Analyses of biomarkers of exposure to nephrotoxic mycotoxins in a cohort of patients with renal tumours

Effect of Bioactive Ingredients on Urinary Excretion of Aflatoxin B1 and Ochratoxin A in Rats, as Measured by Liquid Chromatography with Fluorescence Detection

Aflatoxin B1 (AFB1) and ochratoxin A (OTA) are highly toxic mycotoxins present in food and feed, posing serious health risks to humans and animals. This study aimed to validate an efficient and cost-effective analytical method for quantifying AFB1 and OTA in rat urine using immunoaffinity column extraction and liquid chromatography with fluorescence detection (IAC-LC-FD). Additionally, the study evaluated the effect of incorporating fermented whey and pumpkin into the feed on the urinary excretion of these mycotoxins. The limits of detection and quantification were determined to be 0.1 µg/kg and 0.3 µg/kg, respectively, for both mycotoxins in feed, and 0.2 ng/mL and 0.6 ng/mL, respectively, in urine. The method demonstrated robust recovery rates ranging from 74% to 119% for both AFB1 and OTA in both matrices. In feed samples, the levels of AFB1 and OTA ranged from 4.3 to 5.2 µg/g and from 5.4 to 8.8 µg/g, respectively. This validated method was successfully applied to analyze 116 urine samples from rats collected during the fourth week of an in vivo trial. The results indicated that the addition of fermented whey and pumpkin to the feed influenced mycotoxin excretion in urine, with variations observed based on the sex of the rats, type of mycotoxin, and exposure dosage.

Occurrence of the two major regulated mycotoxins, ochratoxin A and fumonisin B1, in cereal and cereal-based products in Europe and toxicological effects: A review

Among cereal contaminants, mycotoxins are of concern due to their importance in terms of food and feed safety. The difficulty in establishing a diagnosis for mycotoxicosis relies on the fact that the effects are most often subclinical for chronic exposure and the most common scenario is multi-contamination by various toxins. Mycotoxin co-occurrence is a major food safety concern as additive or even synergic toxic impacts may occur, but also regarding current regulations as they mainly concern individual mycotoxin levels in specific foods and feed in the food chain. However, due to the large number of possible mycotoxin combinations, there is still limited knowledge on co-exposure toxicity data, which depends on several parameters. In this context, this systematic review aims to provide an overview of the toxic effects of two regulated mycotoxins, namely ochratoxin A and fumonisin B1. This review focused on the 2012-2022 period and analysed the occurrence in Europe of the selected mycotoxins in different food matrices (cereals and cereal-derived products), and their toxic impact, alone or in combination, on in vitro intestinal and hepatic human cells. To better understand and evaluate the associated risks, further research is needed using new approach methodologies (NAM), such as in vitro 3D models. KEY CONTRIBUTION: Cereals and their derived products are the most important food source for humans and feed for animals worldwide. This manuscript is a state of the art review of the literature over the last ten years on ochratoxin A and fumonisin B1 mycotoxins in these products in Europe as well as their toxicological effects, alone and in combination, on human cells. Future perspectives and some challenges regarding the assessment of toxicological effects of mycotoxins are also discussed.

Mycotoxins in Cereal-Based Products and Their Impacts on the Health of Humans, Livestock Animals and Pets

Cereal grains are the most important food staples for human beings and livestock animals. They can be processed into various types of food and feed products such as bread, pasta, breakfast cereals, cake, snacks, beer, complete feed, and pet foods. However, cereal grains are vulnerable to the contamination of soil microorganisms, particularly molds. The toxigenic fungi/molds not only cause quality deterioration and grain loss, but also produce toxic secondary metabolites, mycotoxins, which can cause acute toxicity, death, and chronic diseases such as cancer, immunity suppression, growth impairment, and neural tube defects in humans, livestock animals and pets. To protect human beings and animals from these health risks, many countries have established/adopted regulations to limit exposure to mycotoxins. The purpose of this review is to update the evidence regarding the occurrence and co-occurrence of mycotoxins in cereal grains and cereal-derived food and feed products and their health impacts on human beings, livestock animals and pets. The effort for safe food and feed supplies including prevention technologies, detoxification technologies/methods and up-to-date regulation limits of frequently detected mycotoxins in cereal grains for food and feed in major cereal-producing countries are also provided. Some important areas worthy of further investigation are proposed.

