Protective effects of glycyrrhizin against β₂-adrenergic receptor agonist-induced receptor internalization and cell apoptosis

Investigation of the Therapeutic Effect of Salbutamol on Endometriosis in a Mouse Model

Endometriosis is an immune chronic inflammatory disease, and there are currently no more effective drugs for treating endometriosis due to its unknown etiology. Salbutamol is a β2-adrenergic receptor (β2AR) agonist commonly used to treat asthma by selectively activating β2 receptors on airway smooth muscle and leukocytes, exerting bronchial dilation and synergistic anti-inflammatory effects. In recent years, β2AR agonists have been used in endometriosis studies, and we speculate that salbutamol may have a therapeutic effect on endometriosis. The purpose of this research was to explore the therapeutic effect of salbutamol on endometriosis mice. The mouse endometriosis model was established and treated with different doses of salbutamol. Endometrial lesions were harvested for pathological diagnosis, immunohistochemistry (IHC), Masson staining, and toluidine blue analysis. We found that the number and size of endometriotic lesions were all significantly decreased after 3 weeks of treatment with different doses of salbutamol on endometriosis model mice (P < 0.05). After Salbutamol treatment, the amount of mast cells (toluidine blue) and macrophages (F4/80) in the lesions as well as the expressions of interleukin (IL)-1β, tumor necrosis factor (TNF)-ɑ, platelet-derived growth factor subunit B (PDGFB), CD31, transforming growth factor (TGF)-β, Masson staining, BCL2, TUBB3, substance P (SP), and nerve growth factor (NGF) were significantly reduced (P < 0.05). These results suggested that salbutamol could effectively treat endometriosis in mice by reducing immune inflammatory cells and factors, angiogenesis, and fibrosis, increasing apoptosis of endometriotic lesions, and decreasing neurogenesis.

Evaluation of botanicals as potential COVID-19 symptoms terminator

Information about the coronavirus disease 2019 (COVID-19) pandemic is still evolving since its appearance in December 2019 and has affected the whole world. Particularly, a search for an effective and safe treatment for COVID-19 continues. Botanical mixtures contain secondary metabolites (such as flavonoids, phenolics, alkaloids, essential oils etc.) with many therapeutic effects. In this study, the use of herbal treatments against COVID-19 was evaluated. Medical synthetic drugs focus mainly on respiratory symptoms, however herbal therapy with plant extracts may be useful to relieve overall symptoms of COVID-19 due to the variety of bioactive ingredients. Since COVID-19 is a virus that affects the respiratory tract, the antiviral effects of botanicals/plants against respiratory viruses have been examined through clinical studies. Data about COVID-19 patients revealed that the virus not only affects the respiratory system but different organs including the gastrointestinal (GI) system. As GI symptoms seriously affect quality of life, herbal options that might eliminate these problems were also evaluated. Finally, computer modeling studies of plants and their active compounds on COVID-19 were included. In summary, herbal therapies were identified as potential options for both antiviral effects and control of COVID-19 symptoms. Further data will be needed to enlighten all aspects of COVID-19 pathogenesis, before determining the effects of plants on severe acute respiratory syndrome coronavirus 2.

Advances in Pharmacological Activities and Mechanisms of Glycyrrhizic Acid

Licorice (Glycyrrhiza glabra L.) is widely regarded as an important medicinal plant and has been used for centuries in traditional medicine because of its therapeutic properties. Studies have shown that metabolites isolated from licorice have many pharmacological activities, such as antiinflammatory, anti-viral, participation in immune regulation, anti-tumor and other activities. This article gives an overview of the pharmacological activities and mechanisms of licorice metabolites and the adverse reactions that need attention. This review helps to further investigate the possibility of licorice as a potential drug for various diseases. It is hoped that this review can provide a relevant theoretical basis for relevant scholars' research and their own learning.

