Tanning activator
Encyclopedia
Tanning activators are chemicals that increase the effect of UV-radiation on the human skin
.
and suntan
are induced by the same mechanism (direct DNA damage
), these substances increase the likelihood for sunburn as well. The best known tanning activator is psoralen
which is an ingredient of bergamot oil. Psoralen has been present in sunscreen
s in order to allow suntanning despite the reduced UV-intensity that acts on the deeper layers of the skin. In 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 photocarcinogen
ic 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
, Belgium
and Greece
.
. Several substances are known to increase the amount of direct DNA damage (thymine dimers). 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
is known to induce thymine dimers (cyclobutane pyrimidine dimers).
Other Web sites state correctly that: "Coumarins produce photosensitivity therefore advise the patient to avoid direct sunlight after treatment. http://www.aromacaring.co.uk/oedema.htm
Human skin
The human skin is the outer covering of the body. In humans, it is the largest organ of the integumentary system. The skin has multiple layers of ectodermal tissue and guards the underlying muscles, bones, ligaments and internal organs. Human skin is similar to that of most other mammals,...
.
Overview
Since sunburnSunburn
A sunburn is a burn to living tissue, such as skin, which is produced by overexposure to ultraviolet radiation, commonly from the sun's rays. Usual mild symptoms in humans and other animals include red or reddish skin that is hot to the touch, general fatigue, and mild dizziness. An excess of UV...
and suntan
Sun tanning
Sun tanning or simply tanning is the process whereby skin color is darkened or tanned. The process is most often a result of exposure to ultraviolet radiation from the sun or from artificial sources, such as a tanning bed, but can also be a result of windburn or reflected light...
are induced by the same mechanism (direct DNA damage
Direct DNA damage
Direct DNA damage can occur when DNA directly absorbs the UV-B-photon. UVB light causes thymine base pairs next to each other in genetic sequences to bond together into thymine dimers, a disruption in the strand, which reproductive enzymes cannot copy...
), these substances increase the likelihood for sunburn as well. The best known tanning activator is psoralen
Psoralen
Psoralen is the parent compound in a family of natural products known as furocoumarins. It is structurally related to coumarin by the addition of a fused furan ring, and may be considered as a derivative of umbelliferone...
which is an ingredient of bergamot oil. Psoralen has been present in sunscreen
Sunscreen controversy
Sunscreen protects against two common forms of skin cancer, squamous cell carcinoma and basal cell carcinoma , and several sunscreen ingredients protect against tumor development in photocarcinogenicity tests in mice...
s in order to allow suntanning despite the reduced UV-intensity that acts on the deeper layers of the skin. In Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
, 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 photocarcinogen
Photocarcinogen
A photocarcinogen is a substance which causes cancer following illumination. This destructive effect often results from free radicals generated by the photocarcinogen. Many chemicals that are not carcinogenic can be photocarcinogenic...
ic 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
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
, Belgium
Belgium
Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...
and Greece
Greece
Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....
.
Mechanism of tanning activators
The increased production of melanin is the reaction of the skin to UVB-induced direct DNA damageDirect DNA damage
Direct DNA damage can occur when DNA directly absorbs the UV-B-photon. UVB light causes thymine base pairs next to each other in genetic sequences to bond together into thymine dimers, a disruption in the strand, which reproductive enzymes cannot copy...
. Several substances are known to increase the amount of direct DNA damage (thymine dimers). 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
Sunscreen controversy
Sunscreen protects against two common forms of skin cancer, squamous cell carcinoma and basal cell carcinoma , and several sunscreen ingredients protect against tumor development in photocarcinogenicity tests in mice...
).
The tanning activator coumarin
Coumarin
Coumarin is a fragrant chemical compound in the benzopyrone chemical class, found in many plants, notably in high concentration in the tonka bean , vanilla grass , sweet woodruff , mullein , sweet grass , cassia cinnamon and sweet clover...
is known to induce thymine dimers (cyclobutane pyrimidine dimers).
Other Web sites state correctly that: "Coumarins produce photosensitivity therefore advise the patient to avoid direct sunlight after treatment. http://www.aromacaring.co.uk/oedema.htm