Effects of Sodium Selenite on Aflatoxin B1-Induced Decrease of Ileal IgA+ Cell Numbers and Immunoglobulin Contents in Broilers

This study was aimed to assess the protective effect of sodium selenite on the ileum mucosal immunologic injury induced by AFB₁. One hundred eighty-one-day-old healthy male Avian broilers were divided into four groups of three replicates and 15 birds per replicate and fed with basal diet (control group), 0.3 mg/kg AFB₁ (AFB₁ group), 0.4 mg/kg Se (+Se group), and 0.3 mg/kg AFB₁?+?0.4 mg/kg Se (AFB₁?+?Se group) respectively. The numbers of IgA⁺ cells of ileum were determined by immunohistochemistry as well as the contents of sIgA, IgA, IgG, and IgM in the mucosa of ileum by ELISA. Compared with those in the control group, the numbers of IgA⁺ cells as well as the sIgA, IgA, IgG, and IgM contents were decreased in the AFB₁ group. However, compared with those in the AFB₁ group, the numbers of IgA⁺ cells as well as the sIgA, IgA, IgG, and IgM contents were increased in the AFB₁?+?Se group, and these data had no difference between AFB₁?+?Se group and control group. It was concluded that 0.3 mg/kg AFB₁ could reduce the humoral immune function of the ileum mucosa, but 0.4 mg/kg supplemented dietary selenium could protect the mucosal humoral immune function from AFB₁-induced impairment.     

Effects of Sodium Selenite on Aflatoxin B1-Induced Decrease of Ileac T cell and the mRNA Contents of IL-2, IL-6, and TNF-α in Broilers

The aim of this work was to assess the protective effect of sodium selenite on the ileum mucosal immunologic toxicity induced by aflatoxin B₁ (AFB₁). One hundred and eighty one-day-old healthy male avian broilers were divided into four groups of three replicates and 15 birds per replicate and fed with basal diet (control group), 0.3 mg/kg AFB₁ (AFB₁ group), 0.4 mg/kg Se (+Se group), and 0.3 mg/kg AFB₁?+?0.4 mg/kg Se (AFB₁+Se group), respectively. The ileac T-cell subsets were determined by the methods of flow cytometry (FCM), and the mRNA contents of interleukin-2 (IL-2), interleukin-6(IL-6), and tumor necrosis factor-alpha (TNF-α) by quantitative real-time PCR. Compared with those in control group, the percentages of CD₃ ⁺, CD₃ ⁺CD₄ ⁺, CD₃ ⁺CD₈ ⁺ intraepithelial lymphocytes (IELs) and LPLs, the CD4⁺/CD8⁺ ratio of IELs, and the mRNA contents of IL-2, IL-6, and TNF-α were decreased in AFB₁ group. However, compared with those in AFB₁ group, these parameters of AFB₁+Se group were increased to be close to those in control group. It was concluded that 0.3 mg/kg AFB₁ could reduce the cellular immune function of the ileum mucosa, but 0.4 mg/kg supplemented dietary selenium showed protective effects on AFB₁-induced immunologic injury.     

Effects of Aflatoxin B1 Exposure and Sodium Selenite Supplementation on the Histology,Cell Proliferation,and Cell Cycle of Jejunum in Broilers

The aim of this study was to investigate the effects of aflatoxin B₁ (AFB₁) exposure and sodium selenite supplementation on the histology, cell proliferation and cell cycle of jejunum in broilers. A total of 240 1-day-old male AA broilers were divided into four groups of 60 each, fed with basal diet (control group), 0.3 mg/kg AFB₁ (AFB₁ group), 0.4 mg/kg supplement Se (Se group), and 0.3 mg/kg AFB₁?+?0.4 mg/kg supplement Se (AFB₁ + Se group) for 21 days, respectively. Compared with the control group, decreased jejunal villus height, villus height/crypt ratio, and proliferation cell nuclear antigen (PCNA)-positive cells, and G₂/M phase arrest and shedded epithelial cells on the tip of jejunal villus were observed in AFB₁ groups at 7 and 14 days of age. However, the villus/crypt ratio, PCNA-positive cells and cell percentage of G₀/G₁, S, and G₂/M phases had no significant differences between AFB₁ group and control group at 21 days. Simultaneous supplementation with sodium selenite restored these parameters to be close to those in control group. In conclusion, 0.3 mg/kg AFB₁ in the diet inhibits the development of broiler’s jejunum by reducing cellular proliferation and inducing G₂/M arrest during only the first 2 weeks after hatching. Supplementation of dietary sodium selenite at the concentration of 0.4 mg/kg Se had protective action against these toxic effects of AFB₁.     

