Fumonisin B1 Research Articles

A preliminary study on the pathology and molecular mechanism of fumonisin B1 nephrotoxicity in young quails.

Fumonisin B1 (FB1) is a widely present mycotoxin that accumulates in biological systems and poses a health risk to animals. However, few studies have reported the molecular mechanism by which FB1 induces nephrotoxicity. The aim of this study was to assess the extent of nephrotoxicity during FB1 exposure and the possible molecular mechanisms behind it. Therefore, 180 young quails were equally divided into two groups. The control group was fed typical quail food, while the experimental group was fed quail food containing 30 mg·kg-1 FB1. Various parameters were assessed, which included histopathological, ultrastructural changes, levels of biochemical parameters, oxidative indicators, inflammatory factors, possible target organelles mitochondrial and endoplasmic reticulum (ER)-related factors, nuclear xenobiotic receptors (NXR) response, and cytochrome P450 system (CYP450s)-related factors in the kidneys on days 14, 28, and 42. The results showed that FB1 can induce oxidative stress through NXR response and disorder of the CYP450s system, leading to mitochondrial dysfunction and ER stress, promoting the expression of inflammatory factors (including IL-1β, IL-6, and IL-8) and causing kidney damage. This study elucidated the possible molecular mechanism by which FB1 induces nephrotoxicity in young quails.

Fabrication of a disposable aptasensing chip for simultaneous label-free detection of four common coexisting mycotoxins

BackgroundCoexisting multiple mycotoxins in food poses severe health risks on humans due to the augmented toxicity. Current multiplex detection methods for mycotoxins have evolved from instrumental analyses to rapid methods based on the specific recognition of antibody/aptamer using different signal transducers. However, nearly all of the reported aptasensors for multiple mycotoxins detection require external labels and can only simultaneous detection of two mycotoxins due to the limitation of distinguishable labels. The tedious labeling process definitely increases the operation complexity and the detection cost. Therefore, rapid method for simultaneous label-free detection of multiple mycotoxins in cereals is urgently needed. ResultsA disposable aptasensing chip was designed for simultaneous label-free detection of fumonisin B1 (FB1), aflatoxin B1 (AFB1), zearalenone (ZEN), and ochratoxin A (OTA) in one sample. Specifically, ITO conductive glass was divided into a rectangle (35 × 25 mm) and then etched by laser to set aside the required four ITO working electrodes (6 mm in diameter) with respective conductive channels. Gold nanoparticles were electrodeposited on the working electrodes to provide abundant anchoring sites for thiolated aptamers immobilization. On this basis, a disposable aptasensing chip for simultaneous label-free detection of four common coexisting mycotoxins has been developed, which used electrochemical impedance spectroscopy as transducer to measure direct biorecognition of the aptamer and corresponding target. This aptasensing chip provided wide linear ranges of 5–1000, 10–250, 10–1250, 10–1500 ng/mL for FB1, AFB1, ZEN, OTA, respectively, with the respective detection limit of 2.47, 3.19, 5.38, 4.87 ng/mL (S/N = 3). Significance and noveltyThis aptasensing chip shows fantastic characteristics of great simplicity and portability, easy operation, and multiple mycotoxins recognition. They are easy to produce on a large scale at low cost and the design concept can be easily expanded to screen a large panel of coexisting targets. This work provides a new avenue for multi-target detection and represents a substantial advance toward food quality and safety monitoring or other fields.

Effects of FB1 and HFB1 on Autonomous Exploratory and Spatial Memory and Learning Abilities in Mice.

Fumonisin B1 (FB1) is a representative form of fumonisin and is widely present in food and feed. Hydrolyzed fumonisin B1 (HFB1) emerges as a breakdown product of FB1, which is accompanied by FB1 alterations. While previous studies have primarily focused on the liver or kidney toxicity of FB1, with limited studies existing on its neurotoxicity and even fewer on the toxicity of HFB1, this study focuses on the neurotoxicity of FB1 and HFB1 exposure in mice investigated by the open field test, Morris water maze test, histopathological analysis, and nontargeted metabolomics. Further, the levels of oxidative stress-related indices, neurotransmitters, and sphingolipids in the brain were measured to analyze their correlation with behavioral outcomes. The results showed that both FB1 (5 mg/kg) and HFB1 (2.8 mg/kg) reduced autonomous exploratory behavior in mice, impaired spatial learning and memory, and caused mild abnormalities in the brain structure. Quantitative analysis further indicated that exposure to FB1 and HFB1 disrupted neurotransmitter homeostasis, exacerbated oxidative stress, and significantly increased the sphinganine/sphingosine (Sa/So) ratio. Moreover, HFB1 exhibited neurotoxic effects similar to those of FB1, emphasizing the need to pay attention to the neurotoxicity effect of HFB1. These findings underscore the importance of understanding the risks and potential neurological damage associated with FB1 and HFB1 exposure, highlighting the necessity for further research in this crucial field.

