• Animal cells and systems
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• v.15 no.1
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• pp.9-17
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• 2011

Colorectal cancer is the third leading cause of cancer-related death in Western countries. Chemotherapeutic agents with different mechanisms of action have shown an increase in cure rates. In the present study, we investigated the effect of a combination of low concentration of paclitaxel (taxol, 5 nM) and topoisomerase 1 inhibitor camptothecin (CPT) on HCT116 colon cancer cells. Although the viability of cells treated with taxol alone was similar to that of control cells, sequential treatment with taxol and CPT exhibited high cytotoxicity. However, the opposite sequence of treatment did not exert cytotoxic effects on HCT116 cells. This enhanced cytotoxicity of the sequential combination therapy was the result of mitotic arrest, which increased the level of $p21^{Cip1/WAF1}$ through the p38 mitogen-activated protein kinase (MAPK) pathway. Knockdown by $p21^{Cip1/WAF1}$ siRNA or treatment with a p38 inhibitor reduced the viability of cells sequentially exposed to taxol and CPT. Taken together, a low taxol concentration in combination with CPT induced mitotic arrest in HCT116 cells, leading to synergistic cell death through enhanced expression of $p21^{Cip1/WAF1}$ and p38 MAPK pathway. Therefore, taxol could playa role as a sensitizer of CPT in colon cancer cells.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.107-107
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• 2022

Scrophularia koraiensis Nakai is widely used to remedy fever, edema, and neuritis. S. koraiensis has harpagoside and angoroside C, these compounds have been reported to alleviate inflammation, rheumatic diseases, and analgesic stimulation. We evaluated the anti-inflammatory effects of the ethanol extract of S. koraiensis (SKE) in lipopolysaccharides (LPS)-induced macrophages. At cellular levels, SKE decreased the production of nitric oxide (NO), the expression of inducible nitric oxide synthase (iNOS), and cytokines (IL-1b, TNF-a, and IL-6) under the LPS stimulation. SKE inhibited the phosphorylation of nuclear transcription factor-kappa B (NF-κB) p65 and its inhibitor (IκB-α). In addition, SKE suppressed the phosphorylation of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 in the mitogen-activated protein kinase (MAPK) pathway. In conclusion, SKE could be considered a potential resource for attenuating inflammation response and it may be utilized in the material for cosmetics, food additives, and tea.

• The Korean Journal of Physiology and Pharmacology
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• v.26 no.4
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• pp.229-238
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• 2022

Severe bacterial infections are frequently accompanied by depressed neutrophil functions. Thus, agents that increase the microbicidal activity of neutrophils could add to a direct antimicrobial therapy. Lysophosphatidylcholine augments neutrophil bactericidal activity via the glycine (Gly)/glycine receptor (GlyR) α2/TRPM2/p38 mitogen-activated protein kinase (MAPK) pathway. However, the direct effect of glycine on neutrophil bactericidal activity was not reported. In this study, the effect of glycine on neutrophil bactericidal activity was examined. Glycine augmented bactericidal activity of human neutrophils (EC₅₀ = 238 μM) in a strychnine (a GlyR antagonist)-sensitive manner. Glycine augmented bacterial clearance in mice, which was also blocked by strychnine (0.4 mg/kg, s.c.). Glycine enhanced NADPH oxidase-mediated reactive oxygen species (ROS) production and TRPM2-mediated [Ca²⁺]_i increase in neutrophils that had taken up E. coli. Glycine augmented Lucifer yellow uptake (fluid-phase pinocytosis) and azurophil granule-phagosome fusion in neutrophils that had taken up E. coli in an SB203580 (a p38 MAPK inhibitor)-sensitive manner. These findings indicate that glycine augments neutrophil microbicidal activity by enhancing azurophil granule-phagosome fusion via the GlyRα2/ROS/calcium/p38 MAPK pathway. We suggest that glycine could be a useful agent for increasing neutrophil bacterial clearance.

• Korean Journal of Clinical Laboratory Science
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• v.54 no.3
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• pp.201-208
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• 2022

Neuroinflammation is defined as a neurological inflammation within the brain and the spinal cord. In neuroinflammation, microglia are the tissue-resident macrophages of the central nervous system, which act as the first line of defense against harmful pathogens. Dexmedetomidine (Dex) has an anti-inflammatory effect in many neurological conditions. Additionally, the microRNA-30a-5p (miR-30a-5p) mimic has been proven to be effective in macrophages in inflammatory conditions. This study aimed to investigate the synergistic anti-inflammatory effects of both miR-30a-5p and Dex in lipopolysaccharide (LPS)-induced BV2 cells. This study showed that miR-30a-5p and Dex decreased nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) translocation in LPS-induced BV2 cells. MiR-30a-5p and Dex alleviated tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), LPS-induced phosphorylation c-Jun N-terminal kinases (JNK), extracellular signal-regulated kinase (ERK) and p38. Also, the expression of the NOD-like receptor pyrin domain containing 3 inflammasome (NLRP3), cleaved caspase-1, and ASC was inhibited. Furthermore, LPS-stimulated nitric oxide (NO) production, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) expression were attenuated by Dex and miR-30a-5p. Our results indicate that a combination of Dex and miR-30a-5p, attenuates NF-κB activation, the mitogen-activated protein kinase (MAPK) signaling pathway, and inflammatory mediators involved in LPS-induced inflammation and inhibits the activation of the NLRP3 inflammasome in LPS-activated BV2 cells.

