Enzymatic hydrolysis of fumonisins in the gastrointestinal tract of broiler chickens

Involvement of aryl hydrocarbon receptor in the aflatoxin B1 and fumonisin B1 effects on in vitro differentiation of murine regulatory-T and Th17 cells

Aflatoxin B1 (AFB1) and fumonisin B1 (FB1) are mycotoxins widely found as cereal contaminants, and their co-consumption is associated with liver cancer. Both are immunotoxic, but their interactions have been little studied. This work was aimed to evaluate in mouse spleen mononuclear cells (SMC) the effects of the exposure to AFB1 (5-50 µM), FB1 (25-250 µM), and AFB1-FB1 mixtures (MIX) on the in vitro differentiation of regulatory T cells (Treg and Tr1-like) and Th17 cells, as well as elucidate the contribution of aryl hydrocarbon receptor (Ahr) in such effects. AFB1 and mainly MIX induced cytotoxicity in activated CD4 cells via Ahr signaling. AFB1 (5 µM) increased the Treg cell differentiation, but its combination with FB1 (25 µM) also reduced Th17 cell expansion by Ahr-dependent mechanisms. Therefore, this mixture could enhance the Treg/Th17 cell ratio and favor immunosuppression and escape from tumor immunosurveillance to a greater extent than individual mycotoxins. Whereas, AFB1-FB1 mixtures at medium-high doses inhibited the Tr1-like cell expansion induced by the individual mycotoxins and affected Treg and Th17 cell differentiation in Ahr-independent and dependent manners, respectively, which could alter anti-inflammatory and Th17 immune responses. Moreover, individual FB1 altered regulatory T and Th17 cell development independently of Ahr. In conclusion, AFB1 and FB1 interact by modifying Ahr signaling, which is involved in the immunotoxicity as well as in the alteration of the differentiation of Treg, Tr1-like, and Th17 cells induced by AFB1-FB1 mixtures. Therefore, Ahr is implicated in the regulation of the anti- and pro-inflammatory responses caused by the combination of AFB1 and FB1.

The occurrence and management of fumonisin contamination across the food production and supply chains

BACKGROUND

Fumonisins (FUMs) are among the most common mycotoxins in plant-derived food products. FUMs contamination has considerably impacted human and animal health, while causing significant economic losses. Hence, management of FUMs contamination in food production and supply chains is needed. The toxicities of FUMs have been widely investigated. FUMs management has been reported and several available strategies have been developed successfully to mitigate FUMs contamination present in foods. However, currently available management of FUMs contamination from different phases of food chains and the mechanisms of some major strategies are not comprehensively summarized.

AIM OF REVIEW

This review comprehensively characterize the occurrence, impacts, and management of FUMs contamination across food production and supply chains. Pre- and post-harvest strategies to prevent FUMs contamination also are reviewed, with an emphasis on the potential applications and the mechanisms of major mitigation strategies. The presence of modified FUMs products and their potential toxic effects are also considered. Importantly, the potential application of biotechnological approaches and emerging technologies are enunciated.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Currently available pre- and post-harvest management of FUMs contamination primarily involves prevention and decontamination. Prevention strategies are mainly based on limiting fungal growth and FUMs biosynthesis. Decontamination strategies are implemented through alkalization, hydrolysis, thermal or chemical transformation, and enzymatic or chemical degradation of FUMs. Concerns have been raised about toxicities of modified FUMs derivatives, which presents challenges for reducing FUMs contamination in foods with conventional methodologies. Integrated prevention and decontamination protocols are recommended to control FUMs contamination across entire value chains in developed countries. In developing countries, several other approaches, including cultivating, introducing Bt maize, simple sorting/cleaning, and dehulling, are suggested. Future studies should focus on biotechnological approaches, emerging technologies, and metagenomic/genomic identification of new degradation enzymes that could allow better opportunities to manage FUMs contamination in the entire food system.

Effects of Aflatoxins and Fumonisins, Alone or in Combination, on Performance, Health, and Safety of Food Products of Broiler Chickens, and Mitigation Efficacy of Bentonite and Fumonisin Esterase

The current study evaluated the effects of feeding diets contaminated with aflatoxin B1 (AFB1), fumonisins (FBs), or both on the performance and health of broiler chickens and the safety of their food products as well as the efficacy of bentonite and fumonisin esterase to mitigate the effects of these mycotoxins under conditions representative for sub-Saharan Africa (SSA). Four hundred one-day-old Cobb 500 broiler chickens were randomly assigned to 20 treatments with either a control diet, a diet with moderate AFB1 (60 μg/kg feed) or high AFB1 (220 μg/kg feed), or FBs (17,430 μg FB1+FB2/kg feed), alone or in combination, a diet containing AFB1 (either 60 or 220 μg/kg) and/or FBs (17,430 μg FB1+FB2/kg) and bentonite or fumonisin esterase or both, or a diet with bentonite or fumonisin esterase only. The experimental diets were given to the birds from day 1 to day 35 of age, and the effects of the different treatments on production performance were assessed by feed intake (FI), body weight gain (BWG), and feed conversion ratio (FCR). Possible health effects were evaluated through blood biochemistry, organ weights, mortality, liver gross pathological changes, and vaccine response. Residues of aflatoxins (AFB1, B2, G1, G2, M1 and M2) were determined in plasma, muscle, and liver tissues using validated UHPLC-MS/MS methods. The results obtained indicated that broiler chickens fed high AFB1 alone had poor FCR when compared to a diet with both high AFB1 and FBs (p = 0.0063). Serum total protein and albumin from birds fed FBs only or in combination with moderate or high AFB1 or detoxifiers increased when compared to the control (p < 0.05). Liver gross pathological changes were more pronounced in birds fed contaminated diets when compared to birds fed the control or diets supplemented with mycotoxin detoxifiers. The relative weight of the heart was significantly higher in birds fed high AFB1 and FBs when compared to the control or high AFB1 only diets (p < 0.05), indicating interactions between the mycotoxins. Inclusion of bentonite in AFB1-contaminated diets offered a protective effect on the change in weights of the liver, heart and spleen (p < 0.05). Residues of AFB1 were detected above the limit of quantification (max: 0.12 ± 0.03 μg/kg) in liver samples only, from birds fed a diet with high AFB1 only or with FBs or the detoxifiers. Supplementing bentonite into these AFB1-contaminated diets reduced the levels of the liver AFB1 residues by up to 50%. Bentonite or fumonisin esterase, alone, did not affect the performance and health of broiler chickens. Thus, at the doses tested, both detoxifiers were safe and efficient for use as valid means of counteracting the negative effects of AFB1 and FBs as well as transfer of AFB1 to food products (liver) of broiler chickens.

