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.

18-ß-Glycyrrhetinic Acid Promotes Hair Growth by Stimulating the Proliferation of Dermal Papilla Cells and Outer Root Sheath Cells, and Extends the Anagen Phase by Inhibiting 5α-Reductase.

18-ß-Glycyrrhetinic acid, a major component of licorice, stimulated the proliferation of both dermal papilla cells and outer root sheath cells isolated from human hair follicles. Thus, suggesting that this compound promotes hair growth. Furthermore, this compound inhibited the activity of testosterone 5α-reductase, an enzyme responsible for converting androgen to dihydroandrogen, with an IC50 of 137.1 µM. 18-ß-Glycyrrhetinic acid also suppressed the expression of transforming growth factor-ß1 (TGF-ß1), which shifts the hair cycle from the anagen phase to the telogen phase. It suggested that this compound may prolong the anagen phase. Based on these findings, this compound could be a potentially effective treatment for androgenetic alopecia.

Synthesis, characterization and anticancer, antibacterial activities of pentacyclic triterpenoid glycoside derivatives.

As a kind of glycoside, pentacyclic triterpenoid saponins have good biological activities, such as anticancer, antibacterial, antiviral and hypoglycemic effects [1]. In this paper, twenty-four pentacyclic triterpenoid derivatives, including twelve monosaccharide derivatives, were designed and synthesized. The anticancer effect and antibacterial activities of all compounds were evaluated. It is noteworthy that compound UA-2b has the strongest inhibitory effect on the growth of A549, Hela and HepG2 cancer cells (IC50 = 5.37 ± 0.22 µM, 5.82 ± 0.25 µM and 5.47 ± 0.06 µM, respectively). Compounds OA-2b, OA-6a, OA-6b, UA-2b and UA-6a have the best activity against Escherichia coli 1924 (MIC = 16 µg/ml).

Structure-Activity Relationship of Oleanane-Type Pentacyclic Triterpenoids on Nuclear Factor κB Activation and Intracellular Trafficking and N-Linked Glycosylation of Intercellular Adhesion Molecule-1.

In our previous study, two oleanane-type pentacyclic triterpenoids (oleanolic acid and maslinic acid) were reported to affect the N-glycosylation and intracellular trafficking of intercellular adhesion molecule-1 (ICAM-1). The present study was aimed at investigating the structure-activity relationship of 13 oleanane-type natural triterpenoids with respect to the nuclear factor κB (NF-κB) signaling pathway and the expression, intracellular trafficking, and N-glycosylation of the ICAM-1 protein in human lung adenocarcinoma A549 cells. Hederagenin, echinocystic acid, erythrodiol, and maslinic acid, which all possess two hydroxyl groups, decreased the viability of A549 cells. Celastrol and pristimerin, both of which possess an α,ß-unsaturated carbonyl group, decreased cell viability but more strongly inhibited the interleukin-1α-induced NF-κB signaling pathway. Oleanolic acid, moronic acid, and glycyrrhetinic acid interfered with N-glycosylation without affecting the cell surface expression of the ICAM-1 protein. In contrast, α-boswellic acid and maslinic acid interfered with the N-glycosylation of the ICAM-1 protein, which resulted in the accumulation of high-mannose-type N-glycans. Among the oleanane-type triterpenoids tested, α-boswellic acid and maslinic acid uniquely interfered with the intracellular trafficking and N-glycosylation of glycoproteins.

Efficacy of Glycyrrhetinic Acid in the Treatment of Acne Vulgaris Based on Network Pharmacology and Experimental Validation.

Glycyrrhetinic acid (GA) is a saponin compound, isolated from licorice (Glycyrrhiza glabra), which has been wildly explored for its intriguing pharmacological and medicinal effects. GA is a triterpenoid glycoside displaying an array of pharmacological and biological activities, including anti-inflammatory, anti-bacterial, antiviral and antioxidative properties. In this study, we investigated the underlying mechanisms of GA on acne vulgaris through network pharmacology and proteomics. After the intersection of the 154 drug targets and 581 disease targets, 37 therapeutic targets for GA against acne were obtained. A protein-protein interaction (PPI) network analysis highlighted TNF, IL1B, IL6, ESR1, PPARG, NFKB1, STAT3 and TLR4 as key targets of GA against acne, which is further verified by molecular docking. The experimental results showed that GA inhibited lipid synthesis in vitro and in vivo, improved the histopathological damage of skin, prevented mast cell infiltration and decreased the level of pro-inflammatory cytokines, including TNF-α, IL-1ß and IL-6. This study indicates that GA may regulate multiple pathways to improve acne symptoms, and the beneficial effects of GA against acne vulgaris might be through the regulation of sebogenesis and inflammatory responses.

