Dietary Aflatoxin B1 Research Articles

Spirulina platensis mediated the biochemical indices and antioxidative function of Nile tilapia (Oreochromis niloticus) intoxicated with aflatoxin B1

Aflatoxicosis is one of the threats that cause severe mortalities in fish farms. The dietary functional additives are a friendly approach attributed to beneficial effects on aquatic animals. The study aimed at evaluating the impact of Spirulina platensis (SP) on the biochemical indices and antioxidative function of Nile tilapia (Oreochromis niloticus) intoxicated with aflatoxin B1 (AFB1). A control diet and 3 test diets were enriched with 0% SP/0 mg AFB1/kg (control), 1% SP (SP), 2.5 mg AFB1/kg diet (AFB1), and 1% SP+2.5 mg AFB1/kg diet (SP/AFB1). The diets were supplied to three aquaria for each group twice daily at the rate of 2.5% for 30 days. The blood alanine transaminase (ALT), alkaline phosphatase (ALP), and aspartate transaminase (AST) were significantly increased by AFB1 toxicity with regards to fish fed the control and SP diets (P < 0.05). The inclusion of SP in the diet of tilapia intoxicated with AFB1 lowered the levels of ALT, AST, and ALP in comparison to fish contaminated with AFB1 without SP (P < 0.05). The total blood protein and albumin were decreased in fish contaminated with AFB1 (P < 0.05); however, the dietary SP resulted in improving the blood protein and albumin with similar levels with the control and SP diets. The urea and creatinine were increased in tilapia fed AFB1 diet without SP (P < 0.05); however, the inclusion of SP reduced the levels of urea and creatinine with similar levels with the control and SP diets. The antioxidative capacity of Nile tilapia fed SP and contaminated with AFB1 is expressed by superoxide dismutase (SOD), glutathione (GSH), and malondialdehyde (MDA) concentration. The activities of SOD and GSH were decreased by AFB1 (P < 0.05); however, dietary SP increased the SOD and GSH in fish fed AFB1. On the other hand, the concentration of MDA was increased in tilapia fed AFB1 (P < 0.05); however, SP decreased the level of MDA in fish fed AFB1. In conclusion, the application of SP in the aquafeed seems to be an innovative approach to relieve the toxic influences of AFB1 on aquatic animals.

Aflatoxicosis in fingerling common carp (Cyprinus carpio) and protective effect of rosemary and thyme powder: Growth performance and digestive status

Dietary aflatoxin B1 contamination is a demanding challenge for aquaculture industry. The present study was conducted to elucidate the effect of dietary aflatoxin B1 contamination on growth and digestive status of juvenile common carp. The effect of dietary inclusion of rosemary and thyme to prevent such effects was also investigated. Fingerlings were subjected to seven treatments including various dietary aflatoxin B1 contamination (0, 50, 100, 200, 300 and 400 ppb) and a group received diet contained 400 ppb aflatoxin B1 and 4% rosemary and thyme powder. The experiment lasted for 12 weeks. Results revealed that dietary aflatoxin B1 contamination did not affect growth performance. However, intestinal alkaline protease, lipase and amylase activity of fish were increased according to aflatoxin B1 diet levels. In addition, intestine tissue lesions including necrosis, immune cell infiltration and fibroplasia were manifested with increasing dietary aflatoxin B1 content. Digestive enzymes activity was ameliorated by dietary incorporation of the plant powder in those fish received diet with 400 ppb aflatoxin B1, but it did not prevent intestinal lesions. In conclusion, juvenile common carp showed no changes regarding various growth indices even at 400 ppb aflatoxin B1 level. Although, 50 ppb dietary aflatoxin B1 did not significantly affect growth or digestive enzymes activity of juveniles, it caused mild intestinal tissue deteriorative changes. Including the medicinal powder blend in diet with 400 ppb aflatoxin B1 could ameliorate the increased digestive enzymes activity; however, it did not prevent the intestinal tissue pathological changes. Understanding the exact mechanisms behind such protective effect requires further studies.

Corn Flour Intake, Aflatoxin B1 Exposure, and Risk of Esophageal Precancerous Lesions in a High-Risk Area of Huai'an, China: A Case-Control Study.

