LPS-induced Nitric Oxide Production Research Articles

A new bergamotane sesquiterpenoid from the rhizomes of Amomum villosum var. xanthioides

A new bergamotane-type sesquiterpene, named axanthiol A (1), and six known compounds (2–7) were isolated from the rhizomes of Amomum villosum var. xanthioides. Their structures were established on the basis of extensive spectroscopic analysis and the absolute configuration of 1 was confirmed by the Mosher ester method. Moreover, all the isolates were evaluated for their effects on LPS-induced nitric oxide (NO) production, and compound 5 showed efficacious inhibitory activity with IC50 value of 34.81 μM.

Evaluation of Anti-HIV-1 Integrase and Anti-Inflammatory Activities of Compounds from Betula alnoides Buch-Ham.

Betula alnoides is a medicinal plant in Thai traditional longevity preparations. The crude extracts of this plant possess various biological activities. However, the isolated compounds from this plant have no reports of anti-HIV-1 integrase (IN) activity. Therefore, the present study aims to investigate the anti-HIV-1 integrase and anti-inflammatory effects of isolated compounds from this plant and predict the interaction of compounds with integrase active sites. From the bioassay-guided fractionation of the ethanol extract of B. alnoides stems using chromatographic techniques, five pentacyclic triterpenoid compounds were obtained. They are betulinic acid (1), betulin (2), lupeol (3), oleanolic acid (4), and ursolic acid (5). Compound 2 exhibited the most potent inhibitory activity against HIV-1 IN, with an IC50 value of 17.7 μM. Potential interactions of compounds with IN active sites were investigated using computational docking. The results indicated that active compounds interacted with Asp64, a residue participating in 3′-processing, and Thr66, His67, and Lys159, residues participating in strand-transfer reactions of the integration process. Regarding anti-inflammatory activity, all compounds exerted significant inhibitory effects on LPS-induced nitric oxide production (IC50 < 68.7 μM). Thus, this research provides additional scientific support for the use of B. alnoides in traditional medicine for the treatment of HIV patients.

Sesquiterpenoids with diverse carbon skeletons from the roots of Cichorium glandulosum and their anti-inflammatory activities

A total of thirteen sesquiterpenoids with diverse skeletons including four new sesquiterpenoids, glandulosines A − D (1–4), a new natural product, glandulosine E (5), and eight known sesquiterpene lactones (6–13) were isolated from the roots of Cichorium glandulosum Boiss. et Huet (Asteraceae). Their structures were determined by extensive spectroscopic experiments including NMR, electronic circular dichroism (ECD), calculated ECD, Rh2(OCOCF3)4-induced ECD, and single-crystal X-ray diffraction analysis, as well as chemical methods. This is the first report of the crystal structure of 11β,13-dihydrolactucin (11). Thirteen isolated sesquiterpenoids (1−13) were evaluated for their anti-inflammatory activities in vitro, and three guaiane sesquiterpene lactones, glandulosine E (5), scorzoside (9), and lactucin (10) showed moderate inhibitory activity against LPS-induced nitric oxide (NO) production in RAW 264.7 macrophages.

Alcohol effects on immune responses of classical pro-inflammatory macrophages

Abstract Alcohol consumption modulates immune responses. However, the mechanisms of ethanol’s action on the immune system are not fully understood. Previous studies demonstrated that ethanol enhances the activity of adenylyl cyclase (AC) in an isoform-specific manner, that type 7 AC (AC7) is most enhanced by ethanol, and that AC7 is highly expressed in immune cells. Therefore, we hypothesized that AC7 is a central player in regulating alcohol’s effects on immune responses. To examine this hypothesis, we generated AC7 knockout (KO) cell lines from a mouse microglia cell line, BV-2, and isolated primary bone marrow-derived macrophages (BMDM) from myeloid lineage-specific AC7 KO mice. Cells were activated by lipopolysaccharides (LPS) and interferon gamma (IFN-γ) to classical pro-inflammatory macrophages. The effects of ethanol on nitric oxide (NO) production of macrophages were examined via Griess reagent. LPS and IFN-γ synergistically increased nitric oxide (NO) production in wild type (WT) BV-2 cells in a dose-dependent manner. Ethanol suppressed LPS and IFN-γ co-activated NO production. AC7 KO BV-2 cells did not respond to LPS or IFN-γ activation. LPS increased NO production of both WT and AC7 KO BMDM. NO production of KO BMDM was significantly lower than that of WT BMDM. IFN-γ increased LPS-induced NO production of both WT and AC7 KO BMDM. Ethanol suppressed LPS-induced NO production in a dose-dependent manner in WT BMDM, while this effect was reduced in AC7 KO BMDM. The results suggest that AC7 is a key factor in the regulation of NO production and that the effect of ethanol on NO production depends on AC7. In the future, we will investigate the iNOS expression signaling cascade of classical pro-inflammatory macrophages in the presence of ethanol.

