A new synthetic chalcone derivative, 2-hydroxy-3',5,5'-trimethoxychalcone (DK-139), suppresses the Toll-like receptor 4-mediated inflammatory response through inhibition of the Akt/NF-κB pathway in BV2 microglial cells

A Promising Drug Candidate as Potent Therapeutic Approach for Neuroinflammation and Its In Silico Justification of Chalcone Congeners: a Comprehensive Review

Multiple genetic, environmental, and immunological variables cause neuropsychiatric disorders (NPDs). The induced inflammatory immune response is also connected to the severity and treatment outcomes of various NPDs. These reactions also significantly impact numerous brain functions such as GABAergic signaling and neurotransmitter synthesis through inflammatory cytokines and chemokines. Chalcones (1,3-diaryl-2-propen-1-ones) and their heterocyclic counterparts are flavonoids with various biological characteristics including anti-inflammatory activity. Several pure chalcones have been clinically authorized or studied in humans. Chalcones are favored for their diagnostic and therapeutic efficacy in neuroinflammation due to their tiny molecular size, easy manufacturing, and flexibility for changes to adjust lipophilicity ideal for BBB penetrability. These compounds reached an acceptable plasma concentration and were well-tolerated in clinical testing. As a result, they are attracting increasing attention from scientists. However, chalcones' therapeutic potential remains largely untapped. This paper is aimed at highlighting the causes of neuroinflammation, more potent chalcone congeners, their mechanisms of action, and relevant structure-activity relationships.

Flavonoid diversity and roles in the lipopolysaccharide-mediated inflammatory response of monocytes and macrophages

Targeting lipopolysaccharide (LPS)/toll-like receptor 4 signaling in mononuclear phagocytes has been explored for the treatment of inflammation and inflammation-related disorders. However, only a few key targets have been translated into clinical applications. Flavonoids, a class of ubiquitous plant secondary metabolites, possess a privileged scaffold which serves as a valuable template for designing pharmacologically active compounds directed against diseases with inflammatory components. This perspective provides a general overview of the diversity of flavonoids and their multifaceted mechanisms that interfere with LPS-induced signaling in monocytes and macrophages. Focus is placed on flavonoids targeting MD-2, IκB kinases, c-Jun N-terminal kinases, extracellular signal-regulated kinase, p38 MAPK and PI3K/Akt or modulating LPS-related gene expression.

Evaluation of chalcone derivatives for their role as antiparasitic and neuroprotectant in experimentally induced cerebral malaria mouse model

Cerebral malaria is a severe complication of Plasmodium falciparum infection with a complex pathophysiology. The current course of treatment is ineffective in lowering mortality or post-treatment side effects such as neurological and cognitive abnormalities. Chalcones are enormously distributed in spices, fruits, vegetables, tea, and soy-based foodstuffs that are well known for their antimalarial activity, and in recent years they have been widely explored for brain diseases like Alzheimer's disease. Therefore, considering the previous background of chalcones serving as both antimalarial and neuroprotective, the present study aimed to study the effect of these chalcone derivatives on an experimental model of cerebral malaria (CM). CM-induced mice were tested behaviorally (elevated plus maze, rota rod test, and hanging wire test), biochemically (nitric oxide estimation, cytokines (IL-1, IL-6, IL-10, IL-12p70, TNF, IFN-y), histopathologically and immunohistochemically, and finally ultrastructural changes were examined using a transmission electron microscope. All three chalcones treated groups showed a significant (p < 0.001) decrease in percentage parasitemia at the 10th day post-infection. Mild anxiolytic activity of chalcones as compared to standard treatment with quinine has been observed during behavior tests. No pigment deposition was observed in the QNN-T group and other chalcone derivative treated groups. Rosette formation was seen in the derivative 1 treated group. The present derivatives may be pioneered by various research and science groups to design such a scaffold that will be a future antimalarial with therapeutic potential or, because of its immunomodulatory properties, it could be used as an adjunct therapy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03676-y.

Hydroxy Chalcones and Analogs with Chemopreventive Properties

The aim of this review is to highlight the chemopreventive properties of hydroxy-substituted natural and synthetic chalcones along with a number of their analogs. These products display various biological activities, and have many applications against various diseases. Antioxidant and anti-inflammatory properties of chalcones bearing hydroxy substituents are underlined. The influence of hydroxy substituents located on ring A, B, or both are systematized according to the exhibited biological properties.

Sodium-glucose cotransporter 2 inhibitor ameliorates high fat diet-induced hypothalamic-pituitary-ovarian axis disorders

High-fat diet (HFD) consumption is known to be associated with ovulatory disorders among women of reproductive age. Previous studies in animal models suggest that HFD-induced microglia activation contributes to hypothalamic inflammation. This causes the dysfunction of the hypothalamic-pituitary-ovarian (HPO) axis, leading to subfertility. Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a novel class of lipid-soluble antidiabetic drugs that target primarily the early proximal tubules in kidney. Recent evidence revealed an additional expression site of SGLT2 in the central nervous system (CNS), indicating a promising role of SGLT2 inhibitors in the CNS. In type 2 diabetes patients and rodent models, SGLT2 inhibitors exhibit neuroprotective properties through reduction of oxidative stress, alleviation of cerebral atherosclerosis and suppression of microglia-induced neuroinflammation. Furthermore, clinical observations in patients with polycystic ovary syndrome (PCOS) demonstrated that SGLT2 inhibitors ameliorated patient anthropometric parameters, body composition and insulin resistance. Therefore, it is of importance to explore the central mechanism of SGLT2 inhibitors in the recovery of reproductive function in patients with PCOS and obesity. Here, we review the hypothalamic inflammatory mechanisms of HFD-induced microglial activation, with a focus on the clinical utility and possible mechanism of SGLT2 inhibitors in promoting reproductive fitness.

