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Inhibitory effects of phytochemicals on metabolic capabilities of CYP2D6(*)1 and CYP2D6(*)10 using cell-based models in vitro.

Qu Q, Qu J, Han L, Zhan M, Wu LX, Zhang YW, Zhang W, Zhou HH - Acta Pharmacol. Sin. (2014)

Bottom Line: Herbal products have been widely used, and the safety of herb-drug interactions has aroused intensive concerns.This study aimed to investigate the effects of phytochemicals on the catalytic activities of human CYP2D6(*)1 and CYP2D6(*)10 in vitro.HepG2-CYP2D6(*)1 and HepG2-CYP2D6(*)10 cell lines were successfully constructed.

View Article: PubMed Central - PubMed

Affiliation: 1] Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Xiangya Hospital, Central South University, Changsha 410078, China [2] Xiangya Hospital, Central South University, Changsha 410008, China.

ABSTRACT

Aim: Herbal products have been widely used, and the safety of herb-drug interactions has aroused intensive concerns. This study aimed to investigate the effects of phytochemicals on the catalytic activities of human CYP2D6(*)1 and CYP2D6(*)10 in vitro.

Methods: HepG2 cells were stably transfected with CYP2D6(*)1 and CYP2D6(*)10 expression vectors. The metabolic kinetics of the enzymes was studied using HPLC and fluorimetry.

Results: HepG2-CYP2D6(*)1 and HepG2-CYP2D6(*)10 cell lines were successfully constructed. Among the 63 phytochemicals screened, 6 compounds, including coptisine sulfate, bilobalide, schizandrin B, luteolin, schizandrin A and puerarin, at 100 μmol/L inhibited CYP2D6(*)1- and CYP2D6(*)10-mediated O-demethylation of a coumarin compound AMMC by more than 50%. Furthermore, the inhibition by these compounds was dose-dependent. Eadie-Hofstee plots demonstrated that these compounds competitively inhibited CYP2D6(*)1 and CYP2D6(*)10. However, their Ki values for CYP2D6(*)1 and CYP2D6(*)10 were very close, suggesting that genotype-dependent herb-drug inhibition was similar between the two variants.

Conclusion: Six phytochemicals inhibit CYP2D6(*)1 and CYP2D6(*)10-mediated catalytic activities in a dose-dependent manner in vitro. Thus herbal products containing these phytochemicals may inhibit the in vivo metabolism of co-administered drugs whose primary route of elimination is CYP2D6.

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Related in: MedlinePlus

Concentration-dependent effects of phytochemicals on CYP2D6*1 and *10-mediated AMMC-O-demethylation. HepG2-CYP2D6*1 (triangles) and *10 (closed circles) were incubated with various concentrations of the phytochemicals and 12 μmol/L AMMC. The metabolites were detected by fluorimetry as described in the Materials and methods section. AMMC in the absence of phytochemicals (0 μmol/L) was used as the control, HepG2-pcDNA3.1 was used as the blank, and data are represented as the percentage of the control, following the formula: (sample data–blank)/(control data–blank)×100%. The values are presented as the mean±SD of triplicate determinations in a single experiment.
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fig4: Concentration-dependent effects of phytochemicals on CYP2D6*1 and *10-mediated AMMC-O-demethylation. HepG2-CYP2D6*1 (triangles) and *10 (closed circles) were incubated with various concentrations of the phytochemicals and 12 μmol/L AMMC. The metabolites were detected by fluorimetry as described in the Materials and methods section. AMMC in the absence of phytochemicals (0 μmol/L) was used as the control, HepG2-pcDNA3.1 was used as the blank, and data are represented as the percentage of the control, following the formula: (sample data–blank)/(control data–blank)×100%. The values are presented as the mean±SD of triplicate determinations in a single experiment.

Mentions: To further confirm the hits from the initial screen, we investigated the concentration-dependent effects of the phytochemicals on CYP2D6*1 and *10-mediated AMMC-O-demethylation. As shown in Figure 4, the potent inhibitors, including bilobalide, coptisine sulfate, schizandrin B, luteolin, schizandrin A, and puerarin, inhibited the catalytic activity of CYP2D6*1 and *10 in a dose-dependent manner. However, the IC50 values for the CYP2D6*1 and *10 isoforms inhibited by these potent inhibitors were not different (Table 4). To determine the type of inhibition, the inhibition data were plotted on an Eadie-Hofstee plot. These data demonstrate that all phytochemicals tested competitively inhibit CYP2D6*1 and *10 (Figure 5). Ki values obtained from the CYP2D6*10 cells were slightly higher than those from the CYP2D6*1 cells, but the ratios of the Ki values (Ki value of CYP2D6*10/Ki value of CYP2D6*1) ranged from 1.05 to 1.30, which are lower than the Ki ratios for quinidine.


