• 대한한의학회지
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• 제38권4호
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• pp.62-81
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• 2017

Objectives: As interests in the beauty of skin is growing continuously, more people are focusing on white and clean skin. Melanin is the major factor that determines skin color. The abnormal concentration of melanin causes various skin diseases such as vitiligo, freckles, and melasma. This study investigated the inhibitory effect of Eriobotryae Folium extracts (EF) with phreatic water (PW) on the melanin synthesis. Methods: The effect of EF on melanin synthesis was evaluated by using mouse melanoma cells (B16F10). To define the mechanisms, real-time PCR and western blot were used. We also evaluated the inhibitory effects of EF and PW on melanin synthesis by using HRM-2 melanin-possessing hairless mice. After UVB irradiation, melanin differences between the skin parts that were treated and untreated with EF and PW. Levels of mRNA were measured by real-time quantitative PCR and histological analysis of the dorsal skin was conducted by hematoxylin and eosin staining. Results: EF inhibited various mechanisms of melanogenesis, and the effect was increased when combined with PW. In vitro experiments have shown that EF inhibited the expressions of tyrosinase related protein-1 (TRP-1) mRNA, tyrosinase mRNA, microphthalmia-associated transcription factor (MITF) mRNA and the tyrosinase inhibitory activation, but it stimulated the extracellular regulated kinase (ERK) mRNA expression. In vivo experiments have shown that EF prevented melanogenesis in the mice dorsal skin and inhibited TRP-1 mRNA expression. Also these effects were increased when combined with PW. Conclusions: EF and PW might be a new and effective treatment for whitening and treating pigmentation of skin.

• Environmental Analysis Health and Toxicology
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• 제15권3호
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• pp.69-80
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• 2000

ADP-rubosylation may be involved in the process of macrophage activation. Nitric oxide (NO) has emerged as an important intracellular and interacellular regulatory molecule with function as diverse as vasodilation, neural communication or host defense. NO is derived from the oxidation of the terminal guanidino nitrogen atom of L-arginine by the NADPH -dependent enzyme, nitric oxide synthase (NOS) which is one of the three different isomers in mammalian tissues. Since NO can exert protective or regulatory functions in the cell at a low concentration while toxic effects at higher concentrations, its role may be tightly regulated in the cell. Therefore, this paper was focused on signal transduction pathway of NO synthesis, role of endogenous TGF-$\beta$ in NO production. effect of NO on superoxide formation. Costimulation of murine peritoneal macrophages with interferon-gamma (IFN-γ) and phorbol 12-myristate 13-acetate (PMA) increased both NO secretion and mRNA expression of inducible nitric oxide synthase (iNOS) when PMA abolished costimulation. Pretreatmnet of the cells with PMA abolished costimuation effects due to the depletion of protein kinase C (PKC) activities . The involvement of PKC in NO secretion could be further confirmed by PKC inhibitor, stauroprine, and phorbol ester derivative, phorbol 12,13-didecanoate. Addition of actinomycine D in IFN-γ plus PMA stimulated cells inhibited both NO secretion and mRNA expression of iNOS indication that PMA stabilizes mRNA of iNOS . Exogenous TGF-$\beta$ reduced NO secretion in IFN -γ stimulated murine macrophages. However addition of antisense oligodeoxynucleotide (ODN) to TGF-$\beta$ to this system recovered the ability of NO production and inhibited mRNA expression of TGF-$\beta$. ACAS interactive laser cytometry analysis showed that transportation of FITC -labeled antisense ODN complementary to TGF-$\beta$ mRNA could be observed within 5 min and reached maximal intensity in 30 min in the murine macrophage cells. NO released by activated macrophages inhibits superoxide formation in the same cells . This inhibition nay be related on NO-induced auto -adenosine diphosphate (ADP) -ribosylation . In addition, ADP-ribosylation may be involved in the process of macrophage activation .

