Histological lesions, cell cycle arrest, apoptosis and T cell subsets changes of spleen in chicken fed aflatoxin-contaminated corn

No-observed adverse effect levels of deoxynivalenol and aflatoxin B1 in combination induced immune inhibition and apoptosis in vivo and in vitro

Mycotoxins are toxic metabolites produced by fungal species, commonly exist in animal feeds, and pose a serious risk to human as well as animal health. But limited studies have focused on combined effects of no-observed adverse effect levels. In vivo study, 6 weeks old twenty-four mice were individually exposed to Deoxynivalenol (DON) at 0.1 mg/kg BW, Aflatoxin B1 (AFB1) at 0.01 mg/kg BW, and mixture of DON and AFB1 (0.1 mg/kg BW and 0.01 mg/kg BW, respectively) for 28 days. Then, DON at 0.5 μg/mL, AFB1 at 0.04 μg/mL, and mixtures of DON and AFB1 (0.5 μg/mL, 0.04 μg/mL, respectively) were applied to porcine alveolar macrophages (PAMs) in vitro study. Our in vivo results revealed that the combined no-observed adverse effect levels of DON and AFB1 administration decreased IgA and IgG levels in the serum, the splenic TNF-α, IFN-γ, IL-2 and IL-6 mRNA expression and T-lymphocyte subset levels (CD4+ and CD8+) in the spleen. Additionally, the combined administration increased caspase-3, caspase-9, Bax, Cyt-c, and decreased Bcl-2 protein expression. Taken together, the combined no-observed adverse effect levels of DON and AFB1 could induce immunosuppression, which may be related to apoptosis. This study provides new insights into the combined immune toxicity (DON and AFB1).

Effect on the splenocyte function of weaned piglets induced by continuous lipopolysaccharide injections

Introduction

When piglets are exposed to pathogens for a long period, the immune system organs, among them the spleen, play a major role in combating the stress caused by those pathogens. In the present study, the effect on splenocyte function was investigated in a model of weaned piglets in which stress was induced by multiple low doses of lipopolysaccharide (LPS).

Material and Methods

Forty-eight 28-day-old piglets were divided into two groups: the LPS group and the control group. During the experimental period of thirteen days, the LPS group was intraperitoneally injected with LPS (100 μg/kg) once per day, and the control group was injected with the same volume of 0.9% sterile saline. On the 1st, 5th, 9th and 13th days, the piglets' spleens were collected for isolating splenocytes. The proliferation ability of splenocytes was evaluated by the cell-counting-kit 8 method. Flow cytometry was used to detect cell cycle stage and apoptosis, and the nitric oxide level of cell supernatant was also tested.

Results

In the experimental group, the proliferation ability of splenocytes was enhanced, the proportion of cells in the G0/G1 phase was smaller, and cells were promoted to the S and G2/M phases. Meanwhile, apoptosis was suppressed and nitric oxide release upregulated. The results were significantly different between the LPS group and the control group on the 5th and 9th days.

Conclusion

The difference between the results of one group and those of the other suggest that after the 5th LPS injection, multiple low doses of LPS activated splenocytes and restored the number of splenocytes, which maintained and possibly enhanced the regulation of the immune function of the spleen.

Dietary aflatoxins exposure, environmental enteropathy, and their relation with childhood stunting

Childhood stunting is a global phenomenon affecting more than 149 million children under the age of 5 worldwide. Exposure to aflatoxins (AFs) in utero, during breastfeeding, and consumption of contaminated food affect the gut microbiome, resulting in intestinal dysfunction and potentially contributing to stunting. This review explores the potential relationship between AF exposure, environmental enteropathy and childhood stunting. AFs bind to DNA, disrupt protein synthesis and elicit environmental enteropathy (EE). An EE alters the structure of intestinal epithelial cells, impairs nutrient uptake and leads to malabsorption. This article proposes possible intervention strategies for researchers and policymakers to reduce AF exposure, EE and childhood stunting, such as exposure reduction, the implementation of good agricultural practices, dietary diversification and improving environmental water sanitation and hygiene.

Attenuation and molecular characterization of fowl adenovirus 8b propagated in a bioreactor and its immunogenicity, efficacy, and virus shedding in broiler chickens

Background and Aim

Live-attenuated vaccines are the most successful type of vaccine and could be useful in controlling fowl adenovirus (FAdV) 8b infection. This study aimed to attenuate, molecularly characterize, and determine the immunogenicity, efficacy, and challenge virus shedding in broiler chickens.

Materials and Methods

The FAdV 8b isolate (UPM08136) was passaged onto chicken embryo liver (CEL) cells until attenuation. We sequenced and analyzed the hexon and fiber genes of the passage isolates. The attenuated bioreactor-passage isolate was inoculated into 1-day-old broiler chickens with (attenuated and inactivated) and without booster groups and challenged. Body weight (BW), liver weight (LW), liver: body weight ratio (LBR), FAdV antibody titers, T-lymphocyte subpopulation in the liver, spleen, and thymus, and challenge virus load and shedding were measured.

Results

Typical cytopathic effects with novel genetic changes on CEL cells were observed. The uninoculated control-challenged (UCC) group had significantly lower BW and higher LW and LBR than the inoculated groups. A significantly higher FAdV antibody titer was observed in the challenged non-booster and attenuated booster groups than in the UCC group. T cells in the spleen and thymus of the liver of inoculated chickens were higher than uninoculated control group levels at all-time points and at different times. A significantly higher FAdV challenge virus load was observed in the liver and shedding in the cloaca of UCC chickens than in non-booster chickens.

Conclusion

The FAdV 8b isolate was successfully attenuated, safe, and immunogenic. It reduces virus shedding and is effective and recommended as a vaccine against FAdV infection in broiler chickens.

