• Archives of Pharmacal Research
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• v.23 no.1
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• pp.54-58
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• 2000

To elucidate the molecular mechanisms for the suppression of LPS-induced nitric oxide (NO) production by a dehydrocostus lactone (DL) from Saussurea lappa, we examined the preventive effect of this compound on $NF-{\kappa}B$ activation in LPS-treated RAW 264.7 macrophages and U937 human monocytic cells. The results suggest that the suppression of NO production is mediated by the inhibitory action on the i-NOS gene expression through the inactivation of $NF-{\kappa}B$ and this sesquiterpene lactone can act as a pharmacological inhibitor of the $NF-{\kappa}B$ activation.

• Journal of Periodontal and Implant Science
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• v.35 no.1
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• pp.9-19
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• 2005

Both nitric oxide (NO) and interleukin-6 (IL-6) have been thought to have a role in the pathogenesis of inflammatory periodontal disease as it does in other inflammatory diseases, and the inhibitors of NO and IL-6 production have been considered as potential anti-inflammatory agents. In this study, we evaluated methanol extract of Sophorae Flos for inhibition of NO and IL-6 production in Prevotella intermedia LPS-induced mouse macrophages RAW264.7 cells. Dried Sopharae Flos was sliced, and extracted with 100% methanol. LPS from p. intermedia ATCC 25611 was prepared by the standard hot phenol-water method. NO production was assayed by measuring the accumulation of nitrite in culture supematants and IL-6 was measured using mouse IL-6 ELISA kit. Western blot analysis of iNOS and analysis of reverse transcription (RT)-PCR products were carried out. The methanol extract of Sophorae Flos concentration-dependently reduced the production of NO and the expression of iNOS protein and mRNA in RAw264.7 cells treated with P. intermedia LPS. Sophorae Flos also suppressed IL-6 production and the expression of IL-6 mRNA in RAw264.7 cells stimulated by P. intermedia LPS. The inhibition of NO and IL-6 production by Sophorae Flos may be useful in the therapy of inflammatory diseases such as periodontitis. This hypothesis, however, remains to be tested.

• The Korean Journal of Pain
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• v.33 no.1
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• pp.30-39
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• 2020

Background: This study examined the effects of gabexate mesilate on spinal nerve ligation (SNL)-induced neuropathic pain. To confirm the involvement of gabexate mesilate on neuroinflammation, we focused on the activation of nuclear factor-κB (NF-κB) and consequent the expression of proinflammatory cytokines and inducible nitric oxide synthase (iNOS). Methods: Male Sprague-Dawley rats were used for the study. After randomization into three groups: the sham-operation group, vehicle-treated group (administered normal saline as a control), and the gabexate group (administered gabexate mesilate 20 mg/kg), SNL was performed. At the 3rd day, mechanical allodynia was confirmed using von Frey filaments, and drugs were administered intraperitoneally daily according to the group. The paw withdrawal threshold (PWT) was examined on the 3rd, 7th, and 14th day. The expressions of p65 subunit of NF-κB, interleukin (IL)-1, IL-6, tumor necrosis factor-α, and iNOS were evaluated on the 7th and 14th day following SNL. Results: The PWT was significantly higher in the gabexate group compared with the vehicle-treated group (P < 0.05). The expressions of p65, proinflammatory cytokines, and iNOS significantly decreased in the gabexate group compared with the vehicle-treated group (P < 0.05) on the 7th day. On the 14th day, the expressions of p65 and iNOS showed lower levels, but those of the proinflammatory cytokines showed no significant differences. Conclusions: Gabexate mesilate increased PWT after SNL and attenuate the progress of mechanical allodynia. These results seem to be involved with the antiinflammatory effect of gabexate mesilate via inhibition of NF-κB, proinflammatory cytokines, and nitric oxide.

• Toxicological Research
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• v.22 no.3
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• pp.245-251
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• 2006

