Aflatoxin B1 Toxicity Research Articles

Bioenergetic Status of the Intestinal and Hepatic Cells after Short Term Exposure to Fumonisin B1 and Aflatoxin B1.

Fumonisin B1 (FB1) and aflatoxin B1 (AFB1) are frequent contaminants of staple foods such as maize. Oral exposure to these toxins poses health hazards by disrupting cellular signaling. However, little is known regarding the multifaced mitochondrial dysfunction-linked toxicity of FB1 and AFB1. Here, we show that after exposure to FB1 and AFB1, mitochondrial respiration significantly decreased by measuring the oxygen consumption rate (OCR), mitochondrial membrane potential (MMP) and reactive oxygen species (ROS). The current work shows that the integrity of mitochondria (MMP and ROS), that is the central component of cell apoptosis, is disrupted by FB1 and AFB1 in undifferentiated Caco-2 and HepG2 cells as in vitro models for human intestine and liver, respectively. It hypothesizes that FB1 and AFB1 could disrupt the mitochondrial electron transport chain (ETC) to induce mitochondrial dysfunction and break the balance of transferring H+ between the mitochondrial inner membrane and mitochondrial matrix, however, the proton leak is not increasing and, as a result, ATP synthesis is blocked. At the sub-toxic exposure of 1.0 µg/mL for 24 h, i.e., a viability of 95% in Caco-2 and HepG2 cells, the mitochondrial respiration was, however, stimulated. This suggests that the treated cells could reserve energy for mitochondrial respiration with the exposure of FB1 and AFB1, which could be a survival advantage.

Gasdermin D-mediated microglial pyroptosis exacerbates neurotoxicity of aflatoxins B1 and M1 in mouse primary microglia and neuronal cultures

Aflatoxin B1 (AFB1) disrupts the blood-brain barrier by poisoning the vascular endothelial cells and astrocytes that maintain it. It is important to examine whether aflatoxin B1 or its metabolite, aflatoxin M1 (AFM1), affect microglia, which as the “immune cells” in the brain may amplify their damaging effects. Here we evaluated the toxicity of AFB1 and AFM1 against primary microglia and found that both aflatoxins decreased the viability of primary microglia and increased the leakage of lactate dehydrogenase, gamma-H2AX expression, nuclear lysis, necrosis and apoptosis in a dose-dependent manner. The potential contribution of microglia to the toxic effects of aflatoxins was assessed in transwell co-culture experiments involving microglia, neurons, astrocytes, oligodendrocytes or neural stem/precursor cells. And we found that the toxic effects of both aflatoxins on various types of nervous system cells were greater in the presence of microglia than in their absence. We also found that both aflatoxins induced gasdermin D-mediated microglial pyroptosis and inflammatory cytokine expression by activating the NLRP3 inflammasome. Blockade of gasdermin D activity in AFB1- or AFM1-treated primary microglia using dimethyl fumarate (DMF) reduced the release of IL-1β, IL-18 and nitric oxide, as well as the neurotoxicity of microglia-conditioned medium to neurons, astrocytes, oligodendrocytes and neural stem/precursor cells. These data suggested that the toxicity of AFB1 and AFM1 on various cells of the central nervous system is due, remarkably, the gasdermin D-mediated microglial pyroptosis exacerbates their neurotoxicity.

Taurine attenuates AFB1-induced liver injury by alleviating oxidative stress and regulating mitochondria-mediated apoptosis

Aflatoxin B1 (AFB1), which widely exists in soil and crops, is the most toxic aflatoxin and a carcinogen to humans and animals. The liver is the main organ that processes AFB1 and other mycotoxins and is also the main target of AFB1 toxicity. Taurine is known to exhibit a variety of physiological and pharmacological functions. In the present study, taurine was administered to detect the protective effect and mechanism of taurine in AFB1-induced liver injury in rats. The results showed that taurine inhibited the increase in hepatic injury indices, hepatic apoptosis and hepatic malondialdehyde (MDA) contents while significantly enhanced the hepatic activities of antioxidant enzymes and mitochondrial function-related indices in AFB1-poisoned rats. Meanwhile, the expression levels of key factors in the Nrf2 signalling pathway were upregulated while the expression levels of key proteins in the mitochondria-mediated apoptotic pathway were downregulated after taurine administration. The results showed that taurine can reverse AFB1-induced liver injury and abnormal apoptosis through activation of the Nrf2 signalling pathway and its downstream antioxidant enzymes, which further protects mitochondria from oxidative stress and the subsequent apoptotic pathway.

