LPS-stimulated BV2 Microglial Cells Research Articles

The Anti-Inflammatory Activities of Benzylideneacetophenone Derivatives in LPS Stimulated BV2 Microglia Cells and Mice.

A previously reported study highlighted the neuroprotective potential of the novel benzylideneacetophenone derivative, JC3, in mice. In pursuit of compounds with even more robust neuroprotective and anti-inflammatory properties compared to JC3, we synthesized substituted 1,3-diphenyl-2-propen-1-ones based on chalcones. Molecular modeling studies aimed at discerning the chemical structural features conducive to heightened biological activity revealed that JCII-8,10,11 exhibited the widest HOMOLUMO gap within this category, indicating facile electron and radical transfer between HOMO and LUMO in model assessments. From the pool of synthesized compounds, JCII-8,10,11 were selected for the present investigation. The biological assays involving JCII-8,10,11 demonstrated their concentration-dependent suppression of iNOS and COX-2 protein levels, alongside various cytokine mRNA expressions in LPS-induced murine microglial BV2 cells. Furthermore, western blot analyses were conducted to investigate the MAPK pathways and NF-κB/p65 nuclear translocation. These evaluations conclusively confirmed the inflammatory inhibition effects in both in vitro and in vivo inflammation models. These findings establish JCII-8,10,11 as potent anti-inflammatory agents, hindering inflammatory mediators and impeding NF-κB/p65 nuclear translocation via JNK and ERK MAPK phosphorylation in BV2 cells. The study positions them as potential therapeutics for inflammation-related conditions. Additionally, JCII-11 exhibited greater activity compared to other tested JCII compounds.

The Neolignan Honokiol and Its Synthetic Derivative Honokiol Hexafluoro Reduce Neuroinflammation and Cellular Senescence in Microglia Cells.

Microglia-mediated neuroinflammation has been linked to neurodegenerative disorders. Inflammation and aging contribute to microglial senescence. Microglial senescence promotes the development of neurodegenerative disorders, including Alzheimer's disease (AD). In this study, we investigated the anti-neuroinflammatory and anti-senescence activity of Honokiol (HNK), a polyphenolic neolignane from Magnolia officinalis Rehder & E.H Wilson, in comparison with its synthetic analogue Honokiol Hexafluoro (CH). HNK reduced the pro-inflammatory cell morphology of LPS-stimulated BV2 microglia cells and increased the expression of the anti-inflammatory cytokine IL-10 with an efficacy comparable to CH. HNK and CH were also able to attenuate the alterations in cell morphology associated with cellular senescence in BV2 cells intermittently stimulated with LPS and significantly reduce the activity and expression of the senescence marker ß-galactosidase and the expression of p21 and pERK1/2. The treatments reduced the expression of senescence-associated secretory phenotype (SASP) factors IL-1ß and NF-kB, decreased ROS production, and abolished H2AX over phosphorylation (γ-H2AX) and acetylated H3 overexpression. Senescent microglia cells showed an increased expression of the Notch ligand Jagged1 that was reduced by HNK and CH with a comparable efficacy to the Notch inhibitor DAPT. Overall, our data illustrate a protective activity of HNK and CH on neuroinflammation and cellular senescence in microglia cells involving a Notch-signaling-mediated mechanism and suggesting a potential therapeutic contribution in aging-related neurodegenerative diseases.

Taxus chinensis (Pilg.) Rehder fruit attenuates aging behaviors and neuroinflammation by inhibiting microglia activation via TLR4/NF-κB/NLRP3 pathway