Ameliorative Effects of Luteolin and Activated Charcoal on Growth Performance, Immunity Function, and Antioxidant Capacity in Broiler Chickens Exposed to Deoxynivalenol

Deoxynivalenol (DON, Vomitoxin) is a threatening mycotoxin that mainly produces oxidative stress and leads to hepatotoxicity in poultry. Antioxidant dietary supplements dramatically boost immunity, safeguarding animals from DON poisoning. Luteolin (LUT) is an active plant-derived compound that poses influential antioxidants. This study explored the effectiveness of LUT in combination with activated charcoal (AC) in detoxifying DON in broilers. The 180 one-day broiler chickens were allocated into five different groups having six replicates in each group, provided with ad libitum feed during the trial period (28 days) as follows: in the control group, basal diet (feed with no supplementation of LUT, AC or DON); in group 2, a basal diet added with 10 mg/kg DON from contaminated culture (DON); in group 3, a basal diet augmented by 350 mg/kg LUT and DON 10 mg/kg (DON + LUT); in group 4, a basal diet supplemented by DON 10 mg/kg + AC 200 mg/kg (DON + AC); and in group 5, a basal diet supplemented by 10 mg/kg DON + 350 mg/kg LUT + 200 mg/kg AC (DON + LUT + AC). Concerning the control group, the DON-treated broilers demonstrated a significant decrease in growth performance (p < 0.05) and serum immunoglobulin (p < 0.05) contents, negatively changing the serum biochemical contents and enzymatic activities and an increase in histopathological liver lesions. Furthermore, DON substantially increased (p < 0.05) malondialdehyde (MDA) concentration and decreased total superoxide dismutase (T-SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) levels in the serum and liver. The intake of AC and LUT to the DON-contaminated diet decreased DON residue in the liver and potentially reduced the adverse effects of DON. Considering the results, supplementation of LUT with mycotoxin adsorbent has protective effects against mycotoxicosis caused by DON. It could be helpful for the development of novel treatments to combat liver diseases in poultry birds. Our findings may provide important information for applying LUT and AC in poultry production.

Post-Harvest Prevention of Fusariotoxin Contamination of Agricultural Products by Irreversible Microbial Biotransformation: Current Status and Prospects

Biological degradation of mycotoxins is a promising environmentally-friendly alternative to chemical and physical detoxification methods. To date, a lot of microorganisms able to degrade them have been described; however, the number of studies determining degradation mechanisms and irreversibility of transformation, identifying resulting metabolites, and evaluating in vivo efficiency and safety of such biodegradation is significantly lower. At the same time, these data are crucial for the evaluation of the potential of the practical application of such microorganisms as mycotoxin-decontaminating agents or sources of mycotoxin-degrading enzymes. To date, there are no published reviews, which would be focused only on mycotoxin-degrading microorganisms with the proved irreversible transformation of these compounds into less toxic compounds. In this review, the existing information about microorganisms able to efficiently transform the three most common fusariotoxins (zearalenone, deoxinyvalenol, and fumonisin B1) is presented with allowance for the data on the corresponding irreversible transformation pathways, produced metabolites, and/or toxicity reduction. The recent data on the enzymes responsible for the irreversible transformation of these fusariotoxins are also presented, and the promising future trends in the studies in this area are discussed.

Drug-independent control strategy of clostridial infection in broiler chickens using anti-toxin environmentally friendly multienzymes

The study investigated the effect of enzymes as a toxin detoxifier (DETOXIZYME) dietary supplementation on performance during growth, blood chemistry, and immunity under clostridia infection in chickens. A total of 480, day-old male chicks were randomly distributed to four groups, with six replicates of 20 birds each. The first control negative treatment (A) fed the basal formula as commercial feed prepared following the strain's needs, the second control positive group (B) fed the basal formula challenged with Clostridium perfringens (C. perfringens) type A, the third group (C) fed the basal formula with 100 g DETOXIZYME/ton of feed and challenged with clostridia, and the fourth group (D) fed the control basal formula with 100 g DETOXIZYME/ton of feed. DETOXIZYME dietary supplementation significantly boosted body weight (BW), body weight gain (BWG), feed intake (FI), and European production efficiency factor (EPEF) and improved the feed conversion rate (FCR) of the broilers. The dietary supplementation of DETOXIZYME significantly increased carcass trait and spleen. However, liver and abdominal fat weight significantly decreased compared with clostridia-challenged groups. The values of alanine aminotransferase (ALT), aspartate aminotransferase (AST), uric acid, creatinine, and Malondialdehyde (MDA) were decreased. While calcium, phosphate, zinc, and glutathione peroxidase (GPx) levels were improved in birds that took basal formulas fortified with DETOXIZYME contrary to the other treatment groups during 35 days of age. Plasma total cholesterol, triglyceride, and low-density lipoprotein (LDL) values were reduced versus the other treatment groups. Dietary supplementation of DETOXIZYME increased total protein, albumin, globulin, and Newcastle Disease (ND) immunity titer levels in the overall period compared to other groups. Dietary DETOXIZYME supplementation decreased clostridia and E. coli bacteria counts and improved gut morphometry. In conclusion, dietary supplementation of DETOXIZYME had a positive impact on performance, blood biochemistry, immunity, and bacterial counts and improved the gut morphology in broilers under clostridia infection.

