• Journal of Nutrition and Health
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• 제43권5호
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• pp.443-452
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• 2010

Elevated plasma concentration of total homocysteine (ptHcy) is known as an independent risk factor of cardiovascular disease (CVD) and oxidative stress is also commonly implicated in CVD. An association between ptHcy and oxidative stress has recently been suggested. The study objective is to examine the relationship between ptHcy and oxidative stress markers in 103 healthy college students (62 males and 41 females). Plasma levels of ptHcy, oxidative stress markers (conjugated diene, erythrocyte catalase, TRAP, lymphocyte DNA damage), antioxidant vitamins ($\alpha$-tocopherol, $\gamma$-tocopherol, carotenoids), and lipid parameters (total cholesterol, triglyceride, HDL cholesterol) were determined. The results show that the concentration of ptHcy was significantly higher in male subjects ($22.17\;{\pm}\;2.14\;{\mu}mole/L$) than in female subjects ($12.28\;{\pm}\;0.45\;{\mu}mole/L$). There was a negative association between ptHcy and plasma ${\beta}$-carotene in male subjects (p $lt; 0.05), but no correlation between ptHcy and other plasma antioxidant vitamin levels in either gender. However, there were the negative correlations between ptHcy and plasma ${\alpha}$-carotene or ${\beta}$-carotene, and a positive correlation between ptHcy and lymphocyte DNA damage. A significantly low level of ${\alpha}$-carotene or ${\beta}$-carotene was found in male subjects with elevated ptHcy (${\geq}\;15\;{\mu}mol/L$), as compared to those with lower plasma homocysteine. These study results confirmed the views on the association between plasma homocysteine and oxidative stress markers in humans and support the hypothesis that homocysteine promotes the oxidative environment by counteracting the antioxidant defense mechanism.

• 한국수산과학회지
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• 제38권5호
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• pp.304-308
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• 2005

The effects of diethylhexyl phthalate (DEHP) on various oxidative stress responses in liver, kidney and gill tissues of freshwater bagrid catfish Pseudobagrus fulvidraco were investigated under laboratory conditions. Bagrid catfish were intraperitoneally injected with sunflower seed oil containing nominal concentrations of 0, 300 or 900mg DEHP per kilogram of body weight for 3 days and the effects after last injection were assessed in liver, kidney and gill tissues of the exposed organisms. The oxidative stress responses of fish were evaluated by analyzing the level of glutathione (GSH), as well as the activities of antioxidant enzymes such as glutathione S-transferase (GST), glutathione peroxidase (GPx) and glutathione reductase (GR). After exposure to the DEHP, there were significant decrease in GR, GPx activity and GSH content in liver of fish exposed to 900 mg DEHP per kilogram of body weight compared to the control group. Compared with the control group, significant decreases in renal GPx and GR activity were observed in the DEHP treatment groups (900 mg $kg^{-1}$ bw). However, no significant difference was observed in any oxidative stress responses in gills between the DEHP-treated and the untreated group of fish. The findings of the present investigation show that DEHP induce oxidative stress and the liver was the most affected organ followed by the kidney and gills. Furthermore, the changes of GPx and GR activities may be important indicators of oxidative stress responses but additional study is required to confirm the oxidative stress of DEHP.

• 한국초지조사료학회지
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• 제42권4호
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• pp.222-228
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• 2022

This study was conducted to investigate the effect of waterlogging stress on the physiological response and growth characteristics of the five Italian ryegrass varieties. For all varieties, the germination rate of seed decreased by 10-15% as the waterlogging period increased, but the waterlogging stress treatment after the early seedling stage increased the growth of shoot and root length. Photosynthetic activity (Fv/Fm) according to waterlogging stress treatment decreased in all vareity, and Florida 80 showed the least decrease with 1.5%. Waterlogging stress treatment was found to reduce the accumulation of reactive oxygen species (malondialdehyde, MDA) and the activities of antioxidant enzymes. These results suggest that other mechanisms may be involved in the defense mechanism of Italian ryegrass against waterlogging stress, such as promoting root growth to escape from waterlogging stress, in addition to the antioxidant enzyme system.

• 한국해양생명과학회지
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• 제9권1호
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• pp.33-40
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• 2024

To understand the detrimental effects of triclosan on Java medaka (Oryzias javanicus) embryos, fertilized embryos were exposed to different concentrations (1, 10, 50, 100, 200, 400, 600, 800, and 1,000 ㎍ l^-1) of triclosan until hatching. Then, we examined the survival rate and developmental parameters as well as alterations in antioxidant constituents and DNA damage markers. The results showed dose-dependent mortality, hatching delays, and developmental abnormalities in the embryos. Additionally, there were significant increases in oxidative stress parameters and antioxidant responses, along with elevated DNA damage. These findings suggest that sublethal concentrations of triclosan induce toxic effects through oxidative stress on Java medaka embryos, as evidenced by changes in in vivo parameters and biochemical constituents.

