• International Journal of Oral Biology
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• 제42권4호
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• pp.149-153
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• 2017

Cyclooxygenase-2 (COX-2)-mediated prostaglandin $E_2$ ($PGE_2$) plays a key role in development and progression of inflammatory responses and Porphyromonas gingivalis is a common endodontic pathogen. In this study, we investigated induction of COX-2 and $PGE_2$ by P. gingivalis in human dental pulp cells (HDPCs). P. gingivalis increased expression of COX-2, but not that of COX-1. Increased levels of $PGE_2$ were released from P. gingivalis-infected HDPCs and this $PGE_2$ increase was blocked by celecoxib, a selective COX-2 inhibitor. P. gingivalis activated all three types of mitogen-activated protein kinases (MAPKs). P. gingivalis-induced activation of nuclear $factor-{\kappa}B$ ($NF-{\kappa}B$) was demonstrated by the results of phosphorylation of $NF-{\kappa}B$ p65 and degradation of inhibitor of ${\kappa}B-{\alpha}$ ($I{\kappa}B-{\alpha}$). Pharmacological inhibition of each of the three types of MAPKs and $NF-{\kappa}B$ substantially attenuated P. gingivalis-induced $PGE_2$ production. These results suggest that P. gingivalis should promote endodontic inflammation by stimulating dental pulp cells to produce $PGE_2$.

• BMB Reports
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• 제47권7호
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• pp.382-387
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• 2014

Corn silk (CS) has long been consumed as a traditional herb in Korea. Maysin is a major flavonoid of CS. The effects of maysin on macrophage activation were evaluated, using the murine macrophage RAW 264.7 cells. Maysin was isolated from CS by methanol extraction, and preparative $C_{18}$ reverse phase column chromatography. Maysin was nontoxic up to $100{\mu}g/ml$, and dose-dependently increased TNF-${\alpha}$ secretion and iNOS production by 11.2- and 4.2-fold, respectively, compared to untreated control. The activation and subsequent nuclear translocation of NF-${\kappa}B$ was substantially enhanced upon treatment with maysin ($1-100{\mu}g/ml$). Maysin also stimulated the phosphorylation of Akt and MAPKs (ERK, JNK). These results indicated that maysin activates macrophages to secrete TNF-${\alpha}$ and induce iNOS expression, via the activation of the Akt, NF-${\kappa}B$ and MAPKs signaling pathways. These results suggest for the first time that maysin can be a new immunomodulator, enhancing the early innate immunity.

• 동의생리병리학회지
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• 제19권2호
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• pp.501-507
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• 2005

Shikonin is a chemically characterized component of traditional herbal medicine, the root of Lithospermum erythrorhizon and has been shown to possess antitumor activities. Here we investigated anticancer potential of shikonin and its possible mechanism of action in LLC cells. Shikonin inhibited the proliferation of LLC cells in a concentration-dependent manner. It was also demonstrated that shikonin induced apoptosis in LLC cells by Annexin V staining and TUNEL staining analysis. Shikonin treatment was caused that decrease of Bcl-2, activation of caspases and cleavage of PARP. And shikonin also induced that the activation of mitogen-activated protein kinases (MAPKs), such as extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38. Interestingly, the cell proliferation inhibition induced by shikonin was recovered by specific inhibitors of JNK and p38 but the inhibitor of MEK, the upstream kinase of ERK, did not recover. Additionally, shikonin administration at doses of 5 mg/kg in C57BL/6 mice strongly inhibited the primary tumor growth of LLC. Taken together, these results suggest that shikonin may suppress LLC cell proliferation by inducing an apoptotic process via activation of caspases and MAPKs

• Biomolecules & Therapeutics
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• 제25권2호
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• pp.158-164
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• 2017

