• Journal of agriculture & life science
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• v.44 no.4
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• pp.45-55
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• 2010

In this study, the acetylcholinesterase (AChE) inhibition and neuronal cell protective effects of water, 100% methanol and dichlromethane extracts from garlic were investigated. We found that dichloromethane extract of garlic resulted in a dose-dependent manner on AChE inhibition ($IC_{50}$: $36.1{\mu}g/mL$). In cell viability assay using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide (MTT), cell viabilities of water, 100% methanol and dichlromethane extracts were lower (almost under 40%) than amyloid ${\beta}$ protein ($A{\beta}$)-induced neurotoxicity. Because $A{\beta}$ is also known to increase neuronal cell membrane breakdown, neuronal apoptosis was further confirmed by lactate dehydrogenase (LDH) and neutral red uptake (NRU) assay. Water extract presented relative protection against $A{\beta}$-induced membrane damage in LDH assay. However all garlic extracts showed significant problem with decrease of cell viability in NRU assay, especially at dichloromethan extract. To determine active compounds in column fractions (98:2 fraction) from dichloromethane extract which showed significant AChE inhibitory effect, we performed HPLC and LC-MS analysis. It was supposed that garlic may contain allyl methyl disulfide, diallyl monosulfide, and diallyl disulfide as active compounds.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.34 no.3
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• pp.189-200
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• 2008

In this study, the antioxidative effects, inhibitory effects on elastase, and components of Quercus glauca extracts were investigated. The free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity $(FSC_{50})$ of extract I fractions of Quercus glauca leaf was in the order: 50% ethanol extract $(12.45{\mu}g/mL)$ < ethyl acetate fraction $(10.47{\mu}g/mL)$ < deglycosylated flavonoid aglycone fraction $(8.57{\mu}g/mL)$. Reactive oxygen species (ROS) scavenging activities $(OSC_{50})$ of some Quercus glauca leaf extracts on ROS generated in $Fe^{3+}-EDTA/H_2O_2$ system were investigated using the luminol-dependent chemiluminescence assay. The order of ROS scavenging activity was 50% ethanol extract $(OSC_{50},\;4.2{\mu}g/mL)$ < deglycosylated flavonoid aglycone fraction $(1.58{\mu}ug/mL)$ < ethyl acetate fraction $(0.66{\mu}g/mL)$. Ethyl acetate fraction showed the most prominent scavenging activity. The protective effects of extract / fractions of Quercus glauca leaf on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The Quercus glauca leaf extracts suppressed photohemolysis in a dose dependent manner, particularly deglycosylated flavonoid aglycone fraction exhibited the most prominent celluar protective effect $({\tau}_{50}$, 398.67 min at $50{\mu}g/mL$). Aglycone fractions obtained from the deglycosylation reaction of ethyl acetate fraction among the Quercus glauca leaf extracts, showed 2 bands in TLC and 2 peaks in HPLC experiments (360 nm) as well. Two components were identified as quercetin (55.77%), and kaempferol (44.23 %). TLC chromatogram of ethyl acetate fraction of Quercus glauca leaf extracts revealed 6 bands $(QG1{\sim}QG6)$, Among them, isoquercitrin (QG3), hyperin (QG4), and rutin (QG6) were identified. The inhibitory effect of aglycone fraction on tyrosinase $(IC_{50},\;73.5{\mu}g/mL)$ and elastase $(IC_{50},\;16.2{\mu}g/mL)$ was high. These results indicate that extract / fractions of Quercus glauca can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging $^1O_2$ and other ROS, and protect cellular membranes against ROS. And component analysis of Quercus glauca leaf extract and inhibitory activity on tyeisinase and elastase of the aglycone fraction could be applicable to new functional cosmetics.