A sensitive aflatoxin B1 electrochemical aptasensor based on ferrocene-functionalized hollow porous carbon spheres as signal amplifier

Due to the high toxicity and carcinogenicity of Aflatoxin B1 (AFB1), a sensitive, low-cost and simple method to accurately detect AFB1 in foodstuffs is highly desirable. Herein, a sensitive and selective AFB1 electrochemical aptasensor was developed by using ferrocene immobilized hollow porous carbon spheres (HPCS-Fc) as the electrochemical signal tag. Attributed to the large surface and high conductivity of HPCS, the prepared Fc-HPCS showed the high load amount of Fc and HPCS-Fc labelled GC electrode displayed large oxidation peak current. To further improve the biosensing ability, tetrahedral DNA nanostructures (TDNs) was attached on the biosensing interface to control the orientation of HPCS-Fc-cDNA. Based on the above advantages, the HPCS-Fc labelled electrochemical aptasensor exhibited high sensitivity towards AFB1 in a wide linear range from 1.0 × 10−2 pg mL−1 to 100.0 μg mL−1 and a low detection limit down to 3.3 × 10−5 ng mL−1. Furthermore, the developed aptasensor was applied to detect AFB1 in wheat powder samples with satisfactory recoveries of 91.7%∼107.7%, demonstrating its potential application in testing AFB1 in food samples.

Multi-Omics Reveal Additive Cytotoxicity Effects of Aflatoxin B1 and Aflatoxin M1 toward Intestinal NCM460 Cells.

Aflatoxin B1 (AFB1) is a common crop contaminant, while aflatoxin M1 (AFM1) is implicated in milk safety. Humans are likely to be simultaneously exposed to AFB1 and AFM1; however, studies on the combined interactive effects of AFB1 and AFM1 are lacking. To fill this knowledge gap, transcriptomic, proteomic, and microRNA (miRNA)-sequencing approaches were used to investigate the toxic mechanisms underpinning combined AFB1 and AFM1 actions in vitro. Exposure to AFB1 (1.25–20 μM) and AFM1 (5–20 μM) for 48 h significantly decreased cell viability in the intestinal cell line, NCM460. Multi-omics analyses demonstrated that additive toxic effects were induced by combined AFB1 (2.5 μM) and AFM1 (2.5 μM) in NCM460 cells and were associated with p53 signaling pathway, a common pathway enriched by differentially expressed mRNAs/proteins/miRNAs. Specifically, based on p53 signaling, cross-omics showed that AFB1 and AFM1 reduced NCM460 cell viability via the hsa-miR-628-3p- and hsa-miR-217-5p-mediated regulation of cell surface death receptor (FAS), and also the hsa-miR-11-y-mediated regulation of cyclin dependent kinase 2 (CDK2). We provide new insights on biomarkers which reflect the cytotoxic effects of combined AFB1 and AFM1 toxicity.

Aflatoxin B1 exposure disrupts organelle distribution in mouse oocytes.

Aflatoxin B1 (AFB1) is a secondary metabolite produced by the fungus Aspergillus, which is ubiquitous in moldy grain products. Aflatoxin B1 has been reported to possess hepatotoxicity, renal toxicity, and reproductive toxicity. Previous studies have shown that AFB1 is toxic to mammalian oocytes. However, the potential toxicity of AFB1 on the organelles of mouse oocytes is unknown. In this study, we found that exposure to AFB1 significantly reduced mouse oocyte development capacity. Further analysis showed that the endoplasmic reticulum (ER) failed to accumulate around the spindle, and scattered in the cytoplasm under AFB1 exposure. Similar to the ER, the Golgi apparatus showed a uniform localization pattern following AFB1 treatment. In addition, we found that AFB1 exposure caused the condensation of lysosomes in the cytoplasm, presenting as a clustered or spindle peripheral-localization pattern, which indicated that protein modification, transport, and degradation were affected. Mitochondrial distribution was also altered by AFB1 treatment. In summary, our study showed that AFB1 exposure had toxic effects on the distribution of mouse oocyte organelles, which further led to a decline in oocyte quality.

