Effects of Chronic Exposure to Low Levels of Dietary Aflatoxin B1 on Growth Performance, Apparent Total Tract Digestibility and Intestinal Health in Pigs

Chromatin accessibility and transcriptional landscape in PK-15 cells during early exposure to Aflatoxin B1

Aflatoxin B1 (AFB1) not only causes significant losses in livestock production but also poses a serious threat to human health. It is the most carcinogenic among known chemicals. Pigs are more susceptible to AFB1 and experience a higher incidence. However, the molecular mechanism of the toxic effect of AFB1 remains unclear. In this study, we used assay for transposase-accessible chromatin using sequencing (ATAC-seq) and RNA-seq to uncover chromatin accessibility and gene expression dynamics in PK-15 cells during early exposure to AFB1. We observed that the toxic effects of AFB1 involve signaling pathways such as p53, PI3K-AKT, Hippo, MAPK, TLRs, apoptosis, autophagy, and cancer pathways. Basic leucine zipper (bZIP) transcription factors (TFs), including AP-1, Fos, JunB, and Fra2, play a crucial role in regulating the biological processes involved in AFB1 challenge. Several new TFs, such as BORIS, HNF1b, Atf1, and KNRNPH2, represent potential targets for the toxic mechanism of AFB1. In addition, it is crucial to focus on the concentration of intracellular zinc ions. These findings will contribute to a better understanding of the mechanisms underlying AFB1-induced nephrotoxicity and offer new molecular targets.

Limosilactobacillus reuteri peptidoglycan alleviates aflatoxin B1-induced toxicity through adsorbing toxins and improving growth, antioxidant status, immunity and liver pathological changes in chicks

1. The objective of this study was to investigate the protective effects of a peptidoglycan produced by Limosilactobacillus reuteri against aflatoxin B1 (AFB1) induced toxicity in vitro and in vivo in broiler chicks.2. Toxin adsorption experiments were carried out firstly in vitro. These experiments indicated that the absorption efficiency of the peptidoglycan for AFB1 was 64.3-75.9%.3. In the in vivo experiments, Hy-Line Brown chicks were fed a diet containing AFB1 at 71.43 µg/kg with and without peptidoglycan supplementation at concentrations of 100, 200, or 300 g/kg feed from 0-42 d of age.4. The peptidoglycan supplementation in AFB1-contaminated diets resulted in significant improvements in terms of average daily gain, feed intake, feed conversion ratio, white blood cell count, haemoglobin content, glutathione peroxidase activity, immunoglobulin (Ig) A, IgG, IgM and Newcastle disease virus antibody titres (p < 0.05) and diminished liver steatosis.5. In conclusion, peptidoglycan supplementation alleviated AFB1-induced toxicity through adsorbing toxins and improving growth performance, antioxidant ability, immunity and liver pathological changes in chicks. The optimal supplemental dose was 200 mg/kg in feed.

Dietary aflatoxins exposure, environmental enteropathy, and their relation with childhood stunting

Childhood stunting is a global phenomenon affecting more than 149 million children under the age of 5 worldwide. Exposure to aflatoxins (AFs) in utero, during breastfeeding, and consumption of contaminated food affect the gut microbiome, resulting in intestinal dysfunction and potentially contributing to stunting. This review explores the potential relationship between AF exposure, environmental enteropathy and childhood stunting. AFs bind to DNA, disrupt protein synthesis and elicit environmental enteropathy (EE). An EE alters the structure of intestinal epithelial cells, impairs nutrient uptake and leads to malabsorption. This article proposes possible intervention strategies for researchers and policymakers to reduce AF exposure, EE and childhood stunting, such as exposure reduction, the implementation of good agricultural practices, dietary diversification and improving environmental water sanitation and hygiene.

