Glycyrrhizin Content Research Articles

La (NO3)3 substantially fortified Glycyrrhiza uralensis’s resilience against salt stress by interconnected pathways

The taproot of Glycyrrhiza uralensis is globally appreciated for its medicinal and commercial value and is one of the most popular medicinal plants. With the decline of wild G. uralensis resources, cultivated G. uralensis has become a key method to ensure supply. However, soil salinization poses challenges to G. uralensis cultivation and affects the yield and quality of it. In this study, the inhibitory effects of NaCl and Na2SO4 on yield and quality of G. uralensis were comprehensively evaluated in a three-year large-scale pot experiment, and the alleviating effects of supplementation with lanthanum nitrate (La (NO3)3) on G. uralensis were further evaluated under salt stress. The findings indicate that La (NO3)3 significantly strengthened the plant's salt tolerance by enhancing photosynthetic capacity, osmolyte accumulation, antioxidant defenses, and cellular balance of ions, which led to a substantial increase in root biomass and accumulation of major medicinal components. In comparison to the NaCl-stress treatment, the 0.75 M La (NO3)3 + NaCl treatment resulted in a 20% and 34% increase in taproot length and biomass, respectively, alongside a 52% and 43% rise in glycyrrhizic acid and glycyrrhizin content, respectively. Similar improvements were observed with 0.75 M La (NO3)3 + Na2SO4 treatment, which increased root length and biomass by 14% and 26%, respectively, and glycyrrhizic acid and glycyrrhizin content by 40% and 38%, respectively. The combined showed that application of La (NO3)3 not only significantly improved the salt resilience of G. uralensis, but also had a more pronounced alleviation of growth inhibition induced by NaCl compared to Na2SO4 stress except in the gas exchange parameters and root growth. This study provides a scientific basis for high-yield and high-quality cultivation of G. uralensis in saline soils and a new approach for other medicinal plants to improve their salt tolerance.Graphical

Antimicrobial and Antioxidant Activities of 18β-Glycyrrhetinic Acid Biotransformed by Aspergillus niger

The search for novel plant-based antioxidant and antibacterial medication has garnered a lot of attention lately. Glycyrrhiza glabra, known as licorice, is one of the most important medicinal plants. The primary component of Glycyrrhiza glabra is glycyrrhizin, which is biotransformed into 18α- and 18β-glycyrrhetinic acid for a variety of medicinal purposes. The goal of this study was to improve the bioavailability of glycyrrhizin by its biotransformation into glycyrrhetinic acid by Aspergillus niger. The biotransformation process was optimized using response surface methodology. A two-level Plackett–Burman design was employed to identify the factors that had a significant impact on the process of biotransformation. The three main variables were pH, glycerrhizin concentration, and incubation time. These three medium components were further optimized using a 3-level Box–Behnken design, and their optimum levels were pH of 8, an incubation period of 6 days, and a glycyrrhizin concentration of 1%. Using these optimum conditions, the maximum level obtained was 159% greater than in the screening experiment. Regarding the antimicrobial activity of glycyrrhizin extract, Bacillus subtilis emerged as the most sensitive organism with the lowest MIC (60 µg/mL) and the highest zone of inhibition (17 mm). The most resistant organism was Pseudomonas aeruginosa, which had the highest MIC (400 µg/mL) and the smallest zone of inhibition (10 mm). In the case of glycyrrhetinic acid, Bacillus subtilis was the most sensitive organism with the highest zone of inhibition (32 mm) and the lowest MIC (20 µg/mL). Pseudomonas aeruginosa was the most resistant organism, with the lowest zone of inhibition (18 mm), and the highest MIC (140 µg/mL). The antioxidant activity of glycyrrhizin extract increased from 12.81% at a concentration of 63 µg/100 µL to 41.41% at a concentration of 1000 µg/100 µL, while that of glycyrrhetinic acid extract increased from 35.5% at a concentration of 63 µg/100 µL to 76.85% at a concentration of 1000 µg/100 µL. The present study concluded that biotransformation of glycyrrhizin into glycyrrhetinic acid increased its bioavailability and antioxidant and antimicrobial activities. Glycyrrhizin and glycyrrhetinic acid might be used as a natural antimicrobial and antioxidant in pharmaceutical industries

Chemical quality evaluation and characteristics of interspecific hybrid (G. uralensis × G. glabra) C-18 strain as a new Licorice cultivar.