Condensed tannins protect against aflatoxin B1-induced toxicity in Lateolabrax maculatus by restoring intestinal integrity and regulating bacterial microbiota

Condensed tannins (CT) have been shown to enhance the exogenous stress resistance of fish, whereas the protective effects of CT against damage induced by dietary aflatoxin B1 (AFB1) on the growth and health of fish have not been evaluated. A 56-day feeding trial was carried out to assess the effects of CT on alleviating dietary AFB1-induced damages in growth, antioxidant and immune response, intestinal integrity and bacterial microbiota of the Chinese sea bass (Lateolabrax maculatus). Three diets were formulated to contain 0 mg/kg of AFB1 and 0 g/kg of CT (G1), 1 mg/kg of AFB1 and 0 g/kg of CT (G2), and 1 mg/kg of AFB1 and 1 g/kg of CT (G3), respectively. Each diet was randomly assigned to three tanks with 40 fish in each tank. Fish were fed to apparent satiation twice daily. Results indicated that fish fed G2 had lower (P < 0.05) final body weight, weight gain rate, specific growth rate, feed intake, viscerosomatic index, total antioxidant capacity, superoxide dismutase, catalase, alkaline phosphatase and lysozyme, but higher (P < 0.05) malondialdehyde, diamine oxidase and lipopolysaccharide compared to those of fish fed G1 and G3. Fish fed G3 had higher (P < 0.05) villus length and intestinal tight junction protein gene expression (ZO-1, Claudin-3 and Occludin), but lower (P < 0.05) villus width than G2. Fish had similar growth performance, serum parameters and intestinal morphology between G1 and G3. In the top 10 dominant genera of intestinal microbiota, the relative abundance of Pseudomonas was higher in G2 but lower in G3 than in G1 (P < 0.05). Compared with G1, G2 and G3 had higher relative abundances of Aeromonas and Klebsiella, but lower relative abundance of Plesiomonas (P < 0.05). Dietary treatments did not alter the alpha and beta diversity of bacterial communities. In conclusion, dietary inclusion of 1 mg/kg of AFB1 reduced feed intake and decreased growth of L. maculatus. AFB1 reduced serum antioxidant capacity and immunity, increased intestinal permeability, induced intestinal damage and altered bacterial microbiota of fish. Supplementation of 1 g/kg of grape seed CT effectively protected against AFB1 toxicity by alleviating the negative impacts of dietary AFB1 exerted on fish. This study provides a rational for the application of CT in aquaculture to prevent fish from AFB1-induced damage.

Dietary phillygenin supplementation ameliorates aflatoxin B1-induced oxidative stress, inflammation, and apoptosis in chicken liver

Aflatoxin B1 (AFB1), a mycotoxin contaminating food and feed, can trigger liver immune toxicity and threaten the poultry industry. Phillygenin (PHI) is a natural lignan derived primarily from Forsythia suspensa with hepatoprotective pharmacological and medicinal properties. This research aimed to investigate the preventive effects of PHI on the toxicity of AFB1 in the liver of chickens. Chickens were administered with AFB1 (2.8 mg/kg) and/or treated with PHI (24 mg/kg) for 33 days. The histopathological changes, serum biochemical indices, oxidative damage, inflammatory mediators, apoptosis, and activation of the NF-κB and Nrf2 signaling pathways were measured. Results revealed that dietary PHI ameliorated liver function indicators, reduced the malondialdehyde and inflammatory mediator production and the apoptotic cell number, and increased the antioxidant enzyme contents and Bcl-2 level. The quantitative realtime PCR and Western blot results revealed that PHI reduced p53, cytochrome c, Bax, caspase-9, and caspase-3 levels, normalized the NF-κB p65 phosphorylation, and upregulated the Nrf2 and its downstream genes expression in chicken liver. These results indicated that PHI has beneficial effects on AFB1-induced liver damage, oxidative damage, inflammatory response, apoptosis, and immunotoxicity by inhibiting NF-κB and activating the Nrf2 signaling pathway in chickens. This study provides new insight into the therapeutic uses of PHI.

Comparison Evaluation of the Biological Effects of Sterigmatocystin and Aflatoxin B1 Utilizing SOS-Chromotest and a Novel Zebrafish (Danio rerio) Embryo Microinjection Method.

