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Characterization of cardamonin metabolism by P450 in different species via HPLC-ESI-ion trap and UPLC-ESI-quadrupole mass spectrometry.

He YQ, Yang L, Liu Y, Zhang JW, Tang J, Su J, Li YY, Lu YL, Wang CH, Yang L, Wang ZT - Acta Pharmacol. Sin. (2009)

Bottom Line: Furafylline and clomethiazole significantly inhibited cardamonin hydroxylation.CYP 1A2 and 2E1 were identified as the P450 isozymes involved in the metabolism of cardamonin in human liver microsomes.Furthermore, our research suggests that guinea pigs could be used in the advanced pharmacokinetic studies of cardamonin in vivo.

View Article: PubMed Central - PubMed

Affiliation: The MOE Key Laboratory for Standardization of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201210, China.

ABSTRACT

Aim: To characterize the metabolism of cardamonin by the P450 enzymes in human and animal liver microsomes.

Methods: Cardamonin was incubated with both human and animal liver microsomal incubation systems containing P450 reaction factors. High performance liquid chromatography coupled with ion trap mass spectrometry was used to identify the metabolites. Serial cardamonin dilutions were used to perform a kinetic study in human liver microsomes. Selective inhibitors of 7 of the major P450 isozymes were used to inhibit cardamonin hydroxylation to identify the isozymes involved in cardamonin metabolism. The cardamonin hydroxylation metabolic capacities of human and various other animals were investigated using the liver microsomal incubation system.

Results: Two metabolites generated by the liver microsome system were detected and identified as hydroxylated cardamonin. The Km and Vmax values for cardamonin hydroxylation were calculated as 32 micromol/L and 35 pmol x min(-1) x mg(-1), respectively. Furafylline and clomethiazole significantly inhibited cardamonin hydroxylation. Guinea pigs showed the highest similarity to humans with respect to the metabolism of cardamonin.

Conclusion: CYP 1A2 and 2E1 were identified as the P450 isozymes involved in the metabolism of cardamonin in human liver microsomes. Furthermore, our research suggests that guinea pigs could be used in the advanced pharmacokinetic studies of cardamonin in vivo.

Show MeSH
Inhibition of cardamonin hydroxylation by various selective inhibitors of P450 isozymes. REA: remain enzyme activity.
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fig7: Inhibition of cardamonin hydroxylation by various selective inhibitors of P450 isozymes. REA: remain enzyme activity.

Mentions: The selective inhibitors of CYP 1A2, 2A6, 2C8, 2C9, 2D6, 2E1, and 3A4 were used to inhibit cardamonin hydroxylation. REA on cardamonin hydroxylation in each of the inhibited incubations was 16.14%, 73.97%, 55.88%, 63.53%, 80.41%, 13.99%, and 84.33% for CYP 1A2, 2A6, 2C8, 2C9, 2D6, 2E1, and 3A4, respectively (Figure 7). Results indicated that CYP 1A2 and 2E1 might play the most important roles during cardamonin hydroxylation. The inhibitory kinetics of cardamonin hydroxylation by furafylline and clomethiazole was analyzed. For furafylline, the trend lines of the Lineweaver-Burk plots at various inhibitor concentrations intersected the Y axis at the same plot (Figure 8A), which indicates that furafylline shows a competitive inhibition on cardamonin hydroxylation. For clomethiazole, the trend lines of the Lineweaver-Burk plots intersected the X axis at the same plot (Figure 8B), indicating that clomethiazole shows noncompetitive inhibition on cardamonin hydroxylation.


Characterization of cardamonin metabolism by P450 in different species via HPLC-ESI-ion trap and UPLC-ESI-quadrupole mass spectrometry.

He YQ, Yang L, Liu Y, Zhang JW, Tang J, Su J, Li YY, Lu YL, Wang CH, Yang L, Wang ZT - Acta Pharmacol. Sin. (2009)

Inhibition of cardamonin hydroxylation by various selective inhibitors of P450 isozymes. REA: remain enzyme activity.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4007323&req=5

fig7: Inhibition of cardamonin hydroxylation by various selective inhibitors of P450 isozymes. REA: remain enzyme activity.
Mentions: The selective inhibitors of CYP 1A2, 2A6, 2C8, 2C9, 2D6, 2E1, and 3A4 were used to inhibit cardamonin hydroxylation. REA on cardamonin hydroxylation in each of the inhibited incubations was 16.14%, 73.97%, 55.88%, 63.53%, 80.41%, 13.99%, and 84.33% for CYP 1A2, 2A6, 2C8, 2C9, 2D6, 2E1, and 3A4, respectively (Figure 7). Results indicated that CYP 1A2 and 2E1 might play the most important roles during cardamonin hydroxylation. The inhibitory kinetics of cardamonin hydroxylation by furafylline and clomethiazole was analyzed. For furafylline, the trend lines of the Lineweaver-Burk plots at various inhibitor concentrations intersected the Y axis at the same plot (Figure 8A), which indicates that furafylline shows a competitive inhibition on cardamonin hydroxylation. For clomethiazole, the trend lines of the Lineweaver-Burk plots intersected the X axis at the same plot (Figure 8B), indicating that clomethiazole shows noncompetitive inhibition on cardamonin hydroxylation.

Bottom Line: Furafylline and clomethiazole significantly inhibited cardamonin hydroxylation.CYP 1A2 and 2E1 were identified as the P450 isozymes involved in the metabolism of cardamonin in human liver microsomes.Furthermore, our research suggests that guinea pigs could be used in the advanced pharmacokinetic studies of cardamonin in vivo.

View Article: PubMed Central - PubMed

Affiliation: The MOE Key Laboratory for Standardization of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201210, China.

ABSTRACT

Aim: To characterize the metabolism of cardamonin by the P450 enzymes in human and animal liver microsomes.

Methods: Cardamonin was incubated with both human and animal liver microsomal incubation systems containing P450 reaction factors. High performance liquid chromatography coupled with ion trap mass spectrometry was used to identify the metabolites. Serial cardamonin dilutions were used to perform a kinetic study in human liver microsomes. Selective inhibitors of 7 of the major P450 isozymes were used to inhibit cardamonin hydroxylation to identify the isozymes involved in cardamonin metabolism. The cardamonin hydroxylation metabolic capacities of human and various other animals were investigated using the liver microsomal incubation system.

Results: Two metabolites generated by the liver microsome system were detected and identified as hydroxylated cardamonin. The Km and Vmax values for cardamonin hydroxylation were calculated as 32 micromol/L and 35 pmol x min(-1) x mg(-1), respectively. Furafylline and clomethiazole significantly inhibited cardamonin hydroxylation. Guinea pigs showed the highest similarity to humans with respect to the metabolism of cardamonin.

Conclusion: CYP 1A2 and 2E1 were identified as the P450 isozymes involved in the metabolism of cardamonin in human liver microsomes. Furthermore, our research suggests that guinea pigs could be used in the advanced pharmacokinetic studies of cardamonin in vivo.

Show MeSH