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[Normal and abnormal skin color.]
Abstract
The varieties of normal skin color in humans range from people of "no color" (pale white) to "people of color" (light brown, dark brown, and black). Skin color is a blend resulting from the skin chromophores red (oxyhaemoglobin), blue (deoxygenated haemoglobin), yellow-orange (carotene, an exogenous pigment), and brown (melanin). Melanin, however, is the major component of skin color ; it is the presence or absence of melanin in the melanosomes in melanocytes and melanin in keratinocytes that is responsible for epidermal pigmentation, and the presence of melanin in macrophages or melanocytes in the dermis that is responsible for dermal pigmentation. Two groups of pigmentary disorders are commonly distinguished: the disorders of the quantitative and qualitative distribution of normal pigment and the abnormal presence of exogenous or endogenous pigments in the skin. The first group includes hyperpigmentations, which clinically manifest by darkening of the skin color, and leukodermia, which is characterized by lightening of the skin. Hypermelanosis corresponds to an overload of melanin or an abnormal distribution of melanin in the skin. Depending on the color, melanodermia (brown/black) and ceruloderma (blue/grey) are distinguished. Melanodermia correspond to epidermal hypermelanocytosis (an increased number of melanocytes) or epidermal hypermelanosis (an increase in the quantity of melanin in the epidermis with no modification of the number of melanocytes). Ceruloderma correspond to dermal hypermelanocytosis (abnormal presence in the dermis of cells synthesizing melanins) ; leakage in the dermis of epidermal melanin also exists, a form of dermal hypermelanosis called pigmentary incontinence. Finally, dyschromia can be related to the abnormal presence in the skin of a pigment of exogenous or endogenous origin.
Copyright © 2012 Elsevier Masson SAS. All rights reserved.
... Its appearance is due to the blend of pigments or chromophores that absorb particular electromagnetic wavelengths and transmit or reflect them to the visible light spectrum [2][3][4] . The most important are oxyhemoglobin, which reflects the red color, deoxyhemoglobin, which reflects blue, carotenes, which reflect yellow-orange and melanin, which reflects the brown color 3,5,6 . Melanin is the main pigment that determines dark or light tone according to its concentration in the epidermis 2,3 . ...
... This variable represents an adaptive process to the geographic surroundings with clinical repercussions. Therefore, measuring pigmentation in a population is relevant, since it translates its predisposition for suffering environmental harm, as well as the possible presence of local or systemic pathologies 5,16,19 . This work represents the first study in Mexico that measures skin coloration by means of diffuse reflectometry. ...
... On the other hand, identification of extreme chromatic values suggests the presence of pathologies that modify integumentary color or can be useful to monitor them. Some examples are melanogenesis and angiogenesis disorders, as well as deposits of endogenous pigments, such as bilirubin, or exogenous, such as heavy metals 5 . ...
... Su aspecto se debe a la mezcla de pigmentos o cromóforos que absorben determinadas longitudes electromagnéticas y las transmiten o reflejan en el espectro de luz visible [2][3][4] . Los más importantes son la oxihemoglobina, que refleja el color rojo, la desoxihemoglobina, que refleja el azul, los carotenos, que reflejan el amarillo-naranja y la melanina, que refleja el marrón 3,5,6 . La melanina es el principal pigmento que determina el tono oscuro o claro según su concentración en la epidermis 2,3 . ...
... Esta variable representa un proceso adaptativo al entorno geográfico con repercusiones clínicas. Por lo tanto, medir la pigmentación en una población tiene relevancia ya que traduce la predisposición para sufrir daño ambiental, así como la posible presencia de patologías locales o sistémicas 5,16,19 . Este trabajo representa el primer estudio en México que mide la coloración cutánea mediante reflectometría difusa. ...
... Por otra parte, la identificación de valores cromáticos extremos sugiere la presencia o puede ser útil para monitorear enfermedades que modifican el color tegumentario. Algunos ejemplos son los trastornos de melanogénesis, angiogénesis y el depósito de pigmentos endógenos como bilirrubinas o exógenos como metales pesados 5 . ...
Antecedentes:
La mezcla de melanina, hemoglobina y carotenos definen el color cutáneo. La pigmentación constitutiva está determinada genéticamente, la facultativa se induce cuando la piel se expone al ambiente. El objetivo fue cuantificar ambas pigmentaciones en una muestra de población mexicana, y analizar su relación con el género, edad y fototipo.
Métodos:
Se evaluaron 259 personas durante un periodo invernal. La colorimetría cutánea se obtuvo mediante espectrometría de reflectancia difusa utilizando las coordenadas de la Comisión Internacional de Iluminación. Se registraron los valores L*a*b* y se estimó el ángulo tipológico individual (ATI°) en frente, tórax, cuello, antebrazos y glúteos.
Resultados:
La pigmentación facultativa difirió de la constitutiva en los parámetros L*, a*, y ATIº. En hombres, los valores facultativos de L* y ATI° fueron menores. La pigmentación constitutiva fue similar entre sexos. Los fototipos III, IV y V muestran diferencias en L*, b* y ATI°. Los valores facultativos L*, a*, ATI° y el constitutivo a* se reducen al incrementarse la edad.
Conclusiones:
Se cuantificaron los tonos cutáneos de una muestra de población reconociéndose los valores para la piel blanca, morena clara y morena oscura. Se presenta un marco de referencia para estudios relacionados con la pigmentación cutánea en México.
