Glycyrrhizic acid inhibits DNA damage repair and enhances cisplatin-induced apoptosis of melanoma cells.

This research was designed to prospect the mechanism and impact of glycyrrhizic acid (GA) on DNA damage repair and cisplatin (CP)-induced apoptosis of melanoma cells. First, human melanoma cell SK-MEL-28 was stimulated using GA for 24, 48, and 72 h. Then, the optimal treatment time and dosage were selected. After that, cell counting kit-8 (CCK-8) was employed for testing the cell viability, flow cytometry for the apoptosis, comet assay for the DNA damage of cells, and western blot for the cleaved-Caspase3, Caspase3, Bcl-2, and γH2AX protein expression levels. The experimental outcomes exhibited that as the GA concentration climbed up, the SK-MEL-28 cell viability dropped largely, while the apoptosis level raised significantly, especially at the concentration of 100 µm. In addition, compared with GA or CPtreatment only, CP combined with GA notably suppressed the viability of melanoma cells and promoted cell apoptosis at the cytological level. At the protein level, the combined treatment notably downregulated the Bcl-2 and Caspase3 expression levels, while significantly upregulated the cleaved-Caspase3 and γH2AX expression levels. Besides, CP + GA treatment promoted DNA damage at the DNA molecular level. Collectively, both GA and CP can inhibit DNA damage repair and enhance the apoptosis of SK-MEL-28 cells, and the synergistic treatment of both exhibits better efficacy.

Green Synthesis of Blumea balsamifera Oil Nanoemulsions Stabilized by Natural Emulsifiers and Its Effect on Wound Healing.

In this study, we developed a green and multifunctional bioactive nanoemulsion (BBG-NEs) of Blumea balsamifera oil using Bletilla striata polysaccharide (BSP) and glycyrrhizic acid (GA) as natural emulsifiers. The process parameters were optimized using particle size, PDI, and zeta potential as evaluation parameters. The physicochemical properties, stability, transdermal properties, and bioactivities of the BBG-NEs under optimal operating conditions were investigated. Finally, network pharmacology and molecular docking were used to elucidate the potential molecular mechanism underlying its wound-healing properties. After parameter optimization, BBG-NEs exhibited excellent stability and demonstrated favorable in vitro transdermal properties. Furthermore, it displayed enhanced antioxidant and wound-healing effects. SD rats wound-healing experiments demonstrated improved scab formation and accelerated healing in the BBG-NE treatment relative to BBO and emulsifier groups. Pharmacological network analyses showed that AKT1, CXCL8, and EGFR may be key targets of BBG-NEs in wound repair. The results of a scratch assay and Western blotting assay also demonstrated that BBG-NEs could effectively promote cell migration and inhibit inflammatory responses. These results indicate the potential of the developed BBG-NEs for antioxidant and skin wound applications, expanding the utility of natural emulsifiers. Meanwhile, this study provided a preliminary explanation of the potential mechanism of BBG-NEs to promote wound healing through network pharmacology and molecular docking, which provided a basis for the mechanistic study of green multifunctional nanoemulsions.

Glycyrrhizin attenuates renal inflammation in a mouse Con A-hepatitis model via the IL-25/M2 axis.

Glycyrrhizin (GL) has immunoregulatory effects on various inflammatory diseases including hepatitis and nephritis. However, the mechanisms underlying the anti-inflammatory effect of GL on renal inflammation are not fully understood. Hepatorenal syndrome (HRS) is a functional acute renal impairment that occurs in severe liver disease, and we found that kidney injury also occurs in Con A-induced experimental hepatitis in mice. We previously found that GL can alleviate Con A-induced hepatitis by regulating the expression of IL-25 in the liver. We wanted to investigate whether GL can alleviate Con A-induced nephritis by regulating IL-25. IL-25 regulates inflammation by modulating type 2 immune responses, but the mechanism by which IL-25 affects kidney disease remains unclear. In this study, we found that the administration of GL enhanced the expression of IL-25 in renal tissues; the latter promoted the generation of type 2 macrophages (M2), which inhibited inflammation in the kidney caused by Con A challenge. IL-25 promoted the secretion of the inhibitory cytokine IL-10 by macrophages but inhibited the expression of the inflammatory cytokine IL-1ß by macrophages. Moreover, IL-25 downregulated the Con A-mediated expression of Toll-like receptor (TLR) 4 on macrophages. By comparing the roles of TLR2 and TLR4, we found that TLR4 is required for the immunoregulatory effect of IL-25 on macrophages. Our data revealed that GL has anti-inflammatory effects on Con A-induced kidney injury and that the GL/IL-25/M2 axis participates in the anti-inflammatory process. This study suggested that GL is a potential therapeutic for protecting against acute kidney injury.

