• Food Science and Biotechnology
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• v.17 no.2
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• pp.343-348
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• 2008

In this study, antioxidant activity of methanol extract of Glycyrrhiza uralensis Fisch (GUE) against $H_2O_2$-induced DNA damage in human leucocytcs and cell death in PC12 cells was determined. The effect of GUE on $H_2O_2$-induced DNA damage in human leucocytcs was evaluated by the comet assay, where GUE ($1-50\;{\mu}g/mL$) was a dose dependent inhibitor of DNA damage induced by $H_2O_2$. The protective effect of GUE against $H_2O_2$-induced damage on PC12 cells was investigated by MTT reduction assay and lactate dehydrogenase release assay. A marked reduction in cell survival induced by $H_2O_2$ was significantly prevented by $1-50\;{\mu}g/mL$ of GUE. The enzyme activity of caspase-3 was elevated in $H_2O_2$-treated PC12 cells, while preincubation with GUE for 30 min inhibited $H_2O_2$-induced caspase-3 activation in a dose-dependent manner. In conclusion, GUE ameliorates $H_2O_2$-induced DNA damage in human leucocytes and has neuroprotective effect by preventing cell death in PC12 cell, suggesting that GU may be a potential candidate for novel therapeutic agents for neuronal diseases associated with oxidative stress.

• The Journal of Korean Medicine
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• v.25 no.2
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• pp.1-8
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• 2004

Objectives : This study was performed to investigate the effects of Smilacis GlabraeRhizoma on antioxidation and antimicrobial activity. Methods : In this study, we investigated the effects of peroxide radicals on hydrogen donating activity and linoleic acid, and the MDA contents on the hepatic lipids of rats, via methanol extractions and subfractions of Smilacis Glabrae Rhizoma. Results : 1. Hydrogen donating activity was very great for the radical scavenging effects, depending on the additional concentration at the fraction level of chloroform and ethyl acetate. 2. The peroxide radicals in linoleic acid were lower depending on the additional concentration, at the fraction level of ethyl acetate, than the controls. We concluded that both had significant anti-oxidation effects. 3. MDA contents of the hepatic lipid had also inhibition effects on lipid radicals, in proportion to the concentration of n-hexane, chloroform, and ethyl acetate fraction level. 4. After extracting Smilads Glabrae Rhizoma with 80% methanol, we experimented with the extracts the antibiosis each concentration, for 5 bacilli, Bacilus subtilis, staphylococcus aureus, Escherichia coli, Salmonela typhimurium, and Alcaligenes faecalis. While the effects showed differentiations by concentration, they had usually the significant inhibition effect for the multiplication at 37.5~75ug/ml. To identify the effective constituents, we identified the antibiosis of the fractions assaying cyclically hexane, chloroform, ethyl acetate, and butanol. The result showed that antimicrobial activation of both Gram-positive and Gram-negative bacillus except for E. coli was measured highest at the fraction level of BuOH and water. Conclusions : This result suggest that the extractions of Smilacis Glabrae Rhizoma, at ethyl acetate fraction, had significant anti-oxidation effects and at BuOH and water fraction had relatively strong antimicrobial activity against Bacilus subtilis, staphylococcus aureus, Salmonela typhimurium, and Alcaligenes faecalis.

• IMMUNE NETWORK
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• v.3 no.4
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• pp.276-280
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• 2003

Background: Peroxidases (Prx) of the peroxiredoxin family reduce hydrogen peroxide and alkyl hydroperoxides to water and alcohol respectively. Hydrogen peroxide is implicated as an intracellular messenger in various cellular responses such as proliferation and differentiation. And Prx I activity is regulated by Cdc-2 mediated phosphorylation. This work was undertaken to investigate the proliferation role of peroxiredoxin III as a member of Prx family in Prx III overexpressed HeLa cell line. Methods: To provide further evidence of proliferation, we selected Prx III stably expressed HeLa Tet-off cell lines. Cell proliferation was examined by using proliferation reagent WST-1 in the presence or absence of doxycycline. Prx III, 2-cys Prx enzymes exist as homodimer. The activation of Prx III heterodimer with induced and endogenous Prx III was examined by immunoprecipitation. Results: Immunoprecipitation analysis of the induced and endogenous Prx III with anti-myc showed that the induced wild type (WT) and dominant negative (DN) Prx III from HeLa Prx III Tet-off stable cell heterodimerized with endogenous Prx III each other. And the expression level of induced Prx III was examined after addition of doxycycline. By 72 hr, the expression level of induced Prx III was diminished gradually and the half-life of the induced wild type Prx III was approximately 17 hr. The proliferation experiment demonstrated that the relative proliferation value of induced and endogenous WT Prx III stable cell has no changes but the DN Prx III induced HeLa Tet-off stable cells were lower than endogenous Prx III. Conclusion: In conclusion, the HeLa dominant negative Prx III Tet-off stable cells were decreased the proliferation.

