• Journal of Photoscience
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• 제9권2호
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• pp.221-224
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• 2002

Carcinogenesis can be theoretically divided to intiation step and promotion step. Intiation associates with genetic alterations including p53 tumor suppressor gene and ras oncogene. Promotion involves in clonal expansion of of an initiated cell by epigenetic mechanism, mainly through signal transduction and gene expression. Ultraviolet light (UV) acts as both initiator and promoter. Initiation is closely related with DNA damage induced by UV, including cyclobutane pyrimidine dimers, (6-4) photoproducts and 8-hydroxy-2'-deoxyguanosine. Cyclobutane pyrimidine dimers and (6-4) photoproducts are directly induced by UV, while 8-hydroxy-2'-deoxyguanosine is induced indirectly by the reactive oxygen species. Because initiation is an irreversal genetic event, while promotion is a reversal and epigenetic event, to know the molecular mechanisms of tumor promotion in UV-carcinogenesis is crucial to develop preventive medicine and suppress UV-carcinogenesis. Because ROS is also involved in signal transduction of the cell, anti-oxidant could be the good candidate of anti-promoting agent. Here, we describe the suppressive effect of UV-carcinogenesis by various anti-oxidant including olive oil. In addition, we discuss about the mechanism of UVB-induced expression of cyclooxygenase-2, which might be a representative molecule involved in promotion of UV-carcinogenesis.

• Asian-Australasian Journal of Animal Sciences
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• 제33권5호
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• pp.722-731
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• 2020

Objective: Two experiments were conducted using 28 healthy multiparous sows to evaluate the oxidative stress status and reproductive performance of sows during gestation and lactation under different thermal environments. Methods: Fourteen multiparous sows were used in Exp. 1 under a high thermal environment, and the other 14 multiparous sows were used in Exp. 2 under a moderate thermal environment. In both experiments, reproductive performances of sows were recorded. Plasma samples were collected on d 35, 60, 90, and 109 of gestation, and d 1 and 18 of lactation for malondialdehyde, protein carbonyls, 8-hydroxy-deoxyguanosine, immunoglobulin g (IgG), and IgM analysis. Results: For sows in Exp. 1, plasma malondialdehyde concentration on d 109 of gestation tended to be greater (p<0.05) than it on d 18 of lactation. Plasma concentration of protein carbonyl on d 109 of gestation was the greatest (p<0.05) compared with all the other days. Plasma concentrations of 8-hydroxy-deoxyguanosine on d 109 of gestation was greater (p<0.05) than d 18 of lactation in Exp. 1. For sows in Exp. 2, there was no difference of malondialdehyde and protein carbonyl concentration during gestation and lactation. In both Exp. 1 and 2, litter size and litter weight were found to be negatively correlated with oxidative stress indicators. Conclusion: Sows under a high thermal environment had increased oxidative stress during late gestation indicating that increased oxidative damage to lipid, protein, and DNA could be one of the contributing factors for reduced reproductive performance of sows in this environment. This study indicates the importance of providing a moderate thermal environment to gestating and lactating sows to minimize the increase of oxidative stress during late gestation which can impair reproductive outcomes.

• Journal of Nutrition and Health
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• 제39권7호
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• pp.610-616
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• 2006

This study was performed to investigate the effect of whole mandarin, peel or pulp intake of Citrus unshiu Marc. on antioxidative capacity and oxidative DNA damage in fifteen-month aged rats. Forty-eight male Sprague-Dawley rats $(621.9\;{\pm}\;10.1\;g)$ were blocked into four groups according to their body weights as control group, whole mandarin powder group, mandarin peel powder group and mandarin pulp powder group. Rats were raised with diets containing 5% (w/w) freeze dried mandarin formulations for four weeks. Total polyphenol content and total antioxidant status (TAS) of mandarin formulations were highest in peel powder, followed by whole powder and then pulp powder. The 8-hydroxy2'-deoxyguanosine concentrations of kidney in all mandarin groups were significantly lower than that of control group, and that of mandarin peel group was much lower than whole powder and pulp groups. Plasma TAS levels of all the experimental groups were higher than that of control group, and among mandarin groups, peel group showed higher level than remaining two groups. In conclusion, all the mandarin formulations were effective on antioxidative capacity in fifteen-month aged rats, and the peel was most effective one among three formulations.