Subclinical doses of dietary fumonisins and deoxynivalenol cause cecal microbiota dysbiosis in broiler chickens challenged with Clostridium perfringens

Fusarium toxins are one of the most common contaminants in poultry diets. The co-occurrence of fumonisins (FUM) and deoxynivalenol (DON), even at a subclinical dose, negatively affects the growth performance, intestinal integrity and induce subclinical necrotic enteritis in broiler chickens. Loss of gut integrity can be expected to alter the intestinal microbiota’s composition. The objective of this study was to identify the effects of combined FUM and DON on the cecal microbiome profile and predicted metabolic functions and a short chain fatty acid profile in broilers challenged with Clostridium perfringens. A total of 240 1 day-old chicks were randomly assigned to two treatments: a control diet and the control diet with 3 mg/kg FUM + 4 mg/kg DON each with eight replications. All the birds were received cocci vaccine at d0. All birds in both treatment groups were challenged with C. perfringens 1 × 108 CFU via feed on d 19 and 20 to achieve 5% mortality. On d 35, the FUM and DON contaminated diet numerically (P = 0.06) decreased the body weight gain (BWG) by 84 g compared to the control group. The bacterial compositions of the cecal contents were analyzed by sequencing the V3–V4 region of the 16S rRNA gene. Overall, microbial richness and diversity increased (P &lt; 0.02) during the studied period (d 21–35). Cecal contents of birds in the FUM + DON group had greater (P &lt; 0.05) microbial evenness and diversity (Shannon index) compared to the control group. FUM + DON exposure decreased (P = 0.001) the relative abundance of Proteobacteria in the cecal content, compared to the control group. The combined FUM + DON significantly increased the relative abundance of the Defluviitaleaceae and Lachnospiraceae families (P &lt; 0.05) but decreased the abundances of the Moraxellaceae and Streptococcaceae (P &lt; 0.05) compared to the control group birds. At the genus level, FUM + DON exposure decreased (P &lt; 0.05) Acinetobacter and Pseudomonas abundance and had a tendency (P = 0.08) to decrease Thermincola abundance compared to the control group. In the ileum, no NE-specific microscopic abnormalities were found; however, the tip of the ileal villi were compromised. The present findings showed that dietary FUM and DON contamination, even at subclinical levels, altered cecal microbial composition, dysregulated intestinal functions, and impaired the gut immune response, potentially predisposing the birds to necrotic enteritis.

Short-term exposure to fumonisins and deoxynivalenol, on broiler growth performance and cecal Salmonella load during experimental Salmonella Enteritidis infection

Fumonisins (FUM) and deoxynivalenol (DON) are two common mycotoxins in poultry feed. Salmonella enterica ser. Enteritidis (S. Enteritidis) is a primary foodborne bacterium in broilers. This trial was conducted to evaluate the effects of naturally occurring FUM and DON and their combination at subclinical doses on broiler performance during a S. Enteritidis challenge. The experiment consisted of five treatments: NCC, no-challenge no-mycotoxin treatment; CC, Salmonella challenge + no-mycotoxin treatment; DON, DON 0.6 mg/kg + Salmonella challenge; FUM, FUM 14 mg/kg + Salmonella challenge; DON + FUM + T-2 + neosolaniol, DON 0.6 mg/kg + FUM 14 mg/kg + T-2 toxin 0.6 mg/kg + 0.8 mg/kg neosolaniol + Salmonella challenge. On d 4, birds were challenged with either 0 or 1 × 10⁹ CFU/mL S. Enteritidis orally. There were no significant effects on growth performance among treatments at 0, 3, 7, and 14 d of post-inoculation (dpi). On 14 dpi, the combined DON + FUM + T-2 + neosolaniol significantly increased the Salmonella load by 1.5 logs compared to the control groups (P < 0.05). FUM significantly increased the cecal tonsil IL-10 gene expression by 1.2-fold at 7 dpi (P < 0.05) and downregulated TNF-α by 1.8-fold on 14 dpi compared to the control, nonchallenge groups (P < 0.05). On 7 dpi, the combined DON + FUM + T-2 + neosolaniol reduced occludin by 4.4-fold (P < 0.05) when compared to the control groups. Similarly, combined DON + FUM+ T-2 + neosolaniol decreased zona-occluden transcription by 2.3 and 7.6-fold on 3 and 14 dpi, respectively (P < 0.05). Furthermore, combined DON + FUM + T-2 + neosolaniol decreased Claudin-1 by 2.2-fold and Claudin-4 by 5.1-fold on 14 dpi when compared to the control groups (P < 0.05). In conclusion, short-term exposure to a subclinical dose of combined DON + FUM + T-2 + neosolaniol had an impact on broiler intestinal tight junction proteins and cecal Salmonella abundance under experimental Salmonella challenge.

