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Tyrosinase

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https://www.readbyqxmd.com/read/27919619/microsatellite-polymorphism-located-immediately-upstream-of-the-phosphatidylinositol-glycan-class-k-gene-pigk-affects-its-expression-which-correlates-with-tyrosinase-activity-in-human-melanocytes
#1
Ken Okamura, Masahiro Hayashi, Yuko Abe, Yuta Araki, Yutaka Hozumi, Tamio Suzuki
BACKGROUND: Glycosylphosphatidylinositol (GPI) acts as a membrane anchor and a post-translational modifier for more than 150 proteins (called GPI-anchored proteins: GPI-APs). However, little study has been done to explore the role of GPI-APs in melanocytes. METHODS: The relationship between the mRNA expression of the genes which play essential roles in GPI anchoring system [phosphatidylinositol glycan, class A, and class K gene (PIGA, PIGK)] and melanogenesis-related genes (MITF, TYRP1, TYRP2, and TYR) as well as DOPA oxidase activities were evaluated in 13 different normal human epidermal melanocytes (NHEMs)...
November 27, 2016: Journal of Dermatological Science
https://www.readbyqxmd.com/read/27918305/tuberous-sclerosis-complex-inactivation-disrupts-melanogenesis-via-mtorc1-activation
#2
Juxiang Cao, Magdalena E Tyburczy, Joel Moss, Thomas N Darling, Hans R Widlund, David J Kwiatkowski
Tuberous sclerosis complex (TSC) is an autosomal dominant tumor-suppressor gene syndrome caused by inactivating mutations in either TSC1 or TSC2, and the TSC protein complex is an essential regulator of mTOR complex 1 (mTORC1). Patients with TSC develop hypomelanotic macules (white spots), but the molecular mechanisms underlying their formation are not fully characterized. Using human primary melanocytes and a highly pigmented melanoma cell line, we demonstrate that reduced expression of either TSC1 or TSC2 causes reduced pigmentation through mTORC1 activation, which results in hyperactivation of glycogen synthase kinase 3β (GSK3β), followed by phosphorylation of and loss of β-catenin from the nucleus, thereby reducing expression of microphthalmia-associated transcription factor (MITF), and subsequent reductions in tyrosinase and other genes required for melanogenesis...
December 5, 2016: Journal of Clinical Investigation
https://www.readbyqxmd.com/read/27912751/anti-aging-and-tyrosinase-inhibition-effects-of-cassia-fistula-flower-butanolic-extract
#3
Pornngarm Limtrakul, Supachai Yodkeeree, Pilaiporn Thippraphan, Wanisa Punfa, Jatupol Srisomboon
BACKGROUND: Natural products made from plant sources have been used in a variety of cosmetic applications as a source of nutrition and as a whitening agent. The flowers of Cassia fistula L, family Fabaceae, have been used as a traditional medicine for skin diseases and wound healing and have been reported to possess anti-oxidant properties. The anti-aging effect of C. fistula flower extract on human skin fibroblast was investigated. METHODS: The butanolic extraction of C...
December 3, 2016: BMC Complementary and Alternative Medicine
https://www.readbyqxmd.com/read/27910199/reverse-phase-compatible-tlc-bioautography-for-detection-of-tyrosinase-inhibitors
#4
Paula García, I Ayelen Ramallo, Ricardo L E Furlan
INTRODUCTION: Reverse phase chromatography and bioautographic assays are key tools for natural product bioguided isolation; however, their direct coupling has not been fully achieved. OBJECTIVES: To develop a bioautographic assay to detect tyrosinase inhibitors present in complex matrices sorbed on reverse phase (RP) TLC-plates that can be used for bioguided isolation of bioactive compounds. METHODS: Enzyme gel entrapment with an amphiphilic copolymer was used for assay development...
December 2, 2016: Phytochemical Analysis: PCA
https://www.readbyqxmd.com/read/27902928/effects-of-aqueous-extracts-of-ecliptae-herba-polygoni-multiflori-radix-praeparata-and-rehmanniae-radix-praeparata-on-melanogenesis-and-the-migration-of-human-melanocytes
#5
Ping Xu, Shulan Su, Cheng Tan, Ren-Sheng Lai, Zhong-Sheng Min
ETHNOPHARMACOLOGICAL RELEVANCE: Polygoni multiflori radix praeparata (PMRP), Ecliptae herba (EH) and Rehmanniae radix praeparata (RRP) are the most frequently-used herbs by Traditional Chinese Medicine practitioners for the treatment of vitiligo. Their abilities to stimulate melanogenesis, melanocyte migration and MITF (microphthalmia associated transcription factor) protein expression were evaluated in this study. MATERIALS AND METHODS: The effects of aqueous extracts of PMRP, EH and RRP on human melanocytes in vitro were examined by MTT assay, tyrosinase activity, melanin synthesis, migration assay and Western blot...
