Zinc inhibits the reproductive toxicity of Zearalenone in immortalized murine ovarian granular KK-1 cells

Toxicity, biodegradation, and nutritional intervention mechanism of zearalenone

Zearalenone (ZEA), a global mycotoxin commonly found in a variety of grain products and animal feed, causes damage to the gastrointestinal tract, immune organs, liver and reproductive system. Many treatments, including physical, chemical and biological methods, have been reported for the degradation of ZEA. Each degradation method has different degradation efficacies and distinct mechanisms. In this article, the global pollution status, hazard and toxicity of ZEA are summarized. We also review the biological detoxification methods and nutritional regulation strategies for alleviating the toxicity of ZEA. Moreover, we discuss the molecular detoxification mechanism of ZEA to help explore more efficient detoxification methods to better reduce the global pollution and hazard of ZEA.

MnO2 nanosheets-triggered oxVB1 fluorescence immunoassay for detection zearalenone

In this study, an alkaline phosphatase (ALP)-mediated fluorescence immunoassay for detecting zearalenone (ZEN) was established based on the oxVB₁ fluorescence signal modulated by MnO₂ nanosheets (MnO₂ NS). As the ALP-antibody content increased, more 2-phosphoascorbic acid (AAP) was hydrolyzed to ascorbic acid (AA) which destroyed the MnO₂ NS rapidly. In the lack of MnO₂ NS, VB₁ cannot be oxidized to oxVB₁ for emitting fluorescence. On the contrary, the fluorescence of oxVB₁ recovered slowly with the decrease of the ALP-antibody concentration. In the optimization condition, the detection limit of this method was 15.5 pg mL^-1. Moreover, the recovery of ZEN in real samples ranged from 94.24 % to 108.26 %, which indicated the remarkable accuracy and reliability of this approach. Meanwhile, the proposal of this fluorescence immunoassay provided a new possibility for detecting other targets by replacing antibodies and antigens.

Zearalenone disturbs the reproductive-immune axis in pigs: the role of gut microbial metabolites

BACKGROUND

Exposure to zearalenone (ZEN, a widespread Fusarium mycotoxin) causes reproductive toxicity and immunotoxicity in farm animals, and it then poses potential threats to human health through the food chain. A systematic understanding of underlying mechanisms on mycotoxin-induced toxicity is necessary for overcoming potential threats to farm animals and humans. The gastrointestinal tract is a first-line defense against harmful mycotoxins; however, it remains unknown whether mycotoxin (e.g., ZEN)-induced toxicity on the reproductive-immune axis is linked to altered gut microbial metabolites. In this study, using pigs (during the three phases) as an important large animal model, we investigated whether ZEN-induced toxicity on immune defense in the reproductive-immune axis was involved in altered gut microbial-derived metabolites. Moreover, we observed whether the regulation of gut microbial-derived metabolites through engineering ZEN-degrading enzymes counteracted ZEN-induced toxicity on the gut-reproductive-immune axis.

RESULTS

Here, we showed ZEN exposure impaired immune defense in the reproductive-immune axis of pigs during phase 1/2. This impairment was accompanied by altered gut microbial-derived metabolites [e.g., decreased butyrate production, and increased lipopolysaccharides (LPS) production]. Reduction of butyrate production impaired the intestinal barrier via a GPR109A-dependent manner, and together with increased LPS in plasma then aggravated the systemic inflammation, thus directly and/or indirectly disturbing immune defense in the reproductive-immune axis. To validate these findings, we further generated recombinant Bacillus subtilis 168-expressing ZEN-degrading enzyme ZLHY-6 (the Bs-Z6 strain) as a tool to test the feasibility of enzymatic removal of ZEN from mycotoxin-contaminated food. Notably, modified gut microbial metabolites (e.g., butyrate, LPS) through the recombinant Bs-Z6 strain counteracted ZEN-induced toxicity on the intestinal barrier, thus enhancing immune defense in the reproductive-immune axis of pigs during phase-3. Also, butyrate supplementation restored ZEN-induced abnormalities in the porcine small intestinal epithelial cell.

