This is an automatically translated article.
Melanin is a protective pigment in the skin that blocks UV radiation from damaging DNA and potentially causing skin cancer. Melanin protects our skin, but some studies suggest it can also be harmful.
1. What is Melanin?
UVA radiation causes damage or DNA damage to melanocytes, which are the skin cells that produce the skin pigment known as melanin. Melanin is a protective pigment in the skin that blocks UV radiation from damaging DNA and potentially causing skin cancer. Melanin protects the skin but also damages the skin. Melanin is the pigment that determines the color of each person's skin, produced from skin cells called melanocytes (melanocytes), which are distributed in the basal layer of the epidermis. Melanocytes contain the enzyme Tyrosinase.
The formation of melanin is by the action of the enzyme Tyrosinase and also by environmental agents mainly due to ultraviolet rays in the sun. In addition, factors such as hormones and nerves also contribute to the formation of melanin.
Dark brown to black eumelanin and reddish brown Pheomelanin are the two main forms of the pigment Melanin. Different ratios of these molecules cause different types of skin color in the human body.
Eumelanin exists most in people with dark skin. Eumelanin gives brown and black pigment to skin, hair and eyes. Therefore, as we age, the melanin content is now produced less and less, the hair begins to turn gray.
Melanin là sắc tố trong da ngăn chặn bức xạ UV gây tổn hại DNA
2. How does Melanin cause skin damage?
Researchers say UV radiation produces reactive oxygen and nitrogen that powers an electron present in melanin.
That energy can cause DNA damage, which can lead to cancer-causing mutations. Lesions usually appear one second after exposure to radiation from UV rays.
However, the researchers also note that severe damage can also occur more than three hours after exposure to radiation from UVA rays, after you are exposed to direct sunlight or exposed to sunlight. sunny. Melanin protects you, and melanin can also harm you.
Experts say that melanin protects us and sunlight is trying to damage the cells in our body. As a result, melanin can cause cancer as well as protect the body against cancer.
The study was performed on mouse and human melanocyte cells exposed to UV radiation using a UV lamp. This has resulted in cyclobutane pyrimidine dimers (CPDs), a form of DNA damage.
The melanocytes produce CPD immediately and continue to do so several hours after the UV exposure ends. Melanin-free cells produce CPD but only during exposure to UV radiation. Melanin as a shield helps protect against CPD.
Next, the scientists looked at the damage after sun exposure. They found that half of the CPDs in melanocytes were produced in the dark.
Da tiếp xúc quá lâu dưới ánh mặt trời làm xuất hiện các vết nám
Another researcher learned that UV light activated two enzymes that work together to stimulate melanin. That energy, called valence, is transferred to DNA in the dark. It produces the same amount of DNA damage that sunlight does during the day.
Melanin is also considered the main cause of the formation of dark spots on the skin color. The excessive amount of melanin when exposed for too long under sunlight and even after not being exposed to ultraviolet rays anymore, the amount of melanin produced also becomes excess leading to melasma, darkening of the skin. skin.
3. How does Melanin protect the skin?
Melanin plays an extremely important role in the skin. Not only helps to resist heat effects from the outside like the sun, but melanin also helps balance body temperature and helps fight bacteria. The body resists ultraviolet radiation thanks to the presence of melanin. Therefore, Melanin helps to fight the oxidation of the skin. However, overproduction of melanin can lead to skin pigmentation.
Therefore, Melanin is considered as a "double-edged sword". They both protect the natural skin, and are the culprits that cause the skin to become dark.
Tăng sinh Melanin quá mức sẽ khiến da trở nên sạm nám
It is important to note that humans cannot determine the amount of melanin. Genetics, vitamin D and UV exposure are the three main factors that directly affect melanin content. Many studies also prove that if the body lacks melanin for a long time, it can cause death, which is caused by vitamin D deficiency.
Apply sunscreen when exposed to UV rays, it can prevent the risk of sun damage. However, after we leave the beach or stop sunbathing, it is still possible to cause this harmful reaction to melanin.
Currently, experts are looking for a way to create a product that can stop the reaction. Because melanin can both protect us and can damage our bodies, you need to be very careful when exposed to ultraviolet rays. According to experts, you should not be in the sun between 10 am and 2 pm.
Customers can directly go to Vinmec Health system nationwide to visit or contact the hotline here for support.
Articles refer to the source: healthline.com
