Review on the Diverse Biological Effects of Glabridin

Mapping the future: bibliometric insights into ferroptosis and diabetic nephropathy

Background

Diabetic nephropathy (DN), a leading cause of end-stage renal disease, exerts a substantial burden on healthcare systems globally. Emerging evidence highlights ferroptosis - an iron-dependent form of cell death driven by lipid peroxidation and glutathione depletion - as a critical contributor to DN progression via oxidative stress, tubular injury, and glomerular dysfunction. Despite increasing research interest, a comprehensive synthesis of research trends and mechanistic insights is lacking.

Objective

This study integrated bibliometric analysis with a mechanistic review to map the evolving ferroptosis landscape in DN, identify research hotspots, and propose future directions for therapeutic development.

Methods

In total, 86 publications (2018-2023) were retrieved from the Web of Science Core Collection and analyzed using CiteSpace and VOSviewer. Co-occurrence networks, citation trends, and keyword bursts were examined to delineate global contributions, collaborative networks, and emerging themes.

Results

Annual publication numbers surged 12-fold after 2020, with China contributing the highest proportion (60.4%), and led by institutions such as Zhengzhou University. The United States of America and Germany showed high centrality in collaborative networks. Key research themes included glutathione peroxidase 4 (GPX4)-mediated antioxidant defenses, acyl-CoA synthetase long-chain family member 4 (ACSL4)-mediated lipid remodeling, and iron dysregulation. Frontiers in Endocrinology (nine articles) and Free Radical Biology and Medicine (highest citation count: 171) emerged as pivotal publication platforms. Mechanistic analyses identified three ferroptosis defense axes (GPX4, FSP1/CoQ10, and GCH1/BH4) and cell type-specific vulnerabilities in tubular, podocyte, and endothelial cells. Preclinical agents, including ginkgolide B (GB) and dapagliflozin, effectively restored iron homeostasis and attenuated oxidative damage.

Conclusion

Ferroptosis is a promising therapeutic target for DN, yet its clinical translation remains in its infancy. Future efforts should prioritize large-scale clinical trials, single-cell mechanistic profiling, and interdisciplinary integration to bridge molecular insights with precision therapies. This study provides a roadmap for advancing ferroptosis-targeted interventions for DN, emphasizing global collaborations and biomarker-driven strategies.

Glabridin restore the sensitivity of colistin against mcr-1-positive Escherichia coli by polypharmacology mechanism

The clinical effectiveness of colistin against multidrug-resistant Gram-negative pathogen infections has been threatened by the emergence of the plasmid-mediated colistin-resistant gene mcr-1. This development underscores the urgent need for innovative therapeutic strategies that target resistance mechanisms. In this study, we demonstrated that glabridin can restore the sensitivity of colistin to mcr-1-positive Escherichia coli (E. coli) and exhibits a reduced propensity for resistance development. Our investigation into the underlying mechanisms revealed that glabridin may re-sensitize E. coli to colistin by targeting MCR-1 to inhibit its activity, regulating the expression of mcr-1, and restoring the Zeta potential at the cell membrane surface. Furthermore, the combination of glabridin and colistin increased bacterial membrane permeability, decreased membrane fluidity, disrupted transmembrane proton motive force (PMF), reduced the ratios of NAD+/NADH and FAD/FADH2, facilitated the tricarboxylic acid (TCA) cycle, and led to the accumulation of reactive oxygen species (ROS) in E. coli cells, ultimately resulting in bacterial death. In animal models, glabridin significantly enhanced the efficacy of colistin in treating E. coli infections. Our findings suggest that glabridin is a promising polypharmacological antibiotic adjuvant for addressing infections associated with colistin-resistant E. coli.

Structural and anti-ovarian cancer insights into the immunoglobulin G-glabridin nanocomplex

In this study, the formation of the immunoglobulin G-glabridin (IgG-GB) complex and nanocomplex was analyzed by assessing the structure, stability, solubility, and anticancer effects against the human epithelial ovarian cancer cell line, SKOV3. The hydrodynamic sizes of the prepared IgG-GB nanocomplex were 190.1 ± 25.68 nm (PDI: 0.19 ± 0.02), and the solubility levels of GB in the free and nanoformulated forms were 97.28 μg/mL and 368.95 ± 59.63 μg/mL, respectively. Additionally, the IgG-GB nanocomplex exhibited a slower and more sustained release of GB in a pH-sensitive manner. Spectroscopic measurements indicated logKb values of 4.01 and 4.66 for the IgG-GB complex and the IgG-GB nanocomplex, respectively. Furthermore, the main reaction type between IgG and GB was found to be hydrophobic forces, which led to the partial folding of IgG and nanoformulated IgG. Cellular assays demonstrated that the IC50 concentrations of GB, the IgG-GB complex, and the IgG-GB nanocomplex in ovarian cancer SKOV3 cells were 10.74, 10.05, and 6.39 μM, respectively, while these amounts were > 77.84 μM in normal epithelial FHC cells. Moreover, the IgG-GB nanocomplex resulted in increased membrane leakage, mitochondrial dysfunction, and upregulation of Bax/Bcl-2 and caspase-3, along with caspase-3 activity. In conclusion, an efficient IgG-GB nanocomplex was potentially prepared and developed as a selective anticancer system against ovarian cancer cells.