CONCLUSIONS

Altogether, these results highlight the role of gut microbial-derived metabolites in ZEN-induced toxicity on the gut-reproductive-immune axis. Importantly, targeting these gut microbial-derived metabolites opens a new window for novel preventative strategies or therapeutic interventions for mycotoxicosis associated to ZEN.

Proteomic analysis of zearalenone toxicity on mouse thymic epithelial cells

Zearalenone (ZEA) is one of the most major food contaminants in cereal crops worldwide, risking health of both livestock and humans. This study aimed to assess the cytotoxicity and the underlying mechanism of ZEA on thymic epithelial cells. By using proteomics analysis, we identified 596 differentially expressed proteins in MTEC1 cells upon zearalenone exposure, of which 245 were upregulated and 351 were downregulated. Gene ontology (GO) analysis suggested that differentially expressed proteins were participated in protein synthesis, oxidative phosphorylation, and ATP binding. KEGG pathway enrichment analysis showed that differentially expressed proteins were mainly related to mitochndrial metabolism, such as citrate cycle (TCA cycle) and oxidative phosphorylation. We demonstrated that ZEA treatment was able to increase the intracellular reactive oxygen species (ROS) level, to decrease ΔΨm, ATP level, and the copy number of mtDNA, leading to necrotic cell death. Moreover, we showed that ZEA treatment inhibited cell proliferation and induced G2/M phase arrest by downregulation of proliferation-associated proteins ERK, p-ERK, CDK1, and p-CHK1. Taken together, we found that the toxicity of ZEA on thymic epithelial cells is mainly caused by the inhibition of mitochondrial dysfunction and cell proliferation. Our study might open new avenues for treatment strategies.

Scutellarin protects mouse ovarian granulosa cells from injury induced by the toxin zearalenone

Zearalenone (ZEA), present in animal grain feed is produced by Fusarium fungi and this toxin targets ovarian granulosa cells (GCs) to cause reproductive disorders in female animals. Current research on drugs that can rescue ZEA-induced ovarian GC damage is limited. The purpose of this study was to explore the effect of scutellarin (Scu) on ZEA-induced apoptosis of mouse ovarian GCs and its mechanism. In one set of experiments, the primary cultured mouse ovarian GCs were co-treated with ZEA and Scu for 24 h. The results showed that Scu significantly alleviated ZEA-induced cell damage, restored cell cycle arrest, and inhibited apoptosis by reducing the ratio of cleaved-caspase-3, cleaved-PARP, and Bax/Bcl-2. In another set of experiments, six-week-old mice were intragastrically administered with 40 mg kg-1 ZEA for 2 h, followed by 100 mg kg-1 Scu for 3 days. It was observed that Scu inhibited ZEA-induced apoptosis and positive signal expression of cleaved-caspase-3 in the ovarian granulosa layer, with the involvement of the mitochondrial apoptotic pathway. These data provide strong evidence that Scu can be further developed as a potential new therapeutic drug for preventing or treating reproductive toxicity caused by the exposure of animals to ZEA found in the grains of animal feeds.

Impact of Fusarium-Derived Mycoestrogens on Female Reproduction: A Systematic Review

