Review of Constituents and Biological Activities of Triterpene Saponins from <i>Glycyrrhizae Radix</i> et Rhizoma and Its Solubilization Characteristics

• Main Authors: Feifei Li, Bin Liu, Tong Li, Qianwen Wu, Zhiyong Xu, Yuhao Gu, Wen Li, Penglong Wang, Tao Ma, Haimin Lei
• Format: Article
• Language: English
• Published: MDPI AG 2020-08-01
• Series: Molecules
• Subjects: <i>Glycyrrhizae Radix</i> et Rhizoma; triterpene saponins; glycyrrhizin; biological activities; solubilization
• Online Access: https://www.mdpi.com/1420-3049/25/17/3904

<i>Glycyrrhizae Radix</i> et Rhizoma is regarded as one of the most popular and commonly used herbal medicines and has been used in traditional Chinese medicine (TCM) prescriptions for over 2000 years. Pentacyclic triterpene saponins are common secondary metabolites in these plants, which are synthesized via the isoprenoid pathway to produce a hydrophobic triterpenoid aglycone containing a hydrophilic sugar chain. This paper systematically summarizes the chemical structures of triterpene saponins in <i>Glycyrrhizae Radix</i> et Rhizoma and reviews and updates their main biological activities studies. Furthermore, the solubilization characteristics, influences, and mechanisms of <i>Glycyrrhizae Radix</i> et Rhizoma are elaborated. Solubilization of the triterpene saponins from <i>Glycyrrhizae Radix</i> et Rhizoma occurs because they contain the nonpolar sapogenin and water-soluble sidechain. The possible factors affecting the solubilization of <i>Glycyrrhizae Radix</i> et Rhizoma are mainly other crude drugs and the pH of the decoction. Triterpene saponins represented by glycyrrhizin from <i>Glycyrrhizae Radix</i> et Rhizoma characteristically form micelles due to amphiphilicity, which makes solubilization possible. This overview provides guidance regarding a better understanding of <i>Glycyrrhizae</i><i>Radix</i> et Rhizoma and its TCM compatibility, alongside a theoretical basis for the further development and utilization of <i>Glycyrrhizae Radix</i> et Rhizoma.