Individual and Combined Occurrence of Mycotoxins in Feed Ingredients and Complete Feeds in China

Aggregation-induced emission nanoparticles facilitating multicolor lateral flow immunoassay for rapid and simultaneous detection of aflatoxin B1 and zearalenone

Herein we developed a multicolor lateral flow immunoassay (LFIA) test strip for rapid and simultaneous quantitative detection of aflatoxin B1 (AFB1) and zearalenone (ZEN). Three differently colored aggregation-induced emission nanoparticles (AIENPs) were designed as LFIA signal tags, with red and green AIENPs for targeting AFB1 and ZEN at the test line, and yellow AIENPs for indicating the validity of the test strip at the control (C) line. After surface functionalization with antibodies, the developed AIENP-based multicolor LFIA allows simultaneous and accurate quantification of AFB1 and ZEN using an independent C-line assisted ratiometric signal output strategy. The detection limits of AFB1 and ZEN were 6.12 and 26 pg/mL, respectively. The potential of this method for real-world applications was well demonstrated in corn and wheat. Overall, this multicolor LFIA shows great potential for field screening of multiple mycotoxins and can be extended to rapid and simultaneous monitoring of other small molecule targets.

Individual and combined occurrences of the prevalent mycotoxins in commercial feline and canine food

Mycotoxins, such as aflatoxin B1 (AFB1), deoxynivalenol (DON), fumonisins (FBs), ochratoxin A (OTA), T-2 toxin (T-2), and zearalenone (ZEN), can contaminate animal feeds and pose risks to animal health and production performance. These mycotoxins are commonly found in cereals and grains, with the increased use of cereals in pet food, there is a rising concern about mycotoxin contamination among pet owners. To address this, we analyzed imported brands of feline and canine food from the Chinese market produced in 2021-2022. Ninety-three samples were analyzed, comprising 45 feline food and 48 canine food samples. Among them, 14 were canned food and 79 were dry food. The results indicate that AFB1, DON, FBs, OTA, T-2, and ZEN occurred in 32.26%, 98.92%, 22.58%, 73.12%, 55.91%, and 7.53% of the samples, respectively. The most prevalent mycotoxin was DON, followed by OTA, T-2, AFB1, and FBs, whereas ZEN was less frequently detected. The mean concentrations of the six mycotoxins in pet feed samples were 3.17 μg/kg for AFB1, 0.65 mg/kg for DON, 2.15 mg/kg for FBs, 6.27 μg/kg for OTA, 20.00 μg/kg for T-2, and 30.00 μg/kg for ZEN. The levels of mycotoxins were generally below the limits of the Pet Feed Hygiene Regulations of China and the EU. Notably, a substantial majority of the pet food samples (88 out of 93) were contaminated by two or more mycotoxins. AFB1, FBs, OTA, and ZEN occurred slightly more often in feline food than in canine food. Except for OTA, the contamination rates for the other five mycotoxins in canned food were lower than those in dry food. Moreover, except for AFB1, the levels of the other five mycotoxins in canned foods were lower than those in dry foods. This study highlights the widespread contamination of pet foods with mycotoxins, which poses a significant risk to pets from continuous exposure to multiple mycotoxins.

Effects of hesperidin on mitochondrial function, mitochondria-associated endoplasmic reticulum membranes and IP3R-MCU calcium axis in the intestine of piglets exposed to deoxynivalenol

Deoxynivalenol (DON) pollution is prevalent in crops, and can induce oxidative stress and intestinal injury. Hesperidin is one of the major flavonoids in citrus fruits that has various biological activities such as antioxidant and anti-inflammatory activities. However, whether hesperidin could alleviate DON-induced intestinal injury and the mechanism remain unclear. Mitochondria-associated endoplasmic reticulum (ER) membranes (MAMs) have attracted attention for their crucial signaling points to regulate ER-mitochondria calcium transfer. This study aims to evaluate the effects of hesperidin on the intestinal barrier, mitochondrial function, MAMs, and inositol 1,4,5-triphosphate receptor (IP3R)-mitochondrial calcium uniporter (MCU) calcium axis in the intestine of piglets exposed to DON. Twenty-four piglets were randomly divided into four groups in a 2 × 2 factorial arrangement for a 21-d experiment: Control: basal diet; hesperidin group: basal diet + 300 mg kg-1 hesperidin; DON: basal diet + 1.5 mg kg-1 DON; DON + hesperidin group: basal diet + 1.5 mg kg-1 DON + 300 mg kg-1 hesperidin. The data showed that when compared with the DON group, hesperidin improved growth performance and the intestinal barrier, alleviated intestinal oxidative stress and ER stress, and decreased the serum alanine aminotransferase (ALT) level (P < 0.05). Hesperidin also alleviated mitochondrial dysfunction and ferroptosis in the intestine of piglets exposed to DON (P < 0.05). Importantly, hesperidin prevented excessive MAM formation by downregulating the protein levels of Mitofusin 2 (Mfn2) and glucose-regulated protein 75 (GRP75), decreasing the ratio of the mitochondria with MAMs/total mitochondria and the ratio of MAM length/mitochondrial perimeter and lengthening the mitochondria-ER distance in MAMs (P < 0.05). Furthermore, hesperidin regulated the IP3R-glucose-regulated protein 75 (GRP75)-voltage-dependent anion channel 1 (VDAC1)-MCU calcium axis by decreasing the protein levels of GRP75 and MCU and the calcium level of the mitochondria compared with the DON group (P < 0.05). An in vitro experiment was conducted to further explore whether IP3R-mediated ER-mitochondria calcium transfer was involved in the protective effects of hesperidin on the intestinal epithelium barrier and mitochondria. Data showed that hesperidin may exert protective effects on the intestinal epithelium barrier and mitochondria via inhibiting ER-mitochondrial calcium transfer mediated by IP3Rs. These data suggested that hesperidin could alleviate MAM-mediated mitochondrial calcium overload, thereby improving mitochondrial function and alleviating oxidative stress and intestinal injury in DON-challenged piglets.

The Potential of Multi-Screening Methods and Omics Technologies to Detect Both Regulated and Emerging Mycotoxins in Different Matrices

Mycotoxins are well-known secondary metabolites produced by several fungi that grow and occur in different crops during both pre-harvest and post-harvest conditions. The contamination and occurrence of mycotoxins currently represent some of the major issues in the entire agri-food system. The quantification of mycotoxins in different feeds and foodstuffs is extremely difficult because of the low concentration ranges; therefore, both sample collection and preparation are essential to providing accurate detection and reliable quantification. Currently, several analytical methods are available for the detection of mycotoxins in both feed and food products, and liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS) represents the most reliable instrumental approach. In particular, the fast development of high-throughput methods has made it possible to screen and analyze, in the same analytical run and with high accuracy, multiple mycotoxins, such as those regulated, masked, or modified, and emerging ones. Therefore, the aim of this review is to provide an overview of the state of the art of mycotoxins occurrence, health-related concerns, and analyses, discussing the need to perform multi-screening approaches combined with omics technologies to simultaneously analyze several mycotoxins in different feed and food matrices. This approach is expected to provide more comprehensive information about the profile and distribution of emerging mycotoxins, thus enhancing the understanding of their co-occurrence and impact on the entire production chain.

Microalgae: A promising strategy for aflatoxin control in poultry feeds

Aflatoxins are toxic compounds produced by certain molds, primarily Aspergillus species, which can contaminate crops such as grains and nuts. These toxins pose a significant health risk to animals and humans. Aflatoxin B1 (AFB1) is the most potent of these compounds and has been well-characterized to lead to diminished growth and feed efficiency by disrupting nutrient absorption and metabolism in poultry. AFB1 can trigger apoptosis and inflammation, leading to a decline in immune function and changes in blood biochemistry in poultry. Recently, there has been growing interest in using microalgae as a natural antioxidant to mitigate the effects of aflatoxins in poultry diets. Microalgae have strong antioxidant, antimicrobial, anti-apoptotic, and anti-inflammatory properties, and adding them to aflatoxin-contaminated poultry diets has been shown to improve growth and overall health. This review investigates the potential of microalgae, such as Spirulina platensis, Chlorella vulgaris, and Enteromorpha prolifera, to mitigate AFB1 contamination in poultry feeds. These microalgae contain substantial amounts of bioactive compounds, including polysaccharides, peptides, vitamins, and pigments, which possess antioxidant, antimicrobial, and detoxifying properties. Microalgae can bind to aflatoxins and prevent their absorption in the gastrointestinal tract of poultry. They can also enhance the immune system of poultry, making them more resilient to the toxic effects of AFB1. Based on the data collected, microalgae have shown promising results in combating AFB1 contamination in poultry feeds. They can bind to aflatoxins, boost the immune system, and improve feed quality. This review emphasizes the harmful effects of AFB1 on poultry and the promising role of microalgae in reducing these effects.