Inactivation of EGFR/ERK/NF-κB signalling associates with radiosensitizing effect of 18ß-glycyrrhetinic acid on progression of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is recognized as the fifth most common cancer and the third most common cause of death in Asian population. Studies reported that HCC is relatively insensitive to radiotherapy (RT); thus, considering how to sensitize HCC to RT is worth to be elucidated. Epidermal growth factor receptor (EGFR)-mediated signalling transduction plays the important role in regulating treatment efficacy of HCC. An active compound, 18beta-glycyrrhetinic acid (18ß-GA), has been reported to own anti-tumour effect. However, whether 18ß-GA possess RT sensitization ability in HCC remains unclear. Here, we used RNA data from TCGA-LIHC (Liver hepatocellular carcinoma) to identify the role between EGFR/ERK/nuclear factor kappa B (NF-κB) signalling and RT by radiosensitivity index (RSI) analysis. We suggested that patients with activated NF-κB signalling may show resistance to RT treatment, whereas combining 18ß-GA may reinforce RT efficacy in a Hep3B-bearing animal model. 18ß-GA combined with RT showed superior tumour inhibition capacity as compared to monotherapy and even reached similar efficacy as erlotinib combined with RT. Treatment promotion of RT by 18ß-GA in HCC is not only through diminishing RT-induced EGFR/ERK/NF-κB signalling but also promoting RT-induced apoptosis pathways. 18ß-GA may act as radiosensitizer through inactivating EGFR-mediated HCC progression and inducing caspase-dependent apoptosis signalling.

Glycyrrhetinic acid prevents carbapenem-resistant Klebsiella pneumoniae-induced cell injury by inhibiting mitochondrial dysfunction via Nrf-2 pathway.

OBJECTIVES: Due to the abuse of antibiotics, the high reoccurrence of drug-resistance strains, such as carbapenem-resistant Klebsiella pneumoniae (CRKP), deteriorates CRKP-infected pneumonia in the clinic, suggesting it is necessary to find new alternatives. Glycyrrhetinic acid (GA), an active ingredient of Yinhuapinggan granule, has antioxidant & anti-inflammatory capacity. Little, however, is known about the effects of GA on CRKP-induced epithelial injury. METHODS: In this research, we examined the protective effects of GA against pulmonary epithelium damage caused by CRKP infection and potential molecular mechanisms. RESULTS: Our results noted GA significantly promoted cell survival and reduced pro-inflammatory cytokines production, during CRKP-induced human pulmonary epithelial cell. Mechanically, GA alleviated mitochondrial-damage-induced apoptosis amid CRKP infection by inhibiting mitochondrial damage. Additionally, we found GA inhibited the expression of pro-apoptotic proteins Cyto-c, the Bax, and Caspase-3 while increasing the expression of anti-apoptotic protein Bcl-2. Further exploration found GA could trigger Nrf-2 expression at both gene and protein levels, activating antioxidative proteins to diminish CRKP-induced oxidative stress. CONCLUSION: Together, our results demonstrated that GA was a promising candidate to alleviate CRKP-infected lung injury as well as a synergist to treat CRKP infection with antibiotics.

18ß-Glycyrrhetinic Acid Ameliorates Neuroinflammation Linked Depressive Behavior Instigated by Chronic Unpredictable Mild Stress via Triggering BDNF/TrkB Signaling Pathway in Rats.