Mycotoxin reduction and metabolite profiles of ogi produced using traditional fermentation methods

Mycotoxins are widely present in maize, a favourite staple food in sub-Saharan Africa. Food processing methods, like fermentation, have been suggested as potential ways to reduce mycotoxin contamination levels in the grain and, as a result, limit the exposure of crop consumers to the harmful effects of the toxins. The influence of four traditional fermentation processes [cold (with changed steeping liquor (CSL) and unchanged steeping liquor (USL), Fon and Goun procedures] on the mycotoxin reduction and metabolites profile of ogi, a fermented maize product, was studied. Ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) and gas chromatography linked to high resolution time-of-flight mass spectrometry (GC-HR-TOF-MS) were respectively employed for the mycotoxin and metabolite profiles analyses of the samples. Among the nine mycotoxins detected in the raw maize samples, aflatoxin B1 (AFB1) and fumonisin B1 (FB1) + fumonisin B2 (FB2) concentrations were found to exceed the European Union (EU) maximum limit. Both cold (containing USL and CSL) and Goun fermentation techniques were able to lower the AFB1 concentration below this threshold. The metabolomics result revealed that ogi produced using the cold (USL) and Fon fermentation processes had the highest number of most of the detected important compounds, whereas the Goun fermentation process produced the fewest compounds in total. There was no statistically significant difference in the ability of the specified natural fermentation processes to lower FB1, FB2, FB3, deoxynivalenol (DON), sterigmatocystin (STERIG), and zearalenone concentrations in maize (ZEN). In addition, the results demonstrated that the four natural fermentation processes evaluated had varying effects.

Antifungal activity of Lysinibacillus macroides against toxigenic Aspergillus flavus and Fusarium proliferatum and analysis of its mycotoxin minimization potential

BackgroundToxigenic fungi (Aspergillus and Fusarium) and their metabolites represent the major cause of corn and corn-based products contamination and consequently lead to severe economic and health issues.AimOur current study aimed to investigate the efficacy of using L. macroides Bac6 as a biological control agent against the toxigenic fungi; A. flavus f10 and F. proliferatum f30 and their mycotoxins.ResultsThe results illustrated that A. flavus f10 produced the aflatoxins AFB1 and AFG2 with concentrations of 21.239 and 13.593 ppb, respectively. While F. proliferatum f30 produced fumonisin B1 (9600 ppb). Furthermore, L. macroides showed a high potential for inhibition of toxigenic fungal growth using a dual culture method. F. proliferatum f30 and A. flavus f10 were found to be inhibited by a percentage of 80 and 62.5%, respectively. The results were confirmed using the scanning electron microscope. The antagonistic bacteria, L. macroides, showed chitinase productivity and activity of 26.45 U/L and 0.12 U/mL/min, respectively, which illustrates its potential application as a biocontrol agent. The GC-MS analysis revealed an abundance of Pyrrolo[1,2-a] pyrazine-1,4-dione, Hexahydro in the bacterial supernatant that exhibited antifungal characteristics. L. macroides had a significant reduction of AFB1 and AFG2 produced by A. flavus f10, recording 99.25% and 99% inhibition, respectively. It also showed strong inhibition of fumonisin B1 (90% inhibition) produced by F. proliferatum f30. Conclusion: Thus, the current study is a prospective study evaluating for the first time the potential impact of L. macroides Bac6 against the toxigenic fungi and their toxins.

