ZEN and the art of breast health maintenance

Endocrine Effect of Some Mycotoxins on Humans: A Clinical Review of the Ways to Mitigate the Action of Mycotoxins

Fungi such as Aspergillus spp. and Fusarium spp., which are commonly found in the environment, pose a serious global health problem. This study aims to present the results of epidemiological studies, including clinical cases, on the relationship between human exposure to some mycotoxins, especially zearalenone and aflatoxin, and the occurrence of reproductive disorders. In addition, examples of methods to reduce human exposure to mycotoxins are presented. In March 2023, various databases (PubMed, Google Scholar, EMBASE and Web of Science) were systematically searched using Google Chrome to identify studies evaluating the association between exposure to mycotoxins and the occurrence of complications related to impaired fertility or cancer incidence. The analysed data indicate that exposure to the evaluated mycotoxins is widespread and correlates strongly with precocious puberty, reduced fertility and increased cancer incidence in women and men worldwide. There is evidence to suggest that exposure to the Aspergillus mycotoxin aflatoxin (AF) during pregnancy can impair intrauterine foetal growth, promote neonatal jaundice and cause perinatal death and preterm birth. In contrast, exposure to the Fusarium mycotoxin zearalenone (ZEA) leads to precocious sexual development, infertility, the development of malformations and the development of breast cancer. Unfortunately, the development of methods (biological, chemical or physical) to completely eliminate exposure to mycotoxins has limited practical application. The threat to human health from mycotoxins is real and further research is needed to improve our knowledge and specific public health interventions.

Phytoestrogens and Health Effects

Phytoestrogens are literally estrogenic substances of plant origin. Although these substances are useful for plants in many aspects, their estrogenic properties are essentially relevant to their predators. As such, phytoestrogens can be considered to be substances potentially dedicated to plant-predator interaction. Therefore, it is not surprising to note that the word phytoestrogen comes from the early discovery of estrogenic effects in grazing animals and humans. Here, several compounds whose activities have been discovered at nutritional concentrations in animals and humans are examined. The substances analyzed belong to several chemical families, i.e., the flavanones, the coumestans, the resorcylic acid lactones, the isoflavones, and the enterolignans. Following their definition and the evocation of their role in plants, their metabolic transformations and bioavailabilities are discussed. A point is then made regarding their health effects, which can either be beneficial or adverse depending on the subject studied, the sex, the age, and the physiological status. Toxicological information is given based on official data. The effects are first presented in humans. Animal models are evoked when no data are available in humans. The effects are presented with a constant reference to doses and plausible exposure.

Elucidation of xenoestrogen metabolism by non-targeted, stable isotope-assisted mass spectrometry in breast cancer cells

Environmental exposure to xenoestrogens, i.e., chemicals that imitate the hormone 17β-estradiol, has the potential to influence hormone homeostasis and action. Detailed knowledge of xenobiotic biotransformation processes in cell models is key when transferring knowledge learned from in vitro models to in vivo relevance. This study elucidated the metabolism of two naturally-occurring phyto- and mycoestrogens; namely genistein and zearalenone, in an estrogen receptor positive breast cancer cell line (MCF-7) with the aid of stable isotope-assisted metabolomics and the bioinformatic tool MetExtract II. Metabolism was studied in a time course experiment after 2 h, 6 h and 24 h incubation. Twelve and six biotransformation products of zearalenone and genistein were detected, respectively, clearly demonstrating the abundant xenobiotic biotransformation capability of the cells. Zearalenone underwent extensive phase-I metabolism resulting in α-zearalenol (α-ZEL), a molecule known to possess a significantly higher estrogenicity, and several phase-II metabolites (sulfo- and glycoconjugates) of the native compound and the major phase I metabolite α-ZEL. Moreover, potential adducts of zearalenone with a vitamin and several hydroxylated metabolites were annotated. Genistein metabolism resulted in sulfation, combined sulfation and hydroxylation, acetylation, glucuronidation and unexpectedly adduct formation with pentose- and hexose sugars. Kinetics of metabolite formation and subsequent excretion into the extracellular medium revealed a time-dependent increase in most biotransformation products. The untargeted elucidation of biotransformation products formed during cell culture experiments enables an improved and more meaningful interpretation of toxicological assays and has the potential to identify unexpected or unknown metabolites.

