Aflatoxin B1 and zearalenone in soybeans: occurrence and distribution in whole and defective kernels

No toxic effects or interactions between aflatoxin B1 and zearalenone in broiler chickens fed diets at China's regulatory limits

Currently, several countries such as China have established regulatory limits for six major mycotoxins in animal feed. However, these limits are primarily designed for single mycotoxin exposure. Co-contamination with multiple mycotoxins is increasingly common, and simultaneous exposure may lead to additive toxic effects. This study aimed to investigate the effects of individual and combined contamination of aflatoxin B1 (AFB1) and zearalenone (ZEA) at China's regulatory limits on the growth performance, oxidative stress, serum biochemistry, immunity indicators, intestinal morphology, liver and kidney histopathology of broilers by incorporating mycotoxin standards into the feed. A total of 432 one-day-old male AA broilers were randomly assigned to four treatment groups, each consisting of six replicates of 18 birds. The control group received a basic diet, while the experimental groups were supplemented with 10 μg/kg AFB1, 500 μg/kg ZEA, or a combination of both in the basic diet. The experimental period lasted for 35 days. The results revealed no significant differences among the groups in terms of growth performance, oxidative damage markers, serum biochemistry, cytokine levels, intestinal health, or histopathological assessments of the liver and kidneys. Furthermore, no toxic interactions between the two mycotoxins were observed. Taken together, these results suggest that future assessments should take into account the combined toxicological effects of a wider range of mycotoxins to inform the revision and formulation of feed safety standards.

Co-contamination and interactions of multiple mycotoxins and heavy metals in rice, maize, soybeans, and wheat flour marketed in Shanghai City

Mycotoxins and heavy metals extensively contaminate grains and grain products, posing severe health risks. This work implements validated ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and inductively coupled plasma mass spectrometry (ICP-MS) methods to quantify the concentration of 12 mycotoxins and five heavy metals in rice, maize, soybeans, and wheat flour samples marketed in Shanghai. The mixed contamination characteristics were analyzed using correlation cluster analysis and co-contamination index, and the probabilities of all cross combinations of contaminations were analyzed using a self-designed JAVA language program. The results showed that grains and grain products were frequently contaminated with both mycotoxins and heavy metals, mostly with deoxynivalenol (DON), 3-acetyl-deoxynivalenol (3-ADON), 15-acetyl-deoxynivalenol (15-ADON), ochratoxin A (OTA), aflatoxins, fumonisin B1 (FB1), fumonisin B2 (FB2), fumonisin B3 (FB3), arsenic (As), chromium (Cr) and cadmium (Cd). All the samples (100 %) were contaminated with two or more contaminants, and 77.3 % of the samples were co-contaminated with more than four contaminants. In cereals and cereal products, the following combinations were closely associated: (FB3 +3-ADON), (FB1 +As), (FB1 +FB2), (DON+FB1), (DON+Cd), (As+Cd), (DON+Cd+As), (FB1 +FB2 +As), and (DON+3-ADON+15-ADON). The results indicated that mycotoxins and heavy metals frequently co-occurred in Shanghai grains and grain products, and they provided primary data for safety assessments, early warnings, and regulatory measures on these contaminants to protect public health.

Thermo-Alkali-Tolerant Recombinant Laccase from Bacillus swezeyi and Its Degradation Potential against Zearalenone and Aflatoxin B1

The enzymatic biodegradation of mycotoxins in food and feed has attracted the most interest in recent years. In this paper, the laccase gene from Bacillus swezeyi was cloned and expressed in Escherichia coli BL 21(D3). The sequence analysis indicated that the gene consisted of 1533 bp. The purified B. swezeyi laccase was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis -12% with an estimated molecular weight of 56.7 kDa. The enzyme is thermo-alkali-tolerant, displaying the optimal degradation of zearalenone (ZEN) and aflatoxin B1 (AFB1) at pH 8 and 9, with incubation temperatures of 55 and 50 °C, respectively, within 24 h. The degradation potentials of the 50 μg of the enzyme against ZEN (5.0 μg/mL) and AFB1 (2.5 μg/mL) were 99.60 and 96.73%, respectively, within 24 h. To the best of our knowledge, this is the first study revealing the recombinant production of laccase from B. swezeyi, its biochemical properties, and potential use in ZEN and AFB1 degradation in vitro and in vivo.

Effect of zearalenone on aflatoxin B1-induced intestinal and ovarian toxicity in pregnant and lactating rats

Aflatoxin B1 (AFB1) and zearalenone (ZEN) cause serious damage to mammals, but few studies have investigated the impacts of these toxins on pregnant and lactating mammals. This study investigated the effects of ZEN on AFB1-induced intestinal and ovarian toxicity in pregnant and lactating rats. Based on the results, AFB1 reduces the digestion, absorption, and antioxidant capacity in the intestine, increases intestinal mucosal permeability, destroys intestinal mechanical barriers, and increases pathogenic bacteria' relative abundances. Simultaneously, ZEN can exacerbate the intestinal injury caused by AFB1. The intestines of the offspring were also damaged, but the damage was less severe than that observed for the dams. While AFB1 activates various signalling pathways in the ovary and affects genes related to endoplasmic reticulum stress, apoptosis, and inflammation, ZEN may exacerbate or antagonize the AFB1 toxicity on gene expression in the ovary through key node genes and abnormally expressed genes. Our study found that mycotoxins can not only directly damage the ovaries and affect gene expression in the ovaries but can also impact ovarian health by disrupting intestinal microbes. Mycotoxins are an important environmental pathogenic factor for intestinal and ovarian disease in pregnancy and lactation mammals.

