• Journal of the Society of Cosmetic Scientists of Korea
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• v.41 no.2
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• pp.97-103
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• 2015

Until recently, the three conventional evaluation methods, which are instrumental (Chromameter$^{(R)}$ CR-400 and Mexameter$^{(R)}$ M18) and visual assessments have been used frequently for skin color evaluation. However, we took notice the potential of image analysis as a new tool to evaluate color change of skin. To reveal the reliability of the image analysis for the evaluation of whitening agents, 34 healthy female volunteers with hyperpigmentation were recruited, and the selected volunteers applied the whitening products containing Vitamin C twice a day in the morning and evening and received iontophoresis treatments once a week for 8 weeks. The changes in hyperpigmentation evaluated by Chromameter$^{(R)}$, Mexameter$^{(R)}$ and visual assessment were compared with the results from the image analysis. As with $L^*$ value trends of the analysis using Chromameter$^{(R)}$, the V value from the image analysis increased after applying the test products compared with baseline values. Furthermore, V value showed a positive correlation with $L^*$ value (r = 0.494, p < 0.01) and negative correlation with MI (r = - 0.683, p < 0.01) and VG (r = - 0.549, p < 0.01). Therefore, image analysis may be considered as an effective method to complement the limitations of visual assessment for whitening efficacy in Asians.

• Korean Journal of Plant Resources
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• v.14 no.1
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• pp.32-37
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• 2001

Mammalian tyrosinase plays an important role in the process of melanin polymer biosynthesis by catalyzing the hydroxylation of tyrosine to 3,4-dihydroxyphenylalanine(DOPA) and the oxidation of DOPA to dopaquinone. These processes are major determinant of human skin color and involved in localized hyperpigmentation. Therefore, the enzyme inhibitors have been of great concern as skin-whitening cosmetics. Methanol extracts of 174 oriental herbs were screened for the mushroom tyrosinase inhibitory activity.

• Journal of Yeungnam Medical Science
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• v.12 no.2
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• pp.405-411
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• 1995

Lichenoid drug eruption is lichenoid skin eruptions caused by certain drugs and compounds, and can be identical or similiar to lichen planus. A 75-year-old woman who had taken antituberculosis medication(INH, ethambutol, rifampin) for 4 months developed pruritic generalized erythematous papular eruptions on the trunk and extremities, alopecia and nail dystropy. Histopathologic findings were hyperkeratosis, hypergranulosis, hydrophic degenaration of basal layer, band like lymphohistiocytic infiltration in the upper dermis and perivascular lymphohistiocytic infiltration in the deep dermis. She was treated with systemic corticosteroid, and then skin lesion were slightly improved. After termination of antituberculosis medication, skin lesions were markedly improved with residual hyperpigmentation. Alopecia and nail dystrophy were also improved.

• Journal of Life Science
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• v.32 no.5
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• pp.331-339
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• 2022

Melanin is a pigment produced by melanocytes to protect the skin from external stimuli, mainly ultraviolet (UV) rays. However, abnormal and excessive production of melanin causes hyperpigmentation disorders, such as freckles, age spots, and discoloration. Natural cosmeceuticals are a new trend for treating or preventing hyperpigmentation due to fewer side effects and biocompatibility. In this context, the current study focused on Cnidium japonicum, a halophyte with several uses in folk medicine, to evaluate its potential as a skin-whitening agent. The effect of C. japonicum extract (CJE) on melanin production was analyzed in melanogenesis-stimulated B16F10 melanoma cells. The results showed that CJE successfully inhibited the oxidation of tyrosine and L-DOPA by tyrosinase and subsequently decreased the production of the key enzymes responsible for melanin production: tyrosinase, tyrosinase-related protein-1, and protein-2. This effect was confirmed by decreased intracellular and extracellular melanin levels in B16F10 melanoma cells after CJE treatment. Further experiments to elucidate the action mechanism revealed that CJE treatment suppressed melanin production by inhibiting the activation of glycogen synthase kinase 3 β (GSKβ)/β-catenin and protein kinase A (PKA)/cAMP-response element binding protein (CREB) pathways, which are the upstream activators of melanogenesis. In conclusion, the present study suggests that C. japonicum is a potential natural source of bioactive substances for the development of novel cosmeceuticals that can act against hyperpigmentation.

