• Bulletin of Food Technology
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• v.12 no.2
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• pp.26-38
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• 1999

조리가공 중 생성되는 주요 발암성 이환방향족아민(heterocyclic aromatic amine)인 Trp-P-1 및 Trp-P-2가 human 및 rat keratinocytes에 대해 나타내는 세포 독성을 colony expansion법의 의해 조사, 비교하였다. 특히 Trp-P-2는 human keratinocytes에 대해서는 독성을 나타내지 않은데 반해 rat keratinocytes(계대수 2-5)에 대해서는 독성을 나타내는 선택성을 나타내었다. 이러한 Trp-P-2의 종(species)간 독성감수성 차이가 대사 효소계 활성이나 mutagenic activation상의 차이에 기인되는지를 살펴본 결과, CYP4501As 및 독성감수성 차이가 크게 나타났던 human 및 rat keratinocytes의 microsome에서 거의 같았다. 이와 같은 결과는 CYP4501A1 및 CYP1B1의 mRNA의 발현정도를 northernblot에 의해 살펴보았던 결과에서도 일치하였다. 반면 Trp-P-2의 대사활성화 및 해독화에 관여하는 효소인 N.O-acetyltransferase(NAT)활성은 rat keratinocytes보다 human keratinocytes에서 높았다. 일반적으로 독성물질의 해독화에 관여하는 glutathione S-transferase(GST) 또한 rat keratinocytes보다 human keratinocytes에서 높게 나타났다. Trp-P-2가 mutagenic metabolite로 활성화되는 정도를 salmonella microsome microsuspension assay로 살펴본 결과, 독성 감수성 차이가 크게 나타났던 human 및 rat keratinocytes간의 활성은 비슷한 것으로 나타났다. DNA 및 단백질 adduct형성능의 경우, human 및 rat keratinocytes간 DNA adduct형성능에는 차이가 없었고, 단백질 adduct형성능의 경우만 Trp-P-2에 대한 독성감수성 정도가 컸던 rat keratinocytes가 다른 세포들에 비해 크게 나타났다. 이상의 결과를 종합해 볼 때, CYP1A- 또는 CYP1B1-관련 마이크로솜 효소활성이나 mutagenic activation은 human 및 rat keratinocytes간에 나타났던 독성 감수성의 차이를 설명할 수 없으며, 해독화에 관여하는 효소활성이 종간 관찰되었던 독성 감수성의 차이에 더 중요한 역할을 하는 것으로 보인다.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.2
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• pp.69-77
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• 2007

We examined the depigmentation effect on Korean traditional citrus 17 species. With B16 melanoma cells, we have seen inhibition of the tyrosinase and melanin formation, which eventually were dose dependently decreased by three citrus fruits, immature Citrus unshiu, Citrus hassaku, and Citrus sinensis ${\times}$ reticulata as compared with positive control. Also, we examined expression of tyrosinase, DOPAchrome tautomerase (TRP-2), and DHICA oxidase (TRP-1) which affect melanin synthesis. Especially, immature Citrus unshiu decreased the protein levels of tyrosinase and TRP-1. In conclusion, immature Citrus unshue showed the strongest activity in all the experiments mentioned above and we expect that it can be used for preventing UV-induced pigmentation.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.2
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• pp.247-253
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• 2002

Two experiments were conducted to investigate the impact of high temperature and dietary tryptophan (Trp) on performance, selected organ weights and plasma free amino acid (AA) concentrations in broiler chickens. In Experiment 1, exposure to $27-33^{\circ}C$ of chickens for 2 weeks from 2 weeks of age did not affect growth and plasma free AA concentration except for a decrease in the concentration of plasma tyrosine (Tyr). In Experiment 2, 2-week-old birds were allocated to one of three temperature treatments; $24^{\circ}C$ (control), $36^{\circ}C$ (heat stress, HS) and $24^{\circ}C$ pair-fed (24PF) for 2 weeks and fed on diets containing 50, 100 and 300% of NRC requirement for Trp. Heat stress caused a reduction of weight gain and feed intake irrespective of dietary Trp levels compared with control counterparts, while feeding of 300% Trp diet did not attenuate the reduced performance by HS exposure. In groups fed the 100% Trp diets, plasma aromatic AA (AAA) and Tyr concentrations were decreased in the HS birds compared with the 24PF group. Plasma concentrations in most of AA groups were increased by HS in chickens fed the 50% Trp diet, while those were not changed by HS in chickens fed the 300% Trp diet, compared with 24PF counterparts. The plasma Trp/LNAA (LNAA=large neutral AAs, which are comprised of BCAA, AAA and Trp) ratio was increased by HS in chickens fed the 100% Trp diet, while it was decreased in chickens fed on 50% Trp diet as compared with 24PF group. From these results, it is suggested that performance and plasma amino acid profile deranged by heat stress are modulated, at least, to be relieved from the heat stress by feeding 50% Trp diet but not at all by feeding 300% Trp diet. The involvement of altered plasma AA profiles, in particular plasma Tyr concentrations and Trp/LNAA ratio, is discussed in association with the performance characteristics of HS chickens.

