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Posts Tagged ‘Aging’

Can Easter Island Compound Extend Life?

Posted by jase on July 12, 2009

The giant monoliths of Easter Island are worn, but they have endured for centuries. New research suggests that a compound first discovered in the soil of the South Pacific island might help us stand the test of time, too.

Wednesday, July 8, in the journal Nature, The University of Texas Health Science Center at San Antonio and two collaborating centers reported that the Easter Island compound – called “rapamycin” after the island’s Polynesian name, Rapa Nui – extended the expected lifespan of middle-aged mice by 28 percent to 38 percent. In human terms, this would be greater than the predicted increase in extra years of life if cancer and heart disease were both cured and prevented.

The rapamycin was given to the mice at an age equivalent to 60 years old in humans.

The studies are part of the National Institute on Aging (NIA) Interventions Testing Program, which seeks compounds that might help people remain active and disease-free throughout their lives. The other two centers involved are the University of Michigan at Ann Arbor and Jackson Laboratory in Bar Harbor, Maine.

The Texas study was led by scientists at two institutes at the UT Health Science Center: the Institute of Biotechnology (IBT) and the Barshop Institute for Longevity and Aging Studies.

“I’ve been in aging research for 35 years and there have been many so-called ‘anti-aging’ interventions over those years that were never successful,” said Arlan G. Richardson, Ph.D., director of the Barshop Institute. “I never thought we would find an anti-aging pill for people in my lifetime; however, rapamycin shows a great deal of promise to do just that.”

Discovered in the 1970s, rapamycin was first noted for its anti-fungal properties and later was used to prevent organ rejection in transplant patients. It also is used in stents, which are implanted in patients during angioplasty to keep coronary arteries open. It is in clinical trials for the treatment of cancer.

The new aging experiments found that adding rapamycin to the diet of older mice increased their lifespan. The results were the same in Texas, Michigan and Maine.

“We believe this is the first convincing evidence that the aging process can be slowed and lifespan can be extended by a drug therapy starting at an advanced age,” said Randy Strong, Ph.D., who directs the NIA-funded Aging Interventions Testing Center in San Antonio. He is a professor of pharmacology at the UT Health Science Center and a senior research career scientist with the South Texas Veterans Health Care System.

The findings have “interesting implications for our understanding of the aging process,” said Z. Dave Sharp, Ph.D., director of the Institute of Biotechnology and professor and chairman of the Health Science Center’s Department of Molecular Medicine.

“In addition,” Dr. Sharp said, “the findings have immediate implications for preventive medicine and human health, in that rapamycin is already in clinical usage.”

Source: PhysOrg.com

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Posted in Aging, Biology, Life Expectancy, Medical, Science | Tagged: , , , , , , , , , , , | Leave a Comment »

Coffee May Reverse Alzheimer’s

Posted by jase on July 5, 2009

Drinking five cups of coffee a day could reverse memory problems seen in Alzheimer’s disease, US scientists say.

The Florida research, carried out on mice, also suggested caffeine hampered the production of the protein plaques which are the hallmark of the disease.

Previous research has also suggested a protective effect from caffeine.

But British experts said the Journal of Alzheimer’s disease study did not mean that dementia patients should start using caffeine supplements.

The 55 mice used in the University of Florida study had been bred to develop symptoms of Alzheimer’s disease.

First the researchers used behavioural tests to confirm the mice were exhibiting signs of memory impairment when they were aged 18 to 19 months, the equivalent to humans being about 70.

Then they gave half the mice caffeine in their drinking water. The rest were given plain water.

The mice were given the equivalent of five 8 oz (227 grams) cups of coffee a day – about 500 milligrams of caffeine.

The researchers say this is the same as is found in two cups of “specialty” coffees such as lattes or cappuccinos from coffee shops, 14 cups of tea, or 20 soft drinks.

When the mice were tested again after two months, those who were given the caffeine performed much better on tests measuring their memory and thinking skills and performed as well as mice of the same age without dementia.

