Saccharomyces cerevisiae Cell Wall-Based Adsorbent Reduces Aflatoxin B1 Absorption in Rats

Mycotoxins are naturally occurring toxins that can affect livestock health and performance upon consumption of contaminated feedstuffs. To mitigate the negative effects of mycotoxins, sequestering agents, adsorbents, or binders can be included to feed to interact with toxins, aiding their passage through the gastrointestinal tract (GI) and reducing their bioavailability. The parietal cell wall components of Saccharomyces cerevisiae have been found to interact in vitro with mycotoxins, such as, but not limited to, aflatoxin B1 (AFB1), and to improve animal performance when added to contaminated diets in vivo. The present study aimed to examine the pharmacokinetics of the absorption of radiolabeled AFB1 in rats in the presence of a yeast cell wall-based adsorbent (YCW) compared with that in the presence of the clay-based binder hydrated sodium calcium aluminosilicate (HSCAS). The results of the initial pharmacokinetic analysis showed that the absorption process across the GI tract was relatively slow, occurring over a matter of hours rather than minutes. The inclusion of mycotoxin binders increased the recovery of radiolabeled AFB1 in the small intestine, cecum, and colon at 5 and 10 h, revealing that they prevented AFB1 absorption compared with a control diet. Additionally, the accumulation of radiolabeled AFB1 was more significant in the blood plasma, kidney, and liver of animals fed the control diet, again showing the ability of the binders to reduce the assimilation of AFB1 into the body. The results showed the potential of YCW in reducing the absorption of AFB1 in vivo, and in protecting against the damaging effects of AFB1 contamination.

Research progress on the protection and detoxification of phytochemicals against aflatoxin B1-Induced liver toxicity

Aflatoxin B₁ (AFB₁) is a potent hepatotoxic toxin, which can cause hepatitis, cirrhosis, and liver immunological damage. It has been involved in the etiology of human hepatocellular carcinoma. AFB₁ can cause oxidative stress in the body's metabolism process, and then cause cytotoxicity, such as apoptosis and DNA damage. Scientific research has discovered that phytochemicals can induce the detoxification pathway of AFB₁ through its biotransformation, thereby reducing the damage of AFB₁ to the human body. In clinical treatment, certain phytochemicals have been effectively used in the treatment of liver injury due to the advantages of multiple targets, multiple pathways, low toxicity and side effects. Therefore, the article summarizes the toxic mechanism of AFB₁-induced hepatoxicity, and the related research progress of phytochemicals for preventing and treating its cytotoxicity and genotoxicity. We also look forward to the existing problems and application prospects of phytochemicals in the pharmaceutical industry, in order to provide theoretical reference for the prevention and treatment of AFB₁ poisoning in future research work.

Mycotoxin-contaminated diets and an adsorbent affect the performance of Nellore bulls finished in feedlots

Mycotoxins are present in almost all feedstuffs used in animal nutrition but are often ignored in beef cattle systems, even though they can affect animal performance. The objective of this study was to evaluate the effects of mycotoxins and a mycotoxin adsorbent (ADS) on performance of Nellore cattle finished in a feedlot. One hundred Nellore cattle (430 ± 13 kg) were used in a randomized complete block design with a 2 × 2 factorial arrangement of treatments. The factors consisted of two diets with either natural contamination (NC) or exogenous contamination (EC) and the presence (1 g/kg of DM; ADS) or absence of a mycotoxin adsorbent. The NC and EC diets had the following contaminations, respectively: 0.00 and 10.0 µg/kg aflatoxins, 5114 and 5754 µg/kg fumonisins, 0.00 and 42.1 µg/kg trichothecenes B, 0.00 and 22.1 µg/kg trichothecenes A and 42.9 and 42.9 µg/kg fusaric acid. At the beginning of the experiment, all animals were weighed, and four randomly selected animals were slaughtered to evaluate the initial carcass weight. After 97 days of treatment, all animals were weighed and slaughtered. There was no interaction among factors for the DM intake (DMI; P = 0.92); however, there was a tendency for the EC diets to decrease the DMI by 650 g/day compared to animals fed NC diets (P = 0.09). There was a trend for interaction among factors (P = 0.08) for the average daily gain (ADG), where the greatest ADG was observed for cattle fed the NC diet (1.77 kg), and the lowest was observed for those fed the EC diet (1.51 kg). The NC + ADS and EC + ADS treatments presented intermediate values for ADG. The animals fed the NC diet had a greater final BW (596 kg) than animals fed the EC treatment (582 kg; P = 0.04). There was a tendency for interaction among factors for carcass gain (P = 0.08). Similarly to ADG, the highest carcass gain was observed for animals fed the NC diet (1.20 kg), and the lowest was observed for those fed the EC diet (1.05 kg). The NC + ADS and EC + ADS treatments presented intermediate values. The natural contamination groups had greater carcass gain than that of the EC groups, and the use of the ADS recovered part of the weight gain in animals fed the EC diet. In conclusion, mycotoxins at the levels evaluated affected the performance of beef cattle, and adsorbents may mitigate their impact.

