• Journal of Life Science
• /
• v.17 no.2 s.82
• /
• pp.230-234
• /
• 2007

Oxygen is required for many important aerobic cellular reactions, it may undergo electrontransfer reactions, which generate highly reactive membrane-toxic intermediates (reactive oxygen species, ROS), such as hydrogen peroxide, singlet oxygen, superoxide radical, hydroxyl radical, hydroperoxyl radical, hydroxy ion. Various mechanisms are available to protect cells against damage caused by oxidative free radicals, including scavenging enzyme systems such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). This antioxidant defense system is a very complex and finely tuned system consisting of enzymes capable of detoxifying oxygen radicals as well as low molecular weight antioxidants. In addition, repair and turnover processes help to minimize subcellular damage resulting from free radical attack. $H_2O_2$,one of the major ROS, is produced at a high rate as a product of normal aerobic metabolism. The primary cellular enzymatic defense systems against $H_2O_2$ are the glutathione redox cycle and catalase. From Northern blot analysis of total RNAs from cultured cell with $H_2O_2$ treatment, various results were obtained. Expression of Cu/Zn SOD decreased when cell passage increased, but the level of the Cu/Zn SOD was scarcely expressed in 35 passage.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.31 no.3
• /
• pp.500-505
• /
• 2002

Many studies have shown that hyperglycemia leads to an increase of lipid peroxidation in diabetic patients and animals, reflecting a rise reactive oxygen species production. It is increasingly recognized that brain is another site of diabetic organ damage. Accordingly, this study was to investigate the effect of dandelion on oxygen free radical generating and scavenging system of brain in streptozotocin (STZ)-induced diabetic rats. Male Wistar rats were divided into diabetic (control) and diabetic-dandelion supplemented groups. Dandelion was supplemented for 4 weeks with dandelion leaf and root powder (DLP, DRP) or dandelion leaf and root water extract (DLW, DRW) based on 11.4 g of raw dandelion/kg diet. Diabetes was induced by single injection STZ (55 mg/kg B.W., i.p.)in a citrate buffer. Oxygen free radical generating enzymes, cytochrome P-450, amino-pyrine N-demethylase, aniline hydroxylase and xanthine oxidase, were lowered in dandelion supplemented-groups compared to the control group. Superoxide dismutase, catalase and gluthathione peroxidase activities of brain were also lower in dandelion leaf and root supplemented-group than in the control group, whereas glutathione S-transferase activity and gluthathione content were increased in dandelion supplemented-groups compared to the control group. With regard to the lipid peroxidation products, the malondialdehyde content of brain was lower in dandelion supplemented groups. Therefore, it could be suggested that powder and water extract of dandelion leaf or root are beneficial in preventing diabetic complication from lipid peroxidation and free radical in brain of diabetic rat brain.

• Korean Journal of Clinical Laboratory Science
• /
• v.46 no.1
• /
• pp.31-37
• /
• 2014

Metabolic syndrome such as, hypertension, diabetes, obesity, dyslipidemia etc are well known lifestyle diseases which threaten a health state. The purpose of this study is to evaluate antioxidant status and reactive oxygen species (ROS) in various stressful conditions. A group of persons (n=28) were enrolled in this study and stress status was evaluated using questionnaire of psychological well-being index (PWI-SF) and hematologic analysis of free oxygen radical defense (FORD), free oxygen radical test (FORT), lipid profiles and serum cortisol level. Analysis was done according to stress index, BMI status and overtime working. Blood samples from diabetics were used for control. Results are as in followings: Higher PWI-SF group showed higher FORT. Obese persons with BMI > $25kg/m^2$ showed statistically lower FORD (p<0.05) and higher FORT level (p<0.01). When compare with diabetics, an overweight group had similar levels in FORD and FORT while a normal body weight group showed quite different with diabetics in FORD (p<0.001). Higher ROS group has higher triglyceride, CRP and insulin levels but lower in FORD and HDL-cholesterol levels. Overtime working at night showed no meaningful result against our expectations. These results suggested that obesity showed most unfavorable correlations in an antioxidant status in various situations.