... Eumelanin (brown or black in color) is the most common product in humans. However, in the presence of cysteine, eumelanin is converted to pheomelanin (red or yellow in color) (9,12,13). A combination, mainly of melanin and carotene, produces color in the skin, eyes and hair (13). ...
... However, in the presence of cysteine, eumelanin is converted to pheomelanin (red or yellow in color) (9,12,13). A combination, mainly of melanin and carotene, produces color in the skin, eyes and hair (13). Melanin can absorb broadband UV light and protects skin cells from UVB radiation (UVB R ) damage, thereby decreasing the risk of carcinogenesis. ...
Vitiligo is a skin disorder characterized by depigmentation of the skin due to a lack of melanin. This condition affects men and woman of all ages and its incidence is not restricted by ethnicity or region. Vitiligo is a multifactorial disease, in which melanocytes, which serve important functions in skin pigmentation and immune processes, are impaired. There is sufficient evidence that immunological and genetic factors are primarily responsible for the destruction and dysfunction of melanocytes. Therefore, genetic DNA sequence variants that participate in skin homeostasis, pigmentation and immune response regulation, as well as altered expression patterns, may contribute to the risk of developing vitiligo. The current review presented an overview of the mechanism of pigmentation and of currently known factors involved in depigmentation, as well as the classification, epidemiology, associated comorbidities, risk factors, immunopathogenesis and several genetic and molecular changes associated with vitiligo.
... While many physical characteristics are commonly distributed within and among groups, skin color is somewhat different. 24,25 This attribute is important to dermatology because it affects presentation and management of many cutaneous diseases. 1, 26 Approximately 10% of the variance in skin color occurs within racial/ genetic groups, and 90% occurs between groups. ...
... 33 Skin color is not specific to a racial group and the cutaneous biology of pigmentation processes such as post-inflammatory hyperpigmentation (PIH) is very similar in populations with distinct genetic backgrounds. 25 Thus, "skin color" is a term and a concept that is relevant to cutaneous biology and disease research, independent of racial background. ...
Skin disease occur worldwide, affecting people of all nationalities and all skin types. These diseases may have a genetic component and may manifest differently in specific population groups; however, there has been little study on this aspect. If population-based differences exist, it is reasonable to assume that understanding these differences may optimize treatment. While there is a relative paucity of information about similarities and differences in skin diseases around the world, the knowledge-base is expanding. One challenge in understanding population-based variations is posed by terminology used in the literature: including ethnic skin, Hispanic skin, Asian skin, and skin of color. As will be discussed in this article, we recommend that the first three descriptors are no longer used in dermatology because they refer to nonspecific groups of people. In contrast, "skin of color" may be used - perhaps with further refinements in the future - as a term that relates to skin biology and provides relevant information to dermatologists.
... Especially, the blood in the capillary contains hemoglobin. Skin color is mainly determined by two light-absorbing substances, melanin and hemoglobin (21). Arteries and veins in the subcutaneous tissue deliver nutrients to the skin and remove waste products, with a significant portion of this tissue comprising subcutaneous fat (22). ...
Introduction
Autonomic nervous system activity (ANSA) plays a crucial role in the physical condition experienced during exercise and prolonged physical activity. In other words, ANSA is related to exercise performance and physical condition. Therefore, it is important to continuously monitor ANSA during high-intensity and sustained exercise. To this end, an uncomplicated and noncontact measurement system is preferable. Hence, in this study, we propose a method for the noncontact measurement of capillary contraction and dilation state, representative of ANSA, using a common commercial camera.
Methods
Specifically, we focused on alterations in the green value of facial video images, from which we derived the green-to-blue (G/B) ratio as an indicator of blood vessel dilation and contraction, and to facilitate assessment of their activity. We performed a validation experiment involving exercise tasks using an ergometer in 10 healthy adults (23 ± 1.6 years old). The G/B ratio shows the state of contraction and expansion of facial capillaries, and it was evaluated using heart rate as ground truth data of the fluctuation of autonomic nerve activity.
Results
We observed an increase in heart rate with decreased G/B ratio during exercise in all subjects. Postexercise, the heart rate decreased but the G/B ratio increased.
Discussion
During exercise, characterized by dominant sympathetic NSA, the G/B ratio decreased, and recovered after exercise when parasympathetic NSA was dominant. In this way, noncontact evaluation of ASNA was achieved by using the G/B ratio. In the future, this measurement system will be applied to functional tests for heat acclimation.
... The skin color is due to the combination of skin chromophores red (oxyhaemoglobin), blue (deoxygenated haemoglobin), and brown (melanin) (Ortonne, 2012). Fortunately, a variation in skin color due to chromophores concentration variation is not always related to severe pathological conditions but it can be related to skin response to some external stimuli, such as the application of topical products. ...
Reflectance spectroscopy has emerged as a powerful analytical technique in the field of dermatology, offering a non-invasive strategy to assess several cutaneous properties and skin response to topical products. By analyzing reflected light across different wavelengths, reflectance spectroscopy allows the quantification of cutaneous parameters, such as erythema index and melanin content. Moreover, this analytical technique enables the monitoring of any changes in skin physiology facilitating the assessment of long-term effects of topical products as well as predicting cutaneous diseases. This review provides an overview of the application of reflectance spectroscopy in investigating skin properties and reaction to topical applied products, including both pharmaceutical and cosmetic formulations, thereby aiding in the development of personalized solutions tailored to individual needs.