Ethnopharmacological relevanceAs one of the important by-products of Taxus chinensis (Pilg.) Rehder, its fruit (TCF) has a sweet taste, which is commonly used in folklore to make health care wine reputed for enhancing immune function and promoting anti-aging effects, especially popular in the longevity villages of China for a long history. Evidences had showed that Taxus chinensis fruit contained polysaccharides, flavonoids, amino acids and terpenoids, which all were free of toxic compounds , but its medicinal value has not been fully recognized. Our previous studies have found that TCF extract may reverse many biological events, including oxidative stress, inflammatory response, neuronal apoptosis, etc. by in silico methods, suggesting potential avenues for future pharmaceutical exploration in aging and age-related diseases. Aim of the studyYet, the anti-aging properties of TCF have not been specifically studied, this study aims to fill this gap by investigating the effects of TCF extract (TCFE) in an aging mouse model, particularly focusing on its role in inhibiting microglial activation and elucidating its underlying anti-aging mechanisms. Materials and methodsAn aging mouse model was induced using D-galactose, with interventions involving high, medium, and low doses of TCFE compared to a positive control (2mg/kg rapamycin combined with 100mg/kg metformin). The methodology involved evaluating behavioral changes, serum oxidative and antioxidative markers, hypothalamic β-galactosidase activity, expression of the aging-related protein P63, serum inflammatory factors, and the TLR4/NF-κB/NLRP3 inflammatory pathway in hypothalamic tissues. Additionally, to strengthen our in vivo findings, we conducted in vitro experiments on LPS-stimulated BV2 microglial cells. Finally, UPLC-MS/MS for precise component analysis using compound standards, coupled with molecular docking analyses, were employed to discern and elucidate the anti-inflammatory mechanisms of TCF. ResultsIn vivo results revealed TCFE significantly ameliorated behavioral deficits, reduced oxidative stress markers (MDA) and pro-inflammatory cytokines (IL1-β, IL-6, IFNg, TNFα, IL-17), and increased in antioxidants (SOD, T-AOC) and anti-inflammatory factors (IL-10). TCFE also reduced hypothalamic senescence, improved cellular integrity, lowered p63, and inhibited microglia activation and inflammatory pathways (TLR4, NFKB, NLRP3). The overall effect of TCFE was better than that of the positive drug group (rapamycin combined with metformin). In vitro results further revealed that TCFE markedly decreased IL1-β, NFKB, and TLR4 levels in BV2 microglial cells, showing comparable efficacy to a TLR4 classic positive inhibitor C34, supporting its anti-inflammatory role. Through UPLC-MS/MS analysis coupled with compound standards, we identified ten bioactive compounds, including gallocatechin, epigallocatechin, catechin, procyanidin B2, kaempferol, quercetin, rutin, naringin, apigenin, ginkgetin. All these compounds showed strong binding affinity to TLR4, notably procyanidin B2 and rutin, potentially through hydrogen bonds, aromatic cation-π interactions, and hydrophobic interactions, suggesting a molecular basis for their anti-inflammatory action. ConclusionTCFE showed strong anti-aging effects by inhibiting microglia activation and lessening oxidative stress and modulating inflammatory pathways. This research supports TCF's use in anti-aging and sets a base for future drug development in the realms of neuroinflammation and aging.

Anti-neuroinflammatory potential of hydroxybenzoic ester derivatives: In silico insight and in vitro validation

This study explores the anti-neuroinflammatory and antioxidant potential of 42 hydroxybenzoic acid esters and three parent acids. Molecular docking simulations targeted key proteins involved in the lipopolysaccharide (LPS) signaling pathway to identify lead compounds for synthesis and in vitro evaluation. Among the screened esters, the most promising candidates demonstrated antioxidant activity comparable to vitamin C in ABTS and DPPH assays. Additionally, these esters significantly reduced the production of reactive oxygen species (ROS) and nitric oxide (NO) in H2O2- and LPS-stimulated BV2 microglial cells, indicating their ability to attenuate neuroinflammation. Further testing in SH-SY5Y neuronal cells exposed to microglia-derived supernatants confirmed the neuroprotective effects of these esters, reducing microglia-mediated neurotoxicity. These results suggest that hydroxybenzoic acid ester derivatives are promising candidates for mitigating microglia-driven neuroinflammation and protecting neurons, offering potential therapeutic applications for neurodegenerative diseases.

