• Nutrition Research and Practice
• /
• v.6 no.6
• /
• pp.491-498
• /
• 2012

Glycyrrhiza uralensis (or licorice) is a widely used Oriental herbal medicine from which the phenylflavonoids dehydroglyasperin C (DGC), dehydroglyasperin D (DGD), and isoangustone A (IsoA) are derived. The purpose of the present study was to evaluate the antioxidant properties of DGC, DGD, and IsoA. The three compounds showed strong ferric reducing activities and effectively scavenged DPPH, $ABTS^+$, and singlet oxygen radicals. Among the three compounds tested, DGC showed the highest free radical scavenging capacity in human hepatoma HepG2 cells as assessed by oxidant-sensitive fluorescent dyes dichlorofluorescein diacetate and dihydroethidium bromide. In addition, all three compounds effectively suppressed lipid peroxidation in rat tissues as well as $H_2O_2$-induced ROS production in hepatoma cells. This study demonstrates that among the three phenylflavonoids isolated from licorice, DGC possesses the most potent antioxidant activity, suggesting it has protective effects against chronic diseases caused by reactive oxygen species as well as potential as an antioxidant food additive.

• Environmental Mutagens and Carcinogens
• /
• v.25 no.3
• /
• pp.97-103
• /
• 2005

The genotoxic effect of antimalarial drugs amodiaquine (AQ), mefloquine (MQ) and halofantrine (HF) was investigated in.at liver cells using the alkaline comet assay. AQ, MQ and HF at concentrations between $0-1000{\mu}mol/L$ significantly increased DNA strand breaks of rat liver cells dose-dependently. The order of induction of strand breaks was AQ>MQ>HF. The rat liver cells exposed to AQ and HF (200 and 400 ${\mu}mol/L$) and treated with (Fpg) the bacterial DNA repair enzyme that recognizes oxidized purine showed greater DNA damage than those not treated with the enzyme, providing evidence that AQ and HF induced oxidation of purines. Such an effect was not observed when MQ was treated with the enzyme. Treatment of cells with catalase, an enzyme inactivating hydrogen peroxide, decreased significantly the extent of DNA damage induced by AQ, and HF but not the one induced by MQ. Similarly quercetin, an antioxidant flavonoid at $50{\mu}mol/L$ attenuated the extent of the formation of DNA strand breaks by both AQ and HE. Quercetin, however, did not modify the effects of MQ. These results indicate the genotoxicity of AQ, MQ and HF in rat liver cells. In addition, the results suggest that reactive oxygen species may be involved in the formation of DNA lesions induced by AQ and HF and that, free radical scavengers may elicit protective effects against genotoxicity of these antimalarial drugs.

• Biomolecules & Therapeutics
• /
• v.16 no.1
• /
• pp.9-13
• /
• 2008

Some pharmacological activities of Ulmus davidiana var. japonica were evaluated using its methanol extract (UDE). An acute anti-inflammatory activity of UDE was assessed using carrageenan-induced hind paw edema in rats. UDE exhibited an antioxidant activity when assayed by a stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH). Dose-dependent anti-nociceptive activity of UDE was assessed using the acetic acid-induced writhing test in mice. UDE was able to diminish the reactive oxygen species (ROS) level in the lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells. UDE also suppressed production of nitric oxide and induction of inducible nitric oxide synthase and cyclooxygenase-2 in the stimulated macrophages cells. collectively, the results imply that U. davidiana var. japonica has antioxidant and anti-nociceptive activities in addition to anti-inflammatory activity.

• Journal of the Korean Applied Science and Technology
• /
• v.20 no.2
• /
• pp.141-147
• /
• 2003

Oxidized polyethylene wax is obtained by oxidation of polyethylene wax and it is composed of various chemicals, e.g., fatty acid, alcohol, ketone and ester. The application of oxidized polyethylene wax is determined by the composition of these chemical substances. In this basic study we observed the basic reaction parameters of time, temperature, oxygen concentration and catalysts on the oxidation reaction of low molecular weight polyethylene(PE wax) by analyzing the acid value, physical and chemical properties of oxidized PE wax to develop a new oxidation process. Acid values are increased with temperature increase in the rage of $150^{\circ}C^{\sim}180^{\circ}C$ but decreased beyond 190$^{\circ}C$. Acid values are also increased with oxygen concentration. As the oxidation reaction proceeds the molecular weight and softening points of oxidation products are decreased by cracking reaction, but the viscosities are increased. To observe the crystallinity of oxidation products SEM experiment was performed. To obtain a high acid-value product in a mild condition, we adopted free radical catalysts and the acid value of the product using catalyst was higher than the product obtained without catalyst in the same reaction condition. The effective initiators were dicumyl peroxide(DCPO), t-butylperoxy-2-ethyl hexanoate(HOPO) and benzoyl peroxide(BPO) having long half-life.

