• Journal of Periodontal and Implant Science
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• 제43권4호
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• pp.191-197
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• 2013

Purpose: Nitric oxide (NO) is a short-lived bioactive molecule that is known to play an important role in the pathogenesis of periodontal disease. In the current study, we investigated the effect of the flavonoid quercetin on the production of NO in murine macrophages activated with lipopolysaccharide (LPS) from Prevotella intermedia, a pathogen related to inflammatory periodontal disease, and tried to elucidate the underlying mechanisms of action. Methods: LPS was isolated from P. intermedia ATCC 25611 cells by the standard hot phenol-water method. The concentration of NO in cell culture supernatants was determined by measuring the accumulation of nitrite. Inducible NO synthase (iNOS) and heme oxygenase-1 (HO-1) protein expression, phosphorylation of c-Jun N-terminal kinase (JNK) and p38, inhibitory ${\kappa}B$ $(I{\kappa}B)-{\alpha}$ degradation, and signal transducer and activator of transcription 1 (STAT1) phosphorylation were analyzed via immunoblotting. Results: Quercetin significantly attenuated iNOS-derived NO production in RAW246.7 cells activated by P. intermedia LPS. In addition, quercetin induced HO-1 protein expression in cells activated with P. intermedia LPS. Tin protoporphyrin IX (SnPP), a competitive inhibitor of HO-1, abolished the inhibitory effect of quercetin on LPS-induced NO production. Quercetin did not affect the phosphorylation of JNK and p38 induced by P. intermedia LPS. The degradation of $I{\kappa}B-{\alpha}$ induced by P. intermedia LPS was inhibited when the cells were treated with quercetin. Quercetin also inhibited LPS-induced STAT1 signaling. Conclusions: Quercetin significantly inhibits iNOS-derived NO production in murine macrophages activated by P. intermedia LPS via anti-inflammatory HO-1 induction and inhibition of the nuclear factor-${\kappa}B$ and STAT1 signaling pathways. Our study suggests that quercetin may contribute to the modulation of host-destructive responses mediated by NO and appears to have potential as a novel therapeutic agent for treating inflammatory periodontal disease.

• Biomolecules & Therapeutics
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• 제9권3호
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• pp.194-200
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• 2001

Phellinus linteus (PL)-hot water extract (PL-W) or- methanol extract (PL-M) was orally administered alone (single dose of 400, 800, 1600 mg/kg; 800 mg/kg/day for 5 days) or with cyclophosphamide (CY, 20 mg/kg, i.p.) to female ICR mice. Within PL alone-treated group, WBC and plaque forming cells (PFC) to SRBC were slightly and significantly enhanced when compared with control group. The relative thymus and spleen weights, WBC and PFC numbers were significantly decreased by the treatment of CY, whereas those values were markedly increased by the concomitant treatment of CY and PL when compared with CY administration alone. To assess the effects of PL and/or CY on the mitogen response of splenocytes io LPS, mouse splenocytes were stimulated with or without LPS in the presence of various concentration of PL and/or CY in vitro and splenocytes proliferation (SP) was measured by MTT assay. PL alone increased both SP and LPS- stimulated SP. Moreover, SP and LPS-induced SP suppressed by the treatment of CY alone were significantly restored by PL-treatment. These activities were higher by PL-M than by PL-W, These results indicated that PL was able to increase humoral immunity and to inhibit immunotoxicity induced by CY.

• Journal of Periodontal and Implant Science
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• 제41권3호
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• pp.157-163
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• 2011

Purpose: Curcumin is known to exert numerous biological effects including anti-inflammatory activity. In this study, we investigated the effects of curcumin on the production of interleukin-6 (IL-6) by murine macrophage-like RAW 264.7 cells stimulated with lipopolysaccharide (LPS) from Prevotella intermedia, a major cause of inflammatory periodontal disease, and sought to determine the underlying mechanisms of action. Methods: LPS was prepared from lyophilized P. intermedia ATCC 25611 cells by the standard hot phenol-water method. Culture supernatants were collected and assayed for IL-6. We used real-time polymerase chain reaction to detect IL-6 mRNA expression. $I{\kappa}B-{\alpha}$ degradation, nuclear translocation of NF-${\kappa}B$ subunits, and STAT1 phosphorylation were characterized via immunoblotting. DNA-binding of NF-${\kappa}B$ was also analyzed. Results: Curcumin strongly suppressed the production of IL-6 at both gene transcription and translation levels in P. intermedia LPS-activated RAW 264.7 cells. Curcumin did not inhibit the degradation of $I{\kappa}B-{\alpha}$ induced by P. intermedia LPS. Curcumin blocked NF-${\kappa}B$ signaling through the inhibition of nuclear translocation of NF-${\kappa}B$ p50 subunit. Curcumin also attenuated DNA binding activity of p50 and p65 subunits and suppressed STAT1 phosphorylation. Conclusions: Although further study is required to explore the detailed mechanism of action, curcumin may contribute to blockade of the host-destructive processes mediated by IL-6 and appears to have potential therapeutic values in the treatment of inflammatory periodontal disease.

