• Natural Product Sciences
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• v.15 no.1
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• pp.32-36
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• 2009

Glutamate causes neurotoxicity through formation of reactive oxygen species and activation of mitogen-activated protein kinase (MAPK) pathways. MAPK phosphatase-1 (MKP-1) is one of the phosphatases responsible for dephosphorylation/deactivation of three MAPK families: the extracellular signal-regulated kinase-1/2 (ERK-1/2), the c-Jun N-terminal kinase-1/2 (JNK-1/2), and the p38 MAPK. In this report, the potential involvement of MKP-1 in neuroprotective effects of curcumin, the active ingredient of turmeric (Curcuma longa), was examined using HT22 cells. Glutamate caused cell death and activation of ERK-1/2 but not p38 MAPK or JNK-1/2. Blockage of ERK-1/2 by its inhibitor protected HT22 cells against glutamate-induced toxicity. Curcumin attenuated glutamate-induced cell death and ERK-1/2 activation. Interestingly, curcumin induced MKP-1 activation. In HT22 cells transiently transfected with small interfering RNA against MKP-1, curcumin failed to inhibit glutamate-induced ERK-1/2 activation and to protect HT22 cells from glutamate-induced toxicity. These results suggest that curcumin can attenuate glutamate-induced neurotoxicity by activating MKP-1 which acts as the negative regulator of ERK-1/2. This novel pathway may contribute to and explain at least one of the neuroprotective actions of curcumin.

• Journal of Society of Preventive Korean Medicine
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• v.22 no.1
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• pp.107-127
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• 2018

Objectives : The present study investigated the anti-obese and blood flow improvement activities of aqueous extracts of ginseng berry (GBe) on the mild diabetic obese mice as compared with metformin. Methods : After end of 56 days of continuous oral administrations of GBe 150, 100 and 50 mg/kg, or metformin 250 mg/kg, anti-obese and blood flow improvement effects - the changes of body weights, body and abdominal fat density by in live dual-energy x-ray absorptionmetry (DEXA), tail bleeding time, prothrombin time (PT), activated partial thromboplastin time (aPTT), serum total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL) and high density lipoprotein (HDL) levels, aorta and serum cyclic guanosine monophosphate (cGMP), nitric oxide (NO) and endothelin (ET)-1 levels, aorta phosphorylated PI3K (pPI3K), phosphorylated Akt (pAkt) and phosphorylated p38 MAPK (pp38 MAPK) levels were systemically analyzed. In addition, aorta vascular dilation and constriction related gene mRNA expressions - PI3K, Akt, eNOS, p38 MAPK and ET-1 were also analyzed by realtime RT-PCR. Results : The obesity and related blood flow impairment, induced by 84 days of continuous HFD supply, were significantly inhibited by 56 days of continuous oral treatment of GBe 150, 100 and 50mg/kg, dose-dependently, and they also dramatically normalized the changes of the aorta vascular dilation and constriction related gene mRNA expressions, also dose-dependently. Especially, GBe 150 mg/kg constantly showed favorable inhibitory activities against type II diabetes related obesity and vascular disorders through PI3K/Akt pathway and p38 MAPK mediated cGMP, NO and ET-1 expression modulatory activities, as comparable to those of metformin 250 mg/kg in HFD mice. Conclusion : By assessing the key parameters for anti-obese and blood flow improvement activities on the HFD-induced mild diabetic obese mice, the present work demonstrated that GBe 150, 100 and 50 mg/kg showed favorable anti-obese and blood flow improvement effects in HFD-induced type II diabetic mice, through PI3K/Akt pathway and p38 MAPK mediated cGMP, NO and ET-1 expression modulatory activities.

