Inflammation In RAW Research Articles

Mungbean seed coat water extract inhibits inflammation in LPS-induced acute liver injury mice and LPS-stimulated RAW 246.7 macrophages via the inhibition of TAK1/IκBα/NF-κB.

Inflammation plays an important role in pathogenesis and progression of many chronic diseases. Although, anti-inflammatory activities of mungbean have been suggested, the underlying mechanism have not been fully understood. The present study aimed to reveal the anti-inflammatory effects of mungbean seed coat water extract (MSWE) in lipopolysaccharide (LPS)-stimulated inflammation in RAW 246.7 macrophages and LPS-induced acute liver injury mice. MSWE pretreatment downregulated the elevated expression of inflammatory markers induced by LPS in the transcriptional and protein level. MSWE inhibited NF-κB activation through the suppression of phosphorylated p65 subunit, IκBα degradation, and transforming growth factor-β-activated kinases 1 (TAK1) phosphorylation in LPS-stimulated RAW 246.7 cells. Vitexin, the major flavonoid in MSWE showed similar effects. In in vivo experiments, we found that oral administration of MSWE downregulated iNOS expression in LPS-induced acute liver injury mice. The mRNA expression of inflammatory markers and macrophage infiltration was also decreased in the livers. Collectively, MSWE exerts anti-inflammatory role, in part possibly through its active compound vitexin, by inhibiting NF-κB activation via inhibition of TAK1 phosphorylation and IκBα degradation. This suggests that MSWE is beneficial to combat various inflammatory diseases.

Oral supplementation of fucoxanthin-rich brown algae extract ameliorates cisplatin-induced testicular damage in hamsters

Oxidative stress is recognized as a common pathology that affects up to half of all men infertile. Fucoxanthin possesses antioxidant activity, and several investigators have reported anti-inflammatory action. This study extracted powder of Sargassum glaucescens by acetone to obtained fucoxanthin rich-brown algae extract (FXE). The objective of this study was to evaluate the ameliorative effects of fucoxanthin extract from Sargassum glaucescens on lipopolysaccharide-induced inflammation in RAW264.7 macrophage cells and its protective effects of against Cisplatin (CP)-induced reproductive damage in hamsters. Eighty male Syrian hamsters were injected with and without CP, then daily oral gavage with various concentrations of fucoxanthin for 5 days. Treatment with FXE reduced the level of reactive oxygen species and malondialdehyde in RAW 264.7 cells and the rats’ testis as well as protective effects on mitochondrial membrane potential. The FXE administration also improved testosterone level and alpha-glucosidase activity. The sperm count also increased after treated with FXE, whereas sperm abnormality was reduced. Histopathological analysis showed that FXE successfully improved the seminiferous tubules morphology. According to these findings, fucoxanthin extract from Sargassum glaucescens can be used as an alternative for the treatment of testicular damage.

Modulation of LPS-induced inflammation in RAW264.7 murine cells by novel isoflavonoids from Millettia pulchra.

Millettia pulchra is a renowned anti-inflammatory herbal medicine in southeast provinces of China. However, the underlying anti-inflammation mechanism remained incompletely understood. Herein, four new isoflavones, pulvones A-D and eleven reported constituents were isolated from the stems of Millettia pulchra with their structures being elucidated by HRMS and NMR analysis. The anti-inflammatory activities of pulvones A and C were further evaluated due to the better inhibitory activity on nitric oxide production in LPS-stimulated RAW264.7 cells and no obvious cytotoxicity to RAW264.7 cells. Western blot showed that pulvones A significantly decreased the levels of iNOS and COX-2 proteins and pulvones C only decreased the level of iNOS protein. ELISA analysis demonstrated that pulvones A inhibited the production of both interleukin-6 (IL-6) and IL-1β while pulvones C showed better suppression effect on IL-1β production in LPS-stimulated RAW264.7 cells. Then, their potential inhibitory effects on NF-κB pathway were tested in LPS-stimulated RAW264.7 cells. Immunofluorescence and western blot assay showed that pulvones A and C reduced the nuclear translocation of NF-κB(p65) and interrupted IκB phosphorylation. The ADP-Glo™ kinase assay showed pulvones A and C could directedly inhibit the IKKβ kinase activity with the inhibitory rate of 40%, which were also verified by docking study. Collectively, these results suggested that pulvones A and C's anti-inflammatory effects were relevant to the interruption of NF-κB activation by inhibiting IKKβ kinase.