The natural occurrence, toxicity mechanisms and management strategies of Fumonisin B1：A review

Fumonisin B1 (FB1) contaminates various crops, causing huge losses to agriculture and livestock worldwide. This review summarizes the occurrence regularity, toxicity, toxic mechanisms and management strategies of FB1. Specifically, FB1 contamination is particularly serious in developing countries, humid and hot regions. FB1 exposure can produce different toxic effects on the nervous system, respiratory system, digestive system and reproductive system. Furthermore, FB1 can also cause systemic immunotoxicity. The mechanism of toxic effects of FB1 is to interfere with the normal pathway of sphingolipid de novo biosynthesis by acting as a competitive inhibitor of ceramide synthase. Meanwhile, the toxic products of sphingolipid metabolic disorders can cause oxidative stress and apoptosis. FB1 also often causes feed contamination by mixing with other mycotoxins, and then exerts combined toxicity. For detection, lateral flow dipstick technology and enzyme linked immunosorbent assay are widely used in the detection of FB1 in commercial feeds, while mainstream detection methods such as high performance liquid chromatography and liquid chromatography-mass spectrometry are widely used in the laboratory theoretical study of FB1. For purification means of FB1, some natural plant extracts (such as Zingiber officinale and Litsea Cubeba essential oil) and their active compounds have been proved to inhibit the toxic effects of FB1 and protect livestock due to their antifungal and antioxidant effects. Natural plant extract has the advantages of high efficiency, low cost and no contamination residue. This review can provide information for comprehensive understanding of FB1, and provide reference for formulating reasonable treatment and management strategies in livestock production.

Assessment of information as regards the toxicity of fumonisins for pigs, poultry and horses

In 2018, the EFSA Panel on Contaminants in the Food Chain (CONTAM) adopted a Scientific Opinion on the risks for animal health related to the presence of fumonisins, their modified forms and hidden forms in feed. A no observed adverse effect level (NOAEL) of 1 mg/kg feed was established for pigs. In poultry a NOAEL of 20 mg/kg feed and in horses a reference point for adverse animal health effect of 8.8 mg/kg feed was established, referred to as NOAEL. The European Commission (EC) requested EFSA to review the information regarding the toxicity of fumonisins for pigs, poultry and horses and to revise, if necessary, the established NOAELs. The EFSA CONTAM Panel considered that the term reference point (RP) for adverse animal health effects better reflects the uncertainties in the available studies. New evidence which had become available since the previous opinion allowed to revise an RP for adverse animal health effects for poultry from 20 mg/kg to 1 mg/kg feed (based on a LOAEL of 2.5 mg/kg feed for reduced intestinal crypt depth) and for horses from 8.8 to 1.0 mg/kg feed (based on case studies on equine leukoencephalomalacia (ELEM)). For pigs, the previously established NOAEL was confirmed as no further studies suitable for deriving an RP for adverse animal health effects could be identified. Based on exposure estimates performed in the previous opinion, the risk of adverse health effects of feeds containing FB1-3 was considered a concern for poultry, when taking into account the RP of 1 mg/kg feed for intestinal effects. For horses and other solipeds, the risk is considered low, although a large uncertainty associated with exposure was identified. The same conclusions apply to the sum of FB1-3 and their hidden forms.

Efficacy of Fumonisin Esterase in Piglets as Animal Model for Fumonisin Detoxification in Humans: Pilot Study Comparing Intraoral to Intragastric Administration

Fumonisins, a group of highly prevalent and toxic mycotoxins, are suspected to be causal agents of several diseases in animals and humans. In the animal feed industry, fumonisin esterase is used as feed additive to prevent mycotoxicosis caused by fumonisins. In humans, a popular dosage form for dietary supplements, with high patient acceptance for oral intake, is capsule ingestion. Thus, fumonisin esterase provided in a capsule could be an effective strategy against fumonisin intoxication in humans. To determine the efficacy of fumonisin esterase through capsule ingestion, two modes of application were compared using piglets in a small-scale preliminary study. The enzyme was administered intraorally (in-feed analogue) or intragastrically (capsule analogue), in combination with fumonisin B1 (FB1). Biomarkers for FB1 exposure; namely FB1, hydrolysed FB1 (HFB1) and partially hydrolysed forms (pHFB1a and pHFB1b), were measured both in serum and faeces using a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method, and toxicokinetic parameters were calculated. Additionally, the serum sphinganine/sphingosine (Sa/So) ratio, a biomarker of effect, was determined using LC-MS/MS. A significantly higher Sa/So ratio was shown in the placebo group compared to both esterase treatments, demonstrating the efficacy of the esterase. Moreover, a significant decrease in serum FB1 area under the concentration-time curve (AUC) and an increase of faecal HFB1 AUC were observed after intraoral esterase administration. However, these effects were not observed with statistical significance after intragastric esterase administration with the current sample size.

LC-MS/MS Analysis of Fumonisin B1, B2, B3, and Their Hydrolyzed Metabolites in Broiler Chicken Feed and Excreta

An accurate, reliable, and specific method was developed for the quantitative determination of fumonisins B1, B2, B3, and their hydrolyzed metabolites, HFB1, HFB2, and HFB3, in broiler chicken feed and excreta using ultra-performance liquid chromatography combined with tandem mass spectrometry (UPLC-MS/MS). The samples were extracted and diluted for the determination of parent fumonisins. Another portion of the extracted samples was alkaline-hydrolyzed and cleaned using a strong anionic exchange adsorbent (MAX) for the determination of hydrolyzed fumonisins. Chromatographic separation was performed on a CORTECS C18 column (2.1 mm × 100 mm, 1.6 μm) using 0.2% formic acid aqueous solution and methanol with 0.2% formic acid as the mobile phase under gradient elution. The six fumonisins, FB1, FB2, FB3, HFB1, HFB2, and HFB3, were analyzed by tandem mass spectrometry using multiple-reaction monitoring (MRM) mode. The six fumonisins showed good linearity, with relative coefficients of r > 0.99. The limits of quantitation (LOQs) were 160 μg/kg. At the low, medium, and high spiked levels, the recovery of fumonisins in chicken feed and excreta ranged from 82.6 to 115.8%, with a precision (RSD) of 3.9–18.9%. This method was successfully applied to investigate the migration and transformation of fumonisins in broiler chickens.

