Anti-melanization effects and inhibitory kinetics of tyrosinase of bird's nest fern (Asplenium australasicum) frond extracts on melanoma and human skin.
This molecule is capable of constructing an efficient catalytic redox cycle with tyrosinase and NQO1 in melanoma B16F1 cells to induce selectively the ROS (mainly including hydrogen peroxide, H<sub>2</sub>O<sub>2</sub>) accumulation in the cells, resulting in highly selective suppression of melanoma B16F1 cells over tyrosinase-deficient HeLa and normal L-02 cells.
This work provides further evidence to support that dietary catechols exhibit antimelanoma activity by virtue of their tyrosinase-dependent pro-oxidative role and gives useful information for designing polyphenol-inspired GST inhibitors and sensitizers in chemotherapy against melanoma.
Tyrosinase (TYR) which can catalyze the oxidation of catechol is recognized as a significant biomarker of melanocytic lesions, thus developing powerful methods for the determination of TYR activity is highly desirable for the early diagnosis of melanin-related diseases, including melanoma.
Thereafter, increasing levels of TYR were recorded in cells that were collected from the skin of melanoma mouse models representing three different stages of tumor growth.
We carried out herein the screening of a family of cyclic Morita-Baylis-Hillman adducts (MBH) to find out their effects on tyrosinase activity and on melanogenesis in murine melanoma B16F10 cell line.
Melanoma is an aggressive malignant tumor that undergoes rapid growth and metastasis in a short time; tyrosinase (TYR) is an important biomarker for melanoma diagnosis as it is over-expressed in melanoma cells.
FEPS inhibited mushroom tyrosinase with the half maximal inhibitory concentration (IC<sub>50</sub>) of 16.5 mg/ml and dose-dependently inhibited cellular tyrosinase activity (63.9% at 50 μg/ml, and 83.3% at 100 μg/ml) in the cell-free extract of SK-MEL-5 human melanoma cell and α-melanocytestimulating hormone (α-MSH)-stimulated melanin formation in intact SK-MEL-5 human melanoma cell.
Tyrosinase, a copper-containing enzyme existing widely in plants, animals and microorganisms, usually serves as an important biomarker in melanoma, and is also related to hyperpigmentation of the skin, melasma, age spots and albinism.
In this study, a fluorescent probe called NBR-AP for detecting tyrosinase (a biomarker of melanoma) has been created by incorporating a hydroxyphenylurea group (as a substrate for the enzyme) onto a fluorescent dye phenoxazine derivative (as an activatable signal reporter).
A series of N-aryl-2-phenyl-hydrazinecarbothioamides have been investigated as possible inhibitors of tyrosinase, an enzyme involved in the development of melanomas.
Although radioiodine labeled 4-hydroxyphenylcysteamine, which we previously developed, has good affinity for tyrosinase, an enzyme in the melanin metabolic pathway, image contrast of the melanoma:organ ratios is not sufficiently high for detection of primary melanoma and metastases at early injection times.
The <i>in vivo</i> expression of multiple chimeric MHC class I receptors allows a simultaneous presentation of several melanoma-associated shared antigens tyrosinase related protein (TRP)-1, tyrosinase, human glycoprotein 100 and TRP-2.
Bioluminescence imaging results show that TYR-LH<sub>2</sub> is fully competent for monitoring the dynamic changes of TYR in living cells and model animals and possesses the capability of discriminating melanocytes from other cell lines, thus offering a promising approach for investigation and diagnosis of melanoma cancer and other TYR-related diseases in vivo.
In the search for compounds which may inhibit the development of melanomas, a series of thiosemicarbazones has been investigated as possible inhibitors of the tyrosinase enzyme.
Furthermore, the derivatives 3l and 3m showed cell selectivity with significant cytotoxic effects (IC<sub>50</sub> values of 46-65μM) against melanoma cell lines with tyrosinase overexpression MNT-1 and B16F10.
G protein-coupled estrogen receptor enhances melanogenesis via cAMP-protein kinase (PKA) by upregulating microphthalmia-related transcription factor-tyrosinase in melanoma.