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Zouaoui N.,Laboratory for Research on Biologically Compatible Compounds LRSBC | Zouaoui N.,University of Carthage | Mallebrera B.,University of Valencia | Berrada H.,University of Valencia | And 3 more authors.
Food and Chemical Toxicology | Year: 2016

Mycotoxins are produced by different genera of fungi; mainly Aspergillus, Penicillium and Fusarium. The natural co-occurrence of beauvericin (BEA), patulin (PAT) and sterigmatocystin (STE) has been proved in feed and food commodities. This study investigates the cytotoxicity of individual and combined mycotoxins BEA, PAT and STE. The cytotoxicity on immortalized ovarian cells (CHO-K1) was evaluated using the MTT assay. After 24, 48 and 72 h, the IC50 values were 2.9 μM for PAT and ranged from 10.7 to 2.2 μM and from 25.0 to 12.5 μM for BEA and STE, respectively. Cytotoxic interactions were assayed by the isobologram method, which provides a combination index (CI) value as a quantitative measure of the three mycotoxin interaction's degree. Binary and tertiary combinations showed a dose dependent effect. At low fraction affected, mycotoxin combinations were synergetic; whereas, at higher fraction affected, the combinations showed additive effect. Our results indicate that the co-occurrence of low concentrations of mycotoxin in food may increase their toxic effects. © 2016 Elsevier Ltd.


Zaied C.,Laboratory for Research on Biologically Compatible Compounds LRSBC | Abid S.,Laboratory for Research on Biologically Compatible Compounds LRSBC | Mtiraoui N.,Research Unit of Haematological and Autoimmune Diseases | Zellema D.,CHU | And 2 more authors.
Genetic Testing and Molecular Biomarkers | Year: 2012

Aim: Human cytochrome P450 3A and glutathione S-transferase (GST) enzymes evolved to catalyze the metabolism of numerous common therapy drugs and endogenous molecules. Members of the CYP3A are the majority expressed in human liver and intestine. The genetic factors play an important role in the interindividual variability in CYP3A and GST activity. Detection of CYP3A4 and GST variant alleles and knowledge about their allelic frequency in specific ethnic groups are important to lead to individualized drug dosing and improved therapeutics. Methods: We determined the allelic frequency of the CYP3A4*18 and GSTP1 in a group of 138 healthy Tunisian subjects using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assays. It is based on a specific PCR product cut by restriction endonucleases. This method offers the advantage of cutting DNA by the appropriate restriction enzyme at the correct mutation site hence enhancing its reliability. Electrophoretic separation demonstrates the presence (or absence) of restriction sites. Results: In the group of 138 unrelated individuals, the frequencies of the CYP3A4*18 and GSTP1 variant allele in this Tunisian population were 0.02 and 0.01, respectively. Conclusions: The present study describes polymorphisms of Cyp3A4 and GST among Tunisian subjects. We developed a simple assay for the detection of the CYP3A4*18 and GSTP1 polymorphisms and we compared our allelic frequencies to other populations. No significant difference was obtained. This study provides the first analysis of CYP3A4*18 and GSTP1 mutant allele frequencies in the Tunisian population. © Copyright 2012, Mary Ann Liebert, Inc.


PubMed | Laboratory for Research on Biologically Compatible Compounds LRSBC, University of Valencia and University of Carthage
Type: | Journal: Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association | Year: 2016

Mycotoxins are produced by different genera of fungi; mainly Aspergillus, Penicillium and Fusarium. The natural co-occurrence of beauvericin (BEA), patulin (PAT) and sterigmatocystin (STE) has been proved in feed and food commodities. This study investigates the cytotoxicity of individual and combined mycotoxins BEA, PAT and STE. The cytotoxicity on immortalized ovarian cells (CHO-K1) was evaluated using the MTT assay. After 24, 48 and 72 h, the IC50 values were 2.9 M for PAT and ranged from 10.7 to 2.2 M and from 25.0 to 12.5 M for BEA and STE, respectively. Cytotoxic interactions were assayed by the isobologram method, which provides a combination index (CI) value as a quantitative measure of the three mycotoxin interactions degree. Binary and tertiary combinations showed a dose dependent effect. At low fraction affected, mycotoxin combinations were synergetic; whereas, at higher fraction affected, the combinations showed additive effect. Our results indicate that the co-occurrence of low concentrations of mycotoxin in food may increase their toxic effects.


