Natural inhibitors: A sustainable way to combat aflatoxins

Chemical profile changes in Peanut seeds infected with aspergillus flavus via widely targeted metabolomics

Peanut seeds are enriched with protein and fatty acids, making them susceptible to infection by Aspergillus flavus (A. flavus). The infected seeds are harmful to human health due to the aflatoxin contamination. Despite ongoing research, a comprehensive understanding of the metabolite variations in peanut seeds during A. flavus infection remains elusive. In this study, we established a detailed endogenous chemical profile consisting of 1462 metabolites in shelled peanut seeds, identified 895 and 671 differentially expressed metabolites (DEMs) on the 3rd and 6th days post-infection by A. flavus, respectively. Among these, 425 DEMs were common to both profiles, with the majority of co-expressed DEMs displaying an up-regulated expression pattern in response to A. flavus infection. Further metabolites interaction analysis indicated that phenolic acids significantly correlated with A. flavus infection. Specifically, five metabolites classified as phenolic acids demonstrated the ability to repress A. flavus growth in vitro. The anti-infection properties of peanut phenolic acids were confirmed by their higher content in resistant peanut varieties. Overall, our study elucidates the chemical profile of endogenous metabolite variations in A. flavus infected peanut seeds, demonstrating that elevated phenolic acid content can be employed as a biomarker for identifying peanut varieties resistant to A. flavus infection.

Tianjihuang compound alleviates aflatoxin B1-induced hepatic steatosis and fibrosis by targeting PPARα-TGF-β pathway in ducklings

Aflatoxin B1 (AFB1), a potent mycotoxin, poses a significant threat to the poultry industry, particularly affecting the health and growth of ducklings. The present study aimed to investigate the therapeutic effects and mechanisms of the Tianjihuang compound (HRS), a traditional Chinese medicine formulation, on AFB1-induced chronic toxicity in ducklings. Firstly, 30 ingredients, including neochlorogenic acid, kaempferol 3-alpha-D-galactoside, quercetin, hispidulin, caffeic acid, and myricetin, were identified from HRS with UPLC-MS/MS method. Then, over a 25-day experimental period, a total of 100 one-day-old Sichuan Sheldrakes were randomly divided into five groups: control, AFB1 model, and HRS high (4 g/kg), medium (2 g/kg), and low dosage (1 g/kg) groups. Results indicated that HRS effectively mitigated the negative impact on the productivity, reduced the levels of liver index, AST, ALT, and AST/ALT in serum, increased the levels of serum TP content, and obviously alleviated inflammatory cell infiltration, liver fibrosis, and liver steatosis induced by AFB1. Additionally, HRS enhanced the levels of GST, CAT, and T-AOC, and decreased the levels of MDA and AFB1-DNA, thereby alleviating oxidative stress and AFB1-DNA generation caused by AFB1. Transcriptome analysis revealed that HRS may improve liver injury in AFB1-chronically poisoned ducklings by regulating the ECM receptor interaction, fatty acid metabolism, cell adhesion molecules, TGF-β signaling pathway, and PPAR signaling pathway. Further RT-qPCR analysis revealed that HRS might downregulate the expression of ASCL4 gene by promoting the activation of PPARα, thereby inhibiting the activation of the TGF-β signaling pathway and improving liver steatosis and fibrosis caused by AFB1 in ducklings. In conclusion, the HRS exhibits hepatoprotective effects against AFB1-induced chronic toxicity in ducklings by restoring liver function, enhancing antioxidant capacity, and its mechanism of damage resistance may be related to the improvement of liver steatosis and fibrosis in ducklings by inhibiting the PPARα-TGF-β signaling pathway.

