Rhein inhibits M1 polarization of BV2 microglia through MAPK/IκB signalling pathway and reduces neurotoxicity caused by neuroinflammation.

BACKGROUND: Rhein is an anthraquinone compound with anti-inflammatory pharmacological activity. It has been found to play a neuroprotective role in neurological diseases, but the neuroprotective mechanism of rhein remains unclear. METHODS: SH-SY5Y cells serving as neuron-like cells and BV2 microglia were used. The toxicity of rhein on BV2 microglia and the viability of SH-SY5Y cells were measured by CCK-8 assay. The mRNA expression and secretion of pro-inflammatory cytokines were detected by qPCR and ELISA. Iba1, CD86 and pathway signalling protein in BV2 microglia were assessed by Western blot and immunofluorescence. Apoptosis of SH-SY5Y cells exposed to neuroinflammation was analysed through flow cytometry. RESULTS: Rhein inhibited MAPK/IκB signalling pathways. Further studies revealed that rhein inhibited the production of pro-inflammatory cytokines TNF-α, IL-6, IL-1ß and iNOS in BV2 cells and also inhibited the expression of M1 polarization markers Iba1 and CD86 in BV2 cells. Furthermore, rhein reduced the apoptotic rate and restored cell viability of SH-SY5Y cells exposed to neuroinflammation. CONCLUSIONS: Our study demonstrated that rhein inhibited microglia M1 polarization via MAPK/IκB signalling pathway and protected nerve cells through suppressing neuroinflammation.

Characteristic terpenylated coumarins from Ferula ferulaeoides as potential inhibitors on overactivation of microglia.

A total of 37 characteristic terpenylated coumarins (1-25), including 17 undescribed compounds (1-5, 6a/6b, 7-10, 11a/11b-13a/13b), have been isolated from the root of Ferula ferulaeoides. Meanwhile, twelve pairs of enantiomers (6a/6b, 11a/11b-15a/15b, 17a/17b, 18a/18b, 20a/20b-22a/22b, and 25a/25b) were chirally purified. The structures of these new compounds were elucidated using HRESIMS, UV, NMR, and calculated 13C NMR with a custom DP4 + analysis. The absolute configurations of all the compounds were determined for the first time using electronic circular dichroism (ECD). Then, their inhibitory effects on nitric oxide (NO) production were evaluated with LPS-induced BV-2 microglia. Compared with the positive control minocycline (IC50 = 59.3 µM), ferulaferone B (2) exhibited stronger inhibitory potency with an IC50 value of 12.4 µM. The immunofluorescence investigation indicated that ferulaferone B (2) could inhibit Iba-1 expression in LPS-stimulated BV-2 microglia.

Effects of environmentally relevant concentration of short-chain chlorinated paraffins on BV2 microglia activation and lipid metabolism, implicating altered neurogenesis.

Short-chain chlorinated paraffins (SCCPs), a class of persistent organic pollutants, have been found to cause diverse organ and systemic toxicity. However, little is known about their neurotoxic effects. In this study, we exposed BV2, a mouse microglia cell line, to environmentally relevant concentration of SCCPs (1 µg/L, 10 µg/L, 100 µg/L) for 24 h to investigate their impacts on the nervous system. Our observations revealed that SCCPs induced the activation of BV2 microglia, as indicated by altered morphology, stimulated cell proliferation, enhanced phagocytic and migratory capabilities. Analysis at the mRNA level confirmed the activation status, with the downregulation of TMEM119 and Tgfbr1, and upregulation of Iba1 and CD11b. The upregulated expression of genes such as cenpe, mki67, Axl, APOE and LPL also validated alterations in cell functions. Moreover, BV2 microglia presented an M2 alternative phenotype upon SCCPs exposure, substantiated by the reduction of NF-κB, TNF-α, IL-1ß, and the elevation of TGF-ß. Additionally, SCCPs caused lipid metabolic changes in BV2 microglia, characterized by the upregulations of long-chain fatty acids and acylcarnitines, reflecting an enhancement of ß-oxidation. This aligns with our findings of increased ATP production upon SCCPs exposure. Intriguingly, cell activation coincided with elevated levels of omega-3 polyunsaturated fatty acids. Furthermore, activated microglial medium remarkably altered the proliferation and differentiation of mouse neural stem cells. Collectively, exposure to environmentally relevant concentrations of SCCPs resulted in activation and lipid metabolic alterations in BV2 microglia, potentially impacting neurogenesis. These findings provide valuable insights for further research on the neurotoxic effect of SCCPs.

