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.

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.

Synergistic Effects of 18β-glycyrrhetinic Acid Combined with Antituberculosis Drugs against Mycobacterium tuberculosis

The in vitro antibacterial activities of 18β-glycyrrhetinic acid alone or combined with first-line antituberculosis drugs including isoniazid（INH）,rifampicin（RFP） and streptomycin（SM） against Mycobacterium tuberculosis were detected using MABA method.The minimum inhibitory concentrations（MICs） of18β-glycyrrhetinic acid against M.tuberculosis H37Rv（ATCC 27294） and M.bovis（ATCC 19210） were 50 and 100 μg/m L,respectively.The MICs of two clinical drug-susceptible isolates and six drug-resistant isolates were 25-50 and 100-200 μg/m L,respectively.As 18β-glycyrrhetinic acid combined with INH,RFP and SM,they exhibited synergistic effects against six drug-resistant isolates,and MICs decreased significantly：MIC of INH decreased by 2-32 folds（FICIs 0.125-0.375）;MIC of RFP decreased by 4-8 folds（FICIs 0.240-0.490）;MIC of SM decreased by 4-16 folds（FICIs 0.165-0.460）.Traditional medicine monomer had low cytotoxicity on normal cell BHK-21 and could restraint SMMC fission.The results showed that 18β-glycyrrhetinic acid combined with anti-TB drugs（INH,RFP and SM） had good antibacterial activity against M.tuberculosis.These findings indicated that 18β-glycyrrhetinic acid might serve as the potential therapeutic compound for future development of anti-TB drugs.

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.

Glycyrrhetinic acid-triggered cytoprotective autophagy via inositolrequiring enzyme 1α-c-Jun N-terminal kinase cascade in non-small cell lung cancer cells

OBJECTIVE Glycyrrhetinic acid(GA),one of the main bioactive constituents of the famous Chinese medicinal herb Glycyrrhizauralensis Fisch,presents potent cytotoxicity to various cancer cells both in vitro and in vivo.Herein,we′d like to determine whether GA triggers autophagy in non-small cell lung cancer cells and the mechanisms involved.METHODS Cell proliferation was determined by MTT assay and colony formation.AnnexinⅤ/PI staining,Hoechst33342 staining,and Western blotting were used to detect GA-induced apoptosis.GA-induced autophagy was measured by expression of the lipid modification of light chain-3(LC3)and transfected with GFP-LC3 or GFP-RFP-LC3 plasmid.Pharmacological regulators,siRNA,and plasmid transfection were used to study the mechanisms of GA-triggered autophagy.RESULTS GA inhibited cell proliferation and induced apoptosis in a concentrationdependent manner in non-small cell lung cancer A549 cells.GA induced autophagyas evidenced by up-regulation of LC3-Ⅱexpression when combined treatment with chloroquine and induction of the red punta after GFP-RFP-LC3 plasmid transfection.Knockdown of autophagy related proteins(ATG)7,ATG 5,or beclin 1by siRNA,the expression of LC3-Ⅱand GFP-LC3 punt atriggered by GA were decreased.Furthermore,the c-Jun N-terminal kinase(JNK)pathways were activated after treatment with GA,and pretreatment with JNK inhibitor SP600125 or silence of JNK pathway by siRNA of JNK or c-jun obviously reduced GA-induced LC3-Ⅱexpression and GFP-LC3 punta formation.GA also stimulate dendoplasmic reticulum stress response by triggering inositol-requiring enzyme 1α(IRE1α)pathway,and knockdown of IRE1αinhibited the activation of JNK pathway and autophagy induced by GA.In addition,GA-induced cell proliferative inhibition and apoptosis were both enhanced when silence of autophagy as well as JNK pathway.CONCLUSION Our study demonstrated,for the first time,that GA induced a cytoprotective autophagy in non-small cell lung cancer cells by activating the IRE1α-JNK pathway,which might decreased the anti-cancer effects of GA.

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].

