• Journal of Nutrition and Health
• /
• v.38 no.7
• /
• pp.553-560
• /
• 2005

The purpose of this study was to examine the lipid peroxidation, plasma antioxidant status and insulin resistance in childhood obesity. To this end, we measured blood lipid profiles, glucose, insulin concentrations, plasma antioxidant vitamins, baseline conjugated diene formation as a measure of LDL oxidation in vivo and TRAP (total radical trapping antioxidant potential) of 93 school children (58 nonobese, 35 overweight-obese). Insulin resistance was estimated by homeostasis model assessment of insulin resistance (HOMA-IR). The overweight-obese children showed significantly higher levels of leptin (p < 0.0001) and triglyceride (p < 0.05) and significantly lower level of plasma Iycopene (p < 0.001) and $\gamma$-tocopherol (p < 0.05) compared with the normal weight children. Furthermore, the levels of TRAP were significantly lower in overweight-obese children (p < 0.05). Significant positive relationships between plasma leptin and conjugated dienes formation (p < 0.005) and inverse relationship between plasma leptin and lipid corrected levels of $\beta$-carotene (p < 0.05), Iycopene (p < 0.05) were observed. Our results showed an increased lipid peroxidation and decreased antioxidant capacity in childhood obesity which could be involved in the atherosclerotic process.

• Korean Journal of Pharmacognosy
• /
• v.38 no.1
• /
• pp.31-36
• /
• 2007

In this study, we have investigated the antioxidant activities of the leaves of Smilax china Linne in order to find the antioxidant substances which has an scavenging effect of reactive oxygen species (ROS) from natural products. As a result, EtOAc and n-BuOH extracts of the leaves of Smilax china Linne exhibited potent antioxidant effect on various antioxidant experiment. The major components of antioxidant activity were isolated from EtOAc and n-BuOH extracts of the leaves of Smilax china Linne. Their structure of compounds were identified as kaempferol-7-O-${\alpha}$-L-rhamnopyranoside and kaempferol-3,7-O-${\alpha}$-L-dirhamnopyranoside by spectroscopic evidence, respectively. Antioxidant activities were observed in kaempferrol-7-O-${\alpha}$-L-rhamnopyranoside at 23 ${\mu}g$ and in kaempferol-3,7-O-${\alpha}$-L-dirhamnopyranoside at 27 ${\mu}g$ as concentration of DPPH 50% reduction.

• Asian-Australasian Journal of Animal Sciences
• /
• v.23 no.6
• /
• pp.742-749
• /
• 2010

We investigated the antioxidant efficacy of quercetin (0% Diet 1, 0.25% Diet 2, and 0.5% Diet 3) pretreatment for 30 and 60 days in response to cadmium (Cd) toxicity in the olive flounder, and measured the plasma lysozyme activity to understand the immune effects of quercetin. The lysozyme activity with Diets 2 and 3 was higher than with Diet 1. Based on this result, to examine the immune ability and antioxidant role of quercetin, we exposed olive flounder fed quercetin to Cd and then measured the expression and activity of antioxidant enzymes (superoxide dismutase (SOD) and catalase (CAT)) and lipid peroxidation (LPO). With Diets 2 and 3, the expression and activity of antioxidant enzymes and the $H_2O_2$ concentration were lower than with Diet 1. In addition, the LPO levels were lower than with Diet 1, which protected the cell membrane. Therefore, quercetin removed the reactive oxygen species (ROS) produced by Cd, indicating that quercetin has antioxidant ability. In addition to its antioxidant ability, quercetin has immune effects.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.19 no.1
• /
• pp.1-9
• /
• 1986

In order to isolate and clarify the antioxygenic substances from the browning reaction products, the antioxidant activity of various amino acids and their browning reaction products were measured when they were reacted with xylose. Among nonpolar amino acids Met and Trp appeared to have stronger antioxidant effect than others. Most of polar and basic amino acids, however, did not have antioxidant activity. Ser and Cys showed a rather slight prooxidant effect. The browning reaction products of Trp and His had a higher level of antioxidant activity than that they were reacted as free amino acids. But the browning product of Met did not show the antioxidant activity. When all amino acids were divided on their polar characteristics, the higher optical density of the browning reaction products showed, the stronger antioxidant activity revealed.