The development of new cultivars is essential for establishing a method of producing licorice in Japan. A suitable new cultivar for domestic licorice production, known as the interspecific hybrid strain C-18, was developed by crossbreeding Glycyrrhiza uralensis Fisch. (as the seed parent, possessing a high glycyrrhizin (GL) content, strain OMP-28) and Glycyrrhiza glabra L. (as the pollen parent, known for vigorous growth, strain OMP-10). Both G. uralensis and G. glabra are specified in the Pharmacopoeia of Japan (18th edition) as the source plants for Glycyrrhizae Radix. After 2years of cultivation, strain C-18 exhibited robust growth, with a fresh weight of 148.8g and a stem diameter of 0.89mm. The GL content in the dry weight was measured at 3.61%. Seedlings cultivated from rhizomes in the field for 2years showed a tap root fresh weight per plant of 120 ± 21g, with an average GL content relative to the dry weight of 2.68% ± 0.38%. Although glabridin, a characteristic compound of G. glabra, was not detected, glycycoumarin, a characteristic compound of G. uralensis, was detected via HPLC analysis. Strain C-18 contained glycycoumarin as a characteristic compound of G. uralensis but lacked glabridin, a compound characteristic of G. glabra. Additionally, 2,3-dehydrokievitone (1) and parvisoflavone A (2) were identified as distinctive components of the interspecific hybrid (G. uralensis × G. glabra) C-18.

Fungal endophytes Fusarium solani SGGF14 and Alternaria tenuissima SGGF21 enhance the glycyrrhizin production by modulating its key biosynthetic genes in licorice (Glycyrrhiza glabra L.).

To identify promising fungal endophytes that are able to produce glycyrrhizin and enhance it in licorice and the mechanisms involved. Fifteen fungal endophytes were isolated from Glycyrrhiza glabra L. rhizomes among which SGGF14 and SGGF21 isolates were found to produce glycyrrhizin by 4.29 and 2.58µg g-1 dry weight in the first generation of their culture. These isolates were identified as Fusarium solani and Alternaria tenuissima, respectively, based on morphological characteristics and sequence analysis of internal transcribed spacer, TEF1, ATPase, and CAL regions. Subsequently, G. glabra plants were inoculated with these fungal isolates to examine their effect on glycyrrhizin production, plant growth parameters and the expression of key genes involved in glycyrrhizin pathway: SQS1, SQS2, bAS, CAS, LUS, CYP88D6, and CYP72A154. Endophytes were able to enhance glycyrrhizin content by 133%-171% in the plants. Natural control (NC) plants, harboring all natural endophytes, had better growth compared to SGGF14- and SGGF21-inoculated and endophyte-free (EF) plants. Expression of SQS1, SQS2, CYP88D6, and CYP72A154 was upregulated by inoculation with endophytes. LUS and CAS were downregulated after endophyte inoculation. Expression of bAS was higher in SGGF21-inoculated plants when compared with NC, EF, and SGGF14-inoculated plants. Two selected fungal endophytes of G. glabra can produce glycyrrhizin and enhance glycyrrhizin content in planta by modulating the expression of key genes in glycyrrhizin biosynthetic pathway.

Glycyrrhizin intake higher than the current international guidelines has no detectable hypermineralocorticoid-like effect in dogs.