Laccase Lac-W detoxifies aflatoxin B1 and degrades five other major mycotoxins in the absence of redox mediators

A multicopper oxidase Lac-W from Weizmannia coagulans 36D1 was identified and characterized as a laccase (Lac-W) with a robust enzymatic activity, which was used in various mycotoxins degradation. We demonstrated that Lac-W could directly degrade six major mycotoxins in the absence of redox mediators in pH 9.0, 24h static incubation at room temperature, including aflatoxin B1 (AFB1, 88%), zearalenone (60%), deoxynivalenol (34%), T-2 toxin (19%), fumonisin B1 (18%), and ochratoxin A (12%). The optimal condition for Lac-W to degrade AFB1 was 30 °C, pH 9.0, enzyme-substrate ratio 3U/μg in 24h static condition. Furthermore, we characterized aflatoxin Q1 as a Lac-W-mediated degradation product of AFB1 using UHPLC-MS/MS. Interestingly, degradation products of AFB1 failed to generate cell death and apoptosis of intestinal porcine epithelial cells. Finally, our molecular docking simulation results revealed that the substrate-binding pocket of Lac-W was large enough to allow the entry of six mycotoxins with different structures, and their degradation rates were positively correlated to their interacting affinity with Lac-W. In summary, the unique properties of the Lac-W make it a great candidate for detoxifying multiple mycotoxins contaminated food and feed cost-effectively and eco-friendly. Our study provides new insights into development of versatile enzymes which could simultaneously degrade multiple mycotoxins.

Aspergillus flavus and Fusarium verticillioides and Their Main Mycotoxins: Global Distribution and Scenarios of Interactions in Maize.

Maize is frequently contaminated with multiple mycotoxins, especially those produced by Aspergillus flavus and Fusarium verticillioides. As mycotoxin contamination is a critical factor that destabilizes global food safety, the current review provides an updated overview of the (co-)occurrence of A. flavus and F. verticillioides and (co-)contamination of aflatoxin B1 (AFB1) and fumonisin B1 (FB1) in maize. Furthermore, it summarizes their interactions in maize. The gathered data predict the (co-)occurrence and virulence of A. flavus and F. verticillioides would increase worldwide, especially in European cold climate countries. Studies on the interaction of both fungi regarding their growth mainly showed antagonistic interactions in vitro or in planta conditions. However, the (co-)contamination of AFB1 and FB1 has risen worldwide in the last decade. Primarily, this co-contamination increased by 32% in Europe (2010-2020 vs. 1992-2009). This implies that fungi and mycotoxins would severely threaten European-grown maize.

Monitoring of Mycotoxigenic Fungi in Fish Farm Water and Fumonisins in Feeds for Farmed Colossoma macropomum.

This study aimed to evaluate the occurrence of mycotoxigenic fungi in fish farm water and mycotoxins in feeds for farmed tambaqui (Colossoma macropomum). A total of 40 samples of freshwater from fish farms and 16 samples of feed were collected and analyzed for microbiology. A total of five species of free-living fungi were identified in fish farms: Aspergillus fumigatus, Penicillium citrinum, P. implicatum, Fusarium oxysporum and Alternaria alternata. These fungi species were counted in water samples at 35.14 CFU mL-1 and 24.69 CFU mL-1 in the dry seasons. In all fish farms, there was a higher abundance of fungi species in the rainy season. During visits to the fish farmers, it was possible to verify poor feed storage conditions. Concerning mutations in blood cells, in tambaqui (C. macropomum), a total of 159 anomalies were found, and in Leptodactylus petersii, 299 anomalies were found, with higher incidences in conditions above 1.0 CFU mL-1 in log10(x+1) fungi and in the rainy season. The occurrence of mycotoxicological contamination was confirmed in 81.25% of the analyzed samples. The quantified mycotoxin was Fumonisins B1 + B2 (375 to 1418 μg kg-1). Pearson's correlation analysis showed a significant positive correlation between Fumonisins and feed samples (r = 0.83). There was also a significant positive correlation between the abundance of fungi in water and the quantification of Fumonisins (r = 0.79). Based on the results obtained, it can be concluded that free-living fungi can be used as bioindicators of water quality in fish farms. Consequently, the lack of good management practices caused microbiological contamination of the aquatic environment.

Optimization Workflow of Fumonisin Esterase Production for Biocatalytic Degradation of Fumonisin B1.

