IC50 shift determination for mitragynine towards CYP2D6 activity in HLM with NADPH CSV JSON

Natural product: Kratom (Mitragyna speciosa)
Associated study: Refined Prediction of Pharmacokinetic Kratom-Drug Interactions: Time-Dependent Inhibition Considerations

In Vitro Enzyme Inhibition Experiment

IC50 shift determination for mitragynine towards CYP2D6 activity in HLM with NADPH

Inhibition was detected. Cutoff used —
IC₅₀<10 µM for reversible inhibition and IC₅₀shift ≥1.5 fold for time dependent inhibition

Object compound

dextromethorphan 1119510

Precipitant

mitragynine

Object metabolite investigated

dextrorphan 4349487

Enzymes involved in metabolite pathway

CYP2D6 4173631

Test system used

Cell fraction Pooled human liver microsomes -7999662

Results

Sample	Compound measured	Value	Measurement	Study sequence	Additional information	N replicates

Experimental Conditions

A cocktail of probe substrates for CYP2C9 (diclofenac), CYP2D6 (dextromethorphan), and CYP3A (midazolam) was used for the IC₅₀shift determination.
Methanol (0.8 % v/v) served as solvent control. Tienilic acid (0.4 and 0.8 µM), paroxetine (0.25 and 0.5 µM), and 6',7'-dihydroxybergamottin (1 and 2 µM) served as positive control inhibitors of CYP2C9, CYP2D6, and CYP3A activities, respectively.

Cell density

Protein concentration

0.05 mg/mL

Test system preparation

Commercially available

Test system lot number

1010191

Co-factors

NADPH

Protein linearity

Available

Time linearity

Available

Object concentrations tested

4 µM

Precipitant pre-incubation volume

250 µL

Precipitant pre-incubation time

30 min

Precipitant pre-incubation condition

NADPH with precipitant

Secondary enzyme activity incubation volume

200 µL

Secondary enzyme activity incubation time

10 min

Dilution factor

No dilution

Precipitant concentrations tested

0.015 - 100 µM

IC50 Shift Related Experiment

IC50 shift determination for mitragynine towards CYP2D6 activity in HLM without NADPH

NOTE