Managing children with frequent respiratory infections and associated wheezing: a preliminary randomized study with a new multicomponent nasal spray.

BACKGROUND: Preschoolers frequently have respiratory infections (RIs), which may cause wheezing in some subjects. Type 2 polarization may favor increased susceptibility to RIs and associated wheezing. Non-pharmacological remedies are garnering increasing interest as possible add-on therapies. The present preliminary study investigated the efficacy and safety of a new multi-component nasal spray in preschoolers with frequent RIs and associated wheezing. METHODS: Some preschoolers with these characteristics randomly took this product, containing lactoferrin, dipotassium glycyrrhizinate, carboxymethyl-beta-glucan, and vitamins C and D3 (Saflovir), two sprays per nostril twice daily for 3 months. Other children were randomly treated only with standard therapy. Outcomes included the number of RIs and wheezing episodes, use of medications, and severity of clinical manifestations. RESULTS: Preschoolers treated add-on with this multicomponent product experienced fewer RIs and used fewer beta-2 agonists than untreated children (P = 0.01 and 0.029, respectively). CONCLUSIONS: This preliminary study demonstrated that a multicomponent product, administered add-on as a nasal spray, could reduce the incidence of RIs and use of symptomatic drugs for relieving wheezing in children.

Physiology-Based Pharmacokinetic Study on 18ß-Glycyrrhetic Acid Mono-Glucuronide (GAMG) Prior to Glycyrrhizin in Rats.

To understand that 18ß-Glycyrrhetic acid 3-O-mono-ß-D-glucuronide (GAMG) showed better pharmacological activity and drug-like properties than 18ß-Glycyrrhizin (GL); a rapid and sensitive HPLC-MS/MS method was established for the simultaneous determination of GAMG and its metabolite 18ß-Glycyrrhetinic acid (GA) in rat plasma and tissues after oral administration of GAMG or GL. This analytical method was validated by linearity, LLOQ, specificity, recovery rate, matrix effect, etc. After oral administration, GAMG exhibited excellent Cmax (2377.57 ng/mL), Tmax (5 min) and AUC0-T (6625.54 mg/L*h), which was much higher than the Cmax (346.03 ng/mL), Tmax (2.00 h) and AUC0-T (459.32 mg/L*h) of GL. Moreover, GAMG had wider and higher tissue distribution in the kidney, spleen, live, lung, brain, etc. These results indicated that oral GAMG can be rapidly and efficiently absorbed and be widely distributed in tissues to exert stronger and multiple pharmacological activities. This provided a physiological basis for guiding the pharmacodynamic study and clinical applications of GAMG.

Brain-targeting, acid-responsive antioxidant nanoparticles for stroke treatment and drug delivery.

Stroke is the leading cause of death and disability. Currently, there is no effective pharmacological treatment for this disease, which can be partially attributed to the inability to efficiently deliver therapeutics to the brain. Here we report the development of natural compound-derived nanoparticles (NPs), which function both as a potent therapeutic agent for stroke treatment and as an efficient carrier for drug delivery to the ischemic brain. First, we screened a collection of natural nanomaterials and identified betulinic acid (BA) as one of the most potent antioxidants for stroke treatment. Next, we engineered BA NPs for preferential drug release in acidic ischemic tissue through chemically converting BA to betulinic amine (BAM) and for targeted drug delivery through surface conjugation of AMD3100, a CXCR4 antagonist. The resulting AMD3100-conjugated BAM NPs, or A-BAM NPs, were then assessed as a therapeutic agent for stroke treatment and as a carrier for delivery of NA1, a neuroprotective peptide. We show that intravenous administration of A-BAM NPs effectively improved recovery from stroke and its efficacy was further enhanced when NA1 was encapsulated. Due to their multifunctionality and significant efficacy, we anticipate that A-BAM NPs have the potential to be translated both as a therapeutic agent and as a drug carrier to improve the treatment of stroke.

De Novo Production of Glycyrrhetic Acid 3-O-mono-ß-D-glucuronide in Saccharomyces cerevisiae.

