Effects of Fusarium Mycotoxin Exposure on Lipid Peroxidation and Glutathione Redox System in the Liver of Laying Hens

Resveratrol Alleviated T-2 Toxin-Induced Liver Injury via Preservation of Nrf2 Pathway and GSH Synthesis

T-2 toxin is a trichothecene mycotoxin and is considered as an extremely inevitable pollutant with potent hepatotoxicity. However, the approach to alleviation of T-2 toxin-triggered hepatotoxicity has been recognized as a serious challenge. Resveratrol (Res) is a polyphenol natural product isolated from various plant species, but its protective effect against T-2 toxin hepatotoxicity and detailed mechanism remains obscure. In the present study, the effect of Res against the hepatotoxicity was evaluated, and the underlying mechanisms were further revealed in mice. Functionally, Res inhibited liver injury, oxidative damage, and mitochondrial dysfunction induced by T-2 toxin. Mechanistically, Res modulated Nrf2-mediated antioxidant pathway and glutathione synthesis inhibition. Collectively, our findings first showed beyond doubt that Res ameliorated T-2 toxin-triggered liver injury by regulating Nrf2 pathways in mice.

Fumonisin B1 induces endoplasmic reticulum damage and inflammation by activating the NXR response and disrupting the normal CYP450 system, leading to liver damage in juvenile quail

Fumonisin B1 (FB1) is a mycotoxin affecting animal health through the food chain and has been closely associated with several diseases such as pulmonary edema in pigs and diarrhea in poultry. FB1 is mainly metabolized in the liver. Although a few studies have shown that FB1 causes liver damage, the molecular mechanism of liver damage is unclear. This study aimed to evaluate the role of liver damage, nuclear xenobiotic receptor (NXR) response and cytochrome P450 (CYP450)-mediated defense response during FB1 exposure. A total of 120 young quails were equally divided into two groups (control and FB1 groups). The quails in the control group were fed on a normal diet, while those in the FB1 group were fed on a quail diet containing 30 mg/kg for 42 days. Histopathological and ultrastructural changes in the liver, biochemical parameters, inflammatory factors, endoplasmic reticulum (ER) factors, NXR response and CYP450 cluster system and other related genes were examined at 14 days, 28 days and 42 days. The results showed that FB1 exposure impaired the metabolic function and caused liver injury. FB1 caused ER stress and decreased adenosine triphosphatease activity, induced the expression of inflammation-related genes such as interleukin 6 and nuclear factor kappa-B, and promoted inflammation. In addition, FB1 disrupted the expression of multiple CYP450 isoforms by activating nuclear xenobiotic receptors (NXRs). The present study confirms that FB1 exposure disturbs the homeostasis of cytochrome P450 systems (CYP450s) in quail liver by activating NXR responses and thereby causing liver damage. This study's findings provide insight into the molecular mechanisms of FB1-induced hepatotoxicity.

An Algoclay-Based Decontaminant Decreases Exposure to Aflatoxin B1, Ochratoxin A, and Deoxynivalenol in a Toxicokinetic Model, as well as Supports Intestinal Morphology, and Decreases Liver Oxidative Stress in Broiler Chickens Fed a Diet Naturally Contaminated with Deoxynivalenol

The aims of this study were (i) to determine the effect of an algoclay-based decontaminant on the oral availability of three mycotoxins (deoxynivalenol; DON, ochratoxin A; OTA, and aflatoxin B1; AFB1) using an oral bolus model and (ii) to determine the effect of this decontaminant on the performance, intestinal morphology, liver oxidative stress, and metabolism, in broiler chickens fed a diet naturally contaminated with DON. In experiment 1, sixteen 27-day-old male chickens (approximately 1.6 kg body weight; BW) were fasted for 12 h and then given a bolus containing either the mycotoxins (0.5 mg DON/kg BW, 0.25 mg OTA/kg BW, and 2.0 mg AFB1/kg BW) alone (n = 8) or combined with the decontaminant (2.5 g decontaminant/kg feed; circa 240 mg/kg BW) (n = 8). Blood samples were taken between 0 h (before bolus administration) and 24 h post-administration for DON-3-sulphate, OTA, and AFB1 quantification in plasma. The algoclay decontaminant decreased the relative oral bioavailability of DON (39.9%), OTA (44.3%), and AFB1 (64.1%). In experiment 2, one-day-old male Ross broilers (n = 600) were divided into three treatments with ten replicates. Each replicate was a pen with 20 birds. The broiler chickens were fed a control diet with negligible levels of DON (0.19-0.25 mg/kg) or diets naturally contaminated with moderate levels of DON (2.60-2.91 mg/kg), either supplemented or not with an algoclay-based decontaminant (2 g/kg diet). Jejunum villus damage was observed on day 28, followed by villus shortening on d37 in broiler chickens fed the DON-contaminated diet. This negative effect was not observed when the DON-contaminated diet was supplemented with the algoclay-based decontaminant. On d37, the mRNA expression of glutathione synthetase was significantly increased in the liver of broiler chickens fed the DON-contaminated diet. However, its expression was similar to the control when the birds were fed the DON-contaminated diet supplemented with the algoclay-based decontaminant. In conclusion, the algoclay-based decontaminant reduced the systemic exposure of broiler chickens to DON, OTA, and AFB1 in a single oral bolus model. This can be attributed to the binding of the mycotoxins in the gastrointestinal tract. Moreover, dietary contamination with DON at levels between 2.69 and 2.91 mg/kg did not impair production performance but had a negative impact on broiler chicken intestinal morphology and the liver redox system. When the algoclay-based decontaminant was added to the diet, the harm caused by DON was no longer observed. This correlates with the results obtained in the toxicokinetic assay and can be attributed to a decreased absorption of DON.