Aflatoxin B1 (AFB1), which has potent toxicity and carcinogenicity, is a common contaminant of important agricultural commodities. This study aimed to investigate the frequency of corn flour intake and assess the exposure to AFB1 via direct detection of AFB1 in the diet and serum AFB1 exposure biomarker, so as to evaluate their associations with the risk of esophageal precancerous lesions (EPL). A case-control study based on three-day duplicate diet samples was performed in Huai’an District. One hundred EPL cases and 100 healthy controls were enrolled and required to be age- (±2 years) and gender-matched. The concentration of AFB1 in food samples and the level of serum AFB1-albumin (AFB1-Alb) adduct were quantitatively analyzed. Results showed that corn flour intake was positively associated with serum AFB1-Alb adduct level (p for trend = 0.003), dietary AFB1 exposure (p for trend < 0.001), and the risk of EPL (p for trend = 0.017). Increased serum AFB1-Alb adduct level was associated with an increased risk of EPL as well (p for trend < 0.001). In conclusion, corn flour may be an essential source of AFB1 in Huai’an District, whereas high exposure to AFB1 is likely to be an important risk factor contributing to the progression of EPL.

Evaluation of growth performance, hematological, biochemical and histopathological parameters of Rhamdia quelen fed with a feed artificially contaminated with aflatoxin B1

Contamination by aflatoxin B1 (AFB1) in fish is related to several non-specific signs, including immunosuppression, inadequate growth, histological and behavioral changes. Hematological, biochemical and histopathological parameters can be important diagnostic tools to evaluate metabolic and cellular processes in fish. The objective of this study was to determine the effects of diets containing different levels of AFB1 fed to silver catfish (Rhamdia quelen). A total of 624 silver catfish juveniles (mean weight of 7.44 g ± 2.18) were distributed into 4 different treatments (T1, T2, T3 and T4 containing 0, 45, 90 and 180 μg.kg−1 AFB1, respectively). Fish were randomly divided into 24 aquaria (n = 26 per aquarium) and fed for 56 consecutive days with pelleted feed. Growth, hematological, serum biochemistry and histopathological parameters were evaluated on days 28, 42 and 56 of the experimental period. There were no significant differences (p > 0.05) in the growth parameters when comparing the treatments exposed to AFB1 with the control treatment. AFB1 was able to induce hematological and biochemical changes consistent with metabolic disorders in the silver catfish and these were found in liver, gill and renal tissue. Different concentrations of dietary AFB1 had no effect on growth performance of silver catfish in a linear way, nor do they cause histological alterations in the evaluated organs. Nonetheless, fish fed AFB1 containing diets showed hematological and biochemical changes consistent with immunosuppression and hepatoxicity, which are commonly reported in animals exposed to AFB1.

PSXII-2 DI/LC-MS/MS-based plasma metabolomics reveals the effects of sequestering agents on the metabolic status of dairy cows challenged with dietary aflatoxin B1

Abstract The study applied a targeted quantitative metabolomics approach using a combination of direct injection and tandem mass spectrometry (DI-MS/MS) with a liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based plasma metabolomics to evaluate the effects of supplementing clay and/or a Saccharomyces cerevisiae fermentation product (SCFP) on the metabolic status of dairy cows challenged with aflatoxin B1. Eight lactating cows were randomly assigned to 1 of 4 treatments in a balanced 4 × 4 Latin square design with 2 squares. Treatments were control, toxin (T; 1725 µg AFB1/head/day), T with clay (CL; 200 g/head/day), and CL with SCFP (CL+SCFP; 35 g of SCFP/head/day). Cows in T, CL, and CL+SCFP were dosed with aflatoxin B1 (AFB1) from d 26 to 30. The sequestering agents were top-dressed from d 1 to 33. On d 30 of each period, 15 mL of blood was taken from the coccygeal vessels and plasma samples were prepared by centrifugation. Plasma samples were analyzed using a kit that combines DI-MS/MS with LC-MS/MS. The data were analyzed using the GLIMMIX procedure of SAS. The model included the effects of treatment, period, and random effects of cow and square. Significance was declared at P ≤ 0.05. A total of 128 metabolites, including amino acids, biogenic amines, acylcarnitines, glycerophospholipids, and organic acids were quantified. Compared to the control, T decreased (P ≤ 0.05) plasma concentrations of 16 metabolites (6 amino acids, 6 acylcarnitines, and 4 glycerophospholipids). In contrast, T increased plasma concentrations of sarcosine, uric acid, and aspartic acid. Treatment with CL increased concentrations of arginine, lysine, and 5 organic acids. Treatment with CL+SCFP increased the concentrations of 7 amino acids and 4 acylcarnitines, but reduced the concentrations of sarcosine and 3 organic acids. Results of this study indicate that supplementing clay and/or SCFP altered plasma metabolomic profile in dairy cows challenged with AFB1.

