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1.
J Hazard Mater ; 473: 134716, 2024 Jul 15.
Article de Anglais | MEDLINE | ID: mdl-38797074

RÉSUMÉ

Ochratoxin A (OTA) is a toxic secondary metabolite that widely contaminates agro-products and poses a significant dietary risk to human health. Previously, a carboxypeptidase CP4 was characterized for OTA degradation in Lysobacter sp. CW239, but the degradation activity was much lower than its host strain CW239. In this study, an amidohydrolase ADH2 was screened for OTA hydrolysis in this strain. The result showed that 50 µg/L OTA was completely degraded by 1.0 µg/mL rADH2 within 5 min, indicating ultra-efficient activity. Meanwhile, the two hydrolases (i.e., CP4 and ADH2) in the strain CW239 showed the same degradation manner, which transformed the OTA to ochratoxin α (OTα) and l-ß-phenylalanine. Gene mutants (Δcp4, Δadh2 and Δcp4-adh2) testing result showed that OTA was co-degraded by carboxypeptidase CP4 and amidohydrolase ADH2, and the two hydrolases are sole agents in strain CW239 for OTA degradation. Hereinto, the ADH2 was the overwhelming efficient hydrolase, and the two types of hydrolases co-degraded OTA in CW239 by synergistic effect. The results of this study are highly significant to ochratoxin A contamination control during agro-products production and postharvest.


Sujet(s)
Lysobacter , Ochratoxines , Ochratoxines/métabolisme , Ochratoxines/toxicité , Lysobacter/métabolisme , Lysobacter/génétique , Amidohydrolases/métabolisme , Amidohydrolases/génétique , Carboxypeptidases/métabolisme , Carboxypeptidases/génétique , Hydrolases/métabolisme , Hydrolases/génétique
2.
Food Chem Toxicol ; 189: 114740, 2024 Jul.
Article de Anglais | MEDLINE | ID: mdl-38759715

RÉSUMÉ

Mycotoxins are low molecular weight compounds present in food and feed. Although their effects on human health have been widely described, their mechanisms of action are still undefined. Gliotoxin (GTX) and ochratoxin A (OTA) are among the most dangerous mycotoxins produced by Aspergillus spp. Therefore, their toxicity was studied in the Daphnia magna model, which has high capacity to predict cytotoxicity and assess ecotoxicity, comparable to mammalian models. The study consisted of a series of tests to evaluate the effects of mycotoxins GTX, OTA and their combinations at different dilutions on Daphnia magna that were conducted according to standardized OECD 202 and 211 guidelines. The following assays were carried out: acute toxicity test, heartbeat, delayed toxicity test, reproduction, growth rate test. Reproducibility was determined by observing the offspring after 21 days of GTX exposure. In acute and delayed toxicity transcript levels of genes involved in xenobiotic metabolism (mox, gst, abcb1, and abcc5), and oxidative stress (vtg-SOD) were analyzed by qPCR. GTX showed acute toxicity and decreased heart rate in D. magna compared to OTA. On the other hand, OTA showed a delayed effect as evidenced by the immobility test. Both mycotoxins showed to increase genes involved in xenobiotic metabolism, while only the mycotoxin mixture increased oxidative stress. These results suggest that the mycotoxins tested could have negative impact on the environment and human health.


Sujet(s)
Daphnia , Gliotoxine , Ochratoxines , Daphnia/effets des médicaments et des substances chimiques , Ochratoxines/toxicité , Animaux , Gliotoxine/toxicité , Contamination des aliments/analyse , Reproduction/effets des médicaments et des substances chimiques , Daphnia magna
3.
Food Res Int ; 187: 114409, 2024 Jul.
Article de Anglais | MEDLINE | ID: mdl-38763660

