Glabridin Research Articles

Encapsulation nanoarchitectonics of glabridin with sophorolipid micelles for addressing biofilm hazards via extracellular polymeric substance permeation and srtA gene suppression

BackgroundBiofilm, a common drug-resistant phenotype of Staphylococcus aureus (S. aureus), demonstrates significant drug resistance and recurrence due to its extracellular polymeric substance (EPS) barrier and subsequent bacterial migration. Hence, there is an urgent need for effective solutions to mitigate the hazards posed by biofilms. ResultThis study developed a stable, low-toxicity multifunctional nanomicelle, GLA@SOL/EYL, by encapsulating glabridin (GLA) using sophorolipid (SOL) and egg yolk lecithin (EYL). Optimizations were performed for the hydration medium, the ratio of carrier materials to GLA, and EYL additions. GLA@SOL/EYL exhibited a particle size of 122.1 ± 0.8 nm and a surface potential of −66.4 ± 1.7 mV, endowing it with the ability to permeate biofilms EPS effectively. GLA@SOL/EYL encapsulated 98.3 ± 1.2 % of GLA and demonstrated a slow-release effect, significantly enhancing the bioavailability of GLA. The addition of EYL reduced the hemolytic toxicity of GLA@SOL/EYL and improved its encapsulation rate and stability. GLA@SOL/EYL reduced the minimum inhibitory concentration of GLA to 8 μg/mL and extended its inhibitory effect at low concentrations by rapidly disrupting the structural integrity of S. aureus. GLA@SOL/EYL may penetrate biofilms to disperse EPS and remove twice as much biofilm as GLA alone, thereby eliminating 99.99 % of S. aureus within biofilms, compared to 99 % bactericidal efficacy of GLA. Additionally, GLA@SOL/EYL inhibited 63.8 ± 1.8 % of biofilm formation by affecting the expression of the srtA gene, thereby reducing the expression of cell wall-anchoring protein genes. In contrast, the biofilm inhibition rates of GLA and blank micelles were less than 10 %. ConclusionGLA@SOL/EYL utilizes the nanoparticle effect to penetrate biofilms and deliver antimicrobial GLA. The SOL disperses the biofilm matrix while GLA is released to kill S. aureus, preventing bacterial dissemination and colonization. Thus, GLA@SOL/EYL presents an innovative strategy for effectively eradicating S. aureus biofilms and preventing new hazards in a one-step approach.

Sensitive sensing of GLA and ISL based on highly conductivity nitrogen-doped carbon synergistic dual-template molecularly imprinted ratiometric electrochemical sensor

A novel ratiometric Molecularly Imprinted Electrochemical sensor for the specific marker of Glycyrrhiza glabra L. was developed in this work. To achieve simultaneous detection of two analytes on one sensor, we constructed a double template molecular imprinted electrochemical sensor with glabridin (GLA) and isoliquiritin (ISL) as templates. Further, Ferrocene/ZIF-8 (Fc/ZIF-8) composites were prepared via a one-pot solvothermal reaction and coated on the surface of a glassy carbon electrode (GCE), and the oxidation of Fc was presented as the internal reference signal. Nitrogen-doped carbon (NOC) with high conductivity was further loaded on the modified GCE. Based on theoretical exploration and computer directional simulation of density functional theory (DFT), the optimal functional monomer and the best ratio of double template molecules to functional monomer were screened. Under optimal conditions, the sensor produced electrochemical curves when exposed to a solution containing GLA and ISL. As the concentration of GLA and ISL increased, the peak current intensity of GLA and ISL (IGLA and IISL) also increased, while the peak current intensity of Fc (as a reference signal) remained relatively constant. The values of IGLA/IFc and IISL/IFc showed excellent linear relationships with GLA and ISL concentrations in the range of 0.1–160 μM and 0.5–150 μM, respectively. The detection limits were 0.052 μM and 0.27 μM (S/N = 3), respectively. Due to the imprinting effect of MIP and the existence of a reference signal, the sensor exhibited excellent selectivity and anti-interference ability and was successfully applied to the quality evaluation of Glycyrrhiza glabra L.

