We evaluated the effects of
mancozeb (Dithane M4-5), a protective
carbamate fungicide, on transplacental
carcinogenesis in Swiss albino mice.
Mancozeb, a polymeric complex of
ethylene bis (dithiocarbamate)
manganese with
zinc salt, is reported to possess carcinogenic and cocarcinogenic activity in various
tumor models. In the present study, pregnant Swiss albino mice were administered
mancozeb intraperitoneally on the 14th day of gestation. The first filial generation (F1 progeny) was promoted with a well-known
tumor promoter 12-o-tetradecanoyl phorbol-13-acetate (TPA). The results revealed a significantly high
tumor incidence (72%) in the F1 progeny of the animals initiated with
mancozeb or a well known
carcinogen 7,12-dimethyl
benzanthracene (DMBA) and promoted with TPA in comparison to animals that were either from mothers given only the vehicle (
DMSO) and promoted with TPA in F1 progeny or not promoted with TPA in F1 progeny. No significantly higher
tumor incidence was observed in any other experimental groups. These results suggest that
mancozeb or its metabolites are capable of crossing the placental barrier and can exert DNA damage and
tumor initiating consequences in the fetal cells that, after promotion with TPA, get converted into neoplastic cells.