• Food Science and Preservation
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• v.18 no.3
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• pp.374-382
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• 2011

Aflatoxin ($AFB_1$) is a potent hepatotoxic and hepatocarcinogenic mycotoxin in humans. It is also well-known to be accumulated in animal tissues via various metabolic pathways. This study was conducted to determine the effects of vitamin C on the residual $AFB_1$ in rat sera that were treated with radiation and $AFB_1$. Six week-old male Sprague-Dawley rats were randomly divided into five groups: a control group, $AFB_1$-treated group, the group treated with $AFB_1$ and vitamin C, the group treated with X-ray and AFB1, and the group treated with X-ray and $AFB_1$ with vitamin C. On the first day of the experiment, only one dose of X-rays was exposed to the entire liver at 1,500 cGy. Next, vitamin C was injected at 10 mg/kg body weight via intraperitoneal injection, followed 1 hr later by the administration of 0.4 mg/kg of $AFB_1$ via intraperitoneal injection. These treatments were then administered every three days over a period of 15 days. On the 16th day of treatments, the animals were sacrificed. The contents of $AFB_1$ in rat sera were determined via indirect competitive ELISA and HPLC method. In the quantitative analysis of $AFB_1$ in rat sera via ELISA, $5.17{\pm}0.34$ ng/mL of $AFB_1$ was detected in the $AFB_1$-treated groups, but the amount more significantly decreased to $3.23{\pm}0.76$ ng/mL in the groups treated with $AFB_1$ and vitamin C (p<0.01) than in the $AFB_1$-treated groups. The $AFB_1$ contents of the rat sera of the groups treated with X-ray and $AFB_1$ did not significantly decreased with the administration of vitamin C. The $AFB_1$ content of the rat sera that was analyzed via HPLC showed a tendency similar to that of the content that was analyzed via ELISA. With regard to these data, vitamin C was very effective in reducing $AFB_1$ residue in rat sera.

• Journal of Sericultural and Entomological Science
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• v.20 no.2
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• pp.10-14
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• 1978

There are relatively many reports have been issued on he active movement of cuticle of larva. which tend to protect their body, however, only a few reports have been disclosed on the cuticle of pupal body except the small portion of rectangle which shown tortoise-shell shape. In this connection, many portion of the external structure of pupal cuticle has been studied and the following. results were found: 1) No. spot of rectangle which is sculptured in the surface of cuticle that born by branching. out of the development of cell in imaginal bud of antenna and head were found. However, in the compound eye of net shaped sculpture was found in the (equation omitted) shaped parts which holding. the diameter of about 8u and the surrounding area has the small bump and the one is dark brown coloured comparing with shape. 2) The sculpture shape of thorax is a little different than in the head. However, (equation omitted) portion is varies from the segment to segment. In general, it is not very clear than the compound eye in the head, the dark brown bump shape is slowly fade a from the prothorax, mesothorax to metathorax. 3) The surface of intersegment membrane is colourless or slightly yellow, and the entire surface has stripped marking with thine lines. 4) In the abdominal segment, there are many and small sculptures in net shape around the (equation omitted) shape portions. 5) The size of sculpture in (equation omitted) portion of abdomen is smaller than one in thorax, and in the same segment, the dorsal is smaller than abdomen and the rear portion of the segment is larger than the front of segment. 6) After the 7th abdominal segment, no intersegmental membrane is found and the cuticle of the external structure is the same as external structure of the segment. 7) The seta is not found in head, compound eye, antenna and wing which portions were subdivided by development of imagined bud of the cell, no seta is found in cuticle of the segment in the general cell of the larva stage and also in the dorsal and intersegmental membrane.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.3
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• pp.134-144
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• 2003

