Integration of network pharmacology with experimental validation to reveal the mechanism of action of Longdan Xiegan Decoction against HSV2 infection and determine its effective components

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese Medicine (TCM) has made enormous strides recently in the discovery of anti-herpes simplex virus (HSV) drugs under the guidance of TCM theory. Longdan Xiegan Decoction (LXD), a formulation recorded in the Pharmacopoeia of the People's Republic of China, has proved to be effective against HSV infection. However, its effective components and action mechanism remain unclear.

AIM OF THE STUDY

To investigate the effective components and mechanisms of LXD in treating HSV infection based on network pharmacology and experimental validation.

MATERIALS AND METHODS

The anti-HSV activities of key compounds predicted by network analysis were detected by antiviral tests. High-performance liquid chromatography (HPLC) was applied to identify the main components of the LXD aqueous extract. Time-of-addition assay and infectivity inhibition reversibility assay were conducted to identify the potential antiviral mechanisms of licochalcone B (LCB). Additionally, we assessed the antiviral effect of LCB in vivo by use of body weight, viral load, histological analysis, and scoring of genital lesions in an HSV2-infected mouse model.

RESULTS

Our data demonstrated that some components exhibited significant anti-HSV1/2 activity in vitro, including quercetin, kaempferol, wogonin, formononetin, naringenin, baicalein, isorhamnetin, glabridin, licochalcone A, echinatin, oroxylin A, isoliquiritigenin, pinocembrin, LCB and acacetin. HPLC analysis showed that LCB was the main component of LXD aqueous extract. In vitro experiments revealed that LCB not only inactivated HSV2 particles, but also inhibited HSV2 multiplication through the inhibition of the phosphorylation of Akt and its downstream targets. In vivo experiments confirmed that LCB could significantly reduce viral titer, delay weight loss, and alleviate pathological changes in vaginal tissue in vaginal infection mouse models.

CONCLUSION

LCB acted as the main component of LXD, with significant anti-HSV2 infection effects both in vivo and in vitro. This study provides additional evidence of the healing efficacy of LXD against HSV infection and presents an efficient analytical method for further investigation of the mechanisms of TCM in prevention and treatment of various diseases.

Licochalcone A and B enhance muscle proliferation and differentiation by regulating Myostatin

BACKGROUND

Myostatin (MSTN) inhibition has demonstrated promise for the treatment of diseases associated with muscle loss. In a previous study, we discovered that Glycyrrhiza uralensis (G. uralensis) crude water extract (CWE) inhibits MSTN expression while promoting myogenesis. Furthermore, three specific compounds of G. uralensis, namely liquiritigenin, tetrahydroxymethoxychalcone, and Licochalcone B (Lic B), were found to promote myoblast proliferation and differentiation, as well as accelerate the regeneration of injured muscle tissue.

PURPOSE

The purpose of this study was to build on our previous findings on G. uralensis and demonstrate the potential of its two components, Licochalcone A (Lic A) and Lic B, in muscle mass regulation (by inhibiting MSTN), aging and muscle formation.

METHODS

G. uralensis, Lic A, and Lic B were evaluated thoroughly using in silico, in vitro and in vivo approaches. In silico analyses included molecular docking, and dynamics simulations of these compounds with MSTN. Protein-protein docking was carried out for MSTN, as well as for the docked complex of MSTN-Lic with its receptor, activin type IIB receptor (ACVRIIB). Subsequent in vitro studies used C2C12 cell lines and primary mouse muscle stem cells to acess the cell proliferation and differentiation of normal and aged cells, levels of MSTN, Atrogin 1, and MuRF1, and plasma MSTN concentrations, employing techniques such as western blotting, immunohistochemistry, immunocytochemistry, cell proliferation and differentiation assays, and real-time RT-PCR. Furthermore, in vivo experiments using mouse models focused on measuring muscle fiber diameters.

