligosaccharides obtained from Tramesan were evaluated. The purified exopolysaccharide of was partially hydrolyzed and separated by chromatography into fractions from disaccharides to heptasaccharides. Each fraction was individually tested for mycotoxin inhibition in and . Fragments smaller than seven units showed no significant effect on mycotoxin inhibition; heptasaccharides showed inhibitory activity of up to 90% in both fungi. These results indicated that these oligosaccharides could be used as natural alternatives to crop protection chemicals for controlling these two mycotoxins.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/biom11020243DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7914814PMC
February 2021

The Potential of Plant-Based Bioactive Compounds on Inhibition of Aflatoxin B1 Biosynthesis and Down-regulation of , and Genes.

Antibiotics (Basel) 2020 Oct 23;9(11). Epub 2020 Oct 23.

Department of Environmental Biology, Sapienza University, 00185 Roma, Italy.

The use of plant extracts in pre- and post-harvest disease management of agricultural crops to cope with aflatoxin B1 contamination has shown great promise due to their capability in managing toxins and safe-keeping the quality. We investigated the anti-aflatoxigenic effect of multiple doses of eight plant extracts (, , , , , , , ) on via LC-MS and the down-regulatory effect of them on , and genes involved in the aflatoxin B1 biosynthesis pathway using RT-qPCR analyses. Our results showed that (4 mg/mL), (6 mg/mL) and (2 mg/mL) completely stopped the production of aflatoxin B1, without inducing significant changes in growth. Furthermore, our findings showed a highly significant correlation between the gene expression and the aflatoxin B1 biosynthesis, such that certain doses of the extracts reduced or blocked the expression of the , and and consequently reduced the synthesis of aflatoxin B1. Interestingly, compared to the regulatory gene (), the down-regulation of expression in the structural genes ( and ) was more consistent and correlated with the inhibition of aflatoxin B1 production. Overall, this study reveals the anti-aflatoxigenic mechanisms of the selected plant extracts at the gene expression level and provides evidence for their use in plant and crop protection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/antibiotics9110728DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7690750PMC
October 2020

Phytochemical and biological characterization of Italian "sedano bianco di Sperlonga" Protected Geographical Indication celery ecotype: A multimethodological approach.

Food Chem 2020 Mar 16;309:125649. Epub 2019 Oct 16.

Istituto per i Sistemi Biologici, Laboratorio di Risonanza Magnetica "Annalaura Segre", CNR, 00015 Monterotondo (Rome), Italy. Electronic address:

Celery is a widely used vegetable known for its peculiar sensorial and nutritional properties. Here, the white celery (Apium graveolens L.) "sedano bianco di Sperlonga" PGI ecotype was investigated to obtain the metabolic profile of its edible parts (blade leaves and petioles) also related to quality, freshness and biological properties. A multi-methodological approach, including NMR, MS, HPLC-PDA, GC-MS and spectrophotometric analyses, was proposed to analyse celery extracts. Sugars, polyalcohols, amino acids, organic acids, phenols, sterols, fatty acids, phthalides, chlorophylls, tannins and flavonoids were detected in different concentrations in blade leaf and petiole extracts, indicating celery parts as nutraceutical sources. The presence of some phenols in celery extracts was here reported for the first time. Low contents of biogenic amines and mycotoxins confirmed celery quality and freshness. Regarding the biological properties, ethanolic celery extracts inhibited the oxidative-mediated DNA damage induced by tert-butylhydroperoxide and scavenged DPPH and ABTS radicals.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.foodchem.2019.125649DOI Listing
March 2020

Use of the Secreted Proteome of for Controlling the Cereal Pathogen .

Int J Mol Sci 2019 Aug 26;20(17). Epub 2019 Aug 26.

CREA-DC, via C.G. Bertero 22, 00156 Roma, Italy.

is amongst the most recently discovered pathogens of small grains cereals. is the main producer, in Europe, of T2 and HT-toxins in small grain cereals, albeit often asymptomatic; this makes its control challenging. The European Union (EU) is pushing hard on the use of biocontrol agents to minimize the use of fungicides and pesticides, which are detrimental to the environment and responsible for serious pollution of the soil and superficial water. In line with EU directives (e.g., 128/2009), here we report the use of protein fractions, purified from the culture filtrate of the basidiomycete , for controlling . , a so-called medicinal mushroom which is applied as a co-adjuvant in oncology and other pathologies as a producer of biological response modifiers. In this study, the exo-proteome of proved highly efficient in inhibiting the growth of and the biosynthesis of the T2 toxin. Results are promising for its future use as a sustainable product to control infection in cereals under field conditions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijms20174167DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6747115PMC
August 2019

A multi-methodological approach in the study of Italian PDO "Cornetto di Pontecorvo" red sweet pepper.

