• Korean Journal of Pharmacognosy
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• v.35 no.4 s.139
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• pp.357-363
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• 2004

Flavonoids are class of polyphenolic compounds widely distributed in the plant kingdom, which display a variety of biological activities, including antiviral, antithrombotic, antiiflammatory, antihistaminic, antioxidant and free-radical scavenging abilities. To determined flavonoid, myricetin in the presence of other antioxidants - vitamin C and vitamin E - can exert antioxidative properties not only directly by modulating the AOE system but also scavenging free radical, we investigated cell viability, antioxidant enzyme activities and ROS level in B16F10 murine melanoma cell. B16F10 cells were exposed to medium containing myricetin in the presence or absence of vitamin C or vitamin E for a period of 24 hr. Cell viability was measured by MTT assay. In co-treating myricetin with other antioxidants, CAT activities were increased, compared with control, but SOD and GPx activities were decreased, compared with each antioxidant treated groups . In the group of myricetin or myricetin present with other antioxidants, ROS levels were decreased dose-dependently. Especially, myricetin present of other antioxidants were decreased compared with myricetin.

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

• Advances in Traditional Medicine
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• v.3 no.4
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• pp.205-211
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• 2003

Stem bark of Cinchona sp. (Rubiaceae) is one of the well known drugs for its therapeutic values in traditional as well as modern medicine. Even though a lot of work has been carried out on quinoline alkaloids of Cinchona, its phenolic constituents received very little attention. In the present study, we evaluated antioxidant properties of C. officinalis stem bark methanolic extract and water extract containing phenolic compounds (total phenolics 21.37, 5.18% w/w respectively in the two extracts) in different in vitro and ex vivo models viz., antiradical activity by DPPH reduction, superoxide radical scavenging activity in riboflavin/light/NBT system, nitric oxide radical scavenging activity in sodium nitroprusside/Greiss reagent system and inhibition of lipid peroxidation induced by iron-ADP-ascorbate in liver homogenate and haemolysis of erythrocytes induced by phenylhydrazine in erythrocyte membrane stabilization study. Both the extracts exhibited very good antioxidant activity in all the models tested. The phenolic compounds including tannins present in the stem bark seem to offer protection from the oxidative damage.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.1069-1076
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• 2005

The oil crises in 1973 and 1979 caused considerable effort to decrease the fuel consumption. As a result, the main engine had been changed through the shape(from loop scavenging air system to uniflow scavenging air system), higher compression ratio, low speed and long stroke. It is difficult to make a various engine satisfied with all owner's request. So manufacturer could find a way that can change the rating through large range from the engine already manufactured. These ways are tried through large range to change rpm to 72% and engine's output to 48% of MCR with keeping the normal engine's shape almost. The important element considered in the process of derated output of the main engine is to recover the beginning overcapitalization as soon as possible through low SFOC. In this paper, it is compared and considered between rating and derating engine with several data about modifying rating which have been done by engine manufacturer so far. And the selection process of derating engine is studied also.

• CELLMED
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• v.4 no.4
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• pp.26.1-26.9
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• 2014

Reactive oxygen species are known to mediate various pathological conditions associated with malaria. In this study, the antioxidant potential of Clerodendrum violaceum leaf extracts, an indigenous antimalarial remedy, was evaluated. Total phenol, flavonoid, selenium, vitamins C and E contents of Clerodendrum violaceum leaf extracts were determined. The free radical scavenging activities of the extracts against DPPH, superoxide anion and hydrogen peroxide coupled with their reducing power were also evaluated in vitro. Moreover, responses of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) in a rodent malaria model to a 4-day administration of Clerodendrum violaceum leaf extracts were also evaluated. The methanolic extract was found to contain the highest amounts of antioxidant compounds/element and also demonstrated the highest free radical scavenging activity in vitro. The results showed a significant decrease (p < 0.05) in SOD and CAT activities with a concurrent significant (p < 0.05) increase in GPx and GR activities in both erythrocytes and liver of untreated Plasmodium berghei NK65-infected animals compared to the uninfected animals. The extracts were able to significantly increase (p < 0.05) SOD and CAT activities and significantly reduce (p < 0.05) GPx and GR activities in both the liver and erythrocytes compared to those observed in the untreated infected animals. The results suggest the augmentation of the antioxidant system as one of the possible mechanisms by which Clerodendrum violaceum extract ameliorates secondary effects of malaria infection, alongside its antiplasmodial effect in subjects.

