• Fisheries and Aquatic Sciences
• /
• v.14 no.4
• /
• pp.275-282
• /
• 2011

Inflammatory mediators such as inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) have been implicated in various inflammatory diseases. In this study, we investigated the anti-inflammatory activities of Chondria crassicaulis ethanolic extract (CCE) by measuring its effects on the expression of iNOS and COX-2 proteins in lipopolysaccharide (LPS)-treated RAW 264.7 murine macrophages. CCE significantly and dose-dependently inhibited the LPS-induced release of nitric oxide and prostaglandin $E_2$, and suppressed the expression of iNOS and COX-2 proteins in LPS-stimulated RAW 264.7 cells, without causing any cytotoxicity. It also inhibited the production of the pro-inflammatory cytokines such as interleukin (IL)-$1{\beta}$, IL-6, and tumor necrosis factor (TNF)-${\alpha}$ in LPS-stimulated RAW 264.7 cells. Moreover, treatment with CCE strongly suppressed nuclear factor-${\kappa}B$ (NF-${\kappa}B$) promoter-driven expression in LPS-treated RAW 264.7 cells. CCE treatment blocked nuclear translocation of the p65 subunit of NF-${\kappa}B$ by preventing proteolytic degradation of inhibitor of ${\kappa}B-{\alpha}$. These results indicate that CCE regulates iNOS and COX-2 expression through NF-${\kappa}B$-dependent transcriptional control, and identifies potential candidates for the treatment or prevention of inflammatory diseases.

• Archives of Pharmacal Research
• /
• v.27 no.12
• /
• pp.1220-1225
• /
• 2004

The overproduction of nitric oxide (NO) by inducible nitric oxide synthase (iNOS) is known to be responsible for vasodilation and hypotension observed in septic shock and inflammation. Inhibitors of iNOS, thus, may be useful candidates for the treatment of inflammatory diseases accompanied by overproduction of NO. In the course of screening oriental anti-inflammatory herbs for the inhibitory activity of NO synthesis, a crude methanolic extract of Curcuma zedoaria exhibited significant activity. The activity-guided fractionation and repetitive chromatographic procedures with the EtOAc soluble fraction allowed us to isolate three active compounds. They were identified as 1,7-bis (4-hydroxyphenyl)-1,4,6-heptatrien-3-one (1), procurcumenol (2) and epiprocurcumenol (3) by spectral data analyses. Their concentrations for the 50% inhibition of NO production $(IC_{50})$ in lipopolysaccharide (LPS)-activated macrophages were 8, 75, 77 ${\mu}M$, respectively. Compound 1 showed the most potent inhibitory activity for NO production in LPS-activated macrophages, while the epimeric isomers, compound 2 and 3 showed weak and similar potency. Inhibition of NO synthesis by compound 1 was very weak when activated macrophages were treated with 1 after iNOS induction. In the immunoblot analysis, compound 1 suppressed the expression of iNOS in a dose-dependent manner. In summary, 1,7-bis (4-hydroxyphenyl)-1,4,6-heptatrien-3-one from Curcuma zedoaria inhibited NO production in LPS-activated macrophages through suppression of iNOS expression. These results imply that the traditional use of C. zedoaria rhizome as anti-inflammatory drug may be explained at least in part, by inhibition of NO production.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.20 no.1 s.32
• /
• pp.1-15
• /
• 2007

Objectives : RVC has long been used for a useful natural agent ameliorating inflammation related symptoms in the folk medicine recipe. This study was performed to investigate effects of RVC on the inflammation and oxidation in RAW 264.7 cells. Methods : The RVC was extracted with 80% ethanol and sequentially partitioned with solvents in order to increase polarity. With the various fractions, we determined the activities on the inflammation and oxidation in RAW 264.7 cells. Results : 1. Among the various solvent extracts of RVC, the butanol fraction showed the most powerful inhibitory ability against nitric oxide (NO) production in lipopolysaccharide (LPS)-induced RAW 264.7 cells without affecting cell viability. 2. Butanol fraction showed a oxidation inhibition effect by decreasing the DPPH and OH radicals. 3. Butanol fraction exhibited the inhibitory avilities against iNOS and COX-2. 4. Reverse transcriptase polymerase chain reaction (RT-PCR) and Westem blotting analysis revealed that the BuOH fraction provided a primary inhibitor of the iNOS protein and mRNA expression in LPS-induced RAW 264.7 cells. Among the up-regulater molecules of iNOS and COX-2, the BuOh fraction of RVC was shown the inhibitory activity of phoshporylation of c-Jun N-terminal kinase (JNK) 1/2 and threonine protein kinase (AKT), the one of the MAPKs pathway. Conclusion : Thus, the present study suggests that the response of a component of the BuOH fraction to NO generation via iNOS expression provide a important clue to elucidate anti-inflammatory and anti-oxidation mechanism of RVC.