Four new sesquiterpenoids with anti-inflammatory activity from the stems of Jasminum officinale

Four new sesquiterpenoids，including three nor-cinalbicane type sesquiterpenoids, named Jasminol A, G, H (1–3) and one eremophilene-type sesquiterpenoid, named Jasminol B (4) together with nine known compounds (5–13) were isolated from the stems of Jasminum officinale L. The structures of new compound were elucidated on the base of IR, HR-ESI-MS, 1D NMR, 2D NMR and DEPT analysis, and the absolute configurations were determined by single-crystal X-ray diffraction analysis. In addition, the anti-inflammatory activity of isolated compounds was evaluated using lipopolysaccharide (LPS)-induced murine macrophage RAW264.7, and compounds 1–4 exhibited a moderate inhibition of LPS-induced nitric oxide (NO) production in RAW264.7 cells with IC50 values of 20.56 ± 1.31, 30.12 ± 0.89, 30.35 ± 2.72 and 31.60 ± 1.69 μM, respectively, and CC50 values >200 uM.

Aromatic constituents from Ganoderma lucidum and their neuroprotective and anti-inflammatory activities

Five new aromatic compounds, designed as lucidumins A-D (1–4) and lucidimine E (9), along with seven known aromatic compounds (5–8, 10–12) were isolated from Ganoderma lucidum. Their structures were determined by spectroscopic method. Bioactive evaluation showed that compounds 2–4 and 6–10 displayed remarkable neuroprotective activities against corticosterone-induced PC12 cell damage, with the cell viability ranging from 69.99% to 126.00%; and compounds 1–4, 9 and 10 exhibited significant anti-inflammatory activities against LPS-induced nitric oxide (NO) production in RAW264.7 macrophages, with IC50 values ranging from 4.68 to 15.49 μM. In particular, compound 10 showed remarkable neuroprotection with EC50 value of 2.49 ± 0.12 μM, and potent anti-inflammation with IC50 value of 4.68 ± 0.09 μM.

Modulation of LPS-induced nitric oxide production in intestinal cells by hydroxytyrosol and tyrosol metabolites: Insight into the mechanism of action

At intestinal level, after acute or chronic exposure to iNOS-derived NO, a toxic mechanism of action leads to inflammation and degenerative diseases. The aim of this study was to investigate the effect of glucuronide and sulfate metabolites of the extra virgin olive oil phenols tyrosol (Tyr) and hydroxytyrosol (HT), in comparison with their parent compounds, on the release of NO following exposure to a pro-inflammatory stimulus, the bacterial lipopolysaccharide (LPS). Human colon adenocarcinoma cells (Caco-2), differentiated as normal enterocytes, were treated with pathological concentrations of LPS, in order to stimulate iNOS pathway, which involves NF-ĸB activation through IĸBα phosphorylation and subsequent degradation induced by Akt or MAPKs. All the tested metabolites inhibited NO release induced by LPS, acting as inhibitors of iNOS expression, with an efficacy comparable to that of the parent compounds. HT and Tyr metabolites were effective in the inhibition of IĸBα degradation. No one of the compounds was able to inhibit Akt activation, whereas they modulated p38 and ERK1/2 MAPK. Obtained data show that HT and Tyr metabolites are able to prevent a pathological NO overproduction at intestinal level, where they concentrate, thus significantly contributing to the protective activity exerted by their parent compounds against inflammation.