Biosorptive detoxification of zearalenone biotoxin by surface-modified renewable biomass: process dynamics and application

BACKGROUND

Contamination of food, feed, beverages and even drinking water with biotoxins is a growing global concern because of their potential health risks. In this work, surface-modified sugar beet pulp waste was used for the biosorptive removal of zearalenone biotoxin from contaminated aquatic media.

RESULTS

Infrared, Boehm titration, BET (Brunauer-Emmett-Teller) surface area and point of zero charge analysis were employed for surface characterization. Kinetic and equilibrium studies showed that biotoxin biosorption was well predicted by the pseudo-second-order kinetic model and the Langmuir isotherm model. Zearalenone was removed from the solution over a wide pH range (3.0-8.0) and within a short time (15 min). Maximum uptake capacity of modified biomass was recorded as 23.30 ± 0.17 g kg^-1 . Highest removal yield in a dynamic flow mode (94.56 ± 0.13%) was achieved at 2 mL min^-1 flow rate using 30 mg biosorbent. Regeneration experiments revealed high reusability potential of suggested biosorbent. Moreover, its application potential was tested in spiked samples of malt, beer and canned corn liquid.

CONCLUSION

Detoxification potential of this renewable biomass was significantly enhanced after modification. Modified biomass could be used as an efficient and low-cost green-type material with good application potential for zearalenone detoxification. © 2018 Society of Chemical Industry.

Effects of Modified Palygorskite Supplementation on Egg Quality and Mineral Element Content, and Intestinal Integrity and Barrier Function of Laying Hens

This study was conducted to investigate effects of modified palygorskite (MPal) supplementation on the laying performance, egg quality and mineral element content, immunity, oxidative status, and intestinal integrity and barrier function of laying hens. A total of 360 52-week-old Hyline Brown hens were randomly assigned into four dietary treatments for a 7-week feeding trial. The birds were fed a basal diet supplemented with 0 (control group), 0.25, 0.5, and 1 g/kg MPal, respectively. The supplementation of MPal did not alter laying performance and egg quality among groups. Compared with the control group, MPal inclusion decreased lead (Pb) content in yolks at 49 days, and either 0.5- or 1-g/kg MPal supplementation decreased Pb accumulation in yolks at 25 days and manganese (Mn) accumulation in yolks at 25 and 49 days. The contents of jejunal secretory immunoglobulin A (SIgA), ileal SIgA, and immunoglobulin G were decreased by the dietary 0.5-g/kg MPal supplementation. The supplementation of MPal also decreased malondialdehyde content in jejunum and ileum, and decreased serum diamine oxidase activity of the laying hens at 25 and 49 days. The inclusion of 0.5 and 1 g/kg MPal enhanced villus height in jejunum and ileum, and also increased the ratio of villus height to crypt depth in ileum. In conclusion, MPal supplementation decreased Pb and Mn contents in yolks, and exhibited beneficial effects on the intestinal immunity, oxidative status, and intestinal integrity and barrier function of laying hens and its optimal dosage was 0.5 g/kg.

Transcriptome analysis to identify the Ras and Rap1 signal pathway genes involved in the response of TM3 Leydig cells exposed to zearalenone

The mechanism of action of zearalenone (ZEA) in inducing germ cell tumors is unclear, and little is known about the change in the transcriptome of germ cells after ZEA exposure. To explore the molecular basis of the ZEA oncogene, we examined the median lethal concentration (50 μmol/L) and pro-apoptotic effect of ZEA on TM3 Leydig cells by MTT and TUNEL assay. Subsequently, we investigated the genetic changes in the transcriptome of TM3 Leydig cells exposed to 50 μmol/L ZEA. The transcriptome sequencing results show that 772 genes are significantly down-regulated, while 204 genes are significantly up-regulated. Gene ontology (GO) enrichment analysis shows that ZEA has a major effect on the connective function, cell composition, cell cycle, and energy metabolism of the TM3 Leydig cells. Using the results of the GO and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses, we select the Ras and Rap1 signaling pathways that are closely related to the occurrence of cancer. The differentially expressed genes visualized in the KEGG pathway were selected for RT-qPCR differential gene expression validation. The results show that the gene expression results are consistent with the transcriptome sequencing results. This study thus provides a theoretical molecular basis for the mechanism of ZEA carcinogenesis.