Protein Hydrolysates from Anchovy (Engraulis encrasicolus) Waste: In Vitro and In Vivo Biological Activities.

Fish waste utilization to obtain protein hydrolysates has been demonstrated to be a useful strategy to face both environmental and economic impacts while obtaining high-value products with remarkable biological and nutritional properties. In the present study, protein hydrolysates obtained from anchovy Engraulis encrasicolus (APH) by-products were assessed for their potential biological activities in both in vitro and in vivo models. The treatment with APH exerted a significant protection against LPS-induced inflammation in RAW 264.7 cells, decreasing the protein expression of pro-inflammatory mediators (i.e., COX-2) and inhibiting the nuclear translocation of NF-κB through IκB-α. Moreover, APH modulated the expression of iNOS, MnSOD and HO-1, thus decreasing the severity of oxidative stress. The supplementation of APH in the diet of ApoE knockout mice down-regulated the proinflammatory cytokines (i.e., TNF-α, IL-1α, IL-1β, IL-6) in both aorta and heart tissues, and modulated the expression of oxidative stress-related genes (Cu/ZnSod, MnSod, Cat, Gpx and Ho), indicating that APH can exert a beneficial role, having anti-inflammatory and antioxidant activities. The nutritional properties of APH, together with their biological activities herein reported, highlight the possibility of obtaining bioactive molecules from fish waste and encourage their use as potential nutraceuticals in food and pharmaceutical industries in the next future.

Artemisia iwayomogi (Dowijigi) inhibits lipopolysaccharide-induced inflammation in RAW264.7 macrophages by suppressing the NF-κB signaling pathway.

Inflammatory diseases are an important health concern and have a growing incidence worldwide. Thus, developing novel and safe drugs to treat these disorders remains an important pursuit. Artemisia iwayomogi, locally known as Dowijigi (DJ), is a perennial herb found primarily in Korea and is used to treat various diseases such as hepatitis, inflammation and immune disorders. In the present study, the anti-inflammatory effects of a polyphenolic extract from the DJ flower (PDJ) in lipopolysaccharide (LPS)-stimulated mouse macrophage RAW264.7 cells were investigated. Cell cytotoxicity was assessed using the MTT assay. The production of nitric oxide (NO) and prostaglandin E2 (PGE2) was measured by Griess and ELISA analysis, respectively. The expression levels of inducible nitric oxide (iNOS) and cyclooxygenase-2 (COX2) were examined by western blot analysis. Reverse transcription-quantitative PCR was performed to detect the mRNA expression levels of pro-inflammatory cytokines, including tumor necrosis factor α (TNFα), interleukin (IL)-6 and IL-1β, as well as COX2 and iNOS. The production of NO and PGE2 was significantly decreased following treatment with PDJ. The mRNA expression levels of TNFα, IL-6, IL-1β, COX2 and iNOS were significantly decreased in LPS-induced PDJ co-treated cells compared with the group treated with LPS alone. Western blot analysis indicated that PDJ downregulated the LPS-induced expression of iNOS and COX2, as well as the expression of NF-κB proteins. In conclusion, the present study demonstrated that PDJ exerted anti-inflammatory effects in LPS-induced macrophage cells by suppressing the NF-κB signaling pathway. Therefore, PDJ may be used as a potential therapeutic agent in inflammation.