Effects of a Curcumin/Silymarin/Yeast-Based Mycotoxin Detoxifier on Redox Status and Growth Performance of Weaned Piglets under Field Conditions

The aim of this in vivo study was to investigate the effects of a novel mycotoxin detoxifier whose formulation includes clay (bentonite and sepiolite), phytogenic feed additives (curcumin and silymarin) and postbiotics (yeast products) on the health, performance and redox status of weaned piglets under the dietary challenge of fumonisins (FUMs). The study was conducted in duplicate in the course of two independent trials on two different farms. One hundred and fifty (150) weaned piglets per trial farm were allocated into two separate groups: (a) T1 (control group): 75 weaned piglets received FUM-contaminated feed and (b) T2 (experimental group): 75 weaned piglets received FUM-contaminated feed with the mycotoxin-detoxifying agent from the day of weaning (28 days) until 70 days of age. Thiobarbituric acid reactive substances (TBARSs), protein carbonyls (CARBs) and the overall antioxidant capacity (TAC) were assessed in plasma as indicators of redox status at 45 and 70 days of age. Furthermore, mortality and performance parameters were recorded at 28, 45 and 70 days of age, while histopathological examination was performed at the end of the trial period (day 70). The results of the present study reveal the beneficial effects of supplementing a novel mycotoxin detoxifier in the diets of weaners, including improved redox status, potential hepatoprotective properties and enhanced growth performance.

Porcine β-defensin-2 alleviates aflatoxin B1 induced intestinal mucosal damage via ROS-Erk1/2 signaling pathway

Aflatoxin B1 (AFB1) is a highly toxic fungal toxin that causes severe damage to animal intestines. Porcine beta-defensin-2 (pBD-2) is a well-studied antimicrobial peptide in pigs that can protect animal intestines and improve productivity. This study aimed to investigate the molecular mechanisms of pBD-2 in alleviating AFB1-induced oxidative stress and intestinal mucosal damage using porcine intestinal epithelial cells (IPEC-J2 cells) and Kunming (KM) mice. The maximum destructive concentration of AFB1 for IPEC-J2 cells and the optimal therapeutic concentration of pBD-2 were determined by CCK-8 and RT-qPCR. We then investigated the oxidative stress and intestinal damage induced by AFB1 and the alleviating effect of pBD-2 by detecting changes of reactive oxygen species (ROS), inflammatory cytokines, tight junction proteins (TJPs) and mucin. Finally, the molecular mechanism of pBD-2 mitigates AFB1-induced oxidative stress and intestinal mucosal damage were explored by adding ROS and Erk1/2 pathway inhibitors to comparative analysis. In vivo, the therapeutic effect of pBD-2 on AFB1-induced intestinal damage was analyzed from aspects such as average daily gain (ADG), pathological damage, inflammation, and mucosal barrier in KM mice. The study found that low doses of pBD-2 promoted cell proliferation and prevented AFB1-induced cell death, and pBD-2 significantly restored the feed conversion rate and ADG of KM mice reduced by long-term exposed AFB1. Increasing the intracellular ROS and the expression and phosphorylation of Erk1/2, AFB1 promoted inflammation by altering inflammatory cytokines TNF-α, IL-1β, IL-6, and IL-8, and disrupted the mucosal barrier by interfering with Claudin-3, Occludin, and MUC2, while pBD-2 significantly reduced ROS and decreased the expression and phosphorylation of Erk1/2 to restored their expression to alleviate AFB1-induced oxidative stress and intestinal mucosal damage in IPEC-J2 cells and the small intestine of mice.

