Excessive exposure to sunlight is the leading cause of skin deterioration, causing it to age prematurely. We need some exposure, however, in order to synthesize vitamin D – plus who wants to stay in the shade all the time? Using a good sunscreen definitely helps, although scientists from the University of British Columbia are taking things a step farther – they're developing a drug that could ultimately prevent the sunlight-related aging of skin.

The discovery was made unintentionally.

A team led by UBC's Prof. David Granville started out investigating the role that an enzyme known as granzyme B may play in atherosclerosis and heart attacks. Granzyme B occurs naturally in the body, although excessive levels of it have been linked to various autoimmune diseases and the destruction of collagen.

In this case, the scientists were interested in seeing if mice lacking the enzyme were more resistant to the hardening and narrowing of blood vessels. Along the way, however, they noticed that those mice had much smoother, more youthful skin than animals with normal amounts of granzyme B.

The researchers then proceeded to put both types of mice in a sunlight-simulating carousel that exposed them to ultraviolet light for three to four minutes, three times a week – enough to cause redness, but not to cause serious burns. After 20 weeks of repeated exposure, the skin of granzyme B-less mice was in much better shape, and retained significantly more collagen than that of the other group.

Granville is now developing a topically-applied drug to inhibit granzyme B activity, through UBC spin-off company viDA Therapeutics. Plans call for the medication to be tested within two years on test subjects with discoid lupus erythematosus, an autoimmune disease that causes facial scarring and is made worse by exposure to sunlight.

If it proves effective with that group, it may ultimately find use in the form of lotion that anyone can apply, to keep the sun from aging their skin. A non-topical version could also find use treating conditions such as aneurysms and chronic obstructive pulmonary disease, which are caused by the breakdown of collagen in blood vessels and lung passages.

A paper on the research was recently published in the journal Aging Cell.

Source: UBC