.Melanin is a kind of polymeric bio-pigment. This pigment, which is very important to humans, can determine the color of both hair and skin.
The melanin in the human body is formed in several steps. First, tyrosinase reacts with tyrosine to form dopa, which will become dopaquinone after hydrogen is removed. Next, the dopaquinone is reorganized in a form of 5,6-quinone indolo whose polymer can combine with structural proteins to form the melanin.
Melanin can be divided into two kinds: eumelanin and pheomelanin. Eumelanin is an insoluble polymer that is brown in color. It can endure various chemical treatments. Pheomelanin, which is red or yellow, can be dissolved in alkaline liquids. It is found in red or golden hair.
The color of human hair is decided by the quality and quantity of melanin produced from melanin cells in hair follicles. The melanin in the epidermis can absorb most UV light and diminish the penetrability of UVA and UVB rays. So it can protect the dermis from sunburn and alleviate acute or chronic skin damage.
Interest in promoting melanin biosynthesis by active substances from Chinese medicinal plant materials is at the forefront of research on facial and hair cosmetics in the 21st century. Melanin can modify our appearance and it can be used as an agent that will prevent sunburn and blacken hair. This research will be good news to the people who need sunburn protection and hair darkening.
We extracted several Chinese medicinal plant materials and studied their ability at selected concentrations to upregulate melanin biosynthesis. The term “up-regulate” means to increase the regulation and control of a biological process, which is melanin biosynthesis in this case. To estimate the quantity of melanin synthesized, we used an in vitro technique based on the melanin’s absorbance of UV light.