Estrogenic potential of certain pyrethroid compounds in the MCF-7 human breast carcinoma cell line.

Abstract

Estrogens, whether natural or synthetic, clearl inluence reproductive development, senescence, and carcinogenesis. Pyrethroid insecticides are now the most widely used agents for indoor pest control, providing potential for human exposure. Using the MCF-7 human breast carcinoma cel line, we stdied the estrogenic potential of several sthetic pyrethroid mpounds in vitro usig pS2 mRNA levels as the end point. We tested sumitin, tfenvalerate trans alletbrin, and permethrin. Nanomolar concentrations of either sumithin or fenvalerate were sufficient to increase pS2 expression slighdy above basal levels. At micromolar concentmtions, these two pyrethroid compounds induced pS2 expression to levels comparable to those elicited by 10 nM 17f.estradiol (fivefold). The estrogenic activity of sumithrin was abolished with co-treatment with an antiestrogen (ICI 164,384), whereas estrogenic activity of fenvalerate was not si y diminished with antiestrogen co-treatment. In addition, both sumithini and fenvalerate were:able to induce ei proliferation of MCF-7 cells in a se-response fashion. Neither perm in nor d-trans allethrin affected pS2 expression. Perme had a noticeable effect on cel proliferation at 100 pM, whereas d-trans allethin slightdy induced MCF-7 cell prolieration at 10 pM, but was toxic at higher concentrtions. Overall, our studies imply that each pyrethroid compound is unique in its ability to influence several cellular pathways. These finding sugget that pyrethroids should be considered to be hormio disrunptors, and ther potentidal to affect edocrine fimction n' human and widlif should be inivestigated. Key word 173-estradiol, MCF-7 human breast carcinoma cells, pS2, pyrethroid, RNA.

Occurrence of endocrine-disrupting chemicals in indoor dust

“…Although pyrethroids are known to be extremely toxic to fish and bees, they are much less toxic for mammals. However, recent studies provide evidence that high exposure to pyrethroids may cause cancers (Tisch et al, 2002; Choi et al, 2004; Gabbianelli et al, 2004) and potential endocrine disruption in humans (Go et al, 1999). These effects were reported at levels that were regarded as safe.…”

Assessing indoor air exposures using passive sampling with bioanalytical methods for estrogenicity and aryl hydrocarbon receptor activity

“…In addition, PBDEs would be resistant to H 2 SO 4 treatment, and in most cases, estrogenicity was reduced with treatment, suggesting the importance of other compounds for the observed effects. More comprehensive chemical analysis in combination with relative potency estimates for individual known xenoestrogens (bisphenol A, as well as certain phthalates, alkylphenols, pyrethroid and organochlorine pesticides [49, 64, 65] for example) would be required to determine the proportion of response potentially attributable to these compounds.…”

Determination of the pyrethroid insecticide metabolite 3-PBA in plasma and urine samples from farmer and consumer groups in northern Thailand

“…[6,7] Pyrethroids may be considered hormone disruptors from studies on their estrogenic potential in human breast carcinoma cells. [8] Because of the potential toxicity, the U.S. EPA set a Reference Dose (RfD) of 0.25 mg/kg/day for both acute and chronic dietary exposures to permethrin. [9] The World Health Organization (WHO) has set a limit of 0.3 mg/L (300 ng/mL) as a guideline for permethrin in drinking water when it is applied to water for mosquito control.…”