Effect of selenium supplementation on aflatoxin B₁-induced histopathological lesions and apoptosis in bursa of Fabricius in broilers

Rutin Nanoparticles Alleviate Cadmium-Induced Oxidative and Immune Damage in Broilers' Bursa of Fabricius via Modulating Hsp70/TLR4/NF-κB Signaling Pathway

Cadmium (Cd) is a serious environmental pollutant affecting various tissues/organs in broilers and compromising their immunological function and productivity. Therefore, the current study aimed to investigate Cd-induced immunotoxicity and potential immunoprotective effect of rutin nanoparticles (RNPs) in the bursal tissue of broilers. A total number of 150 chicks from the Hubbard breed were randomly divided into 5 groups. Group I was fed on standard basal diet (SD) with normal drinking water (DW), Group II received SD containing RNPs (50 mg/kg feed) with DW, Group III fed on SD and DW containing Cd (150 mg/L), Group IV co-treated with rutin-enforced SD (50 mg/kg diet) and DW containing Cd (150 mg/L), and finally, Group V co-supplemented with RNP-enhanced SD (50 mg/kg diet) DW containing Cd (150 mg/L). Productive performance, economic efficiency, oxidative biomarkers, histopathological changes, and the expression level of TLR-4, HSP-70, caspase 3, NF-κB, Bcl-2, and Bax were assessed in the BF tissue. Cd led to severe production and economic losses in exposed birds with a marked surge of oxidative biomarkers, pro-inflammatory cytokines, and histopathological changes in the bursal tissue which could be explained through upregulation of the Hsp70/TLR4/NF-κB molecular pathway in the BF tissue. Meanwhile, RNPs could alleviate most of these changes and prevail optimistic immunomodulatory properties which subsequently could enhance broilers' productivity when incorporated in their diets.

Investigation of a multicomponent mycotoxin detoxifying agent for aflatoxin B1 and ochratoxin A-induced blood profile in broiler chickens

Background and Aim

Mycotoxins such as aflatoxin B1 and ochratoxin A (OTA) are secondary metabolites in molds that grow in raw materials or commercial feed. This interaction has a synergistic effect on mortality, body weight, feed intake, embryo abnormalities, egg production, and lymphoid organ atrophy. This study was conducted to determine the effect of a mycotoxin detoxifier on the blood profile of broilers that were given feed contaminated with mycotoxin, such as the number of heterophils, lymphocytes, monocytes, mean corpuscular hemoglobin (MCH), and MCH concentration (MCHC).

Materials and Methods

A total of 20 day-old chicks (DOC) of Cobb broilers were given four treatments with five replicates. The number of chickens used in this research was determined using statistical calculations, and the data obtained was homogeneous so that the population was represented. Treatments included negative control with basal feed (C-), positive control with mycotoxins contamination (C+), treatment 1: Mycotoxins contamination and mycotoxin detoxification 1.1 g/kg (T1), and treatment 2: Mycotoxins contamination and mycotoxin detoxification 1.6 g/kg (T2). Mycotoxin contamination comprised 0.1 mg/kg aflatoxin B1 and 0.1 mg/kg OTA. The treatment period for chickens was 28 days, from 8 to 35 days. A battery cage was used in this study. Chickens were kept in a closed, ventilated room and the room temperature (27°C) was monitored during the treatment period.

Results

Based on the results of statistical data processing, a significant difference (p < 0.05) was observed between chickens fed mycotoxin-contaminated feed (C+) and chickens not fed mycotoxin-contaminated feed (C-) and chickens given 1.6 g/kg mycotoxin detoxification (T2). Mycotoxin detoxification at a dose of 1.6 g/kg had a significant (p < 0.05) effect on the heterophil, lymphocyte, and heterophil lymphocyte ratio, leukocyte, erythrocyte, and hemoglobin levels of the blood broiler in this experiment. On other parameters such as monocytes, MCH, and MCHC, treatment 2 at dose 1.6 g/kg was the best treatment, although there was no significant effect with C- and T1.

Conclusion

The administration of mycotoxin detoxifiers at a dose of 1.6 g/kg increased the number of heterophils and the ratio of heterophil lymphocytes, leukocytes, erythrocytes, and hemoglobin in broilers fed mycotoxin-contaminated feed.

Selenium mitigates methotrexate-induced testicular injury: Insights from male NMRI mice model

BACKGROUND AND AIM

Chemotherapy, particularly with methotrexate (MTX), often elicits testicular toxicity, leading to impaired spermatogenesis and hormone imbalances. This study aimed to investigate the potential protective effects of selenium (Se) against MTX-induced testicular injury.

MATERIALS AND METHODS

Male mice were divided into control, MTX, Se, and MTX + Se groups. Histopathological examination involved the preparation of testicular tissue sections using the Johnsen's tubular biopsy score (JTBS) for spermatogenesis evaluation. Biochemical tests included the assessment of testosterone, malondialdehyde (MDA), luteinizing hormone (LH), and follicle-stimulating hormone (FSH) levels. Real-time quantitative polymerase chain reaction (RT-qPCR) was employed to analyze the expression of caspase 3 (casp3), tumor protein 53 (p53), B-cell lymphoma 2 (Bcl2), and Bcl2-associated X protein (Bax) genes. Statistical analysis was performed using ANOVA and Tukey's tests (p < .05).

RESULTS

Histopathological analysis revealed significant testicular damage in the MTX group, with decreased spermatogenesis and Leydig cell count, while Se administration mitigated these effects, preserving the structural integrity of the reproductive epithelium. Biochemical analysis demonstrated that MTX led to elevated malondialdehyde (MDA) levels and reduced testosterone, LH, and FSH levels, suggesting oxidative stress and Leydig cell dysfunction. Gene expression analysis indicated that MTX upregulated proapoptotic genes (casp3, p53, and bax) while downregulating the antiapoptotic Bcl2 gene. In contrast, Se treatment reversed these trends, highlighting its potential antiapoptotic properties.

CONCLUSION

Our findings underscore the potential of Se as a therapeutic agent to mitigate the reproductive toxicity associated with MTX-induced testicular injury. Se exerts protective effects by regulating oxidative stress, preserving hormone balance, and modulating apoptotic pathways. These results suggest that Se supplementation could be a promising strategy to alleviate chemotherapy-induced testicular damage and preserve male fertility.

Aflatoxin B1 induces infertility, fetal deformities, and potential therapies

Aflatoxin B1 (AFB1) is a subsidiary poisonous metabolite, archetypally spawned by Aspergillus flavus and A. parasiticus, which are often isolated in warm or tropical countries across the world. AFB1 is capable of disrupting the functioning of several reproductive endocrine glands by interrupting the enzymes and their substrates that are liable for the synthesis of various hormones in both males and females. In men, AFB1 is capable of hindering testicular development, testicular degeneration, and reduces reproductive capabilities. In women, a direct antagonistic interaction of AFB1 with steroid hormone receptors influencing gonadal hormone production of estrogen and progesterone was responsible for AFB1-associated infertility. AFB1 is potentially teratogenic and is responsible for the development of malformation in humans and animals. Soft-tissue anomalies such as internal hydrocephalus, microphthalmia, cardiac defects, augmented liver lobes, reproductive changes, immune modifications, behavioral changes and predisposition of animals and humans to neoplasm development are AFB1-associated anomalies. Substances such as esculin, selenium, gynandra extract, vitamins C and E, oltipraz, and CDDO-Im are potential therapies for AFB1. Thus, this review elucidates the pivotal pathogenic roles of AFB1 in infertility, fetal deformities, and potential therapies because AFB1 toxicity is a key problem globally.

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.