Effect of sequestering agents based on a Saccharomyces cerevisiae fermentation product and clay on the ruminal bacterial community of lactating dairy cows challenged with dietary aflatoxin B1

This study was conducted to examine the effects of clay (CL) and Saccharomyces cerevisiae fermentation product (SCFP) on the ruminal bacterial community of Holstein dairy cows challenged with aflatoxin B1 (AFB1). A second objective was to examine correlations between bacterial abundance and performance measures. Eight lactating dairy cows stratified by milk yield and parity were randomly assigned to 4 treatments in a 4 × 4 Latin square design with 2 replicate squares, four 33-d periods, and a 5-d washout between periods. The treatments included (1) control (basal diet, no additive); (2) T (control + 63.4 µg/kg AFB1, oral dose); (3) CL (T + 200 g/head per day of sodium bentonite clay, top-dress); and (4) CL+SCFP [CL + 19 g/head per day Diamond V NutriTek (Diamond V Inc., Cedar Rapids, IA) + 16 g/head per day MetaShield (Diamond V Inc.), top-dress]. Cows were adapted to diets containing no AFB1 from d 1 to 25 (predosing period). From d 26 to 30 (dosing period), AFB1 was orally dosed and then withdrawn for d 31 to 33 (withdrawal period). During the predosing period, compared with the control, feeding CL and CL+SCFP increased the relative abundance of the most dominant phylum, Bacteroidetes (55.1 and 55.8 vs. 50.6%, respectively), and feeding CL+SCFP increased Prevotella abundance (43.3 and 43.6 vs. 40.0%, respectively). During the dosing period, feeding AFB1 did not affect the ruminal bacterial community, but the relative abundance of Fibrobacteraceae increased with CL+SCFP compared with T (1.45 vs. 0.97%); Fibrobacter abundance also tended to increase with CL+SCFP compared with T and control, respectively (1.45 vs. 0.97 and 1.05%, respectively). Feeding AFB1 with or without CL or CL+SCFP did not affect ruminal pH or concentrations of NH3-N, total volatile fatty acids, or individual volatile fatty acids. Milk yield and milk component yields were positively correlated with the relative abundance of unclassified Succinivibrionaceae, unclassified YS2, or Coprococcus. Feed efficiency was positively correlated (r ≥ 0.30) with the relative abundance of unclassified YS2, Coprococcus, or Treponema. Feeding aflatoxin at 63 µg/kg, a common contamination level on farms, did not affect the abundance of dominant bacteria or rumen fermentation. When aflatoxin was fed, CL+SCFP increased the abundance of Fibrobacter, a major fibrolytic bacteria genus. Milk yield and DMI were positively correlated with abundance of Succinivibrionaceae and Coprococcus. Feed efficiency was positively correlated with abundance of Coprococcus, Treponema, and YS2. Future studies should speciate culture and determine the functions of the bacteria to elucidate their roles in the rumen and potential contribution to increasing the performance of dairy cows.

Effects of zeolite inclusion in aflatoxin B1-contaminated diet on the performance of laying duck