A rhizobacterium Pseudomonas cholororaphis O6 produced several secondary metabolites, such as phenazines, protease, and HCN that may be involved in inhibition of the growth of phytopathogenic fungi. In field study, P. chlororaphis O6 treatment on wheat seed suppressed root rot disease caused by Fusarium culmorum. The major organic acids of cucumber root exudates were fumaric acid, malic acid, benzoic acid, and succinic acid. Glucose and fructose were major monosaccharides in cucumber root exudates. The total amount of organic acids was ten times higher than that of the sugars. P. chlororaphis O6 grew well on cucumber root exudates. The dctA gene of P. chlororaphis O6 consisted of a 1,335 bp open reading frame with a deduced amino acid sequence of 444 residues, corresponding to a molecular size of about 47 kD and pI 8.2. The deduced dctA sequence has ten putative transmembrane domains, as expected of a membrane-embedded protein. Our results indicated that organic acids in cucumber root exudates may play an important role in providing nutrient source for root colonization of biological control bacteria, and the dctA gene of P. chlororaphis O6 may be an important bacterial trait that is involved in utilization of root exudates.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.872-879
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• 2010

Layered copper hydroxides [LCHs, $Cu_2(OH)_3{\cdot}NO_3$] has the agricultural potentials as a fungicide because of its high crystallinity, excellent anion exchange capacity, and its regular layered particle size. The study, for the first time, has synthesized LCHs in highly concentrated solution and evaluated its physicochemical properties including the crystallinity and suspension stability. Optimal synthetic condition of LCHs was determined by crystallinity and stability of suspension as follow; 1) concentrations of $Cu(NO_3)_2$ and NaOH solutions were 3.0 M respectively, 2) reaction temperature and solution pH were $25^{\circ}C$ and 6.0, respectively, and 3) aging time after reaction was 2hr. Crystallinity of LCHs enhanced with increase in pH up to 9.0. Whereas, stability of suspension was decrease by increase in crystal size. Especially, increase in reaction temperature decreased stability of suspension. XRD patterns and SEM images exhibited that LCHs had regular layered particle size with 0.2~0.8 ${\mu}m$ and high crystallinity in optimal synthetic condition. The particle size was increased with increase in reaction temperature and pH. These results showed that LCHs synthesized in highly concentrated solution exhibited high stability of suspension as well as high crystallinity suitable to their potential as a fungicide.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.448-454
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• 2021

This study was conducted to the effect of low air temperature and light intensity conditions on yield and quality of tomato at the early stage of growth in Korea. Inplastic greenhouses, low temperature and low temperature with shade treatments were performed from 17 to 42 days after plant. Tomato growing degree days were decreased 5.5% due to cold treatment during the treatment period. Light intensity decreased 74.7% of growing degree days due to shade. After commencing treatments, the plant growth decreased by low temperature and low radiation except for height. Analysis of the yield showed that the first harvest date was the same, but the yield of the control was 3.3 times higher than low temperature with shade treatment. The cumulative yields at 87 days after transplanting were 1734, 1131, and 854 g per plant for control, low temperature, and low temperature with shade, respectively. The sugar and acidity of tomatoes did not differ between treatment and harvesting season. To investigate the photosynthetic characteristics according to the treatment, the carbon dioxide reaction curve was analyzed using the biochemical model of the photosynthetic rate. The results showed that the maximum photosynthetic rate, J (electric transportation rate), TPU (triose phosphate utilization), and R_d (dark respiration rate) did not show any difference with temperature, but were reduced by shading. Vcmax (maximum carboxylation rate) was decreased depending on the low temperature and the shade. Results indicated that low temperature and light intensity at the early growth stage can be inhibited the growth in the early stage but this phenomenon might be recovered afterward. The yield was reduced by low temperature and low intensity and there was no difference in quality.

• Korean Journal of Food Science and Technology
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• v.53 no.4
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• pp.423-433
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• 2021

This study was performed to examine the neuroprotective effect of the ethyl acetate fraction from Eucommia ulmoides oliver leaf (EFEL) on PM_2.5-induced cytotoxicity. EFEL had higher total phenolic and flavonoid contents than the other fractions. In ABTS and DPPH radical scavenging activities, the IC₅₀ of EFEL was measured as 212.80 and 359.13 ㎍/mL, respectively. To investigate the neuroprotective effect of EFEL, MTT and DCF-DA assays were performed on HT22, MC-IXC, and BV-2 cells. EFEL effectively decreased PM_2.5-induced intercellular reactive oxygen species (ROS) content and inhibited PM_2.5-induced cell death. In the results of protein expression related to cellular cytotoxicity on microglial cells (BV-2), EFEL had an improvement effect on cell apoptosis and inflammatory pathways. Rutin and chlorogenic acid were identified as the main physiological compounds. Moreover, it was expected that EFEL, including rutin and chlorogenic acid, could be functional food substances with neuroprotective effects against PM_2.5-induced oxidative stress.

