• Preventive Nutrition and Food Science
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• v.16 no.1
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• pp.12-17
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• 2011

This study was designed to investigate the protective effect of Sasa borealis leaf extract on 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced oxidative stress in LLC-PK1 cells (porcine kidney epithelial cells). The butanol fraction from Sasa borealis leaf extract (SBBF) was used in this study because it possessed strong antioxidant activity and high yield among fractions. Exposure of LLC-PK1 cells to 1 mM AAPH for 24 hr resulted in a significant decrease in cell viability, but SBBF treatment protected LLC-PK1 cells from AAPH-induced cell damage in a dose dependant manner. To determine the protective action of SBBF against AAPH-induced damage of LLC-PK1 cells, we measured the effects of SBBF on lipid peroxidation and antioxidant enzymes activities of AAPH treated cells as well as scavenging activities on superoxide anion radical and hydroxyl radical. SBBF had a protective effect against the AAPH-induced LLC-PK1 cellular damage and decreased lipid peroxidation and increased activities of antioxidant enzymes such as superoxide dismutase and glutathione peroxidase. Furthermore, SBBF showed strong scavenging activity against superoxide anion radical. The $IC_{50}$ value of SBBF was $28.45{\pm}1.28\;{\mu}g/mL$ for superoxide anion radical scavenging activity. The SBBF also had high hydroxyl radical scavenging activity ($IC_{50}=31.09{\pm}3.08\;{\mu}g/mL$). These results indicate that SBBF protects AAPH-induced LLC-PK1 cells damage by inhibiting lipid peroxidation, increasing antioxidant enzyme activities and scavenging free radicals.

• Korean Journal of Pharmacognosy
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• v.45 no.2
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• pp.147-153
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• 2014

This study was focused on the evaluation of radical scavenging effect and the protective activity against oxidative stress of the extract and fractions from Petasites japonicus. P. japonicus was extracted with methanol and then fractionated into 4 fractions [n-butanol, ethyl acetate (EtOAc), methylene chloride, and n-hexane]. The extract and fractions showed strong 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity. Among all the fractions, particularly, the EtOAc fraction showed the strongest effect with the $IC_{50}$ value of $0.02{\mu}g/ml$. In addition, the fractions also showed strong hydroxyl radical scavenging activity and nitric oxide scavenging activity as well. Furthermore, cell viability generated by the P. japonicus extract and 4 fractions were examined under C6 glial cellular model. The C6 glial cells showed high generation of reactive oxygen species (ROS) and decrease in cell viability by the treatment generator of hydrogen peroxide. However, the production of ROS formation was decreased by the treatment of the fractions of P. japonicus and also founded that the EtOAc fraction led to significant increase in the cell viability at concentration $100{\mu}g/ml$. Results from this work indicated that P. japonicus showed protective effects against oxidative stress and its EtOAc fraction may be served as a useful natural antioxidant.

• Korean Journal of Pharmacognosy
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• v.43 no.4
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• pp.297-301
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• 2012

In the course of screening for antioxidant compounds by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH), a total extract of the twigs of Taxillus delavayi (Loranthaceae) was found to show potent radical scavenging activity. Subsequent activity-guided fractionation of the methanolic extract led to the isolation of two phenolic compounds, catechin (1) and galloyl catechin (2), as active principles. Their structures were elucidated by spectroscopic studies. These two compounds showed the significant antioxidative effects on DPPH, and riboflavin- and xanthin-originated superoxide quenching activities. And these two compounds also showed strong nitric oxide radical scavenging effects. In riboflavin- and xanthin-originated superoxide quenching activities and nitric oxide radical scavenging effect, compound 2 showed better antioxidant activities than vitamin C.