Effects of Deoxynivalenol and Fumonisins on Broiler Gut Cytoprotective Capacity

Mycotoxins are a crucial problem for poultry production worldwide. Two of the most frequently found mycotoxins in feedstuffs are deoxynivalenol (DON) and fumonisins (FUM) which adversely affect gut health and poultry performance. The current knowledge on DON and FUM effects on broiler responses relevant for gut detoxification, antioxidant capacity, and health is still unclear. The aim of this study was to assess a range of selected molecular intestinal biomarkers for their responsiveness to the maximum allowable European Union dietary levels for DON (5 mg/kg) and FUM (20 mg/kg) in broilers. For the experimental purpose, a challenge diet was formulated, and biomarkers relevant for detoxification, antioxidant response, stress, inflammation, and integrity were profiled across the broiler intestine. The results reveal that DON significantly (p < 0.05) induced aryl hydrocarbon receptor (AhR) and cytochrome P450 enzyme (CYP) expression mainly at the duodenum. Moreover, DON and FUM had specific significant (p < 0.05) effects on the antioxidant response, stress, inflammation, and integrity depending on the intestinal segment. Consequently, broiler molecular responses to DON and FUM assessed via a powerful palette of biomarkers were shown to be mycotoxin and intestinal site specific. The study findings could be highly relevant for assessing various dietary bioactive components for protection against mycotoxins.

Metabolism of Zearalenone in the Rumen of Dairy Cows with and without Application of a Zearalenone-Degrading Enzyme

The mycotoxin zearalenone (ZEN) is a frequent contaminant of animal feed and is well known for its estrogenic effects in animals. Cattle are considered less sensitive to ZEN than pigs. However, ZEN has previously been shown to be converted to the highly estrogenic metabolite α-zearalenol (α-ZEL) in rumen fluid in vitro. Here, we investigate the metabolism of ZEN in the reticulorumen of dairy cows. To this end, rumen-fistulated non-lactating Holstein Friesian cows (n = 4) received a one-time oral dose of ZEN (5 mg ZEN in 500 g concentrate feed) and the concentrations of ZEN and ZEN metabolites were measured in free rumen liquid from three reticulorumen locations (reticulum, ventral sac and dorsal mat layer) during a 34-h period. In all three locations, α-ZEL was the predominant ZEN metabolite and β-zearalenol (β-ZEL) was detected in lower concentrations. ZEN, α-ZEL and β-ZEL were eliminated from the ventral sac and reticulum within 34 h, yet low concentrations of ZEN and α-ZEL were still detected in the dorsal mat 34 h after ZEN administration. In a second step, we investigated the efficacy of the enzyme zearalenone hydrolase ZenA (EC 3.1.1.-, commercial name ZENzyme^®, BIOMIN Holding GmbH, Getzersdorf, Austria) to degrade ZEN to the non-estrogenic metabolite hydrolyzed zearalenone (HZEN) in the reticulorumen in vitro and in vivo. ZenA showed a high ZEN-degrading activity in rumen fluid in vitro. When ZenA was added to ZEN-contaminated concentrate fed to rumen-fistulated cows (n = 4), concentrations of ZEN, α-ZEL and β-ZEL were significantly reduced in all three reticulorumen compartments compared to administration of ZEN-contaminated concentrate without ZenA. Upon ZenA administration, degradation products HZEN and decarboxylated HZEN were detected in the reticulorumen. In conclusion, endogenous metabolization of ZEN in the reticulorumen increases its estrogenic potency due to the formation of α-ZEL. Our results suggest that application of zearalenone hydrolase ZenA as a feed additive may be a promising strategy to counteract estrogenic effects of ZEN in cattle.

Fumonisin B1: Mechanisms of toxicity and biological detoxification progress in animals

Fumonisin B1 (FB₁) is a toxic secondary metabolite produced by the Fusarium molds that can contaminate food and feed. It has been found that FB₁ can cause systemic toxicity, including neurotoxicity, hepatotoxicity, nephrotoxicity and mammalian cytotoxicity. This review addresses the toxicity studies carried out on FB₁ and outlines the probable mechanisms underlying its immunotoxicity, reproductive toxicity, joint toxicity, apoptosis, and autophagy. In the present work, the research progress of FB₁ detoxification in recent years is reviewed, which provides reference for controlling and reducing the toxicity of FB₁.

Fumonisins and zearalenone fed at low levels can persist several days in the liver of turkeys and broiler chickens after exposure to the contaminated diet was stopped

Previous studies using zearalenone (ZEN) and fumonisins (FB) revealed alpha-zearalanol (α-ZOL) and FB1 in the liver of turkeys and chickens with no sign of toxicity. The aim of the present study was to determine whether contamination persists after distribution of a mycotoxin-free diet for several days. Turkeys and broilers were fed for 14 days with a diet containing respectively, 7.5 and 0.6 mg/kg of FB and ZEN, then fed for 0, 2 or 4 days with a mycotoxin-free diet. FB1 and total α-ZOL were the most abundant metabolites found, and their concentration decreased with time. The decrease was linear for FB1 (P < 0.001) and exponential for α-ZOL. Mean concentrations of FB1 on days 0, 2, and 4 were respectively, 4.9, 4, and 2.9 ng/g in turkeys, and respectively, 5, 2.3, and 1.3 ng/g in chickens. The decrease in concentration of FB1 with time was modeled by linear regression (P < 0.001). Mean concentrations of α-ZOL on days 0, 2 and 4, were respectively, 4.8, 0.8, and 0.5 ng/g in turkeys, whereas α-ZOL was only quantified in chickens on day 0 at 0.3 ng/g. A strong correlation was found between α-ZOL and β-zearalenol (P < 0.001).