• 대한수의학회지
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• 제47권1호
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• pp.25-32
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• 2007

Houttuynia cordata root on non-lipid oxidative damage. The antioxidative efects of methanolic (MeOH) extract of Houttuynia cordata rooton non-lipid, including liposome oxidation, oxidation of deoxyribose, protein oxidation, chelating, scavenging,and 2'-deoxyguanosine (2'dG) oxidation were investigated. Houttuynia cordata root exhibited highantioxidative effect in a liposome model system. The inhibitory effect of MeOH extract on deoxyribosedamage exhibited antioxidative effect and it afforded considerable protection against damage to deoxyribose.In addition, MeOH extract at over 300extracts exhibited metal binding ability for hydrogen peroxide. Furthermore, the oxidation of 2'dG to 8-hydroxy-2-deoxyguanosine was inhibited by MeOH extracts, and scavenging activity for hydroxyl radicalexhibited a remarkable effect. The present results on biological model systems showed that MeOH extractswas effective in the protection of non-lipids against various oxidative model systems.

• Archives of Pharmacal Research
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• 제13권3호
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• pp.252-256
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• 1990

Oxidative damage to DNA can be caused by excited oxygen species, which are produced by radiation or are by-products of aerobic metabolism. Endogenous evels of 8-hydroxy-2'deoxyguanosine (8-OH-dG), an adduct that results from the damage of DNA caused by hydroxyl radical,have been detected in E. coli and S. typhimurium. Treatment of bacterial cells with various concentrations of hydrogen peroxide caused a moderate increase in the 8-OH-dG content. The enzymatic release of 8-OH-dG from asocorbate/Cu(II)-treated DNA was effected by an extract of E. coli cells. These results indicate that 8-OH-dG is formed in vivo inbacterial DNA through endogenous oxidative mechanisms and on treatment with an oxygen radical-producing agent and that it is repairable.

• BMB Reports
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• 제28권3호
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• pp.249-253
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• 1995

The nonenzymatic glycation of copper, zinc-superoxide dismutase (Cu,Zn-SOD) led to inactivation and fragmentation of the enzyme. The glycated Cu,zn-SOD was isolated by boronate affinity chromatography. The formation of 8-hydroxy-2'-deoxyguanosine (8-OH-dG) in calf thymus DNA and the generation of strand breaks in pBhiescript plasmid DNA by a metal-catalyzed oxidation (MCO) system composed of $Fe^{3+}$, $O_2$, and glutathione (GSH) as an electron donor was enhanced more effectively by the glycated CU,Zn-SOD than by the nonglycated enzyme. The capacity of glycated Cu,Zn-SOD to enhance damage to DNA was inhibited by diethylenetriaminepentaacetic acid (DETAPAC), azide, mannitol, and catalase. These results indicated that incubation of glycated CU,Zn-SOD with GSH-MCO may result in a release of $Cu^{2+}$ from the enzyme. The released $Cu^{2+}$ then likely participated in a Fenton-type reaction to produce hydroxyl radicals, which may cause the enhancement of DNA damage.

• Journal of Nutrition and Health
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• 제55권3호
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• pp.348-358
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• 2022

본 연구는 한국에서 최초로 시행되는 연구로서, 성인 제2형 당뇨환자에서 혈청 AGEs의 농도에 따라 두 군으로 나눈 뒤 신체계측 및 체조성, 영양소 섭취량, 생화학적 지표를 비교 분석한 연구이다. Low AGEs group과 High AGEs group의 평균 AGEs는 각각 0.4 ± 0.2, 3.4 ± 1.7 ng/mL로 나타났다. 항산화 효소인 HO-1은 High AGEs group이 Low AGEs group에 비해 유의적으로 높게 나타났다. 또한, 전체 연구참여자를 대상으로 연령과 성별을 보정한 후 상관관계를 분석한 결과, 혈청 HO-1 농도와 혈청 AGEs 농도 및 소변 8-OHdG 농도는 양의 상관관계를 가지는 것으로 나타났다. 본 연구를 통해 혈청 HO-1은 당뇨환자 특이적 지표인 AGEs와 더불어 DNA 손상 지표에도 예민하게 반응하는 것을 확인하였으며, 추후 한국 당뇨환자의 산화적 스트레스와 합병증 연구의 근거자료로 널리 사용될 수 있을 것으로 사료된다.