Ameliorative effects of Sida acuta and vitamin C on serum DNA damage, pro-inflammatory and anti-inflammatory cytokines in roosters fed aflatoxin B1 contaminated diets

The ameliorative effects of Sida acuta leaf meal (SALM) and vitamin C on the serum pro-inflammatory and anti-inflammatory cytokines as well as DNA damage of cocks fed aflatoxin B1 (AFB1) contaminated diets were examined. The experiment was a completely randomized design with a total of 250 sexually mature Isa White cocks aged 24 weeks, randomly allotted into five experimental diets; each diet contained 5 replicates with 10 roosters. The diets were A (control/basal diet), B (A + 1 mg/kg AFB1), C (B + 200 mg/kg vitamin C), D (B + 2.5 g/kg SALM) and E (B + 5.0 g/kg SALM). Fresh and clean water was also provided for the whole experimental period of twelve weeks. Inclusion of 1 mg/kg AFB1 without vitamin C or SALM increased TNF-α and IL-1β as well as 8-OHdG and NF-κB in the serum significantly (P < 0.05) among the cocks on diet B. However, the fortification of AFB1 contaminated diets with vitamin C and SALM depressed serum TNF-α, IL-1β, 8-OHdG and NF-κB concentrations of the cocks significantly (P < 0.05). Conversely, serum IL-4 and IL-10 in birds given 1 mg/kg AFB1 without vitamin C or SALM decreased significantly (P < 0.05) in comparison with the roosters on the control. However, improvements (P < 0.05) in IL-4 and IL-10 concentrations with corresponding reduction (P < 0.05) in TNF-α, IL-1β, 8-OHdG and NF-κB concentrations were recorded among cocks fed Diets C, D and E, respectively. Therefore, dietary addition of SALM at the level used in this study was beneficial and has comparable effects with inorganic antioxidant (C vitamin) by significantly reducing the inflammatory cytokines and oxidative damage biomarkers as well as enhancing the anti-inflammatory cytokines thereby promoting the health status of the cocks fed AFB1 contaminated ration.

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.

Bio-based material-edible rosemary induced biodegradation of aflatoxin B1 via altering endogenous protective enzymes signatures in animal-derived foods

Aflatoxin B1 (AFB1) is the most hazardous mycotoxin, posing risks to public health. Utilization of bio-based materials to biodegrade AFB1 is a green strategy to overcome this issue. The investigation aimed to screen for endogenous protective enzymes in bio-based material-edible rosemary based on ultra-high performance liquid chromatography coupled to hybrid quadrupole-Orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS)-proteomics and ascertain their impacts on the biodegradation and biotransformation of AFB1, and the trade-offs of multilevel metabolism of the animal-derived foods through untargeted metabolomics. The proteomics results verified that bio-based material-edible rosemary (0.20%, w/w) significantly up-regulated glutathione S-transferase and stimulated the down-regulation of cytochrome P450 1A2 levels via activating AhR nuclear translocation in rosemary-pickled AFB1-contaminated goat meat. Metabolomics results demonstrated that edible rosemary substantially increased histidine and glutathione implicated in the antioxidant status of goat meat. More importantly, edible rosemary with high endogenous protective enzyme content could efficiently biodegrade AFB1 in goat meat. We first unveiled that rosemary could not only efficiently biodegrade AFB1 up to 90.20% (20.00-1.96 μg kg^-1) but also elevate the bio-ingestion quality of goat meat. These findings suggest that the bio-based material-rosemary is an efficient and environmentally friendly approach for biodegrading AFB1 and elevating the bio-ingestion composition of goat meat.

Porcine β-defensin-2 alleviates AFB1-induced intestinal mucosal injury by inhibiting oxidative stress and apoptosis

Aflatoxin B1 (AFB1) is the most toxic mycotoxin contaminant, which is widely present in crops and poses a major safety hazard to animal and human health. To alleviate the cytotoxic effects of AFB1 on the intestine, we tested the protective effects of porcine β-defensin-2 (pBD-2). Results demonstrated that pBD-2 inhibited oxidative stress induced by AFB1 via decreasing the levels of ROS and enhancing the expression of antioxidant factors SOD-2 and NQO-1. In addition, pBD-2 attenuated AFB1-induced intestinal porcine epithelial cell line-J2 (IPEC-J2) injury through blocking mitochondria-mediated apoptosis. In vivo, pBD-2 treatment restored the intestinal mucosal structure and reduced the expression levels of apoptosis factors caspase-3 and Bax/Bcl-2. In conclusion, these results indicated that pBD-2 can alleviate AFB1-induced intestinal mucosal injury by inhibiting oxidative stress and mitochondria-mediated apoptosis. This study provides an effective strategy in developing pBD-2 as green feed additive to prevent AFB1 damage to animals.