Contamination of the world’s food supply and animal feed with mycotoxins is a growing concern as global temperatures rise and promote the growth of fungus. Zearalenone (ZEN), an estrogenic mycotoxin produced by Fusarium fungi, is a common contaminant of cereal grains and has also been detected at lower levels in meat, milk, and spices. ZEN’s synthetic derivative, zeranol, is used as a growth promoter in United States (US) and Canadian beef production. Experimental research suggests that ZEN and zeranol disrupt the endocrine and reproductive systems, leading to infertility, polycystic ovarian syndrome-like phenotypes, pregnancy loss, and low birth weight. With widespread human dietary exposure and growing experimental evidence of endocrine-disrupting properties, a comprehensive review of the impact of ZEN, zeranol, and their metabolites on the female reproductive system is warranted. The objective of this systematic review was to summarize the in vitro, in vivo, and epidemiological literature and evaluate the potential impact of ZEN, zeranol, and their metabolites (commonly referred to as mycoestrogens) on female reproductive outcomes. We conducted a systematic review (PROSPERO registration CRD42020166469) of the literature (2000–2020) following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The data sources were primary literature published in English obtained from searching PubMed, Web of Science, and Scopus. The ToxR tool was applied to assess risk of bias. In vitro and in vivo studies (n = 104) were identified and, overall, evidence consistently supported adverse effects of mycoestrogens on physiological processes, organs, and tissues associated with female reproduction. In non-pregnant animals, mycoestrogens alter follicular profiles in the ovary, disrupt estrus cycling, and increase myometrium thickness. Furthermore, during pregnancy, mycoestrogen exposure contributes to placental hemorrhage, stillbirth, and impaired fetal growth. No epidemiological studies fitting the inclusion criteria were identified.

Multidimensional analysis of the epigenetic alterations in toxicities induced by mycotoxins

Mycotoxins contaminate all types of food and feed, threatening human and animal health through food chain accumulation, producing various toxic effects. Increasing attention is being focused on the molecular mechanism of mycotoxin-induced toxicity in all kinds of in vivo and in vitro models. Epigenetic alterations, including DNA methylation, non-coding RNAs (ncRNAs), and protein post-translational modifications (PTMs), were identified as being involved in various types of mycotoxin-induced toxicity. In this review, the emphasis was on summarizing the epigenetic alterations induced by mycotoxin, including aflatoxin B1 (AFB1), ochratoxin A (OTA), zearalenone (ZEA), fumonisin B1 (FB1), and deoxynivalenol (DON). This review summarized and analyzed the roles of DNA methylation, ncRNAs, and protein PTMs after mycotoxin exposure based on recently published papers. Moreover, the main research methods and their deficiencies were determined, while some remedial suggestions are proposed. In summary, this review helps to understand better the epigenetic alterations induced by the non-genotoxic effects of mycotoxin.

IRE1 and CaMKKβ pathways to reveal the mechanism involved in microcystin-LR-induced autophagy in mouse ovarian cells

Microcystin-LR (MC-LR) is an emerging water pollutant produced by blooming cyanobacteria. It could be absorbed into human body via contaminated food and drinking water causing severe reproductive toxicity. Previous studies showed that MC-LR could regulate autophagy by inducing endoplasmic reticulum (ER) stress thereby causing female reproductive toxicity. However, the molecular mechanisms of MC-LR-induced autophagy remain to be elucidated. It is known that IRE1 and CaMKKβ pathways are two important pathways involved in autophagy induced by ER stress. Hence, this study investigated the roles of both pathways in MC-LR-induced autophagy in mouse ovarian cells. The results showed that MC-LR significantly up-regulated the expression of autophagy marker proteins LC3Ⅱ and BECLIN1 and down-regulated the expression of P62 in vivo and in vitro. MC-LR-caused increase of autophagosomes could be observed in KK-1 cells by MDC staining. MC-LR induced the formation of autolysosomes as indicated by the overlap of LAMP1 and LC3. Meanwhile, MC-LR significantly activated the proteins in IRE1 pathway (IRE1, XBP1 and JNK) and in CaMKKβ pathway (CaMKKβ, AMPK, mTOR). Furthermore, MC-LR caused weight loss and ovarian histopathological damage in mice. In contrast, after the expression and function of IRE1 and CaMKKβ were inhibited with siRNA in vitro and by inhibitors (4μ8C and STO-609, respectively) in vivo, the up-regulation of LC3Ⅱ and BECLIN1 and the degradation of P62 induced by MC-LR were significantly suppressed. MC-LR-induced autophagosomes in KK-1 cells and autolysosomes in mouse ovarian cells were also decreased. Moreover, the knockdown of IRE1 and CaMKKβ relieved MC-LR-induced histopathological injury to mouse ovaries. These results indicated that MC-LR induced ovarian cell autophagy and ovarian injury via IRE1 and CaMKKβ pathways. This study is the first study revealing the molecular mechanisms of MC-LR-induced autophagy of ovarian cells and providing new insights into the female reproductive toxicity of MC-LR.

