Table 2.

Potencies of chemically distinct compounds in suppression of ROS in different cells, expressed as D_m values

Compound	Median effect concentration, Dm, μM
	RAW 264.7	WT macrophages	nrf2−/− macrophages
RS-Sulforaphane	3.14	9.48	In
Hexyl isothiocyanate	17.5	148	In
Bis(2-hydroxybenzylidene)acetone	0.60	3.64	In
Bis(4-hydroxybenzylidene)acetone	In	In	In
Sodium arsenite	3.78	13.9	In
Sodium arsenate	137	31.4	In
2,3-Dimercaptopropanol	7.78	187	17.8
Propane-1,3-dithiol	136	232	28.4
BAL/HgCl2 (1:1)	0.61	0.57	0.022

After 24 h of incubation with test compounds, the cells were exposed to 20 μM DCFH-DA for 30 min and then challenged with 500 μM tert-butyl hydroperoxide for 30 min. The fluorescence intensity was measured. Controls contained no test compounds, and the potencies (D_m) were determined by Median Effect Equation of Chou. Inactive (In) is defined as less than 10% suppression of ROS.