New perspectives in application of kidney biomarkers in mycotoxin induced nephrotoxicity, with a particular focus on domestic pigs

The gradual spread of Aspergilli worldwide is adding to the global shortage of food and is affecting its safe consumption. Aspergillus-derived mycotoxins, including aflatoxins and ochratoxin A, and fumonisins (members of the fusariotoxin group) can cause pathological damage to vital organs, including the kidney or liver. Although the kidney functions as the major excretory system in mammals, monitoring and screening for mycotoxin induced nephrotoxicity is only now a developmental area in the field of livestock feed toxicology. Currently the assessment of individual exposure to mycotoxins in man and animals is usually based on the analysis of toxin and/or metabolite contamination in the blood or urine. However, this requires selective and sensitive analytical methods (e.g., HPLC-MS/MS), which are time consuming and expensive. The toxicokinetic of mycotoxin metabolites is becoming better understood. Several kidney biomarkers are used successfully in drug development, however cost-efficient, and reliable kidney biomarkers are urgently needed for monitoring farm animals for early signs of kidney disease. β₂-microglobulin (β₂-MG) and N-acetyl-β-D-glucosaminidase (NAG) are the dominant biomarkers employed routinely in environmental toxicology research, while kidney injury molecule 1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) are also emerging as effective markers to identify mycotoxin induced nephropathy. Pigs are exposed to mycotoxins due to their cereal-based diet and are particularly susceptible to Aspergillus mycotoxins. In addition to commonly used diagnostic markers for nephrotoxicity including plasma creatinine, NAG, KIM-1 and NGAL can be used in pigs. In this review, the currently available techniques are summarized, which are used for screening mycotoxin induced nephrotoxicity in farm animals. Possible approaches are considered, which could be used to detect mycotoxin induced nephropathy.

Lactobacillus plantarum and Deoxynivalenol Detoxification: A Concise Review

ABSTRACT

Mycotoxins are toxic secondary fungal metabolites that contaminate feeds, and their levels remain stable during feed processing. The economic impact of mycotoxins on animal production happens mainly due to losses related to direct effects on animal health and trade losses related to grain rejection. Deoxynivalenol (DON) is a trichothecene mycotoxin that has contaminated approximately 60% of the grains worldwide. Ingestion of DON induces many toxic effects on human and animal health. Detoxification strategies to decrease DON levels in food and feeds include physical and chemical methods; however, they are not very effective when incorporated into the industrial production process. A valuable alternative to achieve this aim is the use of lactic acid bacteria. These bacteria can control fungal growth and thus overcome DON production or can detoxify the mycotoxin through adsorption and biotransformation. Some Lactobacillus spp. strains, such as Lactobacillus plantarum, have demonstrated preventive effects against DON toxicity in poultry and swine. This beneficial effect is associated with a binding capacity of lactic acid bacteria cell wall peptidoglycan with mycotoxins. Moreover, several antifungal compounds have been isolated from L. plantarum supernatants, including lactic, acetic, caproic, phenyl lactic, 3-hydroxylated fatty, and cyclic dipeptide acids. Biotransformation of DON by L. plantarum into other products is also hypothesized, but the mechanism remains unknown. In this concise review, we highlight the use of L. plantarum as an alternative approach to reduce DON levels and toxicity. Although the action mechanism of L. plantarum is still not fully understood, these bacteria are a safe, efficient, and low-cost strategy to reduce economic losses from mycotoxin contamination cases.