Glabridin Alleviates Oxidative Stress-Induced Osteoporosis by Targeting the Akt/NF-ĸB and Akt/GSK-3β Pathways

Diabetes-related osteoporosis has been known to be a consequence of oxidative stress caused by excessive reactive oxygen species (ROS) production in the tissues. Despite the increase in the number of individuals with diabetes-related osteoporosis year on year, there is still no effective drug that does not induce adverse side effects. Glabridin, which exerts hypoglycemic effects and possesses antioxidant properties, may have beneficial effects in the treatment of diabetes-related osteoporosis. In this study, we aimed to investigate the preventive effects of glabridin in counteracting oxidative stress-induced bone loss and its underlying mechanisms. A diabetic rat model was established by a single intraperitoneal injection of streptozotocin into male Wistar rats. The diabetic rats were orally gavaged daily with glabridin or glyburide for 8 weeks. The presence of diabetes significantly decreased the rats' tibia length, bone thickness, epiphyseal plate length, and collagen deposition compared to the control rats; in comparison, treatment with glabridin for 8 weeks significantly reversed these effects. In our in vitro study, the treatment of MC3T3-E1 preosteoblasts with glabridin up to 7.5 µM for 48 h showed no cytotoxic effect. However, pretreatment with glabridin significantly prevented oxidative stress-induced inhibition of cell proliferation. In addition, glabridin significantly diminished ROS production, restored antioxidant enzyme activity, and mitigated cellular apoptosis. These effects occurred by stimulating the phosphorylation of Akt, GSK-3β, and P65 NF-ĸB proteins. The above results show that glabridin alleviated oxidative stress-induced bone loss and osteoblast cell apoptosis by modulating the expression of the Akt/NF-ĸB and Akt/GSK-3β pathways.

Integrated Metabolomic and Transcriptomic Analysis Reveals the Pharmacological Effects and Differential Mechanisms of Isoflavone Biosynthesis in Four Species of Glycyrrhiza

Licorice (Glycyrrhiza L.) is a globally popular medicinal and edible plant, with nearly 30 species distributed across all continents. The usable part is primarily the root. To understand the metabolic differences among different Glycyrrhiza species, we selected four species and performed comprehensive analyses of their roots. Metabolomic profiling was conducted using UPLC-MS/MS and GC-MS, while transcriptomic analysis was carried out using RNA-sequencing. A total of 2716 metabolites were identified, including flavonoids (527 types) and terpenoids (251 types), among various other components. Subsequently, network pharmacology was employed to explore the medicinal value and potential pharmacological ingredients of these metabolites. Joint analysis of transcriptomic and metabolomic data revealed significant differences in differentially accumulated metabolites (DAMs) and differentially expressed genes (DEGs) in pairwise comparisons among the four species. These differences were primarily enriched in the isoflavone pathway. Further investigation into the regulatory mechanisms of isoflavone biosynthesis in different Glycyrrhiza species identified key genes and metabolites involved in isoflavone biosynthesis. Finally, we made reasonable predictions of the potential suitable habitats for the four Glycyrrhiza species, aiming to provide new insights for the development and utilization of licorice resources. The results of this study can serve as a basis for the development and utilization of licorice and for in-depth research on the regulation of isoflavone biosynthesis in licorice.

Comprehensive profiling of traditional herbomineral formulation Manasamitra vatakam in rat brain following oral administration and in-silico screening of the identified compound for anti-Alzheimer's activity

ETHNOPHARMACOLOGICAL RELEVANCE

Multi-targeted drug therapy has received substantial attention for the treatment of diseases of multifactorial origin, such as neurodegenerative diseases. Manasamitra vatakam (MMV) is a traditional Ayurvedic formulation used to improve cognitive impairment and mental illness. Here we have used a unique method for leveraging the barrier properties of the intestinal and blood-brain barrier (BBB) to screen and identify the bioactive molecules against Alzheimer's disease (AD). The current method exemplifies a facile method to expedite drug discovery from traditional formulations.

AIM OF THE STUDY

The present study aimed to identify the phytoconstituents of MMV that reach the brain tissue and to predict major bioactive constituents by computational docking studies.

MATERIALS AND METHODS

After oral administration of the formulation, brain samples from male Sprague Dawley rats were collected at different time intervals and analyzed by liquid chromatography-mass spectrometry (LC-MS) to identify the phytoconstituents. In silico molecular docking studies were carried out to analyze the binding affinity of the compounds to the target proteins of AD using Schrodinger Maestro. The molecular dynamic studies were carried out for all the docked complexes having higher docking scores.

RESULTS

34 phytoconstituents were identified by LC-MS analysis of brain homogenates. In the in silico docking study, the phytoconstituents chrysin, convolvin, rutin, galangin, palmatoside G, isoliquiritigenin, quercetin, and naringenin showed higher docking score against the target proteins of AD. These compounds may serve as the primary bioactive compounds responsible for the neuroprotective activity of the herbal formulation. Furthermore, molecular dynamic studies indicated that the galangin-acetylcholinesterase enzyme complex has the highest stability among these eight compounds.