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.

Aflatoxin B1 in the egg chain: monitoring with specific indirect competitive ELISA in northern Paraná, Brazil

An indirect competitive immunoassay (ic-ELISA) was developed using monoclonal antibody produced by hybridoma AF4, which showed high specificity and reactivity with aflatoxin B1 (AFB1) and aflatoxicol, but low cross-reactivity to other analogs. This low cost reliable method was applied for AFB1 monitoring in the poultry chain of a high agribusiness potential region (northern Paraná state, Brazil). Maize, laying hens feed and egg samples were collected from two poultry farms (with production above 200,000 eggs/day) and evaluated by intralaboratory validated ic-ELISA. The sensitivity of such a validated assay, detecting picogram levels of aflatoxins, demonstrated to be proper for surveying daily ingested cumulative toxins and estimating risks. Additionally, more than 61.00% of positive egg samples ranged between the limit of quantification (LOQ – 0.035 ng/g) and 1.00 ng/g, values commonly not covered by commercial kits. Positive data (>LOQ) occurred in 22 maize (56.40%), 34 feed (85.00%) and 192 (48.00%) egg samples. Mean contamination in maize was 1.51±0.94 ng/g (range 0.11-3.91 ng/g), 1.26±0.96 ng/g in feed (0.10-3.58 ng/g), and 1.01±0.77 ng/g in egg (0.05-3.85 ng/g). No statistical difference was observed between farms (P>0.05) for any of the matrices analysed. However, the difference between median values in maize (0.98 ng/g – Farm A; 1.76 ng/g – Farm B) indicated a higher contamination trend in farm B, possibly due to inadequate local storage. Although there is no limit stipulated for AFB1 contamination in eggs, the levels detected in samples were low and do not represent an immediate risk to animal production or human consumption. Nevertheless, the high frequency of positive maize and feed samples in this field of agribusiness should be highlighted. Sensitive aflatoxin monitoring procedures must be strategically carried out from raw materials to animal derived products, aiming harmless production, which also assures human health.

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.

Is Chickpea a Potential Substitute for Soybean? Phenolic Bioactives and Potential Health Benefits

Legume seeds are rich sources of protein, fiber, and minerals. In addition, their phenolic compounds as secondary metabolites render health benefits beyond basic nutrition. Lowering apolipoprotein B secretion from HepG2 cells and decreasing the level of low-density lipoprotein (LDL)-cholesterol oxidation are mechanisms related to the prevention of cardiovascular diseases (CVD). Likewise, low-level chronic inflammation and related disorders of the immune system are clinical predictors of cardiovascular pathology. Furthermore, DNA-damage signaling and repair are crucial pathways to the etiology of human cancers. Along CVD and cancer, the prevalence of obesity and diabetes is constantly increasing. Screening the ability of polyphenols in inactivating digestive enzymes is a good option in pre-clinical studies. In addition, in vivo studies support the role of polyphenols in the prevention and/or management of diabetes and obesity. Soybean, a well-recognized source of phenolic isoflavones, exerts health benefits by decreasing oxidative stress and inflammation related to the above-mentioned chronic ailments. Similar to soybeans, chickpeas are good sources of nutrients and phenolic compounds, especially isoflavones. This review summarizes the potential of chickpea as a substitute for soybean in terms of health beneficial outcomes. Therefore, this contribution may guide the industry in manufacturing functional foods and/or ingredients by using an undervalued feedstock.

Prevalent Mycotoxins in Animal Feed: Occurrence and Analytical Methods

Today, we have been witnessing a steady tendency in the increase of global demand for maize, wheat, soybeans, and their products due to the steady growth and strengthening of the livestock industry. Thus, animal feed safety has gradually become more important, with mycotoxins representing one of the most significant hazards. Mycotoxins comprise different classes of secondary metabolites of molds. With regard to animal feed, aflatoxins, fumonisins, ochratoxins, trichothecenes, and zearalenone are the more prevalent ones. In this review, several constraints posed by these contaminants at economical and commercial levels will be discussed, along with the legislation established in the European Union to restrict mycotoxins levels in animal feed. In addition, the occurrence of legislated mycotoxins in raw materials and their by-products for the feeds of interest, as well as in the feeds, will be reviewed. Finally, an overview of the different sample pretreatment and detection techniques reported for mycotoxin analysis will be presented, the main weaknesses of current methods will be highlighted.

Opinion on the Hurdles and Potential Health Benefits in Value-Added Use of Plant Food Processing By-Products as Sources of Phenolic Compounds

Plant foods, their products and processing by-products are well recognized as important sources of phenolic compounds. Recent studies in this field have demonstrated that food processing by-products are often richer sources of bioactive compounds as compared with their original feedstock. However, their final application as a source of nutraceuticals and bioactives requires addressing certain hurdles and challenges. This review discusses recent knowledge advances in the use of plant food processing by-products as sources of phenolic compounds with special attention to the role of genetics on the distribution and biosynthesis of plant phenolics, as well as their profiling and screening, potential health benefits, and safety issues. The potentialities in health improvement from food phenolics in animal models and in humans is well substantiated, however, considering the emerging market of plant food by-products as potential sources of phenolic bioactives, more research in humans is deemed necessary.