... The epidermis is composed mainly of two different cells: The first part is keratinocytes, which are located in the upper layer (constituting approximately 95% of cells), and the second is melanocytes, which are located in the basal layer [3]. Melanin is a pigment and a dominant factor in deciding human skin color [4], which is produced by melanocytes in a process called melanogenesis [5]. The excessive production of melanin results in darker patches on the skin than the normal surrounding skin, which is hyperpigmentation [6]. ...
Concerns about hyperpigmentation and skin appearance have led to increasing research into the prevention and altering of skin pigmentation. Natural compounds may be of interest in the search for skin-lightening actives. Protopanaxadiol (PPD), a gut microbiome-induced ginseng metabolite, has been reported to have anti-melanogenic effects. This study aimed to evaluate the antioxidative and anti-melanogenic effects of PPD-enriched rice seed extracts on melan-a cells. The antioxidant and cytotoxicity activities of the extracts were investigated in melan-a cells before measuring their responses to melanogenic activities. The extracts significantly enhanced the antioxidant potency compared with normal rice seed extract. PPD-enriched rice seed extracts (i) significantly downregulated microphthalmia-associated transcription factor, which led to a reduction in tyrosinase and tyrosinase-related protein-1 and -2, (ii) decrease in the cellular tyrosinase activity and melanin content, (iii) reduction in the number of melanin-containing cells, (iv) promotion of melanogenesis downregulators, phosphorylation of extracellular signal-regulated kinase 1/2 and protein kinase B, and (v) downregulation of the phosphorylated p38 mitogen-activated protein kinase and melanin synthesis. These results indicate the feasibility of PPD-enriched rice seed extracts as a novel agent for suppressing melanogenesis and controlling hyperpigmentation.
... Macroscopic assessment of bruises demonstrates the presence of hemoglobin near the surface of the skin shown in red color, but if the hemoglobin is deeper in the tissue, it will be shown in blue. This effect is related to the Rayleigh's bursting phenomenon, the skin absorption coefficient, and the visual interpretation system [7,8,9,10]. ...
Bruises are common skin lesions that occur as the force hits the skin, but integrity of the skin is not impaired. Their significance is important in forensic expert reports in determining the time of death in many cases of domestic violence or child abuse. The aim of this study was to present the differences between bruises with different time of origin by evaluation of their morpho-histological characteristics. The study included 60 human skin samples divided into control and experimental groups A, B, C, D. The experimental group A included bruised human skin samples with <1day old bruises, experimental group B included bruised human skin samples with 1-3 days old bruises, experimental group C included bruised human skin samples with 3-7 days old bruises and experimental group D included bruised human skin samples with 7-14 days old bruises. Paraffin sections of the skin were stained with Hematoxylin-eosin, Giemsa, Perl’s Prussian Blue, Masson-Goldner methods of staining and application of anti-HO-1 antibody. All paraffin sections were evaluated by light microscopy and photodocumented. Our results have shown changes in color in bruises with different age due to infiltration with different immune cells and metabolism of extracellular hemoglobin. Granulocyte infiltration is seen shortly after the initiation of the bruise, while after few days of initiation, usually 1-3, there is macrophage infiltration in the field of bleeding. Presence of macrophages in the field of bleeding increases as bruises age. These histological characteristics appear in direction of healing the bruise, together with phagocytosis of the erythrocytes and removing the tissue debris. Keywords: bruises, time of origin, morpho-histological characteristics, microscopic analysis
... Melanin is a pigment manufactured by melanocytes in the epidermal skin layer. It also contributes to skin color [1]. Pigmentation protects the skin from ultraviolet (UV) radiation damage and environmental pollutants [2]. ...
Fermentation is a traditional technique used to increase nutrients, flavonoids, vitamins, minerals, and the flavor of raw materials. In this study, adlay bran was fermented by Lactobacillus brevis MJM60390 (FAB), and the anti-melanogenic effect was investigated. The results demonstrated that FAB significantly suppressed melanin accumulation in mouse melanogenic B16F10 cells, and the activity was higher than non-fermented adlay bran (NFAB). The molecular mechanism study showed that FAB inhibited melanin synthesis by suppressing the gene expression of melanocortin 1 receptor (Mc1r), melanocyte-inducing transcription factor (Mitf), tyrosinase (Tyr), tyrosinase-related protein-1 (Trp-1), and tyrosinase-related protein-2 (Trp-2) genes. Western blotting analysis showed that FAB strongly decreased the expression of Tyr, Trp-1, and Trp-2 compared to NFAB. Furthermore, phenolic compounds such as gallic acid, p-coumaric acid, ferulic acid, and sinapic acid, which are known for their anti-melanogenic effects, were significantly increased in FAB compared with NFAB. These findings suggest that FAB holds great potential as an anti-melanogenic agent and can be used for the development of whitening cosmetics.
... However, histological observations clearly show that melanosomes are scarce in the Malpighian layer and in the superficial cornified (horny) layer, whereas they are concentrated in the basal layer. This highly suggests that melanin and melanosomes are degraded as melanosome-laden keratinocytes exit the basal layer to undergo terminal differentiation [24]. The mechanism(s) by which melanosomes are degraded remain to be further elucidated. ...
