Tanning activators are chemicals that increase the effect of

UV-radiation Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of the ...

on the

human skin The human skin is the outer covering of the body and is the largest organ of the integumentary system. The skin has up to seven layers of ectodermal tissue (biology), tissue guarding Skeletal muscle, muscles, bones, ligaments and organ (anato ...

Overview

Since

sunburn Sunburn is a form of radiation burn that affects living tissue, such as skin, that results from an overexposure to ultraviolet (UV) radiation, usually from the Sun. Common symptoms in humans and other animals include red or reddish skin tha ...

and suntan are induced by the same mechanism (

direct DNA damage Direct may refer to: Mathematics * Directed set, in order theory * Direct limit of (pre), sheaves * Direct sum of modules, a construction in abstract algebra which combines several vector spaces Computing * Direct access (disambiguation), a ...

), these substances increase the likelihood for sunburn as well. The best known tanning activator is

psoralen Psoralen (also called psoralene) is the parent compound in a family of naturally occurring organic compounds known as the linear furanocoumarins. It is structurally related to coumarin by the addition of a fused furan ring, and may be considered a ...

which is an ingredient of bergamot oil. Psoralen has been present in

sunscreen Sunscreen, also known as sunblock, sun lotion or sun cream, is a photoprotection, photoprotective topical product for the Human skin, skin that helps protect against sunburn and prevent skin cancer. Sunscreens come as lotions, sprays, gels, fo ...

s in order to allow suntanning despite the reduced UV-intensity that acts on the deeper layers of the skin. In

Switzerland Switzerland, officially the Swiss Confederation, is a landlocked country located in west-central Europe. It is bordered by Italy to the south, France to the west, Germany to the north, and Austria and Liechtenstein to the east. Switzerland ...

, a ban was imposed on psoralen containing sunscreens in 1987 but it was loosely enforced for several years. In other countries these substances have been present in sunscreens until the first epidemiological results have shown that users have a fourfold risk of developing melanoma. They were finally banned in 1996. This happened more than 15 years after the photocarcinogenic potential of psoralen had been demonstrated. After the evidence for the photocarcinogenic potential of psoralen emerged, sunscreens which combined UVB filters and psoralen were introduced onto the market. These products were accompanied by campaigns to convince the public and the regulatory authorities that these products were safe or even better than usual sunscreens. These sunscreens were especially recommended to poor tanners. Psoralen tanning lotions were available in

France France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...

Belgium Belgium, officially the Kingdom of Belgium, is a country in Northwestern Europe. Situated in a coastal lowland region known as the Low Countries, it is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeas ...

and

Greece Greece, officially the Hellenic Republic, is a country in Southeast Europe. Located on the southern tip of the Balkan peninsula, it shares land borders with Albania to the northwest, North Macedonia and Bulgaria to the north, and Turkey to th ...

Mechanism of tanning activators

The increased production of melanin is the reaction of the skin to UVB-induced

. Several substances are known to increase the amount of direct DNA damage (

thymine dimers Pyrimidine dimers represent molecular lesions originating from thymine or cytosine bases within DNA, resulting from photochemical reactions. These lesions, commonly linked to direct DNA damage, are induced by ultraviolet light (UV), particularly ...

). In order to produce this action they have to penetrate into the skin, and this is in contrast to the assumptions which are made by those who endorse sunscreen use (see sunscreen controversy). The tanning activator

coumarin Coumarin () or 2''H''-chromen-2-one is an aromatic organic chemical compound with formula . Its molecule can be described as a benzene molecule with two adjacent hydrogen atoms replaced by an unsaturated lactone ring , forming a second six-me ...

is known to induce thymine dimers (cyclobutane pyrimidine dimers).{{cite journal , author=B. M. Hausen , author2=M. Schmieder , title=The sensitizing capacity of coumarins (I) , journal=Contact Dermatitis , volume=15 , issue=3 , pages=157–163 , year=1986 , pmid= 3780217, doi=10.1111/j.1600-0536.1986.tb01317.x Other Web sites state correctly that: "Coumarins produce photosensitivity therefore advise the patient to avoid direct sunlight after treatment

References

Sun tanning

Overview

Mechanism of tanning activators

See also

References