• The Korea Journal of Herbology
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• v.26 no.4
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• pp.95-99
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• 2011

Objective : In this study, we demonstrate the protective effect on oxidative DNA damage of leaf extracts from Abeliophylli distichi Folium via its antioxidant activity for the establishment of new value for the herbal medicine. Methods : Abeliophylli distichi Folium leaves were extracted with hot-water and ethylacetate (EtOAC). The 1,1-diphenyl-2- picrylhydrazyl (DPPH) radical and hydroxyl scavenging assay and $Fe^{2+}$ chelating assay were performed for antioxidative effect and ${\varphi}$X-174 RF I DNA cleavage assay and intracellular DNA damage assay were used for inhibitory effect of intracellular DNA damage. Results : In DPPH, Hydroxyl radical scavenging activity and $Fe^{2+}$ chelating activity of EtOAC extracts were 94.72%, 62.88%, 41.13%, and hot-water extracts were 88.86%, 56.7%, 37.4% at 200 ${\mu}g/m{\ell}$, respectively. Also, those extracts showed protective effect of DNA damage against the oxidative stress. Conclusion : These results indicated that the leaf extracts of Abeliophylli distichi Folium can be used as a natural antioxidants, which effectively inhibits the oxidative DNA damage.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2329-2332
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• 2007

Salsolinol, endogenous neurotoxin, is known to be involved in the pathogenesis of Parkinson's disease (PD). In the present study, we have investigated the oxidative damage of DNA induced by the reaction of salsolinol with Cu,Zn-SOD. When plasmid DNA incubated with salsolinol and Cu,Zn-SOD, DNA cleavage was proportional to the concentrations of salsolinol and Cu,Zn-SOD. The salsolinol/Cu,Zn-SOD system-mediated DNA cleavage was significantly inhibited by radical scavengers such as mannitol, ethanol and thiourea. These results indicated that free radicals might participate in DNA cleavage by the salsolinol/Cu,Zn-SOD system. Spectrophotometric study using a thiobarbituric acid showed that hydroxyl radical formation was proportional to the concentration of salsolinol and was inhibited by radical scavengers. These results indicated that hydroxyl radical generated in the reaction of salsolinol with Cu,Zn-SOD was implicated in the DNA cleavage. Catalase and copper chelators inhibited DNA cleavage and the production of hydroxyl radicals. These results suggest that DNA cleavage is mediated in the reaction of salsolinol with Cu,Zn-SOD via the generation of hydroxyl radical by a combination of the oxidation reaction of salsolinol and Fenton-like reaction of free copper ions released from oxidatively damaged SOD.

• The Korea Journal of Herbology
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• v.25 no.4
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• pp.55-59
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• 2010

Objective : This study was conducted to investigate the antioxidant activity and inhibitory effect on oxidative DNA damage of Nelumbinis Semen Extracts Methods : Nelumbins semen were extracted with hot-water and ethylacetate (EtOAC). The 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radical scavenging assay and $Fe^{2+}$ chelating assay were performed for antioxidative effect and ${\phi}X$-174 RF I DNA cleavage assay and intracellular DNA damage assay were used for inhibitory effect on intracellular DNA damage. Results : In DPPH, Hydroxyl radical scavenging activity and $Fe^{2+}$ chelating activity of EtOAC extracts were 96.22%, 53.53%, 64.72%, while those of hot-water extracts were 20.86%, 10.72%, 29.74% at $200{\mu}g/m{\ell}$, respectively. In ${\phi}X$-174 RF I plasmid DNA cleavage assay, the protective effects of EtOAC and hot-water extracts against oxidative DNA damage were 76% and 6% at $200{\mu}g/m{\ell}$, respectively. Conclusion : These results indicated that the seed extracts of Nelumbo nucifera can be used as a natural antioxidants, which effectively inhibits the oxidative DNA damage.

