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

Zishen Qingre Lishi Huayu Recipe May Ameliorate the Symptoms of PCOS Model Rats via Alleviating Systemic and Ovarian Inflammation

BACKGROUND

Zishen Qingre Lishi Huayu recipe (ZQLHR) has shown significant therapeutic effects in treating sex hormone levels and follicular developmental disorders in patients with polycystic ovary syndrome (PCOS). However, little is known about the potential mechanisms of its treatment.

METHODS

Dehydroepiandrosterone and a high-fat diet induced the PCOS model rat. The serum of rats was collected to detect the levels of sex hormones and inflammatory cytokines by enzyme-linked immunosorbent assay, and the ovaries were collected for ovarian histopathology and qPCR assay to detect the levels of inflammatory cytokines in ovarian tissues. Granulosa cells (GCs) were collected for western blot assay to detect of IL-1β, IL-6R, and LOX protein expression levels.

RESULTS

ZQLHR could reduce body weight, regulate estrous cycles, and improve serum sex hormone levels, follicular development, and insulin resistance (IR) in PCOS model rats. In addition, ZQLHR treatment improved the levels of inflammatory cytokines in serum and ovary, and regulated the protein expression of IL-6R, IL-1β, and LOX in GCs of PCOS model rats. The results showed that the HOMA-IR index increased with the increasing levels of IL-6, IL-1β, and CRP, and decreased with the increased IL-10.

CONCLUSION

This study reveals that the treatment of endocrine disorders and ovulation disorders in PCOS with ZQLHR may be closely related to the improvement of systemic and ovarian inflammation in PCOS patients, as well as the inhibition of IL-6R, IL-1β, and LOX expression in GCs, which reemphasizes the role of reducing chronic inflammatory states in the treatment of PCOS. Moreover, this study reemphasizes the correlation between multiple inflammatory mediators and IR.

Exploring the effective components of honey-processed licorice (Glycyrrhiza uralensis Fisch.) in attenuating Doxorubicin-induced myocardial cytotoxicity by combining network pharmacology and in vitro experiments

ETHNOPHARMACOLOGICAL RELEVANCE

Licorice is widely used clinically as one of the most famous traditional Chinese herbs. Its herb roasted with honey is called honey-processed licorice (HPL). Modern studies have shown that HPL has a stronger cardioprotective ability compared to raw licorice (RL), however the material basis and mechanism of action of the potential cardioprotection have not been fully elucidated.

AIM OF THE STUDY

To screen and validate the material basis of cardioprotection exerted by HPL and to preliminarily predict the potential mechanism of action.

MATERIALS AND METHODS

UPLC-QTOF-MS/MS was used to analyze HPL samples with different processing levels, and differential compounds were screened out through principal component analysis. Network pharmacology and molecular docking were applied to explore the association between differential compounds and doxorubicin cardiomyopathy and their mechanisms of action were predicted. An in vitro model was established to verify the cardioprotective effects of differential compounds.

RESULTS

Six differential compounds were screened as key components of HPL for potential cardioprotection. Based on network pharmacology, 113 potential important targets for the treatment of Dox-induced cardiotoxicity were screened. KEGG enrichment analysis predicted that the PI3K-Akt pathway was closely related to the mechanism of action of active ingredients. Molecular docking results showed that the six differential compounds all had good binding activity with Nrf2 protein. In addition, in vitro experiments had shown that five of the active ingredients (liquiritin, isoliquiritin, liquiritigenin, isoliquiritigenin, and licochalcone A) can significantly increase Dox-induced H9c2 cell viability, SOD activity, and mitochondrial membrane potential, significantly reduces MDA levels and inhibits ROS generation.

CONCLUSION

Liquiritin, isoliquiritin, liquiritigenin, isoliquiritigenin and licochalcone A are key components of HPL with potential cardioprotective capabilities. Five active ingredients can alleviate Dox-induced cardiotoxicity by inhibiting oxidative stress and mitochondrial damage.

Three-dimensional fluorescence combined with alternating trilinear decomposition and random forest algorithm for the rapid prediction of species, geographical origin and main components of Glycyrrhizae Radix et Rhizoma (Gancao)

Glycyrrhizae Radix et Rhizoma (Gancao) is a functional food whose quality varies significantly between distinct geographical sources owing to the influence of genetics and the geographical environment. This study employed three-dimensional fluorescence coupled with alternating trilinear decomposition (ATLD) and random forest (RF) algorithms to rapidly predict Gancao species, geographical origins, and primary constituents. Seven fluorescent components were resolved from the three-dimensional fluorescence of the ATLD for subsequent analysis. Results indicated that the RF model distinguished Gancao from various species and origins better than other algorithms, achieving an accuracy of 94.4 % and 88.9 %, respectively. Furthermore, the RF regressor algorithm was used to predict the concentrations of liquiritin and glycyrrhizic acid in Gancao, with 96.4 % and 95.6 % prediction accuracies compared to HPLC, respectively. This approach offers a novel means of objectively evaluating the origin of food and holds substantial promise for food quality assessment.