Chlorogenic acid rescues zearalenone induced injury to mouse ovarian granulosa cells

Zearalenone (ZEA), a toxic substance produced by Fusarium fungi, accumulated in cereals grain and animal feed, causes injury to humans and animals. ZEA can induce obvious reproductive toxicity with the ovarian granulosa cells (GCs) as the main target. However, the study on exploring the protective compounds against ZEA-induced mouse primary ovarian GCs damage remains less. In the current study, the protective effect of 20 compounds derived from traditional Chinese medicines (TCMs) on the injury of mouse GCs caused by ZEA were evaluated using MTT assay and the cell morphology. Our results showed that chlorogenic acid (250, 500, and 1000 μg/mL) significantly suppress ZEA-induced GCs death. Western blot analysis suggested chlorogenic acid could rescue the up-regulated apoptosis of GCs induced by ZEA via attenuating the protein expression of cleaved caspase-3, the ratio of Bax/Bcl-2 and cleaved-PARP. Our results provide strong evidence that chlorogenic acid warrants further optimization for more potent and safer compounds for against the ZEA lead toxicity to humans and animals.

Mitigative effects of zinc on cadmium-induced reproductive toxicity in the male freshwater crab Sinopotamon henanense

Cadmium (Cd) is a highly harmful environmental contaminant, which can cause reproductive toxicity. Zinc (Zn) is an essential trance element that may protect the organism from the harmful effects of Cd. However, the mechanism of Zn against Cd-induced reproductive toxicity remained to be elucidated. The aim of this study was to assess the effects of subchronic exposure to Cd on the relative testis weight (RTW), the histopathology, the activity of stress marker antioxidant enzymes, the level of lipid peroxidation of testis, as well as the mitigative effects of Zn on Cd-induced reproductive toxicity in male freshwater crab Sinopotamon henanense. For this purpose, male crabs were divided into 10 groups including a control group (without metals) and metal exposure groups with Cd alone in three concentrations and Cd combined with Zn in six concentrations for 14 days. The results showed that Cd evoked concentration-dependent reproductive toxicity of male Sinopotamon henanense as showed by decreased RTW, appearance of morphological lesions, increased SOD, CAT, GPx activity, and MDA levels. Nevertheless, Zn combined with Cd exposure significantly alleviated Cd-induced reproductive toxicity as proved by increased RTW, reappearance of normal histological morphology, increased SOD activity, recovered CAT and GPx activity, and decreased MDA levels in testis. Our study demonstrated that the application of Zn can mitigate Cd-induced reproductive toxicity by ameliorating the testicular oxidative stress and improving the antioxidant status.

Urinary mycoestrogens and age and height at menarche in New Jersey girls

BACKGROUND

Despite evidence of the endocrine disrupting properties of zearalenone (ZEN) and alpha-zearalanol (zeranol, α-ZAL), they have been minimally studied in human populations. In previous cross-sectional analyses, we demonstrated that 9-10 years old girls with detectable urinary ZEN were of shorter stature and less likely to have reached the onset of breast development than girls with undetectable urinary ZEN. The aim of this study was to examine baseline concentrations of ZEN, (α-ZAL), and their phase-1 metabolites in relation to subsequent growth and timing of menarche using 10 years of longitudinal data.

METHODS

Urine samples were collected from participants in the Jersey Girl Study at age 9-10 (n = 163). Unconjugated ZEN, (α-ZAL), and their metabolites were analyzed using high performance liquid chromatography and tandem mass spectrometry. Information on height, weight, and pubertal development was collected at a baseline visit with annual follow-up by mail thereafter. Cox regression was used to evaluate time to menarche in relation to baseline ZEN, (α-ZAL), and total mycoestrogen exposure. Z-scores for height and weight were used in mixed models to assess growth.

