Numerous sunscreens are available in the market today but most of them protect well only against UVB rays, leaving UVA protection limited. This is problematic because UVA rays penetrate deep into the skin, causing damage at the cellular level.
To address this issue, researchers have uncovered a compound that can be added to sunscreens that offers unexpectedly strong protection against UVA exposure, particularly within the cell where most of the damage related to UVA occurs.
Concentrations of free iron are highest within the mitochondria, the powerhouse of the cell. However, free iron turns into a catalyst for toxic reactive oxygen species when exposed to UVA, facilitating damage to cellular components that lead to increased risks of cancer and cell death.
The custom-designed iron chelator called mitoiron claw that the researchers developed attaches to iron atoms like a claw (hence its name), safely binding excess free iron and keeping them from reacting once exposed to UVA rays.
The researchers carried out tests involving human skin cells exposed to UVA at a rate equivalent to 140 minutes of uninterrupted sun exposure and saw that mitoiron claw-treated cells received complete protection against cell death.
"The role of iron-mediated damage induced upon exposure of skin cells to UVA has been underestimated for many years," said Charareh Pourzand, one of the authors of the study.
With the mitochondria-targeted compound, the researchers have come up with a solution to the problem of iron-induced damage, addressing an unmet need in the skincare industry.
Having demonstrated the mitoiron claw's protective effects, the researchers are looking into further exploring the compound's other benefits, including use in other therapies where mitochondrial iron overload is involved, such as in Friedreich's ataxia.
Their current study received funding support from the Biotechnology and Biological Sciences Research Council and was published in the Journal of Investigative Dermatology.
There is growing awareness regarding the importance of using sunscreen as protection against skin cancer, but many consumers are buying sunscreens that don't meet recommended guidelines set by the American Academy of Dermatology (AAD).
According to the AAD, sunscreens have to be water-resistant, should protect against both UVA and UVB rays and must have a sun protection factor of at least 30.
A study published earlier in July, however, has revealed that nearly 40 percent of the most popular sunscreens sold in Amazon.com fall short of AAD's criteria. Neutrogena and Eucerin, for instance, lack water resistance.
It is believed that about 9 percent of all sunscreen sales in the United States occur in the site.
Photo: Joe Shlabotnik | Flickr