Axially chiral dihydrophenanthrene dimers from Pholidota yunnanensis with anti-neuroinflammatory activities

Axially chiral compounds are well known in medicinal chemistry of natural products, but their absolute configurations and bioactivities are rarely reported and studied. In this study, eleven undescribed axially chiral dihydrophenanthrene dimers, as well as twenty-five known dihydrophenanthrenes, were isolated from the entire plant of Pholidota yunnanensis. Their structures were elucidated by comprehensive spectroscopic analysis. A method for determining the absolute configurations of enantiomers was developed based on the rotational barriers and calculated ECD spectra. Additionally, the activities of all isolated compounds were assessed in LPS-induced BV-2 microglial cells. Most dihydrophenanthrenes exhibited significant NO inhibitory activities, and compound 7 showed the most potent inhibitory effect with an IC50 value of 1.5 μM, compared to the positive control minocycline. The immunofluorescence and western blot results revealed that compound 7 suppressed the expression of Iba-1, iNOS and COX-2 in LPS-stimulated BV-2 microglial cells.

Neuroinflammation and acetylcholinesterase inhibition potentials of acyclic monoterpenoids isolated from Cymbopogon distans (Nees ex Steud.) Will. Watson

Cymbopogon distans (Nees ex Steud.) Will. Watson (Poaceae) is a promising aromatic plant distributed in the Himalayas. In this study, five acyclic monoterpenoids, namely geranyl acetate (RS1), neral (RS2), geranial (RS3), citral (RS4) and geraniol (RS5) were isolated from the essential oil of C. distans. The isolated compounds were tested for in-vitro neuroinflammation inhibitory potential in LPS-stimulated BV2 microglial cells. RS1-RS4 exhibited significant neuroinflammation inhibition without any cytotoxic effect at the dose of 10 μM. RS4, the most active anti-neuroinflammatory compound (TNF-α 31.48 ± 1.00%; IL-6 24.02 ± 0.63%; IL-1β 42.15 ± 1.76%) was also able to inhibit acetylcholinesterase (AChE) in a dose-dependent manner. The results showed that RS4 (an isomeric mixture of neral and geranial) has the potential to inhibit neuroinflammation and AChE, which are the biomarkers of neurodegenerative disorders.

The TLR4/NF-κB/NLRP3 and Nrf2/HO-1 pathways mediate the neuroprotective effects of alkaloids extracted from Uncaria rhynchophylla in Parkinson's disease

Ethnopharmacological relevanceParkinson's disease (PD) is the second most common neurodegenerative disorder with limited therapeutic options available. Neuroinflammation plays an important role in the occurrence and development of PD. Alkaloids extracted from Uncaria rhynchophylla (URA), have emerged as a potential neuroprotective agent because of its anti-inflammatory and anti-oxidant properties. Nevertheless, the underlying mechanism by which URA exerts neuroprotective effects in PD remains obscure. Aim of the studyThe main aim of this study was to investigate the neuroprotective effects and underlying mechanism of URA in the treatment of PD through in vivo and in vitro models, focusing on the neuroinflammation and oxidative stress pathways. Materials and methodsThe protective effects of URA against PD were evaluated by neurobehavioral tests, immunohistochemistry, serum biochemical assays, and real-time quantitative polymerase chain reaction in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mice. The role of the TLR4/NF-κB/NLRP3 pathway and the Nrf2/HO-1 pathway in URA-mediated effects was examined in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells and a microglia-neuron coculture system. ResultsURA significantly alleviated motor deficits and dopaminergic neurotoxicity, and reversed the abnormal secretion of inflammatory and oxidative stress factors in the serum of MPTP-induced mice. URA suppressed the gene expression of Toll-like receptor 4 (TLR4), NOD-like receptor protein 3, and cyclooxygenase 2 (COX2) in the striatum of PD mice. Further studies indicated that URA inhibited activation of the TLR4/NF-κB/NLRP3 pathway and enhanced activation of the Nrf2/HO-1 pathway, reduced reactive oxygen species (ROS) production, and reversed the secretion of inflammatory mediators in LPS-stimulated BV-2 microglial cells, thereby alleviating neuroinflammatory damage to SH-SY5Y neuronal cells. ConclusionURA exerted neuroprotective effects against PD mainly by the inhibition of the TLR4/NF-κB/NLRP3 pathway and activation of the Nrf2/HO-1 antioxidant pathway, highlighting URA as a promising candidate for PD treatment.

