• Journal of Microbiology and Biotechnology
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• v.15 no.4
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• pp.756-766
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• 2005

The signaling mechanism underlying aburatubolactam C-induced FasL upregulation was investigated in human Jurkat T cells. After treatment with aburatubolactam C, the src-family PTKs $p56^{lck}\;and\;p59^{fyn}$, and MAP kinases ERK2 and JNK1, were activated prior to FasL upregulation; Both $p56^{lck}\;and\;p59^{fyn}$ were directly activated 2.4- and 2.2-fold, respectively, in vitro by aburatubolactam C. The aburatubolactam C-induced cellular changes, including the activation of ERK2 and INK1, and FasL upregulation, were completely prevented by the PTK inhibitor genistein. The activation of protein kinase C (PKC$\delta,\;\epsilon\;and\;\mu$ was also induced following aburatubolactam C treatment. Although the activation of $p56^{lck}$ and tyrosine phosphorylation of the cellular proteins were not blocked by the PKC inhibitor GFl09203X, the activation of ERK2 was completely abrogated, along with a detectably enhanced JNK1 activation; FasL upregulation, and apoptosis. However, the FasL upregulation and apoptosis were significantly inhibited by the PKC activator PMA, with a remarkable increase in the ERK2 activation. The cytotoxic effect of aburatubolactam C was reduced in the presence of the anti-Fas neutralizing antibody ZB-4. Although ectopic expression of Bcl-2 failed to completely block the cytotoxicity of aburatubolactam C, it was clearly suppressed. The c-Fos mRNA expression was upregulated in a biphasic manner, where the second phasic expression overlapped with the FasL upregulation. Accordingly, these results demonstrate that aburatubolactam C-induced apoptosis is exerted, at least in part, by FasL upregulation dictated by activation of the PTK ($p56^{lck}\;and\;p59^{fyn}$) /JNKI pathway, which is negatively affected by the concurrent activation of the PKC/ERK2 pathway proximal to PTK activation.

• Journal of the Korean Applied Science and Technology
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• v.30 no.1
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• pp.173-182
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• 2013

Atopic dermatitis is a chronic, relapsing inflammatory skin disease associated with dysfunction of skin barrier and cutaneous hyper-reactivity to environmental triggers. In the previous study, cytotoxicity, antioxidant, anti-inflammatory and anti-allergic activities were investigated for various herbal extracts such as Aloe vera L. (AV), Viola mandshurica W. Becker (VM), Punica granatum L. (PG), and Dendrobium nobile L. (DN) in order to develop effective therapeutic herbal extracts for atopic dermatitis, In this study, anti-inflammatory activities of these herb extracts in lipopolysaccharide (LPS)-induced macrophage RAW264.7 cells were further examined to find the underlying molecular mechanisms. The RT-PCR (reverse transcription polymerase chain reaction) analysis showed that PG, DN and AV inhibited effectively the gene expression of pro-inflammatory cytokines IL-6 and IL-$1{\beta}$ in LPS-stimulated macrophages, while VM did not. The transfection and luciferase analysis exhibited that all herbal extracts hindered the activation of transcription nuclear factor kappa B (NF-${\kappa}B$). The western blot analysis indicated that AV blocked the activation of only JNK MAP (c-Jun N-terminal kinase mitogen-activated protein) kinase not p38 MAP kinase, while VM, PG and DN did not show the activation of both JNK and p38 MAP kinases. These results suggest that AV, VM, PG, and DN have anti-inflammatory activities and thus have the potential to reduce and alleviate the symptoms of atopic dermatitis.

• Archives of Pharmacal Research
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• v.23 no.6
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• pp.605-612
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• 2000