Aflatoxin B1 (AFB1) is a potent mycotoxin and natural carcinogen. The primary producers of AFB1 are Aspergillus flavus and A. parasiticus. Sterigmatocystin (STC), another mycotoxin, shares its biosynthetic pathway with aflatoxins. While there are abundant data on the biological effects of AFB1, STC is not well characterised. According to published data, AFB1 is more harmful to biological systems than STC. It has been suggested that STC is about one-tenth as potent a mutagen as AFB1 as measured by the Ames test. In this research, the biological effects of S9 rat liver homogenate-activated and non-activated STC and AFB1 were compared using two different biomonitoring systems, SOS-Chromotest and a recently developed microinjection zebrafish embryo method. When comparing the treatments, activated STC caused the highest mortality and number of DNA strand breaks across all injected volumes. Based on the E. coli SOS-Chromotest, the two toxins exerted the same genotoxicities. Moreover, according to the newly developed zebrafish microinjection method, STC appeared more toxic than AFB1. The scarce information correlating AFB1 and STC toxicity suggests that AFB1 is a more potent genotoxin than STC. Our findings contradict this assumption and illustrate the need for more complex biomonitoring systems for mycotoxin risk assessment.

English

Aflatoxin occurrence in poultry feed causes aflatoxicosis in birds and poses health hazards to the consumers. Aflatoxin B1 (AfB1) is the most predominant and toxic metabolite that is controlled through addition of argillaceous clays as non-nutritive additives. Non-smectitic indigenous clay reserves need testing as AfB1 adsorbent. With detailed mineral and adsorption characteristics, three indigenous non-smectitic clays: (i) palygorskite, (ii) palygorskite-smectite mix, and (iii) interstratified smectite with hydroxy interlayered smectite were tested against 250 µg kg-1 AfB1 contamination in a poultry feeding trial with three replications at 1% and 2% (w/w) with positive and negative controls. A total of 330 Ross-308 male broiler chicks, initially reared on clean feed under controlled conditions of light and humidity, were distributed into eleven treatment combinations in a completely randomized design with 30 birds in each treatment on an equal weight basis with three replications at day 14 and fed on experimental feeds for three weeks. Three birds from each pen were randomly slaughtered at day 35 and for each replicated treatment, body weight gain, feed intake, and internal organs weight and morphology were recorded. AfB1 contamination reduced weight gain (p 0.0001), feed conversion ratio (p 0.0001) and feed intake (p 0.0001) while clays addition in the toxin feed effectively controlled AfB1 toxicity as suggested by improved body weight, weight gain rate and feed consumption compared to the toxin fed birds. The liver morphology was comparatively better in palygorskite-smectite mix treatment when applied at 1% and the darkish colour was also improved with addition of the clay in the toxin feed. AfB1 feeding caused a 75% reduction in weight gain compared to the clean feed. Palygorskite and palygorskite-smectite mix clays were better than interstratified clay in increasing weight gain and caused a 60% and 65% increase over toxin feed treatment when applied at 1% and 2%, respectively. In conclusion, the indigenous clay sources overall and palygorskite-smectite mix in particular has the potential for use as a mycotoxin binder for controlling AfB1 incidence in poultry

Caffeic acid mitigates aflatoxinB1‐mediated toxicity in the male rat reproductive system by modulating inflammatory and apoptotic responses, testicular function, and the redox‐regulatory systems

Aflatoxin B1 (AFB1 ) is a toxic metabolite of public health concern. The present study investigates the protective effects of caffeic acid (CA) against AFB1 -induced oxidative stress, inflammation, and apoptosis in the hypothalamus, epididymis, and testis of male rats. Five experimental rat cohorts (n = 6) were treated per os for 28 consecutive days as follows: Control (Corn oil 2 ml/kg body weight), AFB1 alone (50μg/kg), CA alone (40 mg/kg) and the co-treated rat cohorts (AFB1 : 50μg/kg + CA1: 20 or 40 mg/kg). Following sacrifice, the biomarkers of hypothalamic, epididymal, and testicular toxicities, antioxidant enzyme activities, myeloperoxidase (MPO) activity, as well as levels of nitric oxide (NO), reactive oxygen and nitrogen (RONS) species and lipid peroxidation (LPO) were analysed spectrophotometrically. Besides, the concentration of tumour necrosis factor-alpha (TNF-α), Bcl-2 and Bax proteins were assessed using ELISA. Results showed that the AFB1 -induced decrease in biomarkers of testicular, epididymal and hypothalamic toxicity was significantly (p < .05) alleviated in rats coexposed to CA. Moreover, the reduction of antioxidant status and the increase in RONS and LPO were lessened (p < .05) in rats co-treated with CA. AFB1 mediated increase in TNF-α, Bax, NO and MPO activity were reduced (p< .05) in the hypothalamus, epididymis, and testis of rats coexposed to CA. In addition, Bcl-2 levels were reduced in rats treated with CA dose-dependently. Light microscopic examination showed that histopathological lesions severity induced by AFB1 were alleviated in rats coexposed to CA. Taken together, the amelioration of AFB1 -induced neuronal and reproductive toxicities by CA involves anti-inflammatory, antioxidant, antiapoptotic mechanisms in rats. PRACTICAL APPLICATIONS: The beneficial antioxidant effects of caffeic acid (CA) are attributed to CA delocalized aromatic rings and free electrons, easily donated to stabilize reactive oxygen species. We report in vivo findings on CA and AfB1 mediated oxidative stress and reproductive dysfunction in rats. CA conjugated esters including chlorogenic acids are widely distributed in plants, and they act as a dietary source of natural defense against infections. CA can chelate heavy metals and reduce production of damaging free radicals to cellular macromolecules. Along these lines, CA can stabilize aflatoxin B1-epoxide as well and avert deleterious conjugates from forming with deoxyribonucleic acids. Hence CA, as a dietary phytochemical can protect against the damaging effects of toxins including aflatoxin B1 that contaminate food. CA dose-dependently abated oxidative, inflammatory, and apoptotic stimuli, improved functional characteristics of spermatozoa and reproductive hormone levels, and prevented histological alterations in experimental rats' hypothalamus and reproductive organs brought about by AFB1 toxicity.

