Ochratoxin A: developmental and reproductive toxicity-an overview

Gut microbiota modulation by L-Fucose as a strategy to alleviate Ochratoxin A toxicity on primordial follicle formation

In this study, we investigated the potential benefits of L-Fucose administration to pregnant mice exposed to Ochratoxin A (OTA), a widespread mycotoxin, producing ovarian damage in offspring. The results showed that administration of 3.5 μg/d OTA induced alterations in intestinal tissues and gut microbiota of pregnant mice, leading to heightened local and systemic inflammation. This inflammatory affected the ovaries of their 3 dpp offspring, in which elevated levels of LPS and ROS were found associated to significant decreased oocyte count and impaired primordial follicle assembly. Moreover, mRNA-Seq analysis showed significant changes in ovarian transcriptomes linked to various GO terms and KEGG pathways, notably ferroptosis, a recognized form of cell death observed. Interestingly, administration of 0.3 g/kg b. w. L-Fucose following OTA exposure mitigated these effects on intestinal tissues and gut microbiota in mothers and on the offspring's ovaries. Similar benefits were obtained by gut microbiota transplantation from L-Fucose-treated pregnant females into OTA-exposed mothers. These findings suggest that inflammatory impact of OTA on maternal intestine/gut can pass to the fetus causing offspring ovary defects and support the use of L-Fucose as adjuvant to counteract the adverse effects of mycotoxins on the gut microbiota, particularly reference to those affecting reproductive organs.

The Influence of Environmental Exposure to Xenoestrogens on the Risk of Cancer Development

Xenoestrogens (XEs) are a group of exogenous substances that may interfere with the functioning of the endocrine system. They may mimic the function of estrogens, and their sources are plants, water or dust, plastic, chemical agents, and some drugs. Thus, people are highly exposed to their actions. Together with the development of industry, the number of XEs in our environment increases. They interact directly with estrogen receptors, disrupting the transmission of cellular signals. It is proven that XEs exhibit clinical application in e.g., menopause hormone therapy, but some studies observed that intense exposure to XEs leads to the progression of various cancers. Moreover, these substances exhibit the ability to cross the placental barrier, therefore, prenatal exposure may disturb fetus development. Due to the wide range of effects resulting from the biological activity of these substances, there is a need for this knowledge to be systematized. This review aims to comprehensively assess the environmental sources of XEs and their role in increasing cancer risk, focusing on current evidence of their biological and pathological impacts.

Ochratoxin A in food commodities: A review of occurrence, toxicity, and management strategies

Ochratoxin A (OTA) is a potent mycotoxin produced by species of Aspergillus and Penicillium that contaminate agricultural products and pose significant health risks to both humans and animals. This review examines the mechanisms of OTA toxicity, its occurrence in various food commodities, and the implications for public health and trade. Literature pertaining to OTA was sourced from Google Scholar, covering the period from 2004 to 2024. OTA exposure is linked to multiple adverse health effects, including teratogenicity, immunotoxicity, and hepatotoxicity, with a primary impact on kidney function, and it is classified as a possible human carcinogen (Group 2B). Its toxic effects are attributed to several mechanisms, including lipid peroxidation, inhibition of protein synthesis, DNA damage, oxidative stress, and mitochondrial dysfunction. Notable findings included the presence of OTA in 46.7 % of cocoa products in Turkey, 32 % of cocoa samples in Côte d'Ivoire exceeding the OTA threshold of 2 μg/kg, and 91.5 % of ready-to-sell cocoa beans in Nigeria testing positive for OTA. Coffee beans are particularly susceptible to OTA contamination, which underscores the need for vigilant monitoring. Additionally, OTA contamination impacts agricultural productivity and food safety, leading to significant economic consequences, particularly in regions reliant on exports, such as cocoa and coffee. Several countries regulate the OTA levels in food products to safeguard public health. However, these regulations can impede trade, particularly in countries with high levels of contamination. Balancing regulatory compliance with economic viability is crucial for affected nations. Current strategies for managing OTA include improved agronomic practices, such as the use of biocontrol agents for pest management, enhanced storage conditions to prevent mould growth, and the implementation of detoxification techniques to reduce OTA levels in food products. Despite these strategies, OTA remains a significant threat to public health and the agricultural economy worldwide. The complexity of contamination in food products requires robust prevention, control, and management strategies to mitigate its impact. Continuous research and regulatory initiatives are essential for safeguarding consumers and ensuring food safety.

Assessment of dietary exposure and levels of mycotoxins in sorghum from Niger State of Nigeria

This study reports levels of mycotoxins in sorghum from Niger State, Nigeria, and provides a comprehensive assessment of their potential health risks by combining mycotoxin levels and dietary exposure assessment. A total of 240 samples of red and white sorghum were collected from both stores and markets across four microclimatic zones. Fungal species were identified using a dilution plate method. Aflatoxins (AFs), deoxynivalenol, nivalenol, and ochratoxin (OTA) were quantified using HPLC, whereas cyclopiazonic acid, fumonisins (FUMs) and zearalenone were quantified using ELISA. A. flavus and A. fumigatus were dominant fungal species followed by F. verticilloides, A. oryzae and P. verrucosum. Aflatoxins (mean: 29.97 µg/kg) were detected in all samples, whereas OTA (mean: 37.5 µg/kg) and FUMs (mean: 3269.8 µg/kg) were detected in 72% and 50% of the samples, respectively. Mycotoxins frequently co-occurred in binary mixtures of AFs + OTA and AFs + FUMs. Dietary exposure estimates were highest for FUMs at 230% of TDI and margin of exposures (MOEs) for both AFs and OTA (<10,000) indicating a potential risk associated with combined exposure to AFs and OTA. The Risk of hepatocellular carcinoma cases (HCC/year) attributable to AFs and OTA exposure from sorghum was estimated to be 5.99 × 105 and 0.24 × 105 cases for HBsAg + individuals based on 13.6% HBV incidence. Similarly, the HCC/year for AFs and OTA were assessed to be 3.59 × 105 and 0.14 × 105 at an 8.1% prevalence rate. Therefore, the results of this study demonstrate the high prevalence and dietary exposure to mycotoxins through sorghum consumption, raising public health and trade concerns.

The Effect of Mycotoxins and Their Mixtures on Bovine Spermatozoa Characteristics

There is growing concern about the effects of mycotoxins on mammalian reproduction. Although the effects of single mycotoxins have been well documented, the impact of their mixtures on spermatozoon quality is less known. Here, frozen-thawed semen (n = 6 bulls) was in-vitro-cultured (2 h) without (control) or with (i) a single mycotoxin [zearalenone (ZEN), ochratoxin A (OTA), toxin 2 (T2), and diacetoxyscirpenol (DAS)] in a dose-response manner; (ii) binary mixtures (OTA + T2, OTA + ZEN, OTA + DAS, ZEN + T2, DAS + T2 and ZEN + DAS); or (iii) ternary mixtures (OTA + DAS + T2, OTA + ZEN + T2, and ZEN + DAS + T2). Then, the spermatozoa quality was characterized according to its plasma- and acrosome-membrane integrity, mitochondrial membrane potential, and oxidation status by a flow cytometer. Exposure to single mycotoxins or binary mixtures did not affect the spermatozoa characteristics. However, exposure to the ternary mixtures, OTA + DAS + T2 and OTA + ZEN + T2, reduced (p < 0.05) the mitochondrial membrane potential relative to the control. In addition, OTA + ZEN + T2 increased (p < 0.05) the proportion of spermatozoa with reactive oxygen species relative to the control. The most suggested interaction effect between the mycotoxins was found to be an additive one. A synergistic interaction, mainly regarding the oxidation status of the spermatozoa, was also found between the mycotoxins. The current study sheds light on the potential risk of exposing spermatozoa to a mycotoxin mixture.

