• 생약학회지
• /
• 제42권4호
• /
• pp.348-353
• /
• 2011

The aim of the present study is to investigate the cytokine production inhibitory effect of a Dictamni Radicis Cortex (DRC). DRC has been commonly used as important medicinal herb in China and it used to control eczema, atopic dermatitis, fever and inflammatory diseases. Inflammation, such as a bacterial infection in vivo metabolites, such as external stimuli or internal stimuli to the defense mechanisms of the biological tissue a variety of intracellular regulatory factors deulin inflammatory TNF-${\alpha}$, IL-$1{\beta}$, IL-6, IL-8, such as proinflammatory cytokines, prostagrandin, lysosomal enzyme, free radicals are involved in a variety of mediators. The present study was designed to determine the effect of the DRC on proinflammatory factors such as NO, iNOS expression and TNF-${\alpha}$, IL-$1{\beta}$, IL-6 in lipopolysaccharide (LPS) - stimulated RAW264.7 cells. The cell toxicity was determined by MTS assay. To evaluate of anti-inflammatory effect of DRC, amount of NO was measured using the NO detection kit and the iNOS expression was measured by reverse transcriptase polymerase chain reaction (RT-PCR). And proinflammatory cytokines were measured by ELISA kit. As a result, the DRC reduced NO, iNOS expression and TNF-${\alpha}$, IL-$1{\beta}$, IL-6 production without cytotoxicity. Our results suggest that the DRC may have an anti-inflammatory property through suppressing inflammatory mediator productions.

• Natural Product Sciences
• /
• 제16권4호
• /
• pp.265-270
• /
• 2010

The methanol extract of Zanthoxylum rhetsa (MZRR) were evaluated for its ability to suppress the formation of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. MZRR presented an inhibition of LPS-induced production of nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) in RAW 264.7 macrophages. Western blotting and RT-PCR analyses demonstrated that MZRR significantly inhibited the protein and mRNA expressions of iNOS and COX-2 in LPS-activated macrophages in a dose-dependent manner. LPS-induced COX-2, iNOS, and nuclear factor kappa beta (NF-${\kappa}B$) activity were also decreased in the presence of MZRR. The production of tumor necrosis factor-$\alpha$ (TNF-$\alpha$), the mRNA expression levels of pro-inflammatory cytokines, including TNF-$\alpha$ and IL-$1{\beta}$, were reduced after MZRR administration in a dose dependent-manner. These results suggest that the MZRR extract involved in the inhibition of iNOS and COX-2 via the NF-${\kappa}B$ pathway, revealing a partial molecular basis for anti-inflammatory properties of the MZRR extract.

• IMMUNE NETWORK
• /
• 제9권5호
• /
• pp.192-202
• /
• 2009

Background: Little information is available the role of Nitric Oxide (NO) in host defenses during human tuberculosis (TB) infection. We investigated the modulating factor(s) affecting NO synthase (iNOS) induction in human macrophages. Methods: Both iNOS mRNA and protein that regulate the growth of mycobacteria were determined using reverase transcriptase-polymerase chain reaction and western blot analysis. The upstream signaling pathways were further investigated using iNOS specific inhibitors. Results: Here we show that combined treatment with 1,25-dihydroxyvitamin D3 (1,25-D3) and Interferon (IFN)-${\gamma}$ synergistically enhanced NO synthesis and iNOS expression induced by Mycobacterium tuberculosis (MTB) or by its purified protein derivatives in human monocyte-derived macrophages. Both the nuclear factor-${\kappa}B$ and MEK1-ERK1/2 pathways were indispensable in the induction of iNOS expression, as shown in toll like receptor 2 stimulation. Further, the combined treatment with 1,25-D3 and IFN-${\gamma}$ was more potent than either agent alone in the inhibition of intracellular MTB growth. Notably, this enhanced effect was not explained by increased expression of cathelicidin, a known antimycobacterial effector of 1,25-D3. Conclusion: These data support a key role of NO in host defenses against TB and identify novel modulating factors for iNOS induction in human macrophages.