Glycyrrhetic acid 3-O-mono-ß-D-glucuronide (GAMG) is a rare compound in licorice and its short supply limits the wide applications in the pharmaceutical, cosmetic, and food industries. In this study, de novo biosynthesis of GAMG was achieved in engineered Saccharomyces cerevisiae strains based on the CRISPR/Cas9 genome editing technology. The introduction of GAMG biosynthetic pathway resulted in the construction of a GAMG-producing yeast strain for the first time. Through optimizing the biosynthetic pathway, improving the folding and catalysis microenvironment for cytochrome P450 enzymes (CYPs), enhancing the supply of UDP-glucuronic acid (UDP-GlcA), preventing product degradation, and optimizing the fermentation conditions, the production of GAMG was increased from 0.02 µg/L to 92.00 µg/L in shake flasks (4,200-fold), and the conversion rate of glycyrrhetic acid (GA) to GAMG was higher than 56%. The engineered yeast strains provide an alternative approach for the production of glycosylated triterpenoids.

Concurrent production of glycyrrhetic acid 3-O-mono-ß-d-glucuronide and lignocellulolytic enzymes by solid-state fermentation of a plant endophytic Chaetomium globosum.

Glycyrrhetic acid 3-O-mono-ß-d-glucuronide (GAMG) as an important derivative of glycyrrhizin (GL) shows stronger biological activities and higher sweetness than GL. The biotransformation process is considered as an efficient strategy for GAMG production, due to its mild reaction, high production efficiency and environmentally friendly status. In this study, licorice straw was used for the first time as a medium for GAMG and lignocellulosic enzyme production via solid-state fermentation (SSF) of endophytic fungus Chaetomium globosum DX-THS3. The fermentation conditions including particle size, temperature, seed age, inoculum size, and moisture of substrate were optimized. Furthermore, additional nitrogen sources and carbon sources were screened for GAMG production by C. globosum DX-THS3 of SSF. Under optimal fermentation conditions, the percent conversion of glycyrrhizin reached 90% in 15 days, whereas the control needed 35 days to achieve the same result. The productivity of optimization (P = 2.1 mg/g/day) was 2.33-fold that of non-optimization (P = 0.9 mg/g/day). Meanwhile, high activities of filter paper enzyme (FPase) (245.80 U/g), carboxymethyl cellulase (CMCase) (33.67 U/g), xylanase (83.44 U/g), and ß-glucuronidase activity (271.42 U/g) were obtained faster than those in the control during SSF. Our study provides a novel and efficient strategy for GAMG production and indicates C. globosum DX-THS3 as a potential producer of lignocellulolytic enzymes. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40643-021-00441-y.

Calorimetric Evaluation of Glycyrrhetic Acid (GA)- and Stearyl Glycyrrhetinate (SG)-Loaded Solid Lipid Nanoparticle Interactions with a Model Biomembrane.

Glycyrrhetic acid (GA) and stearyl glycyrrhetinate (SG) are two interesting compounds from Glycyrrhiza glabra, showing numerous biological properties widely applied in the pharmaceutical and cosmetic fields. Despite these appreciable benefits, their potential therapeutic properties are strongly compromised due to unfavourable physical-chemical features. The strategy exploited in the present work was to develop solid lipid nanoparticles (SLNs) as carrier systems for GA and SG delivery. Both formulations loaded with GA and SG (GA-SLNs and SG-SLNs, respectively) were prepared by the high shear homogenization coupled to ultrasound (HSH-US) method, and we obtained good technological parameters. DSC was used to evaluate their thermotropic behaviour and ability to act as carriers for GA and SG. The study was conducted by means of a biomembrane model (multilamellar vesicles; MLVs) that simulated the interaction of the carriers with the cellular membrane. Unloaded and loaded SLNs were incubated with the biomembranes, and their interactions were evaluated over time through variations in their calorimetric curves. The results of these studies indicated that GA and SG interact differently with MLVs and SLNs; the interactions of SG-SLNs and GA-SLNs with the biomembrane model showed different variations of the MLVs calorimetric curve and suggest the potential use of SLNs as delivery systems for GA.

