Objective(s):Involvement of tyrosinase in the synthesis of melanin and cell signaling pathway has made it an attractive target in the search for therapeutic inhibitors for treatment of different skin hyperpigmentation disorders and melanoma cancers. Materials and Methods: In the present study, we conducted a comprehensive kinetic analysis to understand the mechanisms of inhibition imposed by 2-...

This study reports depigmenting potency of 1,3-selenazol-4-one derivatives, which would be based upon the finding of direct inhibition to mushroom tyrosinase. 1,3-Selenazol-4-one derivatives exhibited inhibitory effect on dopa oxidase activity of mushroom tyrosinase. In this study, inhibitory effects of six kinds of 1,3-selenazol-4-one derivatives (A, B, C, D, E and F) on mushroom tyrosinase we...

The aim of this study was to evaluate complexes of L-ascorbyl palmitate (ASCP) and urea (UR). This evaluation involved differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), near-infrared spectroscopy (NIR), a solubility test, a 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging test, and a mushroom tyrosinase inhibition assay. Physico...

Nowadays herbal medicines of skin-whitening cosmetics are popular with women. We attempted to find the whitening activity compounds present in many herbal medicines used for this purpose and discuss their mechanisms in melanin biosynthesis. The 70% acetone extracts of 10 kinds of herbs were investigated for their mushroom tyrosinase activity inhibition. Among these 10 extracts, Chinese galls sh...

Objective(s): Nepeta binaludensis Jamzad (Lamiaceae) has been used in folk medicine of Iran to cure various diseases. The plant is an endemic species to the country that has recently been identified in Razavi Khorasan province. To evaluate the antioxidant and anti-melanogenesis of N. binaludensis, in this study the inhibitory activity of different extracts of N. binaludensis in murine melanoma ...

Cutaneous hyperpigmentation is a common disorder due to excess melanin production by the enzyme tyrosinase. The gold standard for treatment is hydroquinone (HQ), which reduces pigmentation through its toxicity to melanocytes rather than via tyrosinase inhibition. We screened an internal library for oligopeptides that inhibited both mushroom and human tyrosinase but showed no cytotoxicity to hum...

Methimazole (1-methyl-2-mercaptoimidazole) inhibits both the mono- and the o-dihydroxyphenolase activities of mushroom tyrosinase when assayed spectrophotometrically. With DL-3,4-dihydroxyphenylalanine as substrate, the inhibition was found to be a mixed-type one with Ki 4.6 X 10(-6) M. We found that methimazole can interact with the oxidation products of o-dihydroxyphenols, probably with o-qui...

Tyrosinase is involved in melanin biosynthesis and the abnormal accumulation of melanin pigments leading to hyperpigmentation disorders that can be treated with depigmenting agents. A natural product T1, bis(4-hydroxybenzyl)sulfide, isolated from the Chinese herbal plant, Gastrodia elata, is a strong competitive inhibitor against mushroom tyrosinase (IC50 = 0.53 μM, Ki = 58 ± 6 nM), outperforms...

To identify novel inhibitors of tyrosinase, a fluorescent assay was developed which is suitable for high-throughput screening. In the assay, oxidation of the substrate by tyrosinase leads to the release of a fluorescent coumarin. Several small molecules were identified that inhibited mushroom tyrosinase in vitro and human tyrosinase in cell culture. These compounds may represent lead structures...

N-Hydroxycinnamoylphenalkylamides (36H) exhibited both antioxidation and antityrosinase abilities. The compound was studied for its antioxidative properties, using a 1,1-diphenyl-2-picrylhydrazul- (DPPH-) scavenging test, a ferric ion-reducing antioxidant power assay (FRAP) assessment, and a metal-chelating power assay. The results showed that 36H had antioxidative capabilities in the DPPH-scav...