Natural enzyme helps mice live longer in study

Roman Bystrianyk · medicine forum Guru Joined: 02 May 2005 Posts: 454

http://www.healthsentinel.com/news.php?event=news_print_list_item&id=796

"Natural enzyme helps mice live longer in study", Reuters, May 5, 2005,
Link:
http://www.reuters.com/newsArticle.jhtml;jsessionid=SRCNB13QILKDMCRBAEKSFFA?type=healthNews&storyID=8403539

Mice genetically engineered to produce a human antioxidant enzyme lived
longer than normal mice, which U.S. scientists on Thursday cited as
evidence that antioxidants can counteract the effects of aging and
disease.

Chemicals known as free radicals damage cells by generating a reaction
called oxidation -- the same process that causes metal to rust.
Antioxidants interfere with this chemical reaction.

Writing in the journal Science, Dr. Peter Rabinovitch and colleagues at
the University of Washington School of Medicine said they helped show
free radicals can damage cells and DNA.

The researchers used genetically engineered mice that made extra
amounts of catalase, an antioxidant enzyme that helps break down
hydrogen peroxide into water and oxygen.

Hydrogen peroxide is produced during metabolism and it can be a
precursor of free radicals.

The mice were precisely designed to produce extra catalase in certain
areas of the body -- the cells' cytoplasm; the nucleus where DNA is
stored; and the mitochondria, the cell's power plant and also a place
where some DNA is found.

The mice that made more catalase in the mitochondria lived about 20
percent longer -- about five months. The mice with more catalase levels
in the nucleus and cytoplasm lived only a little longer than normal
mice.

The mice with catalase in the mitochondria also had healthier heart
muscle tissue, indicating the catalase helped protect from age-related
heart problems seen in normal mice.

"This study is very supportive of the free-radical theory of aging,"
Rabinovitch said in a statement. "It shows the significance of free
radicals, and of reactive oxygen species in particular, in the aging
process."

It also supports the idea that the mitochondria produce many of these
damaging free radicals as part of everyday metabolism.

The findings could be used as a basis for drugs or other treatments
that protect the body from free radicals and perhaps some age-related
conditions, Rabinovitch said.

"People used to only focus on specific age-related diseases, because it
was believed that the aging process itself could not be affected,"
Rabinovitch said.

"What we're realizing now is that by intervening in the underlying
aging process, we may be able to produce very significant increases in
'healthspan,' or healthy lifespan."

Google