RESULTS

CWE of G. uralensis and two of its components, namely Lic A and B, promote myoblast proliferation and differentiation by inhibiting MSTN and reducing Atrogin1 and MuRF1 expressions and MSTN protein concentration in serum. In silico interaction analysis revealed that Lic A (binding energy -6.9 Kcal/mol) and B (binding energy -5.9 Kcal/mol) bind to MSTN and reduce binding between it and ACVRIIB, thereby inhibiting downstream signaling. The experimental analysis, which involved both in vitro and in vivo studies, demonstrated that the levels of MSTN, Atrogin 1, and MuRF1 were decreased when G. uralensis CWE, Lic A, or Lic B were administered into mice or treated in the mouse primary muscle satellite cells (MSCs) and C2C12 myoblasts. The diameters of muscle fibers increased in orally treated mice, and the differentiation and proliferation of C2C12 cells were enhanced. G. uralensis CWE, Lic A, and Lic B also promoted cell proliferation in aged cells, suggesting that they may have anti-muslce aging properties. They also reduced the expression and phosphorylation of SMAD2 and SMAD3 (MSTN downstream effectors), adding to the evidence that MSTN is inhibited.

CONCLUSION

These findings suggest that CWE and its active constituents Lic A and Lic B have anti-mauscle aging potential. They also have the potential to be used as natural inhibitors of MSTN and as therapeutic options for disorders associated with muscle atrophy.

LicochalconeB inhibits cGAS-STING signaling pathway and prevents autoimmunity diseases

Cytosolic DNA activates the STING (stimulator of interferon genes) signaling pathway to trigger interferon and inflammatory responses that protect against microbial infections and cancer. However, Aicardi-Goutières syndrome (AGS) persistently activates the STING signaling pathway, which can lead to severe autoimmune diseases. We demonstrate herein that Licochalcone B (LicoB), the main component of traditional licorice, is an inhibitor of the STING signaling pathway. We observed that LicoB inhibited the activation of the STING signaling pathway in macrophages. Mechanically, LicoB affected the STING-TBK1-IRF3 signal axis and inhibited the activation of the STING downstream signaling pathway. Furthermore, LicoB inhibited the increase in type I interferon levels in mice induced by the STING agonist CMA. LicoB significantly reduced systemic inflammation in Trex1-/- mice. Our results show that LicoB, a STING signaling pathway inhibitor, is a promising candidate for the treatment of diseases related to STING signaling pathway activation.

Licochalcone B confers protective effects against LPS-Induced acute lung injury in cells and mice through the Keap1/Nrf2 pathway

BACKGROUND

Acute lung injury (ALI) is a severe and often fatal pulmonary disease. Current treatments for ALI and acute respiratory distress syndrome (ARDS) are limited. Natural product metabolites have shown promise as therapeutic alternatives. However, the effects of Licochalcone B (LCB) on ALI are largely unknown.

METHODS

We investigated the effects of LCB on lipopolysaccharide-challenged mice and human pulmonary microvascular endothelial cells. Cell viability, apoptosis, and ROS production were assessed. Lung tissue histopathology and oxidative stress and inflammation markers were evaluated. Protein expression levels were measured.

RESULTS

LCB had no cytotoxic effects on cells and increased cell viability. It reduced apoptosis and ROS levels in cells. In mice with ALI, LCB decreased lung tissue weight and improved oxidative stress and inflammation markers. It also enhanced expression levels of Nrf2, HO-1, and NQO1 while reducing Keap1.

CONCLUSION

LCB protects against LPS-induced acute lung injury in cells and mice. The Keap1/Nrf2 pathway may be involved in its protective effects. LCB shows potential as a strategy to alleviate ALI caused by LPS.

Study on molecular mechanisms of destabilizing Aβ(1-42) protofibrils by licochalcone A and licochalcone B using molecular dynamics simulations

Amyloid-beta (Aβ) protofibrils are closely related to Alzheimer's disease. Their behaviors with or without the presence of Aβ fibrillization inhibitors have been intensively studied by molecular dynamics simulations. In this work, the molecular mechanisms of licochalcone A and licochalcone B on destabilizing Aβ(1-42) protofibrils are explored. It is found that both two licochalcones can disorder the configuration of the Aβ(1-42) protofibril. The stable interactions between the Aβ(1-42) protofibril and licochalcone A or licochalcone B are able to be formed. A reduction of the β-sheet structure contents and an increment of the random coil structures of Aβ(1-42) protofibril are observed in the presence of either licochalcone A or licochalcone B. The hydrogen bonds inside the Aβ(1-42) protofibril could be partially collapsed to varying degrees by two licochalcones. Furthermore, the van der Waals interactions between Aβ(1-42) protofibril and licochalcone A make an important contribution to the binding free energy, while the contribution of the electrostatic interactions between Aβ(1-42) protofibril and licochalcone B is more prominent in the binding affinity. Our work may help in the development of new drug candidates for disrupting the Aβ protofibril.