Protective effects of polydatin on ileum injury in mice exposed to aflatoxin B1

Aflatoxin B1 (AFB1) is an extremely hazardous food/feed pollutant, posing a serious threat to health of human and animals. Particularly, exposure to AFB1 provokes enterocytes oxidative stress and inflammation, which lead to intestinal damage. Polydatin (PD), a stilbenoid glucoside, is known to possess antioxidant and anti-inflammatory properties and is being investigated for use in various disorders. The present study was intended at investigating the protective efficacy of polydatin against AFB1-induced ileum damage in mice. Kunming male mice received oral gavage of AFB1 (300 μg/kg) and PD (100 mg/kg) for 18 days. The results showed that mice exposed to AFB1 exhibited the impaired morphology, the suppressed disaccharidase activities, the down-regulated mRNA expressions of tight junction protein genes, oxidative stress, inflammation and the up-regulated mRNA expressions of genes related to mitophagy in the ileum, whereas PD treatment reversed the AFB1-induced disruption of ileal structure, digestion, barrier function, redox and immune status. The findings of the present study suggested that polydatin may have a potential benefit in preventing AFB1-induced ileum damage.

Zanthoxylum bungeanum as a natural pickling spice alleviates health risks in animal-derived foods via up-regulating glutathione S-transferase, down-regulating cytochrome P450 1A

Endogenous aflatoxin B1 (AFB1) was quantified in five hundred and forty Hengshan goat meat samples (0.00 ± 23.09 μg kg^-1). Zanthoxylum bungeanum (Z. bungeanum), as a natural pickling spice, can ameliorate the flavor of animal-derived food (goat meat). Yet, considering the direct administration of Z. bungeanum in AFB1-contaminated goat meat, the degradation mechanisms of AFB1 remain elusive. Here, UHPLC-Q-Orbitrap HRMS-based integrative metabolomics (LOQ: 1.74-59.54 μg kg^-1) and proteomics analyses were executed to determine the effects of Z. bungeanum in the biotransformation of AFB1. Z. bungeanum (1.50 %, w/w) application mediated the metabolism of xenobiotics by cytochrome P450, significantly down-regulated cytochrome P450 1A and stimulated the up-regulation of glutathione S-transferase levels in AFB1-contaminated goat meat, leading to degradation of AFB1 (20.00-3.39 μg kg^-1). Metabolomics assays indicated that Z. bungeanum up-regulated l-histidine (1.43-2.21 mg kg^-1) and l-arginine, manifesting potential applications for the contribution of Z. bungeanum to the nutritional value of goat meat.

Natural Antioxidant By-Product Mixture Counteracts the Effects of Aflatoxin B1 and Ochratoxin A Exposure of Piglets after Weaning: A Proteomic Survey on Liver Microsomal Fraction

