• BMB Reports
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• v.56 no.6
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• pp.359-364
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• 2023

KAI1/CD82, a membrane tetraspanin protein, can prevent various cancers and retinal disorders through its anti-angiogenic and anti-metastatic capacity. However, little is known about its anti-inflammatory effect and molecular mechanism. Therefore, the present study aimed to inLPSvestigate effect of a recombinant protein of the large extracellular domain of human KAI1 (Gly 111-Leu 228, rhKAI1) on lipopolysaccharides (LPS)-stimulated RAW264.7 macrophage-like cells and mouse bone marrow-derived macrophages (BMDM) and to identify its underlying mechanism. Our data showed that rhKAI1 suppressed expression levels of classically macrophages (M1) phenotype-related surface markers F4/80+CD86+ in LPS-stimulated BMDM and RAW264.7 cells. In addition, LPS markedly increased mRNA expression and release levels of pro-inflammatory cytokines and mediators such as interleukin (IL)-1β, IL-6, tumor necrosis factor-α, cyclooxygenase-2, nitric oxide and prostaglandin E2, whereas these increases were substantially down-regulated by rhKAI1. Furthermore, LPS strongly increased expression of NF-κB p65 in the nuclei and phosphorylation of ERK, JNK, and p38 MAPK. However, nuclear translocation of NF-κB p65 and phosphorylation of JNK were greatly reversed in the presence of rhKAI1. Especially, rhKAI1 markedly suppressed expression of toll-like receptor (TLR4) and prevented binding of LPS with TLR4 through molecular docking predict analysis. Importantly, Glu 214 of rhKAI1 residue strongly interacted with Lys 360 of TLR4 residue, with a binding distance of 2.9 Å. Taken together, these findings suggest that rhKAI1 has an anti-inflammatory effect on LPS-polarized macrophages by interacting with TLR4 and down-regulating the JNK/NF-κB signaling pathway.

• Journal of Microbiology and Biotechnology
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• v.33 no.5
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• pp.591-599
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• 2023

Fisetin is a bioactive flavonol molecule and has been shown to have antioxidant potential, but its efficacy has not been fully validated. The aim of the present study was to investigate the protective efficacy of fisetin on C2C12 murine myoblastjdusts under hydrogen peroxide (H₂O₂)-induced oxidative damage. The results revealed that fisetin significantly weakened H₂O₂-induced cell viability inhibition and DNA damage while blocking reactive oxygen species (ROS) generation. Fisetin also significantly alleviated cell cycle arrest by H₂O₂ treatment through by reversing the upregulation of p21WAF1/CIP1 expression and the downregulation of cyclin A and B levels. In addition, fisetin significantly blocked apoptosis induced by H₂O₂ through increasing the Bcl-2/Bax ratio and attenuating mitochondrial damage, which was accompanied by inactivation of caspase-3 and suppression of poly(ADP-ribose) polymerase cleavage. Furthermore, fisetin-induced nuclear translocation and phosphorylation of Nrf2 were related to the increased expression and activation of heme oxygenase-1 (HO-1) in H₂O₂-stimulated C2C12 myoblasts. However, the protective efficacy of fisetin on H₂O₂-mediated cytotoxicity, including cell cycle arrest, apoptosis and mitochondrial dysfunction, were greatly offset when HO-1 activity was artificially inhibited. Therefore, our results indicate that fisetin as an Nrf2 activator effectively abrogated oxidative stress-mediated damage in C2C12 myoblasts.