Aflatoxin B1 administration causes inflammation and apoptosis in the lungs and spleen

Aflatoxin is a naturally occurring mycotoxin that has numerous toxic effects. The main aim of the present study was to evaluate the toxic effects of aflatoxin B1 (AFB1) on the lungs and spleen. Mice were repeatedly exposed to AFB1 (0.3 mg/kg body weight) on alternate days for four weeks via oral route. The histopathological data in AFB1-treated mice show alveolar epithelial hyperplasia with inflammation and the presence of numerous alveolar macrophages with minimal hemorrhage. There was an increase in vascular neutrophils and interstitial inflammation. The branching of vessels was plugged with neutrophils. AFB1 administration also causes splenomegaly. The AFB1-treated spleen shows the tingible body macrophages (TBM) scattered within the splenic white pulp. Apoptosis may lead to atrophy in a selected region of the white pulp area. There is a decrease in cellularity within the periarteriolar lymphatic sheath (PALS). The inflammation causes the congestion of red pulp with the increase in nuclear debris, and vacuoles are also visible. The flow cytometry data further suggests enhanced apoptosis in lung and spleen cells.

Aflatoxin B1 in poultry liver: Toxic mechanism

Aflatoxin B1 (AFB1) is the most common carcinogenic toxin in livestock and poultry feed, seriously endangering poultry production and public health. Liver is the most important organ for the metabolism of exogenous and endogenous substances in the body. AFB1 produces toxicity under the biotransformation of cytochrome P450 microparticle oxidase (CYP450). Hepatocytes are the most important cells for synthesizing CYP450 enzymes, so that AFB1 has the most significant effect on the liver. AFB1 can induce liver cell damage in poultry through a variety of molecular mechanisms, and the main of damage mechanisms have been discovered so far include oxidative damage, promoting apoptosis, influencing hepatocyte gene expression, interfering with hepatocyte autophagy, pyroptosis and necroptosis. This article reviewed the molecular mechanism of AFB1 inducing liver injury in poultry, hopefully, to provid a new direction and theoretical basis for the development of a new AFB1 detoxification method.

Response surface model to illustrate the benefits of tryptophan, melatonin, and N,N-dimethylglycine in quail chicks exposed to aflatoxin B1

A dose-response assay in a central composite design platform was conducted to investigate the responses (performance, immunity, and meat quality) of quail chicks to dietary tryptophan (Trp), melatonin (MEL), and N,N-dimethylglycine (DMG) exposed to aflatoxin B1 (AFB1). A total of 1,275 quail chicks were randomly allotted to 85-floor pens consisting of 17 treatments with 5 replicates and 15 birds per each pen. Dietary MEL and DMG had a different effect on growth rate and interacted with dietary Trp and AFB1 during the first 4 wk of age, while their effect disappeared at the last week of the experiment. Dietary Trp and AFB1 were only significant on the gain of quail chick after d 28 of the assay. During the second and third weeks of age, the reduction in feed intake caused by AFB1 attenuated by dietary MEL and DMG and dietary Trp profoundly affects feed intake in the last 2 wk of the experiment. Dietary MEL and DMG were effective on feed conversion ratio (FCR) during the second and third weeks of age. AFB1 decreased breast meat yield (BMY) and thigh meat yield (TMY), but the inclusion of either MEL or DMG removed the adverse effects of AFB1. Dietary Trp increased BMY, but it did not affect TMY. Increasing dietary Trp linearly increased the Lactobacillus bacteria (LAB) population, and AFB1 negatively impacts the LAB population. The inclusion of dietary DMG removed that negative effect on LAB. Although AFB1 decreased the antibody production against SRBC-antigen, increasing dietary Trp in intoxicated quails increased the plasma antibody in SRBC-challenged birds. At low levels of dietary Trp (0.15-0.19%), the addition of DMG increased malondialdehyde (MDA) production while increasing Trp reversed this adverse situation. In conclusion, these supplements may interact with AFB1 in younger chicks, and dietary Trp and AFB1 have a significant impact on the growth performance of quail chicks during the fifth and sixth week of age.

Antifungal Activity of Juglans-regia-Mediated Silver Nanoparticles (AgNPs) against Aspergillus-ochraceus-Induced Toxicity in In Vitro and In Vivo Settings

Aflatoxins produced by some species of Aspergillus are considered secondary toxic fungal by-products in feeds and food. Over the past few decades, many experts have focused on preventing the production of aflatoxins by Aspergillus ochraceus and also reducing its toxicity. Applications of various nanomaterials in preventing the production of these toxic aflatoxins have received a lot of attention recently. The purpose of this study was to ascertain the protective impact of Juglans-regia-mediated silver nanoparticles (AgNPs) against Aspergillus-ochraceus-induced toxicity by exhibiting strong antifungal activity in in vitro (wheat seeds) and in vivo (Albino rats) settings. For the synthesis of AgNPs, the leaf extract of J. regia enriched with high phenolic (72.68 ± 2.13 mg GAE/g DW) and flavonoid (18.89 ± 0.31 mg QE/g DW) contents was used. Synthesized AgNPs were characterized by various techniques, including TEM, EDX, FT-IR, and XRD, which revealed that the particles were spherical in shape with no agglomeration and fine particle size in the range of 16-20 nm. In vitro antifungal activity of AgNPs was tested on wheat grains by inhibiting the production of toxic aflatoxins by A. ochraceus. According to the results obtained from High-Performance Liquid Chromatography (HPLC) and Thin-Layer Chromatography (TLC) analyses, there was a correlation between the concentration of AgNPs and a decrease in the production of aflatoxin G1, B1, and G2. For in vivo antifungal activity, Albino rats were administrated with different doses of AgNPs in five groups. The results indicated that the feed concentration of 50 µg/kg feed of AgNPs was more effective in improving the disturbed levels of different functional parameters of the liver (alanine transaminase (ALT): 54.0 ± 3.79 U/L and aspartate transaminase (AST): 206 ± 8.69 U/L) and kidney (creatinine 0.49 ± 0.020 U/L and BUN 35.7 ± 1.45 U/L), as well as the lipid profile (LDL 22.3 ± 1.45 U/L and HDL 26.3 ± 2.33 U/L). Furthermore, the histopathological analysis of various organs also revealed that the production of aflatoxins was successfully inhibited by AgNPs. It was concluded that the harmful effects of aflatoxins produced by A. ochraceus can be successfully neutralized by using J. regia-mediated AgNPs.