Methylglyoxal (MGO) is a highly reactive metabolite of glucose which is known to cause damage and induce apoptosis in endothelial cells. Endothelial cell damage is implicated in the progression of diabetes-associated complications and atherosclerosis. Hypericin, a naphthodianthrone isolated from Hypericum perforatum L. (St. John's Wort), is a potent and selective inhibitor of protein kinase C and is reported to reduce neuropathic pain. In this work, we investigated the protective effect of hypericin on MGO-induced apoptosis in human umbilical vein endothelial cells (HUVECs). Hypericin showed significant anti-apoptotic activity in MGO-treated HUVECs. Pretreatment with hypericin significantly inhibited MGO-induced changes in cell morphology, cell death, and production of intracellular reactive oxygen species. Hypericin prevented MGO-induced apoptosis in HUVECs by increasing Bcl-2 expression and decreasing Bax expression. MGO was found to activate mitogen-activated protein kinases (MAPKs). Pretreatment with hypericin strongly inhibited the activation of MAPKs, including P38, JNK, and ERK1/2. Interestingly, hypericin also inhibited the formation of AGEs. These findings suggest that hypericin may be an effective regulator of MGO-induced apoptosis. In conclusion, hypericin downregulated the formation of AGEs and ameliorated MGO-induced dysfunction in human endothelial cells.

• 한국식품과학회지
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• 제52권6호
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• pp.622-626
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• 2020

Recent studies have suggested that Canavalia gladiate, a dietary food and traditional folk medicine, has promising pharmaceutical potential, but the effects have mostly been demonstrated using its organo-soluble extract. To date, its immunomodulatory effect depending on the extraction method is unclear. Here, the immune responses of macrophages to C. gladiate and the underlying mechanisms were studied. C. gladiate hot water extract (CGW) induced cytokine production in bone marrow-derived macrophages (BMDMs) in a dose-dependent manner, whereas its ethanolic extract (CGE) did not. Immunoblotting analysis also showed that CGW activated nuclear factor (NF)-κB and mitogen-activated protein kinases (MAPKs). Moreover, an inhibitor assay revealed the involvement of NF-κB, p38, and JNK, but not ERK, in CGW-induced cytokine production. CGE inhibited lipopolysaccharide-stimulated production of pro-inflammatory cytokines and activation of NF-κB and MAPKs in BMDMs. The results suggest that C. gladiate regulates the immune responses of macrophages differently depending on the extraction method.

• 동의생리병리학회지
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• 제35권5호
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• pp.177-184
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• 2021

The root bark of Morus alba L. (MA) used in traditional oriental medicine for the treatment of pulmonary diseases exerts various pharmacological activities including anticancer effects. In the current study, we investigated the effects of MA on the migration and invasion of colorectal carcinoma cells. Results from a transwell assay showed that the methylene chloride extract of MA (MEMA) suppressed the migration and invasion of HCT116 human colorectal carcinoma cells in a concentration-dependent manner. MEMA reduced both mRNA and protein levels of matrix metalloproteinase (MMP)-9, but did not suppress the expression of MMP-2 in HCT116 cells. As a molecular mechanism, MEMA inhibited the phosphorylation of mitogen-activated protein kinases (MAPKs), including ERK, JNK and p38, in a dose-dependent manner. In addition, MEMA dephosphorylated both Src and signal transducer and activator of transcription 3 (STAT3) in HCT116 cells. Taken together, we demonstrate that MEMA suppressed the migration and invasion capacity of HCT116 human colorectal cancer cells by downregulation of MMP-9 and inactivation of both MAPKs and Src/STAT3 signaling pathway.

• Biomolecules & Therapeutics
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• 제30권6호
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• pp.501-509
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• 2022

Atopic dermatitis (AD) is a chronic inflammatory skin disorder. Suppression of MAPKs and NF-κB is implicated as a vital mechanism of action of several traditional Chinese medicines for AD therapy. Although overexpression of MAPK mRNA in the skin tissue has been shown in the AD model, the roles of each MAPK in AD pathogenesis have rarely been studied. This study examined the effect of NJK14047, an inhibitor of p38 MAPKs, on AD-like skin lesions induced in BALB/c mice by sensitization and challenges with 1-chloro-2,4-dinitrobenzene (CDNB) on dorsal skin and ears, respectively. After induction of AD, NJK14047 (2.5 mg/kg) or dexamethasone (10 mg/kg) was administrated for 3 weeks via intraperitoneal injection. Following its administration, NJK14047 suppressed CDNB-induced AD-like symptoms such as skin hypertrophy and suppressed mast cell infiltration into the skin lesions. It also reduced CDNB-induced increase in T_H2 cytokine (IL-13) and T_H1 cytokines (interferon-γ and IL-12A) levels but did not decrease serum IgE level. Furthermore, NJK14047 blocked CDNB-induced lymph node enlargement. These results suggest that NJK14047, a p38 MAPK inhibitor, might be an optimal therapeutic option with unique modes of action for AD treatment.