Evidence shows that inflammatory responses may encompass the onset of severe depressive illness. Traditionally used licorice contains 18ß-glycyrrhetinic acid (18ßGA), which has been demonstrated to reduce inflammation and oxidative stress. This study investigates the antidepressant effects of 18ßGA and the underlying mechanism in rats exposed to chronic unpredictable mild stress (CUMS). Wistar rats were exposed to CUMS for 36 consecutive days to establish depression. 18ßGA (10, 20, and 50 mg/kg) or fluoxetine was given once daily (from day 30 to day 36). Thereafter, behavior parameters (sucrose preference test, forced-swimming test, open-field test, body weight), pro-inflammatory cytokines, neurotransmitters, adrenocorticotropic hormone (ACTH), corticosterone (CORT), and liver biomarkers were studied. Immunohistochemistry and western blot analyses were conducted to investigate the protein's expression. 18ßGA (20 and 50 mg/kg) treatment increased sucrose intake, locomotion in the open-field test, decreased immobility time in the forced swim test, and improved body weight in CUMS-exposed rats. The therapy of 18ßGA dramatically declined cytokines, ACTH and CORT and improved 5HT and norepinephrine in CUMS rats. Furthermore, BDNF and TrkB proteins were down-regulated in CUMS group, which was increased to varying degrees by 18ßGA at doses of 20 and 50 mg/kg. Therefore, 18ßGA ameliorates depressive-like behavior persuaded by chronic unpredictable mild stress, decreases neuroinflammation, liver biomarkers, stress hormones, and improves body weight, brain neurotransmitter concentration via activating on BDNF/TrkB signaling pathway in both PFC and hippocampus in rats.

Dual-Ligand-Functionalized Liposomes Based on Glycyrrhetinic Acid and cRGD for Hepatocellular Carcinoma Targeting and Therapy.

Hepatocellular carcinoma (HCC) is one of the most common cancers, with high mortality. Chemotherapy is one of the main treatment options for HCC. However, the high toxicity and poor specificity of chemotherapeutic drugs have limited their clinical application. In this study, dual-ligand liposomes modified with glycyrrhetinic acid (GA) and cyclic arginine-glycine-aspartic acid (cRGD) (GA/cRGD-LP) were designed to target the GA receptor and αvß3 integrin, respectively. The aim was to develop a highly selective targeted drug delivery system and further enhance the antitumor efficiency of drugs by targeting both hepatic tumor cells and vasculature. A novel lipid conjugate (mGA-DOPE) by coupling dioleoylphosphatidyl ethanolamine (DOPE) with methyl glycyrrhetinic acid (mGA) was synthesized, and its structure was confirmed. The targeting efficiency of GA/cRGD-LP by in vitro cellular uptake and ex vivo imaging was assessed. GA- and cRGD-modified doxorubicin-loaded liposomes (GA/cRGD-LP-DOX) were prepared, and their cytotoxicity in HepG2 and antitumor activity were evaluated. The results showed that the average particle size of the GA/cRGD-LP-DOX was 114 ± 4.3 nm, and the zeta potential was -32.9 ± 2.0 mV. The transmission electron microscopy images showed that the shapes of our liposomes were spherical. cGA/cRGD-LP-DOX displayed an excellent cellular uptake in both HepG2 and human umbilical vein endothelial cells. In the in vivo study, pharmacokinetic parameters indicated that cGA/cRGD-LP can prolong the circulation time of DOX in the blood. GA/cRGD-LP-DOX showed greater inhibition of tumor growth for HepG2-bearing mice than either the single-ligand-modified liposomes or nontargeted liposomes. GA/cRGD-LP-DOX displayed higher liver tumor localization than that of single-ligand-modified liposomes or free DOX. GA/cRGD-LP is a promising drug delivery system for liver cancer targeting and therapy and is worthy of further study.

Design and synthesis of novel anti-multidrug-resistant staphylococcus aureus derivatives of glycyrrhetinic acid by blocking arginine biosynthesis, metabolic and H2S biogenesis.

With the soaring number of multidrug-resistant bacteria, it is imperative to develop novel efficient antibacterial agents and discovery new antibacterial pathways. Herein, we designed and synthesized a series of structurally novel glycyrrhetinic acid (GA) derivatives against multidrug-resistant Staphylococcus aureus (MRSA). The in vitro antibacterial activity of these compounds was evaluated using the microbroth dilution method, agar plate coating experiments and real-time growth curves, respectively. Most of the target derivatives showed moderate antibacterial activity against Staphylococcus aureus (S. aureus) and MRSA (MIC = 3.125-25 µM), but inactivity against Escherichia coli (E. Coli) and Pseudomonas aeruginosa (P. aeruginosa) (MIC > 200 µM). Among them, compound 11 had the strongest antibacterial activity against MRSA, with an MIC value of 3.125 µM, which was 32 times and 64 times than the first-line antibiotics penicillin and norfloxacin, respectively. Additionally, transcriptomic (RNA-seq) and quantitative polymerase chain reaction (qPCR) analysis revealed that the antibacterial mechanism of compound 11 was through blocking the arginine biosynthesis and metabolic and the H2S biogenesis. Importantly, compound 11 was confirmed to have good biocompatibility through the in vitro hemolysis tests, cytotoxicity assays and the in vivo quail chicken chorioallantoic membrane (qCAM) experiments. Current study provided new potential antibacterial candidates from glycyrrhetinic acid derivatives for clinical treatment of MRSA infections.