Integrated Transcriptome Analysis Reveals mRNA-miRNA Pathway Crosstalk in Roman Laying Hens' Immune Organs Induced by AFB1

Aflatoxin B1 (AFB1) is a widely distributed contaminant in moldy corn, rice, soybean, and oil crops. Many studies have revealed its adverse effects, such as carcinogenicity, immunotoxicity, and hepatotoxicity, on the health of humans and animals. To investigate the immunotoxic effects on chicken immune organs induced by AFB1, we integrated RNA and small-RNA sequencing data of the spleen and the bursa of Fabricius to elucidate the response of the differentially expressed transcriptional profiles and related pathways. AFB1 consumption negatively influenced egg quality, but no obvious organ damage was observed compared to that of the control group. We identified 3918 upregulated and 2415 downregulated genes in the spleen and 231 upregulated and 65 downregulated genes in the bursa of Fabricius. We confirmed that several core genes related to immune and metabolic pathways were activated by AFB1. Furthermore, 42 and 19 differentially expressed miRNAs were found in the spleen and the bursa of Fabricius, respectively. Differentially expressed genes and target genes of differentially expressed miRNAs were mainly associated with cancer progression and immune response. The predicted mRNA-miRNA pathway network illustrated the potential regulatory mechanisms. The present study identified the transcriptional profiles and revealed potential mRNA-miRNA pathway crosstalk. This genetic regulatory network will facilitate the understanding of the immunotoxicity mechanisms of chicken immune organs induced by high concentrations of AFB1.

Efficacy, humoral, and cell-mediated immune response of inactivated fowl adenovirus 8b propagated in chicken embryo liver cells using bioreactor in broiler chickens

Background and Aim

Fowl adenovirus (FAdV) 8b causes inclusion body hepatitis, resulting in major economic losses globally among chickens. The objectives were to inactivate FAdV 8b isolate propagated in chicken embryo liver (CEL) cells using a stirred tank bioreactor (UPM08136P5B1) and determine the humoral and cell-mediated immune response, efficacy, and virus shedding in broiler chickens.

Materials and Methods

The FAdV 8b isolate UPM08136P5B1 was inactivated using binary ethyleneimine, adjuvanted with Montanide 71VG, inoculated into day-old broiler chickens in a booster group (BG) and non-booster group (NBG), and challenged with a pathogenic FAdV 8b strain. Clinical signs, gross lesions, body weight (BW), liver: body weight ratio, FAdV antibody titer using enzyme-linked immunosorbent assay, and histopathological changes were recorded. The CD3+, CD4+, and CD8+ T-lymphocyte profiles of the liver, spleen, and thymus using flow cytometry, and viral load in liver and cloacal shedding using quantitative polymerase chain reaction were evaluated.

Results

Chickens in the challenged control group (CCG) exhibited mild clinical signs, gross lesions, and histopathological changes, which were absent in the inoculated groups, and had lower BW and higher liver BW ratio than chickens in the unchallenged control group (UCG); BG and NBG on 35- and 42-days post-inoculation (DPI). Chickens in NBG and BG had higher antibodies than UCG on 7, 21, 35, and 42 DPI. The challenged BG and NBG produced higher antibodies than the CCG on 35 DPI. T-lymphocytes were higher among the inoculated groups than UCG in the liver, spleen, and thymus. Inoculated challenged groups recorded higher CD3+, CD4+, and CD8+ T-lymphocytes on 35 and 42 DPI than CCG. The challenged control group had a significantly higher viral load in the liver than challenged that in BG on 35 DPI and BG and NBG on 42 DPI. The challenged control group had significantly higher challenge FAdV shedding than challenged inoculated groups on 35 and NBG on 42 DPI.

Conclusion

UPM08136P5B1 was successfully inactivated and mixed with Montanide 71VG. The inactivated vaccine candidate that induced humoral and cellular immunity was effective, reduced FAdV load in the liver, and shedding in the cloaca, and could be useful against FAdV 8b infections in chickens.

Protective and detoxifying effects conferred by selenium against mycotoxins and livestock viruses: A review

Animal feed can easily be infected with molds during production and storage processes, and this can lead to the production of secondary metabolites, such as mycotoxins, which eventually threaten human and animal health. Furthermore, livestock production is also not free from viral infections. Under these conditions, the essential trace element, selenium (Se), can confer various biological benefits to humans and animals, especially due to its anticancer, antiviral, and antioxidant properties, as well as its ability to regulate immune responses. This article reviews the latest literature on the antagonistic effects of Se on mycotoxin toxicity and viral infections in animals. We outlined the systemic toxicity of mycotoxins and the primary mechanisms of mycotoxin-induced toxicity in this analysis. In addition, we pay close attention to how mycotoxins and viral infections in livestock interact. The use of Se supplementation against mycotoxin-induced toxicity and cattle viral infection was the topic of our final discussion. The coronavirus disease 2019 (COVID-19) pandemic, which is currently causing a health catastrophe, has altered our perspective on health concerns to one that is more holistic and increasingly embraces the One Health Concept, which acknowledges the interdependence of humans, animals, and the environment. In light of this, we have made an effort to present a thorough and wide-ranging background on the protective functions of selenium in successfully reducing mycotoxin toxicity and livestock viral infection. It concluded that mycotoxins could be systemically harmful and pose a severe risk to human and animal health. On the contrary, animal mycotoxins and viral illnesses have a close connection. Last but not least, these findings show that the interaction between Se status and host response to mycotoxins and cattle virus infection is crucial.