• The Korean Journal of Physiology and Pharmacology
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• 제9권2호
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• pp.131-135
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• 2005

Potassium channels in human skin fibroblast have been studied as a possible site of Alzheimer disease pathogenesis. Fibroblasts in Alzheimer disease show alterations in signal transduction pathway such as changes in $Ca^{2+}$ homeostasis and/or $Ca^{2+}-activated$ kinases, phosphatidylinositol cascade, protein kinase C activity, cAMP levels and absence of specific $K^+$ channel. However, little is known so far about electrophysiological and pharmacological characteristics of large-conductance $Ca^{2+}$-activated $K^+$ ($BK_{Ca}$) channel in human fibroblast (CRL-1474). In the present study, we found Iberiotoxin- and TEA-sensitive outward rectifying oscillatory current with whole-cell recordings. Single channel analysis showed large conductance $K^{+}$ channels (106 pS of chord conductance at +40 mV in physiological $K^+$ gradient). The 106 pS channels were activated by membrane potential and $[Ca^{2+}]_i$, consistent with the known properties of $BK_{Ca}$ channels. $BK_{Ca}$ channels in CRL-1474 were positively regulated by adenylate cyclase activator ($10{\mu}M$ forskolin), 8-Br-cyclic AMP ($300{\mu}M$) or 8-Br-cyclic GMP ($300{\mu}M$). These results suggest that human skin fibroblasts (CR-1474) have typical $BK_{Ca}$ channel and this channel could be modulated by c-AMP and c-GMP. The electrophysiological characteristics of fibroblasts might be used as the diagnostic clues for Alzheimer disease.

• Journal of Microbiology and Biotechnology
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• 제23권10호
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• pp.1357-1364
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• 2013

Human skin is continuously exposed to ultraviolet (UV)-induced photoaging. UVA increases the activity of MMP-1 in dermal fibroblasts through mitogen-activated protein kinase (MAPK), p38, signaling. The irradiation of keratinocytes by UVA results in the secretion of the inflammatory cytokine, tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), and the stimulation of MMP-1 in normal human dermal fibroblasts (NHDFs). Lipoteichoic acid (LTA) is a component of the cell wall of gram-positive Lactobacillus spp. of bacteria. LTA is well known as an anti-inflammation molecule. LTA of the bacterium Lactobacillus plantarum has an anti-photoaging effect, but the potential anti-photoaging effect of the other bacteria has not been examined to date. The current study showed that L. sakei LTA (sLTA) has an immune modulating effect in human monocyte cells. Our object was whether inhibitory effects of sLTA on MMP-1 are caused from reducing the MAPK signal in NHDFs. It inhibits MMP-1 and MAPK signaling induced by UVA in NHDFs. We also confirmed effects of sLTA suppressing TNF-${\alpha}$ inducing MMP-1 in NHDFs.

• The Korean Journal of Physiology and Pharmacology
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• 제6권2호
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• pp.109-112
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• 2002

The signal pathways involved in the regulation of AP-1 DNA binding activity in long-term nicotine stimulated bovine adrenal medullary chromaffin (BAMC) cells have not been well characterized. To understand the involvement of second messengers in the regulation of AP-1 DNA binding activity, the present study was designed to define the time-course for inhibition of nicotine-induced responses by cholinergic antagonists, $Ca^{2+}$ and calmodulin (CaM) antagonists, and calcium/calmodulin-dependent protein kinase (CaMK) II inhibitor using electrophoretic mobility shift assay. Nicotine $(10{\mu}M)$ stimulation increased AP-1 DNA binding activity at 24 hr after treatment. Posttreatment with hexamethonium (1 mM) plus atropine $(1{\mu}M)$ (HA), nimodipine $(1{\mu}M),$ or calmidazolium $(1{\mu}M)$ at 0.5, 3, and 6 hr after the nicotine treatment significantly inhibited the AP-1 DNA binding activity increased by long-term nicotine stimulation. However, posttreatment with HA, nimodipine, or calmidazolium at 9 or 12 hr after the nicotine treatment did not affect the nicotine-induced increase of AP-1 DNA binding activity. The pretreatment of BAMC cells with various concentrations of KN-62 inhibited the increase of AP-1 DNA binding activity induced by nicotine in a concentration-dependent manner. KN-62 $(10{\mu}M)$ posttreatment beginning at 0.5, 3, or 6 hr after the nicotine treatment significantly inhibited the increase of AP-1 DNA binding activity. However, KN-62 posttreatment beginning at 9 or 12 hr after the nicotine treatment did not affect the increase of AP-1 DNA binding activity. This study suggested that stimulation (for at least 6 hr) of nicotinic receptors on BAMC cells was necessary for increase of AP-1 DNA binding activity, and activation of $Ca^{2+},$ CaM, and CaMK II up to 6 hr at least seemed to be required for the increase of nicotine-induced AP-1 DNA binding activity.

