Μg Aflatoxin B1 Research Articles

Conversion of mycotoxin-contaminated maize by black soldier fly larvae into feed and fertilizer

Abstract Globally, large amounts of various crops such as cereals, oilseeds, nuts and spices are contaminated with mycotoxins during pre-harvest, postharvest handling, processing and/or storage. Mycotoxin contamination results into economic and health issues, and valorisation options of contaminated crops are urgently needed. The aim of this research was to evaluate whether quality feed and fertilizer can be safely produced from naturally mycotoxin contaminated crops using black soldier fly larvae (BSFL, Hermetia illucens L.) under realistic field conditions in East Africa. Naturally mycotoxin contaminated maize (corn; Zea mays L.) was used as a model due its prevalence as food and feed and utilized by BSFL together with local agri-food by-products at a research facility in Rwanda. To assess the influence of the initial maize mycotoxin contamination and maize inclusion, larval diets with three mycotoxin contamination levels and two maize inclusion levels were tested. BSFL were tolerant against the high mycotoxin concentrations (e.g. 99.4 μg aflatoxin B1 kg dry mass-1) as the presence of mycotoxins in the substrate did not affect BSFL mass at harvest. Product safety was assessed by quantifying the presence of 38 common and emerging mycotoxins and metabolites in the maize, substrates and BSFL products (e.g. larvae and frass). The results show that it is possible to produce feed and fertilizer with BSFL considered safe within the European Union and East African legal limits with maize contaminated with mycotoxins typical for East Africa. Thereby, this research works towards the safe recycling of nutrients from mycotoxin contaminated maize within the food system in East Africa and beyond.

Research Note: Effects of feeding corn naturally contaminated with aflatoxin B1, deoxynivalenol, and zearalenone on reproductive performance of broiler breeders and growth performance of their progeny chicks

To evaluate the toxic effects of mycotoxin-contaminated corn (MC) on the breeders and their progeny chicks, a total of 480 fifty-wk-old Cobb broiler breeder hens were fed the following dies: 1) a corn-soybean meal diet (Control; containing 70.35% corn), 2) MC substituting for 50% of corn in Control (LM), 3) LM diet plus 2 g/kg 1 mycotoxin sequestrant, Toxy-Nil Plus (TNP) (LMT2.0), 4) MC substituting for 100% of corn in Control (HM), 5) HM diet plus 2 g/kg TN (HMT2.0), and 6) HM diet plus 2.5 g/kg TNP (HMT2.5). The MC contained 69.25 μg aflatoxin B1 (AFB1)/kg, 4,875 μg deoxynivalenol (DON)/kg, and 2,262 μg zearalenone (ZEN)/kg. At wk 4 after MC inclusion, all eggs laid were used for hatch, and all progeny chicks were fed the same mycotoxin-untreated diet for 14 d. Dietary MC inclusion decreased the hatchability of set eggs and increased embryo mortality during d 18 to 21.5. The TNP addition increased these aforementioned indices in MC-included diets. Maternal HM treatment decreased the BW of progeny chicks at age of 14 d and BWG of progeny chicks during d 1 to 14, whereas maternal LM treatment did not affect these indices. In parallel, maternal HM treatment decreased the concentrations of serum IgA, IgG, and lysozyme in the progeny chicks on d 14, but maternal LM treatment did not affect these indices. Overall, maternal dietary TNP treatments increased the growth of progeny chicks and had a trend to increase the concentrations of serum IgA and IgG on d 14 compared to maternal MC treatments. It was concluded that the feeding of relative high ratio of corn contaminated with low level of AFB1, DON, and ZEN negatively affected the reproductive performance of breeders and the growth performance of their progeny chicks, and TNP addition alleviated these toxic effects.