In vitro and in vivo enhancement effect of glabridin on the antibacterial activity of colistin, against multidrug resistant Escherichia coli strains

BackgroundThe increase in antimicrobial resistance leads to complications in treatments, prolonged hospitalization, and increased mortality. Glabridin (GLA) is a hydroxyisoflavan from Glycyrrhiza glabra L. that exhibits multiple pharmacological activities. Colistin (COL), a last-resort antibiotic, is increasingly being used in clinic against Gram-negative bacteria. Previous reports have shown that GLA is able to sensitize first line antibiotics such as norfloxacin and vancomycin on Staphylococcus aureus, implying that the use of GLA as an antibiotic adjuvant is a promising strategy for addressing the issue of drug resistance. However, the adjuvant effect on other antibiotics, especially COL, on Gram-negative bacteria such as Escherichia coli has not been studied. PurposeThe objective of our study was to investigate the targets of GLA and the synergistic effect of GLA and COL in E. coli, and to provide further evidence for the use of GLA as an antibiotic adjuvant to alleviate the problem of drug resistance. MethodsWe first investigated the interaction between GLA and enoyl-acyl carrier protein reductase, also called "FabI", through enzyme inhibition assay, differential scanning fluorimetry, isothermal titration calorimetry and molecular docking assay. We tested the transmembrane capacity of GLA on its own and combined it with several antibiotics. The antimicrobial activities of GLA and COL were evaluated against six different susceptible and resistant E. coli in vitro. Their interactions were analyzed using checkerboard assay, time-kill curve and CompuSyn software. A series of sensitivity tests was conducted in E. coli overexpressing the fabI gene. The development of COL resistance in the presence of GLA was tested. The antimicrobial efficacy of GLA and COL in a mouse model of urinary tract infection was assessed. The anti-biofilm effects of GLA and COL were investigated. ResultsIn this study, enzyme kinetic analysis and thermal analysis provided evidence for the interaction between GLA and FabI in E. coli. GLA enhanced the antimicrobial effect of COL and synergistically suppressed six different susceptible and resistant E. coli with COL. Overexpression experiments showed that targeted inhibition of FabI was a key mechanism by which GLA synergistically enhanced COL activity. The combination of GLA and COL slowed the development of COL resistance in E. coli. Combined GLA and COL treatment significantly reduced bacterial load and mitigated urinary tract injury in a mouse model of E. coli urinary tract infection. Additionally, GLA + COL inhibited the formation and eradication of biofilms and the synthesis of curli. ConclusionOur findings indicate that GLA synergistically enhances antimicrobial activities of COL by targeting inhibition of FabI in E. coli. GLA is expected to continue to be developed as an antibiotic adjuvant to address drug resistance issues.

Fabrication of sulfobutylether-β-cyclodextrin/glabridin inclusion complex for promoting bioactivities.

As the main active compound of Glycyrrhiza glabra L., glabridin (GLD) has been shown to have multiple bioactivities, whereas the clinical application of GLD is restricted by its low water solubility. In this study, GLD was encapsulated into a sulfobutylether-β-cyclodextrin (SBE-β-CD)-based inclusion complex (SBE-β-CD/GLD) by the freeze-drying method. The materials characterization, antibacterial activity, stimulated cellular behavior and in vivo full-thickness diabetic wound healing ability of the hydrogels were assessed and analyzed. The successful encapsulation of the inclusion complex was confirmed by ultraviolet (UV) visible spectroscopy, Fourier transform infrared (FT-IR), X-ray diffractometer (XRD), scanning electron microscope (SEM), and nuclear magnetic resonance (NMR). SBE-β-CD as an excipient significantly enhances the water solubility of GLD, and SBE-β-CD/GLD showed excellent biocompatibility on human vascular endothelial cells (HUVECs) and erythrocytes. The SBE-β-CD/GLD inclusion complex exerted a pronounced antibacterial activity on Staphylococcus aureus and Escherichia coli in vitro. The SBE-β-CD/GLD inclusion complex markedly enhanced the antioxidant activity compared with free GLD. The SBE-β-CD/GLD inclusion complex potently accelerates the healing of full-thickness skin defects by inhibiting inflammation. The outcomes suggest that SBE-β-CD could be used as a promising drug delivery system for the clinical application of GLD.