• Journal of Nutrition and Health
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• 제44권6호
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• pp.488-497
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• 2011

Oxygen is necessary to sustain life, yet cellular oxygen metabolism creates destructive elements called free radicals. Free radicals are chemically unbalanced and carrying free electrons that can damage molecules, potentially damaging the cell itself. For this reason, many antioxidant products, including supplements and functional foods, are being developed. In particular, natural products are rich sources of pharmacologically active compounds. The purpose of this study was to investigate the antioxidant effects of target biomaterials in Korean traditional spices such as diallyl sulfide (DAS), capsaicin (CAP), and gingerol (GGR), and to investigate the response of the antioxidant defense system to oxidative stress by hydrogen peroxide ($H_2O_2$) compared to sulforaphane (SFN) in HepG2 cells. After the analysis of the cell viability using Cell Counting kit-8 (CCK-8) assay, we determined that the optimum levels were $200{\mu}M$ DAS, $25{\mu}M$ CAP, $50{\mu}M$ GGR, and $12.5{\mu}M$ SFN. Antioxidant enzymes were measured and protein expression was detected by Western blotting. All treatments showed a significant decrease in antioxidant enzyme activity such as superoxide dismutase, catalse, and glutathione peroxidase in HepG2 cells. Additionally, DAS, CAP, GGR and SFN increased the antioxidant system-related transcription factor Nrf2 which was found to be regulated by the activation of MAPK-JNK in this study. In conclusion, these results indicate the protective effects of DAS CAP, GGR, and SFN against $H_2O_2$-induced oxidative stress.

• Asian Pacific Journal of Cancer Prevention
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• 제15권2호
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• pp.561-568
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• 2014

Background: The skin is the largest body organ that regulates excretion of metabolic waste products, temperature, and plays an important role in body protection against environmental physical and chemical, as well as biological factors. These include agents that may act as oxidants or catalysts of reactions producing reactive oxygen species (ROS), reactive nitrogen species (RNS), and other oxidants in skin cells. An increased amount of the oxidants, exceeding the antioxidant defense system capacity is called oxidative stress, leading to chronic inflammation, which, in turn, can cause collagen fragmentation and disorganization of collagen fibers and skin cell functions, and thus contribute to skin diseases including cancer. Moreover, research suggests that oxidative stress participates in all stages of carcinogenesis. We report here a summary of the present state of knowledge on the role of oxidative stress in pathogenesis of dermatologic diseases, defensive systems against ROS/RNS, and discuss how physical activity may modulate skin diseases through effects on oxidative stress. The data show duality of physical activity actions: regular moderate activity protects against ROS/RNS damage, and endurance exercise with a lack of training mediates oxidative stress. These findings indicate that the redox balance should be considered in the development of new antioxidant strategies linked to the prevention and therapy of skin diseases.

• Asian-Australasian Journal of Animal Sciences
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• 제23권11호
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• pp.1482-1489
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• 2010

This study aimed to determine the effects of vitamin C and propolis-supplemented feeds on some blood parameters, lipid peroxidation, and activities of some antioxidant enzymes in broilers exposed to oxidative stress. 360 three-day-old broiler chicks (Ross 308) were randomly divided into four treatment groups each containing 90 animals, including six replicate groups for each treatment. The experimental groups were designated for a 3-42 days period as follows: no supplement to basal ration (Control-Group I); supplement of 500 ppm vitamin C and 200 ppm lead (as lead acetate) to basal ration (Group II); supplement of 1 g/kg propolis and 200 ppm lead (as lead acetate) to basal ration (Group III); and supplement of 200 ppm lead (as lead acetate) to basal ration (Group IV). The highest TG level (86.83 mg/dl) was observed in the lead supplemented group; however, the lowest aspartate aminotransferase (SGOT) level (90.71 IU/L) was observed in the control group (p<0.05). The addition of lead increased the plasma malondialdehyde (MDA) level (p<0.01) compared to other treatments. However, the addition of vitamin C and propolis decreased the plasma MDA level close to control levels. The highest erythrocyte superoxide dismutase (SOD) activity was observed in the lead addition group (p<0.01) while no significant differences were observed for SOD activities of the control, vitamin C +lead, and propolis+lead groups. The plasma reduced glutathione (GSH) activity of the control ($2.30{\mu}mol$/ml) was significantly lower than the lead administered group ($6.20{\mu}mol$/ml) (p<0.01); while this parameter was determined to be similar to other groups. No significant differences were observed between groups for liver GSH activity, but heart GSH activity of the control was significantly higher in comparison to other treatments (p<0.05). To obtain similar antioxidant effects, it is recommend that using propolis (1 g/kg) and vitamin C (500 mg/kg) supplementation in broiler diets may overcome the adverse effects of oxidative stress originating from dietary lead.

