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Sample records for pigment melanin pattern

  1. Pigment Melanin: Pattern for Iris Recognition

    CERN Document Server

    Hosseini, Mahdi S; Soltanian-Zadeh, Hamid

    2009-01-01

    Recognition of iris based on Visible Light (VL) imaging is a difficult problem because of the light reflection from the cornea. Nonetheless, pigment melanin provides a rich feature source in VL, unavailable in Near-Infrared (NIR) imaging. This is due to biological spectroscopy of eumelanin, a chemical not stimulated in NIR. In this case, a plausible solution to observe such patterns may be provided by an adaptive procedure using a variational technique on the image histogram. To describe the patterns, a shape analysis method is used to derive feature-code for each subject. An important question is how much the melanin patterns, extracted from VL, are independent of iris texture in NIR. With this question in mind, the present investigation proposes fusion of features extracted from NIR and VL to boost the recognition performance. We have collected our own database (UTIRIS) consisting of both NIR and VL images of 158 eyes of 79 individuals. This investigation demonstrates that the proposed algorithm is highly s...

  2. Genetic Basis of Melanin Pigmentation in Butterfly Wings.

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    Zhang, Linlin; Martin, Arnaud; Perry, Michael W; van der Burg, Karin R L; Matsuoka, Yuji; Monteiro, Antónia; Reed, Robert D

    2017-04-01

    Despite the variety, prominence, and adaptive significance of butterfly wing patterns, surprisingly little is known about the genetic basis of wing color diversity. Even though there is intense interest in wing pattern evolution and development, the technical challenge of genetically manipulating butterflies has slowed efforts to functionally characterize color pattern development genes. To identify candidate wing pigmentation genes, we used RNA sequencing to characterize transcription across multiple stages of butterfly wing development, and between different color pattern elements, in the painted lady butterfly Vanessa cardui This allowed us to pinpoint genes specifically associated with red and black pigment patterns. To test the functions of a subset of genes associated with presumptive melanin pigmentation, we used clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 genome editing in four different butterfly genera. pale, Ddc, and yellow knockouts displayed reduction of melanin pigmentation, consistent with previous findings in other insects. Interestingly, however, yellow-d, ebony, and black knockouts revealed that these genes have localized effects on tuning the color of red, brown, and ochre pattern elements. These results point to previously undescribed mechanisms for modulating the color of specific wing pattern elements in butterflies, and provide an expanded portrait of the insect melanin pathway. Copyright © 2017 by the Genetics Society of America.

  3. A guide to the field of palaeo colour: Melanin and other pigments can fossilise: Reconstructing colour patterns from ancient organisms can give new insights to ecology and behaviour.

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    Vinther, Jakob

    2015-06-01

    Melanin, and other pigments have recently been shown to preserve over geologic time scales, and are found in several different organisms. This opens up the possibility of inferring colours and colour patterns ranging from invertebrates to feathered dinosaurs and mammals. An emerging discipline is palaeo colour: colour plays an important role in display and camouflage as well as in integumental strengthening and protection, which makes possible the hitherto difficult task of doing inferences about past ecologies, behaviours, and organismal appearance. Several studies and techniques have been presented in the last couple of years that have described ways to characterize pigment patterns. Here, I will review the available methods and the likely applications to understand past ecologies. A golden age of colourized dinosaurs and other animals is now dawning upon us, which may elucidate the nature of ancient predator prey interactions and display structures. © 2015 WILEY Periodicals, Inc.

  4. Interocular agreement in melanin and macular pigment optical density.

    NARCIS (Netherlands)

    Kanis, M.J.; Berendschot, T.T.J.M.; van Norren, D.

    2007-01-01

    Macular pigment (MP) and melanin possibly protect the macular area by absorbing blue light and acting as antioxidants. Because little is known about the interocular correlation of melanin, we determined its optical density (MOD) in both eyes of healthy subjects using fundus reflectometry. The measur

  5. Melanins: Skin Pigments and Much More—Types, Structural Models, Biological Functions, and Formation Routes

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    F. Solano

    2014-01-01

    Full Text Available This review presents a general view of all types of melanin in all types of organisms. Melanin is frequently considered just an animal cutaneous pigment and is treated separately from similar fungal or bacterial pigments. Similarities concerning the phenol precursors and common patterns in the formation routes are discussed. All melanins are formed in a first enzymatically-controlled phase, generally a phenolase, and a second phase characterized by an uncontrolled polymerization of the oxidized intermediates. In that second phase, quinones derived from phenol oxidation play a crucial role. Concerning functions, all melanins show a common feature, a protective role, but they are not merely photoprotective pigments against UV sunlight. In pathogenic microorganisms, melanization becomes a virulence factor since melanin protects microbial cells from defense mechanisms in the infected host. In turn, some melanins are formed in tissues where sunlight radiation is not a potential threat. Then, their redox, metal chelating, or free radical scavenging properties are more important than light absorption capacity. These pigments sometimes behave as a double-edged sword, and inhibition of melanogenesis is desirable in different cells. Melanin biochemistry is an active field of research from dermatological, biomedical, cosmetical, and microbiological points of view, as well as fruit technology.

  6. Isolation and characterization of melanin pigment from yesso scallop Patinopecten yessoensis

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    Sun, Xiujun; Wu, Biao; Zhou, Liqing; Liu, Zhihong; Dong, Yinghui; Yang, Aiguo

    2017-04-01

    Melanin is one of the essential compounds in the pigments of molluscan shells. However, the effects of melanin on color variations in molluscs are largely unknown. Our previous study suggests that Yesso scallop Patinopecten yessoensis might contain melanin pigment in the dark brown shell. We therefore isolated melanin from the pigmented shells using hydrochloric acid method, and characterized the types of melanin pigments by spectrophotometry. The purified melanin, which was verified by spectrophotometry scanning and HPLC analysis, showed the typical characteristics of melanin absorption spectra and HPLC chromatograms. The contents of pheomelanin and eumelanin in pigmented shells, which were determined by the linear standard curve of melanin at 405 nm and 350 nm absorbance, were 48.23 ± 1.350 and 157.65 ± 5.905 mg, respectively. The present results indicate that the brown-pigmented shells of scallops comprise approximately 76.6% of eumelanin and 23.4% of pheomelanin, which supports the presence of eumelanin-rich pigment in scallop shells. Therefore, the combination of hydrochloric acid extraction and spectrophotometric quantification is a rapid and efficient method to isolate and quantify melanin in shells. This will facilitate the melanin studies related to shell color polymorphism and the selective breeding of bivalves with different shell colors.

  7. Odontogenic Cyst with Verrucous Proliferation Exhibiting Melanin Pigmentation

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    Soni, Krupa Mehta; Ahmed, Junaid; Bhat, Keshava; Kottieth Pallam, Nandita; Lewis, Amitha Juanita

    2017-01-01

    Verrucous proliferation arising from odontogenic cysts is a rare entity. We report an unusual case of an infected odontogenic cyst with verrucous proliferation and melanin pigmentation in a 13-year-old male patient who presented with an intraoral swelling in relation to impacted teeth 26 and 27. The enucleated lesion was diagnosed as an odontogenic keratocyst and the patient died within two years of presentation due to multiple recurrences. The clinical, radiological, and microscopic features of the lesion are presented with an attempt to discuss the etiopathogenesis. The case hereby reported is uncommon with only eight cases reported in the literature. PMID:28409045

  8. Structural Characterization of Melanin Pigments from Commercial Preparations of the Edible Mushroom Auricularia auricula.

    Science.gov (United States)

    Prados-Rosales, Rafael; Toriola, Stacy; Nakouzi, Antonio; Chatterjee, Subhasish; Stark, Ruth; Gerfen, Gary; Tumpowsky, Paul; Dadachova, Ekaterina; Casadevall, Arturo

    2015-08-26

    Many of the most widely consumed edible mushrooms are pigmented, and these have been associated with some beneficial health effects. Nevertheless, the majority of the reported compounds associated with these desirable properties are non-pigmented. We have previously reported that melanin pigment from the edible mushroom Auricularia auricula can protect mice against ionizing radiation, although no physicochemical characterization was reported. Consequently, in this study we have characterized commercial A. auricula mushroom preparations for melanin content and carried out structural characterization of isolated insoluble melanin materials using a panel of sophisticated spectroscopic and physical/imaging techniques. Our results show that approximately 10% of the dry mass of A. auricula is melanin and that the pigment has physicochemical properties consistent with those of eumelanins, including hosting a stable free radical population. Electron microscopy studies show that melanin is associated with the mushroom cell wall in a manner similar to that of melanin from the model fungus C. neoformans. Elemental analysis of melanin indicated C, H, and N ratios consistent with 5,6-dihydroxyindole-2-carboxylic acid/5,6-dihydroxyindole and 1,8-dihydroxynaphthalene eumelanin. Validation of the identity of the isolated product as melanin was achieved by EPR analysis. A. auricula melanin manifested structural differences, relative to the C. neoformans melanin, with regard to the variable proportions of alkyl chains or oxygenated carbons. Given the necessity for new oral and inexpensive radioprotective materials coupled with the commercial availability of A. auricula mushrooms, this product may represent an excellent source of edible melanin.

  9. Synthesis of melanin-like pigments by Sporothrix schenckii in vitro and during mammalian infection.

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    Morris-Jones, Rachael; Youngchim, Sirida; Gomez, Beatriz L; Aisen, Phil; Hay, Roderick J; Nosanchuk, Joshua D; Casadevall, Arturo; Hamilton, Andrew J

    2003-07-01

    Melanin has been implicated in the pathogenesis of several important human fungal pathogens. Existing data suggest that the conidia of the dimorphic fungal pathogen Sporothrix schenckii produce melanin or melanin-like compounds; in this study we aimed to confirm this suggestion and to demonstrate in vitro and in vivo production of melanin by yeast cells. S. schenckii grown on Mycosel agar produced visibly pigmented conidia, although yeast cells grown in brain heart infusion and minimal medium broth appeared to be nonpigmented macroscopically. However, treatment of both conidia and yeast cells with proteolytic enzymes, denaturant, and concentrated hot acid yielded dark particles similar in shape and size to the corresponding propagules, which were stable free radicals consistent with identification as melanins. Melanin particles extracted from S. schenckii yeast cells were used to produce a panel of murine monoclonal antibodies (MAbs) which labeled pigmented conidia, yeast cells, and the isolated particles. Tissue from hamster testicles infected with S. schenckii contained fungal cells that were labeled by melanin-binding MAbs, and digestion of infected hamster tissue yielded dark particles that were also reactive. Additionally, sera from humans with sporotrichosis contained antibodies that bound melanin particles. These findings indicate that S. schenckii conidia and yeast cells can produce melanin or melanin-like compounds in vitro and that yeast cells can synthesize pigment in vivo. Since melanin is an important virulence factor in other pathogenic fungi, this pigment may have a similar role in the pathogenesis of sporotrichosis.

  10. Blood Supply--Susceptible Formation of Melanin Pigment in Hair Bulb Melanocytes of Mice

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    Shogo Maeda, MD

    2015-03-01

    Conclusions: Melanin pigment formation in the hair bulb melanocytes appeared to be susceptible to the blood supply, and melanocytosis was promoted in the follicles and in the epidermis of Kitl-Tg C57BL/6 mice.

  11. Melanin-Like Pigment Synthesis by Soil Bacillus weihenstephanensis Isolates from Northeastern Poland.

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    Drewnowska, Justyna M; Zambrzycka, Monika; Kalska-Szostko, Beata; Fiedoruk, Krzysztof; Swiecicka, Izabela

    2015-01-01

    Although melanin is known for protecting living organisms from harmful physical and chemical factors, its synthesis is rarely observed among endospore-forming Bacillus cereus sensu lato. Here, for the first time, we reported that psychrotolerant Bacillus weihenstephanensis from Northeastern Poland can produce melanin-like pigment. We assessed physicochemical properties of the pigment and the mechanism of its synthesis in relation to B. weihenstephanensis genotypic and phenotypic characteristics. Electron paramagnetic resonance (EPR) spectroscopy displayed a stable free radical signal of the pigment from environmental isolates which are consistent with the commercial melanin. Fourier transform infrared spectroscopy (FT-IR) and physicochemical tests indicated the phenolic character of the pigment. Several biochemical tests showed that melanin-like pigment synthesis by B. weihenstephanensis was associated with laccase activity. The presence of the gene encoding laccase was confirmed by the next generation whole genome sequencing of one B. weihenstephanensis strain. Biochemical (API 20E and 50CHB tests) and genetic (Multi-locus Sequence Typing, 16S rRNA sequencing, and Pulsed-Field Gel Electrophoresis) characterization of the isolates revealed their close relation to the psychrotrophic B. weihenstephanensis DSMZ 11821 reference strain. The ability to synthesize melanin-like pigment by soil B. weihenstephanensis isolates and their psychrotrophic character seemed to be a local adaptation to a specific niche. Detailed genetic and biochemical analyses of melanin-positive environmental B. weihenstephanensis strains shed some light on the evolution and ecological adaptation of these bacteria. Moreover, our study raised new biotechnological possibilities for the use of water-soluble melanin-like pigment naturally produced by B. weihenstephanensis as an alternative to commercial non-soluble pigment.

  12. Melanin-Like Pigment Synthesis by Soil Bacillus weihenstephanensis Isolates from Northeastern Poland.

    Directory of Open Access Journals (Sweden)

    Justyna M Drewnowska

    Full Text Available Although melanin is known for protecting living organisms from harmful physical and chemical factors, its synthesis is rarely observed among endospore-forming Bacillus cereus sensu lato. Here, for the first time, we reported that psychrotolerant Bacillus weihenstephanensis from Northeastern Poland can produce melanin-like pigment. We assessed physicochemical properties of the pigment and the mechanism of its synthesis in relation to B. weihenstephanensis genotypic and phenotypic characteristics. Electron paramagnetic resonance (EPR spectroscopy displayed a stable free radical signal of the pigment from environmental isolates which are consistent with the commercial melanin. Fourier transform infrared spectroscopy (FT-IR and physicochemical tests indicated the phenolic character of the pigment. Several biochemical tests showed that melanin-like pigment synthesis by B. weihenstephanensis was associated with laccase activity. The presence of the gene encoding laccase was confirmed by the next generation whole genome sequencing of one B. weihenstephanensis strain. Biochemical (API 20E and 50CHB tests and genetic (Multi-locus Sequence Typing, 16S rRNA sequencing, and Pulsed-Field Gel Electrophoresis characterization of the isolates revealed their close relation to the psychrotrophic B. weihenstephanensis DSMZ 11821 reference strain. The ability to synthesize melanin-like pigment by soil B. weihenstephanensis isolates and their psychrotrophic character seemed to be a local adaptation to a specific niche. Detailed genetic and biochemical analyses of melanin-positive environmental B. weihenstephanensis strains shed some light on the evolution and ecological adaptation of these bacteria. Moreover, our study raised new biotechnological possibilities for the use of water-soluble melanin-like pigment naturally produced by B. weihenstephanensis as an alternative to commercial non-soluble pigment.

  13. Applying photoacoustics to quantification of melanin concentration in retinal pigment epithelium (Conference Presentation)

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    Shu, Xiao; Zhang, Hao F.; Liu, Wenzhong

    2016-03-01

    The melanin in the retinal pigment epithelium (RPE) protects retina and other ocular tissues by photo-screening and acting as antioxidant and free radical scavenger. It helps maintain normal visual functions since human eye is subjected to lifelong high oxygen stress and photon exposure. Loss of the RPE melanin weakens the protection mechanism and jeopardizes ocular health. Local decrease in the RPE melanin concentration is believed to be both a cause and a sign of early-stage age-related macular degeneration (AMD), the leading blinding disease in developed world. Current technology cannot quantitatively measure the RPE melanin concentration which might be a promising marker in early AMD screening. Photoacoustic ophthalmoscopy (PAOM), as an emerging optical absorption-based imaging technology, can potentially be applied to measure the RPE melanin concentration if the dependence of the detectable photoacoustic (PA) signal amplitudes on the RPE melanin concentrations is verified. In this study, we tested the feasibility of using PA signal ratio from RPE melanin and the nearby retinal blood vessels as an indicator of the RPE melanin variation. A novel whole eye optical model was designed and Monte Carlo modeling of light (MCML) was employed. We examined the influences on quantification from PAOM axial resolution, the depth and diameter of the retinal blood vessel, and the RPE thickness. The results show that the scheme is robust to individual histological and illumination variations. This study suggests that PAOM is capable of quantitatively measuring the RPE melanin concentration in vivo.

  14. Sexual dimorphism in melanin pigmentation, feather coloration and its heritability in the barn swallow (Hirundo rustica).

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    Saino, Nicola; Romano, Maria; Rubolini, Diego; Teplitsky, Celine; Ambrosini, Roberto; Caprioli, Manuela; Canova, Luca; Wakamatsu, Kazumasa

    2013-01-01

    Melanin is the main pigment in animal coloration and considerable variation in the concentrations of the two melanin forms (pheo- and eumlanin) in pigmented tissues exists among populations and individuals. Melanin-based coloration is receiving increasing attention particularly in socio-sexual communication contexts because the melanocortin system has been hypothesized to provide a mechanistic basis for covariation between coloration and fitness traits. However, with few notable exceptions, little detailed information is available on inter-individual and inter-population variation in melanin pigmentation and on its environmental, genetic and ontogenetic components. Here, we investigate melanin-based coloration in an Italian population of a passerine bird, the barn swallow (Hirundo rustica rustica), its sex- and age-related variation, and heritability. The concentrations of eu- and pheomelanin in the throat (brown) and belly (white-to-brownish) feathers differed between sexes but not according to age. The relative concentration of either melanin (Pheo:Eu) differed between sexes in throat but not in belly feathers, and the concentrations in males compared to females were larger in belly than in throat feathers. There were weak correlations between the concentrations of melanins within as well as among plumage regions. Coloration of belly feathers was predicted by the concentration of both melanins whereas coloration of throat feathers was only predicted by pheomelanin in females. In addition, Pheo:Eu predicted coloration of throat feathers in females and that of belly feathers in males. Finally, we found high heritability of color of throat feathers. Melanization was found to differ from that recorded in Hirundo rustica rustica from Scotland or from H. r. erythrogaster from North America. Hence, present results show that pigmentation strategies vary in a complex manner according to sex and plumage region, and also among geographical populations, potentially

  15. Monte Carlo investigation on quantifying the retinal pigment epithelium melanin concentration by photoacoustic ophthalmoscopy.

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    Shu, Xiao; Liu, Wenzhong; Zhang, Hao F

    2015-10-01

    The retinal pigment epithelium (RPE) melanin plays an important role in maintaining normal visual functions. A decrease in the RPE melanin concentration with aging is believed to be associated with several blinding diseases, including age-related macular degeneration. Quantifying the RPE melanin noninvasively is therefore important in evaluating the retinal health and aging conditions. Photoacoustic ophthalmoscopy (PAOM), as an optical absorption-based imaging technology, can potentially be applied to measure variations in the RPE melanin if the relationship between the detected photoacoustic (PA) signal amplitudes and the RPE melanin concentrations can be established. In this work, we tested the feasibility of using PA signals from retinal blood vessels as references to measure RPE melanin variation using Monte Carlo (MC) simulation. The influences from PAOM axial resolution, the depth and diameter of the retinal blood vessel, and the RPE thickness were examined. We proposed a calibration scheme by relating detected PA signals to the RPE melanin concentrations, and we found that the scheme is robust to these tested parameters. This study suggests that PAOM has the capability of quantitatively measuring the RPE melanin in vivo.

  16. Pigmented epidermal cyst with dense collection of melanin: A rare entity - Report of a case with review of the literature.

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    Jayalakshmy, P S; Subitha, K; Priya, P V; Johnson, Gerald

    2012-05-01

    Epidermal cyst is a very common benign cystic lesion of the skin. It is usual to find ulceration of the lining epithelium, rupture of the cyst wall with chronic inflammation and foreign body giant cell reaction. But, it is very rare to see an epidermal cyst with marked accumulation of melanin pigment. Only a few cases of pigmented epidermal cyst with dense collection of melanin pigment have been published in the literature. Here, we are reporting a case of ruptured epidermal cyst with keratin granuloma formation and showing dense collection of melanin pigment.

  17. Experimentally induced melanin-like pigmentation (thesaurismosis) related to acorn ingestion in Nero Siciliano pigs.

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    Lanteri, Giovanni; Marino, Fabio; Liotta, Luigi; Stefano, Carmelo; Macrì, Battesimo

    2011-09-01

    In this study, an experimental challenge was carried out by feeding Nero Siciliano pigs with acorn to evoke melanin-like pigmentation and support the hypothesis that it is caused by ingested material. Twelve pigs were studied, 6 fed with acorns and 6 fed commercial feed. At slaughter, all the animals fed on acorns showed black discolouration of almost all lymph nodes. The lymph nodes were normal in size and shape. Histochemical tests performed on tissues allowed us to identify and differentiate the pigment. Immunohistochemical staining for macrophage markers showed macrophages containing a variable amount of melanin-like granules. Our data, and the well-known steps of melanin formation, confirm that swine enzymes could act on phenolic substances found in acorns.

  18. Duration of reappearance of gingival melanin pigmentation after surgical removal - A clinical study

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    Kaur Harjit

    2010-01-01

    Full Text Available Background: In dentistry, esthetics has a special place. Although gingival melanin pigmentation does not present a medical problem, clinicians are often faced with a challenge of achieving gingival esthetics. Materials and Methods: A method of de-epithelialization of the pigmented gingiva using Kirkland′s gingivectomy knife is described. Twenty patients who were conscious about their gingival melanin pigmentation were selected. The gingiva of the whole of the arch was abraded until the entire visible pigmentation was removed. Clinical observations for intensity of pigmentation were recorded at baseline and then after surgery at monthly intervals over a period of 9 months according to Dummett-Gupta Oral Pigmentation Index scoring criteria proposed by Dummett C. O. in 1964. Results: The mean gingival melanin pigmentation score came down to 0.407 after 9 months as compared to preoperative score, which was 2.24. No repigmentation occurred in fair-complexioned persons. In persons with wheatish complexion, repigmentation was seen in 85.71% of the cases, but scores came down to 0.38 postoperatively as compared to 2.27 preoperatively. In dark complexioned persons, repigmentation occurred in all cases, but the mean scores were 0.93 as compared to 2.40 preoperatively. The difference between preoperative and postoperative mean scores for each segment was put to statistical analysis by applying paired t test and was found to be significant. Conclusion: As this method has shown statistically significant results, it can be used in patients who are conscious of pigmented gingiva and want an esthetically satisfactory color.

  19. Duration of reappearance of gingival melanin pigmentation after surgical removal — A clinical study

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    Kaur, Harjit; Jain, Sanjeev; Sharma, Roshan Lal

    2010-01-01

    Background: In dentistry, esthetics has a special place. Although gingival melanin pigmentation does not present a medical problem, clinicians are often faced with a challenge of achieving gingival esthetics. Materials and Methods: A method of de-epithelialization of the pigmented gingiva using Kirkland’s gingivectomy knife is described. Twenty patients who were conscious about their gingival melanin pigmentation were selected. The gingiva of the whole of the arch was abraded until the entire visible pigmentation was removed. Clinical observations for intensity of pigmentation were recorded at baseline and then after surgery at monthly intervals over a period of 9 months according to Dummett-Gupta Oral Pigmentation Index scoring criteria proposed by Dummett C. O. in 1964. Results: The mean gingival melanin pigmentation score came down to 0.407 after 9 months as compared to preoperative score, which was 2.24. No repigmentation occurred in fair-complexioned persons. In persons with wheatish complexion, repigmentation was seen in 85.71% of the cases, but scores came down to 0.38 postoperatively as compared to 2.27 preoperatively. In dark-complexioned persons, repigmentation occurred in all cases, but the mean scores were 0.93 as compared to 2.40 preoperatively. The difference between preoperative and postoperative mean scores for each segment was put to statistical analysis by applying paired t test and was found to be significant. Conclusion: As this method has shown statistically significant results, it can be used in patients who are conscious of pigmented gingiva and want an esthetically satisfactory color. PMID:21691546

  20. Pigment Melanin Scavenges Nitric Oxide In Vitro: Possible Relevance to Keloid Formation

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    Julian M. Menter

    2008-01-01

    Full Text Available Recently, nitric oxide (NO has been implicated in the formation of keloids, preferentially formed in dark-skinned persons, and we suspected that pigment melanin itself may play a direct role by adsorbing NO. We tested the ability of cuttlefish sepia melanin to scavenge (adsorb NO, generated in situ by 2-(N.N Diethylamino diazeneolate-2-oxide (DEA/NO, through a dialysis membrane. NO was measured as NO2_ and NO3_ by the Griess method and as N2O3 by trapping experiments with the fluorogenic substrate 4,5-diaminofluorescein (DAF-2. Initial NO2_ and NO3_ concentrations were significantly lower in the test dialyzates than in controls. Scavenging of NO was rapid enough to compete with DAF adduct formation. Both analytical methods gave comparable results. Adsorbed NO and/or its oxidized products may undergo interactions with melanin, adsorbed O2, and/or dermal material that may lead to keloid formation.

  1. Melanins and melanogenesis: from pigment cells to human health and technological applications.

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    d'Ischia, Marco; Wakamatsu, Kazumasa; Cicoira, Fabio; Di Mauro, Eduardo; Garcia-Borron, Josè Carlos; Commo, Stephane; Galván, Ismael; Ghanem, Ghanem; Kenzo, Koike; Meredith, Paul; Pezzella, Alessandro; Santato, Clara; Sarna, Tadeusz; Simon, John D; Zecca, Luigi; Zucca, Fabio A; Napolitano, Alessandra; Ito, Shosuke

    2015-09-01

    During the past decade, melanins and melanogenesis have attracted growing interest for a broad range of biomedical and technological applications. The burst of polydopamine-based multifunctional coatings in materials science is just one example, and the list may be expanded to include melanin thin films for organic electronics and bioelectronics, drug delivery systems, functional nanoparticles and biointerfaces, sunscreens, environmental remediation devices. Despite considerable advances, applied research on melanins and melanogenesis is still far from being mature. A closer intersectoral interaction between research centers is essential to raise the interests and increase the awareness of the biomedical, biomaterials science and hi-tech sectors of the manifold opportunities offered by pigment cells and related metabolic pathways. Starting from a survey of biological roles and functions, the present review aims at providing an interdisciplinary perspective of melanin pigments and related pathway with a view to showing how it is possible to translate current knowledge about physical and chemical properties and control mechanisms into new bioinspired solutions for biomedical, dermocosmetic, and technological applications.

  2. Pigments, patterns, and fish behavior.

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    Price, Anna C; Weadick, Cameron J; Shim, Janet; Rodd, F Helen

    2008-12-01

    Color patterns in fish are often multicomponent signals, composed of pigment-based and structural color patches that can be used to communicate within species, in both inter- and intrasexual interactions, and between species. In this review, we discuss some of the roles played by pigment-based elements of color pattern. We begin by discussing general forms of coloration, classifying them by appearance (e.g., cryptic vs. conspicuous) and apparent function (e.g., conspicuous coloration and mating displays, stripes and cooperation, and bars and aggression). We then briefly discuss the roles pigments play in the perception of these color patterns via their presence in the eye. In the last section, we look at the relative importance of carotenoid versus melanic coloration in situations where honest signals to potential rivals and potential mates might be required. In this survey, we have highlighted some recent research, especially studies that consider both the physiological and behavioral processes underlying the evolution and expression of pigment-based color patterns in fish. The nature of pigmented color patterns depends not just on the dynamics of pattern development and physiological regulation, but also on the behavioral roles played by these patterns, both now and in the past. As such, advances in particular fields of study on pigment patterns (physiology, developmental biology, behavioral ecology, evolutionary biology, etc.) will increasingly depend on insights from other fields.

  3. Molecular imaging of melanin distribution in vivo and quantitative differential diagnosis of human pigmented lesions using label-free harmonic generation biopsy (Conference Presentation)

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    Sun, Chi-Kuang; Wei, Ming-Liang; Su, Yu-Hsiang; Weng, Wei-Hung; Liao, Yi-Hua

    2017-02-01

    Harmonic generation microscopy is a noninvasive repetitive imaging technique that provides real-time 3D microscopic images of human skin with a sub-femtoliter resolution and high penetration down to the reticular dermis. In this talk, we show that with a strong resonance effect, the third-harmonic-generation (THG) modality provides enhanced contrast on melanin and allows not only differential diagnosis of various pigmented skin lesions but also quantitative imaging for longterm tracking. This unique capability makes THG microscopy the only label-free technique capable of identifying the active melanocytes in human skin and to image their different dendriticity patterns. In this talk, we will review our recent efforts to in vivo image melanin distribution and quantitatively diagnose pigmented skin lesions using label-free harmonic generation biopsy. This talk will first cover the spectroscopic study on the melanin enhanced THG effect in human cells and the calibration strategy inside human skin for quantitative imaging. We will then review our recent clinical trials including: differential diagnosis capability study on pigmented skin tumors; as well as quantitative virtual biopsy study on pre- and post- treatment evaluation on melasma and solar lentigo. Our study indicates the unmatched capability of harmonic generation microscopy to perform virtual biopsy for noninvasive histopathological diagnosis of various pigmented skin tumors, as well as its unsurpassed capability to noninvasively reveal the pathological origin of different hyperpigmentary diseases on human face as well as to monitor the efficacy of laser depigmentation treatments. This work is sponsored by National Health Research Institutes.

  4. Bioproduction, characterization, anticancer and antioxidant activities of extracellular melanin pigment produced by newly isolated microbial cell factories Streptomyces glaucescens NEAE-H

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    El-Naggar, Noura El-Ahmady; El-Ewasy, Sara M.

    2017-01-01

    In this present study, a newly isolated strain, Streptomyces sp. NEAE-H, capable of producing high amount of black extracellular melanin pigment on peptone-yeast extract iron agar and identified as Streptomyces glaucescens NEAE-H. Plackett–Burman statistical design was conducted for initial screening of 17 independent (assigned) variables for their significances on melanin pigment production by Streptomyces glaucescens NEAE-H. The most significant factors affecting melanin production are incubation period, protease-peptone and ferric ammonium citrate. The levels of these significant variables and their interaction effects were optimized by using face-centered central composite design. The maximum melanin production (31.650 μg/0.1 ml) and tyrosinase activity (6089.10 U/ml) were achieved in the central point runs under the conditions of incubation period (6 days), protease-peptone (5 g/L) and ferric ammonium citrate (0.5 g/L). Melanin pigment was recovered by acid-treatment. Higher absorption of the purified melanin pigment was observed in the UV region at 250 nm. It appeared to have defined small spheres by scanning electron microscopy imaging. The maximum melanin yield was 350 mg dry wt/L of production medium. In vitro anticancer activity of melanin pigment was assayed against skin cancer cell line using MTT assay. The IC50 value was 16.34 ± 1.31 μg/ml for melanin and 8.8 ± 0.5 μg/ml for standard 5-fluorouracil. PMID:28195138

  5. [Influence of low dozes of ionizing radiation on accumulation of melanin pigments and catalase and superoxidedismutase activities in Cladosporium cladosporioides].

    Science.gov (United States)

    Tuhaĭ, T I

    2007-01-01

    Influence of low dozes of ionizing radiation on melanin pigments synthesis and activity of antioxidant enzymes catalase and superoxidedismutase of two strains of Cladosporium cladosporioides 4, (isolated from radioactive soil) and 396 (control) were investigated. It was shown, that in C. cladosporioides 4 under the exposure of ionizing radiation an increase of melanin synthesis in a stationary growth phase and increase of superoxidedismutase activity in a logarithmic phase were observed; in the control strain C. cladosporioides 396 activation of melanin synthesis and superoxide dismutase activity in both growth phases was revealed. It was established that in C. cladosporioides 4 the endocellular catalase activity in a logarithmic phase is 3.2 times higher, than in control strain. Under the action of ionizing radiation a 2-fold increase of this enzyme activity unlike the control strain in which the activity inhibition was revealed. The obtained results testify to the complex response of antioxidant systems and melanin to the action of low dozes of radiation which depends on the growth phase and presence of radioadaptation properties in the investigated fungi.

  6. Retroperitoneal sclerosing PEComa with melanin pigmentation and granulomatous inflammation-A rare association within an uncommon tumor

    Directory of Open Access Journals (Sweden)

    Bharat Rekhi

    2012-01-01

    Full Text Available PEComa, defined as a perivascular epithelioid cell tumor, displays a wide clinicopathological spectrum. Lately, a sclerosing PEComa has been identified as its distinct variant, but with limited documentation, in view of its rarity. Herein, we describe an uncommon case of a 53-year-old lady, who was referred to us with pain abdomen. Radiological imaging disclosed a well-defined, hypodense retroperitoneal mass. The excised tumor was a round, encapsulated soft tissue mass measuring 7 cm with a tan-brown cut surface. Microscopy showed uniform, epithelioid cells with clear cytoplasm, focal melanin pigmentation and mild nuclear atypia, arranged in sheets and nests around capillary-sized vessels in a dense sclerotic stroma. Additionally, co-existing epithelioid granulomas were noted. On immunohistochemistry (IHC, tumor cells were diffusely positive for HMB45; focally for desmin and smooth muscle actin (SMA, while negative for EMA, CD10, S100-P, Melan A, CD34, AMACR and CK MNF116. This case reinforces sclerosing PEComa as an uncommon, but a distinct clinicopathological entity and exemplifies diagnostic challenge associated with it; necessitating application of IHC markers for its correct identification. Presence of melanin pigment and granulomatous inflammation in the present tumor constitute as novel histopathological findings in a sclerosing PEComa.

  7. Unusual extensive physiologic melanin pigmentation of the oral cavity: A clinical presentation

    Directory of Open Access Journals (Sweden)

    K Mallikarjuna

    2013-01-01

    Full Text Available Pigmented lesions are commonly found in the oral cavity. Oral pigmentations may be physiological or pathological in nature. It may represent as a localized anomaly of limited significance or the presentation of potentially life threatening multisystem disease. Oral pigmentation has a multifactorial etiology. Most of the oral pigmentations are physiologic. Evaluation of a patient with pigmented lesions should include a full medical and dental history, extraoral and intraoral examinations. In this article, we report a case of extensive physiologic pigmentation of the oral cavity in a 12 year old female patient, posing a diagnostic challenge.

  8. Aspergillus fumigatus conidial melanin modulates host cytokine response

    NARCIS (Netherlands)

    L.Y.A. Chai (Louis); M.G. Netea (Mihai); J. Sugui (Janyce); A.G. Vonk (Alieke); W.W.J. van de Sande (Wendy); A. Warris (Adilia); K.J. Kwon-Chung (Kyung); B. Jan Kullberg (Bart)

    2010-01-01

    textabstractMelanin biopigments have been linked to fungal virulence. Aspergillus fumigatus conidia are melanised and are weakly immunogenic. We show that melanin pigments on the surface of resting Aspergillus fumigatus conidia may serve to mask pathogen-associated molecular patterns (PAMPs)-induced

  9. Aspergillus fumigatus conidial melanin modulates host cytokine response.

    NARCIS (Netherlands)

    Chai, L.; Netea, M.G.; Sugui, J.; Vonk, A.G.; Sande, W.W. van de; Warris, A.; Kwon-Chung, K.J.; Kullberg, B.J.

    2010-01-01

    Melanin biopigments have been linked to fungal virulence. Aspergillus fumigatus conidia are melanised and are weakly immunogenic. We show that melanin pigments on the surface of resting Aspergillus fumigatus conidia may serve to mask pathogen-associated molecular patterns (PAMPs)-induced cytokine re

  10. Aspergillus fumigatus conidial melanin modulates host cytokine response.

    NARCIS (Netherlands)

    Chai, L.; Netea, M.G.; Sugui, J.; Vonk, A.G.; Sande, W.W. van de; Warris, A.; Kwon-Chung, K.J.; Kullberg, B.J.

    2010-01-01

    Melanin biopigments have been linked to fungal virulence. Aspergillus fumigatus conidia are melanised and are weakly immunogenic. We show that melanin pigments on the surface of resting Aspergillus fumigatus conidia may serve to mask pathogen-associated molecular patterns (PAMPs)-induced cytokine

  11. Aspergillus fumigatus conidial melanin modulates host cytokine response

    NARCIS (Netherlands)

    L.Y.A. Chai (Louis); M.G. Netea (Mihai); J. Sugui (Janyce); A.G. Vonk (Alieke); W.W.J. van de Sande (Wendy); A. Warris (Adilia); K.J. Kwon-Chung (Kyung); B. Jan Kullberg (Bart)

    2010-01-01

    textabstractMelanin biopigments have been linked to fungal virulence. Aspergillus fumigatus conidia are melanised and are weakly immunogenic. We show that melanin pigments on the surface of resting Aspergillus fumigatus conidia may serve to mask pathogen-associated molecular patterns (PAMPs)-induced

  12. Biocatalysis on the surface of Escherichia coli: melanin pigmentation of the cell exterior

    Science.gov (United States)

    Gustavsson, Martin; Hörnström, David; Lundh, Susanna; Belotserkovsky, Jaroslav; Larsson, Gen

    2016-01-01

    Today, it is considered state-of-the-art to engineer living organisms for various biotechnology applications. Even though this has led to numerous scientific breakthroughs, the enclosed interior of bacterial cells still restricts interactions with enzymes, pathways and products due to the mass-transfer barrier formed by the cell envelope. To promote accessibility, we propose engineering of biocatalytic reactions and subsequent product deposition directly on the bacterial surface. As a proof-of-concept, we used the AIDA autotransporter vehicle for Escherichia coli surface expression of tyrosinase and fully oxidized externally added tyrosine to the biopolymer melanin. This resulted in a color change and creation of a black cell exterior. The capture of ninety percent of a pharmaceutical wastewater pollutant followed by regeneration of the cell bound melanin matrix through a simple pH change, shows the superior function and facilitated processing provided by the surface methodology. The broad adsorption spectrum of melanin could also allow removal of other micropollutants. PMID:27782179

  13. Skin Pigmentation Disorders

    Science.gov (United States)

    Pigmentation means coloring. Skin pigmentation disorders affect the color of your skin. Your skin gets its color from a pigment called melanin. Special cells in the skin make melanin. When these cells become damaged or ...

  14. A comparison of diode laser and Er:YAG lasers in the treatment of gingival melanin pigmentation.

    Science.gov (United States)

    Simşek Kaya, Göksel; Yapici Yavuz, Günay; Sümbüllü, Muhammed A; Dayi, Ertunç

    2012-03-01

    This study compared the use of diode and Er:YAG lasers in treating gingival melanin pigmentation (GMP) in terms of gingival depigmentation, local anesthesia requirements, postoperative pain/discomfort, depigmentation effectiveness, and total treatment duration. Twenty patients (13 female, 7 male) referred with GMP were enrolled in the study. Patients were randomly divided into 2 groups. Group 1 was treated with a gallium aluminum arsenide diode laser with a continuous wavelength of 808 nm, and group 2 was treated with an Er:YAG laser with a continuous wavelength of 2,940 nm. Gingival depigmentation was performed by applying the laser at 1 W. Treatment was administered on a weekly basis until a normal pink gingival color was observable in clinical examination and photographs. In addition, patients were asked to evaluate the procedure by using a self-administered questionnaire. Procedures were carried out without the need for any topical or local anesthetic, and no unpleasant events occurred during the actual procedure or the healing period. The total length of treatment was significantly shorter with the diode laser (group 1) than with the Er:YAG laser (group 2; P lasers administered at 1 W both result in satisfactory depigmentation of GMP. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Research progress in the treatment of gingival melanin pigmentation%牙龈黑色素沉着治疗研究进展

    Institute of Scientific and Technical Information of China (English)

    夏静

    2014-01-01

    牙龈黑色素沉着(gingival melanin pigmentation,GMP)是由于黑色素母细胞分泌的黑色素颗粒沉积在牙龈黏膜的基底层及固有层所导致.虽然在多数情况下它不是病理性症状,但却给许多患者,尤其是露龈笑的患者造成美观上的困扰.本文对GMP的治疗方法及研究进展做一综述.

  16. Clinical study on the removal of gingival melanin pigmentation: comparison between Nd:YAG laser ablation and mechanical abrasion; Estudo clinico comparativo entre as tecnicas de despigmentacao melanica gengival: laser neodimio (1064 nm) e gengivoabrasao

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Luis Mario de Melo

    2002-07-01

    Melanin pigmentation occurs as a result of excessive deposition of melanin, produced by the melanocytes present in the basal layer of the epithelium. This study compares clinical parameters such as inflammation and/or hemorrhage, healing process and re-pigmentation, caused by the Nd:YAG laser ablation and the mechanical abrasion of the melanin, by means of photographic images, taken during the first 30 days after the treatment. The patients comfort was monitored during the first ten days after the treatment using the method of the Visual Analog Scale to measure the pain. Six patients with gingival melanin pigmentation were selected. The left upper gingival quadrant was treated with the Nd:YAG laser using 125 mJ per pulse and 20 Hz, the right upper gingival quadrant received mechanical abrasion and the lower quadrants served for control. Both techniques did not result in inflammation and/or hemorrhage. The healing process was slower with the laser. Using mechanical abrasion, ali patients showed remaining pigmentation or re-pigmentation of varying intensity after a period of 30 days. With the laser 50 % of the patients did not show any re-pigmentation after this period. The pain analysis showed that the pain sensed 24 hours after the treatment with the laser is higher than using mechanical abrasion. (author)

  17. Pigmentation in Anuran Testes: Anatomical Pattern and Variation

    OpenAIRE

    Franco-Belussi, Lilian [UNESP; Zieri, Rodrigo [UNESP; de Souza Santos, Lia Raquel; Moresco, Rafaela Maria; Oliveira, Classius de [UNESP

    2009-01-01

    In amphibians, pigmented cells are present in several organs, composing an extracutaneous pigmentary system. Seventeen species from two families were studied to develop a protocol for pigmentary classification. The amount and distribution of these cells are variable, allowing the establishment of anatomical patterns for visceral pigmentation in anuran testes. Anat Rec, 292:178-182, 2009. (C) 2008 Wiley-Liss, Inc.

  18. A Preliminary Study on the Pattern, the Physiological Bases and the Molecular Mechanism of the Adductor Muscle Scar Pigmentation in Pacific Oyster Crassostrea gigas

    Directory of Open Access Journals (Sweden)

    Wenchao Yu

    2017-09-01

    Full Text Available The melanin pigmentation of the adductor muscle scar and the outer surface of the shell are among attractive features and their pigmentation patterns and mechanism still remains unknown in the Pacific oyster Crassostrea gigas. To study these pigmentation patterns, the colors of the adductor muscle scar vs. the outer surface of the shell on the same side were compared. No relevance was found between the colors of the adductor muscle scars and the corresponding outer surface of the shells, suggesting that their pigmentation processes were independent. Interestingly, a relationship between the color of the adductor muscle scars and the dried soft-body weight of Pacific oysters was found, which could be explained by the high hydroxyl free radical scavenging capacity of the muscle attached to the black adductor muscle scar. After the transcriptomes of pigmented and unpigmented adductor muscles and mantles were studied by RNAseq and compared, it was found that the retinol metabolism pathway were likely to be involved in melanin deposition on the adductor muscle scar and the outer surface of the shell, and that the different members of the tyrosinase or Cytochrome P450 gene families could play a role in the independent pigmentation of different organs.

  19. Black perithecial pigmentation in Fusarium species is due to the accumulation of 5-deoxybostrycoidin-based melanin

    DEFF Research Database (Denmark)

    Frandsen, Rasmus John Normand; Rasmussen, Silas Anselm; Knudsen, Peter Boldsen

    2016-01-01

    anthrone (4) and purpurfusarin (5). The novel dimeric bostrycoidin purpurfusarin (5) was found to inhibit the growth of Candida albicans with an IC50 of 8.0 +/-1.9 mu M. The results show that Fusarium species with black perithecia have a previously undescribed form of 5-deoxybostrycoidin based melanin...

  20. Origins of adult pigmentation: diversity in pigment stem cell lineages and implications for pattern evolution.

    Science.gov (United States)

    Parichy, David M; Spiewak, Jessica E

    2015-01-01

    Teleosts comprise about half of all vertebrate species and exhibit an extraordinary diversity of adult pigment patterns that function in shoaling, camouflage, and mate choice and have played important roles in speciation. Here, we review studies that have identified several distinct neural crest lineages, with distinct genetic requirements, that give rise to adult pigment cells in fishes. These lineages include post-embryonic, peripheral nerve-associated stem cells that generate black melanophores and iridescent iridophores, cells derived directly from embryonic neural crest cells that generate yellow-orange xanthophores, and bipotent stem cells that generate both melanophores and xanthophores. This complexity in adult chromatophore lineages has implications for our understanding of adult traits, melanoma, and the evolutionary diversification of pigment cell lineages and patterns.

  1. Trace metals, melanin-based pigmentation and their interaction influence immune parameters in feral pigeons (Columba livia).

    Science.gov (United States)

    Chatelain, M; Gasparini, J; Frantz, A

    2016-04-01

    Understanding the effects of trace metals emitted by anthropogenic activities on wildlife is of great concern in urban ecology; yet, information on how they affect individuals, populations, communities and ecosystems remains scarce. In particular, trace metals may impact survival by altering the immune system response to parasites. Plumage melanin is assumed to influence the effects of trace metals on immunity owing to its ability to bind metal ions in feathers and its synthesis being coded by a pleiotropic gene. We thus hypothesized that trace metal exposure would interact with plumage colouration in shaping immune response. We experimentally investigated the interactive effect between exposure to an environmentally relevant range of zinc and/or lead and melanin-based plumage colouration on components of the immune system in feral pigeons (Columba livia). We found that zinc increased anti-keyhole limpet hemocyanin (KLH) IgY primary response maintenance, buffered the negative effect of lead on anti-KLH IgY secondary response maintenance and tended to increase T-cell mediated phytohaemagglutinin (PHA) skin response. Lead decreased the peak of the anti-KLH IgY secondary response. In addition, pheomelanic pigeons exhibited a higher secondary anti-KLH IgY response than did eumelanic ones. Finally, T-cell mediated PHA skin response decreased with increasing plumage eumelanin level of birds exposed to lead. Neither treatments nor plumage colouration correlated with endoparasite intensity. Overall, our study points out the effects of trace metals on some parameters of birds' immunity, independently from other confounding urbanization factors, and underlines the need to investigate their impacts on other life history traits and their consequences in the ecology and evolution of host-parasite interactions.

  2. Chemical, experimental, and morphological evidence for diagenetically altered melanin in exceptionally preserved fossils.

    Science.gov (United States)

    Colleary, Caitlin; Dolocan, Andrei; Gardner, James; Singh, Suresh; Wuttke, Michael; Rabenstein, Renate; Habersetzer, Jörg; Schaal, Stephan; Feseha, Mulugeta; Clemens, Matthew; Jacobs, Bonnie F; Currano, Ellen D; Jacobs, Louis L; Sylvestersen, Rene Lyng; Gabbott, Sarah E; Vinther, Jakob

    2015-10-13

    In living organisms, color patterns, behavior, and ecology are closely linked. Thus, detection of fossil pigments may permit inferences about important aspects of ancient animal ecology and evolution. Melanin-bearing melanosomes were suggested to preserve as organic residues in exceptionally preserved fossils, retaining distinct morphology that is associated with aspects of original color patterns. Nevertheless, these oblong and spherical structures have also been identified as fossilized bacteria. To date, chemical studies have not directly considered the effects of diagenesis on melanin preservation, and how this may influence its identification. Here we use time-of-flight secondary ion mass spectrometry to identify and chemically characterize melanin in a diverse sample of previously unstudied extant and fossil taxa, including fossils with notably different diagenetic histories and geologic ages. We document signatures consistent with melanin preservation in fossils ranging from feathers, to mammals, to amphibians. Using principal component analyses, we characterize putative mixtures of eumelanin and phaeomelanin in both fossil and extant samples. Surprisingly, both extant and fossil amphibians generally exhibit melanosomes with a mixed eumelanin/phaeomelanin composition rather than pure eumelanin, as assumed previously. We argue that experimental maturation of modern melanin samples replicates diagenetic chemical alteration of melanin observed in fossils. This refutes the hypothesis that such fossil microbodies could be bacteria, and demonstrates that melanin is widely responsible for the organic soft tissue outlines in vertebrates found at exceptional fossil localities, thus allowing for the reconstruction of certain aspects of original pigment patterns.

  3. Chemical, experimental, and morphological evidence for diagenetically altered melanin in exceptionally preserved fossils

    Science.gov (United States)

    Colleary, Caitlin; Dolocan, Andrei; Gardner, James; Singh, Suresh; Wuttke, Michael; Rabenstein, Renate; Habersetzer, Jörg; Schaal, Stephan; Feseha, Mulugeta; Clemens, Matthew; Jacobs, Bonnie F.; Currano, Ellen D.; Jacobs, Louis L.; Lyng Sylvestersen, Rene; Gabbott, Sarah E.; Vinther, Jakob

    2015-10-01

    In living organisms, color patterns, behavior, and ecology are closely linked. Thus, detection of fossil pigments may permit inferences about important aspects of ancient animal ecology and evolution. Melanin-bearing melanosomes were suggested to preserve as organic residues in exceptionally preserved fossils, retaining distinct morphology that is associated with aspects of original color patterns. Nevertheless, these oblong and spherical structures have also been identified as fossilized bacteria. To date, chemical studies have not directly considered the effects of diagenesis on melanin preservation, and how this may influence its identification. Here we use time-of-flight secondary ion mass spectrometry to identify and chemically characterize melanin in a diverse sample of previously unstudied extant and fossil taxa, including fossils with notably different diagenetic histories and geologic ages. We document signatures consistent with melanin preservation in fossils ranging from feathers, to mammals, to amphibians. Using principal component analyses, we characterize putative mixtures of eumelanin and phaeomelanin in both fossil and extant samples. Surprisingly, both extant and fossil amphibians generally exhibit melanosomes with a mixed eumelanin/phaeomelanin composition rather than pure eumelanin, as assumed previously. We argue that experimental maturation of modern melanin samples replicates diagenetic chemical alteration of melanin observed in fossils. This refutes the hypothesis that such fossil microbodies could be bacteria, and demonstrates that melanin is widely responsible for the organic soft tissue outlines in vertebrates found at exceptional fossil localities, thus allowing for the reconstruction of certain aspects of original pigment patterns.

  4. Fungal melanins differ in planar stacking distances.

    Science.gov (United States)

    Casadevall, Arturo; Nakouzi, Antonio; Crippa, Pier R; Eisner, Melvin

    2012-01-01

    Melanins are notoriously difficult to study because they are amorphous, insoluble and often associated with other biological materials. Consequently, there is a dearth of structural techniques to study this enigmatic pigment. Current models of melanin structure envision the stacking of planar structures. X ray diffraction has historically been used to deduce stacking parameters. In this study we used X ray diffraction to analyze melanins derived from Cryptococcus neoformans, Aspergillus niger, Wangiella dermatitides and Coprinus comatus. Analysis of melanin in melanized C. neoformans encapsulated cells was precluded by the fortuitous finding that the capsular polysaccharide had a diffraction spectrum that was similar to that of isolated melanin. The capsular polysaccharide spectrum was dominated by a broad non-Bragg feature consistent with origin from a repeating structural motif that may arise from inter-molecular interactions and/or possibly gel organization. Hence, we isolated melanin from each fungal species and compared diffraction parameters. The results show that the inferred stacking distances of fungal melanins differ from that reported for synthetic melanin and neuromelanin, occupying intermediate position between these other melanins. These results suggest that all melanins have a fundamental diffracting unit composed of planar graphitic assemblies that can differ in stacking distance. The stacking peak appears to be a distinguishing universal feature of melanins that may be of use in characterizing these enigmatic pigments.

  5. Evidence for a Melanin Cell Wall Component in Pneumocystis carinii

    OpenAIRE

    Icenhour, Crystal R.; Kottom, Theodore J.; Limper, Andrew H

    2003-01-01

    Fluorescein isothiocyanate-labeled monoclonal antibodies specific for fungal melanin were used in this study to visualize melanin-like components of the Pneumocystis carinii cell wall. A colorimetric enzyme assay confirmed these findings. This is the first report of melanin-like pigments in Pneumocystis.

  6. Pigment cell interactions and differential xanthophore recruitment underlying zebrafish stripe reiteration and Danio pattern evolution.

    Science.gov (United States)

    Patterson, Larissa B; Bain, Emily J; Parichy, David M

    2014-11-06

    Fishes have diverse pigment patterns, yet mechanisms of pattern evolution remain poorly understood. In zebrafish, Danio rerio, pigment-cell autonomous interactions generate dark stripes of melanophores that alternate with light interstripes of xanthophores and iridophores. Here, we identify mechanisms underlying the evolution of a uniform pattern in D. albolineatus in which all three pigment cell classes are intermingled. We show that in this species xanthophores differentiate precociously over a wider area, and that cis regulatory evolution has increased expression of xanthogenic Colony Stimulating Factor-1 (Csf1). Expressing Csf1 similarly in D. rerio has cascading effects, driving the intermingling of all three pigment cell classes and resulting in the loss of stripes, as in D. albolineatus. Our results identify novel mechanisms of pattern development and illustrate how pattern diversity can be generated when a core network of pigment-cell autonomous interactions is coupled with changes in pigment cell differentiation.

  7. DOPA and DHN pathway orchestrate melanin synthesis in Aspergillus species.

    Science.gov (United States)

    Pal, Anuradha K; Gajjar, Devarshi U; Vasavada, Abhay R

    2014-01-01

    Melanins are high molecular weight hydrophobic pigments that have been studied for their role in the virulence of fungal pathogens. We investigated the amount and type of melanin in 20 isolates of Aspergillus spp.; A. niger (n = 3), A. flavus (n = 5), A. tamarii (n = 3), A. terreus (n = 3), A. tubingensis (n = 3), A. sydowii (n = 3). Aspergillus spp. were identified by sequencing the internal transcribed spacer (ITS) region. Extraction of melanin from culture filtrate and fungal biomass was done and followed by qualitative and quantitative analysis of melanin pigment. Ultraviolet (UV), Fourier transformed infrared (FT-IR), and electron paramagnetic resonance (EPR) spectra analyses confirmed the presence of melanin. The melanin pathway was studied by analyzing the effects of inhibitors; kojic acid, tropolone, phthalide, and tricyclazole. The results indicate that in A. niger and A. tubingensis melanin was found in both culture filtrate and fungal biomass. For A. tamarii and A. flavus melanin was extracted from biomass only, whereas melanin was found only in culture filtrate for A. terreus. A negligible amount of melanin was found in A. sydowii. The maximum amount of melanin from culture filtrate and fungal biomass was found in A. niger and A. tamarrii, respectively. The DOPA (3,4-dihydroxyphenylalanine) pathway produces melanin in A. niger, A. tamarii and A. flavus, whereas the DHN (1,8-dihydroxynaphthalene) pathway produces melanin in A. tubingensis and A. terreus. It can be concluded that the amount and type of melanin in aspergilli largely differ from species to species.

  8. Unlocking the molecular structure of fungal melanin using 13C biosynthetic labeling and solid-state NMR.

    Science.gov (United States)

    Tian, Shiying; Garcia-Rivera, Javier; Yan, Bin; Casadevall, Arturo; Stark, Ruth E

    2003-07-15

    Melanins are enigmatic pigments found in all biological kingdoms that are associated with a variety of functions, including microbial virulence. Despite being ubiquitous in nature, melanin pigments have long resisted atomic-level structural examination because of their insolubility and amorphous organization. Cryptococcus neoformans is a human pathogenic fungus that melanizes only when provided with exogenous substrate, thus offering a unique system for exploring questions related to melanin structure at the molecular level. We have exploited the requirement for exogenous substrate in melanin synthesis as well as the capabilities of high-resolution solid-state nuclear magnetic resonance (NMR) to establish the predominantly aliphatic composition of l-dopa melanin and to introduce (13)C labels that permit the identification of proximal carbons in the developing biopolymer. By swelling solid melanin samples in organic solvents and using two-dimensional heteronuclear NMR in conjunction with magic-angle spinning, we have identified chemical bonding patterns typical of alkane, alkene, alcohol, ketone, ester, and indole functional groups. These findings demonstrate the feasibility of a novel approach to determining the structure of melanin using metabolic labeling and NMR spectroscopy.

  9. Inhibitory effects of salidroside and paeonol on tyrosinase activity and melanin synthesis in mouse B16F10 melanoma cells and ultraviolet B-induced pigmentation in guinea pig skin.

    Science.gov (United States)

    Peng, Li-Hua; Liu, Shuai; Xu, Shen-Yao; Chen, Lei; Shan, Ying-Hui; Wei, Wei; Liang, Wen-Quan; Gao, Jian-Qing

    2013-09-15

    Salidroside, the major active component of Rhodiola rosea, a herb with antioxidant, free radical scavenging and tyrosinase inhibitory effects, has been recently reported in protecting the kerationcytes from the UV radiation, suggesting the potential of this component in depigmentation. Paeonol is isolated from Moutan Cortex Radicis with anti-inflammation/microbial activities, was reported to induce the down-regulation of microphthalmia-associated transcription factor and subsequently tyrosinase. To testify the potential of these compounds as melanin formation inhibitors for hyperpigmentation therapy, the influence of salidroside and paeonol on pigmentation was investigated. With arbutin as a positive control, salidroside and paeonol were evaluated for their inhibitory effect on the cell viability, tyrosinase activity and melanin synthesis in B16F10 melanoma cells, as well as their effects in UVB-induced hyperpigmentation in brown guinea pig skins. It was demonstrated that the significant inhibition of salidroside (33.0%) and paeonol (22.2-30.9%) on the tyrosinase activity is slightly lower than that of arbutin (18.4-44.7%). However, salidroside exhibited the dose-dependent inhibition (30.6-42.0%) in melanin synthesis at a low concentration of 100 μM, paeonol and arbutin expressed inhibition rates of 27.4-37.2% and 25.8-45.6% within 500-1000 μM. The in vivo topical application of these compounds was demonstrated to obviously decrease the hyperpigmentation on UVB stimulated guinea pig skin. This study provided the original evidence for the salidroside and paeonol as therapeutic agents for pigmentation disorder and skin lightening, with further clinical investigation of these compounds in the field of depigmentation was suggested. Copyright © 2013 Elsevier GmbH. All rights reserved.

  10. Actinobacterial melanins: current status and perspective for the future.

    Science.gov (United States)

    Manivasagan, Panchanathan; Venkatesan, Jayachandran; Sivakumar, Kannan; Kim, Se-Kwon

    2013-10-01

    Melanins are enigmatic pigments that are produced by a wide variety of microorganisms including several species of bacteria and fungi. Melanins are biological macromolecules with multiple important functions, yet their structures are not well understood. Melanins are frequently used in medicine, pharmacology, and cosmetics preparations. Melanins also have great application potential in agriculture industry. They have several biological functions including photoprotection, thermoregulation, action as free radical sinks, cation chelators, and antibiotics. Plants and insects incorporate melanins as cell wall and cuticle strengtheners, respectively. Actinobacteria are the most economically as well as biotechnologically valuable prokaryotes. However, the melanin properties are, in general, poorly understood. In this review an evaluation is made on the present state of research on actinobacterial melanins and its perspectives. The highlights include the production and biotechnological applications of melanins in agriculture, food, cosmetic and medicinal fields. With increasing advancement in science and technology, there would be greater demands in the future for melanins produced by actinobacteria from various sources.

  11. Synthesis and assembly of fungal melanin.

    Science.gov (United States)

    Eisenman, Helene C; Casadevall, Arturo

    2012-02-01

    Melanin is a unique pigment with myriad functions that is found in all biological kingdoms. It is multifunctional, providing defense against environmental stresses such as ultraviolet (UV) light, oxidizing agents and ionizing radiation. Melanin contributes to the ability of fungi to survive in harsh environments. In addition, it plays a role in fungal pathogenesis. Melanin is an amorphous polymer that is produced by one of two synthetic pathways. Fungi may synthesize melanin from endogenous substrate via a 1,8-dihydroxynaphthalene (DHN) intermediate. Alternatively, some fungi produce melanin from L-3,4-dihydroxyphenylalanine (L-dopa). The detailed chemical structure of melanin is not known. However, microscopic studies show that it has an overall granular structure. In fungi, melanin granules are localized to the cell wall where they are likely cross-linked to polysaccharides. Recent studies suggest the fungal melanin may be synthesized in internal vesicles akin to mammalian melanosomes and transported to the cell wall. Potential applications of melanin take advantage of melanin's radioprotective properties and propensity to bind to a variety of substances.

  12. Development of Betta splendens embryos and larvae reveals variation in pigmentation patterns.

    Science.gov (United States)

    Carey, Alexis N; Lyvers, Benjamin H; Ferrill, Rachel N; Johnson, Rachel L; Dumaine, Anne Marie; Sly, Belinda J

    2016-06-01

    Vertebrate pigmentation provides an ideal system for studying the intersections between evolution, genetics, and developmental biology. Teleost fish, with their accessible developmental stages and intense and diverse colours produced by chromatophores, are an ideal group for study. We set out to test whether Betta splendens is a good model organism for studying the evolution and development of diverse pigmentation. Our results demonstrate that B. splendens can be bred to produce large numbers of offspring with easily visualized pigment cells. Depending on the colour of the parents, there was variation in larval pigmentation patterns both within and between breeding events. In juveniles the developing adult pigmentation patterns showed even greater variation. These results suggest that B. splendens has great potential as a model organism for pigmentation studies.

  13. How animals get their skin patterns: fish pigment pattern as a live Turing wave.

    Science.gov (United States)

    Kondo, Shigeru; Iwashita, Motoko; Yamaguchi, Motoomi

    2009-01-01

    It is more than fifty years since Alan Turing first presented the reaction-diffusion (RD) model, to account for the mechanism of biological pattern formation. In the paper entitled "The chemical basis of morphogenesis", Turing concluded that spatial patterns autonomously made in the embryo are generated as the stationary wave of the chemical (cellular) reactions. Although this novel idea was paid little attention by experimental biologists, recent experimental data are suggesting that the RD mechanism really functions in some of the course of animal development. Among the phenomena in which involvement of the RD mechanism is suspected, the striped pigment pattern of zebrafish has been highlighted as an ideal model system for the following reasons: the stationary wave made by the RD mechanism stays alive and can be observed only in the fish skin; and in zebrafish, we can utilize genomic information and molecular genetic techniques to clarify the molecular basis of pattern formation. In this review, we summarize recent progresses in the study of zebrafish pigment pattern formation that is uncovering how the RD wave is made and maintained in the skin.

  14. A novel role for pigment genes in the stress response in rainbow trout (Oncorhynchus mykiss)

    DEFF Research Database (Denmark)

    Khan, Uniza Wahid; Øverli, Øyvind; Hinkle, Patricia M

    2016-01-01

    In many vertebrate species visible melanin-based pigmentation patterns correlate with high stress- and disease-resistance, but proximate mechanisms for this trait association remain enigmatic. Here we show that a missense mutation in a classical pigmentation gene, melanocyte stimulating hormone...... protein (ASIP) mRNA in skin, likely explaining the association between HR-traits and reduced skin melanin patterning. Molecular dynamics simulations predict that melanocortin 2 receptor accessory protein (MRAP), needed for MC2R function, binds differently to the two MC1R variants. Considering that m...

  15. Optimization of Extraction Process for Melanin Pigment from Apricot Kernel Skin%杏仁种皮黑色素提取工艺优化

    Institute of Scientific and Technical Information of China (English)

    李巨秀; 李红姣; 赵忠; 夏秋敏; 朱海兰

    2012-01-01

    Melanin is a kind of complex polymeric phenolic compound,which can be used in the field of medicine,cosmetics,food and electron.In this work,melanin was extracted from apricot kernel skin by alkaline extraction,acid hydrolysis,and repeated precipitation,and one-factor-at-a-time and orthogonal array design methods were used to optimize four extraction conditions including NaOH concentration,extraction temperature,extraction time and material-to-liquid ratio based on melanin yield.Three extraction conditions except extraction time had a highly significant effect on melanin yield(P 0.01),and could be ranked in descending order of importance as follows: extraction temperature NaOH concentration material-to-liquid ratio.The optimal extraction conditions were NaOH concentration of 0.4 mol/L,extraction temperature of 80 ℃,and extraction duration of 6 h,and material-to-liquid ratio of 1:20.Under these conditions,the yield of melanin was 7.2%.%以杏仁种皮为试验材料,采用碱溶解酸沉淀的方法提取黑色素,以氢氧化钠溶液浓度、提取温度、提取时间、料液比为考察因素,以黑色素得率为指标,通过单因素和正交试验,研究山杏种皮黑色素的提取工艺。结果表明:氢氧化钠浓度、提取温度、料液比3个因素对黑色素的得率均表现出极显著(P〈0.01)影响;3个因素对黑色素提取得率影响的主次顺序为提取温度〉氢氧化钠浓度〉料液比;最佳工艺为氢氧化钠浓度0.4mol/L、提取温度80℃、提取时间6h、料液比1:20(g/mL),黑色素得率达到7.2%。

  16. Spiders do have melanin after all.

    Science.gov (United States)

    Hsiung, Bor-Kai; Blackledge, Todd A; Shawkey, Matthew D

    2015-11-01

    Melanin pigments are broadly distributed in nature - from bacteria to fungi to plants and animals. However, many previous attempts to identify melanins in spiders were unsuccessful, suggesting that these otherwise ubiquitous pigments were lost during spider evolution. Yet, spiders exhibit many dark colours similar to those produced by melanins in other organisms, and the low solubility of melanins makes isolation and characterization difficult. Therefore, whether melanins are truly absent or have simply not yet been detected is an open question. Raman spectroscopy provides a reliable way to detect melanins in situ, without the need for isolation. In this study, we document the presence of eumelanin in diverse species of spiders using confocal Raman microspectroscopy. Comparisons of spectra with theoretically calculated data falsify the previous hypothesis that dark colours are produced solely by ommochromes in spiders. Our data indicate that melanins are present in spiders and further supporting that they are present in most living organisms. © 2015. Published by The Company of Biologists Ltd.

  17. Melanin: A scavenger in gingival inflammation

    Directory of Open Access Journals (Sweden)

    S Nilima

    2011-01-01

    Full Text Available Background: One of the major direct or indirect targets of ultraviolet exposure of skin is the melanocyte or the melanin -forming cell. Epidermal melanocytes act as a trap for free radicals. Based on the protective role of melanocytes in medical literature, the role of melanin pigmentation in gingiva needs to be elucidated. Periodontal pathogens and their products demonstrate the ability to induce the generation of reactive oxygen species. Hence purpose of this study was to unravel the protective role of melanin (if any against the gingival inflammation. Materials and Methods: A total of 80 subjects; 20 in each group were selected. The selection of subjects regarding gingival pigmentation was based on Dummett′s scoring criteria 0, 3. A complete medical, dental history and an informed consent were obtained from the patients. After evaluation of clinical parameters the GCF was collected using microcapillary pipettes at the selected sites. IL-1β levels were quantitated using ELISA. Results: In non-pigmented healthy and gingivitis groups, there was a positive correlation between plaque index, gingival index and bleeding index versus IL-1β level: indicating an increase in the biochemical mediator of inflammation corresponding to an increase in the clinical parameters of inflammation. Also a positive correlation was found between the gingival index and bleeding index versus the IL-1β levels in the pigmented healthy group. The pigmented gingivitis groups showed a negative correlation between the plaque index, gingival index and bleeding index. Conclusions: The clinical markers of inflammation such as gingival index, bleeding index was of low numerical value in pigmented group than in the non-pigmented group, supposedly due to the protective action of melanin. The negative correlation of clinical markers of inflammation to the IL-1β levels in the pigmented gingivitis group could possibly be attributed to the protective role of melanins.

  18. Synthetic Melanin E-Ink.

    Science.gov (United States)

    Chang, Lingqian; Chen, Feng; Zhang, Xiaokang; Kuang, Tairong; Li, Mi; Hu, Jiaming; Shi, Junfeng; Lee, Ly James; Cheng, Huanyu; Li, Yiwen

    2017-05-17

    Extensive efforts have been devoted to the development of surfactant-free electronic ink (E-ink) with excellent display resolution for high-definition resolution display. Herein, we report the use of polydopamine-based synthetic melanin, a class of functional nanoparticles with similar chemical compositions and physical properties to those of naturally occurring melanin, as a new E-ink material. It was found that such E-ink displays could achieve ultrahigh resolution (>10 000 ppi) and low power consumption (operation voltage of only 1 V) in aqueous solutions. Interestingly, simple oxidation of synthetic melanin nanoparticles enables the generation of intrinsic fluorescence, allowing further development of fluorescent E-ink displays with nanoscale resolution. We describe these bioinspired materials in an initial proof-of-concept study and propose that synthetic melanin nanoparticles will be suitable for electronic nanoinks with a potential wide range of applications in molecular patterning and fluorescence bioimaging.

  19. Is pigment patterning in fish skin determined by the Turing mechanism?

    Science.gov (United States)

    Watanabe, Masakatsu; Kondo, Shigeru

    2015-02-01

    More than half a century ago, Alan Turing postulated that pigment patterns may arise from a mechanism that could be mathematically modeled based on the diffusion of two substances that interact with each other. Over the past 15 years, the molecular and genetic tools to verify this prediction have become available. Here, we review experimental studies aimed at identifying the mechanism underlying pigment pattern formation in zebrafish. Extensive molecular genetic studies in this model organism have revealed the interactions between the pigment cells that are responsible for the patterns. The mechanism discovered is substantially different from that predicted by the mathematical model, but it retains the property of 'local activation and long-range inhibition', a necessary condition for Turing pattern formation. Although some of the molecular details of pattern formation remain to be elucidated, current evidence confirms that the underlying mechanism is mathematically equivalent to the Turing mechanism.

  20. Macroevolutionary patterns of ultraviolet floral pigmentation explained by geography and associated bioclimatic factors.

    Science.gov (United States)

    Koski, Matthew H; Ashman, Tia-Lynn

    2016-07-01

    Selection driven by biotic interactions can generate variation in floral traits. Abiotic selection, however, also contributes to floral diversity, especially with respect to patterns of pigmentation. Combining comparative studies of floral pigmentation and geography can reveal the bioclimatic factors that may drive macroevolutionary patterns of floral color. We create a molecular phylogeny and measure ultraviolet (UV) floral pattern for 177 species in the Potentilleae tribe (Rosaceae). Species are similar in flower shape and visible color but vary in UV floral pattern. We use comparative approaches to determine whether UV pigmentation variation is associated with geography and/or bioclimatic features (UV-B, precipitation, temperature). Floral UV pattern was present in half of the species, while others were uniformly UV-absorbing. Phylogenetic signal was detected for presence/absence of pattern, but among patterned species, quantitative variation in UV-absorbing area was evolutionarily labile. Uniformly UV-absorbing species tended to experience higher UV-B irradiance. Patterned species occurring at higher altitudes had larger UV-absorbing petal areas, corresponding with low temperature and high UV exposure. This analysis expands our understanding of the covariation of UV-B irradiance and UV floral pigmentation from within species to that among species, and supports the view that abiotic selection is associated with floral diversification among species.

  1. Induction of melanin biosynthesis in Vibrio cholerae.

    OpenAIRE

    Coyne, V E; al-Harthi, L

    1992-01-01

    Vibrio cholerae synthesized the pigment melanin in response to specific physiological conditions that were stressful to the bacterium. Pigmentation was induced when V. cholerae was subjected to hyperosmotic stress in conjunction with elevated growth temperatures (above 30 degrees C). The salt concentration tolerated by V. cholerae was lowered by additional abiotic factors such as acidic starting pH of the growth medium and limitation of organic nutrients. Although the amount of toxin detected...

  2. Aspergillus Cell Wall Melanin Blocks LC3-Associated Phagocytosis to Promote Pathogenicity.

    Science.gov (United States)

    Akoumianaki, Tonia; Kyrmizi, Irene; Valsecchi, Isabel; Gresnigt, Mark S; Samonis, George; Drakos, Elias; Boumpas, Dimitrios; Muszkieta, Laetitia; Prevost, Marie-Christine; Kontoyiannis, Dimitrios P; Chavakis, Triantafyllos; Netea, Mihai G; van de Veerdonk, Frank L; Brakhage, Axel A; El-Benna, Jamel; Beauvais, Anne; Latge, Jean-Paul; Chamilos, Georgios

    2016-01-13

    Concealing pathogen-associated molecular patterns (PAMPs) is a principal strategy used by fungi to avoid immune recognition. Surface exposure of PAMPs during germination can leave the pathogen vulnerable. Accordingly, β-glucan surface exposure during Aspergillus fumigatus germination activates an Atg5-dependent autophagy pathway termed LC3-associated phagocytosis (LAP), which promotes fungal killing. We found that LAP activation also requires the genetic, biochemical or biological (germination) removal of A. fumigatus cell wall melanin. The attenuated virulence of melanin-deficient A. fumigatus is restored in Atg5-deficient macrophages and in mice upon conditional inactivation of Atg5 in hematopoietic cells. Mechanistically, Aspergillus melanin inhibits NADPH oxidase-dependent activation of LAP by excluding the p22phox subunit from the phagosome. Thus, two events that occur concomitantly during germination of airborne fungi, surface exposure of PAMPs and melanin removal, are necessary for LAP activation and fungal killing. LAP blockade is a general property of melanin pigments, a finding with broad physiological implications.

  3. Role of GTP-CHI links PAH and TH in melanin synthesis in silkworm, Bombyx mori.

    Science.gov (United States)

    Chen, Ping; Wang, Jiying; Li, Haiyin; Li, Yan; Chen, Peng; Li, Tian; Chen, Xi; Xiao, Junjie; Zhang, Liang

    2015-08-10

    In insects, pigment patterns are formed by melanin, ommochromes, and pteridines. Here, the effects of pteridine synthesis on melanin formation were studied using 4th instar larvae of a wild-type silkworm strain, dazao (Bombyx mori), with normal color and markings. Results from injected larvae and in vitro integument culture indicated that decreased activity of guanosine triphosphate cyclohydrolase I (GTP-CH I, a rate-limiting enzyme for pteridine synthesis), lowers BH4 (6R-l-erythro-5,6,7,8-tetrahydrobiopterin, a production correlated with GTP-CH I activity) levels and eliminates markings and coloration. The conversion of phenylalanine and tyrosine to melanin was prevented when GTP-CH I was inhibited. When BH4 was added, phenylalanine was converted to tyrosine, and the tyrosine concentration increased. Tyrosine was then converted to melanin to create normal markings and coloration. Decreasing GTP-CH I activity did not affect L-DOPA (3,4-l-dihydroxyphenylalanine). GTP-CH I affected melanin synthesis by generating the BH4 used in two key reaction steps: (1) conversion of phenylalanine to tyrosine by PAH (phenylalanine hydroxylase) and (2) conversion of tyrosine to L-DOPA by TH (tyrosine hydroxylase). Expression profiles of BmGTPCH Ia, BmGTPCH Ib, BmTH, and BmPAH in the integument were consistent with the current findings.