A novel sprayable thermosensitive hydrogel containing a sulfobutylether-β-cyclodextrin/glabridin inclusion complex promotes wound healing

This study concentrated on developing a novel sprayable hydrogel by the combination of a thermosensitive hydrogel (Pluronic F-127, PF-127) and an inclusion complex of glabridin (GLD) and sulfobutylether-β-cyclodextrin (SBE-β-CD). GLD was encapsulated into SBE-β-CD by the freeze-drying method. The successful encapsulation of the inclusion complex was verified by Fourier transform infrared (FT-IR), X-ray diffractometer (XRD), scanning electron microscope (SEM), and nuclear magnetic resonance spectroscopy (NMR). The prepared GLD/SBE-β-CD inclusion complex exhibited 93.24%～96.46% encapsulation efficiency and 11.24%～11.93% loading capacity, and GLD/SBE-β-CD showed excellent biocompatibility on human vascular endothelial cells (HUVECs) and erythrocytes. GLD/SBE-β-CD inclusion complex exerts higher antioxidant and antibacterial activity than GLD alone. The GLD/SBE-β-CD inclusion complex was well dispersed within 20% PF-127 solution to form the PF-127/GLD/SBE-β-CD hydrogel. Introducing the inclusion complex into the PF-127 hydrogel did not influence its loose and porous structure, while PF-127/GLD/SBE-β-CD hydrogel demonstrated controlled GLD release in a sustained manner. The full-thickness skin wound model showed that the PF-127/GLD/SBE-β-CD hydrogel accelerated the healing of traumatic skin defects. In one aspect, the porous and biocompatible structure of the hydrogel provides favorable conditions for skin cell adhesion and proliferation. In another respect, GLD in therapeutic hydrogel markedly promotes the angiogenesis of endothelial cells, and the migration of keratinocytes. It also presents excellent antibacterial properties in wound surface. Taken together, this work established a novel sprayable hydrogel (PF-127/GLD/SBE-β-CD) and proved that it is an effective strategy for traumatic wound healing.

Prenylated flavonoid fractions from Glycyrrhiza glabra alleviate insulin resistance in HepG2 cells by regulating the ERK/IRS-1 and PI3K/Akt signaling pathways.

Insulin resistance (IR) is a key factor in the pathogenesis of disrupted glucose metabolism. Although the extract of Glycyrrhiza glabra has shown significant hypoglycemic activity, its bioactive components remain to be identified, and their mechanisms of action, especially on hepatocyte glucose metabolism, are yet to be explored. In the present study, the primary compounds from Glycyrrhiza glabra [named prenylated flavonoid fractions (PFFs)] have been identified and their chemical structures have been elucidated. The therapeutic effects of PFFs extracted from G. glabra on glucose metabolism disorders and IR in high insulin-induced insulin-resistant HepG2 (IR-HepG2) cells have been determined. Glabridin (GLD) was used as a control. The results indicated that, similar to GLD, PFFs increased glucose consumption, glucose uptake, and translocation of glucose transporter 4 to the plasma membrane in IR-HepG2 cells. In addition, they enhanced the activities of glycogen synthase, glucokinase, and pyruvate kinase, while reducing the activities of phosphoenolpyruvate carboxykinase and glucose-6-phosphatase. Furthermore, they activated the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) pathway and suppressed the extracellular signal-regulated kinase/insulin receptor substrate-1 (ERK/IRS-1) pathway. These findings suggest that, similar to GLD, PFFs can alleviate impaired glucose metabolism and alleviate IR in IR-HepG2 cells.Please check and confirm that the authors and their respective affiliations have been correctly identified and amend if necessary.The authors and their affiliations have been confirmed as correct.

