• Biomolecules & Therapeutics
• /
• v.19 no.3
• /
• pp.288-295
• /
• 2011

Amyloid beta ($A{\beta}$)-induced neurotoxicity is a major pathological mechanism of Alzheimer's disease (AD). In this study, we investigated the inhibitory effect of L-theanine, a component of green tea (Camellia sinensis) on $A{\beta}_{1-42}$-induced neurotoxicity and oxidative damages of macromolecules. L-theanine inhibited $A{\beta}_{1-42}$-induced generation of reactive oxygen species, and activation of extracellular signal-regulated kinase and p38 mitogenic activated protein kinase as well as the activity of nuclear factor kappa-B. L-theanine also signifi cantly reduced oxidative protein and lipid damage, and elevated glutathione level. Consistent with the reduced neurotoxic signals, L-theanine (10-50 ${\mu}g$/ml) concomitantly attenuated $A{\beta}_{1-42}$ (5 ${\mu}M$)-induced neurotoxicity in SK-N-MC and SK-N-SH human neuroblastoma cells. These data indicate that L-theanine on $A{\beta}$-induced neurotoxicity prevented oxidative damages of neuronal cells, and may be useful in the prevention and treatment of neurodegenerative disease like AD.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.53 no.1
• /
• pp.123-131
• /
• 2020

In this study, we investigated the protective effects of a Neutrase enzymatic hydrolysate derived from Korea pen shell Atrina pectinata (APN) against hydrogen peroxide (H₂O₂)-induced oxidative damage in hepatocytes. First, we confirmed that APN has antioxidant activities by scavenging 2,2-azino-bis (3-ethylbenzthiazoline)-6-sulfonic acid radical (ABTS⁺) and H₂O₂ and increasing oxygen radical absorbance capacity (ORAC) value. Also, the treatment of APN increased the cell viability by reducing the intracellular reactive oxygen species (ROS) production in H₂O₂-stimulated hepatocytes. In addition, APN decreased the sub-G₁ DNA contents and the apoptotic body formation increased by H₂O₂ stimulation. Moreover, APN modulated the protein expression of apoptosis related molecules (Bcl-2, Bax and p53) by suppressing the activation of nuclear factor NFkB and ERK/p38 signaling in H₂O₂-stimulated hepatocytes. Furthermore, APN led to the activation of Nrf2/HO-1signaling known as antioxidant systems. These results suggest APN protects hepatocytes against oxidative damages caused by H₂O₂ stimulation.

• Journal of Environmental Health Sciences
• /
• v.23 no.4
• /
• pp.9-15
• /
• 1997

This experiment was carried out to examine the roles of selenium in arsenic- and chromium-induced oxidative stress, which results in chromosomal damage, such as sister chromatid exchange (SCE) and chromosomal aberration (CA). For this purpose, the frequency of CA and SCE related to the level of 0xidative stress were analyzed. Selenium decreased the frequency of CA induced by As. In order to evaluate the effect of selenium on clastogenic factors, media from As- and Cr-treated cells were ultrafiltered and added again to cells in the presence or absence of selenium. Selenium decreased the frequency of SCE by As and Cr. This observation indicates the possibility of presence of clastogenic factor. In addition, the clastogenic factor would be involed in oxidative stress since selenium decreased the level of oxidative stress. Thus, it is suggested that selenium may play a role as an anti-clastogenic effector by preventing the oxidative stress, thereby decreasing the frequency of Asand Cr-induced chromosomal damage.

• Journal of Ginseng Research
• /
• v.43 no.2
• /
• pp.179-185
• /
• 2019

Background: Oxidative stress induces the production of reactive oxygen species (ROS), which play important causative roles in various pathological conditions. Black ginseng (BG), a type of steam-processed ginseng, has drawn significant attention due to its biological activity, and is more potent than white ginseng (WG) or red ginseng (RG). Methods: We evaluated the protective effects of BG extract (BGE) against oxidative stress-induced cellular damage, in comparison with WG extract (WGE) and RG extract (RGE) in a cell culture model. Ethanolic extracts of WG, RG, and BG were used to evaluate ginsenoside profiles, total polyphenols, flavonoid contents, and antioxidant activity. Using AML-12 cells treated with $H_2O_2$, the protective effects of WGE, RGE, and BGE on cellular redox status, DNA, protein, lipid damage, and apoptosis levels were investigated. Results: BGE exhibited significantly enhanced antioxidant potential, as well as total flavonoid and polyphenol contents. ATP levels were significantly higher in BGE-treated cells than in control; ROS generation and glutathione disulfide levels were lower but glutathione (GSH) and NADPH levels were higher in BGE-treated cells than in other groups. Pretreatment with BGE inhibited apoptosis and therefore protected cells from oxidative stress-induced cellular damage, probably through ROS scavenging. Conclusion: Collectively, our results demonstrate that BGE protects AML-12 cells from oxidative stress-induced cellular damages more effectively than WGE or RGE, through ROS scavenging, maintenance of redox status, and activation of the antioxidant defense system.

• The Journal of Korean Medicine
• /
• v.25 no.2
• /
• pp.173-183
• /
• 2004

Objectives : Oxidative stress can induce negative responses such as growth inhibition or cell death by necrosis or apoptosis due to the intensity of the oxidative stress, as well as positive responses such as cellular proliferation or activation. We examined the effect of Jihwangeumja on this process. Methods and Results : We analyzed the influence of oxidative stress and agents that modify its effect in human umbilical vein endothelial cell (HUVEC). Oxidative stress was induced by $B_2O_2$. With induced oxidative stress the results obtained indicate that it has a harmful effect over cell function and viability, and that this effect is dose and time dependent. When oxidative stress increased, Jihwangeumja reduced cell damage and had protective functions. $B_2O_2$, induced the apoptosis of HUVEC through the activation of intrinsic caspases pathway as well as mitochondrial dysfunction. A significant increase in cell survival was observed in culture cells with oxidative stress when they were treated with Jihwangeumja. Conclusions : These results suggest that Jihwangeumja may be potentially useful to treat HUVEC against oxidative damages mediated by modulation of caspase protease and mitochondrial dysfunction.

