Aromatic amines dietary

A second example of sulfate bioactivation derives from the observed carcinogenicity of aromatic amineS/ such as those derived from coal tar (44). The polycyclic aromatic amines are N-hydroxylated by CYPs and then sulfated to form unstable N-O-sulfates that decompose and produce reactive nitrenium ion intermediates/ which form DNA and protein adducts. One environmental/genetic hypothesis of colon cancer etiology involves the interaction between dietary aromatic amines and the polymorphic expression of the appropriate STs for their activation to procarcinogenic reactive intermediates (44/ 45). 

A number of polycyclic aromatic amines are carcinogens in animals. 2-Acetylaminfluorene is a teratogen, mutagen, and carcinogen. It is tumori-genic in rats at 2420 mg (TD, oral). Dietary exposure to 2-acetylaminofluorene in rats led to tumors of the liver, bladder, renal pelvis, ear canal, colon, lung, pancreas, and testis. Tumors of the liver, bladder, and kidney have been observed in mice exposed to dietary 2-acetylaminofluorene. Bladder and liver tumors have been observed in other laboratory animals exposed to 2-acetylaminofluorene. 

Lovenberg, 1974). Besides, when putrescine and cadaverine are cooked they may be converted into pyrrolidine and piperidine, respectively (Yamamoto et al., 1982). These secondary amines, as well as spermidine and spermine, may undergo nitrosation forming the extremely carcinogenic compound nitrosamine. The aromatic amines P-phenylethylamine, tyramine, isopentylamine, and 3-(2-aminoethyl) indole (tryptamine), are responsible for dietary disturbances, including migraines and hypertension (Stratton et al., 1991 Anderson et al., 1993). In wine, these compounds are present as odorless salts, but at the pH in the mouth they may have repulsive smells. 

Aromatic amines (AAs) and heterocyclic aromatic amines (HAAs) are ubiquitous environmental and dietary contaminants, many of which are carcinogens. Compounds of both classes contain an exocydic amino group, which is a prerequisite for their genotoxicity (Figure 7.1). In this chapter, the sources of exposure, mechanisms of metabolic activation, formation and detection of DNA adducts, and biological effects of AA-DNA and HAA-DNA adducts are highlighted. 

Rohrmann S, Becker N. Development of a short questionnaire to assess the dietary intake of heterocyclic aromatic amines. Public Health Nutr 2002 5 699-705. 

Some dietary practices are thought to contribute to cancer development (Table 21.7). For example, high-temperature cooking prodnces carcinogens such as heterocyclic amines and polycychc aromatic hydrocarbons, and storing food can allow microbial carcinogens, snch as aflatoxin, to be prodnced (see Figure 21.27). 

This chapter is divided into seven main sections. The first of these sections is focused on technological contaminants, namely heterocyclic amines, acrylamide, furan, chloropropanok and their fatty acid esters, polycycKc aromatic hydrocarbons, monocyclic aromatic hydrocarbons, nitroso compounds, and ethyl carbamate. Other sections deal with microbial toxins (mycotoxins and bacterial toxins), persistent organohalogen contaminants (such as polychlorinated biphenyls, dibenzodioxins and dibenzofurans), chlorinated ahphatic hydrocarbons, pesticides (persistent chlorinated hydrocarbons and modem pesticides), veterinary medicines and contaminants from packaging materials. Presented for each of these contaminants are structures, properties, occurrence and the main sources of dietary intake, mechanisms of formation, possibilities of food contamination, prevention and mitigation and health and toxicological evaluations. 

The amines under consideration are all aromatic substances, containing benzene or indole rings and are synthesized in vivo from the two aromatic L-amino acids, L-tyrosine and L tryptophan. The latter is an essential amino acid in so far as man cannot synthesize it and thus depends on dietary sources. Tyrosine is not essential, being formed by p-hydroxylation of the benzene ring of phenylalanine. Tyrosine and tryptophan have many routes of metabolism, the pathways leading to amine... 

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