[3-O-ß-chacotriosyl glycyrrhetinic acid derivatives as potential small-molecule SARS-CoV-2 fusion inhibitors against SARS-CoV-2 entry into host cells].

OBJECTIVE: To study the inhibitory activities of 3-O-ß-chacotriosyl glycyrrhetinic acid derivatives against the entry of SARS-CoV-2 into host cells. METHODS: With pentacyclic triterpene saponin glycyrrhizic acid (a natural SARS-CoV-2 entry inhibitor) as the lead compound, a series of 3-O-ß-chacotriosyl glycyrrhetinic acid derivatives were designed and synthesized based on hypridization principle, and their inhibitory activities against virus entry were tested in SARS-CoV-2 pseudovirusinfected cells. The antiviral targets of the lead compound 1b was identified by pseudotyped SARS-CoV-2 infection assay and surface plasmon resonance (SPR) assay, and the S protein-mediated cell-cell fusion assay was used to evaluate the effect of 1b on virus-cell membrane fusion. Molecular docking and single amino acid mutagenesis were carried out to analyze the effect of 1b on binding activitiy of S protein. RESULTS: The lead compound 1b showed significant inhibitory effect against Omicron pseudovirus with an EC50 value of 3.28 µmol/L (P < 0.05), and had broad-spectrum antiviral activity against other SARS-CoV-2 pseudovirus. Spike-dependent cell-cell fusion assay demonstrated an inhibitory effect of 1b against SARS-CoV-2 S proteinmediated cell-cell fusion. Molecular docking analysis predicted that the lead compound 1b could be well fitted into a cavity between the attachment (S1) and fusion (S2) subunits at the 3-fold axis, where it formed multiple hydrophobic interactions with Glu309, Ser305, Arg765 and Lys964 residues with a KD value of -8.6 kcal/mol. The compound 1b at 10, 5, 2.5 and 1.25 µmol/L showed a significantly reduced inhibitory activity against the pseudovirus with mutated Arg765, Lys964, Glu309 and Leu303 (P < 0.01). CONCLUSION: 3-O-ß-chacotriosyl glycyrrhetinic acid derivatives are capable of stabilizing spike protein in the pre-fusion step to interfere with the fusion of SARS-CoV-2 with host cell membrane, and can thus serve as potential novel small-molecule SARS-CoV-2 fusion inhibitors.

Identification of 18ß-glycyrrhetinic acid as an AGT inhibitor against LPS-induced myocardial dysfunction via high throughput screening.

Sepsis induced myocardial dysfunction (SIMD) is a serious complication of sepsis. There is increasing evidence that the renin-angiotensin system (RAS) is activated in SIMD. Angiotensinogen (AGT) is a precursor of the RAS, and the inhibition of AGT may have significant cardiovascular benefits. But until now, there have been no reports of small molecule drugs targeting AGT. In this study, we designed a promoter-luciferase based system to screen for novel AGT inhibitors to alleviate SIMD. As a result of high-throughput screening, a total of 5 compounds from 351 medicinal herb-derived natural compounds were found inhibiting AGT. 18ß-glycyrrhetinic acid (18ßGA) was further identified as a potent suppressor of AGT. In vitro experiments, 18ßGA could inhibit the secretion of AGT by HepG2 cells and alleviate the elevated level of mitochondrial oxidative stress in cardiomyocytes co-cultured with HepG2 supernatants. In vivo, 18ßGA prolonged the survival rate of SIMD mice, enhanced cardiac function, and inhibited the damage of mitochondrial function and inflammation. In addition, the results showed that 18ßGA may reduce AGT transcription by downregulating hepatocyte nuclear factor 4 (HNF4) and that further alleviated SIMD. In conclusion, we provided a more efficient screening strategy for AGT inhibitors and expanded the novel role of 18ßGA as a promising lead compound in rescuing cardiovascular disease associated with RAS overactivation.

Glycyrrhetinic acid inhibits non-small cell lung cancer via promotion of Prdx6- and caspase-3-mediated mitochondrial apoptosis.

