Effects of aflatoxin B1 on embryo fetal development in rabbits

Neurotoxic mechanisms of mycotoxins: Focus on aflatoxin B1 and T-2 toxin

Aflatoxin B1 (AFB1) and T-2 toxin are commonly found in animal feed and stored grain, posing a serious threat to human and animal health. Mycotoxins can penetrate brain tissue by compromising the blood-brain barrier, triggering oxidative stress and neuroinflammation, and leading to oxidative damage and apoptosis of brain cells. The potential neurotoxic mechanisms of AFB1 and T-2 toxin were discussed by summarizing the relevant research reports from the past ten years. AFB1 and T-2 toxin cause neuronal damage in the cerebral cortex and hippocampus, leading to synaptic transmission dysfunction, ultimately impairing the nervous system function of the body. The toxic mechanism is related to excessive reactive oxygen species (ROS), oxidative stress, mitochondrial dysfunction, apoptosis, autophagy, and an exaggerated inflammatory response. After passing through the blood-brain barrier, toxins can directly affect glial cells, alter the activation state of microglia and astrocytes, thereby promoting brain inflammation, disrupting the blood-brain barrier, and influencing the synaptic transmission process. We discussed the diverse effects of various concentrations of toxins and different modes of exposure on neurotoxicity. In addition, toxins can also cross the placental barrier, causing neurotoxic symptoms in offspring, as demonstrated in various species. Our goal is to uncover the underlying mechanisms of the neurotoxicity of AFB1 and T-2 toxin and to provide insights for future research, including investigating the impact of mycotoxins on interactions between microglia and astrocytes.

An overview of mycotoxicoses in rabbits

Mycotoxicoses are usually a consideration in large animal species but can affect companion animals as well. Due to increasing interest and the ease of using rabbits as laboratory models, a growing number of published experimental studies discuss the effects of various mycotoxins on this species. However, the available evidence is fragmented and heterogeneous, and has not recently been collated in a review, to my knowledge. Although mycotoxicoses in rabbits are typically subclinical, clinical signs can include weight loss, anorexia, gastrointestinal disorders, stunted growth, reproductive abnormalities, and susceptibility to infections. An antemortem diagnosis typically relies on a comprehensive clinical history, and assessment of clinical signs and relevant laboratory findings, with confirmation of exposure achieved through the measurement of mycotoxin concentrations in feed or target organs. My review focuses on the clinicopathologic and histopathologic effects of the mycotoxins most important in rabbits, including fumonisins, ochratoxins, aflatoxins, trichothecenes, and zearalenone. This review offers a thorough overview of the effects of mycotoxins in rabbits, serving as a one-stop resource for veterinary practitioners, diagnosticians, and researchers.

Aflatoxin B1 induces infertility, fetal deformities, and potential therapies

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

A Novel Multicellular Placental Barrier Model to Investigate the Effect of Maternal Aflatoxin B1 Exposure on Fetal-Side Neural Stem Cells

Ingestion of food toxins such as aflatoxin B₁ (AFB₁) during pregnancy may impair fetal neurodevelopment. However, animal model results may not be accurate due to the species' differences, and testing on humans is ethically impermissible. Here, we developed an in vitro human maternal-fetal multicellular model composed of a human hepatic compartment, a bilayer placental barrier, and a human fetal central nervous system compartment using neural stem cells (NSCs) to investigate the effect of AFB₁ on fetal-side NSCs. AFB₁ passed through the HepG2 hepatocellular carcinoma cells to mimic the maternal metabolic effects. Importantly, even at the limited concentration (0.0641 ± 0.0046 μM) of AFB_1, close to the national safety level standard of China (GB-2761-2011), the mixture of AFB₁ crossing the placental barrier induced NSC apoptosis. The level of reactive oxygen species in NSCs was significantly elevated and the cell membrane was damaged, causing the release of intracellular lactate dehydrogenase (p < 0.05). The comet experiment and γ-H2AX immunofluorescence assay showed that AFB₁ caused significant DNA damage to NSCs (p < 0.05). This study provided a new model for the toxicological evaluation of the effect of food mycotoxin exposure during pregnancy on fetal neurodevelopment.

Maternal dietary exposure to mycotoxin aflatoxin B1 promotes intestinal immune alterations and microbiota modifications increasing infection susceptibility in mouse offspring

Mycotoxins are secondary metabolites produced by fungi occurring in food that are toxic to animals and humans. Early-life mycotoxins exposure has been linked to diverse pathologies. However, how maternal exposure to mycotoxins impacts on the intestinal barrier function of progeny has not been explored. Here, exposure of pregnant and lactating C57Bl/6J female mice to aflatoxin B₁ (AFB₁; 400 μg/kg body weight/day; 3 times a week) in gelatine pellets, from embryonic day (E)11.5 until weaning (postnatal day 21), led to gut immunological changes in progeny. The results showed an overall increase of lymphocyte number in intestine, a reduction of expression of epithelial genes related to microbial defence, as well as a decrease in cytokine production by intestinal type 2 innate lymphoid cells (ILC2). While susceptibility to chemically induced colitis was not worsened, immune alterations were associated with changes in gut microbiota and with a higher vulnerability to infection by the protozoan Eimeria vermiformis at early-life. Together these results show that maternal dietary exposure to AFB₁ can dampen intestinal barrier homeostasis in offspring decreasing their capability to tackle intestinal pathogens. These data provide insights to understand AFB₁ potential harmfulness in early-life health in the context of intestinal infections.