Glycyrrhizin-enriched extracts from licorice root are associated with numerous health benefits and are widely used in phytotherapy. There is evidence that ingesting glycyrrhizin beyond threshold concentrations can impact the metabolism of cortisol, inhibiting its conversion to an inactive form, cortisone, via 11-hydroxysteroid dehydrogenase. A consequence can be a form of hypermineralocorticoidism, with elevated potassium excretion and associated hypertension, as demonstrated in rats and humans. Here, 3 orally dosed concentrations of glycyrrhizin (0.2, 0.4 and 0.6 mg/kg bodyweight/day) were assessed over 28 days in dogs. As the current guidelines reflect a lack of reliable data in this species, our aim was to provide relevant information for doses above the current guidelines. The specific purpose of this study was to demonstrate that an intake of licorice with a known therapeutic benefit to dogs does not cause hypermineralocorticoidism in this species. No changes in blood pressure, nor electrolyte excretion were observed in the dogs given these three glycyrrhizin concentrations.

Optimization of indole acetic acid produced by plant growth promoting fungus, aided by response surface methodology

Indole acetic acid (IAA) is one of the prime communicator playing a chief role in the interaction between host plant and endophytes. IAA produced by the endophytes primarily contributes to plant growth and development. Here, we optimized IAA production by an endophytic fungus Diaporthe terebinthifolli GG3F6 isolated from the asymptomatic rhizome of Glycyrrhiza glabra employing response surface methodology (RSM) and exploring its effect on the host plant biology. The methodology revealed 1.1 fold increases in IAA accumulation. The maximum IAA (121.20 μg/mL) was achieved using tryptophan substrate (1 mg/mL) in Potato dextrose broth (48 g/L) adjusted to pH 12 and incubated at 35 °C for 7 days. The significantly low p-value (p < 0.0001) of the experiment propounded that the model best fits the experimental data, and the independent variables have considerable effects on the production of IAA. Morphologically, the in-vitro grown G. glabra plants showed enhanced root and shoot growth when co-cultivated with the isolated endophytic fungal strain (GG3F6) relative to the control plants. Also, the enhanced accumulation of total phenolic (10.7 %) and flavonoid (10.2 %) in the endophyte treated plants was observed. The optimization of IAA production by an endophytic fungus using (RSM) has not been reported so far. Interestingly, 2.1 fold increase in glycyrrhizin content was recorded in GG3F6 treated in-vitro host plants as compared to the control plants. This suggested a potential use of D. terebinthifolli as a biostimulator for plant and enhanced accumulation of glycyrrhizin. The study highlights the dynamic host-endophyte interaction for exploitation in agricultural and pharmaceutical applications.

OBTAINING DRY EXTRACTS FROM LICORICE ROOTS (GLYCYRRHIZA GLABRA) AND ITS STANDARDIZATION

Licorice (Glycyrrhiza glabra) root has long been used in traditional medicine due to its various therapeutic properties. One of the main active components in licorice root is glycyrrhizin, which has been shown to possess numerous pharmacological effects. Glycyrrhizin, one of the major compounds present in licorice root, has been shown to possess anti-inflammatory, antioxidant, and anti-tumor propertiesas well as antiviral properties against influenza virus and coronavirus COVID-19. The demand for licorice root extracts is increasing, particularly for use in the food and pharmaceutical industries. However, the quality and consistency of licorice extracts can vary depending on the extraction method used. Therefore, the aim of this study was to optimise the technology for obtaining dry extracts from licorice roots and standardise the process for increased consistency and quality of the final product. In this study, two different methods for extraction were compared: ultrasound-assisted extraction using water and alcohol-water solvents. The extracted samples were then subjected to various quality control tests, including glycyrrhizin content and moisture content. The content of glycyrrhizin in the obtained dry extracts was determined using high-performance liquid chromatography (HPLC). The standardisation of the dry extract was performed according to the Pharmacopoeia of the Eurasian Economic Union. The results showed that the optimised technology for obtaining dry extracts from licorice roots was water extraction with ultrasound, as it yielded a higher content of glycyrrhizin compared to ethanol extraction with ultrasoundand the optimal conditions for ultrasound-assisted extraction were an extraction time of 60 minutes, frequency of ultrasound bath at 40 kHz, an extraction temperature of 30°C, and a solid-to-liquid ratio of 1:6. The standardisation process confirmed the presence of glycyrrhizic acid and purity of the obtained dry extract.