Several major herb pairs containing Coptidis rhizoma: a review of key traditional uses, constituents and compatibility effects

Herb compatibility is the soul of traditional Chinese Medicine prescriptions. Coptidis rhizoma (CR) (Coptis chinensis Franch., Coptis deltoidea C.Y.Cheng et Hsiao, or Coptis teeta Wall.; family Ranunculaceae), is a well-known herb. The bitter and cold nature of CR can irritate the spleen and stomach, and certain ingredients in CR may trigger allergic reactions. Herb combinations can help alleviate the side effects caused by CR. Through data analysis and literature research, there are many herbs combined with CR have a high frequency, but only a few are currently used as formulae in clinical practice. The results showed that these six herb pairs are usually widely studied or used as prescriptions in the clinic. This paper describes the six herb pairs from the key traditional uses, changes in bioactive constituents, and compatibility effects, especially with Euodiae fructus (family Rutaceae), Scutellariae radix (family Lamiaceae), Magnoliae Officinalis cortex (family Magnoliaceae), Glycyrrhizae radix et rhizoma (family Fabaceae), Ginseng radix et rhizoma (family Araliaceae), and Aucklandiae radix (family Asteraceae), and found that herbs are more effective when used in combination. Therefore, it is feasible to establish some methods to study herb pairs comprehensively from different perspectives. This paper aims to provide the latest and most comprehensive information on the six herb pairs and summarize the pattern of CR compatibility effects. It aims to attract more attention, and further experimental studies will be conducted to investigate and evaluate the effects of herb pairs containing CR. These data can also provide valuable references for researchers and also provide more possibilities for future applications in clinical practice and new drug development.

Qualitative and Quantitative Analysis of Chemical Components in Yinhua Pinggan Granule with High-Performance Liquid Chromatography Coupled with Q-Exactive Mass Spectrometry

Yinhua Pinggan Granule (YPG) is an approved compounded traditional Chinese medicine (TCM) prescription for the treatment of cold, cough, viral pneumonia, and related diseases. Due to its complicated chemical composition, the material basis of YPG has not been systematically investigated. In this study, an analytical method based on high-performance liquid chromatography (HPLC) coupled with Q-Exactive mass spectrometry was established. Together with the help of a self-built compound database and Compound Discoverer software 3.1, the chemical components in YPG were tentatively identified. Subsequently, six main components in YPG were quantitatively characterized with a high-performance liquid chromatography-diode array detector (HPLC-DAD) method. As a result, 380 components were annotated, including 19 alkaloids, 8 organic acids, 36 phenolic acids, 27 other phenols, 114 flavonoids, 75 flavonoid glycoside, 72 terpenes, 11 anthraquinones, and 18 other compounds. Six main components, namely, chlorogenic acid, puerarin, 3'-methoxypuerarin, polydatin, glycyrrhizic acid, and emodin, were quantified simultaneously. The calibration curves of all six analytes showed good linearity (R2 > 0.9990) within the test ranges. The precision, repeatability, stability, and recovery values were all in acceptable ranges. In addition, the total phenol content and DPPH scavenging activity of YPG were also determined. The systematic elucidation of the chemical components in YPG in this study may provide clear chemical information for the quality control and pharmacological research of YPG and related TCM compounded prescriptions.

β-Cyclodextrin-assisted mechanical inclusion extraction of lipophilic flavonoids and hydrophilic terpenoids from functional food

This study presents an innovative, efficient, environmentally friendly and rapid mechanical inclusion extraction (MIE) method for active ingredients in functional food. 2-hydroxypropyl-beta-cyclodextrin was used as the inclusion reagent, and water was used as the extraction solvent in MIE. The experimental parameters affecting the extraction efficiency of the target compounds were systematically investigated using single-factor experiments and surface response methodology optimization. The method showed satisfactory linearity (coefficient of determination > 0.991), precision (0.02 % to 4.89 %), limit of detection (1.1-11.3 ng/mL), and recoveries of 80.4-108.7 % and 86.3-112.3 % at spiked concentration levels of 1 and 5 μg/mL, respectively. Consequently, the MIE method provided a novel green alternative and extended its applications for the simultaneous extraction of hydrophobic and hydrophilic compounds from functional food.

LicochalconeB inhibits cGAS-STING signaling pathway and prevents autoimmunity diseases

Cytosolic DNA activates the STING (stimulator of interferon genes) signaling pathway to trigger interferon and inflammatory responses that protect against microbial infections and cancer. However, Aicardi-Goutières syndrome (AGS) persistently activates the STING signaling pathway, which can lead to severe autoimmune diseases. We demonstrate herein that Licochalcone B (LicoB), the main component of traditional licorice, is an inhibitor of the STING signaling pathway. We observed that LicoB inhibited the activation of the STING signaling pathway in macrophages. Mechanically, LicoB affected the STING-TBK1-IRF3 signal axis and inhibited the activation of the STING downstream signaling pathway. Furthermore, LicoB inhibited the increase in type I interferon levels in mice induced by the STING agonist CMA. LicoB significantly reduced systemic inflammation in Trex1-/- mice. Our results show that LicoB, a STING signaling pathway inhibitor, is a promising candidate for the treatment of diseases related to STING signaling pathway activation.