Quantification and health risk assessment of ochratoxin A in dried fruit, spices, and coffee

Ochratoxin A (OTA) is a stable toxin produced by fungal strains of Aspergillus and Penicillium. It is commonly found in a variety of food products, including dried fruit, coffee, and spices, raising concerns about their safety. This study was aimed to quantify OTA levels in different food products using HPLC with fluorescence detection. The pre-treatment process was optimised by employing immunoaffinity columns with Tween 20 to effectively remove interfering substances. An analytical method was developed, validated, and applied for OTA analysis in dried fruit, spices, and coffee samples. The validation procedure included determining detection and quantification limits, linearity, precision, and accuracy, as per the criteria specified by AOAC International. The validated method was successfully applied for OTA analysis in the selected food samples. Furthermore, health risk assessment was conducted based on the average intake and body weight of the Korean population. From the results, concentrations of OTA in the samples were found to be very low and therefore concluded not to pose significant threats to consumer health.

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.

Foodborne Diseases Due to Underestimated Hazard of Joint Mycotoxin Exposure at Low Levels and Possible Risk Assessment

The subject of this review paper is to evaluate the underestimated hazard of multiple mycotoxin exposure of animals/humans for the appearance of foodborne ailments and diseases. The significance of joint mycotoxin interaction in the development of foodborne diseases is discussed, and appropriate conclusions are made. The importance of low feed/food levels of some target mycotoxins co-contaminations in food and feedstuffs for induction of target foodborne mycotoxicoses is also studied in the available literature. The appropriate hygiene control and the necessary risk assessment in regard to possible hazards for animals and humans are also discussed, and appropriate suggestions are made. Some internationally recognized prophylactic measures, management of the risk, and the necessity of elaboration of new international regulations in regard to the maximum permitted levels are also carefully discussed and analysed in the cases of multiple mycotoxin contaminations. The necessity of harmonization of mycotoxin regulations and control measures at international levels is also discussed in order to facilitate food trade between the countries and to ensure global food safety.

Label-free electrochemical immunosensor for Ochratoxin a detection in coffee samples

Ochratoxin A (OTA) is a nephrotoxic and carcinogenic mycotoxin frequently found in coffee, which directly impacts human health and the economy of many countries. For this reason, there has been a growing need for simple and sensitive tools for the on-site detection of this mycotoxin. In this study, we developed a label-free impedimetric immunosensor to detect OTA. The biosensor was built on a thin-film gold electrode evaporated on glass substrtes, modified with a self-assembled cysteamine monolayer and anti-OTA antibodies. Atomic force microscopy and Microspectroscopy RAMAN confirmed the successful functionalization of the electrodes. The biosensor performance was evaluated by electrochemical impedance spectroscopy and the measurements indicated a linear relationship between the change in the impedance values and the OTA concentration in the range from 0.5 to 100 ng mL^-1 with a limit of detection of 0.15 ng mL^-1. The biosensor was highly selective and did not suffer matrix interference when analyzed in coffee samples. Furthermore, considering the small sample volumes, the short time required for analysis, and the possibility of miniaturization, the developed biosensor represents a promising analytical device for on-site coffee quality analyses.

Maternal exposure to multiple mycotoxins and adverse pregnancy outcomes: a prospective cohort study in rural Bangladesh

There is limited and inconsistent evidence, primarily from cross-sectional studies, linking mycotoxins to adverse birth outcomes. This study investigates the potential role of maternal dietary exposure to multiple mycotoxins in the development of several adverse pregnancy and birth outcomes. We analyzed data from 436 singleton pregnancies enrolled in a prospective cohort study in the rural Habiganj district, Bangladesh, between July 2018 and November 2019. Thirty-five urinary mycotoxin biomarkers were quantified using liquid chromatography coupled with tandem mass spectrometry and used to estimate dietary mycotoxin exposure. Multivariable regression models, adjusted for potential confounding and clustering, were fitted to assess the associations between maternal exposure to frequently occurring mycotoxins (ochratoxin A-OTA, citrinin- CIT, and Deoxynivalenol- DON) and pregnancy loss, preterm birth (PTB), low birth weight (LBW), born small-for-gestational-age (SGA) and small-vulnerable newborn. The results indicate that only in 16 of 436 pregnancies (4%) were urine samples free from all investigated mycotoxins. Biomarkers for six major mycotoxins were detected in the urine samples. OTA (95%), CIT (61%), and DON (6%) were most frequently detected, with at least two mycotoxins co-occurring in the majority of women (63%). There was evidence that maternal dietary intake of OTA was associated with higher odds of having an LBW baby, with the odds increasing in a dose-dependent manner. We found no evidence of associations between pregnancy loss, PTB, SGA, small-vulnerable newborns, and maternal dietary exposure to OTA, CIT, and DON, albeit with large confidence intervals, so findings are consistent with protective as well as large harmful effects. Exposure to multiple mycotoxins during pregnancy is widespread in this rural community and represents a health risk for mothers and babies. Tailored public health policies and interventions must be implemented to reduce mycotoxin exposure to the lowest possible level.

Apoptotic Janus-faced mycotoxins against thoracal and breast metastases

Abdominal organs (liver, kidney, spleen) are frequent targets of cancer cell invasion but their primary tumours are less known for their metastatic potential to other organs e.g. to the breast. Despite the known connection of the pathogenesis from breast cancer to liver metastasis, the study of the spread in the opposite direction has been neglected. The notion that breast cancer could be a metastasis besides being a primary tumour is based on rodents' tumour models upon implantation of tumour cells under the capsule of the kidney or under the Glisson's capsule of the liver of rats and mice. Tumour cells develop into a primary tumour at the site of subcutaneous implantation. The metastatic process starts with peripheral disruptions of blood vessels near the surface of primary tumours. Tumour cells released into the abdomen cross the apertures of the diaphragm, enter the thoracal lymph nodes and accumulate in parathymic lymph nodes. Abdominal colloidal carbon particles injected into the abdomen faithfully mimicked the migration of tumour cells and deposited in parathymic lymph nodes (PTNs). An explanation is provided why the connection between abdominal tumours and mammary tumours escaped attention, notably, parathymic lymph nodes in humans were referred to as internal mammary or parasternal lymph nodes. The apoptotic effect of Janus-faced cytotoxins is suggested to provide a new approach against the spread of abdominal primary tumours, and metastatic development.

Toxico-pathological effects of ochratoxin A and its diastereoisomer under in ovo conditions and in vitro evaluation of the toxicity of these toxins against the embryo Gallus gallus fibroblast cell line

Herein, we conducted a comparative study on the embryotoxicity of ochratoxin A (OTA) and its diastereomer 2'R-ochratoxin A (2'R-OTA) under in ovo conditions, as well as assess the in vitro embryotoxicity of these substances together with ochratoxin B and α-ochratoxin, using chicken (Gallus gallus domesticus) embryo cell lines. In ovo tests involved egg incubation of 8 different groups (i.e., control "0"-no puncture or injection (standard incubation); "00"-punctured eggs without injection; "OTA 0.25," "OTA 0.50," "OTA 0.75," "2'R-OTA 0.25," "2'R-OTA 0.50," "2'R-OTA 0.75"-eggs containing OTA or 2'R-OTA at 0.25, 0.50, and 0.75 µg/egg concentration, respectively). The results confirmed OTA's impact on early and late embryo mortality, where chick hatchability decreased with increasing toxin dosage. Both OTA and 2'R-OTA demonstrated embryotoxicity, however, in the case of the highest OTA diastereomer dose, nearly 11% higher chick hatchability was observed compared with the group that received OTA. 2'R-OTA dosage did not reduce parameters chick quality compared to chicks hatched from control group eggs. OTA concentrations were higher than 2'R-OTA detected in chicken organs such as liver and kidney, whereas 2'R-OTA concentrations were higher in blood serum and heart. The presented studies highlighted the differences in the ability to accumulate toxins in certain organs, which, to a certain extent, may affect the potential toxicity on individual organs. Additionally, during in vitro tests, when assessing the cytotoxic effects of OTA and its analogues toward the chicken embryonic cell line in an MTT assay, the cell metabolic activity was inhibited to a comparable extent at 27-times higher concentration of 2'R-OTA than OTA (0.24 µM). Also, comparably lower toxicity was attributed to the remaining OTA derivatives.