Effects of dietary aflatoxin on biochemical parameters and histopathology of liver in Matrinxã (Brycon cephalus) and Pacu (Piaractus mesopotamicus) fish

The objective of this study was to evaluate biochemical parameters and histopathology of liver in Matrinxã (Brycon cephalus) and Pacu (Piaractus mesopotamicus) fish chronically exposed to dietary aflatoxins. Fish feed was artificially contaminated with aflatoxins and the treatments were: Control – feed without toxin; Treatment A – feed + 10 μg aflatoxin B1 (AFB1)/kg; Treatment B – feed + 20 μg AFB1/kg; and Treatment C – feed + 50 μg AFB1/kg. Matrinxã and Pacu juvenile fish were placed in tanks for 180 days. Five experimental units per treatment were monthly sampled and submitted to blood collection and removal of hepatic tissue. Thus, twenty blood and liver samples for each species were collected monthly, adding up to 240 samples analysed. To verify biochemical changes, analyses included total proteins, albumin, globulins, aspartate aminotransferase (AST) and alkaline phosphatase (ALP). The hepatic tissue was examined microscopically and the slides presenting histopathological changes were photo-documented. There was effect of treatment (P<0.05) for AST and ALP in Matrinxã, while no effect (P>0.05) was observed in Pacu. A reduction (P<0.05) in AST and ALP values during the time of exposure was observed in all treatments for both species. Fatty degeneration and liver damage were observed for both species in treatments exposed to aflatoxins. Fatty degeneration in Pacu was noticed after 30 days of exposure, while in Matrinxã it was observed after 60 days. Disorganisation of the hepatocyte cord arrangement was also observed in those treatments exposed to aflatoxin, following 90 days of exposure in Matrinxã, and after 60 days in Pacu. Therefore, aflatoxins have little influence on biochemical parameters in the species evaluated. However, exposure to aflatoxins caused liver changes, such as cell death, fatty and hydropic degeneration, thus it could be concluded that both species are susceptible to the toxic effects of long-term exposure to dietary AFB1.

Dietary Curcumin Alleviated Acute Ileum Damage of Ducks (Anas platyrhynchos) Induced by AFB1 through Regulating Nrf2-ARE and NF-κB Signaling Pathways.

Aflatoxin B1 (AFB1) is a stable toxic metabolite threatening health of human and animal and widely contaminated animal feed and human food. This present study aimed to investigate the effects of dietary curcumin on ileum injury in ducks induced by AFB1 administration and explore its underlying mechanisms. Ducks (N = 450, one-day-old male) with a similar weight were randomly assigned to 3 groups, containing the control group, AFB1 group (60 μg AFB1 kg−1 body weight) and curcumin (500 mg curcumin kg−1 diet) + AFB1 group. AFB1 administration markedly increased the ileum damage, AFB1-DNA adducts in the plasma and oxidation stress and inflammation. Adding curcumin into diet protected the ileum against morphology damage induced by AFB1 administration, decreased AFB1-DNA adducts in the plasma and eliminated oxidation stress and inflammation in the ileum of ducks. Anti-oxidation and anti-inflammatory effects of curcumin could protect the ileum against acute damage via activating Nrf2-ARE signaling pathway and inhibiting NF-κB signaling pathway. Conclusively, curcumin was a dietary anti-oxidation and anti-inflammation agent via activating Nrf2-ARE signaling pathway and inhibiting NF-κB signaling pathway to protect ileum against acute damage induced by AFB1 administration.

Oncogenic and tumor suppressor pathways in subchronic aflatoxicosis in rats: Association with serum and urinary aflatoxin exposure biomarkers

In this study, the changes in oncogenic and tumor suppressor signaling pathways in liver and their association with serum and urinary biomarkers of aflatoxin exposure were evaluated in Wistar rats fed diets containing aflatoxin B1 (AFB1) for 90 days. Rats were divided into four groups (n = 15 per group) and assigned to dietary treatments containing 0 (control), 50 (AFB50), 100 (AFB100) and 200 μg AFB1 kg−1 diet (AFB200). Multiple preneoplastic foci of hepatocytes marked with glutathione-S-transferase-placental form (GST-P) were identified in AFB100 and AFB200 groups. Hepatocellular damage induced by AFB1 resulted in overexpression of cyclin D1 and β-catenin. The liver expression of retinoblastoma (Rb) and p27Kip1 decreased in AFB100 and AFB200 groups, confirming the favorable conditions for neoplastic progression to hepatocellular carcinoma. All samples from rats fed AFB1-contaminated diets had quantifiable AFB1-lysine in serum or urinary AFM1 and AFB1-N7-guanine, with mean levels of 20.42–50.34 ng mL−1, 5.31–37.68 and 39.15–126.37 ng mg−1 creatinine, respectively. Positive correlations were found between AFB1-lysine, AFM1 or AFB1-N7-guanine and GST-P+, β-catenin+ and cyclin D1+ hepatocytes, while Rb + cells negatively correlated with those AFB1 exposure biomarkers. The pathways evaluated are critical molecular mechanisms of AFB1-induced hepatocarcinogenesis in rats.