Chronic aflatoxin exposure during pregnancy is associated with lower fetal growth trajectories: a prospective cohort from the Butajira Nutrition, Mental Health, and Pregnancy (BUNMAP) Study in rural Ethiopia

BACKGROUND

Aflatoxins are toxic secondary metabolites produced by Aspergillus fungi, which are ubiquitously present in the food supplies of low- and middle-income countries. Studies of maternal aflatoxin exposure and fetal outcomes are mainly focused on size at birth and the effect on intrauterine fetal growth has not been assessed.

OBJECTIVES

In the present study, we examined the association between chronic aflatoxin exposure during pregnancy and fetal growth trajectories in a rural setting in Ethiopia.

METHODS

In a prospective cohort study, we enrolled 492 pregnant females, with a singleton pregnancy and before 28 wk of gestation. Serum aflatoxin B1-lysine concentration was measured using LC-tandem MS. Three rounds of ultrasound measurements were conducted to estimate fetal weight at mean ± SD gestational age weeks of 19.1 ± 3.71, 28.5 ± 3.51, and 34.5 ± 2.44. Estimated fetal weight was expressed in centiles using the International Fetal and Newborn Growth Consortium for the 21st Century (INTERGROWTH-21st) reference. We fitted a multivariable linear mixed-effects model to estimate the rate of fetal growth between aflatoxin-exposed (i.e., aflatoxin B1-lysine concentration above or equal to the limit of detection) and unexposed mothers in the study.

RESULTS

Mothers had a mean ± SD age of 26.0 ± 4.58 y. The median (25th, 75th percentile) serum aflatoxin B1-lysine concentration was 12.6 (0.93, 96.9) pg/mg albumin, and aflatoxin exposure was observed in 86.6% of maternal blood samples. Eighty-five percent of the females enrolled provided at least 2 ultrasound measurements for analysis. On average, the aflatoxin-exposed group had a significantly lower change over time in fetal weight-for-gestational-age centile than the unexposed group (ß = -0.92; 95% CI: -1.77, -0.06 centiles/week; P = 0.037).

CONCLUSIONS

Chronic maternal aflatoxin exposure is associated with lower fetal growth over time. Our findings emphasize the importance of nutrition-sensitive strategies to mitigate dietary aflatoxin exposure and adopting food safety measures in low-income settings, in particular during the fetal period of development.

Comparison Evaluation of the Biological Effects of Sterigmatocystin and Aflatoxin B1 Utilizing SOS-Chromotest and a Novel Zebrafish (Danio rerio) Embryo Microinjection Method

Aflatoxin B1 (AFB1) is a potent mycotoxin and natural carcinogen. The primary producers of AFB1 are Aspergillus flavus and A. parasiticus. Sterigmatocystin (STC), another mycotoxin, shares its biosynthetic pathway with aflatoxins. While there are abundant data on the biological effects of AFB1, STC is not well characterised. According to published data, AFB1 is more harmful to biological systems than STC. It has been suggested that STC is about one-tenth as potent a mutagen as AFB1 as measured by the Ames test. In this research, the biological effects of S9 rat liver homogenate-activated and non-activated STC and AFB1 were compared using two different biomonitoring systems, SOS-Chromotest and a recently developed microinjection zebrafish embryo method. When comparing the treatments, activated STC caused the highest mortality and number of DNA strand breaks across all injected volumes. Based on the E. coli SOS-Chromotest, the two toxins exerted the same genotoxicities. Moreover, according to the newly developed zebrafish microinjection method, STC appeared more toxic than AFB1. The scarce information correlating AFB1 and STC toxicity suggests that AFB1 is a more potent genotoxin than STC. Our findings contradict this assumption and illustrate the need for more complex biomonitoring systems for mycotoxin risk assessment.

Embryonic exposure to low concentrations of aflatoxin B1 triggers global transcriptomic changes, defective yolk lipid mobilization, abnormal gastrointestinal tract development and inflammation in zebrafish

Aflatoxin B1-contaminated feeds and foods induce various health problems in domesticated animals and humans, including tumor development and hepatotoxicity. Aflatoxin B1 also has embryotoxic effects in different livestock species and humans. However, it is difficult to distinguish between the indirect, maternally-mediated toxic effects and the direct embryotoxicity of aflatoxin B1 in mammals. In the present study, we investigated the aflatoxin B1-induced direct embryotoxic effects in a zebrafish embryo model system combining toxicological, transcriptomic, immunological, and biochemical approaches. Embryonic exposure to aflatoxin B1 induced significant changes at the transcriptome level resulting in elevated expression of inflammatory gene network and repression of lipid metabolism and gastrointestinal tract development-related gene sets. According to the gene expression changes, massive neutrophil granulocyte influx, elevated nitric oxide production, and yolk lipid accumulation were observed in the abdominal region of aflatoxin B1-exposed larvae. In parallel, aflatoxin B1-induced defective gastrointestinal tract development and reduced L-arginine level were found in our model system. Our results revealed the complex direct embryotoxic effects of aflatoxin B1, including inhibited lipid utilization, defective intestinal development, and inflammation.