Industrial enzyme production with the Pichia pastoris expression system requires a well-characterized production strain and a competitively priced fermentation medium to meet the expectations of the industry. The present work shows a workflow that allows the rapid and reliable screening of transformants of single copy insertion of the target production cassette. A constitutive expression system with the glyceraldehyde-3-phosphate dehydrogenase promoter (pGAP) with homology arms for the glycerol kinase 1 (GUT1) was constructed for the targeted integration of the expression plasmid in a KU70 deficient Pichia pastoris and the production of a bacterial fumonisin esterase enzyme (CFE). A robust colony qPCR method was developed for the copy number estimation of the expression cassette. Optimization of the protein production medium and the scale-up ability was aided by design of experiments (DOE) approach resulting in optimized production conditions at a semi-industrial scale. A novel fermentation medium containing 3% inactivated yeast and 2% dextrose in an ammonium-citrate buffer (IYD) was shown to be a promising alternative to YPD media (containing yeast extract, peptone, and dextrose), as similar protein titers could be obtained, while the cost of the medium was reduced 20-fold. In a demonstration-scale 48 h long fed-batch fermentation, the IYD media outperformed the small-scale YPD cultivation by 471.5 ± 22.6%.

Co-occurrence of mycotoxins and other fungal metabolites in total mixed rations of cows from dairy farms in Punjab, Pakistan

After India and the USA, Pakistan is the third country leading in global dairy production, a sector of very high socioeconomic relevance in Asia. Mycotoxins can affect animal health, reproduction and productivity. This study analysed a broad range of co-occurring mycotoxins and fungal secondary metabolites derived from Alternaria, Aspergillus, Fusarium, Penicillium and other fungal species. To complete this, a validated multi-metabolite liquid chromatography/electrospray ionization-tandem mass spectrometric (LC/ESI–MS/MS) method was employed, detecting 96 of > 500 tested secondary fungal metabolites. This first preliminary study demonstrated that total mixed rations (TMRs) (n = 30) from big commercial dairy cattle farms (> 200 lactating cows) in Punjab, Pakistan, presented ubiquitous contamination with mixtures of mycotoxins. The mean of mycotoxins per sample was 14, ranging from 11 to 20 mycotoxins among all TMR samples. Metabolites derived from other fungi and Fusarium spp. showed the highest levels, frequency and diversity among the detected fungal compounds. Among the most prevalent mycotoxins were Fusarium toxins like fumonisins B1 (FB1) (93%), B2 (FB2) (100%) and B3 (FB3) (77%) and others. Aflatoxin B1 (AFB1) was evidenced in 40% of the samples, and 7% exceeded the EU maximum limit for feeding dairy cattle (5 µg/kg at 88% dry matter). No other mycotoxin exceeds the EU guidance values (GVs). Additionally, we found that dietary ingredients like corn grain, soybean meal and canola meal were related to increased contamination of some mycotoxins (like FB1, FB2 and FB3) in TMR from the province of Punjab, Pakistan. Among typical forage sources, the content of maize silage was ubiquitous. Individually, the detected mycotoxins represented relatively low levels. However, under a realistic scenario, long-term exposure to multiple mycotoxins and other fungal secondary metabolites can exert unpredictable effects on animal health, reproduction and productivity. Except for ergot alkaloids (73%), all the groups of metabolites (i.e. derived from Alternaria spp., Aspergillus spp., Fusarium spp., Penicillium spp. and other fungi) occurred in 100% of the TMR samples. At individual levels, no other mycotoxins than AFB1 represented a considerable risk; however, the high levels of co-occurrence with several mycotoxins/metabolites suggest that long-term exposure should be considered because of their potential toxicological interactions (additive or synergistic effects).

