IC50 shift determination for mitragynine towards CYP2C9 activity in HLM without 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 CYP2C9 activity in HLM without NADPH

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

Object compound

diclofenac 1124300

Precipitant

mitragynine

Object metabolite investigated

4'-hydroxydiclofenac

Enzymes involved in metabolite pathway

CYP2C9 4309227

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 no 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 CYP2C9 activity in HLM with NADPH

NOTE