Pingchong Jiangni recipe through nerve growth factor/transient receptor potential vanilloid 1 signaling pathway to relieve pain in endometriosis model rats

ETHNOPHARMACOLOGICAL RELEVANCE

Pingchong Jiangni recipe (PJR) is often used in the treatment of endometriosis (EM). This formula has been clinically validated by the State Administration of Traditional Chinese Medicine Key Specialties Collaborative Group for its therapeutic efficacy. Recently, our research team also confirmed that PJR has a shrinking effect on ovarian chocolate cysts. Additionally, PJR was also found to have a shrinking effect on EM lesions; however, the mechanism by which this effect occurs remains unclear.

AIM OF THE STUDY

To explore the mechanisms by which PJR relieves pain in patients with EM.

MATERIALS AND METHODS

A rat model of EM was established by autologous transplantation. PJR (3.78 g/kg, 7.56 g/kg, and 15.12 g/kg) was orally administered for 21 days. The rat grimace scale (RGS) score and paw withdrawal threshold (PWT) were measured at a fixed time during the experiment. Hematoxylin and eosin staining was performed to observe histopathological changes in EM rats after administration, enzyme-linked immunosorbent assay to evaluate the plasma expression of tumor necrosis factor-α (TNF-α) and nerve growth factor (NGF), and immunohistochemistry and western blotting to identify differences in the expression of pain-related factors in EM rats.

RESULTS

The medium-dose group of PJR (7.56 g/kg) had the best effect on relieving pain in EM rats by reducing RGS, increasing PWT, reducing the ectopic endometrium, improving the cellular structure of the lesion, and reducing TNF-α and NGF levels. However, PJR significantly decreased the expression of transient receptor potential vanilloid 1 (TRPV1), phosphorylated TRPV1 (p-TRPV1), protein kinase C (PKC), and NGF.

CONCLUSION

The mechanism by which PJR relieves EM pain may be through the downregulation of NGF, PKC, and TRPV1 expression.

From Nature to Innovation: The Uncharted Potential of Natural Deep Eutectic Solvents

This review discusses the significance of natural deep eutectic solvents (NaDESs) as a promising green extraction technology. It employs the consolidated meta-analytic approach theory methodology, using the Web of Science and Scopus databases to analyze 2091 articles as the basis of the review. This review explores NaDESs by examining their properties, challenges, and limitations. It underscores the broad applications of NaDESs, some of which remain unexplored, with a focus on their roles as solvents and preservatives. NaDESs' connections with nanocarriers and their use in the food, cosmetics, and pharmaceutical sectors are highlighted. This article suggests that biomimicry could inspire researchers to develop technologies that are less harmful to the human body by emulating natural processes. This approach challenges the notion that green science is inferior. This review presents numerous successful studies and applications of NaDESs, concluding that they represent a viable and promising avenue for research in the field of green chemistry.

Discovery, traceability, formation mechanism, metal and organic components analysis of supramolecules from Maxing Shigan decoction

Traditional Chinese medicine (TCM) decoction is a complex polydispersed phase system containing colloid solution, emulsion and suspension, which maybe induced by the supramolecular phenomenon in decoction. However, until now there is no systematic analysis of composition and formation mechanism of supramolecules in TCM decoction contained mineral drug and herb medicines. Maxing Shigan Decoction (MXSGT), one of the classic TCM recipes, has been widely used in the treatment of fever in clinic. In this study, we obtained the supramolecular part of MXSGT (MXSGT NPs). And its traceability, formation mechanism, metal and organic components were further analyzed. The morphology was characterized by scanning electron microscopy (SEM) and dynamic light scattering (DLS); and the lipopolysaccharides (LPS) induced rats' fever model was established to evaluate the antipyretic effect of MXSGT NPs. Furthermore, interaction of the disassembled groups was studied to explore the traceability and formation mechanism of MXSGT NPs by isothermal titration calorimeter (ITC). Due to the combination of mineral gypsum and herb medicines, both ICP-OES and UHPLC-Q-Orbitrap HRMS were used to analyze metal and organic components of MXSGT and MXSGT NPs, respectively. The results showed that MXSGT NPs was regular spherical nanoparticles and had the same antipyretic effect as MXSGT. Moreover, MXSGT NPs was formed by the interaction between metal and organic components, resulted in enriching the main active compounds of MXSGT. This study would provide a new idea of studying TCM decoction, especially clarifying the connotation with the participation of mineral gypsum.

[Adverse effects of licorice consumed as food: An update]

The word "licorice" refers to the plant, its root, and its aromatic extract. From a commercial point of view, Glycyrrhiza glabra is the most important species with a wide range of uses (herbal medicine, tobacco industry, cosmetics, food and pharmaceutical). Glycyrrhizin is one of the main constituents of licorice. Glycyrrhizin is hydrolyzed in the intestinal lumen by bacterial β-glucuronidases to 3β-monoglucuronyl-18β-glycyrrhetinic acid (3MGA) and 18β-glycyrrhetinic acid (GA), which are metabolized in the liver. Plasma clearance is slow due to enterohepatic cycling. 3MGA and GA can bind to mineralocorticoid receptors with very low affinity, and 3MGA induces apparent mineralocorticoid excess syndrome through dose-dependent inhibition of 11β-hydroxysteroid dehydrogenase type 2 in renal tissue. The cases of apparent mineralocorticoid excess syndrome reported in the literature are numerous and sometimes severe, even fatal, most often in cases of chronic high dose consumption. Glycyrrhizin poisonings are characterized by hypertension, fluid retention, and hypokalemia with metabolic alkalosis and increased kaliuresis. Toxicity depends on the dose, the type of product consumed, the mode of consumption (acute or chronic) and a very large inter-individual variability. The diagnosis of glycyrrhizin-induced apparent mineralocorticoid excess syndrome is based on the history, clinical examination, and biochemical analysis. Management is primarily based on symptomatic care and stopping licorice consumption.

