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1.
Environ Sci Pollut Res Int ; 27(16): 20125-20135, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32239408

RESUMO

Nanoparticles are widely studied for applications in medical science. In recent years, they have been developed for agronomical purposes to target microbial pest such as bacteria, fungi, and viruses. Nanoparticles are also proposed to limit the use of pesticides, whose abuse is causing environmental impact and human health concerns. In this study, nanoparticles were obtained by using poly-(ε-caprolactone), a polyester chosen for its biocompatibility and biodegradability properties. Poly-(ε-caprolactone) nanoparticles were formulated by using poly(vinyl alcohol) or Pluronic® F127 as non-ionic surfactants, and then loaded with benzophenone or valerophenone thiosemicarbazone, two compounds that inhibit aflatoxin production by Aspergillus flavus. The different types of nanoparticles were compared in terms of size, polydispersity index, morphology, and drug loading capacity. Finally, their effects were investigated on growth, development, and aflatoxin production in the aflatoxigenic species Aspergillus flavus, a ubiquitous contaminant of maize, cereal crops, and derived commodities. Aflatoxin production was inhibited to various extents, but the best inhibitory effect was obtained with respect to sclerotia production that was most effectively suppressed by both benzophenone and valerophenone thiosemicarbazone-loaded nanoparticles. These data support the idea that it is possible to use such nanoparticles as an alternate to pesticides for the control of mycotoxigenic sclerotia-forming fungi.


Assuntos
Aflatoxinas/análise , Tiossemicarbazonas , Aspergillus flavus , Produtos Agrícolas , Zea mays
2.
J Agric Food Chem ; 67(39): 10947-10953, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31498626

RESUMO

Aflatoxins are secondary fungal metabolites that can contaminate feed and food. They are a cause of growing concern worldwide, because they are potent carcinogenic agents. Thiosemicarbazones are molecules that possess interesting antiaflatoxigenic properties, but in order to use them as crop-protective agents, their cytotoxic and genotoxic profiles must first be assessed. In this paper, a group of thiosemicarbazones and a copper complex are reported as compounds able to antagonize aflatoxin biosynthesis, fungal growth, and sclerotia biogenesis in Aspergillus flavus. The two most interesting thiosemicarbazones found were noncytotoxic on several cell lines (CRL1790, Hs27, HFL1, and U937), and therefore, they were submitted to additional analysis of mutagenicity and genotoxicity on bacteria, plants, and human cells. No mutagenic activity was observed in bacteria, whereas genotoxic activity was revealed by the Alkaline Comet Assay on U937 cells and by the test of chromosomal aberrations in Allium cepa.


Assuntos
Aflatoxinas/metabolismo , Antifúngicos/farmacologia , Aspergillus flavus/efeitos dos fármacos , Produtos Agrícolas/microbiologia , Dano ao DNA/efeitos dos fármacos , Doenças das Plantas/prevenção & controle , Tiossemicarbazonas/farmacologia , Aspergillus flavus/genética , Aspergillus flavus/crescimento & desenvolvimento , Aspergillus flavus/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Humanos , Doenças das Plantas/microbiologia
3.
Molecules ; 24(16)2019 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-31426298

RESUMO

Amongst the various approaches to contain aflatoxin contamination of feed and food commodities, the use of inhibitors of fungal growth and/or toxin biosynthesis is showing great promise for the implementation or the replacement of conventional pesticide-based strategies. Several inhibition mechanisms were found taking place at different levels in the biology of the aflatoxin-producing fungal species such as Aspergillus flavus: compounds that influence aflatoxin production may block the biosynthetic pathway through the direct control of genes belonging to the aflatoxin gene cluster, or interfere with one or more of the several steps involved in the aflatoxin metabolism upstream. Recent findings pointed to mitochondrial functionality as one of the potential targets of some aflatoxin inhibitors. Additionally, we have recently reported that the effect of a compound belonging to the class of thiosemicarbazones might be related to the energy generation/carbon flow and redox homeostasis control by the fungal cell. Here, we report our investigation about a putative molecular target of the 3-isopropylbenzaldehyde thiosemicarbazone (mHtcum), using the yeast Saccharomyces cerevisiae as model system, to demonstrate how the compound can actually interfere with the mitochondrial respiratory chain.


