• Korean Journal of Plant Resources
• /
• v.23 no.2
• /
• pp.165-171
• /
• 2010

Oxidative stress induced by reactive oxygen intermediates has been implicated in a variety of human diseases including neurodegenerative disorders, cancer, cardiovascular and respiratory diseases, and mode of action of environmental toxicants. Tert-butylhydroperoxide (t-BHP) is an organic lipid hydroperoxide analogue, which is commonly used as a pro-oxidant for evaluating mechanisms involving oxidative stress in cells and tissues. In this study, the underlying mechanisms involved in the protective effects of Hwabuk 94 kiwifruit (Actinidia deliciosa cv. 'Hwabuk 94'), which is cultivated in Jeju, on the t-BHP-induced cytotoxicity in PC12 cell. The pretreatment of rat pheochromocytoma cell line PC12 with Hwabuk 94 extract ($1-100\;{\mu}g/ml$) resulted in a significant recovery from t-BHP-induced cell death and increased Bcl-2 and procaspase-3 expression, whereas the expression of Bax and cleaved PARP were decreased in a dose-dependent manner compared to the control. Furthermore, Hwabuk 94 inhibited the t-BHP-induced p38 MAP kinase and extracellular signal-regulated kinase 1/2, but not c-Jun N-terminal kinase activations. Finally, these findings suggest that Hwabuk 94 kiwifruit might attenuate t-BHP-induced PC12 cell cytotoxicity, at least in part, through the inhibition of signaling pathways mediated by the ERK1/2 and p38 MAP kinase.

• Molecular & Cellular Toxicology
• /
• v.4 no.2
• /
• pp.157-163
• /
• 2008

Formation of ${\beta}$-amyloid $(A{\beta})$ fibrils has been identified as one of the major characteristics of Alzheimer's disease (AD). Inhibition of $A{\beta}$ fibril formation in the CNS would be attractive therapeutic targets for the treatment of AD. Several small compounds that inhibit amyloid formation or amyloid neurotoxicity in vitro have been known. Citrate has surfactant function effect because of its molecular structure having high anionic charge density, in addition to the well-known antibacterial and antioxidant properties. Therefore, we hypothesized that citrate might have the inhibitory effect against $A{\beta}$ fibril formation in vitro and have the protective effect against $A{\beta}$-induced neurotoxicity in PC12 cells. We examined the effect of citrate against the formation of $A{\beta}$ fibrils by measuring the intensity of fluorescence in thioflavin-T (Th-T) assay of between $A{\beta}_{25-35}$ groups treated with citrate and the control with $A{\beta}_{25-35}$ alone. The neuroprotective effect of citrate against $A{\beta}$-induced toxicity in PC12 cells was investigated using the WST-1 assay. Fluorescence spectroscopy showed that citrate inhibited dose-dependently the formation of $A{\beta}$ fibrils from ${\beta}$-amyloid peptides. The inhibition percentages of $A{\beta}$ fibril formation by citrate (1, 2.5, and 5 mM) were 31%, 60%, and 68% at 7 days, respectively in thioflavin-T (Th-T) assay. WST-1 assay revealed that the toxic effect of $A{\beta}_{25-35}$ was reduced, in a dose-dependent manner to citrate. The percentages of neuroprotection by citrate (1, 2.5, and 5 mM) against $A{\beta}-induced$ toxicity were 19%, 31 %, and 34%, respectively. We report that citrate inhibits the formation of $A{\beta}$ fibrils in vitro and has neuroprotective effect against $A{\beta}$-induced toxicity in PC12 cells. Neuroprotective effects of citrate against $A{\beta}$ might be, to some extent, attributable to its inhibition of $A{\beta}$ fibril formation. Although the mechanism of anti-amyloidogenic activity is not clear, the possible mechanism is that citrate might have two effects, salting-in and surfactant effects. These results suggest that citrate could be of potential therapeutic value in Alzheimer's disease.