Aflatoxin B1 interferes with embryonic liver development: Involvement of p53 signaling and apoptosis in zebrafish

Aflatoxin B₁ (AFB₁), a naturally occurring mycotoxin, is present in human placenta and cord blood. AFB₁ at concentrations found in contaminated food commodities (0.25 and 0.5 μM) did not alter the spontaneous movement, heart rate, hatchability, or morphology of embryonic zebrafish. However, around 86 % of 0.25 μM AFB₁-treated embryos had livers of reduced size, and AFB₁ disrupted the hepatocyte structures, according to histological analysis. Additionally, AFB₁ treatment that begins at any stage before 72 h post-fertilization (hpf) effectively reduced the size of embryonic livers. In hepatic areas, AFB₁ suppressed the expression of Hhex and Prox1, which are two critical transcriptional factors for initiating hepatoblast specification. KEGG analysis based on transcriptome profiling indicated that p53 signaling and apoptosis are the only observed pathways in AFB₁-treated embryos. AFB₁ at 0.5 μM significantly activated the expression of tp53, mdm2, puma, noxa, pidd1, and gadd45aa genes that are related to the p53 pathway and also that of baxa, casp 8 and casp 3a in the apoptotic process. TUNEL staining demonstrated that AFB₁ triggered the apoptosis of embryonic hepatocytes in a dose-dependent manner. These results indicate that the deficiency of both hhex and prox1 as well as hepatocyte apoptosis via the p53-Puma/Noxa-Bax axis may contribute to the embryonic liver shrinkage that is caused by AFB_1.

Detoxification of aflatoxin B1 by Stenotrophomonas sp. CW117 and characterization the thermophilic degradation process

Mycotoxins are high toxic, widely distributed contaminants in foodstuff. In this study, a aflatoxin B1 (AFB1) degrading strain S. acidoaminiphila CW117 was screened, and its detoxification characteristics were investigated. Substrate AFB1 at 45 μg/L was degraded by CW117 within 24 h; meanwhile, 4.1 mg/L AFB1 was almost degraded within 48 h. After 24 h degradation, the biotoxicity of the detoxified culture was eliminated. Strain CW117 efficient degradation to AFB1 (especially to low AFB1 concentrations) suggested its potential significance to detoxification development on food and feedstuff. The active degradation components present in the cell-free supernatant. The degradation ratio increased constantly with increasing incubation temperature raised (0-90 °C) and was even stable at 90 °C. Degradation was optimal at pH 6-7, and was only partially inhibited by metal-chelators (EDTA and EGTA), proteinase K, and a protein denaturant (sodium dodecyl sulfate, SDS). The recombinant laccase rLC1 (0.5 mg/mL) from CW117 degraded 29.3% of AFB1 within 24 h; however, the cell-free supernatant degraded 76.7% of the toxin in same time, with much lower protein content. The results indicated the CW117 degrades AFB1 via a combination of enzymes and micro-molecule oxides.

Chronic and Acute Toxicities of Aflatoxins: Mechanisms of Action

There are presently more than 18 known aflatoxins most of which have been insufficiently studied for their incidence, health-risk, and mechanisms of toxicity to allow effective intervention and control means that would significantly and sustainably reduce their incidence and adverse effects on health and economy. Among these, aflatoxin B1 (AFB1) has been by far the most studied; yet, many aspects of the range and mechanisms of the diseases it causes remain to be elucidated. Its mutagenicity, tumorigenicity, and carcinogenicity-which are the best known-still suffer from limitations regarding the relative contribution of the oxidative stress and the reactive epoxide derivative (Aflatoxin-exo 8,9-epoxide) in the induction of the diseases, as well as its metabolic and synthesis pathways. Additionally, despite the well-established additive effects for carcinogenicity between AFB1 and other risk factors, e.g., hepatitis viruses B and C, and the hepatotoxic algal microcystins, the mechanisms of this synergy remain unclear. This study reviews the most recent advances in the field of the mechanisms of toxicity of aflatoxins and the adverse health effects that they cause in humans and animals.

Interference of mycotoxin binders with ELISA, HPLC and LC-MS/MS analysis of aflatoxins in maize and maize gluten

The aim of this study was to investigate the impact of mycotoxin binders on the determination of aflatoxins in maize and maize gluten using various analytical methods, including ELISA, HPLC and LC-MS/MS. Three types of commercially available mycotoxin binders, yeast cell wall, mineral, and a mixture of mineral and bacterium, were investigated at inclusion levels of 0.1%, 0.2% and 0.4%. The binders were added to maize and maize gluten contaminated with aflatoxins at concentrations between 6.9 and 26.7 μg kg^-1. The samples were analysed and the values were compared with corresponding controls (samples without binders) using ANOVA. The yeast cell wall binder had no significant effect (p=0.05) on the concentration of aflatoxins measured in either maize or maize gluten at any of the three inclusion levels, regardless of which analytical method was used. The mineral binder and the mixed mineral and bacterium binder had no significant effect (p=0.05) on the measured aflatoxin concentrations in either maize or maize gluten at any of the three inclusion levels when analysis was conducted using LC-MS/MS. Inclusion of these binders resulted in significant lower (p<0.01) detection of aflatoxins in both maize and maize gluten when analysis was conducted using ELISA; the effect was dose-dependent. They also resulted in significant lower detection of aflatoxins in maize extracted by methanol/water (70/30 v/v) (p<0.0001) and in maize gluten extracted by acetonitrile/water (80/20 v/v) (p<0.05) when analysis was conducted using HPLC. However, neither the mineral binder nor the mixed mineral and bacterium binder had significant effects (p=0.05) on aflatoxin concentrations measured in maize using HPLC, when extracted by acetonitrile/water (80/20 v/v). The study demonstrated that mycotoxin binders could result in underestimation of the levels of aflatoxin contamination, depending on the nature of the binder, the extraction solvent used in the analytical method, and the composition of tested sample.

