• Natural Product Sciences
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• v.17 no.1
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• pp.26-32
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• 2011

Novel tyrosinase inhibitors are important for pigmentation in the skin. Following extraction of tyrosinase inhibitors from edible vegetables or fruits, we found that the Prunus persica flesh extract (PPFE) exhibited potential inhibitory activity for melanogenesis. PPFE showed tyrosinase inhibitory activity in an enzymatic assay and PPFE also significantly inhibited the melanin formation in cultured mouse melan-a cells. Moreover, real-time RT-PCR analysis revealed that the inhibition of melanin production by PPFE was closely related to marked suppression of mRNA expression of tyrosinase and tyrosinase-related protein-1 and -2 (TRP-1 and TRP-2) in melan-a cells. Further investigation found that the modulation of tyrosinase expression by PPFE was associated with the transcriptional regulation of the microphthalmia-associated transcription factor (MITF). PPFE inhibited the promoter activity of MITF and suppressed MITF mRNA expression in melan-a cells. These results indicate that PPFE down-regulates melanogenesis-associated gene expression through MITF-mediated transcriptional regulation and these events might be related to the hypopigmentary effects of PPFE.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.22 no.2
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• pp.82-91
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• 2009

Objectives : The purpose of this study is to investigate whitening effects and anti-wrinkle effects of a few 80% ethanol extracted herbal medicines. Methods : In the first study, a few 80% ethanol extracted herbal medicines were screened for their inhibitory activities against the tyrosinase. In the second study, a few 80% ethanol extracted herbal medicines were screened for their inhibitory activities against elastase. Results : 1. We showed 28%, 27% and 19% inhibitions of mushroom tyrosinase at 500 $\mu$g/ml concentration of ASR, AIF and ABR extracts and they were showed higher anti-tyrosinase activity than arbutin's. We also could observe that the decreased mushroom tyrosinase activities in RR, CML, LR, AGR and TH extracts. 2. RR, AF and ABR (final concentrstion 1 mg/ml) were appeared 60%, 98%, 83% of inhibitions of elastase activity, and they were showed higher anti-elastase activity than that of ursolic acid. We also could observe that the decreased elastase activities in AIF, AR, LR and CML extracts. Conclusions : These results suggest that ASR, AIF and ABR extracts contribute to the anti-melanin activities and represent potential sources of whitening agent, and RR, AF and ABR extracts contribute to the anti-elastase activities and represent potential sources of anti-wrinkle agent. These results suggest that some herbal medicines could be strong potential sources of inhibition about anti-aging and whitening effects for the skin.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.9
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• pp.1191-1196
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• 2012

The purpose of this study was to investigate the tyrosinase, xanthine oxidase, angiotensin converting enzyme (ACE) inhibitory effects, and nitrite scavenging abilities of Jubak (alcohol filter cake, AFC) hot water and ethanol extracts. Tyrosinase inhibitory effects of Jubak hot water and ethanol extracts were above 85%. Nitrite scavenging ability was higher at pH 1.2 than at pH 4.2 and 6.0. Nitrite scavenging abilities of water and ethanol extracts were above 90% at pH 1.2. Xanthine oxidase inhibitory effect of Jubak hot water and ethanol extracts showed a lower, and the effect did not different by hot water and ethanol. ACE inhibitory effects of Jubak hot water and ethanol extracts were approximately 43~53% and 36~47%, respectively. Overall, our results indicate that Jubak hot water and ethanol extracts may have tyrosinase and ACE inhibitory effects and nitrite scavenging ability, but no xanthine oxidase inhibitory effect. Therefore, Jubak has potential as a cosmetic raw material. Additionally, Jubak could be used as a food additive.

• The Korean Journal of Mycology
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• v.43 no.2
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• pp.99-103
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• 2015

We prepared supernatants and cell-free extracts of yeasts isolated from wild flowers in Korea, and their antioxidant activity and inhibitory activities of xanthine oxidase and tyrosinase were investigated. Among them, cell-free extracts of Kuraishia capsulata UL40-2 and Sporobolomyces ruberrimus 121-Z-3 showed significantly high xanthine oxidase inhibitory activity of 46.4% and 48.3%, respectively. Starmerella bombicola 80-J-1 also showed tyrosinase inhibitory activity of 36.2% in the cell-free extract. Other antioxidant activities and tyrosinase inhibitory activities were not detected or were below 20%. Maximal production of the xanthine oxidase inhibitors were observed when Kuraishia capsulate UL40-2 and Sporobolomyces ruberrimus 121-Z-3 were cultured in the yeast extract-peptone-dextrose media at $30^{\circ}C$ for 24 hour, respectively.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.23 no.3
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• pp.115-121
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• 1997

To identify inhibitors of melanogenesis, we compared the effects of 5 compounds on mushroom tyrosinase, human melanocytic tyrosinase activity and melanin content. The cytotoxicyty of the components were also tested on cultured human melanoctes. Kojic acid showed marked inhibitory effect both on mushroom and human tyrosinase activity. This action of kijic acid is stronger than that of ascorbic acid. Arbutin inhibited human tyrosinase activity of cultured melanocytes although it had slightly inhibitory effect on mushroom tyrosinase activity. Azelaic acid had no effect on human tyrosinase activity. Melanin production was inhibited significantly by kojic acid and tranexamic acid. MTT assay showed that all of the compounds were non-cytotoxic to melanocytes at the concentrations tested. These results suggest that the effect of kojic acid on cultured meanocytes involve inhibition of tyrosinase activity and melanogenesis without affection the cell number.

