Glycyrrhizin and Mannitol Nasal Therapy: Cytological and Clinical Outcomes in Chronic Rhinitis.

Introduction Chronic rhinitis (CR) represents a widespread inflammation with a high incidence in the general population. Although it is generally considered a benign condition, CR has a relevant impact on quality of life and requires a specific treatment approach. Objective The aim of the present study was to investigate the efficacy of glycyrrhizin and mannitol intranasal treatment on chronic rhinitis using cytological analysis and subjective evaluation of symptoms. Methods A total of 55 patients suffering from chronic rhinitis were enrolled in the present study, 34 with allergic rhinitis (AR) and 21 with nonallergic rhinitis (NAR). The severity of four different nasal symptoms was determined by using a visual analogue scale (VAS). Specimens obtained by nasal scraping were collected for cytological analysis. Data were acquired before and after a 30-day treatment with glycyrrhizin and mannitol nasal spray. Statistical analyses were performed. Results The VAS scores for all four nasal symptoms considered in the present study, as well as for neutrophil cells, reduced significantly after therapy in both allergic and nonallergic patients. The number of eosinophils was not significantly lower in nonallergic patients. Conclusion A 30-day topical treatment with glycyrrhizin and mannitol may improve nasal symptoms and reduce inflammatory cells in the nasal mucosa in patients with chronic rhinitis without significant contraindications. Further studies could support our results and would better clarify all the aspects of this treatment.

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.

Glycyrrhizin and Mannitol Nasal Therapy: Cytological and Clinical Outcomes in Chronic Rhinitis

Abstract Introduction Chronic rhinitis (CR) represents a widespread inflammation with a high incidence in the general population. Although it is generally considered a benign condition, CR has a relevant impact on quality of life and requires a specific treatment approach. Objective The aim of the present study was to investigate the efficacy of glycyrrhizin and mannitol intranasal treatment on chronic rhinitis using cytological analysis and subjective evaluation of symptoms. Methods A total of 55 patients suffering from chronic rhinitis were enrolled in the present study, 34 with allergic rhinitis (AR) and 21 with nonallergic rhinitis (NAR). The severity of four different nasal symptoms was determined by using a visual analogue scale (VAS). Specimens obtained by nasal scraping were collected for cytological analysis. Data were acquired before and after a 30-day treatment with glycyrrhizin and mannitol nasal spray. Statistical analyses were performed. Results The VAS scores for all four nasal symptoms considered in the present study, as well as for neutrophil cells, reduced significantly after therapy in both allergic and nonallergic patients. The number of eosinophils was not significantly lower in nonallergic patients. Conclusion A 30-day topical treatment with glycyrrhizin and mannitol may improve nasal symptoms and reduce inflammatory cells in the nasal mucosa in patients with chronic rhinitis without significant contraindications. Further studies could support our results and would better clarify all the aspects of this treatment.

The Anti-Inflammatory Properties of Licorice (Glycyrrhiza glabra)-Derived Compounds in Intestinal Disorders.

Intestinal diseases, such as inflammatory bowel diseases (IBDs) and colorectal cancer (CRC), are a significant source of morbidity and mortality worldwide. Epidemiological data have shown that IBD patients are at an increased risk for the development of CRC. IBD-associated cancer develops against a background of chronic inflammation and oxidative stress, and their products contribute to cancer development and progression. Therefore, the discovery of novel drugs for the treatment of intestinal diseases is urgently needed. Licorice (Glycyrrhiza glabra) has been largely used for thousands of years in traditional Chinese medicine. Licorice and its derived compounds possess antiallergic, antibacterial, antiviral, anti-inflammatory, and antitumor effects. These pharmacological properties aid in the treatment of inflammatory diseases. In this review, we discuss the pharmacological potential of bioactive compounds derived from Licorice and addresses their anti-inflammatory and antioxidant properties. We also discuss how the mechanisms of action in these compounds can influence their effectiveness and lead to therapeutic effects on intestinal disorders.

18ß-glycyrrhetinic acid attenuates global cerebral ischemia/reperfusion-induced cardiac damage in C57BL/J6 mice

Abstract The aim of the present study is to investigate the cardioprotective effects of 18ß-glycyrrhetinic acid (18ß -GA) against oxidative and histological damage caused by global cerebral ischemia/ reperfusion (I/R) in C57BL/J6 mice. All male mice (n:40) were randomly divided into four groups: (1) sham-operated (Sham), (2) I/R, (3) 18ß-GA, and (4) 18ß -GA+I/R. Ischemia was not applied to the sham and 18ß-GA groups. In the I/R group, the bilateral carotid arteries were clipped for 15 min to induce ischemia, and the mice were treated with the vehicle for 10 days. In the 18ß-GA group, the mice were given 18ß-GA (100 mg/kg) for 10 days following a median incision without carotid occlusion. In the 18ß-GA+I/R group, the ischemic procedure performed to the I/R model was applied to the animals and afterwards they were intraperitoneally (i.p.) treated with 18ß-GA (100 mg/kg) for 10 days. It was found that global cerebral I/R increased TBARS levels and decreased antioxidant parameters. The 18ß-GA treatment decreased the level of TBARS and increased GSH, GPx, CAT, SOD activities. Also, the control group cardiac tissue samples were observed to have a normal histological appearance with the Hematoxylin-Eosin staining method. Histopathological damage was observed in the heart tissue samples belonging to the I/R group. The 18ß-GA treatment ameliorates oxidative and histological injury in the heart tissue after global ischemia reperfusion, and may be a beneficial alternative treatment

Glycyrrhizic Acid and Its Hydrolyzed Metabolite 18ß-Glycyrrhetinic Acid as Specific Ligands for Targeting Nanosystems in the Treatment of Liver Cancer.

