Table 3.

Potencies of chemically distinct compounds in elevating NQO1 activity and in inhibiting LPS-stimulated iNOS activity in different cells, expressed as D_m values

Compound	Median effect concentration, Dm, μM
	RAW 264.7		WT macrophages		nrf2−/− macrophages
	Induction of NQO1	Inhibition of iNOS	Induction of NQO1	Inhibition of iNOS	Induction of NQO1	Inhibition of iNOS
RS-Sulforaphane	1.86	0.44	21.5	1.54	In	0.81
Triterpenoid TP-225	0.0035	0.0011	0.21	0.21	In	0.2
Bis(2-hydroxybenzylidene)acetone	7.58	0.26	12.3	1.67	In	1.97
Bis(4-hydroxybenzylidene)acetone	91.2	7.33	In	87.7	In	32.9
Phenyl arsenoxide	0.27	0.066	0.35	0.03	In	0.061
Sodium arsenite	7.37	0.87	14.8	3.85	In	9.32
2,3-Dimercaptopropanol (BAL)	75.4	8.14	100	30.8	In	46.6

Macrophages were incubated with serial dilution of test compounds in the presence of 10 ng/ml LPS for 48 h (RAW 264.7), or 100 ng/ml LPS for 24 h (WT and nrf2^−/− peritoneal macrophages). NO production was then measured as nitrite accumulation in the medium, and NQO1 activity was determined in cell lysates from the same wells. Control cells were treated with LPS only. The potencies (D_m) were determined by Median Effect Equation of Chou. Inactive (In) is defined as less than 10% induction of NQO1.