background and objectives: dried pulps and peels of ziziphus jujuba fruits are commonly applied as food because of their high nutritional value. it has been widely used in traditional medicine as laxative, tonic, wound healing agent and appetizer. the aim of this study was to evaluate the anti-melanogenic effects of z. jujuba fruit. methods: fruit extracts were obtained by two different extract...

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...

BACKGROUND Adenosine is a nucleoside, in which an adenine molecule is attached to a ribofuranose sugar moiety. It can be released into the microenvironment by metabolically active cells, and then fulfills a multitude of functions in regulation of cell proliferation, by activating four subtypes of G protein-coupled adenosine receptors. OBJECTIVE In this study, we investigated the effect of ade...

Overproduction and stimulation of tyrosinase result in increased melanogenesis of which several skin disorders such as freckles, spots, and hyperpigmentation appear as complications. Limonium tetragonum is a halophyte well-known for its antioxidative properties. This study investigated the anti-melanogenic effects of solvent-partitioned L. tetragonum extracts (LTEs) and its bioactive constituen...

BACKGROUND Melan-A and tyrosinase are new immunohistochemical markers that can be used in the diagnosis of melanocytic lesions. The aim of this study was to investigate the correlation between radiotherapy or clinicohistopathological parameters and the expression of melan-A and tyrosinase in uveal melanoma. METHODS Thirty-six enucleated cases of uveal melanoma were studied. The formalin-fixed...

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...

The morphological basis of glomerular filtration and protein reabsorption in mouse kidney was examined by using mushroom tyrosinase subunits (mol wt 34,500), as an ultrastructural tracer. Almost immediately after injection tyrosinase reaction product was visualized in the glomerulus, and within the capillary lumen extending into the endothelial fenestrae. The entire basement membrane showed acc...

The catalytic oxidation of catechol by crude preparations of mushroom tyrosinase was studied by a method yielding data on initial reaction velocities. Graphical analysis of the results suggests that an excess of catechol inhibits its own oxidation by a competitive process, thus accounting for the observed optimum in the substrate concentration. However, added phenol, though itself a substrate, ...

Arbutin và axit kojic được biết đến là chất ức chế tyrosinase thường sử dụng trong mỹ phẩm sản làm trắng da. Tuy nhiên, gây ra nhạy cảm da, khi arbutin có khả năng độc tế bào. Do đó, việc tìm nguồn gốc thiên nhiên đang rất quan tâm. Nghiên cứu này nhằm đánh giá tác động enzyme của các cao chiết từ lá nho Vitis vinifera L.. Cao toàn phần bằng phương pháp ngâm với chloroform, cồn 96o nước. Tác th...

tyrosinase is a multifunctional copper-containing enzyme. it can catalyze two distinct reactions of melanin synthesis and benzaldehyde derivatives, which are potential tyrosinase inhibitors.  to find the relationships between charge distributions of benzaldehyde and their pharmaceutical behavior, the present study aimed at investigating nuclear quadrupole coupling constants of quadrupolare nucl...