Antioxidant and antiapoptotic effects of quercetin against ochratoxin A-induced nephrotoxicity in broiler chickens

The mycotoxin ochratoxin A (OTA) is produced by the fungi Aspergillus and Penicillium. The flavonoid quercetin (QUE) is distinguished by its antioxidant, anti-inflammatory, and antiapoptotic properties. This study was designed to determine whether QUE can protect broiler chickens against OTA-induced nephrotoxicity. Forty broiler chicks were randomly divided into four equal groups: control, OTA, QUE, and OTA + QUE. For 6 weeks, OTA (0.5 mg/kg) and/or QUE (0.5 g/kg) were added to the diet of chickens. The results demonstrated that OTA exposure increased serum levels of creatinine, uric acid, and blood urea nitrogen. OTA exposure also increased renal malondialdehyde content but decreased renal antioxidants. OTA-exposed chickens exhibited multiple pathological kidney lesions. Moreover, OTA exposure induced apoptosis in renal tissue, which was manifested by the up-regulation of proapoptotic genes and down-regulation of antiapoptotic genes via the suppression of the PI3K/AKT pathway. In addition, coadministration of QUE and OTA mitigated most of these nephrotoxic effects.

The Neurotoxic Effect of Ochratoxin-A on the Hippocampal Neurogenic Niche of Adult Mouse Brain

Ochratoxin A (OTA) is a common secondary metabolite of Aspergillus ochraceus, A. carbonarius, and Penicillium verrucosum. This mycotoxin is largely present as a contaminant in several cereal crops and human foodstuffs, including grapes, corn, nuts, and figs, among others. Preclinical studies have reported the involvement of OTA in metabolic, physiologic, and immunologic disturbances as well as in carcinogenesis. More recently, it has also been suggested that OTA may impair hippocampal neurogenesis in vivo and that this might be associated with learning and memory deficits. Furthermore, aside from its widely proven toxicity in tissues other than the brain, there is reason to believe that OTA contributes to neurodegenerative disorders. Thus, in this present in vivo study, we investigated this possibility by intraperitoneally (i.p.) administering 3.5 mg OTA/kg body weight to adult male mice to assess whether chronic exposure to this mycotoxin negatively affects cell viability in the dentate gyrus of the hippocampus. Immunohistochemistry assays showed that doses of 3.5 mg/kg caused a significant and dose-dependent reduction in repetitive cell division and branching (from 12% to 62%). Moreover, the number of countable astrocytes (p < 0.001), young neurons (p < 0.001), and mature neurons (p < 0.001) negatively correlated with the number of i.p. OTA injections administered (one, two, three, or six repeated doses). Our results show that OTA induced adverse effects in the hippocampus cells of adult mice brain tissue when administered in cumulative doses.

The Secondary Metabolites and Biosynthetic Diversity From Aspergillus ochraceus

Aspergillus ochraceus, generally known as a food spoilage fungus, is the representative species in Aspergillus section Circumdati. A. ochraceus strains are widely distributed in nature, and usually isolated from cereal, coffee, fruit, and beverage. Increasing cases suggest A. ochraceus acts as human and animal pathogens due to producing the mycotoxins. However, in terms of benefits to mankind, A. ochraceus is the potential source of industrial enzymes, and has excellent capability to produce diverse structural products, including polyketides, nonribosomal peptides, diketopiperazine alkaloids, benzodiazepine alkaloids, pyrazines, bis-indolyl benzenoids, nitrobenzoyl sesquiterpenoids, and steroids. This review outlines recent discovery, chemical structure, biosynthetic pathway, and bio-activity of the natural compounds from A. ochraceus.

Diagnostic Strategies for Urologic Cancer Using Expression Analysis of Various Oncogenic Surveillance Molecules—From Non-Coding Small RNAs to Cancer-Specific Proteins

Urinary-tract-related tumors are prone to simultaneous or heterogeneous multiple tumor development within the primary organ. Urologic tumors have a very high risk of recurrence in the long and short term. This may be related to the disruption of homeostasis on the genetic level, such as the induction of genetic mutations due to exposure to various carcinogenic factors and the disruption of cancer suppressor gene functions. It is essential to detect the cancer progression signals caused by genetic abnormalities and find treatment therapies. In this review, we discuss the usefulness of tumor-expressing clinical biomarkers for predicting cancer progression. Furthermore, we discuss various factors associated with disturbed intracellular signals and those targeted by microRNAs, which are representative of non-coding small RNAs.

Genotoxic effects of the ochratoxin A (OTA), its main metabolite (OTα) per se and in combination with fumonisin B1 in HepG2 cells and human lymphocytes

Ochratoxin A (OTA) and fumonisin B₁ (FB₁) are mycotoxins distributed in a wide variety of foods for human or animal consumption and are classified as possible carcinogens for humans. This study aimed to evaluate the cytotoxic, cytostatic and genotoxic effects of OTA and its main metabolite, ochratoxin α (OTα), FB₁ and three combinations of OTA and FB₁ at moderate and environmental doses. Cell viability was evaluated through MTT assay and the trypan blue exclusion method. The cytostatic and genotoxic effects were evaluated through the cytokinesis-block micronucleus assay. The results showed synergistic time- and concentration-dependent cytotoxic effects of one of the combinations of OTA and FB₁. In contrast, significant differences were observed in the micronuclei (MN) frequency from OTA, OTα and coexposure of OTA + FB₁. Some of these combinations increased the frequency of nuclear buds, nucleoplasmic bridges, donut-shaped nuclei, necrotic and apoptotic cells and MN in mononucleated cells. In conclusion, OTA and its main metabolite OTα, as well as the co-exposure of OTA and FB₁, cause stable DNA damage at environmentally relevant concentrations, which was greater in metabolically competent cells. More studies are needed to understand the chemical interactions that occur due to the joint presence of mycotoxins, which occurs commonly.

Development of a novel liquid crystal Apta-sensing platform using P-shape molecular switch

Described herein is a liquid crystal (LC)-based aptasensor via employing the reorientation of LC triggered by the conformational changes of a P-shaped DNA structure. The structure consists of a short linker sequence as an immobilizer probe with ability to hybridize with the central part of the intact aptamer (Apt) sequence and an Apt terminal-locker (ATL) strand with complementary segments of the Apt terminal fragments. Bindings of two arm segments of the Apt sequence with the ATL strand enforces it to form a P-shaped configuration on the sensing platform. The selective interaction between the Apt strand and OTA leads to the disassembly of the Apt-ATL hybrid, collapse of the P-shaped structure, and consequently, transition of the optical appearance of the aptasensor texture. Determination of Ochratoxin A (OTA) in foods is an urgent demand in attempt to minimize food safety risks. To demonstrate the feasibility of our aptasensing design, the OTA specific aptamer was selected as a model. The developed LC aptasensor possesses a wide linear range from 0.01 aM to 100 pM, ultra-low limit of detection (LOD) of 0.0078 aM, and quantitative recoveries of 91-103.51% for OTA in rice and grape juice samples. This study proposes a novel and universal LC-based platform for facile, ultra-sensitive, and precision sensing of hazardous analytes in real samples.

Janus-Faced Molecules against Plant Pathogenic Fungi

The high cytotoxicity of the secondary metabolites of mycotoxins is capable of killing microbes and tumour cells alike, similarly to the genotoxic effect characteristic of Janus-faced molecules. The "double-edged sword" effect of several cytotoxins is known, and these agents have, therefore, been utilized only reluctantly against fungal infections. In this review, consideration was given to (a) toxins that could be used against plant and human pathogens, (b) animal models that measure the effect of antifungal agents, (c) known antifungal agents that have been described and efficiently prevent the growth of fungal cells, and (d) the chemical interactions that are characteristic of antifungal agents. The utilization of apoptotic effects against tumour growth by agents that, at the same time, induce mutations may raise ethical issues. Nevertheless, it deserves consideration despite the mutagenic impact of Janus-faced molecules for those patients who suffer from plant pathogenic fungal infections and are older than their fertility age, in the same way that the short-term cytotoxicity of cancer treatment is favoured over the long-term mutagenic effect.