• Journal of Life Science
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• v.33 no.11
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• pp.859-867
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• 2023

Lupeol is a type of pentacyclic triterpene that has been reported to have therapeutic effects for treating many diseases; however, its effect on insulin resistance is unclear clear. This study examined the inhibitory effect of lupeol on the serine phosphorylation of insulin receptor substrate-1 in insulin resistance-induced 3T3-L1 adipocytes. 3T3-L1 cells were cultured and treated with tumor necrosis factor-α (TNF-α) for 24 hours to induce insulin resistance. Cells treated with different concentrations of lupeol (15 μM or 30 μM) or 100 nM of rosiglitazone were incubated. Then, lysed cells underwent western blotting. Lupeol exhibited a positive effect on the negative regulator of insulin signaling and inflammation-activated protein kinase caused by TNF-α in adipocytes. Lupeol inhibited the activation of protein tyrosine phosphatase-1B (PTP-1B)-a negative regulator of insulin signaling-and c-Jun N-terminal kinase (JNK); it was also an inhibitor of nuclear factor kappa-B kinase (IKK) and inflammation-activated protein kinases. In addition, Lupeol downregulated serine phosphorylation and upregulated tyrosine phosphorylation in insulin receptor substrate-1. Then, the downregulated phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway was activated, the translocation of glucose transporter type 4 was stimulated to the cell membrane, and intracellular glucose uptake increased in the insulin resistance-induced 3T3-L1 adipocytes. Lupeol may improve TNF-α-induced insulin resistance by downregulating the serine phosphorylation of insulin receptor substrate 1 by inhibiting negative regulators of insulin signaling and inflammation-activated protein kinases in 3T3-L1 adipocytes.

• Journal of Life Science
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• v.26 no.1
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• pp.50-58
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• 2016

The root bark of Ulmus macrocarpa has been used in traditional medicine for the treatment of various diseases such as edema, infection and inflammation. Nevertheless, the biological activities and underlying mechanisms of the immunomodulatory effects remain unclear. In this study, as part of our ongoing screening program to evaluate the immunomodulatory potential of new compounds from traditional medicinal resources, we investigated the effects of U. macrocarpa water extract (UME) on immune modulation in a murine RAW 264.7 macrophage model. As immune response parameters, the productions of as nitric oxide (NO) and cytokines such tumor necrotic factor (TNF)-α, interleukin (IL)-1β and IL-10 were evaluated. Although the release of IL-1β remained unchanged in UME-treated RAW 264.7 macrophages, the productions of NO, TNF-α and IL-10 were significantly increased, along with the increased expression of inducible NO synthase, TNF-α and IL-10 expression at concentrations with no cytotoxicity. UME treatment also induced the nuclear translocation of nuclear factor κB (NF-κB), and phosphorylation of Akt and mitogen-activated protein kinases (MAPKs) indicating that UME activated macrophages through the activation of NF-κB, phosphoinositide-3-kinase (PI3K)/Akt and MAPKs signaling pathways in RAW 264.7 macrophages. Furthermore, pre-treatment with UME significantly attenuated the production of NO, but not TNF-α, IL-1β and IL-10, in lipopolysaccharide-stimulated RAW 264.7 cells suggesting that UME may be useful in preventing inflammatory diseases mediated by excessive production of NO. These findings suggest that the beneficial therapeutic effects of UME may be attributed partly to its ability to modulate immune functions in macrophages.

• Food Science and Preservation
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• v.22 no.5
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• pp.735-743
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• 2015

This study investigated the anti-inflammatory activity of barley leaf extract in lipopolysaccharide (LPS)-stimulated RAW264.7 cells and hairless mice. Pre-treatment with barley leaf extract significantly inhibited the protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-II (COX-II) in a dose-dependent manner in LPS-stimulated RAW264.7 cells. Barley leaf extract also significantly inhibited the secretion of inflammatory cytokines, such as tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), interleukin-$1{\beta}$ (IL-$1{\beta}$), and interleukin-6 (IL-6). Moreover, phosphorylation of mitogen-activated protein kinases (MAPKs) and nuclear translocation of nuclear factor-kappa B (NF-${\kappa}B$) were strongly suppressed by barley leaf extract in LPS-stimulated cells. In hairless mice, barley extract significantly decreased the pathological phenotypes of contact dermatitis, such as erythema, edema, and scabs. These results indicate that barley leaf extract has an anti-inflammatory effect and therefore a possible role in the treatment of inflammatory diseases or in functional cosmetics.