Nano-Sized Selenium Maintains Performance and Improves Health Status and Antioxidant Potential While Not Compromising Ultrastructure of Breast Muscle and Liver in Chickens

The poultry industry is looking for the most effective sources of selenium (Se) for commercial use. Over the past five years, nano-Se has attracted a great deal of attention in terms of its production, characterisation and possible application in poultry production. The objective of this study was to evaluate the effects of dietary levels of inorganic and organic Se, selenised yeast and nano forms of selenium on breast meat quality, liver and blood markers of antioxidants, the ultrastructure of tissue and the health status of chickens. A total of 300 one-day-old chicks Ross 308 were divided into 4 experimental groups, in 5 replications, with 15 birds per replication. Birds were fed the following treatments: a standard commercial diet containing inorganic Se in the form of inorganic Se at the level of 0.3 mg/kg diet and an experimental diet with an increased level of Se (0.5 mg/kg diet). The use of other forms of Se (nano-Se) versus sodium selenate significantly influences (p ≤ 0.05) a higher collagen content and does not impair physico-chemical properties in the breast muscle or the growth performance of the chickens. In addition, the use of other forms of selenium at an increased dose versus sodium selenate affected (p ≤ 0.01) the elongation of sarcomeres in the pectoral muscle while reducing (p ≤ 0.01) mitochondrial damage in hepatocytes and improving (p ≤ 0.05) oxidative indices. The use of nano-Se at a dose of 0.5 mg/kg feed has high bioavailability and low toxicity without negatively affecting the growth performance and while improving breast muscle quality parameters and the health status of the chickens.

Epigallocatechin Gallate and Glutathione Attenuate Aflatoxin B1-Induced Acute Liver Injury in Ducklings via Mitochondria-Mediated Apoptosis and the Nrf2 Signalling Pathway

Aflatoxin B1 (AFB1) exists widely in feed and food with severe hazards, posing a serious threat to human and animal health. Epigallocatechin gallate (EGCG) and glutathione (GSH) have been reported as having anti-oxidative and other functions. The present study aimed to investigate the detoxification effect of EGCG and GSH alone or in combination on AFB1 exposure in ducklings. Fifty one-day-old male ducklings were randomly assigned into five experimental groups (n = 10): 1. Control (CTR); 2. 0.3 mg/kg BW AFB1 (AFB1); 3. 0.3 mg/kg BW AFB1 + 100 mg/kg BW EGCG (AFB1 + EGCG); 4. 0.3 mg/kg BW AFB1 + 30 mg/kg BW GSH (AFB1 + GSH); 5. 0.3 mg/kg BW AFB1 + 100 mg/kg BW EGCG + 30 mg/kg BW GSH (AFB1 + EGCG + GSH). The experiment lasted for seven days. Compared with the CTR group, AFB1 reduced growth performance, total serum protein and albumin content, increased serum enzyme activity (alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and γ-glutamyl transpeptidase), and caused pathological damage to the ducklings' livers. AFB1 exposure increased malondialdehyde content and decreased superoxide dismutase, total antioxidant capacity, catalase, glutathione peroxidase activities, and glutathione content in the liver. EGCG and GSH alone or in combination mitigated these adverse effects. Meanwhile, EGCG and GSH attenuate apoptosis of hepatocytes, and regulated AFB1-induced changes in the abundance of genes contained in the Keap1/Nrf2 signalling and apoptotic pathways. Collectively, these results suggest that EGCG and GSH alleviate the hepatocyte injury induced by AFB1 by inhibiting oxidative stress and attenuating excessive mitochondria-mediated apoptosis.

Effect of Azomite on growth performance, immune function and tibia breaking strength of broiler chickens during starter period

This study was examined to investigate the effect of Azomite (AZO) on the growth performance, immune function, and bone mineralization of broiler chickens. A total of 240-d old male chicks were randomly assigned into four treatments with six replicates (n = 10), which included control (basal diet), basal diet +0.25% AZO, basal diet + 0.50% AZO and basal diet + kitasamycin as antibiotic growth promoter (AGP). The results indicate that live body weight (LBW), average daily gain (ADG) and feed conversion ratio (FCR) were significantly (p < .05) improved in AZO 0.25% and 0.50% than the control. The weight of bursa of Fabricus was significantly (p < .05) higher in AZO-0.25% and AZO-0.50% than control. Total protein (TP), globulin, IgA and IgG levels were significantly (p < .05) increased with AZO supplemented treatments. Tibia diameter tibia breaking strength was significantly (p < .05) increased in AZO- 0.25% and AZO-0.50% treatment. In conclusion, the results indicated that addition of AZO at the doses of 0.25% and 0.50% in the diet had beneficial effects on growth performance, immune functions and tibia breaking strength.

Effect of Curcumin as Feed Supplement on Immune Response and Pathological Changes of Broilers Exposed to Aflatoxin B1

In this study, we examined the protective effects of curcumin against the AFB1-induced immune response of and pathological changes in broilers. Histopathology examinations showed that at day 28, AFB1 (5 mg/kg) exposure leads to severe histological changes in the spleen, thymus and bursa of Fabricius with a decrease in the number and karyoplasmic area ratio of plasma cells. Curcumin alleviated the AFB1-induced immune organs’ damage as well as the changes in plasma cells in a dose-dependent manner. RT-PCR data showed that AFB1 significantly downregulated the IL-2 and IFN-γ mRNA expression levels in the thymus, spleen and bursa of Fabricius. However, curcumin supplementation improved the AFB1-induced immune organs’ damage via upregulated cytokines’ expression. Intriguingly, similar trends were noticed in abnormal morphological changes and the immune response at day 35 after the withdrawal of AFB1 and curcumin from the diet, suggesting the protective effects and immunomodulatory function against AFB1 in broilers. The current study provides a scientific experimental basis for the application of curcumin as a therapeutic drug or additive in animal husbandry productive practice.

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.

Effects of Chinese Gallnut Tannic Acid on Growth Performance, Blood Parameters, Antioxidative Status, Intestinal Histomorphology, and Cecal Microbial Shedding in Broilers Challenged with Aflatoxin B1

The objective of the present study was to investigate the effects of tannic acid (TA) on growth performance, blood parameters, antioxidant capacity, and intestinal health in broilers challenged with aflatoxin B1 (AFB1). A total of 480 1-d-old broilers were randomly allotted into 4 treatments: 1) CON, control diet, 2) AF, CON + 60 μg/kg AFB1 of feed during d 1 to 21, CON + 120 μg/kg AFB1 of feed during d 22 to 42, 3) TA1, AF +250 mg/kg TA, 4) TA2, AF +500 mg/kg TA. Average daily gain (ADG) and average daily feed intake (ADFI) were increased in the TA1 during d 1 to 21, d 22 to 42 and d1 to 42 compared with CON and AF treatments (P < 0.05). Broilers fed the TA2 diet had greater ADG and ADFI than those fed the CON and AF diets during the finisher and the whole period (P < 0.05). Administration of TA decreased the relative weight of liver and kidney compared with broilers fed the AF diet on d 42 (P < 0.05). The blood activity of alanine transferase (ALT) and gamma-glutamyl transferase (GGT) was increased in the AF treatment compared with the CON (P < 0.05). Broilers fed the TA1 decreased the ALT content on d 21, and the level of ALT and GGT was decreased in the TA2 compared with the AF group on d 42 (P < 0.05). The activity of total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) in plasma, and the hepatic glutathione S-transferase (GST) was decreased in the AF group compared with the CON group (P < 0.05). The TA decreased plasma malondialdehyde concentration, and increased plasma T-SOD, GSH-Px, total antioxidant capacity, and hepatic GST activity compared to the AF (P < 0.05). The crypt depth of jejunum was decreased in the TA1 treatment on d 21, and the villus height of ileum was increased in the TA2 group on d 42 compared with the AF treatment (P < 0.05). The cecal Lactobacillus counts on d 21 was tended to increase in the TA treatments compared with the AF (P = 0.061). In conclusion, dietary inclusion of 250 mg/kg and 500 mg/kg TA could improve the growth, antioxidant capacity, and partially protected the intestinal health of broilers challenged with AFB1.