• The Korean Journal of Physiology and Pharmacology
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• 제15권6호
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• pp.389-395
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• 2011

Repeated administration of psychostimulants such as cocaine leads to the development of behavioral sensitization. Extracellular signal-Regulated Kinase (ERK), an enzyme important for long-term neuronal plasticity, has been implicated in such effects of these drugs. Although the nucleus accumbens (NAcc) is the site mediating the expression of behavioral sensitization by drugs of abuse, the precise role of ERK activation in this site has not been determined. In this study we demonstrate that blockade of ERK phosphorylation in the NAcc by a single bilateral microinjections of PD98059 (0.5 or $2.0{\mu}g/side$), or U0126 (0.1 or $1.0{\mu}g/side$), into this site dose-dependently inhibited the expression of cocaine-induced behavioral sensitization when measured at day 7 following 6 consecutive daily cocaine injections (15 mg/kg, i.p.). Acute microinjection of either vehicle or PD98059 alone produced no different locomotor activity compared to saline control. Further, microinjection of PD98059 ($2.0{\mu}g/side$) in the NAcc specifically lowered cocaine-induced increase of ERK phosphorylation levels in this site, while unaffecting p-38 protein levels. These results indicate that ERK activation in the NAcc is necessary for the expression of cocaine-induced behavioral sensitization, and further suggest that repeated cocaine evokes neuronal plasticity involving ERK pathway in this site leading to long-lasting behavioral changes.

• The Korean Journal of Physiology and Pharmacology
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• 제13권6호
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• pp.491-496
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• 2009

Skeletal muscle atrophy is a common phenomenon during the prolonged muscle disuse caused by cast immobilization, extended aging states, bed rest, space flight, or other factors. However, the cellular mechanisms of the atrophic process are poorly understood. In this study, we investigated the involvement of mitogen-activated protein kinase (MAPK) in the expression of muscle-specific RING finger 1 (MuRF1) during atrophy of the rat gastrocnemius muscle. Histological analysis revealed that cast immobilization induced the atrophy of the gastrocnemius muscle, with diminution of muscle weight and cross-sectional area after 14 days. Cast immobilization significantly elevated the expression of MuRF1 and the phosphorylation of p38 MAPK. The starvation of L6 rat skeletal myoblasts under serum-free conditions induced the phosphorylation of p38 MAPK and the characteristics typical of cast-immobilized gastrocnemius muscle. The expression of MuRF1 was also elevated in serum-starved L6 myoblasts, but was significantly attenuated by SB203580, an inhibitor of p38 MAPK. Changes in the sizes of L6 myoblasts in response to starvation were also reversed by their transfection with MuRF1 small interfering RNA or treatment with SB203580. From these results, we suggest that the expression of MuRF1 in cast-immobilized atrophy is regulated by p38 MAPK in rat gastrocnemius muscles.

