Kratom (Mitragyna speciosa)
Evaluation of the Effects of Mitragyna speciosa Alkaloid Extract on Cytochrome P450 Enzymes Using a High Throughput Assay CSV JSON

The extract from Mitragyna speciosa has been widely used as an opium substitute, mainly due to its morphine-like pharmacological effects. This study investigated the effects of M. speciosa alkaloid extract (MSE) on human recombinant cytochrome P450 (CYP) enzyme activities using a modified Crespi method. As compared with the liquid chromatography-mass spectrometry method, this method has shown to be a fast and cost- effective way to perform CYP inhibition studies. The results indicated that MSE has the most potent inhibitory effect on CYP3A4 and CYP2D6, with apparent half-maximal inhibitory concentration (IC50) values of 0.78 μg/mL and 0.636 μg/mL, respectively. In addition, moderate inhibition was observed for CYP1A2, with an IC50 of 39 μg/mL, and weak inhibition was detected for CYP2C19. The IC50 of CYP2C19 could not be determined, however, because inhibition was <50%. Competitive inhibition was found for the MSE-treated CYP2D6 inhibition assay, whereas non-competitive inhibition was shown in inhibition assays using CYP3A4, CYP1A2 and CYP2C19. Quinidine (CYP2D6), ketoconazole (CYP3A4), tranylcypromine (CYP2C19) and furafylline (CYP1A2) were used as positive controls throughout the experiments. This study shows that MSE may contribute to an herb-drug interaction if administered concomitantly with drugs that are substrates for CYP3A4, CYP2D6 and CYP1A2.

1 . Unnamed Experiment (id=NPDI-payj8A)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — Not specified

  • CYP2D6 4173631

Recombinant expression system Not available
Cytochrome B5 Not available

Results

Ketoconazole was used as the positive control
(Table 2, Figure 2)

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

1.5 µM

Commercially available

30 min

NADPH regenerating system

2 . Unnamed Experiment (id=NPDI-MpwNXw)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — Not specified

3-cyano-7-ethoxycoumarin

Mitragynine

3-cyano-7-hydroxycoumarin

  • CYP1A2 4312402
  • CYP2C19 4311137

Recombinant expression system Not available
Cytochrome B5 Not available

Results

Furafylline is used as the positive control
(Table 2, Figure 2)

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

0.5 pmol/well

Commercially available

20 min

NADPH regenerating system

3 . Unnamed Experiment (id=NPDI-d5Gm3Q)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — Not specified

3-cyano-7-ethoxycoumarin

Mitragynine

3-cyano-7-hydroxycoumarin

  • CYP2C19 4311137

Recombinant expression system Not available
Cytochrome B5 Not available

Results

IC50 was not determined because inhibition was < 50%.
Tranylcypromine was used as a positive control.
(Table 2, Figure 2)

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

0.5 pmol/well

Commercially available

30 min

NADPH regenerating system

4 . Unnamed Experiment (id=NPDI-TZxzig)

In Vitro Enzyme Inhibition Experiment

Inhibition was detected.  Cutoff used — Not specified

Mitragynine

7-hydroxy-4-(trifluromethyl)-coumarin

  • CYP3A4 4306811

Recombinant expression system Not available
Cytochrome B5 Not available

Results

Quinidine was used as the positive control.
(Table 2, Figure 2)

Compound measured Measurement Value Study sequence Additional information N replicates

Experimental Conditions

1 pmol/well

30 min

NADPH regenerating system