• Journal of the Microelectronics and Packaging Society
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• v.29 no.1
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• pp.71-75
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• 2022

Graphene oxide was stirred with a ZnCl₂:NaCl electrolyte and electrochemically coated by cyclic voltammetry to simplify the electron transpfer layer film forming process for organic solar cells and to fabricate an organic solar cell having it. The device structure is FTO/ZnO:graphene/P3HT:PCBM/PEDOT:PSS/Ag. Morphology and chemical properties of ETL were confirmed by scanning electron microscopy(SEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. As a result of XPS measurement, ZnO metal oxide and carbon bonding were simultaneously confirmed, and ZnO and graphene peaks were confirmed by Raman spectroscopy. The electrical characteristics of the manufactured solar cell were specified with a solar simulator, and the ETL device coated twice at a rate of 0.05 V/s showed the highest photoelectric conversion efficiency of 1.94%.

• Journal of Microbiology and Biotechnology
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• v.16 no.9
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• pp.1399-1404
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• 2006

The roots of Aralia continentalis (AC) have been used traditionally in Korean as a folk medicine for anti-inflammation and as an anti-rheumatic. In this study, we report that the ethyl acetate-soluble traction (ACE) of the methanolic extract of AC root inhibited the cell growth of various human cancer cell lines and induced apoptosis of HL-60, human promyelocytic leukemia cells. Its $IC_{50}$ values on growth inhibition were estimated to be $56.3{\mu}g/ml$ on HL-60, $87.2{\mu}g/ml$ on HepG2, $93.2{\mu}g/ml$ on HeLa, $135.5{\mu}g/ml$ on DU-145, and $135.8{\mu}g/ml$ on HT-29 cells. Interestingly, ACE showed no antiproliferative effect on normal lymphocyte cells used as control. Furthermore, nuclear DAPI staining revealed the typical nuclear features of apoptosis in the HL-60 cells exposed to $80{\mu}g/ml$ ACE, and a flow cytometric analysis of the HL-60 cells using propidium iodide showed that the apoptotic cell population increased gradually from 5% at 0 h to 16% at 12 h and 20% at 24 h after treated with $50{\mu}g/ml$ of ACE. TUNEL assay also revealed the apoptotic induction of the HL-60 cells treated with ACE. To obtain further information on the ACE-induced apoptosis, the expression level of certain apoptosis-associated proteins was examined using a Western blot analysis. Treatment of the HL-60 cells with ACE resulted in the activation of caspase-3, and subsequent proteolytic cleavage of poly(ADP-ribose) polymerase (PARP). The above results confirmed that the apoptosis in the HL-60 cells was induced by ACE, and that caspase-3-mediated PARP cleavage was involved in the process.

• Korean Journal of Medicinal Crop Science
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• v.20 no.3
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• pp.153-158
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• 2012

In order to develop as a natural source of anticancer materials of Cudrania tricuspidata, the cytotoxicity of methanol extracts by harvesting parts and times against 8 cell lines including 293 (normal kidney cells) and A-431 (epidermoid carcinoma cells) were investigated using MTT assay. All harvesting parts had hardly cytotoxicity against 293. And methanol extracts of stem bark and root bark showed very high cytotoxicities against 7 cancer cell lines. The cytotoxicity was the highest against HeLa (cervix adenocarcinoma cells) and followed by MCF-7 (breast adenocarcinoma cells), AGS (stomach adenocarcinoma cells), HT-29 (colon adenocarcinoma cells), HepG2 (hepatoblastoma cells), A549 (lung carcinoma cells) and A-431. By the way, leaf extract had a cytotoxicity against only AGS and ripe fruit extract had no cytotoxicity. Among harvesting times, the cytotoxicity of root bark were high from April to September but that of stem bark showed a little difference. These results showed that anticancer activities of Cudrania tricuspidata extracts were eventful changes by harvesting parts and times.

