New pill may help turn on anti-aging defenses

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Pill may help turn on anti-aging defenses

Medication may fight multiple diseases at once, researchers say

Reuters

Updated: 10:50 a.m. PT Sept 20, 2007

WASHINGTON - Researchers said on Thursday they had found more ways to

activate the body's own anti-aging defenses — perhaps with a pill that

could fight multiple diseases at once.

Their study, published in the journal Cell, helps explain why animals

fed very low-calorie diets live longer, but it also offers new ways to

try to replicate the effects of these diets using a pill instead of

hunger, the researchers said.

" What we are talking about is potentially having one pill that

prevents and even cures many diseases at once, " said Sinclair, a

pathologist at Harvard Medical School who helped lead the research.

Sinclair helped found a company that is working on drugs based on this

research, Sirtris Pharmaceuticals.

The key is a family of enzymes called sirtuins. They are controlled by

genes called SIRT1, SIRT2 and so on.

Last year, researchers showed that stimulating SIRT1 can help yeast

cells live longer.

Sinclair, working with colleagues at his company, at Cornell

University in New York and the U.S. National Institutes of Health,

identified the actions of two more sirtuin genes called SIRT3 and SIRT4.

They found the enzymes controlled by these genes help preserve the

mitochondria — little organs inside of cells that provide their energy.

" These two genes, SIRT3 and SIRT4, they make proteins that go into

mitochondria. ... These are little energy packs inside our cells that

are very important for staying healthy and youthful and, as we age, we

lose them and they get less efficient, " Sinclair said in a videotaped

statement.

" They are also very important for keeping the cells healthy and alive

when they undergo stress and DNA damage, as we undergo every day

during the aging process. "

Sinclair and colleagues have found in other studies that even if the

rest of a cell is destroyed — the nucleus and other parts — it can

still function if the mitochondria are alive.

His team found that fasting raises levels of another protein called

NAD. This, in turn, activates SIRT3 and SIRT4 in the mitochondria of

the cell and these help keep the mitochondria youthful.

" We've reason to believe now that these two genes may be potential

drug targets for diseases associated with aging, " Sinclair said.

" Theoretically, we can envision a small molecule (pill) that can

increase levels of NAD, or SIRT3 and SIRT4 directly, in the

mitochondria. Such a molecule could be used for many age-related

diseases, " he added.

" Diseases like heart disease, cancer, osteoporosis — even things like

cataracts. What we are aiming to do is to find the body's natural

processes that can slow down aging and treat these diseases. "

Sirtris is already working on such drugs. It has an experimental pill

called SRT501, which it is testing in Phase 2a trials in patients with

type-2 diabetes.

" These exciting new data further validate sirtuins as attractive

targets for drug development to treat diseases of aging, " Dr.

Christoph Westphal, chief executive officer of Sirtris, said in a

statement.

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URL: http://www.msnbc.msn.com/id/20890453/