  4. Pigmented hepatocellular adenoma with complete CD34 immunostaining pattern: A diagnostic dilemma

    Directory of Open Access Journals (Sweden)

    Mukul Vij

    2012-01-01

    Full Text Available WHO defines hepatocellular adenoma (HCA as a benign tumor composed of cells closely resembling normal hepatocytes, which are arranged in plates separated by sinusoids. It is more common in women. The present concerns a 41 years female who was found to have a mass lesion in liver on ultrasound while undergoing routine evaluation for dyspepsia. Computed tomography scan of abdomen showed 10 × 8 cm lesion in liver. Extended left hepatectomy was performed. Grossly hepatic cut surface showed circumscribed tumor with dark gray or black color. Microscopy revealed hepatocellular adenoma with abundant Dubin Johnson like pigment deposition. CD34 immunostaining showed complete sinusoidal pattern. We labeled the tumor as pigmented hepatic adenoma with complete CD34 staining pattern. To the best of author′s knowledge only eight cases of pigmented hepatocellular adenoma are described in world literature.

  5. Metabolism and Pigmentation Patterns during Metamorphosis of Plaice (Pleuronectes platessa) larvae

    DEFF Research Database (Denmark)

    Christensen, Mette Nørregaard; Korsgaard, Bodil

    1999-01-01

    Protein metabolism, growth and pigmentation patterns were studied during the process of metamorphosis in the plaice Pleuronectes platessa. Based on the morphological and concurrent metabolic observations the process of metamorphosis could be divided into three different phases: (1) premetamorphosis...... and DNA of the larvae. An increasing calcium concentration indicated the beginning of skeleton ossification. Growth during this phase was primarily hyperplastic as indicated by an increase in DNA per larva. Protein catabolism dominated, as indicated by an increase in the carbon to nitrogen ratio....... Calcium assimilation reached a plateau depicting complete ossification of the skeleton. Lipid catabolism dominated by the end of the metamorphosis process. Pigmentation appeared to develop in two marked phases. During premetamorphosis larval melanophores and xanthophores dominated the pigmentation pattern...

  6. Melanin concentration gradients in modern and fossil feathers.

    Directory of Open Access Journals (Sweden)

    Daniel J Field

    Full Text Available In birds and feathered non-avian dinosaurs, within-feather pigmentation patterns range from discrete spots and stripes to more subtle patterns, but the latter remain largely unstudied. A ∼55 million year old fossil contour feather with a dark distal tip grading into a lighter base was recovered from the Fur Formation in Denmark. SEM and synchrotron-based trace metal mapping confirmed that this gradient was caused by differential concentration of melanin. To assess the potential ecological and phylogenetic prevalence of this pattern, we evaluated 321 modern samples from 18 orders within Aves. We observed that the pattern was found most frequently in distantly related groups that share aquatic ecologies (e.g. waterfowl Anseriformes, penguins Sphenisciformes, suggesting a potential adaptive function with ancient origins.

  7. Pigments, parasites and personalitiy: towards a unifying role for steroid hormones?

    Directory of Open Access Journals (Sweden)

    Silje Kittilsen

    Full Text Available A surging interest in the evolution of consistent trait correlations has inspired research on pigment patterns as a correlate of behavioural syndromes, or "animal personalities". Associations between pigmentation, physiology and health status are less investigated as potentially conserved trait clusters. In the current study, lice counts performed on farmed Atlantic salmon Salmo salar naturally infected with ectoparasitic sea lice Lepeophtheirus salmonis showed that individual fish with high incidence of black melanin-based skin spots harboured fewer female sea lice carrying egg sacs, compared to less pigmented fish. There was no significant association between pigmentation and lice at other developmental stages, suggesting that host factors associated with melanin-based pigmentation may modify ectoparasite development to a larger degree than settlement. In a subsequent laboratory experiment a strong negative correlation between skin spots and post-stress cortisol levels was revealed, with less pigmented individuals showing a more pronounced cortisol response to acute stress. The observation that lice prevalence was strongly increased on a fraction of sexually mature male salmon which occurred among the farmed fish further supports a role for steroid hormones as mediators of reduced parasite resistance. The data presented here propose steroid hormones as a proximate cause for the association between melanin-based pigmentation and parasites. Possible fundamental and applied implications are discussed.

  8. Isolation of a novel strain of Aeromonas media producing high levels of DOPA-melanin and assessment of the photoprotective role of the melanin in bioinsecticide applications.

    Science.gov (United States)

    Wan, X; Liu, H M; Liao, Y; Su, Y; Geng, J; Yang, M Y; Chen, X D; Shen, P

    2007-12-01

    To isolate a bacterium that produces high yield of melanin and to examine the effect of this bacterial pigment on the efficacy of a bioinsecticide. A novel melanin-producing bacterium, designated as strain WS, was isolated from the East Lake, Wuhan, China. Taxonomic studies of this strain indicate that it belongs to Aeromonas media. Physicochemical analysis of the pigment produced by strain WS (melanin WS) suggests that it is the authentic 3,4-dihydroxyphenylalanine (DOPA)-melanin. This melanin and that produced by Pseudomonas maltophilia P28 (melanin P28) share many biophysical properties, but the yield of the melanin WS is significantly higher than that of the melanin P28. In addition, the melanin WS appears to be more effective in the protection of a bioinsecticide against ultraviolet (UV) or solar radiation. At the concentration of 10 ppm, the melanin P28 exhibited no photoprotective effect on the bioinsecticide against UV radiation; in contrast, 5 ppm of melanin WS displayed an obvious protective effect. Similarly, the melanin WS displayed more protective effect on the bioinsecticide against solar radiation than the melanin P28 did over a 4-day period, with the effect being more dramatic for the last 2 days. We have isolated a novel bacterial strain of A. media that produces high levels of melanin. The melanin produced by this strain offers effective photoprotection of a commercial bioinsecticide BTI against UV and solar radiation. Our study suggests that the melanin produced by our newly isolated A. media strain has the potential to be used as a general photoprotective agent for bioinsecticides.

  9. Phytoplankton pigment patterns and community composition in the northern South China Sea during winter

    Science.gov (United States)

    Zhai, Hongchang; Ning, Xiuren; Tang, Xuexi; Hao, Qiang; Le, Fengfeng; Qiao, Jing

    2011-03-01

    Phytoplankton pigment patterns and community composition were investigated in the northern South China Sea using high-performance liquid chromatography and the CHEMTAX software from February 11 to 23, 2009. We recognized four different vertical distribution patterns of pigments: chlorophyll a (Chi a)-like type, divinyl chlorophyll a (DV Chi a) type, even distribution type, and surface type. The average value of ratios of accessory photo-protective pigments (APP) to accessory photo-synthetic pigments was 0.89±0.63 in the upper 50 m and 0.16±0.06 below 50 m depth. With increasing depth, APP decreased and photo-synthetically active radiation was attenuated. There was an obvious succession in the phytoplankton community from inshore to the open sea. Diatoms were dominant in the inshore region, while pelagophytes, Prochlorococcus, cyanobacteria and prymnesiophytes were dominant in the open sea. The vertical distribution of phytoplankton also differed greatly from inshore to the open sea. In the coastal and shelf region, diatoms were important components in the whole water column. Cyanobacteria also had a high abundance at the Subsurface Chlorophyll a Maxima (SCM) in the shelf region. In the slope and open sea, Prochlorococcus and cyanobacteria were important groups above the SCM, while pelagophytes dominated below the SCM.

  10. Phytoplankton pigment patterns and community composition in the northern South China Sea during winter

    Institute of Scientific and Technical Information of China (English)

    ZHAI Hongchang; NING Xiuren; TANG Xuexi; HAO Qiang; LE Fengfeng; QIAO Jing

    2011-01-01

    Phytoplankton pigment patterns and community composition were investigated in the northern South China Sea using high-performance liquid chromatography and the CHEMTAX software from February 11 to 23, 2009. We recognized four different vertical distribution patterns of pigments: chlorophyll a (Chl a)-like type, divinyl chlorophyll a (DV Chl a) type, even distribution type, and surface type. The average value of ratios of accessory photo-protective pigments (APP) to accessory photo-synthetic pigments was 0.89±0.63 in the upper 50 m and 0.16±0.06 below 50 m depth. With increasing depth, APP decreased and photo-synthetically active radiation was attenuated. There was an obvious succession in the phytoplankton community from inshore to the open sea. Diatoms were dominant in the inshore region, while pelagophytes, Prochlorococcus,cyanobacteria and prymnesiophytes were dominant in the open sea. The vertical distribution of phytoplankton also differed greatly from inshore to the open sea. In the coastal and shelf region,diatoms were important components in the whole water column. Cyanobacteria also had a high abundance at the Subsurface Chlorophyll a Maxima (SCM) in the shelf region. In the slope and open sea, Prochlorococcus and cyanobacteria were important groups above the SCM, while pelagophytes dominated below the SCM.

  11. Electronic structure calculations of ESR parameters of melanin units.

    Science.gov (United States)

    Batagin-Neto, Augusto; Bronze-Uhle, Erika Soares; Graeff, Carlos Frederico de Oliveira

    2015-03-21

    Melanins represent an important class of natural pigments present in plants and animals that are currently considered to be promising materials for applications in optic and electronic devices. Despite their interesting properties, some of the basic features of melanins are not satisfactorily understood, including the origin of their intrinsic paramagnetism. A number of experiments have been performed to investigate the electron spin resonance (ESR) response of melanin derivatives, but until now, there has been no consensus regarding the real structure of the paramagnetic centers involved. In this work, we have employed electronic structure calculations to evaluate the ESR parameters of distinct melanin monomers and dimers in order to identify the possible structures associated with unpaired spins in this biopolymer. The g-factors and hyperfine constants of the cationic, anionic and radicalar structures were investigated. The results confirm the existence of at least two distinct paramagnetic centers in melanin structure, identifying the chemical species associated with them and their roles in electrical conductivity.

  12. Elemental characterisation of melanin in feathers via synchrotron X-ray imaging and absorption spectroscopy

    Science.gov (United States)

    Edwards, Nicholas P.; van Veelen, Arjen; Anné, Jennifer; Manning, Phillip L.; Bergmann, Uwe; Sellers, William I.; Egerton, Victoria M.; Sokaras, Dimosthenis; Alonso-Mori, Roberto; Wakamatsu, Kazumasa; Ito, Shosuke; Wogelius, Roy A.

    2016-09-01

    Melanin is a critical component of biological systems, but the exact chemistry of melanin is still imprecisely known. This is partly due to melanin’s complex heterogeneous nature and partly because many studies use synthetic analogues and/or pigments extracted from their natural biological setting, which may display important differences from endogenous pigments. Here we demonstrate how synchrotron X-ray analyses can non-destructively characterise the elements associated with melanin pigment in situ within extant feathers. Elemental imaging shows that the distributions of Ca, Cu and Zn are almost exclusively controlled by melanin pigment distribution. X-ray absorption spectroscopy demonstrates that the atomic coordination of zinc and sulfur is different within eumelanised regions compared to pheomelanised regions. This not only impacts our fundamental understanding of pigmentation in extant organisms but also provides a significant contribution to the evidence-based colour palette available for reconstructing the appearance of fossil organisms.

  13. Elemental characterisation of melanin in feathers via synchrotron X-ray imaging and absorption spectroscopy

    Science.gov (United States)

    Edwards, Nicholas P.; van Veelen, Arjen; Anné, Jennifer; Manning, Phillip L.; Bergmann, Uwe; Sellers, William I.; Egerton, Victoria M.; Sokaras, Dimosthenis; Alonso-Mori, Roberto; Wakamatsu, Kazumasa; Ito, Shosuke; Wogelius, Roy A.

    2016-01-01

    Melanin is a critical component of biological systems, but the exact chemistry of melanin is still imprecisely known. This is partly due to melanin’s complex heterogeneous nature and partly because many studies use synthetic analogues and/or pigments extracted from their natural biological setting, which may display important differences from endogenous pigments. Here we demonstrate how synchrotron X-ray analyses can non-destructively characterise the elements associated with melanin pigment in situ within extant feathers. Elemental imaging shows that the distributions of Ca, Cu and Zn are almost exclusively controlled by melanin pigment distribution. X-ray absorption spectroscopy demonstrates that the atomic coordination of zinc and sulfur is different within eumelanised regions compared to pheomelanised regions. This not only impacts our fundamental understanding of pigmentation in extant organisms but also provides a significant contribution to the evidence-based colour palette available for reconstructing the appearance of fossil organisms. PMID:27658854

  14. Bird Integumentary Melanins: Biosynthesis, Forms, Function and Evolution

    Directory of Open Access Journals (Sweden)

    Ismael Galván

    2016-04-01

    Full Text Available Melanins are the ubiquitous pigments distributed in nature. They are one of the main pigments responsible for colors in living cells. Birds are among the most diverse animals regarding melanin-based coloration, especially in the plumage, although they also pigment bare parts of the integument. This review is devoted to the main characteristics of bird melanins, including updated views of the formation and nature of melanin granules, whose interest has been raised in the last years for inferring the color of extinct birds and non-avian theropod dinosaurs using resistant fossil feathers. The molecular structure of the two main types of melanin, eumelanin and pheomelanin, and the environmental and genetic factors that regulate avian melanogenesis are also presented, establishing the main relationship between them. Finally, the special functions of melanin in bird feathers are also discussed, emphasizing the aspects more closely related to these animals, such as honest signaling, and the factors that may drive the evolution of pheomelanin and pheomelanin-based color traits, an issue for which birds have been pioneer study models.

  15. Bird Integumentary Melanins: Biosynthesis, Forms, Function and Evolution.

    Science.gov (United States)

    Galván, Ismael; Solano, Francisco

    2016-04-08

    Melanins are the ubiquitous pigments distributed in nature. They are one of the main pigments responsible for colors in living cells. Birds are among the most diverse animals regarding melanin-based coloration, especially in the plumage, although they also pigment bare parts of the integument. This review is devoted to the main characteristics of bird melanins, including updated views of the formation and nature of melanin granules, whose interest has been raised in the last years for inferring the color of extinct birds and non-avian theropod dinosaurs using resistant fossil feathers. The molecular structure of the two main types of melanin, eumelanin and pheomelanin, and the environmental and genetic factors that regulate avian melanogenesis are also presented, establishing the main relationship between them. Finally, the special functions of melanin in bird feathers are also discussed, emphasizing the aspects more closely related to these animals, such as honest signaling, and the factors that may drive the evolution of pheomelanin and pheomelanin-based color traits, an issue for which birds have been pioneer study models.

  16. Melanin-binding radiopharmaceuticals

    Energy Technology Data Exchange (ETDEWEB)

    Packer, S; Fairchild, R G; Watts, K P; Greenberg, D; Hannon, S J

    1980-01-01

    The scope of this paper is limited to an analysis of the factors that are important to the relationship of radiopharmaceuticals to melanin. While the authors do not attempt to deal with differences between melanin-binding vs. melanoma-binding, a notable variance is assumed. (PSB)

  17. Influence of variation in melanin content on absorbance spectra of liquid skin phantoms

    CSIR Research Space (South Africa)

    Smit, Jacoba E

    2010-09-01

    Full Text Available , Melanin Skin pigmentsMelanin (epidermis), Haemoglobin (dermis), Bilirubin, Carotene, Keratin Melanocytes • Located at epidermal-dermal junction • Melanosomes • Melanin biosynthesis • In contact with ~ 40 keratinocytes Slide 4 of 41 © CSIR... due to keratin. More realistic phantoms – adding keratin • Comparison between the PheroidTM phantoms and melanosomes from different skin phototypes could not be made. To verify the true amount to which these phantoms represent real skin, such a...

  18. Cardiocondyla pirata sp. n. - a new Philippine ant with enigmatic pigmentation pattern (Hymenoptera, Formicidae).

    Science.gov (United States)

    Seifert, Bernhard; Frohschammer, Sabine

    2013-01-01

    A new species of the ant genus Cardiocondyla Emery, 1869 - Cardiocondyla pirata sp. n. - is described from the Philippines. The species belongs to an Indo-Malayan group of six species that is characterized by workers having a strongly bilobate postpetiolar sternite and a thickset mesosoma with strongly convex dorsal profile as well as wingless, ergatoid males with sickle-shaped mandibles. The female castes show a pigmentation pattern not known from any ant worldwide. If having any adaptive value, a possible function of this structure is supposed to be visual dissolution of body shape in order to irritate predators.

  19. Decolorization of synthetic melanins by crude laccases of Lentinus polychrous Lév.

    Science.gov (United States)

    Khammuang, Saranyu; Sarnthima, Rakrudee

    2013-01-01

    Melanins are complex natural pigments that darken the skin and are difficult to degrade. This study evaluated synthetic melanin decolorization by the crude laccase from fungus Lentinus polychrous in the absence and presence of selected redox mediators. The greatest melanin decolorization activity was 87 % at pH 6.5 within 3 h in the presence of 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonate) diammonium salt (ABTS), whereas only about 22 % melanin decolorized at pH 5.0 in case of no mediator. The optimum temperatures for melanin decolorization in the absence and presence of ABTS were 55 and 35°C, respectively. Using a natural redox mediator, 1.0 mmol/L vanillin leads to 45 % melanin decolorization. Our results suggest the possibility of applying vanillin for L. polychrous laccase-catalyzed decolorization of melanin.

  20. Keratinocyte-derived laminin-332 protein promotes melanin synthesis via regulation of tyrosine uptake.

    Science.gov (United States)

    Chung, Heesung; Jung, Hyejung; Lee, Jung-Hyun; Oh, Hye Yun; Kim, Ok Bin; Han, Inn-Oc; Oh, Eok-Soo

    2014-08-01

    Melanocytes, which produce the pigment melanin, are known to be closely regulated by neighboring keratinocytes. However, how keratinocytes regulate melanin production is unclear. Here we report that melanin production in melanoma cells (B16F10 and MNT-1) was increased markedly on a keratinocyte-derived extracellular matrix compared with a melanoma cell-derived extracellular matrix. siRNA-mediated reduction of keratinocyte-derived laminin-332 expression decreased melanin synthesis in melanoma cells, and laminin-332, but not fibronectin, enhanced melanin content and α-melanocyte-stimulating hormone-regulated melanin production in melanoma cells. Similar effects were observed in human melanocytes. Interestingly, however, laminin-332 did not affect the expression or activity of tyrosinase. Instead, laminin-332 promoted the uptake of extracellular tyrosine and, subsequently, increased intracellular levels of tyrosine in both melanocytes and melanoma cells. Taken together, these data strongly suggest that keratinocyte-derived laminin-332 contributes to melanin production by regulating tyrosine uptake.

  1. Epidermal melanin absorption in human skin

    Science.gov (United States)

    Norvang Nilsen, Lill T.; Fiskerstrand, Elisanne J.; Nelson, J. Stuart; Berns, Michael W.; Svaasand, Lars O.

    1996-01-01

    The principle of laser induced selective photothermolysis is to induced thermal damage to specific targets in such a manner that the temperature of the surrounding tissue is maintained below the threshold for thermal damage. The selectivity is obtained by selection of a proper wavelength and pulse duration. The technique is presently being used in the clinic for removal of port-wine stains. The presence of melanin in the epidermal layer can represent a limitation to the selectivity. Melanin absorption drops off significantly with increasing wavelength, but is significant in the entire wavelength region where the blood absorption is high. Treatment of port-wine stain in patients with high skin pigmentation may therefore give overheating of the epidermis, resulting in epidermal necrosis. Melanosomal heating is dependent on the energy and duration of the laser pulse. The heating mechanism for time scales less than typically 1 microsecond(s) corresponds to a transient local heating of the individual melanosomes. For larger time scales, heat diffusion out of the melanosomes become of increased importance, and the temperature distribution will reach a local steady state condition after typically 10 microsecond(s) . For even longer pulse duration, heat diffusing from neighboring melanosomes becomes important, and the temperature rise in a time scale from 100 - 500 microsecond(s) is dominated by this mechanism. The epidermal heating during the typical 450 microsecond(s) pulse used for therapy is thus dependent on the average epidermal melanin content rather than on the absorption coefficient of the individual melanosomes. This study will present in vivo measurements of the epidermal melanin absorption of human skin when exposed to short laser pulses (< 0.1 microsecond(s) ) from a Q-switched ruby laser and with long laser pulses (approximately 500 microsecond(s) ) from a free-running ruby laser or a long pulse length flashlamp pumped dye laser. The epidermal melanin

  2. Condition-dependent expression of melanin-based coloration in the Eurasian kestrel

    NARCIS (Netherlands)

    Piault, Romain; van den Brink, Valentijn; Roulin, Alexandre

    2012-01-01

    Melanin is the most common pigment in animal integuments and is responsible for some of the most striking ornaments. A central tenet of sexual selection theory states that melanin-based traits can signal absolute individual quality in any environment only if their expression is condition-dependent.

  3. Condition-dependent expression of melanin-based coloration in the Eurasian kestrel

    NARCIS (Netherlands)

    Piault, Romain; van den Brink, Valentijn; Roulin, Alexandre

    Melanin is the most common pigment in animal integuments and is responsible for some of the most striking ornaments. A central tenet of sexual selection theory states that melanin-based traits can signal absolute individual quality in any environment only if their expression is condition-dependent.

  4. (Pheo)melanin photosensitizes UVA-induced DNA damage in cultured human melanocytes

    NARCIS (Netherlands)

    Wenczl, E.; Schans, G.P. van der; Roza, L.; Kolb, R.M.; Timmerman, A.J.; Smit, N.P.M.; Pavel, S.; Schothorst, A.A.

    1998-01-01

    The question of whether melanins are photoprotecting and/or photosensitizing in human skin cells continues to be debated. To evaluate the role of melanin upon UVA irradiation, DNA single-strand breaks (ssb) were measured in human melanocytes differing only in the amount of pigment produced by

  5. (Pheo)melanin photosensitizes UVA-induced DNA damage in cultured human melanocytes

    NARCIS (Netherlands)

    Wenczl, E.; Schans, G.P. van der; Roza, L.; Kolb, R.M.; Timmerman, A.J.; Smit, N.P.M.; Pavel, S.; Schothorst, A.A.

    1998-01-01

    The question of whether melanins are photoprotecting and/or photosensitizing in human skin cells continues to be debated. To evaluate the role of melanin upon UVA irradiation, DNA single-strand breaks (ssb) were measured in human melanocytes differing only in the amount of pigment produced by cultur

  6. Antiradiation properties of melanin

    Directory of Open Access Journals (Sweden)

    Bushmanov A.Ju.

    2014-12-01

    Full Text Available Aim: to examine the therapeutic efficiency of melanin administered to mice after irradiation at lethal and sublethal doses. Material and methods: Survival and hematological states were studied on CD-1 mice receiving on acute or fractionated whole-body doses on X-rays or gamma-irradiation. Melanin soluble was given with water ad libitum from the first to the 30th-day after irradiation. Results. It was shown that melanin produced a significant therapeutic and protective-therapeutic action against acute radiation injury in the dose range 6,5-7,5 Gy (LD80-LD under our conditions. Cumulative survival melanin treated mice was increased to 14,4%, in control group — 1,9%. After fractionated injury (1 Gy daily, total dose 10 Gy all mice which consumed melanin remained alive, versus 43,7% in control. Melanin decreased radiation-induced damage and stimulated the hematopoiesis recovery after sublethal exposure (5Gy. Conclusion. The results permit to regard melanin as a therapeutic agent for treatment of radiation injuries.

  7. Is there any difference in the photobiological properties of melanins isolated from human blue and brown eyes?

    Science.gov (United States)

    Menon, I A; Basu, P K; Persad, S; Avaria, M; Felix, C C; Kalyanaraman, B

    1987-01-01

    Investigations were carried out to determine whether the melanin present in the blue and brown eyes were eumelanin, the melanin present in black hair and dark skin, or pheomelanin, the melanin present in red hair and the skin of people with red hair. Our results showed that UV-visible irradiation of blue or brown eye melanin did not produce any superoxide. Irradiation of 51Cr-labelled Ehrlich ascites carcinoma cells in the presence of blue or brown eye melanin did not produce significant cell lysis. The electron spin resonance (ESR) signals of blue and brown eye melanins were very similar to those of eumelanin. Comparison of these findings with our previous results indicated that the blue and brown eye melanins are essentially eumelanin. The ESR signals further suggested that in the case of both blue and brown eye melanins the iris, ciliary body, choroid, and retinal pigment epithelium did not differ. PMID:2820463

  8. Pigment pattern evolution by differential deployment of neural crest and post-embryonic melanophore lineages in Danio fishes.

    Science.gov (United States)

    Quigley, Ian K; Turner, Jessica M; Nuckels, Richard J; Manuel, Joan L; Budi, Erine H; MacDonald, Erin L; Parichy, David M

    2004-12-01

    Latent precursors or stem cells of neural crest origin are present in a variety of post-embryonic tissues. Although these cells are of biomedical interest for roles in human health and disease, their potential evolutionary significance has been underappreciated. As a first step towards elucidating the contributions of such cells to the evolution of vertebrate form, we investigated the relative roles of neural crest cells and post-embryonic latent precursors during the evolutionary diversification of adult pigment patterns in Danio fishes. These pigment patterns result from the numbers and arrangements of embryonic melanophores that are derived from embryonic neural crest cells, as well as from post-embryonic metamorphic melanophores that are derived from latent precursors of presumptive neural crest origin. In the zebrafish D. rerio, a pattern of melanophore stripes arises during the larval-to-adult transformation by the recruitment of metamorphic melanophores from latent precursors. Using a comparative approach in the context of new phylogenetic data, we show that adult pigment patterns in five additional species also arise from metamorphic melanophores, identifying this as an ancestral mode of adult pigment pattern development. By contrast, superficially similar adult stripes of D. nigrofasciatus (a sister species to D. rerio) arise by the reorganization of melanophores that differentiated at embryonic stages, with a diminished contribution from metamorphic melanophores. Genetic mosaic and molecular marker analyses reveal evolutionary changes that are extrinsic to D. nigrofasciatus melanophore lineages, including a dramatic reduction of metamorphic melanophore precursors. Finally, interspecific complementation tests identify a candidate genetic pathway for contributing to the evolutionary reduction in metamorphic melanophores and the increased contribution of early larval melanophores to D. nigrofasciatus adult pigment pattern development. These results

  9. [Generation of superoxides during the interaction of melanins with oxygen].

    Science.gov (United States)

    Lapina, V A; Dontsov, A E; Ostrovskiĭ, M A

    1984-10-01

    The rate of nitroblue tetrazolium (NBT) reduction by dihydroxyphenylalanine-melanin, pheomelanin and retinal pigment epithelium melanosomes under aerobic conditions (pH 7.4) is low both in the dark and upon illumination, but increases drastically in the presence of cetyltrimethylammonium bromide (CTAB). Under these conditions, the light insignificantly stimulates NBT reduction (1.3-fold). The reaction is effectively inhibited by superoxide dismutase. This suggests that superoxide anions (O2-. are formed as intermediate reaction products in the course of NBT reduction by melanins. At alkaline values of pH (greater than or equal to 9.0), the O2-.-dependent reduction of NBT can also take place in the absence of CTAB. In contrast with oxidation of photoreduced riboflavin, the melanin oxidation by O2 cannot induce lipid peroxidation. It is concluded that O2-. generation via melanin oxidation of melanosomes occurs only under non-physiological conditions and can hardly take place in vivo.

  10. Activation of Melanin Synthesis in Alternaria infectoria by Antifungal Drugs.

    Science.gov (United States)

    Fernandes, Chantal; Prados-Rosales, Rafael; Silva, Branca M A; Nakouzi-Naranjo, Antonio; Zuzarte, Mónica; Chatterjee, Subhasish; Stark, Ruth E; Casadevall, Arturo; Gonçalves, Teresa

    2015-12-28

    The importance of Alternaria species fungi to human health ranges from their role as etiological agents of serious infections with poor prognoses in immunosuppressed individuals to their association with respiratory allergic diseases. The present work focuses on Alternaria infectoria, which was used as a model organism of the genus, and was designed to unravel melanin production in response to antifungals. After we characterized the pigment produced by A. infectoria, we studied the dynamics of 1,8-dihydroxynaphthalene (DHN)-melanin production during growth, the degree of melanization in response to antifungals, and how melanization affected susceptibility to several classes of therapeutic drugs. We demonstrate that A. infectoria increased melanin deposition in cell walls in response to nikkomycin Z, caspofungin, and itraconazole but not in response to fluconazole or amphotericin B. These results indicate that A. infectoria activates DHN-melanin synthesis in response to certain antifungal drugs, possibly as a protective mechanism against these drugs. Inhibition of DHN-melanin synthesis by pyroquilon resulted in a lower minimum effective concentration (MEC) of caspofungin and enhanced morphological changes (increased hyphal balloon size), characterized by thinner and less organized A. infectoria cell walls. In summary, A. infectoria synthesizes melanin in response to certain antifungal drugs, and its susceptibility is influenced by melanization, suggesting the therapeutic potential of drug combinations that affect melanin synthesis.

  11. Effect of pH on Paramagnetic Centers in Cladosporium cladosporioides Melanin

    Science.gov (United States)

    Pilawa, B.; Buszman, E.; Gondzik, A.; Wilczyński, S.; Zdybel, M.; Witoszyńska, T.; Wilczok, T.

    2006-07-01

    Paramagnetic centers in melanin existing in pigmented soil fungi Cladosporium cladosporioides cultured at acidic (4, 5, 6), neutral (7), and alkaline (8) pH were studied by EPR method. o-semiquinone free radicals (g: 2.0032-2.0040) concentration in melanin biopolymer increased for pH from 4 to 6, decreased at pH 7, and reached the maximum value at pH 8. It may be expected that melanin free radicals reactions with small molecules (metal ions, drugs) are the most effective at pH between 6 and 8. Slow spin-lattice relaxation processes exist in the all studied melanin samples.

  12. Differential Antifungal Activity of Human and Cryptococcal Melanins with Structural Discrepancies

    Directory of Open Access Journals (Sweden)

    Néstor Correa

    2017-07-01

    Full Text Available Melanin is a pigment found in all biological kingdoms, and plays a key role in protection against ultraviolet radiation, oxidizing agents, and ionizing radiation damage. Melanin exerts an antimicrobial activity against bacteria, fungi, and parasites. We demonstrated an antifungal activity of synthetic and human melanin against Candida sp. The members of the Cryptococcus neoformans and C. gattii species complexes are capsulated yeasts, which cause cryptococcosis. For both species melanin is an important virulence factor. To evaluate if cryptococcal and human melanins have antifungal activity against Cryptococcus species they both were assayed for their antifungal properties and physico-chemical characters. Melanin extracts from human hair and different strains of C. neoformans (n = 4 and C. gattii (n = 4 were investigated. The following minimum inhibitory concentrations were found for different melanins against C. neoformans and C. gattii were (average/range: 13.7/(7.8–15.6 and 19.5/(15.6–31.2 μg/mL, respectively, for human melanin; 273.4/(125–>500 and 367.2/(125.5–>500 μg/mL for C. neoformans melanin and 125/(62.5–250 and 156.2/(62–250 μg/mL for C. gattii melanin. Using Scanning Electron Microscopy we observed that human melanin showed a compact conformation and cryptococcal melanins exposed an amorphous conformation. Infrared spectroscopy (FTIR showed some differences in the signals related to C-C bonds of the aromatic ring of the melanin monomers. High Performance Liquid Chromatography established differences in the chromatograms of fungal melanins extracts in comparison with human and synthetic melanin, particularly in the retention time of the main compound of fungal melanin extracts and also in the presence of minor unknown compounds. On the other hand, MALDI-TOF-MS analysis showed slight differences in the spectra, specifically the presence of a minor intensity ion in synthetic and human melanin, as well as in some fungal

  13. Melanins and melanogenesis: methods, standards, protocols.

    Science.gov (United States)

    d'Ischia, Marco; Wakamatsu, Kazumasa; Napolitano, Alessandra; Briganti, Stefania; Garcia-Borron, José-Carlos; Kovacs, Daniela; Meredith, Paul; Pezzella, Alessandro; Picardo, Mauro; Sarna, Tadeusz; Simon, John D; Ito, Shosuke

    2013-09-01

    Despite considerable advances in the past decade, melanin research still suffers from the lack of universally accepted and shared nomenclature, methodologies, and structural models. This paper stems from the joint efforts of chemists, biochemists, physicists, biologists, and physicians with recognized and consolidated expertise in the field of melanins and melanogenesis, who critically reviewed and experimentally revisited methods, standards, and protocols to provide for the first time a consensus set of recommended procedures to be adopted and shared by researchers involved in pigment cell research. The aim of the paper was to define an unprecedented frame of reference built on cutting-edge knowledge and state-of-the-art methodology, to enable reliable comparison of results among laboratories and new progress in the field based on standardized methods and shared information.

  14. Emergence Time and Skin Melanin Spot Patterns Do Not Correlate with Growth Performance, Social Competitive Ability or Stress Response in Farmed Rainbow Trout

    Directory of Open Access Journals (Sweden)

    Manuel Gesto

    2017-06-01

    Full Text Available In wild salmonid fish, specific individual behavioral traits have been correlated with the timing of fry emergence from their gravel spawning nests; Early emerging fish display more aggressive behavior and have a higher probability of becoming socially dominant, compared to fish that emerge at a later stage. Apart from aggression and dominance, other behavioral and metabolic traits, such as boldness, metabolic rate, or growth, have also been linked to emergence time. Altogether, the traits of early- and late-emerging fish resemble those of the proactive and reactive stress-coping style, respectively. As proactive fish are considered more resilient to stress, it may be desirable to select these for aquaculture production. However, it is currently unclear to what extent the link between emergence time and stress-coping styles is maintained in the selective breeding of farmed fish. In the present study, eyed eggs from a commercial supplier were hatched, and larvae fractionated according to their emergence time. Later on, juvenile fish from different emergence fractions were subjected to a stress challenge and also tested to evaluate their competitive ability for food. Beyond some slight dissimilarities in the acute stress responses, emergence fraction displayed no correlation with growth rates, or the ability to compete for feed. Within the whole group of fish utilized in the experiments, no relationship between skin melanin spot pattern and growth performance, stress response intensity, or competitive ability was found. Altogether, the differences in physiological traits related to emergence time were not as strong as those found in earlier studies. It is hypothesized, that the origin and degree of domestication of the fish might be partly responsible for this. The predictive value of skin spots or emergence time to infer the fish stress coping style in farmed fish is also discussed.

  15. Transcriptome-wide analysis reveals candidate genes responsible for the asymmetric pigment pattern in scallop Patinopecten yessoensis

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    XJ Sun

    2016-09-01

    Full Text Available Transcriptome-wide analysis reveals candidate genes responsible for the asymmetric pigment pattern in scallop Patinopecten yessoensis XJ Sun, LQ Zhou, ZH Liu, B Wu, AG Yang Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China Accepted September 14, 2016 Abstract Yesso scallop Patinopecten yessoensis is an economically important marine bivalve species in aquaculture and fishery in Asian countries. The colors of the left and right shells are obviously distinct, typically having reddish-brown for the left and white for the right. This left-right asymmetric pigment pattern is a very unique phenomenon among invertebrates, whereas the molecular mechanisms that control regional differences in pigmentation are not clear. To better understand the left-right asymmetric pigment pattern, we apply Illumina digital gene expression (DGE to characterize the gene expression profiles in left and right mantle tissues, and identify five differentially expressed genes, including Cytochrome P450 and other four unknown genes. Among the five genes, one gene shows significantly higher expression in the right mantle, while other four exhibit significantly higher expression in the left mantle. We further validate the DGE results by using quantitative real-time PCR for P450, resulting in approximately 32-fold higher expression in the left mantle than that in the right mantle. These findings will not only help assist our understanding of the sophisticated processes of shell pigmentation in scallops, but also provide new insights into the adaptive evolution of phenotypes to maximize survival that underlie the left-right asymmetric pigment pattern in molluscs.

  16. Melanin from the nitrogen-fixing bacterium Azotobacter chroococcum: a spectroscopic characterization.

    Science.gov (United States)

    Banerjee, Aulie; Supakar, Subhrangshu; Banerjee, Raja

    2014-01-01

    Melanins, the ubiquitous hetero-polymer pigments found widely dispersed among various life forms, are usually dark brown/black in colour. Although melanins have variety of biological functions, including protection against ultraviolet radiation of sunlight and are used in medicine, cosmetics, extraction of melanin from the animal and plant kingdoms is not an easy task. Using complementary physicochemical techniques (i.e. MALDI-TOF, FTIR absorption and cross-polarization magic angle spinning solid-state (13)C NMR), we report here the characterization of melanins extracted from the nitrogen-fixing non-virulent bacterium Azotobacter chroococcum, a safe viable source. Moreover, considering dihydroxyindole moiety as the main constituent, an effort is made to propose the putative molecular structure of the melanin hetero-polymer extracted from the bacterium. Characterization of the melanin obtained from Azotobacter chroococcum would provide an inspiration in extending research activities on these hetero-polymers and their use as protective agent against UV radiation.

  17. Role of Melanin in Oncogenesis

    Science.gov (United States)

    2011-08-01

    knockdown of individual enzymes that are specifically involved in melanin biosynthesis phenylalanine hydroxylase , tyrosinase, tyrosine hydroxylase and...with siRNAs directed against melanin biosynthetic enzymes, tyrosinase (siTYR), tyrosine hydroxylase (TYH), phenlyalanine hydroxylase (siPKU), and

  18. Flavonoids and Melanins: a common strategy across two kingdoms.

    Science.gov (United States)

    Carletti, Giorgia; Nervo, Giuseppe; Cattivelli, Luigi

    2014-01-01

    Ultraviolet (UV) radiations alter a number of metabolic functions in vivant. They produce damages to lipids, nucleic acids and proteins, generating reactive oxygen species such as singlet oxygen (O2), hydroxyl radical (HO) and superoxide anion (O2 (-)). Plants and animals, after their water emersion, have developed biochemical mechanisms to protect themselves from that environmental threat through a common strategy. Melanins in animals and flavonoids in plants are antioxidant pigments acting as free radical scavenging mechanisms. Both are phenol compounds constitutively synthesized and enhanced after exposure to UV rays, often conferring a red-brown-dark tissue pigmentation. Noteworthy, beside anti-oxidant scavenging activity, melanins and flavonoids have acquired secondary functions that, both in plants and animals, concern reproductions and fitness. Plants highly pigmented are more resistant to biotic and abiotic stresses. Darker wild vertebrates are generally more aggressive, sexually active and resistant to stress than lighter individuals. Flavonoids have been associated with signal attraction between flowers and insects and with plant-plant interaction. Melanin pigmentation has been proposed as trait in bird communication, acting as honest signals of quality. This review shows how the molecular mechanisms leading to tissue pigmentation have many functional analogies between plants and animals and how their origin lies in simpler organisms such as Cyanobacteria. Comparative studies between plant and animal kingdoms can reveal new insight of the antioxidant strategies in vivant.

  19. Coloration principles of nymphaline butterflies - thin films, melanin, ommochromes and wing scale stacking.

    Science.gov (United States)

    Stavenga, Doekele G; Leertouwer, Hein L; Wilts, Bodo D

    2014-06-15

    The coloration of the common butterflies Aglais urticae (small tortoiseshell), Aglais io (peacock) and Vanessa atalanta (red admiral), belonging to the butterfly subfamily Nymphalinae, is due to the species-specific patterning of differently coloured scales on their wings. We investigated the scales' structural and pigmentary properties by applying scanning electron microscopy, (micro)spectrophotometry and imaging scatterometry. The anatomy of the wing scales appears to be basically identical, with an approximately flat lower lamina connected by trabeculae to a highly structured upper lamina, which consists of an array of longitudinal, parallel ridges and transversal crossribs. Isolated scales observed at the abwing (upper) side are blue, yellow, orange, red, brown or black, depending on their pigmentation. The yellow, orange and red scales contain various amounts of 3-OH-kynurenine and ommochrome pigment, black scales contain a high density of melanin, and blue scales have a minor amount of melanin pigment. Observing the scales from their adwing (lower) side always revealed a structural colour, which is blue in the case of blue, red and black scales, but orange for orange scales. The structural colours are created by the lower lamina, which acts as an optical thin film. Its reflectance spectrum, crucially determined by the lamina thickness, appears to be well tuned to the scales' pigmentary spectrum. The colours observed locally on the wing are also due to the degree of scale stacking. Thin films, tuned pigments and combinations of stacked scales together determine the wing coloration of nymphaline butterflies. © 2014. Published by The Company of Biologists Ltd.

  20. Eumelanin and pheomelanin are predominant pigments in bumblebee (Apidae: Bombus pubescence

    Directory of Open Access Journals (Sweden)

    Carlo Polidori

    2017-05-01

    Full Text Available Background Bumblebees (Hymenoptera: Apidae: Bombus are well known for their important inter- and intra-specific variation in hair (or pubescence color patterns, but the chemical nature of the pigments associated with these patterns is not fully understood. For example, though melanization is believed to provide darker colors, it still unknown which types of melanin are responsible for each color, and no conclusive data are available for the lighter colors, including white. Methods By using dispersive Raman spectroscopy analysis on 12 species/subspecies of bumblebees from seven subgenera, we tested the hypothesis that eumelanin and pheomelanin, the two main melanin types occurring in animals, are largely responsible for bumblebee pubescence coloration. Results Eumelanin and pheomelanin occur in bumblebee pubescence. Black pigmentation is due to prevalent eumelanin, with visible signals of additional pheomelanin, while the yellow, orange, red and brown hairs clearly include pheomelanin. On the other hand, white hairs reward very weak Raman signals, suggesting that they are depigmented. Additional non-melanic pigments in yellow hair cannot be excluded but need other techniques to be detected. Raman spectra were more similar across similarly colored hairs, with no apparent effect of phylogeny and both melanin types appeared to be already used at the beginning of bumblebee radiation. Discussion We suggest that the two main melanin forms, at variable amounts and/or vibrational states, are sufficient in giving almost the whole color range of bumblebee pubescence, allowing these insects to use a single precursor instead of synthesizing a variety of chemically different pigments. This would agree with commonly seen color interchanges between body segments across Bombus species.

  1. A pigmented calcifying odontogenic cyst.

    Science.gov (United States)

    Soames, J V

    1982-04-01

    A case of the pigmented variant of the calcifying odontogenic cyst occurring in a 15-year-old West Indian girl is reported. Melanin pigment was widely distributed and appeared in greatest amount in cells exhibiting the appearance of stellate reticulum. Ultrastructural examination demonstrated large numbers of melanosomes in these cells but relatively few in epithelial ghost cells. The latter contained thick bundles of tonofilaments. Melanocytes were identified and two forms were distinguished, depending on their content of premelanosomes and fully melanized melanosomes.

  2. Fruit over sunbed: carotenoid skin colouration is found more attractive than melanin colouration.

    Science.gov (United States)

    Lefevre, Carmen E; Perrett, David I

    2015-01-01

    Skin colouration appears to play a pivotal part in facial attractiveness. Skin yellowness contributes to an attractive appearance and is influenced both by dietary carotenoids and by melanin. While both increased carotenoid colouration and increased melanin colouration enhance apparent health in Caucasian faces by increasing skin yellowness, it remains unclear, firstly, whether both pigments contribute to attractiveness judgements, secondly, whether one pigment is clearly preferred over the other, and thirdly, whether these effects depend on the sex of the face. Here, in three studies, we examine these questions using controlled facial stimuli transformed to be either high or low in (a) carotenoid colouration, or (b) melanin colouration. We show, firstly, that both increased carotenoid colouration and increased melanin colouration are found attractive compared to lower levels of these pigments. Secondly, we show that carotenoid colouration is consistently preferred over melanin colouration when levels of colouration are matched. In addition, we find an effect of the sex of stimuli with stronger preferences for carotenoids over melanin in female compared to male faces, irrespective of the sex of the observer. These results are interpreted as reflecting preferences for sex-typical skin colouration: men have darker skin than women and high melanization in male faces may further enhance this masculine trait, thus carotenoid colouration is not less desirable, but melanin colouration is relatively more desirable in males compared to females. Taken together, our findings provide further support for a carotenoid-linked health-signalling system that is highly important in mate choice.

  3. Melanin content in melanoma metastases affects the outcome of radiotherapy.

    Science.gov (United States)

    Brożyna, Anna A; Jóźwicki, Wojciech; Roszkowski, Krzysztof; Filipiak, Jan; Slominski, Andrzej T

    2016-04-05

    Melanin possess radioprotective and scavenging properties, and its presence can affect the behavior of melanoma cells, its surrounding environment and susceptibility to the therapy, as showed in vitro experiments. To determine whether melanin presence in melanoma affects the efficiency of radiotherapy (RTH) we evaluated the survival time after RTH treatment in metastatic melanoma patients (n = 57). In another cohort of melanoma patients (n = 84), the relationship between melanin level and pT and pN status was determined. A significantly longer survival time was found in patients with amelanotic metastatic melanomas in comparison to the melanotic ones, who were treated with either RTH or chemotherapy (CHTH) and RTH. These differences were more significant in a group of melanoma patients treated only with RTH. A detailed analysis of primary melanomas revealed that melanin levels were significantly higher in melanoma cells invading reticular dermis than the papillary dermis. A significant reduction of melanin pigmentation in pT3 and pT4 melanomas in comparison to pT1 and T2 tumors was observed. However, melanin levels measured in pT3-pT4 melanomas developing metastases (pN1-3, pM1) were higher than in pN0 and pM0 cases. The presence of melanin in metastatic melanoma cells decreases the outcome of radiotherapy, and melanin synthesis is related to higher disease advancement. Based on our previous cell-based and clinical research and present research we also suggest that inhibition of melanogenesis can improve radiotherapy modalities. The mechanism of relationship between melanogenesis and efficacy of RTH requires additional studies, including larger melanoma patients population and orthotopic, imageable mouse models of metastatic melanoma.

  4. Isolation and characterization of biologically active melanin from Actinoalloteichus sp. MA-32.

    Science.gov (United States)

    Manivasagan, Panchanathan; Venkatesan, Jayachandran; Senthilkumar, Kalimuthu; Sivakumar, Kannan; Kim, Se-Kwon

    2013-07-01

    Melanins are enigmatic pigments and biological macromolecules that are produced by a wide variety of microorganisms including several species of bacteria and fungi. The present study was carried out on isolation and characterization of melanin from marine actinobacteria, Actinoalloteichus sp. MA-32. Medium composition and culture conditions for the melanin production by Actinoalloteichus sp. MA-32 were optimized using two statistical methods: Plackett-Burman design applied to find the key ingredients and conditions for the best yield of melanin production and central composite design used to optimize the concentration of the four significant variables: glycerol, L-tyrosine, NaCl and trace salt solution. The melanin was optimally active at pH 7-9 and temperature 45-60°C and it was most stable up to pH 11 and 4% of NaCl concentration. Melanin was examined by UV-vis absorption spectroscopy and infrared spectrometry. Melanin has potential antibacterial activity as it showed greater antagonistic and it has a strong antioxidant potential observed in the in vitro evaluation of its DPPH radical-scavenging activity, superoxide radical-scavenging activity, nitric oxide-scavenging activity, reducing power and metal chelating activity. The observed activities indicate that melanin might be a novel potential antioxidant. This study suggested that the melanin could potentially be used as a natural antioxidant in the food, cosmetic and pharmaceutical industries.

  5. Pigment patterns in the Arabian Sea: Spatio-temporal variability as observed by ADEOS

    Digital Repository Service at National Institute of Oceanography (India)

    Jadhav, N.A.; Rao, L.V.G.; Panigrahy, R.C.

    The spatial and temporal variations of the near-surface concentration of phytoplankton pigment observed by ADEOS during November 1996 - May 1997 are studied in relation to SST and winds. Monthly composite images from OCTS depict spatial and temporal...

  6. Characterization of melanin produced by a wild-type strain of Bacillus cereus

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jianping; CAI Jun; DENG Yinyue; CHEN Yuehua; REN Gaixin

    2007-01-01

    Bacillus cereus 58 (Bc58)is a UV-resistant wild type strain that has an ability to produce a sorrel pigment induced by L-tyrosine.The Fourier-transform infrared (FT-IR)spectra and chemical tests of its pigment are similar to that of the standard melanin (Sigma).A bioassay shows that the LC50 of a Bacillus thuringiensis (Bt)formulation added with the melanin of Bc58 and exposed to UV for 5 h is 16.1 μg/ml,which is similar to that of the Bt formulation without UV treatment,however,it is almost double that of the Bt formulation exposed to UV without the melanin of Bc58.The result of SDS-PAGE indicates that the melanin of Bc58 can protect the insecticidal crystal proteins from degradation.This suggests that it is an excellent UV protective agent for the insecticidal crystal proteins of the Bt formulation.

  7. Redox activity of melanin from the ink sac of Sepia officinalis by means of colorimetric oxidative assay.

    Science.gov (United States)

    Srisuk, Pathomthat; Correlo, Vitor M; Leonor, Isabel B; Palladino, Pasquale; Reis, Rui L

    2016-01-01

    The redox properties of natural extract from cuttlefish ink sac (Sepia officinalis) and synthetic melanin used as a biomimetic in melanin structural investigation were determined by comparison of this phenol-based heterogeneous pigment with gallic acid used as a standard in Folin-Ciocalteu colorimetric assay widely employed for characterisation of oxidative properties of biomaterials. Reactivity of sepia melanin reported here is much higher than previously indicated and this protocol should allow the redox characterisation of all melanins irrespective of their origin and composition.

  8. Pigment pattern formation in the guppy, Poecilia reticulata, involves the Kita and Csf1ra receptor tyrosine kinases.

    Science.gov (United States)

    Kottler, Verena A; Fadeev, Andrey; Weigel, Detlef; Dreyer, Christine

    2013-07-01

    Males of the guppy (Poecilia reticulata) vary tremendously in their ornamental patterns, which are thought to have evolved in response to a complex interplay between natural and sexual selection. Although the selection pressures acting on the color patterns of the guppy have been extensively studied, little is known about the genes that control their ontogeny. Over 50 years ago, two autosomal color loci, blue and golden, were described, both of which play a decisive role in the formation of the guppy color pattern. Orange pigmentation is absent in the skin of guppies with a lesion in blue, suggesting a defect in xanthophore development. In golden mutants, the development of the melanophore pattern during embryogenesis and after birth is affected. Here, we show that blue and golden correspond to guppy orthologs of colony-stimulating factor 1 receptor a (csf1ra; previously called fms) and kita. Most excitingly, we found that both genes are required for the development of the black ornaments of guppy males, which in the case of csf1ra might be mediated by xanthophore-melanophore interactions. Furthermore, we provide evidence that two temporally and genetically distinct melanophore populations contribute to the adult camouflage pattern expressed in both sexes: one early appearing and kita-dependent and the other late-developing and kita-independent. The identification of csf1ra and kita mutants provides the first molecular insights into pigment pattern formation in this important model species for ecological and evolutionary genetics.

  9. Experimental autoimmune anterior uveitis (EAAU): induction by melanin antigen and suppression by various treatments.

    Science.gov (United States)

    Broekhuyse, R M; Kuhlmann, E D; Winkens, H J

    1993-02-01

    The uveitogenicity of melanin has been a controversial subject for a long time, presumably as a result of the use of ill-defined preparations in the experiments. We have developed procedures for the preparation of purified uveitogenic melanins from the retinal pigment epithelium and choroid that are free from pathogenic retinal photoreceptor proteins. The active melano-antigen is located at the surface of the melanin granules and is probably identical in both tissues. It retains its pathogenicity in hot polar detergent and during in vitro proteolysis, but it is inactivated by macrophage phagocytosis and hydrolysis in hot hydrochloric acid. Lewis rats immunized with microgram doses of bovine retinal pigment epithelial or choroidal melanin develop severe experimental autoimmune anterior uveitis (EAAU) about 10 days later. Retinitis and pinealitis are not observed. Skin melanin prepared in a similar way evokes EAAU as well, but it is only weakly pathogenic. EAAU cannot be transferred by serum, and its development can effectively be inhibited by antibodies to the inciting antigen and by cyclosporin. Vitamin E treatment of the animals causes a delay in its onset. The results indicate that cell-mediated immunity plays a dominant role in the pathogenesis of EAAU. This is the first time it has been shown that purified ocular and skin melanins are able to induce an autoimmune disease. The relevance of this finding for the study of melanin-related immunopathology in man is discussed.

  10. A Non-canonical Melanin Biosynthesis Pathway Protects Aspergillus terreus Conidia from Environmental Stress.

    Science.gov (United States)

    Geib, Elena; Gressler, Markus; Viediernikova, Iuliia; Hillmann, Falk; Jacobsen, Ilse D; Nietzsche, Sandor; Hertweck, Christian; Brock, Matthias

    2016-05-19

    Melanins are ubiquitous pigments found in all kingdoms of life. Most organisms use them for protection from environmental stress, although some fungi employ melanins as virulence determinants. The human pathogenic fungus Aspergillus fumigatus and related Ascomycetes produce dihydroxynaphthalene- (DHN) melanin in their spores, the conidia, and use it to inhibit phagolysosome acidification. However, biosynthetic origin of melanin in a related fungus, Aspergillus terreus, has remained a mystery because A. terreus lacks genes for synthesis of DHN-melanin. Here we identify genes coding for an unusual NRPS-like enzyme (MelA) and a tyrosinase (TyrP) that A. terreus expressed under conidiation conditions. We demonstrate that MelA produces aspulvinone E, which is activated for polymerization by TyrP. Functional studies reveal that this new pigment, Asp-melanin, confers resistance against UV light and hampers phagocytosis by soil amoeba. Unexpectedly, Asp-melanin does not inhibit acidification of phagolysosomes, thus likely contributing specifically to survival of A. terreus conidia in acidic environments.

  11. Biologically derived melanin electrodes in aqueous sodium-ion energy storage devices.

    Science.gov (United States)

    Kim, Young Jo; Wu, Wei; Chun, Sang-Eun; Whitacre, Jay F; Bettinger, Christopher J

    2013-12-24

    Biodegradable electronics represents an attractive and emerging paradigm in medical devices by harnessing simultaneous advantages afforded by electronically active systems and obviating issues with chronic implants. Integrating practical energy sources that are compatible with the envisioned operation of transient devices is an unmet challenge for biodegradable electronics. Although high-performance energy storage systems offer a feasible solution, toxic materials and electrolytes present regulatory hurdles for use in temporary medical devices. Aqueous sodium-ion charge storage devices combined with biocompatible electrodes are ideal components to power next-generation biodegradable electronics. Here, we report the use of biologically derived organic electrodes composed of melanin pigments for use in energy storage devices. Melanins of natural (derived from Sepia officinalis) and synthetic origin are evaluated as anode materials in aqueous sodium-ion storage devices. Na(+)-loaded melanin anodes exhibit specific capacities of 30.4 ± 1.6 mAhg(-1). Full cells composed of natural melanin anodes and λ-MnO2 cathodes exhibit an initial potential of 1.03 ± 0.06 V with a maximum specific capacity of 16.1 ± 0.8 mAhg(-1). Natural melanin anodes exhibit higher specific capacities compared with synthetic melanins due to a combination of beneficial chemical, electrical, and physical properties exhibited by the former. Taken together, these results suggest that melanin pigments may serve as a naturally occurring biologically derived charge storage material to power certain types of medical devices.

  12. Pattern of inner retinal layers involvement in pigmented paravenous retinochoroidal atrophy as determined by SD-OCT: case report.

    Science.gov (United States)

    Junqueira, Daniela Laura Melo; Lopes, Flavio Siqueira Santos; Biteli, Luís Gustavo; Prata, Tiago Santos

    2013-01-01

    Pigmented paravenous retinochoroidal atrophy is an ocular disease characterized by outer retina and choroidal atrophy often with overlying intraretinal bone spicule pigment deposition along the retinal veins. As a rare condition, there is scant information in the literature regarding the pattern of inner retinal layers involvement. We present a case of a 41-year-old white man initially referred for a glaucoma evaluation. Fundoscopy revealed patches of retinochoroidal atrophy and light pigmentation extending from the optic nerve head along the inferior-temporal retinal veins in both eyes. Using different spectral-domain optical coherence tomography (SD-OCT) protocols we identified a significant thinning of the inner retinal layers along the inferior-temporal veins, but with a lucid interval surrounding the optic nerve head. Standard automated perimetry revealed a superior absolute arcuate scotoma sparing the central fixation (good structure-functional correlation). This pattern of inner retinal layers involvement was not previously described. We believe SD-OCT added significantly to the anatomical description of this case. Physicians should consider these new anatomical findings and correlate them with functional status while assessing these patients.

  13. Pattern of inner retinal layers involvement in pigmented paravenous retinochoroidal atrophy as determined by SD-OCT: case report

    Directory of Open Access Journals (Sweden)

    Daniela Laura Melo Junqueira

    2013-12-01

    Full Text Available Pigmented paravenous retinochoroidal atrophy is an ocular disease characterized by outer retina and choroidal atrophy often with overlying intraretinal bone spicule pigment deposition along the retinal veins. As a rare condition, there is scant information in the literature regarding the pattern of inner retinal layers involvement. We present a case of a 41-year-old white man initially referred for a glaucoma evaluation. Fundoscopy revealed patches of retinochoroidal atrophy and light pigmentation extending from the optic nerve head along the inferior-temporal retinal veins in both eyes. Using different spectral-domain optical coherence tomography (SD-OCT protocols we identified a significant thinning of the inner retinal layers along the inferior-temporal veins, but with a lucid interval surrounding the optic nerve head. Standard automated perimetry revealed a superior absolute arcuate scotoma sparing the central fixation (good structure-functional correlation. This pattern of inner retinal layers involvement was not previously described. We believe SD-OCT added significantly to the anatomical description of this case. Physicians should consider these new anatomical findings and correlate them with functional status while assessing these patients.

  14. High-level production of melanin by a novel isolate of Streptomyces kathirae.

    Science.gov (United States)

    Guo, Jing; Rao, Zhiming; Yang, Taowei; Man, Zaiwei; Xu, Meijuan; Zhang, Xian

    2014-08-01

    Forty-five bacterial strains that produced diffusive pigments were isolated from 40 soil samples. Maximum pigment production was from a Streptomyces kathirae strain designated SC-1. The diffused pigment was characterized by UV-visual and infrared spectroscopy, MS and (1) H nuclear magnetic resonance imaging, and was confirmed as melanin. This may be the first report of melanin production by S. kathirae. To enhance melanin production, the culture medium was optimized by conducting a series of batch fermentations in a defined medium, and the results were analysed statistically using a response surface method. The optimal culture medium comprised 3.3 g L(-1) amylodextrine, 37 g L(-1) yeast extract, 5 g L(-1) NaCl, 0.1 g L(-1) CaCl2 and 54.4 μM CuSO4 . The pH of this medium was 6.0. Under optimal conditions, the melanin concentration was maximized at 13.7 g L(-1) , c. 8.6-fold higher than obtained in suboptimal medium. To our knowledge, the results provide novel data on melanin fermentation, and identify an excellent candidate for industrial-scale microbial fermentation of melanin.

  15. Characterization and biological activities of extracellular melanin produced by Schizophyllum commune (Fries).

    Science.gov (United States)

    Arun, G; Eyini, M; Gunasekaran, P

    2015-06-01

    Melanins are enigmatic pigments produced by a wide variety of microorganisms including bacteria and fungi. Here, we have isolated and characterized extracellular melanin from mushroom fungus, Schizophyllum commune. The extracellular dark pigment produced by the broth culture of S. commune, after 21 days of incubation was recovered by hot acid-alkali treatment. The melanin nature of the pigment was characterized by biochemical tests and further, confirmed by UV, IR, EPR, NMR and MALDI-TOF Mass Spectra. Extracellular melanin, at 100 μg/ml, showed significant antibacterial activity against Escherichia coli, Bacillus subtilis, Klebsiella pneumoniae and Pseudomonas fluorescens and antifungal activity against Trichophyton simii and T. rubrum. At a concentration of 50 μg/ml, melanin showed high free radical scavenging activity of DPPH (2,2-diphenyl-1-picrylhydrazyl) indicating its antioxidant potential. It showed concentration dependent inhibition of cell proliferation of Human Epidermoid Larynx Carcinoma Cell Line (HEP-2). This study has demonstrated characterization of melanin from basidiomycetes mushroom fungus, Schizophyllum commune and its applications.

  16. Flavonoids and Melanins: A Common Strategy across Two Kingdoms

    OpenAIRE

    Carletti, Giorgia; Nervo, Giuseppe; Cattivelli, Luigi

    2014-01-01

    Ultraviolet (UV) radiations alter a number of metabolic functions in vivant. They produce damages to lipids, nucleic acids and proteins, generating reactive oxygen species such as singlet oxygen (O2), hydroxyl radical (HO) and superoxide anion (O2 -). Plants and animals, after their water emersion, have developed biochemical mechanisms to protect themselves from that environmental threat through a common strategy. Melanins in animals and flavonoids in plants are antioxidant pigments acting as...

  17. Oral pigmentation: A review.

    Science.gov (United States)

    Sreeja, C; Ramakrishnan, K; Vijayalakshmi, D; Devi, M; Aesha, I; Vijayabanu, B

    2015-08-01

    Pigmentations are commonly found in the mouth. They represent in various clinical patterns that can range from just physiologic changes to oral manifestations of systemic diseases and malignancies. Color changes in the oral mucosa can be attributed to the deposition of either endogenous or exogenous pigments as a result of various mucosal diseases. The various pigmentations can be in the form of blue/purple vascular lesions, brown melanotic lesions, brown heme-associated lesions, gray/black pigmentations.

  18. Primary description of surface water phytoplankton pigment patterns in the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Naik, R.K.; Anil, A.C.; Narale, D.D.; Chitari, R.R.; Kulkarni, V.V.

    . Biogeochemical controls and feedbacks on ocean primary production. Science 281, 200-206. Gibb, S.W., Barlow, R.G., Cummings, D.G., Rees, N.W., Trees, C.C., Holligan, P., Suggett, D., 2000. Surface phytoplankton pigment distributions in the Atlantic Ocean...

  19. Phytoplankton and pigment patterns across frontal zones in the Atlantic sector of the Southern Ocean

    NARCIS (Netherlands)

    van Leeuwe, Maria A.; Kattner, Gerhard; van Oijen, Tim; de Jong, Jeroen T. M.; de Baar, Hein J.W.

    2015-01-01

    Phytoplankton distribution and concentrations of macronutrients and iron were studied in the Polar Frontal Zone (PFZ) and the eastern Weddell Gyre of the Southern Ocean, during austral autumn. HPLC analysis of algal pigments was combined with microscopy observations to assess algal distribution. Pat

  20. Melanin, a promising radioprotector: Mechanisms of actions in a mice model

    Energy Technology Data Exchange (ETDEWEB)

    Kunwar, A., E-mail: amitbio@rediffmail.com [Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Adhikary, B. [Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Jayakumar, S. [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Barik, A. [Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Chattopadhyay, S. [Bio-Organic Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Raghukumar, S. [Myko Tech Private Limited, Dona Paula, Goa‐403004 (India); Priyadarsini, K.I., E-mail: kindira@barc.gov.in [Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

    2012-10-15

    The radioprotective effect of extracellular melanin, a naturally occurring pigment, isolated from the fungus Gliocephalotrichum simplex was examined in BALB/C mice, and the probable mechanism of action was established. At an effective dose of 50 mg/kg body weight, melanin exhibited both prophylactic and mitigative activities, increasing the 30-day survival of mice by 100% and 60%, respectively, after exposure to radiation (7 Gy, whole body irradiation (WBI)). The protective activity of melanin was primarily due to inhibition of radiation-induced hematopoietic damages as evidenced by improvement in spleen parameters such as index, total cellularity, endogenous colony forming units, and maintenance of circulatory white blood cells and platelet counts. Melanin also reversed the radiation-induced decrease in ERK phosphorylation in splenic tissue, which may be the key feature in its radioprotective action. Additionally, our results indicated that the sustained activation of AKT, JNK and P38 proteins in splenic tissue of melanin pre-treated group may also play a secondary role. This was also supported by the fact that melanin could prevent apoptosis in splenic tissue by decreasing BAX/Bcl-XL ratio, and increasing the expressions of the proliferation markers (PCNA and Cyclin D1), compared to the radiation control group. Melanin also reduced the oxidative stress in hepatic tissue and abrogated immune imbalance by reducing the production of pro-inflammatory cytokines (IL6 and TNFα). In conclusion, our results confirmed that fungal melanin is a very effective radioprotector against WBI and the probable mechanisms of radioprotection are due to modulation in pro-survival (ERK) signaling, prevention of oxidative stress and immunomodulation. -- Highlights: ► Melanin showed promising radioprotection under pre and post irradiation condition. ► Melanin protects the hematopoietic system from radiation induced damage. ► Melanin modulates pro-survival pathways, immune system

  1. Contrasting patterns of phytoplankton pigments and chemotaxonomic groups along 30°S in the subtropical South Atlantic Ocean

    Science.gov (United States)

    Araujo, Milton Luiz Vieira; Mendes, Carlos Rafael Borges; Tavano, Virginia Maria; Garcia, Carlos Alberto Eiras; Baringer, Molly O'Neil

    2017-02-01

    This work describes the spatial distribution of pigments and main taxonomic groups of phytoplankton in the biogeochemical provinces of the subtropical South Atlantic Ocean, along 30°S latitude. Seawater samples (surface to 200 m depth) were collected along 120 oceanographic stations occupied in the early austral spring of 2011, during a CLIVAR Repeat Hydrography cruise. The pigments were identified and quantified by high performance liquid chromatography (HPLC), and CHEMTAX software was used to determine the relative contributions of the main taxonomic groups to total chlorophyll a (phytoplankton biomass index). Sampling stations were grouped into three provinces: Africa, Gyre, and Brazil, corresponding to the eastern, central, and western sectors of the transect, respectively. Our results showed that both vertical and horizontal distribution patterns of pigments and taxonomic groups were mainly determined by the availability of light and/or nutrients. Photosynthetic carotenoids (PSCs), associated with small flagellates (mainly haptophytes), dominated the light-limited and nutrient-enhanced deep chlorophyll maximum (DCM) layers of both the Brazil and Gyre provinces, as well as the upwelling influenced surface waters of the Africa province. The latter showed the highest chlorophyll a values ​​(>1 mg m-3) and abundance of dinoflagellates in the coastal region. Photoprotective carotenoids (PPCs) were predominant in the nutrient-poor and well-lit surface layers of the Brazil and Gyre provinces, associated with a low content of chlorophyll a ( 0.1 mg m-3) and dominance of prokaryotes (Synechoccocus and Prochloroccocus). This study demonstrates that pigment analysis can provide a useful approach to better understand the distribution of phytoplankton communities along physical-chemical gradients in a still undersampled region of the South Atlantic Ocean.

  2. Patterns in Abundance, Cell Size and Pigment Content of Aerobic Anoxygenic Phototrophic Bacteria along Environmental Gradients in Northern Lakes

    Science.gov (United States)

    Fauteux, Lisa; Cottrell, Matthew T.; Kirchman, David L.; Borrego, Carles M.; Garcia-Chaves, Maria Carolina; del Giorgio, Paul A.

    2015-01-01

    There is now evidence that aerobic anoxygenic phototrophic (AAP) bacteria are widespread across aquatic systems, yet the factors that determine their abundance and activity are still not well understood, particularly in freshwaters. Here we describe the patterns in AAP abundance, cell size and pigment content across wide environmental gradients in 43 temperate and boreal lakes of Québec. AAP bacterial abundance varied from 1.51 to 5.49 x 105 cells mL-1, representing ecological advantage in highly colored, low-chlorophyll lakes, where DOC pool is chemically and structurally more complex. PMID:25927833

  3. Cardiocondyla pirata sp. n. – a new Philippine ant with enigmatic pigmentation pattern (Hymenoptera, Formicidae

    Directory of Open Access Journals (Sweden)

    Bernhard Seifert

    2013-05-01

    Full Text Available A new species of the ant genus Cardiocondyla Emery, 1869 – Cardiocondyla pirata sp. n. – is described from the Philippines. The species belongs to an Indo-Malayan group of six species that is characterized by workersa strongly bilobate postpetiolar sternite and a thickset mesosoma with strongly convex dorsal profile as well as wingless, ergatoid males with sickle-shaped mandibles. The female castes show a pigmentation pattern not known from any ant worldwide. Ifany adaptive value, a possible function of this structure is supposed to be visual dissolution of body shape in order to irritate predators.

  4. Modulation of yellow expression contributes to thermal plasticity of female abdominal pigmentation in Drosophila melanogaster

    Science.gov (United States)

    Gibert, Jean-Michel; Mouchel-Vielh, Emmanuèle; Peronnet, Frédérique

    2017-01-01

    Phenotypic plasticity describes the ability of a given genotype to produce distinct phenotypes in different environments. We use the temperature sensitivity of abdominal pigmentation in Drosophila melanogaster females as a model to analyse the effect of the environment on development. We reported previously that thermal plasticity of abdominal pigmentation in females involves the pigmentation gene tan (t). However, the expression of the pigmentation gene yellow (y) was also modulated by temperature in the abdominal epidermis of pharate females. We investigate here the contribution of y to female abdominal pigmentation plasticity. First, we show that y is required for the production of black Dopamine-melanin. Then, using in situ hybridization, we show that the expression of y is strongly modulated by temperature in the abdominal epidermis of pharate females but not in bristles. Interestingly, these two expression patterns are known to be controlled by distinct enhancers. However, the activity of the y-wing-body epidermal enhancer only partially mediates the effect of temperature suggesting that additional regulatory sequences are involved. In addition, we show that y and t co-expression is needed to induce strong black pigmentation indicating that y contributes to female abdominal pigmentation plasticity. PMID:28230190

  5. Photoacoustic measurement of epidermal melanin

    Science.gov (United States)

    Viator, John A.; Svaasand, Lars O.; Aguilar, Guillermo; Choi, Bernard; Nelson, J. Stuart

    2003-06-01

    Most dermatologic laser procedures must consider epidermal melanin, as it is a broadband optical absorber which affects subsurface fluence, effectively limiting the amount of light reaching the dermis and targeted chromophores. An accurate method for quantifying epidermal melanin content would aid clinicians in determining proper light dosage for therapeutic laser procedures. While epidermal melanin content has been quantified non-invasively using optical methods, there is currently no way to determine the melanin distribution in the epidermis. We have developed a photoacoustic probe that uses a Q-switched, frequency doubled Nd:YAG laser operating at 532nm to generate acoustic pulses in skin in vivo. The probe contained a piezoelectric element that detected photoacoustic waves which were then analyzed for epidermal melanin content, using a photoacoustic melanin index (PAMI). We tested 15 human subjects with skin types I--VI using the photoacoustic probe. We also present photoacoustic data for a human subject with vitiligo. Photoacoustic measurement showed melanin in the vitiligo subject was almost completely absent.

  6. Manassantin A and B from Saururus chinensis inhibiting cellular melanin production.

    Science.gov (United States)

    Seo, Chang-Seob; Lee, Won-Hee; Chung, Hee-Wook; Chang, Eun Ju; Lee, Seung Ho; Jahng, Yurngdong; Hwang, Bang Yeon; Son, Jong-Keun; Han, Sang-Bae; Kim, Youngsoo

    2009-11-01

    Hyperpigmentation disorders such as freckles and senile lentigines in the skin are associated with abnormal accumulation of melanin pigments. In this study, two lignan constituents were isolated from Saururus chinensis Baill (Saururaceae) as inhibitors of cellular melanin production by bioassay-guided fractionations. The active constituents were manassantin A and B that dose-dependently inhibited melanin production in alpha-melanocyte stimulating hormone (alpha-MSH)-activated melanoma B16 cells with IC(50) values of 13 nm and 8 nm, respectively. Arbutin as a positive control exhibited an IC(50) value of 96 microm on alpha-MSH-induced melanin production. Further, manassantin A inhibited forskolin- or 3-isobutyl-1-methylxanthine (IBMX)-induced melanin production with IC(50) values of 14 nm or 12 nm, respectively. Manassantin A decreased cellular amounts of IBMX-inducible tyrosinase protein but could not affect the catalytic activity of cell-free tyrosinase, a key enzyme in the biosynthetic pathway of melanin pigments. Finally, this study could provide a pharmacological potential of S. chinensis in hyperpigmentation disorders.

  7. BmPAH catalyzes the initial melanin biosynthetic step in Bombyx mori.

    Directory of Open Access Journals (Sweden)

    Ping Chen

    Full Text Available Pigmentation during insect development is a primal adaptive requirement. In the silkworm, melanin is the primary component of larval pigments. The rate limiting substrate in melanin synthesis is tyrosine, which is converted from phenylalanine by the rate-limiting enzyme phenylalanine hydroxylase (PAH. While the role of tyrosine, derived from phenylalanine, in the synthesis of fiber proteins has long been known, the role of PAH in melanin synthesis is still unknown in silkworm. To define the importance of PAH, we cloned the cDNA sequence of BmPAH and expressed its complete coding sequence using the Bac-to-Bac baculovirus expression system. Purified recombinant protein had high PAH activity, some tryptophan hydroxylase activity, but no tyrosine hydroxylase activity, which are typical properties of PAH in invertebrates. Because melanin synthesis is most robust during the embryonic stage and larval integument recoloring stage, we injected BmPAH dsRNA into silkworm eggs and observed that decreasing BmPAH mRNA reduced neonatal larval tyrosine and caused insect coloration to fail. In vitro cultures and injection of 4(th instar larval integuments with PAH inhibitor revealed that PAH activity was essential for larval marking coloration. These data show that BmPAH is necessary for melanin synthesis and we propose that conversion of phenylalanine to tyrosine by PAH is the first step in the melanin biosynthetic pathway in the silkworm.

  8. Two-stage Turing model for generating pigment patterns on the leopard and the jaguar

    Science.gov (United States)

    Liu, R. T.; Liaw, S. S.; Maini, P. K.

    2006-07-01

    Based on the results of phylogenetic analysis, which showed that flecks are the primitive pattern of the felid family and all other patterns including rosettes and blotches develop from it, we construct a Turing reaction-diffusion model which generates spot patterns initially. Starting from this spotted pattern, we successfully generate patterns of adult leopards and jaguars by tuning parameters of the model in the subsequent phase of patterning.

  9. Pigmented Pheochromocytoma: an Unusual Variant of a Common Tumor.

    Science.gov (United States)

    Kakkar, Aanchal; Kaur, Kavneet; Kumar, Tarun; Cherian, Libin Babu; Kaushal, Rohit; Sharma, Mehar Chand; Dhar, Anita; Seth, Amlesh; Jain, Deepali

    2016-03-01

    Pheochromocytoma is a neuroendocrine tumor arising from the adrenal medulla. A number of variants of pheochromocytoma are known; however, pigmented pheochromocytoma is extremely rare, with only few cases reported in literature. We report the cases of two patients with pigmented pheochromocytoma. Case 1 was a 28-year-old female who presented with complaints of breathlessness, palpitations, and anxiety for 5 years, which had worsened over the last 8 months. Computed tomography (CT) abdomen showed a right suprarenal mass. Case 2 was that of an 18-year-old girl who presented with similar complaints and was diagnosed with hypertension. CT abdomen showed bilateral adrenal masses. Urinary vanillyl mandelic acid was raised in both patients. Sections examined from all three tumors showed cells arranged in Zellballen pattern, separated by thin fibrovascular septae. Tumor cells showed moderate to marked nuclear pleomorphism in case 1. Mitoses were, however, not seen. There was no evidence of capsular or vascular invasion. Many of the tumor cells showed intracytoplasmic black pigment, which was positive for Fontana-Masson and was bleach-labile, confirming it as melanin. Hemosiderin deposition was also identified. Large areas of hemorrhagic necrosis were seen in case 1. Tumor cells were immunopositive for chromogranin and synaptophysin, while they were negative for HMB-45. Electron microscopy was performed. A final diagnosis of pigmented pheochromocytoma was rendered in both cases. Pigmented pheochromocytoma is a very rare tumor, which needs to be differentiated from other pigmented tumors like malignant melanoma of adrenal gland and pigmented adrenal adenoma. Histochemistry and immunohistochemistry help in making this distinction.

