• 한국약용작물학회지
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• 제20권4호
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• pp.222-230
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• 2012

We evaluated the inhibitory effects of extracts and components of Geranium thunbergii on aldose reductase (AR) and galactitol formation in rat lenses with high levels of galactose as a part of our ongoing search of natural sources for therapeutic and preventive agents for diabetic complications. The inhibitory effects of water, methanol and ethanol extracts of G. thunbergii on rat lens AR (RLAR) were determined. Comparing inhibitory effects of various solvent extracts, ethanol extract showed RLAR inhibitory activity ($IC_{50}$ values, 5.24 and $6.39{\mu}g/m{\ell}$, respectively). The ethanol extract was fractionated to chloroform, ethyl acetate and water. Of these, the ethyl acetate fraction from ethanol extract of G. thunbergii exhibited RLAR inhibitory activity ($IC_{50}$ value, $2.64{\mu}g/m{\ell}$). In order to identify the bioactive components of ethyl acetate soluble fraction of ethanol extract from G. thunbergii, eight compounds, namely gallic acid (1), protocatechuic acid (2), p-hydroxybenzoic acid (3), brevifolin carboxylic acid (4), geraniin (5), ellagic acid (6), kaempferol-3-O-arabinofuranosyl-7-O-rhamnopyranoside (7), kaempferitrin (8) were isolated. The isolates were subjected to in vitro bioassays to evaluate their inhibitory activity on RLAR and galactitol formation in rat lenses. The ellagic tannins (5, 6) and flavonoid (7) exhibited strong inhibitory effects on RLAR. Also, these three compounds (5, 6 and 7) suppressed galactitol accumulation in rat lens under high galactose conditions, demonstrating the potential to prevent galactitol accumulation exo vivo. These results suggest that the extracts and components of G. thunbergii are a promising agent in the prevention or treatment of diabetic complications.

• 한국환경보건학회지
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• 제35권2호
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• pp.124-129
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• 2009

The photocatalysis degradation of simazine, s-triazine type herbicide was carried out using circulating photo reactor systems. In order to search for the effective method to mineralize this compound into environmentally compatible products, this study compared the removal efficiencies of simazine by changing various parameters. First, under the photocatalytic condition, simazine was more effectively degraded than by photolysis and $TiO_2$ only condition. With photocatalysis, 5 mg/l simazine was degraded to approximately 90% within 30 min, and completely degraded after 150 min. Ionic byproducts such as ${NO_2}^-$, ${NO_3}^-$, and $Cl^-$ were detected from the photocatalysis of simazine, however, the recoveries were poor, indicating the presence of organic intermediates rather than the mineralization of simazine during photocatalysis. Two bioassays using V. fischeri and D. magna were employed to measure the toxicity reduction in the reaction solutions treated by both photocatalysis and photolysis. Simazine and its photocatalysis treated water did not exert any significant toxicity to V. fischeri, marine bacterium. However, the acute toxicity test using D. magna indicates that initial acute toxicity ($EC_{50}$ = 57.30%) was completely reduced ($EC_{50}$ = 100%) after 150 min under both photocatalysis and photoysis of simazine. This results indicates that photocatalysis and photolysis of simazine reduced the acute toxicity through mineralization.

• KSBB Journal
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• 제16권6호
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• pp.554-561
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• 2001

본 연구에서는 느릅나무 뿌리껍질에서 분리한 신규 균주인 Enterobacter sp. SSYL(KCTC 0687BP)을 사용하여 세포밖 당화합물(exopolysaccharide, EPS)을 생산하여, EPS의 면역활성에 의한 항암효과를 실험적으로 제시하였다. EPS는 총당함량이 43.0% 내지 70.8%였으며, 총산성당 함량은 7.1% 내지 11.4%, 총단백질 함량은 19.3% 내지 20.6%로, 분자량은 100,000에서 1,000,000 Da의 당단백질임을 알 수 있었다. EPS의 당구성성분을 보면 glucuronic acid (46.7%), fucose(10.8%), fructose (0.2%), glucose(29.9%), galactose(11.0%)이었고, 이외 미지의 성분이 1.3% 정도였다. EPS의 면역활성 검정에 따르면 EPS는 면역세포의 증식을 자극하는 mitogen역할을 하며, 특히 T 세포에 의한 면역증강효과를 나타내었다. B16 흑색종 이식마우스를 이용한 생체내 면역활성에 의한 항암효과를 관찰한 결과 유의성 있는 항암효과를 나타내었으며, 천연물인 유근피 추출 단백다당체의 결과(3 mg/kg에서 약 140%의 생존연장효과를 보임)와 비교해 볼 때 1/10의 농도인 0.3mg/kg에서 약 138.1%의 비슷한 항암효과를 나타내었다.

