18β-Glycyrrhetinic acid inhibits the apoptosis of cells infected with rotavirus SA11 via the Fas/FasL pathway

CONTEXT

18β-Glycyrrhetinic acid (18β-GA), a pentacyclic triterpenoid saponin metabolite of glycyrrhizin, exhibits several biological activities.

OBJECTIVE

We investigated the effects of 18β-GA on MA104 cells infected with rotavirus (RV) and its potential mechanism of action.

MATERIALS AND METHODS

Cell Counting Kit-8 was used to assess tissue culture infective dose 50 (TCID₅₀) and 50% cellular cytotoxicity (CC₅₀) concentration. MA104 cells infected with RV SA11 were treated with 18β-GA (1, 2, 4, and 8 μg/mL, respectively). Cytopathic effects were observed. The virus inhibition rate, concentration for 50% of maximal effect (EC₅₀), and selection index (SI) were calculated. Cell cycle, cell apoptosis, and mRNA and protein expression related to the Fas/FasL pathway were detected.

RESULTS

TCID₅₀ of RV SA11 was 10^-4.47/100 µL; the CC₅₀ of 18β-GA on MA104 cells was 86.92 µg/mL. 18β-GA showed significant antiviral activity; EC₅₀ was 3.14 μg/mL, and SI was 27.68. The ratio of MA104 cells infected with RV SA11 in the G0/G1 phase and the G2/M phase decreased and increased, respectively, after 18β-GA treatment. 18β-GA significantly induced apoptosis in the infected cells. Furthermore, after 18β-GA treatment, the mRNA and protein expression levels of Fas, FasL, caspase 3, and Bcl-2 decreased, whereas the expression levels of Bax increased.

DISCUSSION AND CONCLUSIONS

The study demonstrates that 18β-GA may be a promising candidate for the treatment of RV SA11 infection and provides theoretical support for the clinical development of glycyrrhizic acid compounds for the treatment of RV infection.

Protection function of 18β-glycyrrhetinic acid on rats with high-altitude pulmonary hypertension based on 1H NMR metabonomics technology

18β-Glycyrrhetinic acid (GA) is the triterpenoid aglycone component of glycyrrhizic acid, a natural product of traditional Chinese medicine, and has been proven to possess a variety of pharmacological effects. The protection function and the mechanism of GA on rats with high-altitude pulmonary hypertension (HAPH) are studied using proton nuclear magnetic resonance (1H NMR) metabonomics technology and biochemical analysis. An HAPH model is established, and 60 male rats are randomly divided into the following groups: Control(normal saline, 0.4 mL/100 g), model (normal saline, 0.4 mL/100 g), Nifedipine (nifedipine, 2.7 mg/kg), and high-, medium-, and low-dose GA groups (100, 50, and 25 mg/kg GA designated as GA.H, GA.M, and GA.L, respectively). Serum biochemical indicators of rats in each group are measured, and pathological changes in the pulmonary artery are observed. 1H NMR metabonomics technology is used for serum analysis. Results show that GA can significantly reduce pulmonary arterial pressure and malondialdehyde levels and increase the glutathione peroxidase and superoxide dismutase activities in HAPH rats. Pathological results show that GA can alleviate pulmonary artery injuries of HAPH rats. Metabolomics analytical findings show that GA can alleviate the metabolic disorder of HAPH rats through anti-oxidation and anti-inflammatory effects, improve their bodies' ability to resist hypoxia, and restore various metabolic pathways (energy metabolism, amino acid metabolism, and lipid metabolism). GA has potential therapeutic effects on HAPH rats, but its target needs to be further studied.

Glycyrrhetinic acid remodels the tumor microenvironment and synergizes with doxorubicin for breast cancer treatment in a murine model

We aimed to combine glycyrrhetinic acid with doxorubicin to prepare, characterize and evaluate a drug delivery nano-system with REDOX sensitivity for the treatment of breast cancer. M-DOX-GA NPs prepared by nano sedimentation were spherical, with a particle size of 181 nm. And the maximum encapsulation efficiency and drug loading in M-DOX-GA NPs were 89.28% and 18.22%, respectively. Cytotoxicity and cellular uptake experiments of nanoparticles to KC cells, Cal-27 cells and 4T1 cells were studied by the CCK-8 method. The result indicated that M-DOX-GA NPs could accurately release the drug into the tumor cells, thus achieving the targeted release of the drug. Comparing the survival rate of the above three cells, it was found that M-DOX-GA NPs had a good tumor selectivity and had a more significant therapeutic effect on breast cancer. A 4T1-bearing mouse model was established, and the tumor inhibition rate was 77.37% after injection of nanoparticle solution for 14 d. Normal tissue H&E stained sections and TUNEL assay were verified M-DOX-GA NPs have excellent tumor suppressive effect, and can efficiently reduce the toxic side effects on normal organisms, and effectively avoided 4T1 cells metastasis. Immunofluorescence detection and Western-blot analysis figured a decline in both CUGBP1 and α-SMA, which verifying the TME remodeling induced by glycyrrhetinic acid. Collectively, the combination of doxorubicin and glycyrrhetinic acid is an effective and safe strategy for remodeling fibrotic TME by improving the therapeutic outcome for breast cancer.

Synergistic breast cancer suppression efficacy of doxorubicin by combination with glycyrrhetinic acid as an angiogenesis inhibitor

BACKGROUND

Therapeutic regimens of breast cancer treatment are increasingly inclined to adopt combination strategy based on the broad spectrum antitumor effect of doxorubicin (Dox). Currently, combination therapy comprises of conventional anti-cancer drugs and angiogenesis inhibitors have been corroborated as an effective approach in cancer treatment.

PURPOSE

We explored the ability of a natural anti-angiogenic compound glycyrrhetinic acid (GA), derived from an edible-medicinal herb licorice, to enhance the breast cancer suppression effect of Dox.

STUDY DESIGN

The drug ratio of GA and Dox with synergistic anticancer effect against MCF-7 cells was optimized by combination index (CI) value in vitro, followed by evaluation of the improved anticancer effects and reduced side-effects of this combination in vitro and in vivo.

METHODS

Cell viability was measured by MTT assay. Analyses of mitochondrial membrane potential and cell apoptosis on MCF-7 cells were performed by JC-1 dye and Annexin V-FITC/PI assays. The cellular accumulation of Dox when combined with GA was evaluated. Levels of apoptosis-related proteins in MCF-7 cells were measured by Western blot analysis. Synergistic anti-angiogenic effects on HUVECs were evaluated. A breast cancer mouse model was established to investigate the anti-tumor effects in vivo.

RESULTS

Based on the optimization by CI value, Dox and GA at 1:20 molar ratio was chosen as the optimal combination drug ratio that exhibited synergistic effect against MCF-7 breast cancer cells. In addition, the combination of GA and Dox exhibited significantly enhanced cytotoxicity, apoptosis, and loss of mitochondrial membrane potential via the upregulation of a mitochondrial-dependent apoptosis pathway against MCF-7 cells. Interestingly, the addition of GA increased the intracellular accumulation of Dox in MCF-7 cells. Moreover, VEGF-induced HUVECs proliferation, migration, and tube formation were strongly inhibited by Dox when used with GA via the significant down-regulation of VEGFR2-mediated pathway, indicating that the combination of Dox and GA could exhibit ideal synergistic anti-angiogenesis effect. Expectedly, the enhanced anti-tumor efficacy of Dox and reduced Dox-induced cardiotoxicity when used in combination with GA were evident in a mouse breast tumor model.

CONCLUSIONS

These findings support that the combination of Dox with GA is a novel and promising therapeutic strategy for the treatment of breast cancer.

Enhanced targeted delivery of adenine to hepatocellular carcinoma using glycyrrhetinic acid-functionalized nanoparticles in vivo and in vitro

Hepatocellular carcinoma (HCC), a common malignancy in China and globally, is primarily treated through surgical resection and liver transplantation, with chemotherapy as a significant synergistic option. Adenine (Ade), a nucleobase, exhibits antitumor effects by blocking human hepatic carcinoma cells in S phase and inhibiting tumor cell proliferation. However, its use is limited owing to its low solubility, poor targeting ability, and nephrotoxicity. Therefore, liver-targeting drug delivery systems have attracted considerable attention for the treatment of HCC. In this study, we explored the liver-targeting efficacy and antitumor effect of adenine-loaded glycyrrhetinic acid-modified hyaluronic acid (Ade/GA-HA) nanoparticles in vitro and in vivo. The GA-HA nanoparticles possessed obvious targeting specificity toward liver cancer cells, which was mainly achieved by the specific binding of the GA ligand to the GA receptor that was highly expressed on the liver cell membrane. In vitro and in vivo results showed that Ade/GA-HA nanoparticles could inhibit liver cancer cell proliferation and migration, promote apoptosis, and significantly inhibit the growth of tumor tissues. Altogether, this study is the first to successfully demonstrate that the targeting activity and antitumor effect of Ade against HCC are enhanced by using GA-HA nanoparticles in vitro and in vivo.

