• The Journal of Korean Medicine
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• v.31 no.3
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• pp.55-65
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• 2010

Background: Nitric oxide (NO) is a reactive free radical gas and a messenger molecule. NO has many physiological functions, but excessive NO production induces neurotoxicity. Objective: The present study investigated whether the aqueous extract of Polygala tenuifolia Willdenow possesses a protective effect on NO-induced apoptosis in human neuroblastoma cell line SK-N-MC. Method: For this study, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, 4,6-diamidino-2-phenylindole (DAPI) staining, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay, DNA fragmentation assay, reverse transcription-polymerase chain reaction (RT-PCR), Western blot, and caspase-3 enzyme assay were performed. Result: Sodium nitroprusside (SNP) exposure significantly decreased the viability of cells. The cells treated with SNP exhibited several apoptotic features such as increasing of Bax expression, caspase-3 enzyme activity and inhibiting of Bcl-2 expression. On the other hand, the viability of cells pre-treated with the aqueous extract of Polygala tenuifolia Willdenow was increased dose-dependently. The cells pre-treated for 1 h with the aqueous extract of Polygala tenuifolia Willdenow followed by treatment with SNP showed a decreased occurrence of apoptotic features like decreasing Bax expressions, caspase-3 enzyme activity and increasing Bcl-2 expressions. The aqueous extract of Polygala tenuifolia Willdenow reduced apoptotic cell death in neuroblastoma cell line SK-N-MC through the inhibition of Bax-dependent caspase-3 activation and the increasing of Bcl-2 expression. Conclusion: Based on the present results, it is possible that Polygala tenuifolia Willdenow has therapeutic value for the treatment of a variety of NO-induced brain diseases.

• Journal of Korean Neurosurgical Society
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• v.49 no.1
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• pp.13-19
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• 2011

Objective: The purpose of this study is to investigate the combined effects of ginkgo biloba extract, ginkgolide A and B and aspirin on SK-N-MC, human neuroblastoma cell viability and mRNA expression of growth associated protein43 (GAP43), Microtubule-associated protein 2 (MAP2), B-cell lymphoma2 (Bcl2) and protein53 (p53) gene in hypoxia and reperfusion condition. Methods: SK-N-MC cells were cultured with Dulbecco's Modified Eagle's Medium (DMEM) media in $37^{\circ}C$, 5% $CO_2$ incubator. The cells were cultured for 8 hours in non-glucose media and hypoxic condition and for 12 hours in normal media and $O_2$ concentration. Cell survival rate was measured with Cell Counting Kit-8 (CCK-8) reagent assay. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to estimate mRNA levels of GAP43, MAP2, Bcl2, and p53 genes. Results: The ginkgolide A and B increased viable cell number decreased in hypoxic and reperfused condition. The co-treatment of ginkgolide B with aspirin also increased the number of viable cells, however, there was no additive effect. Although there was no increase of mRNA expression of GAP43, MAP2, and Bcl2 in SK-N-MC cells with individual treatment of ginkgolide A, B or aspirin in hypoxic and reperfused condition, the co-treatment of ginkgolide A or B with aspirin significantly increased GAP43 and Bcl2 mRNA levels. In MAP2, only the co-treatment of ginkgolide A and aspirin showed increasing effect. The mRNA expression of p53 had no change in all treating conditions. Conclusion: This study suggests that the combined treatments of Ginkgo biloba extracts and aspirin increase the regeneration of neuroblastoma cells injured by hypoxia and reperfusion.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.3
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• pp.602-608
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• 2002

To investigate whether Puerariae radix (PR) possesses protective effect against ethanol (EtOH)-inducecl apoptosis in the central nervous system, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, flow cytometric analysis, DNA fragmentation assay. and reverse transcription-polymerase chain reaction (RT-PCR) were performed on human neuroblastoma cell line SK-N-MC. Morphological and biochemical analyses demonstrated that SK-N-MC cells treated with EtOH exhibit classical apoptotic features. On the other hand, cells pre-treated with PR prior to EtOH exposure showed decreased occurrence of classical apoptotic features. In addition, it was shown that PR pre-treatment inhibits EtOH-induced increases in the levels of mRNA expression of bax and caspase-3, while it further enhances the level of bcl-2 expression. These results suggest that PR may exert protective effects against EtOH-induced apoptosis in human neuroblastoma cells.

• Korean Journal of Pharmacognosy
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• v.27 no.4
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• pp.350-353
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• 1996

The effects of acid hydrolysis product of Panax ginseng and MeOH extract of Euphorbia humifusa on the growth of human brain tumor cells were evaluated using U-373 MG human astrocytoma and SK-N-MC human neuroblastoma cells as model cellular systems. These plant extracts induced cytotoxicity in both cells in a dose-dependent manner. These cytotoxic effects were significantly inhibited by GSH, an antioxidant, in both cells. BAPTA/AM, an intracellular $Ca^{2+}$ chelator, significantly blocked the cytotoxic effects of these extracts in U-373 cells, but enhanced these effects in SK-N-MC cells. These results suggest that the plant extracts may be a valuable choice for the studies on the treatment of human brain tumors.