• 한국응용곤충학회지
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• 제36권3호
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• pp.264-269
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• 1997

뽕나무하늘소(Apriona germari) 및 왕똥풍뎅이 (Aphodius apicalis) 사충으로부터 4종의 Bacillus thuringiensis를 분리하였다. B. thuringiensis의 편모 항원에 의한 동정 결과, 4종의 분리된 B. thuringiensis 중에서 1종은 darmstadiensis 아종으로 판명되었으나, 나머지 3종은 33종의 어느 B. thuringiensis 편모 항체와도 반응하지 않았다. 분리된 균주의 포자와 내독소 단백질 혼합물을 이용하여 뽕나무하늘소와 왕똥풍뎅이, 누에(Bombyx mori) 및 빨간집모가(Cules pipiens pallens) 유충에 대하여 생물검정한 결과, 이들 분리주들은 검정된 곤충에 대하여 독성을 갖지 않는 것으로 나타났다. 아울러 SDS-PAGE와 agarose gel electrophoresis를 이용하여 분리된 4종의 B. thuringiensis의 내독소 단백질과 plasmid DNA 패턴을 조사한 결과, darmstadiensis와 이미 보고된 20종의 무독성 B. thuringiensis와 차이를 보여 새로운 무독성 균주로 사료된다.

• 한국식품영양과학회지
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• 제41권2호
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• pp.156-160
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• 2012

본 연구에서는 복숭아 유과 과육의 품종에 따른 총 폴리페놀 함량과 항산화능 및 tyrosinase 저해 활성을 알아보고자 하였다. 품종별 복숭아 유과 과육의 총 폴리페놀 함량은 7.24~9.95 mg/g의 함량을 나타내며 마도카에서 가장 낮고 몽부사에서 가장 높았으며, DPPH 및 ABTS radical 소거능에서 몽부사의 radical 소거능이 가장 높게 나타났다. Reducing power에서의 항산화 실험 결과 역시 몽부사에서 가장 높게 나타났으며, tyrosinase 저해 활성에서는 홍백에서 가장 높은 tyrosinase 저해능을 보였으나 6품종간의 유의적 차이는 확인할 수 없었다. 따라서 본 연구 결과에 따라 복숭아 유과과육은 항노화 및 미백활성으로 화장품 산업에서 천연 물질로 잠재적인 기능성을 가지고 있을 것으로 사료된다.

• Toxicological Research
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• 제32권4호
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• pp.289-300
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• 2016

Non-genotoxic carcinogens are substances that induce tumorigenesis by non-mutagenic mechanisms and long term rodent bioassays are required to identify them. Recent studies have shown that transcription profiling can be applied to develop early identifiers for long term phenotypes. In this study, we used rat liver expression profiles from the NTP (National Toxicology Program, Research Triangle Park, USA) DrugMatrix Database to construct a gene classifier that can distinguish between non-genotoxic carcinogens and other chemicals. The model was based on short term exposure assays (3 days) and the training was limited to oxidative stressors, peroxisome proliferators and hormone modulators. Validation of the predictor was performed on independent toxicogenomic data (TG-GATEs, Toxicogenomics Project-Genomics Assisted Toxicity Evaluation System, Osaka, Japan). To build our model we performed Random Forests together with a recursive elimination algorithm (VarSelRF). Gene set enrichment analysis was employed for functional interpretation. A total of 770 microarrays comprising 96 different compounds were analyzed and a predictor of 54 genes was built. Prediction accuracy was 0.85 in the training set, 0.87 in the test set and increased with increasing concentration in the validation set: 0.6 at low dose, 0.7 at medium doses and 0.81 at high doses. Pathway analysis revealed gene prominence of cellular respiration, energy production and lipoprotein metabolism. The biggest target of toxicogenomics is accurately predict the toxicity of unknown drugs. In this analysis, we presented a classifier that can predict non-genotoxic carcinogenicity by using short term exposure assays. In this approach, dose level is critical when evaluating chemicals at early time points.

• Asian Pacific Journal of Cancer Prevention
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• 제17권3호
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• pp.1023-1035
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• 2016

The purpose of this study was to investigate the role of colon cancer stem cells (CSCs) during chemically-induced rat multi-step colon carcinogenesis with or without the treatment with a specific cyclooxygenase-2 inhibitor drug (celecoxib). Two experiments were performed, the first, a short term 12 week colon carcinogenesis bioassay in which only surrogate markers for colon cancer, aberrant crypt foci (ACF) lesions, were formed. The other experiment was a medium term colon cancer rat assay in which tumors had developed after 32 weeks. Treatment with celecoxib lowered the numbers of ACF, as well as the tumor volumes and multiplicities after 32 weeks. Immunohistochemical proliferating cell nuclear antigen (PCNA) labeling indexes LI (%) were downregulated after treatment by celecoxib. Also different cell surface antigens known to associate with CSCs such as the epithelial cell adhesion molecule (EpCAM), CD44 and CD133 were compared between the two experiments and showed differential expression patterns depending on the stage of carcinogenesis and treatment with celecoxib. Flow cytometric analysis demonstrated that the numbers of CD133 cells were increased in the colonic epithelium after 12 weeks while those of CD44 but not CD133 cells were increased after 32 weeks. Moreover, aldehyde dehydrogenase-1 activity levels in the colonic epithelium (a known CSC marker) detected by ELISA assay were found down-regulated after 12 weeks, but were up-regulated after 32 weeks. The data have also shown that the protective effect of celecoxib on these specific markers and populations of CSCs and on other molecular processes such as apoptosis targeted by this drug may vary depending on the genetic and phenotypic stages of carcinogenesis. Therefore, uncovering these distinction roles of CSCs during different phases of carcinogenesis and during specific treatment could be useful for targeted therapy.