Long-term exposure of Pacu (Piaractus mesopotamicus) fish to dietary aflatoxin B1: residues in tissues and performance

The objective of this work was to evaluate the aflatoxins residues on tissues of Pacu (Piaractus mesopotamicus) fish chronically exposed to dietary aflatoxins, also evaluating the effects on fish performance. Aflatoxins were incorporated into the extruded fish feed and the concentrations were confirmed by high performance liquid chromatography (HPLC). The experimental design comprised the following treatments: Control – feed without toxin; Treatment A: feed + 10 μg aflatoxin B1 (AFB1)/kg; Treatment B: feed + 20 μg AFB1/kg and Treatment C: feed + 50 μg AFB1/kg. Pacu juvenile were allocated in tanks with density of one fish per litter. The experiment lasted 180 days with monthly sampling, and approximately ten fish per treatment were used to compose a sample. Biometric surveys were performed every 30 days, including standard weight and length. Aflatoxins were detected and quantified in fish muscle and liver by HPLC, using immunoafinity columns. Results showed AFB1 deposition in the liver throughout the experiment in all treatments, but only treatment C differed significantly (P<0.05) from the others after 150 days, while in muscle there was low residual deposition. Long-term exposed fish had negative influence in weight and length. The higher mortality was observed in treatment C. Although there were AFB1 residues at low levels in liver and only a slight amount in fish muscle, it should be noted that accumulation is possible in the Pacu species. The diets contaminated with AFB1 negatively interfered in weight and length of fish when compared to control. Therefore, it can be concluded that long-term exposure of Pacu to dietary AFB1 can cause losses to producers.

Innate Immune Response and Growth Performance of Heterobranchus longifilis Catfish Juveniles Following Dietary Aflatoxin B1 Exposure

We evaluated the effects of dietary aflatoxin B1 (AFB ) exposure on the immune response and the 1 growth performance of Heterobranchus longifilis catfish; and determined the maximum tolerable limits for AFB in H. longifilis. Five experimental isocaloric and isonitrogenous diets amended 1 with varied concentrations of AFB [Diet A (2.0 μg AFB .kg-1); Diet B (7.3 μg AFB .kg-1); Diet C 1 1 1 (17.6 μg AFB .kg-1); Diet D (48.0 μg AFB .kg-1) and Diet E (93.0 μg AFB .kg-1)] were fed to 450 1 1 1 juvenile H. longifilis in five groups of 15 separate plastic tanks for a period or 56 days. At time points day 7, 14, 28 and day 56, five fish were randomly sampled per tank and assessed for innate immunity and growth response. Fish fed diets amended with AFB exhibited significant reduction 1 (P < 0.05) in the serum lysozyme and epidermal mucus lysozyme activity, epidermal mucus alkaline phosphatase activity and in the phagocyte respiratory burst activity. These parameters decreased with increasing concentrations and duration of dietary AFB (P< 0.05). Dietary AFB 1 1 caused significant reductions in the growth performance of juvenile H. longifilis marked by reductions in the percentage gain in length, reduction in percentage gain in weight and a reduction in the specific growth rate. Based on these results, juvenile H. longifilis catfish appears to tolerate diets containing up to 17.6 μg. Kg-1 AFB in diets.

Environmental consequences of the treatment of corn contaminated by aflatoxin B1 with co-digestion and co-composting in a life cycle perspective.

