Aflatoxin Toxicity

Aflatoxins are metabolites produced by toxigenic strains of molds, mainly Aspergillus flavus and A. parasiticus, which grow in soil, hay, decaying vegetation, and grains. Aflatoxin toxicity occurs due to acute or chronic exposure to aflatoxin. The term "aflatoxin" is derived from the name of Aspergillus flavus. It was named around 1960 after its discovery as the source of a disease in turkey called "turkey X disease" in turkeys fed rations of peanuts and cottonseed. Aflatoxins form one of the major groupings of mycotoxins. Aflatoxin is produced by fungal action during production, harvest, storage, and processing of food and feed. The U.S. Food and Drug Administration (FDA) considers it to be an unavoidable contaminant of foods. Aflatoxin toxicity has been well established in both humans and animals. Aflatoxin exposure can cause nausea, vomiting, abdominal pain, convulsions acutely, and its chronic exposure can also lead to various complications like hepatotoxicity, immunotoxicity, and teratogenicity. Aflatoxin is one of the major causes of hepatocellular carcinoma in developing countries. There are different types of aflatoxin. Aflatoxin B1(AFB1) and aflatoxin B2(AFB2) are produced by both A. flavus and A. parasiticus, and AFB1 is believed to be the most potent among all aflatoxins. Aflatoxin M1(AFM1) is found in the fermentation broth of A parasiticus, but it and aflatoxin M2 are also developed when an infected liver metabolizes AFB1 and AFB2. AFM1 can be transmitted by milk. AFB1 and AFM1 have been classified as group 1 and group 2B human carcinogens by the International Agency for Research on Cancer (IARC).