• BMB Reports
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• v.46 no.8
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• pp.410-415
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• 2013

Adhesion molecules such as ICAM-1 are important in the infiltration of leukocytes into the site of inflammation. In this study, we investigated the inhibitory effects of curcumin on ICAM-1 expression and monocyte adhesiveness as well as its underlying action mechanism in the TNF-${\alpha}$-stimulated keratinocytes. Curcumin induced expression of heme oxygenase-1 (HO-1) in the human keratinocyte cell line HaCaT. In addition, curcumin induced Nrf2 activation in dose- and time-dependent manners in the HaCaT cells. Curcumin suppressed TNF-${\alpha}$-induced ICAM-1 expression and subsequent monocyte adhesion, which were reversed by the addition of tin protoporphyrin IX (SnPP), a specific inhibitor of HO-1, or HO-1 knockdown using siRNA. Furthermore, Nrf2 knockdown using siRNA reversed the inhibitory effect of curcumin on the TNF-${\alpha}$-induced ICAM-1 expression and adhesion of monocytes to keratinocytes. These results suggest that curcumin may exert its anti-inflammatory activity by suppressing the TNF-${\alpha}$-induced ICAM-1 expression and subsequent monocyte adhesion via expression of HO-1 in the keratinocytes.

• Journal of Periodontal and Implant Science
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• v.43 no.4
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• pp.191-197
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• 2013

Purpose: Nitric oxide (NO) is a short-lived bioactive molecule that is known to play an important role in the pathogenesis of periodontal disease. In the current study, we investigated the effect of the flavonoid quercetin on the production of NO in murine macrophages activated with lipopolysaccharide (LPS) from Prevotella intermedia, a pathogen related to inflammatory periodontal disease, and tried to elucidate the underlying mechanisms of action. Methods: LPS was isolated from P. intermedia ATCC 25611 cells by the standard hot phenol-water method. The concentration of NO in cell culture supernatants was determined by measuring the accumulation of nitrite. Inducible NO synthase (iNOS) and heme oxygenase-1 (HO-1) protein expression, phosphorylation of c-Jun N-terminal kinase (JNK) and p38, inhibitory ${\kappa}B$ $(I{\kappa}B)-{\alpha}$ degradation, and signal transducer and activator of transcription 1 (STAT1) phosphorylation were analyzed via immunoblotting. Results: Quercetin significantly attenuated iNOS-derived NO production in RAW246.7 cells activated by P. intermedia LPS. In addition, quercetin induced HO-1 protein expression in cells activated with P. intermedia LPS. Tin protoporphyrin IX (SnPP), a competitive inhibitor of HO-1, abolished the inhibitory effect of quercetin on LPS-induced NO production. Quercetin did not affect the phosphorylation of JNK and p38 induced by P. intermedia LPS. The degradation of $I{\kappa}B-{\alpha}$ induced by P. intermedia LPS was inhibited when the cells were treated with quercetin. Quercetin also inhibited LPS-induced STAT1 signaling. Conclusions: Quercetin significantly inhibits iNOS-derived NO production in murine macrophages activated by P. intermedia LPS via anti-inflammatory HO-1 induction and inhibition of the nuclear factor-${\kappa}B$ and STAT1 signaling pathways. Our study suggests that quercetin may contribute to the modulation of host-destructive responses mediated by NO and appears to have potential as a novel therapeutic agent for treating inflammatory periodontal disease.