Dietary Lactobacillus acidophilus ATCC 4356 Relieves the Impacts of Aflatoxin B1 Toxicity on the Growth Performance, Hepatorenal Functions, and Antioxidative Capacity of Thinlip Grey Mullet (Liza ramada) (Risso 1826).

Dietary Lactobacillus acidophilus ATCC 4356 was used to relieve the impacts of aflatoxin B1 toxicity on the performances of Liza ramada. The control diet was without any additives, while the second and third diets were supplemented with aflatoxin B1 at 0.5 and 1mg/kg. The fourth diet was supplemented with Lb. acidophilus ATCC 4356 at 1 × 106CFU/mL per kg diet, while the fifth with aflatoxin B1 at 1mg/kg and Lb. acidophilus ATCC 4356 at 1 × 106CFU/mL per kg diet. The growth performance markedly increased (p < 0.05) in L. ramada fed Lb. acidophilus ATCC 4356, while aflatoxin B1 at 0.5 and 1mg/kg groups showed a severe reduction. The red blood cells, hemoglobulin, hematocrit, and white blood cells were markedly increased in L. ramada fed Lb. acidophilus ATCC 4356 while decreased (p < 0.05) in fish fed aflatoxin B1 at 0.5 and 1mg/kg. The blood total protein and albumin were markedly increased (p < 0.05) in L. ramada fed Lb. acidophilus ATCC 4356 while reduced in aflatoxin B1 at 0.5 and 1mg/kg groups. The levels of total cholesterol and triglycerides were meaningfully increased in fish of the Lb. acidophilus ATCC 4356 and aflatoxin B1 at 1mg/kg groups while decreased in aflatoxin B1 at 0.5 and 1mg/kg groups. Alanine aminotransferase, aspartate aminotransferase, creatinine, and urea levels were markedly decreased (p < 0.05) in fish-fed Lb. acidophilus ATCC 4356 while increased in aflatoxin B1 at 0.5 and 1mg/kg groups. The highest levels of blood glucose and cortisol were seen in fish contaminated with aflatoxin B1 at 1mg/kg, while the lowest levels were observed in the fish fed Lb. acidophilus ATCC 4356 group (p < 0.05). The catalase and superoxide dismutase were markedly enhanced in the Lb. acidophilus ATCC 4356 group and severely declined in aflatoxin B1 at 0.5 and 1mg/kg groups (p < 0.05). The malondialdehyde level was markedly reduced in fish fed Lb. acidophilus ATCC 4356 with or without aflatoxin B1 at 1mg/kg diets while increased in fish contaminated with aflatoxin B1 at 0.5 and 1mg/kg (p < 0.05). The control group had lower malondialdehyde levels than the aflatoxin B1 at 1mg/kg group and higher than the Lb. acidophilus ATCC 4356 with or without aflatoxin B1 toxicity (p < 0.05). Histopathological examination revealed impaired intestines and livers in fish contaminated with aflatoxin B1 while Lb. acidophilus ATCC 4356 relieves the inflammation and protected the intestines and livers. In conclusion, dietary Lb. acidophilus ATCC 4356 is recommended to relieve the impacts of aflatoxicosis-induced hepatorenal failure and oxidative stress in L. ramada.