• Korean Journal of Acupuncture
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• v.25 no.4
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• pp.89-104
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• 2008

Objectives : This study was undertaken to determine the in vitro antioxidant activity of the extract of Chilgitang herb-acupuncture solution (CHAS). Methods : The radical scavenging capacity was tested by 2,2-diphenyl-1-picryl-hydrazyl (DPPH), hypoxanthine-xanthine oxidase system, DCFH-DA assay, nitric oxide and peroxynitrite generating system. In addition, antioxidant activity on copper and AAPH mediated human low-density lipoprotein (LDL) oxidation was measured by using TBARS assay and relative electrophoretic mobility assay. The amount of total phenolic compounds was assayed by the Folin-Ciocalteu method. Results : CHAS revealed a potent scavenging activity on DPPH radical(82%), superoxide anions(73%), hydroxyl radical(63%), nitric oxide (99%) and peroxynitrite (99%). Moreover, CHAS showed a strong inhibitory effect (59%) on $FeCl_2$-ascorbic acid induced lipid peroxidation of rat liver homogenate. CHAS also markedly inhibited copper(81%) and AAPH(56%)-mediated LDL oxidation, and effectively suppressed the electrophoretic mobility during exposure of human LDL to copper ions. CHAS (82 mg/g) contained higher concentration of total phenolic compounds than that of water extract (45 mg/g) obtained from Chilgitang. Conclusions : These results indicate that CHAS may protect against ROS- or RNS involved diseases, including cardiovascular diseases.

• Herbal Formula Science
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• v.10 no.2
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• pp.127-141
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• 2002

Objectives: Haeganjeon(HGJ) has been used for the treatment of liver disease in traditional medicine. The present study was carried out to evaluate the antioxidant and protective effects of HGJ extract on oxidative damage of hepatocytes by tert-butyl hydroperoxide(t-BHP). Methods: In the linoleic acid water-alcohol system, the levels of lipid peroxide(LPO) were determined by TBA method. The scavenging effect of HGJ on ${\alpha},{\alpha}-diphenyl-{\beta}-picrylhydrazyl$(DPPH) radical was determined according to the method of Hatano. In the Fenton system(ferrous ion reaction with hydrogen peroxide), the levels of hydroxyl radical induced LPO in rat liver homogenate were determined according to the method of TBA. Inhibitory effect of HGJ on superoxide generation was measured by xanthine-xanthine oxidase system. In order to evaluate antioxidative activity of HGJ in the liver cell, cultured normal rat liver cells(Ac2F) were prepared and incubated with or without HGJ. After 18hr, cells placed in DMEM medium without serum, and then incubated with 1mM tert-butyl hydroperoxide(t-BHP) for 2hrs. Viable cells were detected by MTT assay. Conclusions: In the linoleic acid autoxidation system, HGJ extract significantly inhibited the time course of the lipid peroxidation. These effects were similar to those of BHA HGJ extracts showed about 70% scavenging effect on DPPH radical. And HGJ extract inhibited the lipid peroxide formation in rat liver homogenate induced by hydroxyl radical derived from Fenton system. In addition, HGJ extract protected the cell death induced by t-BHP and significantly increased cell viability in the normal rat liver cell. These result indicated that HGJ extract might playa protective role against oxidative hepatic cell injury by means of free radical scavenger.