Panax ginseng extract modulates oxidative stress,DNA fragmentation and up-regulate gene expression in rats sub chronically treated with aflatoxin B1 and fumonisin B1

Aflatoxins and fumonisins are important food-borne mycotoxins implicated in human health and have cytotoxic effects. The aims of the current study were to evaluate the protective role of Panax ginseng extract (PGE) against the synergistic effect of subchronic administration of aflatoxin B₁ (AFB₁) and fumonisin B₁ (FB₁) on DNA and gene expression in rat. Female Sprague–Dawley rats were divided into eight groups (ten rats/group) and treated for 12 weeks including the control group, the group having received AFB₁ (80 µg/kg bw), the group having received FB₁ (100 µg/kg bw), the group having received AFB₁ plus FB₁ and the groups having received PGE (20 mg/kg bw) alone or with AFB₁ and/or FB₁. At the end of experiment, liver and kidney were collected for the determination of DNA fragmentation, lipid peroxidation (LP), glutathione (GSH) contents and alterations in gene expression. The results indicated that these mycotoxins increased DNA fragmentation, LP and decreased GSH content in liver and kidney and down-regulated gene expression of antioxidants enzymes. The combined treatments with AFB₁ and/or FB₁ plus PGE suppressed DNA fragmentation only in the liver, normalized LP and increased GSH in the liver and kidney as well as up-regulated the expression of GPx, SOD1 and CAT mRNA. It could be concluded that AFB₁ and FB₁ have synergistic genotoxic effects. PGE induced protective effects against their oxidative stress and genotoxicity through its antioxidant properties.     

The Molecular Mechanisms of Protective Role of Se on the G<Subscript>2</Subscript>/M Phase Arrest of Jejunum Caused by AFB<Subscript>1</Subscript>

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

Protective effect of esculin against prooxidant aflatoxin B1-induced nephrotoxicity in mice

The study was designed to investigate the protective effect of esculin against pro-oxidant aflatoxin B₁ (AFB₁)-induced nephrotoxicity in mice. In this study toxicity was developed by oral administration of AFB₁ at a dose of 66.60 μg/kg bw/day for 90 days in male Swiss albino mice. Esculin (150 mg/kg bw/0.2 ml/day) and standard compound ascorbic acid (300 mg/kg bw/0.2 ml/day) was given after 30 min of AFB₁ administration for 90 days. Protective efficacy was assessed by measuring the levels of lipid peroxidation (LPO) and non-enzymatic antioxidants such as reduced glutathione (GSH) and also by measuring activities of enzymatic antioxidants such as glutathione peroxidase (GPX), glutathione-S-transferase (GST), glutathione reductase (GR), superoxide dismutase (SOD) and catalase (CAT) in kidney. Results were analysed at the 30^th, 60^th and 90^th day of the daily treatments, which showed a decrease in the level of LPO and an increase in the levels of enzymatic and non-enzymatic antioxidants. The protective effect of esculin was further proved by histopathological findings as it exhibited regenerative activities in mice renal tubules against AFB₁-induced nephrotoxicity. The results obtained clearly demonstrate that the protective efficacy of esculin against pro-oxidant AFB₁-induced nephrotoxicity in mice might be due to its antioxidants and free radical scavenging properties.     

