Green tea (Camellia sinensis)
Identification of Intestinal UDP-Glucuronosyltransferase Inhibitors in Green Tea (Camellia sinensis) Using a Biochemometric Approach: Application to Raloxifene as a Test Drug via In Vitro to In Vivo Extrapolation
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Green tea is a commonly consumed beverage worldwide; thus, identifying green tea-drug interactions would be of high impact. The potential for UDP-glucuronosyltransferase (UGT)-based interactions are relatively understudied, particularly those in the intestine. As with all botanical dietary supplements, green tea is a complex and variable mixture of diverse phytoconstituents. Comprehensive, high-throughput, robust methods are needed to identify candidate precipitants of interactions with drugs. Using a biochemometrics approach that combines chemometrics with established bioassays, intestinal UGT inhibitors in green tea were identified and evaluated for their in vivo interaction potential. Four widely available green teas that were chemically similar to the National Institute of Standards and Technology (NIST) leaf reference material were selected for evaluation as inhibitors of intestinal UGT activity using human intestinal microsomes. Extracts and five fractions (prepared from the original extracts) of each tea were tested (20, 60, 180 µg/mL) using the nonspecific fluorescent substrate 4-methylumbelliferone. Fractions rich in UGT inhibitory constituents were identified via mass spectrometry-based untargeted metabolomics; these fractions were fractionated further and subjected to biochemometric analysis to identify individual UGT inhibitors. The Ki of two of these constituents and the original extract of a representative tea were determined using raloxifene a clinically relevant substrate. The Ki values were applied to a mechanistic static model to evaluate the potential for a green tea-raloxifene interaction in vivo. Effects of the extracts and fractions from all four teas were qualitatively similar, inhibiting intestinal UGT activity in a concentration-dependent manner (by 0 to >95% relative to vehicle control). The UGT inhibitory constituents tended to reside in the more hydrophilic subfractions of the fraction prepared from the representative extract. (−)-Epigallocatechin gallate (EGCG) and (−)-epicatechin gallate (ECG), two abundant catechins contained in green tea, were identified as major UGT inhibitors in these subfractions. Ki values were 2.0 and 0.8-1.0 μM, respectively, which were ~100x lower than concentrations measured in a 240-mL cup of hot tea prepared from the NIST leaf reference material. A biochemometric approach, which combines bioactivity data with chemometric analysis, was successfully applied to green tea for identifying intestinal UGT inhibitors that could precipitate an interaction with raloxifene and other UGT substrates (e.g., raltegravir, ezetimibe, and mycophenolic acid). This comprehensive approach could be applied to other natural products with drug interaction potential.
1 . Inhibition of UGT by (-)-Epigallocatechin Gallate (IC50 Determination) (id=NPDI-7el55g)
In Vitro Enzyme Inhibition Experiment
Inhibition was detected. Cutoff used — Not provided
- UGT
Cell fraction Individual human intestinal microsomes -7999704
Results
| Sample | Compound measured | Value | Measurement | Study sequence | Additional information | N replicates |
|---|
Experimental Conditions
Bovine serum albumin (0.05%) was added into the incubation system.
0.2 mg/mL
Commercially available
1410074
UDPGA
Not available
Not available
100 µM
3.9-600 µM
2 . Inhibition of UGT by (-)-Epigallocatechin Gallate (Screening) (id=NPDI-EczRtA)
In Vitro Enzyme Inhibition Experiment
Inhibition was detected. Cutoff used — 50% inhibition vs. control
- UGT
Cell fraction Pooled human intestinal microsomes -7999663
Results
Percent inhibition was estimated from Fig. S1.
| Sample | Compound measured | Value | Measurement | Study sequence | Additional information | N replicates |
|---|
Experimental Conditions
Purified green tea catechins were tested as inhibitors of UGT enzymes as described in Gufford et al., 2014 (Drug Metab Dispos. 2014 Oct;42(10):1675-83); information regarding incubation volume, time, and protien linearity were obtain therein.
Bovine serum albumin (0.05%) was added into the incubation system.
0.2 mg/mL
Commercially available
1410074
150 µL
20 min
UDPGA
Available
Not available
100 µM
100 µM
Control Experiment Information
3 . Inhibition of UGT by (-)-Epicatechin Gallate (IC50 determination) (id=NPDI-AXdpJA)
In Vitro Enzyme Inhibition Experiment
Inhibition was detected. Cutoff used — Not provided
- UGT
Cell fraction Pooled human intestinal microsomes -7999663
The precipitant used was (-)-epicatechin gallate.
