Response of the hepatic transcriptome to aflatoxin B1 in ducklings

AP-1 and SP1 trans-activate the expression of hepatic CYP1A1 and CYP2A6 in the bioactivation of AFB1 in chicken

Dietary exposure to aflatoxin B1 (AFB1) is harmful to the health and performance of domestic animals. The hepatic cytochrome P450s (CYPs), CYP1A1 and CYP2A6, are the primary enzymes responsible for the bioactivation of AFB1 to the highly toxic exo-AFB1-8,9-epoxide (AFBO) in chicks. However, the transcriptional regulation mechanism of these CYP genes in the liver of chicks in AFB1 metabolism remains unknown. Dual-luciferase reporter assay, bioinformatics and site-directed mutation results indicated that specificity protein 1 (SP1) and activator protein-1 (AP-1) motifs were located in the core region -1,063/-948, -606/-541 of the CYP1A1 promoter as well as -636/-595, -503/-462, -147/-1 of the CYP2A6 promoter. Furthermore, overexpression and decoy oligodeoxynucleotide technologies demonstrated that SP1 and AP-1 were pivotal transcriptional activators regulating the promoter activity of CYP1A1 and CYP2A6. Moreover, bioactivation of AFB1 to AFBO could be increased by upregulation of CYP1A1 and CYP2A6 expression, which was trans-activated owing to the upregulalion of AP-1, rather than SP1, stimulated by AFB1-induced reactive oxygen species. Additionally, nano-selenium could reduce ROS, downregulate AP-1 expression and then decrease the expression of CYP1A1 and CYP2A6, thus alleviating the toxicity of AFB1. In conclusion, AP-1 and SP1 played important roles in the transactivation of CYP1A1 and CYP2A6 expression and further bioactivated AFB1 to AFBO in chicken liver, which could provide novel targets for the remediation of aflatoxicosis in chicks.

Seed-borne bacterial synthetic community resists seed pathogenic fungi and promotes plant growth

AIMS

In this study, the control effects of synthetic microbial communities composed of peanut seed bacteria against seed aflatoxin contamination caused by Aspergillus flavus and root rot by Fusarium oxysporum were evaluated.

METHODS AND RESULTS

Potentially conserved microbial synthetic communities (C), growth-promoting synthetic communities (S), and combined synthetic communities (CS) of peanut seeds were constructed after 16S rRNA Illumina sequencing, strain isolation, and measurement of plant growth promotion indicators. Three synthetic communities showed resistance to root rot and CS had the best effect after inoculating into peanut seedlings. This was achieved by increased defense enzyme activity and activated salicylic acid (SA)-related, systematically induced resistance in peanuts. In addition, CS also inhibited the reproduction of A. flavus on peanut seeds and the production of aflatoxin. These effects are related to bacterial degradation of toxins and destruction of mycelia.

CONCLUSIONS

Inoculation with a synthetic community composed of seed bacteria can help host peanuts resist the invasion of seeds by A. flavus and seedlings by F. oxysporum and promote the growth of peanut seedlings.

Aflatoxin B1-induced early developmental hepatotoxicity in larvae zebrafish

Aflatoxin B1 (AFB1) is a ubiquitous mycotoxin that causes oxidative damage in various organs. At present, the research studies on AFB1 are primarily focused on its effects on the terrestrial environment and animals. However, its toxicity mechanism in aquatic environments and aquatic animals has not been largely explored. Thus, in this study, zebrafish was used as a model to study the toxicity mechanism of AFB1 on the liver of developing larvae. The results showed that AFB1 exposure inhibited liver development and promoted fat accumulation in the liver. Transcriptome sequencing analysis showed that AFB1 affected liver redox metabolism and oxidoreductase activity. KEGG analysis showed that AFB1 inhibited the expression of gsto1, gpx4a, mgst3a, and idh1 in the glutathione metabolizing enzyme gene pathway, resulting in hepatic oxidative stress. At the same time, AFB1 also inhibited the expression of acox1, acsl1b, pparα, fabp2, and cpt1 genes in peroxidase and PPAR metabolic pathways, inducing hepatic steatosis and lipid droplet accumulation. Antioxidant N-Acetyl-l-cysteine (NAC) preconditioning up-regulated gsto1, gpx4a and idh1 genes, and improved the AFB1-induced lipid droplet accumulation in the liver. In summary, AFB1 induced hepatic oxidative stress and steatosis, resulting in abnormal liver fat metabolism and accumulation of cellular lipid droplets. NAC could be used as a potential preventative drug to improve AFB1-induced fat accumulation.

Promising role of Lawsonia inermis L. leaves extract and its nano-formulation as double treatment against aflatoxin toxicity in ulcerated-rats: Application in milk beverage

Aflatoxins are an unavoidable contaminant of foods. The current work aimed to study the ameliorating effect of Lawsonia inermis L. extract and its nano-formulation versus aflatoxin ingestion in ulcerative rats. Lawsonia inermis L. bioactivity was evaluated by both antioxidant & antimicrobial assays. The nanoparticles characterization measurements were evaluated. Different parameters in the fortified milk beverage were assessed. Seventy two Sprague-Dawley male rats were randomized into 12 groups (6 rats/group) where peptic ulcer was induced with a single aspirin dose (500 mg/kg BW) orally. The nutritional and biochemical parameters were evaluated. The results showed that antioxidant activity and total phenolic content increased with increasing nano-formulation ratio. A remarkable improvements in all the treated groups, either for ulcer alone or for aflatoxin exposed ulcerative groups in normal and nano-formulation. Conclusively, Lawsonia inermis L. & its nano-formulation could act as dual therapy for ulcer treatment and the hazardous effects of aflatoxin exposure.

ZnO-NPs alleviate aflatoxin B1-induced hepatoxicity in ducklings by promoting hepatic metallothionein expression