Glycyrrhetinic acid (GA) shows great efficiency against non-small cell lung cancer (NSCLC), but the detailed mechanism is unclear, which has limited its clinical application. Herein, we investigated the potential targets of GA against NSCLC by activity-based protein profiling (ABPP) technology and the combination of histopathology and proteomics validation. In vitro and in vivo results indicated GA significantly inhibited NSCLC via promotion of peroxiredoxin-6 (Prdx6) and caspase-3 (Casp3)-mediated mitochondrial apoptosis. This original finding will provide theoretical and data support to improve the treatment of NSCLC with the application of GA.

18ß-Glycyrrhetinic acid exerts cardioprotective effects against BPA-induced cardiotoxicity through antiapoptotic and antioxidant mechanisms.

Bisphenol A (BPA) is a synthetic environmental pollutant widely used in industry, as well as is an endocrine disrupting chemicals and has a toxic effects on heart tissue. The aim of this study is to reveal the cardioprotective effects of 18ß-glycyrretinic acid (GA) against BPA-induced cardiotoxicity in rats. In this study, 40 male rats were used and five different groups (each group includes eight rats) were formed. The rats were applied BPA (250 mg/kg b.w.) alone or with GA (50 and 100 mg/kg b.w.) for 14 days. Rats were killed on Day 15 and heart tissues were taken for analysis. GA treatment decreased serum lactate dehydrogenase and creatine kinase MB levels, reducing BPA-induced heart damage. GA treatment showed ameliorative effects against lipid peroxidation and oxidative stress caused by BPA by increasing the antioxidant enzyme activities (glutathione peroxidase, superoxide dismutase, and catalase) and GSH level of the heart tissue and decreasing the MDA level. In addition, GA showed antiapoptotic effect by increasing Bcl-2, procaspase-3, and -9 protein expression levels and decreasing Bax, cytochrome c, and P53 protein levels in heart tissue. As a result, it was found that GA has cardioprotective effects on heart tissue by exhibiting antioxidant and antiapoptotic effects against heart damage caused by BPA, an environmental pollutant. Thus, it was supported that GA could be a potential cardioprotective agent.

Paeoniflorin loaded liposomes modified with glycyrrhetinic acid for liver-targeting: preparation, characterization, and pharmacokinetic study.

OBJECTIVE: To enhance the retention times and therapeutic efficacy of paeoniflorin (PF), a liver-targeted drug delivery system has been developed using glycyrrhetinic acid (GA) as a ligand. SIGNIFICANCE: The development and optimization of GA-modified PF liposomes (GPLs) have shown promising potential for targeted delivery to the liver, opening up new possibilities for liver disease treatment. METHODS: This study aimed to identify the best prescriptions using single-factor experiments and response surface methodology. The formulation morphology was determined using transmission electron microscopy. Tissue distribution was observed through in vivo imaging, and pharmacokinetic studies were conducted. RESULTS: The results indicated that GPLs, prepared using the thin film dispersion method and response surface optimization, exhibited well-dispersed and uniformly sized particles. The in vitro release rate of GPLs was slower compared to PF monomers, suggesting a sustained release effect. The liver-targeting ability of GA resulted in stronger fluorescence signals in the liver for targeted liposomes compared to non-targeted liposomes. Furthermore, pharmacokinetic studies demonstrated that GPLs significantly prolonged the residence time of PF in the bloodstream, thereby contributing to prolonged efficacy. CONCLUSION: These findings suggest that GPLs are more effective than PF monomers in terms of controlling drug release and delivering drugs to specific targets, highlighting the potential of PF as a liver-protective drug.

Gancao decoction attenuates hepatic necroptosis via activating caspase 8 in cholestatic liver injury.