Involvement of Anti-Inflammatory and Stress Oxidative Markers in the Antidepressant-like Activity of Aloysia citriodora and Verbascoside on Mice with Bacterial Lipopolysaccharide- (LPS-) Induced Depression

Aloysia citriodora Palau is popularly used to treat nervous disorders. Experimental evidence has indicated that verbascoside (VBS) isolated from A. citriodora has pharmacological potential. In this study, we evaluated the antidepressant-like effects of a hydroalcoholic extract of A. citriodora (HEAc) and VBS against lipopolysaccharide- (LPS-) induced depressive-like behavior in mice. In the pretreatment protocol (performed to evaluate the preventive potential), mice were pretreated with HEAc (3, 30, or 300 mg/kg) or VBS (30 mg/kg) before the administration of LPS. In the posttreatment protocol (performed to evaluate the therapeutic potential), mice were initially administered LPS and were subsequently given HEAc (3, 30, or 300 mg/kg) or VBS (30 mg/kg). In both treatments, the mice were submitted to an open-field test and tail suspension test (TST) at 6 and 24 h after LPS administration. The posttreatment evaluation revealed that HEAc (30 or 300 mg/kg) and VBS produced an antidepressant-like effect, as indicated by a reduction in the time spent with no movement in the TST. Moreover, HEAc (30 or 300 mg/kg) was found to reduce interleukin-6 (IL-6) levels and N-acetyl-glycosaminidase activity in the hippocampus, increase glutathione (GSH) levels in the hippocampus and cortex, and enhance IL-10 in the cortex and, at a dose of 300 mg/kg, reduced myeloperoxidase activity in the cortex. Contrastingly, no comparable effects were detected in mice subjected to the pretreatment protocol. Administration of VBS similarly reduced the levels of IL-6 in the hippocampus and increased GSH levels in the cortex. Our observations indicate that both HEAc and VBS show promising antidepressant-like potential, which could be attributed to their beneficial effects in reducing neuroinflammatory processes and antioxidant effects in the central nervous system.

Synthesis and in vitro studies for structure-based design of novel chalcones as antitubercular agents targeting InhA

Background: The authors aimed to estimate the therapeutic potential of novel chalcones against tuberculosis. Methods: 11 synthesized compounds were tested for in vitro antimycobacterial activity against Mycobacterium tuberculosis (H37RV; American Type Culture Collection number: 27294) using the microplate alamarBlue assay. Molecular docking and pharmacokinetic parameter analyses were then performed. Results: The most potent compounds, (2E)-1-(4-bromophenyl) (2E)-1-(2-nitrophenyl) prop-2-en-1-one, -3-(2-nitrophenyl) prop-2-en-1-one (4-bromophenyl) (2E)-1-(3-phenoxyphenyl)prop-2-en-1-one, 3-(phenoxyphenyl)prop-2-en-1-one (4-bromophenyl) prop-2-en-1-one and (2E)-1-(4-bromophenyl)-3-(5-chloro-2-hydroxyphenyl)-prop-2-en-1-one, showed in vitro activity, with a minimum inhibitory concentration (MIC) of 6.25 μg/ml. Conclusion: Compounds LSD2, LSD12, LSD13 and LSD15 showed strong in vitro antimycobacterial activity at a concentration of 6.25 μg/ml.

Anti-neuroinflammatory activity of 6,7-dihydroxy-2,4-dimethoxy phenanthrene isolated from Dioscorea batatas Decne partly through suppressing the p38 MAPK/NF-κB pathway in BV2 microglial cells

ETHNOPHARMACOLOGICAL RELEVANCE

The rhizome of Dioscorea batatas Decne (called Chinses yam) widely distributed in East Asian countries including China, Japan, Korea and Taiwan has long been used in oriental folk medicine owing to its tonic, antitussive, expectorant and anti-ulcerative effects. It has been reported to have anti-inflammatory, antioxidative, cholesterol-lowering, anticholinesterase, growth hormone-releasing, antifungal and immune cell-stimulating activities.

AIM OF THE STUDY

Neuroinflammation caused by activated microglia contributes to neuronal dysfunction and neurodegeneration. In the present study, the anti-neuroinflammatory activity of 6,7-dihydroxy-2,4-dimethoxy phenanthrene (DHDMP), a phenanthrene compound isolated from Dioscorea batatas Decne, was examined in microglial and neuronal cells.

MATERIALS AND METHODS

A natural phenanthrene compound, DHDMP, was isolated from the peel of Dioscorea batatas Decne. The anti-neuroinflammatory capability of the compound was examined using the co-culture system of BV2 murine microglial and HT22 murine neuronal cell lines. The expression levels of inflammatory mediators and cytoprotective proteins in the cells were quantified by enzyme-linked immunosorbent assay and Western blot analysis.

RESULTS

DHDMP at the concentrations of ≤1 μg/mL did not exhibit a cytotoxic effect for BV2 and HT22 cells. Rather DHDMP effectively restored the growth rate of HT22 cells, which was reduced by co-culture with lipopolysaccharide (LPS)-treated BV2 cells. DHDMP significantly decreased the production of proinflammatory mediators, such as nitric oxide, tumor necrosis factor-α, interleukin-6, inducible nitric oxide synthase, and cyclooxygenase-2 in BV2 cells. Moreover, DHDMP strongly inhibited the nuclear translocation of nuclear factor κB (NF-κB) and phosphorylation of p38 mitogen-activated protein kinase (MAPK) in BV2 cells. The compound did not affect the levels and phosphorylation of ERK and JNK. Concurrently, DHDMP increased the expression of heme oxygenase-1 (HO-1), an inducible cytoprotective enzyme, in HT22 cells.

CONCLUSIONS

Our findings indicate that DHDMP effectively dampened LPS-mediated inflammatory responses in BV2 microglial cells by suppressing transcriptional activity of NF-κB and its downstream mediators and contributed to HT22 neuronal cell survival. This study provides insight into the therapeutic potential of DHDMP for inflammation-related neurological diseases.

Antioxidant, antimicrobial, and molecular docking studies of novel chalcones and Schiff bases bearing 1, 4-naphthoquinone moiety

Background:

The 1,4-naphthoquinone ring has attracted prominent interest in the field of medicinal chemistry due to its potent pharmacological activity as antioxidant, antibacterial, antifungal, and anticancer.

Objective:

Herein, a series of new Schiff bases (4-6) and chalcones (8a-c & 9a-d) bearing 1,4-naphthoquinone moiety were synthesized in good yields and were subjected to in-vitro antimicrobial, antioxidant, and molecular docking testing.

Methods:

A facile protocol has been described in this study for the synthesis of new derivatives (4-7, 8a-c, and 9a-d) bearing 1,4-naphthoquinone moiety. The chemical structures of all the synthesized compounds were identified by 1H-NMR, 13C-NMR, MS, and elemental analyses. Moreover, these derivatives were assessed for their in-vitro antimicrobial activity against gram-positive, gram-negative bacteria, and fungal strains. Further studies were conducted to test their antioxidant activity using DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging assay. Molecular docking studies were realized to identify the most likely interactions of the novel compounds within the protein receptor.