Ent-eudesmane sesquiterpenoids with anti-neuroinflammatory activity from the marine-derived fungus Eutypella sp. F0219

In this study, twenty-three ent-eudesmane sesquiterpenoids (1–23) including fifteen previously undescribed ones, named eutypelides A–O (1–15) were isolated from the marine-derived fungus Eutypella sp. F0219. Their planar structures and relative configurations were established by HR-ESIMS and extensive 1D and 2D NMR investigations. The absolute configurations of the previously undescribed compounds were determined by single-crystal X-ray diffraction analyses, modified Mosher's method, and ECD calculations. Structurally, eutypelide A (1) is a rare 1,10-seco-ent-eudesmane, whereas 2–15 are typically ent-eudesmanes with 6/6/-fused bicyclic carbon nucleus. The anti-neuroinflammatory activity of all isolated compounds (1−23) was accessed based on their ability to NO production in LPS-stimulated BV2 microglia cells. Compound 16 emerged as the most potent inhibitor. Further mechanistic investigation revealed that compound 16 modulated the inflammatory response by decreasing the protein levels of iNOS and increasing ARG 1 levels, thereby altering the iNOS/ARG 1 ratio and inhibiting macrophage polarization. qRT-PCR analysis showed that compound 16 reversed the LPS-induced upregulation of pro-inflammatory cytokines, including iNOS, TNF-α, IL-6, and IL-1β, at both the transcriptional and translational levels. These effects were linked to the inhibition of the NF-κB pathway, a key regulator of inflammation. Our findings suggest that compound 16 may be a potential structure basis for developing neuroinflammation-related disease therapeutic agents.

Abietane-Type Diterpenoids from the Arils of Torreya grandis.

A chemical investigation of the arils of Torreya grandis led to the isolation of seven abietane-type diterpenoids (compounds 1-7) including three previously undescribed compounds, one unreported natural product, and three known analogs. The structures of these compounds were determined by means of spectroscopy, single-crystal X-ray diffraction, and ECD spectra. An antibacterial activity assay showed that compounds 5 and 6 had significant inhibitory effects on methicillin-resistant Staphylococcus aureus, with MIC values of 100 μM. Moreover, compounds 1, 3, 4, and 7 exhibited anti-neuroinflammatory activity in LPS-stimulated BV-2 microglia cells, with the IC50 values ranging from 38.4 to 67.9 μM.

Discovery of potential components characteristic by conjugated enone from the branches and leaves of Croton lauioides with anti-neuroinflammatory activity via regulating the NF-κB pathway

In this study, the chemical composition and pharmacological activity of Croton lauioides were investigated for the first time. The bioactive and HPLC-UV guided isolation led to the discovery of twenty-three conjugated enone-type components (1–23), including nine previously unknown sesquiterpenoid derivatives (1–4, 9–10, 12–14). Notably, compounds 1 and 12 are epoxides containing an endoperoxide bridge (1) or a unique dioxaspiro core (12), respectively. Compounds 2–7 are non-benzenoid aromatics featuring a tropone function, while 9–11 possess a rare rearranged scaffold with tropone shift into benzene. Extensive characterization was performed using NMR spectra, HRESIMS data, and electronic circular dichroism (ECD) calculations. Furthermore, we evaluated the bioactivities of all isolated compounds against neuroinflammation in LPS-stimulated BV-2 microglial cells. Remarkably, most sesquiterpenoid derivatives exhibited significant NO inhibit activities, and compound 5 showed the most potent effect with an IC50 value of 0.14 ± 0.04 μM. Structure-activity relationship (SAR) analysis revealed that sesquiterpenoids modified with endocyclic enone conjugation may serve as a key pharmacophore for NO inhibition, particularly involving aromatic tropone moiety. The qPCR and Western blot results demonstrated that 5 exerted an inhibitory effect on the mRNA levels of iNOS, TNF-α and COX-2 in a time-dependent manner, as well as suppressed the protein expression of iNOS, TNF-α, COX-2. In mechanism, 5 could prevented activation of NF-κB pathway by suppressing phosphorylation of p65 and IκB-α. These findings revealed C. lauioides might be a promising resource for drug candidate development targeting neuroinflammation.