O-glycosyltransferases from Homo sapiens contributes to the biosynthesis of Glycyrrhetic Acid 3-O-mono-ß-D-glucuronide and Glycyrrhizin in Saccharomyces cerevisiae.

Glycyrrhizin (GL) and Glycyrrhetic Acid 3-O-mono-ß-D-glucuronide (GAMG) are the typical triterpenoid glycosides found in the root of licorice, a popular medicinal plant that exhibits diverse physiological effects and pharmacological manifestations. However, only few reports are available on the glycosylation enzymes involved in the biosynthesis of these valuable compounds with low conversion yield so far. In mammals, glycosyltransferases are involved in the phase II metabolism and may provide new solutions for us to engineer microbial strains to produce high valued compounds due to the substrate promiscuity of these glycosyltransferases. In this study, we mined the genomic databases of mammals and evaluated 22 candidate genes of O-glycosyltransferases by analyzing their catalytic potential for O-glycosylation of the native substrate, glycyrrhetinic acid (GA) for its glycodiversification. Out of 22 selected glycosyltransferases, only UGT1A1 exhibited high catalytic performance for biosynthesis of the key licorice compounds GL and GAMG. Molecular docking results proposed that the enzymatic activity of UGT1A1 was likely owing to the stable hydrogen bonding interactions and favorite conformations between the amino acid residues around substrate channels (P82~R85) and substrates. Furthermore, the complete biosynthesis pathway of GL was reconstructed in Saccharomyces cerevisiae for the first time, resulting in the production of 5.98 ± 0.47 mg/L and 2.31 ± 0.21 mg/L of GL and GAMG, respectively.

Pharmacokinetics-based identification of pseudoaldosterogenic compounds originating from Glycyrrhiza uralensis roots (Gancao) after dosing LianhuaQingwen capsule.

LianhuaQingwen capsule, prepared from an herbal combination, is officially recommended as treatment for COVID-19 in China. Of the serial pharmacokinetic investigations we designed to facilitate identifying LianhuaQingwen compounds that are likely to be therapeutically important, the current investigation focused on the component Glycyrrhiza uralensis roots (Gancao). Besides its function in COVID-19 treatment, Gancao is able to induce pseudoaldosteronism by inhibiting renal 11ß-HSD2. Systemic and colon-luminal exposure to Gancao compounds were characterized in volunteers receiving LianhuaQingwen and by in vitro metabolism studies. Access of Gancao compounds to 11ß-HSD2 was characterized using human/rat, in vitro transport, and plasma protein binding studies, while 11ß-HSD2 inhibition was assessed using human kidney microsomes. LianhuaQingwen contained a total of 41 Gancao constituents (0.01-8.56 µmol/day). Although glycyrrhizin (1), licorice saponin G2 (2), and liquiritin/liquiritin apioside (21/22) were the major Gancao constituents in LianhuaQingwen, their poor intestinal absorption and access to colonic microbiota resulted in significant levels of their respective deglycosylated metabolites glycyrrhetic acid (8), 24-hydroxyglycyrrhetic acid (M2D; a new Gancao metabolite), and liquiritigenin (27) in human plasma and feces after dosing. These circulating metabolites were glucuronized/sulfated in the liver and then excreted into bile. Hepatic oxidation of 8 also yielded M2D. Circulating 8 and M2D, having good membrane permeability, could access (via passive tubular reabsorption) and inhibit renal 11ß-HSD2. Collectively, 1 and 2 were metabolically activated to the pseudoaldosterogenic compounds 8 and M2D. This investigation, together with such investigations of other components, has implications for precisely defining therapeutic benefit of LianhuaQingwen and conditions for its safe use.

Research progress on the protective effects of licorice-derived 18ß-glycyrrhetinic acid against liver injury.