Using network pharmacology and molecular docking to uncover the mechanism by which quercetin alleviates deoxynivalenol-induced porcine intestinal injury

Deoxynivalenol is a widespread feed contaminant that leads to vomit, which results in serious symptom such as increased intestinal permeability and even intestinal mucosal necrosis. Recent studies have reported the role of quercetin in alleviating deoxynivalenol-induced intestinal injury; however, the mechanisms and targets remain unclear. Thus, we aimed to identify the mechanisms of action by using a combination of network pharmacology and molecular docking. We identified 151 quercetin targets, 235 deoxynivalenol targets and 47 porcine intestinal injury targets by searching compound database and PubMed database, among which there were two common targets. The PPI network showed that the key proteins involved are NQO1 and PPAR-γ. The PPI network showed that the key proteins involved were NQO1 and PPARG. GO analysis found that genes were enriched primarily in response to oxidative stress. The PPI network showed that the key proteins involved are NQO1 and PPAR-γ. The genes are enriched primarily in response to oxidative stress. KEGG analysis showed enrichment of the HIF, reactive oxygen species and other signaling pathways. The molecular docking results indicated key binding activity between NQO1-quercetin and PPAR-γ-quercetin. By using network pharmacology, we have revealed the potential molecular mechanisms by which quercetin alleviates deoxynivalenol-induced porcine intestinal injury, which lays the foundation for the development of drugs to treat deoxynivalenol-induced intestinal injury in pigs.

Toxicity, biodegradation, and nutritional intervention mechanism of zearalenone

Zearalenone (ZEA), a global mycotoxin commonly found in a variety of grain products and animal feed, causes damage to the gastrointestinal tract, immune organs, liver and reproductive system. Many treatments, including physical, chemical and biological methods, have been reported for the degradation of ZEA. Each degradation method has different degradation efficacies and distinct mechanisms. In this article, the global pollution status, hazard and toxicity of ZEA are summarized. We also review the biological detoxification methods and nutritional regulation strategies for alleviating the toxicity of ZEA. Moreover, we discuss the molecular detoxification mechanism of ZEA to help explore more efficient detoxification methods to better reduce the global pollution and hazard of ZEA.

Effective degradation of zearalenone by dye-decolorizing peroxidases from Pleurotus ostreatus and its metabolic pathway and toxicity analysis

The widespread detection of zearalenone (ZEN) in cereal crops and feeds poses a significant threat to both humans and animals. Consequently, the urgency for the international community to address this issue is evident in the demand for safe and effective measures to mitigate zearalenone contamination and explore detoxification methods. In this study, a dye-decolorizing peroxidase (PoDyP4) from Pleurotus ostreatus is characterized for its impressive ZEN degradation effectiveness. PoDyP4 was demonstrated that the ability to almost completely degrade ZEN at pH 6.0 and 40 °C for 2 h, even at high concentrations of 1 mM. The promotion of enzymatic degradation of ZEN was most pronounced in the presence of Mg2+, while Cu2+ and Fe2+ exhibited a notable inhibitory effect. The degradation mechanism elucidated the detoxification of ZEN by PoDyP4 through hydroxylation and polymerization reactions. The resulting metabolic products displayed significantly reduced toxicity and minimal impact on the viability and apoptosis of mouse spermatocytes GC-2 cells, in comparison to the original ZEN. Hydrophobic contacts and hydrogen bonds were found to be crucial for ZEN-PoDyP4 stability via molecular docking. This finding suggests that PoDyP4 may have a promising application in the field of food and feed for zearalenone detoxification.

An integrated mycotoxin-mitigating agent can effectively mitigate the combined toxicity of AFB1, DON and OTA on the production performance, liver and oviduct health in broiler breeder hens

This study was to evaluate the efficacy of an integrated mycotoxin-mitigating agent in reducing the adverse effects of co-occurring dietary aflatoxin B1 deoxynivalenol and ochratoxin A on broiler breeder hens. 360 30-week-old Hubbard Efficiency Plus broiler breeder hens were allocated into four groups and received a basal diet (BD; Control), BD added 0.15 mg/kg aflatoxin B1+1.5 mg/kg deoxynivalenol+0.12 mg/kg ochratoxin A (Toxins), BD plus Toxins with 0.1% TOXO-XL (Toxins + XL1), and BD plus Toxins with 0.2% TOXO-XL (Toxins + XL2), respectively, for 8 weeks, and then received the same BD for another 4 weeks. Compared with control, mycotoxins decreased total egg weigh, egg laying rate, settable eggs rate, hatch of total eggs rate, egg quality, but increased feed/egg ratio and mortality rate, and impaired the liver and oviduct health during weeks 1-8 and(or) 9-12. It also increased PC and MDA concentrations, TUNEL-positive cells and IL-1β and IL-6 expression, and decreased T-AOC, GPX and CAT activities in liver and/or oviduct. Notably, most of these negative changes were mitigated by both dosages of TOXO-XL. Generally, 0.2% TOXO-XL displayed better mitigation effects than 0.1% TOXO-XL. Conclusively, these findings revealed that TOXO-XL could mitigate the combined mycotoxins-induced toxicity on the performance, liver and oviduct health, through the regulation of redox, immunity, and apoptosis in broiler breeder hens.

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.

Effects of Aflatoxin B1 on growth performance, carcass traits, organ index, blood biochemistry and oxidative status in Chinese yellow chickens

In this study, the effects of different levels of aflatoxin B1 (AFB1) on the growth performance, carcass traits, organ index, blood biochemistry, and antioxidant capacity of yellow-feathered broilers were investigated to provide a reference for the application of AFB1-containing feed ingredients. In this test, yellow-feathered broilers were chosen as the research objects and divided into five treatment groups, with seven replicates in each group and 75 broilers in each replicate. The AFB1 concentration in the diets of groups 1 to 5 were 1.5 μg/kg, 15 μg/kg, 30 μg/kg, 45 μg/kg, and 60 μg/kg, respectively. The results showed that when dietary AFB1 levels were greater than 45 μg/kg, the feed conversion ratios of broilers of 1-21, 22-42, and 43-63 days of age increased (P<0.05). When dietary AFB1 levels were 30 μg/kg, liver glutathione peroxidase (GPx) activity was decreased (P<0.05), and serum transaminase (AST) activity was increased (P<0.05). Overall, dietary AFB1 levels had negative effects on growth performance, antioxidant capacity, blood biochemistry, and liver metabolism in yellow-feathered broilers. Based on using growth performance as the effect index, AFB1 levels in the diets of yellow-feathered broilers should not exceed 45 μg/kg. Based on using antioxidant capacity, liver function, and blood biochemistry as effect indexes, AFB1 levels in the diets of yellow-feathered broilers should not exceed 30 μg/kg.

