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Tyrosinase

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https://www.readbyqxmd.com/read/28333105/anti-melanogenic-properties-of-greek-plants-a-novel-depigmenting-agent-from-morus-alba-wood
#1
Eliza Chaita, George Lambrinidis, Christina Cheimonidi, Adamantia Agalou, Dimitris Beis, Ioannis Trougakos, Emmanuel Mikros, Alexios-Leandros Skaltsounis, Nektarios Aligiannis
In therapeutic interventions associated with melanin hyperpigmentation, tyrosinase is regarded as a target enzyme as it catalyzes the rate-limiting steps in mammalian melanogenesis. Since many known agents have been proven to be toxic, there has been increasing impetus to identify alternative tyrosinase inhibitors, especially from natural sources. In this study, we investigated 900 extracts from Greek plants for potential tyrosinase inhibitive properties. Among the five most potent extracts, the methanol extract of Morus alba wood (MAM) demonstrated a significant reduction in intracellular tyrosinase and melanin content in B16F10 melanoma cells...
March 23, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28330374/recent-developments-in-the-use-of-tyrosinase-and-laccase-in-environmental-applications
#2
Sidy Ba, Vaidyanathan Vinoth Kumar
Our current global environmental challenges include the reduction of harmful chemicals and their derivatives. Bioremediation has been a key strategy to control the massive presence of chemicals in the environment. Enzymes including the phenoloxidases, laccases and tyrosinases, are increasingly being investigated as "green products" in the removal of many chemical contaminants in waters and soils. Both phenoloxidases are widespread in nature and attractive biocatalysts due to their ability to use readily available molecular oxygen as sole cofactor for their catalytic elimination of a large number of chemicals...
March 22, 2017: Critical Reviews in Biotechnology
https://www.readbyqxmd.com/read/28322963/the-effect-of-oxaloacetic-acid-on-tyrosinase-activity-and-structure-integration-of-inhibition-kinetics-with-docking-simulation
#3
Lin Gou, Jinhyuk Lee, Hao Hao, Yong-Doo Park, Yi Zhan, Zhi-Rong Lü
Oxaloacetic acid (OA) is naturally found in organisms and well known as an intermediate of citric acid cycle producing ATP. We evaluated the effects of OA on tyrosinase activity and structure via integrating methods of enzyme kinetics and computational simulations. OA was found to be a reversible inhibitor of tyrosinase and its induced mechanism was the parabolic non-competitive inhibition type (IC50=17.5±0.5mM and Ki=6.03±1.36mM). Kinetic measurements by real-time interval assay showed that OA induced multi-phasic inactivation process composing with fast (k1) and slow (k2) phases...
March 16, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28321929/the-effect-of-butin-on-the-vitiligo-mouse-model-induced-by-hydroquinone
#4
Shi-Xia Huo, Qiong Wang, Xin-Min Liu, Chun-Hui Ge, Li Gao, Xiao-Ming Peng, Ming Yan
Vernonia anthelmintica (L.) Willd has been traditionally used in the treatment of vitiligo in Uyghur medicine. This study used butin, the main component of V. anthelmintica, to study the influence on hydroquinone-induced vitiligo in mice. The animals were randomly divided into six groups: control, model, 8-methoxypsoralen (8-MOP, 4.25 mg/kg), and butin (0.425, 4.25, and 42.5 mg/kg) groups. The number of melanin-containing hair follicles, basal layer melanocytes, melanin-containing epidermal cells, the expression of tyrosinase (TYR) and tyrosinase-related protein-1 (TRP-1), the malondialdehyde (MDA), and cholinesterase (CHE) activity in serum were measured...