Results
| Sample | Compound measured | Value | Measurement | Study sequence | Additional information | N replicates |
|---|
Experimental Conditions
Bovine serum albumin (0.05%) was added into the incubation system.
0.2 mg/mL
Commercially available
1410074
UDPGA
Not available
Not available
100 µM
3.9-800 µM
4 . Inhibition of UGT by (-)-Epicatechin Gallate (Screening) (id=NPDI-CWM_sQ)
In Vitro Enzyme Inhibition Experiment
Inhibition was detected. Cutoff used — 50% inhibition vs. control
- UGT
Cell fraction Pooled human intestinal microsomes -7999663
The precipitant used was (-)-epicatechin gallate.
Results
Percent inhibition was estimated from Fig. S1.
| Sample | Compound measured | Value | Measurement | Study sequence | Additional information | N replicates |
|---|
Experimental Conditions
Purified green tea catechins were tested as inhibitors of UGT enzymes as described in Gufford et al., 2014 (Drug Metab Dispos. 2014 Oct;42(10):1675-83); information regarding incubation volume, time, and protein linearity were obtain therein.
Bovine serum albumin (0.05%) was added into the incubation system.
0.2 mg/mL
Commercially available
1410074
150 µL
20 min
UDPGA
Available
Not available
100 µM
100 µM
Control Experiment Information
5 . Unnamed Experiment (id=NPDI-y3-V_w)
In Vitro Enzyme Inhibition Experiment
Inhibition was detected. Cutoff used — 50% inhibition vs. control
- UGT
Cell fraction Pooled human intestinal microsomes -7999663
Methanol extracts and (sub)fractions (five fractions obtained using a 4 g silica gel column and a hexane-chloroform-methanol mobile phase at 18 mL/min; normal phase chromatography) from four widely-avaliable commercial teas were used.
Results
Extracts, fractions, and subfractions from the four green teas inhibited intestinal UGT activity in a concentration-dependent manner (by 30-100% relative to vehicle control, estimated from Fig. 3). The UGT inhibitory constituents tended to reside in the more hydrophilic subfractions of the fraction prepared from the representative extract. (−)-Epigallocatechin gallate (EGCG) and (−)-epicatechin gallate (ECG), two abundant catechins contained in green tea, were identified as major UGT inhibitors in these subfractions.
| Sample | Compound measured | Value | Measurement | Study sequence | Additional information | N replicates |
|---|
Experimental Conditions
Green tea extracts, fractions, and subfractions were tested as inhibitors of UGT enzymes as described in Gufford et al., 2014 (Drug Metab Dispos. 2014 Oct;42(10):1675-83); information regarding incubation volume, time, and protein linearity were obtain therein.
Bovine serum albumin (0.05%) was added into the incubation system.
0.2 mg/mL
Commercially available
1410074
150 µL
20 min
UDPGA
Available
Not available
100 µM
20, 60, and 180 µg/mL
6 . Inhibition of UGT1A1, 1A8, and 1A10 by (-)-Epicatechin (Screening) (id=NPDI-wl1otQ)
In Vitro Enzyme Inhibition Experiment
Inhibition was detected. Cutoff used — 50% inhibition vs. control
- UGT1A1 40782950
- UGT1A10
- UGT1A8
Cell fraction Pooled human intestinal microsomes -7999663
Information regarding enzymes involved in the formation of raloxifene metabolites was obtained from Gufford et al., 2015 (Drug Metab Dispos. 2015 Sep;43(9):1353-9).
Results
At 10 µM (-)-epicatechin did not signficiantly inhibit the formation of raloxifene 4'-glucuronide. Percent inhibition value was estimated from Fig. S2.
| Sample | Compound measured | Value | Measurement | Study sequence | Additional information | N replicates |
|---|
Experimental Conditions
Commercially available
1410074
Not available
Not available
100 µM
Control Experiment Information
7 . Inhibition of UGT1A1, 1A8, and 1A10 by (-)-Epicatechin (Screening) (id=NPDI-VlvwrQ)
In Vitro Enzyme Inhibition Experiment
Inhibition was detected. Cutoff used — 50% inhibition vs. control
- UGT1A1 40782950
- UGT1A10
- UGT1A8
Cell fraction Pooled human intestinal microsomes -7999663
Information regarding enzymes involved in the formation of raloxifene metabolites was obtained from Gufford et al., 2015 (Drug Metab Dispos. 2015 Sep;43(9):1353-9).