CONCLUSION

The study, together with previous in vivo and in vitro efficacy results, suggests that BBB-permeable compounds with high binding affinities for the target proteins of AD might be responsible for the effectiveness of MMV against AD.

Emerging pharmacotherapies for obesity: A systematic review

The history of antiobesity pharmacotherapies is marked by disappointments, often entangled with societal pressure promoting weight loss and the prevailing conviction that excess body weight signifies a lack of willpower. However, categories of emerging pharmacotherapies generate hope to reduce obesity rates. This systematic review of phase 2 and phase 3 trials in adults with overweight/obesity investigates the effect of novel weight loss pharmacotherapies, compared to placebo/control or US Food and Drug Administration-approved weight loss medication, through searching Medline, Embase, and ClinicalTrials.gov (2012-2024). We identified 53 phase 3 and phase 2 trials, with 36 emerging antiobesity drugs or combinations thereof and 4 withdrawn or terminated trials. Oral semaglutide 50 mg is the only medication that has completed a phase 3 trial. There are 14 ongoing phase 3 trials on glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) (ecnoglutide, orforglipron, and TG103), GLP-1 RA/amylin agonist (CagriSema), GLP-1/glucagon RAs (mazdutide and survodutide), GLP-1/glucose-dependent insulinotropic polypeptide and glucagon RA (retatrutide), dapagliflozin, and the combination sibutramine/topiramate. Completed phase 2 trials on incretin-based therapies showed a mean percent weight loss of 7.4% to 24.2%. Almost half of the drugs undergoing phase 2 trials are incretin analogs. The obesity drug pipeline is expanding rapidly, with the most promising results reported with incretin analogs. Data on mortality and obesity-related complications, such as cardio-renal-metabolic events, are needed. Moreover, long-term follow-up data on the safety and efficacy of weight maintenance with novel obesity pharmacotherapies, along with studies focused on underrepresented populations, cost-effectiveness assessments, and drug availability, are needed to bridge the care gap for patients with obesity. SIGNIFICANCE STATEMENT: Obesity is the epidemic of the 21st century. Except for the newer injectable medications, drugs with suboptimal efficacy have been available in the clinician's armamentarium for weight management. However, emerging alternatives of novel agents and combinations populate the current obesity therapeutic pipeline. This systematic review identifies the state and mechanism of action of emerging pharmacotherapies undergoing or having completed phase 2 and phase 3 clinical trials. The information provided herein furthers the understanding of obesity management, implying direct clinical implications and stimulating research initiatives.

Glabridin exhibits potent inhibitory effects against Toxoplasma gondii in vitro and in vivo

BACKGROUND

Toxoplasma gondii is an obligate protozoan parasite capable of infecting a wide range of warm-blooded animals and humans. Current treatment options, primarily pyrimethamine and sulfadiazine, have limitations, such as high recurrence rates, long treatment durations, and limited effectiveness against T. gondii. There is an unmet need for novel, safe, low-toxicity, and highly effective treatments. This study aimed to evaluate the anti-T. gondii effects of glabridin, a natural compound derived from the roots of a widely used medicinal plant.

METHODS

The cytotoxicity of glabridin in Vero cells was assessed using a CCK-8 cell viability assay. Quantitative polymerase chain reaction (qPCR) targeting the Tg-529 gene was developed to quantify T. gondii and assess the inhibitory effects of glabridin on parasite proliferation. Ultrastructural changes in T. gondii after treatment were examined using electron microscopy. The levels of reactive oxygen species (ROS) and mitochondrial membrane potential (ΔΨm) were examined to assess the effects of glabridin on ROS levels and ΔΨm in T. gondii tachyzoites. Additionally, metabolomics and transcriptomics analyses were conducted to investigate the mechanisms underlying glabridin's anti-T. gondii effects.

RESULTS

Glabridin exhibited low toxicity to host cells and effectively inhibited T. gondii invasion and proliferation in vitro in a time-dependent manner. Glabridin-treated tachyzoites exhibited significant structural alterations, along with increased ROS production and a reduction in ΔΨm. Metabolomic analysis indicated that glabridin significantly affected amino acid metabolism pathways in T. gondii. In vivo, glabridin treatment significantly improved survival rates in T. gondii-infected BALB/c mice at a dosage of 100 mg/kg.

CONCLUSIONS

This study demonstrates that glabridin has potent anti-T. gondii effects in vitro and in vivo, likely through disruption of amino acid metabolism in the parasite. These findings highlight glabridin's potential as a promising therapeutic agent for toxoplasmosis.

The antitumor mechanisms of glabridin and drug delivery strategies for enhancing its bioavailability

Glabridin, a flavonoid derived from the plant Glycyrrhiza glabra, has garnered significant attention due to its diverse pharmacological effects, including antioxidant, antibacterial, anti-inflammatory, hypolipidemic, and hypoglycemic activities. Studies have shown that glabridin exhibits substantial antitumor activity by modulating the proliferation, apoptosis, metastasis, and invasion of cancer cells through the targeting of various signaling pathways, thus indicating its potential as a therapeutic agent for malignant tumors. To enhance its solubility, stability, and bioavailability, several drug delivery systems have been developed, including liposomes, cyclodextrin inclusion complexes, nanoparticles, and polymeric micelles. These de.livery systems have shown promise in preclinical studies but face challenges in clinical translation, such as issues with biocompatibility, delivery efficiency, and long-term stability. A comprehensive analysis of the antitumor mechanism of glabridin and its novel drug delivery system is still lacking. Therefore, the authors performed a comprehensive review of recent literature on the antitumor effects of glabridin and its novel drug delivery systems, covering the antitumor mechanism, action targets, and novel drug delivery systems, offering new theoretical insights and development directions for its further advancement and clinical application.