Aflatoxin B₁ (AFB₁) is a mycotoxin widely present in animal feed and human food, posing a serious threat to animal and human health. This study was aim to illustrate the mechanism of the protective role of MT against AFB₁-induced hepatotoxicity, as well as to explore the feasibility of enhancing the tolerance of poultry to AFB₁ by upregulating the expression of hepatic MT. After being exposed to AFB₁ (50 ng/kg) primary duckling hepatocytes, the cell viability, the antioxidant index (SOD and GPx) and the mRNA levels of MT downstream genes (PTGR, p53, TrxR, AR and Bcl-2) significantly (p < 0.05) decreased, while the intracellular formation of (AFBO)-DNA adduct content, apoptosis, and MDA content significantly (p < 0.05) increased. Interestingly, overexpression of MT in primary duckling hepatocytes markedly (p < 0.05) reversed the detrimental impact of AFB₁ and increased the expression of MT downstream genes. HepG2 cells were applied to study the mechanism how MT works to relieve the hepatic toxicity of AFB₁. The ZnO-NPs (20 μg/mL) + AFB₁ (20 μg/mL) group significantly (p < 0.05) increased the cell viability, the expression of NRF2, NQO1 and SOD, and expression of MT and MTF-1, as well as significantly (p < 0.05) decreased LDH, ROS and apoptotic rate, comparing with the AFB₁ group. While joint treatment with AFB₁ and ZnO-NPs, the hepatic toxicity exerted by AFB₁ alone was reversed, along with the translocation of MTF-1 from the cytoplasm to the nucleus and upregulated its expression. Duckling trails were further carried out. A total number of 96 1-day-old healthy Cherry Valley commercial ducklings were randomly allocated according to a 2 by 2 factorial arrangement of treatments with the main factors including oral administration of AFB₁ (0 vs. 40 μg/kg) and dietary supplementation of ZnO-NPs (0 vs. 60 mg/kg) for 7 days. It showed that AFB₁ exposure caused body weight loss (p < 0.05), impaired liver structure and failure in hepatic function (activity of ALT, AST and concentration of TP and GLU) (p < 0.05), and decreases in antioxidant capacity(activity of SOD, CAT and concentration of GSH) (p < 0.05), along with the decrease in hepatic concentration of Zn, increase in expression of apoptosis-related genes and protein CAS3 and mRNA Bcl-2 expression (p < 0.05), and suppressed mRNA levels of antioxidant-related genes MT, SOD1, NRF2, and NQO1 (p < 0.05). In accordance with the cell test, dietary supplementation with ZnO-NPs mitigated the toxicity exerted by AFB₁. In conclusion, ZnO-NPs has the protective effects against AFB₁-induced hepatocyte injury by activating the expression of MTF-1 and the ectopic induction of MT expression, providing detailed information on the detoxification ability of MT on AFB₁.

May phytophenolics alleviate aflatoxins-induced health challenges? A holistic insight on current landscape and future prospects

The future GCC-connected environmental risk factors expedited the progression of nCDs. Indeed, the emergence of AFs is becoming a global food security concern. AFs are lethal carcinogenic mycotoxins, causing damage to the liver, kidney, and gastrointestinal organs. Long-term exposure to AFs leads to liver cancer. Almost a variety of food commodities, crops, spices, herbaceous materials, nuts, and processed foods can be contaminated with AFs. In this regard, the primary sections of this review aim to cover influencing factors in the occurrence of AFs, the role of AFs in progression of nCDs, links between GCC/nCDs and exposure to AFs, frequency of AFs-based academic investigations, and world distribution of AFs. Next, the current trends in the application of PPs to alleviate AFs toxicity are discussed. Nearly, more than 20,000 published records indexed in scientific databases have been screened to find recent trends on AFs and application of PPs in AFs therapy. Accordingly, shifts in world climate, improper infrastructures for production/storage of food commodities, inconsistency of global polices on AFs permissible concentration in food/feed, and lack of the public awareness are accounting for a considerable proportion of AFs damages. AFs exhibited their toxic effects by triggering the progression of inflammation and oxidative/nitrosative stress, in turn, leading to the onset of nCDs. PPs could decrease AFs-associated oxidative stress, genotoxic, mutagenic, and carcinogenic effects by improving cellular antioxidant balance, regulation of signaling pathways, alleviating inflammatory responses, and modification of gene expression profile in a dose/time-reliant fashion. The administration of PPs alone displayed lower biological properties compared to co-treatment of these metabolites with AFs. This issue might highlight the therapeutic application of PPs than their preventative content. Flavonoids such as quercetin and oxidized tea phenolics, curcumin and resveratrol were the most studied anti-AFs PPs. Our literature review clearly disclosed that considering PPs in antioxidant therapies to alleviate complications of AFs requires improvement in their bioavailability, pharmacokinetics, tissue clearance, and off-target mode of action. Due to the emergencies in the elimination of AFs in food/feedstuffs, further large-scale clinical assessment of PPs to decrease the consequences of AFs is highly required.

Aflatoxin B1 Toxicity and Protective Effects of Curcumin: Molecular Mechanisms and Clinical Implications

One of the most significant classes of mycotoxins, aflatoxins (AFTs), can cause a variety of detrimental outcomes, including cancer, hepatitis, aberrant mutations, and reproductive issues. Among the 21 identified AFTs, aflatoxin B1 (AFB1) is the most harmful to humans and animals. The mechanisms of AFB1-induced toxicity are connected to the generation of excess reactive oxygen species (ROS), upregulation of CYP450 activities, oxidative stress, lipid peroxidation, apoptosis, mitochondrial dysfunction, autophagy, necrosis, and inflammatory response. Several signaling pathways, including p53, PI3K/Akt/mTOR, Nrf2/ARE, NF-κB, NLRP3, MAPKs, and Wnt/β-catenin have been shown to contribute to AFB1-mediated toxic effects in mammalian cells. Curcumin, a natural product with multiple therapeutic activities (e.g., anti-inflammatory, antioxidant, anticancer, and immunoregulation activities), could revise AFB1-induced harmful effects by targeting these pathways. Therefore, the potential therapeutic use of curcumin against AFB1-related side effects and the underlying molecular mechanisms are summarized. This review, in our opinion, advances significant knowledge, sparks larger discussions, and drives additional improvements in the hazardous examination of AFTs and detoxifying the application of curcumin.

Advances in the study of liver microsomes in the in vitro metabolism and toxicity evaluation of foodborne contaminants

Foodborne contaminants are closely related to anthropologic activities and represent an important food safety hazard. The study of metabolic transformation and toxic side effects of foodborne contaminants in the body is important for their safety assessment. Liver microsomes contain a variety of enzymes related to substance metabolism and biotransformation. An in vitro model simulating liver metabolic transformation is associated with a significant advantage in the study of the metabolic transformation mechanisms of contaminants. This review summarizes the recent progress in the application of liver microsomes in metabolic transformation and toxicity evaluation of various foodborne pollutants based on metabolic kinetics, molecular docking and enzyme inhibition studies. The purpose of this review is to distinguish the existing studies involving liver microsomes and provide strategies for their application in the future. Finally, the prospects and challenges of the liver microsomal model are discussed.

Research progress in toxicological effects and mechanism of aflatoxin B1 toxin

Fungal contamination of animal feed can severely affect the health of farm animals, and result in considerable economic losses. Certain filamentous fungi or molds produce toxic secondary metabolites known as mycotoxins, of which aflatoxins (AFTs) are considered the most critical dietary risk factor for both humans and animals. AFTs are ubiquitous in the environment, soil, and food crops, and aflatoxin B₁(AFB₁) has been identified by the World Health Organization (WHO) as one of the most potent natural group 1A carcinogen. We reviewed the literature on the toxic effects of AFB₁ in humans and animals along with its toxicokinetic properties. The damage induced by AFB₁ in cells and tissues is mainly achieved through cell cycle arrest and inhibition of cell proliferation, and the induction of apoptosis, oxidative stress, endoplasmic reticulum (ER) stress and autophagy. In addition, numerous coding genes and non-coding RNAs have been identified that regulate AFB₁ toxicity. This review is a summary of the current research on the complexity of AFB₁ toxicity, and provides insights into the molecular mechanisms as well as the phenotypic characteristics.