Evaluation of the Percutaneous Absorption of Drug Molecules in Zebrafish

In recent decades, zebrafish (Danio rerio) has become a widely used vertebrate animal model for studying development and human diseases. However, studies on skin medication using zebrafish are rare. Here, we developed a novel protocol for percutaneous absorption of molecules via the zebrafish tail skin, by applying a liquid solution directly, or using a filter paper imbibed with a chemical solution (coating). Human skin is capable of absorbing felbinac and loxoprofen sodium hydrate (LSH), but not glycyrrhetinic acid (GA) and terbinafine hydrochloride (TH). To evaluate the possibility and the quality of transdermal absorption in zebrafish, we transdermally administered these four drugs to zebrafish. Pharmacokinetics showed that felbinac was present in the blood of zebrafish subjected to all administration methods. Felbinac blood concentrations peaked at 2 h and disappeared 7 h after administration. GA was not detected following transdermal administrations, but was following exposure. LSH was not found in the circulatory system after transdermal administration, but TH was. A dose-response correlation was observed for felbinac blood concentration. These findings suggest that zebrafish are capable of absorbing drug molecules through their skin. However, the present data cannot demonstrate that zebrafish is a practical model to predict human skin absorption. Further systemic studies are needed to observe the correlations in percutaneous absorption between humans and zebrafish.

Controlled release of 18-β-glycyrrhetic acid by nanodelivery systems increases cytotoxicity on oral carcinoma cell line

The topical treatment for oral mucosal diseases is often based on products optimized for dermatologic applications; consequently, a lower therapeutic effect may be present. 18-β-glycyrrhetic acid (GA) is extracted from Glycirrhiza glabra. The first aim of this study was to test the cytotoxicity of GA on PE/CA-PJ15 cells. The second aim was to propose and test two different delivery systems, i.e. nanoparticles and fibers, to guarantee a controlled release of GA in vitro. We used chitosan and poly(lactic-co-glycolic) acid based nanoparticles and polylactic acid fibers. We tested both delivery systems in vitro on PE/CA-PJ15 cells and on normal human gingival fibroblasts (HGFs). The morphology of GA-loaded nanoparticles (GA-NPs) and fibers (GA-FBs) was investigated by electron microscopy and dynamic light scattering; GA release kinetics was studied spectrophotometrically. MTT test was used to assess GA cytotoxicity on both cancer and normal cells. Cells were exposed to different concentrations of GA (20-500 μmol l^-1) administered as free GA (GA-f), and to GA-NPs or GA-FBs. ROS production was evaluated using dichlorodihydrofluorescein as a fluorescent probe. Regarding the cytotoxic effect of GA on PE/CA-PJ15 cells, the lowest TC₅₀ value was 200 μmol l^-1 when GA was added as GA-NPs. No cytotoxic effects were observed when GA was administered to HGFs. N-acetyl Cysteine reduced mortality induced by GA-f in PE/CA-PJ15 cells. The specific effect of GA on PE/CA-PJ15 cells is mainly due to the different sensitivity of cancer cells to ROS over-production; GA-NPs and GA-FBs formulations increase, in vitro, this toxic effect on oral cancer cells.

18β-Glycyrrhetinic acid mitigates radiation-induced skin damage via NADPH oxidase/ROS/p38MAPK and NF-κB pathways

Radiation-induced inflammation plays an important role in radiation-induced tissue injury. 18β-glycyrrhetinic acid (18β-GA) has shown an anti-inflammatory activity. This study aimed to assess the activity of 18β-GA against radiation-induced skin damage, and explore the underlying mechanisms. In vitro assay revealed 18β-GA treatment decreased the production of IL-1β, IL-6, PGE2 and decreased p38MAPK phosphorylation, DNA-binding activity of AP-1, and NF-κB activation in irradiated RAW264.7 macrophages. Additionally, 18β-GA suppressed NF-κB activation by inhibiting NF-κB/p65 and IκB-α phosphorylation and alleviated ROS overproduction in irradiated RAW264.7 macrophages. In vivo assay showed 18β-GA alleviated severity of radiation-induced skin damage, reduced inflammatory cell infiltration and TNF-α, IL-1β and IL-6 levels in cutaneous tissues. Our findings demonstrate that 18β-GA exhibits anti-inflammatory actions against radiation-induced skin damage probably by inhibiting NADPH oxidase activity, ROS production, activation of p38MAPK and NF-κB signaling, and the DNA binding activities of NF-κB and AP-1, consequently suppressing pro-inflammatory cytokine production.

Enhanced oral bioavailability of glycyrrhetinic acid via nanocrystal formulation

The purpose of this study was to prepare solid nanocrystals of glycyrrhetinic acid (GA) for improved oral bioavailability. The anti-solvent precipitation-ultrasonication method followed by freeze-drying was adopted for the preparation of GA nanocrystals. The physicochemical properties, drug dissolution and pharmacokinetic of the obtained nanocrystals were investigated. GA nanocrystals showed a mean particle size of 220 nm and shaped like short rods. The analysis results from differential scanning calorimetry and X-ray powder diffraction indicated that GA remained in crystalline state despite a huge size reduction. The equilibrium solubility and dissolution rate of GA nanocrystal were significantly improved in comparison with those of the coarse GA or the physical mixture. The bioavailability of GA nanocrystals in rats was 4.3-fold higher than that of the coarse GA after oral administration. With its rapid dissolution and absorption performance, the solid nanocrystal might be a more preferable formulation for oral administration of poorly soluble GA.

Simultaneous Determination of Twenty-Five Compounds in Rat Plasma Using Ultra-High Performance Liquid Chromatography-Polarity Switching Tandem Mass Spectrometry and Its Application to a Pharmacokinetic Study

An attempt was made to characterize the pharmacokinetic profiles of Qishen Keli (QSKL) that has been widely proved to be effective in clinical practice. A method using ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) for the simultaneous determination of 25 analytes in rat plasma was developed and validated. Satisfactory chromatographic separation was achieved on an ACQUITY UPLC HSS T3 column with gradient elution using mobile phase consisting of 0.02% aqueous formic acid (A) and acetonitrile fortified with 0.02% formic acid (B), and analyte detection was carried out using polarity-switching multiple reaction monitoring mode. Method validation assays in terms of selectivity, linearity, inter- and intra-day variations, matrix effect, and recovery demonstrated the newly developed method to be specific, sensitive, accurate, and precise. Following the oral administration of QSKL at a single dose, the qualified method was successfully applied for pharmacokinetic investigations in sham and model rats. Mild differences occurred for the pharmacokinetic patterns of most components between those two groups, whereas significant differences were observed for glycyrrhizic acid and glycyrrhetic acid. The obtained findings could provide meaningful information for the clarification of the effective material basis of QSKL.

Cellular uptake mechanism and clearance kinetics of fluorescence-labeled glycyrrhetinic acid and glycyrrhetinic acid-modified liposome in hepatocellular carcinoma cells

Glycyrrhetinic acid (GA) is a natural pentacyclic triterpene derivative that exerts significant effects in the suppression of liver cancer. The receptors of GA on liver cells and hepatocellular carcinoma (HCC) cells have drawn broad attention. The effects of GA might depend on its transport into and out of cells. However, the question has not been previously addressed despite its obvious and fundamental importance. In this paper, GA and GA-modified liposome (GA-Lip) were labeled with fluorescein isothiocyanate (FITC) or coumarin 6 (Cou6) using chemical or pharmaceutical techniques. The transport courses of FITC-GA and GA-Cou6-Lip were studied in HepG2 cells in vitro. We found that the fluorescence labeled GA and GA-Lip uptake and clearance were time-dependent. FITC-GA uptake involved passive diffusion and active transport, and the receptors were in the cytomembrane proteins. GA-Cou6-Lip uptake was mediated by caveolae-dependent endocytosis. In addition, FITC-GA and GA-Cou6-Lip clearance of the HCC cells fitted exponential decay and second-order processes, respectively. These findings provide new insights into the anti-HCC actions of GA.