Chronic neurodegeneration by aflatoxin B1 depends on alterations of brain enzyme activity and immunoexpression of astrocyte in male rats

Aflatoxin B1 poses the greatest risk among the mycotoxins to target-organisms particularly human, however, no studies addressed the neurotoxicity of chronic exposure of aflatoxin. The oral dose level 1/600th of LD50 for 30, 60, and 90 days was used for three aflatoxin groups, respective to negative and vehicle control groups. Activity levels of brain antioxidants viz: superoxide dismutase, catalase, glutathione, and glutathione peroxidase significantly decreased in the three experimental durations in time-dependent trend, in contrast, lipid peroxidation showed a significant increase compared to controls. Significantly, chronic-dependent increase trend was noticed in the AF60 and AF90 group for acid phosphatase (16.1%, 35.2%), alkaline phosphatase (32.1%, 50.8%), aspartate aminotransferase (38.7%, 120.0%) and lactate dehydrogenase (30.6%, 42.1%) activities, respectively. However, a significant 23.7% decrease in the brain creatine kinase activity following 90 days of AFB1administration. Chronic administration of aflatoxin also causes alterations in activities of protein carbonyl with a maximum increase (twofold) after 90 days. Further, histopathological and immunohistochemical results confirmed time-related vasodilation, necrosis and astrocytes gliosis by high glial fibrillary acidic protein immunostaining in response to AFB1. These findings infer that long-term exposure to AFB1 results in several pathophysiological circumstances in a duration-dependent manner concerning neurodegeneration especially Alzheimer's disease.

Melatonin protects in vitro matured porcine oocytes from toxicity of Aflatoxin B1

Aflatoxin B1 (AFB1) is a major food and feed contaminant that threaten public health. Previous studies indicate that AFB1 exposure disrupted oocyte maturation. However, an effective and feasible method is unavailable for protecting oocytes against toxicity of AFB1. In the present study, using in vitro matured porcine oocytes and parthenogenetic embryos as model, we confirmed that AFB1 exposure during in vitro oocyte maturation (IVM) significantly impaired both nuclear and cytoplasmic maturation in a dose- and time-dependent manner. The different concentrations of melatonin were also tested for their protective effects on oocytes against the AFB1-induced toxicity. Our results showed that supplementation of a relative high concentration of melatonin (10^-3 mol/L) during IVM efficiently reversed the impaired development rate and blastocyst quality, to the levels comparable to those of the control group. Further analysis indicated that melatonin application efficiently alleviated reactive oxygen species accumulation and initiation of apoptosis induced by AFB1 exposure. In addition, disrupted GSH/GPX system, as well as inhibited mitochondrial DNA (mtDNA) replication and mitochondrial biogenesis in AFB1-treated oocytes, can be notably reversed by melatonin application. Furthermore, cumulus cells may be important in mediating the toxicity of AFB1 to oocytes, and the metabolism of AFB1 in cumulus cells can be depressed by melatonin. To the best of our knowledge, this is the first report to confirm that melatonin application can efficiently protect oocytes from AFB1-induced toxicity. Our study provides a promising and practical strategy for alleviating or reversing AFB1-induced female reproductive toxicity in both clinical treatment and domestic reproductive management.

Effect of aflatoxin B1 on blood serum oestradiol-17β and progesterone concentrations during the luteal phase and the synchronized oestrus of goats

The effect of prolonged aflatoxin B₁ (AFB₁) administration on blood serum oestradiol-17β and progesterone concentrations in goats during the luteal phase and the synchronized oestrus was investigated. Thirty-six Greek indigenous primiparous goats were used, during the oestrus period; 12 goats received, per os, 50 μg (treated group T50) and 12 goats received 100 μg (treated group T100) AFB₁/day/head, respectively, for approximately 1.5 month, while 12 goats served as controls (C). On day 36 of the experiment, each goat was injected, i.m, 0.5 ml prostaglandin F_2α (PGF_2α). Blood samples were collected from each goat twice a week, before PGF_2α injection, as well as every 4 hours from the onset to the end of the synchronized oestrus. Oestradiol-17β and progesterone concentrations in blood serum were determined using radioimmunoassay. During the whole luteal(s) phase(s), linear regression analysis revealed a significant negative dependence (P < 0.05) of oestradiol-17β and a significant positive dependence (P < 0.05) of progesterone over group (C = 0, T50 = 50, T100 = 100), in a dose dependent manner. During the synchronized oestrus, multiple linear regression analysis revealed a significant negative dependence (P < 0.05) of oestradiol-17β, as well as a significant positive dependence (P < 0.05) of progesterone over group (C = 0, T50 = 50, T100 = 100) and over time (hours, from the onset to the end of the synchronized oestrus). No significant differences were noticed among the three groups, regarding the body weight of the goats from the onset to the end of AFB₁ administration, the occurrence or the duration of the synchronized oestrus presented by the goats (P > 0.05). In conclusion, prolonged AFB₁ administration at doses of 100 or even of 50 μg/day/head changes the hormonal pattern in blood during the luteal phase and the synchronized oestrus of goats, being in oestrus period.