The researchwas objected to study the effect of zeolite inclusion in aflatoxin B1 (AFB1) contaminated diet on the performance of laying duck. A completely randomized design was adopted in the in vivo experiment that consisted of 4 treatments, namely: (1) commercial feed (Control); (2) AFB1-contaminated feed 70 ppb (AFC); (3) Control + 2% zeolite; and (4) AFC + 2% zeolite. Each treatment had 4 replications with 4 ducks in each replication. A total of 64 eight months-female Alabio duck (Anas platyrinchos Borneo) were used in 28 days of the feeding experiment. Data were analyzed according to the general linear model of SPSS 21.0 statistical software. Results indicated that AFB1 exposure significantly (P&lt;0.05) decreased the body weight of laying duck by 1.12%. Zeolite inclusion could prevent the adverse effect of AFB1 on body weight that increased by 2.95% in AFC+2% zeolite. Treatments had no significant effect on egg production and egg weight (P&gt;0.05). Zeolite inclusion resulted in the highest final body weight whilst AFB1 diet without zeolite resulted in the lowest final body weight (P&lt;0.05). Relative liver weight of duck fedAFC diet was 16.62% and to be 15.4% by zeolite addition in the diet. In conclusion, 2% of zeolite inclusion could reduce the adverse effects of AFB1 exposure on the performance of laying duck.

The effect of moderate-dose aflatoxin B1 and Salmonella Enteritidis infection on intestinal permeability in broiler chickens.

The effect of dietary aflatoxin B1 (AFB1) and Salmonella Enteritidis infection on intestinal permeability was investigated. Two hundred 1-day-old male Ross 308 broiler chickens were randomly divided into 4 treatments of 5 replicates each (10 birds per replicate), which were fed ad libitum for 3weeks with the following treatments: control, chickens fed an AFB1-free diet; AF, chickens fed an AFB1-contaminated diet at 470ng/g; SE, chickens fed an AFB1-free diet and challenged with 108cfu of S. Enteritidis per bird at 18days old; AF + SE, chickens fed an AFB1-contaminated diet and challenged with 108cfu of S. Enteritidis per bird at 18days old. At day 21 of age, chicks received an oral gavage dose of fluorescein isothiocyanate dextran (FITC-dextran) to evaluate gastrointestinal leakage. Blood and intestinal samples were collected to evaluate serum biochemistry and total intestinal IgA secretion, respectively. Liver tissues were aseptically collected to assess bacterial invasiveness and for histomorphological studies. The results showed that chickens receiving AFB1 presented a significant increment (up to 2.4-fold) in serum FITC-dextran concentration (p < 0.05). Nevertheless, S. Enteritidis infection had no additional effect on gastrointestinal leakage. Furthermore, the ingestion of AFB1 had no impact on the invasive potential of S. Enteritidis. These results suggest that moderate-dose AFB1 adversely affects intestinal barrier function resulting in increased gut permeability in broiler chickens.

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

Selenium (Se) plays a protective role in aflatoxin B1 (AFB1)-induced splenic immunotoxicity in chicks. This study was designed to reveal the underlying mechanism of Se-mediated protection against AFB1-induced splenic injury in broilers. 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. 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. Dietary Se deficiency exacerbated AFB1-induced spleen injury in chicks, partially through the regulation of oxidative stress, inflammatory and apoptotic signaling, and 6 selenoproteins.

Efficacy of Bacillus subtilis ANSB060 Biodegradation Product for the Reduction of the Milk Aflatoxin M₁ Content of Dairy Cows Exposed to Aflatoxin B₁.

This study was conducted to determine the effect of Bacillus subtilis ANSB060 biodegradation product (BDP) in reducing the milk aflatoxin M1 (AFM1) content of dairy cows fed a diet contaminated with aflatoxin B1 (AFB1). Twenty-four Chinese Holstein cows (254 ± 19 d in milk; milk production 19.0 ± 1.2 kg d−1) were assigned to three dietary treatments, as follows: (1) control diet (CON), consisting of a basal total mixed ration (TMR); (2) aflatoxin diet (AF), containing CON plus 63 μg of AFB1 kg−1 of diet dry matter; and (3) aflatoxin diet plus BDP (AF + BDP), containing AF plus BDP at 0.2% of diet dry matter. The experiment lasted 12 days, including an AFB1-dosing period from days one to eight, followed by a clearance period from days nine to twelve. Milk samples were collected on days 2, 4, 6, and 8–12, and the plasma was sampled on day 9, before morning feeding. Short-term AFB1 exposure did not affect the milk production and composition. The plasma biochemical indices, except for lactic dehydrogenase (LDH), were also not changed by the AFB1 intake. The plasma LDH level was significantly elevated (p < 0.05) following dietary treatment with AFB1, while no significant difference was observed between the AF + BDP and CON treatments. Adding BDP to the AFB1-contaminaed diet resulted in a significant reduction in AFM1 concentration (483 vs. 665 ng L−1) in the milk, AFM1 excretion (9.14 vs. 12.71 μg d−1), and transfer rate of dietary AFB1 to milk AFM1 (0.76 vs. 1.06%). In conclusion, the addition of BDP could be an alternative method for reducing the dietary AFB1 bioavailability in dairy cows.

