• Molecular & Cellular Toxicology
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• v.4 no.1
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• pp.16-21
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• 2008

Cell death of trophoblast, particularly by abnormal release of physiological nitric oxide (NO) has been known to be a causative factor of pre-eclampsia. In the present study, effects of intracellular calcium increase enhancing the activity of NO synthases (neuronal NO synthase, nNOS in this trophoblast cells) on the cell death were examined in a human placental full-term cell line (HT-1). Furthermore, we analyzed the possible mechanisms underlying the augmentation of $Ca^{++}$-mediated NOS activity mediated by protein kinases like PKC, PKA, or CaM-KII. In experiments for cell toxicity, a calcium ionophore (ionomycin $10{\mu}M$) enhanced cell death confirmed by MTT assay, and increased significantly nNOS activity determined with a hemoglobin oxidation assay. This cell death was partially protected by pre-treatment of 7-nitroindazole (7-NI, $10{\mu}M$ and $100{\mu}M$), a nNOS-specific inhibitor. Additionally, $Ca^{++}$-ionophore -induced increase of nNOS activity also was partially normalized by pre-treatment of specific inhibitors of protein kinases, PKC, PKA or CaM-KII. Therefore, we suggest that an increase of calcium influx, leading to the activation of nNOS activity, which in turn may result in the death of trophoblast cells by involvement of signaling mechanisms of protein kinases.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.9
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• pp.1204-1210
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• 2011

Objective of this study was to examine the effect of sodium nitroprusside (SNP), a nitric oxide (NO) donor on steroid synthesis, growth and apoptosis of buffalo granulosa cells (GCs) in vitro. Follicular fluid of antral follicles (3-5 mm diameter) was aspirated and GCs were cultured in 0 (control), $10^{-3}$, $10^{-5}$, $10^{-7}$, $10^{-9}\;M$ of SNP for 48 h. To evaluate whether this effect was reversible, GCs were cultured in presence of $10^{-5}\;M$ SNP+1.0 mM $N^{\omega}$-nitro-L-arginine methyl ester (L-NAME) a NO synthase (NOS) inhibitor or hemoglobin (Hb, $1.0{\mu}g$) as NO scavenger. Nitrate/nitrite concentration was evaluated by Griess method, progesterone and estradiol concentrations by RIA and apoptosis by TUNEL assay. SNP ($10^{-3}$, $10^{-5}$, $10^{-7}\;M$) significantly (p<0.05) inhibited estradiol and progesterone synthesis, growth, disorganized GCs aggregates and induced apoptosis in a dose dependent manner. However, $10^{-9}\;M$ SNP induced the progesterone synthesis and stimulated GCs to develop into a uniform monolayer. Combination of SNP $10^{-5}$ M+L-NAME strengthened the inhibitory effect while, SNP+Hb together reversed these inhibitory effects. In conclusion, SNP at greater concentrations ($10^{-3}$, $10^{-5}$ and $10^{-7}\;M$) has a cytotoxic effect and it may lead to cell death whereas, at a lower concentration ($10^{-9}\;M$) induced progesterone synthesis and growth of GCs. These findings have important implications that NOS derived NO are involved at physiological level during growth and development of buffalo GCs which regulates the steroidogenesis, growth and apoptosis.

• The Korean Journal of Pain
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• v.12 no.2
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• pp.171-176
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• 1999

Background: Effect of nitric oxide on the hyperalgesia induced by inflammation is controversial. From our previous experiment, NOS inhibitor, L-NAME given during the induction period decrease mechanical hyperalgesia occured by Freund's complete adjuvant induced inflammation. In addition, we attempted to analyze the effects of L-NAME on mechanical hyperalgesia after the development of inflammation by Freund's complete adjuvant in rat paw. Methods: Male Sprague Dawley rats were divided into four groups; control (normal saline), and three different doses of L-NAME (0.1 mg, 1 mg, 10 mg). Inflammation was induced in rats by injecting 0.15 ml of Freund's complete adjuvant (FCA) intraplantarly. Rats showed typical hyperalgesia within twelve hours after injection and maintained this for about one week. Tests were done 2 days after injection of FCA. After the baseline test either L-NAME or saline was injected under light halothane anesthesia. Effect of L-NAME on hyperalgesia was assessed by measuring mechanical hyperalgesia at 15, 30, 60, 90, 120 minutes. Same experients were repeated on normal rats. Results: When injected at the site of inflammation, L-NAME caused dose dependent decrease in mechanical hyperalgesia. However, normal rats also showed increased mechanical threshold after L- NAME injection. Conclusions: Although L-NAME reduces FCA induced mechanical hyperalgesia, this result may solely be due to inhibition of nitric oxide production and need to be further determined.

