• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.1
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• pp.63-68
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• 2014

The fruit of Tribulus terrestris L. (Zygophyllaceae) is an important source of traditional Korean and Chinese medicines. In this study, NNMBS223, consisting of the ethanol extract of T. terrestris, showed potent anti-inflammatory activities in RAW264.7 macrophages. We investigated the effect of NNMBS223 in suppressing the protein expression of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2 and production of iNOS-derived nitric oxide (NO), COX-2-derived prostaglandin E2 (PGE2) in lipopolysaccharide (LPS)-stimulated macrophages. In addition, NNMBS223 induced expression of heme oxygenase (HO)-1 through nuclear translocation of nuclear factor E2-related factor 2 (Nrf2) in macrophages. The effects of NNMBS223 on LPS-induced production of NO and PGE2 were partially reversed by the HO activity inhibitor tin protoporphyrin (SnPP). These findings suggest that Nrf2-dependent increases in expression of HO-1 induced by NNMBS223 conferred anti-inflammatory activities in LPS stimulated RAW264.7 macrophages.

• The Korean Journal of Physiology and Pharmacology
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• v.26 no.2
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• pp.95-111
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• 2022

Chronic obstructive pulmonary disease (COPD) is an important healthcare problem worldwide. Often, glucocorticoid (GC) resistance develops during COPD treatment. As a classic hypoglycemic drug, metformin (MET) can be used as a treatment strategy for COPD due to its anti-inflammatory and antioxidant effects, but its specific mechanism of action is not known. We aimed to clarify the role of MET on COPD and cigarette smoke extract (CSE)-induced GC resistance. Through establishment of a COPD model in rats, we found that MET could improve lung function, reduce pathological injury, as well as reduce the level of inflammation and oxidative stress in COPD, and upregulate expression of nuclear factor E2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), multidrug resistance protein 1 (MRP1), and histone deacetylase 2 (HDAC2). By establishing a model of GC resistance in human bronchial epithelial cells stimulated by CSE, we found that MET reduced secretion of interleukin-8, and could upregulate expression of Nrf2, HO-1, MRP1, and HDAC2. MET could also increase the inhibition of MRP1 efflux by MK571 significantly, and increase expression of HDAC2 mRNA and protein. In conclusion, MET may upregulate MRP1 expression by activating the Nrf2/HO-1 signaling pathway, and then regulate expression of HDAC2 protein to reduce GC resistance.

• Food Science and Biotechnology
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• v.17 no.2
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• pp.367-372
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• 2008

Cellular protection against carcinogens could be achieved by the induction of phase 2 detoxifying and antioxidant enzymes such as glutathione S-transferase (GST), NAD(P)H:quinone oxidoreductase 1 (NQO1) and heme oxygenase 1 (HO1). Nuclear transcription factor E2-related factor 2 (Nrf2) binds to antioxidant response element (ARE) in the promoter region of these genes and the resulting transactivation occurs. In the present study the effect of gujeolcho (Chrysanthemum zawadskii) roots on the Nrf2-ARE pathway were investigated. C. zawadskii root extract was fractionated with a series of organic solvents and their ability to induce Nrf2-ARE pathway was examined. We separated the most potent dichloromethane (DCM) fraction into 12 sub-fractions and found several sub-fractions with strong effects on the Nrf2-ARE pathway. Fraction 4 strongly induced the ARE-reporter gene activity as well as Nrf2 expression. Sitosterol was isolated as a major compound in fraction 4 although its activity was not as potent as its mother fraction. These results indicate that C. zawadskii roots might be used as a potential natural chemopreventive source.

• Journal of Life Science
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• v.23 no.6
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• pp.736-742
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• 2013

Achyranthoside E dimethyl ester (AEDE) is an oleanolic acid glycoside from Achyranthes japonica. In this study, we investigated the effects of AEDE on nitric oxide (NO) production and underlying molecular mechanisms in lipopolysaccharide (LPS)-stimulated macrophages. AEDE inhibited LPS-induced NO secretion as well as inducible NO synthase (iNOS) expression, without affecting cell viability. Further study demonstrated that AEDE induced heme oxygenase-1 (HO-1) gene expression. In addition, the inhibitory effects of AEDE on iNOS expression were abrogated by small interfering RNA-mediated knock-down of HO-1. Moreover, AEDE induced nuclear translocation of nuclear factor E2-related factor 2 (Nrf2), a transcription factor that regulates HO-1 expression. AEDE-induced expression of HO-1 was inhibited by inhibitors of phosphatidylinositol 3-kinase (PI-3K) and extracellular signal regulated kinase (ERK1/2). AEDE phosphorylated Akt and ERK1/2 as well. Therefore, these results suggest that AEDE suppresses the production of pro-inflammatory mediator such as NO by inducing HO-1 expression via PI-3K/Akt/ERK-Nrf2 signaling. These findings provide the scientific rationale for anti-inflammatory therapeutic use of AEDE.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.241.3-242
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• 2002

Expression of phase II detoxifying genes is regulated by NF-E2-related factor 2 (Nrf2)-mediated antioxidant response element (ARE) activation. Phosphatidylinositol 3-kinase (PI3-kinase) plays an essential role in ARE-mediated rGSTA2 induction by oxidative stress and controls microfilaments and translocation of actin-associated proteins. This study was designed to investigate the P13-kinase-mediated nuclear translocation of Nrf2 and the interaction of Nrf2 with actin. (omitted)

• Biomedical Science Letters
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• v.29 no.2
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• pp.58-65
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• 2023

