Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sunscreens can damage skin

30.08.2006
Filters in sunscreens that keep out ultraviolet radiation can generate compounds that attack skin cells, say UCR chemists

Are sunscreens always beneficial, or can they be detrimental to users? A research team led by UC Riverside chemists reports that unless people out in the sun apply sunscreen often, the sunscreen itself can become harmful to the skin.

When skin is exposed to sunlight, ultraviolet radiation (UV) is absorbed by skin molecules that then can generate harmful compounds, called reactive oxygen species or ROS, which are highly reactive molecules that can cause "oxidative damage." For example, ROS can react with cellular components like cell walls, lipid membranes, mitochondria and DNA, leading to skin damage and increasing the visible signs of aging.

When sunscreen is applied on the skin, however, special molecules – called UV filters – contained in the sunscreen, cut down the amount of UV radiation that can penetrate the skin. Over time, though, these filters penetrate into the skin below the surface of the epidermis, the outermost layer of skin, leaving the body vulnerable to UV radiation.

... more about:
»ROS »Radiation »UV radiation »ultraviolet

Led by Kerry M. Hanson, a senior research scientist in the Department of Chemistry at UCR, the researchers report that three UV filters (octylmethoxycinnamate, benzophenone-3 and octocrylene), which are approved by the Food and Drug Administration and widely used in sunscreens, generate ROS in skin themselves when exposed to ultraviolet radiation, thus augmenting the ROS that is naturally produced. The researchers note that the additional ROS are generated only when the UV filters have penetrated into the skin and, at the same time, sunscreen has not been reapplied to prevent ultraviolet radiation from reaching these filters.

Study results will appear in an upcoming issue of Free Radical Biology & Medicine. An advance copy of the paper is available online on the journal's Website.

"Sunscreens do an excellent job protecting against sunburn when used correctly," said Hanson, who works in the laboratory of Christopher Bardeen, an assistant professor of chemistry at UCR. "This means using a sunscreen with a high sun protection factor and applying it uniformly on the skin. Our data show, however, that if coverage at the skin surface is low, the UV filters in sunscreens that have penetrated into the epidermis can potentially do more harm than good. More advanced sunscreens that ensure that the UV-filters stay on the skin surface are needed; such filters would reduce the level of UV-induced ROS. Another solution may be to mix the UV-filters with antioxidants since antioxidants have been shown to reduce UV-induced ROS levels in the skin."

In their research, Hanson and colleagues used epidermal model tissue and applied sunscreen to the surface to test the effect of sunscreen penetration on ROS levels in the deep epidermis. A two-photon fluorescence microscope allowed them to visualize ROS generation occurring below the skin surface. The ROS activity was detected using a probe molecule whose fluorescent properties change upon exposure to ROS. On comparing images taken before and after the skin was exposed to UV radiation, they found that ROS generation in the skin increased after sunscreen penetration.

About 95 percent of the visible signs of aging are associated with UV exposure. About 90 percent of a person's total life-time UV exposure is obtained before the person is 18 years of age. Only a few UV-filters are available that block "UV-A," the wavelengths that penetrate more deeply into the skin, all the way into the dermis where collagen exists.

"For now, the best advice is to use sunscreens and re-apply them often – the Skin Cancer Foundation recommends every two hours, and especially after sweating or swimming, which can wash away sunscreen – to reduce the amount of UV radiation from getting through to filters that have penetrated the skin," Bardeen said. "This, in turn, would reduce ROS generation."

Next, the researchers plan to investigate the effect of smog on ROS generation in the skin.

Iqbal Pittalwala | EurekAlert!
Further information:
http://www.ucr.edu

Further reports about: ROS Radiation UV radiation ultraviolet

More articles from Life Sciences:

nachricht Designer cells: artificial enzyme can activate a gene switch
22.05.2018 | Universität Basel

nachricht Flow of cerebrospinal fluid regulates neural stem cell division
22.05.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Turning entanglement upside down

23.05.2018 | Physics and Astronomy

Designer cells: artificial enzyme can activate a gene switch

22.05.2018 | Life Sciences

PR of MCC: Carbon removal from atmosphere unavoidable for 1.5 degree target

22.05.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>