HIGHLIGHTS

Mycotoxin Exposure and Renal Cell Carcinoma Risk: An Association Study in the EPIC European Cohort

BACKGROUND

Mycotoxins have been suggested to contribute to a spectrum of adverse health effects in humans, including at low concentrations. The recognition of these food contaminants being carcinogenic, as co-occurring rather than as singularly present, has emerged from recent research. The aim of this study was to assess the potential associations of single and multiple mycotoxin exposures with renal cell carcinoma risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort.

METHODS

Food questionnaire data from the EPIC cohort were matched to mycotoxin food occurrence data compiled by the European Food Safety Authority (EFSA) from European Member States to assess long-term dietary mycotoxin exposures, and to associate these with the risk of renal cell carcinoma (RCC, n = 911 cases) in 450,112 EPIC participants. Potential confounding factors were taken into account. Analyses were conducted using Cox's proportional hazards regression models to compute hazard ratios (HRs) and 95% confidence intervals (95% CIs) with mycotoxin exposures expressed as µg/kg body weight/day.

RESULTS

Demographic characteristics differed between the RCC cases and non-cases for body mass index, age, alcohol intake at recruitment, and other dietary factors. In addition, the mycotoxin exposure distributions showed that a large proportion of the EPIC population was exposed to some of the main mycotoxins present in European foods such as deoxynivalenol (DON) and derivatives, fumonisins, Fusarium toxins, Alternaria toxins, and total mycotoxins. Nevertheless, no statistically significant associations were observed between the studied mycotoxins and mycotoxin groups, and the risk of RCC development.

CONCLUSIONS

These results show an absence of statistically significant associations between long-term dietary mycotoxin exposures and RCC risk. However, these results need to be validated in other cohorts and preferably using repeated dietary exposure measurements. In addition, more occurrence data of, e.g., citrinin and fumonisins in different food commodities and countries in the EFSA database are a prerequisite to establish a greater degree of certainty.

Biomonitoring of ochratoxin A, 2'R-ochratoxin A and citrinin in human blood serum from Switzerland

Biomonitoring of mycotoxins and their metabolites in biological fluids is increasingly used to assess human exposure. In this study, biomarkers of ochratoxin A (OTA) and citrinin (CIT) exposure were determined in a large number of serum samples from healthy blood donors in Switzerland. In 2019, 700 samples from different regions were obtained. From 240 donors, a second sample (taken 2-9 months later) was available for analysis. Moreover, 355 blood donor samples from 2005 from all regions in Switzerland and 151 additional samples from the southern Swiss region of Ticino from 2005 could be analysed.OTA, 2'R-ochratoxin A (2'R-OTA), ochratoxin alpha (OTα), CIT and dihydrocitrinone (DH-CIT) were analysed using validated targeted methods including precipitation and online SPE clean-up.OTA and 2'R-OTA were frequently detected (OTA in 99%; 2'R-OTA in 51% of the tested samples). The mean concentration in all positive samples was 0.4 ng/mL for OTA and 0.2 ng/mL for 2'R-OTA. OTα was not detected in any sample above the limit of quantification (LOQ). In contrast to OTA, CIT and DH-CIT were only quantifiable in 2% and 0.1% of the samples, respectively. No significant trend was observed between the samples from 2005 and the more recent samples, but OTA concentrations were usually higher in serum samples from the southern Swiss region of Ticino and in males compared to females.Our extensive data fit well within the framework of previously published values for the healthy adult European population.

Ochratoxin A as alarming health in livestock and human: A review on molecular interactions, mechanism of toxicity, detection, detoxification, and dietary prophylaxis

