Sunbathers beware! Skin damage continues hours after sun exposure.

The unusual chemical properties of melanin mean that although it is a good UV absorber, it is also susceptible to other chemical reactions that have the same impact as the UV. Melanin may thus be carcinogenic as well as protective against skin cancer. Researchers exposed human and mouse pigment cells (melanocytes) to radiation from a UV lamp. Although the cells experienced immediate DNA damage, this continued for hours. In fact, half of the damage occurred in the hours following exposure. Free radicals generated by UV light caused delayed damage to DNA with the aid of compounds derived from melanin. This melanin-assisted process creates compounds known as cyclobutane pyrimidine dimers in DNA, which can lead to mutations that cause melanoma, a potentially deadly skin cancer. These changes are identical to the well-known genetic alterations caused directly by UV light, but at least half of the dimers appear well after your trip to the beach. However, there is some good news. Researchers say it may be possible to develop sunscreens that protect against this type of damage. But we’re not there yet……… Reference: Science 2015;34:842-847. Chemiexcitation of melanin derivatives induces DNA photoproducts long after UV exposure. Premi S, Wallisch S et al.

Sunbathers beware! Skin damage continues hours after sun exposure.

The unusual chemical properties of melanin mean that although it is a good UV absorber, it is also susceptible to other chemical reactions that have the same impact as the UV. Melanin may thus be carcinogenic as well as protective against skin cancer.

Researchers exposed human and mouse pigment cells (melanocytes) to radiation from a UV lamp. Although the cells experienced immediate DNA damage, this continued for hours. In fact, half of the damage occurred in the hours following exposure.

Free radicals generated by UV light caused delayed damage to DNA with the aid of compounds derived from melanin. This melanin-assisted process creates compounds known as cyclobutane pyrimidine dimers in DNA, which can lead to mutations that cause melanoma, a potentially deadly skin cancer. These changes are identical to the well-known genetic alterations caused directly by UV light, but at least half of the dimers appear well after your trip to the beach.

However, there is some good news. Researchers say it may be possible to develop sunscreens that protect against this type of damage. But we’re not there yet………

Reference: Science 2015;34:842-847. Chemiexcitation of melanin derivatives induces DNA photoproducts long after UV exposure. Premi S, Wallisch S et al.