RESULTS

Mycoestrogens were detectable in urine in 78.5% of the girls (median ZEN: 1.02 ng/ml, range 0-22.3). Girls with detectable urinary concentrations of (α-ZAL) and total mycoestrogens (sum of ZEN, (α-ZAL) and their metabolites) at baseline were significantly shorter at menarche than girls with levels below detection (p = 0.04). ZEN and total mycoestrogen concentrations were inversely associated with height- and weight-z-scores at menarche (adjusted β = - 0.18, 95% CI: -0.29, - 0.08, and adjusted β = - 0.10, 95% CI: -0.21, 0.01, respectively).

CONCLUSION

This study supports and extends our previous results suggesting that exposure to ZEN, (α-ZAL), and their metabolites is associated with slower growth and pubertal development in adolescent girls.

Oxidative Stress Mediates Microcystin-LR-Induced Endoplasmic Reticulum Stress and Autophagy in KK-1 Cells and C57BL/6 Mice Ovaries

Microcystin-leucine arginine (MC-LR) is a cyclic heptapeptide intracellular toxin released by cyanobacteria that exhibits strong reproductive toxicity. However, little is known about its biotoxicity to the female reproductive system. The present study investigates unexplored molecular pathways by which oxidative stress acts on MC-LR-induced endoplasmic reticulum stress (ERs) and autophagy. In the present study, immortalized murine ovarian granular cells (KK-1 cells) were exposed to 8.5, 17, and 34 μg/mL (IC₅₀) of MC-LR with or without N-acetyl-l-cysteine (NAC, 10 mM) for 24 h, and C57BL/6 mice were treated with 12.5, 25.0, and 40.0 μg/kg⋅bw of MC-LR with or without NAC (200 mg/kg⋅bw) for 14 days. The results revealed that MC-LR could induce cells apoptosis and morphologic changes in ovarian tissues, induce oxidative stress by stimulating the generation of reactive oxygen species (ROS), destroying antioxidant capacity, and subsequently trigger ERs and autophagy by inducing the hyper-expression of ATG12, ATG5, ATG16, EIF2α (phosphorylated at S51), CHOP, XBP1, GRP78, Beclin1, and PERK (Thr980). Furthermore, NAC pretreatment partly inhibited MC-LR-induced ERs and autophagy via the PERK/ATG12 and XBP1/Beclin1 pathways. These results suggest that oxidative stress mediated MC-LR-induced ERs and autophagy in KK-1 cells and C57BL/6 mice ovaries. Therefore, oxidative stress plays an important role in female toxicity induced by MC-LR.

Protective effects of compound ammonium glycyrrhizin, L‑arginine, silymarin and glucurolactone against liver damage induced by ochratoxin A in primary chicken hepatocytes

Ochratoxin A (OTA) is a mycotoxin that is produced by fungi in improperly stored food and animal feed. It exhibits nephrotoxic, hepatotoxic, embryotoxic, teratogenic, neurotoxic, immunotoxic and carcinogenic effects in laboratory and farm animals. In the present study, the hepatotoxicity of OPA was investigated in chicken primary hepatocytes. On this basis, the cytoprotective effects of compound ammonium glycyrrhizin (CAG), L‑arginine (L‑Arg), silymarin (Sil) and glucurolactone (GA) were investigated in vitro. Hepatocytes were treated with OTA, which resulted in a significant decrease in cell viability and increases in serum aspartate transaminase and alanine transaminase activities, as determined by an MTT assay and commercial kits, respectively. Furthermore, following OTA treatment, the levels of hepatic antioxidants, such as superoxide dismutase and glutathione, were decreased, and the lipid peroxidation product malondialdehyde was increased, compared with the control group. However, pretreatment with CAG, L‑Arg, Sil and GA significantly ameliorated these alterations and Sil exerted the optimum hepatoprotective effect. The apoptotic rates were measured by flow cytometry and the results revealed that OTA increased cell apoptosis. The four types of hepatoprotective compounds employed in the present study decreased the apoptosis rate and significantly reversed OTA‑induced increases in the mRNA expression levels of caspase‑3, which was determined by reverse transcription‑quantitative polymerase chain reaction. Furthermore, B‑cell lymphoma‑2 (Bcl‑2) mRNA expression was increased in OTA‑treated cells when pretreated with CAG, L‑Arg, Sil and GA. However, no alterations in the mRNA expression of Bcl‑2‑associated X were observed in the L‑Arg and GA groups, compared with the OTA‑only group. These results indicate that OTA may exhibit hepatotoxicity in chickens and that CAG, L‑Arg, Sil and GA may protect the liver against this via anti‑oxidative and antiapoptosis mechanisms. In addition, CAG and GA are likely to mediate their effects through the mitochondrion‑dependent apoptosis pathway; however, the exact hepatoprotective mechanism of L‑Arg and GA require further investigation. Therefore, CAG, L‑Arg, Sil and GA are potential candidates for the prevention and treatment of chicken liver injury.