Anti-inflammatory drug-eluting implant model system to prevent wear particle-induced periprosthetic osteolysis.

BackgroundAseptic loosening, as a consequence of an extended inflammatory reaction induced by wear particles, has been classified as one of the most common complications of total joint replacement (TJR). Despite its high incidence, no therapeutical approach has yet been found to prevent aseptic loosening, leaving revision as only effective treatment. The local delivery of anti-inflammatory drugs to modulate wear-induced inflammation has been regarded as a potential therapeutical approach to prevent aseptic-loosening.MethodsIn this context, we developed and characterized anti-inflammatory drug-eluting TiO2 surfaces, using nanoparticles as a model for larger surfaces. The eluting surfaces were obtained by conjugating dexamethasone to carboxyl-functionalized TiO2 particles, obtained by using either silane agents with amino or mercapto moieties.ResultsZeta potential measurements, thermogravimetric analysis (TGA) and drug release results suggest that dexamethasone was successfully loaded onto the TiO2 particles. Release was pH dependent and greater amounts of drug were observed from amino route functionalized surfaces. The model-system was then tested for its cytotoxic and anti-inflammatory properties in LPS-stimulated macrophages. Dexamethasone released from amino route functionalized surfaces TiO2 particles was able to decrease LPS-induced nitric oxide (NO) and TNF-a production similarly to pure DEX at the same concentration; DEX released from mercapto route functionalized surfaces was at a too low concentration to be effective.ConclusionDexamethasone released from amino functionalized titanium can offer the possibility of preventing asepting loosening of joint replacement devices.

Anti-Inflammatory Effects of Aurantiochytrium limacinum 4W-1b Ethanol Extract on Murine Macrophage RAW264 Cells.

Aurantiochytrium limacinum 4W-1b (AL4W-1b) is a newly discovered microalgal strain with unique features. In the present study, we investigated the effects of ethanol extracts of AL4W-1b on lipopolysaccharide- (LPS-) induced inflammatory responses in RAW264 murine macrophage cells. Pretreatment of RAW264 cells with the AL4W-1b extract significantly reduced the production of LPS-induced nitric oxide (NO) and the expression of proinflammatory cytokine genes, including tumor necrosis factor α, interleukin- (IL-) 1β, and IL-6. Treatment with the AL4W-1b extract also decreased the production of IL-1β and IL-6. These results suggest that AL4W-1b might have anti-inflammatory effects in RAW264 cells. The NF-κB inhibitor, BAY 11-7082, synergistically prevented LPS-induced NO production after pretreatment with the AL4W-1b extract. Thus, the AL4W-1b extract may affect not only the NF-κB pathway but also other inflammatory pathways. To the best of our knowledge, this is the first study to report the anti-inflammatory effects of AL4W-1b extract and its mechanism of action in LPS-stimulated murine macrophage cells.

Rohitukine inhibits NF-κB activation induced by LPS and other inflammatory agents

Rohitukine (referred to as RHK) is a bioactive chromone alkaloid isolated from the leaves of plant Dysoxylum binectariferum, which has been reported to possess diverse pharmacological properties for the treatment of inflammatory bowel disease (IBD), diarrhoea and anti-lipidemic. However, the underlying mechanism by which RHK exerts its anti-inflammatory activity has not yet demonstrated. This study aimed to elucidate the anti-inflammatory mechanism of RHK using lipopolysaccharide (LPS) - stimulated J774A.1 macrophage cells and in-vivo inflammatory models. Results demonstrated that RHK treatment could significantly decrease the LPS-induced production of nitric oxide, prostaglandin E2 (PGE2), interleukins (ILs) and tumour necrosis factor (TNF)-α in J774A.1 cells. Molecular studies revealed that RHK inhibited the activation of upstream mediator nuclear factor-κB by suppressing the phosphorylation of IκBα and p65. In in-vivo experiments showed prominent anti-inflammatory activity of RHK. Thus, RHK could be considered as a promising candidate for the treatment of inflammatory diseases.

