LPS-induced iNOS Expression Research Articles

Panobinostat, a Histone Deacetylase Inhibitor, Reduces LPS-Induced Expression of Inducible Nitric Oxide Synthase in Rat Immortalized Microglia HAPI Cells.

Microglia, resident immune cells in the central nervous system (CNS), play a critical role in maintaining CNS homeostasis. However, microglia activated in response to brain injury produce various inflammatory mediators, including nitric oxide (NO) and proinflammatory cytokines, leading to considerable neuronal damage. NO generated by inducible NO synthase (iNOS) rapidly reacts with superoxide to form a highly toxic product, peroxynitrite. Therefore, iNOS is considered to be a putative therapeutic target for cerebral ischemia. Here, we examined the effects of panobinostat (Pano), a histone deacetylase inhibitor, on lipopolysaccharide (LPS)-induced iNOS expression using rat immortalized microglia HAPI cells. Pano inhibited LPS-induced expression of iNOS mRNA and NO production in a dose-dependent manner; however, it had little effect on the LPS-induced activation of c-Jun N-terminal kinase (JNK) and p38 or nuclear translocation of nuclear factor-κB (NF-κB). The interferon-β (IFN-β)/signal transducer and activator of transcription (STAT) pathway is essential for LPS-induced iNOS expression in macrophages/microglia. We also examined the effects of Pano on LPS-induced IFN-β signaling. Pano markedly inhibited LPS-induced IFN-β expression and subsequent tyrosine phosphorylation of STAT1. However, the addition of IFN-β restored the decreased STAT1 phosphorylation but not the decreased iNOS expression. In addition, Pano inhibited the LPS-increased expression of octamer binding protein-2 and interferon regulatory factor 9 responsible for iNOS expression, but IFN-β addition also failed to restore the decreased expression of these factors. Thus, we conclude that the inhibitory effects of Pano are due not only to the inhibition of the IFN-β/STAT axis but also to the downregulation of other factors not involved in this axis.

Anti-inflammatory effects of the Thai herbal remedy Yataprasen and biflavonoids isolated from Putranjiva roxburghii in RAW264.7 macrophages

Ethnopharmacological relevanceYataprasen is a topical Thai herbal remedy for the treatment of musculoskeletal pain and is included in Kumpe Thart Phra Narai, the first Thai textbook of traditional medicine. The herbal preparation is made from a hydroethanolic extract of a mixture of 13 medicinal plants, of which Putranjiva roxburghii Wall. leaves are the major ingredient. Aim of the studyIn this study, we investigated the underlying mechanism of action for the anti-inflammatory effects of the Yataprasen remedy, its main ingredients, and the phytochemicals isolated from P. roxburghii leaves. Materials and methodsThe anti-inflammatory effects of the Yataprasen remedy, along with its main ingredients, including the leaves of Baliospermum solanifolium (Burm.) Suresh, Melia azedarach L., P. roxburghii, Senna siamea (Lam.) Irwin & Barneby, and Tamarindus indica L. were determined by measuring prostaglandin E2 (PGE2) secretion, nitric oxide (NO) production, and the synthesis of inflammatory biomarkers in lipopolysaccharide (LPS)-treated RAW264.7 macrophage cells. The active ingredients of the P. roxburghii leaves were separated by chromatography and spectroscopic measurements were used to identify their chemical structures. ResultsEthanol extracts of the Yataprasen remedy and some of its ingredients significantly suppressed LPS-induced PGE2 secretion and NO production in a dose-dependent manner. Treatment of RAW264.7 cells with ethanolic extracts of the Yataprasen remedy (50 μg/mL) significantly inhibited LPS-induced mRNA expression of TNF-α, COX-2, iNOS, and NF-κB. Among the plant ingredient extracts, P. roxburghii leaf extract exhibited the highest inhibitory effects on LPS-induced TNF-α and iNOS expression. Moreover, T. indica leaf extract showed the highest activity on the inhibition of LPS-induced COX-2 and NF-κB expression. Putraflavone, podocarpusflavone A, and amentoflavone were isolated biflavonoids from P. roxburghii leaf extract and showed the inhibitory effects on LPS-induced PGE2 secretion and NO synthesis in RAW264.7 cells. Of the isolated biflavonoids, amentoflavone exhibited the strongest anti-inflammatory activity by inhibiting the expression of TNF-α, COX-2, and iNOS. ConclusionThe results support reported the anti-inflammatory effects of the Yataprasen remedy, which are associated with the downregulation of proinflammatory mediators. P. roxburghii, along with its biflavonoids, are the impact components that contribute to the anti-inflammatory effects of the herbal remedy.

Sasanquasaponin from Camellia oleifera Abel Exerts an Anti-Inflammatory Effect in RAW 264.7 Cells via Inhibition of the NF-κB/MAPK Signaling Pathways.