The preventive effect and mechanisms of adsorbent supplementation in low concentration aflatoxin B1 contaminated diet on subclinical symptom and histological lesions of broilers

This study aimed to investigate the subclinical symptom and histological lesions of 21-day-old and 42-day-old broilers exposure to low concentration aflatoxin B1 (AFB1), and the preventive effect with adsorbent (Toxo-MX) supplementation. A total of 576 one-day-old Arbor Acres broilers were randomly allotted into 6 treatments 8 replicates and 12 birds per cage, fed with 0 ppb, 60 ppb and 120 ppb AFB1 contamination diet with or without Toxo-MX supplementation. Results showed both 60 ppb and 120 ppb AFB1 contamination significantly reduced growth performance in 21-day-old broilers (P < 0.05), but not in 42-day-old broilers (P > 0.05), however, AFB1 contamination in diet caused a higher feed to gain ratio (P < 0.05). Broilers of 21-day-old exposure to 60 ppb and 120 ppb AFB1 increased mRNA expression of hepatic inflammatory cytokines, and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) activity (P < 0.05), 42-day-old broilers showed a same change in 120 ppb but not in 60 ppb of AFB1 contamination (P < 0.05). mRNA expressions of clauding-1, Zonula occludens-1 (ZO-1), and occludin decreased, but Bax, Bcl-2, and caspase-3 increased in 21-day-old broilers exposure to 60 ppb and 120 ppb AFB1 (P < 0.05), broilers of 42-day-old resisted on intestinal aflatoxicosis impairment against 60 ppb AFB1 contamination (P < 0.05), but not in 120 ppb (P < 0.05). Toxo-MX supplementation significantly reversed the detrimental effects on growth performance in both age broilers and reduced the accelerated feed to gain ratio caused by AFB1 (P < 0.05). Intestinal mRNA expression of tight junction and apoptotic genes in both age broilers were recovered by Toxo-MX supplementation (P < 0.05). However, Toxo-MX did not restore the accelerated expression of hepatic inflammation cytokines and SOD, GSH-Px in 120ppb AFB1 group (P < 0.05). The data demonstrated that diet supplementation with Toxo-MX reversed the detrimental effect on growth performance and intestine in broilers exposure to 60 ppb and 120 ppb AFB1. However, did not completely recovered hepatic inflammation induced by AFB1.

Penthorum Chinense Pursh Extract Alleviates Aflatoxin B1-Induced Liver Injury and Oxidative Stress Through Mitochondrial Pathways in Broilers

Aflatoxin is an important toxicant of the fungal origin and poses a threat to the poultry industry. This study was designed to reveal the underlying mechanism and protective methods against aflatoxin B1 (AFB1)-induced liver injury, oxidative stress, and apoptosis using a Traditional Chinese medicine, Penthorum chinense Pursh extract (PCPE), in broilers. A total of 164 (day-old) broilers were equally allocated to the control, AFB1 (3 mg/kg feed), positive drug (Yin-Chen-Hao Tang extract, 10 ml/kg feed), PCPE (2 g PCPE/kg), and PCPE low, medium, and high dose groups (1 g, 2 g, 3 g PCPE/kg feed, respectively). AFB1 significantly decreased the growth performance and serum immunoglobulin level, altered normal serum biochemical parameters and antioxidant activities, and induced histopathological lesions in the liver as compared to control group. Additionally, AFB1 significantly up-regulated the mRNA expression levels of apoptosis-related genes such as Bax, Bak, caspase-9, caspase-3, and p53, whereas it down-regulated the expression levels of BCL2 in the liver of broilers. The supplementation of different doses of PCPE to AFB1-affected birds significantly eased AFB1 negative effects by improving growth performance, immunoglobulin level, and oxidative capacity, and reversed oxidative stress and pathological lesions in liver. Furthermore, supplementation of PCPE to the AFB1 group reversed apoptosis by significantly down-regulating the mRNA expression levels of Bax, Bak, caspase-9, caspase-3, and p53 and up-regulating the expression levels of BCL2 in the liver of broilers. Based on these results, we conclude that supplementation of PCPE is protective and safe against oxidative stress, is anti-apoptotic, and reverses the liver damage caused by AFB1 in broilers.

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.

Selenium and the health status, production results, and product quality in poultry

A Selenium (Se) is an element belonging to the nonmetallic group. It was first discovered in 1817 by J.J. Berzelius. Until the 1950s, it was considered to be toxic to animals. However, with increasing research conducted on laboratory animals, it is now clear that Se is necessary for the proper functioning of both plants and animals. Recent studies indicate that Se is necessary for the proper functioning of metabolic pathways in animals. It was evidenced that Se is a component of about 100 proteins involved in the immune system, antioxidant homeostasis, or release of an inflammatory mediator. Therefore, it is of key interest to find the appropriate dosage for the supplementation of Se in the diet of farm animals and thereby eliminate physiological disorders in the body associated with Se imbalance. In this study, we present a literature review on the importance and appropriate dosage of Se in the diet of poultry concerning their health status, production results, and the quality of animal-origin products.

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

Background

Dietary selenium (Se), as an antioxidant element, plays a protective role in aflatoxin B₁ (AFB₁) toxicosis in poultry.

Objectives

To compare the effects of sodium selenite (SS) and Se nanoparticles (SeNPs) against AFB₁‐induced toxicity on growth performance, carcass traits, immune response, antioxidant status and serum lipid concentrations in Japanese broiler quails.

Methods

A total of 540 quails were divided into six treatments, each with six replicates and 15 birds per replicate at 24 days of age and reared for 21 days. Treatments included: (1) a basal diet without Se and AFB₁ (negative control; NC); (2) NC + 1.0 mg/kg AFB₁ (positive control; PC); (3) PC + 0.2 mg/kg Se as SS; (4) PC + 0.5 mg/kg Se as SS; (5) PC + 0.2 mg/kg Se as SeNPs; and (6) PC + 0.5 mg/kg Se as SeNPs.

Results

Treatment with PC diet decreased feed intake and body weight gain and increased feed conversion ratio than the NC diet. The PC diet also atrophied the lymphoid organs and depressed antibody responses against Newcastle disease and avian influenza viruses and sheep red blood cell. Moreover, quails treated with PC diet appeared to have lower serum glutathione peroxidase and thioredoxin reductase activities and disturbed serum lipids than those receiving the NC diet. Dietary Se attenuated these detrimental effects, but failed to completely eliminate them. Additionally, SeNPs performed better than SS in improving thioredoxin reductase activity and antibody titer against sheep red blood cell.

Conclusions

Diet supplementation with SeNPs to provide 0.5 mg/kg of Se is recommended to reduce the AFB₁ toxicosis in broiler quails.

Protective effects of selenium on acrylamide-induced neurotoxicity and hepatotoxicity in rats

Objective(s):

Acrylamide (ACR), has wide uses in different industries. ACR induced several toxicities including neurotoxicity and hepatotoxicity. The probable protective effects of selenium on ACR-induced neurotoxicity and hepatotoxicity in rats were evaluated.