Green tea polyphenols (GTP) have been demonstrated to suppress tumorigenesis in several chemical-induced animal carcinogenesis models, and predicted as promising chemopreventive agents in human. Recent studies of GTP extracts showed the involvement of mitogen-activated protein kinases (MAPKs) in the regulation of Phase II enzymes gene expression and induction of apoptosis. In the current work we compared the biological actions of five green tea catechins: (1) induction of ARE reporter gene, (2) activation of MAP kinases, (3) cytotoxicity in human hepatoma HepG2-C8 cells, and (4) caspase activation in human cervical squamous carcinoma HeLa cells. For the induction of phase IIgene assay, (-)-epigallocatechin-3-gallate (EGCG) and (-)-epicatechin-3-gallate (ECG) potently induced antioxidant response element (ARE)-mediated luciferase activity, with induction observed at 25 $\mu\textrm{m}$with EGCG. The induction of ARE reporter gene appears to be structurally related to the 3-gallate group. Comparing the activation of MAPK by the five polyphenols, only EGCG showed potent activation of all three MAPKs (ERK, JNK and p38) in a dose- and time-dependent manner, whereas EGC activated ERK and p38. In the concentration range of 25 $\mu\textrm{m}$ to 1 mM, EGCG and ECG strongly suppressed HepG2-ARE-C8 cell-growth. To elucidate the mechanisms of green tea polyphenol-induced apoptosis, we measured the activation of an important cell death protein, caspase-3 induced by EGCG, and found that caspase-3 was activated in a dose- and time-dependent manner. Interestingly, the activation of caspase-3 was a relatively late event (peaked at 16 h), whereas activation of MAPKs was much earlier (peaked at 2 h). It is possible, that at low concentrations of EGCG, activation of MAPK leads to ARE-mediated gene expression including phase II detoxifying enzymes. Whereas at higher concentrations of EGCG, sustained activation of MAPKs such as JNK leads to apoptosis. These mechanisms are currently under investigation in our laboratory. As the most abundant catechin in GTP extract, we found that EGCG potently induced ARE-mediated gene expression, activated MAP kinase pathway, stimulated caspase-3 activity, and induced apoptosis. These mechanisms together with others, may contribute to the overall chemopreventive function of EGCG itself as well as the GTP.

• The Korean Journal of Pain
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• v.34 no.4
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• pp.405-416
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• 2021

Background: This study investigated the effect of intrathecal Sec-O-glucosylhamaudol (SOG) on the p38/c-Jun N-terminal kinase (JNK) signaling pathways, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)-related inflammatory responses, and autophagy in a spinal nerve ligation (SNL)-induced neuropathic pain model. Methods: The continuous administration of intrathecal SOG via an osmotic pump was performed on male Sprague-Dawley rats (n = 50) with SNL-induced neuropathic pain. Rats were randomized into four groups after the 7th day following SNL and treated for 2 weeks as follows (each n = 10): Group S, sham-operated; Group D, 70% dimethylsulfoxide; Group SOG96, SOG at 96 ㎍/day; and Group SOG192, SOG at 192 ㎍/day. The paw withdrawal threshold (PWT) test was performed to assess neuropathic pain. Western blotting of the spinal cord (L5) was performed to measure changes in the expression of signaling pathway components, cytokines, and autophagy. Additional studies with naloxone challenge (n = 10) and cells were carried out to evaluate the potential mechanisms underlying the effects of SOG. Results: Continuous intrathecal SOG administration increased the PWT with p38/JNK mitogen-activated protein kinase (MAPK) pathway and NF-κB signaling pathway inhibition, which induced a reduction in proinflammatory cytokines with the concomitant downregulation of autophagy. Conclusions: SOG alleviates mechanical allodynia, and its mechanism is thought to be related to the regulation of p38/JNK MAPK and NF-κB signaling pathways, associated with autophagy during neuroinflammatory processes after SNL.

• YAKHAK HOEJI
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• v.57 no.6
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• pp.394-399
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• 2013

In this study we demonstrated whether the extract of Polygonum aviculare L. (PAE) can be applied to the immune-stimulating responses in macrophages (Raw 264.7 cells). Cell viability was determined by WST-8 assay, and all four doses of PAE (5, 10, 20, and 40 ${\mu}g/ml$) had no significant cytotoxicity during the entire experimental period. PAE increased the production of inducible nitric oxide synthase (iNOS) and nitric oxide (NO), and mRNA expressions and protein levels of pro-inflammatory cytokines(tumor necrotic factor (TNF)-${\alpha}$, interleukin (IL)-$1{\beta}$ and IL-6) in the same cells. These immune-stimulating activities of PAE were found to be caused by the stimulation of $NF{\kappa}B$ signal and phosphorylation of MAP kinases (p38, ERK and JNK).

