Synthesis of Biotin-Tagged Chitosan Oligosaccharides and Assessment of Their Immunomodulatory Activity

Chitin, a polymer of β-(1→4)-linked N-acetyl-d-glucosamine, is one of the main polysaccharide components of the fungal cell wall. Its N-deacetylated form, chitosan, is enzymatically produced in the cell wall by chitin deacetylases. It exerts immunomodulative, anti-inflammatory, anti-cancer, anti-bacterial, and anti-fungal activities with various medical applications. To study the immunobiological properties of chitosan oligosaccharides, we synthesized a series of β-(1→4)-linked N-acetyl-d-glucosamine oligomers comprising 3, 5, and 7 monosaccharide units equipped with biotin tags. The key synthetic intermediate employed for oligosaccharide chain elongation, a disaccharide thioglycoside, was prepared by orthogonal glycosylation of a 4-OH thioglycoside acceptor with a glycosyl trichloroacetimidate bearing the temporary 4-O-tert-butyldimethylsilyl group. The use of silyl protection suppressed aglycon transfer and provided a high yield for the target disaccharide donor. Using synthesized chitosan oligomers, as well as previously obtained chitin counterparts, the immunobiological relationship between these synthetic oligosaccharides and RAW 264.7 cells was studied in vitro. Evaluation of cell proliferation, phagocytosis, respiratory burst, and Th1, Th2, Th17, and Treg polarized cytokine expression demonstrated effective immune responsiveness and immunomodulation in RAW 264.7 cells exposed to chitin- and chitosan-derived oligosaccharides. Macrophage reactivity was accompanied by significant inductive dose- and structure-dependent protective Th1 and Th17 polarization, which was greater with exposure to chitosan- rather than chitin-derived oligosaccharides. Moreover, no antiproliferative or cytotoxic effects were observed, even following prolonged 48 h exposure. The obtained results demonstrate the potent immunobiological activity of these synthetically prepared chito-oligosaccharides.

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Spirulina maxima Derived Pectin Nanoparticles Enhance the Immunomodulation, Stress Tolerance, and Wound Healing in Zebrafish

Marine Drugs ◽

10.3390/md18110556 ◽

2020 ◽

Vol 18 (11) ◽

pp. 556

Author(s):

Dinusha C. Rajapaksha ◽

Shan L. Edirisinghe ◽

Chamilani Nikapitiya ◽

SHS Dananjaya ◽

Hyo-Jung Kwun ◽

...

Keyword(s):

Wound Healing ◽

Biological Effects ◽

Raw 264.7 Cells ◽

Control Group ◽

Immunomodulatory Activity ◽

Raw 264.7 ◽

Adult Zebrafish ◽

Spirulina Maxima ◽

In Vivo Models

In this study, Spirulina maxima derived pectin nanoparticles (SmPNPs) were synthesized and multiple biological effects were investigated using in vitro and in vivo models. SmPNPs were not toxic to Raw 264.7 cells and zebrafish embryos up to 1 mg/mL and 200 µg/mL, respectively. SmPNPs upregulated Il 10, Cat, Sod 2, Def 1, Def 2, and Muc 1 in Raw 264.7 cells and tlr2, tlr4b, tlr5b, il1β, tnfα, cxcl8a, cxcl18b, ccl34a.4, ccl34b.4, muc5.1, muc5.2, muc5.3, hamp, cstd, hsp70, cat, and sod1 in the larvae and adult zebrafish, suggesting immunomodulatory activity. Exposure of larvae to SmPNPs followed by challenge with pathogenic bacterium Aeromonas hydrophila resulted a two-fold reduction of reactive oxygen species, indicating reduced oxidative stress compared to that in the control group. The cumulative percent survival of larvae exposed to SmPNPs (50 µg/mL) and adults fed diet supplemented with SmPNPs (4%) was 53.3% and 76.7%, respectively. Topical application of SmPNPs on adult zebrafish showed a higher wound healing percentage (48.9%) compared to that in the vehicle treated group (38.8%). Upregulated wound healing markers (tgfβ1, timp2b, mmp9, tnfα, il1β,ccl34a.4, and ccl34b.4), enhanced wound closure, and restored pigmentation indicated wound healing properties of SmPNPs. Overall, results uncover the multiple bioactivities of SmPNPs, which could be a promising biocompatible candidate for broad range of aquatic and human therapies.