• Journal of Mushroom
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• v.19 no.3
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• pp.225-233
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• 2021

In this study, we evaluated the anti-inflammatory effect of extract from Cudrania tricuspidata twig sawdust fermented with Ganoderma lucidum mycelium. Fermented Cudrania tricuspidata twig sawdust extracted with 70% ethanol and elucidated the potential signaling pathway in lipopolysaccharide (LPS)-induced RAW264.7 cells. Fermented Cudrania tricuspidata twig sawdust inhibits LPS-stimulated nitric oxide (NO) production without affecting cell viability in a dose-dependent manner and production of LPS-induced pro-inflammatory cytokines such as interleukin (IL)-1β, tumor necrosis factor (TNF)-α and prostaglandin2 (PGE₂). Fermented Cudrania tricuspidata twig sawdust also suppressed the expression of the pro-inflammatory mediators such as inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in LPS-stimulated RAW264.7 cells. Moreover, Fermented Cudrania tricuspidata twig sawdust significantly attenuated LPS-induced IkappaB (IκB) degradation and suppressed nuclear factor kappa B (NF-κB) nuclear translocation. These results suggest that fermented Cudrania tricuspidata twig sawdust may have great potential for the development of anti-inflammatory agent.

• Journal of Life Science
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• v.31 no.9
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• pp.818-826
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• 2021

5-Aminolevulinic acid phosphate (5-ALA-p) is a substance obtained by eluting 5-ALA (a natural delta amino acid) with aqueous ammonia, adding phosphoric acid to the eluate, and then adding acetone to confer properties suitable for use in photodynamic therapy applications. However, its pharmacological efficacy, including potential mechanisms of antioxidant and anti-inflammatory reactions, remains unclear. This study aimed to investigate the effects of 5-ALA-p on oxidative and inflammatory stresses in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Our data showed that 5-ALA-p significantly inhibited excessive phagocytic activity via LPS and attenuated oxidative stress in LPS-treated RAW 264.7 cells. Furthermore, 5-ALA-p improved mitochondrial biogenesis reduced by LPS, suggesting that 5-ALA-p restores mitochondrial damage caused by LPS. Additionally, 5-ALA-p significantly suppressed the release of nitric oxide (NO) and pro-inflammatory cytokines, such as tumor necrosis factor α (TNF-α), interleukin (IL)-1β, and IL-6, which are associated with the inhibition of inducible NO synthase and respective cytokine expression. Furthermore, 5-ALA-p reduced the nuclear translocation of nuclear factor-kappa B (NF-κB) and inhibited phosphorylation of mitogen-activated protein kinases (MAPKs), indicating that the anti-inflammatory effect of 5-ALA-p is mediated through the suppression of NF-κB and MAPK signaling pathways. Based on these results, 5-ALA-p may serve as a potential candidate to reduce inflammation and oxidative stress.

• Journal of Life Science
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• v.28 no.11
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• pp.1361-1368
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• 2018

Inflammation is the most common condition in the human body. Tissue damage triggers inflammation, together with vasodilation and increased blood flow at the inflamed site, resulting in edema. Inflammatory responses are also triggered by lipopolysaccharide (LPS), a Toll-like receptor Enterococcus faecalis, a gram-positive organism, has been reported to possess immunomodulatory and preventive activities; however, its use may present risks of sepsis and other systemic infections. Heat-killed Enterococcus faecalis (EF-2001) has been reported to induce antitumor activity, but its effects on inflammation are not known. In the present study, we investigated the effect of EF-2001 on LPS-induced macrophage inflammatory responses. EF-2001 treatment reduced nitric oxide (NO) production, indicating suppression of inflammatory reactions. EF-2001 showed no cytotoxicity in macrophages. Further investigation of the anti-inflammatory mechanism of EF-2001 indicated that EF-2001 reduced the LPS-induced expression of inducible nitric oxide synthase and cyclooxygenase-2. EF-2001 also reduced f the LPS induction of several inflammatory molecules involved in the nuclear factor-${\kappa}B$ ($NF-{\kappa}B$) and mitogen-activated protein kinase pathways, including ERK, JNK, and p38 phosphorylation, in a concentration-dependent manner. Additionally, EF-2001 inhibited Akt phosphorylation and increased the expression of the inhibitory ${\kappa}B$ ($I{\kappa}B$) protein, an inhibitor of $NF-{\kappa}B$. EF-2001 also inhibited the nuclear translocation of p65. These results suggest that EF-2001 has anti-inflammatory properties and may be useful for treating inflammatory diseases.