Edaravone dexborneol promotes M2 microglia polarization against lipopolysaccharide-induced inflammation via suppressing TLR4/MyD88/NF-κB pathway.

Edaravone dexborneol (ED) is a novel neuroprotective compound that consists of two active ingredients, edaravone and ( +)-borneol in a 4:1 ratio, which has been shown the anti-inflammatory properties in animal models of ischemic stroke, cerebral hemorrhage, and autoimmune encephalomyelitis. However, the effect of ED on the polarization of microglia in neuroinflammation has not been elucidated. This study was to investigate the effects of ED on the polarization of microglia induced by lipopolysaccharide (LPS) and potential mechanisms. BV-2 microglial cells were incubated with ED (100, 200, and 400 µM) for 2 h, followed by lipopolysaccharide (LPS, 1 µg/ml) for 12 h. The researchers used the Griess method, western blot, immunocytochemistry, and subcellular fractionation to assess the effects and potential mechanisms of ED on neuroinflammatory reactions. The expression of ROS and the activities of antioxidant enzymes (SOD, GPx, and CAT) in LPS-induced BV-2 cells were also measured using the DCFH-DA fluorescent probe and colorimetric methods, respectively. It was observed that ED significantly declined the levels of TLR4/NF-κB pathway-associated proteins (TLR4, MyD88, p65, p-p65, IκBα, p-IκBα, IKKß, p-IKKß) and therefore inhibited LPS-induced production of NO, IL-1ß, and TNF-α. Moreover, ED markedly downregulated the M1 marker (iNOS) and upregulated the M2 marker (Arginase-1, Ym-1). In addition, ED also reduced ROS generation and enhanced GPx activity. ED induced the polarization of LPS-stimulated microglia from M1 to M2 against inflammation by negatively regulating the TLR4/MyD88/NF-κB signaling pathway. Additionally, ED performed antioxidative function by depleting the intracellular excessive ROS caused by LPS through the enhancement of the enzymatic activity of GPx. ED may be a potential agent to attenuate neuroinflammation via regulating the polarization of microglia.

Human ß-Defensin 3 Inhibition of P. gingivalis LPS-Induced IL-1ß Production by BV-2 Microglia through Suppression of Cathepsins B and L.

