• Journal of the Society of Cosmetic Scientists of Korea
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• v.28 no.1
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• pp.135-149
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• 2002

To date, research on the regulation of melanogenesis has focused on factors which affect tyrosinase, the rate-limiting enzyme in the melanogenic pathway, by searching for chemicals which competitively inhibit tyrosinase function. Many types of tyrosinase inhibitors have been developed, but no satisfactory results have been made clinically until now, To find a new whitening agent, which effectively inhibits melanogenesis, we synthesized several compounds and selected compounds by cell-based assay system. Finally, 3, 4, 5-trimethoxy cinnamaie thymol ester(TCTE, Melasolv) was selected and the effects of TCTE on melanogenesis were investigated. Treatment of mouse-derived melanocyte melan-a cells with TCTE results in a marked down-regulation of tyrosinase activity. 80% decrease of tyrosinase activity occurs with 30uM TCTE treatment for 72 hours without affecting cell growth. The inhibition of tyrosinase activity is dose-dependent and melanin content was also decreased to 40%. From the in vitro tyrosinase assay using cell extract, TCTE does not act as a direct inhibitor of the enzyme. Treatment of melan-a cultures with TCTE blocks the increase in tyrosinase activity by either forskolin, 3-isobutyl-1-methtyl-xanthine. TCTE decreased the expression of tyrosinase, TRP-1 without effects on TRP-2 protein expression through the down regulation of tyrosinase and TRP-1 mRNA. From the results of cAMP immunoassays, intracellular levels of the cyclin nucleotide are unaffected in cells treated with TCTE. The inhibitory effects of melanin synthesis were also shown in reconstitute human epidermis model by topical application. These findings suggest that TCTE can be used for studying the regulation of melanogenesis and depigmenting agent.

• The Korean Journal of Physiology and Pharmacology
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• v.24 no.2
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• pp.149-156
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• 2020

Sodium 2-mercaptoethanesulfonate (mesna) is a protective agent that is widely used in medicine because of its antioxidant effects. Recently, reactive oxygen species (ROS) were shown to increase pigmentation. Thus, ROS scavengers and inhibitors of ROS production may suppress melanogenesis. Forkhead box-O3a (FoxO3a) is an antimelanogenic factor that mediates ROS-induced skin pigmentation. In this study, we aimed to investigate the whitening effect of mesna and the signaling mechanism mediating this effect. Human melanoma (MNT-1) cells were used in this study. mRNA and protein expression were measured by real-time quantitative PCR and Western blotting analysis to track changes in FoxO3a-related signals induced by mesna. An immunofluorescence assay was performed to determine the nuclear translocation of FoxO3a. When MNT-1 melanoma cells were treated with mesna, melanin production and secretion decreased. These effects were accompanied by increases in FoxO3a activation and nuclear translocation, resulting in downregulation of four master genes of melanogenesis: MITF, TYR, TRP1, and TRP2. We found that mesna, an antioxidant and radical scavenger, suppresses melanin production and may therefore be a useful agent for the clinical treatment of hyperpigmentation disorders.

• Korean Journal of Pharmacognosy
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• v.51 no.4
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• pp.302-309
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• 2020

The objective of this study was to optimize the condition for induction and proliferation of callus from Rhus chinensis Mill. and investigate the skin-brightening effect of Rhus chinensis callus (RCC). It was confirmed that the most proper plant growth regulator (PGR) for callus induction is 1.0 mg/L of 2,4-dichlorophenoxyacetic acid (2,4-D). The most optimal condition of PGR, medium and additives for callus proliferation were 2,4-D (1.0 mg/L), MS medium and citric acid, respectively. Inhibitory activities of tyrosinase were higher at 50 and 100 ㎍/mL of RCC extracts (41.86 and 75.56%, respectively) than arbutin (27.32%). As the results of measuring melanin inhibition in B16F1 melanocyte and B16F10 melanoma cell, RCC extracts increased its inhibitory activities concentration-dependently, and were found to have higher whitening effect than arbutin at a concentration of 100 ㎍/mL. Therefore, it is suggested that RCC can be used as an effective material for skin-brightening cosmetics.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.3
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• pp.649-653
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• 2008

The aqueous extract from Asiasari radix (AEAR) was used to investigate the effect of ${\alpha}$-melanocyte stimulating hormone induced melanogenesis in B16F10 mouse melnoma cells. The treatment with AEAR at the 1.0 and 2.0 mg/ml level significantly inhibited the biosynthesis of melanin without changes of cell growth and morphology compared with untreated control. The AEAR-treated cells at the 2.0 mg/ml level were more efficient than commercial arbutin at 0.1 mg/ml. The tyrosinase activity also significantly decreased in AEAR-treated cells at the 1.0 and 2.0 mg/ml level. The Western analyses confirmed the slightly decreased expression of tyrosinase by AEAR treatment. These results indicate that AEAR may contribute to the inhibition of melanin biosynthesis through regulating tyrosinase activity and expression and serve as a new candidate in the design of new skin-whitening or therapeutic agents.

