Aflatoxins: Furano-furano-benzopyrans that are produced by ASPERGILLUS from STERIGMATOCYSTIN. They are structurally related to COUMARINS and easily oxidized to an epoxide form to become ALKYLATING AGENTS. Members of the group include AFLATOXIN B1; aflatoxin B2, aflatoxin G1, aflatoxin G2; AFLATOXIN M1; and aflatoxin M2.Aflatoxin B1: A potent hepatotoxic and hepatocarcinogenic mycotoxin produced by the Aspergillus flavus group of fungi. It is also mutagenic, teratogenic, and causes immunosuppression in animals. It is found as a contaminant in peanuts, cottonseed meal, corn, and other grains. The mycotoxin requires epoxidation to aflatoxin B1 2,3-oxide for activation. Microsomal monooxygenases biotransform the toxin to the less toxic metabolites aflatoxin M1 and Q1.Aflatoxin M1: A 4-hydroxylated metabolite of AFLATOXIN B1, one of the MYCOTOXINS from ASPERGILLUS tainted food. It is associated with LIVER damage and cancer resulting from its P450 activation to the epoxide which alkylates DNA. Toxicity depends on the balance of liver enzymes that activate it (CYTOCHROME P-450) and others that detoxify it (GLUTATHIONE S TRANSFERASE) (Pharmac Ther 50.443 1991). Primates & rat are sensitive while mouse and hamster are tolerant (Canc Res 29.236 1969).Aspergillus flavus: A species of imperfect fungi which grows on peanuts and other plants and produces the carcinogenic substance aflatoxin. It is also used in the production of the antibiotic flavicin.Aspergillus: A genus of mitosporic fungi containing about 100 species and eleven different teleomorphs in the family Trichocomaceae.Sterigmatocystin: A carcinogenic mycotoxin produced in high yields by strains of the common molds, Aspergillus versicolor, A. nidulans, and an unidentified species of Bipolaris. It causes necrosis of the liver and kidney and has an inhibitory effect on orotic acid incorporation into nuclear RNA.Food Contamination: The presence in food of harmful, unpalatable, or otherwise objectionable foreign substances, e.g. chemicals, microorganisms or diluents, before, during, or after processing or storage.Poisons: Substances which, when ingested, inhaled, or absorbed, or when applied to, injected into, or developed within the body in relatively small amounts may, by their chemical action, cause damage to structure or disturbance of function. (From Dorland, 27th ed)Anthraquinones: Compounds based on ANTHRACENES which contain two KETONES in any position. Substitutions can be in any position except on the ketone groups.Arachis hypogaea: A plant species of the family FABACEAE that yields edible seeds, the familiar peanuts, which contain protein, oil and lectins.Ethoxyquin: Antioxidant; also a post-harvest dip to prevent scald on apples and pears.Mycotoxicosis: Poisoning caused by the ingestion of mycotoxins (toxins of fungal origin).Dichlorvos: An organophosphorus insecticide that inhibits ACETYLCHOLINESTERASE.Ochratoxins: Isocoumarins found in ASPERGILLUS OCHRACEUS and other FUNGI. Ochratoxin contaminated FOOD has been responsible for cases of FOODBORNE DISEASES.Mycotoxins: Toxic compounds produced by FUNGI.Carcinogens: Substances that increase the risk of NEOPLASMS in humans or animals. Both genotoxic chemicals, which affect DNA directly, and nongenotoxic chemicals, which induce neoplasms by other mechanism, are included.Condiments: Aromatic substances added to food before or after cooking to enhance its flavor. These are usually of vegetable origin.Chromatography, Thin Layer: Chromatography on thin layers of adsorbents rather than in columns. The adsorbent can be alumina, silica gel, silicates, charcoals, or cellulose. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Zea mays: A plant species of the family POACEAE. It is a tall grass grown for its EDIBLE GRAIN, corn, used as food and animal FODDER.Zearalenone: (S-(E))-3,4,5,6,8,10-Hexahydro-14,16-dihydroxy-3-methyl-1H-2-benzoxacyclotetradecin-1,7(8H)-dione. One of a group of compounds known under the general designation of resorcylic acid lactones. Cis, trans, dextro and levo forms have been isolated from the fungus Gibberella zeae (formerly Fusarium graminearum). They have estrogenic activity, cause toxicity in livestock as feed contaminant, and have been used as anabolic or estrogen substitutes.Food Microbiology: The presence of bacteria, viruses, and fungi in food and food products. This term is not restricted to pathogenic organisms: the presence of various non-pathogenic bacteria and fungi in cheeses and wines, for example, is included in this concept.Biotransformation: The chemical alteration of an exogenous substance by or in a biological system. The alteration may inactivate the compound or it may result in the production of an active metabolite of an inactive parent compound. The alterations may be divided into METABOLIC DETOXICATION, PHASE I and METABOLIC DETOXICATION, PHASE II.Food Analysis: Measurement and evaluation of the components of substances to be taken as FOOD.Liver Neoplasms: Tumors or cancer of the LIVER.Mutagens: Chemical agents that increase the rate of genetic mutation by interfering with the function of nucleic acids. A clastogen is a specific mutagen that causes breaks in chromosomes.DNA Adducts: The products of chemical reactions that result in the addition of extraneous chemical groups to DNA.Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.Encyclopedias as Topic: Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)Liver Failure, Acute: A form of rapid-onset LIVER FAILURE, also known as fulminant hepatic failure, caused by severe liver injury or massive loss of HEPATOCYTES. It is characterized by sudden development of liver dysfunction and JAUNDICE. Acute liver failure may progress to exhibit cerebral dysfunction even HEPATIC COMA depending on the etiology that includes hepatic ISCHEMIA, drug toxicity, malignant infiltration, and viral hepatitis such as post-transfusion HEPATITIS B and HEPATITIS C.Nafronyl: A drug used in the management of peripheral and cerebral vascular disorders. It is claimed to enhance cellular oxidative capacity and to be a spasmolytic. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1310) It may also be an antagonist at 5HT-2 serotonin receptors.Foreign Professional Personnel: Persons who have acquired academic or specialized training in countries other than that in which they are working. The concept excludes physicians for which FOREIGN MEDICAL GRADUATES is the likely heading.Ecotoxicology: The study of ENVIRONMENTAL POLLUTION and the toxic effects of ENVIRONMENTAL POLLUTANTS on the ECOSYSTEM. The term was coined by Truhaut in 1969.Toxicology: The science concerned with the detection, chemical composition, and biological action of toxic substances or poisons and the treatment and prevention of toxic manifestations.Environmental Health: The science of controlling or modifying those conditions, influences, or forces surrounding man which relate to promoting, establishing, and maintaining health.Environmental Exposure: The exposure to potentially harmful chemical, physical, or biological agents in the environment or to environmental factors that may include ionizing radiation, pathogenic organisms, or toxic chemicals.Dictionaries, MedicalDictionaries as Topic: Lists of words, usually in alphabetical order, giving information about form, pronunciation, etymology, grammar, and meaning.Helianthus: A genus herbs of the Asteraceae family. The SEEDS yield oil and are used as food and animal feed; the roots of Helianthus tuberosus (Jerusalem artichoke) are edible.Seeds: The encapsulated embryos of flowering plants. They are used as is or for animal feed because of the high content of concentrated nutrients like starches, proteins, and fats. Rapeseed, cottonseed, and sunflower seed are also produced for the oils (fats) they yield.MichiganStearates: Salts and esters of the 18-carbon saturated, monocarboxylic acid--stearic acid.Research: Critical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws. (Webster, 3d ed)Tropical Medicine: The branch of medicine concerned with diseases, mainly of parasitic origin, common in tropical and subtropical regions.Periodicals as Topic: A publication issued at stated, more or less regular, intervals.Breeding: The production of offspring by selective mating or HYBRIDIZATION, GENETIC in animals or plants.Patient Care Team: Care of patients by a multidisciplinary team usually organized under the leadership of a physician; each member of the team has specific responsibilities and the whole team contributes to the care of the patient.Williams Syndrome: A disorder caused by hemizygous microdeletion of about 28 genes on chromosome 7q11.23, including the ELASTIN gene. Clinical manifestations include SUPRAVALVULAR AORTIC STENOSIS; MENTAL RETARDATION; elfin facies; impaired visuospatial constructive abilities; and transient HYPERCALCEMIA in infancy. The condition affects both sexes, with onset at birth or in early infancy.Dictionaries, ChemicalMyristica fragrans: A plant species in the MYRISTICACEAE family. The seed is used as a spice and used for antimicrobial and psychoactive effects. Myristicin, SAFROLE, and methyleugenol are key components.Penicillium: A mitosporic Trichocomaceae fungal genus that develops fruiting organs resembling a broom. When identified, teleomorphs include EUPENICILLIUM and TALAROMYCES. Several species (but especially PENICILLIUM CHRYSOGENUM) are sources of the antibiotic penicillin.Cottonseed Oil: Oil obtained from the seeds of Gossypium herbaceum L., the cotton plant. It is used in dietary products such as oleomargarine and many cooking oils. Cottonseed oil is commonly used in soaps and cosmetics.

