Binary and tertiary combination of alternariol, 3-acetyl-deoxynivalenol and 15-acetyl-deoxynivalenol on HepG2 cells: Toxic effects and evaluation of degradation products

Daphnia magna model for the study of mycotoxins present in food: Gliotoxin, ochratoxin A and its combination

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.

Combined in vitro and in silico mechanistic approach to explore the potential of Alternaria mycotoxins alternariol and altertoxin II to hamper γH2AX formation in DNA damage signaling pathways

Risk assessment of food and environmental contaminants is faced by substantial data gaps and novel strategies are needed to support science-based regulatory actions. The Alternaria mycotoxins alternariol (AOH) and altertoxin II (ATXII) have garnered attention for their possible genotoxic effects. Nevertheless, data currently available are rather scattered, hindering a comprehensive hazard characterization. This study combined in vitro/in silico approaches to elucidate the potential of AOH and ATXII to induce double-strand breaks (DSBs) in HepG2 cells. Furthermore, it examines the impact of co-exposure to AOH and the DSB-inducing drug doxorubicin (Doxo) on γH2AX expression. AOH slightly increased γH2AX expression, whereas ATXII did not elicit this response. Interestingly, AOH suppressed Doxo-induced γH2AX expression, despite evidence of increased DNA damage in the comet assay. Building on these observations, AOH was postulated to inhibit γH2AX-forming kinases. Along this line, in silico analysis supported AOH potential interaction with the ATP-binding sites of these kinases and immunofluorescence experiments showed decreased intracellular phosphorylation events. Similarly, in silico results suggested that ATXII might also interact with these kinases. This study emphasizes the importance of understanding the implications of AOH-induced γH2AX expression inhibition on DNA repair processes and underscores the need for caution when interpreting γH2AX assay results.

Hazard characterization of Alternaria toxins to identify data gaps and improve risk assessment for human health

Fungi of the genus Alternaria are ubiquitous plant pathogens and saprophytes which are able to grow under varying temperature and moisture conditions as well as on a large range of substrates. A spectrum of structurally diverse secondary metabolites with toxic potential has been identified, but occurrence and relative proportion of the different metabolites in complex mixtures depend on strain, substrate, and growth conditions. This review compiles the available knowledge on hazard identification and characterization of Alternaria toxins. Alternariol (AOH), its monomethylether AME and the perylene quinones altertoxin I (ATX-I), ATX-II, ATX-III, alterperylenol (ALP), and stemphyltoxin III (STTX-III) showed in vitro genotoxic and mutagenic properties. Of all identified Alternaria toxins, the epoxide-bearing analogs ATX-II, ATX-III, and STTX-III show the highest cytotoxic, genotoxic, and mutagenic potential in vitro. Under hormone-sensitive conditions, AOH and AME act as moderate xenoestrogens, but in silico modeling predicts further Alternaria toxins as potential estrogenic factors. Recent studies indicate also an immunosuppressive role of AOH and ATX-II; however, no data are available for the majority of Alternaria toxins. Overall, hazard characterization of Alternaria toxins focused, so far, primarily on the commercially available dibenzo-α-pyrones AOH and AME and tenuazonic acid (TeA). Limited data sets are available for altersetin (ALS), altenuene (ALT), and tentoxin (TEN). The occurrence and toxicological relevance of perylene quinone-based Alternaria toxins still remain to be fully elucidated. We identified data gaps on hazard identification and characterization crucial to improve risk assessment of Alternaria mycotoxins for consumers and occupationally exposed workers.

Recalling the reported toxicity assessment of deoxynivalenol, mitigating strategies and its toxicity mechanisms: Comprehensive review

Mycotoxins frequently contaminate a variety of food items, posing significant concerns for both food safety and public health. The adverse consequences linked to poisoning from these substances encompass symptoms such as vomiting, loss of appetite, diarrhea, the potential for cancer development, impairments to the immune system, disruptions in neuroendocrine function, genetic damage, and, in severe cases, fatality. The deoxynivalenol (DON) raises significant concerns for both food safety and human health, particularly due to its potential harm to vital organs in the body. It is one of the most prevalent fungal contaminants found in edible items used by humans and animals globally. The presence of harmful mycotoxins, including DON, in food has caused widespread worry. Altered versions of DON have arisen as possible risks to the environment and well-being, as they exhibit a greater propensity to revert back to the original mycotoxins. This can result in the buildup of mycotoxins in both animals and humans, underscoring the pressing requirement for additional investigation into the adverse consequences of these modified mycotoxins. Furthermore, due to the lack of sufficient safety data, accurately evaluating the risk posed by modified mycotoxins remains challenging. Our review study delves into conjugated forms of DON, exploring its structure, toxicity, control strategies, and a novel animal model for assessing its toxicity. Various toxicities, such as acute, sub-acute, chronic, and cellular, are proposed as potential mechanisms contributing to the toxicity of conjugated forms of DON. Additionally, the study offers an overview of DON's toxicity mechanisms and discusses its widespread presence worldwide. A thorough exploration of the health risk evaluation associated with conjugated form of DON is also provided in this discussion.

