Interaction of various types of bisphenols with enzymes involved in melanin synthesis

This study was performed to clarify the inhibitory effects of cycloheterophyllin on melanin synthesis. In order to elucidate the inhibitory effects of cycloheterophyllin on the B16F10 cell line, cell viability, messenger ribonucleic acid (mRNA) expressions, tyrosinase activity assay, and melanin production assay were measured. The effects of cycloheterophyllin on tyrosinase-related protein 1 (TYRP1)/TYRP2/tyrosinase (TYR)/microphthalmia-associated transcription factor (MITF) mRNA expressions and melanin content were determined. Quantitative real-time RT-PCR showed that cycloheterophyllin decreased the mRNA expression level of TYRP1/TYRP2/TYR/MITF genes and melanin production contents than α-MSH-treated B16F10 cells. The tyrosinase activity assay revealed that cycloheterophyllin decreased the melanin production in the B16F10 cells. These data show that cycloheterophyllin increases the whitening effects in the B16F10 cells; thus, cycloheterophyllin is a potent ingredient for skin whitening. Thus, further research on the mechanism of action of cycloheterophyllin for the development of functional materials should be investigated.

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Melanin production in coelomycetous agents of black grain eumycetoma

Transactions of the Royal Society of Tropical Medicine and Hygiene ◽

10.1093/trstmh/traa168 ◽

2021 ◽

Author(s):

Wilson Lim ◽

Florianne Parel ◽

Sybren de Hoog ◽

Annelies Verbon ◽

Wendy W J van de Sande

Keyword(s):

Fungal Infection ◽

Therapeutic Targets ◽

Biosynthetic Pathways ◽

Melanin Synthesis ◽

Melanin Production ◽

Causative Agents ◽

New Therapeutic Targets

Abstract Background Eumycetoma is a fungal infection characterised by the formation of black grains by causative agents. The melanin biosynthetic pathways used by the most common causative agents of black-grain mycetoma are unknown and unravelling them could identify potential new therapeutic targets. Method Melanin biosynthetic pathways in the causative fungi were identified by the use of specific melanin inhibitors. Results In Trematosphaeria grisea and Falciformispora tompkinsii, 1,8-dihydroxynaphthalene (DHN)-melanin synthesis was inhibited, while DHN-, 3,4-dihydroxyphenylalanine (DOPA)- and pyo-melanin were inhibited in Medicopsis romeroi and Falciformispora senegalensis. Conclusion Our data suggest that Me. romeroi and F. senegalensis synthesise DHN-, DOPA- and pyo-melanin, while T. grisea and F. tompkinsii only synthesise DHN-melanin.

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Molecular and Biochemical Basis of Minocycline-Induced Hyperpigmentation—The Study on Normal Human Melanocytes Exposed to UVA and UVB Radiation

International Journal of Molecular Sciences ◽

10.3390/ijms22073755 ◽

2021 ◽

Vol 22 (7) ◽

pp. 3755

Author(s):

Jakub Rok ◽

Zuzanna Rzepka ◽

Justyna Kowalska ◽

Klaudia Banach ◽

Artur Beberok ◽

...

Keyword(s):

Uv Radiation ◽

Therapeutic Potential ◽

Melanin Synthesis ◽

Uvb Radiation ◽

Biochemical Basis ◽

Skin Hyperpigmentation ◽

Human Melanocytes ◽

Anti Cancer ◽

Normal Human

Minocycline is a drug which induces skin hyperpigmentation. Its frequency reaches up to 50% of treated patients. The adverse effect diminishes the great therapeutic potential of minocycline, including antibacterial, neuroprotective, anti-inflammatory and anti-cancer actions. It is supposed that an elevated melanin level and drug accumulation in melanin-containing cells are related to skin hyperpigmentation. This study aimed to evaluate molecular and biochemical mechanism of minocycline-induced hyperpigmentation in human normal melanocytes, as well as the contribution of UV radiation to this side effect. The experiments involved the evaluation of cyto- and phototoxic potential of the drug using cell imaging with light and confocal microscopes as well as biochemical and molecular analysis of melanogenesis. We showed that minocycline induced melanin synthesis in epidermal melanocytes. The action was intensified by UV irradiation, especially with the UVB spectrum. Minocycline stimulated the expression of microphthalmia-associated transcription factor (MITF) and tyrosinase (TYR) gene. Higher levels of melanin and increased activity of tyrosinase were also observed in treated cells. Moreover, minocycline triggered the supranuclear accumulation of tyrosinase, similar to UV radiation. The decreased level of premelanosome protein PMEL17 observed in all minocycline-treated cultures suggests disorder of the formation, maturation or distribution of melanosomes. The study revealed that minocycline itself was able to enhance melanin synthesis. The action was intensified by irradiation, especially with the UVB spectrum. Demonstrated results confirmed the potential role of melanin and UV radiation minocycline-induced skin hyperpigmentation.

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Genetic Relationships in the Toxin-Producing Fungal Endophyte, Alternaria oxytropis Using Polyketide Synthase and Non-Ribosomal Peptide Synthase Genes

Journal of Fungi ◽

10.3390/jof7070538 ◽

2021 ◽

Vol 7 (7) ◽

pp. 538

Author(s):

Rebecca Creamer ◽

Deana Baucom Hille ◽

Marwa Neyaz ◽

Tesneem Nusayr ◽

Christopher L. Schardl ◽

...

Keyword(s):

Amino Acid ◽

Polyketide Synthase ◽

Genetic Relationships ◽

Protein Sequences ◽

Fungal Endophyte ◽

Melanin Synthesis ◽

Melanin Biosynthesis ◽

Protein Levels ◽

Oxytropis Sericea ◽

And Function

The legume Oxytropis sericea hosts a fungal endophyte, Alternaria oxytropis, which produces secondary metabolites (SM), including the toxin swainsonine. Polyketide synthase (PKS) and non-ribosomal peptide synthase (NRPS) enzymes are associated with biosynthesis of fungal SM. To better understand the origins of the SM, an unannotated genome of A. oxytropis was assessed for protein sequences similar to known PKS and NRPS enzymes of fungi. Contigs exhibiting identity with known genes were analyzed at nucleotide and protein levels using available databases. Software were used to identify PKS and NRPS domains and predict identity and function. Confirmation of sequence for selected gene sequences was accomplished using PCR. Thirteen PKS, 5 NRPS, and 4 PKS-NRPS hybrids were identified and characterized with functions including swainsonine and melanin biosynthesis. Phylogenetic relationships among closest amino acid matches with Alternaria spp. were identified for seven highly conserved PKS and NRPS, including melanin synthesis. Three PKS and NRPS were most closely related to other fungi within the Pleosporaceae family, while five PKS and PKS-NRPS were closely related to fungi in the Pleosporales order. However, seven PKS and PKS-NRPS showed no identity with fungi in the Pleosporales or the class Dothideomycetes, suggesting a different evolutionary origin for those genes.

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