Protective effect of glycyrrhetinic acid against cantharidin-induced hepatotoxicity through reducing oxidative stress in mice

Background:Cantharidin(CTD)is a commonly used natural product with anticancer properties;however,it has significant adverse effects,particularly hepatotoxicity.Glycyrrhetinic acid(GA),the active component of licorice,shows potential hepatoprotective effects.The protective effects and mechanism of GA against CTD-induced hepatotoxicity are still unclear.Objective:This study aims to elucidate the effect and mechanism of GA on CTD-induced hepatotoxicity in mice experiments.Methods:Construction of CTD-induced hepatotoxicity models and oral gavage GA intervention for 14 d.The liver index,ALT,AST and LDH levels in the serum of the mice were examined;HE staining was performed to observe pathological changes in the liver.The MDA level and SOD activities in liver tissue were tested.Western blot was conducted to determine Keap1/Nrf2 signaling pathway-related protein expression.Results:The results showed that GA significantly reduced the levels of ALT,AST,and LDH in the serum,which were increased by CTD.Additionally,it also exerted a substantial inhibitory effect on the reduction of SOD activity and the elevation of malondialdehyde content in liver tissue.Notably,the phenomena of nuclear swelling,necrosis,and inflammatory infiltration of liver tissue were significantly attenuated following oral administration of GA in mice.Subsequent research has demonstrated that GA effectively suppressed the CTD-triggered upregulation of Keap1 while increasing the CTD-induced downregulation of Nrf2,HO-1,and NQO1.Conclusion:These findings suggested that GA may protect against CTD-induced hepatotoxicity in mice by exerting antioxidative stress through the Keap1/Nrf2 signaling pathway.

N-acetylcysteine and glycyrrhizin combination:Benefit outcome in a murine model of acetaminophen-induced liver failure

BACKGROUND Acetaminophen overdose is the most frequent cause of drug-induced liver failure in developed countries.Substantial progress has been made in understanding the mechanism of hepatocellular injury,but N-acetylcysteine remains the only effective treatment despite its short therapeutic window.Thus,other hepatoprotective drugs are needed for the delayed treatment of acetaminopheninduced hepatotoxicity.Our interest focused on glycyrrhizin for its role as an inhibitor of high mobility group box 1(HMGB1)protein,a member of the family of damage-associated molecular pattern,known to play an important pathological role in various diseases.AIM To investigate the efficacy of the N-acetylcysteine/glycyrrhizin combination compared to N-acetylcysteine alone in the prevention of liver toxicity.METHODS Eight-week-old C57BL/6J wild-type female mice were used for all our experiments.Mice fasted for 15 h were treated with acetaminophen(500 mg/kg)or vehicle(phosphate-buffered saline)by intraperitoneal injection and separated into the following groups:Glycyrrhizin(200 mg/kg);N-acetylcysteine(150 mg/kg);and N-acetylcysteine/glycyrrhizin.In all groups,mice were sacrificed 12 h following acetaminophen administration.The assessment of hepatotoxicity was performed by measuring plasma levels of alanine aminotransferase,aspartate aminotransferase and lactate dehydrogenase.Hepatotoxicity was also evaluated by histological examination of hematoxylin and eosin-stained tissues sections.Survival rates were compared between various groups using Kaplan-Meier curves.RESULTS Consistent with data published in the literature,we confirmed that intraperitoneal administration of acetaminophen(500 mg/kg)in mice induced severe liver injury as evidenced by increases in alanine aminotransferase,aspartate aminotransferase and lactate dehydrogenase but also by liver necrosis score.Glycyrrhizin administration was shown to reduce the release of HMGB1 and significantly decreased the severity of liver injury.Thus,the co-administration of glycyrrhizin and N-acetylcysteine was investigated.Administered concomitantly with acetaminophen,the combination significantly reduced the severity of liver injury.Delayed administration of the combination of drugs,2 h or 6 h after acetaminophen,also induced a significant decrease in hepatocyte necrosis compared to mice treated with N-acetylcysteine alone.In addition,administration of N-acetylcysteine/glycyrrhizin combination was associated with an improved survival rate compared to mice treated with only N-acetylcysteine.CONCLUSION We demonstrate that,compared to N-acetylcysteine alone,co-administration of glycyrrhizin decreases the liver necrosis score and improves survival in a murine model of acetaminophen-induced liver injury.Our study opens a potential new therapeutic pathway in the prevention of acetaminophen hepatotoxicity.

