• Journal of the Korean Crystal Growth and Crystal Technology
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• v.31 no.4
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• pp.149-153
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• 2021

ε-Ga₂O₃ thin films were grown on 4H-SiC substrates by metal organic chemical vapor deposition (MOCVD) and crystalline quality were evaluated depend on growth conditions. It was found that the best conditions of the ε-Ga₂O₃ were grown at a growth temperature of 665℃ and an oxygen flow rate of 200 sccm. Two-dimensional growth was completed after the merge of hexagonal nuclei, and the arrangement direction of hexagonal nuclei was closely related to the crystal direction of the substrate. However, it was confirmed that crystal structure of the ε-Ga₂O₃ had an orthorhombic rather than hexagonal. Crystal phase transformation was performed by thermal treatment. And a β-Ga₂O₃ thin film was grown directly on 4H-SiC for the comparison to the phase transformed β-Ga₂O₃ thin film. The phase transformed β-Ga₂O₃ film showed better crystal quality than directly grown one.

• Advances in nano research
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• v.12 no.5
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• pp.501-514
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• 2022

This study aimed to investigate the effects and potential mechanisms of Chikusetsusaponin V (CsV) on endothelial nitric oxide synthase (eNOS) and vascular endothelial cell functions. Different concentrations of CsV were added to animal models, bovine aorta endothelial cells (BAECs) and human umbilical vein endothelial cells (HUVECs) cultured in vitro. qPCR, Western blotting (WB), and B ultrasound were performed to explore the effects of CsV on mouse endothelial cell functions, vascular stiffness and cellular eNOS mRNA, protein expression and NO release. Bioinformatics analysis, network pharmacology, molecular docking and protein mass spectrometry analysis were conducted to jointly predict the upstream transcription factors of eNOS. Furthermore, pulldown and ChIP and dual luciferase assays were employed for subsequent verification. At the presence or absence of CsV stimulation, either overexpression or knockdown of purine rich element binding protein A (PURA) was conducted, and PCR assay was employed to detect PURA and eNOS mRNA expressions, Western blot was used to detect PURA and eNOS protein expressions, cell NO release and serum NO levels. Tube formation experiment was conducted to detect the tube forming capability of HUVECs cells. The animal vasodilation function test detected the vasodilation functions. Ultrasonic detection was performed to determine the mouse aortic arch pulse wave velocity to identify aortic stiffness. CsV stimulus on bovine aortic cells revealed that CsV could upregulate eNOS protein levels in vascular endothelial cells in a concentration and time dependent manner. The expression levels of eNOS mRNA and phosphorylation sites Ser1177, Ser633 and Thr495 increased significantly after CsV stimulation. Meanwhile, CsV could also enhance the tube forming capability of HUVECs cells. Following the mice were gavaged using CsV, the eNOS protein level of mouse aortic endothelial cells was upregulated in a concentration- and time-dependent manner, and serum NO release and vasodilation ability were simultaneously elevated whereas arterial stiffness was alleviated. The pulldown, ChIP and dual luciferase assays demonstrated that PURA could bind to the eNOS promoter and facilitate the transcription of eNOS. Under the conditions of presence or absence of CsV stimulation, overexpression or knockdown of PURA indicated that the effect of CsV on vascular endothelial function and eNOS was weakened following PURA gene silence, whereas overexpression of PURA gene could enhance the effect of CsV upregulating eNOS expression. CsV could promote NO release from endothelial cells by upregulating the expression of PURA/eNOS pathway, improve endothelial cell functions, enhance vasodilation capability, and alleviate vessel stiffness. The present study plays a role in offering a theoretical basis for the development and application of CsV in vascular function improvement, and it also provides a more comprehensive understanding of the pharmacodynamics of CsV.

• Journal of Life Science
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• v.31 no.11
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• pp.969-979
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• 2021

Type 2 diabetes is a serious chronic metabolic disease, and the goal of diabetes treatment is to keep blood glucose at a normal level and prevent complications from diabetes. Hyperglycemia is a key pathologic feature of type 2 diabetes that mainly results from insulin resistance and pancreatic β-cell dysfunction. Chronic exposure of β-cells to elevated glucose concentrations induces glucotoxicity. In this study, we examined whether an 80% ethanol extract of Oxya chinensis sinuosa Mishchenko (OEE) protected INS-1 pancreatic β-cells against glucotoxicity-induced apoptosis and oxidative stress. Pretreatment with a high concentration of glucose (high glucose = 30 mM) induced glucotoxicity and apoptosis of INS-1 pancreatic β cells. Treatment with OEE significantly increased cell viability. Treatment with 0.01-0.20 mg/ml OEE dose dependently decreased intracellular reactive oxygen species, lipid peroxidation, and nitric oxide levels and increased insulin secretion in high glucose-pretreated INS-1 β cells. OEE also significantly increased the activities of antioxidant enzymes in response to high-glucose-induced oxidative stress. Moreover, OEE treatment significantly reduced the expressions of pro-apoptotic proteins, including Bax, cytochrome C, caspase-3, and caspase-9, and increased anti-apoptotic Bcl-2 expression. Apoptotic cells were identified using Annexin-V/propidium iodide staining, which revealed that treatment with OEE significantly reduced high-glucose-induced apoptosis. These findings implicate OEE as a valuable functional food in protecting pancreatic β-cells against glucotoxicity-induced apoptosis and oxidative stress.