Human skin is a highly efficient self-renewing barrier that is critical to withstanding environmental insults. Undifferentiated keratinocyte stem cells reside in the basal layer of the epidermis and in hair follicles that continuously give rise to progenies ensuring epidermal turnover and renewal. Ultraviolet (UV) radiation is a proven cause of skin keratinocyte cancers, which preferentially occur at sun-exposed areas of the skin. Fortunately, melanocytes produce melanin that is packaged in specific organelles (termed melanosomes) that are then delivered to nearby keratinocytes, endowing the recipient cells with photoprotection. It has long been thought that melanosome transfer takes place stochastically from melanocytes to keratinocytes via an as-yet-unrecognized manner. However, recent studies have indicated that melanosomes are distributed regionally in the basal layer of the skin, affording localized intensive photoprotection for progenitor keratinocytes and stem cells that reside in the microenvironment of the basal epidermis. In this review, we summarize current knowledge about molecular and cellular mechanisms that are responsible for the selective transfer and exclusive degradation of melanosomes in the epidermis, emphasizing implications for skin carcinogenesis.
... A cor da pele humana é prioritariamente dependente da produção de melanina, um pigmento castanho denso, o qual assume o aspecto acastanhado, quanto mais concentrado [4,5]. ...
Introduction: Polypodium leucotomos has some properties on the human body and mainly on the
skin. Being used as an adjuvant in the treatment and prevention of various pathologies such as melasma.
Objective: This study reviews the literature to identify the impact of Polypodium leucotomos in the
treatment of melasma. Material and Method: Analysis of data in the bases of academic articles in health:
Scielo, Medline, Lilacs with the descriptors in Health Sciences (DeCS): Phytotherapy; Melasma and
dietary supplements, with no year restrictions, in Portuguese and English. Where the eligibility criteria
were considered for inclusion, the original articles clinical trials, case control, systematic review and metaanalysis, animal studies, in vitro and adult patients, Result: 31 studies were found, 13 were included and 18
excluded by do not meet the eligibility criteria. Conclusion: The literature survey allowed us to conclude
that among the various properties of Polypodium leucotomos, the antioxidant, anti-inflammatory,
photoprotective and immunomodulatory properties stand out, having a considerable impact on improving
the quality of life of melasma patients, being a whitening factor and protective in the disease. However,
more randomized clinical studies should be carried out to confirm its effects and establish the appropriate
dose as an adjunct to the treatment of melasma.
... Human skin color is affected by the quantities of three pigments: melanin, hemoglobin, and carotene. In particular, melanin plays the most important role [1][2][3]. Melanin is an indole substance produced by the enzymatic oxidation of tyrosine. Melanin is a key pigment that absorbs ultraviolet radiation, serving as a biological defense for the skin. ...
Several resorcinol derivatives were synthesized and their effects on the survival rate of B16 murine melanoma cells, melanin production, and tyrosinase activity were investigated with an aim to evaluate their skin whitening effect. Twelve resorcinol derivatives were synthesized by esterification with three functional groups (L-ascorb-6-yl, ethyl, and glyceryl) linked via four alkyl chains of varying lengths (n = 2–5) at the 4-position. The structures of the 12 resorcinol derivatives were confirmed by Nuclear Magnetic Resonance (NMR). The derivatives were added to B16 murine melanoma cells and the melanin contents in the cells and culture medium were measured. To measure the tyrosinase activity, the substrate L-DOPA was added to a mushroom-derived tyrosinase solution, and the inhibition of the tyrosinase activity was determined. At 10 µM, the resorcinol derivatives did not affect the survival of the B16 murine melanoma cells, but the melanin content was reduced. At 1 µM, the derivatives significantly inhibited the tyrosinase activity in the mushroom-derived tyrosinase solution. A plot of the inhibitory effect on melanin production against the cLogP value for each resorcinol derivative indicated that the highest inhibition occurred at a cLogP value of approximately 2. Therefore, these resorcinol derivatives are expected to serve as effective skin whitening agents.
... Dyschromia is the abnormal presence in the skin of a pigment of exogenous or endogenous origin. [9] In the aging process of skin, oxidative damage in cells and tissues caused by a disturbance in the balance between the production of reactive oxygen species (ROS) and the natural antioxidant defences. In the skin, free radical damage can cause deterioration of the stratum corneum and supportive connective tissue, resulting in decreased elasticity and resilience. ...
... Several synthetic tyrosinase inhibitors have been reported in the literature, such as kojic acid, which is widely used as a skin-whitening agent in cosmetics. However, the use of this compound in this context has been associated with several serious side effects, including erythema and contact dermatitis [11,12]. Further research is therefore required to identify natural and biocompatible tyrosinase inhibitors that can be used as whitening agents and antibrowning agents in the cosmetic and food industries. ...
Torreya grandis Fort. ex Lindl. is a plant belonging to the Taxaceae family and Torreya grandis cv. Merrillii is the only grafted and thoroughbred species belonging to this species. In this study, we extracted five different seed oils, including T. grandis seed oil (TGSO), T. grandis “Xiangyafei” seed oil (XYSO), T. grandis “Zhimafei” seed oil (ZMSO), T. grandis “Majus”seed oil (TGMSO), and T. grandis “cunguangfei” seed oil (CGSO) using physical pressure. The resulting extracts were analyzed to determine their fatty acid composition, antioxidant activity, and inhibitory activity towards tyrosinase. The results of the antioxidant activity assays revealed that XYSO and ZMSO exhibited much greater DPPH radical scavenging activity and ferric reducing power than TGSO. Notably, all five of the seed oils showed dose-dependent inhibitory activity towards tyrosinase. XYSO and TGSO gave the highest activities of all of the seed oils tested in the current study against monophenolase and diphenolase, with IC 50 values of 227.0 and 817.5 μ g/mL, respectively. The results of this study show that wild TGSOs exhibit strong antioxidant and tyrosinase inhibition activities. These results therefore suggest that wild TGSOs could be used as a potential source of natural antioxidant agents and tyrosinase inhibitors.
