Central hypertensinogenic effects of glycyrrhizic acid and carbenoxolone

Glycyrrhizae Radix et Rhizoma: The popular occurrence of herbal medicine applied in classical prescriptions

Glycyrrhizae Radix et Rhizoma is a well-known herbal medicine with a wide range of pharmacological functions that has been used throughout Chinese history. This review presents a comprehensive introduction to this herb and its classical prescriptions. The article discusses the resources and distribution of species, methods of authentication and determination chemical composition, quality control of the original plants and herbal medicines, dosages use, common classical prescriptions, indications, and relevant mechanisms of the active content. Pharmacokinetic parameters, toxicity tests, clinical trials, and patent applications are discussed. The review will provide a good starting point for the research and development of classical prescriptions to develop herbal medicines for clinical use.

Monoammonium glycyrrhizinate improves antioxidant capacity of calf intestinal epithelial cells exposed to heat stress in vitro

Dairy calves are highly susceptible to the negative effects of heat stress, which can cause organ hypoxia after blood redistribution, damage the intestinal barrier, and trigger intestinal oxidative stress. This study aimed to investigate the antioxidant effects of monoammonium glycyrrhizinate (MAG) on calf small intestinal epithelial cells under heat stress in vitro. Small intestinal epithelial cells were isolated from a 1-d-old healthy calf and purified by differential enzymatic detachment. The purified cells were divided into seven groups. The control group was cultured with DMEM/F-12 at 37 °C for 6 h, and the treatment groups were cultured with 0, 0.1, 0.25, 0.5, 1, or 5 μg/mL MAG at 42 °C for 6 h. Heat stress causes oxidative damage to cells. Adding MAG to the medium can significantly improve cell activity and reduce cellular oxidative stress. MAG significantly increased the total antioxidant capacity and superoxide dismutase activity caused by heat stress, and significantly decreased malondialdehyde and nitric oxide levels. The MAG treatment also reduced lactate dehydrogenase release, increased mitochondrial membrane potential, and decreased apoptosis under heat stress. MAG also upregulated the expression of the antioxidant-related genes, Nrf2 and GSTT1, in heat-stressed intestinal epithelial cells and significantly downregulated the expression of the heat shock response-related proteins, MAPK, HSP70, HSP90, and HSP27. From the above results, we conclude that 0.25 μg/mL MAG improves the capability of the antioxidant system in small intestinal epithelial cells to eliminate reactive oxygen species by activating antioxidant pathways, improving the oxidant/antioxidant balance, lowering excessive heat shock responses, and reducing intestinal oxidative stress.

Glycyrrhizin, the active compound of the TCM drug Gan Cao stimulates actin remodelling and defence in grapevine

Actin remodelling by a membrane-associated oxidative process can sense perturbations of membrane integrity and activate defence. In the current work, we show that glycyrrhizin, a muscle relaxant used in Traditional Chinese Medicine, can activate oxidative burst and actin remodelling in tobacco BY-2 cells, which could be suppressed by diphenylene iodonium, an inhibitor of NADPH oxidases. Glycyrrhizin caused a dose-dependent delay of proliferation, and induced cell death, which was suppressed by addition of indole-acetic acid, a natural auxin that can mitigate RboH dependent actin remodelling. To test, whether the actin remodelling induced by glycyrrhizin was followed by activation of defence, several events of basal immunity were probed. We found that glycyrrhizin induced a transient extracellular alkalinisation, indicative of calcium influx. Furthermore, transcripts of phytoalexins genes, were activated in cells of the grapevine Vitis rupestris, and this induction was followed by accumulation of the glycosylated stilbene α-piceid. We also observed that glycyrrhizin was able to induce actin bundling in leaves of a transgenic grape, especially in guard cells. We discuss these data in frame of a model, where glycyrrhizin, through stimulation of RboH, can cause actin remodelling, followed by defence responses, such as calcium influx, induction of phytoalexins transcripts, and accumulation of stilbene glycosides.

