RESUMO
In this study, hepatic biopsies from autopsy cases in São Paulo, Brazil, showing hepatocellular carcinoma (HCC, n = 8), cirrhosis associated with viral hepatitis (VC, n = 20), cirrhosis associated with alcoholism (AC, n = 20), and normal livers (NL or controls, n = 10) were subjected to determination of aflatoxin B1 (AFB1) and its main metabolites, and of markers of hepatic carcinogenesis Only non-metabolized AFB1 was detected in 13 samples (27.1%, N = 48) of liver disorders (HCC, VC and AC), at levels between 10.0 and 418.0 pg/g (mean: 76.6 ± 107.7 pg/g). Immuno-labeling of p53, cyclin D1, p21, ß-catenin, and Prohibitin (PB) increased mainly in HCC patients, in relation to the controls. AFB1+ samples of HCC presented higher expressions of p53, cyclin D1, p21, and ß-catenin compared with AFB1-livers. In contrast, p27, p16, and Rb immuno-labeling decreased in HCC, VC, and AC samples, compared with NL, with lowest values in AFB1+ samples for all liver disorders. Compared with NL, gene expression of cyclin D1 and PB in AFB1+ samples of HCC and AC were also higher, along with higher gene expression of p21 in VC and AC AFB1+ livers. Results indicated that patients with liver disorders were exposed to dietary aflatoxins, and that residual AFB1 in liver negatively affected the p53 and protein Rb pathways in HCC. Moreover, the presence of AFB1 in cirrhotic livers warrants concern about the potential contribution of dietary aflatoxin to disease progression during VC and AC.
RESUMO
The aim of the present study was to determine aflatoxin levels in peanut products traded in the Northeast region of São Paulo, Brazil. To this end, 240 samples of peanut products traded in the cities of Araras, Leme, Pirassununga and Porto Ferreira were collected from June 2006 to May 2007. The samples were analyzed for aflatoxins (AF) B(1), B(2), G(1) and G(2) by high performance liquid chromatography. Results showed 44.2% samples positive for AF at levels of 0.5 to 103.8 microg x kg(-1). Nine of the positive samples (3.7% of the analysed samples) had total aflatoxin concentrations (B(1)+B(2)+G(1)+G(2)) higher than the limit established by Brazilian regulations (20 microg x kg(-1)). Based on the above data, the probable mean daily intake (PDI(M)) of aflatoxins from peanut products in the Northeast region of São Paulo was estimated to be 0.23 ng kg b.w. day(-1). Although this PDI(M) value was relatively low, results indicate that aflatoxin contamination of peanut products may be a public health concern in Brazil, when considering the potential exposure of highly susceptible consumers. For example, it should be emphasized that children are potentially exposed to aflatoxins, since they consume large quantities of peanut candies, and these products had the highest number of samples positive for AFB(1).