Yeast polysaccharide mitigated oxidative injury in broilers induced by mixed mycotoxins via regulating intestinal mucosal oxidative stress and hepatic metabolic enzymes

This study was aimed to investigate the effects of yeast polysaccharides (YPS) on growth performance, intestinal health, and aflatoxin metabolism in livers of broilers fed diets naturally contaminated with mixed mycotoxins (MYCO). A total of 480 one-day-old Arbor Acre male broilers were randomly allocated into a 2 × 3 factorial arrangement of treatments (8 replicates with 10 birds per replicate) for 6 wk to assess the effects of 3 levels of YPS (0, 1, or 2 g/kg) on the broilers fed diets contaminated with or without MYCO (95 μg/kg aflatoxin B1, 1.5 mg/kg deoxynivalenol, and 490 μg/kg zearalenone). Results showed that mycotoxins contaminated diets led to significant increments in serum malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels, mRNA expressions of TLR4 and 4EBP1 associated with oxidative stress, mRNA expressions of CYP1A1, CYP1A2, CYP2A6, and CYP3A4 associated with hepatic phase Ⅰ metabolizing enzymes, mRNA expressions of p53 associated with hepatic mitochondrial apoptosis, and AFB1 residues in the liver (P < 0.05); meanwhile dietary MYCO decreased the jejunal villus height (VH), villus height/crypt depth (VH/CD), the activity of serum total antioxidant capacity (T-AOC), mRNA expressions of jejunal HIF-1α, HMOX, and XDH associated with oxidative stress, mRNA expressions of jejunal CLDN1, ZO1, and ZO2, and mRNA expression of GST associated with hepatic phase Ⅱ metabolizing enzymes of broilers (P < 0.05). Notably, the adverse effects induced by MYCO on broilers were mitigated by supplementation with YPS. Dietary YPS supplementation reduced the concentrations of serum MDA and 8-OHdG, jejunal CD, mRNA expression of jejunal TLR2, and 4EBP1, hepatic CYP1A2, and p53, and the AFB1 residues in the liver (P < 0.05), and elevated the serum T-AOC and SOD, jejunal VH, and VH/CD, and mRNA expression of jejunal XDH, hepatic GST of broilers (P < 0.05). There were significant interactions between MYCO and YPS levels on the growth performance (BW, ADFI, ADG, and F/G) at d 1 to 21, d 22 to 42, and d 1 to 42, serum GSH-Px activity, and mRNA expression of jejunal CLDN2 and hepatic ras of broilers (P < 0.05). In contrast with MYCO group, the addition of YPS increased BW, ADFI, and ADG, the serum GSH-Px activity (14.31%-46.92%), mRNA levels of jejunal CLDN2 (94.39%-103.02%), decreased F/G, and mRNA levels of hepatic ras (57.83%-63.62%) of broilers (P < 0.05). In conclusion, dietary supplements with YPS protected broilers from mixed mycotoxins toxicities meanwhile keeping normal performance of broilers, presumably via reducing intestinal oxidative stress, protecting intestinal structural integrity, and improving hepatic metabolic enzymes to minimize the AFB1 residue in the liver and enhance the performance of broilers.

Global distribution, toxicity to humans and animals, biodegradation, and nutritional mitigation of deoxynivalenol: A review

Deoxynivalenol (DON) is one of the main types of B trichothecenes, and it causes health-related issues in humans and animals and imposes considerable challenges to food and feed safety globally each year. This review investigates the global hazards of DON, describes the occurrence of DON in food and feed in different countries, and systematically uncovers the mechanisms of the various toxic effects of DON. For DON pollution, many treatments have been reported on the degradation of DON, and each of the treatments has different degradation efficacies and degrades DON by a distinct mechanism. These treatments include physical, chemical, and biological methods and mitigation strategies. Biodegradation methods include microorganisms, enzymes, and biological antifungal agents, which are of great research significance in food processing because of their high efficiency, low environmental hazards, and drug resistance. And we also reviewed the mechanisms of biodegradation methods of DON, the adsorption and antagonism effects of microorganisms, and the different chemical transformation mechanisms of enzymes. Moreover, nutritional mitigation including common nutrients (amino acids, fatty acids, vitamins, and microelements) and plant extracts was discussed in this review, and the mitigation mechanism of DON toxicity was elaborated from the biochemical point of view. These findings help explore various approaches to achieve the best efficiency and applicability, overcome DON pollution worldwide, ensure the sustainability and safety of food processing, and explore potential therapeutic options with the ability to reduce the deleterious effects of DON in humans and animals.

Toxicokinetics of Deoxynivalenol in Dezhou Male Donkeys after Oral Administration

Deoxynivalenol (DON) is detected in different types of foods and feeds, inducing toxicity in humans and animals. After entering the organism, DON first appears in the plasma; then, it is rapidly absorbed and distributed in various organs and tends to accumulate in the body to exert its toxic effects. This study was performed to investigate the toxicokinetics of DON on Dezhou male donkeys after a single oral dose of 500 μg/kg·BW (body weight). The plasma of donkeys was collected at 0, 5, 10, 15, 20, 30, 45 min, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 6, 9, 12, 24, 48, 72, 96 and 120 h after administration, and the feces and urine were collected at 0 h and at 6 h intervals up to 24 h, followed by 4 h intervals up to 120 h. The concentrations of DON in plasma, urine and feces were determined by HPLC. The peak concentration of DON in plasma was 174.30 μg/L, which occurred at 1.07 h after oral gavage. The recovery of unchanged DON in urine and feces amounted to 19.98% and 6.74%, respectively. Overall, DON was rapidly absorbed and slowly eliminated in donkeys within 120 h following a single oral dose, which can lead to DON accumulation in the body if ingested for a long time.

Metabolic pathway-based self-assembled Au@MXene liver microsome electrochemical biosensor for rapid screening of aflatoxin B1

Cytochrome P450 enzymes (CYPs) catalyze the production of aflatoxin B1 (AFB1) metabolites, which play an important role in carcinogenesis. In this study, we report a simple electrochemical liver-microsome-based biosensor using a composite of gold nanoparticles adsorbed on MXene (Au@MXene) for rapid screening of AFB1. Rat liver microsomes (RLMs) were directly adsorbed on the Au@MXene nanocomposite. The high conductivity, large specific surface area, and good biocompatibility of the Au@MXene nanocomposite enabled the direct electron transfer between the RLMs and the electrode and maintained the biological activity of the enzyme in the RLMs to a large extent. The metabolic behavior of the RLM biosensor that was developed for the electrocatalyst of AFB1 to its hydroxylation metabolite aflatoxin M1 (AFM1) was confirmed. Based on the change in the electrical signal generated by this metabolic behavior, we established the relationship between AFB1 content and amperometric (I-t) current signal. When the AFB1 concentration ranged from 0.01 μM to 50 μM, the AFB1 concentration was linearly related to the electrical signal with a limit of detection of 2.8 nM. The results of the recovery experiments for corn samples showed that the recovery and accuracy of the sensor were consistent with the UPLC-MS/MS method.

Occurrence of Fusarium mycotoxins in freshly harvested highland barley (qingke) grains from Tibet, China

Highland barley, also called "qingke" in Tibetan, is mainly cultivated in the Tibetan Plateau of China and has been used as a major staple food for Tibetans. Recently, Fusarium head blight (FHB) of qingke was frequently observed around the Brahmaputra River in Tibet. Considering the importance of qingke for Tibetans, the assessment of Fusarium mycotoxin contamination is essential for food safety. In this study, a total of 150 freshly harvested qingke grain samples were obtained from three regions around the Brahmaputra River in Tibet (China) in 2020. The samples were investigated for the occurrence of 20 Fusarium mycotoxins using high-performance liquid chromatography-tandem mass spectrometry (HPLC‒MS/MS). The most frequently occurring mycotoxin was enniatin B (ENB) (46%), followed by enniatin B₁ (ENB₁) (14.7%), zearalenone (ZEN) (6.0%), enniatin A₁ (ENA₁) (3.3%), enniatin A (ENA) (1.3%), beauvericin (BEA) (0.7%), and nivalenol (NIV) (0.7%). Due to the increase in altitude, the cumulative precipitation level and average temperature decreased from the downstream to the upstream of the Brahmaputra River; this directly correlated to the contamination level of ENB in qingke, which gradually decreased from downstream to upstream. In addition, the level of ENB in qingke obtained from qingke-rape rotation was significantly lower than that from qingke-wheat and qingke-qingke rotations (p < 0.05). These results disseminated the occurrence of Fusarium mycotoxins and provided further understanding of the effect of environmental factors and crop rotation on Fusarium mycotoxins.