Food Chem 2018 Jul 10;255:120-131. Epub 2018 Feb 10.

Dipartimento di Fisiologia e Farmacologia "V. Ersparmer", Sapienza Università di Roma, P.le Aldo Moro 5, 00185 Rome, Italy.

A multi-methodological approach was applied to study red sweet peppers (Capsicum annuum L.) ecotype "Cornetto di Pontecorvo" grown in a greenhouse or in open field. This approach includes morphological analysis, chemical composition determination, and biological activity evaluation of different extracts from pepper fruits. Untargeted analyses, namely NMR spectroscopy and mass spectrometry, allowed the comprehensive pepper metabolite profile of pepper pulp, peel and seeds hydroalcoholic and organic extracts to be determined, showing the presence of sugars, organic acids, amino acids and other secondary metabolites. Targeted analyses, such as HPLC-PDA, HPLC-TLC and spectrophotometric analyses allowed polyphenols, tannins, flavonoids and pigments content to be determined. Samples quality and freshness were verified by the low content of biogenic amines and mycotoxins, as determined using HPLC-FLD and HPLC-MS, respectively. Preliminary biological results demonstrated the ability of the organic extracts to inhibit α-amylase, a key enzyme in the control of glucose metabolism.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.foodchem.2018.02.050DOI Listing
July 2018

Tramesan, a novel polysaccharide from Trametes versicolor. Structural characterization and biological effects.

PLoS One 2017 22;12(8):e0171412. Epub 2017 Aug 22.

Dept Life Sciences, Univ. Trieste, Trieste, Italy.

Mushrooms represent a formidable source of bioactive compounds. Some of these may be considered as biological response modifiers; these include compounds with a specific biological function: antibiotics (e.g. plectasin), immune system stimulator (e,g, lentinan), antitumor agents (e.g. krestin, PSK) and hypolipidemic agents (e.g. lovastatin) inter alia. In this study, we focused on the Chinese medicinal mushroom "yun zhi", Trametes versicolor, traditionally used for (cit.) "replenish essence and qi (vital energy)". Previous studies indicated the potential activity of extracts from culture filtrate of asexual mycelia of T. versicolor in controlling the growth and secondary metabolism (e.g. mycotoxins) of plant pathogenic fungi. The quest of active principles produced by T. versicolor, allowed us characterising an exo-polysaccharide released in its culture filtrate and naming it Tramesan. Herein we evaluate the biological activity of Tramesan in different organisms: plants, mammals and plant pathogenic fungi. We suggest that the bioactivity of Tramesan relies mostly on its ability to act as pro antioxidant molecule regardless the biological system on which it was applied.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0171412PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5567496PMC
October 2017

Molecular mechanisms of the non-coenzyme action of thiamin in brain: biochemical, structural and pathway analysis.

Sci Rep 2015 Jul 27;5:12583. Epub 2015 Jul 27.

1] Faculty of Bioengineering and Bioinformatics of Lomonosov Moscow State University, Leninskije Gory 1, 119992 Moscow, Russian Federation [2] Belozersky Institute of Physicochemical Biology of Lomonosov Moscow State University, Leninskije Gory 1, 119992 Moscow, Russian Federation.

