• Journal of Microbiology and Biotechnology
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• v.32 no.2
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• pp.263-267
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• 2022

The aim of this study was to determine whether the antibacterial activity of chitosan-modified Fe₃O₄ (CS@Fe₃O₄) nanomaterials against Acinetobacter baumannii (A. baumannii) is mediated through changes in biofilm formation and reactive oxygen species (ROS) production. For this purpose, the broth dilution method was used to examine the effect of CS@Fe₃O₄ nanoparticles on bacterial growth. The effects of CS@Fe₃O₄ nanoparticles on biofilm formation were measured using a semi-quantitative crystal violet staining assay. In addition, a bacterial ROS detection kit was used to detect the production of ROS in bacteria. The results showed that CS@Fe₃O₄ nanoparticles had a significant inhibitory effect on the colony growth and biofilm formation of drug-resistant A. baumannii (p < 0.05). The ROS stress assay revealed significantly higher ROS levels in A. baumannii subjected to CS@Fe₃O₄ nanoparticle treatment than the control group (p < 0.05). Thus, we demonstrated for the first time that CS@Fe₃O₄ nanoparticles had an inhibitory effect on A. baumannii in vitro, and that the antibacterial effect of CS@Fe₃O₄ nanoparticles on drug-resistant A. baumannii was more significant than on drug-sensitive bacteria. Our findings suggest that the antibacterial mechanism of CS@Fe₃O₄ nanoparticles is mediated through inhibition of biofilm formation in drug-resistant bacteria, as well as stimulation of A. baumannii to produce ROS. In summary, our data indicate that CS@Fe₃O₄ nanoparticles could be used to treat infections caused by drug-resistant A. baumannii.

• Restorative Dentistry and Endodontics
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• v.45 no.4
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• pp.47.1-47.11
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• 2020

Objectives: The aim of this study was to assess the physicochemical properties, cytotoxicity and penetration into dentinal tubules of ChlorCid^TM Surf (3% sodium hypochlorite [NaOCl] with surfactant) in comparison to ChlorCid^TM (3% NaOCl without surfactant). Materials and Methods: The physicochemical properties evaluated were pH, surface tension, free available chlorine (FAC) and contact angle. Cytotoxicity was evaluated in L929 fibroblasts exposed to the solutions by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and neutral red assays. Assessment of penetration into dentinal tubules was performed by staining single-rooted permanent human teeth with crystal violet (n = 9), which were irrigated with the solutions and analyzed in cervical, middle and apical segments. Data were analyzed by one-way analysis of variance (ANOVA) and Tukey's post-test, 2-way ANOVA and Bonferroni's post-test or t-test (α = 0.05). Results: ChlorCid^TM Surf and ChlorCid^TM FAC values were close to those indicated by the manufacturer. ChlorCid^TM Surf showed lower surface tension and contact angle on dentin, and higher pH than ChlorCid^TM (p < 0.05). The penetration of ChlorCid^TM Surf was higher in cervical and middle segments, compared with ChlorCid^TM (p < 0.05). There was no difference in irrigant cytotoxicity (p > 0.05). Conclusions: ChlorCid^TM Surf showed lower surface tension, lower contact angle on root canal dentin, higher penetration into dentinal tubules and more alkaline pH, compared with ChlorCid^TM. However, both solutions showed similar cytotoxicity and FAC content.

• Journal of Ginseng Research
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• v.48 no.2
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• pp.171-180
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• 2024