Fungal microbiome related to mycotoxin contamination in medicinal and edible seed Semen Persicae

Medicinal and edible seed Semen Persicae is susceptible to mycotoxin and fungal contamination. However, the occurrence of mycotoxin contamination and fungal infection is still unclear. In this paper, ultra-high performance liquid chromatography-tandem triple quadrupole mass spectrometry and high-throughput sequencing were conducted to determine the mycotoxin contents and fungal abundances of Semen Persicae. 42.86% of samples were positive for aflatoxin B1 (26.48–48.37 μg/kg) and 28.57% of samples were positive for aflatoxin B2 (1.47–4.82 μg/kg). Ochratoxin A and fumonisin B1 were only detected in one sample (91.02 and 34.61 μg/kg, respectively). Chao 1 and Shannon indices were significantly higher in the Dalian of Liaoning, Baotou of Innermongolia and Langfang of Hebei regions than in other groups. Ascomycota, Basidiomycota, Wallemia, Candica, Saccharomyces and Aspergillus were the predominant fungi and they were significantly region-specific. Simultaneously, the diversity, composition and co-occurrence network complexity in the mycotoxin-free group were significantly higher than those in the mycotoxin-contaminated group. Spearman correlation analysis showed aflatoxins, ochratoxin A and fumonisins contents were positively and significantly correlated with the abundances of Aspergillus, Rhodotorula, Wallemia and Candida. In conclusion, this study reported the prevalence of mycotoxin contamination and the great diversity of fungi associated with Semen Persicae for the first time, providing an early warning for subsequent potential mycotoxin biosynthesis.

Inter-laboratory validation of liquid chromatography-tandem mass spectrometry multi-mycotoxin determination in animal feed - method transfer from the reference laboratory to regional laboratories.

The results are presented of the inter-laboratory validation of a liquid chromatography-tandem mass spectrometry method for the determination of eight mycotoxins (aflatoxin B1, deoxynivalenol, fumonisin B1, fumonisin B2, ochratoxin A, toxin T-2, toxin HT-2 and zearalenone) in animal feeds. This study was an essential part of the method's transfer from the National Reference Laboratory to six regional laboratories in Poland working in the official survey of mycotoxins in feed. The laboratories received a batch of standard solutions, blank samples and quality control materials on which to perform analysis with one procedure and different liquid chromatography-tandem mass spectrometry conditions. The validation results show good precision (reproducibility coefficient of variation 3.7-20.5%) and accuracy of the method (recovery 89-120% and trueness 94-103%) and sufficient skills of the laboratory personnel. The study is an example of the successful transfer of the method among laboratories.

P18-08: Investigation of the effects of fumonisin B1 on lipotoxicity in human pancreatic cell

P18-08: Investigation of the effects of fumonisin B1 on lipotoxicity in human pancreatic cell

Graphene oxide-Mn3O4 nanocomposites for advanced electrochemical biosensor for fumonisin B1 detection

Occurrence of mycotoxins in food samples threat to its safety issue due to the presence of high toxicity and carcinogenic behavior, thus requiring highly sensitive and selective detection. Herein, the trimanganese tetraoxide (Mn3O4) nanoparticles in combination with graphene oxide (GO) nanocomposite were used to enhance the electrochemical performance for fabrication of electrochemical biosensor for fumonisin B1 (FB1) detection. The various characterization tools were used to validate the fabrication of GOMn3O4 nanocomposites. To fabricate the electrochemical biosensor on an indium tin oxide (ITO) coated glass substrate, a thin film of GOMn3O4 nanocomposite was prepared using electrophoretic deposition technique, and antibodies (ab-FB1) were immobilized onto the electrode for selective FB1 detection. The differential pulse voltammetry technique was used to observe the sensing performance. The non-binding sites of the ab-FB1 on the immunoelectrode were blocked with bovine serum albumin (BSA). The biosensor electrode was fabricated as BSA/ab-FB1/GOMn3O4/ITO for the detection of FB1. The sensitivity of the biosensor was obtained as 10.08 μA ml ng−1 cm−2 in the detection range of 1 pg ml−1 to 800 ng ml−1 with a limit of detection of 0.195 pg ml−1. In addition, the recovery of BSA/ab-FB1/GOMn3O4/ITO immunoelectrodes was also performed on sweet corn samples and is calculated to be 98.91%.