• Biomolecules & Therapeutics
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• v.19 no.4
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• pp.419-424
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• 2011

Galla Rhois and its components are known to possess anti-infl ammatory properties. In the present study, we prepared equilibrium mixture of ethyl m-digallate and ethyl p-digallate isomers (EDG) from Galla Rhois and examined its effect on nitric oxide (NO) production in murine macrophage cell line. Treatment of RAW264.7 macrophages with EDG signifi cantly inhibited NO production and inducible nitric oxide synthase (iNOS) expression stimulated by LPS, as assessed by Western blot and quantitative RT-PCR analyses. We also demonstrated that EDG treatment led to an increase in heme oxygenase-1 (HO-1) mRNA and protein expression. EDG treatment also enhanced expression level of nuclear factor-erythroid 2-related factor 2 (Nrf2) in nucleus, which is critical for transcriptional induction of HO-1. Treatment with SnPP (tin protoporphyrin IX), a selective HO-1 inhibitor, reversed EDG-mediated inhibition of nitrite production, suggesting that HO-1 plays an important role in the suppression of NO production by EDG. Taken together, these results indicate that EDG isolated from Galla Rhois suppresses LPS-stimulated NO production in RAW 264.7 macrophages via HO-1 induction.

• Molecules and Cells
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• v.37 no.3
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• pp.234-240
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• 2014

Cisplatin is one of the most potent chemotherapy agents. However, its use is limited due to its toxicity in normal tissues, including the kidney and ear. In particular, nephrotoxicity induced by cisplatin is closely associated with oxidative stress and inflammation. Heme oxygenase-1(HO-1), the rate-limiting enzyme in the heme metabolism, has been implicated in a various cellular processes, such as inflammatory injury and anti-oxidant/oxidant homeostasis. Capsaicin is reported to have therapeutic potential in cisplatin-induced renal failures. However, the mechanisms underlying its protective effects on cisplatin-induced nephrotoxicity remain largely unknown. Herein, we demonstrated that administration of capsaicin ameliorates cisplatin-induced renal dysfunction by assessing the levels of serum creatinine and blood urea nitrogen (BUN) as well as tissue histology. In addition, capsaicin treatment attenuates the expression of inflammatory mediators and oxidative stress markers for renal damage. We also found that capsaicin induces HO-1 expression in kidney tissues and HK-2 cells. Notably, the protective effects of capsaicin were completely abrogated by treatment with either the HO inhibitor ZnPP IX or HO-1 knockdown in HK-2 cells. These results suggest that capsaicin has protective effects against cisplatin-induced renal dysfunction through induction of HO-1 as well as inhibition oxidative stress and inflammation.

• The Korea Journal of Herbology
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• v.27 no.6
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• pp.55-61
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• 2012

Objectives : Allium Hookeri (AH) is a traditional herb to treat inflammatory diseases in India and Myanmar. Recently, AH cultivation was succeeded in South Korea. This study was performed to evaluate the anti-inflammatory effects of Korean AH in RAW264.7 cells, mouse macrophage cell line. Methods : To evaluate the anti-inflammatory effects of root of AH, we prepared the 70% ethanol extract, then we examined the productions of nitrite, and pro-inflammatory cytokines. To examine the nitrite, and cytokines, the RAW264.7 cells were treated with AH, then stimulated with lipopolysaccharide (LPS, 500 ng/ml) for 24 h. Then the cells were harvested for griess assay, ELISA and real-time reverse transcription polymerase chain reaction (RT-PCR). Also to detect the ability of AH to induce heme oxygenase-1 (HO-1), we examined the HO-1 expression using real time RT-PCR and western blot. Furthermore, we examined the mitogen activated-protein kinases (MAPKs) and nuclear factor kappa B (NF-${\kappa}B$) activation to find out the underlying mechanisms. Results : AH ethanol extract significantly inhibited the productions of nitrite and interleukin (IL)-$1{\beta}$. AH treatment increased the HO-1 expression dramatically at 1 h, then peaked at 3 h. When the HO-1 was inhibited by tin (Sn) protoporphryin-IX (SnPP), the anti-inflammatory action of AH was reversed. AH treatment inhibited the activation of p38, but not extracelluar signal-regulated kinase (ERK 1/2) and c-Jun $NH_2$-terminal kinase (JNK) and also the degradation of inhibitory kappa B a (Ik-$B{\alpha}$) in the LPS-stimulated RAW 264.7 cells. Conclusions : These data could suggest that AH exerts anti-inflammatory influences through up-regulation of HO-1 and deactivation of p38.