CF3DODA-Me induces apoptosis, degrades Sp1, and blocks the transformation phase of the blebbishield emergency program

Cancer stem cells are capable of undergoing cellular transformation after commencement of apoptosis through the blebbishield emergency program in a VEGF-VEGFR2-dependent manner. Development of therapeutics targeting the blebbishield emergency program would thus be important in cancer therapy. Specificity protein 1 (Sp1) orchestrates the transcription of both VEGF and VEGFR2; hence, Sp1 could act as a therapeutic target. Here, we demonstrate that CF3DODA-Me induced apoptosis, degraded Sp1, inhibited the expression of multiple drivers of the blebbishield emergency program such as VEGFR2, p70S6K, and N-Myc through activation of caspase-3, inhibited reactive oxygen species; and inhibited K-Ras activation to abolish transformation from blebbishields as well as transformation in soft agar. These findings confirm CF3DODA-Me as a potential therapeutic candidate that can induce apoptosis and block transformation from blebbishields.

Liquorice and soy sauce, a life-saving concoction in a patient with Addison's disease

Addison's disease is a relatively common disorder to endocrinologists, but is rare and potentially fatal when presenting acutely. Treatment now involves replacement of glucocorticoids and mineralocorticoids with synthetic compounds, although historically patients took common salt and plant-based preparations. We describe the case of a 42-year-old woman who self-treated undiagnosed Addison's disease for several years with soy sauce and liquorice sticks. She presented with a four-week history of decreased energy, malaise and postural dizziness. Our patient described an unusual diet of liquorice sticks and soy sauce, consuming around 46 g of salt per week. There was a family history of Type 1 diabetes mellitus. Physical examination was unremarkable, although subsequent investigation confirmed Addison's disease. Liquorice provided glycyrrhizic acid and glycyrrhetinic acid, which act on 11-beta hydroxysteroid dehydrogenase enzymes. In this case, the net effect was potentiation of glucocorticoid action on renal mineralocorticoid receptors in the context of failing adrenocortical steroid production. The case highlights the importance of taking a dietary history to aid diagnosis.

Pharmacokinetics and pharmacodynamics of glycyrrhetinic acid with Paeoniflorin after transdermal administration in dysmenorrhea model mice

BACKGROUND

Glycyrrhetinic acid (GA) and paeoniflorin (PF) are the main active ingredients in Chinese peony- Liquorice Decoction, a widely used Traditional Chinese Medicine.

HYPOTHESIS/PURPOSE

The aim of this work was to investigate the combinatory analgesic effect of GA and PF after percutaneous administration and to define their pharmacokinetic/pharmacodynamic (PK/PD) characteristics.

STUDY DESIGN AND METHODS

GA and PF were produced to transdermal patches based on previous research, and the permeation parameters of GA and PF in the patches were investigated with in vitro experiments. Dysmenorrhea model mice were then produced to compare the analgesic effects of the patches with different proportions of GA-PF. In the in vivo assessment, the number of writhes exhibited by the dysmenorrhea mice was recorded at designated time points, and skin, muscle under skin and plasma samples were collected, for assessments of drug distribution, pharmacokinetics parameters and PK/PD characteristics.

RESULTS AND CONCLUSION

In dysmenorrhea mice, GA-PF and meloxicam (the positive control drug) could relieve pain to equal degrees. Specifically, a single dose of the optimized patches (10%GA-10%PF, wt) exerted a steady analgesic effect for 48h in dysmenorrhea mice, but this effect lagged behind the changes in the plasma concentration. Evaluation with the Bliss Independence criterion revealed that the two ingredients displayed a synergistic effect. Then the PK/PD relationship of GA in this compound preparation was defined with this synergistic effect. The preparation might be suitable for topical spasmolysis and anti-inflammatory therapy.

The protection of glycyrrhetinic acid (GA) towards acetaminophen (APAP)-induced toxicity partially through fatty acids metabolic pathway

BACKGROUND

Acetaminophen (APAP)-induced liver toxicity remains the key factor limiting the clinical application of APAP, and herbs are the important sources for isolation of compounds preventing APAP-induced toxicity.

AIMS

To investigate the protection mechanism of glycyrrhetinic acid towards APAP-induced liver damage using metabolomics method.

METHODS

APAP-induced liver toxicity model was made through intraperitoneal injection (i.p.) of APAP (400 mg/kg). Glycyrrhetinic acid was dissolved in corn oil, and intraperitoneal injection (i.p.) of glycyrrhetinic acid (500 mg/kg body weight) was performed for 20 days before the injection of APAP. UPLC-ESI-QTOF MS was employed to analyze the metabolomic profile of serum samples.

RESULTS

The pre-treatment of glycyrrhetinic acid significantly protected APAP-induced toxicity, indicated by the histology of liver, the activity of ALT and AST. Metabolomics showed that the level of palmtioylcarnitine and oleoylcarnitine significantly increased in serum of APAP-treated mice, and the pre-treatment with GA can prevent this elevation of these two fatty acid-carnitines.

CONCLUSION

Reversing the metabolism pathway of fatty acid is an important mechanism for the protection of glycyrrhetinic acid towards acetaminophen-induced liver toxicity.

The influence of compatibility of processed radix Aconiti Kusnezoffii on the pharmacokinetic of four components in Glycyrrhiza uralensis Fisch

ETHNOPHARMACOLOGICAL RELEVANCE

Glycyrrhiza uralensis Fisch. and processed radix Aconiti kusnezoffii are the main components in many Chinese traditional patent medicines with the ratio of 1:1, which are used for treatment of rheumatoid arthritis, heart failure and so on. Glycyrrhizic acid, glycyrrhetic acid, liquiritigenin and isoliquiritigenin are the essential bioactive triterpenes and flavones in the extract of G. uralensis, which were analysis by a simple but accurate method.

MATERIALS AND METHODS

In the present study, a specific HPLC method was developed and validated for simultaneous determination of pharmacokinetic parameters of glycyrrhizic acid, glycyrrhetic acid, liquiritigenin and isoliquiritigenin in G. uralensis after oral administration of single herb extract and a combination of two herbs extracts respectively.

RESULTS

The calibration curves of the four components had good linearity higher than 0.9991 in the measured range. The intra-day and inter-day precisions (RSD) at different levels were both within 9.73%, and the accuracies (RE) were in the range of -7.9-8.0%. Compared with pharmacokinetic parameters of G. uralensis administered orally, values of AUC and Cmax of liquiritigenin and isoliquiritigenin decreased significantly (p<0.05), plasma concentrations of glycyrrhizic acid rose slightly and bimodal phenomenon of concentration-time of isoliquiritigenin and glycyrrhetinic acid disappeared after combined administration.

DISCUSSION AND CONCLUSIONS

Some components in the extract of processed radix A. kusnezoffii showed different effects on the pharmacokinetics of the four ingredients in G. uralensis.

Effect of the liquorice root derivatives on salt and water balance in a teleost fish, rainbow trout (Oncorhynchus mykiss)

The effect of liquorice root derivatives (LRDs) glycyrrhizic acid (GL) and glycyrrhetinic acid (18βGA) on salt and water balance and end points of gill ion transport in a freshwater teleost, (rainbow trout) was examined after feeding fish diets containing GL or 18βGA (0, 5, 50 or 500 µg/g diet) for a two week period. Serum cortisol levels and gill 11β-hydroxysteroid dehydrogenase type 2 mRNA abundance decreased in fish fed GL but increased (at select doses) in fish fed 18βGA. At higher doses of GL, gill Na(+)-K(+)-ATPase and H(+)-ATPase activity increased, while cystic fibrosis transmembrane conductance regulator type II mRNA abundance significantly decreased at the lowest dose of GL. End points of gill transcellular ion transport were not significantly altered in fish fed 18βGA, except for a reduction in Na(+)-K(+)-ATPase activity at a 50 µg/g dose. In contrast, high doses of GL and 18βGA increased gill transcript abundance of the tight junction protein claudin-31 (cldn-31). Other end points of gill paracellular transport differed in fishes fed LRDs. Tricellulin mRNA abundance was increased by high dose GL and decreased by high dose 18βGA, and cldn-23a and cldn-27b mRNA abundance significantly decreased in response to GL irrespective of dose. Despite the above observations, systemic end points of salt and water balance (i.e. serum [Na(+)] and [Cl(-)] as well as muscle moisture) were unaffected by LRDs. Therefore data suggest that LRDs can alter end points of ion transport in fishes but that overall salt and water balance need not be perturbed.