Mycotoxins are toxic compounds produced by certain strains of fungi that can contaminate raw feed materials. Once ingested, even in small doses, they cause multiple health issues for animals and, downstream, for people consuming meat. It was proposed that inclusion of antioxidant-rich plant-derived feed might diminish the harmful effects of mycotoxins, maintaining the farm animals' health and meat quality for human consumption. This work investigates the large scale proteomic effects on piglets' liver of aflatoxin B1 and ochratoxin A mycotoxins and the potential compensatory effects of grapeseed and sea buckthorn meal administration as dietary byproduct antioxidants against mycotoxins' damage. Forty cross-bred TOPIGS-40 hybrid piglets after weaning were assigned to three (n = 10) experimental groups (A, M, AM) and one control group (C) and fed with experimental diets for 30 days. After 4 weeks, liver samples were collected, and the microsomal fraction was isolated. Unbiased label-free, library-free, data-independent acquisition (DIA) mass spectrometry SWATH methods were able to relatively quantify 1878 proteins from piglets' liver microsomes, confirming previously reported effects on metabolism of xenobiotics by cytochrome P450, TCA cycle, glutathione synthesis and use, and oxidative phosphorylation. Pathways enrichment revealed that fatty acid metabolism, steroid biosynthesis, regulation of actin cytoskeleton, regulation of gene expression by spliceosomes, membrane trafficking, peroxisome, thermogenesis, retinol, pyruvate, and amino acids metabolism pathways are also affected by the mycotoxins. Antioxidants restored expression level of proteins PRDX3, AGL, PYGL, fatty acids biosynthesis, endoplasmic reticulum, peroxisome, amino acid synthesis pathways, and, partially, OXPHOS mitochondrial subunits. However, excess of antioxidants might cause significant changes in CYP2C301, PPP4R4, COL18A1, UBASH3A, and other proteins expression levels. Future analysis of proteomics data corelated to animals growing performance and meat quality studies are necessary.

Astaxanthin Alleviates Aflatoxin B1-Induced Oxidative Stress and Apoptosis in IPEC-J2 Cells via the Nrf2 Signaling Pathway

Aflatoxin B1 (AFB1), a typical fungal toxin found in feed, is highly carcinogenic. Oxidative stress is one of the main ways it exerts its toxicity; therefore, finding a suitable antioxidant is the key to reducing its toxicity. Astaxanthin (AST) is a carotenoid with strong antioxidant properties. The aim of the present research was to determine whether AST eases the AFB1-induced impairment in IPEC-J2 cells, and its specific mechanism of action. AFB1 and AST were applied to IPEC-J2 cells in different concentrations for 24 h. The AST (80 µM) significantly prevented the reduction in the IPEC-J2 cell viability that was induced by AFB1 (10 μM). The results showed that treatment with AST attenuated the AFB1-induced ROS, and cytochrome C, the Bax/Bcl2 ratio, Caspase-9, and Caspase-3, which were all activated by AFB1, were among the pro-apoptotic proteins which were diminished by AST. AST activates the Nrf2 signaling pathway and ameliorates antioxidant ability. This was further evidenced by the expression of the HO-1, NQO1, SOD2, and HSP70 genes were all upregulated. Taken together, the findings show that the impairment of oxidative stress and apoptosis, caused by the AFB1 in the IPEC-J2 cells, can be attenuated by AST triggering the Nrf2 signaling pathway.

Hedyotis diffusa alleviate aflatoxin B1-induced liver injury in ducks by mediating Nrf2 signaling pathway

Aflatoxin B1 (AFB1), the most harmful aflatoxins, is a frequent contamination in feed and food items, raising global concerns in animal production and human public health. Also, AFB1 induces oxidative stress, cytotoxicity, mutations, and DNA lesions through its metabolic transformation into aflatoxin B1-8,9-epoxide (AFBO) by cytochrome P450 (CYP450). Hedyotis diffusa (HD) is a traditional Chinese herbal medicine known for its multiple pharmacological activities, including antioxidant, anti-inflammatory, and immunomodulatory. Yet, the influence of HD on AFB1-induced liver injury in ducks is still unknown. Here, we investigated whether HD positively affects AFB1-induced liver injury in ducks. Results revealed that I) AFB1 caused significant changes in serum biochemical indices and decreased growth performance of ducks (such as ALT, AST, ALP, TP, ALB, final body weight, and body weight gain), whereas HD supplementation at 200 mg/kg mitigated these alterations. II) HD alleviated hepatic histopathological changes and liver index induced by AFB1 in ducks. III) HD significantly attenuated AFB1-induced oxidative stress, as measured by increased antioxidant enzyme activities such as SOD, GPx, and T-AOC and decreased MDA levels. Furthermore, HD reduced the level of AFB1-DNA adduct in duck liver. IV) HD significantly promoted the transcriptional expression of NF-E2-related nuclear factor 2 (Nrf2) and associated genes, including heme oxygenase 1 (HO-1), NAD(P)H dehydrogenase quinone 1 (NQO1), glutamate-cysteine ligase catalytic (GCLC). In conclusion, these results demonstrated that HD could activate the Nrf2 pathway in ducks to reduce the hepatotoxicity driven by AFB1. This finding also provides theoretical and data support for a deeper understanding of the toxic mechanisms of AFB1 and its prevention.

