• Asian Pacific Journal of Cancer Prevention
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• v.17 no.5
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• pp.2453-2457
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• 2016

Background: Dysregulation of HSP90 gene expression is known to take place in breast cancer. Here we used D,L-lactic-co-glycolic acid-polyethylene glycol-17-dimethylaminoethylamino-17-demethoxy geldanamycin (PLGA-PEG-17DMAG) complexes and free 17-DMAG to inhibit the expression of HSP90 gene in the T47D breast cancer cell line. The purpose was to determine whether nanoencapsulating 17DMAG improves the anti-cancer effects as compared to free 17DMAG. Materials and Methods: The T47D breast cancer cell line was grown in RPMI 1640 supplemented with 10% FBS. Encapsulation of 17DMAG was conducted through a double emulsion method and properties of copolymers were characterized by Fourier transform infrared spectroscopy and H nuclear magnetic resonance spectroscopy. Assessment of drug cytotoxicity was by MTT assay. After treatment of T47D cells with a given amount of drug, RNA was extracted and cDNA was synthesized. In order to assess HSP90 gene expression, real-time PCR was performed. Results: Taking into account drug load, IC50 was significant decreased in nanocapsulated 17DMAG in comparison with free 17DMAG. This finding was associated with decrease of HSP90 gene expression. Conclusions: PLGA-PEG-17DMAG complexes can be more effective than free 17DMAG in down-regulating of HSP90 expression, at the saesm time exerting more potent cytotoxic effects. Therefore, PLGA-PEG could be a superior carrier for this type of hydrophobic agent.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.152-152
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• 2003

As utilization of radiation in medicine, industry and biochemical research increases, the protection against radiation damage has become an important issue. Natural products such as herbal medicines are beginning to receive attention as modifiers on the radiation response. In the present study, the protective effect of a herb, Menthae Herba, against radiation-induced DNA damage was evaluated using alkaline single-cell gel electrophoresis (SCGE; comet assay) in the mouse peripheral blood Iymphocytes and the micronucleus formation test in the Chinese hamster ovary (CHO) cells. The tail moment, which was a marker of DNA damage in the SCGE, and the frequency of micronuclei was decreased in groups treated with Mentae Herba extract before exposure to 200 cGy of gamma-ray. We also confirmed its activities to scavenge DPPH and hydroxyl radicals. These experiments demonstrated that Menthae Herba was effective at reducing the radiation-induced damage of DNA and scavenging free radicals. It is plausible that scavenging of free radicals by Menthae Herba may have played an important role in providing the protection against the radiation-induced damage to the DNA. These results indicated that Menthae Herba might be a useful radioprotector and that radical scavenging appears to be one of the mechanisms of radiation protection.

• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.1025-1035
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• 2017

In this study, the hot water extract from Mulberry (Morus alba) Leaves fermented with Hericium erinaceum mycelium (MA-HE) was assessed for antioxidant activity. Radical scavenging activity of MA-HE evaluated using 2,2-diphenyl-1-picrylhydrazyl(DPPH) radical and 2,2'-azino-bis(3-ethyl-benzothiazoline-6-sulfonic acid)(ABTS) radical. MA-HE showed 63% DPPH radical scavenging activity at $500{\mu}g/mL$ and 98.27% ABTS radical scavenging activity at $250{\mu}g/mL$. MA-HE was shown to significantly inhibited DNA strand breakage induced by free radical. MA-HE also inhibited free radical-mediated human serum albumin modification. MA-HE effectively inhibited $H_2O_2$ induced cell death and significantly increased of the 8% cell survival at $100{\mu}g/mL$. MA-HE decreased intracellular reactive oxygen species (ROS) levels in $H_2O_2$-treated cells. The results suggested that MA-HE can contribute to antioxidant and protected cells from oxidative stress-induced cell injury.

• The Korean journal of helicobacter and upper gastrointestinal research
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• v.18 no.3
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• pp.150-156
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• 2018

Precision medicine stands for 4Ps - precise, preventive, participatory, and personal; in which "precision" is important because the current modern medicine starts from "trial and error," and "one does not fit all". Current targeted therapies for cancer have changed treatment approaches and led the precision medicine; however, clinical use of liquid biopsy, using blood or other liquid specimens to characterize circulating tumor cells (CTC) or tumor genes instead of biopsies of tumor tissues, still awaits availability of more information regarding non-invasive cancer detection and characterization, prediction of treatment response, monitoring the disease course and relapse possibilities, identification of mechanisms of drug resistance, and newer pathogenesis. In this review, we will introduce the basic concept of CTC, circulating cell free DNA, and exosomes and their possible application for gastric cancer relevant with Helicobacter pylori infection.

