• Journal of Photoscience
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• v.9 no.2
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• pp.146-149
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• 2002

Oxidative stress evoked hy Ultraviolet (UV) exposure has been suggested to be involved in UV-induced skin carcinogenesis. In this study, the role of oxidative stress in UV-carcinogenesis was evaluated by applying N-Acetylcysteine (NAC) in animal model of hairless-mouse. NAC is known to be a precursor of glutathione, which was converted to glutathione in cytoplasm, acting as an intracellular free radical scavenger. The glutathione levels in hairless mouse skin after one time application of NAC increased significantly. With and without the pre-treatment of NAC, hairless-mice were exposed to UVB three times a week, at total dose 274.4 kJ in 80 times, and the timing of tumor-development, incidence of skin tumor and the histopathology of tumors were observed. 8-hydroxy-2'-deoxyguanosine (8-0HdG), a typical form of oxidative damage in DNA has been also investigated in the course of experiment. The decrease of 8-0HdG formation of UVB- exposed skin compared to controls was observed in the early stage of experiment in the NAC-treated mice. In addition, initial tumor development delayed significantly in NAC-treated group. Finally the number of the tumor developed in the NAC-treated mice was fewer though not significant. These results suggest that antioxidants may have inhibitory effect in the initial step of UVB-induced carcinogenesis of hairless mice.

• Biomolecules & Therapeutics
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• v.18 no.2
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• pp.145-151
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• 2010

Oxygen supply into inside solid tumor is often diminished, which is called hypoxia. Many gene transcriptions were activated by hypoxia-inducible factor (HIF)-$1{\alpha}$. Here, we investigated the effect of hypoxia on paclitaxel-resistance induction in HeLa cervical tumor cells. When HeLa cells were incubated under hypoxia condition, HIF-$1{\alpha}$ level was increased. In contrast, paclitaxel-mediated tumor cell death was reduced by the incubation under hypoxia condition. Paclitaxel-mediated tumor cell death was also inhibited by treatment with DMOG, chemical HIF-$1{\alpha}$ stabilizer, in a dose-dependent manner. A significant increase in intracellular ROS level was detected by the incubation under hypoxia condition. A basal level of cell density was increased in response to 10 nM $H_2O_2$. HIF-$1{\alpha}$ level was increased by treatment with various concentration of $H_2O_2$. The increased level of HIF-$1{\alpha}$ by hypoxia was reduced by the treatment with N-acetylcysteine (NAC), a well-known ROS scavenger. Paclitaxel-mediated tumor cell death was increased by treatment with NAC. Taken together, these findings demonstrate that hypoxia could play a role in paclitaxel-resistance induction through ROS-mediated HIF-$1{\alpha}$ stabilization. These results suggest that hypoxia-induced ROS could, in part, control tumor cell death through an increase in HIF-$1{\alpha}$ level.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.3
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• pp.774-782
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• 2004

The water extract of Dancheonhwan (DCH) has been used to treat ischemic brain and heart damage in oriental medicine. However, little is known about the mechanism by which the water extract of DCH rescues cells from ischemic damage. Therefore, this study was designed to investigate the protective mechanisms of DCH on the H₂O₂-induced toxicity in H9c2 cardiomyoblast cells. Treatment of H₂O₂ markedly decreased the viability of H9c2 cardiomyoblast in a dose-dependent and time-dependent manner. The nature of H₂O₂-induced toxicity of H9c2 cells resulted from apoptotic death confirmed with genomic DNA fragmentation. DCH increased the viability of H₂O₂-treated H9c2 cells by about 23%, and partially suppressed the genomic DNA fragmentation and PARP cleavage. H₂O₂ also activated caspase-3 protease and -9 protease, but not both caspase-6 protease and -8 protease. H₂O₂ induced the mitochondria dysfunction, including mitochondria membrane permeability transition (MPT) and cytosolic release of cytochrome c from mitochondria, which was prevented in part by pretreatment of DCH. N-acetylcystein (NAC), a free-radical scavenger, alone increased the viability of H₂O₂-treated H9c2 cells in a dose-dependent manner. Furthermore, the combination of NAC with DCH significantly increased the viability of the H₂O₂-treated H9c2 cells in a dose-dependent manner. These data indicate that DCH has the protective effect on ROS-induced apoptosis of cadiomyoblast H9c2 cells.

