• Nutrition Research and Practice
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• v.8 no.2
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• pp.138-145
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• 2014

BACKGROUND/OBJECTIVES: This study was performed to investigate the in vitro antioxidant and cytoprotective effects of fermented sesame sauce (FSeS) against hydrogen peroxide ($H_2O_2$)-induced oxidative damage in renal proximal tubule LLC-PK1 cells. MATERIALS/METHODS: 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical ($^{\bullet}OH$), and $H_2O_2$ scavenging assay was used to evaluate the in vitro antioxidant activity of FSeS. To investigate the cytoprotective effect of FSeS against $H_2O_2$-induced oxidative damage in LLC-PK1 cells, the cellular levels of reactive oxygen species (ROS), lipid peroxidation, and endogenous antioxidant enzymes including catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-px) were measured. RESULTS: The ability of FSeS to scavenge DPPH, $^{\bullet}OH$ and $H_2O_2$ was greater than that of FSS and AHSS. FSeS also significantly inhibited $H_2O_2$-induced ($500{\mu}M$) oxidative damage in the LLC-PK1 cells compared to FSS and AHSS (P < 0.05). Following treatment with $100{\mu}g/mL$ of FSeS and FSS to prevent $H_2O_2$-induced oxidation, cell viability increased from 56.7% (control) to 83.7% and 75.6%, respectively. However, AHSS was not able to reduce $H_2O_2$-induced cell damage (viability of the AHSS-treated cells was 54.6%). FSeS more effectively suppressed $H_2O_2$-induced ROS generation and lipid peroxidation compared to FSS and AHSS (P < 0.05). Compared to the other sauces, FSeS also significantly increased cellular CAT, SOD, and GSH-px activities and mRNA expression (P < 0.05). CONCULUSIONS: These results from the present study suggest that FSeS is an effective radical scavenger and protects against $H_2O_2$-induced oxidative damage in LLC-PK1 cells by reducing ROS levels, inhibiting lipid peroxidation, and stimulating antioxidant enzyme activity.

• Journal of Pharmacopuncture
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• v.19 no.1
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• pp.51-58
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• 2016

Objectives: Oldenlandia diffusa is traditionally used to relieve the symptoms of and to treat various diseases, but its anti-cancer activity has not been well studied. In the present study, the authors investigated the anti-cancer effects of an ethanol extract of Oldenlandia diffusa (EOD) on HT-29 human adenocarcinoma cells. Methods: Cells were treated with different concentrations of an EOD, and cell death was assessed by using a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Analyses of the sub G1 peak, the caspase-3 and -9 activities, and the mitochondrial membrane depolarizations were conducted to confirm cell death by apoptosis. Also, intracellular reactive oxygen species (ROS) generation was determined using carboxy-H2DCFDA (5-(and-6)-carboxy-20,70-dichlorodihydrofluorescein diacetate). Results: EOD inhibited the proliferation of HT-29 cells for 24 hours by $78.6%{\pm}8.1%$ at $50{\mu}g/mL$, $74.4%{\pm}4.6%$ at $100{\mu}g/mL$, $65.9%{\pm}5.2%$ at $200{\mu}g/mL$, $51.4%{\pm}6.2%$ at $300{\mu}g/mL$, and by $41.7%{\pm}8.9%$ at $400{\mu}g/mL$, and treatment for 72 hours reduced the proliferation at the corresponding concentrations by $43.3%{\pm}8.8%$, $24.3{\pm}5.1mV$, $13.5{\pm}3.2mV$, $6.5{\pm}2.3mV$, and by $2.6{\pm}2.3mV$. EOD increased the number of cells in the sub-G1 peak in a dose-dependent manner. The mitochondrial membrane depolarization was elevated by EOD. Also, caspase activities were dose-dependently elevated in the presence of EOD, and these activities were repressed by a pan-caspase inhibitor (zVAD-fmk). The ROS generation was significantly increased by EOD and N-acetyl-L-cysteine (NAC; a ROS scavenger) remarkably abolished EOD-induced cell death. In addition, a combination of sub-optimal doses of EOD and chemotherapeutic agents noticeably suppressed the growth of HT-29 cancer cells. Conclusion: These results indicate that EOD might be an effective chemotherapeutic for the treatment of human colorectal cancer.