• Journal of Life Science
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• v.23 no.1
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• pp.31-37
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• 2013

The present study aimed to investigate effects of ethanol extracts from Hydropsyche kozhantschikovi on cell and DNA damage caused by oxidative stress. In a radical scavenging assay, compared with ascorbic acid used as a control, the level of DPPH (1,1-diphenyl-2-picrylhydrazyl) and that of hydroxyl radicals in H. kozhantschikovi extracts were 60.0% and 43.7%, respectively. The ferrous iron chelating level was 37.5% compared to the chelating value of EDTA (ethylenediaminetetraacetic acid) as a positive control at the same concentration. To verify inhibitory effects of oxidative cell damage induced by reactive oxygen species (ROS), the relative level of lipid peroxidation and the expression level of the p21 protein were compared in extracts-treated and untreated groups. Lipid peroxidation was completely inhibited in the extracts-treated group compared with the radical-only treated group. The level of p21 protein expression was restored to 92.2% of p21 protein expression in the control sample. In addition, DNA cleavage inhibition in the H. kozhantschikovi extracts was 74.1% compared with that of the control group, suggesting that H. kozhantschikovi extracts repress DNA cleavage induced by ROS. Moreover, the phosphorylation ratio of the H2AX protein was 16.7% in the radical-treated group, indicating that the ethanol extracts inhibited 83.3% of DNA damage. Our findings suggest that ethanol extracts from H. kozhantschikovi are effective not only in repressing the oxidation of free radicals and highly toxic hydroxyl radicals, but also in decreasing cell and DNA damage caused by oxidative stress.

• Korean Journal of Acupuncture
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• v.27 no.2
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• pp.13-24
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• 2010

Objectives : Ulcerative colitis is a chronic relapsing inflammatory disease in the gastrointestinal tract. We investigated whether Aurantii fructus immaturus (AFI) pharmacopuncture has antioxidative and anti-inflammatory effects. Methods : in vitro experiments, 1,1-diphenyl-2-picryl hydrazyl (DPPH) free radical scavenging activity, superoxide dismutase (SOD) activity, prevention on $H_2O_2$-induced cell death in RAW264.7 cell line, DNA fragmentation, and cyclooxygenase-2 mRNA expression induced by lipopolysaccharide (LPS), were analyzed to investigate antioxidative and anti-inflammatory effect of AFI pharmacopuncture. in vivo experiment, a murine model of dextran sulfate sodium (DSS)-induced colitis was used to examine the effect of AFI pharmacopuncture on CV12 at different doses of 5 ${\mu}l$, 0.5 ${\mu}l$, 0.05 ${\mu}l$ for 10 days. Body weight, colon length and macroscopic features were investigated. Results : AFI pharmacopuncture showed DPPH free radical scavenging and SOD active effects in a dose-dependent manner. AFI pharmacopuncture showed a protective effect against $H_2O_2$-induced cell injury and also attenuated LPS-induced COX-2 mRNA expression. In a DSS- induced colitis murine model, however, AFI pharmacopuncture at CV12 had no anti-inflammatory effects. Conclusions : The present results suggest that AFI pharmacopuncture extract may have anti- inflammatory and antioxidative effects in vivo test, but further research on the underlying mechanism is required.

• Journal of Korean Ophthalmic Optics Society
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• v.4 no.1
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• pp.1-6
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• 1999

The corneal epithelium is constantly shed and apoptosis may play an important role in this turn-over. We sought to define that serum-free medium was able to induce apoptosis of corneal epithelial cells. SV-40 transfected human corneal epithelial(HCE) cells were grown to 70% confluency in culture. Serum-free medium was added to cells and the cells incubated for 1, 2, 3, or 6 days. Apoptosis of cells at different times was assessed by staining cells with Giemsa or Hoechst 33342 and measuring DNA fragmentation using the TUNEL assay. HCE cells exposed to serum-free medium demonstrated a high incidence of apoptosis, which increased over time to $50{\pm}4%$ after 3 days. They also stained positively with TUNEL assay. Serum-free medium caused time dependent apoptosis of HCE cells. Thus, serum-like nutrient might be important in corneal epithelial cell homeostasis.