Improving drought tolerance and glycyrrhizin content of licorice plant by EPS-producing cyanobacteria

We evaluated the effects of two selected EPS-producing cyanobacterial strains for microbe-dependent drought tolerance in native licorice plant (Glycyrrhiza glabra) and addressed the mechanisms, which might be improved through these interactions. These bacteria were inoculated on the soils in a form of single strain (Anabaena sphaerica or Nostoc pruniforme) or two strains (Anabaena + Nostoc) in greenhouse conditions. The growth parameters, physiological and metabolical responses among treatments were investigated through assaying the antioxidants and glycyrrhizin contents in the plants grown in both normal condition and moderate water stress condition (FC 50%). The reduction of the ratio of root/shoot in response to drought (FC 50%) was correlated with amount of specific metabolites production, including glycyrrhizic acid (GA), glabridin (GB), liquiritin (LQ) and liquiritigenin (LG), especially in soil treated by Anabaena + Nostoc (P < 0.05). In water-deficient conditions, accumulation of GA in plants treared by Anabaena + Nostoc was boosted by 64% and 69% compared to Anabaena and the control, respectively. Besides, a significant increase in catalase activity (25%) was perceived in this treatment after exposure to drought stress. These results highlight the potential role of enzymatic antioxidants and the increase of GA content in responsing to the drought tolerance in licorice plant. Our findings suggest that using EPS-producing strains of Cyanobacteria is an efficient treatment to improve the drought tolerance in cultivation of medicinal plant in soil of arid and semi-arid regions.

Determination and Comparison of Bioactive Compounds in Different Parts of Glycyrrhiza Species

Glycyrrhiza spp., one of the most widely used herbal medicine for centuries in the world, contain a large number of bioactive such as triterpene saponins and flavonoids which are the main constituents and show broad biological activity. The present study aimed to evaluate the phytochemical profile of extracts from different parts (roots, stems and leaves) of all wild Glycyrrhiza spp. grown in Turkey and to reveal that other parts besides the roots are a rich source of bioactive compounds with potential use in the pharmaceutical and food industries. For this purpose, extracted bioactive compounds from different parts of five Glycyrrhiza spp. collected in different provinces of Turkey were determined and compared. The microwave-assisted extraction method, which is mentioned as a green technique and requires low solvent and extraction time, was applied. Determination of bioactives was performed using liquid chromatography- electrospray ionisation tandem mass spectrometry (LC-ESI-MS/MS). Among the collected Glycyrrhiza spp.; in leaf parts, the highest glycyrrhizin (GL) (2.05±0.07 mg g-1) and glycyrrhetinic acid (GA) (0.107±0.005 mg g-1) contents were found in Glycyrrhiza flavescens ssp. flavescens; the highest carbenoxolone (CBX) (0.133±0.006 mg g-1) and liquiritin (LQ) (1.644±0.014mg g-1) contents were in Glycyrrhiza glabra grown in Polatlı. In stem parts, the highest GL (2.735±0.04 mg g-1), CBX (0.069±0.004 mg g-1) and LQ (0.602±0.010 mg g-1) contents were determined in G. glabra plant growing in Ankara. In root parts, the highest GL (14.68±0.09 mg g-1) and LQ (9.735±0.046 mg g-1) contents were detected in G. glabra plant growing in Gaziantep while the highest GA (0.136±0.005 mg g-1) and CBX (0.188±0.067 mg g-1) contents in Glycyrrhiza flavescens ssp. antalyensis. Thus, it was determined which location in Turkey and which parts of Glycyrrhiza spp. that grow wild in Turkey can be used as a priority for the food and pharmaceutical industry with this study.