Individual and combined effect of acrylamide, fumitremorgin C and penitrem A on human neuroblastoma SH-SY5Y cells

Acrylamide (AA) is a chemical compound that can be formed in certain foods during high-temperature cooking processes such as frying, baking, and roasting. Exposure to AA has been linked to several neurological effects, including peripheral neuropathy, ataxia, and impaired cognitive function. Penitrem A (PEN A) and Fumitremorgin C (FTC) are toxic mycotoxins produced by certain species of fungi, such as Penicillium Crustosum, Aspergillus Fumigatus and Neosartorya Fischeri. Both mycotoxins are commonly found in contaminated foods and animal feeds and have been linked to several adverse health effects in humans and animals, including the ability to disrupt normal functioning of the nervous system, tremors, seizures, muscle spasms, and convulsions. AA, PEN A, and FTC are all chemical contaminants. Understanding their toxicity and how they may affect human cells can help food safety authorities to establish safe exposure levels for these compounds through food and develop strategies to reduce their presence. The aim of this study was to explore the combined in vitro toxicological effects of AA, PEN A and FTC in SH-SY5Y cells. For this purpose, cells were treated with AA, FTC, and PEN A as an individual and combined treatment. The types of interactions were assessed by the isobologram analysis. The cell cycle was performed by flow cytometry. Additive effect in binary and tertiary combinations was the major effect according to isobologram graphics. Our results demonstrate that PEN A possessed the highest potential in disturbing cell cycle progression by disrupting cell density in G0/G1 phase.

Toxic effects of the cylindrospermopsin and chlorpyrifos combination on the differentiated SH-SY5Y human neuroblastoma cell line

Due to climate change and anthropogenic activities, the levels of pollution of aquatic and terrestrial environments have increased in the last decades. In this sense, the rise of cyanobacterial blooms, which release secondary metabolites with toxic properties, and the global use of pesticides for agricultural purposes have a negative impact on ecosystems. Thus, it would be interesting to study the concomitance of both types of toxicants in the same sample, since it is possible that they appear together. The aim of the present work was to state the effects of the interaction between the cyanotoxin cylindrospermopsin and the pesticide chlorpyrifos in differentiated SH-SY5Y neuronal cells to assess how they could affect the nervous system. To this end, cytotoxicity, morphological, and acetylcholinesterase activity studies were performed during 24 and 48 h. The results revealed a concentration-dependent decrease in viability and interaction between both toxicants, together with clear signs of apoptosis and necrosis induction. In this sense, different stages on the differentiation process would lead to differences in the toxicity exerted by the compounds both isolated as in combination, which it is not observed in non-differentiated cells. Additionally, the acetylcholinesterase activity appeared not to be affected, which is a clear difference compared to non-differentiated cells. These results show the importance of studying not only the toxicants themselves, but also in combination, to assess their possible effects in a more realistic scenario.

Effectiveness of beetroot extract in SH-SY5Y neuronal cell protection against Fumonisin B1, Ochratoxin A and its combination

Fumonisin B1 (FB1) and ochratoxin A (OTA) are fungal metabolites of worldwide concern because of their effect on human and animal health, as both have been classified by IARC as possible carcinogens (Group 2B). Beetroot is a source of dietary fiber, folic acid, and vitamin C, and some studies have demonstrated their antioxidant activity. Therefore, this work presents the cytoprotective effect of beetroot extract (BRE) on a neuroblastoma cell line (SH-SY5Y cells) exposed to FB1, OTA, and its combination. Cytotoxicity was studied by the MTT ([3-4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay, for 24 h and 48 h. Simultaneous treatment and pre-treatment strategies were tested with 1:512-1:2 and 1:0 dilutions of BRE, with a concentration range from 0.4 to 100 μM of FB1 and from 0.19 to 50 μM of OTA. IC₅₀ values of 5.8 μM and 9.1 μM at 24 h and 48 h, respectively were obtained for OTA while no cytotoxic effect was detected at the concentrations tested for FB1. Cytoprotection with increased viability was obtained when the simultaneous BRE + OTA strategy was performed. Finally, better protection was observed in the pretreatment strategy in which cells were exposed 24 h previously to BRE, compared to that shown in the simultaneous assay.