Effects of moldy corn on the performance, antioxidant capacity, immune function, metabolism and residues of mycotoxins in eggs, muscle, and edible viscera of laying hens

Mycotoxins, including aflatoxin B1 (AFB1), zearalenone (ZEN) and deoxynivalenol (DON), are common contaminants of moldy feeds. Mycotoxins can cause deleterious effects on the health of chickens and can be carried over in poultry food products. This study was conducted to investigate the effects of moldy corn (containing AFB1, ZEN, and DON) on the performance, health, and mycotoxin residues of laying hens. One hundred and eighty 400-day-old laying hens were divided into 4 treatments: basal diet (Control), basal diet containing 20% moldy corn (MC20), 40% moldy corn (MC40) and 60% moldy corn (MC60). At d 20, 40, and 60, the performance, oxidative stress, immune function, metabolism, and mycotoxin residues in eggs were determined. At d 60, mycotoxin residues in muscle and edible viscera were measured. Results showed the average daily feed intake (ADFI) and laying performance of laying hens were decreased with moldy corn treatments. All the moldy corn treatments also induced significant oxidative stress and immunosuppression, reflected by decreased antioxidase activities, contents of cytokines, immunoglobulins, and increased malonaldehyde level. Moreover, the activities of aspartate aminotransferase and alanine transaminase were increased by moldy corn treatments. The lipid metabolism was influenced in laying hens receiving moldy corn, reflected by lowered levels of total protein, high density lipoprotein cholesterol, low density lipoprotein cholesterol, total cholesterol, and increased total triglyceride as well as uric acid. The above impairments were aggravated with the increase of mycotoxin levels. Furthermore, AFB1 and ZEN residues were found in eggs, muscle, and edible viscera with moldy corn treatments, but the residues were below the maximum residue limits. In conclusion, moldy corn impaired the performance, antioxidant capacity, immune function, liver function, and metabolism of laying hens at d 20, 40, and 60. Moldy corn also led to AFB1 residue in eggs at d 20, 40, and 60, and led to both AFB1 and ZEN residues in eggs at days 40 and 60, and in muscle and edible viscera at d 60. The toxic effects and mycotoxin residues were elevated with the increase of moldy corn levels in feed.

Effects of Lactic Acid Bacteria Reducing the Content of Harmful Fungi and Mycotoxins on the Quality of Mixed Fermented Feed

The contamination of fermented feeds and foods with fungi and mycotoxins is a major food safety issue worldwide. Certain lactic acid bacteria (LAB), generally recognized as safe (GRAS) fermentation probiotics, are able to reduce microbial and mycotoxins contamination. In this study, Lactiplantibacillus (L.) plantarum Q1-2 and L. salivarius Q27-2 with antifungal properties were screened as inoculants for mixed fermenting feed, and the fermentation and nutritional qualities, microbial community, and mycotoxins of mixed fermented feed were analyzed at different fermentation periods (1, 3, 7, 15, and 30 days, respectively). The findings indicated that the utilization of Q1-2 and Q27-2 strains in fermenting feed led to a decrease in pH and an increase in lactic acid concentration and the proportion of Lactiplantibacillus, while effectively restraining the proliferation of undesirable microorganisms. In particular, Q1-2 reduced the relative abundance of fungi including Fusarium and Aspergillus. Compared to the control group, the Q1-2 and Q27-2 groups reduced aflatoxin B1 by 34.17% and 16.57%, and deoxynivalenol by up to 90.61% and 51.03%. In short, these two LAB inoculants could reduce the contents of aflatoxin B1 and deoxynivalenol to the limited content levels stipulated by the Chinese National Standard GB 13078-2017. These findings suggest that the LAB strains of Q1-2 and Q27-2 have potential applications in the feed industry for the mitigation of mycotoxin pollution, thereby enhancing the quality of animal feed.

Ferroptosis is involved in deoxynivalenol-induced intestinal damage in pigs

BACKGROUND

Deoxynivalenol (DON) is a widespread issue for feed and food safety, leading to animal and human health risks. The objective of this study was to determine whether ferroptosis is involved in DON-induced intestinal injury in piglets. Three groups of 21-day-old male weanling piglets (n = 7/group) were fed a control diet, or diet adding 1.0 or 3.0 mg DON/kg. At week 4, serum and small intestines were collected to assay for biochemistry, histology, redox status and ferroptosis-related genes expression. In addition, the involvement of ferroptosis and the role of FTL gene in DON-induced cell death were further verified in the IPEC-J2 cells.

RESULTS

Compared to the control, dietary supplementation of DON at 1.0 and 3.0 mg/kg induced different degrees of damage in the duodenum, jejunum and ileum, and increased (P < 0.05) serum lipopolysaccharide concentration by 46.2%-51.4%. Dietary DON supplementation at 1.0 and (or) 3.0 mg/kg increased (P < 0.05) concentrations of malondialdehyde (17.4%-86.5%) and protein carbonyl by 33.1%-92.3% in the duodenum, jejunum and ileum. In addition, dietary supplemented with DON upregulated (P < 0.05) ferroptotic gene (DMT1) and anti-ferroptotic genes (FTL and FTH1), while downregulated (P < 0.05) anti-ferroptotic genes (FPN, FSP1 and CISD1) in the duodenum of the porcine. Furthermore, the in vitro study has demonstrated that deferiprone, a potent ferroptotic inhibitor, mitigated (P < 0.05) DON-induced cytotoxicity in porcine small intestinal IPEC-J2 cells. Additionally, deferiprone prevented or alleviated (P < 0.05) the dysregulation of ferroptosis-related genes (ACSL4 and FTL) by DON in IPEC-J2 cells. Moreover, specific siRNA knockdown FTL gene expression compromised the DON-induced cell death in IPEC-J2 cells.

CONCLUSIONS

In conclusion, this study revealed that ferroptosis is involved in DON-induced intestinal damage in porcine, and sheds a new light on the toxicity of DON to piglets.

T-2 toxin-induced intestinal damage with dysregulation of metabolism, redox homeostasis, inflammation, and apoptosis in chicks

T-2 toxin is a worldwide problem for feed and food safety, leading to livestock and human health risks. The objective of this study was to explore the mechanism of T-2 toxin-induced small intestine injury in broilers by integrating the advanced microbiomic, metabolomic and transcriptomic technologies. Four groups of 1-day-old male broilers (n = 4 cages/group, 6 birds/cage) were fed a control diet and control diet supplemented with T-2 toxin at 1.0, 3.0, and 6.0 mg/kg, respectively, for 2 weeks. Compared with the control, dietary T-2 toxin reduced feed intake, body weight gain, feed conversion ratio, and the apparent metabolic rates and induced histopathological lesions in the small intestine to varying degrees by different doses. Furthermore, the T-2 toxin decreased the activities of glutathione peroxidase, thioredoxin reductase and total antioxidant capacity but increased the concentrations of protein carbonyl and malondialdehyde in the duodenum in a dose-dependent manner. Moreover, the integrated microbiomic, metabolomic and transcriptomic analysis results revealed that the microbes, metabolites, and transcripts were primarily involved in the regulation of nucleotide and glycerophospholipid metabolism, redox homeostasis, inflammation, and apoptosis were related to the T-2 toxin-induced intestinal damage. In summary, the present study systematically elucidated the intestinal toxic mechanisms of T-2 toxin, which provides novel ideas to develop a detoxification strategy for T-2 toxin in animals.

Mycotoxin Occurrence in Feeds and Raw Materials in China: A Five-Year Investigation

Mycotoxins are ubiquitously present in feeds and raw materials and can exert toxicity on animals and humans. Therefore, mycotoxin occurrence should be monitored. We report here a multi-mycotoxin survey of feed samples in China from 2017 to 2021. Concentrations of aflatoxins, trichothecenes type B, fumonisins, and zearalenone were determined in a total of 9392 samples collected throughout China. Regional differences and year-to-year variation of mycotoxin occurrence were also assessed in new-season corn. Generally, Fusarium mycotoxins were prevalent, while mycotoxin contamination in each feed commodity showed a distinct pattern, e.g., wheat and bran were typically affected by trichothecenes type B, peanut meals were highly susceptible to aflatoxins, and finished feeds exhibited a comparatively high prevalence of all mycotoxins. In new-season corn, trichothecenes type B and fumonisins were most prevalent, with positive rates of 84.04% and 87.16%, respectively. Regions exhibited different patterns of mycotoxin occurrence. The Anhui and Jiangsu provinces of East China exhibited a high prevalence and concentrations of aflatoxins with a positive rate and a positive average of 82.61% and 103.08 μg/kg, respectively. Central China obtained high fumonisins levels of 4707.84 μg/kg. Trichothecenes type B and zearalenone occurred more frequently in temperate regions of Northeast China, and their positive rates reached 94.99% and 55.67%, respectively. In these regions, mycotoxin concentrations in new-season corn exhibited pronounced year-to-year variations and this could be due to the unusual changes of rainfall or temperature during sensitive periods of corn growing. A large fraction of new-season corn samples contained multiple mycotoxins with two to three classes (75.42%), and the most frequently observed co-contaminants were the combination of trichothecenes type B and fumonisins (73.52%). Trichothecenes type B and zearalenone concentrations were highly positively correlated with a coefficient of 0.775. In conclusion, mycotoxins contamination and co-contamination of feeds are common. Mycotoxin contamination in new-season corn exhibited regional patterns and year-to-year variations, with climate and weather conditions as determinant factors.