  10. Patterns in Abundance, Cell Size and Pigment Content of Aerobic Anoxygenic Phototrophic Bacteria along Environmental Gradients in Northern Lakes.

    Directory of Open Access Journals (Sweden)

    Lisa Fauteux

    Full Text Available There is now evidence that aerobic anoxygenic phototrophic (AAP bacteria are widespread across aquatic systems, yet the factors that determine their abundance and activity are still not well understood, particularly in freshwaters. Here we describe the patterns in AAP abundance, cell size and pigment content across wide environmental gradients in 43 temperate and boreal lakes of Québec. AAP bacterial abundance varied from 1.51 to 5.49 x 105 cells mL-1, representing <1 to 37% of total bacterial abundance. AAP bacteria were present year-round, including the ice-cover period, but their abundance relative to total bacterial abundance was significantly lower in winter than in summer (2.6% and 7.7%, respectively. AAP bacterial cells were on average two-fold larger than the average bacterial cell size, thus AAP cells made a greater relative contribution to biomass than to abundance. Bacteriochlorophyll a (BChla concentration varied widely across lakes, and was not related to AAP bacterial abundance, suggesting a large intrinsic variability in the cellular pigment content. Absolute and relative AAP bacterial abundance increased with dissolved organic carbon (DOC, whereas cell-specific BChla content was negatively related to chlorophyll a (Chla. As a result, both the contribution of AAP bacteria to total prokaryotic abundance, and the cell-specific BChla pigment content were positively correlated with the DOC:Chla ratio, both peaking in highly colored, low-chlorophyll lakes. Our results suggest that photoheterotrophy might represent a significant ecological advantage in highly colored, low-chlorophyll lakes, where DOC pool is chemically and structurally more complex.

  11. Patterns in Abundance, Cell Size and Pigment Content of Aerobic Anoxygenic Phototrophic Bacteria along Environmental Gradients in Northern Lakes.

    Science.gov (United States)

    Fauteux, Lisa; Cottrell, Matthew T; Kirchman, David L; Borrego, Carles M; Garcia-Chaves, Maria Carolina; Del Giorgio, Paul A

    2015-01-01

    There is now evidence that aerobic anoxygenic phototrophic (AAP) bacteria are widespread across aquatic systems, yet the factors that determine their abundance and activity are still not well understood, particularly in freshwaters. Here we describe the patterns in AAP abundance, cell size and pigment content across wide environmental gradients in 43 temperate and boreal lakes of Québec. AAP bacterial abundance varied from 1.51 to 5.49 x 105 cells mL-1, representing bacterial abundance. AAP bacteria were present year-round, including the ice-cover period, but their abundance relative to total bacterial abundance was significantly lower in winter than in summer (2.6% and 7.7%, respectively). AAP bacterial cells were on average two-fold larger than the average bacterial cell size, thus AAP cells made a greater relative contribution to biomass than to abundance. Bacteriochlorophyll a (BChla) concentration varied widely across lakes, and was not related to AAP bacterial abundance, suggesting a large intrinsic variability in the cellular pigment content. Absolute and relative AAP bacterial abundance increased with dissolved organic carbon (DOC), whereas cell-specific BChla content was negatively related to chlorophyll a (Chla). As a result, both the contribution of AAP bacteria to total prokaryotic abundance, and the cell-specific BChla pigment content were positively correlated with the DOC:Chla ratio, both peaking in highly colored, low-chlorophyll lakes. Our results suggest that photoheterotrophy might represent a significant ecological advantage in highly colored, low-chlorophyll lakes, where DOC pool is chemically and structurally more complex.

  12. Transcriptome analysis of the painted lady butterfly, Vanessa cardui during wing color pattern development.

    Science.gov (United States)

    Connahs, Heidi; Rhen, Turk; Simmons, Rebecca B

    2016-03-31

    Butterfly wing color patterns are an important model system for understanding the evolution and development of morphological diversity and animal pigmentation. Wing color patterns develop from a complex network composed of highly conserved patterning genes and pigmentation pathways. Patterning genes are involved in regulating pigment synthesis however the temporal expression dynamics of these interacting networks is poorly understood. Here, we employ next generation sequencing to examine expression patterns of the gene network underlying wing development in the nymphalid butterfly, Vanessa cardui. We identified 9, 376 differentially expressed transcripts during wing color pattern development, including genes involved in patterning, pigmentation and gene regulation. Differential expression of these genes was highest at the pre-ommochrome stage compared to early pupal and late melanin stages. Overall, an increasing number of genes were down-regulated during the progression of wing development. We observed dynamic expression patterns of a large number of pigment genes from the ommochrome, melanin and also pteridine pathways, including contrasting patterns of expression for paralogs of the yellow gene family. Surprisingly, many patterning genes previously associated with butterfly pattern elements were not significantly up-regulated at any time during pupation, although many other transcription factors were differentially expressed. Several genes involved in Notch signaling were significantly up-regulated during the pre-ommochrome stage including slow border cells, bunched and pebbles; the function of these genes in the development of butterfly wings is currently unknown. Many genes involved in ecdysone signaling were also significantly up-regulated during early pupal and late melanin stages and exhibited opposing patterns of expression relative to the ecdysone receptor. Finally, a comparison across four butterfly transcriptomes revealed 28 transcripts common to all

  13. An Ultra-Violet Tolerant Wild-Type Strain of Melanin-Producing Bacillus thuringiensis

    Science.gov (United States)

    Sansinenea, Estibaliz; Salazar, Francisco; Ramirez, Melanie; Ortiz, Aurelio

    2015-01-01

    Background: Bacillus thuringiensis is the most successful biological control agent used in agriculture, forestry and mosquito control. However, the insecticidal activity of the B. thuringiensis formulation is not very stable and rapidly loses its biological activity under field conditions, due to the ultraviolet radiation in sunlight. Melanin is known to absorb radiation therefore photo protection of B. thuringiensis based on melanin has been extensively studied. Objectives: The aim of this study was to find a wild type strain of naturally melanin-producing B. thuringiensis to avoid any mutation or manipulation that can affect the Cry protein content. Materials and Methods: Bacillus thuringiensis strains were isolated from soils of different States of Mexico and pigment extraction was followed by lowering the pH to 2 using 1N HCl. Pigment was characterized by some chemical tests based on its solubility, bleaching by H2O2 and flocculation with FeCl3, and using an Infrared (IR) spectrum. Ultraviolet (UV) irradiation experiment was performed to probe the melanin efficacy. Results: ELI52 strain of B. thuringiensis was confirmed to naturally produce melanin. The Cry protein analysis suggested that ELI52 is probably a B. thuringiensis subsp. israelensis strain with toxic activity against the Diptera order of insects. Ultra Violet protection efficacy of melanin was probed counting total viable colonies after UV radiation and comparing the results with the non-producing melanin strain L-DOPA (L-3, 4-dihydroxyphenylalanine) was also detected in the culture. ELI52 strain showed an antagonistic effect over some common bacteria from the environment. Conclusions: ELI52 wild-type strain of B. thuringiensis is a good bio-insecticide that produces melanin with UV-resistance that is probably toxic against the Diptera order of insects and can inhibit the growth of other environmental bacteria. PMID:26421136

  14. High refractive index of melanin in shiny occipital feathers of a bird of paradise

    NARCIS (Netherlands)

    Stavenga, Doekele G.; Leertouwer, Heinrich; Osorio, Daniel C.; Wilts, Bodo D.

    2015-01-01

    Male Lawes's Parotia, a bird of paradise, use the highly directional reflection of the structurally colored, brilliant-silvery occipital feathers in their courtship display. As in other birds, the structural coloration is produced by ordered melanin pigmentation. The barbules of the Parotia's occipi

  15. Combined effects of Cu and UVR on survival and melanin synthesis in Chironomus riparius larvae

    NARCIS (Netherlands)

    de Baat, M.L.; van Gemert, M.; Verweij, R.A.; Loayza Muro, R.A.; Kraak, M.H.S.

    2012-01-01

    The tropical Andes encompass vast areas with altitudes above 4000 m, where the combination of high UV radiation and metal pollution creates environments that challenge the survival and persistence of aquatic life. Since the pigment melanin counteracts the negative effects of UVR, and has the additio

  16. High refractive index of melanin in shiny occipital feathers of a bird of paradise

    NARCIS (Netherlands)

    Stavenga, Doekele G.; Leertouwer, Heinrich; Osorio, Daniel C.; Wilts, Bodo D.

    Male Lawes's Parotia, a bird of paradise, use the highly directional reflection of the structurally colored, brilliant-silvery occipital feathers in their courtship display. As in other birds, the structural coloration is produced by ordered melanin pigmentation. The barbules of the Parotia's

  17. Combined effects of Cu and UVR on survival and melanin synthesis in Chironomus riparius larvae

    NARCIS (Netherlands)

    de Baat, M.L.; van Gemert, M.; Verweij, R.A.; Loayza Muro, R.A.; Kraak, M.H.S.

    2012-01-01

    The tropical Andes encompass vast areas with altitudes above 4000 m, where the combination of high UV radiation and metal pollution creates environments that challenge the survival and persistence of aquatic life. Since the pigment melanin counteracts the negative effects of UVR, and has the

  18. Brightness of melanin-based plumage coloration is a cue to oxidative stress in Himalayan Black Bulbuls (Hypsipete leucocephalus nigerrimus)

    Institute of Scientific and Technical Information of China (English)

    Hsin?Yi Hung; Shou?Hsien Li

    2015-01-01

    Background: Melanin?based coloration is often found to be associated with variations in physiological and behavio?ral traits that are essential in avian communication.However,the function of melanin?based traits to their bearers has been investigated less than that of carotenoid?based ones.It is commonly believed that expression of melanin?based pigmentation is genetically controlled.However,whether it could be modulated by physical condition has remained controversial.In this study,we demonstrate that the level of melanin?based plumage pigmentation could be nega?tively correlated with an individual’s oxidative stress level.Methods: In this study,we used two groups of Black Bulbuls(Hypsipetes leucocephalus nigerrimus) obtained from a pet?shop in 2010 and 2011 to examine the correlation between the melanin?based plumage coloration and the ratio of lymphocytes to heterocytes,which is an indicator of the oxidative stress experienced by an individual.Results: We found a negative correlation between oxidative stress levels and expression of melanin?based pigmen?tation on the breast and scapular feathers,but the correlation only appeared in the 2011 group,individuals of which had higher oxidative stress level and brighter plumage(i.e.more melanins) than those of the 2010 group.Conclusions: Our data suggest that melanin?based plumage could reflect an individual’s physical condition in certain situations.Therefore,melanin?based plumage coloration could have a function in Himalayan Black Bulbuls’ communication.

  19. In vivo isolation of the effects of melanin from underlying hemodynamics across skin types using spatial frequency domain spectroscopy

    Science.gov (United States)

    Saager, Rolf B.; Sharif, Ata; Kelly, Kristen M.; Durkin, Anthony J.

    2016-05-01

    Skin is a highly structured tissue, raising concerns as to whether skin pigmentation due to epidermal melanin may confound accurate measurements of underlying hemodynamics. Using both venous and arterial cuff occlusions as a means of inducing differential hemodynamic perturbations, we present analyses of spectra limited to the visible or near-infrared regime, in addition to a layered model approach. The influence of melanin, spanning Fitzpatrick skin types I to V, on underlying estimations of hemodynamics in skin as interpreted by these spectral regions are assessed. The layered model provides minimal cross-talk between melanin and hemodynamics and enables removal of problematic correlations between measured tissue oxygenation estimates and skin phototype.

  20. Pigment cell movement is not required for generation of Turing patterns in zebrafish skin

    Science.gov (United States)

    Bullara, D.; de Decker, Y.

    2015-05-01

    The zebrafish is a model organism for pattern formation in vertebrates. Understanding what drives the formation of its coloured skin motifs could reveal pivotal to comprehend the mechanisms behind morphogenesis. The motifs look and behave like reaction-diffusion Turing patterns, but the nature of the underlying physico-chemical processes is very different, and the origin of the patterns is still unclear. Here we propose a minimal model for such pattern formation based on a regulatory mechanism deduced from experimental observations. This model is able to produce patterns with intrinsic wavelength, closely resembling the experimental ones. We mathematically prove that their origin is a Turing bifurcation occurring despite the absence of cell motion, through an effect that we call differential growth. This mechanism is qualitatively different from the reaction-diffusion originally proposed by Turing, although they both generate the short-range activation and the long-range inhibition required to form Turing patterns.

  1. Understanding visual search patterns of dermatologists assessing pigmented skin lesions before and after online training.

    Science.gov (United States)

    Krupinski, Elizabeth A; Chao, Joseph; Hofmann-Wellenhof, Rainer; Morrison, Lynne; Curiel-Lewandrowski, Clara

    2014-12-01

    The goal of this investigation was to explore the feasibility of characterizing the visual search characteristics of dermatologists evaluating images corresponding to single pigmented skin lesions (PSLs) (close-ups and dermoscopy) as a venue to improve training programs for dermoscopy. Two Board-certified dermatologists and two dermatology residents participated in a phased study. In phase I, they viewed a series of 20 PSL cases ranging from benign nevi to melanoma. The close-up and dermoscopy images of the PSL were evaluated sequentially and rated individually as benign or malignant, while eye position was recorded. Subsequently, the participating subjects completed an online dermoscopy training module that included a pre- and post-test assessing their dermoscopy skills (phase 2). Three months later, the subjects repeated their assessment on the 20 PSLs presented during phase I of the study. Significant differences in viewing time and eye-position parameters were observed as a function of level of expertise. Dermatologists overall have more efficient search than residents generating fewer fixations with shorter dwells. Fixations and dwells associated with decisions changing from benign to malignant or vice versa from photo to dermatoscopic viewing were longer than any other decision, indicating increased visual processing for those decisions. These differences in visual search may have implications for developing tools to teach dermatologists and residents about how to better utilize dermoscopy in clinical practice.

  2. Physical factors affecting chloroquine binding to melanin.

    Science.gov (United States)

    Schroeder, R L; Pendleton, P; Gerber, J P

    2015-10-01

    Chloroquine is an antimalarial drug but is also prescribed for conditions such as rheumatoid arthritis. Long-term users risk toxic side effects, including retinopathy, thought to be caused by chloroquine accumulation on ocular melanin. Although the binding potential of chloroquine to melanin has been investigated previously, our study is the first to demonstrate clear links between chloroquine adsorption by melanin and system factors including temperature, pH, melanin type, and particle size. In the current work, two Sepia melanins were compared with bovine eye as a representative mammalian melanin. Increasing the surface anionic character due to a pH change from 4.7 to 7.4 increased each melanin's affinity for chloroquine. Although the chloroquine isotherms exhibited an apparently strong interaction with each melanin, isosteric heat analysis indicated a competitive interaction. Buffer solution cations competed effectively at low surface coverage; chloroquine adsorption occurs via buffer cation displacement and is promoted by temperature-influenced secondary structure swelling.

  3. Pigment pattern in jaguar/obelix zebrafish is caused by a Kir7.1 mutation: implications for the regulation of melanosome movement.

    Directory of Open Access Journals (Sweden)

    Motoko Iwashita

    2006-11-01

    Full Text Available Many animals have a variety of pigment patterns, even within a species, and these patterns may be one of the driving forces of speciation. Recent molecular genetic studies on zebrafish have revealed that interaction among pigment cells plays a key role in pattern formation, but the mechanism of pattern formation is unclear. The zebrafish jaguar/obelix mutant has broader stripes than wild-type fish. In this mutant, the development of pigment cells is normal but their distribution is altered, making these fish ideal for studying the process of pigment pattern formation. Here, we utilized a positional cloning method to determine that the inwardly rectifying potassium channel 7.1 (Kir7.1 gene is responsible for pigment cell distribution among jaguar/obelix mutant fish. Furthermore, in jaguar/obelix mutant alleles, we identified amino acid changes in the conserved region of Kir7.1, each of which affected K(+ channel activity as demonstrated by patch-clamp experiments. Injection of a bacterial artificial chromosome containing the wild-type Kir7.1 genomic sequence rescued the jaguar/obelix phenotype. From these results, we conclude that mutations in Kir7.1 are responsible for jaguar/obelix. We also determined that the ion channel function defect of melanophores expressing mutant Kir7.1 altered the cellular response to external signals. We discovered that mutant melanophores cannot respond correctly to the melanosome dispersion signal derived from the sympathetic neuron and that melanosome aggregation is constitutively activated. In zebrafish and medaka, it is well known that melanosome aggregation and subsequent melanophore death increase when fish are kept under constant light conditions. These observations indicate that melanophores of jaguar/obelix mutant fish have a defect in the signaling pathway downstream of the alpha2-adrenoceptor. Taken together, our results suggest that the cellular defect of the Kir7.1 mutation is directly responsible for

  4. Pigment pattern in jaguar/obelix zebrafish is caused by a Kir7.1 mutation: implications for the regulation of melanosome movement.

    Science.gov (United States)

    Iwashita, Motoko; Watanabe, Masakatsu; Ishii, Masaru; Chen, Tim; Johnson, Stephen L; Kurachi, Yoshihisa; Okada, Norihiro; Kondo, Shigeru

    2006-11-24

    Many animals have a variety of pigment patterns, even within a species, and these patterns may be one of the driving forces of speciation. Recent molecular genetic studies on zebrafish have revealed that interaction among pigment cells plays a key role in pattern formation, but the mechanism of pattern formation is unclear. The zebrafish jaguar/obelix mutant has broader stripes than wild-type fish. In this mutant, the development of pigment cells is normal but their distribution is altered, making these fish ideal for studying the process of pigment pattern formation. Here, we utilized a positional cloning method to determine that the inwardly rectifying potassium channel 7.1 (Kir7.1) gene is responsible for pigment cell distribution among jaguar/obelix mutant fish. Furthermore, in jaguar/obelix mutant alleles, we identified amino acid changes in the conserved region of Kir7.1, each of which affected K(+) channel activity as demonstrated by patch-clamp experiments. Injection of a bacterial artificial chromosome containing the wild-type Kir7.1 genomic sequence rescued the jaguar/obelix phenotype. From these results, we conclude that mutations in Kir7.1 are responsible for jaguar/obelix. We also determined that the ion channel function defect of melanophores expressing mutant Kir7.1 altered the cellular response to external signals. We discovered that mutant melanophores cannot respond correctly to the melanosome dispersion signal derived from the sympathetic neuron and that melanosome aggregation is constitutively activated. In zebrafish and medaka, it is well known that melanosome aggregation and subsequent melanophore death increase when fish are kept under constant light conditions. These observations indicate that melanophores of jaguar/obelix mutant fish have a defect in the signaling pathway downstream of the alpha2-adrenoceptor. Taken together, our results suggest that the cellular defect of the Kir7.1 mutation is directly responsible for the pattern change

  5. A novel melanin inhibitor: hydroperoxy traxastane-type triterpene from flowers of Arnica montana.

    Science.gov (United States)

    Maeda, Kazuhisa; Naitou, Tomoko; Umishio, Kenichi; Fukuhara, Tadao; Motoyama, Akira

    2007-05-01

    We isolated a novel inhibitor of melanin biosynthesis from the flowers of Arnica montana L. (Compositae), and identified it as a traxastane-type triterpene (3beta,16beta-dihydroxy-21alpha-hydroperoxy-20(30)-taraxastene) [1] by means of 1D or 2D-NMR and liquid chromatography/high-resolution mass spectrometry (LC-HR-MS). Compound [1] at the concentration of 0.53 muM completely inhibited melanin accumulation in cultured B16 melanoma cells. It is one of the most potent among known plant inhibitors of melanin biosynthesis in cultured cells, being 50 times more potent than 4-methoxyphenol, which is used as an anti-pigmentation agent. Its mechanism of action is considered to involve inhibition of transcriptional factor MITF-M (melanocyte-type isoform of microphthalmia-associated transcription factor), which would lead to a decrease of tyrosinase and related genes. We confirmed that compound [1] decreased the protein levels of tyrosinase and its related proteins in B16 melanoma cells. Further study revealed that a similar hydroperoxy triterpene also suppressed the melanin pigment accumulation of B16 melanoma cells. These results indicate that the hydroperoxy group may play an important role in the suppression of the melanin accumulation by compound [1].

  6. Melanocyte biology and function with reference to oral melanin hyperpigmentation in HIV-seropositive subjects.

    Science.gov (United States)

    Feller, Liviu; Chandran, Rakesh; Kramer, Beverley; Khammissa, Razia A G; Altini, Mario; Lemmer, Johan

    2014-09-01

    The color of normal skin and of oral mucosa is not determined by the number of melanocytes in the epithelium but rather by their melanogenic activity. Pigmented biopolymers or melanins are synthesized in melanosomes. Tyrosinase is the critical enzyme in the biosynthesis of both brown/black eumelanin and yellow/red pheomelanin. The number of the melanosomes within the melanocytes, the type of melanin within the melanosomes, and the efficacy of the transfer of melanosomes from the melanocytes to the neighboring keratinocytes all play an important role in tissue pigmentation. Melanin production is regulated by locally produced factors including proopiomelanocortin and its derivative peptides, particularly alpha-melanocyte-stimulating hormone (α-MSH), melanocortin 1 receptor (MC1R), adrenergic and cholinergic agents, growth factors, cytokines, and nitric oxide. Both eumelanin and pheomelanin can be produced by the same melanocytes, and the proportion of the two melanin types is influenced by the degree of functional activity of the α-MSH/MC1R intracellular pathway. The cause of HIV oral melanosis is not fully understood but may be associated with HIV-induced cytokine dysregulation, with the medications commonly prescribed to HIV-seropositive persons, and with adrenocortical dysfunction, which is not uncommon in HIV-seropositive subjects with AIDS. The purpose of this article is to discuss some aspects of melanocyte biology and HIV-associated oral melanin hyperpigmentation.

  7. In vivo measurements of cutaneous melanin across spatial scales: using multiphoton microscopy and spatial frequency domain spectroscopy.

    Science.gov (United States)

    Saager, Rolf B; Balu, Mihaela; Crosignani, Viera; Sharif, Ata; Durkin, Anthony J; Kelly, Kristen M; Tromberg, Bruce J

    2015-06-01

    The combined use of nonlinear optical microscopy and broadband reflectance techniques to assess melanin concentration and distribution thickness in vivo over the full range of Fitzpatrick skin types is presented. Twelve patients were measured using multiphoton microscopy (MPM) and spatial frequency domain spectroscopy (SFDS) on both dorsal forearm and volar arm, which are generally sun-exposed and non-sun-exposed areas, respectively. Both MPM and SFDS measured melanin volume fractions between (skin type I non-sun-exposed) and 20% (skin type VI sun exposed). MPM measured epidermal (anatomical) thickness values ~30-65 μm, while SFDS measured melanin distribution thickness based on diffuse optical path length. There was a strong correlation between melanin concentration and melanin distribution (epidermal) thickness measurements obtained using the two techniques. While SFDS does not have the ability to match the spatial resolution of MPM, this study demonstrates that melanin content as quantified using SFDS is linearly correlated with epidermal melanin as measured using MPM (R² = 0.8895). SFDS melanin distribution thickness is correlated to MPM values (R² = 0.8131). These techniques can be used individually and/or in combination to advance our understanding and guide therapies for pigmentation-related conditions as well as light-based treatments across a full range of skin types.

  8. Study of Melanin Bleaching After Immunohistochemistry of Melanin-containing Tissues

    OpenAIRE

    2015-01-01

    Melanin may interfere with immunohistochemical staining. The goal of this study was to investigate the effects of trichloroisocyanuric acid (TCCA) bleaching, potassium permanganate bleaching, and potassium dichromate bleaching on melanin, tissue antigen, and 3,3′-diaminobenzidine (DAB) using melanin-containing and melanin-free tissue samples. Our results demonstrated that all 3 bleaching methods efficiently bleached melanin and partially destroyed tissue antigen. In addition, potassium perman...

  9. Melanin from the nitrogen-fixing bacterium Azotobacter chroococcum: a spectroscopic characterization.

    Directory of Open Access Journals (Sweden)

    Aulie Banerjee

    Full Text Available Melanins, the ubiquitous hetero-polymer pigments found widely dispersed among various life forms, are usually dark brown/black in colour. Although melanins have variety of biological functions, including protection against ultraviolet radiation of sunlight and are used in medicine, cosmetics, extraction of melanin from the animal and plant kingdoms is not an easy task. Using complementary physicochemical techniques (i.e. MALDI-TOF, FTIR absorption and cross-polarization magic angle spinning solid-state (13C NMR, we report here the characterization of melanins extracted from the nitrogen-fixing non-virulent bacterium Azotobacter chroococcum, a safe viable source. Moreover, considering dihydroxyindole moiety as the main constituent, an effort is made to propose the putative molecular structure of the melanin hetero-polymer extracted from the bacterium. Characterization of the melanin obtained from Azotobacter chroococcum would provide an inspiration in extending research activities on these hetero-polymers and their use as protective agent against UV radiation.

  10. Spermidine, but not spermine, is essential for pigment pattern formation in zebrafish

    Directory of Open Access Journals (Sweden)

    Hans Georg Frohnhöfer

    2016-06-01

    Full Text Available Polyamines are small poly-cations essential for all cellular life. The main polyamines present in metazoans are putrescine, spermidine and spermine. Their exact functions are still largely unclear; however, they are involved in a wide variety of processes affecting cell growth, proliferation, apoptosis and aging. Here we identify idefix, a mutation in the zebrafish gene encoding the enzyme spermidine synthase, leading to a severe reduction in spermidine levels as shown by capillary electrophoresis-mass spectrometry. We show that spermidine, but not spermine, is essential for early development, organogenesis and colour pattern formation. Whereas in other vertebrates spermidine deficiency leads to very early embryonic lethality, maternally provided spermidine synthase in zebrafish is sufficient to rescue the early developmental defects. This allows us to uncouple them from events occurring later during colour patterning. Factors involved in the cellular interactions essential for colour patterning, likely targets for spermidine, are the gap junction components Cx41.8, Cx39.4, and Kir7.1, an inwardly rectifying potassium channel, all known to be regulated by polyamines. Thus, zebrafish provide a vertebrate model to study the in vivo effects of polyamines.

  11. Spermidine, but not spermine, is essential for pigment pattern formation in zebrafish.

    Science.gov (United States)

    Frohnhöfer, Hans Georg; Geiger-Rudolph, Silke; Pattky, Martin; Meixner, Martin; Huhn, Carolin; Maischein, Hans-Martin; Geisler, Robert; Gehring, Ines; Maderspacher, Florian; Nüsslein-Volhard, Christiane; Irion, Uwe

    2016-06-15

    Polyamines are small poly-cations essential for all cellular life. The main polyamines present in metazoans are putrescine, spermidine and spermine. Their exact functions are still largely unclear; however, they are involved in a wide variety of processes affecting cell growth, proliferation, apoptosis and aging. Here we identify idefix, a mutation in the zebrafish gene encoding the enzyme spermidine synthase, leading to a severe reduction in spermidine levels as shown by capillary electrophoresis-mass spectrometry. We show that spermidine, but not spermine, is essential for early development, organogenesis and colour pattern formation. Whereas in other vertebrates spermidine deficiency leads to very early embryonic lethality, maternally provided spermidine synthase in zebrafish is sufficient to rescue the early developmental defects. This allows us to uncouple them from events occurring later during colour patterning. Factors involved in the cellular interactions essential for colour patterning, likely targets for spermidine, are the gap junction components Cx41.8, Cx39.4, and Kir7.1, an inwardly rectifying potassium channel, all known to be regulated by polyamines. Thus, zebrafish provide a vertebrate model to study the in vivo effects of polyamines.

  12. Melanin, a promising radioprotector: mechanisms of actions in a mice model.

    Science.gov (United States)

    Kunwar, A; Adhikary, B; Jayakumar, S; Barik, A; Chattopadhyay, S; Raghukumar, S; Priyadarsini, K I

    2012-10-15

    The radioprotective effect of extracellular melanin, a naturally occurring pigment, isolated from the fungus Gliocephalotrichum simplex was examined in BALB/C mice, and the probable mechanism of action was established. At an effective dose of 50mg/kg body weight, melanin exhibited both prophylactic and mitigative activities, increasing the 30-day survival of mice by 100% and 60%, respectively, after exposure to radiation (7Gy, whole body irradiation (WBI)). The protective activity of melanin was primarily due to inhibition of radiation-induced hematopoietic damages as evidenced by improvement in spleen parameters such as index, total cellularity, endogenous colony forming units, and maintenance of circulatory white blood cells and platelet counts. Melanin also reversed the radiation-induced decrease in ERK phosphorylation in splenic tissue, which may be the key feature in its radioprotective action. Additionally, our results indicated that the sustained activation of AKT, JNK and P38 proteins in splenic tissue of melanin pre-treated group may also play a secondary role. This was also supported by the fact that melanin could prevent apoptosis in splenic tissue by decreasing BAX/Bcl-XL ratio, and increasing the expressions of the proliferation markers (PCNA and Cyclin D1), compared to the radiation control group. Melanin also reduced the oxidative stress in hepatic tissue and abrogated immune imbalance by reducing the production of pro-inflammatory cytokines (IL6 and TNFα). In conclusion, our results confirmed that fungal melanin is a very effective radioprotector against WBI and the probable mechanisms of radioprotection are due to modulation in pro-survival (ERK) signaling, prevention of oxidative stress and immunomodulation.

  13. A novel role for pigment genes in the stress response in rainbow trout (Oncorhynchus mykiss)

    KAUST Repository

    Khan, Uniza Wahid

    2016-07-04

    In many vertebrate species visible melanin-based pigmentation patterns correlate with high stress- and disease-resistance, but proximate mechanisms for this trait association remain enigmatic. Here we show that a missense mutation in a classical pigmentation gene, melanocyte stimulating hormone receptor (MC1R), is strongly associated with distinct differences in steroidogenic melanocortin 2 receptor (MC2R) mRNA expression between high- (HR) and low-responsive (LR) rainbow trout (Oncorhynchus mykiss). We also show experimentally that cortisol implants increase the expression of agouti signaling protein (ASIP) mRNA in skin, likely explaining the association between HR-traits and reduced skin melanin patterning. Molecular dynamics simulations predict that melanocortin 2 receptor accessory protein (MRAP), needed for MC2R function, binds differently to the two MC1R variants. Considering that mRNA for MC2R and the MC1R variants are present in head kidney cells, we hypothesized that MC2R activity is modulated in part by different binding affinities of the MC1R variants for MRAP. Experiments in mammalian cells confirmed that trout MRAP interacts with the two trout MC1R variants and MC2R, but failed to detect regulation of MC2R signaling, possibly due to high constitutive MC1R activity.

  14. From tyrosine to melanin: Signaling pathways and factors regulating melanogenesis

    Directory of Open Access Journals (Sweden)

    Zuzanna Rzepka

    2016-06-01

    Full Text Available Melanins are natural pigments of skin, hair and eyes and can be classified into two main types: brown to black eumelanin and yellow to reddish-brown pheomelanin. Biosynthesis of melanins takes place in melanosomes, which are specialized cytoplasmic organelles of melanocytes - dendritic cells located in the basal layer of the epidermis, uveal tract of the eye, hair follicles, as well as in the inner ear, central nervous system and heart. Melanogenesis is a multistep process and begins with the conversion of amino acid L-tyrosine to DOPAquinone. The addition of cysteine or glutathione to DOPAquinone leads to the intermediates formation, followed by subsequent transformations and polymerization to the final product, pheomelanin. In the absence of thiol compounds DOPAquinone undergoes an intramolecular cyclization and oxidation to form DOPAchrome, which is then converted to 5,6-dihydroksyindole (DHI or 5,6-dihydroxyindole-2-carboxylic acid (DHICA. Eumelanin is formed by polymerization of DHI and DHICA and their quinones. Regulation of melanogenesis is achieved by physical and biochemical factors. The article presents the intracellular signaling pathways: cAMP/PKA/CREB/MITF cascade, MAP kinases cascade, PLC/DAG/PKCβ cascade and NO/cGMP/PKG cascade, which are involved in the regulation of expression and activity of the melanogenesis-related proteins by ultraviolet radiation and endogenous agents (cytokines, hormones. Activity of the key melanogenic enzyme, tyrosinase, is also affected by pH and temperature. Many pharmacologically active substances are able to inhibit or stimulate melanin biosynthesis, as evidenced by in vitro studies on cultured pigment cells.

  15. Mechanical and photo-fragmentation processes for nanonization of melanin to improve its efficacy in protecting cells from reactive oxygen species stress

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yi-Cheng [Graduate Institute of Photonics and Optoelectronics, and Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China); Chen, Sih-Min [Graduate Institute of Biophysics, National Central University, Jhongli 32001, Taiwan (China); Liu, Jhong-Han; Hsu, Hsiang-Wei [Department of Physics, National Central University, Jhongli 32001, Taiwan (China); Lin, Hoang-Yan [Graduate Institute of Photonics and Optoelectronics, and Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Chen, Szu-yuan, E-mail: sychen@ltl.iams.sinica.edu.tw [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China); Graduate Institute of Biophysics, National Central University, Jhongli 32001, Taiwan (China); Department of Physics, National Central University, Jhongli 32001, Taiwan (China)

    2015-02-14

    It has been well established ex vivo that melanin has the ability of scavenging free radicals and reactive oxygen species (ROS), besides other functions. Therefore, we propose to utilize nanonized melanin as medication against acute oxidative stress. For this purpose, we developed and characterized two techniques based on mechanical stir and photo-fragmentation using femtosecond laser pulses, respectively, for disintegration of suspended melanin powder to produce nanometer-sized and water-dispersible melanin. This resolves a major obstacle in the medical and industrial applications of melanin. The viabilities of cultured retinal pigment epithelium (RPE) cells exposed to exogenous H{sub 2}O{sub 2} stress and treated with various conditions of melanin and irradiation were compared. It was found that melanin could be nanonized very effectively with the techniques, and nanonized melanin exhibited a much stronger effect than unprocessed melanin on raising the viability of cultured RPE cells under acute ROS stress. The effect was even more prominent without simultaneous light irradiation, promising for effective in vivo application to the whole body.

  16. Quantitative photoacoustics to measure single cell melanin production and nanoparticle attachment

    Science.gov (United States)

    Bhattacharyya, Kiran; Eshein, Adam; Chandrasekhar, Anand; Viator, John A.

    2015-04-01

    Photoacoustics can be used as a label-free spectroscopic method of identifying pigmented proteins and characterizing their intracellular concentration over time in a single living cell. The authors use a microscopic laser irradiation system with a 5 ns, Q-switched laser focused onto single cells in order to collect photoacoustic responses of melanoma cells from the HS936 cell line and gold nanoparticle labeled breast cancer cells from the T47D cell line. The volume averaged intracellular concentration of melanin is found to range from 29-270 mM for single melanoma cells and the number of gold nanoparticles (AuNP) is shown to range from 850-5900 AuNPs/cell. Additionally, the melanin production response to UV-A light stimulus is measured in four melanoma cells to find a mass production rate of 5.7 pg of melanin every 15 min.

  17. GAMMA RADIATION INTERACTS WITH MELANIN TO ALTER ITS OXIDATION-REDUCTION POTENTIAL AND RESULTS IN ELECTRIC CURRENT PRODUCTION

    Energy Technology Data Exchange (ETDEWEB)

    Turick, C.; Ekechukwu, A.; Milliken, C.

    2011-05-17

    The presence of melanin pigments in organisms is implicated in radioprotection and in some cases, enhanced growth in the presence of high levels of ionizing radiation. An understanding of this phenomenon will be useful in the design of radioprotective materials. However, the protective mechanism of microbial melanin in ionizing radiation fields has not yet been elucidated. Here we demonstrate through the electrochemical techniques of chronoamperometry, chronopotentiometry and cyclic voltammetry that microbial melanin is continuously oxidized in the presence of gamma radiation. Our findings establish that ionizing radiation interacts with melanin to alter its oxidation-reduction potential. Sustained oxidation resulted in electric current production and was most pronounced in the presence of a reductant, which extended the redox cycling capacity of melanin. This work is the first to establish that gamma radiation alters the oxidation-reduction behavior of melanin, resulting in electric current production. The significance of the work is that it provides the first step in understanding the initial interactions between melanin and ionizing radiation taking place and offers some insight for production of biomimetic radioprotective materials.

  18. Real-time in vivo confocal laser scanning microscopy of melanin-containing cells: A promising diagnostic intervention.

    Science.gov (United States)

    Xiang, Wenzhong; Song, Xiuzu; Peng, Jianzhong; Xu, Aie; Bi, Zhigang

    2015-12-01

    The use of noninvasive imaging techniques to evaluate different types of skin lesions is increasing popular. In vivo confocal laser scanning microscopy (CLSM) is a new method for high resolution non-invasive imaging of intact skin in situ and in vivo. Although many studies have investigated melanin-containing cells in lesions by in vivo CLSM, few studies have systematically characterized melanin-containing cells based on their morphology, size, arrangement, density, borders, and brightness. In this study, the characteristics of melanin-containing cells were further investigated by in vivo CLSM. A total of 130 lesions, including common nevi, giant congenital pigmented nevi, vitiligo, melasma, melanoma, and chronic eczema, were imaged by in vivo CLSM. This research helps dermatologists understand the characteristics of melanin-containing cells and facilitate the clinical application of melanin-containing cells in the investigation of dermatological disease. In summary, melanin-containing cells include keratinocytes, melanocytes, macrophages, and melanocytic skin tumor cells. Our study presents the CLSM characteristics of melanin-containing cells to potentially facilitate in vivo diagnosis based on shape, size, arrangement, density, borders, and brightness.

  19. Melanin is required for the formation of the multi-cellular conidia in the endophytic fungus Pestalotiopsis microspora.

    Science.gov (United States)

    Yu, Xi; Huo, Liang; Liu, Heng; Chen, Longfei; Wang, Yu; Zhu, Xudong

    2015-10-01

    Melanin plays an important role in regulating various biological processes in many fungi. However, its biological role in conidiation remains largely elusive. We report here that conidia production, morphogenesis, integrity, germination and their viability in Pestalotiopsis microspora require the polyketide-derived melanin. A polyketide synthase gene, pks1, was identified and demonstrated responsible for melanin biosynthesis in this fungus. A targeted deletion mutant strain Δpks1 displayed a defect in pigmentation of conidia and had an albino colonial phenotype. Interestingly, Δpks1 produced approximately 6-fold as many conidia as the wild type did, suggesting a negative modulation of melanin on conidia production in this fungus. Moreover, the conidia failed to develop into the normal five-cell morphology, rather the three main-body cells separated via constriction at the original septum position to generate three independent mutant conidia. This result suggests a novel role of melanin in the formation of the multi-cellular conidia. Germ tubes could develop from the three different types of mutant conidia and kept elongating, despite a significantly lower germination rate was observed for them. Still more, the unpigmented conidia became permeable to Calcofluor White and DAPI, suggesting the integrity of the conidia was impaired. Deliberate inhibition of melanin biosynthesis by a specific inhibitor, tricyclazole, led to a similar phenotypes. This work demonstrates a new function of fungal melanin in conidial development.

  20. Rab11b mediates melanin transfer between donor melanocytes and acceptor keratinocytes via coupled exo/endocytosis.

    Science.gov (United States)

    Tarafder, Abul K; Bolasco, Giulia; Correia, Maria S; Pereira, Francisco J C; Iannone, Lucio; Hume, Alistair N; Kirkpatrick, Niall; Picardo, Mauro; Torrisi, Maria R; Rodrigues, Inês P; Ramalho, José S; Futter, Clare E; Barral, Duarte C; Seabra, Miguel C

    2014-04-01

    The transfer of melanin from melanocytes to keratinocytes is a crucial process underlying maintenance of skin pigmentation and photoprotection against UV damage. Here, we present evidence supporting coupled exocytosis of the melanin core, or melanocore, by melanocytes and subsequent endocytosis by keratinocytes as a predominant mechanism of melanin transfer. Electron microscopy analysis of human skin samples revealed three lines of evidence supporting this: (1) the presence of melanocores in the extracellular space; (2) within keratinocytes, melanin was surrounded by a single membrane; and (3) this membrane lacked the melanosomal membrane protein tyrosinase-related protein 1 (TYRP1). Moreover, co-culture of melanocytes and keratinocytes suggests that melanin exocytosis is specifically induced by keratinocytes. Furthermore, depletion of Rab11b, but not Rab27a, caused a marked decrease in both keratinocyte-stimulated melanin exocytosis and transfer to keratinocytes. Thus, we propose that the predominant mechanism of melanin transfer is keratinocyte-induced exocytosis, mediated by Rab11b through remodeling of the melanosome membrane, followed by subsequent endocytosis by keratinocytes.

  1. Dermoscopic findings and histological correlation of the acral volar pigmented maculae in Laugier-Hunziker syndrome.

    Science.gov (United States)

    Sendagorta, Elena; Feito, Marta; Ramírez, Paloma; Gonzalez-Beato, María; Saida, Toshiaki; Pizarro, Angel

    2010-11-01

    Laugier-Hunziker syndrome (LHS) is an acquired, benign, macular hyperpigmentation of the lips and oral mucosa, often associated with pigmentation of the nails. Volar acral maculae on the palms and fingertips of patients affected by LHS are a typical feature of this rare entity. Dermoscopic examination of these maculae has been described in a previous report, in which authors found a parallel-furrow pattern. We describe two cases in which a parallel-ridge pattern (PRP) was found on the dermoscopic examination of the pigmented acral lesions. Histological examination showed increased melanin in basal keratinocytes, which was most prominent in those located at the crista intermedia profunda, that is, in the epidermal rete ridges underlying the surface ridges. In our study, dermoscopic features of the pigmented maculae found on LHS differed from those previously described. In addition, by means of this case report, the histological features of these lesions are described for the first time, showing an excellent correlation with dermoscopy. The reported cases prove that although the PRP is very specific of melanoma, it is also possible to find it in benign lesions. Therefore, we must be familiar with the differential diagnosis of PRP, and take into consideration the clinical context in which we find it. Further studies are needed to increase our knowledge on the histological and dermoscopic features of acral pigmented maculae of LHS.

  2. Identification and molecular characterization of the homogentisate pathway responsible for pyomelanin production, the major melanin constituents in Aeromonas media WS.

    Science.gov (United States)

    Wang, He; Qiao, Yunqian; Chai, Baozhong; Qiu, Chenxi; Chen, Xiangdong

    2015-01-01

    The pigmentation of many Aeromonas species has been thought to be due to the production of a L-DOPA (L-3,4-dihydroxyphenylalanine) based melanin. However, in this study we found that although L-DOPA synthesis occurs in the high-melanin-yielding Aeromonas media strain WS, it plays a minor, if any, role in pigmentation. Instead, the pigmentation of A. media strain WS is due to the production of pyomelanin through HGA (homogentisate). Gene products of phhA (encodes phenylalanine hydroxylase), tyrB and aspC (both encode aromatic amino acid aminotransferase), and hppD (encodes 4-hydroxyphenylpyruvate dioxygenase) constitute a linear pathway of converting phenylalanine to HGA and disruption of any one of these genes impairs or blocks pigmentation of A. media strain WS. This HGA biosynthesis pathway is widely distributed in Aeromonas, but HGA is only detectable in the cultures of pigmented Aeromonas species. Heterologous expression of HppD from both pigmented and non-pigmented Aeromonas species in E. coli leads to the production of pyomelanin and thus pigmentation, suggesting that most Aeromonas species have the critical enzymes to produce pyomelanin through HGA. Taken together, we have identified a widely conserved biosynthesis pathway of HGA based pyomelanin in Aeromonas that may be responsible for pigmentation of many Aeromonas species.

  3. Identification and molecular characterization of the homogentisate pathway responsible for pyomelanin production, the major melanin constituents in Aeromonas media WS.

    Directory of Open Access Journals (Sweden)

    He Wang

    Full Text Available The pigmentation of many Aeromonas species has been thought to be due to the production of a L-DOPA (L-3,4-dihydroxyphenylalanine based melanin. However, in this study we found that although L-DOPA synthesis occurs in the high-melanin-yielding Aeromonas media strain WS, it plays a minor, if any, role in pigmentation. Instead, the pigmentation of A. media strain WS is due to the production of pyomelanin through HGA (homogentisate. Gene products of phhA (encodes phenylalanine hydroxylase, tyrB and aspC (both encode aromatic amino acid aminotransferase, and hppD (encodes 4-hydroxyphenylpyruvate dioxygenase constitute a linear pathway of converting phenylalanine to HGA and disruption of any one of these genes impairs or blocks pigmentation of A. media strain WS. This HGA biosynthesis pathway is widely distributed in Aeromonas, but HGA is only detectable in the cultures of pigmented Aeromonas species. Heterologous expression of HppD from both pigmented and non-pigmented Aeromonas species in E. coli leads to the production of pyomelanin and thus pigmentation, suggesting that most Aeromonas species have the critical enzymes to produce pyomelanin through HGA. Taken together, we have identified a widely conserved biosynthesis pathway of HGA based pyomelanin in Aeromonas that may be responsible for pigmentation of many Aeromonas species.

  4. Cladosporium cladosporioides LPSC 1088 produces the 1,8-dihydroxynaphthalene-melanin-like compound and carries a putative pks gene.

    Science.gov (United States)

    Llorente, Carla; Bárcena, Alejandra; Vera Bahima, José; Saparrat, Mario C N; Arambarri, Angélica M; Rozas, M Fernanda; Mirífico, María V; Balatti, Pedro A

    2012-12-01

    Cladosporium cladosporioides is a dematiaceous fungus with coloured mycelia and conidia due to the presence of dark pigments. The purpose of this study was to characterize the dark pigments synthetized by Cladosporium sp. LPSC no. 1088 and also to identify the putative polyketide synthase (pks) gene that might be involved in the pigment biosynthesis. Morphological as well as molecular features like the ITS sequence confirmed that LPSC 1088 is Cladosporium cladosporioides. UV-visible, Fourier Transform Infrared (FTIR) and Electron Spin Resonance (ESR) spectroscopy analysis as well as melanin inhibitors suggest that the main dark pigment of the isolate was 1,8 dihydroxynaphthalene (DHN)-melanin-type compound. Two commercial fungicides, Difenoconazole and Chlorothalonil, inhibited fungal growth as well as increased pigmentation of the colonies suggesting that melanin might protect the fungus against chemical stress. The pigment is most probably synthetized by means of a pentaketide pathway since the sequence of a 651 bp fragment, coding for a putative polyketide synthase, is highly homologous to pks sequences from other fungi.

  5. Interpreting melanin-based coloration through deep time: a critical review

    Science.gov (United States)

    Lindgren, Johan; Moyer, Alison; Schweitzer, Mary H.; Sjövall, Peter; Uvdal, Per; Nilsson, Dan E.; Heimdal, Jimmy; Engdahl, Anders; Gren, Johan A.; Schultz, Bo Pagh; Kear, Benjamin P.

    2015-01-01

    Colour, derived primarily from melanin and/or carotenoid pigments, is integral to many aspects of behaviour in living vertebrates, including social signalling, sexual display and crypsis. Thus, identifying biochromes in extinct animals can shed light on the acquisition and evolution of these biological traits. Both eumelanin and melanin-containing cellular organelles (melanosomes) are preserved in fossils, but recognizing traces of ancient melanin-based coloration is fraught with interpretative ambiguity, especially when observations are based on morphological evidence alone. Assigning microbodies (or, more often reported, their ‘mouldic impressions’) as melanosome traces without adequately excluding a bacterial origin is also problematic because microbes are pervasive and intimately involved in organismal degradation. Additionally, some forms synthesize melanin. In this review, we survey both vertebrate and microbial melanization, and explore the conflicts influencing assessment of microbodies preserved in association with ancient animal soft tissues. We discuss the types of data used to interpret fossil melanosomes and evaluate whether these are sufficient for definitive diagnosis. Finally, we outline an integrated morphological and geochemical approach for detecting endogenous pigment remains and associated microstructures in multimillion-year-old fossils. PMID:26290071

  6. Metal exposure influences the melanin and carotenoid-based colorations in great tits.

    Science.gov (United States)

    Giraudeau, M; Mateos-Gonzalez, F; Cotín, J; Pagani-Nuñez, E; Torné-Noguera, A; Senar, J C

    2015-11-01

    Metals are naturally found in the environment but are also emitted through anthropogenic activities, raising some concerns about the potential deleterious effects of these elements on wildlife. The potential effects of metals on bird coloration have been the focus of several recent studies since animal colored-signals often reflect the physiology of their bearers and are thus used by animals to assess the quality of another individual as a mate or competitor. These studies have shown that the melanin pigmentation seems to be positively associated and the carotenoid-based coloration negatively associated with metal exposure in wild birds. Although these studies have been very useful to show the associations between metal exposure and coloration, only few of them have actually quantified the levels of metal exposure at the individual level; always focusing on one or two of them. Here, we measured the concentrations of eight metals in great tits' feathers and then assessed how these levels of metals were associated with the carotenoid and melanin-based colorations. We found that the melanin pigmentation was positively associated with the copper concentration and negatively correlated with the chromium concentration in feathers. In addition, we have shown that the carotenoid-based coloration was negatively associated with the feather's mercury concentration. This study is the first one to identify some metals that might affect positively and negatively the deposition of melanin and carotenoid into the plumage of wild birds.

  7. Near-infrared autofluorescence imaging of cutaneous melanins and human skin in vivo

    Science.gov (United States)

    Han, Xiao; Lui, Harvey; McLean, David I.; Zeng, Haishan

    2009-03-01

    In recent years, near-infrared (NIR) autofluorescence imaging has been explored as a novel technique for tissue evaluation and diagnosis. We present an NIR fluorescence imaging system optimized for the dermatologic clinical setting, with particular utility for the direct characterization of cutaneous melanins in vivo. A 785-nm diode laser is coupled into a ring light guide to uniformly illuminate the skin. A bandpass filter is used to purify the laser light for fluorescence excitation, while a long-pass filter is used to block the main laser wavelength but pass the spontaneous components for NIR reflectance imaging. A computer-controlled filter holder is used to switch these two filters to select between reflectance and fluorescence imaging modes. Both the reflectance and fluorescence photons are collected by an NIR-sensitive charge-coupled device (CCD) camera to form the respective images. Preliminary results show that cutaneous melanin in pigmented skin disorders emits higher NIR autofluorescence than surrounding normal tissue. This confirmed our previous findings from NIR fluorescence spectroscopy study of cutaneous melanins and provides a new approach to directly image the distributions of cutaneous melanins in the skin. In-vivo NIR autofluorescence images may be useful for clinical evaluation and diagnosis of pigmented skin lesions, including melanoma.

  8. In ovo gene manipulation of melanocytes and their adjacent keratinocytes during skin pigmentation of chicken embryos.

    Science.gov (United States)

    Murai, Hidetaka; Tadokoro, Ryosuke; Sakai, Ken-Ichiro; Takahashi, Yoshiko

    2015-04-01

    During skin pigmentation in avians and mammalians, melanin is synthesized in the melanocytes, and subsequently transferred to adjacently located keratinocytes, leading to a wide coverage of the body surface by melanin-containing cells. The behavior of melanocytes is influenced by keratinocytes shown mostly by in vitro studies. However, it has poorly been investigated how such intercellular cross-talk is regulated in vivo because of a lack of suitable experimental models. Using chicken embryos, we developed a method that enables in vivo gene manipulations of melanocytes and keratinocytes, where these cells are separately labeled by different genes. Two types of gene transfer techniques were combined: one was a retrovirus-mediated gene infection into the skin/keratinocytes, and the other was the in ovo DNA electroporation into neural crest cells, the origin of melanocytes. Since the Replication-Competent Avian sarcoma-leukosis virus long terminal repeat with Splice acceptor (RCAS) infection was available only for the White leghorn strain showing little pigmentation, melanocytes prepared from the Hypeco nera (pigmented) were back-transplanted into embryos of White leghorn. Prior to the transplantation, enhanced green fluorescent protein (EGFP)(+) Neo(r+) -electroporated melanocytes from Hypeco nera were selectively grown in G418-supplemented medium. In the skin of recipient White leghorn embryos infected with RCAS-mOrange, mOrange(+) keratinocytes and transplanted EGFP(+) melanocytes were frequently juxtaposed each other. High-resolution confocal microscopy also revealed that transplanted melanocytes exhibited normal behaviors regarding distribution patterns of melanocytes, dendrite morphology, and melanosome transfer. The method described in this study will serve as a useful tool to understand the mechanisms underlying intercellular regulations during skin pigmentation in vivo.

  9. Melanin dependent survival of Apergillus fumigatus conidia in lung epithelial cells.

    Science.gov (United States)

    Amin, Shayista; Thywissen, Andreas; Heinekamp, Thorsten; Saluz, Hans Peter; Brakhage, Axel A

    2014-07-01

    Aspergillus fumigatus is the most important air-borne pathogenic fungus of humans. Upon inhalation of conidia, the fungus makes close contact with lung epithelial cells, which only possess low phagocytic activity. These cells are in particular interesting to address the question whether there is some form of persistence of conidia of A. fumigatus in the human host. Therefore, by also using uracil-auxotrophic mutant strains, we were able to investigate the interaction of A549 lung epithelial cells and A. fumigatus conidia in detail for long periods. Interestingly, unlike professional phagocytes, our study showed that the presence of conidial dihydroxynaphthalene (DHN) melanin enhanced the uptake of A. fumigatus conidia by epithelial cells when compared with non-pigmented pksP mutant conidia. Furthermore, conidia of A. fumigatus were able to survive within epithelial cells. This was due to the presence of DHN melanin in the cell wall of conidia, because melanised wild-type conidia showed a higher survival rate inside epithelial cells and led to inhibition of acidification of phagolysosomes. Both effects were not observed for white (non-melanised) conidia of the pksP mutant strain. Moreover, in contrast to pksP mutant conidia, melanised wild-type conidia were able to inhibit the extrinsic apoptotic pathway in A549 lung epithelial cells even for longer periods. The anti-apoptotic effect was not restricted to conidia, because both conidia-derived melanin ghosts (cell-free DHN melanin) and a different type of melanin, dihydroxyphenylalanine (DOPA) melanin, acted anti-apoptotically. Taken together, these data indicate the possibility of melanin-dependent persistence of conidia in lung epithelial cells.

  10. [The magnetic susceptibility of the melanin in the eyes of representatives of different vertebrate classes].

    Science.gov (United States)

    Zagal'skaia, E O

    1995-01-01

    The magnetoperceptivity (Chi) and element composition of eye pigment epitelium (EPE) melanin in vertebrate animals were measured. The minimal values of EPE Chi were found in winter-sleeping and anabiotic animals (Ursus arctos, Rana temporaria). The magnetoperception was high in migrating animals (Oncorhynchus keta, 0. gorbuscha, Anas crecca) and in wild gray rats as well, EPE magnetoperceptivity in albino rats wasn't practicaly established. In the majority of cases the quantity of magnetoperceptivity correlates with per-cent content of iron. The evident correlation between melanin magnet properties and the life strategy of the investigated animals allows to propose the participance of eye pigment epithelium in orientation and navigation of the animals.

  11. Evolutionary shifts in the melanin-based color system of birds.

    Science.gov (United States)

    Eliason, Chad M; Shawkey, Matthew D; Clarke, Julia A

    2016-02-01

    Melanin pigments contained in organelles (melanosomes) impart earthy colors to feathers. Such melanin-based colors are distributed across birds and thought to be the ancestral color-producing mechanism in birds. However, we have had limited data on melanin-based color and melanosome diversity in Palaeognathae, which includes the flighted tinamous and large-bodied, flightless ratites and is the sister taxon to all other extant birds. Here, we use scanning electron microscopy and spectrophotometry to assess melanosome morphology and quantify reflected color for 19 species within this clade. We find that brown colors in ratites are uniquely associated with elongated melanosomes nearly identical in shape to those associated with black colors. Melanosome and color diversity in large-bodied ratites is limited relative to other birds (including flightless penguins) and smaller bodied basal maniraptoran dinosaur outgroups of Aves, whereas tinamous show a wider range of melanosome forms similar to neognaths. The repeated occurrence of novel melanosome forms in the nonmonophyletic ratites suggests that melanin-based color tracks changes in body size, physiology, or other life history traits associated with flight loss, but not feather morphology. We further anticipate these findings will be useful for future color reconstructions in extinct species, as variation in melanosome shape may potentially be linked to a more nuanced palette of melanin-based colors.

  12. Singlet molecular oxygen generation by light-activated DHN-melanin of the fungal pathogen Mycosphaerella fijiensis in black Sigatoka disease of bananas.

    Science.gov (United States)

    Beltrán-García, Miguel J; Prado, Fernanda M; Oliveira, Marilene S; Ortiz-Mendoza, David; Scalfo, Alexsandra C; Pessoa, Adalberto; Medeiros, Marisa H G; White, James F; Di Mascio, Paolo

    2014-01-01

    In pathogenic fungi, melanin contributes to virulence, allowing tissue invasion and inactivation of the plant defence system, but has never been implicated as a factor for host cell death, or as a light-activated phytotoxin. Our research shows that melanin synthesized by the fungal banana pathogen Mycosphaerella fijiensis acts as a virulence factor through the photogeneration of singlet molecular oxygen O2 (1Δg). Using analytical tools, including elemental analysis, ultraviolet/infrared absorption spectrophometry and MALDI-TOF mass spectrometry analysis, we characterized both pigment content in mycelia and secreted to the culture media as 1,8-dihydroxynaphthalene (DHN)-melanin type compound. This is sole melanin-type in M. fijiensis. Isolated melanins irradiated with a Nd:YAG laser at 532 nm produced monomol light emission at 1270 nm, confirming generation of O2 (1Δg), a highly reactive oxygen specie (ROS) that causes cellular death by reacting with all cellular macromolecules. Intermediary polyketides accumulated in culture media by using tricyclazole and pyroquilon (two inhibitors of DHN-melanin synthesis) were identified by ESI-HPLC-MS/MS. Additionally, irradiation at 532 nm of that mixture of compounds and whole melanized mycelium also generated O2 (1Δg). A pigmented-strain generated more O2 (1Δg) than a strain with low melanin content. Banana leaves of cultivar Cavendish, naturally infected with different stages of black Sigatoka disease, were collected from field. Direct staining of the naturally infected leaf tissues showed the presence of melanin that was positively correlated to the disease stage. We also found hydrogen peroxide (H2O2) but we cannot distinguish the source. Our results suggest that O2 (1Δg) photogenerated by DHN-melanin may be involved in the destructive effects of Mycosphaerella fijiensis on banana leaf tissues. Further studies are needed to fully evaluate contributions of melanin-mediated ROS to microbial pathogenesis.

  13. Singlet molecular oxygen generation by light-activated DHN-melanin of the fungal pathogen Mycosphaerella fijiensis in black Sigatoka disease of bananas.

    Directory of Open Access Journals (Sweden)

    Miguel J Beltrán-García

    Full Text Available In pathogenic fungi, melanin contributes to virulence, allowing tissue invasion and inactivation of the plant defence system, but has never been implicated as a factor for host cell death, or as a light-activated phytotoxin. Our research shows that melanin synthesized by the fungal banana pathogen Mycosphaerella fijiensis acts as a virulence factor through the photogeneration of singlet molecular oxygen O2 (1Δg. Using analytical tools, including elemental analysis, ultraviolet/infrared absorption spectrophometry and MALDI-TOF mass spectrometry analysis, we characterized both pigment content in mycelia and secreted to the culture media as 1,8-dihydroxynaphthalene (DHN-melanin type compound. This is sole melanin-type in M. fijiensis. Isolated melanins irradiated with a Nd:YAG laser at 532 nm produced monomol light emission at 1270 nm, confirming generation of O2 (1Δg, a highly reactive oxygen specie (ROS that causes cellular death by reacting with all cellular macromolecules. Intermediary polyketides accumulated in culture media by using tricyclazole and pyroquilon (two inhibitors of DHN-melanin synthesis were identified by ESI-HPLC-MS/MS. Additionally, irradiation at 532 nm of that mixture of compounds and whole melanized mycelium also generated O2 (1Δg. A pigmented-strain generated more O2 (1Δg than a strain with low melanin content. Banana leaves of cultivar Cavendish, naturally infected with different stages of black Sigatoka disease, were collected from field. Direct staining of the naturally infected leaf tissues showed the presence of melanin that was positively correlated to the disease stage. We also found hydrogen peroxide (H2O2 but we cannot distinguish the source. Our results suggest that O2 (1Δg photogenerated by DHN-melanin may be involved in the destructive effects of Mycosphaerella fijiensis on banana leaf tissues. Further studies are needed to fully evaluate contributions of melanin-mediated ROS to microbial pathogenesis.

  14. Melanin directly converts light for vertebrate metabolic use: heuristic thoughts on birds, Icarus and dark human skin.

    Science.gov (United States)

    Goodman, Geoffrey; Bercovich, Dani

    2008-08-01

    Pigments serve many visually obvious animal functions (e.g. hair, skin, eyes, feathers, scales). One is 'melanin', unusual in an absorption across the UV-visual spectrum which is controversial. Any polymer or macro-structure of melanin monomers is 'melanin'. Its roles derive from complex structural and physical-chemical properties e.g. semiconductor, stable radical, conductor, free radical scavenger, charge-transfer. Clinicians and researchers are well acquainted with melanin in skin and ocular pathologies and now increasingly are with internal, melanized, pathology-associated sites not obviously subject to light radiation (e.g. brain, cochlea). At both types of sites some findings puzzle: positive and negative neuromelanin effects in Parkinsons; unexpected melanocyte action in the cochlea, in deafness; melanin reduces DNA damage, but can promote melanoma; in melanotic cells, mitochondrial number was 83% less, respiration down 30%, but development similar to normal amelanotic cells. A little known, avian anatomical conundrum may help resolve melanin paradoxes. One of many unique adaptations to flight, the pecten, strange intra-ocular organ with unresolved function(s), is much enlarged and heavily melanized in birds fighting gravity, hypoxia, thirst and hunger during long-distance, frequently sub-zero, non-stop migration. The pecten may help cope with energy and nutrient needs under extreme conditions, by a marginal but critical, melanin-initiated conversion of light to metabolic energy, coupled to local metabolite recycling. Similarly in Central Africa, reduction in body hair and melanin increase may also have lead to 'photomelanometabolism' which, though small scale/ unit body area, in total may have enabled a sharply increased development of the energy-hungry cortex and enhanced human survival generally. Animal inability to utilize light energy directly has been traditionally assumed. Melanin and the pecten may have unexpected lessons also for human physiology

  15. Toxicological and melanin synthesis effects of Polygonum multiflorum root extracts on zebrafish embryos and human melanocytes

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    Thanh Thi Hoai Dang

    2016-09-01

    Full Text Available Polygonum multiflorum (PM has been commmonly used as folk medicine for treatment of various conditions, such as early graying of hair in humans. However, there have been limited studies which have evaluated the toxicological and biological effects of PM in vitro as well as in vivo. In this study, PM root extracts in ethyl acetate (PM-E and in distilled water (PM-W were examined for their effects on the development of teratogenic defects/deaths. Additionally, they were evaluated for their effects on melanin formation in human melanocytes and pigmentation in embryos/larvae of wild type strain AB zebrafish (Danio rerio. Our results showed that PM root extracts at concentrations of 40 mg/L and 105 mg/L induced the development of teratogenic defects, including yolk sac edema (or heart edema, hemovascular defects, necrosis and abnormal trunk in zebrafish embryos at 4 days post fertilization; teratogenic indexes (TIs were 1.43 and 0.63 for ethyl acetate extract and distilled water extract, respectively. Our results also demonstrated that PM-W significantly increased the pigmentation level of embryos/larvae and induced melanin formation in human melanocytes. The amount of melanin in PM-W-exposed embryos/larvae was 2.2-fold and 1.71-fold greater than those in the control embryos/larvae and control melanocytes, respectively. Our study also showed that the increased level of pigmentation in PM-W embryos/larvae or melanin biosynthesis in melanocytes were both regulated by activation of tyrosinase. Conclusively, our study suggests that PM root extracts could be used as potential agents for treatment of early hair graying as well as various other diseases related to loss of pigmentation. However, these PM root extracts may also have some negative effects on embryos; therefore it should be careful when using for women during pregnancy. [Biomed Res Ther 2016; 3(9.000: 808-818

  16. The Protective Role of Melanin Against UV Damage in Human Skin

    OpenAIRE

    Brenner, Michaela; Hearing, Vincent J.

    2008-01-01

    Human skin is repeatedly exposed to ultraviolet radiation (UVR) that influences the function and survival of many cell types and is regarded as the main causative factor in the induction of skin cancer. It has been traditionally believed that skin pigmentation is the most important photoprotective factor, since melanin, besides functioning as a broadband UV absorbent, has antioxidant and radical scavenging properties. Besides, many epidemiological studies have shown a lower incidence for skin...

  17. Assessment of skin pigmentation by confocal microscopy: Influence of solar exposure and protection habits on cutaneous hyperchromias.

    Science.gov (United States)

    Martini, Ana Paula M; Mercurio, Daiane G; Maia Campos, Patrícia M B G

    2017-09-01

    Cutaneous hyperchromias are disorders of skin pigmentation involving an increase of melanin production and its irregular accumulation in skin cells. It is known that the use of sunscreens helps to prevent changes in the skin pigmentation pattern, but the structural and morphological alterations that occur in the different types of hyperpigmentations need better elucidation. To assess the influence of solar exposure and protection habits on the pattern of skin pigmentation using reflectance confocal microscopy (RCM). Forty volunteers aged 18-39 years with skin hyperpigmentation participated in the study. Skin characterization was performed by imaging techniques and by assessing the habits of solar exposure and protection by applying questionnaires to the volunteers. RCM was used to record sequences of confocal sections at areas of interest and to examine cell shape and brightness in the basal cell layer of the lesion and in normal perilesional skin. Furthermore, high-resolution images were obtained for analysis of the spots. Sunlight influences the number and location of spots as the face of volunteers with higher solar exposure was covered with spots, whereas volunteers with less exposure had fewer spots located in the nose and cheeks region due to greater exposure of these areas to the sun. The data showed the importance of sun protection for preventing changes in the pattern of skin pigmentation, and RCM proved to be an important tool for skin characterization. © 2017 Wiley Periodicals, Inc.

  18. The pbrB gene encodes a laccase required for DHN-melanin synthesis in conidia of Talaromyces (Penicillium) marneffei.

    Science.gov (United States)

    Sapmak, Ariya; Boyce, Kylie J; Andrianopoulos, Alex; Vanittanakom, Nongnuch

    2015-01-01

    Talaromyces marneffei (Basionym: Penicillium marneffei) is a significant opportunistic fungal pathogen in patients infected with human immunodeficiency virus in Southeast Asia. T. marneffei cells have been shown to become melanized in vivo. Melanins are pigment biopolymers which act as a non-specific protectant against various stressors and which play an important role during virulence in fungi. The synthesis of the two most commonly found melanins in fungi, the eumelanin DOPA-melanin and the allomelanin DHN-melanin, requires the action of laccase enzymes. The T. marneffei genome encodes a number of laccases and this study describes the characterization of one of these, pbrB, during growth and development. A strain carrying a PbrB-GFP fusion shows that pbrB is expressed at high levels during asexual development (conidiation) but not in cells growing vegetatively. The pbrB gene is required for the synthesis of DHN-melanin in conidia and when deleted results in brown pigmented conidia, in contrast to the green conidia of the wild type.

  19. Global patterns of diversity and selection in human tyrosinase gene.

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    Georgi Hudjashov

    Full Text Available Global variation in skin pigmentation is one of the most striking examples of environmental adaptation in humans. More than two hundred loci have been identified as candidate genes in model organisms and a few tens of these have been found to be significantly associated with human skin pigmentation in genome-wide association studies. However, the evolutionary history of different pigmentation genes is rather complex: some loci have been subjected to strong positive selection, while others evolved under the relaxation of functional constraints in low UV environment. Here we report the results of a global study of the human tyrosinase gene, which is one of the key enzymes in melanin production, to assess the role of its variation in the evolution of skin pigmentation differences among human populations. We observe a higher rate of non-synonymous polymorphisms in the European sample consistent with the relaxation of selective constraints. A similar pattern was previously observed in the MC1R gene and concurs with UV radiation-driven model of skin color evolution by which mutations leading to lower melanin levels and decreased photoprotection are subject to purifying selection at low latitudes while being tolerated or even favored at higher latitudes because they facilitate UV-dependent vitamin D production. Our coalescent date estimates suggest that the non-synonymous variants, which are frequent in Europe and North Africa, are recent and have emerged after the separation of East and West Eurasian populations.

  20. Deficiency in nucleotide excision repair family gene activity, especially ERCC3, is associated with non-pigmented hair fiber growth.

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    Mei Yu

    Full Text Available We conducted a microarray study to discover gene expression patterns associated with a lack of melanogenesis in non-pigmented hair follicles (HF by microarray. Pigmented and non-pigmented HFs were collected and micro-dissected into the hair bulb (HB and the upper hair sheaths (HS including the bulge region. In comparison to pigmented HS and HBs, nucleotide excision repair (NER family genes ERCC1, ERCC2, ERCC3, ERCC4, ERCC5, ERCC6, XPA, NTPBP, HCNP, DDB2 and POLH exhibited statistically significantly lower expression in non- pigmented HS and HBs. Quantitative PCR verified microarray data and identified ERCC3 as highly differentially expressed. Immunohistochemistry confirmed ERCC3 expression in HF melanocytes. A reduction in ERCC3 by siRNA interference in human melanocytes in vitro reduced their tyrosinase production ability. Our results suggest that loss of NER gene function is associated with a loss of melanin production capacity. This may be due to reduced gene transcription and/or reduced DNA repair in melanocytes which may eventually lead to cell death. These results provide novel information with regard to melanogenesis and its regulation.

  1. Compton scattering by internal shields based on melanin-containing mushrooms provides protection of gastrointestinal tract from ionizing radiation.

    Science.gov (United States)

    Revskaya, Ekaterina; Chu, Peter; Howell, Robertha C; Schweitzer, Andrew D; Bryan, Ruth A; Harris, Matthew; Gerfen, Gary; Jiang, Zewei; Jandl, Thomas; Kim, Kami; Ting, Li-Min; Sellers, Rani S; Dadachova, Ekaterina; Casadevall, Arturo

    2012-11-01

    There is a need for radioprotectors that protect normal tissues from ionizing radiation in patients receiving high doses of radiation and during nuclear emergencies. We investigated the possibility of creating an efficient oral radioprotector based on the natural pigment melanin that would act as an internal shield and protect the tissues via Compton scattering followed by free radical scavenging. CD-1 mice were fed melanin-containing black edible mushrooms Auricularia auricila-judae before 9 Gy total body irradiation. The location of the mushrooms in the body before irradiation was determined by in vivo fluorescent imaging. Black mushrooms protected 80% of mice from the lethal dose, while control mice or those given melanin-devoid mushrooms died from gastrointestinal syndrome. The crypts of mice given black mushrooms showed less apoptosis and more cell division than those in control mice, and their white blood cell and platelet counts were restored at 45 days to preradiation levels. The role of melanin in radioprotection was proven by the fact that mice given white mushrooms supplemented with melanin survived at the same rate as mice given black mushrooms. The ability of melanin-containing mushrooms to provide remarkable protection against radiation suggests that they could be developed into oral radioprotectors.

  2. Madecassoside Inhibits Melanin Synthesis by Blocking Ultraviolet-Induced Inflammation

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    Eunsun Jung

    2013-12-01

    Full Text Available Madecassoside (MA, a pentacyclic triterpene isolated from Centella asitica (L., is used as a therapeutic agent in wound healing and also as an anti-inflammatory and anti-aging agent. However, the involvement of MA in skin-pigmentation has not been reported. This study was conducted to investigate the effects of MA on ultraviolet (UV-induced melanogenesis and mechanisms in a co-culture system of keratinocytes and melanocytes. MA significantly inhibited UVR-induced melanin synthesis and melanosome transfer in the co-culture system. These effects were further demonstrated by the MA-induced inhibition of protease-activated receptor-2 expression and its signaling pathway, cyclooxygenase-2, prostaglandin E2 and prostaglandin F2 alpha in keratinocytes. The clinical efficacy of MA was confirmed on artificially tanned human skin. MA significantly reduced UV-induced melanin index at 8 weeks after topical application. Overall, the study demonstrated significant benefits of MA use in the inhibition of hyperpigmentation caused by UV irradiation.

  3. Hesperetin induces melanin production in adult human epidermal melanocytes.

    Science.gov (United States)

    Usach, Iris; Taléns-Visconti, Raquel; Magraner-Pardo, Lorena; Peris, José-Esteban

    2015-06-01

    One of the major sources of flavonoids for humans are citrus fruits, hesperidin being the predominant flavonoid. Hesperetin (HSP), the aglycon of hesperidin, has been reported to provide health benefits such as antioxidant, anti-inflammatory and anticarcinogenic effects. However, the effect of HSP on skin pigmentation is not clear. Some authors have found that HSP induces melanogenesis in murine B16-F10 melanoma cells, which, if extrapolated to in vivo conditions, might protect skin against photodamage. Since the effect of HSP on normal melanocytes could be different to that observed on melanoma cells, the described effect of HSP on murine melanoma cells has been compared to the effect obtained using normal human melanocytes. HSP concentrations of 25 and 50 µM induced melanin synthesis and tyrosinase activity in human melanocytes in a concentration-dependent manner. Compared to control melanocytes, 25 µM HSP increased melanin production and tyrosinase activity 1.4-fold (p melanocyte cultures could be reproduced on human skin.

  4. Comparison of Antioxidant Activities of Melanin Fractions from Chestnut Shell

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    Zeng-Yu Yao

    2016-04-01

    Full Text Available Chestnut shell melanin can be used as a colorant and antioxidant, and fractionated into three fractions (Fr. 1, Fr. 2, and Fr. 3 with different physicochemical properties. Antioxidant activities of the fractions were comparatively evaluated for the first time. The fractions exhibited different antioxidative potential in different evaluation systems. Fr. 1, which is only soluble in alkaline water, had the strongest peroxidation inhibition and superoxide anion scavenging activity; Fr. 2, which is soluble in alkaline water and hydrophilic organic solvents but insoluble in neutral and acidic water, had the greatest power to chelate ferrous ions; and Fr. 3, which is soluble both in hydrophilic organic solvents and in water at any pH conditions, had the greatest hydroxyl (·OH and 1,1-diphenyl-2-picryl-hydrazyl (DPPH· radicals scavenging abilities, reducing power, and phenolic content. The pigment fractions were superior to butylated hydroxytolune (BHT in ·OH and DPPH· scavenging and to ethylene diamine tetraacetic acid (EDTA in the Fe2+–chelation. They were inferior to BHT in peroxidation inhibition and O2·− scavenging and reducing power. However, BHT is a synthetic antioxidant and cannot play the colorant role. The melanin fractions might be used as effective biological antioxidant colorants.