• Nutrition Research and Practice
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• v.14 no.1
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• pp.3-11
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• 2020

BACKGROUND/OBJECTIVES: Oxidative stress causes cell damage and death, which contribute to the pathogenesis of neurodegenerative diseases. Urolithin A (UA), a gut microbial-derived metabolite of ellagitannins and ellagic acid, has high bioavailability and various health benefits such as antioxidant and anti-inflammatory effects. However, it is unknown whether it has protective effects against oxidative stress-induced cell death. We investigated whether UA ameliorates H₂O₂-induced neuronal cell death. MATERIALS/METHODS: We induced oxidative damage with 300 μM H₂O₂ after UA pretreatment at concentrations of 1.25, 2.5, and 5 μM in SK-N-MC cells. Cytotoxicity and cell viability were determined using the CCK-8 assay. The formation of reactive oxygen species (ROS) was measured using a 2,7-dichlorofluorescein diacetate assay. Hoechst 33342 staining was used to characterize morphological changes in apoptotic cells. The expressions of apoptosis proteins were measured using Western blotting. RESULTS: UA significantly increased cell viability and decreased intracellular ROS production in a dose-dependent manner in SK-N-MC cells. It also decreased the Bax/Bcl-2 ratio and the expressions of cytochrome c, cleaved caspase-9, cleaved caspase-3, and cleaved PARP. In addition, it suppressed the phosphorylation of the p38 mitogen-activated protein kinase (MAPK) pathway. CONCLUSIONS: UA attenuates oxidative stress-induced apoptosis via inhibiting the mitochondrial-related apoptosis pathway and modulating the p38 MAPK pathway, suggesting that it may be an effective neuroprotective agent.

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

• Biomolecules & Therapeutics
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• v.10 no.3
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• pp.142-151
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• 2002

The present study was attempted to investigate the effect of apamin on catecholamine (CA) secretion evoked by ACh, high $K^+$, DMPP, McN-A-343, cyclopiazonic acid and Bay-K-8644 from the isolated perfused rat adrenal gland and to establish the mechanism of its action. The perfusion of apamin (1 nM) into an adrenal vein for 20 min produced greatly potentiation in CA secretion evoked by ACh (5.32 $ imes$ $10^{-3}$ M), high $K^+$, (5.6 $ imes$ $10^{-2}$), DMPP ($10^{-4}$ M for 2 min), McN-A-343 ($10^{-4}$ M for 2 min), cyclopiazonic acid ($10^{-5}$ M for 4 min) and Bay-K-8644 ($10^{-5}$ M for 4 min). However, apamin itself did fail to affect basal catecholamine output. Furthermore, in adrenal glands preloaded with apamin (1 nM) under the presence of glibenclamide ($10^{-6}$ M), an antidiabetic sulfonylurea that has been shown to be a specific blocker of ATP-regulated potassium channels (for 20 min), CA secretion evoked by DMPP and McN-A-343 was not affected. However, the perfusion of high concentration of apamin (100 nM) into an adrenal vein for 20 min rather inhibited significantly CA secretory responses evoked by ACh, high $K^+$, DMPP, McN-A-343, cyclopiazonic acid and Bay-K-8644. Taken together, these results suggest that the low concentration of apamin causes greatly the enhancement of CA secretion evoked by stimulation of cholinergic (both nicotinic and muscarinic) receptors as well as by membrane depolarization. These findings suggests that apamin-sensitive SK ($Ca^{2+}$) channels located in rat adrenal medullary chromaffin cells may play an inhibitory role in the release of catecholamines mediated by stimulation of cholinergic nicotinic and muscarinic receptors as well as membrane depolarization. However, it is thought that high concentration of apamin cause the inhibitory responses in catecholamine secretion evoked by stimulation of cholinergic receptors as well as by membrane depolarization from the rat adrenal gland without relevance with the SK channel blockade.

• Food Science and Preservation
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• v.31 no.1
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• pp.99-111
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• 2024

The antioxidant potentials of ethanolic extracts derived from Aster yomena (A. yomena) were evaluated by assessing their total phenolic and flavonoid contents and radical scavenging activities. Our findings revealed that the 60% ethanolic extract of A. yomena exhibited the most robust antioxidant properties among all extracts tested. Specifically, the IC₅₀ values for the 2,2'-azino-bis (3-ethyl benzothiazoline-6-sulfonic acid) and 1,1-diphenyl-2-picrylhydrazyl radical scavenging activities of the 60% ethanolic extract from A. yomena were determined to be 1,640.30 ㎍/mL and 2,655.10 ㎍/mL, respectively. Moreover, the inhibitory effect on malondialdehyde increased with the 60% ethanolic extract from A. yomena. To assess the neuroprotective effects, we examined the impact of the 60% ethanolic extract from A. yomena against H₂O₂-induced cytotoxicity in HT-22 (mouse hippocampal neuronal cell line) and SK-N-MC (human neuroblastoma cell line) cells. The results demonstrated a significant improvement in cell viability and reduced intracellular oxidative stress. Furthermore, the major bioactive compounds present in the 60% ethanolic extract from A. yomena were identified as chlorogenic acid and rutin through high-performance liquid chromatography (HPLC) analysis.

• Proceedings of the Korean Society of Life Science Conference
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• 2003.05a
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• pp.77-77
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• 2003

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.112-112
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• 2001

Oxidative stress plays an important role in the pathological process of neurodegenerative diseases. Polychlorinated biphenyls (PCBs) are ubiquitous environmental contaminants, some of which may be neurotoxic. Our previous studies showed that 2,2',5,5'-TetracWorobiphenyl (PCB 52) induced apoptotic death in human neuronal SK-N-MC cells, which was demonstrated on gel electrophoresis by visualization of the proteolytic cleavages of $\beta$-catenin and poly (ADP-ribose) polymerase (PARP) and of the production of characteristic ladder patterns of DNA fragmentation.