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.

Assessment of the efficacy of a grape seed waste in counteracting the changes induced by aflatoxin B1 contaminated diet on performance, plasma, liver and intestinal tissues of pigs after weaning

The aim of this study was to investigate the potential of a grape seed byproduct to mitigate the harmful damage produced by aflatoxin B1 (AFB1) at systemic level in plasma and liver as well as at local level in the gastrointestinal tract in weaned piglets. Twenty four crossbred pigs (TOPIG) were randomly assigned to one of four experimental diets: 1)- control diet (normal compound feed for starter piglets without mycotoxin), 2)- AFB1 diet (compound feed contaminated with 320 ppb pure AFB1), 3)- GS diet (compound feed including 8% of grape seed meal), 4)- AFB1+GS diet (compound feed containing 8% of grape seed meal contaminated with 320 ppb AFB1) for 30 days. The results showed that pigs fed AFB1 diet had altered performance (−25.1%), increased the thiobarbituric substances (TBARS) concentration wile reduced total antioxidant capacity and activity of antioxidant enzymes (CAT, SOD and GPx) in plasma and organs. AFB1 produced a dual effect on inflammatory response by increasing the level of pro-inflammatory cytokines in liver and colon and decreasing these cytokines in duodenum. The inclusion of grape seed in the diet of AFB1 intoxicated pigs enhanced the antioxidant enzymes activity, decreased the pro-inflammatory cytokines and TBARS level and ameliorated the growth performance of AFB1-treated animals. These findings suggest that grape waste is a promising feed source in counteracting the harmful effect of aflatoxin B1.

Differential Transcriptome Responses to Aflatoxin B₁ in the Cecal Tonsil of Susceptible and Resistant Turkeys.

The nearly-ubiquitous food and feed-borne mycotoxin aflatoxin B1 (AFB1) is carcinogenic and mutagenic, posing a food safety threat to humans and animals. One of the most susceptible animal species known and thus a good model for characterizing toxicological pathways, is the domesticated turkey (DT), a condition likely due, at least in part, to deficient hepatic AFB1-detoxifying alpha-class glutathione S-transferases (GSTAs). Conversely, wild turkeys (Eastern wild, EW) are relatively resistant to the hepatotoxic, hepatocarcinogenic and immunosuppressive effects of AFB1 owing to functional gene expression and presence of functional hepatic GSTAs. This study was designed to compare the responses in gene expression in the gastrointestinal tract between DT (susceptible phenotype) and EW (resistant phenotype) following dietary AFB1 challenge (320 ppb for 14 days); specifically in cecal tonsil which functions in both nutrient absorption and gut immunity. RNAseq and gene expression analysis revealed significant differential gene expression in AFB1-treated animals compared to control-fed domestic and wild birds and in within-treatment comparisons between bird types. Significantly upregulated expression of the primary hepatic AFB1-activating P450 (CYP1A5) as well as transcriptional changes in tight junction proteins were observed in AFB1-treated birds. Numerous pro-inflammatory cytokines, TGF-β and EGF were significantly down regulated by AFB1 treatment in DT birds and pathway analysis suggested suppression of enteroendocrine cells. Conversely, AFB1 treatment modified significantly fewer unique genes in EW birds; among these were genes involved in lipid synthesis and metabolism and immune response. This is the first investigation of the effects of AFB1 on the turkey gastro-intestinal tract. Results suggest that in addition to the hepatic transcriptome, animal resistance to this mycotoxin occurs in organ systems outside the liver, specifically as a refractory gastrointestinal tract.