Zaied C.,Laboratory for Research on Biologically Compatible Compounds LRSBC | Zouaoui N.,Laboratory for Research on Biologically Compatible Compounds LRSBC | Bacha H.,Laboratory for Research on Biologically Compatible Compounds LRSBC | Abid S.,Laboratory for Research on Biologically Compatible Compounds LRSBC
Food Control | Year: 2012

Fusarium mycotoxins are worldwide occurring in cereals and they are frequently reported in fresh or stored grains. Cereals represent a staple food for the Tunisian population; it therefore has a high social, economic and nutritional relevance. Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin produced by a variety of Fusarium fungi in temperate and warm countries. Fungi-producing ZEN contaminates corn, barley, wheat, sorghum and rice. A total of 205 samples of wheat were collected during the harvest year of 2010 from the major cropping areas in Tunisia and they were analyzed for zearalenone contamination. The aim of this study was to investigate for the first time the presence of ZEN in widely-consumed cereals in Tunisia, especially durum and tender wheat, to compare the levels of contamination by ZEN with the European norms and to suggest some factors that can promote the production of ZEN in Tunisia. To perform this study, we developed and validated in our laboratory conditions an HPLC method for quantitative analysis of ZEN in solid cereal samples. Our results showed that the incidence of ZEN contamination was 75%. The levels of contamination determined in the positive samples ranged between 3 and 560 μg/kg with a mean value of 60 μg/kg. These important amounts of ZEN in wheat can be attributed to the Tunisian climate, warm temperature and prolonged wetness witch are favor to Fusarium growth and mycotoxin production during the cultivation and the final ripening period of wheat grains. © 2011 Elsevier Ltd.


Zaied C.,Laboratory for Research on Biologically Compatible Compounds LRSBC | Abid S.,Laboratory for Research on Biologically Compatible Compounds LRSBC | Hlel W.,Laboratory for Research on Biologically Compatible Compounds LRSBC | Bacha H.,Laboratory for Research on Biologically Compatible Compounds LRSBC
Food Control | Year: 2013

Patulin (PAT) is a toxic metabolite produced by several filamentous fungi of the genera of Penicillium, Aspergillus and Byssochlamys, principally by Penicillium expansum. A total of 85 samples of apple products largely consumed by Tunisian population were analyzed for PAT content, including apple juice, baby food and mixed juice collected during 2011 from the major supermarkets and stores located in Tunisia. The aim of this study was to investigate the presence of PAT in the widely-consumed apple products in Tunisia, to compare the levels of PAT contamination with the European norms and to suggest some factors that can promote the production of this mycotoxin in our country. To perform this study, we developed and validated, in our laboratory conditions, an HPLC method for a quantitative analysis of PAT in apple products. Our results showed that the incidence of PAT contamination was 35%. The levels of contamination determined in the total samples ranged between 0 and 167 μg/l with a mean value of 20 μg/l and a median of 13 μg/l. Eighteen percent (18%) of the total juice samples (apple juices and mixed juices) and twenty-eight percent (28%) of the baby food samples exceeded the tolerable limit recommended by the European Union, which are respectively 50 μg/l and 10 μg/l. © 2012 Elsevier Ltd.


Zaied C.,Laboratory for Research on Biologically Compatible Compounds LRSBC | Zouaoui N.,Laboratory for Research on Biologically Compatible Compounds LRSBC | Bacha H.,Laboratory for Research on Biologically Compatible Compounds LRSBC | Abid S.,Laboratory for Research on Biologically Compatible Compounds LRSBC
Food Control | Year: 2012

Citrinin (CIT) is a toxic metabolite produced by several filamentous fungi of the genera . Penicillium, . Aspergillus and . Monascus, which has been known as a natural contaminant in cereal grains, foods and feedstuffs. CIT is a quinone methide with a powerful antibacterial effect, but toxic to humans and animals. This mycotoxin is mainly hepato-nephrotoxic, indeed it was implicated as a potential causative agent in human Balkan Endemic Nephropathy (BEN) associated with an increased frequency of urinary tract tumors in animals and humans. A total of 200 samples of wheat were collected during the harvest year of 2010 from the major cropping areas in Tunisia and they were analyzed for citrinin contamination. These samples were taken after the harvest which can last up to three months. During this period, . Penicillium and . Aspergillus can growth on the harvested crop and produce CIT. The aim of this study was to investigate for the first time the presence of CIT in widely-consumed cereals in Tunisia, especially in wheat, and to suggest some factors that can promote the production of CIT in Tunisia. To perform this study, we developed and validated in our laboratory conditions an HPLC method for quantitative analysis of CIT in solid cereal samples. Our results showed that the incidence of CIT contamination was 50%. The levels of contamination determined in the positive samples ranged between 01 and 170 μg/kg with an average of 28 μg/kg. These amounts of CIT in wheat are chiefly attributed to the geographic position of Tunisia as a Mediterranean country characterized by a climate that favors fungal proliferation and mycotoxins production. © 2012 Elsevier Ltd.


Zouaoui N.,Laboratory for Research on Biologically Compatible Compounds LRSBC | Sbaii N.,Laboratory for Research on Biologically Compatible Compounds LRSBC | Bacha H.,Laboratory for Research on Biologically Compatible Compounds LRSBC | Abid-Essefi S.,Laboratory for Research on Biologically Compatible Compounds LRSBC
Food Control | Year: 2015

Patulin (PAT) is a secondary metabolite, which is mainly produced by certain species of Aspergillus and Penicillium fungi. The objective of this study is to investigate the presence of Patulin in various fruit products marketed and consumed in Tunisia. A total of 214 samples (30 concentrated juice samples, 42 apple juice samples, 42 pear juice samples, 34 mixed juice samples, 35 compote samples, 15 apple jams samples and 16 pear jam samples) were analyzed. The incidence of PAT contamination was 50% with a concentration ranging from 2 to 889μg/l with an average of 89μg/l and a median of 41μg/l. Twenty two percent (22%) of total analyzed samples exceeded the limit recommended by the European Union. Our results showed that PAT seems to be a problem in fruit products marketed in Tunisia, which required and recommended a hard and fast surveillance of this toxin. © 2014 .


