• YAKHAK HOEJI
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• v.45 no.5
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• pp.522-528
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• 2001

Tyrosinase plays an important role in the process of melanin biosynthesis, and it is a biochemical target enzyme for skin-whitening agents and the remedy for disturbances in pigmentation. We have screened 25 natural plant extracts for inhibitory effects against DOPA oxidase activity of tyrosinase. For the inhibitory effect against DOPA oxidase activity of tyrosinase, the recombinant human tyrosinase and the purified mushroom tyrosinase were used. Each of the dried plants extracted with methanol, and then the extracts were subjected to sequential fractionations with methylene chloride, ethyl acetate, n-butanol and water, respective The methylene chloride fractions of Angelica tenuissima, Nardostachys chinensis, Bombyx mop and Saposhnikovia divaricata, and the n-butanol fraction of Bombyx mori notably inhibited the human tyrosinase activity as well as mushroom tyrosinase activity (more than 90% inhibition). This study suggests that the above extracts have a potential as whitening agents as single ingredients or in combination with other of the extracts.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.139.1-139.1
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• 2003

The effects of liriodenine, an aporphine isoquinoline alkaloid, on dopamine biosynthesis and L-DOPA-induced neurotoxicity in PC12 cells were investigated. Treatment of PC12 cells with liriodenine at 10 $\mu\textrm{M}$ showed 33.6％ inhibition of dopamine content decreased at 3 h and reached a minimal level at 12 h after the exposure to liriodenine at 10 $\mu\textrm{M}$. (omitted)

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.85.2-85.2
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• 2003

In vivo aromatic ${\beta}$-carbolines, such as harman and norharman, may easily be formed by cyclization of indoleamines with e.g. aldehydes. Because of the structural similarity to MPTP, ${\beta}$-carbolines have been proposed as endogenous toxins. In this study, we have investigated the effects of harman and norharman on dopamine biosynthesis and L-DOPA-induced cytotoxicity in PC12 cells. Treatment of PC12 cells with harman and norharman showed 48.8% and 49.5% inhibition of dopamine content at a concentration of 20 ${\mu}$M and 100 ${\mu}$M for 48h. (omitted)

• Proceedings of the KSLP Conference
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• 2015.03a
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• pp.18-18
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• 2015

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2001.10b
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• pp.113-113
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• 2001

• Journal of Ginseng Research
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• v.30 no.4
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• pp.188-193
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• 2006

We induced the activation of melanocytes in the epidermis of C57BL/6 mice by ultraviolet B (UVB) irradiation and observed the effect of red ginseng (RG) on the formation, and decrease of UVB-induced epidermal mel-anocytes. C57BL/6 mice were irradiated by UVB $80mJ/cm^2$ (0.5 mW/sec) daily for 7 days, and RG was intraperitoneally or topically applied pre- or post-irradiation. For the estimation of change of epidermal melanocytes, light microscopic observation with dihydroxyphenylalanine (DOPA) stain was performed. Split epidermal sheets prepared from the ear of untreated mice exhibited 11-16 $melanocytes/mm^2$, and one week after UV irradiation, the applied areas show an increased number of strongly DOPA-positive melanocytes with stout dendrites. But intraperitoneal or topical treatment with RG before each irradiation interrupted UVB-induced pigmentation and resulted in a marked reduction in the number of epidermal melanocytes as compared to radiation control skin. The number and size of DOPA-positive epidermal mel-anocytes were also significantly decreased in intraperitoneally injected or topically applicated group after irradiation with RG at 3rd and 6th weeks after irradiation. The present study suggests the RG as inhibitor of UVB-induced pigmentation and depigmenting agent.

• Animal Bioscience
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• v.36 no.6
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• pp.840-850
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• 2023

Objective: This study aimed to investigate the polymorphisms of the dopa decarboxylase (DDC) gene and association analysis with lamb quality and expression quantification of the DDC gene in phenotypically divergent Indonesian sheep. Methods: The totals of 189 rams with an average body weight of 24.12 kg at 10 to 12 months were used to identify DDC gene polymorphism using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Among 189 rams, several rams representing various sheep genotypes were used for an association study between genotypes and phenotypic traits with proc general linear model (GLM) analysis. In addition, the gene expression analysis of the DDC mRNA in the phenotypically divergent sheep population was analyzed using quantitative reverse-transcription PCR. Results: The DDC gene (g. 5377439 G>A) showed polymorphisms that indicated three genotypes: AA, AG, and GG. The DDC gene polymorphism was significantly associated (p≤0.05) with carcass characteristics including carcass percentage, carcass length, hot and cold carcass; physical properties of lamb quality including pH value; retail cut carcass; fatty acid composition such as fat content, pentadecanoic acid (C15:0), tricosylic acid (C23:0), lignoceric acid (C24:0), oleic acid (C18:1n9c), elaidic acid (C18:1n9t), nervonic acid (C24:1), linoleic acid (C18:2n6c), arachidonic acid (C20:4n6), cervonic acid (C22:6n3); and mineral content including potassium (K). The GG genotype of the DDC gene had the best association with lamb quality traits. The DDC gene expression analysis mRNA showed no significant difference (p≥0.05) between lamb quality traits. Conclusion: The DDC gene could be used as a potential candidate gene to improve lamb quality.