• Journal of Ginseng Research
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• 제35권1호
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• pp.80-85
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• 2011

Ginseng, a traditional medicine in Asian countries, is known to prevent various neuropathologic diseases such as Alzheimer's. Ginseng total saponins (GTS) in particular are one of the most effective ginseng extract compounds for neuroprotection. However, their protective effects on astrocytes are rarely reported. In pathological circumstances, astroglial activation plays a pivotal role in neuroinflammation. Subsequently, neuroinflammation induced by activated astrocytes causes brain damage. The purpose of the present study was to determine the suppressive effects of GTS on astroglial activation in lipopolysaccharide (LPS)-stimulated rat primary astrocytes. Astrocytes treated for 24 h with LPS demonstrated suppressed glialfibrillary acidic protein expression in a dose-dependent manner in the presence of GTS. GTS reduced production of proinflammatory cytokines such as tumor necrosis factor-${\alpha}$ and interleukin-1${\beta}$ and inhibited the level of inducible nitric oxide synthase, and cyclooxygenase-2 in LPS-stimulated astrocytes. Furthermore, GTS suppressed intracellular reactive oxygen species production. These modulations due to GTS may indicate neuroprotective antiinfl ammatory properties which may in turn be related to improvements in neurological performance.

• 대한수의학회지
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• 제61권3호
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• pp.22.1-22.7
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• 2021

Fenbendazole (FBZ) is a commonly used anthelmintics in veterinary medicine that has recently been found to have anticancer effects in humans. On the other hand, few studies have examined the anti-inflammatory effects of FBZ, and its mechanism is unknown. In this study, mouse bone marrow cells (BMs) were treated with lipopolysaccharide (LPS), a representative inflammation-inducing substance, to generate a situation similar to osteomyelitis in vitro. The effect of FBZ on inflammatory BMs was examined by measuring the metabolic activity, surface marker expression, cell nuclear morphology, and mitochondrial membrane potential (MMP) of BMs. FBZ decreased the metabolic activity and MMP of LPS-treated BMs. Annexin V-fluorescein isothiocyanate/propidium iodide staining and Hoechst 33342 staining showed that FBZ reduced the number of viable cells and induced the cell death of inflammatory BMs. In addition, FBZ reduced the proportion of granulocytes more than B lymphocytes in LPS-treated BMs. Overall, FBZ induces cell death by destabilizing the MMP of LPS-induced inflammatory BMs. In addition to anthelmintic and anticancer agent, FBZ can play a role as an anti-inflammatory agent.

• The Korean Journal of Physiology and Pharmacology
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• 제20권1호
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• pp.41-51
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• 2016

Adult hippocampal dentate granule neurons are generated from neural stem cells (NSCs) in the mammalian brain, and the fate specification of adult NSCs is precisely controlled by the local niches and environment, such as the subventricular zone (SVZ), dentate gyrus (DG), and Toll-like receptors (TLRs). Epigallocatechin-3-gallate (EGCG) is the main polyphenolic flavonoid in green tea that has neuroprotective activities, but there is no clear understanding of the role of EGCG in adult neurogenesis in the DG after neuroinflammation. Here, we investigate the effect and the mechanism of EGCG on adult neurogenesis impaired by lipopolysaccharides (LPS). LPS-induced neuroinflammation inhibited adult neurogenesis by suppressing the proliferation and differentiation of neural stem cells in the DG, which was indicated by the decreased number of Bromodeoxyuridine (BrdU)-, Doublecortin (DCX)- and Neuronal Nuclei (NeuN)-positive cells. In addition, microglia were recruited with activating TLR4-NF-${\kappa}B$ signaling in the adult hippocampus by LPS injection. Treating LPS-injured mice with EGCG restored the proliferation and differentiation of NSCs in the DG, which were decreased by LPS, and EGCG treatment also ameliorated the apoptosis of NSCs. Moreover, pro-inflammatory cytokine production induced by LPS was attenuated by EGCG treatment through modulating the TLR4-NF-${\kappa}B$ pathway. These results illustrate that EGCG has a beneficial effect on impaired adult neurogenesis caused by LPS-induced neuroinflammation, and it may be applicable as a therapeutic agent against neurodegenerative disorders caused by inflammation.