Materials and Methods:

Male Wistar rats were studied for 11 days in 8 groups: 1. Control, 2. ACR (50 mg/kg, IP), 3-5. ACR+ selenium (0.2, 0.4, 0.6 mg/kg, IP), 6. ACR+ the most effective dose of selenium (0.6 mg/kg, IP) three days after ACR administration, 7. ACR+ vitamin E (200 mg/kg IP, every other day) 8. Selenium (0.6 mg/kg IP). Finally, behavioral tests were done. The levels of malondialdehyde (MDA), glutathione (GSH), Bcl-2, Bax and caspase 3 proteins in liver and cerebral cortex tissues were measured. Also, the amount of albumin, total protein, alanine transaminase (ALT) and aspartate transaminase (AST) enzymes were determined in serum.

Results:

ACR caused the severe motor impairment, increased MDA level and decreased GSH content, enhanced Bax/Bcl-2 ratio and caspase 3 proteins in brain and liver tissues. Besides, the level of AST was elevated while the total serum protein and albumin levels were decreased. Administration of selenium (0.6 mg/kg) (from the first day of the experiment and the third day) significantly recovered locomotor disorders, increased GSH content, and reduced MDA level. Also, selenium decreased Bax/Bcl-2 ratio and caspase 3 levels in brain and liver tissues.

Conclusion:

The oxidative stress and apoptosis pathways have important roles in neurotoxicity and hepatotoxicity of ACR. Selenium significantly reduced ACR-induced toxicity through inhibition of oxidative stress and apoptosis.

Selenium mitigated aflatoxin B1-induced cardiotoxicity with potential regulation of 4 selenoproteins and ferroptosis signaling in chicks

The aim of the present study was to explore the underlying mechanism of selenium (Se)-mediated detoxification of aflatoxin B₁ (AFB₁)-induced cardiotoxicity in chicks. A Se-deficient, corn-soybean meal-basal diet (36 μg Se/kg, BD) and three test diets (BD+1.0 mg AFB₁/kg, 0.3 mg Se/kg, or 1.0 mg AFB₁/kg+0.3 mg Se/kg) were used in a 3-wk 2 × 2 factorial design trial (n = 30 chicks/group). Dietary AFB₁ led to induced (P < 0.05) serum creatine kinase and creatine kinase MB isoenzyme activities and heart histopathologic lesions. However, Se deficiency aggravated most of these alterations induced by AFB₁. Moreover, mRNA levels of two ferroptosis activators (solute carrier family 11 Member 2 and transferrin) were upregulated (P < 0.05) in the AFB₁-treated groups. Additionally, Se deficiency reduced (P < 0.05) glutathione peroxidase (GPX) 3 and thioredoxin reductase 3 mRNA and GPX activity but increased (P < 0.05) selenoprotein M and selenophosphate synthetase 2 mRNA in the heart in AFB₁-administered groups. The in vitro study showed that Se alleviated (P < 0.05) AFB₁-reduced cell viability and induced (P < 0.05) ROS and ferroptosis in H9C2 cardiac cells. It also downregulated (P < 0.05) two ferroptosis activators (long-chain acyl-CoA synthetase 4 and solute carrier family 11 Member 2) in the AFB₁-treated groups in the H9C2 cells. In conclusion, this study illustrated that Se alleviates AFB₁-induced cardiotoxicity and cardiomyocyte damage potentially related to the regulation of redox status, 4 selenoproteins, and ferroptosis-related signaling.

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.

Supplementation of Selenium Nanoparticles-Loaded Chitosan Improves Production Performance, Intestinal Morphology, and Gut Microflora in Broiler Chickens

The current study aimed to evaluate the efficacy of selenium nanoparticles (SeNPs), combined or loaded with chitosan (COS), in broiler chickens reared under standard management protocols. The parameters under investigation were production performance, organ development, components of the intestinal barrier, and ileal microbial count. Two hundred and forty day-old chicks were raised in five groups, with each group containing eight replicates (n=6/replicate). The control group received a basal diet whereas the other four groups received basal diets supplemented with SeNPs (0.5 mg/kg), COS (200 mg/kg), SeNPs+COS (0.5 mg/kg SeNPs + 200 mg/kg COS), and SeNPs-loaded COS (SeNPs-L-COS) (200 mg/kg) respectively. On day 35, two birds/replicate were sampled to collect the viscera under investigation. The results revealed that dietary inclusion of SeNPs-L-COS increased (p<0.05) the body weight gain and improved (p<0.05) feed conversion ratio. Similarly, SeNPs-L-COS supplementation increased (p<0.05) the small intestinal villus surface area as well as the count of acidic goblet cells and intraepithelial lymphocytes when compared with the control group. Whereas the total goblet cell count was higher (p<0.05) in the small intestines of both the SeNPs+COS and SeNPs-L-COS groups. Microbial analysis of ileal contents also revealed an increase (p<0.05) in Lactobacilli species count with a concurrent decrease (p<0.05) in Escherichia coli count in the SeNPs-L-COS group when compared with the COS and control groups. Based on the results of the current trial, we can conclude that supplementation with SeNPs-L-COS is a superior combination for promoting the gut health and performance of broilers.

Effect of dietary raw and fermented sour cherry kernel (Prunus cerasus L.) on growth performance, carcass traits, and meat quality in broiler chickens

Sour cherry kernels are waste products of the fruit juice industry. Solid-state fermentation has great potential for recycling the agro-industrial residues. In the present study, the effect of raw sour cherry kernel (RC) and fermented sour cherry kernel (FC) by Aspergillus niger on growth performance, carcass traits and meat quality in broiler chickens was investigated. A total of 343 one-day-old male broilers (Ross 308) were randomly allocated to 7 treatments with 7 replicates for each treatment and 7 birds in each replicate. The chicks were fed on a basal diet (control) and basal diet supplemented with RC or FC at the 1, 2, and 4% level. Dietary RC improved (P < 0.001) the feed conversion ratio (FCR) at the 1% inclusion level although chicks fed 2 and 4% RC had lower (P < 0.01) body weight (BW), body weight gain (BWG), and feed intake (FI) from day 1 to 42, compared with that of the birds in the control group. Dietary FC with 1% inclusion level increased (P ≤ 0.05) BWG from day 22 to 42 and also enhanced (P < 0.001) the FCR from day 1 to 42. However, 4% dietary FC had an adverse effect (P < 0.01) on BW, BWG, FI, and the FCR, compared with the control group. The bursa of Fabricius weight was raised (P < 0.01) as the supplemental FC level increased. Dietary RC and FC elevated gut weight (P < 0.01) and length (P ≤ 0.05). Broilers fed on 2% FC had a higher (P ≤ 0.05) ash level and a lower (P ≤ 0.05) b* value in thigh meat, compared with the 2% RC group. The results indicate that FC can be used in broiler nutrition up to 2% level although RC can be added to broiler diets up to 1% level without a detrimental effect on growth performance. Dietary inclusion of 1% RC or FC can be recommended due to the positive effects on broiler chickens.