Thiamin (vitamin B1) is a pharmacological agent boosting central metabolism through the action of the coenzyme thiamin diphosphate (ThDP). However, positive effects, including improved cognition, of high thiamin doses in neurodegeneration may be observed without increased ThDP or ThDP-dependent enzymes in brain. Here, we determine protein partners and metabolic pathways where thiamin acts beyond its coenzyme role. Malate dehydrogenase, glutamate dehydrogenase and pyridoxal kinase were identified as abundant proteins binding to thiamin- or thiazolium-modified sorbents. Kinetic studies, supported by structural analysis, revealed allosteric regulation of these proteins by thiamin and/or its derivatives. Thiamin triphosphate and adenylated thiamin triphosphate activate glutamate dehydrogenase. Thiamin and ThDP regulate malate dehydrogenase isoforms and pyridoxal kinase. Thiamin regulation of enzymes related to malate-aspartate shuttle may impact on malate/citrate exchange, responsible for exporting acetyl residues from mitochondria. Indeed, bioinformatic analyses found an association between thiamin- and thiazolium-binding proteins and the term acetylation. Our interdisciplinary study shows that thiamin is not only a coenzyme for acetyl-CoA production, but also an allosteric regulator of acetyl-CoA metabolism including regulatory acetylation of proteins and acetylcholine biosynthesis. Moreover, thiamin action in neurodegeneration may also involve neurodegeneration-related 14-3-3, DJ-1 and β-amyloid precursor proteins identified among the thiamin- and/or thiazolium-binding proteins.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/srep12583DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4515825PMC
July 2015

Screening and in vitro testing of antifolate inhibitors of human cytosolic serine hydroxymethyltransferase.

ChemMedChem 2015 Mar 10;10(3):490-7. Epub 2015 Feb 10.

Department of Biochemical Sciences "A. Rossi Fanelli", Sapienza University of Rome, P.le Aldo Moro 5, Roma 00185 (Italy).

Metabolic reprogramming of tumor cells toward serine catabolism is now recognized as a hallmark of cancer. Serine hydroxymethyltransferase (SHMT), the enzyme providing one-carbon units by converting serine and tetrahydrofolate (H4 PteGlu) to glycine and 5,10-CH2 -H4 PteGlu, therefore represents a target of interest in developing new chemotherapeutic drugs. In this study, 13 folate analogues under clinical evaluation or in therapeutic use were in silico screened against SHMT, ultimately identifying four antifolate agents worthy of closer evaluation. The interaction mode of SHMT with these four antifolate drugs (lometrexol, nolatrexed, raltitrexed, and methotrexate) was assessed. The mechanism of SHMT inhibition by the selected antifolate agents was investigated in vitro using the human cytosolic isozyme. The results of this study showed that lometrexol competitively inhibits SHMT with inhibition constant (Ki ) values in the low micromolar. The binding mode of lometrexol to SHMT was further investigated by molecular docking. These results thus provide insights into the mechanism of action of antifolate drugs and constitute the basis for the rational design of novel and more potent inhibitors of SHMT.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/cmdc.201500028DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5438088PMC
March 2015

On the mechanism of Escherichia coli pyridoxal kinase inhibition by pyridoxal and pyridoxal 5'-phosphate.

Biochim Biophys Acta 2015 Sep 3;1854(9):1160-6. Epub 2015 Feb 3.

Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", "Sapienza" Università di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy. Electronic address:

Pyridoxal 5'-phosphate (PLP), the catalytically active form of vitamin B6, plays a crucial role in several cellular processes. In most organisms, PLP is recycled from nutrients and degraded B6-enzymes in a salvage pathway that involves pyridoxal kinase (PLK), pyridoxine phosphate oxidase and phosphatase activities. Regulation of the salvage pathway is poorly understood. Escherichia coli possesses two distinct pyridoxal kinases, PLK1, which is the focus of the present work, and PLK2. From previous studies dating back to thirty years ago, pyridoxal (PL) was shown to inhibit E. coli PLK1 forming a covalent link with the enzyme. This inhibition was proposed to play a regulative role in vitamin B6 metabolism, although its details had never been clarified. Recently, we have shown that also PLP produced during PLK1 catalytic cycle acts as an inhibitor, forming a Schiff base with Lys229, without being released in the solvent. The question arises as to which is the actual inhibition mechanism by PL and PLP. In the present work, we demonstrated that also PL binds to Lys229 as a Schiff base. However, the isolated covalent PLK1-PL complex is not inactive but, in the presence of ATP, is able to catalyse the single turnover production of PLP, which binds tightly to the enzyme and is ultimately responsible for its inactivation. The inactivation mechanism mediated by Lys229 may play a physiological role in controlling cellular levels of PLP. This article is part of a Special Issue entitled: Cofactor-dependent proteins: evolution, chemical diversity and bio-applications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bbapap.2015.01.013DOI Listing
September 2015

Aflatoxin control in maize by Trametes versicolor.