Nutrient distribution in various tissues of Licorice (Glycyrrhiza glabra L.) and the influence of soil fertility on the levels of its bioactive compounds

This study aimed to optimize the production of licorice (Glycyrrhiza glabra L.) in field conditions using two licorice ecotypes and various types of nutrient sources. Licorice yield, leaf and root nutrient content, and its bioactive compounds were assessed. Mycorrhiza inoculation resulted in the highest rhizome dry weight in the Lalehzar (101.3 g) and Kermanshah (395.6 g) ecotypes in the first and second years, respectively. Rhizome dry weight was higher than the roots in both ecotypes. Two years old Kermanshah ecotype exhibited the highest root dry weight by using urea. The harvest index increased in Lalehzar ecotype by application of vermicompost in the first year and cow manure coupled with plant growth-promoting bacteria (PGPB) in the second year. Nitrogen content in leaves and roots significantly increased in the Kermanshah ecotype using cow manure and PGPB. Application of mycorrhiza (in Lalehzar ecotype) and cow manure combined with urea (in Kermanshah ecotype) led to leaf phosphorus (P) content improvement. The highest root P content in Lalehzar and Kermanshah ecotypes achieved by using cow manure and urea, respectively. Fertilization by urea and mycorrhiza led to higher leaf potassium (K) content in Kermanshah and Lalehzar, respectively, while urea yielded the highest root K content in the Kermanshah ecotype. Root glycyrrhizic acid (GA) content peaked in the Kermanshah ecotype with cow manure and PGPB (138 and 372.8 mg g-1 DW in the first and second years, respectively). Rhizome GA content performed better in the Lalehzar ecotype using cow manure and PGPB (191.34 mg g-1 DW, first year) and in the Kermanshah ecotype with cow manure and urea (239.62 mg g-1 DW, second year). Fertilizers had not significant effect on glabridin (GL) content. Notably, GA and GL exhibited a negative correlation with potassium and nitrogen. This study highlights the importance of balanced nutrient management for licorice cultivation.

Optimization of ultrasound-assisted extraction of glycyrrhizic acid and glabridin from Glycyrrhiza glabra L. using response surface methodology and development of a green analytical method

In this study, ultrasound assisted extraction (UAE) were used to investigate the extraction of glycyrrhizic acid (GA) and glabridin (GD) simultaneously from Glycyrrhiza glabra L. and a green HPLC analytical approach for determining GA and GD was developed. Extraction pocess were optimizing by Response surface methodology (RSM) utilizing Box-Behnken design (BBD). According to the consequences, the ideal extraction situations were: 64% (v/v) ethanol concentration, 22 mL/g liquid-solid ratio, 51 °C and 31 min. Under these conditions, the yields of GA and GD were 2.806 ± 0.107% and 0.252 ± 0.026%, respectively, and the actual experimental extraction values were fundamentally the same as the anticipated values. Meanwhile, the effects of UAE, maceration (MAC) and heat-reflux extraction (HRE) on yeild were assessed, and the UAE possessed highest yields. A green HPLC approach was created to analyze GA and GD with combinations of ethanol and a 0.1% (v/v) trifluoroacetic acid mobile phase (following the gradient elution method). The method validated based on the guidelines of the International Conference on Harmonization (ICH) and the result indicated the method was precise, stable, reliable and valuable, could be used to analyze GA and GD from Glycyrrhiza glabra L.

Preparation of the Chitosan/Poly-γ-Glutamic Acid/Glabrid in Hybrid Nanoparticles and Study on its Releasing Property.

