• Journal of Life Science
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• v.20 no.6
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• pp.877-884
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• 2010

We investigated the growth inhibitory effect of internal organs of Aplysia kurodai (AK) on proliferation in cancer cell lines in vitro. The internal organs of AK were extracted with methanol (AKM), which were then further fractionated into four subfractions by using solvent partition method, resulting in hexane (AKMH), methanol (AKMM), butanol (AKMB), and aqueous (AKMA) soluble fractions. We determined the cytotoxic effect of these four fractions in four kinds of cancer cell lines - HepG2, MCF-7, HT29 and B16-F10 - by MTT assay. Among the four subfractions of AKM, AKMM showed the strongest cytotoxic effects on all cancer cell lines which were used. Morphological changes such as membrane shrinking and blebbing of cells were also observed in AKMM treatment in HepG2 cells. In addition, we also observed quinone reductase (QR) induced effect in the methanol layer (AKMM) of HepG2 cells. AKMM showed the highest induction activity of quinone reductase on HepG2 cells among the partition layers. The QR induced effect of AKMM was determined to be 2.4 at $100\;{\mu}g/ml$ level with a control value of 1.0. Although further studies are needed, the present work suggests that internal organs of Aplysia kurodai (AK) may be a chemopreventive agent for the treatment of human cells.

• Journal of Life Science
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• v.18 no.1
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• pp.52-57
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• 2008

Xylan is a major hemicellulose component of the cell walls of monocots and hardwood, representing up to 30% of the dry weight of these plants. To efficiently hydrolyze xylan, the endoxylanase gene from Bacillus sp. was expressed in B. subtilis DB431 by introducing the plasmid pJHKJ4. The total activity of the recombinant endoxylanase reached about 857 unit/ml by batch fermentation of B. subtilis DB431/pJHKJ4 in LB maltose medium. The majority (>92%) of endoxylanase was efficiently secreted into the culture medium. The recombinant endoxylanase hydrolyzed more the birchwood xylan efficiently than the other xylans. When 4 % concentration of xylan was used, the highest production of xylooligosaccharide was observed, and xylobiose and xylotriose were the major products. Optimal amount of enzyme and reaction time for producing xylooligosaccharide were found to be 10 unit and 1 hr, respectively. In addition, the temperature of $40^{\circ}C{\sim}50^{\circ}C$ gave the highest production of xylooligosaccharide. Consequently, the optimized conditions for the production of xylooligosaccharide through the hydrolysis of xylan were determined as follows: 10 unit endoxylanase, $50^{\circ}C$, 4% birchwood xylan, 1 hr reaction.

• Journal of Life Science
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• v.21 no.9
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• pp.1219-1225
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• 2011

Phytochemicals, non-nutrient chemicals derived from plants, have been shown to have anti-inflammation, anti-oxidation, and chemopreventive effects. In the current study, we investigated whether five different phytochemicals (resveratrol, genistein, epicatechin gallate, diallyl disulfide, and caffeic acid phenethyl ester) alter cell growth and gene expression in human colorectal cancer HCT116 cells. Using a cell viability assay, we found that each of the phytochemicals tested inhibited HCT116 cell growth in a dose-dependent manner. Additionally, using human oligo DNA microarray analysis, we found that only six genes were commonly up-regulated and seven genes were commonly down-regulated in response to each phytochemical treatment. For the commonly up-regulated genes, the microarray analysis was confirmed by reverse transcription.PCR using gene-specific primers. In addition, NAG-1 protein was up-regulated by all treated phytochemcials. The results of this study may help to enhance our understanding of the general molecular mechanisms of chemoprevention that are mediated by phytochemicals in human colorectal cancer.

