• Bulletin of the Korean Chemical Society
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• v.28 no.1
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• pp.77-80
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• 2007

As neurofilament proteins are major cytoskeletal components of neuron, abnormality of neurofilament is proposed in brain with neurodegenerative disorders such as Parkinson's disease (PD). Since oxidative stress might play a critical role in altering normal brain proteins, we investigated the oxidative modification of neurofilament-L (NF-L) induced by the reaction of cytochrome c with H2O2. When NF-L was incubated with cytochrome c and H2O2, the protein aggregation was increased in cytochrome c and H2O2 concentrationsdependent manner. Radical scavengers, azide, formate and N-acetyl cysteine, prevented the aggregation of NFL induced by the cytochrome c/H2O2 system. The formations of carbonyl group and dityrosine were obtained in cytochrome c/H2O2-mediated NF-L aggregates. Iron specific chelator, desferoxamine, prevented the cytochrome c/H2O2 system-mediated NF-L aggregation. These results suggest that the cytochrome c/H2O2 system may be related to abnormal aggregation of NF-L which may be involved in the pathogenesis of PD and related disorders.

• The Journal of Korean Medicine
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• v.20 no.4
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• pp.3-10
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• 2000

In order to elucidate the toxic mechanism of neurotoxical damage and neuroprotective effect of Jangwon-hwan(Zhuangyuan-wan) water extract, this experiment was performed. Neurotoxic effects of xanthine oxidase/hypoxanthine(XO/HX) were examined by MTT and NR assay, neuroprotective effects of Jangwon-hwan(Zhuangyuan-wan) water extract were examined by neurofilament enzymeimmuno assay(EIA). XO/HX induced an increase in cell viability, and a decrease in the amount of neurofilament on cultured mouse cerebral cortical neurons in dose-dependent manner. In neuroprotective effect of herb medicine, Jangwon-hwan(Zhuangyuan-wan) water extract increased the amount of neurofilament on cultured mouse cerebral cortical neurons damaged by XO/HX. From the results, it is suggested that XO/HX showed toxic effect in cultured mouse cerebral cortical Neurons and Jangwon-hwan(Zhuangyuan-wan) water extract is very effective in the prevention of neurotoxicity induced by XO/HX.

• Bulletin of the Korean Chemical Society
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• v.33 no.2
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• pp.731-734
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• 2012

• BMB Reports
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• v.45 no.2
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• pp.114-119
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• 2012

Salsolinol (1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline) is a compound derived from dopamine metabolism and is capable of causing dopaminergic neurodegeneration. Oxidative modification of neurofilament proteins has been implicated in the pathogenesis of neurodegenerative disorders. In this study, oxidative modification of neurofilament-L (NF-L) by salsolinol and the inhibitory effects of histidyl dipeptides on NF-L modification were investigated. When NF-L was incubated with 0.5 mM salsolinol, the aggregation of protein was increased in a time-dependent manner. We also found that the generation of hydroxyl radicals (${\bullet}OH$) was linear with respect to the concentrations of salsolinol as a function of incubation time. NF-L exposure to salsolinol produced losses of glutamate, lysine and proline residues. These results suggest that the aggregation of NF-L by salsolinol may be due to oxidative damage resulting from free radicals. Carnosine, histidyl dipeptide, is involved in many cellular defense processes, including free radical detoxification. Carnosine, and anserine were shown to significantly prevent salsolinol-mediated NF-L aggregation. Both compounds also inhibited the generation of ${\bullet}OH$ induced by salsolinol. The results indicated that carnosine and related compounds may prevent salsolinol-mediated NF-L modification via free radical scavenging.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.4
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• pp.1022-1026
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• 2005

To clarify the toxic effect on cultured neonatal mouse cerebral neurons damaged by ischemia, we examined the cytotoxicity induced by ischemia and the protective effect of antioxidant and AMPA/kainate receptor antagonist against ischemia-induced cytotoxicity on cultured cerebral neurons. For this study, mice were administrated with 20ug/kg cyclothiazide or 50U/kg vitamin E via intraperitoneal injection for 2 hours before ischemic induction. After cell culture for 7 days, cell viability, amount of neurofilament and protein kinase C activity were examined. Ischemia decreased significantly cell viability, amount of neurofilament and the increase of protein kinase C activity in these cultures. In the protective effect, vitamin I showed remarkably the increase of cell viability and amount of neurofilament, and the decrease of protein kinase C activity but, cyclothiazide did not showed any protective effect on ischemia-induced cytotoxicity. From these results, it is suggested that vitamin I is effective in blocking the neurotoxicity induced by ischemia, but cyclothiazide as a AMPA/kainate receptor antagonist is not.

