Aflatoxins and Aflatoxicosis in Human and Animals

Moldy feed toxicosis was recognized as a serious livestock problem in the 1950's but it was only in 1960 during the investigations in the United Kingdom of moldy feed toxicosis which was called Turkey “x” disease, that A. flavus and A. parasiticus were identified as the organisms responsible for the elaboration of the toxin in the feed. The earliest symptoms of the disease are lithargy and muscular weakness followed by death. The term aflatoxin now refers to group of bisfuranocoumarin metabolites isolated from strains of A. flavus group of fungi. The toxic material derived from the fungus A. flavus was given the name "aflatoxin" in 1962 (Sargeant et al., 1963). Aflatoxins fluoresce strongly in ultra violet light. The major members are designated as B1, B2, G1 and G2. B1 and B2 fluoresces blue, while Gl and G2 fluoresces green. In some animal species in dairy cattle, aflatoxin B1 and B2 are partially metabolized to the hydroxylated derivates namely M1 and M2, respectively. Aflatoxin P1 is a urinary metabolite of Bl in monkeys. All aflatoxins absorb UV light in the range of 362-363nm, a characteristic used in preliminary identification. The growth of toxigenic molds and elaboration of the toxin occurs if moisture conditions are ideal following harvest and storage. Although initially aflatoxin was detected in the peanut meal it is now known that a variety of cereals, and other plant products are susceptible to fungal invasion and mycotoxin production. The occurrence of aflatoxins in agricultural commodities depends on such factors as region, season and the conditions under which a particular crop is grown, harvested or stored. Because of the wide spread nature of fungi producing aflatoxins in food materials, international agencies have now permitted the presence of 20 ppb of aflatoxin in food materials as the maximum permissible level. In 1993 aflatoxin by the World Health Organization (WHO) for cancer research institutions designated as a Class 1 carcinogen, is a highly poisonous toxic substances. Aflatoxin is harmful to human and animal liver tissue