Metagenomic and proteomic approaches in elucidating aflatoxin B1 detoxification mechanisms of probiotic Lactobacillus casei Shirota towards intestine

The modulation of gut microbiota and proteome due to aflatoxin B1 (AFB1) by probiotics remains unclear. This study investigated the alterations of gut microbiota and proteome in AFB1-exposed rats treated with probiotic Lactobacillus casei Shirota (Lcs). Forty male Sprague Dawley rats were randomly divided into five groups (n = 8) comprised control, AFB1, AFB1+activated charcoal, AFB1+Lcs, and Lcs groups. The rats were subjected to different treatments via oral gavage for four weeks. Urine and serum were collected for the measurement of AFB1 biomarkers and organs were harvested for histological analysis. Metagenomic sequencing was performed on fecal samples to profile gut microbiota. Besides, AFB1 most affected organ i.e. jejunum was subjected to proteomic analysis. The results indicated that Lcs intervention significantly reduced AFB1 biomarkers. H&E-stained intestine showed Lcs alleviated AFB1-induced inflammation and abnormal cell growth, particularly at the jejunum. Although AFB1 increased potentially pathogenic bacteria and reduced beneficial bacteria abundance in feces, the microbiota composition was normalized with Lcs treatment. The gut proteome analysis of the jejunum sample showed several pathways of AFB1 toxicity, wherein Lcs treatment demonstrated its protective effect. It is concluded that metagenomic and proteomic approaches are useful tools to understand AFB1-Lcs interaction and detoxification mechanism in the gut.

Dietary Resveratrol Alleviates AFB1-Induced Ileum Damage in Ducks via the Nrf2 and NF-κB/NLRP3 Signaling Pathways and CYP1A1/2 Expressions

The aim of this study was to explore the mechanism underlying the protective effects of resveratrol against Aflatoxin B1-induced ileum injury in ducks. A corn–soybean meal-basal diet and two test diets (500 mg/kg resveratrol +0.2 mg Aflatoxin B1/kg, 0.2 mg AFB1/kg) were used in a 10-wk design trial (n = 15 ducks/group). These results showed that the toxicity of Aflatoxin B1 significantly reduced the antioxidant capacity of duck ileum and induced inflammation, oxidative stress, mitochondrial dysfunction and DNA damage in ducks. The expression of genes, including CYP1A2, CYP2A6, and CYP3A4, at the mRNA level was significantly upregulated (p &lt; 0.05) by AFB1. The level of Nrf2 was suppressed (p &lt; 0.05) and the mRNA and protein level of NF-κB was activated (p &lt; 0.05) in the AFB1 group. However, supplementation with 500 mg/kg dietary resveratrol in Aflatoxin B1-induced ducks significantly ameliorated these alterations and decreased the mRNA expression of CYP1A1 and CYP1A2 (p &lt; 0.05) and the production of AFB1-DNA adducts (p &lt; 0.05). The results proved that resveratrol alleviated ileum injury induced by AFB1, decreased the production of AFB1-DNA adducts by downregulating the expression of CYP1A1 and CYP1A2, and reduced DNA damage and oxidative stress via the Nrf2/ Keap1 and NF-κB/NLRP3 signaling pathways.

The Efficacy of a Smectite-Based Mycotoxin Binder in Reducing Aflatoxin B1 Toxicity on Performance, Health and Histopathology of Broiler Chickens.

The aim of the experiment was to investigate the efficacy of a smectite-based clay binder (Toxo-MX) in reducing the toxicological effects of aflatoxin B1 (AFB1) in commercial broiler chickens. A total of 450 one-day old male broiler chickens were randomly allocated into three treatment groups with ten replicates of 15 birds each in a 42-day feeding experiment. The dietary treatments included a negative control (NC, a basal diet with no AFB1 and binder), a positive control (PC, a basal diet contaminated with 500 ppb of AFB1) and a smectite-based mycotoxin binder(Toxo-MX, PC with smectite clay binder). AFB1 challenge resulted in 14 to 24% depression in growth performance, elevated levels of aspartate aminotransferase (AST), and gamma-glutamyl transferase (GGT), organ enlargement and immuno-suppression.As compared to PC, feeding of Toxo-MX improved the final weight (15%; p < 0.0001), average daily gain (ADG) (15%; p < 0.001) and feed efficiency of broilers (13%; p < 0.0003) but did not have any effects on liver enzyme activities. Supplementation of smectite claysignificantly increased serum globulin levels and reduced the weight of the liver (p < 0.05) as compared to AFB1-fed broiler chickens. The severity of lesions (inflammatory and degenerative changes) observed in the liver, kidney, heart, pancreas, and lymphoid organs in PC birds was reduced by feeding smectite clay. The immuno-suppression caused by AFB1 was moderately ameliorated in Toxo-MX groupby stimulating the production of antibodies against IBD at day 42 (p < 0.05). In conclusion, dietary supplementation of a smectite-based mycotoxin binder to the diet containing AFB1 improved growth performance, reduced toxicological effects in liver and improved humoral immune response in broilers, suggesting its protective effect against aflatoxicosis.