Sasanquasaponin (SQS), a secondary metabolite that is derived from Camellia seeds, reportedly possesses notable biological properties. However, the anti-inflammatory effects of SQS and its underlying mechanisms remain poorly explored. Herein, we aimed to investigate the anti-inflammatory properties of SQS against lipopolysaccharide (LPS)-induced inflammatory responses in RAW264.7 cells, focusing on the nuclear factor-κB (NF-κB) and MAPK signaling pathways. SQS was isolated using a deep eutectic solvent and D101 macroporous adsorption resin and analyzed using high-performance liquid chromatography. The viability of LPS-stimulated RAW264.7 was assessed using the CCK-8 assay. The presence of reactive oxygen species (ROS) was evaluated using 2',7'-dichlorofluorescein-diacetate. The expression levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) were detected using reverse transcription-quantitative PCR and ELISA. Western blot was performed to analyze the protein expression of LPS-induced RAW264.7 cells. Herein, SQS exhibited anti-inflammatory activity: 30 μg/mL of SQS significantly reduced ROS generation, inhibited the LPS-induced expression of iNOS and COX-2, and attenuated the production of pro-inflammatory cytokines IL-1β, IL-6, and TNF-α. The anti-inflammatory activity was potentially mediated by inhibiting the phosphorylation of IκBα and p65 in the NF-κB signaling pathway and the phosphorylation of ERK and JNK in the MAPK signaling pathway. Accordingly, SQS could inhibit inflammation in LPS-induced RAW264.7 cells by suppressing the NF-κB and MAPK signaling pathways. This study demonstrated the potential application of SQS as an anti-inflammatory agent.

Stimulation of Angiotensin II Type 2 Receptor Modulates Pro-Inflammatory Response in Microglia and Macrophages: Therapeutic Implications for the Treatment of Stroke.

Sustained microglial activation contributes to the development of post-stroke cognitive impairment (PSCI). Compound 21 (C21), an angiotensin II type 2 receptor agonist, has shown some neurovascular protection after stroke. This study aimed to investigate the direct anti-inflammatory effects of C21 on macrophages, as well as brain innate immune cells. Murine microglial cell line (C8-B4) and RAW 264.7 macrophages were exposed to lipopolysaccharide (LPS) and co-treated with C21. Pro-inflammatory mediators were assessed via RT-qPCR and ELISA. Cellular reactive oxygen species (ROS) were evaluated via CellROXGreen staining, and nitrate production was assessed using Griess assay. C21 suppressed LPS-induced inflammation and ROS generation in both cells. In microglia, C21 blunted LPS-induced mRNA expression of IL-1β, IL-12b, COX-1, iNOS, and IL-6. A similar pattern was observed in macrophages, where C21 suppressed LPS-induced IL-1β, TNF-α, and CXCL1 expression. These anti-inflammatory effects in microglia and macrophages were associated with increased neuroprotective gene expression, including GDNF and BDNF, in a dose-dependent manner. Our findings suggest a protective effect of C21 against the inflammatory response, in both macrophages and microglia, via suppression of the release of pro-inflammatory cytokines/chemokines and the generation of ROS while stimulating the production of neurotrophic factors.

A new ginger extract characterization: Immunomodulatory, antioxidant effects and differential gene expression

Ginger (Zingiber officinale) is commonly consumed as spice or herbal medicine with anti-inflammatory, antioxidant, and anticancer properties. It is rich of many bioactive constituents, mainly gingerols and shogaols. Although the bioactive constituents have been identified, the molecular mechanisms of ginger action are still limited, and the related signalling pathways not completely defined. Here, we used a simple ethanol/freeze-drying method to obtain a new ginger extract (GE), which was chemically characterised by Folin-Ciocalteu, antioxidant ORAC and HPLC assays. At cellular level, anti-inflammatory/antioxidant properties of GE, in addition to the commercial [6]-gingerol, were evaluated using RAW264.7 murine macrophages. Cell viability tests verified the non-toxic doses of GE and [6]-gingerol, and the glutathione assay confirmed the antioxidant property of GE. By quantitative PCR, we analysed the differential expression of various genes in LPS-treated cells, after GE/[6]-gingerol pre-treatments. The genes belonged to different categories: immune signalling, pro-/anti-inflammatory cytokines, pro-/anti-antioxidant enzymes, hallmarks of macrophage polarization and endoplasmic reticulum stress response. Results showed that pre-treatment with two doses of GE reduced the LPS-induced expression of TLR4, MyD88, Rel-A, IL-1α, IL-6, TNF-α, IL-10, iNOS and TRIB3 genes to varying degrees, whereas increased Jun, Light/Tnfsf14, HO-1 and Arg-1 gene expression. No effect was found on MIF expression in LPS-induced cells after GE pre-treatments. These results also suggested that GE pre-treatment promotes the expression of specific markers of macrophage polarization in LPS-stimulated cells, with a trend to activate an anti-inflammatory M2 phenotype. Further analyses will broaden the understanding of the role of individual GE components in cellular inflammation/immunomodulation.