• 한국환경보건학회지
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• 제30권3호
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• pp.230-238
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• 2004

The adverse health effects of a number of environment pollutions are related to the formation of free radicals. Induction of antioxidant defensive system in the response to an oxidative attack is an essential element of the cell to survive. CYP2E1 is easily induced by organic solvents and induces continuous formation of reactive oxygen species (ROS). ${\gamma}$-Glutamyltranspeptidase (${\gamma}$GT) plays an important role in glutathione metabolism and xenobiotic detoxification. To evaluate the characteristic of oxidative stress which induces GGT expression and to understand human antioxidant defensive response against oxidative stress induced by CYP2E1, we studied regulation of ${\gamma}$GT enzyme expression in response to various oxidative stresses in human HepG2 cells. The ${\gamma}$GT activity was not modified after exposure of acute oxidative stress inducing agents (ferric nitrilotriacetate, cumene hydroperoxide, ADP-Fe, O-tetradecanoylphorbol-13-acetate, tumor necrosis factor-alpha). To induce continuous exposure of cells to ROS, HepG2 cells were transfected by human CYP2E1 gene transiently. The CYP2E1 activity was verified with chlorzoxazone hydroxylation. Transfection of CYP2E1 showed continuous 60% increase in intracellular ROS and 240 % increase in microsomal ROS. CYP2E1 overexpressing cells showed increased ${\gamma}$GT activity (2.5-fold). The observed enhancement of ${\gamma}$GT activity correlated with a significant increase of ${\gamma}$GT mRNA (2.1-fold). Treatment with antioxidant strongly prevented the increase in ${\gamma}$GT activity. The CYP2E1 overexpression did not modify toxicity index and increased glutathione levels. These results show that continuous exposure of cells to ROS produced by CYP2E1 up-regulates ${\gamma}$GT; This may be one of the adaptive antioxidant responses of cells to oxidative insult. Present study also suggests that the induction of ${\gamma}$GT could be used as a marker of oxidative stress induced by exposure to organic solvents.

• Molecules and Cells
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• 제28권5호
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• pp.479-487
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• 2009

Glutathione reductase (GR) is an enzyme that recycles a key cellular antioxidant molecule glutathione (GSH) from its oxidized form (GSSG) thus maintaining cellular redox homeostasis. A recombinant plasmid to overexpress a GR of Brassica rapa subsp. pekinensis (BrGR) in E. coli BL21 (DE3) was constructed using an expression vector pKM260. Expression of the introduced gene was confirmed by semi-quantitative RT-PCR, immunoblotting and enzyme assays. Purification of the BrGR protein was performed by IMAC method and indicated that the BrGR was a dimmer. The BrGR required NADPH as a cofactor and specific activity was approximately 458 U. The BrGR-expressing E. coli cells showed increased GR activity and tolerance to $H_2O_2$, menadione, and heavy metal ($CdCl_2$, $ZnCl_2$ and $AlCl_2$)-mediated growth inhibition. The ectopic expression of BrGR provoked the co-regulation of a variety of antioxidant enzymes including catalase, superoxide dismutase, glutathione peroxidase, and glucose-6-phosphate dehydrogenase. Consequently, the transformed cells showed decreased hydroperoxide levels when exposed to stressful conditions. A proteomic analysis demonstrated the higher level of induction of proteins involved in glycolysis, detoxification/oxidative stress response, protein folding, transport/binding proteins, cell envelope/porins, and protein translation and modification when exposed to $H_2O_2$ stress. Taken together, these results indicate that the plant GR protein is functional in a cooperative way in the E. coli system to protect cells against oxidative stress.

• Journal of Nutrition and Health
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• 제55권4호
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• pp.450-461
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• 2022

Purpose: DNA damage and repair responses are induced by metabolic diseases and environmental stress. The balance of DNA repair response and the antioxidant system play a role in modulating the entire body's health. This study uses a high-fat and high-calorie (HFC) drink to examine the new roles of a plant-based multivitamin/mineral supplement with phytonutrients (PMP) for regulating the antioxidant system and cellular DNA repair signaling in the body resulting from metabolic stress. Methods: In a double-blind, randomized, parallel-arm, and placebo-controlled trial, healthy adults received a capsule containing either a PMP supplement (n = 12) or a placebo control (n = 12) for 8 weeks. Fasting blood samples were collected at 0, 1, and 3 hours after consuming a HFC drink (900 kcal). The blood samples were analyzed for the following oxidative stress makers: areas under the curve reactive oxygen species (ROS) levels, plasma malondialdehyde (MDA), erythrocytes MDA, urinary MDA, oxidized low-density lipoprotein, and the glutathione:oxidized glutathione ratio at the time points. We further examined the related protein levels of DNA repair signaling (pCHK1 (Serine 345), p-P53 (Serine 15), and 𝛄H2AX expression) in the plasma of subjects to evaluate the time-dependent effects of a HFC drink. Results: In a previous study, we showed that PMP supplementation for eight weeks reduces the ROS and endogenous DNA damage in human blood plasma. Results of the current study further show that PMP supplementation is significantly correlated with antioxidant defense. Compared to the placebo samples, the blood plasma obtained after PMP supplementation showed enhanced DNA damage response genes such as pCHK1(Serine 345) (a transducer of DNA response) and 𝛄H2AX (a hallmark of DNA damage) during the 8 weeks trial on metabolic challenges. Conclusion: Our results indicate that PMP supplementation for 8 weeks enhances the antioxidant system against oxidative stress and prevents DNA damage signaling in humans.