Determination of serum aflatoxin B<Subscript>1</Subscript>-lysine to evaluate the efficacy of an aflatoxin-adsorbing feed additive in pigs fed an aflatoxin B<Subscript>1</Subscript>-contaminated diet

In this study, serum aflatoxin B₁ (AFB₁)-lysine was determined in order to evaluate the in vivo efficacy of a hydrated sodium calcium aluminosilicate (HSCAS) in pigs fed AFB₁. Twenty-four 49-day-old crossbred barrows were maintained in individual cages and allowed ad libitum access to feed and water. A completely randomized design was used with six animals assigned to each of four dietary treatments for 21 days as follows: (A) basal diet (BD), (B) BD supplemented with 0.5 % HSCAS, (C) BD supplemented with 1.1 mg/kg AFB₁, and (D) BD supplemented with 0.5 % HSCAS and 1.1 mg/kg AFB₁. HSCAS was able to alleviate the toxic effects of AFB₁ on pigs and reduce (P < 0.05) the levels of serum AFB₁-lysine. Cumulative reductions of adduct yield values, calculated through the equation [(pg AFB₁-lysine/mg albumin) / (μg AFB₁/kg body weight)], were 53.0, 62.8, and 72.1 after 7, 14, and 21 days of oral exposure, respectively. AFB₁-lysine has potential as an AFB₁-specific biomarker for diagnostic purposes and for evaluating the efficacy of chemoprotective interventions in pigs.     

Investigation of in vitro and in vivo antioxidant potential of secoisolariciresinol diglucoside

The present study was designed to evaluate the in vitro and in vivo ameliorative antioxidant potential of secoisolariciresinol diglucoside (SDG). In vitro antioxidant activity of synthetic SDG was carried out using DPPH, reducing power potency, and DNA protection assays. Wistar albino rats weighing 180–220 g were used for in vivo studies and liver damage was induced in the experimental animals by a single intraperitoneal (I.P.) injection of CCl₄ (2 g/kg b.w.). Intoxicated animals were treated orally with synthetic SDG at (12.5 and 25 mg/kg b.w.) and Silymarin (25 mg/kg) for 14 consecutive days. The levels of catalase (CAT), superoxide dismutase (SOD), peroxidase (POX), and lipid peroxidase (LPO) were measured in liver and kidney homogenates. The synthetic SDG exerts high in vitro antioxidant potency as it could scavenge DPPH at a IC₅₀ value of 78.9 μg/ml and has dose-dependent reducing power potency and protected DNA at 0.5 mg/ml concentration. Oral administration of synthetic SDG at 12.5 and 25 mg/kg b.w. showed significant protection compared to Silymarin (25 mg/kg) and the activities of CAT, SOD, and POX were markedly increased (P < 0.05), whereas LPO significantly decreased (P < 0.001) in a dose-dependent manner in liver and kidney in both pre- and post-treatment groups when compared to toxin-treated group. The results of in vitro and in vivo investigations revealed that synthetic SDG at 25 mg/kg b.w. is associated with beneficial changes in hepatic enzyme activities and thereby plays a key role in the prevention of oxidative damage in immunologic system.     

Exposure to aflatoxin B<Subscript>1</Subscript> in Thailand by consumption of brown and color rice

This study assessed the aflatoxin B₁ (AFB₁) intake of the Thai population through consumption of contaminated brown and color rice. A total of 240 rice samples from two harvesting periods were collected in June/July 2012 (period I) and in December 2012/January 2013 (period II) and analyzed for AFB₁ by HPLC with fluorescence detection (limit of detection (LOD)?=?0.093 ng/g). Exposure assessment was based on AFB₁ levels in rice and food intake data for rice according to Thai National Consumption. Frequency and levels of AFB₁ were higher in period I (59 %, <LOD?=?26.61 μg kg^?1) than in period II (10 %, <LOD?=?3.51 μg kg^?1). Only one sample exceeded the Thai standard limit for total aflatoxin of 20 μg kg^?1, but 12 out of 240 rice samples exceeded the European Union maximum level for AFB₁ of 2 μg kg^?1. The data showed that the quality and safety of Thai rice largely comply with the requirement for both exports and domestic consumption. According to the Thai National Consumption data, the estimated AFB₁ intake via rice consumption in period I and period II was 0.80 and 0.12 μg kg^?1 bw day^?1, respectively. The potential risk for cancer, based on the recommendation of the JECFA, was estimated to be 0.011 person/year/100,000 people at a mean consumption. Although the risk via consumption of Thai rice seems to be low, the maximum levels of AFB₁ in this staple food suggest that careful monitoring and surveillance of AFB₁ contamination in rice is essential to ensure the safety of rice.     