• Nutrition Research and Practice
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• v.16 no.6
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• pp.729-744
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• 2022

BACKGROUND/OBJECTIVES: 4-Hydroxy-2-nonenal (HNE) is a biomarker for oxidative stress to induce inflammation. Methionine is an essential sulfur-containing amino acid with antioxidative activity. On the other hand, the evidence on whether and how methionine can depress HNE-derived inflammation is lacking. In particular, the link between the regulation of the nuclear factor-κB (NF-κB) signaling pathway and methionine intake is unclear. This study examined the link between depression from HNE accumulation and the anti-inflammatory function of ⳑ-methionine in rats. MATERIALS/METHODS: Male Wistar rats (3-week-old, weighing 70-80 g) were administered different levels of ⳑ-methionine orally at 215.0, 268.8, 322.5, and 430.0 mg/kg body weight for two weeks. The control group was fed commercial pellets. The hepatic HNE contents and the protein expression and mRNA levels of the inflammatory mediators were measured. The interleukin-10 (IL-10) and glutathione S-transferase (GST) levels were also estimated. RESULTS: Compared to the control group, hepatic HNE levels were reduced significantly in all groups fed ⳑ-methionine, which were attributed to the stimulation of GST by ⳑ-methionine. With decreasing HNE levels, ⳑ-methionine inhibited the activation of NF-κB by up-regulating inhibitory κBα and depressing phosphoinositide 3 kinase/protein kinase B. The mRNA levels of the inflammatory mediators (cyclooxygenase-2, interleukin-1β, interleukin-6, inducible nitric oxide synthase, tumor necrotic factor alpha) were decreased significantly by ⳑ-methionine. In contrast, the protein expression of these inflammatory mediators was effectively down regulated by ⳑ-methionine. The anti-inflammatory action of ⳑ-methionine was also reflected by the up-regulation of IL-10. CONCLUSIONS: This study revealed a link between the inhibition of HNE accumulation and the depression of inflammation in growing rats, which was attributed to ⳑ-methionine availability. The anti-inflammatory mechanism exerted by ⳑ-methionine was to inhibit NF-κB activation and to up-regulate GST.

• The Korea Journal of Herbology
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• v.29 no.2
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• pp.39-45
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• 2014

Objectives : The purpose of this study was to investigate antiaging and antioxidant effects on cultured human skin fibroblast with 80% ethanol extracts of plants including of stem of Dendropanax morbifera, Corni fructus and Lycii Fructus. Methods : An ethanol extract of three medicinal plants including stem of Dendropanax morbifera, Corni fructus and Lycii Fructus. Extracts were assessed to determine the mechanism of antioxidant and antiaging activities. Antioxidant activity of extract was evaluated by two different assays as 2,2-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and super oxide dismutase (SOD) like activities. These extracts were tested for cell viability on HS68 skin fibroblast by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. We investigated the effects of Ultraviolet-B irradiation on cytotoxicity, type 1 collagen, elastin level and oxidative damage in cultured human skin fibroblast (HS68). Recently, many studies have reported that elastin is also involved in inhibiting or repairing wrinkle formation, although collagen is a major factor in the skin wrinkle formation. Results : The extracts obtained dose-dependently increased the scavenging activity on DPPH radical scavenging activity and SOD like activity. The extracts of complex herbal medicine showed low cytotoxicity as more than 100% cell viability in 100ppm/ml concentration. HS68 fibroblasts were survived 70% at 120 $mJ/cm^2$ UVB irradiation and treated tumor necrosis factor (TNF)-alpha. The levels of aging factors and cytotoxicity were decreased by ethanol extract of complex herbal medicine. Conclusions : These results suggest that ethanol extracts of complex medicinal plants of including of stem of Dendropanax morbifera, Corni fructus and Lycii Fructus may have value as the potential antioxidant and antiaging medicinal plant.