• The Journal of Korean Medicine
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• v.29 no.1
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• pp.47-59
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• 2008

Objective : Anti-inflammatory effects of the extract of Lycii Fructus on lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 macrophage cells were investigated. Method : In order to assess the cytotoxic effect of Lycii Fructus on the raw 264.7 macrophages 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay was performed. Reverse transcription-polymerase chain reaction(RT-PCR) analysis of the mRNA levels of tumor necrosis factor-$\alpha$(TNF-$\alpha$) and inducible nitric oxide synthase(iNOS) was performed in order to provide an estimate of the relative level of expression of these genes. The protein level of the inhibitor of nuclear factor-${\kappa}B(I{\kappa}B)$ and nuclear factor-${\kappa}B$(NF-${\kappa}B$) activity was investigated by Western blot assay. NO production was investigated by NO detection. Result : Lycii Fructus suppressed NO production by inhibiting the LPS-induced expressions of iNOS and TNF-$^-\alpha$ mRNA and iNOS protein in RAW 264.7 macrophage cells. Also, Lycii Fructus suppressed activation of NF-${\kappa}B$ in the nucleus. Conclusion : These results show that the extract of Lycii Fructus has anti-inflammatory effect probably by suppressing iNOS expressions through the down-regulation of NF-${\kappa}B$ binding activity.

• Journal of Microbiology and Biotechnology
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• v.30 no.6
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• pp.822-829
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• 2020

Nutraceutical treatments can reduce inflammation and prevent the development of inflammatory diseases. In this study, the anti-inflammatory effects of Smilax guianensis Vitman extract (SGE) were examined. SGE suppressed lipopolysaccharide (LPS)-mediated nitrite production in RAW 264.7 cells. SGE also prevented the LPS-induced expression of inducible nitric oxide synthase (iNOS) but not cyclooxygenase (COX)-2. Western blot analysis showed that SGE attenuated LPS-induced phosphorylation of IκB kinase (IKK), inhibitor of kappa B (IκB), and p65. Additionally, SGE inhibited LPS-induced IκB degradation in RAW 264.7 cells. Western blot analysis of the cytosolic and nuclear fractions, as well as immunofluorescence assay results, revealed that SGE suppressed LPS-induced p65 nuclear translocation in RAW 264.7 cells. Moreover, SGE reduced LPS-induced interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) mRNA expression and IL-1β and IL-6 protein expression in RAW 264.7 cells. Collectively, these results indicate that SGE suppresses the NF-κB signaling pathway and thereby inhibits the production of NO, IL-1β, and IL-6.

• Applied Biological Chemistry
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• v.48 no.4
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• pp.411-417
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• 2005

Aqueous extracts were prepared from 21 medicinal herbs including Herba Pogostemi (Agastache rugosa) to examine their modulatory effects on NO production in mouse macrophage cell line RAW264.7 cells. While almost all medicinal herb extracts failed to show marked scavenging activities to NO produced by LPS stimulation, only Herba Pogostemi showed a rather strong induction of NO production in RAW264.7 cells without stimulation with LPS. When we treated the cell with $200{\mu}M\;of\;N^G-monomethyl-L-arginine\;(N^GMMA)$, a NOS2 inhibitor, a significant reduction in NO production could be observed. Moreover, a treatment of $100{\mu}M$ pyrrolidine dithiocarbamate (PDTC) led to about a 79% reduction of NO production. These results demonstrated that the aqueous extract of Herba Pogostemi might provide a second signal for the expression of NOS2 in RAW264.7 cells, and suggested that Herba Pogostemi induces NO production through L-argininedependent pathway.

• Journal of Korean Neurosurgical Society
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• v.38 no.4
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• pp.287-292
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• 2005

Objective : Kainic acid[KA] enhances the expression of nitric oxide synthase, increases nitric oxide[NO], and thus evokes epileptic convulsion, which results in neuronal damage in the rat brain. NO may stimulate cyclooxygenase type-2 [COX-2] activity, thus producing seizure and neuronal injury, but it has also been reported that KA-induced seizure and neurodegeneration are aggravated on decreasing the COX-2 level. This study was undertaken to investigate whether the suppression of NO using the NOS inhibitor, N-nitro-L-arginine methyl ester[L-NAME], suppresses or enhances the activity of COX-2. Methods : Silver impregnation and COX-2 immunohistochemical staining were used to localize related pathophysiological processes in the rat forebrain following KA-induced epileptic convulsion and L-NAME pretreatment. Post-injection survival of the rat was 1, 2, 3days and 2months, respectively. Results : After the systemic administration of KA in rats, neurodegeneration increased with time in the cornu ammonis [CA] 3, CA 1 and amygdala, as confirmed by silver impregnation. On pretreating L-NAME, KA-induced neuronal degeneration decreased. COX-2 enzyme activities increased after KA injection in the dentate gyrus, CA 3, CA 1, amygdala and pyriform cortex, as determined by COX-2 staining. L-NAME pretreatment prior to KA-injection, caused COX-2 activities to increase compared with KA- injection only group by 1day and 2days survival time point. Conclusion : These results suggest that L-NAME has a neuroprotective effect on KA-induced neuronal damage, especially during the early stage of neurodegeneration.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.6
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• pp.363-369
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• 2011