Glycyrrhizic Acid Alleviates Semen Strychni-Induced Neurotoxicity Through the Inhibition of HMGB1 Phosphorylation and Inflammatory Responses.

The neurotoxicity of Semen Strychni has been reported recently in several clinical cases. Therefore, this study was conducted to investigate the role of HMGB1 in a model of neurotoxicity induced by Semen Strychni and to assess the potential alleviating effects of glycyrrhizic acid (GA), which is associated with the regulation of HMGB1 release. Forty-eight SD rats were intraperitoneally injected with Semen Strychni extract (175 mg/kg), followed by oral administration of GA (50 mg/kg) for four days. After treatment of SS and GA, neuronal degeneration, apoptosis, and necrosis were observed via histopathological examination. Inflammatory cytokines (TNF-α and IL-1ß), neurotransmitter associated enzymes (MAO and AChE), serum HMGB1, nuclear and cytoplasmic HMGB1/ph-HMGB1, and the interaction between PP2A, PKC, and HMGB1 were evaluated. The influence of the MAPK pathway was also examined. As a result, this neurotoxicity was characterized by neuronal degeneration and apoptosis, the induction of pro-inflammatory cytokines, and a reduction in neurotransmitter-metabolizing enzymes. In contrast, GA treatment significantly ameliorated the abovementioned effects and alleviated nerve injury. Furthermore, Semen Strychni promoted HMGB1 phosphorylation and its translocation between the nucleus and cytoplasm, thereby activating the NF-κB and MAPK pathways, initiating various inflammatory responses. Our experiments demonstrated that GA could partially reverse these effects. In summary, GA acid alleviated Semen Strychni-induced neurotoxicity, possibly by inhibiting HMGB1 phosphorylation and preventing its release from the cell.

The Effect of Glycyrrhizin on the Viability and Proliferation of Dental Pulp Stem Cells Compared to Intracanal Medicaments.

AIM: To study the effect of glycyrrhizin (GA) on the viability and proliferation of dental pulp stem cells (DPSCs) compared with intracanal medicaments. MATERIALS AND METHODS: Third molars of an adult donor were used to obtain the DPSCs. Flow cytometry was utilized to conduct phenotypic analysis for DPSCs. The methyl-thiazol tetrazolium (MTT) test was used to detect the cell viability. Cell proliferation assay was conducted at distinct time intervals: 3, 5, and 7 days. RESULTS: The flow cytometry analysis verified the positive expression of mesenchymal cell surface antigen molecules (CD73, CD90, and CD105) and the absence of hematological markers (CD14, CD34, and CD45) in the DPSCs. The cells that treated with concentrations more than 0.5 mg/mL of Ca(OH2) and triple antibiotic paste (TAP) gave significant decrease in viability in comparison to the untreated cells (p < 0.05). Also, the cells treated with concentrations 50 and 25 µM of GA showed no significant difference compared with the untreated cells (p > 0.05), while concentrations 12.5 and 6.25 µM expressed a significant increase in viability compared with the untreated cells (p < 0.05). At 7 days, cells treated with the three different concentrations of GA (12.5, 25, and 50 µM) demonstrated a significant increase in cell density compared with Ca(OH)2 and TAP-treated cells (p < 0.05). CONCLUSION: Based upon the potential of GA on DPSCs proliferation compared with Ca(OH)2 and TAP, It is conceivable to acknowledge that GA could be used as an intracanal medicaments for revascularization process of necrotic immature teeth. CLINICAL SIGNIFICANCE: This study emphasizes the significance of assessing alternative root canal medicaments and their impact on the proliferation and viability of DPSCs. The results regarding GA, specifically its impact on the viability and growth of DPSCs, provide essential understanding for its potential application as an intracanal medicine. This study adds to the continuous endeavors in identifying safer and more efficient intracanal therapies, which are essential for improving patient outcomes in endodontic operations. How to cite this article: Alrashidi MA, Badawi MF, Elbeltagy MG, et al. The Effect of Glycyrrhizin on the Viability and Proliferation of Dental Pulp Stem Cells Compared to Intracanal Medicaments. J Contemp Dent Pract 2024;25(3):267-275.

