Influence of mycotoxin zearalenone and its derivatives (alpha and beta zearalenol) on apoptosis and proliferation of cultured granulosa cells from equine ovaries

BACKGROUND: The mycotoxin zearalenone (ZEA) and its derivatives, alpha and beta-zearalenol (alpha and beta-ZOL), synthesized by genera Fusarium, often occur as contaminants in cereal grains and animal feeds. The importance of ZEA on reproductive disorders is well known in domestic animals species, particularly in swine and cattle. In the horse, limited data are available to date on the influence of dietary exposure to ZEA on reproductive health and on its in vitro effects on reproductive cells. The aim of this study was to evaluate the effects of ZEA and its derivatives, alpha and beta-ZOL, on granulosa cells (GCs) from the ovaries of cycling mares. METHODS: The cell proliferation was evaluated by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test after 3 days exposure at different concentrations of ZEA and its derivatives (from 1 × 10-7 to 0.1 microM). The apoptosis induction was evaluated after 1 day exposure, by DNA analysis using flow cytometry. RESULTS: An increase in cell proliferation with respect to the control was observed in the presence of ZEA at 1 × 10-3 and 1 × 10-4 microM and apoptosis was induced by all mycotoxins at different concentrations. CONCLUSION: The simultaneous presence of apoptosis and proliferation in GC cultures treated with zearalenones could indicate that these mycotoxins could be effective in inducing follicular atresia. These effects of zearalenones may result from both direct interaction with oestrogen-receptors as well as interaction with the enzymes 3alpha (beta)-hydroxysteroid dehydrogenase (HSD), involved in the synthesis and metabolism of endogenous steroid hormones. These cellular disturbances, described for the first time in equine GCs cultured in vitro, could be hypothesized as referred to reproductive failures of unknown ethiology in the mare

The Mycotoxin Deoxynivalenol Potentiates Intestinal Inflammation by Salmonella Typhimurium in Porcine Ileal Loops

Background and Aims: Both deoxynivalenol (DON) and nontyphoidal salmonellosis are emerging threats with possible hazardous effects on both human and animal health. The objective of this study was to examine whether DON at low but relevant concentrations interacts with the intestinal inflammation induced by Salmonella Typhimurium. Methodology: By using a porcine intestinal ileal loop model, we investigated whether intake of low concentrations of DON interacts with the early intestinal inflammatory response induced by Salmonella Typhimurium. Results: A significant higher expression of IL-12 and TNF alpha and a clear potentiation of the expression of IL-1 beta, IL-8, MCP-1 and IL-6 was seen in loops co-exposed to 1 mu g/mL of DON and Salmonella Typhimurium compared to loops exposed to Salmonella Typhimurium alone. This potentiation coincided with a significantly enhanced Salmonella invasion in and translocation over the intestinal epithelial IPEC-J2 cells, exposed to non-cytotoxic concentrations of DON for 24 h. Exposure of Salmonella Typhimurium to 0.250 mu g/mL of DON affected the bacterial gene expression level of a limited number of genes, however none of these expression changes seemed to give an explanation for the increased invasion and translocation of Salmonella Typhimurium and the potentiated inflammatory response in combination with DON. Conclusion: These data imply that the intake of low and relevant concentrations of DON renders the intestinal epithelium more susceptible to Salmonella Typhimurium with a subsequent potentiation of the inflammatory response in the gut

Changes in Th1 and Th2 cytokine concentrations in ileal Peyer’s patches in gilts exposed to zearalenone

GALT induces tolerance to foreign food antigens and plays an important role in the development of food allergies and the inflammatory bowel disease. The immune function of GALT is significantly influenced by an equilibrium between Th1 and Th2 subpopulations and the cytokines they produce. Th1 cytokines participate in the induction of a cell-mediated immune response, whereas Th2 cytokines induce powerful antibody-mediated responses. Changes in Th1/Th2 cell polarization of an immune response are associated with susceptibility to autoimmune and infectious diseases. This experiment investigated changes in cytokine levels produced by Th1 and Th2 cells in ileal Payer’s patches in gilts exposed to ZEN doses below the NOEL (approximately 8 μg kg⁻¹ BW) for 14, 28 and 42 days. A significant linear increase in IL-4 (40.32 ± 1.55 ng mg⁻¹ - 137.60 ± 29.96 ng mg⁻¹), and IL-10 (5.99 ± 0.15 ng mg⁻¹ - 16.39 ± 1.11 ng mg⁻¹) concentrations was observed. An increase in Th1 (IL-2 and IFN-γ) cytokine levels was also noted in the experimental group, but it was not statistically significant. An HPLC analysis of Peyer’s patches in group E animals revealed a linear increase in ZEN concentrations (3.65 ± 0.91 ng g⁻¹ - 4.72 ± 1.85 ng g⁻¹) and an absence of α-ZEL. IL-4 stimulates monocytes and macrophages, it induces the production of proinflammatory cytokines and it may directly and indirectly contribute to the development of inflammatory foci. Higher IL-4 levels could shift polarization toward Th2 cells, stimulate B cells to undergo class switching to produce IgE and contribute to the development of allergies

Zearalenone induces apoptosis and inhibits proliferation in porcine ileal Peyer’s patch lymphocytes