Nitric oxide(nitrogen monoxide, NO) plays important physiological roles, but excessive generation can be toxic. NO is present in cigarette smoke at up to 1,000 ppm, and probably represents one of the greatest exogenous sources of NO to which humans are exposed. We investigated whether cigarette smoking reduces the production of endogenous NO and whether it influences the action of lipopolysaccharide(LPS) to induce nitric oxide synthase activity in mouse brain. Mice(C57BL6/J) were exposed to cigarette smoke for 8 weeks. LPS was injected intraperitoneally in single or combination with the exposure to cigarette smoke. Six hours after the injection of LPS, mice were sacrificed and sera and brains were collected. Serum concentrations of nitrate and nitrite were not charged by 4-week smoke exposure, but were significantly increased by 6 and 8 weeks of smoke exposure. Interestingly, cigarette smoke reduced the elevation in serum nitrate and nitrite concentrations produced by LPS after 4-week smoking exposure. NO synthase(NOS) activity in brain was upregulated by LPS-administration. However, cigarette smoke exposure remarkably and consistently decreased the LPS-induced activity in mouse brain. This result suggests that cigarette smoking may affect against overproduction of the endogenous NO by LPS through the inhibition of NOS activity induced by LPS in brain or by modulation of the LPS action for the induction of NOS activity. We also suggest the possibility that the exogenous NO evolved in cigarette smoke enables feedback inhibition of NOS activity or other possibility that it attenuates the toxicity of endotoxin LPS in vivo by unknown mechanisms, which should be further studied.

• Environmental Analysis Health and Toxicology
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• v.29
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• pp.10.1-10.6
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• 2014

Objectives Cigarette smoking had been recorded as the main cause of impaired endothelium-dependent vasodilation in smokers by reducing nitric oxide (NO), a production of endothelial nitric oxide synthase (eNOS). However, the mechanism of NO impairment via eNOS activity is unclear until now. In this study, cell passage is suggested to be a relevant factor to eNOS expression under cigarette smoking stress. Methods Bovine aortic endothelial cells (BAECs) were chosen as the research subject with passages ranking from 6 to 9 (6P to 9P). After exposure of cigarette smoking extract (CSE) solution, MTT assay and Western blot method were performed to check the cell viability as well as eNOS protein concentration. In these experiments, four concentrations of CSE at 0.5, 1, 2, and 4% were selected for treatment. Results Our results showed that cells almost died at 4% of CSE. Besides, eNOS protein mass had a linear decrease under the increase of CSE concentration. In addition, the effect of CSE on eNOS expression was dissimilar between different passages. Conclusions This study indicated that CSE had effect on both cell viability and eNOS expression. Besides, a reduction in protein mass was matched with the decrease of cell viability due to CSE tress. Last but not least, the response of eNOS protein to different concentration of CSE at different passages was disparate, making the hypothesis about cell passage related inhibition of eNOS caused by CSE solution.

• Biomolecules & Therapeutics
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• v.22 no.5
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• pp.390-399
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• 2014

Chalcones (1,3-diaryl-2-propen-1-ones), a flavonoid subfamily, are widely known for their anti-inflammatory properties. Propenone moiety in chalcones is known to play an important role in generating biological responses by chalcones. In the present study, we synthesized chalcone derivatives structurally modified in propenone moiety and examined inhibitory effect on nitric oxide (NO) production and its potential mechanisms. Among the chalcone derivatives used for this study, TI-I-174 (3-(2-Hydroxyphenyl)-1-(thiophen-3-yl)prop-2-en-1-one) most potently inhibited lipopolysaccharide (LPS)-stimulated nitrite production in RAW 264.7 macrophages. TI-I-174 treatment also markedly inhibited inducible nitric oxide synthase (iNOS) expression. However, TI-I-174 did not significantly affect production of IL-6, cyclooxygenase-2 (COX-2) and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), implying that TI-I-174 inhibits production of inflammatory mediators in a selective manner. Treatment of macrophages with TI-I-174 significantly inhibited transcriptional activity of activator protein-1 (AP-1) as determined by luciferase reporter gene assay, whereas nuclear factor-${\kappa}B$ (NF-${\kappa}B$) activity was not affected by TI-I-1744. In addition, TI-I-174 significantly inhibited activation of c-Jun-N-Terminal kinase (JNK) without affecting ERK1/2 and p38MAPK, indicating that down-regulation of iNOS gene expression by TI-I-174 is mainly attributed by blockade of JNK/AP-1 activation. We also demonstrated that TI-I-174 treatment led to an increase in heme oxygenase-1 (HO-1) expression both at mRNA and protein level. Transfection of siRNA targeting HO-1 reversed TI-I-174-mediated inhibition of nitrite production. Taken together, these results indicate that TI-I-174 suppresses NO production in LPS-stimulated RAW 264.7 macrophages via induction of HO-1 and blockade of AP-1 activation.