Cytotoxic Effects of Alternariol, Alternariol Monomethyl-Ether, and Tenuazonic Acid and Their Relevant Combined Mixtures on Human Enterocytes and Hepatocytes

Alternariol (AOH), alternariol monomethyl-ether (AME), and tenuazonic acid (TeA) are major mycotoxins produced by fungi of the genus Alternaria and are common contaminants of food products such as fruits, vegetables, cereals and grains. Alternaria mycotoxins are known to cause relevant economic losses and to have a negative impact on human and animal health. EFSA stated in its scientific opinion that data on the toxicity of Alternaria mycotoxins in humans and livestock are generally lacking, precluding proper hazard characterization. This study aimed to fill some knowledge gaps by studying the in vitro cytotoxicity toward human intestinal epithelial cells (Caco-2) and hepatocytes (HepG2). Cytotoxic properties were assessed by flow cytometric analyses of remaining viable cells (i.e., propidium iodide negative) after mycotoxin exposure for 24-48 h versus solvent control. Treatment of cells with single doses of AOH, AME, and TeA resulted in a dose-dependent loss of cell viability for both cell lines. Half maximal effective concentrations (EC50) of the different mycotoxins were comparable for the two cell lines. On HepG2 cells, EC50 values varying between 8 and 16, 4 and 5, and 40 and 95 μg/mL were calculated for AOH, AME, and TeA, respectively. On Caco-2 cells, EC50 values of 19 μg/mL and varying between 6 and 23, and 60 and 90 μg/mL were calculated for AOH, AME, and TeA, respectively. A general relative cytotoxicity ranking of about 1 = 1 >>> 3 was obtained for AOH, AME, and TeA, respectively. Treatment of both cell lines with combined binary and ternary mixtures of AOH, AME, and TeA in a 1:1:3 ratio, also showed a dose-dependent decrease in cell viability. For both cell lines, the binary combination of especially AME and TeA (1:3 ratio) but also of AOH and AME (1:1 ratio) significantly increased the cytotoxicity compared to the single compound toxicity, although mainly at the highest concentrations tested. The ternary combinations of AOH, AME, and TeA induced only a slight increase in cytotoxicity compared to the single mycotoxins, again at the highest concentrations tested.

Multimycotoxin Analysis in Oat, Rice, Almond and Soy Beverages by Liquid Chromatography-Tandem Mass Spectrometry

This study developed and validated an analytical methodology for the determination of aflatoxins, enniatins, beauvericin, zearalenone, ochratoxin-A, alternariols, HT-2 and T-2 toxin in soy, oat, rice and almond beverages, based on solid phase extraction columns (SPE) and analyzed by liquid chromatography coupled to mass spectrometry in tandem. C18 SPE was successfully applied, obtaining recoveries that range from 72 ± 12% (ochratoxin-A) to 99 ± 4% (ENA1) at high level (L1) and 65 ± 8% (T-2) to 128 ± 9% (alternariol monomethyl ether) at low levels (L3). The methodology was validated according to Commission Decision 2002/657/EC, with limits of quantification ranging from 0.3 (AFs in oat beverages) to 18 ng/mL (HT-2 in rice beverage). The analysis of 56 beverage samples purchased from Valencia (Spain) showed at least one mycotoxin occurring in 95% of samples, including carcinogenic aflatoxins, and oat beverage was the most contaminated. This is a newest validated methodology for the quantification of sixty mycotoxins in oat, rice, almond and soy beverages.

Structure-toxicity relationships, toxicity mechanisms and health risk assessment of food-borne modified deoxynivalenol and zearalenone: A comprehensive review

Mycotoxin, as one of the most common pollutants in foodstuffs, poses great threat to food security and human health. Specifically, deoxynivalenol (DON) and zearalenone (ZEN)-two mycotoxin contaminants with considerable toxicity widely existing in food products-have aroused broad public concerns. Adding to this picture, modified forms of DON and ZEN, have emerged as another potential environmental and health threat, owing to their higher re-transformation rate into parent mycotoxins inducing accumulation of mycotoxin in humans and animals. Given this, a better understanding of the toxicity of modified mycotoxins is urgently needed. Moreover, the lack of toxicity data means a proper risk assessment of modified mycotoxins remains challenging. To better evaluate the toxicity of modified DON and ZEN, we have reviewed the relationship between their structures and toxicities. The toxicity mechanisms behind modified DON and ZEN have also been discussed; briefly, these involve acute, subacute, chronic, and combined toxicities. In addition, this review also addresses the global occurrence of modified DON and ZEN, and summarizes novel methods-including in silico analysis and implementation of relative potency factors-for risk assessment of modified DON and ZEN. Finally, the health risk assessment of modified DON and ZEN has also been discussed comprehensively.