Mycotoxins binder supplementation alleviates aflatoxin B1 toxic effects on the immune response and intestinal barrier function in broilers

This experiment was conducted to evaluate whether a commercial mycotoxins-binder, XL, could effectively attenuate the negative effects of Aflatoxin B₁ (AFB₁) on growth performance, immunological function, and intestinal health in birds. Two hundred forty 1-day-old Arbor Acres broiler chickens were randomly divided into 4 treatments using a 2 × 2 factorial randomized design with 2 levels of dietary mycotoxins binder (0 or 2g /kg) and 2 AFB₁ supplemented levels (0 or 200 μg/kg) from 0 to 42 d. Results showed that AFB₁ exposure impaired growth performance by decreasing BWG in 1–21 d and 1–42 d, decreasing FI in 1–21 d, increasing FCR in 1–21 d and 1–42 d (P < 0.05). Broilers fed AFB₁- contaminated diet impaired the immune function, as evident by decreasing IgA contents, Newcastle disease antibody titers in serum, and sIgA contents of jejunal mucosa at 21 d (P < 0.05). On the other hand, AFB₁ challenge significantly increased the gene expression of proinflammatory factors in spleen at 21 d and liver at 42 d, and significantly decreased claudin-1 expression at 42 d and occludin expression at 21 d, and increased claudin-2 at 21 d in jejunum of broiler chickens (P < 0.05) compared to the basal diet group. Dietary XL supplementation significantly decreased the gene expression of IL-6 in spleen at 21 d and IL-1β in liver at 42 d, cytochrome P450 3A4 (CYP3A4) expression in liver at 21 d of broilers (P < 0.05) compared with the nonsupplemented birds, regardless of AFB₁ challenged or not. Inclusion of 2 g/kg XL increased serum ALB at 42 d, IgM and IgA at 42 d, Newcastle disease antibody titer level at 35 d (P < 0.05). Dietary XL addition enhanced intestinal barrier function by increasing the expression of claudin-1 at 21 d and Occludin at 42 d (P < 0.05) in jejunum. Conclusively, 2 g/kg mycotoxins-binder can relieve the toxic effect of AFB₁ on broilers.

Effects of compound probiotics and aflatoxin-degradation enzyme on alleviating aflatoxin-induced cytotoxicity in chicken embryo primary intestinal epithelium, liver and kidney cells

Aflatoxin B₁ (AFB₁) is one of the most dangerous mycotoxins for humans and animals. This study aimed to investigate the effects of compound probiotics (CP), CP supernatant (CPS), AFB₁-degradation enzyme (ADE) on chicken embryo primary intestinal epithelium, liver and kidney cell viabilities, and to determine the functions of CP + ADE (CPADE) or CPS + ADE (CPSADE) for alleviating cytotoxicity induced by AFB₁. The results showed that AFB₁ decreased cell viabilities in dose-dependent and time-dependent manners. The optimal AFB₁ concentrations and reactive time for establishing cell damage models were 200 µg/L AFB₁ and 12 h for intestinal epithelium cells, 40 µg/L and 12 h for liver and kidney cells. Cell viabilities reached 231.58% (p < 0.05) for intestinal epithelium cells with CP addition, 105.29% and 115.84% (p < 0.05) for kidney and liver cells with CPS additions. The further results showed that intestinal epithelium, liver and kidney cell viabilities were significantly decreased to 87.12%, 88.7% and 84.19% (p < 0.05) when the cells were exposed to AFB₁; however, they were increased to 93.49% by CPADE addition, 102.33% and 94.71% by CPSADE additions (p < 0.05). The relative mRNA abundances of IL-6, IL-8, TNF-α, iNOS, NF-κB, NOD1 (except liver cell) and TLR2 in three kinds of primary cells were significantly down-regulated by CPADE or CPSADE addition, compared with single AFB₁ group (p < 0.05), indicating that CPADE or CPSADE addition could alleviate cell cytotoxicity and inflammation induced by AFB₁ exposure through suppressing the activations of NF-κB, iNOS, NOD1 and TLR2 pathways.

Structure of the Eurasian moorhen spleen: A comprehensive study using gross anatomy, light, and transmission electron microscopy

The spleen is the largest secondary lymphoid organ with major roles in the removal of blood-borne antigens. The Eurasian moorhen is a wild aquatic bird that revealed the adaptation to harsh environmental conditions. Information regarding the structural features of moorhen's spleen is lacking. The present study aimed to describe the composition of moorhen's spleen using anatomical dissection, histology, histochemistry, immunohistochemistry, and transmission electron microscopy. The spleen appeared as a brownish red sickle-shaped organ close to the proventriculus and gizzard. The splenic capsule was very thin, and the trabeculae were poorly developed. The white pulp formed of the periarteriolar lymphoid sheath, lymphoid follicles, and periellipsoidal lymphatic sheath. The red pulp composed of sinusoids and cords and contained various types of blood cells. Blood vessels were observed within the splenic capsule and inside the parenchyma. Notably, penicillar capillaries (PCs) appeared branched and surrounded by well-developed ellipsoids. Direct connections were observed between PCs and splenic sinusoids suggesting a closed type of circulation. Ultrastructurally, intercellular spaces and vascular channels were evident in the wall of PCs. Ellipsoid-associated cells, lymphocytes, monocytes, and heterophils were observed within splenic ellipsoids. Ellipsoids were thus suggested as a crucial component of moorhen's spleen. Numerous MafB-immunoreactive (IR) macrophages were seen within the red pulp. Splenic cords contained the highest number of PHH3-IR cells, while CCASP3-IR cells were exclusive to follicles of the white pulp. In conclusion, the structure of moorhen's spleen revealed species-specific features. The findings of the present study could help to improve the immunity of domestic birds.