• 한방안이비인후피부과학회지
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• 제36권1호
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• pp.40-49
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• 2023

Objectives : This study was conducted to confirm the skin anti-aging effect of Chungpyesagan-tang(CPSGT) extract. Methods : We performed MMT assay to confirm the cytotoxicity of CPSGT. After inducing matrix metalloproteinase-1(MMP-1) with tumor necrosis factor-α(TNF-α), we investigated mRNA expression and protein secretion of MMP-1 by real-time RT-PCR and ELISA. In addition, we measured the protein expression of mitogen-activated protein kinases(MAPKs) and transcription factors by western blot. Results : CPSGT was not cytotoxic at 25-800㎍/㎖. The mRNA expression and protein secretion of MMP-1 decreased when treated with CPSGT. The protein expression of p-ERK, p-JNK, p-p38 was decreased by CPSGT. In addition, the protein expression of p-c-jun and p-NF-κB, which are transcription factors, were also decreased. Conclusion : This suggests that CPSGT can inhibit MMP-1 and thus be a potential anti-aging substance.

• 대한화학회지
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• 제66권4호
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• pp.298-304
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• 2022

The present study was designed to investigate the molecular mechanisms of DK-5-62, a novel (-)-catechin derivative on HCT116 human colorectal cancer cells. DK-5-62 inhibited the proliferation in dose- and time-dependent manner accompanied by the morphological changes. Effects of DK-5-62 appeared to be mediated by the induction of apoptosis, as manifested through DNA-binding dye Hoechst 33258 staining. Analysis of the mechanism of these events indicated that DK-5-62-treated cells exhibited an increased ratio of Bax/Bcl-2, resulting in the activation of caspase-9, caspase-3, and poly-ADP-ribose polymerase in a dose-dependent manner. Moreover, DK-5-62-induced apoptosis was accompanied by phosphorylation of the mitogen-activated protein kinase family, c-Jun N-terminal kinase, p38, and extracellular signal-regulated kinase. These results suggest that HCT116 cells are moderately sensitive to growth inhibition by DK-5-62 via apoptosis, as evidenced by activation of ERK/p38/Bcl-2 family signaling, as well as alteration in caspase-9 and caspase-3.

• 대한한의학회지
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• 제43권1호
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• pp.99-111
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• 2022

Objectives: Rehmanniae Radix Preparata (RRP) has been used as a traditional remedy to treat gynecology and endocrine diseases. Recently, studies on antioxidant and anti-inflammatory effects of RRP have been reported, so it was judged that RRP extracts would have an anti-depressive effect. Methods: We investigated the anti-neuroinflammatory and anti-depressive effect of RRP on lipopolysaccharide (LPS)-induced depression and LPS-stimulated BV2 microglia. RRP inhibited the LPS-stimulated excessive release of nitrite in the BV2 cells. RRP also significantly inhibited the inflammatory cytokines such as tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta and IL-6 in LPS-stimulated BV2 microglial cells. Results: RRP significantly suppressed the LPS-induced mitogen-activated protein kinase (MAPKs) and nuclear factor (NF)-𝜅B activation. In addition, administration of RRP not only inhibited the immobility time in the forced swimming test (FST) but also increased the total travel distance in the open field test (OFT). Also, RRP inhibited the elevation of TNF-alpha, IL-1beta, and IL-6 in brain of LPS-injected mice. Conclusions: Considering the overall results, our study showed that RRP exhibited the anti-neuroinflammatory and anti-depressive activities via deactivation of MAPKs and NF-𝜅B.