The Effect of Combined Exposure of Fusarium Mycotoxins on Lipid Peroxidation, Antioxidant Defense, Fatty Acid Profile, and Histopathology in Laying Hens' Liver

Fumonisin B1, T-2 toxin, and deoxynivalenol are frequently detected in feed materials. The mycotoxins induce free radical formation and, thereby, lipid peroxidation. The effects of mycotoxin exposure at the EU recommended limit (T-2/HT-2 toxin: 0.25 mg/kg; DON = 3AcDON/15-AScDON: 5 mg/kg; fumonisin B1: 20 mg/kg) and double dose (T-2/HT-2 toxin: 0.5 mg/kg, DON/3-AcDON/15-AcDON: 10 mg, and FB1: 40 mg/kg feed) were investigated during short-term (3 days) per os exposure in the liver of laying hens. On day 1 higher while on day 3 lower MDA concentrations were found in the low-dose group compared to the control. Fatty acid composition also changed: the proportion of monounsaturated fatty acids increased (p < 0.05) and the proportion of polyunsaturated fatty acids decreased by day 3. These alterations resulted in a decrease in the index of unsaturation and average fatty acid chain length. Histopathological alterations suggested that the incidence and severity of liver lesions were higher in the mycotoxin-treated laying hens, and the symptoms correlated with the fatty acid profile of total phospholipids. Overall, the findings revealed that mycotoxin exposure, even at the EU-recommended limits, induced lipid peroxidation in the liver, which led to changes in fatty acid composition, matched with tissue damage.

T-2 toxin induces cardiotoxicity by activating ferroptosis and inhibiting heme oxygenase-1

T-2 toxin, a natural secondary sesquiterpenoid metabolite produced by numerous strains of Fusarium fungi, is prevalent in both contaminated food and the environment. T-2 toxin is known to be highly toxic to the cardiovascular system, but the precise mechanisms that lead to T-2 toxin-induced cardiotoxicity are not yet fully understood. Recent findings indicate that ferroptosis is a pivotal factor in cardiovascular damage and exhibits a strong correlation with the detrimental impacts of T-2 toxin. The present study was designed to examine the involvement of ferroptosis in T-2 toxin-induced cardiac injury. Male mice and human cardiomyocytes were subjected to T-2 toxin for 24 h to induce acute cardiotoxicity for in vivo and in vitro studies, respectively. Our results demonstrated that T-2 toxin increased reactive oxygen species production, malondialdehyde, and decreased glutathione/oxidized glutathione and adenosine triphosphate levels. Furthermore, T-2 toxin was observed to activate ferroptosis, as evidenced by an increase in iron (Fe2+) concentration and upregulation of prostaglandin endoperoxide synthase 2, downregulation of glutathione peroxidase 4 and ferritin heavy chain 1, as well as ferroptotic morphological alterations. Inhibition of ferroptosis by Liproxstatin-1 reversed T-2 toxin-induced cardiac injury. Additionally, the downregulation of heme oxgenase-1 (HO-1) expression by T-2 toxin exacerbates ferroptosis and oxidative damage, which can be further aggravated by HO-1 inhibition with Sn-protoporphyrin. These findings provide novel insights into the mechanism of T-2 toxin-induced cardiotoxicity and suggest that targeting ferroptosis and HO-1 may represent a promising cardioprotective strategy against T-2 toxin.

Co-occurrence of Mycotoxin-Induced Hepatotoxicity in Mice Inhibited by Lycopene: Mitochondrial Impairment and Early Hepatic Fibrosis

SCOPE

Mycotoxins co-contamination of agricultural products poses a serious threat to human and animal health, especially hepatic dysfunction. Zearalenone (ZEN), deoxynivalenol (DON), and aflatoxin B1 (AFB1) are three commonly co-occurring mycotoxins. This study is to determine whether lycopene (LYC) can alleviate hepatic toxicity induced by the co-occurrence of ZEN, DON, and AFB1 in mice.