• Korean journal of food and cookery science
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• v.16 no.4
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• pp.372-377
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• 2000

Six kinds of herbs(applemint, geranium, lemonbalm, rosemary, sage and thyme) were extracted with water and 95% methanol, and the electron donating ability, antibacterial activity and nitrite scavenging effect were examined. The electron donating ability of herbs ranged from 60.7 to 92.2% and the highest value was observed in geranium, followed by sage and lemonbalm. Antibacterial activity of methanol extracts was much stronger than that of water extracts and gram positive bacteria were more sensitive than gram negative bacteria. Rosemary and geranium exhibited excellent antimicrobial activities against a wide range of bacteria. Nitrite scavenging activity, which was measured at various pH conditions(1.2, 3.0, 3.6, 4.2), was the highest in all herbs at pH 1.2 and the lowest at pH 4.2, suggesting that it is pH dependent. Methanol fraction also provided higher nitrite scavenging effect than the water fraction.

• Archives of Pharmacal Research
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• v.28 no.7
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• pp.804-809
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• 2005

The EtOAc-soluble fraction from a methanolic extract of Hovenia dulcis Thunb. exhibited neuroprotective activity against glutamate-induced neurotoxicity in mouse hippocampal HT22 cells. The neuroprotective activity-guided isolation resulted in 8 phenolic compounds (1-8), such as vanillic acid (1), ferulic acid (2), 3,5-dihydroxystilbene (3), (+)-aromadendrin (4), methyl vanillate (5), (-)-catechin (6), 2,3,4-trihydrobenzoic acid (7), and (+)-afzelechin (8). Among these, compounds 6 and 8 had a neuroprotective effect on the glutamate-induced neurotoxicity in HT22 cells. Furthermore, compound 6 had a DPPH free radical scavenging effect with an $IC_{50}$ value of $57.7{\mu}M$, and a superoxide anion radical scavenging effect with an $IC_{50}$ value of $8.0{\mu}M$. Both compounds 6 and 8 had ABTS cation radical scavenging effects with $IC_{50}$ values of $7.8{\mu}M\;and\;23.7${\mu}M$, respectively. These results suggest that compounds 6 and 8 could be neuroprotectants owing to their free radical scavenging activities.

• Journal of Applied Biological Chemistry
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• v.62 no.2
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• pp.167-172
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• 2019

In vitro antioxidant effect of 50% ethanol extract from Napier grass (Penninsetum purpureum) was investigated. The yield and polyphenol content of the Napier grass extract were $6.3{\pm}0.35%$ and $79.6{\pm}3.65{\mu}g$ gallic acid equivalents/mg-extract, respectively. Antioxidant ability of the Napier grass extract such as fee radical and cation radical scavenging activities, reducing power, nitrite scavenging activity, and lipid peroxidation inhibitory activity proportionally increased as concentration of the extract increased. $EC_{50}$ values of the Napier grass extract for free radical scavenging, cation radical scavenging, reducing power, and nitrite scavenging were 1,930.0, 350.0, 840.0, and $1,470.0{\mu}g/mL$, respectively. In the presence of $85.0{\mu}g/mL$ of the Napier grass extract, lipid peroxidation was potently inhibited by 74.6%.

• Food Science and Preservation
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• v.22 no.5
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• pp.708-713
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• 2015

To provide the basic data to dry vegetate the sweetpotato leaves, the total contents of tannin, flavonoid and polyphenol in the methanol extract from the hot-air dried sweetpotato leaves were analyzed and DPPH radical scavenging activity, ABTS radical scavenging ability, nitrite scavenging ability, and others were comparatively analyzed. The total tannin content was decreased from Shinmi of 10.87 mg/g at $40^{\circ}C$ to 7.28 mg/g at $70^{\circ}C$ and the total flavonoid was decreased from Hayanmi of 55.37 mg/g at $40^{\circ}C$ to 39.63 mg/g at $70^{\circ}C$. That is, the low temperature drying contained more of these substances than in the high temperature drying. The DPPH radical scavenging activity was the highest in Shinmi and Hayanmi of 84.33% and 85.25% at $40^{\circ}C$, and the ABTS radical scavenging ability was a high value of over 80% in the treatment plot at $40^{\circ}C$. The nitrite scavenging ability was highest in Shinmi and Hayanmi of 76.15% and 73.74% at $40^{\circ}C$ but low at $70^{\circ}C$. That is, the antioxidant effect of the hot-air dried sweetpotato leaves was high in the sample of $40^{\circ}C$ and low in the sample of $70^{\circ}C$. Affected by the drying temperature, the high antioxidant effect is resulting from the little decrease of active ingredient when drying at low temperatures.