Aflatoxin B1 Induces Intestinal Barrier Dysfunction by Regulating the FXR-Mediated MLCK Signaling Pathway in Mice and in IPEC-J2 Cells

Aflatoxin B1 (AFB1) is a widespread mycotoxin in food and feed. Although the liver is the main target organ of AFB1, the intestine is the first exposure organ to AFB1. However, the mechanism by which AFB1 induced intestinal barrier dysfunction via regulating the farnesoid X receptor (FXR)-mediated myosin light chain kinase (MLCK) signaling pathway has rarely been studied. In vivo, AFB1 exposure significantly decreased the small intestine length and increased the intestinal permeability. Meanwhile, AFB1 exposure markedly suppressed the protein expressions of FXR, ZO-1, occludin, and claudin-1 and enhanced the protein expression of MLCK. In vitro, AFB1 exposure induced intestinal barrier dysfunction by the elevation in the FITC-Dextran 4 kDa flux and inhibition in the transepithelial electrical resistance in a dose-dependent manner. In addition, AFB1 exposure downregulated the mRNA and protein expressions of FXR, ZO-1, occludin, and claudin-1, redistributed the ZO-1 protein, and enhanced the protein expressions of MLCK and p-MLC. However, fexaramine (Fex, FXR agonist) pretreatment markedly reversed the AFB1-induced FXR activity reduction, MLCK protein activation, and intestinal barrier impairment in vitro and in vivo. Moreover, pretreatment with the inhibition of MLCK with ML-7 significantly alleviated the AFB1-induced intestinal barrier dysfunction and tight junction disruption in vitro. In conclusion, AFB1 induced intestinal barrier impairment via regulating the FXR-mediated MLCK signaling pathway in vitro and in vivo and provided novel insights to prevent mycotoxin poisoning in the intestine.

Plant-Derived Polyphenols as Nrf2 Activators to Counteract Oxidative Stress and Intestinal Toxicity Induced by Deoxynivalenol in Swine: An Emerging Research Direction

The contamination of deoxynivalenol (DON) in feed is a global problem, which seriously threatens the productivity efficiency and welfare of farm animals and the food security of humans. Pig is the most sensitive species to DON, and is readily exposed to DON through its grain-enriched diet. The intestine serves as the first biological barrier to ingested mycotoxin, and is, therefore, the first target of DON. In the past decade, a growing amount of attention has been paid to plant-derived polyphenols as functional compounds against DON-induced oxidative stress and intestinal toxicity in pigs. In this review, we systematically updated the latest research progress in plant polyphenols detoxifying DON-induced intestinal toxicity in swine. We also discussed the potential underlying mechanism of action of polyphenols as Nrf2 activators in protecting against DON-induced enterotoxicity of swine. The output of this update points out an emerging research direction, as polyphenols have great potential to be developed as feed additives for swine to counteract DON-induced oxidative stress and intestinal toxicity.

Lycopene alleviates multiple-mycotoxin-induced toxicity by inhibiting mitochondrial damage and ferroptosis in the mouse jejunum

Multiple mycotoxins contamination in foods and feeds threatens human and animal health after they accumulate in the food chain, producing various toxic effects. The common mycotoxins contaimination in feeds are zearalenone (ZEN), deoxynivalenol (DON), and aflatoxin B1 (AFB1), but the effects of their co-exposure on the jejunum are not well understood. Lycopene (LYC) has been reported to have antioxidant activity that alleviates jejunal damage. In this study, we investigated the possible role of LYC as a treatment to mitigate the combined effects of ZEN, DON, and AFB1 on the jejunum of mice. Eighty male specific-pathogen-free ICR mice were randomly allocated to treatments with LYC (10 mg kg-1) and/or ZEN + DON + AFB1 (10 mg kg-1 ZEN, 1 mg kg-1 DON, and 0.5 mg kg-1 AFB1). The results indicated that LYC alleviated ZEN + DON + AFB1-induced jejunal injury by ameliorating the jejunal structural injury and increasing the villus height/crypt depth ratio and the levels of tight junction proteins (zonula occludens 1 [ZO1], occludin1 and claudin1) in the mouse jejunum. LYC also inhibited the oxidative stress induced by co-exposure to ZEN, DON, and AFB1 via reducing the levels of reactive oxygen species (ROS) and malondialdehyde (MDA) and enhancing the total antioxidant capacity (T-AOC). LYC also alleviated jejunal mitochondrial damage in the ZEN + DON + AFB1-affected mice, evident as an increase in mitochondrial fission 1 (Fis1) transcription and a reduction in mitochondrial mitofusin 1 (Mfn1) and Mfn2 transcription. Co-exposure to ZEN, DON, and AFB1 also significantly increased the transcription of ferroptosis-related genes (transferrin receptor 1 (Tfr1), ferritin heavy chain 1 [Fth1], solute carrier family 3 member 2 [Slc3a2], and glutathione peroxidase 4 [Gpx4]), TFR1 and Fe2+ concentration. Notably, LYC potentially alleviated ZEN + DON + AFB1-induced jejunal ferroptosis. These results demonstrate that LYC alleviates ZEN + DON + AFB1-induced jejunal toxicity by inhibiting oxidative stress-mediated ferroptosis and mitochondrial damage in mice.

Multiple Mycotoxin Contamination in Medicinal Plants Frequently Sold in the Free State Province, South Africa Detected Using UPLC-ESI-MS/MS

Medicinal plants are important in the South African traditional healthcare system, the growth in the consumption has led to increase in trade through muthi shops and street vendors. Medicinal plants are prone to contamination with fungi and their mycotoxins. The study investigated multiple mycotoxin contamination using Ultra High Pressure Liquid Chromatography-Tandem Mass Spectrometry (UPLC-ESI-MS/MS) for the simultaneous detection of Aflatoxin B1 (AFB1), Deoxynivalenol (DON), Fumonisins (FB1, FB2, FB3), Nivalenol (NIV), Ochratoxin A (OTA) and Zearalenone (ZEN) in frequently sold medicinal plants. Medicinal plant samples (n = 34) were purchased and analyzed for the presence of eight mycotoxins. DON and NIV were not detected in all samples analyzed. Ten out of thirty-four samples tested positive for mycotoxins -AFB1 (10.0%); OTA (10.0%); FB1 (30.0%); FB2 (50.0%); FB3 (20.0%); and ZEN (30.0%). Mean concentration levels ranged from AFB1 (15 µg/kg), OTA (4 µg/kg), FB1 (7-12 µg/kg), FB2 (1-18 µg/kg), FB3 (1-15 µg/kg) and ZEN (7-183 µg/kg). Multiple mycotoxin contamination was observed in 30% of the positive samples with fumonisins. The concentration of AFB1 reported in this study is above the permissible limit for AFB1 (5 µg/kg). Fumonisin concentration did not exceed the limits set for raw maize grain (4000 µg/kg of FB1 and FB2). ZEN and OTA are not regulated in South Africa. The findings indicate the prevalence of mycotoxin contamination in frequently traded medicinal plants that poses a health risk to consumers. There is therefore a need for routine monitoring of multiple mycotoxin contamination, human exposure assessments using biomarker analysis and establishment of regulations and standards.

