Applicability of the OECD 455 in-vitro assay for determination of hERa agonistic activity of isoflavonoids
2020
Abstract
Isoflavonoids are considered to be natural estrogens, however the extrent of their estrogenic activity is a subject of disputation. The estrogenic activities of aglycones as well as of O-methylated and glycosylated isoflavonoids and their metabolites were evaluated.
Supra-maximal luciferase activity was seen for most of the flavonoids tested at concentrations even below 1 mu M. However, at concentrations above 1 mu M, non-specific interactions were also observed.
Instead of EC50 values, which could not be determined for most of the isoflavonoids tested, the concentrations corresponding to 10% (PC10) and 50% (PC50) of the maximum activity of the positive control, E2, were used for quantitative determination of estrogenic activities.