• Korean Journal of Clinical Laboratory Science
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• v.48 no.3
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• pp.188-195
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• 2016

Neutrophils and lymphocytes are essential inflammatory cells in the pathogenesis of allergy. In this study, we evaluated the role of house dust mite (HDM) in the interaction between allergic lymphocytes and neutrophils. The extract of Dermatophagoides pteronissinus (DP) showed a stronger anti-apoptotic impact on neutrophil apoptosis in the coculture of allergic neutrophils with allergic lymphocytes when compared with that in allergic neutrophils alone. DP increased IL-6, IL-8, MCP-1, and GM-CSF in allergic lymphocytes, and the increased cytokines were inhibited by rottlerin-an inhibitor of the protein kinase C (PKC) ${\delta}$, as well as by SB202190-a p38 MAPK inhibitor. DP activated p38 MAPK in a time-dependent manner. The activation of p38 MAPK was suppressed by PAR2i, which is a protease-activated receptor (PAR) 2 inhibitor, and rottlerin. Both aprotinin-a serine protease inhibitor-and E64-a cysteine protease inhibitor-were not effective on cytokine secretion of lymphocytes. These results, despite increased cytokines in allergic lymphocytes via DP, did not show any differences between asthma and allergic rhinitis. Molecules, including cytokines, released by DP in lymphocytes inhibited the migration of neutrophils. This finding may further elucidate the pathogenic mechanism of allergic diseases due to HDM.

• The Korea Journal of Herbology
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• v.22 no.2
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• pp.147-153
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• 2007

Objectives : Sophora flavescens (SF) is widely used in traditional herbal medicine in Korea and is well recognized for its anti-inflammatory effect. However, its effect on Tumornecrosis factor alpha (Tnf) production in BV2 microglial cell is not yet known. Methods : We investigated the effect of SF on the production and expression of Tnf, a well known inflammatory mediator, in lipopolysaccaride (LPS)-activated BV2 microglial cells. Results : The LPS-induced Tnf production was markedly reduced by treatment with SF (50 ${\mu}g/ml$). In reverse transcription polymerase chain reaction (RT-PCR) analysis, SF suppressed the LPS activated expression of Tnf mRNA. In addition, Western blot analysis confirmed that SF suppressed the expression of Tnf. Sophora flavescens also inhibited the LPS-induced phosphylation of extracellular signal-regulated kinases (ERK), which mediate the Tnfproduction signaling pathway whereas LPS-induced phosphylation of p38 mitogen activated protein kinase (p38 MAPK), and c-Jun NH2-terminal kinases (JNK) was not inhibited by SF, which implies that SF suppresses LPS-induced Tnf production via the ERK mediated pathway. Conclusion : Taken together, these findings indicated that SF inhibits LPS-induce Tnf production, and that this inhibitory effect is mediated via the ERK pathway.

• The Journal of Korean Medicine
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• v.29 no.4
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• pp.171-179
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• 2008

Objective: Bufonis Venenum is the traditional Korean medicine Chan Su, which is obtained from the skin and parotid venom gland of the toads. It has been used for myocardial diseases, inflammation diseases, pain relief, cancer and others. The main components of BV are cinobufotoxin, cinobufalin, bufalin and others. Of these, bufalin, the major active ingredient of BV, has been reported to induce apoptosis and to possess anti-tumor effects. There was no report of anti-tumor screening of BV on hepatic cancer and which signaling pathway can be involved. In order to examine the effect of BV on hepatic cancer and the related signaling pathway with BV-induced apoptosis, human Hep G2 cells were used. Methods: Analysis of apoptosis was confirmed by MTT assay. BV decreased cell viability in a dose and duration dependent manner. To observe which signaling molecules will be activated by BV, phosphorylation of MAPK (p38, ERK, JNK), caspase 8 and caspase 9 were examined by Western blot analysis. Results: The phosphorylation levels of p38 started to increase at 5 min after addition of 5 ${\mu}g$/ml of BV and sustained to increase until 48 hours. The phosphorylation levels of other MAPK (ERK and JNK), caspase 8 and caspase 9 increased in a time-dependent manner. These imply that BV may activate different signaling pathways, MAPK, caspase 8 and caspase 9. These results propose that BV may induce apoptosis on Hep G2 cells through the activation of MAPK, caspase 8 and caspase 9.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.10
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• pp.5983-5987
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• 2013

