Estrogenicity of enantiomers of the synthetic pyrethroid insecticide (Z)-cis-bifenthrin

AGRO 120

Weiping Liu, wliu@zjut.edu.cn, Research Center of Green Chirality, Zhejiang University of Technology, College of Biological and Environmental Engineering, Hangzhou, 310032, China, Guangyao Sheng, dansheng@zjut.edu.cn, Research Center of Environmental Science, Zhejiang University of Technology, College of Biological and Environmental Engineering, Hangzhou, 310032, China, Lumei Wang, lmwang@zju.edu.cn, Zhejiang University, Institute of Environmental Science, Hangzhou, 310027, Caixia Yang, cyang@zjut.edu.cn, College of Biological and Environmental Engineering, Research Center of Green Chiralty, Zhejiang University of Technology, Hangzhou, 310032, and Jay Gan, jgan@ucr.edu, Department of Environmental Sciences, University of California Riverside, Riverside, CA 92521.
Despite the fact that the biological processes of chiral compounds are enantioselective, the endocrine disruption activity of chiral contaminants with respect to enantioselectivity has so far received limited research. In this study, the estrogenic potential of enantiomers of the synthetic pyrethroid insecticide (Z)-cis-bifenthrin (BF) were investigated. Significant differences in estrogenic potential were observed between the two enantiomers in the in vitro human breast carcinoma MCF-7 cell proliferation assay and the in vivo aquatic vertebrate vitellogenin enzyme-linked immunosorbent assay (ELISA). In the E-SCREEN assay, the relative proliferative effect ratios of 1S-cis-BF and 1R-cis-BF were 85.3% and 38.1%, respectively, and the relative proliferative potency ratios were 100% and 10%, respectively. The cell proliferation induced by the two BF enantiomers may be through the classical estrogen response pathway via the estrogen receptor (ER) as the proliferation induced by the enantiomers could be completely blocked when combined with 10^-6 mol/L antiestrogen ICI 182,780. Measurement of vitellogenin induction in Japanese medaka (Oryzias latipes) showed that the estrogenic potency of 1S-cis-BF was about 123 times stronger than that of 1R-cis-BF. These results suggest that assessment of the environmental safety of chiral insecticides should take enantioselectivity in acute and chronic ecotoxicities (e.g., endocrine disruption) into consideration.
 

Modern Chiral Agrochemicals
8:30 AM-12:15 PM, Wednesday, August 22, 2007 BCEC -- 259B, Oral

Division of Agrochemicals

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007