ETHNOPHARMACOLOGICAL RELEVANCE: Gancao Decoction (GCD) is widely used to treat cholestatic liver injury. However, it is unclear whether is related to prevent hepatocellular necroptosis. AIM OF THE STUDY: The purpose of this study is to clarify the therapeutic effects of GCD against hepatocellular necroptosis induced by cholestasis and its active components. MATERIALS AND METHODS: We induced cholestasis model in wild type mice by ligating the bile ducts or in Nlrp3-/- mice by intragastrical administering Alpha-naphthylisothiocyanate (ANIT). Serum biochemical indices, liver pathological changes and hepatic bile acids (BAs) were measured to evaluate GCD's hepatoprotective effects. Necroptosis was assessed by expression of hallmarkers in mice liver. Moreover, the potential anti-necroptotic effect of components from GCD were investigated and confirmed in ANIT-induced cholestasis mice and in primary hepatocytes from WT mouse stimulated with Tumor Necrosis Factor alpha (TNF-α) and cycloheximide (CHX). RESULTS: GCD dose-dependently alleviated hepatic necrosis, reduced serum aminotranferase activity in both BDL and ANIT-induced cholestasis models. More importantly, the expression of hallmarkers of necroptosis, including MLKL, RIPK1 and RIPK3 phosphorylation (p- MLKL, p-RIPK1, p-RIPK3) were reduced upon GCD treatment. Glycyrrhetinic acid (GA), the main bioactive metabolite of GCD, effectively protected against ANIT-induced cholestasis, with decreased expression of p-MLKL, p-RIPK1 and p-RIPK3. Meanwhile, the expression of Fas-associated death domain protein (FADD), long isoform of cellular FLICE-like inhibitory protein (cFLIPL) and cleaved caspase 8 were upregulated upon GA treatment. Moreover, GA significantly increased the expression of active caspase 8, and reduced that of p-MLKL in TNF-α/CHX induced hepatocytes necroptosis. CONCLUSIONS: GCD substantially inhibits necroptosis in cholestatic liver injury. GA is the main bioactive component responsible for the anti-necroptotic effects, which correlates with upregulation of c-FLIPL and active caspase 8.

Natural Sweetener, Glycyrrhetinic Acid 3-O-Mono-beta-d-glucuronide, for Postprandial Hyperglycemia Management.

This study examines the inhibitory effects of a range of sweeteners on α-glucosidase. Our findings revealed that only one natural sweetener, namely, glycyrrhetinic acid 3-O-mono-beta-d-glucuronide (GAMG), derived from licorice, exhibited a mixed-type inhibition against α-glucosidase with a IC50 value of 0.73 ± 0.05 mg/mL. The fluorescence intensity of α-glucosidase was quenched by GAMG in the formation of an α-glucosidase-GAMG complex. GAMG has been shown to induce conformational changes in α-glucosidase, likely through hydrogen bonding, van der Waals force, and alkyl-alkyl interactions with amino acid residues, including Arg 281, Leu 283, Trp 376, Asp 404, Asp 443, Trp 481, Asp 518, Phe 525, Ala 555, and Asp 616. Additional animal validation experiments demonstrated that GAMG slowed starch digestion, thereby attenuating the postprandial glycemic response. Taken together, these findings provide evidence that GAMG is a natural sweetener with potent inhibitory activity that selectively targets α-glucosidase. This study supports the use of GAMG as a natural sweetener, which holds a high biological value and may be beneficial for managing postprandial hyperglycemia.

Natural Sweetener Glycyrrhetinic Acid Monoglucuronide Improves Glucose Homeostasis in Healthy Mice.

Noncaloric or low-caloric sweeteners have become popular worldwide, although debates persist regarding their impact on health. To investigate whether the sweeteners are favorable for glucose homeostasis, our study assessed the effects of glycyrrhetinic acid monoglucuronide (GAMG) and several commonly used sweeteners [glycyrrhetinic acid (GA), stevioside, erythritol, sucralose, and aspartame] on glycometabolism and elucidated the underlying mechanisms. The C57BL/6J male mice were exposed to different sweeteners for 10 weeks, and our results showed that GAMG significantly reduced fasting blood glucose (FBG) levels (FBG-control: 3.81 ± 0.42 mmol/L; FBG-GAMG: 3.37 ± 0.38 mmol/L; p < 0.05) and the blood glucose levels 15 and 30 min after sucrose or maltose loading (p < 0.05). Furthermore, it improved glucose tolerance (p = 0.028) and enhanced insulin sensitivity (p = 0.044), while the other sweeteners had negligible or adverse effects on glucose homeostasis. Subsequent experiments showed that GAMG inhibited α-glucosidases potently (IC50 = 0.879 mg·mL-1), increased three SCFA-producing bacteria and SCFAs levels (p < 0.05), and promoted the gene expression of SCFA receptor GPR43 (p = 0.018). These results suggest that GAMG may regulate blood glucose by inhibiting α-glucosidases and modulating gut microbial SCFAs. Our findings prove that GAMG, beneficial to blood glucose regulation, is a promising natural sweetener for future utilization.