Inhibitory effects of phytochemicals on metabolic capabilities of CYP2D6(*)1 and CYP2D6(*)10 using cell-based models in vitro.

Qu Q, Qu J, Han L, Zhan M, Wu LX, Zhang YW, Zhang W, Zhou HH - Acta Pharmacol. Sin. (2014)

Concentration-dependent effects of phytochemicals on CYP2D6*1 and *10-mediated AMMC-O-demethylation. HepG2-CYP2D6*1 (triangles) and *10 (closed circles) were incubated with various concentrations of the phytochemicals and 12 μmol/L AMMC. The metabolites were detected by fluorimetry as described in the Materials and methods section. AMMC in the absence of phytochemicals (0 μmol/L) was used as the control, HepG2-pcDNA3.1 was used as the blank, and data are represented as the percentage of the control, following the formula: (sample data–blank)/(control data–blank)×100%. The values are presented as the mean±SD of triplicate determinations in a single experiment.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4814035&req=5

fig4: Concentration-dependent effects of phytochemicals on CYP2D6*1 and *10-mediated AMMC-O-demethylation. HepG2-CYP2D6*1 (triangles) and *10 (closed circles) were incubated with various concentrations of the phytochemicals and 12 μmol/L AMMC. The metabolites were detected by fluorimetry as described in the Materials and methods section. AMMC in the absence of phytochemicals (0 μmol/L) was used as the control, HepG2-pcDNA3.1 was used as the blank, and data are represented as the percentage of the control, following the formula: (sample data–blank)/(control data–blank)×100%. The values are presented as the mean±SD of triplicate determinations in a single experiment.
Mentions: To further confirm the hits from the initial screen, we investigated the concentration-dependent effects of the phytochemicals on CYP2D6*1 and *10-mediated AMMC-O-demethylation. As shown in Figure 4, the potent inhibitors, including bilobalide, coptisine sulfate, schizandrin B, luteolin, schizandrin A, and puerarin, inhibited the catalytic activity of CYP2D6*1 and *10 in a dose-dependent manner. However, the IC50 values for the CYP2D6*1 and *10 isoforms inhibited by these potent inhibitors were not different (Table 4). To determine the type of inhibition, the inhibition data were plotted on an Eadie-Hofstee plot. These data demonstrate that all phytochemicals tested competitively inhibit CYP2D6*1 and *10 (Figure 5). Ki values obtained from the CYP2D6*10 cells were slightly higher than those from the CYP2D6*1 cells, but the ratios of the Ki values (Ki value of CYP2D6*10/Ki value of CYP2D6*1) ranged from 1.05 to 1.30, which are lower than the Ki ratios for quinidine.

Bottom Line: Herbal products have been widely used, and the safety of herb-drug interactions has aroused intensive concerns.This study aimed to investigate the effects of phytochemicals on the catalytic activities of human CYP2D6(*)1 and CYP2D6(*)10 in vitro.HepG2-CYP2D6(*)1 and HepG2-CYP2D6(*)10 cell lines were successfully constructed.

View Article: PubMed Central - PubMed

Affiliation: 1] Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Xiangya Hospital, Central South University, Changsha 410078, China [2] Xiangya Hospital, Central South University, Changsha 410008, China.

ABSTRACT

Aim: Herbal products have been widely used, and the safety of herb-drug interactions has aroused intensive concerns. This study aimed to investigate the effects of phytochemicals on the catalytic activities of human CYP2D6(*)1 and CYP2D6(*)10 in vitro.

Methods: HepG2 cells were stably transfected with CYP2D6(*)1 and CYP2D6(*)10 expression vectors. The metabolic kinetics of the enzymes was studied using HPLC and fluorimetry.

Results: HepG2-CYP2D6(*)1 and HepG2-CYP2D6(*)10 cell lines were successfully constructed. Among the 63 phytochemicals screened, 6 compounds, including coptisine sulfate, bilobalide, schizandrin B, luteolin, schizandrin A and puerarin, at 100 μmol/L inhibited CYP2D6(*)1- and CYP2D6(*)10-mediated O-demethylation of a coumarin compound AMMC by more than 50%. Furthermore, the inhibition by these compounds was dose-dependent. Eadie-Hofstee plots demonstrated that these compounds competitively inhibited CYP2D6(*)1 and CYP2D6(*)10. However, their Ki values for CYP2D6(*)1 and CYP2D6(*)10 were very close, suggesting that genotype-dependent herb-drug inhibition was similar between the two variants.

Conclusion: Six phytochemicals inhibit CYP2D6(*)1 and CYP2D6(*)10-mediated catalytic activities in a dose-dependent manner in vitro. Thus herbal products containing these phytochemicals may inhibit the in vivo metabolism of co-administered drugs whose primary route of elimination is CYP2D6.

Show MeSH
Related in: MedlinePlus