• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2005.06a
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• pp.154-164
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• 2005

Saccharomyces cerevisiae KNU5377 is a thermotolerant strain, which can ferment ethanol from wasted papers and starch at 40$^{\circ}C$ with the almost same rate as at 30$^{\circ}C$. This strain showed alcohol fermentation ability to convert wasted papers 200 g (w/v) to ethanol 8.4% (v/v) at 40$^{\circ}C$, meaning that 8.4% ethanol is acceptable enough to ferment in the industrial economy. As well, all kinds of starch that are using in the industry were converted into ethanol at 40$^{\circ}C$ with the almost same rate as at 30$^{\circ}C$. Hyperthermic cell killing kinetics and differential scanning calorimetry (DSC) revealed that exponentially growing cells of this yeast strain KNU5377 were more thermotolerant than those of S. cerevisiae ATCC24858 used as a control. This intrinsic thermotolernace did not result from the stability of entire cellular components but possibly from that of a particular target. Heat shock induced similar results in whole cell DSC profiles of both strains and the accumulation of trehalose in the cells of both strains, but the trehalose contents in the strain KNU5377 were 2.6 fold higher than that in the control strain. On the contrary to the trehalose level, the neutral trehalase activity in the KNU5377 cells was not changed after the heat shock. This result made a conclusion that though the trehalose may stabilize cellular components, the surplus of trehalose in KNU5377 strain was not essential for stabilization of whole cellular components. A constitutively thermotolerant yeast, S. cerevisiae KNU5377, was compared with a relatively thermosensitive control, S. cerevisiae ATCC24858, by assaying the fluidity and proton ATPase on the plasma membrane. Anisotropic values (r) of both strains were slightly increased by elevating the incubation temperatures from 25$^{\circ}C$ to 37$^{\circ}C$ when they were aerobically cultured for 12 hours in the YPD media, implying the membrane fluidity was decreased. While the temperature was elevated up to 40$^{\circ}C$, the fluidity was not changed in the KNU5377 cell, but rather increased in the control. This result implies that the plasma membrane of the KNU5377 cell can be characterized into the more stabilized state than control. Besides, heat shock decreased the fluidity in the control strain, but not in the KNU5377 strain. This means also there's a stabilization of the plasma membrane in the KNU5377 cell. Furthermore, the proton ATPase assay indicated the KNU5377 cell kept a relatively more stabilized glucose metabolism at high temperature than the control cell. Therefore, the results were concluded that the stabilization of plasma membrane and growth at high temperature for the KNU5377 cell. Genome wide transcription analysis showed that the heat shock responses were very complex and combinatory in the KNU5377 cell. Induced by the heat shock, a number of genes were related with the ubiquitin mediated proteolysis, metallothionein (prevent ROS production from copper), hsp27 (88-fold induced remarkably, preventing the protein aggregation and denaturation), oxidative stress response (to remove the hydrogen peroxide), and etc.

• Korean Journal of Food Science and Technology
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• v.50 no.2
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• pp.216-224
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• 2018

To evaluate physiological effect of Aralia elata, in vitro antioxidant activity and hepatic protective effects were investigated. Ethyl acetate fraction from Aralia elata (EFAE) had higher total phenolic content than other fractions (n-hexane, chloroform, and distilled water layers). EFAE also showed significantly greater radical scavenging activity against 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH), than other fractions. Moreover, EFAE showed dose-dependent inhibitory effect of malondialdehyde (MDA). Hepatoprotective effects of EFAE against ethanol- and $H_2O_2$-induced oxidative stress and cytotoxicity in H4IIE and HepG2 hepatic cells were examined using 2',7'-dichlorofluorescein diacetate (DCF-DA) and 3-[4,5-dimethythiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay. The results showed that EFAE reduced cellular oxidative stress, and increased hepatic cell viability. In addition, EFAE inhibited ethanol-induced lipid accumulation in HepG2 cells. Finally, physiological substances of EFAE were analyzed using high performance liquid chromatography (HPLC), and the major bioactive compounds identified were 3,5-dicaffeoylquinic acid and chlorogenic acid.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.6
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• pp.939-948
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• 2008