The Protective Role of Selenium Against AFB1-Induced Liver Apoptosis by Death Receptor Pathway in Broilers

Aflatoxin B1 (AFB₁) is the most toxic among the mycotoxins and causes detrimental health effects on the liver of human and animals. Selenium (Se) plays an important role in protection of various animal species against numerous notorious toxic agents. The present study is designed to explore the protective effects of Se against AFB₁-induced liver pathogenesis by the methods of histopathology, flow cytometry, quantitative real-time polymerase chain reaction (qRT-PCR), and biochemical analysis. A total of 312, 1-day-old healthy Cobb-500 broilers were randomly divided into four groups and fed with basal diet (control group), 0.6 mg/kg AFB₁ (AFB₁ group), 0.4 mg/kg Se (+ Se group), and 0.6 mg/kg AFB₁ + 0.4 mg/kg Se (AFB₁ + Se group) for 21 days, respectively. Our results showed that 0.4 mg/kg Se supplement in broiler's diets could alleviate the AFB₁-induced histological lesions in the liver. The apoptosis analysis by flow cytometry showed that 0.4 mg/kg Se ameliorated the AFB₁-induced apoptosis in the liver. Moreover, the mRNA expression levels of Fas, TNF-α, FAS-associated death domain, TNF receptor-associated death domain, TNF receptor-associated factor 2, caspase 10, caspase 8, B cell lymphoma 2, IκB kinase, X-linked inhibitor of apoptosis protein, caspase 9, and caspase 3 analyzed by qRT-PCR demonstrated that 0.4 mg/kg Se could relieve the impact caused by AFB₁ to these parameters. The biochemical analyses of activities of CAT, GSH-Px and SOD, hydroxyl ion scavenging and contents of MDA and GSH in liver cells also indicated that 0.4 mg/kg Se has positive effect on AFB₁-induced oxidative stress in the liver. In conclusion, Se could relieve AFB₁-induced apoptosis by the molecular regulation of death receptors pathway in the liver of broilers. The outcomes from the present study may lead to a better understanding of the nature of selenium's essentiality and its protective roles against AFB₁.

Retrospective and Prospective Look at Aflatoxin Research and Development from a Practical Standpoint

Among the array of structurally and toxicologically diverse mycotoxins, aflatoxins have attracted the most interest of scientific research due to their high toxicity and incidence in foods and feeds. Despite the undeniable progress made in various aspects related to aflatoxins, the ultimate goal consisting of reducing the associated public health risks worldwide is far from being reached due to multiplicity of social, political, economic, geographic, climatic, and development factors. However, a reasonable degree of health protection is attained in industrialized countries owing to their scientific, administrative, and financial capacities allowing them to use high-tech agricultural management systems. Less fortunate situations exist in equatorial and sub-equatorial developing countries mainly practicing traditional agriculture managed by smallholders for subsistence, and where the climate is suitable for mould growth and aflatoxin production. This situation worsens due to climatic change producing conditions increasingly suitable for aflatoxigenic mould growth and toxin production. Accordingly, it is difficult to harmonize the regulatory standards of aflatoxins worldwide, which prevents agri-foods of developing countries from accessing the markets of industrialized countries. To tackle the multi-faceted aflatoxin problem, actions should be taken collectively by the international community involving scientific research, technological and social development, environment protection, awareness promotion, etc. International cooperation should foster technology transfer and exchange of pertinent technical information. This review presents the main historical discoveries leading to our present knowledge on aflatoxins and the challenges that should be addressed presently and in the future at various levels to ensure higher health protection for everybody. In short, it aims to elucidate where we come from and where we should go in terms of aflatoxin research/development.

Research Progress on the Toxic Antagonism of Selenium Against Mycotoxins

Animal feed is prone to becoming infected with molds during production and storage, resulting in secondary metabolite mycotoxins, such as aflatoxin B₁ (AFB₁), T-2 toxins, deoxynivalenol (DON), and ochratoxin A (OTA), which are harmful to humans and animals. Selenium is an essential trace element for humans and animals, and it is also an effective antioxidant. Many studies have shown that selenium can reduce the damage caused by mycotoxins in animals. This article reviews the current literature on the antagonistic effects of selenium on AFB₁, T-2, DON, and OTA toxicity.

The Molecular Mechanisms of Protective Role of Se on the G0/G1 Phase Arrest Caused by AFB1 in Broiler's Thymocytes

This research was designed to explore the protective effects of sodium selenite on G₀/G₁ phase arrest induced by AFB₁ in thymocytes of broilers. Two hundred eighty-eight Cobb broilers were divided into control group, + Se group (0.4 mg/kg Se), AFB₁ group (0.6 mg/kg AFB₁), and AFB₁ + Se group (0.6 mg/kg AFB₁ + 0.4 mg/kg Se). The results revealed that 0.4 mg/kg Se supplement in diets could improve the AFB₁-induced histological lesions in the thymus consisting of the more vacuoles and nuclear debris in thymic cortical area. The results of flow cytometric detect showed that 0.4 mg/kg Se relieved the G₀/G₁ phase arrest caused by AFB₁ in thymocytes. The results of transcription levels of ATM, p53, p21, p27, p15, p16, CyclinD₁, CyclinE, Cdk6, Cdk2, and PCNA genes by qRT-PC, and protein expression level of PCNA by immunohistochemistry demonstrated that 0.4 mg/kg Se could reduce the adverse effects of AFB₁ on these parameters. In conclusion, Se could relieve AFB₁-induced G₀/G₁ phase arrest by p15 (or p16)-CyclinD₁/Cdk6, ATM-p53-p21-CyclinE/Cdk2, p27-CyclinE/Cdk2 pathways.

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.

Comparative evaluation of aflatoxin and mineral binding activity of molecular imprinted polymer designed for dummy template using in vitro and in vivo models

The amelioration of aflatoxicosis in ducklings was examined by feeding molecular imprinted polymer (MIP) synthesized to target the aflatoxin B₁ (AFB₁) analog molecule [5, 7-dimethoxycoumarin (DMC)] as a smart and novel toxin binder in comparison to a commercial toxin binder (CTB). MIP was characterized with some techniques, such as scanning electron microscopy (SEM) and thermal gravimetric analysis (TGA) that showed morphology and thermal resistance of MIP, respectively. The SEM showed that more pores and big cavities were formed in the network of the MIP. TGA plots of MIP showed dehydration at temperatures of about 31 °C-200 °C and gradual decomposition until 300 °C. The in vitro and in vivo ability of MIP and CTB to adsorb some minerals (Ca, Cu, Mg, P and Zn) was evaluated. The in vivo efficacy of MIP as an aflatoxins (AFs) binder in duckling exposed to aflatoxin-contaminated feed from 4 to 18 d of age was also compared to that of the CTB. A total of 240 4-d-old ducklings were assigned to experimental diets. Each diet was replicated four times with 10 birds in each pen, and the initial body weight classes were considered as blocks. The experimental treatment diets included: 1- Control (basal diet without any additive or AFs), 2- MIP (5 g/kg diet), 3- CTB (5 g/kg diet), 4- AFs (0.2 mg/kg diet), 5- AFs + MIP (0.2 mg/kg + 5 g/kg diet), and 6- AFs + CTB (0.2 mg/kg + 5 g/kg diet). In vitro study may clearly reflect the possibility of adsorbing minerals by CTB as compared to MIP whilst the results were not confirmed by in vivo study and it seems that reduction in plasma levels of minerals is related to the adverse effects of AFs. Livers showed histopathological alterations, with bile-duct proliferation of all aflatoxin fed ducklings. Macroscopic study indicated liver of birds fed diets containing AFs showed abnormal signs including yellowish, friable and rounded shape without protective effect of MIP and CTB. The results obtained from in vivo study indicate the partial alleviation of the adverse effects of AFs in ducklings by dietary supplementation of MIP and CTB (5 g/kg) on plasma albumin, Zn, Mg and Ca.

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.