Effects of aflatoxin B1 on reproductive performance of farmed Nile tilapia

ABSTRACTThis study evaluated the effect of dietary aflatoxin B1 (AFB1) on growth, milt and egg quality in matured Nile tilapia (Oreochromis niloticus). Triplicate groups of Nile tilapia (initial body weight 24.1 ± 2.6 g) were fed with either of four diets (Diets 1 to 4) designed to contain 0, 20, 200 and 2000 μg AFB1 kg−1 diets for 24 weeks. After 24 weeks of AFB1 exposure, growth was significantly (P <0.05) different between the control and the AFB1 exposed treatments in both sexes. No significant differences were observed in 17β-oestradiol, absolute fecundity, oocytes volume and diameters between AFB1 exposure groups and the control group. However, we observed a significant reduction in relative fecundity and gonad somatic index (GSI) in females fed 2000 μg AFB1 kg−1 diet. On the other hand, we observed significant differences (P <0.05) in gonadosomatic index (GSI), testosterone, milt count and motility between males in the control group and AFB1 treatments. We conclude that rearing Nile tilapia with aflatoxin-contaminated diets for a prolonged period affects milt quality, fecundity (at higher doses) and growth performance. This implies that for optimal seed production, provision of aflatoxin free diets should be part of the management practices in Nile tilapia hatcheries.

Effects of Dietary Aflatoxin B1 on Physiological Biomarkers with Special Reference to Udder Health of Lactating Goats

Effects of Dietary Aflatoxin B1 on Physiological Biomarkers with Special Reference to Udder Health of Lactating Goats

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.

Dietary aflatoxin B1 decreases growth performance and damages the structural integrity of immune organs in juvenile grass carp (Ctenopharyngodon idella)

For many years, feed-borne mycotoxin contamination has been a serious and unavoidable problem in the aquaculture industry. This problem is extensively aggravated due to the increasing replacement of fish meal by plant protein. Aflatoxin B1 (AFB1) is a mycotoxin that has received a great deal of attention, owing to its prevalence in plant feedstuffs and detrimental effects on animals. The objective of this study was to investigate the effect of AFB1 on growth and health. The growth performance and structural integrity of immune organs were evaluated after feeding grass carp diets with 0, 29, 59, 86, 110 and 147 μg AFB1/kg for 60 days. The results indicated that dietary AFB1 caused poor growth performance and deformities in juvenile grass carp. In addition, we are the first to observe that AFB1 was detectable in the head kidney and spleen of juvenile grass carp and damages the structural integrity of those organs. And we, for the first time, explore potential mechanisms of this destruction effect to immune organs of fish, which might be partly involved in (1) attenuating antioxidant ability through up-regulation of Keap1a (not Keap1b) to suppress Nrf2 signalling leading to decrease of mRNA levels and activities of antioxidant enzymes (except GSTP1 mRNA level); (2) aggravating apoptosis partly by activating p38 MAPK signalling to activate mitochondria pathway and death receptor pathway; and (3) weakening TJs structure by promoting MLCK signalling to down-regulate the mRNA of TJs protein (claudin-12 was up-regulated) in the head kidney and spleen. Finally, based on the oxidative injury-related indexes (contents of MDA in the head kidney and PC in the spleen), the safe upper doses of AFB1 for grass carp were first estimated to be 30 and 29 μg/kg diet, respectively.

Hepatocellular carcinomas are promoted by tocopheryl acetate but eliminated by tocopheryl succinate

BackgroundThe major causes of hepatocellular carcinomas are Aflatoxin, hepatitis B and hepatitis C viruses.Alpha tocopherol and its acetate and succinate esters have each been reported as counteracting cancer development in humans and rodents. We have investigated their salutary effect in both poor and high quality diets in rainbow trout Oncorhynchus mykiss as a model. MethodsHepatocellular carcinomas (HCCs) were induced in rainbow trout by dietary aflatoxin B1 (AfB1). A matrix of different levels of several vitamins and vitamin analogues were included in selected diets as possible anticancer agents. Identification of HCCs was made by histopathology. Results1.) Elevated dietary tocopheryl acetate (E-Ac) caused a marked increase in liver size and in AfB1-induced HCCs in rainbow trout. 2.) Poor diets increased the HCC incidence. 3.) Elevated dietary tocopheryl succinate (E-Su) nearly eliminated HCC development in fish fed complete diets. Tocopheryl succinate in poor diets reduced HCCs by 77% compared to tocopheryl acetate diets. 4.) Trans-retinoic acid also reduced HCC incidence. 5.) Vitamins A and D deficiency caused tumor increases but had no effect on liver size. 6.) The use of casein and dextrin in the place of soybean textured vegetable protein, in poor diets nearly eliminated the HCC risk. 7.) Trout sera showed all three vitamin forms; free α-tocopherol (E-OH), tocopheryl acetate (E-Ac) and tocopheryl succinate (E-Su), from diets containing any of these vitamin analogues, suggesting both de-esterification and trans-esterification. 8.) E-Su is discussed in the light of an anti-cancer agent that is non toxic to normal tissue but that cohorts to it are needed. ConclusionsIncreased dietary E-Ac escalated AfB1 induced HCCs and caused hepatomegaly in rainbow trout, while E-Su eliminated the HCC risk as shown by histopathology.