Novel two-tiered screening approach identifies synergistic combinations of natural compounds for prostate cancer prevention and treatment.

Prostate cancer (PCa) is the second most common cancer type among American men and it is estimated that in 2023, 34,700 men will die from PCa. Since it can take a considerable amount of time for the disease to progress to clinically evident cancer, there is ample opportunity for effective chemopreventive strategies to be applied for the successful management of PCa progression. In the current study, we have developed a two-tiered metabolomics-based screen to identify synergistic combinations of phytochemicals for PCa chemoprevention. This involves an initial screen for ATP depletion in PCa cells followed by a targeted screen for blocking glutamine uptake in the same cells. One of the phytochemical combinations (enoxolone [ENO] + silibinin [SIL]), identified via this screen, was examined for effects on PCa cell survival, oncogenic signaling and tumor growth in vivo. This combination was found to synergistically reduce cell survival, colony formation and cell cycle progression of PCa cell lines to a greater extent than either agent alone. The combination of ENO and SIL also synergistically reduced tumor growth when administered ad libitum through the diet in a HMVP2 allograft PCa tumor model. Treatment with the combination also significantly reduced STAT3 and mTORC1 signaling pathways in mouse and human PCa cells while significantly reducing levels of critical cell cycle regulatory proteins, contributing to the synergistic inhibition of tumor growth observed. Collectively, the current results demonstrate a novel approach to identifying synergistic combinations of phytochemicals for chemoprevention of PCa and possibly other cancers.

Ursodeoxycholic acid and 18ß-glycyrrhetinic acid alleviate ethinylestradiol-induced cholestasis via downregulating RORγt and CXCR3 signaling pathway in iNKT cells.

Estrogen-induced intrahepatic cholestasis (IHC) is a mild but potentially serious risk and urges for new therapeutic targets and effective treatment. Our previous study demonstrated that RORγt and CXCR3 signaling pathway of invariant natural killer T (iNKT) 17 cells play pathogenic roles in 17α-ethinylestradiol (EE)-induced IHC. Ursodeoxycholic acid (UDCA) and 18ß-glycyrrhetinic acid (GA) present a protective effect on IHC partially due to their immunomodulatory properties. Hence in present study, we aim to investigate the effectiveness of UDCA and 18ß-GA in vitro and verify the accessibility of the above targets. Biochemical index measurement indicated that UDCA and 18ß-GA presented efficacy to alleviate EE-induced cholestatic cytotoxicity. Both UDCA and 18ß-GA exhibited suppression on the CXCL9/10-CXCR3 axis, and significantly restrained the expression of RORγt in vitro. In conclusion, our observations provide new therapeutic targets of UDCA and 18ß-GA, and 18ß-GA as an alternative treatment for EE-induced cholestasis.

Low temperature promotes the production and efflux of terpenoids in yeast.

Altering the fermentation environment provides an effective approach to optimizing the production efficiency of microbial cell factories globally. Here, lower fermentation temperatures of yeast were found to significantly improve the synthesis and efflux of terpenoids, including glycyrrhetinic acid (GA), ß-caryophyllene, and α-amyrin. The production of GA at 22°C increased by 5.5 times compared to 30°C. Yeast subjected to lower temperature showed substantial changes at various omics levels. Certain genes involved in maintaining cellular homeostasis that were upregulated under the low temperature conditions, leading to enhanced GA production. Substituting Mvd1, a thermo-unstable enzyme in mevalonate pathway identified by transcriptome and proteome, with a thermo-tolerant isoenzyme effectively increased GA production. The lower temperature altered the composition of phospholipids and increased the unsaturation of fatty acid chains, which may influence GA efflux. This study presents a strategy for optimizing the fermentation process and identifying key targets of cell factories for terpenoid production.

Network pharmacology mechanisms and experimental verification of licorice in the treatment of ulcerative colitis.