Metagenomics insights into responses of rhizobacteria and their alleviation role in licorice allelopathy

BACKGROUND

Allelopathy is closely associated with rhizosphere biological processes, and rhizosphere microbial communities are essential for plant development. However, our understanding of rhizobacterial communities under influence of allelochemicals in licorice remains limited. In the present study, the responses and effects of rhizobacterial communities on licorice allelopathy were investigated using a combination of multi-omics sequencing and pot experiments, under allelochemical addition and rhizobacterial inoculation treatments.

RESULTS

Here, we demonstrated that exogenous glycyrrhizin inhibits licorice development, and reshapes and enriches specific rhizobacteria and corresponding functions related to glycyrrhizin degradation. Moreover, the Novosphingobium genus accounted for a relatively high proportion of the enriched taxa and appeared in metagenomic assembly genomes. We further characterized the different capacities of single and synthetic inoculants to degrade glycyrrhizin and elucidated their distinct potency for alleviating licorice allelopathy. Notably, the single replenished N (Novosphingobium resinovorum) inoculant had the greatest allelopathy alleviation effects in licorice seedlings.

CONCLUSIONS

Altogether, the findings highlight that exogenous glycyrrhizin simulates the allelopathic autotoxicity effects of licorice, and indigenous single rhizobacteria had greater effects than synthetic inoculants in protecting licorice growth from allelopathy. The results of the present study enhance our understanding of rhizobacterial community dynamics during licorice allelopathy, with potential implications for resolving continuous cropping obstacle in medicinal plant agriculture using rhizobacterial biofertilizers. Video Abstract.

Wide identification of chemical constituents in fermented licorice and explore its efficacy of anti-neurodegeneration by combining quasi-targeted metabolomics and in-depth bioinformatics

Licorice (Gan-Cao in Chinese) is one of the most famous herbal medicines around the world. The fermentation of probiotics and herbs can change the chemical constituents and significantly improve the efficacy. However, it is still unknown whether licorice fermented with probiotics would produce beneficial therapeutic effects. This study aimed to comprehensively analyze the chemical constituents in fermented licorice via quasi-targeted metabolomics, predict the potential efficacy of fermentation products via diverse bioinformatic methods, and further verify the efficacy of fermentation products through in vitro and in vivo experiments. As a result, 1,435 compounds were identified totally. Among them, 424 natural medicinal products were classified with potentially important bioactivities, including 11 anthocyanins, 10 chalcones and dihydrochalcones, 25 flavanones, 45 flavones and flavonols, 117 flavonoids, 34 isoflavonoids, 21 phenols and its derivatives, 20 phenylpropanoids and polyketides, 96 terpenoids and 25 coumarins and derivatives. Interestingly, bioinformatic prediction showed that the targets of some important compounds were related to neurodegeneration, oxidoreductase activity and response to stress. In vitro and in vivo tests further verified that fermented licorice had excellent effects of DPPH clearance, anti-oxidation, anti-neurodegeneration, and anti-stress. Thus, this study would provide a reference method for related research and the development of fermented licorice-related products.

Glycyrrhizae Radix et Rhizoma: The popular occurrence of herbal medicine applied in classical prescriptions

Glycyrrhizae Radix et Rhizoma is a well-known herbal medicine with a wide range of pharmacological functions that has been used throughout Chinese history. This review presents a comprehensive introduction to this herb and its classical prescriptions. The article discusses the resources and distribution of species, methods of authentication and determination chemical composition, quality control of the original plants and herbal medicines, dosages use, common classical prescriptions, indications, and relevant mechanisms of the active content. Pharmacokinetic parameters, toxicity tests, clinical trials, and patent applications are discussed. The review will provide a good starting point for the research and development of classical prescriptions to develop herbal medicines for clinical use.

The correlation between pharmacological activity and contents of eight constituents of Glycyrrhiza uralensis Fisch

Licorice (Glycyrrhiza uralensis Fisch. (GUF), Leguminosae) has been extensively applied in traditional Chinese medicine (TCM) to treat diseases, exactly, in almost half of Chinese herbal prescription. However, the relationship between chemical contents and efficacy has not been established, which could evaluate GUF quality. To create a simple and effective quality-evaluation method, 33 batches of GUF from different habitats in China were collected. The correlation between eight constituents (liquiritin, isoliquiritin, liquiritigenin, isoliquiritigenin, glycyrrhizic acid, licochalcone A, glabridin and glycyrrhetinic acid) and pharmacological activities (anti-inflammatory, antioxidant and immunoregulatory) was analyzed per the partial least squares regression method. Results showed that eight constituents correlated significantly with the pharmacological activity. The correlation equation modes between pharmacological activity and contents of eight constituents were constructed and verified to be reliable. In GUF extract, the main constituents liquiritin, isoliquiritin and glycyrrhizic acid exhibited positive influence on anti-inflammatory and antioxidant effect with different potent, while the metabolites liquiritigenin and isoliquiritigenin exhibited positive effect on the immunoregulatory activity and glycyrrhetinic acid exhibited positive effect on all the tested activities. Thus, our chemical-efficacy correlation method is reliable and feasible to predict the pharmacological activity based on its eight constituents. It could be powerful in quality control of GUF and provides a useful way for quality evaluation of other medicinal herbs.