RÉSUMÉ

Ochratoxin A (OTA) is a notorious mycotoxin commonly contaminating food products worldwide. In this study, an OTA-degrading strain Brevundimonas diminuta HAU429 was isolated by using hippuryl-L-phenylalanine as the sole carbon source. The biodegradation of OTA by strain HAU429 was a synergistic effect of intracellular and extracellular enzymes, which transformed OTA into ochratoxin α (OTα) through peptide bond cleavage. Cytotoxicity tests and cell metabolomics confirmed that the transformation of OTA into OTα resulted in the detoxification of its hepatotoxicity since OTA but not OTα disturbed redox homeostasis and induced oxidative damage to hepatocytes. Genome mining identified nine OTA hydrolase candidates in strain HAU429. They were heterologously expressed in Escherichia coli, and three novel amidohydrolase BT6, BT7 and BT9 were found to display OTA-hydrolyzing activity. BT6, BT7 and BT9 showed less than 45 % sequence identity with previously identified OTA-degrading amidohydrolases. BT6 and BT7 shared 60.9 % amino acid sequence identity, and exhibited much higher activity towards OTA than BT9. BT6 and BT7 could completely degrade 1 µg mL-1 of OTA within 1 h and 50 min, while BT9 hydrolyzed 100 % of OTA in the reaction mixture by 12 h. BT6 was the most thermostable retaining 38 % of activity after incubation at 70 °C for 10 min, while BT7 displayed the highest tolerance to ethanal remaining 76 % of activity in the presence of 6 % ethanol. This study could provide new insights towards microbial OTA degradation and promote the development of enzyme-catalyzed OTA detoxification during food processing.


Sujet(s)
Caulobacteraceae , Ochratoxines , Ochratoxines/métabolisme , Ochratoxines/toxicité , Caulobacteraceae/métabolisme , Caulobacteraceae/génétique , Dépollution biologique de l'environnement , Amidohydrolases/métabolisme , Amidohydrolases/génétique , Contamination des aliments
4.
Toxins (Basel) ; 16(5)2024 Apr 26.
Article de Anglais | MEDLINE | ID: mdl-38787059

RÉSUMÉ

The aims of this study were (i) to determine the effect of an algoclay-based decontaminant on the oral availability of three mycotoxins (deoxynivalenol; DON, ochratoxin A; OTA, and aflatoxin B1; AFB1) using an oral bolus model and (ii) to determine the effect of this decontaminant on the performance, intestinal morphology, liver oxidative stress, and metabolism, in broiler chickens fed a diet naturally contaminated with DON. In experiment 1, sixteen 27-day-old male chickens (approximately 1.6 kg body weight; BW) were fasted for 12 h and then given a bolus containing either the mycotoxins (0.5 mg DON/kg BW, 0.25 mg OTA/kg BW, and 2.0 mg AFB1/kg BW) alone (n = 8) or combined with the decontaminant (2.5 g decontaminant/kg feed; circa 240 mg/kg BW) (n = 8). Blood samples were taken between 0 h (before bolus administration) and 24 h post-administration for DON-3-sulphate, OTA, and AFB1 quantification in plasma. The algoclay decontaminant decreased the relative oral bioavailability of DON (39.9%), OTA (44.3%), and AFB1 (64.1%). In experiment 2, one-day-old male Ross broilers (n = 600) were divided into three treatments with ten replicates. Each replicate was a pen with 20 birds. The broiler chickens were fed a control diet with negligible levels of DON (0.19-0.25 mg/kg) or diets naturally contaminated with moderate levels of DON (2.60-2.91 mg/kg), either supplemented or not with an algoclay-based decontaminant (2 g/kg diet). Jejunum villus damage was observed on day 28, followed by villus shortening on d37 in broiler chickens fed the DON-contaminated diet. This negative effect was not observed when the DON-contaminated diet was supplemented with the algoclay-based decontaminant. On d37, the mRNA expression of glutathione synthetase was significantly increased in the liver of broiler chickens fed the DON-contaminated diet. However, its expression was similar to the control when the birds were fed the DON-contaminated diet supplemented with the algoclay-based decontaminant. In conclusion, the algoclay-based decontaminant reduced the systemic exposure of broiler chickens to DON, OTA, and AFB1 in a single oral bolus model. This can be attributed to the binding of the mycotoxins in the gastrointestinal tract. Moreover, dietary contamination with DON at levels between 2.69 and 2.91 mg/kg did not impair production performance but had a negative impact on broiler chicken intestinal morphology and the liver redox system. When the algoclay-based decontaminant was added to the diet, the harm caused by DON was no longer observed. This correlates with the results obtained in the toxicokinetic assay and can be attributed to a decreased absorption of DON.