Effect of alprostadil combined with Diammonium glycyrrhizinate on renal interstitial fibrosis in SD rats

Objective:To observe effect of alprostadil combined with Diammonium glycyrrhizinate on renal interstitial fibrosis in SD rate.Methods:A total of 75 SD rate were randomly divided into A,B,C,D,E groups with 15 in each group.Rats in group A served as the control group received just only but tissue separation without modeling operation,while model of unilateral ureteral obstruction(UUO) was established in B,C,D,E groups.Rats in A,B group were given saline lavage placebo treatment,while rats in C,D,E groups were given dianunonium glycyrrhizinate and alprostadil injection.Five rats were sacrificed 1,2,3 weeks after modeling,serum creatinine level of femoral venous blood was determined.Transforming growth factor- β1(TCF- β1) and concentration of connective tissue growth factor(CTGF) were also detected by using ELISA.Line renal interstitial tissue was taken after HE staining,renal interstitial TGF- β1 and CTGF expression were detected by using immunohistochemical method.Results:Serum creatinine levels of B,C,D,E group at different time points in were significantly higher than that of group A(P<0.05);serum creatinine levels in group B were significantly higher than that of C,D,E group at each time point(P<0.05).Serum creatinine level of Croup E was significantly lower than C,D group after 2,3 weeks(P<0.05).Rate in A group at each time point showed no significant changes in TGF- β1 and CREA concentration in serum and kidney tissues(P>0.05);while serum and kidney tissue TGF- β1,concentration of CREA.expression of rats in B,C,D,E groups showed a gradual increasing trend over time.TCF- β1 and CREF of Group B in serum and kidney tissues at each time point were significantly higher than that of the other groups(P<0.05).TCF- β1 and CREF of Group E in serum and kidney tissues at each time point were significantly lower than that of B,C,D group at all time points in serum and kidney tissues(P<0.05).Conclusions:Alprostadil combined with diammonium glycyrrhizinate can significantly lower the expression of TGF- β1 and CTGF in serum and tissues of SD rat with renal interstitial fibrosis,thus inhibit rat renal interstitial fibrosis process.It has synergy protective effect.

Topical application of glycyrrhizin preparation ameliorates experimentally induced colitis in rats

AIM:To examine the efficacy of glycyrrhizin preparation(GL-p) in the treatment of a rat model of ulcerative colitis(UC).METHODS:Experimental colitis was induced by oral administration of dextran sodium sulfate.Rats with colitis were intrarectally administered GL-p or saline.The extent of colitis was evaluated based on body weight gain,colon wet weight,and macroscopic damage score.The expression levels of pro-inflammatory cytokines and chemokines in the inflamed mucosa were measured by cytokine antibody array analysis.The effect of GL-p on myeloperoxidase(MPO) activity in the inflamed mucosa and purified enzyme was assayed.RESULTS:GL-p treatment significantly ameliorated the extent of colitis compared to sham treatment with saline.Cytokine antibody array analysis showed that GL-p treatment significantly decreased the expression levels of pro-inflammatory cytokines and chemokines,including interleukin(IL)-1β,IL-6,tumor necrosis factor-α,cytokine-induced neutrophil chemoattractant-2,and monocyte chemoattractant protein-1 in the inflamed mucosa.Furthermore,GL-p inhibited the oxidative activity of mucosal and purified MPO.CONCLUSION:GL-p enema has a therapeutic effect on experimental colitis in rats and may be useful in the treatment of UC.

Glycyrrhizinate reduces portal hypertension in isolated perfused rat livers with chronic hepatitis