• The Korea Journal of Herbology
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• v.37 no.5
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• pp.83-88
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• 2022

Objectives : Jakyakgamcho-tang (JGT) has been traditionally used to treat muscular convulsion and pain in South Korea. According to recent studies, JGT has been reported to have anti-depression, anti-inflammation, anti-oxidative, anti-diabetics, anti-spasm and analgesic effects, but studies on its anti-neuroinflammatory and neuroprotective effect have not been deeply conducted. Thus, we investigated the anti-neuroinflammatory activity of JGT on lipopolysaccharide (LPS)-stimulated mouse microglia cells. Methods : To investigate the anti-neuroinflammatory effects of JGT on BV2 microglial cells, we examined the production of nitric oxide (NO) using griess assay, and mRNA expressions of pro-inflammatory cytokines such as interleukin (IL)-1𝛽, IL-6, and tumor necrosis factor (TNF)-𝛼 using real time RT-PCR. Furthermore, to determine the regulating mechanisms of JGT, we investigated the heme oxygenase (HO)-1 by real time RT-PCR. Results : Pre-treatment of JGT effectively decreased NO production in LPS-stimulated BV2 cells at concentrations without cytotoxicity. Additionally, JGT significantly suppressed the production of IL-1𝛽, IL-6, and TNF-𝛼 in LPS-stimulated BV2 cells. Furthermore, JGT activated the HO-1 expression, which is one of the immunomodulatory signaling molecules. And the abolishment of HO-1 by tin protoporphyrin IX (SnPP, the HO-1 inhibitor) reversed the anti- inflammatory activity of JGT in LPS-stimulated BV2 cells. Conclusions : Our results suggest that the JGT has anti-neuroinflammatory effect through the activation of HO-1 in LPS-stimulated BV2 cells. Thereby, JGT could expected to be used for the prevention and treatment of neurodegenerative disease related to neuroinflammation.

• The Korean Journal of Physiology and Pharmacology
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• v.11 no.2
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• pp.65-70
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• 2007

Chinese herb medicines have traditionally been used to treat or alleviate the symptom of various diseases. The rationale for use of certain herbs to certain disorder is now getting unveiled by modern technology. In the present study, we investigated whether herb mix extract(HMX), which is alleged to be useful for gastric ulcer, protects stomach from oxidative stress. Rats were allowed to normal diet with and without HMX (1, 5, 10 mg/kg) for 30 days. To induce gastric ulcer, ethanol (75%, 1.5 ml) or acidified aspirin (100 mg/kg in 0.2 N HCl) was administered by oral route in 24 h-fasted rats and examined the gastric ulceration(bleeding) by measuring the size 1 h after the treatment. Results indicated the area of gastric bleeding was significantly less in HMX fed rats than in normal diet fed ones, and it was dependent on the duration and amount of HMX. To investigate the underlying mechanism by which HMX protects stomach from oxidative stress, expression of enzymes like heme oxygenase (HO), cyclooxygenase (COX), and inducible nitric oxide (iNOS) were investigated in MKN-74 cells, where aspirin or H. pylori was introduced. The results were compared with RAW 264.7 cells to check if there's cell specificities exist. The expression of HO-1 but not COX-2, iNOS was significantly increased by HMX. Furthermore, HO-1 inhibitor, SnPP IX reduced the HO-1 activity and reversed the survival rate in HMX-treated MKN-74 cells. There's no difference between RAW 264.7 cells and MKN-74 cells. We, thus, concluded that HMX is beneficial for protection from oxidative injury, and induction of HO-1 by HMX in gastric cells is, at least, responsible for protection from oxidative stress such as ethanol, aspirin and possibly H. pylori infection.