• International Journal of Oral Biology
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• 제42권3호
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• pp.91-97
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• 2017

Although anti-aging activities of melatonin, a hormone secreted by the pineal gland, have been reported in senescence-accelerated mouse models and several types of cells, its impact and mechanism on the senescence of human dental pulp cells (HDPCs) remains unknown. In this study, we examined the impact of melatonin on cellular premature senescence of HDPCs. Here, we found that melatonin markedly inhibited senescent characteristics of HDPCs after exposure to hydrogen peroxide ($H_2O_2$), including the increase in senescence-associated ${\beta}$-galactosidase (SA-${\beta}$-gal)-positive HDPCs and the upregulation of p21 protein, an indicator for senescence. In addition, as melatonin attenuated $H_2O_2$-stimulated phosphorylation of c-Jun N-terminal kinase (JNK), while selective inhibition of JNK activity with SP600125 significantly attenuated $H_2O_2$-induced increase in SA-beta-gal activity. Results reveal that melatonin antagonizes premature senescence of HDPCs via JNK pathway. Thus, melatonin may have therapeutic potential to prevent stress-induced premature senescence, possibly correlated with development of dental pulp diseases, and to maintain oral health across the life span.

• IMMUNE NETWORK
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• 제7권4호
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• pp.203-208
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• 2007

Background: Angiogenesis mediated by VEGF constitutes a new target for anti-cancer therapy which has explored through different ways of intervention aiming at the blocking of the tumoral angiogenesis. In the present study, we developed the assays by which efficacies of anti-VEGF inhibitor candidates are evaluated at the various levels. Methods & Results: First, we developed two sandwich ELISAs using coated anti-VEGF Ab and soluble Flt-1 receptor fusion protein (sFlt-1/Fc). As low as 200 pg/ml of hVEGF diluted in human sera was detectable by these assays. In addition, we found that VEGF inhibitors ($2{\mu}g/ml$ of either anti-VEGF Ab or sFlt-1/Fc) completely block 5 ng/ml VEGF in these ELISAs. Subsequently, two bioassays, wound healing and HUVEC tube formation assays, revealed that anti-VEGF Ab $(1{\mu}g/ml)$ & sFlt-1/Fc Ab $(1{\mu}g/ml)$, or SU5416 (VEGFR tyrosine kinase inhibitor, $1{\mu}M$) prevents the activity of VEGF $(1{\sim}10ng/ml)$. Finally, secretion of MMP-9 by VEGF-stimulated macrophages was abolished by treatment of anti-VEGF Ab $(1{\mu}g/ml)$ in gelatin zymography. Conclusion: ELISAs together with bioassays developed in this study are appropriate for evaluation of the efficacy of inhibitors of VEGF.

• Molecular & Cellular Toxicology
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• 제2권2호
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• pp.141-149
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• 2006

Tamoxifen (TAM), a non-steroidal anti estrogen anticancer drug and chemopreventive agent for breast cancer, have caused cholestasis in liver. The potent hepatocarcinogenicity of this drug has been reported. Methotrexate (MTX) is dihydrofolate reductase inhibitor which interfaces with the synthesis for urine nucleotide and dTMP. And it may cause atrophy, necrosis and steatosis in liver. These two anticancer drug have well-known hepatotoxicity. So, in this study we compare the gene expression pattern of antitumor agent TAM and MTX, using the cDNA microarray. We have used 4.8 K cDNA microarray to identify hepatotoxicity-related genes in 5-week-old male Sprague-Dawley (SD) rats. Confirm the pattern of gene expression, we have used Real time PCR for targeted gene. In the case of MTX, Protease related gene (Ctse, Ctsk) and Protein kinase (Pctk 1) have shown specific expression pattern. And in the case of TAM, apoptosis related gene (Pdcd 8) and signal transduction related gene (kdr) have significantly up regulated during treatment time. Gene related with growth factor, lipid synthesis, chemokins were significantly changed. From the result of this study, the information about influence of TAM and MTX to hepatoxicity will provide.