Photo by: Sell et al, courtesy of Drexel University
Rapamycin, a medication typically used to prevent rejection of transplanted organs, appears to slow aging in human skin when used topically.
These findings come from a paper published online in Geroscience (Nov. 25, 2019).
Previous research has looked at using rapamycin to slow aging in animal models, but this is the first to look at aging in human tissue. In this new study, 13 individuals aged >40 applied rapamycin cream every one to two days to one hand, and a placebo to the other hand, for eight months. Follow-up observations were done at months two, four, six, and eight, including blood tests and a biopsy at the six- or eight-month visit.
“As researchers continue to seek out the elusive ‘fountain of youth’ and ways to live longer, we’re seeing growing potential for use of this drug,” said senior author Christian Sell, PhD, in a press release from Drexel University. Dr. Sell is an associate professor of biochemistry and molecular biology at the Drexel University College of Medicine in Philadelphia. “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.”
After eight months, the majority of the hands treated with rapamycin showed increases in collagen protein, and statistically significant lower levels of p16 protein, a key marker of skin cell aging. Lower levels of p16 in skin correlates with fewer senescent cells, which are associated with skin wrinkles, according to the release. 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.
Rapamycin is involved in regulating the release of the p16 protein, which is a stress response that human cells undergo when damaged, such as when developing cancer-promoting mutations, according to the release. When cells have a mutation that would have otherwise created a tumour, this response helps prevent the tumour by slowing the cell cycle process. Instead of creating a tumour, it contributes to the aging process.
“When cells age, they become detrimental and create inflammation,” said Dr. Sell. “That’s part of aging. These cells that have undergone stress are now pumping out inflammatory markers.”