Alloy nanozyme-reinforced hyaluronic acid-based hydrogel with wound environment-responsive properties for synergistically accelerating infectious wound healing.

The recovery of infectious wound tissues presents a significant global health challenge due to the impediments posed by the harsh healing microenvironment, which includes ongoing bacterial invasion, high oxidative stress, inflammatory response, and impaired angiogenesis. To overcome the above issues, we propose a composite hydrogel based on the multiple-crosslinked mechanism involving the covalent network of CC bonds within catechol and maleic-modified HA (CMHA), the self-assembly network of glycyrrhizic acid (GA), and the metal-polyphenol coordination induced by ZHMCe for accelerating infectious wound healing. The resulting CMHA/GA/ZHMCe hydrogels demonstrate enhanced mechanical, adhesive, antioxidative, and antibacterial properties. Importantly, the hydrogel system possesses wound environment-responsive properties that allow it to adapt to the specific therapeutic requirements of different stages by regulating various enzyme activities in the healing of infected wounds. Furthermore, the biocompatible CMHA/GA/ZHMCe shows the ability to promote cell migration and angiogenesis in vitro while reprogramming macrophages toward an anti-inflammatory phenotype due to the effective release of active ingredients. In vivo experiments confirm that the CMHA/GA/ZHMCe hydrogel significantly enhances infectious wound healing by accelerating re-epithelialization, promoting collagen deposition, regulating inflammation, and contributing to vascularization. These findings underscore the therapeutic potential of our hydrogel dressings for the treatment of bacterially infected cutaneous wound healing.

Combinational strategy using albumin-based nanoparticles to enable synergetic anti-rheumatic efficacy and reduced hepatotoxicity.

Methotrexate (MTX) is recognized as the golden standard for rheumatoid arthritis (RA) treatment. However, it can cause liver damage in long-term application. Although nanomedicines can target to inflamed sites, most of them tend to accumulate in liver. Glycyrrhizinic acid (GA) holds potential to reverse MTX-associated hepatotoxicity. The combination of GA and MTX might achieve a synergistic anti-inflammatory efficacy and reduced hepatotoxicity. As MTX and GA have totally different in vivo performance, it is necessary to co-encapsulate them in one carrier to coordinate their in vivo fates. Here, we co-delivered MTX and GA to arthritic joints using a human serum albumin-based nanoparticle (HSN). We found the dual drug-loaded albumin nanoparticles (HSN/MTX/GA) could preferentially distribute in inflamed joints, where GA can extend MTX retention by inhibiting the expression of efflux pumps for MTX, thereby exerting synergistic therapeutic effect. In liver tissues, GA was able to reverse the MTX-induced liver damage by activating anti-oxidant defense Nrf2/HO-1 and anti-apoptosis Bcl-2/Bax signaling. We offer a combinational strategy to effectively overcome the MTX-induced hepatotoxicity and enhance the anti-rheumatic efficacy simultaneously. Furthermore, we verified the underlying mechanism about how GA cooperated with MTX in vivo for the first time. Our findings can provide valuable insights for long-term treatment of RA.

HMGB1 promotes neutrophil PD-L1 expression through TLR2 and mediates T cell apoptosis leading to immunosuppression in sepsis.