Mycotoxin zearalenone induced gonadal impairment and altered gene expression in the hypothalamic-pituitary-gonadal axis of adult female zebrafish (Danio rerio)

In the present study, we aimed to assess the adverse effects of zearalenone (ZEA) at environmentally relevant concentrations (0.5, 1, 5 and 10 μg l^-1 ) on hypothalamic-pituitary-gonadal axis associated reproductive function using zebrafish model. ZEA was exposed to female zebrafish for 21 days to assess growth indices such as condition factor, hepatosomatic index, gonadosomatic index and caspase 3 activity. Further, expression of estrogen receptor (ER) α and CYP19a1b genes in the brain, ERα and vitellogenin (Vtg) genes in the liver and follicle-stimulating hormone receptor, luteinizing hormone receptor, ERα, steroidogenic acute regulatory protein, 3β-hydroxysteroid dehydrogenase (HSD), 17-βHSD and CYP19a1 genes in the ovary were also investigated. Our results showed that there were no significant changes in the condition factor and hepatosomatic index, whereas a significant (P < .05) reduction in the gonadosomatic index, increase in caspase 3 activities and Vtg expression was observed at higher concentration. However, no significant changes were observed at lower treatment levels. Further, we also observed significant (P < .05) upregulation in ERα, Vtg, luteinizing hormone receptor, steroidogenic acute regulatory protein, 3β-HSD, 17β-HSD, CYP19a1 and CYP19a1b genes in treatment groups with higher levels of ZEA. Moreover, in histopathological examination, we observed oocyte atresia and oocyte membrane detachment in ovaries at the highest concentration. In conclusion, the present study revealed the negative impact of ZEA on zebrafish reproductive system by involvement of the hypothalamic-pituitary-gonadal axis-associated reproductive function.

Zearalenone altered the cytoskeletal structure via ER stress- autophagy- oxidative stress pathway in mouse TM4 Sertoli cells

The aim of this study was to investigate the molecular mechanisms of the destruction of cytoskeletal structure by Zearalenone (ZEA) in mouse-derived TM4 cells. In order to investigate the role of autophagy, oxidative stress and endoplasmic reticulum(ER) stress in the process of destruction of cytoskeletal structure, the effects of ZEA on the cell viability, cytoskeletal structure, autophagy, oxidative stress, ER stress, MAPK and PI3K- AKT- mTOR signaling pathways were studied. The data demonstrated that ZEA damaged the cytoskeletal structure through the induction of autophagy that leads to the alteration of cytoskeletal structure via elevated oxidative stress. Our results further showed that the autophagy was stimulated by ZEA through PI3K-AKT-mTOR and MAPK signaling pathways in TM4 cells. In addition, ZEA also induced the ER stress which was involved in the induction of the autophagy through inhibiting the ERK signal pathway to suppress the phosphorylation of mTOR. ER stress was involved in the damage of cytoskeletal structure through induction of autophagy by producing ROS. Taken together, this study revealed that ZEA altered the cytoskeletal structure via oxidative stress - autophagy- ER stress pathway in mouse TM4 Sertoli cells.