... 4 Histological observations show that melanin granules are scarce in the Malpighian layer and the superficial cornified (horny) layer, whereas they are abundant in the basal layer. This suggests that melanin and melanosomes are degraded during their transit upward to the surface of the epidermis 10,11 . The prevalent mode of transfer between MCs and KCs through exo-/endo-cytosis of the melanosome core (termed melanocore) has been considered as the main manner in physiological context, melanocores in the recipient KCs actually reveal the absence of a melanosomal outer membrane 12 . ...
Melanosomes are membrane-bound intracellular organelles that are uniquely generated by melanocytes (MCs) in the basal layer of human epidermis. Highly pigmented mature melanosomes are transferred from melanocytes (MCs) to keratinocytes (KCs), and then positioned in the supra-nuclear region to ensure protection against ultraviolet radiation (UVR). However, the molecular mechanism underlying melanosome (or melanin pigment) transfer remains enigmatic. Emerging evidence shows that exo-/endo-cytosis of the melanosome core (termed melanocore) has been considered as the main transfer manner between MCs and KCs. As KCs in the skin migrate up from the basal layer and undergo terminal differentiation, the melanocores they have taken up from MCs are subjected to degradation. In this study, we isolated individual melanocores from human MCs in culture and then induced their destruction/disruption using a physical approach. The results demonstrate that the ultrastructural integrity of melanocores is essential for their antioxidant and photoprotective properties. In addition, we also show that cathepsin V (CTSV), a lysosomal acid protease, is involved in melanocore degradation in calcium-induced differentiated KCs and is also suppressed in KCs following exposure to UVA or UVB radiation. Thus, our study demonstrates that change in the proportion of melanocores in the intact/undegraded state by CTSV-related degradation in KCs affects photoprotection of the skin.
... Melanin is a polymeric pigment found in most organisms and affects coloration of the skin, hair, and eye in humans and coat color in animals (Jimbow et al. 1976;Maroñas et al. 2015;Ortonne 2012). It generally includes eumelanin and pheomelanin. ...
Zebrafish phosvitin-derived peptide Pt5, consisting of the C-terminal 55 residues of phosvitin, has been shown to have an antimicrobial-immunomodulatory activity comparable to phosvitin. Here, we showed clearly that Pt5 had the capacity to inhibit tyrosinase (TYR) activity and melanin biosynthesis, and this inhibition was independent of cell proliferation and cytotoxic effects. Incubation of fluorescein isothiocyanate (FITC)-labeled Pt5 with B16F10 melanoma cells revealed that Pt5 was localized in the cytoplasm of the cells. In addition, Pt5 inhibited the expression of TYR, tyrosinase-related protein-1 (TRP-1), tyrosinase-related protein-2 (TRP-2), and microphthalmia-associated transcription factor (MITF) in B16F10 melanoma cells and reduced the intracellular cyclic adenosine monophosphate (cAMP) concentration in the cells, but it did not affect the cellular contents of pERK1/2 and β-catenin, suggesting that Pt5 regulates melanin biosynthesis via cAMP signaling pathway rather than Wnt and MAPK pathways. Collectively, these data indicate that Pt5 has the potential to be used as a melanogenesis inhibitor in medical and cosmetic industry, a novel role ever reported.
... In humans, dopaquinone is converted by a cascade of cyclization and polymerization steps into melanin [10]. In many cultural settings irregular melanin pigmentation is considered as an esthetic disadvantage [11,12]. As a result, several depigmenting modalities are being investigated for their efficacy in treating skin hyperpigmentary lesions [13]. ...
... Furthermore, it has been suggested that the epidermal melanin unit not only consists of melanocytes and keratinocytes, but also involves Langerhans cells present in the epidermis that also exist in the papillary dermis (Jimbow et al. 1991;Nordlund 2007). Several human pigmentation disorders such as ceruloderma, a type of dermal melanosis, and forms of post-inflammatory hyperpigmentation are due to defects in the dermal layer, indicating that human pigmentation is indeed not exclusively regulated in the epidermis, but also in the dermis (Ortonne 2012). Additionally, a melanocyte reservoir for hair and skin (re-)pigmentation consisting of melanocyte stem cells (MelSCs) is located in specific compartments of hair follicles in the dermis (Nishimura 2011). ...
In the International Visible Trait Genetics (VisiGen) Consortium, we investigated the genetics of human skin color by combining a series of genome-wide association studies (GWAS) in a total of 17,262 Europeans with functional follow-up of discovered loci. Our GWAS provide the first genome-wide significant evidence for chromosome 20q11.22 harboring the ASIP gene being explicitly associated with skin color in Europeans. In addition, genomic loci at 5p13.2 (SLC45A2), 6p25.3 (IRF4), 15q13.1 (HERC2/OCA2), and 16q24.3 (MC1R) were confirmed to be involved in skin coloration in Europeans. In follow-up gene expression and regulation studies of 22 genes in 20q11.22, we highlighted two novel genes EIF2S2 and GSS, serving as competing functional candidates in this region and providing future research lines. A genetically inferred skin color score obtained from the 9 top-associated SNPs from 9 genes in 940 worldwide samples (HGDP-CEPH) showed a clear gradual pattern in Western Eurasians similar to the distribution of physical skin color, suggesting the used 9 SNPs as suitable markers for DNA prediction of skin color in Europeans and neighboring populations, relevant in future forensic and anthropological
investigations.