Zearalenone (ZEN) is one of the most active natural estrogenic compounds that induces apoptosis. This study has been prompted by the widespread occurrence of ZEN in food and feed and limited knowledge about the effects of exposure to low doses of ZEN on the immune system. The aim of the study was to verify the hypothesis that low doses of ZEN contribute to induction of apoptosis and inhibition of proliferation in lymphocytes of the germinal centers (GC) of ileal Peyer's patches (IPP) in pigs. The experiment was performed on 30 female Polish Large White pigs, aged 2 months, with body weight of 15-18 kg, divided into two groups: control (C, n=15) and experimental (Z, n=15). On days 14, 28 and 42 of exposure to ZEN (100 |ig kg-1 feed day-1), apoptosis in IPP GC was evaluated histologically in HE-stained specimens, immunohistochemically by active caspase-3 staining and in mononucleosome and oligonucleosome detection-based ELISA. Proliferation was evaluated his-tologically by mitosis detection in HE-stained specimens, immunohistochemically by PCNA staining and in the MTT tetrazolium salt colorimetric assay detecting mitogenic responses of B cells to LPS. Exposure to low doses of ZEN for several weeks intensified apoptosis and weakened proliferation in IPP lymphocytes. ZEN influences gut-associated lymphoid tissue (GALT) by decreasing the expression of CD21+ on B cells and by increasing the percentage of B1 cell populations

Zearalenone-induced changes in the lymphoid tissue and mucosal nerve fibers in the porcine ileum

This is the first study to examine zearalenone-(ZEN) induced changes in the immune system of the ileum and substance P-(SP-) and vasoactive intestinal peptide-(VIP-) immunoreactive nerve fibers in the mucosa, which participate in the regulation of intestinal functions under physiological conditions and during pathological processes. The aim of this study was also to identify potential relationships between selected immune and neural elements in ileal Peyer's patches in pigs that were and were not exposed to ZEN. The experiment was performed on 10 prepubertal gilts divided into two groups: the experimental group (n=5) where ZEN was administered at 0.1 mg kg-1 feed day-1 for 42 days, and the control group (n=5) which was administered a placebo. The tissue levels of cytokines were determined by enzyme-linked immunosorbent assay which revealed elevated concentrations of IL-12/23 40p and IL-1 ß in animals exposed to ZEN. Flow cytometry revealed a lower percentage of CD21+ lymphocytes in pigs exposed to ZEN in comparison with control animals. The tissue levels of neuropeptides were evaluated in the dot blot procedure which demonstrated higher concentrations of VIP and SP in experimental pigs. In experimental animals, numerous VIP-like immunoreactive processes were observed, and SP-immunoreactive nerve fibers formed a very dense network. Our results demonstrate for the first time that ZEN can modify the chemical coding of nerve structures in the gastrointestinal system. Those modifications can be attributed to ZEN's impact on estrogen receptors or its pro-inflammatory properties, and they reflect changes that take place in the nervous system at the transcriptional, translational and metabolic level

Zearalenone and deoxynivalenol mycotoxicosis in dairy cattle herds

Mycotoxin contaminations pose a growing problem in animal production from the economic and toxicological point of view. Clinical symptoms of mycotoxicosis are relatively unspecific, making the disease difficult to diagnose. This study presents a clinical case of dairy cattle infected with natural mycotoxins produced by fungi of the genus Fusarium (zearalenone [ZEA] and deoxynivalenol [DON]) in eastern Poland. In dead and infected cows, the presence of ZEA and DON was determined in the blood serum, significant changes were observed in blood morphological and biochemical profiles, extravasations and bowel inflammations were also observed. The results reported testify to an acute autoimmune process in the intestines as well as immunosuppression

Estimation of Blood Alcohol Concentrations in Young Male Drinkers

This research examined individual differences in the ability to self‐monitor the effects of alcohol. Thirty‐nine male subjects consumed 0.75 ml/kg alcohol and estimated their blood alcohol concentrations (BACs) at peak BAC and on the ascending and descending limbs of the blood alcohol curve. Family history of alcohol dependence did not affect the accuracy of estimation of BACs. Subjects who reported lower levels of subjective intoxication underestimated their BACs more than did subjects who reported higher levels of subjective intoxication. Subjects with less behavioral impairment underestimated their BACs more than subjects with greater behavioral impairment on the ascending limb of the blood alcohol curve. Accuracy was better on the ascending limb compared with peak BAC and the descending limb, and accuracy became worse over time on the descending limb. It appears that cues to the effects of alcohol rapidly become unavailable on the descending limb, which may contribute to decisions concerning further alcohol consumption and driving after drinking

Multi-mycotoxicosis

Contamination of food and feeds with mycotoxins is a major problem of human and animal's health concern, and it is also extremely detrimental to economy. Mycotoxin-producing moulds may produce the most known mycotoxins, such as aflatoxins, ochratoxin, trichothecenes, zearalenone and fumonisin. Although toxicological, environmental and epidemiological studies have addressed the problem of these toxins one by one, more than one mycotoxin is found usually in the same contaminated commodities. That raises the incommensurable problem of multi-mycotoxicosis in which the respective metabolites are also involved. These mycotoxins bear potential toxicity leading to acute and chronic effects in humans and animals, depending on species. The mechanisms that lead to toxic effects, such as immune toxicity and carcinogenicity, are complex. The risk assessment for humans potentially exposed to multi-mycotoxins suffers very much from the lack of adequate food consumption data. Furthermore, for a given mycotoxin additive, synergism and antagonism with other mycotoxins found in the same food commodities are usually not taken into account