Enantioselectivity in Estrogenic Potential and Uptake of Bifenthrin

Abstract

Despite the fact that the biological processes of chiral compounds are enantioselective, the endocrine disruption activity and uptake of chiral contaminants with respect to enantioselectivity has so far received limited research. In this study, the estrogenic potential and uptake of the enantiomers of a newer pyrethroid insecticide, 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 (i.e., the E-SCREEN 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 74.2% and 20.9%, respectively, and the relative proliferative potency ratios were 10% and 1%, 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 of the ER antagonist ICI 182,780. Measurement of vitellogenin induction in Japanese medaka (Oryzias latipes) showed that, at an exposure level of 10 ng/mL, the response to 1S-cis-BF was about 123 times greater than thattothe Renantiomer. Significant selectivity also occurred in the uptake of BF enantiomers in the liver and other tissues of J. medaka. These results together suggest that assessment of the environmental safety of chiral insecticides should consider enantioselectivity in acute and chronic ecotoxicities such as endocrine disruption.

Bioaccumulation and enantioselectivity of type I and type II pyrethroid pesticides in earthworm

“…The EF value reached a steady state of 0.10 as the duration of exposure. The faster degradation of (+)-enantiomer over (−)-enantiomer was consistent with previous investigation in J. Medaka and D. magna (Zhao et al, 2009;Wang et al, 2007). According to previous toxic study, the vitellogenin induction to (+)-BF was about 123 times greater than (−)-BF (Wang et al, 2007).…”

“…The faster degradation of (+)-enantiomer over (−)-enantiomer was consistent with previous investigation in J. Medaka and D. magna (Zhao et al, 2009;Wang et al, 2007). According to previous toxic study, the vitellogenin induction to (+)-BF was about 123 times greater than (−)-BF (Wang et al, 2007). The toxic experiment in mice also showed that (+)-BF was much more toxic in hepatic oxidative stress than (−)-BF (Jin et al, 2013).…”

Exploring the Impacts of Two Separate Mixtures of Pesticide and Surfactants on Estrogenic Activity in Male Fathead Minnows and Rainbow Trout

“…In fish, diuron has been shown to act as a weak antiandrogen by competitively binding to the androgen receptor (Thibaut and Porte 2004). Bifenthrin is a pyrethroid pesticide that binds the voltage-gated sodium channels in neurons, and it has been shown to be estrogenic in several species of fish (Brander et al 2012;Wang et al 2007). Recent monitoring studies have identified bifenthrin in concentrations ranging from 1 to 106 ng/L in northern California (Weston and Lydy 2012;Weston et al 2013).…”

Enantioselective interaction with acetylcholinesterase of an organophosphate insecticide fenamiphos

“…2 It is well established that the opposite enantiomers of chiral pesticides often differ significantly in environmental impact, including biodegradation, 3 bioaccumulation, 4,5 aquatic toxicity 6 and endocrine disruption. 7 However, our understanding of the molecular mechanism of enantioselectivity is still limited.…”