Metabonomics study of the effects of pretreatment with glycyrrhetinic acid on mesaconitine-induced toxicity in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Aconitum carmichaelii Debx. (Fuzi), a commonly use traditional Chinese medicine (TCM), has often been used in combination with Rhizoma Glycyrrhizae (Gancao) to reduce its toxicity due to diester diterpenoid alkaloids aconitine, mesaconitine, and hypaconitine. However, the mechanism of detoxication is still unclear. Glycyrrhetinic acid (GA) is the metabolite of glycyrrhizinic acid (GL), the major component of Gancao. In present study, the effect of GA on the changes of metabolic profiles induced by mesaconitine was investigated using NMR-based metabolomic approaches.

MATERIALS AND METHODS

Fifteen male Wistar rats were divided into a control group, a group administered mesaconitine alone, and a group administered mesaconitine with one pretreatment with GA. Their urine samples were used for NMR spectroscopic metabolic profiling. Statistical analyses such as orthogonal projections to latent structures-discriminant analysis (OPLS-DA), t-test, hierarchical cluster, and pathway analysis were used to detect the effects of pretreatment with GA on mesaconitine-induced toxicity.

RESULTS

The OPLS-DA score plots showed the metabolic profiles of GA-pretreated rats apparently approach to those of normal rats compared to mesaconitine-induced rats. From the t-test and boxplot results, the concentrations of leucine/isoleucine, lactate, acetate, succinate, trimethylamine (TMA), dimethylglycine (DMG), 2-oxo-glutarate, creatinine/creatine, glycine, hippurate, tyrosine and benzoate were significantly changed in metabolic profiles of mesaconitine-induced rats. The disturbed metabolic pathways include amino acid biosynthesis and metabolism.

CONCLUSIONS

GA-pretreatment can mitigate the metabolic changes caused by mesaconitine-treatment on rats, indicating that prophylaxis with GA could reduce the toxicity of mesaconitine at the metabolic level.

18β-glycyrrhetinic acid delivered orally induces isolated lymphoid follicle maturation at the intestinal mucosa and attenuates rotavirus shedding

Glycyrrhizin, an abundant bioactive component of the medicinal licorice root is rapidly metabolized by gut commensal bacteria into 18β-glycyrrhetinic acid (GRA). Either or both of these compounds have been shown to have antiviral, anti-hepatotoxic, anti-ulcerative, anti-tumor, anti-allergenic and anti-inflammatory activity in vitro or in vivo. In this study, the ability of GRA to modulate immune responses at the small intestinal mucosa when delivered orally was investigated. Analysis of cytokine transcription in duodenal and ileal tissue in response to GRA treatment revealed a pattern of chemokine and chemokine receptor gene expression predictive of B cell recruitment to the gut. Consistent with this finding, GRA induced increases in CD19(+) B cells in the lamina propria and B220(+) B cell aggregates framed by CD11c(+) dendritic cells in structures resembling isolated lymphoid follicles (ILF). Using a mouse model of rotavirus infection, GRA reduced the duration of viral antigen shedding, and endpoint serum antibody titers were higher in GRA-treated animals. Together the data suggest GRA delivered orally augments lymphocyte recruitment to the intestinal mucosa and induces maturation of B cell-rich ILF independently of ectopic antigenic stimulus. These results provide further support a role for dietary ligands in modulation of dynamic intestinal lymphoid tissue.

The effect of water loading on the urinary ratio of cortisone to cortisol in healthy subjects and a new approach to the evaluation of the ratio as an index for in vivo human 11β-hydroxysteroid dehydrogenase 2 activity

Factors that give rise to a large variation in the urinary ratio of free cortisone to cortisol (UFE/UFF) were investigated to accurately estimate 11β-hydroxysteroid dehydrogenase 2 (11β-HSD2) activity in humans in vivo. A water loading test was first carried out in two healthy subjects to examine the effect of water intake or urine volume on the urinary ratio of free cortisone to cortisol (UFE/UFF). The ratio was found to increase by water loading. We also examined urinary concentrations and amounts of cortisol, cortisone, creatinine, Na(+), K(+), and Cl(-), and urine volume, as possible factors affecting the urinary ratio (UFE/UFF), in 60 urine samples obtained from 15 healthy volunteers. Among these factors tested, the urinary concentration of cortisol was most highly correlated with the UFE/UFF ratio (r=-0.858), indicating that the in vivo activity of 11β-HSD2 (UFE/UFF) should fluctuate with the changes of the urinary concentration of cortisol. Based on the findings, we proposed a new estimation method of in vivo activity of 11β-HSD2 in humans, using the UFE/UFF ratio correlated with the urinary concentration of cortisol (UFE/UFF-cortisol concentration). Taking into consideration the intra-individual variabilities in the urinary concentration of cortisol, there were no significant within-day variations in 11β-HSD2 activity. The findings indicate that 11β-HSD2 activities can be accurately evaluated by simply measuring free cortisol and cortisone concentrations in spot urine samples. Furthermore, administrations of glycyrrhetinic acid in three healthy volunteers were performed to confirm the usefulness of the present assessment for the activity of 11β-HSD2.

[Effect of oral administration of glycyrrhetinic acid on six metal elements in rat serum]

OBJECTIVE

To determine glycyrrhetinic acid concentration in rat plasma and concentration of calcium (Ca), copper (Cu), iron (Fe), potassium (K), magnesium (Mg) and sodium (Na) in rat serum after oral administration by LC-MS/MS and the flame atomic absorption method, and analyze the effect of glycyrrhetinic acid on the six elements in serum.

RESULT

A similar variation trend between the concentration of glycyrrhetinic acid in plasma and that of Na, Cu elements in serum after oral administration of glycyrrhetinic acid was observed. Glycyrrhetinic acid in plasma at 2 h after administration reached the peak. Meanwhile, the concentration of Na and Cu at 4 h after the administration of glycyrrhetinic acid exhibited a significant increase (P < 0.05). Moreover, an increasing glycyrrhetinic acid dosage could result in the accumulation of Cu and Na in rat serum. Compared with the control group, the concentration of Cu and Na in the the glycyrrhetinic acid administration group with doses of 200 and 400 mg x kg(-1) revealed a significant increase (P < 0.05). However, glycyrrhetinic acid did not exhibit the great impact on the concentration of other elements in serum.

CONCLUSION

This study focuses on the effect of oral administration of glycyrrhetinic acid on six metal elements in rat serum and provides an experimental basis for the adverse effect of glycyrrhetinic acid in clinical-applications.

[Effect of decoction of turtle shell for anti-fibrosis combined with stronger neo-minophagen C on indices of hepatic fibrosis in chronic hepatitis B]

OBJECTIVE

To evaluate the effect of decoction of turtle shell for anti-fibrosis combined with stronger neo-minophagen C on the indices of hepatic fibrosis in chronic hepatitis B.

METHOD

The 94 cases of chronic viral hepatitis B patients were randomly divided into two groups. The treatment group was treated with stronger neo-minophagen C 100 mL dissolved in 10% dextrose 250 ml once a day intravenously, combined with decoction of turtle shell for anti-fibrosis one powder daily. And the control group was treated with stronger neo-minophagen C alone, 3 months as a course. Liver fibrosis indexes and liver function index were tested for two groups of patients before and after the treatment.

RESULT

Both the difference of liver fibrosis indexes between the treatment group and the control group and before and after the treatment in the treatment group had statistical significance (P < 0.01). Both the difference of liver function index between the treatment group and the control group and before and after the treatment in the treatment group had statistical significance (P < 0.01). The basic cure rate and total effective rate were 40% and 84.0% in the treatment group and 27.27% and 86.18% in the control group respectively with significant difference. The treatment group was superior to control group in the mean size of diameter of portal vein and the thickness of spleen (P < 0.01).

CONCLUSION

Decoction of turtle shell for anti-fibrosis combined with stronger neo-minophagen C could significantly improve the clinical efficacy and the liver fibrosis indexes and liver function index in chronic hepatitis B.

An over-the-counter moisturizer is as clinically effective as, and more cost-effective than, prescription barrier creams in the treatment of children with mild-to-moderate atopic dermatitis: a randomized, controlled trial

BACKGROUND

Atopic dermatitis (AD) is a prevalent skin disorder with significant cost of treatment. Several prescription device moisturizers have been approved by the FDA to treat AD but are significantly more expensive than well-crafted over-the-counter (OTC) moisturizers. No studies have been performed to compare both the clinical efficacy and cost-efficacy of these prescription devices to OTC moisturizers.