Cathepsin B (CatB) is thought to be essential for the induction of Porphyromonas gingivalis lipopolysaccharide (Pg LPS)-induced Alzheimer's disease-like pathologies in mice, including interleukin-1ß (IL-1ß) production and cognitive decline. However, little is known about the role of CatB in Pg virulence factor-induced IL-1ß production by microglia. We first subjected IL-1ß-luciferase reporter BV-2 microglia to inhibitors of Toll-like receptors (TLRs), IκB kinase, and the NLRP3 inflammasome following stimulation with Pg LPS and outer membrane vesicles (OMVs). To clarify the involvement of CatB, we used several known CatB inhibitors, including CA-074Me, ZRLR, and human ß-defensin 3 (hBD3). IL-1ß production in BV-2 microglia induced by Pg LPS and OMVs was significantly inhibited by the TLR2 inhibitor C29 and the IκB kinase inhibitor wedelolactonne, but not by the NLRPs inhibitor MCC950. Both hBD3 and CA-074Me significantly inhibited Pg LPS-induced IL-1ß production in BV-2 microglia. Although CA-074Me also suppressed OMV-induced IL-1ß production, hBD3 did not inhibit it. Furthermore, both hBD3 and CA-074Me significantly blocked Pg LPS-induced nuclear NF-κB p65 translocation and IκBα degradation. In contrast, hBD3 and CA-074Me did not block OMV-induced nuclear NF-κB p65 translocation or IκBα degradation. Furthermore, neither ZRLR, a specific CatB inhibitor, nor shRNA-mediated knockdown of CatB expression had any effect on Pg virulence factor-induced IL-1ß production. Interestingly, phagocytosis of OMVs by BV-2 microglia induced IL-1ß production. Finally, the structural models generated by AlphaFold indicated that hBD3 can bind to the substrate-binding pocket of CatB, and possibly CatL as well. These results suggest that Pg LPS induces CatB/CatL-dependent synthesis and processing of pro-IL-1ß without activation of the NLRP3 inflammasome. In contrast, OMVs promote the synthesis and processing of pro-IL-1ß through CatB/CatL-independent phagocytic mechanisms. Thus, hBD3 can improve the IL-1ß-associated vicious inflammatory cycle induced by microglia through inhibition of CatB/CatL.

Ferroptosis mediated by TNFSF9 interferes in acute ischaemic stroke reperfusion injury with the progression of acute ischaemic stroke.

In this study, we investigated the potential involvement of TNFSF9 in reperfusion injury associated with ferroptosis in acute ischaemic stroke patients, mouse models and BV2 microglia. We first examined TNFSF9 changes in peripheral blood from stroke patients with successful reperfusion, and constructed oxygen-glucose deprivation-reperfusion (OGD-R) on BV2 microglia, oxygen-glucose deprivation for 6 h followed by reoxygenation and re-glucose for 24 h, and appropriate over-expression or knockdown of TNFSF9 manipulation on BV2 cells and found that in the case of BV2 cells encountering OGD-R over-expression of TNFSF9 resulted in increased BV2 apoptosis. Still, the knockdown of TNFSF9 ameliorated apoptosis and ferroptosis. In an in vivo experiment, we constructed TNFSF9 over-expression or knockout mice by intracerebral injection of TNFSF9-OE or sh-TNFSF9 adenovirus. We performed the middle cerebral artery occlusion (MCAO) model on day four, 24 h after ligation of the proximal artery, for half an hour to recanalize. As luck would have it, over-expression of TNFSF9 resulted in increased brain infarct volumes, neurological function scores and abnormalities in TNFSF9-related TRAF1 and ferroptosis-related pathways, but knockdown of TNFSF9 improved brain infarcts in mice as well as reversing TNFSF9-related signalling pathways. In conclusion, our data provide the first evidence that TNFSF9 triggers microglia activation by activating the ferroptosis signalling pathway following ischaemic stroke, leading to brain injury and neurological deficits.

Fatsia japonica extract exerts antioxidant and anti-neuroinflammatory effects on neuronal cells and a zebrafish model.

ETHNOPHARMACOLOGICAL RELEVANCE: Fatsia japonica is a traditional medicine used to treat various diseases, including inflammation-related disorders. However, its antineuroinflammatory and neuroprotective effects remain unclear. AIM OF THE STUDY: We aimed to evaluate the anti-neuroinflammatory and neuroprotective effects of F. japonica extract to identify the underlying mechanisms. MATERIALS AND METHODS: The components of F. japonica extract were profiled using ultra-high-performance liquid chromatography-mass spectrometry. The effects of F. japonica extract were investigated in BV2 microglia and HT22 hippocampal cells. Furthermore, in vivo effects of F. japonica extract were assessed using zebrafish models treated with H2O2 and LPS to evaluate the effects of in vivo. RESULTS: We identified 27 compounds in the F. japonica extract. F. japonica extract demonstrated anti-inflammatory properties by suppressing LPS-induced inflammatory responses in both BV2 cells and zebrafish, along with inhibiting the activation of the nuclear factor (NF)-κB (p65) pathway. The protective effects of this extract were also observed on glutamate-treated HT22 cells and in H2O2-induced zebrafish. Furthermore, F. japonica extract upregulated nuclear factor E2-related (Nrf) 2/heme oxygenase (HO)-1 expression in BV2 and HT22 cells. CONCLUSIONS: F. japonica extract exerted anti-neuroinflammatory and neuroprotective effects through Nrf2/HO-1 and the NF-κB pathway.