Cell Proliferation and Tumor Induction by Ochratoxin A in Mouse Skin and Evaluation of Cyclin D1 and Cyclooxygenase-2 Expressions

Motivation. Skin tumor is one of the frequent occurring forms of cancer where 2-3 million instances are reported worldwide. The ultraviolet rays along with the environmental pollutants and other contaminants can be the potential factors of skin cancer. Cyclin D1 is a serious gene included in controlling the development through the G1 phase of the cell cycle. Ochratoxin A (OTA) is a naturally existing mycotoxin which majorly occurs in food like grains. It is responsible for producing the splitting of single-strand DNA and is identified to be cancer-causing. It is established as a critical risk factor towards reproductive health in both males and females. Methodology. A single dose of ochratoxin A was used for topical application for assessment of skin tumor promotion activity, hyperplasia, ornithine decarboxylase activity, and expression of cyclin D1 and COX-2 in mouse skin. Enhancement in the synthesis of DNA, activation of the epidermal growth factor receptor, and overexpression of cyclin D1 and COX-2 were noted. Primary murine keratinocyte cell culture was cultured with Waymouth's medium. Western blot analysis and real-time polymerase chain reaction (RT-PCR) were used to detect the expression of cyclin D1 and COX-2. Chromatin immunoprecipitation (ChIP) assays were used to the association between AP-1 transcription and nuclear factor-kappaB (NF-κB) with COX-2 and cyclin D1 promoters. Results. The results found that cyclin D1 and COX-2 were responsible for stimulating OTA-induced PMK proliferation and hyperplasia. Implications. EGFR-mediated pathways were also responsible for tumor promotion due to OTA.

Mannan Oligosaccharide Could Attenuate Ochratoxin A-Induced Immunosuppression with Long-Time Exposure Instead of Immunostimulation with Short-Time Exposure

Our previous study showed that ochratoxin A (OTA), one of the most common mycotoxins in feed, could induce immunosuppression with long-time exposure but immunostimulation with short-time exposure. However, limited studies for the control of OTA-induced two-way immune toxicity were carried out. This study explored the effects of mannan oligosaccharide (MOS), a glucomannoprotein complex with immunoregulatory capability derived from the yeast cell wall, on OTA-induced immune toxicity and its underlying mechanisms. Surprisingly, the results showed that MOS significantly attenuated immunosuppression induced by long-time OTA treatment but did not provide protection against immunostimulation induced by short-time OTA treatment on porcine alveolar macrophages (PAMs), as demonstrated by the expressions of inflammatory cytokines and the capability of migration and phagocytosis. Further, MOS increased the OTA-inhibited autophagy level and the JNK phosphorylation level on PAMs with long-time OTA treatment. In addition, the inhibition of autophagy by 3-MA or the inhibition of JNK phosphorylation by SP600125 could partly block the protective effects of MOS on OTA-induced immunosuppression. Importantly, the inhibition of JNK phosphorylation down-regulated the MOS-promoted autophagy level. In conclusion, MOS could attenuate OTA-induced immunosuppression with short-time exposure on PAMs through activating JNK-mediated autophagy but had no significant effects on OTA-induced immunostimulation with short-time exposure. Our study provides new insights into the application of MOS as an immunoregulator against mycotoxin-induced immune toxicity.

A Systematic Review to Compare Chemical Hazard Predictions of the Zebrafish Embryotoxicity Test With Mammalian Prenatal Developmental Toxicity

Originally developed to inform the acute toxicity of chemicals on fish, the zebrafish embryotoxicity test (ZET) has also been proposed for assessing the prenatal developmental toxicity of chemicals, potentially replacing mammalian studies. Although extensively evaluated in primary studies, a comprehensive review summarizing the available evidence for the ZET's capacity is lacking. Therefore, we conducted a systematic review of how well the presence or absence of exposure-related findings in the ZET predicts prenatal development toxicity in studies with rats and rabbits. A two-tiered systematic review of the developmental toxicity literature was performed, a review of the ZET literature was followed by one of the mammalian literature. Data were extracted using DistillerSR, and study validity was assessed with an amended SYRCLE's risk-of-bias tool. Extracted data were analyzed for each species and substance, which provided the basis for comparing the 2 test methods. Although limited by the number of 24 included chemicals, our results suggest that the ZET has potential to identify chemicals that are mammalian prenatal developmental toxicants, with a tendency for overprediction. Furthermore, our analysis confirmed the need for further standardization of the ZET. In addition, we identified contextual and methodological challenges in the application of systematic review approaches to toxicological questions. One key to overcoming these challenges is a transition to more comprehensive and transparent planning, conduct and reporting of toxicological studies. The first step toward bringing about this change is to create broad awareness in the toxicological community of the need for and benefits of more evidence-based approaches.

Ochratoxin A levels in serum of Polish dialysis patients with chronic renal failure

Ochratoxin A (OTA) is a mycotoxin produced by the fungi Aspergillus and Penicillium. It occurs naturally in many products of plant origin and in animals because of the carry-over from feed to meat or milk. Ochratoxin A has nephrotoxic, carcinogenic, hepatotoxic, neurotoxic, and genotoxic properties. Data on ochratoxin concentrations in blood or serum from patients with different kidney disorders are available for several European countries, as well as for Africa and Asia. In this study, we determined OTA concentrations in serum samples from chronic renal failure patients receiving dialysis and from healthy controls, collected in central Poland. Ochratoxin A was analyzed after extraction and purification using immunoaffinity columns by liquid chromatography with fluorescence detection (limit of quantification: 0.1 ng/mL) in 88 patients and 16 healthy volunteers. The dialysis group consisted of 40 women and 48 men aged between 23 and 85 years. The mean OTA concentrations were 0.75 ng/mL (maximum 2.78 ng/mL) in dialysis patients and 0.70 ng/mL (maximum 1.44 ng/mL) in healthy controls. The mean concentrations in patients treated by dialysis were 0.76 and 0.74 ng/ml for women and men, respectively (maximum 2.53 ng/ml for women and 2.78 ng/ml for men). Statistical analysis using Student's t-test showed no statistically significant differences between the control group (non-dialysis patients) and all dialysis patients.

Ochratoxin A induces ERK1/2 phosphorylation-dependent apoptosis through NF-κB/ERK axis in human proximal tubule HK-2 cell line

Ochratoxin A (OTA) is a food contaminant mycotoxin with hazardous effects on human and animal health, primarily affecting the kidneys. OTA's mode of action is not well understood. OTA activates both MAPK/ERK and PI3K/Akt signaling pathways, which play role in apoptosis and cell survival, respectively. OTA is also known to induce toxicity by activating the NF-κB pathway in immune cells. However, its role in determining the cell fate upon OTA exposure in a human kidney cell line (HK-2) has not been fully explored. We made use of pharmacological inhibition of NF-κB to define its role in viability of OTA-treated HK-2 cells. We show that OTA-induced p65 NF-κB subunit translocation into the nucleus in a time-dependent manner using both Western blotting and immunofluorescence (IF). We also document the DNA-binding and reporter gene expression activities of NF-κB by electrophoretic mobility shift (EMSA) and luciferase reporter assays, respectively. Our results indicate that, following 6 h of exposure, OTA fully activates NF-κB pathway and its downstream effectors in HK-2 cells. In addition, Bay11-7085 treatment causes attenuation of the relative levels of OTA-mediated ERK1/2 phosphorylation, suggesting a cross-talk between NF-κB and the MAPK/ERK pathway. Critically, co-treatment of HK-2 cells with OTA and Bay11-7085 leads to the inhibition of OTA-induced apoptosis in a time-dependent manner. Our results support a robust association between NF-κB and the MAPK/ERK pathways in the modulation of apoptotic effects of OTA in HK-2 cells.