• BMB Reports
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• v.36 no.5
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• pp.488-492
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• 2003

Neurofilament-L (NF-L) is a major element of neuronal cytoskeletons and known to be important for neuronal survival in vivo. Since oxidative stress might play a critical role in the pathogenesis of neurodegenerative diseases, we investigated the role of copper and peroxide in the modification of NF-L. When disassembled NF-L was incubated with copper ion and hydrogen peroxide, then the aggregation of protein was proportional to copper and hydrogen peroxide concentrations. Dityrosine crosslink formation was obtained in copper-mediated NF-L aggregates. The copper-mediated modification of NF-L was significantly inhibited by thiol antioxidants, N-acetylcysteine, glutathione, and thiourea. A thioflavin-T binding assay was performed to determine whether the copper/$H_2O_2$ system-induced in vitro aggregation of NF-L displays amyloid-like characteristics. The aggregate of NF-L displayed thioflavin T reactivity, which was reminiscent of amyloid. This study suggests that copper-mediated NF-L modification might be closely related to oxidative reactions which may play a critical role in neurodegenerative diseases.

• Bulletin of the Korean Chemical Society
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• v.32 no.9
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• pp.3421-3424
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• 2011

The endogenous neurotoxin, 1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline (salsolinol), has been considered a potential causative factor for the pathogenesis of Parkinson's disease (PD). In this study, we examined oxidative modification of neurofilament-L (NF-L) induced by salsolinol. When disassembled NF-L was incubated with salsolinol, the aggregation of protein was increased with the concentration of sasolinol. The formation of carbonyl compound was obtained in salsolinol-mediated NF-L aggregates. This process was protected by free radical scavengers, such as N-acetyl-L-cysteine and glutathione. These results suggest that the aggregation of NF-L is mediated by salsolinol via the generation of free radicals. We also investigated the effects of copper ion on salsolinol-mediated NF-L modification. In the presence of copper ions, salsolinol enhanced the modification of NF-L. We suggest that salsolinol might be related to abnormal aggregation of NF-L which may be involved in the pathogenesis of neurodegenerative diseases and related disorders.

• Bulletin of the Korean Chemical Society
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• v.29 no.9
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• pp.1732-1736
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• 2008

The endogenous dipeptides, carnosine and related compounds, are the naturally occurring dipeptides with multiple neuroprotective properties. We have examined the protective effects of carnosine, homocarnosine and anserine on the aggregation of neurofilament-L (NF-L) induced by neurotoxin, acrolein. When NF-L was incubated with acrolein in the presence of carnosine, homocarnosine or anserine, protein aggregation was inhibited in a concentration-dependent manner. These compounds inhibited the formation of protein carbonyl compounds and dityrosine in acrolein-mediated NF-L aggregates. The aggregates of NF-L displayed thioflavin T reactivity, reminiscent of amyloid. This thioflavin T reactivity was inhibited by carnosine and related compounds. This effect was associated with decreased formation of oxidatively modified proteins. Our results suggested that carnosine and related compounds might have protective effects to brain proteins under pathophysiological conditions leading to degenerative damage such as neurodegenerative disorders.

• BMB Reports
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• v.40 no.1
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• pp.125-129
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• 2007

Neurofilament-L (NF-L) is a major element of the neuronal cytoskeleton and is essential for neuronal survival. Moreover, abnormalities in NF-L result in neurodegenerative disorders. Carnosine and the related endogeneous histidine dipeptides prevent protein modifications such as oxidation and glycation. In the present study, we investigated whether histidine dipeptides, carnosine, homocarnosine, or anserine protect NF-L against oxidative modification during reaction between cytochrome c and $H_2O_2$. Carnosine, homocarnosine and anserine all prevented cytochrome c/$H_2O_2$-mediated NF-L aggregation. In addition, these compounds also effectively inhibited the formation of dityrosine, and this inhibition was found to be associated with the reduced formations of oxidatively modified proteins. Our results suggest that carnosine and histidine dipeptides have antioxidant effects on brain proteins under pathophysiological conditions leading to degenerative damage, such as, those caused by neurodegenerative disorders.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.2
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• pp.374-379
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• 2003

To evaluate the mechanism of oxidative damage by Xanthine oxidase(XO) and hypoxanthine(HX)-induced oxygen radicals, XTT assay was carried out. Neurofilament EIA and PKC activity were measured to evaluate the protective effect of Jingansikpung-tang(JST) and Gamijingansikpung-tang(GJST) water extract on cultured spinal sensory neurons damaged by XO/HX, after the cultured mouse spinal sensory neurons were preincubated with various concentrations of JST and GJST water extract for 3 hours prior to exposure of XO/HX. The results were XO/HX decreased significantly, in proportion to concentration and exposed time, the survival rate of the cultured mouse sensory neurons on XTT assay. And in proportion to concentration and exposed time on cultured spinal sensory neurons, XO/HX showed the quantitative decrease of neurofilament by EIA, increase of PKC activity, but JST and GJST showed the neuroprotective effects against decrease of neurofilament and increase of PKC activity by XO/HX. From the above results, it is concluded that XO/HX have a neurotoxic effect on cultured spinal sensory neurons and the herbs water extract, such as JST and GJST prevent the toxicity of XO/HX effectively.