Background: Epimers of ginsenoside Rg3 (Rg3) have a low bioavailability and are prone to deglycosylation, which produces epimers of ginsenoside Rh2 (S-Rh2 and R-Rh2) and protopanaxadiol (S-PPD and R-PPD). The aim of this study was to compare the efficacy and potency of these molecules as anti-cancer agents. Methods: Crystal violet staining was used to study the anti-proliferatory action of the molecules on a human epithelial breast cancer cell line, MDA-MB-231, and human umbilical vein endothelial cells (HUVEC) and compare their potency. Cell death and cell cycle were studied using flow cytometry and mode of cell death was studied using live cell imaging. Anti-angiogenic effects of the drug were studied using loop formation assay. Molecular docking showed the interaction of these molecules with vascular endothelial growth factor receptor-2 (VEGFR2) and aquaporin (AQP) water channels. VEGF bioassay was used to study the interaction of Rh2 with VEGFR2, in vitro. Results: HUVEC was the more sensitive cell line to the anti-proliferative effects of S-Rh2, S-PPD and R-PPD. The molecules induced necroptosis/necrosis in MDA-MB-231 and apoptosis in HUVEC. S-Rh2 was the most potent inhibitor of loop formation. In silico molecular docking predicted a good binding score between Rh2 or PPD and the ATP-binding pocket of VEGFR2. VEGF bioassay showed that Rh2 was an allosteric modulator of VEGFR2. In addition, SRh2 and PPD had good binding scores with AQP1 and AQP5, both of which play roles in cell migration and proliferation. Conclusion: The combination of these molecules might be responsible for the anti-cancer effects observed by Rg3.

• The Journal of Internal Korean Medicine
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• v.34 no.2
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• pp.178-191
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• 2013

Objectives : In this study, we made an effort to investigate the protective mechanism of Ukgan-san (UGS) extracts on hypoxia-induced C6 glial cell death. Methods : The cell viability was assessed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MMT) assay and cell morphological changes were analysed with microscope after staining with crystal violet (CV). Reactive oxygen species (ROS) formation was assessed by flow cytometer after staining with 2'7'-dichlorofluorescein diacetate (DCF-DA). We also analyzed expression of hypoxia-inducible factor-1 alpha (HIF-$1{\alpha}$) and p53, processing of procaspase-3 and procyclic acidic repetitive protein (PARP) by western blot method. Results : We estimated the elevated cell viability by UGS extract on $CoCl_2$-induced C6 glial cells. UGS attenuated $CoCl_2$-induced ROS formation in C6 glial cells and also showed a protective activity compared to antioxidants and exhibited abrogation of LDH-released by $CoCl_2$. UGS suppressed the typical apoptotic cell death markers, caspase-3 and PARP activation. UGS inhibited $CoCl_2$-induced HIF-1${\alpha}$ expression which is known as a major regulator for hypoxia-induced cell death, and suppressed p53 expression. Conclusions : These results suggest that UGS extract contains protective constituents for hypoxia-induced C6 glial cell death.

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.1
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• pp.14-22
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• 2020

Purpose: The aim of this study is to evaluate the effectiveness of MnO₂-diatom microbubbler (DM) on the surface of prosthetic materials as a mouthwash by comparing the biofilm removal effect with those previously used as a mouthwash in dental clinic. Materials and methods: DM was fabricated by doping manganese dioxide nanosheets to the diatom cylinder surface. Scanning electron microscopy (SEM) was used to observe the morphology of DM and to analyze the composition of doped MnO₂. Stereomicroscope was used to observe the reaction of DM in 3% hydrogen peroxide. Non-precious metal alloys, zirconia and resin specimens were prepared to evaluate the effect of biofilm removal on the surface of prosthetic materials. And then Streptococcus mutans and Porphyromonas gingivalis biofilms were formed on the specimens. When 3% hydrogen peroxide solution and DM were treated on the biofilms, the decontamination effect was compared with chlorhexidine gluconate and 3% hydrogen peroxide solution by crystal violet staining. Results: Manganese dioxide was found on the surface of the diatom cylinder, and it was found to produce bubble of oxygen gas when added to 3% hydrogen peroxide. For all materials used in the experiments, biofilms of the DM-treated groups got effectively removed compared to the groups used with chlorhexidine gluconate or 3% hydrogen peroxide alone. Conclusion: MnO₂-diatom microbubbler can remove bacterial membranes on the surface of prosthetic materials more effectively than conventional mouthwashes.