Deepening the Whole Transcriptomics of Bovine Liver Cells Exposed to AFB1: A Spotlight on Toll-like Receptor 2

Aflatoxin B1 (AFB1) is a food contaminant metabolized mostly in the liver and leading to hepatic damage. Livestock species are differently susceptible to AFB1, but the underlying mechanisms of toxicity have not yet been fully investigated, especially in ruminants. Thus, the aim of the present study was to better characterize the molecular mechanism by which AFB1 exerts hepatotoxicity in cattle. The bovine fetal hepatocyte cell line (BFH12) was exposed for 48 h to three different AFB1 concentrations (0.9 µM, 1.8 µM and 3.6 µM). Whole-transcriptomic changes were measured by RNA-seq analysis, showing significant differences in the expression of genes mainly involved in inflammatory response, oxidative stress, drug metabolism, apoptosis and cancer. As a confirmatory step, post-translational investigations on genes of interest were implemented. Cell death associated with necrosis rather than apoptosis events was noted. As far as the toxicity mechanism is concerned, a molecular pathway linking inflammatory response and oxidative stress was postulated. Toll-Like Receptor 2 (TLR2) activation, consequent to AFB1 exposure, triggers an intracellular signaling cascade involving a kinase (p38β MAPK), which in turn allows the nuclear translocation of the activator protein-1 (AP-1) and NF-κB, finally leading to the release of pro-inflammatory cytokines. Furthermore, a p38β MAPK negative role in cytoprotective genes regulation was postulated. Overall, our investigations improved the actual knowledge on the molecular effects of this worldwide relevant natural toxin in cattle.

Transcriptomics and transmission ultrastructural examination reveals the nephrotoxicity of cadmium in laying hens

The objective of this study was to reveal the effects of cadmium (Cd) on ultrastructural changes, oxidative stress, and transcriptome expression in the kidneys of laying hens. Seventy-two healthy Hy-Line brown laying hens at 41 weeks old were randomly allocated to four treatment groups with six replicates. The control group received a basal diet without additional Cd incorporation, and the other three treatment groups received diets supplemented with 15, 30, or 60 mg Cd /kg of feed. After 6 weeks of exposure, the results show that administration of 60 mg/kg Cd significantly reduced (P < 0.05) eggshell thickness. With an increase in the Cd concentration in feed, the concentrations of renal Zn and Fe also had changed. Renal histopathology and ultrastructure also showed aggravated damage to glomeruli and renal tubules and the deformation of nuclei and mitochondria in all Cd treatment groups. With an increase in Cd in feed, the activity of glutathione peroxide (GPX) and catalase (CAT) was significantly reduced (P < 0.05), while the activity of total antioxidant capacity (T -AOC) was decreased (P < 0.05) only in the 60 mg/kg Cd group. RNA-seq analysis revealed that 410 genes displayed differential expression (≥ 1.5-fold) in the 60 mg/kg supplementation group, compared to the control group. GO and KEGG pathway analysis results showed that Cd affected many genes involved in mitochondria and ion transport. In conclusion, this study elaborates the mechanisms underlying renal toxicity caused by Cd, which might provide target candidate genes for alleviating Cd poisoning in laying hens.

Hepatoprotective Role of Clay and Nano Clay for Alleviating Aflatoxin Toxicity in Male Rats

&lt;b&gt;Background and Objective:&lt;/b&gt; Aflatoxin formed by &lt;i&gt;Aspergillus&lt;/i&gt; sp. causes acute hepatotoxicity by DNA damage, gene expression disruption and induced liver carcinoma in humans and laboratory animals. The objectives of this research were to evaluate the protective role of both clay and nano clay as adsorbents to inhibit the side effect of Aflatoxin (AF) by measures the common biological assay of aflatoxicosis in rats along with hepatic gene expression and comet assay. &lt;b&gt;Materials and Methods:&lt;/b&gt; Six weeks old male albino rats were distributed into 6 groups with 10 rats per group fed on, Group 1: Basal diet, Group 2: Basal diet with clay (5 g kg&lt;sup&gt;&lt;/sup&gt;&lt;sup&gt;1&lt;/sup&gt; diet), Group 3: Basal diet with nano clay (5 g kg&lt;sup&gt;&lt;/sup&gt;&lt;sup&gt;1&lt;/sup&gt; diet), Group 4: AF-contaminated diet (1 mg kg&lt;sup&gt;&lt;/sup&gt;&lt;sup&gt;1&lt;/sup&gt; diet), Group 5: AF with clay, Group 6: AF with nano clay. &lt;b&gt;Results:&lt;/b&gt; AF induced a noticeable increase in the liver function parameters, accompanied by a significant decrease in antioxidant enzyme activities and significant histological alterations in liver tissues. The obtained qPCR results showed a significant up regulation in the expression of Cyp3A6, HO-1, TNFα and NFKB genes in the liver of rats treated with aflatoxin. In contrast, there is a significant down regulation in the expression levels of the Glut2 gene in liver rats treated with aflatoxin. Also, aflatoxin induced a significant increase in DNA damage. Clay and nano clay succeeded in ameliorating the toxic effects of aflatoxin. &lt;b&gt;Conclusion:&lt;/b&gt; The results indicated the effective role of clay and nano clay in alleviating aflatoxin and reduce its harmful effects.

Omics in the detection and identification of biosynthetic pathways related to mycotoxin synthesis

Mycotoxins are secondary metabolites that are known to be toxic to humans and animals. On the other hand, some mycotoxins and their analogues possess antioxidant as well as antitumor properties, which could be relevant in the fields of pharmaceutical analysis and food research. Omics techniques are a group of analytical tools applied in the biological sciences in order to study genes (genomics), mRNA (transcriptomics), proteins (proteomics), and metabolites (metabolomics). Omics have become a vital tool in the field of mycotoxins, especially contributing to the identification of biomarkers with potential use for the detection of mycotoxigenic species and the gathering of information about the biosynthetic pathways of mycotoxins in different environments. This approach has provided tools for the development of prevention strategies and control measures for different mycotoxins. Additionally, research has revealed important information about the impact of global warming and climate change on the prevalence of mycotoxin issues in society. In the context of foodomics, the aim is to apply omics techniques in order to ensure food safety. The objective of the present review is to determine the state of the art regarding the development of analytical techniques based on omics in the identification of biosynthetic pathways related to mycotoxin synthesis.