Dose-dependent neuroprotective effect of oriental phyto-derived glycyrrhizin on experimental neuroterminal norepinephrine depletion in a rat brain model

The dose-dependent neuroprotective role of licorice-derived glycyrrhizin during subacute neuroterminal norepinephrine (NE) depletion was studied in rat brain. Experimental design included thirty 5-week-old male rats randomly divided into five groups. Compared to the saline-injected control group, the group receiving daily intraperitoneal injection of fusaric acid (FA; 5 mg/kg/b.w.) for 30 days showed pharmacological depletion of NE. The neuroprotective effects of three successively increasing oral doses of glycyrrhizin were examined in FA-treated rats. Neurochemical parameters and histo-/immunohistopathological changes in the hippocampus were examined. FA generated global hippocampal stress with altered neurobiochemical parameters, accompanied by immune-confirmed inflammatory tissue damage, and noticeable behavioral changes. Although glycyrrhizin after FA-induced intoxication did not correct the recorded drop in the NE level, it decreased the dopamine levels to control levels. Similarly, glycyrrhizin at a high dose restored the serotonin level to its normal value and blocked the FA-induced increase in the level of its metabolite, 5-hydroxyindoleacetic acid. The FA-induced rise in γ-aminobutyric acid (GABA) and histamine was alleviated after administration of a high dose of glycyrrhizin. This was accompanied by improvements in the bioenergetic status and neuronal regenerative capacity through recovery of ATP and brain-derived neurotrophic factor levels to the pre-intoxicated values. High doses of glycyrrhizin also ameliorated the FA-generated behavioral changes and oxidative damage, manifested by the reduction in the expression of cortical pro-apoptotic caspase 3 in the same group. This study suggests that glycyrrhizin can potentially mend most of the previously evoked neuronal damage induced by FA intoxication in the brain of an experimental rat model.

Mahuannin B an adenylate cyclase inhibitor attenuates hyperhidrosis via suppressing β2-adrenoceptor/cAMP signaling pathway

BACKGROUND

Based on the traditional application of traditional Chinese Medicines (TCMs), Ephedra Herba (EH) is used to cure cold fever by inducing sweating, whereas Ephedra Radix (ER) is used to treat hyperhidrosis. Although they come from the same plant, Ephedra sinica Stapf, but have play opposing roles in clinical applications. EH is known to contain ephedrine alkaloids, which is the driver of the physiological changes in sweating, heart rate and blood pressure. However, the active pharmacological ingredients (APIs) of ER and the mechanisms by which it restricts sweating remain unknown.

PURPOSE

The current work aims to discover the hidroschesis APIs from ER, as well as to establish its action mechanism.

METHODS

UPLC-Q/TOF-MS, PCA, and heat map were utilized for identifying the differences between EH and ER. HPLC integrated with a β₂-adrenoceptor (β₂-AR) activity luciferase reporter assay system was used to screen active inhibitors; molecular docking and a series of biological assays centered on β₂-AR-related signaling pathways were evaluated to understand the roles of APIs.

RESULTS

The opposite effect on sweating of EH and ER can be attributed to the APIs of amphetamine-type alkaloids and flavonoid derivatives. Mahuannin B is an effective anti-hydrotic agent, inhibiting the production of cAMP via suppression of adenylate cyclase (AC) activity.

CONCLUSION

The effects of EH and ER on sweat and β₂-AR-related signaling pathway are opposite due to different alkaloids and flavonoids of APIs in EH and ER. The present work not only sheds light on the hidroschesis action of mahuannin B, but also presents a potential target of AC in the treatment of hyperhidrosis.