Date palm and saw palmetto seeds functional properties: antioxidant, anti-inflammatory and antimicrobial activities

The agricultural by-products are a significant source of health benefiting bioactive compounds. In this trend, the phenolic and flavonoid contents and functional properties of date palm seeds (DPS) and saw palmetto seeds (SPS) extracts were evaluated in this study. Considerable phenolic and flavonoid contents of 11.8, 7.75 mg GAE/g seed and 3.13, 1.1 mg CE/g seed were detected in DPS ethanol and SPS acetone extracts, respectively. The protocatechuic acid was the major compound in SPS and DPS extracts and represented 1.41 and 1.1 mg/g seed, respectively as well as similar phenolic compounds were detected using HPLC analysis. The DPS and SPS phenolic compounds possessed a strong antioxidant activity with IC50 values of 10.0, 2.2 and 2.0, 0.6 µg GAE/mL, using the DPPH and ABTS assays, respectively. The phenolic compounds of DPS and SPS extracts showed a potent and broad anti-bacterial activity against clinical multiple drug resistance bacterial strains with lower MIC values besides an effective anti-fungal activity against a number of human pathogenic fungal strains. Interestingly, in a model of LPS-induced inflammation in RAW 264.7 cells, DPS and SPS showed efficient anti-inflammatory effects to inhibit the iNOS protein expression and activity (NO release).

4'-O-β-D-glucosyl-5-O-methylvisamminol ameliorates imiquimod-induced psoriasis-like dermatitis and inhibits inflammatory cytokines production by suppressing the NF-κB and MAPK signaling pathways.

Psoriasis is a chronic inflammatory skin disorder in humans, and the inflammatory reaction plays an important role in development and onset of psoriasis. 4'-O-β-D-glucosyl-5-O-methylvisamminol (4GMV) is one of the major active chromones isolated from Saposhnikoviae divaricata (Turcz.) Schischk, which has been reported to exhibit excellent anti-inflammatory activities. However, the possible therapeutic effect on psoriasis and underlying mechanism has not been reported. Thus, the aim of this study was to investigate the protective effect of 4GMV on the imiquimod (IMQ)-induced psoriasis-like lesions in BALB/c mice and the anti-inflammatory effect on the lipopolysaccharide (LPS)-induced inflammation in RAW264.7 macrophages. The results demonstrated that 4GMV decreased IMQ-induced keratinocyte proliferation and inflammatory cell infiltration. Moreover, 4GMV treatment significantly inhibited the production of NO, PEG 2, and cytokines such as interleukin (IL)-1β, IL-6, interferon (IFN)-γ, and IL-22 in LPS-stimulated RAW264.7 macrophages. 4GMV also suppressed the LPS-upregulated protein expressions of iNOS and COX-2 in a dose-dependent manner. Furthermore, qRT-PCR analysis showed that 4GMV down-regulated the mRNA level of IL-1β and IL-6 expression. Further studies by western blot indicated that 4GMV inhibited the activation of upstream mediator NF-κB by suppressing the expression of TLR4 and the phosphorylation of IκBα and p65. The phosphorylation of JNK, p38, and ERK were also markedly reversed by 4GMV in LPS-treated RAW264.7 macrophages. Taken together, these results demonstrated that 4GMV showed a protective effect in IMQ-induced psoriasis-like mice and inhibited inflammation through the NF-κB and MAPK signaling pathways, indicating that 4GMV might be a potential therapeutic drug for psoriasis.

Ethyl acetate fraction of flavonoids from Polygonum hydropiper L. modulates pseudorabies virus-induced inflammation in RAW264.7 cells via the nuclear factor-kappa B and mitogen-activated protein kinase pathways.

Pseudorabies virus (PRV) infection leads to severe inflammatory responses and tissue damage, and many natural herbs exhibit protective effects against viral infection by modulating the inflammatory response. An ethyl acetate fraction of flavonoids from Polygonum hydropiper L. (FEA) was prepared through ethanol extraction and ethyl acetate fractional extraction. An inflammatory model was established in RAW264.7 cells with PRV infection to evaluate the anti-inflammatory activity of FEA by measuring cell viability, nitric oxide (NO) production, reactive oxygen species (ROS) release, and mRNA expression of inflammatory factors, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). Its functional mechanism was investigated by analyzing the phosphorylation and nuclear translocation of key proteins in the nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. Our findings indicate that PRV induced inflammatory responses in RAW264.7 cells, and the responses were similar to that in lipopolysaccharide (LPS)-stimulated cells. FEA significantly suppressed NO synthesis and down-regulated both expression and secretion of COX-2, iNOS, and inflammatory cytokines (P<0.05 or P<0.01). FEA also reduced NF-κB p65 translocation into the nucleus and decreased MAPK phosphorylation, indicating that the NF-κB/MAPK signaling pathway may be closely related to the inflammatory response during viral infection. The findings suggested the potential pharmaceutical application of FEA as a natural product that can treat viral infections due to its ability to mitigate inflammatory responses.

