On the other hand, inhibition of tyrosinase
(TYR, EC 1.
A: It takes 12-16 weeks in some cases to see the effects of tyrosinase
The binding of melanocyte-stimulating hormone to the melanocortin 1 receptor sets in motion melanogenesis by activating tyrosinase
Laccase and Tyrosinase
activity was induced 142% and 166 % respectively.
16 It inhibits melanin synthesis by inhibiting L-DOPA to interact with tyrosinase
in the process of melanin production.
Antioxidant (DPPH radical scavenging, reducing power (CUPRAC and FRAP), phosphomolybdenum and metal chelating (ferrozine method)) and enzyme inhibitory activities (cholinesterase (Elmann's method), tyrosinase
(dopachrome method), [alpha]-amylase (iodine/potassium iodide method) and [alpha]-glucosidase (chromogenic PNPG method)) determined by the method described by Zengin et al.
66,67] During melanogenesis, tyrosinase
is responsible for the conversion of L-tyrosine to L-DOPA and subsequently to dopaquinone, then the pathway bifurcates to produce eumelanin or phaeomelanin.
It inhibits tyrosinase
, the main pigment forming enzyme.
In the previous works, the leaf extract of mangosteen was found to stimulate melanin synthesis and enhance tyrosinase
activity  while its stem-bark extract showedcytotoxic activity against colon cancer cells .
4,5] have shown that cultured human melanocytes express oestrogen receptors and estradiol increases the levels of tyrosinase
-related-protein 1 and 2, the enzymes involved in human eumelanogenesis within normal human melanocytes.
Autoimmune hypothesis is the most widely accepted, because autoantibodies to melanocytes and tyrosinase
have been demonstrated and owing to the usual association of vitiligo with other autoimmune diseases.
Expression of tyrosinase
was revealed in some of these cells by dopa reaction.