AIM:To investigate the effects of diammonium glycyrrhizinate(Gly)on portal hypertension(PHT)in isolated portal perfused rat liver(IPPRL)with carbon tetrachloride(CCl4)-induced chronic hepatitis.METHODS:PHT model was replicated with CCl4 in rats for 84 d.Model was identified by measuring the ascetic amounts,hepatic function,portal pressure in vivo,splenic index,and pathological alterations.Inducible nitric oxide synthase(iNOS)in liver was assessed by immunohistochemistry.IPPRLs were performed at d0,d28,d56,and d84.After phenylephrine-induced constriction,Gly was geometrically used to reduce PHT.Gly action was expressed as median effective concentration(EC50)and area under the curve(AUC).Underlying mechanism was exploited by linear correlation between AUC values of Gly and existed iNOS in portal triads.RESULTS:PHT model was confirmed with ascites,splenomegaly,serum biomarkers of hepatic injury,and elevated portal pressure.Pathological findings had shown normal hepatic structure at d0,degenerations at d28,fibrosis at d56,cirrhosis at d84in PHT rats.Pseudo lobule ratios decreased and collagen ratios increased progressively along with PHT development.Gly does dose-dependently reduce PHT in IPPRLs with CCl4-induced chronic hepatitis.Gly potencies were increased gradually along with PHT development,characterized with its EC50at 2.80×10-10,3.03×10-11,3.77×10-11and 4.65×10-11mol/L at d0,d28,d56and d84,respectively.Existed iNOS was located at hepatocyte at d0,stellate cells at d28,stellate cells and macrophages at d56,and macrophages in portal triads at d84.Macrophages infiltrated more into portal triads and expressed more iNOS along with PHT development.AUC values of Gly were positively correlated with existed iNOS levels in portal triads.CONCLUSION:Gly reduces indirectly PHT in IPPRL with CCl4-induced chronic hepatitis.The underlying mechanisms may relate to rescue NO bioavailability from macrophage-derived peroxynitrite in portal triads.

Anti-inflammatory effect of Diammonium Glycyrrhizinate in a rat model of ulcerative colitis

AIM： To explore the anti-inflammatory mechanism of Diammonium Glycyrrhizinate in a rat model of ulcerative colitis induced by acetic acid. METHODS： Spragur-Dawley female rats were divided into four groups： Diammonium Glycyrrhizinate group, dexamethasone group, acetic acid control and normal control group. Colonic inflammation was evaluated by disease activity index, gross morphologic damage, histological injury and colonic myeloperoxidase activity. Immunohistochemistry was used to detect the expression of NF-κB, TNF-α and ICAM-1 in colonic mucosa. RESULTS： Compared to the acetic acid control, both Diammonium Glycyrrhizinate and dexamethasone showed a significant anti-inflammatory effect （P 〈 0.01）. The expression of NF-κB, TNF-α and ICAM-1 in colonic mucosa was significantly lower in the Diammonium Glycyrrhizinate group and dexamethasone group than in the acetic acid group. CONCLUSION： Diammonium Glycyrrhizinate could reduce inflammatory injury in a rat model of ulcerative colitis. This may occur via suppression of NF-κB, TNF-αand ICAM-1 in colonic mucosa.

Glycyrrhizin attenuates HMGB1-induced hepatocyte apoptosis by inhibiting the p38-dependent mitochondrial pathway

AIM： To examine how High-mobility group box I （HMGB1） regulates hepatocyte apoptosis and, furthermore, to determine whether glycyrrhizin （GL）, a known HMGB1 inhibitor, prevents HMGBl-induced hepatocyte apoptosis.

Effects of Dietary β-Glucan and Glycyrrhizin on Non-Specific Immunity and Disease Resistance of the Sea Cucumber (Apostichopus japonicus Selenka) Challenged with Vibrio splendidus

Sea cucumbers, Apostichopus japonicus Selenka, were fed diets containing non-immunostimulant (basal diet), 0.2% β-glucan and 0.02% glycyrrhizin in a recirculatory water system for 45 days, and subsequently challenged with Vibrio splendidus by injection at 1.0×108 cfu/sea cucumber for 15 days.Phagocytic capacity (PC), intracellular superoxide anion production (ISAP), ly-sozyme (LSZ) activity and superoxide dismutase (SOD) activity in the coelomic fluid were analyzed on the 0th, 5th, 10th and 15th days after injection.Results showed that after the 45-day feeding period, PC, ISAP, LSZ activity and SOD activity in sea cucumbers fed with dietary β-glucan or glycyrrhizin were significantly higher than in those fed with the basal diet.On the 5th day after infection, all the immune parameters examined in the sea cucumbers injected with V.splendidus decreased in value significantly.On the 15th day, PC, ISAP and LSZ activity returned to levels similar to those on the 0th day.For the sea cucumbers injected with saline, there were no significant differences in all the immune parameters examined and in the cumulative morbidity during the 15-day challenging trial.After injecting with V.splendidus, the cumulative morbidity of sea cucumbers fed with the basal diet was significantly higher than those fed with dietary β-glucan or glycyrrhizin when challenged with V.splendidus challenged sea cucumber fed with the basal diet was significantly higher than those fed with dietary β-glucan or glycyrrhizin.There was no significant difference in cumulative morbidity between the dietary β-glucan and glycyrrhizin treatments over time.