Radix Tetrastigma Hemsleyani Flavone (RTHF) is widely used as a traditional herb for its detoxification and anti-inflammation activity. Recently, several studies have shown that RTHF can inhibit growth and induce apoptosis in human cancer cell lines. However, the mechanisms are not completely understood yet. In this study we investigated the potential effects of RTHF on growth and apoptosis in human lung adenocarcinoma A549 cells as well as its mechanisms. A549 cells were treated with RTHF at various concentrations for different times. In vitro the MTT assay showed that RTHF had obvious anti-proliferation effects on A549 cells in a dose- and time-dependent manner. Cell morphological changes observed by inverted microscope and Hoechst33258 methods were compared with apoptotic changes observed by fluorescence microscope. Cell apoptosis inspected by flow cytometry showed significant increase in the treatment group over the control group (P<0.01). Expression of apoptosis related Bax/Bcl-2, caspases and MAPK pathway proteins were detected by Western blotting. The results showed that RTHF up-regulated the Bax/Bcl-2 ratio and cle-caspase3/9, cle-PARP expression in a dose-dependent manner. Expression of p-p38 increased, p-ERK decreased significantly and that of p-JNK was little changed in the RTHF group when compared with the control group. These results suggest that RTHF might exert anti-growth and apoptosis activity against lung cancer A549 cells through activation of caspases and Bcl-2 family proteins and the MAPK pathway, therefore presenting as a promising therapeutic agent for the treatment of lung cancer.

• Journal of Microbiology and Biotechnology
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• v.32 no.9
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• pp.1103-1109
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• 2022

Deoxypodophyllotoxin (DPT), a naturally occurring flavonolignan, possesses several pharmacological properties, including anticancer property. However, the mechanisms underlying DPT mode of action in oral squamous cell carcinoma (OSCC) remain unknown. This study aimed to investigate the anticancer effects of DPT on OSCC and the underlying mechanisms. Results of the MTT assay revealed that DPT significantly reduced the cell viability in a time- and dose-dependent manner. Flow cytometry analysis revealed that DPT induces apoptosis in OSCC cells in a dose-dependent manner. Moreover, DPT enhanced the production of mitochondrial reactive oxygen species (ROS) in OSCC cells. Mechanistically, DPT induced apoptosis in OSCC cells by suppressing the PI3K/AKT signaling pathway while activating the p38 MAPK signaling to regulate the expression of apoptotic proteins. Treatment with SC79, an AKT activator, reversed the effects of DPT on AKT signaling in OSCC cells. Taken together, these results provide the basis for the use of DPT in combination with conventional chemotherapy for the treatment of oral cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1657-1662
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• 2012

Fucosyltransferase IV (FUT4) has been implicated in cell adhesion, motility, and tumor progression in human epidermoid carcinoma A431 cells. We previously reported that it promotes cell proliferation through the ERK/MAPK and PI3K/Akt signaling pathways; however, the molecular mechanisms underlying FUT4-induced cell invasion remain unknown. In this study we determined the effect of FUT4 on expression of matrix metalloproteinase (MMP)-12 induced by EGF in A431 cells. Treatment with EGF resulted in an alteration of cell morphology and induced an increase in the expression of MMP-12. EGF induced nuclear translocation of nuclear factor kB (NF-${\kappa}B$) and resulted in phosphorylation of $IkB{\alpha}$ in a time-dependent manner. In addition, ERK1/2 and p38 MAPK were shown to play a crucial role in mediating EGF-induced NF-${\kappa}B$ translocation and phosphorylation of $I{\kappa}B{\alpha}$ when treated with the MAPK inhibitors, PD98059 and SB203580, which resulted in increased MMP-12 expression. Importantly, we showed that FUT4 up-regulated EGF-induced MMP-12 expression by promoting the phosphorylation of ERK1/2 and p38 MAPK, thereby inducing phosphorylation/degradation of $I{\kappa}B{\alpha}$, NF-${\kappa}B$ activation. Base on our data, we propose that FUT4 up-regulates expression of MMP-12 via a MAPK-NF-${\kappa}B$-dependent mechanism.

• Nutrition Research and Practice
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• v.8 no.4
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• pp.368-376
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• 2014