Sujet(s)
Aflatoxine B1 , Aliment pour animaux , Poulets , Contamination des aliments , Foie , Ochratoxines , Stress oxydatif , Trichothécènes , Animaux , Trichothécènes/toxicité , Stress oxydatif/effets des médicaments et des substances chimiques , Mâle , Ochratoxines/toxicité , Foie/effets des médicaments et des substances chimiques , Foie/métabolisme , Foie/anatomopathologie , Aflatoxine B1/toxicité , Aliment pour animaux/analyse , Intestins/effets des médicaments et des substances chimiques , Intestins/anatomopathologie , Toxicocinétique , Régime alimentaire/médecine vétérinaire , Silicates d'aluminium
5.
Ecotoxicol Environ Saf ; 276: 116277, 2024 May.
Article de Anglais | MEDLINE | ID: mdl-38604061

RÉSUMÉ

Ochratoxin A (OTA) is a common fungal toxin frequently detected in food and human plasma samples. Currently, the physiologically based toxicokinetic (PBTK) model plays an active role in dose translation and can improve and enhance the risk assessment of toxins. In this study, the PBTK model of OTA in rats and humans was established based on knowledge of OTA-specific absorption, distribution, metabolism, and excretion (ADME) in order to better explain the disposition of OTA in humans and the discrepancies with other species. The models were calibrated and optimized using the available kinetic and toxicokinetic (TK) data, and independent test datasets were used for model evaluation. Subsequently, sensitivity analyses and population simulations were performed to characterize the extent to which variations in physiological and specific chemical parameters affected the model output. Finally, the constructed models were used for dose extrapolation of OTA, including the rat-to-human dose adjustment factor (DAF) and the human exposure conversion factor (ECF). The results showed that the unbound fraction (Fup) of OTA in plasma of rat and human was 0.02-0.04% and 0.13-4.21%, respectively. In vitro experiments, the maximum enzyme velocity (Vmax) and Michaelis-Menten constant (Km) of OTA in rat and human liver microsomes were 3.86 and 78.17 µg/g min-1, 0.46 and 4.108 µg/mL, respectively. The predicted results of the model were in good agreement with the observed data, and the models in rats and humans were verified. The PBTK model derived a DAF of 0.1081 between rats and humans, whereas the ECF was 2.03. The established PBTK model can be used to estimate short- or long-term OTA exposure levels in rats and humans, with the capacity for dose translation of OTA to provide the underlying data for risk assessment of OTA.


Sujet(s)
Modèles biologiques , Ochratoxines , Toxicocinétique , Ochratoxines/toxicité , Ochratoxines/pharmacocinétique , Animaux , Rats , Humains , Appréciation des risques , Mâle
6.
Arch Toxicol ; 98(7): 2281-2295, 2024 Jul.
Article de Anglais | MEDLINE | ID: mdl-38546835

RÉSUMÉ

Ochratoxin A (OTA) is a widespread food toxin produced by Aspergillus ochraceus and other molds. In this study, we developed and established acute OTA toxicity conditions in mice, which received daily oral doses of OTA between 0.5 up to 8 mg/kg body weight up to 7 days and were subjected to histological and biochemical analysis to characterize renal and hepatic damage. Oral administration of OTA for 7 days resulted in loss of body weight in a dose-dependent manner and increased the levels of serum biomarkers of hepatic and renal damage. The kidney was more sensitive to OTA-induced damage than the liver. In addition to necrosis, OTA induced hepatic and renal apoptosis in dose- and time-dependent manners. Especially, a high dose of OTA (8 mg/kg body weight) administered for 7 days led to necroptosis in both liver and kidney tissues. OTA dose-dependently increased the oxidative stress levels, including lipid peroxidation, in the liver and kidneys. OTA disrupted mitochondrial dynamics and structure in hepatic and renal cells, leading to the dysregulation of mitochondrial homeostasis. OTA increased transferrin receptor 1 and decreased glutathione peroxidase 4 levels in a dose- and time-dependent manner. These results suggest the induction of ferroptosis. Collectively, this study highlighted the characteristics of acute OTA-induced hepatic and renal toxicity in mice in terms of oxidative stress, mitochondrial damage, and multiple cell death mechanisms, including necroptosis and ferroptosis.


Sujet(s)
Lésions hépatiques dues aux substances , Rein , Foie , Mitochondries , Ochratoxines , Stress oxydatif , Animaux , Ochratoxines/toxicité , Stress oxydatif/effets des médicaments et des substances chimiques , Rein/effets des médicaments et des substances chimiques , Rein/anatomopathologie , Rein/métabolisme , Foie/effets des médicaments et des substances chimiques , Foie/anatomopathologie , Foie/métabolisme , Souris , Mâle , Mitochondries/effets des médicaments et des substances chimiques , Mitochondries/métabolisme , Lésions hépatiques dues aux substances/anatomopathologie , Lésions hépatiques dues aux substances/métabolisme , Lésions hépatiques dues aux substances/étiologie , Relation dose-effet des médicaments , Apoptose/effets des médicaments et des substances chimiques , Peroxydation lipidique/effets des médicaments et des substances chimiques , Ferroptose/effets des médicaments et des substances chimiques , Nécroptose/effets des médicaments et des substances chimiques
7.
Food Funct ; 15(8): 3980-3992, 2024 Apr 22.
Article de Anglais | MEDLINE | ID: mdl-38482731