Zinc enhances the cellular energy supply to improve cell motility and restore impaired energetic metabolism in a toxic environment induced by OTA

Exogenous nutrient elements modulate the energetic metabolism responses that are prerequisites for cellular homeostasis and metabolic physiology. Although zinc is important in oxidative stress and cytoprotection processes, its role in the regulation of energetic metabolism remains largely unknown. In this study, we found that zinc stimulated aspect in cell motility and was essential in restoring the Ochratoxin A (OTA)-induced energetic metabolism damage in HEK293 cells. Moreover, using zinc supplementation and zinc deficiency models, we observed that zinc is conducive to mitochondrial pyruvate transport, oxidative phosphorylation, carbohydrate metabolism, lipid metabolism and ultimate energy metabolism in both normal and toxic-induced oxidative stress conditions in vitro, and it plays an important role in restoring impaired energetic metabolism. This zinc-mediated energetic metabolism regulation could also be helpful for DNA maintenance, cytoprotection and hereditary cancer traceability. Therefore, zinc can widely adjust energetic metabolism and is essential in restoring the impaired energetic metabolism of cellular physiology.

Bentonite modified with zinc enhances aflatoxin B1 adsorption and increase survival of fibroblasts (3T3) and epithelial colorectal adenocarcinoma cells (Caco-2)

Bentonites are commonly used as feed additives to reduce the bioavailability and thus the toxicity of aflatoxins by adsorbing the toxins in the gastrointestinal tract. Aflatoxins are particular harmful mycotoxins mainly found in areas with hot and humid climates. They occur in food and feedstuff as a result of fungal contamination before and after harvest. The aim of this study was to modify Brazilian bentonite clay by incorporation of zinc (Zn) ions in order to increase the adsorption capacity and consequently reduce the toxicity of aflatoxins. The significance of Zn intercalating conditions such as concentration, temperature and reaction time were investigated. Our results showed that the Zn treatment of the bentonite increased the aflatoxin B₁ (AFB₁) adsorption and that Zn concentration had a negative effect. Indeed, temperature and time had no significant effect in the binding capacity. The modified bentonite (Zn-Bent1) was not cytotoxic to either fibroblasts (3T3) nor epithelial colorectal adenocarcinoma cells (Caco-2) cell lines. Interestingly, Zn-Bent1 has higher protective effect against AFB₁ induced cytotoxicity than the unmodified bentonite. In conclusion, the Zn modified bentonite, Zn-Bent1, represent an improved tool to prevent aflatoxicosis in animals fed on AFB₁ contaminated feed.

Effects of Electron Beam Irradiation on Zearalenone and Ochratoxin A in Naturally Contaminated Corn and Corn Quality Parameters

Zearalenone (ZEN) and ochratoxin A (OTA) are secondary toxic metabolites widely present in grains and grain products. In this study, the effects of electron beam irradiation (EBI) on ZEN and OTA in corn and the quality of irradiated corn were investigated. Results indicated that EBI significantly affected ZEN and OTA. The degradation rates of ZEN and OTA at 10 kGy in solution were 65.6% and 75.2%, respectively. The initial amounts significantly affected the degradation rate. ZEN and OTA in corn were decreased by the irradiation dose, and their degradation rates at 50 kGy were 71.1% and 67.9%, respectively. ZEN and OTA were more easily degraded in corn kernel than in corn flour. Moisture content (MC) played a vital role in ZEN and OTA degradation. High MC was attributed to high ZEN and OTA degradation. The quality of irradiated corn was evaluated on the basis of irradiation dose. L* value changed, but this change was not significant (p > 0.05). By contrast, a* and b* decreased significantly (p < 0.05) with irradiation dose. The fatty acid value increased significantly. The pasting properties, including peak, trough, breakdown, and final and setback viscosities, were also reduced significantly (p < 0.05) by irradiation. Our study verified that EBI could effectively degrade ZEN and OTA in corn. Irradiation could also affect corn quality.