Global environmental performances of anaerobic co-digestion and co-composting of aflatoxin B1 (AFB1) contaminated corn were investigated by a life cycle assessment approach. Anaerobic co-digestion of pig slurry and corn with 25 μgkg-1 ww AFB1 concentration resulted able to generate 627 NLkgVS-1 of biogas with a reduction of the AFB1 concentration in the digestate of 44%. At AFB1 concentration of 100 μg kg-1 ww, the process resulted strongly inhibited with a biogas generation of 122 NLkgVS-1 and AFB1 concentration reduction in the digestate of 25%. Co-composting of 100 μg kg-1 dw AFB1 contaminated corn with other substrates as organic fraction of municipal waste, pig slurry, and other lignin-cellulosic residues showed a removal efficiency of AFB1 ranging from about 80 up to 95% depending on the different mixtures adopted. Environmental consequences associated to the removal of 1 mg of AFB1 in different scenarios investigated, including also the use on land of the digestate and of the compost, indicated that global warming was affected equally by co-digestion and co-composting, about 95 kgCO2eq. Co-digestion showed also the possibility of achieving avoided emissions of about - 0.007 kgNMVOCeq, - 2.5E-3 kgPeq, and - 30CTUe. Benefits concerning resource depletion resulted higher for co-composting due to the high amount of mineral fertilizer replaced. Contribution of AFB1 in the determination of human health (DALY) resulted lower than about 4% for co-digestion and practically negligible for co-composting.

Combined effects of aflatoxin B1 and deoxynivalenol on the expression of glutathione redox system regulatory genes in common carp.

The purpose of the present study was to evaluate the short-term effects of aflatoxin B1 (AFB1 ) and deoxynivalenol (DON) exposure on the expression of the genes encoding the glutathione redox system glutathione peroxidase 4a (gpx4a), glutathione peroxidase 4b (gpx4b), glutathione synthetase (gss) and glutathione reductase (gsr) and the oxidative stress response-related transcription factors Kelch-like ECH-associated protein 1 (keap1) and nuclear factor-erythroid 2 p45-related factor 2 (nrf2) in liver, kidney and spleen of common carp. During the 24-hr long experiment, three different doses (5µg AFB1 and 110µg DON; 7.5µg AFB1 and 165µg DON or 10µg AFB1 and 220µg DON/kg bw) were used. The results indicated that the co-exposure of AFB1 and DON initiated free radical formation in liver, kidney and spleen, which was suggested by the increase in Nrf2 dependent genes, namely gpx4a, gpx4b, gss and gsr. Expression of keap1 gene showed upregulation after 8hr of mycotoxin exposure, and also upregulation of nrf2 gene was found in kidney after 8hr of exposure, while in the liver, only slight differences were observed. The changes in the expression of the analysed genes suggest that level of reactive oxygen species reached a critical level where other signalling pathway was activated as described by the hierarchical model of oxidative stress.

Lack of Dose- and Time-Dependent Effects of Aflatoxin B1 on Gene Expression and Enzymes Associated with Lipid Peroxidation and the Glutathione Redox System in Chicken.

Effects of aflatoxin B1 (AFB1) on lipid peroxidation and glutathione system were investigated in chicken liver. In a three-week feeding trial, different doses (<1.0 μg/kg (control diet), 17.0 µg (diet A1), 92.0 µg (diet A2), and 182.0 µg (diet A3) AFB1 kg/feed) were used. Markers of lipid peroxidation, conjugated dienes and trienes showed higher values in A3, while amounts of thiobarbituric acid reactive substances were increased in the A1 group at day 21. Glutathione content was lower at day 14 in Group A2. Glutathione peroxidase 4 activity was increased at days 7 and 21 in the A3 group but reduced in the A2 and A3 groups at day 14. The GPX4 gene was downregulated at day 7 in the A2 group, but overregulated at days 14 and 21, and at day 14 in the A3 group. GSS was downregulated at day 14 in the A1 group but overregulated at day 21 in A1 and A2 groups. GSR was downregulated at days 7 and 21 in all treatment groups, but on day 14, induction was observed in the A3 group. The results indicated that AFB1 did not induce dose- or time-dependent effects on the glutathione redox system and its encoding genes at the dose range used, which means that oxidative stress is not the primary effect of AFB1 toxicity.

DI/LC-MS/MS-Based Metabolome Analysis of Plasma Reveals the Effects of Sequestering Agents on the Metabolic Status of Dairy Cows Challenged with Aflatoxin B1.

