Planta Med 2013; 79(06): 471-479
DOI: 10.1055/s-0032-1328332
Pharmacokinetic Investigations
Original Papers
Georg Thieme Verlag KG Stuttgart · New York

Hydrolysis Is the Dominating In Vivo Metabolism Pathway for Arctigenin: Identification of Novel Metabolites of Arctigenin by LC/MS/MS after Oral Administration in Rats

Authors

  • Qiong Gao

    1   School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR
  • Yufeng Zhang

    2   College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, PR China
  • Siukwan Wo

    1   School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR
  • Zhong Zuo

    1   School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR
Further Information

Publication History

received 10 October 2012
revised 06 January 2013

accepted 17 February 2013

Publication Date:
21 March 2013 (online)

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Abstract

The phenylpropanoid dibenzylbutyrolactone lignan arctigenin, a key component found in Arctium lappa, or burdock, has been reported with a variety of therapeutic effects including anticancer, anti-inflammation, and antivirus effects. Using LC/MS/MS, three novel metabolites of arctigenin, namely, arctigenic acid, arctigenin-4-O’-glucuronide, and 4-O-demethylarctigenin were identified after oral administration of arctigenin in rats for the first time. Another potential metabolite of arctigenin, arctigenin-4′-O-sulfate, was identified in vitro but not in vivo. Structure of arctigenic acid, the major metabolite of arctigenin, was confirmed by 13C-NMR and 1H-NMR. Rapid hydrolysis in plasma was identified as the major metabolic pathway of arctigenin after its oral administration, with Vmax, Km, and Clint in rat plasma determined to be 2.21 ± 0.12 nmol/min/mg, 89.12 ± 9.44 µM, and 24.74 µL/min/mg, respectively. Paraoxonase 1 was further confirmed to be the enzyme responsible for arctigenin hydrolysis, with Vmax, Km, and Clint determined to be 55.39 ± 1.49 nmol/min/mg, 300.3 ± 10.86 µM, and 184.45 µL/min/mg, respectively.