• The Korea Journal of Herbology
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• v.29 no.3
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• pp.27-33
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• 2014

Objectives : The aim of this study was to investigate the protective effect of extract of Thuja orientalis leaves (TOFE) against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurotoxicity by inhibition of inflammation in in vitro and in vivo models of Parkinson's disease (PD). Methods : We evaluated the effect of TOFE against lipopolysaccharide (LPS)/1-methyl-4-phenylpyridinium ($MPP^+$) toxicity using nitric oxide (NO) assay, inducible NO synthase and cyclooxygenase 2 western blot, tyrosine hydroxylase and microglia activation immunohistochemistry (IHC) in BV2 cell, primary rat mesencephalic neurons, or C57BL/6 mice. We also evaluated the effect of TOFE in mice PD model induced by MPTP. C57BL/6 mice were treated with TOFE 50 mg/kg for 5 days and were injected intraperitoneally with four administrations of MPTP on the last day. We conducted behavioral tests and IHC analysis to see how TOFE affect MPTP-induced neuronal loss of dopaminergic neurons in substantia nigra pars compacta (SNpc) and striatum (ST) of mice. To assess the anti-inflammation effects, we carried out glial fibrillary acidic protein and macrophage-1 antigen integrin alpha M in IHC in SNpc and ST of mice. Results : In an in vitro system, TOFE decreasesd NO generations in BV2 cells. TOFE protected dopaminergic cells against LPS or $MPP^+$-induced toxicity in primary mesencephalic dopaminergic neurons. In vivo system, TOFE at 50 mg/kg treated group showed improved motor deteriorations than the MPTP only treated group and TOFE significantly protected striatal dopaminergic damage from MPTP-induced neurotoxicity in mice. Moreover, TOFE inhibited activation of astrocyte and microglia in SNpc and ST of the mice. Conclusions : We concluded that TOFE showed anti-parkinsonian effect by protection of dopaminergic neurons against MPTP toxicity through anti-inflammatory actions.

• The Korea Journal of Herbology
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• v.29 no.4
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• pp.69-76
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• 2014

Objectives : Gami-Chunggisan extract (GCE) is one of the oriental traditional medicine. We investigated the antioxidant effect and reduction of pro-inflammatory cytokine as a functional ingredient for cosmetic products from the GCE. Methods : GCE was prepared by extracting with 80% ethanol. We analyzed total polyphenol and antioxidant activities. To evaluate antioxidant activity, we measured 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging assay. Also we measured the production of reactive oxygen species (ROS) and nitric oxide (NO) on Raw264.7 cells. We researched reduction of anti-inflammatory cytokines from concentration of GCE on Raw264.7 cells. Results : Total polyphenol quantity of GCE was included 46.6 mg/g. The GCE showed ABTS free radical scavenging ability with more than 89% at $1000{\mu}g/m{\ell}$. In addition the DPPH free radical scavenging ability from the GCE was activated over 93% at $1000{\mu}g/m{\ell}$. Production of the ROS was decreased by approximately 26%, upon the GCE treatment at concentration of $100{\mu}g/m{\ell}$. The GCE at $100{\mu}g/m{\ell}$ concentration showed inhibitory effect on NO production by 38%. Production of IL-$1{\beta}$ and IL-6 were decreased by approximately 56% and 36%, respectively upon GCE treatment at $100{\mu}g/m{\ell}$. Also, production of TNF-${\alpha}$ was decreased by approximately 79% at $100{\mu}g/m{\ell}$. Moreover, the GCE showed inhibitory effects on the expression of the IL-$1{\beta}$, IL-6 and TNF-${\alpha}$ genes in LPS-induced Raw 264.7 cells. Conclusions : From the results above, we conclude that the GCE indicated significant antioxidant effects and induced reduction of pro-inflammatory cytokine.

• The Korea Journal of Herbology
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• v.28 no.4
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• pp.63-69
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• 2013

