Resumo

URREGO NOVOA, José R  e  DIAZ, Gonzalo J. Aflatoxins and its mechanisms of toxicity in hepatic cancer. rev.fac.med. [online]. 2006, vol.54, n.2, pp.108-116. ISSN 0120-0011.

Aflatoxin B1 (AFB1) is produced by some fungus of the Aspergillus genus and it is one of the most potent known carcinogens. Action mechanisms, involves its biotransformation by the hepatic microsomal system P450 to AFB1-8, 9-epoxide. This epoxide is very reactive and electrophilic and may react with intracellular proteins, RNA or DNA. When the epoxide reacts with nucleic acids it forms an stable adduct with the N7 of the guanine residues and may induce mutations at codon 249 of the tumor suppressor gene p53. This alteration is characteristic of several carcinomas, particularly human liver carcinoma. The AFB1-8, 9-epoxide forms covalent bonds (adducts) with guanil residues in DNA; these adducts are excreted in the urine and can be used as biomarkers in risk groups for liver cancer. Given the high frequency of aflatoxins occurrence in grains for human consumption in tropical countries like Colombia, it is necessary to conduct studies to determine both the presence of aflatoxins in food and biomarkers in urine. This information could lead to the implementation of regulations intended to define public health measures for the control of aflatoxins exposure.

Palavras-chave : aflatoxins; hepatic; cancer; carcinoma; tumor markers; biological; molecular mechanisms of action; toxicology; mutagens.

        · resumo em Espanhol     · texto em Espanhol     · Espanhol ( pdf )