Carbon Dots/α-Fe2O3-Fe3O4 nanocomposite: Efficient synthesis and application as a novel electrochemical aptasensor for the ultrasensitive determination of aflatoxin B1

Developing an effective method for the detection of aflatoxin B1 (AFB1) remains an arduous task due to the high toxicity of AFB1 to a health concern. In this study, a sensitive and reliable electrochemical aptasensor based on carbon dots/α-Fe2O3-Fe3O4 nanocomposite (CDs/α-Fe2O3-Fe3O4) is constructed for the determination of AFB1. The CDs have good electrical conductivity and large specific surface areas to improve the aptasensor’s sensitivity. The α-Fe2O3-Fe3O4 can not only improve the catalytic performance of the aptasensor but also have magnetism, which can realize the recovery of CDs/α-Fe2O3-Fe3O4 to avoid material waste and environmental pollution. This electrochemical aptasensor can achieve a good linear (0.001–100.0 nM) and excellent detection limit (0.5 pM) for the determination of AFB1. In addition, the aptasensor was also applied to determine AFB1 in beer, rice, and peanuts, all results were in good agreement with HPLC, indicating that the electrochemical aptasensor has a broad application prospect.

(Invited) Cold Plasma As a Tool for a Removal of the Harmful Contaminants

Cold atmospheric pressure plasmas (CAP) represent an emerging technology that shows an enormous potential in removal of different hazardous contaminants relevant in the fields such as food and environmental technology and medicine [1]. In principle, plasma is the fourth state of matter; it can be created by applying the gas into a strong electrical field, which leads to the ionisation, dissociation and excitation of gaseous molecules. CAP generated using only air and electricity is a strongly non-equilibrium system, exhibiting striking physical and chemical characteristics; electron temperatures exceed 30,000 K, while the temperature of neutrals remains close to room temperature [2]. As a mixture of highly reactive particles, it represents a very promising, low-cost and eco-friendly method for decontamination with negligible effect on the treated substrate.To demonstrate its potential, we present a case study based on decontamination of mycotoxins using surface barrier discharge (SBD) CAP system, working at ambient air. Mycotoxins, the secondary metabolites produced by filamentous fungi, are toxic compounds that are found on over 70 % of global food and feed crop. Although many preventive measures are carried out, the trend of mycotoxin contamination is growing and affecting the health of more than a half of the human population [3]. Therefore, the development of a new and more effective method is necessary.We demonstrated that CAP was able to reach more than 90 % reduction of the treated mycotoxins. In comparison to commercially used UV irradiation, decontamination rate of CAP was a magnitude higher [4]. Furthermore, a detailed analysis based on CAP treatment of most potent mycotoxin aflatoxin B1 (AFB1) was performed, revealing that CAP induced degradation started at C8-C9 site of AFB1 molecule, which is also responsible for its toxicity. Further degradation led to the formation of 4 most important degradation products. Toxicity tests demonstrated that CAP induced complete removal of AFB1 toxicity [5]. According to these encouraging results, it can be concluded that CAP technology can be applied as a new efficient tool for decontamination of mycotoxins and also other emerging contaminants such as pesticides, pharmaceuticals, bisphenols etc.[1] M. Moreau, N. Orange, J.-L. Brisset, Ozone: Science and Engineering 2005, 27, 469-473.[2] A. Dickenson, Y. Morabit, M. I. Hasan, J. L. Walsh, Scientific Reports 2017, 7, 14003.[3] M. Eskola, G. Kos, C. T. Elliott, J. Hajšlová, S. Mayar, R. Krska, Critical Reviews in Food Science and Nutrition 2019, 1-17.[4] N. Hojnik, M. Modic, G. Tavčar-Kalcher, J. Babič, J. L. Walsh, U. Cvelbar, Toxins 2019, 11, 219.[5] N. Hojnik, M. Modic, J. L. Walsh, D. Žigon, U. Javornik, J. Plavec, B. Žegura, M. Filipič, U. Cvelbar, Journal of Hazardous Materials 2021, 403, 123593.

