Effect of Sodium Selenite on Pathological Changes and Renal Functions in Broilers Fed a Diet Containing Aflatoxin B₁

Effects of supplemented multicomponent mycotoxin detoxifying agent in laying hens fed aflatoxin B1 and T2-toxin contaminated feeds

The present study was conducted to determine the ability of multicomponent mycotoxin detoxifying agent (MMDA) in feed to prevent the gastrointestinal absorption of aflatoxin B1 (AFB1) and T2-toxin supplemented via spiked maize. For comparisons, hens were fed with uncontaminated basal diet without or with addition of MMDA at 2 g/kg feed. The trial consisted of 105 laying hens (Lohmann Brown) without obvious signs of disease allocated to 7 treatment groups in 35 pens. Responses were demonstrated on laying performance and health status throughout the 42 d experimental period. The results of laying performance indicated significantly decreased egg mass with increasing mycotoxin (AFB1 and T2-toxin) levels up to the maximum tolerated dosage, however simultaneous presence of MMDA laying performance was slightly modified linearly to increasing application. Dose-dependent pathological changes in liver and kidneys and their relative weights, changes in blood parameters and reduced eggshell weights were observed in the hens fed AFB1 and T2-toxin. The pathological changes in the hens fed with diets containing AFB1 and T2-toxin without MMDA were significantly higher as compared with the control group, but eggshell stability was not affected. The contents of AFB1, T2-toxin and their metabolites in liver and kidney tissues were significantly decreased in the hens supplemented with MMDA at 2 and 3 g/kg in feed. MMDA supplementation significantly reduced the deposition of AFB1, T2-toxin and their metabolites in liver and kidneys at the maximum tolerated dosage (2 and 3 g/kg) indicating specific binding to AFB1 and T2-toxin in the digestive tract as compared to the corresponding diets without MMDA. Exposure of AFB1 and T2-toxin indicated significantly decreased egg mass with increasing mycotoxin levels up to the maximum tolerated dosage because of the significantly reduced egg production. Therefore, in this study, MMDA could reduce negative effects of feeding AFB1 and T-2 to laying hens.

PINK1/Parkin-mediated mitophagy is activated to protect against AFB1-induced kidney damage in mice

Aflatoxin B₁ (AFB₁) is a toxic food pollutant that has extensive deleterious impacts on the kidney. Oxidative stress represents the primary mechanism of AFB₁ nephrotoxicity and can also cause mitochondrial damage. Damaged mitochondria can trigger apoptosis leading to kidney injury. PINK1/Parkin-mediated mitophagy can alleviate mitochondrial injury to maintain cellular homeostasis, however, its role in AFB₁-induced kidney damage is unknown. To investigate the effect of PINK1/Parkin-mediated mitophagy on kidney impairment triggered by AFB₁, 40 male wild-type (WT) C57BL/6N mice were first assigned to 4 groups and orally exposed to AFB₁ at 0, 0.5, 0.75, and 1 mg/kg body weight (BW) for 28 days. The results revealed that AFB₁ induced kidney damage, oxidative stress, mitochondrial damage, apoptosis and activated PINK1/Parkin-mediated mitophagy with a dose-dependent effect. Then, 20 male WT C57BL/6N mice and 20 male Parkin knockout (Parkin^-/-) C57BL/6N mice were assigned to 4 groups and orally exposed to AFB₁ at 0, 1, 0, and 1 mg/kg BW for 28 days. The results revealed that Parkin^-/- suppressed mitophagy and exacerbated kidney damage, oxidative stress, mitochondrial damage, and apoptosis under AFB₁ exposure. The aforementioned evidences demonstrate that PINK1/Parkin-mediated mitophagy is activated by AFB₁ and protects against kidney damage in mice.

Effects of supplementing diet with Thyme (Thymuas vulgaris L.) essential oil and/or selenium yeast on production performance and blood variables of broiler chickens

Background

Organic products for animals are becoming more widely accepted by consumers. Using herbal additives may lead to more healthy animal products. In this research, it is hypothesized that thyme essential oil (TEO) and/or selenium yeast (SY) would be helpful to enhance production performance in broilers.

Objective

In the current study, the effects of adding TEO and/or SY to the diet on broiler performance and blood parameters were evaluated in broiler chickens.

Methods

A total of 480 chicks were distributed in 24 cages with 20 chicks (10 males and 10 females) each and assigned to be fed four iso‐caloric and iso‐nitrogenous diets including two levels (0 and 250 mg/kg) of TEO and two levels (0 and 0.3 mg/kg) of SY in a 2 × 2 factorial arrangement with six replicates.

Results

Adding SY significantly decreased feed intake in finishing period (22–42 d) (p < 0.05). Supplementation with SY and TEO significantly decreased plasma uric acid and triglyceride levels, respectively (p < 0.05). However, neither of the supplements had any influence on the plasma glucose and albumin levels (p > 0.05). The lowest level of plasma cholesterol was detected in the birds fed the TEO‐supplemented diet (p < 0.05). Addition of SY significantly increased blood glutathione peroxidase activity (p < 0.05).