Toxicity of zearalenone and its nutritional intervention by natural products

Zearalenone (ZEN) is a toxic secondary metabolite mainly produced by fungi of the genus Fusarium, and is often present in various food and feed ingredients such as corn and wheat. The structure of ZEN is similar to that of natural estrogen, and it can bind to estrogen receptors and has estrogenic activity. Therefore, it can cause endocrine-disrupting effects and promote the proliferation of estrogen receptor-positive cell lines. In addition, ZEN can cause oxidative damage, endoplasmic reticulum stress, apoptosis, and other hazards, resulting in systemic toxic effects, including reproductive toxicity, hepatotoxicity, and immunotoxicity. In the past few decades, researchers have tried many ways to remove ZEN from food and feed, but it is still a challenge to eliminate it. In recent years, natural compounds have become of interest for their excellent protective effects on human health from food contaminants. Researchers have discovered that natural compounds often used as dietary supplements can effectively alleviate ZEN-induced systemic toxic effects. Most of the compounds mitigate ZEN-induced toxicity through antioxidant effects. In this article, the contamination of food and feed by ZEN and the various toxic effects and mechanisms of ZEN are reviewed, as well as the mitigation effects of natural compounds on ZEN-induced toxicity.

Evaluation of Hepatic Detoxification Effects of Enteromorpha prolifera Polysaccharides against Aflatoxin B1 in Broiler Chickens

Aflatoxin B₁ (AFB₁) is a major risk factor in animal feed. Seaweed (Enteromorpha prolifera)-derived polysaccharides (SDP) are natural antioxidants with multiple biological functions, which may have an in vivo detoxification effect on AFB₁. The current study aimed to evaluate whether SDP could mitigate AFB₁-induced hepatotoxicity in broilers. A total of 216 chickens (male, 5 weeks old) were randomly allocated to three groups with differing feeding patterns, lasting 4 weeks: (1) control group (CON, fed a basal diet); (2) AFB₁ group (fed a basal diet mixed with 0.1 mg/kg AFB₁); and (3) AFB₁ + SDP group (AFB₁ group + 0.25% SDP). The results showed that dietary SDP improved the liver function-related biochemical indicators in serum, and reversed the increase in relative liver weight, hepatic apoptosis and histological damage of broilers exposed to AFB₁. SDP treatment also reduced the activity and mRNA expression of phase I detoxification enzymes, while increasing the activity and mRNA expression of phase II detoxification enzymes in the livers of AFB₁-exposed broilers, which was involved in the activation of p38 mitogen-activated protein kinase (p38MAPK)/nuclear factor erythroid 2-related factor 2 (Nrf2) signaling. In conclusion, dietary SDP alleviated AFB₁-induced liver injury of broilers through inhibiting phase I detoxification enzymes and upregulating p38MAPK/Nrf2-mediated phase II detoxification enzymes pathway.

Effect of Curcumin as Feed Supplement on Immune Response and Pathological Changes of Broilers Exposed to Aflatoxin B1

In this study, we examined the protective effects of curcumin against the AFB1-induced immune response of and pathological changes in broilers. Histopathology examinations showed that at day 28, AFB1 (5 mg/kg) exposure leads to severe histological changes in the spleen, thymus and bursa of Fabricius with a decrease in the number and karyoplasmic area ratio of plasma cells. Curcumin alleviated the AFB1-induced immune organs’ damage as well as the changes in plasma cells in a dose-dependent manner. RT-PCR data showed that AFB1 significantly downregulated the IL-2 and IFN-γ mRNA expression levels in the thymus, spleen and bursa of Fabricius. However, curcumin supplementation improved the AFB1-induced immune organs’ damage via upregulated cytokines’ expression. Intriguingly, similar trends were noticed in abnormal morphological changes and the immune response at day 35 after the withdrawal of AFB1 and curcumin from the diet, suggesting the protective effects and immunomodulatory function against AFB1 in broilers. The current study provides a scientific experimental basis for the application of curcumin as a therapeutic drug or additive in animal husbandry productive practice.

Development of a reliable UHPLC-MS/MS method for simultaneous determination of zearalenone and zearalenone-14-glucoside in various feed products

A reliable ultra-high-performance liquid chromatography-tandem mass spectrometry method (UHPLC-MS/MS) was developed for the simultaneous determination of two mycotoxins, that is, zearalenone (ZEN) and zearalenone-14-glucoside (ZEN-14G) in formula feed, concentrated feed, and premixed feed products. An improved sample pretreatment was achieved with the hydrophilic-lipophilic balance (HLB) cartridges efficiently removing the impurities and enriching the target analytes in different feeds. The critical parameters affecting the performance of the solid-phase extraction (SPE) procedure were carefully optimized, and 20% acetonitrile in water as the loading solution, 50% methanol in water as the washing solvent, and 5 ml of methanol as the elution solvent yielded the optimal purification efficiencies. The established method was thoroughly validated in terms of linearity (R 2 ≥ 0.999), sensitivity (limit of quantification in the range of 0.50-5.00 μg kg-1), recovery (89.35 ± 2.67% to 110.93 ± 1.56%), and precision (RSD, 3.00-14.20%), and it was then successfully applied to investigate a total of 60 feed samples. Among them, 50 samples were found to be contaminated with ZEN (an incidence of 83.3%) at levels ranging from 0.63 to 615.24 μg kg-1, whereas 22 samples were contaminated with ZEN-14G (an incidence of 36.7%) in the range of 0.89-15.31 μg kg-1. The developed method proved to be a specific and reliable tool for intensive monitoring of ZEN and ZEN-14G in complex feed matrices.

Effects of Intestinal Microorganisms on Metabolism and Toxicity Mitigation of Zearalenone in Broilers

Simple Summary

Zearalenone (ZEN) widely contaminates all the feed crops, and ZEN may cause harmful damage to animals and humans. Different animals have different sensitivity to ZEN. Among these animals, chickens show a strong resistance. Intestinal microorganisms are essential in digestion and degradation. Therefore, we hypothesise whether intestinal microorganisms in chickens play an important role in digesting and degrading ZEN. In this study, we found that intestinal microorganisms could degrade ZEN to a certain degree by both vivo and vitro experiments. We concluded that the intestinal microbiota of broilers had metabolic effects on ZEN and alleviated antioxidant and liver damage caused by ZEN to broilers. Moreover, we found some key bacteria that are important in degrading ZEN.

Abstract

Zearalenone (ZEN) is an estrogenic mycotoxin, and chickens are relatively insensitive to it. In this study, the effects of intestinal microorganisms on ZEN metabolism and toxicity mitigation in broilers were studied by two experiments. Firstly, in vitro, ZEN was incubated anaerobically with chyme from each part of the chicken intestine to study its intestinal microbial metabolism. Then, in vivo, we explored the effects of intestinal microbiota on ZEN by inhibiting intestinal microorganisms. Broilers were fed a control diet, 2.5 mg/kg ZEN diet, microbial inhibition diet or ‘microbial inhibition +2.5 mg/kg ZEN’ diet. In vitro, the results showed that the rates of ZEN degradation by microorganisms in the duodenum, ileum, caecum, and colon were 56%, 12%, 15%, and 17%, respectively, and the microorganisms could convert ZEN into Zearalenol (ZOL). After microbial inhibition in vivo, the content of ZEN and its metabolites in excreta of broilers increased significantly, and antioxidant damage and liver damage were aggravated. 16S rRNA sequencing results showed that antioxidant indices and the content of ZEN and its metabolites in excreta were significantly correlated with the relative abundance of Streptococcus, Lactococcus and Enterococcus, etc. In conclusion, the intestinal microorganisms of broilers play an important role in ZEN metabolism and ZEN-induced antioxidant and liver injury mitigation, among which the key bacteria include Streptococcus, Lactococcus and Enterococcus, etc.

Considerations regarding affinity determinants for aflatoxin B1 in binding cavity of fungal laccase based on in silico mutational and in vitro verification studies

Laccase, a multicopper oxidase, is well known for its industrial potentials to remove environmental pollutants due to its low substrate specificity to oxidize phenols and thus catalytic versatility. Many efforts focused on the metabolic mechanism, yet to decipher the structural determinants responsible for the differentiation between substrates. Aflatoxin B1 (AFB1), a new substrate for laccase, is a mycotoxin with a formidable environmental threat to public health and food safety. In the present study, we combined biochemical, in silico mutational and molecular-docking data to gain an insight to the function of key residues in the active cavity close to the T1 copper site in a characterized recombinant laccase from Cerrena unicolor (rCuL). Kinetic data for computer-assisted virtual mutants established the binding affinity of hydrogen bonds and residues (Asn336, Asp207, Val391, and Thr165) in rCuL to AFB1. The augmented binding affinity to AFB1 may be related to the conformational rearrangements of the laccase and its ability to hydrogen-bond with the substrate. Furthermore, the optimal pH and temperature for rCuL and variants mediated AFB1 degradation may depend on their pH stability and thermostability. Our findings reinforce the importance of the structure-function relationship of fungal laccases in degrading AFB1, providing mechanistic guidance for future biocatalyst and bioengineering applications.

