TABLE 3.
The activity of DIM on CB1 and CB2 receptors in comparison with CP55940, anandamide, 2-AG, and arachidonic acid
The data are expressed as average ± S.D. of three or four experiments. Percentage of efficacy is calculated by normalizing the response range to that of a standard compound (CP55940 or 2-AG); the value shown is the average value of all the experiments.
| Receptor | Assay type | CP55940, EC/IC50 or Ki | DIM, EC/IC50 or Ki | Anandamide, EC/IC50 or Ki | 2-AG, EC/IC50 or Ki | Arachidonic acid, EC/IC50 or Ki |
|---|---|---|---|---|---|---|
| μm | μm | μm | μm | μm | ||
| CB2 | β-Arrestin assay (% of efficacy) | 0.0016 ± 0.0004 (100%) | 1.7 ± 1.3 (47%) | 0.74 ± 0.27 (51%) | 4.4 ± 3.2 (82%) | >10 |
| Ligand binding assay | 0.00022 ± 0.00008 | 1.1 ± 0.3 | 0.34 ± 0.13 | 0.59 ± 0.26 | 13 ± 3 | |
| GTPγS assay (% of efficacy) | 0.00028 ± 0.00005 (100%) | 0.98 ± 0.22 (37%) | 0.62 ± 0.32 (49%) | 0.32 ± 0.17 (95%) | 10 ± 4 (43%) | |
| cAMP-HTRF assay (% of efficacy) | 0.00038 ± 0.00008 (100%) | 0.42 ± 0.23 (43%) | ? (<20%) | 5.3 ± 2.3 (57%) | >10 | |
| CB1 | β-Arrestin assay (% of efficacy) | 0.00045 (100%) | >30, inhibition | 0.81 (67%) | 0.85 (>100%) | >10 |
| Ligand binding assay | 0.00024 ± 0.00008 | 4.3 ± 0.3 | 0.09 ± 0.01 | 0.25 ± 0.05 | 12 ± 5 | |
| GTPγS assay (% of efficacy) | ? | 11.1, inhibition | 0.44 (56%) | 0.32 (100%) | 4.2 (40%) | |
| cAMP-HTRF assay (% of efficacy) | 0.0005 | >30 | 3.5 (125%) | 3.4 (69%) | >10 |