Acetate Suppresses Lipopolysaccharide-stimulated Nitric Oxide Production in Primary Rat Microglia but not in BV-2 Microglia Cells

2020 ◽  
Vol 14 (2) ◽  
pp. 253-260
Author(s):  
Mitsuaki Moriyama ◽  
Yasunori Nishimura ◽  
Ryosuke Kurebayashi ◽  
Tomoki Minamihata ◽  
Kenji Kawabe ◽  
...  

Aims: To show that acetate attenuates neuroinflammatory responses in activated microglia. Background: Dietary acetate supplementation alleviates neuroglial activation in a rat model of neuroinflammation induced by intraventricular administration of lipopolysaccharide (LPS). However, the precise mechanism(s) underlying the anti-inflammatory effect of acetate is not fully understood. Objective: To determine whether acetate has inhibitory effects on LPS-induced neuroinflammatory responses in microglia. Methods: We examined LPS-stimulated nitric oxide (NO) production in primary rat microglia and BV-2 cells. Protein expression of inducible NO synthase (iNOS) was determined by western blot analysis. The intracellular generation of reactive oxygen species (ROS) and glutathione (GSH) were also evaluated. Results: In primary microglia, acetate decreased LPS-stimulated NO production in a dose-dependent manner, reaching significance at greater than 10 mM, and cell viability was not affected. Acetate suppressed LPS-induced expression of iNOS protein concomitantly with the decrease in NO. The LPS-induced increase in intracellular ROS production was attenuated by acetate. In addition, acetate prevented LPSinduced reduction of GSH. Notably, such suppressive effects of acetate on NO and ROS production were not observed in BV-2 cells. Conclusion: These findings suggest that acetate may alleviate neuroinflammatory responses by attenuating NO and ROS production in primary microglia but not in BV-2 cells. Other: All animals received humane care and the animal protocols used in this study were approved by the Ethics Committees for Animal Experimentation.

1997 ◽  
Vol 273 (6) ◽  
pp. C1882-C1888 ◽  
Author(s):  
Sharma S. Prabhakar ◽  
Guillermo A. Zeballos ◽  
Martin Montoya-Zavala ◽  
Claire Leonard

Macrophage dysfunction is considered an important contributory factor for increased propensity of infections in uremia. Because nitric oxide (NO) is believed to be an effector molecule of macrophage cytotoxicity, we propose that the dysfunction may be related to impaired NO synthesis. To verify this hypothesis, we evaluated macrophage NO synthesis in the presence of urea, a compound that accumulates in renal failure and is believed by some to be a uremic toxin. Macrophages (RAW 264.7 cells) were incubated with bacterial lipopolysaccharide to induce NO synthesis, whereas the test groups had various concentrations of urea in addition. NO synthesis was measured by assaying the supernatant for nitrites and nitrates by chemiluminescence. We observed that urea consistently produced a dose-dependent reversible inhibition of inducible NO production in macrophages, whereas parathormone, another toxin retained in uremia, had no such inhibitory effects. Further studies revealed that mRNA for inducible NO synthase was not inhibited by urea. We thus conclude that urea inhibits inducible NO synthesis in macrophages by a posttranscriptional mechanism and that this may be important in macrophage dysfunction of uremia.


2005 ◽  
Vol 33 (03) ◽  
pp. 415-424 ◽  
Author(s):  
Eunkyue Park ◽  
Susan Kum ◽  
Chuanhua Wang ◽  
Seung Yong Park ◽  
Bo Sook Kim ◽  
...  

Houttuynia cordata Thunb. (HC), Glycyrrhiza uralensis Fischer (GU), Forsythia suspense (Thunb.) Vahl (FS), and Lonicera japonica Thunb. (LJ) are Chinese herbs known to possess anti-inflammatory properties. The effects of aqueous extracts of these herbs on the production of the pro-inflammatory mediators, nitric oxide (NO) and tumor necrosis factor-alpha (TNF-α) were examined in an activated macrophage-like cell line, RAW 264.7 cells. Aqueous extracts from FS at 0.0625–2.0 mg/ml inhibited in vitro production of NO and secretion of TNF-α in a dose-dependent manner. FS at 1.0–2.0 mg/ml and 0.125–2.0 mg/ml significantly inhibited NO production and TNF-α, respectively. An extract of LJ demonstrated potent inhibition of both NO production and TNF-α secretion in a dose-dependent manner. An aqueous extract from HC inhibited NO production in a dose-dependent manner, but minimally (approximately 30%) inhibited TNF-α secretion at 0.0625 and 0.125 mg/ml. In contrast, an aqueous extract of GU had a minimal effect on both the production of NO and the secretion of TNF-α. Viability of cells at all concentrations studied was unaffected as determined by MTT cytotoxicity assay and trypan blue dye exclusion. These results suggest that aqueous extracts from FS, LJ and HC have anti-inflammatory actions as measured by inhibition of NO production and/or TNF-α secretion.


Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 257
Author(s):  
Seong Su Hong ◽  
Ji Eun Lee ◽  
Yeon Woo Jung ◽  
Ju-Hyoung Park ◽  
Jung A. Lee ◽  
...  

In our search for novel plant-derived inhibitors of nitric oxide (NO) with potential for treating inflammatory diseases, the phytochemicals of Amomum tsao-ko fruits were investigated, leading to the isolation of one bicyclic nonane (1), three menthene skeleton monoterpenoids (2–4), and two acyclic monoterpenoids (5 and 6). Their structures were identified using one- and two-dimensional nuclear magnetic resonance spectroscopy, and mass spectrometry. To the best of our knowledge, compounds 2–5 were obtained from the genus Amomum for the first time. All isolates were tested for their ability to inhibit lipopolysaccharide-stimulated NO overproduction in RAW264.7 cells. Compound 4 was found to inhibit NO production. Western blotting analysis indicated that active compound 4 can regulate inducible NO synthase expression. In addition, lipopolysaccharide-induced interleukin 1 beta and interleukin-6 overproduction was reduced in a concentration-dependent manner.


2020 ◽  
Author(s):  
Zhengmeng Yang ◽  
Lu Feng ◽  
Xiaoting Zhang ◽  
Weiping Lin ◽  
Bin Wang ◽  
...  

Abstract Background: Natural small molecules have become more attractive as alternatives to non-steroidal anti-inflammatory drugs in osteoarthritis (OA) treatments. This study aims to investigate the effects of Asiatic acid (AA) on OA in chondrocytes and the surgery-induced OA animal model. Methods: Cytotoxicity of AA in primary rat articular chondrocytes was determined. Chondrocytes were pretreated with AA at the safe concentrations and subsequently treated with IL-1β. The production of inflammatory mediators including nitric oxide (NO), nitric oxide synthase (iNOS), as well as cyclooxygenase (COX)-2, and the expression of chondrogenic and hypertrophic markers including Sox 9, Aggrecan, Col 2a1, and matrix metalloproteinase-13 (MMP13) in the cells were measured. The effect of AA on nuclear factor-kappa B (NF-κB) signaling pathway was further determined by dual luciferase assay and western blot. The surgery-induced OA animals were treated with AA or saline for 6 weeks. The pathological changes in the affected joints were measured by micro-CT and histological analysis. Results: We found a broad safety spectrum of AA from 0 to 25 μM. A dose-dependent inhibitory effect of AA on NO production, as well as iNOS and COX-2 expression were found. Meanwhile, AA promoted chondrogenesis and inhibited hypertrophy in chondrocyte treated with IL-1β. In addition, AA inhibited NF-κB signaling pathway with a dose-dependent manner. Furthermore, results from animal study revealed that AA prevented articular cartilage damage as well as subchondral bone remodeling in the surgery-induced OA animal.


2000 ◽  
Vol 74 (8) ◽  
pp. 3605-3612 ◽  
Author(s):  
Zheng Xing ◽  
Karel A. Schat

ABSTRACT The replication of Marek's disease herpesvirus (MDV) and herpesvirus of turkeys (HVT) in chicken embryo fibroblast (CEF) cultures was inhibited by the addition ofS-nitroso-N-acetylpenicillamine, a nitric oxide (NO)-generating compound, in a dose-dependent manner. Treatment of CEF culture, prepared from 11-day-old embryos, with recombinant chicken gamma interferon (rChIFN-γ) and lipopolysaccharide (LPS) resulted in production of NO which was suppressed by the addition ofN G-monomethyl l-arginine (NMMA), an inhibitor of inducible NO synthase (iNOS). Incubation of CEF cultures for 72 h prior to treatment with rChIFN-γ plus LPS was required for optimal NO production. Significant differences in NO production were observed in CEF derived from MDV-resistant N2a (major histocompatibility complex [MHC],B 21 B 21) and MDV-susceptible S13 (MHC,B 13 B 13) and P2a (MHC,B 19 B 19) chickens. N2a-derived CEF produced NO earlier and at higher levels than CEF from the other two lines. The lowest production of NO was detected in P2a-derived CEF. NO production in chicken splenocyte cultures followed a similar pattern, with the highest levels of NO produced in cultures from N2a chickens and the lowest levels produced in cultures from P2a chickens. Replication of MDV and HVT was significantly inhibited in CEF cultures treated with rChIFN-γ plus LPS and producing NO. The addition of NMMA to CEF treated with rChIFN-γ plus LPS reduced the inhibition. MDV infection of chickens treated withS-methylisothiourea, an inhibitor of iNOS, resulted in increased virus load compared to nontreated chickens. These results suggest that NO may play an important role in control of MDV replication in vivo.


