• Journal of Ginseng Research
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• v.41 no.2
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• pp.227-231
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• 2017

Background: Ginsenosides are active components of Panax ginseng that exert various health benefits including kidney protection effect. The medicinal activity of ginsenosides can be enhanced by modulating their stereospecificity by heat processing. Ginsenosides Rk2 and Rh3 represent positional isomers of the double bond at C-20(21) or C-20(22). Methods: The present study investigated the kidney-protective effects of ginsenosides Rk2 and Rh3 against cisplatin, a platinum based anticancer drug, induced apoptotic damage in renal proximal LLC-PK1 cells. Results: As a result, ginsenoside Rh3 shows a stronger protective effect than that shown by Rk2. Cisplatin-induced elevated protein levels of phosphorylated c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), p38, and cleaved caspase-3 decreased after cotreatment with ginsenoside Rh3. The increase in the percentage of apoptotic LLC-PK1 cells induced by cisplatin treatment also significantly reduced after cotreatment with ginsenoside Rh3. Conclusion: These results demonstrate that inhibition of the JNK and ERK mitogen-activated protein kinase signaling cascade plays a critical role in mediating the renoprotective effect of ginsenoside Rh3.

• Tuberculosis and Respiratory Diseases
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• v.54 no.4
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• pp.403-414
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• 2003

Background : Proteasome inhibitors can promote either cell survival or programmed cell death, depending on both the specific type and proliferative status of the cell. However, it is not well known whether inhibition of proteasome activity is related to apoptosis in lung cancer cells. In addition, the exact mechanisms responsible for apoptosis induced by proteasome inhibition are not well understood. In the present study, we have examined the effect of proteasome inhibition on lung cancer cells and tried to test the mechanisms that may be associated with the apoptosis of these cells. Methods : We examined the effect of proteasome inhibition with MG132 or PS-341 on cell survival in A549 and NCI-H157 lung cancer cells using MTT assay, and analyzed the cleavage of PARP by Western blot analysis to find evidence of apoptosis. Next, we evaluated the activation of caspase 3 by Western blot analysis and the activity of JNK by immunocomplex kinase assay. We also examined the changes in anti-apoptotic pathways like ERK and cIAP1 by Western blot analysis after inhibition of proteasome function. Results : We demonstrated that MG132 reduced cell survival by inducing apoptosis in A549 and NCI-H157 cells. Proteasome inhibition with MG132 or PS-341 was associated with activation of caspase 3 and JNK, reduced expression of activated ERK, and downregulation of cIAP1. Conclusion : Apoptosis induced by proteasome inhibition may be associated with the activation of pro-apoptotic pathways like caspase 3 and JNK and the inactivation of anti-apoptotic pathways in lung cancer cells.

• Archives of Pharmacal Research
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• v.29 no.8
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• pp.633-644
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• 2006

In last couple of decades the use of natural compounds like flavonoids as chemopreventive agents has gained much attention. Our current study focuses on identifying chemopreventive flavonoids and their mechanism of action on human prostate cancer cells. Human prostate cancer cells (PC3), stably transfected with activator protein 1 (AP-1) luciferase reporter gene were treated with four main classes of flavonoids namely flavonols, flavones, flavonones, and isoflavones. The maximum AP-1 luciferase induction of about 3 fold over control was observed with $20\;{\mu}M$ concentrations of quercetin, chrysin and genistein and $50\;{\mu}M$ concentration of kaempferol. At higher concentrations, most of the flavonoids demonstrated inhibition of AP-1 activity. The MTS assay for cell viability at 24 h showed that even at a very high concentration $(500\;{\mu}M)$, cell death was minimal for most of the flavonoids. To determine the role of MAPK pathway in the induction of AP-1 by flavonoids, Western blot of phospho MAPK proteins was performed. Four out of the eight flavonoids namely kaempferol, apigenin, genistein and naringenin were used for the Western Blot analysis. Induction of phospho-JNK and phospho-ERK activity was observed after two hour incubation of PC3-AP1 cells with flavonoids. However no induction of phospho-p38 activity was observed. Furthermore, pretreating the cells with specific inhibitors of JNK reduced the AP-1 luciferase activity that was induced by genistein while pretreatment with MEK inhibitor reduced the AP-1 luciferase activity induced by kaempferol. The pharmacological inhibitors did not affect the AP-1 luciferase activity induced by apigenin and naringenin. These results suggest the possible involvement of JNK pathway in genistein induced AP-1 activity while the ERK pathway seems to play an important role in kaempferol induced AP-1 activity.