• Korean Journal of Plant Resources
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• v.22 no.3
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• pp.195-202
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• 2009

Schisandra chinensis have been traditionally used in Asia for the treatment of dyspnea, cough, mouth dryness, spontaneous diaphoresis, nocturnal diaphoresis, nocturnal emission, dysentery, insomnia and amnesia. The purpose of this study is to evaluate the protective effects of Schisandra chinensis on oxidative DNA damage and lipid peroxidation induced by ROS in non cellular and cellular system. DPPH radical, hydroxyl radical and hydrogen peroxide scavenging assay were used to measure the antioxidant activities. Phi X-174RF I plasmid DNA cleavage assay and intracellular DNA migration assay were used to evaluate the protective effect on oxidative DNA damage. MTT assay and lipid peroxidation assay were used for evaluating the protective effect on oxidative cell damage. It was found to scavenge DPPH radical, hydrogen peroxide and hydroxyl radical and it inhibited oxidative DNA damage, lipid peroxidation and cell death induced by hydroxyl radical. These data indicate that Schisandra chinensis possesses a spectrum of antioxidant and DNA-protective properties

• BMB Reports
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• v.46 no.4
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• pp.225-229
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• 2013

Methylglyoxal (MG) is an endogenous metabolite which is present in increased concentrations in diabetics and reacts with amino acids to form advanced glycation end products. In this study, we investigated whether ferritin enhances DNA cleavage by the reaction of MG with lysine. When plasmid DNA was incubated with MG and lysine in the presence of ferritin, DNA strand breakage was increased in a dose-dependent manner. The ferritin/MG/lysine system-mediated DNA cleavage was significantly inhibited by reactive oxygen species (ROS) scavengers. These results indicated that ROS might participate in the ferritin/MG/lysine system-mediated DNA cleavage. Incubation of ferritin with MG and lysine resulted in a time-dependent release of iron ions from the protein molecules. Our data suggest that DNA cleavage caused by the ferritin/MG/lysine system via the generation of ROS by the Fenton-like reaction of free iron ions released from oxidatively damaged ferritin.

• Bulletin of the Korean Chemical Society
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• v.34 no.2
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• pp.367-373
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• 2013

The ruthenium(II) ferrocenyl heterocyclic thiosemicarbazone complexes of the type $[RuCl(CO)(EPh_3)]_2L$ (where E = P/As; L = binucleating monobasic tridendate thiosemicarbazone ligand) have been investigated. Strutural features were determined by analytical and spectral techniques. Binding of these complexes with CT-DNA by absorption spectral study indicates that the ruthenium(II) complexes form adducts with DNA and has intrinsic binding constant in the range of $3.3{\times}10^4-1.2{\times}10^5M^{-1}$. The complexes exhibit a remarkable DNA cleavage activity with CT-DNA in the presence of hydrogen oxide and the cleavage activity depends on dosage.

• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.2873-2876
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• 2010

Excess free iron generates oxidative stress that may contribute to the pathogenesis of various causes of neurodegenerative diseases. Previous studies have shown that one of the primary causes of increased brain iron may be the release of excess iron from intracellular iron storage molecules. In this study, we attempted to characterize the oxidative damage of DNA induced by the reaction of ferritin with $H_2O_2$. When DNA was incubated with ferritin and $H_2O_2$, DNA strand breakage increased in a time-dependent manner. Hydroxyl radical scavengers strongly inhibited the ferritin/$H_2O_2$ system-induced DNA cleavage. We investigated the generation of hydroxyl radical in the reaction of ferritin with $H_2O_2$ using a chromogen, 2,2'-azinobis-(2-ethylbenzthiazoline-6-sulfonate) (ABTS), which reacted with ${\cdot}OH$ to form $ABTS^{+\cdot}$. The initial rate of $ABTS^{+\cdot}$ formation increased as a function of incubation time. These results suggest that DNA strand breakage is mediated in the reaction of ferritin with $H_2O_2$ via the generation of hydroxyl radicals. The iron-specific chelator, deferoxamine, also inhibited DNA cleavage. Spectrophotometric study using a color reagent showed that the release of iron from $H_2O_2$-treated ferritin increased in a time-dependent manner. Ferritin enhanced mutation of the lacZ' gene in the presence of $H_2O_2$ when measured as a loss of $\alpha$-complementation. These results indicate that ferritin/$H_2O_2$ system-mediated DNA cleavage and mutation may be attributable to hydroxyl radical generation via a Fenton-like reaction of free iron ions released from oxidatively damaged ferritin.

