Mycotoxin carcinogen

Among several classes of compounds belonging to the group of mycotoxins, carcinogenic properties have been demonstrated only for three of them. These are aflatoxins and sterigmatocystin, inducing liver cancers, and ochratoxin A, implicated in the development of kidney cancers in experimental animals (Wakabayashi etal., 1991) ... 

UK Ministry of Agriculture Fisheries and Food and Flealth and Safety Executive, Annual Report of the Working Party on Pesticide Residues in Food (1997), MAFF Publications, London, 1997. lARC, Monographs on the Evabiation of the Carcinogenic Risk of Chemicals to Hnmans Volume 56 Some Naturally Occurring Substances Food Items and Constituents, Heterocyclic Aromatic Amines and Mycotoxins, WFIO, Geneva, 1979, p. 397. 

Assessment of whether a chemical has the potential to cause adverse effects in humans arises usually from direct observation of an effect in animals or humans, such as the acute poisoning episodes that have occurred when potatoes contain high levels of glycoalkaloids. Epidemiological studies have also been used to infer a possible relationship between intake of a particular type of food, or constituent of that food, and the potential to cause an adverse effect. Such observations led to the characterisation of the aflatoxins as human carcinogens. However, natural toxic substances that occur in plant foods have often been identified through observations in animals, particularly farm animals. It was observations of adverse effects in farm animals that led to the further characterisation of the phytoestrogens and the mycotoxins. In other instances, the concern arises from the chemical similarity to other known toxins. 

International Agency for Research on Cancer (lARC) (1993). Toxins derived from Fusarium moniliforme Fumonisins Bi and Bz and Fusarin C. In "lARC Monographs on the Evaluation of the Carcinogenic Risks to Humans Some Naturally Occurring Substances Food Items and Constituents, Heterocyclic Aromaotic Amines and Mycotoxins," vol. 56, pp. 445 66. International Agency for Research on Cancer, Lyon, France. 

Aflatoxins Contaminant (mycotoxin) Produced by Aspergillus flavus, especially grains, corn, and peanuts carcinogenic and hepatotoxic... 

Enzyme-linked immunosorbent assay (ELISA) is a very useful technique for the specific and sensitive assay of certain compounds, in which suitable antibodies, monoclonal or polyclonal, to the compounds are available. The technique has found particular application m the monitoring of environmental contaminants and toxins, either studying the primarily contaminated materials, e.g., foodstuffs, or body fluids of potentially exposed humans. The technique has been increasingly applied to monitoring the carcinogenic mycotoxins, the aflatoxins. 

M Castegnaro, J Barek, JM Fremy, M Lafontaine, M Miraglia, EB Sansone, GM Telling. IARC Laboratory Decontamination and Destruction of Carcinogens in Laboratory Wastes Some Mycotoxins. Scientific Publication N. 113, 1991. 

IARC. Some naturally occurring substances food items and constituents, heterocyclic aromatic amines and mycotoxins. Monographs on the evaluation of carcinogenic risks to humans. 56 489-521, 1993. 

The mycotoxin ochratoxin A (AAA) (7), which is a possible human carcinogen, continues to receive extensive attention due to its presence in a myriad of foods and beverages (1520, 1521) and its well-established toxicity (teratogenicity, mutagenicity, immunotoxicity, genotoxicity, and carcinogenicity) (1522-1524). Major sources of ochratoxin A are grapes, must, and wine (1525-1533), cereals (1534), beer (1535,1536), dried fruit (1537), roasted coffee (1538), and cocoa products and chocolate (1539). 

The time-scale over which contaminants can exert an adverse effect is also of importance. For carcinogens such as PAHs and mycotoxins, it is the long-term cumulative dose that is most important. Conversely for organophosphorus pesticide residues, one meal might be sufficient to cause some inhibition of the cholinesterase enzyme. 

Because of their diversity of chemical structures and differing physical properties, mycotoxins exhibit a wide array of biological effects on mammalian systems and individual mycotoxins can be genotoxic, mutagenic, carcinogenic, embryotoxic, teratogenic or oestrogenic (Smith and Henderson, 1991). Some... 

The adverse health effects most readily associated with mycotoxin consumption are either acute or subchronic. Chronic effects, such as carcinogenicity, have been more difficult to directly relate to mycotoxin consumption. This is in spite of the fact that various data indicate that at least 45 mycotoxins are known to be either mutagenic or carcinogenic (1). The following mycotoxins may pose an adverse human health risk in respect to carcinogenicity aflatoxin, cyclochlorotine, griseofulvin, luteoskyrin, ochratoxin, patulin, penicillic acid, sterigmatocystin, T-2 toxin, and zearalenone. 

In summary, it has been shown that dietary protein levels can influence the metabolism of the mycotoxin AFBi. Altered metabolism is, in part, responsible for the protective role of low protein diets with respect to carcinogenicity and possibly with its increased toxicity in protein deficient rats. Dietary protein levels can also influence the promotional phase of carcinogenesis. Further research is required to determine the mechanisms associated with the influence of dietary protein on both the initiation and promotional phases of carcinogenesis. 

The majority of toxicants in foods are contaminants, (e.g., microbial toxins, pesticide residues, leachable chemicals from packaging materials, food coatings, traces of heavy metals). However, the major issue in food safety is the contamination of food by mycotoxins in items such as milk and milk products, meat and meat products, and peanuts (groundnuts). Aflatoxin is highly toxic and lethal, and its carcinogenic potential is well established, even at doses as low as 0.05. ig. Mycotoxins also infect food products like rice, pulses, tapioca, and betelnuts. (Table 10-2). 

IARC (2002) Some traditional herbal medicines, some mycotoxins, naphthalene and styrene. Lyon, International Agency for Research on Cancer, pp 171-274 (IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Vol. 82). 

IARC (2002). "Some Traditional Herbal Medicines, Some Mycotoxins, Naphthalene and Styrene," IARC Working Group on the Evaluation of Carcinogenic Risk to Humans, IARC Press, Lyon. 

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