The aim of this study was to encapsulate glabridin (GB) into nanoparticles, prepared by an ionic-gelation method blended with chitosan (CS) and poly-γ-glutamic acid (γ-PGA) to address the issue of poor stability and low water solubility of glabridin. The physicochemical properties of nanoparticles were investigated by transmission electron microscope (TEM), dynamic light scattering (DLS) and fourier-transform infrared (FT-IR) spectroscopy. FT-IR results indicated that the spontaneous interaction between CS, γ-PGA and GB can form a cross linked network-structure, leading to the spontaneous formation of nanoparticles. Morphology of the complex particles was nano-scale spherical shape. Furthermore, particle size was decreased according to the decrease of γ-PGA contents and CS, accompanying with the increase of mixed solution transmittance. The mγ-PGA : mGB = 1: 1 and mCS: (mγ-PGA + mGB) =1: 1 were considered to be a proper preparation condition of CS/γ-PGA/GB hybrid nanoparticles, which produced the smaller nanoparticles with the satisfactory encapsulation efficiency (EE), loading content (LC) and sustained GB release. With the increase of pH values, the potential, EE, and LC decreased gradually, while the particle size increased. The nanoparticles prepared with higher molecular weight γ-PGA had larger particle size and less loading capacity on GB. Additionally, moderate weight ratio of CS/γ-PGA/GB, low pH, and high molecular weight of γ-PGA were favorable for sustained release. It can be concluded that the physicochemical properties of nanoparticles and GB release behaviors were affected by several factors including the weight ratio of CS/γ-PGA/GB, pHvalues, and γ-PGA molecular weight (MW). Nanoencapsulation using CS, γ-PGA and GB has a potential application for the development of functional cosmetic products with skin-whitening effect.

Glabridin ameliorates intracellular events caused by palmitic acid and alcohol in mouse hepatocytes and fast food diet and alcohol -induced steatohepatitis and fibrosis in C57BL/6J mice model.

Steatohepatitis is a significant risk factor for end-stage liver disease. In this study, the therapeutic potential of Glabridin (GBD), an isoflavan derived from Glycyrrhiza glabra, is investigated in in-vitro and in-vivo models against palmitic acid (PA) or fast food (FF) diet+alcohol (EtOH). Mouse hepatocytes (AML-12cells) were treated with PA; 250μM+EtOH; 250μM±GBD (10μM and 25μM) for 24h. C57BL/6J mice fed with standard chow (SC) diet, fast food (FF) diet+intermittent oral ingestion of EtOH (10-50%v/v)±GBD (20mg/kg and 40mg/kg) for eight (8) weeks, were analyzed for histological features of steatohepatitis and fibrosis, biochemical indexes, and protein and gene expression studies related to oxidative stress, inflammation, lipogenesis, fibrosis, and apoptosis. GBD therapy considerably reduced intracellular events in AML-12cells exposed to PA+EtOH. GBD treatments significantly improved body metrics, biochemical indexes, and histological features in C57BL/6J mice compared to FF+EtOH. Moreover, protein and gene expression investigations revealed a strong therapeutic effects on oxidative stress, inflammation, steatosis, fibrosis, and apoptosis -related molecular signaling cascades. In conclusion, these findings suggest that GBD has a strong therapeutic potential to be developed as anti-steatohepatitis/fibrosis medicine.

Natural antibacterial agent-based nanoparticles for effective treatment of intracellular MRSA infection.

Intracellular MRSA is extremely difficult to eradicate by traditional antibiotics, leading to infection dissemination and drug resistance. A general lack of facile and long-term strategies to effectively eliminate intracellular MRSA. In this study, glabridin (GLA)-loaded pH-responsive nanoparticles (NPs) were constructed using cinnamaldehyde (CA)-dextran conjugates as carriers. These NPs targeted infected macrophages/MRSA via dextran mediation and effectively accumulated at the MRSA infection site. The NPs were then destabilized in response to the low pH of the lysosomes, which triggered the release of CA and GLA. The released CA downregulated the expression of cytotoxic pore-forming toxins, thereby decreasing the damage of macrophage and risk of the intracellular bacterial dissemination. Meanwhile, GLA could rapidly kill intracellularly entrapped MRSA with a low possibility of developing resistance. Using a specific combination of the natural antibacterial agents CA and GLA, NPs effectively eradicated intracellular MRSA with low toxicity to normal tissues in a MRSA-induced peritonitis model. This strategy presents a potential alternative for enhancing intracellular MRSA therapy, particularly for repeated and long-term clinical applications. STATEMENT OF SIGNIFICANCE: Intracellular MRSA infections are a growing threat to public health, and there is a general lack of a facile strategy for efficiently eliminating intracellular MRSA while reducing the ever-increasing drug resistance. In this study, pH-responsive and macrophage/MRSA-targeting nanoparticles were prepared by conjugating the phytochemical cinnamaldehyde to dextran to encapsulate the natural antibacterial agent glabridin. Using a combination of traditional Chinese medicine, the NPs significantly increased drug accumulation in MRSA and showed superior intracellular and extracellular bactericidal activity. Importantly, the NPs can inhibit potential intracellular bacteria dissemination and reduce the development of drug resistance, thus allowing for repeated treatment. Natural antibacterial agent-based drug delivery systems are an attractive alternative for facilitating the clinical treatment of intracellular MRSA infections.