Ochratoxin A (OTA) is a toxic metabolite produced by Aspergillus and Penicillium fungi commonly found in raw plant sources and other feeds. This review comprises an extensive evaluation of the origin and proprieties of OTA, toxicokinetics, biotransformation, and toxicodynamics of ochratoxins. In in vitro and in vivo studies, the compatibility of OTA with oxidative stress is observed through the production of free radicals, resulting in genotoxicity and carcinogenicity. The OTA leads to nephrotoxicity as the chief target organ is the kidney. Other OTA excretion and absorption rates are observed, and the routes of elimination include faeces, urine, and breast milk. The alternations in the Phe moiety of OTA are the precursor for the amino acid alternation, bringing about Phe-hydroxylase and Phe-tRNA synthase, resulting in the complete dysfunction of cellular metabolism. Biodetoxification using specific microorganisms decreased the DNA damage, lipid peroxidation, and cytotoxicity. This review addressed the ability of antioxidants and the dietary components as prophylactic measures to encounter toxicity and demonstrated their capability to counteract the chronic exposure through supplementation as feed additives.

Removal of Ochratoxin A from Red Wine Using Alginate-PVA-L. plantarum (APLP) Complexes: A Preliminary Study

The presence of ochratoxin A (OTA) in wines is a problem mainly due to the health damage it can cause to frequent drinkers. A method for removing these toxic substances from wine is the use of lactic acid bacteria with mycotoxin-adsorption capacities; however, their use is limited since a matrix in which they can be immobilized, to remove them after use, is needed. In this study, L. plantarum (LP) was encapsulated in a polymeric matrix composed of polyvinyl alcohol (PVA) and alginate, forming alginate–PVA–LP (APLP) complexes. Then, these complexes were characterized, and assays of OTA and phenol removal from wines were performed. As a result, it was observed that the APLP complexes at a concentration of 0.5 g mL⁻¹ removed over 50% of the OTA without substantially affecting the concentration of total phenols. In addition, it was determined that the presence of L. plantarum directly affected the ability to adsorb OTA from wines and did not decrease the total phenols. In conclusion, an alginate–PVA matrix allows immobilizing LP, and the complexes formed are an alternative for removing ochratoxin from contaminated wines.

MicroRNA target-based network predicts androgen receptor-linked mycotoxin stress

Stress-responsive microRNAs (miRNAs) contribute to the regulation of cellular homeostasis or pathological processes, including carcinogenesis, by reprogramming target gene expression following human exposure to environmental or dietary xenobiotics. Herein, we predicted the targets of carcinogenic mycotoxin-responsive miRNAs and analyzed their association with disease and functionality. miRNA target-derived prediction indicated potent associations of oncogenic mycotoxin exposure with metabolism- or hormone-related diseases, including sex hormone-linked cancers. Mechanistically, the signaling network evaluation suggested androgen receptor (AR)-linked signaling as a common pivotal cluster associated with metabolism- or hormone-related tumorigenesis in response to aflatoxin B1 and ochratoxin A co-exposure. Particularly, high levels of AR and AR-linked genes for the retinol and xenobiotic metabolic enzymes were positively associated with attenuated disease biomarkers and good prognosis in patients with liver or kidney cancers. Moreover, AR-linked signaling was protective against OTA-induced genetic insults in human hepatocytes whereas it was positively involved in AFB1-induced genotoxic actions. Collectively, miRNA target network-based predictions provide novel clinical insights into the progression or intervention against malignant adverse outcomes of human exposure to environmental oncogenic insults.

High-Throughput Determination of Major Mycotoxins with Human Health Concerns in Urine by LC-Q TOF MS and Its Application to an Exposure Study