Updated Review of the Toxicity of Selected Fusarium Toxins and Their Modified Forms

Mycotoxins are one of the most dangerous food and feed contaminants, hence they have significant influence on human and animal health. This study reviews the information reported over the last few years on the toxic effects of the most relevant and studied Fusarium toxins and their modified forms. Deoxynivalenol (DON) and its metabolites can induce intracellular oxidative stress, resulting in DNA damage. Recent studies have also revealed the capability of DON and its metabolites to disturb the cell cycle and alter amino acid expression. Several studies have attempted to explore the mechanism of action of T-2 and HT-2 toxins in anorexia induction. Among other findings, two neurotransmitters associated with this process have been identified, namely substance P and serotonin (5-hydroxytryptamine). For zearalenone (ZEN) and its metabolites, the literature points out that, in addition to their generally acknowledged estrogenic and oxidative potentials, they can also modify DNA by altering methylation patterns and histone acetylation. The ability of the compounds to induce alterations in the expression of major metabolic genes suggests that these compounds can contribute to the development of numerous metabolic diseases, including type 2 diabetes.

Study of locomotion response and development in zebrafish (Danio rerio) embryos and larvae exposed to enniatin A, enniatin B, and beauvericin

Mycotoxins are secondary metabolites produced by a variety of fungi that contaminate food and feed resources, and are capable of inducing a wide range of toxicity. Here, we studied the developmental and behavioral toxicity in zebrafish (Danio rerio) embryos and larvae exposed to three mycotoxins: beauvericin (BEA), Enniatin A (ENN A), and Ennitain B (ENN B). Zebrafish embryos were collected after fertilization, treated individually from 1 to 6 dpf with BEA at 8, 16, 32 and, 64 μM and for both enniatins at 3.12, 6.25, 12.5 and, 25 μM. Mixture of mycotoxins were assayed as follows: i) for BEA + ENN A and BEA + ENN B at [32 + 12.5] μM and [16 + 6.25] μM; ii) for ENN A + ENN B at [12.5 + 12.5] μM and [6.25 + 6.25] μM and, iii) for BEA + ENN A + ENN B at [32 + 12.5 + 12.5] μM and [16 + 6.25 + 6.25] μM. Response was collected after a white light-flash intermittent coming on for 5 s during 2 h with a imaging platform. Outcomes measured were: time to death, response to light, and circadian rhythm. This last outcome was measured in a plate where embryos had evolved in natural intervals of light and dark until day 7 or in a plate maintained in darkness. Images of all stages and evolution were collected. Results indicated that mycotoxins induced toxicity at the concentrations tested. All exposed zebrafish induced developmental defects, specifically hatching time and motion activity. After exposure, fish showed enhanced baseline activity but they lost their responsiveness to light.

Multi-mycotoxin contamination of green tea infusion and dietary exposure assessment in Moroccan population

Green tea infusion is one of the most widely drunk beverages worldwide due to its health benefits associated with microelements, essential oils, and polyphenols, etc. Several studies have reported that green tea is subjected to contamination by various toxigenic fungi. Thus, this work aims to investigate the co-occurrence of 15 mycotoxins [four aflatoxins (AFB1, AFB2, AFG1, AFG2), ochratoxin A (OTA), beauvericin (BEA), four enniatins (ENA, ENA1, ENB, ENB1), zearalenone (ZEN), alternariol (AOH), tentoxin (TENT), T-2 and HT-2 toxins] in green tea samples available in Morocco by liquid chromatography tandem mass spectrometry method. Analytical and consumption data were then used to assess the dietary exposure for the population. Out of 111 total green tea samples, 62 (56%) were contaminated by at least one mycotoxin. The most found mycotoxins in samples were AOH (40%), ZEN (35%), AFG1 (2%), AFB2 (2%), ENB (2%) and TENT (1%). The highest level was found for ZEN with 45.8 ng/g. There is no sample that exceeded the recommended levels set by European Pharmacopoeia for certain mycotoxins in plant material. Although multi-mycotoxin co-occurred in samples (33%), the probable estimated daily intake values show that the intake of mycotoxins through the consumption of green tea does not represent a risk for the population.

In silico methods for metabolomic and toxicity prediction of zearalenone, α-zearalenone and β-zearalenone

Zearalenone (ZEA), α-zearalenol (α-ZEL) and β-zearalenol (β-ZEL) (ZEA's metabolites) are co/present in cereals, fruits or their products. All three with other compounds, constitute a cocktail-mixture that consumers (and also animals) are exposed and never entirely evaluated, nor in vitro nor in vivo. Effect of ZEA has been correlated to endocrine disruptor alterations as well as its metabolites (α-ZEL and β-ZEL); however, toxic effects associated to metabolites generated once ingested are unknown and difficult to study. The present study defines the metabolomics profile of all three mycotoxins (ZEA, α-ZEL and β-ZEL) and explores the prediction of their toxic effects proposing an in silico workflow by using three programs of predictions: MetaTox, SwissADME and PASS online. Metabolomic profile was also defined and toxic effect evaluated for all metabolite products from Phase I and II reaction (a total of 15 compounds). Results revealed that products describing metabolomics profile were: from O-glucuronidation (1z and 2z for ZEA and 1 ab, 2 ab and 3 ab for ZEA's metabolites), S-sulfation (3z and 4z for ZEA and 4 ab, 5 ab and 6 ab for ZEA's metabolites) and hydrolysis (5z and 7 ab for ZEA's metabolites, respectively). Lipinsky's rule-of-five was followed by all compounds except those coming from O-glucuronidation (HBA>10). Metabolite products had better properties to reach blood brain barrier than initial mycotoxins. According to Pa values (probability of activation) order of toxic effects studied was carcinogenicity > nephrotoxic > hepatotoxic > endocrine disruptor > mutagenic (AMES TEST) > genotoxic. Prediction of inhibition, induction and substrate function on different isoforms of Cytochrome P450 (CYP1A1, CYP1A2, CYP2C9 and CYP3A4) varied for each compounds analyzed; similarly, for activation of caspases 3 and 8. Relying to our findings, the metabolomics profile of ZEA, α-ZEL and β-ZEL analyzed by in silico programs predicts alteration of systems/pathways/mechanisms that ends up causing several toxic effects, giving an excellent sight and direct studies before starting in vitro or in vivo assays contributing to 3Rs principle; however, confirmation can be only demonstrated by performing those assays.