The first description of the medical use of licorice appeared in "Shennong Bencao Jing", one of the well-known Chinese herbal medicine classic books dated back to 220-280 AD. As one of the most commonly prescribed Chinese herbal medicine, licorice is known as "Guo Lao", meaning "a national treasure" in China. Modern pharmacological investigations have confirmed that licorice possesses a number of biological activities, such as antioxidation, anti-inflammatory, antiviral, immune regulation, and liver protection. 18ß-glycyrrhetinic acid is one of the most extensively studied active integrants of licorice. Here, we provide an overview of the protective effects of 18ß-glycyrrhetinic acid against various acute and chronic liver diseases observed in experimental models, and summarize its pharmacological effects and potential toxic/side effects at higher doses. We also make additional comments on the important areas that may warrant further research to support appropriate clinical applications of 18ß-glycyrrhetinic acid and avoid potential risks.

In-vitro antitumor activity of compounds from Glycyrrhiza glabra against C6 glioma cancer cells: identification of natural lead for further evaluation.

A HP20 resin-based unique method was adopted to get an active fraction of the hydroalcoholic extract of G. glabra roots. The fraction showed potent cytotoxicity against cancer cell line and was further subjected to detailed phytochemical investigation to obtain ten biomarkers. The isolated compounds were also tested for the cytotoxicity against the C6 glioma cell line in vitro using MTT assay. Among the isolated compounds, glycyrrhetic acid (1), glabrol (6), and glabridin (9) exhibited significant cytotoxicity. The compounds showed a dose-dependent decrease in cell viability. The active compounds were subjected to molecular docking study against topoisomerase I and topoisomerase II to support the mechanism of antitumor activity.

Effects of Glycyrrhetic Acid on Human Chronic Myelogenous Leukemia Cells.

OBJECTIVES: Chronic myelogenous leukemia (CML) is a type of blood cancer that is initially treated with imatinib (first Abl kinase inhibitor). However, some patients with CML develop imatinib resistance. Several new generation drugs have been developed, but do not overcome this problem. Glycyrrhetic acid (GA) is a plant-derived pentacyclic triterpenoid that exhibits multiple pharmacological properties for the treatment of cancers. The current study aimed to investigate the effects of GA on the K562 cell line (Bcr-Abl positive leukemia). MATERIALS AND METHODS: The MTT cell proliferation assay was employed to evaluate the cytotoxic effect of GA compared with imatinib (positive control) against leukemia and normal blood cells. For detection of cell death, an apoptotic/necrotic/healthy assay was performed against the K562 cell line. To investigate the kinase inhibitory activity of GA, the Abl1 kinase profiling assay and a molecular docking study were performed. RESULTS: GA showed Abl kinase inhibitory activity with an IC50 value of 29.2 µM and induced apoptosis in the K562 cell line after 6 h of treatment. CONCLUSION: The current findings indicate that this class of plant extract could be a potential candidate for treatment of CML.

HMGB1 in nasal inflammatory diseases: a reappraisal 30 years after its discovery.

INTRODUCTION: High mobility group protein box 1 (HMGB1) is a protein belonging to the alarmin family. HMGB1 has a relevant role in starting the inflammatory cascade by means of receptors, such as RAGE and TLR. HMGB1 supports transcription of many genes in interactions with many transcription factors, including NF-kB. The axis HMGB1-RAGE-NF-kB has, therefore, a pivotal role in the inflammatory cascade. HMGB1 controls the production of several pro-inflammatory cytokines and the proliferation and activation of many inflammatory cells. AREAS COVERED: The present report concerns the role of HMGB1 in nasal inflammatory disorders, including allergic and non-allergic rhinitis, and chronic rhinosinusitis with nasal polyps. HMGB1 modulation has been the aim of several studies. The literature search included recent papers that covered this topic. EXPERT OPINION: As HMGB1 has a pivotal role in inflammatory events, its modulation could be attractive for designing new therapeutic strategies. In this regard, glycyrrhetic acid (GA), the active component of Glycyrrhiza glabra, can efficiently block HMGB1. Promising reports seem to suggest that GA could exert favorable anti-inflammatory activity in patients with nasal inflammatory disorders.

