• Preventive Nutrition and Food Science
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• v.7 no.1
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• pp.57-61
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• 2002

Electron spin resonance (ESR) spectroscopy was used to investigate the effect of irradiation dose and storage time on the free radical concentrations in gamma-irradiated dried seasoning powder. Seasoning powders of dried squid flavor, shrimp flavors, kimchi flavor, spicy beef soup flavor and soy sauce flavor were irradiated with doses of 0, 1, 3, 5, 7 and 9 kGy at room temperature using a Co-60 irradiator. Characteristic signals of free radicals were observed in all the irradiated samples of this experimental while these signals were not detected in non-irradiated samples. Since the free radical concentrations linearly increased with the applied doses (1~9 kGy), highly positive correlation coefficients ($R^2$ = 0.9285~0.9965) were obtained between irradiation doses and free radical concentrations during all the storage times. Free radical concentrations of the irradiated flavored seasoning powder did not change even at 16 weeks of storage at room temperature, while those of dried squid, shrimp and spicy beef soup flavors decreased until 2 weeks of storage after irradiation with 5 kGy or over, and these of soy cause flavors slowly decreased until 8 weeks of storage after irradiation with 3 kGy or over. Although the free radical concentrations decreased with storage times, the characteristic signals of the irradiated seasoning powders of dried squid, shrimp, spicy beef and soy sauce flavors were observed even after 16 weeks of storage at room temperature.

• Biomedical Science Letters
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• v.9 no.2
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• pp.75-84
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• 2003

To evaluate the influence of hepatic oxygen free radical systems on liver injury by topical p-phenylenediamine (PPD) application on rat skin, PPD (25 mg/16.5 $\textrm{cm}^2$) was topically applied to the abdominal region 5 times every other day and sacrificed. By PPD treatment, increasing rate of liver weight/body weight (%), serum activities of alanine aminotransferase and aspartate aminotransferase and decreasing rate of microsomal glucose-6-phosphatase activity were higher in the rats fed tungstate supplemented diet than those fed a standard diet. These findings indicate that group fed tungstate supplemented diet have more severe liver injury compared with group fed standard diet on topical PPD application. However, the activities of oxygen free radical generating enzymes such as xanthine oxidase (XO) and cytochrome P450 dependent aniline hydroxylase and those of oxygen free radical scavenging enzymes were not found to be different between these two animal groups. In the present study, a novel monitoring method to detect the generating of oxygen free radicals in liver extract was devised. Throughout this method, the oxidized PPD produced by oxygen free radicals was determined colorimetrically. The increasing rate of PPD oxidation by liver homogenate was higher in tungstate fed animals than in standard diet fed ones. Among the fractionations of liver extract, the mitochondrial and postmitochondrial fractions in the liver extract of tungstate fed animals led to a higher availability of PPD oxidation by PPD treatment compared with standard diet fed ones. In conclusion, these results suggest that an enhanced liver injury in tungstate fed animals treated with PPD may be due to oxygen free radicals produced in other systems except oxygen free radicals generating from cytosolic XO system. Especially, oxidative availability by PPD can be used for oxygen free radical detection in some tissue.

• Journal of Food Hygiene and Safety
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• v.14 no.2
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• pp.179-185
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• 1999

Previous studies have shown that methanol extract and its butanol fraction of Carthamus tinctorius L. Semen have the hepatoprotective effect on the CCl4-induced hepatotoxicity. The hepatoprotective effect of the subfractions of butanol fraction has been evaluated by analyzing oxygen free radical scavenging enzyme activities and histopathological examinations. In BS-5 subfraction treated group, the activity of superoxide dismutase has been significantly increased as compared with that of CCl4, treated rats. Antioxidant activity has been evaluated by the examination of the scavenging activity against 1,1-diphenyl-2-picrylhydrazyl radical. BS-5 subfraction has shown strong antioxidant activities. The histopathological examination showed that the treatment of BS-5 subfraction has relieved the ballooning degeneration of hepatocytes which had been generated by CCl4. It appears that the protective effect of BS-5 subfraction would be mediated of the attenuation of lipid peroxidation by acting as a free radical scavenger, which were based on the increase of superoxide dismutase activity.