Electronic supplementary material
The online version of this article (doi:10.1007/s00439-015-1559-0) contains supplementary material, which is available to authorized users.
... Skin color is determined by various factors including melanin content, oxygenation state of hemoglobin in capillary vessels, carotenoid content, water content, and organization of collagen fibers in the dermis. Among these factors, melanin is the major determinant of skin color [32]. In this context, understanding the mechanisms involved in melanogenesis is of great interest pharmaceutically and cosmetically. ...
Abnormal changes in skin color induce significant cosmetic problems and affect quality of life. There are two groups of abnormal change in skin color; hyperpigmentation and hypopigmentation. Hyperpigmentation, darkening skin color by excessive pigmentation, is a major concern for Asian people with yellow-brown skin. A variety of hypopigmenting agents have been used, but treating the hyperpigmented condition is still challenging and the results are often discouraging. Panax ginseng has been used traditionally in eastern Asia to treat various diseases, due to its immunomodulatory, neuroprotective, antioxidative, and antitumor activities. Recently, several reports have shown that extract, powder, or some constituents of ginseng could inhibit melanogenesis in vivo or in vitro. The underlying mechanisms of antimelanogenic properties in ginseng or its components include the direct inhibition of key enzymes of melanogenesis, inhibition of transcription factors or signaling pathways involved in melanogenesis, decreasing production of inducers of melanogenesis, and enhancing production of antimelanogenic factor. Although there still remain some controversial issues surrounding the antimelanogenic activity of ginseng, especially in its effect on production of proinflammatory cytokines and nitric oxide, these recent findings suggest that ginseng and its constituents might be potential candidates for novel skin whitening agents.
... In humans, melanocytes make up between 5% and 10% of the basal epithelial cells with around 1000-2000 melanocytes per square millimeter of skin. 24,72,73 . ...
Porcine skin is commonly used as a model for human skin injury and as a source material for biologic scaffold materials. Although remarkable similarities between porcine and human skin exist, regional anatomic variations present in human skin are also present in porcine skin. The objective of the present study was to evaluate the structure of porcine skin from 11 different anatomic regions in the Whiteshire Hamroc breed. Both qualitative and quantitative methods were used, with emphasis upon epidermal and dermal thickness, hair follicle density and collagen and elastin composition and distribution. The results showed that significant regional differences in skin histology exist particularly with respect to the thickness of the dermis and epidermis and the amount of collagen and elastin within each tissue. Differences were also seen in the distribution of type I and type III collagen within the dermis. Therefore while porcine skin shares many similarities with human skin, distinct regional differences in composition and morphology exist. This study highlights the importance of appreciating these regional differences to avoid misinterpretation of experimental results when using porcine skin as a human analogue.
Melanin is responsible for skin color. Hyperpigmentation, characterized by excessive darkening of the skin, may cause significant cosmetic issues and impact quality of life. Exposure to ultraviolet radiation has led to widespread photo-aging across all skin types. Through their interaction with endogenous photosensitizers, ultraviolet rays produce reactive oxygen species and free radicals and causing cumulative structural and physiological damage to skin. This results in sunburn, wrinkles, hyperpigmentation and skin cancer. Topical antioxidants may protect the skin from environmental damage. Certain plant extracts have shown promising antioxidant and anti-melanogenic properties. Therefore, the current study was conducted to formulate and evaluate effectiveness of herbal cream containing extracts of liquorice, ginseng and amla. Among the eight batches tested, batch F3 containing amla (0.5%), liquorice (3%) and ginseng (2%) demonstrated excellent homogeneity, washability, spreadability and pH, along with outstanding free radical scavenging activity (85.9%) and stability. Moreover, positive results of the patch test indicate the safety of the formulation.
In this study, we aimed to evaluate color differences of the skin paddle in autologous breast reconstruction performed using the deep inferior epigastric artery perforator (DIEP) flap and the profunda artery perforator (PAP) flap. The primary focus was to compare the color match between the reconstructed breast skin and the donor-site skin, to achieve optimal esthetic results.
A retrospective analysis was performed on patients who had undergone unilateral breast reconstruction with a DIEP flap or a PAP flap between January 2020 and December 2022. The colors were captured using a digital camera and analyzed using Adobe Photoshop 2024 software. The L*, a*, and b* coordinates were used. The International Commission on Illumination Delta E 2000 (CIEDE2000) score was used to quantify color differences, comparing skin tones of the unaffected breast, DIEP flap, PAP flap, abdomen, and medial thigh.
A total of 125 patients were analyzed. The DIEP flap demonstrated a closer color match to the native breast skin compared with the PAP flap (CIEDE2000 scores, 5.29 vs. 8.69, p < 0.01). No significant difference in color deformity with time was found between the DIEP flap and the PAP flap (CIEDE2000 scores, 5.61 vs. 8.25, p = 0.17).
Our findings suggest that the DIEP flap results in a more favorable color match for breast reconstruction than the PAP flap, enhancing esthetic outcomes. These results underscore the importance of considering skin color matching in flap selection for breast reconstruction surgery.