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Physicochemical Characterization of Polysaccharides with Macrophage Immunomodulatory Activities Isolated from Red Ginseng (Panax ginseng C. A. Meyer)

Journal of Chemistry ◽

10.1155/2017/3276430 ◽

2017 ◽

Vol 2017 ◽

pp. 1-8 ◽

Cited By ~ 2

Author(s):

Liang Zheng ◽

Mengyue Wang ◽

Ying Peng ◽

Xiaobo Li

Keyword(s):

Physicochemical Characterization ◽

Monosaccharide Composition ◽

Neutral Red ◽

Raw 264.7 Cells ◽

Immunomodulatory Activity ◽

No Production ◽

Raw 264.7 ◽

Red Ginseng ◽

Molecular Ratio

In this study, four polysaccharide fractions designated as RGP1, RGP2, RGP3, and RGP4 were isolated from red ginseng by DEAE-52 cellulose chromatography, and their macrophage immunomodulatory activities were investigated. The results revealed that the proliferation, NO production, and neutral red phagocytosis of RAW 264.7 macrophage cells in groups treated with RGP1 and RGP2 in vitro were increased significantly compared to RGP3 and RGP4. In addition, the level of TNF-α in RAW 264.7 cells was significantly increased in RGP1 and RGP2 groups. All the results consistently indicated that polysaccharide fractions RGP1 and RGP2 had strong macrophage immunomodulatory activities. Furthermore, RGP1 and RGP2 were purified by Sephadex G-100 column and RGP2 was further fractionated into a homogeneous fraction RGP2-1, with the molecular weight of 2.16 × 104 Da. The analysis of monosaccharide composition revealed that RGP1 was composed of arabinose, glucose, and galactose with a relative molecular ratio of 0.02 : 0.88 : 0.10. RGP2-1 was composed of rhamnose, arabinose, glucose, and galactose with a relative molecular ratio of 0.02 : 0.10 : 0.77 : 0.11. These results provided evidences that the neutral polysaccharide fractions RGP1 and RGP2 possessed significant immunomodulatory activity and could be explored as a promising natural immunomodulating agent applied in functional foods or medicines.

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Unveiling the Properties of Thai Stingless Bee Propolis via Diminishing Cell Wall-Associated Cryptococcal Melanin and Enhancing the Fungicidal Activity of Macrophages

Antibiotics ◽

10.3390/antibiotics9070420 ◽

2020 ◽

Vol 9 (7) ◽

pp. 420

Author(s):

Ketsaya Mamoon ◽

Patcharin Thammasit ◽

Anupon Iadnut ◽

Kuntida Kitidee ◽

Usanee Anukool ◽

...

Keyword(s):

Cell Wall ◽

Complex Structure ◽

Ethanolic Extract ◽

Stingless Bee ◽

Immunomodulatory Activity ◽

Raw 264.7 ◽

Dependent Manner ◽

Yeast Infection ◽

Chitin And Chitosan ◽

Dose Dependent

Cryptococcus neoformans, a life-threatening human yeast pathogen, has the ability to produce melanin, which is one of the common virulence factors contributing to cryptococcal pathogenesis. This virulence factor is closely associated with the cryptococcal cell wall, specifically chitin and chitosan polysaccharides, a complex structure that is essential for maintaining cellular structure and integrity. In this study, we aim to investigate the effects of two stingless bee (SLB) propolis from Tetragonula laeviceps and Tetrigona melanoleuca against cell wall-associated melanin in C. neoformans, and its immune response in RAW 264.7 macrophage. The ethanolic extract of SLB propolis (EEP) has strongly exhibited anti-cryptococcal activity. Moreover, EEP from both sources reduced chitin/chitosan and melanin production against C. neoformans in a dose-dependent manner. Likewise, the mRNA expression level of CDA1, IPC1-PKC1 and LAC1 genes involved in the cryptococcal melanization pathway was significantly decreased at 2 mg/mL in EEP treatment. Additionally, pretreatment with EEP prior to yeast infection dramatically reduced intracellular replication of C. neoformans in RAW 264.7 macrophages in a dose-dependent manner. This study might be a new insight to use a natural powerful source, not only acting to target cell wall-associated molecules, but also being capable to explore a novel strategy by which dysregulation of these molecules leads to promote immunomodulatory activity.