Selenium Rescues Aflatoxin B1-Inhibited T Cell Subsets and Cytokine Levels in Cecal Tonsil of Chickens

Cecal tonsil is the largest peripheral lymphoid organ of the gut-associated lymphoid tissue executing immune function. To evaluate the protective effect of selenium (Se) on the cecal tonsil of chicken exposed to aflatoxin B₁ (AFB₁), 144 1-day-old healthy Cobb chickens were randomly divided into four groups, and fed with basal diet (control group), 0.6 mg/kg AFB₁ (AFB₁ group), 0.4 mg/kg Se supplement (+Se group), and 0.6 mg/kg AFB₁ + 0.4 mg/kg Se supplement (AFB₁ + Se group) for 21 days, respectively. The results showed that AFB₁ significantly decreased the percentages of CD3⁺, CD3⁺CD4⁺, CD3⁺CD8⁺ T cells, and the CD4⁺/CD8⁺ ratio, and suppressed the expressions of IL-2, IL-4, TNF-α, and IFN-γ mRNA in the cecal tonsil. However, Selenium (Se) supplied in the diets restored the percentages of T cell subsets, the CD4⁺/CD8⁺ ratio, and mRNA expressions of cytokines in the AFB₁ group to be close to those in the control group, and did not exhibit obvious toxicity to the cecal tonsil. These results indicated that Se exerted protective effect against AFB₁ on the functions of cecal tonsil, and also partially uncovered a new role of Se that could protect cecal tonsil of chickens from immunotoxicity of AFB₁.

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.

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.

Ameliorative effects of selenium on the excess apoptosis of the jejunum caused by AFB1 through death receptor and endoplasmic reticulum pathways

Aflatoxin B1 (AFB1), one of most potent and common mycotoxins in human food and animal feed, has hepatotoxic and carcinogenic effects on humans and poultry. Recent studies indicated that selenium (Se) has a protective effect on apoptosis induced by toxin poisoning. The present study was designed to reveal the ameliorative effects of selenium on the expression of apoptosis related molecules in the jejunum of broilers exposed to an AFB1 diet for 3 weeks. A total of 216 one-day-old healthy Cobb broilers were randomly divided into the control group (0 mg kg-1 AFB1), AFB1 group (0.6 mg kg-1 AFB1), AFB1 + Se group (0.6 mg kg-1 AFB1 + 0.4 mg kg-1 supplement Se) and Se group (0.4 mg kg-1 supplement Se), respectively. TUNEL and flow cytometry assays both indicated that 0.4 mg kg-1 selenium could ameliorate excess apoptosis caused by AFB1 in jejunal cells. Moreover, the expressions of FAS, FASL, TNF-α, TNF-R1, CASPASE-3, CASPASE-8, CASPASE-10, GRP78 and GRP94 analyzed by qRT-PCR demonstrated that 0.4 mg kg-1 selenium restored these parameters to be close to those in the control group. In summary, supplementation of selenium at a concentration of 0.4 mg kg-1 selenium could protect the chicken's jejunum from excess apoptosis caused by 0.6 mg kg-1 AFB1 through down-regulating the expression of death receptor pathway and endoplasmic reticulum pathway related molecules. According to this conclusion, this study may contribute to a better understanding of selenium's protective role against AFB1 poisoning.

The Protective Role of Selenium in AFB1-Induced Tissue Damage and Cell Cycle Arrest in Chicken's Bursa of Fabricius

Aflatoxin B₁ (AFB₁) is a naturally occurring secondary metabolites of Aspergillus flavus and Aspergillus parasiticus, and is the most toxic form of aflatoxins. Selenium (Se) with antioxidant and detoxification functions is one of the essential trace elements for human beings and animals. This study aims to evaluate the protective effects of Se on AFB₁-induced tissue damage and cell cycle arrest in bursa of Fabricius (BF) of chickens. The results showed that a dietary supplement of 0.4 mg·kg^-1 Se alleviated the histological lesions induced by AFB₁, as demonstrated by decreasing vacuoles and nuclear debris, and relieving oxidative stress. Furthermore, flow cytometry studies showed that a Se supplement protected AFB₁-induced G₂M phase arrest at 7 days and G₀G₁ phase arrest at 14 and 21 days. Moreover, the mRNA expression results of ATM, Chk2, p53, p21, cdc25, PCNA, cyclin D₁, cyclin E₁, cyclin B₃, CDK6, CDK2, and cdc2 indicated that Se supplement could restore these parameters to be close to those in the control group. It is concluded that a dietary supplement of 0.4 mg kg^-1 Se could diminish AFB₁-induced immune toxicity in chicken's BF by alleviating oxidative damage and cell cycle arrest through an ATM-Chk2-cdc25 route and the ATM-Chk2-p21 pathway.

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.

Protective and Detoxifying Effects Conferred by Dietary Selenium and Curcumin against AFB1-Mediated Toxicity in Livestock: A Review

Aflatoxin B1 (AFB1), among other aflatoxins of the aflatoxin family, is the most carcinogenic and hazardous mycotoxin to animals and human beings with very high potency leading to aflatoxicosis. Selenium is an essential trace mineral possessing powerful antioxidant functions. Selenium is widely reported as an effective antioxidant against aflatoxicosis. By preventing oxidative liver damage, suppressing pro-apoptotic proteins and improving immune status in AFB1 affected animals; selenium confers specific protection against AFB1 toxicity. Meticulous supplementation of animal feed by elemental selenium in the organic and inorganic forms has proven to be effective to ameliorate AFB1 toxicity. Curcumin is another dietary agent of importance in tackling aflatoxicosis. Curcumin is one of the major active ingredients in the tubers of a spice Curcuma longa L., a widely reported antioxidant, anticarcinogenic agent with reported protective potential against aflatoxin-mediated liver damage. Curcumin restricts the aflatoxigenic potential of Aspergillusflavus. Curcumin inhibits cytochrome P450 isoenzymes, particularly CYP2A6 isoform; thereby reducing the formation of AFB1-8, 9-epoxide and other toxic metabolites causing aflatoxicosis. In this review, we have briefly reviewed important aflatoxicosis symptoms among animals. With the main focus on curcumin and selenium, we have reviewed their underlying protective mechanisms in different animals along with their extraction and production methods for feed applications.

The Molecular Mechanisms of Protective Role of Se on the G2/M Phase Arrest of Jejunum Caused by AFB1

Aflatoxin B₁ (AFB₁) is the most toxic among the mycotoxins and causes detrimental health effects on human and animals. Selenium (Se) plays an important role in chemopreventive, antioxidant, anticarcinogen, and detoxification and involved in cell cycle regulation. The aim of this study was to explore the molecular mechanisms of selenium involved in inhibition of G₂/M cell cycle arrest of broiler's jejunum. A total of 240 one-day-old healthy Cobb broilers were randomly divided into four groups and fed with basal diet (control group), 0.6 mg/kg AFB₁ (AFB₁ group), 0.4 mg/kg Se (+Se group), and 0.6 mg/kg AFB₁ + 0.4 mg/kg Se (AFB₁ + Se group) for 21 days, respectively. The histological observation and morphological analysis revealed that 0.4 mg/kg Se prevented the AFB₁-associated lesions of jejunum including the shedding of the apical region of villi, the decreased villus height, and villus height/crypt ratio. The cell cycle analysis by flow cytometry showed that 0.4 mg/kg Se ameliorated the AFB₁-induced G₂/M phase arrest in jejunal cells. Moreover, the expressions of ATM, Chk2, p53, Mdm2, p21, PCNA, Cdc25, cyclin B, and Cdc2 analyzed by immunohistochemistry and qRT-PCR demonstrated that 0.4 mg/kg Se restored these parameters to be close to those in the control group. In conclusion, Se promoted cell cycle recovery from the AFB₁-induced G₂/M phase arrest by the molecular regulation of ATM pathway in the jejunum of broilers. The outcomes from the present study may lead to a better understanding of the nature of selenium's essentiality and its protective roles against AFB₁.