Assuntos
Aflatoxinas/antagonistas & inibidores , Antifúngicos/farmacologia , Regulação Fúngica da Expressão Gênica , Mitocôndrias/efeitos dos fármacos , Saccharomyces cerevisiae/efeitos dos fármacos , Tiossemicarbazonas/farmacologia , Aflatoxinas/biossíntese , Antifúngicos/química , Aspergillus flavus/efeitos dos fármacos , Aspergillus flavus/enzimologia , Aspergillus flavus/genética , Sítios de Ligação , Transporte de Elétrons/efeitos dos fármacos , Complexo III da Cadeia de Transporte de Elétrons/antagonistas & inibidores , Complexo III da Cadeia de Transporte de Elétrons/química , Complexo III da Cadeia de Transporte de Elétrons/genética , Complexo III da Cadeia de Transporte de Elétrons/metabolismo , Proteínas Fúngicas/antagonistas & inibidores , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Mitocôndrias/metabolismo , Modelos Biológicos , Simulação de Acoplamento Molecular , Família Multigênica , Ligação Proteica , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/genética , Tiossemicarbazonas/química
4.
Sci Rep ; 7(1): 11214, 2017 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-28894265

RESUMO

The issue of food contamination by aflatoxins presently constitutes a social emergency, since they represent a severe risk for human and animal health. On the other hand, the use of pesticides has to be contained, since this generates long term residues in food and in the environment. Here we present the synthesis of a series of chelating ligands based on the thiosemicarbazone scaffold, to be evaluated for their antifungal and antiaflatoxigenic effects. Starting from molecules of natural origin of known antifungal properties, we introduced the thio- group and then the corresponding copper complexes were synthesised. Some molecules highlighted aflatoxin inhibition in the range 67-92% at 100 µM. The most active compounds were evaluated for their cytotoxic effects on human cells. While all the copper complexes showed high cytotoxicity in the micromolar range, one of the ligand has no effect on cell proliferation. This hit was chosen for further analysis of mutagenicity and genotoxicity on bacteria, plants and human cells. Analysis of the data underlined the importance of the safety profile evaluation for hit compounds to be developed as crop-protective agents and at the same time that the thiosemicarbazone scaffold represents a good starting point for the development of aflatoxigenic inhibitors.


Assuntos
Aflatoxinas/antagonistas & inibidores , Quelantes/farmacologia , Complexos de Coordenação/farmacologia , Cobre/metabolismo , Tiossemicarbazonas/farmacologia , Aspergillus flavus/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Quelantes/síntese química , Quelantes/química , Quelantes/toxicidade , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Complexos de Coordenação/toxicidade , Humanos , Ligantes , Viabilidade Microbiana/efeitos dos fármacos , Estrutura Molecular , Tiossemicarbazonas/síntese química , Tiossemicarbazonas/química , Tiossemicarbazonas/toxicidade , Oligoelementos
5.
Appl Microbiol Biotechnol ; 101(17): 6683-6696, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28725928

RESUMO

Aspergillus flavus is an opportunistic mold that represents a serious threat for human and animal health due to its ability to synthesize and release, on food and feed commodities, different toxic secondary metabolites. Among them, aflatoxin B1 is one of the most dangerous since it is provided with a strong cancerogenic and mutagenic activity. Controlling fungal contamination on the different crops that may host A. flavus is considered a priority by sanitary authorities of an increasing number of countries due also to the fact that, owing to global temperature increase, the geographic areas that are expected to be prone to experience sudden A. flavus outbreaks are widening. Among the different pre- and post-harvest strategies that may be put forward in order to prevent fungal and/or mycotoxin contamination, fungicides are still considered a prominent weapon. We have here analyzed different structural modifications of a natural-derived compound (cuminaldehyde thiosemicarbazone) for their fungistatic and anti-aflatoxigenic activity. In particular, we have focused our attention on one of the compound that presented a prominent anti-aflatoxin specificity, and performed a set of physiological and molecular analyses, taking also advantage of yeast (Saccharomyces cerevisiae) cell as an experimental model.


Assuntos
Aflatoxina B1/biossíntese , Aspergillus flavus/metabolismo , Benzaldeídos/química , Tiossemicarbazonas/química , Aspergillus flavus/genética , Produtos Agrícolas , Cimenos , Regulação Fúngica da Expressão Gênica , Proteômica , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo
6.
Food Chem Toxicol ; 105: 498-505, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28483535

RESUMO

Aflatoxins represent a serious problem for a food economy based on cereal cultivations used to fodder animal and for human nutrition. The aims of our work are two-fold: first, to perform an evaluation of the activity of newly synthesized thiosemicarbazone compounds as antifungal and anti-mycotoxin agents and, second, to conduct studies on the toxic and genotoxic hazard potentials with a battery of tests with different endpoints. In this paper we report an initial study on two molecules: S-4-isopropenylcyclohexen-1-carbaldehydethiosemicarbazone and its metal complex, bis(S-4-isopropenylcyclohexen-1-carbaldehydethiosemicarbazonato)nickel (II). The outcome of the assays on fungi growth and aflatoxin production inhibition show that both molecules possess good antifungal activities, without inducing mutagenic effects on bacteria. From the assays to ascertain that the compounds have no adverse effects on human cells, we have found that they are cytotoxic and, in the case of the nickel compound, they also present genotoxic effects.