PURPOSE

The purpose of this study is to compare the clinical efficacy and cost-efficacy of a glycyrrhetinic acid-containing barrier repair cream (BRC-Gly, Atopiclair®), a ceramide-dominant barrier repair cream (BRC-Cer, EpiCeram®) and an OTC petroleum-based skin protectant moisturizer (OTC-Pet, Aquaphor Healing Ointment®) as monotherapy for mild-to-moderate AD in children.

METHODS

Thirty-nine patients, age 2-17 years, with mild-to-moderate AD were randomized 1:1:1 to receive one of three treatments-BRC-Gly, BRC-Cer or OTC-Pet-with instructions to apply the treatment three times daily for three weeks. Disease severity and improvement was assessed at baseline and on days 7 and 21.

RESULTS

No statistically significant difference for any efficacy assessment was found between the three groups at each time point. The OTC-Pet was found to be at least 47 times more cost-effective than BRC-Gly or BRC-Cer.

LIMITATIONS

The relatively small sample size of 39 subjects was not sufficient to establish OTC-Pet as superior treatment in AD.

CONCLUSIONS

OTC-Pet is as effective in treating mild-to-moderate AD as both BRC-Gly and BRC-Cer and is at least 47 times more cost-effective.

NAME OF REGISTRY

II-AF-ATD-Aquaphor, Comparing the Efficacy and Cost-Effectiveness of Aquaphor to Atopiclair and EpiCeram in Children with Mild to Moderate Atopic Dermatitis. REGISTRATION IDENTIFIER: NCT01093469.

[Estimation of efficacy of Hexalyse used for the treatment of acute pharyngitis]

The objective of the present study was to elucidate the relationship between the activity of the interferon system at the local level and the frequency of the development of relapses of acute inflammation of pharyngeal mucosa. The secondary objective was to estimate the possibility, necessity, and efficacy of the correction of the abnormal local immune response with the use of immunomodulatory agents. A total of 45 patients presenting with acute pharyngitis were available for the examination. They were allocated to two groups comprised of 25 and 20 patients respectively. Those in group 1 were given Hexalyse, a composite preparation for the local application. The patients of group 2 were treated with Strepsils. The study included general and specialized otorhinological examination as well as the evaluation of interferon production at the local level by measuring (using immunoenzyme assay) the concentration of interferon-alpha in the saliva before and on days 3 and 5 after the initiation of therapy. It was shown that the adaptive mechanisms of pharyngeal mucosa in acute pharyngitis are realized through activation of the interferon system. Elimination of the inflammatory process was accompanied by normalization of interferon-alpha level in the saliva regardless of the therapeutic modality used. One third of the patients presenting with acute pharyngitis suffered insufficiency of interferon production. It is concluded that the inclusion of an immunomodulatory agent, such as Hexalyse, in the combined treatment of such patients activates biosynthesis of interferon-alpha and leads to the reduction in the frequency of relapses of the disease. The results of the study of the relationship between the concentration of interferon-alpha in the saliva, the duration of acute pharyngitis, and the frequency of its post-treatment relapses were used to develop the practical recommendations for the prescription of Hexalyse for the treatment of patients with this pathology.

In vitro and in vivo pharmacokinetics of two novel 1,3-cyclic propanyl phosphate ester prodrugs of 18β-glycyrrhetic acid in rats

The in vitro metabolism of two novel phosphate prodrugs of glycyrrhetic acid (GA) was studied by the method of incubation in the rat liver microsome and the in vivo plasma pharmacokinetics after injecting intravenously (i.v.) into six rats was investigated, respectively. The prodrugs diminished gradually with time and most of the parent drugs were released in 30 min in vitro. In this paper, the in vivo plasma concentration data were analyzed by compartmental modeling. Both the prodrugs and the corresponding released parent drugs could be described by a two-compartment model, which existed for 48 h in rats. The t(1/2) increases remarkably after i.v. administration to rats when compared with injecting the parent drugs directly.

[Dermatopharmacokinetic studies of liangfu cream in mice skin]

OBJECTIVE

To study the relationship between deposition content and time of the active ingredients in rat skin, and investigate the dermatopharmacokinetics of Liangfu Cream.

METHOD

The contents of paeonol, dictamnine, fraxinellone and glycyrrhetinic acid in rat skin were determined by HPLC. The dermatopharmacokinetics parameters were calculated by DAS software.

RESULT

The dermatopharmacokinetics of paeonol and glycyrrhetinic acid were two compartment model, while that of dictamnine and fraxinellone were one compartment model: T(1/2Ka) of four active ingredients were 0.307, 0.112, 0.146, 0.216 h, respectively; T(lag) of them were 0.006, 0.123, 0.136, 0.109 h, respectively; all the Tmax of them was 0.5 h; the Cmax, were 40.163, 1.607, 6.725, 100.553 microg x cm(-3), respectively; the t(1/2beta), were 14.719, 1.262, 0.838, 234.807 h, respectively; the AUC(0-infinity), were 16.987, 2.713, 9.345, 697.000 microg x cm(-3) x h(-1), respectively; and the MRT(0-infinity) were 3.662, 1.67, 1.585, 10.897, respectively.

CONCLUSION

The skin pharmacokinetics characteristic of four ingredients in Liangfu cream is lined with the cataplasm long time.

Efficacy and safety of intravenous stronger neo-minophagen C and S-adenosyl-L-methionine in treatment of pregnant woman with chronic hepatitis B: a pilot study

BACKGROUND

There have been no studies evaluating the efficacy and potential risks of stronger neo-minophagen C (SNMC) in pregnant women with chronic hepatitis B CHB.

MATERIAL/METHODS

A total of 36 pregnant women with CHB, but without severe complications, were randomized to intravenously receive SNMC or S-adenosyl-L-methionine (SAM) daily for 4 weeks or until birth. Normalization of serum alanine transaminase (ALT) and aspartate transaminase (AST) levels and changes in ALT and AST levels from baseline were determined. All neonates were regularly examined for up to 1 year.

RESULTS

Treatment with SNMC and SAM resulted in normalization of ALT levels at 4 weeks in 64.3% and 21.4% of patients, respectively (OR=6.60, 95% CI: 1.23-35.44, P=0.0540). SNMC and SAM significantly decreased ALT (from 558.28+/-390.24 to 47.07+/-24.94 IU/L, P<0.0001 and from 525.61+/-483.87 to 117.43+/-85.44 IU/L, P=0.0041, respectively) and AST (from 419.72+/-409.49 to 38.14+/-18.87 IU/L, P=0.0016, and from 510.78+/-621.58 to 79.93+/-63.25 IU/L, P=0.0152, respectively) at 4 weeks relative to baseline values. Hypokalemia was observed in 4 SNMC-treated patients and in 2 SAM-treated patients and hypernatremia in 3 SNMC-treated and in 3 SAM-treated patients. Hypertension was observed in 1 SNMC-treated patient. There was no significant difference in the volume of amniotic fluid or meconium between SNMC-treated and SAM-treated groups. All the neonates were physically normal at birth and at the 1-year follow-up examination.

CONCLUSIONS

Both SNMC and SAM improve liver function, with SNMC appearing more effective, in pregnant women with chronic hepatitis B without impact on fetal development.

In-vitro and in-vivo evaluation of oligoethylene esters as dermal prodrugs of 18β-glycyrrhetic acid

Novel polyoxyethylene esters of 18 β-glycyrrhetic acid (GA) were synthesized and evaluated as potential dermal prodrugs. The permeation of these prodrugs (1a-e) was studied in-vitro, using excised human skin membranes (SCE; stratum corneum/epidermis) mounted in Franz type cells, and in-vivo, evaluating the ability of these compounds to inhibit methyl nicotinate (MN)-induced skin erythema in healthy human subjects. All the esters synthesized showed a good water stability, while the enzymatic hydrolysis rate was significantly affected by the length of the polyoxyethylenic chain used as promoiety. In in-vitro percutaneous absorption studies, only esters 1b and 1c (respectively triethylen- and tetraethylenglycol derivatives) showed an increased flux through SCE membranes compared with GA. Furthermore, we observed an appreciable and sustained in-vivo topical anti-inflammatory activity of esters 1b and 1c compared with the parent drug.