• Journal of Korean Medicine for Obesity Research
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• v.15 no.2
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• pp.93-103
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• 2015

Objectives: It was investigated the cytoprotective efficacies of isorhamnetin, a flavonoid originally derived from Hippophae rhamnoides L., against oxidative stress-induced apoptosis in C2C12 myoblasts. Methods: The effects of isorhamnetin on cell growth, apoptosis and reactive oxygen species (ROS) generation were evaluated by trypan blue dye exclusion assay, 4',6-diamidino-2-phenylindole staining and flow cytometry. The levels of apoptosis-regulatory and nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway-related proteins, and caspase activities (caspase-3 and -9) were determined by Western blot analysis and colorimetric assay, respectively. Results: Our results revealed that treatment with isorhamnetin prior to hydrogen peroxide ($H_2O_2$) exposure significantly increased the C2C12 cell viability and, indicating that the exposure of C2C12 cells to isorhamnetin conferred a protective effect against oxidative stress. Isorhamnetin also effectively attenuated $H_2O_2$-induced apoptosis and ROS generation, which was associated with the restoration of the upregulation of Bax and downregulation of Bcl-2 induced by $H_2O_2$. In addition, $H_2O_2$ enhanced the activation of caspase-9 and -3, and degradation of poly (ADP-ribose)-polymerase, a typical substrate protein of activated caspase-3; however, these events were almost totally reversed by pretreatment with isorhamnetin. Moreover, isorhamnetin increased the levels of heme oxygenase-1, a potent antioxidant enzyme, associated with the induction of Nrf2. Conclusions: Our data indicated that isorhamnetin may potentially serve as an agent for the treatment and prevention of muscle disorders caused by oxidative stress.

• The Korean Journal of Physiology and Pharmacology
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• v.3 no.3
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• pp.263-273
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• 1999

The role of phospholipase $A_2\;(PLA_2)$ in acute lung leak induced by intestinal ischemia was investigated in association with neutrophilic respiratory burst. To induce lung leak, we generated intestinal ischemia for 60 min prior to the 120 min reperfusion by clamping superior mesenteric artery in Sprague-Dawley rats. Acute lung leak was confirmed by the increased lung leak index and protein content in bronchoalveolar fluid. These changes were inhibited by mepacrine, the non-specific $PLA_2$ inhibitor. The lung myeloperoxidase (MPO) activity denoting the pulmonary recruitment of neutrophils was increased by intestinal I/R, but decreased by mepacrine. Simultaneously, the number of leukocytes in bronchoalveolar fluid was increased by intestinal ischemia/reperfusion (I/R) and decreased by mepacrine. Gamma glutamyl transferase activity, an index of oxidative stress in the lung, was increased after intestinal I/R but decreased by mepacrine, which implicates that $PLA_2$ increases oxidative stress caused by intestinal I/R. The $PLA_2$ activity was increased after intestinal I/R not only in the intestine but also in the lung. These changes were diminished by mepacrine. In the cytochemical electron microscopy to detect hydrogen peroxide, intestinal I/R increased the generation of the hydrogen peroxide in the lung as well as in the intestine. Expression of interleukin-1 (IL-1) in the lung was investigated through RT-PCR. The expression of IL-1 after intestinal I/R was enhanced, and again, the inhibition of $PLA_2$ suppressed the expression of IL-1 in the lung. Taken together, intestinal I/R seems to induce acute lung leak through the activation of $PLA_2$, the increase of IL-1 expression associated with increased oxidative stress by neutrophilic respiratory burst.

• Journal of Radiation Industry
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• v.8 no.1
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• pp.35-42
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• 2014

This study was conducted to analyze the protective capacity of cyanidin-3-glucoside (C3G), which is rich in mulberry and blackberry as an anthocyanin pigment. In this study, we found that treatment with C3G significantly reduced ROS production in hydrogen peroxide $(H_2O_2)-treated$ HepG2 cells in a dose-dependent manner. In addition, treatment with C3G significantly increased the cell viability in a dose-dependent manner in $H_2O_2-treated$ HepG2 cells. Moreover, treatment with C3G dose-dependently decreased the release of LDH and activation of caspase-3 in HepG2 cells treated with $H_2O_2$. Furthermore, the DNA damage in $H_2O_2-treated$ HepG2 cells was decreased by C3G treatment when compared with the control group in a dose-dependent manner. Additionally, treatment with C3G recovered the activity of antioxidant enzymes such as superoxide dismutase and catalase in $H_2O_2-treated$ HepG2 cells. To summarize, these results suggest that C3G protects cells from $H_2O_2-induced$ oxidative damage by activating antioxidant enzymes.