Glabridin Hypnosis in Zebrafish Larvae Is Associated With Effects on Multiple Anesthetic Target Receptors

BACKGROUND

R-Glabridin is a major flavonoid of licorice (Glycyrrhiza glabra) root and known to modulate GABAA receptors, which are targets of many clinical hypnotics. However, R-glabridin hypnotic activity has not been reported in animals.

METHODS

Inverted photomotor responses (IPMRs) were used to assess the hypnotic effects of natural R-glabridin and synthetic R/S-glabridin in wild-type zebrafish larvae and transgenic larvae lacking functional GABAA receptor β3 subunits (β30/0). Two-electrode voltage-clamp electrophysiology in Xenopus oocytes heterologously expressing ion channels quantified the effects of R-glabridin on wild-type and mutated human α1β3γ2L GABAA receptors, NR1B/NR2A N-methyl-D-aspatate (NMDA) receptors, and α4β2 neuronal nicotinic (nnACh) receptors.

RESULTS

IPMRs in wild-type zebrafish larvae identified R/S-glabridin as an inhibitor (IC50 = 7.5 µM; 95% confidence interval [CI], 5.9-9.3 µM) that was about half as potent as R-glabridin (IC50 = 4.4. µM; 95% CI, 3.6-5.4 µM). In β30/0 zebrafish larvae, R-glabridin inhibited IPMRs with IC50 = 7.5 µM (95% CI, 5.6-10.0 µM). Electrophysiologic studies revealed that R-glabridin directly activated and positively modulated α1β3γ2L GABAA receptors. Modulation was significantly reduced by α1L232W and β3N265M mutations in the β+/α- transmembrane intersubunit sites where etomidate binds, but not by 5 other point mutations in 4 other transmembrane modulator binding sites. NMDA and nnACh receptors were inhibited by R-glabridin.

DISCUSSION/CONCLUSIONS

Our findings in zebrafish larvae indicate that IPMR inhibition by R-glabridin is more potent than S-glabridin and that β3-containing GABAA receptors contribute significantly to this behavioral effect. Molecular studies show that R-glabridin modulates at least 3 known anesthetic-sensitive ion channels, suggesting that it is a multimodal hypnotic.

Metabolomics analyses reveal the crucial role of ERK in regulating metabolic pathways associated with the proliferation of human cutaneous T-cell lymphoma cells treated with Glabridin

Cutaneous T-cell lymphomas (CTC) are a heterogeneous group of T-cell lymphoproliferative malignancies of the skin with limited treatment options, increased resistance and remission. Metabolic reprogramming is vital in orchestrating the uncontrolled growth and proliferation of cancer cells. Importantly, deregulated signalling plays a significant role in metabolic reprogramming. Considering the crucial role of metabolic reprogramming in cancer-cell growth and proliferation, target identification and the development of novel and multi-targeting agents are imperative. The present study explores the underlying mechanisms and metabolic signalling pathways associated with Glabridin mediated anti-cancer actions in CTCL. Our results show that Glabridin significantly inhibits the growth of CTCL cells through induction of programmed cell death (PCD) such as apoptosis, autophagy and necrosis. Interestingly, results further show that Glabridin induces PCD in CTCL cells by targeting MAPK signalling pathways, particularly the activation of ERK. Further, Glabridin also sensitized CTCL cells to the anti-cancer drug, bortezomib. Importantly, LC-MS-based metabolomics analyses further showed that Glabridin targeted multiple metabolites and metabolic pathways intricately involved in cancer cell growth and proliferation in an ERK-dependent fashion. Overall, our findings revealed that Glabridin induces PCD and attenuates the expression of regulatory proteins and metabolites involved in orchestrating the uncontrolled proliferation of CTCL cells through ERK activation. Therefore, Glabridin possesses important features of an ideal anti-cancer agent.

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.

Toxic Features and Metabolomic Intervention of Glabrene, an Impurity Found in the Pharmaceutical Product of Glabridin

Glabridin is a widely used product in the cosmetics and pharmaceutical industry, which is generally isolated and purified from Licorice (Glycyrrhiza glabra) extract in industrial production. It has wide clinical applications, but significant toxicity has also been reported. The purity of glabridin raw material is generally between 90% and 98%. We have identified a toxic impurity, glabrene, in the industrial product glabridin. Our investigation using an AB wild-type zebrafish toxicity test showed that glabrene has a significant lethal effect with an LC10 of 2.8 μM. Glabrene induced obvious malformation and disrupted cartilage development in zebrafish larvae. Furthermore, the compound significantly reduced larval mobility and caused damage to brain neural tissues. Metabolic pathway analysis and neurotransmitter quantification via ELISA indicated abnormal activation of the phenylalanine metabolic pathway, resulting in elevated dopamine and acetylcholine levels in vivo. These findings provide insights into the potential risks of glabrene contamination and offer a new reference point for enhancing safety measures and quality controls in licorice-derived products.

