Formation of Melanin

Human body contain more than 500 thousand billion cells, each day these cells divide and form 10 billion cells.
10-20 billion of melanin cells at the basal layer. An average of 1,560 per mm, as well as scatter in the epidermis, follicle, choroid of the eye, etc.

Melanin cells will follow the Keratin to the epidermis and will be discharge due to metabolism.
When melanin failed to excrete out, it accumulate within the epidermis tissue, causing skin to thicken, hence resulting to coloration to darken.

The activity of the tyrosinase is evaluated by the intensity of the colorimetric response obtained; inhibition of this activity is revealed by the absence of the colorimetric reaction (right).