• The Korean Journal of Physiology and Pharmacology
• /
• 제14권6호
• /
• pp.353-358
• /
• 2010

This study demonstrates the ability of magnolol, a hydroxylated biphenyl compound isolated from Magnolia officinalis, to inhibit LPS-induced expression of iNOS gene and activation of NF-${\kappa}B$/Rel in RAW 264.7 cells. Immunohisto-chemical staining of iNOS and Western blot analysis showed magnolol to inhibit iNOS gene expression. Reporter gene assay and electrophoretic mobility shift assay showed that magnolol inhibited NF-${\kappa}B$/Rel transcriptional activation and DNA binding, respectively. Since p38 is important in the regulation of iNOS gene expression, we investigated the possibility that magnolol to target p38 for its anti-inflammatory effects. A molecular modeling study proposed a binding position for magnolol that targets the ATP binding site of p38 kinase (3GC7). Direct interaction of magnolol and p38 was further confirmed by pull down assay using magnolol conjugated to Sepharose 4B beads. The specific p38 inhibitor SB203580 abrogated the LPS-induced NF-${\kappa}B$/Rel activation, whereas the selective MEK-1 inhibitor PD98059 did not affect the NF-${\kappa}B$/Rel. Collectively, the results of the series of experiments indicate that magnolol inhibits iNOS gene expression by blocking NF-${\kappa}B$/Rel and p38 kinase signaling.

• BMB Reports
• /
• 제34권4호
• /
• pp.322-328
• /
• 2001

Excision and amplification of pre-determined, large genomic segments (taken directly from the genome of a natural host, which provides an alternative to conventional cloning in foreign vectors and hosts) was explored in human cells. In this approach, we devised a procedure for excising a large segment of human genomic DNA, the iNOS gene, by using the Cre/loxP system of bacteriophage P1 and amplifying the excised circles with the EBNA-1/oriP system of the Epstein-Barr virus. Two loxP sequences, each of which serves as a recognition site for recombinase Cre, were integrated unidirectionally into the 5'-UTR and 3'-UTR regions of the iNOS gene, together with an oriP sequence for conditional replication. The traps-acting genes cre and EBNA-1, which were under the control of a tetracycline responsive $P_{hcmv^*-1}$ promoter, were also inserted into the 5'-UTR and 3'-UTR regions of the iNOS gene, respectively, by homologous recombination. The strain carrying the inserted elements was stably maintained until the excision and amplification functions were triggered by the induction of cre and EBNA-1. Upon induction by doxycycline, Cre excised the iNOS gene that was flanked by two ZoxP sites and circularized it. The circularized iNOS gene was then amplified by the EBNA-1/oriP-system. With this procedure, approximately a 45.8-kb iNOS genomic fragment of human chromosome 17 was excised and successfully amplified in human cells. Our procedure can be used effectively for the sequencing of unclonable genes, the functional analysis of unknown genes, and gene therapy.

• The Korean Journal of Physiology and Pharmacology
• /
• 제5권5호
• /
• pp.443-449
• /
• 2001

Previously we reported that THI 52 inhibits tumor necrosis factor $(TNF)-{\alpha}$ mRNA expression in mouse peritoneal macrophages exposed to LPS plus $IFN-{\gamma}.$ In the present study, the effects of THI 52 on vascular reactivity ex vivo, and iNOS protein expression (rat lung) were investigated in LPS-treated rats. Treatment of THI 52 concentration-dependently reduced not only serum nitrite production but also the expression of iNOS protein in rat lung tissues. Thoracic aorta taken from LPS injected rat for 8 h ex vivo resulted in suppression of vasoconstrictor effects to phenylephrine (PE), which was restored by THI 52 (20 mg/kg) 30 min prior to LPS. When measured iNOS activity, treatment of THI 52 concentration-dependently reduced the enzyme activity in RAW 264.7 cells activated with LPS plus $IFN-{\gamma}.$ Likewise, iNOS activity was significantly reduced in lung tissues taken those rats that were injected THI 52 prior to LPS injection compared with LPS injection alone. These results strongly suggest that THI 52 can suppress iNOS gene expression induced by LPS, and restore the vascular contractility to PE. Thus, THI 52, a new synthetic isoquinoline alkaloid, may be beneficial in inflammatory disorders where production of NO is excessed by iNOS expression.

• 동의생리병리학회지
• /
• 제24권6호
• /
• pp.976-982
• /
• 2010

We studied to know the anti-inflammation effect on water extracts of Lophatheri Herba which was growing in every places in our country. We objected free radical scanvenger effect and nitrite eliminate effect of the Lophatheri Herba water extracts, and the cell viabillity, the effects of Lophatheri Herba water extracts on NO production, iNOS synthesis induced by LPS. Free radical scavenger effects were $27.91{\pm}0.12%$, $38.96{\pm}0.10%$, $46.22{\pm}0.15%$ depend on 0.5, 1.0, 2.0 mg/ml each dose of Lophatheri Herba water extracts. Nitrite eliminate effects were $9.86{\pm}0.3%$, $80.61{\pm}0.23%$, $97.62{\pm}0.56%$ in 0.1, 1.0, 2.0 mg/ml Lophatheri Herba water extracts on pH 1.2. NO production and iNOS synthesis induced by LPS were reduced in RAW 264.7 cell by Lophatheri Herba water extracts. As the above results, Lophatheri Herba water extracts have anti-inflammation effects via NO production decrease, iNOS synthesis decrease mechanism. So Lophatheri Herba water extracts will be used as the protection or treatment in chronic inflammation desease like a asthma, stomatitis etc.