• Biomedical Science Letters
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• v.5 no.1
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• pp.51-58
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• 1999

To evaluate an effect of liver damage on the dermal oxygen free radical metabolizing enzyme activities, the $CCl_4$ (0.1 ml/ 100 g body wt., 50% $CCl_4$ in olive oil) was intraperitoneally given to the rats every other day for 2 weeks. Based on the histopathological findings, liver weight (%), serum alanine aminotransferase, xanthine oxidase activities and hepatic lipid peroxide contents, the animals were induced severe liver damage. In the present liver damaged animal, all the activities of dermal scavenging enzymes such as superoxide dismutase, catalase and glutathione peroxidase were significantly decreased compared with central. And under the cytochemical electron microscopy the more coarse granules of cerrous perhydroxide were found compared with the control. In conclusion, the $CCl_4$-induced liver damage may influence upon the activities of some dermal oxygen free radical scavenging enzymes.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2000.04a
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• pp.6-7
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• 2000

Recently, free radicals such as active oxygen species, nitric oxide, etc are believed to be one of the key substances in physiological and pathological, toxicological phenomena, and oxidative damages, and all organism have defencing system against such as free radicals. Formation and extinction of free radicals may be regulated through bio-redox system, in which various enzymes and compounds should be involved in very complicated manner. Thus, direct and non-invasive measurement of in vivo free radical reactions with living animals must be essential to understand the role of free radicals in pathophysiological phenomena. Electron spin resonance spectroscopy (ESR) is very selective and sensitive technique to detect free radicals, but a conventional ESR spectrometer has large detect in application to living animals, since high frequent microwave is absorbed with water, resulting in generation of high fever in living body. In order to estimate in vivo free radical reactions in living whole animals, we develop in vivo ESR-CT technique using nitroxide radicals as spin probes. Nitroxide radicals and their reduced forms, hydroxylamines, are known to interact with various redox systems. We found that! ! the signal decay due to reduction of nitroxyl radicals is influenced by aging, inspired oxygen concentration, ischemia-referfusion injury, radiation, etc. In the present paper, I will introduce in vivo ESR technique and my laboratory recent results concerning non-invasive evaluation of free radical reactions in living mice.

• Preventive Nutrition and Food Science
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• v.12 no.3
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• pp.177-180
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• 2007

Tocotrienols (T3) are minor plant constituents found abundantly in rice bran, which provide a significant source of vitamin E in animal feeds. T3 was reported to have an intrinsic hypocholesterolemic effect by inhibiting HMG-Co A reductase. It has similar antioxidative properties as tocopherols in food and biological system due to their similar chemical structures. However, the antioxidant activity and mechanism of T3 to scavenge free radicals and to inhibit the peroxidation of linoleic acid are less understood. The purpose of this study was to investigate the scavenging effect of T3 on free radicals and its inhibition of peroxide formation. Free radical scavenging activity was monitored by the DPPH (1,1-diphenyl-2-picrylhydrazyl) method whereas inhibition of linoleic acid peroxidation was evaluated using the thiocyanate method. Thiobarbituric acid (TBA) test was used to determine malonaldehyde formation from linoleic acid peroxidation. Free radical scavenging activity increased with increasing concentration levels of T3. T3 exhibited 38.2, 78.6, 92.7 and 96.2% radical scavenging activity at concentrations of 2, 8, 32 and 128 ppm, respectively. At 128 ppm, it was highly effective in inhibiting linoleic acid peroxidation. The activity of T3 evaluated by the thiocyanate method showed low absorbance values indicating a high level of antioxidant activity. All treatments showed similar trends in antioxidant activity when evaluated by both the thiocyanate method and TBA test.