Results
At 10 µM (-)-epicatechin did not signficiantly inhibit the formation of raloxifene 6-glucuronide. Percent inhibition value was estimated from Fig. S2.
| Sample | Compound measured | Value | Measurement | Study sequence | Additional information | N replicates |
|---|
Experimental Conditions
Commercially available
1410074
Not available
Not available
100 µM
Control Experiment Information
8 . Inhibition of UGT1A1, 1A8, and 1A10 by (-)-Epigallocatechin (Screening) (id=NPDI-Xe-X8A)
In Vitro Enzyme Inhibition Experiment
Inhibition was detected. Cutoff used — 50% inhibition vs. control
- UGT1A1 40782950
- UGT1A10
- UGT1A8
Cell fraction Pooled human intestinal microsomes -7999663
Information regarding enzymes involved in the formation of raloxifene metabolites was obtained from Gufford et al., 2015 (Drug Metab Dispos. 2015 Sep;43(9):1353-9).
Results
At 10 µM (-)-epigallocatechin did not signficiantly inhibit the formation of raloxifene 4'-glucuronide. Percent inhibition value was estimated from Fig. S2.
| Sample | Compound measured | Value | Measurement | Study sequence | Additional information | N replicates |
|---|
Experimental Conditions
Commercially available
1410074
Not available
Not available
100 µM
Control Experiment Information
9 . Inhibition of UGT1A1, 1A8, and 1A10 by (-)-Epigallocatechin (Screening) (id=NPDI-m23CAQ)
In Vitro Enzyme Inhibition Experiment
Inhibition was detected. Cutoff used — 50% inhibition vs. control
- UGT1A1 40782950
- UGT1A10
- UGT1A8
Cell fraction Pooled human intestinal microsomes -7999663
Information regarding enzymes involved in the formation of raloxifene metabolites was obtained from Gufford et al., 2015 (Drug Metab Dispos. 2015 Sep;43(9):1353-9).
Results
At 10 µM (-)-epigallocatechin did not signficiantly inhibit the formation of raloxifene 6-glucuronide. Percent inhibition value was estimated from Fig. S2.
| Sample | Compound measured | Value | Measurement | Study sequence | Additional information | N replicates |
|---|
Experimental Conditions
Commercially available
1410074
Not available
Not available
100 µM
Control Experiment Information
10 . Inhibition of UGT1A1, 1A8, and 1A10 by (-)-Epigallocatechin Gallate (Screening) (id=NPDI-rX0CIg)
In Vitro Enzyme Inhibition Experiment
Inhibition was detected. Cutoff used — 50% inhibition vs. control
- UGT1A1 40782950
- UGT1A10
- UGT1A8
Cell fraction Pooled human intestinal microsomes -7999663
Information regarding enzymes involved in the formation of raloxifene metabolites was obtained from Gufford et al., 2015 (Drug Metab Dispos. 2015 Sep;43(9):1353-9).
Results
At 10 µM (-)-epigallocatechin gallate inhibited the formation of raloxifene 6-glucuronide by about 50%. Percent inhibition values were estimated from Fig. S2.
| Sample | Compound measured | Value | Measurement | Study sequence | Additional information | N replicates |
|---|
Experimental Conditions
Commercially available
1410074
Not available
Not available
100 µM
Control Experiment Information
11 . Inhibition of UGT1A1, 1A8, and 1A10 by (-)-Epigallocatechin Gallate (Ki determination) (id=NPDI-XIaDNg)
In Vitro Enzyme Inhibition Experiment
Inhibition was detected. Cutoff used — Not provided
- UGT1A1 40782950
- UGT1A10
- UGT1A8
Cell fraction Pooled human intestinal microsomes -7999663
Information regarding enzymes involved in the formation of raloxifene metabolites was obtained from Gufford et al., 2015 (Drug Metab Dispos. 2015 Sep;43(9):1353-9).
Results
Using methods 1 and 2 provided by the authors, enterocyte concentrations for (-)-epigallocatechin gallate were estimated to be 17.2 and 0.60 µM, respectively, after administration of one bag of T21 green tea. With the Ki value of approximately 2 µM, the corresponding AUCi/AUC ratios were predicted to be 6.5 and 1.3, respectively.
| Sample | Compound measured | Value | Measurement | Study sequence | Additional information | N replicates |
|---|
Experimental Conditions
0.05 mg/mL
Commercially available
1410074
4 min
UDPGA
Not available
Not available
0.25-10 µM
1-16 µM
12 . Inhibition of UGT1A1, 1A8, and 1A10 by (-)-Epigallocatechin Gallate (Ki determination) (id=NPDI-8CdNjg)
In Vitro Enzyme Inhibition Experiment
Inhibition was detected. Cutoff used — Not provided
- UGT1A1 40782950
- UGT1A10
- UGT1A8
Cell fraction Pooled human intestinal microsomes -7999663
Information regarding enzymes involved in the formation of raloxifene metabolites was obtained from Gufford et al., 2015 (Drug Metab Dispos. 2015 Sep;43(9):1353-9).