  5. Melanocytes and melanin represent a first line of innate immunity against Candida albicans.

    Science.gov (United States)

    Tapia, Cecilia V; Falconer, Maryanne; Tempio, Fabián; Falcón, Felipe; López, Mercedes; Fuentes, Marisol; Alburquenque, Claudio; Amaro, José; Bucarey, Sergio A; Di Nardo, Anna

    2014-07-01

    Melanocytes are dendritic cells located in the skin and mucosae that synthesize melanin. Some infections induce hypo- or hyperpigmentation, which is associated with the activation of Toll-like receptors (TLRs), especially TLR4. Candida albicans is an opportunist pathogen that can switch between blastoconidia and hyphae forms; the latter is associated with invasion. Our objectives in this study were to ascertain whether C. albicans induces pigmentation in melanocytes and whether this process is dependent on TLR activation, as well as relating this with the antifungal activity of melanin as a first line of innate immunity against fungal infections. Normal human melanocytes were stimulated with C. albicans supernatants or with crude extracts of the blastoconidia or hyphae forms, and pigmentation and TLR2/TLR4 expression were measured. Expression of the melanosomal antigens Melan-A and gp100 was examined for any correlation with increased melanin levels or antifungal activity in melanocyte lysates. Melanosomal antigens were induced earlier than cell pigmentation, and hyphae induced stronger melanization than blastoconidia. Notably, when melanocytes were stimulated with crude extracts of C. albicans, the cell surface expression of TLR2/TLR4 began at 48 h post-stimulation and peaked at 72 h. At this time, blastoconidia induced both TLR2 and TLR4 expression, whereas hyphae only induced TLR4 expression. Taken together, these results suggest that melanocytes play a key role in innate immune responses against C. albicans infections by recognizing pathogenic forms of C. albicans via TLR4, resulting in increased melanin content and inhibition of infection.

  6. A gene expression study of dorso-ventrally restricted pigment pattern in adult fins of Neolamprologus meeli, an African cichlid species

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    Ehsan Pashay Ahi

    2017-01-01

    Full Text Available Fish color patterns are among the most diverse phenotypic traits found in the animal kingdom. Understanding the molecular and cellular mechanisms that control in chromatophore distribution and pigmentation underlying this diversity is a major goal in developmental and evolutionary biology, which has predominantly been pursued in the zebrafish model system. Here, we apply results from zebrafish work to study a naturally occurring color pattern phenotype in the fins of an African cichlid species from Lake Tanganyika. The cichlid fish Neolamprologus meeli displays a distinct dorsal color pattern, with black and white stripes along the edges of the dorsal fin and of the dorsal half of the caudal fin, corresponding with differences in melanophore density. To elucidate the molecular mechanisms controlling the differences in dorsal and ventral color patterning in the fins, we quantitatively assessed the expression of 15 candidate target genes involved in adult zebrafish pigmentation and stripe formation. For reference gene validation, we screened the expression stability of seven widely expressed genes across the investigated tissue samples and identified tbp as appropriate reference. Relative expression levels of the candidate target genes were compared between the dorsal, striped fin regions and the corresponding uniform, grey-colored regions in the anal and ventral caudal fin. Dorso-ventral expression differences, with elevated levels in both white and black stripes, were observed in two genes, the melanosome protein coding gene pmel and in igsf11, which affects melanophore adhesion, migration and survival. Next, we predicted potential shared upstream regulators of pmel and igsf11. Testing the expression patterns of six predicted transcriptions factors revealed dorso-ventral expression difference of irf1 and significant, negative expression correlation of irf1 with both pmel and igsf11. Based on these results, we propose pmel, igsf11 and irf1 as

  7. Variation in melanin content and composition in type V and VI photoexposed and photoprotected human skin: the dominant role of DHI.

    Science.gov (United States)

    Alaluf, S; Heath, A; Carter, N; Atkins, D; Mahalingam, H; Barrett, K; Kolb, R; Smit, N

    2001-10-01

    A combination of techniques, including high-performance liquid chromatography (HPLC), spectrophotometric measurements, and a novel method for quantifying melanosome morphology, were applied to the analysis of melanin content and composition in highly pigmented (Fitzpatrick type V and VI) human skin. We found that total epidermal melanin content is significantly elevated in photoexposed type V and VI skin (approximately 1.6 x), while analysis of individual melanin components suggests that pheomelanin content increases only slightly, whereas 5,6-dihydroxyindole-2-carboxylic acid (DHICA)-eumelanin and to a greater extent 5,6-dihydroxyindole (DHI)-eumelanin content are both markedly elevated. Analysis of the relative composition of epidermal melanin in these subjects revealed that DHI-eumelanin is the largest single component (approximately 60-70%), followed by DHICA-eumelanin (25-35%), with pheomelanin being a relatively minor component (2-8%). Moreover, there was a comparative enrichment of DHI-eumelanin at photoexposed sites, with a corresponding decline in the relative contributions from DHICA-eumelanin and pheomelanin. There was also a good correlation and close agreement between the concentration of spheroidal melanosomes determined by morphological image analysis and the concentration of pheomelanin determined by a combination of HPLC and spectrophotometric analysis (r = 0.89, P DHI-eumelanin formation is the dominant pathway for melanin synthesis in heavily pigmented (Fitzpatrick V and VI) skin types in vivo, and is the favoured pathway when melanin production is increased in chronically photoexposed skin.

  8. Melanins as biomarkers of ovarian follicular atresia in the catfish Heteropneustes fossilis: biochemical and histochemical characterization, seasonal variation and hormone effects.

    Science.gov (United States)

    Kumar, Ravi; Joy, Keerikkattil P

    2015-06-01

    Follicular atresia is a common feature of the vertebrate ovary that occurs at different stages of folliculogenesis and ovarian regression. It has physiological significance to maintain homeostasis and control fecundity, and ensure removal of post-ovulatory follicular remnants for preparing the ovary for the next cycle. Pigments appear late in the atretic process as indigestible waste formed out of the degradation of the oocytes, follicle wall and granulocytes. In the present study, pigment accumulation was demonstrated by Schmorl's and Perls' staining methods in the atretic ovarian follicles of Heteropneustes fossilis during follicular development and regression. Melanins were characterized spectrophotometrically for the first time in fish ovary. The predominant form is eumelanin, followed by pheomelanin and alkali-soluble melanin. Melanins showed significant seasonal variations with levels low in gonad resting phase, increasing to the peak in the post-spawning phase. The concentration of melanins increased time-dependently in post-ovulated ovary after human chorionic gonadotropin treatment. In the spawning phase, in vitro incubation of ovary slices with estradiol-17β or dexamethasone for 8 or 16 h decreased both eumelanin and pheomelanin levels time-dependently. The alkali-soluble melanin showed a significant decrease only in the dexamethasone group at 16 h. The results show that melanin assay can be used as a biomarker of follicular atresia in fish ovary, natural or induced by environmental toxicants.

  9. Effect of Purified Mushroom Tyrosinase on Melanin Content and Melanogenic Protein Expression

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    Kamal Uddin Zaidi

    2016-01-01

    Full Text Available In mammalian melanocytes, melanosome is a highly specialized organelle where melanin is synthesized. Melanin synthesis is controlled by tyrosinase, the vital enzyme in melanogenic pathway. The present investigation is based on an effect of purified mushroom tyrosinase of Agaricus bisporus on B16F10 melanocytes for the melanin production via blocking pigment cell machinery. Using B16F10 melanocytes showed that the stimulation of melanogenesis by purified tyrosinase is due to increased tyrosinase absorption. Cellular tyrosinase activity and melanin content in B16F10 melanocytes were increased by purified tyrosinase in a dose-dependent manner. Western blot analysis revealed that cellular tyrosinase levels were enhanced after treatment with purified tyrosinase for 48 hours. Furthermore, tyrosinase induced phosphorylation of cyclic adenosine monophosphate (cAMP response element-binding protein (CREB in a dose-dependent manner. The purified tyrosinase-mediated increase of tyrosinase activity was significantly attenuated by H89, LY294002, Ro-32-0432, and PD98059, cAMP-dependent protein kinase inhibitors. The results indicate that purified tyrosinase can be used as contestant for the treatment of vitiligous skin conditions.

  10. Effect of Purified Mushroom Tyrosinase on Melanin Content and Melanogenic Protein Expression

    Science.gov (United States)

    Ali, Ayesha S.

    2016-01-01

    In mammalian melanocytes, melanosome is a highly specialized organelle where melanin is synthesized. Melanin synthesis is controlled by tyrosinase, the vital enzyme in melanogenic pathway. The present investigation is based on an effect of purified mushroom tyrosinase of Agaricus bisporus on B16F10 melanocytes for the melanin production via blocking pigment cell machinery. Using B16F10 melanocytes showed that the stimulation of melanogenesis by purified tyrosinase is due to increased tyrosinase absorption. Cellular tyrosinase activity and melanin content in B16F10 melanocytes were increased by purified tyrosinase in a dose-dependent manner. Western blot analysis revealed that cellular tyrosinase levels were enhanced after treatment with purified tyrosinase for 48 hours. Furthermore, tyrosinase induced phosphorylation of cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB) in a dose-dependent manner. The purified tyrosinase-mediated increase of tyrosinase activity was significantly attenuated by H89, LY294002, Ro-32-0432, and PD98059, cAMP-dependent protein kinase inhibitors. The results indicate that purified tyrosinase can be used as contestant for the treatment of vitiligous skin conditions. PMID:27699070

  11. Fourier transform infrared spectroscopy for sepia melanin

    CSIR Research Space (South Africa)

    Mbonyiryivuze, A

    2015-08-01

    Full Text Available intensively studied biomolecule systems such as nucleic acid, proteins and carbohydrates. Melanins have been reported to have a diverse number of functions in the biosystem, including photosensitization, metal ion chelation, photoprotection to absorb a broad...

  12. Using Sepia melanin as a PD model to describe the binding characteristics of neuromelanin - A critical review.

    Science.gov (United States)

    Schroeder, Rhiannon L; Double, Kay L; Gerber, Jacobus P

    2015-01-01

    Parkinson's disease is characterised pathologically by a relatively selective death of dopaminergic neurons in the substantia nigra of the brain. The vulnerability of these neurons appears to be linked to the pigment neuromelanin. However, as yet there is limited understanding behind the mechanisms of this disease process. Complications arise due to the difficulty in obtaining appreciable quantities of neuromelanin. Furthermore, an appropriate model for studying neuromelanin has not been identified. To date there has been many studies looking at the binding and chemical characteristics of neuromelanin. However, a range of different synthetic and organic melanins have been used as models and leading to many varied conclusions being drawn. Therefore, the aim of this review is to present Sepia melanin as the most appropriate study model for the binding characteristics of neuromelanin. Considerations included chemical structure, surface characteristics and structural features of both synthetic and organic melanins.

  13. Activation of muscarinic acetylcholine receptors elicits pigment granule dispersion in retinal pigment epithelium isolated from bluegill

    Science.gov (United States)

    González, Alfredo; Crittenden, Elizabeth L; García, Dana M

    2004-01-01

    Background In fish, melanin pigment granules in the retinal pigment epithelium disperse into apical projections as part of the suite of responses the eye makes to bright light conditions. This pigment granule dispersion serves to reduce photobleaching and occurs in response to neurochemicals secreted by the retina. Previous work has shown that acetylcholine may be involved in inducing light-adaptive pigment dispersion. Acetylcholine receptors are of two main types, nicotinic and muscarinic. Muscarinic receptors are in the G-protein coupled receptor superfamily, and five different muscarinic receptors have been molecularly cloned in human. These receptors are coupled to adenylyl cyclase, calcium mobilization and ion channel activation. To determine the receptor pathway involved in eliciting pigment granule migration, we isolated retinal pigment epithelium from bluegill and subjected it to a battery of cholinergic agents. Results The general cholinergic agonist carbachol induces pigment granule dispersion in isolated retinal pigment epithelium. Carbachol-induced pigment granule dispersion is blocked by the muscarinic antagonist atropine, by the M1 antagonist pirenzepine, and by the M3 antagonist 4-DAMP. Pigment granule dispersion was also induced by the M1 agonist 4-[N-(4-chlorophenyl) carbamoyloxy]-4-pent-2-ammonium iodide. In contrast the M2 antagonist AF-DX 116 and the M4 antagonist tropicamide failed to block carbachol-induced dispersion, and the M2 agonist arecaidine but-2-ynyl ester tosylate failed to elicit dispersion. Conclusions Our results suggest that carbachol-mediated pigment granule dispersion occurs through the activation of Modd muscarinic receptors, which in other systems couple to phosphoinositide hydrolysis and elevation of intracellular calcium. This conclusion must be corroborated by molecular studies, but suggests Ca2+-dependent pathways may be involved in light-adaptive pigment dispersion. PMID:15251036

  14. Activation of muscarinic acetylcholine receptors elicits pigment granule dispersion in retinal pigment epithelium isolated from bluegill

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    Crittenden Elizabeth L

    2004-07-01

    Full Text Available Abstract Background In fish, melanin pigment granules in the retinal pigment epithelium disperse into apical projections as part of the suite of responses the eye makes to bright light conditions. This pigment granule dispersion serves to reduce photobleaching and occurs in response to neurochemicals secreted by the retina. Previous work has shown that acetylcholine may be involved in inducing light-adaptive pigment dispersion. Acetylcholine receptors are of two main types, nicotinic and muscarinic. Muscarinic receptors are in the G-protein coupled receptor superfamily, and five different muscarinic receptors have been molecularly cloned in human. These receptors are coupled to adenylyl cyclase, calcium mobilization and ion channel activation. To determine the receptor pathway involved in eliciting pigment granule migration, we isolated retinal pigment epithelium from bluegill and subjected it to a battery of cholinergic agents. Results The general cholinergic agonist carbachol induces pigment granule dispersion in isolated retinal pigment epithelium. Carbachol-induced pigment granule dispersion is blocked by the muscarinic antagonist atropine, by the M1 antagonist pirenzepine, and by the M3 antagonist 4-DAMP. Pigment granule dispersion was also induced by the M1 agonist 4-[N-(4-chlorophenyl carbamoyloxy]-4-pent-2-ammonium iodide. In contrast the M2 antagonist AF-DX 116 and the M4 antagonist tropicamide failed to block carbachol-induced dispersion, and the M2 agonist arecaidine but-2-ynyl ester tosylate failed to elicit dispersion. Conclusions Our results suggest that carbachol-mediated pigment granule dispersion occurs through the activation of Modd muscarinic receptors, which in other systems couple to phosphoinositide hydrolysis and elevation of intracellular calcium. This conclusion must be corroborated by molecular studies, but suggests Ca2+-dependent pathways may be involved in light-adaptive pigment dispersion.

  15. Interaction of minoxidil with pigment in cells of the hair follicle: an example of binding without apparent biological effects.

    Science.gov (United States)

    Buhl, A E; Kawabe, T T; MacCallum, D K; Waldon, D J; Knight, K A; Johnson, G A

    1992-01-01

    To identify minoxidil target cells in hair follicles we followed the uptake of radiolabeled drug in mouse vibrissae follicles both in vitro and in vivo. Autoradiography showed that both 3H-minoxidil and 3H-minoxidil sulfate accumulated in the differentiating epithelial matrix cells superior to the dermal papilla, a distribution similar to that of pigment. Minoxidil localized in melanocytes, melanocyte processes, and areas of greater melanin concentrations within the epithelial cells. Although uptake of minoxidil was significantly less in unpigmented follicles, the drug stimulated proliferation and differentiation of both pigmented and unpigmented follicles. Labeled minoxidil bound to Sepia melanin and was displaced with unlabeled minoxidil and other electron donor drugs. This interaction with melanin acts as a targeting mechanism of minoxidil to pigmented hair follicles but has no apparent functional significance in hair growth. This work illustrates how measurement of drugs in hair may be biased by pigmentation.

  16. SWS2 visual pigment evolution as a test of historically contingent patterns of plumage color evolution in warblers.

    Science.gov (United States)

    Bloch, Natasha I; Morrow, James M; Chang, Belinda S W; Price, Trevor D

    2015-02-01

    Distantly related clades that occupy similar environments may differ due to the lasting imprint of their ancestors-historical contingency. The New World warblers (Parulidae) and Old World warblers (Phylloscopidae) are ecologically similar clades that differ strikingly in plumage coloration. We studied genetic and functional evolution of the short-wavelength-sensitive visual pigments (SWS2 and SWS1) to ask if altered color perception could contribute to the plumage color differences between clades. We show SWS2 is short-wavelength shifted in birds that occupy open environments, such as finches, compared to those in closed environments, including warblers. Phylogenetic reconstructions indicate New World warblers were derived from a finch-like form that colonized from the Old World 15-20 Ma. During this process, the SWS2 gene accumulated six substitutions in branches leading to New World warblers, inviting the hypothesis that passage through a finch-like ancestor resulted in SWS2 evolution. In fact, we show spectral tuning remained similar across warblers as well as the finch ancestor. Results reject the hypothesis of historical contingency based on opsin spectral tuning, but point to evolution of other aspects of visual pigment function. Using the approach outlined here, historical contingency becomes a generally testable theory in systems where genotype and phenotype can be connected.

  17. Study of melanin bleaching after immunohistochemistry of melanin-containing tissues.

    Science.gov (United States)

    Shen, Hongwu; Wu, Wenqiao

    2015-04-01

    Melanin may interfere with immunohistochemical staining. The goal of this study was to investigate the effects of trichloroisocyanuric acid (TCCA) bleaching, potassium permanganate bleaching, and potassium dichromate bleaching on melanin, tissue antigen, and 3,3'-diaminobenzidine (DAB) using melanin-containing and melanin-free tissue samples. Our results demonstrated that all 3 bleaching methods efficiently bleached melanin and partially destroyed tissue antigen. In addition, potassium permanganate bleaching and potassium dichromate bleaching clearly destroyed DAB, whereas TCCA bleaching had no significant effect on DAB. Therefore, neither potassium permanganate nor potassium dichromate is an ideal solution, whereas TCCA might be an ideal solution for melanin bleaching after the immunohistochemical staining of melanin-containing tissues. After immunostaining followed by TCCA bleaching, the melanin could be completely removed in all 120 malignant melanoma tissue sections. Compared with the control, the DAB intensity was clear, and the tissue structure and cellular nuclei were well maintained. It is worth noting that TCCA should be freshly prepared before each experiment, and used within 2 hours of its preparation. In addition, sections should not be incubated with TCCA for over 30 minutes.

  18. Effects of disrupting the polyketide synthase gene WdPKS1 in Wangiella [Exophiala] dermatitidis on melanin production and resistance to killing by antifungal compounds, enzymatic degradation, and extremes in temperature

    Directory of Open Access Journals (Sweden)

    Mandal Piyali

    2006-06-01

    Full Text Available Abstract Background Wangiella dermatitidis is a human pathogenic fungus that is an etiologic agent of phaeohyphomycosis. W. dermatitidis produces a black pigment that has been identified as a dihydroxynaphthalene melanin and the production of this pigment is associated with its virulence. Cell wall pigmentation in W. dermatitidis depends on the WdPKS1 gene, which encodes a polyketide synthase required for generating the key precursor for dihydroxynaphthalene melanin biosynthesis. Results We analyzed the effects of disrupting WdPKS1 on dihydroxynaphthalene melanin production and resistance to antifungal compounds. Transmission electron microscopy revealed that wdpks1Δ-1 yeast had thinner cell walls that lacked an electron-opaque layer compared to wild-type cells. However, digestion of the wdpks1Δ-1 yeast revealed small black particles that were consistent with a melanin-like compound, because they were acid-resistant, reacted with melanin-binding antibody, and demonstrated a free radical signature by electron spin resonance analysis. Despite lacking the WdPKS1 gene, the mutant yeast were capable of catalyzing the formation of melanin from L-3,4-dihyroxyphenylalanine. The wdpks1Δ-1 cells were significantly more susceptible to killing by voriconazole, amphotericin B, NP-1 [a microbicidal peptide], heat and cold, and lysing enzymes than the heavily melanized parental or complemented strains. Conclusion In summary, W. dermatitidis makes WdPKS-dependent and -independent melanins, and the WdPKS1-dependent deposition of melanin in the cell wall confers protection against antifungal agents and environmental stresses. The biological role of the WdPKS-independent melanin remains unclear.

  19. Photochemistry. Chemiexcitation of melanin derivatives induces DNA photoproducts long after UV exposure.

    Science.gov (United States)

    Premi, Sanjay; Wallisch, Silvia; Mano, Camila M; Weiner, Adam B; Bacchiocchi, Antonella; Wakamatsu, Kazumasa; Bechara, Etelvino J H; Halaban, Ruth; Douki, Thierry; Brash, Douglas E

    2015-02-20

    Mutations in sunlight-induced melanoma arise from cyclobutane pyrimidine dimers (CPDs), DNA photoproducts that are typically created picoseconds after an ultraviolet (UV) photon is absorbed at thymine or cytosine. We found that in melanocytes, CPDs are generated for >3 hours after exposure to UVA, a major component of the radiation in sunlight and in tanning beds. These "dark CPDs" constitute the majority of CPDs and include the cytosine-containing CPDs that initiate UV-signature C→T mutations. Dark CPDs arise when UV-induced reactive oxygen and nitrogen species combine to excite an electron in fragments of the pigment melanin. This creates a quantum triplet state that has the energy of a UV photon but induces CPDs by energy transfer to DNA in a radiation-independent manner. Melanin may thus be carcinogenic as well as protective against cancer. These findings also validate the long-standing suggestion that chemically generated excited electronic states are relevant to mammalian biology.

  20. Human eccrine sweat gland cells turn into melanin-uptaking keratinocytes in dermo-epidermal skin substitutes.

    Science.gov (United States)

    Böttcher-Haberzeth, Sophie; Biedermann, Thomas; Pontiggia, Luca; Braziulis, Erik; Schiestl, Clemens; Hendriks, Bart; Eichhoff, Ossia M; Widmer, Daniel S; Meuli-Simmen, Claudia; Meuli, Martin; Reichmann, Ernst

    2013-02-01

    Recently, Biedermann et al. (2010) have demonstrated that human eccrine sweat gland cells can develop a multilayered epidermis. The question still remains whether these cells can fulfill exclusive and very specific functional properties of epidermal keratinocytes, such as the incorporation of melanin, a feature absent in sweat gland cells. We added human melanocytes to eccrine sweat gland cells to let them develop into an epidermal analog in vivo. The interaction between melanocytes and sweat gland-derived keratinocytes was investigated. The following results were gained: (1) macroscopically, a pigmentation of the substitutes was seen 2-3 weeks after transplantation; (2) we confirmed the development of a multilayered, stratified epidermis with melanocytes distributed evenly throughout the basal layer; (3) melanocytic dendrites projected to suprabasal layers; and (4) melanin was observed to be integrated into former eccrine sweat gland cells. These skin substitutes were similar or equal to skin substitutes cultured from human epidermal keratinocytes. The only differences observed were a delay in pigmentation and less melanin uptake. These data suggest that eccrine sweat gland cells can form a functional epidermal melanin unit, thereby providing striking evidence that they can assume one of the most characteristic keratinocyte properties.

  1. Community analysis of pigment patterns from 37 microalgae strains reveals new carotenoids and porphyrins characteristic of distinct strains and taxonomic groups

    National Research Council Canada - National Science Library

    Serive, Benoît; Nicolau, Elodie; Bérard, Jean-Baptiste; Kaas, Raymond; Pasquet, Virginie; Picot, Laurent; Cadoret, Jean-Paul

    2017-01-01

    ... the different algal classes. High performance liquid chromatography is the gold standard method for qualitative and quantitative analysis of phytoplankton pigments in seawater and culture samples, but only a few pigments can...

  2. A pigmented calcifying cystic odontogenic tumor associated with compound odontoma: a case report and review of literature

    Directory of Open Access Journals (Sweden)

    Borkosky Silvia S

    2007-09-01

    Full Text Available Abstract Background Pigmented intraosseous odontogenic lesions are rare with only 47 reported cases in the English literature. Among them, pigmented calcifying cystic odontogenic tumor, formerly known as calcifying odontogenic cyst, is the most common lesion with 20 reported cases. Methods A case of pigmented calcifying cystic odontogenic tumor associated with odontoma occurring at the mandibular canine-premolar region of a young Japanese boy is presented with radiographic, and histological findings. Special staining, electron microscopic study and immunohistochemical staining were also done to characterize the pigmentation. Results The pigments in the lesion were confirmed to be melanin by Masson-Fontana staining and by transmission electron microscopy. The presence of dendritic melanocytes within the lesion was also demonstrated by S-100 immunostaining. Conclusion The present case report of pigmented calcifying cystic odontogenic tumor associated with odontoma features a comprehensive study on melanin and melanocytes, including histochemical, immunohistochemical and transmission electron microscopic findings.

  3. Microbial Production of Food Grade Pigments

    Directory of Open Access Journals (Sweden)

    Laurent Dufossé

    2006-01-01

    Full Text Available The controversial topic of synthetic dyes in food has been discussed for many years. The scrutiny and negative assessment of synthetic food dyes by the modern consumer have raised a strong interest in natural colouring alternatives. Nature is rich in colours (minerals, plants, microalgae, etc., and pigment-producing microorganisms (fungi, yeasts, bacteria are quite common. Among the molecules produced by microorganisms are carotenoids, melanins, flavins, quinones, and more specifically monascins, violacein or indigo. The success of any pigment produced by fermentation depends upon its acceptability on the market, regulatory approval, and the size of the capital investment required to bring the product to market. A few years ago, some expressed doubts about the successful commercialization of fermentation-derived food grade pigments because of the high capital investment requirements for fermentation facilities and the extensive and lengthy toxicity studies required by regulatory agencies. Public perception of biotechnology-derived products also had to be taken into account. Nowadays some fermentative food grade pigments are on the market: Monascus pigments, astaxanthin from Xanthophyllomyces dendrorhous, Arpink Red from Penicillium oxalicum, riboflavin from Ashbya gossypii, b-carotene from Blakeslea trispora. The successful marketing of pigments derived from algae or extracted from plants, both as a food colour and a nutritional supplement, reflects the presence and importance of niche markets in which consumers are willing to pay a premium for »all natural ingredients«.

  4. Two-photon excited fluorescence spectroscopy and imaging of melanin in vitro and in vivo

    Science.gov (United States)

    Krasieva, Tatiana B.; Liu, Feng; Sun, Chung-Ho; Kong, Yu; Balu, Mihaela; Meyskens, Frank L.; Tromberg, Bruce J.

    2012-03-01

    The ability to detect early melanoma non-invasively would improve clinical outcome and reduce mortality. Recent advances in two-photon excited fluorescence (TPEF) in vivo microscopy offer a powerful tool in early malignant melanoma diagnostics. The goal of this work was to develop a TPEF optical index for measuring relative concentrations of eumelanin and pheomelanin since ex vivo studies show that changes in this ratio have been associated with malignant transformation. We acquired TPEF emission spectra (λex=1000 nm) of melanin from several specimens, including human hair, malignant melanoma cell lines, and normal melanocytes and keratinocytes in different skin layers (epidermis, papillary dermis) in five healthy volunteers in vivo. We found that the pheomelanin emission peaks at around 620 nm and is blue-shifted from the eumelanin with broad maximum at 640-680nm. We defined "optical melanin index" (OMI) as a ratio of fluorescence signal intensities measured at 645 nm and 615nm. The measured OMI for a melanoma cell line MNT-1 was 1.6+/-0.2. The MNT-46 and MNT-62 lines (Mc1R gene knockdown) showed an anticipated change in melanins production ratio and had OMI of 0.55+/-0.05 and 0.17+/-0.02, respectively, which strongly correlated with HPLC data obtained for these lines. Average OMI measured for basal cells layers (melanocytes and keratinocytes) in normal human skin type I, II-III (not tanned and tanned) in vivo was 0.5, 1.05 and 1.16 respectively. We could not dependably detect the presence of pheomelanin in highly pigmented skin type V-VI. These data suggest that a non-invasive TPEF index could potentially be used for rapid melanin ratio characterization both in vitro and in vivo, including pigmented lesions.

  5. Melanin-targeted nonlinear microscopy for label-free molecular diagnosis and staining (Conference Presentation)

    Science.gov (United States)

    Warren, Warren S.

    2017-02-01

    Visible absorption in tissue is dominated by a very small number of chromophores (hemoglobins and melanins) with broad optical spectra; for melanins in particular, the optical absorption spectrum is typically featureless. In addition, scattering limits penetration depth. As a result, the most common microscopy application by far is with excised tissue, which can be stained. However, nonlinear optical methods have the additional advantages of greater penetration depth and reduced sensitivity to scattering. Traditional nonlinear microscopy relies on mechanisms which produce light of a different color than the irradiating lasers, such as second harmonic generation or two photon induced fluorescence, and this contrast is sparse in biological issue without expressing or injecting different chromophores. Recently, stable laser sources and pulse shaping/pulse train modulation methods have made it possible to detect a much wider range of nonlinear molecular signatures, even at modest laser powers (much less than a laser pointer). Here we show the utility of a variety of such signatures (pump-probe, pulse-shaped stimulated Raman, cross-phase modulation) to quantitatively image the biochemical composition of transparent or pigmented tissue in a variety of applications, ranging from thin, unstained tissue sections to live knockout mice. The rich biochemical information provided by this method can be used as an indicator of melanocyte activity, which in turn (for example) reflects the status of melanocytic lesions. Comparisons with model systems (synthetic melanin nanoparticles, sepia melanin) and analysis of melanin degradation pathways in vivo have led to a quantitative understanding of the molecular basis of these changes.

  6. Characterization of human hair melanin and its degradation products by means of magnetic resonance techniques.

    Science.gov (United States)

    Ghiani, Simona; Baroni, Simona; Burgio, Daniela; Digilio, Giuseppe; Fukuhara, Masaki; Martino, Paola; Monda, Keiji; Nervi, Carlo; Kiyomine, Akira; Aime, Silvio

    2008-05-01

    Melanin granules (MGs) have been extracted from human Chinese black hairs by either acid hydrolysis (CH-type MGs) or enzymatic digestion (CP-type MGs), and their chemical structure investigated at the solid state by means of (13)C cross polarization magic angle spinning (CPMAS NMR) and EPR spectroscopy. Both types of MGs contain a large amount of protein that is tightly bound to the true melanin polymer, with CP-type MGs having a larger protein content than CH-type ones. Moreover, MGs may also contain variable amounts of lipid-like material. A high amount of paramagnetic metals is detected by EPR in CP-type MGs, in particular Fe(III). Iron can be bound in two chemical forms: as isolated high spin Fe(III) ions with rhombic symmetry and as small oxy-hydroxy Fe(III) aggregates. Iron is poorly available to chelators. CH-type MGs contain much fewer metals. CP-type MGs have then been subjected to partial bleaching by hydrogen peroxide in ammonia, yielding a residual solid, called residual oxidized melanin (ROM) and a soluble but still pigmented fraction called melanin free acid (MFA). MFA can be isolated by precipitation at acidic pH. The (13)C-CPMAS NMR and EPR spectra of these derivatives indicated that ROM has a structure very similar to that of parent MGs, whereas MFA shows a decrease of the protein content with respect to the melanin and a decreased amount of bound iron. Thus, the oxidative degradation of CP-type MGs is a process not involving the bulk of MGs, but rather it proceeds from the solvent-exposed outer parts to the interior. Copyright (c) 2008 John Wiley & Sons, Ltd.

  7. Treatment of gingival pigmentation : A case series

    Directory of Open Access Journals (Sweden)

    Prasad Deepak

    2005-01-01

    Full Text Available A smile expresses a feeling of joy, success, sensuality, affection and courtesy, and reveals self confidence and kindness. The harmony of the smile is determined not only by the shape, the position and the color of the teeth but also by the gingival tissues. Gingival health and appearance are essential components of an attractive smile. Gingival pigmentation results from melanin granules, which are produced by melanoblasts. The degree of pigmentation depends on melanoblastic activity. Although melanin pigmentation of the gingiva is completely benign and does not present a medical problem, complaints of ′black gums′ are common particularly in patients having a very high smile line (gummy smile. For depigmentation of gingiva different treatment modalities have been reported like- Bur abrasion, scraping, partial thickness flap, cryotherapy, electrosurgery and laser. In the present case series bur abrasion, scraping, partial thickness flap (epithelial excision cryotherapy and electrosurgery have been tried for depigmentation, which are simple, effective and yield good results, along with good patient satisfaction. The problems encountered with some of these techniques have also been discussed.

  8. Treatment of gingival pigmentation: a case series.

    Science.gov (United States)

    Deepak, Prasad; Sunil, S; Mishra, R; Sheshadri

    2005-01-01

    A smile expresses a feeling of joy, success, sensuality, affection and courtesy, and reveals self confidence and kindness. The harmony of the smile is determined not only by the shape, the position and the color of the teeth but also by the gingival tissues. Gingival health and appearance are essential components of an attractive smile. Gingival pigmentation results from melanin granules, which are produced by melanoblasts. The degree of pigmentation depends on melanoblastic activity. Although melanin pigmentation of the gingiva is completely benign and does not present a medical problem, complaints of 'black gums' are common particularly in patients having a very high smile line (gummy smile). For depigmentation of gingiva different treatment modalities have been reported like- Bur abrasion, scraping, partial thickness flap, cryotherapy, electrosurgery and laser. In the present case series bur abrasion, scraping, partial thickness flap (epithelial excision) cryotherapy and electrosurgery have been tried for depigmentation, which are simple, effective and yield good results, along with good patient satisfaction. The problems encountered with some of these techniques have also been discussed.

  9. The red sport of 'Zaosu' pear and its red-striped pigmentation pattern are associated with demethylation of the PyMYB10 promoter.

    Science.gov (United States)

    Qian, Minjie; Sun, Yongwang; Allan, Andrew C; Teng, Yuanwen; Zhang, Dong

    2014-11-01

    'Zaosu' pear, a hybrid of Pyrus pyrifolia and Pyrus communis, is a popular cultivar developed in China. 'Zaosu Red' is a bud sport of 'Zaosu' with red shoots, young leaves, and fruit. After grafting of 'Zaosu Red', reverse mutations in some branches lead to a loss of colour in leaves and stems. Also, the mature fruit of 'Zaosu Red' exhibits two phenotypes; fully red and striped. The aim of this study was to establish the mechanism of the red colour mutation in 'Zaosu' and the striped pigmentation pattern in fruit of 'Zaosu Red'. The accumulation of anthocyanins and transcript levels of the genes PpUFGT2 and PyMYB10 were highly correlated. The open reading frames (ORF) and promoter regions of these two key genes were cloned and compared between 'Zaosu' and its bud sports, but no sequence differences were found. The R2R3 MYB, PyMYB10, can activate expression of genes encoding enzymes of the anthocyanin biosynthetic pathway. A yeast one-hybrid assay showed that PyMYB10 was associated with the -658 to -172bp fragment of the PpUFGT2 promoter, probably via a MYB binding site (MBS) located at -466bp. The PyMYB10 promoter had lower methylation levels in anthocyanin-rich tissues, indicating that the red bud sport of 'Zaosu' pear and the striped pigmentation pattern of 'Zaosu Red' pear are associated with demethylation of the PyMYB10 promoter. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Extraction and Identification of the Pigment in the Adductor Muscle Scar of Pacific Oyster Crassostrea gigas.

    Directory of Open Access Journals (Sweden)

    Shixin Hao

    Full Text Available In this study, UV (ultraviolet and IR (infrared radiation spectral analysis were integrated to identify the pigment in the adductor muscle scar of the Pacific oyster Crassostrea gigas. The pigment was extracted from the adductor muscle scars of cleaned oyster shells that were pulverized, hydrolyzed in hot hydrochloric acid, purified with diethyl ether, and dissolved in 0.01 mL/L NaOH. The maximum absorption of the pigment in the UV absorption spectrum within the range of 190-500 nm was observed between 210-220 nm. The UV absorbance decreased with increasing wavelength which was consistent with the UV spectral absorption characteristics of melanin. In addition, Fourier transform infrared spectroscopy scanning revealed characteristic absorption peaks that emerged near 3440 cm-1 and 1630 cm-1, which was consistent with infrared scanning features of eumelanin (a type of melanin. This study has demonstrated for the first time that the pigment in the adductor muscle scar of the Pacific oyster is melanin, hinting that the adductor muscle could be another organ pigmenting the mollusc shell with melanin other than mantle.

  11. Effects of altered catecholamine metabolism on pigmentation and physical properties of sclerotized regions in the silkworm melanism mutant.

    Directory of Open Access Journals (Sweden)

    Liang Qiao

    Full Text Available Catecholamine metabolism plays an important role in the determination of insect body color and cuticle sclerotization. To date, limited research has focused on these processes in silkworm. In the current study, we analyzed the interactions between catecholamines and melanin genes and their effects on the pigmentation patterns and physical properties of sclerotized regions in silkworm, using the melanic mutant melanism (mln silkworm strain as a model. Injection of β-alanine into mln mutant silkworm induced a change in catecholamine metabolism and turned its body color yellow. Further investigation of the catecholamine content and expression levels of the corresponding melanin genes from different developmental stages of Dazao-mln (mutant and Dazao (wild-type silkworm revealed that at the larval and adult stages, the expression patterns of melanin genes precipitated dopamine accumulation corresponding to functional loss of Bm-iAANAT, a repressive effect of excess NBAD on ebony, and upregulation of tan in the Dazao-mln strain. During the early pupal stage, dopamine did not accumulate in Dazao-mln, since upregulation of ebony and black genes led to conversion of high amounts of dopamine into NBAD, resulting in deep yellow cuticles. Scanning electron microscope analysis of a cross-section of adult dorsal plates from both wild-type and mutant silkworm disclosed the formation of different layers in Dazao-mln owing to lack of NADA, compared to even and dense layers in Dazao. Analysis of the mechanical properties of the anterior wings revealed higher storage modulus and lower loss tangent in Dazao-mln, which was closely associated with the altered catecholamine metabolism in the mutant strain. Based on these findings, we conclude that catecholamine metabolism is crucial for the color pattern and physical properties of cuticles in silkworm. Our results should provide a significant contribution to Lepidoptera cuticle tanning research.

  12. Plumage color patterns of an extinct dinosaur.

    Science.gov (United States)

    Li, Quanguo; Gao, Ke-Qin; Vinther, Jakob; Shawkey, Matthew D; Clarke, Julia A; D'Alba, Liliana; Meng, Qingjin; Briggs, Derek E G; Prum, Richard O

    2010-03-12

    For as long as dinosaurs have been known to exist, there has been speculation about their appearance. Fossil feathers can preserve the morphology of color-imparting melanosomes, which allow color patterns in feathered dinosaurs to be reconstructed. Here, we have mapped feather color patterns in a Late Jurassic basal paravian theropod dinosaur. Quantitative comparisons with melanosome shape and density in extant feathers indicate that the body was gray and dark and the face had rufous speckles. The crown was rufous, and the long limb feathers were white with distal black spangles. The evolution of melanin-based within-feather pigmentation patterns may coincide with that of elongate pennaceous feathers in the common ancestor of Maniraptora, before active powered flight. Feathers may thus have played a role in sexual selection or other communication.

  13. Uptake of 7,12-dimethylbenz(a)anthracene and benzo(a)pyrene in melanin-containing tissues

    Energy Technology Data Exchange (ETDEWEB)

    Roberto, A.; Larsson, B.S. [Uppsala Univ., Dept. of Pharmaceutical Biosciences, Div. of Toxicology, Uppsala (Sweden); Tjaelve, H. [The Swedish Univ. of Agricultural Sciences, Dept. of Pharmacology and Toxicology, Uppsala (Sweden)

    1996-08-01

    It is widely accepted that UV exposure is the main etiological factor for malignant melanoma. Epidemiologic studies, however, have indicated that also chemical carcinogens may be a risk factor for the disease. Polycyclic aromatic hydrocarbons such as 7,12-dimethylbenz(a)anthracene and benzo(a)pyrene represent an important class of carcinogenic chemicals. It is known that 7,12-dimethylbenz(a)anthracene can induce melanotic tumours in various animal species, and human melanocytes in culture have been found to be capable of metabolizing benzo(a)pyrene to its proximate carcinogen benzo(a)pyrene-7,8-diol. In the present study the disposition of {sup 14}C- and {sup 3}H-7,12-dimethylbenz(a)anthracene and {sup 14}C-benzo(a)pyrene was studied in pigmented and albino mice and Syrian golden hamsters by whole-body autoradiography. The results showed pronounced retention of label in the melanin-containing structures of the eyes and the hair follicles in the pigmented animals. The labelling of the corresponding structures in the albino animals was low. Additional experiments showed that 7,12-dimethylbenz(a)anthracene and benzo(a)pyrene as well as some of their metabolites are bound to melanin in vitro. The specific localization of the polycyclic aromatic hydrocarbons in pigmented tissues due to melanin affinity, combined with bioactivating capacity of melanocytes, suggest that these substances may play a role in the induction of malignant melanoma. (au).

  14. Skip areas of retained melanin: A clue to the histopathological diagnosis of idiopathic guttate hypomelanosis

    Directory of Open Access Journals (Sweden)

    Rajiv Joshi

    2014-01-01

    Full Text Available Biopsy findings in 55 cases of idiopathic guttate hypomelanosis (IGH are reported. Most cases had a flat epidermis with loss of the rete pattern and a thickened orthokeratotic basket weave stratum corneum. The epidermis had markedly decreased to absent melanin in the basal layer and reduced numbers of melanocytes at the dermoepidermal junction. One-third of patients had a sparse perivascular lymphocytic infiltrate, whereas the rest had no significant dermal inflammation. These findings are in concordance with current literature.However, small foci of retained melanin in the basal layer (skip areas alternating with larger areas of melanin loss were present in almost 80% of cases. This finding has not been reported earlier and appears to be quite specific to IGH and may be used as a clue to differentiate IGH from other similar conditions such as vitiligo and guttate morphea.

  15. Thermohydrogel Containing Melanin for Photothermal Cancer Therapy.

    Science.gov (United States)

    Kim, Miri; Kim, Hyun Soo; Kim, Min Ah; Ryu, Hyanghwa; Jeong, Hwan-Jeong; Lee, Chang-Moon

    2016-12-01

    Melanin is an effective absorber of light and can extend to near infrared (NIR) regions. In this study, a natural melanin is presented as a photothermal therapeutic agent (PTA) because it provides a good photothermal conversion efficiency, shows biodegradability, and does not induce long-term toxicity during retention in vivo. Poloxamer solution containing melanin (Pol-Mel) does not show any precipitation and shows sol-gel transition at body temperature. After irradiation from 808 nm NIR laser at 1.5 W cm(-2) for 3 min, the photothermal conversion efficiency of Pol-Mel is enough to kill cancer cells in vitro and in vivo. The tumor growth of mice bearing CT26 tumors treated with Pol-Mel injection and laser irradiation is suppressed completely without recurrence postirradiation. All these results indicate that Pol-Mel can become an attractive PTA for photothermal cancer therapy.

  16. The contribution of structural-, psittacofulvin- and melanin-based colouration to sexual dichromatism in Australasian parrots.

    Science.gov (United States)

    Taysom, A J; Stuart-Fox, D; Cardoso, G C

    2011-02-01

    Colour ornamentation in animals is exceptionally diverse, but some colours may provide better signals of individual quality or more efficient visual stimuli and, thus, be more often used as sexual signals. This may depend on physiological costs, which depend on the mechanism of colour production (e.g. exogenously acquired colouration in passerine birds appears to be most sexually dichromatic). We studied sexual dichromatism in a sample of 27 Australasian parrot species with pigment- (melanin and psittacofulvin) and structural-based colouration, to test whether some of these types of colouration are more prominent in sexual ornamentation. Unlike passerines, in which long wavelength colouration (yellow to red) usually involves exogenous and costly carotenoid pigments, yellow to red colouration in parrots is based on endogenously synthesized psittacofulvin pigments. This allows us to assess whether costly exogenous pigments are necessary for these plumage colours to have a prominent role in sexual signalling. Structural blue colouration showed the largest and most consistent sexual dichromatism, both in area and perceptually relevant chromatic differences, indicating that it is often ornamental in parrots. By contrast, we found little evidence for consistent sexual dichromatism in melanin-based colouration. Unlike passerines, yellow to red colouration was not strongly sexually dichromatic: although the area of colouration was generally larger in males, colour differences between the sexes were on average imperceptible to parrots. This is consistent with the idea that the prominent yellow to red sexual dichromatism in passerines is related to the use of carotenoid pigments, rather than resulting from sensory bias for these colours.

  17. Research progress of bacterial melanin and nervous system diseases%细菌黑色素与神经系统疾病的研究进展

    Institute of Scientific and Technical Information of China (English)

    杨倩; 韩彦青; 姜晓萌; 裴宇恒; 李东芳; 李光来

    2016-01-01

    黑色素是广泛存在于自然界中的一类天然色素家族,苏云金芽孢杆菌突变株可获得高水平细菌黑色素,细菌黑色素能透过血脑屏障,具有抗氧化、螯合有毒金属、促进神经再生等生物学特性,可用来治疗某些与黑色素缺乏相关的神经性疾病,也能促进中枢神经系统及周围神经损伤后的结构和功能的恢复,文章就细菌黑色素在神经系统疾病的相关研究做了综述。%Melanin is a class of natural pigments family in nature. Bacterial melanin with high level of pigment synthesis-Bacillus thuringiensis was obtained. Bacterial melanin can cross the blood-brain barrier, accomplish antioxidant protection, chelate toxic metals, promote nerve regeneration. It can treat nervous system diseases with melanin deficiency, promote the structural and functional recovery of the central nervous system and peripheral nerve injury. This article summarized the research of the function of the bacterial melanin in the nervous system diseases.

  18. Comparison of the effectiveness between 2% and 4% nicotinamide gel in reducing melanin index

    OpenAIRE

    Lisa Murtisari, Lisa Murtisari

    2015-01-01

    Background: Nicotinamide is a safe agent inhibiting melanosome transfer in vitro therefore it can reduce skin pigmentation. Two percent nicotinamide cream combined with sunscreen as a lightening agent in-creases skin lightness in vivo. Measurement of skin colour changes can be performed by mexameter to measure melanin index (MI).Objective: This study was aimed to compare the effectiveness of 2% and 4% nicotinamide gel as a lightening agent in reducing MI.Materials and Methods: This study was ...

  19. Comparison of the effectiveness between 2% and 4% nicotinamide gel in reducing melanin index

    OpenAIRE

    Lisa Murtisari, Lisa Murtisari

    2015-01-01

    Background: Nicotinamide is a safe agent inhibiting melanosome transfer in vitro therefore it can reduce skin pigmentation. Two percent nicotinamide cream combined with sunscreen as a lightening agent in-creases skin lightness in vivo. Measurement of skin colour changes can be performed by mexameter to measure melanin index (MI).Objective: This study was aimed to compare the effectiveness of 2% and 4% nicotinamide gel as a lightening agent in reducing MI.Materials and Methods: This study was ...

  20. Polymeric peptide pigments with sequence-encoded properties

    Energy Technology Data Exchange (ETDEWEB)

    Lampel, Ayala; McPhee, Scott A.; Park, Hang-Ah; Scott, Gary G.; Humagain, Sunita; Hekstra, Doeke R.; Yoo, Barney; Frederix, Pim W. J. M.; Li, Tai-De; Abzalimov, Rinat R.; Greenbaum, Steven G.; Tuttle, Tell; Hu, Chunhua; Bettinger, Christopher J.; Ulijn, Rein V.

    2017-06-08

    Melanins are a family of heterogeneous polymeric pigments that provide ultraviolet (UV) light protection, structural support, coloration, and free radical scavenging. Formed by oxidative oligomerization of catecholic small molecules, the physical properties of melanins are influenced by covalent and noncovalent disorder. We report the use of tyrosine-containing tripeptides as tunable precursors for polymeric pigments. In these structures, phenols are presented in a (supra-)molecular context dictated by the positions of the amino acids in the peptide sequence. Oxidative polymerization can be tuned in a sequence-dependent manner, resulting in peptide sequence–encoded properties such as UV absorbance, morphology, coloration, and electrochemical properties over a considerable range. Short peptides have low barriers to application and can be easily scaled, suggesting near-term applications in cosmetics and biomedicine.

  1. Community analysis of pigment patterns from 37 microalgae strains reveals new carotenoids and porphyrins characteristic of distinct strains and taxonomic groups

    Science.gov (United States)

    Bérard, Jean-Baptiste; Kaas, Raymond; Pasquet, Virginie; Picot, Laurent; Cadoret, Jean-Paul

    2017-01-01

    Phytoplankton, with an estimated 30 000 to 1 000 000 species clustered in 12 phyla, presents a high taxonomic and ecophysiological diversity, reflected by the complex distribution of pigments among the different algal classes. High performance liquid chromatography is the gold standard method for qualitative and quantitative analysis of phytoplankton pigments in seawater and culture samples, but only a few pigments can be used as robust chemotaxonomic markers. A major challenge is thus to identify new ones, characteristic of a strain, species, class or taxon that cannot be currently identified on the basis of its pigment signature. Using an optimized extraction process coupled to a HPLC de-replication strategy, we examined the pigment composition of 37 microalgae strains, representative of the broad taxonomic diversity of marine and freshwater species (excluding cyanobacteria). For each species, the major pigments already described were unambiguously identified. We also observed the presence of several minor unidentified pigments in each chromatogram. The global analysis of pigment compositions revealed a total of 124 pigments, including 98 pigments or derivatives unidentified using the standards. Absorption spectra indicated that 35 corresponded to chlorophyll/porphyrin derivatives, 57 to carotenoids and six to derivatives having both spectral signatures. Sixty-one of these unidentified or new carotenoids and porphyrin derivatives were characteristic of particular strains or species, indicating their possible use as highly specific chemotaxonomic markers capable of identifying one strain out of the 37 selected. We developed a graphical analysis using Gephi software to give a clear representation of pigment communities among the various phytoplankton strains, and to reveal strain-characteristic and shared pigments. This made it possible to reconstruct the taxonomic evolution of microalgae classes, on the basis of the conservation, loss, and/or appearance of

  2. Brook trout (Salvelinus fontinalis extinction in small boreal lakes revealed by ephippia pigmentation: a preliminary analysis

    Directory of Open Access Journals (Sweden)

    Alexandre Bérubé Tellier

    2016-12-01

    Full Text Available Ephippium pigmentation is a plastic trait which can be related to a trade-off between visual predation pressure and better protection of cladoceran eggs against different types of stress. Experimental studies showed that planktivorous fish exert a greater predation pressure on individuals carrying darker ephippia, but little is known about the variation of ephippium pigmentation along gradients of fish predation pressure in natural conditions. For this study, our experimental design included four small boreal lakes with known fish assemblages. Two of the lakes have viable brook trout (Salvelinus fontinalis populations, whereas the other two lakes experienced brook trout extinctions during the 20th century. Cladoceran ephippia were extracted from sediment cores at layers corresponding to the documented post- extinction phase (1990's and from an older layer (1950's for which the brook trout population status is not known precisely. Our first objective was to determine whether brook trout extinction has a direct effect on both ephippium pigmentation and size. Our second objective was to give a preliminary assessment of the status of brook trout populations in the 1950's by comparing the variation in ephippia traits measured from this layer to those measured in the 1990's, for which the extinction patterns are well known. Cost-effective image analysis was used to assess variation in pigmentation levels in ephippia. This approach provided a proxy for the amount of melanin invested in each ephippium analysed. Our study clearly shows that ephippium pigmentation may represent a better indicator of the presence of fish predators than ephippium size, a trait that showed a less clear pattern of variation between lakes with and without fish. For the 1990's period, ephippia from fishless lakes were darker and showed a slight tendency to be larger than ephippia from lakes with brook trout. However, no clear differences in either ephippium size or pigmentation

  3. Estimation of molar absorptivities and pigment sizes for eumelanin and pheomelanin using femtosecond transient absorption spectroscopy

    Science.gov (United States)

    Piletic, Ivan R.; Matthews, Thomas E.; Warren, Warren S.

    2009-11-01

    Fundamental optical and structural properties of melanins are not well understood due to their poor solubility characteristics and the chemical disorder present during biomolecular synthesis. We apply nonlinear transient absorption spectroscopy to quantify molar absorptivities for eumelanin and pheomelanin and thereby get an estimate for their average pigment sizes. We determine that pheomelanin exhibits a larger molar absorptivity at near IR wavelengths (750nm), which may be extended to shorter wavelengths. Using the molar absorptivities, we estimate that melanin pigments contain ˜46 and 28 monomer units for eumelanin and pheomelanin, respectively. This is considerably larger than the oligomeric species that have been recently proposed to account for the absorption spectrum of eumelanin and illustrates that larger pigments comprise a significant fraction of the pigment distribution.

  4. Low-melanin containing pullulan production from sugarcane bagasse hydrolysate by Aureobasidium pullulans in fermentations assisted by light-emitting diode.

    Science.gov (United States)

    Terán Hilares, Ruly; Orsi, Camila Ayres; Ahmed, Muhammad Ajaz; Marcelino, Paulo Franco; Menegatti, Carlos Renato; da Silva, Silvio Silvério; Dos Santos, Júlio César

    2017-04-01

    Pullulan is a polymer produced by Aureobasidium pullulans and the main bottleneck for its industrial production is the presence of melanin pigment. In this study, light-emitting diodes (LEDs) of different wavelengths were used to assist the fermentation process aiming to produce low-melanin containing pullulan by wild strain of A. pullulans LB83 with different carbon sources. Under white light using glucose-based medium, 11.75g.L(-1) of pullulan with high melanin content (45.70UA540nm.g(-1)) was obtained, this production improved in process assisted by blue LED light, that resulted in 15.77g.L(-1) of pullulan with reduced content of melanin (4.46UA540nm.g(-1)). By using sugarcane bagasse (SCB) hydrolysate as carbon source, similar concentration of pullulan (about 20g.L(-1)) was achieved using white and blue LED lights, with lower melanin contents in last. Use of LED light was found as a promising approach to assist biotechnological process for low-melanin containing pullulan production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Melanin index in assessing the treatment efficacy of 1064 nm Q switched Nd-Yag laser in nevus of Ota

    Directory of Open Access Journals (Sweden)

    Gomathy Sethuraman

    2013-01-01

    Full Text Available Background: Q-switched neodymium-yttrium aluminium-garnet (Q switched Nd-Yag laser has been used in the treatment of nevus of Ota in all skin types with variable success rate. Data with an objective assessment parameter to this laser treatment is lacking. Objective: To evaluate the utility of melanin index in assessing the treatment response and also determine the efficacy and safety of the Q-switched Nd-Yag laser (1064-nm in the treatment of nevus of Ota in Fitzpatrick skin types IV and V. Materials and Methods: A total of 35 patients treated with Nd-Yag laser were studied. The objective improvement (pigment clearance was determined by melanin index from two fixed points: A1, 2 cm below the pupil at the mid pupillary line (when the gaze is fixed; A2, the most prominent part of zygoma. The melanin index in these two areas was recorded as M1 and M2, respectively. The subjective clinical improvement was determined by the physician and the patient global assessment score. Results: The mean baseline melanin indices M1 and M2 were 59.54 ± 9.72 and 59.02 ± 9.16, respectively. At the last visit the mean M1 and M2 decreased to 53.8 ± 8.55 (P 50% pigment clearance. Conclusion: The melanin index, a simple non-invasive parameter is useful in assessing the treatment response more objectively. The 1064-nm Q-switched Nd-Yag laser offers good improvement in patients with nevus of Ota in darker skin types IV/V.

  6. Melanin Index in Assessing the Treatment Efficacy of 1064 nm Q Switched Nd-Yag Laser in Nevus of Ota

    Science.gov (United States)

    Sethuraman, Gomathy; Sharma, Vinod K; Sreenivas, Vishnubhatla

    2013-01-01

    Background: Q-switched neodymium-yttrium aluminium-garnet (Q switched Nd-Yag) laser has been used in the treatment of nevus of Ota in all skin types with variable success rate. Data with an objective assessment parameter to this laser treatment is lacking. Objective: To evaluate the utility of melanin index in assessing the treatment response and also determine the efficacy and safety of the Q-switched Nd-Yag laser (1064-nm) in the treatment of nevus of Ota in Fitzpatrick skin types IV and V. Materials and Methods: A total of 35 patients treated with Nd-Yag laser were studied. The objective improvement (pigment clearance) was determined by melanin index from two fixed points: A1, 2 cm below the pupil at the mid pupillary line (when the gaze is fixed); A2, the most prominent part of zygoma. The melanin index in these two areas was recorded as M1 and M2, respectively. The subjective clinical improvement was determined by the physician and the patient global assessment score. Results: The mean baseline melanin indices M1 and M2 were 59.54 ± 9.72 and 59.02 ± 9.16, respectively. At the last visit the mean M1 and M2 decreased to 53.8 ± 8.55 (P 50% pigment clearance. Conclusion: The melanin index, a simple non-invasive parameter is useful in assessing the treatment response more objectively. The 1064-nm Q-switched Nd-Yag laser offers good improvement in patients with nevus of Ota in darker skin types IV/V. PMID:24470713

  7. Use of multiphoton tomography and fluorescence lifetime imaging to investigate skin pigmentation in vivo

    Science.gov (United States)

    Dancik, Yuri; Favre, Amandine; Loy, Chong Jin; Zvyagin, Andrei V.; Roberts, Michael S.

    2013-02-01

    There is a growing body of literature showing the usefulness of multiphoton tomography (MPT) and fluorescence lifetime imaging for in situ characterization of skin constituents and the ensuing development of noninvasive diagnostic tools against skin diseases. Melanin and pigmentation-associated skin cancers constitute some of the major applications. We show that MPT and fluorescence lifetime imaging can be used to measure changes in cutaneous melanin concentration and that these can be related to the visible skin color. Melanin in the skin of African, Indian, Caucasian, and Asian volunteers is detected on the basis of its emission wavelength and fluorescence lifetimes in solution and in a melanocyte-keratinocyte cell culture. Fluorescence intensity is used to characterize the melanin content and distribution as a function of skin type and depth into the skin (stratum granulosum and stratum basale). The measured fluorescence intensities in given skin types agree with melanin amounts reported by others using biopsies. Our results suggest that spatial distribution of melanin in skin can be studied using MPT and fluorescence lifetime imaging, but further studies are needed to ascertain that the method can resolve melanin amount in smaller depth intervals.

  8. Melanin as an active layer in biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Piacenti da Silva, Marina, E-mail: marinaness@yahoo.com; Congiu, Mirko, E-mail: congiumat@gmail.com; Oliveira Graeff, Carlos Frederico de, E-mail: graeff@fc.unesp.br [Department of Physics, Faculty of Sciences - UNESP, Bauru, SP (Brazil); Fernandes, Jéssica Colnaghi, E-mail: jeziga-cf@yahoo.com.br; Biziak de Figueiredo, Natália, E-mail: natbiziak@yahoo.com.br; Mulato, Marcelo, E-mail: mmulato@ffclrp.usp.br [Department of Physics, Faculty of Philosophy, Science and Letters at Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP (Brazil)

    2014-03-15

    The development of pH sensors is of great interest due to its extensive application in several areas such as industrial processes, biochemistry and particularly medical diagnostics. In this study, the pH sensing properties of an extended gate field effect transistor (EGFET) based on melanin thin films as active layer are investigated and the physical mechanisms related to the device operation are discussed. Thin films were produced from different melanin precursors on indium tin oxide (ITO) and gold substrates and were investigated by Atomic Force Microscopy and Electrochemical Impedance Spectroscopy. Experiments were performed in the pH range from 2 to 12. EGFETs with melanin deposited on ITO and on gold substrates showed sensitivities ranging from 31.3 mV/pH to 48.9 mV/pH, depending on the melanin precursor and the substrate used. The pH detection is associated with specific binding sites in its structure, hydroxyl groups and quinone imine.

  9. Melanin biosynthesis pathway in Agaricus bisporus mushrooms

    NARCIS (Netherlands)

    Weijn, A.; Bastiaan-Net, S.; Wichers, H.J.; Mes, J.J.

    2013-01-01

    With the full genome sequence of Agaricus bisporus available, it was possible to investigate the genes involved in the melanin biosynthesis pathway of button mushrooms. Based on different BLAST and alignments, genes were identified in the genome which are postulated to be involved in this pathway.

  10. Melanin as an active layer in biosensors

    Directory of Open Access Journals (Sweden)

    Marina Piacenti da Silva

    2014-03-01

    Full Text Available The development of pH sensors is of great interest due to its extensive application in several areas such as industrial processes, biochemistry and particularly medical diagnostics. In this study, the pH sensing properties of an extended gate field effect transistor (EGFET based on melanin thin films as active layer are investigated and the physical mechanisms related to the device operation are discussed. Thin films were produced from different melanin precursors on indium tin oxide (ITO and gold substrates and were investigated by Atomic Force Microscopy and Electrochemical Impedance Spectroscopy. Experiments were performed in the pH range from 2 to 12. EGFETs with melanin deposited on ITO and on gold substrates showed sensitivities ranging from 31.3 mV/pH to 48.9 mV/pH, depending on the melanin precursor and the substrate used. The pH detection is associated with specific binding sites in its structure, hydroxyl groups and quinone imine.

  11. Melanin as an active layer in biosensors

    Science.gov (United States)

    Piacenti da Silva, Marina; Fernandes, Jéssica Colnaghi; de Figueiredo, Natália Biziak; Congiu, Mirko; Mulato, Marcelo; de Oliveira Graeff, Carlos Frederico

    2014-03-01

    The development of pH sensors is of great interest due to its extensive application in several areas such as industrial processes, biochemistry and particularly medical diagnostics. In this study, the pH sensing properties of an extended gate field effect transistor (EGFET) based on melanin thin films as active layer are investigated and the physical mechanisms related to the device operation are discussed. Thin films were produced from different melanin precursors on indium tin oxide (ITO) and gold substrates and were investigated by Atomic Force Microscopy and Electrochemical Impedance Spectroscopy. Experiments were performed in the pH range from 2 to 12. EGFETs with melanin deposited on ITO and on gold substrates showed sensitivities ranging from 31.3 mV/pH to 48.9 mV/pH, depending on the melanin precursor and the substrate used. The pH detection is associated with specific binding sites in its structure, hydroxyl groups and quinone imine.

  12. Substantial Effect of Melanin Influencing Factors on Melanogenesis in Muzzle Melanocytes of Differently Colored Hanwoo

    Directory of Open Access Journals (Sweden)

    Touseef Amna

    2012-07-01

    Full Text Available The present study was designed to investigate the effect of α-melanocyte-stimulating hormone (α-MSH, nitric oxide (NO and L-cysteine on melanin production and expression of related genes MC1R, Tyr, Tyrp-1 and Tyrp-2 in muzzle melanocytes of differently colored three native Hanwoo cattle. Muzzle samples were taken from black, brindle and brown Hanwoo and purified melanocytes were cultured with α-MSH, nitric oxide and L-cysteine at 100 nM, 50 µM and 0.07 mg/ml of media respectively. The amounts of total melanin, eumelanin and mRNA expression at Tyr, Tyrp-1, Tyrp-2 and MC1R levels were quantified. α-MSH and nitric oxide significantly increased (p<0.05 the amount of total melanin in black and brindle whereas eumelanin production in brown Hanwoo muzzle melanocytes. On the contrary, L-cysteine greatly (p<0.05 depressed the eumelanin production in black color but increased in brown. Simultaneously, up regulation of Tyr by nitric oxide and α-MSH and down regulation of Tyr, Tyrp-2 and MC1R genes by L-cysteine were observed in muzzle melanocytes of all three phenotypes. The results of this study revealed nitric oxide and α-MSH contribute hyper-pigmentation by enhancing eumelanogenesis whereas L-cysteine contributes to pheomelanin production in different colored Hanwoo muzzle melanocytes.

  13. Seeking carotenoid pigments in amber-preserved fossil feathers

    Science.gov (United States)

    Thomas, Daniel B.; Nascimbene, Paul C.; Dove, Carla J.; Grimaldi, David A.; James, Helen F.

    2014-06-01

    Plumage colours bestowed by carotenoid pigments can be important for visual communication and likely have a long evolutionary history within Aves. Discovering plumage carotenoids in fossil feathers could provide insight into the ecology of ancient birds and non-avian dinosaurs. With reference to a modern feather, we sought chemical evidence of carotenoids in six feathers preserved in amber (Miocene to mid-Cretaceous) and in a feather preserved as a compression fossil (Eocene). Evidence of melanin pigmentation and microstructure preservation was evaluated with scanning electron and light microscopies. We observed fine microstructural details including evidence for melanin pigmentation in the amber and compression fossils, but Raman spectral bands did not confirm the presence of carotenoids in them. Carotenoids may have been originally absent from these feathers or the pigments may have degraded during burial; the preservation of microstructure may suggest the former. Significantly, we show that carotenoid plumage pigments can be detected without sample destruction through an amber matrix using confocal Raman spectroscopy.

  14. Bacterial melanin promotes recovery after sciatic nerve injury in rats

    Institute of Scientific and Technical Information of China (English)

    Olga V Gevorkyan; Irina B Meliksetyan; Tigran R Petrosyan; Anichka S Hovsepyan

    2015-01-01

    Bacterial melanin, obtained from the mutant strain ofBacillus Thuringiensis, has been shown to promote recovery after central nervous system injury. It is hypothesized, in this study, that bacterial melanin can promote structural and functional recovery after peripheral nerve injury. Rats subjected to sciatic nerve transection were intramuscularly administered bacterial melanin. The sciatic nerve transected rats that did not receive intramuscular administration of bacterial melanin served as controls. Behavior tests showed that compared to control rats, the time taken for instrumental conditioned relfex recovery was signiifcantly shorter and the ability to keep the balance on the rotating bar was signiifcantly better in bacterial melanin-treated rats. Histomor-phological tests showed that bacterial melanin promoted axon regeneration after sciatic nerve injury. These ifndings suggest that bacterial melanin exhibits neuroprotective effects on injured sciatic nerve, contributes to limb motor function recovery, and therefore can be used for rehabil-itation treatment of peripheral nerve injury.

  15. Two-photon absorption and transient photothermal imaging of pigments in tissues

    Science.gov (United States)

    Ye, Tong; Fu, Dan; Matthews, Thomas E.; Hong, Lian; Simon, John D.; Warren, Warren S.

    2008-02-01

    As a main pigment in skin tissues, melanin plays an important role in photo-protecting skin from UV radiation. However, melanogenesis may be altered due to disease or environmental factors; for example, sun exposure may cause damage and mutation of melanocytes and induce melanoma. Imaging pigmentation changes may provide invaluable information to catch the malignant transformation in its early stage and in turn improve the prognosis of patients. We have demonstrated previously that transmission mode, two-photon, one- or two-color absorption microscopy could provide remarkable contrast in imaging melanin in skin. In this report we demonstrate significantly improved sensitivity, so that we are now able to image in epi-mode (or back reflection) in two-photon absorption. This improvement makes possible for us to characterize the different types of pigmentation on the skin in vivo at virtually any location. Another finding is that we can also image transient photothermal dynamics due to the light absorption of melanin. By carefully choosing excitation and probe wavelengths, we might be able to image melanin in different structures under different micro-environments in skin, which could provide useful photochemical and photophysical insights in understanding how pigments are involved in photoprotection and photodamage of cells.

  16. Morpho-histology of head kidney of female catfish Heteropneustes fossilis: seasonal variations in melano-macrophage centers, melanin contents and effects of lipopolysaccharide and dexamethasone on melanins.

    Science.gov (United States)

    Kumar, Ravi; Joy, K P; Singh, S M

    2016-10-01

    In the catfish Heteropneustes fossilis, the anterior kidney is a hemopoietic tissue which surrounds the adrenal homologues, interrenal (IR) and chromaffin tissues corresponding to the adrenal cortical and adrenal medulla of higher mammals. The IR tissue is arranged in cell cords around the posterior cardinal vein (PCV) and its tributaries and secretes corticosteroids. The chromaffin tissue is scattered singly or in nests of one or more cells around the epithelial lining of the PCV or blood capillaries within the IR tissue. They are ferric ferricyanide-positive. Leukemia-inhibitory factor (LIF)-like reactivity was noticed in the lining of the epithelium of the IR cell cords and around the wall of the PCV and blood capillaries. No staining was observed in the hemopoietic cells. IL-1β- and TNF-α-like immunoreactivity was seen in certain cells in the hemopoietic tissue but not in the IR region. Macrophages were identified with mammalian macrophage-specific MAC387 antibodies and are present in the hemopoietic mass but not in the IR tissue. Pigments accumulate in the hemopoietic mass as melano-macrophage centers (MMCs) and are PAS-, Schmorl's- and Perls'-positive. The pigments contain melanin (black), hemosiderin (blue) and lipofuscin/ceroid (oxidized lipid, yellowish tan), as evident from the Perls' reaction. The MMCs were TUNEL-positive as evident from FITC fluorescence, indicating their apoptotic nature. The MMCs showed significant seasonal variation with their density increasing to the peak in the postspawning phase. Melanins were characterized spectrophotometrically for the first time in fish anterior kidney. The predominant form is pheomelanin (PM), followed by eumelanin (EM) and alkali-soluble melanin (ASM). Melanins showed significant seasonal variations with the level low in the resting phase and increasing to the peak in the postspawning phase. Under in vitro conditions, lipopolysaccharide (10 µg/mL) treatment increased significantly the levels of PM and EM

  17. Microneedling dilates the follicular infundibulum and increases transfollicular absorption of liposomal sepia melanin

    Science.gov (United States)

    Serrano, Gabriel; Almudéver, Patricia; Serrano, Juan M; Cortijo, Julio; Faus, Carmen; Reyes, Magda; Expósito, Inmaculada; Torrens, Ana; Millán, Fernando

    2015-01-01

    Encapsulation of chemicals in liposomes and microneedling are currently used techniques to enhance the penetration of several substances through skin and hair. In this study, we apply a liposomal melanin–fluorescein compound to an ex vivo model of human skin, using a new electrical microneedling device (Nanopore turbo roller). The product was applied by hand massage (A) or with the assistance of the electrical roller for 2 minutes (B). An additional test was performed free of product and with only the E-roller (C). Histological changes and product absorption were evaluated by optical and fluorescent microscopy 60 and 90 minutes after the treatment. Site B showed larger deposits of melanin–fluorescein at superficial and deep levels of hair structures in comparison to site A. Light, epidermal deposits of the melanin–fluorescein complex were also observed. Sites B and C showed a significant widening (47%) of the follicular infundibulum which could explain the increased penetration of the formulation. Microneedling also removed the scales and sebum residues in the neighborhood of the infundibulum. Targeting hair follicles with melanin may be useful to dye poorly pigmented hairs, improving laser hair removal. The procedure accelerates the delivery of melanin into hair structures allowing an even absorption, larger pigment deposits, and deeper penetration of the formulation into the hair. PMID:26170707

  18. Microneedling dilates the follicular infundibulum and increases transfollicular absorption of liposomal sepia melanin

    Directory of Open Access Journals (Sweden)

    Serrano G

    2015-06-01

    Full Text Available Gabriel Serrano,1 Patricia Almudéver,2 Juan M Serrano,3 Julio Cortijo,2 Carmen Faus,1 Magda Reyes,1 Inmaculada Expósito,3 Ana Torrens,3 Fernando Millán1 1Clínica Dermatológica Serrano, 2Department of Pharmacology, University of Valencia, 3Research and Development Department, Sesderma Laboratories, Valencia, Spain Abstract: Encapsulation of chemicals in liposomes and microneedling are currently used techniques to enhance the penetration of several substances through skin and hair. In this study, we apply a liposomal melanin–fluorescein compound to an ex vivo model of human skin, using a new electrical microneedling device (Nanopore turbo roller. The product was applied by hand massage (A or with the assistance of the electrical roller for 2 minutes (B. An additional test was performed free of product and with only the E-roller (C. Histological changes and product absorption were evaluated by optical and fluorescent microscopy 60 and 90 minutes after the treatment. Site B showed larger deposits of melanin–fluorescein at superficial and deep levels of hair structures in comparison to site A. Light, epidermal deposits of the melanin–fluorescein complex were also observed. Sites B and C showed a significant widening (47% of the follicular infundibulum which could explain the increased penetration of the formulation. Microneedling also removed the scales and sebum residues in the neighborhood of the infundibulum. Targeting hair follicles with melanin may be useful to dye poorly pigmented hairs, improving laser hair removal. The procedure accelerates the delivery of melanin into hair structures allowing an even absorption, larger pigment deposits, and deeper penetration of the formulation into the hair. Keywords: liposomes, melanin, microneedling, follicular infundibulum, hair removal

  19. Silver nanoparticles mediated altered gene expression of melanin biosynthesis genes in Bipolaris sorokiniana.

    Science.gov (United States)

    Mishra, Sandhya; Singh, H B

    2015-03-01

    Melanin production in many fungal phytopathogens has been investigated to play direct or indirect role in pathogenesis. However, in Bipolaris sorokiniana, the spot blotch pathogen of wheat, much less is known about the role melanin play in pathogenesis. As an extension of our previous report, the present study aims to investigate the plausible association between melanin production and virulence factor in B. sorokiniana. In the previous study, we carried out analysis on the antifungal efficacy of biosynthesized silver nanoparticles (AgNPs) against B. sorokiniana. The present investigation revealed the gene expression analysis of melanin biosynthesis genes viz. polyketide synthase (PKS1) and scytalone dehydratase (SCD1) under the influence of AgNPs. The 0.05mg/ml concentration of AgNPs yielded noticeable inhibition of B. sorokiniana growth, while 0.1mg/ml concentration of AgNPs accounted for complete inhibition of pathogen growth. In addition, the semiquantitative RT-PCR analysis exhibited reduced expression of PKS1 and SCD1 under the influence of AgNPs treatment. Furthermore, the qRT-PCR demonstrated 6.47 and 1.808 fold significant decrease in the expression pattern of PKS1 and SCD1, respectively, in B. sorokiniana treated with AgNPs. The present study provides probable understanding of molecular events underlying the antifungal role of AgNPs against B. sorokiniana.

  20. Monascus pigments.

    Science.gov (United States)

    Feng, Yanli; Shao, Yanchun; Chen, Fusheng

    2012-12-01

    Monascus pigments (MPs) as natural food colorants have been widely utilized in food industries in the world, especially in China and Japan. Moreover, MPs possess a range of biological activities, such as anti-mutagenic and anticancer properties, antimicrobial activities, potential anti-obesity activities, and so on. So, in the past two decades, more and more attention has been paid to MPs. Up to now, more than 50 MPs have been identified and studied. However, there have been some reviews about red fermented rice and the secondary metabolites produced by Monascus, but no monograph or review of MPs has been published. This review covers the categories and structures, biosynthetic pathway, production, properties, detection methods, functions, and molecular biology of MPs.

  1. Biochemical degradation of soil humic acids and fungal melanins

    Energy Technology Data Exchange (ETDEWEB)

    Zavgorodnyaya, Y.A.; Demin, V.V.; Kurakov, A.V. [Moscow MV Lomonosov State University, Moscow (Russian Federation). Dept. of Soil Science

    2002-07-01

    Studies were conducted to compare properties and biodegradation of fungal melanins from Aspergillus niger and Cladosporium cladosporiodes with those of humic acids from soils and brown coal. Compared to the humic acids the fungal melanins contained more functional groups, were less hydrophilic and had relatively high molecular weights. Under the conditions of incubation the melanins were found to be more readily degradable than the humic acids studied. The changes in elemental composition, optical parameters and the decrease of molecular weight, observed for both fungal melanins during degradation, made them more similar to soil humic acids.