• The Journal of Internal Korean Medicine
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• v.31 no.2
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• pp.273-289
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• 2010

Objectives : To investigate the anti-cancer effect of Baekduong-tang(BDOT) against cancer cells, the signaling pathway of apoptosis was explored in human colon cancer cells. Materials and Methods : Human colon cancer cell lines, including HT-29 and HCT-116 cells, were used. Cell viability was measured by MTT assay. Apoptosis was determined by DAPI nuclei staining and flow cytometry in HCT-116 cells treated with 0.25 mg/$m{\ell}$ Baekduong-tang for 48 hrs. Results : Baekduong-tang induced the apoptosis of p53 positive HCT-116 cells with G2/M phase arrest. Treatment with Baekduong-tang led to increased expression and phosphorylation of p53 and decreased expression of CDK2 and CDK6 in HCT-116 cells. It also activated caspase-3 through caspase-10 and caspase-9 activation. Finally, Baekduong-tang induced production $H_2O_2$, superoxide anion ($O_2^-$) and NO and modulated proteins expression including SOD, NOS, Bax and Bcl-2. Conclusions : These results indicate Baekduong-tang induces apoptotic death of HCT-116 cells through G2/M phase arrest and disturbance of intracellular redox status in a p53-dependent manner.

• Korean Journal of Medicinal Crop Science
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• v.22 no.5
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• pp.369-377
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• 2014

In order to find out anticancer activity of Korean pepper (Capsicum annuum L.), the cytotoxicity against 8 cell lines including 293 (normal kidney cells) and A-431 (epidermoid carcinoma cells) of extracts by extraction solvents and plant parts were investigated using MTT assay. Also the correlation between content of capsaicin known as anticancer ingredient and cytotoxicity of extracts from pepper were analyzed. The distilled water extracts from seed and germinated seed showed very high cytotoxicity against 6 cancer cell lines including A549 (lung carcinoma cells), AGS (stomach adenocarcinoma cells), HeLa (cervix adenocarcinoma cells), HepG2 (hepatoblastoma cells), HT-29 (colon adenocarcinoma cells), and MCF-7 (breast adenocarcinoma cells). But 80% ethanol and methanol extracts showed cytotoxicity against 293 and AGS. The $RC_{50}$, that was, the concentration of sample required for 50% reduction of cell viability, of seed and germinated seed extracts against AGS were $33.4{\sim}389.1{\mu}g/m{\ell}$ and $63.9{\sim}1,316.7{\mu}g/m{\ell}$, respectively, so anticancer activity was higher in seed than in germinated seed. In capsaicin contents, seed with high cytotoxicity and pericarp with a little cytotoxicity contained $47.4{\sim}1,260.0{\mu}g/g$ and $58.3{\sim}1,498.0{\mu}g/g$, respectively. As these results, the correlation was not between cytotoxicity and capsaicin content.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.11
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• pp.1371-1376
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• 2007

The effect of Hovenia dulcis Thumb leaves on the mutagenicity in salmonella assay and inhibitory effects on the growth of cancer cells were studied. On antimutagenicity as evaluated by Ames test, the extract and fractions of Hovenia dulcis Thumb leaves had no effect on the mutagenicity by themselves. However, methanol extract and fractions from Hovenia dulcis Thumb showed strong inhibitory effect on the mutagenesis induced by N-methyl-N#-nitro-N-nitroso-guanidine (MNNG) and benzo(a)pyrene (B(a)P). Among the solvent fractions of methanol extract, the hexane, chloroform and butanol fraction exhibited stronger inhibitory activity against MNNG and B(a)P induced mutagenesis than water fraction. For anticancer effects, Hovenia dulcis Thumb loaves extract and fractions against cancer cell lines including HepG2 and HT29 were investigated. The methanol extract, the hexane fraction and the chloroform fraction of Hovenia dulcis Thumb leaves inhibited growth of cancer cells but they had no effect on the cytotoxicity of normal human liver cells under the same conditions.

• Food Science of Animal Resources
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• v.24 no.1
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• pp.86-91
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• 2004

The ability of probiotics containing Lactobacillus acidophilus to adhere to the intestinal epithelium may play an important role in colonization of the gastrointestinal tract and preventing enteric pathogen such as enterohemorrhagic E. coli(EHEC O157:H7. In the study, we investigated the adhesion to human intestinal epithelial cells(HT-29) of strains of L. acidophilus(3 from human, 2 from pig, and 1 from calf). All of the tested strains of L. acidophilus were highly observed adhesion ability(from 10$\^$6/ to 10$\^$7/ cfu/mL), compared to L. rhamnosus GG as control. Also, adhered strains of L. acidophilus were significantly preserved in serial wash-out steps. However, no correlation could be observed between cell surface hydrophobicity and adhesion abilities of the tested strains of L. acidophilus. Inhibition of adhesion of EHEC O157:H7 was also examined, a 2 log cycle reduction was observed by all of the tested strains of L. acidophilus. These results suggest that the strains of L. acidophilus with high adhesion ability are resistant to wash-out and adhesion ability inhibition by selected strains of L. acidophilus helps to prevent adhesion of EHEC O157:H7 to intestinal epithelial cells.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.9
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• pp.1302-1307
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• 2005