Investigation into the potential mechanism and therapeutic targets of Cangzhu Erchen decoction for the treatment of chronic obstructive pulmonary disease based on bioinformatics and network pharmacology

This study aimed to elucidate the molecular mechanisms underlying the therapeutic effects of Cangzhu Erchen decoction (CZECD) in the treatment of chronic obstructive pulmonary disease (COPD) using microarray analysis, network pharmacology, and molecular docking. The active components and candidate targets of CZECD were obtained using the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform and Swiss Target Prediction. COPD-related targets were collected from 5 databases. Access to drug-disease interface targets in the Venny platform. The Cytoscape program and the STRING database were used for protein-protein interaction analysis and subsequent core target screening. The DAVID database was used for Gene Ontology (GO) functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes enrichment pathway analysis, while AutoDockTools was used for molecular docking to confirm binding affinity between drugs and key targets. A total of 140 compounds from CZECD and 5100 COPD-related targets were identified. SRC, PIK3CA, STAT3, PIK3R1, AKT1, HSP90AA1, PIK3CB, GRB2, PIK3CD, and MAPK1 were identified as the major targets of CZECD in its anti-COPD activity. GO and Kyoto Encyclopedia of Genes and Genomes enrichment studies revealed that CZECD mainly affects biological processes such as protein phosphorylation, xenobiotic response, positive regulation of the MAPK cascade, and inflammatory responses. Cancer, PI3K/AKT, and MAPK were the key pathways mediating these effects. The positive association between the core targets and the compounds was further validated by molecular docking. CZECD exerts its therapeutic role in COPD mainly through multiple compounds, targets, and pathways.

Mechanism, Formulation, and Efficacy Evaluation of Natural Products for Skin Pigmentation Treatment

Skin pigmentation typically arises from the excessive secretion and accumulation of melanin, resulting in a darker complexion compared to normal skin. Currently, the local application of chemical drugs is a first-line strategy for pigmentation disorders, but the safety and efficacy of drugs still cannot meet clinical treatment needs. For long-term and safe medication, researchers have paid attention to natural products with higher biocompatibility. This article begins by examining the pathogenesis and treatment approaches of skin pigmentation diseases and summarizes the research progress and mechanism of natural products with lightening or whitening effects that are clinically common or experimentally proven. Moreover, we outline the novel formulations of natural products in treating pigmentation disorders, including liposomes, nanoparticles, microemulsions, microneedles, and tocosomes. Finally, the pharmacodynamic evaluation methods in the study of pigmentation disorder were first systematically analyzed. In brief, this review aims to collect natural products for skin pigmentation treatment and investigate their formulation design and efficacy evaluation to provide insights for the development of new products for this complex skin disease.

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

BACKGROUND

The 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.

PURPOSE

The 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.

METHODS

We 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.

RESULTS

In 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.

CONCLUSION

Our 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.

Subinhibitory concentrations of glabridin from Glycyrrhiza glabra L. reduce Listeria monocytogenes motility and hemolytic activity but do not exhibit antimicrobial activity

Increases in the virulence and survival of some pathogens in the presence of subinhibitory concentrations of antibiotics have been reported. However, research on the effects of subinhibitory concentrations of antimicrobial substances derived from traditional Chinese medicine on pathogens is still insufficient. Glabridin is a well-known active isoflavone found in licorice roots that possesses a wide range of biological activities. Therefore, in this study, Listeria monocytogenes (L. monocytogenes) exposed to subinhibitory concentrations of glabridin was used as the research object. The minimum inhibitory concentration (MIC) was determined for L. monocytogenes. We investigated the impacts of subinhibitory concentrations of glabridin on the morphology, motility, biofilm formation, adherence, and survival of L. monocytogenes. The results indicated that the MIC of glabridin for L. monocytogenes was 31.25 μg/mL. At 1/8, 1/4, or 1/2 of the MIC, glabridin did not affect the growth, morphology, flagellar production, or biofilm formation of L. monocytogenes. However, subinhibitory concentrations of glabridin inhibited bacterial swimming and swarming motility and decreased the hemolytic activity of L. monocytogenes. Glabridin reduced the hemolytic activity of L. monocytogenes culture supernatants. The results also showed that subinhibitory concentrations of glabridin had no toxic effect on RAW264.7 cells but decreased the intracellular growth of L. monocytogenes in RAW264.7 cells. Furthermore, subinhibitory concentrations of glabridin triggered ROS production but did not induce MET formation in macrophages. In addition, glabridin did not enhance the capacity of L. monocytogenes to trigger METs or the extracellular killing of macrophages by METs. Thus, we conclude that subinhibitory concentrations of glabridin reduce L. monocytogenes motility and hemolytic activity but do not exhibit antimicrobial activity. Glabridin could be an interesting food additive as a bacteriostatic agent with anti-Listeria activity.