Licochalcone B specifically inhibits the NLRP3 inflammasome by disrupting NEK7-NLRP3 interaction

The activation of the nucleotide oligomerization domain (NOD)-like receptor (NLR) family, pyrin domain-containing protein 3 (NLRP3) inflammasome is related to the pathogenesis of a wide range of inflammatory diseases, but drugs targeting the NLRP3 inflammasome are still scarce. In the present study, we demonstrated that Licochalcone B (LicoB), a main component of the traditional medicinal herb licorice, is a specific inhibitor of the NLRP3 inflammasome. LicoB inhibits the activation of the NLRP3 inflammasome in macrophages but has no effect on the activation of AIM2 or NLRC4 inflammasome. Mechanistically, LicoB directly binds to NEK7 and inhibits the interaction between NLRP3 and NEK7, thus suppressing NLRP3 inflammasome activation. Furthermore, LicoB exhibits protective effects in mouse models of NLRP3 inflammasome-mediated diseases, including lipopolysaccharide (LPS)-induced septic shock, MSU-induced peritonitis and non-alcoholic steatohepatitis (NASH). Our findings indicate that LicoB is a specific NLRP3 inhibitor and a promising candidate for treating NLRP3 inflammasome-related diseases.

Licochalcone B attenuates neuronal injury through anti-oxidant effect and enhancement of Nrf2 pathway in MCAO rat model of stroke

BACKGROUND

Investigating anti-oxidant therapies that lead to the diminution of oxidative injury is priority in clinical. We herein aimed to explore whether and how Licochalcone B (Lico B) act as an anti-oxidant in the stroke model.

METHODS

Middle cerebral artery occlusion (MCAO) was constructed as stroke model and exposed to various doses of Lico B. Behavioral tests and neurological behavior status were detected for neurological function examination. Histological staining was used for evaluating cerebral injury, and neuronal apoptosis or damage. Levels of oxidative stress and inflammation were also assessed by biochemical analysis and expression analysis. Nrf2 knockdown induced by lentiviral vector was used for the research on mechanism.

RESULTS

Lico B had improvement effects on cerebral infarction size, memory impairments, and neurological deficits after MCAO. Histological evaluation also revealed the amelioration of neuronal injury and apoptosis by Lico B, along with down-regulation of apoptosis-related proteins. Additionally, Lico B rescued the down-regulation of BDNF and NGF after MCAO. Moreover, Lico B suppressed the oxidative stress and inflammation, manifesting as the enhancement of SOD, GSH and IL-4, but the decline of MDA, iNOS, and TNF-α. Finally, Nrf2 knockdown reversed the Lico B-caused improvement in neuronal injury, apoptosis and oxidative stress levels.

CONCLUSIONS

The present study revealed the neuroprotective effects of Lico B in MCAO rats. Importantly, we proposed a potential mechanism that Lico B activated the Nrf2 pathway, thereby acting as anti-oxidant to attenuate neuronal injury and apoptosis after stroke. The proposed mechanism provided an encouraging possibility for anti-oxidant therapy of stroke.

Integrated miRNA and mRNA omics reveal the anti-cancerous mechanism of Licochalcone B on Human Hepatoma Cell HepG2

To unravel the potential of Licochalcone B as an anti-tumour phytochemical agent and evaluate its underlying mechanisms, we analyzed the mRNAs and miRNAs expression profiles of HepG2 cells in response to Licochalcone B (120 μM). mRNA and miRNA expression libraries were conducted and functional analysis for differential expression mRNAs was carried out utilizing Clue GO. We found 763 Licochalcone B -responsive differently expressed genes, among them, 572 mRNAs were up-regulated and 191 mRNAs were down-regulated, many of which were related to the MAPK signaling pathway. A protein-protein interaction network was constructed to discover the hub genes, and IL6, FOS, JUN, NOTCH1, UBC, UBB, CXCL8, CDKN1A, IL1B, ATF3, and GATA3 genes were screened out. Additionally, miRNAs engaged in Licochalcone B -mediated regulation on HepG2 cells were also studied. 85 differential expression miRNAs were identified, including 39 up-regulated miRNAs and 46 down-regulated miRNAs. Co-expression of miRNA-mRNA network was created and two key miRNAs (hsa-miR-29b-3p and hsa-miR-96-5p) were identified. These recognized key genes, miRNA, and the miRNA-mRNA regulatory network may provide clues to understand the molecular mechanism of Licochalcone B as an apoptotic inducer which may offer hint for its application as a functional food component.