March 21, 2017: Phytotherapy Research: PTR
https://www.readbyqxmd.com/read/28298193/identification-of-two-novel-mutations-in-the-slc45a2-gene-in-a-hungarian-pedigree-affected-by-unusual-oca-type-4
#5
Lola Tóth, Beáta Fábos, Katalin Farkas, Adrienn Sulák, Kornélia Tripolszki, Márta Széll, Nikoletta Nagy
BACKGROUND: Oculocutaneous albinism (OCA) is a clinically and genetically heterogenic group of pigmentation abnormalities. OCA type IV (OCA4, OMIM 606574) develops due to homozygous or compound heterozygous mutations in the solute carrier family 45, member 2 (SLC45A2) gene. This gene encodes a membrane-associated transport protein, which regulates tyrosinase activity and, thus, melanin content by changing melanosomal pH and disrupting the incorporation of copper into tyrosinase. METHODS: Here we report two Hungarian siblings affected by an unusual OCA4 phenotype...
March 15, 2017: BMC Medical Genetics
https://www.readbyqxmd.com/read/28296950/cellular-and-molecular-defects-in-a-patient-with-hermansky-pudlak-syndrome-type-5
#6
Joshi Stephen, Tadafumi Yokoyama, Nathanial J Tolman, Kevin J O'Brien, Elena-Raluca Nicoli, Brian P Brooks, Laryssa Huryn, Steven A Titus, David R Adams, Dong Chen, William A Gahl, Bernadette R Gochuico, May Christine V Malicdan
Hermansky-Pudlak syndrome (HPS) is a heterogeneous group of genetic disorders typically manifesting with tyrosinase-positive oculocutaneous albinism, bleeding diathesis, and pulmonary fibrosis, in some subtypes. Most HPS subtypes are associated with defects in Biogenesis of Lysosome-related Organelle Complexes (BLOCs), which are groups of proteins that function together in the formation and/or trafficking of lysosomal-related endosomal compartments. BLOC-2, for example, consists of the proteins HPS3, HPS5, and HPS6...
2017: PloS One
https://www.readbyqxmd.com/read/28289386/traditionally-used-lathyrus-species-phytochemical-composition-antioxidant-activity-enzyme-inhibitory-properties-cytotoxic-effects-and-in-silico-studies-of-l-czeczottianus-and-l-nissolia
#7
Eulogio J Llorent-Martínez, Gokhan Zengin, María L Fernández-de Córdova, Onur Bender, Arzu Atalay, Ramazan Ceylan, Adriano Mollica, Andrei Mocan, Sengul Uysal, Gokalp O Guler, Abdurrahman Aktumsek
Members of the genus Lathyrus are used as food and as traditional medicines. In order to find new sources of biologically-active compounds, chemical and biological profiles of two Lathyrus species (L. czeczottianus and L. nissolia) were investigated. Chemical profiles were evaluated by HPLC-ESI-MS(n), as well as by their total phenolic and flavonoid contents. In addition, antioxidant, enzyme inhibitory, and cytotoxic effects were also investigated. Antioxidant properties were tested by using different assays (DPPH, ABTS, CUPRAC, FRAP, phosphomolybdenum, and metal chelation)...
2017: Frontiers in Pharmacology
https://www.readbyqxmd.com/read/28283753/cosmetic-applications-of-glucitol-core-containing-gallotannins-from-a-proprietary-phenolic-enriched-red-maple-acer-rubrum-leaves-extract-inhibition-of-melanogenesis-via-down-regulation-of-tyrosinase-and-melanogenic-gene-expression-in-b16f10-melanoma-cells
#8
Hang Ma, Jialin Xu, Nicholas A DaSilva, Ling Wang, Zhengxi Wei, Liangran Guo, Shelby L Johnson, Wei Lu, Jun Xu, Qiong Gu, Navindra P Seeram
The red maple (Acer rubrum) is a rich source of phenolic compounds which possess galloyl groups attached to different positions of a 1,5-anhydro-D-glucitol core. While these glucitol-core containing gallotannins (GCGs) have reported anti-oxidant and anti-glycative effects, they have not yet been evaluated for their cosmetic applications. Herein, the anti-tyrosinase and anti-melanogenic effects of a proprietary phenolic-enriched red maple leaves extract [Maplifa(™); contains ca. 45% ginnalin A (GA) along with other GCGs] were investigated using enzyme and cellular assays...