Cell cycle and enzymatic activity alterations induced by ROS production in human neuroblastoma cells SH-SY5Y exposed to Fumonisin B1, Ochratoxin A and their combination

The presence of mycotoxins such as Fumonisin B1(FB1) and Ochratoxin A (OTA) in food and feed has become a threat to human and animal health since they can produce several afflictions. Different mechanisms of action by which they exercise their cytotoxic activity have been attributed to them, including the production of reactive oxygen species (ROS). For this reason, a measurement of the production of ROS species, and an evaluation of the intrinsic cell enzymatic antioxidant activity, including glutathione peroxidase (GPx), glutathione transferase (GTS), and catalase (CAT) together with a cytotoxicity and cell cycle assay have been performed in undifferentiated SH-SY5Y cells exposed to FB1, OTA and [FB1 + OTA] after 24 h and 48 h. FB1 and OTA. Monitoring of intracellular ROS production was carried out by the H2-DCFDA probe; while spectrometry analysis of absorbances was used for measuring GPx, GST and CAT activity. Finally, cell proliferation and cell cycle distribution were studied by flow cytometry. When cells were treated with OTA, an increase in GPx and GST activity was observed compared to FB1 and [FB1 + OTA]; conversely, a decrease in CAT activity was observed when cells were exposed to OTA coinciding with the results observed for ROS measurement. Regarding the cell cycle, when cells were exposed to OTA, a decrease in G0/G1 was detected, revealing an arrest of cell division for SH-SY5Y cells at the concentrations studied.

Orosomucoid proteins limit endoplasmic reticulum stress in plants.

Sphingolipids are cell membrane components and signaling molecules that induce endoplasmic reticulum (ER) stress responses, but the underlying mechanism is unknown. Orosomucoid proteins (ORMs) negatively regulate serine palmitoyltransferase activity, thus helping maintain proper sphingolipid levels in humans, yeast, and plants. In this report, we explored the roles of ORMs in regulating ER stress in Arabidopsis thaliana. Loss of ORM1 and ORM2 function caused constitutive activation of the unfolded protein response (UPR), as did treatment with the ceramide synthase inhibitor Fumonisin B1 (FB1) or ceramides. FB1 treatment induced the transcription factor bZIP28 to relocate from the ER membrane to the nucleus. The transcription factor WRKY75 positively regulates the UPR and physically interacted with bZIP28. We also found that the orm mutants showed impaired ER-associated degradation (ERAD), blocking the degradation of misfolded MILDEW RESISTANCE LOCUS-O 12 (MLO-12). ORM1 and ORM2 bind to EMS-MUTAGENIZED BRI1 SUPPRESSOR 7 (EBS7), a plant-specific component of the Arabidopsis ERAD complex, and regulate its stability. These data strongly suggest that ORMs in the ER membrane play vital roles in the UPR and ERAD pathways to prevent ER stress in Arabidopsis. Our results reveal that ORMs coordinate sphingolipid homeostasis with ER quality control and play a role in stress responses.

CRISPR-Cas12a-based aptasensor for sensitive and selective FB1 detection

Fumonisin B1 (FB1) is a common mycotoxin found in agricultural products. Therefore, establishing rapid detection methods is an important means to prevent the harm of FB1. This study was based on the clustered, regularly spaced short palindromic repeats (CRISPR)-Cas12a system with the introduction of aptamer F10. This study aimed to design CRISPR RNA (crRNA) to specifically recognize the aptamer F10, which formed the competitive relationship between the target molecule and crRNA for nucleic acid aptamer. Finally, a new type of biosensor was established using the trans-cleavage activity of Cas12a protein and amplifying the signal with a fluorescent probe. This study observed a linear relationship of FB1 concentrations in the range of 25–500 nM. The standard curve was y = −0.2586 × x + 775.3, R2 = 0.9922, and the limit of detection (LOD) was 16.84 nM. The recovery of the maize sample was 92.2–101.93% and 92.24–103.96%. The total assay time was 40 min. The biosensor showed high specificity and sensitivity for FB1 after the introduction of the aptamer F10, and the workflow was simple, convenient, and fast, which was suitable for point-of-care (POC) detection in the field. Our designed biosensor validated the principle of detecting small molecules using CRISPR-Cas12a systems, further facilitating its application in the diagnostic field.

Chronic oral exposure to low-concentration fumonisin B2 significantly exacerbates the inflammatory responses of allergies in mice via inhibition of IL-10 release by regulatory T cells in gut-associated lymphoid tissue.