Glycyrrhizin-Based Hydrogels Accelerate Wound Healing of Normoglycemic and Diabetic Mouse Skin

Efficient wound repair is crucial for mammalian survival. Healing of skin wounds is severely hampered in diabetic patients, resulting in chronic non-healing wounds that are difficult to treat. High-mobility group box 1 (HMGB1) is an important signaling molecule that is released during wounding, thereby delaying regenerative responses in the skin. Here, we show that dissolving glycyrrhizin, a potent HMGB1 inhibitor, in water results in the formation of a hydrogel with remarkable rheological properties. We demonstrate that these glycyrrhizin-based hydrogels accelerate cutaneous wound closure in normoglycemic and diabetic mice by influencing keratinocyte migration. To facilitate topical application of glycyrrhizin hydrogels on cutaneous wounds, several concentrations of glycyrrhizinic acid in water were tested for their rheological, structural, and biological properties. By varying the concentration of glycyrrhizin, these hydrogel properties can be readily tuned, enabling customized wound care.

Stabilization of solid lipid nanoparticles with glycyrrhizin

This study investigated the influence of saponin glycyrrhizin on the formation and stability of solid lipid nanoparticles. The hypothesis was that glycyrrhizin facilitates the formation of stable crystalline lipid particles due to its molecular characteristics and slows down polymorphic transition. Tristearin solid lipid nanoparticles emulsified with glycyrrhizin at varying concentrations at pH 7 and 3 were generated by hot high-pressure homogenization. The influence of glycyrrhizin on the physical stability and crystallization behavior of solid lipid nanoparticles was evaluated by dynamic and static lights scattering, electrophoretic light scattering, optical microscopy, visual observations, and differential scanning calorimetry. The results showed that glycyrrhizin formed nanosized solid lipid nanoparticles at both pH 7 and 3. The glycyrrhizin concentration and the pH applied governed the crystallization behavior and the polymorphic stability as well as the physical appearance. Overall, glycyrrhizin showed remarkable ability to stabilize solid lipid nanoparticles against polymorphic transition over time. These results are relevant for food, pharmaceutical, and cosmetic industries to form stable carrier systems by using natural plant-based saponins as surfactants.

Development of Highly Sensitive Chemiluminescence Enzyme Immunostaining Assay to Determine Glycyrrhizin Content Using Anti-glycyrrhizin Monoclonal Antibody

Licorice, the root of Glycyrrhiza spp., is used in a large number of herbal medicines, such as traditional Chinese medicines, Japanese Kampo medicines, and therapeutic drugs. Since glycyrrhizin (GL) is among the main components in licorice and exhibits numerous beneficial pharmacological activities, the content of GL directly affects biological activity. The quality control based on GL content is an important factor in ensuring biological activity; however, the content of GL in licorice varies depending on plant cultivation environment, genetic factors, and species type. Previously, we prepared an anti-GL monoclonal antibody (anti-GL mAb) and employed it in various immunochemical assays for quality control of licorice and licorice-based products. In this study, we employed the anti-GL mAb in chemiluminescence enzyme immunostaining (CLEIS) to develop a very simple, rapid, specific, and sensitive quality control assay for licorice products, with a limit of detection of 3.9 ng. Furthermore, the CLEIS assay enabled semiquantitative analysis of GL in Kampo medicines. Our results showed that multiple samples can be simultaneously analyzed using CLEIS, and it is a useful tool for determining GL content, as well as ensuring chemical quality control of licorice-containing products and herbal medicines.

재배기간을 달리한 감초 추출물의 항산화 및 미백 활성

The purpose of this study was to investigate the quality characteristics, antioxidant and skin-whitening activity of Glycyrrhiza uralensis extract cultivated for different periods. The physicochemical components such as pH, total acid, reducing sugar, and content of potent functional components (glycyrrhizin, glabridin, liquiritin, liquiritigenin and glycyrrhisoflavone) and the tyrosinase inhibitory activity were investigated. Also, the antioxidant activities such as DPPH, ABTS, and total phenolic and total flavonoid content were measured. The total phenolic and flavonoid contents were observed to be the highest in the 1-year-old (K1) sample group, and showed values of 18.32% and 6.94%, respectively. The 3-year-old (K3) sample showed the highest content of glycyrrhizin at 163.65 ㎎/100 g. Compared to the other samples, the K1 sample had a superior content of glabridin, liquiritin, liquiritigenin, and glycyrrhisoflavone. The K1 sample also showed the highest skin-whitening activity of 54.68±1.23%. Therefore, it was concluded that the K1 sample has good antioxidant and skin-whitening activity and thus has the potential not only as a food material but also as a cosmetic material and various industrial uses.