METHODS AND RESULTS

Eighty 6-week-old male ICR mice are divided into four groups: CON group (solvent control), LYC group (10 mg kg-1 LYC), Co-M group (10 mg kg-1 ZEN + 1 mg kg-1 DON + 0.5 mg kg-1 AFB1), and LYC+Co-M group (10 mg kg-1 LYC + 10 mg kg-1 ZEN + 1 mg kg-1 DON + 0.5 mg kg-1 AFB1). The results show that LYC can suppress the co-occurrence of mycotoxin-induced mitochondrial swelling and vacuolization accompanied by dysregulation of indices of mitochondrial dynamics (Mitofusin 1 (Mfn1), Mfn2, Optic atrophy 1 (Opa1), Dynamin-related protein 1 (Drp1), Fission 1 (Fis1) at the mRNA level; DRP1 and FIS1 at the protein level). LYC effectively inhibits co-occurrence of mycotoxin-induced activation of Cytochrome P450 2E1, and early fibrosis, as determined by staining with Masson's trichrome and α-SMA protein.

CONCLUSION

LYC successfully attenuates early hepatic fibrosis mainly through antioxidant activities and prevented mitochondrial injury.

Genetic assessment of the effect of red yeast (Sporidiobolus pararoseus) as a feed additive on mycotoxin toxicity in laying hens

Toxic fungal species produce hazardous substances known as mycotoxins. Consumption of mycotoxin contaminated feed and food causes a variety of dangerous diseases and can even lead to death of animals and humans, raising global concerns for adverse health effects. To date, several strategies have been developed to counteract with mycotoxin contamination. Red yeast as a novel biological dietary agent is a promising strategy to eliminate mycotoxicity in living organisms. Poultry are most susceptible animals to mycotoxin contamination, as they are fed a mixture of grains and are at higher risk of co-exposure to multiple toxic fungal substances. Therefore, this study investigated the genetic mechanism underlying long-term feeding with red yeast supplementation in interaction with multiple mycotoxins using transcriptome profiling (RNA_Seq) in the liver of laying hens. The results showed a high number of significantly differentially expressed genes in liver of chicken fed with a diet contaminated with mycotoxins, whereas the number of Significantly expressed genes was considerably reduced when the diet was supplemented with red yeast. The expression of genes involved in the phase I (CYP1A1, CYP1A2) and phase II (GSTA2, GSTA3, MGST1) detoxification process was downregulated in animals fed with mycotoxins contaminated diet, indicating suppression of the detoxification mechanisms. However, genes involved in antioxidant defense (GSTO1), apoptosis process (DUSP8), and tumor suppressor (KIAA1324, FBXO47, NME6) were upregulated in mycotoxins-exposed animals, suggesting activation of the antioxidant defense in response to mycotoxicity. Similarly, none of the detoxification genes were upregulated in hens fed with red yeast supplemented diet. However, neither genes involved in antioxidant defense nor tumor suppressor genes were expressed in the animals exposed to the red yeast supplemented feed, suggesting decreases the adsorption of biologically active mycotoxins in the liver of laying hens. We conclude that red yeast can act as a mycotoxin binder to decrease the adsorption of mycotoxins in the liver of laying hens and can be used as an effective strategy in the poultry feed industry to eliminate the adverse effects of mycotoxins for animals and increase food safety for human consumers.

T-2 toxin metabolism and its hepatotoxicity: New insights on the molecular mechanism and detoxification

T-2 toxin, a type A trichothecene, is a secondary metabolite produced by Fusarium poae, Fusarium sporotrichioides, and Fusarium tricinctum. As the most toxic trichothecenes, T-2 toxin causes severe damage to multiple organs, especially to liver. However, the contamination of T-2 toxin covers a wide range of plants, including nuts, grains, fruits and herbs globally. And due to chemical stability of T-2 toxin, it is difficult to be completely removed from the food and feeds, which poses a great threat to human and animal health. Liver is the major detoxifying organ which also makes it the main target of T-2 toxin. After being absorbed by intestine, the first pass effect will reduce the level of T-2 toxin in blood indicating that liver is the main metabolic site of T-2 toxin in vivo. In this review, updated researches on the hepatotoxicity of T-2 toxin were summarized. The metabolic characteristic of T-2 toxin in vivo was introduced. The main hepatotoxic mechanisms of T-2 toxin are oxidative stress, mitochondrial damage, deoxyribonucleic acid (DNA) methylation, autophagy and apoptosis. Recent research of the main hepatotoxic mechanisms of T-2 toxin and the interactions between these mechanisms were summarized. The remission of the hepatotoxicity induced by T-2 toxin was also studied in this review followed by new findings on the detoxification of hepatotoxicity induced by T-2 toxin. The review aimed to offer a comprehensive view and proposes new perspectives in the field of hepatotoxicity induced by T-2 toxin.