Aflatoxin B1 Exposure in Sheep: Insights into Hepatotoxicity Based on Oxidative Stress, Inflammatory Injury, Apoptosis, and Gut Microbiota Analysis

The widespread fungal toxin Aflatoxin B₁ (AFB₁) is an inevitable pollutant affecting the health of humans, poultry, and livestock. Although studies indicate that AFB₁ is hepatotoxic, there are few studies on AFB₁-induced hepatotoxicity in sheep. Thus, this study examined how AFB₁ affected sheep liver function 24 h after the animals received 1 mg/kg bw of AFB₁ orally (dissolved in 20 mL, 4% v/v ethanol). The acute AFB₁ poisoning caused histopathological injuries to the liver and increased total bilirubin (TBIL) and alkaline phosphatase (AKP) levels. AFB₁ also markedly elevated the levels of the pro-inflammatory cytokines TNF-α and IL-6 while considerably reducing the expression of antioxidation-related genes (SOD-1 and SOD-2) and the anti-inflammatory gene IL-10 in the liver. Additionally, it caused apoptosis by dramatically altering the expression of genes associated with apoptosis including Bax, Caspase-3, and Bcl-2/Bax. Notably, AFB₁ exposure altered the gut microbiota composition, mainly manifested by BF311 spp. and Alistipes spp. abundance, which are associated with liver injury. In conclusion, AFB₁ can cause liver injury and liver dysfunction in sheep via oxidative stress, inflammation, apoptosis, and gut-microbiota disturbance.

Effect of aflatoxin B1 exposure on the progression of depressive-like behavior in rats

While it is well documented that aflatoxin B1 (AFB1); one of the most toxic food contaminants is linked to the development of depression. However, the mechanism on how it affects the gut and brain health leading to depressive-like behavior remains unclear. This study was conducted to determine the effect of AFB1 on the progression of depressive-like behavior. Thirty-two (n = 32) male Sprague Dawley rats were randomly allocated into four groups: control, low-dose (5 μg AFB1/kg), high-dose (25 μg AFB1/kg) and positive control group; exposed on chronic unpredictable mild stress (CUMS). After 4 weeks of exposure, sucrose preference test (SPT) and force swim test (FST) were used to measure behavioral despair. Fecal samples were selectively cultured to profile the bacteria. Body weight and relative organs weights were compared among groups. AFB1 and CUMS caused reduction in body weight and food intake as well as increased relative weight of adrenal glands, liver, and brain. Rats in AFB1 and CUMS groups had suppressed sucrose preference and prolonged immobility time in FST, wherein this could indicate anhedonia. Besides, fecal count of Lactobacillus spp. was significantly low following AFB1 exposure, with increasing count of Bifidobacterium spp, in comparison to the control. Indeed, further biochemical analysis and metagenomic approach are warranted to explore the underlying mechanisms on the role of gut microbiota dysbiosis and dysregulation of gut-brain axis due to AFB1 neurotoxicity on the progression of depressive-like behavior.