18ß-glycyrrhetinic Acid Modulated Autophagy is Cytotoxic to Breast Cancer Cells.

The development of endocrine therapy resistance in the luminal A subtype of breast cancer is related to the appearance of protective autophagy. The bioactive component from the root of licorice, 18ß-glycyrrhetinic acid (18ß-GA), has many antitumor properties. Whether 18ß-GA can modulate autophagy to inhibit proliferation of the luminal A subtype is still unclear. The proportion of apoptosis caused by 18ß-GA in MCF-7 and T-47D cells was determined using flow cytometry. The autophagy marker, LC3-II conversion, was investigated using Western blotting, and a PremoTM Tandem Autophagy Sensor Kit. We found that the concentration (150-µM) of 18ß-GA caused caspase-dependent apoptosis and LC3-II accumulation or blocked autophagic flux. Moreover, 18ß-GA-mediated apoptosis was improved using rapamycin but reversed by 3-methyladenine (3-MA) addition. The phosphorylation level of Jun-amino-terminal kinase (JNK) was increased significantly in the 18ß-GA treatment and combined incubation using rapamycin. A JNK inhibitor (SP600125) significantly inhibited 18ß-GA-mediated apoptosis, LC3-II accumulation and rescued the numbers of MCF-7 and T-47D colony formation. Especially, 18ß-GA can inhibit xenograft tumor growth in BALB/c nude mice. These data indicate the combination of 18ß-GA with rapamycin or 3-MA can sensitize or decrease MCF-7 and T-47D cells to 18ß-GA-induced apoptosis, respectively. 18ß-GA modulated autophagy is cytotoxic to luminal A subtype breast cancer cells through apoptosis promotion and JNK activation.

Glycyrrhetinic acid ameliorates diosbulbin B-induced hepatotoxicity in mice by modulating metabolic activation of diosbulbin B.

Exposure to diosbulbin B (DBB), the primary component of the herbal medicine Dioscorea bulbifera L. (DB), can cause liver injury in humans and experimental animals. A previous study found DBB-induced hepatotoxicity was initiated by CYP3A4-mediated metabolic activation and subsequent formation of adducts with cellular proteins. The herbal medicine licorice (Glycyrrhiza glabra L.) is frequently combined with DB used in numerous Chinese medicinal formulas in an effort to protect against DB-elicited hepatotoxicity. Importantly, glycyrrhetinic acid (GA), the major bioactive ingredient in licorice, inhibits CYP3A4 activity. The study aimed to investigate the protection of GA against DBB-induced hepatotoxicity and the underlying mechanism. Biochemical and histopathological analysis showed GA alleviated DBB-induced liver injury in a dose-dependent manner. In vitro metabolism assay with mouse liver microsomes (MLMs) indicated that GA decreased the generation of metabolic activation-derived pyrrole-glutathione (GSH) conjugates from DBB. Toxicokinetic studies demonstrated that GA increased maximal serum concentration (Cmax ) and area under the serum-time curve (AUC) of DBB in mice. In addition, GA attenuated hepatic GSH depletion caused by DBB. Further mechanistic studies showed that GA reduced the production of DBB-derived pyrroline-protein adducts in a dose-dependent manner. In conclusion, our findings demonstrated that GA exerted protective effect against DBB-induced hepatotoxicity, mainly correlated with suppressing the metabolic activation of DBB. Therefore, the development of a standardized combination of DBB with GA may protect patients from DBB-induced hepatotoxicity.

Carboxymethyl starch as a solid dispersion carrier to enhance the dissolution and bioavailability of piperine and 18ß-glycyrrhetinic acid.

