Estrogenic and androgenic activity of tert-butyl phenolic antioxidants assessed by in vitro receptor transcriptional activation and their association with in silico molecular docking analysis

Tert-butyl phenolic antioxidants (TBP-AOs) are utilized in a variety of consumer products, including food packaging, daily use items, and industrial applications. Their widespread use raises significant concerns regarding potential health risks, particularly endocrine disruption. However, our understanding of many TBP-AOs concerning endocrine systems remains limited, underscoring the need for screening of their hormonal activities and better insight into their adverse outcome pathways (AOPs). Transcriptional activation (TA) assays are crucial experimental tools in the early stages of risk assessment. This study evaluated the estrogenic and androgenic characteristics of 30 TBP-AOs through TA assays in hERα-HeLa-9903 and 22Rv1/MMTV_GR-KO cell lines, respectively, augmented by docking simulation using CB-Dock2. Our findings identified 21 estrogen receptor (ER) agonists, one ER antagonist, and eight androgen receptor (AR) antagonists, with significant correlations between biological activity and docking scores for specific proteins: 1GWR_C4 and 7KBS_C2 for ERα, and 2AM9_C1 for AR. These results enhance our understanding of TBP-AOs' toxicity on the endocrine system and confirm that TA assays and docking are effective methods for evaluating their endocrine activities. This research lays the foundation for future studies on endocrine disruptors, aiming to elucidate the mechanisms underlying molecular initiating events and key events within AOPs for TBP-AOs and other chemicals.