• Journal of Photoscience
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• v.9 no.2
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• pp.205-208
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• 2002

Nitric oxide (NO) is a newly described transmitter involved with cell to cell communication that is generated in biologic tissues by specific types of nitric oxide synthase (NOS), which metabolize L-arginine and molecular oxygen to citrulline and nitric oxide. In the skin. NO has been reported to play an important role in such diseases as psoriasis, atopic dermatitis, and contact dermatitis, as well as act as an important modulator in UVB-induced erythema. Ultraviolet B irradiation to the skin evokes an increase in NO production in the epidermis through two pathways; induction of inducible NOS, mediated by inflammatory cytokines, and elevation of constitutive neuronal NOS activity. In a cell culture system, it has been demonstrated that NO functions as a melanogen after being produced in keratinocytes in response to UVB-irradiation. NO-stimulated melanogenesis in melanocytes is mediated by the cGMP/PKG pathway. In this study, up-regulation of tyrosinase gene expression by NO-stimulation and the involvement of NO in UVB-induced pigmentation were examined. In NO-induced melanogenesis, protein synthesis and tyrosinase activity increased along with an up-regulation of tyrosinase gene expression. In an animal model, UVB-induced pigmentation in skin was suppressed by sequential daily treatments with a specific inhibitor of NOS. Thus, NO plays an important role in UVB-induced pigmentation, where its function as a melanogen is considered to be one of the mechanisms. Together with its role in the development of erythema, NO contributes to the total protective response of skin against UVB-irradiation.

• Korean Journal of Microbiology
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• v.16 no.1
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• pp.11-15
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• 1978

Glucose and galactose were the inhibitors of pigmentation of Serrratia marcescens. Other sugars, however, even the fructose which is the structural isomer of glucose and galactose did not affect to pigmentatioin. The yield of pigmentation was descreased when the glucose was added to culture medium. And it was known to that the antibiotics was roled as the inhibitors of pigmentation. The limit concentration of the inhibitors were as followings :rifampicin, $1{\mu}g/ml$. Addition of rifampicin$(1{\mu}g/ml)$ at 6 hrs cultures inhibited the formation of pigment completely.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.12
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• pp.1799-1803
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• 2003

The possibility of lycopene affecting egg yolk pigmentation was studied with lycopene diets containing 0, 4, 8, and $12{\mu}g/g$ meal, respectively. The addition of lycopene above $4{\mu}g/g$ meal significantly improved yolk color after four days of supplementation. The transfer of lycopene into egg yolk was confirmed by thin layer chromatography, and high-performance liquid chromatography-mass spectrometry (HPLC-MS). The deposition rate of lycopene into egg yolk was approximately 2%, which was quantitatively determined using a HPLC with a UV detector. The result indicates that lycopene is a good candidate for egg yolk pigmentation and for making functional eggs.

• Biomedical Science Letters
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• v.23 no.1
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• pp.8-16
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• 2017

p-Coumaric acid is an organic compound that is a hydroxyl derivative of cinnamic acid. Due to its multiple biological activities p-coumaric acid has been widely studied in biochemical and cellular systems and is also considered as a useful therapeutic candidate for various neuronal diseases. However, the efficacy of p-coumaric acid on zebrafish developmental regulation has not been fully explored. In this study, therefore, we first investigated the action mechanism of the p-coumaric acid on the zebrafish development in a whole-organism model. p-Coumaric acid treated group significantly inhibited the pigmentation of the developing zebrafish embryos compared with control embryos without any severe side effects. In addition, p-coumaric acid down-regulated more effectively in a lower concentration than the well-known zebrafish's melanogenic inhibitor, phenylthiourea. We also compared the molecular docking property of p-coumaric acid with phenylthiourea on the tyrosinase's kojic acid binding site, which is the key enzyme of zebrafish embryo pigmentation. Interestingly, p-coumaric acid interacted with higher numbers of the amino acid residues and exhibited a tight binding affinity to the enzyme than phenylthiourea. Taken all together, these results strongly suggest that p-coumaric acid inhibits the activity of tyrosinase, consequently down-regulating zebrafish embryo pigmentation, and might play an important role in the reduction of dermal pigmentation. Thus, p-coumaric acid can be an effective and non-toxic ingredient for anti-melanogenesis functional materials.

• Korean Journal of Poultry Science
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• v.30 no.1
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• pp.35-40
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• 2003

This experiment was conducted to investigate the effects of natural and synthetic commercial pigments on the growth performances, skin pigmentation and color difference of broiler chicks. Experimental diet was formulated to have isocalories and isonitrogen for experimental period, and xanthophyll concentration in the diet was 8.45g/1on. The experiment was conducted for six weeks with 450 broiler chicks. The birds were assigned to 10 treatment groups and each group had 15 chicks with three replications. Results showed that the types of pigments did not have any effect on body weight, feed intake and feed efficiency. The mortality was lower with higher pigment supplementation and greater in the natural pigment groups than in the synthetic ones. Dressed carcass, abdominal fat pad and gizzard weight were not significantly different among treatments. The pigmentation of shank skin was increased with high pigment supplementations, and the pigmentation effect was greater with synthetic pigments than in natural pigments. In the shank meat or skin, the color difference(L*, a*, b*, c* and h*) was not consistently related to pigmentation.