Neutrophils and T lymphocytes are closely related to occurrence of immunosuppression in sepsis. Studies have shown that neutrophil apoptosis decreases and T lymphocyte apoptosis increases in sepsis immunosuppression, but the specific mechanism involved remains unclear. In the present study, we found Toll-like Receptor 2 (TLR2) and programmed death-ligand 1 (PD-L1) were significantly activated in bone marrow neutrophils of wild-type mice after LPS treatment and that they were attenuated by treatment with C29, an inhibitor of TLR2. PD-L1 activation inhibits neutrophil apoptosis, whereas programmed death protein 1 (PD-1)activation promotes apoptosis of T lymphocytes, which leads to immunosuppression. Mechanistically, when sepsis occurs, pro-inflammatory factors and High mobility group box-1 protein (HMGB1) passively released from dead cells cause the up-regulation of PD-L1 through TLR2 on neutrophils. The binding of PD-L1 and PD-1 on T lymphocytes leads to increased apoptosis of T lymphocytes and immune dysfunction, eventually resulting in the occurrence of sepsis immunosuppression. In vivo experiments showed that the HMGB1 inhibitor glycyrrhizic acid (GA) and the TLR2 inhibitor C29 could inhibit the HMGB1/TLR2/PD-L1 pathway, and improving sepsis-induced lung injury. In summary, this study shows that HMGB1 regulates PD-L1 and PD-1 signaling pathways through TLR2, which leads to immunosuppression.

The mechanistic interaction, aggregation and neurotoxicity of α-synuclein after interaction with glycyrrhizic acid: Modulation of synucleinopathies.

This article reveals the binding mechanism between glycyrrhizic acid (GA) and α-synuclein to may provide further information for the modulation of synucleinopathies using bioactive compounds. Therefore, the inhibitory activities of GA against α-synuclein aggregation and induced neurotoxicity were evaluated using different assays. Results showed that α-synuclein-GA binding was mediated by intermolecular hydrogen bonds leading to the formation of a slightly folded complex. Theoretical studies revealed that GA binds to the N-terminal domain of α-synuclein and triggers a compact structure around a major part of the N-terminal and the NAC regions along with fluctuations in the C-terminal domain, which are prerequisites for the inhibition of α-synuclein aggregation. Then, the cellular assays showed that GA as a potential small molecule can inhibit the oligomerization of α-synuclein and relevant neurotoxicity through modulation of neural viability, membrane leakage, and ROS formation in a concentration-dependent manner. As a result, the primary mechanism of GA's anti-aggregation and neuroprotective activities is the reorganized α-synuclein structure and fluctuating C-terminal domain, which promotes long-range transient intramolecular contacts between the N-terminal and the C-terminal domain.

In vitro and in silico investigation of glycyrrhizic acid encapsulated zein nanoparticles: A synergistic targeted drug delivery approach for breast cancer.

This study presents an innovative approach for targeted drug delivery through the development of Glycyrrhizic acid-loaded zein nanoparticles (GA-LNPs) as a proficient carrier system. The juxtaposition of zein, a hydrophobic biological macromolecule as a protein carrier, and Glycyrrhizic acid (GA), a hydrophilic therapeutic compound, exemplifies the adaptability of hydrocolloids within cutting-edge drug delivery systems. The characterization and functional traits of research encompass multifaceted analyses of natural macromolecules, which elucidate the homogeneous and spherical morphology of GA-LNPs with an average size of 170.49 nm. The controlled drug release profile of GA, orchestrated under simulated gastrointestinal conditions, adheres to diffusion-based Higuchi kinetics, reflecting the controlled release of the natural macromolecules. The intermolecular interactions among Zein, GA, and cross-linker EDC, facilitated through molecular dynamics simulations, fortify the structural integrity of the encapsulation matrix. In Vitro studies revealed enhanced cellular uptake of GA-LNPs in MCF-7 breast cancer cells. This cellular internalization was further confirmed through cytotoxicity assessments using MTT and apoptosis assays (fluorescence microscopy), which demonstrated the prominent anticancer effects of GA-LNPs on MCF-7 in time/dose-dependent manner. The successful formulation of GA-LNPs, coupled with their sustained release and potent anticancer properties, makes them a potential platform for advanced targeted therapeutic strategies in biomedical applications.