• Journal of Life Science
• /
• v.27 no.1
• /
• pp.8-14
• /
• 2017

Died Gardenia jasminoides fruit is used as a dye in the food and clothes industries in Asia. The present study investigated the anti-inflammatory effects of aqueous extract of G. jasminoides fruits (GJ) in BV-2 microglial cells. GJ inhibited lipopolysaccharide-induced nitric oxide (NO) secretion, inducible nitric oxide synthase (iNOS) expression, and reactive oxygen species production, without affecting cell viability. Furthermore, GJ increased the expression of heme oxygenase-1 (HO-1) in a dose-dependent manner. Moreover, the inhibitory effect of GJ on iNOS expression was abrogated by small interfering RNA-mediated knock-down of HO-1. In addition, GJ induced nuclear translocation of nuclear factor E2-related factor 2 (Nrf2), a transcription factor that regulates HO-1 expression. GJ-mediated expression of HO-1 was suppressed by LY294002, a phosphoinositide 3-kinase (PI-3K) inhibitor, and SB203580, a p38 kinase inhibitor, but not by the extracellular signal-regulated kinase (ERK) inhibitor PD98059 or c-Jun N-terminal kinase (JNK) inhibitor SP600125. GJ also enhanced the phosphorylation of Akt and p38. These results suggest that GJ suppresses the production of NO, a pro-inflammatory mediator, by inducing HO-1 expression via PI-3K/Akt/p38 signaling. These findings illustrate a novel molecular mechanism by which extract from G. jasminoides fruits inhibits neuroinflammation.

• Molecular & Cellular Toxicology
• /
• v.1 no.3
• /
• pp.196-202
• /
• 2005

Nitric oxide (NO) is a small, diffusible, and highly reactive molecule, which plays dichotomous regulatory roles under physiological and pathological conditions. NO promotes apoptosis in some cells, and inhibits apoptosis in other cells. In the present study, we attempted to characterize the NO signaling pathway and cellular response in PC12 cells treated with cytokines. $IFN{\gamma}\;and\;TNF{\alpha}$ treatment resulted in a synergistic increase of nitrite accumulation, with the induction of inducible nitric oxide synthase (iNOS) in the PC12 cells. Moreover, as nitrite concentration increased, cell viability decreased. In order to explore MAP kinase involvement in nitric oxide production resultant from $IFN{\gamma}\;and\;TNF{\alpha}$ stimulation, we measured the activation of MAP kinase using specific MAP kinase inhibitors. PC12 cells pretreated with SB203580, a p38 MAP kinase-specific inhibitor, resulted in the inhibition of iNOS expression and NO production. However, PD98059, an ERK/MAP kinase-specific inhibitor, was not observed to exert such an effect. In addition, Stat1 activated by $IFN{\gamma}\;and\;TNF{\alpha}$ was interacted with p38 MAPK. These data suggest that p38 MAP kinase mediates cytokine-mediated iNOS expression in the PC12 cells, and Jak/Stat pathway interferes with p38 MAPK signaling pathway.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.17 no.1
• /
• pp.163-171
• /
• 2004

The flowers of Lonicera japonica Thunb. (Caprifoliaceae) has been used as anti-inflammatory drug in the folk medicine recipe and been proved its anti-inflammatory effect in the oriental medicine. However, the action mechanism of Lonicera japonica that exhibits anti-inflammatory effects has not been determined. Since nitric oxide (NO) is one of the major inflammatory parameter, we studied the effect of aqueous extracts of Lonicera japonica (AELJ) on NO production in lipopolysaccharide (LPS)-stimulated mouse peritoneal macrophages. NO and inducible NO synthase (iNOS) level were significantly reduced in LPS-stimulated macrophages by AELJ compared to those without Electrophoretic mobility shift assay (EMSA) indicated that AELJ blocked the activation of nuclear factor kappa B (NF-kB), which was considered to be a potential transcription factor for the iNOS expression. AELJ also blocked the phosphorylation and degradation of inhibitor of kappa B-alpha (IkB-${\alpha}$). Furthermore, IkB kinase alpha (IKK${\alpha}$), which is known to phosphorylate serine residues of IkB directly, is inhibited by AELJ in vivo and in vitro. These results suggest that AELJ could exert its anti-inflammatory actions by suppressing the synthesis of NO through inhibition of NF-kB activity.

• Biomolecules & Therapeutics
• /
• v.21 no.4
• /
• pp.258-263
• /
• 2013

We demonstrate herein that silibinin, a polyphenolic flavonoid compound isolated from milk thistle (Silybum marianum), inhibits LPS-induced activation of macrophages and production of nitric oxide (NO) in RAW 264.7 cells. Western blot analysis showed silibinin inhibits iNOS gene expression. RT-PCR showed that silibinin inhibits iNOS, TNF-${\alpha}$, and $IL1{\beta}$. We also showed that silibinin strongly inhibits p38 MAPK phosphorylation, whereas the ERK1/2 and JNK pathways are not inhibited. The p38 MAPK inhibitor abrogated the LPS-induced nitrite production, whereas the MEK-1 inhibitor did not affect the nitrite production. A molecular modeling study proposed a binding pose for silibinin targeting the ATP binding site of p38 MAPK (1OUK). Collectively, this series of experiments indicates that silibinin inhibits macrophage activation by blocking p38 MAPK signaling.