  2. Dopamine-melanin nanofilms for biomimetic structural coloration.

    Science.gov (United States)

    Wu, Tong-Fei; Hong, Jong-Dal

    2015-02-09

    This article describes the formation of dopamine-melanin thin films (50-200 nm thick) at an air/dopamine solution interface under static conditions. Beneath these films, spherical melanin granules formed in bulk liquid phase. The thickness of dopamine-melanin films at the interface relied mainly on the concentration of dopamine solution and the reaction time. A plausible mechanism underlining dopamine-melanin thin film formation was proposed based on the hydrophobicity of dopamine-melanin aggregates and the mass transport of the aggregates to the air/solution interface as a result of convective flow. The thickness of the interfacial films increased linearly with the dopamine concentration and the reaction time. The dopamine-melanin thin film and granules (formed in bulk liquid phase) with a double-layered structure were transferred onto a solid substrate to mimic the (keratin layer)/(melanin granules) structure present in bird plumage, thereby preparing full dopamine-melanin thin-film reflectors. The reflected color of the thin-film reflectors depended on the film thickness, which could be adjusted according to the dopamine concentration. The reflectance of the resulted reflectors exhibited a maximal reflectance value of 8-11%, comparable to that of bird plumage (∼11%). This study provides a useful, simple, and low-cost approach to the fabrication of biomimetic thin-film reflectors using full dopamine-melanin materials.

  3. Genetic Diversity of Testa Pigments and RAPD Marker of Yellow-Seeded Rapeseed (Brassica napus L.)

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xue-kun; CHEN Li; YIN Jia-ming; TANG Zhang-lin; LI Jia-na

    2003-01-01

    14 yellow-seeded rapeseed lines (Brassia napus L. ) from different genetic sources were used toanalyze diversity of testa pigments content, oil and protein content, and RAPD markers. The results showedthat the anthocyanin and melanin were the most important pigments in testa and their content were responsiblefor the variation in seed color ranging from orange to black yellow, 14 yellow-seeded lines could be classifiedinto 3 groups., high anthocyanin content group with anthocyanin content over 2.54 mg g-1 DW, the seed colorwas light yellow or orange; low pigments content group with low content of anthocyanin and melanin, the testawas transparent and the seed color was light yellow, greenish yellow or twany; high melanin content groupwith melanin content over 178.4U(A290nm), the testa was black, the seed color was black yellow. Oil eantentchanged from 36.2% to 45.5%, protein content from 21.1% to 27.7%, and the correlation analysis revealedthat the oil content is highly significantly negatively correlated with the protein content. The cluster analysisshowed that the extensive genetic variation existed among 14 yellow-seeded lines by using unweighted pairedgroup method with arithmetic average (UPGMA) based on RAPD markers which were amplified with decamerprimers, the genetic similarity among them ranged from 0.25 to 0. 909, and 14 yellow-seeded lines could putinto 2 clusters corresponding to genome difference.

  4. Effect of UV irradiation on free radicals in synthetic melanin and melanin biopolymer from Sepia officinalis – EPR examination

    Directory of Open Access Journals (Sweden)

    Zdybel Magdalena

    2015-07-01

    Full Text Available Free radicals in synthetic melanin and melanin from Sepia officinalis were studied by electron paramagnetic resonance (EPR spectroscopy. The effect of time of ultraviolet (UV irradiation on free radicals in these melanins was tested. The samples were exposed to UV during 15, 30, and 60 minutes. EPR spectra were measured with microwaves from an X-band (9.3 GHz in the range of microwave power of 2.2–70 mW. The performed EPR examinations indicate that high concentrations (~1021–1022 spin/g of o-semiquinone free radicals with g factors of 2.0039–2.0045 exist in all the tested samples. For nonirradiated samples, free radical concentration was higher in natural melanin than in synthetic melanin. UV irradiation caused the increase of free radical concentrations in synthetic melanin samples and this effect depends on the time of irradiation. The largest free radical formation in the both melanins was obtained for 60 min of UV irradiation. Free radical concentrations after the UV irradiation of melanins during 30 min were lower than during irradiation by 15 min, and probably this effect was the result of recombination of the radiatively formed free radicals. EPR lines of the tested samples broadened with increasing microwave power, so these lines were homogeneously broadened. The two types of melanins differed in the time of spin-lattice relaxation processes. Slower spin-lattice relaxation processes exist in melanin from Sepia officinalis than in synthetic melanin. UV irradiation did not change the time of spin-lattice relaxation processes in the tested melanins. The performed studies confirmed the usefulness of EPR spectroscopy in cosmetology and medicine.

  5. Spectrophotometric intracutaneous analysis for differential diagnosis of pigmented skin lesions

    Directory of Open Access Journals (Sweden)

    Е. V. Filonenko

    2013-01-01

    Full Text Available The non-invasive diagnosis of pigmented skin lesions by spectrophotometric intracutaneous analysis (SIA-scopy using device for dermatoscopy (SIAscope V by Astron Clinica, Ltd was approved in P.A.Herzen Moscow Cancer Research Institute. The method is based on analysis of light interaction with wavelength of 440–960 nm anf human skin, which is recorded by change of image on scan. The comparative analysis of SIA-scopy and histological data in 327 pigmented skin lesions in 147 patients showed, that SIA had high diagnostic efficiency for cutaneous melanoma: the sensitivity was 96%, specifity – 94%, diagnostic accuracy – 94%. For study of malignant potential of pigmented lesions by SIA-scopy the most informative capacity was obtained for assessment of melanin in papillary dermis, status of blood vessels and collagen fibres (SIA-scans 3, 4, 5.

  6. Oral postinflammatory pigmentation: an analysis of 7 cases.

    Science.gov (United States)

    Mergoni, Giovanni; Ergun, Sertan; Vescovi, Paolo; Mete, Özgür; Tanyeri, Hakkı; Meleti, Marco

    2011-01-01

    Oral postinflammatory pigmentation (OPP) is a discoloration of the oral mucosa caused by an excess of melanin production and deposition within the basal layer of the epithelium and connective tissue of areas affected by chronic inflammation. Therefore, it is mandatory to demonstrate the association with a previous or concomitant inflammatory process in the same area of oral mucosa. Clinically OPP appears as a localized or diffuse, black to brown pigmentation. OPP may persist for many years even though the disappearing of the pigmentation after the resolution of the inflammatory state has been reported. We reviewed retrospectively the medical records and, when performed, biopsy examinations of 7 cases of OPP. Four cases were associated with oral lichen planus, two cases with lichenoid lesions and one case with proliferative verrucous leukoplakia. Despite a possible high prevalence of OPP, only a few reports concerning diagnosis, etiopathogenesis and clinical manifestation have been published so far.

  7. Identification of PaPKS1, a polyketide synthase involved in melanin formation and its use as a genetic tool in Podospora anserina.

    Science.gov (United States)

    Coppin, Evelyne; Silar, Philippe

    2007-08-01

    In the filamentous fungus Podospora anserina, many pigmentation mutations map to the median region of the complex locus '14', called segment '29'. The data presented in this paper show that segment 29 corresponds to a gene encoding a polyketide synthase, designated PaPKS1, and identifies two mutations that completely or partially abolish the activity of the PaPKS1 polypeptide. We present evidence that the P. anserina green pigment is a (DHN)-melanin. Using the powerful genetic system of PaPKS1 cloning, we demonstrate that in P. anserina trans-duplicated sequences are subject to the RIP process as previously demonstrated for the cis-duplicated regions.

  8. Dermoscopic Features of Facial Pigmented Skin Lesions

    Science.gov (United States)

    Goncharova, Yana; Attia, Enas A. S.; Souid, Khawla; Vasilenko, Inna V.

    2013-01-01

    Four types of facial pigmented skin lesions (FPSLs) constitute diagnostic challenge to dermatologists; early seborrheic keratosis (SK), pigmented actinic keratosis (AK), lentigo maligna (LM), and solar lentigo (SL). A retrospective analysis of dermoscopic images of histopathologically diagnosed clinically-challenging 64 flat FPSLs was conducted to establish the dermoscopic findings corresponding to each of SK, pigmented AK, LM, and SL. Four main dermoscopic features were evaluated: sharp demarcation, pigment pattern, follicular/epidermal pattern, and vascular pattern. In SK, the most specific dermoscopic features are follicular/epidermal pattern (cerebriform pattern; 100% of lesions, milia-like cysts; 50%, and comedo-like openings; 37.50%), and sharp demarcation (54.17%). AK and LM showed a composite characteristic pattern named “strawberry pattern” in 41.18% and 25% of lesions respectively, characterized by a background erythema and red pseudo-network, associated with prominent follicular openings surrounded by a white halo. However, in LM “strawberry pattern” is widely covered by psewdonetwork (87.5%), homogenous structureless pigmentation (75%) and other vascular patterns. In SL, structureless homogenous pigmentation was recognized in all lesions (100%). From the above mentioned data, we developed an algorithm to guide in dermoscopic features of FPSLs. PMID:23431466

  9. Natural melanin composites by layer-by-layer assembly

    Science.gov (United States)

    Eom, Taesik; Shim, Bong Sub

    2015-04-01

    Melanin is an electrically conductive and biocompatible material, because their conjugated backbone structures provide conducting pathways from human skin, eyes, brain, and beyond. So there is a potential of using as materials for the neural interfaces and the implantable devices. Extracted from Sepia officinalis ink, our natural melanin was uniformly dispersed in mostly polar solvents such as water and alcohols. Then, the dispersed melanin was further fabricated to nano-thin layered composites by the layer-by-layer (LBL) assembly technique. Combined with polyvinyl alcohol (PVA), the melanin nanoparticles behave as an LBL counterpart to from finely tuned nanostructured films. The LBL process can adjust the smart performances of the composites by varying the layering conditions and sandwich thickness. We further demonstrated the melanin loading degree of stacked layers, combination nanostructures, electrical properties, and biocompatibility of the resulting composites by UV-vis spectrophotometer, scanning electron microscope (SEM), multimeter, and in-vitro cell test of PC12, respectively.

  10. Characterization and Photoprotector Activity of Endophytic Fungal Pigments from Coatal Plant Sarang Semut (Hydnophytum formicarum

    Directory of Open Access Journals (Sweden)

    Mada Triandala Sabero

    2016-04-01

    Full Text Available Isolate endophytic fungal RS3 from smooth ant plants (Hydnophytum formicarum produced black pigment. The aims of this research were to obtain the pigment, to characterize and to determine the photoprotector activity. This research was consisted into several steps, there were determined the best precipitating agent, characterization using instrument and solubility analysis, and analysis of Sun Protection Factor (SPF. Results showed the pigment was precipitated using acid solvent with pH ≤ 2,5. Functional groups of pigment pellet were hydroxy, aromatic ring, phenol and amine. According to characteristic, black pigment produced by fungal RS3 proposed as melanin. The photoprotector analysis showed SPF the value was 11.33.

  11. Characterization and Photoprotector Activity of Endophytic Fungal Pigments from Coastal Plant Sarang Semut (Hydnophytum formicarum

    Directory of Open Access Journals (Sweden)

    Mada Triandala Sibero

    2016-04-01

    Full Text Available Endophytic fungus RS3 isolated from coastal plant sarang semut (Hydnophytum formicarum produced extracellular black pigment. The aims of this research were to obtain the pigment, to characterize and to determine the photoprotector activity. This research was conducted into several steps, that were determination of the best precipitating agent, characterization using instrument and solubility analysis, and analysis of Sun Protection Factor (SPF. Results showed the pigment was precipitated using acid solvent with pH ≤ 2.5. Functional groups of pigment were hydroxyl, aromatic ring, phenol and amine. According to its characteristics, black pigment produced by RS3 isolate was proposed as melanin. The photoprotector analysis showed the SPF value was 11.33.

  12. Mimicry's palette: widespread use of conserved pigments in the aposematic signals of snakes.

    Science.gov (United States)

    Kikuchi, David W; Seymoure, Brett M; Pfennig, David W

    2014-03-01

    Mimicry, where one species resembles another species because of the selective benefits of sharing a common signal, is especially common in snakes. Snakes might be particularly prone to evolving mimicry if all species share some of the same proximate mechanisms that can be used to produce aposematic/mimetic signals. We evaluated this possibility by examining color pigments in 11 species of snakes from four different families, three species of which participate in a coral snake mimicry complex involving convergence in coloration. We found that all 11 species used combinations of two pteridine pigments and melanin in their coloration, regardless of whether or not they were mimics. Furthermore, the presence or absence of red pteridines was strongly correlated with the relative excitation of medium- and long-wavelength photoreceptors in birds, thereby linking shared pigmentation to perception of those pigments by likely agents of selection. Thus, precise color mimicry might be relatively easy to evolve among snakes owing to symplesiomorphies in pigmentation.

  13. Laser therapy of pigmented lesions: pro and contra.

    Science.gov (United States)

    Bukvić Mokos, Zrinka; Lipozenčić, Jasna; Ceović, Romana; Stulhofer Buzina, Daška; Kostović, Krešimir

    2010-01-01

    Although frequently performed, laser removal of pigmented lesions still contains certain controversial issues. Epidermal pigmented lesions include solar lentigines, ephelides, café au lait macules and seborrheic keratoses. Dermal lesions include melanocytic nevi, blue nevi, drug induced hyperpigmentation and nevus of Ota and Ito. Some lesions exhibit both an epidermal and dermal component like Becker's nevus, postinflammatory hyperpigmentations, melasma and nevus spilus. Due to the wide absorption spectrum of melanin (500-1100 nm), several laser systems are effective in removal of pigmented lesions. These lasers include the pigmented lesion pulsed dye laser (510 nm), the Q-switched ruby laser (694 nm), the Q-switched alexandrite laser (755 nm) and the Q-switched Nd:YAG laser (1064 nm), which can be frequency-doubled to produce visible green light with a wavelength of 532 nm. The results of laser therapy are usually successful. However, there are still many controversies regarding the use of lasers in treating certain pigmented lesions. Actually, the essential question in removing pigmented lesions with lasers is whether the lesion has atypical features or has a malignant potential. Dermoscopy, used as a routine first-level diagnostic technique, is helpful in most cases. If there is any doubt whether the lesion is benign, then a biopsy for histologic evaluation is obligatory.

  14. Topical liposome targeting of dyes, melanins, genes, and proteins selectively to hair follicles.

    Science.gov (United States)

    Hoffman, R M

    1998-01-01

    For therapeutic and cosmetic modification of hair, we have developed a hair-follicle-selective macromolecule and small molecule targeting system with topical application of phosphatidylcholine-based liposomes. Liposome-entrapped melanins, proteins, genes, and small-molecules have been selectively targeted to the hair follicle and hair shafts of mice. Liposomal delivery of these molecules is time dependent. Negligible amounts of delivered molecules enter the dermis, epidermis, or bloodstream thereby demonstrating selective follicle delivery. Naked molecules are trapped in the stratum corneum and are unable to enter the follicle. The potential of the hair-follicle liposome delivery system for therapeutic use for hair disease as well as for cosmesis has been demonstrated in 3-dimensional histoculture of hair-growing skin and mouse in vivo models. Topical liposome selective delivery to hair follicles has demonstrated the ability to color hair with melanin, the delivery of the active lac-Z gene to hair matrix cells and delivery of proteins as well. Liposome-targeting of molecules to hair follicles has also been achieved in human scalp in histoculture. Liposomes thus have high potential in selective hair follicle targeting of large and small molecules, including genes, opening the field of gene therapy and other molecular therapy of the hair process to restore hair growth, physiologically restore or alter hair pigment, and to prevent or accelerate hair loss.

  15. Heavy Water as a Probe of the Free Radical Nature and Electrical Conductivity of Melanin.

    Science.gov (United States)

    Rienecker, Shermiyah B; Mostert, A Bernardus; Schenk, Gerhard; Hanson, Graeme R; Meredith, Paul

    2015-12-01

    Melanins are pigmentary macromolecules found in many locations throughout nature including plants and vertebrate animals. It was recently proposed that the predominant brown-black pigment eumelanin is a mixed ionic-electronic conductor which has led to renewed interest in its basic properties as a model bioelectronic material. This exotic hybrid electrical behavior is strongly dependent upon hydration and is closely related to the free radical content of melanin which is believed to be a mixed population of two species: the semiquinone (SQ) and a carbon-centered radical (CCR). The predominant charge carrier is the proton that is released during the formation of the SQ radical and controlled by a comproportionation equilibrium reaction. In this paper we present a combined solid-state electron paramagnetic resonance (EPR), adsorption, and hydrated conductivity study using D2O as a probe. We make specific predictions as to how the heavy isotope effect, in contrast to H2O, should perturb the comproportionation equilibrium and the related outcome as far as the electrical conductivity is concerned. Our EPR results confirm the proposed two-spin mechanism and clearly demonstrate the power of combining macroscopic measurements with observations from mesoscopic probes for the study of bioelectronic materials.

  16. 4-(Phenylsulfanylbutan-2-One Suppresses Melanin Synthesis and Melanosome Maturation In Vitro and In Vivo

    Directory of Open Access Journals (Sweden)

    Shing-Yi Sean Wu

    2015-08-01

    Full Text Available In this study, we screened compounds with skin whitening properties and favorable safety profiles from a series of marine related natural products, which were isolated from Formosan soft coral Cladiella australis. Our results indicated that 4-(phenylsulfanylbutan-2-one could successfully inhibit pigment generation processes in mushroom tyrosinase platform assay, probably through the suppression of tyrosinase activity to be a non-competitive inhibitor of tyrosinase. In cell-based viability examinations, it demonstrated low cytotoxicity on melanoma cells and other normal human cells. It exhibited stronger inhibitions of melanin production and tyrosinase activity than arbutin or 1-phenyl-2-thiourea (PTU. Also, we discovered that 4-(phenylsulfanylbutan-2-one reduces the protein expressions of melanin synthesis-related proteins, including the microphthalmia-associated transcription factor (MITF, tyrosinase-related protein-1 (Trp-1, dopachrome tautomerase (DCT, Trp-2, and glycoprotein 100 (GP100. In an in vivo zebrafish model, it presented a remarkable suppression in melanogenesis after 48 h. In summary, our in vitro and in vivo biological assays showed that 4-(phenylsulfanylbutan-2-one possesses anti-melanogenic properties that are significant in medical cosmetology.

  17. Melanin Transfer in Human 3D Skin Equivalents Generated Exclusively from Induced Pluripotent Stem Cells.

    Directory of Open Access Journals (Sweden)

    Karl Gledhill

    Full Text Available The current utility of 3D skin equivalents is limited by the fact that existing models fail to recapitulate the cellular complexity of human skin. They often contain few cell types and no appendages, in part because many cells found in the skin are difficult to isolate from intact tissue and cannot be expanded in culture. Induced pluripotent stem cells (iPSCs present an avenue by which we can overcome this issue due to their ability to be differentiated into multiple cell types in the body and their unlimited growth potential. We previously reported generation of the first human 3D skin equivalents from iPSC-derived fibroblasts and iPSC-derived keratinocytes, demonstrating that iPSCs can provide a foundation for modeling a complex human organ such as skin. Here, we have increased the complexity of this model by including additional iPSC-derived melanocytes. Epidermal melanocytes, which are largely responsible for skin pigmentation, represent the second most numerous cell type found in normal human epidermis and as such represent a logical next addition. We report efficient melanin production from iPSC-derived melanocytes and transfer within an entirely iPSC-derived epidermal-melanin unit and generation of the first functional human 3D skin equivalents made from iPSC-derived fibroblasts, keratinocytes and melanocytes.

  18. Effect of norfloxacin and moxifloxacin on melanin synthesis and antioxidant enzymes activity in normal human melanocytes.

    Science.gov (United States)

    Beberok, Artur; Wrześniok, Dorota; Otręba, Michał; Miliński, Maciej; Rok, Jakub; Buszman, Ewa

    2015-03-01

    Fluoroquinolone antibiotics provide broad-spectrum coverage for a number of infectious diseases, including respiratory as well as urinary tract infections. One of the important adverse effects of these drugs is phototoxicity which introduces a serious limitation to their use. To gain insight the molecular mechanisms underlying the fluoroquinolones-induced phototoxic side effects, the impact of two fluoroquinolone derivatives with different phototoxic potential, norfloxacin and moxifloxacin, on melanogenesis and antioxidant enzymes activity in normal human melanocytes HEMa-LP was determined. Both drugs induced concentration-dependent loss in melanocytes viability. The value of EC50 for these drugs was found to be 0.5 mM. Norfloxacin and moxifloxacin suppressed melanin biosynthesis; antibiotics were shown to inhibit cellular tyrosinase activity and to reduce melanin content in melanocytes. When comparing the both analyzed fluoroquinolones, it was observed that norfloxacin possesses greater inhibitory effect on tyrosinase activity in melanocytes than moxifloxacin. The extent of oxidative stress in cells was assessed by measuring the activity of antioxidant enzymes: SOD, CAT, and GPx. It was observed that norfloxacin caused higher depletion of antioxidant status in melanocytes when compared with moxifloxacin. The obtained results give a new insight into the mechanisms of fluoroquinolones toxicity directed to pigmented tissues. Moreover, the presented differences in modulation of biochemical processes in melanocytes may be an explanation for various phototoxic activities of the analyzed fluoroquinolone derivatives in vivo.

  19. Skin pigmentation and texture changes after hair removal with the normal-mode ruby laser.

    Science.gov (United States)

    Haedersdal, M; Egekvist, H; Efsen, J; Bjerring, P

    1999-11-01

    Promising clinical results have been obtained with the normal mode ruby laser for removal of unwanted hair. Melanin within the hair follicles is thought to act as target for the ruby laser pulses, whereas epidermal melanin is thought to be a competitive chromophore, responsible for potential side effects. This study aimed (i) to objectify postoperative changes in skin pigmentation and texture and (ii) to evaluate the importance of variations in preoperative skin pigmentation for the development of side effects 12 weeks after 1 treatment with the normal-mode ruby laser. A total of 17 volunteers (skin types I-IV) were laser-treated in the hairy pubic region (n = 51 test areas). A shaved test area served as control. Skin reflectance spectroscopical measurements, 3-dimensional surface contour analysis and ultrasonography objectified postoperative changes in skin pigmentation and texture. Blinded clinical assessments revealed postoperative hyperpigmentation (2% of test areas) and hypopigmentation (10%), whereas no textural changes were seen. Reflectance spectroscopically-determined pigmentary changes depended on the degree of preoperative skin pigmentation, fairly pigmented skin types experiencing subclinical hyperpigmentation and darkly pigmented skin types experiencing subclinical hypopigmentation. Three-dimensional surface profilometry documented similar pre- and postoperative surface contour parameters, indicating that the skin surface texture is preserved after laser exposure. Ultrasonography revealed similar skin thicknesses in laser-exposed and untreated control areas. It is concluded that normal-mode ruby laser treatment is safe for hair removal in skin types I-IV.

  20. Melanin Biosynthesis Inhibition Effects of Ginsenoside Rb2 Isolated from Panax ginseng Berry.

    Science.gov (United States)

    Lee, Dae Young; Jeong, Yong Tae; Jeong, Sang Chul; Lee, Mi Kyoung; Min, Jin Woo; Lee, Jae Won; Kim, Geum Soog; Lee, Seung Eun; Ahn, Young Sup; Kang, Hee Cheol; Kim, Jin Hee

    2015-12-28

    Ginsenoside Rb2 (Gin-Rb2) was purified from the fruit extract of Panax ginseng. Its chemical structure was measured by spectroscopic analysis, including HR-FAB-MS, (1)H-NMR, and IR spectroscopy. Gin-Rb2 decreased potent melanogenesis in melan-a cells, with 23.4% at 80 μM without cytotoxicity. Gin-Rb2 also decreased tyrosinase and MITF protein expression in melan-a cells. Furthermore, Gin-Rb2 presented inhibition of the body pigmentation in the zebrafish in vivo system and reduced melanin contents and tyrosinase activity. These results show that Gin-Rb2 isolated from P. ginseng may be an effective skin-whitening agent via the in vitro and in vivo systems.

  1. Novel Inhibitory Effect of N-(2-Hydroxycyclohexylvaliolamine on Melanin Production in a Human Skin Model

    Directory of Open Access Journals (Sweden)

    Bum-Ho Bin

    2014-07-01

    Full Text Available Hyper-pigmentation causes skin darkness and medical disorders, such as post-inflammatory melanoderma and melasma. Therefore, the development of anti-melanogenic agents is important for treating these conditions and for cosmetic production. In our previous paper, we demonstrated that the anti-diabetic drug voglibose, a valiolamine derivative, is a potent anti-melanogenic agent. In addition, we proposed an alternative screening strategy to identify valiolamine derivatives with high skin permeability that act as anti-melanogenic agents when applied topically. In this study, we synthesized several valiolamine derivatives with enhanced lipophilicity and examined their inhibitory effects in a human skin model. N-(2-hydroxycyclohexylvaliolamine (HV possesses a stronger inhibitory effect on melanin production than voglibose in a human skin model, suggesting that HV is a more potent anti-melanogenic agent for the skin.

  2. Pigmented Villonodular Synovitis (PVNS)

    Science.gov (United States)

    ... OverviewWhat is pigmented villonodular synovitis?Pigmented villonodular synovitis (PVNS) is a joint problem that usually affects the ... ankle, elbow, hand or foot.When you have PVNS, the lining of a joint becomes swollen and ...

  3. Bleaching of melanin in the epidermis of South American fur seal and its application on enzyme immunohistochemistry

    Directory of Open Access Journals (Sweden)

    A.P. Silva

    2011-03-01

    Full Text Available The South American fur seal (Arctocephalus australis is an amphibious marine mammal distributed along the Atlantic and Pacific coasts of South America. The species is well adjusted to different habitats due to the morphology of its fin-like members and due to some adaptations in their integumentary system. Immunohistochemical studies are very important to evaluate the mechanisms of skin adaptation due the differential expression of the antigens present in the tissue depending of the region of the body surface. However, its strongly pigmented (melanin epidermis prevents the visualization of the immuno-histochemical chromogens markers. In this study a melanin bleaching method was developed aimed to allow the visualization of the chromogens without interfering in the antigen-antibody affinity for immunohistochemistry. The analysis of PCNA (proliferating cell nuclear antigen index in the epidermis of A. australis by immunohistochemistry with diaminobenzidine (DAB as chromogen was used to test the method. The bleaching of the melanin allowed to obtain the cell proliferation index in epidermis and to avoid false positive results without affecting the immunohistochemical results.

  4. A potential benefit of albinism in Astyanax cavefish: downregulation of the oca2 gene increases tyrosine and catecholamine levels as an alternative to melanin synthesis.

    Science.gov (United States)

    Bilandžija, Helena; Ma, Li; Parkhurst, Amy; Jeffery, William R

    2013-01-01

    Albinism, the loss of melanin pigmentation, has evolved in a diverse variety of cave animals but the responsible evolutionary mechanisms are unknown. In Astyanax mexicanus, which has a pigmented surface dwelling form (surface fish) and several albino cave-dwelling forms (cavefish), albinism is caused by loss of function mutations in the oca2 gene, which operates during the first step of the melanin synthesis pathway. In addition to albinism, cavefish have evolved differences in behavior, including feeding and sleep, which are under the control of the catecholamine system. The catecholamine and melanin synthesis pathways diverge after beginning with the same substrate, L-tyrosine. Here we describe a novel relationship between the catecholamine and melanin synthesis pathways in Astyanax. Our results show significant increases in L-tyrosine, dopamine, and norepinephrine in pre-feeding larvae and adult brains of Pachón cavefish relative to surface fish. In addition, norepinephrine is elevated in cavefish adult kidneys, which contain the teleost homologs of catecholamine synthesizing adrenal cells. We further show that the oca2 gene is expressed during surface fish development but is downregulated in cavefish embryos. A key finding is that knockdown of oca2 expression in surface fish embryos delays the development of pigmented melanophores and simultaneously increases L-tyrosine and dopamine. We conclude that a potential evolutionary benefit of albinism in Astyanax cavefish may be to provide surplus L-tyrosine as a precursor for the elevated catecholamine synthesis pathway, which could be important for adaptation to the challenging cave environment.

  5. A potential benefit of albinism in Astyanax cavefish: downregulation of the oca2 gene increases tyrosine and catecholamine levels as an alternative to melanin synthesis.

    Directory of Open Access Journals (Sweden)

    Helena Bilandžija

    Full Text Available Albinism, the loss of melanin pigmentation, has evolved in a diverse variety of cave animals but the responsible evolutionary mechanisms are unknown. In Astyanax mexicanus, which has a pigmented surface dwelling form (surface fish and several albino cave-dwelling forms (cavefish, albinism is caused by loss of function mutations in the oca2 gene, which operates during the first step of the melanin synthesis pathway. In addition to albinism, cavefish have evolved differences in behavior, including feeding and sleep, which are under the control of the catecholamine system. The catecholamine and melanin synthesis pathways diverge after beginning with the same substrate, L-tyrosine. Here we describe a novel relationship between the catecholamine and melanin synthesis pathways in Astyanax. Our results show significant increases in L-tyrosine, dopamine, and norepinephrine in pre-feeding larvae and adult brains of Pachón cavefish relative to surface fish. In addition, norepinephrine is elevated in cavefish adult kidneys, which contain the teleost homologs of catecholamine synthesizing adrenal cells. We further show that the oca2 gene is expressed during surface fish development but is downregulated in cavefish embryos. A key finding is that knockdown of oca2 expression in surface fish embryos delays the development of pigmented melanophores and simultaneously increases L-tyrosine and dopamine. We conclude that a potential evolutionary benefit of albinism in Astyanax cavefish may be to provide surplus L-tyrosine as a precursor for the elevated catecholamine synthesis pathway, which could be important for adaptation to the challenging cave environment.

  6. 玉米大斑病菌黑色素合成酶基因的全基因组定位及表达模式分析%Localization of Melanin Biosynthesis Enzyme Genes in the Genome and Expression Pattern Analysis of Setosphaeria turcica

    Institute of Scientific and Technical Information of China (English)

    贾慧; 孟庆江; 李志勇; 巩校东; 藏金萍; 郝志敏; 曹志艳; 董金皋

    2015-01-01

    的作用更明显,分生孢子时期StLAC2更活跃。%Objective]The objectives of this study are to determine the location in the genome, and to investigate the structure ofmelanin biosynthesis genes StPKS, StSCD, St3HNR, St4HNR, StLAC1 and StLAC2 ofSetosphaeria turcica. Furthermore, to elucidate the relationship between melanin biosynthesis enzyme genes and morphogenesis and pathogenicity ofS. turcicavia analyzing the expression pattern of six genes during infection progress from conidial germination to penetration and the mycelia growth period.[Method] Based on theS.turcicagenome database and genome searching with Blastp, the locations of six genes were identified and genes linkage were analyzed. Primers were designed according to the six melanin synthesis enzyme gene sequences. qRT-PCR system was used to detect the six genes expressions ofS. turcica, in which total RNAs from different infectious morphogenesis stages including conidial germination to penetration were extracted and used as templates andβ-tubulinas the reference gene, and the expression patterns between vegetative and reproductive growth stages were compared.[Result]In genome database, theStPKS andSt3HNR were located on the positive and negative strand of scaffold_12, respectively.St4HNR andStLAC2 were on the negative strand scaffold_11.StSCD andStLAC1 located on the positive of strand scaffold_1 and scaffold_7, respectively. Furthermore,StPKSandSt3HNR were clustered within the 26.9 kb chromosomal region. Relative expression of six genes had two expression profiles, which was up-down- up regulation or up- down- up- down regulation at five stages from conidial germination to penetration. TheStLAC2 had the highest expression in conidia, and there was a significant difference in expression. However, St3HNRand StSCD had a higher expression level than other genes in mycelia.[Conclusion]StPKSandSt3HNR in melanin biosynthesis were clustered within a 26.9 kb chromosomal region. Six genes were whole

  7. Binding characteristics of fluoroquinolones to synthetic levodopa melanin.

    Science.gov (United States)

    Ono, Chiho; Tanaka, Makoto

    2003-08-01

    To define the binding characteristics of fluoroquinolones to synthetic levodopa melanin, the binding of various drugs, including levofloxacin and ofloxacin, and positive controls (timolol and chloroquine), was investigated in-vitro. The affinity and capacity of the drug binding were calculated by Langmuir's adsorption isotherm. The affinity constant (K) and the binding capacity (r(max)) of levofloxacin were similar to those of timolol and much lower than those of chloroquine. Racemic ofloxacin and its enantiomers showed similar K and r(max), suggesting that the binding lacked stereoselectivity. The binding experiment with levofloxacin derivatives indicated that the basic nitrogen atom at position 7 of the quinolone ring, but not carboxyl group at position 3, would play a critical role in the interaction of fluoroquinolones with melanin. The melanin-drug complexes of levofloxacin and chloroquine were washed with neutral phosphate buffer, ethanol and 1 M HCl solution to explain the nature of the interaction of melanin with the drugs. Electrostatic forces mainly participate in the formation of the chloroquine-melanin complex, whereas van der Waals' and hydrophobic interactions are involved in the levofloxacin-melanin complex in addition to electrostatic forces. The interactions of various fluoroquinolones such as norfloxacin, enoxacin, sparfloxacin, ciprofloxacin and lomefloxacin with melanin were also studied. The results showed that the relative K value was: chloroquine approximately ciprofloxacin, sparfloxacin >/= lomefloxacin > timolol, levofloxacin approximately enoxacin, norfloxacin, and that the relative r(max) value was: norfloxacin, enoxacin >/= chloroquine, sparfloxacin > levofloxacin, ciprofloxacin, timolol, lomefloxacin. The fluoroquinolones vary in their affinity and capacity to bind with melanin, and ciprofloxacin and sparfloxacin showed a stronger interaction with melanin than the other fluoroquinolones studied.

  8. Neovascularisation by tattoo pigment

    Directory of Open Access Journals (Sweden)

    Abdul Razack E

    1991-01-01

    Full Text Available Split skin grafting for the removal of a tattoo resulted in the appearance of pigmented papules in the periphery of the grafted skin as well as distal to it on the normal skin. Histologically they showed large vascular laminae containing red blood corpuscles and pigment deposits, a hitherto not documented complication of tattoo pigment.

  9. Overview of plant pigments

    Science.gov (United States)

    Chlorophylls, carotenoids, flavonoids and betalains are four major classes of biological pigments produced in plants. Chlorophylls are the primary pigments responsible for plant green and photosynthesis. The other three are accessary pigments and secondary metabolites that yield non-green colors and...

  10. Subcellular Compartmentalization and Trafficking of the Biosynthetic Machinery for Fungal Melanin.

    Science.gov (United States)

    Upadhyay, Srijana; Xu, Xinping; Lowry, David; Jackson, Jennifer C; Roberson, Robert W; Lin, Xiaorong

    2016-03-22

    Protection by melanin depends on its subcellular location. Although most filamentous fungi synthesize melanin via a polyketide synthase pathway, where and how melanin biosynthesis occurs and how it is deposited as extracellular granules remain elusive. Using a forward genetic screen in the pathogen Aspergillus fumigatus, we find that mutations in an endosomal sorting nexin abolish melanin cell-wall deposition. We find that all enzymes involved in the early steps of melanin biosynthesis are recruited to endosomes through a non-conventional secretory pathway. In contrast, late melanin enzymes accumulate in the cell wall. Such subcellular compartmentalization of the melanin biosynthetic machinery occurs in both A. fumigatus and A. nidulans. Thus, fungal melanin biosynthesis appears to be initiated in endosomes with exocytosis leading to melanin extracellular deposition, much like the synthesis and trafficking of mammalian melanin in endosomally derived melanosomes.

  11. Subcellular Compartmentalization and Trafficking of the Biosynthetic Machinery for Fungal Melanin

    OpenAIRE

    Srijana Upadhyay; Xinping Xu; David Lowry; Jennifer C. Jackson; Robert W. Roberson; Xiaorong Lin

    2016-01-01

    Protection by melanin depends on its subcellular location. Although most filamentous fungi synthesize melanin via a polyketide synthase pathway, where and how melanin biosynthesis occurs, and how it is deposited as extracellular granules, remain elusive. Using a forward genetic screen in the pathogen Aspergillus fumigatus, we find that mutations in an endosomal sorting nexin abolish melanin cell wall deposition. We find that all enzymes involved in the early steps of melanin biosynthesis are ...

  12. Auto white balance method using a pigmentation separation technique for human skin color

    Science.gov (United States)

    Tanaka, Satomi; Kakinuma, Akihiro; Kamijo, Naohiro; Takahashi, Hiroshi; Tsumura, Norimichi

    2017-02-01

    The human visual system maintains the perception of colors of an object across various light sources. Similarly, current digital cameras feature an auto white balance function, which estimates the illuminant color and corrects the color of a photograph as if the photograph was taken under a certain light source. The main subject in a photograph is often a person's face, which could be used to estimate the illuminant color. However, such estimation is adversely affected by differences in facial colors among individuals. The present paper proposes an auto white balance algorithm based on a pigmentation separation method that separates the human skin color image into the components of melanin, hemoglobin and shading. Pigment densities have a uniform property within the same race that can be calculated from the components of melanin and hemoglobin in the face. We, thus, propose a method that uses the subject's facial color in an image and is unaffected by individual differences in facial color among Japanese people.

  13. Auto white balance method using a pigmentation separation technique for human skin color

    Science.gov (United States)

    Tanaka, Satomi; Kakinuma, Akihiro; Kamijo, Naohiro; Takahashi, Hiroshi; Tsumura, Norimichi

    2016-11-01

    The human visual system maintains the perception of colors of an object across various light sources. Similarly, current digital cameras feature an auto white balance function, which estimates the illuminant color and corrects the color of a photograph as if the photograph was taken under a certain light source. The main subject in a photograph is often a person's face, which could be used to estimate the illuminant color. However, such estimation is adversely affected by differences in facial colors among individuals. The present paper proposes an auto white balance algorithm based on a pigmentation separation method that separates the human skin color image into the components of melanin, hemoglobin and shading. Pigment densities have a uniform property within the same race that can be calculated from the components of melanin and hemoglobin in the face. We, thus, propose a method that uses the subject's facial color in an image and is unaffected by individual differences in facial color among Japanese people.

  14. Pigments of fly agaric (Amanita muscaria).

    Science.gov (United States)

    Stintzing, Florian; Schliemann, Willibald

    2007-01-01

    The complex pigment pattern of fly agaric (Amanita muscaria) cap skins has been studied by LC-DAD and mass spectrometry. Among the betaxanthins the corresponding derivatives of serine, threonine, ethanolamine, alanine, Dopa, phenylalanine and tryptophan are reported for the first time to contribute to the pigment pattern of fly agarics. Betalamic acid, the chromophoric precursor of betaxanthins and betacyanins, muscaflavin and seco-dopas were also detected. Furthermore, the red-purple muscapurpurin and the red muscarubrin were tentatively assigned while further six betacyanin-like components could not be structurally allocated. Stability studies indicated a high susceptibility of pigment extracts to degradation which led to rapid colour loss thus rendering a complete characterization of betacyanin-like compounds impossible at present. Taking into account these difficulties the presented results may be a starting point for a comprehensive characterization of the pigment composition of fly agarics.

  15. Pseudoephedrine may cause "pigmenting" fixed drug eruption.

    Science.gov (United States)

    Ozkaya, Esen; Elinç-Aslan, Meryem Sevinç

    2011-05-01

    Fixed drug eruption (FDE) is a distinctive drug eruption characterized by recurrent well-defined lesions in the same location each time the responsible drug is taken. Two different clinical forms have been described: the common classic pigmenting form and the rare nonpigmenting form. Nonpigmenting FDE is mainly characterized by symmetrical large erythematous plaques and the dermal histopathologic reaction pattern. Pseudoephedrine is known as the major inducer of nonpigmenting FDE. Pigmenting FDE from pseudoephedrine has not been reported previously. Here, the first case of pseudoephedrine-induced pigmenting FDE is reported, showing the characteristic features of classic pigmenting FDE such as asymmetry, normal-sized lesions, and the epidermodermal histopathologic reaction pattern. Moreover, a positive occlusive patch-test reaction to pseudoephedrine could be demonstrated on postlesional FDE skin for the first time.

  16. Expression of melanin and insecticidal protein from Rhodotorula ...

    African Journals Online (AJOL)

    SERVER

    2006-02-16

    Feb 16, 2006 ... Key words: Rhodotorula glutinis, Escherichia coli, Melanin, Insecticidal Protein. INTRODUCTION ... proteinaceous crystals toxic to different insect larvae (Bulla ..... Gulex univitattus, Aedes aegypti and Culex pipens. Mosq.

  17. Morphological and chemical composition characterization of commercial sepia melanin

    CSIR Research Space (South Africa)

    Mbonyiryivuze, A

    2015-06-01

    Full Text Available of functions in the biosystem, including photosensitization, metal ion chelation, photoprotection to absorb a broad range of electromagnetic radiation, antibiotic, thermoregulation [6]. Melanins are found all over the body from the skin and blood...

  18. Evolution of pigment cell regression in the cavefish Astyanax: a late step in melanogenesis.

    Science.gov (United States)

    McCauley, David W; Hixon, Ernest; Jeffery, William R

    2004-01-01

    Pigmentation and eyes are often lost in cave-adapted animals. Although the mechanisms of eye degeneration are beginning to be understood, little is known about the evolutionary and developmental processes involved in pigment cell regression. In teleost embryos, a population of neural crest cells migrates into the body wall and differentiates into melanophores, xanthophores, and iridophores. All three pigment cell types are present in the eyed surface-dwelling form (surface fish) of the teleost Astyanax mexicanus. However, melanophores are absent or substantially reduced in number in various derived populations of the conspecific blind cave-dwelling form (cavefish). We show here that tyrosinase-positive melanoblasts are present in cavefish. DiI labeling revealed a population of trunk neural crest cells in cavefish embryos that migrate to locations normally occupied by differentiated melanophores. We also discovered a cell population in cavefish embryos and adults resembling melanoblasts in several features, including the ability to synthesize melanin when supplied with the tyrosinase substrate l-dopa. DiI-tyrosinase double-labeling and neural keel explant experiments showed that the tyrosinase-positive cells are derived from the neural crest. The number of melanoblasts varies in different adult cavefish populations relative to the extent of melanophore reduction. Although cavefish melanoblasts can synthesize melanin from exogenous l-dopa, they are unable to convert exogenous l-tyrosine to l-dopa and melanin. We conclude that pigment cell regression in cavefish is mediated by an evolutionary change late in melanogenesis that may involve an impediment in the ability to convert l-tyrosine to l-dopa and melanin.

  19. Comparative Methods to Improve the Detection of BRAF V600 Mutations in Highly Pigmented Melanoma Specimens

    OpenAIRE

    Frouin, Eric; Maudelonde, Thierry; Senal, Romain; Larrieux, Marion; Costes, Valérie; Godreuil, Sylvain; Vendrell, Julie A.; Solassol, Jérôme

    2016-01-01

    Genotyping BRAF in melanoma samples is often challenging. The presence of melanin greatly interferes with thermostable DNA polymerases and/or nucleic acids in traditional polymerase chain reaction (PCR)-based methods. In the present work, we evaluated three easy-to-use strategies to improve the detection of pigmented DNA refractory to PCR amplification. These pre-PCR processing methods include the addition of bovine serum albumin (BSA), the dilution of DNA, and the purification of DNA using t...

  20. [Intervention of nicotinamide on skin melanin genesis after UVA exposed].

    Science.gov (United States)

    Patam, Muhammad; Jin, Xi-peng; Zhang, Yu-bin; Pan, Jian-ying; Shen, Guang-zu

    2007-08-01

    To investigate the interference effect of nicotinamide on UVA-induced melanin genesis and melanin transport in human skin melanocyte. The optimum UVA dose expected to cause cell proliferation: 0.2 J/cm(2), nicotinamide was added immediately after the 0.2 J/cm(2) UVA exposure and the melanin content, cell cycles, cell apoptosis and mRNA express level were measured respectively. Melanin content in melanocytes was increased significantly after exposed to 0.2 J/cm(2) UVA. Melanin content in melanocytes was decreased after treatment with 10.0 mmol/ml nicotinamide following UVA exposure, but the cell cycles and the cell apoptosis rate were not significantly altered. mRNA express levels of TYR, TRP-1 were modulated by nicotinamide. Nicotinamide has more effect on decreasing melanin genesis after UVA exposure, nicotinamide also plays a role in modulating the mRNA express of TYR, TRP-1 gene. It is possible to consider nicotinamide as an efficient and safe sun screen to provide a certain level of protection for UVA exposed skin.

  1. 黑木耳天然黑色素理化性质及其抗氧化活性的研究%Physicochemical properties and antioxidant activities of Auricularia auricula melanin

    Institute of Scientific and Technical Information of China (English)

    邹宇; 尹冬梅; 胡文忠; 姜爱丽; 陈晨; 顾振新

    2013-01-01

    The physicochemical properties and antioxidant activities of Auricularia auricula(A.auricula)melanin were studied.The result showed that Aauricula melanin powder was dark with a little red and yellow colored( L* =41.03, a* =2.26, b* =3.78).The solubility properties of A.auricula melanin were very similar to those of the typical melanin.A auricula melanin possessed a stronger thermal stability and pigment retention rate was 88.0% after heating at 100℃ for 4h.Whereas, A auricula melanin was sensitive to light and pigment retention rate was only 25.3% when irradiation for 5d by natural light.A auricula melanin exhibited a strong antioxidant activity.At concentration of l.Omg/mL, hydroxyl radical scavenging activity and lipid peroxidation inhibiting activity of Aauricula melanin were greater than 40%.Thus, Aauricula melanin could be further used as a natural healthful food colorant.%对黑木耳天然黑色素的理化性质与抗氧化活性进行了研究,结果表明:黑木耳天然黑色素粉末呈黑色(L*=41.03),略带红色和黄色(a*=2.26,b*=3.78),具有与其他黑色素相似的溶解性;黑木耳黑色素热稳定性较强,100℃加热4h后,色素保存率仍达到88.0%,但对光照敏感,自然光照射5d时残存的黑色素仅为25.3%;黑木耳黑色素具有较强的抗氧化能力,1.0mg/mL浓度的黑色素溶液羟自由基清除率和脂质过氧化抑制率均在40%以上.黑木耳黑色素可进一步开发为具有保健功能的天然食用色素.

  2. Cd 2+ effect on free radicals in Cladosporium cladosporioides-melanin tested by EPR spectroscopy

    Science.gov (United States)

    Matuszczyk, Magdalena; Buszman, Ewa; Pilawa, Barbara; Witoszyńska, Teresa; Wilczok, Tadeusz

    2004-08-01

    Changes in free radicals system of Cladosporium cladosporioides-melanin and model DOPA-melanin caused by diamagnetic Cd 2+ ions were studied by electron paramagnetic resonance (EPR) spectroscopy. EPR line of eumelanin was mainly found in the spectrum of Cl.cl.-melanin. Cd 2+ ions increased o-semiquinone free radicals concentration in both natural and synthetic melanins. Cd 2+ broadened EPR lines of Cl.cl.-melanin in mycelium and the ions fastened spin-lattice relaxation processes. The narrower EPR lines and slower spin-lattice relaxation were obtained for DOPA-melanin-Cd 2+ complexes than for DOPA-melanin. Pheomelanin additionally existing in Cl.cl. samples was responsible for differences between the EPR data for Cl.cl. melanin and DOPA-melanin.

  3. Nevus of ota with buccal mucosal pigmentation: a rare case.

    Science.gov (United States)

    Shetty, Shishir Ram; Subhas, Babu G; Rao, Kumuda Arvind; Castellino, Renita

    2011-01-01

    Nevus of Ota is a condition wherein the typical pattern of the bluish black pigmentation is noticed along with the cutaneous distribution of the trigeminal nerve. This condition is most prevalent in Japanese population but comparatively rare among Indians. We report a case of 23-year-old female presented with unilateral pigmented areas over the skin of forehead, malar area, ear and periorbital area. Blackish-blue pigmented areas were also noticed on the sclera. Brownish-black diffuse pigmented areas were also noticed on the buccal mucosa of the same side. The presence of pigmentation on the skin over pinna and oral pigmentation made our case a rare incidence. Oral pigmentations associated with nevus of Ota especially on the buccal mucosa have rarely been reported in the past.

  4. Nevus of Ota with buccal mucosal pigmentation: A rare case

    Directory of Open Access Journals (Sweden)

    Shishir Ram Shetty

    2011-01-01

    Full Text Available Nevus of Ota is a condition wherein the typical pattern of the bluish black pigmentation is noticed along with the cutaneous distribution of the trigeminal nerve. This condition is most prevalent in Japanese population but comparatively rare among Indians. We report a case of 23-year-old female presented with unilateral pigmented areas over the skin of forehead, malar area, ear and periorbital area. Blackish-blue pigmented areas were also noticed on the sclera. Brownish-black diffuse pigmented areas were also noticed on the buccal mucosa of the same side. The presence of pigmentation on the skin over pinna and oral pigmentation made our case a rare incidence. Oral pigmentations associated with nevus of Ota especially on the buccal mucosa have rarely been reported in the past.

  5. Effect of an indigenous herbal combination on the melanin pigmentation activity in vitiligo patients.

    OpenAIRE

    Yadav NR; SC Gupta; Singh KG; Tripathi UC

    1994-01-01

    ABSTRACT: Ninteen of the twenty three vitiligo patients showed 30 to 95 percent skin repigmentation during forty eight weeks herbal therapy period when examined irrespective of different hypotheses concerning the pathogenesis of the skin depigmentation including vitiligo. More than 50 percent of the vitiligo patients under the trial depicted a speedy and well marked skin repigmentation ranging from 45 to 95 percent by the herbal drugs under examination. Whereas one patient showed a hundred pe...

  6. Towards the development of a novel bioinspired functional material: synthesis and characterization of hybrid TiO2/DHICA-melanin nanoparticles.

    Science.gov (United States)

    Pezzella, Alessandro; Capelli, Luigia; Costantini, Aniello; Luciani, Giuseppina; Tescione, Fabiana; Silvestri, Brigida; Vitiello, Giuseppe; Branda, Francesco

    2013-01-01

    A large number of recent literature data focus on modification/modulation of surface chemistry of inorganic materials in order to improve their functional properties. Melanins, a wide class of natural pigments, are recently emerging as a powerful organic component for developing bioinspired active material for a large number of applications from organoelectronics to bioactive compounds. Here we report the use of the approach referred as "chimie douce", involving in situ formation of the hybrids through reactions of precursors under mild conditions, to prepare novel hybrid functional architectures based on eumelanin like 5,6 dihydroxyindole-2-carboxylic acid (DHICA) polymer and TiO2. Two synthesis procedures were carried out to get DHICA-melanin coated TiO2 nanoparticles as well as mixed DHICA/TiO2 hybrid nanostructures. Such systems were characterized through EPR, FT-IR and fluorescence spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD), and TEM microscopy in order to assess the effect of synthesis path as well as of DHICA content on structural, morphological and optical properties of TiO2 nanostructures. In particular, EPR, FT-IR spectra and TGA analysis confirmed the presence of DHICA-melanin in these samples. TEM measurements indicated the formation of the nanoparticles having relatively narrow size distribution with average particle size of about 10nm. DHICA-melanin does act as a morphological agent affecting morphology of hybrid nanostructures. XRD analysis proved that TiO2 hybrid nanoparticles kept anatase structures for DHICA-melanin contents within the range of investigated compositions, i.e. up to 50% wt/wt.

  7. Key regulatory role of dermal fibroblasts in pigmentation as demonstrated using a reconstructed skin model: impact of photo-aging.

    Directory of Open Access Journals (Sweden)

    Christine Duval

    Full Text Available To study cutaneous pigmentation in a physiological context, we have previously developed a functional pigmented reconstructed skin model composed of a melanocyte-containing epidermis grown on a dermal equivalent comprising living fibroblasts. The present studies, using the same model, aimed to demonstrate that dermal fibroblasts influence skin pigmentation up to the macroscopic level. The proof of principle was performed with pigmented skins differing only in the fibroblast component. First, the in vitro system was reconstructed with or without fibroblasts in order to test the global influence of the presence of this cell type. We then assessed the impact of the origin of the fibroblast strain on the degree of pigmentation using fetal versus adult fibroblasts. In both experiments, impressive variation in skin pigmentation at the macroscopic level was observed and confirmed by quantitative parameters related to skin color, melanin content and melanocyte numbers. These data confirmed the responsiveness of the model and demonstrated that dermal fibroblasts do indeed impact the degree of skin pigmentation. We then hypothesized that a physiological state associated with pigmentary alterations such as photo-aging could be linked to dermal fibroblasts modifications that accumulate over time. Pigmentation of skin reconstructed using young unexposed fibroblasts (n = 3 was compared to that of tissues containing natural photo-aged fibroblasts (n = 3 which express a senescent phenotype. A stimulation of pigmentation in the presence of the natural photo-aged fibroblasts was revealed by a significant increase in the skin color (decrease in Luminance and an increase in both epidermal melanin content and melanogenic gene expression, thus confirming our hypothesis. Altogether, these data demonstrate that the level of pigmentation of the skin model is influenced by dermal fibroblasts and that natural photo-aged fibroblasts can contribute to the

  8. Targeted Disruption of Melanin Biosynthesis Genes in the Human Pathogenic Fungus Lomentospora prolificans and Its Consequences for Pathogen Survival

    Directory of Open Access Journals (Sweden)

    Ayat Al-Laaeiby

    2016-03-01

    Full Text Available The dematiaceous (melanised fungus Lomentospora (Scedosporium prolificans is a life-threatening opportunistic pathogen of immunocompromised humans, resistant to anti-fungal drugs. Melanin has been shown to protect human pathogenic fungi against antifungal drugs, oxidative killing and environmental stresses. To determine the protective role of melanin in L. prolificans to oxidative killing (H2O2, UV radiation and the polyene anti-fungal drug amphotericin B, targeted gene disruption was used to generate mutants of the pathogen lacking the dihydroxynaphthalene (DHN-melanin biosynthetic enzymes polyketide synthase (PKS1, tetrahydroxynapthalene reductase (4HNR and scytalone dehydratase (SCD1. Infectious propagules (spores of the wild-type strain 3.1 were black/brown, whereas spores of the PKS-deficient mutant ΔLppks1::hph were white. Complementation of the albino mutant ΔLppks1::hph restored the black-brown spore pigmentation, while the 4HNR-deficient mutant ΔLp4hnr::hph and SCD-deficient mutant ΔLpscd1::hph both produced orange-yellow spores. The mutants ΔLppks1::hph and ΔLp4hnr::hph showed significant reductions in spore survival following H2O2 treatment, while spores of ΔLpscd1::hph and the ΔLppks1::hph complemented strain ΔLppks1::hph:PKS showed spore survivals similar to strain 3.1. Spores of the mutants ΔLp4hnr::hph and ΔLpscd1::hph and complemented strain ΔLppks1::hph:PKS showed spore survivals similar to 3.1 following exposure to UV radiation, but survival of ΔLppks1::hph spores was significantly reduced compared to the wild-type strain. Strain 3.1 and mutants ΔLp4hnr::hph and ΔLppks1::hph:PKS were resistant to amphotericin B while, paradoxically, the PKS1- and SCD1-deficient mutants showed significant increases in growth in the presence of the antifungal drug. Taken together, these results show that while melanin plays a protective role in the survival of the pathogen to oxidative killing and UV radiation, melanin does not

  9. Targeted Disruption of Melanin Biosynthesis Genes in the Human Pathogenic Fungus Lomentospora prolificans and Its Consequences for Pathogen Survival.

    Science.gov (United States)

    Al-Laaeiby, Ayat; Kershaw, Michael J; Penn, Tina J; Thornton, Christopher R

    2016-03-24

    The dematiaceous (melanised) fungus Lomentospora (Scedosporium) prolificans is a life-threatening opportunistic pathogen of immunocompromised humans, resistant to anti-fungal drugs. Melanin has been shown to protect human pathogenic fungi against antifungal drugs, oxidative killing and environmental stresses. To determine the protective role of melanin in L. prolificans to oxidative killing (H₂O₂), UV radiation and the polyene anti-fungal drug amphotericin B, targeted gene disruption was used to generate mutants of the pathogen lacking the dihydroxynaphthalene (DHN)-melanin biosynthetic enzymes polyketide synthase (PKS1), tetrahydroxynapthalene reductase (4HNR) and scytalone dehydratase (SCD1). Infectious propagules (spores) of the wild-type strain 3.1 were black/brown, whereas spores of the PKS-deficient mutant ΔLppks1::hph were white. Complementation of the albino mutant ΔLppks1::hph restored the black-brown spore pigmentation, while the 4HNR-deficient mutant ΔLp4hnr::hph and SCD-deficient mutant ΔLpscd1::hph both produced orange-yellow spores. The mutants ΔLppks1::hph and ΔLp4hnr::hph showed significant reductions in spore survival following H₂O₂ treatment, while spores of ΔLpscd1::hph and the ΔLppks1::hph complemented strain ΔLppks1::hph:PKS showed spore survivals similar to strain 3.1. Spores of the mutants ΔLp4hnr::hph and ΔLpscd1::hph and complemented strain ΔLppks1::hph:PKS showed spore survivals similar to 3.1 following exposure to UV radiation, but survival of ΔLppks1::hph spores was significantly reduced compared to the wild-type strain. Strain 3.1 and mutants ΔLp4hnr::hph and ΔLppks1::hph:PKS were resistant to amphotericin B while, paradoxically, the PKS1- and SCD1-deficient mutants showed significant increases in growth in the presence of the antifungal drug. Taken together, these results show that while melanin plays a protective role in the survival of the pathogen to oxidative killing and UV radiation, melanin does not

  10. 维生素对黑色素代谢的影响%Effects of Vitamins on Melanin Metabolism

    Institute of Scientific and Technical Information of China (English)

    李虎; 刘志军

    2013-01-01

      黑色素是人及动物皮肤或者毛发中存在的一种黑褐色的生物色素,是皮肤为避免受紫外线等的伤害而自行产生的一种保护性色素。遗传易感性、过度暴露在阳光下以及其他来源的紫外线均会破坏皮肤的抗氧化能力,影响黑素细胞合成黑素颗粒,引起皮肤色素相关疾病。现有研究表明皮肤中的抗氧化因子能有效保护机体免受紫外线的危害,维生素作为抗氧化物质已广泛应用于临床,本文概述了维生素B、维生素E、维生素C和维生素D等抗氧化维生素通过不同的抗氧化机制影响着黑色素代谢而应用于皮肤色素相关疾病的治疗,以期为维生素治疗色素疾病提供理论依据。%Melanin is a dark brown biological pigment which exists in human skin or hair, also in animal;protect the damage of UV rays. Genetic susceptibility, excessive exposure to sun’s rays and other sources of ultraviolet ray will damage the skin antioxidant capacity of the skin,then influence the melanin granules of melanocyte, cause pigment related skin diseases. Recent studies show that skin antioxidant factor can effectively protect the body from harmful UV rays, vitamins as antioxidants have been widely used in clinical practice. This article provides an overview of the antioxidant vitamins, including vitamin B, vitamin E, vitamin C and vitamin D, which affect the metabolism of melanin through different anti-oxidation mechanisms,and applied to the skin pigment disease treatment, in the hope of providing theoretical basis for the treatment of pigmentary disorders with vitamins.

  11. Melanin Made by Dopamine Oxidation: Thin Films and Interactions with Polyelectrolyte Multilayers

    OpenAIRE

    Bernsmann, Falk

    2014-01-01

    The spontaneous oxidation of dopamine in slightly alkaline solutions was investigated on the basis of the work of Lee and others [Science, 318:426-430, 2007], and the reaction product was identified as dopamine-melanin. The ability of melanin to covalently bind amine functional groups was confirmed by quantification of the corresponding binding sites on dopamine-melanin aggregates. Furthermore it is possible to redissolve dopamine-melanin aggregates in strongly alkaline solutions. The obtaine...

  12. Smoke Priming, a Potent Protective Agent Against Salinity: Effect on Proline Accumulation, Elemental Uptake, Pigmental Attributes and Protein Banding Patterns of Rice (Oryza Sativa

    Directory of Open Access Journals (Sweden)

    Jamil, Muhammad

    2013-02-01

    Full Text Available The exogenous application of plant derived smoke solution through seed pre treatment is consider to create tolerance in the plant against salinity, for this purpose different dilution of plant derived smoke solution as 1:5000 Buhania, 1:1000 Buhania, 1:1000 Cymbopogon, 1:500 Cymbopogon were used against 0 mM, 50, 100 and 150mM NaCl solution in the medium. The effect was observed on total proline accumulation, heavy metals uptake, photosynthetic pigments and protein polypeptide bands intensity in two rice varieties as Basmati 385 (B-385 and Shaheen Basmati (S. Basmati. Proline concentration increases while chlorophyll “a” chlorophyll “b” and carotene level decreases with increasing salinity. On other hand zinc concentration increases while cadmium and lead concentration decrease in the crop under saline conditions. Intensity of protein polypeptides bands decreases gradually with increasing salinity level but plants from the seeds soaked with smoke solution alleviate the drastic affect of salinity, and intensity of bands is quite good by comparing with non primed seeds. It is concluded that seed priming with plant derived smoke solution show beneficial effect on crop to protect them from salinity.

  13. Melanisation of Aspergillus terreus—Is Butyrolactone I Involved in the Regulation of Both DOPA and DHN Types of Pigments in Submerged Culture?

    Directory of Open Access Journals (Sweden)

    Elina K. Palonen

    2017-05-01

    Full Text Available Pigments and melanins of fungal spores have been investigated for decades, revealing important roles in the survival of the fungus in hostile environments. The key genes and the encoded enzymes for pigment and melanin biosynthesis have recently been found in Ascomycota, including Aspergillus spp. In Aspergillus terreus, the pigmentation has remained mysterious with only one class of melanin biogenesis being found. In this study, we examined an intriguing, partially annotated gene cluster of A. terreus strain NIH2624, utilizing previously sequenced transcriptome and improved gene expression data of strain MUCL 38669, under the influence of a suggested quorum sensing inducing metabolite, butyrolactone I. The core polyketide synthase (PKS gene of the cluster was predicted to be significantly longer on the basis of the obtained transcriptional data, and the surrounding cluster was positively regulated by butyrolactone I at the late growth phase of submerged culture, presumably during sporulation. Phylogenetic analysis of the extended PKS revealed remarkable similarity with a group of known pigments of Fusarium spp., indicating a similar function for this PKS. We present a hypothesis of this PKS cluster to biosynthesise a 1,8-dihydroxynaphthalene (DHN-type of pigment during sporulation with the influence of butyrolactone I under submerged culture.

  14. Sunscreening fungal pigments influence the vertical gradient of pendulous lichens in boreal forest canopies.

    Science.gov (United States)

    Färber, Leonie; Sølhaug, Knut Asbjorn; Esseen, Per-Anders; Bilger, Wolfgang; Gauslaa, Yngvar

    2014-06-01

    Pendulous lichens dominate canopies of boreal forests, with dark Bryoria species in the upper canopy vs. light Alectoria and Usnea species in lower canopy. These genera offer important ecosystem services such as winter forage for reindeer and caribou. The mechanism behind this niche separation is poorly understood. We tested the hypothesis that species-specific sunscreening fungal pigments protect underlying symbiotic algae differently against high light, and thus shape the vertical canopy gradient of epiphytes. Three pale species with the reflecting pigment usnic acid (Alectoria sarmentosa, Usnea dasypoga, U. longissima) and three with dark, absorbing melanins (Bryoria capillaris, B. fremontii, B. fuscescens) were compared. We subjected the lichens to desiccation stress with and without light, and assessed their performance with chlorophyll fluorescence. Desiccation alone only affected U. longissima. By contrast, light in combination with desiccation caused photoinhibitory damage in all species. Usnic lichens were significantly more susceptible to light during desiccation than melanic ones. Thus, melanin is a more efficient light-screening pigment than usnic acid. Thereby, the vertical gradient of pendulous lichens in forest canopies is consistent with a shift in type and functioning of sunscreening pigments, from high-light-tolerant Bryoria in the upper to susceptible Alectoria and Usnea in the lower canopy.

  15. Photoacoustic discrimination of vascular and pigmented lesions using classical and Bayesian methods

    Science.gov (United States)

    Swearingen, Jennifer A.; Holan, Scott H.; Feldman, Mary M.; Viator, John A.

    2010-01-01

    Discrimination of pigmented and vascular lesions in skin can be difficult due to factors such as size, subungual location, and the nature of lesions containing both melanin and vascularity. Misdiagnosis may lead to precancerous or cancerous lesions not receiving proper medical care. To aid in the rapid and accurate diagnosis of such pathologies, we develop a photoacoustic system to determine the nature of skin lesions in vivo. By irradiating skin with two laser wavelengths, 422 and 530 nm, we induce photoacoustic responses, and the relative response at these two wavelengths indicates whether the lesion is pigmented or vascular. This response is due to the distinct absorption spectrum of melanin and hemoglobin. In particular, pigmented lesions have ratios of photoacoustic amplitudes of approximately 1.4 to 1 at the two wavelengths, while vascular lesions have ratios of about 4.0 to 1. Furthermore, we consider two statistical methods for conducting classification of lesions: standard multivariate analysis classification techniques and a Bayesian-model-based approach. We study 15 human subjects with eight vascular and seven pigmented lesions. Using the classical method, we achieve a perfect classification rate, while the Bayesian approach has an error rate of 20%.

  16. Comparative Methods to Improve the Detection of BRAF V600 Mutations in Highly Pigmented Melanoma Specimens.

    Science.gov (United States)

    Frouin, Eric; Maudelonde, Thierry; Senal, Romain; Larrieux, Marion; Costes, Valérie; Godreuil, Sylvain; Vendrell, Julie A; Solassol, Jérôme

    2016-01-01

    Genotyping BRAF in melanoma samples is often challenging. The presence of melanin greatly interferes with thermostable DNA polymerases and/or nucleic acids in traditional polymerase chain reaction (PCR)-based methods. In the present work, we evaluated three easy-to-use strategies to improve the detection of pigmented DNA refractory to PCR amplification. These pre-PCR processing methods include the addition of bovine serum albumin (BSA), the dilution of DNA, and the purification of DNA using the NucleoSpin® gDNA Clean-up XS Kit. We found that BRAF genotyping in weakly and moderately pigmented samples was more efficient when the sample was processed with BSA or purified with a NucleoSpin® gDNA Clean-up XS Kit prior to PCR amplification. In addition, the combination of both methods resulted in successful detection of BRAF mutation in pigmented specimens, including highly pigmented samples, thereby increasing the chance of patients being elicited for anti-BRAF treatment. These solutions to overcome melanin-induced PCR inhibition are of tremendous value and provide a simple solution for clinical chemistry and routine laboratory medicine.

  17. Melanin determination by high performance liquid chromatography (HPLC) for K. marxianus

    Science.gov (United States)

    Ultraviolet light (UV) mutated K. marxianus was found to turn dark brown during a growth assay. This brown color was hypothesized to be melanin overproduction influenced by the UV exposure. Cell cultures were oxidized and HPLC analyzed to determine melanin concentrations. The resulting melanin con...

  18. Abnormal pigmentation within cutaneous scars: A complication of wound healing

    Directory of Open Access Journals (Sweden)

    Sarah Chadwick

    2012-01-01

    Full Text Available Abnormally pigmented scars are an undesirable consequence of cutaneous wound healing and are a complication every single individual worldwide is at risk of. They present a challenge for clinicians, as there are currently no definitive treatment options available, and render scars much more noticeable making them highly distressing for patients. Despite extensive research into both wound healing and the pigment cell, there remains a scarcity of knowledge surrounding the repigmentation of cutaneous scars. Pigment production is complex and under the control of many extrinsic and intrinsic factors and patterns of scar repigmentation are unpredictable. This article gives an overview of human skin pigmentation, repigmentation following wounding and current treatment options.

  19. Transcriptome analysis of integument differentially expressed genes in the pigment mutant (quail) during molting of silkworm, Bombyx mori.

    Science.gov (United States)

    Nie, Hongyi; Liu, Chun; Cheng, Tingcai; Li, Qiongyan; Wu, Yuqian; Zhou, Mengting; Zhang, Yinxia; Xia, Qingyou

    2014-01-01

    In the silkworm Bombyx mori, pigment mutants with diverse body colors have been maintained throughout domestication for about 5000 years. The silkworm larval body color is formed through the mutual interaction of melanin, ommochromes, pteridines and uric acid. These pigments/compounds are synthesized by the cooperative action of various genes and enzymes. Previous reports showed that melanin, ommochrome and pteridine are increased in silkworm quail (q) mutants. To understand the pigment increase and alterations in pigment synthesis in q mutant, transcriptome profiles of the silkworm integument were investigated at 16 h after head capsule slippage in the fourth molt in q mutants and wild-type (Dazao). Compared to the wild-type, 1161 genes were differentially expressed in the q mutant. Of these modulated genes, 62.4% (725 genes) were upregulated and 37.6% (436 genes) were downregulated in the q mutant. The molecular function of differently expressed genes was analyzed by Blast2GO. The results showed that upregulated genes were mainly involved in protein binding, small molecule binding, transferase activity, nucleic acid binding, specific DNA-binding transcription factor activity and chromatin binding, while exclusively down-expressed genes functioned in oxidoreductase activity, cofactor binding, tetrapyrrole binding, peroxidase activity and pigment binding. We focused on genes related to melanin, pteridine and ommochrome biosynthesis; transport of uric acid; and juvenile hormone metabolism because of their importance in integument coloration during molting. This study identified differently expressed genes implicated in silkworm integument formation and pigmentation using silkworm q mutant. The results estimated the number and types of genes that drive new integument formation.

  20. Characterization of the mantle transcriptome of yesso scallop (Patinopecten yessoensis): identification of genes potentially involved in biomineralization and pigmentation.

    Science.gov (United States)

    Sun, Xiujun; Yang, Aiguo; Wu, Biao; Zhou, Liqing; Liu, Zhihong

    2015-01-01

    The Yesso scallop Patinopecten yessoensis is an economically important marine bivalve species in aquaculture and fishery in Asian countries. However, limited genomic resources are available for this scallop, which hampers investigations into molecular mechanisms underlying their unique biological characteristics, such as shell formation and pigmentation. Mantle is the special tissue of P. yessoensis that secretes biomineralization proteins inducing shell deposition as well as pigmentation on the shells. However, a current deficiency of transcriptome information limits insight into mechanisms of shell formation and pigmentation in this species. In this study, the transcriptome of the mantle of P. yessoensis was deeply sequenced and characterized using Illumina RNA-seq technology. A total of 86,521 unique transcripts are assembled from 55,884,122 reads that passed quality filters, and annotated, using Gene Ontology classification. A total of 259 pathways are identified in the mantle transcriptome, including the calcium signaling and melanogenesis pathways. A total of 237 unigenes that are homologous to 102 reported biomineralization genes are identified, and 121 unigenes that are homologous to 93 known proteins related to melanin biosynthesis are found. Twenty-three annotated unigenes, which are mainly homologous to calmodulin and related proteins, Ca2+/calmodulin-dependent protein kinase, adenylate/guanylate cyclase, and tyrosinase family are potentially involved in both biomineralization and melanin biosynthesis. It is suggested that these genes are probably not limited in function to induce shell deposition by calcium metabolism, but may also be involved in pigmentation of the shells of the scallop. This potentially supports the idea that there might be a link between calcium metabolism and melanin biosynthesis, which was previously found in vertebrates. The findings presented here will notably advance the understanding of the sophisticated processes of shell

  1. Pigments in Thermophilic fungi

    OpenAIRE

    Somasundaram, T.; Rao, Sanjay SR; Maheshwari,R.

    1986-01-01

    UV and visible absorption spectra of thermophilic fungi were obtained by photoacoustic spectroscopy. Based on these data as well as on the chem. properties and IR spectra, it is suggested that the pigments may be hydroxylated polycyclic quinones.

  2. Incorporation of codeine and metabolites into hair. Role of pigmentation.

    Science.gov (United States)

    Gygi, S P; Joseph, R E; Cone, E J; Wilkins, D G; Rollins, D E

    1996-04-01

    Xenobiotics circulating in the blood may become incorporated into growing hair. Melanin has affinity for many pharmacologically unrelated drugs and is responsible for the pigmentation in hair. To assess the role of pigmentation in the incorporation of drugs into hair, the distribution of codeine and its metabolites was studied in Sprague-Dawley (SD; white nonpigmented hair), Dark Agouti (DA; brown pigmented hair), and hooded Long-Evans (LE; both black pigmented and white nonpigmented hair) rats. Codeine was administered at a dose of 40 mg/kg/day i.p. for 5 days. Fourteen days after beginning the dosing protocol, hair was collected and analyzed for codeine, and its metabolite, morphine, by positive-ion chemical ionization GC/ion-trap MS. The plasma pharmacokinetics for codeine and morphine were also determined after a single 40 mg/kg injection (equivalent to first dose in 5-day dosing protocol) in all three strains of rats. Hair and plasma codeine and morphine concentrations were also determined after acid hydrolysis to evaluate the presence of glucuronide metabolites. Codeine concentrations in the hair of SD, DA, and pigmented LE hair were 0.98 +/- 0.10, 5.99 +/- 1.24, and 111.93 +/- 18.69 ng/mg hair, respectively; morphine concentrations were 0.34 +/- 0.04, 0.51 +/- 0.11, and 14.46 +/- 1.81 ng/mg hair, respectively; morphine glucuronide concentrations were 0.67 +/- 0.08, 1.04 +/- 0.37, and 13.80 +/- 3.60 ng/mg hair, respectively. Studies examining the in vitro binding of [3H] codeine and [3H]morphine to hair demonstrated both specific and nonspecific binding sites for codeine and morphine. Pigmented hair from LE rats possessed the greatest number of binding sites, white hair from SD rats contained the least, and brown hair from DA rats was intermediate. A time course study of codeine and its metabolites showed pigment-mediated differences in incorporation of codeine and metabolites within a few hours of drug administration. These data indicate that pigmented hair

  3. Mathematical modeling predicts enhanced growth of X-ray irradiated pigmented fungi.

    Directory of Open Access Journals (Sweden)

    Igor Shuryak

    Full Text Available Ionizing radiation is known for its cytotoxic and mutagenic properties. However, recent evidence suggests that chronic sub-lethal irradiation stimulates the growth of melanin-pigmented (melanized fungi, supporting the hypothesis that interactions between melanin and ionizing photons generate energy useful for fungal growth, and/or regulate growth-promoting genes. There are no quantitative models of how fungal proliferation is affected by ionizing photon energy, dose rate, and presence versus absence of melanin on the same genetic background. Here we present such a model, which we test using experimental data on melanin-modulated radiation-induced proliferation enhancement in the fungus Cryptococcus neoformans, exposed to two different peak energies (150 and 320 kVp over a wide range of X-ray dose rates. Our analysis demonstrates that radiation-induced proliferation enhancement in C. neoformans behaves as a binary "on/off" phenomenon, which is triggered by dose rates 5000 mGy/h. Proliferation enhancement of irradiated cells compared with unirradiated controls occurs at both X-ray peak energies, but its magnitude is modulated by X-ray peak energy and cell melanization. At dose rates <5000 mGy/h, both melanized and non-melanized cells exposed to 150 kVp X-rays, and non-melanized cells exposed to 320 kVp X-rays, all exhibit the same proliferation enhancement: on average, chronic irradiation stimulates each founder cell to produce 100 (95% CI: 83, 116 extra descendants over 48 hours. Interactions between melanin and 320 kVp X-rays result in a significant (2-tailed p-value = 4.8 × 10(-5 additional increase in the number of radiation-induced descendants per founder cell: by 55 (95% CI: 29, 81. These results show that both melanin-dependent and melanin-independent mechanisms are involved in radiation-induced fungal growth enhancement, and implicate direct and/or indirect interactions of melanin with high energy ionizing photons as an important pro

  4. Photosynthetic Pigments in Diatoms

    OpenAIRE

    Paulina Kuczynska; Malgorzata Jemiola-Rzeminska; Kazimierz Strzalka

    2015-01-01

    Photosynthetic pigments are bioactive compounds of great importance for the food, cosmetic, and pharmaceutical industries. They are not only responsible for capturing solar energy to carry out photosynthesis, but also play a role in photoprotective processes and display antioxidant activity, all of which contribute to effective biomass and oxygen production. Diatoms are organisms of a distinct pigment composition, substantially different from that present in plants. Apart from light-harvestin...