• Journal of Microbiology and Biotechnology
• /
• v.31 no.1
• /
• pp.33-42
• /
• 2021

Due to the potential of antioxidants to scavenge free radicals in human body, it is important to be able to prepare antioxidant peptides that meet the industrial requirements for cosmetics and food. Here, we determined in vivo/in vitro activities of antioxidant peptide from P. fucata (PFAOP) prepared by bio-fermentation method. The antioxidant property test results showed the DPPH, hydroxyl, superoxide radical-scavenging, and cellular antioxidant activity. EC50 values of PFAOPs were 0.018 ± 0.005, 0.126 ± 0.008, 0.168 ± 0.005, and 0.105 ± 0.005 mg/ml, respectively, exhibiting higher antioxidant activities than glutathione (p < 0.05). Moreover, anti-proliferation and cytotoxicity activity results illustrated PFAOP has a potent anti-proliferative activity against HepG2, Caco-2, and MCF-7 carcinoma cells with no cytotoxicity. Moreover, the protocols we developed in this work demonstrated several excellent advantages in PFAOP preparation compared to enzymatic hydrolysis or chemical synthesis methods and provide a theoretical foundation for higher-value application of marine-derived functional peptides.

• Korean Journal of Plant Resources
• /
• v.29 no.6
• /
• pp.642-649
• /
• 2016

This study was conducted to investigate the antioxidant activity in the leaves and stems of 50 tomato accessions, in order to examine the possibility of using tomato by-products as a functional material. The extracts of the leaves (LE) and stems (SE) were analyzed for DPPH, ABTS, and total polyphenol content (TPC). Antioxidant activities and TPC differed significantly between the LE and SE of the 50 tomato accessions. TPC in LE and SE showed wide variation, ranging from 24.4 to 60.6 and 12.5 to 18.8 mg GAE/g, respectively. The DPPH and ABTS antioxidant activities of LE ranged from 10.0 to 38.2% (scavenging effect) and 20.8 to 59.0 mg ASC/g, respectively, while the DPPH and ABTS measurements of SE were 1.4 to 8.8% and 2.2 to 22.5 mg ASC/g, respectively. As assessed by the relative antioxidant capacity index (RACI), IT033117 and IT203466 had the highest antioxidant activity in LE and SE, respectively. These results will expand the knowledge of antioxidant activity and provide information on tomato accessions valuable for the development of functional foods and food additives.

• Culinary science and hospitality research
• /
• v.24 no.2
• /
• pp.103-111
• /
• 2018

The objectives of the present study were to examine the antioxidant activity of autofocusing fractions from egg white protein hydrolysates and obtain higher antioxidant peptide fraction, which could be applied to the food model system. Alkaline protease hydrolysate of egg white protein exerted higher antioxidant activities than other protein hydrolysates and were fractionated on the basis of the amphoteric nature of sample peptides by preparative isoelectric focusing without toxic solvents and reagents, which is termed autofocusing. Neutral and basic fractions showed higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity than the acidic fractions. The acidic and neutral fractions showed higher hydroxyl (OH) radical scavenging activity and oxygen radical absorbance capacity (ORAC) values than the basic fractions. The acidic fractions showed higher metal chelating activity than basic fractions. Antioxidant activities of some autofocusing fractions except for ORAC showed higher compared to the crude hydrolysate. These results suggest that peptides fractions from egg white protein are effective antioxidant, and that autofocusing could be useful to increase antioxidant activity for application to food system.