Prenylated flavonoids from Sophora flavescens inhibit mushroom tyrosinase activity and modulate melanogenesis in murine melanoma cells and zebrafish

Background: Sophora flavescens, a traditional Chinese medicine for treating conditions associated with abnormal skin pigmentation, contains flavonoids with inhibitory effects on tyrosinase. However, their mechanisms of action and their modulatory effects on melanogenesis remain unclear. Methods: Herein, a group of prenylated flavonoids was identified from S. flavescens extracts and their inhibitory activities on mushroom tyrosinase were evaluated. The anti-melanogenesis effects of these prenylated flavonoids were investigated in cellular (with murine melanoma cells) and animal (with zebrafish) models. Results: Prenylated flavonoids including isoanhydroicaritin (IAI), kurarinone (KR), and sophoraflavanone G (SG) were the major active constituents in S. flavescens extracts with anti-tyrosinase activity (IC50 = 0.7, 7.1, and 6.7 μM, respectively). Enzyme kinetic assays showed that IAI, KR, and SG had a mixed type of tyrosinase inhibition, supported by data from computational docking. Notably, KR at concentrations of 5 and 10 μM enhanced intracellular tyrosinase activity and stimulated melanin production in B16F10 cells, whereas SG and IAI did not exhibit significant activity. Further studies with the zebrafish model showed that IAI (80 and 160 μM) inhibited melanin biosynthesis by about 30.0% while KR (20 μM) stimulated melanogenesis by 36.9%. Furthermore, a zebrafish depigmentation model supported the anti-melanogenesis effect of IAI (80 and 160 μM) by 33.0% and 34.4%, respectively. Conclusion: In summary, IAI was identified as a tyrosinase inhibitor with an anti-melanogenic effect and KR was an enhancer for melanin production in B16F10 cells and zebrafish. Findings from the current study suggest that IAI and KR from S. flavescens may exert contrasting effects in the modulation of melanin production, providing important insights into the development of S. flavescens as a cosmeceutical or medicinal ingredient.

Effects of Antimicrobial Flavonoids Against Representative Bacteria and Fungi: A Review of the Literature

INTRODUCTION

 Effective medications are becoming more necessary to combat the global rise in antimicrobial resistance. The findings that some flavonoids have antibacterial properties have urged interest in flavonoid research. The aim of this work was to investigate the inhibitory properties of fisetin, fisetinidin, 7,3`,4`-trihydroxyflavone (THF), and 7,3`,4`-trihydroxyflavonol (THF-) against selected pathogenic bacteria and fungi and to review the literature on relevant compounds.

METHODS

 An in vitro experiment was performed on 19 organisms (gram-positive, gram-negative, and yeast fungi) using varying concentrations (100-1000 ug/mL) of fisetin, fisetinidin, THF, and THF-. Using the agar well diffusion method. The in vitro activity of flavonoid compounds against gram-positive, gram-negative, and yeasts was assessed using a serial dilution of the four compounds against organism suspensions (50 µL of 0.5 McFarland). Inoculated agar plates were incubated aerobically at 37oC. The results of inhibition were recorded after 24, 48, and 72 hours.

RESULTS

Various classes of flavonoids from different sources have been reviewed for their antimicrobial effects. They showed various inhibitory reactions against a plethora of gram-positive, gram-negative, and yeast organisms. In the present study, the selected four compounds have shown varying antibacterial effects, as have the reviewed flavonoids from the literature. With minimum inhibitory concentrations (MICs) ranging from 100 ug/mL to 1000 ug/mL, the substances fisetin, fisetinidin, THF, and THF- demonstrated inhibitory action against the examined species. The main activity was against Staphylococcus, Bacillus, Acinetobacter, Proteus, and Pseudomonas species. Fisetin and fisetinidin did not inhibit Escherichia coli, whereas THF and THF- exhibited inhibitory action.

CONCLUSIONS

 Flavonoids, a readily accessible dietary ingredient, remain a viable treatment option for infectious diseases. This study suggests that THF, THF-, fisetin, and fisetinidin may be helpful in stopping the growth of some pathogens, especially staphylococci. Improvements to flavonoids' pharmacokinetics and diffusion may encourage their use in therapy as an adjuvant to conventional medications.

Biochanin A Inhibits the Growth and Biofilm of Candida Species

The aim of this study was to investigate the antifungal activity of biochanin A (BCA) against planktonic growth and biofilms of six Candida species, including C. albicans, C. parapsilosis, C. glabrata, C. tropicalis, C. auris, and C. krusei. We applied various assays that determined (a) the antimicrobial effect on growth of Candida species, (b) the effect on formation of hyphae and biofilm, (c) the effect on the expression of genes related to hyphal growth and biofilm formation, (d) the influence on cell wall structure, and (e) the effect on cell membrane integrity and permeability. Moreover, disk diffusion tests were used to investigate the effect of a combination of BCA with fluconazole to assess their possible synergistic effect on drug-resistant C. albicans, C. glabrata, and C. auris. Our results showed that the BCA MIC50 values against Candida species ranged between 125 µg/mL and 500 µg/mL, and the MIC90 values were in a concentration range from 250 µg/mL to 1000 µg/mL. The treatment with BCA inhibited adhesion of cells, cell surface hydrophobicity (CSH), and biofilm formation and reduced hyphal growth in all the analyzed Candida species. Real-time qRT-PCR revealed that BCA down-regulated the expression of biofilm-specific genes in C. albicans. Furthermore, physical destruction of C. albicans cell membranes and cell walls as a result of the treatment with BCA was observed. The combination of BCA and fluconazole did not exert synergistic effects against fluconazole-resistant Candida.