Ferulic acid prevents aflatoxin B1-induced liver injury in rats via inhibiting cytochrome P450 enzyme, activating Nrf2/GST pathway and regulating mitochondrial pathway

Aflatoxin B1 (AFB1) causes oxidative stress and hepatocyte apoptosis through its epoxidized metabolite AFBO, which is catalyzed by CYP450 enzymes. Ferulic acid (FA) is a phenolic acid commonly found in plants and is known for its antioxidant capacity. However, the role of FA in AFB1-induced liver injury is still elusive. In this study, rats were exposed to AFB1 and simultaneously treated with FA for 30 days. The results showed that I) FA alleviated the histopathological changes induced by AFB1, inhibited the elevation of serological indexes induced by AFB1, and reduced the production of AFBO in liver. II) AFB1-induced increase in CYP450 expression was significantly reduced by FA. The molecular docking results of FA and CYP2A6 showed high fitness score and interaction. III) FA obviously inhibited the production of MDA, and significantly activated the Nrf2/GST pathway and antioxidant enzymes (SOD and GST). IV) AFB1-induced hepatocyte apoptosis, the high expression of p53, bax, cyt-c, caspase-9, caspase-3, and the low expression of bcl-2 were all restored by FA. It has been suggested from these results that FA proved effective against AFB1-induced liver damage in rats via inhibiting CYP450 enzyme, promoting antioxidant pathway Nrf2/GST, activating antioxidant enzymes (SOD and GST), and regulating the mitochondrial pathway.

Mitigation of Aflatoxin B1 Hepatoxicity by Dietary Hedyotis diffusa Is Associated with Activation of NRF2/ARE Signaling in Chicks

The objective of this study was to explore the mechanism of Hedyotis diffusa (HD) in mediating the detoxification of aflatoxin B₁ (AFB₁)-induced hepatic injury in chicks. A total of 144 one-day-old male broilers (Cobb 500) were randomly assigned to four treatment groups (n = 6 cages/diet, 6 chicks/cage). After three days of acclimation, the broilers were fed either a control diet (Control), Control plus 0.5 mg/kg of AFB₁, or Control plus 0.5 mg/kg AFB₁ with 500 or 1000 mg/kg HD for two weeks. Both serum and liver were collected at the end of the feeding trial for biochemistry, histology, and NF-E2-related nuclear factor 2 (NRF2)/antioxidant response element (ARE) signaling analysis. Compared with Control, the AFB₁ treatment caused liver injury and decreased (p < 0.05) body weight gain, feed intake, feed conversion ratio, and serum albumin and total protein by 6.2–20.7%. AFB₁ also induced swelling, necrosis, and severe vacuolar degeneration in chicks’ livers. Notably, HD supplementation at 500 and 1000 mg/kg mitigated (p < 0.05) the alterations induced by AFB₁. HD supplementation alleviated (p < 0.05) AFB₁-induced impairment in hepatic glutathione peroxidase activity, protein carbonyl, and exo-AFB₁-8,9-epoxide (AFBO)–DNA concentrations by 57.7–100% and increased (p < 0.05) the activities of superoxide dismutase and catalase by 23.1–40.9% more than those of AFB₁ treatment alone. Furthermore, HD supplementation at the two doses upregulated (p < 0.05) NRF2, NAD(P)H: quinone oxidoreductase-1, heme oxygenase-1, glutathione cysteine ligase catalytic subunit, and glutathione-S transferase A2 and A3 in livers relative to the AFB₁ group by 0.99–3.4-fold. Overall, dietary supplementation of HD at a high dose displayed better protection effects against aflatoxicosis. In conclusion, a dietary HD supplementation at 500 and 1000 mg/kg protected broilers from AFB₁-induced hepatotoxicity, potentially due to the activation of NRF2/ARE signaling in the chicks.

The Mechanism Underlying the Extreme Sensitivity of Duck to Aflatoxin B1

Most metabolites of aflatoxin B1 (AFB1), especially exo-AFB1-8,9-epoxide (AFBO), can induce the production of reactive oxygen species (ROS) to vary degrees, causing oxidative stress and liver damage, and ultimately induce liver cancer in humans and animals. Duck is one of the most sensitive animals to AFB1, and severe economic losses are caused by duck AFB1 poisoning every year, but the exact mechanism of this high sensitivity is still unclear. This review highlights significant advances in our understanding of the AFB1 metabolic activation, like cytochrome P450s (CYPs), and AFB1 metabolic detoxification, like glutathione S-transferases (GSTs) in poultry. In addition, AFB1 may have other metabolic pathways in poultry, such as the mutual conversion of AFB1 and aflatoxicol (AFL) and the process of AFBO to produce AFB1-8,9-dihydrodiol (AFB1-dhd) and further metabolize it into detoxification substances. This review also summarized some exogenous regulatory substances that can alleviate AFB1-induced oxidative stress.

Aflatoxicosis in Pekin duckling and the effects of treatments with lycopene and silymarin

Background and Aim:

Aflatoxins (AFs) are potent toxic metabolites produced from Aspergillus species. Whose existence in poultry ration leads to drastic economic losses, notably in duck, as the most susceptible poultry species. This study aimed to determine tissue residues of AFs, alterations in selected clinical chemistry variables in serum, mainly during the exposure period, and lycopene and silymarin’s possible roles as herbal treatments against aflatoxicosis in Pekin duckling.

Materials and Methods:

The study used one hundred and twenty one-day-old Pekin ducklings and classified them into four groups comprising 30 ducklings in each group. The control group (G1) ducklings were fed a mycotoxin-free ration, and G2 received a naturally contaminated ration with 30 ppb of AFs. G3 and G4 consumed contaminated rations with AFs with 30 ppb for 2 weeks and were treated with lycopene 100 mg/kg or silymarin 600 mg/kg/food, respectively, for 10 days. Serum activities of alanine transaminase and alkaline phosphatase (ALP), glutamyl transferase, ALP, total protein and albumin creatinine and uric acid concentrations, oxidant/antioxidant parameters (malondialdehyde [MDA], total antioxidant capacity (TAC), glutathione S-transferase (GST), and catalase [CAT]), and hepatic AFs residue were determined. Lycopene and silymarin were used for the treatment of aflatoxicosis for another 10 days.

Results:

Hepatic and kidney parameters were elevated in the AFs intoxicated group and reduced in the lycopene- and silymarin-treated groups. They had elevated MDA and AFs residues with decreased antioxidant parameters (TAC, GST, and CAT) in the AFs group. At the same time, treatment with lycopene or silymarin had reversed the action of AFs on MDA, elevated the hepatic residue, and improved antioxidant activity.

Conclusion:

Lycopene and silymarin, with their potent antioxidant activity, can be used to reverse the harmful effects of AFs on hepatic and kidney tissue.

