Recent Advances in Glycyrrhiza glabra (Licorice)-Containing Herbs Alleviating Radiotherapy- and Chemotherapy-Induced Adverse Reactions in Cancer Treatment

Cancers represent a significant cause of morbidity and mortality worldwide. They also impose a large economic burden on patients, their families, and health insurance systems. Notably, cancers and the adverse reactions to their therapeutic options, chemotherapy and radiotherapy, dramatically affect the quality of life of afflicted patients. Therefore, developing approaches to manage chemotherapy- and radiotherapy-induced adverse reactions gained greater attention in recent years. Glycyrrhiza glabra (licorice), a perennial plant that is one of the most frequently used herbs in traditional Chinese medicine, has been heavily investigated in relation to cancer therapy. Licorice/licorice-related regimes, used in combination with chemotherapy, may improve the adverse effects of chemotherapy. However, there is little awareness of licorice-containing herbs alleviating reactions to radiotherapy and chemotherapy, or to other induced adverse reactions in cancer treatment. We aimed to provide a descriptive review, and to emphasize the possibility that licorice-related medicines could be used as an adjuvant regimen with chemotherapy to improve quality of life (QoL) and to reduce side effects, thus, improving compliance with chemotherapy. The experimental method involved searching different databases, including PubMed, the Cochrane Library, and Wang Fang database, as of May 2022, to identify any relevant studies. Despite a lack of high-quality and large-scale randomized controlled trials, we still discovered the potential benefits of licorice-containing herbs from published clinical studies. These studies find that licorice-containing herbs, and their active ingredients, reduce the adverse reactions caused by chemotherapy and radiotherapy, and improve the QoL of patients. This comprehensive review will serve as a cornerstone to encourage more scientists to evaluate and develop effective Traditional Chinese medicine prescriptions to improve the side effects of chemotherapy and radiation therapy.

Glycyrrhiza glabra (Licorice): A Comprehensive Review on Its Phytochemistry, Biological Activities, Clinical Evidence and Toxicology

There are more than 30 species of Glycyrrhiza genus extensively spread worldwide. It was the most prescribed herb in Ancient Egyptian, Roman, Greek, East China, and the West from the Former Han era. There are various beneficial effects of licorice root extracts, such as treating throat infections, tuberculosis, respiratory, liver diseases, antibacterial, anti-inflammatory, and immunodeficiency. On the other hand, traditional medicines are getting the attraction to treat many diseases. Therefore, it is vital to screen the medicinal plants to find the potential of new compounds to treat chronic diseases such as respiratory, cardiovascular, anticancer, hepatoprotective, etc. This work comprehensively reviews ethnopharmacological uses, phytochemistry, biological activities, clinical evidence, and the toxicology of licorice, which will serve as a resource for future clinical and fundamental studies. An attempt has been made to establish the pharmacological effect of licorice in different diseases. In addition, the focus of this review article is on the molecular mechanism of licorice extracts and their four flavonoids (isoliquiritigenin, liquiritigenin, lichalocone, and glabridin) pharmacologic activities. Licorice could be a natural alternative for current therapy to exterminate new emerging disorders with mild side effects. This review will provide systematic insights into this ancient drug for further development and clinical use.

Characterization of multiple chemical components of GuiLingJi by UHPLC-MS and 1H NMR analysis

GuiLingJi (GLJ), a classic traditional Chinese medicine (TCM) formula, is composed of over 20 herbs, according to the Pharmacopeia of the People's Republic of China. Owing to its various activities, GLJ has been used in clinical settings for more than 400 years in China. However, the ambiguous chemical material basis limits the development of studies on the quality control and pharmacological mechanisms of GLJ. Therefore, comprehensive characterization of the multiple chemical components of GLJ is of great significance for the modernization of this formula. Given the great variety of herbs in GLJ, both UHPLC-MS and ¹H NMR techniques were employed in this study. In addition, solvent extraction with different polarities was used to eliminate signal interference and the concentration of trace components. A variety of MS analytic methods were also used, including implementation of a self-built compound database, diagnostic ion filtering, mass defect filtering, and Compound Discoverer 3.0 analysis software. Based on the above strategies, a total of 150 compounds were identified, including 5 amino acids, 13 phenolic acids and glycosides, 11 coumarins, 72 flavones, 20 triterpenoid and triterpenoid saponins, 23 fatty acids, and 6 other compounds. Moreover, 13 compounds were identified by ¹H NMR spectroscopy. The UHPLC-MS and ¹H NMR results supported and complemented each other. This strategy provides a rapid approach to analyzing and identifying the chemical composition of Chinese herbal prescriptions. The current study provides basis for further research on the quality control and pharmacological mechanism of GLJ.

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The integrated approach of UHPLC-MS and ¹H NMR techniques coupled with polarity partition strategy has been used for comprehensively characterizing the multiple chemical components of GLJ.

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A variety of HRMS analytic methods used included self-built compounds database, diagnostic ions filtering, mass defect filtering, and software analysis for rapid identification the chemical components of GLJ.

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The 163 compounds including flavones, phenolic acids and glycosides, triterpenoid and triterpenoid saponins, coumarin, fatty acids, amino acids, organic acids, organic bases and sugars were rapidly identified, and to clarify the chemical material basis of GLJ.

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Established an analysis strategy which could be applied to other TCM formula for comprehensive characterization and identification of chemical components.

