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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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(A) Structure of AMMC and the metabolite AMHC. (B) Chromatograms of the standard solution containing 10 ng/mL 1′-OH-bufuralol and structure of AMMC and the metabolite AMHC. (C) Time-dependent metabolism of AMMC by CYP2D6*1 and *10. AMMC (15 μmol/L) was incubated with HepG2-CYP2D6*1 or CYP2D6*10 in 96-well plates. The values are means±SD of triplicate determinations. (D) The metabolic kinetics of AMMC catalyzed by CYP2D6*1 and *10 were analyzed. The metabolic activities of AMMC at increasing concentrations were measured with HepG2-CYP2D6*1 (closed circles) or CYP2D6*10 (triangles) in 96-well plates. The values (mean±SD) were fitted to the Michaelis-Menten equation using non-linear regression analysis.
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fig2: (A) Structure of AMMC and the metabolite AMHC. (B) Chromatograms of the standard solution containing 10 ng/mL 1′-OH-bufuralol and structure of AMMC and the metabolite AMHC. (C) Time-dependent metabolism of AMMC by CYP2D6*1 and *10. AMMC (15 μmol/L) was incubated with HepG2-CYP2D6*1 or CYP2D6*10 in 96-well plates. The values are means±SD of triplicate determinations. (D) The metabolic kinetics of AMMC catalyzed by CYP2D6*1 and *10 were analyzed. The metabolic activities of AMMC at increasing concentrations were measured with HepG2-CYP2D6*1 (closed circles) or CYP2D6*10 (triangles) in 96-well plates. The values (mean±SD) were fitted to the Michaelis-Menten equation using non-linear regression analysis.

Mentions: AMMC is catalyzed by CYP2D6 to AMHC (Figure 2A), which can be detected by fluorimetry. In Figure 2B, the metabolite 1′-OH bufuralol was detected by HPLC. We detected the linearity of metabolite formation for a duration of 120 min. As shown in Figure 2C, the rates of AMMC-O-demethylation and bufuralol 1′-hydroxylation represent the activity of CYP2D6*1 and *10, which are linear with the incubation time. Thus, an incubation time of 90 min was utilized in all subsequent experiments.


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)

(A) Structure of AMMC and the metabolite AMHC. (B) Chromatograms of the standard solution containing 10 ng/mL 1′-OH-bufuralol and structure of AMMC and the metabolite AMHC. (C) Time-dependent metabolism of AMMC by CYP2D6*1 and *10. AMMC (15 μmol/L) was incubated with HepG2-CYP2D6*1 or CYP2D6*10 in 96-well plates. The values are means±SD of triplicate determinations. (D) The metabolic kinetics of AMMC catalyzed by CYP2D6*1 and *10 were analyzed. The metabolic activities of AMMC at increasing concentrations were measured with HepG2-CYP2D6*1 (closed circles) or CYP2D6*10 (triangles) in 96-well plates. The values (mean±SD) were fitted to the Michaelis-Menten equation using non-linear regression analysis.
© Copyright Policy
Related In: Results  -  Collection

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

fig2: (A) Structure of AMMC and the metabolite AMHC. (B) Chromatograms of the standard solution containing 10 ng/mL 1′-OH-bufuralol and structure of AMMC and the metabolite AMHC. (C) Time-dependent metabolism of AMMC by CYP2D6*1 and *10. AMMC (15 μmol/L) was incubated with HepG2-CYP2D6*1 or CYP2D6*10 in 96-well plates. The values are means±SD of triplicate determinations. (D) The metabolic kinetics of AMMC catalyzed by CYP2D6*1 and *10 were analyzed. The metabolic activities of AMMC at increasing concentrations were measured with HepG2-CYP2D6*1 (closed circles) or CYP2D6*10 (triangles) in 96-well plates. The values (mean±SD) were fitted to the Michaelis-Menten equation using non-linear regression analysis.
Mentions: AMMC is catalyzed by CYP2D6 to AMHC (Figure 2A), which can be detected by fluorimetry. In Figure 2B, the metabolite 1′-OH bufuralol was detected by HPLC. We detected the linearity of metabolite formation for a duration of 120 min. As shown in Figure 2C, the rates of AMMC-O-demethylation and bufuralol 1′-hydroxylation represent the activity of CYP2D6*1 and *10, which are linear with the incubation time. Thus, an incubation time of 90 min was utilized in all subsequent experiments.

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