Effects of tris(2,3-dibromopropyl) isocyanurate on steroidogenesis in H295R cells

Tris(2,3-dibromopropyl) isocyanurate (TBC) is widely used in polymer products. It is ubiquitously found in environmental matrices. Previous studies have shown that TBC has potential endocrine-disrupting effects on aquatic organisms. However, the effects on adrenocortical function and the underlying mechanisms are not well characterized. In present study, the H295R cell line was employed to investigate the potential endocrine-disrupting action of TBC. TBC inhibited basal and forskolin-induced sex hormone production but did not exhibit cytotoxicity. The expression of the steroidogenic genes, StAR, 3 beta HSD2, CYP17, CYP21, CYP19, HMGR, 17 beta HSD1, 17 beta HSD4 and CYP11A, was not changed upon TBC exposure. However, the cAMP inducer forskolin strongly induced the expression of all these genes, except for HMGR, 17 beta HSD1 and 17 beta HSD4. TBC blocked forskolin-induced StAR, 3 beta HSD2, CYP17, CYP21 and CYP19 mRNA expression. Our results indicate that TBC can inhibit sex hormone biosynthesis due to the interference with steroidogenic gene transcription in activated condition.