Fucoxanthin alleviates palmitate-induced inflammation in RAW 264.7 cells through improving lipid metabolism and attenuating mitochondrial dysfunction.

In this study, we aimed to examine the effects of fucoxanthin on inflammation triggered by palmitate in macrophages. Raw 264.7 cells were treated with palmitate with or without fucoxanthin co-treatment. Fucoxanthin greatly alleviated palmitate-induced decrease in cell viability and loss of mitochondrial membrane potential. Fucoxanthin also significantly attenuated the palmitate-induced transcriptional expression of Il-6, Il-1β, Tnfα and Nlrp3 inflammasomes and increased the expression of Tgfb. In addition, fucoxanthin decreased triglyceride accumulation induced by palmitate through enhancing the expression of Cpt1a, Pparg and other lipid metabolism genes. Inhibition of CPT1a by etomoxir attenuated the anti-inflammatory effect of fucoxanthin. Furthermore, fucoxanthin increased AMPK phosphorylation and AMPKa1 knockdown by its specific siRNA diminished protective function. In addition, fucoxanthin restored palmitate-mediated mitochondrial dysfunction and improved mitophagy-related gene expression. These findings suggest that fucoxanthin could attenuate free fatty acid-induced inflammation in macrophages through modulating lipid metabolism and mitigating mitochondrial dysfunction.

The Aqueous Extract of Radio-Resistant Deinococcus actinosclerus BM2T Suppresses Lipopolysaccharide-Mediated Inflammation in RAW264.7 Cells.

Deinococcus actinosclerus BM2T (GenBank: KT448814) is a radio-resistant bacterium that is newly isolated from the soil of a rocky hillside in Seoul. As an extremophile, D. actinosclerus BM2T may possess anti-inflammatory properties that may be beneficial to human health. In this study, we evaluated the anti-inflammatory effects of BM2U, an aqueous extract of D. actinosclerus BM2T, on lipopolysaccharide (LPS)-mediated inflammatory responses in RAW264.7 macrophage cells. BM2U showed antioxidant capacity, as determined by the DPPH radical scavenging (IC50 = 349.3 μg/ml) and ORAC (IC50 = 50.24 μg/ml) assays. At 20 μg/ml, BM2U induced a significant increase in heme oxygenase-1 (HO-1) expression (p < 0.05). BM2U treatment (0.2-20 μg/ml) significantly suppressed LPS-induced increase in the mRNA expression of proinflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6 (p < 0.05). BM2U treatment also suppressed the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), which are involved in the production of inflammatory mediators. BM2U treatment also inhibited the activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs): JNK, ERK, and p-38 (p < 0.05). Collectively, BM2U exhibited anti-inflammatory potential that can be exploited in attenuating inflammatory responses.

Anti-inflammatory effect of water extracts obtained from doenjang in LPS-stimulated RAW 264.7 cells

Abstract The effect of water extracts of doenjang (WED) on cyclooxygenase pathway and cytokine production in lipopolysaccharide (LPS)-treated RAW 264.7 macrophage cells was investigated. WED was fractionated by ultrafiltration into five individual groups of molecular weights. All of the WED fractions significantly inhibited the production of prostaglandin E2 (PGE2) and expression of cyclooxygenase-2 (COX-2) in LPS-stimulated RAW 264.7 macrophages. Furthermore, each of the WED fractions significantly decreased production of pro-inflammatory cytokine such as tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) (p<0.05). The fraction between 10 to 30 kDa of WED showed the highest inhibition of pro-inflammatory cytokine production, LPS-induced COX-2 expression and PEG2 production. These results suggest that WED fractions may have the anti-inflammatory effect via the stimulus of COX-2 and TNF-α in LPS-stimulated inflammation in RAW 264.7 cells.