Simultaneous quantitation of glycyrrhetic acid and puerarin in plasma using ultra flow liquid chromatography tandem mass spectrometry and application in a pharmacokinetics study in healthy and alcoholic liver injury rats.

A rapid, sensitive, and accurate ultra flow liquid chromatography tandem mass spectrometry (UFLC-MS/MS ) method was developed and validated for simultaneous quantitation of glycyrrhetic acid and puerarin in plasma derived from healthy and alcoholic liver injury rats. Plasma samples from healthy and model rats were deproteinated with methanol using liquiritin as an internal standard. Chromatography separation was performed by a Waters BEH (ethylene-bridged hybrid) C18 column (2.1 × 50 mm; 1.7 µm) using a gradient elution from acetonitrile and water (containing 0.1% formic acid) and at a flow rate of 0.4 mL/min. Quantitation was performed on a Triple Quad 4500 tandem mass spectrometer coupled with an electrospray ionization source in negative multiple reaction monitoring mode. Specificity, carryover, dilution integrity, recovery, linearity, precision and accuracy, matrix effect, and stability were within acceptable limits. The newly established method was successfully applied to a pharmacokinetics study to investigate glycyrrhetic acid and puerarin in healthy and alcoholic liver injury rats.

Preparative separation of liquiritigenin and glycyrrhetic acid from Glycyrrhiza uralensis Fisch using hydrolytic extraction combined with high-speed countercurrent chromatography.

The objective of this paper was to develop a preparative method for the isolation and purification of liquiritigenin and glycyrrhetic acid from Glycyrrhiza uralensis Fisch using hydrolytic extraction combined with high-speed countercurrent chromatography (HSCCC). Liquiritigenin and glycyrrhetic acid were well hydrolyzed from liquiritin and glycyrrhizic acid by hydrochloric acid, respectively. The optimal extraction conditions were obtained by single-factor and orthogonal experiments, which were 100% ethanol, 1.5 mol/L hydrochloric acid, 1:25 ratio of solid to liquid, and extracted 2 h for one time. Using the two-phase solvent system of n-hexane-ethyl acetate-methanol-water (4:5:4:5, v/v), 2.1 mg liquiritigenin (the purity was 96.5% with a recovery of 87.6%) and 12.3 mg glycyrrhetic acid (the purity was 97.1% with a recovery of 74.4%) were obtained from 315-mg crude extraction by HSCCC. The retention ratio of stationary phase was 47.2%. Their structures were identified by HPLC, melting points, UV, Fourier-transform infrared, Electrospray ionization-MS, 1 H nuclear magnetic resonance (NMR), and 13 C NMR spectra. According to the antioxidant activity assays, liquiritigenin and glycyrrhetic acid had some scavenging abilities on 1,1-diphenyl-2-picrylhydrazyl free radicals; liquiritigenin had stronger scavenging ability on hydroxyl radicals.

Synthesis and Evaluation of Glycyrrhetic Acid-aromatic Hybrids as Antiinflammatory Agents.

BACKGROUND: Inflammation is a biological response of body tissues to harmful stimuli, so it is desirable to search for novel anti-inflammatory agents with improved pharmaceutical profiles and reduced adverse effects. OBJECTIVE: This study was to explore natural anti-inflammatory agents and improve therapeutic application of glycyrrhetic acid (GA) through molecular hybridization with active aromatics. METHODS: Fourteen novel GA-aromatic hybrids were synthesized and evaluated for their antiinflammatory activities by inhibiting LPS-induced nitric oxide (NO) release in RAW264.7 cells. The synthesized compounds were characterized by single-crystal X-ray diffraction, 1H NMR, 13C NMR and HRMS. RESULTS: The structure-activity relationship (SAR) study indicated that compounds with styryl displayed better NO inhibitory activity. Among them, compounds 2a and 3c exhibited the most promising activity with IC50 values of 9.93 µM and 12.25 µM, respectively. In addition, X-ray singlecrystal diffraction data for compounds 2e and 3c showed that the absolute configuration of GA skeleton was consistent with that of natural 18 ß-glycyrrhetic acid. CONCLUSION: The results showed that GA-aromatic hybrids were a new class of anti-inflammatory agents and this study provided useful information on further optimization.