Treatment of pruritus in mild-to-moderate atopic dermatitis with a topical non-steroidal agent

Atopiclair (Zarzenda) is a topical non-steroidal anti-inflammatory agent for the treatment of allergic diseases of the skin. Three main ingredients are contained in this product: glycyrrhetinic acid, telmesteine and Vitis vinifera extracts. Other ingredients include: allantoin, alpha-bisabolol, capryloyl glycine, hyaluronic acid, shea butter and tocopheryl acetate. Two previous randomized, double-blind, vehicle-controlled clinical studies provided evidence that Atopiclair is effective in the treatment of atopic dermatitis. This article presents an open, multicenter, sponsor-free, study on the anti-pruritic activity of this product in adult patients with mild-to-moderate atopic dermatitis. The Median Visual Analogue Scale (VAS) values were: at the start of the study (TO), median VAS was 48.5 mm; three weeks later (T1), median VAS was 34.1 mm (-14.4 mm from baseline); six weeks later (T2), median VAS was 24.6 mm (-23.9 mm from baseline). Statistical analysis revealed that differences between TO versus T1, TO versus T2 and T1 versus T2 were highly significant (p<0.001). Side effects (local burning) were relatively common, although mild in severity. On the basis of the results of this study, Atopiclair showed efficacy in relief of pruritus in adult patients with mild-to-moderate atopic dermatitis.

In vitro and in vivo evaluation of mPEG-PLA modified liposomes loaded glycyrrhetinic acid

In order to prolong the in vivo residence of glycyrrhetinic acid, a liposomes with surface modified by methoxy poly(ethyleneglycol) (mPEG)-PLA was prepared for the first time. The liposomes (C-LP) and long-circulating liposomes (LC-LP) were prepared by film-dispersion method using soybean phospholipid/cholesterol mixture (1:0.5 mol/mol), containing 5% (w/w) sodium deoxycholate, and 2% (w/w) mPEG-PLA (only for LC-LP). The diameter of LC-LP was 243.3+/-17.1 nm. The pharmacokinetics behaviors of the conventional injection and liposomes (C-LP and LC-LP) were compared after a single intravenous injection to rats. Pharmacokinetic parameters were calculated based on a two-compartment open model analysis. LC-CP had a 1.7-fold longer residence time (MRT), a 2.75-fold larger AUC and a 0.4-fold lower clearance compared with conventional injection, respectively. These results combined suggested that the LC-CP had a well-improved residence in rats.

A time course analysis of systemic administration of aqueous licorice extract on spatial memory retention in rats

In the present study, the time course of the effects of Glycyrrhiza glabra L. (Leguminosae) aqueous extract (GE), administered systemically to rats, on the spatial memory retention in the Morris water maze was investigated. The dose of glycyrrhizin (GL), i. e., 0.5, 2.5 and 5 mg/mL in daily water intake of GE was administered to three groups of rats. The first, second and third groups received GE for 1, 2 and 4 weeks, respectively (each group included 3 subgroups). Three additional control groups of animals received only tap water during the same periods of time. After terminating the treatments, all animals were trained for four days; each day included one block and each block contained four trials. Test trials were conducted 48 h after the completion of the training period. Nicotine (1 microg/side) was infused into the CA1 region of the hippocampus as a positive drug control. GE treatment decreased both escape latency and traveled distance, but not swimming speed, compared with control, suggesting significant spatial memory retention enhancement by GE. Statistical analysis did not show any significant difference between GE-treated animals and the nicotine group in escape latency and traveled distance. At the end of the testing trials plasma samples were collected and the concentrations of glycyrrhetinic acid (GA) as a major metabolite of GL were measured in the different groups of treated rats. The maximum concentration was observed after four weeks of GE administration at 5 mg/mL of GL. These results showed that the enhancement effect of GE on spatial memory retention does not correlate with GA blood levels.

Preparation, characterization and uptake by primary cultured rat hepatocytes of liposomes surface-modified with glycyrrhetinic acid

3-succinyl-30-stearyl glycyrrhetinic acid (Suc-GLAOSt) was synthesized as a targeting molecule, and incorporated in ordinary to liposomes (LP) to prepare a liposome surface-modified with glycyrrhetinic acid (LP-GLA), which could bind to the hepatocyte through the specific binding site of glycyrrhetinic acid (GLA) on the surface of rat cellular membrane. The maximal molar ratio of Suc-GLAOSt to total lipids in LP-GLA was 1:10. Calcein loaded liposome (Cal-LP) and calcein loaded LP-GLA (Cal-LP-GLA) were prepared by an ethanol injection method. The average diameter of Cal-LP and Cal-LP-GLA was 65 nm +/- 16 nm and 68 nm +/- 21 nm, respectively. The characteristics of cellular uptake of the two types of liposome were investigated through cellular uptake and competitive inhibition experiments. The uptake of Cal-LP-GLA by rat hepatocytes was markedly higher (3.3-fold) than that of Cal-LP (P < 0.01). The uptake of Cal-LP-GLA was inhibited, but the uptake of Cal-LP was not influenced by adding extraneous GLA. LP-GLA may be internalized by hepatocytes via the specific binding site, and can be used as a novel and promising carrier for targeting drug delivery to hepatocytes.

Hepatic stellate cell-targeted delivery of M6P-HSA-glycyrrhetinic acid attenuates hepatic fibrogenesis in a bile duct ligation rat model

BACKGROUND/AIMS

Hepatic stellate cells (HSCs) play a key role in fibrogenesis. Here, we used mannose-6-phosphate-modified human serum albumin (M6P(26)-HSA) as a selective carrier to deliver antifibrotic drug 18beta-glycyrrhetinic acid (18beta-GA) in experimental fibrosis animals, and tested its effect in injured liver tissues.

METHODS

Bile duct ligation (BDL) was performed to induce liver damage in rats. Masson's stain and immunocytochemistry were used to assess hepatic collagen deposits and uptakes of M6P(26)-HSA-GA in HSCs in rat livers. Gene expression profiles of procollagen type I alpha2, smooth muscle actin (SMA), and transforming growth factor-beta1 (TGF-beta1) were analysed by TaqMan and quantitative polymerase chain reaction assays. The depositions of M6P(26)-HSA-GA in the HSC-T6 cell line and primary HSCs were assessed by immunofluorescent staining.

RESULTS

Treatment with M6P(26)-HSA-GA at 10 mg/kg (three times/week for 2 weeks), but not the equivalent doses of free 18beta-GA and M6P(26)-HSA carrier alone, could significantly attenuate collagen deposits in BDL rat liver. Masson's stain and TaqMan assay revealed significant modulation of procollagen type I alpha2 in the BDL-injured liver. The depositions of M6P(26)-HSA-GA in HSCs were revealed by immunostaining with HSA and SMA markers. M6P(26)-HSA bound activated HSCs in vitro and the immunoreactivity of M6P(26)-HSA-GA was detected in the cytoplasm and cell surface of HSCs and HSC-T6 cells. The gene transcript levels of SMA and TGF-beta1 were modulated in HSC-T6 cells treated with M6P(26)-HSA-GA.

CONCLUSIONS

The M6P(26)-HSA holds promise as a targeting carrier for the liver or HSCs, which may be used to deliver 18beta-GA as a therapeutic agent to treat liver fibrosis.

18 Beta-glycyrrhetinic acid triggers curative Th1 response and nitric oxide up-regulation in experimental visceral leishmaniasis associated with the activation of NF-kappa B

The efficacy of 18beta-glycyrrhetinic acid (GRA), a pentacyclic triterpene belonging to the beta-amyrin series of plant origin, was evaluated in experimental visceral leishmaniasis. GRA is reported to have antitumor and immunoregulatory activities, which may be attributable in part to the induction of NO. Indeed, an 11-fold increase in NO production was observed with 20 microM GRA in mouse peritoneal macrophages infected with Leishmania donovani promastigotes. In addition to having appreciable inhibitory effects on amastigote multiplication within macrophages (IC(50), 4.6 microg/ml), complete elimination of liver and spleen parasite burden was achieved by GRA at a dose of 50 mg/kg/day, given three times, 5 days apart, in a 45-day mouse model of visceral leishmaniasis. GRA treatment resulted in reduced levels of IL-10 and IL-4, but increased levels of IL-12, IFN-gamma, TNF-alpha, and inducible NO synthase, reflecting a switch of CD4(+) differentiation from Th2 to Th1. This treatment is likely to activate immunity, thereby imparting resistance to reinfection. GRA induced NF-kappaB migration into the nucleus of parasite-infected cells and caused a diminishing presence of IkappaB in the cytoplasm. The lower level of cytoplasmic IkappaBalpha in GRA-treated cells resulted from increased phosphorylation of IkappaBalpha and higher activity of IkappaB kinase (IKK). Additional experiments demonstrated that GRA does not directly affect IKK activity. These results suggest that GRA exerts its effects at some level upstream of IKK in the signaling pathway and induces the production of proinflammatory mediators through a mechanism that, at least in part, involves induction of NF-kappaB activation.