Levels of zearalenone and its metabolites in sun-dried kapenta fish and water of Lake Kariba in Zambia - A preliminary study

Contamination of food with mycotoxins and the associated possibilities of human intoxication is a serious problem in Africa. One of the most widespread mycotoxins is zearalenone (ZEN), which usually occurs in food of vegetable origin. On the other hand, information about ZEN in products of animal origin in African countries is extremely scanty. During the present study, levels of ZEN and its analogs: α-zearalenol (α-ZEL) and β-zearalenol (β-ZEL) were measured by high performance liquid chromatography (HPLC) with fluorescence detection in sun-dried kapenta fish - traditional Zambian food, as well as in the water of Lake Kariba - the main source of kapenta fish in Zambia. This study revealed that levels of ZEN in sun-dried kapenta fish fluctuated from 27.2 μg·kg^-1 to 53.9 μg·kg^-1, whereas the contamination of water from Lake Kariba with ZEN is rather minimally similar to the content of ZEN analogs in both kapenta fish and water. The obtained results have shown that sun-dried kapenta fish of Lake Kariba contain ZEN and may contribute to the exposure of consumers to this substance.

Effects of different levels of modified palygorskite supplementation on the growth performance, immunity, oxidative status and intestinal integrity and barrier function of broilers

This experiment was designed to investigate effects of different levels of modified palygorskite (MPal) supplementation on growth performance, immunity, oxidative status and intestinal integrity and barrier function of broilers. A total of 320 1-day-old Arbor Acres broilers were randomly assigned into 5 dietary treatments and fed a basal diet supplemented with 0, 0.25, 0.5, 1 and 2 g/kg MPal, respectively, for a 42-day feeding trial. Treatments quadratically reduced feed/gain ratio (F:G) during 1-21 days and linearly decreased average daily feed intake and F:G during 22-42 days, and linearly and quadratically decreased average daily feed intake and F:G during overall period (p < 0.05, 0.50 g/kg treatment showed the lowest F:G). MPal supplementation increased the contents of 21-day jejunal secretory immunoglobulin A (SIgA) quadratically, and 21-day jejunal immunoglobulin G (IgG), immunoglobulin M (IgM) and 42-day jejunal total superoxide dismutase (T-SOD) activity linearly and quadratically (0.50 g/kg treatment showed the highest immunoglobulin concentration), whereas linearly reduced 21-day ileal SIgA level and 42-day jejunal malondialdehyde (MDA) accumulation and serum diamine oxidase activity, and quadratically decreased 21-day ileal MDA level (p < 0.05). The 42-day jejunal SIgA, IgG and IgM concentrations, and T-SOD activity in jejunum at 21 days and ileum at both 21 days and 42 days were quadratically increased with MPal administration (p < 0.05, 0.50 g/kg treatment showed the highest T-SOD activity). The mucin 2 mRNA abundances in 42-day jejunum and 21-day ileum were quadratically increased with MPal supplementation (p < 0.05). Treatments linearly increased 42-day ileal zonula occludens-1, claudin-3 and jejunal claudin-3 mRNA level, whereas linearly and quadratically increased ileal claudin-2 mRNA level (p < 0.05). In conclusion, MPal supplementation exhibited beneficial effects on growth performance, intestinal immunity, antioxidant capacity and intestinal integrity and barrier function of broiler with its optimum dosage being 0.5 g/kg.