• Journal of Photoscience
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• v.9 no.2
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• pp.114-117
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• 2002

Ultraviolet resonance Raman (UVRR) spectroscopy was used to elucidate the dynamic change of the protein structure of bacteriorhodopsin (BR) during the photocycle. The photointermediates minus light- adapted (LA) BR difference spectra show Trp difference signals, which are assigned to Trp189 or Trp182 on helix F by using the mutants, W182F and W189F. The Difference signals of Trp 182 indicates an increase in hydrogen bonding strength at the indole nitrogen and a large change in the side chain conformation (X$\^$2,1/ torsion angle) in the M$_1$ \longrightarrow M$_2$ transition. On the other hand, Trp189 shows an increased hydrophobic interaction. These results suggest that the tilt of helix F occurs in the M$_1$\longrightarrow M$_2$ transition. In the M$_2$ \longrightarrow N transition, the hydrophobic interaction of Trp182 decreases drastically, The decrease in hydrophobic interaction of Trp182 in the N state suggests an invasion of water molecules that promote the proton transfer from Asp96 to the Schiff base. Structural reorganization of the protein after the tilt of helix F may be important for efficient reprotonation of the Schiff base.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.48 no.1
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• pp.11-24
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• 2022

It has been reported that the ethanolic extract of the root of Piper methysticum (P. methysticum) inhibits melanogenesis in melanocyte stimulating hormone (MSH)-activated B16 melanoma cells. Flavokawain B (FKB) and Flavokawain C (FKC) isolated from this extract have been found to inhibit melanin production based on anti-melanogenesis activity. This study was designed to find out the inhibition and its process of FKB and FKC on melanin synthesis in melan-a melanocytes. FKB and FKC inhibited melanogenesis at 10 μM, 5 μM respectively in melan-a melanocytes. However, they did not inhibit extracellular tyrosinase activity from melan-a melanocytes. FKB reduced the protein level of tyrosinase (Tyr), tyrosinase-related protein 1 (TRP-1), tyrosinase-related protein 2 (TRP-2), microphthalmia-associated transcription factor (MITF) and the mRNA level of Tyr and TRP-1. FKC reduced the protein level of TRP-2 and MITF and the mRNA level of TRP-1 and Tyr. The reduced expression of Tyr and TRP-1 might be resulted from the decreased MITF which regulates major melanogenic proteins. However, since the mRNA expression of MITF did not change by FKB and FKC treatment, the effects of FKB and FKC on extracellular signal regulating kinase (ERK)/AKT phosphorylation, known to regulate the degradation of MITF, were confirmed. FKB and FKC significantly increased the phosphorylation of ERK1/2, not in AKT. These results suggest that FKB and FKC may be helpful as a potential depigmenting agent for various hyper-pigmentary disorders.

• Journal of Life Science
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• v.27 no.5
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• pp.536-544
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• 2017

Abeliophyllum distichum Nakai is deciduous shrubs of flowering plant in Oleaceae. It is important plant resources and consists of one species in the world. Also the endemic plant of A. distichum has been protected and designed endangered plant in Korea. For this reason, study on the immature seeds of A. distichum (ADS) hasn't progressed. In the present study, we evaluated the antioxidant activity and inhibitory effects on proteins and mRNA levels were related in the whitening effect in B16F10 cells. ADS was effective for reaction oxygen species (ROS). ROS causes various diseases such as aging, inflammation, cancer, and etc. Antioxidant properties were evaluated DPPH, ABTS radical scavenging activity and Reducing power. Plants were known that contained phenolic compounds were related in antioxidant activity. Phenolic compounds were phytochemicals commonly named natural polyphenols. These are secondary metabolites of plants involved in the defense against different types of stresses. In results, ADS suppressed the expression and transcription of Tyrosinase, TRP-1, TRP-2, and Microphthalmia-associated transcription factor (MITF). Tyrosinase, tyrosinase-related protein 1 (TRP-1), tyrosinase-related protein 1 (TRP-2) are known to play an important role in melanin biosynthesis. MITF regulated the expression and transcription of Tyrosinase, TRP-1, and TRP-2. In conclusion, ADS was effective in both antioxidant activities and whitening effects. Also, they were associated with the content of phenolic compounds. We suggested that ADS can be use antioxidants and skin-whitening functional cosmetics material derived from natural plant resources.