Super-Sensitive LC-MS Analyses of Exposure Biomarkers for Multiple Mycotoxins in a Rural Pakistan Population

High levels of mycotoxin contamination have been reported in various food commodities in Pakistan, however, there has been no exposure assessment study using multiple mycotoxins' biomarkers. This study aimed to simultaneously assess the exposure to the five major mycotoxins: aflatoxin B1 (AFB1), deoxynivalenol (DON), fumonisin B1 (FB1), ochratoxin A (OTA) and zearalenone (ZEN) in a Pakistani population using an integrated approach of human biomonitoring. Human urine samples (n = 292) were analyzed by a super-sensitive liquid-chromatography tandem mass spectrometry (LC-MS/MS) method. Rice and wheat were also collected and analyzed for mycotoxins by the LC-MS/MS method. Food consumption data were collected using a 24 h recall method. A high prevalence of urinary AFM1 (66%, mean ± SD 20.8 ± 41.3 pg/mL) and OTA (99%, 134.7 ± 312.0 pg/mL) were found, whilst urinary DON, FB1 and ZEN levels were low. The probable daily intake (PDI) derived from the urinary biomarkers revealed that 89% of the participants had exposure to OTA exceeding the established tolerable daily intake (TDI = 17 ng/kg bw/day). The average PDI of AFB1 for the studied population was 43 ng/kg bw/day, with rice as the main source of AFB1 exposure. In summary, exposure to AFB1 and OTA are of health concern and require further management.

The preventive effect and mechanisms of adsorbent supplementation in low concentration aflatoxin B1 contaminated diet on subclinical symptom and histological lesions of broilers

This study aimed to investigate the subclinical symptom and histological lesions of 21-day-old and 42-day-old broilers exposure to low concentration aflatoxin B1 (AFB1), and the preventive effect with adsorbent (Toxo-MX) supplementation. A total of 576 one-day-old Arbor Acres broilers were randomly allotted into 6 treatments 8 replicates and 12 birds per cage, fed with 0 ppb, 60 ppb and 120 ppb AFB1 contamination diet with or without Toxo-MX supplementation. Results showed both 60 ppb and 120 ppb AFB1 contamination significantly reduced growth performance in 21-day-old broilers (P < 0.05), but not in 42-day-old broilers (P > 0.05), however, AFB1 contamination in diet caused a higher feed to gain ratio (P < 0.05). Broilers of 21-day-old exposure to 60 ppb and 120 ppb AFB1 increased mRNA expression of hepatic inflammatory cytokines, and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) activity (P < 0.05), 42-day-old broilers showed a same change in 120 ppb but not in 60 ppb of AFB1 contamination (P < 0.05). mRNA expressions of clauding-1, Zonula occludens-1 (ZO-1), and occludin decreased, but Bax, Bcl-2, and caspase-3 increased in 21-day-old broilers exposure to 60 ppb and 120 ppb AFB1 (P < 0.05), broilers of 42-day-old resisted on intestinal aflatoxicosis impairment against 60 ppb AFB1 contamination (P < 0.05), but not in 120 ppb (P < 0.05). Toxo-MX supplementation significantly reversed the detrimental effects on growth performance in both age broilers and reduced the accelerated feed to gain ratio caused by AFB1 (P < 0.05). Intestinal mRNA expression of tight junction and apoptotic genes in both age broilers were recovered by Toxo-MX supplementation (P < 0.05). However, Toxo-MX did not restore the accelerated expression of hepatic inflammation cytokines and SOD, GSH-Px in 120ppb AFB1 group (P < 0.05). The data demonstrated that diet supplementation with Toxo-MX reversed the detrimental effect on growth performance and intestine in broilers exposure to 60 ppb and 120 ppb AFB1. However, did not completely recovered hepatic inflammation induced by AFB1.

Aflatoxin B1 causes oxidative stress and apoptosis in sheep testes associated with disrupting rumen microbiota

Aflatoxin B1 (AFB1) is an unavoidable environmental pollutant commonly found in feed and foodstuffs. It is the most toxic one of all the aflatoxins, which can cause severe impairment to testicular development and function. Yet, the underlying mechanisms of reproductive toxicity in rams sheep remain inconclusive. The study was designed to explore the effects of AFB1 on sheep testes through rumen-microbiota, oxidative stress and apoptosis. Six-month-old male Dorper rams (n = 6) were orally administrated with 1.0 mg/kg AFB1 (dissolved in 20 mL 4% ethanol) 24 h before the experiment. At the same time, rams in the control group (n = 6) were intragastrically administrated with 20 mL 4% ethanol. It was observed that acute AFB1 poisoning had significant (p < 0.05) toxin residue in the testis and could cause testicular histopathological damage. AFB1 stimulated the secretion of plasma testosterone level through regulating testosterone synthesis-related genes (StAR, 3β-HSD, CYP11A1, and CYP17A1), which are accompanied by the increase of oxidative stress and testicular apoptosis that had a close relationship with the regulation of testosterone secretion. Interestingly, we observed rumen dysbacteriosis and decreased the abundances of Prevotella, Succiniclasticum, CF231, Ruminococcus, and Pseudobutyrivibrio in AFB1-exposed sheep, which were negatively correlated to the testosterone synthesis-related gene levels. Taken together, our findings indicated that AFB1 induced testicular damage and testicular dysfunction, which is related to testicular oxidative stress and apoptosis involved in rumen dysbacteriosis in sheep.

Detection and electrocatalytic mechanism of zearalenone using nanohybrid sensor based on copper-based metal-organic framework/magnetic Fe3O4-graphene oxide modified electrode

A novel and simple strategy was proposed for the determination of ZEA in breakfast cereal, maize powder and rice flour using an electrochemical nanohybrid sensor based on copper-based metal-organic framework (Cu-MOF)/magnetic Fe₃O₄-graphene oxide (Fe₃O₄-GO) modified electrode fabricated by the layer-by-layer assembled technique. The synthesized Cu-MOF with high porosity favorably improved the effective surface area and the analytical performance of nanohybrid sensing electrode. The crafted sensor has large surface area, high electron transfer, and satisfactory efficiency. ZEA was electrochemically detected in a wide linear range from 159.2 to 2865.2 ng mL^-1 with LOD of 23.14 ng mL^-1 under the optimal conditions. Moreover, the electrocatalytic mechanism of ZEA oxidation was proposed by density functional theory (DFT). A favorable energetic interaction was presented when Cu-MOF adsorbed on Fe₃O₄-GO, and a small new band appeared on the Fermi level energy (E_f) that facilitated the electron transfer between bands.

A Systematic Review of the Efficacy of Interventions to Control Aflatoxins in the Dairy Production Chain—Feed Production and Animal Feeding Interventions

The study presents a systematic review of published scientific articles investigating the effects of interventions aiming at aflatoxin reduction at the feed production and animal feeding phases of the milk value chain in order to identify the recent scientific trends and summarize the main findings available in the literature. The review strategy was designed based on the guidance of the systematic review and knowledge synthesis methodology that is applicable in the field of food safety. The Web of Science and EBSCOhost online databases were searched with predefined algorithms. After title and abstract relevance screening and relevance confirmation with full-text screening, 67 studies remained for data extraction, which were included in the review. The most important identified groups of interventions based on their mode of action and place in the technological process are as follows: low-moisture production using preservatives, acidity regulators, adsorbents and various microbiological additives. The results of the listed publications are summarized and compared for all the identified intervention groups. The paper aimed to help feed producers, farmers and relevant stakeholders to get an overview of the most suitable aflatoxin mitigation options, which is extremely important in the near future as climate change will likely be accompanied by elevated mycotoxin levels.

