• Korean Journal of Pharmacognosy
• /
• v.42 no.4
• /
• pp.323-328
• /
• 2011

We investigated antioxidative activity, tyrosinase inhibitory activity, and melanin production inhibitory activity of the methanol extract of Paeoniae Radix and its fractions. The total polyphenol content of the extract was 73.45 mg/g, and content of the ethyl acetate fraction was 514.50 mg/g as the highest content of fractions. In DPPH radical scavenging ability, $SC_{50}$ values of the ethyl acetate was 3.86 ${\mu}g/ml$ as a result of greater activity in the positive control (ascorbic acid). Moreover, tyrosinase inhibitory activity of the ethyl acetate fraction showed higher activity than arbutin used as a positive control. In the cytotoxicity measurement by MTT assay, the extract and fractions were exhibited cell viabilities of 76.96~157.26% against Raw 264.7 and B16F10 cell in concentration of 10~100 ${\mu}g/ml$. In nontoxic concentration range, the ethyl acetate fraction showed strong melanin production inhibitory effect in ${\alpha}$-melanocyte stimulating hormone (${\alpha}$-MSH)-stimulated B16F10 cell. As a result, the ethyl acetate fraction of the methanol extract from Paeoniae Radix could be applicable to functional materials for skin-whitening agents.

• Animal cells and systems
• /
• v.10 no.4
• /
• pp.233-236
• /
• 2006

For the purpose of the development of skin-whitening or therapeutic agents against hyperpigmentation, aqueous extract from Nardostachys chinensis (AENC) was evaluated for melanogenesis inhibitory activity in B16F10 melanoma cell. The treatment with AENC at the 0.2, 0.5 and 1.0 mg/ml level significantly inhibits the biosynthesis of melanin compared with untreated control. The tyrosinase activity also significantly decreased in AENC-treated cells at the 0.2 and 0.5 mg/ml level and inhibitory effects were more efficient than commercial arbutin at 0.1 mg/ml. The Western analyses confirmed the significantly decreased expression of tyrosinase and tyrosinase-related protein-2 by AENC treatment. These results indicate that AENC may contribute to the inhibition of melanin biosynthesis through regulating the expression as well as activity of tyrosinase and AENC may be useful as a new candidate in the design of new skinwhitening or therapeutic agents.

• Archives of Pharmacal Research
• /
• v.22 no.4
• /
• pp.335-339
• /
• 1999

The oxidation-reduction potentials of cosmetic raw materials, showing tyrosinase inhibitory action, and phenolic compounds structurally similar to L-tyrosine were determined by cylcic voltammetry. The voltammograms obtained could be classified ito 4 patterns (patterns 1-4). Patterns 1, characterized by oxidation and reduction peaks as a pair, was observed with catechol, hydroquinone or phenol, and pattern 2 exhibiting another oxidation peak in addition to oxidation and reduction peaks as a pair was found with arbutin, kojic acid, resorcinol, methyl p-hydroxybenzoate and L-tyrosine as the substrate of tyrosinase. Pattern 3 with an independent oxidation peak only was expressed by L-ascorbic acid, and pattern 4 with a reduction peak only at high potentials, by hinokitiol. The tyrosinase inhibitory activity of these compounds was also evaluated using the 50% inhibitory concentration ($IC_{50}$) and the inhibition constant (Ki) as parameters. Hinokitiol, classified as patterns 4, showed the highest inhibitory activity (lowest $IC_{50}$ and Ki). Hydroquinone showing the second highest activity belonged to pattern 1, which also included compounds exhibiting pattern 2 was relatively low with Ki values being in the order of 10-4 M. Although there was no consistent relationship between oxidation-reduction potentials and tyrosinase inhibitory action, the voltammetry data can be used as an additional index to establish the relationship between the structure and the tyrosine inhibitory activity.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.37 no.12
• /
• pp.1679-1683
• /
• 2008