18beta-glycyrrhetinic acid induces ROS-mediated apoptosis to ameliorate hepatic fibrosis by targeting PRDX1/2 in activated HSCs

Hepatic stellate cells(HSCs)are essential drivers of fibrogenesis.Inducing activated-HSC apoptosis is a promising strategy for treating hepatic fibrosis.18beta-glycyrrhetinic acid(18b-GA)is a natural compound that exists widely in herbal medicines,such as Glycyrrhiza uralensis Fisch,which is used for treating multiple liver diseases,especially in Asia.In the present study,we demonstrated that 18b-GA decreased hepatic fibrosis by inducing the apoptosis in activated HSCs.18b-GA inhibited the expression of a-smooth muscle actin and collagen type Ⅰ alpha-1.Using a chemoproteomic approach derived from activity-based protein profiling,together with cellular thermal shift assay and surface plasmon resonance,we found that 18b-GA covalently targeted peroxiredoxin 1(PRDX1)and peroxiredoxin 2(PRDX2)proteins via binding to active cysteine residues and thereby inhibited their enzymatic activities.18b-GA induced the elevation of reactive oxygen species(ROS),resulting in the apoptosis of activated HSCs.PRDX1 knockdown also led to ROS-mediated apoptosis in activated HSCs.Collectively,our findings revealed the target proteins and molecular mechanisms of 18b-GA in ameliorating hepatic fibrosis,highlighting the future development of 18b-GA as a novel therapeutic drug for hepatic fibrosis.

18β-Glycyrrhetinic Acid Improves Cardiac Diastolic Function by Attenuating Intracellular Calcium Overload

Summary:Ranolazine,a late sodium current inhibitor,has been demonstrated to be effective on heart failure.18B-glycyrrhetinic acid(18β-GA)has the similar inhibitory effect on late sodium currents.However,its effect on diastolic function is still unknown.This study aimed to determine whether 18β-GA can improve the diastolic function and to explore the underlying mechanisms.Eighty male Sprague Dawley(SD)rats of Langendorff model were randomly divided into the following groups:group A,normal cardiac perfusion group;group B,ischemia-reperfusion group;group C,ischemia-reperfusion with anemoniasulcata toxinⅡ(ATX-Ⅱ);group D,ranolazine group;and group E,18β-GA group with four different concentrations.Furthermore,a pressure-overloaded rat model induced by trans-aortic constriction(TAC)was established.Echocardiography and hemodynamics were used to evaluate diastolic function at 14th day after TAC.Changes of free intracellular calcium(Ca27)concentration was indirectly detected by laser scanning confocal microscope to confirm the inhibition of late sodium currents.With the intervention of ATX-Ⅱon ischemia reperfusion injury group,5 umol/L ranolazine,and 5,10,20,40μmol/L 18β-GA could improve ATX-I-induced cardiac diastolic dysfunction.630 mg/kg glycyrrhizin tablets could improve cardiac diastolic function in the pressure-overloaded rats.18B-GA and ranolazine had similar effects on reducing the free calcium in cardiomyocytes.The study demonstrates that 18B-GA and glycyrrhizin could improve diastolic dysfunction induced by ischemia-reperfusion injury in Langendorff-perfused rat hearts and pressure-overloaded rats.The mechanism may be attributed to the inhibition of enhanced late sodium currents.

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.

EFFECT OF GLYCYRRHETINIC ACID ON DNA DAMAGE AND UNSCHEDULED DNA SYNTHESIS INDUCED BY BENZO（α）PYRENE

Glyeyrrhetinic acid (GA) is an active component of Glycyrrhiza uraleusis fisch,In this study,GA was found to inhibit ear edema and ornithine decarboxylase (ODC)activity induced by croton oil in mice. GA could also protect rapid DNA damage and decrease the unscheduled DNA synthesis induced by benzo(α)pyrene. The results demonstrate that GA has a potential cancer chemopreventive activity.

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.

Potential therapeutic targets for the prevention of diabetic nephropathy:Glycyrrhetinic acid

Uncontrolled hyperglycemia or poorly managed disease increases the propensityfor a number of diabetes-related complications targeting major organs includingthe heart, eyes, and kidney. Although the mechanisms by which diabetes inducescardiovascular diseases include oxidative stress and inflammation, when insulinresistance remains the key to the pathogenesis, as implicated in the two reviews inthis issue. This editorial mainly comments on the potential preventive applicationof glycyrrhetinic acid (or 18β-GA) in relation to diabetic nephropathy. The therapeuticor preventive effects of 18β-GA, as a hydrolytic product of glycy-rrhizicacid that is a component of licorice, have been appreciated in other disorders, buthave received much less attention in relation to diabetic complications. A study inthis issue has identified 18β-GA as a therapeutic for preventing diabeticnephropathy and provides evidence to support efficacy in cultured human renaltubule cells in vitro. Although it represents a pilot study, the observations supporta new therapeutic approach that warrants further ex-ploration.

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.