Aerobic exercise attenuates LPS-induced cognitive dysfunction by reducing oxidative stress, glial activation, and neuroinflammation

Physical activity has been considered an important non-medication intervention in preserving mnemonic processes during aging. However, how aerobic exercise promotes such benefits for human health remains unclear. In this study, we aimed to explore the neuroprotective and anti-inflammatory effects of aerobic exercise against lipopolysaccharide (LPS)-induced amnesic C57BL/6J mice and BV-2 microglial cell models. In the in vivo experiment, the aerobic exercise training groups were allowed to run on a motorized treadmill 5 days/week for 4 weeks at a speed of 10 rpm/min, with LPS (0.1 mg/kg) intraperitoneally injected once a week for 4 weeks. We found that aerobic exercise ameliorated memory impairment and cognitive deficits among the amnesic mice. Correspondingly, aerobic exercise significantly increased the protein expressions of FNDC5, which activates target neuroprotective markers BDNF and CREB, and antioxidant markers Nrf2/HO-1, leading to inhibiting microglial-mediated neuroinflammation and reduced the expression of BACE-1 in the hippocampus and cerebral cortex of amnesic mice. We estimated that aerobic exercise inhibited neuroinflammation in part through the action of FNDC5/irisin on microglial cells. Therefore, we explored the anti-inflammatory effects of irisin on LPS-stimulated BV-2 microglial cells. In the in vitro experiment, irisin treatment blocked NF-κB/MAPK/IRF3 signaling activation concomitantly with the significantly lowered levels of the LPS-induced iNOS and COX-2 elevations and promotes the Nrf2/HO-1 expression in the LPS-stimulated BV-2 microglial cells. Together, our findings suggest that aerobic exercise can improve the spatial learning ability and cognitive functions of LPS-treated mice by inhibiting microglia-mediated neuroinflammation through its effect on the expression of BDNF/FNDC5/irisin.

Neuroinflammation and Acetylcholinesterase Inhibitory Potentials of a Spiroketal-Enol Ether Polyyne Isolated from Artemisia pallens Wall. ex DC.

Artemisia pallens Wall. ex DC (Asteraceae) is cultivated for the production of high-value essential oil from its aerial biomass. In this study, the chemical composition of the root (crop-residue) essential oil was investigated for the first time, using column-chromatography, GC-FID, GC-MS, LC-QTOF, and NMR techniques, which led to the identification of twenty constituents, with isolation of (E)-2-(2',4'-hexadiynylidene)-1,6-dioxaspiro [4.5]dec-3-ene (D6). The D6 was evaluated in vitro for neuroinflammation and acetylcholinesterase inhibitory potential. It showed inhibition of neuroinflammation in a concentration-dependent manner with significant inhibition of pro-inflammatory cytokines (TNF-α and IL-6) in LPS-stimulated BV2 microglial cells. D6 did not have any significant effect on the viability of the cells at the therapeutic concentrations. D6 also has shown acetylcholinesterase inhibitory potential (51.90±1.19 %) at the concentration of log 106 nM. The results showed that D6 has a potential role in the resolution of neuroinflammation, and its acetylcholinesterase inhibitory potential directs further investigation of its role in the management of Alzheimer's disease-related pathogenesis.

JE-133 Suppresses LPS-Induced Neuroinflammation Associated with the Regulation of JAK/STAT and Nrf2 Signaling Pathways.

Neuroinflammation plays an important role in the pathogenesis of neurodegenerative diseases, and interrupting the microglial-mediated neuroinflammation has been suggested as a promising strategy to delay or prevent the progression of neurodegeneration. In this study, we investigated the effects of JE-133, an optically active isochroman-2H-chromene conjugate containing a 1,3-disubstituted isochroman unit, on lipopolysaccharide (LPS)-induced microglial neuroinflammation and underlying mechanisms both in vitro and in vivo. First, JE-133 treatment decreased LPS-induced overproduction of interleukin-1 beta (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), nitrite, and nitric oxide synthase (iNOS) in BV2 microglial cells. Further study revealed that JE-133 downregulated the phosphorylation level of JAK/STAT and upregulated the protein level of Nrf2/HO-1 in LPS-stimulated BV2 microglial cells and verified that JE-133 directly bound to Keap1 by a pull-down assay. Next, JE-133 administration also inhibited neuroinflammation in vivo, as indicated by a reduced CD11b protein level and an overexpressed mRNA level of the pro-inflammatory cytokine TNF-α in the hippocampus of LPS-injected mice. Moreover, the regulative effects of JE-133 on the JAK/STAT and Nrf2/HO-1 pathways were also verified in the hippocampus of LPS-injected mice. Taken together, our study for the first time reports that JE-133 exhibits inhibitory effects against LPS-stimulated neuroinflammation both in vitro and in vivo, which might be associated with the simultaneous regulation of the JAK/STAT and Nrf2 pathways. Our findings may provide important clues for the discovery of effective drug leads/candidates against neuroinflammation-associated neurodegeneration.