Cimicifugamide from Cimicifuga rhizomes functions as a nonselective β-AR agonist for cardiac and sudorific effects

Cimicifuga rhizomes (CR) are used in the treatment of respiratory and cardiovascular diseases in traditional Chinese medicine, but their key effective components and mechanism of action have not yet been reported. In this study, the cardiac, antipyretic and sudorific effects of CR were evaluated using the toad heart failure in vitro model and mice fever and sweating in vivo models. Moreover, the UPLC/Q-TOF-MS-integrated β2-AR luciferase reporter gene assay system was used to screen the bioactive ingredients from CR extract, and the activity of this ingredient were verified using the above-mentioned in vitro and vivo models. Our results showed that CR had anti-heart failure, antipyretic and sweating effects, which could be antagonized by propranolol. On the other hand, cimicifugamide was screened as β2-AR agonist from CR and cimicifugamide could activate β1, 2-ARs more significantly than β3-AR in β-ARs selectivity assessment. The results not only revealed the key effective components and mechanism of CR in traditional use but also supplied a characteristic complementary ingredient for quality control of CR.

α-Hederin inhibits G protein-coupled receptor kinase 2-mediated phosphorylation of β2-adrenergic receptors

BACKGROUND

Recently is has been shown that α- and β-hederin increase the β2-adrenergic responsiveness of alveolar type II cells (A549) and human airway smooth muscle cells (HASM), respectively, by inhibiting the internalization of β2-adrenergic receptors (β2AR) under stimulating conditions. Internalization of β2AR is initiated by phosphorylations of certain serines and threonines by cAMP dependent protein kinase A (PKA) and G protein-coupled receptor kinases (GRK).

PURPOSE

To evaluate the effect of α-hederin on PKA and GRK2 mediated phosphorylation of GFP-tagged β2AR.

STUDY DESIGN

To study this process we performed In-Cell Western using isoprenaline stimulated HEK293 cells overexpressing β2AR as GFP fusion protein and specific antibodies against PKA (Ser345/346) and GRK2 (Ser355/356) phosphorylation sites.

RESULTS

There was no effect found on the PKA mediated phosphorylation (n = 14) but we could show that α-hederin (1 µM, 12 h) significantly inhibits GRK2 mediated phosphorylation at Ser355/356 by 11 ± 5% (n ≥ 29, p ≤ 0.01) under stimulating conditions compared to the positive control. In Förster resonance energy transfer (FRET) experiments using the isolated kinases in solution α-hederin did not show any influence neither to GRK2 nor to PKA.

CONCLUSION

Taken together, these results indicate that α-hederin acts as an indirect GRK2 inhibitor leading to a reduced homologous desensitization of β2AR-GFP in HEK293 cells.

PDK1/Akt/PDE4D axis identified as a target for asthma remedy synergistic with β2 AR agonists by a natural agent arctigenin

BACKGROUND

Asthma is a heterogenetic disorder characterized by chronic inflammation with variable airflow obstruction and airway hyper-responsiveness. As the most potent and popular bronchodilators, β2 adrenergic receptor (β2 AR) agonists bind to the β2 ARs that are coupled via a stimulatory G protein to adenylyl cyclase, thereby improving cAMP accumulation and resulting in airway smooth muscle relaxation. We previously demonstrated arctigenin had a synergistic function with the β2 AR agonist, but the target for this remained elusive.

METHOD

Chemical proteomics capturing was used to enrich and uncover the target of arctigenin in human bronchial smooth muscle cells, and reverse docking and molecular dynamic stimulation were performed to evaluate the binding of arctigenin and its target. In vitro enzyme activities and protein levels were demonstrated with special kits and Western blotting. Finally, guinea pig tracheal muscle segregation and ex vivo function were analysed.

RESULTS

Arctigenin bound to PDK1 with an ideal binding free energy -25.45 kcal/mol and inhibited PDK1 kinase activity without changing its protein level. Additionally, arctigenin reduced PKB/Akt-induced phosphorylation of PDE4D, which was first identified in this study. Attenuation of PDE4D resulted in cAMP accumulation in human bronchial smooth muscle. The inhibition of PDK1 showed a synergistic function with β2 AR agonists and relaxed the constriction of segregated guinea pig tracheal muscle.

CONCLUSIONS

The PDK1/Akt/PDE4D axis serves as a novel asthma target, which may benefit airflow obstruction.