Uptake of albumin nanoparticle surface modified with glycyrrhizin by primary cultured rat hepatocytes

AIM: To investigate the uptake difference between bovine serum albumin nanoparticle (BSA-NP) and bovine serum albumin nanoparticles with their surface modified byglycyrrhizin (BSA-NP-GL) and to develop a novel hepatocyte targeting BSA-NP-GL based on active targeting technology mediated by specific binding site of GL on rat cellular membrane. METHODS: Calcein loaded bovine serum albumin nanoparticles (Cal-BSA-NP) were prepared by desolvation process. Glycyrrhizin was conjugated to the surface reactive amino groups (SRAG) of Cal-BSA-NP by sodium periodate oxidization, which resulted in calcein-loaded bovine serum albumin nanoparticles with their surface modified by glycyrrhizin (Cal-BSA-NP-GL). The morphology of the two types of prepared nanoparticles (NP) was observed by transmission electron microscopy. The diameter of NP was measured with a laser particle size analyzer. The interaction between Cal-BSA-NP-GL and primary cultured hepatocytes was studied through cellular uptake experiments. The uptake amount of Cal-BSA-NPGL and Cal-BSA-NP by rat hepatocytes was determinedby fluorospectrophotometry. Uptake characteristics were investigated through experiments of competitive inhibition of specific binding site of GL. RESULTS: Both Cal-BSA-NP-GL and Cal-BSA-NP had regular spherical surfaces. The average diameter of CalBSA-NP-GL and Cal-BSA-NP was 77 and 79 nm respectively. The uptake amount of the two NP by hepatocytes reached its maximum at 2 h after incubation. The uptake amount of Cal-BSA-NP-GL by rat hepatocytes was 4.43-fold higher than that of Cal-BSA-NP. There was a significant difference in the uptake of Cal-BSA-NP-GL and Cal-BSA-NP by hepatocytes (P＜0.01). The uptake of Cal-BSA-NP-GL was inhibited when GL was added previously to isolated rat hepatocytes, and the uptake of Cal-BSA-NP was not affected by GL.CONCLUSION: A binding site of GL is present on the surface of rat hepatocytes, BSA-NP-GL may be internalized via this site by hepatocytes and can be used as a drug carrier for active targeting of delivery drugs to hepatocytes.

Effect of Discontinuous Administration of β -glucan and Glycyrrhizin on the Growth and Immunity of Pacific White Shrimp Litopenaeus Vannamei

A six-week growth trial was conducted to compare the effects of different feeding strate- gies of dietary immunostimulants on the growth and immunity of white shrimp Litopenaeus vannamei （4.70 ±0.20g）. Shrimps were fed with diet containing glycyrrhizin continuously, containing β -glucan continuously, discontinuously （seven days with diet containing β -gluseven days with diet without -glucan; two days with diet containing β-glucan following five days with diet without -glucan）,

Pseudo-hyperaldosteronism caused by compound glycyrrhizin tablets: a case report

Compound glycyrrhizin tablets(CGT)is a glycyrrhizin-containing preparation for the treatment of chronic hepatic diseases,it contained Glycyrrhizin,Monoammonium Glycyrrhizinate,Aminoacetic Acid and Methionine.CGT has been shown to have anti-inflammatory,anti-oxidative,and anti-viral effects.Although pseudo-hyperaldosteronism was reported as its important side effects,the frequency was unknown.A 59-year-old male patient with tuberculous pleurisy received CGT to prevent impairment in liver function which was caused by antituberculosis drugs.After more than one month,it appeared edema in the lower extremity,blood pressure increased,serum potassium lowed,serum sodium raised at the normal high limit.Finally,it was improved by suspending the CGT and diuretic treatment.