The objectives of this study were to determine inhibitory effect on tyrosinase activity and antioxidant activity of the methanolic extract from grape seeds and to investigate relationships between tyrosinase inhibitory activity and antioxidant activity of the extract. The 80% methanol extracts of grape seeds were fractionated subsequently with hexane, chloroform, ethyl acetate and water. The methanolic extract and fractions from grape seeds inhibited tyrosinase activity in a concentration dependent manner. The methanolic extracts showed the highest inhibitory effects on tyrosinase activity. The inhibitory effects of the ethyl acetate fraction from the methanolic extract on tyrosinase activity was higher than other fractions. The ethyl acetate fraction from methanolic extracts showed higher antioxidant activity and contained higher polyphenolic and flavonoid contents compared to other fractions. The correlation coefficients among the polyphenoilc content of methanolic extracts, ABTS radical cation scavenging activity and inhibitory effect of tyrosinase were relatively high. These results suggest that grape seeds may have potential as a depigmentation agent for cosmetics and functional food products.

• Journal of Applied Biological Chemistry
• /
• v.50 no.3
• /
• pp.115-119
• /
• 2007

To discover the sources with antioxidant and tyrosinase inhibitory activities in Korean traditional medicines, 10 extract of medicinal plants were screened for their potential to scavenge stable 1,1-diphenyl-2-picryhydrazyl (DPPH) free radical, inhibit hydroxyl radical (${\cdot}OH$), total phenolic content, and inhibition of tyrosinase. The potency of DPPH radical scavenging activity was shown in the extract of Ulmus davidiana var. japonica Nakai that has a greater effect with $IC_{50}$ values of $6.49{\pm}5.43{\mu}g/mL$, than BHA ($IC_{50}=20.99{\pm}0.74{\mu}g/mL$), L-ascorbic acid $(IC_{50}=20.59{\pm}1.06{\mu}g/mL),\;and\;{\alpha}-tocopherol\;(IC_{50}=25.55{\pm}0.26{\mu}g/mL)$ as a positive control. The ${\cdot}OH$ scavenging activities were observed in the plants tested. Acanthopanax senticosus, Cirsium setiders, U. davidiana exhibited scavenging activity of more than 60% at $500{\mu}g/mL$. The scavenging activity(%) of BHA and a-tocopherol were 64.32 and 55.87% at $500{\mu}g/mL$, respectively. The total phenolic content was determined, in order to assess its effect on the extract's antioxidant activity. The total phenoic content of $33.37{\pm}0.52mg/g$ was conformed by methanolic extract of U. davidiana. The U. davidiana and Morus bombycis exhibited tyrosinase inhibitory activity with a $34.28{\pm}1.32\;and\;75.57{\pm}1.10%$, respectively. In particular, M. bombycis has stronger tyrosinase inhibitory activity than albutin with $36.48{\pm}3.56%$ as a positive control. This work showed that the inhibitory abilities of Korean medicinal plants, such as U. davidiana and M. bombycis, on DPPH free radical, inhibit hydroxyl radical (${\cdot}OH$), and inhibition of tyrosinase and total phenolic content, can be useful in the prevention and treatment of free radical-relate disease. Investigations into further isolation of inhibitory principles of U. davidiana and M. bombycis are now in progress.

• YAKHAK HOEJI
• /
• v.52 no.3
• /
• pp.165-171
• /
• 2008

To develop effective skin whitening agents, we tested natural herbal extracts for their melanogenic inhibitory activities. Sedum samentosum was selected for its inhibitory effect on melanogenesis in B16 melanoma cells. Ethanolic extract of S. samentosum (SSE) was evaluated for antioxidative effect and tyrosinase inhibitory activity of melanogenesis. We investigated the changes in protein level and mRNA level of tyrosinase, tyrosinase related protein (TRP)-1 and TRP-2 by using western blotting and RT-PCR, respectively. SSE showed scavenging activities of free radicals and reactive oxygen species (ROS) with the $IC_{50}$ of 342.7 $\mug/ml$ against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and 64.69 $\mug/ml$ against superoxide radicals in the xanthine/xanthine oxidase system, respectively. SSE treatment suppressed the biosynthesis of melanin up to 46% and reduced tyrosinase activity up to 51% at 100 $\mug/ml$ in B16 melanoma cells. The tyrosinase activity and tyrosinase expression in B16 melanoma cells were reduced in a dose-dependent manner by SSE. Also, SSE was able to significantly inhibit tyrosinase and TRP-1 expression in mRNA level. These results suggest that SSE inhibited melanin production which may be dependent on tyrosinase activity and expression in B16 melanoma cells, and an effective whitening agent for the skin.

