University of Florida Health researchers found that Rapamycin, a pharmaceutical used to coat coronary stents and prevent transplant rejection, can reduce obesity and preserve lean body mass when given to older rats.
Although the current findings are limited to rats, rapamycin has potential as a treatment for age-related obesity since it is already being used to treat other conditions in people, researchers said.
"We need to be able to intervene with treatments for older adults. They're going to have health care issues, and not everyone can get up and exercise. So if you can give them a jump-start or combine rapamycin with other therapies, you could have better health outcomes," said Christy S Carter, an assistant professor in the Department of Ageing and Geriatric Research in the University of Florida College of Medicine.
Using 25-month-old rats, which are about equivalent to 65-year-old people, researchers found that body weight dropped by approximately 13 per cent after the rats were treated with rapamycin.
More From This Section
The drug targets the production of leptin, a hormone that affects hunger and metabolism. The researchers believe that normalising the typical age-related spike in leptin results in the reduction of eating.
Rapamycin's ability to stabilise the rats' leptin level made them lighter, researchers found.
In another study, researchers found that small, intermittent amounts of rapamycin produced the desired slimming effect in both young and old rats.
The study determined that the drug works by inhibiting a signalling mechanism known as mTORC1, a protein complex that is an energy and nutrient sensor.
This triggers a response in the brain that curbs eating, effectively reducing age-related fat until the older animals resemble much younger ones.
While rapamycin works best in older, obese rats, researchers were encouraged that it also had an effect on certain younger animals.
"One point that is common is that it seems to work better in animals, old or young, that have more fat," Scarpace said.