Dopamine Alters Lipopolysaccharide-Induced Nitric Oxide Production in Microglial Cells via Activation of D1-Like Receptors

Dopamine (DA) is important in the maintenance of normal nervous system function. DA is the target of multiple drugs, and it induces critical alterations in immune cells. However, these impacts are controversial, and the mechanism remains unclear. In the present study, we treated BV-2 microglial cells and primary microglia with DA and measured the changes in cytokines. We also identified the expression of DA receptors (DRs) using confocal and immunofluorescent microscopy. Specific agonists and antagonists of D1-like DRs (D1DR and D5DR) were used to observe alterations in cytokines. Western blot and siRNA interference were performed to investigate the involvement of the downstream signaling molecules of DRs. We also measured changes in mitogen-activated protein kinases (MAPKs) and the nuclear factor-kappa B (NF-κB) signaling pathway and assessed their involvement using inhibitors. We found that DA alone produced no effects on IL-6, TNF-α or nitric oxide (NO) production, and it inhibited lipopolysaccharide (LPS)-induced NO in microglial cells. Microglia expressed a high abundance of D1-like DRs (D1DR and D5DR). The agonists inhibited NO production, and antagonists reversed the DA-induced suppression of NO. Adenylatec cyclase (AC), cyclic adenosine monophosphate (cAMP) and protein kinase A (PKA) mediated DA function, and cAMP-response element binding protein (CREB) was not involved. ERK1/2 and NF-κB, but not p-38 or JNK, played roles in DA-suppressed NO generation via altering inducible nitric oxide synthase (iNOS) transcription. These data illustrate that DA modulates LPS-induced NO production via the AC/cAMP-PKA-ERK1/2-NF-κB-iNOS axis in mouse microglia, and D1-like DRs are involved. The present study provides functional evidence for an essential role of DA in immunoregulation.

Cycloartane triterpenoids from Actaea vaginata with anti-inflammatory effects in LPS-stimulated RAW264.7 macrophages

Five undescribed cycloartane triterpenoids, including two cycloartane trinor-triterpenoids, were isolated from a 70% ethanol extract of the whole plant of Actaea vaginata (Ranunculaceae), together with thirteen known cycloartane triterpenoids. Their structures were determined by spectroscopic techniques and quantum chemical calculations for intramolecular noncovalent interactions with reduced density gradient method. All compounds were evaluated for their anti-inflammatory effects by a lipopolysaccharide (LPS)-stimulated nitric oxide (NO) production model in RAW264.7 macrophage cells, and some showed potent inhibitory effects with IC50 values ranging from 5.0 to 24.4 μM. Further mechanism studies showed that one compound dose-dependently suppressed LPS-induced NO production and pro-inflammatory cytokines secretion, and decreased the expression of iNOS, through inhibiting NF-κB activation.

Characterization of grass carp (Ctenopharyngodon idella) beta-defensin 1: implications for its role in inflammation control.

Considering that fish grows in a complex aquatic environment, there is an increasing interest in fish β-defensins, which is an important group of antimicrobial peptides (AMPs). In this study, grass carp (Ctenopharyngodon idella) β-defensin 1 (gcdefb1) was isolated using homology cloning technology. Tissue distribution assay showed that gcdefb1 transcripts were expressed with the highest levels in brain and liver, followed by some mucous tissues. To examine gcDefb1 bioactivities, the recombinant gcDefb1 proteins fused with thioredoxin tag protein (Trx) (Trx-Defb1) were induced for production in Escherichia coli Rosetta-gami2(DE3)pLysS under optimal expression conditions. The antibacterial activity of Trx-Defb1 against Aeromonas hydrophila was assessed and its minimum inhibitory concentration (MIC) was 36μM. Interestingly, Trx-Defb1 significantly inhibited LPS-induced Tnf-α (gcTnf-α) secretion and nitric oxide production in grass carp head kidney monocytes/macrophages (HKM), although Trx-Defb1 alone had no effect. Our studies provide the first evidence of fish β-defensin 1 engaging in both antimicrobial and inflammation suppression process.