Human biomonitoring constitutes a suitable tool to assess exposure to toxins overcoming the disadvantages of traditional methods. Urine constitutes an accessible biological matrix in biomonitoring studies. Mycotoxins are secondary metabolites produced naturally by filamentous fungi that produce a wide range of adverse health effects. Thus, the determination of urinary mycotoxin levels is a useful tool for assessing the individual exposure to these food contaminants. In this study, a suitable methodology has been developed to evaluate the presence of aflatoxin B2 (AFB2), aflatoxin (AFG2), ochratoxin A (OTA), ochratoxin B (OTB), zearalenone (ZEA), and α-zearalenol (α-ZOL) in urine samples as exposure biomarkers. For this purpose, different extraction procedures, namely, the Solid Phase Extraction (SPE); Dispersive Liquid–Liquid Microextraction (DLLME); and Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) methods were assessed, followed by Liquid Chromatography coupled to Quadrupole Time of Flight Mass Spectrometry with Electrospray Ionization (LC-ESI-QTOF-MS) determination. Then, the proposed methodology was applied to determine mycotoxin concentrations in 56 human urine samples from volunteers and to estimate the potential risk of exposure. The results obtained revealed that 55% of human urine samples analyzed resulted positive for at least one mycotoxin. Among all studied mycotoxins, only AFB2, AFG2, and OTB were detected with incidences of 32, 41, and 9%, respectively, and levels in the range from <LOQ to 69.42 µg/L. Risk assessment revealed a potential health risk, obtaining MoE values < 10,000. However, it should be highlighted that few samples were contaminated, and that more data about mycotoxin excretion rates and their BMDL10 values are needed for a more accurate risk assessment.

A novel chemical marker of tremorgenic mycotoxicosis detected by gas-chromatography/mass-spectrometry

Tremorgenic mycotoxicosis can arise from dietary exposure to secondary metabolite products of various fungal species, particularly those from the Penicillium genus. Although general toxin screens often rely on gas chromatography-mass spectrometry (GC/MS) and well-developed mass spectral library databases, two principal representative Penicillium mycotoxins, roquefortine and penitrem A, are unamenable to GC/MS owing to high molecular weights, low volatilities and/or high thermal instabilities. Reliance on GC/MS screens alone could therefore inadvertently result in failure to collect evidence of exposure to such tremorgenic mycotoxins. In this report we describe a newly discovered tremorgenic marker compound (TMC), the presence of which correlates highly with conclusive exposure to Penicillium toxins in explanation of clinical manifestations of tremorgenic mycotoxicosis. According to detailed mass spectral deconvolution, the compound is 210.0892 molecular weight, and amenable to GC/MS whether chemically underivatized or derivatized by methylation or trimethylsilylation. 1D and 2D NMR (nuclear magnetic resonance) studies on the isolated compound determined the TMC to be the Penicillium product terrestric acid, C11H14O4, which matches the molecular formula determined by high resolution mass spectrometry and thus provides an excellent target for assessment of mycotoxicosis by GC/MS.

Urinary Biomarkers of Mycotoxin Induced Nephrotoxicity-Current Status and Expected Future Trends

The intensifying world-wide spread of mycotoxigenic fungal species has increased the possibility of mycotoxin contamination in animal feed and the human food chain. Growing evidence shows the deleterious toxicological effects of mycotoxins from infants to adults, while large population-based screening programs are often missing to identify affected individuals. The kidney functions as the major excretory system, which makes it particularly vulnerable to nephrotoxic injury. However, few studies have attempted to screen for kidney injury biomarkers in large, mycotoxin-exposed populations. As a result, there is an urgent need to screen them with sensitive biomarkers for potential nephrotoxicity. Although a plethora of biomarkers have been tested to estimate the harmful effects of a wide spectrum of toxicants, β₂-microglobulin (β₂-MG) and N-acetyl-β-D-glucosaminidase (NAG) are currently the dominant biomarkers employed routinely in environmental toxicology research. Nevertheless, kidney injury molecule 1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) are also emerging as useful and informative markers to reveal mycotoxin induced nephrotoxicity. In this opinion article we consider the nephrotoxic effects of mycotoxins, the biomarkers available to detect and quantify the kidney injuries caused by them, and to recommend biomarkers to screen mycotoxin-exposed populations for renal damage.