• Korean Journal of Medicinal Crop Science
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• v.24 no.6
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• pp.464-470
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• 2016

Background: Valeriana fauriei (Valerianaceae) has been used to as a traditional medicine to treat a variety of symptoms, including headache, insomnia, hypertension, and menstrual irregularity. However, the present study investigates the species' antioxidant activity and its inhibition of oxidative DNA damage, which have yet to be studied. Methods and Results: The antioxidant activity was assessed using radical scavenging assays with 1,1-diphenyl-2-picryl hydrazyl (DPPH) and, 2, 2'-azino-bis (3-ethylbenzothiazoline-6 sulfonic acid) diammonium salt (ABTS) and a reducing power assay. The total phenol content was also analyzed, and phenolic compounds were detected using HPLC/UV, whereas the inhibitory effect of Valeriana fauriei on oxidative DNA damage was measured using ${\phi}-174$ RF I plasmid DNA cleavage assay. The DPPH and ABTS radical scavenging activity were $75.17{\pm}3.55%$ and $95.83{\pm}0.63%$, repectively, and the reducing power was $93.14{\pm}1.74$ at $200{\mu}g/m{\ell}$. The total phenol content was $10.24{\pm}0.04mg/g$, whereas chlorogenic acid, catechin, caffeic acid and epicatechin were identified using HPLC/UV, and the ${\phi}-174$ RF I plasmid DNA cleavage assay indicated that V. fauriei provided protection against oxidative damage. Conclusions: The results of the present study suggest that V. fauriei has powerful antioxidant activity that can provide protective effects against the oxidative DNA damage caused by free radicals. The species, therefore, provides a valuable resource for the development of natural pharmaceutical to treat aging, cancer, and degenerative diseases.

• BMB Reports
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• v.39 no.4
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• pp.452-456
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• 2006

To elaborate the peroxidase activity of cytochrome c in the generation of free radicals from $H_2O_2$, the mechanism of DNA cleavage mediated by the cytochrome c/$H_2O_2$ system was investigated. When plasmid DNA was incubated with cytochrome c and $H_2O_2$, the cleavage of DNA was proportional to the cytochrome c and $H_2O_2$ concentrations. Radical scavengers, such as azide, mannitol, and ethanol, significantly inhibited the cytochrome c/$H_2O_2$ system-mediated DNA cleavage. These results indicated that free radicals might participate in the DNA cleavage by the cytochrome c and $H_2O_2$ system. Incubation of cytochrome c with $H_2O_2$ resulted in a time-dependent release of iron ions from the cytochrome c molecule. During the incubation of deoxyribose with cytochrome c and $H_2O_2$, the damage to deoxyribose increased in a time-dependent manner, suggesting that the released iron ions may participate in a Fenton-like reaction to produce $\cdot$OH radicals that may cause the DNA cleavage. Evidence that the iron-specific chelator, desferoxamine (DFX), prevented the DNA cleavage induced by the cytochrome c/$H_2O_2$ system supports this mechanism. Thus we suggest that DNA cleavage is mediated via the generation of $\cdot$OH by a combination of the peroxidase reaction of cytochrome c and the Fenton-like reaction of free iron ions released from oxidatively damaged cytochrome c in the cytochrome c/$H_2O_2$ system.

• Korean Journal of Plant Resources
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• v.24 no.2
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• pp.130-138
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• 2011

In this study, we evaluated the protective effects of the hot water extract from red bean (Phaseolus angularis) against oxidative DNA and cell damage induced by hydroxyl radical. The antioxidant activities were evaluated by hydroxyl radical and hydrogen peroxide scavenging assay, and $Fe^{2+}$-chelating assay. Although the extract with hot water didn't scavenge the hydroxyl radical, it removed and chelated hydrogen peroxide and ferrous iron necessary for the induction of hydroxyl radical by 71% and 64% at 200 ${\mu}g/ml$, respectively. Its protective effect on oxidative DNA damage was carried using ${\Psi}$X-174 RF I plasmid DNA comparing the conversion level of supercoiled form of the plasmid DNA into open-circular form and linear form and the expression level of phospho-H2AX in NIH 3T3 cells. In ${\Psi}$X-174 RF I plasmid DNA cleavage assay, it inhibited oxidative DNA damage by 96% at 200 ${\mu}g/ml$. Also, it decreased the expression of phospho-H2AX by 50.1% at 200 ${\mu}g/ml$. Its protective effect against oxidative cell damage was measured by MTT assay and the expression level of p21 protein in NIH 3T3 cells. In MTT assay for the protective effect against the oxidative cell damage, it inhibited the oxidative cell death and the abnormal cell growth induced by hydroxyl radical. Also, it inhibited p21 protein expression by 98% at 200 ${\mu}g/ml$. In conclusion, the results of the present studies indicate that hot water extract from red bean exhibits antioxidant properties and inhibit oxidative DNA damage and the cell death caused by hydroxyl radical.