Variation of Aflatoxin Levels in Stored Edible Seed and Oil Samples and Risk Assessment in the Local Population

Five hundred and twenty samples of edible seeds and oilseeds (sunflower, palm, peanut, sesame, cotton, and grapeseed) were purchased from markets, farmers, and superstores in the central cities of Punjab, Pakistan. A total of 125 (48.1%) edible seed samples from a 6 ≤ months storage period, and 127 (48.8%) from a 2 ≥ years storage period were found to be infested with AFs. The average elevated amount of AFB1 and total AFs was observed in a 2 ≥ years storage period, i.e., 28.6 ± 4.5 and 51.3 ± 10.4 µg/kg, respectively, in sesame seeds. The minimum amount of AFB1 and total AFs was observed in palm seed samples with a storage period of 6 ≤ months, i.e., 9.96 ± 2.4, and 11.7 ± 1.90 µg/kg, respectively. The maximum amount of AFB1 and total AFs were observed in peanut oil samples, i.e., 21.43 ± 2.60 and 25.96 ± 4.30 µg/kg, respectively, with a storage period of 2 ≥ years. Therefore, the maximum dietary intake of 59.60 ng/kg/day was observed in oil samples stored at a ≥ 2 years storage period. The results of the present study concluded that a significant difference was found in the amounts of total AFs in edible seed samples stored at 6 ≤ months and 2 ≥ years storage periods (p < 0.05).

Research progress in toxicological effects and mechanism of aflatoxin B1 toxin

Fungal contamination of animal feed can severely affect the health of farm animals, and result in considerable economic losses. Certain filamentous fungi or molds produce toxic secondary metabolites known as mycotoxins, of which aflatoxins (AFTs) are considered the most critical dietary risk factor for both humans and animals. AFTs are ubiquitous in the environment, soil, and food crops, and aflatoxin B₁(AFB₁) has been identified by the World Health Organization (WHO) as one of the most potent natural group 1A carcinogen. We reviewed the literature on the toxic effects of AFB₁ in humans and animals along with its toxicokinetic properties. The damage induced by AFB₁ in cells and tissues is mainly achieved through cell cycle arrest and inhibition of cell proliferation, and the induction of apoptosis, oxidative stress, endoplasmic reticulum (ER) stress and autophagy. In addition, numerous coding genes and non-coding RNAs have been identified that regulate AFB₁ toxicity. This review is a summary of the current research on the complexity of AFB₁ toxicity, and provides insights into the molecular mechanisms as well as the phenotypic characteristics.

Nutritional impact of mycotoxins in food animal production and strategies for mitigation

Mycotoxins are toxic secondary metabolites produced by filamentous fungi that are commonly detected as natural contaminants in agricultural commodities worldwide. Mycotoxin exposure can lead to mycotoxicosis in both animals and humans when found in animal feeds and food products, and at lower concentrations can affect animal performance by disrupting nutrient digestion, absorption, metabolism, and animal physiology. Thus, mycotoxin contamination of animal feeds represents a significant issue to the livestock industry and is a health threat to food animals. Since prevention of mycotoxin formation is difficult to undertake to avoid contamination, mitigation strategies are needed. This review explores how the mycotoxins aflatoxins, deoxynivalenol, zearalenone, fumonisins and ochratoxin A impose nutritional and metabolic effects on food animals and summarizes mitigation strategies to reduce the risk of mycotoxicity.

Whole-Transcriptome Analysis of Non-Coding RNA Alteration in Porcine Alveolar Macrophage Exposed to Aflatoxin B1

Aflatoxin B1 (AFB1) is a type of mycotoxin produced by the fungi Aspergillus flavus and Aspergillus parasiticus and is commonly found in cereals, oils and foodstuffs. In order to understand the toxic effects of AFB1 exposure on Porcine alveolar macrophages (3D4/2 cell), the 3D4/2 cells were exposed to 40 μg/mL AFB1 for 24 h in vitro, and several methods were used for analysis. Edu and TUNEL analysis showed that the proliferation of 3D4/2 cells was significantly inhibited and the apoptosis of 3D4/2 cells was significantly induced after AFB1 exposure compared with that of the control group. Whole-transcriptome analysis was performed to reveal the non-coding RNA alteration in 3D4/2 cells after AFB1 exposure. It was found that the expression of cell-cycle-related and apoptosis-related genes was altered after AFB1 exposure, and lncRNAs and miRNAs were also significantly different among the experimental groups. In particular, AFB1 exposure affected the expression of lncRNAs associated with cellular senescence signaling pathways, such as MSTRG.24315 and MSTRG.80767, as well as related genes, Cxcl8 and Gadd45g. In addition, AFB1 exposure affected the expression of miRNAs associated with immune-related genes, such as miR-181a, miR-331-3p and miR-342, as well as immune-related genes Nfkb1 and Rras2. Moreover, the regulation networks between mRNA-miRNAs and mRNA-lncRNAs were confirmed by the results of RT-qPCR and immunofluorescence. In conclusion, our results here demonstrate that AFB1 exposure impaired proliferation of 3D4/2 cells via the non-coding RNA-mediated pathway.

