TABLE 5.
The Functional Activity of M. speciosa Alkaloids at Human Opioid Receptors in G protein BRET Assays (Kruegel et al., 2016).
| Compound | EC50 ± SEM (Emax) a or [ IC50 ± SEM (pA2)] b | ||
|---|---|---|---|
| hMOR | hKOR | hDOR | |
| Mitragynine (1) | 0.339 ± 0.178 (34%) (partial agonist) | 8.5 ± 7.6 (1.4) (competitive antagonist) | >10 (antagonist) |
| Speciogynine (2) | 5.7 ± 2.8 (weak antagonist effect) | >10 (weak antagonist effect) | >10 (weak antagonist effect) |
| Speciociliatine (3) | 4.2 ± 1.6 (weak antagonist effect) | >10 (weak antagonist effect) | >10 (weak antagonist effect) |
a
EC50 values indicate the agonist activity, (E max) relative to DAMGO, in parentheses.
b
IC50 values indicate the inhibition of a reference agonist, (pA2) determined from Schild analysis in parentheses.
All data points represent mean ± SEM (µM) of n ≥ 3.