Ameliorative Effects of Grape Seed Proanthocyanidin Extract on Growth Performance, Immune Function, Antioxidant Capacity, Biochemical Constituents, Liver Histopathology and Aflatoxin Residues in Broilers Exposed to Aflatoxin B₁

Aflatoxicosis is a grave threat to the poultry industry. Dietary supplementation with antioxidants showed a great potential in enhancing the immune system; hence, protecting animals against aflatoxin B₁-induced toxicity. Grape seed proanthocyanidin extract (GSPE) one of the most well-known and powerful antioxidants. Therefore, the purpose of this research was to investigate the effectiveness of GSPE in the detoxification of AFB₁ in broilers. A total of 300 one-day-old Cobb chicks were randomly allocated into five treatments of six replicates (10 birds per replicate), fed ad libitum for four weeks with the following dietary treatments: 1. Basal diet (control); 2. Basal diet + 1 mg/kg AFB₁ contaminated corn (AFB₁); 3. Basal diet + GSPE 250 mg/kg; (GSPE 250 mg/kg) 4. Basal diet + AFB₁ (1 mg/kg) + GSPE 250 mg/kg; (AFB₁ + GSPE 250 mg/kg) 5. Basal diet + AFB₁ (1mg/kg) + GSPE 500 mg/kg, (AFB₁ + GSPE 500 mg/kg). When compared with the control group, feeding broilers with AFB₁ alone significantly reduced growth performance, serum immunoglobulin contents, negatively altered serum biochemical contents, and enzyme activities, and induced histopathological lesion in the liver. In addition, AFB₁ significantly increased malondialdehyde content and decreased total superoxide dismutase, catalase, glutathione peroxide, glutathione-S transferase, glutathione reductase activities, and glutathione concentration within the liver and serum. The supplementation of GSPE (250 and 500 mg/kg) to AFB₁ contaminated diet reduced AFB₁ residue in the liver and significantly mitigated AFB₁ negative effects. From these results, it can be concluded that dietary supplementation of GSPE has protective effects against aflatoxicosis caused by AFB₁ in broiler chickens.

Sodium selenite prevents suppression of mucosal humoral response by AFB1 in broiler's cecal tonsil

Aflatoxin B₁ (AFB₁), the most common mycotoxin in human food and animal feed, produces hepatotoxic, genotoxic and immunosuppressive effects in multiple species. Selenium (Se) has emerged as an important element in the dietary prevention of various toxic agents. The present study was designed to scrutinize the protective effects of sodium selenite on the histological lesions and suppression of mucosal humoral response in the cecal tonsil generated by AFB₁. A total of 156 one-day-old broilers were divided into four groups and fed on basal diet (control group), 0.6 mg/kg AFB₁ (AFB₁ group), 0.4 mg/kg Se supplement (+Se group), and 0.6 mg/kg AFB₁ + 0.4 mg/kg Se supplement (AFB₁+Se group) respectively for 21 days. Our results showed that 0.4 mg/kg Se supplement in broiler's diets could improve the AFB₁-induced histological lesions in the cecal tonsils including the depletion of lymphocytes in the lymphatic nodules as well as the shedding of microvilli in the absorptive cells. Moreover, Se could restore the decreased number of IgA+ cells and expression levels of pIgR, IgA, IgG, and IgM mRNA induced by AFB₁ to be close to those in the control group. These results demonstrated that 0.4 mg/kg supplemented dietary Se in the form of sodium selenite could protect the cecal tonsils from the histological lesions and suppression of the mucosal humoral response provoked by 0.6 mg/kg AFB₁. Our study may provide new experimental evidences for better understanding of AFB₁-induced damage of mucosal immunity and protective effect of Se against this toxin.

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.

Protective Effects of Sporoderm-Broken Spores of Ganderma lucidum on Growth Performance, Antioxidant Capacity and Immune Function of Broiler Chickens Exposed to Low Level of Aflatoxin B₁

This study was conducted to investigate the toxic effects of aflatoxin B₁ (AFB₁) and evaluate the effects of sporoderm-broken spores of Ganoderma lucidum (SSGL) in relieving aflatoxicosis in broilers. A total of 300 one-day-old male Arbor Acre broiler chickens were randomly divided into four dietary treatments; the treatment diets were: Control (a basal diet containing normal peanut meal); AFB₁ (the basal diet containing AFB₁-contaminated peanut meal); SSGL (basal diet with 200 mg/kg of SSGL); AFB₁+SSGL (supplementation of 200 mg/kg of SSGL in AFB₁ diet). The contents of AFB₁ in AFB₁ and AFB₁+SSGL diets were 25.0 μg/kg in the starter period and 22.5 μg/kg in the finisher period. The results showed that diet contaminated with a low level of AFB₁ significantly decreased (p < 0.05) the average daily feed intake and average daily gain during the entire experiment and reduced (p < 0.05) serum contents of total protein IgA and IgG. Furthermore, a dietary low level of AFB₁ not only increased (p < 0.05) levels of hydrogen peroxide and lipid peroxidation, but also decreased (p < 0.05) total antioxidant capability, catalase, glutathione peroxidase, and hydroxyl radical scavenger activity in the liver and spleen of broilers. Moreover, the addition of SSGL to AFB₁-contaminated diet counteracted these negative effects, indicating that SSGL has a protective effect against aflatoxicosis.

Quantifying Aflatoxin B1 in peanut oil using fabricating fluorescence probes based on upconversion nanoparticles

Rare earth doped upconversion nanoparticles convert near-infrared excitation light into visible emission light. Compared to organic fluorophores and semiconducting nanoparticles, upconversion nanoparticles (UCNPs) offer high photochemical stability, sharp emission bandwidths, and large anti-Stokes shifts. Along with the significant light penetration depth and the absence of autofluorescence in biological samples under infrared excitation, these UCNPs have attracted more and more attention on toxin detection and biological labelling. Herein, the fluorescence probe based on UCNPs was developed for quantifying Aflatoxin B1 (AFB1) in peanut oil. Based on a specific immunity format, the detection limit for AFB1 under optimal conditions was obtained as low as 0.2ng·ml(-1), and in the effective detection range 0.2 to 100ng·ml(-1), good relationship between fluorescence intensity and AFB1 concentration was achieved under the linear ratios up to 0.90. Moreover, to check the feasibility of these probes on AFB1 measurements in peanut oil, recovery tests have been carried out. A good accuracy rating (93.8%) was obtained in this study. Results showed that the nanoparticles can be successfully applied for sensing AFB1 in peanut oil.

Aflatoxin B1 impairs mitochondrial functions, activates ROS generation, induces apoptosis and involves Nrf2 signal pathway in primary broiler hepatocytes

Aflatoxin B1 (AFB1) is known as a mycotoxin that causes various health problems in animals, but the precise mechanism of AFB1 on mitochondrial functions and apoptosis in primary broiler hepatocytes (PBHs) is not clear. The objective of this study was to investigate the effects of AFB1 on the mitochondrial functions, reactive oxygen species (ROS) generation, apoptosis and nuclear factor erythroid 2-like factor 2 (Nrf2)-related signal pathway in PBHs. Here, the mitochondrial membrane potential (MMP), ROS generation, antioxidative genes and apoptosis in PBHs induced by AFB1 were investigated. The results showed that AFB1 evoked mitochondrial ROS generation, decreased MMP and induced apoptosis in PBHs. AFB1 increased the percentage of apoptotic cells, and expression of caspase-9 and caspase-3, upregulated messenger RNA (mRNA) expression of Nrf2 and downregulated mRNA expressions of NAD(P)H: quinine oxidoreductase 1, superoxide dismutase and Heme oxygenase 1 in PBHs. The expression of Bax was also observed in cytoplasm. These findings suggested AFB1 results in a significant impairment of mitochondrial functions, activates ROS generation, induces apoptosis, and is involved in Nrf2 signal pathway through mitochondria ROS-dependent signal pathways in PBHs.