  5. diversion of the melanin synthetic pathway by dopamine product ...

    African Journals Online (AJOL)

    Studies have been reported about the physiological regulation of the ... However, the understanding of how melanin synthesis is regulated in the human body still needs ... conditions for temperature (298.15 K) and pressure (1.00 atm) using ...

  6. Photosynthetic Pigments in Diatoms

    Directory of Open Access Journals (Sweden)

    Paulina Kuczynska

    2015-09-01

    Full Text Available Photosynthetic pigments are bioactive compounds of great importance for the food, cosmetic, and pharmaceutical industries. They are not only responsible for capturing solar energy to carry out photosynthesis, but also play a role in photoprotective processes and display antioxidant activity, all of which contribute to effective biomass and oxygen production. Diatoms are organisms of a distinct pigment composition, substantially different from that present in plants. Apart from light-harvesting pigments such as chlorophyll a, chlorophyll c, and fucoxanthin, there is a group of photoprotective carotenoids which includes β-carotene and the xanthophylls, diatoxanthin, diadinoxanthin, violaxanthin, antheraxanthin, and zeaxanthin, which are engaged in the xanthophyll cycle. Additionally, some intermediate products of biosynthetic pathways have been identified in diatoms as well as unusual pigments, e.g., marennine. Marine algae have become widely recognized as a source of unique bioactive compounds for potential industrial, pharmaceutical, and medical applications. In this review, we summarize current knowledge on diatom photosynthetic pigments complemented by some new insights regarding their physico-chemical properties, biological role, and biosynthetic pathways, as well as the regulation of pigment level in the cell, methods of purification, and significance in industries.

  7. Development of melanocye-keratinocyte co-culture model for controls and vitiligo to assess regulators of pigmentation and melanocytes

    Directory of Open Access Journals (Sweden)

    Ravinder Kumar

    2012-01-01

    Full Text Available Background: There is a need to develop an in vitro skin models which can be used as alternative system for research and testing pharmacological products in place of laboratory animals. Therefore to study the biology and pathophysiology of pigmentation and vitiligo, reliable in vitro skin pigmentation models are required. Aim: In this study, we used primary cultured melanocytes and keratinocytes to prepare the skin co-culture model in control and vitiligo patients. Methods: The skin grafts were taken from control and patients of vitiligo. In vitro co-culture was prepared after culturing primary melanocytes and keratinocytes. Co- cultures were treated with melanogenic stimulators and inhibitors and after that tyrosinase assay, MTT assay and melanin content assay were performed. Results: Melanocytes and keratinocytes were successfully cultured from control and vitiligo patients and after that co-culture models were prepared. After treatment of co-culture model with melanogenic stimulator we found that tyrosinase activity, cell proliferation and melanin content increased whereas after treatment with melanogenic inhibitor, tyrosinase activity, cell proliferation and melanin content decreased. We also found some differences in the control co-culture model and vitiligo co-culture model. Conclusion: We successfully constructed in vitro co-culture pigmentation model for control and vitiligo patients using primary cultured melanocytes and keratinocytes. The use of primary melanocytes and keratinocytes is more appropriate over the use of transformed cells. The only limitation of these models is that these can be used for screening small numbers of compounds.

  8. The metabolism and influence factors of skin melanin%皮肤黑素的代谢及其影响因素

    Institute of Scientific and Technical Information of China (English)

    王娟; 马慧群

    2011-01-01

    人类皮肤颜色的各种差异与黑素细胞中黑素小体的数目、大小、类型和分布有着直接的关系.黑素的合成及其在细胞内的转运是非常复杂而精确的过程,该过程决定皮肤色素的分布与沉着.有诸多因素影响着黑素的代谢,目前研究较多的有酪氨酸酶、过氧化物酶、微量元素、紫外线、结构蛋白Pmel 17和蛋白受体2等.%The skin color of human is diversity, there is a close relation between the quantity, magnitude, type, distribution of melanosome in melanocytes. The synthesis of melanin and the intercellular transportation of melanin are complicated which as a precise process determines the distribution and skin pigmentation. There are many factors influencing the metabolism of skin melanin, such as tyrosinase, peroxidase, microelement, ultraviolet rays, structural proteins 17 and protein receptor 2.

  9. DHN melanin biosynthesis in the plant pathogenic fungus Botrytis cinerea is based on two developmentally regulated key enzyme (PKS)-encoding genes.

    Science.gov (United States)

    Schumacher, Julia

    2016-02-01

    Botrytis cinerea is the causal agent of gray mold disease in various plant species and produces grayish macroconidia and/or black sclerotia at the end of the infection cycle. It has been suggested that the pigmentation is due to the accumulation of 1,8-dihydroxynaphthalene (DHN) melanin. To unravel its basis and regulation, the putative melanogenic and regulatory genes were identified and functionally characterized. Unlike other DHN melanin-producing fungi, B. cinerea and other Leotiomycetes contain two key enzyme (PKS)-encoding enzymes. Bcpks12 and bcpks13 are developmentally regulated and are required for melanogenesis in sclerotia and conidia respectively. BcYGH1 converts the BcPKS13 product and contributes thereby to conidial melanogenesis. In contrast, enzymes acting downstream in conversion of the PKS products (BcBRN2, BcSCD1 and BcBRN1) are required for both, sclerotial and conidial melanogenesis, suggesting that DHN melanogenesis in B. cinerea follows a non-linear pathway that is rather unusual for secondary metabolic pathways. Regulation of the melanogenic genes involves three pathway-specific transcription factors (TFs) that are clustered with bcpks12 or bcpks13 and other developmental regulators such as light-responsive TFs. Melanogenic genes are dispensable in vegetative mycelia for proper growth and virulence. However, DHN melanin is considered to contribute to the longevity of the reproduction structures.

  10. Roles of reactive oxygen species in UVA-induced oxidation of 5,6-dihydroxyindole-2-carboxylic acid-melanin as studied by differential spectrophotometric method.

    Science.gov (United States)

    Ito, Shosuke; Kikuta, Marina; Koike, Shota; Szewczyk, Grzegorz; Sarna, Michal; Zadlo, Andrzej; Sarna, Tadeusz; Wakamatsu, Kazumasa

    2016-05-01

    Eumelanin photoprotects pigmented tissues from ultraviolet (UV) damage. However, UVA-induced tanning seems to result from the photooxidation of preexisting melanin and does not contribute to photoprotection. We investigated the mechanism of UVA-induced degradation of 5,6-dihydroxyindole-2-carboxylic acid (DHICA)-melanin taking advantage of its solubility in a neutral buffer and using a differential spectrophotometric method to detect subtle changes in its structure. Our methodology is suitable for examining the effects of various agents that interact with reactive oxygen species (ROS) to determine how ROS is involved in the UVA-induced oxidative modifications. The results show that UVA radiation induces the oxidation of DHICA to indole-5,6-quinone-2-carboxylic acid in eumelanin, which is then cleaved to form a photodegraded, pyrrolic moiety and finally to form free pyrrole-2,3,5-tricarboxylic acid. The possible involvement of superoxide radical and singlet oxygen in the oxidation was suggested. The generation and quenching of singlet oxygen by DHICA-melanin was confirmed by direct measurements of singlet oxygen phosphorescence.

  11. Paraquat-Melanin Redox-Cycling: Evidence from Electrochemical Reverse Engineering.

    Science.gov (United States)

    Kim, Eunkyoung; Leverage, W Taylor; Liu, Yi; Panzella, Lucia; Alfieri, Maria Laura; Napolitano, Alessandra; Bentley, William E; Payne, Gregory F

    2016-08-17

    Parkinson's disease is a neurodegenerative disorder associated with oxidative stress and the death of melanin-containing neurons of the substantia nigra. Epidemiological evidence links exposure to the pesticide paraquat (PQ) to Parkinson's disease, and this link has been explained by a redox cycling mechanism that induces oxidative stress. Here, we used a novel electrochemistry-based reverse engineering methodology to test the hypothesis that PQ can undergo reductive redox cycling with melanin. In this method, (i) an insoluble natural melanin (from Sepia melanin) and a synthetic model melanin (having a cysteinyldopamine-melanin core and dopamine-melanin shell) were entrapped in a nonconducting hydrogel film adjacent to an electrode, (ii) the film-coated electrode was immersed in solutions containing PQ (putative redox cycling reductant) and a redox cycling oxidant (ferrocene dimethanol), (iii) sequences of input potentials (i.e., voltages) were imposed to the underlying electrode to systematically engage reductive and oxidative redox cycling, and (iv) output response currents were analyzed for signatures of redox cycling. The response characteristics of the PQ-melanin systems to various input potential sequences support the hypothesis that PQ can directly donate electrons to melanin. This observation of PQ-melanin redox interactions demonstrates an association between two components that have been individually linked to oxidative stress and Parkinson's disease. Potentially, melanin's redox activity could be an important component in understanding the etiology of neurological disorders such as Parkinson's disease.

  12. Characters of homogentisate oxygenase gene mutation and high clonality of the natural pigment-producing Vibrio cholerae strains

    Directory of Open Access Journals (Sweden)

    Diao Baowei

    2011-05-01

    Full Text Available Abstract Background Some microorganisms can produce pigments such as melanin, which has been associated with virulence in the host and with a survival advantage in the environment. In Vibrio cholerae, studies have shown that pigment-producing mutants are more virulent than the parental strain in terms of increased UV resistance, production of major virulence factors, and colonization. To date, almost all of the pigmented V. cholerae strains investigated have been induced by chemicals, culture stress, or transposon mutagenesis. However, during our cholera surveillance, some nontoxigenic serogroup O139 strains and one toxigenic O1 strain, which can produce pigment steadily under the commonly used experimental growth conditions, were obtained in different years and from different areas. The genes VC1344 to VC1347, which correspond to the El Tor strain N16961 genome and which comprise an operon in the tyrosine catabolic pathway, have been confirmed to be associated with a pigmented phenotype. In the present study, we investigated the mechanism of pigment production in these strains. Results Sequencing of the VC1344, VC1345, VC1346, and VC1347 genes in these pigmented strains suggested that a deletion mutation in the homogentisate oxygenase gene (VC1345 may be associated with the pigmented phenotype, and gene complementation confirmed the role of this gene in pigment production. An identical 15-bp deletion was found in the VC1345 gene of all six O139 pigment-producing strains examined, and a 10-bp deletion was found in the VC1345 gene of the O1 strain. Strict sequence conservation in the VC1344 gene but higher variance in the other three genes of this operon were observed, indicating the different stress response functions of these genes in environmental adaption and selection. On the basis of pulsed-field gel electrophoresis typing, the pigment-producing O139 strains showed high clonality, even though they were isolated in different years and from

  13. N-Nicotinoyl dopamine, a novel niacinamide derivative, retains high antioxidant activity and inhibits skin pigmentation.

    Science.gov (United States)

    Kim, Bora; Kim, Jin Eun; Lee, Su Min; Lee, Soung-Hoon; Lee, Jin Won; Kim, Myung Kyoo; Lee, Kye Jong; Kim, Hyuk; Lee, Joo Dong; Choi, Kang-Yell

    2011-11-01

    We synthesized a novel derivative of a well-known skin-lightening compound niacinamide, N-nicotinoyl dopamine (NND). NND did not show inhibitory effects of tyrosinase and melanin synthesis in B16F10 mouse melanoma cells. However, NND retains high antioxidant activity without affecting viability of cells. In a reconstructed skin model, topical applications of 0.05% and 0.1% NND induced skin lightening and decreased melanin production without affecting the viability and morphology of melanocytes and overall tissue histology. Moreover, no evidence for skin irritation or sensitization was observed when 0.1% NND emulsion was applied onto the skin of 52 volunteers. The effect of NND on skin lightening was further revealed by pigmented spot analyses of human clinical trial. Overall, NND treatment may be a useful trial for skin lightening and treating pigmentary disorders.

  14. Cuticle formation and pigmentation in beetles.

    Science.gov (United States)

    Noh, Mi Young; Muthukrishnan, Subbaratnam; Kramer, Karl J; Arakane, Yasuyuki

    2016-10-01

    Adult beetles (Coleoptera) are covered primarily by a hard exoskeleton or cuticle. For example, the beetle elytron is a cuticle-rich highly modified forewing structure that shields the underlying hindwing and dorsal body surface from a variety of harmful environmental factors by acting as an armor plate. The elytron comes in a variety of colors and shapes depending on the coleopteran species. As in many other insect species, the cuticular tanning pathway begins with tyrosine and is responsible for production of a variety of melanin-like and other types of pigments. Tanning metabolism involves quinones and quinone methides, which also act as protein cross-linking agents for cuticle sclerotization. Electron microscopic analyses of rigid cuticles of the red flour beetle, Tribolium castaneum, have revealed not only numerous horizontal chitin-protein laminae but also vertically oriented columnar structures called pore canal fibers. This structural architecture together with tyrosine metabolism for cuticle tanning is likely to contribute to the rigidity and coloration of the beetle exoskeleton.

  15. Towards the development of a novel bioinspired functional material: Synthesis and characterization of hybrid TiO{sub 2}/DHICA-melanin nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Pezzella, Alessandro; Capelli, Luigia [Dept. of Chemical Sciences, Via Cintia 4, 80126 Napoli (Italy); Costantini, Aniello [Dept. of Materials and Production Engineering, Piazzale Tecchio 80, 80125 Napoli (Italy); Luciani, Giuseppina, E-mail: luciani@unina.it [Dept. of Materials and Production Engineering, Piazzale Tecchio 80, 80125 Napoli (Italy); Tescione, Fabiana; Silvestri, Brigida [Dept. of Materials and Production Engineering, Piazzale Tecchio 80, 80125 Napoli (Italy); Vitiello, Giuseppe [Dept. of Chemical Sciences, Via Cintia 4, 80126 Napoli (Italy); Branda, Francesco [Dept. of Materials and Production Engineering, Piazzale Tecchio 80, 80125 Napoli (Italy)

    2013-01-01

    A large number of recent literature data focus on modification/modulation of surface chemistry of inorganic materials in order to improve their functional properties. Melanins, a wide class of natural pigments, are recently emerging as a powerful organic component for developing bioinspired active material for a large number of applications from organoelectronics to bioactive compounds. Here we report the use of the approach referred as 'chimie douce', involving in situ formation of the hybrids through reactions of precursors under mild conditions, to prepare novel hybrid functional architectures based on eumelanin like 5,6 dihydroxyindole-2-carboxylic acid (DHICA) polymer and TiO{sub 2}. Two synthesis procedures were carried out to get DHICA-melanin coated TiO{sub 2} nanoparticles as well as mixed DHICA/TiO{sub 2} hybrid nanostructures. Such systems were characterized through EPR, FT-IR and fluorescence spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD), and TEM microscopy in order to assess the effect of synthesis path as well as of DHICA content on structural, morphological and optical properties of TiO{sub 2} nanostructures. In particular, EPR, FT-IR spectra and TGA analysis confirmed the presence of DHICA-melanin in these samples. TEM measurements indicated the formation of the nanoparticles having relatively narrow size distribution with average particle size of about 10 nm. DHICA-melanin does act as a morphological agent affecting morphology of hybrid nanostructures. XRD analysis proved that TiO{sub 2} hybrid nanoparticles kept anatase structures for DHICA-melanin contents within the range of investigated compositions, i.e. up to 50% wt/wt. - Highlights: Black-Right-Pointing-Pointer TiO{sub 2}/DHICA melanin blends are novel hybrid functional architectures. Black-Right-Pointing-Pointer Two synthetic approaches were explored to produce TiO{sub 2}/DHICA nanostructures. Black-Right-Pointing-Pointer TiO{sub 2} nanorods prepared

  16. HIV-Associated Oral Mucosal Melanin Hyperpigmentation: A Clinical Study in a South African Population Sample

    Directory of Open Access Journals (Sweden)

    R. Chandran

    2016-01-01

    Full Text Available Objective. The aim of the study was to determine the prevalence of HIV-associated oral mucosal melanin hyperpigmentation (HIV-OMH in a specific population of HIV-seropositive South Africans and to analyse the associations between HIV-OMH clinical features and the demographic and immunological characteristics of the study cohort. Material and Methods. This cross-sectional study included 200 HIV-seropositive Black subjects. The collected data comprised age, gender, CD4+ T cell count, viral load, systemic disease, medications, oral site affected by HIV-OMH, extent (localized or generalized, intensity of the pigmentation (dark or light, and smoking and snuff use. Results. Overall, 18.5% of the study cohort had HIV-OMH. Twenty-two and a half percent had OMH that could not with confidence be attributed to HIV infection, and 59% did not have any OMH. There was a significant but weak association between smoking and the presence of HIV-OMH. Conclusions. The prevalence of HIV-OMH in the study population was 18.5%, the gingiva being the most commonly affected site. It appears that the CD4+ T cell count does not play any role in the biopathology of HIV-OMH.

  17. Evaluation of the Relationship Between Passive Smoking and Oral Pigmentation in Children

    Directory of Open Access Journals (Sweden)

    F.Hajifattahi

    2010-09-01

    Full Text Available Introduction: Melanin pigmentation in the oral mucosa occurs as a result of several reasons one of which is smoking. Cigarette smoke induces numerous side effects in the people who do not smoke, but are in the same environment. The aim of this study was to evaluate the role of parental smoking on pigmentation of their children's oral mucosa.Materials and Methods: This study was carried out as a historical cohort. Participants were 400 healthy children, 10 to 11 years old who did not use any drugs. The passive smoker group included 200 children who at least one member in their family was a smoker. The control group included 200 children who did not have a smoker in their family. Furthermore, two groups were matched in the point of view of skin color. The children in the two groups were examined and oral pigmentation was recorded. Finally,the results were analyzed by the chi- square test.Results: Pigmentation was seen in 150 children (75% in the experimental group and 122 children (61% in the control group (P<0.005. The relative risk of oral pigmentation for children who were exposed to passive smoking was 1.23.Conclusion: Based on the results of this study, passive smoking can induce gingival pigmentation in children.

  18. Effects of a turmeric extract (Curcuma longa) on chronic ultraviolet B irradiation-induced skin damage in melanin-possessing hairless mice.

    Science.gov (United States)

    Sumiyoshi, Maho; Kimura, Yoshiyuki

    2009-12-01

    Turmeric (the rhizomes of Curcuma longa L., Zingiberacease) is widely used as a dietary pigment and spice, and has been traditionally used for the treatment of inflammation, skin wounds and hepatic disorders in Ayurvedic, Unani and Chinese medicine. Although the topical application or oral administration of turmeric is used to improve skin trouble, there is no evidence to support this effect. The aim of this study was to clarify whether turmeric prevents chronic ultraviolet B (UVB)-irradiated skin damage. We examined the effects of a turmeric extract on skin damage including changes in skin thickness and elasticity, pigmentation and wrinkling caused by long-term, low-dose ultraviolet B irradiation in melanin-possessing hairless mice. The extract (at 300 or 1000 mg/kg, twice daily) prevented an increase in skin thickness and a reduction in skin elasticity induced by chronic UVB exposure. It also prevented the formation of wrinkles and melanin (at 1000 mg/kg, twice daily) as well as increases in the diameter and length of skin blood vessels and in the expression of matrix metalloproteinase-2 (MMP-2). Prevention of UVB-induced skin aging by turmeric may be due to the inhibition of increases in MMP-2 expression caused by chronic irradiation.

  19. Melanin and Melanin-Related Polymers as Materials with Biomedical and Biotechnological Applications—Cuttlefish Ink and Mussel Foot Proteins as Inspired Biomolecules

    Directory of Open Access Journals (Sweden)

    Francisco Solano

    2017-07-01

    Full Text Available The huge development of bioengineering during the last years has boosted the search for new bioinspired materials, with tunable chemical, mechanical, and optoelectronic properties for the design of semiconductors, batteries, biosensors, imaging and therapy probes, adhesive hydrogels, tissue restoration, photoprotectors, etc. These new materials should complement or replace metallic or organic polymers that cause cytotoxicity and some adverse health effects. One of the most interesting biomaterials is melanin and synthetic melanin-related molecules. Melanin has a controversial molecular structure, dependent on the conditions of polymerization, and therefore tunable. It is found in animal hair and skin, although one of the common sources is cuttlefish (Sepia officinalis ink. On the other hand, mussels synthesize adhesive proteins to anchor these marine animals to wet surfaces. Both melanin and mussel foot proteins contain a high number of catecholic residues, and their properties are related to these groups. Dopamine (DA can easily polymerize to get polydopamine melanin (PDAM, that somehow shares properties with melanin and mussel proteins. Furthermore, PDAM can easily be conjugated with other components. This review accounts for the main aspects of melanin, as well as DA-based melanin-like materials, related to their biomedical and biotechnological applications.

  20. Melanin and Melanin-Related Polymers as Materials with Biomedical and Biotechnological Applications-Cuttlefish Ink and Mussel Foot Proteins as Inspired Biomolecules.

    Science.gov (United States)

    Solano, Francisco

    2017-07-18

    The huge development of bioengineering during the last years has boosted the search for new bioinspired materials, with tunable chemical, mechanical, and optoelectronic properties for the design of semiconductors, batteries, biosensors, imaging and therapy probes, adhesive hydrogels, tissue restoration, photoprotectors, etc. These new materials should complement or replace metallic or organic polymers that cause cytotoxicity and some adverse health effects. One of the most interesting biomaterials is melanin and synthetic melanin-related molecules. Melanin has a controversial molecular structure, dependent on the conditions of polymerization, and therefore tunable. It is found in animal hair and skin, although one of the common sources is cuttlefish (Sepia officinalis) ink. On the other hand, mussels synthesize adhesive proteins to anchor these marine animals to wet surfaces. Both melanin and mussel foot proteins contain a high number of catecholic residues, and their properties are related to these groups. Dopamine (DA) can easily polymerize to get polydopamine melanin (PDAM), that somehow shares properties with melanin and mussel proteins. Furthermore, PDAM can easily be conjugated with other components. This review accounts for the main aspects of melanin, as well as DA-based melanin-like materials, related to their biomedical and biotechnological applications.

  1. Detection of antibodies against Paracoccidioides brasiliensis melanin in in vitro and in vivo studies during infection.

    Science.gov (United States)

    Urán, Martha E; Nosanchuk, Joshua D; Restrepo, Angela; Hamilton, Andrew J; Gómez, Beatriz L; Cano, Luz E

    2011-10-01

    Several cell wall constituents, including melanins or melanin-like compounds, have been implicated in the pathogenesis of a wide variety of microbial diseases caused by diverse species of pathogenic bacteria, fungi, and helminthes. Among these microorganisms, the dimorphic fungal pathogen Paracoccidioides brasiliensis produces melanin in its conidial and yeast forms. In the present study, melanin particles from P. brasiliensis were injected into BALB/c mice in order to produce monoclonal antibodies (MAbs). We identified five immunoglobulin G1 (IgG1) κ-chain and four IgM melanin-binding MAbs. The five IgG1 κ-chain isotypes are the first melanin-binding IgG MAbs ever reported. The nine MAbs labeled P. brasiliensis conidia and yeast cells both in vitro and in pulmonary tissues. The MAbs cross-reacted with melanin-like purified particles from other fungi and also with commercial melanins, such as synthetic and Sepia officinalis melanin. Melanization during paracoccidioidomycosis (PCM) was also further supported by the detection of IgG antibodies reactive to melanin from P. brasiliensis conidia and yeast in sera and bronchoalveolar lavage fluids from P. brasiliensis-infected mice, as well as in sera from human patients with PCM. Serum specimens from patients with other mycoses were also tested for melanin-binding antibodies by enzyme-linked immunosorbent assay, and cross-reactivities were detected for melanin particles from different fungal sources. These results suggest that melanin from P. brasiliensis is an immunologically active fungal structure that activates a strong IgG humoral response in humans and mice.

  2. Murine and human b locus pigmentation genes encode a glycoprotein (gp75) with catalase activity

    Energy Technology Data Exchange (ETDEWEB)

    Halaban, R.; Moellmann, G. (Yale Univ. School of Medicine, New Haven, CT (USA))

    1990-06-01

    Melanogenesis is regulated in large part by tyrosinase, and defective tyrosinase leads to albinism. The mechanisms for other pigmentation determinants (e.g., those operative in tyrosinase-positive albinism and in murine coat-color mutants) are not yet known. One murine pigmentation gene, the brown (b) locus, when mutated leads to a brown (b/b) or hypopigmentated (B{sup lt}/B{sup lt}) coat versus the wild-type black (B/B). The authors show that the b locus codes for a glycoprotein with the activity of a catalase (catalase B). Only the c locus protein is a tyrosinase. Because peroxides may be by-products of melanogenic activity and hydrogen peroxide in particular is known to destroy melanin precursors and melanin, they conclude that pigmentation is controlled not only by tyrosinase but also by a hydroperoxidase. The studies indicate that catalase B is identical with gp75, a known human melanosomal glycoprotein; that the b mutation is in a heme-associated domain; and that the B{sup lt} mutation renders the protein susceptible to rapid proteolytic degradation.

  3. Seasonal Changes in Colour: A Comparison of Structural, Melanin- and Carotenoid-Based Plumage Colours

    Science.gov (United States)

    Delhey, Kaspar; Burger, Claudia; Fiedler, Wolfgang; Peters, Anne

    2010-01-01

    Background Plumage coloration is important for bird communication, most notably in sexual signalling. Colour is often considered a good quality indicator, and the expression of exaggerated colours may depend on individual condition during moult. After moult, plumage coloration has been deemed fixed due to the fact that feathers are dead structures. Still, many plumage colours change after moult, although whether this affects signalling has not been sufficiently assessed. Methodology/Principal Findings We studied changes in coloration after moult in four passerine birds (robin, Erithacus rubecula; blackbird, Turdus merula; blue tit, Cyanistes caeruleus; and great tit, Parus major) displaying various coloration types (melanin-, carotenoid-based and structural). Birds were caught regularly during three years to measure plumage reflectance. We used models of avian colour vision to derive two variables, one describing chromatic and the other achromatic variation over the year that can be compared in magnitude among different colour types. All studied plumage patches but one (yellow breast of the blue tit) showed significant chromatic changes over the year, although these were smaller than for a typical dynamic trait (bill colour). Overall, structural colours showed a reduction in relative reflectance at shorter wavelengths, carotenoid-based colours the opposite pattern, while no general pattern was found for melanin-based colours. Achromatic changes were also common, but there were no consistent patterns of change for the different types of colours. Conclusions/Significance Changes of plumage coloration independent of moult are probably widespread; they should be perceivable by birds and have the potential to affect colour signalling. PMID:20644723

  4. Laugier-hunziker pigmentation

    Directory of Open Access Journals (Sweden)

    Ajith C

    2005-01-01

    Full Text Available Laugier-Hunziker pigmentation (LHP is an acquired disorder of hypermelanosis characterized by mucocutaneous hyperpigmentation. LHP may resemble various disorders characterized by mucocutaneous pigmentation. A 58-year-old lady presented with progressively increasing number of variable sized, hyperpigmented macules over the lips, fingers, toes and nails. There was no family history of similar illness. Systemic examination and all relevant investigations were within normal limits. Histopathology of a skin lesion had features consistent with LHP. The diagnosis of LHP must be made only after relevant investigations to rule out any associated systemic involvement. This case further highlights that LHP is not restricted to European countries.

  5. Role of the Ubiquitin Proteasome System in Regulating Skin Pigmentation

    Directory of Open Access Journals (Sweden)

    Hideya Ando

    2009-10-01

    Full Text Available Pigmentation of the skin, hair and eyes is regulated by tyrosinase, the critical rate-limiting enzyme in melanin synthesis by melanocytes. Tyrosinase is degraded endogenously, at least in part, by the ubiquitin proteasome system (UPS. Several types of inherited hypopigmentary diseases, such as oculocutaneous albinism and Hermansky-Pudlak syndrome, involve the aberrant processing and/or trafficking of tyrosinase and its subsequent degradation which can occur due to the quality-control machinery. Studies on carbohydrate modifications have revealed that tyrosinase in the endoplasmic reticulum (ER is proteolyzed via ER-associated protein degradation and that tyrosinase degradation can also occur following its complete maturation in the Golgi. Among intrinsic factors that regulate the UPS, fatty acids have been shown to modulate tyrosinase degradation in contrasting manners through increased or decreased amounts of ubiquitinated tyrosinase that leads to its accelerated or decelerated degradation by proteasomes.

  6. Structure and Function of Iron-Loaded Synthetic Melanin

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yiwen; Xie, Yijun; Wang, Zhao; Zang, Nanzhi; Carniato, Fabio; Huang, Yuran; Andolina, Christopher M.; Parent, Lucas R.; Ditri, Treffly B.; Walter, Eric D.; Botta, Mauro; Rinehart, Jeffrey D.; Gianneschi, Nathan C.

    2016-11-22

    We describe a synthetic method for increasing and controlling the iron loading of synthetic melanin nanoparticles and use the resulting materials to perform a systematic quantitative investigation on their structure- property relationship. A comprehensive analysis by magnetometry, electron paramagnetic resonance, and nuclear magnetic relaxation dispersion reveals the complexities of their magnetic behavior and how these intraparticle magnetic interactions manifest in useful material properties such as their performance as MRI contrast agents. This analysis allows predictions of the optimal iron loading through a quantitative modeling of antiferromagnetic coupling that arises from proximal iron ions. This study provides a detailed understanding of this complex class of synthetic biomaterials and gives insight into interactions and structures prevalent in naturally occurring melanins.

  7. True bursal pigmented villonodular synovitis

    Energy Technology Data Exchange (ETDEWEB)

    Abdelwahab, Ibrahim Fikry [Department of Radiology, New York Methodist Hospital, Affiliated with New York Hospital-Cornell Medical Center, Brooklyn, NY (United States); Kenan, Samuel [Department of Orthopedics, New York University Medical Center, NY (United States); Steiner, German C. [Department of Pathology, Hospital for Joint Diseases/Orthopedic Institute, New York, NY (United States); Abdul-Quader, Mohammed [Department of Radiology, New York Presbyterian Hospital, Columbia University, New York, NY (United States)

    2002-06-01

    We describe two cases of pigmented villonodular synovitis affecting true bursae. This study was also designed to discuss the term ''pigmented villonodular bursitis'', not confined to true synovial bursae, sometimes creating misunderstanding. (orig.)

  8. Raman af hvide pigmenter

    DEFF Research Database (Denmark)

    Reeler, Nini Elisabeth Abildgaard; Nielsen, Ole Faurskov; Sauer, Stephan P. A.;

    2013-01-01

    Et samspil mellem kunst og kemi. I et samarbejde mellem Statens Museum for Kunst og Kemisk Institut på KU er Ramanspek-troskopi brugt til at definere sammensætningen af blandinger af blyhvidt og calcit i maleriers hvide pigmenter....

  9. Pigmented villonodular synovitis

    Energy Technology Data Exchange (ETDEWEB)

    Al-Nakshabandi, N.A.; Ryan, A.G.; Choudur, H.; Torreggiani, W.; Nicoloau, S.; Munk, P.L. E-mail: plmunk@interchange.ubc.ca; Al-Ismail, K

    2004-05-01

    Pigmented villonodular synovitis (PVNS) is a rare benign proliferative growth of the synovium of obscure aetiology with a wide spectrum of clinical presentations and imaging findings. The purpose of this review is to acquaint the reader with the spectrum of imaging features of PVNS using a variety of imaging techniques.

  10. Using of cyanobacteria pigments

    OpenAIRE

    Кардаш, О. В.; Національний авіаційний університет; Курейшевич, А. В.; Інститут гідробіології НАН України; Васильченко, О. А.; Національний авіаційний університет

    2012-01-01

    Photosynthetic apparatus of all organisms contains light absorbing pigments. Cyanobacteria pigments may be divided into three groups – chlorophylls, carotenoids and phycobiliproteins. Pigments may be used in the food and pharmaceutical industry. Cyanobacteria pigments features and usage possibilities are observed. Фотосинтезирующий аппарат всех организмов состоит из поглощающих свет пигментов. Пигменты цианобактерий можно разделить на три группы – хлорофиллы, каротиноиды и фикобилипротеины...

  11. Raman af hvide pigmenter

    DEFF Research Database (Denmark)

    Reeler, Nini Elisabeth Abildgaard; Nielsen, Ole Faurskov; Sauer, Stephan P. A.

    2013-01-01

    Et samspil mellem kunst og kemi. I et samarbejde mellem Statens Museum for Kunst og Kemisk Institut på KU er Ramanspek-troskopi brugt til at definere sammensætningen af blandinger af blyhvidt og calcit i maleriers hvide pigmenter....

  12. Sub-nm 3D observation of human hair melanin by high-voltage STEM.

    Science.gov (United States)

    Imai, Takehito; Higuchi, Kimitaka; Yamamoto, Yuta; Arai, Shigeo; Nakano, Takashi; Tanaka, Nobuo

    2016-04-01

    The ultrastructure of melanin granules in human hair was studied using 1,000 kV high-voltage scanning transmission electron microscopy to successfully reconstruct three-dimensional images of the whole melanin granule. It was revealed that the melanin granule was composed of a membrane-like outer structure that included many spherical vesicles, and an inner matrix containing a sheet-like structure in the elongated direction of the melanin granule and a sheet-like arrays structure in the cross direction. The outer structure of the melanin granule was maintained even after exposure to hair-bleaching agents to decompose the melanin granule, suggesting that the outer structure was a highly robust structure and composition compared with the inner matrix . © The Author 2015. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Phototrophic pigment production with microalgae

    NARCIS (Netherlands)

    Mulders, K.J.M.

    2014-01-01

    Abstract

    Microalgal pigments are regarded as natural alternatives for food colorants. To facilitate optimization of microalgae-based pigment production, this thesis aimed to obtain key insights in the pigment metabolism of phototrophic microalgae, with the main  focus

  14. Phototrophic pigment production with microalgae

    NARCIS (Netherlands)

    Mulders, K.J.M.

    2014-01-01

    Abstract

    Microalgal pigments are regarded as natural alternatives for food colorants. To facilitate optimization of microalgae-based pigment production, this thesis aimed to obtain key insights in the pigment metabolism of phototrophic microalgae, with the main  focus

  15. Production of natural edible melanin by Auricularia auricula and its physicochemical properties.

    Science.gov (United States)

    Sun, Shujing; Zhang, Xiaojuan; Chen, Wenxing; Zhang, Liaoyuan; Zhu, Hu

    2016-04-01

    Fermentation conditions of natural edible melanin by Auricularia auricula were optimized to obtain a high melanin yield and physicochemical properties of melanin were firstly investigated. The results indicated that yeast extract, tyrosine and lactose have significant effects on melanin production. Under the proposed optimized conditions, the melanin experimental yield (2.97 g/L) closely matched the value (3.04 g/L) predicted by the second-order model, which provided a statistically prediction of media in submerged fermentation of A. auricula. The yield achieved was 2.14-fold higher compared to the control. It was firstly revealed that tyrosine could stimulate melanin synthesis in A. auricula. The results showed that this melanin had better thermostability and light resistance, and its solubility was relatively high under alkaline conditions. Zn(2+) and Cu(2+) could result in melanin precipitation. The results should be useful for the efficient production of melanin and enable numerous applications in food, cosmetics, pharmacology, medicines and other fields.

  16. Production and cytotoxicity of extracellular insoluble and droplets of soluble melanin by Streptomyces lusitanus DMZ-3.

    Science.gov (United States)

    Madhusudhan, D N; Mazhari, Bi Bi Zainab; Dastager, Syed G; Agsar, Dayanand

    2014-01-01

    A Streptomyces lusitanus DMZ-3 strain with potential to synthesize both insoluble and soluble melanins was detected. Melanins are quite distinguished based on their solubility for varied biotechnological applications. The present investigation reveals the enhanced production of insoluble and soluble melanins in tyrosine medium by a single culture. Streptomyces lusitanus DMZ-3 was characterized by 16S rRNA gene analysis. An enhanced production of 5.29 g/L insoluble melanin was achieved in a submerged bioprocess following response surface methodology. Combined interactive effect of temperature (50°C), pH (8.5), tyrosine (2.0 g/L), and beef extract (0.5 g/L) were found to be critical variables for enhanced production in central composite design analysis. An optimized indigenous slant culture system was an innovative approach for the successful production (264 mg/L) of pure soluble melanin from the droplets formed on the surface of the culture. Both insoluble and soluble melanins were confirmed and characterized by Chemical, reactions, UV, FTIR, and TLC analysis. First time, cytotoxic study of melanin using brine shrimps was reported. Maximum cytotoxic activity of soluble melanin was Lc50-0.40 µg/mL and insoluble melanin was Lc50-0.80 µg/mL.

  17. Different culture media containing methyldopa for melanin production by Cryptococcus species

    Directory of Open Access Journals (Sweden)

    Ralciane de Paula Menezes

    2011-10-01

    Full Text Available INTRODUCTION: Melanin production by species of Cryptococcus is widely used to characterize C. neoformans complex in mycology laboratories. This study aims to test the efficacy of methyldopa from pharmaceutical tablet as a substrate for melanin production, to compare the production of melanin using different agar base added with methyldopa, and to compare the melanin produced in those media with that produced in Niger seed agar and sunflower seed agar by C. neoformans, C. laurentii, and C. albidus. Two isolates of each species, C. neoformans, C. laurentii, and C. albidus, and one of Candida albicans were used to experimentally detect conditions for melanin production. METHODS: The following media were tested: Mueller-Hinton agar (MHA, brain and heart infusion agar (BHIA, blood agar base (BAB, and minimal medium agar (MMA, all added with methyldopa, and the media Niger seed agar (NSA and sunflower seed agar (SSA. RESULTS: All isolates grew in most of the culture media after 24h. Strains planted on media BAB and BHIA showed growth only after 48h. All isolates produced melanin in MMA, MHA, SSA, and NSA media. CONCLUSIONS: Methyldopa in the form pharmaceutical tablet can be used as a substrate for melanin production by Cryptococcus species; minimal medium plus methyldopa was more efficient than the BAB, MHA, and BHIA in the melanin production; and NSA and SSA, followed by MMA added with methyldopa, were more efficient than other media studied for melanin production by all strains studied.

  18. Determination of pigments in vegetables.

    Science.gov (United States)

    Schoefs, Benoît

    2004-10-29

    Plant pigments are responsible for the shining color of plant tissues. They are also found in animal tissues and, eventually in transformed food products as additives. These pigments have an important impact on the commercial value of products, because the colors establish the first contact with the consumer. In addition plant pigments may have an influence on the health of the consumers. Pigments are labile: they can be easily altered, and even destroyed. Analytical processes have been developed to determine pigment composition. The aim of this paper is to provide a brief overview of these methods.

  19. Gene expression analysis of zebrafish melanocytes, iridophores, and retinal pigmented epithelium reveals indicators of biological function and developmental origin.

    Science.gov (United States)

    Higdon, Charles W; Mitra, Robi D; Johnson, Stephen L

    2013-01-01

    In order to facilitate understanding of pigment cell biology, we developed a method to concomitantly purify melanocytes, iridophores, and retinal pigmented epithelium from zebrafish, and analyzed their transcriptomes. Comparing expression data from these cell types and whole embryos allowed us to reveal gene expression co-enrichment in melanocytes and retinal pigmented epithelium, as well as in melanocytes and iridophores. We found 214 genes co-enriched in melanocytes and retinal pigmented epithelium, indicating the shared functions of melanin-producing cells. We found 62 genes significantly co-enriched in melanocytes and iridophores, illustrative of their shared developmental origins from the neural crest. This is also the first analysis of the iridophore transcriptome. Gene expression analysis for iridophores revealed extensive enrichment of specific enzymes to coordinate production of their guanine-based reflective pigment. We speculate the coordinated upregulation of specific enzymes from several metabolic pathways recycles the rate-limiting substrate for purine synthesis, phosphoribosyl pyrophosphate, thus constituting a guanine cycle. The purification procedure and expression analysis described here, along with the accompanying transcriptome-wide expression data, provide the first mRNA sequencing data for multiple purified zebrafish pigment cell types, and will be a useful resource for further studies of pigment cell biology.

  20. Gene expression analysis of zebrafish melanocytes, iridophores, and retinal pigmented epithelium reveals indicators of biological function and developmental origin.

    Directory of Open Access Journals (Sweden)

    Charles W Higdon

    Full Text Available In order to facilitate understanding of pigment cell biology, we developed a method to concomitantly purify melanocytes, iridophores, and retinal pigmented epithelium from zebrafish, and analyzed their transcriptomes. Comparing expression data from these cell types and whole embryos allowed us to reveal gene expression co-enrichment in melanocytes and retinal pigmented epithelium, as well as in melanocytes and iridophores. We found 214 genes co-enriched in melanocytes and retinal pigmented epithelium, indicating the shared functions of melanin-producing cells. We found 62 genes significantly co-enriched in melanocytes and iridophores, illustrative of their shared developmental origins from the neural crest. This is also the first analysis of the iridophore transcriptome. Gene expression analysis for iridophores revealed extensive enrichment of specific enzymes to coordinate production of their guanine-based reflective pigment. We speculate the coordinated upregulation of specific enzymes from several metabolic pathways recycles the rate-limiting substrate for purine synthesis, phosphoribosyl pyrophosphate, thus constituting a guanine cycle. The purification procedure and expression analysis described here, along with the accompanying transcriptome-wide expression data, provide the first mRNA sequencing data for multiple purified zebrafish pigment cell types, and will be a useful resource for further studies of pigment cell biology.

  1. EPR examination of Zn{sup 2+} and Cu{sup 2+} binding by pigmented soil fungi Cladosporium cladosporioides

    Energy Technology Data Exchange (ETDEWEB)

    Buszman, Ewa [Department of Pharmaceutical Chemistry, School of Pharmacy, Medical University of Silesia, Jagiellonska 4, 41-200 Sosnowiec (Poland)]. E-mail: ebuszman@slam.katowice.pl; Pilawa, Barbara [Department of Medical Physics, School of Pharmacy, Medical University of Silesia, Narcyzow 1, 41-200 Sosnowiec (Poland); Zdybel, Magdalena [Department of Medical Physics, School of Pharmacy, Medical University of Silesia, Narcyzow 1, 41-200 Sosnowiec (Poland); Wilczynski, Slawomir [Department of Medical Physics, School of Pharmacy, Medical University of Silesia, Narcyzow 1, 41-200 Sosnowiec (Poland); Gondzik, Anna [Department of Medical Physics, School of Pharmacy, Medical University of Silesia, Narcyzow 1, 41-200 Sosnowiec (Poland); Witoszynska, Teresa [Department of Pharmaceutical Chemistry, School of Pharmacy, Medical University of Silesia, Jagiellonska 4, 41-200 Sosnowiec (Poland); Wilczok, Tadeusz [Department of Molecular Biology and Genetics, School of Pharmacy, Medical University of Silesia, Narcyzow 1, 41-200 Sosnowiec (Poland)

    2006-06-15

    The purpose of this study was to examine the usefulness of electron paramagnetic resonance spectroscopy (EPR) to estimate zinc and copper ions biosorption from the environment by pigmented soil fungi Cladosporium cladosporioides. The existence of a low amount of pheomelanin, besides eumelanin, in C. cladosporioides samples was proved by the analysis of shape of their EPR spectra. Concentration of o-semiquinone free radicals in crude mycelium was 2.4 x 10{sup 17} spin/g. Changes in free radicals system of C. cladosporioides cultured in the presence of Zn{sup 2+} and Cu{sup 2+} were analysed. Both magnetic and chemical interactions of zinc and copper ions with free radicals in C. cladosporioides melanin were found. Magnetically interacting diamagnetic Zn{sup 2+} ions increased the concentration of o-semiquinone free radicals in melanin existing in C. cladosporioides mycelium, whereas paramagnetic Cu{sup 2+} ions decreased this concentration. Chemical interactions of Zn{sup 2+} and Cu{sup 2+} ions decreased the free radical concentrations in C. cladosporioides melanin. Homogeneously distributed free radicals in C. cladosporioides melanin rise its activity in biosorption processes.

  2. Unusual nail pigmentation following cyclophosphamide-containing chemotherapy regimen

    Directory of Open Access Journals (Sweden)

    Kumar Santosh

    2010-01-01

    Full Text Available Cyclophosphamide therapy may rarely cause pigmentation of the nails which is of different patterns. We report a patient who developed pigmentation of nails after six cycles of cyclophosphamide, methotrexate, and 5-flourouracil chemotherapy, each repeated after 28 days for breast cancer. The patient developed nail pigmentation that started proximally and spread distally and involved all the nails of both hands and feet except the second and third toenails of right foot. Using Naranjo ADR Probability Scale, the case revealed a "probable" association with cyclophosphamide.

  3. Pigmentos maculares Macular pigments

    Directory of Open Access Journals (Sweden)

    Renata Canovas

    2009-12-01

    Full Text Available A luteína e a zeaxantina são pigmentos amarelos que se localizam na mácula. Devido à sua localização, diminuem e filtram a quantidade de luz principalmente azul que chega aos fotorreceptores, atuam como antioxidantes e podem melhorar a qualidade visual. Esta é uma revisão do seu mecanismo de incorporação, ação, possíveis aplicações e conhecimento científico a respeito.Lutein and Zeaxanthin are yellow pigments located at the macula. Because of your location macular pigments decrease and filter the amount of blue light that reach photoreceptors, protect the outer retina from oxidative stress and may improve the vision quality. This is a review regarding incorporation mechanism, function and knowledge update.

  4. Dermoscopy Clues in Pigmented Bowen's Disease

    Directory of Open Access Journals (Sweden)

    Daniela Gutiérrez-Mendoza

    2010-01-01

    Full Text Available Pigmented tumors have similar clinical features that overlap and hamper diagnosis. Dermoscopy increases the diagnostic accuracy of doubtful melanocytic lesions and has been used as a noninvasive tool in the detection of pigmented lesions (PLs like melanoma, basal cell carcinoma, and pigmented Bowen's disease (pBD. Our objective was to show the dermoscopic features of 2 cases of pBD and compare with the findings reported in the literature. Two dermoscopic images of biopsy proven pBD were retrospectively analyzed for dermoscopic patterns. Both cases showed brown regular globules, structureless brown and blue pigmentation, glomerular vessels, hypopigmented regression-like areas, and keratosis. These findings were similar to the cases reported previously. The dermoscopic diagnosis of pBD is based on the absence of criteria for a melanocytic lesion in the presence of glomerular vessels, regular brown globules and keratosis. Although pBD is rare, it should be included in the differential diagnosis of PLs, especially melanoma.

  5. Pigment dispersion syndrome

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    C.S. Sandhya

    2013-10-01

    Full Text Available We report of the rare occurrence of pigment dispersion syndrome (PDS with posterior subcapsular cataract in both eyes in a young male patient. The patient presented with complaints of progressive decrease in vision of one year duration. The patient also had high myopia with mild iridodonesis, phacodonesis and anterior insertion of zonules. Classical signs of PDS like Krukenberg's spindle on the posterior corneal surface were evident on slit lamp examination; transillumination defects in the iris could not be elicited by retroillumination as the iris was heavily pigmented. Gonioscopy revealed heavy and uniform pigmentation of trabecular meshwork. Evidence of a characteristic iris configuration on optical coherence tomography (OCT, namely, posterior bowing of iris in the mid periphery suggested the diagnosis of PDS. This case highlights the importance of OCT in identifying the iris configuration characteristically seen in PDS even in the absence of transillumination defects in the iris and reiterates the need to look for subtle signs like phacodonesis which are important when surgical intervention is planned.

  6. Regulatory mutations in TBX3 disrupt asymmetric hair pigmentation that underlies Dun camouflage color in horses

    DEFF Research Database (Denmark)

    Imsland, Freyja; McGowan, Kelly; Rubin, Carl-Johan

    2016-01-01

    Dun is a wild-type coat color in horses characterized by pigment dilution with a striking pattern of dark areas termed primitive markings. Here we show that pigment dilution in Dun horses is due to radially asymmetric deposition of pigment in the growing hair caused by localized expression of the...

  7. The beet Y locus encodes an anthocyanin-MYB-like protein that activates the betalain red pigment pathway

    Science.gov (United States)

    Almost all flowering plants produce red/violet, phenylalanine-based, anthocyanin pigments. A single order, the Caryophyllales, contains families that replace anthocyanins with tyrosine-based red and yellow betalain pigments. Close biological correlation of pigmentation patterns suggested that betala...

  8. Insolubilization of Chestnut Shell Pigment for Cu(II Adsorption from Water

    Directory of Open Access Journals (Sweden)

    Zeng-Yu Yao

    2016-03-01

    Full Text Available Chestnut shell pigment (CSP is melanin from an agricultural waste. It has potential as an adsorbent for wastewater treatment but cannot be used in its original state because of its solubility in water. We developed a new method to convert CSP to insolubilized chestnut shell pigment (ICSP by heating, and the Cu(II adsorption performance of ICSP was evaluated. The conversion was characterized, and the thermal treatment caused dehydration and loss of carboxyl groups and aliphatic structures in CSP. The kinetic adsorption behavior obeyed the pseudo-second-order rate law, and the equilibrium adsorption data were well described with both the Langmuir and the Freundlich isotherms. ICSP can be used as a renewable, readily-available, easily-producible, environmentally-friendly, inexpensive and effective adsorbent to remove heavy-metal from aquatic environments.

  9. Insolubilization of Chestnut Shell Pigment for Cu(II) Adsorption from Water.

    Science.gov (United States)

    Yao, Zeng-Yu; Qi, Jian-Hua; Hu, Yong; Wang, Ying

    2016-03-28

    Chestnut shell pigment (CSP) is melanin from an agricultural waste. It has potential as an adsorbent for wastewater treatment but cannot be used in its original state because of its solubility in water. We developed a new method to convert CSP to insolubilized chestnut shell pigment (ICSP) by heating, and the Cu(II) adsorption performance of ICSP was evaluated. The conversion was characterized, and the thermal treatment caused dehydration and loss of carboxyl groups and aliphatic structures in CSP. The kinetic adsorption behavior obeyed the pseudo-second-order rate law, and the equilibrium adsorption data were well described with both the Langmuir and the Freundlich isotherms. ICSP can be used as a renewable, readily-available, easily-producible, environmentally-friendly, inexpensive and effective adsorbent to remove heavy-metal from aquatic environments.

  10. Was skin cancer a selective force for black pigmentation in early hominin evolution?

    Science.gov (United States)

    Greaves, Mel

    2014-01-01

    Melanin provides a crucial filter for solar UV radiation and its genetically determined variation influences both skin pigmentation and risk of cancer. Genetic evidence suggests that the acquisition of a highly stable melanocortin 1 receptor allele promoting black pigmentation arose around the time of savannah colonization by hominins at some 1–2 Ma. The adaptive significance of dark skin is generally believed to be protection from UV damage but the pathologies that might have had a deleterious impact on survival and/or reproductive fitness, though much debated, are uncertain. Here, I suggest that data on age-associated cancer incidence and lethality in albinos living at low latitudes in both Africa and Central America support the contention that skin cancer could have provided a potent selective force for the emergence of black skin in early hominins. PMID:24573849

  11. Effective melanin depigmentation of human and murine ocular tissues: an improved method for paraffin and frozen sections.

    Directory of Open Access Journals (Sweden)

    Caroline Manicam

    Full Text Available PURPOSE: The removal of excessive melanin pigments that obscure ocular tissue morphology is important to address scientific questions and for differential diagnosis of ocular tumours based on histology. Thus, the goal of the present study was to establish an effective and fast melanin bleaching method for paraffin and frozen mouse and human ocular tissues. METHODS: Paraffin-embedded and frozen ocular specimens from mice and human donors were subjected to bleaching employing two methods. The first employed potassium permanganate (KMnO4 with oxalic acid, and the second 10% hydrogen peroxide (H2O2. To determine optimal bleaching conditions, depigmentation was carried out at various incubation times. The effect of diluents used for 10% H2O2 was assessed using phosphate-buffered saline (PBS, and deionized water. Three different slide types and two fixatives, which were ice-cold acetone with 80% methanol, and 4% paraformaldehyde (PFA were used to determine the optimal conditions for better tissue adherence during bleaching. All tissues were stained in hematoxylin and eosin for histological evaluation. RESULTS: Optimal bleaching was achieved using warm 10% H2O2 diluted in PBS at 65°C for 120 minutes. Chromium-gelatin-coated slides prevented tissue detachment. Adherence of cryosections was also improved with post-fixation using 4% PFA and overnight air-drying at RT after cryosectioning. Tissue morphology was preserved under these conditions. Conversely, tissues bleached in KMnO4/oxalic acid demonstrated poor depigmentation with extensive tissue damage. CONCLUSIONS: Warm dilute H2O2 at 65°C for 120 minutes rapidly and effectively bleached both cryo- and paraffin sections of murine and human ocular tissues.

  12. A multidisciplinary study of the extracutaneous pigment system of European sea bass (Dicentrarchus labrax L.). A possible relationship between kidney disease and dopa oxidase activity level.

    Science.gov (United States)

    Arciuli, Marcella; Brunetti, Adalberto; Fiocco, Daniela; Zacchino, Valentina; Centoducati, Gerardo; Aloi, Antonio; Tommasi, Raffaele; Santeramo, Arcangela; De Nitto, Emanuele; Gallone, Anna

    2015-01-01

    Infectious diseases and breeding conditions can influence fish health status. Furthermore it is well known that human and animal health are strongly correlated. In lower vertebrates melano-macrophage centres, clusters of pigment-containing cells forming the extracutaneous pigment system, are widespread in the stroma of the haemopoietic tissue, mainly in kidney and spleen. In fishes, melano-macrophage centres play an important role in the immune response against antigenic stimulants and pathogens. Hence, they are employed as biomarker of fish health status. We have investigated this cell system in the European sea bass (Dicentrarchus labrax L.) following the enzyme activities involved in melanin biosynthesis. We have found a possible relationship between kidney disease of farmed fishes and dopa oxidase activity level, suggesting it as an indicator of kidney disease. Moreover variations of dopa oxidase activity in extracutaneous pigment system have been observed with respect to environmental temperature. At last, for the first time, using femtosecond transient absorption spectroscopy (Femto-TA), we pointed out that pigment-containing cells of fish kidney tissue present melanin pigments.

  13. Modelling and verification of melanin concentration on human skin type

    CSIR Research Space (South Africa)

    Karsten, AE

    2012-03-01

    Full Text Available -brown colour) and pheomelanin (yellow-reddish 11 colour) (3,4). Melanin is synthesized within melanosomes inside melanocytes located in the 12 basal layer of the epidermis and the mature melanosomes get transferred via dendrites to the 13 keratinocytes... in die epidermis where they are responsible for skin photoprotection (3). 14 It is well documented that the absorption and scattering of light through skin tissue 15 depends on the skin?s optical properties (see for example studies by Tuchin (5...

  14. Study on the scavenging DPPH free radical activity of melanin in crude product of Chinese sweet gum leaves%枫香树叶黑色素粗产品清除DPPH自由基活性研究

    Institute of Scientific and Technical Information of China (English)

    谢宇奇; 莫春凤; 奚文权

    2016-01-01

    The ability of melanin in Chinese sweet gum leaves for scavenging DPPH free radical activity was discussed in order to utilize the resource of Chinese sweet gum leaves. The melanin was extracted by immersion extraction;the crude product of melanin in the leaves was purified with AB - 8 macroporous resin. The antioxidant ability of the melanin in the leaves,ascorbic acid (Vc),pyrogallic acid,tert -butyl hydroquinone (TBHQ)and 2,6 Di tert - butyl and other substances was evaluated. The results showed that IC50 value of the melanin crude product prepared by the method was 3. 41,the order of scav-enging DPPH free radical ability of unit mass of antioxidant was pyrogallic acid > TBHQ > ascorbic acid >Chinese sweet gum leaves melanin crude product > BHT. Chinese sweet gum leaves melanin has a certain ability of scavenging DPPH free radical activity,which,as a natural pigment,has broad application pros-pect in the field of food,medicine,cosmetics and so on.%为开发利用枫香树叶资源,探讨枫香树叶黑色素清除DPPH 自由基活性的能力,浸渍提取黑色素,经AB -8大孔树脂初步纯化后得到枫香树叶黑色素粗产品。通过DPPH清除率曲线和计算IC50,评价枫香树叶黑色素、抗坏血酸、焦性没食子酸、叔丁基对苯二酚(TBHQ)、2,6-二叔丁基对甲酚等物质的抗氧化能力。结果表明:通过该方法制取的枫香树叶黑色素粗产品的IC 50值为3.41,单位质量抗氧化剂清除DPPH自由基能力次序为焦性没食子酸> TBHQ >抗坏血酸>枫香树叶黑色素粗产品> BHT。枫香树叶黑色素具有一定的清除DPPH自由基活性,作为天然色素,其在食品、药品、化妆品等领域的应用前景广阔。

  15. Decomposition dynamic of higher plant pigments by HPLC analysis

    Institute of Scientific and Technical Information of China (English)

    LUO Yi; ZHANG Ting-zhou; ZHOU Qi-xing; MAO Da-qing; WAN Dong-mei

    2004-01-01

    The fate of the litter of dominant vegetation(willows and reeds) is one of the aspects studied in the frame of the project "Onderzoek Milieu Effecten Sigmaplan". One of the questions to be considered is how long the litter stays within the estuary. In this paper, the time the leaf litter(Salix triandra and Phragmites australis) stayed in the Schelde estuary was studied by using plant pigment as biomarkers with HPLC application. After analyzing the original data from the incubation experiment described by Dubuison and Geers(1999), the decomposition dynamics patterns of pigments were analyzed and described, and these decomposition dynamics patterns were used as calibration patterns. By using Spearman Rank Order Correlation, the calibration patterns of the pigments which were significant(p<0.05) were grouped. In this way, several groups of the calibration patterns of pigment decomposition were achieved. The presence or absence of these groups of pigments (whether they can be detected or not from HPLC) was shown to be useful in determining the time the litter has stayed in the water. Combining data of DW and POC, more precise timing can be obtained.

  16. CONSTITUTIVE MELANIN IN THE CELL WALL OF THE ETIOLOGIC AGENT OF LOBO'S DISEASE

    Directory of Open Access Journals (Sweden)

    TABORDA Valeria B.A.

    1999-01-01

    Full Text Available Lobo's disease is a chronic granulomatous disease caused by the obligate pathogenic fungus, whose cell walls contain constitutive melanin. In contrast, melanin does not occur in the cell walls of Paracoccidioides brasiliensis when stained by the Fontana-Masson stain.

  17. Melanins Protect Sporothrix brasiliensis and Sporothrix schenckii from the Antifungal Effects of Terbinafine.

    Directory of Open Access Journals (Sweden)

    Rodrigo Almeida-Paes

    Full Text Available Terbinafine is a recommended therapeutic alternative for patients with sporotrichosis who cannot use itraconazole due to drug interactions or side effects. Melanins are involved in resistance to antifungal drugs and Sporothrix species produce three different types of melanin. Therefore, in this study we evaluated whether Sporothrix melanins impact the efficacy of antifungal drugs. Minimal inhibitory concentrations (MIC and minimal fungicidal concentrations (MFC of two Sporothrix brasiliensis and four Sporothrix schenckii strains grown in the presence of the melanin precursors L-DOPA and L-tyrosine were similar to the MIC determined by the CLSI standard protocol for S. schenckii susceptibility to amphotericin B, ketoconazole, itraconazole or terbinafine. When MICs were determined in the presence of inhibitors to three pathways of melanin synthesis, we observed, in four strains, an increase in terbinafine susceptibility in the presence of tricyclazole, a DHN-melanin inhibitor. In addition, one S. schenckii strain grown in the presence of L-DOPA had a higher MFC value when compared to the control. Growth curves in presence of 2×MIC concentrations of terbinafine showed that pyomelanin and, to a lesser extent, eumelanin were able to protect the fungi against the fungicidal effect of this antifungal drug. Our results suggest that melanin protects the major pathogenic species of the Sporothrix complex from the effects of terbinafine and that the development of new antifungal drugs targeting melanin synthesis may improve sporotrichosis therapies.

  18. Melanins Protect Sporothrix brasiliensis and Sporothrix schenckii from the Antifungal Effects of Terbinafine

    Science.gov (United States)

    Almeida-Paes, Rodrigo; Figueiredo-Carvalho, Maria Helena Galdino; Brito-Santos, Fábio; Almeida-Silva, Fernando; Oliveira, Manoel Marques Evangelista; Zancopé-Oliveira, Rosely Maria

    2016-01-01

    Terbinafine is a recommended therapeutic alternative for patients with sporotrichosis who cannot use itraconazole due to drug interactions or side effects. Melanins are involved in resistance to antifungal drugs and Sporothrix species produce three different types of melanin. Therefore, in this study we evaluated whether Sporothrix melanins impact the efficacy of antifungal drugs. Minimal inhibitory concentrations (MIC) and minimal fungicidal concentrations (MFC) of two Sporothrix brasiliensis and four Sporothrix schenckii strains grown in the presence of the melanin precursors L-DOPA and L-tyrosine were similar to the MIC determined by the CLSI standard protocol for S. schenckii susceptibility to amphotericin B, ketoconazole, itraconazole or terbinafine. When MICs were determined in the presence of inhibitors to three pathways of melanin synthesis, we observed, in four strains, an increase in terbinafine susceptibility in the presence of tricyclazole, a DHN-melanin inhibitor. In addition, one S. schenckii strain grown in the presence of L-DOPA had a higher MFC value when compared to the control. Growth curves in presence of 2×MIC concentrations of terbinafine showed that pyomelanin and, to a lesser extent, eumelanin were able to protect the fungi against the fungicidal effect of this antifungal drug. Our results suggest that melanin protects the major pathogenic species of the Sporothrix complex from the effects of terbinafine and that the development of new antifungal drugs targeting melanin synthesis may improve sporotrichosis therapies. PMID:27031728

  19. Melanins Protect Sporothrix brasiliensis and Sporothrix schenckii from the Antifungal Effects of Terbinafine.

    Science.gov (United States)

    Almeida-Paes, Rodrigo; Figueiredo-Carvalho, Maria Helena Galdino; Brito-Santos, Fábio; Almeida-Silva, Fernando; Oliveira, Manoel Marques Evangelista; Zancopé-Oliveira, Rosely Maria

    2016-01-01

    Terbinafine is a recommended therapeutic alternative for patients with sporotrichosis who cannot use itraconazole due to drug interactions or side effects. Melanins are involved in resistance to antifungal drugs and Sporothrix species produce three different types of melanin. Therefore, in this study we evaluated whether Sporothrix melanins impact the efficacy of antifungal drugs. Minimal inhibitory concentrations (MIC) and minimal fungicidal concentrations (MFC) of two Sporothrix brasiliensis and four Sporothrix schenckii strains grown in the presence of the melanin precursors L-DOPA and L-tyrosine were similar to the MIC determined by the CLSI standard protocol for S. schenckii susceptibility to amphotericin B, ketoconazole, itraconazole or terbinafine. When MICs were determined in the presence of inhibitors to three pathways of melanin synthesis, we observed, in four strains, an increase in terbinafine susceptibility in the presence of tricyclazole, a DHN-melanin inhibitor. In addition, one S. schenckii strain grown in the presence of L-DOPA had a higher MFC value when compared to the control. Growth curves in presence of 2×MIC concentrations of terbinafine showed that pyomelanin and, to a lesser extent, eumelanin were able to protect the fungi against the fungicidal effect of this antifungal drug. Our results suggest that melanin protects the major pathogenic species of the Sporothrix complex from the effects of terbinafine and that the development of new antifungal drugs targeting melanin synthesis may improve sporotrichosis therapies.

  20. Color reduction of melanin by lysosomal and peroxisomal enzymes isolated from mammalian cells.

    Science.gov (United States)

    Park, Dong Jun; Sekhon, Simranjeet Singh; Yoon, Jihee; Kim, Yang-Hoon; Min, Jiho

    2016-02-01

    Lysosomes and peroxisomes are organelles with many functions in all eukaryotic cells. Lysosomes contain hydrolytic enzymes (lysozyme) that degrade molecules, whereas peroxisomes contain enzymes such as catalase that convert hydrogen peroxide (H2O2) to water and oxygen and neutralize toxicity. In contrast, melanin is known as a helpful element to protect the skin against harmful ultraviolet rays. However, a high quantity of melanin leads to hyperpigmentation or skin cancer in human. New materials have already been discovered to inhibit tyrosinase in melanogenesis; however, melanin reduction does not suggest their preparation. In this study, we report that the color intensity because of melanin decreased by the cellular activation of lysosomes and peroxisomes. An increase in the superficial intensity of lysosome and peroxisome activities of HeLa cells was observed. In addition, a decrease in the amount of melanin has also been observed in mammalian cells without using any other chemical, showing that the process can work in vivo for treating melanin. Therefore, the results of this study indicate that the amount of melanin decreases by the lysosome and peroxisome activity after entering the cells, and functional organelles are effective in color reduction. This mechanism can be used in vivo for treating melanin.

  1. Loss of Homogentisate 1,2-Dioxygenase Activity in Bacillus anthracis Results in Accumulation of Protective Pigment.

    Science.gov (United States)

    Han, Hesong; Iakovenko, Liudmyla; Wilson, Adam C

    2015-01-01

    Melanin production is important to the pathogenicity and survival of some bacterial pathogens. In Bacillus anthracis, loss of hmgA, encoding homogentisate 1,2-dioxygenase, results in accumulation of a melanin-like pigment called pyomelanin. Pyomelanin is produced in the mutant as a byproduct of disrupted catabolism of L-tyrosine and L-phenylalanine. Accumulation of pyomelanin protects B. anthracis cells from UV damage but not from oxidative damage. Neither loss of hmgA nor accumulation of pyomelanin alter virulence gene expression, sporulation or germination. This is the first investigation of homogentisate 1,2-dioxygenase activity in the Gram-positive bacteria, and these results provide insight into a conserved aspect of bacterial physiology.

  2. Loss of Homogentisate 1,2-Dioxygenase Activity in Bacillus anthracis Results in Accumulation of Protective Pigment.

    Directory of Open Access Journals (Sweden)

    Hesong Han

    Full Text Available Melanin production is important to the pathogenicity and survival of some bacterial pathogens. In Bacillus anthracis, loss of hmgA, encoding homogentisate 1,2-dioxygenase, results in accumulation of a melanin-like pigment called pyomelanin. Pyomelanin is produced in the mutant as a byproduct of disrupted catabolism of L-tyrosine and L-phenylalanine. Accumulation of pyomelanin protects B. anthracis cells from UV damage but not from oxidative damage. Neither loss of hmgA nor accumulation of pyomelanin alter virulence gene expression, sporulation or germination. This is the first investigation of homogentisate 1,2-dioxygenase activity in the Gram-positive bacteria, and these results provide insight into a conserved aspect of bacterial physiology.

  3. Nonphotosynthetic Pigments as Potential Biosignatures

    CERN Document Server

    Schwieterman, Edward W; Meadows, Victoria S

    2015-01-01

    Previous work on possible surface reflectance biosignatures for Earth-like planets has typically focused on analogues to spectral features produced by photosynthetic organisms on Earth, such as the vegetation red edge. Although oxygenic photosynthesis, facilitated by pigments evolved to capture photons, is the dominant metabolism on our planet, pigmentation has evolved for multiple purposes to adapt organisms to their environment. We present an interdisciplinary study of the diversity and detectability of nonphotosynthetic pigments as biosignatures, which includes a description of environments that host nonphotosynthetic biologically pigmented surfaces, and a lab-based experimental analysis of the spectral and broadband color diversity of pigmented organisms on Earth. We test the utility of broadband color to distinguish between Earth-like planets with significant coverage of nonphotosynthetic pigments and those with photosynthetic or nonbiological surfaces, using both 1-D and 3-D spectral models. We demonstr...

  4. Cuba: exploring the history of admixture and the genetic basis of pigmentation using autosomal and uniparental markers.

    Science.gov (United States)

    Marcheco-Teruel, Beatriz; Parra, Esteban J; Fuentes-Smith, Evelyn; Salas, Antonio; Buttenschøn, Henriette N; Demontis, Ditte; Torres-Español, María; Marín-Padrón, Lilia C; Gómez-Cabezas, Enrique J; Alvarez-Iglesias, Vanesa; Mosquera-Miguel, Ana; Martínez-Fuentes, Antonio; Carracedo, Angel; Børglum, Anders D; Mors, Ole

    2014-07-01

    We carried out an admixture analysis of a sample comprising 1,019 individuals from all the provinces of Cuba. We used a panel of 128 autosomal Ancestry Informative Markers (AIMs) to estimate the admixture proportions. We also characterized a number of haplogroup diagnostic markers in the mtDNA and Y-chromosome in order to evaluate admixture using uniparental markers. Finally, we analyzed the association of 16 single nucleotide polymorphisms (SNPs) with quantitative estimates of skin pigmentation. In the total sample, the average European, African and Native American contributions as estimated from autosomal AIMs were 72%, 20% and 8%, respectively. The Eastern provinces of Cuba showed relatively higher African and Native American contributions than the Western provinces. In particular, the highest proportion of African ancestry was observed in the provinces of Guantánamo (40%) and Santiago de Cuba (39%), and the highest proportion of Native American ancestry in Granma (15%), Holguín (12%) and Las Tunas (12%). We found evidence of substantial population stratification in the current Cuban population, emphasizing the need to control for the effects of population stratification in association studies including individuals from Cuba. The results of the analyses of uniparental markers were concordant with those observed in the autosomes. These geographic patterns in admixture proportions are fully consistent with historical and archaeological information. Additionally, we identified a sex-biased pattern in the process of gene flow, with a substantially higher European contribution from the paternal side, and higher Native American and African contributions from the maternal side. This sex-biased contribution was particularly evident for Native American ancestry. Finally, we observed that SNPs located in the genes SLC24A5 and SLC45A2 are strongly associated with melanin levels in the sample.

  5. Cuba: exploring the history of admixture and the genetic basis of pigmentation using autosomal and uniparental markers.

    Directory of Open Access Journals (Sweden)

    Beatriz Marcheco-Teruel

    2014-07-01

    Full Text Available We carried out an admixture analysis of a sample comprising 1,019 individuals from all the provinces of Cuba. We used a panel of 128 autosomal Ancestry Informative Markers (AIMs to estimate the admixture proportions. We also characterized a number of haplogroup diagnostic markers in the mtDNA and Y-chromosome in order to evaluate admixture using uniparental markers. Finally, we analyzed the association of 16 single nucleotide polymorphisms (SNPs with quantitative estimates of skin pigmentation. In the total sample, the average European, African and Native American contributions as estimated from autosomal AIMs were 72%, 20% and 8%, respectively. The Eastern provinces of Cuba showed relatively higher African and Native American contributions than the Western provinces. In particular, the highest proportion of African ancestry was observed in the provinces of Guantánamo (40% and Santiago de Cuba (39%, and the highest proportion of Native American ancestry in Granma (15%, Holguín (12% and Las Tunas (12%. We found evidence of substantial population stratification in the current Cuban population, emphasizing the need to control for the effects of population stratification in association studies including individuals from Cuba. The results of the analyses of uniparental markers were concordant with those observed in the autosomes. These geographic patterns in admixture proportions are fully consistent with historical and archaeological information. Additionally, we identified a sex-biased pattern in the process of gene flow, with a substantially higher European contribution from the paternal side, and higher Native American and African contributions from the maternal side. This sex-biased contribution was particularly evident for Native American ancestry. Finally, we observed that SNPs located in the genes SLC24A5 and SLC45A2 are strongly associated with melanin levels in the sample.

  6. EFFECT OF CADMIUM(II) ON FREE RADICALS IN DOPA-MELANIN TESTED BY EPR SPECTROSCOPY.

    Science.gov (United States)

    Zdybel, Magdalena; Pilawa, Barbara; Chodurek, Ewa

    2015-01-01

    Electron paramagnetic resonance (EPR) spectroscopy may be applied to examine interactions of melanin with metal ions and drugs. In this work EPR method was used to examination of changes in free radical system of DOPA-melanin--the model eumelanin after complexing with diamagnetic cadmium(II) ions. Cadmium(II) may affect free radicals in melanin and drugs binding by this polymer, so the knowledge of modification of properties and free radical concentration in melanin is important to pharmacy. The effect of cadmium(II) in different concentrations on free radicals in DOPA-melanin was determined. EPR spectra of DOPA-melanin, and DOPA-melanin complexes with cadmium(II) were measured by an X-band (9.3 GHz) EPR spectrometer produced by Radiopan (Poznań, Poland) and the Rapid Scan Unit from Jagmar (Krak6w, Poland). The DOPA (3,4-dihydroxyphenylalanine) to metal ions molar ratios in the reaction mixtures were 2:1, 1:1, and 1: 2. High concentrations of o-semiquinone (g ~2.0040) free radicals (~10(21)-10(22) spin/g) characterize DOPA-melanin and its complexes with cadmium(II). Formation of melanin complexes with cadmium(II) increase free radical concentration in DOPA-melanin. The highest free radical concentration was obtained for DOPA-melanin-cadmium(II) (1:1) complexes. Broad EPR lines with linewidths: 0.37-0.73 mT, were measured. Linewidths increase after binding of cadmium(II) to melanin. Changes of integral intensities and linewidths with increasing microwave power indicate the homogeneous broadening of EPR lines, independently on the metal ion concentration. Slow spin-lattice relaxation processes existed in all the tested samples, their EPR lines saturated at low microwave powers. Cadmium(II) causes fastening of spin-lattice relaxation processes in DOPA-melanin. The EPR results bring to light the effect of cadmium(II) on free radicals in melanin, and probably as the consequence on drug binding to eumelanin.

  7. [Recurrent pigmented villonodular synovitis (PVNS)].

    Science.gov (United States)

    Neuss, M; Hermanns, B; Wirtz, D C

    2001-01-01

    The pigmented vilionodular synovitis (PVNS) is a tumour like disease of unknown origin that often shows recurrence. The pathogenesis is still unknown and therefore the question of the right therapy is not resolved. With a case report of a patient with recurrence after two arthroscopic synovectomies, PVNS is discussed against the background of the clinical, histological, and radiological features. We performed an open synovectomy and cystic lesions in both condyles of the femur and proximal tibia were filled with homologous and autologous cancellous bone. Three months later the patient had no pain and the bone density in the former cystic lesions was appropriate. The pathogenesis is still unknown. Diagnosis often is obtained much too late due to missing specific symptoms. PVNS occurs in local forms as well as in a diffuse growth pattern. Recurrence rates of up to 78% are very high. Besides arthroscopic and open synovectomy, the treatment with radiosynoviorthesis must be considered. Depending on the growth pattern, the tumour masses, and the affected joint, the therapy has to be chosen very carefully and sometimes different forms have to be combined if a recurrence--free result is to be achieved.