Effect of celastrol combined medication on the inhibition of HepG2 cell proliferation / 中国药科大学学报

@#To study the inhibitory effect of celastrol respectively combined with glycyrrhetic acid, paclitaxel, and rhein on the proliferation of human hepatoma cell line HepG2. The MTT method was used to detect the survival rate of HepG2 cells. The cooperativity index(CI)and Jin′s formula method were used to determine the synergistic effect. Apoptosis and cell cycle arrest were detected, too. The results show that celastrol, glycyrrhetinic acid, rhein, and paclitaxel alone can inhibit the proliferation of HepG2 cells, respectively. Combination with glycyrrhetic acid, paclitaxel, and rhein, respectively, the inhibitory effect of celastrol on the proliferation of HepG2 cells was significantly enhanced. And the synergistic effect on the proliferation inhibition of HepG2 cells in some concentrations was displayed in the experiment. The cell apoptosis rate was improved(P< 0. 01)and more cells were arrested in G2/M phase. Celastrol respectively combined with glycyrrhetic acid, paclitaxel, and rhein displayed a synergistic inhibitory effect on the proliferation of HepG2 cells, and the effect was related to inducing cell apoptosis and increasing the cell cycle arrest in G2/M phase.

Modification, Antitumor Activity, and Targeted PPARγ Study of 18ß-Glycyrrhetinic Acid, an Important Active Ingredient of Licorice.

Licorice is a traditional Chinese medicine, which is often used as sweetener and cosmetic ingredients in food and pharmaceutical industries. Among them, glycyrrhetic acid is one of the most important agents. Studies have shown that glycyrrhetic acid exhibited antitumor activities as PPARγ agonist. However, the limited number of PPARγ glycyrrhetinic agonists and their high toxicity greatly limit the design based on the structure. Therefore, clarifying the binding mode between PPARγ and small molecules, we focused on the introduction of a natural active piperazine skeleton in the position of glycyrrhetinic acid C-3. According to the Combination Principle and the Structure-Based Drug Design, 19 glycyrrhetic acid derivatives were designed and synthesized as potential PPARγ agonists. Compounds 4c and 4q were screened as high-efficiency and low-toxicity lead compounds.

Glycyrrhetic acid monoglucuronide: sweetness concentration-response and molecular mechanism as a naturally high-potency sweetener.

Glycyrrhetic acid monoglucuronide (GAM) is obtained from the natural sweetener glycyrrhizin through enzymolysis. Its sweetness concentration-response (C-R) behavior in room-temperature in water was determined using two-alternative forced choice discrimination tests. The C-R equation of resultant hyperbolic curve relating sucrose equivalent (SE, %) to GAM concentration ([GAM], mg/L) was SE = 19.6 × [GAM]/(194.8 + [GAM]). From the C-R function, Pw (2) of GAM, relative to a 2% (w/v) sucrose reference, is more than 900, which has much higher potency than its precursor glycyrrhizin. Molecular modeling showed that GAM is finely bound into protein 1EWK through conventional hydrogen bonds, π-Alkyl interactions and Van der Waals bonds, which exhibited better protein inclusion than Glycyrrhizin. Thus, GAM could be developed as a new zero-calorie, naturally high-potency sweetener.