• The Korea Journal of Herbology
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• v.27 no.6
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• pp.7-13
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• 2012

Objectives : Reactive oxygen species (ROS) have been associated with pathogenic processes including carcinogenesis through direct effect on DNA directly and by acting as a tumor promoter. Therefore, it has been regarded that ROS may be a major target for cancer prevention. The root of Paeonia lactiflora pall (PL), a traditional Chinese herb, has been a component of effective prescriptions for treatment of liver disease. Also, there are some reports about the antioxidant activities of the extracts from PL. However, little has been known about the effects of PL against oxidative damage. This work aimed to elucidate the anti-oxidant effects of Paeonia lactiflora pall (PL) in the non-cellular system and cellular system. Methods : Antioxidant activities of PL were evaluated by hydroxyl radical scavenging assay and $Fe^{2+}$ chelating assay. Anti-oxidative effect of PL was evaluated by ${\varphi}X$-174 RF I plasmid DNA cleavage assay in non-cellular system. In addition, DNA migration assay, expression level of phospho-H2AX, MTT assay and lipid peroxidation assay were performed for evaluate the anti-oxidative effect of PL in cellular system. Results : PL had a dose-dependent hydroxyl radical scavenging and $Fe^{2+}$ chelating capacity. In addition, PL inhibited oxidative DNA and cell damage induced by hydroxyl radical in non-cellular system and cellular system. Conclusion : Taken together, P. lactiflora pall may be possible for the application to a potential drug for treating the oxidative diseases such as cancer.

• Journal of the Korean Society of Tobacco Science
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• v.14 no.2
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• pp.168-195
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• 1992

Pulmonary system is a target organ and primary defense mechanism against environmental oxidants and polutants. Enzymatic and nonenzymatic antioxdant defense mechanisms undoubtedly protect the lung from oxidants even endogenous oxidative stress. In addition, new ways of augmenting pulmonary antioxidant defenses are developed, which can be used to support the intrinsic antioxidants. Therefore, improved understanding of antioxidant defense mechanisms will increase our knowledge of the cause and will suggest rational approaches for treating and preventing oxidant-induced lung injury. In this review, we discuss the formation and scavenging of free radicals, and the strategies for antioxidant defense of pulmonary system.

• Herbal Formula Science
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• v.9 no.1
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• pp.289-317
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• 2001

The purpose of this study was to reseach the effect of Daesihotang and its component groups on diabetes, free radical and antioxidative defense system in alloxan-induced diabetic rats. The experimental group was divided into three groups: Daesihotang (DS), Soyangyak (DS1), Yangmyungyak (DS2). The results were obtained as follows: The level of glucose, triglyceride, total cholesterol, creatinine in serum were considerablely reduced by Daesihotang. And the level of HDL cholesterol, albumin, total protein in serum were increased by Daesihotang significantly. And the level of BUN has some decreased, but with no significancy. In the study of Daesihotang on free radical scavenging effect in vitro, it has shown that Daesihotang and its components group have significant suppressing effect on peroxidation of linoleic acid on concentration. And in other experiments as scavenging effect of DPPH radical, inhibitory effect of superoxide in xanthine-xanthine oxidase system and inhibitory effect on lipid peroxidation reaction by hydroxy radical in $H_2O_2-Fe^{2+}$ system, Daesihatang have some activity, but with no significancy. In the study of Daesihotang on antioxidative defense system in vivo, the activity of GOT and GPT in serum were significantly increased; and the amounts of lipid peroxide in serum was reduced significantly but in liver no significancy. In hepatic catalase activity, Daesihotang has showed significant effect. In the level of hepatic glutathione, Daesihotang increased the amount of glutathione significantly. And in the activity of glutathione-s-transferase, Daesihotang has decreasing effect but has no significancy. These result suggest that Daesihotang has strong effect on diabetes and it is useful to prevent diabetes, but has less effect on peroxidative damage by free radical.