The Co-Occurrence of T-2 Toxin, Deoxynivalenol, and Fumonisin B1 Activated the Glutathione Redox System in the EU-Limiting Doses in Laying Hens

Different mycotoxins in feed lead to combined exposure, increasing adverse effects on animal health. Trichothecene mycotoxins have been associated with inducing oxidative stress, which is neutralized by the glutathione system within the antioxidant defense, depending on the dose and duration of exposure. T-2 toxin, deoxynivalenol (DON), and fumonisin B1 (FB1) are commonly found in feed commodities simultaneously. In the present study, the intracellular biochemical and gene expression changes were investigated in the case of multi-mycotoxin exposure, focusing on certain elements of the glutathione redox system. In a short-term feeding trial, an in vivo study was performed with low (EU-proposed) doses: T-2/HT-2 toxin: 0.25 mg; DON/2-AcDON/15-AcDON.: 5 mg; FB1: 20 mg/kg feed, and high doses (twice the low dose) in laying hens. The multi-mycotoxin exposure affected the glutathione system; GSH concentration and GPx activity was higher in the liver in the low-dose group on day 1 compared to the control. Furthermore, the gene expression of antioxidant enzymes increased significantly on day 1 in both exposure levels compared to the control. The results suggest that when EU-limiting doses are applied, individual mycotoxins may have a synergistic effect in the induction of oxidative stress.

Assessment of information as regards the toxicity of deoxynivalenol for horses and poultry

In 2017, the EFSA Panel on Contaminants in the Food Chain (CONTAM) adopted a Scientific Opinion on the risks for animal health related to the presence of deoxynivalenol (DON) and its acetylated and modified forms in food and feed. No observed adverse effect levels (NOAELs) and lowest observed adverse effect levels (LOAELs) were derived for different animal species. For horses, an NOAEL of 36 mg DON/kg feed was established, the highest concentration tested and not showing adverse effects. For poultry, an NOAEL of 5 mg DON/kg feed for broiler chickens and laying hens, and an NOAEL of 7 mg DON/kg feed for ducks and turkeys was derived. The European Commission requested EFSA to review the information regarding the toxicity of DON for horses and poultry and to revise, if necessary, the established reference points (RPs). Adverse effect levels of 1.9 and 1.7 mg DON/kg feed for, respectively, broiler chickens and turkeys were derived from reassessment of existing studies and newly available literature, showing that DON causes effects on the intestines, in particular the jejunum, with a decreased villus height but also histological damage. An RP for adverse animal health effects of 0.6 mg/kg feed for broiler chickens and turkeys, respectively, was established. For horses, an adverse effect level of 5.6 mg DON/kg feed was established from studies showing reduced feed intake, with an RP for adverse animal health effects of 3.5 mg/kg feed. For ducks and laying hens, RPs remain unchanged. Based on mean and P95 (UB) exposure estimates performed in the previous Opinion, the risk of adverse health effects of feeds containing DON was considered a potential concern for broiler chickens and turkeys. For horses, the risk for adverse health effects from feed containing DON is low.

Toxicity and detoxification of T-2 toxin in poultry

This review summarizes the updated knowledge on the toxicity of T-2 on poultry, followed by potential strategies for detoxification of T-2 in poultry diet. The toxic effects of T-2 on poultry include cytotoxicity, genotoxicity, metabolism modulation, immunotoxicity, hepatotoxicity, gastrointestinal toxicity, skeletal toxicity, nephrotoxicity, reproductive toxicity, neurotoxicity, etc. Cytotoxicity is the primary toxicity of T-2, characterized by inhibiting protein and nucleic acid synthesis, altering the cell cycle, inducing oxidative stress, apoptosis and necrosis, which lead to damages of immune organs, liver, digestive tract, bone, kidney, etc., resulting in pathological changes and impaired physiological functions of these organs. Glutathione redox system, superoxide dismutase, catalase and autophagy are protective mechanisms against oxidative stress and apoptosis, and can compensate the pathological changes and physiological functions impaired by T-2 to some degree. T-2 detoxifying agents for poultry feeds include adsorbing agents (e.g., aluminosilicate-based clays and microbial cell wall), biotransforming agents (e.g., Eubacterium sp. BBSH 797 strain), and indirect detoxifying agents (e.g., plant-derived antioxidants). These T-2 detoxifying agents could alleviate different pathological changes to different degrees, and multi-component T-2 detoxifying agents can likely provide more comprehensive protection against the toxicity of T-2.

Antioxidant Defences and Redox Homeostasis in Animals

For many years reactive oxygen species (ROS) production in biological systems has been considered to be detrimental [...]