Results
Using methods 1 and 2 provided by the authors, enterocyte concentrations for (-)-epigallocatechin gallate were estimated to be 17.2 and 0.60 µM, respectively, after administration of one bag of T21 green tea. With the Ki value of approximately 2 µM, the corresponding AUCi/AUC ratios were predicted to be 6.5 and 1.3, respectively.
| Sample | Compound measured | Value | Measurement | Study sequence | Additional information | N replicates |
|---|
Experimental Conditions
0.05 mg/mL
Commercially available
1410074
4 min
UDPGA
Not available
Not available
0.25-10 µM
1-16 µM
13 . Inhibition of UGT1A1, 1A10, and 1A8 by (-)-Epigallocatechin Gallate (Screening) (id=NPDI-uGwaFA)
In Vitro Enzyme Inhibition Experiment
Inhibition was detected. Cutoff used — 50% inhibition vs. control
- UGT1A1 40782950
- UGT1A10
- UGT1A8
Cell fraction Pooled human intestinal microsomes -7999663
Information regarding enzymes involved in the formation of raloxifene metabolites was obtained from Gufford et al., 2015.
Results
At 10 µM (-)-epigallocatechin gallate inhibited the formation of raloxifene 4'-glucuronide by about 50%. Percent inhibition values were estimated from Fig. S2.
| Sample | Compound measured | Value | Measurement | Study sequence | Additional information | N replicates |
|---|
Experimental Conditions
Commercially available
1410074
Not available
Not available
100 µM
Control Experiment Information
14 . Inhibition of UGT1A1, 1A8, and 1A10 by (+)-catechin (Screening) (id=NPDI-ubCatg)
In Vitro Enzyme Inhibition Experiment
Inhibition was detected. Cutoff used — 50% inhibition vs. control
- UGT1A1 40782950
- UGT1A10
- UGT1A8
Cell fraction Pooled human intestinal microsomes -7999663
Information regarding enzymes involved in the formation of raloxifene metabolites was obtained from Gufford et al., 2015 (Drug Metab Dispos. 2015 Sep;43(9):1353-9).
Results
At 10 µM (-)-gallocatechin did not signficiantly inhibit the formation of raloxifene 6-glucuronide. Percent inhibition value was estimated from Fig. S2.
| Sample | Compound measured | Value | Measurement | Study sequence | Additional information | N replicates |
|---|
Experimental Conditions
Commercially available
1410074
Not available
Not available
100 µM
Control Experiment Information
15 . Inhibition of UGT1A1, 1A8, and 1A10 by (+)-catechin (Screening) (id=NPDI-TIvDHw)
In Vitro Enzyme Inhibition Experiment
Inhibition was detected. Cutoff used — 50% inhibition vs. control
- UGT1A1 40782950
- UGT1A10
- UGT1A8
Cell fraction Pooled human intestinal microsomes -7999663
Information regarding enzymes involved in the formation of raloxifene metabolites was obtained from Gufford et al., 2015 (Drug Metab Dispos. 2015 Sep;43(9):1353-9).
Results
At 10 µM (-)-gallocatechin did not signficiantly inhibit the formation of raloxifene 4'-glucuronide. Percent inhibition value was estimated from Fig. S2.
| Sample | Compound measured | Value | Measurement | Study sequence | Additional information | N replicates |
|---|
Experimental Conditions
Commercially available
1410074
Not available
Not available
100 µM
Control Experiment Information
16 . Inhibition of UGT1A1, 1A8, and 1A10 by (-)-Epicatechin Gallate (Ki determination) (id=NPDI-WIQ_6A)
In Vitro Enzyme Inhibition Experiment
Inhibition was detected. Cutoff used — Not provided
- UGT1A1 40782950
- UGT1A10
- UGT1A8
Cell fraction Pooled human intestinal microsomes -7999663
The precipitant used was (-)-epicatechin gallate. Information regarding enzymes involved in the formation of raloxifene metabolites was obtained from Gufford et al., 2015 (Drug Metab Dispos. 2015 Sep;43(9):1353-9).