Worldwide Occurrence of Mycotoxins in Cereals and Cereal-Derived Food Products: Public Health Perspectives of Their Co-occurrence

Cereal grains and their processed food products are frequently contaminated with mycotoxins. Among many, five major mycotoxins of aflatoxins, ochratoxins, fumonisins, deoxynivalenol, and zearalenone are of significant public health concern as they can cause adverse effects in humans. Being airborne or soilborne, the cosmopolitan nature of mycotoxigenic fungi contribute to the worldwide occurrence of mycotoxins. On the basis of the global occurrence data reported during the past 10 years, the incidences and maximum levels in raw cereal grains were 55% and 1642 μg/kg for aflatoxins, 29% and 1164 μg/kg for ochratoxin A, 61% and 71,121 μg/kg for fumonisins, 58% and 41,157 μg/kg, for deoxynivalenol, and 46% and 3049 μg/kg for zearalenone. The concentrations of mycotoxins tend to be lower in processed food products; the incidences varied depending on the individual mycotoxins, possibly due to the varying stability during processing and distribution of mycotoxins. It should be noted that more than one mycotoxin, produced by a single or several fungal species, may occur in various combinations in a given sample or food. Most studies reported additive or synergistic effects, suggesting that these mixtures may pose a significant threat to public health, particularly to infants and young children. Therefore, information on the co-occurrence of mycotoxins and their interactive toxicity is summarized in this paper.

Aflatoxin Exposure During Pregnancy, Maternal Anemia, and Adverse Birth Outcomes

Pregnant women and their developing fetuses are vulnerable to multiple environmental insults, including exposure to aflatoxin, a mycotoxin that may contaminate as much as 25% of the world food supply. We reviewed and integrated findings from studies of aflatoxin exposure during pregnancy and evaluated potential links to adverse pregnancy outcomes. We identified 27 studies (10 human cross-sectional studies and 17 animal studies) assessing the relationship between aflatoxin exposure and adverse birth outcomes or anemia. Findings suggest that aflatoxin exposure during pregnancy may impair fetal growth. Only one human study investigated aflatoxin exposure and prematurity, and no studies investigated its relationship with pregnancy loss, but animal studies suggest aflatoxin exposure may increase risk for prematurity and pregnancy loss. The fetus could be affected by maternal aflatoxin exposure through direct toxicity as well as indirect toxicity, via maternal systemic inflammation, impaired placental growth, or elevation of placental cytokines. The cytotoxic and systemic effects of aflatoxin could plausibly mediate maternal anemia, intrauterine growth restriction, fetal loss, and preterm birth. Given the widespread exposure to this toxin in developing countries, longitudinal studies in pregnant women are needed to provide stronger evidence for the role of aflatoxin in adverse pregnancy outcomes, and to explore biological mechanisms. Potential pathways for intervention to reduce aflatoxin exposure are urgently needed, and this might reduce the global burden of stillbirth, preterm birth, and low birthweight.

Prenatal exposure to aflatoxin B1: developmental, behavioral, and reproductive alterations in male rats

Previous studies have shown that aflatoxin B1 (AfB1) inhibits androgen biosynthesis as a result of its ability to form a high-affinity complex with the steroidogenic acute regulatory protein. The results of the present study demonstrate the postnatal effects of in utero exposure to AfB1 in the rat. Pregnant Wistar rats were given 10, 20, or 50 μg AfB1/kg body weight daily from gestation day (GD) 12 to GD 19. At parturition, newborns were observed for clinical signs and survival. All animals were born alive and initially appeared to be active. Male pups from control and AfB1-exposed animals were weaned and maintained up to postnatal day (PD) 100. Litter size, birth weight, sex ratio, survival rate, and crown-rump length of the pups were significantly decreased in AfB1-exposed rats when compared to controls. Elapsed time (days) for testes to descend into the scrotal sac was significantly delayed in experimental pups when compared to control pups. Behavioral observations such as cliff avoidance, negative geotaxis, surface rightening activity, ascending wire mesh, open field behavior, and exploratory and locomotory activities were significantly impaired in experimental pups. Body weights and the indices of testis, cauda epididymis, prostate, seminal vesicles, and liver were significantly reduced on PD 100 in male rats exposed to AfB1 during embryonic development when compared with controls. Significant reduction in the testicular daily sperm production, epididymal sperm count, and number of viable, motile, and hypo-osmotic tail coiled sperm was observed in experimental rats. The levels of serum testosterone and activity levels of testicular hydroxysteroid dehydrogenases were significantly decreased in a dose-dependent manner with a significant increase in the serum follicle-stimulating hormone and luteinizing hormone in experimental rats. Deterioration in the testicular and cauda epididymal architecture was observed in experimental rats. The results of fertility studies revealed a significant decrease in the mating index in experimental rats with an increase in the pre- and post-implantation losses in rats mated with prenatal AfB1-exposed males, indicating poor male reproductive performance. These results indicate that in utero exposure to AfB1 severely compromised postnatal development of neonatal rats, and caused a delay in testes descent and reduction in steroidogenesis and spermatogenesis that were accomplished by suppressed reproduction at adulthood.