The effects of goat's beard (Aruncus dioicus var ramtschaticus Hara) ethanol extracts (AD) on the streptozotocin-induced diabetic symptoms and oxidative stress in rats were assessed. Experimental plots were divided into normal controls (NC), diabetes controls (DM), diet with 0.3% AD after diabetes induction (SA), and diet with 0.6% AD after diabetes induction (SB), then fed for 5 weeks. In the SA and SB groups as compared with the DM group, diabetic symptoms including weight loss, increase in feed and water intake, and enlargement of the liver and kidney were improved. The levels of blood glucose and serum fructosamine were reduced by $17.9{\sim}27.2%$ and $25.6{\sim}32.6%$, respectively. The activities of alanine aminotransferase, aspartate aminotransferase and the levels of triglycerides, total cholesterol, and LDL-cholesterol in the serum were reduced by $25.6{\sim}30.3$, $42.37{\sim}55.51$, $26.85{\sim}30.44$ and $37.29{\sim}39.11%$, respectively, whereas the level of HDL-cholesterol was increased by $37.29{\sim}39.11%$. Hepatic total (T) and O type (O) activities of xanthine oxidoreductase, O/T ratio(%) and level of lipid peroxide were significantly decreased, while the level of glutathione was increased, and also the activities of superoxide dismutase and glutathione S-transferase were increased by $56.84{\sim}94.90%$ and $57.14{\sim}68.92%$, respectively. In the above results, it was noted that AD has an antidiabetic effect which alleviated hyperglycemia and the AD reduced and/or prevented the tissue damage caused by diabetes yia the inhibition of reactive oxygen species (ROS) generating systems concurrent with an increase in ROS scavenging.

• Journal of Nutrition and Health
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• v.50 no.5
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• pp.415-425
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• 2017

Purpose: Many studies have suggested that neuronal cells protect against oxidative stress-induced apoptotic cell death by polyphenolic compounds. We investigated the neuroprotective effects and the mechanism of action of Momordica charantia ethanol extract (MCE) against $H_2O_2-induced$ cell death of human neuroblastoma SK-N-MC cells. Methods: The antioxidant activity of MCE was measured by the quantity of total phenolic acid compounds (TPC), quantity of total flavonoid compounds (TFC), and 2,2-Diphenyl-1-pycrylhydrazyl (DPPH) radical scavenging activity. Cytotoxicity and cell viability were determined by CCK-8 assay. The formation of reactive oxygen species (ROS) was measured using 2,7-dichlorofluorescein diacetate (DCF-DA) assay. Antioxidant enzyme (SOD-1,2 and GPx-1) expression was determined by real-time PCR. Mitogen-activated protein kinases (MAPK) pathway and apoptosis signal expression was measured by Western blotting. Results: The TPC and TFC quantities of MCE were 28.51 mg gallic acid equivalents/extract g and 3.95 mg catechin equivalents/extract g, respectively. The $IC_{50}$ value for DPPH radical scavenging activity was $506.95{\mu}g/ml$ for MCE. Pre-treatment with MCE showed protective effects against $H_2O_2-induced$ cell death and inhibited ROS generation by oxidative stress. SOD-1,2 and GPx-1 mRNA expression was recovered by pre-treatment with MCE compared with the presence of $H_2O_2$. Pre-treatment with MCE inhibited phosphorylation of p38 and the JNK pathway and down-regulated cleaved caspase-3 and cleaved PARP by $H_2O_2$. Conclusion: The neuroprotective effects of MCE in terms of recovery of antioxidant enzyme gene expression, down-regulation of MAPK pathways, and inhibition apoptosis is associated with reduced oxidative stress in SK-N-MC cells.

• Journal of Nutrition and Health
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• v.52 no.6
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• pp.529-539
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• 2019

