• Biomolecules & Therapeutics
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• v.28 no.1
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• pp.25-33
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• 2020

Several recent studies have reported that reactive oxygen species (ROS), superoxide anion and hydrogen peroxide (H₂O₂), play important roles in various cellular signaling networks. NADPH oxidase (Nox) isozymes have been shown to mediate receptor-mediated ROS generation for physiological signaling processes involved in cell growth, differentiation, apoptosis, and fibrosis. Detectable intracellular levels of ROS can be induced by the electron leakage from mitochondrial respiratory chain as well as by activation of cytochrome p450, glucose oxidase and xanthine oxidase, leading to oxidative stress. The up-regulation and the hyper-activation of NADPH oxidases (Nox) also likely contribute to oxidative stress in pathophysiologic stages. Elevation of the renal ROS level through hyperglycemia-mediated Nox activation results in the oxidative stress which induces a damage to kidney tissues, causing to diabetic nephropathy (DN). Nox inhibitors are currently being developed as the therapeutics of DN. In this review, we summarize Nox-mediated ROS generation and development of Nox inhibitors for therapeutics of DN treatment.

• Korean journal of food and cookery science
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• v.30 no.6
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• pp.757-766
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• 2014

The purpose of this study was to investigate the antioxidant effects of non-fermented (CAC) and Monascus pilosus-fermented Columbia arabica coffee (FCAC), as well as Luwak coffee (LC) beans. The results indicated that total polyphenols content (mg/g of dry basis) was highest in CAC (70.69), followed by LC (62.07), and FCAC (41.38). However, the ratio of total flavonoids/polyphenols in FCAC was the highest. In terms of electron donating ability (%, coffee mg/mL), CAC was significantly higher than LC and FCAC. Regardless of fermentation, ferric reducing antioxidant powers were similar in CAC and FCAC and lowest in LC. LC also had the highest inhibitory activity against xanthine oxidase (XO). However FAAC had the highest inhibitory activity against aldehyde oxidase (AO), with nearly three times the levels found in CAC and LC. According to the above results, FCAC had a higher ratio of flavonoids/polyphenols and iron chelating activity than CAC. FCAC also had the highest AO inhibitory activity among the three experimental coffee beans. The results suggest that further studies are required to evaluate the bioactive components of various coffee beans so as to determine the potential benefits that coffee may have on preventing oxidative stress-related conditions.

• Preventive Nutrition and Food Science
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• v.5 no.2
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• pp.105-108
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• 2000

To evaluate an effect of oxygen free radical on the toluence metabolism, the rats were fed on a tungstate sup-plemented diet(0.75g of tungstate included in 1kg of standard diet) or a standard diet. To the present xanthine oxidase deficient animal model, toluene(0.15ml/100g of body weight) was injected and then the animals were sacrificed after 24 hrs to determine the toluene metabolizing enzyme activities and toluene metabolite, hippuric acid concentration. The increasing rate of urinary hippuric acid concentration was significantly(p<0.01) higher in tungstate fed animals than in standard diet fed ones. Hepatic cytochrome P_450 contents were significantly higher(p<0.01) in tungstate fed animals than in standard diet fed ones. And tungstate fed animals showed a ten-dency of higher activities of benzylalcohol dehydrogenase while a significantly higher activites of benzaldehyde dehydrogenase (p<0.01) than standard diet fed animals. In conclusion, the more possibly reduced oxygen free radical in toluene-treated rats fed with a tungstate supplemented diet than in those fed with a standard diet would be responsible for the enhancement of toluene metabolism.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.2
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• pp.268-273
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• 2000

To investigate an effect of the ethanol extract of Lycium chinense(EELC) on the activities of enzymes scavenging oxygen free radicals or detoxicating alcohol. The ground Lycium chinense was extracted with 30% edible ethanol and then diluted with 6% ethanol to contain 2% EELC(w/v). Three different groups of male Sprague-Dawley rats had taken a drink EELC, ethanol(ETH) or water(control), respectively for 2 months. At the end of experimental period, the animals were sacrificed and obtained the following findings. The EELC-treated animals showed the highest activity of hepatic glucose-6-phosphatase among three groups. The activities of xanthine oxidase and cytochrome p-450 from EELC treatment group were lower than those from ETH-treated group. However, the activity of superoxide dismutase was higher in the EELC-treated group than the ETH-treated(p<0.005). Furthermore, hepatic alcohol or aldehyde dehydrogenase activity, and glutathione content and glutathione peroxidase were significantly higher in EELC-treated animals than in ETH-treated those. The activity of glutathione S-transferase in liver was appeared the orderly higher value in EELC, ETH and control-treated group. As the result, EELC may affect the reduction of oxygen free radical production and help the detoxication of ethanol.