March 10, 2017: Archives of Dermatological Research
https://www.readbyqxmd.com/read/28283243/chemical-synthesis-redox-transformation-and-identification-of-sonnerphenolic-c-an-antioxidant-in-acer-nikoense
#9
Takehiro Iwadate, Ken-Ichi Nihei
Sonnerphenolic C (3), which was predicted in a redox product of epirhododendrin (1) isolated from Acer nikoense, was synthesized for the first time via the epimeric separation of benzylidene acetal intermediates as a key step. From a similar synthetic route, 1 was obtained concisely. As a result of their antioxidative evaluation, only 3 revealed potent activity. The redox transformation of 1 into 3 was achieved in the presence of tyrosinase and vitamin C. Moreover, 3 was identified in the decoction of A. nikoense by HPLC analysis with the effective use of synthesized 3...
February 24, 2017: Bioorganic & Medicinal Chemistry Letters
https://www.readbyqxmd.com/read/28278619/evaluation-of-antioxidant-and-tyrosinase-inhibitory-activities-of%C3%A2-the-extracts-of-sarcopoterium-spinosum-l-spach-fruits
#10
Alessandra Piras, Benedetta Era, Amalia Di Petrillo, Ana María González Paramás, Andrea Maxia, Alfredo Maccioni, Silvia Porcedda, Danilo Falconieri, Antonella Rosa
Sarcopoterium spinosum fruits have been used to get extracts of different nature; two fixed oils were obtained by means of supercritical fluid extraction (SFE) with CO2 at 250 bar and 40°C and using n-hexane in a Soxhlet extraction (SE) apparatus. Aqueous solutions: an aromatic water (AW) and a residual water (RW) were obtained by hydrodistillation (HD). In the RW, following have been identified: quercetin glucuronide, luteolin 7-O-glucuronide, isorhamnetin 3-O-glucuronide, quercetin sulfate and quercetin...
March 6, 2017: Natural Product Research
https://www.readbyqxmd.com/read/28274615/oxidative-metabolism-of-curcumin-glucuronide-by-peroxidases-and-isolated-human-leukocytes
#11
Paula B Luis, Odaine N Gordon, Fumie Nakashima, Akil I Joseph, Takahiro Shibata, Koji Uchida, Claus Schneider
Conjugation with glucuronic acid is a prevalent metabolic pathway of orally administrated curcumin, the bioactive diphenol of the spice turmeric. The major in vitro degradation reaction of curcumin is autoxidative transformation resulting in oxygenation and cyclization of the heptadienedione chain to form cyclopentadione derivatives. Here we show that curcumin-glucuronide is much more stable than curcumin, degrading about two orders of magnitude slower. Horseradish peroxidase-catalyzed oxidation of curcumin-glucuronide occurred at about 80% of the rate with curcumin, achieving efficient transformation...
March 6, 2017: Biochemical Pharmacology
https://www.readbyqxmd.com/read/28273883/chemotypic-characterization-and-biological-activity-of-rosmarinus-officinalis
#12
Prabodh Satyal, Tyler H Jones, Elizabeth M Lopez, Robert L McFeeters, Nasser A Awadh Ali, Iman Mansi, Ali G Al-Kaf, William N Setzer
Rosemary (Rosmarinus officinalis L.) is a popular herb in cooking, traditional healing, and aromatherapy. The essential oils of R. officinalis were obtained from plants growing in Victoria (Australia), Alabama (USA), Western Cape (South Africa), Kenya, Nepal, and Yemen. Chemical compositions of the rosemary oils were analyzed by gas chromatography-mass spectrometry as well as chiral gas chromatography. The oils were dominated by (+)-α-pinene (13.5%-37.7%), 1,8-cineole (16.1%-29.3%), (+)-verbenone (0.8%-16...