Lycopene alleviates AFB1-induced immunosuppression by inhibiting oxidative stress and apoptosis in the spleen of mice

Lycopene (LYC) has been reported to exhibit antioxidant and immunoprotective activities, and our previous studies confirmed that LYC can alleviate multiple tissue damage induced by aflatoxin B1 (AFB1). However, it is unclear whether LYC could relieve the AFB1-induced immunosuppression. Thus, forty-eight male mice were randomly allocated and treated with LYC (5 mg kg-1) and/or AFB1 (0.75 mg kg-1) by intragastric administration for 30 days. We found that LYC alleviated AFB1-induced immunosuppression by relieving splenic structure injury and increasing the spleen weight, spleen coefficient, T lymphocyte subsets, the contents of IL-2, IFN-γ and TNF-α in serum, as well as the mRNA expression of IL-2, IFN-γ and TNF-α in spleen. Furthermore, LYC inhibited oxidative stress induced by AFB1via decreasing the levels of reactive oxygen species (ROS), hydrogen peroxide (H2O2) and malondialdehyde (MDA), while enhancing the total antioxidant capacity (T-AOC) and antioxidant enzyme activities. In addition, LYC also restrained splenic apoptosis through blocking mitochondria-mediated apoptosis in AFB1 intoxicated mice, presenting as the increase of mitochondrial membrane potential, and the decrease of cytoplasmic Cyt-c protein expression, cleaved Caspase-3 protein expression, Caspase-3/9 activities and mRNA expressions, as well as balancing the mitochondrial protein and mRNA expressions of Bax and Bcl-2. These results indicate that LYC can alleviate AFB1-induced immunosuppression by inhibiting oxidative stress and mitochondria-mediated apoptosis of mice spleen.

Excess dietary tryptophan mitigates aflatoxicosis in growing quails

A biological assay was carried out to evaluate the impact of dietary tryptophan (TRP) in aflatoxin B₁ -contaminated diets (AFB₁ -D) on performance, blood parameters, immunity, meat quality and microbial populations of intestine in Japanese quails. Six experimental diets were formulated to include two levels of dietary TRP; 2.9 (moderate high: MH-TRP) and 4.9 g/kg (excess: Ex-TRP); and three levels of AFB₁ (0.0, 2.5, and 5.0 mg/kg). Each experimental diet was fed to the one of the six groups of birds from 7 to 35 days of age in a completely randomized design with 2 × 3 factorial arrangement. Decrease in feed intake, body weight gain and gain:feed in birds fed 5.0 mg/kg AFB₁ -D was restored to the control level by 4.9 g TRP/kg of the diet. The hepatic enzymes in blood were elevated in quails fed on AFB₁ -D but attenuated by 4.9 g TRP/kg of the diet (Ex-TRP; p ≤ .01). High serum uric acid in birds challenged with AFB₁ significantly decreased by Ex-TRP (p ≤ .01). The skin thickness to 2,4-dinitro-1-chlorobenzene challenge suppressed by AFB₁ but increased by Ex-TRP diet (p ≤ .02). The AFB₁ increased the malondialdehyde in meat, whereas TRP efficiently diminished malondialdehyde production (p ≤ .01). The greatest drip loss and pH in meat were observed in the birds fed 5.0 mg/kg AFB₁ -D but Ex-TRP augmented the adverse effects of AFB₁ (p ≤ .01). The Ex-TRP reduced the total microbial and Escherichia coli counts (p ≤ .01). The adverse effect of AFB₁ on ileal Lactic acid bacteria was completely prevented by Ex-TRP (p ≤ .03). This study showed that tryptophan supplementation could be considered as a powerful nutritional tool to ameliorate the adverse effects of AFB₁ in growing quails.

The first in vivo application of synthetic polymers based on methacrylic acid as an aflatoxin sorbent in an animal model

This study attempts to evaluate the potential aflatoxin binder activity of a molecularly imprinted polymer (TMU95) synthesized to target the aflatoxin B₁ (AFB₁) analog molecule in comparison to a commercial toxin binder (CTB). Adsorption experiments were carried out to assess the ability to bind to AFB₁ at various pH values. The strength of binding was investigated by the chemisorption index. The isothermal analysis was used to determine the maximum adsorption capacity values. The ability of TMU95 and CTB to adsorb essential minerals was evaluated and the obtained data suggested that CTB would significantly reduce availability of them compared to TMU95. The in vivo efficacy of TMU95 as an aflatoxin (AF) binder in duckling exposed to aflatoxin-contaminated feed from 4 to 18 days of age in comparison to the CTB was also assessed. TMU95 and CTB were effective in reducing the adverse effects caused by AFs on feed conversion ratio of duckling (p ≤ 0.01), and also showed a minor reduction of injuries caused by AFs on visceral organs enlargement (p ≤ 0.01). It was concluded that TMU95 could absorb AFB₁ in vitro efficiently and had beneficial health effects that could alleviate some of the toxic effects of AFs on growing duckling performance similar to CTB.

Harmful Effects and Control Strategies of Aflatoxin B₁ Produced by Aspergillus flavus and Aspergillus parasiticus Strains on Poultry: Review

The presence of aflatoxin B₁ (AFB₁) in poultry diets decreases the hatchability, hatchling weight, growth rate, meat and egg production, meat and egg quality, vaccination efficiency, as well as impairing the feed conversion ratio and increasing the susceptibility of birds to disease and mortality. AFB₁ is transferred from poultry feed to eggs, meat, and other edible parts, representing a threat to the health of consumers because AFB₁ is carcinogenic and implicated in human liver cancer. This review considers how AFB₁ produced by Aspergillus flavus and Aspergillus parasiticus strains can affect the immune system, antioxidant defense system, digestive system, and reproductive system in poultry, as well as its effects on productivity and reproductive performance. Nutritional factors can offset the effects of AFB₁ in poultry and, thus, it is necessary to identify and select suitable additives to address the problems caused by AFB₁ in poultry.