The study applied a targeted metabolomics approach that uses a direct injection and tandem mass spectrometry (DI–MS/MS) coupled with a liquid chromatography–tandem mass spectrometry (LC–MS/MS)-based metabolomics of plasma to evaluate the effects of supplementing clay with or without Saccharomyces cerevisiae fermentation product (SCFP) on the metabolic status of dairy cows challenged with aflatoxin B1. Eight healthy, lactating, multiparous Holstein cows in early lactation (64 ± 11 DIM) were randomly assigned to one of four treatments in a balanced 4 × 4 duplicated Latin square design with four 33 d periods. Treatments were control, toxin (T; 1725 µg aflatoxin B1 (AFB1)/head/day), T with clay (CL; 200 g/head/day), and CL with SCFP (YEA; 35 g of SCFP/head/day). Cows in T, CL, and YEA were dosed with aflatoxin B1 (AFB1) from days 26 to 30. The sequestering agents were top-dressed from day 1 to 33. On day 30 of each period, 15 mL of blood was taken from the coccygeal vessels and plasma samples were obtained from blood by centrifugation and analyzed for metabolites using a kit that combines DI–MS/MS with LC–MS/MS-based metabolomics. 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. Biomarker profiles for aflatoxin ingestion in dairy cows fed no sequestering agents were determined using receiver–operator characteristic (ROC) curves, as calculated by the ROCCET web server. A total of 127 metabolites such as amino acids, biogenic amines, acylcarnitines, glycerophospholipids, and organic acids were quantified. Compared with the control, T decreased (p < 0.05) plasma concentrations of alanine, leucine, and arginine and tended to decrease that of citrulline. Treatment with CL had no effects on any of the metabolites relative to the control but increased (p ≤ 0.05) concentrations of alanine, leucine, arginine, and that of citrulline (p = 0.07) relative to T. Treatment with YEA resulted in greater (p ≤ 0.05) concentrations of aspartic acid and lysine relative to the control and the highest (p ≤ 0.05) plasma concentrations of alanine, valine, proline, threonine, leucine, isoleucine, glutamic acid, phenylalanine, and arginine compared with other treatments. The results of ROC analysis between C and T groups revealed that the combination of arginine, alanine, methylhistidine, and citrulline had sufficient specificity and sensitivity (area under the curve = 0.986) to be excellent potential biomarkers of aflatoxin ingestion in dairy cows fed no sequestering agents. This study confirmed the protective effects of sequestering agents in dairy cows challenged with aflatoxin B1.

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.

Lactobacillus rhamnosus GG modulates gastrointestinal absorption, excretion patterns, and toxicity in Holstein calves fed a single dose of aflatoxin B1

The aim of the present study was to evaluate the effects of Lactobacillus rhamnosus GG (LGG; ATCC 53013) on growth performance and hepatotoxicity in calves fed a single dose of aflatoxin B1 (AFB1) and to investigate the absorption, distribution, and elimination of AFB1 and the hydroxylated metabolite aflatoxin M1 (AFM1) in rumen fluid, blood, and excretions. Twenty-four male Holstein calves were blocked for body weight and age and were randomly assigned to 1 of 3 treatment groups: (1) untreated control, (2) treated with 4.80 mg of AFB1 (AFB1 only), or (3) treated with 1 × 1010 cfu of LGG suspension and 4.80 mg of AFB1 (AFB1 plus LGG). The calves received LGG suspension in 50 mL of phosphate-buffered saline daily via oral administration for 14 d before and on the day they received a single oral dose of AFB1. Body weight was recorded at the beginning of the study (before LGG administration), at the day of AFB1 administration, and at the end of the trial. Rumen fluid, blood, urine, and feces samples were collected continuously for 96 h after AFB1 administration. Average daily gain (ADG) and plasma biochemical parameters were analyzed, and concentrations of AFB1 and AFM1 in the samples were determined for monitoring excretion pattern and toxicokinetics. The results showed that ADG was lower in AFB1-treated animals; LGG administration partially mitigated the decrease in ADG (0.85 ± 0.08 vs. 0.76 ± 0.18 kg of gain/d). The AFB1 treatment increased plasma aspartate aminotransferase, alkaline phosphatase, and lactate dehydrogenase levels. Administration of LGG alleviated the AFB1-induced increase in plasma enzymes activity. The excretion patterns of AFB1 and AFM1 were surprisingly regular; toxins were rapidly detected in all samples after a single oral dose of AFB1, and the peak of toxins concentrations was sequentially reached in rumen fluid, plasma, urine, and feces (except AFM1 in rumen fluid), followed by an exponential decrease. The excretion curves showed that AFB1 and AFM1 concentrations were the highest in feces and urine, respectively. Administration of LGG decreased the concentrations of free AFB1 and AFM1 in rumen fluid and reduced the release of toxins into plasma and urine. Toxicokinetic parameters (except for the time of maximum concentration and the terminal half-life) were reduced by LGG administration. In conclusion, the absorption, distribution, and excretion of AFB1 and AFM1 were rapid in calves fed a single dose of AFB1. Urine was the main route for the excretion of AFM1, and the clearance pattern from the peak of concentration was well fitted by exponential decreasing function. Administration of LGG reduced the absorption of AFB1 in the gastrointestinal tract by increasing the excretion via the feces, thus alleviating the hepatotoxic effect of AFB1.