• The Korean Journal of Pesticide Science
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• v.15 no.1
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• pp.28-35
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• 2011

The investigation of 218 residual pesticides for 19 types of tea (persimmon leaf tea, chrysanthemum tea, green tea, lavender tea, rosemary tea, dandelion leaf tea, puer tea, mulberry leaf tea, hydrangea leaf tea, jasmine tea, nuomixiang tea, buckwheat tea, mugwort tea, lotus leaf tea, oolong tea, longjing tea, rose tea, tiehkwanyin tea and huoguo tea) obtained from markets in Ansan and Suwon was carried out to assess the risk for residual pesticides in tea. The detection rate was 23.1 % (19 samples of total 65 tea samples) and the detected pesticides were 15 pesticides, such as bifenthrin, bromopropylate, chlorpyrifos, cyhalothrin, cypermethrin, chlorfenapyr, dicofol, endosulfan, fenpropathrin, fludioxonil, fenvalerate, iprobenfos, isoprothiolane, tetradifon and triazophos. The range of concentrations for the detected residual pesticides was 0.01 to 1.24 mg/kg which showed below their maximum residue limits (MRL), but the residual concentration of bifenthrin in a puer tea showed above the legal limit of 0.3 mg/kg. The result of risk assessment of residual pesticides for the detected 15 samples showed that EDI (estimated daily intake) of the pesticides detected ranged 0.0001~0.0844% of their ADI (acceptable daily intake).

• Journal of Life Science
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• v.21 no.2
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• pp.251-256
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• 2011

EGCG, catechins in green tea, is a kind of phytochemical. Through the regulation of signal pathways, EGCG has been known to show anti-oxidant and anti-tumor effects in cells. In this study, we investigated the apoptotic effects of EGCG through AMP-activated protein kinase (AMPK) signal pathways, including hypoxia inducible factor-1 alpha (HIF-$1{\alpha}$). The experiments were performed in B16F10 melanoma cells in a hypoxic state. AMPK is activated by ATP consumption such as nutrient deficiency, exercise, heat shock, etc. The activated AMPK that plays an important role as an energy sensor inhibits proliferation of cancer cells, as well as inducing apoptosis. HIF-$1{\alpha}$, the primary transcriptional regulator of the response to oxygen deprivation, plays a critical role in modulating tumor growth and angiogenesis in a hypoxic state. The apoptotic effects of EGCG were studied in B16F10 cells in a hypoxic state. The results show that EGCG inhibits the transcriptional activity of HIF-$1{\alpha}$ and induces apoptosis. These observations suggest that EGCG may exert inhibitory effects of angiogenesis and control tumor cell growth in hypoxic melanoma cells.

• Journal of Life Science
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• v.12 no.1
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• pp.96-105
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• 2002

To investigate expression of the artificial gene encoding a repeated tripeptide lysyl-glutamyl-tryptophan in tobacco plant, the plant binary vector, pART404 has been constructed, which contains the duplicated CaMV 35S promoter, an artificial gene coding for repetitive polymer (Lys-Glu-Trp)$_{64}$, and nopaline synthase (nos) terminator. The recombinant expression vector was introduced in Nicotiana tabacum (var. Xanthi) via Agrobacterium tumefaciens-mediated trans-formation. The transgenic calli selected by kanamycin containing medium were then regenerated to whole plants. Southern blot analysis indicated that five transgenic plants (No. 1, 7, 9, 43, 45) showed the hybridizing signals at 1.1 kb of the expected size on EcoRI digestion and each of the transgenic plants contained 1 or 3 copies of the artificial gene inserted into its genome. By northern blot analysis, the size of the hybridized total RNA was estimated to be approximately 1.2 kb and the RNA appeared generally to have the integrity. Western blot indicated that the protein was detected at the position of 33 kDa and the expression level of the polypeptide in the transgenic plant (No. 45) was measured to approximately 0.1% of the total protein.

• Applied Biological Chemistry
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• v.50 no.4
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• pp.352-357
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• 2007

For a correlation to study the five tastes and efficacies in oriental medicine concepts, we used herbal medicines with bitter taste character in traditionally effective and experimental methods. In this study, we tested the in vitro effect of 20 typical kinds of herbal medicines with bitter taste on platelet aggregation induced by collagen in human whole blood using the impedance method of aggregometry. Among them, 3 kinds of hot water extracts and 2 kinds of 70% ethanol extracts showed the significant inhibiting effect on whole blood aggregation $(^{***}p<0.001)$. In particular, Coptidis Rhizoma (Coptis chinensis) extracts were selected as the most effective candidate with a strong grade of bitter taste through the sensory test of trained panels. The results from this experiment provide pharmacological evidence for the traditional use of bitter tasting herbs with traditional medicine theory, suggesting that strong bitter taste herbs could be help problems of blood circulation more than mild bitter tasting herbs.