Proanthocyanidins Alleviates AflatoxinB₁-Induced Oxidative Stress and Apoptosis through Mitochondrial Pathway in the Bursa of Fabricius of Broilers

Aflatoxin B₁ (AFB₁) is a serious threat to the poultry industry. Proanthocyanidins (PCs) demonstrates a broad range of biological, pharmacological, therapeutic, and chemoprotective properties. The aim of this study was to investigate the ameliorative effects of PCs against AFB₁-induced histopathology, oxidative stress, and apoptosis via the mitochondrial pathway in the bursa of Fabricius (BF) of broilers. One hundred forty-four one-day old Cobb chicks were randomly assigned into four treatment groups of six replicates (6 birds each replicate) for 28 days. Groups were fed on the following four diets; (1) Basal diet without addition of PCs or AFB₁ (Control); (2) basal diet supplemented with 1 mg/kg AFB₁ from contaminated corn (AFB₁); (3) basal diet supplemented with 250 mg/kg PCs (PCs); and (4) basal diet supplemented with 1 mg/kg AFB₁ + 250 mg/kg PCs (AFB₁+ PCs). The present study results showed that antioxidant enzymes activities of total superoxide dismutase (T-SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and glutathione S-transferase (GST) in AFB₁ treated group were (p < 0.05) decreased, whereas malondialdehyde (MDA) contents were significantly increased in comparison with the control group. Furthermore, we found that dietary PCs treatment ameliorated AFB₁-induced oxidative stress in the BF through inhibiting the accumulation of MDA content and enhancing the antioxidant enzymes activities (T-SOD, CAT, GSH-Px, and GST). Similarly, PCs markedly enhanced messenger RNA (mRNA) expression of antioxidant genes (SOD, CAT, GPx1, and GST) in comparison with AFB₁ group. Moreover, histological results showed that PCs alleviated AFB₁-induced apoptotic cells in the BF of broilers. In addition, both mRNA and protein expression results manifested that mitochondrial-apoptosis-associated genes (Bax, caspase-9, caspase-3, and p53 and cytochrome c) showed up-regulation, while (Bcl-2) showed down-regulation in AFB₁ fed group. The supplementation of PCs to AFB₁ diet significantly reversed the mRNA and protein expression of these apoptosis-associated genes, as compared to the AFB₁ group. Our results demonstrated that PCs ameliorated AFB₁-induced oxidative stress by modulating the antioxidant defense system and apoptosis in the BF through mitochondrial pathway in broilers.

Effects of aflatoxin B1 on the cell cycle distribution of splenocytes in chickens

The purpose of the present study was to evaluate effects of aflatoxin B1 (AFB1) on the cell cycle and proliferation of splenic cells in chickens. A total of 144 one-day-old Cobb male chickens were randomly divided into 2 equal groups of 72 each and were fed on diets as follows: a control diet and a 0.6 mg/kg AFB1 diet for 21 days. The AFB1 diet reduced body weight, absolute weight and relative weight of the spleen in broilers. Histopathological lesions in AFB1 groups were characterized as slight congestion in red pulp and lymphocytic depletion in white pulp. Compared with the control group, the expression levels of ataxia-telangiectasia mutated (ATM), cyclin E1, cyclin-dependent kinases 6 (CDK6), CDK2, p53, p21 and cyclin B3 mRNA were significantly increased, while the mRNA expression levels of cyclin D1, cdc2 (CDK1), p16, p15 were significantly decreased in the AFB1 groups. Significantly decreased proliferating cell nuclear antigen (PCNA) expression and arrested G0G1 phases of the cell cycle were also seen in the AFB1 groups. In conclusion, dietary AFB1 could induce cell cycle blockage at G0G1 phase and impair the immune function of the spleen. Cyclin D1/CDK6 complex, which inhibits the activin/nodal signaling pathway, might play a significant role in the cell cycle arrest induced by AFB1.

Selenium Ameliorates AFB1-Induced Excess Apoptosis in Chicken Splenocytes Through Death Receptor and Endoplasmic Reticulum Pathways

Aflatoxin B₁ (AFB₁) can cause hepatotoxicity, genotoxicity, and immunosuppressive effects for a variety of organisms. Selenium (Se), as an essential nutrient element, plays important protective effects against cell apoptosis induced by AFB₁. This research aimed to reveal the ameliorative effects of selenium on AFB₁-induced excess apoptosis in chicken splenocytes through death receptor and endoplasmic reticulum pathways in vivo. Two hundred sixteen neonatal chickens, randomized into four treatments, were fed with basal diet (control treatment), 0.4 mg/kg Se supplement (+Se treatment), 0.6 mg/kg AFB₁ (AFB₁ treatment), and 0.6 mg/kg AFB₁ + 0.4 mg/kg Se (AFB₁ + Se treatment) during 21 days of experiment, respectively. Compared with the AFB₁ treatment, the levels of splenocyte apoptosis in the AFB₁ + Se treatment were obviously dropped by flow cytometry and TUNEL assays although they were still significantly higher than those in the control or + Se treatments. Furthermore, the mRNA expressions of CASP-3, CASP-8 and CASP-10, GRP78, GRP94, TNF-α, TNF-R1, FAS, and FASL of splenocytes in the AFB₁ + Se treatment by qRT-PCR assay were significantly decreased compared with the AFB₁ treatment. These results indicate that Se could partially ameliorate the AFB₁-caused excessive apoptosis of chicken splenocytes through downregulation of endoplasmic reticulum and death receptor pathway molecules. This research may rich the knowledge of the detoxification mechanism of Se on AFB₁-induced apoptosis.