Evaluation of possible protective role of glabridin against gentamicin-instigated nephrotoxicity via attenuation of oxidative stress

Glabridin (GB) is a natural dietary flavonoid of plant origin with excellent antioxidant properties. Gentamicin (GM) is an aminoglycoside antibiotic that can potentially cause renal toxicity. This investigation was intended to elucidate the attenuative effects of GB against GM-instigated nephrotoxicity. The entire experiment was carried out for a week on adult male albino rats (n = 24), which were randomly separated into 4 comparable groups that included Group I (0.9% physiological saline), group II (80 mg/kg of GM i.p.), group III (80 mg/kg; 50 mg/kg of GM + GB respectively), and group IV (50 mg/kg of GB orally). Biochemical analysis of antioxidant enzymes i.e., superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), glutathione reductase (GSR), Glutathione-S-transferase (GST), glutathione (GSH), reactive oxygen species (ROS), hydrogen peroxide (H2O2), thiobarbituric acid reactive substance (TBARS) level, renal serum neutrophil gelatinase-associated lipocalin (NGAL) as well as kidney injury molecule-1 (KIM-1) along with urinary profile (Albumin, creatinine, urea, urinary protein, urobilinogen, and creatinine clearance), inflammatory markers (nuclear factor (NF)-κB, interleukin (IL)-1β, tumor necrosis factor (TNF)-α, interleukin (IL)-6 as well as cyclo-oxygenase (COX)-2), apoptotic markers (Bax, Caspase-3 as well as Caspase-9), anti-apoptotic markers (Bcl-2) as well as histopathology of renal tissues, were analyzed. GM significantly reduced antioxidant enzymes activity, on the other hand, GM treatment substantially elevated the concentration of ROS, H2O2, TBARS, as well as induced abnormality in renal serum markers and urine profile, inflammatory markers, pro-apoptotic markers whereas, declined the level of anti-apoptotic markers and induced substantial histopathological damages. However, GB treatment potentially alleviated damages caused by GM. Conclusively, the intriguing outcomes of the investigation propose that GB effectively protects against GM-prompted nephrotoxicity, which may indicate its anti-oxidant, anti-apoptotic as well as anti-inflammatory potential.

Glabridin ameliorates DNFB induced atopic dermatitis by suppressing MAPK/NF κB signaling pathways in mice

Purpose: To investigate the anti-inflammatory mechanism of action of glabridin (GBD) isolated from glycyrrhizae radix et rhizoma (Glycyrrhiza glabra L.) using atopic dermatitis (AD) mouse model. Methods: Nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways were investigated. The dorsal skin and serum of 2,4-dinitrofluorobenzene (DNFB)-induced AD mice were used to determine the levels of various inflammatory cytokines, including interferon (IFN)-γ, tumor necrosis factor (TNF)-α, interleukin (IL)-4, IL-5, IL-6, IL-13, and immunoglobulin E (IgE) by enzyme-linked immunosorbent assay (ELISA). The relative levels of inflammation-associated mRNA and signaling pathways were determined by real time-polymerase chain reaction (RT-PCR) and western blotting, respectively. Hematoxylin and eosin (H&E) staining was used to assess the effect of GBD on tissue thickening and inflammatory cell infiltration in mice with AD. Results: Glabridin significantly relieved dorsal skin thickening, scabbing, and bleeding, and reduced the infiltration of inflammatory cells in mice with AD (p < 0.05). The levels of IFN-γ, TNF-α, IL-4, IL-5, IL-6, IL-13, and IgE were significantly reduced (p < 0.05 or 0.01). Moreover, the relative levels of IL-6 and IFN-γ mRNA showed a significant decrease (p < 0.01). Furthermore, GBD inhibited phosphorylation of MAPK signaling pathway and activation of NF-κB (p < 0.05 or 0.01). Conclusion: Glabridin exerts an inhibitory effect on AD by blocking MAPK and NF-κB signaling pathways. This finding highlights the relationship between traditional Chinese medicine and modern AD therapeutic methods, which should be further investigated for its potential to be developed as an external anti-AD medicine.