Metabolomics Reveals that Dietary Xenoestrogens Alter Cellular Metabolism Induced by Palbociclib/Letrozole Combination Cancer Therapy

Recently, the palbociclib/letrozole combination therapy was granted accelerated US FDA approval for the treatment of estrogen receptor (ER)-positive breast cancer. Since the underlying metabolic effects of these drugs are yet unknown, we investigated their synergism at the metabolome level in MCF-7 cells. As xenoestrogens interact with the ER, we additionally aimed at deciphering the impact of the phytoestrogen genistein and the estrogenic mycotoxin zearalenone. A global metabolomics approach was applied to unravel metabolite and pathway modifications. The results clearly showed that the combined effects of palbociclib and letrozole on cellular metabolism were far more pronounced than that of each agent alone and potently influenced by xenoestrogens. This behavior was confirmed in proliferation experiments and functional assays. Specifically, amino acids and central carbon metabolites were attenuated, while higher abundances were observed for fatty acids and most nucleic acid-related metabolites. Interestingly, exposure to model xenoestrogens appeared to counteract these effects.

Toxicodynamics of Mycotoxins in the Framework of Food Risk Assessment-An In Silico Perspective

Mycotoxins severely threaten the health of humans and animals. For this reason, many countries have enforced regulations and recommendations to reduce the dietary exposure. However, even though regulatory actions must be based on solid scientific knowledge, many aspects of their toxicological activity are still poorly understood. In particular, deepening knowledge on the primal molecular events triggering the toxic stimulus may be relevant to better understand the mechanisms of action of mycotoxins. The present work presents the use of in silico approaches in studying the mycotoxins toxicodynamics, and discusses how they may contribute in widening the background of knowledge. A particular emphasis has been posed on the methods accounting the molecular initiating events of toxic action. In more details, the key concepts and challenges of mycotoxins toxicology have been introduced. Then, topical case studies have been presented and some possible practical implementations of studying mycotoxins toxicodynamics have been discussed.

Occupational exposures and mammographic density in Spanish women

OBJECTIVES

The association between occupational exposures and mammographic density (MD), a marker of breast cancer risk, has not been previously explored. Our objective was to investigate the influence of occupational exposure to chemical, physical and microbiological agents on MD in adult women.

METHODS

This is a population-based cross-sectional study based on 1476 female workers aged 45-65 years from seven Spanish breast cancer screening programmes. Occupational history was surveyed by trained staff. Exposure to occupational agents was assessed using the Spanish job-exposure matrix MatEmESp. Percentage of MD was measured by two radiologists using a semiautomatic computer tool. The association was estimated using mixed log-linear regression models adjusting for age, education, body mass index, menopausal status, parity, smoking, alcohol intake, type of mammography, family history of breast cancer and hormonal therapy use, and including screening centre and professional reader as random effects terms.

RESULTS

Although no association was found with most of the agents, women occupationally exposed to perchloroethylene (e^β=1.51; 95% CI 1.04 to 2.19), ionising radiation (e^β=1.23; 95% CI 0.99 to 1.52) and mould spores (e^β=1.44; 95% CI 1.01 to 2.04) tended to have higher MD. The percentage of density increased 12% for every 5 years exposure to perchloroethylene or mould spores, 11% for every 5 years exposure to aliphatic/alicyclic hydrocarbon solvents and 3% for each 5 years exposure to ionising radiation.

CONCLUSIONS

Exposure to perchloroethylene, ionising radiation, mould spores or aliphatic/alicyclic hydrocarbon solvents in occupational settings could be associated with higher MD. Further studies are needed to clarify the accuracy and the reasons for these findings.

Zearalenone as an endocrine disruptor in humans

Zearalenone (ZEA), a fungal mycotoxin, is present in a wide range of human foods. Many animal studies have found ZEA to possess a disruptive effect on the hormonal balance, mainly due to its similarity to naturally-occurring estrogens. With increasing consciousness of the adverse effects of endocrine disruptors on human health, it is becoming more important to monitor ZEA concentrations in food and identify its potential effects on human health. Based on a review of recent studies on animal models and molecular pathways in which ZEA is reported to have an influence on humans, we postulate that ZEA might act as an endocrine disruptor in humans in a similar way to animals. Moreover, its endocrine-disrupting effect might be also a causative factor in carcinogenesis. This review article summarizes the latest knowledge about the influence of ZEA on the human hormonal balance.