Dieckol: an algal polyphenol attenuates urban fine dust-induced inflammation in RAW 264.7 cells via the activation of anti-inflammatory and antioxidant signaling pathways

Fine dust-associated complications related to human health are one of the major issues in the East-Asia region. In the present study, we evaluated anti-inflammatory effect of dieckol in fine dust-stimulated RAW 264.7 macrophage cells and its biological mechanism. The result showed that the exposure of macrophages to fine dust induced the productions of nitric oxide (NO), prostaglandin E2 (PGE2), and the mRNA expression levels of inflammatory mediators such as inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 whereas it was significantly attenuated by the treatment of dieckol. In addition, fine dust increased the pro-inflammatory cytokines such as interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α that were down-regulated by dieckol. Interestingly, dieckol protected macrophages against cell damages via reducing the fine dust-caused intracellular reactive oxygen species (ROS) generation via induction of superoxide dismutase production as well as the HO-1/Nrf2 signaling activation. In conclusion, dieckol protects RAW 264.7 cells against fine dust-induced inflammation and oxidative stress via inducing anti-inflammatory and antioxidant mechanisms.

New coumarins isolated from the stem bark of Fraxinus rhynchophylla inhibit human neutrophil elastase and LPS-induced inflammation in RAW 264.7 cells

Two new coumarins (1 and 2), together with six known compounds (3–8), were isolated from the stem bark of Fraxinus rhynchophylla. The structures of these compounds were established by extensive spectroscopic studies and chemical evidence. The inhibitory activities of the isolated compounds (1–8) against human neutrophil elastase (HNE) were evaluated in vitro; all compounds tested exhibited inhibitory effects against HNE activity, with IC50 values ranging from 3.6–74.3 μM. Among the compounds tested, compounds 2 and 8 exhibited considerable HNE inhibitory activity, with IC50 values of 3.6 and 9.6 μM, respectively. The mechanism by which the two active compounds (2 and 8) inhibited HNE was noncompetitive inhibition, with inhibition constant (Ki) values of 2.2 and 6.8 μM, respectively. Furthermore, compounds 2 and 8 dose-dependently inhibited LPS-induced NO production in RAW 264.7 cells. Consistent with these findings, they also suppressed LPS-induced expression of iNOS and COX-2 at the protein level in RAW 264.7 cells.

PTP1B promotes macrophage activation by regulating the NF-κB pathway in alcoholic liver injury

Alcoholic liver injury (ALI) is a part of alcohol-related liver diseases. These diseases include steatohepatitis, alcoholic fibrosis, cirrhosis and hepatocellular carcinoma (HCC). Accumulating data indicates that alcohol metabolism and circulating endotoxin/lipopolysaccharide (LPS) contribute to macrophage activation, which leads to the development of ALI. Protein tyrosine phosphatase 1B (PTP1B) has been shown to be involved in many tissue inflammations as well as liver fibrosis; however, the role of PTP1B in ALI is still unclear. In this study, PTP1B expression was elevated in liver tissues and primary macrophages isolated from EtOH-fed mice. Moreover, PTP1B expression was elevated in RAW264.7 cells stimulated with alcohol and LPS. Additional studies showed that silencing of PTP1B reduced the inflammatory response and expression of inflammatory cytokines such as IL-1β, IL-6 and TNF-α, while overexpression of PTP1B induced inflammation in RAW264.7 cells. In addition, we found that NF-κB pathway was activated in RAW264.7 cells stimulated with alcohol and LPS, and PTP1B silencing or overexpression could regulate NF-κB signaling. In conclusion, this study revealed the function of PTP1B in ALI via its regulation of the NF-κB signaling pathway and may provide theoretical support for further research on ALI.