Mycotoxin determinations on animal feedstuffs and tissues in Western Canada. (1/749)

Results of examination of specimens of plant or animal origin for various mycotoxins are presented. Analyses for aflatoxins and ochratoxins were most frequently requested, usually on the basis of visible mouldiness. Aflatoxin B1 was found in one of 100 specimens at a level of 50 ppb in a sample of alfalfa brome hay. Ochratoxin A was detected in seven of 95 specimens comprising six samples of wheat at levels between 30 and 6000 ppb and one sample of hay at a level of 30 ppb. An overall detection rate of 4.2% involving significant levels of potent mycotoxins suggests that acute or chronic mycotoxicoses may occur in farm livestock or poultry more frequently than presently diagnosied.  (+info)

Effect of sex difference on the in vitro and in vivo metabolism of aflatoxin B1 by the rat. (2/749)

Hepatic microsome-catalyzed metabolism of aflatoxin B1 (AFB1) to aflatoxin M1 and aflatoxin Q1 and the "metabolic activation" of AFB1 to DNA-alylating metabolite(s) were studied in normal male and female Sprague-Dawley rats, in gonadectomized animals, and in castrated males and normal females treated with testosterone. Microsomes from male animals formed 2 to 5 times more aflatoxin M1, aflatoxin Q1, and DNA-alkylating metabolite(s) than those from females. Castration reduced the metabolism of AFB1 by the microsomes from males by about 50%, whereas ovariectomy had no significant effect on AFB1 metabolism by the microsomes from females. Testosterone treatment (4 mg/rat, 3 times/week for about 6 weeks) of castrated immature males and immature females enhanced the metabolism of AFB1 by their microsomes. A sex difference in the metabolism of AFB1 by liver microsomes was also seen in other strains of rats tested: Wistar, Long-Evans, and Fischer. The activity of kidney microsomes for metabolic activation was 1 to 4% that of the liver activity and was generally lower in microsomes from male rats as compared to those from female rats of Sprague-Dawley, Wistar, and Long-Evans strains. The in vitro results obtained with hepatic microsomes correlated well with the in vivo metabolism of AFB1, in that more AFB1 became bound in vivo to hepatic DNA isolated from male rats and from a female rat treated with testosterone than that isolated from control female rats. These data suggest that the differences in hepatic AFB1 metabolism may be the underlying cause of the sex difference in toxicity and carcinogenicity of AFB1 observed in rats.  (+info)

Effect of zinc on adenine nucleotide pools in relation to aflatoxin biosynthesis in Aspergillus parasiticus. (3/749)