1998 ◽  
Vol 66 (5) ◽  
pp. 2115-2121 ◽  
Author(s):  
Mbithe Mutunga ◽  
Patricia M. Preston ◽  
Keith J. Sumption

ABSTRACT Nitric oxide (NO) is a labile inorganic free radical produced by NO synthase from the substrate l-arginine in various cells and tissues including endothelial cells. A substantial elevation of nitrite levels indicative of NO production occurred in cultures ofCowdria ruminantium-infected bovine pulmonary endothelial cells (BPEC) incubated in medium alone. Exposure of the infected cultures to recombinant bovine gamma interferon (BorIFN-γ) resulted in more rapid production of NO, reduced viability of C. ruminantium, and induction of endothelial cell death. Significant inhibition of NO production was noted after addition of the NO synthase inhibitor N-monomethyl-l-arginine (l-NMMA), indicating that the increase in production occurred via the inducible NO synthase pathway. Reduction in the infectivity of C. ruminantium elementary bodies (EBs) occurred in a dose-dependent manner after incubation with the NO donor moleculeS-nitroso-N-acetyl-dl-penicillamine (SNAP) prior to infection of endothelial cells. The level of infection in cultures maintained in SNAP was reduced in a dose-dependent manner with significant negative correlation between the final level of infection on day 7 and the level of SNAP (r = −0.96). It was established that pretreatment and cultivation of C. ruminantium EBs with the NO donor molecule SNAP reduced infectivity to cultures and viability of EBs with the implication that release of NO in vivo following infection of endothelial cells may have an effect upon the multiplication of the agent in the host animal and may be involved in the pathogenesis of heartwater through the effect of this molecule upon circulation.


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Mitsuaki Moriyama ◽  
Ayano Hashimoto ◽  
Hideyo Satoh ◽  
Kenji Kawabe ◽  
Mizue Ogawa ◽  
...  

Cumulative evidence indicates that estrogen receptor (ER) agonists attenuate neuroinflammation. Equol, a major isoflavone from soybean, exhibits estrogen-like biological activity, but their effect on inflammatory response has not been well established. Here, we investigated the effect of S-equol on nitric oxide (NO) production, well-known inflammatory change in astrocytes stimulated by LPS. S-Equol attenuated LPS-induced NO production with a concomitant decrease in expression of inducible NO synthase (iNOS). S-Equol did not affect LPS-induced increase in intracellular ROS production. Intracellular ER blocker ICI 182.780 had no effect on S-equol-induced decrease in NO production. Addition of G-15, antagonist of G protein-coupled receptor 30 which is nongenomic ER and located on cell surface, partially recovered S-equol-induced attenuation of NO production. These findings suggest that attenuation of NO production by S-equol may mitigate LPS-induced neuroinflammation in astrocytes. S-Equol may exert a glioprotective effect, at least in part, via a nongenomic effect.