RÉSUMÉ

Ochratoxin A (OTA), commonly found in various foods, significantly impacts the health of humans and animals, especially their kidneys. Our study explores OTA's effects on the gut microbiota and kidney damage while examining how postbiotics offer protection. Using metagenomic sequencing, we observed that OTA increased the potential gut pathogens such as Alistipes, elevating detrimental metabolites and inflammation. Also, OTA inhibited the Nrf2/HO-1 pathway, reducing kidney ROS elimination and leading to cellular ferroptosis and subsequent kidney damage. Postbiotics mitigate OTA's effects by downregulating the abundance of the assimilatory sulfate reduction IV pathway and virulence factors associated with iron uptake and relieving the inhibition of OTA on Nrf2/HO-1, restoring ROS-clearing capabilities and thereby alleviating chronic OTA-induced kidney damage. Understanding the OTA-gut-kidney link provides new approaches for preventing kidney damage, with postbiotics showing promise as a preventive treatment.


Sujet(s)
Microbiome gastro-intestinal , Rein , Ochratoxines , Ochratoxines/toxicité , Microbiome gastro-intestinal/effets des médicaments et des substances chimiques , Animaux , Rein/effets des médicaments et des substances chimiques , Rein/métabolisme , Souris , Mâle , Maladies du rein/induit chimiquement , Maladies du rein/métabolisme , Facteur-2 apparenté à NF-E2/métabolisme , Souris de lignée C57BL , Humains , Espèces réactives de l'oxygène/métabolisme
8.
Environ Sci Pollut Res Int ; 31(19): 27864-27882, 2024 Apr.
Article de Anglais | MEDLINE | ID: mdl-38526719

RÉSUMÉ

Ochratoxin A (OTA) is a widespread environmental toxin that poses a serious threat to human and animal health. OTA has been shown to cause cellular and tissue damage and is a global public health problem. However, the effects of OTA on gastrointestinal aging have not been reported. The aim of this study was to investigate the effects of OTA on intestinal aging in vitro and in vivo. In vitro experiments showed that OTA induced cellular inflammation through calcium overload and oxidative stress, significantly up-regulated the expression of P16, P21, and P53 proteins, markedly increased senescence-associated ß-galactosidase activity (SA-ß-gal) positive cells, and obviously decreased the expression of proliferating cell nuclear antigen (PCNA) proteins, which led to intestinal cell senescence. Meanwhile, we found that treatment with ß-carotene ameliorated OTA-induced intestinal cell senescence. Consistent with the results of the in vitro experiments, in vivo studies showed that the intestinal aging of mice fed OTA was significantly higher than that of the control group. In conclusion, OTA may induce intestinal aging through calcium overload, oxidative stress and inflammation. This study lays a foundation for further research on the toxicological effects of OTA.


Sujet(s)
Calcium , Protéine-3 de la famille des NLR contenant un domaine pyrine , Ochratoxines , Stress oxydatif , Transduction du signal , Ochratoxines/toxicité , Stress oxydatif/effets des médicaments et des substances chimiques , Souris , Animaux , Protéine-3 de la famille des NLR contenant un domaine pyrine/métabolisme , Calcium/métabolisme , Transduction du signal/effets des médicaments et des substances chimiques , Intestins/effets des médicaments et des substances chimiques , Vieillissement de la cellule/effets des médicaments et des substances chimiques
9.
Toxicology ; 503: 153765, 2024 Mar.
Article de Anglais | MEDLINE | ID: mdl-38432407

RÉSUMÉ

Ochratoxin A (OTA) is a mycotoxin spread worldwide contaminating several food and feed commodities and rising concerns for humans and animals. OTA toxicity has been thoroughly assessed over the last 60 years revealing a variety of adverse effects, including nephrotoxicity, hepatotoxicity and possible carcinogenicity. However, the underpinning mechanisms of action have yet to be completely displayed and understood. In this framework, we applied a virtual pipeline based on molecular docking, dynamics and umbrella simulations to display new OTA potential targets. The results collected consistently identified OGFOD1, a key player in protein translation, as possibly inhibited by OTA and its 2'R diastereomer. This is consistent with the current knowledge of OTA's molecular toxicology and may fill some gaps from a mechanistic standpoint. This could pave the way for further dedicated analysis focusing their attention on the OTA-OGFOD1 interaction, expanding the current understanding of OTA toxicity at a molecular level.