Janus kinase 2 inhibition by Licochalcone B suppresses esophageal squamous cell carcinoma growth

Esophageal cancer (EC) is one of the leading causes to cancer death in the worldwide and major population of EC is esophageal squamous cell carcinoma (ESCC). Still, ESCC-targeted therapy has not been covered yet. In the present study we have identified that Licochalcone B (Lico B) inhibited the ESCC growth by directly blocking the Janus kinase (JAK) 2 activity and its downstream signaling pathway. Lico B suppressed KYSE450 and KYSE510 ESCC cell growth, arrested cell cycle at G2/M phase and induced apoptosis. Direct target of Lico B was identified by kinase assay and verified with in vitro and ex vivo binding. Computational docking model predicted for Lico B interaction to ATP-binding pocket of JAK2. Furthermore, treatment of JAK2 clinical medicine AZD1480 to ESCC cells showed similar tendency with Lico B. Thus, JAK2 downstream signaling proteins phosphorylation of STAT3 at Y705 and S727 as well as STAT3 target protein Mcl-1 expression was decreased with treatment of Lico B. Our results suggest that Lico B inhibits ESCC cell growth, arrests cell cycle and induces apoptosis, revealing the underlying mechanism involved in JAK2/STAT3 signaling pathways after Lico B treatment. It might provide potential role of Lico B in the treatment of ESCC.

Licochalcone B Ameliorates Liver Cancer via Targeting of Apoptotic Genes, DNA Repair Systems, and Cell Cycle Control

Apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) is a ubiquitous multifunctional protein required in the DNA base excision repair pathway and a noteworthy reducing-oxidizing factor that regulates the activity of various transcription factors. Cyclin-dependent kinases (CDKs) assume a key role in directing the progression of the cell- cycle. The present study evaluated the synergistic efficacy of using licochalcone B (LCB) and fullerene C60 (FnC60) nanoparticles against diethylnitrosamine (DEN)-induced hepatocarcinoma in rats and relevant signaling pathways, with APE1/Ref-1 and CDK-4, as novel anti-cancer- targeting. LCB alone and in combination with FnC60 significantly decreased DNA fragmentation, oxidative DNA damage (8-hydroxy-2'-deoxyguanosine levels), APE1/Ref-1, CDK-4, retinoblastoma, B- cell lymphoma-2 (Bcl-2), B-cell lymphoma-xL (Bcl-xL), and β-arrestin-2 mRNA expression, and APE1/Ref-1 and CDK-4 protein expression. In contrast, these treatments significantly increased the expression of protein 53 (p53), Bcl-2-associated X protein (Bax), and caspase-3. These data suggest that LCB either alone or in combination with FnC60 elicited significant protective effects against DEN-induced hepatocarcinogenesis, which may have occurred because of the regulation of enzymes involved in DNA repair and cell-cycle control at S phase progression as well as the induction of apoptosis at the gene and protein expression levels. Furthermore, FnC60 potentiated the effect of LCB at the molecular level, possibly through targeting of cancerous cells.

Licochalcone B inhibits growth and induces apoptosis of human non-small-cell lung cancer cells by dual targeting of EGFR and MET

BACKGROUND

Epidermal growth factor receptor (EGFR) gene alterations are associated with sensitization to tyrosine kinase inhibitors such as gefitinib in lung cancer. Some patients suffering from non-small cell lung cancer (NSCLC) have difficulty in treating the cancer due to resistance acquired to gefitinib with MET amplification. Therefore EGFR and MET may be attractive targets for lung cancer therapy.

PURPOSE

This study aimed to investigate the anti-cancer activity of Licochalcone (LC)B extracted from Glycyrrhiza inflata, in gefitinib-sensitive or gefitinib-resistant NSCLC cells, and to define its mechanisms.