The adenylic acid systems of Aspergillus parasiticus were studied in zinc-replete and zinc-deficient media. The adenosine 5'-triphosphate levels of the fungus were high during exponential phase and low during stationary phase in zinc-replete cultures. On the other hand, the levels of adenosine 5'-diphosphate and adenosine 5'-monophosphate were low during exponential phase of growth and high during stationary phase. The adenosine 5'-triphosphate levels during exponential phase may indicate higher primary metabolic activity of the fungus. On the other hand, high adenosine 5'-monophosphate levels during stationary phase may inhibit lipid formation and may enhance aflatoxin levels. The inorganic phosphorus content was low in a zinc-replete medium throughout the growth period, thereby favoring aflatoxin biosynthesis. The energy charge during the exponential phase was high but low during the stationary phase. In general the energy charge values were lower because of high adenosine 5'-monophosphate content.  (+info)

Characterization of the promoter for the gene encoding the aflatoxin biosynthetic pathway regulatory protein AFLR. (4/749)

Most genes in the aflatoxin biosynthetic pathway in Aspergillus parasiticus are regulated by the binuclear zinc cluster DNA-binding protein AFLR. The aflR promoter was analyzed in beta-glucuronidase reporter assays to elucidate some of the elements involved in the gene's transcription control. Truncation at 118 bp upstream of the translational start site increased promoter activity 5-fold, while truncation at -100 reduced activity about 20-fold. These findings indicate the presence of an important positive regulatory element between -100 and -118 and a negative regulatory region further upstream. Electrophoretic mobility shift assays on nuclear extracts from A. parasiticus induced for aflatoxin expression suggest that AFLR and another, possibly more abundant, protein bind to the -100/-118 region. Another protein binds to a sequence at position -159 to -164 that matches the consensus binding site for the transcription factor involved in pH-dependent gene regulation, PACC.  (+info)

HGF-mediated apoptosis via p53/bax-independent pathway activating JNK1. (5/749)

Current studies have indicated both positive and negative roles for the hepatocyte growth factor (HGF)/c-met receptor signaling system in tumor development. Recently, we have shown that HGF has the capacity to induce both growth inhibition and programmed cell death in aflatoxin-transformed (AFLB8) rat liver epithelial cells. Using the same cell line, we have now investigated a potential mechanism for HGF-induced apoptosis. Immunoblot analysis of bcl-2 gene family member (bax, bcl-2, bclX-s/l) expression showed no correlation with HGF treatment, suggesting that HGF-mediated apoptosis is bax independent. Following HGF treatment retinoblastoma protein (pRB) was present in the hypophosphorylated state. HGF treatment increased cyclin A, cyclin G1 and nuclear transcriptional factor (NFkappaB) protein expression. However, electrophoretic mobility shift analysis showed that NFkappaB activity decreased with HGF treatment. Under these apoptotic conditions, c-Jun N-terminal kinase (JNK1) and extracellular signal-regulated kinase (ERK2) were activated with lower level activation of ERK2, while no involvement of phosphatidylinositol-3 kinase was observed. Epidermal growth factor (EGF) was not protective, and actually induced cells to undergo apoptosis to a level similar to that of HGF alone or EGF/HGF in combination. These results suggest the possibility of cross-talk between HGF/c-met and EGF/EGFR signaling pathways, and the involvement of JNK1 induction in HGF-mediated apoptotic cell death.  (+info)

Divergence of West African and North American communities of Aspergillus section Flavi. (6/749)

West African Aspergillus flavus S isolates differed from North American isolates. Both produced aflatoxin B1. However, 40 and 100% of West African isolates also produced aflatoxin G1 in NH4 medium and urea medium, respectively. No North American S strain isolate produced aflatoxin G1. This geographical and physiological divergence may influence aflatoxin management.  (+info)

Interactions of saprophytic yeasts with a nor mutant of Aspergillus flavus. (7/749)

The nor mutant of Aspergillus flavus has a defective norsolorinic acid reductase, and thus the aflatoxin biosynthetic pathway is blocked, resulting in the accumulation of norsolorinic acid, a bright red-orange pigment. We developed a visual agar plate assay to monitor yeast strains for their ability to inhibit aflatoxin production by visually scoring the accumulation of this pigment of the nor mutant. We identified yeast strains that reduced the red-orange pigment accumulation in the nor mutant. These yeasts also reduced aflatoxin accumulation by a toxigenic strain of A. flavus. These yeasts may be useful for reducing aflatoxin contamination of food commodities.  (+info)