Composite ammonium glycyrrhizin has hepatoprotective effects in chicken hepatocytes with lipopolysaccharide/enrofloxacin-induced injury

Composite ammonium glycyrrhizin (CAG) has anti-inflammatory activity. Lipopolysaccharide (LPS) and enrofloxacin (ENR) induce liver damage; however, the mechanism underlying LPS/ENR-induced hepatic injury remains to be elucidated. In the present study, the mechanism of LPS/ENR-induced liver injury was investigated in vitro and the protective effects of CAG were also evaluated. Primary chicken hepatocytes were isolated and a model of LPS/ENR-induced hepatocyte injury was established. mRNA and protein expression levels were evaluated by reverse transcription-quantitative polymerase chain reaction and western blot, respectively. LPS/ENR exposure significantly increased supernatant aspartate aminotransferase (AST) and alanine aminotransferase (ALT). In the LPS/ENR-treated group, glutathione (GSH) and the antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities were significantly increased. Flow cytometry results revealed that the apoptotic rate significantly increased in the LPS/ENR-treated group compared with the control, while treatment with CAG given 24 h prior to LPS/ENR caused a significant decrease in the apoptotic rate compared with the model group. Furthermore, CAG treatment reversed LPS/ENR-associated alterations in the mRNA and protein expression of Caspase-3, apoptosis regulator Bcl-2 (Bcl-2) and Bcl-2 associated X-protein. The mitochondrial membrane potential significantly decreased and the mitochondrial microstructure was notably altered following exposure to LPS/ENR compared with the control. In conclusion, these results suggested that LPS/ENR-treated hepatocytes were damaged via apoptotic signaling pathways and CAG prevented LPS/ENR-induced hepatocyte injury.

Fermented milk containing Lactobacillus paracasei and Glycyrrhiza glabra has a beneficial effect in patients with Helicobacter pylori infection: A randomized, double-blind, placebo-controlled study

BACKGROUND

Lactobacillus paracasei and Glycyrrhiza glabra have been reported as having beneficial effects on Helicobacter pylori infection. We aimed to assess the efficacy and safety of fermented milk containing L paracasei HP7 and G glabra in patients with H pylori infection.

METHODS

This multicenter, prospective, randomized, double-blind, placebo-controlled clinical trial was conducted in 2 hospitals from April to December 2017. Patients with H pylori infection were randomized into either the treatment group (fermented milk with L paracasei HP7 and G glabra) or placebo group (fermented milk only) once daily for 8 weeks. The primary endpoint was the gastric load of H pylori measured by C-urea breath test (UBT). Secondary endpoints were histologic and clinical improvement.

RESULTS

A total of 142 patients were randomly allocated to the treatment (n = 71) or placebo groups (n = 71). Compared to baseline data, the quantitative value of C-UBT at 8 weeks was significantly reduced in the treatment group (from 20.8 ± 13.2% to 16.9 ± 10.8%, P = .035), but not in the placebo group (P = .130). Chronic inflammation improved significantly only in the treatment group (P = .013), whereas the neutrophil activity deteriorated significantly only in the placebo group (P = .003). Moreover, the treatment group had significant improvement in gastrointestinal symptoms (P = .049) and quality of life (P = .029). No serious adverse events were observed.

CONCLUSION

The combination of fermented milk containing L paracasei and G glabra reduced H pylori density and improved histologic inflammation. However, their mechanisms of action should be elucidated in further studies.

Protective effects of compound ammonium glycyrrhizin, L‑arginine, silymarin and glucurolactone against liver damage induced by ochratoxin A in primary chicken hepatocytes