Purpose: Sprouts of evening primrose (Oenothera laciniata, OL) were reported to have high contents of flavonoids and potent antioxidant activity. This study examined the antioxidant and antiobesity activities of OL sprouts to determine if they could be a natural health-beneficial resource preventing obesity and oxidative stress. Methods: OL sprouts were extracted with 50% ethanol, evaporated, and lyophilized (OLE). The in vitro antioxidant activity of OLE was examined using four different tests. The antiobesity activity and in vivo antioxidant activity from OLE consumption were examined using high fat diet-induced obese (DIO) C57BL/6 mice. Results: The IC₅₀ for the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging and superoxide dismutase (SOD)-like activities of OLE were 26.2 ㎍/mL and 327.6 ㎍/mL, respectively. OLE exhibited the ferric reducing antioxidant power (FRAP) activity of 56.7 ㎍ ascorbic acid eq./mL at 100 ㎍/mL, and an increased glutathione level by 65.1% at 200 ㎍/mL compared to the control in the hUC-MSC stem cells. In an animal study, oral treatment with 50 mg or 100 mg of OLE/kg body weight for 14 weeks reduced the body weight gain, visceral fat content, fat cell size, blood leptin, and triglyceride levels, as well as the atherogenic index compared to the high fat diet control group (HFC) (p < 0.05). The blood malondialdehyde (MDA) level and the catalase and SOD-1 activities in adipose tissue were reduced significantly by the OLE treatment compared to HFC as well (p < 0.05). In epididymal adipose tissue, the OLE treatment reduced the mRNA expression of leptin, PPAR-γ and FAS significantly (p < 0.05) compared to HFC while it increased adiponectin expression (p < 0.05). Conclusion: OLE consumption has potent antioxidant and antiobesity activities via the suppression of oxidative stress and lipogenesis in DIO mice. Therefore, OLE could be a good candidate as a natural resource to develop functional food products that prevent obesity and oxidative stress.

• Mycobiology
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• v.40 no.2
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• pp.117-123
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• 2012

Nuruk contributes to the unique characteristics of Korean alcoholic beverages. In this study, the effects of nuruk extracts (NE) on anti-oxidant characters, melanogenesis, and anti-photoaging activity were investigated. NEs were obtained from the 70% ethanol extracts of six types of nuruk, which have been used in brewing of fermented alcohol beverages in Korea. First, various antioxidant characteristics were identified in terms of 2,2'-azino-bis(3-ethylbenzthiozoline-6-sulphonic acid) (ABTS) radical scavenging activity, superoxide dismutase (SOD) expression, and inhibition of xanthine oxidase activity. NE#4 exhibited potent ABTS radical scavenging activity ($IC_{50}$ = 19.51 ${\mu}g$/mL). Compared with NE#4, relatively lower levels of activity were observed for NE#3 and NE#6, with $IC_{50}$ values of 90.99 and 76.88 ${\mu}g$/mL, respectively. According to results of western blot analysis for determination of SOD expression in $H_2O_2$-treated HepG2 cells, NE#5 and NE#6 induced a dramatic increase in the expression ratio of SOD, compared to the group treated with $H_2O_2$ only. Activity of xanthine oxidase, which converts xanthine into uric acid, generating superoxide ions, was inhibited by NE#4 and NE#6 in a dose-dependent manner. NE#4 induced significant inhibition of mushroom tyrosinase activity. A reduction in cellular melanin contents of 80% was observed in B16F1 melanocytes treated with NE#5 and NE#6; these effects were similar to those of arbutin at 100 ${\mu}M$. In addition, gelatin zymography and reverse transcription-PCR analysis were performed for assessment of anti-photoaging activity of Nuruk. Treatment with NE#6 resulted in dramatically inhibited activities of matrix metalloproteinase (MMP)-2/-9, suppressed expression of MMP-1, and increased expression of type-1 procollagen. Results of gelatin zymography for NE#4 and NE#5 were similar, to a slightly lesser degree. These results suggest the potential of NE#4 and NE#6 as natural ingredients for use in functional foods and cosmetics.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.6
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• pp.805-812
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• 2010

DNA damage including base modifications, loss of base and breaks in DNA strands can occur by exposure to irradiation, smoking and several components of food. Unrepaired DNA damage is known to lead to cellular dysfunction, cell death, cancer, and other diseases such as arteriosclerosis and diabetes. The protective effect of garlic on oxidative stress induced DNA damage has been reported recently. In this study, we investigated the protective effect of garlic extracts prepared by different processing methods (raw garlic extracts, RGE; grilled garlic extracts, GGE; pickled garlic extracts, PGE) on leukocytic DNA damage using comet assay. Human leukocytes were incubated with ethanol and methanol extract of garlic at various concentrations (1, 5, 10, 50 ${\mu}g$/mL), followed by oxidative stimuli (200 ${\mu}M$ $H_2O_2$ or 200 ${\mu}M$ 4-hydroxynonenal (HNE)). The methanol and ethanol extracts of RGE, GGE, and PGE showed inhibitory activities of DNA damage induced by $H_2O_2$ or HNE. Especially methanol extract of RGE ($ED_{50}$; 13.3 ${\mu}g$/mL) had a higher antigenotoxic effect on $H_2O_2$ induced DNA damage than those of GGE (23.5 ${\mu}g$/mL) or PGE (24.5 ${\mu}g$/mL). HNE induced DNA damage tended to be effectively inhibited by the lower concentration of all garlic extracts. Therefore, garlic might have protective effects against oxidative DNA damage regardless of processing methods (raw, grilled, pickled) which are the general consumed forms of garlic in Korea.