In contemporary cosmetics, botanicals and natural extracts remain vital components and have been used in formulations since ancient times. However, natural and botanical products can still be highly effective in treating aging skin, even though they are becoming more technological and invasive. Many natural products are being elucidated through biochemical mechanisms of action, correlating with traditional uses of many plants for skin benefits. Different formulations of medicinal and pharmaceutical substances incorporate synthetic molecules and chemicals, which is the principal cause of dermal toxicity. Consumers' awareness about personal health and safety and the desire for safer cosmetics free of harmful chemicals have driven the cosmetics and personal care market toward natural ingredients. The commercialization of natural products derived from herbs and bees is possible. Our purpose is to present a comprehensive and critical review emphasizing the benefits of natural products for skin care, women's purchasing patterns, and updated information about natural products.
Background:
Botulinum toxin injection is a common cosmetic procedure often used to treat dynamic wrinkles, but it has also been observed to have a lightening effect on the skin. It is thought that this lightening effect develops due to muscle innervation blockage; however, the change in the amount of melanin levels has not been quantified.
Method:
Thirty-one patients who presented to the dermatology clinic of a tertiary hospital for botulinum toxin injection for wrinkle treatment were included in the study. A standard dose of botulinum toxin was injected to each patient's forehead, glabellar, and crow's feet region, and then the melanin index (MI) was measured with the Mexameter® MX 18 (Courage + Khazaka Electronic, Köln).
Results:
After botulinum toxin treatment, a statistically significant decrease was found in the forehead and upper face MI. The upper face total baseline MI was significantly lower in the Glogau 1 group than in the Glogau 2 group (P = 0.033). The forehead 15th day MI was significantly lower in the Glogau 1 group than in the Glogau 2, 3, and 4 groups (P = 0.030).
Discussion:
Botulinum toxin application to healthy skin for wrinkle treatment can cause facial skin lightening by reducing MI. It was also remarkable that this decrease was more pronounced in the forehead, which is a region that is particularly vulnerable to sun exposure, compared to other regions. Younger people, who are included in the Glogau type 1 group, may benefit more from this lightening effect.
Aims
Overexpression of tyrosinase in humans causes an increase in melanin production in the skin, which can result in hyperpigmentation consequences such as freckles, melasma, age spots, and melanoma. Free radicals also play a significant role in the increase of the biosynthesis of melanin.
Background
Tyrosinase inhibitors capable of inhibiting the biosynthesis of melanin are used currently in various hyperpigmentation and cosmetic agents to control the formation of freckles. Several synthetic tyrosinase inhibitors have been associated with several serious side effects. Also, synthetic antioxidants had many toxicological side effects including carcinogenicity. There is an increasing interest in the search for natural tyrosinase inhibitors and antioxidant agents.
Objective:
The objective of this study is to evaluate total polyphenol and flavonoid contents as well as examine the antioxidative and tyrosinase inhibitory effects of A. sicula L. aqueous extract.
Methods
Antioxidant activities evaluated using superoxide radical scavenging and reducing power methods. tyrosinase inhibitory assay was used to determine anti-hyperpigmentation.
Results
The results showed that this extract was rich in total polyphenols (58.01±1.18 micrograms of gallic acid equivalents per milligrams of extract) and flavonoids (17.91±1.81 micrograms quercetin equivalents per milligram of extract). A. sicula L. aqueous extract was capable of scavenging free radicals (IC50 =11.87±0.13 μg/mL) and acts as a strong reducing agent (A 0.5= 6.37±0.42µg/mL). A. sicula L. had a potent tyrosinase inhibitory potential (IC50= 12.63±1.15 μg/mL), which was higher compared to kojic acid as standard (IC50= 25,23±0,78 μg/mL, P <0.001). These results support that A. sicula L. could be a new source of antioxidant and cosmetic use. Further studies focusing on the isolation and characterization of active principles of antioxidant and tyrosinase inhibitory activities are needed.
Die Vitiligo ist eine der häufigsten Hypopigmentierungen und kann zur Stigmatisierung Betroffener führen. In der klassischen Therapie haben topische Kortikosteroide und Kalzineurinhemmer in Kombination mit Schmalband-UV-B-Bestrahlung die größte Bedeutung. Doch mit Antioxidanzien, Immunmodulatoren und Januskinaseinhibitoren zeichnen sich neue Behandlungsmöglichkeiten ab - sowohl einzeln als auch kombiniert mit UV- oder Lasertherapie.© shurkin_son / stock.adobe.com (Symbolbild mit Fotomodell) © shurkin_son / stock.adobe.com (Symbolbild mit Fotomodell)
As the largest organ in our body, the skin acts as a barrier against external stress and damages. There are various cell types of skin, such as keratinocytes, melanocytes, fibroblasts, and skin stem cells. Korean ginseng, which is one of the biggest distributions of ginseng worldwide, is processed into different products, such as functional food, cosmetics, and medical supplies. This review aims to introduce the functional role of Korean ginseng on different dermal cell types, including the impact of Korean ginseng in anti-photodamaging, anti-inflammatory, anti-oxidative, anti-melanogenic, and wound healing activities, etc. We propose that this information could form the basis of future research of ginseng-derived components in skin health.
Background:
Hyperpigmentation following ultraviolet irradiation has cosmetic concerns. Botulinum toxin type A can favorably affect skin pigmentation. However, the mechanism of skin pigmentation is unclear.
Methods:
In vitro, human epidermal melanocytes were co-cultured with human keratinocytes. After cells were treated with botulinum toxin type A, cell morphology, proliferation, and dendricity were analyzed, and immunofluorescence, tyrosinase activity, and melanin contents were determined. To evaluate the effect of botulinum toxin type A on ultraviolet B-irradiated mouse skin, ultraviolet B alone was applied to one side of the back of each mouse as a control, whereas ultraviolet B plus injection of botulinum toxin type A was applied to the contralateral side. Skin pigmentation, histology, and the number of dihydroxyphenylalanine-positive melanocytes were evaluated. The L* colorimeter value was measured. Enzyme-linked immunosorbent assay determinations of basic fibroblast growth factor, interleukin-1 alpha, and prostaglandin E2 were performed.