• Journal of the Korean Dietetic Association
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• v.25 no.3
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• pp.217-228
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• 2019

There have been no published studies concerning the anti-inflammatory effects of corn silk on colon cancer cells. Thus, this study was conducted to investigate the effect of corn silk extract containing high levels of maysin on inflammation and its mechanism of action in colon cancer cells. SW 480 human colon cancer cells were treated with $1{\mu}g/mL$ of lipopolysaccharide (LPS) to induce inflammation, and next they were treated with different concentrations of corn silk extract (0, 5, 10 and $15{\mu}g/mL$). The concentrations of nitric oxide (NO) were determined. The mRNA expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor ${\alpha}$ ($TNF-{\alpha}$), interleukin-1beta ($IL-1{\beta}$) and interleukin-6 (IL-6), were determined. Western blot analysis was performed to determine the protein expressions of nuclear factor-kappa B ($NF-{\kappa}B$) and mitogen-activated protein kinases, and the latter consists of extracellular signal-related kinase (ERK), c-jun NH2-terminal kinase (JNK) and p38 MAP kinase (p38). The concentration of NO and the mRNA expression of iNOS were significantly and dose-dependently decreased in the corn silk-treated groups (P<0.05). The mRNA expression of $TNF-{\alpha}$, $IL-1{\beta}$ and IL-6 were significantly increased in the LPS-treated group (P<0.05), but these expressions were significantly and dose-dependently decreased in the corn silk treated groups (P<0.05). The protein expressions of $NF-{\kappa}B$ (in a dose-dependent fashion), ERK (at 10 and $15{\mu}g/mL$), JNK (at $15{\mu}g/mL$) and p38 (at 10 and $15{\mu}g/mL$) were significantly decreased with corn silk treatments (P<0.05). In conclusion, corn silk extract containing high levels of maysin seems to inhibit the LPS-induced inflammatory responses in SW480 colon cancer cells via the $NF-{\kappa}B$ pathway.

• Journal of Applied Biological Chemistry
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• v.57 no.4
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• pp.373-377
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• 2014

In this study, we demonstrated whether the extract of Fomes fomentarius (FFE; FF extract) could be used to stimulate macrophages (RAW 264.7 cells). All four doses of FFE (5, 10, 20, and $40{\mu}g/mL$) had no significant cytotoxicity during the entire experimental period. FFE potently increased the production of nitric oxide (NO). Consistent with these observations, inducible NO synthase levels were increased by FFE in a dose-dependent manner. Moreover, FFE increased the production of tumor necrosis factor-${\alpha}$, interleukin (IL)-$1{\beta}$, and IL-6 in the same cells. These stimulating effects of FFE were found to be caused by the stimulation of phosphorylation of $I{\kappa}B{\alpha}$ and MAP kinases (p38, ERK, and JNK). These results suggest that FFE may be used as new agents for wide application in the immune study of mushroom.

• Journal of Life Science
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• v.19 no.7
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• pp.949-955
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• 2009

Mucosal epithelia sense external stress signals and transmit them to the intracellular cascade responses. Ribotoxic stress-producing chemicals such as deoxynivalenol (DON) or other trichothecene mycotoxins have been linked with gastrointestinal inflammatory diseases by Fusarium-contamination. The purpose of this study was to test the hypothesis that DON evokes the epithelial sentinel signals of RNA-dependent protein kinase (PKR) and early growth response gene 1 (EGR-1), which together contribute to the pro-inflammatory cytokine interleukin 8 (IL-8) in human intestinal epithelial cells. PKR suppression by the dominant negative PKR expression attenuated DON-stimulated interleukin-8 production. Moreover, 1L-8 transcriptional activation by DON was also reduced by PKR inhibition in the human intestinal epithelial cells. Treatment with the PKR inhibitor also suppressed EGR-1 promoter activity, mRNA and protein induction, although mitogen-activated protein (MAP) kinases such as extracellular signal-regulated protein kinases (ERK) 1/2, p38, c-Jun N-terminal Kinase (INK) were little affected or even enhanced in presence of a PKR inhibitor. These patterns were also compared in the EGR-1-suppressed cells, which showed much more suppressed production of 1L-8. All things taken into consideration, DON-activated sentinel signals of EGR-1 via PKR mediated interleukin-8 production in human intestinal epithelial cells, which provide insight into the possible general mechanism associated with mucosal inflammation as an intestinal toxic insult by ribotoxic trichothecene mycotoxins.