Table 3.

Potency of the BEs and their preferential activities through ERβ vs. ERα in cellular (gene stimulation) and cell-free (ligand binding and coactivator binding) assays

Ligand	Potency from cellular activities			Potency from cell-free activities
	Gene stimulation, EC50 (nM)		β/α potency selectivity [relative to E2]	β/α selectivity RBA × RCA [relative to E2]	β/α RCA selectivity	β/α RBA selectivity
	ERβ only, OTUB2	ERα only, PgR
E2	1.67	0.02	0.012 [1.0]	[1.0]	[1.00]	[1.00]
Genistein	4	24	6 [500]	1750	5.4	324
S-equol	1.4	14	10 [830]	2600	108	24
Daidzein	50	200	4 [340]	1024	62	17
Liquiritigenin	60	300	5 [420]	400	19	21

OTUB2, otubain 2; PgR, progesterone receptor.