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.

Investigation of the Effects of Glabridin on the Proliferation, Apoptosis, and Migration of the Human Colon Cancer Cell Lines SW480 and SW620 and Its Mechanism Based on Reverse Virtual Screening and Proteomics.

Colon cancer is a relatively common malignant tumor of the digestive tract. Currently, most colon cancers originate from adenoma carcinogenesis. By screening various licorice flavonoids with anticancer effects, we found that glabridin (GBN) has a prominent anticolon cancer effect. First, we initially explored whether GBN can inhibit proliferation, migration, and invasion and induce apoptosis in SW480 and SW620 cells. Next, we exploited reverse virtual and proteomics technologies to screen out closely related target pathways on the basis of a drug and target database. At the same time, we constructed the structure of the GBN target pathway in colon cancer. We predicted that GBN can regulate the phosphatidylinositol 3-kinase (PI3K)-protein kinase B (AKT)-mammalian target of the rapamycin pathway (mTOR) pathway to fight colon cancer. Finally, through Western blot analysis and qRT-PCR, we verified that the expression levels of the PI3K, AKT, and mTOR proteins and genes in this pathway were significantly reduced after GBN administration. In short, the promising discovery of the anticolon cancer mechanism of GBN provides a reliable experimental basis for subsequent new drug development.

Glabridin inhibits urothelial bladder carcinoma cell growth in vitro and in vivo by inducing cell apoptosis and cell cycle arrest.

Glabridin (GLA) has a variety of biological activities and therapeutic effects in cancers. Whereas the effect of GLA on urothelial bladder carcinoma (UBC) cells and its underlying mechanisms remain unknown. The study revealed the effect of GLA on UBC and the potential mechanism of inducing cell apoptosis in vivo and in vitro. After treated with different concentrations of GLA, the cell activity decreased in a time- and dose-dependent manner. The IC50 values of BIU-87 and EJ cells at 48 h were 6.02 μg/ml (18.6 μm) and 4.36 μg/ml(13.4μm), respectively. Additionally, GLA-induced apoptosis and cycle arrest of BIU-87 and EJ cells in G2 phase. Furthermore, wound healing experiments showed that GLA significantly reduced the migration activities of BIU-87 and EJ cells. Mechanically, GLA obviously increased the expression of BIM, BAK1, and CYCS in both mRNA and protein levels, which led to the activation of the endogenous apoptotic pathway. Finally, GLA remarkably inhibited the growth of UBC tumors in vivo. In summary, GLA inhibited UBC cells growth in vitro and in vivo by inducing cell apoptosis and cell cycle arrest, highlighting that GLA could be utilized as a component to design a novel anti-UBC drug.

Physicochemical characteristics and in vitro bioavailability of licorice (Glycyrrhiza glabra L.) extract complexed using cyclic glucans

Licorice extract (LE), whose main ingredient is glabridin (GL), have various biological properties such as antioxidant and anticancer activities, however, their low solubility and bioavailability limit their application in the pharmaceutical and food industries. In this study, inclusion complexes (ICs) were developed using β-cyclodextrin (CD), 2-hydroxypropyl-β-cyclodextrin (HP), and cycloamylose (CA) to overcome the application limits of LE. The IC with cyclic glucans successfully enhanced the phase solubility of LE, and the stoichiometry of the complexes was investigated. After in vitro digestion, the bioaccessibility (% retention) of LE increased significantly in the IC samples, particularly with CA, compared to free LE. In vitro bioavailability, which was assessed using the results of bioaccessibility via the simulated gastrointestinal tract (GIT) model and permeability via Caco-2 monolayer assay, increased 2.5, 2.3, and 4.7-fold in the CD, HP, and CA ICs, respectively. This study provides a promising strategy to overcome the application limits of LE in various industries.