Toxicological and physiological effects of successive exposure to ochratoxin A at food regulatory limits

Ochratoxin A (OTA), a potent mycotoxin, is a common contaminant of agro-products, which seriously threatens food safety. The OTA regulatory limits vary from different countries/regions. However, little is known about the toxicological effects of successive exposure to regulatory levels of OTA. In this study, feedstuffs contaminated with 0.5-20 μg kg^-1 OTA were evaluated in Sprague-Dawley (SD) rats. During the study, poisoning-associated behaviors, and significant differences of body weight and food intake, were not observed between OTA-treated rats and control group. However, the renal function indexes of blood urea nitrogen (BUN) and creatinine (CR) increased, and architecture destruction of glomeruli and tubuli was observed from the OTA-treated groups. The apoptosis study indicated that at a concentration of 20 μg kg^-1, OTA modulated apoptosis in renal tissues via the Bcl-2/Bax pathway. The results of this study suggest that exposure to low doses of OTA successively at levels lower than the regulatory limits of certain countries could induce nephrotoxicity, and modulate apoptosis. Therefore, agencies pertaining to food safety should establish strict OTA regulatory limits for food and feedstuff.

Transcriptomics and flow cytometry reveals the cytotoxicity of aflatoxin B1 and aflatoxin M1 in bovine mammary epithelial cells

Aflatoxin is a known mycotoxin that pollutes various grains widely in the environment. Aflatoxin B₁ (AFB₁) and Aflatoxin M₁ (AFM₁) have been shown to induce cytotoxicity in many cells, yet their effects on mammary epithelial cells remain unclear. In this study, we examined the toxicity and the effects of AFB₁ and AFM₁ on bovine mammary epithelial cells (BME cells). The cells were treated with AFB₁ or AFM₁ at a concentration of 0-10 mg/L for 24 or 48 h, followed by cytotoxicity assays, flow cytometry, and transcriptomics. Our results demonstrated that AFB₁ and AFM₁ induced cell proliferation inhibition, apoptosis and cell cycle arrest. However, the level of intracellular reactive oxygen species has no significant difference. The RNA-Seq results also showed that AFB₁ and AFM₁ changed many related gene expressions like apoptosis and oxidative stress, cycle, junction, and signaling pathway. Taken together, AFB₁ and AFM₁ were found to affect cytotoxicity and related gene changes in BME cells. Notably, this study reported that 2 mg/L of AFB₁ and AFM₁ affected the expression of methylation-related genes, and ultimately altered the rate of m⁶A methylation in RNA. It may provide a potential direction for toxins to indirectly regulate gene expression by affecting RNA methylation modification. Our research provides some novel insights and data about AFB₁ and AFM₁ toxicity in BME cells.

Curcumin protects against Aflatoxin B1-induced liver injury in broilers via the modulation of long non-coding RNA expression

Aflatoxin B1 (AFB1) is a potent hepatotoxic and carcinogenic agent. Curcumin possesses potential anti-inflammatory, anti-oxidative and hepatoprotective effects. However, the role of LncRNAs in the protective mechanisms of curcumin against AFB1-induced liver damage is still elusive. Experimental broilers were randomly divided into 1) control group, 2) AFB1 group (1 mg/kg feed), 3) cur + AFB1 group (1 mg/kg AFB1 plus 300 mg/kg curcumin diet) and 4) curcumin group (300 mg/kg curcumin diet). Liver transcriptome analyses and qPCR were performed to identify shifts in genes expression. In addition, histopathological assessment and oxidant status were determined. Dietary AFB1 caused hepatic morphological injury, significantly increased the production of ROS, decreased liver antioxidant enzymes activities and induced inflammation and apoptosis. However, dietary curcumin partially attenuated the abnormal morphological changes, oxidative stress, and apoptosis in liver tissues. Transcriptional profiling results showed that 34 LncRNAs and 717 mRNAs were differentially expressed with AFB1 and curcumin co-treatment in livers of broilers. Analysis of the LncRNA-mRNA network, GO and KEGG enrichment data suggested that oxidative stress, inflammation and apoptosis pathway were crucial in curcumin's alleviating AFB1-induced liver damage. In conclusion, curcumin prevented AFB1-induced oxidative stress, inflammation and apoptosis through LncRNAs. These results provide new insights for unveiling the protective mechanisms of curcumin against AFB1-induced liver damage.

Early Life Exposure to Aflatoxin B1 in Rats: Alterations in Lipids, Hormones, and DNA Methylation among the Offspring

Aflatoxins are toxic compounds produced by molds of the Aspergillus species that contaminate food primarily in tropical countries. The most toxic aflatoxin, aflatoxin B1 (AFB1), is a major cause of hepatocellular carcinoma (HCC) in these countries. In sub-Saharan Africa, aflatoxin contamination is common, and perinatal AFB1 exposure has been linked to the early onset of HCC. Epigenetic programming, including changes to DNA methylation, is one mechanism by which early life exposures can lead to adult disease. This study aims to elucidate whether perinatal AFB1 exposure alters markers of offspring health including weight, lipid, and hormone profiles as well as epigenetic regulation that may later influence cancer risk. Pregnant rats were exposed to two doses of AFB1 (low 0.5 and high 5 mg/kg) before conception, throughout pregnancy, and while weaning and compared to an unexposed group. Offspring from each group were followed to 3 weeks or 3 months of age, and their blood and liver samples were collected. Body weights and lipids were assessed at 3 weeks and 3 months while reproductive, gonadotropic, and thyroid hormones were assessed at 3 months. Prenatal AFB1 (high dose) exposure resulted in significant 16.3%, 31.6%, and 7.5% decreases in weight of the offspring at birth, 3 weeks, and 3 months, respectively. Both doses of exposure altered lipid and hormone profiles. Pyrosequencing was used to quantify percent DNA methylation at tumor suppressor gene Tp53 and growth-regulator H19 in DNA from liver and blood. Results were compared between the control and AFB1 exposure groups in 3-week liver samples and 3-week and 3-month blood samples. Relative to controls, Tp53 DNA methylation in both low- and high-dose exposed rats was significantly decreased in liver samples and increased in the blood (p < 0.05 in linear mixed models). H19 methylation was higher in the liver from low- and high-exposed rats and decreased in 3-month blood samples from the high exposure group (p < 0.05). Further research is warranted to determine whether such hormone, lipid, and epigenetic alterations from AFB1 exposure early in life play a role in the development of early-onset HCC.