• Journal of Oriental Neuropsychiatry
• /
• v.17 no.1
• /
• pp.37-57
• /
• 2006

Objective : This research investigates the effect of the CMT and MCMT on Alzheimer‘s disease. Methods : The effects of the CMT and MCMT extract on (1) amyloid precursor proteins(APP), acetylcholinesterase(AChE) mRNA of PC-12 cells treated with CT-105; (2) the AChE activity and the APP production of PC-12 cell treated with CT-105; (3) the behavior; (4) expression of $IL-1{\beta}$, $TNF-{\alpha}$, MDA, GFAP, CD68 abd CD11b; (5) the infarction area of the hippocampus in Alzheimer's diseased mice induced with ${\beta}A$ were investigated. Results : 1. The CMT and MCMT extract suppressed the expression of APP, AChE, and mRNA in PC-12 cells treated with CT-105. 2. The CMT and MCMT extract suppressed the AChE activity, and the production of APP significantly in PC-12 cells treated with CT-105. 3. For the CMT and MCMT extract group a significant inhibitory effect on the memory deficit was shown for the mice with Alzheimer's disease induced by ${\beta}A$ in the Morris water maze experiment, which measured stop-through latency, and distance movement-through latency. 4. The CMT and MCMT extract suppressed the over-expression of $IL-1{\beta}$, $TNF-{\alpha}$, MDA, GFAP, CD68 abd CD11bCD68/GFAP, in the mice with Alzheimer's disease induced by ${\beta}A$. 5. The CMT and MCMT extract reduced the infarction area of hippocampus with Alzheimer's disease induced by ${\beta}A$ 6. The MCMT showed more excellent effects than CMT in the every experiments except PC-12 cells. Conclusions : These results suggest that the CMT and MCMT extract may be effective for the prevention and treatment of Alzheimer's disease. Investigation into the clinical use of the CMT and MCMT extract for Alzheimer's disease is suggested for future research.

• Korean Journal of Food Science and Technology
• /
• v.49 no.5
• /
• pp.538-543
• /
• 2017

Astringent persimmon (Diospyros kaki Thunb. cv. Cheongdo-Bansi) peel with the astringency removed, which is a by-product of dried persimmon (gotgam), was investigated for its antioxidant and neuroprotective properties. A mixture of peel and 40% (v/v) aqueous ethanol was subjected to ultrasonication and then thermal and nonthermal treatments, to produce thermally-treated and nonthermally-treated persimmon peel extracts (TPE and NTPE, respectively). The total phenolic and flavonoid contents and the antioxidant capacity of TPE was approximately 1.3-1.8 times higher than those of NTPE. TPE resulted in the increased viability of neuronal PC-12 cells compared with NTPE. Furthermore, intracellular oxidative stress in PC-12 cells was more decreased by treatment with TPE than NTPE. Cholinesterases, such as acetylcholinesterase and butyrylcholinesterase, were more inhibited by treatment with TPE than NTPE. These results suggest that TPE is useful as a functional material to decrease oxidative stress in neuronal cells and to inhibit cholinesterases.

• Korean Journal of Plant Resources
• /
• v.26 no.4
• /
• pp.417-425
• /
• 2013

The aim of this study was to examine improving effect of Platycodon extracts (PE) and/or Platycodon extracts jelly (PEJ) on cognitive impairment in vitro and in vivo. PC12 (Pheochromocytoma) cells were pretreated with PE for 1hr and than incubated with $50{\mu}M$ amyloid ${\beta}(A{\beta})_{25-35}$ for additional 48hr. Cell viability was assessed by WST-1. Animals for Morris water test and passive avoidance test were divided into normal, control and two Platycodon extracts treated groups that were named Normal (n=7), Control (0 mg/kg, n=7), PE (300 mg/kg, n=7), PEJ (10 g/kg, n=7). Cognitive impairment was induced by scopolamine (1 mg/kg/body weight, i.p.) in the three experimental groups but not the normal group. Pretretment of PE (0.01-1 mg/mL) were not induced cytotoxicity but observed in high dose-treated group (5 and 10 mg/mL) in PC12 cells. Protective effects of PE against $A{\beta}$-induced cytotoxicity were increased in dose dependent manner in PC12 cells. Administration of PE and PEJ were significantly reduced escape latency time on Morris water maze test and passive avoidance test in copolamine-induced cognitive impairment animal model. These results suggest that Platycodon extracts and its related product available to ameliorative purpose for cognitive ability impairments.

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

• Molecules and Cells
• /
• v.27 no.5
• /
• pp.571-575
• /
• 2009

The amphetamine derivative 3, 4-methylenedioxymethamphetamine (MDMA) has become a popular recreational drug, and has also been shown to cause serotonergic neurotoxicity. This report shows that MDMA impairs brain development in a whole mouse embryo culture. The results of quantitative real-time PCR analysis showed that autophagy-related protein 5 (Atg5) expression is elevated in mouse embryo and neuroblastoma cells after MDMA treatment. This elevated Atg5 expression interferes with the neuronal differentiation of neuroblastoma cells such as SH-SY5Y and PC12 cells. Thus, our results suggest that the use of MDMA during pregnancy may impair neuronal development via an induction of Atg5 expression.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.16 no.2
• /
• pp.57-77
• /
• 2003