• International Journal of Oral Biology
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• v.35 no.2
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• pp.61-67
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• 2010

Selenoprotein S (SelS) is widely expressed in diverse tissues where it localizes in the plasma membrane and endoplasmic reticulum. We studied the potential function of SelS in erythrocyte differentiation using K562 cells stably over-expressing SelS wild-type (WT) or one of two SelS point mutants, $U_{188}S$ or $U_{188}C$. We found that in the K562 cells treated with $1\;{\mu}M$ Ara-C, SelS gradually declined over five days of treatment. On day 4, intracellular ROS levels were higher in cells expressing SelS-WT than in those expressing a SelS mutant. Moreover, the cell cycle patterns in cells expressing SelS-WT or $U_{188}C$ were similar to the controls. The expression and activation of SIRT1 were also reduced during K562 differentiation. Cells expressing SelS-WT showed elevated SIRT1 expression and activation (phosphorylation), as well as higher levels of FoxO3a expression. SIRT1 activation was diminished slightly in cells expressing SelS-WT after treatment with the ROS scavenger NAC (12 mM), but not in those expressing a SelS mutant. After four days of Ara-C treatment, SelS-WT-expressing cells showed elevated transcription of $\beta$-globin, $\gamma$-globin, $\varepsilon$-globin, GATA-1 and zfpm-1, whereas cells expressing a SelS mutant did not. These results suggest that the suppression of SelS acts as a trigger for proerythrocyte differentiation via the ROS-mediated downregulation of SIRT1.

• BMB Reports
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• v.48 no.7
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• pp.395-400
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• 2015

Parkinson's disease (PD) is a neurodegenerative disability caused by a decrease of dopaminergic neurons in the substantia nigra (SN). Although the etiology of PD is not clear, oxidative stress is believed to lead to PD. Catalase is antioxidant enzyme which plays an active role in cells as a reactive oxygen species (ROS) scavenger. Thus, we investigated whether PEP-1-Catalase protects against 1-methyl-4-phenylpyridinium (MPP⁺) induced SH-SY5Y neuronal cell death and in a 1-methyl-4-phenyl-1,2,3,6-trtrahydropyridine (MPTP) induced PD animal model. PEP-1-Catalase transduced into SH-SY5Y cells significantly protecting them against MPP⁺-induced death by decreasing ROS and regulating cellular survival signals including Akt, Bax, Bcl-2, and p38. Immunohistochemical analysis showed that transduced PEP-1-Catalase markedly protected against neuronal cell death in the SN in the PD animal model. Our results indicate that PEP-1-Catalase may have potential as a therapeutic agent for PD and other oxidative stress related diseases. [BMB Reports 2015; 48(7): 395-400]

• International Journal of Oral Biology
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• v.34 no.1
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• pp.7-14
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• 2009

Nitric oxide (NO) acts as an intracellular messenger at the physiological level but can be cytotoxic at high concentrations. The cells within periodontal tissues, such as gingival and periodontal fibroblasts, contain nitric oxide syntheses and produce high concentrations of NO when exposed to bacterial lipopolysaccharides and cytokines. However, the cellular mechanisms underlying NO-induced cytotoxicity in periodontal tissues are unclear at present. In our current study, we examined the NO-induced cytotoxic mechanisms in human gingival fibroblasts (HGF). Cell viability and the levels of reactive oxygen species (ROS) were determined using a MTT assay and a fluorescent spectrometer, respectively. The morphological changes in the cells were examined by Diff-Quick staining. Expression of the Bcl-2 family and Fas was determined by RT-PCR or western blotting. The activity of caspase-3, -8 and -9 was assessed using a spectrophotometer. Sodium nitroprusside (SNP), a NO donor, decreased the cell viability of the HGF cells in a dose- and time-dependent manner. SNP enhanced the production of ROS, which was ameliorated by NAC, a free radical scavenger. ODQ, a soluble guanylate cyclase inhibitor, did not block the SNP-induced decrease in cell viability. SNP also caused apoptotic morphological changes, including cell shrinkage, chromatin condensation, and DNA fragmentation. The expression of Bax, a member of the proapoptotic Bcl-2 family, was upregulated in the SNP-treated HGF cells, whereas the expression of Bcl-2, a member of the anti-apoptotic Bcl-2 family, was downregulated. SNP augmented the release of cytochrome c from the mitochondria into the cytosol and enhanced the activity of caspase-8, -9, and -3. SNP also upregulated Fas, a component of the death receptor assembly. These results suggest that NO induces apoptosis in human gingival fibroblast via ROS and the Bcl-2 family through both mitochondrial- and death receptor-mediated pathways. Our data also indicate that the cyclic GMP pathway is not involved in NO-induced apoptosis.