2-Aryl Propionic Acid Amide Modification of Naproxen and Ibuprofen Dimers for Anti-neuroinflammatory Activity in BV2 mouse Microglial Cells

Inflammation is a common link in the pathophysiology of many neurological illnesses, including Alzheimer’s disease. Activated glial cells contribute to neuroinflammation by producing pro-inflammatory mediators. Naproxen and ibuprofen are nonsteroidal anti-inflammatory drugs with 2-aryl(s) propionic acid as a common pharmacophore. Here we designed a small series of naproxen and ibuprofen amide dimers and tested their effects on the expression of inducible nitric oxide synthase (iNOS), a neuroinflammatory enzyme in lipopolysaccharide (LPS)-stimulated BV2 mouse microglial cells. Of note, treatment with CNU 019, 020, 021, 023, 024, and 027 at 10 M markedly inhibited the LPS-induced iNOS expression in BV2 cells. CNU 024 was tested further at different concentrations to regulate the LPS-induced iNOS expression in BV2 cells. Treatment with CNU 024 at 5, 10, or 20 M dose-dependently suppressed the LPS-induced iNOS protein and mRNA expression levels in BV2 cells, in which maximal inhibition was seen at 20 M. CNU 024 treatment at doses tested further led to a concentration-dependent inhibition of the LPS-induced phosphorylation (activation) of p38 mitogen-activated protein kinase (MAPK) without influencing its total protein expression in BV2 cells, but it did not affect the LPS-induced activation of c-jun N-terminal kinase-1/2 and extracellular signal-regulated kinases-1/2 in these cells. In summary, our results demonstrate that CNU 024 inhibits the LPS-induced iNOS expression in BV2 cells, partly mediated by the inhibition of p38 MAPK. This work shows that CNU 024 could be a valuable ligand for further development as a potential drug candidate for treating neuroinflammatory pathologies.

Novel tryptanthrin derivatives with benzenesulfonamide substituents: Design, synthesis, and anti-inflammatory evaluation

Herein, two series of tryptanthrin derivatives with benzenesulfonamide substituents were designed and synthesized to discover novel anti-inflammatory agents. The anti-inflammatory activities of all derivatives were screened by evaluating their inhibitory effects on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW264.7 cells. Among them, compound 8j exhibited the best NO inhibitory activity (IC50 = 1.25 ± 0.21 μM), with no obvious toxicity. Further evaluation showed that 8j could also significantly reduce the levels of pro-inflammatory cytokines interleukin-1β (IL-1β, IC50 = 8.48 ± 0.23 μM) and tumor necrosis factor-α (TNF-α, IC50 = 11.53 ± 0.35 μM) and downregulate the LPS-induced expression of iNOS and COX-2. Reverse docking of 8j suggested p38α as the molecular target, which is a well-known crucial player in the p38 MAPK signaling pathway that controls the transcription of pro-inflammatory mediators. Cellular thermal shift assay showed that 8j efficiently stabilized p38α in LPS-treated RAW264.7 cells. Western blot showed that inflammatory response was inhibited by 8j through inhibiting the phosphorylation of p38α and MK2 in the p38 MAPK signaling pathway. Finally, In vivo studies showed that 8j could significantly ameliorate the degree of foot swelling and knee joint pathology in adjuvant-induced arthritis (AIA) rats and reduce levels of TNF-α and IL-1β in serum, achieving the effect of protecting synovial tissue and ameliorating arthritis. These findings suggested that 8j may be a promising compound for further development of anti-inflammatory agents.

Hydrolyzed Collagen Induces an Anti-Inflammatory Response That Induces Proliferation of Skin Fibroblast and Keratinocytes.

Collagen-based products are found in different pharmaceuticals, medicine, food, and cosmetics products for a wide variety of applications. However, its use to prevent or improve the health of skin is growing dizzyingly. Therefore, this study investigated whether collagen peptides could induce fibroblast and keratinocyte proliferation and activation beyond reducing an inflammatory response induced by lipopolysaccharide (LPS). Human skin fibroblasts (CCD-1072Sk) and human keratinocytes (hKT-nh-skp-KT0026) were seeded at a concentration of 5 × 104 cells/mL. LPS (10 ng/mL) and three doses of collagen peptides (2.5 mg/mL, 5 mg/mL, 10 mg/mL) were used. The readout parameters were cell proliferation; expression of inducible nitric oxide synthase (iNOS); expression of pro-collagen-1α by fibroblasts; and secretion of interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor α (TNF-α), transforming growth factor β (TGF-β), and vascular endothelial growth factor (VEGF) by both cell types. The results demonstrated that all doses of collagen supplementation induced increased proliferation of both human fibroblasts (p < 0.01) and human keratinocytes (p < 0.001), while only the dose of 10 mg/mL induced an increased expression of pro-collagen-1α by fibroblasts. Similarly, only the dose of 10 mg/mL reduced LPS-induced iNOS expression in fibroblasts (p < 0.05) and keratinocytes (p < 0.01). In addition, collagen supplementation reduced the LPS-induced IL-1β (p < 0.05), IL-6 (p < 0.001), IL-8 (p < 0.01), and TNF-α (p < 0.05), and increased the TGF-β and VEGF expression in fibroblasts. Furthermore, collagen supplementation reduced the LPS-induced IL-1β (p < 0.01), IL-6 (p < 0.01), IL-8 (p < 0.01), and TNF-α (p < 0.001), and increased the TGF-β (p < 0.05) and VEGF (p < 0.05) expression in keratinocytes. In conclusion, collagen peptides were found to induce fibroblast and keratinocyte proliferation and pro-collagen-1α expression, involving increased expression of TGF-β and VEGF, as well as the suppression of an inflammatory response induced by LPS.