Results:

The antimicrobial results showed that most of the compounds displayed good efficacy against both bacterial and fungal strains. The antioxidant study revealed that compounds 9d, 9a, 9b, 8c, and 6 exhibited the highest radical scavenging activity. Docking studies of the most active antimicrobial compounds within GLN- 6-P, recorded good scores with several binding interactions with the active sites.

Conclusion:

Based on the obtained results, it was found that compounds 8b, 9b, and 9c displayed the highest activity against both bacterial and fungal strains. The obtained findings from the DPPH radical scavenging method revealed that compounds 9d and 9a exhibited the strongest scavenging potential. The molecular docking studies proved that the most active antimicrobial compounds 8b, 9b and 9c displayed the highest energy binding scores within the glucosamine-6-phosphate synthase (GlcN-6-P) active site.

Chalcones: Synthetic Chemistry Follows Where Nature Leads

Chalcones belong to the flavonoid class of phenolic compounds. They form one of the largest groups of bioactive natural products. The potential anticancer, anti-inflammatory, antimicrobial, antioxidant, and antiparasitic properties of naturally occurring chalcones, and their unique chemical structural features inspired the synthesis of numerous chalcone derivatives. In fact, structural features of chalcones are easy to construct from simple aromatic compounds, and it is convenient to perform structural modifications to generate functionalized chalcone derivatives. Many of these synthetic analogs were shown to possess similar bioactivities as their natural counterparts, but often with an enhanced potency and reduced toxicity. This review article aims to demonstrate how bioinspired synthesis of chalcone derivatives can potentially introduce a new chemical space for exploitation for new drug discovery, justifying the title of this article. However, the focus remains on critical appraisal of synthesized chalcones and their derivatives for their bioactivities, linking to their interactions at the biomolecular level where appropriate, and revealing their possible mechanisms of action.

Chalcone Derivatives: Role in Anticancer Therapy

Chalcones (1,3-diaryl-2-propen-1-ones) are precursors for flavonoids and isoflavonoids, which are common simple chemical scaffolds found in many naturally occurring compounds. Many chalcone derivatives were also prepared due to their convenient synthesis. Chalcones as weandhetic analogues have attracted much interest due to their broad biological activities with clinical potentials against various diseases, particularly for antitumor activity. The chalcone family has demonstrated potential in vitro and in vivo activity against cancers via multiple mechanisms, including cell cycle disruption, autophagy regulation, apoptosis induction, and immunomodulatory and inflammatory mediators. It represents a promising strategy to develop chalcones as novel anticancer agents. In addition, the combination of chalcones and other therapies is expected to be an effective way to improve anticancer therapeutic efficacy. However, despite the encouraging results for their response to cancers observed in clinical studies, a full description of toxicity is required for their clinical use as safe drugs for the treatment of cancer. In this review, we will summarize the recent advances of the chalcone family as potential anticancer agents and the mechanisms of action. Besides, future applications and scope of the chalcone family toward the treatment and prevention of cancer are brought out.

Chalcone and its analogs: Therapeutic and diagnostic applications in Alzheimer's disease

Chalcone [(E)-1,3-diphenyl-2-propene-1-one], a small molecule with α, β unsaturated carbonyl group is a precursor or component of many natural flavonoids and isoflavonoids. It is one of the privileged structures in medicinal chemistry. It possesses a wide range of biological activities encouraging many medicinal chemists to study this scaffold for its usefulness to oncology, infectious diseases, virology and neurodegenerative diseases including Alzheimer's disease (AD). Small molecular size, convenient and cost-effective synthesis, and flexibility for modifications to modulate lipophilicity suitable for blood brain barrier (BBB) permeability make chalcones a preferred candidate for their therapeutic and diagnostic potential in AD. This review summarizes and highlights the importance of chalcone and its analogs as single target small therapeutic agents, multi-target directed ligands (MTDLs) as well as molecular imaging agents for AD. The information summarized here will guide many medicinal chemist and researchers involved in drug discovery to consider chalcone as a potential scaffold for the development of anti-AD agents including theranostics.

Discovery and Development of Inflammatory Inhibitors from 2-Phenylchromonone (Flavone) Scaffolds

Flavonoids are compounds based on a 2-phenylchromonone scaffold. Flavonoids can be divided into flavonoids, flavonols, dihydroflavones, anthocyanins, chalcones and diflavones according to the oxidation degree of the central tricarbonyl chain, the connection position of B-ring (2-or 3-position), and whether the tricarbonyl chain forms a ring or not. There are a variety of biological activities about flavonoids, such as anti-inflammatory activity, anti-oxidation and anti-tumor activity, and the antiinflammatory activity is apparent. This paper reviews the anti-inflammatory activities and mechanisms of flavonoids and their derivatives reported in China and abroad from 2011 till date (2011-2020), in order to find a good drug scaffold for the study of anti-inflammatory activities.

Neuroprotective effects of natural compounds on LPS-induced inflammatory responses in microglia

Neuroinflammation is one of the main mechanisms involved in the progression of neurodegeneration. The activation of microglia is the main feature of neuroinflammation, promoting the release of neurotoxic molecules and pro-inflammatory cytokines and resulting in the progressive neuronal cell death. Thus, suppression of the over-activation of microglia using novel pharmacological agents is an attractive issue to alleviate the neuroinflammatory processes associated with neurodegeneration. In recent years, medicinal plants-derived natural compounds have received extensive attention as useful sources of new neuroprotective agents for treating neurological disorders. In this review, we summarized the detailed research progress on the natural compounds derived from medicinal plants with potential anti-inflammatory effects and their molecular mechanisms on modulating the LPS-induced inflammatory responses in microglia. The natural compounds that efficacious in inhibiting the microglia activation include flavonoids, glycosides, phenolics, terpenoids, quinones, alkaloids, lignans, coumarins, chalcone, stilbene and others (biphenyl, phenylpropanoid, oxy carotenoid). They can reduce the expression of neurotoxic mediators (NO, PGE2, iNOS, COX-2) and pro-inflammatory cytokines (IL-6, TNF-α, IL-1β), down-regulate inflammatory markers and prevent neural damage. They exert anti-neuroinflammatory effects by modulating relevant signaling pathways (NF-κB, MAPKs, Nrf2/HO-1, PI3K/Akt, JAK/STAT) as demonstrated by experimental data. The present work reviews the role of microglia activation in neuroinflammation, highlighting the potential anti-inflammatory effects of natural compounds as a promising approach to develop innovative neuroprotective strategy.