ETHNOPHARMACOLOGICAL RELEVANCE: Licorice is widely used in the treatment of ulcerative colitis (UC) and has good antioxidant and anti-inflammatory effects, but its specific active ingredients and mechanisms of action are still unknown. THE PURPOSE OF THE STUDY: To elucidate the specific molecular mechanisms of licorice in the treatment of UC and to experimentally verify its activity. METHODS: Through network pharmacology, the active ingredients of licorice and the molecular targets of UC were identified. A traditional Chinese medicine (TCM)-components-target-disease network diagram was established, and the binding energies of the active ingredient and targets of licorice were verified by molecular docking. A BALB/c mice model of UC was established by treatment with 3% dextran sulfate sodium (DSS). The effect of licorice on colon tissue injury was histologically assessed. The expression of IL-6 and IL-17 in colon tissue was detected by immunohistochemistry (IHC). Transmission electron microscopy (TEM) was used to observe morphological changes in mitochondria in the colon. Caco2 cells were treated with lipopolysaccharide (LPS) for 24 h to establish the cell inflammatory damage model, and cells were exposed to different concentrations of drug-containing serum of Licorice (DCSL) for 24 h. In cells treated with the drug, the contents of oxidation markers were measured and ELISA was used to determine the levels of inflammatory factors in the cells. TEM was used to observe morphological changes in mitochondria. ZO-1 and occludin were detected by Western blotting. DCSL effects on autophagy were evaluated by treating cells with DCSL and autophagy inhibitor for 24 h after LPS injection. Small interfering ribonucleic acid (si-RNA) was used to silence Nrf2 gene expression in Caco2 cells to observe the effects of DCSL on autophagy through the Nrf2/PINK1 pathway. Nrf2, PINK1, HO-1, Parkin, P62, and LC3 were detected by Western blotting. RESULTS: Ninety-one active ingredients and 339 action targets and 792 UC disease targets were identified, 99 of which were overlapping targets. Molecular docking was used to analyze the binding energies of liquiritin, liquiritigenin, glycyrrhizic acid, and glycyrrhetinic acid to the targets, with glycyrrhetinic acid having the strongest binding energy. In the UC mouse model, licorice improved colon histopathological changes, reduced levels of IL-6 and IL-17 and repaired mitochondrial damage. In the LPS-induced inflammation model of Caco2 cells, DCSL decreased MDA, IL-1ß, Il-6, and TNF-α levels and increased those of Superoxide Dismutase (SOD), glutathione peroxidase (GSH-PX), and IL-10, and improved the morphological changes of mitochondria. Increased expression of Nrf2, PINK1, Parkin, HO-1, ZO-1, occludin, P62, and LC3 promoted autophagy and reduced inflammation levels. CONCLUSION: Licorice improves UC, which may be related to the activation of the Nrf2/PINK1 signaling pathway that regulates autophagy.

Flubendazole carbonyl reduction in drug-susceptible and drug-resistant strains of the parasitic nematode Haemonchus contortus: changes during the life cycle and possible inhibition.

Carbonyl-reducing enzymes (CREs) catalyse the reduction of carbonyl groups in many eobiotic and xenobiotic compounds in all organisms, including helminths. Previous studies have shown the important roles of CREs in the deactivation of several anthelmintic drugs (e.g., flubendazole and mebendazole) in adults infected with the parasitic nematode Haemonchus contortus, in which the activity of a CRE is increased in drug-resistant strains. The aim of the present study was to compare the abilities of nematodes of both a drug-susceptible strain (ISE) and a drug-resistant strain (IRE) to reduce the carbonyl group of flubendazole (FLU) in different developmental stages (eggs, L1/2 larvae, L3 larvae, and adults). In addition, the effects of selected CRE inhibitors (e.g., glycyrrhetinic acid, naringenin, silybin, luteolin, glyceraldehyde, and menadione) on the reduction of FLU were evaluated in vitro and ex vivo in H. contortus adults. The results showed that FLU was reduced by H. contortus in all developmental stages, with adult IRE females being the most metabolically active. Larvae (L1/2 and L3) and adult females of the IRE strain reduced FLU more effectively than those of the ISE strain. Data from the in vitro inhibition study (performed with cytosolic-like fractions of H. contortus adult homogenate) revealed that glycyrrhetinic acid, naringenin, mebendazole and menadione are effective inhibitors of FLU reduction. Ex vivo study data showed that menadione inhibited FLU reduction and also decreased the viability of H. contortus adults to a similar extent. Naringenin and mebendazole were not toxic at the concentrations tested, but they did not inhibit the reduction of FLU in adult worms ex vivo.