• Journal of the Korean Applied Science and Technology
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• v.36 no.4
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• pp.1303-1311
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• 2019

This study was to investigate the antioxidant, anti-inflammatory and neuronal cell protective effects of Poria cocos Wolf and Corni fructus extracted by water and 70% ethanol. Total polyphenol content in water extract of Poria cocos Wolf was significantly higher than those of other extracts. DPPH and ABTS free radical scavenging activity in water extract of Corni fructus was higher than those of other extracts. DPPH and ABTS free radical scavenging activity were increased in a dose-dependent manners. In order to effectively extract total polyphenol contents and anti-oxidant components in Poria cocos Wolf and Corni fructus, hot water extraction method is more efficient than ethanol extraction method. Poria cocos extracts were found to be a superior NO production inhibitory effect compared to Corni fructus extracts. In a neuronal cell viability assay using MPP⁺, the water extract of Poria cocos Wolf protected against MPP⁺-induced neurotoxicity than those of Corni fructus extract. It is considered to be a potential functional material with antioxidant, anti-inflammatory and neuronal protective effect against to oxidative stress according to the extract methods of extracting Poria cocos Wolf and Corni fructus.

• Food Science and Preservation
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• v.16 no.2
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• pp.238-245
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• 2009

The antioxidant effects of chungkukjang, a popular fermented soybean paste in Korea, prepared with solar salt were investigated in vitro. DJI chungkukjang(DJIC) was prepared using 3%(w/w) solar salt or 3%(w/w) refined salt, and fermented by Bacillus subtilis DJI. All of DJIC with no salt, DJIC with 3%(w/w) solar salt, DJIC containing 3%(w/w) refined salt, and commercial chungkukjang were extracted with ethanol, hexane, and water. Antioxidative activities were measured by 1,1-diphenyl-2-picryl hydrazyl(DPPH) free-radical generation, nitrite scavenging activity, peroxide value in the presence of linoleic acid, and the Rancimat test, in comparison with the commercial antioxidant butylated hydroxytoluene(BHT). Ethanol chungkukjang extracts showed the highest antioxdative capacities, whereas DPPH free-radical generation and scavenging activities, and linoleic acid peroxide values of DJIC extracts prepared using solar salt, and salt-free DJIC, showed the greatest values. In addition, extracts of DJIC prepared using solar salt had the highest antioxidant indices. Antioxidative activities were higher in DJIC extracts than in those of commercial chungkukjang. However, the antioxidative capacities of DJIC prepared using solar salt and DJIC with no added salt were less than those of BHT. In conclusion, these results suggest that extracts of chungkukjang prepared using solar salt are useful nutritional antioxidants and that dietary supplementation with such materials would decrease oxidative stress.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.8
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• pp.1102-1106
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• 2010

This study was carried out to investigate the effect of ethanol extract from citrus peels (CP-Et) against the alloxan-induced oxidative damage on HIT-T15, Hamster pancreatic $\beta$-cell. Total polyphenol and flavonoid contents in CP-Et were $57.00{\pm}2.91\;mg/g$ and $8.11{\pm}2.83\;mg/g$, respectively. Cell toxicity on HIT-T15 by CP-Et (0.125~0.75 mg/mL) was not observed. CP-Et (0.125 mg/mL) increased cell proliferation rate of HIT-T15, which was treated alloxan ($IC_{50}=11.58\;mM$) (cell viability=$80.52{\pm}3.29%$ of normal cell, p<0.05). In comparison with insulin secretion of oxidative damaged HIT-T15, 1.5 fold ($116.93{\pm}2.11\;{\mu}g/mg$ protein) was increased by treatment CP-Et treatment (0.125 mg/mL) in HIT-T15 (p<0.05). These results showed that CP-Et contribute to repairing cells and improvement of insulin expression on oxidative stress pancreatic $\beta$-cell, and also suggested application of CP-Et as a functional food material for type 2 diabetes.