• Biomolecules & Therapeutics
• /
• v.2 no.3
• /
• pp.298-302
• /
• 1994

Wistar albino rats were injected subcutaneously with mercuric chloride (5 mg/kg) to define the early biochemical determinants that participate in the pathogenesis of mercuric chloride-induced hepatotoxicity, especially focusing on oxygen free radicals, we studied malondialdehyde(MDA) level and the activities of catalase and superoxide dismutase in the liver of rats at 24, 48 and 72 hr after the injection of mercuric chloride. MDA levels at 24, 48 and 72 hr after the injection of mercuric chloride increased as compared with that of control group. The activities of catalase and superoxide dismutase at 24, 48 and 72hr after the injection of mercuric chloride decreased as compared with that of control group. These results suggest that the depression of the activities of catalase and superoxide dismutase resulting from excessive oxygen free radicals is an important determinant in pathogenesis of mercuric chloride-induced hepatotoxicity.

• Bulletin of the Korean Chemical Society
• /
• v.10 no.1
• /
• pp.104-106
• /
• 1989

Halopyrimidines such as 2-chloro-, 5-bromo, and 4,6-dichloro-5-nitropyrimidine undergo substitution reactions with superoxide anion radical (superoxide) to give the corresponding hydroxypyrimidines under suitable conditions. Parallel experiments employing hydroxide instead of superoxide strongly indicate that the reactivity of superoxide is comparable to that of the hydroxide in the reaction with halopyrimidines. The results seem to provide a piece of information in favor of the nucleophilic substitution rather than electron-transfer mechanism in the title reaction.

• Food Science and Biotechnology
• /
• v.16 no.6
• /
• pp.1041-1045
• /
• 2007

Heated onion juice was partitioned using the solvents hexane, chloroform, ethyl acetate, and butanol. The ethyl acetate fraction showed the strongest scavenging effect on the ABTS radical. The antioxidant activities of the ethyl acetate fraction from raw and heated onion (120, 130, and $140^{\circ}C$) were evaluated using radical scavenging assays. Radical and nitrite scavenging activities were higher in heated onion than raw onion, and the higher the temperature of heat treatment, the greater the radical and nitrite scavenging activities. Heated onion ($140^{\circ}C$, 2 hr) was more effective than raw onion, having higher DPPH radical scavenging (5.7-fold), hydroxyl radical scavenging (6.4-fold), superoxide radical scavenging (2.3-fold), hydrogen peroxide scavenging (11.8-fold), and nitrite scavenging (4.3-fold) activities. Onion increased its physiologically active materials after heating, and in this regard, heated onion can be used as biological material for the manufacture of health foods and supplements.

• Journal of Life Science
• /
• v.21 no.10
• /
• pp.1377-1384
• /
• 2011

Astaxanthin (ATX) is a red-orange carotenoid pigment that occurs naturally in a wide variety of living organisms. In this study we investigated the inhibitory effects of ATX on the induction of inducible nitric oxide synthase (iNOS), nitric oxide (NO), proinflammatory cytokines, nuclear factor-kappa B(NF-${\kappa}B$) and reactive oxygen species (ROS) in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. In addition, we tested the superoxide radical scavenging activity of ATX by scavenging assay. iNOS and NF-${\kappa}B$ expressions were determined by immunoblot analysis. Interleukin (IL)-6 and tumour necrosis factor-${\alpha}$ (TNF-${\alpha}$) were assayed by ELISA. NO production was monitored by measuring the amount of nitrite. ROS was examined by using the 2', 7'-Dichlorodihydrofluorescin diacetate (DCFH-DA) method. At a concentration of 100 ${\mu}M$, ATX inhibited the expression level of LPS-induced NF-${\kappa}B$, as well as the production of LPS-induced NO and proinflammatory cytokines (IL-6 and TNF-${\alpha}$), by suppressing iNOS expression. In particular, the maximal inhibition rate of IL-6 and TNF-${\alpha}$ production by ATX (100 ${\mu}M$) was 65.2----- and 21.2-----, respectively. In addition, ATX inhibited the LPS-induced transcriptional activity of NF-${\kappa}B$, and this was associated with suppressing the translocations of NF-${\kappa}B$ from the cytosol to the nucleus. Moreover, at various concentrations (25-100 ${\mu}M$), ATX inhibited the intracellular level of ROS. At a concentration of 5 mg/ml, the superoxide radical scavenging activity of ATX was 1.33 times higher than ${\alpha}$-tocopherol of the same concentration. These results showed that ATX inhibited the expression of iNOS and the production of NO and proinflammatory cytokines resulting from ROS production and NF-${\kappa}B$ activation in macrophages. Furthermore, ATX was found to be more effective in superoxide radical scavenging activities compared to ${\alpha}$-tocopherol. These findings are expected to strengthen the position of ATX as anti-inflammatory medicine and antioxidant.

• Food Science and Preservation
• /
• v.22 no.4
• /
• pp.577-584
• /
• 2015

The objective of this study was to investigate the antioxidant activity of imported tropical and subtropical fruits including dragon fruits, green kiwi, papaya, pineapple, pomegranate, and yellow mango. A seventy percent of ethanol extracts were prepared. Total phenolic content, DPPH (1,1-diphenyl-2-picryl hydrazyl)-, ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)), superoxide anion radical scavenging activity, FRAP (ferric reducing antioxidant power), tyrosinase inhibitory activity, and reducing power were investigated for the comparisons of antioxidant activities. The phenolic content expressed as gallic acid equivalents (GAE) was found to be highest in pomegranate (12.22 mg GAE/g), followed by pineapple (3.77 mg GAE/g). Pomegranate and pineapple exhibited higher antioxidant activity than those of other fruits except for FRAP. DPPH and ABTS radical scavenging activity from pomegranate were 93.00%, and 98.98%, respectively, at a concentration of 5 mg/mL, which were equal to those of ascorbic acid used for a positive control.