• Journal of Life Science
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• v.26 no.2
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• pp.212-219
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• 2016

Glioblastoma multiforme is the most common and most aggressive type of primary brain tumor in humans. Despite intensive treatment, including surgery, radiation, and chemotherapy, most patients die of the disease. Although the anti-cancer activity of resveratrol has been demonstrated in various cancer cell types, its underlying mechanism in glioma cells is not fully elucidated. The present study was undertaken to investigate the effect of resveratrol on cell viability and to determine the molecular mechanism in A172 human glioma cells. Resveratrol caused the generation of reactive oxygen species (ROS), and resveratrol-induced cell death was prevented by antioxidants (N-acetylcysteine and catalase), suggesting that an oxidative mechanism is responsible for resveratrol-induced cell death. Resveratrol-induced phosphorylation of extracellular signal-regulated kinase (ERK), p38 kinase, and c-Jun N-terminal kinase (JNK), and resveratrol-induced cell death were prevented by inhibitors of these kinases. Resveratrol-induced activation of caspase-3 and cell death were prevented by the caspase inhibitors. ERK activation and caspase-3 activation induced by resveratrol was blocked by N-acetylcysteine. Taken together, these results suggest that resveratrol causes a caspase-dependent cell death via activation of ERK, p38, and JNK, mediated by ROS generation, in human glioma cells.

• Journal of the Korean Applied Science and Technology
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• v.36 no.2
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• pp.468-478
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• 2019

The aim of this study is to evaluate the efficacy of cordyceps militaris extracts for the improvement of cognitive dysfunction in PC12 and BV2 cells. Cordyceps militaris extracts was prepared by extracting with distilled water. Cell viability was assessed by MTT assay using PC12 cells and BV2 cells. Confirmed effects of L-glutamate induced cytotoxicity test, Acetylcoline (ACh) concentration, and Acetylcolinestase (AChE) activity in PC12 cells. Anti-inflammatory activities of cordyceps militaris extracts was measured through changes in the levels of nitric oxide (NO), and prostaglandin E2 ($PGE_2$) on lipopolysaccharide(LPS)-induced BV2 cell. In addition, we measured the expression of $NF-{\kappa}B$, p38, JNK, and caspase-3 in western blot analysis. Cordyceps militaris extracts showed no cytotoxicity at the concentrations of 1, 10, and $100{\mu}g/m{\ell}$ except for the concentration of $200{\mu}g/m{\ell}$. Cordyceps militaris extracts protected the cell and exhibited significant increases in the ACh concentration and a significant decrease in the AChE activity in L-glutamate induced PC12 cells. Moreover, cordyceps militaris extracts inhibited the productions NO, and PGE2 level and the protein expression of $NF-{\kappa}B$, p38, JNK, caspase-3 in LPS-induced BV2 cells. These results indicate that cordyceps militaris extracts possible prevented and improved cognitive dysfuction symptoms. Thus, cordyceps militaris extracts may be a novel natural material option for the improvement of cognitive dysfunction.

• Journal of Photoscience
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• v.9 no.2
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• pp.217-220
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• 2002

Ultraviolet B (UVB) radiation may activate or deteriorate cultured human epidermal melanocytes, depending on the doses and culture conditions. In this study, we examined whether apoptosis of melanocytes can be induced by physiologic doses of UVB irradiation. PI staining for DNA condensation and flow cytometric analyses demonstrated the apoptotic cell death of melanocytes after UVB irradiation. The level of p53 and Bax revealed a dose-dependent increase with increasing dose of UVB, but the level of Bcl-2 remained unchanged. Confocal microscopic examination showed that Bax moved trom a diffuse to a punctate distribution after UVB irradiation. However, there were no changes in the pattern of Bcl-2. We next examined the downstream targets of apoptosis. Our results showed that a precursor form of caspase-3 disappeared with increasing doses of UVB. We also observed cleavage of poly(ADP-ribose) polymerase (PARP) after UVB irradiation. In addition, UVB irradiation resulted in a remarkable activation of c-Jun N-terminal kinase (JNK). These results indicate that UVB may induce apoptosis via JNK activation in human melanocytes.

