The Effects of the Honey-Roasting Process on the Pharmacokinetics of the Six Active Compounds of Licorice

Yulong Zhang,Jingyu Yang,Xiaobo Li,Mengyue Wang

doi:10.1155/2018/5731276

Abstract

A convenient UPLC-MS/MS method was established to determine the contents of six bioactive compounds, namely, liquiritin apioside, liquiritin, isoliquiritin, liquiritigenin, isoliquiritigenin, and glycyrrhetinic acid, in rat plasma and their pharmacokinetics. By comparing the pharmacokinetic parameters of these compounds in rats by orally administering raw and honey-roasting licorice, the Cmax of isoliquiritin showed a significant decrease, while the AUC0-24h showed no significant differences. The Cmax and AUC0-24h of isoliquiritigenin were increased by 49.3% and 42.7% over those of the raw licorice group, respectively. These results indicate that the absorption of isoliquiritin in rats was reduced while the absorption of isoliquiritigenin was promoted in the honey-roasting process. These results may provide one explanation as to why licorice is more able to relieve cough, while honey-roasting licorice is better at invigorating qi and restoring pulse. Furthermore, the Cmax of glycyrrhetinic acid was increased, suggesting that it may enhance the tonic effect of licorice. Additionally, the amount of honey added in the honey-roasting process influenced the pharmacokinetic parameters of the six compounds whose absorption decreased when the 50% honey-roasting licorice water decoction was administered. These results provide an experimental basis for studying the influence of licorice processing on bioactive compound pharmacokinetics.

Highlights

Licorice, Gancao in Chinese, is a commonly used traditional Chinese medicine (TCM) and is frequently divided into raw Gancao (Glycyrrhizae Radix et Rhizoma) and Zhi-gancao (Glycyrrhizae Radix et Rhizoma Praeparata Cum Melle) in TCM formularies
The uses of raw licorice could reinforce the function of the spleen, dispel phlegm, relieve cough, and moderate the properties of other herbs; Zhigancao is used to invigorate the functions of spleen and stomach as well as to reinforce qi and promote blood circulation [1]
liquiritin apioside (LA), LQ, ILQ, LG, ILG, and glycyrrhetinic acid (GA) were identified in rat plasma by UPLC-MS after oral administration of raw/honey-roasting licorice

Summary

Introduction

Gancao in Chinese, is a commonly used traditional Chinese medicine (TCM) and is frequently divided into raw Gancao (Glycyrrhizae Radix et Rhizoma) and Zhi-gancao (Glycyrrhizae Radix et Rhizoma Praeparata Cum Melle) in TCM formularies. Zhi-gancao is produced by a method in which raw Gancao is stir-fried with honey until it becomes yellow to deep yellow and not sticky and is cooled in the air [1]. The uses of raw licorice could reinforce the function of the spleen, dispel phlegm, relieve cough, and moderate the properties of other herbs; Zhigancao is used to invigorate the functions of spleen and stomach as well as to reinforce qi and promote blood circulation [1]. It was reported that honey-roasting licorice (Zhigancao) has better anti-inflammatory [2, 3], neuroprotective [4], and immunity-enhancing [5] properties than raw licorice. Glycyrrhetinic acid, a metabolic product of glycyrrhizic acid [10], was reported to have positive effects on the protection of rat hepatocytes [11] and the inhibition of inflammation [12]

Objectives

Methods

Results

Conclusion