Effect of aflatoxin experimental ingestion and Eimeira vaccine challenges on intestinal histopathology and immune cellular dynamic of broilers: applying an Intestinal Health Index

The present study evaluated the effect of aflatoxin B1 and Eimeria vaccine challenges and their interaction on intestinal morphology, applying the morphometric index "I See Inside" (ISI). Immune cellular response and broiler chicken performance were also studied. A total of 240 broiler chickens were divided in a 2 × 2 factorial arrangement with 4 treatments, T1: Control diet and no challenge (CON), T2: Aflatoxin B1 (AFLA), T3: Control diet and Eimeria challenge (COC), and T4: Aflatoxin B1 and Eimeria challenge (AFLA+COC). The mathematical morphometric index ISI was applied to evaluate macro and microscopic alterations. Samples of liver and jejunum were analyzed for macrophages, CD4+, and CD8+ cells counting by immunohistochemistry at 7, 14, and 21 d of age. Chickens challenged with Eimeria presented higher ISI of macroscopic alterations associated to Eimeria lesion at the medium small intestine, lower body weight gain (BWG) and feed intake (FI), and worse feed conversion ratio compared to non-challenged birds. Both Eimeria and aflatoxin challenges modulated the immune cells in the jejunum and liver, generally increasing the number of macrophages, CD4+, and CD8+ cells in relation to the control group. Birds from COC and COC+AFLA groups presented higher ISI histological score in the jejunum at 7 and 14 d of age compared to the CON and AFLA groups. The reduction of FI and BWG was correlated to high histological ISI and resulted in a high presence of immune cells in tissues, suggesting immune response demand. The histological ISI had statistical correlation to broiler performance.

Effect of High Protein Diet and Probiotic Lactobacillus casei Shirota Supplementation in Aflatoxin B1-Induced Rats

Probiotic Lactobacillus casei Shirota (LcS) is a potential decontaminating agent of aflatoxin B₁ (AFB₁). However, few studies have investigated the influence of diet, especially a high protein (HP) diet, on the binding of AFB₁ by probiotics. This research was conducted to determine the effect of HP diet on the ability of LcS to bind AFB₁ and reduce aflatoxin M₁ (AFM₁) in AFB₁-induced rats. Sprague Dawley rats were randomly divided into three groups: A (HP only), B (HP + 10⁸ CFU LcS + 25 μg AFB1/kg BW), and C (HP + 25 μg AFB1/kg BW). Levels of AST and ALP were higher in all groups but other liver function's biomarkers were in the normal range, and the liver's histology showed no structural changes. The urea level of rats in group B (10.02 ± 0.73 mmol/l) was significantly lower (p < 0.05) than that of rats in group A (10.82 ± 0.26 mmol/l). The presence of carcinoma in the small intestine and colon was more obvious in group C than in group B. Moreover, rats in group B had significantly (p < 0.05) lower AFM₁ concentration (0.39 ± 0.01 ng/ml) than rats in group C (5.22 ± 0.28 ng/ml). Through these findings, LcS supplementation with HP diet alleviated the adverse effects of AFB₁ by preventing AFB₁ absorption in the small intestine and reducing urinary AFM₁.

The mitochondrial and endoplasmic reticulum pathways involved in the apoptosis of bursa of Fabricius cells in broilers exposed to dietary aflatoxin B1

Aflatoxin B₁ (AFB₁), a toxic metabolite produced by some fungi, exerts well-known hepatocarcinogenic and immunosuppressive effects, the latter can increase the apoptotic immune cells in vitro. However, it is largely unknown that which signaling pathways contribute to excessive apoptosis of immune cells which induced by AFB₁. In this study, we investigated the roles of the mitochondria, endoplasmic reticulum (ER) and death receptor activated apoptotic pathways in the bursal of Fabricius (BF) cells in the broilers exposed to AFB₁ diet. We found that (1) AFB₁ diet induced morphological changes in the BF. (2) FCM and TUNEL methods showed that excessive apoptosis could be resulted from AFB₁ intake. (3) AFB₁-induced apoptosis of bursal cells involved mitochondrial pathway (increase of Bax, Bak, cytC, caspase-9, Apaf-1, caspase-3 and decrease of Bcl-2 and Bcl-xL) and ER pathway (increase of Grp78/Bip, Grp94 and CaM). (4) Oxidative stress was confirmed in the BF of chicken fed on AFB₁ diet. Overall, this work is the first to demonstrate that the activation of mitochondria and ER apoptosis pathways can lead to excessive apoptosis in BF cells, and oxidative stress is a crucial driver during AFB₁ exposure.

The molecular mechanism of cell cycle arrest in the Bursa of Fabricius in chick exposed to Aflatoxin B 1

Aflatoxin B₁ shows potent hepatotoxic, carcinogenic, genotoxic, immunotoxic potential in humans and many species of animals. The aim of this study was to clarify the underlying mechanism of G₀G₁ phase and G₂M phase arrest of cell cycle in the bursa of Fabricius in broilers exposed to dietary AFB₁. 144 one-day-old healthy Cobb broilers were randomly divided into two groups and fed on control diet and 0.6 mg·Kg⁻¹ AFB₁ diet for 3 weeks. Histological observation showed that AFB₁ induced the increase of nuclear debris and vacuoles in lymphoid follicle of BF. Results of flow cytometry studies showed that bursal cells arrested in G₂M phase at 7 days of age and blocked in G₀G₁ phase at 14 and 21 days of age following exposure to AFB₁. The qRT-PCR analysis indicated that cell cycle arrested in G₂M phase via ATM-Chk2-cdc25-cyclin B/cdc2 pathway, and blocked in G₀G₁ phase through ATM-Chk2-cdc25-cyclin D/CDK6 pathway and ATM-Chk2-p21-cyclin D/CDK6 route. In a word, our results provided new insights that AFB₁ diet induced G₂M and G₀G₁ phase blockage of BF cells in different periods, and different pathways were activated in different arrested cell cycle phase.

