benzofurans and kojic-acid

Topics: Acarbose; Agaricales; Benzofurans; Binding Sites; Cholinesterase Inhibitors; Galantamine; Glycoside Hydrolase Inhibitors; Kinetics; Lignans; Molecular Docking Simulation; Monophenol Monooxygenase; Protein Binding; Pyrones

The phytochemical profiles of Morus australis roots, stems and twigs were firstly compared by HPLC analysis. It was found that Morus australis stem extract mainly contained one known tyrosinase inhibitor, oxyresveratrol, while its root and twig extract might contain some unknown potential tyrosinase inhibitors. The root extract of Morus australis was further investigated in this study. One new compound, austraone A, together with 21 known compounds, was isolated and their structures were identified by interpretation of MS and NMR data. In the tyrosinase inhibitory testing, some of them, such as oxyresveratrol, moracenin D, sanggenon T, and kuwanon O, exhibited stronger tyrosinase inhibitory activities than that of kojic acid. These results suggested the Morus australis root extract as a good source of natural tyrosinase inhibitors with a great potential to be used in foods as anti-browning agents and in cosmetics as skin-whitening agents.

Topics: Agaricales; Benzofurans; Chromatography, High Pressure Liquid; Enzyme Inhibitors; Heterocyclic Compounds, 4 or More Rings; Molecular Structure; Monophenol Monooxygenase; Morus; Phenols; Plant Extracts; Plant Roots; Plant Stems; Pyrones; Resveratrol; Stilbenes

Normal human melanocytes were amplified and cultured in a new defined culture medium without phorbol esters or cholera toxin. The medium decreased considerably the doubling time and increased the possible passage number. Melanocytes were co-seeded with normal human keratinocytes into 24 well culture dishes to screen potentially active modulators of melanogenesis. For the assay, the co-cultures were exposed to the compounds under investigation in the presence of 14C-thiouracil and 3H-leucine. Control cultures contain L-tyrosine or kojic acid, modulators which served as internal calibration standards. Changes in the rate of melanin synthesis were measured on the basis of 14C-thiouracil incorporation into newly synthesized melanin. A reduction or increase in 3H-leucine incorporation was taken as an indication of cytotoxicity or induction of proliferation, respectively. The NHK-NHM co-culture screening assay provides a useful tool to compare the activity of known modulators of melanogenesis and to perform structure-activity studies with newly identified modulators to improve their activity. The efficacy of particularly interesting new compounds was further evaluated on reconstructed pigmented epidermis after repeated topical application. The same model was used to assess the anti-pigmenting effect of sunscreens on UV-induced pigmentation. Integration of melanocytes from different ethnic origin resulted in pigmented epidermis reflecting different skin phenotypes, Caucasian, Asian and African.

Topics: 1-Methyl-3-isobutylxanthine; 3T3 Cells; Animals; Arbutin; Asian People; Benzofurans; Black People; Cells, Cultured; Coculture Techniques; Culture Media; Epidermal Cells; Ethnicity; Humans; Hydroquinones; Hydroxybenzoates; Indoles; Keratinocytes; Melanins; Melanocytes; Mice; Phenotype; Pyrones; Skin Pigmentation; Skin, Artificial; Theophylline; Thiophenes; Ultraviolet Rays; White People