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Phaseolin Attenuates Lipopolysaccharide-Induced Inflammation in RAW 264.7 Cells and Zebrafish

Biomedicines ◽

10.3390/biomedicines9040420 ◽

2021 ◽

Vol 9 (4) ◽

pp. 420

Author(s):

Su-Jung Hwang ◽

Ye-Seul Song ◽

Hyo-Jong Lee

Keyword(s):

Nitric Oxide ◽

Nuclear Translocation ◽

Raw 264.7 Cells ◽

Network Pharmacology ◽

Raw 264.7 ◽

Dependent Manner ◽

Bioactive Constituents

Kushen (Radix Sophorae flavescentis) is used to treat ulcerative colitis, tumors, and pruritus. Recently, phaseolin, formononetin, matrine, luteolin, and quercetin, through a network pharmacology approach, were tentatively identified as five bioactive constituents responsible for the anti-inflammatory effects of S. flavescentis. However, the role of phaseolin (one of the primary components of S. flavescentis) in the direct regulation of inflammation and inflammatory processes is not well known. In this study, the beneficial role of phaseolin against inflammation was explored in lipopolysaccharide (LPS)-induced inflammation models of RAW 264.7 macrophages and zebrafish larvae. Phaseolin inhibited LPS-mediated production of nitric oxide (NO) and the expression of inducible nitric oxide synthase (iNOS), without affecting cell viability. In addition, phaseolin suppressed pro-inflammatory mediators such as cyclooxygenase 2 (COX-2), interleukin-1β (IL-1β), tumor necrosis factor α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), and interleukin-6 (IL-6) in a dose-dependent manner. Furthermore, phaseolin reduced matrix metalloproteinase (MMP) activity as well as macrophage adhesion in vitro and the recruitment of leukocytes in vivo by downregulating Ninjurin 1 (Ninj1), an adhesion molecule. Finally, phaseolin inhibited the nuclear translocation of nuclear factor-kappa B (NF-κB). In view of the above, our results suggest that phaseolin could be a potential therapeutic candidate for the management of inflammation.

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A New Flavonol From Saussurea involucrata With Anti-Inflammatory Activity

Natural Product Communications ◽

10.1177/1934578x211007638 ◽

2021 ◽

Vol 16 (5) ◽

pp. 1934578X2110076

Author(s):

Sheng Pan ◽

Zi-Guan Zhu

Keyword(s):

Nitric Oxide ◽

Aerial Part ◽

Raw 264.7 Cells ◽

Raw 264.7 ◽

Spectroscopic Methods ◽

Soluble Extract ◽

Saussurea Involucrata ◽

Tnf Α ◽

Anti Inflammatory

A new flavonol named 6-(2'',3''-epoxy-3''-methylbutyl)-resokaempferol (1), together with five known compounds (2-6) were isolated from the EtOAc-soluble extract of the aerial part of Saussurea involucrata. Their structures were elucidated on the basis of spectroscopic methods. All compounds were evaluated for their anti-inflammatory effects by measuring the production of nitric oxide (NO) and TNF-α in vitro. Among them, compound 1 showed potential inhibitory activity on the production of NO and TNF-α in LPS-induced RAW 264.7 cells with IC50 values of 48.0 ± 1.5 and 41.4 ± 1.7 µM, respectively.

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Synthesis and anti-inflammatory activity of novel steroidal chalcones with 3β-pregnenolone ester derivatives in RAW 264.7 cells in vitro

Steroids ◽

10.1016/j.steroids.2021.108830 ◽

2021 ◽

pp. 108830

Author(s):

Xiaorui Cai ◽

Fei Sha ◽

Chuanyi Zhao ◽

Zhiwei Zheng ◽

Shulin Zhao ◽

...

Keyword(s):

Inflammatory Activity ◽

Raw 264.7 Cells ◽

Raw 264.7 ◽

Anti Inflammatory

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Inhibition of MAPK and STAT3-SOCS3 by Sakuranetin Attenuated Chronic Allergic Airway Inflammation in Mice

Mediators of Inflammation ◽

10.1155/2019/1356356 ◽

2019 ◽

Vol 2019 ◽

pp. 1-14 ◽

Cited By ~ 4

Author(s):

Fernanda P. R. Santana ◽

Rafael C. da Silva ◽

Simone dos S. Grecco ◽

Aruanã J. M. C. R. Pinheiro ◽

Luciana C. Caperuto ◽

...