A new anti-neuroinflammation labdane diterpenoid from Salvia tricuspis.

One new labdane diterpenoid, tricuspion A (1), as well as five known triterpenoids (2-6) were isolated from Salvia tricuspis Franch (family Labiatae). The structure of tricuspion A was identified by extensive spectroscopic analysis and by comparison with previously reported data. Compounds 1-6 were evaluated for their inhibitory effects on the NO production in LPS-stimulated BV-2 microglia cells, and 1 exhibited potent inhibitory activity with IC50 value of 14.92 ± 0.51 μM. Compound 1 might exert anti-neuroinflammatory activity through inhibiting the excessive production of NO and down-regulating the protein expression of iNOS and COX-2. As such, labdane diterpenoid (tricuspion A) could provide promising anti-neuroinflammatory lead compound for further structural modification.

Electroacupuncture alleviates neuropathic pain caused by SNL by promoting M2 microglia polarization through PD-L1

As a common clinical disease, neuropathic pain is difficult to be cured with drugs. The occurrence and progression of pain is closely related to the response of spinal microglia. Aspartof the regulation of microglialactivity,PD-L1 playsacriticalrole. Loss of PD-L1 promoted the polarization of M1-like microglia. Increased expression of PD-L1 promoted M2-like polarization. Electroacupuncture has a significant analgesic effect in clinical practice, but its specific mechanism remains to be further explored. In this study, we verified the role of PD-L1 in EA analgesia and the underlying molecular mechanism through spinal nerve ligation (SNL) in rats and lipopolysaccharide (LPS)-treated BV2 microglial cells. Forbehavioralstudiesofrats,mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) were measured, and spinal cord neuros were examined under transmission electron microscopyto determine changes to their myelin structure. The expression levels of PD-L1 and M1/M2-specific markers in rat spinal cord and BV2 microglial cells were measured by enzyme-linked immunosorbent assay, flow cytometry, immunofluorescence staining and Western blot analysis. Our study showed that EA increased the pain threshold, reduced the destruction of myelin structure, promoted the expression of PD-L1 and PD-1, inhibited the MAPK signaling pathway, and promoted the conversion of microglial polarization from the M1 phenotype to the M2 phenotype in SNL rats. PD-L1 knockdown reversed these effects of EA. In addition, PD-L1 knockdown activated the MAPK signaling pathway, promoted microglial polarization to the M1 phenotype, decreased the expression of anti-inflammatory mediators and increased the expression of proinflammatory factors in LPS-stimulated BV2 microglial cells. Our results showed that EA may regulate the excitability of primary afferent neurons through PD-L1 and then inhibit the MAPK signaling pathway to promote the transformation of activated M1 microglia into M2 microglia, reduce inflammatory reactions, and finally achieve analgesic effects. A therapy targeting PD-L1 may be an effective strategy for treating neuropathic pain.

Honokiol-Rich Magnolia officinalis Bark Extract Attenuates Trauma-Induced Neuropathic Pain.