Chemoprotective effect of carotenoids from Lycium barbarum L. on SH-SY5Y neuroblastoma cells treated with beauvericin

Goji berry has recently been introduced in Mediterranean diet and its consumption is increasing. This study aims to determine cytoprotection of lutein (LUT), zeaxanthin (ZEAX) and goji berry extract (GBE) rich in carotenoids against Beauvericin (BEA)-induced cytotoxicity on SH-SY5Y neuroblastoma cells. Both carotenoids and GBE showed cytoprotective effects. Cytoprotection was evaluated by simultaneous combination of the two xanthophylls LUT and ZEAX with BEA, as well as using pre-treatment assays. The highest protective effect occurred in 16%, 24% and 12% respectively for LUT, ZEAX and LUT + ZEAX incubating simultaneously with BEA, while by pre-treatment assay LUT showed a cytoprotection effect over 30% and ZEAX alone or LUT + ZEAX promoted only a slight cytoprotection (<10%). Pre-treatment assays with GBE, showed a cytoprotection, between 3 and 20%, for BEA concentrations ranging from 0.1 to 6.25 μM, whereas no protective effect was observed when the cells were simultaneously incubated with GBE and BEA. Finally, by means of CI-isobologram method, the interaction between LUT, ZEAX and BEA were evaluated, and the results showed an synergism effect for almost all combinations tested. The data presented shows a option of using goji berries to potentially mitigate the toxicity of beauvericin eventually present in foods.

Individual and Combined Effect of Zearalenone Derivates and Beauvericin Mycotoxins on SH-SY5Y Cells

Beauvericin (BEA) and zearalenone derivatives, α-zearalenol (α-ZEL), and β-zearalenol (β-ZEL), are produced by several Fusarium species. Considering the impact of various mycotoxins on human's health, this study determined and evaluated the cytotoxic effect of individual, binary, and tertiary mycotoxin treatments consisting of α-ZEL, β-ZEL, and BEA at different concentrations over 24, 48, and 72 h on SH-SY5Y neuronal cells, by using the MTT assay (3-(4,5-dimethylthiazol-2-yl)-2,5diphenyltetrazoliumbromide). Subsequently, the isobologram method was applied to elucidate if the mixtures produced synergism, antagonism, or additive effects. Ultimately, we determined the amount of mycotoxin recovered from the media after treatment using liquid chromatography coupled with electrospray ionization-quadrupole time-of-flight mass spectrometry (LC-ESI-qTOF-MS). The IC50 values detected at all assayed times ranged from 95 to 0.2 μM for the individual treatments. The result indicated that β-ZEL was the most cytotoxic mycotoxin when tested individually. The major effect detected for all combinations assayed was synergism. Among the combinations assayed, α-ZEL + β-ZEL + BEA and α-ZEL + BEA presented the highest cytotoxic potential with respect to the IC value. At all assayed times, BEA was the mycotoxin recovered at the highest concentration in individual form, and β-ZEL + BEA was the combination recovered at the highest concentration.

Beauvericin and ochratoxin A mycotoxins individually and combined in HepG2 cells alter lipid peroxidation, levels of reactive oxygen species and glutathione

The co-presence of more than one mycotoxin in food is being evidenced in last food surveys as reported in the literature. Beauvericin (BEA) is a non-legislated emergent mycotoxin while Ochratoxin A (OTA) has been widely studied and legislated. Concentration range individually studied was from 2.5 to 0.3 μM for BEA and from 25 to 3.1 μM for OTA; binary mixture [BEA + OTA] comprised concentrations of 1:10 ratio from [2.5 + 25] to [3.1 + 0.3] μM. Potential of toxicity of BEA in HepG2 cells was the highest at all times assayed (24, 48 and 72h). LPO was performed through malondyaldehyde (MDA) detection denoting in the binary mixture for [1.25 + 12.5] μM and at 24 and 72h the highest disturbance values. ROS denoted differences respect to the control at different times specially for OTA, while in binary combination only for few point times was denoted. Effects detected for ROS and LPO were connected with alterations detected for glutathione levels of oxidized and reduced form. A real scenario of consumers chronically exposed to different mycotoxins and their mixtures is here presented highlighting the good methodology to assess the risk from exposure to combinations of chemicals in food.