LC-MS/MS standardization and validation of glycyrrhizin from the roots of Taverniera cuneifolia: A potential alternative source of Glycyrrhiza glabra

Glycyrrhizin is a triterpene glycoside derived from Glycyrrhiza glabra and related species which is a renowned phytochemical used to cure a variety of ailments such as inflammation, sore throat, hepatitis etc. It is in huge demand owing to its various valuable properties. With the ever-increasing demand of glycyrrhizin, the search for alternative sources for glycyrrhizin is on rise. One such species with a scientific basis and good concentration of glycyrrhizin is Taverniera cuneifolia. A thin-layer chromatography (TLC) method was established to determine the presence of glycyrrhizin in T. cuneifolia. Further, standardisation and validation, a High performance liquid chromatography (model NEXERA-X2) with LCMS system (Model LCMS-8040) from Shimadzu were used. The analysis was performed by using shim-pack XR-ODS, C18 (75 mm × 3.0 mm) 2.2 μm. In this analysis, the mobile phase used was a combination of acetonitrile and a 20 mM ammonium acetate buffer that was subjected to gradient time programming and monitored by Multiple Reaction Monitoring (MRM) in positive ion mode. The method was validated for linearity, accuracy, precision, recovery, detection, and quantitation limit. The technique was confirmed to be linear within the concentration range of 5 ng/mL to 500 ng/mL with R2 > 0.991. The LOD and the LOQ were 2 ng/mL and 5 ng/mL respectively. The suggested approach satisfied the acceptance criteria for linearity, accuracy, precision, specificity, robustness, LOD, LOQ, and system adaptability.

Response surface methodology and artificial neural network modelling for optimization of solid-liquid extraction and rapid HPTLC analysis of glycyrrhizin in Glycyrrhiza glabra root

Glycyrrhizin, a major bioactive compound of Glycyrrhiza glabra has been used in traditional medicine system to treat several diseases. In the past few decades, its demand has been increased significantly for the active ingredient glycyrrhizin as well as for being a zero calorie sweetener. In the current study, extraction of glycyrrhizin from dry roots of G. glabra was established by reflux method. Quantitative estimation of glycyrrhizin content in the extracted samples was analysed by using high performance thin layer chromatography (HPTLC) system. In this study, response surface methodology (RSM) and artificial neural network (ANN) were used for the first time as a model to optimize the extraction conditions of glycyrrhizin from G. glabra roots in order to compare and establish effective prediction models. The extraction process variables including the time, temperature, solvent composition, particle size, solvent to solute ratio, pH and extraction steps were optimized using a Plackett-Burman design (PBD), Central Composite design (CCD), artificial neural network (ANN) and Multiple Layer Perceptron (MLP) on glycyrrhizin yield. The optimum extraction conditions were 55°C (extraction temperature), 45 min (extraction time), 55% (v/v) (ethanol concentration) and 30 ml/g (solvent to solute ratio) to obtain the maximum glycyrrhizin yield. The contributions of the quadratic model with high determination coefficient (R2=0.9806) were observed and showed good consistency between the experimental value 7.6 mg/g (0.76%) and predicted value 7.51 mg/g (0.751%). Response values were close to the predicted values with prediction accuracy as ANN > RSM, indicating that ANN model has higher prediction accuracy than RSM. The study suggests that RSM and ANN model system can be manipulated for the optimization and production of valuable bioactive compounds.