Mn-TAT PTD-Ngb ameliorates inflammation through the elimination of damaged mitochondria and the activation of Nrf2-antioxidant signaling pathway

Inflammation, mitochondrial dysfunction and oxidative stress are closely associated with neurological diseases. In this study, Mn-TAT PTD-Ngb, a novel artificial recombinant protein, exerted inhibitory effects on the inflammatory response and inflammasome activation. During the lipopolysaccharide (LPS)-induced inflammatory response, Mn-TAT PTD-Ngb suppressed the nuclear translocation of nuclear factor kappa B (NF-κB) and the release of proinflammatory cytokines and attenuated the phosphorylation of mitogen-activated protein kinase (MAPK). Furthermore, the recombinant protein blocked reactive oxygen species (ROS) production, abated mitochondrial dysfunction and significantly suppressed the assembly of the inflammasome, which led to the overproduction of proinflammatory cytokines IL-1β and IL-18. Mn-TAT PTD-Ngb increased the level of nuclear factor-erythroid 2 -related factor 2 (Nrf2), which protected against oxidative stress and improved pyroptosis. Mn-TAT PTD-Ngb might be a promising drug for curing neurological diseases.

Anti-Inflammatory Activity of Sanjie Zhentong Capsule Assessed By Network Pharmacology Analysis of Adenomyosis Treatment

Background

Sanjie Zhentong capsule (SZC) offers excellent effect in treating adenomyosis (AM), which is a common and difficult gynecological disease in the clinic. However, the systematic analysis of its mechanism has not been carried out yet and further studies are needed to reveal the role of SZC.

Methods

A systematic network pharmacology analysis was conducted by integrating construction of SZC compound database and AM target database, prediction of potential active compounds and targets by molecular docking combined with compound-target prediction graph (CTPG), protein-protein interaction (PPI) analysis, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Then, the anti-inflammation experiments in vitro were performed by investigating SZC and the representative compounds regulating nitric oxide (NO), interleukin-6 (IL-6), and interleukin-10 (IL-10).

Results

Our findings show that SZC mainly treated AM by stimulating 28 core targets through 30 key potential active compounds, and affecting 4 crucial pathways. The treatment was associated with inflammation reaction, hormone regulation, cell adhesion, proliferation, and angiogenesis. Additionally, SZC achieved the anti-inflammatory activity by the cooperation of the compounds through inhibiting NO and IL-6, both promoting and inhibiting IL-10.

Conclusion

This study investigated the anti-inflammatory activity of SZC based on a systematic analysis of SZC remedying AM, which was revealed to be one of the essential mechanisms. These findings will provide valuable guidance for further research of the SZC treatment of AM, and help improve the comprehension of SZC pharmacological basis as well as AM pathogenesis.

Increased Anti-Inflammatory Effects on LPS-Induced Microglia Cells by Spirulina maxima Extract from Ultrasonic Process

The Spirulina maxima exact from a non-thermal ultrasonic process (UE) contains 17.5 mg/g of total chlorophyll, compared to 6.24 mg/g of chlorophyll derived from the conventional 70% ethanol extraction at 80 °C for 12 h (EE). The UE also showed relatively low cytotoxicity against murine microglial cells (BV-2) and inhibited the production of the inflammatory mediators, NO and PGE2. The UE also effectively suppresses both mRNA expression and the production of pro-inflammatory cytokines, such as TNF-α, IL-6 and IL-1β, in a concentration-dependent manner. Notably, TNF-α gene and protein production were most strongly down-regulated, while IL-6 was the least affected by all ranges of treatment concentrations. This work first demonstrated a quantitative correlation between mRNA expression and the production of cytokines, showing that suppression of TNF-α gene expression was most significantly correlated with its secretion. These results clearly proved that the anti-inflammatory effects of Spirulina extract from a nonthermal ultrasonic process, which yielded high concentrations of intact forms of chlorophylls, were increased two-fold compared to those of conventional extracts processed at high temperature.

Synthesis, Biological Evaluation and Docking Studies of Chalcone and Flavone Analogs as Antioxidants and Acetylcholinesterase Inhibitors

Several oxidative processes are related to a wide range of human chronic and degenerative diseases, like Alzheimer’s disease, which also has been related to cholinergic processes. Therefore, search for new or improved antioxidant molecules with acetylcholinesterase activity is essential to offer alternative chemotherapeutic agents to support current drug therapies. A series of chalcone (2a–2k) and flavone (3a–3k) analogs were synthesized, characterized, and evaluated as acetylcholinesterase (AChE) inhibitors, and antioxidant agents using 1,1-diphenyl-2-picrylhydrazyl (DPPH•), 2-2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS•), and β-carotene/linoleic acid bleaching assay. Compounds more active were 3j and 2k in DPPH with EC50 of 1 × 10−8 and 5.4 × 10−3 μg/mL, respectively; 2g and 3i in ABTS (1.14 × 10−2 and 1.9 × 10−3 μg/mL); 2e, 2f, 3f, 2j, and 3j exceeded the α-tocopherol control in the β-carotene assay (98–99% of antioxidant activity). At acetylcholinesterase inhibition assay, flavones were more active than chalcones; the best results were compounds 2d and 3d (IC50 21.5 and 26.8 µg/mL, respectively), suggesting that the presence of the nitro group enhances the inhibitory activity. The docking of these two structures were made to understand their interactions with the AChE receptor. Although further in vivo testing must be performed, our results represent an important step towards the identification of improved antioxidants and acetylcholinesterase inhibitors.

New quinoline/chalcone hybrids as anti-cancer agents: Design, synthesis, and evaluations of cytotoxicity and PI3K inhibitory activity

A series of quinoline-chalcone hybrids was designed as potential anti-cancer agents, synthesized and evaluated. Different cytotoxic assays revealed that compounds experienced promising activity. Compounds 9i and 9j were the most potent against all the cell lines tested with IC₅₀ = 1.91-5.29 µM against A549 and K-562 cells. Mechanistically, 9i and 9j induced G₂/M cell cycle arrest and apoptosis in both A549 and K562 cells. Moreover, all PI3K isoforms were inhibited non selectively with IC₅₀s of 52-473 nM when tested against the two mentioned compounds with 9i being most potent against PI3K-γ (IC₅₀ = 52 nM). Docking of 9i and 9j showed a possible formation of H-bonding with essential valine residues in the active site of PI3K-γ isoform. Meanwhile, Western blotting analysis revealed that 9i and 9j inhibited the phosphorylation of PI3K, Akt, mTOR, as well as GSK-3β in both A549 and K562 cells, suggesting the correlation of blocking PI3K/Akt/mTOR pathway with the above antitumor activities. Together, our findings support the antitumor potential of quinoline-chalcone derivatives for NSCLC and CML by inhibiting the PI3K/Akt/mTOR pathway.