Protective Effect of Nopal Cactus (Opuntia ficus-indica) Seed Oil against Short-Term Lipopolysaccharides-Induced Inflammation and Peroxisomal Functions Dysregulation in Mouse Brain and Liver.

Exposure to endotoxins (lipopolysaccharides, LPS) may lead to a potent inflammatory cytokine response and a severe impairment of metabolism, causing tissue injury. The protective effect provided by cactus seed oil (CSO), from Opuntia ficus-indica, was evaluated against LPS-induced inflammation, dysregulation of peroxisomal antioxidant, and β-oxidation activities in the brain and the liver. In both tissues, a short-term LPS exposure increased the proinflammatory interleukine-1β (Il-1β), inducible Nitroxide synthase (iNos), and Interleukine-6 (Il-6). In the brain, CSO action reduced only LPS-induced iNos expression, while in the liver, CSO attenuated mainly the hepatic Il-1β and Il-6. Regarding the peroxisomal antioxidative functions, CSO treatment (as Olive oil (OO) or Colza oil (CO) treatment) induced the hepatic peroxisomal Cat gene. Paradoxically, we showed that CSO, as well as OO or CO, treatment can timely induce catalase activity or prevent its induction by LPS, respectively, in both brain and liver tissues. On the other hand, CSO (as CO) pretreatment prevented the LPS-associated Acox1 gene and activity decreases in the liver. Collectively, CSO showed efficient neuroprotective and hepato-protective effects against LPS, by maintaining the brain peroxisomal antioxidant enzyme activities of catalase and glutathione peroxidase, and by restoring hepatic peroxisomal antioxidant and β-oxidative capacities.

Glucogallin Attenuates the LPS-Induced Signaling in Macrophages and Protects Mice against Sepsis.

The anti-oxidant and anti-inflammatory effect of beta-glucogallin (BGG), a plant-derived natural product, was evaluated in both in vitro and in vivo studies. For the in vitro study, the ability of BGG pre-treatment to quench LPS-induced effects compared to LPS alone in macrophages was investigated. It was found that BGG pre-treatment showed a significant decrease in ROS, NO, superoxide, and pro-inflammatory cytokines (TNF-alpha, IL-4, IL-17, IL-1β, and IL-6) and increased reduced glutathione coupled with the restoration of mitochondrial membrane potential. Gene profiling and further validation by qPCR showed that BGG pre-treatment downregulated the LPS-induced expression of c-Fos, Fas, MMP-9, iNOS, COX-2, MyD88, TRIF, TRAF6, TRAM, c-JUN, and NF-κB. We observed that BGG pre-treatment reduced nuclear translocation of LPS-activated NF-κB and thus reduced the subsequent expressions of NLRP3 and IL-1β, indicating the ability of BGG to inhibit inflammasome formation. Molecular docking studies showed that BGG could bind at the active site of TLR4. Finally, in the LPS-driven sepsis mouse model, we showed that pre-treatment with BGG sustained toxic shock, as evident from their 100% survival. Our study clearly showed the therapeutic potential of BGG in toxic shock syndrome.

Sophorolipid Suppresses LPS-Induced Inflammation in RAW264.7 Cells through the NF-κB Signaling Pathway.