• The Journal of Pediatrics of Korean Medicine
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• v.34 no.1
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• pp.37-47
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• 2020

Objectives After inducing dermatitis in 6-week-old mice, we tried to find out the effects of recovery in the damaged skin by administering genistein and palmitoylethanolamide (PEA) Methods The 6-week-old mice were divided into the control group (Ctrl), dermatitis causing group (AcDE), genistein-administered group after the onset of dermatitis (GsT), and PEA-administered group after the onset of dermatitis (PEAT). Seven mice were assigned to each group. Changes in the skin barrier were observed after three days of administration following the onset of dermatitis. Results In the GsT and PEAT, there was less skin damage compared to the AcDE, and the lowest skin damage showed in the GsT. The intensity of CB1 and CB2 expression was increased by 64% (CB1) and 39% (CB2) in the GsT, and 38% (CB1) and 28% (CB2) in the PEAT compared to the AcDE. The E-catherin positive reaction was decreased in the AcDE, while the E-catherin positive reaction was increased in the GsT (76%) and PEAT (34%). The p-JNK positive reaction was increased in the AcDE, while the p-JNK positive reaction was decreased in the GsT (60%) and PEAT (39%). Toxic Hepatopathy was not observed in the liver tissue of Genistein administered 3OGsT, and PEA administered 3OPEAT. Conclusions Genistein has recovery effect on dermatitis damage through active induction of the endocannabin system (ECS).

• International Journal of Oral Biology
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• v.42 no.3
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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.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.3
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• pp.548-555
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• 2008

Rubiae radix belonging to the family Rubiaceae have been used in traditional medicine to blood stasis and hemostasis. In this study, we reported that methanol extract of Rubiae radix (RRME) induced apoptotic cell death through MAPKs activation in human promylocytic leukemia (HL-60) cells. The cytotoxic activity of activity of RRME in HL-60 cells was increased in a dose-dependent manner. RRME was cytotoxic to HL-60 cells, with IC50 of $8{\mu}g/mL$. Treatment of RRME to HL-60 cells showed apoptotic bodies, and the fragmentation of DNA, suggesting that these cells underwent apoptosis. Caspase-3 activity and PARP cleavage were time-dependently increased the expression of Bcl-2 and Bax. And ratio of Bax/Bcl-2 protein expression. Activation of p38 and JNK were increased 6 hr after RRME treatment in HL-60 cells, but activation of ERK was reduced 24 hr after treatment. Taken together, these results suggest that RRME induces apoptotic cell death through activation of p38 and JNK in HL-60 cells.

• Archives of Pharmacal Research
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• v.26 no.9
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• pp.739-746
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• 2003

Ultraviolet B (UVB) is known to induce apoptosis in human melanocytes. Here we show the cytoprotective effect of sphingosine-1-phosphate (S1P) against UVB-induced apoptosis. We also show that UVB-induced apoptosis of melanocytes is mediated by caspase-3 activation and poly(ADP-ribose) polymerase (PARP) cleavage, and that S1P prevents apoptosis by inhibiting this apoptotic pathway. We further investigated three major mitogen-activated protein (MAP) kinases after UVB irradiation. UVB gradually activated c-Jun N-terminal kinase (JNK) and p38 MAP kinase, while extracellular signal-regulated protein kinase (ERK) was inactivated transiently. Blocking of the p38 MAP kinase pathway using SB203580 promoted cell survival and inhibited the activation of caspase-3 and PARP cleavage. These results suggest that p38 MAP kinase activation may play an important role in the UVB-induced apoptosis of human melanocytes. To explain this cytoprotective effect, we next examined whether S1P could inhibit UVB-induced JNK and p38 MAP kinase activation. However, S1P was not found to have any influence on UVB-induced JNK or p38 MAP kinase activation. In contrast, S1P clearly stimulated the phosphorylation of ERK, and the specific inhibition of the ERK pathway using PD98059 abolished the cytoprotective effect of S1P. Based on these results, we conclude that the activation of p38 MAP kinase plays an important role in UVB-induced apoptosis, and that S1P may show its cytoprotective effect through ERK activation in human melanocytes.