Those drinking plain water continued to do poorly on the tests.

In addition, the brains of the mice given caffeine showed nearly a 50% reduction in levels of the beta amyloid protein, which forms destructive clumps in the brains of dementia patients.

Further tests suggested caffeine affects the production of both the enzymes needed to produce beta amyloid.

The researchers also suggest that caffeine suppresses inflammatory changes in the brain that lead to an overabundance of the protein.

Earlier research by the same team had shown younger mice, who had also been bred to develop Alzheimer’s but who were given caffeine in their early adulthood, were protected against the onset of memory problems.

‘Safe drug’

Dr Gary Arendash, who led the latest study, told the BBC: “The results are particularly exciting in that a reversal of pre-existing memory impairment is more difficult to achieve.

“They provide evidence that caffeine could be a viable ‘treatment’ for established Alzheimer’s disease and not simply a protective strategy.

“That’s important because caffeine is a safe drug for most people, it easily enters the brain, and it appears to directly affect the disease process.”

The team now hope to begin human trials of caffeine to see if the mouse findings are replicated in people.

They do not know if a lower amount of caffeine would be as effective, but said most people could safely consume the 500 milligrams per day.

However they said people with high blood pressure, and pregnant women, should limit their daily caffeine intake.

Rebecca Wood, chief executive of the Alzheimer’s Research Trust, said: “In this study on mice with symptoms of Alzheimer’s, researchers found that caffeine boosted their memory. We need to do more research to find out whether this effect will be seen in people.

“It is too early to say whether drinking coffee or taking caffeine supplements will help people with Alzheimer’s.

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Gray Hair Caused by DNA Damage

Posted by jase on June 19, 2009

Christine Dell’Amore over at National Geographic News posted the following fascinating finding:

Work or personal stress may make you want to pull your hair out, but it’s cellular stress that actually turns it gray, a new study has found.

That’s because DNA is “under constant attack” by damaging agents, such as chemicals, ultraviolet light, and ionizing radiation, according to study lead author Emi Nishimura of Tokyo Medical and Dental University.

A single mammal cell can encounter up to 100,000 events a day that damage DNA, Nishimura added in a statement.

The stem cells within hair follicles responsible for color are the most impacted by this irreparable DNA weathering.

Stem cells are cells in the body that can reproduce indefinitely and that have the potential to “mature” into other, more specialized cells. The stem cells in hair follicles mature into melanocytes, or cells that produce the pigment melanin.

In younger people, the hair’s stem cells maintain a balance between those that reproduce and those that turn into pigment cells, so that pigment is constantly being added to growing hair.

But as a person ages, too many of the stem cells mature until the pool of pigment cells gets totally drained and hair grows gray.

Scientists have been unsure what exactly spurs the stem cells to change. According to Nishimura, the answer may be accumulated DNA damage.

Forcing the cells to mature may be the body’s “more sophisticated way” of purging the damaged stem cells without killing them off, she said.

Unavoidable Damage

The study focused on graying because it is a typical sign of aging in mammals, the authors wrote.

The researchers put laboratory mice through whole-body x-rays and chemical injections.

When the team examined the mice’s hair follicles, they found that the stem cells showed permanent damage. These mice then regrew hair with no pigment.

The research supports the idea that instability in genes may be a major factor in aging, the authors say. It also lends credence to the theory that damage to stem cells may be the main driver of aging.

The DNA damage observed in the study is mainly “unavoidable,” the authors write.

Linzhao Cheng, a member of the Johns Hopkins Institute of Cell Engineering, agreed that it’s tough to avoid stem cell damage—especially for people who spend a lot of time outdoors, which exposes them to ultraviolet radiation from the sun.

However, the study helps scientists understand graying, Cheng said by email, which may lead to new chemicals that can prevent the hair’s stem cells from switching roles.

“We may soon have anti-graying creams for aging populations,” he said.

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