November 28, 2016: Journal of Ethnopharmacology
https://www.readbyqxmd.com/read/27892691/a-new-sulfonylated-flavonoid-and-other-bioactive-compounds-isolated-from-the-aerial-parts-of-cotula-anthemoides-l
#6
Wafa Tadrent, Abdulmagid Alabdul Magid, Ahmed Kabouche, Dominique Harakat, Laurence Voutquenne-Nazabadioko, Zahia Kabouche
A new sulfonyl flavonol glucoside, 5,7,4',5'-tetrahydoxyflavonol 2'-[propanoic acid-(2″'-acetoxy-1″'-sulfonyl)]-5'-O-β-d-glucopyranoside (1) was isolated from the aerial parts of Cotula anthemoides L. in addition to 15 known compounds (2-16). The structure elucidation of these compounds was based on analyses of spectroscopic data including 1D-, 2D-NMR and HR-ESI-MS techniques and by comparing their NMR data with those reported in the literature. These compounds were evaluated for their DPPH radical scavenging and tyrosinase inhibitory activity...
November 28, 2016: Natural Product Research
https://www.readbyqxmd.com/read/27882071/pigmentation-effect-of-rice-bran-extracted-minerals-comprising-soluble-silicic-acids
#7
Hyun-Jun Jang, Young-Kwon Seo
Our investigation focused on identifying melanogenesis effect of soluble minerals in rice bran ash extract (RBE) which include orthosilicic acid (OSA). Melanocytes were apparently normal in terms of morphology. It was, however, shown that they were stressed a little in the RBE and OSA added media in aspect of LDH activity. Melanin synthesis and intracellular tyrosinase activity were increased by treatment of RBE which is similar to that of OSA. The Western blotting results showed that TRP-1, tyrosinase, and MITF expression levels were 2-3 times higher in the OSA and RBE groups compared to the control group which promoted melanin synthesis through CREB phosphorylation...
2016: Evidence-based Complementary and Alternative Medicine: ECAM
https://www.readbyqxmd.com/read/27879645/bio-guided-isolation-of-methanol-soluble-metabolites-of-common-spruce-picea-abies-bark-by-products-and-investigation-of-their-dermo-cosmetic-properties
#8
Apostolis Angelis, Jane Hubert, Nektarios Aligiannis, Rozalia Michalea, Amin Abedini, Jean-Marc Nuzillard, Sophie C Gangloff, Alexios-Leandros Skaltsounis, Jean-Hugues Renault
Common spruce (Picea abies L.) is a fast-growing coniferous tree, widely used in several countries for the production of sawn wood, timber and pulp. During this industrial exploitation, large quantities of barks are generated as waste materials. The aim of this study was the bio-guided investigation and the effective recovery of methanol-soluble metabolites of common spruce bark for the development of new dermo-cosmetic agents. The active methanol extract was initially fractionated by Centrifugal Partition Chromatography (CPC) using a triphasic solvent system in a step-gradient elution mode...
November 21, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/27872930/the-inhibition-effect-of-starch-nanoparticles-on-tyrosinase-activity-and-its-mechanism
#9
Jie Yang, Ranran Chang, Shengju Ge, Mei Zhao, Caifeng Liang, Liu Xiong, Qingjie Sun
The objective of the current research was to investigate the effects of starch nanoparticles (SNPs) prepared from waxy maize, potato, normal corn, and tapioca starches on the activity of tyrosinase. As a main polyphenol oxidase, tyrosinase not only induces fruit and vegetable browning but also causes skin diseases by overproducing melanin. Herein, for the first time, we evaluated the inhibitory kinetics of SNPs on tyrosinase. It turned out that SNPs inhibited tyrosinase activity reversibly. The IC50 values of hollow nanoparticles, amylopectin nanoparticles, corn starch nanoparticles, and tapioca starch nanoparticles were 0...