Myxopyrum serratulum ameliorates airway inflammation in LPS-stimulated RAW 264.7 macrophages and OVA-induced murine model of allergic asthma

Ethnopharmacological relevanceMyxopyrum serratulum A. W. Hill. (Oleaceae) is a traditionally used Indian medicinal plant for the treatment of cough, asthma and many other inflammatory diseases. Aim of the studyIn this study, the protective effects of M. serratulum on airway inflammation was investigated in ovalbumin (OVA)-induced murine model of allergic asthma and lipopolysaccharide (LPS)-stimulated inflammation in RAW 264.7 murine macrophages, and the possible mechanisms were elucidated. Materials and methodsThe phytochemicals present in the methanolic leaf extract of M. serratulum (MEMS) were identified by reverse phase high performance liquid chromatography (RP-HPLC) analysis. In vitro anti-inflammatory activity of MEMS were evaluated by estimating the levels of nitric oxide (NO), reactive oxygen species (ROS) and cytokines (IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-10, IL-12, IL-17A, IFN-γ, TNF-α, G-CSF and GM-CSF) in LPS-stimulated RAW 264.7 macrophages. In vivo anti-asthmatic activity of MEMS was studied using OVA-induced murine model. Airway hyperresponsiveness (AHR), was measured; total and differential cell counts, eosinophil peroxidase (EPO), prostaglandin E2 (PGE2), NO, ROS, and cytokines (IL-4, IL-5 and IL-13), were estimated in bronchoalveolar lavage fluid (BALF). Serum total IgE level was measured; and the histopathological changes of lung tissues were observed. The expressions of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in lung tissue homogenates were detected by Western blot. ResultsThe chromatographic analysis of MEMS identified the presence of gallic acid, protocatechuic acid, catechin, ellagic acid, rutin, p-coumaric acid, quercetin, naringenin and apigenin. MEMS (125 and 250 μg/mL) dose-dependently reduced the levels of NO, ROS and pro-inflammatory cytokines in LPS-stimulated RAW 264.7 macrophages. MEMS (200 and 400 mg/kg, p.o.) significantly (p < 0.05) alleviated AHR; number of inflammatory cells, EPO, PGE2, NO, ROS, and cytokines (IL-4, IL-5 and IL-13) in BALF; serum total IgE and the histopathological changes associated with lung inflammation. Western blot studies showed that MEMS substantially suppressed COX-2 and iNOS protein expressions in the lung tissues of OVA-sensitized/challenged mice. ConclusionsThe present study corroborates for the first time the ameliorative effects of MEMS on airway inflammation by reducing the levels of oxidative stress, pro-inflammatory cytokines and inhibiting COX-2, iNOS protein expressions, thereby validating the ethnopharmacological uses of M. serratulum.

A silkworm based silk gland bioreactor for high-efficiency production of recombinant human lactoferrin with antibacterial and anti-inflammatory activities

BackgroundSilk glands are used by silkworms to spin silk fibers for making their cocoons. These have recently been regarded as bioreactor hosts for the cost-effective production of other valuable exogenous proteins and have drawn wide attention.ResultsIn this study, we established a transgenic silkworm strain which synthesizes the recombinant human lactoferrin (rhLF) in the silk gland and spins them into the cocoon by our previously constructed silk gland based bioreactor system. The yield of the rhLF with the highest expression level was estimated to be 12.07 mg/g cocoon shell weight produced by the transgenic silkworm strain 34. Utilizing a simple purification protocol, 9.24 mg of the rhLF with recovery of 76.55% and purity of 95.45% on average could be purified from 1 g of the cocoons. The purified rhLF was detected with a secondary structure similar with the commercially purchased human lactoferrin. Eight types of N-glycans which dominated by the GlcNAc (4) Man (3) (61.15%) and the GlcNAc (3) Man (3) (17.98%) were identified at the three typical N-glycosylation sites of the rhLF. Biological activities assays showed the significant evidence that the purified rhLF could relief the lipopolysaccharide (LPS)-induced cell inflammation in RAW264.7 cells and exhibit potent antibacterial bioactivities against the Escherichia coli (E. coli) and Bacillus subtilis.ConclusionsThese results show that the middle silk gland of silkworm can be an efficient bioreactor for the mass production of rhLF and the potential application in anti-inflammation and antibacterial.