Dietary Se deficiency dysregulates metabolic and cell death signaling in aggravating the AFB1 hepatotoxicity of chicks

The objective of this study was to use isobaric tags for relative and absolute quantitation (iTRAQ) proteomic technology to systematically analyze the hepatotoxic mechanism of aflatoxin B₁ (AFB₁) and its prevention by Se in broilers. Four groups of day-old broilers were allocated into a 2 × 2 factorial design trial that fed a Se-deficient based diet (BD) or the BD + 1.0 mg AFB₁/kg, 0.3 mg Se/kg, or 1.0 mg AFB₁/kg plus 0.3 mg Se/kg for 3 wk. Dietary AFB₁ increased serum ALT and decreased total protein and albumin concentrations, and induced hepatic histopathological lesions in Se adequate groups. Notably, Se deficiency exacerbated these AFB₁-induced changes. Furthermore, Se deficiency reduced hepatic glutathione peroxidase but increased thioredoxin reductase and glutathione S-transferase activities and 8-hydroxydeoxyguanosine concentration in AFB₁ administrated groups. Moreover, AFB₁ dysregulated 261 co-differentially expressed proteins (DEPs) in both Se adequate and deficiency diets, and Se deficiency dysregulated 64 DEPs in AFB₁ administrated diets. These DEPs are mainly related to phase I and II metabolizing enzymes, heat shock proteins, DNA repair, fatty acid metabolism and apoptosis. The in vitro study has verified that aldo-keto reductase family1, member10 plays an important role in AFB₁-induced hepatotoxicity and Se-mediated detoxification of AFB₁ in a chicken leghorn male hepatoma cells. Conclusively, this study has analyzed the hepatic proteome response to dietary AFB₁ and Se, and thus shed new light on the mechanisms of hepatotoxicity of AFB₁ and its detoxification by Se in broilers.

Curcumin Mitigates AFB1-Induced Hepatic Toxicity by Triggering Cattle Antioxidant and Anti-inflammatory Pathways: A Whole Transcriptomic In Vitro Study

Aflatoxin B1 (AFB1) toxicity in livestock and human beings is a major economic and health concern. Natural polyphenolic substances with antioxidant properties have proven to be effective in ameliorating AFB1-induced toxicity. Here we assessed the potential anti-AFB1 activity of curcumin (pure curcumin, C, and curcumin from Curcuma longa, CL) in a bovine fetal hepatocyte-derived cell line (BFH12). First, we measured viability of cells exposed to AFB1 in presence or absence of curcumin treatment. Then, we explored all the transcriptional changes occurring in AFB1-exposed cells cotreated with curcumin. Results demonstrated that curcumin is effective in reducing AFB1-induced toxicity, decreasing cells mortality by approximately 30%. C and CL induced similar transcriptional changes in BFH12 exposed to AFB1, yet C treatment resulted in a larger number of significant genes compared to CL. The mitigating effects of curcuminoids towards AFB1 toxicity were mainly related to molecular pathways associated with antioxidant and anti-inflammatory response, cancer, and drug metabolism. Investigating mRNA changes induced by curcumin in cattle BFH12 cells exposed to AFB1 will help us to better characterize possible tools to reduce its consequences in this susceptible and economically important food-producing species.

Functional yogurt aims to protect against the aflatoxin B1 toxicity in rats

Recently, the rise of mycotoxin contamination in food materials was found to be due to several factors, including climatic changes' impact. Therefore, the aim of this study was to provide a novel food product that allows the reduction of aflatoxin impact in animal tissues. Chicory root-extract (CRE) was evaluated for its active components, antioxidant potency, and antimicrobial activity. The CRE was utilized to produce functional yogurt (FY) that was evaluated in-vivo using experimental rats. The CRE showed high antioxidant activity and recorded valuable content of the active components. Results also showed a high antimicrobial effect against toxigenic fungal strains. The results have reflected the efficiency of the FY to suppress aflatoxin impacts in the animal tissues and biochemical parameters of rats-serum. An enhancement was recorded inliver and kidney functions for rats taking FY with the presence of aflatoxin. It was concluded that consumption of the FY assisted in suppression of the oxidative stress in rats-tissues.

Effects of dietary cadmium supplementation on production performance, cadmium residue in eggs, and hepatic damage in laying hens

This study was conducted to investigate the adverse effects of cadmium (Cd) on the production performance, serum biochemistry, liver antioxidant status, histopathology, and egg residue in laying hens. A total of 72 healthy Hy-Line brown laying hens at 40-week-old were randomly assigned to four diets containing 0 (control diet), 15, 30, or 60 mg/kg Cd for 6 weeks. Laying hens exposed to 60 mg/kg Cd had lower egg production rate and worse feed to egg ratio (P < 0.05). Dietary Cd exposure (≥ 15 mg/kg) significantly decreased hepatic glutathione peroxide (GPX) activities, while increasing malondialdehyde (MDA) (P < 0.05). Hepatic histopathology and ultrastructure also showed damage and the symptoms were exacerbated in a dose-dependent manner. The residue of Cd in the yolk was increased with increasing dietary Cd concentration. The mRNA expression levels of mt4L, mt3, sod1, sod2, gpx1, gpx3, and gpx4 in the liver of laying hens exposed to 60 mg Cd/kg feed were significantly decreased (P < 0.05). In conclusion, dietary Cd exposure at ≥ 15 mg/kg induced hepatic damage in laying hens, indicating that the content of Cd in feed must be critically controlled.

Insights into Aflatoxin B1 Toxicity in Cattle: An In Vitro Whole-Transcriptomic Approach

Aflatoxins, and particularly aflatoxin B1 (AFB1), are toxic mycotoxins to humans and farm animal species, resulting in acute and chronic toxicities. At present, AFB1 is still considered a global concern with negative impacts on health, the economy, and social life. In farm animals, exposure to AFB1-contaminated feed may cause several untoward effects, liver damage being one of the most devastating ones. In the present study, we assessed in vitro the transcriptional changes caused by AFB1 in a bovine fetal hepatocyte-derived cell line (BFH12). To boost the cellular response to AFB1, cells were pre-treated with the co-planar PCB 3,3′,4,4′,5-pentachlorobiphenyl (PCB126), a known aryl hydrocarbon receptor agonist. Three experimental groups were considered: cells exposed to the vehicle only, to PCB126, and to PCB126 and AFB1. A total of nine RNA-seq libraries (three replicates/group) were constructed and sequenced. The differential expression analysis showed that PCB126 induced only small transcriptional changes. On the contrary, AFB1 deeply affected the cell transcriptome, the majority of significant genes being associated with cancer, cellular damage and apoptosis, inflammation, bioactivation, and detoxification pathways. Investigating mRNA perturbations induced by AFB1 in cattle BFH12 cells will help us to better understand AFB1 toxicodynamics in this susceptible and economically important food-producing species.