March 5, 2017: Foods (Basel, Switzerland)
https://www.readbyqxmd.com/read/28273866/camellia-sinensis-l-extract-and-its-potential-beneficial-effects-in-antioxidant-anti-inflammatory-anti-hepatotoxic-and-anti-tyrosinase-activities
#13
Surached Thitimuta, Pimolpan Pithayanukul, Saruth Nithitanakool, Rapepol Bavovada, Jiraporn Leanpolchareanchai, Patchreenart Saparpakorn
The aims of this study were to investigate the potential benefits of antioxidant, anti-inflammatory, anti-hepatotoxic, and anti-tyrosinase activities of a methanolic extract of fresh tea leaves (FTE) (Camellia sinensis L.). The antioxidant capacity was investigated using three different methods at different temperatures. The anti-inflammatory activity was studied in vitro by the inhibition of 5-lipoxygenase assay. The anti-hepatotoxic effect was investigated in CCl₄-induced liver injury in rats. The anti-tyrosinase activities of the FTE and its principal phenolic compounds were investigated in l-3,4-dihydroxyphenylalanine (l-DOPA) oxidation by a mushroom tyrosinase...
March 4, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28273864/screening-of-peruvian-medicinal-plants-for-tyrosinase-inhibitory-properties-identification-of-tyrosinase-inhibitors-in-hypericum-laricifolium-juss
#14
Yanymee Nimesia Guillen Quispe, Seung Hwan Hwang, Zhiqiang Wang, Soon Sung Lim
Tyrosinase inhibitors are of far-ranging importance in cosmetics, medicinal products, and food industries. Peru is a diverse country with a wide variety of plants that may contain excellent anti-tyrosinase inhibitors. In the present study, the tyrosinase inhibitory properties of 50 medicinal plant extracts from Peru were investigated using tyrosinase assay. Among plant extracts, those that showed an inhibition rate >50% were Hypericum laricifolium Juss., Taraxacum officinaleF.H.Wigg., and Muehlenbeckia vulcanicaMeisn...
March 4, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28273414/oxidase-activity-of-the-barnacle-adhesive-interface-involves-peroxide-dependant-catechol-oxidase-and-lysyl-oxidase-enzymes
#15
Christopher R So, Jenifer M Scancella, Kenan P Fears, Tara Essock-Burns, Sarah E Haynes, Dagmar H Leary, Zoie Diana, Chenyue Wang, Stella H North, Christina S Oh, Zheng Wang, Beatriz Orihuela, Daniel Rittschof, Christopher M Spillmann, Kathryn J Wahl
Oxidases are found to play a growing role in providing functional chemistry to marine adhesives for the permanent attachment of macrofouling organisms. Here, we demonstrate active peroxidase and lysyl oxidase enzymes in the adhesive layer of adult Amphibalanus amphitrite barnacles through live staining, proteomic analysis and competitive enzyme assays on isolated cement. A novel full length peroxinectin (AaPxt-1) secreted by barnacles is largely responsible for oxidizing phenolic chemistries; AaPxt-1 is driven by native hydrogen peroxide in the adhesive and oxidizes phenolic substrates typically preferred by phenoloxidases (POX) such as laccase and tyrosinase...
March 8, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28271633/pheomelanogenesis-is-promoted-at-a-weakly-acidic-ph
#16
Kazumasa Wakamatsu, Ayano Nagao, Miu Watanabe, Kenta Nakao, Shosuke Ito
The diversity of pigmentation in the skin, hair and eyes of humans has been largely attributed to the diversity of pH in melanosomes with an acidic pH being proposed to suppress melanin production, especially eumelanogenesis. We previously showed that an acidic pH greatly suppresses the late stage of eumelanogenesis after the dopachrome stage. The oxidation of tyrosine by tyrosinase in the presence of cysteine forms cysteinyldopa isomers, which are further oxidized to give rise to pheomelanin via benzothiazine intermediates...
