Planta Med 2008; 74(12): 1474-1480
DOI: 10.1055/s-2008-1081351
Natural Products Chemistry
Original Paper
© Georg Thieme Verlag KG Stuttgart · New York

In Vitro Mechanism-Based Inactivation of Cytochrome P450 3A4 by a New Constituent of Cinnamomum burmani

Subehan Subehan1 , Shigetoshi Kadota1 , Yasuhiro Tezuka1 , 2
  • 1Institute of Natural Medicine, University of Toyama, Toyama, Japan
  • 221stCentury COE Program, University of Toyama, Toyama, Japan
Further Information

Publication History

Received: Februay 25, 2008 Revised: July 3, 2008

Accepted: July 7, 2008

Publication Date:
09 September 2008 (online)

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Abstract

Cytochrome P450 enzymes play an important role in drug metabolism. Various studies have reported the potential inhibition of these enzymes by natural compounds, leading to possible drug-herb interaction. One study reported that the MeOH extract of Cinnamomum burmani inhibited CYP3A4 in a mechanism-based mode. Further phytochemical investigation on this plant led to the isolation of 17 compounds including 2 new compounds: cinnamic aldehyde cyclic syringylglycerol 1,3-acetal (1) and 5′-hydroxy-5-hydroxymethyl-4′′,5′′-methylenedioxy-1,2,3,4-dibenzo-1,3,5-cycloheptatriene (2). The isolated constituents were tested for their preincubation time-dependent inhibition of CYP3A4 at 0 and 20 min. Only the new compound 2 showed an increase in the inhibitory activity to >50 % after 20-min preincubation. Further investigations of the inactivation by 2 displayed characteristics of a mechanism-based inactivator, with K I and k inact values of 7.7 μM and 0.04 min−1, respectively.

References

Dr. Yasuhiro Tezuka

Institute of Natural Medicine

University of Toyama

2630-Sugitani

Toyama 930–0194

Japan

Phone: +81-76-434-7627

Fax: +81-76-434-5059

Email: tezuka@inm.u-toyama.ac.jp