Glycyrrhiza Genus: Enlightening Phytochemical Components for Pharmacological and Health-Promoting Abilities

The Glycyrrhiza genus, generally well-known as licorice, is broadly used for food and medicinal purposes around the globe. The genus encompasses a rich pool of bioactive molecules including triterpene saponins (e.g., glycyrrhizin) and flavonoids (e.g., liquiritigenin, liquiritin). This genus is being increasingly exploited for its biological effects such as antioxidant, antibacterial, antifungal, anti-inflammatory, antiproliferative, and cytotoxic activities. The species Glycyrrhiza glabra L. and the compound glycyrrhizin (glycyrrhizic acid) have been studied immensely for their effect on humans. The efficacy of the compound has been reported to be significantly higher on viral hepatitis and immune deficiency syndrome. This review provides up-to-date data on the most widely investigated Glycyrrhiza species for food and medicinal purposes, with special emphasis on secondary metabolites' composition and bioactive effects.

Recent advances in chemical analysis of licorice (Gan-Cao)

Gan-Cao, or licorice, the dried roots and rhizomes of Glycyrrhiza uralensis, G.glabra, and G.inflata, has received considerable interest due to its extensive application in traditional Chinese medicine (TCM) prescriptions (60% approximately), clinical therapy, and as food additives world-wide. Chemical analysis is an important approach to understand the active pharmaceutical components in licorice and its prescriptions, as well as to develop novel methodologies for their quality assessment and control. This comprehensive review describes the advances in the chemical analysis, including sample preparation methods, qualitative and quantitative analysis and biological specimen analysis, based on 113 references for the recent years. Newly established methods are summarized, such as high performance thin layer chromatography (HPTLC), high performance liquid chromatography (HPLC), liquid chromatography tandem mass spectrometry (LC-MS), capillary electrophoresis (CE) and near infrared spectroscopy (NIR), which allows the identification, authentication, and simultaneous detection of multiple compounds in licorice with higher throughput and sensitivity. It is anticipated that this review could provide imperative information for improving the existing quality evaluation methods of licorice and afford scientific basis for further researches on the pharmacodynamic substances of licorice.

Simultaneous Determination and Pharmacokinetic Characterization of Glycyrrhizin, Isoliquiritigenin, Liquiritigenin, and Liquiritin in Rat Plasma Following Oral Administration of Glycyrrhizae Radix Extract

Glycyrrhizae Radix is widely used as herbal medicine and is effective against inflammation, various cancers, and digestive disorders. We aimed to develop a sensitive and simultaneous analytical method for detecting glycyrrhizin, isoliquiritigenin, liquiritigenin, and liquiritin, the four marker components of Glycyrrhizae Radix extract (GRE), in rat plasma using liquid chromatography-tandem mass spectrometry and to apply this analytical method to pharmacokinetic studies. Retention times for glycyrrhizin, isoliquiritigenin, liquiritigenin, and liquiritin were 7.8 min, 4.1 min, 3.1 min, and 2.0 min, respectively, suggesting that the four analytes were well separated without any interfering peaks around the peak elution time. The lower limit of quantitation was 2 ng/mL for glycyrrhizin and 0.2 ng/mL for isoliquiritigenin, liquiritigenin, and liquiritin; the inter- and intra-day accuracy, precision, and stability were less than 15%. Plasma concentrations of glycyrrhizin, isoliquiritigenin, liquiritigenin, and liquiritin were quantified for 24 h after a single oral administration of 1 g/kg GRE to four rats. Among the four components, plasma concentration of glycyrrhizin was the highest and exhibited a long half-life (23.1 ± 15.5 h). Interestingly, plasma concentrations of isoliquiritigenin and liquiritigenin were restored to the initial concentration at 4–10 h after the GRE administration, as evidenced by liquiritin biotransformation into isoliquiritigenin and liquiritigenin, catalyzed by fecal lysate and gut wall enzymes. In conclusion, our analytical method developed for detecting glycyrrhizin, isoliquiritigenin, liquiritigenin, and liquiritin could be successfully applied to investigate their pharmacokinetic properties in rats and would be useful for conducting further studies on the efficacy, toxicity, and biopharmaceutics of GREs and their marker components.

Identification and Chemical Standardization of Licorice Raw Materials and Dietary Supplements Using UHPLC-MS/MS

Defined as the roots and underground stems of principally three Glycyrrhiza species, Glycyrrhiza glabra L., Glycyrrhiza uralensis Fish. ex DC., and Glycyrrhiza inflata Batalin, licorice has been used as a medicinal herb for millennia and is marketed as root sticks, powders, and extracts. Identity tests described in most pharmacopeial monographs enabled the distinction of Glycyrrhiza species. Accordingly, an ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) assay using the method of standard addition was developed to quantify 14 licorice components (liquiritin, isoliquiritin, liquiritin apioside, isoliquiritin apioside, licuraside, liquiritigenin, isoliquiritigenin, glycyrrhizin, glycyrrhetinic acid, glabridin, glycycoumarin, licoricidin, licochalcone A, and p-hydroxybenzylmalonic acid), representing several natural product classes including chalcones, flavanones, saponins, and isoflavonoids. Using this approach, G. glabra, G. uralensis, and G. inflata in a variety of forms including root powders and extracts as well as complex dietary supplements could be differentiated and chemically standardized without concerns due to matrix effects.