Inhibition of HDAC6 attenuates LPS-induced inflammation in macrophages by regulating oxidative stress and suppressing the TLR4-MAPK/NF-κB pathways

BackgroundHistone deacetylase 6 (HDAC6) has been considered as an important regulator in the development of inflammatory diseases. However, the mechanism of HDAC6 in regulating inflammatory responses has not been fully determined. In the present study, we aim to investigate the role and mechanisms of HDAC6 in regulating inflammation in lipopolysaccharide (LPS)-activated macrophages. MethodsFlow cytometry was used to determine a suitable treatment dosage of ACY-1215 on lipopolysaccharide (LPS)-activated macrophages for the present study. The RAW264.7 macrophages were divided into normal, LPS-treated, and ACY-1215 treated groups, respectively. For the ACY-1215 group, ACY-1215 (10 μM) was added to the medium 2 h prior to treatment with LPS (1 μg/ml) for 24 h. In this study, ROS, inflammatory cytokines, the ultrastructure of mitochondria, mitochondrial membrane potential, RNA and protein expression assay were detected respectively. Subsequently, the effect of HDAC6 knockdown on inflammatory response in LPS-activated RAW264.7 macrophages was also detected. ResultsInhibition of HDAC6 inhibited the overproduction of ROS and suppressed the expression of pro-inflammatory cytokines such as TNF-α, IL-1β, and IL-6 in LPS-activated RAW264.7 cells. Pretreatment with ACY-1215 could normalize the ultrastructure of mitochondria and mitochondrial membrane potential in LPS-activated macrophages. Moreover, the protein expression of TLR4, Nrf2, HO-1 and the activation of MAPK and NF-κB signaling pathways were normalized by the inhibition of HDAC6. ConclusionsInhibition of HDAC6 exhibited protective role against LPS-induced inflammation in RAW264.7 cells by regulating oxidative stress and suppressing the activation of TLR4- MAPK/NF-κB signaling pathway.

Investigating the Antioxidant Characteristics of Saccharina Latissima and Its Ability to Reduce Inflammation in RAW 264.7 Cells (P06-091-19)

ObjectivesThe goal of this study is to understand the anti-inflammatory characteristics of Saccharina latissima (sugar kelp). Sugar kelp is a brown macroalga that grows readily off the coast of Maine. Other seaweeds are known to contain bioactive chemicals that reduce inflammation—a contributing factor to metabolic syndrome and type 2 diabetes. It is hypothesized that injuring farmed sugar kelp by trimming the kelp may increase the beneficial bioactives and promote anti-inflammatory effects. The specific aims are (1) to produce extracts of Maine-grown sugar kelp through accelerated solvent extraction (ASE), (2) to measure the samples’ antioxidant capacity, and (3) to investigate the samples’ anti-inflammatory effect in vitro. MethodsSugar kelp samples were freeze-dried and extracts were produced using ASE. Total phenolic content was measured using the Folin-Ciocalteau assay, and radical scavenging capacity was measured with a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The sugar kelp extracts were tested for cytotoxicity in RAW 264.7 macrophages using a 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Lipopolysaccharide (LPS) was used to induce inflammation in the cells, and the attenuation effect of extract doses ranging from 12.5–50 μg total phenolics (TP)/mL was observed by measuring nitric oxide (NO) secretion with the Griess assay. ResultsPreliminary data shows that sugar kelp contains polyphenols (8.4–16.0 mg gallic acid equivalent/g dried biomass) and radical scavenging capacity (IC50 = 61.8–79.5 μg/mL). The data did not demonstrate the trimming the kelp has a beneficial effect to increase phenolic compounds. The polyphenolic contents of the trimmed samples were lower than the untrimmed (9.5 vs. 13.1 mg gallic acid equivalent/g dried biomass). The radical scavenging capacity decreased when the samples were trimmed (14.7%). The greatest decrease in NO production was at a concentration of 50 μg TP/mL for a trimmed sample (up to 78.5%), which supports the hypothesis. ConclusionsThis data suggests that sugar kelp may be a good source of antioxidants and trimmed samples may contain additional bioactives to help decrease inflammation. Further investigation is needed to confirm the hypothesis. Funding SourcesThe University of MaineThe University of New England