• The Journal of Korean Medicine
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• v.25 no.4
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• pp.61-78
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• 2004

Objective : This study was undertaken to determine whether Gamibaegi-eum (BGU) in vitro and in vivo exerts a beneficial effect against cell injury induced by reactive oxygen species (ROS) in the human intestine. Methods : Effects of BGU in vitro on cell injury were examined using Caco-2 cells, cultured human intestinal cell line. Exposure of cells to H₂O₂ induced increases in the loss of cell viability in a time and dose-dependent fashion. Results : BGU prevented H₂O₂-induced cell death and its effect was dose-dependent over a concentration range of 0.05­1%. H₂O₂-induced cell death was prevented by catalase, the hydrogen peroxide scavenger enzyme, and deferoxamine, the iron chelator. However, the potent antioxidant DPPD did not affect H₂O₂-induced cell death. H₂O₂ increased lipid peroxidation, which was inhibited by BGU and DPPD. H₂O₂ caused DNA damage in a dose-dependent manner, which was prevented by BGU, catalase, and deferoxamine, but not DPPD. BGU restored ATP depletion induced by H₂O₂. BGU inhibited generation of superoxide and H₂O₂ and scavenged directly H₂O₂. Oral administration of mepirizole in vivo at a dose of 200mg/kg resulted in ulcer lesions in the stomach and the proximal duodenum. Pretreatment of BGU(0.1%/kg, orally) and catalase (800Units/kg, i.v.) significantly decreased the size of ulcers. Mepirizole increased lipid peroxidation in the mucosa of the duodenum, suggesting an involvement of ROS. Pretreatment of BGU and catalase significantly inhibited lipid peroxidation induced by mepirizole. Morphological studies showed that mepirizole treatment causes duodenal injury and its effect is prevented by BGU. Conclusion : These results indicate that BGU exerts a protective effect against cell injury in vitro and in vivo through antioxidant action. The present study suggests that BGU may playa therapeutic role in the treatment of human gastrointestinal diseases mediated by ROS.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.2
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• pp.199-205
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• 2012

An extract of Alnus japonica (Betulaceae) cortex has been traditionally used for purifying blood, and curing feces containing blood, enteritis, diarrhea, alcoholism and cut wounds. In the present study, we demonstrated that the ethanol extract of Alnus japonica (EAJ) exhibited significantly cytotoxicity in human colon adenocarcinoma HT-29 cells. The results showed that the induction of apoptosis in HT-29 cells by EAJ was characterized by chromatin condensation and activation of caspase-3. EAJ-induced activation of caspase-9 and -3 caused the cleavage of poly ADP-ribose polymerase (PARP) and the release of cytochrome c. The expressions of Bcl-2 and Bid were reduced by EAJ in HT-29 cells, whereas pro-apoptotic protein Bak was increased in the cells. EAJ-induced, dose-dependent induction of apoptosis was accompanied by sustained phosphorylation of MAP kinases (JNK and p38 MAPK), ASK1, and p53. NAC administration, a scavenger of ROS, reversed EAJ-induced cell death. In conclusion, these results indicated that EAJ can cause apoptosis through a ROS-mitochondria-caspases-dependent pathway in human HT-29 cells.

• Korean Chemical Engineering Research
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• v.50 no.4
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• pp.604-609
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• 2012

Properties of fucoidan used for functional cosmetic ingredients and the effect of fucoidan molecular weight on the cosmetic functions were studied. Fucoidan was extracted from Undaria pinnatifida sporophylls and molecular weight (35~160 kDa) of fucoidan was controlled by contact glow discharge electrolysis (CGDE). To test possibility of fucoidan as a cosmetics material, tyrosinase inhibition property, water-holding property, elastase activity inhibition property and DPPH free radical scavenging property were measured. Water-holding property of fucoidan was higher than that of hyaruronic acid, which is known as the one of the best water-holding material. The water-holding strength of fucoidan slightly increase as molecular weight of fucoidan decrease. Elastase activity inhibition (anti wrinkle effect) of fucoidan was higher than that of adenosine using standard material for anti wrinkle test. Optimum molecular weight of fucoidan to obtain highest tyrosin inhibition effect, elastase inhibition effect and radical scavenger effect is 100 kDa.

• Journal of Acupuncture Research
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• v.31 no.2
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• pp.87-98
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• 2014

Objectives : We investigated whether snake venom toxin(SVT) from Vipera lebetina turanica sensitizes HT29 human epithelial colorectal cancer cells to tumor necrosis factor(TNF)-related apoptosis-inducing ligand(TRAIL) induced apoptosis in cancer cells. Methods : Cell viability assay was used to assess the inhibitory effect of TRAIL on cell growth of HT29 human colorectal cancer cells. And 6-diamidino-2-phenylindole(DAPI), terminal deoxynucleotidyl transferase mediated dUTP nick end labeling assay(TUNEL) staining assay were used to evaluate cell-apoptosis. Western blot analysis were conducted to observe apoptosis related proteins and death receptor. To assess whether the synergized inhibitory effect of SVT and TRAIL on reactive oxygen species(ROS) generation was reversed by strong anti-oxidative agent. Results : SVT with TRAIL inhibited HT29 cell growth different from TRAIL alone. Consistent with cell growth inhibition, the expression of TRAIL receptors; Expression of death receptor(DR)4 and DR5 was significantly increased and intrinsic pro-apoptotic cleaved caspase-3, -9 was subsequently increased together with increase of Bax/Bcl-2 ratio and extrinsic pro-apototic caspase-8 was also activated. In addition, the expression of anti-apoptotic survival proteins, a marker of TRAIL resistance(eg, cFLIP, survivin, X-linked inhibitor of apoptosis protein(XIAP) and Bcl-2) was suppressed by the combination treatment of SVT and TRAIL. Pretreatment with the ROS scavenger N-acetylcysteine abolished the SVT and TRAIL-induced upregulation of DR4 and DR5 expression and expression of the intrinsic pro-apoptotic caspase-3 and-9. Conclusion : The collective results suggest that SVT facilitates TRAIL-induced apoptosis in $HT_{29}$ human epithelial colorectal cancer cells through up-regulation of the TRAIL receptors; DR4 and DR5 and consecutive induction of bilateral apoptosis via regulating apoptosis related proteins.

