licochalcone-a and Inflammation

Radix Glycyrrhizae (GL), a herbal medicine that is widely available, has shown advantages for a variety of inflammatory diseases. Toll like receptor 4 (TLR4) pathway has been shown to play a key role in the progression of inflammation.. The purpose of this study was to investigate the involvement of TLR4 in the anti-inflammatory mechanism of GL extract and its active constituent on acute lung injury (ALI).. A model of inflammation produced by lipopolysaccharide (LPS) was established in C57BL/6 mice and macrophages derived from THP-1. To screen the active components of GL, molecular docking was used. Molecular dynamics and surface plasmon resonance imaging (SPRi) were used to study the interaction of a specific drug with the TLR4-MD2 complex. TLR4 was overexpressed by adenovirus to confirm TLR4 involvement in the anti-inflammatory activities of GL and the chosen chemical.. We observed that GL extract significantly reduced both LPS-induced ALI and the production of pro-inflammatory factors including TNF-α, IL-6 and IL-1β. Additionally, GL inhibited the binding of Alexa 488-labeled LPS (LPS-488) to the membrane of THP-1 derived macrophages. GL drastically reduce on the expression of TLR4 and the activation of mitogen-activated protein kinases (MAPKs) and nuclear factor-B (NF-κB). Furthermore, molecular docking revealed that Licochalcone A (LicoA) docked into the LPS binding site of TLR4-MD2 complex. MD2-LicoA binding conformation was found to be stable using molecular dynamic simulations. SPRi indicated that LicoA bound to TLR4-MD2 recombinant protein with a KD of 3.87 × 10. Our findings imply that GL and LicoA exert inhibitory effects on inflammation by targeting the TLR4 directly.

Topics: Acute Lung Injury; Animals; Anti-Inflammatory Agents; Inflammation; Lipopolysaccharides; Lymphocyte Antigen 96; Mice; Mice, Inbred C57BL; Molecular Docking Simulation; NF-kappa B; Toll-Like Receptor 4

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is a challenging clinical syndrome that leads to various respiratory sequelae and even high mortality in patients with severe disease. The novel pharmacological strategies and therapeutic drugs are urgently needed. Natural products have played a fundamental role and provided an abundant pool in drug discovery.. A compound library containing 160 natural products was used to screen potential anti-inflammatory compounds. Mice with LPS-induced ALI was then used to verify the preventive and therapeutic effects of the selected compounds.. Licochalcone A was discovered from the anti-inflammatory screening of natural products in macrophages. A qPCR array validated the inflammation-regulatory effects of licochalcone A and indicated that the potential targets of licochalcone A may be the upstream proteins in LPS pro-inflammatory signalling. Further studies showed that licochalcone A directly binds to myeloid differentiation factor 2 (MD2), an assistant protein of toll-like receptor 4 (TLR4), to block both LPS-induced TRIF- and MYD88-dependent pathways. LEU61 and PHE151 in MD2 protein are the two key residues that contribute to the binding of MD2 to licochalcone A. In vivo, licochalcone A treatment alleviated ALI in LPS-challenged mice through significantly reducing immunocyte infiltration, suppressing activation of TLR4 pathway and inflammatory cytokine induction.. In summary, our study identified MD2 as a direct target of licochalcone A for its anti-inflammatory activity and suggested that licochalcone A might serve as a novel MD2 inhibitor and a potential drug for developing ALI/ARDS therapy.

Topics: Acute Lung Injury; Animals; Anti-Inflammatory Agents; Inflammation; Lipopolysaccharides; Lymphocyte Antigen 96; Mice; Myeloid Differentiation Factor 88; NF-kappa B; Respiratory Distress Syndrome; Toll-Like Receptor 4

Respiratory syncytial virus (RSV) causes lower respiratory tract diseases and bronchiolitis in children and elderly individuals. There are no effective drugs currently available to treat RSV infection. In this study, we report that Licochalcone A (LCA) can inhibit RSV replication and mitigate RSV-induced cell damage in vitro, and that LCA exerts a protective effect by reducing the viral titer and inflammation in the lungs of infected mice in vivo. We suggest that the mechanism of action occurs through pathways of antioxidant stress and inflammation. Further mechanistic results demonstrate that LCA can induce nuclear factor erythroid 2-related factor 2 (Nrf2) translocation into the nucleus, activate heme oxygenase 1 (HO-1), and inhibit reactive oxygen species-induced oxidative stress. LCA also works to reverse the decrease in I-kappa-B-alpha (IкBα) levels caused by RSV, which in turn inhibits inflammation through the associated nuclear factor kappa B and tumor necrosis factor-α signaling pathways. The combined action of the two cross-talking pathways protects hosts from RSV-induced damage. To conclude, our study is the first of its kind to establish evidence of LCA as a viable treatment for RSV infection.

