IC50 shift determination for mitragynine towards CYP3A activity in HIM without NADPH CSV JSON

In Vitro Enzyme Inhibition Experiment

IC50 shift determination for mitragynine towards CYP3A activity in HIM without NADPH

Inhibition was detected.  Cutoff used —

IC50<10 µM for reversible inhibition and IC50shift ≥1.5 fold for time dependent inhibition

midazolam 708298

mitragynine

1'-hydroxymidazolam

  • CYP3A

Cell fraction Pooled human intestinal microsomes -7999663

Results

A 7-fold shift in IC50was observed towards CYP3A activity in HIM, 21.9 ±2.7 vs. 3.2 ±0.3 µM, in presence and absence of NADPH, respectively. [IC50values (Mean ± SEM) were determined using nonlinear least-squares regression]

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.

NA

0.05 mg/mL

Commercially available

1610314

NADPH

Available

Available

4 µM

250 µL

30 min

NADPH with no precipitant

200 µL

10 min

No dilution

0.015 - 100 µM

IC50 Shift Related Experiment