Mycotoxin and Gut Microbiota Interactions

The interactions between mycotoxins and gut microbiota were discovered early in animals and explained part of the differences in susceptibility to mycotoxins among species. Isolation of microbes present in the gut responsible for biotransformation of mycotoxins into less toxic metabolites and for binding mycotoxins led to the development of probiotics, enzymes, and cell extracts that are used to prevent mycotoxin toxicity in animals. More recently, bioactivation of mycotoxins into toxic compounds, notably through the hydrolysis of masked mycotoxins, revealed that the health benefits of the effect of the gut microbiota on mycotoxins can vary strongly depending on the mycotoxin and the microbe concerned. Interactions between mycotoxins and gut microbiota can also be observed through the effect of mycotoxins on the gut microbiota. Changes of gut microbiota secondary to mycotoxin exposure may be the consequence of the antimicrobial properties of mycotoxins or the toxic effect of mycotoxins on epithelial and immune cells in the gut, and liberation of antimicrobial peptides by these cells. Whatever the mechanism involved, exposure to mycotoxins leads to changes in the gut microbiota composition at the phylum, genus, and species level. These changes can lead to disruption of the gut barrier function and bacterial translocation. Changes in the gut microbiota composition can also modulate the toxicity of toxic compounds, such as bacterial toxins and of mycotoxins themselves. A last consequence for health of the change in the gut microbiota secondary to exposure to mycotoxins is suspected through variations observed in the amount and composition of the volatile fatty acids and sphingolipids that are normally present in the digesta, and that can contribute to the occurrence of chronic diseases in human. The purpose of this work is to review what is known about mycotoxin and gut microbiota interactions, the mechanisms involved in these interactions, and their practical application, and to identify knowledge gaps and future research needs.

Identification and Characterization of an Aspergillus niger Amine Oxidase that Detoxifies Intact Fumonisins

Fumonisin contamination of maize damaged by Fusarium verticillioides and related species is a major problem when it is grown under warm and dry conditions. Consumption of fumonisin contaminated food and feed is harmful to both humans and livestock. Novel tools for reducing or eliminating fumonisin toxicity may be useful to the agri-feed sector to deal with this worldwide problem. Enzymes capable of catabolizing fumonisins have been identified from microorganisms that utilize fumonisins as an energy source. However, fumonisin detoxifying enzymes produced by the very species that biosynthesize the toxin have yet to be reported. Here we describe the identification and characterization of a novel amine oxidase synthesized by the fumonisin-producing fungus Aspergillus niger. We have recombinantly expressed this A. niger enzyme in E. coli and demonstrated its ability to oxidatively deaminate intact fumonisins without requiring exogenous cofactors. This enzyme, termed AnFAO (A. niger fumonisin amine oxidase), displays robust fumonisin deamination activity across a broad range of conditions, has a high native melting temperature, and can be purified to >95% homogeneity at high yield in a one-step enrichment. AnFAO is a promising tool to remediate fumonisin-contaminated feed including maize destined for ethanol production.

The fate of mycotoxins during secondary food processing of maize for human consumption

Mycotoxins are naturally occurring fungal metabolites that are associated with health hazards and are widespread in cereals including maize. The most common mycotoxins in maize that occur at relatively high levels are fumonisins (FBs), zearalenone, and aflatoxins; furthermore, other mycotoxins such as deoxynivalenol and ochratoxin A are frequently present in maize. For these toxins, maximum levels are laid down in the European Union (EU) for maize raw materials and maize-based foods. The current review article gives a comprehensive overview on the different mycotoxins (including mycotoxins not regulated by EU law) and their fate during secondary processing of maize, based on the data published in the scientific literature. Furthermore, potential compliance with the EU maximum levels is discussed where appropriate. In general, secondary processing can impact mycotoxins in various ways. Besides changes in mycotoxin levels due to fractionation, dilution, and/or concentration, mycotoxins can be affected in their chemical structure (causing degradation or modification) or be released from or bound to matrix components. In the current review, a special focus is set on the effect on mycotoxins caused by different heat treatments, namely, baking, roasting, frying, (pressure) cooking, and extrusion cooking. Production processes involving multiple heat treatments are exemplified with the cornflakes production. For that, potential compliance with FB maximum levels was assessed. Moreover, effects of fermentation of maize matrices and production of maize germ oil are covered by this review.

A mycotoxin-deactivating feed additive counteracts the adverse effects of regular levels of Fusarium mycotoxins in dairy cows