• Journal of Microbiology and Biotechnology
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• v.16 no.12
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• pp.1977-1983
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• 2006

Kaempferol was isolated and identified from the methanol extract of the flowers of Impatiens balsamina. Kaempferol showed inhibitory activity against mushroom tyrosinase with an $ID_{50}$ of 0.042 mM. Inhibition kinetics, as determined using a Lineweaver-Burk plot, showed kaempferol to be a competitive inhibitor of mushroom tyrosinase with a $K_i$ value of 0.011 mM. The lag phase of tyrosine hydroxylation catalyzed by mushroom tyrosinase clearly increased on increasing the concentration of kaempferol. In addition to its tyrosinase inhibiting activity, kaempferol strongly inhibited melanin production by Streptomyces bikiniensis, in a dose-dependent manner, without inhibiting cell growth. For comparative purposes, the tyrosinase inhibitory activity of kaempferol was also assayed versus quercetin, a positive standard.

• YAKHAK HOEJI
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• v.41 no.4
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• pp.456-461
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• 1997

Tyrosinase is known to accelerate the melanin polymer biosynthesis in melanocyte, so tyrosinase inhibitors hinder the melanin polymer biosynthesis and are useful not only for th e material used in cosmetics as skin-whitening agents but also as the remedy for disturbances in pigmentation. During our search for new melanin biosynthesis inhibitors from natural sources, 130 higher plants were tested for the inhibitory effect against tyrosinase activity by the mushroom tyrosinase assay. Among them, Carex humilis ($IC_{50}$, 10vg/ml), Sophora flavescence ($IC_{50},\;20{\sim}50{mu}g/ml$) and Styrax japonica ($IC_{50},\;10{\mu}g/ml$) inhibited the tyrosinase activity strongly.

• Journal of Life Science
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• v.29 no.7
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• pp.755-761
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• 2019

Kojic acid (KA) is produced by Aspergillus oryzae-sort of like mushrooms, which is commonly called as koji in Japan. KA is used as a chelation agent and a preservative preventing oxidative browning of fruits. KA also shows antibacterial and antifungal properties. Because KA stops the production of melanin by inhibiting tyrosinase in the biosynthetic pathway from tyrosine to melanin in skin, it has been applied as a skin lightening ingredient in cosmetics. Since some animal studies have shown that high amounts of KA had side effects such as in liver, kidney, reproductive, cardiovascular, gastrointestinal, respiratory, brain, and nervous system, more efficient KA derivatives are needed to be developed in order to safely apply as a skin lightening ingredient. A series of KA derivatives via conjugated with triazole by click reaction were synthesized and their in vitro tyrosinase inhibitory activities were evaluated. Most of all KA derivatives have shown in moderate tyrosinase inhibitory activities. In case of KA-hybrid compound, 1~3 have shown tyrosinase inhibitory activities about 50~10,000 times more effective tyrosinase inhibitor compared to KA itself. Specifically, the $IC_{50}$ value of KA-hybrid compound, 2 was $0.0044{\pm}0.74{\mu}M$ against tyrosinase. It is about 10,000 times more effective tyrosinase inhibitor compared to KA itself ($IC_{50}=45.2{\pm}4.6{\mu}M$).

• Journal of the Society of Cosmetic Scientists of Korea
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• v.24 no.3
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• pp.45-50
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• 1998

13 develop an active agent for skin whitening, we examined the inhibitory effects of 285 plant extracts on tyrosinase activity and found some plant extracts have an ability to inhibit tyrosinase activity. Of these plant extracts, ramulus mori extracts showed the highest inhibiting activity on enzyme activity. From these results, we selected ramulus mori as a new active agent for skin whitening. $IC_{50}$/ of this extracts on tyrosinase activity is 12.48$\mu\textrm{g}$/m1. Also, ramulus mori extracts showed inhibitory activity on melanin synthesis in B-16 melanoma cells. We isolated active compound from ramulus mori extracts using various column chromatography and recrystalization and identified its chemical structure using Mass spectroscopy, IR and NMR analysis. So, it is identified as Mulberrin, a maior compound of ramutus mori and turned out that it has potent ability on tyrosinase inhibition. $IC_{50}$/ of this compound for tyrosinase activity is 0.5$\mu\textrm{g}$/ml. Also, this compound showed potent inhibitory activity on melanin synthesis in B-16 melanoma cells. This extracts was turned out to be safe in many safety tests.

• Proceedings of the SCSK Conference
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• 2003.09b
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• pp.479-479
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• 2003

We investigated the tyrosinase inhibitory effect using whitening materials such as arbutin, ethyl ascorbyl ether, glabridin, kojic acid, magnesium ascorbyl phosphate and ascorbic acid. Tyrosinase inhibition rate were determined varying the enzyme concentration, reaction time, reaction temperature and pH. The optimal conditions to measure the inhibitory efficacy were as follows. : enzyme concentration 1,500 or 2,000IU/mL, reaction time 15min(for the enzyme concentration 1,500 IU/mL) and l0min(for the enzyme concentration 2,000IU/mL), reation temperature 42$^{\circ}C$, pH 6.5. Under these conditions $IC_{50}$/ of arbutin, ethyl ascorbyl ether, glabridin, kojic acid, magnesium ascorbyl phosphate and ascorbic acid were calculated. In the case of magnesium ascorbyl phosphate, the inhibitory effect of tyrosinase was very low and the $IC_{50}$/ of magnesium ascorbyl phosphate could not be calculated. Other five materials showed good inhibitory effect of tyrosinase and can be used for the whitening materials.