Objectives: The aim of this study was to investigate the depigmentation effects of Barley, Unpolished rice, Job's-tear. Metbods: We investigated that the extracts of Barley, Unpolished rice, Job's-tear inhibit activity of tyrosinase, the enzyme which convert ts 3-(3,4-dihydroxyphenyl) alanine to dopachrom in the biosynthetic process of melanin, the UV absorbance of the extracts in the UV-A region and UV-B region was measured by UV scanning, the effect of extracts on cell viability and melanin production in cultured B16 mouse melanoma cells were measured, and cytoprotective effects of extracts on PC12 cells injured by hydrogen peroxide measured by MTT assay. Results: The extracts of Barley, Unpolished rice, Job's-tear inhibited activity of tyrosinase in low density. The Barley, Job's-tear extracts not only showed inhibitory effects on melanin production in cultured B16 mouse melanoma cells, but also exhibited cytoprotective effects on PC12 cells injured by hydrogen peroxide in low density. Unpolished rice extract showed inhibitory effect on melanin production in cultured B16 mouse melanoma cells, but did not showed cytoprotective effect Barley, Unpolished rice, Job's-tear extracts did not showed an absorbance effect in the UV-A region and UV-8 region. Conclusions: These results suggest that Barley, Unpolished rice, Job's-tear inhibit melanin biosynthesis which is involved in hyperpigmentation and could be used as a whitening agent.

• Journal of Oriental Neuropsychiatry
• /
• v.21 no.1
• /
• pp.109-124
• /
• 2010

Objectives: This experiment was designed to investigate the effect of the InSamYangYoung-tang(Renshenyangrongtang) extract on $A{\beta}$-induced AD model. Methods: The effects of the InSamYangYoung-tang(Renshenyangrongtang) extract on neural damages of cultured PC12 cells induced by $A{\beta}$ were investigated. The effects of the InSamYangYoung-tang(Renshenyangrongtang) extract on neural damages of hippocampal and cortical neurons in the mouse induced by $\beta$-amyloid were investigated. Results: 1. $A{\beta}$ treatment into neuronal cells activated cell death pathway when analyzed by MTT assay and by histological analysis. Then InSamYangYoung-tang(Renshenyangrongtang) treatment improved cell survival to a similar level as in normal group. 2. $A{\beta}$ treatment increased caspase 3 protein levels but decreased phospho-Erk1/2 in neuronal cells. InSamYangYoung-tang(Renshenyangrongtang) treatment reversed the production levels of two proteins close to those in normal group. 3. $A{\beta}$ treatment induced the atrophy of neuronal cells in terms of neuronal processes and cell body shrinkage, but InSamYangYoung-tang(Renshenyangrongtang) greatly improved their morphology. 4. Neuroprotective activity, as observed in InSamYangYoung-tang(Renshenyangrongtang)-treated groups, was similarly observed in cells treated with galantamine which was used as a positive control. Moreover, overall recovery pattern by InSamYangYoung-tang(Renshenyangrongtang) was similar between cultured PC12 cells and in vivo hippocampal and cerebral cortical neurons in the mouse brain. Conclusions: This experiment shows that the InSamYangYoung-tang(Renshenyangrongtang) may play a protective role in neural tissues damaged by cytotoxic substances. Since neuronal damage seen in degenerative brains such as AD are largely unknown, the current data may provide possible insight into therapeutic strategies for AD treatments. InSamYangYoung-tang(Renshenyangrongtang) might be effective for the treatment of AD. Investigation into the clinical use of the InSamYangYoung-tang(Renshenyangrongtang) for AD is suggested for future research.

• Journal of Microbiology and Biotechnology
• /
• v.28 no.1
• /
• pp.40-49
• /
• 2018

We evaluated the antioxidant activity and neuronal cell-protective effect of fucoidan extract from Ecklonia cava (FEC) on hydrogen peroxide ($H_2O_2$)-induced cytotoxicity in PC-12 and MC-IXC cells to assess its protective effect against oxidative stress. Antioxidant activities were examined using the ABTS radical scavenging activity and malondialdehyde-inhibitory effect, and the results showed that FEC had significant antioxidant activity. Intracellular ROS contents and neuronal cell viability were investigated using the DCF-DA assay and MTT reduction assay. FEC also showed remarkable neuronal cell-protective effect compared with vitamin C as a positive control for both $H_2O_2$-treated PC-12 and MC-IXC cells. Based on the neuronal cell-protective effects, mitochondrial function was analyzed in PC-12 cells, and FEC significantly restored mitochondrial damage by increasing the mitochondrial membrane potential (${\Delta}{\Psi}m$) and ATP levels and regulating mitochondrial-mediated proteins (p-AMPK and BAX). Finally, the inhibitory effects against acetylcholinesterase (AChE), which is a critical hydrolyzing enzyme of the neurotransmitter acetylcholine in the cholinergic system, were investigated ($IC_{50}$ value = 1.3 mg/ml) and showed a mixed (competitive and noncompetitive) pattern of inhibition. Our findings suggest that FEC may be used as a potential material for alleviating oxidative stress-induced neuronal damage by regulating mitochondrial function and AChE inhibition.