Results
Using methods 1 and 2 provided by the authors, enterocyte concentrations for (-)-epicatechin gallate were estimated to be 8.5 and 0.29 µM, respectively, after administration of one bag of T21 green tea. With the Ki value of approximately 1 µM, the corresponding AUCi/AUC ratios were predicted to be 6.5 and 1.3, respectively.
| Sample | Compound measured | Value | Measurement | Study sequence | Additional information | N replicates |
|---|
Experimental Conditions
0.05 mg/mL
Commercially available
1410074
4 min
UDPGA
Not available
Not available
0.25-10 µM
0.5-8 µM
17 . Inhibition of UGT1A1, 1A8, and 1A10 by (-)-Epicatechin Gallate (Screening) (id=NPDI-WhE0iA)
In Vitro Enzyme Inhibition Experiment
Inhibition was detected. Cutoff used — 50% inhibition vs. control
- UGT1A1 40782950
- UGT1A10
- UGT1A8
Cell fraction Pooled human intestinal microsomes -7999663
The precipitant used was (-)-epicatechin gallate. Information regarding enzymes involved in the formation of raloxifene metabolites was obtained from Gufford et al., 2015 (Drug Metab Dispos. 2015 Sep;43(9):1353-9).
Results
At 10 µM (-)-epicatechin gallate inhibited the formation of raloxifene 4'-glucuronide by about 65%. Percent inhibition values were estimated from Fig. S2.
| Sample | Compound measured | Value | Measurement | Study sequence | Additional information | N replicates |
|---|
Experimental Conditions
Commercially available
1410074
Not available
Not available
100 µM
Control Experiment Information
18 . Inhibition of UGT1A1, 1A8, and 1A10 by (-)-Epicatechin Gallate (Screening) (id=NPDI-Hzxkxw)
In Vitro Enzyme Inhibition Experiment
Inhibition was detected. Cutoff used — 50% inhibition vs. control
- UGT1A1 40782950
- UGT1A10
- UGT1A8
Cell fraction Pooled human intestinal microsomes -7999663
Information regarding enzymes involved in the formation of raloxifene metabolites was obtained from Gufford et al., 2015 (Drug Metab Dispos. 2015 Sep;43(9):1353-9).
Results
At 10 µM (-)-epicatechin gallate inhibited the formation of raloxifene 6-glucuronide by about 70%. Percent inhibition values were estimated from Fig. S2.
| Sample | Compound measured | Value | Measurement | Study sequence | Additional information | N replicates |
|---|
Experimental Conditions
Commercially available
1410074
Not available
Not available
100 µM
Control Experiment Information
19 . Inhibition of UGT1A1, 1A8, and 1A10 by (-)-Epicatechin Gallate (Ki determination) (id=NPDI-1nd-Ow)
In Vitro Enzyme Inhibition Experiment
Inhibition was detected. Cutoff used — Not provided
- UGT1A1 40782950
- UGT1A10
- UGT1A8
Cell fraction Pooled human intestinal microsomes -7999663
The precipitant used was (-)-epicatechin gallate. Information regarding enzymes involved in the formation of raloxifene metabolites was obtained from Gufford et al., 2015 (Drug Metab Dispos. 2015 Sep;43(9):1353-9).
Results
Using methods 1 and 2 provided by the authors, enterocyte concentrations for (-)-epicatechin gallate were estimated to be 8.5 and 0.29 µM, respectively, after administration of one bag of T21 green tea. With the Ki value of approximately 1 µM, the corresponding AUCi/AUC ratios were predicted to be 6.5 and 1.3, respectively.
| Sample | Compound measured | Value | Measurement | Study sequence | Additional information | N replicates |
|---|
Experimental Conditions
0.05 mg/mL
Commercially available
1410074
4 min
UDPGA
Not available
Not available
0.25-10 µM
0.5-8 µM
20 . Inhibition of UGT1A1 and 1A8 by Green Tea Leaf Extract (T21) (Ki determination) (id=NPDI-jljbXg)
In Vitro Enzyme Inhibition Experiment
Inhibition was detected. Cutoff used — Not provided.
- UGT1A1 40782950
- UGT1A8
Cell fraction Pooled human intestinal microsomes -7999663
Methanol extract of a widely avaliable commercial green tea leaf (T21, 200 mg) chemically similar to the National Institute of Standards and Technology (NIST) green tea leaf reference was used. Information regarding enzymes involved in the formation of raloxifene metabolites was obtained from Gufford et al., 2015 (Drug Metab Dispos. 2015 Sep;43(9):1353-9).