• Korean Journal of Pharmacognosy
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• v.44 no.2
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• pp.193-199
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• 2013

We investigated the antioxidative and antimicrobial activities of the methanol extracts from Korean folk plants (MKs) in Chungcheong Province. Among 30 MKs, 16 plants at $100{\mu}g/ml$ showed over 90% scavenging activity of 1,1-diphenyl-2-picrylhydrazy (DPPH) and 30 plants exerted the hydroxyl radical scavenging effect over 55%. Fourteen plants at the concentration $50{\mu}g/30{\mu}l$ showed strong microbial inhibition activity against Escherichia coli and Staphylococcus aureus, with clear zone greater than 11 mm in disc assays. Furthermore, the protective effect against anti-inflammatory system using RAW 264.7 macrophage cell was also studied. The treatment of LPS & INF-${\gamma}$ to RAW 264.7 cell induced nitric oxide (NO), however inhibit the formation of NO less than 50% of 5 plants. The present result indicates that the 30 species of MKs exerts protective effect of oxidative stress, antimicrobial activities and anti-inflammatory. In particular, Rhus javanica and Cornus controversa showed stronger effect on not only radical scavenging activity and inhibits growth of S. aureus but also highest protective effects from inflammation.

• The Korean Journal of Food And Nutrition
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• v.15 no.2
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• pp.97-103
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• 2002

Five citrus juices were separated into a ascorbate and phenolic portion using rep-pak C$\_$18/ cartridge, respectively, in order to elucidate the nitrite scavenging effect and N-nitrosodimethylamine(NDMA) formation in model system. The nitrite scavenging effect of ascorbate portion from citrus juices, in the different pH, when added with 5ml were 79.9 ∼98.6% under the condition of pH 2.5. 48.5∼86.3% at pH 4.2 and lower than 35.2% at pH 6.0. The nitrite scavenging effect was excellent phenolic portion rather than ascorbate portion. Particularly, the effect was more 2 times than ascorbate portion under the reaction condition of pH 6.0. When added the phenolic portion in the reaction mixture, NDMA formation was inhibited 92.8% or more in kum quat, mandarin orange and sweet orange juices. But the ascorbate portion was a negative response of the inhibition of NDMA formation. The inhibition on NDMA formation in citrus juice may be due to phenolic compounds were reacted.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.34 no.4
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• pp.24-36
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• 2021

Objectives : This study was conducted to confirm the anti-oxidative effect of Chungpyesagan-tang(CPSGT) extract. Methods : In this study, MTT assay was performed to confirm cell viability, and DPPH and ABTS were performed to confirm radical scavenging ability. The ROS scavenging ability and the protective effect against DNA damage were confirmed by 2,7-dichlorofluorescin diacetate(DCF-DA) and 4',6-diamidino-2-phenylindole(DAPI) staining and comet assay. mRNA expression of Heme oxygenase-1(HO-1) was measured by real-time PCR, and expression of HO-1 and Kelch-like ECH-associated protein 1(Keap1) proteins was measured by western blot. Results : CPSGT was not cytotoxic at 50-400㎍/㎖. The radical scavenging activity was increased, and the ROS scavenging activity and the protective effect against DNA damage were increased compared to the LPS-treated group. The mRNA expression and protein expression of HO-1 were increased in a concentration-dependent manner. The protein expression level of Keap1 was decreased in a concentration-dependent manner. Conclusion : This suggests that CPSGT has an antioxidant effect and can be used as a potential material for skin diseases.