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

• Natural Product Sciences
• /
• v.3 no.2
• /
• pp.111-121
• /
• 1997

Tyrosinase catalyzes the rate-limiting steps in melanin biosynthesis which is involved in skin-coloring and local hyperpigmentation of human beings, and unfavorable darkening of food products, Inhibitory effects on 3,4-dihydroxy-phenylalanine (dopa) oxidase activity of tyrosinase by 594 kinds of herbal extracts prepared from herbal medicines and wild plants in Korea were estimated. Two herbal extracts prepared from radicis cortex of Morus alba and rhizoma of Curcuma longa were selected as those exhibiting potent inhibitory effects on the enzyme activity. These herbal extracts were subjected to sequential fractionations with methylene chloride, ethyl acetate, n-butanol, and polar residue. The inhibitory effects on dopa oxidase activity of tyrosinase were shown in ethyl acetate fraction of Morus alba, and in methylene chloride fraction of Curcuma langa. The ethyl acetate fraction of Marus alba exhibited 50% of inhibition on dopa oxidase activity of tyrosinase at the concentration of 12 ${\mu}g/ml$, and methylene chloride fraction of Curcuma langa at 51 ${\mu}g/ml$.

• Korean Journal of Pharmacognosy
• /
• v.42 no.2
• /
• pp.155-160
• /
• 2011

In this study, we investigated on antioxidative activity, antibacterial activity against pathogens of acne and tyrosinase inhibitory activity in 75% EtOH extract and its fractions from bark of Prunus sargen tii. The total polyphenol and flavonoidcontent of the EtOAc fraction were found to be 378.0 mg/g and 67.5 mg/g as the highest content. In the measurement of DPPH radical scavenging ability, EtOAc and BuOH fraction were exhibited stronger scavenging ability than the other fractions and 75% EtOH extract. In antibacterial activity by disc diffusion assay against pathogen of acne, antibacterial activity of the EtOAc fraction and 75% EtOH extract was stronger than the other fractions. Especially, the EtOAc fraction was the highest effective fraction in the antibacterial activity. Moreover, tyrosinase inhibitory activity of EtOAc fraction, BuOH fraction and 75% EtOH extract was higher than the other fractions. In particular, tyrosinase inhibitory activity of the EtOAc fraction showed higher activity than ascorbic acid used as positive control.

• Korean Journal of Pharmacognosy
• /
• v.35 no.4 s.139
• /
• pp.380-383
• /
• 2004

The purpose of this study was to evaluate mushroom Tyrosinase inhibitory activity of Cuscuta japonica Choisy and C. australis R.Be. The experimental materials were expressed juice from their stems and flowers, both water and ethanol extracts, their seeds, and two kinds of commercially available cosmetic packing Wontosa and Bupjetosa (made from seeds of C. japonica). The 50% inhibitory concentration $(IC_{50})$ of C. Japonica juice was 5.4 mg/ml. However, C. australis juice showed negligible mushroom tyrosinase inhibitory activity. The $IC_{50}$ of water extracted C. japonica seed was $54.0\;{\mu}g/ml$, water extracted product of Wontosa $50.0\;{\mu}g/ml$ and Bupjetosa $40\;{\mu}g/ml$. The $IC_{50}$ of ethanol extracted C. japonica seed was $10\;{\mu}g/ml$, Wontosa $10\;{\mu}g/ml$ and Bupjetosa $20\;{\mu}g/ml$.