Radix Glycyrrhizae extract and licochalcone a exert an anti-inflammatory action by direct suppression of toll like receptor 4

ETHNOPHARMACOLOGICAL RELEVANCE

Radix Glycyrrhizae (GL), a herbal medicine that is widely available, has shown advantages for a variety of inflammatory diseases. Toll like receptor 4 (TLR4) pathway has been shown to play a key role in the progression of inflammation.

AIM OF THE STUDY

The purpose of this study was to investigate the involvement of TLR4 in the anti-inflammatory mechanism of GL extract and its active constituent on acute lung injury (ALI).

MATERIALS AND METHODS

A model of inflammation produced by lipopolysaccharide (LPS) was established in C57BL/6 mice and macrophages derived from THP-1. To screen the active components of GL, molecular docking was used. Molecular dynamics and surface plasmon resonance imaging (SPRi) were used to study the interaction of a specific drug with the TLR4-MD2 complex. TLR4 was overexpressed by adenovirus to confirm TLR4 involvement in the anti-inflammatory activities of GL and the chosen chemical.

RESULTS

We observed that GL extract significantly reduced both LPS-induced ALI and the production of pro-inflammatory factors including TNF-α, IL-6 and IL-1β. Additionally, GL inhibited the binding of Alexa 488-labeled LPS (LPS-488) to the membrane of THP-1 derived macrophages. GL drastically reduce on the expression of TLR4 and the activation of mitogen-activated protein kinases (MAPKs) and nuclear factor-B (NF-κB). Furthermore, molecular docking revealed that Licochalcone A (LicoA) docked into the LPS binding site of TLR4-MD2 complex. MD2-LicoA binding conformation was found to be stable using molecular dynamic simulations. SPRi indicated that LicoA bound to TLR4-MD2 recombinant protein with a KD of 3.87 × 10^-7 M. LicoA dose-dependently reduced LPS-488 binding to the cell membrane. LicoA was found to significantly inhibit LPS-induced lung damage and inflammation. Furthermore, LicoA inhibited TLR4 expression, MAPK and NF-κB activation in a dose-dependent manner. The inhibitory effects of GL and LicoA on LPS-induced inflammation and TLR4 signaling activation were partly eliminated by TLR4 overexpression.

CONCLUSION

Our findings imply that GL and LicoA exert inhibitory effects on inflammation by targeting the TLR4 directly.

Liquiritin inhibits MRGPRX2-mediated pseudo-allergy through the PI3K/AKT and PLCγ signaling pathways

Liquiritin is a natural flavone with a variety of pharmacological effects derived from the medicinal food homology plant Glycyrrhiza uralensis Fisch. As a kind of lethal allergic reactions, pseudo-allergic reactions (PARs) arise from the Mas-related G protein coupled receptor X2 (MRGPRX2)-triggered fast degranulation of mast cells (MCs). In the current work, the anti-pseudo-allergy action and potential mechanisms of liquiritin were explored in vivo and in vitro. Liquiritin suppressed the calcium influx and degranulation elicited by Compound 48/80 (C48/80) in mouse peritoneal mast cells (MPMCs). In mice, liquiritin also inhibited the C48/80-elicited hind paw extravasation, as well as the elevations in TNF-α and histamine levels. Molecular docking combined with detection of HEK293T cells expressing human MRGPRX2 showed that liquiritin was a potential MRGPRX2 antagonist and inhibited PARs through the PI3K/AKT and PLCγ signaling pathways downstream of MRGPRX2. The present work opens a new avenue for the PARs management.

Cytotoxic and Antimigratory Activity of Retrochalcones from Glycyrrhiza echinata L. on Human Cancer Cells

Cytotoxic activity-guided fractionation studies on Glycyrrhiza echinata roots led to the isolation of eight compounds (1-8). Chemical structures of the isolates were identified by NMR and MS analysis. Among the tested molecules, retrochalcones namely echinatin (3) (IC₅₀ =23.45-41.83 μM), licochalcone B (4) (IC₅₀ =36.04-39.53 μM) and tetrahydroxylmethoxychalcone (5) (IC₅₀ =7.09-80.81 μM) were the most active ones against PC3, MCF7 and HepG2 cells. Moreover, 5 exhibited selectivity on prostate cancer cells (SI: 5.19). Hoechst staining and Annexin V/PI binding assays as well as cell cycle analysis on the compounds 3 (23 μM) and 5 (5 and 7 μM) demonstrated that these retrochalcones induced apoptosis and significantly suppressed cell cycle in G₁ and G₂ /M phases. Furthermore, 3 and 5 showed antimigratory effects on PC3 cells by wound healing assay. The results indicated that tested retrochalcones most particularly 5 could be potential anticancer drug candidates that prevent proliferation and migration of cancer cells.