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
• /
• 2002.05a
• /
• pp.138-138
• /
• 2002

Oxidative stress has been associated with a number of diseases in human. Among the sources that can generate oxidative stress, it has been reported that iron can generate reactive oxygen species (ROS)with thiol. In iron overload state, increased thiol levels in plasma appeared to be associated with human mortality. In this study we examined whether iron could interact with thiols in plasma, generating ROS. In human plasma, unlike with Fe(III), Fe(II) increased lucigenin-enhanced chemiluminescence in concentration-dependent manner, and this was inhibited by SOD. Boiling of plasma did not affect chemiluminescence induced by Fe(II). Hovever, thiol depletion in plasma by pretreatment with N-ethylmaleimide (NEM)decreased Fe(II)-induced chemiluminescence significantly, suggesting that Fe(II) generated superoxide anion by the nonenzymatic reaction with plasma thiol. Consistent with this findings, albumin, the major thiol contributor in plasma, also generated ROS with Fe(II) and this generation was inhibited by pretreatment with NEM. Treatment with Fe(II) to plasma resulted un significant reduction of oxygen radical absorbance capacity (ORAC) value, suggest that total antioxidant capacity could diminished in iron overload state. In conclusion, In iron overload state, plasma may be affected by oxidative stress mediated by nonenzymatic reaction of Fe (II)with plasma thiol.

• Clinical and Experimental Pediatrics
• /
• v.50 no.8
• /
• pp.746-752
• /
• 2007

Purpose : Total hydroperoxide (TH), free radical-mediated oxidation product can be used as a measure of free radical injury. The aim of the present study was to see if preterm newborns are at increased risk for oxidative stress compared with term newborns, and to determine whether oxidative stress during postnatal first 1 week is associated with clinical outcomes in preterm infants. Methods : Serum TH levels of preterm infants (n=39) were compared with those of term infants (n=24) on the postnatal day 1. Among the preterm infants, serum TH levels of uncomplicated group (n=23) were also compared with those of complicated group (n=16) who developed oxygen radical related diseases on the postnatal day 1 and 7. Retrospective analysis was performed to find out risk factors for oxygen radical injuries based on birth history, laboratory data, neuroimaging findings and clinical progress in two preterm groups. Results : Serum TH levels on postnatal day 1 were higher in the preterm infant group than the term infant group. Serum TH levels on postnatal day 1 in the complicated preterm infant group were significantly higher compared with uncomplicated group, but there was no significant difference in serum TH levels on postnatal day 7. Also, there was no significant difference in serum TH levels between uncomplicated preterm infants and term infants. Serum TH level on postnatal day 1 was independently associated with higher morbidity after adjusting for gestational age, Apgar score (5 min), arterial blood gas analysis. Conclusion : Complicated preterm newborns are at increased risk for oxidative stress compared with uncomplicated newborns and term newborns. Oxidative injury during the prenatal or postnatal day 1 is associated with adverse outcomes in preterm infants. Elevated TH levels on postnatal day 1 may have a value to predict clinical outcomes in preterm infants.

• Journal of the Korean Applied Science and Technology
• /
• v.26 no.1
• /
• pp.87-92
• /
• 2009

In this study, we evaluated anti-oxidation and whitening effects of Ligularia stenocephala extract for use as the cosmeceuticals. L. stenocephala was extracted by three different solvents which was n-Hexane, ethyl acetate, $H_{2}O$. The free radical (1,l-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity of extract of L. stenocephala was in the order: ethyl acetate fraction of leaf ($IC_{50}$ value of 10.512ug/mL) > ethyl acetate fraction of stem ($IC_{50}$ value of 31.877ug/mL) > $H_{2}O$ fraction of leaf ($IC_{50}$ value of 129.194ug/mL). Reactive oxygen species (ROS) scavenging activity of extract of L. stenocephala was in the order: ethyl acetate fraction of leaf ($IC_{50}$ value of 0.230mg/mL) > ethyl acetate fraction of stem ($IC_{50}$ value of 0.528mg/mL) > $H_{2}O$ fraction of leaf ($IC_{50}$ value of 0.799mg/mL). Tyrosinase inhibition activity of L. stenocephala extracts was reduced 29.477% on ethyl acetate fraction of leaf, 13.583% on ethyl acetate fraction of stems. Therefore, L. stenocephala extracts may be useful as a new antioxidant and whitening agent to inhibit melanogenesis.

