Study on the Effect of Neonatal Exposure to Zearalenone on Mammary Gland of Female Mice

Zearalenone is an estrogenic compound synthesized by Fusarium molds , a toxin withcontaminant in food as a result of infection of grain. Zearalenone can enter the human foodchain directly via ingestion of contaminated grain. Estrogens play important roles in themaintenance and function of the reproductive tract and mammary glands. The effects ofneonatals exposure to zearalenone, estrogenic compound that stimulates growth of MCF-7human breast cancer cell, were examined in females mice mammary glands tissue. In thisstudy 20 females were examined. Female mice were divided into two groups. Control groupreceived sesame oil and treatment group received Zearalenone (0.5, 1.0, or 2.0 mg/kg/days)per1 to 5 days after birth subcutaneously. All animals were perfused with paraformaldehydein 70 days , and mammary glands were removed and post-fixed in paraformaldehyde. Crosssectionsof mammary glands were stained with hematoxyline and eosine and were evaluatedhistologically. In this study, we found no change in body weight of animals that receivedzearalenone comparable to control group. Also some ducts were irregularly thickened, andsome end buds were expanded, which could suggest abnormal proliferation of the mammarygland. In study strongly support the role of zearalenone as a disruptor of mammary glanddevelopment when the toxin is given during critical periods such as neonatal life. Mammaryglands are also sensitive to estrogenic chemicals, and timing and dosage of exposure ofimmature animals to xenoestrogens influence the development of mammary tumors. It issuggested that exposure of prepubertal mice to zearalenone causes an increase in mammarygland tumorigenic potential ,when the inside body estrogen level is low.

Keywords:

Zearalenone , Mamary Gland , Estrogen , Mice , Tumorogenesis