Results
| Sample | Compound measured | Value | Measurement | Study sequence | Additional information | N replicates |
|---|
Experimental Conditions
0.05 mg/mL
Commercially available
1410074
4 min
UDPGA
Not available
Not available
0.25-10 µM
2.5-40 µg/mL
21 . Inhibition of UGT1A1, 1A8, and 1A10 by Green Tea Leaf Extract (T21) (Ki determination) (id=NPDI-aqYl1g)
In Vitro Enzyme Inhibition Experiment
Inhibition was detected. Cutoff used — Not provided
- UGT1A1 40782950
- UGT1A10
- UGT1A8
Cell fraction Pooled human intestinal microsomes -7999663
Methanol extract of a widely avaliable commercial green tea leaf (T21, 200 mg) chemically similar to the National Institute of Standards and Technology (NIST) green tea leaf reference was used. Information regarding enzymes involved in the formation of raloxifene metabolites was obtained from Gufford et al., 2015 (Drug Metab Dispos. 2015 Sep;43(9):1353-9).
Results
| Sample | Compound measured | Value | Measurement | Study sequence | Additional information | N replicates |
|---|
Experimental Conditions
0.05 mg/mL
Commercially available
1410074
4 min
UDPGA
Not available
Not available
0.25-10 µM
2.5-40 µg/mL
22 . Inhibition of UGT by (-)-Epicatechin (Screening) (id=NPDI-cTDX2A)
In Vitro Enzyme Inhibition Experiment
Negligible Inhibition was detected. Cutoff used — 50% inhibition vs. control
- UGT
Cell fraction Pooled human intestinal microsomes -7999663
Results
(-)-Epicatechin did not significantly inhibit UGT enzymes--observed UGT activity was 110% of control.
| Sample | Compound measured | Value | Measurement | Study sequence | Additional information | N replicates |
|---|
Experimental Conditions
Purified green tea catechins were tested as inhibitors of UGT enzymes as described in Gufford et al., 2014 (Drug Metab Dispos. 2014 Oct;42(10):1675-83); information regarding incubation volume, time, and protien linearity were obtain therein.
Bovine serum albumin (0.05%) was added into the incubation system.
0.2 mg/mL
Commercially available
1410074
150 µL
20 min
UDPGA
Available
Not available
100 µM
100 µM
Control Experiment Information
23 . Inhibition of UGT by (-)-Gallocatechin (Screening) (id=NPDI-p3x0vg)
In Vitro Enzyme Inhibition Experiment
Negligible Inhibition was detected. Cutoff used — 50% inhibition vs. control
- UGT
Cell fraction Pooled human intestinal microsomes -7999663
Results
(-)-Gallocatechin did not significantly inhibit UGT enzymes--observed UGT activity was 105% of control.
| Sample | Compound measured | Value | Measurement | Study sequence | Additional information | N replicates |
|---|
Experimental Conditions
Purified green tea catechins were tested as inhibitors of UGT enzymes as described in Gufford et al., 2014 (Drug Metab Dispos. 2014 Oct;42(10):1675-83); information regarding incubation volume, time, and protien linearity were obtain therein.
Bovine serum albumin (0.05%) was added into the incubation system.
0.2 mg/mL
Commercially available
1410074
150 µL
20 min
UDPGA
Available
Not available
100 µM
100 µM
Control Experiment Information
24 . Inhibition of UGT by (-)-Epigallocatechin (Screening) (id=NPDI-7pd4sA)
In Vitro Enzyme Inhibition Experiment
Negligible Inhibition was detected. Cutoff used — 50% inhibition vs. control
- UGT
Cell fraction Pooled human intestinal microsomes -7999663
The precipitant used was (-)-epigallocatechin.
Results
(-)-Epigallocatechin did not significantly inhibit UGT enzymes--observed UGT activity was 110% of control.
| Sample | Compound measured | Value | Measurement | Study sequence | Additional information | N replicates |
|---|
Experimental Conditions
Purified green tea catechins were tested as inhibitors of UGT enzymes as described in Gufford et al., 2014 (Drug Metab Dispos. 2014 Oct;42(10):1675-83); information regarding incubation volume, time, and protien linearity were obtain therein.
Bovine serum albumin (0.05%) was added into the incubation system.
0.2 mg/mL
Commercially available
1410074
150 µL
20 min
UDPGA
Available
Not available
100 µM
100 µM