Investigation of ochratoxin A biomarkers in biological materials obtained from patients suffering from renal cell carcinoma

Ochratoxin A (OTA) exposure can result in chronic renal diseases and cancer. The incidence of kidney, renal pelvis, and ureter malignant neoplasms in the Czech Republic is approximately 29.5 renal tumours per 100,000 inhabitants. The question arises whether mycotoxins are also involved in kidney disease and cancer. A sensitive validated analytical methodology, based on an immunoaffinity clean-up followed by HPLC with fluorescence detection, was developed to explore whether OTA accumulates in clear renal cell carcinoma-adenocarcinoma in Czech patients. Simultaneously, DNA-adducts and OTA metabolites were qualitatively analysed in tissues and urine. OTA was analysed in 33 kidney and tumour samples from 26 men and 7 women collected during nephrectomy from patients of the East Bohemian region from 2015 to 2017. OTA was found in 76% of the analysed samples. Its concentrations ranged from not detectable to 390 ng/kg with a median of 167 ng/kg in kidney samples and from not detectable to 430 ng/kg with a median of 122 ng/kg in tumour samples. Urinary OTA metabolites and DNA adducts were qualitatively analysed for the corresponding 20 patients. The presence of some OTA metabolites such as ochratoxin A hydroquinone and/or decarboxylated ochratoxin A hydroquinone correlate with the presence of OTA-DNA adducts.

Ochratoxins in Wines: A Review of Their Occurrence in the Last Decade, Toxicity, and Exposure Risk in Humans

Ochratoxins (OTs) are mycotoxins frequently found in wines, and their contamination can occur during any stage of the winemaking process. Ochratoxin A (OTA) has been the most widely reported and the only one whose concentrations are legislated in this beverage. However, ochratoxin B, ochratoxin A methyl ester, ochratoxin B methyl ester, ochratoxin A ethyl ester, ochratoxin B ethyl ester, ochratoxin α, ochratoxin β, OTα methyl ester, OTA ethyl amide, and OTA glucose ester have also been reported in wines. Thus, detecting only OTA would lead to the underestimation of ochratoxin levels, which is a risk to human health. Considering the threat represented by the presence of ochratoxins in wines and the long-term health problems that they can cause in wine drinkers, this paper aims to review reports of the last 10 years regarding the presence of different ochratoxins in wines and how the winemaking process influences the degree of contamination, mainly by OTA. Additionally, toxicity from human exposure due to the consumption of contaminated wines is addressed.

Citrinin Dietary Exposure Assessment Approach through Human Biomonitoring High-Resolution Mass Spectrometry-Based Data

Citrinin (CIT) is a scarcely studied mycotoxin within foodstuffs, so the biomonitoring of this toxin and its metabolite dihydrocitrinone (DH-CIT) in biological samples represents the main alternative to estimate the exposure. Hence, this study aimed to evaluate the presence of CIT and DH-CIT in 300 urine samples from Italian individuals in order to assess the exposure. Quantification was performed through an ultrahigh-performance liquid chromatography high-resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS)-based methodology. CIT was quantified in 47% of samples (n = 300) up to 4.0 ng/mg Crea (mean = 0.29 ng/mg Crea), whereas DH-CIT was quantified in 21% of samples up to 2.5 ng/mg Crea (mean = 0.39 ng/mg Crea). Considering different age groups, average exposure ranged from 8% to 40% of the provisional tolerable daily intake, whereas four individuals surpassed the limits suggested by the European Food Safety Authority. These results revealed non-negligible exposure levels to CIT, encouraging further investigation in foodstuffs monitoring studies.

Mycotoxins-Biomonitoring and Human Exposure

Mycotoxins are secondary metabolites produced by fungal species that commonly have a toxic effect on human and animal health. Different foodstuff can be contaminated and are considered the major source of human exposure to mycotoxins, but occupational and environmental exposure can also significantly contribute to this problem. This review aims to provide a short overview of the occurrence of toxigenic fungi and regulated mycotoxins in foods and workplaces, following the current literature and data presented in scientific papers. Biomonitoring of mycotoxins in plasma, serum, urine, and blood samples has become a common method for determining the exposure to different mycotoxins. Novel techniques are more and more precise and accurate and are aiming toward the simultaneous determination of multiple mycotoxins in one analysis. Application of liquid chromatography (LC) methodologies, coupled with tandem mass spectrometry (MS/MS) or high-resolution mass spectrometry (HRMS) has become a common and most reliable method for determining the exposure to mycotoxins. Numerous references confirm the importance of mycotoxin biomonitoring to assess the exposure for humans and animals. The objectives of this paper were to review the general approaches to biomonitoring of different mycotoxins and the occurrence of toxigenic fungi and their mycotoxins, using recent literature sources.

