Imagine being able to take a medication that keeps you healthy and delays the effects of aging. Researchers are looking for a medication that has these outcomes. Rapamycin, known for its beneficial benefits on life and health span in experimental tests with laboratory animals, is currently the most promising anti-aging medication.
The medicine is frequently administered throughout the rest of one’s life in order to get its full benefits. However, adverse side effects can still happen at the low levels used to prevent age-related decline, thus it is always preferable to take the lowest effective dose.
It has now been demonstrated in laboratory animals by a study team at the Max Planck Institute for Biology of Ageing in Cologne, Germany, that brief exposure to rapamycin has the same beneficial benefits as a lifetime of treatment, bringing up new possibilities for possible human use.
The focus of scientific research is shifting more and more toward combating the harmful impacts of aging. The health of older individuals can be improved by changing their lifestyles, but this is insufficient to stop the evils of aging on its own.
Repurposing existing medications for “geroprotection” gives doctors another tool to fend against age-related deterioration. Rapamycin, a cell growth inhibitor and immunosuppressant typically used in cancer treatment and after organ transplants, is now the most promising anti-aging medication.
“At the doses used clinically, rapamycin can have undesirable side effects, but for the use of the drug in the prevention of age-related decline, these need to be absent or minimal. Therefore, we wanted to find out when and how long we need to give rapamycin in order to achieve the same effects as lifelong treatment,” explains Dr. Paula Juricic, the leading investigator of the study in the department of Prof. Linda Partridge, director at the Max Planck Institute for Biology of Ageing.
These brief drug treatments in early adulthood produced just as strong protection as continuous treatment started at the same time. We also found that the rapamycin treatment had the strongest and best effects when given in early life as compared to middle age. When the flies were treated with rapamycin in late life, on the other hand, it had no effects at all. So, the rapamycin memory is activated primarily in early adulthood.
Dr. Thomas Leech
Only brief exposure
A brief window of 2 weeks of rapamycin treatment in young, adult flies was discovered to extend their lifespan and protect them from age-related disease in the intestine by testing several temporal windows of short-term drug administration in fruit flies.
In young, adult mice, a comparable brief time window of 3 months of therapy beginning at 3 months of life showed similar favorable impacts on the health of the intestine when they were middle-aged.
“These brief drug treatments in early adulthood produced just as strong protection as continuous treatment started at the same time. We also found that the rapamycin treatment had the strongest and best effects when given in early life as compared to middle age. When the flies were treated with rapamycin in late life, on the other hand, it had no effects at all. So, the rapamycin memory is activated primarily in early adulthood,” explains Dr. Thomas Leech, co-author of the paper.
One step closer to applications
“We have found a way to circumvent the need for chronic, long-term rapamycin intake, so it could be more practical to apply in humans,” says Dr. Yu-Xuan Lu, also co-author of the paper.
Prof. Linda Partridge, the senior author of the study, comments: “It will be important to discover whether it is possible to achieve the geroprotective effects of rapamycin in mice and in humans with treatment starting later in life since ideally the period of treatment should be minimized. It may be possible also to use intermittent dosing. This study has opened new doors, but also raised many new questions.”