Genome-Wide Identification of SnRK1 Catalytic α Subunit and FLZ Proteins in Glycyrrhiza inflata Bat. Highlights Their Potential Roles in Licorice Growth and Abiotic Stress Responses

Sucrose non-fermenting-1-related protein kinase-1 (SnRK1) and its scaffolding proteins, FCS-like zinc finger proteins (FLZs), are well conserved in land plants and involved in various processes of plant growth and stress responses. Glycyrrhiza inflata Bat. is a widely used licorice species with strong abiotic stress resistance, in which terpenoids and flavonoids are the major bioactive components. Here, we identified 2 SnRK1 catalytic α subunit encoding genes (GiSnRK1α1 and GiSnRK1α2) and 21 FLZ genes in G. inflata. Polygenetic analysis showed that the 21 GiFLZs could be divided into three groups. A total of 10 representative GiFLZ proteins interact with GiSnRK1α1, and they display overlapped subcellular localization (mainly in the nucleus and the cytoplasm) when transiently expressed in Nicotiana benthamiana leaf cells. Coinciding with the existence of various phytohormone-responsive and stress-responsive cis-regulatory elements in the GiSnRK1α and GiFLZ gene promoters, GiFLZs are actively responsive to methyl jasmonic acid (MeJA) and abscisic acid (ABA) treatments, and several GiFLZs and GiSnRK1α1 are regulated by drought and saline-alkaline stresses. Interestingly, GiSnRK1α and 20 of 21 GiFLZs (except for GiFLZ2) show higher expression in the roots than in the leaves. These data provide comprehensive information on the SnRK1 catalytic α subunit and the FLZ proteins in licorice for future functional characterization.

Chemical analysis of the Chinese herbal medicine licorice (Gan-Cao): An update review

ETHNOPHARMACOLOGICAL RELEVANCE

Licorice, called Gan-Cao in China, is one of the most popular traditional herbal medicines. It is derived from the dried roots and rhizomes of Glycyrrhiza uralensis, G. glabra, and G. inflata. Licorice is recorded in the pharmacopoeias of China, Japan, US, and Europe.

AIM

This review updates research progress of licorice from the perspectives of chemical analysis, quality evaluation, drug metabolism, and pharmacokinetic studies from 2009 to April 2022.

MATERIALS AND METHODS

Both English and Chinese literatures were collected from databases including PubMed, Elsevier, Web of Science, and CNKI (Chinese). Licorice, extraction, structural characterization/identification, quality control, metabolism, and pharmacokinetics were used as keywords.

RESULTS

Newly developed analytical methods, including LC/UV, 2DLC, LC/MS, GC/MS, and mass spectrometry imaging (MSI) for chemical analysis of licorice were summarized.

CONCLUSION

This review provides a comprehensive summary on chemical analysis of licorice.

The Ability of Acid-Based Natural Deep Eutectic Solvents to Co-Extract Elements from the Roots of Glycyrrhiza glabra L. and Associated Health Risks

The roots of licorice (Glycyrrhiza glabra L.) have been widely used in traditional and officinal medicines for the treatment of different diseases. Natural deep eutectic solvents (NADES) have become popular for the extraction of active principles from medicinal plants. However, the ability of NADES to co-extract trace elements during the isolation of target active compounds is rarely investigated. The aim of this study was to analyze the content of trace elements in acid-based NADES extracts from the roots of G. glabra and the health risks associated with them. In this study, we have tested for the first time the ability of several acid-based NADES to co-extract glycyrrhizic acid (GA) and trace elements from the roots of G. glabra. GA has been identified as the dominant phytochemical in G. glabra NADES extracts (0.145-0.495 mg/g). Due to the close pKa of lactic acid and GA, the yield of GA in lactic acid-based NADES was higher in comparison with other tested NADES. The yield of GA in NADES3-NADES5 was statistically significant and surpassed the yield of GA in water. The recovery of all elements (except Li) by all tested NADES was low (less than 6%). According to an ANOVA test, the hydrogen bond donor type plays a decisive role in the extraction of elements. A strong positive correlation between the recovery of GA and MPI was noted. The metal pollution index, hazard quotient, hazard index, and chronic daily intake were calculated and suggest that all tested NADES extracts of G. glabra roots were nontoxic and possess no health risk for both ingestion and topical application.

Diprenylated flavonoids from licorice induce death of SW480 colorectal cancer cells by promoting autophagy: Activities of lupalbigenin and 6,8-diprenylgenistein

ETHNOPHARMACOLOGICAL RELEVANCE

Licorice is a well-known herbal medicine, and we previously found that several licorice prenylated flavonoids could cause death of SW480 colorectal cancer cells by promoting autophagy. Given many kinds of prenylated flavonoids in licorice, the activities of other compounds deserve further investigation. In addition, the contribution of isoprenyl groups on the autophagy promotion activities has not been clarified.

AIM OF THE STUDY

This study aimed to investigate whether lupalbigenin (LPB) and 6,8-diprenylgenistein (DPG), two licorice diprenylated flavonoids, could induce autophagic cell death of SW480 cells, and clarify the contribution of isoprenyl groups.