Ayed Y.,Laboratory for Research on Biologically Compatible Compounds LRSBC | Ayed-Boussema I.,Laboratory for Research on Biologically Compatible Compounds LRSBC | Ouanes Z.,Laboratory for Research on Biologically Compatible Compounds LRSBC | Bacha H.,Laboratory for Research on Biologically Compatible Compounds LRSBC
Mutation Research - Genetic Toxicology and Environmental Mutagenesis | Year: 2011

Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin produced by Fusarium fungi. It contaminates different components of the food chain and can cause serious economic and public health problems. The major metabolites of ZEN in various animal species are alpha- and beta-zearalenol (α-, β-ZOL). Some in vivo studies have shown that these two metabolites are as toxic as the mother molecule (ZEN), but other investigations have demonstrated that α- and β-ZOL are less toxic than ZEN. Thus, the aim of the present study was to evaluate cytotoxicity and genotoxicity of α- and β-ZOL in vivo, in mouse bone-marrow cells and in vitro, in cultured HeLa cells, and to compare it with ZEN. ZEN showed the same cytotoxicity as α-ZOL and both are more cytotoxic than β-ZOL. Genotoxicity of ZEN and its derivatives was assessed by the chromosome aberration assay. Our results show that ZEN as well as α- and β-ZOL increased the percentage of chromosome aberrations in mouse bone-marrow cells and in HeLa cells. In the two systems, ZEN and α-ZOL exhibited the same range of genotoxicity and both were more genotoxic than β-ZOL. Furthermore, our results show that either ZEN or its two metabolites inhibited cell viability in a dose-dependent manner. We conclude that biotransformation of ZEN may be considered as only a partial detoxification pathway since the resulting metabolites remain relatively toxic. © 2011 Elsevier B.V.


PubMed | French Institute of Health and Medical Research and Laboratory for Research on Biologically Compatible Compounds LRSBC
Type: Journal Article | Journal: Environmental science and pollution research international | Year: 2016

-zearalenol (-ZOL) and -zearalenol (-ZOL) are the major metabolites of Zearalenone (ZEN) and are known to induce many toxic effects. In the present study, we investigated the involvement of endoplasmic reticulum (ER) stress in - and -ZOL-mediated toxicity in human kidney cells (HEK293) and evaluated the effect of a common dietary compound Crocin (CRO), from saffron. We show that - and -ZOL treatment induces ER stress as evidenced by the upregulation of the 78kDa glucose-regulated protein (GRP78) and the Growth arrest and DNA damage-inducible protein (GADD34). Activation of the ER stress response is associated with activation of the mitochondrial pathway of apoptosis. This apoptotic process is characterized by an increase in ROS generation and lipid peroxidation, a loss of mitochondrial transmembrane potential (m) and activation of caspases. We also demonstrate that the antioxidant properties of CRO help to prevent ER stress and reduce - and -ZOL-induced apoptosis in HEK293 cells. Our results suggest that saffron consumption might be helpful to prevent - and -ZOL-induced ER stress and toxicity.


PubMed | Laboratory for Research on Biologically Compatible Compounds LRSBC
Type: Journal Article | Journal: Genetic testing and molecular biomarkers | Year: 2012

Human cytochrome P450 3A and glutathione S-transferase (GST) enzymes evolved to catalyze the metabolism of numerous common therapy drugs and endogenous molecules. Members of the CYP3A are the majority expressed in human liver and intestine. The genetic factors play an important role in the interindividual variability in CYP3A and GST activity. Detection of CYP3A4 and GST variant alleles and knowledge about their allelic frequency in specific ethnic groups are important to lead to individualized drug dosing and improved therapeutics.We determined the allelic frequency of the CYP3A4*18 and GSTP1 in a group of 138 healthy Tunisian subjects using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assays. It is based on a specific PCR product cut by restriction endonucleases. This method offers the advantage of cutting DNA by the appropriate restriction enzyme at the correct mutation site hence enhancing its reliability. Electrophoretic separation demonstrates the presence (or absence) of restriction sites.In the group of 138 unrelated individuals, the frequencies of the CYP3A4*18 and GSTP1 variant allele in this Tunisian population were 0.02 and 0.01, respectively.The present study describes polymorphisms of Cyp3A4 and GST among Tunisian subjects. We developed a simple assay for the detection of the CYP3A4*18 and GSTP1 polymorphisms and we compared our allelic frequencies to other populations. No significant difference was obtained. This study provides the first analysis of CYP3A4*18 and GSTP1 mutant allele frequencies in the Tunisian population.

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