A glycyrrhetinic acid-iridium(III) conjugate as a theranostic NIR probe for hepatocellular carcinoma with mitochondrial-targeting ability.

Hepatocellular carcinoma (HCC) is a major contributor to global mortality rates, but current treatment options have limitations. Advanced theranostics are needed to effectively integrate diagnosis and therapeutic of HCC. Glycyrrhetinic acid (GA) has abundant binding sites with glycyrrhetinic acid receptors (GA-Rs) on the surface of HCC cells and has also been reported to possess ligands with mitochondrial-targeting capability but with limited efficacy. Herein, we report a near-infrared (NIR) luminescent theranostic complex 1 through conjugating an iridium(III) complex to GA, which exhibits the desired photophysical properties and promotes mitochondrial-targeting capability. Complex 1 was selectively taken up by HepG2 liver cancer cells and was imaged within mitochondria with NIR emission. Complex 1 targeted mitochondria and opened mitochondrial permeability transition pores (MPTPs), resulting in ROS accumulation, mitochondrial damage, disruption of Bax/Bcl-2 equilibrium, and tumor cell apoptosis, resulting in significantly improved anticancer activity compared to GA. This work offers a methodology for developing multifunctional theranostic probes with amplified specificity and efficacy.

Licorice metabolite 18ß-glycyrrhetinic acid activates G protein-gated inwardly rectifying K+ channels.

BACKGROUND AND PURPOSE: Licorice (liquorice) is a common food additive and is used in Chinese medicine. Excess licorice intake can induce atrial fibrillation. Patients with atrial fibrillation possess constitutively activated G protein-gated inwardly rectifying K+ (GIRK) channels. Whether licorice affects GIRK channel activity is unknown. We aimed to clarify the effects of licorice ingredients on GIRK current and the mechanism of action. EXPERIMENTAL APPROACH: A major component of licorice, glycyrrhizic acid (GA), and its metabolite, 18ß-glycyrrhetinic acid (18ß-GA), were tested. We performed electrophysiological recordings in Xenopus oocytes to examine the effects of GA and 18ß-GA on various GIRK subunits (Kir 3.1-Kir 3.4), mutagenesis analyses to identify the crucial residues for drug action and motion analysis in cultured rat atrial myocytes to clarify effects of 18ß-GA on atrial functions. KEY RESULTS: GA inhibited Kir 3.1-containing channels, while 18ß-GA activated all Kir 3.x subunits. A pore helix residue Phe137 in Kir 3.1 was critical for GA-mediated inhibition, and the corresponding Ser148 in Kir 3.2 was critical for 18ß-GA-mediated activation. 18ß-GA activated GIRK channel in a Gßγ -independent manner, whereas phosphatidylinositol 4,5-bisphosphate (PIP2 ) was essential for activation. Glu236 located at the cytoplasmic pore of Kir 3.2 appeared to be important to interactions with 18ß-GA. In rat atrial myocytes, 18ß-GA suppressed spontaneous beating via activation of GIRK channels. CONCLUSION AND IMPLICATIONS: GA acts as a novel GIRK inhibitor, and 18ß-GA acts as a novel GIRK activator. 18ß-GA alters atrial function via activation of GIRK channels. This study elucidates the pharmacological activity of licorice ingredients and provides information for drug design.

Glycyrrhetinic Acid Mitigates Radiation-Induced Pulmonary Fibrosis via Inhibiting the Secretion of TGF-ß1 by Treg Cells.