A Novel Modified Hydrated Sodium Calcium Aluminosilicate (HSCAS) Adsorbent Can Effectively Reduce T-2 Toxin-Induced Toxicity in Growth Performance, Nutrient Digestibility, Serum Biochemistry, and Small Intestinal Morphology in Chicks

The objective of this study was to evaluate the ability of a modified hydrated sodium calcium aluminosilicate (HSCAS) adsorbent to reduce the toxicity of T-2 toxin in broilers. Ninety-six one-day-old male broilers were randomly allocated into four experimental groups with four replicates of six birds each. The four groups, 1–4, received a basal diet (BD), a BD plus 6.0 mg/kg T-2 toxin, a BD plus 6.0 mg/kg T-2 toxin with 0.05% modified HSCAS adsorbent, and a BD plus 0.05% modified HSCAS adsorbent, respectively, for two weeks. Growth performance, nutrient digestibility, serum biochemistry, and small intestinal histopathology were analyzed. Compared to the control group, dietary supplementation of T-2 toxin decreased (p < 0.05) body weight gain, feed intake, and the feed conversion ratio by 11.4–31.8% during the whole experiment. It also decreased (p < 0.05) the apparent metabolic rates of crude protein, calcium, and total phosphorus by 14.9–16.1%. The alterations induced by T-2 toxin were mitigated (p < 0.05) by the supplementation of the modified HSCAS adsorbent. Meanwhile, dietary modified HSCAS adsorbent supplementation prevented (p < 0.05) increased serum aspartate aminotransferase by T-2 toxin at d 14. It also prevented (p < 0.05) T-2 toxin-induced morphological changes and damage in the duodenum, jejunum, and ileum of broilers. However, dietary supplementation of the modified HSCAS adsorbent alone did not affect (p > 0.05) any of these variables. In conclusion, these findings indicate that the modified HSCAS adsorbent could be used against T-2 toxin-induced toxicity in growth performance, nutrient digestibility, and hepatic and small intestinal injuries in chicks.

Antioxidant agents against trichothecenes: new hints for oxidative stress treatment

Trichothecenes are a group of mycotoxins mainly produced by fungi of genus Fusarium. Due to high toxicity and widespread dissemination, T-2 toxin and deoxynivalenol (DON) are considered to be the most important compounds of this class. Trichothecenes generate free radicals, including reactive oxygen species (ROS), which induce lipid peroxidation, decrease levels of antioxidant enzymes, and ultimately lead to apoptosis. Consequently, oxidative stress is an active area of research on the toxic mechanisms of trichothecenes, and identification of antioxidant agents that could be used against trichothecenes is crucial for human health. Numerous natural compounds have been analyzed and have shown to function very effectively as antioxidants against trichothecenes. In this review, we summarize the molecular mechanisms underlying oxidative stress induced by these compounds, and discuss current knowledge regarding such antioxidant agents as vitamins, quercetin, selenium, glucomannan, nucleotides, antimicrobial peptides, bacteria, polyunsaturated fatty acids, oligosaccharides, and plant extracts. These products inhibit trichothecene-induced oxidative stress by (1) inhibiting ROS generation and induced DNA damage and lipid peroxidation; (2) increasing antioxidant enzyme activity; (3) blocking the MAPK and NF-κB signaling pathways; (4) inhibiting caspase activity and apoptosis; (5) protecting mitochondria; and (6) regulating anti-inflammatory actions. Finally, we summarize some decontamination methods, including bacterial and yeast biotransformation and degradation, as well as mycotoxin-binding agents. This review provides a comprehensive overview of antioxidant agents against trichothecenes and casts new light on the attenuation of oxidative stress.