Study on the removal of NO_x from simulated flue gas using acidic NaClO_2 solution

The study on the removal of NOx from simulated flue gas has been carded out in a lab-scale bubbling reactor using acidic solutions of sodium chlorite. Experiments were performed at various pH values and inlet NO concentrations in the absence or presence of SO2 gas at 45℃. The effect of SO2 on NO oxidation and NO2 absorption was critically examined. The oxidative ability of sodium chlorite was investigated at different pH values and it was found to be a better oxidant at a pH less than 4. In acidic medium, sodium chlorite decomposed into C102 gas, which is believed to participate in NO oxidation as well as in NO2 absorption. A plausible NOx removal mechanism using acidic sodium chlorite solution has been postulated. A maximum NOx removal efficiency of about 81% has been achieved.

A ca. 2.2Ga Acidic Magmatic Event at the Northern Margin of the Yangtze Craton: Evidence from U-Pb Dating and Hf Isotope Analysis of Zircons from the Kongling Complex

Objective The Yangtze craton collisional orogeny at ca. extensional events at ca. 1 experienced Paleoproterozoic 1.95-2.0 Ga and post-orogenic 85 Ga related to amalgamation of the Columbia （Nuna） supercontinent （Zhao and Cawood, 2012）. A ca. 2.15 Ga suprasubduction zone ophiolitic melange was recongized in the Archean- Paleoproterozoic Kongling Complex of the northern Yangtze craton （Han et al., 2017）. However, the tectonic evolution in early Paleoproterozoic from 2.4 Ga to 2.2 Ga remains unclear. We report here the presence of a suite of Paleoproterozoic （2.2 Ga） granites in the Huangling dome, northern Yangtze craton, which may provide important insights into crustal growth processes in the craton prior to the assembly of Columbia.

Analyzing solubility of acid gas and light alkanes in triethylene glycol

Physical solvents such as ethylene glycol （EG）, diethylene glycol （DEG）, and triethylene glycol （TEG） are commonly used in wet gas dehydration processes with TEG being the most popular due to ease of regeneration and low solvent losses. Unfortunately, TEG absorbs significantly more hydrocarbons and acid gases than EG or DEG. Quantifying this amount of absorption is therefore critical in order to minimize hydrocarbon losses or to optimize hydrocarbon recovery depending on the objective of the process. In this article, a new correlation that fully covers the operating ranges of TEG dehydration units is developed in order to determine the solubility of light alkanes and acid gases in TEG solvent. The influence of several parameters on hydrocarbon and acid gas solubility including temperature, pressure, and solvent content is also examined.

Gas Chromatography Analysis of Resin and Fatty Acids from Laboratory Generated Bleach Plant Effluents

Laboratory generated spent bleached liquor from the chlorination, caustic extraction stage of mixed wood kraft pulp processing has been analyzed both qualitatively and quantitatively for various resin & fatty acids by using GC. A number of resin acids, saturated and unsaturated fatty acids, chloro fatty and resin acid have been detected and their concentrations are estimated. The results are compared with results on different agriculture residue/hardwood pulps, which were reported earlier. The concentrations of various compounds detected have also been compared with their reported LC50 values.

Adsorption of Naphthenic Acids from Dewaxed Vacuum Gas Oil by Activated Clay: Kinetics, Equilibrium and Thermodynamic Studies

This work was mainly concentrated on the removal of naphthenic acids(NAs) from dewaxed vacuum gas oil(VGO) by adsorption using a commercial grade activated clay(AC) adsorption during lube base oil refining. The NAs in dewaxed VGO cut-4 were identified by negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry(ESI FT-ICR MS). The AC sample from a refinery was characterized by XRD, BET, TG/DTA, and SEM. A series of experiments were carried out to investigate the performance of NAs adsorption by AC using a batch adsorption technique, in which some key experimental parameters such as temperature, contact time, initial concentration of NA in oil sample as well as the dosage of adsorbent were investigated. Equilibrium isotherms were analyzed using the Langmuir, Freundlich, Tempkin and Dubinin-Radushkevich(D-R) adsorption models. The pseudo-first order, the pseudo-second order, and intraparticle diffusion models were employed to describe the kinetics data. The results revealed that the D-R isotherm provided a better fit to the experimental data than other isotherms, and the adsorption kinetics followed the pseudo-first order kinetic equation. The thermodynamic data indicated that the adsorption process was feasible and spontaneous as an endothermic process. The results could provide a clear understanding of the NAs adsorption by AC during lube base oil processing at refineries.