Mycotoxin management: exploring natural solutions for mycotoxin prevention and detoxification in food and feed

Mycotoxins, secondary metabolites produced by various fungi, pose a significant threat to food and feed safety worldwide due to their toxic effects on human and animal health. Traditional methods of mycotoxin management often involve chemical treatments, which may raise concerns about residual toxicity and environmental impact. In recent years, there has been growing interest in exploring natural alternatives for preventing mycotoxin contamination and detoxification. This review provides an overview of the current research on the use of natural products for mitigating mycotoxin risks in food and feed. It encompasses a wide range of natural sources, including plant-derived compounds, microbial agents, and enzymatic control. The mechanisms underlying the efficacy of these natural products in inhibiting mycotoxin synthesis, adsorbing mycotoxins, or enhancing detoxification processes are discussed. Challenges and future directions in the development and application of natural products for mycotoxin management are also addressed. Overall, this review highlights the promising role of natural products as sustainable and eco-friendly alternatives for combating mycotoxin contamination in the food and feed supply chain.

Identification and Characterization of Peanut Seed Coat Secondary Metabolites Inhibiting Aspergillus flavus Growth and Reducing Aflatoxin Contamination

The peanut seed coat acts as a physical and biochemical barrier against Aspergillus flavus infection; however, the nature of the inhibitory chemicals in the peanut seed coat in general is not known. This study identified and characterized peanut seed coat metabolites that inhibit A. flavus growth and aflatoxin contamination. Selected peanut accessions grown under well-watered and water-deficit conditions were assayed for A. flavus resistance, and seed coats were metabolically profiled using liquid chromatography mass spectrometry. Kyoto Encyclopedia of Genes and Genome phenylpropanoid pathway reference analysis resulted in the identification of several seed coat metabolic compounds, and ten selected metabolites were tested for inhibition of A. flavus growth and aflatoxin contamination. Radial growth bioassay demonstrated that 2,5-dihydroxybenzaldehyde inhibited A. flavus growth (98.7%) and reduced the aflatoxin contamination estimate from 994 to 1 μg/kg. Scanning electron micrographs showed distorted hyphae and conidiophores in cultures of 2,5-dihydroxybenzaldehyde-treated A. flavus, indicating its potential use for field application as well as seed coat metabolic engineering.

Dietary Aflatoxin G1 exposure causes an imbalance between pulmonary tissue-resident alveolar macrophages and monocyte-derived macrophages in both mother and offspring mice

Aflatoxin G1 (AFG1) is a mycotoxin commonly found in agricultural products, including dried fruits, meat, and milk products. Oral AFG1 administration induced tumor necrosis factor (TNF)-α-dependent chronic pulmonary inflammation, promoting AFG1-induced damage in alveolar epithelial cell, which is associated with lung adenocarcinoma. Pulmonary macrophages may be divided into tissue-resident alveolar macrophages (TRAMs) and monocyte-derived macrophages (MoMs), which involve in chronic lung inflammation. However, whether these macrophages contribute to AFG1-induced chronic pulmonary inflammation remains unknown. In this study, we found oral AFG1 administration disrupted the balance between TRAMs and MoMs, increasing MoMs infiltration and decreasing the number of TRAMs. AFG1 upregulated TNF-α expression in MoMs, but downregulated sialic acid binding Ig-like lectin F (Siglec-F) expression in TRAMs. Inhibition of TNF-α-dependent inflammation rescued the imbalance between TRAMs and MoMs in AFG1-treated lung tissues. Additionally, AFG1 stimulated MoMs differentiation to the proinflammatory M1 phenotype in vitro. Using a specific in vitro TRAM model, AFG1 downregulated Siglec-F and the M2 phenotypic markers arginase 1 and YM1, and upregulated the M1 phenotypic markers IL-6, iNOS and TNF-α, altering the TRAMs phenotype to the pro-inflammatory M1 phenotype in vitro. Additionally, mouse maternal dietary exposure to AFG1 caused an imbalance in pulmonary macrophages, decreasing TRAMs and increasing MoMs population in offspring, which was associated with proliferative lesions in the alveolar septa. Thus, dietary AFG1 exposure triggered an imbalance in pulmonary macrophages in both mother and offspring mice, and induced pro-inflammatory phenotypic alterations, which contributed to AFG1-induced chronic lung inflammation. These results provide clues to how AFG1-induced immunotoxicity and genotoxicity in humans might be prevented.

