• Advances in Traditional Medicine
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• v.10 no.4
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• pp.271-277
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• 2010

We tested to determine if Mori Cortex Radicis extract has antioxidant activities and its potential mechanism of action was explored. Anti-oxidative effects were tested by measuring free radical and nitric Oxide (NO) scavenging activity, and reducing power. Since iNOS and COX-2 are important enzymes responsible for the production of free radicals in the cell, Mori Cortex Radicis extract was tested as to whether it could inhibit iNOS and COX-2 expression in LPS stimulated Raw cells. 70% methanolic extract of Mori Cortex Radicis exerted significant DPPH free radical and NO scavenging activities. In addition, the Mori Cortex Radicis extract exerted dramatic reducing power with maximal activity observed at 1 mg/ml (11-fold over control). Production of iNOS induced by LPS was significantly inhibited by the Mori Cortex Radicis extract, suggesting it could inhibit NO production by suppressing iNOS expression. COX-2 induced by LPS was also significantly inhibited by the Mori Cortex Radicis extract. The extract contains well known antioxidant components including phenolics, flavonoids and anthocyanin at the concentration of 0.23 mg/g, 42.97 mg/g and 12.08 mg/g, respectively. These results suggest that 70% methanolic extract of Mori Cortex Radicis exerts significant anti-oxidant activity via inhibiting iNOS and COX-2 induction.

• Environmental Analysis Health and Toxicology
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• v.8 no.3_4
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• pp.33-41
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• 1993

This study was designed to determine the hemolytic mechanism of antitumor agent tetraphosphine platinum (II) complex (RC-1), which was synthesized recently. Erythrocytes treated with RC-1 showed concentration and time dependent lipid peroxydation, methemoglobin synthesis and hemolysis. And also treatment of radical scavengers showed the inhibitory effect of hemolysis and the decrease of malondialdehyde levels in RC-1 treated erythrocytes. So, the mechanism of hemolysis was considered to be the generation of free radicals, methemoglobin synthesis and the lipid peroxidation of phospholipid which composed of erythrocyte membrane.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.321-321
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• 2006

Aromatic diacetylenes form stable oligomeric diradicals when irradiated with UV light or heated at temperatures above their melting points. In this paper, the formation of stable diradicals is discussed, and the mechanism of polymerization in the presence of peroxide in solution, is discussed. The diphenyldiacetylene undergoes polymerization through coupling of diradicals, and not by the successive addition of radical species.

• Journal of the Korean Chemical Society
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• v.17 no.1
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• pp.1-9
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• 1973

The purpose of this paper is to investigate the mechanism of Diels-Alder reaction by assuming pseudo molecular complex (PMC) which has characters both of ionic and radical bonds. We treated this complex quantum-chemically as an intermediate between the configuration without charge transfer (radical bond character) and the configuration corresponding to the charge transfer from Diene (R) to Dienophile (S) (ionic bond character). The wave function for the complex could be expressed as: ${\psi}_{complex} = {\psi}(R,S) +{ \rho}{\psi}(R^+,S^-)$ where ${\rho}$ is the extent of charge transfer which is a constant to measure the ionic character of PMC. It has been noticed that${\rho}$is related to the difference between Fr + Fr' and Fs + Fs' in free valence (F) when R is united to S through atom r in R to atom s in S and atom r' in R to atom s' in S, That is, ${\rho}{\alpha}$ ${\Delta}F = (Fr + Fr') - (Fs + Fs')$. We have calculated ${\Delta}F$values for more than forty Diels-Alder reactions. The calculated values of ${\Delta}F$ is reversely proportional to the values of Brown's paralocalization energy (Lp) as well as Dewar's differences of delocalization energy$({\Delta}Edeloc.)$ with good linearity. This approach also presents a way of predicting the possibility and the easiness of diene synthesis between any two conjugate compounds. According to the considerations, it could be concluded that Diels-Alder reaction takes place through the united ionic-radical mechanism rather than the separated ionic or radical mechanism.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.1
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• pp.109-116
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• 2002

This study was performed to investigate the effect of kimchi intake on antiaging characteristics in liver of senescence-accelerated mouse (SAM) in terms of free radical production and anti-oxidative enzyme activities. Two hundred twenty SAM 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, mustard leaf added (30%) Korean cabbage kimchi diet (MKCK) group, and mustard leaf kimchi diet (MLK) group. Amount of freez-dried kimchi added to the diet was 5% that is equivalent to 50 g of fresh kimchi. Concentrations of total free radical, OH radical, $H_2O$$_2$in the liver significantly increased as aged (p<0.05). But those free radical concentrations from kimchi diet groups were lower than those of control (p<0.05). Among kimchi groups, MKCK and MLK groues showed greater inhibiting effect than KCK. Antioxidant enzyme activities of Cu, Zn-SOD, Mn-SOD, GSH-px, catalase and GSH/GSSG in kimchi groups were significantly increased (P