Hepatic Transcriptome Responses of Domesticated and Wild Turkey Embryos to Aflatoxin B₁

The mycotoxin, aflatoxin B₁ (AFB₁) is a hepatotoxic, immunotoxic, and mutagenic contaminant of food and animal feeds. In poultry, AFB₁ can be maternally transferred to embryonated eggs, affecting development, viability and performance after hatch. Domesticated turkeys (Meleagris gallopavo) are especially sensitive to aflatoxicosis, while Eastern wild turkeys (M. g. silvestris) are likely more resistant. In ovo exposure provided a controlled AFB₁ challenge and comparison of domesticated and wild turkeys. Gene expression responses to AFB₁ in the embryonic hepatic transcriptome were examined using RNA-sequencing (RNA-seq). Eggs were injected with AFB₁ (1 μg) or sham control and dissected for liver tissue after 1 day or 5 days of exposure. Libraries from domesticated turkey (n = 24) and wild turkey (n = 15) produced 89.2 Gb of sequence. Approximately 670 M reads were mapped to a turkey gene set. Differential expression analysis identified 1535 significant genes with |log₂ fold change| ≥ 1.0 in at least one pair-wise comparison. AFB₁ effects were dependent on exposure time and turkey type, occurred more rapidly in domesticated turkeys, and led to notable up-regulation in cell cycle regulators, NRF2-mediated response genes and coagulation factors. Further investigation of NRF2-response genes may identify targets to improve poultry resistance.

Vitamin E supplementation ameliorates aflatoxin B1-induced nephrotoxicity in rats

Fungal toxins in nutrition can cause organ dysfunction or even failure. Aflatoxin B1 (AFB1)-induced renal impairment is not sufficiently studied regarding its extent and prevention. The aim of this experiment was to study the effect of AFB1 on renal cortical tissue and whether its possible harmful effect could be prevented by the conventional economical antioxidant, vitamin E. Forty rats were divided into four groups; I-IV. Group I represented the control while the others received vitamin E (Vit E), AFB1 and AFB1+Vit E, respectively. Renal cortex specimens were taken from each group after 25 days. Then, specimens were prepared for histological study by hematoxlyin and eosin (H&E), Masson's trichrome, caspase-3 as well as for ultrastructural examination and oxidative stress parameters evaluation. Data were morphometrically and statistically analyzed. In AFB1-treated group, focal tubulo-interstitial affection in the form of tubular cytoplasmic vacuolation, mitochondrial disruption, numerous lysosomes, marked increase in collagen deposition and in caspase-3 expression were observed. Glomerular impairment in the form of fusion of podocytes enlarged foot processes and thickening of the glomerular basement membrane (GBM) with loss of its trilaminar appearance were detected. In the group treated by AFB1+Vit E, there were minimal affection of the histological structure of the renal cortex as well as significant increase in the anti-oxidative parameters which were significantly decreased in the AFB1-treated group. Therefore, Vit E could be considered in wide experimental studies to be a first choice antioxidant of high cost-effectiveness in prevention of fungal toxins pro-oxidant-induced renal impairment.

Macrophage Bactericidal Activities against Staphylococcus aureus Are Enhanced In Vivo by Selenium Supplementation in a Dose-Dependent Manner

Background

Dietary selenium is of fundamental importance to maintain optimal immune function and enhance immunity during infection. To this end, we examined the effect of selenium on macrophage bactericidal activities against Staphylococcus aureus.

Methods

Assays were performed in golden Syrian hamsters and peritoneal macrophages cultured with S. aureus and different concentrations of selenium.

Results

Infected and selenium-supplemented animals have significantly decreased levels of serum nitric oxide (NO) production when compared with infected but non-selenium-supplemented animals at day 7 post-infection (p < 0.05). A low dose of 5 ng/mL selenium induced a significant decrease in macrophage NO production, but significant increase in hydrogen peroxide (H₂O₂) levels (respectively, p = 0.009, p < 0.001). The NO production and H₂O₂ levels were significantly increased with increasing concentrations of selenium; the optimal macrophage activity levels were reached at 20 ng/mL. The concentration of 5 ng/mL of selenium induced a significant decrease in the bacterial arginase activity but a significant increase in the macrophage arginase activity. The dose of 20 ng/mL selenium induced a significant decrease of bacterial growth (p < 0.0001) and a significant increase in macrophage phagocytic activity, NO production/arginase balance and S. aureus killing (for all comparisons, p < 0.001).

Conclusions

Selenium acts in a dose-dependent manner on macrophage activation, phagocytosis and bacterial killing suggesting that inadequate doses may cause a loss of macrophage bactericidal activities and that selenium supplementation could enhance the in vivo control of immune response to S. aureus.

Prevention of Aflatoxin B1 Hepatoxicity by Dietary Selenium Is Associated with Inhibition of Cytochrome P450 Isozymes and Up-Regulation of 6 Selenoprotein Genes in Chick Liver

BACKGROUND

The involvement of cytochrome P450 (CYP450) isozymes and the selenogenome in selenium-mediated protection against aflatoxin B1 (AFB1)-induced adverse effects in broilers remains unclear.

OBJECTIVE

This study was designed first to determine whether selenium could reduce AFB1-induced hepatotoxic effects and then to determine whether these effects were due to changes in the CYP450 isozymes and selenogenome expression in the liver of chicks.

METHODS

Male avian broilers (aged 120 d) were allocated to 4 groups with 5 replicates of 6 birds to be included in a 2-by-2 factorial trial in which the main factors included supplementation of AFB1 (<5 compared with 100 μg/kg) and selenium (0.2 compared with 0.5 mg/kg) in a corn/soybean-based diet for 4 wk. Serum biochemistry, hepatic histology, and mRNA and/or activities of hepatic antioxidant enzymes, CYP450 isozymes, and 26 selenoproteins were analyzed at week 2 and/or 4.

RESULTS

Administration of AFB1 induced liver injury, decreasing (P < 0.05) total protein and albumin concentrations by 33.3-43.8% and increasing (P < 0.05) alanine aminotransferase and aspartate aminotransferase activities by 26.0-33.8% in serum, and induced hepatic necrosis and bile duct hyperplasia at week 2. AFB1 also decreased (P < 0.05) hepatic activities of glutathione peroxidase (GPX), thioredoxin reductase (TXNRD), and catalase, and the glutathione concentration by 13.1-59.9% and increased (P < 0.05) malondialdehyde, 8-hydroxydeoxyguanosine and exo-AFB1-8,9-epoxide (AFBO) DNA concentrations by 17.9-1200%. In addition, the mRNA and activity of enzymes responsible for the bioactivation of AFB1 into AFBO, which included CYP450 A1, 1A2, 2A6, and 3A4, were significantly induced (P < 0.05) by 29.2-271% in liver microsomes after 2-wk exposure to AFB1. These alterations induced by AFB1 were prevented by selenium supplementation. Dietary selenium supplementation increased (P < 0.05) mRNA and/or activities of 6 selenoprotein genes (Gpx3, Txnrd1, Txnrd2, Txnrd3, iodothyronine deiodinase 2, and selenoprotein N) in the liver of AFB1-treated groups at week 2.

CONCLUSIONS

Dietary selenium protected chicks from AFB1-induced liver injury, potentially through the synergistic actions of inhibition of the pivotal CYP450 isozyme-mediated activation of AFB1 to toxic AFBO, and increased antioxidant capacities by upregulation of selenoprotein genes coding for antioxidant proteins.