Regulation of Th1/Th2 balance through OX40/OX40L signalling by glycyrrhizic acid in a murine model of asthma

BACKGROUND AND OBJECTIVE

Glycyrrhizic acid (GA) has been reported to have attenuating airway inflammation effects in asthma mouse model. However, the potential molecular mechanisms by which GA exerts anti-inflammatory effects on ovalbumin (OVA)-induced allergic asthma have not been well elaborated.

METHODS

The effect of GA on OVA-sensitized and challenged mice was investigated. The effect of GA on anti-OX40 mAb stimulated splenocytes from asthma mice model was also examined.

RESULTS

In OVA-induced asthmatic mice, GA treatment prevented the decrease of T helper1 cytokine (interferon (IFN)-γ) and the increase of T helper2 cytokines (interleukin (IL)-4, IL-5, IL-13) in bronchoalveolar lavage fluid (BALF), reduced serum immunoglobulin (Ig)E and OVA-specific IgE levels, prohibited the protein and mRNA expression of OX40 and OX40 Ligand (OX40L) in lung tissues, and the expression of OX40 in CD4(+) T cells and OX40L in CD11b(+) monocytes and CD19(+) B cells in spleens in a dose-dependent manner compared with the vehicle treatment (all P < 0.05). Moreover, OVA significantly increased the activation of p38 mitogen-activated protein kinase (MAPK) in lung tissues, whereas GA and anti-OX40L mAb markedly reduced phosphorylation of p38 MAPK. In addition, GA could inhibit the T cell proliferation and modulate the balance of Th1/Th2 in anti-OX40 mAb stimulated CD4(+) T cells from asthmatic spleens (all P < 0.05).

CONCLUSIONS

GA may exert a therapeutic effect on OVA-induced experimental asthma partly by regulating the Th1/Th2 balance through suppressing OX40-OX40L signalling and p38 MAPK activity. GA may be a promising treatment for asthma.

Integrative investigation of Semen Strychni nephrotoxicity and the protective effect of Radix Glycyrrhizae by a UPLC-MS/MS method based cell metabolomics strategy in HEK 293t cell lysates

Scheme of the cell metabolomics strategy workflow.

Liquorice, a unique "guide drug" of traditional Chinese medicine: a review of its role in drug interactions

ETHNOPHARMACOLOGICAL RELEVANCE

Liquorice is the root of Glycyrrhiza uralensis Fisch. or Glycyrrhiza glabra L., Leguminosae. It is a widely used herbal medicine native to southern Europe and parts of Asia and has beneficial applications in both the medicinal and the confectionery sectors. Unlike its usage in Europe, liquorice in traditional Chinese medicine is commonly combined with other herbs in a single prescription, as a unique "guide drug" to enhance the effectiveness of other ingredients, to reduce toxicity, and to improve flavor in almost half of Chinese herbal formulas. A review on phytochemical and pharmacological research to explain this unique "guide" effect is suggested for future investigations.

MATERIALS AND METHODS

The information was collected from scientific journals, books, and pharmacopeia. The studies about the traditional uses, randomized controlled trials, chemical, pharmacological and pharmacokinetic data related to liquorice-herb/drug interaction or combination were included in the review.

RESULTS

According to recent reports, the "guide" effect of liquorice is partially through components transformed in liquorice-drug interaction; altering enzyme activity of P450 isoforms, as evidenced by induction of model probe substrates; and modulation of drug transporter proteins such as intestinal P-glycoprotein.

CONCLUSION

The overview and comparison of traditional uses of liquorice with recent pharmacological studies and randomized controlled trials provide new insights into this ancient drug for future investigations and clinical use, especially in drug combination.