Mycotoxins Affecting Animals, Foods, Humans, and Plants: Types, Occurrence, Toxicities, Action Mechanisms, Prevention, and Detoxification Strategies-A Revisit

Mycotoxins are produced by fungi and are known to be toxic to humans and animals. Common mycotoxins include aflatoxins, ochratoxins, zearalenone, patulin, sterigmatocystin, citrinin, ergot alkaloids, deoxynivalenol, fumonisins, trichothecenes, Alternaria toxins, tremorgenic mycotoxins, fusarins, 3-nitropropionic acid, cyclochlorotine, sporidesmin, etc. These mycotoxins can pose several health risks to both animals and humans, including death. As several mycotoxins simultaneously occur in nature, especially in foods and feeds, the detoxification and/or total removal of mycotoxins remains challenging. Moreover, given that the volume of scientific literature regarding mycotoxins is steadily on the rise, there is need for continuous synthesis of the body of knowledge. To supplement existing information, knowledge of mycotoxins affecting animals, foods, humans, and plants, with more focus on types, toxicity, and prevention measures, including strategies employed in detoxification and removal, were revisited in this work. Our synthesis revealed that mycotoxin decontamination, control, and detoxification strategies cut across pre-and post-harvest preventive measures. In particular, pre-harvest measures can include good agricultural practices, fertilization/irrigation, crop rotation, using resistant varieties of crops, avoiding insect damage, early harvesting, maintaining adequate humidity, and removing debris from the preceding harvests. On the other hand, post-harvest measures can include processing, chemical, biological, and physical measures. Additionally, chemical-based methods and other emerging strategies for mycotoxin detoxification can involve the usage of chitosan, ozone, nanoparticles, and plant extracts.

Two-color, ultra-sensitive fluorescent strategy for Ochratoxin A detection based on hybridization chain reaction and DNA tweezers

A two-color fluorescent DNA tweezers was developed for ultrasensitive detection of Ochratoxin A (OTA) based on hairpin-locked aptamer and hybridization chain reaction (HCR) amplification strategy. OTA can bind with hairpin-locked aptamer and then trigger the HCR reaction to produce a long double-strand DNA. The side-chains of the long duplex can separately hybridize with the two locker sequences of DNA tweezer, causing the opening of DNA tweezer and the recovery of two-color fluorescent signals. It shows a good linear range from 0.02 to 0.8 ppb with limit of detection of 0.006 ppb for FAM and 0.014 ppb for Cy5, which is beyond the requirement of actual application. In addition, the two-color fluorescent strategy can greatly reduce the false positive rate. It shows excellent performance for detection of OTA in practical food sample.

Rat Tumour Histopathology Associated with Experimental Chronic Dietary Exposure to Ochratoxin A in Prediction of the Mycotoxin's Risk for Human Cancers

Mammalian animal toxicity of ochratoxin A (OTA) has focused largely in the past half-century on pigs because of initial recognition of it as a principal cause of intermittent growth suppression and renal disease caused by mouldy feed. Subsequent classical toxicology has used laboratory rodents because renal pathology in pigs raised questions concerning possible involvement in the human idiopathic bilateral renal atrophy of Balkan endemic nephropathy for which OTA was a focus of attention for human nephropathy through 1980s and into 2000s. Emphasis on human nephropathy has more recently concerned the plant metabolite aristolochic acid. Recognition that agricultural management can often minimise food and feed-stuff spoilage by OTA-producing Aspergilli and Penicillia has moderated some of the risks for animals. Legislation for human food safety combined with sophisticated analysis generally provides safety in the developed world. Chronic experimental exposure of male rats, in the absence of clinical dis-ease, specifically causes renal cancer. The possibility of this as a unique model for the human has generated considerable experimental evidence which may be more directly relevant for carcinogenesis in the complex kidney than that obtained from biochemical toxicities in vitro. Nevertheless, there does not appear to be any case of human renal or urinary tract cancer for which there is verified etiological proof for causation by OTA, contrary to much claim in the literature. To contribute to such debate, histopathology review of OTA/rat renal cancers, augmented where appropriate by immune profiles, has been completed for all remaining tumours in our research archive. Overall consistency of positivity for vimentin, is matched with occasional positives either for CD10 or the cytokeratin MNF 116. The current situation is discussed. Suggestion that OTA could cause human testicular cancer has also been challenged as unsupported by any experimental findings in rats, where the Leydig cell tumour immune profile does not match that of human germ cell neoplasms.

Saccharomyces cerevisiae Yeast-Based Supplementation as a Galactagogue in Breastfeeding Women? A Review of Evidence from Animal and Human Studies

Perceived insufficient milk production (PIM) adversely affects breastfeeding duration. Women sometimes use galactagogues with the intent to increase breast milk production and support lactation. Saccharomyces cerevisiae yeast-based supplement (SCYS) is an inactive form of Saccharomyces cerevisiae yeast (SCY) either obtained from the fermentation process or grown on molasses. Anecdotal evidence suggests SCYS is a galactagogue. SCYS is promoted on the internet as a galactagogue in various forms and doses. Dietary supplementation with SCYS during gestation and lactation significantly increases milk yield in ruminants. No human study has evaluated efficacy of SCYS as a galactagogue. SCYS is rich in B vitamins, beta-glucan, mannan oligosaccharides and bioavailable chromium; these may impact breast milk production or composition, thus may alleviate PIM. The safety of taking SCYS during lactation is not well studied. Studies have reported contamination of SCYS with ochratoxin A (OTA) as well as minor side effects from SCYS. Studies are needed to evaluate the efficacy of SCYS on breast milk production and composition and to assess the safety of taking SCYS during lactation in humans.

Nrf2: a main responsive element in cells to mycotoxin-induced toxicity

Nuclear factor erythroid 2-like 2 (Nrf2) is a transcription factor participating in response to cellular oxidative stress to maintain the redox balance. Generation of reactive oxygen species (ROS) and, in consequence, oxidative stress, are physiological as well as pathological processes which take place in almost all types of cells. Nrf2, in response to oxidative stress, activates expression and production of antioxidant enzymes to remove free radicals. However, the role of Nrf2 seems to be more sophisticated and its increased expression observed in cancer cells allows to draw a conclusion that its role is tissue—and condition—dependent. Interestingly, Nrf2 might also play a crucial role in response to environmental factors like mycotoxins. Thus, the aim of the study is to review the role of Nrf2 in cells exposed to most common mycotoxins to check if the Nrf2 signaling pathway serves as the main response element to mycotoxin-induced oxidative stress in human and animal cells and if it can be a target of detoxifying agents.

Ochratoxin A affects oocyte maturation and subsequent embryo developmental dynamics in the juvenile sheep model

The genotoxic and nephrotoxic mycotoxin Ochratoxin A (OTA) has also been reported to have adverse effects on oocyte maturation and embryo development. Previous studies on the effects of OTA on female fertility have used micromolar concentrations, but no information is available to date on effects in a more relevant nanomolar range. This study used a juvenile sheep model to evaluate the effects of oocyte exposure to low levels of OTA on maturation, fertilization, and embryo development. Further, it was investigated whether different mechanisms of action of OTA could be responsible for varying toxic effects at different levels of exposure. Cumulus-oocyte-complexes (COCs) were exposed to 10 μmol/L-0.1 nmol/L OTA during in vitro maturation and evaluated for cumulus viability, oocyte maturation, and bioenergetic/oxidative status. COCs were subjected to in vitro fertilization, embryo culture, and embryo quality assessment via morphology, viability, bioenergetic/oxidative status, and time-lapse monitoring. At micromolar concentrations, OTA induced cytotoxic effects, by reducing cumulus expansion and oocyte maturation. OTA altered temporospatial dynamics of zygote pronuclear formation and embryo morphokinetics. Blastocysts, even morphologically normal, were found to undergo collapse events, which were probably related to boosted blastocyst mitochondrial activity. At nanomolar concentrations, OTA did not affect COC morpho-functional parameters, but impaired oocyte ability to prevent polyspermy and increased blastocyst apoptosis. In conclusion, in the female germ cell, cytotoxic nonspecific effects characterize OTA-induced toxicity at high exposure levels, whereas fine tuning-mode effects, not associated with altered cell viability and integrity, characterize OTA toxic action at low levels.

