• The Korean Journal of Physiology and Pharmacology
• /
• v.5 no.1
• /
• pp.55-63
• /
• 2001

In macrophages, lipopolysaccharide (LPS) alone or in combination with $interferon-{\gamma}\;(IFN-{\gamma})$ has been shown to release a nitric oxide (NO) through the increase of the transcription of the inducible nitric oxide synthase (iNOS) gene. To investigate the exact intracellular signaling pathway of the regulation of iNOS gene transcription by LPS plus $IFN-{\gamma},$ the effects of protein tyrosine kinase (PTK) inhibitor and protein kinase C (PKC) inhibitors on NO production, iNOS mRNA expression, nuclear $factor-_{\kappa}B\;(NF-_{\kappa}B)$ binding activity and the promoter activity of iNOS gene containing two $NF-_{\kappa}B$ sites have been examined in a mouse macrophage RAW 264.7 cells. LPS or $IFN-{\gamma}$ stimulated NO production, and their effect was enhanced synergistically by mixture of LPS and $IFN-{\gamma}.$ The PTK inhibitor such as tyrphostin reduced LPS plus $IFN-{\gamma}-induced$ NO production, iNOS mRNA expression and $NF-_{\kappa}B$ binding activity. In contrast, PKC inhibitors such as H-7, Ro-318220 and staurosporine did not show any effect on them. In addition, transfection of RAW 264.7 cells with iNOS promoter linked to a CAT reporter gene revealed that tyrphostin inhibited the iNOS promoter activity through the $NF-_{\kappa}B$ binding site, whereas PKC inhibitors did not. Taken together, these suggest that PTK, but not PKC pathway, is involved in the regulation of the iNOS gene transcription through the $NF-_{\kappa}B$ sites of iNOS promoter in RAW 264.7 macrophages by LPS plus $IFN-{\gamma}$.

• Journal of the Korean Society of Radiology
• /
• v.13 no.1
• /
• pp.133-140
• /
• 2019

Triglycerides (TG) are one of the triggers of chronic inflammatory lesions in the blood vessels. In the key factors in the development of inflammatory diseases, Pro-inflammatory cytokines such as tumor necrosis factor-alpha $(TNF-){\alpha}$ and interleukin-1 beta ($IL-1{\beta}$) contribute to the development of inflammatory lesions by recruiting other immune cells in the inflamed area or causing cell necrotic death. In this study, I investigated the effect of Jurkat T lymphocytes and U937 monocytes involved in vascular inflammation development on the expression of $TNF-{\alpha}$ and $IL-1{\beta}$ on exposure to TGs. In Jurkat cells, mRNA expression of $TNF-{\alpha}$ is increased by exposure to TGs. However, the expression levels of $TNF-{\alpha}$ and $IL-1{\beta}$ were increased by TGs in U937 cells. To investigate whether inducible nitric oxide synthase (iNOS) is involved in the increase of expression of $TNF-{\alpha}$ and $IL-1{\beta}$ by TGs, treatment of W1400 (an iNOS inhibitor) resulted in recovery of expression level both $TNF-{\alpha}$ and $IL-1{\beta}$. Based on the present study, it was confirmed that the expression of $TNF-{\alpha}$ and $IL-1{\beta}$ in monocytes and T lymphocytes. This increased cytokines contribute to development of vascular inflammatory lesions. In addition, iNOS is involved in the increase of $TNF-{\alpha}$ and $IL-1{\beta}$ expression by TGs.

• Journal of Microbiology and Biotechnology
• /
• v.18 no.12
• /
• pp.1990-1996
• /
• 2008

Astaxanthin has shown antioxidant, antitumor, and anti-inflammatory activities; however, its molecular action and mechanism in the nervous system have yet to be elucidated. We examined the in vitro effects of astaxanthin on the production of nitric oxide (NO), as well as the expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) in lipopolysaccharide (LPS)-stimulated BV2 microglial cells. Astaxanthin inhibited the expression or formation of nitric oxide (NO), iNOS and COX-2 in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells. Astaxanthin also suppressed the protein levels of iNOS and COX-2 in LPS-stimulated BV2 microglial cells. These results suggest that astaxanthin, probably due to its antioxidant activity, inhibits the production of inflammatory mediators by blocking iNOS and COX-2 activation or by the suppression of iNOS and COX-2 degradation.