Neuropathic pain (NP) affects about 8% of the general population. Current analgesic therapies have limited efficacy, making NP one of the most difficult to treat pain conditions. Evidence indicates that excessive oxidative stress can contribute to the onset of chronic NP and several natural antioxidant compounds have shown promising efficacy in NP models. Thus, this study aimed to investigate the pain-relieving activity of honokiol (HNK)-rich standardized extract of Magnolia officinalis Rehder & E. Wilson bark (MOE), well known for its antioxidant and anti-inflammatory properties, in the spared nerve injury (SNI) model. The molecular mechanisms and efficacy toward neuroinflammation were investigated in spinal cord samples from SNI mice and LPS-stimulated BV2 microglia cells. MOE and HNK showed antioxidant activity. MOE (30 mg/kg p.o.) produced an antiallodynic effect in SNI mice in the absence of locomotor impairment, reduced spinal p-p38, p-JNK1, iNOS, p-p65, IL-1ß, and Nrf2 overexpression, increased IL-10 and MBP levels and attenuated the Notch signaling pathway by reducing Jagged1 and NEXT. These effects were prevented by the CB1 antagonist AM251. HNK reduced the proinflammatory response of LPS-stimulated BV2 and reduced Jagged1 overexpression. MOE and HNK, by modulating oxidative and proinflammatory responses, might represent interesting candidates for NP management.

Dexmedetomidine attenuates neuroinflammation and microglia activation in LPS-stimulated BV2 microglia cells through targeting circ-Shank3/miR-140-3p/TLR4 axis.

It has been shown that dexmedetomidine (Dex) could attenuate postoperative cognitive dysfunction (POCD) via targeting circular RNAs (circRNAs). Circ-Shank3 has been found to be involved in the neuroprotective effects of Dex against POCD. However, the role of circ-Shank3 in POCD remains largely unknown. Reverse transcription quantitative PCR (RT-qPCR) was performed to detect circ-Shank3 and miR-140-3p levels in lipopolysaccharide (LPS)-treated microglia BV-2 cells in the absence or presence of Dex. The relationship among circ-Shank3, miR-140-3p and TLR4 was confirmed by dual-luciferase reporter assay. Additionally, Western blot and immunofluorescence (IF) assays were conducted to evaluate TLR4, p65 and Iba-1 or CD11b levels in cells. In this study, we found that Dex notably decreased circ-Shank3 and TLR4 levels and elevated miR-140-3p level in LPS-treated BV2 cells. Mechanistically, circ-Shank3 harbor miR-140-3p, functioning as a miRNA sponge, and then miR-140-3p targeted the 3'-UTR of TLR4. Additionally, Dex treatment significantly reduced TLR4 level and phosphorylation of p65, and decreased the expressions of microglia markers Iba-1 and CD11b in LPS-treated BV2 cells. As expected, silenced circ-Shank3 further reduced TLR4, p65 and Iba-1 and CD11b levels in LPS-treated BV2 cells in the presence of Dex, whereas these phenomena were reversed by miR-140-3p inhibitor. Collectively, our results found that Dex could attenuate the neuroinflammation and microglia activation in BV2 cells exposed to LPS via targeting circ-Shank3/miR-140-3p/TLR4 axis. Our results might shed a new light on the mechanism of Dex for the treatment of POCD.

Glycyrrhizae Radix suppresses lipopolysaccharide- and diazepam-induced nerve inflammation in the hippocampus, and contracts the duration of pentobarbital- induced loss of righting reflex in a mouse model

Nerve inflammation is linked to the development of various neurological disorders. This study aimed to examine whether Glycyrrhizae Radix effectively influences the duration of the pentobarbital-induced loss of righting reflex, which may increase in a mouse model of lipopolysaccharide (LPS)-induced nerve inflammation and diazepam-induced γ-aminobutyric acid receptor hypersensitivity. Furthermore, we examined the anti-inflammatory effects of Glycyrrhizae Radix extract on LPS-stimulated BV2 microglial cells, in vitro. Treatment with Glycyrrhizae Radix significantly decreased the duration of pentobarbital-induced loss of righting reflex in the mouse model. Furthermore, treatment with Glycyrrhizae Radix significantly attenuated the LPS-induced increases in interleukin-1β, interleukin-6, and tumor necrosis factor-alpha at the mRNA level, and it significantly reduced the number of ionized calcium-binding adapter molecule-1-positive cells in the hippocampal dentate gyrus 24h after LPS treatment. Treatment with Glycyrrhizae Radix also suppressed the release of nitric oxide, interleukin-1β, interleukin-6, and tumor necrosis factor protein in culture supernatants of LPS-stimulated BV2 cells. In addition, glycyrrhizic acid and liquiritin, active ingredients of Glycyrrhizae Radix extract, reduced the duration of pentobarbital-induced loss of righting reflex. These findings suggest that Glycyrrhizae Radix, as well as its active ingredients, glycyrrhizic acid and liquiritin, may be effective therapeutic agents for the treatment of nerve inflammation-induced neurological disorders.