Objectives: Biosurfactants with anti-inflammatory activity may alleviate skin irritation caused by synthetic surfactants in cleaning products. Sophorolipid (SL) is a promising alternative to synthetic surfactants. However, there are few reports on the anti-inflammatory activity of SL and the underlying mechanism. The purpose of this work is to verify that lipopolysaccharide (LPS)-induced inflammation could be inhibited through targeting the pathway of nuclear factor-κB (NF-κB) in RAW264.7 cells. Methods: The influence of SL on cytokine release was investigated by LPS-induced RAW264.7 cells using ELISA. The quantification of the protein expression of corresponding molecular markers was realized by Western blot analysis. Flow cytometry was employed to determine the levels of Ca2+ and reactive oxygen species (ROS). The relative expression of inducible nitric oxide synthase (INOS) and cyclooxygenase-2 (COX-2) was determined by RT-PCR. An immunofluorescence assay and confocal microscope were used to observe the NF-κB/p65 translocation from the cytoplasm into the nucleus. The likely targets of SL were predicted by molecular docking analysis. Results: SL showed anti-inflammatory activity and reduced the release of inflammatory cytokines including interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and nitric oxide (NO). The experimental results show that SL suppressed the Ca2+ and ROS levels influx in the LPS-induced RAW264.7 cells and alleviated the LPS-induced expression of iNOS and COX-2, the LPS-induced translocation of NF-κB (p65) from the cytoplasm into the nucleus, and the expression of phosphorylated proteins such as p65 and IκBα. Furthermore, molecular docking analysis showed that SL may inhibit inflammatory signaling by competing with LPS to bind TLR4/MD-2 through hydrophobic interactions and by inhibiting IKKβ activation through the hydrogen bonding and hydrophobic interactions. Conclusion: This study demonstrated that SL exerted anti-inflammatory activity via the pathway of NF-κB in RAW264.7 cells.

Mussaendoside O, a N-triterpene cycloartane saponin, attenuates RANKL-induced osteoclastogenesis and inhibits lipopolysaccharide-induced bone loss

BackgroundElevated activity of osteoclasts (OCs) is linked to osteolytic bone diseases, such as osteoporosis and rheumatoid arthritis. Developing natural anti-osteoclastogenic compounds with greater efficacy and fewer adverse effects is crucial for preventing or treating osteolytic bone diseases. N-triterpene cycloartane saponins (NTCSs) are rarely found in nature, and their inhibitory effects on OC differentiation in vitro and in vivo have not yet been explored. PurposeThis study was aimed to investigate the effect of mussaendoside O, an NTCS isolated from Mussaenda pubescens, on RANKL-induced OC differentiation and its underlying mechanism in vitro, and lipopolysaccharide (LPS)-induced bone resorption in a mouse model. MethodsThe content of mussaendoside O in methanol extract of M. pubescens was determined by HPLC. The inhibitory effects of mussaendoside O on RANKL-induced OC formation were assessed using TRAP staining, western blotting, immunofluorescence staining, and real-time qPCR. Meanwhile, the effects of mussaendoside O on LPS-induced inflammatory responses were assessed using a Griess reagent and qPCR. The effects of mussaendoside O on LPS-induced bone resorption in a mouse model were evaluated using micro-CT and immunohistochemical staining. ResultsMussaendoside O inhibited RANKL-induced TRAP-positive multinucleated OC formation in a concentration-dependent manner without affecting cell viability. However, mussaendoside O did not inhibit LPS-induced mRNA expression of COX-2, iNOS, and TNF-α. Mice orally administrated with mussaendoside O exhibited significant protection from LPS-induced bone resorption and OC formation. At the molecular level, mussaendoside O suppressed RANKL-activated phosphorylation of p38 MAPK and JNK, as well as c-Fos expression. In addition, mussaendoside O suppressed RANKL-induced NFATc1 activation and the expression of its target genes, including OSCAR, DC-STAMP, CtsK, and TRAP. ConclusionMussaendoside O attenuates OC differentiation in vitro and LPS-induced bone resorption in a mouse model by inhibiting the RANKL-activated c-Fos/NFATc1 signaling pathways. Therefore, mussaendoside O may be a valuable lead compound for preventing or treating of osteolytic bone diseases.

Anti-Inflammatory Activity of Glabralactone, a Coumarin Compound from Angelica sinensis, via Suppression of TRIF-Dependent IRF-3 Signaling and NF-κB Pathways.

The dried root of Angelica sinensis (A. sinensis) has been widely used in Chinese traditional medicine for various diseases such as inflammation, osteoarthritis, infections, mild anemia, fatigue, and high blood pressure. Searching for the secondary metabolites of A. sinensis has been mainly conducted. However, the bioactivity of coumarins in the plant remains unexplored. Therefore, this study was designed to evaluate the anti-inflammatory activity of glabralactone, a coumarin compound from A. sinensis, using in vitro and in vivo models, and to elucidate the underlying molecular mechanisms of action. Glabralactone effectively inhibited nitric oxide production in lipopolysaccharide- (LPS-) stimulated RAW264.7 macrophage cells. The downregulation of LPS-induced mRNA and protein expression of iNOS, TNF-α, IL-1β, and miR-155 was found by glabralactone. The activation of NF-κB and TRIF-dependent IRF-3 pathway was also effectively suppressed by glabralactone in LPS-stimulated macrophages. Glabralactone (5 and 10 mg/kg) exhibited an in vivo anti-inflammatory activity with the reduction of paw edema volume in carrageenan-induced rat model, and the expressions of iNOS and IL-1β proteins were suppressed by glabralactone in the paw soft tissues of the animal model. Taken together, glabralactone exhibited an anti-inflammatory activity in in vitro and in vivo models. These findings reveal that glabralactone might be one of the potential components for the anti-inflammatory activity of A. sinensis and may be prioritized in the development of a chemotherapeutic agent for the treatment of inflammatory diseases.

