Acta Pharmacologica Sinica (2009) 30: 1462–1470; doi: 10.1038/aps.2009.127

Acta Pharmacologica Sinica (2009) 30: 1462–1470; doi: 10.1038/aps.2009.127; published online 21 Sep 2009

Original Article

Characterization of cardamonin metabolism by P 450 in different species via HPLC-ESI-ion trap and UPLC-ESI-quadrupole mass spectrometry

Yu-qi HE¹, Li YANG¹, Yong LIU², Jiang-wei ZHANG², Jun TANG³, Juan SU¹, Yuan-yuan LI¹, Yan-liu LU¹, Chang-hong WANG¹, Ling YANG^2,*, Zheng-tao WANG^1,*

¹The MOE Key Laboratory for Standardization of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201210, China; ²Laboratory of Pharmaceutical Resource Discovery, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China; ³College of Pharmacy, Wuhan University, Wuhan 430072, China

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 K_m and V_max values for cardamonin hydroxylation were calculated as 32 μmol/L and 35 pmol·min^-1·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 1A 2 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.

Keywords: cardamonin; metabolism; P450; human liver microsome; species difference

This work was partially supported by grants from the National Natural Science Foundation of China (No 30530840, 30772608), Key Project of Chinese National Programs for Fundamental Research and Development (973 Program, No 2006CB504704) and Shanghai Science & Technology Development Foundation (No 04DZ19851), the Greeting Fund of Dalian Institute of Chemical Physics, Chinese Academy of Science (No K 2006A 23).

* To whom correspondence should be addressed.
E-mail wangzht@hotmail.com (Zheng-tao WANG); yling@dicp.ac.cn (Ling YANG)
Received 2009-04-05 Accepted 2009-07-16

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