Little is known about the effects of commonly found levels of Fusarium mycotoxins on the performance, metabolism, and immunity of dairy cattle. We investigated the effects of regular contamination levels, meaning contamination levels that can be commonly detected in dairy feeds, of deoxynivalenol (DON) and fumonisins (FB) in total mixed ration (TMR) on the performance, diet digestibility, milk quality, and plasma liver enzymes in dairy cows. This trial examined 12 lactating Holstein dairy cows using a 3-period × 3-treatment Latin square design. The experimental period was 21 d of mycotoxin exposure followed by 14 d of washout. During treatment periods, cows received one of 3 diets: (1) CTR (control) diet of TMR contaminated with 340.5 µg of DON/kg of dry matter (DM) and 127.9 µg FB/kg of DM; (2) MTX diet of TMR contaminated with Fusarium mycotoxins at levels higher than CTR but below US and European Union guidelines (i.e., 733.0 µg of DON/kg of DM and 994.4 µg of FB/kg of DM); or (3) MDP diet, which was MTX diet supplemented with a mycotoxin deactivator product (i.e., 897.3 µg of DON/kg of DM and 1,247.1 µg of FB/kg of DM; Mycofix, 35 g/animal per day). During washout, all animals were fed the same CTR diet. Body weight, body condition score, DM intake, dietary nutrient digestibility, milk production, milk composition and rennet coagulation properties, somatic cell count, blood serum chemistry, hematology, serum immunoglobulin concentrations, and expression of multiple genes in circulating leucocytes were measured. Milk production was significantly greater in the CTR group (37.73 kg/d) than in the MTX (36.39 kg/d) and the MDP (36.55 kg/d) groups. Curd firmness and curd firming time were negatively affected by the MTX diet compared with the other 2 diets. Furthermore, DM and neutral detergent fiber digestibility were lower after the MTX diet than after the CTR diet (67.3 vs. 71.0% and 42.8 vs. 52.3%). The MDP diet had the highest digestibility coefficients for DM (72.4%) and neutral detergent fiber (53.6%) compared with the other 2 diets. The activities of plasma liver transaminases were higher after the MTX diet than after the CTR and MDP diets. Compared with the CTR diet, the MTX diet led to slightly lower expression of genes related to immune and inflammatory functions, indicating that Fusarium mycotoxins had an immunosuppressive effect. Our results indicated that feed contaminated with regular levels of Fusarium mycotoxins adversely affected the performance, milk quality, diet digestibility, metabolic variables, and immunity of dairy cows, and that supplementation with mycotoxin deactivator product counteracted most of these negative effects.

Assessment of ionic homeostasis imbalance and cytochrome P450 system disturbance in mice during fumonisin B1 (FB1) exposure

Fumonisin B1 (FB1) is a mycotoxin frequently found in agricultural commodities, and poses a considerable risk for human and animal health. The aim of this study was to investigate the toxic effect of FB1 in mice intestine. Male Kunming mice (n = 40) were treated with FB1 diet for 42 days. Histopathological and biochemical analyses, including ion concentrations, transcription of ATPase subunits and mRNA expression of cytochrome P450s (CYP450s) analyses were performed on duodenum, cecum and colon of mice. The results revealed that FB1 caused histological alterations, including partial shedding of villous epithelial cells and inflammatory cell infiltration. Furthermore, a significant change in Na⁺, K⁺ and Ca²⁺ in serum, and the mRNA expression of ATPase subunits and CYP450s in intestinal tracts were observed in FB1-exposed mice. Our results suggested that FB1 exposure induce histopathological injury via disrupting CYP isoforms transcription and triggering ion homeostasis imbalance in mice intestinal tracts.

Toxicokinetics of Hydrolyzed Fumonisin B1 after Single Oral or Intravenous Bolus to Broiler Chickens Fed a Control or a Fumonisins-Contaminated Diet

The toxicokinetics (TK) of hydrolyzed fumonisin B₁ (HFB₁) were evaluated in 16 broiler chickens after being fed either a control or a fumonisins-contaminated diet (10.8 mg fumonisin B₁, 3.3 mg B₂ and 1.5 mg B₃/kg feed) for two weeks, followed by a single oral (PO) or intravenous (IV) dose of 1.25 mg/kg bodyweight (BW) of HFB₁. Fumonisin B₁ (FB₁), its partially hydrolyzed metabolites pHFB_1a and pHFB_1b, and fully hydrolyzed metabolite HFB₁, were determined in chicken plasma using a validated ultra-performance liquid chromatography–tandem mass spectrometry method. None of the broiler chicken showed clinical symptoms of fumonisins (FBs) or HFB₁ toxicity during the trial, nor was an aberration in body weight observed between the animals fed the FBs-contaminated diet and those fed the control diet. HFB₁ was shown to follow a two-compartmental pharmacokinetic model with first order elimination in broiler chickens after IV administration. Toxicokinetic parameters of HFB₁ demonstrated a total body clearance of 16.39 L/kg·h and an intercompartmental flow of 8.34 L/kg·h. Low levels of FB₁ and traces of pHFB_1b were found in plasma of chickens fed the FBs-contaminated diet. Due to plasma concentrations being under the limit of quantification (LOQ) after oral administration of HFB₁, no toxicokinetic modelling could be performed in broiler chickens after oral administration of HFB₁. Moreover, no phase II metabolites, nor N-acyl-metabolites of HFB₁ could be detected in this study.

An In Silico Target Fishing Approach to Identify Novel Ochratoxin A Hydrolyzing Enzyme

Ochratoxin A (OTA), a mycotoxin that is of utmost concern in food and feed safety, is produced by fungal species that mainly belong to the Aspergillus and Penicillium genera. The development of mitigation strategies to reduce OTA content along the supply chains is key to ensuring safer production of food and feed. Enzyme-based strategies are among the most promising methods due to their specificity, efficacy, and multi-situ applicability. In particular, some enzymes are already known for hydrolyzing OTA into ochratoxin alpha (OTα) and phenylalanine (Phe), eventually resulting in detoxification action. Therefore, the discovery of novel OTA hydrolyzing enzymes, along with the advancement of an innovative approach for their identification, could provide a broader basis to develop more effective mitigating strategies in the future. In the present study, a hybrid in silico/in vitro workflow coupling virtual screening with enzymatic assays was applied in order to identify novel OTA hydrolyzing enzymes. Among the various hits, porcine carboxypeptidase B was identified for the first time as an effective OTA hydrolyzing enzyme. The successful experimental endorsement of findings of the workflow confirms that the presented strategy is suitable for identifying novel OTA hydrolyzing enzymes, and it might be relevant for the discovery of other mycotoxin- mitigating enzymes.