• Environmental Analysis Health and Toxicology
• /
• v.15 no.3
• /
• pp.69-80
• /
• 2000

ADP-rubosylation may be involved in the process of macrophage activation. Nitric oxide (NO) has emerged as an important intracellular and interacellular regulatory molecule with function as diverse as vasodilation, neural communication or host defense. NO is derived from the oxidation of the terminal guanidino nitrogen atom of L-arginine by the NADPH -dependent enzyme, nitric oxide synthase (NOS) which is one of the three different isomers in mammalian tissues. Since NO can exert protective or regulatory functions in the cell at a low concentration while toxic effects at higher concentrations, its role may be tightly regulated in the cell. Therefore, this paper was focused on signal transduction pathway of NO synthesis, role of endogenous TGF-$\beta$ in NO production. effect of NO on superoxide formation. Costimulation of murine peritoneal macrophages with interferon-gamma (IFN-γ) and phorbol 12-myristate 13-acetate (PMA) increased both NO secretion and mRNA expression of inducible nitric oxide synthase (iNOS) when PMA abolished costimulation. Pretreatmnet of the cells with PMA abolished costimuation effects due to the depletion of protein kinase C (PKC) activities . The involvement of PKC in NO secretion could be further confirmed by PKC inhibitor, stauroprine, and phorbol ester derivative, phorbol 12,13-didecanoate. Addition of actinomycine D in IFN-γ plus PMA stimulated cells inhibited both NO secretion and mRNA expression of iNOS indication that PMA stabilizes mRNA of iNOS . Exogenous TGF-$\beta$ reduced NO secretion in IFN -γ stimulated murine macrophages. However addition of antisense oligodeoxynucleotide (ODN) to TGF-$\beta$ to this system recovered the ability of NO production and inhibited mRNA expression of TGF-$\beta$. ACAS interactive laser cytometry analysis showed that transportation of FITC -labeled antisense ODN complementary to TGF-$\beta$ mRNA could be observed within 5 min and reached maximal intensity in 30 min in the murine macrophage cells. NO released by activated macrophages inhibits superoxide formation in the same cells . This inhibition nay be related on NO-induced auto -adenosine diphosphate (ADP) -ribosylation . In addition, ADP-ribosylation may be involved in the process of macrophage activation .

• The Journal of Korean Medicine
• /
• v.22 no.3
• /
• pp.1-10
• /
• 2001

Objectives : The water extract of Nueihyuljunbang (NHJB) has long been used for treatment of ischemic brain damage in Oriental Medicine. However, little is known about the mechanism by which the water extract of NHJB recovers brain cens from ischemic damage. Methods : To elucidate the protective mechanism on ischemic induced cytotoxicity, we investigated the regulation of lipopolysaccharide (LPS) and phorbol-12-myristate-13-acetate (PMA)-induced inducible nitric oxide synthase (iNOS) expression in C6 glial cells. Results : LPS combined PMA treatment for 72 hours in C6 glial cells markedly induced nitric oxide (NO), but treatment of the cells with the water extract of NHJB decreased dose-dependently nitrite formation. In addition, LPS combined PMA treatment for 72 hours induced severe celt death and lactate dehydrogenase (LDH) release in C6 glial cells. However, treatment of the celts with the water extract of NHJB did not induce significant change compared to control cells. Furthermore, the protective effects of the water extract of NHJB were mimicked by the treatment of NGMMA, a specific inhibitor of NOS. LPS combined PMA induced iNOS activation in C6 glial cells caused chromosomal condensation and fragmentation of the nuclei by caspase activation. The treatment of C6 glial cells with the water extract of NHJB might suppress apoptosis via caspase inhibition by regulation of iNOS expression. Conclusions : From the results, we suggest that the protective effects of the water extract of NHJB against ischemic brain damage may be mediated by regulation of iNOS during ischemic condition.

• Archives of Pharmacal Research
• /
• v.25 no.5
• /
• pp.691-696
• /
• 2002

Doxorubicin (DOX) is an active and broad spectrum chemotherapeutic agent. Increased inducible nitric oxide synthase (NOS) expression and/or activity have been reported in several human tumors. While the relationship between DOX treatment and the enzymatic activity of endothelial NOS has been well characterized, little is known about the effects of DOX on the expression of iNOS in human cancer cells. In the present study, we characterized the effects of DOX on the nitric oxide (NO) production by colorectal cancer cells, DLD-1. IFN-${\gamma}$/IL-1$\beta$ (CM) increased the production of NO, whereas pretreatment of DOX inhibited the production of NO in response to CM in a dose dependent manner. The increased expressions of iNOS mRNA and protein by CM were completely blocked by DOX without affecting the iNOS mRNA stability. However, DOX activated nuclear factor-kB (NF-kB) in response to CM. Furthermore, the expression of inhibitor kB$\alpha$ was reduced by DOX in a dose dependent manner. Collectively, DOX inhibited the production of NO by DLD-1 cells, which is not linked to well known transcription factor, NF-kB. Therefore, further studies on the possible mechanisms of inhibitory effects of NO production by DOX would be worth pursuing.