Ibrutinib suppresses LPS-induced neuroinflammatory responses in BV2 microglial cells and wild-type mice

Background

The FDA-approved small-molecule drug ibrutinib is an effective targeted therapy for patients with chronic lymphocytic leukemia (CLL). Ibrutinib inhibits Bruton’s tyrosine kinase (BTK), a kinase involved in B cell receptor signaling. However, the potential regulation of neuroinflammatory responses in the brain by ibrutinib has not been comprehensively examined.

Methods

BV2 microglial cells were treated with ibrutinib (1 μM) or vehicle (1% DMSO), followed by lipopolysaccharide (LPS; 1 μg/ml) or PBS. RT-PCR, immunocytochemistry, and subcellular fractionation were performed to examine the effects of ibrutinib on neuroinflammatory responses. In addition, wild-type mice were sequentially injected with ibrutinib (10 mg/kg, i.p.) or vehicle (10% DMSO, i.p.), followed by LPS (10 mg/kg, i.p.) or PBS, and microglial and astrocyte activations were assessed using immunohistochemistry.

Results

Ibrutinib significantly reduced LPS-induced increases in proinflammatory cytokine levels in BV2 microglial and primary microglial cells but not in primary astrocytes. Ibrutinib regulated TLR4 signaling to alter LPS-induced proinflammatory cytokine levels. In addition, ibrutinib significantly decreased LPS-induced increases in p-AKT and p-STAT3 levels, suggesting that ibrutinib attenuates LPS-induced neuroinflammatory responses by inhibiting AKT/STAT3 signaling pathways. Interestingly, ibrutinib also reduced LPS-induced BV2 microglial cell migration by inhibiting AKT signaling. Moreover, ibrutinib-injected wild-type mice exhibited significantly reduced microglial/astrocyte activation and COX-2 and IL-1β proinflammatory cytokine levels.

Conclusions

Our data provide insights on the mechanisms of a potential therapeutic strategy for neuroinflammation-related diseases.

Electronic supplementary material

The online version of this article (10.1186/s12974-018-1308-0) contains supplementary material, which is available to authorized users.

The synthetic chalcone derivative 2-hydroxy-3',5,5'-trimethoxychalcone induces unfolded protein response-mediated apoptosis in A549 lung cancer cells

The synthetic chalcone derivative 2-hydroxy-3',5,5'-trimenthoxyochalcone (named DK-139) exhibits anti-inflammatory and anti-tumor invasion properties. However, effects of DK-139 on tumor cell growth remain unknown. In the present study, we evaluated the inhibitory activity of DK-139 against human lung cancer cells. Treatment with DK-139 inhibited clonogenicity in various lung cancers and stimulated the caspase cascade, leading to the apoptosis of A549 lung cancer cells. To investigate the mode of action of DK-139-induced apoptosis, we analyzed the effect of DK-139 on the endoplasmic reticulum (ER) stress response. DK-139 increased expression of ER stress sensors, including p-PERK, GRP78/BiP, and IRE1α. IRE1α-regulated XBP-1 mRNA splicing and PERK-induced ATF4 expression was also upregulated following DK-139 treatment. In addition, expression levels of the pro-apoptotic transcription factor CHOP and its downstream target Bim, which is involved in mitochondria-mediated apoptosis, were increased by DK-139 treatment. These results suggest that DK-139 triggers caspase-mediated apoptosis via the ER stress-activated unfolded protein response (UPR) pathway. We propose that the synthetic chalcone derivative DK-139 may be used as a potential agent for the prevention and/or treatment of human lung cancer.

Clozapine reduces Toll-like receptor 4/NF-κB-mediated inflammatory responses through inhibition of calcium/calmodulin-dependent Akt activation in microglia

Clozapine is an atypical antipsychotic agent used in the treatment of schizophrenia and severe mood disorders. Accumulating evidence suggests that neuroinflammation is closely associated with the pathogenesis of various neurodegenerative diseases and psychiatric disorders. Clozapine exerts anti-inflammatory activity. However, the molecular mechanism underlying the anti-inflammatory activity of clozapine is poorly understood. In this study, we found that clozapine suppressed lipopolysaccharide (LPS)-induced phosphorylation of IκBα at Ser-32 and of p65/RelA at Ser-468, as well as nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)-dependent transcriptional activity in microglial cells. Clozapine downregulated LPS-induced Akt phosphorylation at Ser-473. Pharmacological Akt inhibitors ameliorated LPS-induced NF-κB activation. Removal of extracellular Ca²⁺ by EGTA or sequestration of intracellular Ca²⁺ by BAPTA-AM attenuated LPS-induced Akt phosphorylation. Treatment with calmodulin (CaM) antagonists and the CaM kinase inhibitor, KN-93, also prevented LPS-induced Akt and NF-κB activation, suggesting that Ca²⁺/CaM-dependent Akt activation is critical in LPS-induced NF-κB activation in microglia. These results suggest that clozapine exhibits anti-inflammatory activity through the inhibition of Ca²⁺/CaM/Akt-mediated NF-κB activation.

Tamarix hohenackeri Bunge exerts anti-inflammatory effects on lipopolysaccharide-activated microglia in vitro

BACKGROUND

Tamarix species are well known as the main host plants of Herba Cistanches, a valuable Traditional Chinese Medicine. They are also traditional medicinal plants themselves and are used to treat spleen problems, leucoderma and ocular conditions.

PURPOSE

The aim of the present study was to investigate the anti-inflammatory effect of Tamarix hohenackeri Bunge.

METHODS

In the present study, BV-2 microglial cells were used and stimulated with lipopolysaccharide (LPS). Cell viability was tested using the MTT assay. The release of nitric oxide (NO) was determined using the Griess assay. The mRNA level of inducible nitric oxide synthase (iNOS), tumor necrosis factor α (TNF-α), interleukin (IL)-1β and IL-6 were investigated by quantitative real-time PCR (qRT-PCR). The protein levels of phosphorylated of IκBα, ERK and MEK, as well as the cytoplasmic and nuclear NF-κB p65 were tested by Western blot analysis. The translocation of the NF-κB p65 subunit from the cytosol to the nucleus was investigated by immunofluorescence staining.