AMELIORATIVE ROLE OF VITAMIN A ON LIVER TOXICITY INDUCED BY AFLATOXIN B1 ON ALBINO RATS: HISTOLOGICAL AND ULTRASTRUCTURAL STUDY

Aflatoxins are highly toxic, mutagenic, teratogenic and carcinogenic compounds produced by some species of Aspergillus, especially Aspergillus flavus and Aspergillus parasiticus. The aim of this study was to investigate the possible ameliorative role of vitamin A (Vit. A) on aflatoxin (AF) induced hepatotoxicity through histopathological and ultrastructural approaches on liver tissue of female albino rats treated with aflatoxin B1 (AFB1). Animals were divided into 5 groups of 6 rats each. Group I, animals of this group had been kept as normal without any treatment and were considered as controls. Group 2, animals of this group were orally administered vehicle 50% DMSO (dimethylsulfoxide) alone. Group 3, animals of this group were orally administered vehicle with Vit. A (132 IU double the human therapeutic dose). Group 4, animals of this group were orally administered 0.05μg AFB1 per kg dissolved in 50% DMSO. Group 5, animals of this group were orally administered 0.05μg AFB1 per kg with Vit. A. The experiment lasted for 14 weeks, animals were dissected 24 hours post treatment. The histological investigations of the treated group clearly demonstrated, active Kupffer cells, inflammation, fatty changes with many apoptotic changes. Other investigated fields, illustrated necrotic area in the portal zone, dilated and congestion blood vessels, and hydropic vacuolization of degenerated hepatocytes. At the ultrastructural level, irregular nuclear envelop, deformed endoplasmic reticulum and mitochondria were demonsterated. On the other side, the administration of Vit. A to AFB1-treated animals revealed more or less normal hepatocytes, inflammation of the portal area and well-defined central vein with scattered inflammed cells, with lobulated nuclei. So, special care must be taken when using stored grain as food, then natural sources should be used as vitamin A as an antioxidant.

Effects of dietary mixed aflatoxin B1 and fumonisin B1 on growth performance and haematology of juvenile Clarias gariepinus catfish

This study aimed to determine the effects of dietary mixtures of aflatoxin B1 (AFB1) and fumonisin B1 (FB1) on growth performance and haematology of juvenile Clarias gariepinus and also determine the maximum tolerable limits for the mixture of these mycotoxins in C. gariepinus. Five experimental diets amended with varied concentrations of AFB1 and FB1 (Diet A (control 2.0 μg AFB1; 3.0 mg FB1/kg); Diet B (7.3 μg AFB1; 15.0 mg FB1/kg); Diet C (17.6 μg AFB1; 24.5 mg FB1/kg); Diet D (48.0 μg AFB1; 43.0 mg FB1/kg) and Diet E (93.0 μg AFB1; 83.0 mg FB1/kg were fed to 450 juvenile C. gariepinus catfish in five groups of 15 separate plastic tanks for a period or 56 days. Five fish were randomly sampled from each tank at time points day 7, 14, 28 and day 56. These fish were weighed, length measured and bleed for haematological determinations. Fish fed the diets amended with mixtures of AFB1 and FB1 exhibited significant reduction (p < 0.05) in growth performance marked by reduction in mean length gain; mean weight gain and specific growth rate compared to fish fed the control diets. Further, fish fed diets amended with mixtures of the mycotoxins showed significant reduction (p < .05) in the erythrocytes count, haemoglobin concentration and haematocrit compared to fish fed the control diet. Based on the results of growth and haematological performance, juvenile C. gariepinus can tolerate diets containing up to 17.6 μg AFB1/kg and 24.5 mg FB1/kg.