• Journal of Ginseng Research
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• v.39 no.1
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• pp.54-60
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• 2015

Background: The present study was designed to prepare and find the optimum active preparation or fraction from Korea Red Ginseng inhibiting matrix metalloproteinase-13 (MMP-13) expression, because MMP-13 is a pivotal enzyme to degrade the collagen matrix of the joint cartilage. Methods: From total red ginseng ethanol extract, n-BuOH fraction (total ginsenoside-enriched fraction), ginsenoside diol-type-enriched fraction (GDF), and ginsenoside triol-type-enriched fraction (GTF) were prepared, and ginsenoside diol type-/F4-enriched fraction (GDF/F4) was obtained from Panax ginseng leaf extract. Results: The n-BuOH fraction, GDF, and GDF/F4 clearly inhibited MMP-13 expression compared to interleukin-$1{\beta}$-treated SW1353 cells (human chondrosarcoma), whereas the total extract and ginsenoside diol-type-enriched fraction did not. In particular, GDF/F4, the most effective inhibitor, blocked the activation of p38 mitogen-activated protein kinase (p38 MAPK), c-Jun-activated protein kinase (JNK), and signal transducer and activator of transcription-1/2 (STAT-1/2) among the signal transcription pathways involved. Further, GDF/F4 also inhibited the glycosaminoglycan release from interleukin-$1{\alpha}$-treated rabbit cartilage culture (30.6% inhibition at $30{\mu}g/mL$). Conclusion: Some preparations from Korean Red Ginseng and ginseng leaves, particularly GDF/F4, may possess the protective activity against cartilage degradation in joint disorders, and may have potential as new therapeutic agents.

• Journal of Applied Biological Chemistry
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• v.61 no.4
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• pp.417-421
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• 2018

Ultraviolet rays are electromagnetic waves with a shorter wavelength than visible light, and ultraviolet rays that pass through the ozone layer are the main cause of skin aging. Chronic exposure of skin tissue to ultraviolet light activates the Mitogen-activated Protein Kinases (MAPKs) signaling pathways in human keratinocytes, resulting in increased production of matrix metalloproteinases (MMPs). In this study, we investigated the herbal extracts from Jeju Island on the anti-aging effect in human keratinocytes (HaCaTs) by ultraviolet stimulation. We examined that herb extract from Jeju Island were decreased in anti-aging activity on measuring the level of MMP-1 gene and protein expression in ultraviolet-induced keratinocytes. As a result, it was confirmed that Thymus quinquecostatus extract (TQE) significantly reduced the expression of MMP-1 in a dose-dependent manner by UV irradiated HaCaTs. According to our data, TQE significantly attenuated UV-induced phosphorylation of the MAPKs signaling elements ERK1/2, JNK1/2 and p38 proteins. These results suggest that the MAPKs pathway may contribute to the inhibitory effect of TQE on UV-induced MMP-1 production in human keratinocytes. Our results suggest that TQE may be a protective agent against skin aging by preventing UV-induced MMP-1 production.

• Bulletin of the Korean Chemical Society
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• v.35 no.8
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• pp.2494-2504
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• 2014

P38 mitogen activated protein (MAP) kinase is an important anti-inflammatory drug target, which can be activated by responding to various stimuli such as stress and immune response. Based on the conformation of the conserved DFG loop (in or out), binding inhibitors are termed as type-I and II. Type-I inhibitors are ATP competitive, whereas type-II inhibitors bind in DFG-out conformation of allosteric pocket. It remains unclear that how these allosteric inhibitors stabilize the DFG-out conformation and interact. Organosilicon compounds provide unusual opportunity to enhance potency and diversity of drug molecules due to their low toxicity. However, very few examples have been reported to utilize this property. In this regard, we performed docking of an inhibitor (BIRB) and its silicon analog (Si-BIRB) in an allosteric binding pocket of p38. Further, molecular dynamics (MD) simulations were performed to study the dynamic behavior of the simulated complexes. The difference in the biological activity and mechanism of action of the simulated inhibitors could be explained based on the molecular mechanics/generalized Born surface area (MM/GBSA) binding free energy per residue decomposition. MM/GBSA showed that biological activities were related with calculated binding free energy of inhibitors. Analyses of the per-residue decomposed energy indicated that van der Waals and non-polar interactions were predominant in the ligand-protein interactions. Further, crucial residues identified for hydrogen bond, salt bridge and hydrophobic interactions were Tyr35, Lys53, Glu71, Leu74, Leu75, Ile84, Met109, Leu167, Asp168 and Phe169. Our results indicate that stronger hydrophobic interaction of Si-BIRB with the binding site residues could be responsible for its greater binding affinity compared with BIRB.