Anti-inflammatory and anti-oxidative effects of Centella asiatica extract in lipopolysaccharide-stimulated BV2 microglial cells

Background: Neuroinflammation and oxidative stress mediated by microglial activation have been reported to play a critical role in the pathogenesis of neurodegenerative diseases. Therefore, inhibition of microglial activation using herbal medicine may be a potential candidate for the treatment of such diseases. Objective: The goal of this study was to investigate the anti-inflammatory and anti-oxidative effects of Centella asiatica extract (CA) on lipopolysaccharide (LPS)-stimulated BV2 microglial cells. Methods: BV2 microglial cells were treated with LPS in the presence or absence of CA extract. The levels of nitric oxide (NO), tumor necrosis factor-α (TNF-α) and reactive oxygen species (ROS) was measured using Griess reagent assay, enzyme-linked immunosorbent assay (ELISA) assay and CM-H2DCFDA, respectively. The nuclear levels of nuclear factor kappa B (NF-kB) p65 were detected using immunofluorescence and ELISA assay. Results: CA treatment resulted in significant and concentration-dependently reduced the LPS-induced production of NO, TNF-α, and ROS compared to the untreated group. CA treatment exerted an anti-inflammatory effect by suppressing NF-kB p65 translocation and the activation of Akt and the extracellular-signal-regulated kinase 1/2 (ERK1/2) pathway in LPS-stimulated BV2 cells. Conclusion: Taken together, these results show that CA exerts antioxidative activity by suppressing ROS production and that it exerts anti-inflammatory activity by suppressing LPS-induced NO and TNF-α production in BV2 microglial cells. These effects may occur through inhibition of Akt and the ERK1/2-mediated NF-kB pathway. The results presented here, coupled with traditional therapeutic claims, suggest that CA may be beneficial for treating neurodegenerative diseases mediated by microglial cells. Abbreviations used: AD: Alzheimer's disease; ALS: Amyotrophic lateral sclerosis; CA: Centella asiatica; DMSO: Dimethyl sulfoxide; DMEM: Dulbecco's modified Eagle's medium; ECL: Enhanced chemiluminescence; ELISA: Enzyme-Linked immunosorbent assay; ERK1/2: Extracellular-signal-regulated kinase 1/2; FBS: Fetal bovine serum; LPS: Lipopolysaccharide; MS: Multiple sclerosis; MSU: Mahasarakham University; NF-kB: Nuclear factor kappa B; NO: Nitric oxide; PD: Parkinson's disease; ROS: Reactive oxygen species; SD: Standard deviation; TNF-α: Tumor necrosis factor-α.

Antcamphin M Inhibits TLR4-Mediated Inflammatory Responses by Upregulating the Nrf2/HO-1 Pathway and Suppressing the NLRP3 Inflammasome Pathway in Macrophages.

The medicinal mushroom Antrodia cinnamomea has been demonstrated to have anti-inflammatory properties. However, the bioactive compounds in A. cinnamomea need further investigation. The present study aimed to understand the mechanism of action of antcamphin M, an ergostanoid isolated from A. cinnamomea mycelium and to clarify its underlying mechanisms of action. RAW264.7 cells were pretreated with the indicated concentrations of antcamphin M, prior to stimulation with lipopolysaccharide (LPS). Cell viability, production of nitric oxide (NO), prostaglandin E2 (PGE, cytokines, and chemokines, as well as the inflammation-related signaling pathways were investigated. The study revealed that antcamphin M significantly decreased the LPS-induced production of NO, PGE2, pro-inflammatory cytokines, and keratinocyte chemoattractant CXCL1 (KC), along with the levels of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins without significant cytotoxicity, indicating it had a better anti-inflammatory activity than that of gisenoside Rb1 and Rg1. Additionally, antcamphin M significantly inhibited the activation of MAPKs (p38, ERK, and JNK), NFB, and components of the NLRP3 inflammasome (NLRP3, ASC, and caspase-1) signaling pathways and also increased the levels of nuclear factor erythroid-2-related factor (Nrf2) and heme oxygenase-1 (HO-1). These findings suggest that antcamphin M possesses potent anti-inflammatory activities and could be a potential candidate for the development of anti-inflammatory drugs.