Sujet(s)
Mycotoxines , Ochratoxines , Humains , Animaux , Simulation de docking moléculaire , Ochratoxines/toxicité , Contamination des aliments , Protéines de transport , Protéines nucléaires/métabolisme
10.
Food Chem ; 447: 138909, 2024 Jul 30.
Article de Anglais | MEDLINE | ID: mdl-38489879

RÉSUMÉ

The purpose of this review was to investigate the current knowledge about aflatoxin B1 (AFB1) and ochratoxin A (OTA) toxicity and the possible beneficial role of bioactive compounds by using in vitro and in vivo models. Although AFB1 and OTA were tested in a similar percentage, the majority of studies focused on nephrotoxicity, hepatotoxicity, immune toxicity and neurotoxicity in which oxidative stress, inflammation, structural damage and apoptosis were the main mechanisms of action reported. Conversely, several biological compounds were assayed in order to modulate mycotoxins damage mainly in the liver, brain, kidney and immune system. Among them, pumpkin, curcumin and fermented whey were the most employed. Although a clear progress has been made by using in vivo models, further research is needed to assess not only the toxicity of multiple mycotoxins contamination but also the effect of functional compounds mixture, thereby reproducing more realistic situations for human health risk assessment.


Sujet(s)
Mycotoxines , Ochratoxines , Humains , Aflatoxine B1/toxicité , Ochratoxines/toxicité , Mycotoxines/toxicité , Foie
11.
Appl Microbiol Biotechnol ; 108(1): 230, 2024 Feb 23.
Article de Anglais | MEDLINE | ID: mdl-38393350

RÉSUMÉ

The presence of ochratoxin A (OTA) in food and feed represents a serious concern since it raises severe health implications. Bacterial strains of the Acinetobacter genus hydrolyse the amide bond of OTA yielding non-toxic OTα and L-ß-phenylalanine; in particular, the carboxypeptidase PJ15_1540 from Acinetobacter sp. neg1 has been identified as an OTA-degrading enzyme. Here, we describe the ability to transform OTA of cell-free protein extracts from Acinetobacter tandoii DSM 14970 T, a strain isolated from sludge plants, and also report on the finding of a new and promiscuous α/ß hydrolase (ABH), with close homologs highly distributed within the Acinetobacter genus. ABH from A. tandoii (AtABH) exhibited amidase activity against OTA and OTB mycotoxins, as well as against several carboxypeptidase substrates. The predicted structure of AtABH reveals an α/ß hydrolase core composed of a parallel, six-stranded ß-sheet, with a large cap domain similar to the marine esterase EprEst. Further biochemical analyses of AtABH reveal that it is an efficient esterase with a similar specificity profile as EprEst. Molecular docking studies rendered a consistent OTA-binding mode. We proposed a potential procedure for preparing new OTA-degrading enzymes starting from promiscuous α/ß hydrolases based on our results. KEY POINTS: • AtABH is a promiscuous αß hydrolase with both esterase and amidohydrolase activities • AtABH hydrolyses the amide bond of ochratoxin A rendering nontoxic OTα • Promiscuous αß hydrolases are a possible source of new OTA-degrading enzymes.


Sujet(s)
Acinetobacter , Mycotoxines , Ochratoxines , Mycotoxines/métabolisme , Hydrolases/métabolisme , Simulation de docking moléculaire , Ochratoxines/métabolisme , Ochratoxines/toxicité , Acinetobacter/métabolisme , Carboxypeptidases/métabolisme , Esterases/métabolisme , Amides/métabolisme
12.
Food Chem Toxicol ; 185: 114486, 2024 Mar.
Article de Anglais | MEDLINE | ID: mdl-38301995