RESULTS

Ethyl acetate (EtOAc) extract of Tamarix hohenackeri Bunge significantly inhibited the release of NO. Phytochemical research was performed to produce 13 main constituents. Among them, compounds 6, 7, 10 and 13 were identified to be the effective components with anti-inflammatory activity. These compounds significantly inhibited the production of NO by LPS-activated BV-2 microglial cells. qRT-PCR showed that compounds 6 and 7 significantly suppressed the LPS-induced transcription of genes encoding pro-inflammatory mediators, including iNOS, TNF-α, IL-1β and IL-6. Western blot analysis showed that compound 7 inhibited the LPS-induced phosphorylation of IκBα and antagonized the LPS-induced reduction of cytoplasmic NF-κB p65 and the increase of nuclear NF-κB p65. Immunofluorescence staining showed that nuclear translocation of NF-κB p65 was suppressed by compound 7. Western blot analysis showed that compound 7 inhibited the LPS-induced phosphorylation of ERK and MEK.

CONCLUSION

The present study revealed, for the first time, the effective anti-inflammatory agents from T. Hohenackeri. Compound 7 exerted potent anti-inflammatory effects and its underlying mechanism may be associated with its capacity to inhibit NF-κB signaling pathway and the MEK/ERK activation in activated microglia. The compound may be potential candidate therapeutic agent for neurodegenerative diseases.

A novel chalcone derivative S17 induces apoptosis through ROS dependent DR5 up-regulation in gastric cancer cells

A new series of etherification chalcone derivatives were designed and synthesized through Willimison etherification and Claisen-Schmidt condensation. Among them, compound 2-c which was given chemical name of S17, has been successfully screened out as the most potent one on gastric cancer cell line(MGC803) through the investigation for their effects against the growth of five cancer cell lines (EC109, HepG2, MCF7, MGC803, SKNSH). S17 exhibited strong anti-proliferative activity on other two gastric cancer cells (HGC27 and SGC7901), but less cytotoxicity to non-malignant gastric epithelial cells GES1. S17 potently killed gastric cancer cells with causing modulation of Bcl-2 family proteins and activation of caspase 9/3 cascade. S17 also up-regulated DR5 expression and DR5 knockdown partially reversed S17-induced apoptosis, caspase activation and MMP decrease. S17 robustly induced generation of ROS with Keap/Nrf2 pathway activated and the application of ROS scavenger N-acetyl cysteine (NAC) completely blocked these effects by S17 in MGC803 cells. Intraperitoneal administration of S17 significantly inhibited the growth of MGC803 cells in vivo in a xenograft mouse model without observed toxicity. These results indicated that S17 is a leadbrominated chalcone derivate and deserves further investigation for prevention and treatment of gastric cancer.

Chalcone: A Privileged Structure in Medicinal Chemistry

Privileged structures have been widely used as an effective template in medicinal chemistry for drug discovery. Chalcone is a common simple scaffold found in many naturally occurring compounds. Many chalcone derivatives have also been prepared due to their convenient synthesis. These natural products and synthetic compounds have shown numerous interesting biological activities with clinical potentials against various diseases. This review aims to highlight the recent evidence of chalcone as a privileged scaffold in medicinal chemistry. Multiple aspects of chalcone will be summarized herein, including the isolation of novel chalcone derivatives, the development of new synthetic methodologies, the evaluation of their biological properties, and the exploration of the mechanisms of action as well as target identification. This review is expected to be a comprehensive, authoritative, and critical review of the chalcone template to the chemistry community.

Okanin, effective constituent of the flower tea Coreopsis tinctoria, attenuates LPS-induced microglial activation through inhibition of the TLR4/NF-κB signaling pathways

The EtOAc extract of Coreopsis tinctoria Nutt. significantly inhibited LPS-induced nitric oxide (NO) production, as judged by the Griess reaction, and attenuated the LPS-induced elevation in iNOS, COX-2, IL-1β, IL-6 and TNF-α mRNA levels, as determined by quantitative real-time PCR, when incubated with BV-2 microglial cells. Immunohistochemical results showed that the EtOAc extract significantly decreased the number of Iba-1-positive cells in the hippocampal region of LPS-treated mouse brains. The major effective constituent of the EtOAc extract, okanin, was further investigated. Okanin significantly suppressed LPS-induced iNOS expression and also inhibited IL-6 and TNF-α production and mRNA expression in LPS-stimulated BV-2 cells. Western blot analysis indicated that okanin suppressed LPS-induced activation of the NF-κB signaling pathway by inhibiting the phosphorylation of IκBα and decreasing the level of nuclear NF-κB p65 after LPS treatment. Immunofluorescence staining results showed that okanin inhibited the translocation of the NF-κB p65 subunit from the cytosol to the nucleus. Moreover, okanin significantly inhibited LPS-induced TLR4 expression in BV-2 cells. In summary, okanin attenuates LPS-induced activation of microglia. This effect may be associated with its capacity to inhibit the TLR4/NF-κB signaling pathways. These results suggest that okanin may have potential as a nutritional preventive strategy for neurodegenerative disorders.

TLR4-mediated IRAK1 activation induces TNF-α expression via JNK-dependent NF-κB activation in human bronchial epithelial cells

The purpose of this study was to identify the mechanism of lipopolysaccharide (LPS)-induced expression of tumor necrosis factor (TNF)-α in BEAS-2B. Toll-like receptor (TLR)4-specific siRNA was found to completely abolish the LPS-induced expression of MyD88 and TNF-α. There was enhanced binding of MyD88 with IRAK1 following LPS treatment, and MyD88- or IRAK1-specific siRNAs decreased the expression of TNF-α. In addition, IRAK1 siRNA downregulated the phosphorylation of PKCα, demonstrating that PKCα is a downstream effector of IRAK1. Inhibition of PKCα completely blocked the activation of AKT, whereas inhibition of AKT with a PI3K inhibitor prevented the LPS-induced expression of TNF-α. We found that AKT activated JNK, which then stimulated phosphorylation of Iκ-Bα, resulting in NF-κB activation. As expected, inhibition of NF-κB completely inhibited the expression of TNF-α. Taken together, our results suggest that LPS induces TNF-α expression by activating NF-κB via the PKCα/PI3K/AKT/JNK pathway, which is in turn dependent on MyD88/IRAK1.