PURPOSE: Radiation-induced pulmonary fibrosis (RIPF) is a common side effect of radiation therapy for thoracic tumors without effective prevention and treatment methods at present. The aim of this study was to explore whether glycyrrhetinic acid (GA) has a protective effect on RIPF and the underlying mechanism. METHODS AND MATERIALS: A RIPF mouse model administered GA was used to determine the effect of GA on RIPF. The cocultivation of regulatory T (Treg) cells with mouse lung epithelial-12 cells or mouse embryonic fibroblasts and intervention with GA or transforming growth factor-ß1 (TGF-ß1) inhibitor to block TGF-ß1 was conducted to study the mechanism by which GA alleviates RIPF. Furthermore, injection of Treg cells into GA-treated RIPF mice to upregulate TGF-ß1 levels was performed to verify the roles of TGF-ß1 and Treg cells. RESULTS: GA intervention improved the damage to lung tissue structure and collagen deposition and inhibited Treg cell infiltration, TGF-ß1 levels, epithelial mesenchymal transition (EMT), and myofibroblast (MFB) transformation in mice after irradiation. Treg cell-induced EMT and MFB transformation in vitro were prevented by GA, as well as a TGF-ß1 inhibitor, by decreasing TGF-ß1. Furthermore, reinfusion of Treg cells upregulated TGF-ß1 levels and exacerbated RIPF in GA-treated RIPF mice. CONCLUSIONS: GA can improve RIPF in mice, and the corresponding mechanisms may be related to the inhibition of TGF-ß1 secreted by Treg cells to induce EMT and MFB transformation. Therefore, GA may be a promising therapeutic candidate for the clinical treatment of RIPF.

[Liver targeting of compound liposomes mediated by glycyrrhetinic acid derivative receptor and its effect on hepatic stellate cells].

The 3-succinate-30-stearyl glycyrrhetinic acid(18-GA-Suc) was inserted into glycyrrhetinic acid(GA)-tanshinone Ⅱ_A(TSN)-salvianolic acid B(Sal B) liposome(GTS-lip) to prepare liver targeting compound liposome(Suc-GTS-lip) mediated by GA receptors. Next, pharmacokinetics and tissue distribution of Suc-GTS-lip and GTS-lip were compared by UPLC, and in vivo imaging tracking of Suc-GTS-lip was conducted. The authors investigated the effect of Suc-GTS-lip on the proliferation inhibition of hepatic stellate cells(HSC) and explored their molecular mechanism of improving liver fibrosis. Pharmacokinetic results showed that the AUC_(Sal B) decreased from(636.06±27.73) µg·h·mL~(-1) to(550.39±12.34) µg·h·mL~(-1), and the AUC_(TSN) decreased from(1.08±0.72) µg·h·mL~(-1) to(0.65±0.04) µg·h·mL~(-1), but the AUC_(GA) increased from(43.64±3.10) µg·h·mL~(-1) to(96.21±3.75) µg·h·mL~(-1). The results of tissue distribution showed that the AUC_(Sal B) and C_(max) of Sal B in the liver of the Suc-GTS-lip group were 10.21 and 4.44 times those of the GTS-lip group, respectively. The liver targeting efficiency of Sal B, TSN, and GA in the Suc-GTS-lip group was 40.66%, 3.06%, and 22.08%, respectively. In vivo imaging studies showed that the modified liposomes tended to accumulate in the liver. MTT results showed that Suc-GTS-lip could significantly inhibit the proliferation of HSC, and RT-PCR results showed that the expression of MMP-1 was significantly increased in all groups, but that of TIMP-1 and TIMP-2 was significantly decreased. The mRNA expressions of collagen-I and collagen-Ⅲ were significantly decreased in all groups. The experimental results showed that Suc-GTS-lip had liver targeting, and it could inhibit the proliferation of HSC and induce their apoptosis, which provided the experimental basis for the targeted treatment of liver fibrosis by Suc-GTS-lip.

Glycyrrhetinic Acid Receptor-Mediated Zeolitic Imidazolate Framework-8 Loaded Doxorubicin as a Nanotherapeutic System for Liver Cancer Treatment.