• Archives of Pharmacal Research
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• v.26 no.10
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• pp.832-839
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• 2003

Activated macrophages express inducible isoforms of nitric oxide synthase (iNOS) and cyclooxygenase (COX-2), and produce excessive amounts of nitric oxide (NO) and prostaglandin E$_2$ (PGE$_2$), which play key roles in the processes of inflammation and carcinogenesis. The root of Paeonia lactiflora Pall., and the root cortex of Paeonia suffruticosa Andr., are important Chinese crude drugs used in many traditional prescriptions. 1,2,3,4,6-penta-O-galloyl-$\beta$-D-glucose (PGG) is a major bioactive constituent of both crude drugs. PGG has been shown to possess potent anti-oxidant, anti-mutagenic, anti-proliferative and anti-invasive effects. In this study, we examined the inhibitory effects of 1,2,3,4,6-penta-O-galloyl-$\beta$-D-glucose (PGG) isolated from the root of Paeonia lactiflora Pall. on the COX-2 and iNOS activity in LPS-activated Raw 264.7 cells, COX-1 in HEL cells. To investigate the structure-activity relationships of gallate and gallic acid for the inhibition of iNOS and COX-2 activity, we also examined (-)-epigallocatechin gallate (EGCG), gallic acid, and gallacetophenone. The results of the present study indicated that PGG, EGCG, and gallacetophenone treatment except gallic acid significantly inhibited LPS-induced NO production in LPS-activated macrophages. All of the four compounds significantly inhibited COX-2 activity in LPS-activated macrophages. Among the four compounds examined, PGG revealed the most potent in both iNOS ($IC_{50}$ = 18 $\mu\textrm{g}/mL$) and COX-2 inhibitory activity (PGE$_2$: $IC_{50}$ = 8 $\mu\textrm{g}/mL$ and PGD$_2$: $IC_{50}$ = 12 $\mu\textrm{g}/mL$), respectively. Although further studies are needed to elucidate the molecular mechanisms and structure-activity relationship by which PGG exerts its inhibitory actions, our results suggest that PGG might be a candidate for developing anti-inflammatory and cancer chemopreventive agents.

• Proceedings of the SCSK Conference
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• 2003.09a
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• pp.601-610
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• 2003

Biotin is a water-soluble vitamin used as a skin conditioning agent and promotes the formation of intercellular lipid layers through increased lipid synthesis, which improves the skin's natural barrier function. The anti-inflammatory effects of biotin have been investigated using in vitro assay models, such as MTT assay, measurements of concentrations of nitric oxide(NO), prostaglandin E2(PGE$_2$), and inhibition rate of 5-lipoxygenase(5-LOX). In comparison with biotin, other plant extracts were tested at the same time which were kudzu vine extract, sage extract, paeonia extract, and dipotassium glycyrrhetinate. Nitric oxide is a signal molecule with functions such as neurotransmission, local vascular relaxation, and anti-inflammation in many physiological and pathological processes. NO can cause apoptosis and necrosis of target cells such as keratinocytes and is generated from L-arginine by nitric oxide synthase (NOS). Prostanoids, including prostaglandins and thromboxanes, are generated by the phospholipase $A_2$/cyclooxygenase(COX) pathway, and leukotrienes are generated by the 5-lipoxygenase pathway from arachidonic acid. Prostaglandin E2 recently have been shown to be beneficial in the resolution of tissue injury and inflammation, also has been implicated as an immunosuppressive agent and plasma levels of PGE$_2$ are elevated in patients sustaining thermal injury. Lipoxygenase metabolites from arachidonic acid have been implicated in inflammation, anti-inflammatory activity of the raw materials was evaluated in vitro by the offered inhibition of lipoxygenase.

• Korean Journal of Pharmacognosy
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• v.30 no.2
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• pp.99-104
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• 1999

During the screening for inhibitors of nitric oxide production in LPS-activated macrophage, RAW 264.7 cells. Five coumarins were isolated from chloroform extract of the root of Peucedanum japonicum. They were identified as praeruptorin A (1), xanthotoxin (2), psoralen (3), isopimpinellin (4), bergapten (5) on the basis of spectroscopic methods. The $IC_{50}$ values for nitrite production by activated macrophages were about $1.5\;{\mu}g/ml$ (1), $0.3\;{\mu}g/ml$ (2), $1.0\;{\mu}g/ml$ (3), $25\;{\mu}g/ml$ (4), $25\;{\mu}g/ml$ (5), respectively. However, the inducible nitric oxide synthase (iNOS) was not inhibited by treatment with these compounds. Their inhibitory effect on nitric oxide production was resulted from the supperssion of iNOS expression.

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