Assuntos
Antifúngicos/química , Antifúngicos/farmacologia , Fungos/efeitos dos fármacos , Micotoxinas/metabolismo , Tiossemicarbazonas/química , Tiossemicarbazonas/farmacologia , Antifúngicos/efeitos adversos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Avaliação de Medicamentos , Avaliação Pré-Clínica de Medicamentos , Fungos/metabolismo , Humanos , Testes de Sensibilidade Microbiana , Mutagênicos/efeitos adversos , Mutagênicos/química , Mutagênicos/farmacologia , Tiossemicarbazonas/efeitos adversos
7.
Int J Food Microbiol ; 200: 104-11, 2015 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-25702884

RESUMO

With a steadily increasing world population, a more efficient system of food production is of paramount importance. One of the major causes of food spoilage is the presence of fungal pathogens and the production and accumulation of mycotoxins. In the present work we report a study on the activity of a series of functionalized thiosemicarbazones (namely cuminaldehyde, trans-cinnamaldehyde, quinoline-2-carboxyaldehyde, 5-fluoroisatin thiosemicarbazone and 5-fluoroisatin N(4)-methylthiosemicarbazone), as antifungal and anti-mycotoxin agents, against the two major genera of cereal mycotoxigenic fungi, i.e. Fusarium and Aspergillus. These thiosemicarbazones display different patterns of efficacy on fungal growth and on mycotoxin accumulation depending on the fungal species. Some of the molecules display a greater effect on mycotoxin synthesis than on fungal growth.


Assuntos
Antifúngicos/farmacologia , Grão Comestível/microbiologia , Microbiologia de Alimentos , Fungos/efeitos dos fármacos , Tiossemicarbazonas/farmacologia , Técnicas In Vitro
8.
J Public Health Res ; 4(3): 613, 2015 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-26753164

RESUMO

BACKGROUND: In the Po Valley aflatoxins play a relevant role: the local food economy is heavily based on cereal cultivations for animal feed and human nutrition. Aims of this project are the identification of new compounds that inhibit Aspergillus proliferation, the development of new inhibitors of aflatoxins production, and the set-up a practical screening procedure to identify the most effective and safe compounds. DESIGN AND METHODS: New compounds will be synthetized with natural origin molecules as ligands and endogenous metal ions to increase their bioavailability for the fungi as metal complexes. A biotechnological high-throughput screening will be set up to identify efficiently the most powerful substances. The newly synthesized compounds with effective antifungal activities, will be evaluated with battery of tests with different end-points to assess the toxic potential risk for environmental and human health. EXPECTED IMPACT OF THE STUDY FOR PUBLIC HEALTH: The fundamental step in the project will be the synthesis of new compounds and the study of their capability to inhibit aflatoxin biosynthesis. A new, simple, inexpensive and high-throughput method to screen the anti-fungine and anti-mycotoxin activity of the new synthesised compounds will be applied. The evaluation of possible risks for humans due to toxic and genotoxic activities of the molecules will be made with a new approach using different types of cells (bacteria, plants and human cells). Significance for public healthAflatoxins contamination constitutes a health emergency because aflatoxins and mycotoxins, besides being toxic, are among the most carcinogenic substances known. Even if Aspergillus are dominant in tropical regions, recently are becoming a serious problem also in Europe and in Italy, especially in area as the Po Valley in which this problem play a particularly important role, because the local food economy is heavily based not only on cereal cultivations aimed at animal feed but also on the production of derivatives to human nutrition. The aims of this research are the development of new bioactive molecules, obtained by natural molecules and metal ions, that are able to reduce the risk of food contamination by aflatoxin, but are harmless for environmental and health and the evaluation of the newly synthesized compounds using a battery of tests with different end-points to assess the toxic potential risk for environmental and human health.