Keyword(s):

Airway Inflammation ◽

Intracellular Signaling ◽

Lung Inflammation ◽

Serum Antibody ◽

Allergic Airway Disease ◽

Raw 264.7 Cells ◽

Raw 264.7 ◽

Mucus Production ◽

Th17 Cytokines

Asthma allergic disease is caused by airway chronic inflammation. Some intracellular signaling pathways, such as MAPK and STAT3-SOCS3, are involved in the control of airway inflammation in asthma. The flavonoid sakuranetin demonstrated an anti-inflammatory effect in different asthma models. Our aim was to clarify how sakuranetin treatment affects MAPK and STAT3-SOCS3 pathways in a murine experimental asthma model. Mice were submitted to an asthma ovalbumin-induction protocol and were treated with vehicle, sakuranetin, or dexamethasone. We assayed the inflammatory profile, mucus production, and serum antibody, STAT3-SOCS3, and MAPK levels in the lungs. Morphological alterations were also evaluated in the liver. LPS-stimulated RAW 264.7 cells were used to evaluate the effects of sakuranetin on nitric oxide (NO) and cytokine production. In vivo, sakuranetin treatment reduced serum IgE levels, lung inflammation (eosinophils, neutrophils, and Th2/Th17 cytokines), and respiratory epithelial mucus production in ovalbumin-sensitized animals. Considering possible mechanisms, sakuranetin inhibits the activation of ERK1/2, JNK, p38, and STAT3 in the lungs. No alterations were found in the liver for treated animals. Sakuranetin did not modify in vitro cell viability in RAW 264.7 and reduced NO release and gene expression of IL-1β and IL-6 induced by LPS in these cells. In conclusion, our data showed that the inhibitory effects of sakuranetin on eosinophilic lung inflammation can be due to the inhibition of Th2 and Th17 cytokines and the inhibition of MAPK and STAT3 pathways, reinforcing the idea that sakuranetin can be considered a relevant candidate for the treatment of inflammatory allergic airway disease.

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Trichilones A–E: New Limonoids from Trichilia adolfi

Molecules ◽

10.3390/molecules26113070 ◽

2021 ◽

Vol 26 (11) ◽

pp. 3070

Author(s):

Mariela Gonzalez-Ramirez ◽

Ivan Limachi ◽

Sophie Manner ◽

Juan C. Ticona ◽

Efrain Salamanca ◽

...

Keyword(s):

Mass Spectrometry ◽

Nmr Spectroscopy ◽

High Field ◽

Chemical Constituents ◽

Ethanol Extract ◽

Raw 264.7 Cells ◽

Raw 264.7 ◽

Murine Macrophage ◽

New Metabolites

In addition to the trichilianones A–D recently reported from Trichilia adolfi, a continuing investigation of the chemical constituents of the ethanol extract of the bark of this medicinal plant yielded the five new limonoids 1–5. They are characterized by having four fused rings and are new examples of prieurianin-type limonoids, having a ε-lactone which in 4 and 5 is α, β- unsaturated. The structures of the isolated metabolites were determined by high field NMR spectroscopy and HR mass spectrometry. The new metabolites were shown to have the ε-lactone fused with a tetrahydrofuran ring which is connected to an oxidized hexane ring joined with a cyclo-pentanone having a 3-furanyl substituent. As the crude extract possesses antileishmanial activity, the compounds were assayed for cytotoxic and antiparasitic activities in vitro in murine macrophage cells (raw 264.7 cells) and in Leishmania amazoniensis as well as L. braziliensis promastigotes. Metabolites 1–3 and 5 showed moderate cytotoxicity (between 30–94 µg/mL) but are not responsible for the antileishmanial effect of the extract.

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Febrile-range temperature modifies cytokine gene expression in LPS-stimulated macrophages by differentially modifying NF-κB recruitment to cytokine gene promoters

AJP Cell Physiology ◽

10.1152/ajpcell.00346.2009 ◽

2010 ◽

Vol 298 (1) ◽

pp. C171-C181 ◽

Cited By ~ 35

Author(s):

Zachary A. Cooper ◽

Arundhati Ghosh ◽

Aditi Gupta ◽

Tapan Maity ◽

Ivor J. Benjamin ◽

...