Effects of Bacillus subtilis ANSB060 on growth performance, meat quality and aflatoxin residues in broilers fed moldy peanut meal naturally contaminated with aflatoxins

This study was conducted to investigate the toxic effects of aflatoxins and the efficacy of Bacillus subtilis ANSB060 for the amelioration of aflatoxicosis in broiler chickens. Six replicates of ten broilers each were assigned to one of seven dietary treatments, which were labeled C0 (basal diet); M0 (basal diet containing moldy peanut meal); C500 and C1000 (C0+500 or 1000 g/t aflatoxin biodegradation preparations, composed mainly of ANSB060); and M500, M1000 and M2000 (M0+500, 1000 or 2000 g/t aflatoxin biodegradation preparations). The concentrations of aflatoxin B₁, B₂, G₁ and G₂ in the moldy diets (M0, M500, M100 and M2000) fluctuated around 70.7±1.3, 11.0±1.5, 6.5±0.8 and 2.0±0.3 μg/kg, respectively. The results showed that the M0 diet caused a significant decrease in average daily weight gain and increased feed requirements, with a gain ratio increasing from d 8 to 42, deterioration in meat quality and aflatoxin residues in broilers' livers as compared with the C0 diet. The addition of ANSB060 to the aflatoxin-contaminated diets offset these negative effects, leading to the conclusion that ANSB060 has a protective effect on growth performance and meat quality while reducing the amount of aflatoxin residues in the livers of broilers fed naturally moldy peanut meal.

Flavonoid hesperidin protects neural crest cells from death caused by aflatoxin B(1)

The neural crest (NC) corresponds to a collection of multipotent and oligopotent progenitors endowed with both neural and mesenchymal potentials. The derivatives of the NC at trunk level include neurons and glial cells of the peripheral nervous system. Despite the well-known influence of aflatoxins on the development of cancer, the issue of whether they also influence NC cells has not been yet addressed. In the present work, we have investigated the effects of aflatoxin B(1) on quail NC cells and the concomitant effects of the flavonoid hesperidin associated with this mycotoxin. We show for the first time that aflatoxin B(1) decreases the viability and the total number of glial and neuronal cells/field, although their proportions in relation to the total number of cells were not altered. Therefore, aflatoxin has no effect on NC differentiation. However, this compound was able to reduce NC proliferation and NC survival. Furthermore, the co-administration of hesperidin, a well-known polyphenolic protector of cell death, partially prevented the effect of aflatoxin B(1) . Taken together, our results demonstrate that aflatoxin B(1) is toxic to NC cells, an effect partially prevented by the flavonoid hesperidin. This study may contribute to the understanding of the effects of these compounds during early embryonic development and offer potentially more assertive diets and treatments for pregnant animals.

Renin mRNA is upregulated in testes and testicular cells in response to treatment with aflatoxin B1

Aflatoxin B(1) (AFB(1)) has been shown to affect fertility in many species; however, the exact molecular mechanisms associated with the disruption are not known. Our objectives were to determine changes in testicular gene expression due to exposure to AFB(1) and to investigate which cell types were affected by treatment with AFB(1). Male mice 4 wk of age were administered a daily placebo (control; N = 9) or 50 μg/kg AFB(1) (AFB(1) treated; N = 10) daily for 45 days. Males were then mated to four females each for 8 days. Male mice were characterized as being "Tolerant" (N = 3) or "Intolerant" (N = 3) to the effects of AFB(1) based on positive terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining in the testes and the number of pups sired. Tolerant males produced a similar average number of fetuses (mean ± SEM) (12.5 ± 1.2) per male as selected control males (13.4 ± 1.2), but more fetuses (P = 0.01) than Intolerant males (7.6 ± 1.2). The number of terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells in Intolerant males tended to be (P = 0.10) greater (136.5 ± 27.2) than in Tolerant (55.0 ± 22.2) and selected control (54.3 ± 22.2) males. Affymetrix microarray (Sunnyvale, CA, USA) analysis revealed differential expression (P < 0.05) of 193 extra cellular space and signaling genes, 49 signal transduction genes, 45 immune regulation genes, and 230 cell differentiation genes in the testis. Renin was commonly represented amongst many clusters and was chosen for further analyses. Upregulation (P < 0.001) of Renin in Tolerant mice (N = 3) compared with Intolerant mice (N = 3) was confirmed by real-time reverse transcription polymerase chain reaction (RT-PCR) (P = 0.05). This upregulation (P = 0.01) was also observed in representative AFB(1) treated males (N = 8) compared with control males (N = 8) selected for real-time reverse transcription polymerase chain reaction analysis. Spermatogonia cultured in vitro and treated with 0, 5, 10, or 20 μg/mL AFB(1) (N = 6 per treatment) resulted in a 10-fold upregulation (P = 0.01) of Renin message at the 20 μg/mL level, whereas Leydig tumor cells showed similar differences (P = 0.03) in message for Renin in treated (10 and 20 μg/mL) versus control cell cultures. Based on these results, we inferred a role for Renin at the molecular level in the response to the adverse effects of AFB(1) in male mice.

Final Report of the Safety Assessment of Cosmetic Ingredients Derived From Zea Mays (Corn)

Many cosmetic ingredients are derived from Zea mays (corn). While safety test data were not available for most ingredients, similarities in preparation and the resulting similar composition allowed extrapolation of safety data to all listed ingredients. Animal studies included acute toxicity, ocular and dermal irritation studies, and dermal sensitization studies. Clinical studies included dermal irritation and sensitization. Case reports were available for the starch as used as a donning agent in medical gloves. Studies of many other endpoints, including reproductive and developmental toxicity, use corn oil as a vehicle control with no reported adverse effects at levels used in cosmetics. While industry should continue limiting ingredient impurities such as pesticide residues before blending into a cosmetic formulation, the CIR Expert Panel determined that corn-derived ingredients are safe for use in cosmetics in the practices of use and concentration described in the assessment.