Assessing the hydrolytic fate of the masked mycotoxin zearalenone-14-glucoside - A warning light for the need to look at the "maskedome"

Masked mycotoxins are plant metabolites of mycotoxins that contaminate food and feed. They pose health concern as the shortage of toxicological data forces the lack of regulation worldwide. The present work investigated the toxicological relevance of the masked mycotoxin zearalenone-14-glucoside. In vitro, it shows a lower toxicity in respect to the parent compound. However, the major risks related to the consumption of masked mycotoxins depend on the possibility to undergo hydrolysis. Therefore, the hydrolysis and further transformation of zearalenone-14-glucoside in bovine blood and blood components (i.e. plasma, serum and serum albumin) were monitored using LC/MS-MS analysis to gain insights on the possible systemic fate. Hydrolysis was observed in all matrices, and both cell-dependent and -independent contributions were pointed out. Moreover, further metabolism was observed in the whole blood as zearalenol isomers were found. Serum albumin was identified among the active components, and the protein-ligand interaction was investigated via computational analysis. The blood has been pointed out as possible district of reversion and further activation of zearalenone-14-glucoside, and a similar fate cannot be excluded for other masked mycotoxins. Therefore, the systemic hydrolysis should be evaluated beside the absorption, bioavailability and bioaccessibility to deeply understand the toxicity of masked mycotoxins.

Cytotoxic effects of zearalenone and its metabolites and antioxidant cell defense in CHO-K1 cells

Zearalenone (ZEA) and its metabolites (α-zearalenol; α-ZOL, β-zearalenol; β-ZOL) are secondary metabolites of Fusarium fungi that produce cell injury. The present study explores mycotoxin-induced cell damage and cellular protection mechanisms in CHO-K1 cells. Cytotoxicity has been determined by reactive oxygen species (ROS) production and DNA damage. ROS production was determined using the fluorescein assay and DNA strand breakage by comet assay. Intracellular protection systems were glutathione (GSH), glutathione peroxidase (GPx), catalase (CAT) and superoxide dismutase (SOD). The results demonstrated that all mycotoxins increased the ROS levels up to 5.3-fold the control levels in CHO-K1 cells. Zearalenone metabolites, but not ZEA, increased DNA damage 43% (α-ZOL) and 28% (β-ZOL) compared to control cells. The GSH levels decreased from 18% to 36%. The GPx and SOD activities respectively increased from 26% to 62% and from 23% to 69% in CHO-K1 cells, whereas CAT activity decreased from 14% to 52%. In addition, intracellular ROS production was induced by ZEA and its metabolites. The endogenous antioxidant system components GSH, GPx and SOD were activated against ZEA and its metabolites. These antioxidant system components thus could contribute to decrease cell injury by ZEA and its metabolites.

Protective effect of Crocin against zearalenone-induced oxidative stress in liver and kidney of Balb/c mice

Zearalenone (ZEN) is a mycotoxin from Fusarium species commonly found in many food commodities and known to cause reproductive disorders. Several studies have shown that ZEN is hematotoxic and hepatotoxic and causes several alterations of immunological parameters. In the present study, we aimed to evaluate the protective effect of Crocin (CRO), a natural carotenoid, against ZEN-induced toxicity in both renal and hepatic tissues of Balb/c mice. We demonstrated that ZEN (40 mg/kg body weight (b.w.)) induced oxidative stress in both kidney and liver as monitored by measuring the malondialdehyde (MDA) level, the protein carbonyl generation, the catalase and superoxide dismutase activity, and the expression of the heat shock proteins (Hsp70). However, combined treatment of ZEN with different doses of CRO (50, 100, and 250 mg/kg b.w.) significantly reduced ZEN-induced alterations in all tested oxidative stress markers. It could be concluded that CRO was effective in the protection against ZEN-induced toxicity in the liver and kidney of Balb/c mice.

