A team of researchers from the Max Planck Institute for Biology of Ageing has revealed that brief exposure to the macrolide drug rapamycin could have similar effects on lifespan as lifelong use.
In their study published in the journal Nature Aging, the scientists found that exposing laboratory animals to the drug in early adulthood had the same anti-aging effects as when they are given their lifetime.
“These brief drug treatments in early adulthood produced just as strong protection as continuous treatment started at the same time,” said paper co-author Dr. Thomas Leech.
This finding could open the door for the use of rapamycin in combating aging effects and extending lifespan in humans.
Drug repurposing to fight aging
According to research, lifestyle changes can make some difference in helping people to live longer and enjoy good health. But evidence has also shown that these changes alone are not enough to prevent health issues in old age.
Scientists have, therefore, also been looking in the direction of repurposing drugs for other conditions to help fight age-related decline. The most promising drug identified so far for this purpose is rapamycin.
This drug is typically used to guard against organ transplant rejection and also in cancer therapy.
The use of rapamycin comes with risks, however. Awful side effects can result from low clinical doses. Yet, a drug that would be used to fight aging effects and increase lifespan should not have these unwanted effects.
To derive maximum positive effects, this immunosuppressive agent needs to be taken as a lifelong treatment.
Dr. Paula Juricic and her colleagues sought to find out in this study what alternatives exist to using rapamycin lifelong to combat age-related decline.
Brief exposure is beneficial
The researchers tested the drug for different short lengths of time in both fruit flies and mice. Two-week therapy in young adult flies was observed to protect against age-related failure in their intestines and prolong their lives. An equivalent short-time treatment window (three months) in mice produced similar intestinal health benefits during middle age.
“We also found that the rapamycin treatment had the strongest and best effects when given in early life as compared to middle age,” explained Leech. “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.”
The researchers noted that their results make the use of the drug for anti-aging purposes potentially more practical in humans. They suggest some benefits may be obtained without going on lifelong treatment, with its unpleasant side effects.
While acknowledging that their research has opened new doors, senior study author Professor Linda Partridge noted that it has also “raised many new questions.” It is critical to find out whether geroprotection similar to that observed in mice could be achieved with later-life treatment in humans, she said. This is bearing in mind that the treatment must be brief.
Researchers could also need to find out whether intermittent dosing in humans would produce similar effects.