Presence of 19 Mycotoxins in Human Plasma in a Region of Northern Spain

This study was conducted to investigate human exposure to 19 compounds (mycotoxins and their metabolites) in plasma samples from healthy adults (n = 438, aged 19-68 years) from Navarra, a region of northern Spain. Samples were analyzed by LC-MS/MS, before and after enzymatic hydrolysis for the detection of possible glucuronides and/or sulfates (Phase II metabolites). The most prevalent mycotoxin was ochratoxin A (OTA), with an incidence of 97.3%. Positive samples were in the concentration range of 0.4 ng/mL to 45.7 ng/mL. After enzymatic treatment, OTA levels increased in a percentage of individuals, which may indicate the presence of OTA-conjugates. Regarding ochratoxin B, it has also been detected (10% of the samples), and its presence may be related to human metabolism of OTA. Sterigmatocystin was detected with a high incidence (85.8%), but only after enzymatic hydrolysis, supporting glucuronidation as a pathway of its metabolism in humans. None of the other studied mycotoxins (aflatoxins B1, B2, G1, G2 and M1; T-2 and HT-2 toxins; deoxynivalenol, deepoxy-deoxynivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol; zearalenone; nivalenol; fusarenon-X; neosolaniol; and diacetoxyscirpenol) were detected in any of the samples, neither before nor after enzymatic treatment. To the best of our knowledge, this is the first report carried out in Spain to determine the exposure of the population to mycotoxins and some of their metabolites using plasma, and the obtained results justify the need for human biomonitoring and metabolism studies on mycotoxins.

Mycotoxin exposure and human cancer risk: A systematic review of epidemiological studies

In recent years, there has been an increasing interest in investigating the carcinogenicity of mycotoxins in humans. This systematic review aims to provide an overview of data linking exposure to different mycotoxins with human cancer risk. Publications (2019 and earlier) of case-control or longitudinal cohort studies were identified in PubMed and EMBASE. These articles were then screened by independent reviewers and their quality was assessed according to the Newcastle-Ottawa scale. Animal, cross-sectional, and molecular studies satisfied criteria for exclusion. In total, 14 articles were included: 13 case-control studies and 1 longitudinal cohort study. Included articles focused on associations of mycotoxin exposure with primary liver, breast, and cervical cancer. Overall, a positive association between the consumption of aflatoxin-contaminated foods and primary liver cancer risk was verified. Two case-control studies in Africa investigated the relationship between zearalenone and its metabolites and breast cancer risk, though conflicting results were reported. Two case-control studies investigated the association between hepatocellular carcinoma and fumonisin B1 exposure, but no significant associations were observed. This systematic review incorporates several clear observations of dose-dependent associations between aflatoxins and liver cancer risk, in keeping with IARC Monograph conclusions. Only few human epidemiological studies investigated the associations between mycotoxin exposures and cancer risk. To close this gap, more in-depth research is needed to unravel evidence for other common mycotoxins, such as deoxynivalenol and ochratoxin A. The link between mycotoxin exposures and cancer risk has mainly been established in experimental studies, and needs to be confirmed in human epidemiological studies to support the evidence-based public health strategies.