Anti-inflammatory effects of ulinastatin in lps-induced bv2 cells by a20: implications for sports and fitness players' health

This study delves into the anti-inflammatory role of ulinastatin (UTI) in BV2 microglia cells stimulated with lipopolysaccharide (LPS), focusing on its relevance to sports and fitness players. A crucial aspect of athletic health is managing inflammation, which can impact performance and recovery. We constructed an inflammatory response model in BV2 microglia using LPS and divided the sample into four groups (n=12 each): a control group (C), an LPS-induced inflammation group (L), a UTI treatment group (U+L), and a group with A20 protein down-regulation (U+L+Si). The study evaluated IL-1β and TNF-α protein concentrations via ELISA, NF-κB/P65 and A20 protein expressions through Western blot, and microglial Iba-1 expression via immunofluorescence staining. Compared to the control, the L and U+L+Si groups showed significant increases in IL-1β, TNF-α, NF-κB P65 expression, and decreased A20 protein expression (P<0.05). The L and U+L+Si groups also exhibited higher levels of IL-1β, TNF-α, NF-κB P65, and Iba-1 compared to the U+L group (P<0.05), with reduced A20 expression. Interestingly, the U+L group displayed no significant differences in IL-1β, TNF-α, and NF-κB P65 compared to the control (P>0.05). The findings suggest that UTI significantly mitigates LPS-induced inflammation in BV2 microglia, primarily through upregulation of A20 protein. For athletes and fitness enthusiasts, these insights offer potential strategies for managing exercise-induced inflammation, enhancing recovery, and optimizing performance (AU)

Mechanism of ligusticum cycloprolactam against neuroinflammation based on network pharmacology and experimental verification.

Ligustilide, a natural phthalide mainly derived from chuanxiong rhizomes and Angelica Sinensis roots, possesses anti-inflammatory activity, particularly in the context of the nervous system. However, its application is limited because of its unstable chemical properties. To overcome this limitation, ligusticum cycloprolactam (LIGc) was synthesized through structural modification of ligustilide. In this study, we combined network pharmacological methods with experimental verification to investigate the anti-neuroinflammatory effects and mechanisms of ligustilide and LIGc. Based on our network pharmacology analysis, we identified four key targets of ligustilide involved in exerting an anti-inflammatory effect, with the nuclear factor (NF)-κB signal pathway suggested as the main signalling pathway. To verify these results, we examined the expression of inflammatory cytokines and inflammation-related proteins, analysed the phosphorylation level of NF-κB, inhibitor of κBα (IκBα) and inhibitor of κB kinase α and ß (IKKα+ß), and evaluated the effect of BV2 cell-conditioned medium on HT22 cells in vitro. Our results, demonstrate for the first time that LIGc can downregulate the activation of the NF-κB signal pathway in BV2 cells induced by lipopolysaccharide, suppress the production of inflammatory cytokines and reduce nerve injury in HT22 cells mediated by BV2 cells. These findings suggest that LIGc inhibits the neuroinflammatory response mediated by BV2 cells, providing strong scientific support for the development of anti-inflammatory drugs based on natural ligustilide or its derivatives. However, there are some limitations to our current study. In the future, further experiments using in vivo models may provide additional evidence to support our findings.

Study on Components with Anti-Neuroinflammatory Activities from Caragana microphylla Lam.