Glycyrrhizic acid and its hydrolyzed metabolite 18ß-glycyrrhetinic acid, obtained from the plant Glycyrrhiza glabra, have numerous pharmacological activities, such as anti-inflammatory, anti-ulcerative, antiallergic, immunomodulatory, antiviral, antitumor, hepatoprotective, and antioxidant effects, and others. In addition to the pharmacological activities, in the 1980s, an interaction and uptake of these molecules by the liver was verified, which was later confirmed by other studies through the discovery of specific receptors in the hepatocytes. The presence of these specific receptors in the liver led to vectorization and delivery of drugs, by the introduction of glycyrrhizic acid or glycyrrhetinic acid on the surface of nanosystems, for the treatment of liver diseases. This review describes experimental evidence of vectorization by conjugating glycyrrhizic acid or glycyrrhetinic acid to nanosystems and delivery of antitumor drugs for the treatment of liver cancer and also describes the techniques used to perform this conjugation. We have shown that due to the existence of specific receptors for these molecules, in addition to the targeting of nanosystems to hepatocytes, nanosystems having glycyrrhizic acid or glycyrrhetinic acid on their surface had the same therapeutic effect in a significantly lower dose compared to the free drug and unconjugated nanosystems, with consequent reduction of side effects and toxicity.

Indole- and Pyrazole-Glycyrrhetinic Acid Derivatives as PTP1B Inhibitors: Synthesis, In Vitro and In Silico Studies.

Regulating insulin and leptin levels using a protein tyrosine phosphatase 1B (PTP1B) inhibitor is an attractive strategy to treat diabetes and obesity. Glycyrrhetinic acid (GA), a triterpenoid, may weakly inhibit this enzyme. Nonetheless, semisynthetic derivatives of GA have not been developed as PTP1B inhibitors to date. Herein we describe the synthesis and evaluation of two series of indole- and N-phenylpyrazole-GA derivatives (4a-f and 5a-f). We measured their inhibitory activity and enzyme kinetics against PTP1B using p-nitrophenylphosphate (pNPP) assay. GA derivatives bearing substituted indoles or N-phenylpyrazoles fused to their A-ring showed a 50% inhibitory concentration for PTP1B in a range from 2.5 to 10.1 µM. The trifluoromethyl derivative of indole-GA (4f) exhibited non-competitive inhibition of PTP1B as well as higher potency (IC50 = 2.5 µM) than that of positive controls ursolic acid (IC50 = 5.6 µM), claramine (IC50 = 13.7 µM) and suramin (IC50 = 4.1 µM). Finally, docking and molecular dynamics simulations provided the theoretical basis for the favorable activity of the designed compounds.

Chemoenzymatic synthesis of new derivatives of glycyrrhetinic acid with antiviral activity. Molecular docking study.

We present an efficient approach to the synthesis of a series of glycyrrhetinic acid derivatives. Six derivatives, five of them new compounds, were obtained through chemoenzymatic reactions in very good to excellent yield. In order to find the optimal reaction conditions, the influence of various parameters such as enzyme source, nucleophile:substrate ratio, enzyme:substrate ratio, solvent and temperature was studied. The excellent results obtained by lipase catalysis made the procedure very efficient considering their advantages such as mild reaction conditions and low environmental impact. Moreover, in order to explain the reactivity of glycyrrhetinic acid and the acetylated derivative to different nucleophiles in the enzymatic reactions, molecular docking studies were carried out. In addition, one of the synthesized compounds exhibited remarkable antiviral activity against TK + and TK- strains of Herpes simplex virus type 1 (HSV-1), sensitive and resistant to acyclovir (ACV) treatment.

Improving the thrombin inhibitory activity of glycyrrhizin, a triterpenic saponin, through a molecular simplification of the carbohydrate moiety.

Glycyrrhizin, a saponin, and its aglycone glycyrrhetinic acid are natural products found in the Liquorice (Glycyrrhiza glabra L.) root extract. This saponin is known for its in vitro and in vivo thrombin inhibitory activity. The design and synthesis of five glycyrrhizin derivatives were carried out to improve the natural product activity. Compound 3b, a phthalic ester derivative of glycyrrhizin, presented a more pronounced thrombin inhibition (IC50  = 114.4 ± 1.3 µm) than the saponin (IC50  = 235.7 ± 1.4 µm). Molecular docking simulations performed to investigate the molecular interaction between compound 3b and the enzyme indicate that this product is, as previously determined for glycyrrhizin, an allosteric thrombin inhibitor.