We have examined the time course and patterns of covalent aflatoxin B1:DNA adducts produced within the ribosomal RNA gene sequences isolated from the liver nuclear DNA of aflatoxin B1-treated animals. Liver nuclear DNA was initially enriched in ribosomal DNA by cesium salt density centrifugation, and incubated under alkaline conditions to stabilize bound aflatoxin B1-DNA moieties. Alkali-treate...

Aflatoxin contamination of maize grain threatens human food and animal feed safety. Breeding for reduced grain aflatoxin accumulation is one of the best strategies presently available to lower grain aflatoxin accumulation. Previously identified sources of germplasm with reduced grain aflatoxin accumulation are excessively tall and late maturing. The objective of this research was to screen germ...

Effective preharvest strategies to eliminate aflatoxin accumulation in crops are not presently available. The molecular biology of aflatoxin biosynthesis has been extensively studied, and genetic and molecular tools such as reporter gene systems for the measurement of fungal growth have been developed. A reporter construct containing the Aspergillus flavus beta-tubulin gene promoter fused to Es...

Zinc concentrations strongly influence aflatoxin accumulation in laboratory media and in food and feed crops. The presence of zinc stimulates aflatoxin production, and the absence of zinc impedes toxin production. Initial studies that suggested a link between zinc and aflatoxin biosynthesis were presented in the 1970s. In the present study, we utilized two zinc chelators, N,N,N',N'-tetrakis (2-...

One strategy to reduce aflatoxin contamination of maize and cottonseed is to introduce spores of non-aflatoxigenic strains as competitors. Using isogenic mutants we show that, upon 5 or 20 min exposure to 302 nm (UVB) light, the viability of conidia of Aspergillus flavus and Aspergillus parasiticus mutants lacking the ability to accumulate any aflatoxin precursor metabolite is reduced five-fold...

OBJECTIVES Investigations were carried out to determine aflatoxin levels in household maize in Makueni District and to correlate aflatoxin levels to maize drying and storage practices. Also, aflatoxin exposure in villages that reported aflatoxicosis cases in 2005 was compared with that in villages that did not report cases to assess whether aflatoxin exposure levels could be used to identify hi...

BACKGROUND Weanimix is an important food for children in Ghana. Mothers are trained to prepare homemade weanimix from beans, groundnuts and maize for their infants. Groundnuts and maize are prone to aflatoxin contamination while fumonisin contaminates maize. Aflatoxin, is produced by the Asperguillus fungi while fumonisin, is produced by Fusarium fungi. These mycotoxins occur in tropical areas ...

The effects of various inducers on the activities of drug-metabolizing enzymes including aflatoxin B1 activation were studied in Syrian golden hamsters. Activity for aflatoxin B1 was determined by aflatoxin B1-DNA adducts formation. The treatments of hamsters with 3-methylcholanthrene, alpha-naphthoflavone and benzo(a)pyrene elevated markedly the activity for aflatoxin B1 by 2460, 1380 and 450%...

BACKGROUND Over 4 billion people worldwide are exposed to dietary aflatoxins, which cause liver cancer (hepatocellular carcinoma, HCC) in humans. However, the population attributable risk (PAR) of aflatoxin-related HCC remains unclear. METHODS In our systematic review and meta-analysis of epidemiological studies, summary odds ratios (ORs) of aflatoxin-related HCC with 95% confidence intervals...

Aflatoxins are toxic secondary metabolites produced by a 70-kb cluster of genes in Aspergillus flavus. The cluster genes are coordinately regulated and reside as a single copy within the genome. Diploids between a wild-type strain and a mutant (649) lacking the aflatoxin gene cluster fail to produce aflatoxin or transcripts of the aflatoxin pathway genes. This dominant phenotype is rescued in d...