• Preventive Nutrition and Food Science
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• v.9 no.3
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• pp.245-252
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• 2004

This study investigated the effects of an ethanol extract of Allium monanthum MAX. (AME) on ethanol-induced hepatotoxicity in rat liver. Sprague-Dawley rats weighing 100～150 g, were divided into 5 groups; normal group (NOR), AME 200 mg/kg treated group (S1), ethanol (35%, 10 mL/kg) treated group (S2), AME 200 mg/kg and ethanol (35%, 10 mL/kg) treated group (S3) and AME 400 mg/kg and alcohol (35%, 10 mL/kg) treated group (S4). AME was fractionated by the following solvents: n-hexane, chloroform, EtOAC and n-BuOH. Antioxidant index of the n-BuOH fraction was 600 ppm, highest among fractions. The growth rate and feed efficiency ratio were decreased by ethanol, but gradually increased to the corresponding level of the normal group by administering AME. The serum ALT activities that were elevated by ethanol were significantly decreased by AME administration. It was also observed that the hepatic activities of SOD, catalase, xanthine oxidase and GSH-Px that were increased by ethanol were also markedly decreased in the AME treated group with compared to ETB. These results suggest that ethanol extracts of Allium monanthum MAX. may have a protective effect on ethanol-induced hepatotoxicity in rat liver.

• YAKHAK HOEJI
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• v.28 no.1
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• pp.49-51
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• 1984

After pretreatment with ginseng followed by induction of acute intoxication of alcohol, the activities of alcohol dehydrogenase (ADH), microsomal ethanol-oxidizing system (MEOS) and aldehyde dehydrogenase(Ald DH) increased respectively compared to the groups treated with alcohol alone. In case that ginseng was given to rats fed with 5% alcohol instead of water for 60 days, the activities of ADH and MEOS increased compared to the groups treated. On the contrary, the activity of Ald DH in mitochondrial fraction decreased to an extent of about 35% in chronic alcoholism, but after pretreatment of ginseng the activity was restored to the control level. On the other hand, the catalase activity was not significantly affected by either treatment. Ginseng butanol fraction significantly increased the serum isocitrate dehydrogenase activity which is inhibited by alcohol-treated in rat. Alcohol-induced lactate dehydrogenase activity was decreased to control level in liver by ginseng treatment. And the serum level of lactic acid also decreased by ginseng treatment in alcohol-intoxicated rat. Ginseng butanol fraction markedly decreased the xanthine oxidase activity in the ethanol-treated rat liver. It was also observed that ginseng reduced the blood concentration of uric acid on experimentally reduced hyperuricemia by alcohol treatment. Uricase activity was not affected by either treatment. Ginseng butanol fraction decreased the hepatic aniline hydroxylase activity which was induced by alcohol-treated rat. These results suggest that the treatment with ginseng can be promoted the recovery from alcohol intoxication and some therapeutic effect on alcoholinduced metabolic disease.

• Korean Journal of Food Science and Technology
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• v.54 no.4
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• pp.386-390
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• 2022

This study aimed to investigate the biological and antibacterial activities of phenolics from Sambucus sieboldiana var. pendula leaf extract. The phenolic contents of the S. sieboldiana var. pendula extracted with water and ethanol was 11.60 and 12.39 mg/g, respectively. The inhibitory effects of the water and ethanol extracts on the angiotensin converting enzyme (ACE) were 71.94-92.08 and 48.42-78.33%, respectively, and on xanthine oxidase (XOase) were 42.11-100 and 35.61-100%, respectively, at a phenolic concentration of 50-200 ㎍/mL. All these effects were found to be concentration-dependent. Additionally, the leaf extracts exhibited excellent antibacterial activities against Streptococcus mutans, Staphylococcus aureus, and Propionibacterium acnes. Hence, S. sieboldiana var. pendula was confirmed to have excellent antihypertensive, antigout, and antimicrobial properties.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.57 no.3
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• pp.209-215
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• 2024