In this study, we designed and developed a DOX nanodrug delivery system (PEG-GA@ZIF-8@DOX) using ZIF-8 as the carrier and glycyrrhetinic acid (GA) as the targeting ligand. We confirmed that DOX was loaded and PEG-GA was successfully modified on the surface of the nanoparticles. The in vitro release profile of the system was investigated at pH 5.0 and 7.4. The cellular uptake, in vitro cytotoxicity, and lysosomal escape characteristics were examined using HepG2 cells. We established an H22 tumor-bearing mouse model and evaluated the in vivo antitumor activity. The results showed that the system had a uniform nanomorphology. The drug loading capacity was 11.22 ± 0.87%. In acidic conditions (pH 5.0), the final release rate of DOX was 57.73%, while at pH 7.4, it was 25.12%. GA-mediated targeting facilitated the uptake of DOX by the HepG2 cells. PEG-GA@ZIF-8@DOX could escape from the lysosomes and release the drug in the cytoplasm, thus exerting its antitumor effect. When the in vivo efficacy was analyzed, we found that the tumor inhibition rate of PEG-GA@ZIF-8@DOX was 67.64%; it also alleviated the loss of the body weight of the treated mice. This drug delivery system significantly enhanced the antitumor effect of doxorubicin in vitro and in vivo, while mitigating its toxic side effects.

Revisiting Licorice as a functional food in the management of neurological disorders: Bench to trend.

Traditional and scientific evidence attribute numerous bioactivities of Licorice (Glycyrrhiza glabra Linn.) in aging-related disorders. In this state-of-art review, an extensive search in several databases was conducted to collect all relevant literature and comprehensively analyze Licorice's pharmacological attributes, neuroprotective properties, safety, and its mechanistic role in treating various neurological conditions. Network pharmacology was employed for the first time exploring the mechanistic role of Licorice in neurological disorders. Its neuroprotective role is attributed to phytoconstituents, including liquiritin, glycyrrhizic acid, liquiritigenin, glabridin, 18ß-glycyrrhetinic acid, quercetin, isoliquiritigenin, paratocarpin B, glycyglabrone, and hispaglabridin B, as evident from in vitro and in vivo studies. Network pharmacology analysis reveals that these compounds protect against long-term depression, aging-associated diseases, Alzheimer's disease, and other addictions through interactions with cholinergic, dopaminergic, and serotonergic proteins, validated in animal studies only. Future clinical trials are warranted as Licorice administration has a limiting factor of mild hypertension and hypokalemia. Hopefully, scientific updates on Licorice will propagate a paradigm shift in medicine, research propagation, and development of the central nervous system phytopharmaceuticals.

Glycyrrhetinic acid attenuates endoplasmic reticulum stress-induced hepatocyte apoptosis via CHOP/DR5/Caspase 8 pathway in cholestasis.

Bile acid (BA)-induced apoptosis is a common pathologic feature of cholestatic liver injury. Glycyrrhetinic acid (GA) is the hepatoprotective constituent of licorice. In the present study, the anti-apoptotic potential of GA was investigated in wild type and macrophage-depleted C57BL/6 mice challenged with alpha-naphthyl isothiocyanate (ANIT), and hepatocytes stimulated with Taurocholic acid (TCA) or Tumor necrosis factor-alpha (TNF-α). Apoptosis was determined by TUNEL positive cells and expression of executioner caspases. Firstly, we found that GA markedly alleviated liver injury, accompanied with reduced positive TUNEL-staining cells, and expression of caspases 3, 8 and 9 in mice modeled with ANIT. Secondly, GA mitigated apoptosis in macrophage-depleted mice with exacerbated liver injury and augmented cell apoptosis. In vitro study, pre-treatment with GA reduced the expression of activated caspases 3 and 8 in hepatocytes stimulated with TCA, but not TNF-α. The ability of GA to ameliorate apoptosis was abolished in the presence of Tauroursodeoxycholic Acid (TUDCA), a chemical chaperon against Endoplasmic reticulum stress (ER stress). Furthermore, GA attenuated the over-expression of Glucose regulated protein 78 (GRP78), and blocked all three branches of Unfolded protein reaction (UPR) in cholestatic livers of mice induced by ANIT. GA also downregulated C/EBP homologous protein (CHOP) expression, accompanied with reduced expression of Death receptor 5 (DR5) and activation of caspase 8 in both ANIT-modeled mice and TCA-stimulated hepatocytes. The results indicate that GA inhibits ER stress-induced hepatocyte apoptosis in cholestasis, which correlates with blocking CHOP/DR5/Caspase 8 pathway.