UV rays and environmental pollutants trigger the formation of free radicals in the body, especially the skin. These free radicals have one unpaired electron, which makes them very unstable. They steal an electron from your body’s healthy molecules, like DNA, which causes damage.
Collagen is responsible for keeping skin youthful by making it strong and robust. It’s produced in the body from collagen precursors, or pre-collagen. UV irradiation can block collagen production, decreasing the collagen content in the skin.
In addition, matrix-degrading metallo-proteinases (MMPs - enzymes that degrade proteins in tissue extracellular matrices) are responsible for breaking down collagen in the skin. They’re made in the epidermis, are regulated by UV rays. MMPs travel from the epidermis to the dermis to breakdown collagen. UV irradiation increases the amount of MMPs in the skin, causing an increase in the breakdown of collagen.
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