Study on the Estrogenic Activity of Di-(2-Ethylhexyl) Adipate in E-Screen Assay and Uterotrophic Assay

E-screen assay 및 자궁비대반응시험 (Uterotrophic assay)을 이용한 di-(2-ethylhexyl) adipate의 에스트로겐성 작용에 관한 연구

Di-(2-ethylhexyl) adipate(DEHA) has been used extensively as a plasticizer in the manufacture of plastic products such as PVC films. Though, phthalate esters plasticizers have been known to induce endocrine system-mediated responses, few studies have been conducted for the screening of estrogenic activity of DEHA, an adipate plasticizer. This study was initiated to evaluate the estrogenic activity of DEHA by in vitro E-screen assay and in vivo uterotrophic assay. MCF-7 human breast cancer cells were treated with $DEHA(5{\times}10^{-9}{\sim}5{\times}10^{-4}\;M)$, for 144 hr, and cell proliferation was determined by sulforhodamine B(SRB) assay. DEHA dissolved in corn oil was administered subcutaneously to ovariectomized(OVX) female Sprague-Dawley rats at dosage levels of 0, 2, 20 and 200 mg/kg/day for three consecutive days. Rats were sacrificed 24 hr after final treatment and vagina and uterus(wet and blotted) weights were obtained. E-screen assayed DEHA did not generate cell proliferation at treated concentrations$(5{\times}10^{-9}{\sim}5{\times}10^{-4}\;M)$, whereas 17 ${\beta}-estradiol$(E2), the positive control, induced cell proliferation at low concentrations$(5{\times}10^{-14}{\sim}5{\times}10^{-9}\;M)$. In the uterotrophic assay, DEHA did not change vagina and uterus(wet and blotted) weights at dosage levels up to 200 mg/kg/day treatment. These results demonstrated that DEHA did not exhibit the estrogenic activity as determined by in vitro E-screen assay and in vivo uterotrophic assay.

랩 등 PVC 제품의 가소제인 DEHA의 에스트로겐 활성을 검색하기 위하여 내분비계 장애작용 중 에스트로겐성 작용을 검색하는 대표적인 방법인 in vitro E-screen assay와 OECD 및 미국 EPA EDSTAC에서 권고하고 있는 in vivo 난소절제 랫드를 이용한 자궁 비대반응시험(uterotrophic assay)을 실시하였다. 시험결과 $DEHA(5{\times}10^{-9}{\sim}5{\times}10^{-4}\;M)$는 MCF-7세포의 증식을 유발하지 않았고 난소절제 랫드에 200 mg/kg/day 용량까지 투여하여도 자궁 및 질 무게에 영향을 미치지 않았다. 따라서 본 실험결과 DEHA는 E-screen assay 및 자궁비대반응시험에서 에스트로겐성 작용이 없는 것으로 확인되었으나, 이들 물질의 에스트로겐성에 대한 결론을 내리기 위해서는 여러 종류의 in vitro 시험 data 및 in vivo 시험 data가 더 보충되어야 할 것으로 생각된다.