Development of an in vitro test battery for the screening of the receptor-mediated mechanism and the spindle-poison mode of action of estrogenic compounds

- In vitro test battery for estrogenic compounds reproductive toxicity screening.
- Aim to differentiate between receptor-mediated and the direct mechanism of action.
- Different biological assays: bovine oocytes and embryos, and two cell lines are used.
- Three out of four assays are informative about the biological pathway involved.

The implementation of the REACH regulation has imposed the urgent need of developing alternative testing methods to screen large number of compounds more quickly and at lower costs.In this study, a battery of tests, suitable for reproductive toxicology testing, was developed with the objective of detecting the mechanism of action of estrogenic and xenoestrogenic compounds. With this aim, two compounds known for their estrogenic activity, diethylstilbestrol and 17β-estradiol, were used to set up four different in vitro tests: 1) bovine oocyte in vitro maturation assay, 2) bovine preimplantation embryo in vitro culture assay and 3) MCF-7 and 4) BALB/3T3 cell lines proliferation and cytotoxicity assay, respectively. The results show that this battery of tests allows to identify and to distinguish between two major mechanisms of action of (xeno)estrogenic compounds: the receptor-mediated mechanism and the spindle-poison effect on microtubules polimerization.