Conclusions

Dietary supplemental TEO has a favourable effect on feed intake, weight gain, and body weight values. Besides, SY may decrease blood concentration of uric acid, as well as blood glutathione peroxidase activity. An interaction is detected between TEO and SY on blood cholesterol.

Curcumin ameliorates duodenal toxicity of AFB1 in chicken through inducing P-glycoprotein and downregulating cytochrome P450 enzymes

It has been reported that oral intake of aflatoxin B1 (AFB1)-contaminated feed could cause acute, sub-chronic, or chronic toxicity in livestock and poultry. However, the harmful effect of AFB1 on the small intestine is still controversial. Therefore, blocking the entry of AFB1 into the body through the digestive tract is one of the important methods to prevent its toxicity. In the present study, 1-day-old Arbor Acres broilers were randomly divided into 6 groups including control group, curcumin control group (450 mg curcumin/kg feed), curcumin low-, medium-, and high-dose group (150, 300, and 450 mg curcumin/kg feed + 5 mg AFB1/kg feed), and AFB1 group (5 mg AFB1/kg feed). After 28 d, the samples of chickens' duodenums were collected for further analyses. AFB1 caused abnormal functional and morphological changes in the duodenum, including histological lesions, increased the length of the duodenum and depth of crypt, decreased the unit weight of the duodenum, height of villus, and the value of villus height/crypt depth. Meanwhile, AFB1 administration enhanced malonaldehyde activity, 8-HOdG level, and the mRNA expression of cytochrome P450 (CYP450) enzymes, and reduced superoxide dismutase, catalase, adenosine triphosphatase (ATPase) activity and the mRNA expression of Abcb1. Importantly, curcumin supplementation partially ameliorated AFB1-induced abnormal functional and morphological signs of the duodenum, alleviated AFB1-induced oxidative stress, and decreased the mRNA expression of CYP450 enzymes. Furthermore, curcumin ameliorated AFB1-induced decrease in the Abcb1 mRNA expression, P-glycoprotein (P-gp) level, and ATPase activities. It has been suggested from these results that curcumin supplementation in the feed could ameliorate AFB1-induced duodenal toxicity and damage through downregulating CYP450 enzymes, promoting ATPase activities, and inducing P-gp in chickens.

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.

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.

Oxidative stress mediated the inhibition of cerebral creatine kinase activity in silver catfish fed with aflatoxin B1-contaminated diet

Aflatoxin B₁ (AFB₁) is an environmental toxicant and neurotoxic compound that induces the production of free radicals, causing oxidative stress. Creatine kinase (CK) is a central controller of energy metabolism in tissues with a large and fluctuating energy demand, and it is highly susceptible to inactivation by free radicals and oxidative damage. Thus, the aim of this study was to evaluate whether a diet for freshwater silver catfish (Rhamdia quelen) containing AFB₁ inhibits cerebral CK activity, as well as the involvement of the oxidative stress on this inhibition. Brain CK activity was lower on days 14 and 21 post-feeding in animals that received AFB₁-contaminated diet compared to the control group (basal diet), similarly to the brain sodium-potassium pump (Na⁺, K⁺-ATPase) activity. On the other hand, lipid peroxidation and protein carbonylation levels were higher on days 14 and 21 post-feeding in animals fed with AFB₁-contaminated feed compared to the control group, while the antioxidant capacity against peroxyl radicals and thiol content was lower. Based on these evidences, the data demonstrated that diet containing AFB₁ severely affects CK activity, an essential enzyme that plays an important role in brain energy homeostasis. Also, the impairment of energetic homeostasis linked with the use and generation of ATP via inhibition of CK activity elicited an inhibition of enzymes ATP-dependent, such as Na⁺, K⁺-ATPase. Moreover, the inhibition of brain CK activity appears to be mediated by the oxidation of lipids, proteins, and thiol group, as well as by a reduction in the antioxidant capacity.

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.

The Role of Sauropus androgynus (L.) Merr. Leaf Powder in the Broiler Chickens Fed a Diet Naturally Contaminated with Aflatoxin

Aflatoxin (AF) is the secondary metabolite of Aspergillus flavus and commonly contaminates feed during storage. AF causes lowered growth rate, stress, and increased mortality in the poultry, especially for broiler industries. The aims of this study are to determine the effects of Sauropus androgynus (L.) Merr. leaf powder (SAP) in the chickens fed a diet naturally contaminated with AF. A total of 108 chickens are divided into 6 group: group I fed with basal diet (AF not detectable); group II fed with basal diet (AF not detectable) + 5% SAP; group III with AF (>1 ppb <50 ppb); group IV with AF (>1 ppb <50 ppb) + 5% SAP; group V with AF (>51 ppb <100 ppb) + 5% SAP; group VI with AF (>101 ppb <150 ppb) + 5% SAP. The data of the body weight, feed intake and efficiency, the relative weight of liver, kidney, spleen, bursa of Fabricius (BF), histopathology, haematological profile, haemagglutination inhibition (HI) titer, AF residue, and immunohistochemistry are collected on days 7, 14, and 21. All the data were analysed using SPSS 16. The supplementation of 5% SAP in the chickens fed a diet naturally contaminated with AF showed the potential effects of the body weight performance, haematological profile protection, increase in the cellular and humoral immune responses, reduction of AF residue in the organ, protection of liver, kidney, spleen, and BF histopathology, and increase in the immune-expression of CD4+/CD8+ lymphocytes ratio (P < 0.05). It shows that 5% SAP can be used as the alternative herbal supplementation to depress the impacts of aflatoxicosis in the broiler chickens.