Assessment of serum aflatoxin B1 levels in neonatal jaundice with glucose-6-phosphate dehydrogenase deficiency: a preliminary study

Aflatoxin (AF) contamination of food products is still a major health issue globally. Prior studies suggest that exposure to AFs during pregnancy has harmful fetal outcomes. This preliminary study was designed to assess serum AFB₁ levels in neonatal jaundice (NNJ) secondary to glucose-6-phosphate dehydrogenase (G6PD) deficiency. Twenty-four full-term neonates with hemolytic jaundice secondary to G6PD deficiency were enrolled in the study. Erythrocyte G6PD status was assessed colorimetrically, and serum aflatoxin B₁ (AFB₁) concentrations were measured by high-performance liquid chromatography. The results revealed that AFB₁ was detected in 58% (14/24) of the studied newborns while detected in 75% (18/24) of their mothers. AFB₁ positive cases had a highly significantly lower birthweight and G6PD activity (P = 0.001, each). Birthweight (r = - 0.574, P = 0.032) and G6PD activity (r = - 0.585, P = 0.028) negatively correlated with serum AFB₁ levels while serum alanine aminotransferase activity positively correlated with serum AFB₁ levels (r = 0.536, P = 0.048). Maternal AFB₁ exposure is associated with adverse birth outcomes as verified by the low birthweight and the evident decline in the activity of G6PD enzyme with the resultant hemolytic NNJ.

Natural Occurrence of Ochratoxin A in Blood and Milk Samples from Jennies and Their Foals after Delivery

An assessment of the natural ochratoxin A (OTA) exposure of seven Martina Franca jennies was carried out by analyzing blood and milk samples collected close to and after delivery. A total of 41 and 34 blood samples were collected from jennies and foals, respectively, and analyzed by ELISA. A total of 33 milk samples were collected from jennies and analyzed by the HPLC/FLD method based on IAC clean-up. Furthermore, 53 feed samples were collected from January to September and analyzed by a reference method (AOAC Official Method No. 2000.03) for OTA content. Feed samples showed OTA levels up to 2.7 ng/g with an incidence of 32%, while the OTA incidence rate in jennies' blood samples was 73%, with a median value of 97 ng/L and concentrations ranging from Collapse

Key Words

• foals
• jennies
• milk blood
• ochratoxin A
• placental transfer
• pregnancy

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MESH Headings

• Animal Feed/analysis
• Animals
• Environmental Monitoring
• Equidae/blood
• Female
• Food Contamination/analysis
• Milk/chemistry
• Ochratoxins/analysis
• Ochratoxins/blood
• Seasons

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Affiliation(s)

Vincenzo Lippolis Institute of Sciences of Food Production (ISPA), National Research Council of Italy (CNR), 70125 Bari, Italy; (V.L.); (S.A.); (M.P.); (S.C.); (E.M.)
Shafaq Asif Institute of Sciences of Food Production (ISPA), National Research Council of Italy (CNR), 70125 Bari, Italy; (V.L.); (S.A.); (M.P.); (S.C.); (E.M.) Faculty of Veterinary Medicine, University of Teramo, 64100 Teramo, Italy; (I.D.A.); (D.R.)
Michelangelo Pascale Institute of Sciences of Food Production (ISPA), National Research Council of Italy (CNR), 70125 Bari, Italy; (V.L.); (S.A.); (M.P.); (S.C.); (E.M.)
Salvatore Cervellieri Institute of Sciences of Food Production (ISPA), National Research Council of Italy (CNR), 70125 Bari, Italy; (V.L.); (S.A.); (M.P.); (S.C.); (E.M.)
Erminia Mancini Institute of Sciences of Food Production (ISPA), National Research Council of Italy (CNR), 70125 Bari, Italy; (V.L.); (S.A.); (M.P.); (S.C.); (E.M.)
Angelo Peli Department of Veterinary Medical Sciences, Alma Mater Studiorum—University of Bologna, Ozzano dell’Emilia, 40064 Bologna, Italy;
Ippolito De Amicis Faculty of Veterinary Medicine, University of Teramo, 64100 Teramo, Italy; (I.D.A.); (D.R.)
Domenico Robbe Faculty of Veterinary Medicine, University of Teramo, 64100 Teramo, Italy; (I.D.A.); (D.R.)
Fiorenza Minervini Institute of Sciences of Food Production (ISPA), National Research Council of Italy (CNR), 70125 Bari, Italy; (V.L.); (S.A.); (M.P.); (S.C.); (E.M.)

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Simultaneous detection of aflatoxin B1 and ochratoxin A in food samples by dual DNA tweezers nanomachine

a dual DNA tweezers nanomachine was developed for one-step simultaneous detection of aflatoxin B1 (AFB1) and ochratoxin A (OTA) in food samples. The dual DNA tweezers are locked by the aptamers of mycotoxins, resulting the "turn off" of fluorescent signal. In the presence of AFB1 and OTA, the aptamers can bind with their corresponding targets, resulting the "open" of DNA tweezers and the "turn on" of the fluorescent signals. The limits of detections were 3.5 × 10^-2 ppb for AFB1 and 0.1 ppb for OTA. Moreover, the applicability of the method was further demonstrated by conducting a limited survey on 5 samples collected from various sources. The recoveries of this method change from 90.0% to 110.0% for simultaneous detection of AFB1 or OTA and the RSDs vary from 4.1% to 9.2%. Detection uncertainties were within 5% (with a 95% confidence level).

Development of a horseradish peroxidase-nanobody fusion protein for visual detection of ochratoxin A by dot immunoassay

Ochratoxin A (OTA) is a common cereal mycotoxin that seriously threatens food safety and public health. Herein a horseradish peroxidase-nanobody fusion protein (HRP-Nb) retaining antibody and enzyme activity was obtained after inclusion body denaturation and renaturation and enzyme reconstitution, which served both as the primary antibody and reporter enzyme and was applied to develop a membrane-based dot immunoassay (HN-DIA) for OTA visual detection. Based on the optimal experimental conditions, the HN-DIA could be finished in 10 min with a cut-off limit of 50 μg kg-1 in rice and oat samples by eye. The HN-DIA showed high selectivity for OTA and had good accuracy and reproducibility in the recovery experiments. Spiked sample analysis results of the HN-DIA and high performance liquid chromatography (HPLC) correlated well with each other. Therefore, the proposed HN-DIA has the potential for rapid screening of OTA and other small molecule pollutants in food and the environment by naked eye.

Effects of Ochratoxin A exposure on DNA damage in porcine granulosa cells in vitro

Ochratoxin A (OTA), a feed mycotoxin, tends to impair the reproductive performance of animals. Our previous studies have demonstrated that OTA exposure inhibits porcine ovarian granulosa cell (GC) proliferation and induces their apoptosis, but the underlying toxic mechanism is still uncertain. In this study, we explored the OTA exposure on porcine GCs in vitro and found that OTA exposure inhibited the proliferation of porcine GCs and arrested cell cycle of GCs in the G2/M phase. The results based on RNA-Seq revealed that 20 μM and 40 μM OTA exposure increase DNA damage of porcine GCs in vitro. The differentially expressed genes (DEGs) of 40 μM OTA exposure were enriched in the pathways of mismatch repair, nucleotide excision repair and homologous recombination in DNA replication compared with control group and 20 μM OTA exposure group. Meanwhile, OTA exposure increased the expression levels of DNA double-strand breaks (DSBs) gene γ-H2AX, and DNA repair related genes, such as BRCA1, XRCC1, PARP1, and RAD51. Above all, our research revealed that OTA might exert deleterious effects on porcine ovarian GCs, influencing DNA repair-related biological processes and causing DNA damage response.

