In Vitro Evaluation Of Endocrine Disruption Of Polybrominated Diphenyl Ethers

Polybrominated diphenyl ethers (PBDEs) as a kind of flame restardants are widely applied in industrial products, such as plastic, textile, construction material, etc. PBDEs have aroused great concern because of their wide spreading, stable structure, and potential risk to animal/human health. In charpter one, the application, chemical and physical properties and environmental behavior of PBDEs were introduced. The ecotoxicology of PBDEs, including reproductive developmental toxicity, neurotoxicity, immunotoxicity and endocrine disruption, were summarized. In particular, estrogenic activity of PBDEs and related research methods were clarified. The importance to study endocrine disruption of PBDEs at low dose was emphasized.Using the cell proliferation and pS2 gene expression in estrogen receptor (ER)-positive MCF-7 cells as endpoints, we investigated estrogenic effects of pure BDE-47, pure BDE-209, and equipotent binary mixture of BDE-47 and BDE-209 at low doses. The findings indicated that the test PBDEs suppressed cells proliferation at low concentrations and stimulated eel] proliferation at higher concentrations, and displayed a biphasic effects on human breast cancer cells. The above and related findings suggested that PBDEs may act as an agonist-antagonist, depending on the biological endpoint and the concentrations employed.Using CYP19 gene expression in H295R cells as endpoint, we investigated aromatase effects of pure BDE-47, pure BDE-209, and equipotent binary mixture of BDE-47 and BDE-209 at low doses. The findings indicated that the test PBDEs induced CYP19 gene expression at low concentrations (1～100 ng·L-1) and had no effect at higher concentrations (1000 ng·L-1).In order to explore preliminarily the potential risk of the complex pollutants containing PBDEs from E-waste treating areas, the complex pollutants containing PBDEs were extracted from Sanhuang chicken samples from an E-waste recycling region. Human breast cancer MCF-7 cells and MDA-MB-231 cells were exposed to the extracts for 6 d, and the cell proliferation and mRNA expression of pS2, an estrogen-target gene, were determined. Results showed that the extracts had no cytotoxic effects but suppressed significantly the cell proliferation and mRNA expression of pS2 in MCF-7 cells. The estracts exhibited anti-estrogenic activity. The results suggest that complex pollutants containing PBDEs from E-waste recyling region have certain potential risk for animal and human health.