9.
Plant Physiol Biochem ; 83: 225-31, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25180813

RESUMO

NAD(H)-glutamate dehydrogenase (GDH; EC 1.4.1.2) is an abundant and ubiquitous enzyme that may exist in different isoenzymic forms. Variation in the composition of the GDH isoenzyme pattern is observed during plant development and specific cell, tissue and organ localization of the different isoforms have been reported. However, the mechanisms involved in the regulation of the isoenzymatic pattern are still obscure. Regulation may be exerted at several levels, i.e. at the level of transcription and translation of the relevant genes, but also when the enzyme is assembled to originate the catalytically active form of the protein. In Arabidopsis thaliana, three genes (GDH1, GDH2 and GDH3) encode three different GDH subunits (ß, α and γ) that randomly associate to form a complex array of homo- and hetero-hexamers. In order to asses if the different Arabidopsis GDH isoforms may display different structural properties we have investigated their thermal stability. In particular the stability of GDH1 and GDH3 isoenzymes was studied using site-directed mutagenesis in a heterologous yeast expression system. It was established that the carboxyl terminus of the GDH subunit is involved in the stabilization of the oligomeric structure of the enzyme.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Desidrogenase de Glutamato (NADP+) , Temperatura Alta , Arabidopsis/enzimologia , Arabidopsis/genética , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Estabilidade Enzimática , Desidrogenase de Glutamato (NADP+)/química , Desidrogenase de Glutamato (NADP+)/genética , Desidrogenase de Glutamato (NADP+)/metabolismo , Isoenzimas , Subunidades Proteicas/química , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo
10.
Plant Physiol Biochem ; 73: 368-74, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24189523

RESUMO

In higher plants, NAD(H)-glutamate dehydrogenase (GDH; EC 1.4.1.2) is an abundant enzyme that exists in different isoenzymic forms. In Arabidopsis thaliana, three genes (Gdh1, Gdh2 and Gdh3) encode three different GDH subunits (ß, α and γ) that randomly associate to form a complex array of homo- and heterohexamers. The modification of the GDH isoenzyme pattern and its regulation was studied during the development of A. thaliana in the gdh1, gdh2 single mutants and the gdh1-2 double mutant, with particular emphasis on GDH3. Investigations showed that the GDH3 isoenzyme could not be detected in closely related Arabidopsis species. The induction and regulation of GDH3 activity in the leaves and roots was investigated following nitrogen deprivation in the presence or absence of sucrose or kinetin. These experiments indicate that GDH3 is likely to play an important role during senescence and nutrient remobilization.


Assuntos
Arabidopsis/genética , Metabolismo dos Carboidratos/genética , Carbono/metabolismo , Citocininas/metabolismo , Regulação da Expressão Gênica de Plantas , Glutamato Desidrogenase/genética , Nitrogênio/metabolismo , Arabidopsis/enzimologia , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Senescência Celular , Genes de Plantas , Glutamato Desidrogenase/metabolismo , Isoenzimas/genética , Isoenzimas/metabolismo , Cinetina/metabolismo , Mutação , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Multimerização Proteica , Subunidades Proteicas , Especificidade da Espécie , Sacarose/metabolismo
11.
Mutagenesis ; 17(2): 127-34, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11880541

RESUMO

Environmental pollution assessment and control are priority issues for both developed and developing countries of the world. The use of plant material for a more complete picture of environmental health appears to be particularly appealing. Here we validate a previous plant-adapted Comet assay on leaf tissues of Nicotiana tabacum cultivars Bel B and Bel W3. The effects of H(2)O(2) on DNA damage in Bel B and Bel W3 agree with the hypothesis that some component of the machinery that protects DNA integrity from oxidative stress may be impaired in cv. Bel W3. Exposure in the field on sunny summer days (peak ozone concentration >80 p.p.b.) showed significantly higher DNA damage in cv. Bel W3 if plants were collected and subjected to the Comet assay when the air ozone concentration was reaching its peak value, but not when plants were sampled early in the morning and hence after a period of low ozone concentration. The different results suggest that Bel W3 possesses a less efficient recovery apparatus that requires a longer period of activity to be effective and/or is less protected against reactive oxygen species production during exposure to ozone. However, it cannot be excluded that the increase in mean DNA damage is the result of the presence of a genotoxic agent(s) other than ozone. Interestingly, Bel W3 also appears to be more responsive, compared with Bel B, when exposed to ambient indoor pollutants. The use of cv. Bel W3 increases the sensitivity of the assay under both indoor and field conditions. However, different classes of mutagens should be tested to define the range of profitable utilization of this tobacco cultivar for environmental genotoxicity detection.


Assuntos
Poluentes Atmosféricos/farmacologia , Dano ao DNA/efeitos dos fármacos , DNA de Plantas/efeitos dos fármacos , Peróxido de Hidrogênio/farmacologia , Nicotiana/genética , Ozônio/farmacologia , Ensaio Cometa , Relação Dose-Resposta a Droga , Testes de Mutagenicidade , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Plantas Tóxicas
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