Regulation of taurine in OTA-induced apoptosis and autophagy

Ochratoxin A (OTA), one of the most deleterious mycotoxins, could cause a variety of toxicological effects especially nephrotoxicity in animals and humans. Taurine, a wide-distributed cytoprotective amino acid, plays an important role as a basic factor for maintaining cellular integrity homeostasis. However, the potential effect of taurine in OTA-induced nephrotoxicity remains unknown. In the present study, we demonstrated that OTA treatment at 4.0-8.0 μM increased apoptosis in PK-15 cells as shown by increased the ratio of apoptosis and protein expression of Bax and cleaved-caspase-3, decreased protein expression of Bcl-2. Meantime, OTA treatment triggered autophagy, as indicated by markedly increased the protein expression of LC3-II and fluorescence intensity of GFP-LC3 dots. Taurine supplementation decreased OTA-induced cytotoxicity and attenuated apoptosis as shown by the decreased Annexin V/PI staining and the decreased expression of apoptosis-related proteins including Bax and caspase-3. Meanwhile, taurine attenuated OTA-induced autophagy by decreased the protein expression of LC3-II and fluorescence intensity of GFP-LC3 dots to maintain cellular homeostasis. In conclusion, taurine treatment could alleviate OTA-induced apoptosis and inhibit the triggered autophagy in PK-15 cells. Our study provides supportive data for the potential roles of taurine in reducing OTA-induced renal toxicity.

Ochratoxin A triggered intracerebral hemorrhage in embryonic zebrafish: Involvement of microRNA-731 and prolactin receptor

Ochratoxin A (OTA), a mycotoxin widely found in foodstuffs, reportedly damages multiple brain regions in developing rodents, but the corresponding mechanisms have not been elucidated. In this study, zebrafish embryos at 6 h post fertilization (hpf) were exposed to various concentrations of OTA and the phenomenon associated with intracerebral hemorrhage was observed at 72 hpf. Exposure of embryos to OTA significantly increased their hemorrhagic rate in a dose-dependent manner. Large numbers of extravagated erythrocytes were observed in the midbrain/hindbrain areas of Tg(fli-1a:EGFP; gata1:DsRed) embryos following exposure to OTA. OTA also disrupted the vascular patterning, especially the arch-shaped central arteries (CtAs), in treated embryos. Histological analysis revealed a cavity-like pattern in their hindbrain ventricles, implying the possibility of cerebral edema. OTA-induced intracerebral hemorrhage and CtA vessel defects were partially reversed by the presence of miR-731 antagomir or the overexpression of prolactin receptor a (prlra); prlra is a downstream target of miR-731. These results suggest that exposure to OTA has a negative effect on cerebral vasculature development by interfering with the miR-731/PRLR axis in zebrafish.

Maternal mycotoxin exposure and adverse pregnancy outcomes: a systematic review

Mycotoxin exposure from food occurs globally but is more common in hot humid environments, especially in low-income settings, and might affect pregnancy outcomes. This study aimed to synthesize the evidence from epidemiological studies on the relationship between maternal or fetal exposure to different mycotoxins and the occurrence of adverse pregnancy outcomes. Multiple databases were systematically searched up to December 2018 to identify studies that assessed the association between mycotoxin exposure in pregnant women or fetuses and at least one pregnancy outcome. Studies were appraised and results were synthesized using standard methods for conducting systematic reviews. This review identified and included 17 relevant studies. There is some evidence to suggest that exposure to various Aspergillus mycotoxins (e.g., aflatoxin) during pregnancy may impair intrauterine fetal growth and promote neonatal jaundice. Findings were inconclusive concerning the influence of aflatoxin exposure on perinatal death and preterm birth. Only two studies assessed effects of maternal exposure to Fusarium mycotoxins (e.g., fumonisin) on adverse pregnancy outcomes. These studies found that maternal fumonisin exposure may be associated with hypertensive emergencies in pregnancy and with neural tube defects. Studies using grain farming and weather conditions as a proxy measure for mycotoxin exposure found that such exposure was associated with an increased risk of preterm birth and late-term miscarriage. In conclusion, there is already some evidence to suggest that exposure to mycotoxins during pregnancy may have detrimental effects on pregnancy outcomes. However, given the limited number of studies, especially on effects of Fusarium mycotoxins, more studies are needed for a more comprehensive understanding of the effects of different mycotoxins on maternal and fetal health and to guide public health policies and interventions.

Melatonin ameliorates ochratoxin A-induced oxidative stress and apoptosis in porcine oocytes

Melatonin is a hormone which is generated from pineal gland, and it is responsible for the regulation of wake-sleep cycle. Melatonin is a well-known antioxidant and free radical scavenger to protect against multiple type of tissue damage. While ochratoxin A (OTA) is a mycotoxin found widely in contaminated food and foodstuffs, which causes nephrotoxicity, hepatotoxicity, immunotoxicity, and reproductive damage in humans and animals. In present study we report the toxicity of OTA on porcine oocyte quality and the protective effects of melatonin on OTA-exposed oocytes. Using transcriptome analysis our results show that OTA exposure alters the expression of multiple genes in oocytes, indicating its effect on oocyte maturation. The cellular changes following OTA treatment are examined, and the results show that OTA adversely affects oocyte polar body extrusion, which is confirmed by the delay of Cdc2-mediated cell cycle progression. OTA exposure also disrupts meiotic spindle formation, which is confirmed by altered phosphorylated MAPK expression. RNA-seq screening and further fluorescence staining results show that OTA induces aberrant mitochondria distribution and oxidative phosphorylation defects, which then causes oxidative stress, followed by early apoptosis and autophagy. Treatment with melatonin significantly ameliorates oxidative stress and apoptosis, which further protects cell cycle and spindle formation in OTA-exposed oocytes. Collectively, these results show the protective effects of melatonin against defects induced by OTA during porcine meiotic oocyte maturation.

Immunohistochemical Review of Leydig Cell Lesions in Ochratoxin A-Treated Fischer Rats and Controls

Ochratoxin A is best known as a potent renal carcinogen in male rats and mice after necessarily protracted ingestion, although valid extrapolation to any human disease has not been verified. The hypothesis that the toxin is a cause of human testicular cancer was proposed a decade ago and has proliferated since, partly through incomplete study of the scientific literature. Archived tumorous rat testes were available from Fischer F344 rats exposed to continuous dietary exposure for half of or the whole life in London in the 2000s. Renal cancer occurred in some of these cases and testicular tumours were observed frequently, as expected, in both treated and untreated animals. Application of clinical immunohistochemistry has for the first time consistently diagnosed the testicular hypertrophy in toxin-treated rats as Leydig cell tumours. Comparison is made with similar analysis of tumorous testes from control (untreated) rats from U.S. National Toxicology Program studies, both of ochratoxin A (1989) and the more recent one on Ginkgo biloba. All have been found to have identical pathology as being of sex cord-stromal origin. Such are rare in humans, most being of germinal cell origin. The absence of experimental evidence of any specific rat testicular cellular pathology attributable to long-term dietary ochratoxin A exposure discredits any experimental animal evidence of testicular tumorigenicity. Thus, no epidemiological connection between ochratoxin A and the incidence of human testicular cancer can be justified scientifically.

Zinc supplementation alleviates OTA-induced oxidative stress and apoptosis in MDCK cells by up-regulating metallothioneins

AIMS

The present study was to investigate the protective effects of Zn supplementation in OTA-induced apoptosis of Madin-Darby canine kidney (MDCK) epithelial cells and explore the potential mechanisms. Aiming to provides a new insight into the treatment strategy of OTA-induced nephrotoxicity by nutritional regulation.

MAIN METHODS

Initially, through MTT and LDH assay revealed that Zn supplementation significantly suppressed OTA-induced cytotoxicity in MDCK cells. Then, the production of reactive oxygen species (ROS) was detected by using a DCFH-DA assay. Annexin V-FITC/PI, Hoechst 33258 staining and Flow cytometry were used to detect the apoptosis. The expressions of apoptosis-related molecules were determined by RT-PCR, Western blotting. Interestingly, OTA treatment slightly increased the levels of Metallothionein-1 (MT-1) and Metallothionein-2 (MT-2) by using RT-PCR, Western blotting assay; while Zn supplementation further improved the increase of MT-1 and MT-2 induced by OTA. However, the inhibitive effects of Zn supplementation were significantly blocked after double knockdown of MT-1 and MT-2 by using Small Interfering RNA (siRNA) Transfection method.

