Synergistic interaction between excess hepatic iron and alcohol ingestion in hepatic mutagenesis.
OBJECTIVE
Hereditary hemochromatosis (HH) and dietary iron overload are the main iron-loading diseases. Fibrosis, cirrhosis and hepatocellular carcinoma (HCC) are complications to HH and dietary iron overload possibly influenced by co-factors. Alcohol may be one such factor. The aim therefore was to determine the extent of synergistic interaction between free hepatic iron and alcohol, complicating dietary iron overload in HCC pathogenesis.


METHODS
Four groups of 20 Wistar albino rats were used: group 1 (C) was fed the chow diet; group 2 (Fe) was supplemented with 0.75% ferrocene iron; group 3 (Fe+Al), 0.75% iron and 7% ethanol; and group 4, 7% ethanol (Al) for 12 months. Iron profile, superoxide/nitrite free radicals, lipid peroxidation (LPO)/8-isoprostane (8-IP), 8-hydroxydeoxyguanosine (8-OHdG), oxidative lipid/DNA damage immunohistochemistry, transaminases (AST/ALT) and Ames mutagenesis tests were performed.


RESULTS
Significant differences were observed in the Fe+Al group for LPO, 8-IP, AST and ALT (p<0.001, 0.001, 0.001 and 0.001, respectively) compared to other groups. A three-fold synergistic interaction was observed for the same parameters. Furthermore, significant differences of p<0.05 and 0.001 were observed for 8-OHdG and mutagenesis, respectively, with an additive synergy in the Fe+Al group. ALT/8-OHdG and ALT/mutagenesis correlated positively (p<0.04 and 0.008, respectively). The immunohistochemistry revealed iron/alcohol multiplicative synergism with hydroxyl radical involvement.


CONCLUSIONS
Mutagenic effects of iron and alcohol are synergistically multiplicative implicating hydroxyl free radicals in hepatocarcingenesis.
Asare
George A
GA
MRC/University Molecular Hepatology Research Unit, Department of Medicine, University of the Witwatersrand, Johannesburg, South Africa.
Bronz
Michelle
M
Naidoo
Vivash
V
Kew
Michael C
MC
D000428:Alcohol Drinking / Q000009:adverse effects*; D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000139:chemically induced* / Q000378:metabolism; D004249:DNA Damage; D004357:Drug Synergism; D017665:Hydroxyl Radical / Q000378:metabolism; D007501:Iron / Q000378:metabolism*; D019190:Iron Overload / Q000378:metabolism; D015227:Lipid Peroxidation; D008099:Liver / Q000378:metabolism*; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced* / Q000378:metabolism; D016296:Mutagenesis; D051381:Rats; D017208:Rats, Wistar
D017665:Hydroxyl Radical; D007501:Iron