Caragana microphylla Lam., is a perennial herb in the genus Caragana in the Fabaceae family. Two undescribed triterpenoid saponins (1-2), along with thirty-five known components (3-37) were obtained from the roots of C. microphylla Lam. These compounds were identified using physicochemical analyses and various spectroscopic methods. The anti-neuroinflammatory activities were evaluated by measuring the inhibition of nitric oxide (NO) production in lipopolysaccharide (LPS)-induced BV-2 microglial cells. Compared with positive control minocycline, compounds 10, 19, and 28 exhibited significant effects with IC50 values of 14.04, 19.35 and 10.20 µM, respectively.

Anti-Neuroinflammatory and Neuroprotective Effect of Intermedin B Isolated from the Curcuma longa L. via NF-κB and ROS Inhibition in BV2 Microglia and HT22 Hippocampal Cells.

Compounds derived from Curcuma longa L. (C. longa) have been extensively studied and reported to be effective and safe for the prevention and treatment of various diseases, but most research has been focused on curcuminoids derived from C. longa. As neurodegenerative diseases are associated with oxidation and inflammation, the present study aimed to isolate and identify active compounds other than curcuminoids from C. longa to develop substances to treat these diseases. Seventeen known compounds, including curcuminoids, were chromatographically isolated from the methanol extracts of C. longa, and their chemical structures were identified using 1D and 2D NMR spectroscopy. Among the isolated compounds, intermedin B exhibited the best antioxidant effect in the hippocampus and anti-inflammatory effect in microglia. Furthermore, intermedin B was confirmed to inhibit the nuclear translocation of NF-κB p-65 and IκBα, exerting anti-inflammatory effects and inhibiting the generation of reactive oxygen species, exerting neuroprotective effects. These results highlight the research value of active components other than curcuminoids in C. longa-derived compounds and suggest that intermedin B may be a promising candidate for the prevention of neurodegenerative diseases.

Protective Effect of Ferulic Acid on Lipopolysaccharide-Induced BV2 Microglia Inflammation via AMPK/mTOR Signaling Pathway.

In neurodegenerative diseases, microglial activation and neuroinflammation are essential for the control and progression of neurodegenerative diseases. Mitigating microglium-induced inflammation is one strategy for hindering the progression of neurodegenerative diseases. Ferulic acid (FA) is an effective anti-inflammatory agent, but its potential role and regulation mechanism in neuroinflammatory reactions have not been fully studied. In this study, the neuroinflammation model was established by lipopolysaccharide (LPS), and the inhibitory effect of FA on neuroinflammation of BV2 microglia was studied. The results showed that FA significantly reduced the production and expression of reactive oxygen species (ROS), tumor necrosis factor-α (TNF-α), leukocyte-6 (IL-6) and interleukin-1ß (IL-1ß). We further studied the mechanism of FA's regulation of LPS-induced BV2 neuroinflammation and found that FA can significantly reduce the expression of mTOR in BV2 microglia induced by LPS, and significantly increase the expression of AMPK, indicating that FA may have an anti-inflammatory effect by activating the AMPK/mTOR signaling pathway to regulate the release of inflammatory mediators (such as NLRP3, caspase-1 p20 and IL-1ß). We further added an autophagy inhibitor (3-MA) and an AMPK inhibitor (compound C, CC) for reverse verification. The results showed that FA's inhibitory effects on TNF-α, IL-6 and IL-1ß and its regulatory effect on AMPK/mTOR were destroyed by 3-MA and CC, which further indicated that FA's inhibitory effect on neuroinflammation is related to its activation of the AMPK/mTOR autophagy signaling pathway. In a word, our experimental results show that FA can inhibit LPS-induced neuroinflammation of BV2 microglia by activating the AMPK/mTOR signaling pathway, and FA may be a potential drug for treating neuroinflammatory diseases.

Combined with UPLC-Triple-TOF/MS-based plasma lipidomics and molecular pharmacology reveals the mechanisms of schisandrin against Alzheimer's disease.