Use of yeast (<Emphasis Type="Italic">Pichia kudriavzevii</Emphasis>) as a novel feed additive to ameliorate the effects of aflatoxin B<Subscript>1</Subscript> on broiler chicken performance

The aim of this study was to evaluate the efficacy of autochthonous Pichia kudriavzevii as a novel bioadsorbent for aflatoxin B₁ (AFB₁). The selection of this yeast was based on the AFB₁ adsorption capacity previously demonstrated in vitro (Magnoli et al. 2016). One-day-old Cobb broilers (n = 160) were randomly assigned to four dietary treatments (T1: basal diet (B); T2: B + 0.1% yeast; T3: B + AFB₁, 100 μg/kg; T4: B + 0.1% yeast + AFB₁, 100 μg/kg). Performance parameters (average daily weight gain body, average daily consumption, feed conversion ratio, carcass weight, and dead weight), biochemical parameters (albumin, globulin, and albumin/globulin), liver pathological changes, and AFB₁ residual levels in the liver and excreta were evaluated. Significant differences (P < 0.05) in performance parameters were observed among treatments and controls: T3 group showed the lowest average daily body weight gain value while in T4 group, the value of this parameter increased significantly (P < 0.05). T3 and T4 groups showed the lowest and highest values for average daily feed consumption, respectively. The feed conversion ratio (FC) showed no significant differences among treatments. T3 group showed the lowest dead weight and carcass weight compared with T1 group. The biochemical parameters showed no significant differences among treatments. T3 group showed macroscopic and microscopic liver changes compared to the control. Aflatoxin B₁ levels (μg/g) were detected in broiler livers and showed significant differences among treatments (P < 0.05). In conclusion, native P. kudriavzevii incorporation (0.1%) in broiler diets containing AFB₁ was shown to be effective in ameliorating the adverse effects of AFB₁ on production.     

A limited survey of aflatoxin B1 contamination in Indonesian palm kernel cake and copra meal sampled from batches

Samples from large (100–200 tons) batches of palm kernel cake (PKC, n?=?20) and copra meal (CM, n?=?13) were collected at production facilities of four Indonesian feed mill manufacturers and analysed for aflatoxin B₁ (AFB₁) by ELISA. Recoveries using spiked samples ranged from 86 to 113 %, with relative standard deviations of <9 % (PKC) and <6 % (CM). All batches were positive for AFB₁: in PKC, at levels of 5.8–93.1 μg/kg (mean 49 μg/kg), and in CM, at levels of 1.1–147 μg/kg (mean 38.1 μg/kg). AFB₁ levels were, in most batches, below the maximum level (100 μg/kg) recommended by the National Standardisation Agency, Republic of Indonesia. However, about half of the batches exceeded both the European Union and USA regulations for AFB₁ in animal feed. In conclusion, serious efforts are necessary to control production, storage and shipment of palm kernel cake and copra meal for feed purposes, and clearly not only for products intended for export but also to reduce AFB₁ levels in domestic Indonesian feed.     

Saffron (<Emphasis Type="Italic">Crocus sativus</Emphasis> L.) Tea Intake Prevents Learning/Memory Defects and Neurobiochemical Alterations Induced by Aflatoxin B<Subscript>1</Subscript> Exposure in Adult Mice