Anti-Inflammatory Effect of Ecklonia cava Extract on Porphyromonas gingivalis Lipopolysaccharide-Stimulated Macrophages and a Periodontitis Rat Model.

Ecklonia cava, an edible marine brown alga (Laminariaceae), is a rich source of phlorotannins. This study aimed to investigate the anti-inflammatory effect of Ecklonia cava ethanol extract (ECE, dieckol 10.6%, w/w) on Porphyromonas gingivalis lipopolysaccharide-stimulated inflammation in RAW 264.7 cells and in ligature-induced periodontitis in rats. The levels of nitric oxide (NO) and prostaglandin E2 were decreased by more than half on treatment with 100 μg/mL ECE. Downregulated tumor necrosis factor-α, interleukin (IL)-1β, and IL-6 gene expression confirmed the anti-inflammatory properties of ECE. ECE treatment upregulated heme oxygenase-1 (HO-1) expression by 6.3-fold and increased HO-1/nuclear factor erythroid 2-related factor 2 (Nrf-2) signaling decreased nuclear factor-κB (NF-κB) translocation. ECE administration (400 mg/kg) significantly reduced gingival index, restricted tooth mobility, and prevented alveolar bone loss (p < 0.05). These beneficial effects were due to decreased inflammatory cell infiltration, IL-1β production, and matrix metalloproteinase expression in gingival tissues. The ratio of receptor activator of nuclear factor-κB ligand (RANKL)/osteoprotegerin, a biomarker of periodontitis and osteolysis, was significantly decreased by ECE administration (p < 0.05). Thus, ECE has potential therapeutic effects for the alleviation of periodontal disease.

Inhibitory Effect of Jing-Fang Powder n-Butanol Extract and Its Isolated Fraction D on Lipopolysaccharide-Induced Inflammation in RAW264.7 Cells

The Jing-Fang powder n-butanol extract (JFNE) has anti-inflammatory properties; however, its active ingredient remains unknown. In addition, the mechanism by which JFNE exerts its anti-inflammatory effects on lipopolysaccharide (LPS)-induced inflammation in RAW264.7 cells is yet to be explored. In this study, JFNE was isolated by chromatography to obtain fraction D. We found that pretreatment of LPS-induced RAW264.7 cells with JFNE and fraction D for 3 hours significantly reduced the levels of nitric oxide (NO), interleukin (IL)-1β, and tumor necrosis factor-α (TNF-α) in the supernatant of cell cultures, and fraction D could also reduce the level of IL-6. In addition, JFNE and fraction D significantly reduced the mRNA expression of inducible NO synthase (iNOS), IL-6, IL-1β, and TNF-α JFNE and fraction D significantly inhibited the phosphorylation of proteins and mRNA expression levels of phosphoinositide 3-kinase (PI3K) and protein kinase B (PKB/AKT). Moreover, JFNE and fraction D significantly decreased the mRNA expression of iNOS, v-rel reticuloendotheliosis viral oncogene homolog A (RELA), and nuclear factor of κ light polypeptide gene enhancer in B cells 1 (NF-κB1), whereas an increase in the mRNA expression of conserved helix-loop-helix ubiquitous kinase (CHUK) was observed. In addition, JFNE and fraction D downregulated the protein expression of iNOS, nuclear factor-κB (NF-κB) (p50), and phosphorylated NF-κB (p65). These results show that JFNE and its isolated fraction D exert specific anti-inflammation properties in LPS-stimulated RAW264.7 cells that are regulated by inhibition of the PI3K/Akt and NF-κB signaling pathways.