Evaluation of Growth Performance, Nitrogen Balance and Blood Metabolites of Mutton Sheep Fed an Ammonia-Treated Aflatoxin B1-Contaminated Diet

Experiments were conducted to evaluate the effects of an aflatoxin B1 (AFB1)-contaminated diet treated with ammonia on the diet detoxification and growth performance, nutrient digestibility, nitrogen utilization, and blood metabolites in sheep. Twenty-four female mutton sheep with an initial body weight of 50 ± 2.5 kg were randomly assigned to one of three groups: (1) control diet (C); (2) aflatoxin diet (T; control diet supplemented with 75 μg of AFB1/kg of dry matter); and (3) ammoniated diet (AT; ammoniated aflatoxin diet). The results showed decreases (p < 0.05) in average daily feed intake, nutrient digestibility of dry matter, crude protein and ether extract, and retained nitrogen, and an increase (p < 0.05) in urine nitrogen excretion in sheep fed diet T compared with those fed the other diets. In comparison to C and AT, feeding T decreased (p < 0.05) the concentrations of total protein, immunoglobulin A, immunoglobulin G, immunoglobulin M, superoxide dismutase, and total antioxidants and increased (p < 0.05) the concentrations of alanine amino transferase, malondialdehyde, and interleukin-6. In summary, ammonia treatment has the potential to decrease the concentration of AFB1 and alleviate the adverse effects of AFB1.

Intestinal Barrier, Claudins and Mycotoxins

The intestinal barrier is the main barrier against all of the substances that enter the body. Proper functioning of this barrier guarantees maintained balance in the organism. Mycotoxins are toxic, secondary fungi metabolites, that have a negative impact both on human and animal health. It was postulated that various mycotoxins may affect homeostasis by disturbing the intestinal barrier. Claudins are proteins that are involved in creating tight junctions between epithelial cells. A growing body of evidence underlines their role in molecular response to mycotoxin-induced cytotoxicity. This review summarizes the information connected with claudins, their association with an intestinal barrier, physiological conditions in general, and with gastrointestinal cancers. Moreover, this review also includes information about the changes in claudin expression upon exposition to various mycotoxins.

Aflatoxins: History, Significant Milestones, Recent Data on Their Toxicity and Ways to Mitigation

In the early 1960s the discovery of aflatoxins began when a total of 100,000 turkey poults died by hitherto unknown turkey "X" disease in England. The disease was associated with Brazilian groundnut meal affected by Aspergillus flavus. The toxin was named Aspergillus flavus toxin-aflatoxin. From the point of view of agriculture, aflatoxins show the utmost importance. Until now, a total of 20 aflatoxins have been described, with B1, B2, G1, and G2 aflatoxins being the most significant. Contamination by aflatoxins is a global health problem. Aflatoxins pose acutely toxic, teratogenic, immunosuppressive, carcinogenic, and teratogenic effects. Besides food insecurity and human health, aflatoxins affect humanity at different levels, such as social, economical, and political. Great emphasis is placed on aflatoxin mitigation using biocontrol methods. Thus, this review is focused on aflatoxins in terms of historical development, the principal milestones of aflatoxin research, and recent data on their toxicity and different ways of mitigation.