Bioactivity-integrated ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry for the identification of nuclear factor-κB inhibitors and β2 adrenergic receptor agonists in Chinese medicinal preparation Chuanbeipipa dropping pills

A simple and dual-target method based on ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry combined with dual-bioactive [nuclear factor-κB (NF-κB) and β2 -adrenergic receptor] luciferase reporter assay systems was developed to rapidly characterize the chemical structure of various bioactive compounds of TCM preparations. Chuanbeipipa dropping pills, a traditional Chinese medicine preparation used for the clinical therapy of chronic obstructive lung disease and cough caused by bronchial catarrh, was analyzed with this method. Potential anti-inflammatory and spasmolytic constituents were screened using NF-κB and β2 -adrenergic receptor activity luciferase reporter assay systems and simultaneously identified according to the time-of-flight mass spectrometry data. One β2-adrenergic receptor agonist (ephedrine) and two structural types of NF-κB inhibitors (platycosides derivatives and ursolic acid derivatives) were characterized. Platycodin D3 and E were considered new NF-κB inhibitors. Further cytokine and chemokine detection confirmed the anti-inflammatory effects of the potential NF-κB inhibitors. Compared with conventional fingerprints, activity-integrated fingerprints that contain both chemical and bioactive details offer a more comprehensive understanding of the chemical makeup of plant materials. This strategy clearly demonstrated that multiple bioactivity-integrated fingerprinting is a powerful tool for the improved screening and identification of potential multi-target lead compounds in complex herbal medicines.

Dual-bioactivity-based liquid chromatography-coupled quadrupole time-of-flight mass spectrometry for NF-κB inhibitors and β2AR agonists identification in Chinese Medicinal Preparation Qingfei Xiaoyan Wan

Traditional Chinese medicine (TCM) preparations have been used as an effective multitarget strategy for the treatment of complex diseases; however, their bioactive constituents are undefined and difficult to identify. In this study, a simple and dual-target method based on ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry combined with dual-bioactive (NF-κB and β(2)-adrenergic receptor) luciferase reporter assay systems was developed for the rapid determination of various bioactive compounds of TCM preparations. Qingfei Xiaoyan Wan, a TCM preparation used for the clinical therapy of asthma, was analyzed with this method. Potential anti-inflammatory and spasmolytic constituents were screened using NF-κB and β(2)-adrenergic receptor activity luciferase reporter assay systems and simultaneously identified according to the time-of-flight mass spectrometry data. One β(2)-adrenergic receptor agonist (ephedrine) and four structural types of NF-κB inhibitors (arctigenin derivatives, cholic acid derivatives, chlorogenic acid, and sinapic acid) were characterized. Tracheloside was considered a new NF-κB inhibitor. Further cytokine and chemokine detection confirmed the anti-inflammatory effects of the potential NF-κB inhibitors. The integration of ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry and dual-bioactive human cell functional evaluation systems proved to be a simple and effective strategy for the rapid screening of various bioactive compounds in TCM preparations used to treat complex diseases.

Studies on the interactions between β2 adrenergic receptor and Gs protein by molecular dynamics simulations

The β2 adrenergic receptor (β2AR) plays a key role in the control of smooth muscle relaxation in airways, the therapy of asthma, and a series of other basic physiological functions. Recently, the crystal structure of the β2AR-Gs protein complex was reported, which facilitates study of the activation mechanism of the β2AR and G-protein-coupled receptors (GPCRs). In this work, we perform 20 ns molecular dynamics (MD) simulations of the β2AR-Gs protein complex with its agonist in an explicit lipid and water environment to investigate the activation mechanism of β2AR. We find that during 20 ns MD simulation with a nanobody bound the interaction between the β2AR and the Gs protein is stable and the whole system is equilibrated within 6 ns. However, without a nanobody stabilizing the complex, the agonist triggers conformational changes of β2AR sequentially from the extracellular region to the intracellular region, especially the intracellular parts of TM3, TM5, TM6, and TM7, which directly interact with the Gs protein. Our results show that the β2AR-Gs protein complex makes conformational changes in the following sequence: (1) an agonist-bound part of β2AR, (2) the intracellular region of β2AR, and (3) the Gs protein.