Objectives : The purpose of present study was to investigate the vasorelaxant activities and mechanisms of action of the ethanol extract of P. yedoensis leaf (PYL) on isolated rat aortic rings. Methods : Dried P. yedoensis leaves were extracted 3 times with 100% ethanol for 3 h in a reflux apparatus. Isolated rat aortic rings were suspended in organ chambers containing 10 ml Krebs-Henseleit (K-H) solution. The rings were maintained at $37^{\circ}C$ and aerated with a mixture of 95% $O_2$ and 5% $CO_2$. Changes in their tension were recorded via isometric transducers connected to a data acquisition system. Results : PYL relaxed the contraction of aortic rings induced by phenylephrine (PE, 1 ${\mu}M$) or KCl (60 mM) in a concentration dependent manner. However, the vasorelaxant effects of PYL on endothelium-denuded aortic rings were lower than endothelium-intact aortic rings. And the vasorelaxant effects of PYL on endothelium-intact aortic rings were reduced by pre-treatment with $N{\omega}$-Nitro-L-arginine methyl ester (10 ${\mu}M$), methylene blue (10 ${\mu}M$), 1-H-[1,2,4]-oxadiazolo-[4,3-${\alpha}$]-quinoxalin-1-one (10 ${\mu}M$), tetraethylammonium (5 mM). In addition, PYL inhibited the contraction induced by extracellular $Ca^{2+}$ in endothelium-denuded aortic rings pre-contracted by PE or KCl in $Ca^{2+}$-free K-H solution. Conclusions : These results suggest that PYL exerts its vasorelaxant effects via the activation of Nitric Oxide (NO) formation by means of L-arginine and NO-cGMP pathways and via the blockage of receptor operated calcium channels, voltage dependent calcium channels and calcium-activated potassium channels.

• The Korea Journal of Herbology
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• v.28 no.2
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• pp.67-73
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• 2013

Objective : Lithospermum Erythrorhizon (LE) has been used as an anti-bacterial and anti-inflammatory agent. However, it is unclear that LE aqueous extract could show the anti-inflammatory effects in RAW 264.7cells. The purpose of this study was to investigate the anti-inflammatory effect of aqueous extract from LE on lipopolysaccharide (LPS) - induced inflammatory response. Methods : To measure out the cytotoxicity of LE, we performed the MTT assay. To evaluate the anti-inflammatory effects of LE, we examined the inflammatory mediators such as nitric oxide (NO), prostaglandin E2 ($PGE_2$) and pro-inflammatory cytokines (tumor necrosis factor (TNF)-${\alpha}$, interleukin, (IL)-$1{\beta}$ and (IL)-6) on RAW 264.7 cells. We also examined molecular mechanisms such as mitogen-activated protein kinases (MAPKs) and nuclear factor-B (NF-${\kappa}B$) activation by western blot. Results : Aqueous Extract from LE itself did not have any cytotoxic effect in RAW 264.7 cells. Aqueous extract from LE inhibited LPS-induced productions of inflammatory mediators such as NO, $PGE_2$, and pro-inflammatory cytokines including TNF-${\alpha}$, IL-$1{\beta}$ and IL-6 in RAW 264.7cells. In addition, LE inhibited the phosphorylation of p38 kinases (p38), c-Jun $NH_2$-terminal kinase (JNK), and NF-${\kappa}B$ activation in RAW 264.7 cells. Conclusion : LE down-regulated LPS-induced production of inflammatory mediators through the inhibition of p38, JNK and NF-${\kappa}B$ activation. Taken together, these results could provide the evidence for the anti-inflammatory effects of LE. Therefore, LE may be a novel target in the management of inflammation and help to support a potential strategy for prevention and therapy of inflammatory diseases.

• The Korea Journal of Herbology
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• v.28 no.3
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• pp.53-60
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• 2013

Objectives : DojukSan is known to be effective for treating a urinary diseases and stomatitis. However, there has been a lack of studies regarding the effects of Dojuksan on the inflammatory activities and effector inflammatory disease mechanism about macrophage before is not known. To elucidate the molecular mechanisms of Dojuksan water extract (DJS) on pharmacological and biochemical actions in inflammation, we examined the effect of DJS on pro-inflammatory mediators in lipopolysaccharide (LPS)-stimulated macrophages. Methods : In the present study, pro-inflammatory cytokine production was determined by performing enzyme-linked immunosorbent assay, reverse transcription polymerase chain reaction, and western blot analysis to measure the activation of MAPKs. Cells were treated with 200 ng/mL of LPS 1 h prior to the addition of DJS. Cell viability was measured by MTS assay. The investigation focused on whether DJS inhibited nitric oxide (NO) and prostaglandin E2 ($PGE_2$) productions, as well as the expressions of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin-6 (IL-6) and mitogen-activated protein kinases (MAPKs) in LPS-stimulated RAW 264.7 cells. Results : We found that DJS inhibited LPS-induced NO, $PGE_2$ and IL-6 productions as well as the expressions of iNOS and COX-2. Furthermore, DJS suppressed the LPS-induced phosphorylation of p38 MAPK and c-Jun NH2-protein kinase (JNK). Conclusions : These results suggest that DJS has inhibitory effects on LPS-induced $PGE_2$, NO, and IL-6 production, as well as the expressions of iNOS and COX-2 in the murine macrophage. These inhibitory effects occur through blockades on the MAPKs phosphorylation.