Anti-inflammatory effects of alkaloid enriched extract from roots of Eurycoma longifolia Jack

Objective: To examine the in vitro and in vivo anti-inflammatory effects of the alkaloid enriched extract (ELA) from the roots of Eurycoma longifolia. Methods: The in vitro antiinflammatory effects of ELA were evaluated by examining its inhibitory activities against nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) expressions in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. The level of NO produced in the culture media was determined by Griess method. The iNOS and COX-2 protein expressions were analyzed by Western blot. The in vivo effect of ELA was evaluated on LPS-induced septic shock in mice model. Mice mortality was monitored for 5 days after injection of LPS. The chemical contents of the ELA were determined by using various chromatographic and spectroscopic techniques. Results: The ELA was found to exhibit a significant anti-inflammatory effect in both in vitro and in vivo models. The results demonstrated that ELA dose-dependently inhibited LPS-induced NO production as well as the protein iNOS and COX-2 expressions. In the septic shock model, ELA dose-dependently protected mice from LPS-induced mortality. Further study on the isolated components of ELA indicated that 9,10-dimethoxycanthin-6-one may contribute significantly to the anti-inflammatory effects of the extract. Conclusions: These results suggest that ELA exhibits the anti-inflammatory activity via suppression of pro-inflammatory mediators such as NO, iNOS, and COX-2 and protects mice from LPS-induced mortality in septic shock model.

Nitric Oxide Inhibitory Constituents from the Fruits of Amomum tsao-ko

Bioactivity-guided fractionation of MeOH extract of the dried fruits of Amomum tsao-ko led to isolation of nine compounds (1 – 9). Their structures were elucidated by spectroscopic methods including extensive 1D and 2D-NMR, as alpinetin (1), naringenin-5-O-methyl ether (2), naringenin (3), hesperetin (4), 2′,4′,6′-trihydroxy-4-methoxy chalcone (5), tsaokoin (6), boesenbergin B (7), 4-hydroxyboesenbergin B (8), and tsaokoarylone (9). Of these, compound 8 was isolated from a natural source for the first time, which was previously reported as a synthetic product. The isolated compounds (1 – 9) were tested for their inhibitory effects on LPS-induced nitric oxide production in RAW 264.7 macrophages. Among them, three chalcone derivatives (compounds 5, 7, and 8) and a diarylheptanoid (compound 9) exhibited significant inhibitory activity on the NO production with IC50 values ranging from 10.9 to 22.5 µM.

Immunomodulation Properties of Solid-State Fermented Laetiporussulphureus Ethanol Extracts in Chicken Peripheral Blood Monocytes In Vitro

ABSTRACT Laetiporus sp. is recognized as a fungal species traditionally used for medicinal purposes. This study investigated the in-vitro effects of solid-state fermented Laetiporussulphureus ethanol extracts (LSE) for their immunomodulatory potential. Bioactive levels detected in the LSE on different days throughout the fermentation period revealed that the 12th day was the most efficient, with 7.19 ± 0.66 GAE/g DM crude phenolic content, 2.71 ± 0.03 UAE/g DM crude triterpenoid content, 12.93 ± 0.88 GCE/g DM crude polysaccharides, and 96.44 ± 0.2 mg/g DM ergosterol content. In-vitroLSE tests on chPBMC showed no cytotoxicity within a range of 0.05-1 mg/mL, but LPS-inhibited cell viability was improved, as well as LPS-induced nitric oxide (NO) production and mRNA levels of nuclear factor kappa B (NFκB), Toll-like receptor 4 (TLR4), inducible nitric oxide synthase (iNOS), and interleukin (IL)-1βwere attenuated Furthermore, the direct application of LSE on chPBMC showed a small but not significant increase in NFκB, TLR4, and iNOS mRNA expression compared with the control group. These results indicate the potential of LSE to modulate LPS-triggered inflammation processes involving TLR4 and NFκB mediation. However, further experiments are required to determine the specific pathway.