Glycyrrhizic acid attenuates sorafenib resistance by inducing ferroptosis via targeting mTOR signaling in hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is the most malignant cancer worldwide. Sorafenib (SRF) is a common therapeutic drug used for patients with advanced HCC. Nevertheless, drug resistance frequently occurs in patients treated with sorafenib. Glycyrrhizic acid (GRA) is a natural compound that is identified to exhibit anti-cancer effects. In this work, we aimed to investigate the effects of GRA on SRF-resistant HCC cells and the potential regulatory mechanisms. METHODS: We established SRF-resistant HCC cell lines and administrated GRA treatment. We performed CCK-8 and colony formation experiments to detect cell proliferation. The accumulation of lipid reactive oxygen species (ROS) and iron levels were measured to evaluate ferroptosis. The protein levels of ferroptosis suppressor glutathione peroxidase 4 (GPX4) and SLC7A11, and the activation of AKT and mTOR were measured with western blotting assay. RESULTS: GRA treatment notably suppressed the viability and proliferation of SRF-resistant HCC cells. SRF-resistant HCC cells exhibited repressed ferroptosis level activated AKT/mTOR cascade, and GRA treatment reversed these effects. Inhibition of ferroptosis and activation of mTOR reversed the anti-proliferation effects of GRA on SRF-resistant HCC cells. CONCLUSION: Treatment with GRA could effectively reverse the SRF resistance of HCC cells via inducing ferroptosis and inactivating the AKT/mTOR cascade.

DIAMMONIUM GLYCYRRHIZINATE INHIBITED INFLAMMATORY RESPONSE AND MODULATED SERUM METABOLISM IN POLY(I:C)-INDUCED PNEUMONIA MODEL MICE.

ABSTRACT: Currently, the coronavirus disease 2019 (COVID-19) is becoming a serious threat to human health worldwide. Therefore, there is a great need to develop effective drugs against viral pneumonia. Diammonium glycyrrhizinate (DG), derived from Glycyrrhiza glabra L., has been demonstrated with significant anti-inflammatory properties. However, the therapeutic effects and mechanisms of DG on pneumonia require further clarification. In this study, mice received intratracheal injection of polyinosinic-polycytidylic acid (poly(I:C)) to induce pneumonia and were treated with DG. First, we evaluated the therapeutic potential of DG on poly(I:C)-induced pneumonia. Second, the anti-inflammatory and antioxidative activities and the impact of DG on the toll-like receptor 3 (TLR3) pathway were investigated. Third, the mechanism of DG was analyzed through untargeted metabolomics techniques. Our results revealed that DG intervention decreased permeability and reduced abnormal lung alterations in poly(I:C)-induced pneumonia model mice. DG intervention also downregulated cytokine levels in bronchoalveolar lavage fluid. Moreover, DG treatment inhibited the activation of TLR3 pathway. Furthermore, untargeted metabolomics analysis revealed that DG intervention could modulate serum metabolites involved in amino and nucleotide sugar metabolism, fructose and mannose metabolism, tyrosine metabolism, and phenylalanine, tyrosine, and tryptophan biosynthesis pathways. In conclusion, our study showed that DG could ameliorate poly(I:C)-induced pneumonia by inactivating the TLR3 pathway and affecting amino and nucleotide sugar, fructose and mannose metabolism, as well as tryptophan, phenylalanine, and tyrosine biosynthesis.

Development of Glycyrrhizinic Acid-Based Lipid Nanoparticle (LNP-GA) as An Adjuvant That Improves the Immune Response to Porcine Epidemic Diarrhea Virus Spike Recombinant Protein.

Porcine epidemic diarrhea virus (PEDV) has affected the pork industry worldwide and during outbreaks the mortality of piglets has reached 100%. Lipid nanocarriers are commonly used in the development of immunostimulatory particles due to their biocompatibility and slow-release delivery properties. In this study, we developed a lipid nanoparticle (LNP) complex based on glycyrrhizinic acid (GA) and tested its efficacy as an adjuvant in mice immunized with the recombinant N-terminal domain (NTD) of porcine epidemic diarrhea virus (PEDV) spike (S) protein (rNTD-S). The dispersion stability analysis (Z-potential -27.6 mV) confirmed the size and charge stability of the LNP-GA, demonstrating that the particles were homogeneously dispersed and strongly anionic, which favors nanoparticles binding with the rNTD-S protein, which showed a slightly positive charge (2.11 mV) by in silico analysis. TEM image of LNP-GA revealed nanostructures with a spherical-bilayer lipid vesicle (~100 nm). The immunogenicity of the LNP-GA-rNTD-S complex induced an efficient humoral response 14 days after the first immunization (p < 0.05) as well as an influence on the cellular immune response by decreasing serum TNF-α and IL-1ß concentrations, which was associated with an anti-inflammatory effect.