BACKGROUND: Alzheimer's disease (AD), a type of neurodegeneration disease, is characterized by Aß deposition and tangles of nerve fibers. Schisandrin is one of the main components of Fructus Schisandrae Chinensis. Researches showed that schisandrin can improve the cognitive impairment and memory of AD mice, but the specific mechanism has not been fully elucidated. PURPOSE: The purpose of this study is to investigate the possible mechanism of schisandrin in improving AD pathology. METHODS: The Morris water maze test was executed to detect spatial learning and memory. Ultra performance liquid chromatography-Triple time of flight mass spectrometry (UPLC-Triple-TOF/MS)-based plasma lipidomics was used to study the changes of plasma lipids. Moreover, we measured the levels of protein and mRNA expression of APOE and ABCA1 in the rat brains and in BV2 microglia. RESULTS: Our study found that schisandrin could improve learning and memory, and reduce Aß deposition in AD rats. Furthermore, we found that schisandrin can improve plasma lipid metabolism disorders. Therefore, we hypothesized schisandrin might act via LXR and the docking results showed that schisandrin interacts with LXRß. Further, we found schisandrin increased the protein and mRNA expression of LXR target genes APOE and ABCA1 in the brain of AD rats and in BV2 microglia. CONCLUSION: Our study reveals the neuroprotective effect and mechanism of schisandrin improves AD pathology by activating LXR to produce APOE and ABCA1.

NOX2 inhibition enables retention of the circadian clock in BV2 microglia and primary macrophages.

Introduction: Sustained neuroinflammation is a major contributor to the progression of neurodegenerative diseases such as Alzheimer's (AD) and Parkinson's (PD) diseases. Neuroinflammation, like other cellular processes, is affected by the circadian clock. Microglia, the resident immune cells in the brain, act as major contributors to neuroinflammation and are under the influence of the circadian clock. Microglial responses such as activation, recruitment, and cytokine expression are rhythmic in their response to various stimuli. While the link between circadian rhythms and neuroinflammation is clear, significant gaps remain in our understanding of this complex relationship. To gain a greater understanding of this relationship, the interaction between the microglial circadian clock and the enzyme NADPH Oxidase Isoform 2 (NOX2) was studied; NOX2 is essential for the production of reactive oxygen species (ROS) in oxidative stress, an integral characteristic of neuroinflammation. Methods: BV2 microglia were examined over circadian time, demonstrating oscillations of the clock genes Per2 and Bmal1 and the NOX2 subunits gp91phox and p47phox. Results: The BV2 microglial clock exerted significant control over NOX2 expression and inhibition of NOX2 enabled the microglia to retain a functional circadian clock while reducing levels of ROS and inflammatory cytokines. These trends were mirrored in mouse bone marrow-derived primary macrophages. Conclusions: NOX2 plays a crucial role in the interaction between the circadian clock and the activation of microglia/macrophages into their pro-inflammatory state, which has important implications in the control of neuroinflammation.

Sinapic Acid Attenuates the Neuroinflammatory Response by Targeting AKT and MAPK in LPS-Activated Microglial Models.

Sinapic acid (SA) is a phenolic acid that is widely distributed in fruits and vegetables, which has various bioactivities, such as antidiabetic, anticancer and anti-inflammatory functions. Over-activated microglial is involved in the development progress of neurodegenerative diseases, such as Parkinson's disease and Alzheimer's disease. The objective of this study was to investigate the effect of SA in microglia neuroinflammation models. Our results demonstrated that SA inhibited secretion of the nitric oxide (NO) and interleukin (IL)-6, reduced the expression of inducible nitric oxide synthase (iNOS) and enhanced the release of IL-10 in a dose-dependent manner. Besides, our further investigation revealed that SA attenuated the phosphorylation of AKT and MAPK cascades in LPS-induced microglia. Consistently, oral administration of SA in mouse regulated the production of inflammation-related cytokines and also suppressed the phosphorylation of MAPK cascades and AKT in the mouse cerebral cortex. These results suggested that SA may be a possible therapy candidate for anti-inflammatory activity by targeting the AKT/MAPK signaling pathway.

