A drug that extends life?10th July 2009
New research from the United States has found that a drug discovered in the soil of a South Pacific island may fight ageing.
Rapamycin, commonly used to suppress the immune system so that organ transplant patients do not reject donated tissue, was found by a team of researchers in three US states to extend the lifespan of elderly mice by up to 38%.
The report, published in the journal Nature, said the findings could pave the way for drugs to slow the ageing process in people.
But experts warned that rapamycin, which was discovered in the soil of Easter Island nearly four decades agao, suppressed the immune system, making it risky to try as a life extending drug.
Rapamycin, currently also being tested as a possible treatment for cancer, is also commonly used in stents implanted into patients' arteries to keep them open.
The research team, based in Texas, Michigan and Maine, administered rapamycin to mice aged the equivalent of 60 in humans.
As closely as possible, the mice were bred to mimic the range of susceptibility to disease and genetic diversity that is commonly found in humans.
The animals fed rapamycin lived between 28% and 38% longer than the control group which was not given the drug.
In human terms, researchers estimated that this might translate into an even greater extension of life for humans, if cancer and heart disease were absence.
Ageing researcher Arlan Richardson of the Barshop Institute, said he had never expected to find an anti-ageing pill.
But he said rapamycin showed a great deal of promise to extend life.
The team said the tests provided the first convincing evidence that lifespan could be extended by drug therapies starting at an advanced age.
The University of Texas Health Science Center's Randy Strong said he believed it was possible to slow ageing with medication.
Restriction of calorie intake has a similar effect to rapamycin in extending life, and the drug appears to work in a similar way, by targeting the mTOR protein, which is involved in metabolism and in response to stress.
Rapamycin had to be reformulated for use in mice, so it was metabolised in the intestines of the mice.
Feeding only began when the animals were 20 months old, because of the delay caused by the reformulation procedure.
They had expected the drug to make little impact on lifespan because it was being given at such an advanced age.
The team said the potential reduction in healthcare costs from life-extending drugs was enormous.
Ageing expert Lynne Cox at Oxford University said the findings were interesting and exciting. But she cautioned against experimenting with rapamycin, as it suppressed the immune system in humans.
The laboratory mice were protected from infection for the duration of the experiment, which was simply not possible for people living in the real world, she said.
Cox suggested expansion of healthy years lived might be a better goal than prolonging life in numerical terms.
Share this page
There are no comments for this article, be the first to comment!
Post your comment
Only registered users can comment. Fill in your e-mail address for quick registration.
Title: A drug that extends life?
Author: Luisetta Mudie
Article Id: 12086
Date Added: 10th Jul 2009