• Korean Journal of Veterinary Research
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• v.39 no.5
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• pp.1017-1020
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• 1999

Fifteen dogs with superficial pyoderma were investigated clinically. Dermatological signs were mainly consisted of papule (66.6%), pustule (86.6%), epidermal collrarette and patchy (40%), and hyperpigmentation (53.3%). Distribution of skin lesion were consisted of back (35.5%), abdomen (29.0%), axillary (6.4%), leg (3.2%), neck (3.6%) and foot (16.1%), respectively. In pustular cytology PMN cells and cocci were examined. Cephalexin was very effective antibiotics on superficial pyoderma at administration of 30mg/kg bid P.O. for 3 weeks. Hyperadrenocorticism and atopy were diagnosed as a primary cause on pyoderma in 2 dogs.

• Archives of Plastic Surgery
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• v.38 no.6
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• pp.829-835
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• 2011

Purpose: The two major concerns in skin grafting are poor color match in the recipient site and the donor site morbidity. And, glabrous skin on the palmar aspect of the hands and plantar aspect of the feet attributes define the skin on the palm and fingers sole as functionally and aesthetically different from skin on other parts of the body. When there is a glabrous skin defect, it should be replaced with similar skin to restore function and aesthetics. The palmar crease areas were used to minimize these problems. The purpose of this study is to present the precise surgical technique of the full thickness skin graft using distal palmar and midpalmar creases for aesthetic better outcome for hand injuries. Methods: From May 2006 to April 2010, 10 patients with 11 defects underwent glabrous full thickness skin grafting of finger defects. Causes included seven machinery injuries, two secondary burn reconstructions, and one knife injury. Donor sites included ten glabrous full thickness skin graft from the distal palmar crease and one from the midpalmar crease. Results: Follow-up ranged from 3 months to 24 months. All glabrous skin grafts demonstrated complete taking the recipient sites and no incidence of the complete or partial loss. The donor site healed without complications, and there were no incidences of significant hypopigmantation, hyperpigmentation, or hypertrophic scarring. Conclusion: The important aspects of this method involve immediate return of glabrous skin to the defect site and restoration of the recipient site's crease by simple primary closure from adjacent skin. The glabrous skin of the palm provides the best tissue match for the reconstruction of the hands, but only a limited amount of tissue is available for this purpose. Full thickness skin grafting using palmar crease of the defects is the ideal way of reconstructing glabrous skin to restore both function and aesthetics and minimize donor site morbidity.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2007.11a
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• pp.129-139
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• 2007

Many modalities of treatment for acquired skin hyperpigmentation are available including chemical agents or physical therapies, but none are completely satisfactory. The ideal depigmenting compound should have a potent. rapid and selective bleaching effect on hyperactivated melanocytes, carry no short- or long-term side-effects and lead to a permanent removal of undesired pigment. acting at one or more steps of the pigmentation process. Depigmentation can be achieved by regulating (i) the transcription and activity of tyrosinase, tyrosinase related protein-1 (TRP-1), tyrosinase related protein-2 (TRP-2), and/or peroxidase; (ii) the uptake and distribution of melanosomes in recipient keratinocytes and (iii) melanin and melanosome degradation and turnover of pigmented keratinocytes. One of the interesting point for development of skin whitening agent is Mitf(Microphthalmia-associated transcription factor). Mitf belongs to the basic helix-loop-helix-zip family of trabscription factors and it is crucial as it regulates both melanocyte proliferation as well as melanogenesis and is the major regulator of tyrosinase and the related enzymes (TRPs), as well as many melanosome structural proteins such as pMel17. Recently, we developed MITF-down-regulating agents from natural and synthetic sources, which have anti-melanogenic effect on in vitro and in vivo. We suggested that potent MITF-down regulating agents might be used for skin whitening cosmeceuticals.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.26 no.1
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• pp.149-162
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• 2000