  8. Photodisruption increases the free-radical reactivity of melanosomes isolated from retinal pigment epithelium

    Science.gov (United States)

    Glickman, Randolph D.; Jacques, Steven L.; Schwartz, Jon A.; Rodriguez, Tom; Lam, Kwok-Wai; Buhr, Gwen

    1996-05-01

    Melanin in vivo is usually packaged in melanosomes with protein coats that restrict direct interaction of the melanin with the surrounding medium. We found that disruption of the melanosomes by exposure to a pulsed laser increased the ability of the melanin radicals to oxidize NADPH in a photochemical reaction. Retinal pigment epithelial (RPE) melanosomes were prepared from fresh bovine eyes in 0.25 M sucrose. A reaction mixture of 7 mM NADPH, approximately 7500 RPE melanosomes, and 80 mM Tris buffer, pH 7.2, was prepared in a volume of 60 (mu) l. Of the two 25-(mu) l aliquots taken from this mixture, one was pre-exposed to the 2nd-harmonic output of a Q-switched Nd:YAG laser (532 nm, 1800 10-nsec pulses at 10 Hz), and then was exposed to an Argon ion continuous wave (CW) laser (488.1 and 514.5 nm) for five minutes. The other aliquot was exposed only to the Argon laser. The CW exposure excited the melanin radicals to a reactive state that oxidized NADPH, as assayed by the loss of absorbance at 340 nm. Native melanosomes oxidized less NADPH during Ar+ laser pumping than did melanosomes pre-exposed to the YAG laser. The YAG laser's stimulatory effect on melanosomes reactivity increased as the total energy it delivered rose above 3.5 J (0.14 J/cm2/pulse X 1800 pulses), up to a maximum NADPH oxidation at about 20 J (0.2 J/cm2/pulse X 1800 pulses, beam broadened at higher pulse energy). Electron microscopic analysis of the melanosomes confirmed the progressive physical disruption of melanosomes as the YAG pulse energy increased.

  9. Role of Melanin in Melanocyte Dysregulation of Reactive Oxygen Species

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    Noah C. Jenkins

    2013-01-01

    Full Text Available We have recently reported a potential alternative tumor suppressor function for p16 relating to its capacity to regulate oxidative stress and observed that oxidative dysregulation in p16-depleted cells was most profound in melanocytes, compared to keratinocytes or fibroblasts. Moreover, in the absence of p16 depletion or exogenous oxidative insult, melanocytes exhibited significantly higher basal levels of reactive oxygen species (ROS than these other epidermal cell types. Given the role of oxidative stress in melanoma development, we speculated that this increased susceptibility of melanocytes to oxidative stress (and greater reliance on p16 for suppression of ROS may explain why genetic compromise of p16 is more commonly associated with predisposition to melanoma rather than other cancers. Here we show that the presence of melanin accounts for this differential oxidative stress in normal and p16-depleted melanocytes. Thus the presence of melanin in the skin appears to be a double-edged sword: it protects melanocytes as well as neighboring keratinocytes in the skin through its capacity to absorb UV radiation, but its synthesis in melanocytes results in higher levels of intracellular ROS that may increase melanoma susceptibility.

  10. Multiple pigment cell types contribute to the black, blue, and orange ornaments of male guppies (Poecilia reticulata).

    Science.gov (United States)

    Kottler, Verena A; Koch, Iris; Flötenmeyer, Matthias; Hashimoto, Hisashi; Weigel, Detlef; Dreyer, Christine

    2014-01-01

    The fitness of male guppies (Poecilia reticulata) highly depends on the size and number of their black, blue, and orange ornaments. Recently, progress has been made regarding the genetic mechanisms underlying male guppy pigment pattern formation, but we still know little about the pigment cell organization within these ornaments. Here, we investigate the pigment cell distribution within the black, blue, and orange trunk spots and selected fin color patterns of guppy males from three genetically divergent strains using transmission electron microscopy. We identified three types of pigment cells and found that at least two of these contribute to each color trait. Further, two pigment cell layers, one in the dermis and the other in the hypodermis, contribute to each trunk spot. The pigment cell organization within the black and orange trunk spots was similar between strains. The presence of iridophores in each of the investigated color traits is consistent with a key role for this pigment cell type in guppy color pattern formation.

  11. Long-term changes in pigmentation of arctic Daphnia provide potential for reconstructing aquatic UV exposure

    Science.gov (United States)

    Nevalainen, Liisa; Rantala, Marttiina V.; Luoto, Tomi P.; Ojala, Antti E. K.; Rautio, Milla

    2016-07-01

    Despite the biologically damaging impacts of solar ultraviolet radiation (UV) in nature, little is known about its natural variability, forcing mechanisms, and long-term effects on ecosystems and organisms. Arctic zooplankton, for example the aquatic keystone genus Daphnia (Crustacea, Cladocera) responds to biologically damaging UV by utilizing photoprotective strategies, including pigmentation. We examined the preservation and content of UV-screening pigments in fossil Daphnia remains (ephippia) in two arctic lake sediment cores from Cornwallis Island (Lake R1), Canada, and Spitsbergen (Lake Fugledammen), Svalbard. The aims were to document changes in the degree of UV-protective pigmentation throughout the past centuries, elucidate the adaptive responses of zooplankton to long-term variations in UV exposure, and estimate the potential of fossil zooplankton pigments in reconstructing aquatic UV regimes. The spectroscopic absorbance measurements of fossil Daphnia ephippia under UV (280-400 nm) and visible light (400-700 nm) spectral ranges indicated that melanin (absorbance maxima at UV wavebands 280-350 nm) and carotenoids (absorbance maxima at 400-450 nm) pigments were preserved in the ephippia in both sediment cores. Downcore measurements of the most important UV-protective pigment melanin (absorbance measured at 305 and 340 nm) showed marked long-term variations in the degree of melanisation. These variations likely represented long-term trends in aquatic UV exposure and were positively related with solar radiation intensity. The corresponding trends in melanisation and solar activity were disrupted at the turn of the 20th century in R1, but remained as strong in Fugledammen. The reversed trends in the R1 core were simultaneous with a significant aquatic community reorganization taking place in the lake, suggesting that recent environmental changes, likely related to climate warming had a local effect on pigmentation strategies. This time horizon is also

  12. Role of ocular melanin in ocular drug delivery%眼内色素在眼部药物传递中的作用

    Institute of Scientific and Technical Information of China (English)

    兰碧菲

    2014-01-01

    Ocular melanin is mainly distributed in the uveal tract (including iris,ciliary body and choroid) and the retina pigmented epithelial (RPE) layer.Many drugs from different therapeutic classes can bind to melanin.Examples include antibiotics,anesthetics,β-blockers,corticosteroids,antimalarial drugs and so on.The critical factors are the acid/base status and the lipophilicity of the molecule.Lots of literatures,which refer to pharmacokinetic and pharmacodynamics of drugs from different administration routes,have demonstrated that the binding of drugs to melanin plays an important role in the drug delivery.Not only it may increase initial concentration of drug in the tissues,but also the reversible binding of most drugs to melanin result in a slow release of drugs from melanin,thus it would prolong the action time to potentially beneficial or adverse effects.In addition,the melanin content differs by species and races,even by regions of an eye,which results in different binding capacity of a drug in each individual.Nonetheless,further understanding the melanin-drug binding can provide scientific insight and guideline for transscleral ocular drug delivery.%眼内色素主要存在于葡萄膜(包括虹膜、睫状体、脉络膜)和视网膜色素上皮(RPE)层,它能与很多不同类型的药物结合,如抗生素、麻醉剂、β-受体阻滞剂、糖皮质激素和抗疟药等,结合的关键在于药物的酸碱度和脂溶性.通过研究药物在不同给药途径中的药代动力学和药效学,发现眼内色素与药物的结合在眼部药物传递中起重要的作用.它不仅可以提高药物在组织中的初始浓度,而且色素与大部分药物的结合是可逆的,使得药物可以从色素中缓慢释放而延长药物的作用时间,产生有利或不利的影响.由于不同的药物与色素的结合力不同,且在不同的物种和种族,甚至同一组织的不同区域中眼内色素的含量都有区别,使得药物与色素的结合

  13. Multimodal microscopy and the stepwise multi-photon activation fluorescence of melanin

    Science.gov (United States)

    Lai, Zhenhua

    The author's work is divided into three aspects: multimodal microscopy, stepwise multi-photon activation fluorescence (SMPAF) of melanin, and customized-profile lenses (CPL) for on-axis laser scanners, which will be introduced respectively. A multimodal microscope provides the ability to image samples with multiple modalities on the same stage, which incorporates the benefits of all modalities. The multimodal microscopes developed in this dissertation are the Keck 3D fusion multimodal microscope 2.0 (3DFM 2.0), upgraded from the old 3DFM with improved performance and flexibility, and the multimodal microscope for targeting small particles (the "Target" system). The control systems developed for both microscopes are low-cost and easy-to-build, with all components off-the-shelf. The control system have not only significantly decreased the complexity and size of the microscope, but also increased the pixel resolution and flexibility. The SMPAF of melanin, activated by a continuous-wave (CW) mode near-infrared (NIR) laser, has potential applications for a low-cost and reliable method of detecting melanin. The photophysics of melanin SMPAF has been studied by theoretical analysis of the excitation process and investigation of the spectra, activation threshold, and photon number absorption of melanin SMPAF. SMPAF images of melanin in mouse hair and skin, mouse melanoma, and human black and white hairs are compared with images taken by conventional multi-photon fluorescence microscopy (MPFM) and confocal reflectance microscopy (CRM). SMPAF images significantly increase specificity and demonstrate the potential to increase sensitivity for melanin detection compared to MPFM images and CRM images. Employing melanin SMPAF imaging to detect melanin inside human skin in vivo has been demonstrated, which proves the effectiveness of melanin detection using SMPAF for medical purposes. Selective melanin ablation with micrometer resolution has been presented using the Target system

  14. Evaluation of patient response and recurrence of pigmentation following gingival depigmentation using laser and scalpel technique: A clinical study

    Directory of Open Access Journals (Sweden)

    Harpreet Singh Grover

    2014-01-01

    Full Text Available Aim: The present study was undertaken to evaluate patient response and recurrence of pigmentation following gingival depigmentation carried out with a surgical blade and diode laser. Materials and Methods: Twenty patients who were esthetically conscious of their dark gums and requested treatment for the same were selected for this study. Complete phase I therapy was performed for all the patients before performing the gingival depigmentation procedures with laser and scalpel on a split-mouth basis. Patients were evaluated for pain (1 day, 1 week, wound healing and melanin repigmentation (Melanin Pigmentation Index immediately and at 1 week, 1 month and 3 months, respectively. Results: The final results were statistically analyzed and significance was evaluated. The results of this study indicated that both scalpel and laser were efficient for gingival depigmentation. Comparative pain assessment (P = 0.148 and repigmentation scores (P = 0.288 at various time intervals between the two groups did not show any statistical significance. Conclusion: Both the procedures did not result in any post-operative complications and the gingiva healed uneventfully. When compared, both the techniques were found to be equally efficacious. Care must be taken to assess the gingival biotype and the degree of pigmentation in deciding which technique is to be used. Clinical Significance: Various methods of depigmentation are available with comparable efficacies. Depigmentation is not a clinical indication but a treatment of choice where esthetics is a concern and is desired by the patient.

  15. Outbreak of extensively drug-resistant Acinetobacter baumannii indigo-pigmented strains

    OpenAIRE

    Vilacoba, Elisabet; Almuzara, Marisa; Gulone, Lucia; Rodriguez, Rocio; Pallone, Elida; Bakai, Romina; Centron, Daniela; Ramirez, Maria Soledad

    2016-01-01

    Acinetobacter baumannii pigmented strains are not common in clinical settings. In the present work we report an outbreak caused by indigo-pigmented A. baumannii strains isolated in an acute hospital in Argentina from March to September 2012. Pan-PCR assays exposed a unique pattern belonging to the recently described regional CC113B/CC79P that confirms the relevant relationships among the indigo-pigmented A. baumannii strains. All of them were extensively drug-resistant and harbored different ...

  16. Data on melanin production in B16F1 melanoma cells in the presence of emu oil

    Directory of Open Access Journals (Sweden)

    Minoru Ito

    2016-12-01

    Full Text Available Here, we present data on the effects of emu oil, obtained from emu (Dromaius novaehollandiae fat deposits, on melanogenesis in B16F1 murine melanoma cells. The cells were cultured in media containing different concentrations of emu oil, and the melanin content of these cells was measured using a microplate reader. Next, melanin content was measured for cells cultured with α-melanocyte-stimulating hormone. This article reports the different melanin contents as μg melanin/mg cellular protein, by using bar graphs with error bars. The present data imply that emu oil reduces the cellular melanin production.

  17. Inhibitory effect of 2,4,2',4'-tetrahydroxy-3-(3-methyl-2-butenyl)-chalcone on tyrosinase activity and melanin biosynthesis.

    Science.gov (United States)

    Zhang, Xiaodong; Hu, Xiao; Hou, Aijun; Wang, Heyao

    2009-01-01

    2,4,2',4'-Tetrahydroxy-3-(3-methyl-2-butenyl)-chalcone (TMBC), a naturally occurring compound from Morus nigra, modulated melanogenesis by inhibiting tyrosinase. TMBC inhibited the L-dopa oxidase activity of mushroom tyrosinase with an IC(50) value of 0.95+/-0.04 microM, which was more potent than kojic acid (IC(50)=24.88+/-1.13 microM), a well-known tyrosinase inhibitor. The kinetic studies of tyrosinase inhibition revealed that TMBC acts as a competitive inhibitor of mushroom tyrosinase with L-dopa as the substrate. Furthermore, TMBC effectively inhibited both cellular tyrosinase activity and melanin biosynthesis in B16 melanoma cells without significant cytotoxicity. The inhibitory effect of TMBC on melanogenesis was attributed to the direct inhibition of tyrosinase activity, rather than the suppression of tyrosinase gene expression. These results indicated that TMBC may be a new promising pigmentation-altering agent for cosmetic or therapeutic applications.

  18. Viability of brown trout embryos positively linked to melanin-based but negatively to carotenoid-based colours of their fathers.

    Science.gov (United States)

    Wedekind, Claus; Jacob, Alain; Evanno, Guillaume; Nusslé, Sébastien; Müller, Rudolf

    2008-08-07

    'Good-genes' models of sexual selection predict significant additive genetic variation for fitness-correlated traits within populations to be revealed by phenotypic traits. To test this prediction, we sampled brown trout (Salmo trutta) from their natural spawning place, analysed their carotenoid-based red and melanin-based dark skin colours and tested whether these colours can be used to predict offspring viability. We produced half-sib families by in vitro fertilization, reared the resulting embryos under standardized conditions, released the hatchlings into a streamlet and identified the surviving juveniles 20 months later with microsatellite markers. Embryo viability was revealed by the sires' dark pigmentation: darker males sired more viable offspring. However, the sires' red coloration correlated negatively with embryo survival. Our study demonstrates that genetic variation for fitness-correlated traits is revealed by male colour traits in our study population, but contrary to predictions from other studies, intense red colours do not signal good genes.

  19. Characterization of pigmented dermo-epidermal skin substitutes in a long-term in vivo assay.

    Science.gov (United States)

    Böttcher-Haberzeth, Sophie; Biedermann, Thomas; Klar, Agnieszka S; Widmer, Daniel S; Neuhaus, Kathrin; Schiestl, Clemens; Meuli, Martin; Reichmann, Ernst

    2015-01-01

    In our laboratory, we have been using human pigmented dermo-epidermal skin substitutes for short-term experiments since several years. Little is known, however, about the long-term biology of such constructs after transplantation. We constructed human, melanocyte-containing dermo-epidermal skin substitutes of different (light and dark) pigmentation types and studied them in a long-term animal experiment. Developmental and maturational stages of the epidermal and dermal compartment as well as signs of homoeostasis were analysed 15 weeks after transplantation. Keratinocytes, melanocytes and fibroblasts from human skin biopsies were isolated and assembled into dermo-epidermal skin substitutes. These were transplanted onto immuno-incompetent rats and investigated 15 weeks after transplantation. Chromameter evaluation showed a consistent skin colour between 3 and 4 months after transplantation. Melanocytes resided in the epidermal basal layer in physiological numbers and melanin accumulated in keratinocytes in a supranuclear position. Skin substitutes showed a mature epidermis in a homoeostatic state and the presence of dermal components such as Fibrillin and Tropoelastin suggested advanced maturation. Overall, pigmented dermo-epidermal skin substitutes show a promising development towards achieving near-normal skin characteristics and epidermal and dermal tissue homoeostasis. In particular, melanocytes function correctly over several months whilst remaining in a physiological, epidermal position and yield a pigmentation resembling original donor skin colour. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Carney complex: the complex of myxomas, spotty pigmentation, endocrine overactivity, and schwannomas.

    Science.gov (United States)

    Carney, J A

    1995-06-01

    The complex of myxomas, spotty pigmentation, endocrine overactivity, and schwannomas (the Carney complex) is a multisystem tumorous disorder that is transmitted as a mendelian autosomal dominant trait. Approximately 150 affected patients are known worldwide. The myxomas, which tend to be multiple in the involved organ, affect the heart, skin and breast. Typical sites for the skin myxomas are the eyelids, external ear canal, and nipples. The lesions commonly recur after excision. The spotty skin pigmentation includes lentigines and blue nevi, but ephelides and junctional and compound nevi also occur. The lentigines are widespread and typically involve the centrofacial area, including the vermilion border of the lips, and the conjunctiva, especially the lacrimal caruncle and the conjunctival semilunar fold. One or more intraoral pigmented spots are seen occasionally. The blue nevi occur on the face, trunk, and limbs, but not the hands and feet. Endocrine overactivity includes Cushing's syndrome (caused by primary pigmented nodular adrenocortical disease), acromegaly (caused by growth hormone-producing pituitary adenoma), and sexual precocity (caused by large-cell calcifying Sertoli cell tumor). The schwannomas are a special histological type, featuring psammoma bodies and melanin. Most commonly, they affect the upper gastrointestinal tract and sympathetic nerve chains, but a few have occurred in the skin. The most serious component of the Carney complex is cardiac myxoma. Patients suspected of having the syndrome (and their primary relatives) should be examined for this neoplasm.

  1. Comparing in vivo pump-probe and multiphoton fluorescence microscopy of melanoma and pigmented lesions

    Science.gov (United States)

    Wilson, Jesse W.; Degan, Simone; Gainey, Christina S.; Mitropoulos, Tanya; Simpson, Mary Jane; Zhang, Jennifer Y.; Warren, Warren S.

    2015-05-01

    We demonstrate a multimodal approach that combines a pump-probe with confocal reflectance and multiphoton autofluorescence microscopy. Pump-probe microscopy has been proven to be of great value in analyzing thin tissue sections of pigmented lesions, as it produces molecular contrast which is inaccessible by other means. However, the higher optical intensity required to overcome scattering in thick tissue leads to higher-order nonlinearities in the optical response of melanin (e.g., two-photon pump and one-photon probe) that present additional challenges for interpreting the data. We show that analysis of pigment composition in vivo must carefully account for signal terms that are nonlinear with respect to the pump and probe intensities. We find that pump-probe imaging gives useful contrast for pigmented structures over a large range of spatial scales (100 μm to 1 cm), making it a potentially useful tool for tracking the progression of pigmented lesions without the need to introduce exogenous contrast agents.

  2. Syndecan-2 regulates melanin synthesis via protein kinase C βII-mediated tyrosinase activation.

    Science.gov (United States)

    Jung, Hyejung; Chung, Heesung; Chang, Sung Eun; Choi, Sora; Han, Inn-Oc; Kang, Duk-Hee; Oh, Eok-Soo

    2014-05-01

    Syndecan-2, a transmembrane heparan sulfate proteoglycan that is highly expressed in melanoma cells, regulates melanoma cell functions (e.g. migration). Since melanoma is a malignant tumor of melanocytes, which largely function to synthesize melanin, we investigated the possible involvement of syndecan-2 in melanogenesis. Syndecan-2 expression was increased in human skin melanoma tissues compared with normal skin. In both mouse and human melanoma cells, siRNA-mediated knockdown of syndecan-2 was associated with reduced melanin synthesis, whereas overexpression of syndecan-2 increased melanin synthesis. Similar effects were also detected in human primary epidermal melanocytes. Syndecan-2 expression did not affect the expression of tyrosinase, a key enzyme in melanin synthesis, but instead enhanced the enzymatic activity of tyrosinase by increasing the membrane and melanosome localization of its regulator, protein kinase CβII. Furthermore, UVB caused increased syndecan-2 expression, and this up-regulation of syndecan-2 was required for UVB-induced melanin synthesis. Taken together, these data suggest that syndecan-2 regulates melanin synthesis and could be a potential therapeutic target for treating melanin-associated diseases. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Stepwise multiphoton activation fluorescence reveals a new method of melanin detection

    Science.gov (United States)

    Lai, Zhenhua; Kerimo, Josef; Mega, Yair; DiMarzio, Charles A.

    2013-06-01

    The stepwise multiphoton activated fluorescence (SMPAF) of melanin, activated by a continuous-wave mode near infrared (NIR) laser, reveals a broad spectrum extending from the visible spectra to the NIR and has potential application for a low-cost, reliable method of detecting melanin. SMPAF images of melanin in mouse hair and skin are compared with conventional multiphoton fluorescence microscopy and confocal reflectance microscopy (CRM). By combining CRM with SMPAF, we can locate melanin reliably. However, we have the added benefit of eliminating background interference from other components inside mouse hair and skin. The melanin SMPAF signal from the mouse hair is a mixture of a two-photon process and a third-order process. The melanin SMPAF emission spectrum is activated by a 1505.9-nm laser light, and the resulting spectrum has a peak at 960 nm. The discovery of the emission peak may lead to a more energy-efficient method of background-free melanin detection with less photo-bleaching.

  4. Production of natural melanin by Auricularia auricula and study on its molecular structure.

    Science.gov (United States)

    Sun, Shujing; Zhang, Xiaojuan; Sun, Shiwei; Zhang, Liaoyuan; Shan, Shukai; Zhu, Hu

    2016-01-01

    In this study, the production and structure of melanin produced by Auricularia auricula have been determined and analyzed in detail. The results showed that the highest mycelial growth rate was observed in low-carbon and carbon-free medium. In low-nitrogen and nitrogen-free medium, melanin yield was very low. Deficiency of tyrosine in medium led to weak secretion of melanin. The inorganic salt could markedly influence mycelia morphology, but did not obviously impact mycelia growth rate and melanin yield. Meanwhile the condensed molecular formula ([C18(OR)3H7O4N2]n) and structural formula of melanin were concluded based on UV-Vis, HPLC, FTIR, NMR and elemental assay. This is an eumelanin and also a macromolecular polymer of 5,6-dihydroxyindole and 5,6-dihydroxyindole-2-carboxylic acid. The 6 main components were phenolic hydroxyl, carboxyl, amidogen, carbonyl, methylene, methyne and sulfur. This work testified that nutritional control was very important to promote melanin production, making melanin more affordable as material in food, cosmetics and medicines.

  5. Stepwise multiphoton activation fluorescence reveals a new method of melanin detection.

    Science.gov (United States)

    Lai, Zhenhua; Kerimo, Josef; Mega, Yair; Dimarzio, Charles A

    2013-06-01

    The stepwise multiphoton activated fluorescence (SMPAF) of melanin, activated by a continuous-wave mode near infrared (NIR) laser, reveals a broad spectrum extending from the visible spectra to the NIR and has potential application for a low-cost, reliable method of detecting melanin. SMPAF images of melanin in mouse hair and skin are compared with conventional multiphoton fluorescence microscopy and confocal reflectance microscopy (CRM). By combining CRM with SMPAF, we can locate melanin reliably. However, we have the added benefit of eliminating background interference from other components inside mouse hair and skin. The melanin SMPAF signal from the mouse hair is a mixture of a two-photon process and a third-order process. The melanin SMPAF emission spectrum is activated by a 1505.9-nm laser light, and the resulting spectrum has a peak at 960 nm. The discovery of the emission peak may lead to a more energy-efficient method of background-free melanin detection with less photo-bleaching.

  6. 黄褐斑:表皮屏障与黑素屏障失衡%Melasma: the imbalance between epidermal barrier and melanin barrier

    Institute of Scientific and Technical Information of China (English)

    宋秀祖; 许爱娥

    2012-01-01

    黄褐斑是一种面部获得性色素增加性皮肤病,发病机制尚不清,概述黄褐斑的表皮屏障及黑素屏障的变化,以及真皮血管的变化.在此基础上推测黄褐斑的可能发病机制为紫外线、化妆品、避孕药等不良刺激导致表皮屏障功能障碍,代偿性引起黑素细胞功能活跃,黑素屏障增强,形成临床上表现为色素沉着为主的皮肤病.进一步导致真皮毛细血管扩张,血管内皮生长因子表达增加,促进色素沉着发生.%Melasma is an acquired skin disease characterized by facial hyperpigmentation of unclear pathogenesis.This paper describes the changes of epidermal barrier,melanin barrier and dermal blood vessels in melasma.On this basis,the pathogenesis of melasma is speculated to be associated with ultraviolet,cosmetics,contraceptives and other adverse stimuli,which cause epidermal barrier dysfunction,lead to a compensatory increase in melanocyte activity and melanin barrier followed by the occurrence of diseases characterized by skin pigmentation.Moreover,dermal telangiectasis is induced and vascular endothelial growth factor expression is enhanced,which accelerate skin pigmentation accordingly.

  7. The role of alpha-synuclein in melanin synthesis in melanoma and dopaminergic neuronal cells.

    Directory of Open Access Journals (Sweden)

    Tianhong Pan

    Full Text Available The relatively high co-occurrence of Parkinson's disease (PD and melanoma has been established by a large number of epidemiological studies. However, a clear biological explanation for this finding is still lacking. Ultra-violet radiation (UVR-induced skin melanin synthesis is a defense mechanism against UVR-induced damage relevant to the initiation of melanoma, whereas, increased neuromelanin (NM, the melanin synthesized in dopaminergic neurons, may enhance the susceptibility to oxidative stress-induced neuronal injury relevant to PD. SNCA is a PD-causing gene coding for alpha-Synuclein (α-Syn that expresses not only in brain, but also in skin as well as in tumors, such as melanoma. The findings that α-Syn can interact with tyrosinase (TYR and inhibit tyrosine hydroxylase (TH, both of which are enzymes involved in the biosynthesis of melanin and dopamine (DA, led us to propose that α-Syn may participate in the regulation of melanin synthesis. In this study, by applying ultraviolet B (UVB light, a physiologically relevant stimulus of melanogenesis, we detected melanin synthesis in A375 and SK-MEL-28 melanoma cells and in SH-SY5Y and PC12 dopaminergic neuronal cells and determined effects of α-Syn on melanin synthesis. Our results showed that UVB light exposure increased melanin synthesis in all 4 cell lines. However, we found that α-Syn expression reduced UVB light-induced increase of melanin synthesis and that melanin content was lower when melanoma cells were expressed with α-Syn, indicating that α-Syn may have inhibitory effects on melanin synthesis in melanoma cells. Different from melanoma cells, the melanin content was higher in α-Syn-over-expressed dopaminergic neuronal SH-SY5Y and PC12 cells, cellular models of PD, than that in non-α-Syn-expressed control cells. We concluded that α-Syn could be one of the points responsible for the positive association between PD and melanoma via its differential roles in melanin synthesis in

  8. Natural pigments and sacred art

    Science.gov (United States)

    Kelekian, Lena, ,, Lady

    2010-05-01

    Since the dawn of mankind, cavemen has expressed himself through art. The earliest known cave paintings date to some 32,000 years ago and used 4 colours derived from the earth. These pigments were iron oxides and known as ochres, blacks and whites. All pigments known by the Egyptians, the Greeks, the Romans and Renaissance man were natural and it was not until the 18th century that synthetic pigments were made and widely used. Until that time all art, be it sacred or secular used only natural pigments, of which the preparation of many have been lost or rarely used because of their tedious preparation. As a geologist, a mineralogist and an artist specializing in iconography, I have been able to rediscover 89 natural pigments extracted from minerals. I use these pigments to paint my icons in the traditional Byzantine manner and also to restore old icons, bringing back their glamour and conserving them for years to come. The use of the natural pigments in its proper way also helps to preserve the traditional skills of the iconographer. In the ancient past, pigments were extremely precious. Many took an exceedingly long journey to reach the artists, and came from remote countries. Research into these pigments is the work of history, geography and anthropology. It is an interesting journey in itself to discover that the blue aquamarines came from Afghanistan, the reds from Spain, the greens Africa, and so on. In this contribution I will be describing the origins, preparation and use of some natural pigments, together with their history and provenance. Additionally, I will show how the natural pigments are used in the creation of an icon. Being a geologist iconographer, for me, is a sacrement that transforms that which is earthly, material and natural into a thing of beauty that is sacred. As bread and wine in the Eucharist, water during baptism and oil in Holy Union transmit sanctification to the beholder, natural pigments do the same when one considers an icon. The

  9. Melanin precursor 5,6-dihydroxyindol: protective effects and cytotoxicity on retinal cells in vitro and in vivo.

    Science.gov (United States)

    Heiduschka, Peter; Blitgen-Heinecke, Petra; Tura, Aysegül; Kokkinou, Despina; Julien, Sylvie; Hofmeister, Sabine; Bartz-Schmidt, Karl Ulrich; Schraermeyer, Ulrich

    2007-12-01

    5,6-dihydroxyindole (DHI) is a melanin pigment precursor with antioxidant properties. In the light of a report about cytotoxicity of DHI, the aim of this study was to assess possible toxic effects of DHI on cells related to the eye, such as human ARPE-19 cells and mouse retinal explants. Moreover, DHI was tested on its effects on retinal function in vivo using electroretinography. We found cytotoxicity of DHI against ARPE-19 cells at 100 microM, but not at 10 microM. 10 microM DHI exhibited a slight, though not significant protective activity against UV-A damage in ARPE-19 cells. We found cytoprotection in cultured mouse retinas by 50 microM DHI or its diacetylated derivative 5,6-diacetoxyindole (DAI), respectively. In ERG measurements in vivo, amplitudes were decreased only slightly by 100 microM DHI compared to saline, whereas a better preservation of amplitudes was visible at 10 microM DHI, in particular with respect to cones. In histological sections, more cones were found at 10 microM DHI than at 100 microM DHI. As a conclusion, DHI shows a slight protective effect at 10 microM both in vitro and in vivo. At 100 microM, it shows a strong cytotoxicity in vitro, which is strongly reduced in vivo.

  10. The challenges and limitations of chemical analysis of particulate pigments of very low solubility.

    Science.gov (United States)

    Olsen, Ole

    2015-01-01

    When performing a chemical analysis of colorants in tattoo products, specific degradation products as well as impurity patterns can be predicted. Mislabeling or false declarations can also be avoided using this test. It is notable that pigment identification in tattoo products may serve as a precursory technique to recognize the colorants contained in a patient's tattoo prior to laser removal therapy. In contrast to the analysis of banned pigments, positive identification of pigments will normally require few reference substances. Given the fact that tattoo pigments are nearly insoluble in water and many organic solvents, different chemical pigment analyses are outlined and evaluated. Related publications from the study of art are also mentioned. It is recommended that access to comprehensive pigment standards and spectroscopic databanks should be offered to laboratories dealing with tattoo product analysis in the future.

  11. Lasers in esthetic treatment of gingival melanin hyperpigmentation: a review article.

    Science.gov (United States)

    Bakhshi, Mahin; Rahmani, Somayeh; Rahmani, Ali

    2015-11-01

    The health and suitability of mouth components play an important role towards defining facial attractiveness. An important component of the oral cavity is the color of the gingival tissue. Gingival melanin hyperpigmentation is caused by several reasons and affects people across ethnicity, race, age, and both gender. Lasers are presently being used for gingival melanin depigmentation. In this article, we reviewed studies on laser parameters, duration of gingival healing, pain perception during and after the operation, scores used for the evaluation of gingival melanin hyperpigmentation, follow-up period, treatment results, and recurrence reports. We conclude that laser ablation for gingival depigmentation is one of the most pleasant, reliable, acceptable, and impressive techniques available for treating gingival melanin hyperpigmentation.

  12. Melanin concentrating hormone receptor 1 (MCHR1) antagonists - Still a viable approach for obesity treatment?

    DEFF Research Database (Denmark)

    Högberg, T.; Frimurer, T.M.; Sasmal, P.K.

    2012-01-01

    Obesity is a global epidemic associated with multiple severe diseases. Several pharmacotherapies have been investigated including the melanin concentrating hormone (MCH) and its receptor 1. The development of MCHR1 antagonists are described with a specific perspective on different chemotypes...

  13. Bio-Inspired Structural Colors Produced via Self-Assembly of Synthetic Melanin Nanoparticles.

    Science.gov (United States)

    Xiao, Ming; Li, Yiwen; Allen, Michael C; Deheyn, Dimitri D; Yue, Xiujun; Zhao, Jiuzhou; Gianneschi, Nathan C; Shawkey, Matthew D; Dhinojwala, Ali

    2015-05-26

    Structural colors arising from interactions of light with submicron scale periodic structures have been found in many species across all taxa, serving multiple biological functions including sexual signaling, camouflage, and aposematism. Directly inspired by the extensive use of self-assembled melanosomes to produce colors in avian feathers, we set out to synthesize and assemble polydopamine-based synthetic melanin nanoparticles in an effort to fabricate colored films. We have quantitatively demonstrated that synthetic melanin nanoparticles have a high refractive index and broad absorption spanning across the UV-visible range, similar to natural melanins. Utilizing a thin-film interference model, we demonstrated the coloration mechanism of deposited films and showed that the unique optical properties of synthetic melanin nanoparticles provide advantages for structural colors over other polymeric nanoparticles (i.e., polystyrene colloidal particles).

  14. Melanin and blood concentration in human skin studied by multiple regression analysis: experiments

    Science.gov (United States)

    Shimada, M.; Yamada, Y.; Itoh, M.; Yatagai, T.

    2001-09-01

    Knowledge of the mechanism of human skin colour and measurement of melanin and blood concentration in human skin are needed in the medical and cosmetic fields. The absorbance spectrum from reflectance at the visible wavelength of human skin increases under several conditions such as a sunburn or scalding. The change of the absorbance spectrum from reflectance including the scattering effect does not correspond to the molar absorption spectrum of melanin and blood. The modified Beer-Lambert law is applied to the change in the absorbance spectrum from reflectance of human skin as the change in melanin and blood is assumed to be small. The concentration of melanin and blood was estimated from the absorbance spectrum reflectance of human skin using multiple regression analysis. Estimated concentrations were compared with the measured one in a phantom experiment and this method was applied to in vivo skin.

  15. Natural melanin: a potential pH-responsive drug release device.

    Science.gov (United States)

    Araújo, Marco; Viveiros, Raquel; Correia, Tiago R; Correia, Ilídio J; Bonifácio, Vasco D B; Casimiro, Teresa; Aguiar-Ricardo, Ana

    2014-07-20

    This work proposes melanin as a new nanocarrier for pH-responsive drug release. Melanin is an abundant natural polymer that can be easily extracted from cuttlefish as nanoparticles with a suitable size range for drug delivery. However, despite its high potentiality, the application of this biopolymer in the pharmaceutical and biomedical fields is yet to be explored. Herein, melanin nanoparticles were impregnated with metronidazole, chosen as model antibiotic drug, using supercritical carbon dioxide. The drug release profile was investigated at acidic and physiologic pH, and the dominant mechanism was found to follow a non-Fickian transport. Drug release from melanin shows a strong pH dependency, which allied to its biocompatibility and lack of cytotoxicity envisages its potential application as nanocarrier in formulations for colon and intestine targeted drug delivery.

  16. Quick analysis of optical spectra to quantify epidermal melanin and papillary dermal blood content of skin.

    Science.gov (United States)

    Jacques, Steven L

    2015-04-01

    This paper presents a practical approach for assessing the melanin and blood content of the skin from total diffuse reflectance spectra, R(λ), where λ is wavelength. A quick spectral analysis using just three wavelengths (585 nm, 700 nm and 800 nm) is presented, based on the 1985 work of Kollias and Baquer who documented epidermal melanin of skin using the slope of optical density (OD) between 620 nm and 720 nm. The paper describes the non-rectilinear character of such a quick analysis, and shows that almost any choice of two wavelengths in the 600-900 range can achieve the characterization of melanin. The extrapolation of the melanin slope to 585 nm serves as a baseline for subtraction from the OD (585 nm) to yield a blood perfusion score. Monte Carlo simulations created spectral data for a skin model with epidermis, papillary dermis and reticular dermis to illustrate the analysis.

  17. The role of melanin as protector against free radicals in skin and its role as free radical indicator in hair

    Science.gov (United States)

    Herrling, Thomas; Jung, Katinka; Fuchs, Jürgen

    2008-05-01

    Throughout the body, melanin is a homogenous biological polymer containing a population of intrinsic, semiquinone-like radicals. Additional extrinsic free radicals are reversibly photo-generated by UV and visible light. Melanin photochemistry, particularly the formation and decay of extrinsic radicals, has been the subject of numerous electron spin resonance (ESR) spectroscopy studies. Several melanin monomers exist, and the predominant monomer in a melanin polymer depends on its location within an organism. In skin and hair, melanin differs in content of eumelanin or pheomelanin. Its bioradical character and its susceptibility to UV irradiation makes melanin an excellent indicator for UV-related processes in both skin and hair. The existence of melanin in skin is strongly correlated with the prevention against free radicals/ROS generated by UV radiation. Especially in the skin melanin (mainly eumelanin) ensures the only natural UV protection by eliminating the generated free radicals/ROS. Melanin in hair can be used as a free radical detector for evaluating the efficacy of hair care products. The aim of this study was to investigate the suitability of melanin as protector of skin against UV generated free radicals and as free radical indicator in hair.

  18. Examination by EPR spectroscopy of free radicals in melanins isolated from A-375 cells exposed on valproic acid and cisplatin.

    Science.gov (United States)

    Chodurek, Ewa; Zdybel, Magdalena; Pilawa, Barbara; Dzierzewicz, Zofia

    2012-01-01

    Drug binding by melanin biopolymers influence the effectiveness of the chemotherapy, radiotherapy and photodynamic therapy. Free radicals of melanins take part in formation of their complex with drugs. The aim of this work was to determine the effect of the two compounds: valproic acid (VPA) and cisplatin (CPT) on free radicals properties of melanin isolated from A-375 melanoma cells. Free radicals were examined by an X-band (9.3 GHz) electron paramagnetic resonance (EPR) spectroscopy. EPR spectra were measured for the model synthetic eumelanin - DOPA-melanin, the melanin isolated from the control A-375 cells and these cells treated by VPA, CPT and both VPA and CPT. For all the examined samples broad EPR lines (deltaBpp: 0.48-0.68 mT) with g-factors of 2.0045-2.0060 characteristic for o-semiquinone free radicals were observed. Free radicals concentrations (N) in the tested samples, g-factors, amplitudes (A), integral intensities (I) and linewidths (deltaBpp) of the EPR spectra, were analyzed. The EPR lines were homogeneously broadened. Continuous microwave saturation of the EPR spectra indicated that slow spin-lattice relaxation processes existed in all the tested melanin samples. The relatively slowest spin-lattice relaxation processes characterized melanin isolated from A-375 cells treated with both VPA and CPT. The changes of the EPR spectra with increasing microwave power in the range of 2.2-70 mW were evaluated. Free radicals concentrations in the melanin from A-375 cells were higher than in the synthetic DOPA-melanin. The strong increase of free radicals concentration in the melanin from A-375 cells was observed after their treating by VPA. CPT also caused the increase of free radicals concentrations in the examined natural melanin. The free radicals concentration in melanin isolated from A-375 cells treated with both VPA and CPT was slightly higher than those in melanin from the control cells.

  19. KHG26792 Inhibits Melanin Synthesis in Mel-Ab Cells and a Skin Equivalent Model

    OpenAIRE

    Li, Hailan; Kim, Jandi; Hahn, Hoh-Gyu; Yun, Jun; Jeong, Hyo-Soon; Yun, Hye-Young; Baek, Kwang Jin; Kwon, Nyoun Soo; Min, Young Sil; Park, Kyoung-Chan; Kim, Dong-Seok

    2014-01-01

    The purpose of this study is to characterize the effects of KHG26792 (3-(naphthalen-2-yl(propoxy) methyl)azetidine hydrochloride), a potential skin whitening agent, on melanin synthesis and identify the underlying mechanism of action. Our data showed that KHG26792 significantly reduced melanin synthesis in a dose-dependent manner. Additionally, KHG26792 downregulated microphthalmia-associated transcription factor (MITF) and tyrosinase, the rate-limiting enzyme in melanogenesis, although tyros...

  20. 21 CFR 178.3725 - Pigment dispersants.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Pigment dispersants. 178.3725 Section 178.3725 Food... regulation, the substances listed in this section may be safely used as pigment dispersants in food-contact... not to exceed 0.45 percent by weight of the pigment. The pigmented articles may contact all...

  1. Comparison of antioxidation systems of retinal pigment epithelium of pigmented and albino animals

    Energy Technology Data Exchange (ETDEWEB)

    Sakina, N.L.; Dontsov, A.E.; Ostrovskiy, M.A.

    1985-01-01

    The effectiveness of the lipid peroxidation inhibition process by tissue homogenates of retinal pigment epithelium of pigmented rabbits is higher than that of albino rabbits. The superoxide dismutase and glutathione perioxidase activity is nearly the same in both tissues of the pigment epithelium, the ..cap alpha..-tocopherol content is higher in retinal pigment epithelium tissue of albino animals, and the oxidizability of the lipid fraction of pigment epithelium tissue is higher in pigmented animals than in albinos. It is concluded that the higher resistance of the pigment epithelium of pigmented animals to the effects of prooxidant systems is due to the presence of melanoprotein granules in the pigment epithelium.

  2. Efektivitas kurkumin sebagai antioksidan dan inhibitor melanin pada kultur sel B16F1

    Directory of Open Access Journals (Sweden)

    Sugiharto Sugiharto

    2013-03-01

    Full Text Available Melanin inhibitors have become increasingly important ingredients in medication and cosmetics for the prevention ofhyperpigmentation. In the last few years, a huge number of natural herbal extracts have been tested as inhibitors of melanin synthesisand some of these effects are related to the antioxidant properties. The objectives of this study were to determine of curcumin propertiesas antioxidant activity and melanin inhibitors. In this study, our data indicated that antioxidant assay with DPPH showed IC50 was16,05 μg/ml. In the absence of α-MSH (α-Melanocyte Stimulating Hormone, melanin content assay in cell B16-F1 indicated thatthe highest activity of curcumin to reduce melanin content of 45,67% at 25 μg/ml. Meanwhile, in the presence of α-MSH at the sameconcentration indicated that the highest activity was 53,87%. Based on the data, curcumin has potential properties as antioxidantactivity and melanin inhibitor.

  3. Production and Characterization of Melanin by Submerged Culture of Culinary and Medicinal Fungi Auricularia auricula.

    Science.gov (United States)

    Zhang, Min; Xiao, Gongnian; Thring, Ronald W; Chen, Wan; Zhou, Huabin; Yang, Hailong

    2015-05-01

    Natural melanin is of great potential value and application in the fields of pharmacology, cosmetics, and functional foods. In the present study, statistically designed experiments were conducted for the optimization of the media to enhance the production of melanin by submerged culture of Auricularia auricula. Glucose, tyrosine, peptone, and CaCO3 were found to have significant effects (P melanin biosynthesis by a Plackett-Burman experimental design and subsequently optimized using response surface methodology. Optimal media were obtained at the following concentrations: glucose, 0.90 g/L; tyrosine, 6.68 g/L; peptone, 6.99 g/L; and CaCO3, 6.75 g/L. The validity of the optimum media was verified in separate experiments in which the melanin yield of 1008.08 mg/L was obtained under optimum conditions, compared with 306.52 mg/L at other conditions, i.e., a 3.29-fold increase. Furthermore, the important physical and chemical properties of A. auricula melanin were determined. The findings from the present study indicate that large-scale production of natural melanin by submerged culture of A. auricular could be a useful approach.

  4. Preparation of melanin from Catharsius molossus L. and preliminary study on its chemical structure.

    Science.gov (United States)

    Xin, Chao; Ma, Jia-hua; Tan, Cheng-jia; Yang, Zhou; Ye, Feng; Long, Chan; Ye, Shuang; Hou, Da-bin

    2015-04-01

    A great deal of melanin was found in the waste alkali liquor produced by extraction of chitin from Catharsius molossus L. Discarding the lye could harm the environment and cause waste of resources. In this paper, melanin from C. molossus L. was recovered through acid precipitation and purified by pepsin and so on. The purity, chemical composition and structure of the prepared melanin were explored by UV-visible absorption spectroscopy, Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, high resolution (13)C Cross polarization magic angle spinning nuclear magnetic resonance spectroscopy pyrolysis gas chromatography mass spectrometry, X ray diffraction, X ray fluorescence, matrix-assisted laser desorption/ionization time of flight tandem mass spectrometry, thermal analysis, and so on. The results showed that the purity of the prepared melanin was higher than the commercial standard melanin and it was a kind of nanoaggregates composed of a large quantity of 5,6-dihydroxyindole eumelanin and a small amount of phaeomelanin. In addition, the prepared melanin was irregular in shape and its structure could be divided into three levels: advanced structure maintained by polypeptides, substructure maintained by the ferric ion and microstructure. In particular, the smallest structural unit showed the graphite-like layered structure containing five layers linked by non-covalent bonds and each layer mainly consisted of 5,6-dihydroxyindole and its derivatives, which might be connected to each other through various chemical bonds.

  5. Analysis of Indian pigment gallstones

    Energy Technology Data Exchange (ETDEWEB)

    Rautray, T.R. [Department of Physics, National Institute of Technology, Rourkela 769 008, Orissa (India)]. E-mail: tapash77@hotmail.com; Vijayan, V. [Institute of Physics, Bhubaneswar 751 005, Orissa (India); Panigrahi, S. [Department of Physics, National Institute of Technology, Rourkela 769 008, Orissa (India)

    2007-02-15

    Particle induced X-ray emission and particle induced {gamma}-ray emission spectroscopic techniques have been carried out to analyse the elemental concentrations of human pigment gallstone samples from eastern region (Orissa) and southern region (Chennai) of India. It was observed that 18 minor/trace elements namely Na, Mg, Al, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br and Pb were present in the pigment gallstone samples of both the regions. Our study reveals that average concentration of all elements except Ni in south Indian pigment gallstone samples is higher than that of corresponding values in east Indian pigment gallstone samples whereas elements like Al, P, S, Cl and V did not show much variation between these two regions. Fourier transform infra-red analysis was carried out to identify the functional groups and the classification of the pigment type gallstones of both the regions. The thermal behaviour of pigment gallstones was carried out by thermogravimetry-derivative thermogravimetry analysis.

  6. The integument of Psittacosaurus from Liaoning Province, China: taphonomy, epidermal patterns and color of a ceratopsian dinosaur

    Science.gov (United States)

    Lingham-Soliar, Theagarten; Plodowski, Gerhard

    2010-05-01

    Preserved skin of small dinosaurs is rare. Here, a specimen of the ceratopsian dinosaur, Psittacosaurus, presents some of the best preserved epidermal scales observed to date in a relatively small dinosaur, over wide areas extending from the head to the tail. We study the preserved epidermis of SMF R 4970, the different types of scales, color, and patterns, and their respective locations in the body. We use modern application of high-power digital imaging for close-up analysis of the tubercles and fragments of preserved color. Three types of scales are preserved, large plate-like scales, smaller polygonal scales or tubercles, and round pebble-like scales. The sizes of the plate-like scales vary in different parts of the body and vanish altogether posteriorly. Light and dark cryptic patterns are created by the associations of the tubercle and plate-like scales, and there is also evidence of countershading in the proximal caudal region, the body darker dorsally and lighter ventrally. Perhaps most impressive are the distinctive pigmented impressions of scales over most of the skeletal elements. The pigmentation follows the curvature of the bones implying that when it was deposited, the skin was still pliable and able to wrap around the visible parts of the elements. The present record of color is the first in a non-theropod dinosaur and only the second record in a non-avian dinosaur. Because of its resistance to degradation and ability to produce various color tones from yellows to blacks, we suggest that melanin was the dominant chemical involved in the coloration of Psittacosaurus. The data here enable us to reconstruct the colors of Psittacosaurus as predominantly black and amber/brown, in cryptic patterns, somewhat dull, but useful to a prey animal. Indeed, skin pigment within a partially degraded bone indicates that Psittacosaurus was scavenged shortly after death. The theropod dinosaur Sinosauropteryx has recently been reported to have naturally pigmented

  7. Contributions of iridescence to floral patterning.

    Science.gov (United States)

    Whitney, Heather M; Kolle, Mathias; Alvarez-Fernandez, Ruben; Steiner, Ullrich; Glover, Beverley J

    2009-05-01

    The Hibiscus trionum flower is distinctly patterned, with white petals each with a patch of red pigment at the base, producing a 'bulls-eye' pattern on the whole flower. The red pigmented patches are also iridescent, due to the presence of a series of overlying cuticular striations that act as a diffraction grating. We have previously reported that scanning electron microscopy revealed a sharply defined difference between the surface structure overlying the pigmented patch and that over the rest of the petal, with the diffraction grating only present over the pigmented region. Here we show that differences in petal surface structure overlie differences in pigment color in three other species, in a range of different patterns. Floral patterns have previously been shown to be advantageous in pollinator attraction, and we discuss whether emphasis of pigment patterns by structural color may increase floral recognition by pollinators.

  8. NMDA-R inhibition affects cellular process formation in Tilapia melanocytes; a model for pigmented adrenergic neurons in process formation and retraction.

    Science.gov (United States)

    Ogundele, Olalekan Michael; Okunnuga, Adetokunbo Adedotun; Fabiyi, Temitope Deborah; Olajide, Olayemi Joseph; Akinrinade, Ibukun Dorcas; Adeniyi, Philip Adeyemi; Ojo, Abiodun Ayodele

    2014-06-01

    Parkinson's disease has long been described to be a product of dopamine and (or) melanin loss in the substanstia nigra (SN). Although most studies have focused on dopaminergic neurons, it is important to consider the role of pigment cells in the etiology of the disease and to create an in vitro live cell model for studies involving pigmented adrenergic cells of the SN in Parkinsonism. The Melanocytes share specific features with the pigmented adrenergic neurons as both cells are pigmented, contain adrenergic receptors and have cellular processes. Although the melanocyte cellular processes are relatively short and observable only when stimulated appropriately by epinephrine and other factors or molecules. This study employs the manipulation of N-Methyl-D-Aspartate Receptor (NMDA-R), a major receptor in neuronal development, in the process formation pattern of the melanocyte in order to create a suitable model to depict cellular process elongation and shortening in pigmented adrenergic cells. NMDA-R is an important glutamate receptor implicated in neurogenesis, neuronal migration, maturation and cell death, thus we investigated the role of NMDA-R potentiation by glutamate/KCN and its inhibition by ketamine in the behavior of fish scale melanocytes in vitro. This is aimed at establishing the regulatory role of NMDA-R in this cell type (melanocytes isolated form Tilapia) in a similar manner to what is observable in the mammalian neurons. In vitro live cell culture was prepared in modified Ringer's solution following which the cells were treated as follows; Control, Glutamate, Ketamine, Glutamate + Ketamine, KCN + Ketamine and KCN. The culture was maintained for 10 min and the changes were captured in 3D-Time frame at 0, 5 and 10 min for the control and 5, 7 and 10 min for each of the treatment category. Glutamate treatment caused formation of short cellular processes localized directly on the cell body while ketamine treatment (inhibition of NMDA-R) facilitated

  9. Epigenetic’s role in fish pigmentation

    Directory of Open Access Journals (Sweden)

    Laura Cal Delgado

    2014-04-01

    Full Text Available The agouti coat colour gene encodes a paracrine signalling molecule whose differential expression produces the characteristic dorsal-ventral pigment pattern observed in most mammals. We have recently demonstrated that this well-characterised mechanism from mammals also applies to fish with their much more complex pigment patterns. However, the developmental mechanism through which agouti acts to establish these colour differences remains unclear. The present study was undertaken to explore the molecular mechanisms that regulate agouti gene expression by in-vivo functional characterization of the agouti promoter and identification of possible putative regulatory elements that govern basal promoter activity. Specifically, the investigation was focused on the occurrence and role of CpG dinucleotides methylation in the agouti putative promoter sequence and on a possible epigenetic level of regulation of agouti expression. We report here expression analyses of eGFP expression from transgenic zebrafish containing an 8kb-agouti-Tol2-eGFP construct. eGFP expression was specifically found in the brain area and neural tube of Tol2 transposon vector transgenic embryos. Computer-based analysis revealed a putative CpG island immediately proximal to the translation start site. Global inhibition of methylation with 5-aza-2'-deoxycytidine promoted agouti production in association with decreasing CpG methylation. Taken together, these data identify a contributory role for DNA methylation in regulating agouti expression in zebrafish embryogenesis.

  10. Vaccinia virus-mediated melanin production allows MR and optoacoustic deep tissue imaging and laser-induced thermotherapy of cancer.

    Science.gov (United States)

    Stritzker, Jochen; Kirscher, Lorenz; Scadeng, Miriam; Deliolanis, Nikolaos C; Morscher, Stefan; Symvoulidis, Panagiotis; Schaefer, Karin; Zhang, Qian; Buckel, Lisa; Hess, Michael; Donat, Ulrike; Bradley, William G; Ntziachristos, Vasilis; Szalay, Aladar A

    2013-02-26

    We reported earlier the delivery of antiangiogenic single chain antibodies by using oncolytic vaccinia virus strains to enhance their therapeutic efficacy. Here, we provide evidence that gene-evoked production of melanin can be used as a therapeutic and diagnostic mediator, as exemplified by insertion of only one or two genes into the genome of an oncolytic vaccinia virus strain. We found that produced melanin is an excellent reporter for optical imaging without addition of substrate. Melanin production also facilitated deep tissue optoacoustic imaging as well as MRI. In addition, melanin was shown to be a suitable target for laser-induced thermotherapy and enhanced oncolytic viral therapy. In conclusion, melanin as a mediator for thermotherapy and reporter for different imaging modalities may soon become a versatile alternative to replace fluorescent proteins also in other biological systems. After ongoing extensive preclinical studies, melanin overproducing oncolytic virus strains might be used in clinical trials in patients with cancer.

  11. Response of pigmented porcine skin (Sus scrofa domestica) to single 3.8-micron laser radiation pulses

    Science.gov (United States)

    Bostick, Anthony C.; Johnson, Thomas E.; Randolph, Donald Q.; Winston, Golda C. H.

    2005-04-01

    Background and purpose: The purpose of this study is to determine the impact of melanin on skin response to single 3.8 micron, eight microsecond laser pulses and the difference in lesion formation thresholds for input into laser safety standards. Williams et al., performed a study examining laser tissue interaction from 3.8-micron lasers in lightly pigmented Yorkshire pigs (Sus scrofa domestica). However, studies performed by Eggleston et al comparing pigmented and lightly pigmented skin with human skin found that the Yucatan mini-pig is a superior model for laser skin exposures. Methods: Five Yucatan mini-pigs under general anesthesia were exposed to 3.8 micron laser pulses ranging from 0.8 J/cm2 to 93 J/cm2. Gross examinations were done acutely and 24 hours after laser exposure. Skin biopsies were then collected at various times post exposure, and histologic examinations were conducted. Results: The 24 hour ED50 was determined to be 4.5 J/cm2 with fiducial limits of 6.2 and 2.2 J/cm2. As deposited energy was increased, the lesion presentation ranged from whitening of the epidermis (4 J/cm2) to whitening with inflammatory centers (14 J/cm2), and at the highest energy levels inflammatory areas were replaced with an epidermal ulcerated central area (>21 J/cm2). Conclusion: Preliminary findings suggest pigmentation or melanin may play a minor role in the mechanism of laser-tissue damage. The ED50 of Yorkshire pigs was 2.6 J/cm2. The ED50 of the Yucatan mini-pig was found to be 3.6 J/cm2, and although it was higher, it is still within the 95% fiducial limits.

  12. Non-toxic melanin production inhibitors from Garcinia livingstonei (Clusiaceae).

    Science.gov (United States)

    Mulholland, Dulcie A; Mwangi, Elizabeth M; Dlova, Ncoza C; Plant, Nick; Crouch, Neil R; Coombes, Phillip H

    2013-09-16

    The stem bark of Garcinia livingstonei is used traditionally as a skin lightening agent. To isolate and identify compounds responsible for the observed skin lightening activity of Garcinia livingstonei and to evaluate their cytotoxicity. Constituents of the stem bark and fruits of Garcinia livingstonei were isolated using chromatographic techniques and structures were determined using 1D and 2D NMR and MS analysis. MeWo cells were used to evaluate the cytotoxicity and impact on melanin levels of extracts and compounds isolated, in vitro. Twelve known compounds, morelloflavone (1), morelloflavone-7″-sulphate (2), guttiferone A (3), sargaol (4), isojacareubin (5), 6-deoxyisojacareubin (6) and in addition to the common triterpenoids, betulin, betulin aldehyde, lupeol, lupenone, euphol and stigmasterol were isolated in this investigation. Morelloflavone, morelloflavone-7″-sulphate and sargaol, were found to be considerably less cytotoxic and more effective as skin lightening agents than hydroquinone. A range of compounds was isolated from the stem bark and fruit of Garcinia livingstonei. Although the bark extract contained the cytotoxic guttiferone A, it was found to be less toxic than hydroquinone, and morelloflavone, the 7″-sulphate derivative and sargaol show potential for development as depigmentation/skin lightening agents. © 2013 Elsevier Ireland Ltd. All rights reserved.

  13. Melanin-concentrating hormone (MCH: a new sleep factor?

    Directory of Open Access Journals (Sweden)

    Pablo eTorterolo

    2011-03-01

    Full Text Available Neurons that utilize the neuropeptide melanin-concentrating hormone (MCH as a neuromodulator are mainly located in the lateral hypothalamus and the incerto-hypothalamic area, and have widespread projections throughout the brain. While the biological functions of this neuropeptide are exerted in humans through two metabotropic receptors, the MCHR1 and MCHR2, only the MCHR1 is present in rodents. Recently, it has been shown that the MCHergic system is involved in the control of sleep. We can summarize the experimental findings as follows:1. The areas related to the control of sleep and wakefulness have an important density of MCHergic fibers and receptors.2. MCHergic neurons are active during sleep, especially during REM sleep.3. Genetically-modified animals without MCH have less REM sleep, notably under conditions of negative energy balance. 4. Systemically administered MCHR1 antagonists reduce sleep. 5. Intraventricular microinjection of MCH increases both slow wave sleep (SWS and REM sleep; however, the increment in REM sleep is more pronounced.6. Microinjection of MCH into the dorsal raphe nucleus increases REM sleep time. REM seep is inhibited by immunoneutralization of MCH within this nucleus.7. Microinjection of MCH in the nucleus pontis oralis of the cat enhances REM sleep time and reduces REM sleep latency.All these data strongly suggest that MCH has a potent role in the promotion of sleep. Although both SWS and REM sleep are facilitated by MCH, REM sleep seems to be more sensitive to MCH modulation.

  14. Streptomyces caeruleatus sp. nov., with dark blue diffusible pigment.

    Science.gov (United States)

    Zhu, Hong-hui; Guo, Jun; Yao, Qing; Yang, Song-zhen; Deng, Ming-rong; Li, Tai-hui

    2011-03-01

    An actinomycete, designated strain GIMN4.002(T), was isolated from a tomato rhizosphere soil sample in Guangzhou, China. The strain produces white aerial mycelium and dark blue diffusible pigment on Gause's synthetic agar, and microscopic observation revealed that it produces looped chains of spiny spores. Morphological and chemotaxonomic characteristics of the strain are typical of the genus Streptomyces. Melanin was produced and antibacterial activity was detected against Gram-positive micro-organisms, such as Bacillus subtilis, Micrococcus luteus and Staphylococcus aureus. The 16S rRNA gene sequence of strain GIMN4.002(T) had highest similarity (99.4  %) to Streptomyces lincolnensis B91; however, DNA-DNA relatedness between strain GIMN4.002(T) and S. lincolnensis NBRC 13054(T) was only 32.17  %. Further, the morphological, physiological and biochemical characteristics of strain GIMN4.002(T) are distinct from S. lincolnensis and other species of the genus Streptomyces with which this strain has high 16S rRNA gene sequence similarity (98-99  %). On the basis of the physiological and molecular properties observed, it is proposed that strain GIMN4.002(T) represents a novel species of the genus Streptomyces, for which the name Streptomyces caeruleatus sp. nov. is proposed, with GIMN4.002(T) (=CCTCC M 208213(T) =NRRL B-24802(T)) as the type strain.

  15. Primary Cilia Negatively Regulate Melanogenesis in Melanocytes and Pigmentation in a Human Skin Model

    Science.gov (United States)

    Kim, Eun Sung; Park, So Jung; Bae, Il-Hong; Jo, Yoon Kyung; Jeong, In Young; Kim, Hyoung-June; Lee, Youngjin; Park, Hea Chul; Jeon, Hong Bae; Kim, Ki Woo; Lee, Tae Ryong; Cho, Dong-Hyung

    2016-01-01

    The primary cilium is an organelle protruding from the cell body that senses external stimuli including chemical, mechanical, light, osmotic, fluid flow, and gravitational signals. Skin is always exposed to the external environment and responds to external stimuli. Therefore, it is possible that primary cilia have an important role in skin. Ciliogenesis was reported to be involved in developmental processes in skin, such as keratinocyte differentiation and hair formation. However, the relation between skin pigmentation and primary cilia is largely unknown. Here, we observed that increased melanogenesis in melanocytes treated with a melanogenic inducer was inhibited by a ciliogenesis inducer, cytochalasin D, and serum-free culture. However, these inhibitory effects disappeared in GLI2 knockdown cells. In addition, activation of sonic hedgehog (SHH)-smoothened (Smo) signaling pathway by a Smo agonist, SAG inhibited melanin synthesis in melanocytes and pigmentation in a human skin model. On the contrary, an inhibitor of primary cilium formation, ciliobrevin A1, activated melanogenesis in melanocytes. These results suggest that skin pigmentation may be regulated partly by the induction of ciliogenesis through Smo-GLI2 signaling. PMID:27941997

  16. Clinical studies of pigmented lesions in human skin by using a multiphoton tomograph

    Science.gov (United States)

    Balu, Mihaela; Kelly, Kristen M.; Zachary, Christopher B.; Harris, Ronald M.; Krasieva, Tatiana B.; König, Karsten; Tromberg, Bruce J.

    2013-02-01

    In vivo imaging of pigmented lesions in human skin was performed with a clinical multiphoton microscopy (MPM)-based tomograph (MPTflex, JenLab, Germany). Two-photon excited fluorescence was used for visualizing endogenous fluorophores such as NADH/FAD, keratin, melanin in the epidermal cells and elastin fibers in the dermis. Collagen fibers were imaged by second harmonic generation. Our study involved in vivo imaging of benign melanocytic nevi, atypical nevi and melanoma. The goal of this preliminary study was to identify in vivo the characteristic features and their frequency in pigmented lesions at different stages (benign, atypical and malignant) and to evaluate the ability of in vivo MPM to distinguish atypical nevi from melanoma. Comparison with histopathology was performed for the biopsied lesions. Benign melanocytic nevi were characterized by the presence of nevus cell nests at the epidermal-dermal junction. In atypical nevi, features such as lentiginous hyperplasia, acanthosis and architectural disorder were imaged. Cytological atypia was present in all the melanoma lesions imaged, showing the strongest correlation with malignancy. The MPM images demonstrated very good correlation with corresponding histological images, suggesting that MPM could be a promising tool for in vivo non-invasive pigmented lesion diagnosis, particularly distinguishing atypical nevi from melanoma.

  17. Skin pigmentation provides evidence of convergent melanism in extinct marine reptiles.

    Science.gov (United States)

    Lindgren, Johan; Sjövall, Peter; Carney, Ryan M; Uvdal, Per; Gren, Johan A; Dyke, Gareth; Schultz, Bo Pagh; Shawkey, Matthew D; Barnes, Kenneth R; Polcyn, Michael J

    2014-02-27

    Throughout the animal kingdom, adaptive colouration serves critical functions ranging from inconspicuous camouflage to ostentatious sexual display, and can provide important information about the environment and biology of a particular organism. The most ubiquitous and abundant pigment, melanin, also has a diverse range of non-visual roles, including thermoregulation in ectotherms. However, little is known about the functional evolution of this important biochrome through deep time, owing to our limited ability to unambiguously identify traces of it in the fossil record. Here we present direct chemical evidence of pigmentation in fossilized skin, from three distantly related marine reptiles: a leatherback turtle, a mosasaur and an ichthyosaur. We demonstrate that dark traces of soft tissue in these fossils are dominated by molecularly preserved eumelanin, in intimate association with fossilized melanosomes. In addition, we suggest that contrary to the countershading of many pelagic animals, at least some ichthyosaurs were uniformly dark-coloured in life. Our analyses expand current knowledge of pigmentation in fossil integument beyond that of feathers, allowing for the reconstruction of colour over much greater ranges of extinct taxa and anatomy. In turn, our results provide evidence of convergent melanism in three disparate lineages of secondarily aquatic tetrapods. Based on extant marine analogues, we propose that the benefits of thermoregulation and/or crypsis are likely to have contributed to this melanisation, with the former having implications for the ability of each group to exploit cold environments.

  18. Technical note: comparing von Luschan skin color tiles and modern spectrophotometry for measuring human skin pigmentation.

    Science.gov (United States)

    Swiatoniowski, Anna K; Quillen, Ellen E; Shriver, Mark D; Jablonski, Nina G

    2013-06-01

    Prior to the introduction of reflectance spectrophotometry into anthropological field research during the 1950s, human skin color was most commonly classified by visual skin color matching using the von Luschan tiles, a set of 36 standardized, opaque glass tiles arranged in a chromatic scale. Our goal was to establish a conversion formula between the tile-based color matching method and modern reflectance spectrophotometry to make historical and contemporary data comparable. Skin pigmentation measurements were taken on the forehead, inner upper arms, and backs of the hands using both the tiles and a spectrophotometer on 246 participants showing a broad range of skin pigmentation. From these data, a second-order polynomial conversion formula was derived by jackknife analysis to estimate melanin index (M-index) based on tile values. This conversion formula provides a means for comparing modern data to von Luschan tile measurements recorded in historical reports. This is particularly important for populations now extinct, extirpated, or admixed for which tile-based measures of skin pigmentation are the only data available.

  19. Vertebrate pigmentation: from underlying genes to adaptive function.

    Science.gov (United States)

    Hubbard, Joanna K; Uy, J Albert C; Hauber, Mark E; Hoekstra, Hopi E; Safran, Rebecca J

    2010-05-01

    Animal coloration is a powerful model for studying the genetic mechanisms that determine phenotype. Genetic crosses of laboratory mice have provided extensive information about the patterns of inheritance and pleiotropic effects of loci involved in pigmentation. Recently, the study of pigmentation genes and their functions has extended into wild populations, providing additional evidence that pigment gene function is largely conserved across disparate vertebrate taxa and can influence adaptive coloration, often in predictable ways. These new and integrative studies, along with those using a genetic approach to understand color perception, raise some important questions. Most notably, how does selection shape both phenotypic and genetic variation, and how can we use this information to further understand the phenotypic diversity generated by evolutionary processes? Copyright 2010 Elsevier Ltd. All rights reserved.

  20. Preparation of Thin Melanin-Type Films by Surface-Controlled Oxidation.

    Science.gov (United States)

    Salomäki, Mikko; Tupala, Matti; Parviainen, Timo; Leiro, Jarkko; Karonen, Maarit; Lukkari, Jukka

    2016-04-26

    The preparation of thin melanin films suitable for applications is challenging. In this work, we present a new alternative approach to thin melanin-type films using oxidative multilayers prepared by the sequential layer-by-layer deposition of cerium(IV) and inorganic polyphosphate. The interfacial reaction between cerium(IV) in the multilayer and 5,6-dihydroxyindole (DHI) in the adjacent aqueous solution leads to the formation of a thin uniform film. The oxidation of DHI by cerium(IV) proceeds via known melanin intermediates. We have characterized the formed DHI-melanin films using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), UV-vis spectroscopy, and spectroelectrochemistry. When a five-bilayer oxidative multilayer is used, the film is uniform with a thickness of ca. 10 nm. Its chemical composition, as determined using XPS, is typical for melanin. It is also redox active, and its oxidation occurs in two steps, which can be assigned to semiquinone and quinone formation within the indole structural motif. Oxidative multilayers can also oxidize dopamine, but the reaction stops at the dopamine quinone stage because of the limited amount of the multilayer-based oxidizing agent. However, dopamine oxidation by Ce(IV) was studied also in solution by UV-vis spectroscopy and mass spectrometry in order to verify the reaction mechanism and the final product. In solution, the oxidation of dopamine by cerium shows that the indole ring formation takes place already at low pH and that the mass spectrum of the final product is practically identical with that of commercial melanin. Therefore, layer-by-layer formed oxidative multilayers can be used to deposit functional melanin-type thin films on arbitrary substrates by a surface-controlled reaction.

  1. Genome-wide siRNA-based functional genomics of pigmentation identifies novel genes and pathways that impact melanogenesis in human cells.

    Directory of Open Access Journals (Sweden)

    Anand K Ganesan

    2008-12-01

    Full Text Available Melanin protects the skin and eyes from the harmful effects of UV irradiation, protects neural cells from toxic insults, and is required for sound conduction in the inner ear. Aberrant regulation of melanogenesis underlies skin disorders (melasma and vitiligo, neurologic disorders (Parkinson's disease, auditory disorders (Waardenburg's syndrome, and opthalmologic disorders (age related macular degeneration. Much of the core synthetic machinery driving melanin production has been identified; however, the spectrum of gene products participating in melanogenesis in different physiological niches is poorly understood. Functional genomics based on RNA-mediated interference (RNAi provides the opportunity to derive unbiased comprehensive collections of pharmaceutically tractable single gene targets supporting melanin production. In this study, we have combined a high-throughput, cell-based, one-well/one-gene screening platform with a genome-wide arrayed synthetic library of chemically synthesized, small interfering RNAs to identify novel biological pathways that govern melanin biogenesis in human melanocytes. Ninety-two novel genes that support pigment production were identified with a low false discovery rate. Secondary validation and preliminary mechanistic studies identified a large panel of targets that converge on tyrosinase expression and stability. Small molecule inhibition of a family of gene products in this class was sufficient to impair chronic tyrosinase expression in pigmented melanoma cells and UV-induced tyrosinase expression in primary melanocytes. Isolation of molecular machinery known to support autophagosome biosynthesis from this screen, together with in vitro and in vivo validation, exposed a close functional relationship between melanogenesis and autophagy. In summary, these studies illustrate the power of RNAi-based functional genomics to identify novel genes, pathways, and pharmacologic agents that impact a biological phenotype

  2. New blue pigment produced by Pantoea agglomerans and its production characteristics at various temperatures.

    Science.gov (United States)

    Fujikawa, Hiroshi; Akimoto, Ryo

    2011-01-01

    A bacterium capable of producing a deep blue pigment was isolated from the environment and identified as Pantoea agglomerans. The pigment production characteristics of the bacterium under various conditions were studied. The optimal agar plate ingredients for pigment production by the bacterium were first studied: the optimal ingredients were 5 g/liter glucose, 10 g/liter tryptic soy broth, and 40 g/liter glycerol at pH 6.4. Bacterial cells grew on the agar plate during the incubation, while the pigment spread into the agar plate, meaning that it is water soluble. Pigment production was affected by the initial cell density. Namely, at higher initial cell densities ranging from 10(6.3) to 10(8.2) CFU/cm(2) on the agar plate, faster pigment production was observed, but no blue pigment was produced at a very high initial density of 10(9.1) CFU/cm(2). Thus, the cell population of 10(8.2) CFU/cm(2) was used for subsequent study. Although the bacterium was capable of growing at temperatures above and below 10°C, it could produce the pigment only at temperatures of ≥10°C. Moreover, the pigment production was faster at higher temperatures in the range of 10 to 20°C. Pigment production at various temperature patterns was well described by a new logistic model. These results suggested that the bacterium could be used in the development of a microbial temperature indicator for the low-temperature-storage management of foods and clinical materials. To our knowledge, there is no other P. agglomerans strain capable of producing a blue pigment and the pigment is a new one of microbial origin.

  3. 产胞外黑色素海洋菌的鉴定及发酵条件优化%Identification and culture condition optimization for a marine extracellular melanin producing bacterium

    Institute of Scientific and Technical Information of China (English)

    田欣欣; 王琛; 曹为; 曲凌云

    2014-01-01

    从山东近海海域沉积物的微生物筛选中获得了一株高产胞外黑色素的菌株QJNY82,通过对该菌株菌落形态特征观察、生理生化检验及16S rDNA序列测定,初步确定该菌株为发光杆菌属细菌.通过对菌株QJNY82的胞外产物进行红外光谱分析,得到该细菌的胞外产物为黑色素,纯化后的黑色素的红外光谱图与标准黑色素(SIGMA)的红外光谱图一致,且该细菌所产黑色素的理化性质与标准黑色素具有一致性.该海洋菌株具有产黑色素速度快,产量高且不需要L-酪氨酸诱导的特点,而且经L-酪氨酸诱导后,可显著提高菌株QJNY82胞外黑色素的产量,在L-酪氨酸的含量为0.75 g/dm3、盐度为30、pH值为8.0、温度为28℃的条件下,菌株黑色素产量是未加L-酪氨酸的3.5倍,其产量达1.325 g/dm3.鉴于菌株QJNY82具有产黑色素的特性,将成为发光杆菌属的一个新的菌种资源.%One bacterial strain(QJNY82)that can produce melanin was isolated from a sample from Shandong coast-al sediment by our laboratory.Strain QJNY82 was identified as Photobacterium sp.based on morphological,physio-logical and biochemical tests as well as the 16S rDNA sequence analysis.We confirm the extracellular products of melanin through the infrared spectrum.The FT-IR spectra of its pigment is similar to that of the standard melanin (SIGMA).Moreover the physicochemical properties of melanin are similar to that of the standard melanin.Strain QJNY82 has advantages that it can produce melanin with a high yield in the absense of L-tyrosine.Induced by L-tyrosine,the melanin production could increases sharply.The results showed that the optimum condition was as fol-lows,i.e.L-tyrosine 0.75 g/dm3 ,pH=8.0,salinity 30,temperature 28℃.Its production reached 1.325 g/dm3 in the optimum condition.Strain QJNY82 may be identified as Photobacterium sp.,a new strain for melanin producing bacterium.

