Deglycosylation of Liquiritin Strongly Enhances its Inhibitory Potential Towards UDP‐Glucuronosyltransferase (UGT) Isoforms. (15th October 2012)

• Record Type: Journal Article
• Authors: Guo, Bin; Fan, Xu‐Ran; Fang, Zhong‐Ze; Cao, Yun‐Feng; Hu, Cui‐Min; Yang, Julin; Zhang, Yan‐Yan; He, Rong‐Rong; Zhu, Xu; Yu, Zhen‐Wen; Sun, Xiao‐Yu; Hong, Mo; Yang, Lu
• Is Part Of: Phytotherapy research. Volume 27:Number 8(2013:Aug.)
• Page Start: 1232
• Page End: 1236
• Publication Date: 2012-10-15
• Subjects: Materia medica, Vegetable -- Periodicals; Botany, Medical -- Periodicals; Medicinal plants -- Periodicals; Plant Extracts -- therapeutic use -- Periodicals; Plants, Medicinal -- Periodicals; 581.634
• DOI: 10.1002/ptr.4855
• Languages: English
• ISSNs: 0951-418X

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>The detailed mechanisms on licorice–drug interaction remain to be unclear. The aim of the present study is to investigate the inhibition of important UGT isoforms by two important ingredients of licorice, liquiritin, and liquiritigenin. The results showed that liquiritigenin exhibited stronger inhibition towards all the tested UGT isoforms than liquiritin. Data fitting using Dixon and Lineweaver–Burk plots demonstrated the competitive inhibition of liquiritigenin towards UGT1A1 and UGT1A9‐mediated 4‐MU glucuronidation reaction. The inhibition kinetic parameters (K_i) were calculated to be 9.1 and 3.2 μM for UGT1A1 and UGT1A9, respectively. Substrate‐dependent inhibition behaviour was also observed for UGT1A1 in the present study. All these results will be helpful for understanding the deep mechanism of licorice–drug interaction. However, when translating these <italic>in vitro</italic> parameters into <italic>in vivo</italic> situations, more complex factors should be considered, such as substrate‐dependent inhibition of UGT isoforms, the contribution of UGT1A1 and UGT1A9 towards the metabolism of drugs, and many factors affecting the abundance of ingredients in the licorice. Copyright © 2012 John Wiley &amp; Sons, Ltd.</p> </abstract>