Pu-erh tea, a popular and traditional Chinese tea, possesses various health-promoting effects, including inhibiting tumor cell progression and preventing type II diabetes and neurodegenerative disorders. However, the precise anti-inflammatory mechanisms are not well understood. In present study, we elucidated the anti-inflammatory mechanism of Pu-erh tea in lipopolysaccharide (LPS)-activated RAW264.7 cells. We explored the effects of Pu-erh tea on the levels of inflammatory-related genes, including inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2 and prostaglandin E₂ (PGE₂) in LPS-activated RAW264.7 cells. Moreover, we investigated its regulatory effects on nuclear factor-kappa B (NF)-κB and hypoxia-inducible-factor (HIF)-1α activation. The findings of this study demonstrated that Pu-erh tea inhibited the LPS-increased inflammatory cytokines and PGE₂ release, as well as COX-2 and iNOS expression. Moreover, we confirmed that the anti-inflammatory mechanism of Pu-erh tea occurs via the inhibition of NF-κB and HIF-1α activation. Conclusively, these findings provide experimental evidence that Pu-erh tea may be useful candidate in the treatment of inflammatory-related diseases.

• Korean Journal of Pharmacognosy
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• v.47 no.1
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• pp.55-61
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• 2016

Antioxidant effects and nuclear factor E2-related factor-2 (Nrf-2) signal pathway of methanol extract and 4 fractions [n-hexane, methylene chloride, ethyl acetate (EtOAc), and n-butanol fractions] from Petasites japonicus were investigated. The EtOAc fraction showed highest polyphenol and flavonoid contents among other fractions. In addition, EtOAc fraction showed stronger scavenging activity against superoxide anion radical than other fractions. Furthermore, we investigated antioxidants effects of the EtOAc fraction under cellular system using $LLC-PK_1$ cells. The EtOAc fraction dose-dependently increased the antioxidant protein expressions of heme oxygenase 1 (HO-1) and thioredoxin reductase 1 (TrxR1) known to be involved in oxidative stress, through activation of Nrf-2. The treatment of EtOAc fraction ($100{\mu}g/mL$) led to the elevation of the high expression of Nrf-2-dependent factor such as HO-1 and TrxR1. These results indicated that the EtOAc fraction of P. japonicus showed high antioxidant activity by regulation of Nrf-2 signaling pathway.

• Journal of Life Science
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• v.25 no.9
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• pp.976-983
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• 2015

Achyranthoside C dimethyl ester (ACDE) is an oleanolic acid glycoside from Achyranthes japonica which has been used in traditional medicine for the treatment of edema and arthritis. In this study, we investigated the anti-inflammatory effects of ACDE in RAW264.7 macrophages. ACDE significantly induced heme oxygenase-1 (HO-1) gene expression in RAW264.7 cells, while ACDE improved LPS-induced toxicity of cells. And ACDE induced nuclear translocation of nuclear factor E2-related factor 2 (Nrf2), a transcription factor that regulates HO-1 expression. Further study demonstrated that ACDE-induced expression of HO-1 was inhibited by inhibitors of phosphatidylinositol 3-kinase (PI-3K) (LY294002), c-Jun kinase (JNK) (SP600125), extracellular signal regulated kinase (ERK) (PD98059) and p38 kinase (SB203580). Moreover, ACDE phosphorylated Akt, JNK, ERK, and p38 MAPK. In addition, ACDE inhibited LPS-induced NO secretion as well as inducible NO synthase (iNOS) expression in a dose-dependent manner. The inhibitory effects of ACDE on iNOS expression were abrogated by small interfering RNA (siRNA)-mediated knock-down of HO-1. Therefore, these results suggest that ACDE suppresses the production of pro-inflammatory mediator such as NO by inducing HO-1 expression via PI-3K/Akt/MAPK-Nrf2 signaling pathway. These findings could help us to understand the active principle included in the roots of A. japonica and the molecular mechanisms underlying anti-inflammatory action of ACDE.

• The Korean Journal of Physiology and Pharmacology
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• v.24 no.5
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• pp.373-384
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• 2020

Paeonol, quercetin, β-sitosterol, and gallic acid extracted from Moutan Cortex had been reported to possess anti-oxidative, anti-inflammatory, and anti-tumor activities. This work aimed to illustrate the potential anti-oxidative mechanism of monomers in human liver hepatocellular carcinoma (HepG2) cells-induced by hydrogen peroxide (H₂O₂) and to evaluate whether the hepatoprotective effect of monomers was independence or synergy in mice stimulated by carbon tetrachloride (CCl₄). Monomers protected against oxidative stress in HepG2 cells in a dose-response manner by inhibiting the generation of reactive oxygen species, increasing total antioxidant capacity, catalase and superoxide dismutase (SOD) activities, and activating the antioxidative pathway of nuclear factor E2-related factor 2/Kelch-like ECH-associated protein 1 (Nrf2/Keap1) signaling pathway. We found that the in vitro antioxidant capacities of paeonol and quercetin were better than those of β-sitosterol and gallic acid. Furthermore, paeonol apparently diminished the levels of alanine transaminase and aspartate aminotransferase, augmented the contents of glutathione and SOD, promoted the expressions of Nrf2 and heme oxygenase-1 proteins in mice stimulated by CCl₄. In HepG2 cells, paeonol, quercetin, β-sitosterol, and gallic acid play a defensive role against H₂O₂-induced oxidative stress through activating Nrf2/Keap1 pathway, indicating that these monomers have anti-oxidative properties. Totally, paeonol and quercetin exerted anti-oxidative and hepatoprotective effects, which is independent rather than synergy.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2004.11a
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• pp.157-157
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• 2004