This study aimed to investigate the potential neurotoxic effects of aflatoxin B₁ (AFB₁) and the preventive effects of saffron. Male Balb-c mice received AFB₁ (0.6 mg/kg/day intraperitoneally for 4 days), saffron infusion (90 mg styles/200 mL, ad libitum access for 2 weeks) or saffron infusion plus AFB₁ (saffron treatment as previously plus 0.6 mg AFB₁/kg/day intraperitoneally for the last 4 days). Control mice were intraperitoneally injected with DMSO:saline (1:1, v/v) during AFB₁ treatment. Learning/memory was assessed by passive avoidance task. The activity of acetylcholinesterase [AChE, salt-(SS)/detergent-soluble(DS) isoforms], butyrylcholinesterase (BuChE, SS/DS isoforms), monoamine oxidase (MAO-A, MAO-B), the levels of lipid peroxidation (malondialdehyde, MDA) and reduced glutathione (GSH), were determined in whole brain (minus cerebellum) and cerebellum. We demonstrate for the first time that AFB₁ administration impaired the memory of adult mice and decreased significantly whole brain AChE and BuChE activity, cerebellar AChE activity and cerebral GSH content. Moreover, MAO isoforms activity in whole brain, MAO-B activity in cerebellum and MDA levels of both tissues were significantly higher after AFB₁ treatment. Pre-treatment with saffron prevented memory decline, activation of MAO-A and MAO-B in whole brain and cerebellum, respectively, and lipid peroxidation triggered by AFB₁. Interestingly, the activity of AChE isoforms in whole brain, DS-AChE in cerebellum and GSH levels of both tissues were further significantly decreased in saffron?+AFB₁-treated mice compared with AFB₁ group. Our findings support the neuroprotective efficacy of saffron against AFB₁ in adult mice.     

Aflatoxin B1 and zearalenone in dairy feeds in Portugal, 2009–2011

This paper presents 3 years of data (2009–2011) on the occurrence of two mycotoxins, aflatoxin B₁ (AFB₁) and zearalenone (ZEA), in samples of feedstuff for dairy cows (n?=?963), ewes (n?=?42), and goats (n?=?131) produced in Portugal. AFB₁ was found in 15 samples of cow feed (1.6 %), 3 samples of ewe feed (2.3 %) and in 2 samples of goat feed (4.8 %). All but two samples contained AFB₁ at levels below the European Union maximum level (5 μg/kg). Nearly half (45 %) of the samples were contaminated with ZEA, but its levels were relatively low, at 5–136.9 μg/kg, well below the European Union guidance value (500 μg/kg).     

Effect of aflatoxin B1 on CD3 T cells andalkaline phosphatase in the intestine of mice

The aim of the study was to determine the effect of repeated applications of aflatoxin B₁ (AFB₁) on immunocompetent cells (CD3 T cells) and alkaline phosphatase in the intestinal mucosa. Mice were orally treated with AFB₁ for 24 days. The mucosa of the intestine showed a significant decrease in the number of CD3 T cells and a significantly lower level activity of alkaline phosphatase on day 24 in AFB₁ treated mice. Similarly, with changes in the small intestine, qualitative haematological parameters were modified in systemic immunity as lymphopenia, and neutropenia, monocytopenia. AFB₁ treated animals showed reduction in body weight gain and increased liver weight. We supposed that changes found in the small intestine are secondary to primary systemic haematological lesions. The decrease in CD3 T cells suggests a connection with the decrease in the host's resistance to infectious diseases. This revised version was published online in June 2006 with corrections to the Cover Date.     

Effect of UV irradiation on aflatoxin reduction: a cytotoxicity evaluation study using human hepatoma cell line

In this proof-of-concept study, the efficacy of a medium-pressure UV (MPUV) lamp source to reduce the concentrations of aflatoxin B₁, aflatoxin B₂, and aflatoxin G₁ (AFB_1, AFB₂, and AFG₁) in pure water is investigated. Irradiation experiments were conducted using a collimated beam system operating between 200 to 360 nm. The optical absorbance of the solution and the irradiance of the lamp are considered in calculating the average fluence rate. Based on these factors, the UV dose was quantified as a product of average fluence rate and treatment time. Known concentrations of aflatoxins were spiked in water and irradiated at UV doses ranging from 0, 1.22, 2.44, 3.66, and 4.88 J cm^?2. The concentration of aflatoxins was determined by HPLC with fluorescence detection. LC-MS/MS product ion scans were used to identify and semi-quantify degraded products of AFB₁, AFB₂, and AFG₁. It was observed that UV irradiation significantly reduced aflatoxins in pure water (p < 0.05). Irradiation doses of 4.88 J cm^?2 reduced concentrations 67.22% for AFG₁, 29.77% for AFB₂, and 98.25% for AFB₁ (p < 0.05). Using this technique, an overall reduction of total aflatoxin content of ≈95% (p < 0.05) was achieved. We hypothesize that the formation of ˙OH radicals initiated by UV light may have caused photolysis of AFB₁, AFB₂, and AFG₁ molecules. In cell culture studies, our results demonstrated that the increase of UV dosage decreased the aflatoxin-induced cytotoxicity in HepG₂ cells. Therefore, our research finding suggests that UV irradiation can be used as an effective technique for the reduction of aflatoxins.     