Study on Preparation of Triptolide-glycyrrhetic Acid Compound Microemulsion and Its Physicochemical Properties and in vitro Release Characteristics / 中国药房

OBJECTIVE： To establish content determination method of Triptolide-glycyrrhetic acid compound microemulsion， optimize the formula and investigate its physicochemical properties and release rate in vitro. METHODS： The content of Triptolide- glycyrrhetic acid compound microemulsion was determined by UPLC. The determination was performed on ACQUITY UPLC BEH C18 column with mobile phase consisted of 0.1％ formic acid aqueous solution-acetonitrile （gradient elution） at the flow rate of 0.4 mL/min. The column temperature was 40 ℃. The detection wavelength was set at 218 nm， and sample size was 5 μL. Pseudo-ternary phase diagrams were drawn by water titration method. Using oil phase， surfactants and co-surfactants as index， the formula was optimized， and in intro release characteristics was investigated by in vitro release test. RESULTS： The linear range of triptolide and glycyrrhetinic acid were 1-40 μg/mL（r＝0.999 7） and 10-400 μg/mL（r＝0.999 8）， respectively. The limits of quantitation were 0.5 and 0.8 μg/mL； the limits of detection were 0.1 and 0.2 μg/mL. RSDs of precision， stability and reproducibility tests were all less than 2％. Average recoveries were 100.32％-101.15％ （RSD＝0.36％， n＝6）， 99.78％-101.42％ （RSD＝0.59％，n＝6）. The optimal formula included that medium chain triglyceride as oil phase， polyethylene glycol hydroxy stearate as surfactants， ethanol as co-surfactants， water as water phase， the proportion of them was 8 ∶  28 ∶ 14 ∶ 50. The obtained microemulsion was O/W type， being transparent and clear， with average diameter， average polydispersity index and average viscosity of （62.38±3.44） nm， 0.096±0.001 and （26.84±1.10） mPa·S. Within 24 h， cumulative release rates of triptolide and glycyrrhetinic acid in obtained microemulsion were 99.8％ and 99.7％ （in PBS pH 2.0）， 99.3％ and 99.4％ （in PBS pH 7.4）， 98.9％ and 98.4％ （in PBS pH 9.0）， respectively. Triptolide and glycyrrhetinic acid released faster in the single microemulsion than in the compound microemulsion. CONCLUSIONS： Established content determination method is simple and stable. The optimized formula is stable and feasible. Obtained iriptolide-glycyrrhetinic acid compound microemulsion show better sustained-release effect than sigle microemulsion.

Hypertensive Crisis with Neurological Impairment Mimicking a Guillain-Barrè Syndrome: Searching for a Link.

Guillain-Barré syndrome (GBS) may be complicated by severe hypertension (HT) and in turns severe HT can occur with neurological damage mimicking a GBS, so that underlying causes should be investigated. We describe a case of a 62-year-old woman presented to the emergency department for hypertensive crisis with symmetric flaccid paralysis, hypotonia and hyporeflexia of both upper and lower limbs. Brain computed tomography, magnetic resonance imaging and lumbar puncture were normal. Laboratory investigations revealed severe hypokalemia, renal failure, liver impairment, rabdomyolysis, metabolic alkalosis, and low plasma renin and aldosterone levels. Continuous potassium replacement led to complete clinical resolution. A detailed history revealed chronic intake of 250 g/day black liquorice. Hypokalaemic muscle weakness may simulate a GBS. When serum potassium level falls below 2.5 mmol/l, rhabdomyolysis may occur. In this clinical case, an apparent mineralocorticoid excess syndrome was induced by chronic ingestion of liquorice. This latter contains the glycyrrhetic acid that inhibits the enzyme 11-ß-hydroxysteroid dehydrogenase enzyme type-2 leading an aldosterone-like effect and causing hypertension, hypokalemia, metabolic alkalosis and low renin values. The clinical presentation is similar to that observed in the primary aldosteronism, but in this syndrome plasma aldosterone levels are low rather than elevated as in primary aldosteronism. Liquorice-induced hypertension with severe hypokalemia and rhabdomyolysis is a rare condition and the initial presentation with acute muscle paralysis is still more unusual. Before performing instrumental examinations in middle-aged peoples with hypertension crisis and neurological impairment, a detailed clinical history is mandatory.