Inhibitory Effect of 3-(4-Hydroxyphenyl)-1-(thiophen-2-yl) prop-2-en-1-one, a Chalcone Derivative on MCP-1 Expression in Macrophages via Inhibition of ROS and Akt Signaling

Chalcones (1,3-diaryl-2-propen-1-ones), a subfamily of flavonoid, are widely known to possess potent anti-inflammatory and anti-oxidant properties. In this study, we investigated the effect of 3-(4-Hydroxyphenyl)-1-(thio3-(4-Hydroxyphenyl phen-2-yl)prop-2-en-1-one (TI-I-175), a synthetic chalcone derivative, on endotoxin-induced expression of monocyte chemoattractant protein-1 (MCP-1), one of the key chemokines that regulates migration and infiltration of immune cells, and its potential mechanisms. TII-175 potently inhibited MCP-1 mRNA expression stimulated by lipopolysaccharide (LPS) in RAW 264.7 macrophages without significant effect on cell viability. Treatment of cells with TI-I-175 markedly prevented LPS-induced transcriptional activation of activator protein-1 (AP-1) as measured by luciferase reporter assay, while nuclear factor-κB (NF-κB) activity was not inhibited by TI-I-175, implying that TI-I-175 suppressed MCP-1 expression probably via regulation of AP-1. In addition, TI-I-175 treatment significantly inhibited LPS-induced Akt phosphorylation and led to a significant decrease in reactive oxygen species (ROS) production by LPS, which act as up-stream signaling events required for AP-1 activation in RAW 264.7 macrophages. Taken together, these results indicate that TI-I-175 suppresses MCP-1 gene expression in LPS-stimulated RAW 264.7 macrophages via suppression of ROS production and Akt activation.

2-Hydroxy-3,4-naphthochalcone (2H-NC) inhibits TNFα-induced tumor invasion through the downregulation of NF-κB-mediated MMP-9 gene expression

The control of tumor metastasis is important for the successful prevention and treatment of cancer. Emerging evidence indicates that various natural and synthetic chalcones exhibit antimetastatic activity through the inhibition of nuclear factor-κB (NF-κB), although the precise mechanism by which this occurs is currently unclear. In this study, 2-hydroxy-3,4-naphthochalcone (2H-NC) was found to reduce tumor necrosis factor alpha (TNFα)-induced MMP-9 mRNA expression and gelatinolytic enzyme activity. These actions were associated with inhibition of RelA/p65 NF-κB activity. In addition, 2H-NC inhibited TNFα-induced invasion of MDA-MB-231 breast cancer cells, as assessed using a three-dimensional spheroid invasion assay. Taken together, these data demonstrate that 2H-NC prevents TNFα-induced tumor cell invasion through downregulation of NF-κB-mediated MMP-9 gene expression, and thereby identify naphthochalcones as a potentially effective class of molecules to use as a platform for the development of antimetastatic agents.

Natural potential therapeutic agents of neurodegenerative diseases from the traditional herbal medicine Chinese dragon's blood

ETHNOPHARMACOLOGICAL RELEVANCE

Dragon's blood has been used as a famous traditional medicine since ancient times by many cultures. It is a deep red resin, obtained from more than 20 different species of four distinct genera. Red resin of Dracaena cochinchinensis S.C. Chen, known as Chinese dragon's blood or Yunnan dragon's blood, has been shown to promote blood circulation, alleviate inflammation, and to treat stomach ulcers, diarrhea, diabetes, and bleeding. This study investigated an effective approach to identify natural therapeutic agents for neurodegeneration from herbal medicine. The dichloride extract and isolated effective constituents of Chinese dragon's blood showed quinone oxidoreductase 1 (NQO1) inducing activity and anti-inflammatory effect significantly, which are therapy targets of various neurodegenerative diseases.

MATERIALS AND METHODS

Multiple chromatography and spectra analysis were utilized to afford effective constituents. Then Hepa 1c1c7 and BV-2 cells were employed to assay their NQO1 inducing and anti-inflammatory activities, respectively.

RESULTS

Bioactivities guided isolation afforded 21 effective constituents, including two new polymers cochinchinenene E (1), cochinchinenene F (2) and a new steroid dracaenol C (16). The main constituent 3 (weight percent 0.2%), 5 (weight percent 0.017%), 4 (weight percent 0.009%), 9 (weight percent 0.094%), 10 (weight percent 0.017%) and 8 (weight percent 0.006%) are responsible for the anti-inflammatory activities of Chinese dragon's blood. While, new compounds 1, 2 and known compounds 5, 11 showed good NQO1 inducing activities. The brief feature of the activities and structures was discussed accordingly.

CONCLUSION

Overviewing the bioactivities and phytochemical study result, 4'-hydroxy-2,4-dimethoxydihydrochalcone (3) and pterostilbene (5) as effective constituents of Chinese dragon's blood, were found to be potential candidate therapeutic agents for neurodegenerative diseases.

Ethanol extract of Poria cocos reduces the production of inflammatory mediators by suppressing the NF-kappaB signaling pathway in lipopolysaccharide-stimulated RAW 264.7 macrophages

Background

Poria cocos Wolf, a medicinal fungus, is widely used in traditional medicines in East Asian countries owing to its various therapeutic potentials. Although several studies have demonstrated the anti-inflammatory activity of this fungus, its underlying mechanisms have not yet been clearly defined.

Methods

In the present study, we have demonstrated the anti-inflammatory effects of ethanol extract of P. cocos (EEPC) in lipopolysaccaride (LPS)-stimulated RAW 264.7 macrophages. As inflammatory parameters, the productions of nitric oxide (NO), prostaglandin E2 (PGE2), interleukin (IL)-1β and tumor necrosis factor (TNF)-α were evaluated. We also examined the EEPC’s effect on the nuclear factor-kappaB (NF-κB) signaling pathway.

Results

Our results indicated that EEPC exhibits a potent inhibitory effect on NO production and inhibits PGE2 release in LPS-induced macrophages without affecting cell viability. EEPC also significantly attenuated LPS-induced secretion of inflammatory cytokines IL-1β and TNF-α. Additionally, LPS-induced expression of inducible NO synthase (iNOS), cyclooxygenase (COX)-2, IL-1β, and TNF-α was decreased by pre-treatment with EEPC at the transcriptional level. Moreover, EEPC clearly inhibited LPS-induced nuclear translocation of NF-κB p65 subunits, which correlated with EEPC’s inhibitory effects on inhibitor kappaB (IκB) degradation. Moreover, EEPC clearly suppressed the LPS-induced DNA-binding activity of NF-κB, as well as the nuclear translocation of the NF-κB p65, which correlated with EEPC’s inhibitory effects on inhibitor kappaB (IκB) degradation.

Conclusions

Taken together, our data indicates that EEPC targets the inflammatory response of macrophages via inhibition of iNOS, COX-2, IL-1β, and TNF-α through inactivation of the NF-κB signaling pathway, supporting the pharmacological basis of P. cocos as a traditional herbal medicine for treatment of inflammation and its associated disorders.