• 전기의세계
• /
• v.22 no.4
• /
• pp.30-34
• /
• 1973

The main purporse of this paper is to study on the influence of temperature effect on electrical-properties, i.e., dielectric breakdown voltage, dielectric constant and resitivity of homemade insulating oil containing antioxidant. Transformer oil manufactured in Korea is taken for a sample, and this sample is classified into seven samples in which antioxidant is contained and not contained, and antioxidant is divided into three kinds of amount: 0.3%, 0.5%, 0.8%. Changing the tempe5rature of the samples by oil bath, the electric properties measured from the samples are as follows: (1) the variation of either the dielectric breakdown voltage or the resistivity are considerably large, but the dielectric constants are almost unchanging. (2) In view of electrical characteristic, the deterioration rate of the samples containing antioxidant is somewhat lower than that of other samples. (3) Nearly the same value is shown in the dielectric-breakdown voltage of the samples, in which contained the different amount of antioxidant: 0.3%, 0.5%, 0.8%, but the decrease rate of resitivity is lowest, 0.3%, of all. As the result of the experiment, This study can suggest that 0.3% be the optimum amount of antioxidant which will be added transformer oil manufactured in Korea and is useful for the understanding about the electrical properties of transformer oil containing antioxidant.

• Korean Journal of Agricultural Science
• /
• v.45 no.3
• /
• pp.499-508
• /
• 2018

To use mountain ginseng adventitious roots (MGAR), which is superior in functionality compared to ginseng, and to mass produce raw materials as a functional cosmetic material, the antioxidant and cosmeceutical activities of the extracts of MGAR at different ethanol concentrations (0, 20, 40, 60 and 80%) were compared and analyzed. At first, different ethanol concentrations were compared to determine the best solvent for the extraction of phenolic compounds from MGAR. An 80% ethanol extract with 10.07 mg of gallic acid equivalents/g sample and 0.94 mg of quercetin equivalents/g sample was the best solvent in the extraction of phenolic compounds. However, the 60% ethanol extract had the highest antioxidant activity, evident by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, Trolox equivalent antioxidant capacity (35.01 mM Trolox/g sample) and ferric reducing antioxidant power (460.94 mM $FeSO_4/g$ sample). However, the inhibitory activities of the 80% ethanol extract from the MGAR against tyrosinase and elastase were higher than those of the other extracts. The results of this study show that the extract of MGAR can be used as an easily accessible source of natural antioxidant and as a possible cosmetic ingredient in the cosmeceutical industry. However, the components responsible for the antioxidant and cosmeceutical activities of the MGAR extracts are currently unclear. Therefore, it is suggested that further studies should be carried out to isolate and identify the antioxidant and cosmeceutical components in MGAR.

• Korean journal of food and cookery science
• /
• v.18 no.6
• /
• pp.603-612
• /
• 2002

The study was carried out to compare the relation between the color intensity and antioxidant activity of caramelization products using xylose(XY), glucose(GL). sucrose(SU), glucose＋citric acid(GLCA), glucose＋sodium citrate(GLSC), heated at 80, 120 and 140$\^{C}$ for 24hrs, respectively. The color intensity(absorbance at 490nm) of the browning mixtures increased as the browning temperature and time increased. But the degrees of color intensity of SU and GLCA changed very little. The hydrogen donating ability(HDA) of browning reaction products was generally enhanced as the browning temperature and time increased. When browning mixtures were heated at 80$\^{C}$, the HDA of GLGC was the highest, but the HDA of GLSC was the highest when heated at 120 and 140$\^{C}$. The antioxidant activities for the corn oil substrate containing the anhydrous ethanol extracts from the browning mixtures was inferior to that of SU, but was superior to that of GLCA. The relations among the color intensity, the antioxidant activity, and the hydrogen donating ability(HDA, reducing power) of the browning reaction mixtures were as follows: As the color intensity increased, the antioxidant activity decreased. The correlation coefficient of the color intensity and the antioxidant activity by regression equation was -0.73 ∼ -0.82. As the reducing power increased, the antioxidant activity decreased. The correlation coefficient between the reducing power and the antioxidant activity by regression equation was -0.98 ∼ -0.99. Therefore, the antioxidant activity of browning reaction mixtures seemed not correlated with the color intensity and the reducing power.