• Biomedical Science Letters
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• v.15 no.4
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• pp.287-293
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• 2009

Phospholipase D (PLD) is an enzyme hydrolyzing phosphatidylcholine to phosphatidic acid (PA) and choline. We investigated the involvement of PLD1 in the uptake of norepinephrine (NE) in PC12 cells, pheochromocytoma cells. NE uptake was specific in PC12 cells because nomifensine, a specific blocker of NE transporter, blocked NE uptake. Inhibition of PLD function in PC12 cells by the treatment of butanol suppressed the NE uptake. In contrast, overexpression of PLD1 in PC12 cells increased NE uptake efficiently. These results suggest that PLD activity is involved in NE uptake. We explored the action mechanism of PLD in NE uptake. PA phosphatase inhibitor, propranolol, blocks the formation of PKC activator diacylglycerol from PA. Propranolol treatment to PC12 cells blocked dramatically the uptake of NE. Specific PKC inhibitors, GF109203X and Ro31-8220, blocked NE uptake. Taken together, we suggest for the first time that PLD1 activity is involved in NE uptake via the activation of PKC.

• YAKHAK HOEJI
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• v.47 no.4
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• pp.230-233
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• 2003

Previously, protoberberine alkaloids such as berberine and palmatine have been found to lower dopamine content in PC12 cells (Shin et at., 2000). In this study, the effects of berberine and palmatine on L-DOPA-induced increase in dopamine level and cytotoxicity in PC12 cells were investigated. Treatment of PC12 with L-DOPA at concentration ranges of 20∼50 $\mu$M increased dopamine content and the increase in dopamine levels by L-DOPA was inhibited by 10∼40 $\mu$M berberine and 10∼80 $\mu$M palmatine, which the concentration ranges did not show a cytotoxicity. However, berberine and palmatine at concentrations higher than 50 $\mu$M and 100 $\mu$M caused a cytotoxicity, respectively. In addition, berberine (10∼20 $\mu$M) and palmatine (10∼50 $\mu$M) at non-cytotoxic concentration ranges aggravated L-DOPA-induced cytotoxicity in PC12 cells (L-DOPA concentration ranges, 20∼50 $\mu$M). The L-DOPA-induced cytotoxicity was also significantly potentiated by berberine (50 $\mu$M) and palmatine (100 $\mu$M) with cytotoxic ranges. These data demonstrate that berberine and palmatine inhibit L-DOPA-induced increase in dopamine content and stimulate L-DOPA-induced neurotoxicity. Therefore, the possibility that the long-term L-DOPA treated patients with berberine and palmatine could be checked the adverse symptoms.

• Korean Journal of Pharmacognosy
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• v.26 no.1
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• pp.57-61
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• 1995

MeOH extracts of eight herbal medicines were investigated for the effects on catecholamine biosynthesis and tyrosine hydroxylase (TH) activity in PC12 cells. Among them, the MeOH extracts of Polygalae Radix and Rehmaniae Radix showed 32 and 22% inhibition on the dopamine biosynthesis, respectively at a concentration of $40{\mu}g/ml$ medium. But, the TH activity was reduced by the treatment of Polygalae Radix. These results suggest that Polygalae Radix has an inhibitory effect on the catecholamine biosynthesis by the reduction of TH activity in PC12 cells.

• Korean Journal of Oriental Medicine
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• v.5 no.1
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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.

• YAKHAK HOEJI
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• v.50 no.2
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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.

• Natural Product Sciences
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• v.20 no.4
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• pp.296-300
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• 2014

The present study investigated the effects of (-)-sesamin on dopamine biosynthesis in PC12 cells. Treatment with (-)-sesamin (25 and $50{\mu}M$) increased intracellular dopamine levels and enhanced L-DOPA-induced increase in dopamine levels in PC12 cells. (-)-Sesamin (25 and $50{\mu}M$) also induced the phosphorylation of cyclic AMP-dependent kinase A (PKA), cyclic AMP-response element binding protein (CREB) and tyrosine hydroxylase (TH) in PC12 cells. These results suggest that (-)-sesamin induces dopamine biosynthesis via the PKA-CREB-TH pathways in PC12 cells. (-)-Sesamin needs to be studied further to serve as an adjuvant phytonutrient in neurodegenerative disease.

• Korean Journal of Pharmacognosy
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• v.34 no.3 s.134
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• pp.242-245
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• 2003

The effects of chelidonine, a benzophenanthridine isoquinoline alkaloid, on L-DOPA-induced cytotoxicity in PC12 cells were investigated. The treatment of PC12 cells with chelidonine $(1-4\;{\mu}M)$ decreased dopamine content in a dose-dependent manner (30.2% inhibition at $4\;{\mu}M)$. Chelidonine was not cytotoxic up to $4\;{\mu}M)$. However, chelidonine at concentrations higher than $5\;{\mu}M$ caused a cytotoxicity in PC12 cells. L-DOPA at concentrations higher than $50\;{\mu}M$ led to cell damage by oxidative stress in PC12 cells. Chelidonine at non-cytotoxic concentration ranges of $1-4{\mu}M$ aggravated L- DOPA $(20-50\;{\mu}M)$-induced cytotoxicity in PC12 cells. The L-DOPA-induced cytotocxicity was synergistically stimulated by chelidonine at concentrations grader than $5\;{\mu}M$. These data demonstrate that chelidonine exacerbates L-DOPA-induced cytotoxicity. Therefore, it is proposed that the long-term L-DOPA therapeutic patients with chelidonine may need to be checked for the adverse symptoms.