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.

Impact of a Single Oral Acute Dose of Aflatoxin B₁ on Liver Function/Cytokines and the Lymphoproliferative Response in C57Bl/6 Mice

Aflatoxin B₁ (AFB₁), a mycotoxin found in food and feed, exerts harmful effects on humans and animals. The liver is the earliest target of AFB₁, and its effects have been evaluated in animal models exposed to acute or chronic doses. Considering the possibility of sporadic ingestion of AFB₁-contaminated food, this study investigated the impact of a single oral dose of AFB₁ on liver function/cytokines and the lymphoproliferative response in mice. C57BL/6 mice were treated with a single oral AFB₁ dose (44, 442 or 663 μg AFB₁/kg of body weight) on the first day. Liver function (ALT, γ-GT, and total protein), cytokines (IL-4, IFN-γ, and IL-17), histopathology, and the spleen lymphoproliferative response to mitogens were evaluated on the 5th day. Although AFB₁ did not produce any significant changes in the biochemical parameters, 663 μg AFB₁/kg-induced hepatic upregulation of IL-4 and IFN-γ, along with liver tissue injury and suppression of the lymphoproliferative response to ConA (p < 0.05). In conclusion, a single oral dose of AFB₁ exposure can induce liver tissue lesions, liver cytokine modulation, and immune suppression in C57BL/6 mice.

Selenomethionine Alleviates AFB1-Induced Damage in Primary Chicken Hepatocytes by Inhibiting CYP450 1A5 Expression via Upregulated SelW Expression

This study aims to evaluate the protective effects of selenomethionine (SeMet) on aflatoxin B1 (AFB1)-induced hepatotoxicity in primary chicken hepatocytes. Cell viability and lactic dehydrogenase activity assays revealed the dose dependence of AFB1 toxicity to chicken hepatocytes. AFB1 concentrations of >0.05 μg/mL significantly reduced glutathione and total superoxide dismutase levels and increased the malondialdehyde concentration and cytochrome P450 enzyme 1A5 (CYP450 1A5) mRNA levels (P < 0.05). AFB1, however, did not affect CYP450 3A37 mRNA levels. Supplementation with 2 μM SeMet protected against AFB1-induced changes and significantly increased selenoprotein W (SelW) mRNA levels (P < 0.05). Additionally, SelW knockdown attenuated the protective effect of SeMet on AFB1-induced damage and significantly increased the level of CYP450 1A5 expression (P < 0.05). Therefore, SeMet alleviates AFB1-induced damage in primary chicken hepatocytes by improving SelW expression, thus inhibiting CYP450 1A5 expression.

The Protective Effect of Selenium on Chronic Zearalenone-Induced Reproductive System Damage in Male Mice

This study aims to explore the protective effect of selenium (Se) on chronic zearalenone (ZEN)-induced reproductive system damage in male mice and the possible protective molecular mechanism against this. The chronic ZEN-induced injury mouse model was established with the continuous intragastric administration of 40 mg/kg body mass (B.M.) ZEN for 28 days. Then, interventions with different doses (0.1, 0.2, and 0.4 mg/kg B.M.) of Se were conducted on mice to analyse the changes in organ indexes of epididymis and testis, antioxidant capability of testis, serum level of testosterone, sperm concentration and motility parameters, and the expression levels of apoptosis-associated genes and blood testis barrier- (BTB) related genes. Our results showed that Se could greatly improve the ZEN-induced decrease of epididymis indexes and testis indexes. Results also showed that the decrease in sperm concentration, sperm normality rate, and sperm motility parameters, including percentage of motile sperm (motile), tropism percentage (progressive) and sperm average path velocity (VAP), caused by ZEN were elevated upon administration of the higher dose (0.4 mg/kg) and intermediate dose (0.2 mg/kg) of Se. Selenium also significantly reduced the content of malondialdehyde (MDA) but enhanced the activities of antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx) in the testis tissue. Further research demonstrated that ZEN increased the level of mRNA expression of BCL2-associated X protein (Bax) and caspase 3 (Casp3), decreased the level of mRNA expression of B cell leukemia/lymphoma 2 (Bcl2), vimentin (Vim) and cadherin 2 (Cdh2), whereas the co-administration of Se reversed these gene expression levels. Our results indicated that high levels of Se could protect against reproductive system damage in male mice caused by ZEN and the mechanism might such be that Se improved mice antioxidant ability, inhibited reproductive cell apoptosis, and increased the decrease of BTB integrity-related genes caused by ZEN.