OBJECTIVE: To investigate the applicability of carboxymethyl starch (CMS) as a carrier to prepare solid dispersions (SDs) of piperine (PIP) and 18ß-glycyrrhetinic acid (ß-GA) (PIP-CMS and ß-GA-CMS SDs) and to explore the influence of drug properties on carrier selection. SIGNIFICANCE: The low oral bioavailability of natural therapeutic molecules, including PIP and ß-GA, severely restricts their pharmaceutical applications. Moreover, CMS, a natural polymer, is rarely reported as a carrier for SDs. METHODS: PIP-CMS and ß-GA-CMS SDs were prepared using the solvent evaporation method. Differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD), Fourier transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM) were used for formulation characterization. Additionally, drug release characteristics were investigated. RESULTS: In vitro dissolution studies showed that the dissolutions of PIP-CMS and ß-GA-CMS SDs were 1.90-2.04 and 1.97-2.22 times higher than pure PIP and ß-GA, respectively, at a drug:polymer ratio of 1:6. DSC, XRPD, FT-IR, and SEM analyses confirmed the formation of SDs in their amorphous states. Significant improvements in Cmax and AUC0-24 h of PIP-CMS and ß-GA-CMS SDs (17.51 ± 8.15 µg/mL and 210.28 ± 117.13 µg·h/mL, respectively) and (32.17 ± 9.45 µg/mL and 165.36 ± 38.75 µg·h/mL, respectively) were observed in the pharmacokinetic study. Compared with weakly acidic ß-GA, loading weakly basic PIP seemed to have a profound effect on stability through intermolecular forces. CONCLUSIONS: Our findings showed CMS could be a promising carrier for SDs, and loading weakly basic drug may be more suitable, especially in binary SDs system.

Discovery of Novel Pentacyclic Triterpene Acid Amide Derivatives as Excellent Antimicrobial Agents Dependent on Generation of Reactive Oxygen Species.

Developing new agricultural bactericides is a feasible strategy for stopping the increase in the resistance of plant pathogenic bacteria. Some pentacyclic triterpene acid derivatives were elaborately designed and synthesized. In particular, compound A22 exhibited the best antimicrobial activity against Xanthomonas oryzae pv. oryzae (Xoo) and Xanthomonas axonopodis pv. citri (Xac) with EC50 values of 3.34 and 3.30 mg L-1, respectively. The antimicrobial mechanism showed that the compound A22 induced excessive production and accumulation of reactive oxygen species (ROS) in Xoo cells, leading to a decrease in superoxide dismutase and catalase enzyme activities and an increase in malondialdehyde content. A22 also produced increases in Xoo cell membrane permeability and eventual cell death. In addition, in vivo experiments showed that A22 at 200 mg L-1 exhibited protective activity against rice bacterial blight (50.44%) and citrus canker disease (84.37%). Therefore, this study provides a paradigm for the agricultural application of pentacyclic triterpene acid.

Synthesis and Antiviral and Antitumor Activities of Novel 18ß-Glycyrrhetinic Acid Derivatives.

A series of novel derivatives of 18ß-glycyrrhetinic acid (GA) were synthesized by introducing aromatic or heterocyclic structures to extend the side chain, thereby enhancing their interaction with amino acid residues in the active pocket of the target protein. These compounds were structurally characterized using 1H NMR, 13C NMR, and HRMS. The compounds were subsequently evaluated for their inhibitory effects on HIV-1 protease and cell viability in the human cancer cell lines K562 and HeLa and the mouse cancer cell line CT26. Towards HIV-1 protease, compounds 28 and 32, which featured the introduction of heterocyclic moieties at the C3 position of GA, exhibited the highest inhibition, with inhibition rates of 76% and 70.5%, respectively, at 1 mg/mL concentration. Further molecular docking suggests that a 3-substituted polar moiety would be likely to enhance the inhibitory activity against HIV-1 protease. As for the anti-proliferative activities of the GA derivatives, incorporation of a thiazole heterocycle at the C3- position in compound 29 significantly enhanced the effect against K562 cells with an IC50 value of 8.86 ± 0.93 µM. The introduction of electron-withdrawing substituents on the C3-substituted phenyl ring augmented the anti-proliferative activity against Hela and CT26 cells. Compound 13 exhibited the highest inhibitory activity against Hela cells with an IC50 value of 9.89 ± 0.86 µM, whereas compound 7 exerted the strongest inhibition against CT26 cells with an IC50 value of 4.54 ± 0.37 µM. These findings suggest that further modification of GA is a promising path for developing potent novel anti-HIV and anticancer therapeutics.