Mycotoxigenic molds in spices from Macedonian stores

Twenty-six samples of spices most frequently occurring in the stores of the Republic of Macedonia were examined for their fungal contamination and the incidence of Aspergillus and Penicillium species and their teleomorphs. It included mainly commercial packages most frequently occurring in the stores of the Republic of Macedonia. According to the relative frequency of each of the isolated species, the typical mycoflora of these samples includes A. niger, A. flavus, A. fumigatus, P. chrysogenum and Eurotium sp. Fungal counts varied from log10 < 2 CFU g-1 (DG18 at 25oC; DRBC at 25oC), for a sample of paprika, to log10 6.17 CFU g-1 (DG18 at 25oC), for a sample of bay leaf. During the experiment, A. flavus was detected in 17 samples, out of which 7 isolates were capable of producing Af-B1, and 4 isolates produced Af-B2. All isolates of A. nomius and A. parasiticus, in the experimental conditions, produced Af-B1, Af-B2, Af-G1 and Af-G2.

Assessment of aflatoxin M1 contamination in pasteurized and UHT milk marketed in central part of Iran

This study was conducted as a screening survey to determine the occurrence of aflatoxin M1 (AFM1) in 225 commercial liquid milk samples composed of pasteurized milk (116 samples) and UHT milk (109 samples) obtained from popular markets in central part of Iran. The competitive enzyme-linked immunosorbent assay method was employed to determine level of the toxin in the samples. Aflatoxin M1 was detected in 151 (67.1%) samples, consisted of 83 (71.5%) pasteurized milk samples (mean: 52.8 ng/l; range: 5.8-528.5 ng/l) and 68 (62.3%) UHT milk samples (mean: 46.4 ng/l; range: 5.6-515.9 ng/l). Considering the US FDA and Iranian national standard limits for AFM1 in milk (500 ng/l), 2 samples (1.7%) of pasteurized and 3 samples (2.7%) of UHT milk had levels above the maximum tolerance limit. However, according to European Commission limit (50 ng/l), this figure increased to 31 (26.7%) and 19 (17.4%) samples for pasteurized and UHT milk, respectively. The results indicated that the contamination of the samples with AFM1 in such a level could be a serious public health problem at the moment. This paper represents the data of the first survey on the occurrence of AFM1 in commercial liquid milk marketed in central part of Iran.

OCORRÊNCIA DE AFLATOXINAS EM MILHO DESTINADO À ALIMENTAÇÃO DE AVES NO ESTADO DA BAHIA

RESUMO O objetivo deste estudo foi determinar a ocorrência de aflatoxinas (AFs) em milho destinado à alimentação de aves no Estado da Bahia. Oitenta amostras de milho foram coletadas de duas fábricas produtoras de ração durante o período de fevereiro de 2005 a janeiro de 2006. As análises de AFs foram realizadas por meio da técnica de fluorimetria com colunas de imunoafinidade (Aflatest®, Vicam). Os resultados revelaram que oito (10%) amostras estavam contaminadas, com níveis variáveis de 1 a 5 ?g/kg. Estes resultados demonstram a boa qualidade do produto quanto à contaminação por aflatoxinas.

The potential of Origanum vulgare L. (Lamiaceae) essential oil in inhibiting the growth of some food-related Aspergillus species

Origanum vulgare L. (Lamiaceae) has been currently known for their interesting antimicrobial activity being regarded as alternative antimicrobial for use is food conservation systems. This study aimed to evaluate the effectiveness of O. vulgare essential oil in inhibiting the growth of some food-related Aspergillus species (A. flavus, A. parasiticus, A. terreus, A. ochraceus, A. fumigatus and A. niger). The essential oil revealed a strong anti-Aspergillus property providing an inhibition of all assayed mould strains. MIC values were between 80 and 20 μL/mL being found a MIC50 of 40 μL/mL. The essential oil at concentration of 80 and 40 μL/mL provided a fungicidal effect on A. flavus, A. fumigatus and A. niger noted by a total inhibition of the radial mycelial growth along 14 days of interaction. In addition, the essential oil was able to inhibit the mould spores germination when assayed at concentrations of 80 and 40 μL/mL. Our results showed the interesting anti-Aspergillus activity of O. vulgare essential oil supporting their possible use as anti-mould compound in food conservation.

Aflatoxin M1 effects on Xenopus laevis development

BACKGROUND

The principal Aflatoxin B(1) (AFB(1)) hydroxylated metabolite excreted in milk is Aflatoxin M(1) (AFM(1)) classified in group 2B by the International Agency for Research on Cancer (IARC). Human exposure to AFM(1) is due to the consumption of contaminated dairy products and partly to endogenous production through AFB(1) liver metabolism.

METHODS

Since no data are available on AFM(1) embryotoxicity, its lethal and teratogenic potential was investigated using the Frog Embryo Teratogenesis Assay-Xenopus (FETAX). Stage-8 blastulae were exposed to AFM(1) at 1, 4, 16, 64, and 256 microg/L concentrations until stage 47, free-swimming larva.