Aflatoxin B1 (AFB1) reduces growth performance, physiological response, and disease resistance in Tra catfish (Pangasius hypophthalmus)

Triplicate groups of one hundred Tra catfish (8 g ± 0.2) were fed seven test diets containing increasing levels of AFB1 (0, 50, 100, 250, 500, and 1000 μg AFB1 kg−1). Additionally Mycofix® Secure was added at 1.5% to one diet containing 500 μg AFB1 kg−1. Results showed that Tra catfish are sensitive to AFB1. Reduction in weight gain (P 0.05) hepatosomatic index (HIS), while an increase in adipose somatic index (ASI) was observed in fish fed 50 μg AFB1 kg−1 and above when compared to the control and Mycofix® diets. After 12 weeks, blood serum analysis revealed higher alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels in fish fed the 50, 100, and 250 μg AFB1 kg−1 suggesting occurrence of liver damage. Disease resistance of fish exposed to Edwardsiella ictaluri was also compromised by the presence of AFB1 in the feed and was directly related to the contamination level. Seven days after Edwardsiella ictaluri exposure, survival rates were 50, 41.7, 31.7, and 8.3% for fish fed control, 50, 100, and 250 μg AFB1 kg−1, respectively. This trial shows that AFB1 at a level of 50 μg AFB1 kg−1 and above can affect fish performance and disease resistance. Application of an effective mycotoxin management in the feed seems to be useful to prevent the negative effects of AFB1.

Effects of copper oxide nanoparticles on antioxidant enzyme activities in liver tissue of Clarias gariepinus

This study aimed to determine the effects of dietary mixtures of aflatoxin B1 (AFB1) and fumonisin B1 (FB1) on growth performance and haematology of juvenile Clarias gariepinus and also determine the maximum tolerable limits for the mixture of these mycotoxins in C. gariepinus. Five experimental diets amended with varied concentrations of AFB1 and FB1 (Diet A (control 2.0 μg AFB1; 3.0 mg FB1/kg); Diet B (7.3 μg AFB1; 15.0 mg FB1/kg); Diet C (17.6 μg AFB1; 24.5 mg FB1/kg); Diet D (48.0 μg AFB1; 43.0 mg FB1/kg) and Diet E (93.0 μg AFB1; 83.0 mg FB1/kg were fed to 450 juvenile C. gariepinus catfish in five groups of 15 separate plastic tanks for a period or 56 days. Five fish were randomly sampled from each tank at time points day 7, 14, 28 and day 56. These fish were weighed, length measured and bleed for haematological determinations. Fish fed the diets amended with mixtures of AFB1 and FB1 exhibited significant reduction (p < 0.05) in growth performance marked by reduction in mean length gain; mean weight gain and specific growth rate compared to fish fed the control diets. Further, fish fed diets amended with mixtures of the mycotoxins showed significant reduction (p < .05) in the erythrocytes count, haemoglobin concentration and haematocrit compared to fish fed the control diet. Based on the results of growth and haematological performance, juvenile C. gariepinus can tolerate diets containing up to 17.6 μg AFB1/kg and 24.5 mg FB1/kg.

AFLATOXIN B1 INDUCED RENAL TOXICITY IN RATS AND THE AMELIORATIVE ROLE OF VITAMIN A

This study was designed to investigate the possible protective therapeutic dose of vitamin A on kidneys of female rats treated with aflatoxin B1 (AFB1). Animals were divided into 5 equal groups, each group containing 6 rats. Group I: animals served as normal controls. Group 2: animals of this group were orally administered vehicel with vitamin A (132 IU) double the human therapeutic dose. Group 3: animals were orally administered vehicle 50% DMSO alone. Group 4: animals were orally administered 0.05 μg AFB1 per kg dissolved in 50% DMSO (dimethylsulfoxide). Group 5: animals were orally administered 0.05 μg AFB1/kg with vitamin A. The experiment lasted for 14 weeks, and then animals were sacrificed and dissected after 24 hours. Kidney sections of female rats treated with either DMSO orand AFLB1 individually showed pathological changes represented by vacuolations of epithelial cells of the renal tubules; inflammatory cell infiltration; lobulated glomreuli; hemorrhage; degenerated renal tubules; dilated congested blood vessels and degenerated areas with rupturing in Bowman's capsule and widen Bowman's space, accompanied with pyknotic nuclei of the renal tubule cells. On the histochemical level, data obtained showed significant reduction of protein, DNA and polysaccharides contents in kidney tissues. Vitamin A administration showed a partial improvement of the above mentioned histopathological and histochemical alterations.