• Journal of Applied Biological Chemistry
• /
• v.64 no.4
• /
• pp.375-382
• /
• 2021

Biorenovation is a microbial enzyme-based structural modification of component compounds in natural products and synthetic compounds including plant extracts with the potential benefits of improved biological activities compared with its reaction substrates. In this study, we investigated the anti-inflammatory activity of Distylium racemosum leaf extract and D. racemosum leaf biorenovation extract (DLB). As a result, DLB inhibited nitric oxide, prostaglandin E2, and inflammatory cytokines including tumor necrosis factor-α, interleukin-6, interleukin-1β at non-toxic concentrations. In addition, DLB significantly inhibited inducible nitric oxide synthase and cyclooxygenase-2 on LPS-treated RAW 264.7 macrophages. Based on these results, we suggest that the DLB could be used as a potent anti-inflammatory agents. It also suggests that the application of biological evolution has potential usefulness to increase the practical value of natural products.

• Food Science and Biotechnology
• /
• v.16 no.5
• /
• pp.728-733
• /
• 2007

Bamboo grass, Sasa quelpaertensis, is a native plant to Jeju Island, Korea. The leaves of Sasa plants are widely used in traditional Korean medicine to treat inflammation-related diseases. We investigated the effect of hot water extract from Sasa quelpaertensis leaves (HWE-SQ) on nitric oxide (NO) production and nuclear $factor-{\kappa}B\;(NF-{\kappa}B)$ activation in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. HWE-SQ inhibited LPS-induced NO production and inducible NO synthase (iNOS) protein expression in a dose-dependent manner. Reporter gene assays indicated that HWE-SQ decreases LPS-induced $NF-{\kappa}B$ transcriptional activation. However, HWE-SQ did not affect the phosphorylation and degradation of inhibitory ${\kappa}B{\alpha}\;(1{\kappa}B{\alpha})$. HWE-SQ also directly inhibited iNOS enzyme activity in a dose-dependent manner. These results suggest that HWE-SQ suppresses NO synthesis in macrophages by attenuating $NF-{\kappa}B-mediated$ iNOS protein expression and inhibiting iNOS enzymatic activity, thereby implicating a mechanism by which HWE-SQ is able to ameliorate inflammation-related diseases by limiting excessive or prolonged NO production in pathological events.

• The Korea Journal of Herbology
• /
• v.21 no.4
• /
• pp.59-67
• /
• 2006

Objectives : Sam-Myo-Whan(SMW) has been known traditional prescription with anti- anthritis activities. We investigated inhibitory effects of SMW on lipopolysaccharide (LPS)-induced nitric oxide(NO), $TNF-{\alpha}$ and inducible nitric oxide synthase(iNOS) production from RAW264.7 cells and BV-2 Microglia cells. Methods : SMW, which had been extracted with 70% MeOH, concentrated and freeze-dried was used for this experiment. After BV2 mouse brain macrophages and RAW264.7 mouse peritoneal macrophages were pretreated with increasing concentrations of SMW extract for 30min, and then activated with LPS. To investigate cytotoxicity of SMW extract, cell viability was measured by MTT assay. NO production was measured in each culture supernatant by Griess reaction. mRNA expression of iNOS in two type cells was investigated by RT-PCR. $TNF-{\alpha}$ production was measured in each culture supernatant by ELISA. Results : SMW extract significantly inhibited LPS-induced NO and $TNF-{\alpha}$ production in BV2 cells and RAW264.7 cells dose-dependently. SMW extract also greatly suppressed mRNA expression of iNOS in both type cells activated with LPS. Conclusion : These data suggests that SMW extract may have an anti-inflammatory effect through the inhibition of iNOS expression.

• Food Science and Biotechnology
• /
• v.15 no.2
• /
• pp.270-276
• /
• 2006

We evaluated the effects of extracts of Tsunokaori tangor peel on lipopolysaccharide (LPS)-induced nitric oxide (NO) and prostaglandin $E_2\;(PGE_2)$ in RAW 264.7 cells. The ethyl acetate fraction of Tsunokaori tangor peel (EA-TTP) markedly inhibited the production of NO and $PGE_2$ in LPS-stimulated RAW 264.7 cells. Consistent with these findings, the expression levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins were down-regulated in a dose-dependent manner. Additionally, EA-TTP decreased the expression iNOS mRNA but not COX-2 mRNA. To determine the upstream signaling mechanism for the down-regulation of LPS-induced iNOS expression, we investigated the effect of EA-TTP on the degradation and re-synthesis of $I{\kappa}B{\alpha}$. EA-TTP dose-dependently delayed $I{\kappa}B{\alpha}$ degradation and increased $I{\kappa}B{\alpha}$ re-appearance following degradation, suggesting this as the mechanism by which EA-TTP suppressed iNOS gene expression. The EA-TTP also dose-dependently reduced the expression of the cellular stress-response protein heme oxygenase-1, and inhibited the LPS-induced sustained activation of extracellar signal-regulated kinase (ERK).