2014 ◽  
Vol 25 (3-4) ◽  
pp. 24-33
Author(s):  
O. I. Dzjuba ◽  
M. V. Yatsenko

The article deals with the history of the study and the current state of research of physiological and biochemical properties of the plant genus Sedum that are useful for human and has been used in folk medicine for many years. It was noticed that antioxidant properties of extracts from plants S. sarmentosum, S. sempervivoides, S. takesimense were caused by the presence of phenolic compounds. Methanol extract of plants S. takesimense exhibited strong scavenging activities against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radicals as well as significant inhibitory effects on lipid peroxidation and low density lipoprotein (LDL) oxidation induced by a metal ion Cu2+. Various immunomodulatory activities of various fractions of plants extracts (S. dendroideum, S. kamtschaticum, S. sarmentosum, S. telephium) are observed. It was shown that the ethanol extract of S. sarmentosum and it’s fractions suppressed specific antibody and cellular responses to ovalbumin in mice. The methanol extract of plants S. sarmentosum reduced the levels of anti-inflammatory markers, such as volume of exudates, number of polymorphonuclear leukocytes, suppressed nitric oxide synthesis in activated macrophages via suppressed induction of inducible nitric oxide synthase (iNOS). Polysaccharides fractions from plants S. telephium inducing productions of tumor necrosis factor alpha (TNF-α), increasing the intensity of phagocytosis in vitro and in vivo. Methanol extract from the whole part of S. kamtschaticum strongly inhibit PGE2 production from lipopolysaccharide-induced RAW 264.7 cells, a mouse macrophage cell line via modulating activity in gene expression of the enzyme cyclooxygenase-2 (COX-2). The methanol extract of plants S. sarmentosum and the major kaempferol glycosides from S. dendroideum have antinociceptive activity. It was noticed that anti-adipogenic activity of extracts from plants S. kamtschaticum were caused by inhibition of peroxisome-proliferator-activated receptor γ (PPARγ) expression and it’s dependent target genes, such as genes encoding adipocyte protein 2 (аР2), lipoprotein lipase (LPL), adiponectin and CD36. Polysaccharides fractions from S. telephium cause inhibition of cell adhesion of human fibroblast (MRC5) to laminin and fibronectin via interfere with integrin-mediated cell behaviour and they contributed to the role of polysaccharides in cell-matrix interaction. The methanol extract of plants S. sarmentosum exhibited a significant inhibitory activity in the chick embryo chorioallantoic membrane angiogenesis in a dose-dependent manner. The crude alkaloid fraction of S. sarmentosum caused a dose-dependent inhibition of cell proliferation on murine hepatoma cell line BNL CL.2 and human hepatoma cell line HepG2 without necrosis or apoptosis. Alkaloids from plants S. sarmentosum may improve survival of hepatoma patients via the inhibition of excessive growth of tumor cells. Plant’s juices have antiviral activity (S. sarmentosum, S. spurium, S. stahlii). Crude ethanol extract S. praealtum have spermicidal activity of the in mice and a relevant inhibitory effect of aqueous extract on human spermatozoa motility as well as an anti-fertilizing activity in rats. Hepatoprotective triterpenes, e.g., δ-amyrone, 3-epi-δ-amyrin, δ-amyrin and sarmentolin were isolated from S. sarmentosum. 2- and 2,6-substituted piperidine alkaloids (e.g., norsedamine, allosedridine, sedamine, allosedamine) are observed in plants S. acre, which in the presence of data on the use of pyridine and piperidine derivatives for treating neurodegenerative diseases (e.g., Alzheimer's disease), points on the promising research in this area. Taking into account that biologically active compounds are accumulated in the aboveground vegetative organs of plants of Sedum, the prospects of further study of the use of Sedum for the purposes of biotechnology and in the pharmaceutical industry becomes apparent. This work extends the existing views regarding the use of plants Sedum.


This trial research was performed to discuss the immune-influence of Melaleuca leucadendra ‘paper-bark tree’ dried leaves which is an important medical plant known in many regions in the world. The leaves were dissolved in a mixture of (ethanol + water) (3:1) mixture, then filtered, evaporated and dried under reduced pressure to obtain leaves extract. The macrophages of blood derived origin were provided from rats and mixed with three different leaves extracts doses in tissue culture plates and incubated then stained with fluorescent acridine orange and examined under fluorescent microscope to assess the phagocytic and killing potency. The wells contents were aspirated and assayed for nitric oxide and interleukin-2 levels. The results displayed an obvious increase in phagocytic, killing performance as well as nitric oxide and IL-2 level production than control in a dose dependent manner. The obtained results suggested the immune-stimulant impact of the paper-bark tree leaves.


2020 ◽  
Vol 85 (4) ◽  
pp. 882-889
Author(s):  
Yan Liang ◽  
Shijiao Zha ◽  
Masanobu Tentaku ◽  
Takasi Okimura ◽  
Zedong Jiang ◽  
...  

ABSTRACT In this study, we found that a sulfated polysaccharide isolated from the brown alga Ascophyllum nodosum, ascophyllan, showed suppressive effects on stimulated RAW264.7 cells. Ascophyllan significantly inhibited expression of inducible nitric oxide synthase mRNA and excessive production of nitric oxide (NO) in lipopolysaccharide (LPS)-stimulated RAW264.7 cells in a dose-dependent manner without affecting the viability of RAW264.7 cells. Ascophyllan also reduced the elevated level of intracellular reactive oxygen species (ROS) in LPS-stimulated RAW264.7 cells. Furthermore, preincubation with ascophyllan resulted in concentration-dependent decrease in ROS production in phorbol 12-myristate-13-acetate-stimulated RAW264.7 cells. Our results suggest that ascophyllan can exhibit anti-inflammatory effects on stimulated macrophages mainly through the attenuation of NO and ROS productions.


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