RESULTS

A slight increase of mortality and malformed larva percents was found in AFM(1)-exposed groups but these differences were not statistically significant in comparison with the controls.

CONCLUSIONS

Therefore, AFM(1) is a non-embryotoxic compound when evaluated with a FETAX model at concentrations under the conditions tested. However, AFM(1) merits further studies using mammals as experimental models to identify a possible risk during human pregnancy.

Development and integration of an immunoaffinity monolithic disk for the on-line solid-phase extraction and HPLC determination with fluorescence detection of aflatoxin B1 in aqueous solutions

The development and characterization of an anti-aflatoxin B1 (anti-AFB1) immunoaffinity monolithic disk is reported. Polyclonal anti-AFB1 was covalently immobilized in batch on an epoxy-activated monolithic Convective Interaction Media (CIM) disk (12 mm x 3 mm i.d.) by a one-step reaction via epoxy groups of the polymer surface. 0.96 mg of antibody were immobilized and the binding capacity of the CIM disk was determined by frontal analysis. The CIM disk was coupled through a switching valve to a reversed-phase column, namely Chromolith Performance RP-18e. A fully automated HPLC method with fluorescence detection for the determination of aflatoxin B1 in aqueous solution was developed. The total analysis time with the integrated system is 46 min and the retention time of AFB1 is approximately 29 min. The binding capacity of the immunoaffinity disk was evaluated in terms of linearity, precision and accuracy of the extraction procedure. The immunoaffinity support was stable after repeated runs.

Evaluation of aflatoxin B1 embryotoxicity using the frog embryo teratogenesis assay-Xenopus and bio-activation with microsome activation systems

BACKGROUND

Aflatoxins are a group of mycotoxins produced by Aspergillus, A. flavus, and A. parasiticus. Aflatoxin B1 (AFB1) should be a strong teratogen in hamsters, but its effect in rats is equivocal and extremely limited in mice. Therefore, the AFB1 embryotoxic potential in mammals remains unclear.

METHODS

Little is known about the AFB1 effects on amphibians, therefore its embryotoxic potential was evaluated using the frog embryo teratogenesis assay-Xenopus (FETAX). X. laevis blastulae were exposed to: 1) positive controls for bio-activation (4 g/L cyclophosphamide monohydrate, Cy, and 4 g/L Cy+30 mg/L MAS-rat; 4 g/L Cy+30 mg/L MAS-human); 2) positive controls for MAS (30 mg/L MAS-rat and 30 mg/L MAS-human); 3) exposed groups to AFB1 (1 mg/L AFB1); and 4) AFB1 bio-activation (1 mg/L AFB1+30 mg/L MAS-rat and 1 mg/L AFB1 +30 mg/L MAS-human).

RESULTS

In MAS-rat and human, Cy did not induce a statistically significant increase of mortality and malformed larvae percentage, but when bio-activated Cy increased the percentage of mortality. Instead, MAS-rat and human alone did not show any increase of mortality and malformed larvae percentages. When bio-activated by MAS-rat and human, AFB1 increased significantly both the mortality and malformed larvae percentages. The malformed larvae were mainly plurimalformed, i.e., affected by generalized edema, abnormal gut coiling, and microphthalmia.

CONCLUSIONS

This research shows that AFB1 alone is not embryotoxic but, when bio-activated with MAS-rat or MAS-human the percentage of mortality and malformed larvae increased significantly. These results also show that AFB1 must be bio-activated to exert its embryotoxic effects.

Teratogenic effects in rabbits of simultaneous exposure to ochratoxin A and aflatoxin B1 with special reference to microscopic effects

To elucidate the teratogenic effects, ochratoxin A (OTA) and aflatoxin B1 (AFB1) were dissolved in corn oil and administered in combination to New Zealand White rabbits during 6-18 days of gestation orally with the dose levels of OTA+AFB1, 0.05+0.05 and 0.1+0.1mg/kg body weight. To assess pathomorphological features of the anomalies, the fetal serial sections were histologically examined. There was no mortality in any of the treated groups. Body weights and body weight gains of dams in the combined treatment groups were comparable with those of controls and individual treatments. The mean crown to rump lengths in both the combination dose groups and mean fetal weights in high dose combination group were significantly decreased. In the high dose combination, there was increase in the percent of implants resorbed and significant increase in the incidence of visceral anomalies. The combination treatment resulted in various gross, skeletal and visceral anomalies such as wrist drop, scoliosis, bent metacarpals, rudimentary ribs, cardiac defects and microphthalmia. There was a dose-related increase in the percent of litters showing the histopathological changes in the fetal tissues. The incidence of histopathological changes in the tissue sections prepared from fetal liver, kidneys, brain, heart and eyes was found increased in the high dose combination group. The comparative evaluation of the results of combination versus individual treatments revealed that certain anomalies observed in the individual treatment of OTA such as knuckling of fetlock, rudimentary tail or agenesis of tail, wavy ribs, hydrocephalus and agenesis of kidney and AFB1 as enlarged eye sockets and enlarged liver were absent in the combination treatment. However, some new manifestations such as cardiac defects and scoliosis were seen. The results of the present study indicated that in combination, OTA and AFB1 have antagonistic interaction. The presence of subtle lesions histologically due to an interference with normal development suggested that microscopic examination of the fetal tissues could provide additional, useful information to a developmental toxicity study.