• Journal of Microbiology and Biotechnology
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• v.20 no.6
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• pp.988-994
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• 2010

The EtOAc fraction of Lespedeza cyrtobotrya showed mushroom tyrosinase inhibitory and radical scavenging activities. Four active compounds were isolated based on Sephadex LH-20 chromatography and HPLC, and the structures were elucidated, on the basis of their LC-MS and NMR spectral data, as 2-(2,4-dihydroxyphenyl)-6-hydroxybenzofuran (1), eriodictyol-7-O-glucopyranoside (2), haginin A (3), and dalbergioidin (4), respectively. Compound (1) showed mushroom tyrosinase inhibitory activity with an $IC_{50}$ value of $5.2\;{\mu}M$ and acted as a competitive inhibitor. Furthermore, $37.3\;{\mu}M$ of compound 1 reduced 50% of the melanin content on human melanoma (MNT-1) cells. The radical scavenging activities of compounds 1, 2, 3, and 4 were shown to have $IC_{50}$ values of 11.0, 24.5, 9.0, and $36.5\;{\mu}M$, respectively, in an ABTS system and $IC_{50}$ values of 42.7, 36.0, 37.7, and $61.7\;{\mu}M$, respectively, in a DPPH system. The mushroom tyrosinase inhibitory activity of the EtOAc fraction of Lespedeza cyrtobotrya was contributed by compounds 1, 3, and 4, and its radical scavenging activity was contributed by compounds 1-4.

• BMB Reports
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• v.43 no.7
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• pp.461-467
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• 2010

Natural products with non-toxic and environmentally friendly properties are good resources for skin-whitening cosmetic agents when compared to artificial synthetic chemicals. Here, we investigated the effect of glyceollin produced to induce disease resistance responses of soybean to specific races of an incompatible pathogen, phytophthora sojae, on melanogenesis and discussed their mechanisms in melanin biosynthesis. We found that glyceollin inhibits melanin synthesis and tyrosinase activity in B16 melanoma cells without cytotoxicity. To elucidate the mechanism of the effect of glyceollin on melanogenesis, we conducted western blot analysis for melanogenic enzymes such as tyrosinase, tyrosinase-related protein-1 (TRP-1), and TRP-2. Glyceollin inhibited tyrosinase and TRP-1 protein expression. Additionally, glyceollin effectively inhibited intracellular cAMP levels in B16 melanoma cells stimulated by $\alpha$-melanocyte stimulating hormone ($\alpha$-MSH). These results suggest that the whitening activity of glyceollin may be due to the inhibition of cAMP involved in the signal pathway of $\alpha$-MSH in B16 melanoma cells.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.50 no.2
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• pp.131-141
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• 2024

In this study, the efficacy of antioxidant and whitening factors was analyzed in order to verify the possibility of use as functional cosmetic materials related to antioxidant and whitening by using the extract of Oryza sativa cv. Heugjinmi. As a result, S OD-like activity, FRAP, reducing power, xanthine oxidase inhibitory activity, and elastase inhibitory activity were similar to those of the control group. Tyrosinase inhibitory activity had no effect in hydrothermal extract and 59% inhibitory activity in ethanol extract. Ethanol extract was found to inhibit cellular tyrosinase inhibitory activity and melanin biosynthesis at concentrations of 25, 50, and 100 ㎍/mL, which will not affect survival in the B16F10 cell line. In addition, the results of confirming the mRNA expression of tyrosinase, TRP-1, and TRP-2 showed inhibition rates of 37%, 51%, and 34%, respectively, at the highest concentration of 100 ㎍/mL. Therefore, it is believed that O. sativa extract has potential to be utilized as a functional cosmetic material related to antioxidant and whitening.