Keyword(s):

Gene Expression ◽

Receptor Activation ◽

Cytokine Gene Expression ◽

Raw 264.7 Cells ◽

Raw 264.7 ◽

Heat Shock Factor 1 ◽

Gene Promoters ◽

Cytokine Gene ◽

Tnf Α

We previously showed that exposure to febrile-range temperatures (FRT, 39.5–40°C) reduces LPS-induced TNF-α expression, in part through the direct interaction of heat shock factor-1 (HSF1) with the TNF-α gene promoter. However, it is not known whether exposure to FRT also modifies more proximal LPS-induced signaling events. Using HSF1-null mice, we confirmed that HSF1 is required for FRT-induced repression of TNF-α in vitro by LPS-stimulated bone marrow-derived macrophages and in vivo in mice challenged intratracheally with LPS. Exposing LPS-stimulated RAW 264.7 mouse macrophages to FRT reduced TNF-α expression while increasing IL-1β expression despite the two genes sharing a common myeloid differentiation protein-88 (MyD88)-dependent pathway. Global activation of the three LPS-induced signaling intermediates that lead to cytokine gene expression, ERK and p38 MAPKs and NF-κB, was not affected by exposing RAW 264.7 cells to FRT as assessed by ERK and p38 phosphorylation and NF-κB in vitro DNA-binding activity and activation of a NF-κB-dependent synthetic promoter. However, chromatin immunoprecipitation (ChIP) analysis demonstrated that exposure to FRT reduced LPS-induced recruitment of NF-κB p65 to the TNF-α promoter while simultaneously increasing its recruitment to the IL-1β promoter. These data suggest that FRT exerts its effects on cytokine gene expression in a gene-specific manner through distal effects on promoter activation rather than proximal receptor activation and signal transduction.

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Construction of a novel quinoxaline as a new class of Nrf2 activator

10.21203/rs.2.12921/v1 ◽

2019 ◽

Author(s):

Murugesh Kandasamy ◽

Kit-Kay Mak ◽

Thangaraj Devadoss ◽

Punniyakoti Veeraveedu Thanikachalam ◽

Raghavendra Sakirolla ◽

...

Keyword(s):

Docking Studies ◽

Metabolic Stability ◽

Raw 264.7 Cells ◽

Raw 264.7 ◽

New Class ◽

Ic50 Value ◽

Kelch Domain ◽

Anti Inflammatory ◽

Nrf2 Activator

Abstract The transcription factor Nuclear factor erythroid-2-related factor 2 (NRF2) and its principal repressive regulator, the E3 ligase adaptor Kelch-like ECH-associated protein 1 (KEAP1), are critical in the regulation of inflammation, as well as maintenance of homeostasis. Thus, NRF2 activation provides cytoprotection against numerous inflammatory disorders. N-nicotinoylquinoxaline-2-carbohdyrazide (NQC) was designed by combining the important pharmacophoric features of bioactive compounds reported in the literature. NQC was synthesised and characterised using spectroscopic techniques. The compound was tested for its anti-inflammatory effect using LPSEc induced inflammation in mouse macrophages (RAW 264.7 cells). The effect of NQC on inflammatory cytokines was measured using ELISA. The Nrf2 activity of the compound NQC was determined using ‘Keap1:Nrf2 Inhibitor Screening Assay Kit’. To obtain the insights on NQC’s activity on Nrf2, molecular docking studies were performed using Schrodinger suite. The metabolic stability of NQC was determined using mouse, rat and human microsomes. NQC was found to be non-toxic until the dose of 50 µM on RAW 264.7 cells. The NQC showed potent anti-inflammatory effect in an in vitro model of Lipopolysaccharide (LPS) stimulated murine macrophages (RAW 264.7 cells) with an IC50 value 26.13 ± 1.17 µM. The NQC dose-dependently down regulated the pro-inflammatory cytokines (Interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α) and inflammatory mediator, prostaglandin E2 (PGE2) with IC50 values 13.27 ± 2.37, 10.13 ± 0.58, 14.41 ± 1.83 and 15.23 ± 0.91 µM respectively. Molecular docking studies confirmed the favourable binding of NQC at Kelch domain of Keap-1. It disrupts the Nrf2 interaction with kelch domain of keap 1 and its IC50 value was 4.21 ± 0.89 µM. The metabolic stability studies of NQC in human, rat and mouse liver microsomes revealed that it is quite stable with half-life values; 59.78 ± 6.73, 52.93 ± 7.81, 28.43 ± 8.13 minutes; microsomal intrinsic clearance values; 22.1 ± 4.31, 26.0 ± 5.17 and 47.13 ± 6.34 µL/min/mg protein; respectively. So, rat has comparable metabolic profile with human, thus, rat could be used for predicting the pharmacokinetics and metabolism of NQC in human. NQC is a new class of NRF2 activator with potent in vitro anti-inflammatory activity and good metabolic stability.

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