Deoxynivalenol: toxicological profiles and perspective views for future research

Deoxynivalenol (DON) is a secondary metabolite mainly produced by the fungi Fusarium in agricultural crops, widely existing in feeds and cereal-based foodstuffs. Because of the high occurrence and potentials to induce a variety of toxic effects on animals and humans, DON has been a very harmful exogenous dietary toxicant threating public health. The focus of this review is to summarise the DON-induced broad spectrum of adverse health effects, to probe the current state of knowledge of combined toxicity of DON with other mycotoxins and its derivatives, and to put forward prospective ideas that multi-generational toxicity of DON and its overall impacts on intestinal-immuno-neuroendocrine system could receive more attention in future investigations. The general aim is to provide a scientific basis for the necessity to re-consider risk-assessment and regulations.

Assessing the Effect of Mycotoxin Combinations: Which Mathematical Model Is (the Most) Appropriate?

In the past decades, many studies have examined the nature of the interaction between mycotoxins in biological models classifying interaction effects as antagonisms, additive effects, or synergisms based on a comparison of the observed effect with the expected effect of combination. Among several described mathematical models, the arithmetic definition of additivity and factorial analysis of variance were the most commonly used in mycotoxicology. These models are incorrectly based on the assumption that mycotoxin dose-effect curves are linear. More appropriate mathematical models for assessing mycotoxin interactions include Bliss independence, Loewe’s additivity law, combination index, and isobologram analysis, Chou-Talalays median-effect approach, response surface, code for the identification of synergism numerically efficient (CISNE) and MixLow method. However, it seems that neither model is ideal. This review discusses the advantages and disadvantages of these mathematical models.

Co-Occurrence and Combinatory Effects of Alternaria Mycotoxins and other Xenobiotics of Food Origin: Current Scenario and Future Perspectives

Mycotoxins are low-molecular weight compounds produced by diverse genera of molds that may contaminate food and feed threatening the health of humans and animals. Recent findings underline the importance of studying the combined occurrence of multiple mycotoxins and the relevance of assessing the toxicity their simultaneous exposure may cause in living organisms. In this context, for the first time, this work has critically reviewed the most relevant data concerning the occurrence and toxicity of mycotoxins produced by Alternaria spp., which are among the most important emerging risks to be assessed in food safety, alone or in combination with other mycotoxins and bioactive food constituents. According to the literature covered, multiple Alternaria mycotoxins may often occur simultaneously in contaminated food, along with several other mycotoxins and food bioactives inherently present in the studied matrices. Although the toxicity of combinations naturally found in food has been rarely assessed experimentally, the data collected so far, clearly point out that chemical mixtures may differ in their toxicity compared to the effect of toxins tested individually. The data presented here may provide a solid foothold to better support the risk assessment of Alternaria mycotoxins highlighting the actual role of chemical mixtures on influencing their toxicity.

Cytotoxicity, Genotoxicity and Disturbance of Cell Cycle in HepG2 Cells Exposed to OTA and BEA: Single and Combined Actions

Mycotoxins are produced by a number of fungal genera spp., for example, Aspergillus, Penicillium, Alternaria, Fusarium, and Claviceps. Beauvericin (BEA) and Ochratoxin A (OTA) are present in various cereal crops and processed grains. This goal of this study was to determine their combination effect in HepG2 cells, presented for the first time. In this study, the type of interaction among BEA and OTA through an isobologram method, cell cycle disturbance by flow cytometry, and genotoxic potential by in vitro micronucleus (MN) assay following the TG 487 (OECD, 2016) of BEA and OTA individually and combined in HepG2 cells are presented. Cytotoxic concentration ranges studied by the MTT assay over 24, 48, and 72 h were from 0 to 25 µM for BEA and from 0 to 100 µM for OTA, while BEA + OTA combinations were at a 1:10 ratio from 3.4 to 27.5 µM. The toxicity observed for BEA was higher than for OTA at all times assayed; additive and synergistic effects were detected for their mixtures. Cell cycle arrest in the G0/G1 phase was detected for OTA and BEA + OTA treatments in HepG2 cells. Genotoxicity revealed significant effects for BEA, OTA, and in combinations underlining the importance of studying real exposure scenarios of chronic exposure to mycotoxins.