Aflatoxin B1 Toxicity in Zebrafish Larva (Danio rerio): Protective Role of Hericium erinaceus.

Aflatoxin B1 (AFB1), a secondary metabolite produced by fungi of the genus Aspergillus, has been found among various foods as well as in fish feed. However, the effects of AFB1 on fish development and its associated toxic mechanism are still unclear. In the present study, we confirmed the morphological alterations in zebrafish embryos and larvae after exposure to different AFB1 doses as well as the oxidative stress pathway that is involved. Furthermore, we evaluated the potentially protective effect of Hericium erinaceus extract, one of the most characterized fungal extracts, with a focus on the nervous system. Treating the embryos 6 h post fertilization (hpf) with AFB1 at 50 and 100 ng/mL significantly increased oxidative stress and induced malformations in six-day post-fertilization (dpf) zebrafish larvae. The evaluation of lethal and developmental endpoints such as hatching, edema, malformations, abnormal heart rate, and survival rate were evaluated after 96 h of exposure. Hericium inhibited the morphological alterations of the larvae as well as the increase in oxidative stress and lipid peroxidation. In conclusion: our study suggests that a natural extract such as Hericium may play a partial role in promoting antioxidant defense systems and may contrast lipid peroxidation in fish development by counteracting the AFB1 toxicity mechanism.

Selenium nanoparticles are more efficient than sodium selenite in reducing the toxicity of aflatoxin B1 in Japanese quail.

BackgroundDietary selenium (Se), as an antioxidant element, plays a protective role in aflatoxin B1 (AFB1) toxicosis in poultry.ObjectivesTo compare the effects of sodium selenite (SS) and Se nanoparticles (SeNPs) against AFB1‐induced toxicity on growth performance, carcass traits, immune response, antioxidant status and serum lipid concentrations in Japanese broiler quails.MethodsA total of 540 quails were divided into six treatments, each with six replicates and 15 birds per replicate at 24 days of age and reared for 21 days. Treatments included: (1) a basal diet without Se and AFB1 (negative control; NC); (2) NC + 1.0 mg/kg AFB1 (positive control; PC); (3) PC + 0.2 mg/kg Se as SS; (4) PC + 0.5 mg/kg Se as SS; (5) PC + 0.2 mg/kg Se as SeNPs; and (6) PC + 0.5 mg/kg Se as SeNPs.ResultsTreatment with PC diet decreased feed intake and body weight gain and increased feed conversion ratio than the NC diet. The PC diet also atrophied the lymphoid organs and depressed antibody responses against Newcastle disease and avian influenza viruses and sheep red blood cell. Moreover, quails treated with PC diet appeared to have lower serum glutathione peroxidase and thioredoxin reductase activities and disturbed serum lipids than those receiving the NC diet. Dietary Se attenuated these detrimental effects, but failed to completely eliminate them. Additionally, SeNPs performed better than SS in improving thioredoxin reductase activity and antibody titer against sheep red blood cell.ConclusionsDiet supplementation with SeNPs to provide 0.5 mg/kg of Se is recommended to reduce the AFB1 toxicosis in broiler quails.

Effects of bile acids on aflatoxin B1 bioaccumulation, detoxification system, and growth performance of Pacific white shrimp

The potential of bile acids (BAs) to reduce aflatoxin B1 (AFB1) residues and toxicity in Litopenaeus vannamei was evaluated. Both juveniles and subadults were treated with 0, 0.05, 0.15 and 0.25 g/kg BAs for 60 days followed by 10-d AFB1 exposure (2000 μg/kg), and fifteen shrimp (five shrimp were pooled into one sample, n = 3) from each treatment were collected at five time points (30, 60, 63, 66 and 70 d). All parameters were determined using accepted and standard methods with acceptable accuracy (recovery) of 90–110%. Results demonstrated that BAs reduced the AFB1 residues in shrimp (limit of detection: 0.01 μg/L, relative standard deviation < 10% and recovery: 92.1–96.8%). BAs increased the detoxification of AFB1 and decreased the levels of oxidative stress products by increasing Phase II and antioxidant systems, avoiding AFB1-induced deterioration of shrimp meat and health risks to human. The confidence level was 95%.