rapamycin

Rapamycin
A new medicine is appair for cencere which is helping for also for transplant patient
rapamycin

A new star has appeared in the field of drugs that delay aging in laboratory animals, and are therefore candidates for doing the same in people.

The drug is an antibiotic, rapamycin, already in use for suppressing the immune system in transplant patients and for treating certain cancers.

Rapamycin treatment had the remarkable effect of extending life even though it was not started in the right dose until the mice had lived 600 days — equivalent to a person at age 60. Most interventions that prolong life in mice, including a very low-calorie diet, need to be started early in life to show any effect.

Experts warn that this should not be tried at home. No one knows yet if rapamycin slows aging in people or at what dose it might be effective. And any drug that suppresses the immune system is not to be trifled with.

The finding was reported online Wednesday in Nature by researchers at three institutions working in parallel. The teams were led by David E. Harrison of the Jackson Laboratory, a mouse-breeding powerhouse in Bar Harbor, Me.; Richard E. Miller of the University of Michigan; and Randy Strong of the University of Texas Health Science Center.

The researchers do not know how rapamycin secures its anti-aging effect. It could be just halting tumors rather than delaying the aging process in general.

The three teams were sponsored by the National Institute of Aging as part of a program to test possible anti-aging drugs much more rigorously.

“One of the nasty secrets of the field is that most mouse longevity experiments are done only once in one lab on one genetic background,” said Steven Austad, an expert on aging at the University of Texas Health Science Center, who was not involved in the research.

The National Institute of Aging program includes a test of two doses of resveratrol, the ingredient of red wine that is thought to mimic the effects of caloric restriction on longevity. The results have not been published, but Christoph Westphal, chief executive of Sirtris, a company exploring the health effects of resveratrol and similar chemicals, said the tests “are seeing quite modest effects of resveratrol.”

The effectiveness of rapamycin in extending the life of elderly mice was discovered by accident. The researchers found that the mice fed rapamycin were not getting the proper dose in their bloodstream. They reformulated the drug in the form of capsules that fed slow doses to the intestine, but by that time the mice were elderly. Nonetheless, life span increased by 14 percent in the females and 9 percent in the males.

“It’s no longer irresponsible to say that following these up could lead to medicines that increase human life span by 10, 20 or 30 percent,” Dr. Miller said.

It will be at least 10 years before matters are sorted out, he said, but, as of right now, “I don’t think there’s any evidence for people that there’s any drug that can slow aging down.”