• Advances in Traditional Medicine
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• v.8 no.3
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• pp.260-265
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• 2008

Annona reticulata belonging to the family Annonaceae is traditionally used as anthelmintic and it is reported to have anticancer activity. Free radicals are known to be involved in various types of diseases like cancer, diabetes, neurological disorders etc. The present study was aimed to evaluate free radical scavenging property of methanol extract of the leaves of Annona reticulata in some in vitro models e.g. DPPH, nitric oxide, superoxide and lipid peroxide radical model. The extract showed good dose-dependent free radical scavenging property in all the models. $IC_{50}$ values were found to be 3.22, 170.01, 25.12 and $140.12\;{\mu}g/ml$ respectively in DPPH, nitric oxide, superoxide and lipid peroxidation inhibition assays. Reductive ability of the extract was also tested based on potassium ferricyanide reduction where dose dependant reducing capability was observed. Measurement of total phenolic compounds by Folin-Ciocalteu's phenol reagent indicated that 1mg of the extract contained $146.20\;{\mu}g$ equivalent of pyrocatechol. The findings ascertain promising free radical scavenging property of the extract and the antioxidant property of the extract may be due to the high content of phenolic compounds.

• Bulletin of the Korean Chemical Society
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• v.17 no.11
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• pp.1009-1018
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• 1996

A study on the application of vinyl radical cyclization via free radical allylation reaction in the synthesis of various carbocyclic compounds is described. In connection with this study, a new allyl transfer reagent, 2-bromo-3-(phenylthio)propene 1 is developed and it was shown that vinyl radical cyclization through free radical allylation reaction using reagent 1 provides a valuable approach to carbocyclic systems with a reactive exo-alkylidene moiety, which is advantageous for further transformations.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.1
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• pp.117-123
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• 2002

This study was Performed to investigate the effect of kimchi intake on antiaging characteristics in the brain of senescence-accelerated mouse (SAM) in terms of free radical production and anti-oxidative enzymes. Two hundreds twenty SAM (20 mice) were divided into four groups and fed kimchi diet for 12 months. Experimental groups were kimchi free AIN-76 diet (control) group, Korean cabbage kimchi diet (KCK)group, 30% mustard leaf added Korean cabbage kimchi diet (MKCK) group, and mustard leaf kimchi diet (MLK) group. Concentrations of total free radical, OH radical and $H_2O_2$ of control group increased up to 123%, 262% and 174% of initial value (p<0.05) after one year. Increase in free radical production in kimchi groups due to aging was decreased by kimchi feeding. Among kimchi groups. MKCK and MLK groups showed greater inhibiting effect against free radical production than KCK. The concentration of TBARS in the bruin of control group also significantly increased up to 362% of initial value as aged (p<0.05) and production of TBARS in kimchi groups were decreased. When the activities of Cu, Zn-SOD, Mn-SOD, GSH-px and catalase of kimchi groups were compared to those of control at the same experimental period, anti-oxidative enzyme activities of kimchi groups were lower than those of control (p<0.05). But GSH/GSSG in kimchi groups were higher compared to control. In conclusion, decrease in free radical production and increase in anti-oxidative enzyme activities were observed from kimchi groups suggesting that kimchi might have important role on retarding aging. Among kimchi variety tested in this experiment, MKCK and MLK seem to have greater effect on inhibiting free radical production and increasing anti-oxidative enzyme activities than KCK.

• Korean Journal of Food Science and Technology
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• v.35 no.1
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• pp.121-124
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• 2003

Optimal extraction condition and free radical scavenging effect of ethanol extracts of Olympia grape (Vitis labruscana L.) seeds and skins were determined. Extraction yield of grape seeds increased with increasing extraction temperature increased, but was not affected by ethanol concentration in grape skins. Highest extraction yields obtained with 100% ethanol concentration at $78^{\circ}C$ were 36 and 49.5% in seeds and skins, respectively. Ethanol extract of grape seeds obtained at $78^{\circ}C$ showed stronger $RC_{50}\;(409.7\;{\mu}g/mL)$ than that of grape skins. Among organic solvent fractions, ethylacetate fraction obtained from ethanol extract of grape seed showed the strongest $RC_{50}\;(136.7\;{\mu}g/mL)$. Overall, ethanol extracts of grape seeds and their organic fractions showed significantly stronger free radical scavenging effect than those of skin extracts.