Invited review: Remediation strategies for mycotoxin control in feed

Mycotoxins are secondary metabolites of different species of fungi. Aflatoxin B1 (AFB1), deoxynivalenol (DON), zearalenone (ZEN) and fumonisin B1 (FB1) are the main mycotoxins contaminating animal feedstuffs. These mycotoxins can primarily induce hepatotoxicity, immunotoxicity, neurotoxicity and nephrotoxicity, consequently cause adverse effects on the health and performance of animals. Therefore, physical, chemical, biological and nutritional regulation approaches have been developed as primary strategies for the decontamination and detoxification of these mycotoxins in the feed industry. Meanwhile, each of these techniques has its drawbacks, including inefficient, costly, or impractically applied on large scale. This review summarized the advantages and disadvantages of the different remediation strategies, as well as updates of the research progress of these strategies for AFB1, DON, ZEN and FB1 control in the feed industry.

Validation of a New Sensitive Method for the Detection and Quantification of R and S-Epimers of Ergot Alkaloids in Canadian Spring Wheat Utilizing Deuterated Lysergic Acid Diethylamide as an Internal Standard

Ergot sclerotia effect cereal crops intended for consumption. Ergot alkaloids within ergot sclerotia are assessed to ensure contamination is below safety standards established for human and animal health. Ergot alkaloids exist in two configurations, the R and S-epimers. It is important to quantify both configurations. The objective of this study was to validate a new ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method for quantification of six R and six S-epimers of ergot alkaloids in hard red spring wheat utilizing deuterated lysergic acid diethylamide (LSD-D3) as an internal standard. Validation parameters such as linearity, limit of detection (LOD), limit of quantification (LOQ), matrix effects, recovery and precision were investigated. For the 12 epimers analyzed, low LOD and LOQ values were observed, allowing for the sensitive detection of ergot epimers. Matrix effects ranged between 101-113% in a representative wheat matrix. Recovery was 68.3-119.1% with an inter-day precision of <24% relative standard deviation (RSD). The validation parameters conform with previous studies and exhibit differences between the R and S-epimers which has been rarely documented. This new sensitive method allows for the use of a new internal standard and can be incorporated and applied to research or diagnostic laboratories.

Comparison of Ameliorative Effects between Probiotic and Biodegradable Bacillus subtilis on Zearalenone Toxicosis in Gilts

This study was conducted to compare the potential ameliorative effects between probiotic Bacillus subtilis and biodegradable Bacillus subtilis on zearalenone (ZEN) toxicosis in gilts. Thirty-six Landrace×Yorkshire gilts (average BW = 64 kg) were randomly divided into four groups: (1) Normal control diet group (NC) fed the basal diet containing few ZEN (17.5 μg/kg); (2) ZEN contaminated group (ZC) fed the contaminated diet containing an exceeded limit dose of ZEN (about 300 μg/kg); (3) Probiotic agent group (PB) fed the ZC diet with added 5 × 10⁹ CFU/kg of probiotic Bacillus subtilis ANSB010; (4) Biodegradable agent group (DA) fed the ZC diet with added 5 × 10⁹ CFU/kg of biodegradable Bacillus subtilis ANSB01G. Results showed that Bacillus subtilis ANSB010 and ANSB01G isolated from broiler intestinal chyme had similar inhibitory activities against common pathogenic bacteria. In addition, the feed conversion ratio and the vulva size in DA group were significantly lower than ZC group (p < 0.05). The levels of IgG, IgM, IL-2 and TNFα in the ZC group were significantly higher than PB and DA groups (p < 0.05). The levels of estradiol and prolactin in the ZC group was significantly higher than those of the NC and DA groups (p < 0.05). Additionally, the residual ZEN in the feces of the ZC and PB groups were higher than those of the NC and DA groups (p < 0.05). In summary, the ZEN-contaminated diet had a damaging impact on growth performance, plasma immune function and hormone secretion of gilts. Although probiotic and biodegradable Bacillus subtilis have similar antimicrobial capacities, only biodegradable Bacillus subtilis could eliminate these negative effects through its biodegradable property to ZEN.

Isoflavones in Animals: Metabolism and Effects in Livestock and Occurrence in Feed

Soybeans are a common ingredient of animal feed. They contain isoflavones, which are known to act as phytoestrogens in animals. Isoflavones were described to have beneficial effects on farm animals. However, there are also reports of negative outcomes after the consumption of isoflavones. This review summarizes the current knowledge of metabolization of isoflavones (including the influence of the microbiome, phase I and phase II metabolism), as well as the distribution of isoflavones and their metabolites in tissues. Furthermore, published studies on effects of isoflavones in livestock species (pigs, poultry, ruminants, fish) are reviewed. Moreover, published studies on occurrence of isoflavones in feed materials and co-occurrence with zearalenone are presented and are supplemented with our own survey data.

Optimization of the QuEChERS-Based Analytical Method for Investigation of 11 Mycotoxin Residues in Feed Ingredients and Compound Feeds

Mycotoxins are toxic substances naturally produced by various fungi, and these compounds not only inflict economic damage, but also pose risks to human and animal health. The goal of the present study was to optimize the QuEChERS-based extraction and liquid chromatography–tandem mass spectrometry (LC–MS/MS) method for the analysis of 11 mycotoxins, such as aflatoxins (AFs), ochratoxin A (OTA), fumonisins (FBs), T-2 toxin, HT-2 toxin, zearalenone (ZEN), and deoxynivalenol (DON), commonly found in feed. The QuEChERS method, characterized by being “quick, easy, cheap, effective, rugged, and safe”, has become one of the most common extractions and clean-up procedures for mycotoxin analyses in food. Therefore, in this experiment, an optimal method for the analysis of 11 mycotoxins in feed was established by modifying the general QuEChERS method. In this process, it was confirmed that even if feed samples of different weights were extracted, the quantitative value of mycotoxins in the feed was not affected. To reduce matrix effects, 13C-labeled compounds and deuterium were used as internal standards. This optimized method was then applied in the determination of 11 mycotoxins in 736 feed ingredients and compound feeds obtained from South Korea. The results showed that the occurrence rates of FBs, ZEN, and DON were 59.4%, 38.0%, and 32.1%, respectively, and OTA, AFs, and T-2 toxin and HT-2 toxin were found in fewer than 1% of the 736 feeds. The mean concentration ranges of FBs, ZEN, and DON were 757–2387, 44–4552, and 248–9680 μg/kg, respectively. Among the samples in which DON and ZEN were detected, 10 and 12 samples exceeded the management recommendation standards presented by the Ministry of Agriculture, Food and Rural Affairs (MAFRA). However, when the detected concentrations of DON and ZEN were compared with guideline levels in foreign countries, such as the US, Japan, China, and the EU, the number of positive samples changed. In addition, the co-occurrence of mycotoxins in the feed was analyzed, and the results showed that 43.8% of the samples were contaminated with two or three mycotoxins, among which the co-occurrence rate of FBs, ZEN, and DON was the highest. In conclusion, these results suggest the need for stricter management standards for FBs, DON, and ZEN in South Korea, and emphasize the importance of the continuous monitoring of feeds.

Baicalin-Zinc Complex Alleviates Inflammatory Responses and Hormone Profiles by Microbiome in Deoxynivalenol Induced Piglets

This study aimed to investigate the beneficial effect of baicalin–zinc complex (BZN) on intestinal microorganisms in deoxynivalenol (DON)-challenged piglets and the association between intestinal microorganisms and host immunity and hormone secretion. Forty weaned piglets were randomly divided into four treatments with 10 piglets in each treatment: (1) control (Con) group (pigs fed basal diet); (2) DON group (pigs fed 4 mg DON/kg basal diet); (3) BZN group (pigs fed 0.5% BZN basal diet); and (4) DBZN group (pigs fed 4 mg DON/kg and 0.5% BZN basal diet). The experiment lasted for 14 days. The BZN supplementation in DON-contaminated diets changed the intestinal microbiota composition and increased intestinal microbial richness and diversity of piglets. The BZN supplementation in DON-contaminated diets also alleviated the inflammatory responses of piglets and modulated the secretion of hormones related to the growth axis. Moreover, microbiota composition was associated with inflammatory and hormone secretion. In conclusion, BZN alleviated inflammatory response and hormone secretion in piglets, which is associated with the intestinal microbiome.