Exposure to a Combination of Fusarium Mycotoxins Leads to Lipid Peroxidation and Influences Antioxidant Defenses, Fatty Acid Composition of Phospholipids, and Renal Histology in Laying Hens.

The effects of combined short-term (3 days) exposure to Fusarium mycotoxins at both the EU recommended limit (T-2/HT-2 toxin: 0.25 mg/kg; DON/3-AcDON/15-AcDON: 5 mg/kg; FB1: 20 mg/kg) and twice the dose (T-2/HT-2 toxin: 0.5 mg/kg, DON/3-AcDON/15-AcDON: 10 mg/kg, and FB1: 40 mg/kg feed) on the kidneys of laying hens were examined. Our study aimed to investigate how these mycotoxins interacted with membrane lipid fatty acid (FA) composition and lipid peroxidation processes. It was observed that the levels of conjugated dienes and trienes were higher than the control in the low-mix group on day 3, and malondialdehyde concentration was higher on days 2 and 3. The proportion of phospholipid (PL) FAs showed that saturated and monounsaturated FAs increased. Still, both n3 and n6 polyunsaturated FAs decreased significantly on day 2 of exposure in the high-mix group. Among the n3 FAs, the level of docosahexaenoic (C22:6 n3) and among n6 FAs, arachidonic (C20:4 n6) acids decreased mainly on day 2 in the high-mix group. The results suggest that the combined exposure to Fusarium mycotoxins induced lipid peroxidation in the kidneys of laying hens, which resulted in marked changes in the PL FA profile. Histological examination revealed time- and dose-dependent increases as consequences of mycotoxin exposure.

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.

The Effects of T-2 Toxin, Deoxynivalenol, and Fumonisin B1 on Oxidative Stress-Related Genes in the Kidneys of Laying Hens.

In the context of nephrotoxic risks associated with environmental contaminants, this study focused on the impact of mycotoxin exposure on the renal health of laying hens, with particular attention to oxidative stress pathways. Sixty laying hens were assigned to three groups-a control group (CON), a low-dose mycotoxin group (LOW), and a high-dose mycotoxin group (HIGH)-and monitored for 72 h. Mycotoxin contamination involved T-2/HT-2 toxin, DON/3-AcDON/15-AcDON, and FB1 at their EU-recommended levels (low mix) and at double doses (high mix). Clinical assessments revealed no signs of toxicity or notable weight changes. Analysis of the glutathione redox system parameters demonstrated that the reduced glutathione content was lower than that in the controls at 48 h and higher at 72 h. Glutathione peroxidase activity increased in response to mycotoxin exposure. In addition, the gene expression patterns of key redox-sensitive pathways, including Keap1-Nrf2-ARE and the AhR pathway, were examined. Notably, gene expression profiles revealed dynamic responses to mycotoxin exposure over time, underscoring the intricate interplay of redox-related mechanisms in the kidney. This study sheds light on the early effects of mycotoxin mixtures on laying hens' kidneys and their potential for oxidative stress.

Curcumin mitigates ochratoxin A-induced oxidative stress and alters gene expression in broiler chicken liver and kidney.

The study aimed to evaluate the effect of curcumin (CURC) supplementation on broiler chickens exposed to ochratoxin A (OTA), by examining biochemical parameters and the expression of glutathione redox system genes and their regulation. OTA reduced glutathione content in the liver while increasing glutathione peroxidase activity. CURC showed no significant effects. Kidney parameters remained mostly unaffected. Gene expression analysis revealed OTA-induced upregulation of KEAP1, NRF2, AHR, GPx4 and GSR genes in the liver. CURC supplementation led to the upregulation of GPx4 and AHR genes with OTA+CURC treatment, resulting in the downregulation of GPx4, KEAP1, NRF2 and AHR genes compared to OTA treatment alone. In the kidney, GPx4 was downregulated, and NRF2 and AHR were upregulated as an effect of OTA, while CURC upregulated the NRF2 gene only. OTA+CURC treatment led to the downregulation of GPx4, GSS and AHR genes compared to the control and downregulation of NRF2 and AHR genes compared to OTA. The results suggested that CURC is partly effective against OTA-induced oxidative stress and that the effect of OTA and CURC on the antioxidant response is regulated through the KEAP1-NRF2-ARE and AHR pathways.

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.

Modification of the effects of aflatoxin B1 on the glutathione system and its regulatory genes by zeolite.

The purpose of the present study was to use oxidative stress markers for investigating the effect of zeolite (315 mg/kg of complete feed) in the case of aflatoxin B1 contamination (92 µg/kg complete feed). In a 21-day feeding trial with broiler chickens, oxidative stress parameters such as conjugated dienes, conjugated trienes, malondialdehyde, reduced glutathione content and glutathione peroxidase activity were not changed significantly by supplementation with this mycotoxin absorbent. The relative gene expression of transcription factors KEAP1 and NRF2 was not modified by the absorbent either. Still, the expression of GSS, GSR and GPX4 genes increased significantly due to the aluminosilicate supplementation. The results suggest that zeolite reduced lipid peroxidation in the blood plasma but not in the red blood cell haemolysate or the kidney. The relative expression of the genes encoding the glutathione redox system also changed as a result of zeolite supplementation, but these changes were not found at the protein level.