EtOAc extract of H. attenuatum Choisy inhibits inflammation by suppressing the NF-κB and MAPK pathways and modulating the gut microbiota

BackgroundHypericum attenuatum Choisy, a traditional Chinese herb, has been shown to be effective in the treatment of diseases associated with inflammation and has been used to treat rheumatic arthritis in China for centuries. However, the underlying mechanism of its anti-inflammatory effect is poorly understood. Hypothesis/PurposeIn this study, we aimed to investigate the anti-inflammatory mechanisms of EtOAc fractions of H. attenuatum Choisy (Ha-EtOAc) on lipopolysaccharide (LPS)-induced RAW264.7 macrophage inflammation and hypothesized that Ha-EtOAc could attenuate inflammation in the colon. Study designLPS was utilized to induce RAW264.7 cells inflammation. The anti-inflammatory effect of Ha-EtOAc in RAW264.7 cells was evaluated by measuring the inhibition ratio of nitric oxide (NO) production. Murine ulcerative colitis (UC) was induced by treatment with 2.5% dextran sulfate sodium (DSS). The basic indexes of the mice, including body weight, food intake and hematochezia, were recorded during mice experiments. MethodsThe expression levels of pro-inflammatory cytokines, including TNF-α, IL-6 and IL-1β, were measured by quantitative real-time PCR and western blot. Additionally, the influences of Ha-EtOAc on the NF-κB and MAPK signaling pathways were determined by western blot and immunofluorescence assays. In addition, the impact of Ha-EtOAc on gut microbiota of mice with UC was detected by 16S rDNA sequencing. ResultsHa-EtOAc inhibited the LPS-induced production of NO and decreased the release of TNF-α, IL-6 and IL-1β in RAW264.7 cells in a dose-dependent manner. In addition, pretreatment with Ha-EtOAc could suppress the nuclear translocation of p65 and the phosphorylation of Erk1/2, p38 and JNK. Ha-EtOAc treatment ameliorated murine UC, as reflected by a reduced body weight loss, improved colon shortening, alleviated mucosal damage and decreased releases of pro-inflammatory cytokines. Furthermore, Ha-EtOAc could modulate the composition of microbial communities. ConclusionOur results demonstrated that Ha-EtOAc exhibited anti-inflammatory effects mainly by suppressing the NF-κB and MAPK pathways, and Ha-EtOAc treatment may be a potent therapy for the treatment of ulcerative colitis.

Mycosporine-2-glycine exerts anti-inflammatory and antioxidant effects in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages

Mycosporine-like amino acids (MAAs) are a group of water-soluble low-molecular-weight secondary metabolites, which are well-documented UV-screening molecules and antioxidants. We have recently demonstrated that a rare MAA, mycosporine-2-glycine (M2G), efficiently inhibited the formation of advanced glycation end-products (AGEs). Because AGEs contribute significantly to the aging process, including the pathogenesis and progression of age-related diseases, the present study further evaluated anti-inflammatory effects of M2G using an in vitro model of RAW 264.7 macrophages. We measured the inflammatory signaling molecule nitric oxide (NO) under inflammatory stimulation by lipopolysaccharide (LPS), revealing that M2G diminished LPS-induced NO production. M2G inhibited NO production approximately 2–3-fold more potently than other MAAs, including shinorine, porphyra-334, and palythine. Transcriptional analyses revealed that M2G significantly suppressed iNOS and COX-2 expression. Therefore, M2G inhibits the production of inflammatory mediators by suppressing the NF-κB pathway. Furthermore, under H2O2-induced oxidative stress, M2G down-regulated Sod1, Cat, and Nrf2 expression. Our findings clearly demonstrate anti-inflammatory and antioxidant effects of M2G in LPS-stimulated RAW 264.7 macrophages. Structure-activity relationships of biologically active MAAs are also discussed.