• Applied Biological Chemistry
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• v.48 no.3
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• pp.222-227
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• 2005

To evaluate the antimutagenic activity of the specialty rices, a giant embryonic rice and a pigmented rice, we measured the inhibitory effect on the chemically induced mutagenesis in E. coli and V79 cultured cell system, as well as on DNA strand scission induced by oxidative damages in vitro. When the inhibitory activity to mitomycin C-induced mutagenesis using SOS chromotest in E. coli cell was measured, the activities decreased in the following order: germinated pigmented rice (40.4%) > germinated giant embryonic rice (37.1%) > pigmented rice (35.5%) > germinated brown rice (15.7%) > giant embryonic rice (14.0%) > brown rice (0.8%). The activities for inhibiting mitomycin C-induced DNA strand scission decreased in the order of pigmented rice > giant embryonic rice > germinated pigmented rice > germinated brown rice > brown rice > germinated giant embryonic rice. We also determined antimutagenic activities of the specialty rices using the suppressing effect on 6-TG resistant colony formation by 4-NQO in V79 cells as a mutagenicity index. The order of antimutagenicity was germinated giant embryonic rice (53.2%) > pigmented rice (40.0%) > brown rice (21.2%) > germinated brown rice (14.4%) > giant embryonic rice (0.23%); in contrast, germinated pigmented rice showed promoting effect on 4-NQO-induced mutagenesis.

• Korean Journal of Medicinal Crop Science
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• v.20 no.4
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• pp.238-244
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• 2012

In general, stepwise hot steaming process is known to be effective in improving its biological activities; however, not much employed in processing Codonopsis lanceolata due to its hardness. In this study, C. lanceolata was first pretreated with warm water at $50^{\circ}C$ and $60^{\circ}C$ for two hours, then steamed for 3 hours. Antioxidant activities of 70% ethanol extracts were compared with the extract from the water solvent: 41.58% vs 8.98% of DPPH radical scavenging activity in adding $1.25mg/m{\ell}$ of steamed extract and water extract, respectively. Reducing power of steamed and fresh C. lanceolata were also measured as 1.39 and 0.71. Total poly phenolic of the steamed extract was estimated as 12.11mg/g, compared to 3.98mg/g fresh C. lanceolata. Total flavonoid contents were also obtained as 11.48mg/g, compared to 7.11mg/g of fresh C. lanceolata. In comparing phenolic acids profiles in the extract, in general higher amounts of gallic acid, trans-ferulic acid, vanillic acid were obtained possibly by easy release of active components during thermal processing, which results in better antioxidant activities than that of water extract. This findings can also be supported by result that the ethanol extract showed better activities than the water extract.

• Journal of Life Science
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• v.28 no.1
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• pp.37-42
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• 2018

Non-steroidal anti-inflammatory drug-activated gene-1 (NAG-1) is a transforming growth factor beta (TGF-${\beta}$) superfamily gene associated with pro-apoptotic and anti-tumorigenic activities. In the present study, we investigated if caffeic acid phenethyl ester (CAPE) derived from propolis could induce the expression of anti-tumorigenic gene NAG-1. Our results indicate that CAPE significantly induced NAG-1 expression in a time- and concentration-dependent manner in HCT116 cells. We also found that CAPE induced NAG-1 expression in a concentration-dependent manner in another human colorectal cancer cell line, LOVO. In addition, CAPE triggered apoptosis, which was detected with Western blot analysis using poly-(ADP-ribose) polymerase antibody. NAG-1 induction by CAPE was not dependent on transcription factor p53, which was confirmed with Western blot analysis using p53 null HCT116 cells. The luciferase assay results indicated that the new cis-elements candidates were located between -474 and -1,086 of the NAG-1 gene promoter. CAPE dramatically induced activating transcription factor 3 (ATF3) expression, but not cAMP response element-binding protein (CREB), which shares the same binding sites with ATF3. The co-transfection experiment with pCG-ATF3 and pCREB showed that only ATF3 was associated with NAG-1 up-regulation by CAPE, whereas CREB had no effect. In conclusion, the results suggest that CAPE could induce the expression of anti-tumorigenic gene NAG-1 mainly through ATF3.