Individual and Combined Effects of Aflatoxin B1 and Sterigmatocystin on Lipid Peroxidation and Glutathione Redox System of Common Carp Liver.

The purpose of the study was to evaluate the short-term effects of aflatoxin B1 (AFB1 100 µg/kg feed) and sterigmatocystin (STC 1000 µg/kg feed) exposure individually and in combination (100 µg AFB1 + 1000 µg STC/kg feed) on the parameters of lipid peroxidation and glutathione redox system both in biochemical and gene expression levels in one-year-old common carp. Lipid peroxidation parameters were slightly affected, as significant differences were observed only in conjugated diene and triene concentrations. Reduced glutathione content decreased more markedly by STC than AFB1 or AFB1+STC, but glutathione peroxidase activity did not change. Expression of gpx4a, gpx4b, gss, and gsr genes was down-regulated due to STC compared to AFB1 or AFB1+STC, while an induction was found as effect of AFB1+STC in the case of gpx4a, but down-regulation for gpx4b as compared to AFB1. Expression of the glutathione biosynthesis regulatory gene, gss, was higher, but glutathione recycling enzyme encoding gene, gsr, was lower as an effect of AFB1+STC compared to AFB1. These results are supported by the changes in the expression of transcription factors encoding genes, nrf2, and keap1. The results revealed that individual effects of AFB1 and STC on different parameters are synergistic or antagonistic in multi-toxin treatment.

Short-term effects of deoxynivalenol, T-2 toxin, fumonisin B1 or ochratoxin on lipid peroxidation and glutathione redox system and its regulatory genes in common carp (Cyprinus carpio L.) liver.

The effects of a single oral dose of 1.82 mg kg-1 bw of T-2 and HT-2 toxin (T-2), 1.75 mg kg-1 bw deoxynivalenol (DON) and 15-acetyl DON, 1.96 mg kg-1 bw fumonisin B1 (FB1) or 1.85 mg kg-1 bw ochratoxin A (OTA) were investigated in common carp juveniles on lipid peroxidation, the parameters of the glutathione redox system including the expression of their encoding genes in a short-term (24 h) experiment. Markers of the initiation phase of lipid peroxidation, conjugated dienes, and trienes, were slightly affected by DON and OTA treatment at 16-h sampling. The termination marker, malondialdehyde, concentration increased only as an effect of FB1. Glutathione content and glutathione peroxidase activity showed significantly higher levels in the T-2 and FB1 groups at 8 h, and in the DON and FB1 groups at 16 h. The expression of glutathione peroxidase genes (gpx4a, gpx4b) showed a dual response. Downregulation of gpxa was observed at 8 h, as the effect of DON, FB1, and OTA, but an upregulation in the T-2 group. At 16 h gpx4a upregulated as an effect of DON, T-2, and FB1, and at 24 h in the DON and T-2 groups. Expression of gpx4b downregulated at 8 h, except in the T-2 group, and upregulation observed as an effect of T-2 at 24 h. The lack of an increase in the expression of nrf2, except as the effect of DON at 8 h, and a decrease in the keap1 expression suggests that the antioxidant defence system was activated at gene and protein levels through Keap1-Nrf2 independent pathways.

Multi-trichothecene mycotoxin exposure activates glutathione-redox system in broiler chicken.

Co-occurrence of mycotoxin contamination of feeds is a frequent problem, therefore the purpose of this study was to evaluate the combined effect of T-2 toxin and deoxynivalenol (DON) on lipid peroxidation, parameters and regulation of the glutathione redox system in broiler chickens in a sub-chronic (7 day) study. The applied doses were: low mix: 0.23 mg T-2 toxin and 4.96 mg DON/kg feed; medium mix: 1.21 mg T-2 toxin and 12.38 mg DON/kg feed; and high mix: 2.42 T-2 toxin and 24.86 mg DON/kg feed. Liver samples were taken on days 0, 1, 2, 3, and 7 of the feeding trial. Lipid peroxidation decreased significantly as compared to the control on days 3 and 7 as effect of low and high doses, which can be related to the activation of the antioxidant system, which is supported by the elevated glutathione peroxidase activity and reduced glutathione concentration as compared to the control on day 3 in the medium and high dose groups. Gene expression of glutathione peroxidase 4 (GPX4) elevated on day 1 in a dose dependent manner, and showed continuous elevation in the highest dose group thereafter. The results suggested that common exposure of T-2 toxin and DON induced oxidative stress in the liver of broiler chickens, which activated the enzymatic antioxidant system, and consequently decreased lipid peroxidation.