Ochratoxin A (OTA) is a mycotoxin that is produced by fungi in improperly stored food and animal feed. It exhibits nephrotoxic, hepatotoxic, embryotoxic, teratogenic, neurotoxic, immunotoxic and carcinogenic effects in laboratory and farm animals. In the present study, the hepatotoxicity of OPA was investigated in chicken primary hepatocytes. On this basis, the cytoprotective effects of compound ammonium glycyrrhizin (CAG), L‑arginine (L‑Arg), silymarin (Sil) and glucurolactone (GA) were investigated in vitro. Hepatocytes were treated with OTA, which resulted in a significant decrease in cell viability and increases in serum aspartate transaminase and alanine transaminase activities, as determined by an MTT assay and commercial kits, respectively. Furthermore, following OTA treatment, the levels of hepatic antioxidants, such as superoxide dismutase and glutathione, were decreased, and the lipid peroxidation product malondialdehyde was increased, compared with the control group. However, pretreatment with CAG, L‑Arg, Sil and GA significantly ameliorated these alterations and Sil exerted the optimum hepatoprotective effect. The apoptotic rates were measured by flow cytometry and the results revealed that OTA increased cell apoptosis. The four types of hepatoprotective compounds employed in the present study decreased the apoptosis rate and significantly reversed OTA‑induced increases in the mRNA expression levels of caspase‑3, which was determined by reverse transcription‑quantitative polymerase chain reaction. Furthermore, B‑cell lymphoma‑2 (Bcl‑2) mRNA expression was increased in OTA‑treated cells when pretreated with CAG, L‑Arg, Sil and GA. However, no alterations in the mRNA expression of Bcl‑2‑associated X were observed in the L‑Arg and GA groups, compared with the OTA‑only group. These results indicate that OTA may exhibit hepatotoxicity in chickens and that CAG, L‑Arg, Sil and GA may protect the liver against this via anti‑oxidative and antiapoptosis mechanisms. In addition, CAG and GA are likely to mediate their effects through the mitochondrion‑dependent apoptosis pathway; however, the exact hepatoprotective mechanism of L‑Arg and GA require further investigation. Therefore, CAG, L‑Arg, Sil and GA are potential candidates for the prevention and treatment of chicken liver injury.

Ammonium glycyrrhizin counteracts liver injury caused by lipopolysaccharide/amoxicillin-clavulanate potassium

We treated isolated chicken primary hepatocytes with lipopolysaccharide/amoxicillin clavulanate potassium (LPS/AC) to model liver injury and investigate its underlying mechanisms. We also used this model to assess the cytoprotective effects of compound ammonium glycyrrhizin (CAG) in vitro. LPS/AC-induced injury decreased cell viability and increased the activity of serum aspartate transaminase and alanine transaminase. Levels of superoxide dismutase, glutathione, and glutathione peroxidase were lower than control, while levels of the oxidative product malondialdehyde and reactive oxygen species were higher. Treatment with CAG for 24 h ameliorated these changes. Caspase-3 activity assays and flow cytometry revealed increased apoptosis in the model group. However, apoptosis decreased after CAG treatment, as confirmed by Hoechst 33342 staining. We also observed changes in mitochondrial ultrastructure. Real-time PCR and western blot analyses showed that CAG treatment downregulated LPS/AC-induced RNA expression of caspase-3, caspase-9, bax, cytochrome c, and fas, and upregulated the expression of bcl-2. Mitochondrial cytochrome c was released into the cytosol and the inner mitochondrial membrane potential (ΔΨm) was decreased. Our results highlight CAG as a potential therapeutic agent to counteract LPS/AC-induced liver injury.

Pharmacological Effects of Glycyrrhiza spp. and Its Bioactive Constituents: Update and Review

The roots and rhizomes of various species of the perennial herb licorice (Glycyrrhiza) are used in traditional medicine for the treatment of several diseases. In experimental and clinical studies, licorice has been shown to have several pharmacological properties including antiinflammatory, antiviral, antimicrobial, antioxidative, antidiabetic, antiasthma, and anticancer activities as well as immunomodulatory, gastroprotective, hepatoprotective, neuroprotective, and cardioprotective effects. In recent years, several of the biochemical, molecular, and cellular mechanisms of licorice and its active components have also been demonstrated in experimental studies. In this review, we summarized the new phytochemical, pharmacological, and toxicological data from recent experimental and clinical studies of licorice and its bioactive constituents after our previous published review.

Formation of curcumin nanoparticles by flash nanoprecipitation from emulsions

Nanometric particles of a model hydrophobic substance curcumin were prepared by a novel method, namely, flash nanoprecipitation from a coarse oil-in-water emulsion. The method employs turbulent co-mixing of water with curcumin-loaded emulsion using manually-operated confined impingement jets mixer. A clear and stable dispersion of nanoparticles was formed in this process, and could be converted to dry, easily water-dispersible powder by spray drying. The mean size of the particles was about 40 nm by DLS, confirmed by Cryo-TEM. The obtained particles contained 20.4 wt% curcumin, X-ray analysis showed it was amorphous. The significant advantages of the studied process are its feasibility, speed and low cost. It does not require any special high-energy input equipment to reduce the droplet size of the initial emulsion as required by the vast majority of other methods, and relies on rapid turbulent mixing and on flow-induced shear stress formed in the simple, manually-operated mixer. Control experiments clearly indicate that employing emulsion, instead of a plain solution and flash nanoprecipitation instead of a simple antisolvent precipitation are advantageous in terms of particle size and stability.