Results:
Immunohistochemical staining revealed botulinum toxin type A in the cytoplasm of melanocytes and in the positive control. In vitro, melanocyte dendricity and melanin contents were decreased slightly but significantly (p < 0.05) after botulinum toxin type A treatment. In vivo, botulinum toxin type A suppressed skin pigmentation. The number of dihydroxyphenylalanine-positive melanocytes was also significantly lower than in the control side. Tyrosinase activity and melanin content were also significantly reduced (p < 0.05). Botulinum toxin type A also significantly reduced the amounts of basic fibroblast growth factor, interleukin-1 alpha, and prostaglandin E2 (all p < 0.05).
Conclusion:
Botulinum toxin type A can suppress epidermal melanogenesis through both direct and indirect mechanisms.
Background:
Hyperpigmentation, mainly following UV-irradiation, can cause major cosmetic concerns. Human adipose tissue-derived stem cells (ASCs) have been reported to serve as whitening agents through a paracrine effect. However, there have been few reports on the direct effects of ASCs on skin pigmentation following UVB-irradiation.
Methods:
To evaluate the effect of ASCs on UVB-irradiated mouse skin, UVB-irradiation alone was applied to one side of the backs of mice (melanin-processing hairless mouse, HRM-2) as a control, and UVB-irradiation plus injection of ASCs was applied to the contralateral side. Skin pigmentation and histology were evaluated and the number of DOPA-positive melanocytes in the mouse skin was counted. The absolute value of ΔL* via a colorimeter was measured to evaluate the degree of skin pigmentation. The effects of ASCs on the melanogenic activities of mouse skin were examined by measuring the tyrosinase activity and the melanin contents in the epidermis of the mouse skin.
Results:
Skin pigmentation was suppressed in the ASC-injected side. Moreover, the change in skin thickness following UVB irradiation was reduced in the ASC-injected side. The number of DOPA-positive melanocytes in the ASC-injected side (139 ± 18 cells/mm(2)) was significantly lower than that in the control side (239 ± 48 cells/mm(2)). The tyrosinase activity (67.4 ± 9.8% of that of the control side) and melanin content (63.4 ± 5.7% of that of the control side) of the ASC-injected side were also significantly reduced.
Conclusions:
Collectively, these results suggest that ASCs injected subcutaneously into the backs of mice can attenuate tanning following UVB-irradiation, through suppression of tyrosinase activity.
Skin is frequently exposed to a variety of environmental and chemical agents that accelerate ageing. External stress such as UV radiations (UVR) and environmental pollutants majorly deteriorate the skin morphology, by activating certain intrinsic factors such as Reactive Oxygen Species (ROS) which trigger the activation of Matrix Metalloproteinases (MMPs) and inflammatory responses hence damaging the extracellular matrix (ECM) components. To counter this, an exogenous supply of anti-oxidants, is required since the endogenous anti-oxidant system cannot alone suffice the need. Bio-prospecting of natural resources for anti-oxidants has hence been intensified. Immense research is being carried out to identify potential plants with potent anti-oxidant activity against skin ageing. This review summarizes the major factors responsible for premature skin ageing and the plants being targeted to lessen the impact of those.
Copyright © 2014 Elsevier B.V. All rights reserved.
Dyschromias are becoming a more common concern among patients, particularly among persons of color. There are a variety of treatments, including more novel agents for dyschromias. Evaluating common agents prescribed among various races may prompt efforts to enhance care for dyschromias in patients of color.
To determine whether racial or ethnic groups are treated differently for dyschromia. The secondary objective is to discover the main treatments used and determine trends over time in demographics.
We searched the 1993-2010 National Ambulatory Medical Care Survey (NAMCS) for visits associated with a diagnosis of dyschromia (ICD-9 codes 709.00 or 709.09). The demographics and leading treatments were tabulated, and trends over time were assessed by linear regression.
There were about 24.7 million visits for dyschromia over the 18-year period. Among 5,531,000 patients with the sole diagnosis of dyschromia, there were 2,800 visits from females and 1,200 visits from males per 100,000 population. Females were more likely to receive prescription combination therapy for dyschromia than males by a ratio of 10 to 1. Leading treatments overall prescribed by dermatologists included hydroquinone, topical corticosteroids, and retinoids. Asians were 27% more likely to receive a combination therapy than non-Asians. African Americans and Hispanics were less likely to have a procedure performed for dyschromia.
Data are based on a number of ambulatory care visits, which does not allow direct estimation of prevalence.
Dyschromia is a significant concern for many patients, and this is especially true among patients of color. Treatment for dyschromia is influenced by skin type, and thus ethnic or racial groups are treated differently. Studies have shown that combination therapy may offer better results than a single medication for hyperpigmentation disorders. Combination agents may be underutilized in African Americans and Hispanics for dyschromia.
J Drugs Dermatol. 2014;13(4):401-406.
Both hyperpigmentation and hypopigmentation may appear at birth or be acquired later. Different diseases can cause these alterations, and they are distinguished by the time of onset, location, size and the presence or absence of accompanying symptoms.
IntroductionClassification and PathophysiologyDiagnosis of Melanin Pigmentary Disorders