• Molecules and Cells
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• 제27권2호
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• pp.251-255
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• 2009

Sepsis is the leading cause of death in critically ill patients. Today, around 60% of all cases of sepsis are caused by Gram-negative bacteria. The cell wall component lipopolysaccharide (LPS) is the main initiator of the cascade of cellular reactions in Gram-negative infections. The core receptors for LPS are toll-like receptor 4 (TLR4), MD-2 and CD14. Attempts have been made to antagonize the toxic effect of endotoxin using monoclonal antibodies against CD14 and synthetic lipopolysaccharides but there is as yet no effective treatment for septic syndrome. Here, we describe an inhibitory effect of a phosphatidylethanolamine derivative, PE-DTPA (phosphatidylethanolamine diethylenetriaminepentaacetate) on LPS recognition. PE-DTPA bound strongly to CD14 ($K_d$, $9.52{\times}10^{-8}M$). It dose dependently inhibited LPS-mediated activation of human myeloid cells, mouse macrophage cells and human whole blood as measured by the production of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and nitric oxide, whereas other phospho-lipids including phosphatidylserine and phosphatidylethanolamine had little effect. PE-DTPA also inhibited transcription dependent on $NF-{\kappa}B$ activation when it was added together with LPS, and it rescued LPS-primed mice from septic death. These results suggest that PE-DTPA is a potent antagonist of LPS, and that it acts by competing for binding to CD14.

• Journal of Microbiology
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• 제33권4호
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• pp.355-362
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• 1995

Induction of antibody production in C3H/He mice by bacterial infection is regulated through the processing exerted by antigen presenting cells. From the studies with Psudomonas aeruginosa, Salmonella typhimurium, and Micrococcus luteu, lipopolysaccharides (LPS) in Gram negative bacteria, which are known to be T-cell independent B cell mitogen, seem to be the major factor stimulating immune responses via activation of macrophages. Activation of macrophage, however, does not seem to correlate with antibody production. M. luteus was easily eliminatd by activated macrophages, while the processed antigens were immediately releasedd into culture medium before presentation. Nevertheless, antigens from Gram positive bacteria, Staphylococcus aureus and Bacillus subtilis, were very very active in chemotaxis and activation of periotoneal macrophages as well as in antien presnetation, while the very nature of the antigens is not yet clearly understood.

• The Korean Journal of Physiology and Pharmacology
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• 제11권6호
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• pp.259-262
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• 2007

Diffuse panbronchiolitis (DPB) is a pulmonary disease characterized by chronic inflammation of the bronchioles and chronic infiltration of inflammatory cells in the lungs. Macrolides are effective therapeutic agents for chronic respiratory tract diseases, such as DPB. However, the mechanisms by which macrolides modulate the immune responses in patients with DPB remain unclear. To understand clinical efficacy for the treatment of DPB by macrolides, the effects of erythromycin (EM) on the expression of pro-inflammatory cytokines such as interleukin-6 (IL-6) and interleukin-8 (IL-8) by human neutrophils were examined. Pre-treatment with EM significantly decreased the expression of IL-6 and IL-8 transcripts by lipopolysaccharide (LPS)-stimulated human neutrophils. EM also reversed the enhanced survival of human neutrophils by LPS. These data indicate that EM has achieved therapeutic effect for patients with DPB, in part, through decreasing the expression of pro-inflammatory cytokines and the survival of neutrophils.

• Asian-Australasian Journal of Animal Sciences
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• 제12권2호
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• pp.180-185
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• 1999

Effects of host immunization on bacterial translocation and growth performance in weanling piglets were studied. Twenty four barrows were assigned to one of two immunization treatments: Control group (CON: immunized with placebo) or Immunization group [IMMU: immunized with Antigen cocktail; Keyhole limpet hemocyanin (KLH), Ovalbumin (OA), and Tetanus toxoid (TT)]. On d0, piglets were weaned and intramuscularly immunized with 2 ml of placebo or Antigen cocktail, respectively. Antigen-specific Ig titers were determined by ELISA (Enzyme Linked ImmunoSorbent Assay). Ig titers to E. coli-derived lipopolysaccharides (LPS) were measured as the indicator of bacterial translocation. Ig titers to LPS were higher (p<0.10, 0.05 or 0.01) in CON group before immunization (d0), but the difference disappeared with time and IgA titers to LPS became higher (p<0.05) in IMMU group on d39. In IMMU group, IgG titers to LPS from d28 onwards showed positive correlations (p<0.10, 0.05, 0.01 or 0.001) with IgG titers to KLH from d11 onwards and with IgM titers to KLH from d7 onwards. Generally, growth performance was negatively related to IgG titers to LPS. Average daily gain for d28 to d35 showed negative correlations (p<0.10, 0.05, or 0.01) with IgG titers to LPS on d28 onwards in immunization group. These results reveal some evidences that host immunization might facilitate bacterial translocation and high humoral immune responses to LPS are negatively related with the growth performance.