Reviewing the Analytical Methodologies to Determine the Occurrence of Citrinin and its Major Metabolite, Dihydrocitrinone, in Human Biological Fluids

Until now, the available data regarding citrinin (CIT) levels in food and the consumption of contaminated foods are insufficient to allow a reliable estimate of intake. Therefore, biomonitoring configuring analysis of parent compound and/or metabolites in biological fluids, such as urine or blood, is being increasingly applied in the assessment of human exposure to CIT and its metabolite, dihydrocitrinone (DH-CIT). Most studies report urinary levels lower for the parent compound when compared with DH-CIT. A high variability either in the mean levels or in the inter-individual ratios of CIT/DH-CIT between the reported studies has been found. Levels of DH-CIT in urine were reported as being comprised between three to seventeen times higher than the parent mycotoxin. In order to comply with this objective, sensitive analytical methodologies for determining biomarkers of exposure are required. Recent development of powerful analytical techniques, namely liquid chromatography coupled to mass spectrometry (LC-MS/MS) and ultra-high-performance liquid chromatography (UHPLC-MS/MS) have facilitated biomonitoring studies, mainly in urine samples. In the present work, evidence on human exposure to CIT through its occurrence and its metabolite, in biological fluids, urine and blood/plasma, in different countries, is reviewed. The analytical methodologies usually employed to evaluate trace quantities of these two molecules, are also presented. In this sense, relevant data on sampling (size and pre-treatment), extraction, cleanup and detection and quantification techniques and respective chromatographic conditions, as well as the analytical performance, are evidenced.

Human Biomonitoring of Mycotoxins in Blood, Plasma and Serum in Recent Years: A Review

This manuscript reviews the state-of-the-art regarding human biological monitoring (HBM) of mycotoxins in plasma serum and blood samples. After a comprehensive and systematic literature review, with a focus on the last five years, several aspects were analyzed and summarized: a) the biomarkers analyzed and their encountered levels, b) the analytical methodologies developed and c) the relationship between biomarker levels and some illnesses. In the literature reviewed, aflatoxin B1-lysine (AFB1-lys) and ochratoxin A (OTA) in plasma and serum were the most widely studied mycotoxin biomarkers for HBM. Regarding analytical methodologies, a clear increase in the development of methods for the simultaneous determination of multiple mycotoxins has been observed. For this purpose, the use of liquid chromatography (LC) methodologies, especially when coupled with tandem mass spectrometry (MS/MS) or high resolution mass spectrometry (HRMS), has grown. A high percentage of the samples analyzed for OTA or aflatoxin B1 (mostly as AFB1-lys) in the reviewed papers were positive, demonstrating human exposure to mycotoxins. This review confirms the importance of mycotoxin human biomonitoring and highlights the important challenges that should be faced, such as the inclusion of other mycotoxins in HBM programs, the need to increase knowledge of mycotoxin metabolism and toxicokinetics, and the need for reference materials and new methodologies for treating samples. In addition, guidelines are required for analytical method validation, as well as equations to establish the relationship between human fluid levels and mycotoxin intake.

Citrinin biomarkers: a review of recent data and application to human exposure assessment

The mycotoxin citrinin (CIT) deserves attention due to its known toxic effects in mammalian species and a widespread occurrence in food commodities, often along with ochratoxin A, another nephrotoxic mycotoxin. Human exposure, a key element in assessing risks related to these food contaminants, depends upon mycotoxin levels in food and on food consumption. Yet, data available for CIT levels in food are insufficient for reliable intake estimates. Now biomonitoring, i.e., analysis of parent compound and/or metabolites in human specimen (blood, urine, breast milk), is increasingly used to investigate mycotoxin exposure. Biomonitoring requires sensitive methods for determining biomarkers of exposure, combined with kinetic data to conclude on the absorbed internal dose in an individual. Recent advances in LC-MS/MS-based analytical techniques have facilitated biomonitoring studies on the occurrence of CIT biomarkers in body fluids, mainly in urine samples. This review compiles evidence on human exposure to CIT in different countries, on CIT kinetics in humans, and on biomarker-based CIT intake estimates. Human CIT exposures are discussed in light of an intake value defined as 'level of no concern for nephrotoxicity' by the European Food Safety Agency, and some uncertainties in the toxicological data base. Further studies on CIT, including biomarker-based studies are warranted along with regular food surveys for this mycotoxin to protect consumers against undesirable health effects.