Influence of compound glycyrrhizin on liver functions, liver fibrosis indexes and inflammatory factors of patients with chronic hepatitis B

Objective:To investigate influence of Compound Glycyrrhizin on liver functions, liver fibrosis indexes and inflammatory factors of patients with chronic hepatitis B.Methods:A total of 96 cases of patients with chronic hepatitis B treated in our hospital from Jan2015 to Jun2016 were selected as subjects, and randomly divided to be 48 cases of observation group and 48 cases of control group. Patients in both of the two groups were received routine liver protecting drug treatment. For observation group, Compound Glycyrrhizin injection was given on the basis of routine treatment. Variations of liver function indexes, liver fibrosis indexes and inflammatory factors between the two groups before and after treatment were compared and observed.Results:No obvious difference showed on AST, ALT, ALB TBIL levels between two groups of patients before treatment;After treatment, AST, ALT, TBIL in two groups of patients were significantly decreased, ALB were significantly increased. Significant difference showed comparing with prior treatment;After treatment, AST, ALT and TBIL levels in observation group were (29.53±9.44) U/L, (32.36±10.93) U/L and (10.12±3.22) μmol/L, which were significantly lower than in control group. ALB levels in observation group were (43.57±12.42) g/L, which were significantly higher than ALB levels in control group. Before treatment, no statistical difference showed on HA, LN, IV-C and PCIII levels between two groups of patients. After treatment, HA, LN, IV-C and PCIII in two groups of patients were significantly decreased, which showed significant difference comparing with prior treatment;After treatment, HA, LN, IV-C and PCIII levels in observation group were (97.33±31.75) μg/L, (77.52±23.72) μg/L, (82.92±24.55) μg/L, (15.33±5.11) μg/L, which were significantly lower than in control group. Before treatment, no significant difference showed on IL-2, IL-6 and TNF- levels between two groups of patients;After treatment, IL-2 levels in two groups of patients were significantly increased, IL-6 and TNF-α were significantly decreased, the differences showed significance;After treatment, IL-2 levels in observation group were (131.48±30.63) U/mL, which were higher than IL-2 levels in control group. IL-6 and TNF-αlevels in observation group were (45.23±16.45) μg/L, (41.75±17.53) ng/L, which were lower than IL-6 and TNF-α levels in control group, differences showed significance.Conclusion:Compound Glycyrrhizin could effectively release liver fibrosis and inflammatory reactions for patients with chronic hepatitis B, and could further improve liver functions.

Regulating effect of glycyrrhetinic acid on bronchial asthma smooth muscle proliferation and apoptosis as well as inflammatory factor expression through ERK1/2 signaling pathway

Objective: To study the influence of glycyrrhetinic acid(GA) on bronchial asthma(BA)smooth muscle proliferation and apoptosis as well as inflammatory factor expression and its molecular mechanism.Methods: Male SD guinea pigs were selected and made into asthma models, bronchial asthma smooth muscle cells were cultured and divided into BA group, GA group and GA + LM group that were treated with serum-free RPMI1640 culture medium, serumfree RPMI1640 culture medium containing 50 ng/mL glycyrrhetinic acid, serum-free RPMI1640 culture medium containing 50 ng/mL glycyrrhetinic acid and 100 ng/mL LM22B-10 respectively; normal guinea pigs were collected and bronchial smooth muscle cells were cultured as control group. The cell proliferation activity as well as the expression of proliferation and apoptosis genes, inflammatory factors and p-ERK1/2 was determined.Results: Proliferation activity value and m RNA expression of Bcl-2, TNF-α, IL-4, IL-6,YKL-40, protein expression of p-ERK1/2 of airway smooth muscle cell in BA group were significantly higher than those of control group while m RNA expression levels of Bax,caspase-9 as well as caspase-3 were significantly lower than that of control group(P < 0.05); proliferation activity value and m RNA expression of Bcl-2, TNF-α, IL-4, IL-6, YKL-40, protein expression of p-ERK1/2 of airway smooth muscle cell in GA group were significantly lower than those of BA group(P < 0.05) while the m RNA expression levels of Bax, caspase-9 as well as caspase-3 were significantly higher than those of BA group(P < 0.05); proliferation activity value and m RNA expression of Bcl-2, TNF-α, IL-4, IL-6, YKL-40 of airway smooth muscle cell in GA + LM group were significantly higher than those of GA group(P < 0.05) while m RNA expression levels of Bax, caspase-9 as well as caspase-3 were significantly lower that of GA group(P < 0.05).Conclusion: GA can inhibit the proliferation of bronchial smooth muscle cells and reduce the expression of inflammatory factors by inhibiting the phosphorylation of ERK1/2.