• Biomolecules & Therapeutics
• /
• 제32권4호
• /
• pp.467-473
• /
• 2024

In this study, we investigated the potential protective effects of (+)-afzelechin (AZC), a natural compound that is derived from Bergenia ligulata, on lipopolysaccharide (LPS)-induced inflammatory responses. AZC is known to have antioxidant, anticancer, antimicrobial, and cardiovascular protective properties. However, knowledge regarding the therapeutic potential of AZC against LPS-induced inflammatory responses is limited. Thus, we investigated the protective attributes of AZC against inflammatory damage caused by LPS exposure. We examined the effects of AZC on heme oxygenase (HO)-1, cyclooxygenase (COX)-2, and inducible nitric oxide synthase (iNOS) in LPS-activated human umbilical vein endothelial cells (HUVECs). In addition, the effects of AZC on the expression of iNOS, tumor necrosis factor (TNF)-α, and interleukin (IL)-1β were analyzed in the lung tissues of LPS-injected mice. Data revealed that AZC promoted the production of HO-1, inhibited the interaction between luciferase and nuclear factor (NF)-κB, and reduced the levels of COX-2/PGE2 and iNOS/NO, thereby leading to a decrease in the signal transducer and activator of transcription (STAT)-1 phosphorylation. Moreover, AZC facilitated the nuclear translocation of Nrf2, increased the binding activity between Nrf2 and the antioxidant response elements (AREs), and lowered the expression of IL-1β in the LPS-treated HUVECs. In the animal model, AZC significantly reduced the expression of iNOS in the lung tissue structure and the TNF-α level in the bronchoalveolar lavage fluid. These findings demonstrate that AZC possesses anti-inflammatory properties that regulate iNOS through the inhibition of both NF-κB expression and p-STAT-1. Consequently, AZC has potential as a future candidate for the development of new clinical substances for the treatment of pathological inflammation.

• 한국과학교육학회지
• /
• 제28권7호
• /
• pp.759-767
• /
• 2008

This article arose from the previous studies, which suggested a synthetic list for the nature of science (NOS), discussed the relationship between the NOS and scientific inquiry and the development of the NOS in the context of scientific inquiry. In this article, for teaching scientific inquiry through the NOS, I proposed three teaching models - reflection, interaction, and the direct model -. Within these teaching models, understanding the NOS is viewed as a prerequisite condition for the improved performance of scientific inquiry. In the reflection model, the NOS is embedded and reflected in scientific inquiry without explicit introduction or direct explanation of the NOS. In the interaction model, concrete interaction between scientific inquiry and the NOS is encouraged during the process of scientific inquiry. In the direct model, subsequent to directly comprehending the NOS at the first stage of activity, students conduct scientific inquiry based on their understanding of the NOS. The intention of this present article is to facilitate the use of these models to develop teaching materials for more authentic scientific inquiry.

• 대한의생명과학회지
• /
• 제25권3호
• /
• pp.267-274
• /
• 2019

Toll-like receptors (TLRs) are one of the families of pattern recognition receptors (PRR) to recognize pathogen-associated molecular patterns (PAMPs). PAMPs stimulate TLRs to initiate specific immunoactivity. The activation of TLRs signaling leads to the expression of pro-inflammatory gene products such as cytokines and inducible nitric oxide synthase (iNOS). To evaluate the therapeutic potential of dehydrocostus lactone (DHL), which is a natural sesquiterpene lactone derived from various medicinal plants, iNOS expression induced by LPS (TLR4 agonist), MALP-2 (TLR2 and TLR6 agonist), or Poly[I:C] (TLR3 agonist) were examined. DHL suppressed the iNOS expression induced by LPS, MALP-2, or Poly[I:C]. DHL also inhibited nitrite production induced by LPS, MALP-2, or Poly[I:C]. These results suggest that DHL can modulate TLRs signaling pathways resulting in anti-inflammatory effect.