• 한국환경농학회지
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• 제29권3호
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• pp.239-246
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• 2010

Aphids are one of the major pests in agricultural crops. A number of synthetic pesticides have been used for control of aphids in agriculture, but increasing public concerns over their adverse effects on the environment have required more environmentally-friendly methods for pest management. In this study, we examined plant oil formulations for the control of green peach aphid (Myzus persicae). Oil formulations were prepared by hydrolyzing the plant oils in ethanolic KOH solution and diluted at the rate of 1:500 for aphid control. The oil formulations showed aphid mortalities ranging from 24.44 to 43.33% in vitro. Significantly increased aphid mortalities were observed by the treatment of oil formulations combined with low-dosed imidacloprid. No significant difference in the aphid mortality was observed between the oil formulations. Mass spectrometry analyses of aphids treated with the low dosedimidacloprid plus the plant oil formulations detected similar concentrations of imidacloprid between the treatments. In field trial bioassays against aphids, significantly decreased aphid population were observed in the pepper plants treated with soybean oil formulation combined with the low-dosed imidacloprid, while aphid population dramatically increased in the pepper plants treated with the low-dosed imidacloprid alone. These results suggested that the plant oil formulations can be used as an environmentally-friendly method for enhancing the insecticidal effectiveness, which may play a role in reducing the use of synthetic pesticide in agriculture.

• Biomolecules & Therapeutics
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• 제15권4호
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• pp.205-211
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• 2007

The fruits and stems of Opuntia ficus-indica var. saboten have been reported to exhibit a variety of pharmacological actions, including antioxidant, analgesic, anti-inflammatory, and anti-ulcer effects. In the present study, we evaluated effects of the butanol fraction (SK OFB901) prepared from the 50% ethanol extract of the stems on various types of neuronal injuries induced by oxidative stress, excitotoxins, and amyloid ${\beta}\;(A_{\beta})$ in primary cultured rat cortical cells. Its antioxidant and radical scavenging activities were also evaluated by cell-free bioassays. We found that SK OFB901 strongly inhibited the oxidative neuronal damage induced by $H_2O_2$ or xanthine/xanthine oxidase. In addition, it exhibited marked inhibition of the excitotoxic neuronal damage induced by glutamate, N-methyl-D-aspartic acid, or kainate. Furthermore, the $A_{\beta(25-35)}$-induced neurotoxicity was also significantly attenuated by SK OFB901. It was found to inhibit lipid peroxidation initiated by $Fe^{2+}$ and L-ascorbic acid in rat brain homogenates and scavenge 1,1-diphenyl-2-picrylhydrazyl free radicals. These results indicate that the butanol fraction prepared from the stems of Opuntia ficus-indica var. saboten exerts potent antioxidant and neuroprotective effects through multiple mechanisms, implying its potential applications for the prevention or management of neurodegenerative disorders associated with oxidative stress, excitotoxicity, and $A{\beta}$.

• 한국잡초학회지
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• 제10권3호
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• pp.221-226
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• 1990

상치의 생물검정(生物檢定)을 통(通)해 독활로부터 생장억제물질(生長抑制物質)을 분해(分解) 동정(同定)한 결과(結果) Tlc상에서 $R_f$ 0.51로 나타났으며 이 물질(物質)은 상치생체중(生體重)을 70% 억제(抑制)하였으며 3% $FeCl_3$(0.5N HCL) 시약(試藥)에 검푸른 반응(反應)을 보여 phenol성(性) 물질(物質)로 확인(確認)되었고 324nm에서 가장 높은 UV 흡수대가 나타났고 IR spectrum에서 $3,600cm^{-1}$에서 OH기, $1,700cm^{-1}$에서 C=0, $1,600cm^{-1}$에서 C=C, $1,200cm^{-1}$에서 C-0결합(結合)이 확인(確認)되었다. HPLC에 의한 동정(同定) 결과(結果) retention time 25분(分)대의 ferulic acid($C_{10}H_{10}O_4$)와 일치(一致)하여 독활의 주(主) 억제물질(抑制物質)이 ferulic acid임을 확인(確認)하였다.