Molecular docking prediction and in vitro studies elucidate anti-inflammatory effect of Garcinia extract against inducible nitric oxide synthase and cyclooxygenase-2 targets

BackgroundGarcinia is a tropical plant that has been traditionally used in medicinal folklore for its potential antioxidant, antibacterial, anti-hyperlipidemic, anti-diabetic, hepatoprotective, etc. In this study, methanolic extract of Garcinia herbal supplement (GME) and its important phytoconstituents (Garcinol and hydroxycitric acid) were evaluated for their inhibitory action against important inflammatory markers iNOS and COX-2 in lipopolysaccharide-induced RAW 264.7 cells. iNOS and COX-2 play a major role in the process of inflammation, and inhibition of these molecules will help to alleviate the inflammatory process. The cells were pre-treated with two doses of GME (115 µg/ml and 230 µg/ml); Ggarcinol (6 µM and 12 µM); hydroxycitric acid (17.5 µg/ml and 35 µg/ml) followed by stimulation with 1 µg/ml of LPS for 24 h.ResultsThe results of the study demonstrated that Garcinia and its active components Garcinol and HCA play an important role in suppressing LPS-induced relative mRNA expression of iNOS, COX-2, and subsequent reduction in the levels of total nitric oxide and prostaglandinE2. Molecular docking analysis of Ggarcinol and HCA with iNOS and COX-2 proteins showed potent interactions with negative binding energies.ConclusionsThis study suggests that Garcinia possess anti-inflammatory activity thus providing a possibility for drug designing as iNOS and COX-2 inhibitor.Graphical

Ameliorative effect of the ethnomedicinal plant Blepharis maderaspatensis (L.) B.Heyne ex Roth on lipopolysaccharide-induced acute liver inflammation and oxidative stress in Wistar rat model

BackgroundBlepharis maderaspatensis is an ethnomedicinal plant used by the Mavilan and Koraga tribes of Kerala state, India for the treatment of liver diseases. Thus, the present study aims to evaluate the liver protective activity of defatted ethanolic extract of B. maderaspatensis on lipopolysaccharide-induced acute liver inflammation and oxidative stress in Wistar rat model. MethodsPreliminary phytochemical evaluation and high-performance thin-layer chromatography fingerprint validation were performed. The total phenolic and flavonoid contents were measured using the Folin-Ciocalteu method and the aluminium chloride method, respectively. The acute oral toxicity study was conducted in Swiss albino mice in accordance with OECD 423 guideline. Effect of defatted ethanolic extract of the whole plant of B. maderaspatensis (BmE) on liver inflammation was evaluated in LPS-induced Wistar rat model. The rats were treated with BmE (100, 250 and 500 mg/kg body weight) once daily for 7 days prior to the LPS (single dose i.p., 10 mg/kg b.w.) challenge. Liver tissue biochemicals (ALT, AST and ALP), and antioxidant status (SOD, CAT, GSH, MDA, NO and MPO) in euthanised experimental rats were carried out using commercial kits/standard procedures. Haematology (RBC, WBC, Hb and PLT; 4 and 24 h), and histopathology analysis were also performed. Serum IL-1β, IL-6, TNF-α and PGE2 production were determined by ELISA. The expressions of COX-2, iNOS, IL-1β, IL-6, TNF-α and NF-κB were analysed by qRT-PCR. Phosphorylation of IκB-α was measured by Western blotting. LC-MS analysis of BmE was also performed. ResultsThe LD50 value of BmE was found to be >5000 mg/kg b.w. BmE500 showed significant protection from LPS-induced liver injury as evidenced by reduced serum enzyme levels (AST, ALT and ALP; p≤ 0.001) and markedly improved the liver antioxidant status (MDA, GSH, SOD and CAT; p≤ 0.001), when compared to the LPS alone treated group. Haematology (24 h, RBC, WBC, Hb and PLT; p≤ 0.001) and histopathology also supported the above results. BmE500 pre-treatment significantly suppressed the LPS-induced expression of iNOS (p≤ 0.001) and COX-2 (p≤ 0.001), and the subsequent release of NO (p≤ 0.001) and PGE2 (p≤ 0.001). Moreover, BmE500 inhibited the gene expression of pro-inflammatory cytokines, including IL-1β (p≤ 0.001), IL-6 (p≤ 0.001), and TNF-α (p≤ 0.01), which is supported by ELISA results. In addition, BmE500 markedly attenuated the activation of transcription factor NF-κB (p≤ 0.001) as well as phosphorylation of IκBα, as evidenced from the qRT-PCR and Western blot analysis, respectively. The silymarin (100 mg/kg b.w.) drug standard also showed significant improvement in all parameters analysed. ConclusionResults of the present investigation suggest that BmE has a significant protective effect on LPS-induced acute liver inflammation via attenuating inflammatory reactions, evidenced by the inhibition of NF-κB signalling cascade, and also through its antioxidant effects. Thus, the pharmacological data generated provide experimental evidence that clearly justifies the use of B. maderaspatensis as a liver protective agent in tribal medicine.