• Korean Journal of Microbiology
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• v.23 no.1
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• pp.9-12
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• 1985

As a part of the host cell development for a amplified recombinant trp operon, $aroP^-$ mutation was introduced in a E. coli host strain. $aroP^-$ mutation was induced by transposon Tn10 and transduced into the E. coli host cell by bacteriophage P1Kc. The effect of $aroP^-$ mutation on the excretion of tryptophan in E. coli $trpR^{-ts}/ColE_1 -trp^+$ cells was investigated. Mutant lacking the general aromatic transport system was resistant to ${\beta}-2-thienylalanine\;(2{\times}10^{-4}\;M)$, p-fluorophenylalanine $(2{\times}10^{-4}M)$, or 5-methyltryptophan $(2{\times}10^{-4}\;M.)[^3H]-tryptophan$ uptake of the $aroP^-$ mutant strain was reduced considerably as compared with $aroP^+$ counterpart. The rate of $[^3H]-tryptophan$ uptake of the $aroP^-$ mutant strain treated with $NaN_3(3{\times}10^{-2}\;M)$ was much less affected than that of $aroP^+$ counterpart. The $aroP^-$ transductants increased the tryptophan excretion from E. coli $trpR^{-ts}/ColE_1 -trp^+$ four times more than $aroP^+$ counterpart.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.43 no.3
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• pp.231-237
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• 2017

This study was performed to cytotoxicity, tyrosinase inhibition activity, intracellular melanin contents to verify the whitening effect of fraction from Glycine soja Siebold et Zucc. (G. soja). Using western blotting, tyrosinase expression in B16F10 melanoma cells and expression levels of tyrosinase related protein-1 (TRP-1) and protein-2 (TRP-2) were examined. As a result, all of the fractions showed a high cell viability over 82% at the concentrations of 0.125, 0.25, 0.5, 2.0 mg/mL. When the whitening effects of fractions from G. soja were tested using B16F10 melanoma cells treated with the ${\alpha}$-melanocyte stimulating hormone (${\alpha}-MSH$), the EtOAc fractions inhibited tyrosinase and melanogenesis effectively. The result of protein expression measurement using western blot showed that TRP-1, TRP-2 and tyrosinase protein expression in B16F10 melanoma cells treated with extracts decreased. Therefore, it is concluded that the fractions from G. soja have whitening effect by inhibiting protein related melanogenesis.

• Korean Journal of Food Science and Technology
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• v.26 no.2
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• pp.188-194
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• 1994

The inhibitory effects of rice extract on mutagenicity induced by 3-amino-1,4-dimethyl-5H-pyrido [4,3-b]indole(Trp-P-1), 3-amino-1-methyl-5H-pyrido [4,3-b]indole(Trp-P-2), sodium azide(SA), 2-nitrofluorene(2NF), mitomycin C(MMC), aflatoxin $B_1(AFB_1)$ and 4-nitroquinoline oxide(4-NQO) were investigated using Salmonella typhimurium reversion assay, SOS chromotest and spore rec-assay. In Salmonella typhimurium reversion assay, methanol extract from brown rice (Illpumbyeo, Japonica variety) showed the highest inhibitory effect among other extracting solvent including hexane, chloroform and water. Methanol extract showed stronger inhibitory effect, above 85%, on indirect-acting mutagens(Trp-P-1, Trp-P-2 and $AFB_1$) than those on direct-acting mutagens(4-NQO, 2NF). In SOS chromotest, methanol extracts showed $77.6{\sim}88.9%$ effects on SOS function induced by Trp-P-1, Trp-P-2, $AFB_1$ and 4-NQO. In spore rec-assay, methanol extracts inhibited the mutagenicity induced by $AFB_1$ and MMC. As the concentration of methanol extract increased, inhibitory effect on mutagenicity increased but reached at steady state as inhibition rate of 90% when the concentration was above 5 mg/plate. In inhibitory effects of methanol extracts by various rice varieties, all of 11 varieties turned out to have inhibitory effect on mutagenicity. There was no significant difference (p>0.05) in inhibitory effect of methanol extracts between brown and white rice against Trp-P-1, but showed difference (p<0.05) against 4-NQO.

• Journal of Applied Biological Chemistry
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• v.58 no.3
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• pp.266-271
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• 2015

Recently many effort focused to understand the mechanical insights of melanogenesis to develop the agent for hyper-pigmentation. So this study was performed to investigate the depigmentation of Vitex rotundifolia. With B16F10 mouse melanoma cell, we have seen inhibition of the tyrosinase, MITF, TRP-1, TRP-2, and melanin synthesis, which eventually were dose dependently decreased by Vitex rotundifolia. Specially, Vitex rotundifolia decreased the protein levels of tyrosinase and TRP-1. In conclusion, Vitex rotundifolia showed the whitening activity in all the experiments mentioned above and we expect that it can be used for preventing melanin synthesis.