• Biomolecules & Therapeutics
• /
• v.16 no.4
• /
• pp.385-393
• /
• 2008

As an attempt to search for bioactive natural products exerting anti-inflammatory activity, we evaluated the effects of the methanol extract of Polytrichum commune Hedw (PCM) (Polytrichaceae) on lipopolysaccharide (LPS)-induced nitric oxide (NO), prostaglandin $E_2$ ($PGE_2$) and pro-inflammatory cytokines release in murine macrophage cell line RAW 264.7. PCM potently inhibits the production of NO, $PGE_2$, tumor necrosis factor (TNF)-$\alpha$ and interleukin (IL)-6. Consistent with these results, PCM also concentration-dependently inhibited LPS-induced inducible NO synthase (iNOS) and cyclooxygase (COX)-2 at the protein levels, and iNOS, COX-2, TNF-$\alpha$ and IL-6 at the mRNA levels without an appreciable cytotoxic effect on RAW 264.7 macrophag cells. Furthermore, PCM inhibited LPS-induced nuclear factor-kappa B (NF-$\kappa$B) activation as determined by NF-$\kappa$B reporter gene assay, and this inhibition was associated with a decrease in the nuclear translocation of p65 and p50 NF-$\kappa$B. Taken together, these results suggest that PCM may play an anti-inflammatory role in LPS-stimulated RAW 264.7 macrophages through the inhibitory regulation of iNOS, COX-2, TNF-$\alpha$ and IL-6 via NF-$\kappa$B inactivation.

• Molecules and Cells
• /
• v.23 no.3
• /
• pp.398-404
• /
• 2007

Cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) are involved in various pathophysiological processes such as inflammation and carcinogenesis. In a search for inhibitors of COX-2 and iNOS production we found that extracts of Stewartia koreana strongly inhibited NO and $PGE_2$ production in LPS-treated macrophage RAW 264.7 cells. We have now shown that the mRNA and protein levels of iNOS and COX-2 are reduced by the Stewartia koreana extract (SKE). SKE inhibited expression of an NF-${\kappa}B$ reporter gene in response to LPS, and gel mobility shift assays revealed that SKE reduced NF-${\kappa}B$ DNA-binding activity. The extract also inhibited LPS-induced phosphorylation of $I{\kappa}B-{\alpha}$ and nuclear translocation of p65. Administration of the extract reduced the symptoms of arthritis in a collagen-induced arthritic mouse model. These results indicate that Stewartia extracts contain potentially useful agents for preventing and treating inflammatory diseases.

• Journal of Life Science
• /
• v.16 no.7 s.80
• /
• pp.1181-1187
• /
• 2006

HS-1580 series (HS-1580, HS-1581, HS-1582) can produce anti-imflammatory effects were synthesized from the marine algae extraction in 2,3,6-tribromo-4,5-dihydroxy benzyl methyl ether (TDB). Raw 264.7 cells were pre-treated with $1{\mu}g/{\mu}l$ lipopolysaccharide (LPS) and later treated with HS-1580 series. These cells of inflammatory mediators were tested as well. Nitric oxide (NO) is related to autoimmune disease and is produced by inducible NOS (iNOS). When treated with HS-1580 series, the product of NO will reduce in a dose-dependent manner. HS-1580 series significantly inhibit the iNOS protein expression. Cyclooxygenase (COX) involves with the various physiologic events and catalyzes in prostaglandin. HS-1580 series also inhibit the COX-2 protein expression as well as pro-inflammatory cytokines production such as tumor necrosis $factor-{\alpha}\;(TNF-{\alpha})\;and\;interluekin-1{\alpha]\;(IL-1{\beta})$. These upcoming results suggest that HS-1580 series have anti-inflammatory efforts in Raw 264.7 cells by inhibiting such as iNOS, COX-2, $TNF-{\alpha}\;and\;IL-1{\beta}$ as inflammatory mediators.