Protective effect of platelet-rich plasma on LPS-induced neuroinflammation in BV2 microglia through NRF2/HO-1 pathway / 中国输血杂志

【Objective】 To investigate the protective effect and mechanism of platelet-rich plasma (PRP) on lipopolysaccharide (LPS) -induced inflammatory response in BV2 cells. 【Methods】 BV2 microglia were divided into normal control group, 10%PRP control group, LPS group (LPS induction), 3%PRP+ LPS group (LPS induction, 3%PRP pretreatment), 5%PRP+ LPS group (LPS induction, 5%PRP pretreatment), 10%PRP+ LPS group (LPS induction, 10%PRP pretreatment), and the proliferation of BV2 cells was measured by CCK-8. The mitochondrial membrane potential of BV2 cells was measured by confocal microscopy, ROS was measured by fluorescence method, and NO was measured by Griess method. The protein expressions of IL-6, TNF-α, BACH1, GPX4, NRF2 and HO-1 were detected by Western blot. In addition, BV2 microglia were treated with HO-1 inhibitor and divided into normal control group, LPS group, ZnPP+ LPS group, 10%PRP+ LPS group, ZnPP+ LPS+ 10%PRP group, and the protein expressions of HO-1, IL-6 and TNF-α were detected by Western blot. 【Results】 Compared with normal control group, PRP promoted the proliferation of BV2 cells (P<0.01). The mitochondrial membrane potential decreased, ROS production increased, the levels of NO, IL-6, TNF-α and BACH1 increased (P<0.01). However, the expression levels of GPX4, NRF2 and HO-1 decreased (P<0.01) in LPS group. Compared with LPS group, the proliferation activity and mitochondrial membrane potential of BV2 cells in 3%PRP+ LPS, 5%PRP+ LPS and 10%PRP+ LPS groups significantly increased. The levels of ROS, NO, IL-6, TNF-α and BACH1 significantly decreased (P<0.01). The expressions of GPX4, NRF2 and HO-1 in different concentrations of PRP (3%, 5% and 10%) increased (P<0.01). Moreover, the expression of IL-6 and TNF-α in ZnPP+ LPS group was significantly higher than that in LPS group after HO-1 inhibitor treatment. Compared with 10%PRP+ LPS+ ZnPP group, HO-1 inhibitor could reverse the effect of PRP on the expression of IL-6 and TNF-α in LPS-induced BV2 cells (P<0.01). 【Conclusion】 PRP inhibits the inflammatory response of BV2 microglia induced by LPS by activating the NRF2/HO-1 signaling pathway.

Spirulina platensis Suppressed iNOS and Proinflammatory Cytokines in Lipopolysaccharide-Induced BV2 Microglia.

The disease burden of neurodegenerative diseases is on the rise due to the aging population, and neuroinflammation is one of the underlying causes. Spirulina platensis is a well-known superfood with numerous reported bioactivities. However, the effect of S. platensis Universiti Malaya Algae Culture Collection 159 (UMACC 159) (a strain isolated from Israel) on proinflammatory mediators and cytokines remains unknown. In this study, we aimed to determine the anti-neuroinflammatory activity of S. platensis extracts and identify the potential bioactive compounds. S. platensis extracts (hexane, ethyl acetate, ethanol, and aqueous) were screened for phytochemical content and antioxidant activity. Ethanol extract was studied for its effect on proinflammatory mediators and cytokines in lipopolysaccharide (LPS)-induced BV2 microglia. The potential bioactive compounds were identified using liquid chromatography-mass spectrometric (LC-MS) analysis. Ethanol extract had the highest flavonoid content and antioxidant and nitric oxide (NO) inhibitory activity. Ethanol extract completely inhibited the production of NO via the downregulation of inducible NO synthase (iNOS) and significantly reduced the production of tumor necrosis factor (TNF)-α and interleukin (IL)-6. Emmotin A, palmitic amide, and 1-monopalmitin, which might play an important role in cell signaling, have been identified. In conclusion, S. platensis ethanol extract inhibited neuroinflammation through the downregulation of NO, TNF-α and IL-6. This preliminary study provided insight into compound(s) isolation, which could contribute to the development of precision nutrition for disease management.