Involvement of hepatic lipid droplets and their associated proteins in the detoxification of aflatoxin B1 in aflatoxin-resistance BALB/C mouse

The highly potent carcinogen, Aflatoxin B₁, induces liver cancer in many animals including humans but some mice strains are highly resistant. This murine resistance is due to a rapid detoxification of AFB₁. Hepatic lipid droplets (LDs) ultimately impact the liver functions but their potential role in AFB₁ detoxification has not been addressed. This study describes the structural and functional impacts on hepatic LDs in BALB/C mice after exposure to 44 (low dose) or 663 (high dose) μg AFB₁/kg of body weight. After 7 days, the liver of AFB₁-dosed mice did not accumulate any detectable AFB₁ or its metabolites and this was associated with a net increase in gene transcripts of the AhR-mediating pathway. Of particular interest, the livers of high-dose mice accumulated many more LDs than those of low-dose mice. This was accompanied with a net increase in transcript levels of LD-associated protein-encoding genes including Plin2, Plin3 and Cideb and an alteration in the LDs lipid profiles that could be likely due to the induction of lipoxygenase and cyclooxygenase genes. Interestingly, our data suggest that hepatic LDs catalyze the in vitro activation of AFB₁ into AFB₁-exo-8,9-epoxide and subsequent hydrolysis of this epoxide into its corresponding dihydrodiol. Finally, transcript levels of CYP1A2, CYP1B1, GSTA3 and EH1 genes were elevated in livers of high-dose mice. These data suggest new roles for hepatic LDs in the trapping and detoxifying of aflatoxins.

The response of glandular gastric transcriptome to T-2 toxin in chicks

This study was conducted to determine the effect of T-2 toxin on the transcriptome of the glandular stomach in chicks using RNA-sequencing (RNA-Seq). Four groups of 1-day-old Cobb male broilers (n = 4 cages/group, 6 chicks/cage) were fed a corn-soybean-based diet (control) and control supplemented with T-2 toxin at 1.0, 3.0, and 6.0 mg/kg, respectively, for 2 weeks. The histological results showed that dietary supplementation of T-2 toxin at 3.0 and 6.0 mg/kg induced glandular gastric injury including serious inflammation, increased inflammatory cells, mucosal edema, and necrosis and desquamation of the epithelial cells in the glandular stomach of chicks. RNA-Seq analysis revealed that there were 671, 1393, and 1394 genes displayed ≥2 (P < 0.05) differential expression in the dietary supplemental T-2 toxin at 1.0, 3.0, and 6.0 mg/kg, respectively, compared with the control group. Notably, 204 differently expressed genes had shared similar changes among these three doses of T-2 toxin. GO and KEGG pathway analysis results showed that many genes involved in oxidation-reduction process, inflammation, wound healing/bleeding, and apoptosis/carcinogenesis were affected by T-2 toxin exposure. In conclusion, this study systematically elucidated toxic mechanisms of T-2 toxin on the glandular stomach, which might provide novel ideas to prevent adverse effects of T-2 toxin in chicks.

Selenium Deficiency Aggravates Aflatoxin B1-Induced Immunotoxicity in Chick Spleen by Regulating 6 Selenoprotein Genes and Redox/Inflammation/Apoptotic Signaling

BACKGROUND

Selenium (Se) plays a protective role in aflatoxin B1 (AFB1)-induced splenic immunotoxicity in chicks.

OBJECTIVE

This study was designed to reveal the underlying mechanism of Se-mediated protection against AFB1-induced splenic injury in broilers.

METHODS

Four groups of 1-d-old Cobb male broilers (n = 5 cages/diet, 6 chicks/cage) were arranged in a 3-wk 2 × 2 factorial design trial whereby they were fed an Se-deficient, corn- and soy-based diet [base diet (BD), 36 μg Se/kg], BD plus 1.0 mg AFB1/kg, BD plus 0.3 mg Se/kg, or BD plus 1.0 mg AFB1/kg and 0.3 mg Se/kg (as 2-hydroxy-4-methylselenobutanoic acid). Serum and spleen were collected at week 3 to assay for cytokines, histology, redox status, selected inflammation- and apoptosis-related genes and proteins, and the selenogenome.

RESULTS

Dietary AFB1 induced growth retardation and spleen injury, decreasing (P < 0.05) body weight gain, feed intake, feed conversion efficiency, and serum interleukin-1β by 17.8-98.1% and increasing (P < 0.05) the spleen index and serum interleukin-6 by 37.6-113%. It also reduced the splenic lymphocyte number, the white pulp region, and histiocyte proliferation in Se-adequate groups. However, Se deficiency aggravated (P < 0.05) these AFB1-induced alterations by 16.2-103%. Moreover, Se deficiency decreased (P < 0.05) splenic glutathione peroxidase (GPX) activity and glutathione-S transferase and glutathione concentrations by 35.6-89.4% in AFB1-exposed groups. Furthermore, Se deficiency upregulated (P < 0.05) the apoptotic (Caspase 3 and Caspase 9) and antimicrobial (β defensin 1 and 2) genes, but downregulated (P < 0.05) antiapoptotic (B-cell lymphoma 2) and inflammatory (E3 ubiquitin-protein ligase CBL-B) genes at the mRNA and/or protein level in AFB1 supplementation groups. Additionally, Se deficiency downregulated (P < 0.05) GPX3, thioredoxin reductase 1 (TXNRD 1), GPX4, and selenoprotein (SELENO) S, and upregulated (P < 0.05) SELENOT and SELENOU in spleen in AFB1 administered groups.

CONCLUSIONS

Dietary Se deficiency exacerbated AFB1-induced spleen injury in chicks, partially through the regulation of oxidative stress, inflammatory and apoptotic signaling, and 6 selenoproteins.

Time-Course Effects of Acute Aflatoxin B1 Exposure on Hepatic Mitochondrial Lipids and Oxidative Stress in Rats

Aflatoxins are secondary metabolites of certain Aspergillus species, that contaminate staple foods, particularly in developing countries. Aflatoxin B1 (AFB1) is the most toxic and common of the major types of aflatoxins. AFB1 is hepatotoxic and has been implicated in increasing the risk of hepatocellular carcinoma (HCC). We have previously shown that subacute exposure to AFB1 for 7 days disrupts hepatic lipids; therefore, this study determined the time-course effects of acute aflatoxin exposure on hepatic mitochondrial lipids and oxidative stress. To achieve this, thirty male albino rats were randomly assigned to six groups. The groups received an oral dose of 1 mg/kg body weight AFB1 or vehicle only (controls) for one, four, or seven days, respectively. Twenty-four hours after the last dose, the animals were sacrificed and liver excised. Mitochondria and cytosolic fractions were obtained from the liver after which lipids (cholesterol, triacylglycerols) were determined in the mitochondria while biomarkers of oxidative stress (glutathione, glutathione transferase (GST), glutathione peroxidase (GPx), glutathione reductase, nitric oxide (NO), malonaldehyde (MDA), thioredoxin reductase (TR), and superoxide dismutase (SOD) were determined spectrophotometrically in the mitochondria and cytosolic fractions. The expression of genes (Nrf2, Acc, Nqo1, and HmgCoa) were determined using quantitative RT-PCR. Results showed that AFB1 significantly increased mitochondrial cholesterol at day seven (treatment vs. control, p = 0.016). It also increased the concentrations of NO and MDA at day one and day seven while the activity of GPx and concentration of GSH were increased at day seven (p = 0.030) and day one (p = 0.025) alone, respectively, compared to control. The activities of cytosolic GR (p = 0.014), TR (p = 0.046) and GST (p = 0.044) were increased at day seven. AFB1 significantly increased the expression of Nrf2 (p = 0.029) and decreased the expression of Acc (p = 0.005) at day one. This study revealed that AFB1 disrupts hepatic mitochondrial lipids and antioxidant capacity. These changes were dependent on the timing of exposure and did not follow a linear time-course trend. These alterations could be part of the hepatic mitochondria response mechanism to acute AFB1 toxicity.