• The Journal of Internal Korean Medicine
• /
• v.22 no.1
• /
• pp.63-71
• /
• 2001

Objectives : Cordyceps Sinensis (CS) was tested for the effects of antioxidant enzymes and lipid peroxidation in the liver. Methods : We measured the changes in body weight, enzyme activity, lipid peroxide and the death rate in the hydrocortisone acetate-treated rats. Results : In vitro, CS didn't effect levels of lipid peroxide. the activities, and the ratio of type conversion of xanthine oxidase. In the hydrocortisone acetate-treated rats, lipid peroxide, the activities, the ratio of type conversion of xanthine oxidase, and the death rate all increased. But, glutathione peroxidase and superoxide dismutase decreased. In vitro, after CS was administered to hydrocortisone acetatetreated rats, the levels of lipid peroxide in the liver, and the death rate decreased. However, the activities, and the ratio of type conversion of xanthine oxidase decreased. The body weight, glutathione peroxidase, and superoxide dismutase in+creased. The effects of Sinensis Cordyceps Broth did better than the effects of Sinensis Cordyceps Mycelia. Conclusions : These results suggest that CS decrease the activities of free radical generating enzymes which form lipid peroxide and increase the activities of oxygen free radical scavenging enzymes.

• Journal of Korean Medicine Rehabilitation
• /
• v.24 no.4
• /
• pp.15-28
• /
• 2014

Objectives This study was carried out to find out the Antioxidant and Anti-inflammatory Effects of Components of Mahwangbujaseshin-tang in LPS-Stimulated RAW264.7 Macrophages. Methods There are 5 experimental groups. ; normal, control, EH (Ephedrae Herba), ALRP (Aconiti Lateralis Radix Preparata) and AR (Asiasari Radix). The extract of EH, ALRP and AR ($100{\mu}g/ml$) was added to each group. We examined cytotoxicity, total phenolic contents, DPPH and ABTS free radical scavenging activity, Intracellular ROS (reactive oxygen species) production, NO (Total Nitric oxide), iNOS (inducible nitric oxide synthase), PGE2 (prostaglandin E2), COX-2 (cyclooxygenase-2), $IL-1{\beta}$ ($interleukin-1{\beta}$), IL-6 (interleukin-6), $TNF-{\alpha}$ (tumor necrosis factor-${\alpha}$), MMP-9 (matrix metalloproteinase-9), TIMP-1 (tissue inhibitor of metalloproteinase-1) and HO-1 (heme oxygenase-1) expression level. Results 1. Total phenolic contents of EH were in the highest level. 2. DPPH and ABTS free radical scavenging activity of EH was in the highest level. 3. ROS production was significantly decreased in AR. 4. NO production was significantly decreased in EH, ALRP, AR and iNOS expression was decreased in EH, AR. 5. PGE2 and COX-2 expression was decreased in EH, AR. 6. $IL-1{\beta}$ production was significantly decreased in EH, AR and IL-6 production was significantly decreased in AR. $TNF-{\alpha}$ production was significantly decreased in ALRP, AR. 7. MMP-9 and TIMP-1 production were significantly decreased in EH. 8. HO-1 expression was significantly increased in EH. 9. With simultaneous usage of SnPP which is expression inhibitor of HO-1, NO, $IL-1{\beta}$, IL-6 and $TNF-{\alpha}$ production were partially increased in EH, ALRP, AR. Conclusions According to this study, Components of Mahwangbujaseshin-tang have anti-oxidants and anti-inflammation effects in LPS-Stimulated RAW264.7 Macrophages.

• Bulletin of the Korean Chemical Society
• /
• v.35 no.3
• /
• pp.770-774
• /
• 2014

The bond dissociation energy (BDE) of the chemical bond between the carbon and oxygen atoms of a simple TEMPO-derivative is calculated by employing the density functional theory, the $2^{nd}$ order M${\phi}$ller-Plesset (MP2) perturbation theory, and complete basis set (CBS) methods. We find that BDE of the positive ion of the TEMPO-derivative is larger at least by 7 kcal/mol than that of the negative ion, which implies that the dissociation reaction rate of the positive ion should be slower than that of the negative ion. Such theoretical predictions are contrary to the results of our previous experiments (Anal. Chem. 2013, 85, 7044), in which the larger energy was required for negative o-TEMPO-Bz-C(O)-peptides to undergo the dissociation reactions than for the positive ones. By comparing our theoretical results to those of the experiments, we conclude that the dissociation reaction of o-TEMPO-Bz-C(O)-peptide should occur in a complicated fashion with a charge, either positive or negative, probably being located on the amino acid residues of the peptide.