• Journal of Life Science
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• v.24 no.10
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• pp.1078-1084
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• 2014

Here, we showed that Acanthocoris sordidus extract inhibited both cell and DNA damage caused by oxidative stress. In a radical scavenging assay, the scavenging activity of the A. sordidus extract against 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radicals was 48.9% and 37.8%, respectively, that of ascorbic acid, which was used as a positive control. The ferrous iron chelating activity of the A. sordidus extract was 80.0% compared to that when ethylenediaminetetraacetic acid (EDTA) was used a control. To verify the inhibitory effect of the extract on oxidative cell damage induced by reactive oxygen species (ROS), a lipid peroxidation assay was performed. The results showed that peroxidation was completely inhibited in an extract-treated group compared to a radical-treated group. The level of p21 protein expression was 68.1% that of a control sample. The DNA cleavage-inhibiting property of the A. sordidus extract-treated group was 53.3% that of a control group. Moreover, the phosphorylation of the H2AX protein was reduced to 39.0% of that treated with radical agents, indicating that the extract might inhibit the DNA damage that causes radical oxidation. Taken together, our findings suggest that the A. sordidus extract is effective not only in repressing oxidation by free oxygen radicals and hydroxyl radicals but also in decreasing cell and DNA damage caused by oxidative stress.

• Nutritional Sciences
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• v.5 no.4
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• pp.175-183
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• 2002

To compare the effects of various types of dietary fiber on microbial production of short-chain fatty acids (SCFA) and on colon cell proliferation which is used as an intermediate biomarker for colon carcinogenesis, groups of 10 male Sprague-Dawley rats were fed one of four fiber-supplemented diets (6% cellulose, 6% pectin, 6% polydextrose, and a mixture of 3% cellulose and 3% polydextrose) for three weeks. As a control, a fiber-free diet was fed to a separate group of 10 rats. Cell proliferation was measured by in vivo incorporation of bromodeoxyuridine into DNA in the proximal and distal colon, respectively. Luminal concentrations of SCFA were measured by gas chromatography. Dietary fiber significantly influenced microbial production of SCFA in the colon; pectin supplementation produced the highest concentrations of luminal SCFA in both the proximal and distal colon (p<0.05). The degree of individual SCFA production was characterized by a relatively higher increase in butyrate production by the pectin-supplemented diet, and in propionate production by the polydextrose-supplemented diet, resulting in alterations of the molar ratios of acetate, propionate and butyrate. There were significant differences in colon cell proliferation among the diet groups; the pectin-supplemented diet produced a significantly higher effect on cell proliferation of distal colonic epithelial cells (p＜0.05), and the polydextrose-supplemented diet produced an intermediate effect compared to the fiber-free or cellulose-supplemented diet. Increased cell proliferation was correlated to increased luminal concentrations of butyrate in the proximal colon and to increased luminal concentrations of propionate and butyrate in the distal colon (p<0.05). Therefore, these data suggest that dietary fiber may modulate colon cell proliferation by altering luminal SCFA concentrations, particularly butyrate and perhaps propionate. In addition, the present study is the first finding that has demonstrated a relative increase in colon cell proliferation due to supplementation with polydextrose, suggesting that the overuse of this artificially synthesized polysaccharide in food processing technology needs to be carefully evaluated from the public health point of view.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.1
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• pp.22-27
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• 2004

In the present study, the protective effects of Artemisia capillaris (AC) on the DNA damage induced by $^{60}$ Co ${\gamma}$-rays were evaluated using alkaline single-cell gel electrophoresis (SCGE, comet assay) in the mouse peripheral lymphocytes and micronuclei (MN) formation test in the Chinese hamster ovary (CHO) cells. We also investigated the effect of AC on 8-hydroxy-2'-deoxyguanosine (8-OHdG) formation in the mouse liver and thymus exposed to ${\gamma}$-ray, The tail moment and the frequency of MN, which were markers of DNA damage in the SCGE and MN formation test, were decreased in the groups treated with AC extract before exposure to 200 cGy of ${\gamma}$-ray. We also observed its activities, lowering 8-OHdG level, an index of oxidative DNA damage, in the groups treated with AC extract before whole body ${\gamma}$-irradiation (800 cGy). It is plausible that scavenging of free radicals by AC may have played an important role in providing the protection against the radiation-induced damage to the DNA. These results indicated that AC protects the DNA damage induced by ${\gamma}$-rays and might be a useful radioprotector, especially since it is a relatively nontoxic product.