• Journal of Korean Medicine for Obesity Research
• /
• v.15 no.2
• /
• pp.55-67
• /
• 2015

Objectives: This study was to evaluate the effect of Palmijihwang-whan (PMJHW) aqueous extract in the regulation of hypothyroidism related reproductive organ damages in propylthiouracil (PTU)-induced rat model. Methods: PMJHW aqueous extract (yield=17.90%) were administered, once a day for 42 days from 2 weeks before start of PTU treatment as oral doses of 500, 250, and 125 mg/kg (body weight), and hypothyroidism was induced by daily subcutaneous treatment of PTU 10 mg/kg for 28 days. Results: PTU-induced hypothyroidism and related male reproductive organ damages-atrophic changes of testis, epididymis and prostate, were favorably and dose-dependently inhibited by treatment of PMJHW 500, 250, and 125 mg/kg. They also effectively regulated the PTU-induced abnormal antioxidant defense system changes in the testis. Although levothyroxine also favorably inhibited PTU-induced hypothyroidism, it deteriorated the hypothyroidism related male reproductive organ damages through testicular oxidative damages. The results suggest that oral administration of 125, 250, and 500 mg/kg of PMJHW has favorable effects on the hypothyroidism and related reproductive organ damages through augmentation of antioxidant defense system in the testis. Conclusions: This study suggest that PMJHW may be help to ameliorate the hypothyroidism and related organ damages in clinics.

• Proceedings of the International Microelectronics And Packaging Society Conference
• /
• 2003.11a
• /
• pp.22-26
• /
• 2003

Electrical conductivity of the oxidized MWNT(Multi walled nanotubes)/polymer composites were investigated with respect to various oxidative conditions of acid concentration, treatment temperature, and treatment time. To remove the impurities existing in MWNT-deposites, liquid-phase oxidation was performed using the $HNO_3/HSO_4$ mixtures. Secondary effects occurred by the oxidation of MWNTs such as the damages of MWNTs and the introduction of functionalities were analyzed through measuring FT-IR, TEM, and zeta potential, All the oxidized NWNTs were functionalized with carboxylic groups and the conditions of oxidation of the MWNTs could have a certain influence on the degree of functionalization, damages, and dispersion of the MWNT. The electrical properties of MWNT composites strongly depend on the oxidative conditions of MWNTs. The conductivity of the composites filled with the proper oxidized MWNT showed the highest percolation threshold.

• Biomolecules & Therapeutics
• /
• v.27 no.4
• /
• pp.381-385
• /
• 2019

We attempted to examine anti-inflammatory and anti-oxidant effects of 4'-O-${\beta}$-D-glucosyl-5-O-methylvisamminol (GOMV), the first epigenetic inhibitor of histone phosphorylation at Ser10. While GOMV did not affect the viability of murine macrophage RAW 264.7 cells, it significantly suppressed lipopolysaccharide (LPS)-induced generation of prostaglandin $E_2$ ($PGE_2$) and nitric oxide (NO) through transcriptional inhibition of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). GOMV also scavenged free radicals in vitro, increased NF-E2-related factor 2 (NRF2), and activated antioxidant response element (ARE), thereby resulting in the induction of phase II cytoprotective enzymes in human keratinocyte HaCaT cells. Finally, GOMV significantly protected HaCaT cells against 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced oxidative intracellular damages. Together, our results illustrate that GOMV possesses anti-inflammatory and anti-oxidant activity.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.20 no.1 s.32
• /
• pp.130-144
• /
• 2007

UV-irradiated skin shows acutely erythema, edema, pigmantation (sunbum) and chronically coarse wrinkling, roughness, dryness, laxity (photoaging). Jawoongo(紫雲膏, JW) is clinically useful external application and effective bum, sunburn, wound and symptom of dryness(燥症) in skin disease. In this experiment, we examined if JW could cure the UVB-mediated acute skin damages, inhibit UVB-mediated oxidative stress and inflammation of skin, and block the photoaging. In vivo test, we found that JW could effectively cure the UVB-mediated acute skin damages(erythema, edema, angiogenesis, hyperplasia, infiltration of lymphocytes) and inhibit expression of HSP70, CYP1A1 and p53. We also found that JW could repair destruction of collagen fiber and inhibit activation of MMP-9, and inhibit expression of $NF-{\kappa}B$ p65, iNOS, hyperplasia of keratynocyte. In vitro test, we found that JW could inhibit expression of IKK, iNOS mRNA, and production of NO. These findings shows that JW could cure the UVB-mediated acute skin damages, inhibit UVB-mediated oxidative stress and inflammation of skin, and block photoaging.

• Proceedings of the Korean Society of Toxicology Conference
• /
• 2001.05a
• /
• pp.151-151
• /
• 2001

According to the epidemiological studies in chromium workers, hexavalent chromium is associated with the risk of lung cancer. Reactive oxygen species produced by hexavalent chromium exposure may play an important role in the carcinogenesis process. We measured one kind of oxidative DNA damages, 8-hydroxydeoxyguanosine (8-OHdG) and its repair activities as an indicators of cellular oxidative stress in rat lungs by the repeated inhalation exposure to sodium chromate.(omitted)