Local Delivery of Glabridin by Biomolecular Microneedle to Accelerate Infected Wound Healing

Applying antibacterial polymers and pro-regenerative small molecules are two individual strategies for accelerating wound healing. However, integrating those two unique approaches into one therapeutic platform that meets clinical requirements is still a challenge. Herein, a series of antibacterial gelatin methacrylate (GelMA)/ε-polylysine (ε-PL) composite hydrogels (termed as GP-n HGs, n = 0, 10, 20, and 30, respectively) are innovatively fabricated by ultraviolet light (UV) crosslinking. The GP-n HGs are proved to be broad-spectrum antibacterial and biocompatible. Among those GP-n HGs, the GP-20 HG is selectively processed into microneedle following a mold-casting method. Then, the glabridin is loaded into those needles to produce composite microneedle termed GP-20@Gla MN. An S. aureus-infected full-thickness defect model in rats is created to evaluate the wound-healing effect of GP-20@Gla MN. Furthermore, an RNA sequencing assay is performed to explore the possible molecular mechanisms of glabridin in promoting tissue regeneration, and many positive routes are summarized. This work is of significant novelty in fulfilling complex clinical needs by simultaneously optimizing the advanced microneedles' chemical compositions and physical structures. This work will provide a promising therapeutic platform for treating infected and chronic wounds.

Glabridin improves autoimmune disease in Trex1-deficient mice by reducing type I interferon production

BACKGROUND

The cGAS-STING signaling pathway is an essential section of the natural immune system. In recent years, an increasing number of studies have shown a strong link between abnormal activation of the cGAS-STING signaling pathway, a natural immune pathway mediated by the nucleic acid receptor cGAS, and the development and progression of autoimmune diseases. Therefore, it is important to identify an effective compound to specifically downregulate this pathway for disease.

METHODS

The effect of Glabridin (Glab) was investigated in BMDMs and Peripheral blood mononuclear cell (PBMC) by establishing an in vitro model of cGAS-STING signaling pathway activation. An activation model stimulated by DMXAA was also established in mice to study the effect of Glab. On the other hand, we investigated the possible mechanism of action of Glab and the effect of Glab on Trex1-deficient mice.

RESULTS

In this research, we report that Glab, a major component of licorice, specifically inhibits the cGAS-STING signaling pathway by inhibiting the level of type I interferon and inflammatory cytokines (IL-6 and TNF-α). In addition, Glab has a therapeutic effect on innate immune diseases caused by abnormal cytoplasmic DNA in Trex1-deficient mice. Mechanistically, Glab can specifically inhibit the interaction of STING with IRF3.

CONCLUSION

Glab is a specific inhibitor of the cGAS-STING signaling pathway and may be used in the clinical therapy of cGAS-STING pathway-mediated autoimmune diseases.

Tetrahedral framework nucleic acid loaded with glabridin: A transdermal delivery system applicated to anti-hyperpigmentation

Topical application of tyrosinase inhibitors, such as hydroquinone and arbutin, is the most common clinical treatment for hyperpigmentation. Glabridin (Gla) is a natural isoflavone that inhibits tyrosinase activity, free radical scavenging, and antioxidation. However, its water solubility is poor, and it cannot pass through the human skin barrier alone. Tetrahedral framework nucleic acid (tFNA), a new type of DNA biomaterial, can penetrate cells and tissues and can be used as carriers to deliver small-molecule drugs, polypeptides, and oligonucleotides. This study aimed to develop a compound drug system using tFNA as the carrier to transport Gla and deliver it through the skin to treat pigmentation. Furthermore, we aimed to explore whether tFNA-Gla can effectively alleviate the hyperpigmentation caused by increased melanin production and determine whether tFNA-Gla exerts substantial synergistic effects during treatment. Our results showed that the developed system successfully treated pigmentation by inhibiting regulatory proteins related to melanin production. Furthermore, our findings showed that the system was effective in treating epidermal and superficial dermal diseases. The tFNA-based transdermal drug delivery system can thus develop into novel, effective options for non-invasive drug delivery through the skin barrier.

360-Degree Perspectives on Obesity

Alarming statistics show that the number of people affected by excessive weight has surpassed 2 billion, representing approximately 30% of the world's population. The aim of this review is to provide a comprehensive overview of one of the most serious public health problems, considering that obesity requires an integrative approach that takes into account its complex etiology, including genetic, environmental, and lifestyle factors. Only an understanding of the connections between the many contributors to obesity and the synergy between treatment interventions can ensure satisfactory outcomes in reducing obesity. Mechanisms such as oxidative stress, chronic inflammation, and dysbiosis play a crucial role in the pathogenesis of obesity and its associated complications. Compounding factors such as the deleterious effects of stress, the novel challenge posed by the obesogenic digital (food) environment, and the stigma associated with obesity should not be overlooked. Preclinical research in animal models has been instrumental in elucidating these mechanisms, and translation into clinical practice has provided promising therapeutic options, including epigenetic approaches, pharmacotherapy, and bariatric surgery. However, more studies are necessary to discover new compounds that target key metabolic pathways, innovative ways to deliver the drugs, the optimal combinations of lifestyle interventions with allopathic treatments, and, last but not least, emerging biological markers for effective monitoring. With each passing day, the obesity crisis tightens its grip, threatening not only individual lives but also burdening healthcare systems and societies at large. It is high time we took action as we confront the urgent imperative to address this escalating global health challenge head-on.