Polyhydric Stigmastane-Type Steroids Derivative from Vernonia amygdalina and Their Anti-Neuroinflammatory Activity.

Vernonia amygdalina Del. is a traditional medicinal plant and vegetable originating from tropical Africa. The phytochemical investigation of V. amygdalina led to eight undescribed polyhydric stigmastane-type steroids, vernonin M-T (1-8). Their gross structures and stereochemistry were elucidated by HR-ESI-MS, 1D and 2D NMR spectra, X-ray diffraction, quantum chemical computation of the ECD spectrum, and the in situ dimolybdenum CD method. The anti-neuroinflammatory activity of the isolated compounds was performed in BV-2 microglia cells. As a result, compound 1 displayed a notable anti-neuroinflammatory effect via suppressing the LPS-induced IκB degradation and restricting the activation of the PI3K/AKT and p38 MAPK pathways.

Carrageenophyte Kappaphycus malesianus Inhibits Microglia-Mediated Neuroinflammation via Suppression of AKT/NF-κB and ERK Signaling Pathways.

Neuroinflammation is an inflammatory response in any part of the central nervous system triggered by the activation of microglia and astrocytes to produce proinflammatory cytokines in the brain. However, overproduction of proinflammatory cytokines further contributes to the development of neurodegenerative disorders. Red seaweed, Kappaphycus malesianus, is a predominant carrageenophyte commercially cultivated in Semporna, Sabah, Malaysia. It is an important source of raw material for kappa-carrageenan productions in the food, pharmaceutical and cosmetics industries. However, no studies have been conducted focusing on the antineuroinflammatory effects of K. malesianus. The aim of the present study was to investigate the effect of the antineuroinflammatory activity of K. malesianus extracts (ethyl acetate, ethanol and methanol) on lipopolysaccharide-stimulated BV2 microglia and the underlying mechanisms involved in the regulation of neuroinflammatory pathways. Extract with the most promising antineuroinflammatory activity was analyzed using liquid chromatography-mass spectrometry (LC-MS). Our results show that methanol extract has a convincing antineuroinflammatory effect by suppressing both AKT/NF-κB and ERK signaling pathways to inhibit the expression of all proinflammatory cytokines without causing a cytotoxicity effect. LC-MS analysis of methanol extract revealed two compounds: prosopinine and eplerenone. Our findings indicated that metabolites of K. malesianus are potent antineuroinflammatory agents with respect to prevention of neurological disorders.

Sesquiterpene coumarins isolated from Ferula bungeana and their anti-neuroinflammatory activities.

This is the first study to profile natural sesquiterpene coumarins (SCs) in Ferula bungeana, a medicinal plant of the genus Ferula in China. Eight undescribed sesquiterpene coumarins (1-8), along with six known ones (9-14) were obtained from the whole plant of F. bungeana. These unreported SCs (1-8) enriched the structural diversity of natural SCs, especially these with the hydroxy or carbonyl group at C-7' and a hydroperoxy group at C-7' or C-8'. Compounds (9-14) were reported for the first time from this plant. The in vitro anti-neuroinflammatory activity assay showed that compounds 2 and 9 showed stronger inhibitory effect on nitric oxide (NO) production in lipopolysaccharide (LPS)-induced BV-2 microglia, compared with positive control minocycline, and compounds 5 and 10 showed moderate inhibitory effects.