Grape Pomace, an Agricultural Byproduct Reducing Mycotoxin Absorption: In Vivo Assessment in Pig Using Urinary Biomarkers

The efficacy of four agricultural byproducts (ABPs) and two commercial binders (CBs) to reduce the gastrointestinal absorption of a mixture of mycotoxins was tested in piglets using urinary mycotoxin biomarkers as indicator of the absorbed mycotoxins. Twenty-eight piglets were administered a bolus contaminated with the mycotoxin mixture containing or not ABP or CB. Twenty-four hour urine was collected and analyzed for mycotoxin biomarkers by using a multiantibody immunoaffinity-based LC-MS/MS method. Each bolus contained 769 μg of fumonisin B1 (FB1), 275 μg of deoxynivalenol (DON), 29 μg of zearalenone (ZEN), 6.5 μg of aflatoxin B1 (AFB1) and 6.6 μg of ochratoxin A (OTA) corresponding to 2.2, 0.8, 0.08, 0.02, and 0.02 μg/g in the daily diet, respectively. The percentage of ABP in each bolus was 50%, whereas for the two CBs the percentages were 5.2 and 17%, corresponding to 2.8, 0.3, and 0.9% in the daily diet, respectively. The reduction of mycotoxin absorption was up to 69 and 54% for ABPs and CBs, respectively. White grape pomace of Malvasia was the most effective material as it reduced significantly (p < 0.05) urinary mycotoxin biomarker of AFB1 (67%) and ZEN (69%), whereas reductions statistically not significant were observed for FB1 (57%), DON (40%), and OTA (27%). This study demonstrates that grape pomace reduces the gastrointestinal absorption of mycotoxins. This agricultural byproduct can be considered an alternative to commercial products and used in the feed industries as an effective, cheap, and natural binder for multiple mycotoxins.

Mycotoxins that affect the North American agri-food sector: state of the art and directions for the future

This paper summarises workshop discussions at the 5th international MYCORED meeting in Ottawa, Canada (June 2012) with over 200 participants representing academics, government and industry scientists, government officials and farming organisations (present in roughly equal proportions) from 27 countries. Workshops centred on how mycotoxins in food and feed affect value chains and trade in the region covered by the North American Free Trade Agreement. Crops are contaminated by one or more of five important mycotoxins in parts of Canada and the United States every year, and when contaminated food and feed are consumed in amounts above tolerable limits, human and animal health are at risk. Economic loss from such contamination includes reduced crop yield, grain quality, animal productivity and loss of domestic and export markets. A systematic effort by grain producers, primary, transfer, and terminal elevators, millers and food and feed processers is required to manage these contaminants along the value chain. Workshops discussed lessons learned from investments in plant genetics, fungal genomics, toxicology, analytical and sampling science, management strategies along the food and feed value chains and methods to ameliorate the effects of toxins in grain on animal production and on reducing the impact of mycotoxins on population health in developing countries. These discussions were used to develop a set of priorities and recommendations.

Validation study on urinary biomarkers of exposure for aflatoxin B1, ochratoxin A, fumonisin B1, deoxynivalenol and zearalenone in piglets

The multi-biomarker approach was used to validate urinary biomarkers in piglets administered boluses contaminated with mixtures of deoxynivalenol (DON), aflatoxin B1 (AFB1), fumonisin B1 (FB1), zearalenone (ZEA) and ochratoxin A (OTA) at different concentrations. Boluses contaminated with mycotoxins were prepared by slurrying and freezedrying feed material fortified with culture extracts of selected toxigenic fungi. Piglets were individually placed in metabolic cages to collect urine before gavage and 24 h post dose. Urine samples were hydrolysed with β-glucuronidase and analysed by a multi-biomarker LC-MS/MS method developed and validated to identify and measure biomarkers of FB1, OTA, DON, ZEA and AFB1. Urinary levels of FB1, OTA, DON + de-epoxy-deoxynivalenol, ZEA + alphazearalenol and aflatoxin M1 were selected as biomarkers of FB1, OTA, DON, ZEA and AFB1, respectively. Mean percentages of dietary mycotoxins excreted as biomarkers in 24 h post dose urine were 36.8% for ZEA, 28.5% for DON, 2.6% FB1, 2.6% for OTA and 2.5% for AFB1. A good correlation was observed between the amount of mycotoxins ingested and the amount of relevant biomarkers excreted in 24 h post dose urine. Linear dose-response correlation coefficients ranged between 0.68 and 0.78 for the tested couples of mycotoxin/biomarker. The good sensitivity of the LC-MS/MS method and the good dose-response correlations observed in this study permitted to validate the selected mycotoxin biomarkers in piglets at dietary levels close to the maximum permitted levels reported in Commission Directive 2003/100/EC for AFB1 and the guidance values reported in Commission Recommendation 2006/576/EC for DON, ZEA, OTA and FB1.