• Journal of Life Science
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• v.7 no.1
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• pp.10-16
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• 1997

This study was designed as a part of efforts to investigate the biochemical pollutant markers for diagnosis of marine pollutions by changes in oxygen radicals and their scavenger enzymes of the flounder (Paralichthys olivaceus)in Yellow Sea of Kores. Protein contents in brian and muscle of cultured flounder in Yellow Sea were remarkably lower(30-45% and 25-45%, respectively) than those of wild flounders in Pohang(control) of East Sea. Lipid peroxide(LPO) levels in serum of cultured and wild flounders in Yellow Sea were significanltly higher (30-80% and 125-145%, respectively)than those of wild flounder in Pohang. Hydroxide radical formations and superoxide dismutase(SOD) activities in serum of cultured flounders in Yellow Sea were significantly 15-30% and 15-35% lower than those of wild flounders in Pohang, but glutathione peroxidase (GSHPx) activities in brain of cultured flounders in Yellow Sea were significantly 15-25% higher than those of wild flounders in Pohang. It is believed that significantly decreases of protein contents in brain anad muscle, remakable increases of malondialdehyde(LPO) in serum and glutathione peroxidase (GSHPx)in brain of cultured flounders of Yellow Sea may be used as a biochemical pollutant markers for diagnosis of marine pollutions.

• Journal of Life Science
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• v.9 no.3
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• pp.276-281
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• 1999

This study was designed as a part of efforts to investigate the biochemical pollutant markers for diagnosis of marine pollutions by changes in oxygen radicals and their scavenger enzymes of the mussel (Mytilus coruscus) in South Sea of Korea. Protein contents in muscle of cultured mussel in South Sea were remarkably lower (4-14%, respectively) than those of wild mussel in Pohang of East Sea. Superoxide radical activities in muscle of cultured in South Sea were significantly higher 82∼138% than those of wild mussel in Pohang. Hydroxyl radical formations in muscle of cultured mussels in South Sea were significantly 9∼25% higher than those of wild mussels in Pohang. Superoxide dismutase (SOD) activities in muscle of cultured mussels in South Sea were significantly 16∼28% lower than those of wild mussels in Pohang. It is believed that significantly decrease of protein contents in muscle, remarkable increases of superoxide radical and hydroxyl radical in muscle of cultured mussels of South Sea may be used as a biochemical pollutant markers for diagnosis of marine pollutions. These results suggest that near-coastal water as well as neritic water of the south sea might be affected by pollutant.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.1
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• pp.13-24
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• 2006