Glycyrrhizin and the Related Preparations: An Inspiring Resource for the Treatment of Liver Diseases.

Liver diseases and their related complications endanger the health of millions of people worldwide. The prevention and treatment of liver diseases are still serious challenges both in China and globally. With the improvement of living standards, the prevalence of metabolic liver diseases, including non-alcoholic fatty liver disease and alcoholic liver disease, has increased at an alarming rate, resulting in more cases of end-stage liver disease. Therefore, the discovery of novel therapeutic drugs for the treatment of liver diseases is urgently needed. Glycyrrhizin (GL), a triterpene glycoside from the roots of licorice plants, possesses a wide range of pharmacological and biological activities. Currently, GL preparations (GLPs) have certain advantages in the treatment of liver diseases, with good clinical effects and fewer adverse reactions, and have shown broad application prospects through multitargeting therapeutic mechanisms, including antisteatotic, anti-oxidative stress, anti-inflammatory, immunoregulatory, antifibrotic, anticancer, and drug interaction activities. This review summarizes the currently known biological activities of GLPs and their medical applications in the treatment of liver diseases, and highlights the potential of these preparations as promising therapeutic options and their alluring prospects for the treatment of liver diseases.

Glycyrrhizic acid treatment ameliorates anxiety-like behaviour via GLT1 and Per1/2-dependent pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: As a traditional Chinese medicinal herb, Glycyrrhiza. URALENSIS: Fisch. (licorice root, chinese name: Gancao) has a variety of medicinal values and is widely used clinically. Its main active ingredient, glycyrrhizic acid (GA), is believed to have a neuroprotective effect. However, the underlying biological mechanisms of GA on stress-induced anxiety disorders are still unclear. AIM OF THE STUDY: To investigate the anti-anxiety effect of GA and its underlying mechanism. METHODS: We selected the anxiety model induced by repeated chronic restraint stress (CRS) for 2 h on each of 7 consecutive days. GA (4, 20, 100 mg/kg) was injected intraperitoneally once daily for 1 week. The potential GA receptors were identified using whole-cell patches and computer-assisted docking of molecules. High-throughput RNA sequencing, adeno-associated virus-mediated gene regulation, Western blotting, and RT-qPCR were used to assess the underlying molecular pathways. RESULTS: GA alleviate depression-like and anxiety-like behaviors in CRS mice. GA decreased synaptic transmission by facilitating glutamate reuptaking in mPFC. Meanwhile, long-term GA treatment increased the expression of clock genes Per1 and Per2. Suppressing both Per1 and Per2 abolished the anxiolytic effects of GA treatment. CONCLUSION: Our study suggests that GA may be developed for the treatment of stress-induced anxiety disorders, and its mechanism is related to GLT1 and Per1/2-dependent pathways. This presents a novel approach to discovering potent therapeutic drugs.

NMR Study of Water-Soluble Carotenoid Crocin: Formation of Mixed Micelles, Interaction with Lipid Membrane and Antioxidant Activity.

Crocin is a unique water-soluble carotenoid found in crocus and gardenia flowers. Crocin has been shown to have a variety of pharmacological activities, such as antioxidant, anti-cancer, memory improvement, antidepressant, anti-ischemia, blood pressure lowering and aphrodisiac, gene protection and detoxification activities. Due to their amphiphilicity, crocin molecules form concentration-dependent self-associates (micelles) in a water solution. In the present study, using various NMR techniques (T2 relaxation and selective gradient NOESY), we have demonstrated that crocin forms mixed micelles with water-soluble drug delivery system glycyrrhizin and linoleic acid molecules. Note, that the spin-spin T2 relaxation time and NOESY spectroscopy are very sensitive to intermolecular interactions and molecular diffusion mobility. The second purpose of this work was the elucidation of the interaction of crocin with a model lipid membrane using NMR techniques and a molecular dynamics simulation and its effects on lipid oxidation. It was shown that the crocin molecule is located near the surface of the lipid bilayer and effectively protects lipids from oxidation by peroxyl radicals. The role of glycyrrhizin and vitamin C in metal-induced lipid oxidation was also elucidated. The results of this study may be useful for expanding the field of application of crocin in medicine and in the food industry.