Multicomponent Antibiofilm Lipid Nanoparticles as Novel Platform to Ameliorate Resveratrol Properties: Preliminary Outcomes on Fibroblast Proliferation and Migration.

The well-being of skin and mucous membranes is fundamental for the homeostasis of the body and thus it is imperative to treat any lesion quickly and correctly. In this view, polyphenols might assist and enhance a successful wound healing process by reducing the inflammatory cascade and the production of free radicals. However, they suffer from disadvantageous physico-chemical properties, leading to restricted clinical use. In this work, a complex mixture of PEGylated lipid, Glyceryl monoester, 18-ß-Glycyrrhetinic Acid and Menthol was designed to entrap Resveratrol (RSV) as the active ingredient and further produce lipid nanoparticles (LNPs) by homogenization followed by high-frequency sonication. The nanosystem was properly characterized in terms of particle size (DLS, SEM), zeta potential, drug loading, antioxidant power (DPPH), release behaviour, cytocompatibility, wound healing and antibiofilm properties. The optimized lipid mixture was homogeneous, melted at 57-61 °C and encapsulated amorphous RSV (4.56 ± 0.04% w/w). The RSV-loaded LNPs were almost monodispersed (PDI: 0.267 ± 0.010), with nanometric size (162.86 ± 3.12 nm), scavenger properties and suitable DR% and LE% values (96.82 ± 1.34% and 95.17 ± 0.25%, respectively). The release studies were performed to simulate the wound conditions: 1-octanol to mimic the lipophilic domains of biological tissues (where the First Order kinetic was observed) and citrate buffer pH 5.5 according to the inflammatory wound exudate (where the Korsmeyer-Peppas kinetic was followed). The biological and microbiological evaluations highlighted fibroblast proliferation and migration effects as well as antibiofilm properties at extremely low doses (LNPs: 22 µg/mL, corresponding to RSV 5 µM). Thus, the proposed multicomponent LNPs could represent a valuable RSV delivery platform for wound healing purposes.

Anti-Diabetic Activity of Glycyrrhetinic Acid Derivatives FC-114 and FC-122: Scale-Up, In Silico, In Vitro, and In Vivo Studies.

Type 2 diabetes (T2D) is one of the most common diseases and the 8th leading cause of death worldwide. Individuals with T2D are at risk for several health complications that reduce their life expectancy and quality of life. Although several drugs for treating T2D are currently available, many of them have reported side effects ranging from mild to severe. In this work, we present the synthesis in a gram-scale as well as the in silico and in vitro activity of two semisynthetic glycyrrhetinic acid (GA) derivatives (namely FC-114 and FC-122) against Protein Tyrosine Phosphatase 1B (PTP1B) and α-glucosidase enzymes. Furthermore, the in vitro cytotoxicity assay on Human Foreskin fibroblast and the in vivo acute oral toxicity was also conducted. The anti-diabetic activity was determined in streptozotocin-induced diabetic rats after oral administration with FC-114 or FC-122. Results showed that both GA derivatives have potent PTP1B inhibitory activity being FC-122, a dual PTP1B/α-glucosidase inhibitor that could increase insulin sensitivity and reduce intestinal glucose absorption. Molecular docking, molecular dynamics, and enzymatic kinetics studies revealed the inhibition mechanism of FC-122 against α-glucosidase. Both GA derivatives were safe and showed better anti-diabetic activity in vivo than the reference drug acarbose. Moreover, FC-114 improves insulin levels while decreasing LDL and total cholesterol levels without decreasing HDL cholesterol.

Evaluation of the Anticancer Activity and Mechanism Studies of Glycyrrhetic Acid Derivatives toward HeLa Cells.