HAfTs are novel lncRNA transcripts from aflatoxin exposure

The transcriptome can reveal insights into precancer biology. We recently conducted RNA-Seq analysis on liver RNA from male rats exposed to the carcinogen, aflatoxin B1 (AFB1), for 90 days prior to liver tumor onset. Among >1,000 differentially expressed transcripts, several novel, unannotated Cufflinks-assembled transcripts, or HAfTs (Hepatic Aflatoxin Transcripts) were found. We hypothesized PCR-cloning and RACE (rapid amplification of cDNA ends) could further HAfT identification. Sanger data was obtained for 6 transcripts by PCR and 16 transcripts by 5’- and 3’-RACE. BLAST alignments showed, with two exceptions, HAfT transcripts were lncRNAs, >200nt without apparent long open reading frames. Six rat HAfT transcripts were classified as ‘novel’ without RefSeq annotation. Sequence alignment and genomic synteny showed each rat lncRNA had a homologous locus in the mouse genome and over half had homologous loci in the human genome, including at least two loci (and possibly three others) that were previously unannotated. While HAfT functions are not yet clear, coregulatory roles may be possible from their adjacent orientation to known coding genes with altered expression that include 8 HAfT-gene pairs. For example, a unique rat HAfT, homologous to Pvt1, was adjacent to known genes controlling cell proliferation. Additionally, PCR and RACE Sanger sequencing showed many alternative splice variants and refinements of exon sequences compared to Cufflinks assembled transcripts and gene prediction algorithms. Presence of multiple splice variants and short tandem repeats found in some HAfTs may be consequential for secondary structure, transcriptional regulation, and function. In summary, we report novel, differentially expressed lncRNAs after exposure to the genotoxicant, AFB1, prior to neoplastic lesions. Complete cloning and sequencing of such transcripts could pave the way for a new set of sensitive and early prediction markers for chemical hepatocarcinogens.

Comparative Response of the Hepatic Transcriptomes of Domesticated and Wild Turkey to Aflatoxin B₁

The food-borne mycotoxin aflatoxin B₁ (AFB₁) poses a significant risk to poultry, which are highly susceptible to its hepatotoxic effects. Domesticated turkeys (Meleagris gallopavo) are especially sensitive, whereas wild turkeys (M. g. silvestris) are more resistant. AFB₁ toxicity entails bioactivation by hepatic cytochrome P450s to the electrophilic exo-AFB₁-8,9-epoxide (AFBO). Domesticated turkeys lack functional hepatic GST-mediated detoxification of AFBO, and this is largely responsible for the differences in resistance between turkey types. This study was designed to characterize transcriptional changes induced in turkey livers by AFB₁, and to contrast the response of domesticated (susceptible) and wild (more resistant) birds. Gene expression responses to AFB₁ were examined using RNA-sequencing. Statistically significant differences in gene expression were observed among treatment groups and between turkey types. Expression analysis identified 4621 genes with significant differential expression (DE) in AFB₁-treated birds compared to controls. Characterization of DE transcripts revealed genes dis-regulated in response to toxic insult with significant association of Phase I and Phase II genes and others important in cellular regulation, modulation of apoptosis, and inflammatory responses. Constitutive expression of GSTA3 was significantly higher in wild birds and was significantly higher in AFB₁-treated birds when compared to controls for both genetic groups. This pattern was also observed by qRT-PCR in other wild and domesticated turkey strains. Results of this study emphasize the differential response of these genetically distinct birds, and identify genes and pathways that are differentially altered in aflatoxicosis.

Acute aflatoxin B1 - Induced hepatotoxicity alters gene expression and disrupts lipid and lipoprotein metabolism in rats

In this study, alterations in lipid metabolism associated with acute aflatoxin B1 (AFB1) induced hepatotoxicity and gene expression changes underlying these effects were investigated. Rats were orally administered three doses (0.25 mg/kg, 0.5 mg/kg and 1.0 mg/kg) of AFB1 for seven days; after which blood was collected and liver excised. Lipid profiles of plasma and liver were determined spectrophotometrically while the expression of genes associated with lipid and lipoprotein metabolism was assayed by reverse transcriptase polymerase chain reaction. Acute exposure to AFB1 increased the levels of plasma and liver cholesterol, triglycerides and phospholipids. AFB1 at 0.5 mg/kg and 1.0 mg/kg resulted in a dose-dependent (1.2 and 1.5 fold, respectively) downregulation of hepatic Cpt1a with a concomitant 1.2 and 1.5 fold increase in the level of plasma FFA, respectively. A similar observation of 1.2 and 1.3 fold increase was also observed in plasma triglyceride concentration, at both respective doses. AFB1 also decreased the relative expression of Ahr, Lipc and Lcat whereas, it upregulated Scarb1 in a dose dependent manner. AFB1-induced dysregulation of the expression of lipid and lipoprotein metabolizing genes may be one mechanism linking AFB1 to altered lipid metabolism and ultimately risk for coronary heart disease.

Seasonal, age and sex fluctuations in aflatoxin B1 content in the liver and kidney of brown hares (Lepus europaeus Pall)

The goal of this study was to monitor the accumulation of aflatoxin B₁ in the liver and kidney of brown hares (Lepus europaeus Pall) in the region of south-western Slovakia. A total of 65 samples were involved for analysis by RIA method. Brown hares were divided into the groups according to age, sex and season (month). The sex was determined visually after shooting, and the age was assigned from dried eye lens. The average concentration of AFB₁ in the liver of hares was 0.54 ± 0.053 µg/kg, and lower values were measured in the kidney (0.41 ± 0.038 µg/kg). The significantly (P < 0.05) higher values were found in winter months when compared to summer months. According to the age, juvenile animals showed significant higher accumulation of B₁ in both organs than adults (P < 0.05). Wild animals can serve as a good model of real environmental contamination. Thus, monitoring of risk factors such as mycotoxins in the environment is important with regard to public health, as game animals constitute an important part of food chain for humans.