• Tuberculosis and Respiratory Diseases
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• v.56 no.2
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• pp.187-197
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• 2004

Background : Nitric Oxide (NO) is a multi-faceted molecule with dichotomous regulatory roles in many areas of biology. NO can promote apoptosis in some cells, whereas it inhibits apoptosis in other cell types. This study was performed to characterize NO-induced cell death in lung epithelial cells and to investigate the roles of cell death regulators including iron, bcl-2 and p53. Methods : A549 cells were used for lung epithelial cells. SNP (sodium nitroprusside) and SNAP (S-nitroso-N-acetyl- penicillamine) were used for NO donor. Cytoxicity assay was done by MTT assay and crystal violet assay. Apoptotic assay was done by fluorescent microscopy after double staining with propidium iodide and hoecst 33342. Iron inhibition study was done with RBCs and FeSO4. For bcl-2 study, bcl-2 overexpressing cells (A549-bcl-2) were used and for p53 study, Western blot analysis and p53 functionally knock-out cells (A549-E6) were used. Results : SNP and SNAP induced dose-dependent cell death in A549 cells and fluorescent microscopy revealed that SNAP induced apoptosis in low doses but necrosis in high doses while SNP induced exclusively necrotic cell death. Iron inhibition study using RBCs and FeSO4 significantly blocked SNAP-induced cell death. And also SNAP-induced cell death was blocked by bcl-2 overexpression. Finally, we found that SNAP activate p53 by Western blot analysis and that SNAP-induced cell death was decreased in the abscence of p53. Conclusion : In lung epithelial cells, NO can induce cell death, more precisely apoptosis in low doses and necrosis in high doses. And iron, bcl-2, and p53 play important roles in NO-induced cell death.

• Radiation Oncology Journal
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• v.12 no.1
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• pp.27-31
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• 1994

There are a number of reports suggesting that there may be a correlation between the clinical response to radiotherapy in various tumors and the clonogenic survival of cell lines derived from these tumors following exposure to 2 Gy(SF2). Authors conducted this study to determine SF2 for cells in primary culture from surgical specimens. The tumor tissues with squamous cell carcinoma of uterine cervix and head and neck were obtained. The tumor tissues were disaggregated to single cells by incubating with collagenase type w for 2 hours with constant stirring. Single cell suspensions were inoculated in four 24-well plates precoated with cell adhesive matrix. After 24 hours of incubation at 37$ ^{\circ}C $, rows of four wells were then irradiated, consisting of control set and five other sets each receiving doses of 1,2,3,4, and 6 Gy. After incubation for a total of 13 days, the cultures were stained with crystal violet and survival at each dose was determined by quantitative image analysis system, To determine whether cell growth was of epithelial origin, immunocytochemical staining with a mixture of cytokeratin and epithelial monoclonal antibodies were performed on cell cultures. During the period of this study, we received 5 squamous cell carcinoma specimens of head and neck and 20 of uterine cervical carcinoma. Of these, 15 yielded enough cells for radiosensitivity testing. This resulted an overall success rate of 60$ \% $. The mean SF2 value for 15 tumours was 0.55$\pm$0.17 ranging from 0.20 to 0.79. These results indicate that there is a broad range of sensitivities to radiation in same histologic type. So with a large patient population, we plan to determine whether a different SF2 value is associated with tumours that are controlled with radiotherapy than those that are not.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.4
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• pp.437-445
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• 2017

The aim of this study was to investigate the effects of green tea, black tea, barley tea and roasted corn tea used in South Korea to make tea on the formation of Streptococcus mutans biofilm. The aqueous samples of 4 types of tea were extracted from commercial tea bags using cold water ($7^{\circ}C$) or hot water ($72^{\circ}C$). S. mutans UA 159 was introduced into 96-well plates which contained the tea samples and 1% sucrose media. Crystal violet staining was used to assess the effects of teas on S. mutans biofilm formation. In both groups of green tea and black tea, the biofilm significantly decreased with the solution of $50{\mu}L$ aqueous sample in $200{\mu}L$ media and $100{\mu}L$ aqueous sample in $100{\mu}L$ media (p < 0.05). S. mutans biofilm with $25{\mu}L$ of barley tea or roasted corn tea aqueous sample in hot water ($72^{\circ}C$) for 10 minutes showed significant decrease compared of green tea or black tea (p < 0.05). In this study, green tea and black tea suppress the formation of S. mutans biofilm.