Contamination with fumonisins produced by Fusarium spp. is rapidly growing in both developing and developed countries. The purpose of this study was to determine whether oral exposure to fumonisin contributed to the development of allergic diseases. We initially examined the immunotoxic potential of short-term, oral administration of fumonisin B1 (FB1, 1mg/kg) and fumonisin B2 (FB2, 1mg/kg), both naturally occurring fumonisins, using a BALB/c mouse model of allergic contact dermatitis and Dermatophagoides farina-induced asthma. Using an NC/nga mouse model of atopic dermatitis (AD), we evaluated the adverse effects of subchronic oral exposure to low concentrations of FB2 (2 or 200μg/kg). Finally, we explored the influence of FB2 on regulatory T cell proliferation and function in mesenteric lymph nodes after 1-week oral exposure to FB2 in BALB/c mice. Oral exposure to FB2 markedly exacerbated the symptoms of allergy, including skin thickness, histological evaluation, immunocyte proliferation, and proinflammatory cytokine production, although no change was observed following exposure to FB1. Furthermore, oral exposure to low concentrations of FB2 considerably exacerbated the AD scores, skin thickness, transepidermal water loss, histological features, and proinflammatory cytokine production. The aggravated allergic symptoms induced by oral exposure to FB2 could be attributed to the direct inhibition of IL-10 production by regulatory T cells in mesenteric lymph nodes. Our findings indicate that the recommended maximum fumonisin level should be reconsidered based on the potential for allergy development.

Detection of fumonisin among different strains of Fusarium spp. associated with bakanae disease of rice (Oryza sativa L.) using molecular markers

Bakanae disease caused by Fusarium fujikuroi of basmati rice causes huge economic losses varying with varieties produced, with a frequency of 3.0-95.4%. The Fusarium spp. associated with bakanae disease produce fumonisins, a group of structurally similar sphingosine analogue mycotoxins, among which Fumonisin B1 is the most prevalent and active (FB1). The worst harm to both people and animal wellbeing is created by fumonisins, which infect feed and food sources. IARC, a global organization dedicated to cancer research, classified FB1 as a potential causing human cancer (Group 2B). Altogether 26 strains of Fusarium spp. from bakanae infected samples of various popular basmati rice varieties collected from Hisar, Jind, Fatehabad, Bhiwani, Sirsa, Panipat, Sonipat, Karnal, Yamunanagar, Kaithal and Kurukshetra (eleven) districts of Haryana state. Two specific primers namely VERTF and polyketide synthase (PKS) (involved in fumonisin biosynthesis) FUM (rp 32 and rp 33) were utilized in this investigation to differentiation between fumonisin-producing and non-producing strains employing PCR technique. Twenty-two strains were significant for the VERTF primer and showed the capacity to generate fumonisin, while four isolates evaluated negative for both primers. The FUM specific primer displayed positive respose only in nine strains and rest were negative. The present study provides a rapid and specific method that helped in accurate differentiation between fumonisin-producing and non-producing strains.

Visual Measurement of Fumonisin B1 with Bipolar Electrodes Array-Based Electrochemiluminescence Biosensor

Fumonisin B1 (FB1) is a toxin produced by the metabolism of Fusarium oxysporum, which can cause serious effects on the nervous, respiratory, digestive, and reproductive systems of humans or animals; it is known as one of the highly toxic epidemic contaminants. Herein, we report the visual inspection of FB1 using bipolar electrodes (BPEs) with an array-based electrochemiluminescence (ECL) platform. The sensor consists of a PDMS cover and a glass substrate containing an array of 10 ITO electrodes. A specific sensing interface was constructed on the cathode of the BPE, which could modulate the ECL reactions that occurred at the anode of BPEs. To amplify the ECL signal, methylene blue (MB)-encapsulated Zr-MOFs (MB@Zr-MOFs) were synthesized and immobilized on the cathode of the BPE, which could amplify the ECL signal at the anode. By coupling the cyclic amplification effect of the DNA walker and nicking endonuclease (Nb.BbvCI), the biosensor can realize the visual measurement of FB1 in the range of 5 × 10−5~0.5 ng/mL. In addition, the developed biosensor was used to monitor the concentration of FB1 in maize and peanut samples. The recoveries were in the range of 99.2%~110.6%, which demonstrated the good accuracy of the designed BPE-ECL biosensor for FB1 assay in food samples.