Many skin-whitening compounds target tyrosinase because it catalyzes two rate-limiting steps in melanin synthesis. Although many tyrosinase inhibitors are currently available for a skin-whitening purpose, undesirable adverse effects are also reported. Thus, numerous efforts have been made to develop safer tyrosinase inhibitors from natural products. In line with this, we tested fifty flavonoids...

The effects of prostaglandins (PCs) on the ( loudman S91 melanoma CCL 53.1 cell line indicate that melanogenesis and proliferation are regulated by separate mechanisms that are not necessarily cyclic AMP (cAMP) dependent. These cells responded to PGEi and PGE2 in a dosedependent manner, by an increase of tyrosinase activity and by inhibition of proliferation. PGAi and PGD2 inhibited cellular pr...

The effects of prostaglandins (PGs) on the Cloudman S91 melanoma CCL 53.1 cell line indicate that melanogenesis and proliferation are regulated by separate mechanisms that are not necessarily cyclic AMP (cAMP) dependent. These cells responded to PGE1 and PGE2 in a dose-dependent manner, by an increase of tyrosinase activity and by inhibition of proliferation. PGA1 and PGD2 inhibited cellular pr...

Long-term treatment with minocycline is known to induce pigmentation or discoloration in tissues but how remains unclear. We investigated the mechanism of pigmentation using B16 melanoma cells. First, we confirmed that intracellular melanin levels increased on minocycline treatment. Then, using the reverse transcriptase-polymerase chain reaction (RT-PCR), we found the expression of mRNA of tyro...

The tyrosinase inhibitory activity of the extracts of 53 parts of 36 plant species cultivated for edible and medicinal use in Okinawa was investigated. The extract of Nandina domestica showed potent activity among these. The inhibitor in the extract was purified by assay-guided fractionation to give a simple phenol glucoside. Although it was a known compound (4-beta-D-glucopyranosyloxybenzoic a...

Geoditin A, an isomalabaricane triterpene isolated from marine sponge Geodia japonica, has been demonstrated to induce apoptosis in leukemia HL60 cells and human colon HT29 cancer cells through an oxidative stress, a process also interfering with normal melanogenesis in pigment cells. Treatment of murine melanoma B16 cells with geoditin A decreased expression of melanogenic proteins and cell me...

Phosvitin is a phosphoglycoprotein present in egg yolk. More than half of the amino acids in phosvitin molecule are serine, of which >90% are phosphorylated. Therefore, phosvitin has a strong metal binding capability. The aim of this study was to investigate the effect of phosvitin on the inhibition of melanogenesis in melanoma cells. The results showed that phosvitin inhibited the activity of ...

The inhibition of tyrosinase is the most effective method to decrease melanin synthesis during the process of pigmentation. We aimed to find compounds from traditional Chinese medicines (TCM) that are more effective than the most commonly used tyrosinase inhibitor, arbutin. First, we employed homology modeling to construct a tyrosinase-modeled structure, and structure-based virtual screening to...

Smyrnium connatum Boiss. and Kotschy is known as “yabani kereviz” in Turkey its roots are used to treat asthma. species by people different regions diuretic, depurative laxative. The aim of this analysis was test the biological activities methanol extracts obtained from aerial parts S. using a Soxhlet extractor, ultrasonic assisted extraction, maceration procedures. were tested for their acetyl...

The effects of various inhibitors on crude, commercial and partially purified commercial mushroom tyrosinase were examined by comparing IC(50) values. Kojic acid, salicylhydroxamic acid, tropolone, methimazole, and ammonium tetrathiomolybdate had relatively similar IC(50) values for the crude, commercial and partially purified enzyme. 4-Hexylresorcinol seemed to have a somewhat higher IC(50) va...