Glycyrrhetinic acid, the active principle of licorice, can reduce the thickness of subcutaneous thigh fat through topical application

Cortisol is involved in the distribution and deposition of fat, and its action is regulated by the activity of 11beta-hydroxysteroid dehydrogenase. Glycyrrhetinic acid, the active principle of licorice root, blocks 11beta-hydroxysteroid dehydrogenase type 1, thus reducing the availability of cortisol at the level of adipocytes. We evaluated the effect of topical application of a cream containing glycyrrhetinic acid in the thickness of fat at the level of the thigh. Eighteen healthy women (age range 20-33 years) with normal BMI were randomly allocated to treatment, at the level of the dominant thigh, with a cream containing 2.5% glycyrrhetinic acid (n=9) or with a placebo cream containing the excipients alone (n=9). Before and after 1 month of treatment both the circumference and the thickness of the superficial fat layer of the thighs (by ultrasound analysis) were measured. The circumference and the thickness of the superficial fat layer were significantly reduced in comparison to the controlateral untreated thigh and to control subjects treated with the placebo cream. No changes were observed in blood pressure, plasma renin activity, plasma aldosterone or cortisol. The effect of glycyrrhetinic acid on the thickness of subcutaneous fat was likely related to a block of 11beta-hydroxysteroid dehydrogenase type 1 at the level of fat cells; therefore, glycyrrhetinic acid could be effectively used in the reduction of unwanted local fat accumulation.

[Preparation of liposomes surface-modified with glycyrrhetinic acid targeting to hepatocytes]

OBJECTIVE

To study the preparation of liposomes surface-modified with glycyrrhetinic acid targeting to hepatocytes.

METHOD

3-succinic-30-stearyl glycyrrhetinic acid(Suc-GAOSt), one of the amphiphilic glycyrrhetinic acid derivatives, was synthesized as targeting molecules, liposomes surface-modified with glycyrrhetinic acid has been produced with ethanol injection method.

RESULT

Targeting molecules can be mixed into the liposomal membrane. It was confirmed that the targeting molecules is 9% of the total lipids at the most in the liposomes.

CONCLUSION

Liposomes surface-modified with glycyrrhetinic acid was successfully prepared, which is considered to be a potential approach targeting to hepatocytes.

Acute intrarenal administration of cortisol has no effect on renal blood flow in hypertensive individuals

BACKGROUND

Cortisol is known to increase blood pressure. One possible mechanism is the reported increase in renal vascular resistance (RVR). It is unknown whether this is due to a direct effect of cortisol on the kidneys.

OBJECTIVE

To study the effect of infusion of cortisol directly into the renal artery on renal blood flow (RBF) and on renal 11beta-hydroxysteroid dehydrogenase (11beta-HSD)-mediated conversion of cortisol to cortisone in patients with primary hypertension.

DESIGN AND METHODS

Twenty-seven patients with primary hypertension participated in this study. Fifteen received placebo and 12 received glycyrrhetinic acid (GRA; 500 mg) orally 2.5 h before the study. After a 10 min infusion of 5% glucose, cortisol was infused in stepwise increasing doses (0.625, 1.25 and 2.5 microg/kg per min), for 10 min each dose. At the end of each infusion step, RBF was measured using the xenon-133 washout technique. Plasma samples from the femoral artery and renal vein were taken for measurement of cortisol and cortisone. Urine was collected for measurement of steroid concentrations for 6 h on the day before the infusion and for 6 h after the infusion.

RESULTS

After placebo or GRA, cortisol infusion did not change RVR, RBF or blood pressure. RVR values were 0.72 (0.45-0.89) mmHg/ml per min per 100 ml tissue [median (first and third quartiles)] and 0.71 (0.64-0.91) mmHg/ml per min per 100 ml tissue during infusion of 5% glucose and infusion of the highest dose of cortisol, respectively ( P= NS). Cortisol infusion increased the venous-arterial difference in plasma cortisone concentration across the kidney from 76 (40-115) nmol/l to 138 (100-186) nmol/l (P< 0.05) and increased the cortisol : cortisone ratios in the renal vein and in urine (both P< 0.05). As compared with placebo, administration of GRA increased the cortisol : cortisone ratios in peripheral and renal veins and in the urine.

CONCLUSION

Acute infusion of cortisol in high doses directly into the renal artery in patients with primary hypertension did not affect RBF or RVR. Infusion of cortisol resulted in increased cortisol-cortisone conversion by renal 11beta-HSD2, but the concurrent increase in renal and urinary cortisol : cortisone ratio suggests a relative insufficiency of renal 11beta-HSD2 activity as a result of enzyme saturation. This may enhance mineralocorticoid receptor stimulation by cortisol.

Synthesis of a targeting drug for antifibrosis of liver; A conjugate for delivering glycyrrhetin to hepatic stellate cells

The neoglycoproteins that consist of human serum albumin (HSA) modified with mannose 6-phosphate ([M6P]x-HSA) were synthesized, and they showed high binding property to hepatic stellate cells (HSC) by immunohistochemical analysis. In addition, an increased substitution (X) of 6-phosphated mannose (M6P) was associated with an increased accumulation in HSC. So the [M6P]x-HSA might be a carrier to deliver drugs to HSC. The antifibrotic drug, glycyrrhetin, was chosen to conjugate to M6P(26)-HSA. The result suggests there were 6 approximately 7 glycyrrhetin molecules having been conjugated to the carrier. Targeting glycyrrhetin to HSC might reduce its adverse affects and increase the efficacy.

Therapeutic effect of glycyrrhetinic acid in MRL lpr/lpr mice: implications of alteration of corticosteroid metabolism

Glycyrrhetinic acid (GA) inhibits 11beta-hydroxysteroid dehydrogenase and increases the levels and thus the action of endogenous glucocorticoid. We considered that GA could be used effectively for treatment of autoimmune diseases that have been treated by synthetic glucocorticoids. In this report, we demonstrated that GA delayed the development of autoimmune disease in spontaneously autoimmune strain MRL lpr/lpr (referred to as lpr) mice. GA was administered via drinking water at approximately 5 mg/kg/day for 170 days. An increase of urine protein levels in the mice treated with GA was delayed as compared to the control mice. After GA treatment began, urinary protein levels in the GA-treated mice were found to be significantly lower than vehicle-treated mice (p<0.05) between days 18 to 50. At 3 weeks of GA treatment serum IgG levels were lowered significantly in comparison with the control mice (p<0.03). In this circumstance, 11beta-HSD activities in liver and kidney were significantly inhibited by GA treatment (p<0.03, p<0.04 respectively). Concentration of corticosterone and dehydrocorticosterone in liver significantly increased after 3 weeks of GA treatment (p<0.02, p<0.01 respectively). In contrast to the local tissue levels of corticosteroids, the serum concentration of dehydrocorticosterone significantly decreased with GA treatment (p<0.02). These data suggest that GA could modify the local and systemic homeostasis of steroid metabolism in lpr mice. We concluded that the continuous treatment of GA is able to retard the development of autoimmune disease by suppressing urinary protein excretion and serum IgG levels in lpr mice. Modulation of local tissue levels as well as serum levels of corticosteroid by GA may thus be implicated in the therapeutic efficacy of GA.