• Preventive Nutrition and Food Science
• /
• v.15 no.1
• /
• pp.51-56
• /
• 2010

The aim of this study is to examine the radical scavenging activity of perilla and sesame oil that Koreans traditionally consume. For DPPH radical scavenging activity, oil and its hexane/70% methanol extracts (ME) are used and for superoxide and hydroxyl radical scavenging activities, ME are used. Unrefined perilla oil, sesame oil, and refined sunflower oil are used. The yields for ME of perilla, sesame and sunflower oil are 0.57, 0.61, and 0.30%, respectively, and the amounts of phenolic compounds in ME of corresponding oil are 18.77, 88.64 and $0.05\;{\mu}g$ tannic acid/mg, respectively. $IC_{50}$ for DPPH scavenging activity of perilla, sesame and sunflower oil are 2.12, 1.91, and 3.35 mg/mL, respectively and those for ME of corresponding oils are 0.42, 0.07, and 43.11 mg/mL, respectively. In DPPH assay, the solvent used for oil sample is iso-octane and that for ME is methanol. Superoxide anion scavenging activity of ME of perilla, sesame and sunflower oil tested at 1 mg/mL concentration are 21.10, 13.25, and 3.14%, respectively. Hydroxyl radical scavenging activities of those samples tested at 1 mg/mL concentration are 86.08, 93.30, and 93.17%, respectively. In summary, the refining process seems to remove the phenolic compound during oil processing. Antiradical substances in perilla and sesame oils responsible for scavenging DPPH radicals are present in the methanol fraction, while the antiradical substances in the sunflower oil are in the lipid fraction. DPPH scavenging activity of ME of sesame oil is significantly higher than that of perilla oil (p<0.05). However, superoxide anion scavenging capacity of ME of perilla oils was found to be greater than that of both sesame and sunflower oils (p<0.05).

• Preventive Nutrition and Food Science
• /
• v.16 no.1
• /
• pp.12-17
• /
• 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 Food Science and Technology
• /
• v.40 no.3
• /
• pp.283-289
• /
• 2008

This study used response surface methodology (RSM) in an effort to optimize the hot water extraction conditions of dandelion leaves in order to increase antioxidant activity in the extract. A central composite design was applied to investigate the effects of independent variables, which included the ratio of solvent to sample ($X_1$), extraction temperature ($X_2$), and extraction time ($X_3$), on dependent variables of the extracts, including soluble solid ($Y_1$), total polyphenols ($Y_2$), total flavonoid ($Y_3$), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability ($Y_4$), 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging ability ($Y_5$), and superoxide radical scavenging ability ($Y_6$). The estimated optimal conditions were as follows: $83.77{\pm}1.07^{\circ}C$ of the extraction temperature, $20.85{\pm}0.24 mL/g$ of solvent per sample, and $1.59{\pm}0.12$ hr of extraction time. At the optimal conditions, the predicted characteristic values were: a yield of 38.98%, a total polyphenol level of $74.28{\mu}g/mg$, a total flavonoid level of $74.00{\mu}g/mg$, a DPPH radical scavenging ability ($IC_{50}$) of 0.14 mg/mL, a ABTS radical scavenging ability ($IC_{50}$) of 3.24 mg/mL, and a superoxide radical scavenging ability ($IC_{50}$) of 2.49 mg/mL.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.39 no.6
• /
• pp.783-788
• /
• 2010

The purpose of this study is to investigate the antioxidative activity and digestive enzyme inhibition of grape seed extract (GSE). The GSE was tested for its effect on various antioxidative potentials (scavenging activities of DPPH radical, superoxide anion radical and hydroxyl radical) and inhibitory effect of various digestive enzymes (trypsin, $\alpha$-chymotrypsin, $\alpha$-amylase, $\beta$-glucosidase and lipase). DPPH radical scavenging activity ($SC_{50}$, 50% scavenging concentration) of GSE was 4.76${\pm}$0.27 ppm while those of positive controls (EGCG and vitamin C) were 2.22${\pm}$0.12 ppm and 9.50${\pm}$0.72 ppm, respectively. $SC_{50}$ value of GSE against superoxide anion radical and hydroxyl radical were 3.82${\pm}$0.07 ppm and 803.23${\pm}$27.16 ppm, respectively. In addition, $IC_{50}$ values of GSE against trypsin, $\alpha$-chymotrypsin, $\alpha$-amylase, $\alpha$-glucosidase and lipase were 2.17${\pm}$0.59 ppm, 7.46${\pm}$1.25 ppm, 18.25${\pm}$3.54 ppm, 12.30${\pm}$1.12 ppm, and 653.23${\pm}$79.34 ppm, respectively. These results suggest that GSE may be useful for the prevention or treatment of obesity.

• Korean Journal of Microbiology
• /
• v.38 no.2
• /
• pp.81-85
• /
• 2002

A marine bacterium producing superoxide dismutase, strain number B446, was screened with nitrite quantitation method using hydroxy amine and photochemically generated superoxide ion, and the superoxide dismutase was purified through 35-75% ammonium sulfate precipitation, DEAE-Sephadex A-25 ion exchange chromatography, Sephadex G-200 gel filtration chromatography, and High-Q anion exchange chromatography to a yield of 6% and purification fold of 32.3.