We examined the ability of oxidation products of dopamine, DOPA, and 3,4-dihydroxyphenylacetic acid (DOPAC) to inhibit proteasomal activity. Dopamine, DOPA, and DOPAC underwent tyrosinase-catalyzed oxidation to generate aminochrome, dopachrome, and furanoquinone, respectively. In these studies, the oxidation of dopamine by tyrosinase generated product(s) that inhibited the proteasome, and prote...

ETHNOPHARMACOLOGICAL RELEVANCE Sargassum polycystum, a type of brown seaweed, has been used for the treatment of skin-related disorders in traditional medicine. AIM OF THE STUDY The aim of the present study is to investigate the antimelanogenesis effect of Sargassum polycystum extracts by cell-free mushroom tyrosinase assay followed by cell viability assay, cellular tyrosinase assay and melan...

Ten fatty acid alkyl esters isolated from Oxalis triangularis, were evaluated for the effects on melanogenesis using mouse B16 melanoma cells. Treatment of methyl linoleate, methyl linolenate, ethyl linoleate and ethyl linolenate significantly blocked forskolin-induced melanogenesis and inhibited tyrosinase activity. In addition, we found that they inhibited cAMP production, suggesting that the...

Four known compounds have been isolated from the stems of Liriodendron tulipifera, and the structures of these pure constituents were determined using spectroscopic analysis. Isolated compounds were screened for free radical scavenging ability, metal chelating power assay and ferric reducing antioxidant power assay (FRAP). The anti-tyrosinase effects of L. tulipifera compounds were calculated t...

Objective: Tyrosinase as the key enzyme in melanin biosynthesis, involves in determining the color of mammalian skin and hair. A variety of dermatological disorders, come up from an unnecessary level of epidermal pigmentation. Plants are low-cost and rich sources of active compounds.  Methods: More than seventy native plants collected from the central region of Kurdistan province collected. Inh...

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 activi...

Tyrosinase is the key enzyme involved in melanogenesis. The aim of this study was to investigate the in vitro inhibitory effects of gnetin C, a resveratrol dimer isolated from melinjo (Gnetum gnemon) seeds, on tyrosinase activity and melanin biosynthesis in murine B16 cells. The inhibitory activities of gnetin C and resveratrol were shown to be almost equal against tyrosinase and melanin biosyn...

Tyrosinase is an enzyme of industrial interest. The production and characterization of tyrosinase from P. sanguineus CCT-4518 were investigated. The selection of inductors, luminosity influence, inoculum size and type of culture medium on the production of tyrosinase and the effect of inhibitors on enzyme activity were performed. Optimum conditions for intracellular tyrosinase production was ob...

PURPOSE The aim of this study was to investigate acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and antityrosinase activities of extracts from ten Piper species namely; P. caninum, P. lanatum, P. abbreviatum, P. aborescens, P. porphyrophyllum, P. erecticaule, P. ribesioides, P. miniatum, P. stylosum, and P. majusculum. METHODS Anticholinesterase and antityrosinase activities were e...

Melanin protects the skin against UV damage, whereas excessive melanin accumulation causes abnormal pigmentation and even melanoma. It has been reported that Rosa rugosa exhibits antioxidant, anti-bacterial, anti-tumor, anti-inflammation activities. The current study evaluated melanogenesis-suppressing effect of R. extract its solvent fractions (H2O, n-BuOH, 85% aq. MeOH, n-hexane). on extra/in...