  4. A single gene (yes controls pigmentation of eyes and scales in Heliothis virescens

    Directory of Open Access Journals (Sweden)

    Thomas M. Brown

    2001-02-01

    Full Text Available A yellow-eyed mutant was discovered in a strain of Heliothis virescens, the tobacco budworm, that already exhibited a mutation for yellow scale, y. We investigated the inheritance of these visible mutations as candidate markers for transgenesis. Yellow eye was controlled by a single, recessive, autosomal factor, the same type of inheritance previously known for y. Presence of the recombinant mutants with yellow scales with wild type eyes in test crosses indicated independent segregation of genes for these traits. The recombinant class with wild type scales and yellow eyes was completely absent and there was a corresponding increase of the double mutant parental class having yellow scales and yellow eyes. These results indicated that a single factor for yellow eye also controls yellow scales independently of y. This gene was named yes, for yellow eye and scale. We hypothesize that yes controls both eye and scale color through a deficiency in transport of pigment precursors in both the ommochrome and melanin pathways. The unlinked gene y likely controls an enzyme affecting the melanin pathway only. Both y and yes segregated independently of AceIn, acetylcholinesterase insensitivity, and sodium channel hscp, which are genes related to insecticide resistance.

  5. Influence of Seven White Cream on Guinea Pigs Pigmentation Models Induced by Ultraviolet B%七白膏对中波紫外线诱导豚鼠色素沉着模型的影响研究

    Institute of Scientific and Technical Information of China (English)

    任金平; 王平; 王媚; 倪亚杰

    2013-01-01

    Objective To observe influence of seven white cream on guinea pigs pigmentation models induced by ultraviolet B (UVB). Methods NB-UVB induced pigmentation animal models. After establishing models, the areas of pigmentation were divided into four groups: traditional Chinese herb seven white cream group, 2% hydroquinone group, largehead atractylodes rhizome group and single matrix group, and then coated them on corresponding lesions. After treamtment for four weeks, the efficacy of the tested drug was evaluated comprehensively by such measures as melanin index, melanocyte, melanin as well as the histopathology of skin. Results It showed that the tested drug could greatly decrease the level of melanin index, restrain the activity of melanocyte, reduce the generation of melanin, and relieve pigmentation caused by UVB. Conclusion Seven white cream has obvious treatment function to NB-UVB-induced pigmentation, and it possible mechanisms are inhibiting the proliferation of melanocytes and decreasing melanin generation.%目的 探讨经方七白膏对中波紫外线(ultravioletB,UVB)诱导的色素沉着豚鼠模型的影响.方法 紫外线光疗仪诱导建立色素沉着豚鼠模型.建模成功后,将豚鼠背部色素沉着区域分为七白膏组、2%氢醌乳膏组、白术单体组和单基质乳膏组4个相离的区域,分别外涂药膏于相应的皮损区.外用药物治疗4周后,对各组皮肤进行黑色素指数、黑素颗粒、黑素细胞以及皮肤组织病理学检查观察药物的疗效和安全性.结果 外用七白膏可显著降低皮肤黑色素指数水平,抑制黑素细胞活性,减少黑素生成,缓解UVB所致的皮肤色素沉着.结论 经方七白膏对UVB诱导的豚鼠皮肤色素沉着有明显的改善作用,其可能的作用机制是在一定程度上抑制黑素细胞增殖,减少黑素的生物生成.

  6. Modification of Isolation and Culture of Human Retinal Pigment Epithelial Cells

    Institute of Scientific and Technical Information of China (English)

    ZhengJL; GuoY

    1999-01-01

    Purpose:To modify the isolation of human retinal pigment pithelial(RPE)cells and to increase the purification and production of cultured RPE cells.Methods:The human eyecups were fixed on a fubber holder.After digestion by trypsin,RPE cells were collected,then cultured and identified by morphology,immunohistochemistry and electron microscopy.Results:The cultured RPE cells grew actively in the early stage with transparent nucleus and abundant melanin particles in cytoplasm.These cells were positive in DOPA oxidase reaction and in anti-pancytokeratin antibody staining.Cellular microvilli and tight junctions could be seen through transmission electrom microscopy.Conclusion:We developed a rubber holder to fix the eyecup.Using this holder,more and purer cultured RPE cells can be obtained.These cultured REP cells are similar to those in vivo in morphology and immunohistochemical staining.

  7. Two-photon excited fluorescence lifetime imaging and spectroscopy of melanins in vitro and in vivo

    Science.gov (United States)

    Krasieva, Tatiana B.; Stringari, Chiara; Liu, Feng; Sun, Chung-Ho; Kong, Yu; Balu, Mihaela; Meyskens, Frank L.; Gratton, Enrico; Tromberg, Bruce J.

    2013-03-01

    Changes in the amounts of cellular eumelanin and pheomelanin have been associated with carcinogenesis. The goal of this work is to develop methods based on two-photon-excited-fluorescence (TPEF) for measuring relative concentrations of these compounds. We acquire TPEF emission spectra (λex=1000 nm) of melanin in vitro from melanoma cells, hair specimens, and in vivo from healthy volunteers. We find that the pheomelanin emission peaks at approximately 615 to 625 nm and eumelanin exhibits a broad maximum at 640 to 680 nm. Based on these data we define an optical melanin index (OMI) as the ratio of fluorescence intensities at 645 and 615 nm. The measured OMI for the MNT-1 melanoma cell line is 1.6±0.22 while the Mc1R gene knockdown lines MNT-46 and MNT-62 show substantially greater pheomelanin production (OMI=0.5±0.05 and 0.17±0.03, respectively). The measured values are in good agreement with chemistry-based melanin extraction methods. In order to better separate melanin fluorescence from other intrinsic fluorophores, we perform fluorescence lifetime imaging microscopy of in vitro specimens. The relative concentrations of keratin, eumelanin, and pheomelanin components are resolved using a phasor approach for analyzing lifetime data. Our results suggest that a noninvasive TPEF index based on spectra and lifetime could potentially be used for rapid melanin ratio characterization both in vitro and in vivo.

  8. Localization of melanin in conidia of Alternaria alternata using phage display antibodies.

    Science.gov (United States)

    Carzaniga, Raffaella; Fiocco, Daniela; Bowyer, Paul; O'Connell, Richard J

    2002-03-01

    Melanins derived from 1,8-dihydroxynaphthalene (DHN) are important for the pathogenicity and survival of fungi causing disease in both plants and animals. However, precise information on their location within fungal cell walls is lacking. To obtain antibodies for the immunocytochemical localization of melanin, 83 phage antibodies binding to 1,8-DHN were selected from a naive semisynthetic single-chain Fv (scFv) phage display library. Sequence analysis of the heavy chain binding domains of 17 antibodies showed a high frequency of positively charged amino acids. One antibody, designated M1, was characterized in detail. M1 bound specifically to 1,8-DHN in competitive inhibition enzyme-linked immunosorbent assays, showing no cross-reaction with nine structurally related phenolic compounds. Epitope recognition required two hydroxyl groups in a 1,8 configuration. M1 also bound to naturally occurring melanin isolated from mycelia of Alternaria alternata, suggesting that epitopes remain accessible in polymerized melanin. Transmission electron microscopy-immunogold labeling, using M1 in the form of soluble scFv fragments, showed that melanin was located in the septa and outer (primary) walls of wild-type A. alternata conidia, but not those of an albino mutant, AKT88-1. The M1 antibody provides a new tool for detecting melanized pathogens in plant and animal tissues and for precisely mapping the distribution of the polymer within spores, appressoria, and hyphae.

  9. Achieving better esthetics by gingival de-pigmentation: report of three cases with a review of the literature.

    Science.gov (United States)

    Parwani, Simran; Parwani, Rajkuman

    2013-02-01

    A smile expresses a feeling of joy and success and also reveals self-confidence and kindness in an individual. A holistic smile is dictated not only by the shape, position and color of the teeth but also by the health of the gingival tissues. Gingival appearance is an important component of an attractive smile. Melonin, carotene and hemoglobin are the most common natural pigments contributing to the normal color of gingiva. Although physiologic and ethnic melanin pigmentation is not a medical problem, complaints about "black gums" are common. For de-pigmentation of gingiva, different treatment modalities have been reported such as bur abrasion, scraping with scalpel, partial thickness flap, gingivectomy, cryotherapy, electrosurgery, lasers, free gingival autografting, sub-epithelial connective tissue graft and combination techniques. In the present case reports, scalpel surgery and electrosurgery were performed for gingival de-pigmentation, which are simple and effective. The esthetic results were pleasing and healing was uneventful. Patients were satisfied with the outcome at three month follow-up as evidenced from their feedback.

  10. Accuracy of pulse oximetry in pigmented patients

    African Journals Online (AJOL)

    Reflectance was measured at nine wavelengths. Results. The degree of pigmentation as measured by ... adversely affected by skin pigmentation, and it remains a ... the inner surface of the upper arm and the volar aspect of ..... Ph.D. mesis.

  11. Melanin-containing films: growth from dopamine solutions versus layer-by-layer deposition.

    Science.gov (United States)

    Bernsmann, Falk; Ersen, Ovidiu; Voegel, Jean-Claude; Jan, Edward; Kotov, Nicholas A; Ball, Vincent

    2010-10-25

    Films formed by oxidation of dopamine are of interest for functionalisation of solid-liquid interfaces owing to their versatility. However, the ability to modulate the properties of such films, for example, permeability to ionic species and the absorption coefficient, is urgently needed. Indeed, melanin films produced by oxidation of dopamine absorb strongly over the whole UV/Vis part of the electromagnetic spectrum and are impermeable to anions even for a film thickness as low as a few nanometers. Herein we combine oxidation of dopamine to produce a solution containing dopamine-melanin particles and their alternating deposition with poly(diallyldimethylammonium chloride) to produce films which have nearly the same morphology as pure dopamine-melanin films but are less compact, more transparent and more permeable to ferrocyanide anions.

  12. Analysis of the melanin distribution in different ethnic groups by in vivo laser scanning microscopy

    Science.gov (United States)

    Antoniou, C.; Lademann, J.; Richter, H.; Astner, S.; Patzelt, A.; Zastrow, L.; Sterry, W.; Koch, S.

    2009-05-01

    The aim of this study was to determine whether Laser scanning confocal microscopy (LSM) is able to visualize differences in melanin content and distribution in different Skin Phototypes. The investigations were carried out on six healthy volunteers with Skin Phototypes II, IV, and VI. Representative skin samples of Skin Phototypes II, V, and VI were obtained for histological analysis from remaining tissue of skin grafts and were used for LSM-pathologic correlation. LSM evaluation showed significant differences in melanin distribution in Skin Phototypes II, IV, and VI, respectively. Based on the differences in overall reflectivity and image brightness, a visual evaluation scheme showed increasing brightness of the basal and suprabasal layers with increasing Skin Phototypes. The findings correlated well with histological analysis. The results demonstrate that LSM may serve as a promising adjunctive tool for real time assessment of melanin content and distribution in human skin, with numerous clinical applications and therapeutic and preventive implications.

  13. Clofazimine-induced Hair Pigmentation

    Science.gov (United States)

    Philip, Mariam; Samson, Joan Felicita; Simi, Puthenveedu Salahudeen

    2012-01-01

    A 45-year-old man was treated with WHO multibacillary multidrug therapy for borderline leprosy and high dose daily Clofazimine for lepra reaction. Along with the expected side effect of skin pigmentation, the patient also noticed darkening of previously grey hair. This colour persisted eight months after completing multibacillary multidrug therapy. PMID:23180930

  14. Clofazimine-induced Hair Pigmentation.

    Science.gov (United States)

    Philip, Mariam; Samson, Joan Felicita; Simi, Puthenveedu Salahudeen

    2012-07-01

    A 45-year-old man was treated with WHO multibacillary multidrug therapy for borderline leprosy and high dose daily Clofazimine for lepra reaction. Along with the expected side effect of skin pigmentation, the patient also noticed darkening of previously grey hair. This colour persisted eight months after completing multibacillary multidrug therapy.

  15. Primary pigmented nodular adrenocortical disease

    Directory of Open Access Journals (Sweden)

    Marie T Manipadam

    2011-01-01

    Full Text Available Primary pigmented nodular adrenocortical disease (PPNAD is a rare cause of ACTH-independent Cushing′s syndrome and has characteristic gross and microscopic pathologic findings. We report a case of PPNAD in a 15-year-old boy, which was not associated with Carney′s complex. Bilateral adrenalectomy is the treatment of choice.

  16. Characterization of lapis lazuli and corresponding purified pigments for a provenance study of ultramarine pigments used in works of art.

    Science.gov (United States)

    Favaro, M; Guastoni, A; Marini, F; Bianchin, S; Gambirasi, A

    2012-02-01

    In this paper, we propose an analytical methodology for attributing provenance to natural lapis lazuli pigments employed in works of art, and for distinguishing whether they are of natural or synthetic origin. A multitechnique characterization of lazurite and accessory phases in lapis lazuli stones from Afghan, Siberian and Chilean quarries, on the pigments obtained by their purification, and on synthetic ultramarine pigments was performed. According to the results obtained, infrared spectroscopy is not a suitable technique for distinguishing the provenance of lapis lazuli, but a particular absorbance band makes it relatively easy to determine whether it is of natural or synthetic origin. On the other hand, EDS elemental composition and XRD patterns show the presence of specific mineral phases associated with specific lapis lazuli sources, and can be used to distinguish the provenance of the stones as well as-albeit to a lesser extent-the corresponding purified blue pigments. In contrast, FEG-SEM observations clearly show different stone textures depending on their provenance, although these distinctive features do not persist in the corresponding pigments. PCA analyses of EDS data allow Afghan lapis lazuli stone to be distinguished from Chilean and Siberian ones, and can distinguish between the pigments resulting from their purification as well as synthetic blue ones. Although this methodology was developed using a limited number of samples, it was tested on lapis lazuli pigments collected from three paintings (from the fourteenth to sixteenth centuries) in order to perform a preliminary validation of the technique, and based on the results, the provenance of the blue pigments employed in those artworks is proposed. Finally, upon analytically monitoring the process of purifying lapis lazuli to obtain the corresponding pigments, it was found that ion-exchange reactions occur between the alkali modifiers of silicate/aluminosilicate phases and free carboxylic acids

  17. Sexual selection and the function of a melanin-based plumage ornament in polygamous penduline tits Remiz pendulinus

    NARCIS (Netherlands)

    Kingma, Sjouke A.; Szentirmai, Istvan; Szekely, Tamas; Bokony, Veronika; Bleeker, Maarten; Liker, Andras; Komdeur, Jan; McGraw, K.

    2008-01-01

    Melanin-based ornaments are often involved in signaling aggression and dominance, and their role in sexual selection is increasingly recognized. We investigated the functions of a melanin-based plumage ornament (facial 'mask') in male Eurasian penduline tits Remiz pendulinus in the contexts of male-

  18. Sexual selection and the function of a melanin-based plumage ornament in polygamous penduline tits Remiz pendulinus

    NARCIS (Netherlands)

    Kingma, Sjouke A.; Szentirmai, Istvan; Szekely, Tamas; Bokony, Veronika; Bleeker, Maarten; Liker, Andras; Komdeur, Jan; McGraw, K.

    2008-01-01

    Melanin-based ornaments are often involved in signaling aggression and dominance, and their role in sexual selection is increasingly recognized. We investigated the functions of a melanin-based plumage ornament (facial 'mask') in male Eurasian penduline tits Remiz pendulinus in the contexts of male-

  19. Sexual Dichromatism of the Damselfly Calopteryx japonica Caused by a Melanin-Chitin Multilayer in the Male Wing Veins

    NARCIS (Netherlands)

    Stavenga, Doekele G.; Leertouwer, Hein L.; Hariyama, Takahiko; De Raedt, Hans A.; Wilts, Bodo D.

    2012-01-01

    Mature male Calopteryx japonica damselflies have dark-blue wings, due to darkly coloured wing membranes and blue reflecting veins. The membranes contain a high melanin concentration and the veins have a multilayer of melanin and chitin. Female and immature C. japonica damselflies have brown wings. W

  20. Melanin offers protection against induction of cyclobutane pyrimidine dimers and 6-4 photoproducts by UVB in cultured human melanocytes

    NARCIS (Netherlands)

    Smit, N.P.M.; Vink, A.A.; Kolb, R.M.; Steenwinkel, M.J.S.T.; Berg, P.T.M. van den; Nieuwpoort, F. van; Roza, L.; Pavel, S.

    2001-01-01

    The goal of this investigation was to correlate the melanin content in human pigmentary cells with the generation of UVB-induced photoproducts and to examine the relationship between the melanin content and the removal of the photoproducts. Cultured melanocytes from light-skinned individuals

  1. Sexual Dichromatism of the Damselfly Calopteryx japonica Caused by a Melanin-Chitin Multilayer in the Male Wing Veins

    NARCIS (Netherlands)

    Stavenga, Doekele G.; Leertouwer, Hein L.; Hariyama, Takahiko; De Raedt, Hans A.; Wilts, Bodo D.

    2012-01-01

    Mature male Calopteryx japonica damselflies have dark-blue wings, due to darkly coloured wing membranes and blue reflecting veins. The membranes contain a high melanin concentration and the veins have a multilayer of melanin and chitin. Female and immature C. japonica damselflies have brown wings.

  2. Flux pinning mechanism and H{sub c2}-anisotropy in melanin doped bulk MgB{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Shahabuddin Shah, M., E-mail: mshahabuddin@ksu.edu.sa; Shahabuddin, Mohammed; Alzayed, Nasser S.; Parakkandy, Jafar M.

    2014-06-15

    Highlights: • Melanin doping enhances superconducting properties of MgB{sub 2}. • Grain boundary pinning is the dominant pinning mechanism in melanin doped MgB{sub 2}. • Experimental J{sub c} data could be very closely fitted using Percolation model. • Anisotropy is reduced due to melanin doping resulting in increase in J{sub c} in high field. • Pinning force maximum is suppressed due to melanin doping. - Abstract: Flux pinning mechanism in melanin doped MgB{sub 2} superconductor has been studied using a scaling law proposed by Dew-Hughes and another method proposed by Eisterer. Our experimental data could be fitted very closely by the aforementioned scaling law. The fitting parameters, the positions of peaks b{sub peak} and k = b{sub peak}/b{sub n} confirm a grain-boundary pinning in the 10% melanin doped sample, while the undoped sample consists of mixed pinning. Furthermore, percolation theory was utilized under grain-boundary approximation to investigate the role of H{sub c2}-anisotropy in the critical current density, and its dependence on applied field as well as temperature. The H{sub c2}-anisotropy decreases with melanin doping resulting in the increase of J{sub c} in high field. There is suppression of flux pinning maximum due to melanin doping, which is found to be the main reason for the degradation of low-field J{sub c}.

  3. Melanin offers protection against induction of cyclobutane pyrimidine dimers and 6-4 photoproducts by UVB in cultured human melanocytes

    NARCIS (Netherlands)

    Smit, N.P.M.; Vink, A.A.; Kolb, R.M.; Steenwinkel, M.J.S.T.; Berg, P.T.M. van den; Nieuwpoort, F. van; Roza, L.; Pavel, S.

    2001-01-01

    The goal of this investigation was to correlate the melanin content in human pigmentary cells with the generation of UVB-induced photoproducts and to examine the relationship between the melanin content and the removal of the photoproducts. Cultured melanocytes from light-skinned individuals synthes

  4. Innovative use of Mucuna monosperma (Wight) callus cultures for continuous production of melanin by using statistically optimized biotransformation medium.

    Science.gov (United States)

    Inamdar, Shrirang; Joshi, Swati; Bapat, Vishwas; Jadhav, Jyoti

    2014-01-20

    Melanins are predominantly indolic polymers which are having extensive applications in cosmetics, agriculture and medicine. In the present study, optimization of nutritional parameters influencing melanin production by Mucuna monosperma callus cultures was attempted using the response surface methodology (RSM). Standardization of four factors was carried out using the Box-Behnken design. The optimized levels of factors predicted by the model include tyrosine 0.978gL(-1), pH 5.85, SDS 34.55mgL(-1)and copper sulphate 21.14mgL(-1) tyrosine, which resulted in highest melanin yield of 0.887gL(-1). The optimization of medium using RSM resulted in a 3.06-fold increase in the yield of melanin. The ANOVA analysis showed a significant R(2)-value (0.9995), model F-value (1917.72) and probability (0.0001), with insignificant lack of fit. Optimized medium was used in the laboratory scale column reactor for the continuous production of melanin. Uninterrupted flow column exhibited maximum melanin production rate of 250mgL(-1)h(-1) which is the highest value ever reported using plant as a biotransformation source. Melanin production was confirmed by spectrophotometric and chemical analysis. Thus, this study demonstrates the production of melanin by M. monosperma callus, using a laboratory scale column reactor.

  5. Pigmentation associated histopathological variations in sympathetic ophthalmia.

    Science.gov (United States)

    Marak, G E; Ikui, H

    1980-01-01

    The severity of inflammation in sympathetic ophthalmia is related to the degree of pigmentation, and the granulomatous response seems to be related to pigmentation. Eosinophilia is also associated with pigmentation, but this association appears to be fortuitous and is a result of the association of eosinophilia with severity of the inflammation. PMID:7387955

  6. 21 CFR 73.352 - Paracoccus pigment.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Paracoccus pigment. 73.352 Section 73.352 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.352 Paracoccus pigment. (a) Identity. (1) The color additive... mixtures for coloring foods. (b) Specifications. Paracoccus pigment shall conform to the...

  7. A case of pigmented Bowen's disease*

    Science.gov (United States)

    Vivan, Márcia Maria; Hirata, Sérgio Henrique; do Nascimento, Liliane Santos; Enokihara, Milvia Maria Simões e Silva

    2017-01-01

    Pigmented Bowen's disease is a rare subtype of Bowen's disease. Clinically it presents as a slow-growing, well-defined, hyperpigmented plaque, and should be included as a differential diagnosis of other pigmented lesions. The authors describe a challenging case of pigmented Bowen's disease with non-diagnostic dermscopy findings. PMID:28225972

  8. Condition-dependence, pleiotropy and the handicap principle of sexual selection in melanin-based colouration.

    Science.gov (United States)

    Roulin, Alexandre

    2016-05-01

    The signalling function of melanin-based colouration is debated. Sexual selection theory states that ornaments should be costly to produce, maintain, wear or display to signal quality honestly to potential mates or competitors. An increasing number of studies supports the hypothesis that the degree of melanism covaries with aspects of body condition (e.g. body mass or immunity), which has contributed to change the initial perception that melanin-based colour ornaments entail no costs. Indeed, the expression of many (but not all) melanin-based colour traits is weakly sensitive to the environment but strongly heritable suggesting that these colour traits are relatively cheap to produce and maintain, thus raising the question of how such colour traits could signal quality honestly. Here I review the production, maintenance and wearing/displaying costs that can generate a correlation between melanin-based colouration and body condition, and consider other evolutionary mechanisms that can also lead to covariation between colour and body condition. Because genes controlling melanic traits can affect numerous phenotypic traits, pleiotropy could also explain a linkage between body condition and colouration. Pleiotropy may result in differently coloured individuals signalling different aspects of quality that are maintained by frequency-dependent selection or local adaptation. Colouration may therefore not signal absolute quality to potential mates or competitors (e.g. dark males may not achieve a higher fitness than pale males); otherwise genetic variation would be rapidly depleted by directional selection. As a consequence, selection on heritable melanin-based colouration may not always be directional, but mate choice may be conditional to environmental conditions (i.e. context-dependent sexual selection). Despite the interest of evolutionary biologists in the adaptive value of melanin-based colouration, its actual role in sexual selection is still poorly understood.

  9. Comparison of Surgical Blade and Cryosurgery with Liquid Nitrogen Techniques in Treatment of Physiologic Gingival Pigmentation: Short Term Results

    Directory of Open Access Journals (Sweden)

    Saeed Rahmati

    2014-12-01

    Full Text Available Statement of the Problem: Melanin pigmentation of the gingiva is a crucial esthetic problem. A variety of methods have been used for gingival depigmentation. Purpose: The purpose of this study was to compare the results of two treatment modalities: scalpel technique and cryotherapy with liquid nitrogen in treatment of gingival pigmentation. Materials and Method: Twenty patients with chief complaint of gingival pigmentation participated in our study. 10 patients were treated with cryotherapy and remaining 10 participants were undergone the scalpel technique surgery. We evaluated acquiescence and comfort of the patients, degree of depigmentation, based on the area of pigmentation shown by gridlines option in Microsoft Paint software, and the presence or absence of gingival recession before and one month after treatment. Data was analyzed using Mann-Whitney and Chi-Square tests. A significance level of p≤ 0.05 was adopted. Results: Mean value and standard deviation of depigmentation for group A and group B was 96.17±2.51 and 95±2.48, respectively. The difference was not statistically significant (p= 0.225. There was no association between the treatment modality and the gingival recession (p= 0.303 or the treatment modality and the patient satisfaction (p= 0.346. No significant difference was found between gingival recession measures before and after the operation in the two treatment modalities. Conclusion: Surgical blade and cryosurgery with liquid nitrogen had no significant difference in treatment of physiologic gingival pigmentation. Both Techniques are acceptable in the treatment of gingival pigmentation.

  10. Tyrosine and the synthesis of melanin in embryonic cells fromAmbystoma mexicanum.

    Science.gov (United States)

    Landström, Ulf; Løvtrup, Søren

    1978-09-01

    Explants comprising about 15 cells were dissected from various regions of the blastula ofAmbystoma mexicanum and cultured in Barth's medium. By addition of L-tyrosine to the culture medium it was possible to induce melanin synthesis in three different cells types: undifferentiated embryonic cells, mesenchyme cells and nerve cells. Tyrosine was found to act as an inductor in a very low concentration (1 μM). It is suggested that tyrosine serves both as an inductor and as a substrate for melanin synthesis in the amphibian larva.

  11. Prevention of melanin formation during aryl alcohol oxidase production under growth-limited conditions using an Aspergillus nidulans cell factory.

    Science.gov (United States)

    Pardo-Planas, Oscar; Prade, Rolf A; Müller, Michael; Atiyeh, Hasan K; Wilkins, Mark R

    2017-11-01

    An Aspergillus nidulans cell factory was genetically engineered to produce an aryl alcohol oxidase (AAO). The cell factory initiated production of melanin when growth-limited conditions were established using stationary plates and shaken flasks. This phenomenon was more pronounced when the strain was cultured in a trickle bed reactor (TBR). This study investigated different approaches to reduce melanin formation in fungal mycelia and liquid medium in order to increase the enzyme production yield. Removal of copper from the medium recipe reduced melanin formation in agar cultures and increased enzyme activities by 48% in agitated liquid cultures. Copper has been reported as a key element for tyrosinase, an enzyme responsible for melanin production. Ascorbic acid (0.44g/L) stopped melanin accumulation, did not affect growth parameters and resulted in AAO activity that was more than two-fold greater than a control treatment with no ascorbic acid. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Sulfate as a pivotal factor in regulation of Serratia sp. strain S2B pigment biosynthesis.

    Science.gov (United States)

    Rastegari, Banafsheh; Karbalaei-Heidari, Hamid Reza

    2016-10-01

    In the present work, we investigated the prodiginine family as secondary metabolite members. Bacterial strain S2B, with the ability to produce red pigment, was isolated from the Sarcheshmeh copper mine in Iran. 16S rDNA gene sequencing revealed that the strain was placed in the Serratia genus. Pigment production was optimized using low-cost culture medium and the effects of various physicochemical factors were studied via statistical approaches. Purification of the produced pigment by silica gel column chromatography showed a strong red pigment fraction and a weaker orange band. Mass spectrometry, FT-IR spectroscopy and (1)H NMR analysis revealed that the red pigment was prodigiosin and the orange band was a prodigiosin-like analog, with molecular weights of 323 and 317 Da, respectively. Genotoxicity and cytotoxicity studies confirmed their membership in the prodiginine family. Analysis of the production pattern of the pigments in the presence of different concentrations of ammonium salts revealed the role of sulfate as an important factor in regulation of the pigment biosynthesis pathway. Overall, the data showed that regulation of the pigment biosynthesis pathway in Serratia sp. strain S2B was affected by inorganic micronutrients, particularly the sulfate ions.

  13. Protection of melanized Cryptococcus neoformans from lethal dose gamma irradiation involves changes in melanin's chemical structure and paramagnetism.

    Directory of Open Access Journals (Sweden)

    Abdelahad Khajo

    Full Text Available Certain fungi thrive in highly radioactive environments including the defunct Chernobyl nuclear reactor. Cryptococcus neoformans (C. neoformans, which uses L-3,4-dihydroxyphenylalanine (L-DOPA to produce melanin, was used here to investigate how gamma radiation under aqueous aerobic conditions affects the properties of melanin, with the aim of gaining insight into its radioprotective role. Exposure of melanized fungal cell in aqueous suspensions to doses of γ-radiation capable of killing 50 to 80% of the cells did not lead to a detectable loss of melanin integrity according to EPR spectra of melanin radicals. Moreover, upon UV-visible (Xe-lamp illumination of melanized cells, the increase in radical population was unchanged after γ-irradiation. Gamma-irradiation of frozen cell suspensions and storage of samples for several days at 77 K however, produced melanin modification noted by a reduced radical population and reduced photoresponse. More direct evidence for structural modification of melanin came from the detection of soluble products with absorbance maxima near 260 nm in supernatants collected after γ-irradiation of cells and cell-free melanin. These products, which include thiobarbituric acid (TBA-reactive aldehydes, were also generated by Fenton reagent treatment of cells and cell-free melanin. In an assay of melanin integrity based on the metal (Bi(+3 binding capacity of cells, no detectable loss in binding was detected after γ-irradiation. Our results show that melanin in C. neoformans cells is susceptible to some damage by hydroxyl radical formed in lethal radioactive aqueous environments and serves a protective role in melanized fungi that involves sacrificial breakdown.

  14. Hybrid pigment organelles in an invertebrate.

    Science.gov (United States)

    Schliwa, M; Euteneuer, U

    1979-02-28

    Observations of a number of vertebrate chromatophores have revealed the presence of more than one type of pigment organelles, suggesting that the different types are all derived from an equipotential organelle able to differentiate into any of the major pigment-containing organelles (Bagnara, 1972). Observations are presented concerning the occurrence of hybrid pigment inclusions, i.e., all kinds of intergrades between melanosomes, pterinosomes, and reflecting platelets in pigment cells of the daddy-long-legs. It therefore seems possible that pigment organelles in some invertebrates may also be derived from a common pluripotential primordial organelle.

  15. Research Progress of Microorganisms Pigments in the Food Industry%食品工业中微生物色素的研究进展

    Institute of Scientific and Technical Information of China (English)

    杨双春; 李春雨; 潘一

    2014-01-01

    Natural pigment is extracted from the animals and plants organization and microorganism cultivation. It has many characteristics such as natural bright colour and luster, high nutritional value, avirulent, harmless and high safety. It is a good method that natural pigment was produced by microorganism to solve the problems of raw material scarce and high costs. By the way , this way also could increase yield of natural pigment. In this paper, the microorganism pigment, monascus pigment, gardenia pigment, carotenoids, melanin, indigo were introduced and summarized. Characteristics of microorganism pigment were reviewed including breeding strains , extraction method, and recommendations on a variety of the microbial pigment in the industrial production.%天然色素是指从动物和植物组织及微生物(培养)中提取的色素,具有色泽自然鲜艳,营养价值高,无毒无害、安全性高的特点。利用微生物生产天然色素可以解决天然色素原料稀少、成本高昂等诸多问题,更有利于工业化生产。本文介绍的微生物色素,有红曲色素、栀子色素、类胡萝卜素、黑色素、靛蓝等,对其特性、菌种选育、提取方法等进行了综述,并对各种微生物色素如何进行工业化生产提出了建议。

  16. Artificial neural network model for photosynthetic pigments identification using multi wavelength chromatographic data

    Science.gov (United States)

    Prilianti, K. R.; Hariyanto, S.; Natali, F. D. D.; Indriatmoko, Adhiwibawa, M. A. S.; Limantara, L.; Brotosudarmo, T. H. P.

    2016-04-01

    The development of rapid and automatic pigment characterization method become an important issue due to the fact that there are only less than 1% of plant pigments in the earth have been explored. In this research, a mathematical model based on artificial intelligence approach was developed to simplify and accelerate pigment characterization process from HPLC (high-performance liquid chromatography) procedure. HPLC is a widely used technique to separate and identify pigments in a mixture. Input of the model is chromatographic data from HPLC device and output of the model is a list of pigments which is the spectrum pattern is discovered in it. This model provides two dimensional (retention time and wavelength) fingerprints for pigment characterization which is proven to be more accurate than one dimensional fingerprint (fixed wavelength). Moreover, by mimicking interconnection of the neuron in the nervous systems of the human brain, the model have learning ability that could be replacing expert judgement on evaluating spectrum pattern. In the preprocessing step, principal component analysis (PCA) was used to reduce the huge dimension of the chromatographic data. The aim of this step is to simplify the model and accelerate the identification process. Six photosynthetic pigments i.e. zeaxantin, pheophytin a, α-carotene, β-carotene, lycopene and lutein could be well identified by the model with accuracy up to 85.33% and processing time less than 1 second.

  17. Influence of melanocytes in the ex-vivo reconstructed epidermal melanin unit following an acute UV irradiation; Role des melanocytes dans l'unite epidermique de melanisation reconstruite ex-vivo apres une irradiation UV aigue

    Energy Technology Data Exchange (ETDEWEB)

    Cario-Andre, M

    2000-11-15

    Influence of melanocytes in skin pigmentation is well documented, however its photo-protective role has given rise to controversy. The role of melanocytes have been investigated on reconstructed epidermis with 100 % of keratinocytes or 95 % of keratinocytes and 5 % of melanocytes. In a first time, the effect of an acute UVB dose has been studied on both reconstructed epidermis, next we have investigated UVA and UVA+B effects on these epidermis. Following irradiation, the presence of melanocytes in reconstructed epidermis protects against apoptosis without protecting significantly against DNA damage formation (CPD, 6-4PP) and protects against UV-induced unbalance of the SOD/catalase ratio (antioxidants enzymes). On the contrary, the presence of melanocytes in reconstructed epidermis amplifies lipids and proteins oxidations but seems to protect against DNA oxidations. Melanocytes differ from keratinocytes by their melanin content and their more important concentration in polyunsaturated fatty acids. To evaluate what is the part of melanin and the part of polyunsaturated fatty acids in epidermal UV responses, reconstructed epidermis with keratinocytes have been supplemented with polyunsaturated fatty acid. This study indicates that polyunsaturated fatty acids are responsible for lipids and proteins oxidations and that melanin protect against DNA oxidation induced by lipid peroxidation. All these studies demonstrate that, model of reconstructed epidermis and epidermis in-vivo have the same behaviour following UV irradiation. In the last part, sunscreens and antioxidants have been tested on reconstructed epidermis and have demonstrated that model of reconstructed epidermis is suitable for photo-protective molecules screening. (author)

  18. Identification and hazard prediction of tattoo pigments by means of pyrolysis-gas chromatography/mass spectrometry.

    Science.gov (United States)

    Schreiver, Ines; Hutzler, Christoph; Andree, Sarah; Laux, Peter; Luch, Andreas

    2016-07-01

    The implementation of regulation for tattoo ink ingredients across Europe has generated the need for analytical methods suitable to identify prohibited compounds. Common challenges of this subject are the poor solubility and the lack of volatility for most pigments and polymers applied in tattoo inks. Here, we present pyrolysis coupled to online gas chromatography and electron impact ionization mass spectrometry (py-GC/MS) as quick and reliable tool for pigment identification using both purified pigments and tattoo ink formulations. Some 36 organic pigments frequently used in tattoo inks were subjected to py-GC/MS with the aim to establish a pyrogram library. To cross-validate pigment identification, 28 commercially available tattoo inks as well as 18 self-made pigment mixtures were analyzed. Pyrograms of inks and mixtures were evaluated by two different means to work out the most reliable and fastest strategy for an otherwise rather time-consuming data review. Using this approach, the declaration of tattoo pigments currently used on the market could be verified. The pyrolysis library presented here is also assumed suitable to predict decomposition patterns of pigments when affected by other degradation scenarios, such as sunlight exposure or laser irradiation. Thus, the consumers' risk associated with the exposure to toxicologically relevant substances that originate from pigment decomposition in the dermal layers of the skin can be assessed. Differentiation between more or less harmful pigments for this field of application now will become feasible.

  19. Availability and Utilization of Pigments from Microalgae.

    Science.gov (United States)

    Begum, Hasina; Yusoff, Fatimah Md; Banerjee, Sanjoy; Khatoon, Helena; Shariff, Mohamed

    2016-10-02

    Microalgae are the major photosynthesizers on earth and produce important pigments that include chlorophyll a, b and c, β-carotene, astaxanthin, xanthophylls, and phycobiliproteins. Presently, synthetic colorants are used in food, cosmetic, nutraceutical, and pharmaceutical industries. However, due to problems associated with the harmful effects of synthetic colorants, exploitation of microalgal pigments as a source of natural colors becomes an attractive option. There are various factors such as nutrient availability, salinity, pH, temperature, light wavelength, and light intensity that affect pigment production in microalgae. This paper reviews the availability and characteristics of microalgal pigments, factors affecting pigment production, and the application of pigments produced from microalgae. The potential of microalgal pigments as a source of natural colors is enormous as an alternative to synthetic coloring agents, which has limited applications due to regulatory practice for health reasons.

  20. Skin pigmentation kinetics after UVB exposure

    DEFF Research Database (Denmark)

    Ravnbak, M.H.; Philipsen, P.A.; Wiegell, S.R.

    2008-01-01

    There have been few previous studies of the kinetics of pigmentation following ultraviolet B (UVB) exposure, and these have included only fair-skinned persons. The current study investigated pigmentation increase to steady state and fading in 12 Scandinavians and 12 Indians/Pakistanis. Over...... a period of 3 weeks the subjects were UV-irradiated 6 times on the right side of the back and 12 times on the left side using a Solar Simulator and narrowband UVB with equal sub-Minimal Melanogenesis Doses (individually predetermined). Pigmentation was measured from skin remittance at 555 urn and 660 nm...... (allowing correction for erythema). The absolute pigmentation increase was independent of pre-exposure pigmentation, therefore the percentage pigmentation increase was higher in fair-skinned volunteers. The UV dose to minimal pigmentation was higher in darker-skinned persons for single and multiple UV...

  1. Experimental and theoretical studies of perceptible color fading of decorative paints consisting of mixed pigments

    Science.gov (United States)

    Auger, Jean-Claude; McLoughlin, Daragh

    2017-01-01

    We study the color fading of paints films composed of mixtures of white rutile titanium dioxide and yellow arylide pigments dispersed in two polymer binders at different volume concentrations. The samples were exposed to ultraviolet radiations in an accelerated weathering tester during three weeks. The measured patterns in color variations appeared to be independent of the chemistry of the binders. We then developed a theoretical framework, based on the Radiative transfer Equation of light and the One Particle T-Matrix formalism to simulate the color fading process. The loss of color is correlated to the progressive decrease of the original colored pigment volume-filling fraction as the destructive UV radiations penetrate deeper into the films. The calculated patterns of color variations of paints film composed by mixtures of white pigments with yellow Cadmium Sulfate (CdS) and red Cerium Sulfide (Ce2S3) pigments showed the same trend as that seen experimentally.

  2. Holographic films from carotenoid pigments

    Science.gov (United States)

    Toxqui-López, S.; Lecona-Sánchez, J. F.; Santacruz-Vázquez, C.; Olivares-Pérez, A.; Fuentes-Tapia, I.

    2014-02-01

    Carotenoids pigments presents in pineapple can be more than just natural dyes, which is one of the applications that now at day gives the chemical industry. In this research shown that can be used in implementing of holographic recording Films. Therefore we describe the technique how to obtain this kind of pigments trough spay drying of natural pineapple juice, which are then dissolved with water in a proportion of 0.1g to 1mL. The obtained sample is poured into glass substrates using the gravity method, after a drying of 24 hours in laboratory normal conditions the films are ready. The films are characterized by recording transmission holographic gratings (LSR 445 NL 445 nm) and measuring the diffraction efficiency holographic parameter. This recording material has good diffraction efficiency and environmental stability.

  3. Pigmented villonodular synovitis: MRI characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, T.H. [Dept. of Radiology, Univ. of California, San Diego, CA (United States)]|[Veterans Administration Medical Center, San Diego, CA (United States); Sartoris, D.J. [Dept. of Radiology, Univ. of California, San Diego, CA (United States)]|[Veterans Administration Medical Center, San Diego, CA (United States); Schweitzer, M.E. [Dept. of Radiology, Thomas Jefferson Univ. Hospital, Philadelphia, PA (United States); Resnick, D.L. [Dept. of Radiology, Univ. of California, San Diego, CA (United States)]|[Veterans Administration Medical Center, San Diego, CA (United States)

    1995-01-01

    The magnetic resonance imaging (MRI) scans of 26 patients with histopathologically proven pigmented villonodular synovitis (PVNS), involving joints but excluding tendon sheaths, were reviewed retrospectively. The purpose of this study is to define the spectrum and frequency of MRI characteristics for PVNS using conventional spin echo (in two cases before and after intravenous administration of gadopentate dimeglumine) and also gradient echo techniques. A cystic variety is presented, the MRI appearances of which have not been found in a review of the literature. (orig.)

  4. Nanoscience of an ancient pigment.

    Science.gov (United States)

    Johnson-McDaniel, Darrah; Barrett, Christopher A; Sharafi, Asma; Salguero, Tina T

    2013-02-06

    We describe monolayer nanosheets of calcium copper tetrasilicate, CaCuSi(4)O(10), which have strong near-IR luminescence and are amenable to solution processing methods. The facile exfoliation of bulk CaCuSi(4)O(10) into nanosheets is especially surprising in view of the long history of this material as the colored component of Egyptian blue, a well-known pigment from ancient times.

  5. Inhibitory Effect of Arctigenin from Fructus Arctii Extract on Melanin Synthesis via Repression of Tyrosinase Expression.

    Science.gov (United States)

    Park, Hwayong; Song, Kwang Hoon; Jung, Pil Mun; Kim, Ji-Eun; Ro, Hyunju; Kim, Mi Yoon; Ma, Jin Yeul

    2013-01-01

    To identify the active compound arctigenin in Fructus Arctii (dried seed of medicinal plant Arctium lappa) and to elucidate the inhibitory mechanism in melanogenesis, we analyzed melanin content and tyrosinase activity on B16BL6 murine melanoma and melan-A cell cultures. Water extracts of Fructus Arctii were shown to inhibit tyrosinase activity in vitro and melanin content in α -melanocyte stimulating hormone-stimulated cells to similar levels as the well-known kojic acid and arbutin, respectively. The active compound arctigenin of Fructus Arctii displayed little or no cytotoxicity at all concentrations examined and decreased the relative melanin content and tyrosinase activity in a dose-dependent manner. Melanogenic inhibitory activity was also identified in vivo with zebrafish embryo. To determine the mechanism of inhibition, the effects of arctigenin on tyrosinase gene expression and tyrosinase promoter activity were examined. Also in addition, in the signaling cascade, arctigenin dose dependently decreased the cAMP level and promoted the phosphorylation of extracellular signal-regulated kinase. This result suggests that arctigenin downregulates cAMP and the tyrosinase enzyme through its gene promoter and subsequently upregulates extracellular signal-regulated kinase activity by increasing phosphorylation in the melanogenesis signaling pathway, which leads to a lower melanin content.

  6. Melanin-based color of plumage: role of condition and of feathers' microstructure

    Science.gov (United States)

    D'Alba, Liliana; Van Hemert, Caroline R.; Spencer, Karen A.; Heidinger, Britt J.; Gill, Lisa; Evans, Neil P.; Monaghan, Pat; Handel, Colleen M.; Shawkey, Matthew D.

    2014-01-01

    Whether melanin-based colors honestly signal a bird's condition during the growth of feathers is controversial, and it is unclear if or how the physiological processes underlying melanogenesis or color-imparting structural feather microstructure may be adversely affected by condition. Here we report results from two experiments designed to measure the effect of condition on expression of eumelanic and pheomelanic coloration in black-capped chickadees (Poecile atricapillus) and zebra finches (Taeniopygia guttata), respectively. In chickadees, we compared feathers of birds affected and unaffected by avian keratin disorder, while in zebra finches we compared feathers of controls with feathers of those subjected to an unpredictable food supply during development. In both cases we found that control birds had brighter feathers (higher total reflectance) and more barbules, but similar densities of melanosomes. In addition, the microstructure of the feathers explained variation in color more strongly than did melanosome density. Together, these results suggest that melanin-based coloration may in part be condition-dependent, but that this may be driven by changes in keratin and feather development, rather than melanogenesis itself. Researchers should be cautious when assigning variation in melanin-based color to melanin alone and microstructure of the feather should be taken into account.

  7. Mechanistic insights into the bleaching of melanin by alkaline hydrogen peroxide.

    Science.gov (United States)

    Smith, R A W; Garrett, B; Naqvi, K R; Fülöp, A; Godfrey, S P; Marsh, J M; Chechik, V

    2017-07-01

    This work aims to determine the roles of reactive oxygen species HO∙ and HO2(-) in the bleaching of melanins by alkaline hydrogen peroxide. Experiments using melanosomes isolated from human hair indicated that the HO∙ radical generated in the outside solution does not contribute significantly to bleaching. However, studies using soluble Sepia melanin demonstrated that both HO2(-) and HO∙ will individually bleach melanin. Additionally, when both oxidants are present, bleaching is increased dramatically in both rate and extent. Careful experimental design enabled the separation of the roles and effects of these key reactive species, HO∙ and HO2(-). Rationalisation of the results presented, and review of previous literature, allowed the postulation of a simplified general scheme whereby the strong oxidant HO∙ is able to pre-oxidise melanin units to o-quinones enabling more facile ring opening by the more nucleophilic HO2(-). In this manner the efficiency of the roles of both species is maximised. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Melanin-independent accumulation of turgor pressure in appressoria of Phakopsora pachyrhizi

    Science.gov (United States)

    In some plant pathogenic fungi, turgor pressure accumulation in appressoria produces a mechanical force enabling the direct penetration of hyphae through the plant cell epidermis. Melanin has been reported to function as an impermeable barrier to osmolytes, which allow appressoria to accumulate high...

  9. Inhibitory Effect of Arctigenin from Fructus Arctii Extract on Melanin Synthesis via Repression of Tyrosinase Expression

    Science.gov (United States)

    Park, Hwayong; Song, Kwang Hoon; Jung, Pil Mun; Kim, Ji-Eun; Kim, Mi Yoon; Ma, Jin Yeul

    2013-01-01

    To identify the active compound arctigenin in Fructus Arctii (dried seed of medicinal plant Arctium lappa) and to elucidate the inhibitory mechanism in melanogenesis, we analyzed melanin content and tyrosinase activity on B16BL6 murine melanoma and melan-A cell cultures. Water extracts of Fructus Arctii were shown to inhibit tyrosinase activity in vitro and melanin content in α-melanocyte stimulating hormone-stimulated cells to similar levels as the well-known kojic acid and arbutin, respectively. The active compound arctigenin of Fructus Arctii displayed little or no cytotoxicity at all concentrations examined and decreased the relative melanin content and tyrosinase activity in a dose-dependent manner. Melanogenic inhibitory activity was also identified in vivo with zebrafish embryo. To determine the mechanism of inhibition, the effects of arctigenin on tyrosinase gene expression and tyrosinase promoter activity were examined. Also in addition, in the signaling cascade, arctigenin dose dependently decreased the cAMP level and promoted the phosphorylation of extracellular signal-regulated kinase. This result suggests that arctigenin downregulates cAMP and the tyrosinase enzyme through its gene promoter and subsequently upregulates extracellular signal-regulated kinase activity by increasing phosphorylation in the melanogenesis signaling pathway, which leads to a lower melanin content. PMID:23781272

  10. Inhibitory Effect of Arctigenin from Fructus Arctii Extract on Melanin Synthesis via Repression of Tyrosinase Expression

    Directory of Open Access Journals (Sweden)

    Hwayong Park

    2013-01-01

    Full Text Available To identify the active compound arctigenin in Fructus Arctii (dried seed of medicinal plant Arctium lappa and to elucidate the inhibitory mechanism in melanogenesis, we analyzed melanin content and tyrosinase activity on B16BL6 murine melanoma and melan-A cell cultures. Water extracts of Fructus Arctii were shown to inhibit tyrosinase activity in vitro and melanin content in α-melanocyte stimulating hormone-stimulated cells to similar levels as the well-known kojic acid and arbutin, respectively. The active compound arctigenin of Fructus Arctii displayed little or no cytotoxicity at all concentrations examined and decreased the relative melanin content and tyrosinase activity in a dose-dependent manner. Melanogenic inhibitory activity was also identified in vivo with zebrafish embryo. To determine the mechanism of inhibition, the effects of arctigenin on tyrosinase gene expression and tyrosinase promoter activity were examined. Also in addition, in the signaling cascade, arctigenin dose dependently decreased the cAMP level and promoted the phosphorylation of extracellular signal-regulated kinase. This result suggests that arctigenin downregulates cAMP and the tyrosinase enzyme through its gene promoter and subsequently upregulates extracellular signal-regulated kinase activity by increasing phosphorylation in the melanogenesis signaling pathway, which leads to a lower melanin content.

  11. Surface structure characterization of Aspergillus fumigatus conidia mutated in the melanin synthesis pathway and their human cellular immune response.

    Science.gov (United States)

    Bayry, Jagadeesh; Beaussart, Audrey; Dufrêne, Yves F; Sharma, Meenu; Bansal, Kushagra; Kniemeyer, Olaf; Aimanianda, Vishukumar; Brakhage, Axel A; Kaveri, Srini V; Kwon-Chung, Kyung J; Latgé, Jean-Paul; Beauvais, Anne

    2014-08-01

    In Aspergillus fumigatus, the conidial surface contains dihydroxynaphthalene (DHN)-melanin. Six-clustered gene products have been identified that mediate sequential catalysis of DHN-melanin biosynthesis. Melanin thus produced is known to be a virulence factor, protecting the fungus from the host defense mechanisms. In the present study, individual deletion of the genes involved in the initial three steps of melanin biosynthesis resulted in an altered conidial surface with masked surface rodlet layer, leaky cell wall allowing the deposition of proteins on the cell surface and exposing the otherwise-masked cell wall polysaccharides at the surface. Melanin as such was immunologically inert; however, deletion mutant conidia with modified surfaces could activate human dendritic cells and the subsequent cytokine production in contrast to the wild-type conidia. Cell surface defects were rectified in the conidia mutated in downstream melanin biosynthetic pathway, and maximum immune inertness was observed upon synthesis of vermelone onward. These observations suggest that although melanin as such is an immunologically inert material, it confers virulence by facilitating proper formation of the A. fumigatus conidial surface.

  12. Insulin-sensitizing and beneficial lipid-metabolic effects of the water-soluble melanin complex extracted from Inonotus obliquus.

    Science.gov (United States)

    Lee, Jung-Han; Hyun, Chang-Kee

    2014-09-01

    Inonotus obliquus has been traditionally used for treatment of metabolic diseases; however, the mechanism remains to be elucidated. In this study, we found that the water-soluble melanin complex extracted from I. obliquus improved insulin sensitivity and reduced adiposity in high fat (HF)-fed obese mice. When the melanin complex was treated to 3T3-L1 adipocytes, insulin-stimulated glucose uptake was increased significantly, and its phosphoinositide 3-kinase-dependent action was proven with wortmannin treatment. Additionally, dose-dependent increases in Akt phosphorylation and glucose transporter 4 translocation into the plasma membrane were observed in melanin complex-treated cells. Adiponectin gene expression in 3T3-L1 cells incubated with melanin complex increased which was corroborated by increased AMP-activated protein kinase phosphorylation in HepG2 and C2C12 cells treated with conditioned media from the 3T3-L1 culture. Melanin complex-treated 3T3-L1 cells showed no significant change in expression of several lipogenic genes, whereas enhanced expressions of fatty acid oxidative genes were observed. Similarly, the epididymal adipose tissue of melanin complex-treated HF-fed mice had higher expression of fatty acid oxidative genes without significant change in lipogenic gene expression. Together, these results suggest that the water-soluble melanin complex of I. obliquus exerts antihyperglycemic and beneficial lipid-metabolic effects, making it a candidate for promising antidiabetic agent.

  13. Role of melanin in release of extracellular enzymes and selection of aggressive isolates of Bipolaris sorokiniana in barley.

    Science.gov (United States)

    Chand, Ramesh; Kumar, Manoj; Kushwaha, Chanda; Shah, Kavita; Joshi, Arun K

    2014-08-01

    Eighteen barley isolates of Bipolaris sorokiniana belonging to wild and clonal type of black, mixed and white subpopulations were quantitatively assayed for their melanin content and aggressiveness with respect to production of some of the extracellular enzymes such as cellulase, pectinase, amylase and protease. Cellulase and pectinase constituted major portion of the enzymes recovered from the black, mixed and white isolates. Enzyme production and aggressiveness were relatively higher in melanin devoid or low melanin isolates. The melanin deficient isolates were also differentiated from black and mixed isolates on the basis of variation in internal transcribed spacer region of the ribosomal DNA. Higher enzyme productions positively correlated with area under disease progress curve (AUDPC) and lesion development. Melanin content was negatively correlated with extracellular enzymes and aggressiveness of the isolates. Based on melanin content, lesion size, AUDPC and extracellular enzymes, the isolates were grouped in two major clusters (I and II) with further division of cluster II into two sub-clusters (II-A and II-B). The results appears to indicate a possible role of melanin in release of extracellular enzymes and hence in evolution and selection of aggressive isolates of B. sorokiniana in barley.

  14. Melanin and Cryptococcus neoformans%黑素与新生隐球菌

    Institute of Scientific and Technical Information of China (English)

    王雪连; 孔庆涛; 王高峰; 刘芳; 邓德权; 桑红

    2011-01-01

    黑素的产生与多种微生物的毒力相关.新生隐球菌主要通过酚氧化酶(漆酶)合成黑素,黑素主要通过抵抗宿主微生物杀伤机制和影响宿主免疫应答来致病.主要就新生隐球菌黑素的微观结构、生物合成,漆酶的分子调节,黑素与新生隐球菌毒力的关系,黑化对真菌生存的影响及与抗真菌治疗的关系等方面进行概述,以期通过对黑素特征的理解为抗真菌药物的开发和对疾病的治疗策略选择提供帮助.%The production of melanin is associated with the virulence of various microorganisms.Cryptococcus neoformans produces melanin mainly via phenoloxidase(laccase)pathway.Melanin contributes to virulence likely by reducing the susceptibility of melanized fungi to host defense mechanisms and affecting immune responses in infected hosts.This review mainly focuses on the microstructure and biosynthesis of Cryptococcus neoformans melanin, molecular regulation of laecase, relationship between melanin and Cryptococcus neoformans virulence, effects of melanization on the survival of fungi, relationship between melanization and antifungal treatment, ete, which may facilitate the design and development of antifungal agents and strategies.

  15. DRUGS CAUSING OROFACIAL PIGMENTATION: AN OVERVIEW OF LITERATURE

    OpenAIRE

    Shamimul Hasan; Nabeel Ishrat Khan; Osama Adeel Khan Sherwani; Shane Rafi; Ayesha Siddiqui

    2013-01-01

    The term “Oro-facial pigmentation” refers to a wide range of lesions or conditions featuring a change of color of Oro-facial tissues. Pigmentation of the Oro-facial tissues is seen in certain races or ethnic groups such as Indians, Africans and Europeans. Broadly classifying, Oro-facial pigmentation is divided into endogenous pigmentation and exogenous pigmentation. Endogenous pigmentation is due to pigments produced within the body. Exogenous pigmentation occurs when foreign bodies get impre...

  16. Picobiophotonics for the investigation of pigment-pigment and pigment-protein interactions in photosynthetic complexes

    OpenAIRE

    Schmitt, Franz-Josef

    2011-01-01

    Anregungsenergietransfer-(EET)-prozesse wurden in verschiedenen photosynthetischen Pigment-Protein-Komplexen mit zeit- und wellenlängenkorrelierter Einzelphotonenspektroskopie (TWCSPC) analysiert. Ein neuer mobiler 16-Kanal Photomultiplier mit flexibler Faseroptik, austauschbaren Lichtquellen und einem Kryostaten (10 K – 350 K) wurde für die Spektroskopie von Proben in Küvetten, auf Oberflächen oder von ganzen Blättern in vivo aufgebaut. Das System stellt einen mobilen Messplatz auf Grundlage...

  17. Immunolocalization of lactoferrin in surgically resected pigmented skin lesions

    Directory of Open Access Journals (Sweden)

    G Tuccari

    2009-06-01

    Full Text Available Lactoferrin (Lf expression was determined immunohistochemically in 57 formalin-fixed paraffin-embedded bioptic samples obtained from an equal number of patients treated by surgery to remove pigmented skin lesions (nevi = 23; melanoma = 12; vulgaris and seborrhoeic warts = 12; basal cell carcinoma = 10; in addition, 10 specimens of normal skin were studied as control. On 3 ?m thick sections, depigmentation and antigen retrieval procedures were performed. The Lf immunoreactivity was revealed by a rabbit anti-human Lf. Quantification of Lf immunoreactivity was performed using an intensity-distribution (ID score. Melanocytic cells, regardless of their benign or malignant nature, were consistently stained, with no significant differences in the Lf IDscore between melanomas or nevi. A different intensity of Lf immunoreactivity was encountered in superficial portions of warts, exclusively inside squamous epithelial cells arranged in sheets or whorls of keratin. On the contrary, basal cell carcinomas were always unstained, while a slight Lf positivity was found in focal keratinized areas present in two tumours showing baso-squamous differentiation. The Lf immunoreactivity was localized in the cytoplasm and only occasionally in the nucleus. The biological meaning of Lf in these cases of human skin specimens remains unexplained, although it cannot be ruled out that Lf might be involved in the defense system against tumours, or alternatively, may be used by cells requiring iron availability for their turnover. Moreover, the immunohistochemical expression of Lf in melanocytic lesions might be also related to a Lf-melanin interaction. Finally, the involvement of Lf in skin squamous non-neoplastic elements could be related to its role as one of the molecules modulating an unspecific inflammatory or anti-oxidant response.

  18. Effects of palmitoyl-KVK-L-ascorbic acid on skin wrinkles and pigmentation.

    Science.gov (United States)

    Kim, Hyeong Mi; An, Hyo Sun; Bae, Jung-Soo; Kim, Jung Yun; Choi, Chi Ho; Kim, Ju Yeon; Lim, Joo Hyuck; Choi, Joon-Hun; Song, Hyunnam; Moon, Sung Ho; Park, Young Jun; Chang, Shin-Jae; Choi, Sun Young

    2017-07-01

    Wrinkle formation and abnormal pigmentation are major clinical alterations associated with skin aging. As the aim of our study was to investigate the effects of palmitoyl-KVK-L-ascorbic acid on skin aging, the anti-wrinkle and depigmentation effects of palmitoyl-KVK-L-ascorbic acid were evaluated by measuring collagen expression in dermal fibroblast cells and inhibition of melanogenesis in B16F1 cells, respectively. The anti-aging effect of palmitoyl-KVK-L-ascorbic acid cream was also evaluated against a placebo cream in a clinical trial. Our results confirmed that the expression of type Ι collagen in dermal fibroblast cells treated with palmitoyl-KVK-L-ascorbic acid (0.1-4 μg/mL) increased in a dose-dependent manner. In B16F1 cells, treatment with 20 μg/mL palmitoyl-KVK-L-ascorbic acid reduced the melanin content by approximately 20% compared to alpha-melanocyte stimulating hormone treatment. In the clinical trial, application of palmitoyl-KVK-L-ascorbic acid cream led to an improvement in skin roughness and lightness in 12 and 8 weeks, respectively. Our data show that palmitoyl-KVK-L-ascorbic acid is an effective anti-aging agent that reduces wrinkles and abnormal skin pigmentation.

  19. Ancient origins and multiple appearances of carotenoid-pigmented feathers in birds.

    Science.gov (United States)

    Thomas, Daniel B; McGraw, Kevin J; Butler, Michael W; Carrano, Matthew T; Madden, Odile; James, Helen F

    2014-08-07

    The broad palette of feather colours displayed by birds serves diverse biological functions, including communication and camouflage. Fossil feathers provide evidence that some avian colours, like black and brown melanins, have existed for at least 160 million years (Myr), but no traces of bright carotenoid pigments in ancient feathers have been reported. Insight into the evolutionary history of plumage carotenoids may instead be gained from living species. We visually surveyed modern birds for carotenoid-consistent plumage colours (present in 2956 of 9993 species). We then used high-performance liquid chromatography and Raman spectroscopy to chemically assess the family-level distribution of plumage carotenoids, confirming their presence in 95 of 236 extant bird families (only 36 family-level occurrences had been confirmed previously). Using our data for all modern birds, we modelled the evolutionary history of carotenoid-consistent plumage colours on recent supertrees. Results support multiple independent origins of carotenoid plumage pigmentation in 13 orders, including six orders without previous reports of plumage carotenoids. Based on time calibrations from the supertree, the number of avian families displaying plumage carotenoids increased throughout the Cenozoic, and most plumage carotenoid originations occurred after the Miocene Epoch (23 Myr). The earliest origination of plumage carotenoids was reconstructed within Passeriformes, during the Palaeocene Epoch (66-56 Myr), and not at the base of crown-lineage birds.

  20. The effect of niacinamide on reducing cutaneous pigmentation and suppression of melanosome transfer.

    Science.gov (United States)

    Hakozaki, T; Minwalla, L; Zhuang, J; Chhoa, M; Matsubara, A; Miyamoto, K; Greatens, A; Hillebrand, G G; Bissett, D L; Boissy, R E

    2002-07-01

    Cutaneous hyperpigmentation occurs in multiple conditions. In addition, many Asian women desire a lighter skin colour. Thus, there is a need for the development of skin lightening agents. Niacinamide is a possible candidate. To investigate the effects of niacinamide on melanogenesis in vitro and on facial hyperpigmentation and skin colour in vivo in Japanese women. Melanin production was measured in a purified mushroom tyrosinase assay, cultured melanocytes, a keratinocyte/melanocyte coculture model, and a pigmented reconstructed epidermis (PREP) model. The clinical trials included 18 subjects with hyperpigmentation who used 5% niacinamide moisturizer and vehicle moisturizer in a paired design, and 120 subjects with facial tanning who were assigned to two of three treatments: vehicle, sunscreen and 2% niacinamide + sunscreen. Changes in facial hyperpigmentation and skin colour were objectively quantified by computer analysis and visual grading of high-resolution digital images of the face. Niacinamide had no effect on the catalytic activity of mushroom tyrosinase or on melanogenesis in cultured melanocytes. However, niacinamide gave 35-68% inhibition of melanosome transfer in the coculture model and reduced cutaneous pigmentation in the PREP model. In the clinical studies, niacinamide significantly decreased hyperpigmentation and increased skin lightness compared with vehicle alone after 4 weeks of use. The data suggest niacinamide is an effective skin lightening compound that works by inhibiting melanosome transfer from melanocytes to keratinocytes.

  1. Pigmentation genes link Parkinson's disease to melanoma, opening a window on both etiologies.

    Science.gov (United States)

    Herrero Hernández, Elena

    2009-03-01

    Melanomas occur more frequently among subjects with Parkinson's disease (PD) and a biological explanation for this epidemiological observation is lacking. It is also well-known that pigmentation genes play an important role in the development of melanomas. It is therefore suggested that the link between both diseases resides in genes that regulate pigmentation. Among these, those involved in the synthesis of dopamine and related compounds as melanin appear to be the most plausible candidates. Whilst it is known that individuals with fair phototypes have an increased risk for melanoma, this hypothesis suggests that the same applies to Parkinson's disease. It is therefore postulated that the accurate analysis of the phototype could be used to identify subjects at higher risk for both diseases, possibly allowing preventative interventions (photoprotective, nutritional, occupational) and prediction of risk in childhood. Another possible implication of this hypothesis is that therapeutic strategies targeting melanogenesis could maintain or perhaps restore the physiological concentrations of neuromelanin in the substantia nigra and achieve protection against neuronal loss in subjects at risk of developing PD.

  2. Differences in wing melanization and pigmentation pattern in Drosophila buzzatii (Diptera: Drosophilidae under chemical stress Diferencias en la melanización y el patrón de pigmentación alar en Drosophila buzzatii (Diptera: Drosophilidae bajo estrés químico

    Directory of Open Access Journals (Sweden)

    Nicolás Mongiardino Koch

    2012-06-01

    Full Text Available Recently, the genetic basis and developmental mechanisms underlying the process of melanization have become progressively elucidated, allowing us to study the evolutionary processes that govern the huge variability of pigmentation observed in nature. However, environmental factors contributing to such variability have received little attention, even though they might have profound ecological consequences. Here we describe a method for analyzing the wing melanization patterns of drosophilids in both qualitative and quantitative ways. We test this method on wings of Drosophila buzzatii Patterson & Wheeler individuals, reared in control and alkaloid-enriched mediums. The alkaloids were extracted from the secondary host of these flies, Echinopsis terscheckii (Parm. ex Pfeiff. Friedrich & Rowley, and their effect on wing pigmentation is analyzed, bearing in mind the adverse effects that these compounds have on the development of D. buzzatii. Alkaloid-reared flies were shown to attain a higher degree of wing melanization, accompanied with differences in the spatial distribution of the pigment. Modifications at both metabolic and gene regulatory levels are proposed to explain the changes that chemical stressful conditions are shown to induce in this character. We propose the utilization of this procedure in studies of environmental dependence of pigmentation.Recientemente, hemos avanzado en nuestra comprensión de las bases genéticas y los mecanismos subyacentes al proceso de melanización durante el desarrollo, lo que permite el estudio de los procesos evolutivos que gobiernan la variabilidad de pigmentación presente en la naturaleza. Sin embargo, los factores ambientales que contribuyen a dicha variabilidad han recibido poca atención, aún cuando pueden conllevar profundas consecuencias a nivel ecológico. En este trabajo, presentamos un método para analizar los patrones de melanización alar de drosofílidos, de forma cualitativa y cuantitativa

  3. Hematite photoanode co-functionalized with self-assembling melanin and C-phycocyanin for solar water splitting at neutral pH

    Energy Technology Data Exchange (ETDEWEB)

    Schrantz, Krisztina; Wyss, Pradeep P.; Ihssen, Julian; Toth, Rita; Bora, Debajeet K.; Vitol, Elina A.; Rozhkova, Elena A.; Pieles, Uwe; Thöny-Meyer, Linda; Braun, Artur

    2017-04-01

    tNature provides functional units which can be integrated in inorganic solar cell materials, such as lightharvesting antenna proteins and photosynthetic molecular machineries, and thus help in advancing artifi-cial photosynthesis. Their integration needs to address mechanical adhesion, light capture, charge transferand corrosion resistance. We showed recently how enzymatic polymerization of melanin can immobi-lize the cyanobacterial light harvesting protein C-phycocyanin on the surface of hematite, a prospectivemetal oxide photoanode for solar hydrogen production by water splitting in photoelectrochemical cells.After the optimization of the functionalization procedure, in this work we show reproducible hydrogenproduction, measured parallel to the photocurrent on this bio-hybrid electrode in benign neutral pHphosphate. Over 90% increase compared to the photocurrent of the pristine hematite could be achieved.The hydrogen evolution was monitored during the photoelectrochemical measurement in an improvedphotoelectrochemical cell. The C-phycocyanin-melanin coating on the hematite was shown to exhibit acomb-like fractal pattern. Raman spectroscopy supported the presence of the protein on the hematiteanode surface. The stability of the protein coating is demonstrated during the 2 h GC measurement andthe 24 h operando current density measurement

  4. Natural food pigments application in food products

    Directory of Open Access Journals (Sweden)

    Emilia Janiszewska-Turak

    2016-12-01

    Full Text Available Natural pigments, food compounds, are responsible for the colour of the products. These additives can impart, to deepen or renew the colour of the product, if it has been lost while processing. They also improve the taste of the product and facilitate its identification. It is hard to imagine today’s food industry without the use of pigments. Presently, more and more conscious con­sumers are demanding products to be coloured with natural pigments or any pigment added to the final product. Artificial pigments are considered to be harmful and undesirable so food manufacturers focus on the use of natural colour substances. 16 natural pigments are presently permitted to be used. These compounds are: betalains – betanin, quinones – cochineal, flavonoids – anthocyan­ins, isoprenoids – carotene, annatto (bixin, norbixin, paprika extract, lutein, canthaxanthin, porphyrins – chlorophylls and chlorophyllins and copper complexes of these compounds, and others: caramels, curcumin, or plant coal.

  5. Photostability of natural orange-red and yellow fungal pigments in liquid food model systems.

    Science.gov (United States)

    Mapari, Sameer A S; Meyer, Anne S; Thrane, Ulf

    2009-07-22

    The variation in the photostability among the currently authorized natural pigments limits their application span to a certain type of food system, and more robust alternatives are being sought after to overcome this problem. In the present study, the photostability of an orange-red and a yellow fungal pigment extract produced by ascomycetous fungi belonging to the genera Penicillium and Epicoccum , respectively, were studied in a soft drink model medium and in citrate buffer at low and neutral pH. The quantitative and qualitative color change pattern of the fungal pigment extracts indicated an enhanced photostability of fungal pigment extracts compared to the commercially available natural colorants Monascus Red and turmeric used as controls. Yellow components of the orange-red fungal pigment extract were more photostable than the red components. Chemistry of the photodegradation of the orange-red pigment extract was studied by high-performance liquid chromatography-diode array detection-mass spectrometry (HPLC-DAD-MS), and a light-induced formation of a structural analogue of sequoiamonascin C, a Monascus -like polyketide pigment discovered in the extract of Penicillium aculeatum IBT 14263 on yeast extract sucrose (YES) medium, was confirmed in the soft drink medium at pH 7.

  6. Argon Laser Photoablation for Postburn Conjunctival Pigmentation

    Directory of Open Access Journals (Sweden)

    Seong Joon Ahn

    2014-01-01

    Full Text Available We report a case of an ocular burn injury from boiling water which resulted in conjunctival pigmentation, 1 week following injury. For cosmetic purposes, 2 sessions of argon laser photoablation were performed. One month after laser treatment, conjunctival pigmentation had been successfully removed and the patient was very satisfied with the results. Argon laser photoablation may be an effective way to remove postburn conjunctival pigmentation.

  7. PRODUCTION OF MONASCUS-LIKE AZAPHILONE PIGMENT

    DEFF Research Database (Denmark)

    2009-01-01

    The present invention relates to the field of biotechnological production of polyketide based colorants from filamentous fungi, in particular a method for preparing a biomass comprising a Monascus-like pigment composition from a nontoxigenic and non-pathogenic fungal source. The present invention...... further relates to use of the Monascus-like pigment composition as a colouring agent for food items and/or non-food items, and a cosmetic composition comprising the Monascus-like pigment composition....

  8. PP-O and PP-V, Monascus pigment homologues, production, and phylogenetic analysis in Penicillium purpurogenum.

    Science.gov (United States)

    Arai, Teppei; Kojima, Ryo; Motegi, Yoshiki; Kato, Jun; Kasumi, Takafumi; Ogihara, Jun

    2015-12-01

    The production of pigments as secondary metabolites by microbes is known to vary by species and by physiological conditions within a single strain. The fungus strain Penicillium purpurogenum IAM15392 has been found to produce violet pigment (PP-V) and orange pigment (PP-O),Monascus azaphilone pigment homologues, when grown under specific culture conditions. In this study, we analysed PP-V and PP-O production capability in seven strains of P. purpurogenum in addition to strain IAM15392 under specific culture conditions. The pigment production pattern of five strains cultivated in PP-V production medium was similar to that of strain IAM15392, and all violet pigments produced by these five strains were confirmed to be PP-V. Strains that did not produce pigment were also identified. In addition, two strains cultivated in PP-O production medium produced a violet pigment identified as PP-V. The ribosomal DNA (rDNA) internal transcribed spacer (ITS) region sequences from the eight P. purpurogenum strains were sequenced and used to construct a neighbor-joining phylogenetic tree. PP-O and PP-V production of P. purpurogenum was shown to be related to phylogenetic placement based on rDNA ITS sequence. Based on these results, two hypotheses for the alteration of pigment production of P. purpurogenum in evolution were proposed.

  9. Berberine regulates melanin synthesis by activating PI3K/AKT, ERK and GSK3β in B16F10 melanoma cells.

    Science.gov (United States)

    Song, Young Chan; Lee, Yonghee; Kim, Hyeong Mi; Hyun, Moo Yeol; Lim, Yun Young; Song, Kye Yong; Kim, Beom Joon

    2015-04-01

    Berberine, an isoquinoline alkaloid, has a wide range of beneficial properties, including anti-bacterial, anti-inflammatory, anti-cancer, and cholesterol-lowering effects. Recently findings suggest that berberine improves glucose and lipid metabolism disorders. In the present study, we examined the mechanism underlying the inhibitory effect of berberine on α-melanocyte-stimulating hormone (α-MSH)-stimulated B16F10 melanoma cells. The results showed that berberine attenuated α-MSH induction of the microphthalmia-associated transcription factor (MITF) and tyrosinase in a dose-dependent manner. To elucidate the mechanism underlying the inhibitory effect of berberine, we examined the effect of α-MSH-stimulated phosphorylation of PI3K/AKT, ERK, and GSK3β. The results showed that treatment with berberine resulted in a reduction in the phosphorylation of PI3K/AKT, ERK, and GSK3β. Taken together, the results suggested that berberine inhibits melanin synthesis and tyrosinase activity by downregulating the expression of MITF and tyrosinase. Thus, these findings may contribute to the potential application of berberine in the prevention and treatment of skin pigmentation disorders.

  10. Non-photosynthetic pigments as potential biosignatures

    Science.gov (United States)

    Schwieterman, E. W.; Cockell, C. S.; Meadows, V. S.

    2014-03-01

    Photosynthetic organisms on Earth produce potentially detectable surface reflectance biosignatures due in part to the spectral location and strength of pigment absorption. However, life on Earth uses pigments for a multitude of purposes other than photosynthesis, including coping with extreme environments. Macroscopic environments exist on Earth where the surface reflectance is significantly altered by a nonphotosynthetic pigment, such as the case of hypersaline lakes and ponds (Oren et al. 1992). Here we explore the nature and potential detectability of non-photosynthetic pigments in disk-averaged planetary observations using a combination of laboratory measurements and archival reflectance spectra, along with simulated broadband photometry and spectra. The in vivo visible reflectance spectra of a cross section of pigmented microorganisms are presented to illustrate the spectral diversity of biologically produced pigments. Synthetic broadband colors are generated to show a significant spread in color space. A 1D radiative transfer model (Meadows & Crisp 1996; Crisp 1997) is used to approximate the spectra of scenarios where pigmented organisms are widespread on planets with Earth-like atmospheres. Broadband colors are revisited to show that colors due to surface reflectivity are not robust to the addition of scattering and absorption effects from the atmosphere. We consider a èbest case' plausible scenario for the detection of nonphotosynthetic pigments by using the Virtual Planetary Laboratory's 3D spectral Earth model (Robinson et al. 2011) to explore the detectability of the surface biosignature produced by pigmented halophiles that are widespread on an Earth-analog planet.

  11. Ultraviolet pigments in birds evolved from violet pigments by a single amino acid change

    OpenAIRE

    Yokoyama, Shozo; Radlwimmer, F. Bernhard; Blow, Nathan S.

    2000-01-01

    UV vision has profound effects on the evolution of organisms by affecting such behaviors as mating preference and foraging strategies. Despite its importance, the molecular basis of UV vision is not known. Here, we have transformed the zebra finch UV pigment into a violet pigment by incorporating one amino acid change, C84S. By incorporating the reverse mutations, we have also constructed UV pigments from the orthologous violet pigments of the pigeon and chicken. These results and comparative...