Ishige foliacea belongs to class Phaeophyceae and family Ishigeaceae. This study investigated the physiological activities of the Korean marine algae I. foliacea. Its solvent extracts were prepared with 70% ethanol, 80% methanol, and distilled water. The ethanol and methanol extracts had higher α-glucosidase (half-maximal inhibitory concentration, IC₅₀: 0.67-0.73 mg/mL), xanthine oxidase (IC₅₀: 0.25-0.28 mg/mL), and angiotensin-converting enzyme (IC₅₀: 25.29-38.28 ㎍/mL) inhibitory activities than those of the water extract. The ethanol and methanol extracts possessed high acetylcholinesterase inhibitory activity (IC₅₀: 0.78c0.97 mg/mL). Conversely, the water extract exhibited the highest β-secretase inhibitory activity (IC₅₀: 0.48 mg/mL). These results indicate that I. foliacea may be useful as a functional substance in food and pharmaceuticals with anti-diabetic, anti-gout, anti-hypertension, and anti-dementia properties.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.3
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• pp.369-377
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• 2013

In order to increase the utilization of sweet potato leaves and stalks as much as roots, it is necessary to study their beneficial potential. In this study, the antioxidant, antiallergic and anti-inflammatory effects of sweet potato leaves and stalks were evaluated by measuring total polyphenol and flavonoid contents, DPPH radical scavenging effects, the reducing power and inhibition effects on xanthine oxidase (XO), 5-lipoxygenase (LOX), and cyclo-oxygenase (COX)-2 activities. Blanched sweet potato leaves (SL), raw whole purple stalks (ST) and peeled stalks (PST) were freeze-dried and extracted with 95% ethanol. Total polyphenol content was highest in SL (11.03 mg/g), followed by ST (0.87 mg/g), and PST (0.37 mg/g). Total flavonoid content was highest for SL (9.01 mg/g), followed by ST (0.50 mg/g) and PST (0.25 mg/g). The $IC_{50}$ for DPPH radical scavenging effects was highest for SL ($43.6{\mu}g/mL$), followed by ST ($308.4{\mu}g/mL$) and PST ($1,631.3{\mu}g/mL$). The reducing power was highest for SL ($59.72{\mu}g$ ascorbic acid eq./mL), followed by ST ($12.56{\mu}g$ ascorbic acid eq./mL) and PST ($2.18{\mu}g$ ascorbic acid eq./mL) with $1,000{\mu}g/mL$ of ethanol extract. The inhibition rate on XO activity was highest for SL (13.06%), followed by ST (5.05%) and PST (0.0%) at $250{\mu}g/mL$ extract treatment. The inhibition rate on COX-2 activity was highest for SL (55.34%), followed by ST (2.18%) and PST (0.0%) at $250{\mu}g/mL$ extract treatment. The inhibition rate on 5-LOX activity was highest for SL (91.16%), followed by ST (33.38%) and PST (14.93%) at $50{\mu}g/mL$ treatment. Taken together, sweet potato leaves showed high antioxidative, anti-allergic and anti-inflammatory activities, especially with very strong inhibition effects on 5-LOX activity. These beneficial effects of sweet potato leaves might be mainly caused by the high content of polyphenols and flavonoids.

• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.5
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• pp.520-529
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• 2014

The purpose of this study is to investigate the protective effects of Yukmijiwhang-tang(YM) water extracts against the UVB irradiation on the human keratinocyte HaCaT cells. We observed the effects of YM on the oxidative stress, gene expression of pro-inflammatory cytokine such as TNF-${\alpha}$ and IL-$1{\beta}$, and matrix metalloproteinase-9 in UVB-irradiated HaCaT cells. On the effects of oxidative stress and antioxidant function on the treatment with YM, The activity of xanthine oxidase(XO) was significantly decreased by treatment of YM in all the concentrations(p<0.01). The activity of superoxide dismutase(SOD) and catalase(CAT) was significantly increased by treatment of YM in a dose dependent manner(p<0.05 and p<0.01). DPPH radical was erased by treatment of YM under dose of $500{\mu}g/m{\ell}$ concentration. Treatment of HaCaT cells with YM had also significantly reduced intracellular ROS produced by UVB irradiation in a dose dependent manner(p<0.05, p<0.01, p<0.001). Gelatin zymography assay showed that YM downregulated the MMP-9 activity in UVB-irradiated HaCaT cells. RT-PCR analysis revealed that YM suppressed the expression of IL-$1{\beta}$ and MMP-9 however, it has no effects on the expression of TNF-${\alpha}$ and MMP-3. Our study suggests that Yukmijiwhang-tang exert protective actions on the UVB-irradiated HaCaT cells largely by anti-oxidative and anti-inflammatory processes.