• The Korean Journal of Physiology and Pharmacology
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• v.26 no.5
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• pp.389-396
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• 2022

The increased expression of receptors for advanced glycation end-product (RAGE) is known as a key player in the progression of vascular remodeling. However, the precise signal pathways regulating RAGE expression in vascular smooth muscle cells (VSMCs) in the injured vasculatures are unclear. Given the importance of mitogen-activated protein kinase (MAPK) signaling in cell proliferation, we investigated the importance of MAPK signaling in high-mobility group box 1 (HMGB1)-induced RAGE expression in VSMCs. In HMGB1 (100 ng/ml)-stimulated human VSMCs, the expression of RAGE mRNA and protein was increased in association with an increase in AGE-induced VSMC proliferation. The HMGB1-induced RAGE expression was attenuated in cells pretreated with inhibitors for ERK (PD98059, 10 μM) and p38 MAPK (SB203580, 10 μM) as well as in cells deficient in ERK and p38 MAPK using siRNAs, but not in cells deficient of JNK signaling. In cells stimulated with HMGB1, the phosphorylation of ERK, JNK, and p38 MAPK was increased. This increase in ERK and p38 MAPK phosphorylation was inhibited by p38 MAPK and ERK inhibitors, respectively, but not by JNK inhibitor. Moreover, AGE-induced VSMC proliferation in HMGB1-stimulated cells was attenuated in cells treated with ERK and p38 MAPK inhibitors. Taken together, our results indicate that ERK and p38 MAPK signaling are involved in RAGE expression in HMGB1-stimulated VSMCs. Thus, the ERK/p38 MAPK-RAGE signaling axis in VSMCs was suggested as a potential therapeutic target for vascular remodeling in the injured vasculatures.

• Nutrition Research and Practice
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• v.10 no.3
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• pp.251-258
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• 2016

BACKGROUND/OBJECTIVES: Several pharmacological properties of red rice extract have been reported including anti-oxidant, anti-tumor, and reduced cancer cell invasion. This study was conducted to evaluate the anti-inflammatory effects of red rice extract on the production of inflammatory mediators in lipopolysaccharide (LPS)-induced Raw 264.7 macrophages. MATERIALS/METHODS: Pro-inflammatory cytokines including tumor necrosis factor-${\alpha}$ and interleukin-6 were determined by ELISA and cyclooxygenase-2 and inducible nitric oxide synthase expression was evaluated using western blot analysis. In addition, the signaling pathway controlling the inflammatory cascade such as nuclear factor kappa B ($NF-{\kappa}B$), activator proteins-1 (AP-1), and mitogen-activated protein kinase (MAPK) was determined. RESULTS: Our results showed that red rice polar extract fraction (RR-P), but not non-polar extract fraction, inhibited interleukin-6, tumor necrosis factor-${\alpha}$, and nitric oxide production in LPS-induced Raw 264.7 cells. RR-P also reduced the expression of inflammatory enzymes, inducible nitric oxide synthase, and cyclooxygenase-2. In addition, activation of AP-1 and $NF-{\kappa}B$ transcription factor in the nucleus was abrogated by RR-P. RR-P inhibited the phosphorylation of extracellular signaling-regulated kinase 1/2, c-Jun NH2-terminal kinase, and p38 MAPK signaling responsible for the expression of inflammatory mediators in LPS-stimulated Raw 264.7 cells. Based on chemical analysis, high amounts of proanthocyanidin and catechins were detected in the RR-P fraction. However, only proanthocyanidin reduced $NF-{\kappa}B$ and AP-1 activation in LPS-activated Raw 264.7 cells. CONCLUSION: These observations suggest that the anti-inflammatory properties of RR-P may stem from the inhibition of pro-inflammatory mediators via suppression of the AP-1, $NF-{\kappa}B$, and MAPKs pathways.

• Journal of Ginseng Research
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• v.38 no.1
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• pp.34-39
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• 2014

Cigarette smoke is considered a major risk factor for vascular diseases. There are many toxic compounds in cigarette smoke, including acrolein and other ${\alpha},{\beta}$-unsaturated aldehydes, which are regarded as mediators of inflammation and vascular dysfunction. Furthermore, recent studies have revealed that acrolein, an ${\alpha},{\beta}$-unsaturated aldehyde in cigarette smoke, induces inflammatory mediator expression, which is known to be related to vascular diseases. In this study, we investigated whether Korean Red Ginseng (KRG) water extract suppressed acrolein-induced cyclooxygenase (COX)-2 expression in human umbilical vein endothelial cells (HUVECs). Acrolein-induced COX-2 expression was accompanied by increased levels of phosphorylated p38 in HUVECs and KRG inhibited COX-2 expression in HUVECs. These results suggest that KRG suppresses acrolein-induced COX-2 expression via inhibition of the p38 mitogen-activated protein kinase signaling pathway. In addition, KRG exhibited an inhibitory effect on acrolein-induced apoptosis, as demonstrated by annexin Vepropidium iodide staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay. Consistent with these results, KRG may exert a vasculoprotective effect through inhibition of COX-2 expression in acrolein-stimulated human endothelial cells.