• 생약학회지
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• 제41권3호
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• pp.221-226
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• 2010

The effects of sesamin on dopamine biosynthesis in PC12 cells were investigated. Sesamin at concentration ranges of 20-75 ${\mu}M$ significantly increased intracellular dopamine levels and tyrosine hydroxylase (TH) activities at 24 h: 50 ${\mu}M$ sesamin increased dopamine levels to 132% and TH activities to 128% of control levels. Sesamin (50 ${\mu}M$) induced the phosphorylation of TH, cyclic AMP-dependent protein kinase (PKA) and cyclic AMP-response element binding protein (CREB) for 0.5-24 h. Sesamin (50 ${\mu}M$) also increased the mRNA levels of TH and CREB for 3-24 h. In addition, sesamin (50 ${\mu}M$) associated with L-DOPA (50 and 100 ${\mu}M$) further increased the intracellular levels of dopamine for 24 h compared to L-DOPA alone. These results suggest that sesamin enhances dopamine biosynthesis and L-DOPA-induced increase in dopamine levels by inducing TH activity and TH gene expression, which is mediated by PKA-CREB systems in PC12 cells. Therefore, sesamin could serve as an adjuvant phytonutrient for neurodegenerative diseases.

• Food Science and Biotechnology
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• 제17권2호
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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.

• 생약학회지
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• 제34권1호통권132호
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• pp.55-59
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• 2003

The effects of liriodenine, an aporphine isoquinoline alkaloid, on dopamine content in PCl2 cells were investigated. Treatment of PC12 cells with liriodenine decreased dopamine content in a dose-dependent manner (33.6% inhibition at $10\;{\mu}M$ for 12 h). The $IC_{50}$ in value of liriodenine was $8.4\;{\mu}M$. Dopamine content decreased at 3 h and reached a minimal level at 12 h after the exposure to liriodenine. Under these conditions, the activities of tyrosine hydroxylase and aromatic L-amino acid decarboxylase were also inhibited at $10\;{\mu}M$ of liriodenine by 10.1% and 20.2% relative to control, respectively. In addition, liriodenine inhibited the increase in dopamine content induced by L-DOPA Treatments $(50-100\;{\mu}M)$ in PC12 cells. These results suggest that liriodenine inhibited dopamine biosynthesis and L-DOPA-induced increase in dopamine content by reducing the activities of tyrosine hydroxylase and aromatic L- amino acid decarboxylase in PC12 cells.

• Food Science and Biotechnology
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• 제15권5호
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• pp.735-738
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• 2006

We examined the neuroprotective and neurotrophic effects of genipin fractionated from gardenia (Gardenia jasminoides Ellis) originating from Korea. The neurotrophic effects of the genipin containing fraction was evaluated by microscopically monitoring its potency to induce neurite outgrowth in PC12h cells. The genipin containing fraction from Korean gardenia promoted neurite outgrowth in PC12h cells in this study, similar to previously reported effects by Wako Chemical, Japan. When cells were treated with the genipin containing fraction prior to ${\beta}$-amyloid peptide treatment (active domain of A peptide 25-35 treated), toxicity was significantly diminished (p<0.0l). These results suggest that genipin prepared from Korean gardenia might potentially be used as a precautionary agent in neurodegenerative disease, such as Alzheimer's disease, etc.

• Mycobiology
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• 제35권1호
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• pp.11-15
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• 2007

We examined the neuroprotective and neurotrophic effects of Tremella fuciformis. The neurotrophic effects of the hot water extract of T. fuciformis was evaluated by microscopically monitoring its potency to induce neurite outgrowth in PC12h cells. The hot water extract cf T. fuciformis promoted neurite outgrowth in PC12h cells in this study, superior to other natural substances which was reported previously. When cells were treated with the hot water extract of T. fuciformis prior to ${\beta}$-amyloid peptide treatment (active domain of A peptide $35{\sim}35$ treated), toxicity was significantly diminished (p<0.01). These results suggest that T. fuciformis might potentially be used as a precautionary agent in neurodegenerative disease, such as Alzheimer's disease, etc.

• 약학회지
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• 제49권2호
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• pp.156-161
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• 2005

Tetrahydropapaveroline (THP) at 5-15 ${\mu}$M has been found to induce L-DOPA-induced oxidative apoptosis in PC12 cells. In this study, the inhibitory effects of THP on dopamine bios ynthesis in PC12 cells and tyrosine hydroxylase (TH) activity in bovine adrenal were investigated. Treatment of PC12 cells with THP at 2.5-10 ${\mu}$M significantly decreased the intracellular dopamine content in a concentration-dependent manner (18.3% inhibition at 10 ${\mu}$M THP). In these conditions, TH activity was markedly inhibited by the treatment with THP at 2.5-10 ${\mu}$M in PC12 cells (23.4% inhibition at 10 $\mu$ M THP). In addition, THP had an inhibitory effect on bovine adrenal TH activity IC50 value, 153.9${\mu}$M). THP exhibited uncompetitive inhibition on bovine adrenal TH activity with a substrate L-tyrosine with the KI value of 0.30 mM. Treatment with L-DOPA at 20~50 ${\mu}$M increased the intracellular dopamine content in PC12 cells, and the increase in dopamine content by L-DOPA was inhibited in part when THP at non-cytotoxic (5-10 ${\mu}$M) or cytotoxic (15${\mu}$M) concentrations was associated with L-DOPA (20 and 50 ${\mu}$M) for 24 h incubation. These results suggest that THP at 5-10${\mu}$M decreases the basal dopamine content and reduces the increased dopamine content induced by L-DOPA in part by the inhibition of TH activity, and that THP at 15${\mu}$M also decreases dopamine content by oxidative stress in PC12 cells.