RÉSUMÉ

Ochratoxin A (OTA) is a renal carcinogen in rats, and repeated administration induces karyomegaly in proximal tubular epithelial cells (PTECs) of the outer stripe of the outer medulla (OSOM) before inducing proliferative lesions. To investigate whether OTA induces micronuclei (MN) in PTECs, we performed an in vitro MN assay using rat renal NRK-52E PTECs after treatment for ≤21 days, and an in vivo OSOM MN assay in rats treated with OTA, other renal carcinogens, or non-carcinogenic renal toxicants for 4 or 13 weeks. The in vitro assay revealed an increased frequency of micronucleated cells from the acceptable dose level for cell viability, even after 21 days of treatment. The in vivo assay also revealed a dose- and treatment period-dependent increase in PTECs with γ-H2AX+ MN. OTA-specific gene expression profiling by OSOM RNA sequencing after week 13 revealed the altered expression of genes related to microtubule-kinetochore binding, the kinesin superfamily, centriole assembly, DNA damage repair, and cell cycle regulation. MN formation was also observed with other renal carcinogens that induce karyomegaly similarly to OTA. These results imply that γ-H2AX+ MN formation by OTA treatment is related to the induction of chromosomal instability accompanying karyomegaly formation before proliferative lesions form, providing a new insight into the carcinogenic mechanism that may be relevant to humans.


Sujet(s)
Ochratoxines , Humains , Rats , Animaux , Ochratoxines/toxicité , Cancérogènes , Cellules épithéliales , Instabilité des chromosomes
13.
Biosens Bioelectron ; 248: 115995, 2024 Mar 15.
Article de Anglais | MEDLINE | ID: mdl-38176255

RÉSUMÉ

To measure toxins using immunoassays, hazardous toxin standards need to be added for quantification. To solve this problem, we propose to use aptamers as competitors to replace toxin standards. In this work, aptamers specific for ochratoxin A (OTA) nanobodies were selected using a DNA library containing a 36 nucleotide random region. The obtained sequences were highly aligned and the best competitor was identified to be a sequence named apt2-OT based on an indirect competitive enzyme-linked immunosorbent assay (ELISA). The Kd of apt2-OT was measured to be 2.86 µM using local surface plasmon resonance spectroscopy. The optimal apt2-OT was identified to substitute the OTA standard with a concentration needed for 50% inhibition of binding (IC50) of 3.26 µM based on a nontoxic direct competitive ELISA. The equivalence relationship between the aptamer and OTA was established in a flour sample, and a recovery experiment was performed. The detection limit for this method was 0.23 ng/mL, with a linear range from 0.25 to 10.50 ng/mL. The recovery rate was 97.5%-115.5%. This study provides a low-cost, rapid and environmentally friendly alternative to the development of immunoassays for toxins.


Sujet(s)
Aptamères nucléotidiques , Techniques de biocapteur , Ochratoxines , Anticorps à domaine unique , Aptamères nucléotidiques/composition chimique , Techniques de biocapteur/méthodes , Ochratoxines/toxicité , Ochratoxines/analyse , Dosage immunologique , Limite de détection
14.
Toxicol Lett ; 393: 24-32, 2024 Mar.
Article de Anglais | MEDLINE | ID: mdl-38244709

RÉSUMÉ

Mycotoxins such as gliotoxin (GTX) and ochratoxin A (OTA) are secondary metabolites of Aspergillus and Penicillum found in food and feed. Both mycotoxins have shown to exert a detrimental effect on neuronal activity. The following study was carried out to elucidate the mechanisms by which GTX and OTA exert their toxicity. Non-differentiated SH-SY5Y neuronal-like cells were treated with GTX, OTA and their combinations to assess their cytotoxic effect using the MTT assay during 24, 48 and 72 h of exposure. Based on the results of the cytotoxic assays, cell cycle proliferation and immunological mediators were measured by determining the production of IL-6 and TNF-α using flow cytometry and ELISA, respectively. The IC50 values obtained were 1.24 and 1.35 µM when SH-SY5Y cells were treated with GTX at 48 h and 72 h, respectively. IC50 values of 8.25, 5.49 and 4.5 µM were obtained for OTA treatment at 24 h, 48 h and 72 h, respectively. The SubG0 phase increased in both treatments at 24 and 48 h. On the other hand, IL-6 and TNF-α production was increased in all mycotoxin treatments studied and was more pronounced for [GTX + OTA] after 48 h exposure. The additive and synergistic effect observed by the isobologram analysis between GTX and OTA resulted to a higher cytotoxicity which can be explained by the increased production of IL-6 and TNF-α inflammatory mediators that play an important role in the toxicity mechanism of these mycotoxins.