• Toxicological Research
• /
• v.17 no.4
• /
• pp.249-253
• /
• 2001

Fumonisin B1, a mycotoxin, is thought to induce esophageal cancer in humans and apoptosis in animal cells by inhibiting ceramide synthase. Dumonisin Bl may also generate reactive oxygen species directly or indirectly, leading to DNA damage and lipid peroxidation. In this study, a DNA fragmentation assay, dichlorofluorescein (DCF) analysis, and single cell gel electrophoresis (SCGE) were used to investigate the involvement of cellular free radicals, specifically hydrogen peroxide, in the DNA damaging activity of fumonisin B1. From an in vitro DNA fragmentation assay, E. coli DNA, damage by fumonisin Bl was increased by the addition of superxide dismutase (SOD) and decreased by catalase. SCGE and DCF analysis in vivo showed that the nuclear DNA damage and intracellular free radicals in cultured rat hepatocytes treated with fumonisin B1 were increased with the concentration of fumonisin Bl . DNA damage and free radical generation were inhibited by the addition of catalase. Fumonisin Bl , in the presence of SOD, produces hydrogen peroxide causing oxidative DNA damage and protein malfunction, leading to genotoxicity and cytotoxicity of the toxin.

• Journal of Food Hygiene and Safety
• /
• v.17 no.2
• /
• pp.106-116
• /
• 2002

The 70% ethanol extract of Alpinia officinarum and its major flavonoid, galangin showed strong antioxidative effect on the lipid peroxidation of ethyl linolate with Fenton's reagent and free radical scavenging effect to DPPH radical generation. However, they did not reveal any pro-oxidant effect on bleomycin-Fe(III) dependent DNA degradation. They also showed the protective effect against $H_2O$$_2$, KO$_2$ or UV-induced cytotoxicity in mammalian cells. They also showed the suppressive effect of DNA damage induced by $H_2O$$_2$ or KO$_2$ with dose-dependent manner in single cell gel electrophoresis(SCGE) assay. On the other hand, they have an anticlastogenic effect against adriamycin-induced micronucleated reticulocyte in peripheral blood of mice. These results suggest that the mechanism of inhibition by 70% ethanol extract of Alpinia officinarum and galangin against reactive oxygen species (ROS)-induced genotoxicity or cytotoxicity is due, at least partly, to their antioxidative and free radical scavenging properties without pro-oxidant effect. All these results indicate that 70% ethanol extract of Alpinia officinarum and galangin may be useful for protection against ROS-induced cytotoxicity and DNA damage.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2022.09a
• /
• pp.31-31
• /
• 2022

Plant-derived antioxidants are used as a healthy diet and are known to inhibit various human diseases. In this study, we investigated free radical scavenging and antioxidant activity of extracts from three plants (Ammannia multiflora, Ammannia coccinea and Salix gracilistyla) with the most DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity from 196 plant extracts inhabiting along Nakdong River in Republic of Korea. The three extracts also have strong total antioxidant activity. Moreover, the extracts inhibited hydrogen peroxide (H₂O₂)-induced reactive oxygen species production and depolarized mitochondrial membrane potential in RAW264.7 macrophages. In zebrafish larvae, 2',7'-dichlorodihydrofluorescein diacetate (DCFDA) fluorescent intensity, induced by H₂O₂, was markedly reduced by the extracts of A. multiflora, A. coccinea and S. gracilistyla. Meanwhile, the extracts were upregulated Nrf2 and HO-1 expression, and an HO-1 inhibitor reversed the extract-induced oxidative responses both in vivo and in vitro. The data suggest that the extracts of A. multiflora, A. coccinea, and S. gracilistyla exert potential free radical scavenging and antioxidant capacities both in vivo and in vitro by activating the Nrf2/HO-1 signaling pathway.

• Journal of Photoscience
• /
• v.9 no.2
• /
• pp.409-411
• /
• 2002

In order to prevent side reactions due to free radical formation occurring in the reactions of singlet oxygen generated in solution phse, it was required that singlet oxygen is generated in gas phase from an apparatus of a solid-gas system. We have accomplished to construct an apparatus generating singlet oxygen in solid-gas system, which is composed of a flexible optical fibre tube connected by a dye-sensitizer probe containing rose bengal dye on polymer or inorganic material. Through the optical fibre tube visible light from a laser and an oxygen stream are passed into the sensitizer probe where singlet oxygen is generated. The determination of singlet oxygen was carried out by two methods. One involves the detection of the luminescence of singlet oxygen at 1268 mn and the other involves the chemiluminescence reaction of a dihydroisobenzofuran with singlet oxygen emitting luminescence at 456 nm.