• Journal of Life Science
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• v.29 no.4
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• pp.484-491
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• 2019

Proanthocyanidins are naturally occurring polyphenolic compounds abundant in many vegetables, plant skins (rind/bark), seeds, flowers, fruits, and nuts. Numerous in vitro and in vivo studies have demonstrated myriad effects potentially beneficial to human health, such as antioxidation, immunomodulation, DNA repair, and antitumor activity. Among immune cells, macrophages are crucial players in a variety of inflammatory responses to environmental conditions. However, it has been widely reported that macrophages cause chronic inflammation and are involved in a variety of diseases, such as obesity, diabetes, metabolic syndrome, and cancer. In this study, we report the suppressive effect of proanthocyanidins via the heme oxygenase-1 (HO-1)-related system, on the immune response of the LPS-stimulated mouse macrophage cell line RAW264.7. Increased HO-1 expression at mRNA and protein levels were found in proanthocyanidins-treated RAW264.7 cells. Further, proanthocyanidins enhanced nuclear factor-erythroid 2-related factor 2 translocation into the nucleus. RAW264.7 cells were treated with lipopolysaccharide (LPS) with or without proanthocyanidins, and inflammatory mediator expression levels were assessed. Proanthocyanidins treatment resulted in the attenuation of nitric oxide production and inducible nitric oxide synthase expression in LPS-stimulated RAW264.7 cells. In addition, mRNA and protein expression of proinflammatory cytokines, such as tumor necrosis factor-${\alpha}$ and interleukin-6, was inhibited by proanthocyanidins treatment in LPS-stimulated RAW264.7 cells. These findings support proanthocyanidins as a promising anti-inflammatory agent.

• Journal of Nutrition and Health
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• v.51 no.6
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• pp.507-514
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• 2018

Purpose: Sargassum horneri (S. horneri) is a species of brown macroalgae that is common along the coast of Japan and Korea. The present study investigated the immuno-modulatory effects of different types of S. horneri extracts in RAW264.7 macrophages. Methods: S. horneri was extracted by three different methods, hot water extraction, 50% ethanol extraction, and supercritical fluid extraction. Cell viability was then measured by MTT assay, while the production levels of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), interleukin-6 (IL-6), and nitric oxide (NO) were measured by enzyme-linked immunosorbent assay and Griess assay, respectively. The expression and activation levels of inducible NO synthase (iNOS), mitogen-activated protein kinase (MAPK) and nuclear factor ${\kappa}B$ ($NF-{\kappa}B$) were examined by western blot analysis. Results: The three different S. horneri extracts were nontoxic against RAW 264.7 cells up to $50{\mu}g/mL$, among which treatment with hot water extract (HWE) of S. horneri significantly enhanced the production of TNF-${\alpha}$, IL-6, and NO in a dose-dependent manner. Hot water extract of S. horneri also increased the expression level of iNOS, suggesting that up-regulation of iNOS expression by HWE of S. horneri was responsible for the induction of NO production. In addition, treatment of RAW 264.7 macrophages with HWE of S. horneri increased the phosphorylation levels of ERK, p38 and JNK. Furthermore, the activation and subsequent nuclear translocation of $NF-{\kappa}B$ was enhanced upon treatment with HWE of S. horneri, indicating that HWE of S. horneri activates macrophages to secrete TNF-${\alpha}$, IL-6 and NO and induces iNOS expression via activation of the $NF-{\kappa}B$ and MAPKs signaling pathways. Conclusion: Taken together, these findings suggest that HWE of S. horneri possesses potential as a functional food with immunomodulatory activity.