• Journal of Korea Multimedia Society
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• v.16 no.9
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• pp.1044-1056
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• 2013

This paper presents an approach for detecting and measuring human skin pigmentation. In the proposed scheme, we extract a skin area by a GMM-EM clustering based skin color model that is estimated from the statistical analysis of training images and remove tiny noises through the morphology processing. A skin area is decomposed into two components of hemoglobin and melanin by an independent component analysis (ICA) algorithm. Then, we calculate the intensities of hemoglobin and melanin by using the projection transformed block coefficient and determine the existence of skin pigmentation according to the global and local distribution of two intensities. Furthermore, we measure the area and density of the detected skin pigmentation. Experimental results verified that our scheme can both detect the skin pigmentation and measure the quantity of that and also our scheme takes less time because of the location histogram.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.12
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• pp.1659-1664
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• 2013

The objectives of this study were to investigate color patterns of shell and mantle edge pigmentation of a Pacific oyster, C. gigas, and to estimate variance components of the two colors. A sample of 240 F0 oysters was collected from six aquaculture farms in Tongyeong, Korea to measure shell color and mantle edge pigmentation. Among the F0s, male and female individuals with black (white) shell and black (white) mantle edge were selected and mated to generate three F1 full-sib black (white) cross families (N = 265). Two and four F2 cross families (N = 286) were also produced from black and white F1 selected individuals, respectively. Variance component estimates due to residuals and families within color were obtained using SAS PROC VARCOMP procedures to estimate heritability of shell and mantle edge pigmentation. In the F0 generation, about 29% (11%) had black (white) color for both shell and mantle edge. However, in the F1 and F2 black (white) cross families, 75% (67%) and 100% (100%) of oysters had black (white) shell colors, and 59% (23%) and 79% (55%) had black (white) mantle edge, respectively. Spearman correlation coefficients between shell and mantle edge color were 0.25, 0.74, and 0.92 in F0, F1, and F2 generations, respectively, indicating that, with generations of selection process, an individual with black (white) shell color is more likely to have black (white) mantle edge pigmentation. This suggests that shell color could be a good indicator trait for mantle edge pigmentation if selection of both the colors is implemented for a couple of generations. Estimates of heritability were 0.41 and 0.77 for shell color and 0.27 and 0.08 for mantle edge pigmentation in the F1 and F2 generations, respectively, indicating that, in general, significant proportions of phenotypic variations for the shell and mantle edge colors are explained by genetic variations between individuals. These results suggest that the two color traits are inheritable and correlated, enabling effective selection on shell and mantle edge color.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.2
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• pp.177-182
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• 2023

Since facial skin pigmentation is one of the visual characteristics of skin aging, it is important to evaluate skin pigmentation in the cosmetics and aesthetic fields. Several groups have investigated and developed the image analysis methods for skin pigmentation and some of the groups reported the age-related changes of the number and size of facial pigmented spots. However, they didn't show the changes of the number and size of pigment spots by defined size, and there is no report for Korean female regarding pigmentation. A total of 194 Korean females aged 20 ~ 79 (48.97 ± 17.11 years) were analyzed for the number, size, and intensity of pigmented spots using various filters such as large high-pass filter and median filter in their digital facial images. There were significant correlations between age and total pigmented spot number (No.), size, and intensity (I) (pearson's correlation coefficient r = 0.688, r = 0.645, r = -0.563), and significant correlations were also observed between the number and intensity of pigmented spots of different sizes. According to the ANOVA results, there were significant differences in the percentage of spot size of 2 ~ 4 mm² and > 20 mm² between 20's and 70's. In other words, with aging, pigmentation increases in the facial skin, and the large increase in pigmentation is particularly noticeable in Korean women.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.06a
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• pp.306-310
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• 2005

Exposure to UVB radiation can cause diverse biological photodamage to skin. Eeb 761 and Korean red ginseng are the major and most effective natural drug against a variety of oxidative damage. But, the protective effects against UVB radiation have not been clearly identified. In this study, we investigated the protective effect of topical EGb 761 and Korean red ginseng on pigmentation by UVB radiation. Pro-inflammatory cytokines($IL-l{\beta}$, IL-6 and $TNF-{\alpha}$) and melanogenesis proteins(tyrosinase, TRP-1 and TRP-2) mRNA were measured by reverse transcription-polymerase chain reaction(RT-PCR) analysis. The in vivo protection against pigmentation was calculated using chromameter. The mRNA level of IL-lf and TNF-a were increased by UVB irradiation in treated and non-treated group, while no significant changes were observed in IL-6 level. Topical treatment with EGb 761 and Korean red ginseng remarkably reduced expression of tyrosinase, TRP-1 and TRP-2 in the non-irradiated and irradiated skin. Application of EGb 761 and Korean red ginseng significantly protected the WB-induced skin pigmentation and Korean red ginseng was more effective. Our study suggests that topical ECb761 and Korean red ginseng can regulate melanogenic proteins and protect UVB radiation on skin pigmentation.

• Archives of Plastic Surgery
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• v.38 no.6
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• pp.725-732
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• 2011

Purpose: Skin grafting is one of the most commonly used methods in reconstructive plastic surgery field, but complications such as color change, contracture or hypertrophy are common problems. However, pathophysiology of the color change after skin graft is not yet determined and no animal model is established. Methods: Full thickness skin grafts were performed on the dorsum of C57BL/6 mice. Serial chronological gross inspection for color change and pigmentation were examined. Melanin pigments were traced by Fontana-Masson staining and semi-quantitative analysis was performed. In addition, immunohistochemical staining of S-100, Micropthalmia related Transcription Factor (MITF) and Melan-A antibodies were also performed to observe melanocytes and their changes. Results: After skin graft, color change and pigment spots were observed in the graft. Fontana-Masson staining showed melanin pigments in the epidermal and dermal layers in all mice. Immunohistochemistry staining to S-100, MITF, Melan-A antibodies showed melanocytes at the basal layer of epidermis and dermis. Conclusion: In conclusion, we have established an animal model for skin pigmentation after skin graft. We believe this study may be useful in understanding of the behavior of melanocytes after skin graft.