Sunscreen that protects DNA from UV rays

Sunscreen that protects DNA from UV rays

The experiment at the Department of Energy’s SLAC National Accelerator Laboratory focused on thymine, one of four DNA building blocks.

Ever heard of a molecular sunscreen? It is a defence mechanism that the molecular building blocks that make up DNA mount to prevent the damage by ultraviolet rays, reveals new research.

The DNA forming molecules absorb ultraviolet light so strongly that sunlight should deactivate them. But a “relaxation response” protects these molecules and the genetic information they encode from UV damage, the researchers said.

The experiment at the Department of Energy’s SLAC National Accelerator Laboratory focused on thymine, one of four DNA building blocks.

Researchers hit thymine with a short pulse of ultraviolet light and used a powerful X-ray laser to watch the molecule’s response.

A single chemical bond stretched and snapped back into place within 200 quadrillionths of a second, setting off a wave of vibrations that harmlessly dissipated the destructive UV energy.

Researchers had noticed years ago that thymine seemed resistant to damage from UV rays in sunlight, which cause sunburn and skin cancer.

Theorists proposed that thymine got rid of the UV energy by quickly shifting shape.

But they differed on the details, and previous experiments could not resolve what was happening.

“As soon as the thymine swallows the light, the energy is funnelled as quickly as possible into heat, rather than into making or breaking chemical bonds,” said lead researcher Markus Guehr from Stanford University in the US.

“It is like a system of balls connected by springs; when you elongate that one bond between two atoms and let it loose, the whole molecule starts to tremble,” he explained.

The findings appeared in the journal Nature Communications.

Source: Khaleej times

9 Ways to Prevent Skin Cancer


1. Reduce Sun Exposure

Especially between 11 am and 4 pm, when the sun’s UV rays are the strongest or when UV index is 3 or more.

2. Shade your Skin

  • Seek shade under trees, or create your own shade with a hat, shirt, or umbrella.
  • Wear clothing to cover your arms and legs. Make sure the fabric has a tight weave. Fabric that is wet or has a loose weave will allow more light to penetrate through to the skin.
  • Wear a wide brimmed hat and sunglasses with UV protection.

3. Beware of clouds

Up to 80% of the sun’s rays can penetrate light clouds, mist and fog. You can still get a sunburn on a cloudy day.

4. Remember about Reflection

Water, sand, snow and concrete can reflect up to 80% of the sun’s damaging rays.

5. Slop on the Sunscreen

Use sunscreens with an SPF of 15 or more that contain both UVA and UVB protection.

Apply sunscreen 15-30 minutes before going outside, and reapply every 2 hours (more often when working, playing, or swimming).

6. Avoid tanning salons and sunlamps

These lights emit mostly UVA radiation – up to 2 – 5 times as much as natural sunlight. UVA radiation causes sunburn, premature aging of the skin and skin cancer.

The UVB radiation from tanning lights is the main cause of sunburn and skin cancer and also contributes to premature skin aging.

For more information see youth tanning (link to being modified by the school team)

7. Protect Children

The most harmful effects of sun exposure occur during early childhood. Keep babies under 1 year out of direct sunlight. Once infants turn 6 months of age, begin using a sunscreen for added protection. It’s important to protect your child’s eyes by using plastic lens sunglasses that protect against UVA and UVB rays.

  • Children should have arms and legs covered when out in the sun.
  • Instead of wearing baseball caps, they should wear hats with a wide brim, which provides more sun protection.
  • When children are playing in the water, make sure to use waterproof sunscreen.

8. Protect your Eyes

Radiation from the sun can damage cells in the structures of your eyes. UV radiation from the sun may increase the risk of developing cataracts later in life. UV radiation can also contribute to the development of skin cancer on the eyelid or on the surface of the eye. This damage can be prevented by protecting your eyes with sunglasses that protect against 100% UVA and UVB rays. Wearing a hat with a wide brim all the way around when out in the sun. Legionnaire style caps (caps with a flap a back flap) are also recommended to help protect the neck, ears and face.

9. Spot Check Your Moles

  • Examine your moles and freckles every month to check for any changes. See your health care provider immediately if you notice:
  • a mole or discolouration that appears suddenly or begins to change
  • a sore that does not heal
  • areas of skin that are red and bumpy, bleed or are itchy

Source: health unit

Heavy drinking may ‘increase skin cancer risk by more than half

Heavy drinking can increase the risk of developing the deadliest form of skin cancer by more than half, researchers have warned.

Downing three or four drinks a day does more than make us careless about getting sunburnt, it causes biological changes which make the body more sensitive to sun, they say.

Even one drink a day can raise the chance of getting melanoma by 20 per cent; for heavier drinkers the risk is raised by 55 per cent.

Researcher Dr Eva Negri said the mix of UV rays and alcohol damaged the body’s immune responses.

She added: ‘This can lead to far greater cellular damage and subsequently cause skin cancers to form.

‘This study aimed to quantify the extent to which the melanoma risk is increased with alcohol intake and we hope that, armed with this knowledge, people can better protect themselves.’

The warnings, published in the British Journal of Dermatology, are based on a review of 16 other studies and 6,251 cases of melanoma.

The researchers admit they do not know exactly how drinking increases the cancer risk. But they found alcohol is turned into a chemical called acetaldehyde soon after it is consumed and that makes the skin more sensitive to sunlight.

Leading dermatologist Prof Chris Bunker said: ‘Brits haven’t always been known for their moderation when it comes to either alcohol or the sun but this research provides people with further information to make informed choices about their health.’

Source: Metro news