Formulation Development, Characterization and Antimicrobial Activity Evaluation of Sugar-Based and Sugar-Free Syrup Prepared with the Ingredients of Jushanda-Nazla

Jushanda (decoction), often used in traditional medicine, has many drawbacks like disagreeable taste, bulky dose, cumbersome preparation, and short stability. Therefore, in the present study, jushanda nazla (JN) was modified and optimized into a sugar-based (SBS) and sugar-free (SFS) syrup dosage form and evaluated for various physicochemical parameters, microbial contaminations and antimicrobial activities. JN was concentrated and reduced to minimum quantity by heating and twelve batches of SBS and five batches of SFS were prepared for optimization. Out of these, the best batch of SBS and SFS were selected based on consistency and minimum bulk. The best batches were further evaluated for the physicochemical parameter, microbial and heavy metal contamination. The finished products were also evaluated for antimicrobial activity against selected microbes. SBS was optimized with 170 mL JN reduced to 50 mL, sugar 40% (w/v) and consistency of one wire. SFS was optimized with 170 mL JN reduced to 30 mL, and 96 mg of aspartame. Organoleptic characters, ash value, viscosity, specific gravity and pH of finished products were satisfactory. The concentration of total phenolic, flavonoid, tannin, alkaloid and glycyrrhizin and chlorogenic acid were comparative in JN, SBS and SFS. SBS and SFS passed the WHO guideline for microbial and heavy metal contamination. Finished products showed significant antimicrobial activity against Streptococcus pyogenes, Streptococcus pneumoniae, Haemophilus influenzae and Salmonella. Analytical data of SBS and SFS showed significant optimistic results hence, generated data can be used for future reference. However, developed formulations should be further evaluated for their stability, safety and clinical efficacy.

Effect of Solvent Polarity on Extraction Yield of Total Flavonoids with Special Emphasis to Glabridin from Glycyrrhiza glabra Roots

Different organic solvents (ethanol, dichloromethane, ethyl acetate and acetone) were studied for their effects on the extraction efficiency of glabridin and total flavonoids (TF) from Glycyrrhiza glabra roots. The extract yield of Glycyrrhiza glabra roots was in the range of 3% to 6% following the extraction efficiency in the order ethanol>acetone>ethyl acetate>dichloromethane. A higher extraction yield of TF and glabridin was obtained with dichloromethane, followed by ethyl acetate, acetone and ethanol, indicating that the non-polar solvents help in optimal extraction of TF and glabridin. We also demonstrate for the first time, that the extraction efficiency of the flavonoids is not significantly affected by the use of the recovered solvents except in case of ethanol which reflects that the moisture absorbing capacity of the solvent dictates the extraction efficiency of such compounds. The glycyrrhizin content in all the extract types was rather low (0.1 % to 1%) except for extract prepared with water, where the glycyrrhizin content was ~10% as expected since glycyrrhizin is a polar compound. Interestingly, we observed that ethyl acetate selectively isolated only glabridin with no traces of glycyrrhizin, which is a finding reported for the first time.

Growth, phytochemical parameters and glycyrrhizin production in licorice (Glycyrrhiza glabra L.) grown in the field with saline water irrigation

Salinity is a worldwide problem in crops that can be managed using salt-tolerant species. Wild licorice (Glycyrrhiza spp.), a genus of the Fabaceae family that is considered medicinal and contains many secondary metabolites, including the triterpenoid glycyrrhizin, can grow in saline conditions. The effects of irrigating five different field-grown genotypes of Glycyrrhiza glabra with two levels of salinity (75/37.5/37.5 and 150/75/75 mM NaCl/CaCl2/MgSO4) have been studied, looking at some plant physiological and biochemical characteristics. Salinity led to decreases in leaf and root biomass and leaf relative water content, increases in leaf antioxidant enzyme activities (peroxidase, superoxide dismutase and polyphenol oxidase), and increases in osmolyte levels (soluble sugars, glycine betaine and proline) in leaves and roots. Salinity caused decreases in root glycyrrhizin concentrations in three of the genotypes and in glycyrrhizin contents in all of them (decreases ranging from 26% to 73% with intense salinity), likely as a result of the large decreases in root biomass. The glycyrrhizin content was only moderately affected by salinity in one of the genotypes (‘Kerman’). In this salinity-tolerant genotype, the expression of some glycyrrhizin biosynthesis genes (bAS, SQS1, SQS2, CYP72A154, CYP88D6 and UGT73) was increased by salinity, but this did not result in increases in glycyrrhizin contents. These results indicate that the genetic background of licorice affects glycyrrhizin contents and its response to salinity stress, and also that one of the genotypes studied can be used by farmers in soils affected by salinity.