Proanthocyanidin protects against acute zearalenone-induced testicular oxidative damage in male mice

Zearalenone (ZEN) exerts a major effect on human and animal health and has led to serious worldwide economic problems. In this study, we investigated whether proanthocyanidin (PC) can prevent ZEN-induced testicular oxidative damage in male mice and explored the underlying mechanism. Kunming mice were injected with ZEN (40 mg kg^-1) on the 11th day after intragastric administration of PC (75 or 150 mg/kg) for 10 days; the sperm quality of mice was then analysed statistically. Additionally, testicular morphology parameters related to oxidative damage, apoptosis and the expression of endoplasmic reticulum (ER) stress-related genes (GRP78, CHOP and XBP-1) were all measured. Results showed that ZEN exposure significantly reduced the sperm density, improved the sperm aberration rate, increased the MDA level and reduced SOD and GSH-Px activities. Meanwhile, ZEN was attributed to the downregulation of the expressions of the gene and protein of Bcl-2 and upregulation of the expressions of the gene and protein of Bax and caspase-3. ZEN exposure also upregulated the mRNA expression of GRP78, CHOP and XBP-1; however, PC pre-treatment reduced ZEN-induced oxidative damage and tended to maintain normal testicular morphology. Furthermore, PC pre-treatment substantially downregulated the expressions of the GRP78, CHOP and XBP-1 and upregulated the expression of the Bcl-2 gene. In conclusion, PC, due to its anti-oxidative ability, could ameliorate ZEN-induced testicular reproductive toxicity in male mice by decreasing ER stress and testicular cell apoptosis.

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.

The Influence of Selenium Yeast on Hematological, Biochemical and Reproductive Hormone Level Changes in Kunming Mice Following Acute Exposure to Zearalenone

Healthy male Kunming mice received selenium yeast for 14 days prior to a single oral administration of zearalenone (ZEN). After 48 h, blood samples were collected for analysis and showed that mice in the ZEN-treated group has significantly decreased lymphocytes (P < 0.05) and platelets (P < 0.05) along with an increased white blood cell (WBC) count and other constituents (P < 0.05). The serum biochemistry analysis of the ZEN group indicated that glutamic pyruvic transaminase (ALT), glutamic oxaloacetic transaminase (AST), urea, and uric acid were significantly increased (P < 0.05), whilst total bilirubin (TB) and albumin (ALB) were decreased along with serum testosterone and estrogen (P < 0. 05). The level of malondialdehyde (MDA) in the serum of the ZEN group was significantly increased whilst glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) had significantly decreased (P < 0.05). Treatment with selenium yeast had a significant effect on response with most of the experimental parameters returning to levels similar to those observed in the untreated control mice. From these data, it can be concluded that ZEN is highly poisonous in Kunming mice with high levels of toxicity on the blood, liver, and kidneys. High levels of oxidative stress were observed in mice and pre-treatment with selenium yeast by oral gavage is effective in the ameliorated effects of ZEN-induced damage.

Zinc inhibits aflatoxin B1-induced cytotoxicity and genotoxicity in human hepatocytes (HepG2 cells)

Aflatoxin B1 (AFB1) has strong carcinogenicity. Consumption of AFB1-contaminated agricultural products and the occurrence of hepatocellular carcinoma have received widespread attention. The aim of this paper was to investigate whether zinc supplementation could inhibit AFB1-induced cytotoxicity and genotoxicity in HepG2 cells and the mechanism of this inhibition. Our data suggest that zinc sources can relieve a certain degree of AFB1-induced cytotoxicity and genotoxicity by protecting against apoptotic body formation and DNA strand breaks, affecting S phase cell cycle arrest, reducing 8-OHdG formation, inhibiting global DNA hypomethylation and regulating gene expression in antioxidation, zinc-association and apoptosis processes. Consequently, zinc stabilizes the integrity of DNA and improves cell survival. These data provides new insights into the protective role of zinc in alleviating AFB1-induced cytotoxicity and mediating epigenetic changes in hepatocytes, demonstrating that zinc sources have detoxification properties in mycotoxin-induced toxicity.