Aqueous extract of Glycyrrhiza inflata inhibits aggregation by upregulating PPARGC1A and NFE2L2-ARE pathways in cell models of spinocerebellar ataxia 3

Spinocerebellar ataxia (SCA) types 1, 2, 3, 6, 7, and 17 and dentatorubropallidoluysian atrophy, as well as Huntington disease, are a group of neurodegenerative disorders caused by a CAG triplet-repeat expansion encoding a long polyglutamine (polyQ) tract in the respective mutant proteins. The cytoplasmic and nuclear aggregate formation, a pathological hallmark of polyQ diseases, is probably the initial process triggering the subsequent pathological events. Compromised oxidative stress defense capacity and mitochondrial dysfunction have emerged as contributing factors to the pathogenesis of polyQ diseases. The roots of licorice (Glycyrrhiza species) have long been used as an herbal medicine. In this study, we demonstrate the aggregate-inhibitory effect of Glycyrrhiza inflata herb extract and its constituents licochalcone A and ammonium glycyrrhizinate (AMGZ) in both 293 and SH-SY5Y ATXN3/Q75 cells, SCA3 cell models. The reporter assay showed that G. inflata herb extract, licochalcone A, and AMGZ could enhance the promoter activity of peroxisome proliferator-activated receptor γ, coactivator 1α (PPARGC1A), a known regulator of mitochondrial biogenesis and antioxidative response genes. G. inflata extract, licochalcone A, and AMGZ upregulated PPARGC1A expression and its downstream target genes, SOD2 and CYCS, in the 293 ATXN3/Q75 cell model. The expression of nuclear factor erythroid 2-related factor 2 (NFE2L2), the principal transcription factor that binds to antioxidant-responsive elements (AREs) to promote ARE-dependent gene expression when the cells respond to oxidative stress, and its downstream genes, HMOX1, NQO1, GCLC, and GSTP1, was also increased by G. inflata herb extract, licochalcone A, and AMGZ. Knockdown of PPARGC1A increased aggregates in ATXN3/Q75 cells and also attenuated the aggregate-inhibiting effect of the tested compounds. G. inflata extract and its constituents significantly elevated GSH/GSSG ratio and reduced reactive oxidative species in ATXN3/Q75 cells. The study results suggest that the tested agents activate PPARGC1A activity and NFE2L2-ARE signaling to increase mitochondrial biogenesis, decrease oxidative stress, and reduce aggregate formation in SCA3 cellular models.

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 d₈₄ in 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 EC₅₀ at 2.80 × 10^-10, 3.03 × 10^-11, 3.77 × 10^-11 and 4.65×10^-11 mol/L at d₀, d₂₈, d₅₆ and d₈₄, respectively. Existed iNOS was located at hepatocyte at d₀, stellate cells at d₂₈, stellate cells and macrophages at d_56, 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.

Inhibition of crystallization and growth of celecoxib nanoparticles formed from volatile microemulsions

The inhibitory effect of ammonium glycyrrhizinate (AG) on crystallization of celecoxib (CXB) nanoparticles in aqueous medium was studied. CXB nanoparticles in powder form were prepared by rapid evaporation of all solvents from a volatile oil-in-water microemulsion. A powder containing 13 wt % CXB was obtained by immediate conversion of microemulsion droplets into nanoparticles by spray drying. CXB was amorphous in this powder, which could be easily dispersed 1 wt % in water as nanoparticles. However, these particles crystallized rapidly upon dispersion, and a significant particle growth was observed. The natural surfactant, AG, which is US Food and Drug Administration approved for oral administration, inhibited crystallization of CXB, enabling a stable dispersion of nanoparticles with average size of 14 nm. Molecular dynamics simulations revealed rapid attachment of glycyrrhizinate to the growing CXB crystal and suggested that crystallization inhibition is due to interactions between the hydrophobic part of glycyrrhizinate and the phenyl moieties of CXB.