Effects of deoxynivalenol, 3-acetyl-deoxynivalenol and 15-acetyl-deoxynivalenol on parameters associated with oxidative stress in HepG2 cells

This work studied the effect of deoxynivalenol (DON) and two of its acetylated analogs (3-ADON, 15-ADON) on first indicators of oxidative stress status, namely production of reactive oxygen species (ROS) and induction of lipid peroxidation (LPO), in HepG2 cells. HepG2 cells were exposed to different concentrations of the three toxins, either alone or in combinations, for 24, 48, and 72 h. Results of cytotoxicity obtained in HepG2 cells were correlated with the detection of ROS and LPO. This effect was inversely correlated with ROS while directly correlated with LPO for the assayed mycotoxins in individual treatment. Combinations of two toxins containing 15-ADON yielded highest values, while for two-toxin combinations with 3-ADON, the effects were minor. A combination of all three mycotoxins alleviated ROS production and the highest levels in LPO were detected, in association to a final breakdown of adaption of ROS early produced by HepG2. In conclusion, parameters of stress evaluation presented in this study (ROS and LPO), revealed increases in HepG2 cells exposed to DON, 3-ADON, and 15-ADON either individually or combined.

Photocatalytic degradation of deoxynivalenol over dendritic-like α-Fe₂O₃ under visible light irradiation

Deoxynivalenol (DON) is a secondary metabolite produced by Fusarium, which is a trichothecene mycotoxin. As the main mycotoxin with high toxicity, wheat, barley, corn and their products are susceptible to contamination of DON. Due to the stability of this mycotoxin, traditional methods for DON reduction often require a strong oxidant, high temperature and high pressure with more energy consumption. Therefore, exploring green, efficient and environmentally friendly ways to degrade or reduce DON is a meaningful and challenging issue. Herein, a dendritic-like α-Fe₂O₃ was successfully prepared using a facile hydrothermal synthesis method at 160 °C, which was systematically characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). It was found that dendritic-like α-Fe₂O₃ showed superior activity for the photocatalytic degradation of DON in aqueous solution under visible light irradiation (λ > 420 nm) and 90.3% DON (initial concentration of 4.0 μg/mL) could be reduced in 2 h. Most of all, the main possible intermediate products were proposed through high performance liquid chromatography-mass spectrometry (HPLC-MS) after the photocatalytic treatment. This work not only provides a green and promising way to mitigate mycotoxin contamination but also may present useful information for future studies.

In vitro characterization of hepatic toxicity of Alternaria toxins

Alternaria mycotoxins are secondary fungal metabolites which can contaminate food and feed. They are produced by Alternaria species with alternariol (AOH), alternariol monomethyl ether (AME), tenuazonic acid (TeA), and tentoxin (TEN) as the main representatives for Alternaria mycotoxins in food. Once passing the intestinal barrier, Alternaria toxins can reach the liver to exert yet uncharacterized molecular effects. Therefore, hepatic in vitro systems were used to examine selected Alternaria mycotoxins for their induction of metabolism-dependent cytotoxicity, phosphorylation of the histone H2AX as a surrogate marker for DNA double-strand breaks, and relevant marker genes for hepatotoxicity. Analysis of cell viability as well as the induction of H2AX phosphorylation in the hepatocarcinoma cell line HepG2 revealed a detoxification of 100 μmol/l AME and AOH by pre-treatment with S9 liver homogenate as shown by a decrease in cytotoxicity and H2AX histone phosphorylation to levels observed in control cells. Concentrations up to 100 μmol/l TeA and TEN did not induce H2AX phosphorylation whether metabolized or not. In the metabolically competent human hepatoma cell line HepaRG, no cytotoxicity of Alternaria toxins occurred even at high concentrations up to 100 μmol/l, which indicates a low cytotoxic potential. Induction of gene expression associated with liver toxicity was analyzed by quantitative real-time PCR using a specific hepatotoxicity PCR array in HepaRG cells: here, an evidence was found that 50 μmol/l of AOH, AME, TeA, and TEN might be associated with hepatotoxic effects, necrosis, and the development of diseases like cholestasis and phospholipidosis.

Micronucleus induction and cell cycle alterations produced by deoxynivalenol and its acetylated derivatives in individual and combined exposure on HepG2 cells

Mycotoxins are produced by a number of fungal genera spp as e.g. Aspergillus, Penicillium, Alternaria, Fusarium and Claviceps. 3-Acetyl-Deoxynivalenol (3-A-DON) and 15-Acetyl-Deoxynivalenol (15-ADON) which are produced by Fusarium, chemically belong to trichothecenes and occur in significant amounts as modified forms of deoxynivalenol (DON) in various cereal crops and processed grains. This study aims to determine the cytotoxicity, cell cycle and genotoxicity of the mycotoxins DON, 3-A-DON and 15-A-DON on HepG2 cells. Cytotoxic concentration range studied was from 100 to 3.1 μM for DON and 12.5 to 0.04 μM for 3-A-DON and 15-A-DON by the Neutral Red (NR) assay, over 24, 48 and 72 h. Potential of toxicity of 3-ADON in HepG2 cells was the highest at all times assayed. Cell cycle arrest in G0/G1 and G2/M phase was detected for all mycotoxins either in individually or in combined treatment in HepG2 cells. Genotoxicity was performed through micronuclei (MN) induction (TG 487) revealing significant effects for 3-ADON mycotoxin and in several combinations. It was evidenced that cell cycle alterations detected were associated to MN induction at all doses assayed, reaching the highest induction in tertiary combinations and in the binary combination 3-ADON + 15-ADON.