STUDY DESIGN

We investigated the mechanism of action of LCB by targeting EGFR and MET in human NSCLC cells.

METHODS

We used the HCC827 and HCC827GR lines as gefitinib-sensitive and -resistant cells respectively, and determined the effects of LCB on both, by performing cell proliferation assay, flow cytometry analysis and Western blotting. Targets of LCB were identified by pull-down/kinase assay and molecular docking simulation.

RESULTS

LCB inhibited both EGFR and MET kinase activity by directly binding to their ATP-binding pockets. The ability of this interaction was verified by computational docking and molecular dynamics simulations. LCB suppressed viability and colony formation of both HCC827 and HCC827GR cells while exhibiting no cytotoxicity to normal cells. The induction of G2/M cell-cycle arrest and apoptosis by LCB was confirmed by Annexin V/7-AAD double staining, ER stress and reactive oxygen species induction, mitochondrial membrane potential loss and caspase activation as well as related-proteins regulation. Inhibition of EGFR and MET by LCB decreased ERBB3 and AKT axis activation.

CONCLUSION

We provide insights into the LCB-mediated mechanisms involved in reducing cell proliferation and inducing apoptosis in NSCLC cells. This occurs through dual inhibition of EGFR and MET in NSCLC cells regardless of their sensitivity or resistance to gefitinib. LCB may be a promising novel therapeutic medicine for gefitinib-sensitive or resistant NSCLC treatment.

Hepatoprotective effects of licochalcone B on carbon tetrachloride-induced liver toxicity in mice

OBJECTIVES

The objective of this study was to investigate the hepatoprotective effect of licochalcone B (LCB) in a mice model of carbon tetrachloride (CCl₄)-induced liver toxicity.

MATERIALS AND METHODS

Hepatotoxicity was induced in mice by a single subcutaneous injection (SC) of CCl4. The LCB was administered orally once a day for seven days (PO) as pretreatment at three doses of 1, 5, and 25 mg/kg/day. The levels of superoxide dismutase (SOD), malondialdehyde (MDA), glutathione (GSH), glutathione disulfide (GSSG), C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were analyzed by ELISA. The protein expression degrees of p38 mitogen activated protein kinases (p38) and nuclear factor-k-gene binding (NF-κB) were assayed by western blotting.

RESULTS

CCl4-induced hepatotoxicity was manifested by an increase in the levels of ALT, AST, MDA, IL-6, CRP, and TNF-ɑ, and a decrease in the SOD level and GSH/GSSG ratio in the serum. The histopathological examination of the liver sections revealed necrosis and inflammatory reactions. Pretreatment with LCB decreased the levels of ALT, AST, MDA, GSSG, IL-6, CRP, TNF-ɑ, and the protein expression of p38 and NF-κB, increased the level of SOD and GSH, and normalized the hepatic histo-architecture.

CONCLUSION

LCB protected the liver from CCl4-induced injury. Protection may be due to inhibition of p38 and NFκB signaling, which subsequently reduced inflammation in the liver.

Licochalcone B inhibits growth of bladder cancer cells by arresting cell cycle progression and inducing apoptosis

To examine the mechanisms by which licochalcone B (LCB) inhibits the proliferation of human malignant bladder cancer cell lines (T24 and EJ) in vitro and antitumor activity in vivo in MB49 (murine bladder cancer cell line) tumor model. Exposure of T24 or EJ cells to LCB significantly inhibited cell lines proliferation in a concentration-dependent and time-dependent manner, and resulted in S phase arrest in T24 or EJ cells, respectively. LCB treatment decreased the expression of cyclin A, cyclin-dependent kinase (CDK1 and CDK2) mRNA, cell division cycle 25 (Cdc25A and Cdc25B) protein. In addition, LCB treatment down-regulated Bcl-2 and survivin expression, enhanced Bax expression, activated caspase-3 and cleaved poly (ADP-ribose) polymerase (PARP) protein. Consistently, the tumorigenicity of LCB-treated MB49 cells was limited significantly by using the colony formation assay in vitro and the MB49 tumor model performed in C57BL/6 mice in vivo. These findings provide support for the use of LCB in chemoprevention and bladder cancer therapy.