Glycyrrhizic acid restores the downregulated hepatic ACE2 signaling in the attenuation of mouse steatohepatitis.

Glycyrrhizic acid (GA), one of the major active components derived from licorice root, exerts liver-protecting activity. Its molecular mechanisms of action, however, remain not completely understood. The angiotensin (Ang) converting enzyme (ACE) 2/Ang-(1-7)/Mas axis, regulated by ACE2 through converting Ang II into Ang-(1-7) to activate Mas receptor, counteracts the pro-inflammatory and pro-steatotic effects of the ACE/Ang II/Ang II receptor type 1 (AT1) axis. Here, it was found that pretreatment with GA suppressed LPS/D-galactosamine-induced serum hyperactivities of alanine aminotransferase and aspartate aminotransferase, hepatomegaly, pathological changes, and over-accumulation of triglycerides and fatty droplets in the liver of mice. GA also diminished LPS/free fatty acid-induced inflammation and steatosis in cultured hepatocytes. Mechanistically, GA restored hepatic protein hypoexpression of ACE2 and Mas receptor, and the decrease in hepatic Ang-(1-7) content. Hepatic overexpression of angiotensin II and AT1 was also suppressed. However, GA did not alter hepatic protein expression of renin and ACE. In addition, GA inhibited hepatic protein over-phosphorylation of the p38 mitogen-activated protein kinase, c-Jun N-terminal kinase, extracellular signal-regulated kinase, and nuclear factor κB at Ser536. Hepatic overexpression of tumor necrosis factor α, interleukin 6, interleukin 1ß, sterol regulatory element-binding protein 1c, and fatty acid synthase was also inhibited. GA-elicited recovery of ACE2 and Mas protein hypoexpression was further confirmed in the hepatocyte. Thus, the present results demonstrate that GA restores the downregulated hepatic ACE2-mediated anti-inflammatory and anti-steatotic signaling in the amelioration of steatohepatitis. We suggest that GA may protect the liver from injury by regulating the hepatic ACE2-mediated signaling.

Biosynthesis of Chryseno[2,1,c]oxepin-12-Carboxylic Acid from Glycyrrhizic Acid in Aspergillus terreus TMZ05-2, and Analysis of Its Anti-inflammatory Activity.

Glycyrrhizic acid, glycyrrhetinic acid, and their oxo, ester, lactone, and other derivatives, are known for their anti-inflammatory, anti-oxidant, and hypoglycemic pharmacological activities. In this study, chryseno[2,1-c]oxepin-12-carboxylic acid (MG) was first biosynthesized from glycyrrhizic acid through sequential hydrolysis, oxidation, and esterification using Aspergillus terreus TMZ05-2, providing a novel in vitro biosynthetic pathway for glycyrrhizic acid derivatives. Assessing the influence of fermentation conditions and variation of strains during culture under stress-induction strategies enhanced the final molar yield to 88.3% (5 g/L glycyrrhizic acid). CCK8 assays showed no cytotoxicity and good cell proliferation, and anti-inflammatory experiments demonstrated strong inhibition of NO release (36.3%, low-dose MG vs. model), transcriptional downregulation of classical effective cellular factors tumor necrosis factor-α (TNF-α; 72.2%, low-dose MG vs. model), interleukin-6 (IL-6; 58.3%, low-dose MG vs. model) and interleukin-1ß (IL-1ß; 76.4%, low-dose MG vs. model), and decreased abundance of P-IKK-α, P-IKB-α, and P-P65 proteins, thereby alleviating inflammatory responses through the NF-κB pathway in LPS-induced RAW264.7 cells. The findings provide a reference for the biosynthesis of lactone compounds from medicinal plants.

A low dose of daily licorice intake affects renin, aldosterone, and home blood pressure in a randomized crossover trial.