• Korean Journal of Pharmacognosy
• /
• v.44 no.3
• /
• pp.224-229
• /
• 2013

Bromotopsentin (BSM) is a bisindole alkaloid compound, which is recognized as a metabolite of the marine sponge Spongosorites sp. In this study, the antioxidant activity of BSM was investigated. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay, the trolox equivalent antioxidant capacity (TEAC) assay, the superoxide radical scavenging (NBT) assay, the lipid peroxidation and hydroxyl radical-induced DNA damage assays were carried out to evaluate the antioxidant activity of BSM. It was found that BSM had stronger scavenging activity on the stable free radical DPPH and superoxide radical than L-ascorbic acid with an $IC_{50}$ value of 62 and 64 ${\mu}M$, respectively. The TEAC value which indicated the total antioxidant capacity of BSM was about 0.8, which was also stronger than L-ascorbic acid. About 1.3 ${\mu}M$ of BSM induced 50% inhibition of lipid peroxidation. 60 nM of BSM exhibited a significant protective activity against DNA strand scission by hydroxyl radical on pBR322 DNA. Taken together, we suggest that BSM possesses strong antioxidant activity, and could be a valuable new addition to the list of anti-aging chemotherapeutic agents.

• Korean Journal of Pharmacognosy
• /
• v.37 no.4 s.147
• /
• pp.307-313
• /
• 2006

Reactive oxygen species (ROS) and formation of advanced glycation end products (AGEs) play an important role in the pathogenesis of diabetic nephropathy by hyperglycemia. To find natural agents improving diabetic nephropathy, 63 natural resources which used to the treatment of diabetes mellitus in a folk remedy were investigated with an in vitro system employing radical scavenging activity and inhibitory activity of AGEs formation. In results, the extracts of Aspalathus linearis, Rubus coreanus, Rosa rugosa, and Epimedium koreanum significantly inhibited the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical with $IC_{50}$ values less than $10{\mu}g/ml$. The extracts of Zea mays, Cucurbita moschata, Cudrania tricuspidata, and Aspalathus linearis effectively reduced the formation of AGEs compared with the positive control $N-acetyl-_L-cystenine$ (NAC) and aminoguanidine (AG). In addition, the extracts of Aspalathus linearis, Commelina communis, Cornus officinalis, and Lespodeza cuneata showed the all inhibitory activity against DPPH radical and AGEs formation. Also, these resources definitely showed the radical scavenging activity against peroxynitrite $(ONOO^-)$ and hydroxyl radical $({\cdot}OH)$ relating to high glucose-induced ROS production. Thus, these results suggest that some natural resources may regulate the initiation and progression of diabetic nephropathy through inhibition of ROS production and AGEs formation.

• The Korean Journal of Food And Nutrition
• /
• v.15 no.2
• /
• pp.151-157
• /
• 2002

This study was carried out to investigate functional activities of the free radical scavenging and germ of Glycin max. Merrill fur cytotoxicity toward P338 and L1210 cells derived from mouse. Effect of crude saponin were examined to oxygen radicals and their scavenger enzymes in liver fractions of Spragae-Dawley(SD) rats. Male rats were fed basic diets of control and experiment diets of 0.5∼1.0% crude saponin. There were no significant differences in hydroxy radical($.$OH) formation of liver mitochondria and microsomes in 1.0% group, while $.$OH formations were significantly decrease in 0.5% and 1.0% saponin compared with control group. Their oxygen radical(O$_2$$\^$$.$/) scavenging activities were significantly decrease in liver cytosol of 0.5% and 1.0% saponin group compared with control group. Soybean germ saponin was isolated purified by the method of HPLC to investigate the cytotoxicity of mouse cells by using the MTT assay. SA-1 saponin fraction of soybean germ showed to inhibit toward growth cell of P338 and L1210 cells and its showed less than 50% cytotoxicity These results suggest that the saponin may play a effective role in attenuating a oxygen radical formations and increasing a scavenger enzyme activities.