Effects of different sources of Saccharomyces cerevisiae biomass on milk production, composition, and aflatoxin M1 excretion in milk from dairy cows fed aflatoxin B1

The aim of the present study was to evaluate the effect of different sources of Saccharomyces cerevisiae (SC) biomass (20.0 g/d) obtained from sugarcane (cell wall, CW; dried yeast, DY; autolyzed yeast, AY) and the beer industry (partially dehydrated brewery yeast, BY) on milk production, fat and protein percentages, and aflatoxin M1 (AFM1) excretion in milk from dairy cows receiving 480 µg aflatoxin B1 (AFB1) per day. A completely randomized design was used with 2 lactating cows assigned to each of 10 dietary treatments, as follows: negative controls (no AFB1 or SC-based biomass), positive controls (AFB1 alone), DY alone, DY + AFB1, BY alone, BY + AFB1, CW alone, CW + AFB1, AY alone, and AY + AFB1. The cows in the aflatoxin treatment group received AFB1 from d 1 to 6, while the SC biomass was administered with the AFB1 bolus from d 4 to 6. Aflatoxin B1 or SC-based products did not affect milk production or milk composition during the experimental period. Aflatoxin M1 was detected in the milk from all aflatoxin treatment group cows, reaching maximum levels at d 3 and varying from 0.52 ± 0.03 to 1.00 ± 0.04 µg/L. At end of the treatment period, CW, AY, DY, and BY removed 78%, 89%, 45%, and 50% of AFM1 from the milk, respectively, based on the highest level found on d 3. Results indicate a potential application of industrial fermentation by-products, especially CW and AY, as a feed additive in the diets of dairy cows to reduce the excretion of AFM1 in milk.

Determination of Aflatoxin B1-Lysine in Pig Serum and Plasma by Liquid Chromatography-Tandem Mass Spectrometry.

Aflatoxin B1 (AFB1) is a hepatocarcinogen produced by certain Aspergillus species growing on crops. After biotransformation in the liver, AFB1 generates several metabolites, one of which is AFB1 bound to lysine on serum albumin. AFB1-lysine (AFB1-lys) is a digest product of AFB1-albumin and is considered a biomarker of exposure to AFB1 in humans and animals. The objectives of this paper were to evaluate the performance characteristics of a new analytical method for determination of AFB1-lys levels in pig serum, heparinized and ethylenediaminetetraacetic acid (EDTA) plasma and to evaluate the interference of these anticoagulants in AFB1-lys quantification. Blank blood samples were obtained from eight crossbreed 91-day-old barrows fed AFB1-free diets. Pooled samples (n = 3) and individual samples of serum, EDTA and heparinized plasma collected from five pigs were enzymatically digested with pronase at 37°C for 4 h. AFB1-lys was isolated by solid-phase extraction and quantified by liquid chromatography coupled to tandem mass spectrometry. The analytical method was applied for determination of AFB1-lys in serum and EDTA plasma collected from five 49-day-old crossbreed barrows fed ad libitum diets containing 1.1 mg of AFB1 per kg of feed during 7 days (three animals) or 42 days (two animals). Samples of heparinized plasma were only available from animals intoxicated for 42 days. All animals had lower levels of AFB1-lys in EDTA plasma samples (24.78-37.40 ng/mL), when compared to serum (49.32-252.07 ng/mL-1) or heparinized plasma (176.81 and 264.24 ng/mL-1). EDTA did not interfere in AFB1-lys standard detection, but our findings suggest that EDTA should be avoided during blood collection since it affects the pronase activity in AFB1-albumin adduct digestion and, consequently, causes a reduction in the AFB1-lys levels. Hence, determination of AFB1-lys in serum and heparinized plasma is an approach to assess an individual's exposure of swine to AFB1.