A drug derived from bacteria in the soil on Easter Island can substantially extend the life span of mice, according to a study published online today in Nature. The drug, called rapamycin, is the first pharmacological agent shown to enhance longevity in a mammal, and it works when administered beginning late in life. Prior to this research, the only ways to increase rodents’ life span were via genetic engineering or caloric restriction–a nutritionally complete but very low-calorie diet.
Rapamycin is an antifungal compound already approved by the FDA as an immunosuppressive therapy to help prevent organ rejection in transplant patients. It is currently being tested in clinical trials for potential anticancer effects.
The drug had previously been shown to extend life span in invertebrates. "[This study is] exciting because it shows that it’s feasible to do this in a mammal," says David Sinclair, codirector of the Paul F. Glenn Laboratories for the Biological Mechanisms of Aging at Harvard Medical School, who was not involved in the study. "Maybe 20 years from now we’ll look back at this study as a landmark that pointed the way to medicines of the future."
In the new study, researchers found that rapamycin given to mice as a food supplement starting at 20 months of age–the equivalent of 60 years in humans–extended average life span by 9 percent in males and 13 percent in females. "It’s particularly exciting because it works so late in life to extend life span," says Sinclair. "The fact that you can give a drug after 20 months of age in a mouse and still see a life-span extension is striking."