Ultrasound-assisted deep eutectic solvents extraction of glabridin and isoliquiritigenin from Glycyrrhiza glabra: Optimization, extraction mechanism and in vitro bioactivities

Licorice (Glycyrrhiza glabra) is extensively used owing to the superior pharmacological effects. However, its maximum application potential has not been fully exploited due to the limitation of currently available extraction solvent and methods. In this study, an eco-friendly deep eutectic solvent (NADESs) based ultrasound-assisted extraction (DES-UAE) method was applied to prepare licorice extracts. The DES-UAE using choline chloride and lactic acid as solvent was optimized and modeled by using response surface methodology to maximize the extraction yields of glabridin (GLA) and isoliquiritigenin (ISL). The optimized extracts possessed higher contents of GLA and ISL than available extraction methods, and the enriched products showed superior pharmacological activities in vitro. Furthermore, scanning electron microscopy (SEM) and molecular dynamic simulation analyses were performed to deeply investigate the interaction between solvent and targeted compounds. This study not only provides an eco-friendly method for high-efficient extraction of GLA and ISL from licorice but also illustrates the mechanism of the increased extraction efficacy, which may contribute to the application of licorice and deep insight into extraction mechanism using DES.

The role of Glabridin in antifungal and anti-inflammation effects in Aspergillus fumigatus keratitis

PurposeTo investigate the effect of Glabridin (GLD) in Aspergillus fumigatus keratitis and its associated mechanisms. MethodsAspergillus fumigatus (A. fumigatus) conidia was inoculated in 96-well plate, and minimal inhibitory concentration (MIC) and biofilm formation ability were evaluated after GLD treatment. Spore adhesion ability was evaluated in conidia infected human corneal epithelial cells (HCECs). Keratitis mouse model was created by corneal intrastromal injection with A. fumigatus conidia, and GLD treatment started at the day after infection. The number of fungal colonies was calculated by plate count, and degree of corneal inflammation was assessed by clinical score. Flow cytometry, myeloperoxidase (MPO), and immunofluorescence staining (IFS) experiments were used to assess neutrophil infiltrations. PCR, ELISA and Western blot were conducted to determine levels of TLR4, Dectin-1 as well as downstream inflammatory factors. ResultsGLD treatment suppressed the proliferation, biofilm formation abilities and adhesive capability of A. fumigatus. In mice upon A. fumigatus infection, treatment of GLD showed significantly decreased severity of corneal inflammation, reduced number of A. fumigatus in cornea, and suppressed neutrophil infiltration in cornea. GLD treatment obviously inhibited mRNA and protein levels of Dectin-1, TLR4 and proinflammatory mediators such as IL-1β, HMGB1, and TNF-α in mice corneas compared to the control group. ConclusionGLD has antifungal and anti-inflammatory effects in fungal keratitis through suppressing A. fumigatus proliferation and alleviating neutrophil infiltration, and repressing the expression of TLR4, Dectin-1 and proinflammatory mediators.

Effect of Glabridin on Microvascular Permeability of Plasma Proteins Induced by Carrageenan

In the present study, investigate the anti-inflammatory effects of glabridin (GLA) in the carrageenan-induced paw edema test of rats. Inflammation is an answer to the body's immune response to various stimuli such as physical trauma, various antigens, chemicals, microorganisms, radiation-damaged tissues. The cause of this edema is the increase of vascular permeability, an increase in local blood flow, as well as the penetration of neutrophils and macrophages into the inflamed tissue. The current study aimed to determine the mechanism of microvascular leakage on carrageenan (CAR)-induced paw edema of GLA. Therefore, 10, 20 and 40 mg / kg doses of GLA were given intraperitoneal 3 days before intraplantar administration of CAR by using Evans blue (EB) method and by measuring paw thickness with electronic digital calipers. As a result, GLA inhibited both edema and microvascular leak. The results of our study suggest that pretreat-GLA to CAR-induced paw edema of rats via anti-inflammatory potential through inhibition of parameters such as microvascular escape and anti-edematous effect. These findings may be a new treatment of inflammation by anti-protein leakage of GLA.