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.5
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• pp.1349-1355
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• 2005

The steamed root of Rehmannia glutinosa has been used for treatment of inner ear diseases, such as tinnitus and hearing loss in traditional Oriental Medicine. In the present study, we investigated the effect of ethanol extract of steamed root R. glutinosa (SRG) on cisplatin cytotoxicity of HEI-OC1 auditory cells. In addition, to investigate the mechanism of SRG on cisplatin cytotoxicity, the effects of SRG on lipid peroxidation as well as scavenging activities against various free radicals were measured in cisplatin-treated cells. Treatment of SRG protected cells from cisplatin and reduced lipid peroxidation in a dose-dependent manner. Furthermore, SRG demonstrated significant scavenging activity against various free radicals, including superoxide radical, hydroxyl radical, hydrogen peroxide, and DPPH radical. These results indicate that SRG protects cisplatin-induced damages of HEI-OC1 cells through inhibition of lipid peroxidation and augmenting scavenging activities against free radials.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.2
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• pp.462-467
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• 2007

The radix of Pueraria thunbergiana BENTHAM (Leguminosae) is traditionally prescribed to attenuate the clinical manifestations of inner ear dysfunction and various clinical situations including fever, gastrointestinal disorders, skin problems, migraine headaches, lowering cholesterol and treating chronic alcoholism in Oriental Medicine. In the present study, we examined the effect of ethanol extract of P. thunbergiana radix (EPR) on cisplatin-mediated HEI-OC1 auditory cell death. In addition, to investingate the protection mechanism of EPR on free radicals. Treatment of EPR protected cells from cisplatin and reduced lipid peroxidation in a dose-dependent manner. Furthermore, EPR demonstrated significant scavenging activity against various free radicals, including superoxide radical, hydroxyl radical, hydrogen peroxide, and DPPH radical. These results indicate that EPR protects cisplatin-induced damages of HEI-OC1 cells through inhibition of lipid peroxidation and augmenting scavenging activities against free radials.

• Biomedical Science Letters
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• v.8 no.3
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• pp.155-159
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• 2002

To evaluate the physiological significance of xanthine oxidase (XO) in rat skin, the activity of XO (type O) in skin was compared with that of small intestine or liver. Concomitantly, XO activities in some partial portions (scalp, leg, dorsal and ventral part) of skin were determined and then compared with each partial portion. XO activity of skin was lower than that of small intestine and rather higher than that of liver. Furthermore, the activity of XO in skin, after clipping of hairs and then in 5 days, was more increased than that of rat which was clipped before having been sacrificed. As for activities of free radical scavenging system (GPx, GST, SOD), skin is lower than liver and small intestine. Although it is hewn that the oxygen free radical generated by XO system lead to injurious effect on the cell, the XO activity of ventral part which is to be less exposed to xenobiotics and biological agents was the lowest among those of ventral, dorsal, leg and scalp parts in skin. In conclusion, it may be hypothesized that XO system in skin act on defence mechanism.

• YAKHAK HOEJI
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• v.45 no.3
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• pp.258-268
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• 2001

Garlic has been known to be effective against the gastrointestinal diseases which can be induced by production of oxygen-derived free radical. It has been shown that bamboo salt is effective on the treatment and prevention of various gastrointestinal disorders. Bamboo salt is a processed salt invented by a Korean, ll-Hoon Kim. It has been reported that garlic and bamboo-salt are useful to the treatment of gastric disorders in Korea. To clarify the protective mechanism of the garlic-bamboo salt mixture, the gas-tropathy was induced in rats with alcohol-salicylate and the activities of the free radical scavenging enzymes were examined. In this study, we found that the garlic-bamboo salt mixture reduced the severity of hemorrhagic lesion in gastric mucosa in the rats. In addition, the activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR) were significnatly increased and the total content of GSH was recovered. From those results, we concluded that the protective effect of the garlic-bamboo salt mixture on gastropathy in rats is its ability to recover the level of GSH and to increase the activities of the free radical scavenging enzymes (SOD, GPx, GR).

• Environmental Analysis Health and Toxicology
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• v.8 no.3_4
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• pp.23-32
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• 1993

This study was designed to elucidate the mechanism of nephrotoxicity caused by antitumor agent tetraphosphine platinum (II) complex (RC-1), which was synthesized as a tetraphosphine Pt (II) derivatives recently. Rats treated with RC-1 (20mg/kg/day) showed the increase of BUN value and malondialdehyde contents in kidney homogenate, compared to the control and which means the lipid peroxidation was a main cause of nephrotoxicity. In order to investigate the cytotoxic mechanism of RC-1, we also tested and revealed the generation of oxygen free radicals derived from neutrophil stimulated by RC-1 and interaction of the oxygen free radicals with the erythrocyte membrane. From the above results, we suggest that nephrotoxicity of general platinum (II) antitumor compounds as well as RC-1 were inhibited by radical scavengers.