• Archives of Pharmacal Research
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• 제29권3호
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• pp.213-217
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• 2006

The present study was undertaken to test the hypothesis that dietary antioxidants protect DNA damage induced by peroxynitrite, a potent physiological inorganic toxin. The present study showed that dietary antioxidants such as (-)-epigallocatechin gallate, quercerin, rutin, resveratrol, and ursolic acid inhibit single strand breaks in supercoiled plasmid DNA induced by 3-morpholinosydnomine N-ethylcarbamide (SIN-1), a generator of peroxynitrite through the reaction between nitric oxide and superoxide anion. The formation of 8-hydroxy-2'-deoxyguanosine (8-OH-dG) in calf thymus DNA by SIN-1 was also inhibited by dietary antioxidants. When U937 cells were incubated with 1 mM SIN-1 bolus, a significant increase of 8-OH-dG level was observed. However, oxidative DNA damage was significantly lower in the cells pre-treated with dietary antioxidants when cells were exposed to SIN-1.

• 한국식품영양과학회지
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• 제33권1호
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• pp.22-27
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• 2004

인진쑥의 방사선에 의한 산화적 손상에 대한 DNA 방어효과를 확인하기 위하여 마우스 림프구에서 단세포전기영동법과 CHO 세포에서 미소핵 형성 시험 그리고 마우스의 간과 흉선 조직의 DNA에서 8-OHdG의 형성정도를 관찰하였다. 그 결과 단세포전기영동법 및 미소핵 형성 시험에서는 50 $\mu\textrm{g}$/mL의 농도에서 가장 높은 DNA 손상 억제 효과를 나타내었으며, 8-OHdG 형성 정도는 간과 흉선 모두 30 mg/kg 농도 투여군에서 높은 방어효과를 나타내었다. 이상의 결과에서 인진쑥 추출물은 DNA 상해를 효과적으로 방어하였고 특히, 기존에 알려진 방사선 방호물질에 비하여 독성이 적은 천연물이라는 관점에서 방사선 방어제로 적용이 가능할 것으로 사료된다.

• Toxicological Research
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• 제20권3호
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• pp.213-223
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• 2004

This work aimed to study the effectiveness of cellular oxidative parameter (malondial-dehyde, protein carbonyl, and 8-hydroxy-2'deoxyguanosine). The experimental groups were aluminum treated rats and control rats. Aluminum treatd rats were given intraperitoneally aluminum nitrate nonahydrate ($Al^{3+}$, 0.2 mmol/kg) daily for 30 days except Sunday. Control rats were injected 1 ml of saline. After the dose, rats were decapitated and hippocampus and cerebral cortex were removed. The measured parameters were tissue malondialdehyde (MDA, index of lipid peroxidation), protein carbonyl (index of protein oxidation), 8-hydroxy-2'-deoxy-guanosine (8-OHdG, index of DNA oxidation), reduced glutathione (GSH) levels as well as glutathione reductase (GR) and catalase. AI concentrations in the tissues were also measured. All results were corrected by tissue protein levels. The results were as followed; 1. The concentrations of AI in the cortex and hippocampus were significantly higher in the AI-treated rats than in the control rats. 2. Antioxidative enzyme's activity, catalase and GR, were significantly higher in the AI-treated rats than the control rats. GSH levels were also higher in the AI-treated rats. 3. MDA, protein carbonyl, and 8-OHdG concentration of AI-treated rats were significantly higher than those of control rats. 4. The concentrations of antioxidants, and oxidative stress parameter were correlated with the concentrations of AI in hippocampus and cerebral cortex. Catalase and GR activity were also correlated with the concentration of AI. Based on these results, it can be suggested that intraperitoneally injected AI was accumulated in the brain and induced the increase of antioxidant levels and antioxidative enzyme activity. Also, the oxidative products of cellular macromolecules are significantly related to tissue AI concentration. Therefore MDA, protein carbonyl, and 8-OHdG are useful markers for oxidative stress on cellular macromolecules.