MATERIALS AND METHODS

Cytotoxic activities of LPB and DPG were tested by using an MTT method, and apoptosis induction effects were evaluated by PI-Annexin V staining-based flow cytometry and protein levels of caspase-3 and PARP-1. Autophagy promotion effects of LPB and DPG were assessed by protein levels of LC3, p62, Akt and mTOR as well as number of autophagosomes in cells, and autophagy inhibitor chloroquine (CQ) was involved to identify the role of autophagy on LPB or DPG-caused death of SW480 cells. In addition, two groups of structurally similar diprenylated, mono-prenylated and free flavonoids were obtained from licorice, which were used to investigate the contribution of isoprenyl groups on their autophagy promotion activities.

RESULTS

Both LPB and DPG significantly induced apoptosis of SW480 cells with strong cytotoxic activities, and meanwhile, they also promoted autophagy probably through the Akt/mTOR signaling pathway. Further studies indicated that LPB and DPG could induce autophagic cell death of SW480 cells. Moreover, isoprenyl groups contributed mainly to the cytotoxic and autophagy promotion activities of licorice prenylated flavonoids.

CONCLUSION

This study reported for the first time that licorice diprenylated flavonoids LPB and DPG induced death of SW480 cells by promoting autophagy, which was mainly attributed to the isoprenyl groups. The results provided theoretical basis for researches on anti-colorectal cancer drugs and their structural modification.

Metabolic engineering to enhance the accumulation of bioactive flavonoids licochalcone A and echinatin in Glycyrrhiza inflata (Licorice) hairy roots

Echinatin and licochalcone A (LCA) are valuable chalcones preferentially accumulated in roots and rhizomes of licorice (Glycyrrhiza inflata). The licorice chalcones (licochalcones) are valued for their anti-inflammatory, antimicrobial, and antioxidant properties and have been widely used in cosmetic, pharmaceutical, and food industries. However, echinatin and LCA are accumulated in low quantities, and the biosynthesis and regulation of licochalcones have not been fully elucidated. In this study, we explored the potential of a R2R3-MYB transcription factor (TF) AtMYB12, a known regulator of flavonoid biosynthesis in Arabidopsis, for metabolic engineering of the bioactive flavonoids in G. inflata hairy roots. Overexpression of AtMYB12 in the hairy roots greatly enhanced the production of total flavonoids (threefold), echinatin (twofold), and LCA (fivefold). RNA-seq analysis of AtMYB12-overexpressing hairy roots revealed that expression of phenylpropanoid/flavonoid pathway genes, such as phenylalanine ammonia-lyase (PAL), chalcone synthase (CHS), and flavanone 3'-hydroxylase (F3'H), is significantly induced compared to the control. Transient promoter activity assay indicated that AtMYB12 activates the GiCHS1 promoter in plant cells, and mutation to the MYB-binding motif in the GiCHS1 promoter abolished activation. In addition, transcriptomic analysis revealed that AtMYB12 overexpression reprograms carbohydrate metabolism likely to increase carbon flux into flavonoid biosynthesis. Further, AtMYB12 activated the biotic defense pathways possibly by activating the salicylic acid and jasmonic acid signaling, as well as by upregulating WRKY TFs. The transcriptome of AtMYB12-overexpressing hairy roots serves as a valuable source in the identification of potential candidate genes involved in LCA biosynthesis. Taken together, our findings suggest that AtMYB12 is an effective gene for metabolic engineering of valuable bioactive flavonoids in plants.

GURFAP: A Platform for Gene Function Analysis in Glycyrrhiza Uralensis

Glycyrrhiza uralensis (Licorice), which belongs to Leguminosae, is famous for the function of pharmacologic action and natural sweetener with its dried roots and rhizomes. In recent years, the whole-genome sequence of G. uralensis has been completed, which will help to lay the foundation for the study of gene function. Here, we integrated the available genomic and transcriptomic data of G. uralensis and constructed the G. uralensis gene co-expression network. We then annotated gene functions of G. uralensis via aligning with public databases. Furthermore, gene families of G. uralensis were predicted by tools including iTAK (Plant Transcription factor and Protein kinase Identifier and Classifier), HMMER (hidden Markov models), InParanoid, and PfamScan. Finally, we constructed a platform for gene function analysis in G. uralensis (GURFAP, www.gzybioinfoormatics.cn/GURFAP). For analyzed and predicted gene function, we introduced various tools including BLAST (Basic local alignment search tool), GSEA (Gene set enrichment analysis), Motif, Heatmap, and JBrowse. Our analysis based on this platform indicated that the biosynthesis of glycyrrhizin might be regulated by MYB and bHLH. We also took CYP88D6, CYP72A154, and bAS gene in the synthesis pathway of glycyrrhizin as examples to demonstrate the reliability and availability of our platform. Our platform GURFAP will provide convenience for researchers to mine the gene function of G. uralensis and thus discover more key genes involved in the biosynthetic pathway of active ingredients.