Topics: Animals; Antiviral Agents; Chalcones; Inflammation; Mice; Respiratory Syncytial Virus Infections; Respiratory Syncytial Virus, Human

Immune response plays a vital role in the pathogenesis of neuropathic pain. Immune response-targeted therapy becomes an effective strategy for treating neuropathic pain. Licochalcone A (Lic-A) possesses anti-inflammatory and neuroprotective effects. However, the potential of Lic-A to attenuate neuropathic pain has not been well explored. To investigate the protective effect and evaluate the underlying mechanism of Lic-A against neuropathic pain in a rat model. Chronic constriction injury (CCI) surgery was employed in rats to establish neuropathic pain model. Rats were intraperitoneally administrated with Lic-A (1.25, 2.50 and 5.00 mg/kg) twice daily. Mechanical withdrawal threshold and thermal withdrawal latency were used to evaluate neuropathic pain. After administration, the lumbar spinal cord enlargement of rats was collected for ELISA, Western blot and immunofluorescence analysis. Mechanical withdrawal threshold and thermal withdrawal latency results showed that Lic-A significantly attenuated CCI-evoked neuropathic pain in dose-dependent manner. Lic-A administration also effectively blocked microglia activation. Moreover, Lic-A suppressed p38 phosphorylation and the release of inflammatory factors such as tumor necrosis factor-α, interleukin-1 and interleukin-6. Our findings provide evidence that Lic-A may have the potential to attenuate CCI-evoked neuropathic pain in rats by inhibiting microglia activation and inflammatory response.

Topics: Animals; Calcium-Binding Proteins; Chalcones; Chronic Disease; Constriction, Pathologic; Inflammation; Interleukin-1beta; Interleukin-6; Male; Microfilament Proteins; Microglia; Neuralgia; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Rats, Sprague-Dawley; Sciatic Nerve; Spinal Cord Dorsal Horn; Tumor Necrosis Factor-alpha

The mitogen-activated protein kinase family (MAPK) is an important group of enzymes involved in cellular responses to diverse external stimuli. One of the members of this family is the c-Jun-N-terminal kinase (JNK). The activation of the JNK pathway has been largely associated with the pathogenesis that occurs in epilepsy and neurodegeneration. Kainic acid (KA) administration in rodents is an experimental approach that induces status epilepticus (SE) and replicates many of the phenomenological features of human temporal lobe epilepsy (TLE). Recent studies in our group have evidenced that the absence of the JNK1 gene has neuroprotective effects against the damage induced by KA, as it occurs with the absence of JNK3. The aim of the present study was to analyse whether the pharmacological inhibition of JNK1 by Licochalcone A (Lic-A) had similar effects and if it may be considered as a new molecule for the treatment of SE. In order to achieve this objective, animals were pre-treated with Lic-A and posteriorly administered with KA as a model for TLE. In addition, a comparative study with KA was performed between wild type pre-treated with Lic-A and single knock-out transgenic mice for the Jnk1

Topics: Animals; Anticonvulsants; Cell Survival; Chalcones; Hippocampus; Inflammation; Kainic Acid; Mice, Inbred C57BL; Mice, Knockout; Mitogen-Activated Protein Kinase 8; Neurons; Neuroprotection; Neuroprotective Agents; Oxidative Stress; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-bcl-2; Seizures

Activation of the NACHT, LRR and PYD domains-containing protein 3 (NLRP3) inflammasome by Propionibacterium acnes (P. acnes) is critical for inducing inflammation and aggravating the development of acne lesions. We searched for available small-molecule inhibitors of the NLRP3 inflammasome that could be topically administered for the treatment of acne. We found that licochalcone A, a chalconoid isolated from the root of Glycyrrhiza inflate, was an effective inhibitor for P. acnes-induced NLRP3 inflammasome activation. Licochalcone A blocked P. acnes-induced production of caspase-1(p10) and IL-1β in primary mouse macrophages and human SZ95 sebocytes, indicating the suppression of NLRP3 inflammasome. Licochalcone A suppressed P. acnes-induced ASC speck formation and mitochondrial reactive oxygen species. Topical application of licochalcone A to mouse ear skin attenuated P. acnes-induced skin inflammation as shown by histological assessment, ear thickness measurement, and inflammatory gene expression. Licochalcone A reduced caspase-1 activity and IL-1β production in mouse ear injected with P. acnes. This study demonstrated that licochalcone A is effective in the control of P. acnes-induced skin inflammation as an efficient inhibitor for NLRP3 inflammasome. Our study provides a new paradigm for the development of anti-acne therapy via targeting NLRP3 inflammasome.