In this paper, a series of glycyrrhetic acid derivatives 3a-3f were synthesized via the esterification reaction. The cytotoxicity of these compounds against five tumor cells (SGC-7901, BEL-7402, A549, HeLa and B16) and normal LO2 cells was investigated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. The results showed that compound 3a exhibited high antiproliferative activity against HeLa cells (IC50 = 11.4 ± 0.2 µM). The anticancer activity was studied through apoptosis, cloning, and scratching; the levels of the intracellular ROS, GSH, and Ca2+; and the change in the mitochondrial membrane potential, cell cycle arrest and RNA sequencing. Furthermore, the effects of compound 3a on gene expression levels and metabolic pathways in HeLa cells were investigated via transcriptomics. The experimental results showed that this compound can block the cell cycle in the S phase and inhibit cell migration by downregulating Focal adhesion kinase (FAK) expression. Moreover, the compound can reduce the intracellular glutathione (GSH) content, increase the Ca2+ level and the intracellular ROS content, and induce a decrease in the mitochondrial membrane potential, further leading to cell death. In addition, it was also found that the mechanism of compounds inducing apoptosis was related to the regulation of the expression of mitochondria-related proteins B-cell lymphoma-2 (Bcl-2), Bcl-2-Associated X (Bax), and the activation of the caspase proteins. Taken together, this work provides a help for the development of glycyrrhetinic acid compounds as potential anticancer molecules.

Anti-Photoaging Effects of Nanocomposites of Amphiphilic Chitosan/18ß-Glycyrrhetinic Acid.

Improving the transdermal absorption of weakly soluble drugs for topical use can help to prevent and treat skin photoaging. Nanocrystals of 18ß-glycyrrhetinic acid (i.e., NGAs) prepared by high-pressure homogenization and amphiphilic chitosan (ACS) were used to form ANGA composites by electrostatic adsorption, and the optimal ratio of NGA to ACS was 10:1. Dynamic light scattering analysis and zeta potential analysis were used to evaluate the nanocomposites' suspension, and the results showed that mean particle size was 318.8 ± 5.4 nm and the zeta potential was 30.88 ± 1.4 mV after autoclaving (121 °C, 30 min). The results of CCK-8 showed that the half-maximal inhibitory concentration (IC50) of ANGAs (71.9 µg/mL) was higher than that of NGAs (51.6 µg/mL), indicating that the cytotoxicity of ANGAs was weaker than that of NGAs at 24 h. After the composite had been prepared as a hydrogel, the vertical diffusion (Franz) cells were used to investigate skin permeability in vitro, and it was shown that the cumulative permeability of the ANGA hydrogel increased from 56.5 ± 1.4% to 75.3 ± 1.8%. The efficacy of the ANGA hydrogel against skin photoaging was studied by constructing a photoaging animal model under ultraviolet (UV) irradiation and staining. The ANGA hydrogel improved the photoaging characteristics of UV-induced mouse skin significantly, improved structural changes (e.g., breakage and clumping of collagen and elastic fibers in the dermis) significantly, and improved skin elasticity, while it inhibited the abnormal expression of matrix metalloproteinase (MMP)-1 and MMP-3 significantly, thereby reducing the damage caused by UV irradiation to the collagen-fiber structure. These results indicated that the NGAs could enhance the local penetration of GA into the skin and significantly improve the photoaging of mouse skin. The ANGA hydrogel could be used to counteract skin photoaging.

Synthesis of Chitosan Oligosaccharide-Loaded Glycyrrhetinic Acid Functionalized Mesoporous Silica Nanoparticles and In Vitro Verification of the Treatment of APAP-Induced Liver Injury.

OBJECTIVE: the study was to find a suitable treatment for acute drug-induced liver injury. The use of nanocarriers can improve the therapeutic effect of natural drugs by targeting hepatocytes and higher loads. METHODS: firstly, uniformly dispersed three-dimensional dendritic mesoporous silica nanospheres (MSNs) were synthesized. Glycyrrhetinic acid (GA) was covalently modified on MSN surfaces through amide bond and then loaded with COSM to form drug-loaded nanoparticles (COSM@MSN-NH2-GA). The constructed drug-loaded nano-delivery system was determined by characterization analysis. Finally, the effect of nano-drug particles on cell viability was evaluated and the cell uptake in vitro was observed. RESULTS: GA was successfully modified to obtain the spherical nano-carrier MSN-NH2-GA (≤200 nm). The neutral surface charge improves its biocompatibility. MSN-NH2-GA has high drug loading (28.36% ± 1.00) because of its suitable specific surface area and pore volume. In vitro cell experiments showed that COSM@MSN-NH2-GA significantly enhanced the uptake of liver cells (LO2) and decreased the AST and ALT indexes. CONCLUSION: this study demonstrated for the first time that formulation and delivery schemes using natural drug COSM and nanocarrier MSN have a protective effect on APAP-induced hepatocyte injury. This result provides a potential nano-delivery scheme for the targeted therapy of acute drug-induced liver injury.