March 8, 2017: Pigment Cell & Melanoma Research
https://www.readbyqxmd.com/read/28268138/chemical-and-bioactivity-of-flavanones-obtained-from-roots-of-dalea-pazensis-rusby
#17
María D Santi, Mariana A Peralta, Caterine S Mendoza, José Luis Cabrera, María G Ortega
Two new prenylated flavanones, pazentin A (3',4'-dihydroxy-6,2'-diprenylpinocembrin, 1) and pazentin B [4'-hydroxy-2'-methoxy-5'-(1‴, 1‴-dimethylallyl)-6-prenylpinocembrin, 2] together with two known ones (3 and 4) previously isolated from other Dalea species were obtained from the benzene extract of Dalea pazensis Rusby roots. The compounds were evaluated in vitro for their inhibition on mushroom tyrosinase enzyme and in relation to their effect on melanogenesis in B16 murine melanoma cells, by using a spectrophotometric method...
February 27, 2017: Bioorganic & Medicinal Chemistry Letters
https://www.readbyqxmd.com/read/28263569/inducible-site-specific-protein-labeling-by-tyrosine-oxidation-strain-promoted-4-2-cycloaddition
#18
Jorick J Bruins, Adrie H Westphal, Bauke Albada, Koen Wagner, Lina Bartels, Hergen Spits, Willem J H van Berkel, Floris L van Delft
Genetically encoded tyrosine (Y-tag) can be utilized as a latent anchor for inducible and site-selective conjugation. Upon oxidation of tyrosine with mushroom tyrosinase, strain-promoted cycloaddition (SPOCQ) of the resulting 1,2-quinone with various bicyclo[6.1.0]nonyne (BCN) derivatives led to efficient conjugation. The method was applied for fluorophore labeling of laminarinase A and for the site-specific preparation of an antibody-drug conjugate.
March 16, 2017: Bioconjugate Chemistry
https://www.readbyqxmd.com/read/28263240/peptide-pulsed-dendritic-cell-vaccine-in-combination-with-carboplatin-and-paclitaxel-chemotherapy-for-stage-iv-melanoma
#19
Keitaro Fukuda, Takeru Funakoshi, Toshiharu Sakurai, Yoshio Nakamura, Mariko Mori, Keiji Tanese, Akiko Tanikawa, Junichi Taguchi, Tomonobu Fujita, Masato Okamoto, Masayuki Amagai, Yutaka Kawakami
In this study, we aimed to evaluate the feasibility and efficacy of peptide-pulsed dendritic cell (DC) vaccine in combination with carboplatin and paclitaxel chemotherapy (DCCP) for patients with stage IV melanoma previously treated with dacarbazine-containing regimen. Six HLA-A24 and 3 HLA-A02 patients were treated with carboplatin (area under the curve 5) and paclitaxel (175 mg/m) on day 1 and DCs (2×10 cells) pulsed with Wilms tumor gene 1 (WT1), gp100, tyrosinase, and either MAGE-A3 (for HLA-A24) or MAGE-A2 (for HLA-A02) peptides on days 8 and 22 in 28-day cycle for up to three cycles...
March 3, 2017: Melanoma Research
https://www.readbyqxmd.com/read/28260881/ginseng-berry-mediated-gold-and-silver-nanoparticle-synthesis-and-evaluation-of-their-in-vitro-antioxidant-antimicrobial-and-cytotoxicity-effects-on-human-dermal-fibroblast-and-murine-melanoma-skin-cell-lines
#20
Zuly Elizabeth Jiménez Pérez, Ramya Mathiyalagan, Josua Markus, Yeon-Ju Kim, Hyun Mi Kang, Ragavendran Abbai, Kwang Hoon Seo, Dandan Wang, Veronika Soshnikova, Deok Chun Yang
There has been a growing interest in the design of environmentally affable and biocompatible nanoparticles among scientists to find novel and safe biomaterials. Panax ginseng Meyer berries have unique phytochemical profile and exhibit beneficial pharmacological activities such as antihyperglycemic, antiobesity, antiaging, and antioxidant properties. A comprehensive study of the biologically active compounds in ginseng berry extract (GBE) and the ability of ginseng berry (GB) as novel material for the biosynthesis of gold nanoparticles (GBAuNPs) and silver nanoparticles (GBAgNPs) was conducted...
2017: International Journal of Nanomedicine
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