• The Korean Journal of Physiology and Pharmacology
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• v.25 no.1
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• pp.87-94
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• 2021

Skin photoaging occurs due to chronic exposure to solar ultraviolet radiation (UV), the main factor contributing to extrinsic skin aging. Clinical signs of photoaging include the formation of deep, coarse skin wrinkles and hyperpigmentation. Although melanogenesis and skin wrinkling occur in different skin cells and have different underlying mechanisms, their initiation involves intracellular calcium signaling via calcium ion channels. The ORAI1 channel initiates melanogenesis in melanocytes, and the TRPV1 channel initiates MMP-1 production in keratinocytes in response to UV stimulation. We aimed to develop a drug that may simultaneously inhibit ORAI1 and TRPV1 activity to help prevent photoaging. We synthesized nootkatol, a chemical derivative of valencene. TRPV1 and ORAI1 activities were measured using the whole-cell patch-clamp technique. Intracellular calcium concentration [Ca2+]i was measured using calcium-sensitive fluorescent dye (Fura-2 AM). UV-induced melanin formation and MMP-1 production were quantified in B16F10 melanoma cells and HaCaT cells, respectively. Our results indicate that nootkatol (90 μM) reduced TRPV1 current by 94% ± 2% at -60 mV and ORAI1 current by 97% ± 1% at -120 mV. Intracellular calcium signaling was significantly inhibited by nootkatol in response to ORAI1 activation in human primary melanocytes (51.6% ± 0.98% at 100 μM). Additionally, UV-induced melanin synthesis was reduced by 76.38% ± 5.90% in B16F10 melanoma cells, and UV-induced MMP-1 production was reduced by 59.33% ± 1.49% in HaCaT cells. In conclusion, nootkatol inhibits both TRPV1 and ORAI1 to prevent photoaging, and targeting ion channels may be a promising strategy for preventing photoaging.

• The Korea Journal of Herbology
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• v.32 no.3
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• pp.71-78
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• 2017

Objectives : The various grape extracts derived from grape pulp, seed and skin, containing various types of polyphenols and flavonoids, have been known to have anti-inflammatory, antioxidant and improve cardiovascular condition as well as sun's damaging effects. However, there have been rare reports of various beneficial effects of grape fruit stem extract (GFSE), one of the waste products of grapes. We investigated anti-inflammatory and melanogenesis inhibitory effects of GFSE. Methods : One-hundred gram of grape fruit stem was extracted with 80% ethanol at room temperature for 3 days. After filtration, the ethanol was removed using vacuum evaporator, then lyophilized to obtain the dry extract which was stored at $-20^{\circ}C$ until used. NO levels were measured by using Greiss reagent. Prostaglandin $E_2$ ($PGE_2$) production was measured by ELISA assay. The expression levels of iNOS, COX-2, TRP-1 and TRP-2 were evaluated by western blot analysis. Results : GFSE reduced the level of nitric oxide and prostaglandin $E_2$ ($PGE_2$) production in a dose-dependent manner, compared to control. Expressions of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) protein were also effectively inhibited by the GFSE. In a tyrosinase inhibitory activity, GFSE significantly reduced the tyrosinase activity and melanin content in a dose dependent manner, compared to control. GFSE also decreased the expression of tyrosinase related protein-1 (TRP-1) and tyrosinase related protein-2 (TRP-2), known as a melanocyte-specific gene product involved in melanin synthesis. Conclusions : Therefore, these results indicated that GFSE had powerful anti-inflammatory and anti-melanogenic effects.

• Journal of Life Science
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• v.33 no.2
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• pp.169-175
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• 2023

As a protective defensive mechanism against ultraviolet (UV) light exposure in skin tissue, melanocytes produce the pigment melanin. Tyrosinase plays a key role in melanin production in melanocytes. However, the overproduction of melanin can lead to lesions, such as freckles and dark spots. Thus, it is clinically important to find a modulating molecule to control melanogenesis by regulating tyrosinase expression and/or activity. It is known that catechin, a plant flavonoid, can reduce melano- genesis through the downregulation of tyrosinase expression. Here, we tested whether catechin derivatives isolated from the stem bark of Ulmus parvifolia have an effect on melanin production by regulating tyrosinase in mouse melanoma cells and in vitro mushroom tyrosinase. The catechin derivatives used in this study included C5A, C7A, C7G, and C7X. Treatments using these catechin derivatives reduced melanin production in mouse melanoma B16F10 cells in which melanogenesis was stimulated by α-MSH. Notably, the anti-melanogenic effects of catechin derivatives were similar to those of kojic acid, a well-known anti-melanogenic molecule. Both C5A and C7A directly inhibited the activity of tyrosinase isolated from mushrooms in vitro. Furthermore, our in silico computational simulation showed that these two compounds were expected to bind to the active site of tyrosinase, which is similar to kojic acid. In addition, all four catechin derivatives reduced tyrosinase protein expression. In summary, our results showed that catechin derivatives can reduce melanogenesis by regulating tyrosinase activity or expression. Thus, this study suggests that catechin derivatives isolated from U. parvifolia can be novel modulators of melanin production.