The present study elucidated the effect of the selective inducible nitric oxide synthase (iNOS) inhibitor $N^6$-(1-iminoethyl)-L-lysine (L-NIL) on monosodium urate (MSU) crystal-induced inflammation and edema in mice feet. L-NIL (5 or 10 mg/kg/day) was administered intraperitoneally 4 h before injection of MSU (4 mg) into the soles of mice hindlimb feet. Twenty-four hours after MSU injection, foot thickness was increased by 160% and L-NIL pretreatment reduced food pad swelling in a dose dependent manner. Pretreatment of 10 mg/kg/day L-NIL significantly suppressed the foot pad swelling by MSU. Plasma level of nitric oxide (NO) metabolites and gene expression and protein level of iNOS in feet were increased by MSU, which was suppressed by L-NIL pretreatment. Similar pattern of change was observed in nitrotyrosine level. MSU increased the gene expression of tumor necrosis factor (TNF)-${\alpha}$ and interleukin (IL)-$1{\beta}$ and L-NIL pretreatment suppressed MSU-induced cytokines expression. The mRNA levels of superoxide dismutase and glutathione peroxidase1 were increased by MSU and L-NIL pretreatment normalized the gene expression. Phosphorylation of extracellular signal-regulated kinase 1/2 and p38 was increased by MSU, which was suppressed by L-NIL pretreatment. The mRNA levels of iNOS, TNF-${\alpha}$, and IL-$1{\beta}$ were increased by MSU in human dermal fibroblasts, C2C12 myoblasts, and human fetal osteoblasts in vitro, which was attenuated by L-NIL in a dose dependent manner. This study shows that L-NIL inhibits MSU-induced inflammation and edema in mice feet suggesting that iNOS might be involved in MSU-induced inflammation.

• Animal cells and systems
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• v.12 no.1
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• pp.15-21
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• 2008

Nitric oxide(NO) has been known to play important roles in numerous physiologic processes including neurotransmission, vasorelaxation, and cellular apoptosis. Using a mouse cDNA gene chip, we examined expression patterns and time course of NO-dependent genes in mouse macrophage RAW264.7 cells. Genes shown to be upregulated more than two fold or at least at two serial time points were further selected and validated by RT-PCR. Finally, 81 selected genes were classified by function as signaling, apoptosis, inflammation, transcription, translation, ionic homeostasis and metabolism. Among those, genes related with signaling, apoptosis and inflammation, such as guanylate cyclase 1, soluble, alpha3(Gucy1a3); protein kinase C, alpha($Pkc{\alpha}$); lymphocyte protein tyrosine kinase(Lck); BCL2/adenovirus E1B 19 kDa-interacting protein(Bnip3); apoptotic protease activating factor 1(Apaf1); X-linked inhibitor of apoptosis(Xiap); cyclin G1(Ccng1); chemokine(C-C motif) ligand 4(Ccl4); B cell translocation gene 2, anti-proliferative(Btg2); lysozyme 2(Lyz2); secreted phosphoprotein 1(Spp1); heme oxygenase(decycling) 1(Hmox1); CD14 antigen(Cd14); and granulin(Grn) may play important roles in NO-dependent responses in murine macrophages.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.6
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• pp.1284-1290
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• 2002

Scrophularia buergeriana Miquel (Scrophulariaceae) has been used as an anti-inflammatory drug in the folk medicine recipe and been proved its anti-inflammatory effect in the oriental medicine. Since nitric oxide (NO) and superoxide anion (O/sub 2//sup -/) are ones of the major inflammatory parameters, we studied the effect of aqueous extracts of Scrophularia buergeriana (SB) on NO and O/sub 2//sup -/ production in lipopolysaccharide (LPS)-stimulated mouse peritoneal macrophages. NO, O/sub 2//sup -/production and inducible NO synthase (iNOS) level were significantly reduced in LPS-activated macrophages by SB compared to those without. Electrophoretic mobility shift assay (EMSA) indicated that SB blocked the activation of NF-kB, which was considered to be a potential transcription factor for the iNOS expression. SB also blocked degradation of IkBα. Furthermore, IkB kinase alpha (IKKα), which phosphorylates serine residues of IkB directly, is inhibited by SB. These results suggest that SB could exert its anti-inflammatory actions by suppressing the activation of NF-kB through inhibition of IKK activity.