Topics: Acne Vulgaris; Animals; Cells, Cultured; Chalcones; Humans; Inflammasomes; Inflammation; Mice; Mice, Inbred C57BL; Microbial Sensitivity Tests; NLR Family, Pyrin Domain-Containing 3 Protein; Propionibacterium acnes; Reactive Oxygen Species; Skin

Direct analysis of prostaglandin-E2 (PGE2) and -D2 (PGD2) produced from a RAW264.7 cell-based reaction was performed by liquid chromatography high-resolution mass spectrometry (LC-HRMS), which was online coupled with turbulent flow chromatography (TFC). The capability of this method to accurately measure PG levels in cell reaction medium containing cytokines or proteins as a reaction byproduct was cross-validated by two conventional methods. Two methods, including an LC-HRMS method after liquid-liquid extraction (LLE) of the sample and a commercial PGE2 enzyme-linked immunosorbent assay (ELISA), showed PGE2 and/or PGD2 levels almost similar to those obtained by TFC LC-HRMS over the reaction time after LPS stimulation. After the cross-validation, significant analytical throughputs, allowing simultaneous screening and potency evaluation of 80 natural products including 60 phytochemicals and 20 natural product extracts for the inhibition of the PGD2 produced in the cell-based inflammatory reaction, were achieved using the TFC LC-HRMS method developed. Among the 60 phytochemicals screened, licochalcone A and formononetin inhibited PGD2 production the most with IC50 values of 126 and 151nM, respectively. For a reference activity, indomethacin and diclofenac were used, measuring IC50 values of 0.64 and 0.21nM, respectively. This method also found a butanol extract of Akebia quinata Decne (AQ) stem as a promising natural product for PGD2 inhibition. Direct and accurate analysis of PGs in the inflammatory cell reaction using the TFC LC-HRMS method developed enables the high-throughput screening and potency evaluation of as many as 320 samples in less than 48h without changing a TFC column.

Topics: Animals; Biological Assay; Biological Products; Chalcones; Chromatography, High Pressure Liquid; Cytokines; Dinoprostone; Enzyme-Linked Immunosorbent Assay; High-Throughput Screening Assays; Indomethacin; Inflammation; Inhibitory Concentration 50; Isoflavones; Liquid-Liquid Extraction; Mass Spectrometry; Mice; Phytochemicals; Prostaglandin D2; RAW 264.7 Cells; Time Factors

 Periodontitis is an inflammatory disease of polymicrobial origin that affects the tooth-supporting tissues. With the spread of antibiotic resistance among pathogenic bacteria, alternative strategies are required to better control infectious diseases such as periodontitis. The aim of our study was to investigate whether two natural compounds, A-type cranberry proanthocyanidins (AC-PACs) and licochalcone A, act in synergy against Porphyromonas gingivalis and the host inflammatory response of a macrophage model..  Using a checkerboard microtitre test, AC-PACs and licochalcone A were found to act in synergy to inhibit P. gingivalis growth and biofilm formation. Fluorescein isothiocyanate-labelled P. gingivalis adhesion to oral epithelial cells was also inhibited by a combination of the two natural compounds in a synergistic manner. Fluorometric assays showed that although AC-PACs and licochalcone A reduced both MMP-9 and P. gingivalis collagenase activities, no synergy was obtained with a combination of the compounds. Lastly, AC-PACs and licochalcone A also acted in synergy to reduce the lipopolysaccharide (LPS)-induced secretion of the pro-inflammatory mediators IL-1β, TNF-α, IL-6 and IL-8 in a macrophage model..  A-type cranberry proanthocyanidins and licochalcone A, natural compounds from cranberry and licorice, respectively, act in synergy on both P. gingivalis and the host immune response, the two principal etiological factors of periodontitis..  The combined use of AC-PACs and licochalcone A may be a potential novel therapeutic strategy for the treatment and prevention of periodontal disease.

Topics: Biofilms; Cell Line; Chalcones; Epithelial Cells; Humans; Inflammation; Interleukin-1beta; Interleukin-6; Interleukin-8; Lipopolysaccharides; Macrophages; Matrix Metalloproteinase 9; Microbial Collagenase; Plant Extracts; Porphyromonas gingivalis; Proanthocyanidins; Tumor Necrosis Factor-alpha; Vaccinium macrocarpon; Virulence

Licochalcone A (LicA), a major phenolic constituent of the licorice species Glycyrrhiza inflata, exhibits various biological properties, including chemopreventive, anti-bacterial, and anti-spasmodic activity. We report that LicA inhibits inflammatory reactions in macrophages and protects mice from endotoxin shock. Our in vitro experiments showed that LicA suppressed not only the generation of nitric oxide (NO) and prostaglandin (PG)E(2), but also the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 induced by lipopolysaccharide (LPS) in RAW264.7 cells. Similarly, LicA inhibited the production of inflammatory cytokines induced by LPS in RAW264.7 cells, including IL-1 beta and IL-6. In an animal model, LicA protected BALB/c mice from LPS-induced endotoxin shock, possibly through inhibiting the production of inflammatory cytokines and NO. Collectively, LicA inhibited the production of inflammatory mediators and may be a potential target for treatment of various inflammatory diseases.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Cell Line; Chalcones; Glycyrrhiza; Inflammation; Inflammation Mediators; Lipopolysaccharides; Mice; NF-kappa B; p38 Mitogen-Activated Protein Kinases; Shock, Septic