The mitochondrial and death receptor pathways involved in the thymocytes apoptosis induced by aflatoxin B1

Aflatoxin B₁ (AFB₁) is a potent immunosuppressive agent in endotherms, which can be related to the up-regulated apoptosis of immune organs. In this study, we investigated the roles of the mitochondrial, death receptor, and endoplasmic reticulum pathways in Aflatoxin B₁ induced thymocytes apoptosis. Chickens were fed an aflatoxin B₁ containing diet (0.6 mg/kg AFB₁) for 3 weeks. Our results showed that (1) AFB₁ diet induced the decrease of T-cell subsets, morphological changes, and excessive apoptosis of thymus. (2) The excessive apoptosis involved the mitochondrial pathway (up-regulation of Bax, Bak, cytC and down-regulation of Bcl-2 and Bcl-xL) and death receptor pathway (up-regulation of FasL, Fas and FADD). (3) Oxidative stress, an apoptosis inducer, was confirmed in the thymus. In conclusion, this is the first study to demonstrate that mitochondrial and death receptor pathways involved in AFB₁ induced thymocytes apoptosis in broilers.

Aflatoxin B1 affects apoptosis and expression of death receptor and endoplasmic reticulum molecules in chicken spleen

Aflatoxin B₁ (AFB₁) is a natural product of the Aspergillus genus of molds, which grow on several foodstuffs stored in hot moist conditions, and is among the most potent hepatocarcinogens and immunosuppression presently known. The latter was related to the up-regulated apoptosis of immune organs. However, the effect of expression of death receptor and endoplasmic reticulum molecules in AFB₁-induced apoptosis of chicken splenocytes was largely unknown. The objective of this study was to investigate this unknown field. One hundred and forty four one-day-old chickens were randomly divided into control group (0 mg/kg AFB₁) and AFB₁ group (0.6 mg/kg AFB₁), respectively and fed with AFB₁ for 21 days. Histological observation demonstrated that AFB₁ caused slight congestion and lymphocytic depletion in the spleen. TUNEL and flow cytometry assays showed the excessive apoptosis of splenocytes provoked by AFB₁. Moreover, quantitative real-time PCR analysis revealed that AFB₁ induced the elevated mRNA expression of Fas, FasL, TNF-α, TNF-R₁, Caspase-3, Caspase-8, Caspase-10, Grp78 and Grp94 in the spleen. These findings suggested that AFB₁ could lead the excessive apoptosis and alter the expression of death receptor and endoplasmic reticulum molecules in chicken spleen.

Pathological Impairment, Cell Cycle Arrest and Apoptosis of Thymus and Bursa of Fabricius Induced by Aflatoxin-Contaminated Corn in Broilers

This study aimed to evaluate the comparative effects of aflatoxin-contaminated corn on the thymus and bursa of Fabricius (BF) in chickens by detecting histopathological lesions, cell cycle phase distribution and apoptosis. A total of 900 COBB500 male broilers were randomly allocated into five groups. The experiment lasted for six weeks and the five dietary treatments consisted of uncontaminated corn (control), 25% contaminated corn, 50% contaminated corn, 75% contaminated corn and 100% contaminated corn groups. The gross changes showed the decreased size of the thymus and BF, as well as the pale color of the BF in the broilers after aflatoxin contaminated diet exposure. There were more nuclear debris in the thymus and BF of birds in the 50%, 75%, and 100% contaminated corn groups, but the pathological impairments of the BF were more obvious than those of the thymus, which showed as more obvious lymphocyte depletion and the proliferation of reticulocytes and fibroblasts. At 21 days of age, the percentage of thymocytes and BF cells in the G2M phase was increased in a dose-dependent manner in the four AFB-contaminated corn groups. However, at 42 days of age, dietary AFB₁ induced cell cycle perturbation at the G0G1 phase in thymocytes, but at the G2M phase in BF cells. The increased percentage of apoptotic cells in the thymus and BF were similarly observed in the AFB groups. According to these results, the severity of histopathological lesions may be correlated with the different sensitivity of the two central immune organs when exposed to AFB; different arrested cell cycle phases suggest that different mechanisms may be involved in the lesions of the thymus and BF, which need to be further researched.

Induction of mitochondria-mediated apoptosis and PI3K/Akt/ mTOR-mediated autophagy by aflatoxin B2 in hepatocytes of broilers

Aflatoxins have been shown to induce hepatotoxicity in animal models, but the effects of aflatoxin B2 (AFB2) on broiler hepatocytes is unclear. This study aimed to investigate the effects of AFB2 on apoptosis and autophagy to provide an experimental basis for understanding the mechanism of aflatoxin-induced hepatotoxicity. One hundred-twenty Cobb500 broilers were allocated to four groups and exposed to 0 mg/kg, 0.2 mg/kg, 0.4 mg/kg, and 0.8 mg/kg of AFB2 per day for 21 d. AFB2 exerted potent proapoptotic and proautophagic effects on hepatocytes, with increased numbers of apoptotic and autophagic hepatocytes.Poly ADP-ribose polymerase (PARP) was cleaved and caspase-3 was activated in experimental groups, showing that the apoptosis of hepatocytes was triggered by AFB2. Increased levels of the autophagy factors Beclin-1 and LC3-II/LC3-I, as well as down-regulation of p62, a marker of autophagic flux, provided additional evidence for AFB2-triggered autophagy. AFB2 induced mitochondria-mediated apoptosis via the production of reactive oxygen species (ROS) and promotion of the translocation of Bax and cytochrome c (cyt c) between mitochondria and the cytosol, triggering the formation of apoptosomes. AFB2 also inhibited the phosphoinositide 3-kinase/Akt/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway by activating PI3K, Akt, and mTOR and inhibiting their phosphorylation, contributing to the proautophagic activity of AFB2. These findings provide new insights into the mechanisms involved in AFB2-induced hepatotoxicity in broilers.