• The Journal of Internal Korean Medicine
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• v.21 no.3
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• pp.443-452
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• 2000

Objective : This study was designed to evaluate the synergistic effect on cytotoxicity of combination with adriamycin and Palginhonhapwhajucwhan, a traditional prescription for cancer treatment in oriental medicine, in Chang, HL-60, Hep-3B and Alexander cells. Methods : We observed cell viability in Chang, HL-60, Hep-3B, and Alexander cells by crystal violet staining. Those cells were treated with various concentrations of adriamycin alone, Palginhonhapwhajucwhan alone and combination of two medications for 10 hr. On condition of $0.5{\mu}l/ml$ adriamycin alone, $15.6{\mu}l/ml$ Paljintanghapwhajucwhan alone and combination of two medications, at first, we observed colony forming of Chang and HL-60 cells. Second, we observed DNA fragmentation by agarose electrophoresis in Chang, HL-60, Hep-38 and Alexander cells. Third, we measured the catalytic activation of caspase-1, 2, 3, 6, 8, and 9 protease in Chang cells and caspase-3 protease in Chang, HL-60, Hep-3B and Alexander cells by using fluorogenic substrate. Finally, we isolated mRNA of Fas in Chang, HL-60, Hep-38 and Alexander cells and observed that Fas gene was amplified by RT-PCR Results : 1. The combination of adriamycin and Palginhonhapwhajucwhan synergistically augmented the cytotoxicity of Chang and HL-60 cells whereas did not in Hep-38 and Alexander cells. 2. Cotreatment of two drugs also markedly inhibited the colony forming ability both in Chang and HL-60 cells. 3. The cytotoxicity of these medicatons was revealed as apoptosis characterized by high molecular wight DNA fragmentaton. 4. The apoptotic cytotoxicity was mediated by activation of caspase-3 protease in Chang cells. 5. Synergistic increase in apoptotic cytotoxicity by combination of two medications was dependent on the expression of Fas in cancer cells. Conclusions : Combination of adriamycin and Palginhonhapwhajucwhan significantly augmented apoptotic cytotoxicity of Fas-positive cells such as Chang and HL-60 cells via acticaton of apoptosis signaling pathway.

• The Journal of Internal Korean Medicine
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• v.21 no.1
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• pp.65-73
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• 2000

Objectives : The effects of cotreatment of adriamycin and ethanol extract of herb (Palgin-tang hab Hwajuck-hwan a traditional medicine for cancer treatment in oriental medicine) on the induction of apoptotic cell death were investigated in human liver origin cell lines, Chang. Methods : Chang(ATCC) liver cells were cultured in RPMI-1640(Gibco SRL Co, Gaithersburg, MD) badge including 10% fetal bovine serum. Chang liver cells were treated with various concentrations(from 10 to $0.16{\mu}l$) of adriamycin and herb extract(from 500 to $31.25{\mu}l$) After 48h later, the cells were tested for viability by Crystal violet staining assay. Adriamycin and Herb extract induced ladder pattern of DNA fragmentation in Chang cells. Genomic DNA was isolated and separated on 1.5% agarose gels. The DNA was stained with ethidium bromide and visualized under UV light. Results : The death of Chang cells was synergistically induced by the cotreatment of adriamycin and ethanol extract of herb. In addition, the cotreatment-induced cell death of Chang cells was mediated by apoptotic death signal processes. The phosphotransferase activity of JNK1 remained in a basal level in Chang cells which was treated individually with the adriamycin and ethanol extract of herb. However, it was markedly increased in Chang cells which was cotreated with adriamycin and ethanol extract of herb. In addition, the expression of Fas and FasL was markedly induced by the cotreatment of adriamycin and herb extract. For a while, the expression of Sax was a eminently increased by the ethanol extract of herb. However, Scl2 expression was not affected by the individual or cotreatment of adriamycin and herb extract. Conclusions : our results suggest that the cotreatment of adriamycin aM ethanol extract of herb induces synergistic apoptotis of human liver origin Chang cells via the upregulation of JNK, Fas, FasL and Bax.