Melanin is a natural pigment that is responsible for the coloring of skin, hair and eyes in humans and animals. It is produced in specialized cells called melanocytes, which are found in the lower layer of the epidermis (upper skin), in hair follicles and in the iris of the eyes. Melanin plays a crucial role in protecting the skin from the harmful effects of ultraviolet (UV) radiation. By absorbing UV rays, melanin helps prevent DNA damage, which can lead to skin cancer.
Types of melanin
There are mainly two types of melanin:
- Eumelanin : This pigment varies from brown to black and is responsible for the darker coloring of skin, hair and eyes. A higher concentration of eumelanin provides better protection against UV rays.
- Pheomelanin : This pigment is red to yellow in color and is present in higher concentrations in people with fair skin, red hair, and freckles. Pheomelanin offers less protection against UV rays than eumelanin.
Functions of melanin
- UV protection : Melanin absorbs and disperses UV rays, protecting the skin from UV-related damage.
- Thermoregulation : Melanin can help regulate body temperature, especially in sunny environments.
- Visual acuity : Melanin in the iris regulates the amount of light entering the eye and contributes to the sharpness of vision.
Melanin and health
- Skin cancer risk : People with fair skin and lower melanin concentrations are at higher risk of skin cancers such as melanoma because their skin is less protected.
- Vitamin D synthesis : Melanin affects the skin's ability to synthesize vitamin D High concentrations of melanin can slow vitamin D production, which in some cases can lead to vitamin D deficiency.
- Pigmentation disorders : Conditions such as vitiligo, albinism and melasma are due to changes in melanin production and affect the appearance of the skin.
Melanin in cosmetics and therapy
- Skin care : Products aimed at regulating melanin production are often used to treat pigmentary disorders such as hyperpigmentation and age spots.
- Hair dyes : Changing the natural hair color through dyeing visually influences the melanin concentration in the hair.
Research into melanin and its functions provides valuable insights into the fields of dermatology, endocrinology and cosmetology, and helps in the development of protective measures against skin cancer and in the treatment of pigment disorders.
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