Neuronal apoptotic events, consequently resulting in neuronal cell death, are occurred in hypoxic/ischemic condition. This cell death has been shown to be accompanied with the production of reactive oxygen species (ROS), which can attack cellular components such as nucleic acids, proteins and phospholipid. However, the underlying mechanisms of apoptosis induced in hypoxic/ischemic condition and its treatment methods are unsettled. Cobalt chloride $(CoCl_2)$ has been known to mimic hypoxic condition including the production of ROS. Epigallocatechin gallate (EGCG), a green tea polyphenol, has diverse pharmacologial activities in cell growth and death. This study was aimed to investigate the apoptotic mechanism by $CoCL_2$ and effects of EGCG on $CoCl_2-induced$ apoptosis in PC12 cells. Administration of $CoCl_2$ decreased cell survival in dose- and time-dependent manners and induced genomic DNA fragmentation. Treatment with $100{\mu}M$ EGCG for 30 min before PC12 cells were exposed to $150{\mu}M$ $CoCl_2$, being resulted in the cell viability and DNA fragmentation being rescued. $CoCl_2$ caused morphologic changes such as cell swelling and condensed nuclei whereas EGCG attenuated morphologic changes by $CoCl_2$. EGCG suppressed the apoptotic peak and a loss of ${\Delta}{\psi}_m$ induced by $CoCl_2$. $CoCl_2$ decreased Bcl-2 expression but Bax expression was not changed in $CoCl_2$- treated cells. EGCG attenuated the Bcl-2 underexpression by $CoCl_2$. $CoCl_2$ augumented the cytochrome c release from mitochondria into cytoplasm and increased caspase-8, -9 and caspase-3 activity a marker of the apoptotic executing stage. EGCG ameliorated the incruement in caspase-8, -9 and -3 activity, and cytochrome c release by $CoCl_2$ NAC (N-acetyl-cysteine), a scavenger of ROS, attenuated $CoCl_2-induced$ apoptosis in consistent with those of EGCG. These results suggest that $CoCl_2$ induces apoptotic cell death through both mitochondria- and death receptor-dependent pathway and EGCG has neuroprotective effects against $CoCl_2-induced$ apoptosis in PC12 cells.

• Journal of Life Science
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• v.17 no.9 s.89
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• pp.1204-1210
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• 2007

The topoisomerase II inhibitor etoposide causes an accumulation of DNA double strand breaks within the nuclei of cells. In this study, we investigated the effect of etoposide on the cell growth and apoptosis of human RPE cells. Etoposide evoked a significant inhibition of cell growth, and also induced DNA fragmentation in ARPE-19 cells. In addition, etoposide significantly up-regulated the expression of heme oxygenase-1 (HO-1), which is a stress-responsive protein and is known to play a protective role against the oxidative injury. And, etoposide-induced HO-1 expression was affected by the ROS scavenger N-acetyl cysteine. We also used oligonucleotides interfering with HO-1 mRNA (siRNA) for the inhibition of HO-1 expression. Interestingly, knock-down of the HO-1 gene significantly increased the level of DNA fragmentation in etoposide-treated ARPE-19 cells. In conclusion, these results suggest that up-regulated HO-1 plays as an anti-apoptotic factor in the process of apoptosis of ARPE-19 cells stimulated by etoposide.

• Journal of Life Science
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• v.25 no.6
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• pp.656-662
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• 2015

Natural products and natural product structures play a general and highly significant role in drug discovery and development process because it has various merits and potentials for new drug source that have extensive clinical experience, development time contraction, excellent stability and safety. In several neurological disorders, neuronal death and excessive activation of microglia (neuro-inflammation) are observed. A number of drug discovery-related neuronal cell death and neuro-inflammation was studied from natural products, respectively. However, until now, it has not been possible to study dual-protection molecules recorded in the Natural Product library. In the present study, using the natural product-derived library of the Institute for Korea Traditional Medical Industry, we investigated dual-protective molecules against glutamate (a classical excitatory neurotransmitter)-induced oxidative stress mediated neuronal cell death and LPS-induced excessive activated microglial cells (immune cells of the brain). Chrysophanol, extracted from Rheum palmatum, had dual-protective effects against both glutamate-induced neuronal cell death and LPS-induced NO production, triggering proinflammatory cytokines and microglia activation and resulting in neuroinflammation. Flow-cytometry analysis revealed that chrysophanol had a scavenger effect, scavenging glutamate- and LPS-induced reactive oxygen species (ROS) produced by neuronal and microglial cells, respectively. Based on the present study, chrysophanol may have an important protective role against neuronal cell death and neuroinflammation in the brain. The results may be helpful for studying drug development candidates for treating central nervous system disorders.