In this study, we investigated the anticarcinogenic and antioxidative activities of Rhodiola sachalinensis (RS). Hexane (RSMH), ethylether (RSMEE), ethylacetate (RSMEA), butanol (RSMB), aqueous (RSMA) fractions and methanol extract (RSM) were screened for their growth inhibition effects using 3- (4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay on HepG2, HeLa, MCF-7 and HT-29 cells. The anticarcinogenic effects of RSMEE was most significant when tested on MCF-7 and HepG2 cell lines at the concentration of $500{\mu}g/mL$ which resulted about $84\%\;and\;90\%$ on MCF-7 and HepG2 cells, respectively. The quinone reductase (QR)-inducing activity of RSMH on HepG2 cells was 3.5 times higher compared with the control at the concentration of $200{\mu}g/mL$. Antioxidative activities of RSM, RSMEE, RSMEA and RSMB showed about $80\%$ of electron donating activity (EDA) which were very similar to that of vitamin C as a control. We observed morphological changes of shrinking and the blebbing of HepG2 cancer cell membranes depending on the concentration of RSMEE.

• Archives of Pharmacal Research
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• v.25 no.5
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• pp.718-723
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• 2002

CKD-602 (7-[2-(N-isopropylamino)ethyl]-(20S)-camptothecin) is a recently-developed synthetic camptothecin analogue and currently under clinical development by Chong Kun Dang Pharm (Seoul, Korea). CKD-602 showed potent topoisomerase inhibitory activity in vitro and broad antitumor activity against various human tumor cells in vitro and in vivo in animal models. This study describes the pharmacodynamics of the immediate and delayed cytotoxicity induced by CKD-602 in a human colorectal adenocarcinoma cell line, HT-29, and its intracellular drug accumulation by HPLC. The present study was designed to address whether the higher activity of CKD-602 with prolonged exposure is due to delayed exhibition of cytotoxicity and/or an accumulation of anti proliferative effect on continuous drug exposure. The drug uptake study was performed to determine whether the delayed cytotoxicity is due to a slow drug accumulation in cells. CKD-602 produced a cytotoxicity that was exhibited immediately after treatment (immediate effect) and after treatment had been terminated (delayed effect). Both the immediate and delayed effects of CKD-602 showed a time dependent decrease in 4IC_{50}$ values. Drug uptake was biphasic and the second equilibrium level was obtained as early as at 24hr, indicating that the cumulative and delayed antitumor effects of CKD-602 were not due to slow drug uptake. On the other hand, CKD-602 treatment was sufficient to induce delayed cytotoxicity after 4hr, however, longer treatment (＞24hr) enhanced its cytotoxicity due to the intracellular accumulation of the drug, which requires 24hr to reach maximum equilibrium concentration. In addition, $C^n$$\times$T=h analysis (n=0.481) indicated that increased exposure times may contribute more to the overall antitumor activity of CKD-602 than drug concentration. Additional studies to determine the details of the intracellular uptake kinetics (e.g., concentration dependency and retention studies) are needed in order to identify the optimal treatment schedules for the successful clinical development of CKD-602.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.3
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• pp.311-316
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• 2005

Fermentation properties and in vitro anticancer effect of young radish (YR) kimchi and young radish watery (YRW) kimchi were investigated during fermentation at 5℃. The fermentation of YR kimchi during 2-3 weeks led to the decrease of pH down to pH 4.3, increased acidity, and the highest Leuconostoc sp. counts. YR kimchi showed the acidity of 1.04-1.27% at the pH 4.3, when the kimchi was ripened properly. The fermentation of YRW kimchi during 9 days led to the decrease of pH down to pH 4.3 and the acidity of 0.20%. Inhibitory effects of the juices of YR, YR kimchi, and YRW kimchi on the growth of AGS human gastric adenocarcinoma cells in MTT assay were increased with the added concentration. The juice of YR kimchi had a higher inhibitory effect on the growth of AGS human gastric adenocarcinoma cells than that of YRW kimchi at same concentration. The juice of YR kimchi showed similar inhibitory effects on the growth of AGS human gastric and HT-29 human colon adenocarcinoma cells in MTT assay to baechu kimchi, which the inhibition rates are more than 50%.