Sujet(s)
Gliotoxine , Mycotoxines , Neuroblastome , Ochratoxines , Humains , Gliotoxine/toxicité , Facteur de nécrose tumorale alpha/pharmacologie , Interleukine-6 , Ochratoxines/toxicité , Mycotoxines/toxicité , Cycle cellulaire
15.
Environ Sci Pollut Res Int ; 31(4): 5473-5483, 2024 Jan.
Article de Anglais | MEDLINE | ID: mdl-38114706

RÉSUMÉ

Ochratoxin A (OTA) is a well-known mycotoxin that adversely affects different human cells. Inhalational exposure to OTA and subsequent pulmonary diseases have been previously reported, yet its potential carcinogenicity and underlying molecular mechanisms have not been fully elucidated. This study aimed to evaluate the OTA-induced cytotoxicity and the epigenetic changes underlying its potential carcinogenicity in fetal lung fibroblast (WI-38) cells. OTA cytotoxicity was assessed by MTT assay; RT-qPCR was used to determine the expression of BAX, BCL-2, TP53, and miR-155, while ELISA was used for measuring 5-methyl cytosine percentage to assess global DNA methylation in OTA-treated versus control cells. WI-38 cells demonstrated sensitivity to OTA with IC50 at 22.38 µM. Though BAX and Bcl-2 were downregulated, with low BAX/BCL-2 ratio, and TP53 was upregulated, their fold changes showed decline trend with increasing OTA concentration. A significant dose-dependent miR-155 upregulation was observed, with dynamic time-related decline. Using subtoxic OTA concentrations, a significant global DNA hypermethylation with significant dose-dependent and dynamic alterations was identified. Global DNA hypermethylation and miR-155 upregulation are epigenetic mechanisms that mediate OTA toxicity on WI-38 cells. BAX downregulation, reduced BAX/BCL-2 ratio together with miR-155 upregulation indicated either the inhibition of TP53-dependent apoptosis or a tissue specific response to OTA exposure. The aforementioned OTA-induced variations present a new molecular evidence of OTA cytotoxicity and possible carcinogenicity in lung fibroblast cells.


Sujet(s)
Épigenèse génétique , microARN , Ochratoxines , Humains , Protéine Bax , ADN , Méthylation de l'ADN , Fibroblastes , Poumon , Ochratoxines/toxicité , Protéines proto-oncogènes c-bcl-2
16.
Toxicon ; 236: 107327, 2023 Dec.
Article de Anglais | MEDLINE | ID: mdl-37863437

RÉSUMÉ

Atrazine, a herbicide, is used for eradication of broad-leaved herbs in corn crop; and ochratoxins, particularly ochratoxin A (OTA), are major pollutants of poultry diet. Existence of both of these hazardous chemicals as residues is obvious as elucidated by various epidemiological findings. The present study was designed to investigate toxicopathological, serum biochemical and immunological alterations incurred by atrazine alone and/or, in combination with OTA in broilers. For this purpose, one-day old broiler chicks (n = 180) were purchased from a local hatching unit and were fed two levels of atrazine (50 and 150 mg/kg) and one level of OTA (100 µg/kg) in different combinations. Results of this experiment showed a significant reduction in feed intake, body weight gain, relative organ weights, serum total protein, albumin and globulin while there was a significant increase in urea and creatinine levels, decreased antibody response to sheep red blood cells, reduced lymphoproliferative response and phagocytic capacity in groups given OTA and atrazine individually in feed and these effects became more pronounced when atrazine was given in combination with OTA suggesting synergistic effects of both toxicants for each other.


Sujet(s)
Atrazine , Ochratoxines , Animaux , Ovis , Ochratoxines/toxicité , Poulets , Atrazine/toxicité , Aliment pour animaux/analyse
17.
Pestic Biochem Physiol ; 195: 105556, 2023 Sep.
Article de Anglais | MEDLINE | ID: mdl-37666592

RÉSUMÉ

Azoxystrobin (AZO) is a broad-spectrum strobilurin fungicide widely used in agriculture. However, its use increases the possibility of co-occurrence with mycotoxins such as ochratoxin A (OTA), which poses a significant risk to human health. Therefore, it is imperative to prioritize the evaluation of the combined toxicity of these two compounds. To assess the combined effects of AZO and OTA, the response genes and phenotypes for AZO or OTA exposure were obtained by utilizing Comparative Toxicogenomics Database, and Database for Annotation, Visualization and Integrated Discovery was used for GO and KEGG pathway enrichment analysis. In addition, we provided in-vivo evidence that AZO and OTA, in isolation and combination, could disrupt a variety of biological processes, such as oxidative stress, inflammatory response, apoptosis and thyroid hormone regulation under environmentally relevant concentrations. Notably, our findings suggest that the combined exposure group exhibited greater toxicity, as evidenced by the expression of various markers associated with the aforementioned biological processes, compared to the individual exposure group, which presents potential targets for the underlying mechanisms of induced toxicity. This study provides a novel methodological approach for exploring the mechanism of combined toxicity of a fungicide and a mycotoxin, which can shed light for conducting risk assessment of foodborne toxins.