• Journal of Life Science
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• v.29 no.4
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• pp.410-420
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• 2019

Citrus unshiu peel extracts possess a variety of beneficial effects, and studies on their anticancer activity have been reported. However, the exact mechanisms underlying this activity remain unclear. In the current study, the apoptotic effect of ethanol extract of C. unshiu peel (EECU) on human breast adenocarcinoma MDA-MB-231 cells and related mechanisms were investigated. The results showed that the survival rate of MDA-MB-231 cells treated with EECU was significantly inhibited in a concentration-dependent manner, which was associated with the induction of apoptosis. EECU-induced apoptosis was associated with the activation of caspase-8 and caspase-9, which initiate extrinsic and intrinsic apoptosis pathways, respectively, and caspase-3, a representative effect caspase. EECU suppressed the expression of the inhibitor of apoptosis family of proteins, leading to an increased Bax/Bcl-2 ratio and proteolytic degradation of poly (ADP-ribose) polymerase. EECU also enhanced the loss of the mitochondrial membrane potential and cytochrome c release from the mitochondria to the cytosol, along with truncation of Bid. In addition, EECU activated AMP-activated protein kinase (AMPK), and compound C, an AMPK inhibitor, significantly weakened EECU-induced apoptosis and cell viability reduction. Furthermore, EECU promoted the generation of reactive oxygen species (ROS), which acted as upstream signals for AMPK activation as pretreatment of cells, with the antioxidant N-acetyl cysteine reversing both EECU-induced AMPK activation and apoptosis. Collectively, these findings suggest that EECU inhibits MDA-MB-231 adenocarcinoma cell proliferation by activating intrinsic and extrinsic apoptotic pathways, which was mediated through ROS/AMPK-dependent pathways.

• Journal of Life Science
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• v.29 no.3
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• pp.295-302
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• 2019

Liquiritigenin (LG) is a chiral flavonoid isolated from the roots of licorice. It exhibits multiple biological activities including anti-oxidant, anti-cancer, and anti-inflammatory effects. In particular though, the anti-cancer activity of LG in oral squamous cell carcinoma has yet to be elucidated, and LG-induced apoptosis in oral squamous cell carcinoma remains poorly understood. In the present study, we tested the role of LG in inducing apoptosis in oral squamous cell carcinoma cells. LG treatment of HN22 cells resulted in a dose-dependent inhibition of cell viability as detected by a 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide assay. The induction of apoptosis in terms of Annexin V/7-Aminoactinomycin D staining, sub-G1 population, and multi-caspase activity were assessed with a $Muse^{TM}$ Cell Analyzer. Flow cytometric analysis revealed that LG treatment resulted in G2/M arrest in cell cycle progression and downregulation of cyclin B1 and CDC2 expression in a concentration-dependent manner. It also resulted in significant upregulation of p27. In addition, LG was seen to trigger the generation of reactive oxygen species and induce CCAAT/enhancer-binding protein homologous protein and 78-kDa glucose-regulated protein in concentration-dependent upregulation. The LG treatment of HN22 cells led to a loss of mitochondrial membrane potential (${\Delta}{\Psi}m$); it also reduced the levels of anti-apoptotic protein and increased the expression of apoptotic protease activating factor-1, cleaved poly (ADP-ribose)polymerase and Bax. Overall, our results indicate that the pro-apoptotic effects of LG in HN22 cells depend on the activation of both intrinsic and extrinsic signaling pathways. Thus, our results suggest that LG constitutes a natural compound with a potential role as an anti-tumor agent in oral squamous cell carcinoma.