November 22, 2016: Food & Function
https://www.readbyqxmd.com/read/27869664/anti-melanogenic-activity-of-gagunin-d-a-highly-oxygenated-diterpenoid-from-the-marine-sponge-phorbas-sp-via-modulating-tyrosinase-expression-and-degradation
#10
Ho Yeon Lee, Eun Jeong Jang, Song Yi Bae, Ju-Eun Jeon, Hyen Joo Park, Jongheon Shin, Sang Kook Lee
Tyrosinase is the rate-limiting enzyme critical for melanin synthesis and controls pigmentation in the skin. The inhibition of tyrosinase is currently the most common approach for the development of skin-whitening cosmetics. Gagunin D (GD), a highly oxygenated diterpenoid isolated from the marine sponge Phorbas sp., has exhibited cytotoxicity toward human leukemia cells. However, the effect of GD on normal cells and the molecular mechanisms remain to be elucidated. In the present study, we identified for the first time the anti-melanogenic activity of GD and its precise underlying mechanisms in mouse melan-a cells...
November 17, 2016: Marine Drugs
https://www.readbyqxmd.com/read/27862041/screening-of-tyrosinase-inhibitors-by-capillary-electrophoresis-with-immobilized-enzyme-microreactor-and-molecular-docking
#11
Mengxia Cheng, Zilin Chen
A new method for screening tyrosinase inhibitors from traditional Chinese medicines (TCM) was successfully developed by capillary electrophoresis with reliable online immobilized enzyme microreactor (IMER). In addition, molecular docking study has been used for supporting inhabitation interaction between enzyme and inhibitors. The IMER of tyrosinase was constructed at the outlet of the capillary by using glutaraldehyde as cross-linker. The parameters including enzyme reaction, separation of the substrate and product, and the performance of immobilized tyrosinase were investigated systematically...
November 10, 2016: Electrophoresis
https://www.readbyqxmd.com/read/27858273/comparison-of-the-phytoremediation-potentials-of-medicago-falcata-l-and-medicago-sativa-l-in-aged-oil-sludge-contaminated-soil
#12
Leonid Panchenko, Anna Muratova, Olga Turkovskaya
Thirteen-year monitoring of the vegetation growing in the industrial and adjacent areas of an oil refinery showed the prevalence of yellow medick (Medicago falcata L.) over other plant species, including alfalfa (Medicago sativa L.). A comparative field study of the two Medicago species established that yellow medick and alfalfa exhibited similar resistance to soil petroleum hydrocarbons and that the pollutant concentration in their rhizosphere was 30% lower than that in the surrounding bulk soil. In laboratory pot experiments, yellow medick reduced the contaminant content by 18% owing to the degradation of the major heavy oil fractions, such as paraffins, naphthenes, and alcohol and benzene tars; and it was more successful than alfalfa...
November 17, 2016: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/27851907/the-depigmenting-effect-of-natural-resorcinol-type-polyphenols-kuwanon-o-and-sanggenon-t-from-the-roots-of-morus-australis
#13
Shuting Hu, Zongping Zheng, Feng Chen, Mingfu Wang
ETHNOPHARMACOLOGICAL RELEVANCE: Morus australis, one of the major Morus species growing in East Asia, is rich in phenolic compounds. The extract of M. australis has been used as skin whitening components for a long period. The action mechanisms of its principal constituents are still unclear. This study aims to evaluate the skin lightening effects of phenolic compounds extracted from the root of M. australis in different melanocyte systems and artificial skin models. MATERIALS AND METHODS: The depigmenting effect of resorcinol type polyphenols (RTPs) from the root extract of M...
November 13, 2016: Journal of Ethnopharmacology
https://www.readbyqxmd.com/read/27846985/array-of-biosensors-for-discrimination-of-grapes-according-to-grape-variety-vintage-and-ripeness
#14
C Medina-Plaza, J A de Saja, J A Fernández-Escudero, E Barajas, G Medrano, M L Rodriguez-Mendez
A bioelectronic tongue based on nanostructured biosensors specific for the simultaneous detection of sugars and phenols has been developed. The array combined oxidases and dehydrogenases immobilized on a lipidic layer prepared using the Langmuir-Blodgett technique where Glucose oxidase, d-Fructose dehydrogenase, Tyrosinase or Laccase were imbibed. A phthalocyanine was co-immobilized in the sensing layer and used as electron mediator. The array thus formed has been used to analyze grapes and provides global information about the samples while providing specific information about their phenolic and their sugar content...
December 1, 2016: Analytica Chimica Acta
https://www.readbyqxmd.com/read/27843913/quercetin-as-an-emerging-anti-melanoma-agent-a-four-focus-area-therapeutic-development-strategy
#15
REVIEW
Zoey Harris, Micah G Donovan, Gisele Morais Branco, Kirsten H Limesand, Randy Burd
Replacing current refractory treatments for melanoma with new prevention and therapeutic approaches is crucial in order to successfully treat this aggressive cancer form. Melanoma develops from neural crest cells, which express tyrosinase - a key enzyme in the pigmentation pathway. The tyrosinase enzyme is highly active in melanoma cells and metabolizes polyphenolic compounds; tyrosinase expression thus makes feasible a target for polyphenol-based therapies. For example, quercetin (3,3',4',5,7-pentahydroxyflavone) is a highly ubiquitous and well-classified dietary polyphenol found in various fruits, vegetables, and other plant products including onions, broccoli, kale, oranges, blueberries, apples, and tea...