Analysis of the interactions between environmental and food contaminants, cadmium and deoxynivalenol, in different target organs

Cadmium (Cd), a common and widespread toxic heavy metal, and mycotoxins such as deoxynivalenol (DON) are frequent contaminants of the food supply. Most of the data on their toxicity concern their effects when present alone. However, consumers can be exposed to a cocktail of DON and Cd. To improve the understanding of their combined toxicity, the effects of DON and Cd alone or in combination were investigated in different human cell lines from the kidney (HEK-293), intestine (Caco-2), blood (HL-60) and liver (HepG2). Cytotoxicity was assessed through ATP measurement and types of interactions determined by the Isobologram-Combination index method. HEK-293 cells were exposed to increasing doses of DON, Cd and their combination at different ratios (DON/Cd of 2/1; 1/1; 1/2 and 1/8). Regardless of the ratio, the type of interaction observed in HEK-293 cells ranged from moderate antagonism to nearly additive with increasing cytotoxicity. In Caco-2 cells, the interactions ranged from nearly additive to antagonism whatever the ratio. At ratio 1/1, in HL-60 and HepG2 cells, interactions ranged from synergy to antagonism depending on the cytotoxicity level. Using human cells lines, this study indicates that the consequences of combined exposure to environmental and food contaminants are specific to the target organ. Further studies are needed to confirm these data in vivo.

Individual and combined effects of Aflatoxin B1, Deoxynivalenol and Zearalenone on HepG2 and RAW 264.7 cell lines

To understand the combinatorial toxicity of mycotoxins, we measured the effects of individual, binary and tertiary combinations of Aflatoxin B₁ (AFB₁), Deoxynivalenol (DON) and Zearalenone (ZEN) on the cell viability and cellular perturbations of HepG2 and RAW 264.7 cells. The nature of mycotoxins interactions was assessed using mathematical modeling (Chou-Talalay). Mechanisms of cytotoxicity were studied using high content screening (HCS) that probed cytotoxicity responses, such as changes in intracellular reactive oxygen species (ROS), mitochondrial membrane potential (MMP), intracellular calcium ([Ca²⁺]_i) flux, and cell membrane damage. Our results showed that individual cytotoxicity of mycotoxins in a decreasing order was DON>AFB₁>ZEN. Varying combinations of mycotoxins at differing concentrations showed different types of interactions. Most of the mixtures showed increasing toxic effects-synergism and/or addition while antagonistic effects were observed with combination of AFB₁+ZEN. Generally, combination of mycotoxins showed significantly increased intracellular ROS production and [Ca²⁺]_i flux, and decreased MMP in both cell lines, showing that the synergistic and additive effects of mycotoxin combination originate from perturbations of multiple cellular functions. Additionally, this study demonstrated the applicability of HCS for gaining mechanistic understanding on the toxicity of individual as well as combinatorial mycotoxins, and also provided scientific bases for formulating regulatory policies.

Aflatoxin M1 cytotoxicity against human intestinal Caco-2 cells is enhanced in the presence of other mycotoxins

Aflatoxin M1 (AFM1), a class 2B human carcinogen, is the only mycotoxin with established maximum residue limits (MRLs) in milk. Toxicological data for other mycotoxins in baby food, containing cereals and milk, either in isolation or in combination with AFM1, are sparse. The aim of this study was to investigate the cytotoxicity of AFM1, ochratoxin A (OTA), zearalenone (ZEA), and α-zearalenol (α-ZOL), individually and in combinations, in human Caco-2 cells. The tetrazolium salt (MTT) assay demonstrated that (i) OTA and AFM1 had similar cytotoxicity, which was higher than that of ZEA and α-ZOL, after a 72 h exposure; and (ii) the quaternary combination had the highest cytotoxicity, followed by tertiary and binary combinations and individual mycotoxins. Isobologram analysis indicated that the presence of OTA, ZEA, and/or α-ZOL with AFM1 led to additive and synergistic cytotoxicity in most combinations. The cytotoxicity of OTA was similar to that of AFM1, suggesting that OTA in food poses a health risk to consumers. Furthermore, AFM1 cytotoxicity increased dramatically in the presence of OTA, ZEA, and/or α-ZOL (p < 0.01), indicating that the established MRLs for AFM1 should be re-evaluated considering its frequent co-occurrence with other mycotoxins in baby food which contains milk and cereals.