Assessment of genotoxicity of Ssanghwa-tang, an herbal formula, by using bacterial reverse mutation, chromosome aberration, and in vivo micronucleus tests

Objectives: Ssanghwa-tang (SHT) is a traditional herbal formula comprising nine medicinal herbs, and it is used for reducing fatigue in Korea. SHT exerts various effects such as anti-inflammatory, antioxidant, and anti-aging activities, and protection against acute hepatotoxicity. However, the genotoxicity of SHT has not yet been established.Methods: Ten components were identified in SHT water extract by using high-performance liquid chromatography analysis. We assessed the genotoxicity of SHT by using bacterial reverse mutation (Ames test), chromosome aberration, and in vivo micronucleus tests.Results: The contents of paeoniflorin, glycyrrhizin, and liquiritin apioside in SHT were 15.57, 6.94, and 3.48 mg/g extract, respectively. SHT did not increase the revertant colonies of Salmonella typhimurium and Escherichia coli strains in the presence or absence of metabolic activity. Although SHT did not induce structurally abnormal chromosomes in Chinese hamster lung (CHL) cells in the presence of metabolic activity, the number of structurally aberrated chromosomes increased dose-dependently in the absence of metabolic activity. In the in vivo micronucleus test, SHT did not affect the formation of micronuclei compared with the vehicle control.Conclusions: Genotoxicity of SHT was not observed in the Ames test and in vivo micronucleus test. However, based on the results of chromosome aberration test, it can be presumed that SHT has the potential to induce genotoxicity because it induced structurally abnormal chromosomes in the absence of metabolic activity.

Computational and In Vitro Experimental Investigations Reveal Anti-Viral Activity of Licorice and Glycyrrhizin against Severe Acute Respiratory Syndrome Coronavirus 2.

Without effective antivirals, the COVID-19 pandemic will likely continue to substantially affect public health. Medicinal plants and phytochemicals are attractive therapeutic options, particularly those targeting viral proteins essential for replication cycle. Herein, a total 179 phytochemicals of licorice (Glycyrrhiza glabra) were screened and scrutinized against the SARS-CoV-2 main protease (Mpro) with considerable binding affinities in the range of −9.831 to −2.710 kcal/mol. The top 10 compounds with the best docking scores, licuraside, glucoliquiritin apioside, 7,3′-Dihydroxy-5′-methoxyisoflavone, licuroside, kanzonol R, neoisoliquiritin, licochalcone-A, formononetin, isomucronulatol, and licoricone, were redocked using AutoDock Vina, yielding −8.7 to −7.3 kcal/mol binding energy against Glycyrrhizin (−8.0 kcal/mol) as a reference ligand. Four compounds, licuraside, glucoliquiritin apioside, 7,3′-Dihydroxy-5′-methoxyisoflavone, and licuroside, with glycyrrhizin (reference ligand) were considered for the 100 ns MD simulation and post-simulation analysis which support the stability of docked bioactive compounds with viral protein. In vitro studies demonstrated robust anti-SARS-CoV-2 activity of licorice and glycyrrhizin under different treatment protocols (simulations treatment with viral infection, post-infection treatment, and pre-treatment), suggesting multiple mechanisms for action. Although both compounds inhibited SARS-CoV-2 replication, the half-maximal inhibitory concentration (IC50) of glycyrrhizin was substantially lower than licorice. This study supports proceeding with in vivo experimentation and clinical trials and highlights licorice and glycyrrhizin as potential therapeutics for COVID-19.