Table 2. IC ₅₀ values for the inhibitory effects of the test drugs (compounds and reference inhibitors) on the enzymatic activity of human MAO-B (rational assays selected by our modeling), human MAO-A (control assays not selected by the modeling) and human COX-1 (control assays not selected by the modeling).

DRUG	IC50 hMAO-B (μM)	IC50 hMAO-A (μM)	IC50 hCOX-1 (μM)
Piperlongumine	65.07 ± 2.99	**	**
Frentizole	**	**	**
Ethoxzolamide	24.57 ± 1.09	**	**
Selegiline (Reference inhibitor)	0.019 ± 0.001
Iproniazide (Reference inhibitor)	7.54 ± 0.36	6.56 ± 0.76
Moclobemide (Reference inhibitor)		0.36 ± 0.02
FR122047 (Reference inhibitor)			0.094 ± 0.006

Each IC₅₀ value is the mean ± S.E.M. from three experiments (n = 3). ** Inactive at 100 μM (highest concentration tested).