2016: Frontiers in Nutrition
https://www.readbyqxmd.com/read/27832141/thyroid-hormones-regulate-zebrafish-melanogenesis-in-a-gender-specific-manner
#16
Raúl Guillot, Borja Muriach, Ana Rocha, Josep Rotllant, Robert N Kelsh, José Miguel Cerdá-Reverter
Zebrafish embryos are treated with anti-thyroidal compounds, such as phenylthiourea, to inhibit melanogenesis. However, the mechanism whereby the thyroidal system controls melanin synthesis has not been assessed in detail. In this work, we tested the effect of the administration of diets supplemented with T3 (500μg/g food) on the pigment pattern of adult zebrafish. Oral T3 induced a pronounced skin paling in both adult female and male zebrafish that was reversible upon cessation of treatment. The number of visible melanophores was significantly reduced in treated fish...
2016: PloS One
https://www.readbyqxmd.com/read/27829416/tyrosinase-inhibition-and-antioxidant-properties-of-asphodelus-microcarpus-extracts
#17
Amalia Di Petrillo, Ana Maria González-Paramás, Benedetta Era, Rosaria Medda, Francesca Pintus, Celestino Santos-Buelga, Antonella Fais
BACKGROUND: Asphodelus microcarpus belongs to the family Liliaceae that include several medicinal plants. In the traditional medicine plants of the genus Asphodelus are used to treat skin disorders such as ectodermal parasites, psoriasis, microbial infection and for lightening freckles. In order to find novel skin depigmenting agents, the present work was carry out to evaluate antioxidant activity and tyrosinase inhibitory potential of leaves, flowers and tubers extracts of A. microcarpus...
November 9, 2016: BMC Complementary and Alternative Medicine
https://www.readbyqxmd.com/read/27829221/mutation-analysis-of-a-chinese-family-with-oculocutaneous-albinism
#18
Xiong Wang, Yaowu Zhu, Na Shen, Jing Peng, Chunyu Wang, Haiyi Liu, Yanjun Lu
Oculocutaneous albinism (OCA) is an autosomal recessive disorder characterized by either complete lack of or a reduction in melanin biosynthesis in the skin, hair, and eyes. OCA1, the most common and severe type, is caused by mutations in the tyrosinase (TYR) gene. In this study, we report a Chinese family with two members affected by OCA. Blood samples were collected from all family members. Genomic DNA was isolated from blood leukocytes, and all coding exons and adjacent intronic sequences of the TYR gene were examined for mutation analysis using polymerase chain reaction (PCR)-based sequencing...
November 4, 2016: Oncotarget
https://www.readbyqxmd.com/read/27827938/anti-melanogenic-activities-of-heracleum-moellendorffii-via-erk1-2-mediated-mitf-downregulation
#19
Md Badrul Alam, Bum-Ju Seo, Peijun Zhao, Sang-Han Lee
In this study, the anti-melanogenic effects of Heracleum moellendorffii Hance extract (HmHe) and the mechanisms through which it inhibits melanogenesis in melan-a cells were investigated. Mushroom tyrosinase (TYR) activity and melanin content as well as cellular tyrosinase activity were measured in the cells. mRNA and protein expression of microphthalmia-associated transcription factor (MITF), tyrosinase (TYR), TYR-related protein-1 (TYRP-1) and -2 were also examined. The results demonstrate that treatment with HmHe significantly inhibits mushroom tyrosinase activity...
November 4, 2016: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/27826808/molecular-cloning-and-characteristic-features-of-a-novel-extracellular-tyrosinase-from-aspergillus-niger-pa2
#20
Pragati Agarwal, Jyoti Singh, R P Singh
Aspergillus niger PA2, a novel strain isolated from waste effluents of food industry, is a potential extracellular tyrosinase producer. Enzyme activity and L-DOPA production were maximum when glucose and peptone were employed as C source and nitrogen source respectively in the medium and enhanced notably when the copper was supplemented, thus depicting the significance of copper in tyrosinase activity. Tyrosinase-encoding gene from the fungus was cloned, and amplification of the tyrosinase gene yielded a 1127-bp DNA fragment and 374 amino acid residue long product that encoded for a predicted protein of 42...
November 8, 2016: Applied Biochemistry and Biotechnology
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