Aflatoxins are naturally occuring mycotoxins produced by various species of the mold Aspergillus, which can be found in legumes, corn, soybeans, rice, milk, and cheese. They are highly carcinogenic substances that are metabolized by the liver to a reactive epoxide intermediate, which produces adducts that modify DNA. Aflatoxin B1 induces transversion of G to T at codon 249 of the p53 tumor suppressor gene. This transversion is common in hepatocellular carcinoma patients living in regions with high levels of aflatoxin contamination. Aflatoxin B2 is the dihydro derivative of aflatoxin B1, a naturally occuring mycotoxin and food contaminant that is a likely pathogen that causes hepatocellular carcinoma.