The effects of aflatoxin B1 on growth hormone regulated gene-1 and interaction between DNA and aflatoxin B1 in broiler chickens during hatching

Many types of aflatoxin cause problems for both public and animal health. Aflatoxin B₁ (AFB₁) is the most toxic and commonly encountered fungal toxin that appears in poultry feed and in feeds stored under unsuitable conditions. AFB₁ decreases feed quality, egg production and fertility of hatching eggs. Also, AFB₁ alters the development of embryos by infecting eggs. We investigated using sequence analysis the changes caused by different concentrations of AFB₁ on the promoter sequences of the growth hormone regulated gene-1 (GHRG-1) in chick embryo at 13, 17, 19 and 21 days incubation. DNA isolated from the liver of chick embryos treated with different concentrations of AFB₁ was separated using agarose gel electrophoresis to detect apoptosis, and DNA interaction with AFB₁ was investigated using plasmids to detect changes in electrophoretic mobility and their effects on DNA. Base changes of the promoter sequences of GHRG-1 in 5 ng/egg, 15 ng/egg and 40 ng/egg doses of AFB₁ were increased on day 19 compared to base changes of the same AFB₁ doses on day 13. We also found that AFB at different concentrations changed the mobility of DNA by binding to it, and that high doses of AFB1 destroyed DNA. The DNA interaction study using plasmid demonstrated that AFB₁ at high doses was bound to plasmid DNA, slowed its mobility and inhibited restriction cuts.     

Effect of treatment of cow’s urine “Gomutra” and antioxidants in alleviating the lindane-induced oxidative stress in kidney of Swiss mice (Mus musculus)

The study aimed to evaluate the effect of cow urine and combination of antioxidants against lindane induced oxidative stress in Swiss mice. Male healthy mice, 8–10 weeks old, weighing 30 ± 5 g were randomly selected and divided into eight groups, namely, control (C); lindane (L); antioxidant (A), antioxidant+lindane (A+L), cow urine (U), cow urine+lindane (U+L), cow urine+antioxidants (U+A) and cow urine+antioxidants+lindane (U+A+L). Group C animals were administered only the vehicle (olive oil); doses selected for other treatments were: lindane: 40 mg/kg b.w.; antioxidants: 125 mg/kg b.w. (vitamin C: 50 mg/kg b.w., vitamin E: 50 mg/kg b.w., α-lipoic acid: 25 mg/kg b.w.) and cow urine: 0.25 ml/kg b.w. In group A+L and U+L antioxidants and cow urine were administered 1 h prior to lindane administration and in group U+A and U+A+L cow urine was administered 10 min before antioxidants. All treatments were administered orally continuously for 60 days. Lindane treated group showed increased lipid peroxidation, whereas glutathione, glutathione peroxidase, superoxide dismutase, catalase, protein and endogenous levels of vitamin C and E were significantly decreased compared to control. Administration of cow urine and antioxidants alleviated the levels of these biochemical parameters.     