Toxins (Basel) 2014 Dec 17;6(12):3426-37. Epub 2014 Dec 17.

Environmental Biology Department, Università Sapienza, Roma 00185, Italy.

Aspergillus flavus is a well-known ubiquitous fungus able to contaminate both in pre- and postharvest period different feed and food commodities. During their growth, these fungi can synthesise aflatoxins, secondary metabolites highly hazardous for animal and human health. The requirement of products with low impact on the environment and on human health, able to control aflatoxin production, has increased. In this work the effect of the basidiomycete Trametes versicolor on the aflatoxin production by A. flavus both in vitro and in maize, was investigated. The goal was to propose an environmental loyal tool for a significant control of aflatoxin production, in order to obtain feedstuffs and feed with a high standard of quality and safety to enhance the wellbeing of dairy cows. The presence of T. versicolor, grown on sugar beet pulp, inhibited the production of aflatoxin B1 in maize by A. flavus. Furthermore, treatment of contaminated maize with culture filtrates of T. versicolor containing ligninolytic enzymes, showed a significant reduction of the content of aflatoxin B1.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/toxins6123426DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4280542PMC
December 2014

Inhibition of human pyridoxal kinase by 2-acetyl-4-((1R,2S,3R)-1,2,3,4-tetrahydroxybutyl)imidazole (THI).

J Enzyme Inhib Med Chem 2015 Apr 5;30(2):336-40. Epub 2014 Jun 5.

Pharmaceutical Chemistry I, Pharmaceutical Institute , University of Bonn, Bonn , Germany and.

2-Acetyl-4-((1R,2S,3R)-1,2,3,4-tetrahydroxybutyl)imidazole (THI) is observed as a minor contaminant in caramel food colourings (E 150c). Feeding experiments with rodents have revealed a significant lymphopenic effect that has been linked to the presence of THI in these food colourings. Pyridoxal kinase inhibition by THI has been suggested, but not demonstrated, as a mode of action as it leads to lowered levels of pyridoxal-5'-phosphate, which are known to cause lymphopenia. Recently, THI was also shown to inhibit sphingosine-1-phosphate lyase causing comparable immunosuppressive effects and derivatives of THI are being developed for the treatment of rheumatoid arthritis in humans. Interestingly, sphingosine-1-phosphate lyase activity depends on pyridoxal-5'-phosphate, which in turn is provided by pyridoxal kinase. This report shows that THI does inhibit pyridoxal kinase with competitive and mixed-type non-competitive behaviour towards its two substrates, pyridoxal and ATP, respectively. The corresponding inhibition constants are in the low millimolar range.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3109/14756366.2014.915396DOI Listing
April 2015

Pyridoxal 5'-phosphate is a slow tight binding inhibitor of E. coli pyridoxal kinase.

PLoS One 2012 25;7(7):e41680. Epub 2012 Jul 25.

Department of Medicinal Chemistry, Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University, Richmond, Virginia, United States of America.

Pyridoxal 5'-phosphate (PLP) is a cofactor for dozens of B(6) requiring enzymes. PLP reacts with apo-B(6) enzymes by forming an aldimine linkage with the ε-amino group of an active site lysine residue, thus yielding the catalytically active holo-B(6) enzyme. During protein turnover, the PLP is salvaged by first converting it to pyridoxal by a phosphatase and then back to PLP by pyridoxal kinase. Nonetheless, PLP poses a potential toxicity problem for the cell since its reactive 4'-aldehyde moiety forms covalent adducts with other compounds and non-B(6) proteins containing thiol or amino groups. The regulation of PLP homeostasis in the cell is thus an important, yet unresolved issue. In this report, using site-directed mutagenesis, kinetic, spectroscopic and chromatographic studies we show that pyridoxal kinase from E. coli forms a complex with the product PLP to form an inactive enzyme complex. Evidence is presented that, in the inhibited complex, PLP has formed an aldimine bond with an active site lysine residue during catalytic turnover. The rate of dissociation of PLP from the complex is very slow, being only partially released after a 2-hour incubation with PLP phosphatase. Interestingly, the inactive pyridoxal kinase•PLP complex can be partially reactivated by transferring the tightly bound PLP to an apo-B(6) enzyme. These results open new perspectives on the mechanism of regulation and role of pyridoxal kinase in the Escherichia coli cell.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0041680PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3404986PMC
April 2013