• 한국한의학연구원논문집
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• 제5권1호
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• pp.119-131
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• 1999

The effect of herbal medicine on 1-methyl-4-phenylpyridinium ion $(MPP^+)$ and 6-hydroxydopamine (6-OHDA) mediated neurotoxicity was studied in the rat phaeochromocytoma cell line PC12. The present study was designed to test the hypothesis that herbal medicine can protect cells from neurotoxiciy caused by $MPP^+$ and 6-OHDA. Exposure of PC12 cells to 0.2 mM $MPP^+$ and $50\;{\mu}M$ 6-OHDA for 24h resulted in a 50% cell death with respect to the control cells. $MPP^+$ induced cell death was reduced by Yollyounggobondan (延齡固本丹), Sagunjatang (四君子湯), Palmihwan (八味丸), and Palmultang (八物湯)(P<0.05). However, herbal medicines did not protect cells from degeneration caused by the 6-OHDA. Yollyounggobondan, Yungmijihwangwon (六味地黃元), Palmihwan, and Samultang (四物湯) were effective in protecting against $MPP^+$-induced ATP loss in PC12 cells (P<0.05). Yollyounggobondan and Palmultang were effect in neurite protection against 6-OHDA treatment in differentiated PC12 cells with NGF.

• 약학회지
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• 제50권2호
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• pp.105-110
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• 2006

The effects of tributyltin acetate (TBTA), one of the endocrine-disrupting organotin compounds, on dopamine biosynthesis in PC12 cells were investigated. Treatment of PC12 cells with TBTA at $0.05\sim0.25{\mu}M$ significantly decreased the intracellular dopamine content in a concentration-dependent manner ($IC_{50}$ value, $0.17{\mu}M$). Under these conditions, tyrosine hydroxylase (TH) activity and TH mRNA level were also decreased by $0.1{\mu}M$ TBTA at 24 h, and recovered there-after. In addition, treatment with L-DOPA at 20 and $50 {\mu}M$ increased the intracellular dopamine content in PC12 cells and the increase in dopamine content by L-DOPA was significantly abolished by TBTA at $0.1\sim0.2{\mu}M$. These results indicate that TBTA at $0.1\sim0.2{\mu}M$ causes the decrease in the basal dopamine content and abolishes the increase in dopamine content in L-DOPA-treated cells in part by the inhibition of TH gene expression and activity.

• Applied Biological Chemistry
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• 제50권1호
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• pp.63-67
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• 2007

본 연구에서는 석곡(Dendrobium nobile Lindl.) 추출물에 대한 신경세포 보호 효과를 확인하기 위하여 $H_{2}O_{2}$에 의해 유도된 스트레스 상태의 PC12 세포주에서 MTT-dye reduction assay와 LDH release assay를 이용하였다. MTT reduction assay 결과, 스트레스 상태에서는 47%의 생존율을 보인데 반하여 석곡 추출물 50${\mu}$g/ml 농도로 처리하였을 때 99.5%의 높은 세포 생존율을 확인할 수 있었다. 이 결과는 LDH release assay 에서도 일치하는 결과를 확인하였다. 그리고 광학 현미경을 이용한 형태학적 변화를 관찰한 결과에서도 신경돌기의 출현 유도를 통한 신경세포 생존을 확인 할 수 있었다. 또한 핵의 변화에 미치는 영향을 관찰한 결과 정상 세포의 핵은 타원형의 온전한 핵 모양을 나타낸 반면 산화적 손상을 입은 세포는 apoptotic body가 핵 주변에 나타나는 전형적인 apoptosis를 나타내었고 석곡 추출물을 처리한 결과 핵의 condersation현상과 fragmentation이 현저히 감소함을 확인 할 수 있었다. 그리고 $H_{2}O_{2}$에 의한 capase-3의 활성은 석곡 추출물을 50${\mu}$g/ml 처리 후 약 1.1배 이하로 감소함을 보였다.

• Natural Product Sciences
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• 제24권2호
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• pp.99-102
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• 2018

This study investigated the effects of ombuoside, a flavonol glycoside, on dopamine biosynthesis in PC12 cells. Ombuoside at concentrations of 1, 5, and $10{\mu}M$ increased intracellular dopamine levels at 1 - 24 h. Ombuoside (1, 5, and $10{\mu}M$) also significantly increased the phosphorylation of tyrosine hydroxylase (TH) (Ser40) and cyclic AMP-response element binding protein (CREB) (Ser133) at 0.5 - 6 h. In addition, ombuoside (1, 5, and $10{\mu}M$) combined with L-DOPA (20, 100, and $200{\mu}M$) further increased intracellular dopamine levels for 24 h compared to L-DOPA alone. These results suggest that ombuoside regulates dopamine biosynthesis by modulating TH and CREB activation in PC12 cells.