Effect of dietary β-1,3 glucan on immune responses and disease resistance of healthy and aflatoxin B1-induced immunocompromised rohu (Labeo rohita Hamilton)

The immunostimulant β-1,3 glucan was fed at 0·1% in feed for 7 days to healthy and aflatoxin B₁(AFB₁)-induced immunocompromised fish, Labeo rohita (one of the major tropical carp species), in a 60 day trial. The effects of AFB₁, glucan and their interactions on non-specific and specific immunity levels and disease resistance of fish were studied. A single intraperitoneal injection of AFB₁at 1·25 mg kg⁻¹body weight) caused a significant (P< 0·05) reduction in non-specific immunity as measured through neutrophil phagocytic indices, serum bactericidal activity, and specific immunity as measured through bacterial agglutination titre against Edwardsiella tarda, as well as reduced protection against Aeromonas hydrophila challenge in comparison to control fish which were exposed neither to aflatoxin nor to glucan. Feeding of glucan to healthy fish raised the non-specific and specific immunity level and protection against bacterial infection compared with the control. Feeding of glucan to AFB₁-induced immunocompromised fish for 7 days significantly raised the degree of resistance against A. hydrophila challenge and the non-specific immunity level in comparison to non-treated AFB₁exposed fish. Although feeding of glucan was able to increase specific immunity, al measured through haemagglutination titre against sheep red blood cells, and bacterial (E. tarda) agglutination titre in healthy fish in comparison to all other groups, no significant increase in specific immunity to the aflatoxin-exposed group was seen.     

Studies on the embryotoxicity and mutagenicity of mycotoxins

Embryotoxicity: Aflatoxin B₁(AFB₁), G₁ (AFG₁), and Patulin (PA) were investigated in NMRI mice for embryotoxic and teratogenic activity. These three mycotoxins were injected intraperitoneally or given orally on day 12 and 13 of pregnancy. AFB₁ (15, 45, and 90 mg/kg ip or 45 mg/kg po) produced a moderate retardation in the fetal development and a dose related increase of cleft palates, wavy ribs, and diaphragm changes. The effects after injection of AFG₁ (45 and 90 mg/kg ip) were reduction of fetal weights, increase of diaphragm changes, and malformations of kidneys. PA (1.25, 2.5, and 3.75 mg/kg ip or 3.75 mg/kg po) elevated the rate of cleft palates after 3.75mg/kg. In the dominant lethal assay neither PA (2.5 and 5 mg/kg ip) nor AFB₁) (15 and 45 mg/kg ip) increased the frequency of the dominant lethal mutations. Both mycotoxins showed no mutagenic activity in this test system. The capability of AFB₁, AFG₁, and PA to induce chromosome damages in vivo was tested in the Chinese Hamster by examination of bone marrow cells, each after two oral doses (AFB₁: 12.5 and 25 mg/kg; 25 and 50 mg/kg; PA: 10 and 20 mg/kg). The three mycotoxins induced chromosome aberrations in the following order of activity: PA > AFB₁ > AFG₁.     

Study of aflatoxin B1 production by Aspergillus parasiticus in bee pollen of Greek origin

Aflatoxin B₁ (AFB₁) is a carcinogenic metabolite produced by certain Aspergillus species such as A. parasiticus and A. flavus. The beneficial properties of bee pollen have transformed this commodity into an increasingly frequent component of the human diet. As bee pollen is a substrate on which aflatoxigenic fungi can grow, AFB₁ production is likely. In the present study, we describe a method for aflatoxin B₁ determination in bee pollen utilising high pressure liquid chromatography (HPLC) with a fluorescence detector (FD). The recovery factor of the method was found to be 111% (RSD% 1.61), while the detection limit (LOD) was 0.08 ng AFB₁/g. An additional aim of this study was to investigate the growth of A. parasiticus and AFB₁ production in bee pollen. Results indicated that no mycelial growth was observed and no AFB₁ was detected in bee pollen samples containing natural microbiota throughout the entire observation period (20 days). In contrast, AFB₁ production in treated bee pollen samples (15 g pollen/flask) inoculated with A. parasiticus was significantly higher (p?≤?0.05) compared to control samples (treated but not inoculated) throughout the entire incubation period, while no mycelial growth was apparent. Maximum production was observed on the 12th day (79.29 ng AFB₁/flask and 32.44 ng AFB₁/flask for inoculated and non-inoculated bee pollen, respectively). As a result, AFB₁ production in bee pollen is likely even following a minor contamination, which could occur randomly.