Validating the protective role of orange and tangerine peel extracts foramending food safety against microorganisms' contamination using molecular docking

Latest studies indicated that agro-food wastes are considered renewable sources of bioactive compounds. This investigation aimed to utilize natural extracts of citrus peels as antimicrobial and anti-aflatoxigenic agents for food safety. The bioactivity of two citrus peels was assessed by total phenolic, flavonoids, and antioxidant activity. Nanoemulsions were manufactured using high-speed homogenization. The mean particle size of the nanoemulsions ranged from 29.41 to 66.41 nm with a polydispersity index of 0.11-0.16. The zeta potential values ranged from -14.27 to -26.74 mV, indicating stability between 81.44% and 99.26%. The orange peel extract showed the highest contents of total phenolic and flavonoids compared to the other extracts and nanoemulsions (39.54 mg GAE/g and 79.54 mg CE/100 g, respectively), which agreed with its potential antioxidant activity performed by DPPH free radical-scavenging and ABTS assays. Chlorogenic, caffeic, ferulic, and catechin were the dominant phenolic acids in the extracts and nanoemulsions, while quercitrin, rutin, and hesperidin were the most abundant flavonoids. Limonene was the major volatile component in both oils; however, it was reduced dramatically from 92.52% to 76.62% in orange peel oil and from 91.79 to 79.12% in tangerine peel oil. Consistent with the differences in phenolics, flavonoids, and volatiles between orange and tangerine peel extracts, the antibacterial properties of orange extracts had more potential than tangerine ones. Gram-positive bacteria were more affected by all the examined extracts than Gram-negative ones. The antifungal activity of orange extract and nanoemulsion on seven fungal strains from Aspergillus spp had more potential than tangerine extracts. Additionally, using a simulated media, the orange peel extract and its nanoemulsion had a more anti-aflatoxigenic influence. Molecular docking confirmed the high inhibitory action of flavonoids, especially hesperidin, on the polyketide synthase (-9.3 kcal/mol) and cytochrome P450 monooxygenase (-10.1 kcal/mol) key enzymes of the aflatoxin biosynthetic mechanism.

Research advances in the degradation of aflatoxin by lactic acid bacteria

Aflatoxins are toxic secondary metabolites that often contaminate food and animal feed, causing huge economic losses and serious health hazards. Aflatoxin contamination has become a major concern worldwide. Biological methods have been used to reduce aflatoxins in food and feed by inhibiting toxin production and detoxification. Among biological methods, lactic acid bacteria are of significant interest because of their safety, efficiency, and environmental friendliness. This study aimed to review the mechanisms by which lactic acid bacteria degrade aflatoxins and the factors that influence their degradation efficiency, including the action of the lactic acid bacteria themselves (cell wall adsorption) and the antifungal metabolites produced by the lactic acid bacteria. The current applications of lactic acid bacteria to food and feed were also reviewed. This comprehensive analysis provided insight into the binding mechanisms between lactic acid bacteria and aflatoxins, facilitating the practical applications of lactic acid bacteria to food and agriculture.

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

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

Immunosensors for Assay of Toxic Biological Warfare Agents

An immunosensor for the assay of toxic biological warfare agents is a biosensor suitable for detecting hazardous substances such as aflatoxin, botulinum toxin, ricin, Shiga toxin, and others. The application of immunosensors is used in outdoor assays, point-of-care tests, as a spare method for more expensive devices, and even in the laboratory as a standard analytical method. Some immunosensors, such as automated flow-through analyzers or lateral flow tests, have been successfully commercialized as tools for toxins assay, but the research is ongoing. New devices are being developed, and the use of advanced materials and assay techniques make immunosensors highly competitive analytical devices in the field of toxic biological warfare agents assay. This review summarizes facts about current applications and new trends of immunosensors regarding recent papers in this area.