• The Korea Journal of Herbology
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• v.28 no.5
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• pp.45-52
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• 2013

Objectives : This study aims at examining the immuno-modulating activity in the fermentative extract of the root of Scutellaria baicalensis Georgi (Scutellariae Radix) on the production of inflammatory mediator in LPS-stimulated RAW264.7 mouse macrophages. Method : Measurements were done for the influences on the cell viability, generation of hydrogen peroxide in cells and nitric oxide (NO) generation using the macrophage of mouse with the specimen SBS as the fermentative extract of Scutellariae Radix (SBS) with Saccharomyces cerevisiae STV89. Result : As a result of carrying out MTT assay to check the cellular toxicity of the fermentative extract of Scutellariae Radix, any excessive toxicity to the macrophage did not occur from treatments by concentration for SBS. SBS increased the generation of hydrogen peroxide in the macrophage. SBS suppressed the NO generated in macrophages and SBS concentration higher than $25{\mu}g/mL$ significantly suppressed the increased NO generated in LPS-stimulated macrophages. SBS concentration higher than $25{\mu}g/mL$ significantly suppressed the generation of IL-6, IL-10, IL-12p40 and MCP-1 in LPS-stimulated macrophages. Conclusion : Our findings indicate that SBS has an immuno-modulating activity in macrophage activation through suppressing the generation of inflammatory substances, NO, IL-6, IL-10, IL-12p40 and MCP-1.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.3
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• pp.149-156
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• 2011

Golgi SNAP receptor complex 1 (GS28) has been implicated in vesicular transport between intra-Golgi networks and between endoplasmic reticulum (ER) and Golgi. Additional role(s) of GS28 within cells have not been well characterized. We observed decreased expression of GS28 in rat ischemic hippocampus. In this study, we examined the role of GS28 and its molecular mechanisms in neuronal (SK-N-SH) cell death induced by hydrogen peroxide ($H_2O_2$). GS28 siRNA-transfected cells treated with $H_2O_2$ showed a significant increase in cytotoxicity under glutathione (GSH)-depleted conditions after pretreatment with buthionine sulfoximine, which corresponded to an increase of intracellular reactive oxygen species (ROS) in the cells. Pretreatment of GS28 siRNA-transfected cells with p38 chemical inhibitor significantly inhibited cytotoxicity; we also observed that p38 was activated in the cells by immunoblot analysis. We confirmed the role of p38 MAPK in cotransfected cells with GS28 siRNA and p38 siRNA in the cell viability assay, flow cytometry, and immunoblot. Involvement of apoptotic or autophagic processes in the cells was not shown in the cell viability, flow cytometry, and immunoblot analyses. However, pretreatment of the cells with necrostatin-1 completely inhibited $H_2O_2$-induced cytotoxicity, ROS generation, and p38 activation, indicating that the cell death is necroptotic. Collectively these data imply that $H_2O_2$ induces necroptotic cell death in the GS28 siRNA-transfected cells and that the necroptotic signals are mediated by sequential activations in RIP1/p38/ROS. Taken together, these results indicate that GS28 has a protective role in $H_2O_2$-induced necroptosis via inhibition of p38 MAPK in GSH-depleted neuronal cells.

• Journal of the Korean Society of Safety
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• v.17 no.2
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• pp.45-51
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• 2002

This study is the series of photopolymerization on alkyl methacrylate(AMA) to continue further research. The objective of this work is to investigate the environmental fraternitive characteristics of photopolymerization kinetics on n-Buthyl methacrylate(BMA) and comparing the decomposition behavior to other AMA. The experiment was done in aqueous solution under the influence of photo-initiator concentration$(0.05{\sim}0.25mol/l)$, light intensity$(5000{\sim}9000{\mu}J/cm^{2})$ and monomer concentration$(2.0{\sim}6.0mol/l)$. n-BMA was polymerized to high conversion ratio using hydrogen $peroxide(H_{2}O_{2})$, and the kinetics model we have obtained is as follows. $R_{p}=K_{p}[S]^{0.24}[M]^{0.33}[L]^{153}exp^{(27.19/RT)}$ The differential method of thermogravimetric analysis(Friedman method) was used to obtain value of activation energy on decomposition reaction. The average value of it was 27.5Kcal/mol.

• The Korean Journal of Physiology and Pharmacology
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• v.12 no.2
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• pp.65-71
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• 2008

The present study examined the inhibitory effect of licorice compounds glycyrrhizin and a metabolite $18{\beta}$-glycyrrhetinic acid on the neurotoxicity of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in the mouse and on the 1-methyl-4-phenylpyridinium ($MPP^+$)-induced cell death in differentiated PC12 cells. MPTP treatment increased the activities of total superoxide dismutase, catalase and glutathione peroxidase and the levels of malondialdehyde and carbonyls in the brain compared to control mouse brain. Co-administration of glycyrrhizin (16.8 mg/kg) attenuated the MPTP effect on the enzyme activities and formation of tissue peroxidation products. In vitro assay, licorice compounds attenuated the $MPP^+$-induced cell death and caspase-3 activation in PC12 cells. Glycyrrhizin up to $100{\mu}M$ significantly attenuated the toxicity of $MPP^+$. Meanwhile, $18{\beta}$-glycyrrhetinic acid showed a maximum inhibitory effect at $10{\mu}M$; beyond this concentration the inhibitory effect declined. Glycyrrhizin and $18{\beta}$-glycyrrhetinic acid attenuated the hydrogen peroxide- or nitrogen species-induced cell death. Results from this study indicate that glycyrrhizin may attenuate brain tissue damage in mice treated with MPTP through inhibitory effect on oxidative tissue damage. Glycyrrhizin and $18{\beta}$-glycyrrhetinic acid may reduce the $MPP^+$ toxicity in PC12 cells by suppressing caspase-3 activation. The effect seems to be ascribed to the antioxidant effect.