Effects of glycyrrhetinic acid on collagen metabolism of hepatic stellate cells at different stages of liver fibrosis in rats

INTRODUCTIONLiver fibrosis is a dynamic course leading tocirrhosis from a various chronic liver diseases. Thepathological basis of fibrosis is the disturbance ofproduction and degradation of the extracellularmatrix (ECM), which causes accumulation of ECMin the liver[1,2].

Advances in Research on Anti-cancer Mechanism of 18β Glycyrrhetinic Acid

Glycyrrhiza uralensis Fisch has been used to treat the symptoms of organ fever, food poisoning, typhoid fever, sore throat, cough due to lung heat, children's diseases and so on since the ancient times. It is a solid Chinese herbal medicine which is good for the health. In recent years, it has been found that licorice extract also has excellent anti-cancer effect. The 18β glycyrrhetinic acid, obtained by hydrolysis of precursor glycyrrhizic acid, is a relatively efficient anti-cancer ingredient. 18β glycyrrhetinic acid can exert anti-cancer effects by inhibiting cancer cell proliferation, inducing apoptosis of cancer cells, inhibiting invasion and metastasis of cancer cells, preventing oxidation, inhibiting neovascularization, inhibiting lymphangiogenesis, and regulating hormone secretion. This paper reviewed the advances in research of the anticancer mechanism of 18β glycyrrhetinic acid, to provide a theoretical basis for future research.

Exploring the targets and molecular mechanism of glycyrrhetinic acid against diabetic nephropathy based on network pharmacology and molecular docking

BACKGROUND Diabetic nephropathy(DN)stands as the most prevalent chronic microvascular complication of diabetes mellitus.Approximately 50%of DN patients progress to end-stage renal disease,posing a substantial health burden.AIM To employ network pharmacology and molecular docking methods to predict the mechanism by which glycyrrhetinic acid(GA)treats DN,subsequently validating these predictions through experimental means.METHODS The study initially identified GA targets using Pharm Mapper and the TCMSP database.Targets relevant to DN were obtained from the Genecards,OMIM,and TTD databases.The Venny database facilitated the acquisition of intersecting targets between GA and DN.The String database was used to construct a protein interaction network,while DAVID database was used to conducted Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis and Gene Ontology(GO)analysis.Molecular docking experiments were performed using Autodock software with selected proteins.Experimental validation was conducted using renal proximal tubular cells(HK-2)as the study subjects.A hyperglycemic environment was simulated using glucose solution,and the effect of GA on cell viability was assessed through the cell counting kit-8 method.Flow cytometry was employed to detect cell cycle and apoptosis,and protein immunoblot(western blot)was used to measure the expression of proteins of the phosphatidylinositol 3-kinase(PI3K)/protein kinase B(AKT)signaling pathway and insulin resistance pathway,including insulin receptor(INSR),PI3K,p-PI3K,AKT,p-AKT,and glycogen synthase kinase-3(GSK3).RESULTS A total of 186 intersecting targets between GA and DN were identified,which were associated with 144 KEGGrelated enrichment pathways,375 GO biological process entries,45 GO cellular component entries,and 112 GO cellular function entries.Molecular docking demonstrated strong binding of GA to mitogen-activated protein kinase(MAPK)-1,SRC,PIK3R1,HSP90AA1,CASPASE9,HARS,KRAS,and MAPK14.In vitro experiments revealed that GA inhibited HK-2 cell viability,induced cell cycle arrest at the G2/M phase,and reduced apoptosis with increasing drug concentration.Western blot analysis showed that GA differentially up-regulated GSK3 protein expression,up-regulated AKT/p-AKT expression,down-regulated INSR,AKT,p-AKT,PI3K,and p-PI3K protein expression,and reduced p-PI3K/PI3K levels under high glucose conditions.CONCLUSION GA may protect renal intrinsic cells by modulating the PI3K/AKT signaling pathway,thereby inhibiting HK-2 cell viability,reducing HK-2 cell apoptosis,and inducing cell cycle arrest at the G0/G1 phase.