Glabridin Ameliorates Alcohol-Caused Liver Damage by Reducing Oxidative Stress and Inflammation via p38 MAPK/Nrf2/NF-κB Pathway

Licorice is a traditional and versatile herbal medicine and food. Glabridin (Gla) is a kind of isoflavone extracted from the licorice root, which has anti-obesity, anti-atherosclerotic, and antioxidative effects. Alcoholic liver disease (ALD) is a widespread liver disease induced by chronic alcohol consumption. However, studies demonstrating the effect of Gla on ALD are rare. The research explored the positive effect of Gla in C57BL/6J mice fed by the Lieber-DeCarli ethanol mice diet and HepG2 cells treated with ethanol. Gla alleviated ethanol-induced liver injury, including reducing liver vacuolation and lipid accumulation. The serum levels of inflammatory cytokines were decreased in the Gla-treated mice. The reactive oxygen species and apoptosis levels were attenuated and antioxidant enzyme activity levels were restored in ethanol-induced mice by Gla treatment. In vitro, Gla reduced ethanol-induced cytotoxicity, nuclear factor kappa B (NF-κB) nuclear translocation, and enhanced nuclear factor (erythroid-derived 2)-like 2 (Nrf2) nuclear translocation. Anisomycin (an agonist of p38 MAPK) eliminated the positive role of Gla on ethanol-caused oxidative stress and inflammation. On the whole, Gla can alleviate alcoholic liver damage via the p38 MAPK/Nrf2/NF-κB pathway and may be used as a novel health product or drug to potentially alleviate ALD.

Glabridin Therapy Reduces Chronic Allodynia, Spinal Microgliosis, and Dendritic Spine Generation by Inhibiting Fractalkine-CX3CR1 Signaling in a Mouse Model of Tibial Fractures

Patients undergoing bone fractures frequently suffer from irritating chronic pain after orthopedic repairs. Chemokine-mediated interactions between neurons and microglia are important steps for neuroinflammation and excitatory synaptic plasticity during the spinal transmission of pathological pain. Recently, glabridin, the main bioactive component of licorice, has been shown to exhibit anti-nociceptive and neuroprotective properties for inflammatory pain. This present study evaluated the therapeutic potential of glabridin and its analgesic mechanisms using a mouse model of tibial fracture-associated chronic pain. Repetitive injections of glabridin were delivered spinally daily for 4 continuous days from days 3 to 6 after the fractures. Herein, we discovered that repeated administrations of glabridin (10 and 50 μg, but not 1 μg) could prevent prolonged cold allodynia and mechanical allodynia following bone fractures. A single intrathecal intervention with glabridin (50 μg) relieved an existing chronic allodynia two weeks following the fracture surgeries. Systemic therapies with glabridin (intraperitoneal; 50 mg kg^-1) were protective against long-lasting allodynia caused by fractures. Furthermore, glabridin restricted the fracture-caused spinal overexpressions of the chemokine fractalkine and its receptor CX3CR1, as well as the elevated number of microglial cells and dendritic spines. Strikingly, glabridin induced the inhibition of pain behaviors, microgliosis, and spine generation, which were abolished with the co-administration of exogenous fractalkine. Meanwhile, the exogenous fractalkine-evoked acute pain was compensated after microglia inhibition. Additionally, spinal neutralization of fractalkine/CX3CR1 signaling alleviated the intensity of postoperative allodynia after tibial fractures. These key findings identify that glabridin therapies confer protection against inducing and sustaining fracture-elicited chronic allodynia by suppressing fractalkine/CX3CR1-dependent spinal microgliosis and spine morphogenesis, suggesting that glabridin is a promising candidate in the translational development of chronic fracture pain control.

Research Progress on the Pharmacodynamic Mechanisms of Sini Powder against Depression from the Perspective of the Central Nervous System

Depression is a highly prevalent emotional disorder characterized by persistent low mood, diminished interest, and loss of pleasure. The pathological causes of depression are associated with neuronal atrophy, synaptic loss, and neurotransmitter activity decline in the central nervous system (CNS) resulting from injuries, such as inflammatory responses. In Traditional Chinese Medicine (TCM) theory, patients with depression often exhibit the liver qi stagnation syndrome type. Sini Powder (SNP) is a classic prescription for treating such depression-related syndrome types in China. This study systematically summarized clinical applications and experimental studies of SNP for treatments of depression. We scrutinized the active components of SNP with blood-brain barrier (BBB) permeability and speculated about the corresponding pharmacodynamic pathways relevant to depression treatment through intervening in the CNS. Therefore, this article can enhance our understanding of SNP's pharmacological mechanisms and formula construction for depression treatment. Moreover, a re-demonstration of this classic TCM prescription in the modern-science language is of great significance for future drug development and research.