• Microbiology and Biotechnology Letters
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• v.24 no.1
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• pp.44-49
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• 1996

By using the ${\beta}$-tyrosinase of Citrobacter freundii KCT2006, which was cloned and overexpressed in Escherichia coli, 3,4-dihydroxy phenyl-L-alanine (L-DOPA) was synthesized efficiently from pyrocatechol, sodium pyruvate, and ammonium acetate. Optimal temperature and pH for the reaction were determined to be about 18$^{\circ}C$ and 8.5, respectively. The effects of substrate concentrations were also examined at different concentrations of ammonium acetate, sodium pyruvate, and pyrocatechol. Ammoniumacetate and sodium pyruvate increased the reaction rate until the concentrations reached to 300mM and 50mM, respectively. Although pyrocatechol showed the optimal concentration at 20mM, it was controlled between 20mM and 50mM to avoid the depletion of substrate during the enzymatic synthesis. Meanwhile the synthetic rate was improved about 20% when ethanol was included in the reaction solution. Based on above results, a reaction medium for the productin of L-DOPA was prepared and incubated with 1 unit/ml of ${\beta}$-tyrosinase. Pyrocatechol and sodium pyruvate was added to the reaction solutin intermittently to avoid the substrate depletion during the enzymatic reaction. After 24 hour of reaction, 31.6g/l of L-DOPA was accumulated in the reaction solution as soluble and precipitated ones and the conversion yield was about 85.2%.

• The Korean Journal of Pharmacology
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• v.23 no.2
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• pp.95-100
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• 1987

The effects of various drugs on muricide and hyperirritability induced by bilateral lesions of the nucleus accumbens septi (NAB) were investigated in comparison with those on aggression induced by midbrain raphe nuclei-lesioned rats (raphe) and olfactory bulbectomized rats (OB). Muricide in NAB, raphe and OB rats were markedly suppressed by atropine. Muricide in NAB and raphe rats were significantly suppressed by L-DOPA, L-5-HTP, but muricide in OB rats was scarcely suppressed by L-DOPA and L-5-HTP. Hyperirritability in NAB, raphe and OB rats were significantly reduced by L-DOPA and haloperidol but not suppressed by atropine. On the other hand, muricide in NAB rats was markedly suppressed by antidepressants, particularily, nomifensine, clomipramine and desipramine. Muricide in raphe rats was markedly inhibited by nomifensine and clomipramine but only slightly inhibited by desipramine. Muricide in OB rats was markedly suppressed by imipramine. Hyperirritability in NAB, raphe and OB rats were slightly suppressed by antidepressants. These results suggested that the pharmacological characteristics of aggression induced by NAB rats resembles that induced by raphe rats, but differs from that induced by OB rats. It is also suggested that employment of different types of experimentally induced muricide in rats can be useful for the evaluation of antidepressants.

• Journal of Life Science
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• v.29 no.4
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• pp.461-469
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• 2019

The aim of this study was to investigate the effect of a mixture of ethanol extracts of Black oryzasativa, Sesamum indicum, Oryza sativa, Rhynchosia Nulubilis, and Polygoni multiflori radix (MIXEE) on melanogenesis to develop a natural product for black hair growth. An accumulation of hydrogen peroxide ($H_2O_2$) in hair follicles, which reduces melanin synthesis, is responsible for hair graying. In the present study, MIXEE showed scavenging activity against DPPH radicals and reducing power. In addition, it reduced the cellular $H_2O_2$ level, indicating that it could inhibit oxidation and promote melanin synthesis, which was decreased by $H_2O_2$. On the other hand, it did not affect tyrosinase activity in vitro but promoted the turnover of L-DOPA into melanin. MIXEE promoted melanin synthesis at the cellular level in B16F1 cells. Furthermore, MIXEE increased the expression levels of superoxide dismutase 2 (SOD2) and SOD3 in western blot analysis. In addition, MIXEE increased the expression levels of tyrosinase-related protein (TRP)-2, which promoted melanin synthesis from L-DOPA. The results suggested that MIXEE could promote melanogenesis. Therefore, MIXEE may have potential as a natural product for promotion of melanin production and reversal of gray hair to black hair.