Fumonisin B1, B2 and B3 in Muscle and Liver of Broiler Chickens and Turkey Poults Fed with Diets Containing Fusariotoxins at the EU Maximum Tolerable Level

Although provisional maximum tolerable daily intake and recommended guidelines have been established for fumonisins (FB) in food, few data are available concerning levels of FB in edible animal tissues. Such data are of particular interest in avian species that can tolerate relatively high levels of fumonisins in their feed. Also, even if multiple contamination of animal feed by toxins produced by Fusarium is very frequent, little is known about the consequences of multiple contamination for FB levels in tissues. The aim of this study was to analyze the concentrations of FB in the muscle and liver of chickens and turkeys fed with FB alone and with FB combined with deoxynivalenol (DON), and with zearalenone (ZEN). Experimental diets were formulated by incorporating ground cultured toxigenic Fusarium strains in corn-soybean based feeds. Control diets were free of mycotoxins, FB diets contained 20 mg FB1+FB2/kg, and FBDONZEN diets contained 20, 5, and 0.5 mg/kg of FB1+FB2, DON, and ZEN, respectively. Animals were reared in individual cages with free access to water and feed. The feed was distributed to male Ross chickens from the 1st to the 35th day of age and to male Grade Maker turkeys from the 55th to the 70th day of age. On the last day of the study, the birds were starved for eight hours, killed, and autopsied for tissues sampling. No sign of toxicity was observed. A UHPLC-MS/MS method with isotopic dilution and immunoaffinity clean-up of samples has been developed for analysis of FB in muscle (n = 8 per diet) and liver (n = 8 per diet). Only traces of FB that were below the LOQ of 0.25 µg/kg were found in most of the samples of animals fed with the control diets. Mean concentrations of FB1, FB2, and FB3 in muscle were 17.5, 3.39, and 1.26 µg/kg, respectively, in chickens, and 5.77, 1.52, and 0.54 µg/kg in turkeys, respectively. In the liver, the respective FB1, FB2, and FB3 concentrations were 44.7, 2.61, and 0.79 µg/kg in chickens, and 41.47, 4.23, and 1.41 µg/kg, in turkeys. Cumulated level of FB1+FB2+FB3 in the highly contaminated samples were above 60 and 100 µg/kg in muscle and liver, respectively. The concentrations of FB in the tissues of animals fed the FBDONZEN diet did not greatly differ from the concentrations measured in animals fed the diet containing only FB.

Detoxification of the Fumonisin Mycotoxins in Maize: An Enzymatic Approach

Enzymatic detoxification has become a promising approach for control of mycotoxins postharvest in grains through modification of chemical structures determining their toxicity. In the present study fumonisin esterase FumD (EC 3.1.1.87) (FUMzyme^®; BIOMIN, Tulln, Austria), hydrolysing fumonisin (FB) mycotoxins by de-esterification, was utilised to develop an enzymatic reduction method in a maize kernel enzyme incubation mixture. Efficacy of the FumD FB reduction method in “low” and “high” FB contaminated home-grown maize was compared by monitoring FB₁ hydrolysis to the hydrolysed FB₁ (HFB₁) product utilising a validated LC-MS/MS analytical method. The method was further evaluated in terms of enzyme activity and treatment duration by assessing enzyme kinetic parameters and the relative distribution of HFB₁ between maize kernels and the residual aqueous environment. FumD treatments resulted in significant reduction (≥80%) in “low” (≥1000 U/L, p < 0.05) and “high” (100 U/L, p < 0.05; ≥1000 U/L, p < 0.0001) FB contaminated maize after 1 h respectively, with an approximate 1:1 µmol conversion ratio of FB₁ into the formation of HFB₁. Enzyme kinetic parameters indicated that, depending on the activity of FumD utilised, a significantly (p < 0.05) higher FB₁ conversion rate was noticed in “high” FB contaminated maize. The FumD FB reduction method in maize could find application in commercial maize-based practices as well as in communities utilising home-grown maize as a main dietary staple and known to be exposed above the tolerable daily intake levels.

Oral and Intravenous Fumonisin Exposure in Pigs-A Single-Dose Treatment Experiment Evaluating Toxicokinetics and Detoxification

We examined the toxicokinetics of fumonisin B₁ (FB1) and its main metabolites after single dose application intravenously (iv) of 139 nmol FB1 or hydrolyzed FB1 (HFB1)/kg bodyweight (BW) in barrows (BW: 34.4 kg ± 2.7 kg), as well as the toxicokinetics of FB1, FB2, FB3 and FB1 bioavailability from oral exposure (3425 nmol FB1/kg BW, on top of ration). Additionally, detoxification efficacy of FumD (240 U/kg feed; 3321 nmol FB1/kg BW), a fumonisin esterase, was examined for oral fumonisin application. Urine and feces were collected quantitatively and serum samples were taken over a period of 120 h. Serum toxicokinetics of FB1iv showed a short distribution half-life of 6 min followed by a longer elimination half-life of 36 min. After HFB1iv administration, serum clearance was three times higher compared to FB1iv group (5.6 and 1.8 L/kg/h respectively) which together with a 5-times higher volume of distribution indicates that HFB1 is more rapidly cleared from systemic circulation but distributed more extensively into the extravasal space than FB1. The bioavailability of FB1 in orally exposed pigs was 5.2% (incl. metabolites). Moreover, we found a significant reduction of FB1 bioavailability by 90% caused by the action of fumonisin esterase in the gastrointestinal tract, clearly demonstrating the efficacy of FumD.