The effects of pretreatment with glycyrrhizin and glycyrrhetinic acid on the retrorsine-induced hepatotoxicity in rats

A wide variety of medicinal herbs contain hepatotoxic pyrrolizidine alkaloids (PAs), and often cause acute and chronic liver damages in man. Liquorice, a known antihepatitis, is commonly used with PA-containing herbs concurrently, and hepatotoxicity induced by such combined uses was not pronounced. The present study is to investigate effects of glycyrrhizin (GL) and 18beta-glycyrrhetinic acid (GA), the major biologically active ingredients of liquorice, against PA-induced hepatotoxicity in rats. Single dose (35 mg/kg, i.p.) of retrorsine (RET), a typical potent hepatotoxic PA, was given to rats to induce liver injury. A single dose pretreatment with GL or GA prior to retrorsine challenge did not show hepatoprotection. However, when rats were pretreated with either GL (200 mg/kg/day, i.p.) or GA (10 mg/kg/day, i.p.) for three consecutive days prior to retrorsine exposure, the elevated serum GOT and GPT levels induced by retrorsine were significantly reduced. Serum levels of transaminases almost returned to normal (GOT: 56+/-2 (control), 104+/-5 (RET), 64+/-3 (GL + RET) and 59+/-3 (GA + RET). GPT: 40+/-2 (control), 90+/-7 (RET), 45+/-2 (GL + RET) and 45+/-4 (GA + RET) SF units/ml). Furthermore, no extensive hepatocellular damages were observed. The results demonstrated that a three-day pretreatment with either GL or GA exhibited protective effect on retrorsine-induced liver damage in rats.

Determination of 18 beta-glycyrrhetinic acid in human serum using the fully automated ALCA-system

We report a method for the determination of 18 beta-glycyrrhetinic acid (glycyrrhetinic acid) in human serum using the ALCA-system. The technology of the ALCA-system is based on the principles of adsorptive and desorptive processes between liquid and solid phases. The assay is run fully automated and selective. Procedural losses throughout the analysis are negligible, thereby allowing for external calibration. The calibration curve is linear up to 10 mg/l and concentrations as low as 10 micrograms/l are detectable. CV is 2.5% for within- and 7.5% for between-assay precision at a level of 50 micrograms/l and 1.2% for within- and 8.5% for between-assay precision at a level of 500 micrograms/l. Specific and expensive reagents are not necessary and time-consuming manual operations are not involved. This assay can be selected from a wide spectrum of methods at any time. Thus, the present method is well-suited for drug monitoring purposes in the routine laboratory. In a pharmacokinetic study we measured serum levels of glycyrrhetinic acid in ten healthy young volunteers after ingestion of 500 mg glycyrrhetinic acid. Maximum levels of glycyrrhetinic acid were 6.3 mg/l 2 to 4 hours after ingestion. Twenty-four (24) hours after ingestion seven probands still had glycyrrhetinic acid levels above the detection limit with a mean level of 0.33 mg/l.

[The toxicological characteristics of ammonium glycyrrhizinate (glycyram). A study of its acute and subacute toxicity]

A single parenteral and oral administration of ammonium glycyrrhizinate in rat and mice experiments showed that the compound is related to practically nontoxic drugs. Its repeated administration (30 times) into the stomach in a maximum daily therapeutic dose (7 mg/kg) and in a four-fold dose (28 mg/kg) did not cause signs of intoxication, essential changes in the hematological and integral parameters, shifts in the activity of serum enzymes, morphological changes in the cell structures of the internal organs. Administration of the drug in a dose of 28 mg/kg for a second time led to changes in the activity of some enzymes in the brain, the development of parenchymatous dystrophy of the liver which changed to acidophilic necrosis attended with signs of regeneration. Under conditions of a subacute experiment the maximum daily therapeutic dose of ammonium glycyrrhizinate may be considered practically nontoxic.

Increased sodium appetite and thirst in rat induced by the ingredients of liquorice, glycyrrhizic acid and glycyrrhetinic acid

In the rat, blocking 11 beta-OHSD with the active ingredient of liquorice, glycyrrhizic acid (GZA) or its hydrolytic product, 18 beta-glycyrrhetinic acid (GTA), caused potassium loss, increased water intake and a primary increase in salt appetite that was specific for sodium and not secondary to sodium loss. Intracerebroventricular injection of angiotensin II enhanced the sodium appetite but carbachol did not. The stimulating effects of GZA or GTA on intakes of water and NaCl resembled those caused by the administration of excessive amounts of mineralocorticoid. The results suggest that GZA- or GTA-induced drinking behaviour is mediated by circulating glucocorticoids. After liquorice blockade of 11 beta-OHSD, the peripheral and central mineralocorticoid receptors are no longer protected from glucocorticoid action.

Further studies on the mechanism of the mineralocorticoid action of licorice in humans

The pathogenesis of pseudohyperaldosteronism from licorice has been evaluated in 6 male volunteers taking daily 7 g of a commercial preparation of licorice for 7 days, corresponding to an intake of 500 mg/day of glycyrrhizic acid. Pseudohyperaldosteronism was evident during the treatment (increase of body weight, suppression of plasma renin activity and plasma aldosterone, reduction of serum potassium). The ratio (tetrahydrocortisol + allo tetrahydrocortisol)/tetrahydrocortisone in urine increased in 5 cases after 3 days of treatment, without an increase of plasma mineralocorticoid activity (PMA). In the 6th case the urinary ratio was unchanged and PMA increased from the pretreatment value. After 7 days of therapy the ratio remained high and PMA was not measurable in 3 cases, while in the other 3 cases the ratio returned to pretreatment and PMA was higher than pretreatment value. We conclude that the pseudohyperaldosteronism from licorice is initially related to decreased activity of 11 beta-hydroxysteroid-dehydrogenase and afterwards also a direct effect of licorice derivatives on mineralocorticoid receptors becomes evident in some cases. In other cases however the effect on the enzyme is prevailing probably due to individual factors.

Effectiveness of glycyrrhizin for oral lichen planus in patients with chronic HCV infection

Oral lichen planus (OLP), an intractable inflammatory disease characterized by a band-like lymphocytic invasion under the oral mucosa, is frequently associated with hepatitis C virus (HCV) infection. We investigated the effects of glycyrrhizin, which is used to treat chronic liver dysfunction, in nine patients with OLP who were positive for HCV antibody and HCV RNA. A control group, eight patients with OLP who were also positive for HCV antibody and HCV RNA, was given only dental cleaning. Glycyrrhizin (GL) was given intravenously, at a dose of 40 ml (0.2% solution) daily, for 4 consecutive weeks. Six (66.7%) of the nine patients given GL improved clinically (P = 0.0141 vs non-GL group), suggesting that GL is useful in treating OLP.

Bioavailability study of glycyrrhetic acid after oral administration of glycyrrhizin in rats; relevance to the intestinal bacterial hydrolysis

To clarify the metabolic fate of glycyrrhizin when orally ingested, we investigated the bioavailability of glycyrrhetic acid, the aglycone of glycyrrhizin, after intravenous or oral administration of glycyrrhetic acid (5.7 mg kg-1, equimolar to glycyrrhizin) or glycyrrhizin (10 mg kg-1) at a therapeutic dose in rat. Plasma concentration of glycyrrhetic acid rapidly decreased after its intravenous administration, with AUC of 9200 +/- 1050 ng h mL-1 and MRT of 1.1 +/- 0.2 h. The AUC and MRT values after oral administration were 10600 +/- 1090 ng h mL-1 and 9.3 +/- 0.6 h, respectively. After oral administration of glycyrrhizin, the parent compound was not detectable in plasma at any time, but glycyrrhetic acid was detected at a considerable concentration with AUC of 11700 +/- 1580 ng h mL-1 and MRT of 19.9 +/- 1.3 h, while glycyrrhetic acid was not detected in plasma of germ-free rats at 12 h after oral administration of glycyrrhizin. The AUC value of glycyrrhetic acid after oral administration of glycyrrhizin was comparable with those after intravenous and oral administration of glycyrrhetic acid, indicating a complete biotransformation of glycyrrhizin to glycyrrhetic acid by intestinal bacteria and a complete absorption of the resulting glycyrrhetic acid from intestine. Plasma glycyrrhizin rapidly decreased and disappeared in 2 h after intravenous administration. AUC and MRT values were 2410 +/- 125 micrograms min mL-1 and 29.8 +/- 0.5 min, respectively. Plasma concentration of glycyrrhetic acid showed two peaks a small peak at 30 min and a large peak at 11.4 h, after intravenous administration of glycyrrhizin, with an AUC of 15400 +/- 2620 ng h L-1 and an MRT of 18.8 +/- 1.0 h. The plasma concentration profile of the latter large peak was similar to that of glycyrrhetic acid after oral administration of glycyrrhizin, which slowly appeared and declined. The difference of MRT values (19.9 and 9.3 h) for plasma glycyrrhetic acid after oral administration of glycyrrhizin and glycyrrhetic acid suggests the slow conversion of glycyrrhizin into glycyrrhetic acid in the intestine.