Estrogenic endocrine disruptors: Molecular mechanisms of action

A comprehensive summary of more than 450 estrogenic chemicals including estrogenic endocrine disruptors is provided here to understand the complex and profound impact of estrogen action. First, estrogenic chemicals are categorized by structure as well as their applications, usage and effects. Second, estrogenic signaling is examined by the molecular mechanism based on the receptors, signaling pathways, crosstalk/bypassing and autocrine/paracrine/homeostatic networks involved in the signaling. Third, evaluation of estrogen action is discussed by focusing on the technologies and protocols of the assays for assessing estrogenicity. Understanding the molecular mechanisms of estrogen action is important to assess the action of endocrine disruptors and will be used for risk management based on pathway-based toxicity testing.

The Influence of Low Doses of Zearalenone on Distribution of Selected Active Substances in Nerve Fibers Within the Circular Muscle Layer of Porcine Ileum

The aim of this study was to investigate, whether low doses (25 % of no observable adverse effect levels values) of zearalenone (ZEN) can affect the expression of active substances in nerve fibers in the muscular layer of porcine ileum. The study was performed on ten immature pigs divided into two groups: experimental group (n = 5), where zearalenone (10 μg/kg body weight) was given for 42 days, and control animals (n = 5), where placebo was administered. Fragments of ileum of all animals were processed for single-labelling immunofluorescence technique using the antibodies against vasoactive intestinal peptide, neuronal form of nitric oxide synthase, cocaine and amphetamine regulatory peptide, galanin, pituitary adenylate cyclase-activating peptide-27 and substance P. The number of nerve fibers immunoreactive to particular substances was evaluated by the counting of nerves per observation field (0.1 mm²). Low doses of zearalenone caused the clear changes in the expression of substances studied. The number of nerve fibers immunoreactive to the majority of substances increased in experimental animals. The exception was only galanin, the expression of which was less after administration of zearalenone. The obtained results for the first time show that even low doses of zearalenone can affect the nerve fibers in the digestive tract.

Effects of zearalenone on oxidative stress and inflammation in weanling piglets

Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin produced by the fungi of Fusarium genera. Piglets were fed for 18 days with a control or a ZEN (316 ppb) contaminated diet. At the end of the experiment tissue samples were taken for assessment of: lymphocyte proliferation, monocytes and granulocytes respiratory burst, inflammatory cytokine synthesis in blood and liver, expression of genes involved in oxidative stress or in inflammation, plasma biochemical parameters, total antioxidant status and nitric oxide synthesis. In blood, ZEN increases the respiratory burst of monocytes and the inflammatory cytokine (TNF alpha, IL-1 beta, IFN gamma) synthesis, while in liver, ZEN decreases the synthesis of all inflammatory cytokines investigated. In liver and spleen, different effect on the expression of genes involved in oxidative stress and inflammation was observed. While in liver, ZEN decrease the expression of cyclooxigenase gene, but increase the expression of glutathione peroxydase and catalase genes; in spleen, ZEN induces a decrease of the superoxide dismutase gene expression together with an increase of the cyclooxigenase. In conclusion, our results showed that liver, spleen and blood may also be target tissues in weanling piglets fed ZEN contaminated diet, with different effects on oxidative stress and inflammation.

Ca(2+)-dependent suicidal erythrocyte death following zearalenone exposure

Zearalenone, a cereal mycotoxin with mycoestrogen activity and effect on fertility, is known to trigger apoptosis of a variety of nucleated cell types including hematopoietic progenitor cells. In analogy to apoptosis of nucleated cells, eryptosis, the suicidal death of erythrocytes, leads to cell shrinkage and cell membrane scrambling with phosphatidylserine exposure at the erythrocyte surface. The most important stimulator of eryptosis is an increase in cytosolic Ca(2+) activity ([Ca(2+)]i). The present study explored whether zearalenone triggers eryptosis. Erythrocyte volume was estimated from forward scatter, phosphatidylserine exposure at the erythrocyte surface from annexin-V binding, hemolysis from hemoglobin release, and [Ca(2+)]i from Fluo3 fluorescence. A 48-h exposure to zearalenone (≥25 μM) was followed by a significant increase in [Ca(2+)]i and annexin-V binding, and a significant decrease in forward scatter. The effect on annexin-V binding was significantly blunted in the nominal absence of extracellular Ca(2+). Zearalenone stimulates the suicidal erythrocyte death, an effect at least partially due to stimulation of Ca(2+) entry.