Nov. 26 (UPI) -- The "Fountain of Youth" may not be flowing with water, but instead a drug designed for an entirely different purpose, research suggests.
A study published Tuesday in the journal Geroscience has found that rapamycin, a drug approved by the U.S. Food and Drug Administration for the prevention of organ rejection following transplant surgery, may also slow aging in human skin.
When applied to human skin, the drug appears to help reduce wrinkles and sagging and improve skin tone, researchers report after a small study.
"As researchers continue to seek out... ways to live longer, we're seeing growing potential for use of this drug," said senior author Christian Sell, an associate professor of Biochemistry and Molecular Biology at Drexel University College of Medicine in Philadelphia, in a statement. "So, we said, let's try skin. It's a complex organism with immune, nerve cells, stem cells -- you can learn a lot about the biology of a drug and the aging process by looking at skin."
The study in humans follows on the heels of basic science studies, which have used the drug to slow aging in mice, flies and worms. However, the Geroscience study is the first to show an effect on aging in human tissue, specifically skin -- in which signs of aging were reduced.
In the Drexel-led study, 13 participants over age 40 applied rapamycin cream every one to two days to one hand and a placebo to the other hand for eight months. The researchers checked on subjects after two, four, six and eight months, including conducting a blood test and a biopsy at the six- or eight-month mark.
After eight months, the majority of the rapamycin hands showed increases in collagen protein, and statistically significant lower levels of p16 protein, a key marker of skin cell aging. Skin that has lower levels of p16 has fewer senescent cells, which are associated with skin wrinkles.
Beyond cosmetic effects, higher levels of p16 can lead to dermal atrophy, a common condition in seniors, which is associated with fragile skin that tears easily, slow healing after cuts and increased risk of infection or complications after an injury.
According to the authors, rapamycin achieves its effects by blocking the appropriately named "target of rapamycin," or TOR, a protein that acts as a mediator in metabolism, growth and aging of human cells.
"When cells age, they become detrimental and create inflammation," said Sell. "That's part of aging. These cells that have undergone stress are now pumping out inflammatory markers."
In addition to its use in preventing organ rejection, rapamycin is currently prescribed in higher doses to treat a rare lung disease called lymphangioleiomyomatosis, and as an anti-cancer drug. The drug was first discovered in the 1970s in bacteria found in the soil of Easter Island.
The researchers note that, as this is early research, many more questions remain about how to harness the drug. Future studies will look at how to apply the drug in clinical settings, and find applications in other diseases.
There are two pending patents on this technology, both of which have been licensed to Boinca Therapeutics LLC., of which Sell is a shareholder.