An Integrated Pharmacology-Based Strategy to Investigate the Potential Mechanism of Xiebai San in Treating Pediatric Pneumonia

Xiebai San (XBS) is a traditional Chinese medicine (TCM) prescription that has been widely used to treat pediatric pneumonia since the Song dynasty. To reveal its underlying working mechanism, a network pharmacology approach was used to predict the active ingredients and potential targets of XBS in treating pediatric pneumonia. As a result, 120 active ingredients of XBS and 128 potential targets were screened out. Among them, quercetin, kaempferol, naringenin, licochalcone A and isorhamnetin showed to be the most potential ingredients, while AKT1, MAPK3, VEGFA, TP53, JUN, PTGS2, CASP3, MAPK8 and NF-κB p65 showed to be the most potential targets. IL-17 signaling pathway, TNF signaling pathway and PI3K-Akt signaling pathway, which are involved in anti-inflammation processes, immune responses and apoptosis, showed to be the most probable pathways regulated by XBS. UPLC-Q/Orbitrap HRMS analysis was then performed to explore the main components of XBS, and liquiritin, quercetin, kaempferol, licochalcone A and glycyrrhetinic acid were identified. Molecular docking analysis of the compounds to inflammation-associated targets revealed good binding abilities of quercetin, kaempferol, licochalcone A and liquiritin to NF-κB p65 and of quercetin and kaempferol to Akt1 or Caspase-3. Moreover, molecular dynamics (MD) simulation for binding of quercetin or kaempferol to NF-κB p65 revealed dynamic properties of high stability, high flexibility and lowbinding free energy. In the experiment with macrophages, XBS markedly suppressed the (Lipopolysaccharides) LPS-induced expression of NF-κB p65 and the production of pro-inflammatory cytokines IL-6 and IL-1β, supporting XBS to achieve an anti-inflammatory effect through regulating NF-κB p65. XBS also down-regulated the expression of p-Akt (Ser473)/Akt, Bax and Caspase-3 and up-regulated the expression of Bcl-2, indicating that regulating Akt1 and Caspase-3 to achieve anti-apoptotic effect is also the mechanism of XBS for treating pediatric pneumonia. Our study helped to reveal the pharmacodynamics material basis as well as the mechanism of XBS in treating pediatric pneumonia.

Licorice (Glycyrrhiza glabra, G. uralensis, and G. inflata) and Their Constituents as Active Cosmeceutical Ingredients

The interest in plant extracts and natural compounds in cosmetic formulations is growing. Natural products may significantly improve cosmetics performance since they have both cosmetic and therapeutic-like properties, known as cosmeceutical effects. Glycyrrhiza genus, belonging to the Leguminosae family, comprises more than 30 species, widely distributed worldwide. The rhizomes and roots are the most important medicinal parts currently used in pharmaceutical industries and in the production of functional foods and food supplements. In the last few years, the interest in their potential activities in cosmetic formulations has greatly increased. Glycyrrhiza spp. extracts are widely implemented in cosmetic products for their good whitening effect. The biological effects of Glycyrrhiza extracts are especially ascribable to the occurrence of specialized metabolites belonging to the flavonoid class. This review focuses on the botany and the chemistry of the main investigated Glycyrrhiza spp. (G. glabra, G. uralensis, and G. inflata) along with their cosmeceutical activities categorized as skin anti-aging, photoprotective, hair care, and anti-acne. It has been highlighted how, along with Glycyrrhiza extracts, three main flavonoids namely licochalcone A, glabridin, and dehydroglyasperin C are the most investigated compounds. It is noteworthy that other molecules from licorice show potential cosmeceutical effects. These data suggest further investigations to clarify their potential value for cosmetic industries.

A general procedure for establishing composite quality evaluation indices based on key quality attributes of traditional Chinese medicine

Licorice, a medicinal herb and food flavor ingredient, has been widely used in traditional Chinese medicine (TCM) for the past 4000 years. In this study, we propose a new quality evaluation approach for licorice quality control based on the key quality attributes commonly used in TCM. The high quality of TCM formulations is ensured by verifying the genuine origin and implementing good agricultural and collection practices for each medicinal herb. In our study, the genuine production area, the harvest season, and the number of growth years were considered the key quality attributes of TCM. To ensure the representativeness of our analysis, we obtained a total of 158 licorice sample batches that differed in the number of growth years, the location of the production areas, and the season for harvesting. Initially, the 158 sample batches were subjected to ultra-high-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UHPLC-QTOF-MS/MS). A preliminary screen identified 11 licorice compounds related to the three key quality attributes of TCM . An analysis by ultra-high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry (UHPLC-TQ-MS/MS) verified the presence of 34 compounds in all licorice samples. These 34 compounds included the 11 compounds related to the three key quality attributes of the samples, along with other bioactive components identified in previous studies. After using UHPLC-TQ-MS/MS to assess the signal peak intensities of the 34 compounds, we selected 17 licorice compounds to establish sample content evaluation indices, which were determined by high-performance liquid chromatography at four different wavelengths in all 158 licorice sample batches. Finally, the screen identified nine compounds that were closely associated with the quality attributes of licorice based on principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA). Our results suggested that liquiritin and eight other compounds could be used as quality control indicators of licorice, which provided a foundation to establish the TCM quality composite evaluation index (TCM QCEI). In summary, this research concept can serve as a reference for research on quality markers and the evaluation of TCM.