Effects of dietary aflatoxin B1 on accumulation and performance in matrinxã fish (Brycon cephalus).

Aflatoxins (AF) can be cumulative in fish tissues and can influence weight, length, feed intake and survival depending on the species. The aim of this work is to measure performance and aflatoxin levels in tissues of matrinxã (Brycon cephalus) fish chronically exposed to aflatoxin. Aflatoxin was incorporated into fish diets at the following levels: Control Feed + 0 μg AFB1 kg-1; A. Feed + 10 μg AFB1 kg-1; B. Feed + 20 μg AFB1 kg-1; C. Feed + 50 μg AFB1 kg-1. It was used one tank per treatment, each one with 150 juvenile fish, and three replicates within each tank were used for sampling, that was carried out monthly over a period of six months. Aflatoxin was quantified by HPLC in fish liver and muscle after clean up using immunoaffinity columns. Performance was evaluated by using weight, length, consumption and survival rate. Muscle and liver aflatoxin levels were below the limit of detection in all control samples. Aflatoxins B2, G1 and G2 were not detected in any tissues. Traces (values between limits of detection and quantification) of AFB1 were observed in liver tissue in treatment A from day 30 through 90, reaching 0.32 μg AFB1 kg-1 at 150 days of exposure. Treatment B presented traces up to day 60 and had, with a maximum level of 0.39 μg AFB1 kg-1 at 150 days of exposure. Treatment C had aflatoxin residues after day 30, with values ranging from 0.17 to 0.61 μg AFB1 kg-1 during exposure. Muscle samples only had traces of AFB1 in all treatments. Fish was affected by exposure to AFB1 with higher values (P<0.05) for weight and length in treatments A, B and C relative to controls. Therefore, results indicate that matrinxã do not accumulate AFB1 residues in edible tissues, but chronic exposure affects the species.

Oxidative Stress in Extrahepatic Tissues of Rats Co-Exposed to Aflatoxin B1 and Low Protein Diet

Early life exposure to aflatoxin B1 (AFB1) and low protein diet through complementary foods during weaning is common in parts of Africa and Asia. This study evaluated the effect of co-exposure to AFB1 and low protein diet on the extrahepatic tissues of rats. Twenty-four three-week old weanling male albino rats were used for this study and were randomly assigned into four groups: group 1 served as control and was fed normal protein diet (20% protein), group 2 was fed low protein diet (5% protein), group 3 was fed normal protein diet + 40 ppb AFB1 while group 4 received low protein diet + 40 ppb AFB1, all for eight weeks. Afterward, biomarkers of anemia (packed cell volume (PCV), hemoglobin) and kidney function (urea, uric acid, and creatinine) were determined in the blood while biomarkers of oxidative stress were determined in the tissues spectrophotometrically. Co-exposure to AFB1 and low protein diet significantly (p< 0.05) decreased body weight gain and PCV, increased biomarkers of kidney functions and induced oxidative stress in the tissues studied. There was significant (p< 0.05) reduction in glutathione concentration while TBARS was significantly increased in the tissues. Co-exposure to AFB1 and low protein diet had additive effects on decreasing the weight gain and potentiation effect of kidney dysfunction in the rats. The co-exposure also decreased antioxidant enzymes and increased oxidant status in the tissues. Our results demonstrate that this co-exposure has deleterious health effects on extrahepatic tissues and should be a public health concern especially in developing countries where AFB1 contamination is common.