Erinacine A Prevents Lipopolysaccharide-Mediated Glial Cell Activation to Protect Dopaminergic Neurons against Inflammatory Factor-Induced Cell Death In Vitro and In Vivo.

Hericium erinaceus (HE) is a common edible mushroom consumed in several Asian countries and considered to be a medicinal mushroom with neuroprotective effects. Erinacine A (EA) is a bioactive compound in Hericium erinaceus mycelium (HEM) that has been shown to have a neuroprotective effect against neurodegenerative diseases, e.g., Parkinson’s disease (PD). Although the etiology of PD is still unclear, neuroinflammation may play an important role in causing dopaminergic neuron loss, which is a pathological hallmark of PD. However, glial cell activation has a close relationship with neuroinflammation. Thus, this study aimed to investigate the anti-neuroinflammatory and neuroprotective effects of EA on lipopolysaccharide (LPS)-induced glial cell activation and neural damage in vitro and in vivo. For the in vitro experiments, glial cells, BV-2 microglial cells and CTX TNA2 astrocytes were pretreated with EA and then stimulated with LPS and/or IFN-γ. The expression of proinflammatory factors in the cells and culture medium was analyzed. In addition, differentiated neuro-2a (N2a) cells were pretreated with EA or HEM and then stimulated with LPS-treated BV-2 conditioned medium (CM). The cell viability and the amount of tyrosine hydroxylase (TH) and mitogen-activated protein kinases (MAPKs) were analyzed. In vivo, rats were given EA or HEM by oral gavage prior to injection of LPS into the substantia nigra (SN). Motor coordination of the rats and the expression of proinflammatory mediators in the midbrain were analyzed. EA pretreatment prevented LPS-induced iNOS expression and NO production in BV-2 cells and TNF-α expression in CTX TNA2 cells. In addition, both EA and HEM pretreatment significantly increased cell viability and TH expression and suppressed the phosphorylation of JNK and NF- κB in differentiated N2a cells treated with CM. In vivo, both EA and HEM significantly improved motor dysfunction in the rotarod test and the amphetamine-induced rotation test and reduced the expression of TNF-α, IL-1β and iNOS in the midbrain of rats intranigrally injected with LPS. The results demonstrate that EA ameliorates LPS-induced neuroinflammation and has neuroprotective properties.

The sesquiterpene lactone estafiatin exerts anti-inflammatory effects on macrophages and protects mice from sepsis induced by LPS and cecal ligation puncture

BackgroundPreviously, we found that the water extract of Artermisia scoparia Waldst. & Kit suppressed the cytokine production of lipopolysaccharide (LPS)-stimulated macrophages and alleviated carrageenan-induced acute inflammation in mice. Artemisia contains various sesquiterpene lactones and most of them exert immunomodulatory activity. PurposeIn the present study, we investigated the immunomodulatory effect of estafiatin (EST), a sesquiterpene lactone derived from A. scoparia, on LPS-induced inflammation in macrophages and mouse sepsis model. Study design and methodsMurine bone marrow-derived macrophages (BMDMs) and THP-1 cells, a human monocytic leukemia cell line, were pretreated with different doses of EST for 2 h, followed by LPS treatment. The gene and protein expression of pro-inflammatory cytokines interleukin (IL)-6, tumor necrosis factor (TNF)-α, and inducible nitric oxide synthase (iNOS) were measured by quantitative real-time polymerase chain reaction (qPCR) and Western blot analysis. The activation of nuclear factor kappa B (NF-κB) and mitogen-activated protein kinases (MAPKs) was also evaluated at the level of phosphorylation. The effect of EST on inflammatory cytokine production, lung histopathology, and survival rate was assessed in an LPS-induced mice model of septic shock. The effect of EST on the production of cytokines in LPS-stimulated peritoneal macrophages was evaluated by in vitro and ex vivo experiments and protective effect of EST on cecal ligation and puncture (CLP) mice was also assessed. ResultsThe LPS-induced expression of IL-6, TNF-α, and iNOS was suppressed at the mRNA and protein levels in BMDMs and THP-1 cells, respectively, by pretreatment with EST. The half-maximal inhibitory concentration (IC50) of EST on IL-6 and TNF-α production were determined as 3.2 μM and 3.1 μM in BMDMs, 3 μM and 3.4 μM in THP1 cells, respectively. In addition, pretreatment with EST significantly reduced the LPS-induced phosphorylation p65, p38, JNK, and ERK in both cell types. In the LPS-induced mice model of septic shock, serum levels of IL-6, TNF-α, IL-1β, CXCL1, and CXCL2 were lower in EST-treated mice than in the control animals. Histopathology analysis revealed that EST treatment ameliorated LPS-induced lung damage. Moreover, while 1 of 7 control mice given lethal dose of LPS survived, 3 of 7 EST-treated (1.25 mg/kg) mice and 5 of 7 EST-treated (2.5 mg/kg) mice were survived. Pretreatment of EST dose-dependently suppressed the LPS-induced production of IL-6, TNF-α and CXCL1 in peritoneal macrophages. In CLP-induced mice sepsis model, while all 6 control mice was dead at 48 h, 1 of 6 EST-treated (1.25 mg/kg) mice and 3 of 6 EST-treated (2.5 mg/kg) mice survived for 96 h. ConclusionThese results demonstrated that EST exerts anti-inflammatory effects on LPS-stimulated macrophages and protects mice from sepsis. Our study suggests that EST could be developed as a new therapeutic agent for sepsis and various inflammatory diseases.