4-methoxychalcone enhances cisplatin-induced oxidative stress and cytotoxicity by inhibiting the Nrf2/ARE-mediated defense mechanism in A549 lung cancer cells

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a key transcriptional regulator for the protection of cells against oxidative and xenobiotic stresses. Recent studies have demonstrated that high constitutive expression of Nrf2 is observed in many types of cancer cells showing resistance to anti-cancer drugs, suggesting that the suppression of overexpressed Nrf2 could be an attractive therapeutic strategy to overcome cancer drug resistance. In the present study, we aimed to find small molecule compounds that enhance the sensitivity of tumor cells to cisplatin induced cytotoxicity by suppressing Nrf2-mediated defense mechanism. A549 lung cancer cells were shown to be more resistant to the anti-cancer drug cisplatin than HEK293 cells, with higher Nrf2 signaling activity; constitutively high amounts of Nrf2-downstream target proteins were observed in A549 cells. Among the three chalcone derivatives 4-methoxy-chalcone (4-MC), hesperidin methylchalcone, and neohesperidin dihydrochalcone, 4-MC was found to suppress transcriptional activity of Nrf2 in A549 cells but to activate it in HEK293 cells. 4-MC was also shown to down-regulate expression of Nrf2 and the downstream phase II detoxifying enzyme NQO1 in A549 cells. The PI3K/Akt pathway was found to be involved in the 4-MC-induced inhibition of Nrf2/ARE activity in A549 cells. This inhibition of Nrf2 signaling results in the accelerated generation of reactive oxygen species and exacerbation of cytotoxicity in cisplatin-treated A549 cells. Taken together, these results suggest that the small molecule compound 4-MC could be used to enhance the sensitivity of tumor cells to the therapeutic effect of cisplatin through the regulation of Nrf2/ARE signaling.

Ethanol extract of Cnidium officinale exhibits anti-inflammatory effects in BV2 microglial cells by suppressing NF-κB nuclear translocation and the activation of the PI3K/Akt signaling pathway

Chronic microglial activation endangers neuronal survival through the release of various toxic pro-inflammatory molecules; thus, negative regulators of microglial activation have been identified as potential therapeutic candidates for several neurological diseases. In this study, we investigated the inhibitory effects of an ethanol extract of Cnidium officinale rhizomes (EECO), which has been used as a herbal drug in Oriental medicine, on the production of lipopolysaccharide (LPS)-induced pro-inflammatory mediators, such as nitric oxide (NO) and prostaglandin E₂ (PGE₂), as well as that of pro-inflammatory cytokines in BV2 microglia cells. EECO significantly inhibited the excess production of NO and PGE₂ in LPS-stimulated BV2 microglia cells. It also attenuated the expression of inducible NO synthase, cyclooxygenase-2, as well as that of pro-inflammatory cytokines, such as interleukin-1β and tumor necrosis factor-α. Moreover, EECO exhibited anti-inflammatory properties by suppressing nuclear factor-κB (NF-κB) translocation and the activation of the phosphoinositide 3-kinase/Akt pathway in LPS-stimulated BV2 cells. These results indicate that EECO exerts anti-inflammatory effects in LPS-stimulated BV2 microglial cells by inhibiting pro-inflammatory mediators and cytokine production by blocking the NF-κB pathway. These findings suggest that EECO has substantial therapeutic potential for the treatment of neurodegenerative diseases accompanied by microglial activation.

Anti-inflammatory effects of saponins derived from the roots of Platycodon grandiflorus in lipopolysaccharide‑stimulated BV2 microglial cells

Radix platycodi is the root of Platycodon grandiflorus A. DC, which has been widely used as a food material and for the treatment of a number of chronic inflammatory diseases in traditional oriental medicine. In this study, the anti‑inflammatory effects of the saponins isolated from radix platycodi (PGS) on the production of inflammatory mediators and cytokines in lipopolysaccharide (LPS)-stimulated BV2 murine microglial cells were examined. We also investigated the effects of PGS on LPS‑induced nuclear factor‑κB (NF-κB) activation and phosphoinositide 3-kinase (PI3K)/AKT and mitogen-activated protein kinase (MAPK) signaling pathways. Following stimulation with LPS, elevated nitric oxide (NO), prostaglandin E2 (PGE2) and pro-inflammatory cytokine production was detected in the BV2 microglial cells. However, PGS significantly inhibited the excessive production of NO, PGE2 and pro‑inflammatory cytokines, including interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in a concentration-dependent manner without causing any cytotoxic effects. In addition, PGS suppressed NF-κB translocation and inhibited the LPS-induced phosphorylation of AKT and MAPKs. Our results indicate that the inhibitory effect of PGS on LPS-stimulated inflammatory response in BV2 microglial cells is associated with the suppression of NF-κB activation and the PI3K/AKT and MAPK signaling pathways. Therefore, these findings suggest that PGS may be useful in the treatment of neurodegenerative diseases by inhibiting inflammatory responses in activated microglial cells.

Ganoderma lucidum ethanol extract inhibits the inflammatory response by suppressing the NF-κB and toll-like receptor pathways in lipopolysaccharide-stimulated BV2 microglial cells

Ganoderma lucidum is a traditional Oriental medicine that has been widely used as a tonic to promote longevity and health in Korea and other Asian countries. Although a great deal of work has been carried out on the therapeutic potential of this mushroom, the pharmacological mechanisms of its anti-inflammatory actions remain unclear. In this study, we evaluated the inhibitory effects of G. lucidum ethanol extract (EGL) on the production of inflammatory mediators and cytokines in lipopolysaccharide (LPS)-stimulated murine BV2 microglia. We also investigated the effects of EGL on the LPS-induced activation of nuclear factor kappaB (NF-κB) and upregulation of toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 (MyD88). Elevated levels of nitric oxide (NO), prostaglandin E(2) (PGE(2)) and pro-inflammatory cytokine production were detected in BV2 microglia following LPS stimulation. We identifed that EGL significantly inhibits the excessive production of NO, PGE(2) and pro-inflammatory cytokines, including interleukin (IL)-1β and tumor necrosis factor-α in a concentration-dependent manner without causing cytotoxicity. In addition, EGL suppressed NF-κB translocation and transcriptional activity by blocking IκB degradation and inhibiting TLR4 and MyD88 expression in LPS-stimulated BV2 cells. Our results indicate that the inhibitory effects of EGL on LPS-stimulated inflammatory responses in BV2 microglia are associated with the suppression of the NF-κB and TLR signaling pathways. Therefore, EGL may be useful in the treatment of neurodegenerative diseases by inhibiting inflammatory mediator responses in activated microglia.