BACKGROUND: Licorice, through the effects of glycyrrhizic acid (GA), raises blood pressure (BP). The World Health Organization has suggested that 100 mg GA/d would be unlikely to cause adverse effects, but of 13 previously published studies none have been randomized and controlled and independently quantified the GA content. OBJECTIVE: Our aim was to analyze the effects on home BP of a daily licorice intake containing 100 mg GA. METHODS: Healthy volunteers were randomly assigned to start with either licorice or a control product in a nonblinded, 2 × 2 crossover study. Home BP was measured daily, and blood samples were collected at the end of each 2-wk period. RESULTS: There were 28 participants and no dropouts. The median age was 24.0 y (interquartile range 22.8-27.0 y). During the licorice compared with control intake period, the systolic home BP increased [mean difference: 3.1 mm Hg (95% confidence interval [CI]: 0.8, 5.4 mm Hg) compared with -0.3 mm Hg (95% CI: -1.8, 1.3 mm Hg); P = 0.018] and renin and aldosterone were suppressed [mean change: -30.0% (95% CI: -56.7%, -3.3%) compared with 15.8% (95% CI: -12.8%, 44.4%); P = 0.003; and -45.1% (95% CI: -61.5%, -28.7%) compared with 8.2% (95% CI: -14.7%, 31.1%); P <0.001, respectively]. In the quartile of participants with the most pronounced suppression of renin and aldosterone, N-terminal prohormone of brain natriuretic peptide concentration increased during the licorice compared with control period [mean change: 204.1% (95% CI: -11.6%, 419.7%) compared with 72.4% (95% CI: -52.2%, 197.1%); P = 0.016]. CONCLUSIONS: We found licorice to be more potent than previously known, with significant increases in BP, after a daily intake of only 100 mg GA. Thus, the safe limit of intake of this substance might need to be reconsidered. This trial was registered at clinicaltrials.gov as NCT05661721 (https://clinicaltrials.gov/study/NCT05661721).

Development and Evaluation of a Novel Hyaluronic Acid and Chitosan-modified Phytosome for Co-delivery of Oxymatrine and Glycyrrhizin for Combination Therapy.

BACKGROUND: Multidrug resistance (MDR) of cancer cells is a major obstacle to efficient cancer chemotherapy. Combination therapy is expected to enhance the anticancer effect and reverse MDR. Numerous patents involve different kinds of nanoparticles for the co-delivery of multiple chemotherapeutics, but the FDA has approved none. OBJECTIVE: In this study, oxymatrine (OMT) and glycyrrhizin (GL) were co-loaded into phytosomes as the core of nanocarriers, and the shell was cross-linked with chitosan (CS) and hyaluronic acid (HA) with the capability for the controlled, sequential release and the targeted drug uptake. METHODS: Phospholipid complexes of OMT and GL (OGPs) were prepared by a solvent evaporation technique and could self-assemble in an aqueous solution to form phytosomes. CS and HA were sequentially coated on the surface of OGPs via electrostatic interactions to obtain CS coated OGPs (CS-OGPs) and HA modified CS-OGPs (HA-CS-OGPs), respectively. The particle size and zeta potential were measured to optimize the formulations. In vitro cytotoxicity and cellular uptake experiments on HepG2 cells were performed to evaluate the anticancer activity. RESULTS: OGPs were obtained with nano-size around 100 nm, and CS and HA coating on phytosomes could change the particle size and surface potential. The drug loading of OMT and GL showed that the nanocarriers could maintain a fixed ratio of 1:1. The in vitro release experiments indicated the release of OMT and GL was pH-dependent and sequential: the release of OMT from CS-OGPs and HA-CS-OGPs was significantly increased at pH 5.0 compared to the release at pH 7.4, while GL exhibited sustained released from CS-OGPs and HA-CS-OGPs at pH 5.0. Furthermore, in vitro cytotoxicity and cellular uptake experiments on HepG2 cells demonstrated that the co-delivery system based on phytosomes had significant synergistic anti-tumor activities, and the effects were enhanced by CS and HA modification. CONCLUSION: The delivery of OMT and GL via HA-CS-OGPs might be a promising treatment to reverse MDR in cancer therapy.