Coenzyme Q10 is found in all tissues including skin and it is the well-known coenzyme for mitochondrial enzymes. The electron and proton transfer functions of the quinone ring are of fundamental importance for the oxidative phosphorylation pathway to generate energy in the cells. Coenzyme Q10 has been studied as a potent antioxidant molecule in the skin. It is involved in the skin's response to UVR irradiation. The concentration of this antioxidant in UVR exposed skin is higher than in non-exposed skin. However, recent studies have also shown that coenzyme Q10 is one of the first antioxidants to be depleted when skin is UVR-irradiated. This indicates that coenzyme Q10 is primarily involved in defense mechanisms of the skin. Therefore, we questioned whether coenzyme Q10 shows reulatory effect of melanogenesis. Here we report that coenzyme Q10 inhibits melanin neosynthesis of normal human melanocytes grown in culture, and lightens UVB-induced hyperpigmentation of the guinea pig skin in vivo. We treated human melanocytes with 0.05mM to 0.5mM of coenzyme Q10 for a total of two days. This inhibited melanin neosynthesis of cultured human melanocytes dose-dependently. The inhibitory effect of coenzyme Q10 was as effective as kojic acid or vitamin C on cultured human melanocytes. CoQ10 didn't have direct inhibitory effect on tyrosinase activity in in vitro tyrosine hydroxylase activity To further clarify the effect of coenzyme Q10 on the melanogenesis, we established UVB-induced hyperpigmentation on the shaved backs of brownish guinea pigs. The UVB intensity was 500mJ/$\textrm{cm}^2$ and the total energy dose was 1,500 mJ/$\textrm{cm}^2$. The animals were exposed to UVB radiation one times a week for three consecutive weeks. Coenzyme Q10, kojic acid, Arbutin, vitamin C(1% in vehicle) or vehicle alone as a control were then topically applied daily to the hyperpigmented areas twelve times per week far four successive weeks. The lightening effect was evaluated by visual scoring, chromameter and immunohistochemistry. Coenzyme Q10 had lightening effect on the UVB-induced hyperpigmentation without any other side effects, whereas another compounds showed weak lightening efficacies. Therefore, these results suggest that coenzyme Q10 may be useful for solving physiological hyperpigmenting problems for cosmetic purposes.

• YAKHAK HOEJI
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• v.59 no.4
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• pp.177-183
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• 2015

The mechanism of melanogenesis induced by cyclosporin A (CsA) was investigated in B16 melanoma cells. CsA stimulated the production of melanin in a dose-dependent manner in the cells. In addition, CsA increased intracellular $Ca^{2+}$ concentration in a dose-related fashion. Treatment with BAPTA/AM, an intracellular $Ca^{2+}$ chelator significantly inhibited the CsA-induced intracellular melanin synthesis. CsA profoundly induced $Cl^-$ efflux, which was significantly blocked by niflumic acid (NFA) and flufenamic acid (FFA), specific and nonspecific inhibitors of $Ca^{2+}$-activated $Cl^-$ channels (CaCCs), respectively. Furthermore, these inhibitors of CaCCs significantly inhibited the CsA-induced stimulation of melanin synthesis. Taken together, these results suggest that the activation of CaCCs may play an important role in the CsA-induced stimulation of melanin synthesis in B16 cells. These results further suggest that CaCCs may be a good target for the management of hyperpigmentation of the skin reported in the patients treated with CsA.

• Medical Lasers
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• v.8 no.2
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• pp.74-79
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• 2019

Periorbital melasma is often refractory to treatment and highly associated with rebound hyperpigmentation or mottled hypopigmentation after laser treatment in Asian patients. In this report, we describe 2 patients with cluster-1 periorbital melasma and 1 patient with cluster-2 periorbital melasma who experienced remarkable clinical improvements after microwave-generated, atmospheric-pressure, non-thermal nitrogen plasma treatments. All patients exhibited limited clinical responses after combination treatments with topical bleaching agents, systemic oral tranexamic acid, and low-fluenced Q-switched neodymium (Nd):yttrium-aluminum-garnet (YAG) lasers. Low-energy nitrogen plasma treatment at 0.75 J elicited remarkable clinical improvement in the periorbital melasma lesions without post-laser therapy rebound hyperpigmentation and mottled hypopigmentation. We deemed that a single pass of nitrogen plasma treatment at 0.75 J induces mild microscopic thermal tissue coagulation and modification within the epidermis while preserving the integrity of the basement membrane in patients with periorbital melasma. Accordingly, nitrogen plasma-induced dermal tissue regeneration could play a role in the treatment of melasma lesions.