Synthesis and Anti-tumor Activity of Novel Glycyrrhetinic Acid Derivatives

Twenty-five derivatives of glycyrrhetinic acid（GA） modified on the A-ring,at C30 and C11 positions were synthesized.Their in vitro cytotoxicity against various cancer cell lines[henrietta lacks strain of cancer cells（HeLa）,human hepatocellular liver carcinoma cells（HepG2） and human gastric carcinoma cells（BGC-823）] was evaluated by standard MTT[3-（4,5-dimethyl-2-thiazol-yl）-2,5-diphenyl-2H-tetrazolium bromide] assay.All the tested derivatives were found to have stronger cell growth inhibitory than their parent compound GA.Among them,compounds 3a,5a,and 8d have similar activity on HeLa cell line,and compound 8a has similar activity on HeLa,HepG2 and BGC-823 cell lines as Gefitinib.

Pressured Microwave-assisted Hydrolysis of Crude Glycyrrhizic Acid for Preparation of Glycyrrhetinic Acid

A pressured microwave-assisted hydrolysis （PMAH） technique has been developed for hydrolyzing the crude glycyrrhizic acid （GA） extracted from licorice root to prepare glycyrrhetinic acid （GRA）. In order to optimize the efficiency of PMAH, several experimental parameters were investigated, including liquid-solid ratio, hydrolysis time, sulfuric acid concentration and hydrolysis temperature. The optimized hydrolysis conditions were as follows：pressured microwave-assisted hydrolysis of crude GA for 21 min （taking 15 min to reach 150 ℃, and holding it for 6 rain） at 150 ℃ （at a radiation power of 450 W） in 3%-5% sulfuric acid solution with the liquid-solid （ml.g-1 crude GA） ratio of 25 ： 1. As a result of the considerable saving in time and higher product yields （up to 90%）, PMAH was proved more effective than conventional methods.

Effect of glycyrrhetinic acid on Th1/Th2 balance in cough variant asthma mice

Objective:To evaluate the therapeutic effect of Glycyrrhetinic Acid on cough variant asthma(CVA)mice and to investigate the possible mechanism in reducing lung inflammation.Methods:48 young female Balb/c mice were divided into Control,CVA,Prednisone Acetate,Glycyrrhetinic Acid high-dose,Glycyrrhetinic Acid middle-dose and Glycyrrhetinic Acid lowdose groups randomly,with 8 mice in each group.The CVA mice model was established by ovalbumin(OVA)sensitization and OVA challenge,the animal asthma behavior was observed after drug administration,and the index of the lung of mice were recorded.The level of OVAsIgE in the bronchoalveolar lavage fluid(BALF)was tested by ELISA.The pathological changes of the lung tissue were observed by Hematoxylin and Eosin(H&E)staining.The protein expressions of T-bet,IFN-γ,Gata3,IL-4 and IL-13 in the lung tissue were determined by Western blot.Results:Compared with the CVA group,the index of lung of mice,the OVA-sIgE level in BALF and expression levels of Th2-related factor in the lung tissue of mice in Prednisone Acetate and Glycyrrhetinic Acid groups were significantly decreased(P<0.05 or P<0.01),the infiltration of inflammatory cells in the lung tissue was reduced,while expressions of Th1-related factor in the lung tissue was significantly increased(P<0.05 or P<0.01).Conclusion:Glycyrrhetinic acid has therapeutic effect on CVA mice,the underlying mechanism of Glycyrrhetinic acid alleviating lung impairment and airway inflammation may be associated with mediating the Th1/Th2 imbalance in the lung tissue.

Allergic Contact Dermatitis Syndrome Due to Tocopherol Acetate, in Addition to Glycyrrhetinic Acid

Natural vitamin E is suggested to have an antioxidant function. However, the synthetic form of vitamin E, DL-tocopherol, which has been widely used in topical ointments, may cause allergic contact dermatitis. Here, we report a case of allergic contact dermatitis with erythema multiforme-like eruption caused by a topical ointment. Patch testing indicated a positive allergic reaction to an anti-inflammatory ointment the patient had been using and its ingredient, DL-alpha-tocopheryl acetate (vitamin E). In addition, a positive reaction to glycyrrhetinic acid was observed. Both vitamin E and glycyrrhetinic acid are useful ingredients of topical applications. However, the possibility that both can cause contact dermatitis, albeit rarely, should be considered.