BACKGROUND/OBJECTIVES: The objectives of this study were to investigate the effects of lycopene on the migration, adhesion, tube formation capacity, and p38 mitogen-activated protein kinase (p38 MAPK) activity of endothelial progenitor cells (EPCs) cultivated with high glucose (HG) and as well as explore the mechanism behind the protective effects of lycopene on peripheral blood EPCs. MATERIALS/METHODS: Mononuclear cells were isolated from human peripheral blood by Ficoll density gradient centrifugation. EPCs were identified after induction of cellular differentiation. Third generation EPCs were incubated with HG (33 mmol/L) or 10, 30, and $50{\mu}g/mL$ of lycopene plus HG. MTT assay and flow cytometry were performed to assess proliferation and apoptosis of EPCs. EPC migration was assessed by MTT assay with a modified boyden chamber. Adhesion assay was performed by replating EPCs on fibronectin-coated dishes, after which adherent cells were counted. In vitro vasculogenesis activity was assayed by Madrigal network formation assay. Western blotting was performed to analyze protein expression of both phosphorylated and non-phosphorylated p38 MAPK. RESULTS: The proliferation, migration, adhesion, and in vitro vasculogenesis capacity of EPCs treated with 10, 30, and $50{\mu}g/mL$ of lycopene plus HG were all significantly higher comapred to the HG group (P < 0.05). Rates of apoptosis were also significantly lower than that of the HG group. Moreover, lycopene blocked phosphorylation of p38 MAPK in EPCs (P < 0.05). To confirm the causal relationship between MAPK inhibition and the protective effects of lycopene against HG-induced cellular injury, we treated cells with SB203580, a phosphorylation inhibitor. The inhibitor significantly inhibited HG-induced EPC injury. CONCLUSIONS: Lycopene promotes proliferation, migration, adhesion, and in vitro vasculogenesis capacity as well as reduces apoptosis of EPCs. Further, the underlying molecular mechanism of the protective effects of lycopene against HG-induced EPC injury may involve the p38 MAPK signal transduction pathway. Specifically, lycopene was shown to inhibit HG-induced EPC injury by inhibiting p38 MAPKs.

• Proceedings of the Microbiological Society of Korea Conference
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• 2007.05a
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• pp.120-122
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• 2007

All living organisms use numerous signal-transduction pathways to sense and respond to their environments and thereby survive and proliferate in a range of biological niches. Molecular dissection of these signalling networks has increased our understanding of these communication processes and provides a platform for therapeutic intervention when these pathways malfunction in disease states, including infection. Owing to the expanding availability of sequenced genomes, a wealth of genetic and molecular tools and the conservation of signalling networks, members of the fungal kingdom serve as excellent model systems for more complex, multicellular organisms. Here, we employed Cryptococcus neoformans as a model system to understand how fungal-signalling circuits operate at the molecular level to sense and respond to a plethora of environmental stresses, including osmoticshock, UV, high temperature, oxidative stress and toxic drugs/metabolites. The stress-activated p38/Hog1 MAPK pathway is structurally conserved in many organisms as diverse as yeast and mammals, but its regulation is uniquely specialized in a majority of clinical Cryptococcus neoformans serotype A and D strains to control differentiation and virulence factor regulation. C. neoformans Hog1 MAPK is controlled by Pbs2 MAPK kinase (MAPKK). The Pbs2-Hog1 MAPK cascade is controlled by the fungal "two-component" system that is composed of a response regulator, Ssk1, and multiple sensor kinases, including two-component.like (Tco) 1 and Tco2. Tco1 and Tco2 play shared and distinct roles in stress responses and drug sensitivity through the Hog1 MAPK system. Furthermore, each sensor kinase mediates unique cellular functions for virulence and morphological differentiation. We also identified and characterized the Ssk2 MAPKKK upstream of the MAPKK Pbs2 and the MAPK Hog1 in C. neoformans. The SSK2 gene was identified as a potential component responsible for differential Hog1 regulation between the serotype D sibling f1 strains B3501 and B3502 through comparative analysis of their meiotic map with the meiotic segregation of Hog1-dependent sensitivity to the fungicide fludioxonil. Ssk2 is the only polymorphic component in the Hog1 MAPK module, including two coding sequence changes between the SSK2 alleles in B3501 and B3502 strains. To further support this finding, the SSK2 allele exchange completely swapped Hog1-related phenotypes between B3501 and B3502 strains. In the serotype A strain H99, disruption of the SSK2 gene dramatically enhanced capsule biosynthesis and mating efficiency, similar to pbs2 and hog1 mutations. Furthermore, ssk2, pbs2, and hog1 mutants are all hypersensitive to a variety of stresses and completely resistant to fludioxonil. Taken together, these findings indicate that Ssk2 is the critical interface protein connecting the two-component system and the Pbs2-Hog1 pathway in C. neoformans.