• The Journal of Internal Korean Medicine
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• v.30 no.1
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• pp.51-63
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• 2009

Background and Objective : The prospects for developing an anti-apoptotic natural component or a compound that exerts a neuroprotective effect with few or no side effects for the treatment of neurodegenerative disease appear favorable. In the present study, we evaluated the effects of the methanol extract of Phellodendri Cortex (PC extract) on 1-methyl-4-phenyl pyridinium($MPP^+$)-induced apoptosis in PC-12 cells. Materials and Methods : We used the methanol extract of Phellodendri Cortex (PC extract). PC-12 cells were cultured by RPMZ-1640. We found the PC extract's gene expression (Bax, Bcl-2) by using RT-PCR. We examined the PC extract's protein expression (Bcl-2, Bax, cytochrome c, poly (ADP-ribose) polymerase (PARP), caspase-3) by SDS-PAGE and Western blot. Results : Apoptosis in $MPP^+$-induced PC-12 cells was accompanied by an increased Bax/Bcl-2 ratio, release of cytochrome c to the cytosol and the activation of caspase-3. PC extract inhibited the down-regulation of Bcl-2 and the up-regulation of Bax, as well as the release of mitochondrial cytochrome c into the cytosol. In addition, PC extract attenuated caspase-3 activation and cleavage of poly (ADP-ribose) polymerase (PARP). Conclusion : These results suggest that the neuroprotective potentials of PC extract against $MPP^+$-induced apoptosis can be. at least partially, ascribed to its anti-apoptotic effects in PC-12 cells.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.6
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• pp.1462-1469
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• 2008

The purpose of the study was to confirm what effect HRHDT treatment had on cell extinction by damage of endoplasmic reticulum induced to PC-12 cell damage by glucose deprivation. The study confirmed what effect it had on forming the condition of glucose deprivation within a culture fluid of PC-12 cell and on a nerve cell's survival rates and tested whether HRHDT could prevent extinction of PC-12 cell by glucose deprivation. Also, the study confirmed what effect HRHDT treatment had on the emitted quantity of LDH by glucose deprivation. To examine PC-12 cell's behavioral change under the condition of glucose deprivation and a protective effect of HRHDT on the change, the study observed PC-12 cell's behavioral change with a microscope. Also, the study confirmed density of calcium ion within cells followed by a culture time in the condition of glucose deprivation with FACS and confirmed what effect HRHDT treatment had on the above density of calcium ion within cells. Finally, the study carried out the western blot and confirmed what effect HRHDT treatment had on revelation of GRP 78 and CHOP protein and a segmental type of aspase 12. In this study, HRHDT rescued PC-12 cells from glucose deprivation-induced cell death. HRHDT also prevents the LDH release, Ca++ accumulation, and morphological change, which was associated with the ER stress. Furthermore, HRHDT reduced the expression of ER chaperone (Grp78 and CHOP) proteins by glucose deprivation in PC-12 cells. These results suggest that HRHDT might provide a useful therapeutic strategy in treatment of the neurodegenerative diseases caused by glucose deprivation injuries.

• Molecules and Cells
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• v.22 no.3
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• pp.291-299
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• 2006

Vitexin, a natural flavonoid compound identified as apigenin-8-C-${\beta}$-D-glucopyranoside, has been reported to exhibit antioxidative and anti-inflammatory properties. In this study, we investigated its effect on hypoxiainducible factor-$1{\alpha}$ (HIF-$1{\alpha}$) in rat pheochromacytoma (PC12), human osteosarcoma (HOS) and human hepatoma (HepG2) cells. Vitexin inhibited HIF-$1{\alpha}$ in PC12 cells, but not in HOS or HepG2 cells. In addition, it diminished the mRNA levels of hypoxia-inducible genes such as vascular endothelial growth factor (VEGF), smad3, aldolase A, enolase 1, and collagen type III in the PC12 cells. We found that vitexin inhibited the migration of PC12 cells as well as their invasion rates, and it also inhibited tube formation by human umbilical vein endothelium cells (HUVECs). Interestingly, vitexin inhibited the hypoxia-induced activation of c-jun N-terminal kinase (JNK), but not of extracellular-signal regulated protein kinase (ERK), implying that it acts in part via the JNK pathway. Overall, these results suggest the potential use of vitexin as a treatment for diseases such as cancer.