Enzymatic formation of G-group aflatoxins and biosynthetic relationship between G- and B-group aflatoxins. (8/749)

We detected biosynthetic activity for aflatoxins G(1) and G(2) in cell extracts of Aspergillus parasiticus NIAH-26. We found that in the presence of NADPH, aflatoxins G(1) and G(2) were produced from O-methylsterigmatocystin and dihydro-O-methylsterigmatocystin, respectively. No G-group aflatoxins were produced from aflatoxin B(1), aflatoxin B(2), 5-methoxysterigmatocystin, dimethoxysterigmatocystin, or sterigmatin, confirming that B-group aflatoxins are not the precursors of G-group aflatoxins and that G- and B-group aflatoxins are independently produced from the same substrates (O-methylsterigmatocystin and dihydro-O-methylsterigmatocystin). In competition experiments in which the cell-free system was used, formation of aflatoxin G(2) from dihydro-O-methylsterigmatocystin was suppressed when O-methylsterigmatocystin was added to the reaction mixture, whereas aflatoxin G(1) was newly formed. This result indicates that the same enzymes can catalyze the formation of aflatoxins G(1) and G(2). Inhibition of G-group aflatoxin formation by methyrapone, SKF-525A, or imidazole indicated that a cytochrome P-450 monooxygenase may be involved in the formation of G-group aflatoxins. Both the microsome fraction and a cytosol protein with a native mass of 220 kDa were necessary for the formation of G-group aflatoxins. Due to instability of the microsome fraction, G-group aflatoxin formation was less stable than B-group aflatoxin formation. The ordA gene product, which may catalyze the formation of B-group aflatoxins, also may be required for G-group aflatoxin biosynthesis. We concluded that at least three reactions, catalyzed by the ordA gene product, an unstable microsome enzyme, and a 220-kDa cytosol protein, are involved in the enzymatic formation of G-group aflatoxins from either O-methylsterigmatocystin or dihydro-O-methylsterigmatocystin.  (+info)

  • The experiment was conducted at Nong Lam University in Ho Chi Minh City, Vietnam in order to test the effects of aflatoxin B 1 and the counteracting properties of the binder Mycofix® Secure. (thefishsite.com)
  • aflatoxins are produced on peanuts, soybeans, corn and other cereals in the field or during storage when moisture content and temperatures are sufficiently high for mold growth. (gotmold.ca)
  • The article , "Injectable trace minerals (selenium, copper, zinc, and manganese) alleviates inflammation and oxidative stress during an aflatoxin challenge in lactating multiparous Holstein cows," is published in the Journal of Dairy Science [DOI: 10.3168/jds.2018- (goldeaglecoop.com)
  • Adult humans have a high tolerance for aflatoxin exposure and rarely succumb to acute aflatoxicosis, but children are particularly affected, and their exposure can lead to stunted growth and delayed development, in addition to all the symptoms mentioned below. (wikipedia.org)
  • Despite the potential health risk posed to animals and humans, many people in developing countries are oblivious of the ability of aflatoxins to cause cancer and other debilitating diseases. (academicjournals.org)
  • Toxigenic molds pose the most serious health risk to both humans and animals because they have aflatoxins . (gotmold.ca)
  • For example, contaminated poultry feed is suspected in the findings of high percentages of samples of aflatoxin-contaminated chicken meat and eggs in Pakistan. (wikipedia.org)
  • At least 14 different aflatoxins are produced in nature. (wikipedia.org)
  • As we had hypothesized, supplying cows with trace minerals via injection, independent of minerals ingested in the feed, resulted in an improved immune response and reduced oxidative stress when cows were challenged with aflatoxin," Pate says. (goldeaglecoop.com)
  • While regulated in the United States, many underdeveloped countries do not have the resources to monitor aflatoxin accumulation in maize and, thus, developing low aflatoxin accumulation commercial maize lines would be of great benefit. (umsystem.edu)