• Bulletin of the Korean Chemical Society
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• v.32 no.spc8
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• pp.3039-3044
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• 2011

This study suggests the prediction model for the concentration variation of $NO_2{^-}$ and $NO_3{^-}$ along with the rate constants of all reactions during ozonation under UV radiation ($O_3$/UV process). While $NO_2{^-}$ was completely converted into $NO_3{^-}$ during the $O_3$-only process, the production of $NO_2$ radical or $N_2O_4$ was expected in the $O_3$/UV process. In addition, the quenching of OH radicals, by $NO_2$ radical in the $O_3$/UV process, resulted in regeneration of $NO_2{^-}$. However, the regeneration of $NO_2{^-}$ was not observed in the $O_3$/UV process in the presence of $C_6H_6$ where the concentrations of $NO_2{^-}$ and $NO_3{^-}$ were significantly reduced compared to in the process without $C_6H_6$. The pseudo-first order rate constants of all species were calculated with and without the presence of $C_6H_6$ to predict the variation of concentrations of all species during the $O_3$/UV process. It was suggested that $NO_2{^-}$ and $NO_3{^-}$ in the $O_3$/UV process can be more effectively removed from an aqueous system with an OH radical scavenger such as $C_6H_6$.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5843-5848
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• 2012

Aim: Developing antitumor drugs from natural products is receiving increasing interest worldwide due to limitations and side effects of therapy strategies for the second leading cause of disease related mortality, cancer. Methods: The antiproliferative activity of a methanolic extract from the aerial parts of Marrubium persicum extract was assessed with the MCF-7 breast cancer cell line using the MTT test for cell viability and cytotoxicity indices. In addition, antioxidant properties of the extract were evaluated by measuring its ability to scavenge free DPPH radicals. Moreover, the total phenolic and flavonoid content of the extract was determined based on Folin-Ciocalteu and colorimetric aluminum chloride methods. Results: The findings of the study for the antiproliferative activity of the methanolic extract of M. persicum showed that growth of MCF-7 cells was inhibited by the extract in a dose and time dependent manner, where a gradual increase of cytotoxicity effect has been achieved setting out on 200 ${\mu}g/mL$ concentration of the plant extract. The antioxidant assay revealed that the extract was a strong scavenger of DPPH radicals with an $RC_{50}$ value of 52 ${\mu}g/mL$. The total phenolic and flavonoids content of the plant extract was 409.3 mg gallic acid equivalent and 168.9 mg quercetin equivalent per 100g of dry plant material. Conclusion: Overall, M. persicum possesses potential antiproliferative and antioxidant activities on the malignant MCF-7 cell line that could be attributed to the high content of phenolics and flavonoids, and therefore warrants further exploration.

• Journal of Korean Society on Water Environment
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• v.35 no.6
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• pp.459-469
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• 2019

The ozonation of sulfamethoxazole (SMX) was performed at 20℃ using a pilot scale countercurrent bubble column reactor. Ozonation systems were combined with UV irradiation and TiO₂ addition. As the oxidation reaction proceeded in each treatment system, the pH of the sample decreased and in the O₃/UV/TiO₂ system, the pH change was the largest from 4.54 to 2.02. Under these experimental conditions, the scavenger impact of carbonate is negligible. The highest COD and TOC removal rate was observed in the O₃/UV/TiO₂ system due to the UV irradiation and the photocatalytic effect of TiO₂. Also, the highest mineralization ratio(ε) value is 0.2 in the O₃/UV/TiO₂ system, which means theoxidation capacity of the systems. The highest SMX degradation rate constants calculated by COD and TOC values (COD and TOC) were 2.15 × 10^-4 sec^-1 and 1.00 × 10^-4 sec^-1 in the O₃/UV/TiO₂ system, respectively. The activation energy (E_a) of ozone treatment follows the Arrhenius law. It was calculated based on _COD and _TOC. Each activation energy decreased in order of single O₃> O₃/TiO₂> O₃/UV > O₃/UV/TiO₂ system. The result showed that ΔH^≠ is more effective than ΔS^≠ in each SMX ozontaionsystem, that is characteristic of the common oxidation reaction.