New lathyrane diterpenoid hybrids have anti-inflammatory activity through the NF-κB signaling pathway and autophagy

In our ongoing work on the identification of potent anti-inflammatory agents, we designed and synthesized three series of lathyrane diterpenoid hybrids in which the lathyrane diterpenoid skeleton was hybridized with other anti-inflammatory pharmacophores. Unexpectedly, lathyrane diterpenoid/3-hydroxyflavone hybrids showed more potent anti-inflammatory activity in RAW264.7 cells than did the corresponding parent compounds. Compound 8d1 exhibited potent anti-inflammatory activity with low cytotoxicity (IC50 = 1.55 ± 0.68 μM), and downregulated LPS-induced expression of iNOS and COX-2, as well as IκBα phosphorylation. This compound also inhibited the expression and nuclear translocation of NF-κB, and stimulated autophagy induction. Thus, 8d1’s anti-inflammatory mechanism is associated with inhibition of the NF-κB signaling pathway and increasing autophagy. This compound may serve as a promising anti-inflammatory agent.

Extracts with anti-inflammatory activities from Acanthopanax trifoliatus (L.) Merr. by inhibiting LPS-induced expression of iNOS and COX-2

Acanthopanax trifoliatus (L.) Merr. have been used as folk medicine to treat various diseases traditionally and the young leaves and shoots of A. trifoliatus are popularly consumed as vegetables and herbal tea in southern China. In the study, we firstly tested the cytotoxicity and NO production of 18 fractions that extracted from the leaves, stems and roots of A. trifoliatus to select the bioactive fraction. The increasing evidence suggested that the dichloromethane extract prepared from stems of A. trifoliatus (ATSDC) have anti-inflammatory activity. Therefore, the study followed to investigate the effects of ATSDC on the inflammatory response and the molecular mechanisms underpinning this effect in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. The manuscript showed that ATSDC effectively inhibited NO production in LPS-stimulated cells and significantly reduced the production of pro-inflammatory cytokines IL-6, at a dose of 40 µg/mL, whereas TNF-α production tended to decrease under ATSDC treatment. We also confirmed a dose-dependent and significant inhibition of iNOS and COX-2 protein expression. In conclusion, ATSDC exerted strong inhibitory effect on the expression of iNOS and COX-2 protein in LPS-induced RAW 264.7 macrophages and could be potentially used in treatment of inflammatory-related diseases in the future.

Inhibition of LPS-induced expression of iNOS and COX-2 on extracts of Acanthopanax leucorrhizus (Oliv.) Harms stems

Acanthopanax leucorrhizus is an endemic medicinal plant growing abundantly in the northwest region of China. The roots and stem barks have been widely used to treat rheumatism, numbness, contracture, quadriplegia, hemiplegia, traumatic injury, edema, and itchy skin, although the anti-inflammatory effects of the extracts of A. leucorrhizus have not been assessed until now. To investigate the anti-inflammatory effects on macrophages of various extracts from A. leucorrhizus stems, alterations in the inducible nitric oxide synthase (iNOS)-mediated cyclooxygenase-2 (COX-2) expression and inflammatory cytokine production were measured in lipopolysaccharide (LPS)-activated RAW264.7 cells. Briefly, the dichloromethane extract prepared from stems of A. leucorrhizus (ALSDC) effectively inhibited NO production in LPS-stimulated cells and significantly reduced the production of pro-inflammatory cytokines IL-6 and TNF-α at a dose of 40 µg/mL. We also confirmed a dose-dependent and significant inhibition of iNOS and COX-2 protein expression. In conclusion, ALSDC exerted strong inhibitory effect on the expression of iNOS and COX-2 protein in LPS-induced RAW 264.7 macrophages and these results provide strong evidence to suggest that ALSDC may be considered as an important candidate for the treatment of inflammatory-related diseases in the future.