Molecular Mechanisms of the Anti-Inflammatory Effects of Epigallocatechin 3-Gallate (EGCG) in LPS-Activated BV-2 Microglia Cells.

Chronic neuroinflammation is associated with many neurodegenerative diseases, such as Alzheimer's. Microglia are the brain's primary immune cells, and when activated, they release various proinflammatory cytokines. Several natural compounds with anti-inflammatory and antioxidant properties, such as epigallocatechin 3-gallate (EGCG), may provide a promising strategy for inflammation-related neurodegenerative diseases involving activated microglia cells. The objective of the current study was to examine the molecular targets underlying the anti-inflammatory effects of EGCG in activated microglia cells. BV-2 microglia cells were grown, stimulated, and treated with EGCG. Cytotoxicity and nitric oxide (NO) production were evaluated. Immunoassay, PCR array, and WES™ Technology were utilized to evaluate inflammatory, neuroprotective modulators as well as signaling pathways involved in the mechanistic action of neuroinflammation. Our findings showed that EGCG significantly inhibited proinflammatory mediator NO production in LPS-stimulated BV-2 microglia cells. In addition, ELISA analysis revealed that EGCG significantly decreases the release of proinflammatory cytokine IL-6 while it increases the release of TNF-α. PCR array analysis showed that EGCG downregulated MIF, CCL-2, and CSF2. It also upregulated IL-3, IL-11, and TNFS10. Furthermore, the analysis of inflammatory signaling pathways showed that EGCG significantly downregulated mRNA expression of mTOR, NF-κB2, STAT1, Akt3, CCL5, and SMAD3 while significantly upregulating the expression of mRNA of Ins2, Pld2, A20/TNFAIP3, and GAB1. Additionally, EGCG reduced the relative protein expression of NF-κB2, mTOR, and Akt3. These findings suggest that EGCG may be used for its anti-inflammatory effects to prevent neurodegenerative diseases.

Anti-inflammatory activity of Kyungok-go on Lipopolysaccharide-Stimulated BV-2 Microglia Cells

Objectives: Kyungok-go (KOG) is a traditional multi-herbal medicine commonly used for enforcing weakened immunity for long time. Recently, there are several reports that KOG has anti-inflammatory and immuno-stimulatory activities in many experimental models. However, the protective effects of KOG on neuronal inflammation are still undiscovered. Thus, we investigated the neuro-protective activity of KOG on lipopolysaccharide (LPS)-stimulated mouse microglia cells. To find out KOG’s anti-neuroinflammatory effects on microglial cells, we examined the production of nitrite using griess assay, and mRNA expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2 and interleukin (IL)-1<i>β</i>, IL-6, tumor necrosis factor (TNF)-<i>α</i> using real time RT-PCR. In addition, to examine the regulating mechanisms of KOG, we investigated the protein expression of mitogen-activated protein kinases (MAPKs) and I<i>κ</i>-B<i>α</i> by western blot. KOG inhibited the elevation of nitrite, iNOS and COX-2 on LPS-stimulated BV2 cells. Also, KOG significantly inhibited the pro-inflammatory cytokines such as IL-1<i>β</i>, IL-6, and TNF-<i>α</i> on LPS-stimulated BV2 microglial cells. Moreover, KOG inhibited the activation of c-Jun N-terminal kinase (JNK), P38 and degradation of I<i>κ</i>-B<i>α</i> but not the activation of extracellular signal regulated kinase (ERK) on LPS-stimulated BV2 microglial cells. These results showed KOG has the anti-inflammatory effects through the inhibition on nitrite, iNOS, COX-2, IL-1<i>β</i>, IL-6, and TNF-<i>α</i> via the deactivation of JNK, p38 and nuclear factor (NF)-<i>κ</i>B on LPS-stimulated BV2 microglial cells. Thereby, KOG could offer the new and promising treatment for neurodegenerative disease related to neuroinflammation.