KEY FINDINGS

Our study provides supportive data for the potential roles of Zn in reducing OTA-induced oxidative stress and apoptosis in MDCK cells.

SIGNIFICANCE

Zn is one of the key structural components of many proteins, which plays an important role in several physiological processes such as cell survival and apoptosis. This metal is expected to contribute to the conservative and adjuvant treatment of kidney disease and should therefore be investigated further.

Long-Term Effects of Ochratoxin A on the Glutathione Redox System and Its Regulation in Chicken

The purpose of this study was to evaluate the effect of three-weeks ochratoxin A (OTA) exposure on some lipid peroxidation parameters, reduced glutathione concentration and glutathione-peroxidase activity, as well as expression of oxidative stress response-related (KEAP1, NRF2) and glutathione system (GPX3, GPX4, GSS, GSR) genes in chickens. Three levels of exposure (106, 654 and 1126 μg/kg feed) were applied. The results showed that OTA initiated free radical formation, which was suggested by the increase in the malondialdehyde content in the liver and kidney, which was more marked in the liver, depending on the length of exposure and dose. Reduced glutathione concentration increased as an effect of the highest OTA dose in blood plasma and in liver, but not in red blood cell hemolysates and the kidney. Glutathione peroxidase activity did not change in the blood and showed increasing tendency in the liver, and significant increase in the kidney. Expression of KEAP1 gene showed up-regulation in the liver, and down-regulation in the kidney, but overexpression of NRF2 gene was found in the liver and kidney at the highest dose. However, down-regulation of Nrf2 dependent genes, GPX3, GPX4, GSS and GSR, suggested an improper antioxidant response at the protein level, thus oxidative stress occurred, even at the dose of the EU regulatory limit for poultry diets.

An iridium(III) complex/G-quadruplex ensemble for detection of ochratoxin A based on long-lifetime luminescent

A G-quadruplex-based platform has been developed for the time-resolved monitoring of ochratoxin A (OTA). The simple platform displays good sensitivity for OTA with a detection limit of 40 nM via steady-state emission spectroscopy. Notably, the platform showed a detection limit of 10.8 nM via time-resolved emission spectroscopy (TRES), which is about 4 times more sensitive than steady-state mode. Moreover, the probe showed excellent selectivity for OTA over other mycotoxins. Furthermore, OTA was successfully detected in actual herbal plant extracts samples. Our platform is the first to detect OTA using TRES to distinguish between the target signals versus the auto-fluorescence of real samples. This platform shows improved detection speed, accuracy and sensitivity with simple operation, low cost, and no requirement for complicated pre-processing.

A comparison of electronic nose and gas chromatography-mass spectrometry on discrimination and prediction of ochratoxin A content in Aspergillus carbonarius cultured grape-based medium

This study investigated discrimination and prediction of ochratoxin A (OTA) in three Aspergillus carbonarius strains cultured grape-based medium using E-nose technology and GC-MS analysis. Results showed that these strains cultured medium samples were divided into four groups regarding their log 10 OTA value using an equispaced normal distribution analysis. Partial least squares-discriminant analysis (PLS-DA) revealed that GC-MS PLS-DA model only separated the low OTA level medium samples from the rest OTA level samples, whereas all the OTA level samples were segregated from each other using E-nose PLS-DA model. Partial least squares regression (PLSR) analysis indicated that an excellent prediction performance was established on the accumulation of OTA in these medium samples using E-nose PLSR, whereas GC-MS PLSR model showed a screening performance on the OTA formation. These indicated that E-nose analysis could be a reliable method on discriminating and predicting OTA in A. carbonarius strains under grape-based medium.

Occurrence of Ochratoxin A in Coffee: Threads and Solutions—A Mini-Review

Ochratoxin A (OTA) is a widespread bioactive extrolite from secondary metabolism of fungi which presence in foods like coffee is of public health concern, particularly for heavy drinkers. Coffee is one of the most consumed and appreciated non-alcoholic beverage in the world. Its production from the plantation to the coffee cup involves several steps that would determine the final concentration of OTA in the beverage. This review gives an overview of OTA contamination in roasted coffee beans in different countries and mitigation strategies for OTA reduction.

Ochratoxin A Exposure Impairs Porcine Granulosa Cell Growth via the PI3K/AKT Signaling Pathway

The mycotoxin ochratoxin A (OTA), a naturally occurring food contaminant, has a toxic effect on the growth and development of follicles in pigs. However, little is known regarding the specific toxic effects of OTA exposure on oocytes and granulosa cells (GCs). In this study, we cultured porcine ovarian GCs and exposed them to OTA in vitro in order to explore the mechanism causing the negative effects. Initially, it was found that OTA exposure inhibited cell viability in a time and dose dependent manner. We also showed that OTA exposure increased oxidative stress, decreased proliferation ratio, and increased apoptosis ratio in GCs. We revealed an important role for the PI3K/AKT signal pathway in GC proliferation and apoptosis by RNA-seq analysis. The results not only showed that OTA treatment significantly affected the expression of genes within the PI3K/AKT pathway but also demonstrated a concrete relationship between the PI3K/AKT pathway and GC cell proliferation and apoptosis. In conclusion, the results demonstrated that OTA exposure impaired porcine GC growth via the PI3K/AKT signaling pathway.

Ochratoxin A suppresses proliferation of Sertoli and Leydig cells in mice

Ochratoxin A (OTA) is a mycotoxin originating from Penicillium and Aspergillus. In addition to toxic effects in various tissues and cells, including neurons, immune cells, hepatocytes, and nephrons, it also causes carcinogenesis and teratogenesis. Although the negative effects of OTA with respect to the pathogenesis of diseases and the malfunction of various organs have been studied widely, the biological signaling mechanisms in testicular cells are less well known. Therefore, we determined the hazardous effect of OTA in two types of testicular cells: TM3 (mouse Leydig cells) and TM4 (mouse Sertoli cells). Treatment with OTA led to a significant decrease in the proliferation of both cell lines, as revealed by an increased proportion of cells in the sub-G1 phase. In addition, the phosphorylation of signaling molecules belonging to the PI3K (Akt, P70S6K, and S6) and MAPK (ERK1/2 and JNK) pathways was regulated by OTA in a dose-dependent manner in TM3 and TM4 cells. Furthermore, the combination treatment of OTA and signaling inhibitors (LY294002, U0126, or SP600125) exerted synergistic antiproliferative effects in TM3 and TM4 cells. OTA also reduced the concentration of calcium ions in the cytosol and mitochondria, which disrupted the calcium homeostasis necessary for maintaining the normal physiological functions of testicular cells. In conclusion, the results of the present study demonstrate the mechanism underlying the antiproliferative effects of OTA in mouse testicular cells. Exposure to OTA may result in abnormal sperm maturation and the failure of spermatogenesis, which leads to male infertility.

Mycotoxins induce developmental toxicity and behavioural aberrations in zebrafish larvae

Mycotoxins are secondary metabolites produced by varieties of fungi that contaminate food and feed resources and are capable of inducing a wide range of toxicity. In the current study, we investigated developmental and behavioural toxicity in zebrafish larvae after exposure to six different mycotoxins; ochratoxin A (OTA), type A trichothecenes mycotoxin (T-2 toxin), type B trichothecenes mycotoxin (deoxynivalenol - DON), and zearalenone (ZEN) and its metabolites alpha-zearalenol (α-ZOL) and beta-zearalenol (β-ZOL). Developmental defects, hatching time, and survival were monitored until 96 h post fertilisation (hpf). The EC₅₀, LC₅₀, and IC₅₀ values were calculated. Subsequently, to assess behavioural toxicity, new sets of embryos were exposed to a series of non-lethal doses within the range of environmental and/or developmental concern. Results indicated that all the tested mycotoxins were toxic, they all induced developmental defects, and with the exception of OTA, all affected hatching time. Behavioural effects were only observed following exposure to OTA and ZEN and its metabolites, α ZOL and β ZOL. These results demonstrate that mycotoxins are teratogenic and can influence behaviour in a vertebrate model.

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.