Sujet(s)
Fongicides industriels , Ochratoxines , Humains , Strobilurines , Fongicides industriels/toxicité , Ochratoxines/toxicité
18.
Toxicology ; 497-498: 153630, 2023 10.
Article de Anglais | MEDLINE | ID: mdl-37709162

RÉSUMÉ

Data from epidemiological and experimental studies have evidenced that some chemical contaminants in food elicit their harmful effects by targeting the central nervous system. Ochratoxin A is a foodborne mycotoxin produced by Aspergillus and Penicillium species. Research on neurotoxicity associated with ochratoxin A exposure has increased greatly in recent years. The present review accrued substantial evidence on the neurotoxicity associated with ochratoxin A exposure as well as discussed notable susceptible targets of noxious ochratoxin A at molecular, cellular and genetic levels. Specifically, the neurotoxic mechanisms associated with ochratoxin A exposure were unequivocally unraveled in vitro using human neuroblastoma SH-SY5Y cells, mouse hippocampal HT22 cells, human astrocyte (NHA-SV40LT) cells and microglia cells as well as in vivo using mammalian and non-mammalian models. Data from human biomonitoring studies on plasma ochratoxin A levels in patients with neurodegenerative diseases with some age- and sex-related responses were also highlighted. Moreover, the neurotherapeutic mechanisms of some naturally occurring bioactive compounds against ochratoxin A neurotoxicity are reviewed. Collectively, accumulated data from literature demonstrate that ochratoxin A is a neurotoxin with potential pathological involvement in neurological disorders. Cutting edge original translational research on the development of neurotherapeutics for neurotoxicity associated with foodborne toxicants including ochratoxin A is indispensable.


Sujet(s)
Mycotoxines , Neuroblastome , Syndromes neurotoxiques , Ochratoxines , Humains , Souris , Animaux , Ochratoxines/toxicité , Mycotoxines/toxicité , Syndromes neurotoxiques/étiologie , Mammifères
19.
Toxins (Basel) ; 15(9)2023 09 08.
Article de Anglais | MEDLINE | ID: mdl-37755991

RÉSUMÉ

Ochratoxins are the secondary metabolites of Penicillium and Aspergillus, among which ochratoxin A (OTA) is the most toxic molecule. OTA is widely found in food and agricultural products. Due to its severe nephrotoxicity, immunotoxicity, neurotoxicity, and teratogenic mutagenesis, it is essential to develop effective, economical, and environmentally friendly methods for OTA decontamination and detoxification. This review mainly summarizes the application of technology in OTA prevention, removal, and detoxification from physical, chemical, and biological aspects, depending on the properties of OTA, and describes the advantages and disadvantages of each method from an objective perspective. Overall, biological methods have the greatest potential to degrade OTA. This review provides some ideas for searching for new strains and degrading enzymes.


Sujet(s)
Ochratoxines , Ochratoxines/toxicité , Agriculture , Aliments , Mutagenèse
20.
Molecules ; 28(18)2023 Sep 14.
Article de Anglais | MEDLINE | ID: mdl-37764392

RÉSUMÉ

Ochratoxin A (OTA) is considered as the most toxic of the other ochratoxins synthesized by various fungal species belonging to the Aspergillus and Penicillium families. OTA commonly contaminates food and beverages, resulting in animal and human health issues. The toxicity of OTA is known to cause liver damage and is still being researched. However, current findings do not provide clear insights into the toxin mechanism of action. The current studies focusing on the use of potentially protective compounds against the effects of the toxin are insufficient as they are mainly conducted on animals. Further research is required to fill the existing gaps in both fields (namely the exact OTA molecular mechanism and the prevention of its toxicity in the human liver). This review article is a summary of the so far obtained results of studies focusing on the OTA hepatotoxicity, its mode of action, and the known approaches of liver cells protection, which may be the base for expanding other research in near future.


Sujet(s)
Lésions hépatiques dues aux substances , Ochratoxines , Animaux , Humains , Ochratoxines/toxicité , Boissons , Aliments , Lésions hépatiques dues aux substances/étiologie , Lésions hépatiques dues aux substances/prévention et contrôle
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